WorldWideScience

Sample records for cells promote tolerance

  1. Cytokines affecting CD4+T regulatory cells in transplant tolerance. III. Interleukin-5 (IL-5) promotes survival of alloantigen-specific CD4+ T regulatory cells.

    Science.gov (United States)

    Hall, Bruce M; Plain, Karren M; Tran, Giang T; Verma, Nirupama D; Robinson, Catherine M; Nomura, Masaru; Boyd, Rochelle; Hodgkinson, Suzanne J

    2017-08-01

    CD4 + T cells mediate antigen-specific allograft tolerance, but die in culture without activated lymphocyte derived cytokines. Supplementation of the media with cytokine rich supernatant, from ConA activated spleen cells, preserves the capacity of tolerant cells to transfer tolerance and suppress rejection. rIL-2 or rIL-4 alone are insufficient to maintain these cells, however. We observed that activation of naïve CD4 + CD25 + FOXP3 + Treg with alloantigen and the Th2 cytokine rIL-4 induces them to express interleukin-5 specific receptor alpha (IL-5Rα) suggesting that IL-5, a Th2 cytokine that is produced later in the immune response may promote tolerance mediating Treg. This study examined if recombinant IL-5(rIL-5) promoted survival of tolerant CD4 + , especially CD4 + CD25 + T cells. CD4 + T cells, from DA rats tolerant to fully allogeneic PVG heart allografts surviving over 100days without on-going immunosuppression, were cultured with PVG alloantigen and rIL-5. The ability of these cells to adoptively transfer tolerance to specific-donor allograft and suppress normal CD4 + T cell mediated rejection in adoptive DA hosts was examined. Tolerant CD4 + CD25 + T cells' response to rIL-5 and expression of IL-5Rα was also assessed. rIL-5 was sufficient to promote transplant tolerance mediating CD4 + T cells' survival in culture with specific-donor alloantigen. Tolerant CD4 + T cells cultured with rIL-5 retained the capacity to transfer alloantigen-specific tolerance and inhibited naïve CD4 + T cells' capacity to effect specific-donor graft rejection. rIL-5 promoted tolerant CD4 + CD25 + T cells' proliferation in vitro when stimulated with specific-donor but not third-party stimulator cells. Tolerant CD4 + CD25 + T cells expressed IL-5Rα. This study demonstrated that IL-5 promoted the survival of alloantigen-specific CD4 + CD25 + T cells that mediate transplant tolerance. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Recipient dendritic cells, but not B cells, are required antigen-presenting cells for peripheral alloreactive CD8+ T-cell tolerance.

    Science.gov (United States)

    Mollov, J L; Lucas, C L; Haspot, F; Gaspar, J Kurtz C; Guzman, A; Sykes, M

    2010-03-01

    Induction of mixed allogeneic chimerism is a promising approach for achieving donor-specific tolerance, thereby obviating the need for life-long immunosuppression for solid organ allograft acceptance. In mice receiving a low dose (3Gy) of total body irradiation, allogeneic bone marrow transplantation combined with anti-CD154 tolerizes peripheral CD4 and CD8 T cells, allowing achievement of mixed chimerism with specific tolerance to donor. With this approach, peripheral CD8 T-cell tolerance requires recipient MHC class II, CD4 T cells, B cells and DCs. Recipient-type B cells from chimeras that were tolerant to donor still promoted CD8 T-cell tolerance, but their role could not be replaced by donor-type B cells. Using recipients whose B cells or DCs specifically lack MHC class I and/or class II or lack CD80 and CD86, we demonstrate that dendritic cells (DCs) must express CD80/86 and either MHC class I or class II to promote CD8 tolerance. In contrast, B cells, though required, did not need to express MHC class I or class II or CD80/86 to promote CD8 tolerance. Moreover, recipient IDO and IL-10 were not required. Thus, antigen presentation by recipient DCs and not by B cells is critical for peripheral alloreactive CD8 T cell tolerance.

  3. Regulatory dendritic cells for promotion of liver transplant operational tolerance: Rationale for a clinical trial and accompanying mechanistic studies.

    Science.gov (United States)

    Thomson, Angus W; Humar, Abhinav; Lakkis, Fadi G; Metes, Diana M

    2018-05-01

    Dendritic cells (DC) are rare, bone marrow (BM)-derived innate immune cells that critically maintain self-tolerance in the healthy steady-state. Regulatory DC (DCreg) with capacity to suppress allograft rejection and promote transplant tolerance in pre-clinical models can readily be generated from BM precursors or circulating blood monocytes. These DCreg enhance allograft survival via various mechanisms, including promotion of regulatory T cells. In non-human primates receiving minimal immunosuppressive drug therapy (IS), infusion of DCreg of donor origin, one week before transplant, safely prolongs renal allograft survival and selectively attenuates anti-donor CD8 + memory T cell responses in the early post-transplant period. Based on these observations, and in view of the critical need to reduce patient dependence on non-specific IS agents that predispose to cardiometabolic side effects and renal insufficiency, we will conduct a first-in-human safety and preliminary efficacy study of donor-derived DCreg infusion to achieve early (18 months post-transplant) complete IS withdrawal in low-risk, living donor liver transplant recipients receiving standard-of-care IS (mycophenolate mofetil, tacrolimus and steroids). We will test the hypothesis that, although donor-derived DCreg are short-lived, they will induce robust donor-specific T cell hyporesponsiveness. We will examine immunological mechanisms by sequential analysis of blood and tissue samples, incorporating cutting-edge technologies. Copyright © 2017 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

  4. Transient B cell depletion or improved transgene expression by codon optimization promote tolerance to factor VIII in gene therapy.

    Directory of Open Access Journals (Sweden)

    Brandon K Sack

    Full Text Available The major complication in the treatment of hemophilia A is the development of neutralizing antibodies (inhibitors against factor VIII (FVIII. The current method for eradicating inhibitors, termed immune tolerance induction (ITI, is costly and protracted. Clinical protocols that prevent rather than treat inhibitors are not yet established. Liver-directed gene therapy hopes to achieve long-term correction of the disease while also inducing immune tolerance. We sought to investigate the use of adeno-associated viral (serotype 8 gene transfer to induce tolerance to human B domain deleted FVIII in hemophilia A mice. We administered an AAV8 vector with either human B domain deleted FVIII or a codon-optimized transgene, both under a liver-specific promoter to two strains of hemophilia A mice. Protein therapy or gene therapy was given either alone or in conjunction with anti-CD20 antibody-mediated B cell depletion. Gene therapy with a low-expressing vector resulted in sustained near-therapeutic expression. However, supplementary protein therapy revealed that gene transfer had sensitized mice to hFVIII in a high-responder strain but not in mice of a low-responding strain. This heightened response was ameliorated when gene therapy was delivered with anti-murine CD20 treatment. Transient B cell depletion prevented inhibitor formation in protein therapy, but failed to achieve a sustained hypo-responsiveness. Importantly, use of a codon-optimized hFVIII transgene resulted in sustained therapeutic expression and tolerance without a need for B cell depletion. Therefore, anti-CD20 may be beneficial in preventing vector-induced immune priming to FVIII, but higher levels of liver-restricted expression are preferred for tolerance.

  5. Thioredoxin priming prolongs lung allograft survival by promoting immune tolerance.

    Directory of Open Access Journals (Sweden)

    Hanbo Hu

    Full Text Available Tolerance to allograft antigen is the major challenge and final goal of transplant medicine. Our previous study demonstrated that thioredoxin-1 (Trx priming of donor lung significantly protected allogeneic lung graft. To determine whether Trx priming of donor lung inhibits allograft rejection, extends allograft survival and induces immune tolerance, orthotopic left lung transplantation was performed from Lewis to Sprague-Dawley rats without immunosuppression. Donor lungs were primed with Trx at 4°C for 4 hr prior to transplantation. After up to 37 days post-transplantation, allograft lung morphology, recipient T cell and humoral alloantigen-specific immune responses were examined. We found that Trx-primed lungs exhibited much reduced acute rejection and associated lung injuries resulting in loss of graft functional area at 5-37 days post-transplant in contrast to the control groups. CD4+ T cells from the recipients with Trx-primed grafts responded to the stimulation of dendritic cells (DCs of donor origin, in contrast to DCs from the third party, with significantly reduced proliferation. Consistent with above findings, we observed that CD4+Foxp3+ regulatory T cells in spleen cells from the recipients with Trx-primed grafts were significantly increased compared to controls, and CD4+ T cells from the recipients with Trx-primed grafts produced much higher levels of immunosuppressive cytokine, IL-10 when stimulated with allogeneic donor DCs. In addition, humoral immune tolerance was also induced as there was no significant increase levels of serum antibodies against donor antigens in Trx-lung recipients when re-challenged with allogeneic donor antigens. Our results demonstrate that one-time Trx-priming of donor lung grafts prior to transplantation significantly prolongs the survival of the grafts through inducing or promoting cellular and humoral alloantigen-specific immune tolerance, which might be associated with the induction of

  6. TaALMT1 promoter sequence compositions, acid tolerance, and Al tolerance in wheat cultivars and landraces from Sichuan in China.

    Science.gov (United States)

    Han, C; Dai, S F; Liu, D C; Pu, Z J; Wei, Y M; Zheng, Y L; Wen, D J; Zhao, L; Yan, Z H

    2013-11-18

    Previous genetic studies on wheat from various sources have indicated that aluminum (Al) tolerance may have originated independently in USA, Brazil, and China. Here, TaALMT1 promoter sequences of 92 landraces and cultivars from Sichuan, China, were sequenced. Five promoter types (I', II, III, IV, and V) were observed in 39 cultivars, and only three promoter types (I, II, and III) were observed in 53 landraces. Among the wheat collections worldwide, only the Chinese Spring (CS) landrace native to Sichuan, China, carried the TaALMT1 promoter type III. Besides CS, two other Sichuan-bred landraces and six cultivars with TaALMT1 promoter type III were identified in this study. In the phylogenetic tree constructed based on the TaALMT1 promoter sequences, type III formed a separate branch, which was supported by a high bootstrap value. It is likely that TaALMT1 promoter type III originated from Sichuan-bred wheat landraces of China. In addition, the landraces with promoter type I showed the lowest Al tolerance among all landraces and cultivars. Furthermore, the cultivars with promoter type IV showed better Al tolerance than landraces with promoter type II. A comparison of acid tolerance and Al tolerance between cultivars and landraces showed that the landraces had better acid tolerance than the cultivars, whereas the cultivars showed better Al tolerance than the landraces. Moreover, significant difference in Al tolerance was also observed between the cultivars raised by the National Ministry of Agriculture and by Sichuan Province. Among the landraces from different regions, those from the East showed better acid tolerance and Al tolerance than those from the South and West of Sichuan. Additional Al-tolerant and acid-tolerant wheat lines were also identified.

  7. Ethnopoly promotes tolerance

    CERN Document Server

    CERN Bulletin

    2010-01-01

    On Friday 23 April, 225 primary school children from the eight schools in Meyrin-Cointrin and their accompanying adults took part in a big game of Ethnopoly. Private individuals, associations, administrations, shopkeepers and CERN all opened their doors to them to talk about their countries, their customs and what they are doing to promote tolerance and integration.   The CERN stand set up at ForumMeyrin for the Ethnopoly game. Scurrying from one place to another, the 10 and 11 year olds were made aware of the rich cultural diversity of their commune, which is home to 130 different nationalities. Physicists and engineers from CERN took up residence in the Forum Meyrin for the day in order to talk to the children about the advantages of international collaboration, a subject dear to the Organization's heart. They welcomed around fifty children in the course of the day, conveying to them a message of tolerance: despite their differences, the 10,000 scientists and other members of the CERN...

  8. Cytokines affecting CD4+T regulatory cells in transplant tolerance. II. Interferon gamma (IFN-γ) promotes survival of alloantigen-specific CD4+T regulatory cells.

    Science.gov (United States)

    Nomura, Masaru; Hodgkinson, Suzanne J; Tran, Giang T; Verma, Nirupama D; Robinson, Catherine; Plain, Karren M; Boyd, Rochelle; Hall, Bruce M

    2017-06-01

    CD4 + T cells that transfer alloantigen-specific transplant tolerance are short lived in culture unless stimulated with specific-donor alloantigen and lymphocyte derived cytokines. Here, we examined if IFN-γ maintained survival of tolerance transferring CD4 + T cells. Alloantigen-specific transplant tolerance was induced in DA rats with heterotopic adult PVG heart allografts by a short course of immunosuppression and these grafts functioned for >100days with no further immunosuppression. In previous studies, we found the CD4 + T cells from tolerant rats that transfer tolerance to an irradiated DA host grafted with a PVG heart, lose their tolerance transferring ability after 3days of culture, either with or without donor alloantigen, and effect rejection of specific-donor grafts. If cultures with specific-donor alloantigen are supplemented by supernatant from ConA activated lymphocytes the tolerance transferring cells survive, suggesting these cells depend on cytokines for their survival. In this study, we found addition of rIFN-γ to MLC with specific-donor alloantigen maintained the capacity of tolerant CD4 + T cells to transfer alloantigen-specific tolerance and their ability to suppress PVG allograft rejection mediated by co-administered naïve CD4 + T cells. IFN-γ suppressed the in vitro proliferation of tolerant CD4 + T cells. Tolerant CD4 + CD25 + T cells did not proliferate in MLC to PVG stimulator cells with no cytokine added, but did when IFN-γ was present. IFN-γ did not alter proliferation of tolerant CD4 + CD25 + T cells to third-party Lewis. Tolerant CD4 + CD25 + T cells' expression of IFN-γ receptor (IFNGR) was maintained in culture when IFN-γ was present. This study suggested that IFN-γ maintained tolerance mediating alloantigen-specific CD4 + CD25 + T cells. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  9. Ayurvedic Amalaki Rasayana promotes improved stress tolerance

    Indian Academy of Sciences (India)

    Ayurvedic Amalaki Rasayana promotes improved stress tolerance and thus ... and some otheringredients, and is used for general good health and healthy aging. ... Wild-type larvae/flies rearedon AR-supplemented food survived the various ...

  10. Systemic LPS Translocation Activates Cross-Presenting Dendritic Cells but Is Dispensable for the Breakdown of CD8+ T Cell Peripheral Tolerance in Irradiated Mice.

    Directory of Open Access Journals (Sweden)

    Gabriel Espinosa-Carrasco

    Full Text Available Lymphodepletion is currently used to enhance the efficacy of cytotoxic T lymphocyte adoptive transfer immunotherapy against cancer. This beneficial effect of conditioning regimens is due, at least in part, to promoting the breakdown of peripheral CD8+ T cell tolerance. Lymphodepletion by total body irradiation induces systemic translocation of commensal bacteria LPS from the gastrointestinal tract. Since LPS is a potent activator of the innate immune system, including antigen presenting dendritic cells, we hypothesized that LPS translocation could be required for the breakdown of peripheral tolerance observed in irradiated mice. To address this issue, we have treated irradiated mice with antibiotics in order to prevent LPS translocation and utilized them in T cell adoptive transfer experiments. Surprisingly, we found that despite of completely blocking LPS translocation into the bloodstream, antibiotic treatment did not prevent the breakdown of peripheral tolerance. Although irradiation induced the activation of cross-presenting CD8+ dendritic cells in the lymphoid tissue, LPS could not solely account for this effect. Activation of dendritic cells by mechanisms other than LPS translocation is sufficient to promote the differentiation of potentially autoreactive CD8+ T cells into effectors in irradiated mice. Our data indicate that LPS translocation is dispensable for the breakdown of CD8+ T cell tolerance in irradiated mice.

  11. Progesterone promotes maternal–fetal tolerance by reducing human maternal T‐cell polyfunctionality and inducing a specific cytokine profile

    Science.gov (United States)

    Eldershaw, Suzy A.; Inman, Charlotte F.; Coomarasamy, Aravinthan; Moss, Paul A. H.; Kilby, Mark D.

    2015-01-01

    Progesterone is a steroid hormone essential for the maintenance of human pregnancy, and its actions are thought to include promoting maternal immune tolerance of the semiallogenic fetus. We report that exposure of maternal T cells to progesterone at physiological doses induced a unique skewing of the cytokine production profile of CD4+ and CD8+ T cells, with reductions not only in potentially deleterious IFN‐γ and TNF‐α production but also in IL‐10 and IL‐5. Conversely, production of IL‐4 was increased. Maternal T cells also became less polyfunctional, focussing cytokine production toward profiles including IL‐4. This was accompanied by reduced T‐cell proliferation. Using fetal and viral antigen‐specific CD8+ T‐cell clones, we confirmed that this as a direct, nonantigen‐specific effect. Yet human T cells lacked conventional nuclear progesterone receptors, implicating a membrane progesterone receptor. CD4+ and CD8+ T cells responded to progesterone in a dose‐dependent manner, with subtle effects at concentrations comparable to those in maternal blood, but profound effects at concentrations similar to those at the maternal–fetal interface. This characterization of how progesterone modulates T‐cell function is important in understanding the normal biology of pregnancy and informing the rational use of progesterone therapy in pregnancies at risk of fetal loss. PMID:26249148

  12. Selection of D-Alanine-Tolerant Rice Cells

    OpenAIRE

    Hisashi, Manabe; Koji, Ohira; Aizu Junior College of Fukushima Prefecture; Department of Agricultural Chemistry, Faculty of Agriculture, Tohoku University

    1984-01-01

    By repeating subculture of rice cells (parent cells) in a D-alanine containing medium, we could select rice cells which grew well in the D-alanine medium. The D-alanine-tolerant cells absorbed a fairly small amount of D-alanine from the medium and did not accumulate much D-alanine in the cells. Aggregation of D-alanine-tolerant cells was greater than that of parent cells. D-Alanine metabolism of D-alanine.-tolerant cells did not increase in comparison with parent cells.

  13. Engineering tolerance using biomaterials to target and control antigen presenting cells.

    Science.gov (United States)

    Tostanoski, Lisa H; Gosselin, Emily A; Jewell, Christopher M

    2016-05-01

    Autoimmune diseases occur when cells of the adaptive immune system incorrectly recognize and attack "self" tissues. Importantly, the proliferation and differentiation of these cells is triggered and controlled by interactions with antigen presenting cells (APCs), such as dendritic cells. Thus, modulating the signals transduced by APCs (e.g., cytokines, costimulatory surface proteins) has emerged as a promising strategy to promote tolerance for diseases such as multiple sclerosis, type 1 diabetes, and lupus. However, many approaches have been hindered by non-specific activity of immunosuppressive or immunoregulatory cues, following systemic administration of soluble factors via traditional injections routes (e.g., subcutaneous, intravenous). Biomaterials offer a unique opportunity to control the delivery of tolerogenic signals in vivo via properties such as controlled particle size, tunable release kinetics, and co-delivery of multiple classes of cargo. In this review, we highlight recent reports that exploit these properties of biomaterials to target APCs and promote tolerance via three strategies, i) passive or active targeting of particulate carriers to APCs, ii) biomaterial-mediated control over antigen localization and processing, and iii) targeted delivery of encapsulated or adsorbed immunomodulatory signals. These reports represent exciting advances toward the goal of more effective therapies for autoimmune diseases, without the broad suppressive effects associated with current clinically-approved therapies.

  14. Kaempferol Promotes Transplant Tolerance by Sustaining CD4+FoxP3+ Regulatory T Cells in the Presence of Calcineurin Inhibitor.

    Science.gov (United States)

    Zeng, Y Q; Liu, X S; Wu, S; Zou, C; Xie, Q; Xu, S M; Jin, X W; Li, W; Zhou, A; Dai, Z

    2015-07-01

    Calcineurin inhibitor cyclosporine is widely used as an immunosuppressant in clinic. However, mounting evidence has shown that cyclosporine hinders tolerance induction by dampening Tregs. Therefore, it is of paramount importance to overcome this pitfall. Kaempferol was reported to inhibit DC function. Here, we found that kaempferol delayed islet allograft rejection. Combination of kaempferol and low-dose, but not high-dose, of cyclosporine induced allograft tolerance in majority of recipient mice. Although kaempferol plus either dose of cyclosporine largely abrogated proliferation of graft-infiltrating T cells and their CTL activity, both proliferation and CTL activity in mice treated with kaempferol plus low-dose, but not high-dose, cyclosporine reemerged rapidly upon treatment withdrawal. Kaempferol increased CD4+FoxP3+ Tregs both in transplanted mice and in vitro, likely by suppressing DC maturation and their IL-6 expression. Reduction in Tregs by low dose of cyclosporine was reversed by kaempferol. Kaempferol-induced Tregs exhibited both allospecific and non-allospecific suppression. Administering IL-6 abrogated allograft tolerance induced by kaempferol and cyclosporine via diminishing CD4+FoxP3+ Tregs. Thus, for the first time, we demonstrated that kaempferol promotes transplant tolerance in the presence of low dose of cyclosporine, which allows for sufficient Treg generation while minimizing side effects, resulting in much-needed synergy between kaempferol and cyclosporine. © Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons.

  15. Suppressor cells in transplantation tolerance: I. analysis of the suppressor status of neonatally and adoptively tolerized rats

    International Nuclear Information System (INIS)

    Dorsch, S.; Roser, B.

    1982-01-01

    The lymphocytes from neonatally tolerant rats which adoptively transfer tolerance to sublethally irradiated recipients do so by specificallly suppressing the regeneration of alloreactivity which normally occurs after irradiation. Although tolerant cells will only partially suppress normal alloreactive cells when the two are mixed in near equivalent numbers, experiments in which the interval between injection of tolerant and normal cells into irradiated recipients was gradually extended, indicated that total suppression of normally alloreactive cells was achieved after 8 weeks of prior residence of tolerant cells in the adoptive host. Further evidence that tolerant cells would only suppress if present in excess of normal cells was obtained by reducing the tolerant cell populaton in tolerant donor rats by whole body irradiation. The persistence of tolerance through repeated adoptive transfers was correlated with the persistence of donor (chimeric) cells and the indicator skin graft on adoptive recipients only amplified tolerance expression where the inocula of tolerant cells given was weakly suppressive

  16. Suppressor cells in transplantation tolerance. I. Analysis of the suppressor status of neonatally and adoptively tolerized rats

    International Nuclear Information System (INIS)

    Dorsch, S.; Roser, B.

    1982-01-01

    The lymphocytes from neonatally tolerant rats which adoptively transfer tolerance to sublethally irradiated recipients do so by specifically suppressing the regeneration of alloreactivity which normally occurs after irradiation. Although tolerant cells will only partially suppress normal alloreactive cells when the two are mixed in near equivalent numbers, experiments in which the interval between injection of tolerant and normal cells into irradiated recipients was gradually extended, indicated that total suppression of normally alloreactive cells was achieved after 8 weeks of prior residence of tolerant cells in the adoptive host. Further evidence that tolerant cells would only suppress if present in excess of normal cells was obtained by reducing the tolerant cell population in tolerant donor rats by whole body irradiation. These animals then lost their ability to suppress normal alloreactive cells administered to them. The immune status of adoptively tolerized animals did not mimic that of the donors of the tolerant cells. Even where full tolerance, as measured by skin graft survival, failure to synthesize alloantibodies, and capacity to further transfer skin graft tolerance to secondary recipients, was evident the lymphocytes of these animals showed considerable graft-versus-host (GVH) reactivity. The persistence of tolerance through repeated adoptive transfers was correlated with the persistence of donor (chimeric) cells and the indicator skin graft on adoptive recipients only amplified tolerance expression where the inocula of tolerant cells given was weakly suppressive. Finally, removal of the minor population of chimeric cells from tolerant inocula using cytotoxic alloantisera abolished the capacity to transfer tolerance. These results imply an active role for chimeric cells which is best understood as an immune response involving proliferation driven by the idiotypes of the alloreceptors on host cells

  17. Progesterone promotes maternal-fetal tolerance by reducing human maternal T-cell polyfunctionality and inducing a specific cytokine profile.

    Science.gov (United States)

    Lissauer, David; Eldershaw, Suzy A; Inman, Charlotte F; Coomarasamy, Aravinthan; Moss, Paul A H; Kilby, Mark D

    2015-10-01

    Progesterone is a steroid hormone essential for the maintenance of human pregnancy, and its actions are thought to include promoting maternal immune tolerance of the semiallogenic fetus. We report that exposure of maternal T cells to progesterone at physiological doses induced a unique skewing of the cytokine production profile of CD4(+) and CD8(+) T cells, with reductions not only in potentially deleterious IFN-γ and TNF-α production but also in IL-10 and IL-5. Conversely, production of IL-4 was increased. Maternal T cells also became less polyfunctional, focussing cytokine production toward profiles including IL-4. This was accompanied by reduced T-cell proliferation. Using fetal and viral antigen-specific CD8(+) T-cell clones, we confirmed that this as a direct, nonantigen-specific effect. Yet human T cells lacked conventional nuclear progesterone receptors, implicating a membrane progesterone receptor. CD4(+) and CD8(+) T cells responded to progesterone in a dose-dependent manner, with subtle effects at concentrations comparable to those in maternal blood, but profound effects at concentrations similar to those at the maternal-fetal interface. This characterization of how progesterone modulates T-cell function is important in understanding the normal biology of pregnancy and informing the rational use of progesterone therapy in pregnancies at risk of fetal loss. © 2015 The Authors. European Journal of Immunology published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Surface Expression of TGF-β Docking Receptor GARP Promotes Oncogenesis and Immune Tolerance in Breast Cancer

    OpenAIRE

    Metelli, Alessandra; Wu, Bill X; Fugle, Caroline W; Rachidi, Saleh; Sun, Shaoli; Zhang, Yongliang; Wu, Jennifer; Tomlinson, Stephen; Howe, Philip; Yang, Yi; Garrett-Mayer, Elizabeth; Liu, Bei; Li, Zihai

    2016-01-01

    GARP encoded by the Lrrc32 gene is the cell surface docking receptor for latent TGF-β which is expressed naturally by platelets and regulatory T cells. Although Lrrc32 is amplified frequently in breast cancer, the expression and relevant functions of GARP in cancer have not been explored. Here we report that GARP exerts oncogenic effects, promoting immune tolerance by enriching and activating latent TGF-β in the tumor microenvironment. We found that human breast, lung and colon cancers expres...

  19. Differential sensitivity of regulatory and effector T cells to cell death: a prerequisite for transplant tolerance

    Directory of Open Access Journals (Sweden)

    Sylvaine eYou

    2015-05-01

    Full Text Available Despite significant progress achieved in transplantation, immunosuppressive therapies currently used to prevent graft rejection are still endowed with severe side effects impairing their efficiency over the long term. Thus, the development of graft-specific, non toxic innovative therapeutic strategies has become a major challenge, the goal being to selectively target alloreactive effector T cells while sparing CD4+Foxp3+ regulatory T cells (Tregs to promote operational tolerance. Various approaches, notably the one based on monoclonal antibodies or fusion proteins directed against the TCR/CD3 complex, TCR coreceptors, or costimulatory molecules, have been proposed to reduce the alloreactive T cell pool which is an essential prerequisite to create a therapeutic window allowing Tregs to induce and maintain allograft tolerance. In this minireview, we focus on the differential sensitivity of Tregs and effector T cells to the depleting and inhibitory effect of these immunotherapies, with a particular emphasis on CD3-specific antibodies that beyond their immunosuppressive effect, also express potent tolerogenic capacities.

  20. Promoting tolerance and moral engagement through peer modeling.

    Science.gov (United States)

    McAlister, A L; Ama, E; Barroso, C; Peters, R J; Kelder, S

    2000-11-01

    Behavioral journalism influences audiences by presenting peer modeling for cognitive processes that lead to behavior change. This technique was used in student newsletters promoting intergroup tolerance and moral engagement in a Houston high school with a diverse ethnic composition. Pretest (N = 393) and posttest (N = 363) cross-sectional comparisons of the student population in that school provided evidence of short-term (6 month) communication effects on attitudes and behavior. Tolerance and moral engagement increased among students in the school where behavioral journalism newsletters were distributed, and there was a corresponding reduction in hostile behavioral intentions and in reports of verbal aggression.

  1. Halotolerant rhizobacteria promote growth and enhance salinity tolerance in peanut

    Directory of Open Access Journals (Sweden)

    Sandeep Sharma

    2016-10-01

    Full Text Available Use of Plant growth promoting rhizobacteria (PGPR is a promising strategy to improve the crop production under optimal or sub-optimal conditions. In the present study, five diazotrophic salt tolerant bacteria were isolated from the roots of a halophyte, Arthrocnemum indicum. The isolates were partially characterized in vitro for plant growth promoting traits and evaluated for their potential to promote growth and enhanced salt tolerance in peanut. The 16S rRNA gene sequence homology indicated that these bacterial isolates belong to the genera, Klebisiella, Pseudomonas, Agrobacterium and Ochrobactrum. All isolates were nifH positive and able to produce indole -3-acetic acid (ranging from 11.5 to 19.1 µg ml-1. The isolates showed phosphate solubilisation activity (ranging from 1.4 to 55.6 µg phosphate /mg dry weight, 1-aminocyclopropane-1-carboxylate deaminase activity (0.1 to 0.31 µmol α-kB/µg protein/h and were capable of reducing acetylene in acetylene reduction assay (ranging from 0.95 to 1.8 µmol C2H4 mg protein/h. These isolates successfully colonized the peanut roots and were capable of promoting the growth under non-stress condition. A significant increase in total nitrogen (N content (up to 76% was observed over the non-inoculated control. All isolates showed tolerance to NaCl ranging from 4-8% in nutrient broth medium. Under salt stress, inoculated peanut seedlings maintained ion homeostasis, accumulated less reactive oxygen species (ROS and showed enhanced growth compared to non-inoculated seedlings. Overall, the present study has characterized several potential bacterial strains that showed an enhanced growth promotion effect on peanut under control as well as saline conditions. The results show the possibility to reduce chemical fertilizer inputs and may promote the use of bio-inoculants.

  2. Transplantation Tolerance Induction: Cell Therapies and their Mechanisms

    Directory of Open Access Journals (Sweden)

    Joseph R Scalea

    2016-03-01

    Full Text Available Cell based therapies have been studied extensively in the context of transplantation tolerance induction. The most successful protocols have relied on transfusion of bone marrow prior to the transplantation of a renal allograft. However, it is not clear that stem cells found in bone marrow are required in order to render a transplant candidate immunologically tolerant. Accordingly, mesenchymal stem cells, regulatory myeloid cells, T regulatory cells, and other cell types, are being tested as possible routes to tolerance induction, in the absence of donor derived stem cells. Early data with each of these cell types have been encouraging. However, the induction regimen capable of achieving consistent tolerance, whilst avoiding unwanted sided effects, and which is scalable to the human patient, has yet to be identified. Here we present the status of investigations of various tolerogenic cell types and the mechanistic rationale for their use in in tolerance induction protocols.

  3. Revisiting the phenotypic and genetic profiling of anergic T cells mediating long-term transplant tolerance.

    Science.gov (United States)

    You, Sylvaine; Chatenoud, Lucienne

    2018-02-01

    Herein our focus will be to revisit peripheral tolerance mechanisms and in particular 'active' or 'dominant' tolerance as originally defined and mediated by regulatory CD4FoxP3 T lymphocytes (Treg) and also T-cell anergy that appears as a major mainstay to support long-term allograft survival. It is at the same time interesting and rewarding that the tool that recently guided our efforts along this path is the in-vivo use of CD3 antibody, the first monoclonal introduced in the clinic (Orthoclone OKT3) about 35 years ago to treat and prevent rejection of renal allografts. Beyond their immunosuppressive activity, whenever administered judiciously, CD3 antibodies promote robust allograft tolerance through selective purging of alloreactive effectors, resetting Treg-mediated active tolerance and promoting a unique subset of anergic CD8 T cells. The new findings discussed open up new perspectives from both a fundamental and a clinical point of view. In basic research, concrete molecular signaling paths are now spotted to finely dissect the conditions that lead to the establishment and maintenance of robust T-lymphocyte anergy mediating allograft tolerance. In the clinic, this may rapidly translate into novel biomarkers to be used in parallel to the ones already available, to better adapt posttransplant immunotherapy and monitor for long-term allograft acceptance.

  4. Mast cell degranulation breaks peripheral tolerance.

    Science.gov (United States)

    de Vries, V C; Wasiuk, A; Bennett, K A; Benson, M J; Elgueta, R; Waldschmidt, T J; Noelle, R J

    2009-10-01

    Mast cells (MC) have been shown to mediate regulatory T-cell (T(reg))-dependent, peripheral allograft tolerance in both skin and cardiac transplants. Furthermore, T(reg) have been implicated in mitigating IgE-mediated MC degranulation, establishing a dynamic, reciprocal relationship between MC and T(reg) in controlling inflammation. In an allograft tolerance model, it is now shown that intragraft or systemic MC degranulation results in the transient loss of T(reg) suppressor activities with the acute, T-cell dependent rejection of established, tolerant allografts. Upon degranulation, MC mediators can be found in the skin, T(reg) rapidly leave the graft, MC accumulate in the regional lymph node and the T(reg) are impaired in the expression of suppressor molecules. Such a dramatic reversal of T(reg) function and tissue distribution by MC degranulation underscores how allergy may causes the transient breakdown of peripheral tolerance and episodes of acute T-cell inflammation.

  5. Regulatory T cells: serious contenders in the promise for immunological tolerance in transplantation

    Directory of Open Access Journals (Sweden)

    Niloufar eSafinia

    2015-08-01

    Full Text Available Regulatory T cells (Tregs play an important role in immunoregulation and have been shown in animal models to promote transplantation tolerance and curb autoimmunity following their adoptive transfer. The safety and potential therapeutic efficacy of these cells has already been reported in Phase I trials of bone marrow transplantation and type I diabetes, the success of which has motivated the broadened application of these cells in solid organ transplantation. Despite major advances in the clinical translation of these cells, there are still key questions to be addressed to ensure that Tregs attest their reputation as ideal candidates for tolerance induction. In this review, we will discuss the unique traits of Tregs that have attracted such fame in the arena of tolerance induction. We will outline the protocols used for their ex vivo expansion and discuss the future directions of Treg cell therapy. In this regard, we will review the concept of Treg heterogeneity, the desire to isolate and expand a functionally superior Treg population and report on the effect of differing culture conditions. The relevance of Treg migratory capacity will also be discussed together with methods of in vivo visualization of the infused cells. Moreover, we will highlight key advances in the identification and expansion of antigen specific Tregs and discuss their significance for cell therapy application. We will also summarize the clinical parameters that are of importance, alongside cell manufacture, from the choice of immunosuppression regimens to the number of injections in order to direct the success of future efficacy trials of Treg cell therapy.Years of research in the field of tolerance have seen an accumulation of knowledge and expertise in the field of Treg biology. This perpetual progression has been the driving force behind the many successes to date and has put us now within touching distance of our ultimate success, immunological tolerance.

  6. Surface Expression of TGF-β Docking Receptor GARP Promotes Oncogenesis and Immune Tolerance in Breast Cancer

    Science.gov (United States)

    Metelli, Alessandra; Wu, Bill X; Fugle, Caroline W; Rachidi, Saleh; Sun, Shaoli; Zhang, Yongliang; Wu, Jennifer; Tomlinson, Stephen; Howe, Philip; Yang, Yi; Garrett-Mayer, Elizabeth; Liu, Bei; Li, Zihai

    2016-01-01

    GARP encoded by the Lrrc32 gene is the cell surface docking receptor for latent TGF-β which is expressed naturally by platelets and regulatory T cells. Although Lrrc32 is amplified frequently in breast cancer, the expression and relevant functions of GARP in cancer have not been explored. Here we report that GARP exerts oncogenic effects, promoting immune tolerance by enriching and activating latent TGF-β in the tumor microenvironment. We found that human breast, lung and colon cancers expressed GARP aberrantly. In genetic studies in normal mammary gland epithelial and carcinoma cells, GARP expression increased TGF-β bioactivity and promoted malignant transformation in immune deficient mice. In breast carcinoma-bearing mice that were immune competent, GARP overexpression promoted Foxp3+ regulatory T cell activity, which in turn contributed to enhancing cancer progression and metastasis. Notably, administration of a panel of GARP-specific monoclonal antibodies limited metastasis in an orthotopic model of human breast cancer. Overall, these results define the oncogenic effects of the GARP-TGF-β axis in the tumor microenvironment and suggest mechanisms that might be exploited for diagnostic and therapeutic purposes. PMID:27913437

  7. Surface Expression of TGFβ Docking Receptor GARP Promotes Oncogenesis and Immune Tolerance in Breast Cancer.

    Science.gov (United States)

    Metelli, Alessandra; Wu, Bill X; Fugle, Caroline W; Rachidi, Saleh; Sun, Shaoli; Zhang, Yongliang; Wu, Jennifer; Tomlinson, Stephen; Howe, Philip H; Yang, Yi; Garrett-Mayer, Elizabeth; Liu, Bei; Li, Zihai

    2016-12-15

    GARP encoded by the Lrrc32 gene is the cell surface docking receptor for latent TGFβ, which is expressed naturally by platelets and regulatory T cells (Treg). Although Lrrc32 is amplified frequently in breast cancer, the expression and relevant functions of GARP in cancer have not been explored. Here, we report that GARP exerts oncogenic effects, promoting immune tolerance by enriching and activating latent TGFβ in the tumor microenvironment. We found that human breast, lung, and colon cancers expressed GARP aberrantly. In genetic studies in normal mammary gland epithelial and carcinoma cells, GARP expression increased TGFβ bioactivity and promoted malignant transformation in immunodeficient mice. In breast carcinoma-bearing mice that were immunocompetent, GARP overexpression promoted Foxp3 + Treg activity, which in turn contributed to enhancing cancer progression and metastasis. Notably, administration of a GARP-specific mAb limited metastasis in an orthotopic model of human breast cancer. Overall, these results define the oncogenic effects of the GARP-TGFβ axis in the tumor microenvironment and suggest mechanisms that might be exploited for diagnostic and therapeutic purposes. Cancer Res; 76(24); 7106-17. ©2016 AACR. ©2016 American Association for Cancer Research.

  8. Bacterial cells with improved tolerance to polyamines

    DEFF Research Database (Denmark)

    2017-01-01

    Provided are bacterial cells genetically modified to improve their tolerance to certain commodity chemicals, such as polyamines, and methods of preparing and using such bacterial cells for production of polyamines and other compounds.......Provided are bacterial cells genetically modified to improve their tolerance to certain commodity chemicals, such as polyamines, and methods of preparing and using such bacterial cells for production of polyamines and other compounds....

  9. Activation of CHK1 in Supporting Cells Indirectly Promotes Hair Cell Survival

    Directory of Open Access Journals (Sweden)

    Azadeh Jadali

    2017-05-01

    Full Text Available The sensory hair cells of the inner ear are exquisitely sensitive to ototoxic insults. Loss of hair cells after exposure to ototoxic agents causes hearing loss. Chemotherapeutic agents such as cisplatin causes hair cell loss. Cisplatin forms DNA mono-adducts as well as intra- and inter-strand DNA crosslinks. DNA cisplatin adducts are repaired through the DNA damage response. The decision between cell survival and cell death following DNA damage rests on factors that are involved in determining damage tolerance, cell survival and apoptosis. Cisplatin damage on hair cells has been the main focus of many ototoxic studies, yet the effect of cisplatin on supporting cells has been largely ignored. In this study, the effects of DNA damage response in cochlear supporting cells were interrogated. Supporting cells play a major role in the development, maintenance and oto-protection of hair cells. Loss of supporting cells may indirectly affect hair cell survival or maintenance. Activation of the Phosphoinositide 3-Kinase (PI3K signaling was previously shown to promote hair cell survival. To test whether activating PI3K signaling promotes supporting cell survival after cisplatin damage, cochlear explants from the neural subset (NS Cre Pten conditional knockout mice were employed. Deletion of Phosphatase and Tensin Homolog (PTEN activates PI3K signaling in multiple cell types within the cochlea. Supporting cells lacking PTEN showed increased cell survival after cisplatin damage. Supporting cells lacking PTEN also showed increased phosphorylation of Checkpoint Kinase 1 (CHK1 levels after cisplatin damage. Nearest neighbor analysis showed increased numbers of supporting cells with activated PI3K signaling in close proximity to surviving hair cells in cisplatin damaged cochleae. We propose that increased PI3K signaling promotes supporting cell survival through phosphorylation of CHK1 and increased survival of supporting cells indirectly increases hair cell

  10. B cells in operational tolerance.

    Science.gov (United States)

    Chesneau, M; Danger, R; Soulillou, J-P; Brouard, S

    2018-02-16

    Transplantation is currently the therapy of choice for endstage organ failure even though it requires long-term immunosuppresive therapy, with its numerous side effects, for acceptance of the transplanted organ. In rare cases however, patients develop operational tolerance, that is, graft survival without immunosuppression. Studies conducted on these patients reveal genetic, phenotypic, and functional signatures. They provide a better understanding of the immunological mechanisms involved in operational tolerance and define biomarkers that could be used to adapt immunosuppressive treatment to the individual, safely reduce immunosuppression doses, and ideally and safely guide immunosuppression withdrawal. This review summarizes studies that suggest a role for B cells as biomarkers of operational tolerance and discusses the use of B cells as a predictive tool for immunologic risk. Copyright © 2018. Published by Elsevier Inc.

  11. Dendritic cells in oral tolerance in the gut.

    Science.gov (United States)

    Rescigno, Maria

    2011-09-01

    Oral tolerance is a process that allows generation of systemic unresponsiveness to food antigens. Hence if the same antigen is introduced systemically even under immunogenic conditions it does not induce immune responsiveness. Dendritic cells (DCs) have been identified as essential players in this process. DCs in the gut are located in a strategic position as they can interact directly with luminal antigens or indirectly after their transcytosis across epithelial cells. DCs can then migrate to associated lymphoid tissues to induce tolerance. Antigen presenting cells in the gut are specialized in function and have divided their labour so that there are cells capable to migrate to the draining mesenteric lymph node for induction of T regulatory cells, while other subsets are resident and are required to enforce tolerance locally in the gut after food antigen exposure. In this review, I shall summarize the characteristics of antigen presenting cells in the gut and their involvement in oral tolerance induction. In addition, I will also emphasize that tolerance to food allergens may be contributed by plasmacytoid DCs in the liver that participate to the elimination or anergy of allergen-specific CD8 T cells. Hence specialized functions are associated to different subsets of antigen presenting cells and different organs. © 2011 Blackwell Publishing Ltd.

  12. The enigmatic role of mast cells in dominant tolerance.

    Science.gov (United States)

    de Vries, Victor C; Pino-Lagos, Karina; Elgueta, Raul; Noelle, Randolph J

    2009-08-01

    The role of regulatory T cells (Treg) in peripheral tolerance has been studied extensively in transplantation research. Recently, mast cells have been shown to play an indispensable role in allograft tolerance. The purpose of this review is to inform the reader on the current standings of the role of mast cells in dominant tolerance with an emphasis on the interaction of mast cells with Treg. Mast cells are required to sustain peripheral tolerance via Treg. Treg can stabilize mast cells degranulation by contact-dependent mechanisms through the interaction of OX40 and its ligand OX40L, and by production of soluble factors, such as interleukin-10 and transforming growth factor-beta. Conversely, the activation and subsequent degranulation of mast cells break peripheral tolerance. Both mast cells and Treg are needed to create a local immunosuppressive environment in the transplant. Treg are not only necessary to suppress effector T-cell responses but also to stabilize mast cells. Mast cells in return could contribute to the immunosuppressive state by release of transforming growth factor-beta, interleukin-10 and specific proteases. However, the molecular basis for mast cells control of Treg suppression in organ transplantation is still unresolved.

  13. Role of donor lymphoid cells in the transfer of allograft tolerance

    International Nuclear Information System (INIS)

    Pierce, G.E.; Watts, L.M.

    1985-01-01

    Tolerance to murine skin allografts across a MHC disparity was induced by conditioning primary hosts with sublethal fractionated total-body irradiation (FTBI) and transfusion of allogeneic bone marrow (BM). Tolerance could be adoptively transferred to secondary hosts conditioned by FTBI with infusion of spleen cells from hosts bearing intact skin allografts greater than 60 days. Tolerance could not be transferred by tolerant host spleen (THS) preparations from which cells of the donor genotype had been deleted by cytotoxic alloantisera. Deletion of host genotype cells, however, did not diminish the capability of THS to transfer tolerance. All of the tolerizing activity of THS appeared to reside within cells of the donor genotype. Small numbers of normal donor spleen cells could induce tolerance in FTBI hosts but only at the expense of very high mortality, in contrast to the low mortality observed with tolerizing injections of allogeneic donor cells from THS or injections of normal semiallogeneic F1 hybrid spleen cells. If an active immune response is responsible for tolerance induction/transfer in this model, allogeneic donor lymphoid cells derived from BM, in contrast to donor spleen cells, must be capable of mounting this response without concomitant severe GVHD. In future experiments, cells of donor genotype can be isolated from THS and purified in sufficient numbers to compare their tolerizing efficiency vs. that of normal donor cells, detect possible suppression of normal host cell alloreactivity in vitro and identify the donor cell phenotypes involved

  14. Bacterial cells with improved tolerance to polyols

    DEFF Research Database (Denmark)

    2017-01-01

    The present invention relates to bacterial cells genetically modified to improve their tolerance to certain commodity chemicals, such as diols and other polyols, and to methods of preparing and using such bacterial cells for production of polyols and other compounds.......The present invention relates to bacterial cells genetically modified to improve their tolerance to certain commodity chemicals, such as diols and other polyols, and to methods of preparing and using such bacterial cells for production of polyols and other compounds....

  15. Proglucagon Promoter Cre-Mediated AMPK Deletion in Mice Increases Circulating GLP-1 Levels and Oral Glucose Tolerance.

    Directory of Open Access Journals (Sweden)

    Sophie R Sayers

    Full Text Available Enteroendocrine L-cells synthesise and release the gut hormone glucagon-like peptide-1 (GLP-1 in response to food transit. Deletion of the tumour suppressor kinase LKB1 from proglucagon-expressing cells leads to the generation of intestinal polyps but no change in circulating GLP-1 levels. Here, we explore the role of the downstream kinase AMP-activated protein kinase (AMPK in these cells.Loss of AMPK from proglucagon-expressing cells was achieved using a preproglucagon promoter-driven Cre (iGluCre to catalyse recombination of floxed alleles of AMPKα1 and α2. Oral and intraperitoneal glucose tolerance were measured using standard protocols. L-cell mass was measured by immunocytochemistry. Hormone and peptide levels were measured by electrochemical-based luminescence detection or radioimmunoassay.Recombination with iGluCre led to efficient deletion of AMPK from intestinal L- and pancreatic alpha-cells. In contrast to mice rendered null for LKB1 using the same strategy, mice deleted for AMPK displayed an increase (WT: 0.05 ± 0.01, KO: 0.09±0.02%, p<0.01 in L-cell mass and elevated plasma fasting (WT: 5.62 ± 0.800 pg/ml, KO: 14.5 ± 1.870, p<0.01 and fed (WT: 15.7 ± 1.48pg/ml, KO: 22.0 ± 6.62, p<0.01 GLP-1 levels. Oral, but not intraperitoneal, glucose tolerance was significantly improved by AMPK deletion, whilst insulin and glucagon levels were unchanged despite an increase in alpha to beta cell ratio (WT: 0.23 ± 0.02, KO: 0.33 ± 0.03, p<0.01.AMPK restricts L-cell growth and GLP-1 secretion to suppress glucose tolerance. Targeted inhibition of AMPK in L-cells may thus provide a new therapeutic strategy in some forms of type 2 diabetes.

  16. Transplantation Tolerance Induction: Cell Therapies and Their Mechanisms

    OpenAIRE

    Scalea, Joseph R.; Tomita, Yusuke; Lindholm, Christopher R.; Burlingham, William

    2016-01-01

    Cell based therapies have been studied extensively in the context of transplantation tolerance induction. The most successful protocols have relied on transfusion of bone marrow prior to the transplantation of a renal allograft. However, it is not clear that stem cells found in bone marrow are required in order to render a transplant candidate immunologically tolerant. Accordingly, mesenchymal stem cells, regulatory myeloid cells, T regulatory cells, and other cell types, are being tested as ...

  17. Elevated levels of interferon-γ production by memory T cells do not promote transplant tolerance resistance in aged recipients.

    Directory of Open Access Journals (Sweden)

    James I Kim

    Full Text Available Immunosenescence predisposes the elderly to infectious and autoimmune diseases and impairs the response to vaccination. We recently demonstrated that ageing also impedes development of transplantation tolerance. Unlike their young counterparts (8-12 weeks of age aged male recipients (greater than 12 months of age transplanted with a full MHC-mismatched heart are resistant to tolerance mediated by anti-CD45RB antibody. Surprisingly, either chemical or surgical castration restored tolerance induction to levels observed using young recipients. Based on the strong impact of endocrine modulation on transplant tolerance, we explored the impact of ageing and castration on the immune system. Here we report a significant increase in the percentage of T cells that produce interferon-γ (IFN-γ in aged male versus young male animals and that the overall increase in IFN-γ production was due to an expansion of IFN-γ-producing memory T cells in aged animals. In contrast to IFN-γ production, we did not observe differences in IL-10 expression in young versus old male mice. We hypothesized that endocrine modulation would diminish the elevated levels of IFN-γ production in aged recipients, however, we observed no significant reduction in the percentage of IFN-γ+ T cells upon castration. Furthermore, we neutralized interferon-γ by antibody and did not observe an effect on graft survival. We conclude that while elevated levels of interferon-γ serves as a marker of tolerance resistance in aged mice, other as yet to be identified factors are responsible for its cause. Defining these factors may be relevant to design of tolerogenic strategies for aged recipients.

  18. Inhibition of HLA-DM mediated MHC class II peptide loading by HLA-DO promotes self tolerance

    Directory of Open Access Journals (Sweden)

    Lisa K. Denzin

    2013-12-01

    Full Text Available Major histocompatibility class II (MHCII molecules are loaded with peptides derived from foreign and self-proteins within the endosomes and lysosomes of antigen presenting cells (APCs. This process is mediated by interaction of MHCII with the conserved, nonpolymorphic MHCII-like molecule HLA-DM (DM. DM activity is directly opposed by HLA-DO (DO, another conserved, non-polymorphic MHCII like molecule. DO is an MHCII substrate mimic. Binding of DO to DM prevents MHCII from binding to DM, thereby inhibiting peptide loading. Inhibition of DM function enables low stability MHC complexes to survive and populate the surface of APCS. As a consequence, DO promotes the display of a broader pool of low abundance self-peptides. Broadening the peptide repertoire theoretically reduces the likelihood of inadvertently acquiring a density of self-ligands that is sufficient to activate self-reactive T cells. One function of DO, therefore, is to promote T cell tolerance by shaping the visible image of self. Recent data also shows that DO influences the adaptive immune response by controlling B cell entry into the germinal center reaction. This review explores the data supporting these concepts.

  19. Bacterial cells with improved tolerance to isobutyric acid

    DEFF Research Database (Denmark)

    2017-01-01

    Bacterial cells genetically modified to improve their tolerance to certain commodity chemicals, such as isobutyric acid and related compounds, and methods of preparing and using such bacterial cells for production of isobutyric acid and related compounds.......Bacterial cells genetically modified to improve their tolerance to certain commodity chemicals, such as isobutyric acid and related compounds, and methods of preparing and using such bacterial cells for production of isobutyric acid and related compounds....

  20. Glycogen synthase kinase-3 regulates inflammatory tolerance in astrocytes

    Science.gov (United States)

    Beurel, Eléonore; Jope, Richard S.

    2010-01-01

    Inflammatory tolerance is the down-regulation of inflammation upon repeated stimuli, which is well-established to occur in peripheral immune cells. However, less is known about inflammatory tolerance in the brain although it may provide an important protective mechanism from detrimental consequences of prolonged inflammation, which appears to occur in many psychiatric and neurodegenerative conditions. Array analysis of 308 inflammatory molecules produced by mouse primary astrocytes after two sequential stimulations with lipopolysaccharide (LPS) distinguished three classes, tolerant, sensitized and unaltered groups. For many of these inflammatory molecules, inhibition of glycogen synthase kinase-3 (GSK3) increased tolerance and reduced sensitization. Focusing on LPS-tolerance in interleukin-6 (IL-6) production, we found that microglia exhibited a strong tolerance response that matched that of macrophages, whereas astrocytes exhibited only partial tolerance. The astrocyte semi-tolerance was found to be regulated by GSK3. GSK3 inhibitors or knocking down GSK3 levels promoted LPS-tolerance and astrocytes expressing constitutively active GSK3 did not develop LPS-tolerance. These findings identify the critical role of GSK3 in counteracting IL-6 inflammatory tolerance in cells of the CNS, supporting the therapeutic potential of GSK3 inhibitors to reduce neuroinflammation by promoting tolerance. PMID:20553816

  1. IL-5 promotes induction of antigen-specific CD4+CD25+ T regulatory cells that suppress autoimmunity.

    Science.gov (United States)

    Tran, Giang T; Hodgkinson, Suzanne J; Carter, Nicole M; Verma, Nirupama D; Plain, Karren M; Boyd, Rochelle; Robinson, Catherine M; Nomura, Masaru; Killingsworth, Murray; Hall, Bruce M

    2012-05-10

    Immune responses to foreign and self-Ags can be controlled by regulatory T cells (Tregs) expressing CD4 and IL-2Rα chain (CD25). Defects in Tregs lead to autoimmunity, whereas induction of Ag-specific CD4+CD25+ Tregs restores tolerance. Ag-specific CD4+CD25+ FOXP3+Tregs activated by the T helper type 2 (Th2) cytokine, IL-4, and specific alloantigen promote allograft tolerance. These Tregs expressed the specific IL-5Rα and in the presence of IL-5 proliferate to specific but not third-party Ag. These findings suggest that recombinant IL-5 (rIL-5) therapy may promote Ag-specific Tregs to mediate tolerance. This study showed normal CD4+CD25+ Tregs cultured with IL-4 and an autoantigen expressed Il-5rα. Treatment of experimental autoimmune neuritis with rIL-5 markedly reduced clinical paralysis, weight loss, demyelination, and infiltration of CD4+ (Th1 and Th17) CD8+ T cells and macrophages in nerves. Clinical improvement was associated with expansion of CD4+CD25+FOXP3+ Tregs that expressed Il-5rα and proliferated only to specific autoantigen that was enhanced by rIL-5. Depletion of CD25+ Tregs or blocking of IL-4 abolished the benefits of rIL-5. Thus, rIL-5 promoted Ag-specific Tregs, activated by autoantigen and IL-4, to control autoimmunity. These findings may explain how Th2 responses, especially to parasitic infestation, induce immune tolerance. rIL-5 therapy may be able to induce Ag-specific tolerance in autoimmunity.

  2. Changes in Reactivity In Vitro of CD4+CD25+ and CD4+CD25− T Cell Subsets in Transplant Tolerance

    Science.gov (United States)

    Hall, Bruce M.; Robinson, Catherine M.; Plain, Karren M.; Verma, Nirupama D.; Tran, Giang T.; Nomura, Masaru; Carter, Nicole; Boyd, Rochelle; Hodgkinson, Suzanne J.

    2017-01-01

    Transplant tolerance induced in adult animals is mediated by alloantigen-specific CD4+CD25+ T cells, yet in many models, proliferation of CD4+ T cells from hosts tolerant to specific-alloantigen in vitro is not impaired. To identify changes that may diagnose tolerance, changes in the patterns of proliferation of CD4+, CD4+CD25+, and CD4+CD25− T cells from DA rats tolerant to Piebald Virol Glaxo rat strain (PVG) cardiac allografts and from naïve DA rats were examined. Proliferation of CD4+ T cells from both naïve and tolerant hosts was similar to both PVG and Lewis stimulator cells. In mixed lymphocyte culture to PVG, proliferation of naïve CD4+CD25− T cells was greater than naïve CD4+ T cells. In contrast, proliferation of CD4+CD25− T cells from tolerant hosts to specific-donor PVG was not greater than CD4+ T cells, whereas their response to Lewis and self-DA was greater than CD4+ T cells. Paradoxically, CD4+CD25+ T cells from tolerant hosts did not proliferate to PVG, but did to Lewis, whereas naïve CD4+CD25+ T cells proliferate to both PVG and Lewis but not to self-DA. CD4+CD25+ T cells from tolerant, but not naïve hosts, expressed receptors for interferon (IFN)-γ and IL-5 and these cytokines promoted their proliferation to specific-alloantigen PVG but not to Lewis or self-DA. We identified several differences in the patterns of proliferation to specific-donor alloantigen between cells from tolerant and naïve hosts. Most relevant is that CD4+CD25+ T cells from tolerant hosts failed to proliferate or suppress to specific donor in the absence of either IFN-γ or IL-5. The proliferation to third-party and self of each cell population from tolerant and naïve hosts was similar and not affected by IFN-γ or IL-5. Our findings suggest CD4+CD25+ T cells that mediate transplant tolerance depend on IFN−γ or IL-5 from alloactivated Th1 and Th2 cells. PMID:28878770

  3. 1Autoreactive pre-plasma cells break tolerance in the absence of regulation by dendritic cells and macrophages

    Science.gov (United States)

    Gilbert, Mileka R.; Wagner, Nikki J.; Jones, Shannon Z.; Wisz, Amanda B.; Roques, Jose R.; Krum, Kristen N.; Lee, Sang-Ryul; Nickeleit, Volker; Hulbert, Chrys; Thomas, James W.; Gauld, Stephen B.; Vilen, Barbara J.

    2012-01-01

    The ability to induce antibody responses to pathogens while maintaining the quiescence of autoreactive cells is an important aspect of immune tolerance. During activation of Toll-like receptor-4 (TLR4), dendritic cells (DCs) and macrophages (MFs) repress autoantibody production through their secretion of IL-6 and soluble CD40L (sCD40L). These soluble mediators selectively repress B cells chronically exposed to antigen, but not naïve cells, suggesting a means to maintain tolerance during TLR4 stimulation, yet allow immunity. In this study, we identify TNFα as a third repressive factor, which together with IL-6 and CD40L, account for nearly all the repression conferred by DCs and MFs. Like IL-6 and sCD40L, TNFα did not alter B cell proliferation or survival. Rather, it reduced the number of antibody secreting cells. To address whether the soluble mediators secreted by DCs and MFs functioned in vivo, we generated mice lacking IL-6, CD40L and TNFα. Compared to wildtype mice, these mice showed prolonged anti-nuclear antibody responses following TLR4 stimulation. Further, adoptive transfer of autoreactive B cells into chimeric IL-6-/- × CD40L-/- × TNFα-/- mice showed that pre-plasma cells secreted autoantibodies independent of germinal center formation or extrafollicular foci. These data indicate that in the absence of genetic predisposition to autoimmunity, loss of endogenous IL-6, CD40L, and TNFα promotes autoantibody secretion during TLR4 stimulation. PMID:22675201

  4. Plant growth promoting bacteria as an alternative strategy for salt tolerance in plants: A review.

    Science.gov (United States)

    Numan, Muhammad; Bashir, Samina; Khan, Yasmin; Mumtaz, Roqayya; Shinwari, Zabta Khan; Khan, Abdul Latif; Khan, Ajmal; Al-Harrasi, Ahmed

    2018-04-01

    Approximately 5.2 billion hectare agriculture land are affected by erosion, salinity and soil degradation. Salinity stress has significantly affecting the fertile lands, and therefore possesses a huge impact on the agriculture and economy of a country. Salt stress has severe effects on the growth and development of plants as well as reducing its yield. Plants are inherently equipped with stress tolerance ability to responds the specific type of stress. Plants retained specific mechanisms for salt stress mitigation, such as hormonal stimulation, ion exchange, antioxidant enzymes and activation of signaling cascades on their metabolic and genetic frontiers that sooth the stressed condition. Additional to the plant inherent mechanisms, certain plant growth promoting bacteria (PGPB) also have specialized mechanism that play key role for salt stress tolerance and plant growth promotion. These bacteria triggers plants to produce different plant growth hormones like auxin, cytokinine and gibberellin as well as volatile organic compounds. These bacteria also produces growth regulators like siderophore, which fix nitrogen, solubilize organic and inorganic phosphate. Considering the importance of PGPB in compensation of salt tolerance in plants, the present study has reviewed the different aspect and mechanism of bacteria that play key role in promoting plants growth and yield. It can be concluded that PGPB can be used as a cost effective and economical tool for salinity tolerance and growth promotion in plants. Copyright © 2018 Elsevier GmbH. All rights reserved.

  5. Salt tolerance at single cell level in giant-celled Characeae

    Directory of Open Access Journals (Sweden)

    Mary Jane eBeilby

    2015-04-01

    Full Text Available Characean plants provide an excellent experimental system for electrophysiology and physiology due to: (i very large cell size, (ii position on phylogenetic tree near the origin of land plants and (iii continuous spectrum from very salt sensitive to very salt tolerant species. A range of experimental techniques is described, some unique to characean plants. Application of these methods provided electrical characteristics of membrane transporters, which dominate the membrane conductance under different outside conditions. With this considerable background knowledge the electrophysiology of salt sensitive and salt tolerant genera can be compared under salt and/or osmotic stress. Both salt tolerant and salt sensitive Characeae show a rise in membrane conductance and simultaneous increase in Na+ influx upon exposure to saline medium. Salt tolerant Chara longifolia and Lamprothamnium sp. exhibit proton pump stimulation upon both turgor decrease and salinity increase, allowing the membrane PD to remain negative. The turgor is regulated through the inward K+ rectifier and 2H+/Cl- symporter. Lamprothamnium plants can survive in hypersaline media up to twice seawater strength and withstand large sudden changes in salinity. Salt-sensitive Chara australis succumbs to 50 - 100 mM NaCl in few days. Cells exhibit no pump stimulation upon turgor decrease and at best transient pump stimulation upon salinity increase. Turgor is not regulated. The membrane PD exhibits characteristic noise upon exposure to salinity. Depolarization of membrane PD to excitation threshold sets off trains of action potentials, leading to further loses of K+ and Cl-. In final stages of salt damage the H+/OH- channels are thought to become the dominant transporter, dissipating the proton gradient and bringing the cell PD close to 0. The differences in transporter electrophysiology and their synergy under osmotic and/or saline stress in salt sensitive and salt tolerant characean cells

  6. Cell motility and antibiotic tolerance of bacterial swarms

    Science.gov (United States)

    Zuo, Wenlong

    Many bacteria species can move across moist surfaces in a coordinated manner known as swarming. It is reported that swarm cells show higher tolerance to a wide variety of antibiotics than planktonic cells. We used the model bacterium E. coli to study how motility affects the antibiotic tolerance of swarm cells. Our results provide new insights for the control of pathogenic invasion via regulating cell motility. Mailing address: Room 306 Science Centre North Block, The Chinese University of Hong Kong, Shatin, N.T. Hong Kong SAR. Phone: +852-3943-6354. Fax: +852-2603-5204. E-mail: zwlong@live.com.

  7. Halophytes: Potential Resources for Salt Stress Tolerance Genes and Promoters.

    Science.gov (United States)

    Mishra, Avinash; Tanna, Bhakti

    2017-01-01

    Halophytes have demonstrated their capability to thrive under extremely saline conditions and thus considered as one of the best germplasm for saline agriculture. Salinity is a worldwide problem, and the salt-affected areas are increasing day-by-day because of scanty rainfall, poor irrigation system, salt ingression, water contamination, and other environmental factors. The salinity stress tolerance mechanism is a very complex phenomenon, and some pathways are coordinately linked for imparting salinity tolerance. Though a number of salt responsive genes have been reported from the halophytes, there is always a quest for promising stress-responsive genes that can modulate plant physiology according to the salt stress. Halophytes such as Aeluropus, Mesembryanthemum, Suaeda, Atriplex, Thellungiella, Cakile , and Salicornia serve as a potential candidate for the salt-responsive genes and promoters. Several known genes like antiporters ( NHX, SOS, HKT, VTPase ), ion channels (Cl - , Ca 2+ , aquaporins), antioxidant encoding genes ( APX, CAT, GST, BADH, SOD ) and some novel genes such as USP, SDR1, SRP etc. were isolated from halophytes and explored for developing stress tolerance in the crop plants (glycophytes). It is evidenced that stress triggers salt sensors that lead to the activation of stress tolerance mechanisms which involve multiple signaling proteins, up- or down-regulation of several genes, and finally the distinctive or collective effects of stress-responsive genes. In this review, halophytes are discussed as an excellent platform for salt responsive genes which can be utilized for developing salinity tolerance in crop plants through genetic engineering.

  8. Dendritic cells in peripheral tolerance and immunity

    DEFF Research Database (Denmark)

    Gad, Monika; Claesson, Mogens Helweg; Pedersen, Anders Elm

    2003-01-01

    Dendritic cells capable of influencing immunity exist as functionally distinct subsets, T cell-tolerizing and T cell-immunizing subsets. The present paper reviews how these subsets of DCs develop, differentiate and function in vivo and in vitro at the cellular and molecular level. In particular...

  9. B Cell Tolerance in Health and Disease

    Directory of Open Access Journals (Sweden)

    Murali Gururajan

    2014-02-01

    Full Text Available B lymphocyte receptors are generated randomly during the bone marrow developmental phase of B cells. Hence, the B cell repertoire consists of both self and foreign antigen specificities necessitating specific tolerance mechanisms to eliminate self-reactive B cells. This review summarizes the major mechanisms of B cell tolerance, which include clonal deletion, anergy and receptor editing. In the bone marrow presentation of antigen in membrane bound form is more effective than soluble form and the role of dendritic cells in this process is discussed. Toll like receptor derived signals affect activation of B cells by certain ligands such as nucleic acids and have been shown to play crucial roles in the development of autoimmunity in several animal models. In the periphery availability of BAFF, a B cell survival factor plays a critical role in the survival of self-reactive B cells. Antibodies against BAFF have been found to be effective therapeutic agents in lupus like autoimmune diseases. Recent developments are targeting anergy to control the growth of chronic lymphocytic leukemia cells.

  10. The MTP1 promoters from Arabidopsis halleri reveal cis-regulating elements for the evolution of metal tolerance.

    Science.gov (United States)

    Fasani, Elisa; DalCorso, Giovanni; Varotto, Claudio; Li, Mingai; Visioli, Giovanna; Mattarozzi, Monica; Furini, Antonella

    2017-06-01

    In the hyperaccumulator Arabidopsis halleri, the zinc (Zn) vacuolar transporter MTP1 is a key component of hypertolerance. Because protein sequences and functions are highly conserved between A. halleri and Arabidopsis thaliana, Zn tolerance in A. halleri may reflect the constitutively higher MTP1 expression compared with A. thaliana, based on copy number expansion and different cis regulation. Three MTP1 promoters were characterized in A. halleri ecotype I16. The comparison with the A. thaliana MTP1 promoter revealed different expression profiles correlated with specific cis-acting regulatory elements. The MTP1 5' untranslated region, highly conserved among A. thaliana, Arabidopsis lyrata and A. halleri, contains a dimer of MYB-binding motifs in the A. halleri promoters absent in the A. thaliana and A. lyrata sequences. Site-directed mutagenesis of these motifs revealed their role for expression in trichomes. A. thaliana mtp1 transgenic lines expressing AtMTP1 controlled by the native A. halleri promoter were more Zn-tolerant than lines carrying mutations on MYB-binding motifs. Differences in Zn tolerance were associated with different distribution of Zn among plant organs and in trichomes. The different cis-acting elements in the MTP1 promoters of A. halleri, particularly the MYB-binding sites, are probably involved in the evolution of Zn tolerance. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  11. Classical dendritic cells are required for dietary antigen-mediated peripheral regulatory T cell and tolerance induction

    Science.gov (United States)

    Esterházy, Daria; Loschko, Jakob; London, Mariya; Jove, Veronica; Oliveira, Thiago Y.; Mucida, Daniel

    2016-01-01

    Oral tolerance prevents pathological inflammatory responses towards innocuous foreign antigens via peripheral regulatory T cells (pTreg cells). However, whether a particular subset of antigen-presenting cells (APCs) is required during dietary antigen exposure to instruct naïve CD4+ T cells to differentiate into pTreg cells has not been defined. Using myeloid lineage-specific APC depletion in mice, we found that monocyte-derived APCs are dispensable, while classical dendritic cells (cDCs) are critical for pTreg cell induction and oral tolerance. CD11b− cDCs from the gut-draining lymph nodes efficiently induced pTreg cells, and conversely, loss of IRF8-dependent CD11b− cDCs impaired their polarization, although oral tolerance remained intact. These data reveal the hierarchy of cDC subsets in pTreg cell induction and their redundancy during oral tolerance development. PMID:27019226

  12. Activation of glioma cells generates immune tolerant NKT cells.

    Science.gov (United States)

    Tang, Bo; Wu, Wei; Wei, Xiaowei; Li, Yang; Ren, Gang; Fan, Wenhai

    2014-12-12

    Therapeutic outcomes of glioma are currently not encouraging. Tumor tolerance plays an important role in the pathogenesis of glioma. It is reported that micro RNAs (miR) are associated with tumor development. This study aims to investigate the role of miR-92a in the development of tolerant natural killer T (NKT) cells. In this study, U87 cells (a human glioma cell line) and primary glioma cells were prepared. The assessment of miR-92a was performed by real time RT-PCR. The expression of interleukin (IL)-10 and IL-6 in NKT cells was evaluated by flow cytometry. Results showed that abundant IL-6(+) IL-10(+) NKT cells were detected in glioma tissue. Cultures of glioma cells and NKT cells induced the expression of IL-6 and IL-10 in NKT cells. Glioma cells expressed miR-92a; the latter played a critical role in the induction of IL-6 and IL-10 expression in NKT cells. The expression of the antitumor molecules, including perforin, Fas ligand, and interferon-γ, was significantly attenuated compared with control NKT cells. The IL-6(+) IL-10(+) NKT cells showed less capability in the induction of apoptosis in glioma cells, but showed the immune suppressor functions on CD8(+) T cell activities. We conclude that glioma-derived miR-92a induces IL-6(+) IL-10(+) NKT cells; this fraction of NKT cells can suppress cytotoxic CD8(+) T cells. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  13. Tolerance through Education: How Tolerogenic Dendritic Cells Shape Immunity

    Directory of Open Access Journals (Sweden)

    Matthias P. Domogalla

    2017-12-01

    Full Text Available Dendritic cells (DCs are central players in the initiation and control of responses, regulating the balance between tolerance and immunity. Tolerogenic DCs are essential in the maintenance of central and peripheral tolerance by induction of clonal T cell deletion and T cell anergy, inhibition of memory and effector T cell responses, and generation and activation of regulatory T cells. Therefore, tolerogenic DCs are promising candidates for specific cellular therapy of allergic and autoimmune diseases and for treatment of transplant rejection. Studies performed in rodents have demonstrated the efficacy and feasibility of tolerogenic DCs for tolerance induction in various inflammatory diseases. In the last years, numerous protocols for the generation of human monocyte-derived tolerogenic DCs have been established and some first phase I trials have been conducted in patients suffering from autoimmune disorders, demonstrating the safety and efficiency of this cell-based immunotherapy. This review gives an overview about methods and protocols for the generation of human tolerogenic DCs and their mechanisms of tolerance induction with the focus on interleukin-10-modulated DCs. In addition, we will discuss the prerequisites for optimal clinical grade tolerogenic DC subsets and results of clinical trials with tolerogenic DCs in autoimmune diseases.

  14. Unique B cell differentiation profile in tolerant kidney transplant patients.

    Science.gov (United States)

    Chesneau, M; Pallier, A; Braza, F; Lacombe, G; Le Gallou, S; Baron, D; Giral, M; Danger, R; Guerif, P; Aubert-Wastiaux, H; Néel, A; Michel, L; Laplaud, D-A; Degauque, N; Soulillou, J-P; Tarte, K; Brouard, S

    2014-01-01

    Operationally tolerant patients (TOL) display a higher number of blood B cells and transcriptional B cell signature. As they rarely develop an allo-immune response, they could display an abnormal B cell differentiation. We used an in vitro culture system to explore T-dependent differentiation of B cells into plasma cells. B cell phenotype, apoptosis, proliferation, cytokine, immunoglobulin production and markers of differentiation were followed in blood of these patients. Tolerant recipients show a higher frequency of CD20(+) CD24(hi) CD38(hi) transitional and CD20(+) CD38(lo) CD24(lo) naïve B cells compared to patients with stable graft function, correlating with a decreased frequency of CD20(-) CD38(+) CD138(+) differentiated plasma cells, suggestive of abnormal B cell differentiation. B cells from TOL proliferate normally but produce more IL-10. In addition, B cells from tolerant recipients exhibit a defective expression of factors of the end step of differentiation into plasma cells and show a higher propensity for cell death apoptosis compared to patients with stable graft function. This in vitro profile is consistent with down-regulation of B cell differentiation genes and anti-apoptotic B cell genes in these patients in vivo. These data suggest that a balance between B cells producing IL-10 and a deficiency in plasma cells may encourage an environment favorable to the tolerance maintenance. © Copyright 2013 The American Society of Transplantation and the American Society of Transplant Surgeons.

  15. Homeostatic NF-κB Signaling in Steady-State Migratory Dendritic Cells Regulates Immune Homeostasis and Tolerance.

    Science.gov (United States)

    Baratin, Myriam; Foray, Chloe; Demaria, Olivier; Habbeddine, Mohamed; Pollet, Emeline; Maurizio, Julien; Verthuy, Christophe; Davanture, Suzel; Azukizawa, Hiroaki; Flores-Langarica, Adriana; Dalod, Marc; Lawrence, Toby

    2015-04-21

    Migratory non-lymphoid tissue dendritic cells (NLT-DCs) transport antigens to lymph nodes (LNs) and are required for protective immune responses in the context of inflammation and to promote tolerance to self-antigens in steady-state. However, the molecular mechanisms that elicit steady-state NLT-DC maturation and migration are unknown. By comparing the transcriptome of NLT-DCs in the skin with their migratory counterparts in draining LNs, we have identified a novel NF-κB-regulated gene network specific to migratory DCs. We show that targeted deletion of IKKβ in DCs, a major activator of NF-κB, prevents NLT-DC accumulation in LNs and compromises regulatory T cell conversion in vivo. This was associated with impaired tolerance and autoimmunity. NF-κB is generally considered the prototypical pro-inflammatory transcription factor, but this study describes a role for NF-κB signaling in DCs for immune homeostasis and tolerance that could have implications in autoimmune diseases and immunity. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Halophytes: Potential Resources for Salt Stress Tolerance Genes and Promoters

    Directory of Open Access Journals (Sweden)

    Avinash Mishra

    2017-05-01

    Full Text Available Halophytes have demonstrated their capability to thrive under extremely saline conditions and thus considered as one of the best germplasm for saline agriculture. Salinity is a worldwide problem, and the salt-affected areas are increasing day-by-day because of scanty rainfall, poor irrigation system, salt ingression, water contamination, and other environmental factors. The salinity stress tolerance mechanism is a very complex phenomenon, and some pathways are coordinately linked for imparting salinity tolerance. Though a number of salt responsive genes have been reported from the halophytes, there is always a quest for promising stress-responsive genes that can modulate plant physiology according to the salt stress. Halophytes such as Aeluropus, Mesembryanthemum, Suaeda, Atriplex, Thellungiella, Cakile, and Salicornia serve as a potential candidate for the salt-responsive genes and promoters. Several known genes like antiporters (NHX, SOS, HKT, VTPase, ion channels (Cl−, Ca2+, aquaporins, antioxidant encoding genes (APX, CAT, GST, BADH, SOD and some novel genes such as USP, SDR1, SRP etc. were isolated from halophytes and explored for developing stress tolerance in the crop plants (glycophytes. It is evidenced that stress triggers salt sensors that lead to the activation of stress tolerance mechanisms which involve multiple signaling proteins, up- or down-regulation of several genes, and finally the distinctive or collective effects of stress-responsive genes. In this review, halophytes are discussed as an excellent platform for salt responsive genes which can be utilized for developing salinity tolerance in crop plants through genetic engineering.

  17. Effect of aging and oral tolerance on dendritic cell function

    Directory of Open Access Journals (Sweden)

    P.U. Simioni

    2010-01-01

    Full Text Available Oral tolerance can be induced in some mouse strains by gavage or spontaneous ingestion of dietary antigens. In the present study, we determined the influence of aging and oral tolerance on the secretion of co-stimulatory molecules by dendritic cells (DC, and on the ability of DC to induce proliferation and cytokine secretion by naive T cells from BALB/c and OVA transgenic (DO11.10 mice. We observed that oral tolerance could be induced in BALB/c mice (N = 5 in each group of all ages (8, 20, 40, 60, and 80 weeks old, although a decline in specific antibody levels was observed in the sera of both tolerized and immunized mice with advancing age (40 to 80 weeks old. DC obtained from young, adult and middle-aged (8, 20, and 40 weeks old tolerized mice were less efficient (65, 17 and 20%, respectively than DC from immunized mice (P < 0.05 in inducing antigen-specific proliferation of naive T cells from both BALB/c and DO11.10 young mice, or in stimulating IFN-g, IL-4 and IL-10 production. However, TGF-β levels were significantly elevated in co-cultures carried out with DC from tolerant mice (P < 0.05. DC from both immunized and tolerized old and very old (60 and 80 weeks old mice were equally ineffective in inducing T cell proliferation and cytokine production (P < 0.05. A marked reduction in CD86+ marker expression was observed in DC isolated from both old and tolerized mice (75 and 50%, respectively. The results indicate that the aging process does not interfere with the establishment of oral tolerance in BALB/c mice, but reduces DC functions, probably due to the decline of the expression of the CD86 surface marker.

  18. Bacterial lipoprotein-induced tolerance is reversed by overexpression of IRAK-1.

    LENUS (Irish Health Repository)

    Li, Chong Hui

    2012-03-01

    Tolerance to bacterial cell wall components including bacterial lipoprotein (BLP) represents an essential regulatory mechanism during bacterial infection. Reduced Toll-like receptor 2 (TLR2) and IL-1 receptor-associated kinase 1 (IRAK-1) expression is a characteristic of the downregulated TLR signaling pathway observed in BLP-tolerised cells. In this study, we attempted to clarify whether TLR2 and\\/or IRAK-1 are the key molecules responsible for BLP-induced tolerance. Transfection of HEK293 cells and THP-1 cells with the plasmid encoding TLR2 affected neither BLP tolerisation-induced NF-κB deactivation nor BLP tolerisation-attenuated pro-inflammatory cytokine tumor necrosis factor alpha (TNF-α) production, indicating that BLP tolerance develops despite overexpression of TLR2 in these cells. In contrast, overexpression of IRAK-1 reversed BLP-induced tolerance, as transfection of IRAK-1 expressing vector resulted in a dose-dependent NF-κB activation and TNF-α release in BLP-tolerised cells. Furthermore, BLP-tolerised cells exhibited markedly repressed NF-κB p65 phosphorylation and impaired binding of p65 to several pro-inflammatory cytokine gene promoters including TNF-α and interleukin-6 (IL-6). Overexpression of IRAK-1 restored the nuclear transactivation of p65 at both TNF-α and IL-6 promoters. These results indicate a crucial role for IRAK-1 in BLP-induced tolerance, and suggest IRAK-1 as a potential target for manipulation of the TLR-mediated inflammatory response during microbial sepsis.

  19. Transitional-2 B cells acquire regulatory function during tolerance induction and contribute to allograft survival.

    Science.gov (United States)

    Moreau, Aurélie; Blair, Paul A; Chai, Jian-Guo; Ratnasothy, Kulachelvy; Stolarczyk, Emilie; Alhabbab, Rowa; Rackham, Chloe L; Jones, Peter M; Smyth, Lesley; Elgueta, Raul; Howard, Jane K; Lechler, Robert I; Lombardi, Giovanna

    2015-03-01

    In humans, tolerance to renal transplants has been associated with alterations in B-cell gene transcription and maintenance of the numbers of circulating transitional B cells. Here, we use a mouse model of transplantation tolerance to investigate the contribution of B cells to allograft survival. We demonstrate that transfer of B cells from mice rendered tolerant to MHC class I mismatched skin grafts can prolong graft survival in a dose-dependent and antigen-specific manner to a degree similar to that afforded by graft-specific regulatory T (Treg) cells. Tolerance in this model was associated with an increase in transitional-2 (T2) B cells. Only T2 B cells from tolerized mice, not naïve T2 nor alloantigen experienced T2, were capable of prolonging skin allograft survival, and suppressing T-cell activation. Tolerized T2 B cells expressed lower levels of CD86, increased TIM-1, and demonstrated a preferential survival in vivo. Furthermore, we demonstrate a synergistic effect between tolerized B cells and graft-specific Treg cells. IL-10 production by T2 B cells did not contribute to tolerance, as shown by transfer of B cells from IL-10(-/-) mice. These results suggest that T2 B cells in tolerant patients may include a population of regulatory B cells that directly inhibit graft rejection. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Exogenous Glutathione Enhances Mercury Tolerance by Inhibiting Mercury Entry into Plant Cells

    Science.gov (United States)

    Kim, Yeon-Ok; Bae, Hyeun-Jong; Cho, Eunjin; Kang, Hunseung

    2017-01-01

    Despite the increasing understanding of the crucial roles of glutathione (GSH) in cellular defense against heavy metal stress as well as oxidative stress, little is known about the functional role of exogenous GSH in mercury (Hg) tolerance in plants. Here, we provide compelling evidence that GSH contributes to Hg tolerance in diverse plants. Exogenous GSH did not mitigate the toxicity of cadmium (Cd), copper (Cu), or zinc (Zn), whereas application of exogenous GSH significantly promoted Hg tolerance during seed germination and seedling growth of Arabidopsis thaliana, tobacco, and pepper. By contrast, addition of buthionine sulfoximine, an inhibitor of GSH biosynthesis, severely retarded seed germination and seedling growth of the plants in the presence of Hg. The effect of exogenous GSH on Hg specific tolerance was also evident in the presence of other heavy metals, such as Cd, Cu, and Zn, together with Hg. GSH treatment significantly decreased H2O2 and O2- levels and lipid peroxidation, but increased chlorophyll content in the presence of Hg. Importantly, GSH treatment resulted in significantly less accumulation of Hg in Arabidopsis plants, and thin layer chromatography and nuclear magnetic resonance analysis revealed that GSH had much stronger binding affinity to Hg than to Cd, Cu, or Zn, suggesting that tight binding of GSH to Hg impedes Hg uptake, leading to low Hg accumulation in plant cells. Collectively, the present findings reveal that GSH is a potent molecule capable of conferring Hg tolerance by inhibiting Hg accumulation in plants. PMID:28507557

  1. Exogenous Glutathione Enhances Mercury Tolerance by Inhibiting Mercury Entry into Plant Cells

    Directory of Open Access Journals (Sweden)

    Yeon-Ok Kim

    2017-05-01

    Full Text Available Despite the increasing understanding of the crucial roles of glutathione (GSH in cellular defense against heavy metal stress as well as oxidative stress, little is known about the functional role of exogenous GSH in mercury (Hg tolerance in plants. Here, we provide compelling evidence that GSH contributes to Hg tolerance in diverse plants. Exogenous GSH did not mitigate the toxicity of cadmium (Cd, copper (Cu, or zinc (Zn, whereas application of exogenous GSH significantly promoted Hg tolerance during seed germination and seedling growth of Arabidopsis thaliana, tobacco, and pepper. By contrast, addition of buthionine sulfoximine, an inhibitor of GSH biosynthesis, severely retarded seed germination and seedling growth of the plants in the presence of Hg. The effect of exogenous GSH on Hg specific tolerance was also evident in the presence of other heavy metals, such as Cd, Cu, and Zn, together with Hg. GSH treatment significantly decreased H2O2 and O2- levels and lipid peroxidation, but increased chlorophyll content in the presence of Hg. Importantly, GSH treatment resulted in significantly less accumulation of Hg in Arabidopsis plants, and thin layer chromatography and nuclear magnetic resonance analysis revealed that GSH had much stronger binding affinity to Hg than to Cd, Cu, or Zn, suggesting that tight binding of GSH to Hg impedes Hg uptake, leading to low Hg accumulation in plant cells. Collectively, the present findings reveal that GSH is a potent molecule capable of conferring Hg tolerance by inhibiting Hg accumulation in plants.

  2. Andrographolide Ameliorate Rheumatoid Arthritis by Promoting the Development of Regulatory T Cells

    Directory of Open Access Journals (Sweden)

    Muhaimin Rifa’i

    2010-10-01

    Full Text Available Andrographolide is important material present in Andrographis paniculata. This material can promote T cell to develop into regulatory T cell, CD4+CD25+. CD4+CD25+ regulatory T (Treg cells, a component of the innate immune response, which play a key role in the maintenance of self-tolerance, have become the focus of numerous studies over the last decade. These cells have the potential to be exploited to treat autoimmune disease. These cells inhibit the immune response in an Ag-nonspecific manner, interacting with other T cells. These T cell populations actively control the properties of other immune cells by suppressing their functional activity to prevent autoimmunity but also influence the immune response to allergens as well as against tumor cells and pathogens. In this experiment we showed that active compound from Andrographis paniculata namely andrographolide can induce active regulatory T cell that has an efficacy to cure rheumatoid arthritis mice model.

  3. Antigen-specific tolerance of human alpha1-antitrypsin induced by helper-dependent adenovirus.

    Science.gov (United States)

    Cerullo, V; McCormack, W; Seiler, M; Mane, V; Cela, R; Clarke, C; Rodgers, J R; Lee, B

    2007-12-01

    As efficient and less toxic virus-derived gene therapy vectors are developed, a pressing problem is to avoid immune response to the therapeutic gene product. Secreted therapeutic proteins potentially represent a special problem, as they are readily available to professional antigen-presenting cells throughout the body. Some studies suggest that immunity to serum proteins can be avoided in some mouse strains by using tissue-specific promoters. Here we show that expression of human alpha1-antitrypsin (AAT) was nonimmunogenic in the immune-responsive strain C3H/HeJ, when expressed from helper-dependent (HD) vectors using ubiquitous as well as tissue-specific promoters. Coadministration of less immunogenic HD vectors with an immunogenic first-generation vector failed to immunize, suggesting immune suppression rather than immune stealth. Indeed, mice primed with HD vectors were tolerant to immune challenge with hAAT emulsified in complete Freund's adjuvant. Such animals developed high-titer antibodies to coemulsified human serum albumin, showing that tolerance was antigen specific. AAT-specific T cell responses were depressed in tolerized animals, suggesting that tolerance affects both T and B cells. These results are consistent with models of high-dose tolerance of B cells and certain other suppressive mechanisms, and suggest that a high level of expression from HD vectors can be sufficient to induce specific immune tolerance to serum proteins.

  4. Indirect presentation in the thymus limits naive and regulatory T-cell differentiation by promoting deletion of self-reactive thymocytes.

    Science.gov (United States)

    Yap, Jin Yan; Wirasinha, Rushika C; Chan, Anna; Howard, Debbie R; Goodnow, Christopher C; Daley, Stephen R

    2018-02-07

    Acquisition of T-cell central tolerance involves distinct pathways of self-antigen presentation to thymocytes. One pathway termed indirect presentation requires a self-antigen transfer step from thymic epithelial cells (TECs) to bone marrow-derived cells before the self-antigen is presented to thymocytes. The role of indirect presentation in central tolerance is context-dependent, potentially due to variation in self-antigen expression, processing and presentation in the thymus. Here, we report experiments in mice in which TECs expressed a membrane-bound transgenic self-antigen, hen egg lysozyme (HEL), from either the insulin (insHEL) or thyroglobulin (thyroHEL) promoter. Intrathymic HEL expression was less abundant and more confined to the medulla in insHEL mice compared with thyroHEL mice. When indirect presentation was impaired by generating mice lacking MHC class II expression in bone marrow-derived antigen-presenting cells, insHEL-mediated thymocyte deletion was abolished, whereas thyroHEL-mediated deletion occurred at a later stage of thymocyte development and Foxp3 + regulatory T-cell differentiation increased. Indirect presentation increased the strength of T-cell receptor signalling that both self-antigens induced in thymocytes, as assessed by Helios expression. Hence, indirect presentation limits the differentiation of naive and regulatory T cells by promoting deletion of self-reactive thymocytes. © 2018 John Wiley & Sons Ltd.

  5. Effect of aging and oral tolerance on dendritic cell function.

    Science.gov (United States)

    Simioni, P U; Fernandes, L G R; Gabriel, D L; Tamashiro, W M S C

    2010-01-01

    Oral tolerance can be induced in some mouse strains by gavage or spontaneous ingestion of dietary antigens. In the present study, we determined the influence of aging and oral tolerance on the secretion of co-stimulatory molecules by dendritic cells (DC), and on the ability of DC to induce proliferation and cytokine secretion by naive T cells from BALB/c and OVA transgenic (DO11.10) mice. We observed that oral tolerance could be induced in BALB/c mice (N = 5 in each group) of all ages (8, 20, 40, 60, and 80 weeks old), although a decline in specific antibody levels was observed in the sera of both tolerized and immunized mice with advancing age (40 to 80 weeks old). DC obtained from young, adult and middle-aged (8, 20, and 40 weeks old) tolerized mice were less efficient (65, 17 and 20%, respectively) than DC from immunized mice (P stimulating IFN-g, IL-4 and IL-10 production. However, TGF-beta levels were significantly elevated in co-cultures carried out with DC from tolerant mice (P production (P oral tolerance in BALB/c mice, but reduces DC functions, probably due to the decline of the expression of the CD86 surface marker.

  6. Mannose receptor induces T-cell tolerance via inhibition of CD45 and up-regulation of CTLA-4.

    Science.gov (United States)

    Schuette, Verena; Embgenbroich, Maria; Ulas, Thomas; Welz, Meike; Schulte-Schrepping, Jonas; Draffehn, Astrid M; Quast, Thomas; Koch, Katharina; Nehring, Melanie; König, Jessica; Zweynert, Annegret; Harms, Frederike L; Steiner, Nancy; Limmer, Andreas; Förster, Irmgard; Berberich-Siebelt, Friederike; Knolle, Percy A; Wohlleber, Dirk; Kolanus, Waldemar; Beyer, Marc; Schultze, Joachim L; Burgdorf, Sven

    2016-09-20

    The mannose receptor (MR) is an endocytic receptor involved in serum homeostasis and antigen presentation. Here, we identify the MR as a direct regulator of CD8(+) T-cell activity. We demonstrate that MR expression on dendritic cells (DCs) impaired T-cell cytotoxicity in vitro and in vivo. This regulatory effect of the MR was mediated by a direct interaction with CD45 on the T cell, inhibiting its phosphatase activity, which resulted in up-regulation of cytotoxic T-lymphocyte-associated Protein 4 (CTLA-4) and the induction of T-cell tolerance. Inhibition of CD45 prevented expression of B-cell lymphoma 6 (Bcl-6), a transcriptional inhibitor that directly bound the CTLA-4 promoter and regulated its activity. These data demonstrate that endocytic receptors expressed on DCs contribute to the regulation of T-cell functionality.

  7. Systemic immunological tolerance to ocular antigens is mediated by TRAIL-expressing CD8+ T cells.

    Science.gov (United States)

    Griffith, Thomas S; Brincks, Erik L; Gurung, Prajwal; Kucaba, Tamara A; Ferguson, Thomas A

    2011-01-15

    Systemic immunological tolerance to Ag encountered in the eye restricts the formation of potentially damaging immune responses that would otherwise be initiated at other anatomical locations. We previously demonstrated that tolerance to Ag administered via the anterior chamber (AC) of the eye required Fas ligand-mediated apoptotic death of inflammatory cells that enter the eye in response to the antigenic challenge. Moreover, the systemic tolerance induced after AC injection of Ag was mediated by CD8(+) regulatory T cells. This study examined the mechanism by which these CD8(+) regulatory T cells mediate tolerance after AC injection of Ag. AC injection of Ag did not prime CD4(+) T cells and led to increased TRAIL expression by splenic CD8(+) T cells. Unlike wild-type mice, Trail(-/-) or Dr5(-/-) mice did not develop tolerance to Ag injected into the eye, even though responding lymphocytes underwent apoptosis in the AC of the eyes of these mice. CD8(+) T cells from Trail(-/-) mice that were first injected via the AC with Ag were unable to transfer tolerance to naive recipient wild-type mice, but CD8(+) T cells from AC-injected wild-type or Dr5(-/-) mice could transfer tolerance. Importantly, the transferred wild-type (Trail(+/+)) CD8(+) T cells were also able to decrease the number of infiltrating inflammatory cells into the eye; however, Trail(-/-) CD8(+) T cells were unable to limit the inflammatory cell ingress. Together, our data suggest that "helpless" CD8(+) regulatory T cells generated after AC injection of Ag enforce systemic tolerance in a TRAIL-dependent manner to inhibit inflammation in the eye.

  8. Intrinsic radiation tolerance of ultra-thin GaAs solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Hirst, L. C.; Yakes, M. K.; Warner, J. H.; Schmieder, K. J.; Walters, R. J.; Jenkins, P. P. [U.S. Naval Research Laboratory, 4555 Overlook Ave. SW., Washington, D.C. 20375 (United States); Bennett, M. F. [Sotera Defense Solutions, Inc., Annapolis Junction, Maryland 20701-1067 (United States)

    2016-07-18

    Radiation tolerance is a critical performance criterion of photovoltaic devices for space power applications. In this paper we demonstrate the intrinsic radiation tolerance of an ultra-thin solar cell geometry. Device characteristics of GaAs solar cells with absorber layer thicknesses 80 nm and 800 nm were compared before and after 3 MeV proton irradiation. Both cells showed a similar degradation in V{sub oc} with increasing fluence; however, the 80 nm cell showed no degradation in I{sub sc} for fluences up to 10{sup 14 }p{sup +} cm{sup −2}. For the same exposure, the I{sub sc} of the 800 nm cell had severely degraded leaving a remaining factor of 0.26.

  9. Aspects of Salt Tolerance in a NaCl-Selected Stable Cell Line of Citrus sinensis.

    Science.gov (United States)

    Ben-Hayyim, G; Kochba, J

    1983-07-01

    A NaCl-tolerant cell line which was selected from ovular callus of ;Shamouti' orange (Citrus sinensis L. Osbeck) proved to be a true cell line variant. This conclusion is based on the following observations. (a) Cells which have been removed from the selection pressure for at least four passages retain the same NaCl tolerance as do cells which are kept constantly on 0.2 molar NaCl. (b) Na(+) and Cl(-) uptake are considerably lower in salt-tolerant cells (R-10) than in salt-sensitive cells (L-5) at a given external NaCl concentration. (c) Growth of salt-tolerant cells is markedly suppressed upon replacement of NaCl by KCl, whereas the growth of salt-sensitive cells is only slightly affected. Accumulation of K(+) and Cl(-) accompanies the inhibition of growth. Experiments carried out with sodium and potassium sulfate suggest that the toxic effect is due to the accumulated Cl(-). (d) Removal of Ca(2+) from the growth medium severely inhibits the growth of salt-tolerant cells in the presence of NaCl, while it has a minor effect on growth of salt-sensitive cells in the presence of NaCl. (e) Electron micrographs show that the salt-tolerant cells have very big vacuoles when exposed to salt, while the size of the vacuoles of the salt-sensitive cells does not change.

  10. Confinement of activating receptors at the plasma membrane controls natural killer cell tolerance.

    Science.gov (United States)

    Guia, Sophie; Jaeger, Baptiste N; Piatek, Stefan; Mailfert, Sébastien; Trombik, Tomasz; Fenis, Aurore; Chevrier, Nicolas; Walzer, Thierry; Kerdiles, Yann M; Marguet, Didier; Vivier, Eric; Ugolini, Sophie

    2011-04-05

    Natural killer (NK) cell tolerance to self is partly ensured by major histocompatibility complex (MHC) class I-specific inhibitory receptors on NK cells, which dampen their reactivity when engaged. However, NK cells that do not detect self MHC class I are not autoreactive. We used dynamic fluorescence correlation spectroscopy to show that MHC class I-independent NK cell tolerance in mice was associated with the presence of hyporesponsive NK cells in which both activating and inhibitory receptors were confined in an actin meshwork at the plasma membrane. In contrast, the recognition of self MHC class I by inhibitory receptors "educated" NK cells to become fully reactive, and activating NK cell receptors became dynamically compartmentalized in membrane nanodomains. We propose that the confinement of activating receptors at the plasma membrane is pivotal to ensuring the self-tolerance of NK cells.

  11. Mast cell protease 6 is required for allograft tolerance.

    Science.gov (United States)

    de Vries, V C; Elgueta, R; Lee, D M; Noelle, R J

    2010-09-01

    It has been shown that mast cells (MC) are absolutely required for transplant acceptance. However, only a few of the numerous mediators produced by MC have been proposed as potential mechanisms for the observed immunosuppression. The role of proteases in acquired immune tolerance as such has not yet been addressed. In this study, we have shown the requirement for MC protease 6 (MCP6), an MC-specific tryptase, to establish tolerance toward an allogeneic skin graft. The substrate for MCP6 is interleukin (IL)-6, cytokine generally considered to indicate transplant rejection. Herein we have shown an inverse correlation between MCP6 and IL-6. High expression of MCP6 is accompanied by low levels of IL-6 when the allograft is accepted, whereas low expression of MCP6 in combination with high levels of IL-6 are observed in rejecting grafts. Moreover, tolerance toward an allogeneic graft cannot be induced in MCP6(-/-) mice. Rejection observed in these mice was comparable to that of MC-deficient hosts; it is T-cell mediated. These findings suggest that MCP6 actively depletes the local environment of IL-6 to maintain tolerance. 2010. Published by Elsevier Inc.

  12. 1Autoreactive pre-plasma cells break tolerance in the absence of regulation by dendritic cells and macrophages

    OpenAIRE

    Gilbert, Mileka R.; Wagner, Nikki J.; Jones, Shannon Z.; Wisz, Amanda B.; Roques, Jose R.; Krum, Kristen N.; Lee, Sang-Ryul; Nickeleit, Volker; Hulbert, Chrys; Thomas, James W.; Gauld, Stephen B.; Vilen, Barbara J.

    2012-01-01

    The ability to induce antibody responses to pathogens while maintaining the quiescence of autoreactive cells is an important aspect of immune tolerance. During activation of Toll-like receptor-4 (TLR4), dendritic cells (DCs) and macrophages (MFs) repress autoantibody production through their secretion of IL-6 and soluble CD40L (sCD40L). These soluble mediators selectively repress B cells chronically exposed to antigen, but not naïve cells, suggesting a means to maintain tolerance during TLR4 ...

  13. Diagnostic value of tolerance-related gene expression measured in the recipient alloantigen-reactive T cell fraction.

    Science.gov (United States)

    Lim, Dong-Gyun; Park, Youn-Hee; Kim, Sung-Eun; Jeong, Seong-Hee; Kim, Song-Cheol

    2013-08-01

    The efficient development of tolerance-inducing therapies and safe reduction of immunosuppression should be supported by early diagnosis and prediction of tolerance in transplantation. Using mouse models of donor-specific tolerance to allogeneic skin and islet grafts we tested whether measurement of tolerance-related gene expression in their alloantigen-reactive peripheral T cell fraction efficiently reflected the tolerance status of recipients. We found that Foxp3, Nrn1, and Klrg1 were preferentially expressed in conditions of tolerance compared with rejection or unmanipulated controls if their expression is measured in CD69(+) T cells prepared from coculture of recipient peripheral T cells and donor antigen-presenting cells. The same pattern of gene expression was observed in recipients grafted with either skin or islets, recipients of different genetic origins, and even those taking immunosuppressive drugs. These findings suggest that the expression of tolerance-related genes in the alloantigen-reactive T cell fraction could be used to detect tolerance in the clinic. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Mining Halophytes for Plant Growth-Promoting Halotolerant Bacteria to Enhance the Salinity Tolerance of Non-halophytic Crops

    Directory of Open Access Journals (Sweden)

    Hassan Etesami

    2018-02-01

    Full Text Available Salinity stress is one of the major abiotic stresses limiting crop production in arid and semi-arid regions. Interest is increasing in the application of PGPRs (plant growth promoting rhizobacteria to ameliorate stresses such as salinity stress in crop production. The identification of salt-tolerant, or halophilic, PGPRs has the potential to promote saline soil-based agriculture. Halophytes are a useful reservoir of halotolerant bacteria with plant growth-promoting capabilities. Here, we review recent studies on the use of halophilic PGPRs to stimulate plant growth and increase the tolerance of non-halophytic crops to salinity. These studies illustrate that halophilic PGPRs from the rhizosphere of halophytic species can be effective bio-inoculants for promoting the production of non-halophytic species in saline soils. These studies support the viability of bioinoculation with halophilic PGPRs as a strategy for the sustainable enhancement of non-halophytic crop growth. The potential of this strategy is discussed within the context of ensuring sustainable food production for a world with an increasing population and continuing climate change. We also explore future research needs for using halotolerant PGPRs under salinity stress.

  15. Dehydrins from wheat x Thinopyrum ponticum amphiploid increase salinity and drought tolerance under their own inducible promoters without growth retardation.

    Science.gov (United States)

    Qin, Yu-Xiang; Qin, Fangyuan

    2016-02-01

    Dehydrins confer abiotic stress tolerance in seedlings, but few dehydrins have been studied by transgenic analysis under their own promoters in relation to abiotic stress tolerance. Also the inducible promoters for transgenic engineering are limited. In this study, we isolated from wheat three salt-induced YSK2 dehydrin genes and their promoters. The cDNA sequences were 711, 785, and 932 bp in length, encoding proteins containing 133, 166 and 231 amino acids, respectively, and were named TaDHN1, TaDHN2, and TaDHN3. TaDHN2 doesn't contain introns, while the other two genes each contain one. Semi-quantitative reverse transcription PCR analysis revealed all three dehydrin genes are substantially induced by ABA and NaCl, but only TaDHN2 is induced in seedlings by PEG and by cold (4 °C). Regulatory sequences upstream of the first translation codon (775, 1615 and 889 bp) of the three dehydrin genes were also cloned. Cis-element prediction indicated the presence of ABRE and other abiotic-stress-related elements. Histochemical analysis using GUS expression demonstrated that all three promoters were induced by ABA, cold or NaCl. Ectopic over-expression of TaDHN1 or TaDHN3 in Arabidopsis under their own inducible promoters enhanced NaCl- and drought-stress tolerance without growth retardation. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  16. Pregnancy promotes tolerance to future offspring by programming selective dysfunction in long-lived maternal T cells.

    Science.gov (United States)

    Barton, Brendan M; Xu, Rong; Wherry, E John; Porrett, Paige M

    2017-04-01

    Fetal antigen available during pregnancy induces the proliferation of maternal T cells. It is unknown, however, whether these antigen-activated T cells differentiate into long-lived memory T cells that are capable of mediating rapid-recall responses to tissue antigens. To test the hypothesis that pregnancy induces an alternative fate in fetal-specific maternal T cells, we used a murine model to track longitudinally fetal-specific T cells in pregnant and postpartum animals and test the response of these cells when challenged with the same antigen during sequential pregnancy or skin transplantation. Fetal-specific CD8 + T cells were robustly primed during pregnancy but failed to acquire robust effector functions. These primed cells persisted long term in postpartum animals, frequently maintained a programmed death 1 (PD-1) + phenotype, and failed to expand or produce cytokines robustly in response to second pregnancy or skin transplantation. However, whereas there was no impact on second pregnancy as a result of the persistence of fetal-primed memory CD8 + T cells in the mother, skin grafts bearing the same antigen were rejected more rapidly. Altogether, our data suggest that fetal antigen exposure during pregnancy induces the differentiation of long-lived maternal CD8 + T cells with context-dependent, selective effector dysfunction. This programmed effector dysfunction provides temporal and systemic restraint of maternal anti-fetal alloreactivity to promote reproductive fitness efficiently, while preserving potentially protective effector T cell responses. © Society for Leukocyte Biology.

  17. Aspects of Salt Tolerance in a NaCl-Selected Stable Cell Line of Citrus sinensis1

    Science.gov (United States)

    Ben-Hayyim, Gozal; Kochba, Joshua

    1983-01-01

    A NaCl-tolerant cell line which was selected from ovular callus of `Shamouti' orange (Citrus sinensis L. Osbeck) proved to be a true cell line variant. This conclusion is based on the following observations. (a) Cells which have been removed from the selection pressure for at least four passages retain the same NaCl tolerance as do cells which are kept constantly on 0.2 molar NaCl. (b) Na+ and Cl− uptake are considerably lower in salt-tolerant cells (R-10) than in salt-sensitive cells (L-5) at a given external NaCl concentration. (c) Growth of salt-tolerant cells is markedly suppressed upon replacement of NaCl by KCl, whereas the growth of salt-sensitive cells is only slightly affected. Accumulation of K+ and Cl− accompanies the inhibition of growth. Experiments carried out with sodium and potassium sulfate suggest that the toxic effect is due to the accumulated Cl−. (d) Removal of Ca2+ from the growth medium severely inhibits the growth of salt-tolerant cells in the presence of NaCl, while it has a minor effect on growth of salt-sensitive cells in the presence of NaCl. (e) Electron micrographs show that the salt-tolerant cells have very big vacuoles when exposed to salt, while the size of the vacuoles of the salt-sensitive cells does not change. Images Fig. 3 PMID:16663067

  18. Targeting CD8+ T-cell tolerance for cancer immunotherapy.

    Science.gov (United States)

    Jackson, Stephanie R; Yuan, Jinyun; Teague, Ryan M

    2014-01-01

    In the final issue of Science in 2013, the American Association of Science recognized progress in the field of cancer immunotherapy as the 'Breakthrough of the Year.' The achievements were actually twofold, owing to the early success of genetically engineered chimeric antigen receptors (CAR) and to the mounting clinical triumphs achieved with checkpoint blockade antibodies. While fundamentally very different, the common thread of these independent strategies is the ability to prevent or overcome mechanisms of CD8(+) T-cell tolerance for improved tumor immunity. Here we discuss how circumventing T-cell tolerance has provided experimental insights that have guided the field of clinical cancer immunotherapy to a place where real breakthroughs can finally be claimed.

  19. CD 4 + CD 25 + T cells maintain homeostasis by promoting TER - 119 cell development and inhibiting T cell activation

    Directory of Open Access Journals (Sweden)

    Muhaimin Rifa’i

    2014-05-01

    Full Text Available CD4+ CD25+ regulatory T cells involved in the regulation of self- tolerance and normality of homeostasis. CD122 deficient mice are model animals that have an abnormal immune system characteristically have a high number of activated T cells and TER-119 cell decreased. Here we showed evidence that the transfer of CD4+ CD25+ regulatory T cells derived from normal mice to CD122- defficient neonates prevent the development of activated memory T cells and elicit TER-119 differentiation. Bone marrow reconstitution derived from CD122-/- mice to normal mice resulting tolerance to individual that genetically different. Importantly, CD4+ CD25+ regulatory T cells derived from normal mice can replace CD4+ CD25+ cells derived from CD122-/- mice. The results of this experiment suggest that regulatory T cells from normal mice exert a critical role in maintaining peripheral tolerance and controlling hematopoietic disorder.

  20. High Fat Diet Inhibits Dendritic Cell and T Cell Response to Allergens but Does Not Impair Inhalational Respiratory Tolerance.

    Directory of Open Access Journals (Sweden)

    Angela Pizzolla

    Full Text Available The incidence of obesity has risen to epidemic proportions in recent decades, most commonly attributed to an increasingly sedentary lifestyle, and a 'western' diet high in fat and low in fibre. Although non-allergic asthma is a well-established co-morbidity of obesity, the influence of obesity on allergic asthma is still under debate. Allergic asthma is thought to result from impaired tolerance to airborne antigens, so-called respiratory tolerance. We sought to investigate whether a diet high in fats affects the development of respiratory tolerance. Mice fed a high fat diet (HFD for 8 weeks showed weight gain, metabolic disease, and alteration in gut microbiota, metabolites and glucose metabolism compared to age-matched mice fed normal chow diet (ND. Respiratory tolerance was induced by repeated intranasal (i.n. administration of ovalbumin (OVA, prior to induction of allergic airway inflammation (AAI by sensitization with OVA in alum i.p. and subsequent i.n. OVA challenge. Surprisingly, respiratory tolerance was induced equally well in HFD and ND mice, as evidenced by decreased lung eosinophilia and serum OVA-specific IgE production. However, in a pilot study, HFD mice showed a tendency for impaired activation of airway dendritic cells and regulatory T cells compared with ND mice after induction of respiratory tolerance. Moreover, the capacity of lymph node cells to produce IL-5 and IL-13 after AAI was drastically diminished in HFD mice compared to ND mice. These results indicate that HFD does not affect the inflammatory or B cell response to an allergen, but inhibits priming of Th2 cells and possibly dendritic cell and regulatory T cell activation.

  1. RSK2-induced stress tolerance enhances cell survival signals mediated by inhibition of GSK3β activity

    International Nuclear Information System (INIS)

    Lee, Cheol-Jung; Lee, Mee-Hyun; Lee, Ji-Young; Song, Ji Hong; Lee, Hye Suk; Cho, Yong-Yeon

    2013-01-01

    Highlights: •We demonstrated a novel function of RSK2 in stress tolerance. •RSK2 deficiency enhanced apoptosis by calcium stress. •RSK2-mediated GSK3β phosphorylation at serine 9 increased calcium-induced stress tolerance. •Calcium stress-induced apoptosis inhibited by adding back of RSK2 into RSK2 −/− MEFs. -- Abstract: Our previous studies demonstrated that RSK2 plays a key role in cell proliferation and transformation induced by tumor promoters such as epidermal growth factor (EGF) in mouse and human skin cells. However, no direct evidence has been found regarding the relationship of RSK2 and cell survival. In this study, we found that RSK2 interacted and phosphorylated GSK3β at Ser9. Notably, GSK3β phosphorylation at Ser9 was suppressed in RSK2 −/− MEFs compared with RSK2 +/+ MEFs by stimulation of EGF and calcium ionophore A23187, a cellular calcium stressor. In proliferation, we found that RSK2 deficiency suppressed cell proliferation compared with RSK2 +/+ MEFs. In contrast, GSK3β −/− MEFs induced the cell proliferation compared with GSK3β +/+ MEFs. Importantly, RSK2 −/− MEFs were induced severe cellular morphology change by A23187 and enhanced G1/G0 and sub-G1 accumulation of the cell cycle phase compared with RSK2 +/+ MEFs. The sub-G1 induction in RSK2 −/− MEFs by A23187 was correlated with increase of cytochrome c release, caspase-3 cleavage and apoptotic DNA fragmentation compared with RSK2 +/+ MEFs. Notably, return back of RSK2 into RSK2 −/− MEFs restored A23187-induced morphological change, and decreased apoptosis, apoptotic DNA fragmentation and caspase-3 induction compared with RSK2 −/− /mock MEFs. Taken together, our results demonstrated that RSK2 plays an important role in stress-tolerance and cell survival, resulting in cell proliferation and cancer development

  2. The nature of tolerance in adult recipient mice made tolerant of alloantigens with supralethal irradiation followed by syngeneic bone marrow cell transplantation plus injection of F1 spleen cells

    International Nuclear Information System (INIS)

    Tomita, Y.; Himeno, K.; Mayumi, H.; Tokuda, N.; Nomoto, K.

    1989-01-01

    The length of time after syngeneic bone marrow reconstitution when tolerance to alloantigens can be induced in adult mice during T cell differentiation from bone marrow cells was studied by exposing those T cells to (recipient x donor)F1 spleen cells. Supralethally irradiated C3H/He Slc(C3H; H-2k) mice were reconstituted with 1 x 10(7) syngeneic T cell-depleted bone marrow cells and then injected intravenously with 5 x 10(7) (C3H x C57BL/6[B6])F1 (B6C3F1; H-2bxk) or (C3H x AKR/J[AKR])F1 (AKC3F1; H-2kxk) spleen cells at various intervals. In the fully allogeneic combination of B6C3F1----C3H, EL-4 tumor originating from B6 was accepted, and survival of grafted B6 skin was significantly prolonged in the tolerant C3H mice treated with irradiation on day -1 followed by injection of syngeneic bone marrow cells on day 0 plus B6C3F1 spleen cells on days 0, 5, or 10, in a tolerogen-specific manner. In the multiminor histocompatibility antigen-disparate combination of AKC3F1----C3H, AKR skin grafts were permanently accepted in the tolerant C3H mice treated with AKC3F1 spleen cells on days 0, 5, 10, or 15. Immunological parameters, including cytotoxic T lymphocyte activity and delayed foot-pad reaction (DFR), were almost completely suppressed in C3H mice made tolerant of B6 or AKR antigens. A chimeric assay using a direct immunofluorescence method revealed that the tolerant C3H mice given B6C3F1 spleen cells on day 0 were mixed-chimeric for at least 8 weeks after syngeneic bone marrow reconstitution, but not definitely chimeric thereafter. The C3H mice given AKC3F1 spleen cells on day 0 were chimeric even 43 weeks after syngeneic bone marrow reconstitution, but the C3H mice given AKC3F1 spleen cells on day 15 showed temporal chimerism that disappeared within 43 weeks. The untolerant mice were never detectably chimeric

  3. Isoamyl alcohol odor promotes longevity and stress tolerance via DAF-16 in Caenorhabditis elegans.

    Science.gov (United States)

    Kurino, Chiho; Furuhashi, Tsubasa; Sudoh, Kaori; Sakamoto, Kazuichi

    2017-04-01

    The possibility that odor plays a role in lifespan regulation through effects on the nervous system is indicated by research on Caenorhabditis elegans. In fact, ablation of AWA and AWC, which are suggested as olfactory neurons, has been shown to extend lifespan via DAF-16, a homolog of FoxO. However, the effects of odor stimuli on the lifespan still remain unclear. Thus, we here aimed to clarify the effect of attractive and repulsive odors on longevity and stress tolerance in C. elegans and to analyze the pathways thereof. We used isoamyl alcohol as an attractive odor, and acetic acid as a repellent component, as identified by chemotaxis assay. We found that isoamyl alcohol stimulus promoted longevity in a DAF-16-dependent manner. On the other hand, acetic acid stimulus promoted thermotolerance through mechanisms independent of DAF-16. Above all, our results indicate that odor stimuli affect the lifespan and stress tolerance of C. elegans, with attractive and repulsive odors exerting their effects through different mechanisms, and that longevity is induced by both activation and inactivation of olfactory neurons. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Bone marrow pre-B cells and the clonal anergy theory of immunologic tolerance.

    Science.gov (United States)

    Nossal, G J

    1987-03-01

    This review begins with a summary of a decade's research from the author's own laboratory which documents the fact that B lymphocytes can receive and store negative, down-regulatory signals from an encounter with antigen, and that the sensitivity to such negative signalling depends critically on maturational status, the most immature B cells being the most susceptible. The review then examines the relationship between these experimentally-induced models of immunologic tolerance, with the pre-B to B cell transition as the critical stage for examination, and the real-life phenomenon of self-tolerance. It makes the point that no repertoire-purging mechanism to ensure self-tolerance can afford to be too effective, for fear of purging too many useful cells, given the number and variability of self-antigens. The review then examines certain dilemmas posed by recent findings in cellular and molecular immunology. These include: 1) the preferential use of particular VH gene families by B cells at different stages of the differentiation process; 2) the apparent frequency of B lymphocytes with the potential for antiself-reactivity in the B cell repertoire; and 3) the existence of a new type of B cell, the Ly-1-positive B cell, with peculiar characteristics. These findings are considered within the particular contexts of pre-B-to-B cell transition and tolerance induction through clonal anergy mechanisms.

  5. ES-cell derived hematopoietic cells induce transplantation tolerance.

    Directory of Open Access Journals (Sweden)

    Sabrina Bonde

    Full Text Available BACKGROUND: Bone marrow cells induce stable mixed chimerism under appropriate conditioning of the host, mediating the induction of transplantation tolerance. However, their strong immunogenicity precludes routine use in clinical transplantation due to the need for harsh preconditioning and the requirement for toxic immunosuppression to prevent rejection and graft-versus-host disease. Alternatively, embryonic stem (ES cells have emerged as a potential source of less immunogenic hematopoietic progenitor cells (HPCs. Up till now, however, it has been difficult to generate stable hematopoietic cells from ES cells. METHODOLOGY/PRINCIPAL FINDINGS: Here, we derived CD45(+ HPCs from HOXB4-transduced ES cells and showed that they poorly express MHC antigens. This property allowed their long-term engraftment in sublethally irradiated recipients across MHC barriers without the need for immunosuppressive agents. Although donor cells declined in peripheral blood over 2 months, low level chimerism was maintained in the bone marrow of these mice over 100 days. More importantly, chimeric animals were protected from rejection of donor-type cardiac allografts. CONCLUSIONS: Our data show, for the first time, the efficacy of ES-derived CD45(+ HPCs to engraft in allogenic recipients without the use of immunosuppressive agents, there by protecting cardiac allografts from rejection.

  6. Alveolar epithelial type II cells induce T cell tolerance to specific antigen

    DEFF Research Database (Denmark)

    Lo, Bernice; Hansen, Søren; Evans, Kathy

    2008-01-01

    The lungs face the immunologic challenge of rapidly eliminating inhaled pathogens while maintaining tolerance to innocuous Ags. A break in this immune homeostasis may result in pulmonary inflammatory diseases, such as allergies or asthma. The observation that alveolar epithelial type II cells (Type...... II) constitutively express the class II MHC led us to hypothesize that Type II cells play a role in the adaptive immune response. Because Type II cells do not express detectable levels of the costimulatory molecules CD80 and CD86, we propose that Type II cells suppress activation of naive T cells...

  7. Induction of transplantation tolerance to fully mismatched cardiac allografts by T cell mediated delivery of alloantigen

    Science.gov (United States)

    Tian, Chaorui; Yuan, Xueli; Jindra, Peter T.; Bagley, Jessamyn; Sayegh, Mohamed H.; Iacomini, John

    2010-01-01

    Induction of transplantation tolerance has the potential to allow for allograft acceptance without the need for life-long immunosuppression. Here we describe a novel approach that uses delivery of alloantigen by mature T cells to induce tolerance to fully allogeneic cardiac grafts. Adoptive transfer of mature alloantigen-expressing T cells into myeloablatively conditioned mice results in long-term acceptance of fully allogeneic heart transplants without evidence of chronic rejection. Since myeloablative conditioning is clinically undesirable we further demonstrated that adoptive transfer of mature alloantigen-expressing T cells alone into mice receiving non-myeloablative conditioning resulted in long-term acceptance of fully allogeneic heart allografts with minimal evidence of chronic rejection. Mechanistically, tolerance induction involved both deletion of donor-reactive host T cells and the development of regulatory T cells. Thus, delivery of alloantigen by mature T cells induces tolerance to fully allogeneic organ allografts in non-myeloablatively conditioned recipients, representing a novel approach for tolerance induction in transplantation. PMID:20452826

  8. A late embryogenesis abundant protein HVA1 regulated by an inducible promoter enhances root growth and abiotic stress tolerance in rice without yield penalty.

    Science.gov (United States)

    Chen, Yi-Shih; Lo, Shuen-Fang; Sun, Peng-Kai; Lu, Chung-An; Ho, Tuan-Hua D; Yu, Su-May

    2015-01-01

    Regulation of root architecture is essential for maintaining plant growth under adverse environment. A synthetic abscisic acid (ABA)/stress-inducible promoter was designed to control the expression of a late embryogenesis abundant protein (HVA1) in transgenic rice. The background of HVA1 is low but highly inducible by ABA, salt, dehydration and cold. HVA1 was highly accumulated in root apical meristem (RAM) and lateral root primordia (LRP) after ABA/stress treatments, leading to enhanced root system expansion. Water-use efficiency (WUE) and biomass also increased in transgenic rice, likely due to the maintenance of normal cell functions and metabolic activities conferred by HVA1 which is capable of stabilizing proteins, under osmotic stress. HVA1 promotes lateral root (LR) initiation, elongation and emergence and primary root (PR) elongation via an auxin-dependent process, particularly by intensifying asymmetrical accumulation of auxin in LRP founder cells and RAM, even under ABA/stress-suppressive conditions. We demonstrate a successful application of an inducible promoter in regulating the spatial and temporal expression of HVA1 for improving root architecture and multiple stress tolerance without yield penalty. © 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  9. Rapamycin combined with anti-CD45RB mAb and IL-10 or with G-CSF induces tolerance in a stringent mouse model of islet transplantation.

    Directory of Open Access Journals (Sweden)

    Nicola Gagliani

    Full Text Available BACKGROUND: A large pool of preexisting alloreactive effector T cells can cause allogeneic graft rejection following transplantation. However, it is possible to induce transplant tolerance by altering the balance between effector and regulatory T (Treg cells. Among the various Treg-cell types, Foxp3(+Treg and IL-10-producing T regulatory type 1 (Tr1 cells have frequently been associated with tolerance following transplantation in both mice and humans. Previously, we demonstrated that rapamycin+IL-10 promotes Tr1-cell-associated tolerance in Balb/c mice transplanted with C57BL/6 pancreatic islets. However, this same treatment was unsuccessful in C57BL/6 mice transplanted with Balb/c islets (classified as a stringent transplant model. We accordingly designed a protocol that would be effective in the latter transplant model by simultaneously depleting effector T cells and fostering production of Treg cells. We additionally developed and tested a clinically translatable protocol that used no depleting agent. METHODOLOGY/PRINCIPAL FINDINGS: Diabetic C57BL/6 mice were transplanted with Balb/c pancreatic islets. Recipient mice transiently treated with anti-CD45RB mAb+rapamycin+IL-10 developed antigen-specific tolerance. During treatment, Foxp3(+Treg cells were momentarily enriched in the blood, followed by accumulation in the graft and draining lymph node, whereas CD4(+IL-10(+IL-4(- T (i.e., Tr1 cells localized in the spleen. In long-term tolerant mice, only CD4(+IL-10(+IL-4(- T cells remained enriched in the spleen and IL-10 was key in the maintenance of tolerance. Alternatively, recipient mice were treated with two compounds routinely used in the clinic (namely, rapamycin and G-CSF; this drug combination promoted tolerance associated with CD4(+IL-10(+IL-4(- T cells. CONCLUSIONS/SIGNIFICANCE: The anti-CD45RB mAb+rapamycin+IL-10 combined protocol promotes a state of tolerance that is IL-10 dependent. Moreover, the combination of rapamycin+G-CSF induces

  10. Rituximab does not reset defective early B cell tolerance checkpoints

    Science.gov (United States)

    Chamberlain, Nicolas; Massad, Christopher; Oe, Tyler; Cantaert, Tineke; Herold, Kevan C.; Meffre, Eric

    2015-01-01

    Type 1 diabetes (T1D) patients show abnormalities in early B cell tolerance checkpoints, resulting in the accumulation of large numbers of autoreactive B cells in their blood. Treatment with rituximab, an anti-CD20 mAb that depletes B cells, has been shown to preserve β cell function in T1D patients and improve other autoimmune diseases, including rheumatoid arthritis and multiple sclerosis. However, it remains largely unknown how anti–B cell therapy thwarts autoimmunity in these pathologies. Here, we analyzed the reactivity of Abs expressed by single, mature naive B cells from 4 patients with T1D before and 52 weeks after treatment to determine whether rituximab resets early B cell tolerance checkpoints. We found that anti–B cell therapy did not alter the frequencies of autoreactive and polyreactive B cells, which remained elevated in the blood of all patients after rituximab treatment. Moreover, the limited proliferative history of autoreactive B cells after treatment revealed that these clones were newly generated B cells and not self-reactive B cells that had escaped depletion and repopulated the periphery through homeostatic expansion. We conclude that anti–B cell therapy may provide a temporary dampening of autoimmune processes through B cell depletion. However, repletion with autoreactive B cells may explain the relapse that occurs in many autoimmune patients after anti–B cell therapy. PMID:26642366

  11. Engineering tolerance to industrially relevant stress factors in yeast cell factories.

    Science.gov (United States)

    Deparis, Quinten; Claes, Arne; Foulquié-Moreno, Maria R; Thevelein, Johan M

    2017-06-01

    The main focus in development of yeast cell factories has generally been on establishing optimal activity of heterologous pathways and further metabolic engineering of the host strain to maximize product yield and titer. Adequate stress tolerance of the host strain has turned out to be another major challenge for obtaining economically viable performance in industrial production. Although general robustness is a universal requirement for industrial microorganisms, production of novel compounds using artificial metabolic pathways presents additional challenges. Many of the bio-based compounds desirable for production by cell factories are highly toxic to the host cells in the titers required for economic viability. Artificial metabolic pathways also turn out to be much more sensitive to stress factors than endogenous pathways, likely because regulation of the latter has been optimized in evolution in myriads of environmental conditions. We discuss different environmental and metabolic stress factors with high relevance for industrial utilization of yeast cell factories and the experimental approaches used to engineer higher stress tolerance. Improving stress tolerance in a predictable manner in yeast cell factories should facilitate their widespread utilization in the bio-based economy and extend the range of products successfully produced in large scale in a sustainable and economically profitable way. © FEMS 2017.

  12. Engineering tolerance to industrially relevant stress factors in yeast cell factories

    Science.gov (United States)

    Deparis, Quinten; Claes, Arne; Foulquié-Moreno, Maria R.

    2017-01-01

    Abstract The main focus in development of yeast cell factories has generally been on establishing optimal activity of heterologous pathways and further metabolic engineering of the host strain to maximize product yield and titer. Adequate stress tolerance of the host strain has turned out to be another major challenge for obtaining economically viable performance in industrial production. Although general robustness is a universal requirement for industrial microorganisms, production of novel compounds using artificial metabolic pathways presents additional challenges. Many of the bio-based compounds desirable for production by cell factories are highly toxic to the host cells in the titers required for economic viability. Artificial metabolic pathways also turn out to be much more sensitive to stress factors than endogenous pathways, likely because regulation of the latter has been optimized in evolution in myriads of environmental conditions. We discuss different environmental and metabolic stress factors with high relevance for industrial utilization of yeast cell factories and the experimental approaches used to engineer higher stress tolerance. Improving stress tolerance in a predictable manner in yeast cell factories should facilitate their widespread utilization in the bio-based economy and extend the range of products successfully produced in large scale in a sustainable and economically profitable way. PMID:28586408

  13. Promoting sustainable potato agriculture in the Andean region by supplemental calcium nutrition and breeding for frost tolerance

    Science.gov (United States)

    Collaborative research in Peru sought to promote sustainable potato production and, mitigate adverse impacts of climate change through two approaches: first calcium amendments to increase crop yield and, second to enhance frost tolerance in native potatoes. All the multi-year, multi-location experim...

  14. Modulation of Tumor Tolerance in Primary Central Nervous System Malignancies

    Directory of Open Access Journals (Sweden)

    Theodore S. Johnson

    2012-01-01

    Full Text Available Central nervous system tumors take advantage of the unique immunology of the CNS and develop exquisitely complex stromal networks that promote growth despite the presence of antigen-presenting cells and tumor-infiltrating lymphocytes. It is precisely this immunological paradox that is essential to the survival of the tumor. We review the evidence for functional CNS immune privilege and the impact it has on tumor tolerance. In this paper, we place an emphasis on the role of tumor-infiltrating myeloid cells in maintaining stromal and vascular quiescence, and we underscore the importance of indoleamine 2,3-dioxygenase activity as a myeloid-driven tumor tolerance mechanism. Much remains to be discovered regarding the tolerogenic mechanisms by which CNS tumors avoid immune clearance. Thus, it is an open question whether tumor tolerance in the brain is fundamentally different from that of peripheral sites of tumorigenesis or whether it simply stands as a particularly strong example of such tolerance.

  15. Endogenous salicylic acid is required for promoting cadmium tolerance of Arabidopsis by modulating glutathione metabolisms

    International Nuclear Information System (INIS)

    Guo, Bin; Liu, Chen; Li, Hua; Yi, Keke; Ding, Nengfei; Li, Ningyu; Lin, Yicheng; Fu, Qinglin

    2016-01-01

    Highlights: • The role of endogenous SA in mediating Cd tolerance was explored using sid2 mutants. • Cd stress induces SA accumulation in a SID2 dependent way. • Depletion of SA causes negative effects on Cd tolerance. • Endogenous SA is required for promoting Cd tolerance by modulating GSH metabolism. • Possible mode of SA signaling through GR/GSH pathway under Cd toxicity was discussed. - Abstract: A few studies with NahG transgenic lines of Arabidopsis show that depletion of SA enhances cadmium (Cd) tolerance. However, it remains some uncertainties that the defence signaling may be a result of catechol accumulation in NahG transgenic lines but not SA deficiency. Here, we conducted a set of hydroponic assays with another SA-deficient mutant sid2 to examine the endogenous roles of SA in Cd tolerance, especially focusing on the glutathione (GSH) cycling. Our results showed that reduced SA resulted in negative effects on Cd tolerance, including decreased Fe uptake and chlorophyll concentration, aggravation of oxidative damage and growth inhibition. Cd exposure significantly increased SA concentration in wild-type leaves, but did not affect it in sid2 mutants. Depletion of SA did not disturb the Cd uptake in either roots or shoots. The reduced Cd tolerance in sid2 mutants is due to the lowered GSH status, which is associated with the decreased expression of serine acetyltransferase along with a decline in contents of non-protein thiols, phytochelatins, and the lowered transcription and activities of glutathione reductase1 (GR1) which reduced GSH regeneration. Finally, the possible mode of SA signaling through the GR/GSH pathway during Cd exposure is discussed.

  16. Endogenous salicylic acid is required for promoting cadmium tolerance of Arabidopsis by modulating glutathione metabolisms

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Bin, E-mail: ndgb@163.com [Institute of Environment, Resource, Soil and Fertilizer, Zhejiang Academy of Agricultural Sciences, Geological Research Center For Agricultural Applications, China Geological Survey, Hangzhou (China); Liu, Chen; Li, Hua [Institute of Environment, Resource, Soil and Fertilizer, Zhejiang Academy of Agricultural Sciences, Geological Research Center For Agricultural Applications, China Geological Survey, Hangzhou (China); Yi, Keke [Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou (China); Ding, Nengfei; Li, Ningyu; Lin, Yicheng [Institute of Environment, Resource, Soil and Fertilizer, Zhejiang Academy of Agricultural Sciences, Geological Research Center For Agricultural Applications, China Geological Survey, Hangzhou (China); Fu, Qinglin, E-mail: fuql161@yahoo.com.cn [Institute of Environment, Resource, Soil and Fertilizer, Zhejiang Academy of Agricultural Sciences, Geological Research Center For Agricultural Applications, China Geological Survey, Hangzhou (China)

    2016-10-05

    Highlights: • The role of endogenous SA in mediating Cd tolerance was explored using sid2 mutants. • Cd stress induces SA accumulation in a SID2 dependent way. • Depletion of SA causes negative effects on Cd tolerance. • Endogenous SA is required for promoting Cd tolerance by modulating GSH metabolism. • Possible mode of SA signaling through GR/GSH pathway under Cd toxicity was discussed. - Abstract: A few studies with NahG transgenic lines of Arabidopsis show that depletion of SA enhances cadmium (Cd) tolerance. However, it remains some uncertainties that the defence signaling may be a result of catechol accumulation in NahG transgenic lines but not SA deficiency. Here, we conducted a set of hydroponic assays with another SA-deficient mutant sid2 to examine the endogenous roles of SA in Cd tolerance, especially focusing on the glutathione (GSH) cycling. Our results showed that reduced SA resulted in negative effects on Cd tolerance, including decreased Fe uptake and chlorophyll concentration, aggravation of oxidative damage and growth inhibition. Cd exposure significantly increased SA concentration in wild-type leaves, but did not affect it in sid2 mutants. Depletion of SA did not disturb the Cd uptake in either roots or shoots. The reduced Cd tolerance in sid2 mutants is due to the lowered GSH status, which is associated with the decreased expression of serine acetyltransferase along with a decline in contents of non-protein thiols, phytochelatins, and the lowered transcription and activities of glutathione reductase1 (GR1) which reduced GSH regeneration. Finally, the possible mode of SA signaling through the GR/GSH pathway during Cd exposure is discussed.

  17. Induction of transplantation tolerance by combining non-myeloablative conditioning with delivery of alloantigen by T cells

    Science.gov (United States)

    Tian, Chaorui; Yuan, Xueli; Bagley, Jessamyn; Blazar, Bruce R.; Sayegh, Mohamed H.; Iacomini, John

    2008-01-01

    The observation that bone marrow derived hematopoietic cells are potent inducers of tolerance has generated interest in trying to establish transplantation tolerance by inducing a state of hematopoietic chimerism through allogeneic bone marrow transplantation. However, this approach is associated with serious complications that limit its utility for tolerance induction. Here we describe the development of a novel approach that allows for tolerance induction without the need for an allogeneic bone marrow transplant by combining non-myeloablative host conditioning with delivery of donor alloantigen by adoptively transferred T cells. CBA/Ca mice were administered 2.5Gy whole body irradiation (WBI). The following day the mice received Kb disparate T cells from MHC class I transgenic CBK donor mice, as well as rapamycin on days 0–13 and anti-CD40L monoclonal antibody on days 0–5, 8,11 and 14 relative to T cell transfer. Mice treated using this approach were rendered specifically tolerant to CBK skin allografts through a mechanism involving central and peripheral deletion of alloreactive T cells. These data suggest robust tolerance can be established without the need for bone marrow transplantation using clinically relevant non-myeloablative conditioning combined with antigen delivery by T cells. PMID:18280792

  18. A novel cell growth-promoting factor identified in a B cell leukemia cell line, BALL-1

    International Nuclear Information System (INIS)

    Dao, T.; Holan, V.; Minowada, J.

    1993-01-01

    A novel leukemia cell growth-promoting activity has been identified in the culture supernatant from a human B cell leukemia cell line, BALL-1. The supernatant from unstimulated cultures of the BALL-1 cells significantly promoted the growth of 16 out of 24 leukemia/lymphoma cell lines of different lineages (T, B and non-lymphoid) in a minimal concentration of fetal bovine serum (FBS), and 5 out of 12 cases of fresh leukemia cells in FBS-free medium. The growth-promoting sieve filtration and dialysis. The MW of the factor was less than 10 kDa. The growth-promoting activity was heat and acid stable and resistant to trypsin treatment. The factor isolated from the BALL-1 supernatant was distinct from known polypeptide growth factors with MW below 10 kDa, such as epidermal growth factor, transforming growth factor α, insulin-like growth factor I (IGF-I), IGF-II and insulin, as determine by specific antibodies and by cell-growth-promoting tests. The factor is the BALL-1 supernatant did not promote the proliferation of normal human fresh peripheral blood lymphocytes or mouse fibroblast cell line, BALB/C 3T3. In addition to the BALL-1 supernatant, a similar growth-promoting activity was found in the culture supernatant from 13 of 17 leukemia/lymphoma cell lines tested. The activity in these culture supernatant promoted the growth of leukemia/lymphoma cell lines in autocrine and/or paracrine fashions. These observations suggest that the low MW cell growth-promoting activity found in the BALL-1 culture supernatant is mediated by a novel factor which may be responsible for the clonal expansion of particular leukemic clones. (author)

  19. CO tolerance of polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Gubler, L; Scherer, G G; Wokaun, A [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    Reformed methanol can be used as a fuel for polymer electrolyte fuel cells instead of pure hydrogen. The reformate gas contains mainly H{sub 2}, CO{sub 2} in the order of 20% and low levels of CO in the order of 100 ppm. CO causes severe voltage losses due to poisoning of the anode catalyst. The effect of CO on cell performance was investigated at different CO levels up to 100 ppm. Various options to improve the CO tolerance of the fuel cell were assessed thereafter, of which the injection of a few percents of oxygen into the fuel feed stream proved to be most effective. By mixing 1% of oxygen with hydrogen containing 100 ppm CO, complete recovery of the cell performance could be attained. (author) 2 figs., 2 tabs., 3 refs.

  20. Oestrogen, an evolutionary conserved regulator of T cell differentiation and immune tolerance in jawed vertebrates?

    Science.gov (United States)

    Paiola, Matthieu; Knigge, Thomas; Duflot, Aurélie; Pinto, Patricia I S; Farcy, Emilie; Monsinjon, Tiphaine

    2018-07-01

    In teleosts, as in mammals, the immune system is tightly regulated by sexual steroid hormones, such as oestrogens. We investigated the effects of 17β-oestradiol on the expression of several genes related to T cell development and resulting T cell subpopulations in sea bass, Dicentrarchus labrax, for a primary lymphoid organ, the thymus, and two secondary lymphoid organs, the head-kidney and the spleen. In parallel, the oxidative burst capacity was assessed in leucocytes of the secondary lymphoid organs. Apoptosis- and proliferation-related genes, indicative of B and T cell clonal selection and lymphoid progenitor activity, were not affected by elevated oestrogen-levels. Sex-related oestrogen-responsiveness in T cell and antigen-presenting cell markers was observed, the expression of which was differentially induced by oestrogen-exposure in the three lymphoid organs. Remarkably, in the spleen, oestrogen increased regulatory T cell-related gene expression was associated with a decrease in oxidative burst capacity. To the best of our knowledge, this study indicates for the first time that physiological levels of oestrogen are likely to promote immune tolerance by modulating thymic function (i.e., T cell development and output) and peripheral T cells in teleosts, similar to previously reported oestrogenic effects in mammals. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Antigen-specific tolerance inhibits autoimmune uveitis in pre-sensitized animals by deletion and CD4+CD25+ T-regulatory cells.

    Science.gov (United States)

    Matta, Bharati; Jha, Purushottam; Bora, Puran S; Bora, Nalini S

    2010-02-01

    The objective of this study was to inhibit experimental autoimmune anterior uveitis (EAAU) by establishing antigen-specific immune tolerance in animals pre-sensitized with melanin-associated antigen (MAA). Intravenous administration of MAA on days 6, 7, 8 and 9 post-immunization induced tolerance and inhibited EAAU in all Lewis rats. The number of cells (total T cells, CD4(+) T cells and CD8(+) T cells) undergoing apoptosis dramatically increased in the popliteal lymph nodes (LNs) of the tolerized animals compared with non-tolerized animals. In addition, Fas ligand (FasL), TNF receptor 1 (TNFR1) and caspase-8 were upregulated in tolerized rats. Proliferation of total lymphocytes, CD4(+)T cells and CD8(+) T cells (harvested from the popliteal LNs) in response to antigenic stimulation was drastically reduced in the state of tolerance compared with the cells from non-tolerized animals. The level of interferon (IFN)-gamma and IL-2 decreased, whereas TGF-beta2 was elevated in the state of tolerance. Furthermore, the number of CD4(+)CD25(+)FoxP3(+) regulatory T cells (Tregs) increased in the popliteal LNs of tolerized animals compared with non-tolerized animals. In conclusion, our results suggest that deletion of antigen-specific T cells by apoptosis and active suppression mediated by Tregs has an important role in the induction of antigen specific immune tolerance in animals with an established immune response against MAA.

  2. Commensal Lactobacillus Controls Immune Tolerance during Acute Liver Injury in Mice

    Directory of Open Access Journals (Sweden)

    Nobuhiro Nakamoto

    2017-10-01

    Full Text Available Summary: Gut-derived microbial antigens trigger the innate immune system during acute liver injury. During recovery, regulatory immunity plays a role in suppressing inflammation; however, the precise mechanism underlying this process remains obscure. Here, we find that recruitment of immune-regulatory classical dendritic cells (cDCs is crucial for liver tolerance in concanavalin A-induced acute liver injury. Acute liver injury resulted in enrichment of commensal Lactobacillus in the gut. Notably, Lactobacillus activated IL-22 production by gut innate lymphoid cells and raised systemic IL-22 levels. Gut-derived IL-22 enhanced mucosal barrier function and promoted the recruitment of regulatory cDCs to the liver. These cDCs produced IL-10 and TGF-β through TLR9 activation, preventing further liver inflammation. Collectively, our results indicate that beneficial gut microbes influence tolerogenic immune responses in the liver. Therefore, modulation of the gut microbiota might be a potential option to regulate liver tolerance. : Nakamoto et.al. find that Lactobacillus accumulates in the gut and activates IL-22 production by innate lymphoid cells during acute liver injury. Gut-derived IL-22 contributes to liver tolerance via induction of regulatory DCs. Keywords: immune tolerance, dendritic cell, innate lymphoid cell, acute liver injury, interleukin-10, interleukin-22, microbiota, dysbiosis

  3. The flavonoid-rich fraction of Coreopsis tinctoria promotes glucose tolerance regain through pancreatic function recovery in streptozotocin-induced glucose-intolerant rats.

    Science.gov (United States)

    Dias, Teresa; Bronze, Maria Rosário; Houghton, Peter J; Mota-Filipe, Hélder; Paulo, Alexandra

    2010-11-11

    (8.35 ± 0.69 U/L) demonstrating recovery of pancreatic function. On the other hand, treatment with standard antioxidant Trolox had no effect on glucose homeostasis of glucose-intolerant rats. The oral treatment with Coreopsis tinctoria fraction caused no hepatotoxicity, as determined by blood alanine and aspartate transaminases, and had also no effect on glucose homeostasis and pancreatic function of normal rats. AcOEt fraction, containing the same amount of marein as the infusion, promoted glucose tolerance regain in the rats more quickly, which means that the bioactivity is probably due to the several flavonoids present in Coreopsis tinctoria extracts and not to marein alone. The results also strongly suggest that these compounds act by promoting pancreatic cell function recovery from STZ-induced injury, possibly through a mechanism of action other than merely antioxidant mediated. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  4. Functional clonal deletion versus suppressor cell-induced transplantation tolerance in chimeras prepared with a short course of total-lymphoid irradiation

    International Nuclear Information System (INIS)

    Slavin, S.; Morecki, S.; Weigensberg, M.; Bar, S.; Weiss, L.

    1986-01-01

    Allogeneic bone marrow (BM) chimeras induced by infusion of BM cells into recipients conditioned with total lymphoid irradiation (TLI) were shown to develop humoral and cell-mediated tolerance to host and donor-type alloantigens by a number of in vitro and in vivo assays. Spleen cells of tolerant chimeras exhibited suppressive activity of mixed lymphocyte reaction (MLR). MLR suppression was not abrogated by depletion of Lyt-2 cells, and neither could Lyt-2-positive cells sorted from the spleens of tolerant chimeras suppress MLR or attenuate graft-versus-host reactivity in vivo. Likewise, specifically unresponsive spleen cells obtained from chimeras could not be induced to respond in MLR against tolerizing host-type cells following depletion of Lyt-2 or passage through a nylon-wool column. Tolerance of chimera spleen cells to host alloantigens, best documented by permanent survival of donor-type skin allografts, could be adoptively transferred into syngeneic recipients treated by heavy irradiation but not into untreated or mildly irradiated recipients. Adoptive transfer of tolerance seemed to be associated with experimental conditions favoring engraftment of tolerant cells rather than suppression of host reactivity. We speculate that although host and/or donor-derived suppressor cells may be operating in reducing the pool of specific alloreactive clones by blocking cell proliferation in response to allogeneic challenge, the final outcome in tolerant chimeras is actual or functional deletion of alloreactive clones

  5. Opioid regulation of mu receptor internalisation: relevance to the development of tolerance and dependence.

    Science.gov (United States)

    Lopez-Gimenez, Juan F; Milligan, Graeme

    2010-11-01

    Internalisation of the mu opioid receptor from the surface of cells is generally achieved by receptor occupancy with agonist ligands of high efficacy. However, in many situations the potent analgesic morphine fails to promote internalisation effectively and whether there is a direct link between this and the propensity for the sustained use of morphine to result in both tolerance and dependence has been studied intensely. Although frequently described as a partial agonist, this characteristic appears insufficient to explain the poor capacity of morphine to promote internalisation of the mu opioid receptor. Experiments performed using both transfected cell systems and ex vivo/in vivo models have provided evidence that when morphine can promote internalisation of the mu receptor there is a decrease in the development of tolerance and dependence. Although aspects of this model are controversial, such observations suggest a number of approaches to further enhance the use of morphine as an analgesic.

  6. IL-10 and IL-27 producing dendritic cells capable of enhancing IL-10 production of T cells are induced in oral tolerance.

    Science.gov (United States)

    Shiokawa, Aya; Tanabe, Kosuke; Tsuji, Noriko M; Sato, Ryuichiro; Hachimura, Satoshi

    2009-06-30

    Oral tolerance is a key feature of intestinal immunity, generating systemic tolerance to ingested antigens (Ag). Dendritic cells (DC) have been revealed as important immune regulators, however, the precise role of DC in oral tolerance induction remains unclear. We investigated the characteristics of DC in spleen, mesenteric lymph node (MLN), and Peyer's patch (PP) after oral Ag administration in a TCR-transgenic mouse model. DC from PP and MLN of tolerized mice induced IL-10 production but not Foxp3 expression in cocultured T cells. IL-10 production was markedly increased after 5-7-day Ag administration especially in PP DC. On the other hand, IL-27 production was increased after 2-5-day Ag administration. CD11b(+) DC, which increased after ingestion of Ag, prominently expressed IL-10 and IL-27 compared with CD11b(-) DC. These results suggest that IL-10 and IL-27 producing DC are increased by interaction with antigen specific T cells in PP, and these DC act as an inducer of IL-10 producing T cells in oral tolerance.

  7. Phenotypic characterization of autoreactive B cells--checkpoints of B cell tolerance in patients with systemic lupus erythematosus.

    Directory of Open Access Journals (Sweden)

    Annett M Jacobi

    Full Text Available DNA-reactive B cells play a central role in systemic lupus erythematosus (SLE; DNA antibodies precede clinical disease and in established disease correlate with renal inflammation and contribute to dendritic cell activation and high levels of type 1 interferon. A number of central and peripheral B cell tolerance mechanisms designed to control the survival, differentiation and activation of autoreactive B cells are thought to be disturbed in patients with SLE. The characterization of DNA-reactive B cells has, however, been limited by their low frequency in peripheral blood. Using a tetrameric configuration of a peptide mimetope of DNA bound by pathogenic anti-DNA antibodies, we can identify B cells producing potentially pathogenic DNA-reactive antibodies. We, therefore, characterized the maturation and differentiation states of peptide, (ds double stranded DNA cross-reactive B cells in the peripheral blood of lupus patients and correlated these with clinical disease activity. Flow cytometric analysis demonstrated a significantly higher frequency of tetramer-binding B cells in SLE patients compared to healthy controls. We demonstrated the existence of a novel tolerance checkpoint at the transition of antigen-naïve to antigen-experienced. We further demonstrate that patients with moderately active disease have more autoreactive B cells in both the antigen-naïve and antigen-experienced compartments consistent with greater impairment in B cell tolerance in both early and late checkpoints in these patients than in patients with quiescent disease. This methodology enables us to gain insight into the development and fate of DNA-reactive B cells in individual patients with SLE and paves the way ultimately to permit better and more customized therapies.

  8. Plant Growth-Promoting Rhizobacteria Enhance Salinity Stress Tolerance in Okra through ROS-Scavenging Enzymes

    Directory of Open Access Journals (Sweden)

    Sheikh Hasna Habib

    2016-01-01

    Full Text Available Salinity is a major environmental stress that limits crop production worldwide. In this study, we characterized plant growth-promoting rhizobacteria (PGPR containing 1-aminocyclopropane-1-carboxylate (ACC deaminase and examined their effect on salinity stress tolerance in okra through the induction of ROS-scavenging enzyme activity. PGPR inoculated okra plants exhibited higher germination percentage, growth parameters, and chlorophyll content than control plants. Increased antioxidant enzyme activities (SOD, APX, and CAT and upregulation of ROS pathway genes (CAT, APX, GR, and DHAR were observed in PGPR inoculated okra plants under salinity stress. With some exceptions, inoculation with Enterobacter sp. UPMR18 had a significant influence on all tested parameters under salt stress, as compared to other treatments. Thus, the ACC deaminase-containing PGPR isolate Enterobacter sp. UPMR18 could be an effective bioresource for enhancing salt tolerance and growth of okra plants under salinity stress.

  9. Preimplantation Factor (PIF Promotes HLA-G, -E, -F, -C Expression in JEG-3 Choriocarcinoma Cells and Endogenous Progesterone Activity

    Directory of Open Access Journals (Sweden)

    Miya Soukaina Hakam

    2017-10-01

    Full Text Available Background/Aims: Pregnancy success requires mandatory maternal tolerance of the semi/ allogeneic embryo involving embryo-derived signals. Expression levels of PreImplantation Factor (PIF, a novel peptide secreted by viable embryos, correlate with embryo development, and its early detection in circulation correlates with a favourable pregnancy outcome. PIF enhances endometrial receptivity to promote embryo implantation. Via the p53 pathway, it increases trophoblast invasion, improving cell survival / immune privilege. PIF also reduces spontaneous and LPS-induced foetal death in immune naïve murine model. We examined PIF effect on gene expression of human leukocyte antigen (HLA-G, -E -F and –C and the influence of PIF on local progesterone activity in JEG-3 choriocarcinoma cells. Methods: PIF and progesterone (P4 effects on JEG-3 cells surface and intracellular HLA molecules was tested using monoclonal antibodies, flow cytometry, and Western blotting. PIF and IL17 effects on P4 and cytokines secretion was determined by ELISA. PIF and P4 effects on JEG-3 cells proteome was examined using 2D gel staining followed by spot analysis, mass spectrometry and bioinformatic analysis. Results: In cytotrophoblastic JEG-3 cells PIF increased intracellular expression of HLA-G, HLA-F, HLA-E and HLA-C and surface expression of HLA-G, HLA-E and HLA-C in dose and time dependent manner. In case of HLA-E, -F results were confirmed also by Western blot. Proteome analysis confirmed an increase in HLA-G, pro-tolerance FOXP3+ regulatory T cells (Tregs, coagulation factors and complement regulator. In contrast, PIF reduced PRDX2 and HSP70s to negate oxidative stress and protein misfolding. PIF enhanced local progesterone activity, increasing steroid secretion and the receptor protein. It also promoted the secretion of the Th1/Th2 cytokines (IL-10, IL-1β, IL-8, GM-CSF and TGF-β1, resulting in improved maternal signalling. Conclusion: PIF can generate a pro-tolerance

  10. Effects of Thy-1+ cell depletion on the capacity of donor lymphoid cells to induce tolerance across an entire MHC disparity in sublethally irradiated adult hosts

    International Nuclear Information System (INIS)

    Pierce, G.E.; Watts, L.M.

    1989-01-01

    Thy-1+ cell depletion with anti-Thy-1.2 mAb and complement markedly reduced the capacity of C57BL/6J, H-2b bone marrow to establish mixed lymphoid chimerism and induce tolerance to C57BL/6J skin grafts across an entire MHC disparity in BALB/c, H-2d hosts conditioned with sublethal, fractionated 7.5 Gy total-body irradiation. In this model tolerance can be transferred to secondary irradiated BALB/c hosts only by cells of C57BL/6J donor, not host, genotype isolated from the spleens of tolerant hosts. Thy-1+ cell depletion abolished the capacity of C57BL/6J donor cells from tolerant BALB/c host spleens to transfer tolerance. The capacity of semiallogeneic BALB/c x C57BL/6J F1, H-2d/b donor BM and spleen cells to induce chimerism and tolerance to C57BL/6J skin grafts in BALB/c parental hosts was also reduced by Thy-1+ cell depletion. Thus the requirement for donor Thy-1+ cells cannot be explained simply on the basis of alloaggression. It is unlikely that the requisite Thy-1+ cells are nonspecific suppressor cells: Thy-1+ cell depletion had no effect on the slight but significant prolongation of third-party C3H/HeJ, H-2k skin grafts in irradiated BALB/c hosts injected with allogeneic C57BL/6J or semiallogeneic BALB/c x C57BL/6J F1 BM compared to irradiated controls injected with medium only. Furthermore, injections of semiallogeneic F1 spleen cells had no significant effect on the survival of the third-party grafts, although these cells were fully capable of inducing tolerance, and their capacity to induce tolerance was significantly reduced by Thy-1+ cell depletion. The requirement for a specific population of lymphoid cells, i.e. Thy-1+, remains unexplained but suggests that donor cells might play a role in the induction or maintenance of tolerance in this model other than merely providing a circulating source of donor antigens

  11. Trichostatin A Promotes the Generation and Suppressive Functions of Regulatory T Cells

    Directory of Open Access Journals (Sweden)

    Cristian Doñas

    2013-01-01

    Full Text Available Regulatory T cells are a specific subset of lymphocytes that suppress immune responses and play a crucial role in the maintenance of self-tolerance. They can be generated in the thymus as well as in the periphery through differentiation of naïve CD4+ T cells. The forkhead box P3 transcription factor (Foxp3 is a crucial molecule regulating the generation and function of Tregs. Here we show that the foxp3 gene promoter becomes hyperacetylated in in vitro differentiated Tregs compared to naïve CD4+ T cells. We also show that the histone deacetylase inhibitor TSA stimulated the in vitro differentiation of naïve CD4+ T cells into Tregs and that this induction was accompanied by a global increase in histone H3 acetylation. Importantly, we also demonstrated that Tregs generated in the presence of TSA have phenotypical and functional differences from the Tregs generated in the absence of TSA. Thus, TSA-generated Tregs showed increased suppressive activities, which could potentially be explained by a mechanism involving the ectonucleotidases CD39 and CD73. Our data show that TSA could potentially be used to enhance the differentiation and suppressive function of CD4+Foxp3+ Treg cells.

  12. Adipose-derived mesenchymal stem cells promote cell proliferation and invasion of epithelial ovarian cancer

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Yijing; Tang, Huijuan; Guo, Yan; Guo, Jing; Huang, Bangxing; Fang, Fang; Cai, Jing, E-mail: caijingmmm@hotmail.com; Wang, Zehua, E-mail: zehuawang@163.net

    2015-09-10

    Adipose-derived mesenchymal stem cell (ADSC) is an important component of tumor microenvironment. However, whether ADSCs have a hand in ovarian cancer progression remains unclear. In this study, we investigated the impact of human ADSCs derived from the omentum of normal donors on human epithelial ovarian cancer (EOC) cells in vitro and in vivo. Direct and indirect co-culture models including ADSCs and human EOC cell lines were established and the effects of ADSCs on EOC cell proliferation were evaluated by EdU incorporation and flow cytometry. Transwell migration assays and detection of MMPs were performed to assess the invasion activity of EOC cells in vitro. Mouse models were established by intraperitoneal injection of EOC cells with or without concomitant ADSCs to investigate the role of ADSCs in tumor progression in vivo. We found that ADSCs significantly promoted proliferation and invasion of EOC cells in both direct and indirect co-culture assays. In addition, after co-culture with ADSCs, EOC cells secreted higher levels of matrix metalloproteinases (MMPs), and inhibition of MMP2 and MMP9 partially relieved the tumor-promoting effects of ADSCs in vitro. In mouse xenograft models, we confirmed that ADSCs promoted EOC growth and metastasis and elevated the expression of MMP2 and MMP9. Our findings indicate that omental ADSCs play a promotive role during ovarian cancer progression. - Highlights: • Omental adipose derived stem cells enhanced growth and invasion properties of ovarian cancer cells. • Adipose derived stem cells promoted the growth and metastasis of ovarian cancer in mice models. • Adipose derived stem cells promoted MMPs expression and secretion of ovarian cancer cells. • Elevated MMPs mediated the tumor promoting effects of ADSCs.

  13. Adipose-derived mesenchymal stem cells promote cell proliferation and invasion of epithelial ovarian cancer

    International Nuclear Information System (INIS)

    Chu, Yijing; Tang, Huijuan; Guo, Yan; Guo, Jing; Huang, Bangxing; Fang, Fang; Cai, Jing; Wang, Zehua

    2015-01-01

    Adipose-derived mesenchymal stem cell (ADSC) is an important component of tumor microenvironment. However, whether ADSCs have a hand in ovarian cancer progression remains unclear. In this study, we investigated the impact of human ADSCs derived from the omentum of normal donors on human epithelial ovarian cancer (EOC) cells in vitro and in vivo. Direct and indirect co-culture models including ADSCs and human EOC cell lines were established and the effects of ADSCs on EOC cell proliferation were evaluated by EdU incorporation and flow cytometry. Transwell migration assays and detection of MMPs were performed to assess the invasion activity of EOC cells in vitro. Mouse models were established by intraperitoneal injection of EOC cells with or without concomitant ADSCs to investigate the role of ADSCs in tumor progression in vivo. We found that ADSCs significantly promoted proliferation and invasion of EOC cells in both direct and indirect co-culture assays. In addition, after co-culture with ADSCs, EOC cells secreted higher levels of matrix metalloproteinases (MMPs), and inhibition of MMP2 and MMP9 partially relieved the tumor-promoting effects of ADSCs in vitro. In mouse xenograft models, we confirmed that ADSCs promoted EOC growth and metastasis and elevated the expression of MMP2 and MMP9. Our findings indicate that omental ADSCs play a promotive role during ovarian cancer progression. - Highlights: • Omental adipose derived stem cells enhanced growth and invasion properties of ovarian cancer cells. • Adipose derived stem cells promoted the growth and metastasis of ovarian cancer in mice models. • Adipose derived stem cells promoted MMPs expression and secretion of ovarian cancer cells. • Elevated MMPs mediated the tumor promoting effects of ADSCs

  14. Phytohormones and induction of plant-stress tolerance and defense genes by seed and foliar inoculation with Azospirillum brasilense cells and metabolites promote maize growth.

    Science.gov (United States)

    Fukami, Josiane; Ollero, Francisco Javier; Megías, Manuel; Hungria, Mariangela

    2017-12-01

    Azospirillum spp. are plant-growth-promoting bacteria used worldwide as inoculants for a variety of crops. Among the beneficial mechanisms associated with Azospirillum inoculation, emphasis has been given to the biological nitrogen fixation process and to the synthesis of phytohormones. In Brazil, the application of inoculants containing A. brasilense strains Ab-V5 and Ab-V6 to cereals is exponentially growing and in this study we investigated the effects of maize inoculation with these two strains applied on seeds or by leaf spray at the V2.5 stage growth-a strategy to relieve incompatibility with pesticides used for seed treatment. We also investigate the effects of spraying the metabolites of these two strains at V2.5. Maize growth was promoted by the inoculation of bacteria and their metabolites. When applied via foliar spray, although A. brasilense survival on leaves was confirmed by confocal microscopy and cell recovery, few cells were detected after 24 h, indicating that the effects of bacterial leaf spray might also be related to their metabolites. The major molecules detected in the supernatants of both strains were indole-3-acetic acid, indole-3-ethanol, indole-3-lactic acid and salicylic acid. RT-PCR of genes related to oxidative stress (APX1, APX2, CAT1, SOD2, SOD4) and plant defense (pathogenesis-related PR1, prp2 and prp4) was evaluated on maize leaves and roots. Differences were observed according to the gene, plant tissue, strain and method of application, but, in general, inoculation with Azospirillum resulted in up-regulation of oxidative stress genes in leaves and down-regulation in roots; contrarily, in general, PR genes were down-regulated in leaves and up-regulated in roots. Emphasis should be given to the application of metabolites, especially of Ab-V5 + Ab-V6 that in general resulted in the highest up-regulation of oxidative-stress and PR genes both in leaves and in roots. We hypothesize that the benefits of inoculation of Azospirillum on

  15. Systemic immunological tolerance to ocular antigens is mediated by TNF-related apoptosis-inducing ligand (TRAIL)-expressing CD8+ T cells*

    Science.gov (United States)

    Griffith, Thomas S.; Brincks, Erik L.; Gurung, Prajwal; Kucaba, Tamara A.; Ferguson, Thomas A.

    2010-01-01

    Systemic immunological tolerance to Ag encountered in the eye restricts the formation of potentially damaging immune responses that would otherwise be initiated at other anatomical locations. We previously demonstrated that tolerance to Ag administered via the anterior chamber (AC) of the eye required FasL-mediated apoptotic death of inflammatory cells that enter the eye in response to the antigenic challenge. Moreover, the systemic tolerance induced after AC injection of Ag was mediated by CD8+ regulatory T cells. The present study examined the mechanism by which these CD8+ regulatory T cells mediate tolerance after AC injection of Ag. AC injection of Ag did not prime CD4+ T cells, and led to increased TRAIL expression by splenic CD8+ T cells. Unlike wildtype mice, Trail−/− or Dr5−/− mice did not develop tolerance to Ag injected into the eye, even though responding lymphocytes underwent apoptosis in the AC of the eyes of these mice. CD8+ T cells from Trail−/− mice that were first injected AC with Ag were unable to transfer tolerance to naïve recipient wildtype mice, but CD8+ T cells from AC-injected wildtype or Dr5−/− mice could transfer tolerance. Importantly, the transferred wildtype (Trail+/+) CD8+ T cells were also able to decrease the number of infiltrating inflammatory cells into the eye; however, Trail−/− CD8+ T cells were unable to limit the inflammatory cell ingress. Together, our data suggest that “helpless” CD8+ regulatory T cells generated after AC injection of Ag enforce systemic tolerance in a TRAIL-dependent manner to inhibit inflammation in the eye. PMID:21169546

  16. Pancreatic stellate cells promote epithelial-mesenchymal transition in pancreatic cancer cells

    International Nuclear Information System (INIS)

    Kikuta, Kazuhiro; Masamune, Atsushi; Watanabe, Takashi; Ariga, Hiroyuki; Itoh, Hiromichi; Hamada, Shin; Satoh, Kennichi; Egawa, Shinichi; Unno, Michiaki; Shimosegawa, Tooru

    2010-01-01

    Research highlights: → Recent studies have shown that pancreatic stellate cells (PSCs) promote the progression of pancreatic cancer. → Pancreatic cancer cells co-cultured with PSCs showed loose cell contacts and scattered, fibroblast-like appearance. → PSCs decreased the expression of epithelial markers but increased that of mesenchymal markers, along with increased migration. → This study suggests epithelial-mesenchymal transition as a novel mechanism by which PSCs contribute to the aggressive behavior of pancreatic cancer cells. -- Abstract: The interaction between pancreatic cancer cells and pancreatic stellate cells (PSCs), a major profibrogenic cell type in the pancreas, is receiving increasing attention. There is accumulating evidence that PSCs promote the progression of pancreatic cancer by increasing cancer cell proliferation and invasion as well as by protecting them from radiation- and gemcitabine-induced apoptosis. Because epithelial-mesenchymal transition (EMT) plays a critical role in the progression of pancreatic cancer, we hypothesized that PSCs promote EMT in pancreatic cancer cells. Panc-1 and SUIT-2 pancreatic cancer cells were indirectly co-cultured with human PSCs isolated from patients undergoing operation for pancreatic cancer. The expression of epithelial and mesenchymal markers was examined by real-time PCR and immunofluorescent staining. The migration of pancreatic cancer cells was examined by scratch and two-chamber assays. Pancreatic cancer cells co-cultured with PSCs showed loose cell contacts and a scattered, fibroblast-like appearance. The expression of E-cadherin, cytokeratin 19, and membrane-associated β-catenin was decreased, whereas vimentin and Snail (Snai-1) expression was increased more in cancer cells co-cultured with PSCs than in mono-cultured cells. The migration of pancreatic cancer cells was increased by co-culture with PSCs. The PSC-induced decrease of E-cadherin expression was not altered by treatment with anti

  17. In vitro selection of mutants: Inducible gene regulation for salt tolerance

    International Nuclear Information System (INIS)

    Winicov, I.; Bastola, D.R.; Deutch, C.E.; Pethe, V.V.; Petrusa, L.

    2001-01-01

    Regulation of differentially expressed genes in plants may be involved in inducing tolerance to stress. Isogenic salt-sensitive and salt-tolerant alfalfa lines were investigated for molecular differences in their response to salt. The genes, which are differentially induced by salt in the salt-tolerant alfalfa cells and are also regulated by salt at the whole plant level, were cloned. Both transcriptional and post- transcriptional mechanisms influenced salt-induced product accumulation in the salt-tolerant alfalfa. The salt-tolerant plants doubled proline concentration rapidly in roots, while salt-sensitive plants showed a delayed response. To understand the regulatory system in the salt-tolerant alfalfa, two genes that are expressed in roots were studied. Alfin1 encodes a zinc-finger type putative DNA transcription factor conserved in alfalfa, rice and Arabidopsis, and MsPRP2 encodes a protein that serves as a cell wall- membrane linker in roots. Recombinant Alfin1 protein was selected, amplified, cloned and its consensus sequence was identified. The recombinant Alfin1 also bound specifically to fragments of the MsPRP2 promoter in vitro, containing the Alfin1 binding consensus sequence. The results show unambiguously binding specificity of Alfin1 DNA, supporting its role in gene regulation. Alfin1 function was tested in transformed alfalfa in vivo by over-expressing Alfin1 from 35S CaMV promoter. The transgenic plants appeared normal. However, plants harboring the anti-sense construct did not grow well in soil, indicating that Alfin1 expression was essential. Alfin1 over-expression in transgenic alfalfa led to enhanced levels of MsPRP2 transcript accumulation, demonstrating that Alfin1 functioned in vivo in gene regulation. Since MsPRP2 gene is also induced by salt, it is likely that Alfin1 is an important transcription factor for gene regulation in salt-tolerant alfalfa, and an excellent target for manipulation to improve salt tolerance. (author)

  18. Adult Tissue-Derived Stem Cells and Tolerance Induction in Nonhuman Primates for Vascularized Composite Allograft Transplantation

    Science.gov (United States)

    2017-10-01

    AWARD NUMBER: W81XWH-16-2-0042 TITLE: Adult Tissue-Derived Stem Cells and Tolerance Induction in Nonhuman Primates for Vascularized Composite...2017 2. REPORT TYPE Annual 3. DATES COVERED 30 Sep 2016 - 29 Sep 2017 4. TITLE AND SUBTITLE Adult Tissue-Derived Stem Cells and Tolerance Induction...Distribution Unlimited 13. SUPPLEMENTARY NOTES The utilization of adult derived adipose stem cells administration in composite tissue transplantation

  19. B lymphocytes confer immune tolerance via cell surface GARP-TGF-β complex.

    Science.gov (United States)

    Wallace, Caroline H; Wu, Bill X; Salem, Mohammad; Ansa-Addo, Ephraim A; Metelli, Alessandra; Sun, Shaoli; Gilkeson, Gary; Shlomchik, Mark J; Liu, Bei; Li, Zihai

    2018-04-05

    GARP, a cell surface docking receptor for binding and activating latent TGF-β, is highly expressed by platelets and activated Tregs. While GARP is implicated in immune invasion in cancer, the roles of the GARP-TGF-β axis in systemic autoimmune diseases are unknown. Although B cells do not express GARP at baseline, we found that the GARP-TGF-β complex is induced on activated human and mouse B cells by ligands for multiple TLRs, including TLR4, TLR7, and TLR9. GARP overexpression on B cells inhibited their proliferation, induced IgA class-switching, and dampened T cell-independent antibody production. In contrast, B cell-specific deletion of GARP-encoding gene Lrrc32 in mice led to development of systemic autoimmune diseases spontaneously as well as worsening of pristane-induced lupus-like disease. Canonical TGF-β signaling more readily upregulates GARP in Peyer patch B cells than in splenic B cells. Furthermore, we demonstrated that B cells are required for the induction of oral tolerance of T cell-dependent antigens via GARP. Our studies reveal for the first time to our knowledge that cell surface GARP-TGF-β is an important checkpoint for regulating B cell peripheral tolerance, highlighting a mechanism of autoimmune disease pathogenesis.

  20. Role of PD1/PDL1 pathway, and TH17 and treg cells in maternal tolerance to the fetus

    Directory of Open Access Journals (Sweden)

    Sudipta Tripathi

    2015-02-01

    Full Text Available Tolerance of the fetus by the maternal immune system is regulated through various mechanisms involving the different immune cells, both in the periphery and locally at the feto-maternal interface. The maternal T lymphocytes are aware of the paternal fetal antigens and a state of dynamic T cell homeostasis is maintained in the uterus during gestation, which involves increase in antigen-specific regulatory T cell (Treg proliferation, increase in apoptosis of antigen-specific effector T cells, and inhibition of excessive inflammation post successful implantation to ensure tolerance to the fetus. The Tregs play an important role in the maintenance of tolerance during gestation. Recently, the inflammatory T helper type 17 (Th17 cells are reported to have a role in loss of tolerance to the fetus. The interaction between costimulatory molecule programmed death 1 (PD1 and its ligand PDL1 is known to play a role in regulating both the Tregs and Th17 cells. Here we discuss how the PD1/PDL1 pathway affects these two T cell populations and its role in feto-maternal tolerance.

  1. Immunity and Tolerance Induced by Intestinal Mucosal Dendritic Cells

    Directory of Open Access Journals (Sweden)

    Julio Aliberti

    2016-01-01

    Full Text Available Dendritic cells present in the digestive tract are constantly exposed to environmental antigens, commensal flora, and invading pathogens. Under steady-state conditions, these cells have high tolerogenic potential, triggering differentiation of regulatory T cells to protect the host from unwanted proinflammatory immune responses to innocuous antigens or commensals. On the other hand, these cells must discriminate between commensal flora and invading pathogens and mount powerful immune response against pathogens. A potential result of unbalanced tolerogenic versus proinflammatory responses mediated by dendritic cells is associated with chronic inflammatory conditions, such as Crohn’s disease, ulcerative colitis, food allergies, and celiac disease. Herein, we review the dendritic cell population involved in mediating tolerance and immunity in mucosal surfaces, the progress in unveiling their development in vivo, and factors that can influence their functions.

  2. Orchestration of transplantation tolerance by regulatory dendritic cell therapy or in-situ targeting of dendritic cells.

    Science.gov (United States)

    Morelli, Adrian E; Thomson, Angus W

    2014-08-01

    Extensive research in murine transplant models over the past two decades has convincingly demonstrated the ability of regulatory dendritic cells (DCregs) to promote long-term allograft survival. We review important considerations regarding the source of therapeutic DCregs (donor or recipient) and their mode of action, in-situ targeting of DCregs, and optimal therapeutic regimens to promote DCreg function. Recent studies have defined protocols and mechanisms whereby ex-vivo-generated DCregs of donor or recipient origin subvert allogeneic T-cell responses and promote long-term organ transplant survival. Particular interest has focused on how donor antigen is acquired, processed and presented by autologous dendritic cells, on the stability of DCregs, and on in-situ targeting of dendritic cells to promote their tolerogenic function. New evidence of the therapeutic efficacy of DCregs in a clinically relevant nonhuman primate organ transplant model and production of clinical grade DCregs support early evaluation of DCreg therapy in human graft recipients. We discuss strategies currently used to promote dendritic cell tolerogenicity, including DCreg therapy and in-situ targeting of dendritic cells, with a view to improved understanding of underlying mechanisms and identification of the most promising strategies for therapeutic application.

  3. Repurposing Lesogaberan to Promote Human Islet Cell Survival and β-Cell Replication

    Directory of Open Access Journals (Sweden)

    Jide Tian

    2017-01-01

    Full Text Available The activation of β-cell’s A- and B-type gamma-aminobutyric acid receptors (GABAA-Rs and GABAB-Rs can promote their survival and replication, and the activation of α-cell GABAA-Rs promotes their conversion into β-cells. However, GABA and the most clinically applicable GABA-R ligands may be suboptimal for the long-term treatment of diabetes due to their pharmacological properties or potential side-effects on the central nervous system (CNS. Lesogaberan (AZD3355 is a peripherally restricted high-affinity GABAB-R-specific agonist, originally developed for the treatment of gastroesophageal reflux disease (GERD that appears to be safe for human use. This study tested the hypothesis that lesogaberan could be repurposed to promote human islet cell survival and β-cell replication. Treatment with lesogaberan significantly enhanced replication of human islet cells in vitro, which was abrogated by a GABAB-R antagonist. Immunohistochemical analysis of human islets that were grafted into immune-deficient mice revealed that oral treatment with lesogaberan promoted human β-cell replication and islet cell survival in vivo as effectively as GABA (which activates both GABAA-Rs and GABAB-Rs, perhaps because of its more favorable pharmacokinetics. Lesogaberan may be a promising drug candidate for clinical studies of diabetes intervention and islet transplantation.

  4. Simultaneous bone marrow and composite tissue transplantation in rats treated with nonmyeloablative conditioning promotes tolerance1

    Science.gov (United States)

    Xu, Hong; Ramsey, Deborah M.; Wu, Shengli; Bozulic, Larry D.; Ildstad, Suzanne T.

    2012-01-01

    Background Approaches to safely induce tolerance in vascularized composite allotransplantation (VCA) with chimerism through bone marrow transplantation (BMT) are currently being pursued. However, the VCA were historically performed sequentially after donor chimerism was established. Delayed VCA is not clinically applicable due to the time constraints associated with procurement from deceased donors. A more clinically relevant approach to perform both the BMT and VCA simultaneously was evaluated. Methods WF (RT1Au) rats were treated with a short course of immunosuppressive therapy (anti-αβ-TCR mAb, FK-506, and anti-lymphocyte serum). One day prior to BMT, rats were treated with varying doses of total body irradiation (TBI) followed by transplantation of heterotopic osteomyocutaneous flaps from hind limbs of ACI (RT1Aabl) rats. Results 80% of rats conditioned with 300 cGy TBI and 40% of rats receiving 400 cGy TBI accepted the VCA. Mixed chimerism was detected in peripheral blood at one month post-VCA, but chimerism was lost in all transplant recipients by 4 months. The majority of peripheral donor cells originated from the BMT and not the VCA. Acceptors of VCA were tolerant of a donor skin graft challenge and no anti-donor antibodies were detectable, suggesting a central deletional mechanism for tolerance. Regulatory T cells (Treg) from spleens of acceptors more potently suppressed lymphocyte proliferation than Treg from rejectors in the presence of donor stimulator cells. Conclusions These studies suggest that simultaneous BMT and VCA may establish indefinite allograft survival in rats through Treg-mediated suppression and thymic deletion of alloreactive T cells. PMID:23250336

  5. Th17 cell-mediated immune responses promote mast cell proliferation by triggering stem cell factor in keratinocytes

    International Nuclear Information System (INIS)

    Cho, Kyung-Ah; Park, Minhwa; Kim, Yu-Hee; Woo, So-Youn

    2017-01-01

    Although mast cells are traditionally thought to function as effector cells in allergic responses, they have increasingly been recognized as important regulators of various immune responses. Mast cells mature locally; thus, tissue-specific influences are important for promoting mast cell accumulation and survival in the skin and the gastrointestinal tract. In this study, we determined the effects of keratinocytes on mast cell accumulation during Th17-mediated skin inflammation. We observed increases in dermal mast cells in imiquimod-induced psoriatic dermatitis in mice accompanied by the expression of epidermal stem cell factor (SCF), a critical mast cell growth factor. Similar to mouse epidermal keratinocytes, SCF was highly expressed in the human HaCaT keratinocyte cell line following stimulation with IL−17. Further, keratinocytes promoted mast cell proliferation following stimulation with IL−17 in vitro. However, the effects of keratinocytes on mast cells were significantly diminished in the presence of anti−CD117 (stem cell factor receptor) blocking antibodies. Taken together, our results revealed that the Th17-mediated inflammatory environment promotes mast cell accumulation through keratinocyte-derived SCF. - Highlights: • Psoriasis-like skin inflammation increase dermal mast cells. • Keratinocyte produce stem cell factor in psoriasis-like skin inflammation. • Keratinocyte promote mast cell proliferation by stem cell factor dependent manner

  6. Peptide-Conjugated Nanoparticles Reduce Positive Co-stimulatory Expression and T Cell Activity to Induce Tolerance.

    Science.gov (United States)

    Kuo, Robert; Saito, Eiji; Miller, Stephen D; Shea, Lonnie D

    2017-07-05

    Targeted approaches to treat autoimmune diseases would improve upon current therapies that broadly suppress the immune system and lead to detrimental side effects. Antigen-specific tolerance was induced using poly(lactide-co-glycolide) nanoparticles conjugated with disease-relevant antigen to treat a model of multiple sclerosis. Increasing the nanoparticle dose and amount of conjugated antigen both resulted in more durable immune tolerance. To identify active tolerance mechanisms, we investigated downstream cellular and molecular events following nanoparticle internalization by antigen-presenting cells. The initial cell response to nanoparticles indicated suppression of inflammatory signaling pathways. Direct and functional measurement of surface MHC-restricted antigen showed positive correlation with both increasing particle dose from 1 to 100 μg/mL and increasing peptide conjugation by 2-fold. Co-stimulatory analysis of cells expressing MHC-restricted antigen revealed most significant decreases in positive co-stimulatory molecules (CD86, CD80, and CD40) following high doses of nanoparticles with higher peptide conjugation, whereas expression of a negative co-stimulatory molecule (PD-L1) remained high. T cells isolated from mice immunized against myelin proteolipid protein (PLP 139-151 ) were co-cultured with antigen-presenting cells administered PLP 139-151 -conjugated nanoparticles, which resulted in reduced T cell proliferation, increased T cell apoptosis, and a stronger anti-inflammatory response. These findings indicate several potential mechanisms used by peptide-conjugated nanoparticles to induce antigen-specific tolerance. Copyright © 2017 The American Society of Gene and Cell Therapy. Published by Elsevier Inc. All rights reserved.

  7. T cell ignorance is bliss: T cells are not tolerized by Langerhans cells presenting human papillomavirus antigens in the absence of costimulation

    Directory of Open Access Journals (Sweden)

    Andrew W. Woodham

    2016-12-01

    Full Text Available Human papillomavirus type 16 (HPV16 infections are intra-epithelial, and thus, HPV16 is known to interact with Langerhans cells (LCs, the resident epithelial antigen-presenting cells (APCs. The current paradigm for APC-mediated induction of T cell anergy is through delivery of T cell receptor signals via peptides on MHC molecules (signal 1, but without costimulation (signal 2. We previously demonstrated that LCs exposed to HPV16 in vitro present HPV antigens to T cells without costimulation, but it remained uncertain if such T cells would remain ignorant, become anergic, or in the case of CD4+ T cells, differentiate into Tregs. Here we demonstrate that Tregs were not induced by LCs presenting only signal 1, and through a series of in vitro immunizations show that CD8+ T cells receiving signal 1+2 from LCs weeks after consistently receiving signal 1 are capable of robust effector functions. Importantly, this indicates that T cells are not tolerized but instead remain ignorant to HPV, and are activated given the proper signals. Keywords: T cell anergy, T cell ignorance, Immune tolerance, Human papillomavirus, HPV16, Langerhans cells

  8. The role of retinoic acid in tolerance and immunity.

    Science.gov (United States)

    Hall, Jason A; Grainger, John R; Spencer, Sean P; Belkaid, Yasmine

    2011-07-22

    Vitamin A elicits a broad array of immune responses through its metabolite, retinoic acid (RA). Recent evidence indicates that loss of RA leads to impaired immunity, whereas excess RA can potentially promote inflammatory disorders. In this review, we discuss recent advances showcasing the crucial contributions of RA to both immunological tolerance and the elicitation of adaptive immune responses. Further, we provide a comprehensive overview of the cell types and factors that control the production of RA and discuss how host perturbations may affect the ability of this metabolite to control tolerance and immunity or to instigate pathology. Copyright © 2011 Elsevier Inc. All rights reserved.

  9. Incorporation of [14C]-palmitate into lipids of Brassica cells during the induction of freezing tolerance

    International Nuclear Information System (INIS)

    Lynch, D.V.; Joseph, R.A.

    1989-01-01

    Changes in plasma membrane lipid composition have been causally related to increased freezing tolerance. Studies of lipid metabolism during ABA induction of freezing tolerance in Brassica napus suspension cultures were undertaken. Cells were labeled with [ 14 C]-palmitate four days after transfer to fresh medium (control) or medium containing ABA (which increases freezing tolerance). At times between one and 20 hrs after labeling, ABA-treated cells incorporated almost twice the amount of label as controls cells. Approximately 80% of the radioactivity was associated with neutral lipids in ABA-treated cells and controls. Incorporation of label into total cellular polar lipids was 4.9 x 10 5 dpm/mg protein for control cells and 1 x 10 6 dpm/mg protein for cells transferred to medium containing ABA. Analysis of lipids following alkaline hydrolysis indicated that incorporation of [ 14 C]-palmitate into glucosylceramide of ABA-treated cells was less than 60% of control values when expressed relative to that of the total polar lipids. Incorporation into ceramides was also depressed in ABA-treated cells

  10. Tolerance induction to a thymus-dependent antigen in vitro: treatment of nonadherent cells with tolerogen biologically filtered in vitro

    International Nuclear Information System (INIS)

    Geyer, J.W.; Kong, Y.M.

    1974-01-01

    Highly tolerogenic bovine gamma globulin (BGG), a thymus-dependent antigen, was prepared by biologic filtration in vitro. It readily induced tolerance in vivo in BALB/c mice and also rendered their nonadherent lymph node cells tolerant after in vitro incubation. Biologic filtration in vitro was carried out by incubating 2.5 x 10 7 lymph node cells with 10 mg of nontolerogenic BGG in 10 ml of Eagle's medium containing 2 percent normal mouse serum at 37 0 C for 6 hr. The BGG-containing medium was clarified by centrifugation and was used without further dilution. For tolerance induction in vitro, lymph node cells were separated into adherent and nonadherent populations on Falcon plastic. These cells were incubated for 0 to 18 hr at 37 0 C with biologically filtered BGG (bBGG). After incubation, the cells were washed three times and (2 to 2.5) x 10 7 nonadherent or 4 x 10 6 adherent cells were injected iv with their untreated counterpart into lethally irradiated mice which had received 10 6 bone marrow cells. The recipients were then challenged with 300 μg of aggregated BGG, and tolerance was assayed by the elimination of labeled BGG, rosette formation, and passive hemagglutination. Spleen cells were similarly treated for comparison. Our findings show that tolerance was not induced in vitro in adherent lymph node cells. However, in the nonadherent populations, those from the lymph node but not the spleen were rendered tolerant. The acquisition of tolerance in vitro was gradual. It was dependent upon the length of exposure to bBGG and required at least 6 hr

  11. Arsenic-tolerant plant-growth-promoting bacteria isolated from arsenic-polluted soils in South Korea.

    Science.gov (United States)

    Shagol, Charlotte C; Krishnamoorthy, Ramasamy; Kim, Kiyoon; Sundaram, Subbiah; Sa, Tongmin

    2014-01-01

    The Janghang smelter in Chungnam, South Korea started in 1936 was subsequently shutdown in 1989 due to heavy metal (loid) pollution concerns in the vicinity. Thus, there is a need for the soil in the area to be remediated to make it usable again especially for agricultural purposes. The present study was conducted to exploit the potential of arsenic (As)-tolerant bacteria thriving in the vicinity of the smelter-polluted soils to enhance phytoremediation of hazardous As. We studied the genetic and taxonomic diversity of 21 As-tolerant bacteria isolated from soils nearer to and away from the smelter. These isolates belonging to the genera Brevibacterium, Pseudomonas, Microbacterium, Rhodococcus, Rahnella, and Paenibacillus, could tolerate high concentrations of arsenite (As(III)) and arsenate (As(V)) with the minimum inhibitory concentration ranging from 3 to >20 mM for NaAsO2 and 140 to 310 mM NaH2AsO4 · 7H2O, respectively. All isolates exhibited As(V) reduction except Pseudomonas koreensis JS123, which exhibited both oxidation and reduction of As. Moreover, all the 21 isolates produced indole acetic acid (IAA), 13 isolates exhibited 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, 12 produced siderophore, 17 solubilized phosphate, and 13 were putative nitrogen fixers under in vitro conditions. Particularly, Rhodococcus aetherivorans JS2210, P. koreensis JS2214, and Pseudomonas sp. JS238 consistently increased root length of maize in the presence of 100 and 200 μM As(V). Possible utilization of these As-tolerant plant-growth-promoting bacteria can be a potential strategy in increasing the efficiency of phytoremediation in As-polluted soils.

  12. Difference in the distribution and speciation of cellular nickel between nickel-tolerant and non-tolerant Nicotiana tabacum L. cv. BY-2 cells.

    Science.gov (United States)

    Saito, Akihiro; Saito, Misa; Ichikawa, Yusuke; Yoshiba, Masaaki; Tadano, Toshiaki; Miwa, Eitaro; Higuchi, Kyoko

    2010-02-01

    To evaluate Ni dynamics at the subcellular level, the distribution and speciation of Ni were determined in wild-type (WT) and Ni-tolerant (NIT) tobacco BY-2 cell lines. When exposed to low but toxic levels of Ni, NIT cells were found to contain 2.5-fold more Ni (14% of whole-cell Ni values) in their cell walls than WT cells (6% of whole-cell Ni values). In addition to higher levels of Ni in the apoplast, a higher proportion (94%) of symplastic Ni was localized in the vacuoles of NIT cells than in the vacuoles of WT cells (81%). The concentration of cytosolic Ni in the NIT cells was significantly lower (18 nmol g(-1) FW) than that in the WT cells (85 nmol g(-1) FW). In silico simulation showed that 95% of vacuolar Ni was in the form of Ni-citrate complexes, and that free Ni(2+) was virtually absent in the NIT cells. On the other hand, the amount of free metal ions was markedly increased in WT cells because free citrate was depleted by chelation of Ni. A protoplast viability assay using BCECF-AM further demonstrated that the main mechanism that confers strong Ni tolerance was present in the symplast as opposed to the cell wall.

  13. Adipose tissue-derived stem cells promote pancreatic cancer cell proliferation and invasion

    International Nuclear Information System (INIS)

    Ji, S.Q.; Cao, J.; Zhang, Q.Y.; Li, Y.Y.; Yan, Y.Q.; Yu, F.X.

    2013-01-01

    To explore the effects of adipose tissue-derived stem cells (ADSCs) on the proliferation and invasion of pancreatic cancer cells in vitro and the possible mechanism involved, ADSCs were cocultured with pancreatic cancer cells, and a cell counting kit (CCK-8) was used to detect the proliferation of pancreatic cancer cells. ELISA was used to determine the concentration of stromal cell-derived factor-1 (SDF-1) in the supernatants. RT-PCR was performed to detect the expression of the chemokine receptor CXCR4 in pancreatic cancer cells and ADSCs. An in vitro invasion assay was used to measure invasion of pancreatic cancer cells. SDF-1 was detected in the supernatants of ADSCs, but not in pancreatic cancer cells. Higher CXCR4 mRNA levels were detected in the pancreatic cancer cell lines compared with ADSCs (109.3±10.7 and 97.6±7.6 vs 18.3±1.7, respectively; P<0.01). In addition, conditioned medium from ADSCs promoted the proliferation and invasion of pancreatic cancer cells, and AMD3100, a CXCR4 antagonist, significantly downregulated these growth-promoting effects. We conclude that ADSCs can promote the proliferation and invasion of pancreatic cancer cells, which may involve the SDF-1/CXCR4 axis

  14. Adipose tissue-derived stem cells promote pancreatic cancer cell proliferation and invasion

    Energy Technology Data Exchange (ETDEWEB)

    Ji, S.Q.; Cao, J. [Department of Liver Surgery I, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai (China); Zhang, Q.Y.; Li, Y.Y. [Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Wenzhou Medical College, Wenzhou (China); Yan, Y.Q. [Department of Liver Surgery I, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai (China); Yu, F.X. [Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Wenzhou Medical College, Wenzhou (China)

    2013-09-27

    To explore the effects of adipose tissue-derived stem cells (ADSCs) on the proliferation and invasion of pancreatic cancer cells in vitro and the possible mechanism involved, ADSCs were cocultured with pancreatic cancer cells, and a cell counting kit (CCK-8) was used to detect the proliferation of pancreatic cancer cells. ELISA was used to determine the concentration of stromal cell-derived factor-1 (SDF-1) in the supernatants. RT-PCR was performed to detect the expression of the chemokine receptor CXCR4 in pancreatic cancer cells and ADSCs. An in vitro invasion assay was used to measure invasion of pancreatic cancer cells. SDF-1 was detected in the supernatants of ADSCs, but not in pancreatic cancer cells. Higher CXCR4 mRNA levels were detected in the pancreatic cancer cell lines compared with ADSCs (109.3±10.7 and 97.6±7.6 vs 18.3±1.7, respectively; P<0.01). In addition, conditioned medium from ADSCs promoted the proliferation and invasion of pancreatic cancer cells, and AMD3100, a CXCR4 antagonist, significantly downregulated these growth-promoting effects. We conclude that ADSCs can promote the proliferation and invasion of pancreatic cancer cells, which may involve the SDF-1/CXCR4 axis.

  15. Assessment of Methylobacterium oryzae CBMB20 aggregates for salt tolerance and plant growth promoting characteristics for bio-inoculant development.

    Science.gov (United States)

    Chanratana, Mak; Han, Gwang Hyun; Roy Choudhury, Aritra; Sundaram, Seshadri; Halim, Md Abdul; Krishnamoorthy, Ramasamy; Kang, Yeongyeong; Sa, Tongmin

    2017-11-21

    Salinity is one of the major factors contributing to the loss of crop productivity and thereby impacting livelihood of people in more than 100 countries of the world and the area of land affected by salinity is increasing day by day. This will worsen due to various factors such as drought that might result in high soil salinity. Use of plant growth promoting rhizobacteria is one of the promising eco-friendly strategies for salinity stress management as part of sustainable agricultural practices. However, it requires selecting rhizobacteria with good survivability and adaptation to salt stress. In this study we report aggregation of Methylobacterium oryzae CBMB20 cells grown in media containing high C/N ratio (30:1) than in media containing low C/N ratio (7:1). Aggregated Methylobacterium oryzae CBMB20 cells exhibited enhanced tolerance to UV irradiation, heat, desiccation, different temperature regimes, oxidative stress, starvation and supported higher population in media. Poly-β-hydroxybutyrate accumulation, exopolysaccharide production, proline accumulation and biofilm formation were good at 100 mM salt concentration with good microbial cell hydrophobicity at both 50 and 100 mM than other concentrations. Both the aggregated and non-aggregated cells grown under 0-200 mM salt concentrations produced IAA even at 200 mM salt concentration with a peak at 100 mM concentration with aggregated cells producing significantly higher quantities. ACC deaminase activity was observed in all NaCl concentrations studied with gradual and drastic reduction in aggregated and non-aggregated cells over increased salt concentrations.

  16. Growth Response and Tolerance to Heavy Metals of two Swamp Species inoculated with a Plant Growth-Promoting Rhizobacteria

    International Nuclear Information System (INIS)

    Rodriguez-Dorantes, A.; Labra-Cardon, D.; Guerrero-Zuniga, A.; Montes-Villafan, S.

    2009-01-01

    Due to the sensitivity and the sequestration ability of the microbial communities to heavy metals, microbes have been used for bioremediation. Recently the application of plant growth-promoting rhizobacteria (PGPR) for the bioremediation of this kind of contaminants has been done. This study evaluated the growth response and the tolerance to heavy metals of two swamp species. (Author)

  17. Bacillus aryabhattai SRB02 tolerates oxidative and nitrosative stress and promotes the growth of soybean by modulating the production of phytohormones

    Science.gov (United States)

    Kang, Sang-Mo; Shahzad, Raheem; Seo, Chang-Woo; Kim, Ah-Yeong; Lee, Sang-Uk; Oh, Kyeong Yeol; Lee, Dong Yeol; Lee, In-Jung; Yun, Byung-Wook

    2017-01-01

    Plant growth promoting rhizobacteria (PGPR) are diverse, naturally occurring bacteria that establish a close association with plant roots and promote the growth and immunity of plants. Established mechanisms involved in PGPR-mediated plant growth promotion include regulation of phytohormones, improved nutrient availability, and antagonistic effects on plant pathogens. In this study, we isolated a bacterium from the rhizospheric soil of a soybean field in Chungcheong buk-do, South Korea. Using 16S rRNA sequencing, the bacterium was identified as Bacillus aryabhattai strain SRB02. Here we show that this strain significantly promotes the growth of soybean. Gas chromatography—mass spectrometry analysis showed that SRB02 produced significant amounts of abscisic acid, indole acetic acid, cytokinin and different gibberellic acids in culture. SRB02-treated soybean plants showed significantly better heat stress tolerance than did untreated plants. These plants also produced consistent levels of ABA under heat stress and exhibited ABA-mediated stomatal closure. High levels of IAA, JA, GA12, GA4, and GA7, were recorded in SRB02-treated plants. These plants produced longer roots and shoots than those of control plants. B. aryabhattai SRB02 was found to be highly tolerant to oxidative stress induced by H2O2 and MV potentiated by high catalase (CAT) and superoxide dismutase (SOD) activities. SRB02 also tolerated high nitrosative stress induced by the nitric oxide donors GSNO and CysNO. Because of these attributes, B. aryabhattai SRB02 may prove to be a valuable resource for incorporation in biofertilizers and other soil amendments that seek to improve crop productivity. PMID:28282395

  18. Bacillus aryabhattai SRB02 tolerates oxidative and nitrosative stress and promotes the growth of soybean by modulating the production of phytohormones.

    Directory of Open Access Journals (Sweden)

    Yeon-Gyeong Park

    Full Text Available Plant growth promoting rhizobacteria (PGPR are diverse, naturally occurring bacteria that establish a close association with plant roots and promote the growth and immunity of plants. Established mechanisms involved in PGPR-mediated plant growth promotion include regulation of phytohormones, improved nutrient availability, and antagonistic effects on plant pathogens. In this study, we isolated a bacterium from the rhizospheric soil of a soybean field in Chungcheong buk-do, South Korea. Using 16S rRNA sequencing, the bacterium was identified as Bacillus aryabhattai strain SRB02. Here we show that this strain significantly promotes the growth of soybean. Gas chromatography-mass spectrometry analysis showed that SRB02 produced significant amounts of abscisic acid, indole acetic acid, cytokinin and different gibberellic acids in culture. SRB02-treated soybean plants showed significantly better heat stress tolerance than did untreated plants. These plants also produced consistent levels of ABA under heat stress and exhibited ABA-mediated stomatal closure. High levels of IAA, JA, GA12, GA4, and GA7, were recorded in SRB02-treated plants. These plants produced longer roots and shoots than those of control plants. B. aryabhattai SRB02 was found to be highly tolerant to oxidative stress induced by H2O2 and MV potentiated by high catalase (CAT and superoxide dismutase (SOD activities. SRB02 also tolerated high nitrosative stress induced by the nitric oxide donors GSNO and CysNO. Because of these attributes, B. aryabhattai SRB02 may prove to be a valuable resource for incorporation in biofertilizers and other soil amendments that seek to improve crop productivity.

  19. Boron Supply Enhances Aluminum Tolerance in Root Border Cells of Pea (Pisum sativum by Interacting with Cell Wall Pectins

    Directory of Open Access Journals (Sweden)

    Xue Wen Li

    2017-05-01

    Full Text Available Aluminum (Al toxicity is the primary factor limiting crop growth in acidic soils. Boron (B alleviates Al toxicity in plants, which is mainly considered to be due to the formation of Rhamnogalacturonan II-B (RGII-B complexes, which helps to stabilize the cytoskeleton. It is unclear yet whether this is due to the increasing of net negative charges and/or further mechanisms. Kinetics of Al accumulation and adsorption were investigated using entire cells, cell wall and pectin of root border cells (RBCs of pea (Pisum sativum, to reveal the mechanism of B in interacting with alkali-soluble and chelator-soluble pectin for an increased Al tolerance in RBCs. The results show that B could rescue RBCs from Al-induced cell death by accumulating more Al in the cell wall, predominately in alkali-soluble pectin. Boron also promotes Al3+ adsorption and inhibits Al3+ desorption from alkali-soluble pectin. Thus, more Al3+ is immobilized within the alkali-soluble pectin fraction and less in the chelator-soluble pectin, rendering Al3+ less mobile. Boron induces an increase of RG-II (KDO,2-keto-3-deoxyoctonic acid content for forming more borate-RGII complexes, and the decrease of pectin methyl-esterification, thus creates more negative charges to immobilize Al3+ in cell wall pectin. The study provides evidence that abundant B supply enhances the immobilization of Al in alkali-soluble pectin, thus most likely reducing the entry of Al3+ into the symplast from the surroundings.

  20. Induction of drought tolerance in cucumber plants by a consortium of three plant growth-promoting rhizobacterium strains.

    Directory of Open Access Journals (Sweden)

    Chun-Juan Wang

    Full Text Available Our previous work showed that a consortium of three plant growth-promoting rhizobacterium (PGPR strains (Bacillus cereus AR156, Bacillus subtilis SM21, and Serratia sp. XY21, termed as BBS for short, was a promising biocontrol agent. The present study investigated its effect on drought tolerance in cucumber plants. After withholding watering for 13 days, BBS-treated cucumber plants had much darker green leaves and substantially lighter wilt symptoms than control plants. Compared to the control, the BBS treatment decreased the leaf monodehydroascorbate (MDA content and relative electrical conductivity by 40% and 15%, respectively; increased the leaf proline content and the root recovery intension by 3.45-fold and 50%, respectively; and also maintained the leaf chlorophyll content in cucumber plants under drought stress. Besides, in relation to the control, the BBS treatment significantly enhanced the superoxide dismutase (SOD activity and mitigated the drought-triggered down-regulation of the expression of the genes cAPX, rbcL, and rbcS encoding cytosolic ascorbate peroxidase, and ribulose-1,5-bisphosphate carboxy/oxygenase (Rubisco large and small subunits, respectively, in cucumber leaves. However, 1-aminocyclopropane-1-carboxylate (ACC deaminase activity was undetected in none of the culture solutions of three BBS constituent strains. These results indicated that BBS conferred induced systemic tolerance to drought stress in cucumber plants, by protecting plant cells, maintaining photosynthetic efficiency and root vigor and increasing some of antioxidase activities, without involving the action of ACC deaminase to lower plant ethylene levels.

  1. Electronic modification of Pt via Ti and Se as tolerant cathodes in air-breathing methanol microfluidic fuel cells.

    Science.gov (United States)

    Ma, Jiwei; Habrioux, Aurélien; Morais, Cláudia; Alonso-Vante, Nicolas

    2014-07-21

    We reported herein on the use of tolerant cathode catalysts such as carbon supported Pt(x)Ti(y) and/or Pt(x)Se(y) nanomaterials in an air-breathing methanol microfluidic fuel cell. In order to show the improvement of mixed-reactant fuel cell (MRFC) performances obtained with the developed tolerant catalysts, a classical Pt/C nanomaterial was used for comparison. Using 5 M methanol concentration in a situation where the fuel crossover is 100% (MRFC-mixed reactant fuel cell application), the maximum power density of the fuel cell with a Pt/C cathodic catalyst decreased by 80% in comparison with what is observed in the laminar flow fuel cell (LFFC) configuration. With Pt(x)Ti(y)/C and Pt(x)Se(y)/C cathode nanomaterials, the performance loss was only 55% and 20%, respectively. The evaluation of the tolerant cathode catalysts in an air-breathing microfluidic fuel cell suggests the development of a novel nanometric system that will not be size restricted. These interesting results are the consequence of the high methanol tolerance of these advanced electrocatalysts via surface electronic modification of Pt. Herein we used X-ray photoelectron and in situ FTIR spectroscopies to investigate the origin of the high methanol tolerance on modified Pt catalysts.

  2. Alcohol-tolerant mutants of cyanobacterium Synechococcus elongatus PCC 7942 obtained by single-cell mutant screening system.

    Science.gov (United States)

    Arai, Sayuri; Hayashihara, Kayoko; Kanamoto, Yuki; Shimizu, Kazunori; Hirokawa, Yasutaka; Hanai, Taizo; Murakami, Akio; Honda, Hiroyuki

    2017-08-01

    Enhancement of alcohol tolerance in microorganisms is an important strategy for improving bioalcohol productivity. Although cyanobacteria can be used as a promising biocatalyst to produce various alcohols directly from CO 2 , low productivity, and low tolerance against alcohols are the main issues to be resolved. Nevertheless, to date, a mutant with increasing alcohol tolerance has rarely been reported. In this study, we attempted to select isopropanol (IPA)-tolerant mutants of Synechococcus elongatus PCC 7942 using UV-C-induced random mutagenesis, followed by enrichment of the tolerant candidates in medium containing 10 g/L IPA and screening of the cells with a high growth rate in the single cell culture system in liquid medium containing 10 g/L IPA. We successfully acquired the most tolerant strain, SY1043, which maintains the ability to grow in medium containing 30 g/L IPA. The photosynthetic oxygen-evolving activities of SY1043 were almost same in cells after 72 h incubation under light with or without 10 g/L IPA, while the activity of the wild-type was remarkably decreased after the incubation with IPA. SY1043 also showed higher tolerance to ethanol, 1-butanol, isobutanol, and 1-pentanol than the wild type. These results suggest that SY1043 would be a promising candidate to improve alcohol production using cyanobacteria. Biotechnol. Bioeng. 2017;114: 1771-1778. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  3. Gastritis promotes an activated bone marrow-derived mesenchymal stem cell with a phenotype reminiscent of a cancer-promoting cell.

    Science.gov (United States)

    Donnelly, Jessica M; Engevik, Amy C; Engevik, Melinda; Schumacher, Michael A; Xiao, Chang; Yang, Li; Worrell, Roger T; Zavros, Yana

    2014-03-01

    Bone marrow-derived mesenchymal stem cells (BM-MSCs) promote gastric cancer in response to gastritis. In culture, BM-MSCs are prone to mutation with continued passage but it is unknown whether a similar process occurs in vivo in response to gastritis. The purpose of this study was to identify the role of chronic gastritis in the transformation of BM-MSCs leading to an activated cancer-promoting phenotype. Age matched C57BL/6 (BL/6) and gastrin deficient (GKO) mice were used for isolation of stomach, serum and mesenchymal stem cells (MSCs) at 3 and 6 months of age. MSC activation was assessed by growth curve analysis, fluorescence-activated cell sorting and xenograft assays. To allow for the isolation of bone marrow-derived stromal cells and assay in response to chronic gastritis, IRG/Vav-1(Cre) mice that expressed both enhanced green fluorescent protein-expressing hematopoietic cells and red fluorescent protein-expressing stromal cells were generated. In a parabiosis experiment, IRG/Vav-1(Cre) mice were paired to either an uninfected Vav-1(Cre) littermate or a BL/6 mouse inoculated with Helicobacter pylori. GKO mice displayed severe atrophic gastritis accompanied by elevated gastric tissue and circulating transforming growth factor beta (TGFβ) by 3 months of age. Compared to BM-MSCs isolated from uninflamed BL/6 mice, BM-MSCs isolated from GKO mice displayed an increased proliferative rate and elevated phosphorylated-Smad3 suggesting active TGFβ signaling. In xenograft assays, mice injected with BM-MSCs from 6-month-old GKO animals displayed tumor growth. RFP+ stromal cells were rapidly recruited to the gastric mucosa of H. pylori parabionts and exhibited changes in gene expression. Gastritis promotes the in vivo activation of BM-MSCs to a phenotype reminiscent of a cancer-promoting cell.

  4. BAFF promotes regulatory T-cell apoptosis and blocks cytokine production by activating B cells in primary biliary cirrhosis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Bo; Hu, Mintao [Department of Hepatology, Wuxi Infectious Diseases Hospital, Wuxi, Jiangsu (China); Zhang, Peng [Nanjing Medical University, Nanjing, Jiangsu (China); Cao, Hong [Department of Hepatology, Wuxi Infectious Diseases Hospital, Wuxi, Jiangsu (China); Wang, Yongzhen [The Second Hospital of Nanjing, Nanjing, Jiangsu (China); Wang, Zheng; Su, Tingting [Department of Hepatology, Wuxi Infectious Diseases Hospital, Wuxi, Jiangsu (China)

    2013-05-10

    Primary biliary cirrhosis (PBC) is a chronic and slowly progressive cholestatic liver disease of autoimmune etiology. A number of questions regarding its etiology are unclear. CD4+CD25+ regulatory T cells (Tregs) play a critical role in self-tolerance and, for unknown reasons, their relative number is reduced in PBC patients. B-cell-activating factor (BAFF) is a key survival factor during B-cell maturation and its concentration is increased in peripheral blood of PBC patients. It has been reported that activated B cells inhibit Treg cell proliferation and there are no BAFF receptors on Tregs. Therefore, we speculated that excessive BAFF may result in Treg reduction via B cells. To prove our hypothesis, we isolated Tregs and B cells from PBC and healthy donors. BAFF and IgM concentrations were then analyzed by ELISA and CD40, CD80, CD86, IL-10, and TGF-β expression in B cells and Tregs were measured by flow cytometry. BAFF up-regulated CD40, CD80, CD86, and IgM expression in B cells. However, BAFF had no direct effect on Treg cell apoptosis and cytokine secretion. Nonetheless, we observed that BAFF-activated B cells could induce Treg cell apoptosis and reduce IL-10 and TGF-β expression. We also showed that BAFF-activated CD4+ T cells had no effect on Treg apoptosis. Furthermore, we verified that bezafibrate, a hypolipidemic drug, can inhibit BAFF-induced Treg cell apoptosis. In conclusion, BAFF promotes Treg cell apoptosis and inhibits cytokine production by activating B cells in PBC patients. The results of this study suggest that inhibition of BAFF activation is a strategy for PBC treatment.

  5. Isolation and characterization of an atypical LEA protein coding cDNA and its promoter from drought-tolerant plant Prosopis juliflora.

    Science.gov (United States)

    George, Suja; Usha, B; Parida, Ajay

    2009-05-01

    Plant growth and productivity are adversely affected by various abiotic and biotic stress factors. Despite the wealth of information on abiotic stress and stress tolerance in plants, many aspects still remain unclear. Prosopis juliflora is a hardy plant reported to be tolerant to drought, salinity, extremes of soil pH, and heavy metal stress. In this paper, we report the isolation and characterization of the complementary DNA clone for an atypical late embryogenesis abundant (LEA) protein (Pj LEA3) and its putative promoter sequence from P. juliflora. Unlike typical LEA proteins, rich in glycine, Pj LEA3 has alanine as the most abundant amino acid followed by serine and shows an average negative hydropathy. Pj LEA3 is significantly different from other LEA proteins in the NCBI database and shows high similarity to indole-3 acetic-acid-induced protein ARG2 from Vigna radiata. Northern analysis for Pj LEA3 in P. juliflora leaves under 90 mM H2O2 stress revealed up-regulation of transcript at 24 and 48 h. A 1.5-kb fragment upstream the 5' UTR of this gene (putative promoter) was isolated and analyzed in silico. The possible reasons for changes in gene expression during stress in relation to the host plant's stress tolerance mechanisms are discussed.

  6. Src Induces Podoplanin Expression to Promote Cell Migration*

    Science.gov (United States)

    Shen, Yongquan; Chen, Chen-Shan; Ichikawa, Hitoshi; Goldberg, Gary S.

    2010-01-01

    Nontransformed cells can force tumor cells to assume a normal morphology and phenotype by the process of contact normalization. Transformed cells must escape this process to become invasive and malignant. However, mechanisms underlying contact normalization have not been elucidated. Here, we have identified genes that are affected by contact normalization of Src-transformed cells. Tumor cells must migrate to become invasive and malignant. Src must phosphorylate the adaptor protein Cas (Crk-associated substrate) to promote tumor cell motility. We report here that Src utilizes Cas to induce podoplanin (Pdpn) expression to promote tumor cell migration. Pdpn is a membrane-bound extracellular glycoprotein that associates with endogenous ligands to promote tumor cell migration leading to cancer invasion and metastasis. In fact, Pdpn expression accounted for a major part of the increased migration seen in Src-transformed cells. Moreover, nontransformed cells suppressed Pdpn expression in adjacent Src-transformed cells. Of >39,000 genes, Pdpn was one of only 23 genes found to be induced by transforming Src activity and suppressed by contact normalization of Src-transformed cells. In addition, we found 16 genes suppressed by Src and induced by contact normalization. These genes encode growth factor receptors, adaptor proteins, and products that have not yet been annotated and may play important roles in tumor cell growth and migration. PMID:20123990

  7. Loss of CDKC;2 increases both cell division and drought tolerance in Arabidopsis thaliana.

    Science.gov (United States)

    Zhao, Lina; Li, Yaqiong; Xie, Qi; Wu, Yaorong

    2017-09-01

    Drought stress is one of the abiotic stresses that limit plant growth and agricultural productivity. To further understand the mechanism of drought tolerance and identify the genes involved in this process, a genetic screen for altered drought response was conducted in Arabidopsis. One mutant with enhanced drought tolerance was isolated and named Arabidopsis drought tolerance mutant 1 (atdtm1), which has larger lateral organs, prolonged growth duration, increased relative water content and a reduced leaf stomatal density compared with the wild type. The loss of AtDTM1 increases cell division during leaf development. The phenotype is caused by the loss of a T-DNA tagged gene encoding CYCLIN-DEPENDENT KINASE C;2 (CDKC;2), which functions in the regulation of transcription by influencing the phosphorylation status of RNA polymerase II (Pol II). Here, we show that CDKC;2 affects the transcription of downstream genes such as cell cycle genes and genes involved in stomatal development, resulting in altered plant organ size as well as drought tolerance of the plant. These results reveal the crucial role of CDKC;2 in modulating both cell division and the drought response in Arabidopsis. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  8. Suppressor cells in transplantation tolerance. III. The role of antigen in the maintenance of transplantation tolerance

    International Nuclear Information System (INIS)

    Tutschka, P.J.; Hess, A.D.; Beschorner, W.E.; Santos, G.W.

    1982-01-01

    Suppressor cells, which in an alloantigen-specific manner inhibit proliferation of donor cells to host antigens in a mixed lymphocyte culture and adoptively transfer the suppression of graft-versus-host disease (GVHD), undergo a gradual clonal reduction in long-term, allogeneic, histoincompatible rat radiation chimeras until they can no longer be measured in an in vitro suppressor cell assay. When lymphohematopoietic cells from these chimeras are transferred into lethally irradiated secondary recipients of original donor strain, the suppressor cells, now in a target antigen-free environment, undergo a further clonal reduction. After parking for 120 days, the chimeric cells are specifically tolerant to original host antigens, but cannot adoptively transfer suppression of GVHD. When chimeric cells, parked for 120 days in secondary recipients of original donor strain, are stimulated with original host-type antigen repeatedly during or once at the end of the parking period, the suppressor cell clone is expanded, suppressor cells can be identified in vitro, and suppression of GVHD can adoptively be transferred to tertiary recipients

  9. In Utero Exposure to Exosomal and B-Cell Alloantigens Lessens Alloreactivity of Recipients’ Lymphocytes Rather than Confers Allograft Tolerance

    Directory of Open Access Journals (Sweden)

    Jeng-Chang Chen

    2018-03-01

    Full Text Available According to actively acquired tolerance, antigen exposure before full immune development in fetal or early neonatal life will cause tolerance to this specific antigen. In this study, we aimed to examine whether allogeneic tolerance could be elicited by in utero exposure to surface MHC antigens of allogenic cells or soluble form of MHC exosomes. Gestational day 14 FVB/N fetuses were subjected to intraperitoneal injection of allogeneic major histocompatibility complex (MHC exosomes or highly enriched B-cells. Postnatally, the recipients were examined for the immune responses to donor alloantigens by lymphocyte proliferative reactions and skin transplantation. In utero exposure to allogeneic MHC exosomes abolished the alloreactivity of recipients’ lymphocytes to the alloantigens, but could not confer skin allograft tolerance. In utero transplantation of highly enriched allogeneic B-cells generated low-level B-cell chimerism in the recipients. However, it only extended the survivals of skin allograft by a few days despite the lack of donor-specific alloreactivity of recipients’ lymphocyte. Thus, an early in utero contact with exosomal or B-cell alloantigens did not lead to full skin tolerance but rather, at best, only to delayed skin rejection in the presence of microchimerism made by B-cell inocula. These results argued against the theory of actively acquired tolerance, and implicated that in utero exposure to marrow cells in previous studies was a unique model of allo-tolerance induction that involved the establishment of significant hematopoietic chimerism. Taken together with the discovery of in utero sensitization to ovalbumin in our previous studies, the immunological consequences of fetal exposure to foreign antigens might vary according to the type or nature of antigens introduced.

  10. In Utero Exposure to Exosomal and B-Cell Alloantigens Lessens Alloreactivity of Recipients' Lymphocytes Rather than Confers Allograft Tolerance.

    Science.gov (United States)

    Chen, Jeng-Chang; Ou, Liang-Shiou; Chan, Cheng-Chi; Kuo, Ming-Ling; Tseng, Li-Yun; Chang, Hsueh-Ling

    2018-01-01

    According to actively acquired tolerance, antigen exposure before full immune development in fetal or early neonatal life will cause tolerance to this specific antigen. In this study, we aimed to examine whether allogeneic tolerance could be elicited by in utero exposure to surface MHC antigens of allogenic cells or soluble form of MHC exosomes. Gestational day 14 FVB/N fetuses were subjected to intraperitoneal injection of allogeneic major histocompatibility complex (MHC) exosomes or highly enriched B-cells. Postnatally, the recipients were examined for the immune responses to donor alloantigens by lymphocyte proliferative reactions and skin transplantation. In utero exposure to allogeneic MHC exosomes abolished the alloreactivity of recipients' lymphocytes to the alloantigens, but could not confer skin allograft tolerance. In utero transplantation of highly enriched allogeneic B-cells generated low-level B-cell chimerism in the recipients. However, it only extended the survivals of skin allograft by a few days despite the lack of donor-specific alloreactivity of recipients' lymphocyte. Thus, an early in utero contact with exosomal or B-cell alloantigens did not lead to full skin tolerance but rather, at best, only to delayed skin rejection in the presence of microchimerism made by B-cell inocula. These results argued against the theory of actively acquired tolerance, and implicated that in utero exposure to marrow cells in previous studies was a unique model of allo-tolerance induction that involved the establishment of significant hematopoietic chimerism. Taken together with the discovery of in utero sensitization to ovalbumin in our previous studies, the immunological consequences of fetal exposure to foreign antigens might vary according to the type or nature of antigens introduced.

  11. Hematopoietic chimerism and transplantation tolerance: a role for regulatory T cells

    Directory of Open Access Journals (Sweden)

    Lise ePasquet

    2011-12-01

    Full Text Available The major obstacle in transplantation medicine is rejection of donor tissues by the host’s immune system. Immunosuppressive drugs can delay but not prevent loss of transplants, and their efficiency is strongly impacted by inter-individual pharmacokinetic differences. Moreover, due to the global immunosuppression induced and to the broad distribution of their targets amongst human tissues, these drugs have severe side effects. Induction of donor-specific non-responsiveness (i.e. immunological tolerance to transplants would solve these problems and would substantially ameliorate patients’ quality of life. It is widely believed that bone marrow or hematopoietic stem cell transplantation, and resulting (mixed hematopoietic chimerism, invariably leads to immunological tolerance to organs of the same donor. A careful analysis of the literature, reviewed here, indeed shows that chimerism consistently prolongs allograft survival. However, in absence of additional conditioning leading to the development of active regulatory mechanisms, it does not prevent chronic rejection. A central role for active tolerance in transplantation-tolerance is also supported by recent data showing that genuine immunological tolerance to organ allografts can be achieved by combining induction of hematopoietic chimerism with infusion of regulatory T lymphocytes. Therefore, conditioning regimens that lead to the establishment of hematopoietic chimerism plus active regulatory mechanisms appear required for induction of genuine tolerance to allogeneic grafts.

  12. The miR-599 promotes non-small cell lung cancer cell invasion via SATB2

    International Nuclear Information System (INIS)

    Tian, Wenjun; Wang, Guanghai; Liu, Yiqing; Huang, Zhenglan; Zhang, Caiqing; Ning, Kang; Yu, Cuixiang; Shen, Yajuan; Wang, Minghui; Li, Yuantang; Wang, Yong; Zhang, Bingchang; Zhao, Yaoran

    2017-01-01

    MicroRNAs (miRNAs) play important roles in the pathogenesis of many types of cancers by negatively regulating gene expression at posttranscriptional level. Here, we identified that miR-599 is up-regulated in non-small cell lung cancer (NSCLC) patients. It promoted NSCLC cell proliferation by negatively regulating SATB2. In NSCLC cell lines, CCK-8 proliferation assay indicated that the cell proliferation is promoted by miR-599 mimics. Transwell assay showed that miR-599 mimics promoted the invasion and migration of NSCLC cells. Luciferase assays confirmed that miR-599 directly binds to the 3'untranslated region of SATB2, and western blotting showed that miR-599 suppresses the expression of SATB2 at the protein level. This study indicates that miR-599 promotes proliferation and invasion of NSCLC cell lines via SATB2. The miR-599 may represent a potential therapeutic target for NSCLC treatment. - Highlights: • miR-599 is up-regulated in NSCLC. • miR-599 promotes the proliferation and invasion of NSCLC cells. • miR-599 inhibitors inhibits the proliferation and invasion of NSCLC cells. • miR-599 targets 3′ UTR of SATB2 in NSCLC cells. • miR-599 inhibits SATB2 in NSCLC cells.

  13. Suppressor cells in transplantation tolerance II. Maturation of suppressor cells in the bone marrow chimera

    International Nuclear Information System (INIS)

    Tutschka, P.J.; Ki, P.F.; Beschorner, W.E.; Hess, A.D.; Santos, G.W.

    1981-01-01

    Histoincompatible bone marrow allografts were established in lethally irradiated rats. At various times after transplantation, the spleen cells were harvested, subjected to mixed lymphocyte cultures, and assayed for suppressor cells in vitro and in vivo by adoptive transfer studies. Alloantigen-nonspecific suppressor cells appeared in the chimera at 40 days after grafting, coinciding with the resolution of graft-versus-host disease (GVHD). At 250 days the nonspecific suppressor cells were replaced by suppressor cells specifically suppressing donor-versus-host alloantigen responses. At 720 days suppressor cells could no longer be identified by in vitro methods but were identified by in vivo adoptive transfer of transplantation tolerance. After injection of host-type antigen into chimeras, the suppressor cells could be again demonstrated by in vitro methods

  14. Suppressor cells in transplantation tolerance. II. maturation of suppressor cells in the bone marrow chimera

    International Nuclear Information System (INIS)

    Tutschka, P.J.; Ki, P.F.; Beschorner, W.E.; Hess, A.D.; Santos, G.W.

    1981-01-01

    Histoincompatible bone marrow allografts were established in lethally irradiated rats. At various times after transplantation, the spleen cells were harvested, subjected to mixed lymphocyte cultures, and assayed for suppressor cells in vitro and in vivo by adoptive transfer studies. Alloantigen-nonspecific suppressor cells appeared in the chimera at 40 days after grafting, coinciding with the resolution of graft-versus-host disease (GVHD). At 250 days the nonspecific suppressor cells were replaced by suppressor cells specifically suppressing donor-versus-host alloantigen responses. At 720 days suppressor cells could no longer be identified by in vitro methods but were identified by in vivo adoptive transfer of transplantation tolerance. After injection of host-type antigen into chimeras, the suppressor cells could be again demonstrated by in vitro methods

  15. Urbanism, Migration, and Tolerance: A Reassessment.

    Science.gov (United States)

    Wilson, Thomas C.

    1991-01-01

    Urbanism's impact on the personality may be stronger than previously thought. Finds that urban residence has a strong positive effect on tolerance. Migration also promotes tolerance, regardless of the size of the destination community. (DM)

  16. Insulin resistance according to β-cell function in women with polycystic ovary syndrome and normal glucose tolerance.

    Science.gov (United States)

    Song, Do Kyeong; Hong, Young Sun; Sung, Yeon-Ah; Lee, Hyejin

    2017-01-01

    Polycystic ovary syndrome (PCOS) is associated with insulin resistance (IR) and compensatory hyperinsulinemia. IR is recognized as a major risk factor for the development of type 2 diabetes mellitus. However, few studies have investigated IR in women with PCOS and normal glucose tolerance. The objective of this study was to evaluate IR and β-cell function in women with PCOS and normal glucose tolerance. Additionally, we sought to evaluate the usefulness of oral glucose tolerance test (OGTT)-derived IR indices in lean women with PCOS. We recruited 100 women with PCOS and normal glucose tolerance and 100 age- and BMI-matched women as controls. IR and insulin secretory indices, including the homeostasis-model assessment (HOMA)-IR, HOMA-M120, HOMA-F and the Stumvoll index, were calculated from an OGTT. Increased β-cell function was defined as>75th percentile for the HOMA-F in control women. Women with PCOS had higher values for post-load 2-hour glucose, fasting insulin, post-load 2-hour insulin, HOMA-IR, HOMA-M120, HOMA-F and lower values for the Stumvoll index than the controls (all PsWomen with PCOS and increased β-cell function showed lower Stumvoll index values than the matched controls (Plean women with PCOS (all PsWomen with PCOS and normal glucose tolerance showed higher IR than controls matched for age, BMI, and β-cell function. β-cell function was increased in women with PCOS when compared to the matched controls, but not when the lean subjects were compared to the matched controls separately. Therefore, early evaluation of IR in women with PCOS and normal glucose tolerance may be needed.

  17. Infectious Tolerance

    Science.gov (United States)

    Jonuleit, Helmut; Schmitt, Edgar; Kakirman, Hacer; Stassen, Michael; Knop, Jürgen; Enk, Alexander H.

    2002-01-01

    Regulatory CD4+CD25+ T cells (Treg) are mandatory for maintaining immunologic self-tolerance. We demonstrate that the cell-cell contact–mediated suppression of conventional CD4+ T cells by human CD25+ Treg cells is fixation resistant, independent from membrane-bound TGF-β but requires activation and protein synthesis of CD25+ Treg cells. Coactivation of CD25+ Treg cells with Treg cell–depleted CD4+ T cells results in anergized CD4+ T cells that in turn inhibit the activation of conventional, freshly isolated CD4+ T helper (Th) cells. This infectious suppressive activity, transferred from CD25+ Treg cells via cell contact, is cell contact–independent and partially mediated by soluble transforming growth factor (TGF)-β. The induction of suppressive properties in conventional CD4+ Th cells represents a mechanism underlying the phenomenon of infectious tolerance. This explains previously published conflicting data on the role of TGF-β in CD25+ Treg cell–induced immunosuppression. PMID:12119350

  18. Regulatory focus affects physician risk tolerance.

    Science.gov (United States)

    Veazie, Peter J; McIntosh, Scott; Chapman, Benjamin P; Dolan, James G

    2014-01-01

    Risk tolerance is a source of variation in physician decision-making. This variation, if independent of clinical concerns, can result in mistaken utilization of health services. To address such problems, it will be helpful to identify nonclinical factors of risk tolerance, particularly those amendable to intervention-regulatory focus theory suggests such a factor. This study tested whether regulatory focus affects risk tolerance among primary care physicians. Twenty-seven primary care physicians were assigned to promotion-focused or prevention-focused manipulations and compared on the Risk Taking Attitudes in Medical Decision Making scale using a randomization test. Results provide evidence that physicians assigned to the promotion-focus manipulation adopted an attitude of greater risk tolerance than the physicians assigned to the prevention-focused manipulation (p = 0.01). The Cohen's d statistic was conventionally large at 0.92. Results imply that situational regulatory focus in primary care physicians affects risk tolerance and may thereby be a nonclinical source of practice variation. Results also provide marginal evidence that chronic regulatory focus is associated with risk tolerance (p = 0.05), but the mechanism remains unclear. Research and intervention targeting physician risk tolerance may benefit by considering situational regulatory focus as an explanatory factor.

  19. Persistence of antigen is required to maintain transplantation tolerance induced by genetic modification of bone marrow stem cells.

    Science.gov (United States)

    Tian, C; Bagley, J; Iacomini, J

    2006-09-01

    Genetic modification of hematopoietic stem cells (HSCs) resulting in a state of molecular chimerism can be used to induce donor-specific tolerance to allografts. However, the requirements for maintaining tolerance in molecular chimeras remain unknown. Here, we examined whether long-term expression of a retrovirally encoded alloantigen in hematopoietic cells is required to maintain donor-specific tolerance in molecular chimeras. To this end, mice were reconstituted with syngeneic bone marrow transduced with retroviruses carrying the gene encoding the allogeneic MHC class I molecule Kb. Following induction of molecular chimerism, mice were depleted of cells expressing Kb by administration of the anti-Kb monoclonal antibody Y-3. Mice that were effectively depleted of cells expressing the retrovirally encoded MHC class I antigen rejected Kb disparate skin allografts. In contrast, control molecular chimeras accepted Kb disparate skin allografts indefinitely. These data suggest maintenance of tolerance in molecular chimeras requires long-term expression of retrovirally transduced alloantigen on the progeny of retrovirally transduced HSCs.

  20. Tolerance of transgenic canola plants (Brassica napus) amended with plant growth-promoting bacteria to flooding stress at a metal-contaminated field site

    International Nuclear Information System (INIS)

    Farwell, Andrea J.; Vesely, Susanne; Nero, Vincent; Rodriguez, Hilda; McCormack, Kimberley; Shah, Saleh; Dixon, D. George; Glick, Bernard R.

    2007-01-01

    The growth of transgenic canola (Brassica napus) expressing a gene for the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase was compared to non-transformed canola exposed to flooding and elevated soil Ni concentration, in situ. In addition, the ability of the plant growth-promoting bacterium Pseudomonas putida UW4, which also expresses ACC deaminase, to facilitate the growth of non-transformed and transgenic canola under the above mentioned conditions was examined. Transgenic canola and/or canola treated with P. putida UW4 had greater shoot biomass compared to non-transformed canola under low flood-stress conditions. Under high flood-stress conditions, shoot biomass was reduced and Ni accumulation was increased in all instances relative to low flood-stress conditions. This is the first field study to document the increase in plant tolerance utilizing transgenic plants and plant growth-promoting bacteria exposed to multiple stressors. - Using transgenic plants and plant growth-promoting bacteria as phytoremediation methods increased plant tolerance at a metal-contaminated field site under low flood conditions

  1. Polyclonal Recipient nTregs Are Superior to Donor or Third-Party Tregs in the Induction of Transplantation Tolerance

    Directory of Open Access Journals (Sweden)

    Nina Pilat

    2015-01-01

    Full Text Available Induction of donor-specific tolerance is still considered as the “Holy Grail” in transplantation medicine. The mixed chimerism approach is virtually the only tolerance approach that was successfully translated into the clinical setting. We have previously reported successful induction of chimerism and tolerance using cell therapy with recipient T regulatory cells (Tregs to avoid cytotoxic recipient treatment. Treg therapy is limited by the availability of cells as large-scale expansion is time-consuming and associated with the risk of contamination with effector cells. Using a costimulation-blockade based bone marrow (BM transplantation (BMT model with Treg therapy instead of cytoreductive recipient treatment we aimed to determine the most potent Treg population for clinical translation. Here we show that CD4+CD25+ in vitro activated nTregs are superior to TGFβ induced iTregs in promoting the induction of chimerism and tolerance. Therapy with nTregs (but not iTregs led to multilineage chimerism and donor-specific tolerance in mice receiving as few as 0.5 × 106 cells. Moreover, we show that only recipient Tregs, but not donor or third-party Tregs, had a beneficial effect on BM engraftment at the tested doses. Thus, recipient-type nTregs significantly improve chimerism and tolerance and might be the most potent Treg population for translation into the clinical setting.

  2. Targeted delivery of antigen to intestinal dendritic cells induces oral tolerance and prevents autoimmune diabetes in NOD mice.

    Science.gov (United States)

    Chen, Yulin; Wu, Jie; Wang, Jiajia; Zhang, Wenjing; Xu, Bohui; Xu, Xiaojun; Zong, Li

    2018-03-15

    The intestinal immune system is an ideal target to induce immune tolerance physiologically. However, the efficiency of oral protein antigen delivery is limited by degradation of the antigen in the gastrointestinal tract and poor uptake by antigen-presenting cells. Gut dendritic cells (DCs) are professional antigen-presenting cells that are prone to inducing antigen-specific immune tolerance. In this study, we delivered the antigen heat shock protein 65-6×P277 (H6P) directly to the gut DCs of NOD mice through oral vaccination with H6P-loaded targeting nanoparticles (NPs), and investigated the ability of this antigen to induce immune tolerance to prevent autoimmune diabetes in NOD mice. A targeting NP delivery system was developed to encapsulate H6P, and the ability of this system to protect and facilitate H6P delivery to gut DCs was assessed. NOD mice were immunised with H6P-loaded targeting NPs orally once a week for 7 weeks and the onset of diabetes was assessed by monitoring blood glucose levels. H6P-loaded targeting NPs protected the encapsulated H6P from degradation in the gastrointestinal tract environment and significantly increased the uptake of H6P by DCs in the gut Peyer's patches (4.1 times higher uptake compared with the control H6P solution group). Oral vaccination with H6P-loaded targeting NPs induced antigen-specific T cell tolerance and prevented diabetes in 100% of NOD mice. Immune deviation (T helper [Th]1 to Th2) and CD4 + CD25 + FOXP3 + regulatory T cells were found to participate in the induction of immune tolerance. In this study, we successfully induced antigen-specific T cell tolerance and prevented the onset of diabetes in NOD mice. To our knowledge, this is the first attempt at delivering antigen to gut DCs using targeting NPs to induce T cell tolerance.

  3. Trehalose improves cell proliferation and dehydration tolerance of human HaCaT cells

    Directory of Open Access Journals (Sweden)

    Lee Kyung Eun

    2015-01-01

    Full Text Available Trehalose is a disaccharide molecule that serves as a natural osmotic regulator in halophilic microorganisms and plants but not in mammals. We observed that human HaCaT cells supplied with trehalose improved cell proliferation and extended viability under dehydration. In HaCaT cells, in response to increasing concentrations of exogenous trehalose, the levels of heat shock protein (HSP 70 increased and matrix metalloproteinase (MMP 1 decreased. Proteome analysis of trehalose-treated HaCaT cells revealed remarkable increases in the levels of proteins involved in cell signaling and the cell cycle, including p21 activated kinase I, Sec I family domain protein and elongation factor G. Moreover, the proteins for cell stress resistance, tryptophan hydroxylase, serine/cysteine proteinase inhibitors and vitamin D receptors were also increased. In addition, the proteins responsible for the maintenance of the cytoskeleton and cellular structures including procollagen-lysine dioxygenase, vinculin and ezrin were increased. Proteomic data revealed that trehalose affected HaCaT cells by inducing the proteins involved in cell proliferation. These results suggest that trehalose improves the proliferation and dehydration tolerance of HaCaT cells by inducing proteins involved in cell growth and dehydration protection.

  4. Studies on the termination of immunological tolerance in the mouse thymus cell population after irradiation

    International Nuclear Information System (INIS)

    Amagai, Takashi

    1981-01-01

    Immunological tolerance in the mouse thymus cell population induced by the intravenous injection of deaggregated bovine gamma globulin was terminated by whole body irradiation. After irradiation, the weight of the thymus recovered biphasically, and the termination of tolerance occurred as early as in the first phase. Both Thy-1 antigen expression and helper activity of the thymus cell population in irradiated mice recovered in parallel with the recovery of the thymus weight. Sensitivity of the regenerating thymus cells to the tolerogen was not different from that of the normal thymus cells. The first phase of thymus regeneration may be caused by the proliferation and differentiation of relatively radioresistant and tolerogen insensitive precursors residing in the thymus. Tolerogen and/or immunogen reactive thymus cells may originate from the precursor. (author)

  5. Promoter DNA hypermethylation and gene repression in undifferentiated Arabidopsis cells.

    Directory of Open Access Journals (Sweden)

    María Berdasco

    Full Text Available Maintaining and acquiring the pluripotent cell state in plants is critical to tissue regeneration and vegetative multiplication. Histone-based epigenetic mechanisms are important for regulating this undifferentiated state. Here we report the use of genetic and pharmacological experimental approaches to show that Arabidopsis cell suspensions and calluses specifically repress some genes as a result of promoter DNA hypermethylation. We found that promoters of the MAPK12, GSTU10 and BXL1 genes become hypermethylated in callus cells and that hypermethylation also affects the TTG1, GSTF5, SUVH8, fimbrin and CCD7 genes in cell suspensions. Promoter hypermethylation in undifferentiated cells was associated with histone hypoacetylation and primarily occurred at CpG sites. Accordingly, we found that the process specifically depends on MET1 and DRM2 methyltransferases, as demonstrated with DNA methyltransferase mutants. Our results suggest that promoter DNA methylation may be another important epigenetic mechanism for the establishment and/or maintenance of the undifferentiated state in plant cells.

  6. Development of an air bleeding technique and specific duration to improve the CO tolerance of proton-exchange membrane fuel cells

    International Nuclear Information System (INIS)

    Chung, Chen-Chung; Chen, Chiun-Hsun; Weng, De-Zheng

    2009-01-01

    This study investigated transient CO poisoning of a proton-exchange membrane fuel cell under either a fixed cell voltage or fixed current density. During CO poisoning tests, the cell performance decreases over time. Experiments were performed to identify which method yields better performance in CO poisoning tests. The results revealed that a change in cell voltage did not affect the stable polarization behavior after CO poisoning of the cell. On the other hand, a higher fixed current density yielded better tolerance of 52.7 ppm CO. The air bleeding technique was then applied using different timings for air introduction during CO poisoning tests. Air bleeding significantly improved the CO tolerance of the cell and recovered the performance after poisoning, regardless of the timing of air introduction. The effects of different anode catalyst materials on cell performance were also investigated during poisoning tests. Without air bleeding, a Pt-Ru alloy catalyst exhibited better CO tolerance than a pure Pt catalyst. However, the air bleeding technique can effectively increase the CO tolerance of cells regardless of the type of catalyst used.

  7. Selection of efficient salt-tolerant bacteria containing ACC deaminase for promotion of tomato growth under salinity stress

    Directory of Open Access Journals (Sweden)

    Kannika Chookietwattana* and Kedsukon Maneewan

    2012-05-01

    Full Text Available For successful application of plant growth promoting bacteria (PGPB in salt-affected soil, bioinoculant with salt-tolerant property is required in order to provide better survival and perform well in the field. The present study aimed to select the most efficient salt-tolerant bacterium containing 1-aminocyclopropane-1-carboxylic acid (ACC deaminase from eighty four bacterial strains and to investigate the effects of the selected bacterium on the germination and growth of tomato (Licopersicon esculentum Mill. cv. Seeda under saline conditions. The Bacillus licheniformis B2r was selected for its ability to utilize ACC as a sole nitrogen source under salinity stress. It also showed a high ACC deaminase activity at 0.6 M NaCl salinity. Tomato plants inoculated with the selected bacterium under various saline conditions (0, 30, 60, 90 and 120 mM NaCl revealed a significant increase in the germination percentage, germination index, root length, and seedling dry weight especially at salinity levels ranging from 30-90 mM NaCl. The work described in this report is an important step in developing an efficient salt-tolerant bioinoculant to facilitate plant growth in saline soil.

  8. CNPY2 promoted the proliferation of renal cell carcinoma cells and increased the expression of TP53

    International Nuclear Information System (INIS)

    Taniguchi, Hidefumi; Ito, Saya; Ueda, Takashi; Morioka, Yukako; Kayukawa, Naruhiro; Ueno, Akihisa; Nakagawa, Hideo; Fujihara, Atsuko; Ushijima, So; Kanazawa, Motohiro; Hongo, Fumiya; Ukimura, Osamu

    2017-01-01

    Renal cell carcinoma (RCC) is the most common type of kidney cancer. However, the mechanisms underlying the progression of the disease are not well understood. The data in this report suggest that canopy FGF signaling regulator 2 (CNPY2) is a promoter of RCC progression. We found that CNPY2 significantly promoted growth of RCC cells and upregulated TP53 gene expression. Although TP53 is widely known as a tumor suppressor, in RCC TP53 promoted tumor cell growth. A typical p53 target gene, CDKN1A, was upregulated by both p53 and CNPY2 in RCC cells, suggesting that CNPY2 increased the expression level of TP53. Consistent with these results, CNPY2 and TP53 expression levels were positively correlated in RCC patients. These findings suggested that CNPY2 promoted cancer cell growth in RCC through regulating TP53 gene expression. - Highlights: • CNPY2 promoted growth of renal cell carcinoma (RCC) cells. • TP53 expression levels were increased by CNPY2 in RCC cells. • Growth of RCC cells was promoted by TP53. • CNPY2 expression positively correlated with TP53 expression in RCC patients.

  9. Evidence against suppressor cell involvement in naturally acquired tolerance of a minor histocompatibility antigen

    International Nuclear Information System (INIS)

    Johnson, L.L.

    1991-01-01

    The hypothesis was investigated that suppressor cells may be responsible for maintenance of immunologic tolerance of a minor H3 antigen in mice that express the antigen naturally. Lymphoid cell populations from B6.C-H-24c (HW54) mice, a congenic-resistant strain histoincompatible with H-24b-expressing C57BL/6 (B6) mice only with respect to the H-24 locus, were examined in cell-transfer experiments to see if they contained naturally arising H-24c-specific suppressor cells. The H-24 antigen was chosen for these studies because, unlike most other minor and major histocompatibility (H) antigens, it is not detectable on mature lymphoid cells by any of several functional criteria. Thus transfer of HW54 lymphoid cells to B6 hosts could be done without the complication of inducing hyporesponsiveness de novo in the host, as occurs with other minor H antigens that are expressed on lymphocytes. B6 hosts were given HW54 skin grafts along with HW54 lymphoid cells to assess their tolerance of the H-24c-encoded antigen. The hosts were either (1) normal, nonimmune B6 mice; (2) B6 mice rendered immunodeficient by thymectomy and irradiation (TxB) and repopulated with H-24c-immune B6 lymphocytes; or (3) TxB B6 hosts repopulated with nonimmune B6 lymphocytes. In each case it was found that the additionally infused HW54 lymphoid cells did not suppress the ability of these hosts to reject HW54 skin grafts. In other words, HW54 lymphoid cells appear not to possess suppressive activity specific for the H-24c antigen that might maintain antigen-specific natural tolerance. Additional experiments were performed to determine whether HW54 lymphoid cells can inhibit the ability of sublethally irradiated B6 mice to regain the capacity to reject HW54 skin

  10. Differential DNA methylation patterns define status epilepticus and epileptic tolerance.

    Science.gov (United States)

    Miller-Delaney, Suzanne F C; Das, Sudipto; Sano, Takanori; Jimenez-Mateos, Eva M; Bryan, Kenneth; Buckley, Patrick G; Stallings, Raymond L; Henshall, David C

    2012-02-01

    Prolonged seizures (status epilepticus) produce pathophysiological changes in the hippocampus that are associated with large-scale, wide-ranging changes in gene expression. Epileptic tolerance is an endogenous program of cell protection that can be activated in the brain by previous exposure to a non-harmful seizure episode before status epilepticus. A major transcriptional feature of tolerance is gene downregulation. Here, through methylation analysis of 34,143 discrete loci representing all annotated CpG islands and promoter regions in the mouse genome, we report the genome-wide DNA methylation changes in the hippocampus after status epilepticus and epileptic tolerance in adult mice. A total of 321 genes showed altered DNA methylation after status epilepticus alone or status epilepticus that followed seizure preconditioning, with >90% of the promoters of these genes undergoing hypomethylation. These profiles included genes not previously associated with epilepsy, such as the polycomb gene Phc2. Differential methylation events generally occurred throughout the genome without bias for a particular chromosomal region, with the exception of a small region of chromosome 4, which was significantly overrepresented with genes hypomethylated after status epilepticus. Surprisingly, only few genes displayed differential hypermethylation in epileptic tolerance. Nevertheless, gene ontology analysis emphasized the majority of differential methylation events between the groups occurred in genes associated with nuclear functions, such as DNA binding and transcriptional regulation. The present study reports select, genome-wide DNA methylation changes after status epilepticus and in epileptic tolerance, which may contribute to regulating the gene expression environment of the seizure-damaged hippocampus.

  11. Reciprocal modulation of mesenchymal stem cells and tumor cells promotes lung cancer metastasis

    Directory of Open Access Journals (Sweden)

    Giulia Fregni

    2018-03-01

    Full Text Available Metastasis is a multi-step process in which direct crosstalk between cancer cells and their microenvironment plays a key role. Here, we assessed the effect of paired tumor-associated and normal lung tissue mesenchymal stem cells (MSCs on the growth and dissemination of primary human lung carcinoma cells isolated from the same patients. We show that the tumor microenvironment modulates MSC gene expression and identify a four-gene MSC signature that is functionally implicated in promoting metastasis. We also demonstrate that tumor-associated MSCs induce the expression of genes associated with an aggressive phenotype in primary lung cancer cells and selectively promote their dissemination rather than local growth. Our observations provide insight into mechanisms by which the stroma promotes lung cancer metastasis. Keywords: Tumor-associated MSCs, lung cancer, metastasis, GREM1, LOXL2, ADAMTS12, ITGA11

  12. Promoter of CaZF, a chickpea gene that positively regulates growth and stress tolerance, is activated by an AP2-family transcription factor CAP2.

    Directory of Open Access Journals (Sweden)

    Deepti Jain

    Full Text Available Plants respond to different forms of stresses by inducing transcription of a common and distinct set of genes by concerted actions of a cascade of transcription regulators. We previously reported that a gene, CaZF encoding a C2H2-zinc finger family protein from chickpea (Cicer arietinum imparted high salinity tolerance when expressed in tobacco plants. We report here that in addition to promoting tolerance against dehydration, salinity and high temperature, the CaZF overexpressing plants exhibited similar phenotype of growth and development like the plants overexpressing CAP2, encoding an AP2-family transcription factor from chickpea. To investigate any relationship between these two genes, we performed gene expression analysis in the overexpressing plants, promoter-reporter analysis and chromatin immunoprecipitation. A number of transcripts that exhibited enhanced accumulation upon expression of CAP2 or CaZF in tobacco plants were found common. Transient expression of CAP2 in chickpea leaves resulted in increased accumulation of CaZF transcript. Gel mobility shift and transient promoter-reporter assays suggested that CAP2 activates CaZF promoter by interacting with C-repeat elements (CRTs in CaZF promoter. Chromatin immunoprecipitation (ChIP assay demonstrated an in vivo interaction of CAP2 protein with CaZF promoter.

  13. Use of hematopoietic cell transplants to achieve tolerance in patients with solid organ transplants

    OpenAIRE

    Strober, Samuel

    2016-01-01

    The goals of tolerance in patients with solid organ transplants are to eliminate the lifelong need for immunosuppressive (IS) drugs and to prevent graft loss due to rejection or drug toxicity. Tolerance with complete withdrawal of IS drugs has been achieved in recipients of HLA-matched and mismatched living donor kidney transplants in 3 medical centers using hematopoietic cell transplants to establish mixed or complete chimerism.

  14. Angiotensin II type 1 receptor blockers increase tolerance of cells to copper and cisplatin

    Directory of Open Access Journals (Sweden)

    Pieter Spincemaille

    2014-10-01

    Full Text Available The human pathology Wilson disease (WD is characterized by toxic copper (Cu accumulation in brain and liver, resulting in, among other indications, mitochondrial dysfunction and apoptosis of hepatocytes. In an effort to identify novel compounds that can alleviate Cu-induced toxicity, we screened the Pharmakon 1600 repositioning library using a Cu-toxicity yeast screen. We identified 2 members of the drug class of Angiotensin II Type 1 receptor blockers (ARBs that could increase yeast tolerance to Cu, namely Candesartan and Losartan. Subsequently, we show that specific ARBs can increase yeast tolerance to Cu and/or the chemotherapeutic agent cisplatin (Cp. The latter also induces mitochondrial dysfunction and apoptosis in mammalian cells. We further demonstrate that specific ARBs can prevent the prevalence of Cu-induced apoptotic markers in yeast, with Candesartan Cilexetil being the ARB which demonstrated most pronounced reduction of apoptosis-related markers. Next, we tested the sensitivity of a selection of yeast knockout mutants affected in detoxification of reactive oxygen species (ROS and Cu for Candesartan Cilexetil rescue in presence of Cu. These data indicate that Candesartan Cilexetil increases yeast tolerance to Cu irrespectively of major ROS-detoxifying proteins. Finally, we show that specific ARBs can increase mammalian cell tolerance to Cu, as well as decrease the prevalence of Cu-induced apoptotic markers. All the above point to the potential of ARBs in preventing Cu-induced toxicity in yeast and mammalian cells.

  15. A Dominant-Negative PPARγ Mutant Promotes Cell Cycle Progression and Cell Growth in Vascular Smooth Muscle Cells

    Directory of Open Access Journals (Sweden)

    Joey Z. Liu

    2009-01-01

    Full Text Available PPARγ ligands have been shown to have antiproliferative effects on many cell types. We herein report that a synthetic dominant-negative (DN PPARγ mutant functions like a growth factor to promote cell cycle progression and cell proliferation in human coronary artery smooth muscle cells (CASMCs. In quiescent CASMCs, adenovirus-expressed DN-PPARγ promoted G1→S cell cycle progression, enhanced BrdU incorporation, and increased cell proliferation. DN-PPARγ expression also markedly enhanced positive regulators of the cell cycle, increasing Rb and CDC2 phosphorylation and the expression of cyclin A, B1, D1, and MCM7. Conversely, overexpression of wild-type (WT or constitutively-active (CA PPARγ inhibited cell cycle progression and the activity and expression of positive regulators of the cell cycle. DN-PPARγ expression, however, did not up-regulate positive cell cycle regulators in PPARγ-deficient cells, strongly suggesting that DN-PPARγ effects on cell cycle result from blocking the function of endogenous wild-type PPARγ. DN-PPARγ expression enhanced phosphorylation of ERK MAPKs. Furthermore, the ERK specific-inhibitor PD98059 blocked DN-PPARγ-induced phosphorylation of Rb and expression of cyclin A and MCM7. Our data thus suggest that DN-PPARγ promotes cell cycle progression and cell growth in CASMCs by modulating fundamental cell cycle regulatory proteins and MAPK mitogenic signaling pathways in vascular smooth muscle cells (VSMCs.

  16. Tolerance without clonal expansion: self-antigen-expressing B cells program self-reactive T cells for future deletion.

    Science.gov (United States)

    Frommer, Friederike; Heinen, Tobias J A J; Wunderlich, F Thomas; Yogev, Nir; Buch, Thorsten; Roers, Axel; Bettelli, Estelle; Müller, Werner; Anderton, Stephen M; Waisman, Ari

    2008-10-15

    B cells have been shown in various animal models to induce immunological tolerance leading to reduced immune responses and protection from autoimmunity. We show that interaction of B cells with naive T cells results in T cell triggering accompanied by the expression of negative costimulatory molecules such as PD-1, CTLA-4, B and T lymphocyte attenuator, and CD5. Following interaction with B cells, T cells were not induced to proliferate, in a process that was dependent on their expression of PD-1 and CTLA-4, but not CD5. In contrast, the T cells became sensitive to Ag-induced cell death. Our results demonstrate that B cells participate in the homeostasis of the immune system by ablation of conventional self-reactive T cells.

  17. H2A/K pseudogene mutation may promote cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Jisheng; Jing, Ruirui; Lv, Xin; Wang, Xiaoyue; Li, Junqiang; Li, Lin; Li, Cuiling; Wang, Daoguang; Bi, Baibing; Chen, Xinjun [Cancer Research Center, Shandong University School of Medicine, Jinan 250012 (China); Yang, Jing-Hua, E-mail: sdu_crc_group1@126.com [Cancer Research Center, Shandong University School of Medicine, Jinan 250012 (China); Department of Surgery, VA Boston Healthcare System, Boston University School of Medicine, Boston 510660, MA (United States)

    2016-05-15

    Highlights: • The mutant H2A/K pseudogene is active. • The mutant H2A/K pseudogene can promote cell proliferation. - Abstract: Little attention has been paid to the histone H2A/K pseudogene. Results from our laboratory showed that 7 of 10 kidney cancer patients carried a mutant H2A/K pseudogene; therefore, we were interested in determining the relationship between mutant H2A/K and cell proliferation. We used shotgun and label-free proteomics methods to study whether mutant H2A/K lncRNAs affected cell proliferation. Quantitative proteomic analysis indicated that the expression of mutant H2A/K lncRNAs resulted in the upregulation of many oncogenes, which promoted cell proliferation. Further interaction analyses revealed that a proliferating cell nuclear antigen (PCNA)-protein interaction network, with PCNA in the center, contributes to cell proliferation in cells expressing the mutant H2A/K lncRNAs. Western blotting confirmed the critical upregulation of PCNA by mutant H2A/K lncRNA expression. Finally, the promotion of cell proliferation by mutant H2A/K lncRNAs (C290T, C228A and A45G) was confirmed using cell proliferation assays. Although we did not determine the exact mechanism by which the oncogenes were upregulated by the mutant H2A/K lncRNAs, we confirmed that the mutant H2A/K lncRNAs promoted cell proliferation by upregulating PCNA and other oncogenes. The hypothesis that cell proliferation is promoted by the mutant H2A/K lncRNAs was supported by the protein expression and cell proliferation assay results. Therefore, mutant H2A/K lncRNAs may be a new factor in renal carcinogenesis.

  18. Space-environmental tolerances in a cyanobacterium, Nostoc sp. HK-01

    Science.gov (United States)

    Tomita-Yokotani, Kaori; Yokobori, Shin-ichi; Kimura, Shunta; Sato, Seigo; Katoh, Hiroshi; Ajioka, Reiko; Yamagishi, Akihiko; Inoue, Kotomi

    2016-07-01

    We have been investigating the tolerances to space-environments of a cyanobacterium, Nostoc sp. HK-01 (hereafter referred to as HK-01). Dry colonies of HK-01 had high tolerance to dry conditions, but more detailed information about tolerance to high-temperature, UV, gamma-ray and heavy particle beams were not deeply investigated. The obtained dry colonies of HK-01 after exposure to each of the conditions described above were investigated. In all of the tested colonies of HK-01 after exposure, all or some of the cells in the colonies were alive. One of the purposes of space agriculture is growing plants on Mars. In the early stages, of our research, cyanobacteria are introduced on Mars to promote the oxidation of the atmosphere and the formation of soil from Mars's regolith. HK-01 will contribute to each of these factors in the future.

  19. Deficiency of autoimmune regulator impairs the immune tolerance effect of bone marrow-derived dendritic cells in mice.

    Science.gov (United States)

    Huo, Feifei; Li, Dongbei; Zhao, Bo; Luo, Yadong; Zhao, Bingjie; Zou, Xueyang; Li, Yi; Yang, Wei

    2018-02-01

    As a transcription factor, autoimmune regulator (Aire) participates in thymic negative selection and maintains immune tolerance mainly by regulating the ectopic expression of tissue-restricted antigens (TRAs) in medullary thymic epithelial cells (mTECs). Aire is also expressed in dendritic cells (DCs). DCs are professional antigen-presenting cells (APCs) that affect the differentiation of T cells toward distinct subpopulations and participate in the immune response and tolerance, thereby playing an important role in maintaining homeostasis. To determine the role of Aire in maintaining immune tolerance by bone marrow-derived dendritic cells (BMDCs), in the present study we utilized Aire-knockout mice to examine the changes of maturation status and TRAs expression on BMDCs, additionally investigate the differentiation of CD4 + T cells. The results showed that expression of costimulatory molecule and major histocompatibility complex class II (MHC-II) molecule was increased and expression of various TRAs was decreased in BMDCs from Aire-knockout mice. Aire deficiency reduced the differentiation of naïve CD4 + T cells into type 2T helper (Th2) cells and regulatory T cells (Tregs) but enhanced the differentiation of naïve CD4 + T cells into Th1 cells, Th17 cells, and follicular helper T (Tfh) cells. The results demonstrate that Aire expressed by BMDCs plays an important role in the maintenance of homeostasis by regulating TRA expression and the differentiation of T cell subsets.

  20. A common polymorphism in the promoter of the IGF-I gene associates with increased fasting serum triglyceride levels in glucose-tolerant subjects

    DEFF Research Database (Denmark)

    Nielsen, Eva-Maria D; Hansen, Lars; Lajer, Maria

    2004-01-01

    The aim of the present study was to examine if absence of a common allele in a microsatellite polymorphism in the insulin-like growth factor I (IGF-I) promoter was associated with type 2 diabetes and alterations in quantitative traits in glucose-tolerant subjects....

  1. Cancer cell specific cytotoxic gene expression mediated by ARF tumor suppressor promoter constructs

    International Nuclear Information System (INIS)

    Kurayoshi, Kenta; Ozono, Eiko; Iwanaga, Ritsuko; Bradford, Andrew P.; Komori, Hideyuki; Ohtani, Kiyoshi

    2014-01-01

    Highlights: • ARF promoter showed higher responsiveness to deregulated E2F activity than the E2F1 promoter. • ARF promoter showed higher cancer cell-specificity than E2F1 promoter to drive gene expression. • HSV-TK driven by ARF promoter showed higher cancer cell-specific cytotoxicity than that driven by E2F1 promoter. - Abstract: In current cancer treatment protocols, such as radiation and chemotherapy, side effects on normal cells are major obstacles to radical therapy. To avoid these side effects, a cancer cell-specific approach is needed. One way to specifically target cancer cells is to utilize a cancer specific promoter to express a cytotoxic gene (suicide gene therapy) or a viral gene required for viral replication (oncolytic virotherapy). For this purpose, the selected promoter should have minimal activity in normal cells to avoid side effects, and high activity in a wide variety of cancers to obtain optimal therapeutic efficacy. In contrast to the AFP, CEA and PSA promoters, which have high activity only in a limited spectrum of tumors, the E2F1 promoter exhibits high activity in wide variety of cancers. This is based on the mechanism of carcinogenesis. Defects in the RB pathway and activation of the transcription factor E2F, the main target of the RB pathway, are observed in almost all cancers. Consequently, the E2F1 promoter, which is mainly regulated by E2F, has high activity in wide variety of cancers. However, E2F is also activated by growth stimulation in normal growing cells, suggesting that the E2F1 promoter may also be highly active in normal growing cells. In contrast, we found that the tumor suppressor ARF promoter is activated by deregulated E2F activity, induced by forced inactivation of pRB, but does not respond to physiological E2F activity induced by growth stimulation. We also found that the deregulated E2F activity, which activates the ARF promoter, is detected only in cancer cell lines. These observations suggest that ARF promoter

  2. Cancer cell specific cytotoxic gene expression mediated by ARF tumor suppressor promoter constructs

    Energy Technology Data Exchange (ETDEWEB)

    Kurayoshi, Kenta [Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337 (Japan); Ozono, Eiko [Centre for Molecular Oncology, Barts Cancer Institute, Queen Mary, University of London, John Vane Science Centre, Charterhouse Square, London EC1M 6BQ (United Kingdom); Iwanaga, Ritsuko; Bradford, Andrew P. [Department of Obstetrics and Gynecology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045 (United States); Komori, Hideyuki [Center for Stem Cell Biology, Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109 (United States); Ohtani, Kiyoshi, E-mail: btm88939@kwansei.ac.jp [Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337 (Japan)

    2014-07-18

    Highlights: • ARF promoter showed higher responsiveness to deregulated E2F activity than the E2F1 promoter. • ARF promoter showed higher cancer cell-specificity than E2F1 promoter to drive gene expression. • HSV-TK driven by ARF promoter showed higher cancer cell-specific cytotoxicity than that driven by E2F1 promoter. - Abstract: In current cancer treatment protocols, such as radiation and chemotherapy, side effects on normal cells are major obstacles to radical therapy. To avoid these side effects, a cancer cell-specific approach is needed. One way to specifically target cancer cells is to utilize a cancer specific promoter to express a cytotoxic gene (suicide gene therapy) or a viral gene required for viral replication (oncolytic virotherapy). For this purpose, the selected promoter should have minimal activity in normal cells to avoid side effects, and high activity in a wide variety of cancers to obtain optimal therapeutic efficacy. In contrast to the AFP, CEA and PSA promoters, which have high activity only in a limited spectrum of tumors, the E2F1 promoter exhibits high activity in wide variety of cancers. This is based on the mechanism of carcinogenesis. Defects in the RB pathway and activation of the transcription factor E2F, the main target of the RB pathway, are observed in almost all cancers. Consequently, the E2F1 promoter, which is mainly regulated by E2F, has high activity in wide variety of cancers. However, E2F is also activated by growth stimulation in normal growing cells, suggesting that the E2F1 promoter may also be highly active in normal growing cells. In contrast, we found that the tumor suppressor ARF promoter is activated by deregulated E2F activity, induced by forced inactivation of pRB, but does not respond to physiological E2F activity induced by growth stimulation. We also found that the deregulated E2F activity, which activates the ARF promoter, is detected only in cancer cell lines. These observations suggest that ARF promoter

  3. Induction of abiotic stress tolerance in plants by endophytic microbes.

    Science.gov (United States)

    Lata, R; Chowdhury, S; Gond, S K; White, J F

    2018-04-01

    Endophytes are micro-organisms including bacteria and fungi that survive within healthy plant tissues and promote plant growth under stress. This review focuses on the potential of endophytic microbes that induce abiotic stress tolerance in plants. How endophytes promote plant growth under stressful conditions, like drought and heat, high salinity and poor nutrient availability will be discussed. The molecular mechanisms for increasing stress tolerance in plants by endophytes include induction of plant stress genes as well as biomolecules like reactive oxygen species scavengers. This review may help in the development of biotechnological applications of endophytic microbes in plant growth promotion and crop improvement under abiotic stress conditions. Increasing human populations demand more crop yield for food security while crop production is adversely affected by abiotic stresses like drought, salinity and high temperature. Development of stress tolerance in plants is a strategy to cope with the negative effects of adverse environmental conditions. Endophytes are well recognized for plant growth promotion and production of natural compounds. The property of endophytes to induce stress tolerance in plants can be applied to increase crop yields. With this review, we intend to promote application of endophytes in biotechnology and genetic engineering for the development of stress-tolerant plants. © 2018 The Society for Applied Microbiology.

  4. N-Cadherin Upregulation Promotes the Neurogenic Differentiation of Menstrual Blood-Derived Endometrial Stem Cells.

    Science.gov (United States)

    Liu, Yanli; Yang, Fen; Liang, Shengying; Liu, Qing; Fu, Sulei; Wang, Zhenyu; Yang, Ciqing; Lin, Juntang

    2018-01-01

    Peripheral nerve injuries are typically caused by either trauma or medical disorders, and recently, stem cell-based therapies have provided a promising treatment approach. Menstrual blood-derived endometrial stem cells (MenSCs) are considered an ideal therapeutic option for peripheral nerve repair due to a noninvasive collection procedure and their high proliferation rate and immunological tolerance. Here, we successfully isolated MenSCs and examined their biological characteristics including their morphology, multipotency, and immunophenotype. Subsequent in vitro studies demonstrated that MenSCs express high levels of neurotrophic factors, such as NT3, NT4, BDNF, and NGF, and are capable of transdifferentiating into glial-like cells under conventional induction conditions. Moreover, upregulation of N-cadherin (N-cad) mRNA and protein expression was observed after neurogenic differentiation. In vivo studies clearly showed that N-cad knockdown via in utero electroporation perturbed the migration and maturation of mouse neural precursor cells (NPCs). Finally, a further transfection assay also confirmed that N-cad upregulation in MenSCs results in the expression of S100. Collectively, our results confirmed the paracrine effect of MenSCs on neuroprotection as well as their potential for transdifferentiation into glial-like cells and demonstrated that N-cad upregulation promotes the neurogenic differentiation of MenSCs, thereby providing support for transgenic MenSC-based therapy for peripheral nerve injury.

  5. Recombinational micro-evolution of functionally different metallothionein promoter alleles from Orchesella cincta

    Directory of Open Access Journals (Sweden)

    van Straalen Nico M

    2007-06-01

    Full Text Available Abstract Background Metallothionein (mt transcription is elevated in heavy metal tolerant field populations of Orchesella cincta (Collembola. This suggests that natural selection acts on transcriptional regulation of mt in springtails at sites where cadmium (Cd levels in soil reach toxic values This study investigates the nature and the evolutionary origin of polymorphisms in the metallothionein promoter (pmt and their functional significance for mt expression. Results We sequenced approximately 1600 bp upstream the mt coding region by genome walking. Nine pmt alleles were discovered in NW-European populations. They differ in the number of some indels, consensus transcription factor binding sites and core promoter elements. Extensive recombination events between some of the alleles can be inferred from the alignment. A deviation from neutral expectations was detected in a cadmium tolerant population, pointing towards balancing selection on some promoter stretches. Luciferase constructs were made from the most abundant alleles, and responses to Cd, paraquat (oxidative stress inducer and moulting hormone were studied in cell lines. By using paraquat we were able to dissect the effect of oxidative stress from the Cd specific effect, and extensive differences in mt induction levels between these two stressors were observed. Conclusion The pmt alleles evolved by a number of recombination events, and exhibited differential inducibilities by Cd, paraquat and molting hormone. In a tolerant population from a metal contaminated site, promoter allele frequencies differed significantly from a reference site and nucleotide polymorphisms in some promoter stretches deviated from neutral expectations, revealing a signature of balancing selection. Our results suggest that the structural differences in the Orchesella cincta metallothionein promoter alleles contribute to the metallothionein -over-expresser phenotype in cadmium tolerant populations.

  6. Novel strong tissue specific promoter for gene expression in human germ cells

    Directory of Open Access Journals (Sweden)

    Kuzmin Denis

    2010-08-01

    Full Text Available Abstract Background Tissue specific promoters may be utilized for a variety of applications, including programmed gene expression in cell types, tissues and organs of interest, for developing different cell culture models or for use in gene therapy. We report a novel, tissue-specific promoter that was identified and engineered from the native upstream regulatory region of the human gene NDUFV1 containing an endogenous retroviral sequence. Results Among seven established human cell lines and five primary cultures, this modified NDUFV1 upstream sequence (mNUS was active only in human undifferentiated germ-derived cells (lines Tera-1 and EP2102, where it demonstrated high promoter activity (~twice greater than that of the SV40 early promoter, and comparable to the routinely used cytomegaloviral promoter. To investigate the potential applicability of the mNUS promoter for biotechnological needs, a construct carrying a recombinant cytosine deaminase (RCD suicide gene under the control of mNUS was tested in cell lines of different tissue origin. High cytotoxic effect of RCD with a cell-death rate ~60% was observed only in germ-derived cells (Tera-1, whereas no effect was seen in a somatic, kidney-derived control cell line (HEK293. In further experiments, we tested mNUS-driven expression of a hyperactive Sleeping Beauty transposase (SB100X. The mNUS-SB100X construct mediated stable transgene insertions exclusively in germ-derived cells, thereby providing further evidence of tissue-specificity of the mNUS promoter. Conclusions We conclude that mNUS may be used as an efficient promoter for tissue-specific gene expression in human germ-derived cells in many applications. Our data also suggest that the 91 bp-long sequence located exactly upstream NDUFV1 transcriptional start site plays a crucial role in the activity of this gene promoter in vitro in the majority of tested cell types (10/12, and an important role - in the rest two cell lines.

  7. B Cells Promote Th1- Skewed NKT Cell Response by CD1d-TCR Interaction.

    Science.gov (United States)

    Shin, Jung Hoon; Park, Se-Ho

    2013-10-01

    CD1d expressing dendritic cells (DCs) are good glyco-lipid antigen presenting cells for NKT cells. However, resting B cells are very weak stimulators for NKT cells. Although α-galactosylceramide (α-GalCer) loaded B cells can activate NKT cells, it is not well defined whether B cells interfere NKT cell stimulating activity of DCs. Unexpectedly, we found in this study that B cells can promote Th1-skewed NKT cell response, which means a increased level of IFN-γ by NKT cells, concomitant with a decreased level of IL-4, in the circumstance of co-culture of DCs and B Cells. Remarkably, the response promoted by B cells was dependent on CD1d expression of B cells.

  8. Tolerogenic dendritic cells for regulatory T cell induction in man

    Directory of Open Access Journals (Sweden)

    Verena eRaker

    2015-11-01

    Full Text Available Dendritic cells are (DC highly specialized professional antigen-presenting cells (APC that regulate immune responses, maintaining the balance between tolerance and immunity. Mechanisms via which they can promote central and peripheral tolerance include clonal deletion, inhibition of memory T cell responses, T cell anergy and induction of regulatory T cells. These properties have led to the analysis of human tolerogenic DC as a therapeutic strategy for induction or re-establishment of tolerance. In the recent years, numerous protocols for the generation of human tolerogenic DC have been developed and their tolerogenic mechanisms, including induction of regulatory T cells, are relatively well understood. Phase I trials have been conducted in autoimmune disease, with results that emphasize the feasibility and safety of treatments with tolerogenic DC. Therefore, the scientific rationale for the use of tolerogenic DC therapy in the fields of transplantation medicine and allergic and autoimmune diseases is strong. This review will give an overview on efforts and protocols to generate human tolerogenic DC with focus on IL-10-modulated DC as inducers of regulatory T cells and discuss their clinical applications and challenges faced in further developing this form of immunotherapy.

  9. Insulin promotes cell migration by regulating PSA-NCAM

    Energy Technology Data Exchange (ETDEWEB)

    Monzo, Hector J.; Coppieters, Natacha [Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag, 92019, Auckland (New Zealand); Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag, 92019, Auckland (New Zealand); Park, Thomas I.H. [Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag, 92019, Auckland (New Zealand); Department of Pharmacology, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag, 92019, Auckland (New Zealand); Dieriks, Birger V.; Faull, Richard L.M. [Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag, 92019, Auckland (New Zealand); Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag, 92019, Auckland (New Zealand); Dragunow, Mike [Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag, 92019, Auckland (New Zealand); Department of Pharmacology, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag, 92019, Auckland (New Zealand); Curtis, Maurice A., E-mail: m.curtis@auckland.ac.nz [Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag, 92019, Auckland (New Zealand); Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag, 92019, Auckland (New Zealand)

    2017-06-01

    Cellular interactions with the extracellular environment are modulated by cell surface polysialic acid (PSA) carried by the neural cell adhesion molecule (NCAM). PSA-NCAM is involved in cellular processes such as differentiation, plasticity, and migration, and is elevated in Alzheimer's disease as well as in metastatic tumour cells. Our previous work demonstrated that insulin enhances the abundance of cell surface PSA by inhibiting PSA-NCAM endocytosis. In the present study we have identified a mechanism for insulin-dependent inhibition of PSA-NCAM turnover affecting cell migration. Insulin enhanced the phosphorylation of the focal adhesion kinase leading to dissociation of αv-integrin/PSA-NCAM clusters, and promoted cell migration. Our results show that αv-integrin plays a key role in the PSA-NCAM turnover process. αv-integrin knockdown stopped PSA-NCAM from being endocytosed, and αv-integrin/PSA-NCAM clusters co-labelled intracellularly with Rab5, altogether indicating a role for αv-integrin as a carrier for PSA-NCAM during internalisation. Furthermore, inhibition of p-FAK caused dissociation of αv-integrin/PSA-NCAM clusters and counteracted the insulin-induced accumulation of PSA at the cell surface and cell migration was impaired. Our data reveal a functional association between the insulin/p-FAK-dependent regulation of PSA-NCAM turnover and cell migration through the extracellular matrix. Most importantly, they identify a novel mechanism for insulin-stimulated cell migration. - Highlights: • Insulin modulates PSA-NCAM turnover through upregulation of p-FAK. • P-FAK modulates αv-integrin/PSA-NCAM clustering. • αv-integrin acts as a carrier for PSA-NCAM endocytosis. • Cell migration is promoted by cell surface PSA. • Insulin promotes PSA-dependent migration in vitro.

  10. Insulin promotes cell migration by regulating PSA-NCAM

    International Nuclear Information System (INIS)

    Monzo, Hector J.; Coppieters, Natacha; Park, Thomas I.H.; Dieriks, Birger V.; Faull, Richard L.M.; Dragunow, Mike; Curtis, Maurice A.

    2017-01-01

    Cellular interactions with the extracellular environment are modulated by cell surface polysialic acid (PSA) carried by the neural cell adhesion molecule (NCAM). PSA-NCAM is involved in cellular processes such as differentiation, plasticity, and migration, and is elevated in Alzheimer's disease as well as in metastatic tumour cells. Our previous work demonstrated that insulin enhances the abundance of cell surface PSA by inhibiting PSA-NCAM endocytosis. In the present study we have identified a mechanism for insulin-dependent inhibition of PSA-NCAM turnover affecting cell migration. Insulin enhanced the phosphorylation of the focal adhesion kinase leading to dissociation of αv-integrin/PSA-NCAM clusters, and promoted cell migration. Our results show that αv-integrin plays a key role in the PSA-NCAM turnover process. αv-integrin knockdown stopped PSA-NCAM from being endocytosed, and αv-integrin/PSA-NCAM clusters co-labelled intracellularly with Rab5, altogether indicating a role for αv-integrin as a carrier for PSA-NCAM during internalisation. Furthermore, inhibition of p-FAK caused dissociation of αv-integrin/PSA-NCAM clusters and counteracted the insulin-induced accumulation of PSA at the cell surface and cell migration was impaired. Our data reveal a functional association between the insulin/p-FAK-dependent regulation of PSA-NCAM turnover and cell migration through the extracellular matrix. Most importantly, they identify a novel mechanism for insulin-stimulated cell migration. - Highlights: • Insulin modulates PSA-NCAM turnover through upregulation of p-FAK. • P-FAK modulates αv-integrin/PSA-NCAM clustering. • αv-integrin acts as a carrier for PSA-NCAM endocytosis. • Cell migration is promoted by cell surface PSA. • Insulin promotes PSA-dependent migration in vitro.

  11. Cytotoxic potential of decidual NK cells and CD8+ T cells awakened by infections.

    Science.gov (United States)

    Crespo, Ângela C; van der Zwan, Anita; Ramalho-Santos, João; Strominger, Jack L; Tilburgs, Tamara

    2017-02-01

    To establish a healthy pregnancy the maternal immune system must tolerate fetal allo-antigens, yet remain competent to respond to infections. The ability of decidual NK cells (dNK) to promote migration of fetal extravillous trophoblasts (EVT) and placental growth as well as the capacity of EVT to promote immune tolerance are topics of high interest and extensive research. However, the problem of how dNK and decidual CD8+ T cells (CD8+ dT) provide immunity to infections of the placenta and the mechanisms that regulate their cytolytic function has thus far largely been ignored. Fetal EVT are the most invasive cells of the placenta and directly interact with maternal decidual immune cells at this maternal-fetal interface. Besides the expression of non-polymorphic HLA-E and HLA-G molecules that are associated with immune tolerance, EVT also express highly polymorphic HLA-C molecules that can serve as targets for maternal dNK and CD8+ dT responses. HLA-C expression by EVT has a dual role as the main molecule to which immune tolerance needs to be established and as the only molecule that can present pathogen-derived peptides and provide protective immunity when EVT are infected. The focus of this review is to address the regulation of cytotoxicity of dNK and CD8+ dT, which is essential for maternal-fetal immune tolerance as well as recent evidence that both cell types can provide immunity to infections at the maternal-fetal interface. A particular emphasis is given to the role of HLA-C expressed by EVT and its capacity to elicit dNK and CD8+ dT responses. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  12. Cross-Generational Reproductive Fitness Enforced by Microchimeric Maternal Cells.

    Science.gov (United States)

    Kinder, Jeremy M; Jiang, Tony T; Ertelt, James M; Xin, Lijun; Strong, Beverly S; Shaaban, Aimen F; Way, Sing Sing

    2015-07-30

    Exposure to maternal tissue during in utero development imprints tolerance to immunologically foreign non-inherited maternal antigens (NIMA) that persists into adulthood. The biological advantage of this tolerance, conserved across mammalian species, remains unclear. Here, we show maternal cells that establish microchimerism in female offspring during development promote systemic accumulation of immune suppressive regulatory T cells (Tregs) with NIMA specificity. NIMA-specific Tregs expand during pregnancies sired by males expressing alloantigens with overlapping NIMA specificity, thereby averting fetal wastage triggered by prenatal infection and non-infectious disruptions of fetal tolerance. Therefore, exposure to NIMA selectively enhances reproductive success in second-generation females carrying embryos with overlapping paternally inherited antigens. These findings demonstrate that genetic fitness, canonically thought to be restricted to Mendelian inheritance, is enhanced in female placental mammals through vertically transferred maternal cells that promote conservation of NIMA and enforce cross-generational reproductive benefits. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Insulin resistance according to β-cell function in women with polycystic ovary syndrome and normal glucose tolerance.

    Directory of Open Access Journals (Sweden)

    Do Kyeong Song

    Full Text Available Polycystic ovary syndrome (PCOS is associated with insulin resistance (IR and compensatory hyperinsulinemia. IR is recognized as a major risk factor for the development of type 2 diabetes mellitus. However, few studies have investigated IR in women with PCOS and normal glucose tolerance. The objective of this study was to evaluate IR and β-cell function in women with PCOS and normal glucose tolerance. Additionally, we sought to evaluate the usefulness of oral glucose tolerance test (OGTT-derived IR indices in lean women with PCOS.We recruited 100 women with PCOS and normal glucose tolerance and 100 age- and BMI-matched women as controls. IR and insulin secretory indices, including the homeostasis-model assessment (HOMA-IR, HOMA-M120, HOMA-F and the Stumvoll index, were calculated from an OGTT. Increased β-cell function was defined as>75th percentile for the HOMA-F in control women.Women with PCOS had higher values for post-load 2-hour glucose, fasting insulin, post-load 2-hour insulin, HOMA-IR, HOMA-M120, HOMA-F and lower values for the Stumvoll index than the controls (all Ps<0.05. Women with PCOS and increased β-cell function showed lower Stumvoll index values than the matched controls (P<0.05. The HOMA-F was significantly associated with the HOMA-M120 and Stumvoll index when adjusted for age and BMI in a multiple regression analysis (all Ps<0.05. The HOMA-M120 was positively correlated with triglycerides and free testosterone, and the Stumvoll index was negatively correlated with triglycerides and free testosterone in lean women with PCOS (all Ps<0.05.Women with PCOS and normal glucose tolerance showed higher IR than controls matched for age, BMI, and β-cell function. β-cell function was increased in women with PCOS when compared to the matched controls, but not when the lean subjects were compared to the matched controls separately. Therefore, early evaluation of IR in women with PCOS and normal glucose tolerance may be needed.

  14. Fish kidney cells show higher tolerance to hyperosmolality than amphibian

    Directory of Open Access Journals (Sweden)

    Lang Gui

    2018-05-01

    Full Text Available In contrast to fish, amphibians inhabit both aquatic and terrestrial environments. To better understand osmoregulation in fish and amphibian, we have investigated the morphological changes in kidney cells to osmotic stress. To address this, kidney cell line isolated from the freshwater grass carp (CIK and Chinese giant salamander (GSK were challenged to different mediums with distinct osmotic pressures (100, 300 and 700 mOsm. Morphological alterations of the fish and amphibian cells were compared by optical and electron microscopy. Following hyposmotic treatment (100 mOsm, both CIK and GSK cells became unhealthy and show condensed chromatin, swollen mitochondria and cytoplasmic vacuole. Meanwhile, after hyperosmotic treatment (700 mOsm, shrunken CIK cells with multipolar shape, pale or lightly stained cytoplasm, condensed chromatin, vacuoles and swollen mitochondria were detected. GSK cells were seriously damaged and most were completely lysed. The results suggest that fish kidney cells show a higher degree of tolerance to hyperosmoticity by comparing to amphibians and provide novel insights on the osmoregulatory capacity and adaptability of kidney cells between the two animal groups.

  15. Political Socialization, Tolerance, and Sexual Identity

    Science.gov (United States)

    Avery, Patricia G.

    2002-01-01

    Key concepts in political socialization, tolerance, groups, rights and responsibilities can be used to understand the way in which young people struggle with sexual identity issues. Educators may promote greater tolerance for homosexuality among heterosexuals by situating sexual identity issues within a broader discussion of democratic principles.…

  16. Reformate tolerant electrocatalysts in solid polymer fuel cell membrane electrode assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, S J; Gunner, A G; Thompsett, D; Hards, G A

    1998-12-31

    The aim of the project was to evaluate a series of platinum group metal catalysts which had previously been identified from a wide range of areas related to carbon monoxide (CO) activation, and to demonstrate superior intrinsic reformate tolerance to current platinum/ruthenium technology as anode catalysts for Proton Exchange Membrane Fuel Cells (PEMFC). (author)

  17. Use of hematopoietic cell transplants to achieve tolerance in patients with solid organ transplants.

    Science.gov (United States)

    Strober, Samuel

    2016-03-24

    The goals of tolerance in patients with solid organ transplants are to eliminate the lifelong need for immunosuppressive (IS) drugs and to prevent graft loss due to rejection or drug toxicity. Tolerance with complete withdrawal of IS drugs has been achieved in recipients of HLA-matched and mismatched living donor kidney transplants in 3 medical centers using hematopoietic cell transplants to establish mixed or complete chimerism. © 2016 by The American Society of Hematology.

  18. Natural killer cells promote early CD8 T cell responses against cytomegalovirus.

    Directory of Open Access Journals (Sweden)

    Scott H Robbins

    2007-08-01

    Full Text Available Understanding the mechanisms that help promote protective immune responses to pathogens is a major challenge in biomedical research and an important goal for the design of innovative therapeutic or vaccination strategies. While natural killer (NK cells can directly contribute to the control of viral replication, whether, and how, they may help orchestrate global antiviral defense is largely unknown. To address this question, we took advantage of the well-defined molecular interactions involved in the recognition of mouse cytomegalovirus (MCMV by NK cells. By using congenic or mutant mice and wild-type versus genetically engineered viruses, we examined the consequences on antiviral CD8 T cell responses of specific defects in the ability of the NK cells to control MCMV. This system allowed us to demonstrate, to our knowledge for the first time, that NK cells accelerate CD8 T cell responses against a viral infection in vivo. Moreover, we identify the underlying mechanism as the ability of NK cells to limit IFN-alpha/beta production to levels not immunosuppressive to the host. This is achieved through the early control of cytomegalovirus, which dramatically reduces the activation of plasmacytoid dendritic cells (pDCs for cytokine production, preserves the conventional dendritic cell (cDC compartment, and accelerates antiviral CD8 T cell responses. Conversely, exogenous IFN-alpha administration in resistant animals ablates cDCs and delays CD8 T cell activation in the face of NK cell control of viral replication. Collectively, our data demonstrate that the ability of NK cells to respond very early to cytomegalovirus infection critically contributes to balance the intensity of other innate immune responses, which dampens early immunopathology and promotes optimal initiation of antiviral CD8 T cell responses. Thus, the extent to which NK cell responses benefit the host goes beyond their direct antiviral effects and extends to the prevention of innate

  19. Vaccination with apoptosis colorectal cancer cell pulsed autologous ...

    African Journals Online (AJOL)

    user

    2011-02-18

    Feb 18, 2011 ... with DCs vaccine to assess toxicity, tolerability, immune and clinical responses to the vaccine. No ... Key words: Dendritic cells, immunotherapy, colorectal cancer. .... color analyses of DCs, cells were labeled simultaneously with ..... promote CD8+ Tc1 cell survival, memory response, tumor localization and ...

  20. Dendritic cell-specific deletion of β-catenin results in fewer regulatory T-cells without exacerbating autoimmune collagen-induced arthritis

    NARCIS (Netherlands)

    C.H. Alves (Celso Henrique); J.L. Ober-Blöbaum (Julia); I. Brouwers-Haspels (Inge); P. Asmawidjaja (Patrick); A.M.C. Mus (Adriana); W. Razawy (Wida); M. Molendijk (Marlieke); B.E. Clausen (Bjorn); E.W. Lubberts (Erik)

    2015-01-01

    textabstractDendritic cells (DCs) are professional antigen presenting cells that have the dual ability to stimulate immunity and maintain tolerance. However, the signalling pathways mediating tolerogenic DC function in vivo remain largely unknown. The β-catenin pathway has been suggested to promote

  1. Inflammatory Th17 cells promote depression-like behavior in mice

    Science.gov (United States)

    Beurel, Eléonore; Harrington, Laurie E.; Jope, Richard S.

    2012-01-01

    Background Recognition of substantial immune-neural interactions is revising dogmas about their insular actions and revealing that immune-neural interactions can substantially impact CNS functions. The inflammatory cytokine interleukin-6 promotes susceptibility to depression and drives production of inflammatory T helper 17 (Th17) T cells, raising the hypothesis that in mouse models Th17 cells promote susceptibility to depression-like behaviors. Methods Behavioral characteristics were measured in male mice administered Th17 cells, CD4+ cells, or vehicle, and in RORγT+/GFP mice or male mice treated with RORγT inhibitor or anti-IL-17A antibodies. Results Mouse brain Th17 cells were elevated by learned helplessness and chronic restraint stress, two common depression-like models. Th17 cell administration promoted learned helplessness in 89% of mice in a paradigm where no vehicle-treated mice developed learned helplessness, and impaired novelty suppressed feeding and social interaction behaviors. Mice deficient in the RORγT transcription factor necessary for Th17 cell production exhibited resistance to learned helplessness, identifying modulation of RORγT as a potential intervention. Treatment with the RORγT inhibitor SR1001, or anti-IL-17A antibodies to abrogate Th17 cell function, reduced Th17-dependent learned helplessness. Conclusions These findings indicate that Th17 cells are increased in the brain during depression-like states, promote depression-like behaviors in mice, and specifically inhibiting the production or function of Th17 cells reduces vulnerability to depression-like behavior, suggesting antidepressant effects may be attained by targeting Th17 cells. PMID:23174342

  2. Predicting Neuroinflammation in Morphine Tolerance for Tolerance Therapy from Immunostaining Images of Rat Spinal Cord.

    Directory of Open Access Journals (Sweden)

    Shinn-Long Lin

    Full Text Available Long-term morphine treatment leads to tolerance which attenuates analgesic effect and hampers clinical utilization. Recent studies have sought to reveal the mechanism of opioid receptors and neuroinflammation by observing morphological changes of cells in the rat spinal cord. This work proposes a high-content screening (HCS based computational method, HCS-Morph, for predicting neuroinflammation in morphine tolerance to facilitate the development of tolerance therapy using immunostaining images for astrocytes, microglia, and neurons in the spinal cord. HCS-Morph first extracts numerous HCS-based features of cellular phenotypes. Next, an inheritable bi-objective genetic algorithm is used to identify a minimal set of features by maximizing the prediction accuracy of neuroinflammation. Finally, a mathematic model using a support vector machine with the identified features is established to predict drug-treated images to assess the effects of tolerance therapy. The dataset consists of 15 saline controls (1 μl/h, 15 morphine-tolerant rats (15 μg/h, and 10 rats receiving a co-infusion of morphine (15 μg/h and gabapentin (15 μg/h, Sigma. The three individual models of astrocytes, microglia, and neurons for predicting neuroinflammation yielded respective Jackknife test accuracies of 96.67%, 90.00%, and 86.67% on the 30 rats, and respective independent test accuracies of 100%, 90%, and 60% on the 10 co-infused rats. The experimental results suggest that neuroinflammation activity expresses more predominantly in astrocytes and microglia than in neuron cells. The set of features for predicting neuroinflammation from images of astrocytes comprises mean cell intensity, total cell area, and second-order geometric moment (relating to cell distribution, relevant to cell communication, cell extension, and cell migration, respectively. The present investigation provides the first evidence for the role of gabapentin in the attenuation of morphine tolerance from

  3. Resistance of transplantation tolerance to X-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Holan, V; Hasek, M; Chutna, J [Czechoslovak Academy of Sciences, Prague. Institute of Molecular Genetics

    1979-04-01

    With regard to the previous finding that suppressor cells participating in the state of transplantation tolerance were radiosensitive, the possibility was investigated whether tolerance can be abolished by irradiation. In the rat model used (AVN recipients, Lewis donors), both neonatally induced tolerance and tolerance induced in the adult life by the transfer of suppressor cells were found to be radioresistant.

  4. Microbiota-Dependent Crosstalk Between Macrophages and ILC3 Promotes Intestinal Homeostasis

    Science.gov (United States)

    Mortha, Arthur; Chudnovskiy, Aleksey; Hashimoto, Daigo; Bogunovic, Milena; Spencer, Sean P.; Belkaid, Yasmine; Merad, Miriam

    2014-01-01

    The intestinal microbiota and tissue-resident myeloid cells promote immune responses that maintain intestinal homeostasis in the host. However, the cellular cues that translate microbial signals into intestinal homeostasis remain unclear. Here, we show that deficient granulocyte-macrophage colony-stimulating factor (GM-CSF) production altered mononuclear phagocyte effector functions and led to reduced regulatory T cell (Treg) numbers and impaired oral tolerance. We observed that RORγt+ innate lymphoid cells (ILCs) are the primary source of GM-CSF in the gut and that ILC-driven GM-CSF production was dependent on the ability of macrophages to sense microbial signals and produce interleukin-1β. Our findings reveal that commensal microbes promote a crosstalk between innate myeloid and lymphoid cells that leads to immune homeostasis in the intestine. PMID:24625929

  5. Microbiota-dependent crosstalk between macrophages and ILC3 promotes intestinal homeostasis.

    Science.gov (United States)

    Mortha, Arthur; Chudnovskiy, Aleksey; Hashimoto, Daigo; Bogunovic, Milena; Spencer, Sean P; Belkaid, Yasmine; Merad, Miriam

    2014-03-28

    The intestinal microbiota and tissue-resident myeloid cells promote immune responses that maintain intestinal homeostasis in the host. However, the cellular cues that translate microbial signals into intestinal homeostasis remain unclear. Here, we show that deficient granulocyte-macrophage colony-stimulating factor (GM-CSF) production altered mononuclear phagocyte effector functions and led to reduced regulatory T cell (T(reg)) numbers and impaired oral tolerance. We observed that RORγt(+) innate lymphoid cells (ILCs) are the primary source of GM-CSF in the gut and that ILC-driven GM-CSF production was dependent on the ability of macrophages to sense microbial signals and produce interleukin-1β. Our findings reveal that commensal microbes promote a crosstalk between innate myeloid and lymphoid cells that leads to immune homeostasis in the intestine.

  6. T cell immunity

    OpenAIRE

    Emel Bülbül Başkan

    2013-01-01

    Since birth, our immune system is constantly bombarded with self-antigens and foreign pathogens. To stay healthy, complex immune strategies have evolved in our immune system to maintain self-tolerance and to defend against foreign pathogens. Effector T cells are the key players in steering the immune responses to execute immune functions. While effector T cells were initially identified to be immune promoting, recent studies unraveled negative regulatory functions of effector T cells...

  7. Network topologies and dynamics leading to endotoxin tolerance and priming in innate immune cells.

    Directory of Open Access Journals (Sweden)

    Yan Fu

    Full Text Available The innate immune system, acting as the first line of host defense, senses and adapts to foreign challenges through complex intracellular and intercellular signaling networks. Endotoxin tolerance and priming elicited by macrophages are classic examples of the complex adaptation of innate immune cells. Upon repetitive exposures to different doses of bacterial endotoxin (lipopolysaccharide or other stimulants, macrophages show either suppressed or augmented inflammatory responses compared to a single exposure to the stimulant. Endotoxin tolerance and priming are critically involved in both immune homeostasis and the pathogenesis of diverse inflammatory diseases. However, the underlying molecular mechanisms are not well understood. By means of a computational search through the parameter space of a coarse-grained three-node network with a two-stage Metropolis sampling approach, we enumerated all the network topologies that can generate priming or tolerance. We discovered three major mechanisms for priming (pathway synergy, suppressor deactivation, activator induction and one for tolerance (inhibitor persistence. These results not only explain existing experimental observations, but also reveal intriguing test scenarios for future experimental studies to clarify mechanisms of endotoxin priming and tolerance.

  8. Tolerância à salinidade em feijão (Phaseolus vulgaris L Salt tolerance in bean (Paseolus vulgaris cell culture

    Directory of Open Access Journals (Sweden)

    F. Broetto

    1995-04-01

    Full Text Available Uma das aplicações das técnicas da cultura de tecidos no melhoramento é a identificação de linhas de células que apresentam tolerância à salinidade. Vários autores obtiveram linhas de células tolerantes ao estresse salino; e estudo de mecanismos bioquímicos da tolerância a sais em plantas tem demonstrado altas correlações entre estes e o acúmulo de macromoléculas em tecido de plantas superiores. Para verificar essas correlações em feijão (Phaseolus vulgaris cv IAC carioca, calos oriundos de eixos embrionários foram cultivados em meio sólido, suplementado com NaCl nas concentrações de 0 a 60 mM. Após 13 dias de incubação, os calos foram coletados e analisados quanto ao crescimento relativo, teor de proteínas, teor de prolina e atividade da peroxidase. Os parâmetros analisados mostraram decréscimo no crescimento relativo e no de proteínas em resposta ao NaCl. Paralelamente, observou-se aumento significativo no conteúdo de prolina e atividade da enzima peroxidase.One of the applications of the tissue culture technique in plant improvement is the identification of cell lines which show salinity tolerance. Several authors were able to obtain saline stress-tolerant cell lines and show that mechanisms of tolerance to salts have a strong correlation between this phenomenon and a high macromolecule concentration in plant tissues. Callus obtained from embrionic axis of Phaseolus vulgarís cv. IAC carioca in solid medium, supplemented with 0 to 60 mM NaCl, as the salt treatment, were used. Callus harvesting was done on the 13th day, when they were processed for relative growth, protein, proline content and peroxidase acivity. The results show both, a decrease of the relative growth and of protein content in response to the NaCl treatment, as compared to controls. However, there was a significant increase on the proline content and on the peroxidase activity.

  9. Environmental peer pressure: CD4+ T cell help in tolerance and transplantation.

    Science.gov (United States)

    Tedesco, Dana; Grakoui, Arash

    2018-01-01

    The liver participates in a multitude of metabolic functions that are critical for sustaining human life. Despite constant encounters with antigenic-rich intestinal blood, oxidative stress, and metabolic intermediates, there is no appreciable immune response. Interestingly, patients undergoing orthotopic liver transplantation benefit from a high rate of graft acceptance in comparison to other solid organ transplant recipients. In fact, cotransplantation of a donor liver in tandem with a rejection-prone graft increases the likelihood of graft acceptance. A variety of players may account for this phenomenon including the interaction of intrahepatic antigen-presenting cells with CD4 + T cells and the preferential induction of forkhead box P3 (Foxp3) expression on CD4 + T cells following injurious stimuli. Ineffective insult management can cause chronic liver disease, which manifests systemically as the following: antibody-mediated disorders, ineffective antiviral and antibacterial immunity, and gastrointestinal disorders. These sequelae sharing the requirement of CD4 + T cell help to coordinate aberrant immune responses. In this review, we will focus on CD4 + T cell help due to the shared requirements in hepatic tolerance and coordination of extrahepatic immune responses. Overall, intrahepatic deviations from steady state can have deleterious systemic immune outcomes and highlight the liver's remarkable capacity to maintain a balance between tolerance and inflammatory response while simultaneously being inundated with a panoply of antigenic stimuli. Liver Transplantation 24 89-97 2018 AASLD. © 2017 by the American Association for the Study of Liver Diseases.

  10. Building tolerance by dismantling synapses: inhibitory receptor signaling in natural killer cells.

    Science.gov (United States)

    Huse, Morgan; Catherine Milanoski, S; Abeyweera, Thushara P

    2013-01-01

    Cell surface receptors bearing immunotyrosine-based inhibitory motifs (ITIMs) maintain natural killer (NK) cell tolerance to normal host tissues. These receptors are difficult to analyze mechanistically because they block activating responses in a rapid and comprehensive manner. The advent of high-resolution single cell imaging techniques has enabled investigators to explore the cell biological basis of the inhibitory response. Recent studies using these approaches indicate that ITIM-containing receptors function at least in part by structurally undermining the immunological synapse between the NK cell and its target. In this review, we discuss these new advances and how they might relate to what is known about the biochemistry of inhibitory signaling in NK cells and other cell types. © 2012 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

  11. Increasing Stem Cell Dose Promotes Posttransplant Immune Reconstitution.

    Science.gov (United States)

    Xu, Ning; Shen, Sylvie; Dolnikov, Alla

    2017-04-01

    Umbilical cord blood (UCB) transplantation can provide a successful therapeutic option for patients that have no suitable related donor. UCB transplantation is often limited by the relatively small hematopoietic stem cell (HSC) numbers in UCB especially for adult recipients. Early neutrophil and platelet engraftment correlates with the stem cell numbers in UCB transplant. Compared to other HSC sources, immune reconstitution following UCB transplant is slower and complicated by increased frequency of opportunistic infections. The effect of HSC numbers in UCB transplant on immune reconstitution was not thoroughly examined. Using immunocompromised mice transplanted with purified UCB CD34+ stem cells, we have demonstrated that increasing the numbers of CD34+ cells in the transplant promotes hematopoietic and immune reconstitution. At early stages posttransplant, high stem cell dose generated relatively more B cells, while lower dose generated more myeloid and T cells. Thus, the size of the stem cell graft appears to modulate the differentiation potential of infused stem cells. In addition, increasing stem cell dose in the transplant improved CD8+ T cell development and delayed late memory T cell skewing in expense of naive T cells highlighting the importance of HSC dose to maintain the pool of naive T cells able to develop strong immune responses. Transplantation of ex vivo expanded CD34+ cells did not promote, but rather delayed immune reconstitution suggesting the loss of primitive lymphoid precursor cells during ex vivo expansion.

  12. Effects of T cell depletion in radiation bone marrow chimeras. II. Requirement for allogeneic T cells in the reconstituting bone marrow inoculum for subsequent resistance to breaking of tolerance

    International Nuclear Information System (INIS)

    Sykes, M.; Sheard, M.A.; Sachs, D.H.

    1988-01-01

    The ability of normal recipient-type lymphocytes to break tolerance in long-term allogenic radiation chimeras has been investigated. Reconstitution of lethally irradiated mice with a mixture of syngeneic and allogeneic T cell-depleted (TCD) bone marrow (BM) has previously been shown to lead to mixed chimerism and permanent, specific tolerance to donor and host alloantigen (3-5). If allogeneic T cells are not depleted from the reconstituting inoculum, complete allogeneic chimerism results; however, no clinical evidence for GVHD is observed, presumably due to the protective effect provided by syngeneic TCD BM. This model has now been used to study the effects of allogenic T cells administered in reconstituting BM inocula on stability of long-term tolerance. We have attempted to break tolerance in long-term chimeras originally reconstituted with TCD or non-TCD BM by challenging them with inocula containing normal, nontolerant recipient strain lymphocytes. tolerance was broken with remarkable ease in recipients of mixed marrow inocula in which both original BM components were TCD. In contrast, tolerance in chimeras originally reconstituted with non-TCD allogeneic BM was not affected by such inocula. Susceptibility to loss of chimerism and tolerance was not related to initial levels of chimerism per se, but rather to T cell depletion of allogeneic BM, since chimeras reconstituted with TCD allogeneic BM alone (mean level of allogeneic chimerism 98%) were as susceptible as mixed chimeras to the tolerance-breaking effects of such inocula. The possible contribution of GVH reactivity to this resistance was investigated using an F1 into parent strain combination. In these animals, the use of non-TCD F1 BM inocula for reconstitution did not lead to resistance to the tolerance-breaking effects of recipient strain splenocytes

  13. In vitro selection of induced mutants to salt-tolerance: Inducible gene regulation for salt tolerance

    Energy Technology Data Exchange (ETDEWEB)

    Winicov, I [Department of Microbiology and Biochemistry, Univ. of Nevada-Reno, Reno, NV (United States)

    1997-07-01

    A selection protocol to obtain salt tolerant calli, followed by regeneration and progeny-test of the regenerated plants for salt tolerance in rice was investigated. Callus cultures were initiated from salt-sensitive US elite rice lines and cv. `Pokkali`. Salt-tolerant cell lines were selected from these by a single step selection procedure. The selected salt-tolerant lines grew well on medium with {+-} 0.5% or 1% NaCl, while the parent lines occasionally survived, but did not grow at these salt concentrations. Plants were regenerated from these cell lines through different passages on medium containing salt. Seed was collected from the regenerated plants and salt tolerance of R2 seedlings was compared with those regenerated without salt selection. Salt-tolerance was measured by survival and productive growth of newly germinated seedlings in Hoagland solution with 0.3% and 0.5% NaCl for 4 weeks. Heritable improvement in salt tolerance was obtained in R2 seedlings from one plant regenerated after 5 months selection. Survival and growth of these seedlings was equivalent to that from `Pokkali` seedlings. These results show that cellular tolerance can provide salt-tolerance in rice plants. (author). 6 refs, 2 tabs.

  14. In vitro selection of induced mutants to salt-tolerance: Inducible gene regulation for salt tolerance

    International Nuclear Information System (INIS)

    Winicov, I.

    1997-01-01

    A selection protocol to obtain salt tolerant calli, followed by regeneration and progeny-test of the regenerated plants for salt tolerance in rice was investigated. Callus cultures were initiated from salt-sensitive US elite rice lines and cv. 'Pokkali'. Salt-tolerant cell lines were selected from these by a single step selection procedure. The selected salt-tolerant lines grew well on medium with ± 0.5% or 1% NaCl, while the parent lines occasionally survived, but did not grow at these salt concentrations. Plants were regenerated from these cell lines through different passages on medium containing salt. Seed was collected from the regenerated plants and salt tolerance of R2 seedlings was compared with those regenerated without salt selection. Salt-tolerance was measured by survival and productive growth of newly germinated seedlings in Hoagland solution with 0.3% and 0.5% NaCl for 4 weeks. Heritable improvement in salt tolerance was obtained in R2 seedlings from one plant regenerated after 5 months selection. Survival and growth of these seedlings was equivalent to that from 'Pokkali' seedlings. These results show that cellular tolerance can provide salt-tolerance in rice plants. (author). 6 refs, 2 tabs

  15. Freezing tolerance of ectomycorrhizal fungi in pure culture.

    Science.gov (United States)

    Lehto, Tarja; Brosinsky, Arlena; Heinonen-Tanski, Helvi; Repo, Tapani

    2008-10-01

    The ability to survive freezing and thawing is a key factor for the existence of life forms in large parts of the world. However, little is known about the freezing tolerance of mycorrhizal fungi and their role in the freezing tolerance of mycorrhizas. Threshold temperatures for the survival of these fungi have not been assessed experimentally. We grew isolates of Suillus luteus, Suillus variegatus, Laccaria laccata, and Hebeloma sp. in liquid culture at room temperature. Subsequently, we exposed samples to a series of temperatures between +5 degrees C and -48 degrees C. Relative electrolyte leakage (REL) and re-growth measurements were used to assess the damage. The REL test indicated that the lethal temperature for 50% of samples (LT(50)) was between -8.3 degrees C and -13.5 degrees C. However, in the re-growth experiment, all isolates resumed growth after exposure to -8 degrees C and higher temperatures. As many as 64% of L. laccata samples but only 11% in S. variegatus survived -48 degrees C. There was no growth of Hebeloma and S. luteus after exposure to -48 degrees C, but part of their samples survived -30 degrees C. The fungi tolerated lower temperatures than was expected on the basis of earlier studies on fine roots of ectomycorrhizal trees. The most likely freezing tolerance mechanism here is tolerance to apoplastic freezing and the concomitant intracellular dehydration with consequent concentrating of cryoprotectant substances in cells. Studying the properties of fungi in isolation promotes the understanding of the role of the different partners of the mycorrhizal symbiosis in the freezing tolerance.

  16. Mesenchymal stem cells promote cell invasion and migration and autophagy-induced epithelial-mesenchymal transition in A549 lung adenocarcinoma cells.

    Science.gov (United States)

    Luo, Dan; Hu, Shiyuan; Tang, Chunlan; Liu, Guoxiang

    2018-03-01

    Mesenchymal stem cells (MSCs) are recruited into the tumour microenvironment and promote tumour growth and metastasis. Tumour microenvironment-induced autophagy is considered to suppress primary tumour formation by impairing migration and invasion. Whether these recruited MSCs regulate tumour autophagy and whether autophagy affects tumour growth are controversial. Our data showed that MSCs promote autophagy activation, reactive oxygen species production, and epithelial-mesenchymal transition (EMT) as well as increased migration and invasion in A549 cells. Decreased expression of E-cadherin and increased expression of vimentin and Snail were observed in A549 cells cocultured with MSCs. Conversely, MSC coculture-mediated autophagy positively promoted tumour EMT. Autophagy inhibition suppressed MSC coculture-mediated EMT and reduced A549 cell migration and invasion slightly. Furthermore, the migratory and invasive abilities of A549 cells were additional increased when autophagy was further enhanced by rapamycin treatment. Taken together, this work suggests that microenvironments containing MSCs can promote autophagy activation for enhancing EMT; MSCs also increase the migratory and invasive abilities of A549 lung adenocarcinoma cells. Mesenchymal stem cell-containing microenvironments and MSC-induced autophagy signalling may be potential targets for blocking lung cancer cell migration and invasion. Copyright © 2018 John Wiley & Sons, Ltd.

  17. Enhancing the methanol tolerance of platinum nanoparticles for the cathode reaction of direct methanol fuel cells through a geometric design.

    Science.gov (United States)

    Feng, Yan; Ye, Feng; Liu, Hui; Yang, Jun

    2015-11-18

    Mastery over the structure of nanoparticles might be an effective way to enhance their performance for a given application. Herein we demonstrate the design of cage-bell nanostructures to enhance the methanol tolerance of platinum (Pt) nanoparticles while remaining their catalytic activity for oxygen reduction reaction. This strategy starts with the synthesis of core-shell-shell nanoparticles with Pt and silver (Ag) residing respectively in the core and inner shell regions, which are then agitated with saturated sodium chloride (NaCl) solution to eliminate the Ag component from the inner shell region, leading to the formation of bimetallic nanoparticles with a cage-bell structure, defined as a movable Pt core enclosed by a metal shell with nano-channels, which exhibit superior methanol-tolerant property in catalyzing oxygen reduction reaction due to the different diffusion behaviour of methanol and oxygen in the porous metal shell of cage-bell structured nanoparticles. In particular, the use of remarkably inexpensive chemical agent (NaCl) to promote the formation of cage-bell structured particles containing a wide spectrum of metal shells highlights its engineering merit to produce highly selective electrocatalysts on a large scale for the cathode reaction of direct methanol fuel cells.

  18. Goblet Cells Contribute to Ocular Surface Immune Tolerance-Implications for Dry Eye Disease

    NARCIS (Netherlands)

    Barbosa, Flavia L; Xiao, Yangyan; Bian, Fang; Coursey, Terry G; Ko, Byung Yi; Clevers, Hans; de Paiva, Cintia S; Pflugfelder, Stephen C

    2017-01-01

    Conjunctival goblet cell (GC) loss in dry eye is associated with ocular surface inflammation. This study investigated if conjunctival GCs contribute to ocular surface immune tolerance. Antigens applied to the ocular surface, imaged by confocal microscopy, passed into the conjunctival stroma through

  19. Promotion of SH-SY5Y Cell Growth by Gold Nanoparticles Modified with 6-Mercaptopurine and a Neuron-Penetrating Peptide

    Science.gov (United States)

    Xiao, Yaruo; Zhang, Enqi; Fu, Ailing

    2017-12-01

    Much effort has been devoted to the discovery of effective biomaterials for nerve regeneration. Here, we reported a novel application of gold nanoparticles (AuNPs) modified with 6-mercaptopurine (6MP) and a neuron-penetrating peptide (RDP) as a neurophic agent to promote proliferation and neurite growth of human neuroblastoma (SH-SY5Y) cells. When the cells were treated with 6MP-AuNPs-RDP conjugates, they showed higher metabolic activity than the control. Moreover, SH-SY5Y cells were transplanted onto the surface coated with 6MP-AuNPs-RDP to examine the effect of neurite development. It can be concluded that 6MP-AuNPs-RDP attached to the cell surface and then internalized into cells, leading to a significant increase of neurite growth. Even though 6MP-AuNPs-RDP-treated cells were recovered from frozen storage, the cells still maintained constant growth, indicating that the cells have excellent tolerance to 6MP-AuNPs-RDP. The results suggested that the 6MP-AuNPs-RDP had promising potential to be developed as a neurophic nanomaterial for neuronal growth.

  20. Cytokine regulation of immune tolerance

    OpenAIRE

    Wu, Jie; Xie, Aini; Chen, Wenhao

    2014-01-01

    The immune system provides defenses against invading pathogens while maintaining immune tolerance to self-antigens. This immune homeostasis is harmonized by the direct interactions between immune cells and the cytokine environment in which immune cells develop and function. Herein, we discuss three non-redundant paradigms by which cytokines maintain or break immune tolerance. We firstly describe how anti-inflammatory cytokines exert direct inhibitory effects on immune cells to enforce immune ...

  1. Co-tolerant anode electrocatalysts for impure hydrogen oxidation in solid polymer fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, S J; Thompsett, D [Johnson Matthey Technology Centre, Sonning Common (United Kingdom); Tseung, A C.C.; Chen, K Y [Essex Univ., Colchester (United Kingdom)

    1997-09-01

    Recent work by the Chemical Energy Research Centre (CERC) at the University of Essex under the direction of Professor A.C.C. Tseung has investigated the combination of tungsten trioxide (WO{sub 3}) with carbon supported platinum (Pt) and platinum ruthenium (PtRu) catalysts for carbon monoxide (CO) tolerance for application in low temperature fuel cells. In particular, a catalyst combining Pt, Ru and WO{sub 3} gave a significantly improved tolerance to the effect of CO on H{sub 2} oxidation, at 80{sup o}C using fuel of 100 ppm CO in H{sub 2} and 0.5 M sulphuric acid (H{sub 2}SO{sub 4}) electrolyte. The aim of this project was to make a direct comparison between the catalyst technology developed at the University of Essex with the current Johnson Matthey PtRu catalyst technology as used in Proton Exchange Fuel Cells (PEMFC). (Author)

  2. Mesenchymal stem cells induce T-cell tolerance and protect the preterm brain after global hypoxia-ischemia.

    Directory of Open Access Journals (Sweden)

    Reint K Jellema

    Full Text Available Hypoxic-ischemic encephalopathy (HIE in preterm infants is a severe disease for which no curative treatment is available. Cerebral inflammation and invasion of activated peripheral immune cells have been shown to play a pivotal role in the etiology of white matter injury, which is the clinical hallmark of HIE in preterm infants. The objective of this study was to assess the neuroprotective and anti-inflammatory effects of intravenously delivered mesenchymal stem cells (MSC in an ovine model of HIE. In this translational animal model, global hypoxia-ischemia (HI was induced in instrumented preterm sheep by transient umbilical cord occlusion, which closely mimics the clinical insult. Intravenous administration of 2 x 10(6 MSC/kg reduced microglial proliferation, diminished loss of oligodendrocytes and reduced demyelination, as determined by histology and Diffusion Tensor Imaging (DTI, in the preterm brain after global HI. These anti-inflammatory and neuroprotective effects of MSC were paralleled by reduced electrographic seizure activity in the ischemic preterm brain. Furthermore, we showed that MSC induced persistent peripheral T-cell tolerance in vivo and reduced invasion of T-cells into the preterm brain following global HI. These findings show in a preclinical animal model that intravenously administered MSC reduced cerebral inflammation, protected against white matter injury and established functional improvement in the preterm brain following global HI. Moreover, we provide evidence that induction of T-cell tolerance by MSC might play an important role in the neuroprotective effects of MSC in HIE. This is the first study to describe a marked neuroprotective effect of MSC in a translational animal model of HIE.

  3. Electrical stimulation of schwann cells promotes sustained increases in neurite outgrowth.

    Science.gov (United States)

    Koppes, Abigail N; Nordberg, Andrea L; Paolillo, Gina M; Goodsell, Nicole M; Darwish, Haley A; Zhang, Linxia; Thompson, Deanna M

    2014-02-01

    Endogenous electric fields are instructive during embryogenesis by acting to direct cell migration, and postnatally, they can promote axonal growth after injury (McCaig 1991, Al-Majed 2000). However, the mechanisms for these changes are not well understood. Application of an appropriate electrical stimulus may increase the rate and success of nerve repair by directly promoting axonal growth. Previously, DC electrical stimulation at 50 mV/mm (1 mA, 8 h duration) was shown to promote neurite outgrowth and a more pronounced effect was observed if both peripheral glia (Schwann cells) and neurons were co-stimulated. If electrical stimulation is delivered to an injury site, both the neurons and all resident non-neuronal cells [e.g., Schwann cells, endothelial cells, fibroblasts] will be treated and this biophysical stimuli can influence axonal growth directly or indirectly via changes to the resident, non-neuronal cells. In this work, non-neuronal cells were electrically stimulated, and changes in morphology and neuro-supportive cells were evaluated. Schwann cell response (morphology and orientation) was examined after an 8 h stimulation over a range of DC fields (0-200 mV/mm, DC 1 mA), and changes in orientation were observed. Electrically prestimulating Schwann cells (50 mV/mm) promoted 30% more neurite outgrowth relative to co-stimulating both Schwann cells with neurons, suggesting that electrical stimulation modifies Schwann cell phenotype. Conditioned medium from the electrically prestimulated Schwann cells promoted a 20% increase in total neurite outgrowth and was sustained for 72 h poststimulation. An 11-fold increase in nerve growth factor but not brain-derived neurotrophic factor or glial-derived growth factor was found in the electrically prestimulated Schwann cell-conditioned medium. No significant changes in fibroblast or endothelial morphology and neuro-supportive behavior were observed poststimulation. Electrical stimulation is widely used in

  4. DAF-16 and Δ9 desaturase genes promote cold tolerance in long-lived Caenorhabditis elegans age-1 mutants.

    Directory of Open Access Journals (Sweden)

    Fiona R Savory

    Full Text Available In Caenorhabditis elegans, mutants of the conserved insulin/IGF-1 signalling (IIS pathway are long-lived and stress resistant due to the altered expression of DAF-16 target genes such as those involved in cellular defence and metabolism. The three Δ(9 desaturase genes, fat-5, fat-6 and fat-7, are included amongst these DAF-16 targets, and it is well established that Δ(9 desaturase enzymes play an important role in survival at low temperatures. However, no assessment of cold tolerance has previously been reported for IIS mutants. We demonstrate that long-lived age-1(hx546 mutants are remarkably resilient to low temperature stress relative to wild type worms, and that this is dependent upon daf-16. We also show that cold tolerance following direct transfer to low temperatures is increased in wild type worms during the facultative, daf-16 dependent, dauer stage. Although the cold tolerant phenotype of age-1(hx546 mutants is predominantly due to the Δ(9 desaturase genes, additional transcriptional targets of DAF-16 are also involved. Surprisingly, survival of wild type adults following a rapid temperature decline is not dependent upon functional daf-16, and cellular distributions of a DAF-16::GFP fusion protein indicate that DAF-16 is not activated during low temperature stress. This suggests that cold-induced physiological defences are not specifically regulated by the IIS pathway and DAF-16, but expression of DAF-16 target genes in IIS mutants and dauers is sufficient to promote cross tolerance to low temperatures in addition to other forms of stress.

  5. Tolerance induction between two different strains of parental mice prevents graft-versus-host disease in haploidentical hematopoietic stem cell transplantation to F1 mice

    International Nuclear Information System (INIS)

    Guo, Yixian; Zhang, Lanfang; Wan, Suigui; Sun, Xuejing; Wu, Yongxia; Yu, Xue-Zhong; Xia, Chang-Qing

    2014-01-01

    Highlights: • Injection of UVB-irradiated iDCs induces alloantigen tolerance. • This alloantigen tolerance may be associated regulatory T cell induction. • Tolerant mice serve as bone marrow donors reduces GVHD to their F1 recipients in allo-HSCT. • Tolerance is maintained in F1 recipients for long time post HSCT. - Abstract: Haploidentical hematopoietic stem cell transplantation (Haplo-HSCT) has been employed worldwide in recent years and led to favorable outcome in a group of patients who do not have human leukocyte antigen (HLA)-matched donors. However, the high incidence of severe graft-versus-host disease (GVHD) is a major problem for Haplo-HSCT. In the current study, we performed a proof of concept mouse study to test whether induction of allogeneic tolerance between two different parental strains was able to attenuate GVHD in Haplo-HSCT to the F1 mice. We induced alloantigen tolerance in C3H mice (H-2k) using ultraviolet B (UVB) irradiated immature dendritic cells (iDCs) derived from the cultures of Balb/c bone marrow cells. Then, we performed Haplo-HSCT using tolerant C3H mice as donors to F1 mice (C3H × Balb/c). The results demonstrated that this approach markedly reduced GVHD-associated death and significantly prolonged the survival of recipient mice in contrast to the groups with donors (C3H mice) that received infusion of non-UVB-irradiated DCs. Further studies showed that there were enhanced Tregs in the tolerant mice and alloantigen-specific T cell response was skewed to more IL-10-producing T cells, suggesting that these regulatory T cells might have contributed to the attenuation of GVHD. This study suggests that it is a feasible approach to preventing GVHD in Haplo-HSCT in children by pre-induction of alloantigen tolerance between the two parents. This concept may also lead to more opportunities in cell-based immunotherapy for GVHD post Haplo-HSCT

  6. Tolerance induction between two different strains of parental mice prevents graft-versus-host disease in haploidentical hematopoietic stem cell transplantation to F1 mice

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Yixian; Zhang, Lanfang; Wan, Suigui; Sun, Xuejing; Wu, Yongxia [Department of Hematology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); Yu, Xue-Zhong [Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, SC 29425 (United States); Xia, Chang-Qing, E-mail: cqx65@yahoo.com [Department of Hematology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China)

    2014-04-18

    Highlights: • Injection of UVB-irradiated iDCs induces alloantigen tolerance. • This alloantigen tolerance may be associated regulatory T cell induction. • Tolerant mice serve as bone marrow donors reduces GVHD to their F1 recipients in allo-HSCT. • Tolerance is maintained in F1 recipients for long time post HSCT. - Abstract: Haploidentical hematopoietic stem cell transplantation (Haplo-HSCT) has been employed worldwide in recent years and led to favorable outcome in a group of patients who do not have human leukocyte antigen (HLA)-matched donors. However, the high incidence of severe graft-versus-host disease (GVHD) is a major problem for Haplo-HSCT. In the current study, we performed a proof of concept mouse study to test whether induction of allogeneic tolerance between two different parental strains was able to attenuate GVHD in Haplo-HSCT to the F1 mice. We induced alloantigen tolerance in C3H mice (H-2k) using ultraviolet B (UVB) irradiated immature dendritic cells (iDCs) derived from the cultures of Balb/c bone marrow cells. Then, we performed Haplo-HSCT using tolerant C3H mice as donors to F1 mice (C3H × Balb/c). The results demonstrated that this approach markedly reduced GVHD-associated death and significantly prolonged the survival of recipient mice in contrast to the groups with donors (C3H mice) that received infusion of non-UVB-irradiated DCs. Further studies showed that there were enhanced Tregs in the tolerant mice and alloantigen-specific T cell response was skewed to more IL-10-producing T cells, suggesting that these regulatory T cells might have contributed to the attenuation of GVHD. This study suggests that it is a feasible approach to preventing GVHD in Haplo-HSCT in children by pre-induction of alloantigen tolerance between the two parents. This concept may also lead to more opportunities in cell-based immunotherapy for GVHD post Haplo-HSCT.

  7. Fetal liver stromal cells promote hematopoietic cell expansion

    International Nuclear Information System (INIS)

    Zhou, Kun; Hu, Caihong; Zhou, Zhigang; Huang, Lifang; Liu, Wenli; Sun, Hanying

    2009-01-01

    Future application of hematopoietic stem and progenitor cells (HSPCs) in clinical therapies largely depends on their successful expansion in vitro. Fetal liver (FL) is a unique hematopoietic organ in which hematopoietic cells markedly expand in number, but the mechanisms involved remain unclear. Stromal cells (StroCs) have been suggested to provide a suitable cellular environment for in vitro expansion of HSPCs. In this study, murine StroCs derived from FL at E14.5, with a high level of Sonic hedgehog (Shh) and Wnt expression, were found to have an increased ability to support the proliferation of HSPCs. This effect was inhibited by blocking Shh signaling. Supplementation with soluble Shh-N promoted the proliferation of hematopoietic cells by activating Wnt signaling. Our findings suggest that FL-derived StroCs support proliferation of HSPCs via Shh inducing an autocrine Wnt signaling loop. The use of FL-derived StroCs and regulation of the Shh pathway might further enhance HPSC expansion.

  8. Collagen Promotes Higher Adhesion, Survival and Proliferation of Mesenchymal Stem Cells.

    Directory of Open Access Journals (Sweden)

    Chinnapaka Somaiah

    Full Text Available Mesenchymal stem cells (MSC can differentiate into several cell types and are desirable candidates for cell therapy and tissue engineering. However, due to poor cell survival, proliferation and differentiation in the patient, the therapy outcomes have not been satisfactory. Although several studies have been done to understand the conditions that promote proliferation, differentiation and migration of MSC in vitro and in vivo, still there is no clear understanding on the effect of non-cellular bio molecules. Of the many factors that influence the cell behavior, the immediate cell microenvironment plays a major role. In this context, we studied the effect of extracellular matrix (ECM proteins in controlling cell survival, proliferation, migration and directed MSC differentiation. We found that collagen promoted cell proliferation, cell survival under stress and promoted high cell adhesion to the cell culture surface. Increased osteogenic differentiation accompanied by high active RHOA (Ras homology gene family member A levels was exhibited by MSC cultured on collagen. In conclusion, our study shows that collagen will be a suitable matrix for large scale production of MSC with high survival rate and to obtain high osteogenic differentiation for therapy.

  9. Tolerance of Escherichia coli to fluoroquinolone antibiotics depends on specific components of the SOS response pathway.

    Science.gov (United States)

    Theodore, Alyssa; Lewis, Kim; Vulic, Marin

    2013-12-01

    Bacteria exposed to bactericidal fluoroquinolone (FQ) antibiotics can survive without becoming genetically resistant. Survival of these phenotypically resistant cells, commonly called "persisters," depends on the SOS gene network. We have examined mutants in all known SOS-regulated genes to identify functions essential for tolerance in Escherichia coli. The absence of DinG and UvrD helicases and the Holliday junction processing enzymes RuvA and RuvB leads to a decrease in survival. Analysis of the respective mutants indicates that, in addition to repair of double-strand breaks, tolerance depends on the repair of collapsed replication forks and stalled transcription complexes. Mutation in recF results in increased survival, which identifies RecAF recombination as a poisoning mechanism not previously linked to FQ lethality. DinG acts upstream of SOS promoting its induction, whereas RuvAB participates in repair only. UvrD directly promotes all repair processes initiated by FQ-induced damage and prevents RecAF-dependent misrepair, making it one of the crucial SOS functions required for tolerance.

  10. The site of primary T cell activation is a determinant of the balance between intrahepatic tolerance and immunity.

    Science.gov (United States)

    Bowen, David G; Zen, Monica; Holz, Lauren; Davis, Thomas; McCaughan, Geoffrey W; Bertolino, Patrick

    2004-09-01

    Hepatic immunobiology is paradoxical: although the liver possesses unusual tolerogenic properties, it is also the site of effective immune responses against multiple pathogens and subject to immune-mediated pathology. The mechanisms underlying this dichotomy remain unclear. Following previous work demonstrating that the liver may act as a site of primary T cell activation, we demonstrate here that the balance between immunity and tolerance in this organ is established by competition for primary activation of CD8+ T cells between the liver and secondary lymphoid tissues, with the immune outcome determined by the initial site of activation. Using a transgenic mouse model in which antigen is expressed within both liver and lymph nodes, we show that while naive CD8+ T cells activated within the lymph nodes were capable of mediating hepatitis, cells undergoing primary activation within the liver exhibited defective cytotoxic function and shortened half-life and did not mediate hepatocellular injury. The implications of these novel findings may pertain not only to the normal maintenance of peripheral tolerance, but also to hepatic allograft tolerance and the immunopathogenesis of chronic viral hepatitis.

  11. Promoter methylation inhibits BRD7 expression in human nasopharyngeal carcinoma cells

    International Nuclear Information System (INIS)

    Liu, Huaying; Li, Guiyuan; Zhang, Liming; Niu, Zhaoxia; Zhou, Ming; Peng, Cong; Li, Xiayu; Deng, Tan; Shi, Lei; Tan, Yixin

    2008-01-01

    Nasopharyngeal carcinoma (NPC) is a head and neck malignancy with high occurrence in South-East Asia and Southern China. Recent findings suggest that epigenetic inactivation of multiple tumor suppressor genes plays an important role in the tumourigenesis of NPC. BRD7 is a NPC-associated bromodomain gene that exhibits a much higher-level of mRNA expression in normal than in NPC biopsies and cell lines. In this study, we explored the role of DNA methylation in regulation of BRD7 transcription. The presence of CpG islands within BRD7 promoter was predicted by EMBOSS CpGplot and Softberry CpGFinder, respectively. Nested methylation-specific PCR and RT-PCR were employed to detect the methylation status of BRD7 promoter and the mRNA expression of BRD7 gene in tumor cell lines as well as clinical samples. Electrophoretic mobility shift assays (EMSA) and luciferase assay were used to detect the effects of cytosine methylation on the nuclear protein binding to BRD7 promoter. We found that DNA methylation suppresses BRD7 expression in NPC cells. In vitro DNA methylation in NPC cells silenced BRD7 promoter activity and inhibited the binding of the nuclear protein (possibly Sp1) to Sp1 binding sites in the BRD7 promoter. In contrast, inhibition of DNA methylation augments induction of endogenous BRD7 mRNA in NPC cells. We also found that methylation frequency of BRD7 promoter is much higher in the tumor and matched blood samples from NPC patients than in the blood samples from normal individuals. BRD7 promoter demethylation is a prerequisite for high level induction of BRD7 gene expression. DNA methylation of BRD7 promoter might serve as a diagnostic marker in NPC

  12. Infectious Tolerance

    OpenAIRE

    Jonuleit, Helmut; Schmitt, Edgar; Kakirman, Hacer; Stassen, Michael; Knop, Jürgen; Enk, Alexander H.

    2002-01-01

    Regulatory CD4+CD25+ T cells (Treg) are mandatory for maintaining immunologic self-tolerance. We demonstrate that the cell-cell contact–mediated suppression of conventional CD4+ T cells by human CD25+ Treg cells is fixation resistant, independent from membrane-bound TGF-β but requires activation and protein synthesis of CD25+ Treg cells. Coactivation of CD25+ Treg cells with Treg cell–depleted CD4+ T cells results in anergized CD4+ T cells that in turn inhibit the activation of conventional, ...

  13. Cadmium promotes the proliferation of triple-negative breast cancer cells through EGFR-mediated cell cycle regulation

    International Nuclear Information System (INIS)

    Wei, Zhengxi; Song, Xiulong; Shaikh, Zahir A.

    2015-01-01

    Cadmium (Cd) is a carcinogenic metal which is implicated in breast cancer by epidemiological studies. It is reported to promote breast cancer cell growth in vitro through membrane receptors. The study described here examined Cd-mediated growth of non-metastatic human breast cancer derived cells that lack receptors for estrogen, progesterone, and HER2. Treatment of triple-negative HCC 1937 cells with 0.1–0.5 μM Cd increased cell growth by activation of AKT and ERK. Accelerated cell cycle progression was achieved by increasing the levels of cyclins A, B, and E, as well as those of CDKs 1 and 2. Although triple negative cells lack estrogen receptor, they express high levels of EGFR. Therefore, further studies on HCC 1937 and another triple-negative cell line, HCC 38, were conducted using specific siRNA and an inhibitor of EGFR to determine whether EGFR was responsible for mediating the effect of Cd. The results revealed that in both cell types EGFR was not only activated upon Cd treatment, but was also essential for the downstream activation of AKT and ERK. Based on these observations, it is concluded that, in breast cancer cells lacking estrogen receptor, sub-micromolar concentration of Cd can promote cell proliferation. Furthermore, that EGFR plays a critical role in this process. - Highlights: • Sub-micromolar concentrations of Cd promote cell growth in breast cancer cells that lack ER, PR, and HER2. • The increase in cell number is not due to reduction in apoptosis. • Growth promotion involves AKT and ERK signaling and downstream stimulation of cell cycle progression. • Initiation of cell growth by Cd occurs at the cell membrane and requires the activation of EGFR.

  14. Isolation of a strong Arabidopsis guard cell promoter and its potential as a research tool

    Science.gov (United States)

    Yang, Yingzhen; Costa, Alex; Leonhardt, Nathalie; Siegel, Robert S; Schroeder, Julian I

    2008-01-01

    Background A common limitation in guard cell signaling research is that it is difficult to obtain consistent high expression of transgenes of interest in Arabidopsis guard cells using known guard cell promoters or the constitutive 35S cauliflower mosaic virus promoter. An additional drawback of the 35S promoter is that ectopically expressing a gene throughout the organism could cause pleiotropic effects. To improve available methods for targeted gene expression in guard cells, we isolated strong guard cell promoter candidates based on new guard cell-specific microarray analyses of 23,000 genes that are made available together with this report. Results A promoter, pGC1(At1g22690), drove strong and relatively specific reporter gene expression in guard cells including GUS (beta-glucuronidase) and yellow cameleon YC3.60 (GFP-based calcium FRET reporter). Reporter gene expression was weaker in immature guard cells. The expression of YC3.60 was sufficiently strong to image intracellular Ca2+ dynamics in guard cells of intact plants and resolved spontaneous calcium transients in guard cells. The GC1 promoter also mediated strong reporter expression in clustered stomata in the stomatal development mutant too-many-mouths (tmm). Furthermore, the same promoter::reporter constructs also drove guard cell specific reporter expression in tobacco, illustrating the potential of this promoter as a method for high level expression in guard cells. A serial deletion of the promoter defined a guard cell expression promoter region. In addition, anti-sense repression using pGC1 was powerful for reducing specific GFP gene expression in guard cells while expression in leaf epidermal cells was not repressed, demonstrating strong cell-type preferential gene repression. Conclusion The pGC1 promoter described here drives strong reporter expression in guard cells of Arabidopsis and tobacco plants. It provides a potent research tool for targeted guard cell expression or gene silencing. It is also

  15. T-cell activation promotes tumorigenesis in inflammation-associated cancer

    Directory of Open Access Journals (Sweden)

    Lairmore Michael

    2009-12-01

    Full Text Available Abstract Chronic inflammation has long been associated with a wide range of malignancies, is now widely accepted as a risk factor for development of cancer, and has been implicated as a promoter of a variety of cancers including hematopoietic malignancies. We have described a mouse model uniquely suited to examine the link between inflammation and lymphoma in which the Tax oncogene, expressed in activated T and NK cells, perpetuates chronic inflammation that begins as microscopic intraepithelial lesions and develops into inflammatory nodules, subcutaneous tumors, and large granular lymphocytic leukemia. The use of bioluminescent imaging in these mice has expanded our ability to interrogate aspects of inflammation and tumorigenesis non-invasively. Here we demonstrate that bioluminescence induction in these mice correlated with inflammation resulting from wounding, T cell activation, and exposure to chemical agents. In experiments in which long-term effects of inflammation on disease outcome were monitored, the development of lymphoma was promoted by an inflammatory stimulus. Finally we demonstrated that activation of T-cells in T-cell receptor (TCR transgenic TAX-LUC animals dramatically exacerbated the development of subcutaneous TCR- CD16+ LGL tumors. The role of activated T-cells and acquired immunity in inflammation-associated cancers is broadly applicable to hematopoietic malignancies, and we propose these mice will be of use in dissecting mechanisms by which activated T-cells promote lymphomagenesis in vivo.

  16. Microenvironmental cues enhance mesenchymal stem cell-mediated immunomodulation and regulatory T-cell expansion.

    Science.gov (United States)

    Kadle, Rohini L; Abdou, Salma A; Villarreal-Ponce, Alvaro P; Soares, Marc A; Sultan, Darren L; David, Joshua A; Massie, Jonathan; Rifkin, William J; Rabbani, Piul; Ceradini, Daniel J

    2018-01-01

    Mesenchymal stem cells (MSCs) are known to both have powerful immunosuppressive properties and promote allograft tolerance. Determining the environmental oxygen tension and inflammatory conditions under which MSCs are optimally primed for this immunosuppressive function is essential to their utilization in promoting graft tolerance. Of particular interest is the mechanisms governing the interaction between MSCs and regulatory T cells (Tregs), which is relatively unknown. We performed our experiments utilizing rat bone marrow derived MSCs. We observed that priming MSCs in hypoxia promotes maintenance of stem-like characteristics, with greater expression of typical MSC cell-surface markers, increased proliferation, and maintenance of differentiation potential. Addition of autologous MSCs to CD4+/allogeneic endothelial cell (EC) co-culture increases regulatory T cell (Treg) proliferation, which is further enhanced when MSCs are primed in hypoxia. Furthermore, MSC-mediated Treg expansion does not require direct cell-cell contact. The expression of indolamine 2,3-dioxygenase, a mediator of MSC immunomodulation, increases when MSCs are primed in hypoxia, and inhibition of IDO significantly decreases the expansion of Tregs. Priming with inflammatory cytokines IFNγ and TNFα increases also expression of markers associated with MSC immunomodulatory function, but decreases MSC proliferation. The expression of IDO also increases when MSCs are primed with inflammatory cytokines. However, there is no increase in Treg expansion when MSCs are primed with IFNγ, suggesting an alternate mechanism for inflammatory-stimulated MSC immunomodulation. Overall, these results suggest that MSCs primed in hypoxia or inflammatory conditions are optimally primed for immunosuppressive function. These results provide a clearer picture of how to enhance MSC immunomodulation for clinical use.

  17. Autoreactive T Cells and Chronic Fungal Infection Drive Esophageal Carcinogenesis

    Science.gov (United States)

    Zhu, Feng; Willette-Brown, Jami; Song, Na-Young; Lomada, Dakshayani; Song, Yongmei; Xue, Liyan; Gray, Zane; Zhao, Zitong; Davis, Sean R.; Sun, Zhonghe; Zhang, Peilin; Wu, Xiaolin; Zhan, Qimin; Richie, Ellen R.; Hu, Yinling

    2018-01-01

    SUMMARY Humans with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), a T cell–driven autoimmune disease caused by impaired central tolerance, are susceptible to developing chronic fungal infection and esophageal squamous cell carcinoma (ESCC). However, the relationship between autoreactive T cells and chronic fungal infection in ESCC development remains unclear. We find that kinase-dead Ikkα knockin mice develop phenotypes reminiscent of APECED, including impaired central tolerance, autoreactive T cells, chronic fungal infection, and ESCCs expressing specific human ESCC markers. Using this model, we investigated the potential link between ESCC and fungal infection. Autoreactive CD4 T cells permit fungal infection and incite tissue injury and inflammation. Antifungal treatment or depletion of autoreactive CD4 T cells rescues, whereas oral fungal administration promotes, ESCC development. Inhibition of inflammation or EGFR activity decreases fungal burden. Importantly, fungal infection is highly associated with ESCCs in non-autoimmune human patients. Therefore, autoreactive T cells and chronic fungal infection, fostered by inflammation and epithelial injury, promote ESCC development. PMID:28407484

  18. Methylation of the ATM promoter in glioma cells alters ionizing radiation sensitivity

    International Nuclear Information System (INIS)

    Roy, Kanaklata; Wang, Lilin; Makrigiorgos, G. Mike; Price, Brendan D.

    2006-01-01

    Glioblastomas are among the malignancies most resistant to radiation therapy. In contrast, cells lacking the ATM protein are highly sensitive to ionizing radiation. The relationship between ATM protein expression and radiosensitivity in 3 glioma cell lines was examined. T98G cells exhibited normal levels of ATM protein, whereas U118 and U87 cells had significantly lower levels of ATM and increased (>2-fold) sensitivity to ionizing radiation compared to T98G cells. The ATM promoter was methylated in U87 cells. Demethylation by azacytidine treatment increased ATM protein levels in the U87 cells and decreased their radiosensitivity. In contrast, the ATM promoter in U118 cells was not methylated. Further, expression of exogenous ATM did not significantly alter the radiosensitivity of U118 cells. ATM expression is therefore heterogeneous in the glioma cells examined. In conclusion, methylation of the ATM promoter may account for the variable radiosensitivity and heterogeneous ATM expression in a fraction of glioma cells

  19. Clonorchis sinensis infestation promotes three-dimensional aggregation and invasion of cholangiocarcinoma cells.

    Directory of Open Access Journals (Sweden)

    Jihee Won

    Full Text Available Numerous experimental and epidemiological studies have demonstrated a correlation between Clonorchis sinensis (C. sinensis infestation and cholangiocarcinoma (CCA. However, the role of C. sinensis in the increased invasiveness and proliferation involved in the malignancy of CCA has not been addressed yet. Here, we investigated the possibility that C. sinensis infestation promotes expression of focal and cell-cell adhesion proteins in CCA cells and secretion of matrix metalloproteinases (MMPs. Adhesion proteins help maintain cell aggregates, and MMPs promote the three-dimensional invasion of cells into the neighboring extracellular matrix (ECM. Using a novel microfluidic assay, we quantitatively addressed the role of excretory-secretory products (ESPs gradients from C. sinensis in promoting the invasion of cells into the neighboring ECM.

  20. Interpreting phenotypic antibiotic tolerance and persister cells as evolution via epigenetic inheritance.

    Science.gov (United States)

    Day, Troy

    2016-04-01

    Epigenetic inheritance is the transmission of nongenetic material such as gene expression levels, RNA and other biomolecules from parents to offspring. There is a growing realization that such forms of inheritance can play an important role in evolution. Bacteria represent a prime example of epigenetic inheritance because a large array of cellular components is transmitted to offspring, in addition to genetic material. Interestingly, there is an extensive and growing empirical literature showing that many bacteria can form 'persister' cells that are phenotypically resistant or tolerant to antibiotics, but most of these results are not interpreted within the context of epigenetic inheritance. Instead, persister cells are usually viewed as a genetically encoded bet-hedging strategy that has evolved in response to a fluctuating environment. Here I show, using a relatively simple model, that many of these empirical findings can be more simply understood as arising from a combination of epigenetic inheritance and cellular noise. I therefore suggest that phenotypic drug tolerance in bacteria might represent one of the best-studied examples of evolution under epigenetic inheritance. © 2016 John Wiley & Sons Ltd.

  1. A20 is critical for the induction of Pam3CSK4-tolerance in monocytic THP-1 cells.

    Directory of Open Access Journals (Sweden)

    Jinyue Hu

    Full Text Available A20 functions to terminate Toll-like receptor (TLR-induced immune response, and play important roles in the induction of lipopolysacchride (LPS-tolerance. However, the molecular mechanism for Pam3CSK4-tolerance is uncertain. Here we report that TLR1/2 ligand Pam3CSK4 induced tolerance in monocytic THP-1 cells. The pre-treatment of THP-1 cells with Pam3CSK4 down-regulated the induction of pro-inflammatory cytokines induced by Pam3CSK4 re-stimulation. Pam3CSK4 pre-treatment also down-regulated the signaling transduction of JNK, p38 and NF-κB induced by Pam3CSK4 re-stimulation. The activation of TLR1/2 induced a rapid and robust up-regulation of A20, suggesting that A20 may contribute to the induction of Pam3CSK4-tolerance. This hypothesis was proved by the observation that the over-expression of A20 by gene transfer down-regulated Pam3CSK4-induced inflammatory responses, and the down-regulation of A20 by RNA interference inhibited the induction of tolerance. Moreover, LPS induced a significant up-regulation of A20, which contributed to the induction of cross-tolerance between LPS and Pam3CSK4. A20 was also induced by the treatment of THP-1 cells with TNF-α and IL-1β. The pre-treatment with TNF-α and IL-1β partly down-regulated Pam3CSK4-induced activation of MAPKs. Furthermore, pharmacologic inhibition of GSK3 signaling down-regulated Pam3CSK4-induced A20 expression, up-regulated Pam3CSK4-induced inflammatory responses, and partly reversed Pam3CSK4 pre-treatment-induced tolerance, suggesting that GSK3 is involved in TLR1/2-induced tolerance by up-regulation of A20 expression. Taken together, these results indicated that A20 is a critical regulator for TLR1/2-induced pro-inflammatory responses.

  2. Chitosan nanoparticles affect acid tolerance response in adhered cells of strpetococcus mutans

    DEFF Research Database (Denmark)

    Neilands, Julia; Sutherland, Duncan S; Resin, Anton

    2011-01-01

    In this study we evaluated the effect of chitosan nanoparticles on the acid tolerance response (ATR) of adhered Streptococcus mutans. An ATR was induced by exposing S. mutans to pH 5.5 for 2 h and confirmed by exposing the acid-adapted cells to pH 3.5 for 30 min, with the majority of cells...... appearing viable according to the LIVE/DEAD (R) technique. However, when chitosan nanoparticles were present during the exposure to pH 5.5, no ATR occurred as most cells appeared dead after the pH 3.5 shock. We conclude that the chitosan nanoparticles tested had the ability to hinder ATR induction...

  3. Low dose perfluorooctanoate exposure promotes cell proliferation in a human non-tumor liver cell line

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hongxia; Cui, Ruina [Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China); Guo, Xuejiang [State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 210029 (China); Hu, Jiayue [Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China); Dai, Jiayin, E-mail: daijy@ioz.ac.cn [Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China)

    2016-08-05

    Highlights: • Differential expression of proteins induced by PFOA in HL-7702 was identified. • Most of the differentially expressed proteins are related to cell proliferation. • A low dose of PFOA stimulates HL-7702 cell proliferation. • A high dose of PFOA inhibits HL-7702 cell proliferation. - Abstract: Perfluorooctanoate (PFOA) is a well-known persistent organic pollutant widely found in the environment, wildlife and humans. Medical surveillance and experimental studies have investigated the potential effects of PFOA on human livers, but the hepatotoxicity of PFOA on humans and its underlying mechanism remain to be clarified. We exposed a human liver cell line (HL-7702) to 50 μM PFOA for 48 h and 96 h, and identified 111 significantly differentially expressed proteins by iTRAQ analysis. A total of 46 proteins were related to cell proliferation and apoptosis. Through further analysis of the cell cycle, apoptosis and their related proteins, we found that low doses of PFOA (50–100 μM) promoted cell proliferation and numbers by promoting cells from the G1 to S phases, whereas high doses of PFOA (200–400 μM) led to reduced HL-7702 cell numbers compared with that of the control mainly due to cell cycle arrest in the G0/G1 phase. To our knowledge, this is the first report on the promotion of cell cycle progression in human cells following PFOA exposure.

  4. Low dose perfluorooctanoate exposure promotes cell proliferation in a human non-tumor liver cell line

    International Nuclear Information System (INIS)

    Zhang, Hongxia; Cui, Ruina; Guo, Xuejiang; Hu, Jiayue; Dai, Jiayin

    2016-01-01

    Highlights: • Differential expression of proteins induced by PFOA in HL-7702 was identified. • Most of the differentially expressed proteins are related to cell proliferation. • A low dose of PFOA stimulates HL-7702 cell proliferation. • A high dose of PFOA inhibits HL-7702 cell proliferation. - Abstract: Perfluorooctanoate (PFOA) is a well-known persistent organic pollutant widely found in the environment, wildlife and humans. Medical surveillance and experimental studies have investigated the potential effects of PFOA on human livers, but the hepatotoxicity of PFOA on humans and its underlying mechanism remain to be clarified. We exposed a human liver cell line (HL-7702) to 50 μM PFOA for 48 h and 96 h, and identified 111 significantly differentially expressed proteins by iTRAQ analysis. A total of 46 proteins were related to cell proliferation and apoptosis. Through further analysis of the cell cycle, apoptosis and their related proteins, we found that low doses of PFOA (50–100 μM) promoted cell proliferation and numbers by promoting cells from the G1 to S phases, whereas high doses of PFOA (200–400 μM) led to reduced HL-7702 cell numbers compared with that of the control mainly due to cell cycle arrest in the G0/G1 phase. To our knowledge, this is the first report on the promotion of cell cycle progression in human cells following PFOA exposure.

  5. Drought-Tolerant Plant Growth-Promoting Rhizobacteria Associated with Foxtail Millet in a Semi-arid Agroecosystem and Their Potential in Alleviating Drought Stress

    Directory of Open Access Journals (Sweden)

    Xuguang Niu

    2018-01-01

    Full Text Available The application of plant growth promoting rhizobacteria (PGPR to agro-ecosystems is considered to have the potential for improving plant growth in extreme environments featured by water shortage. Herein, we isolated bacterial strains from foxtail millet (Setaria italica L., a drought-tolerant crop cultivated in semiarid regions in the northeast of China. Four isolates were initially selected for their ability to produce ACC deaminase as well as drought tolerance. The isolates were identified as Pseudomonas fluorescens, Enterobacter hormaechei, and Pseudomonas migulae on the basis of 16S rRNA sequence analysis. All of these drought-tolerant isolates were able to produce EPS (exopolysaccharide. Inoculation with these strains stimulated seed germination and seedling growth under drought stress. Pseudomonas fluorescens DR7 showed the highest level of ACC deaminase and EPS-producing activity. DR7 could efficiently colonize the root adhering soil, increased soil moisture, and enhance the root adhering soil/root tissue ratio. These results suggest drought tolerant PGPR from foxtail millet could enhance plant growth under drought stress conditions and serve as effective bioinoculants to sustain agricultural production in arid regions.

  6. Ethanol tolerant precious metal free cathode catalyst for alkaline direct ethanol fuel cells

    International Nuclear Information System (INIS)

    Grimmer, Ilena; Zorn, Paul; Weinberger, Stephan; Grimmer, Christoph; Pichler, Birgit; Cermenek, Bernd; Gebetsroither, Florian; Schenk, Alexander; Mautner, Franz-Andreas

    2017-01-01

    Highlights: • Selective ORR catalysts are presented for alkaline direct ethanol fuel cells. • Perovskite based cathode catalysts show high tolerance toward ethanol. • A membrane-free alkaline direct ethanol fuel cell is presented. - Abstract: La 0.7 Sr 0.3 (Fe 0.2 Co 0.8 )O 3 and La 0.7 Sr 0.3 MnO 3 −based cathode catalysts are synthesized by the sol-gel method. These perovskite cathode catalysts are tested in half cell configuration and compared to MnO 2 as reference material in alkaline direct ethanol fuel cells (ADEFCs). The best performing cathode is tested in single cell setup using a standard carbon supported Pt 0.4 Ru 0.2 based anode. A backside Luggin capillary is used in order to register the anode potential during all measurements. Characteristic processes of the electrodes are investigated using electrochemical impedance spectroscopy. Physical characterizations of the perovskite based cathode catalysts are performed with a scanning electron microscope (SEM) and by X-ray diffraction showing phase pure materials. In half cell setup, La 0.7 Sr 0.3 MnO 3 shows the highest tolerance toward ethanol with a performance of 614 mA cm −2 at 0.65 V vs. RHE in 6 M KOH and 1 M EtOH at RT. This catalyst outperforms the state-of-the-art precious metal-free MnO 2 catalyst in presence of ethanol. In fuel cell setup, the peak power density is 27.6 mW cm −2 at a cell voltage of 0.345 V and a cathode potential of 0.873 V vs. RHE.

  7. Mechanisms of cardiac transplantation tolerance in syngeneic rat radiation chimeras

    International Nuclear Information System (INIS)

    Moran, T.M.

    1981-01-01

    Seventy-five percent of adult LEW rats, lethally irradiated (860 R), transplanted with an RT-1 incompatible Wistar Furth (WF) heart or kidney and repopulated on day 2 with a 4:1 mixture of syngeneic thymus and bone marrow cells accept these grafts. In order to look at the ability of animals tolerating WF organ grafts to respond against WF spleen cells in vitro we developed a rat mixed lymphocyte culture. Tolerant animals were tested for the ability to respond to donor antigens and approximately half of the 50 animals tested, were responsive. We attempted to demonstrate suppressor cells which might be responsible for maintaining tolerance in the nonresponders. Neither mixtures at the sensitization or the effector level suggested that tolerance was being maintained by a suppressor cell. An in vivo assay which tested the ability of various cell populations to affect the survival of allogeneic hearts transplanted into sublethally irradiated recipients was then employed. Tolerance is induced using this protocol in a manner similar or identical to tolerance produced by neonatal injection of antigen. This tolerance might be maintained in part by suppressor cells which prevents the generation of clones of cells reactive against the heart donor. The mechanism of tolerance in rats with demonstrable clones of reactive cells remains to be determined

  8. CacyBP/SIP promotes the proliferation of colon cancer cells.

    Directory of Open Access Journals (Sweden)

    Huihong Zhai

    Full Text Available CacyBP/SIP is a component of the ubiquitin pathway and is overexpressed in several transformed tumor tissues, including colon cancer, which is one of the most common cancers worldwide. It is unknown whether CacyBP/SIP promotes the proliferation of colon cancer cells. This study examined the expression level, subcellular localization, and binding activity of CacyBP/SIP in human colon cancer cells in the presence and absence of the hormone gastrin. We found that CacyBP/SIP was expressed in a high percentage of colon cancer cells, but not in normal colonic surface epithelium. CacyBP/SIP promoted the cell proliferation of colon cancer cells under both basal and gastrin stimulated conditions as shown by knockdown studies. Gastrin stimulation triggered the translocation of CacyBP/SIP to the nucleus, and enhanced interaction between CacyBP/SIP and SKP1, a key component of ubiquitination pathway which further mediated the proteasome-dependent degradation of p27kip1 protein. The gastrin induced reduction in p27kip1 was prevented when cells were treated with the proteasome inhibitor MG132. These results suggest that CacyBP/SIP may be promoting growth of colon cancer cells by enhancing ubiquitin-mediated degradation of p27kip1.

  9. Tolerance to environmental desiccation in moss sperm.

    Science.gov (United States)

    Shortlidge, Erin E; Rosenstiel, Todd N; Eppley, Sarah M

    2012-05-01

    • Sexual reproduction in mosses requires that sperm be released freely into the environment before finding and fertilizing a receptive female. After release from the male plant, moss sperm may experience a range of abiotic stresses; however, few data are available examining stress tolerance of moss sperm and whether there is genetic variation for stress tolerance in this important life stage. • Here, we investigated the effects of environmental desiccation and recovery on the sperm cells of three moss species (Bryum argenteum, Campylopus introflexus, and Ceratodon purpureus). • We found that a fraction of sperm cells were tolerant to environmental desiccation for extended periods (d) and that tolerance did not vary among species. We found that this tolerance occurs irrespective of ambient dehydration conditions, and that the addition of sucrose during dry-down improved cell recovery. Although we observed no interspecific variation, significant variation among individuals within species in sperm cell tolerance to environmental desiccation was observed, suggesting selection could potentially act on this basic reproductive trait. • The observation of desiccation-tolerant sperm in multiple moss species has important implications for understanding bryophyte reproduction, suggesting the presence of a significant, uncharacterized complexity in the ecology of moss mating systems. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

  10. Helios expression in regulatory T cells promotes immunosuppression, angiogenesis and the growth of leukemia cells in pediatric acute lymphoblastic leukemia.

    Science.gov (United States)

    Li, Xue; Li, Dong; Huang, Xiaoyang; Zhou, Panpan; Shi, Qing; Zhang, Bing; Ju, Xiuli

    2018-04-01

    Regulatory T cells (Tregs) characterized by the transcription factor forkhead box P3 (FoxP3) are crucial for maintaining immune tolerance and preventing autoimmunity. However, FoxP3 does not function alone and Helios is considered a potential candidate for defining Treg subsets. In this study, we investigated the expression and function of Helios for identifying Tregs in childhood precursor B-cell acute lymphoblastic leukemia (pre-B ALL). Our results demonstrated that patients with pre-B ALL had a higher percentage of Helios + FoxP3 + CD4 + Tregs. And there was a positive correlation between the expression of Helios and the suppressive function of Tregs, the risk gradation of ALL. Helios in combination with CD4 and FoxP3 may be an effective way to detect functional Tregs in pre-B ALL by promoting the secretion of transforming growth factor (TGF)-β1. Furthermore, Helios + Tregs could regulate angiogenesis in the BM niche of pre-B ALL via the VEGFA/VEGFR2 pathway. We also found Helios + Tregs decreased apoptosis rate of nalm-6 cells by up-regulating the expression of anti-apoptosis protein Bcl-2. In summary, these data strongly imply the physiological importance of Helios expression in Tregs, and suggest that the manipulation of Helios may serve as a novel strategy for cancer immunotherapy. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. B-Cell Activation and Tolerance Mediated by B-Cell Receptor, Toll-Like Receptor, and Survival Signal Crosstalk in SLE Pathogenesis

    Science.gov (United States)

    2017-09-01

    Dec, 2016 "Integrating innate , adaptive, & survival signals to control B cell selection, homeostasis and tolerance" Pasteur Institute of Shanghai...secondary lymphoid tissues. Aging Dis. 2: 361–373. 8. Goenka, R., J. L. Scholz, M. S. Naradikian, and M. P. Cancro. 2014. Memory B cells form in aged...Scholz, and M. P. Cancro. 2011. A B- cell subset uniquely responsive to innate stimuli accumulates in aged mice. Blood 118: 1294–1304. 10. Rubtsov, A

  12. Dietary Fiber and Bacterial SCFA Enhance Oral Tolerance and Protect against Food Allergy through Diverse Cellular Pathways

    Directory of Open Access Journals (Sweden)

    Jian Tan

    2016-06-01

    Full Text Available The incidence of food allergies in western countries has increased dramatically in recent decades. Tolerance to food antigens relies on mucosal CD103+ dendritic cells (DCs, which promote differentiation of regulatory T (Treg cells. We show that high-fiber feeding in mice improved oral tolerance and protected from food allergy. High-fiber feeding reshaped gut microbial ecology and increased the release of short-chain fatty acids (SCFAs, particularly acetate and butyrate. High-fiber feeding enhanced oral tolerance and protected against food allergy by enhancing retinal dehydrogenase activity in CD103+ DC. This protection depended on vitamin A in the diet. This feeding regimen also boosted IgA production and enhanced T follicular helper and mucosal germinal center responses. Mice lacking GPR43 or GPR109A, receptors for SCFAs, showed exacerbated food allergy and fewer CD103+ DCs. Dietary elements, including fiber and vitamin A, therefore regulate numerous protective pathways in the gastrointestinal tract, necessary for immune non-responsiveness to food antigens.

  13. Promoting resuscitation of viable but nonculturable cells of Vibrio harveyi by a resuscitation-promoting factor-like protein YeaZ.

    Science.gov (United States)

    Li, Y; Chen, J; Zhao, M; Yang, Z; Yue, L; Zhang, X

    2017-02-01

    To demonstrate the resuscitation-promoting activities of recombinant YeaZ from Vibrio harveyi SF-1. The gene of resuscitation-promoting factor YeaZ was cloned from genomic DNA of V. harveyi SF-1. The gene was expressed in Escherichia coli, and the expressed protein was purified by Ni 2+ -affinity chromatography. A yeaZ mutant was constructed by using the suicide plasmid pNQ705 with homologous recombination. Disruption of yeaZ did not affect cell growth significantly in 2216 E broth at 28°C. The wild-type and mutant viable but nonculturable (VBNC) cells could be resuscitated by temperature upshift method. In addition, the recombinant YeaZ increased the culturable counts from 1·27 × 10 4  CFU per ml and 1·99 × 10 4 CFU per ml to 2·88 × 10 5  CFU per ml and 4·59 × 10 5 CFU per ml, respectively. After the VBNC cells of wild-type and mutant cells were maintained at 4°C for 120 days, no resuscitation was obtained by temperature upshift method, but addition of the recombinant YeaZ promoted the resuscitation of the wild-type and mutant cells, with the culturable cell counts of 1·13 × 10 3 and 1·44 × 10 3 CFU per ml, respectively. Disruption of yeaZ decreased the virulence of V. harveyi in zebrafish. The lethal dose 50% of the yeaZ null mutant was more than 10-fold higher than that of the wild-type cells. The recombinant YeaZ could efficiently promote resuscitation of the wild-type and mutant cells of V. harveyi from VBNC to culturable state. The protein also promoted resuscitation of the VBNC wild-type and mutant cells, which were maintained at 4°C for 120 days and not recovered by temperature upshift method. Disruption of yeaZ decreased the virulence of V. harveyi in zebrafish. Here, we show clear evidence of a resuscitation-promoting factor YeaZ of V. harveyi and the roles in resuscitation of the VBNC cells and its pathogenicity. © 2016 The Society for Applied Microbiology.

  14. The GARP/Latent TGF-β1 complex on Treg cells modulates the induction of peripherally derived Treg cells during oral tolerance.

    Science.gov (United States)

    Edwards, Justin P; Hand, Timothy W; Morais da Fonseca, Denise; Glass, Deborah D; Belkaid, Yasmine; Shevach, Ethan M

    2016-06-01

    Treg cells can secrete latent TGF-β1 (LTGF-β1), but can also utilize an alternative pathway for transport and expression of LTGF-β1 on the cell surface in which LTGF-β1 is coupled to a distinct LTGF-β binding protein termed glycoprotein A repetitions predominant (GARP)/LRRC32. The function of the GARP/LTGF-β1 complex has remained elusive. Here, we examine in vivo the roles of GARP and TGF-β1 in the induction of oral tolerance. When Foxp3(-) OT-II T cells were transferred to wild-type recipient mice followed by OVA feeding, the conversion of Foxp3(-) to Foxp3(+) OT-II cells was dependent on recipient Treg cells. Neutralization of IL-2 in the recipient mice also abrogated this conversion. The GARP/LTGF-β1 complex on recipient Treg cells, but not dendritic cell-derived TGF-β1, was required for efficient induction of Foxp3(+) T cells and for the suppression of delayed hypersensitivity. Expression of the integrin αvβ8 by Treg cells (or T cells) in the recipients was dispensable for induction of Foxp3 expression. Transient depletion of the bacterial flora enhanced the development of oral tolerance by expanding Treg cells with enhanced expression of the GARP/LTGF-β1 complex. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

  15. Isolation of a strong Arabidopsis guard cell promoter and its potential as a research tool

    Directory of Open Access Journals (Sweden)

    Siegel Robert S

    2008-02-01

    Full Text Available Abstract Background A common limitation in guard cell signaling research is that it is difficult to obtain consistent high expression of transgenes of interest in Arabidopsis guard cells using known guard cell promoters or the constitutive 35S cauliflower mosaic virus promoter. An additional drawback of the 35S promoter is that ectopically expressing a gene throughout the organism could cause pleiotropic effects. To improve available methods for targeted gene expression in guard cells, we isolated strong guard cell promoter candidates based on new guard cell-specific microarray analyses of 23,000 genes that are made available together with this report. Results A promoter, pGC1(At1g22690, drove strong and relatively specific reporter gene expression in guard cells including GUS (beta-glucuronidase and yellow cameleon YC3.60 (GFP-based calcium FRET reporter. Reporter gene expression was weaker in immature guard cells. The expression of YC3.60 was sufficiently strong to image intracellular Ca2+ dynamics in guard cells of intact plants and resolved spontaneous calcium transients in guard cells. The GC1 promoter also mediated strong reporter expression in clustered stomata in the stomatal development mutant too-many-mouths (tmm. Furthermore, the same promoter::reporter constructs also drove guard cell specific reporter expression in tobacco, illustrating the potential of this promoter as a method for high level expression in guard cells. A serial deletion of the promoter defined a guard cell expression promoter region. In addition, anti-sense repression using pGC1 was powerful for reducing specific GFP gene expression in guard cells while expression in leaf epidermal cells was not repressed, demonstrating strong cell-type preferential gene repression. Conclusion The pGC1 promoter described here drives strong reporter expression in guard cells of Arabidopsis and tobacco plants. It provides a potent research tool for targeted guard cell expression or

  16. Allelic imbalance modulates surface expression of the tolerance-inducing HLA-G molecule on primary trophoblast cells

    DEFF Research Database (Denmark)

    Djurisic, S; Teiblum, S; Tolstrup, C K

    2015-01-01

    The HLA-G molecule is expressed on trophoblast cells at the feto-maternal interface, where it interacts with local immune cells, and upholds tolerance against the semi-allogeneic fetus. Aberrant HLA-G expression in the placenta and reduced soluble HLA-G levels are observed in pregnancy complicati...

  17. Naturally occurring tolerance acquisition to foods in previously allergic children is characterized by antigen specificity and associated with increased subsets of regulatory T cells.

    Science.gov (United States)

    Qamar, N; Fishbein, A B; Erickson, K A; Cai, M; Szychlinski, C; Bryce, P J; Schleimer, R P; Fuleihan, R L; Singh, A M

    2015-11-01

    Food allergy affects approximately 6-8% of children, and increasing in prevalence. Some children naturally outgrow their food allergy without intervention, but the mechanisms by which this occurs remain poorly understood. We sought to investigate the role of regulatory T cells in the development of naturally acquired tolerance. Fifty-eight children (1-18 years) with either egg or peanut allergy, recent acquisition of natural tolerance to egg or peanut, or no food allergy were studied. Peripheral blood mononuclear cells (PBMC) from these groups were stimulated with relevant antigen for 48 h and flow cytometry performed to characterize both surface (CD3, CD4, CD25, CD14, CD19, and CD127) and intracellular markers (IL-10, Foxp3, and IL-5). Resting PBMC from naturally tolerant patients had significantly increased CD3+CD4+CD25+CD127loFoxp3+ cells, when compared to allergic or control patients (mean 6.36 vs. 2.37 vs. 2.62%, respectively, P naturally tolerant patients also had increased IL-10-expressing CD25+CD127lo cells (6.33 vs. 1.65 vs. 0.7, P naturally tolerant patients suggests an important role for regulatory T cell subsets in the acquisition of natural tolerance. © 2015 John Wiley & Sons Ltd.

  18. Methylation Status of miR-182 Promoter in Lung Cancer Cell Lines

    Directory of Open Access Journals (Sweden)

    Yongwen LI

    2015-05-01

    Full Text Available Background and objective It has been proven that the abnormal expression of miR-182 was related to the occurrence and development of tumors. The aim of this study is to explore the relationship between the methylation of miR-182 promoter and its expression in lung cancer cell lines. Methods Real-time quantitative PCR and methylation-specific PCR were used to detect the expression level of miR-182 and its promoter methylation status in five lung cancer cell lines (A549, L9981, NL9980, 95C and 95D. DNA sequencing was used to confirm the methylation results. Results The level of miR-182 expression significantly differs among these lung cancer cell lines. The highly metastatic human lung cancer cell lines, namely, A549 and L9981, demonstrate a relatively lower expression level of miR-182 compared with the lowly metastatic human lung cancer cell line 95C. Methylation-specific PCR and DNA sequencing assay results indicate that these lung cancer cell lines present different levels of miR-182 promoter methylation, and the highest methylation level is observed in A549 cells. Furthermore, the expression of miR-182 in these cell lines significantly increases when treated with 10 μM 5’-Aza-dC. Conclusion DNA methylation occurs in the miR-182 promoter region in lung cancer cell lines. This methylation can regulate the expression level of miR-182. Further study must be conducted to explore the function of miR-182 promoter methylation in lung cancer occurrence and development.

  19. The regulatory roles of B cell subsets in transplantation.

    Science.gov (United States)

    Chu, Zhulang; Zou, Weilong; Xu, Yanan; Sun, Qiquan; Zhao, Yong

    2018-02-01

    B cells mediate allograft rejection through antigen presentation, and production of cytokines and antibodies. More and more immunosuppressive agents specifically targeting B cells and plasma cells have been applied in clinical transplantation. However, recent studies have indicated the regulatory roles of B cells. Therefore, it is vital to clarify the different effects of B cell subsets in organ transplantation so that we can completely understand the diverse functions of B cells in transplantation. Areas covered: This review focuses on the regulatory roles of B cells in transplantation. B cell subsets with immune modulation and factors mediating immunosuppressive functions of regulatory B (Breg) cells were analyzed. Therapies targeting B cells and the application of B cells for transplant tolerance induction were discussed. Expert commentary: Besides involving rejection, B cells could also play regulatory roles in transplantation. Breg cells and the related markers may be used to predict the immune tolerant state in transplant recipients. New therapeutic strategies targeting B cells should be explored to promote tolerance induction with less impact on the host's protective immunity in organ transplanted patients.

  20. Plant Growth Promoting Rhizobacteria and Silicon Synergistically Enhance Salinity Tolerance of Mung Bean

    KAUST Repository

    Mahmood, Sajid

    2016-06-17

    The present study explored the eco-friendly approach of utilizing plant-growth-promoting rhizobacteria (PGPR) inoculation and foliar application of silicon (Si) to improve the physiology, growth, and yield of mung bean under saline conditions. We isolated 18 promising PGPR from natural saline soil in Saudi Arabia, and screened them for plant-growth-promoting activities. Two effective strains were selected from the screening trial, and were identified as Enterobacter cloacae and Bacillus drentensis using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry and 16S rRNA gene sequencing techniques, respectively. Subsequently, in a 2-year mung bean field trial, using a randomized complete block design with a split-split plot arrangement, we evaluated the two PGPR strains and two Si levels (1 and 2 kg ha−1), in comparison with control treatments, under three different saline irrigation conditions (3.12, 5.46, and 7.81 dS m−1). The results indicated that salt stress substantially reduced stomatal conductance, transpiration rate, relative water content (RWC), total chlorophyll content, chlorophyll a, chlorophyll b, carotenoid content, plant height, leaf area, dry biomass, seed yield, and salt tolerance index. The PGPR strains and Si levels independently improved all the aforementioned parameters. Furthermore, the combined application of the B. drentensis strain with 2 kg Si ha−1 resulted in the greatest enhancement of mung bean physiology, growth, and yield. Overall, the results of this study provide important information for the benefit of the agricultural industry.

  1. Plant Growth Promoting Rhizobacteria and Silicon Synergistically Enhance Salinity Tolerance of Mung Bean

    KAUST Repository

    Mahmood, Sajid; Daur, Ihsanullah; Al-Solaimani, Samir G.; Ahmad, Shakeel; Madkour, Mohamed H.; Yasir, Muhammad; Hirt, Heribert; Ali, Shawkat; Ali, Zahir

    2016-01-01

    The present study explored the eco-friendly approach of utilizing plant-growth-promoting rhizobacteria (PGPR) inoculation and foliar application of silicon (Si) to improve the physiology, growth, and yield of mung bean under saline conditions. We isolated 18 promising PGPR from natural saline soil in Saudi Arabia, and screened them for plant-growth-promoting activities. Two effective strains were selected from the screening trial, and were identified as Enterobacter cloacae and Bacillus drentensis using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry and 16S rRNA gene sequencing techniques, respectively. Subsequently, in a 2-year mung bean field trial, using a randomized complete block design with a split-split plot arrangement, we evaluated the two PGPR strains and two Si levels (1 and 2 kg ha−1), in comparison with control treatments, under three different saline irrigation conditions (3.12, 5.46, and 7.81 dS m−1). The results indicated that salt stress substantially reduced stomatal conductance, transpiration rate, relative water content (RWC), total chlorophyll content, chlorophyll a, chlorophyll b, carotenoid content, plant height, leaf area, dry biomass, seed yield, and salt tolerance index. The PGPR strains and Si levels independently improved all the aforementioned parameters. Furthermore, the combined application of the B. drentensis strain with 2 kg Si ha−1 resulted in the greatest enhancement of mung bean physiology, growth, and yield. Overall, the results of this study provide important information for the benefit of the agricultural industry.

  2. Adult-type myogenesis of the frog Xenopus laevis specifically suppressed by notochord cells but promoted by spinal cord cells in vitro.

    Science.gov (United States)

    Yamane, Hitomi; Ihara, Setsunosuke; Kuroda, Masaaki; Nishikawa, Akio

    2011-08-01

    Larval-to-adult myogenic conversion occurs in the dorsal muscle but not in the tail muscle during Xenopus laevis metamorphosis. To know the mechanism for tail-specific suppression of adult myogenesis, response character was compared between adult myogenic cells (Ad-cells) and larval tail myogenic cells (La-cells) to a Sonic hedgehog (Shh) inhibitor, notochord (Nc) cells, and spinal cord (SC) cells in vitro. Cyclopamine, an Shh inhibitor, suppressed the differentiation of cultured Ad (but not La) cells, suggesting the significance of Shh signaling in promoting adult myogenesis. To test the possibility that Shh-producing axial elements (notochord and spinal cord) regulate adult myogenesis, Ad-cells or La-cells were co-cultured with Nc or SC cells. The results showed that differentiation of Ad-cells were strongly inhibited by Nc cells but promoted by SC cells. If Ad-cells were "separately" co-cultured with Nc cells without direct cell-cell interactions, adult differentiation was not inhibited but rather promoted, suggesting that Nc cells have two roles, one is a short-range suppression and another is a long-range promotion for adult myogenesis. Immunohistochemical analysis showed both notochord and spinal cord express the N-terminal Shh fragment throughout metamorphosis. The "spinal cord-promotion" and long-range effect by Nc cells on adult myogenesis is thus involved in Shh signaling, while the signaling concerning the short-range "Nc suppression" will be determined by future studies. Interestingly, these effects, "Nc suppression" and "SC promotion" were not observed for La-cells. Situation where the spinal cord/notochord cross-sectional ratio is quite larger in tadpole trunk than in the tail seems to contribute to trunk-specific promotion and tail-specific suppression of adult myogenesis during Xenopus metamorphosis.

  3. Ginseng Berry Extract Promotes Maturation of Mouse Dendritic Cells.

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    Full Text Available Ginseng extract has been shown to possess certain anti-virus, anti-tumor and immune-activating effects. However, the immunostimulatory effect of ginseng berry extract (GB has been less well characterized. In this study, we investigated the effect of GB on the activation of mouse dendritic cells (DCs in vitro and in vivo. GB treatment induced up-regulation of co-stimulatory molecules in bone marrow-derived DCs (BMDCs. Interestingly, GB induced a higher degree of co-stimulatory molecule up-regulation than ginseng root extract (GR at the same concentrations. Moreover, in vivo administration of GB promoted up-regulation of CD86, MHC class I and MHC class II and production of IL-6, IL-12 and TNF-α in spleen DCs. GB also promoted the generation of Th1 and Tc1 cells. Furthermore, Toll like receptor 4 (TLR4 and myeloid differentiation primary response 88 (MyD88 signaling pathway were essential for DC activation induced by GB. In addition, GB strongly prompted the proliferation of ovalbumin (OVA-specific CD4 and CD8 T cells. Finally, GB induced DC activation in tumor-bearing mice and the combination of OVA and GB treatment inhibited B16-OVA tumor cell growth in C57BL/6 mice. These results demonstrate that GB is a novel tumor therapeutic vaccine adjuvant by promoting DC and T cell activation.

  4. The role of Foxp3+ regulatory T cells in liver transplant tolerance.

    Science.gov (United States)

    Li, W; Carper, K; Zheng, X X; Kuhr, C S; Reyes, J D; Liang, Y; Perkins, D L; Thomson, A W; Perkins, J D

    2006-12-01

    The liver has long been considered a tolerogenic organ that favors the induction of peripheral tolerance. The mechanisms underlying liver tolerogenicity remain largely undefined. In this study, we characterized Foxp3-expressing CD4+ CD25+ regulatory T cells (Treg) in liver allograft recipients and examined the role of Treg in inherent liver tolerogenicity by employing the mouse spontaneous liver transplant tolerance model. Orthotopic liver transplantation was performed from C57BL/10 (H2b) to C3H/HeJ (H2k) mice. The percentage of CD4+ CD25+ Treg was expanded in the liver grafts and recipient spleens from day 5 up to day 100 posttransplantation, associated with high intracellular Foxp3 and CTLA4 expression. Immunohistochemistry further demonstrated significant numbers of Foxp3+ cells in the liver grafts and recipient spleens and increased transforming growth factor beta expression in the recipient spleens throughout the time courses. Adoptive transfer of spleen cells from the long-term liver allograft survivors significantly prolonged donor heart graft survival. Depletion of recipient CD4+ CD25+ Treg using anti-CD25 monoclonal antibody (250 microg/d) induced acute liver allograft rejection, associated with elevated anti-donor T-cell proliferative responses, CTL and natural killer activities, enhanced interleukin (IL)-2, interferon-gamma, IL-10, and decreased IL-4 production, and decreased T-cell apoptotic activity in anti-CD25-treated recipients. Moreover, CTLA4 blockade by anti-CTLA4 monoclonal antibody administration exacerbated liver graft rejection when combined with anti-CD25 monoclonal antibody. Thus, Foxp3+ CD4+ CD25+ Treg appear to underpin spontaneous acceptance of major histocompatability complex- mismatched liver allografts in mice. CTLA4, IL-4, and apoptosis of alloreactive T cells appear to contribute to the function of Treg and regulation of graft outcome.

  5. Interleukin 17-producing γδT cells promote hepatic regeneration in mice.

    Science.gov (United States)

    Rao, Raghavendra; Graffeo, Christopher S; Gulati, Rishabh; Jamal, Mohsin; Narayan, Suchithra; Zambirinis, Constantinos P; Barilla, Rocky; Deutsch, Michael; Greco, Stephanie H; Ochi, Atsuo; Tomkötter, Lena; Blobstein, Reuven; Avanzi, Antonina; Tippens, Daniel M; Gelbstein, Yisroel; Van Heerden, Eliza; Miller, George

    2014-08-01

    Subsets of leukocytes synergize with regenerative growth factors to promote hepatic regeneration. γδT cells are early responders to inflammation-induced injury in a number of contexts. We investigated the role of γδT cells in hepatic regeneration using mice with disruptions in Tcrd (encodes the T-cell receptor δ chain) and Clec7a (encodes C-type lectin domain family 7 member a, also known as DECTIN1). We performed partial hepatectomies on wild-type C57BL/6, CD45.1, Tcrd(-/-), or Clec7a(-/-) mice. Cells were isolated from livers of patients and mice via mechanical and enzymatic digestion. γδT cells were purified by fluorescence-activated cell sorting. In mice, partial hepatectomy up-regulated expression of CCL20 and ligands of Dectin-1, which was associated with recruitment and activation of γδT cells and their increased production of interleukin (IL)-17 family cytokines. Recruited γδT cells induced production of IL-6 by antigen-presenting cells and suppressed expression of interferon gamma by natural killer T cells, promoting hepatocyte proliferation. Absence of IL-17-producing γδT cells or deletion of Dectin-1 prevented development of regenerative phenotypes in subsets of innate immune cells. This slowed liver regeneration and was associated with reduced expression of regenerative growth factors and cell cycle regulators. Conversely, exogenous administration of IL-17 family cytokines or Dectin-1 ligands promoted regeneration. More broadly, we found that γδT cells are required for inflammatory responses mediated by IL-17 and Dectin-1. γδT cells regulate hepatic regeneration by producing IL-22 and IL-17, which have direct mitogenic effects on hepatocytes and promote a regenerative phenotype in hepatic leukocytes, respectively. Dectin-1 ligation is required for γδT cells to promote hepatic regeneration. Copyright © 2014 AGA Institute. Published by Elsevier Inc. All rights reserved.

  6. Comparative polygenic analysis of maximal ethanol accumulation capacity and tolerance to high ethanol levels of cell proliferation in yeast.

    Directory of Open Access Journals (Sweden)

    Thiago M Pais

    2013-06-01

    Full Text Available The yeast Saccharomyces cerevisiae is able to accumulate ≥17% ethanol (v/v by fermentation in the absence of cell proliferation. The genetic basis of this unique capacity is unknown. Up to now, all research has focused on tolerance of yeast cell proliferation to high ethanol levels. Comparison of maximal ethanol accumulation capacity and ethanol tolerance of cell proliferation in 68 yeast strains showed a poor correlation, but higher ethanol tolerance of cell proliferation clearly increased the likelihood of superior maximal ethanol accumulation capacity. We have applied pooled-segregant whole-genome sequence analysis to identify the polygenic basis of these two complex traits using segregants from a cross of a haploid derivative of the sake strain CBS1585 and the lab strain BY. From a total of 301 segregants, 22 superior segregants accumulating ≥17% ethanol in small-scale fermentations and 32 superior segregants growing in the presence of 18% ethanol, were separately pooled and sequenced. Plotting SNP variant frequency against chromosomal position revealed eleven and eight Quantitative Trait Loci (QTLs for the two traits, respectively, and showed that the genetic basis of the two traits is partially different. Fine-mapping and Reciprocal Hemizygosity Analysis identified ADE1, URA3, and KIN3, encoding a protein kinase involved in DNA damage repair, as specific causative genes for maximal ethanol accumulation capacity. These genes, as well as the previously identified MKT1 gene, were not linked in this genetic background to tolerance of cell proliferation to high ethanol levels. The superior KIN3 allele contained two SNPs, which are absent in all yeast strains sequenced up to now. This work provides the first insight in the genetic basis of maximal ethanol accumulation capacity in yeast and reveals for the first time the importance of DNA damage repair in yeast ethanol tolerance.

  7. Creando entornos de convivencia social (Creating Environments for Social Tolerance).

    Science.gov (United States)

    Moreno Garcia, Teresa, Ed.

    2002-01-01

    This Spanish- and Portuguese-language bulletin presents articles on matters of tolerance, and the lack of it. Among the topics covered are the similarities and differences between projects and organizations that promote tolerance, methods of teaching tolerance, four different projects that combat violence, and some ways in which such projects…

  8. Aquaporin 2 promotes cell migration and epithelial morphogenesis.

    Science.gov (United States)

    Chen, Ying; Rice, William; Gu, Zhizhan; Li, Jian; Huang, Jianmin; Brenner, Michael B; Van Hoek, Alfred; Xiong, Jianping; Gundersen, Gregg G; Norman, Jim C; Hsu, Victor W; Fenton, Robert A; Brown, Dennis; Lu, Hua A Jenny

    2012-09-01

    The aquaporin 2 (AQP2) water channel, expressed in kidney collecting ducts, contributes critically to water homeostasis in mammals. Animals lacking or having significantly reduced levels of AQP2, however, have not only urinary concentrating abnormalities but also renal tubular defects that lead to neonatal mortality from renal failure. Here, we show that AQP2 is not only a water channel but also an integrin-binding membrane protein that promotes cell migration and epithelial morphogenesis. AQP2 expression modulates the trafficking and internalization of integrin β1, facilitating its turnover at focal adhesions. In vitro, disturbing the interaction between AQP2 and integrin β1 by mutating the RGD motif led to reduced endocytosis, retention of integrin β1 at the cell surface, and defective cell migration and tubulogenesis. Similarly, in vivo, AQP2-null mice exhibited significant retention of integrin β1 at the basolateral membrane and had tubular abnormalities. In summary, these data suggest that the water channel AQP2 interacts with integrins to promote renal epithelial cell migration, contributing to the structural and functional integrity of the mammalian kidney.

  9. Regulation of mRNA translation influences hypoxia tolerance

    International Nuclear Information System (INIS)

    Koritzinsky, M.; Wouters, B.G.; Koumenis, C.

    2003-01-01

    Hypoxia is a heterogenous but common characteristic of human tumours and poor oxygenation is associated with poor prognosis. We believe that the presence of viable hypoxic tumor cells reflects in part an adaptation and tolerance of these cells to oxygen deficiency. Since oxidative phosphorylation is compromized during hypoxia, adaptation may involve both the upregulation of glycolysis as well as downregulation of energy consumption. mRNA translation is one of the most energy costly cellular processes, and we and others have shown that global mRNA translation is rapidly inhibited during hypoxia. However, some mRNAs, including those coding for HIF-1 α and VEGF, remain efficiently translated during hypoxia. Clearly, the mechanisms responsible for the overall inhibition of translation during hypoxia does not compromize the translation of certain hypoxia-induced mRNA species. We therefore hypothesize that the inhibition of mRNA translation serves to promote hypoxia tolerance in two ways: i) through conservation of energy and ii) through differential gene expression involved in hypoxia adaptation. We have recently identified two pathways that are responsible for the global inhibition of translation during hypoxia. The phosphorylation of the eukaryotic initiation factor eIF2 α by the ER resident kinase PERK results in down-regulation of protein synthesis shortly after the onset of hypoxia. In addition, the initiation complex eIF4F is disrupted during long lasting hypoxic conditions. The identification of the molecular pathways responsible for the inhibition of overall translation during hypoxia has rendered it possible to investigate their importance for hypoxia tolerance. We have found that mouse embryo fibroblasts that are knockout for PERK and therefore not able to inhibit protein synthesis efficiently during oxygen deficiency are significantly less tolerant to hypoxia than their wildtype counterparts. We are currently also investigating the functional significance

  10. Hypoxia-induced secretion of TGF-β1 in mesenchymal stem cell promotes breast cancer cell progression.

    Science.gov (United States)

    Hung, Shun-Pei; Yang, Muh-Hwa; Tseng, Kuo-Fung; Lee, Oscar K

    2013-01-01

    In solid tumors, a decreased oxygen and nutrient supply creates a hypoxic microenvironment in the central region. This hypoxic condition induces molecular responses of normal and cancer cells in the local area, including angiogenesis, metabolic changes, and metastasis. In addition, other cells including mesenchymal stem cells (MSCs) have been reported to be recruited into the hypoxic area of solid tumors. In our previous study, we found that hypoxic condition induces the secretion of growth factors and cytokines in MSCs, and here we demonstrate that elevated secretion of transforming growth factor-β1 (TGF-β1) by MSCs under hypoxia promotes the growth, motility, and invasive ability of breast cancer cells. It was found that TGF-β1 promoter activity was regulated by hypoxia, and the major hypoxia-regulated element was located between bp -1030 to -666 in front of the TGF-β1 promoter region. In ChIP assay, the results revealed that HIF-1 was bound to the hypoxia response element (HRE) of TGF-β1 promoter. Collectively, the results indicate that hypoxia microenvironment can enhance cancer cell growth through the paracrine effects of the MSCs by driving their TGF-β1 gene expression and secretion. Therefore, extra caution has to be exercised when considering hypoxia pretreatment of MSCs before cell transplantation into patients for therapeutic purposes, particularly in patients susceptible to tumor growth.

  11. Bone Marrow Derived Mesenchymal Stromal Cells Harness Purinergenic Signaling to Tolerize Human Th1 Cells In Vivo

    Science.gov (United States)

    Amarnath, Shoba; Foley, Jason E.; Farthing, Don E.; Gress, Ronald E.; Laurence, Arian; Eckhaus, Michael A.; Métais, Jean-Yves; Rose, Jeremy J.; Hakim, Frances T.; Felizardo, Tania C.; Cheng, Austin V.; Robey, Pamela G.; Stroncek, David E.; Sabatino, Marianna; Battiwalla, Minoo; Ito, Sawa; Fowler, Daniel H.; Barrett, Austin J.

    2014-01-01

    The use of bone marrow derived mesenchymal stromal cells (BMSC) in the treatment of alloimmune and autoimmune conditions has generated much interest, yet an understanding of the therapeutic mechanism remains elusive. We therefore explored immune modulation by a clinical-grade BMSC product in a model of human-into-mouse xenogeneic GVHD (x-GVHD) mediated by human CD4+ Th1 cells. BMSC reversed established, lethal x-GVHD through marked inhibition of Th1 cell effector function. Gene marking studies indicated BMSC engraftment was limited to the lung; further, there was no increase in regulatory T cells, thereby suggesting a paracrine mechanism of BMSC action. BMSC recipients had increased serum CD73 expressing exosomes that promoted adenosine accumulation ex vivo. Importantly, immune modulation mediated by BMSC was fully abrogated by pharmacologic therapy with an adenosine A2A receptor antagonist. To investigate the potential clinical relevance of these mechanistic findings, patient serum samples collected pre- and post-BMSC treatment were studied for exosome content: CD73 expressing exosomes promoting adenosine accumulation were detected in post-BMSC samples. In conclusion, BMSC effectively modulate experimental GVHD through a paracrine mechanism that promotes adenosine-based immune suppression. PMID:25532725

  12. Cecum lymph node dendritic cells harbor slow-growing bacteria phenotypically tolerant to antibiotic treatment.

    Directory of Open Access Journals (Sweden)

    Patrick Kaiser

    2014-02-01

    Full Text Available In vivo, antibiotics are often much less efficient than ex vivo and relapses can occur. The reasons for poor in vivo activity are still not completely understood. We have studied the fluoroquinolone antibiotic ciprofloxacin in an animal model for complicated Salmonellosis. High-dose ciprofloxacin treatment efficiently reduced pathogen loads in feces and most organs. However, the cecum draining lymph node (cLN, the gut tissue, and the spleen retained surviving bacteria. In cLN, approximately 10%-20% of the bacteria remained viable. These phenotypically tolerant bacteria lodged mostly within CD103⁺CX₃CR1⁻CD11c⁺ dendritic cells, remained genetically susceptible to ciprofloxacin, were sufficient to reinitiate infection after the end of the therapy, and displayed an extremely slow growth rate, as shown by mathematical analysis of infections with mixed inocula and segregative plasmid experiments. The slow growth was sufficient to explain recalcitrance to antibiotics treatment. Therefore, slow-growing antibiotic-tolerant bacteria lodged within dendritic cells can explain poor in vivo antibiotic activity and relapse. Administration of LPS or CpG, known elicitors of innate immune defense, reduced the loads of tolerant bacteria. Thus, manipulating innate immunity may augment the in vivo activity of antibiotics.

  13. Osteoprotegerin expression in triple-negative breast cancer cells promotes metastasis

    International Nuclear Information System (INIS)

    Weichhaus, Michael; Segaran, Prabu; Renaud, Ashleigh; Geerts, Dirk; Connelly, Linda

    2014-01-01

    Osteoprotegerin (OPG) is a secreted member of the tumor necrosis factor (TNF) receptor superfamily that has been well characterized as a negative regulator of bone remodeling. OPG is also expressed in human breast cancer tissues and cell lines. In vitro studies suggest that OPG exerts tumor-promoting effects by binding to TNF-related apoptosis inducing ligand (TRAIL), thereby preventing induction of apoptosis. However, the in vivo effect of OPG expression by primary breast tumors has not been characterized. We knocked down OPG expression in MDA-MB-231 and MDA-MB-436 human breast cancer cells using shRNA and siRNA to investigate impact on metastasis in the chick embryo model. We observed a reduction in metastasis with OPG knockdown cells. We found that lowering OPG expression did not alter sensitivity to TRAIL-induced apoptosis; however, the OPG knockdown cells had a reduced level of invasion. In association with this we observed reduced expression of the proteases Cathepsin D and Matrix Metalloproteinase-2 upon OPG knockdown, indicating that OPG may promote metastasis via modulation of protease expression and invasion. We conclude that OPG has a metastasis-promoting effect in breast cancer cells

  14. Phosphorylated Akt Protein at Ser473 Enables HeLa Cells to Tolerate Nutrient-Deprived Conditions

    Science.gov (United States)

    Fathy, Moustafa; Awale, Suresh; Nikaido, Toshio

    2017-12-29

    Background: Despite angiogenesis, many tumours remain hypovascular and starved of nutrients while continuing to grow rapidly. The specific biochemical mechanisms associated with starvation resistance, austerity, may be new biological characters of cancer that are critical for cancer progression. Objective: This study aim was to investigate the effect of nutrient starvation on HeLa cells and the possible mechanism by which the cells are able to tolerate nutrient-deprived conditions. Methods: Nutrient starvation was achieved by culturing HeLa cells in nutrient-deprived medium (NDM) and cell survival was estimated by using cell counting kit-8. The effect of starvation on cell cycle distribution and the quantitative analysis of apoptotic cells were investigated by flow cytometry using propidium iodide staining. Western blotting was used to detect the expression levels of Akt and phosphorylated Akt at Ser473 (Ser473p-Akt) proteins. Results: HeLa cells displayed extremely long survival when cultured in NDM. The percentage of apoptotic HeLa cells was significantly increased by starvation in a time-dependent manner. A significant increase in the expression of Ser473p-Akt protein after starvation was also observed. Furthermore, it was found that Akt inhibitor III molecule inhibited the cells proliferation in a concentration- and time-dependent manner. Conclusion: Results of the present study provide evidence that Akt activation may be implicated in the tolerance of HeLa cells for nutrient starvation and may help to suggest new therapeutic strategies designed to prevent austerity of cervical cancer cells through inhibition of Akt activation. Creative Commons Attribution License

  15. Regulatory T-cells and immune tolerance in pregnancy : a new target for infertility treatment?

    NARCIS (Netherlands)

    Guerin, Leigh R.; Prins, Jelmer R.; Robertson, Sarah A.

    2009-01-01

    Adaptation of the maternal immune response to accommodate the semi-allogeneic fetus is necessary for pregnancy success, and disturbances in maternal tolerance are implicated in infertility and reproductive pathologies. T regulatory (Treg) cells are a recently discovered subset of T-lymphocytes with

  16. MRG15 activates the cdc2 promoter via histone acetylation in human cells

    International Nuclear Information System (INIS)

    Pena, AndreAna N.; Tominaga, Kaoru; Pereira-Smith, Olivia M.

    2011-01-01

    Chromatin remodeling is required for transcriptional activation and repression. MRG15 (MORF4L1), a chromatin modulator, is a highly conserved protein and is present in complexes containing histone acetyltransferases (HATs) as well as histone deacetylases (HDACs). Loss of expression of MRG15 in mice and Drosophila results in embryonic lethality and fibroblast and neural stem/progenitor cells cultured from Mrg15 null mouse embryos exhibit marked proliferative defects when compared with wild type cells. To determine the role of MRG15 in cell cycle progression we performed chromatin immunoprecipitation with an antibody to MRG15 on normal human fibroblasts as they entered the cell cycle from a quiescent state, and analyzed various cell cycle gene promoters. The results demonstrated a 3-fold increase in MRG15 occupancy at the cdc2 promoter during S phase of the cell cycle and a concomitant increase in acetylated histone H4. H4 lysine 12 was acetylated at 24 h post-serum stimulation while there was no change in acetylation of lysine 16. HDAC1 and 2 were decreased at this promoter during cell cycle progression. Over-expression of MRG15 in HeLa cells activated a cdc2 promoter-reporter construct in a dose-dependent manner, whereas knockdown of MRG15 resulted in decreased promoter activity. In order to implicate HAT activity, we treated cells with the HAT inhibitor anacardic acid and determined that HAT inhibition results in loss of expression of cdc2 mRNA. Further, chromatin immunoprecipitation with Tip60 localizes the protein to the same 110 bp stretch of the cdc2 promoter pulled down by MRG15. Additionally, we determined that cotransfection of MRG15 with the known associated HAT Tip60 had a cooperative effect in activating the cdc2 promoter. These results suggest that MRG15 is acting in a HAT complex involving Tip60 to modify chromatin via acetylation of histone H4 at the cdc2 promoter to activate transcription.

  17. MRG15 activates the cdc2 promoter via histone acetylation in human cells

    Energy Technology Data Exchange (ETDEWEB)

    Pena, AndreAna N., E-mail: andreana.pena@gmail.com [Sam and Ann Barshop Institute for Longevity and Aging Studies, The University of Texas Health Science Center at San Antonio, San Antonio, TX (United States); Department of Cellular and Structural Biology, The University of Texas Health Science Center at San Antonio, San Antonio, TX (United States); Tominaga, Kaoru; Pereira-Smith, Olivia M. [Sam and Ann Barshop Institute for Longevity and Aging Studies, The University of Texas Health Science Center at San Antonio, San Antonio, TX (United States); Department of Cellular and Structural Biology, The University of Texas Health Science Center at San Antonio, San Antonio, TX (United States)

    2011-07-01

    Chromatin remodeling is required for transcriptional activation and repression. MRG15 (MORF4L1), a chromatin modulator, is a highly conserved protein and is present in complexes containing histone acetyltransferases (HATs) as well as histone deacetylases (HDACs). Loss of expression of MRG15 in mice and Drosophila results in embryonic lethality and fibroblast and neural stem/progenitor cells cultured from Mrg15 null mouse embryos exhibit marked proliferative defects when compared with wild type cells. To determine the role of MRG15 in cell cycle progression we performed chromatin immunoprecipitation with an antibody to MRG15 on normal human fibroblasts as they entered the cell cycle from a quiescent state, and analyzed various cell cycle gene promoters. The results demonstrated a 3-fold increase in MRG15 occupancy at the cdc2 promoter during S phase of the cell cycle and a concomitant increase in acetylated histone H4. H4 lysine 12 was acetylated at 24 h post-serum stimulation while there was no change in acetylation of lysine 16. HDAC1 and 2 were decreased at this promoter during cell cycle progression. Over-expression of MRG15 in HeLa cells activated a cdc2 promoter-reporter construct in a dose-dependent manner, whereas knockdown of MRG15 resulted in decreased promoter activity. In order to implicate HAT activity, we treated cells with the HAT inhibitor anacardic acid and determined that HAT inhibition results in loss of expression of cdc2 mRNA. Further, chromatin immunoprecipitation with Tip60 localizes the protein to the same 110 bp stretch of the cdc2 promoter pulled down by MRG15. Additionally, we determined that cotransfection of MRG15 with the known associated HAT Tip60 had a cooperative effect in activating the cdc2 promoter. These results suggest that MRG15 is acting in a HAT complex involving Tip60 to modify chromatin via acetylation of histone H4 at the cdc2 promoter to activate transcription.

  18. Orchestration of transplantation tolerance by regulatory dendritic cell therapy or in situ targeting of dendritic cells

    Science.gov (United States)

    Morelli, Adrian E.; Thomson, Angus W.

    2014-01-01

    Purpose of review Extensive research in murine transplant models over the past two decades has convincingly demonstrated the ability of regulatory dendritic cells (DCreg) to promote long-term allograft survival. We review important considerations regarding the source of therapeutic DCreg (donor or recipient) and their mode of action, in situ targeting of DCreg, and optimal therapeutic regimens to promote DCreg function. Recent findings Recent studies have defined protocols and mechanisms whereby ex vivo-generated DCreg of donor or recipient origin subvert allogeneic T cell responses and promote long-term organ transplant survival. Particular interest has focused on how donor antigen (Ag) is acquired, processed and presented by autologous DCs, on the stability of DCreg, and on in situ targeting of DC to promote their tolerogenic function. New evidence of the therapeutic efficacy of DCreg in a clinically-relevant non-human primate organ transplant model and production of clinical grade DCreg support early evaluation of DCreg therapy in human graft recipients. Summary We discuss strategies currently used to promote DC tolerogenicity, including DCreg therapy and in situ targeting of DC, with a view to improved understanding of underlying mechanisms and identification of the most promising strategies for therapeutic application. PMID:24926700

  19. Differential Top10 promoter regulation by six tetracycline analogues in plant cells

    Science.gov (United States)

    Love, John; Allen, George C.; Gatz, Christiane; Thompson, William F.; Brown, C. S. (Principal Investigator)

    2002-01-01

    The effects of five tetracycline analogues, anhydrotetracycline, doxycycline, minocycline, oxytetracycline, and tetracycline, on Top10 promoter activity in NT1 tobacco tissue culture cells have been analysed. The concentration that repressed Top10 promoter activity, the level of transgene repression and the kinetics of transgene de-repression were determined for each analogue, and could not be predicted from in vitro binding affinity to the tetracycline repressor or from comparison with animal cells. Doxycycline had the most potent effect on the Top10 promoter and completely inhibited transgene expression at 4 nmol l(-1). Tetracycline was the most versatile of the analogues tested; tetracycline inhibited the Top10 promoter at 10 nmol l(-1) and was easily washed out to restore Top10-driven expression in 12-24 h. A study was also made of the suitability for plant research of a novel tetracycline analogue, GR33076X. In animal cells, GR33076X de-repressed Top10 promoter activity in the presence of inhibitory concentrations of anhydrotetracycline. In NT1, it is shown that GR 33076X can antagonize repression of the Top10 promoter in the presence of tetracycline, but not of anhydrotetracycline or of doxycycline. Different tetracycline analogues can therefore be used to regulate the Top10 promoter in plant cells and this property may be exploited in planning an optimum course of transgene regulation.

  20. Scaffold architecture and fibrin gels promote meniscal cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Pawelec, K. M., E-mail: pawelec.km@gmail.com, E-mail: jw626@cam.ac.uk; Best, S. M.; Cameron, R. E. [Cambridge Centre for Medical Materials, Materials Science and Metallurgy Department, University of Cambridge, Cambridge CB3 0FS (United Kingdom); Wardale, R. J., E-mail: pawelec.km@gmail.com, E-mail: jw626@cam.ac.uk [Division of Trauma and Orthopaedic Surgery, Department of Surgery, University of Cambridge, Cambridge CB2 2QQ (United Kingdom)

    2015-01-01

    Stability of the knee relies on the meniscus, a complex connective tissue with poor healing ability. Current meniscal tissue engineering is inadequate, as the signals for increasing meniscal cell proliferation have not been established. In this study, collagen scaffold structure, isotropic or aligned, and fibrin gel addition were tested. Metabolic activity was promoted by fibrin addition. Cellular proliferation, however, was significantly increased by both aligned architectures and fibrin addition. None of the constructs impaired collagen type I production or triggered adverse inflammatory responses. It was demonstrated that both fibrin gel addition and optimized scaffold architecture effectively promote meniscal cell proliferation.

  1. Ruthenium cluster-like chalcogenide as a methanol tolerant cathode catalyst in air-breathing laminar flow fuel cells

    International Nuclear Information System (INIS)

    Whipple, Devin T.; Jayashree, Ranga S.; Egas, Daniela; Alonso-Vante, Nicolas; Kenis, Paul J.A.

    2009-01-01

    This paper reports the incorporation of a cluster-like Ru x Se y as a methanol tolerant cathode catalyst in a laminar flow fuel cell. The effect on cell performance of several concentrations of methanol in the cathode stream was investigated for the Ru x Se y catalyst and compared to a conventional platinum catalyst. While the Pt catalyst exhibited up to ∼80% drop in power density, the Ru x Se y catalyst showed no decrease in performance when the cathode was exposed to methanol. At several methanol concentrations the Ru x Se y catalyst performed better than the Pt catalyst. This demonstration of a methanol tolerant catalyst in a laminar flow fuel cell opens up the way for further miniaturization of the cell design and simplification of its operation as the need for an electrolyte stream to prevent fuel crossover has been eliminated.

  2. Cell recognition molecule L1 promotes embryonic stem cell differentiation through the regulation of cell surface glycosylation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ying [Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044 (China); Department of Clinical Laboratory, Second Affiliated Hospital of Dalian Medical University, Dalian 116023 (China); Huang, Xiaohua [Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044 (China); Department of Clinical Biochemistry, College of Laboratory Medicine, Dalian Medical University, Dalian 116044 (China); An, Yue [Department of Clinical Laboratory, Second Affiliated Hospital of Dalian Medical University, Dalian 116023 (China); Ren, Feng [Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044 (China); Yang, Zara Zhuyun; Zhu, Hongmei; Zhou, Lei [The Key Laboratory of Stem Cell and Regenerative Medicine, Institute of Molecular and Clinical Medicine, Kunming Medical University, Kunming 650228 (China); Department of Anatomy and Developmental Biology, Monash University, Clayton 3800 (Australia); He, Xiaowen; Schachner, Melitta [Keck Center for Collaborative Neuroscience and Department of Cell Biology and Neuroscience, Rutgers University, New Brunswick, NJ (United States); Xiao, Zhicheng, E-mail: zhicheng.xiao@monash.edu [The Key Laboratory of Stem Cell and Regenerative Medicine, Institute of Molecular and Clinical Medicine, Kunming Medical University, Kunming 650228 (China); Department of Anatomy and Developmental Biology, Monash University, Clayton 3800 (Australia); Ma, Keli, E-mail: makeli666@aliyun.com [Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044 (China); Li, Yali, E-mail: yalilipaper@gmail.com [Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044 (China); Department of Anatomy, National University of Singapore, Singapore 119078 (Singapore)

    2013-10-25

    Highlights: •Down-regulating FUT9 and ST3Gal4 expression blocks L1-induced neuronal differentiation of ESCs. •Up-regulating FUT9 and ST3Gal4 expression in L1-ESCs depends on the activation of PLCγ. •L1 promotes ESCs to differentiate into neuron through regulating cell surface glycosylation. -- Abstract: Cell recognition molecule L1 (CD171) plays an important role in neuronal survival, migration, differentiation, neurite outgrowth, myelination, synaptic plasticity and regeneration after injury. Our previous study has demonstrated that overexpressing L1 enhances cell survival and proliferation of mouse embryonic stem cells (ESCs) through promoting the expression of FUT9 and ST3Gal4, which upregulates cell surface sialylation and fucosylation. In the present study, we examined whether sialylation and fucosylation are involved in ESC differentiation through L1 signaling. RNA interference analysis showed that L1 enhanced differentiation of ESCs into neurons through the upregulation of FUT9 and ST3Gal4. Furthermore, blocking the phospholipase Cγ (PLCγ) signaling pathway with either a specific PLCγ inhibitor or knockdown PLCγ reduced the expression levels of both FUT9 and ST3Gal4 mRNAs and inhibited L1-mediated neuronal differentiation. These results demonstrate that L1 promotes neuronal differentiation from ESCs through the L1-mediated enhancement of FUT9 and ST3Gal4 expression.

  3. Cell recognition molecule L1 promotes embryonic stem cell differentiation through the regulation of cell surface glycosylation

    International Nuclear Information System (INIS)

    Li, Ying; Huang, Xiaohua; An, Yue; Ren, Feng; Yang, Zara Zhuyun; Zhu, Hongmei; Zhou, Lei; He, Xiaowen; Schachner, Melitta; Xiao, Zhicheng; Ma, Keli; Li, Yali

    2013-01-01

    Highlights: •Down-regulating FUT9 and ST3Gal4 expression blocks L1-induced neuronal differentiation of ESCs. •Up-regulating FUT9 and ST3Gal4 expression in L1-ESCs depends on the activation of PLCγ. •L1 promotes ESCs to differentiate into neuron through regulating cell surface glycosylation. -- Abstract: Cell recognition molecule L1 (CD171) plays an important role in neuronal survival, migration, differentiation, neurite outgrowth, myelination, synaptic plasticity and regeneration after injury. Our previous study has demonstrated that overexpressing L1 enhances cell survival and proliferation of mouse embryonic stem cells (ESCs) through promoting the expression of FUT9 and ST3Gal4, which upregulates cell surface sialylation and fucosylation. In the present study, we examined whether sialylation and fucosylation are involved in ESC differentiation through L1 signaling. RNA interference analysis showed that L1 enhanced differentiation of ESCs into neurons through the upregulation of FUT9 and ST3Gal4. Furthermore, blocking the phospholipase Cγ (PLCγ) signaling pathway with either a specific PLCγ inhibitor or knockdown PLCγ reduced the expression levels of both FUT9 and ST3Gal4 mRNAs and inhibited L1-mediated neuronal differentiation. These results demonstrate that L1 promotes neuronal differentiation from ESCs through the L1-mediated enhancement of FUT9 and ST3Gal4 expression

  4. hTERT promoter mediating gene therapy in laryngeal squamous carcinomas cells in vitro

    International Nuclear Information System (INIS)

    Liao Zhengkai; Zhou Yunfeng; Zhou Fuxiang; Luo Zhiguo; Xiong Jie; Bao Jie; Xie Conghua; Liu Shiquan

    2007-01-01

    Objective: To investigate the relationship among hTERT promoter activity, hTERT mRNA expression, and telomerase activity (TA) in laryngeal squamous carcinomas cell lines, and to evaluate the usefulness of hTERT promoter mediated gene therapy. Methods: After plasmids pGL3-hTERTp were transfected, hTEBT promoter activity, hTERT mRNA expression and TA were determined by luciferase assay, RT-PCR and TRAP-PCR-ELISA, respectively. Plasmid phTERTp-HRP was constructed and transfected, HRP expression was determined by RT-PCR and competent peroxidase activity was confirmed by enzyme activity assay. The cytotoxicity and radiosensitivity of phTERTp-HRP/IAA were determined by clonogenic assay. Results: The relative levels of hTERT promoter activity, hTERT mRNA expression and TA in Hep2R cells were 1.37-fold, 1.43-fold and 1.81-fold compared with Hep2R cells, hTERT promoter activity was closely associated with hTERT mRNA expression and TA levels (P SF 2 ) was 1.24 (Hep2R cells) and 1.20 (Hep 2cells), the parameter a of with or without IAA incubation were 0.090, 0.020 (Hep2R)and 0.099, 0.042 (Hep2). Conclusions: hTERT promoter is applicable in mediating gene therapy in different radiosensitive laryngeal squamous carcinomas cells. hTERTp-HRP/IAA gene therapy may be a promising supplementary method for radiotherapy of laryngeal squamous-cell carcinomas. (authors)

  5. Antibody response against Betaferon® in immune tolerant mice: involvement of marginal zone B-cells and CD4+ T-cells and apparent lack of immunological memory.

    Science.gov (United States)

    Sauerborn, Melody; van Beers, Miranda M C; Jiskoot, Wim; Kijanka, Grzegorz M; Boon, Louis; Schellekens, Huub; Brinks, Vera

    2013-01-01

    The immunological processes underlying immunogenicity of recombinant human therapeutics are poorly understood. Using an immune tolerant mouse model we previously demonstrated that aggregates are a major trigger of the antidrug antibody (ADA) response against recombinant human interferon beta (rhIFNβ) products including Betaferon®, and that immunological memory seems to be lacking after a rechallenge with non-aggregated rhIFNβ. The apparent absence of immunological memory indicates a CD4+ T-cell independent (Tind) immune response underlying ADA formation against Betaferon®. This hypothesis was tested. Using the immune tolerant mouse model we first validated that rechallenge with highly aggregated rhIFNβ (Betaferon®) does not lead to a subsequent fast increase in ADA titers, suggesting a lack of immunological memory. Next we assessed whether Betaferon® could act as Tind antigen by inactivation of marginal zone (MZ) B-cells during treatment. MZ B-cells are major effector cells involved in a Tind immune response. In a following experiment we depleted the mice from CD4+ T-cells to test their involvement in the ADA response against Betaferon®. Inactivation of MZ B-cells at the start of Betaferon® treatment drastically lowered ADA levels, suggesting a Tind immune response. However, persistent depletion of CD4+ T-cells before and during Betaferon® treatment abolished the ADA response in almost all mice. The immune response against rhIFNβ in immune tolerant mice is neither a T-cell independent nor a classical T-cell dependent immune response. Further studies are needed to confirm absence of immunological memory (cells).

  6. Bile salt tolerance of Lactococcus lactis is enhanced by expression of bile salt hydrolase thereby producing less bile acid in the cells.

    Science.gov (United States)

    Bi, Jie; Liu, Song; Du, Guocheng; Chen, Jian

    2016-04-01

    Changes of bile salt tolerance, morphology and amount of bile acid within cells were studied to evaluate the exact effects of bile salt hydrolase (BSH) on bile salt tolerance of microorganism. The effect of BSHs on the bile salt tolerance of Lactococcus lactis was examined by expressing two BSHs (BSH1 and BSH2). Growth of L. lactis expressing BSH1 or BSH2 was better under bile salt stress compared to wild-type L. lactis. As indicated by transmission electron microscopy, bile acids released by the action of BSH induced the formation of micelles around the membrane surface of cells subject to conjugated bile salt stress. A similar micelle containing bile acid was observed in the cytoplasm by liquid chromatography-mass spectrometry. BSH1 produced fewer bile acid micelles in the cytoplasm and achieved better cell growth of L. lactis compared to BSH2. Expression of BSH improved bile salt tolerance of L. lactis but excessive production by BSH of bile acid micelles in the cytoplasm inhibited cell growth.

  7. Promoter, transgene, and cell line effects in the transfection of mammalian cells using PDMAEMA-based nano-stars

    Directory of Open Access Journals (Sweden)

    Alexander Raup

    2016-09-01

    Full Text Available Non-viral transfection protocols are typically optimized using standard cells and reporter proteins, potentially underestimating cellular or transgene effects. Here such effects were studied for two human (Jurkat, HEK-293 and two rodent (CHO-K1, L929 cell lines and three fluorescent reporter proteins. Expression of the enhanced green fluorescent protein (EGFP was studied under the control of the human elongation factor 1 alpha promoter and three viral promoters (SV40, SV40/enhancer, CMV, that of ZsYellow1 (yellow fluorescence and mCherry (red fluorescence for the CMV promoter. Results varied with the cell line, in particular for the Jurkat cells. Pair-wise co-transfection of the CMV controlled transgenes resulted in a significant fraction of monochromatic cells (EGFP for EGFP/YFP and EGFP/RFP co-transfections, YFP in case of YFP/RFP co-transfections. Only Jurkat cells were almost incapable of expressing YFP. Dilution of the plasmid DNA with a non-expressed plasmid showed cell line dependent effects on transfection efficiency and/or expression levels.

  8. Wheat TaSP gene improves salt tolerance in transgenic Arabidopsis thaliana.

    Science.gov (United States)

    Ma, Xiaoli; Cui, Weina; Liang, Wenji; Huang, Zhanjing

    2015-12-01

    A novel salt-induced gene with unknown functions was cloned through analysis of gene expression profile of a salt-tolerant wheat mutant RH8706-49 under salt stress. The gene was named Triticum aestivum salt-related protein (TaSP) and deposited in GenBank (Accession No. KF307326). Quantitative polymerase chain reaction (qPCR) results showed that TaSP expression was induced under salt, abscisic acid (ABA), and polyethylene glycol (PEG) stresses. Subcellular localization revealed that TaSP was mainly localized in cell membrane. Overexpression of TaSP in Arabidopsis could improve salt tolerance of 35S::TaSP transgenic Arabidopsis. 35S::TaSP transgenic Arabidopsis lines after salt stress presented better physiological indexes than the control group. In the non-invasive micro-test (NMT), an evident Na(+) excretion was observed at the root tip of salt-stressed 35S::TaSP transgenic Arabidopsis. TaSP promoter was cloned, and its beta-glucuronidase (GUS) activities before and after ABA, salt, cold, heat, and salicylic acid (SA) stresses were determined. Full-length TaSP promoter contained ABA and salt response elements. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  9. Nocardia rubra cell-wall skeleton promotes CD4+ T cell activation and drives Th1 immune response.

    Science.gov (United States)

    Wang, Guangchuan; Wu, Jie; Miao, Miao; Dou, Heng; Nan, Ning; Shi, Mingsheng; Yu, Guang; Shan, Fengping

    2017-08-01

    Several lines of evidences have shown that Nocardia rubra cell wall skeleton (Nr-CWS) has immunoregulatory and anti-tumor activities. However, there is no information about the effect of Nr-CWS on CD4 + T cells. The aim of this study was to explore the effect of Nr-CWS on the phenotype and function of CD4 + T cells. Our results of in vitro experiments showed that Nr-CWS could significantly up-regulate the expression of CD69 and CD25 on CD4 + T cells, promote the proliferation of CD4 + T cells, increase the production of IFN-γ, TNF-α and IL-2 in the supernatants, but has no significant effect on the apoptosis and death of CD4 + T cells. Results of in vivo experiments showed that Nr-CWS could promote the proliferation of CD4 + T cells, and increase the production of IL-2, IFN-γ and TNF-α (Th1 type cytokines). These data suggest that Nr-CWS can enhance the activation of CD4 + T cells, promote the proliferation of CD4 + T cells and the differentiation of CD4 + T cells to Th1 cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. IGFBP1 increases β-cell regeneration by promoting α- to β-cell transdifferentiation.

    Science.gov (United States)

    Lu, Jing; Liu, Ka-Cheuk; Schulz, Nadja; Karampelias, Christos; Charbord, Jérémie; Hilding, Agneta; Rautio, Linn; Bertolino, Philippe; Östenson, Claes-Göran; Brismar, Kerstin; Andersson, Olov

    2016-09-15

    There is great interest in therapeutically harnessing endogenous regenerative mechanisms to increase the number of β cells in people with diabetes. By performing whole-genome expression profiling of zebrafish islets, we identified 11 secreted proteins that are upregulated during β-cell regeneration. We then tested the proteins' ability to potentiate β-cell regeneration in zebrafish at supraphysiological levels. One protein, insulin-like growth factor (Igf) binding-protein 1 (Igfbp1), potently promoted β-cell regeneration by potentiating α- to β-cell transdifferentiation. Using various inhibitors and activators of the Igf pathway, we show that Igfbp1 exerts its regenerative effect, at least partly, by inhibiting Igf signaling. Igfbp1's effect on transdifferentiation appears conserved across species: Treating mouse and human islets with recombinant IGFBP1 in vitro increased the number of cells co-expressing insulin and glucagon threefold. Moreover, a prospective human study showed that having high IGFBP1 levels reduces the risk of developing type-2 diabetes by more than 85%. Thus, we identify IGFBP1 as an endogenous promoter of β-cell regeneration and highlight its clinical importance in diabetes. © 2016 The Authors. Published under the terms of the CC BY NC ND 4.0 license.

  11. Stress-tolerant mutants induced by heavy-ion beams

    International Nuclear Information System (INIS)

    Abe, Tomoko; Yoshida, Shigeo; Bae, Chang-Hyu; Ozaki, Takuo

    2000-01-01

    Comparative study was made on mutagenesis in tobacco embryo induced by exposure to EMS (ethyl methane-sulfonate) ion beams during the fertilization cycle. Tobacco embryo cells immediately after pollination were exposed to heavy ion beam and the sensitivity to the irradiation was assessed in each developmental stage and compared with the effects of EMS, a chemical mutagen. Morphologically abnormality such as chlorophyll deficiency was used as a marker. A total of 17 salt-tolerant plants were selected from 3447 M 1 seeds. A cell line showed salt resistance. The cell growth and chlorophyll content were each two times higher than that of WT cells in the medium containing 154 mM NaCl. Seven strains of M 3 progeny of 17 salt-tolerant plants, showed strong resistance, but no salt tolerant progeny were obtained from Xanthi or Ne-ion irradiation. This shows that the sensitivity of plant embryo to this irradiation technique may vary among species. When exposed to 14 N ion beam for 24-108 hours after pollination, various morphological mutants appeared at 18% in M 1 progeny and herbicide tolerant and salt tolerant mutants were obtained. A strong Co-tolerant strain was obtained in two of 17 salt-tolerant strains and a total of 46 tolerant strains (0.2%) were obtained from 22,272 grains of M 1 seeds. In these tolerant strains, the absorption of Co was slightly decreased, but those of Mg and Mn were increased. Mutants induced with ion-beam irradiation have potential not only for practical use in the breeding of stress-tolerant plants but also for gene analysis that will surely facilitate the molecular understanding of the tolerance mechanisms. (M.N.)

  12. T Cell-Mediated Beta Cell Destruction: Autoimmunity and Alloimmunity in the Context of Type 1 Diabetes

    Directory of Open Access Journals (Sweden)

    Adam L. Burrack

    2017-12-01

    Full Text Available Type 1 diabetes (T1D results from destruction of pancreatic beta cells by T cells of the immune system. Despite improvements in insulin analogs and continuous blood glucose level monitoring, there is no cure for T1D, and some individuals develop life-threatening complications. Pancreas and islet transplantation have been attractive therapeutic approaches; however, transplants containing insulin-producing cells are vulnerable to both recurrent autoimmunity and conventional allograft rejection. Current immune suppression treatments subdue the immune system, but not without complications. Ideally a successful approach would target only the destructive immune cells and leave the remaining immune system intact to fight foreign pathogens. This review discusses the autoimmune diabetes disease process, diabetic complications that warrant a transplant, and alloimmunity. First, we describe the current understanding of autoimmune destruction of beta cells including the roles of CD4 and CD8 T cells and several possibilities for antigen-specific tolerance induction. Second, we outline diabetic complications necessitating beta cell replacement. Third, we discuss transplant recognition, potential sources for beta cell replacement, and tolerance-promoting therapies under development. We hypothesize that a better understanding of autoreactive T cell targets during disease pathogenesis and alloimmunity following transplant destruction could enhance attempts to re-establish tolerance to beta cells.

  13. Cell-Based Phenotyping Reveals QTL for Membrane Potential Maintenance Associated with Hypoxia and Salinity Stress Tolerance in Barley

    Directory of Open Access Journals (Sweden)

    Muhammad B. Gill

    2017-11-01

    Full Text Available Waterlogging and salinity are two major abiotic stresses that hamper crop production world-wide resulting in multibillion losses. Plant abiotic stress tolerance is conferred by many interrelated mechanisms. Amongst these, the cell’s ability to maintain membrane potential (MP is considered to be amongst the most crucial traits, a positive relationship between the ability of plants to maintain highly negative MP and its tolerance to both salinity and waterlogging stress. However, no attempts have been made to identify quantitative trait loci (QTL conferring this trait. In this study, the microelectrode MIFE technique was used to measure the plasma membrane potential of epidermal root cells of 150 double haploid (DH lines of barley (Hordeum vulgare L. from a cross between a Chinese landrace TX9425 and Japanese malting cultivar Naso Nijo under hypoxic conditions. A major QTL for the MP in the epidermal root cells in hypoxia-exposed plants was identified. This QTL was located on 2H, at a similar position to the QTL for waterlogging and salinity tolerance reported in previous studies. Further analysis confirmed that MP showed a significant contribution to both waterlogging and salinity tolerance. The fact that the QTL for MP was controlled by a single major QTL illustrates the power of the single-cell phenotyping approach and opens prospects for fine mapping this QTL and thus being more effective in marker assisted selection.

  14. Tumor-Infiltrating Immune Cells Promoting Tumor Invasion and Metastasis: Existing Theories

    Directory of Open Access Journals (Sweden)

    Yan-gao Man, Alexander Stojadinovic, Jeffrey Mason, Itzhak Avital, Anton Bilchik, Bjoern Bruecher, Mladjan Protic, Aviram Nissan, Mina Izadjoo, Xichen Zhang, Anahid Jewett

    2013-01-01

    Full Text Available It is a commonly held belief that infiltration of immune cells into tumor tissues and direct physical contact between tumor cells and infiltrated immune cells is associated with physical destructions of the tumor cells, reduction of the tumor burden, and improved clinical prognosis. An increasing number of studies, however, have suggested that aberrant infiltration of immune cells into tumor or normal tissues may promote tumor progression, invasion, and metastasis. Neither the primary reason for these contradictory observations, nor the mechanism for the reported diverse impact of tumor-infiltrating immune cells has been elucidated, making it difficult to judge the clinical implications of infiltration of immune cells within tumor tissues. This mini-review presents several existing hypotheses and models that favor the promoting impact of tumor-infiltrating immune cells on tumor invasion and metastasis, and also analyzes their strength and weakness.

  15. Breeding of Freeze-tolerant Yeast and the Mechanisms of Stress-tolerance

    Science.gov (United States)

    Hino, Akihiro

    Frozen dough method have been adopted in the baking industry to reduce labor and to produce fresh breads in stores. New freeze-tolerant yeasts for frozen dough preparations were isolated from banana peel and identified. To obtain strains that have fermentative ability even after several months of frozen storage in fermented dough, we attempted to breed new freeze-tolerantstrain. The hybrid between S.cerevisiae, which is a isolated freeze-tolerant strain, and a strain isolated from bakers' yeast with sexual conjugation gave a good quality bread made from frozen dough method. Freeze-tolerant strains showed higher surviving and trehalose accumulating abilities than freeze-sensitive strains. The freeze tolerance of the yeasts was associated with the basal amount of intracellular trehalose after rapid degradation at the onset of the prefermentation period. The complicated metabolic pathway and the regulation system of trehalose in yeast cells are introduced. The trehalose synthesis may act as a metabolic buffer system which contribute to maintain the intracellular inorganic phosphate and as a feedback regulation system in the glycolysis. However, it is not known enough how the trehalose protects yeast cells from stress.

  16. Modelling and design of high efficiency radiation tolerant indium phosphide space solar cells

    International Nuclear Information System (INIS)

    Goradia, C.; Geier, J.V.; Weinberg, I.

    1987-01-01

    Using a fairly comprehensive model, the authors did a parametric variation study of the InP shallow homojunction solar cell with a view to determining the maximum realistically achievable efficiency and an optimum design that would yield this efficiency. Their calculations show that with good quality epitaxial material, a BOL efficiency of about 20.3% at 1AMO, 25 0 C may be possible. The design parameters of the near-optimum cell are given. Also presented are the expected radiation damage of the performance parameters by 1MeV electrons and a possible explanation of the high radiation tolerance of InP solar cells

  17. Genome-wide mapping of autonomous promoter activity in human cells.

    Science.gov (United States)

    van Arensbergen, Joris; FitzPatrick, Vincent D; de Haas, Marcel; Pagie, Ludo; Sluimer, Jasper; Bussemaker, Harmen J; van Steensel, Bas

    2017-02-01

    Previous methods to systematically characterize sequence-intrinsic activity of promoters have been limited by relatively low throughput and the length of the sequences that could be tested. Here we present 'survey of regulatory elements' (SuRE), a method that assays more than 10 8 DNA fragments, each 0.2-2 kb in size, for their ability to drive transcription autonomously. In SuRE, a plasmid library of random genomic fragments upstream of a 20-bp barcode is constructed, and decoded by paired-end sequencing. This library is used to transfect cells, and barcodes in transcribed RNA are quantified by high-throughput sequencing. When applied to the human genome, we achieve 55-fold genome coverage, allowing us to map autonomous promoter activity genome-wide in K562 cells. By computational modeling we delineate subregions within promoters that are relevant for their activity. We show that antisense promoter transcription is generally dependent on the sense core promoter sequences, and that most enhancers and several families of repetitive elements act as autonomous transcription initiation sites.

  18. DOF-binding sites additively contribute to guard cell-specificity of AtMYB60 promoter

    Directory of Open Access Journals (Sweden)

    Cominelli Eleonora

    2011-11-01

    Full Text Available Abstract Background We previously demonstrated that the Arabidopsis thaliana AtMYB60 protein is an R2R3MYB transcription factor required for stomatal opening. AtMYB60 is specifically expressed in guard cells and down-regulated at the transcriptional levels by the phytohormone ABA. Results To investigate the molecular mechanisms governing AtMYB60 expression, its promoter was dissected through deletion and mutagenesis analyses. By studying different versions of AtMYB60 promoter::GUS reporter fusions in transgenic plants we were able to demonstrate a modular organization for the AtMYB60 promoter. Particularly we defined: a minimal promoter sufficient to confer guard cell-specific activity to the reporter gene; the distinct roles of different DOF-binding sites organised in a cluster in the minimal promoter in determining guard cell-specific expression; the promoter regions responsible for the enhancement of activity in guard cells; a promoter region responsible for the negative transcriptional regulation by ABA. Moreover from the analysis of single and multiple mutants we could rule out the involvement of a group of DOF proteins, known as CDFs, already characterised for their involvement in flowering time, in the regulation of AtMYB60 expression. Conclusions These findings shed light on the regulation of gene expression in guard cells and provide new promoter modules as useful tools for manipulating gene expression in guard cells, both for physiological studies and future biotechnological applications.

  19. An Alu-like RNA promotes cell differentiation and reduces malignancy of human neuroblastoma cells

    OpenAIRE

    Castelnuovo Manuele; Massone Sara; Tasso Roberta; Fiorino Gloria; Gatti Monica; Robello Mauro; Gatta Elena; Berger Audrey; Strub Katharina; Florio Tullio; Dieci Giorgio; Cancedda Ranieri; Pagano Aldo

    2010-01-01

    Neuroblastoma (NB) is a pediatric cancer characterized by remarkable cell heterogeneity within the tumor nodules. Here, we demonstrate that the synthesis of a pol III-transcribed noncoding (nc) RNA (NDM29) strongly restricts NB development by promoting cell differentiation, a drop of malignancy processes, and a dramatic reduction of the tumor initiating cell (TIC) fraction in the NB cell population. Notably, the overexpression of NDM29 also confers to malignant NB cells an unpredicted suscept...

  20. Multiple repair pathways mediate tolerance to chemotherapeutic cross-linking agents in vertebrate cells.

    Science.gov (United States)

    Nojima, Kuniharu; Hochegger, Helfrid; Saberi, Alihossein; Fukushima, Toru; Kikuchi, Koji; Yoshimura, Michio; Orelli, Brian J; Bishop, Douglas K; Hirano, Seiki; Ohzeki, Mioko; Ishiai, Masamichi; Yamamoto, Kazuhiko; Takata, Minoru; Arakawa, Hiroshi; Buerstedde, Jean-Marie; Yamazoe, Mitsuyoshi; Kawamoto, Takuo; Araki, Kasumi; Takahashi, Jun A; Hashimoto, Nobuo; Takeda, Shunichi; Sonoda, Eiichiro

    2005-12-15

    Cross-linking agents that induce DNA interstrand cross-links (ICL) are widely used in anticancer chemotherapy. Yeast genetic studies show that nucleotide excision repair (NER), Rad6/Rad18-dependent postreplication repair, homologous recombination, and cell cycle checkpoint pathway are involved in ICL repair. To study the contribution of DNA damage response pathways in tolerance to cross-linking agents in vertebrates, we made a panel of gene-disrupted clones from chicken DT40 cells, each defective in a particular DNA repair or checkpoint pathway, and measured the sensitivities to cross-linking agents, including cis-diamminedichloroplatinum (II) (cisplatin), mitomycin C, and melphalan. We found that cells harboring defects in translesion DNA synthesis (TLS), Fanconi anemia complementation groups (FANC), or homologous recombination displayed marked hypersensitivity to all the cross-linking agents, whereas NER seemed to play only a minor role. This effect of replication-dependent repair pathways is distinctively different from the situation in yeast, where NER seems to play a major role in dealing with ICL. Cells deficient in Rev3, the catalytic subunit of TLS polymerase Polzeta, showed the highest sensitivity to cisplatin followed by fanc-c. Furthermore, epistasis analysis revealed that these two mutants work in the same pathway. Our genetic comprehensive study reveals a critical role for DNA repair pathways that release DNA replication block at ICLs in cellular tolerance to cross-linking agents and could be directly exploited in designing an effective chemotherapy.

  1. Microbial stress tolerance for biofuels. Systems biology

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zonglin Lewis (ed.) [National Center for Agricultural Utilization Research, USDA-ARS, Peoria, IL (United States)

    2012-07-01

    The development of sustainable and renewable biofuels is attracting growing interest. It is vital to develop robust microbial strains for biocatalysts that are able to function under multiple stress conditions. This Microbiology Monograph provides an overview of methods for studying microbial stress tolerance for biofuels applications using a systems biology approach. Topics covered range from mechanisms to methodology for yeast and bacteria, including the genomics of yeast tolerance and detoxification; genetics and regulation of glycogen and trehalose metabolism; programmed cell death; high gravity fermentations; ethanol tolerance; improving biomass sugar utilization by engineered Saccharomyces; the genomics on tolerance of Zymomonas mobilis; microbial solvent tolerance; control of stress tolerance in bacterial host organisms; metabolomics for ethanologenic yeast; automated proteomics work cell systems for strain improvement; and unification of gene expression data for comparable analyses under stress conditions. (orig.)

  2. Effects of exogenous salicylic acid on cell wall polysaccharides and aluminum tolerance of trichosanthes kirilowii

    International Nuclear Information System (INIS)

    Xu, G.; Liu, D.; Xio, Y.; Liu, P.; Gao, P. P.; Cao, L.; Wu, Y.

    2015-01-01

    A hydroponic experiment was conducted to study the effects of exogenous salicylic acid (SA) on root length, relative aluminum content in the apical cell wall, acid phosphatase (APA) and pectin methyl esterase (PME) activity, root pectin, hemicellulose 1(HC1), and hemicellulose 2 (HC2) contents of Anguo Trichosanthes kirilowii (Al-tolerant genotype) and Pujiang T. kirilowii (Al-sensitive genotype) under 800 micro mol/L of aluminum stress. The results showed that the growth of Al-tolerant Anguo T. kirilowii and Al-sensitive Pujiang T. kirilowii was inhibited when exposed to 800 micro mol/L of aluminum solution. APA and PME activities were also enhanced for both genotypes. The contents of relative aluminum, pectin, HC1, and HC2, as well as Al accumulation in the root tips were increased under aluminum toxicity. Pujiang T. kirilowii showed higher enzyme activity and cell wall polysaccharide contents than Anguo T. kirilowii. In addition, the root cell wall pectin, HC1, and HC2 contents of Pujiang T. kirilowii were increased by a large margin, showing its greater sensitivity to aluminum toxicity. Root length is an important indicator of aluminum toxicity, and has an important relationship with cell wall polysaccharide content. Aluminum toxicity led to the accumulation of pectin and high PME activity, and also increased the number of free carboxyl groups, which have more aluminum binding sites. Membrane skim increased extensively with the increase in APA activity, damaging membrane structure and function. Different SA concentrations can decrease enzyme activity and cell wall polysaccharide content to some extent. With the addition of different SA concentrations, the root relative aluminum content, cell wall polysaccharide content, APA and PME activities decreased. Aluminum toxicity to both genotypes of T. kirilowii was relieved in different degrees as exogenous SA concentration increased. Inter-simple sequence repeat (ISSR) marker was used to examine the genetic distance

  3. Differentiation of human stem cells is promoted by amphiphilic pluronic block copolymers

    Directory of Open Access Journals (Sweden)

    Doğan A

    2012-09-01

    Full Text Available Aysegül Doğan,1 Mehmet E Yalvaç,1,2 Fikrettin Şahin,1 Alexander V Kabanov,3–5 András Palotás,6 Albert A Rizvanov71Department of Genetics and BioEngineering, College of Engineering and Architecture, Yeditepe University, Istanbul, Turkey; 2Center for Gene Therapy, Nationwide Children's Hospital, Ohio State University, Columbus, OH, USA; 3Center for Drug Delivery and Nanomedicine, 4Department of Pharmaceutical Sciences, College of Pharmacy, Durham Research Center, University of Nebraska Medical Center, Omaha, NE, USA; 5Laboratory of Chemical Design of Bio-nano-materials, Department of Chemistry, Mikhail V Lomonosov Moscow State University, Moscow, Russia; 6Asklepios-Med, Szeged, Hungary; 7Institute of Fundamental Medicine and Biology, Kazan (Volga Region Federal University, Kazan, RussiaAbstract: Stem cell usage provides novel avenues of tissue regeneration and therapeutics across disciplines. Apart from ethical considerations, the selection and amplification of donor stem cells remain a challenge. Various biopolymers with a wide range of properties have been used extensively to deliver biomolecules such as drugs, growth factors and nucleic acids, as well as to provide biomimetic surface for cellular adhesion. Using human tooth germ stem cells with high proliferation and transformation capacity, we have investigated a range of biopolymers to assess their potential for tissue engineering. Tolerability, toxicity, and their ability to direct differentiation were evaluated. The majority of pluronics, consisting of both hydrophilic and hydrophobic poly(ethylene oxide chains, either exerted cytotoxicity or had no significant effect on human tooth germ stem cells; whereas F68 increased the multi-potency of stem cells, and efficiently transformed them into osteogenic, chondrogenic, and adipogenic tissues. The data suggest that differentiation and maturation of stem cells can be promoted by selecting the appropriate mechanical and chemical

  4. PDGFBB promotes PDGFRα-positive cell migration into artificial bone in vivo

    International Nuclear Information System (INIS)

    Yoshida, Shigeyuki; Iwasaki, Ryotaro; Kawana, Hiromasa; Miyauchi, Yoshiteru; Hoshi, Hiroko; Miyamoto, Hiroya; Mori, Tomoaki; Kanagawa, Hiroya; Katsuyama, Eri; Fujie, Atsuhiro; Hao, Wu

    2012-01-01

    Highlights: ► We examined effects of PDGFBB in PDGFRα positive cell migration in artificial bones. ► PDGFBB was not expressed in osteoblastic cells but was expressed in peripheral blood cells. ► PDGFBB promoted PDGFRα positive cell migration into artificial bones but not osteoblast proliferation. ► PDGFBB did not inhibit osteoblastogenesis. -- Abstract: Bone defects caused by traumatic bone loss or tumor dissection are now treated with auto- or allo-bone graft, and also occasionally by artificial bone transplantation, particularly in the case of large bone defects. However, artificial bones often exhibit poor affinity to host bones followed by bony union failure. Thus therapies combining artificial bones with growth factors have been sought. Here we report that platelet derived growth factor bb (PDGFBB) promotes a significant increase in migration of PDGF receptor α (PDGFRα)-positive mesenchymal stem cells/pre-osteoblastic cells into artificial bone in vivo. Growth factors such as transforming growth factor beta (TGFβ) and hepatocyte growth factor (HGF) reportedly inhibit osteoblast differentiation; however, PDGFBB did not exhibit such inhibitory effects and in fact stimulated osteoblast differentiation in vitro, suggesting that combining artificial bones with PDGFBB treatment could promote host cell migration into artificial bones without inhibiting osteoblastogenesis.

  5. Chimerism and tolerance without GVHD or engraftment syndrome in HLA-mismatched combined kidney and hematopoietic stem cell transplantation.

    Science.gov (United States)

    Leventhal, Joseph; Abecassis, Michael; Miller, Joshua; Gallon, Lorenzo; Ravindra, Kadiyala; Tollerud, David J; King, Bradley; Elliott, Mary Jane; Herzig, Geoffrey; Herzig, Roger; Ildstad, Suzanne T

    2012-03-07

    The toxicity of chronic immunosuppressive agents required for organ transplant maintenance has prompted investigators to pursue approaches to induce immune tolerance. We developed an approach using a bioengineered mobilized cellular product enriched for hematopoietic stem cells (HSCs) and tolerogenic graft facilitating cells (FCs) combined with nonmyeloablative conditioning; this approach resulted in engraftment, durable chimerism, and tolerance induction in recipients with highly mismatched related and unrelated donors. Eight recipients of human leukocyte antigen (HLA)-mismatched kidney and FC/HSC transplants underwent conditioning with fludarabine, 200-centigray total body irradiation, and cyclophosphamide followed by posttransplant immunosuppression with tacrolimus and mycophenolate mofetil. Subjects ranged in age from 29 to 56 years. HLA match ranged from five of six loci with related donors to one of six loci with unrelated donors. The absolute neutrophil counts reached a nadir about 1 week after transplant, with recovery by 2 weeks. Multilineage chimerism at 1 month ranged from 6 to 100%. The conditioning was well tolerated, with outpatient management after postoperative day 2. Two subjects exhibited transient chimerism and were maintained on low-dose tacrolimus monotherapy. One subject developed viral sepsis 2 months after transplant and experienced renal artery thrombosis. Five subjects experienced durable chimerism, demonstrated immunocompetence and donor-specific tolerance by in vitro proliferative assays, and were successfully weaned off all immunosuppression 1 year after transplant. None of the recipients produced anti-donor antibody or exhibited engraftment syndrome or graft-versus-host disease. These results suggest that manipulation of a mobilized stem cell graft and nonmyeloablative conditioning represents a safe, practical, and reproducible means of inducing durable chimerism and donor-specific tolerance in solid organ transplant recipients.

  6. Carbon monoxide tolerant anodes for proton exchange membrane (PEM) fuel cells. 1. Catalyst development approach

    Energy Technology Data Exchange (ETDEWEB)

    Holleck, G L; Pasquariello, D M; Clauson, S L

    1998-07-01

    PEM fuel cells are highly attractive for distributed power and cogeneration systems. They are efficient and function virtually without noise or pollution. To be competitive PEM fuel cells must operate on fuel mixtures obtained by reforming of widely available natural gas or liquid hydrocarbons. Reformed fuel gas mixtures invariably contain CO, a strong poison for Pt. Therefore CO tolerant anode catalysts are essential for wide spread PEMFC introduction. It is the objective to develop effective CO tolerant fuel cell catalysts based on multi-component platinum-transition metal alloys. Towards this goal the authors have developed a novel approach for the synthesis and performance evaluation of multifunctional ternary alloy fuel cell catalysts. The alloys are prepared as well-defined thin films on standard TFE-bonded carbon substrates via a dc magnetron sputtering technique. The anodes are laminated to Nafion membranes and the electrochemical performance is measured in a representative fuel cell configuration with H{sub 2} and H{sub 2}/CO gas mixtures. The multi-target sputtering technique permits one to reproducibly synthesize true alloy films of controlled composition. The deposit morphology and electrode structure are determined by the standardized TFE bonded carbon substrate. The thin catalyst layer is concentrated at the electrode ionomer interface where it can be fully utilized in a representative fuel cell configuration. Thus, a true comparative fuel cell catalyst evaluation is possible. The effectiveness of this approach will be demonstrated with Pt, Pt-Ru and Pt-Ru-X catalyzed anodes.

  7. Tolerization of an established αb-crystallin-reactive T-cell response by intravenous antigen

    NARCIS (Netherlands)

    Verbeek, R.; Mark, K. van der; Wawrousek, E.F.; Plomp, A.C.; Noort, J.M. van

    2007-01-01

    Tolerance induction to prevent activation of a naïve T-cell repertoire has been well documented in rodents and can be readily achieved by intravenous, oral or intranasal administration of antigen in the absence of adjuvants. In autoimmune diseases such as multiple sclerosis (MS) the presence of an

  8. Stress-tolerant mutants induced by heavy-ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Tomoko; Yoshida, Shigeo [Institute of Physical and Chemical Research, Wako, Saitama (Japan); Bae, Chang-Hyu [Sunchon National University, Sunchon (Korea); Ozaki, Takuo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Wang, Jing Ming [Akita Prefectural Univ. (Japan)

    2000-07-01

    Comparative study was made on mutagenesis in tobacco embryo induced by exposure to EMS (ethyl methane-sulfonate) ion beams during the fertilization cycle. Tobacco embryo cells immediately after pollination were exposed to heavy ion beam and the sensitivity to the irradiation was assessed in each developmental stage and compared with the effects of EMS, a chemical mutagen. Morphologically abnormality such as chlorophyll deficiency was used as a marker. A total of 17 salt-tolerant plants were selected from 3447 M{sub 1} seeds. A cell line showed salt resistance. The cell growth and chlorophyll content were each two times higher than that of WT cells in the medium containing 154 mM NaCl. Seven strains of M{sub 3} progeny of 17 salt-tolerant plants, showed strong resistance, but no salt tolerant progeny were obtained from Xanthi or Ne-ion irradiation. This shows that the sensitivity of plant embryo to this irradiation technique may vary among species. When exposed to {sup 14}N ion beam for 24-108 hours after pollination, various morphological mutants appeared at 18% in M{sub 1} progeny and herbicide tolerant and salt tolerant mutants were obtained. A strong Co-tolerant strain was obtained in two of 17 salt-tolerant strains and a total of 46 tolerant strains (0.2%) were obtained from 22,272 grains of M{sub 1} seeds. In these tolerant strains, the absorption of Co was slightly decreased, but those of Mg and Mn were increased. Mutants induced with ion-beam irradiation have potential not only for practical use in the breeding of stress-tolerant plants but also for gene analysis that will surely facilitate the molecular understanding of the tolerance mechanisms. (M.N.)

  9. Identification of a novel temperature sensitive promoter in cho cells

    Directory of Open Access Journals (Sweden)

    Hesse Friedemann

    2011-05-01

    Full Text Available Abstract Background The Chinese hamster ovary (CHO expression system is the leading production platform for manufacturing biopharmaceuticals for the treatment of numerous human diseases. Efforts to optimize the production process also include the genetic construct encoding the therapeutic gene. Here we report about the successful identification of an endogenous highly active gene promoter obtained from CHO cells which shows conditionally inducible gene expression at reduced temperature. Results Based on CHO microarray expression data abundantly transcribed genes were selected as potential promoter candidates. The S100a6 (calcyclin and its flanking regions were identified from a genomic CHO-K1 lambda-phage library. Computational analyses showed a predicted TSS, a TATA-box and several TFBSs within the 1.5 kb region upstream the ATG start signal. Various constructs were investigated for promoter activity at 37°C and 33°C in transient luciferase reporter gene assays. Most constructs showed expression levels even higher than the SV40 control and on average a more than two-fold increase at lower temperature. We identified the core promoter sequence (222 bp comprising two SP1 sites and could show a further increase in activity by duplication of this minimal sequence. Conclusions This novel CHO promoter permits conditionally high-level gene expression. Upon a shift to 33°C, a two to three-fold increase of basal productivity (already higher than SV40 promoter is achieved. This property is of particular advantage for a process with reduced expression during initial cell growth followed by the production phase at low temperature with a boost in expression. Additionally, production of toxic proteins becomes feasible, since cell metabolism and gene expression do not directly interfere. The CHO S100a6 promoter can be characterized as cold-shock responsive with the potential for improving process performance of mammalian expression systems.

  10. T cell costimulation blockade promotes transplantation tolerance in combination with sirolimus and post-transplantation cyclophosphamide for haploidentical transplantation in children with severe aplastic anemia.

    Science.gov (United States)

    Jaiswal, Sarita Rani; Bhakuni, Prakash; Zaman, Shamsuz; Bansal, Satish; Bharadwaj, Priyanka; Bhargava, Sneh; Chakrabarti, Suparno

    2017-08-01

    We conducted a pilot study employing extended T cell costimulation blockade (COSBL) with Abatacept along with sirolimus and post-transplantation cyclophosphamide (PTCy) in 10 patients (median age 12) with severe aplastic anemia (SAA). Nine patients engrafted in the COSBL group, compared to all 10 patients (median 14 vs 13days) treated on PTCy protocols without abatacept (CONTROL group). The incidence of acute graft-versus-host disease (GVHD) was 10.5% in the COSBL group compared to 50% in the CONTROL group (p=0.04). Chronic GVHD (12.5% vs 56%, p=0.02) and CMV reactivation (30% vs 80%, p=0.03) were also reduced in the COSBL group. T and NK cell subset analysis revealed higher CD56 bright CD16 - NK cells in the CONTROL group (p=0.004), but similar CD56 dim CD16 + NK cells in both groups at day+30. Tregs (CD4 + CD25 + CD127 dim/- FoxP3+) were markedly higher in the COSBL group at day+30 (8.4% vs 1.1%) and the trend was maintained through day+90 (p<0.01). The GVHD and Disease-free survival at one year in the COSBL group was 80% vs. 30% in the CONTROL group (p=0.05). Our preliminary findings suggest that COSBL in combination with PTCy and sirolimus might augment transplantation tolerance in children with SAA, probably due to synergistic effect on early recovery of Tregs. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Bacterial lipoprotein-induced self-tolerance and cross-tolerance to LPS are associated with reduced IRAK-1 expression and MyD88-IRAK complex formation.

    LENUS (Irish Health Repository)

    Li, Chong Hui

    2012-02-03

    Tolerance to bacterial cell-wall components may represent an essential regulatory mechanism during bacterial infection. We have demonstrated previously that the inhibition of nuclear factor (NF)-kappaB and mitogen-activated protein kinase activation was present in bacterial lipoprotein (BLP) self-tolerance and its cross-tolerance to lipopolysaccharide (LPS). In this study, the effect of BLP-induced tolerance on the myeloid differentiation factor 88 (MyD88)-dependent upstream signaling pathway for NF-kappaB activation in vitro was examined further. When compared with nontolerant human monocytic THP-1 cells, BLP-tolerant cells had a significant reduction in tumor necrosis factor alpha (TNF-alpha) production in response to a high-dose BLP (86+\\/-12 vs. 6042+\\/-245 ng\\/ml, P < 0.01) or LPS (341+\\/-36 vs. 7882+\\/-318 ng\\/ml, P < 0.01) stimulation. The expression of Toll-like receptor 2 (TLR2) protein was down-regulated in BLP-tolerant cells, whereas no significant differences in TLR4, MyD88, interleukin-1 receptor-associated kinase 4 (IRAK-4), and TNF receptor-associated factor 6 expression were observed between nontolerant and BLP-tolerant cells, as confirmed by Western blot analysis. The IRAK-1 protein was reduced markedly in BLP-tolerant cells, although IRAK-1 mRNA expression remained unchanged as revealed by real-time reverse transcriptase-polymerase chain reaction analysis. Furthermore, decreased MyD88-IRAK immunocomplex formation, as demonstrated by immunoprecipitation, was observed in BLP-tolerant cells following a second BLP or LPS stimulation. BLP pretreatment also resulted in a marked inhibition in total and phosphorylated inhibitor of kappaB-alpha (IkappaB-alpha) expression, which was not up-regulated by subsequent BLP or LPS stimulation. These results demonstrate that in addition to the down-regulation of TLR2 expression, BLP tolerance is associated with a reduction in IRAK-1 expression, MyD88-IRAK association, and IkappaB-alpha phosphorylation. These

  12. B Cells Promote Th1- Skewed NKT Cell Response by CD1d-TCR Interaction

    OpenAIRE

    Shin, Jung Hoon; Park, Se-Ho

    2013-01-01

    CD1d expressing dendritic cells (DCs) are good glyco-lipid antigen presenting cells for NKT cells. However, resting B cells are very weak stimulators for NKT cells. Although ?-galactosylceramide (?-GalCer) loaded B cells can activate NKT cells, it is not well defined whether B cells interfere NKT cell stimulating activity of DCs. Unexpectedly, we found in this study that B cells can promote Th1-skewed NKT cell response, which means a increased level of IFN-? by NKT cells, concomitant with a d...

  13. Breaking Tolerance to Thyroid Antigens: Changing Concepts in Thyroid Autoimmunity

    Science.gov (United States)

    Rapoport, Basil

    2014-01-01

    Thyroid autoimmunity involves loss of tolerance to thyroid proteins in genetically susceptible individuals in association with environmental factors. In central tolerance, intrathymic autoantigen presentation deletes immature T cells with high affinity for autoantigen-derived peptides. Regulatory T cells provide an alternative mechanism to silence autoimmune T cells in the periphery. The TSH receptor (TSHR), thyroid peroxidase (TPO), and thyroglobulin (Tg) have unusual properties (“immunogenicity”) that contribute to breaking tolerance, including size, abundance, membrane association, glycosylation, and polymorphisms. Insight into loss of tolerance to thyroid proteins comes from spontaneous and induced animal models: 1) intrathymic expression controls self-tolerance to the TSHR, not TPO or Tg; 2) regulatory T cells are not involved in TSHR self-tolerance and instead control the balance between Graves' disease and thyroiditis; 3) breaking TSHR tolerance involves contributions from major histocompatibility complex molecules (humans and induced mouse models), TSHR polymorphism(s) (humans), and alternative splicing (mice); 4) loss of tolerance to Tg before TPO indicates that greater Tg immunogenicity vs TPO dominates central tolerance expectations; 5) tolerance is induced by thyroid autoantigen administration before autoimmunity is established; 6) interferon-α therapy for hepatitis C infection enhances thyroid autoimmunity in patients with intact immunity; Graves' disease developing after T-cell depletion reflects reconstitution autoimmunity; and 7) most environmental factors (including excess iodine) “reveal,” but do not induce, thyroid autoimmunity. Micro-organisms likely exert their effects via bystander stimulation. Finally, no single mechanism explains the loss of tolerance to thyroid proteins. The goal of inducing self-tolerance to prevent autoimmune thyroid disease will require accurate prediction of at-risk individuals together with an antigen

  14. Systemic immunological tolerance to ocular antigens is mediated by TNF-related apoptosis-inducing ligand (TRAIL)-expressing CD8+ T cells*

    OpenAIRE

    Griffith, Thomas S.; Brincks, Erik L.; Gurung, Prajwal; Kucaba, Tamara A.; Ferguson, Thomas A.

    2010-01-01

    Systemic immunological tolerance to Ag encountered in the eye restricts the formation of potentially damaging immune responses that would otherwise be initiated at other anatomical locations. We previously demonstrated that tolerance to Ag administered via the anterior chamber (AC) of the eye required FasL-mediated apoptotic death of inflammatory cells that enter the eye in response to the antigenic challenge. Moreover, the systemic tolerance induced after AC injection of Ag was mediated by C...

  15. Dietary Fiber and Bacterial SCFA Enhance Oral Tolerance and Protect against Food Allergy through Diverse Cellular Pathways.

    Science.gov (United States)

    Tan, Jian; McKenzie, Craig; Vuillermin, Peter J; Goverse, Gera; Vinuesa, Carola G; Mebius, Reina E; Macia, Laurence; Mackay, Charles R

    2016-06-21

    The incidence of food allergies in western countries has increased dramatically in recent decades. Tolerance to food antigens relies on mucosal CD103(+) dendritic cells (DCs), which promote differentiation of regulatory T (Treg) cells. We show that high-fiber feeding in mice improved oral tolerance and protected from food allergy. High-fiber feeding reshaped gut microbial ecology and increased the release of short-chain fatty acids (SCFAs), particularly acetate and butyrate. High-fiber feeding enhanced oral tolerance and protected against food allergy by enhancing retinal dehydrogenase activity in CD103(+) DC. This protection depended on vitamin A in the diet. This feeding regimen also boosted IgA production and enhanced T follicular helper and mucosal germinal center responses. Mice lacking GPR43 or GPR109A, receptors for SCFAs, showed exacerbated food allergy and fewer CD103(+) DCs. Dietary elements, including fiber and vitamin A, therefore regulate numerous protective pathways in the gastrointestinal tract, necessary for immune non-responsiveness to food antigens. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  16. Induction of tolerance and prolongation of islet allograft survival by syngeneic hematopoietic stem cell transplantation in mice.

    Science.gov (United States)

    Yang, Shi-feng; Xue, Wu-jun; Lu, Wan-hong; Xie, Li-yi; Yin, Ai-ping; Zheng, Jin; Sun, Ji-ping; Li, Yang

    2015-10-01

    Syngeneic or autologous hematopoietic stem cells transplantation (HSCT) has been proposed to treat autoimmune diseases because of its immunosuppressive and immunomodulatory effects, which can also contribute to posttransplant antirejection therapy. In this study, we explored the tolerogenic effect of syngeneic HSCT on prolonging islet allograft survival. C57BL/6 mice received syngeneic HSCT plus preconditioning with sublethal irradiation. Then islets of BALB/c mice were transplanted into the renal subcapsular of C57BL/6 mice after chemically induced into diabetes. HSCT mice exhibited improved islet allograft survival and increased serum insulin compared to control mice. Islet allografts of HSCT mice displayed lower level lymphocyte infiltration and stronger insulin staining than control mice. T cells of HSCT mice proliferated poorly in response to allogeneic splenocytes compared to control mice. Mice appeared reversed interferon-γ (IFN-γ)/interleukin-4 (IL-4) ratio to a Th2 immune deviation after syngeneic HSCT. The percentage of CD8(+) T cells was lower, while percentage of CD4(+)CD25(+)Foxp3(+) T regulatory cells (Tregs) was higher in HSCT mice than control mice. HSCT mice showed higher percentage of CTLA-4(+) T cells and expression of CTLA-4 mRNA than control mice. Targeting of CTLA-4 by intraperitoneal injection of anti-CTLA-4 mAb abrogated the effect of syngeneic HSCT on prolonging islet allograft survival, inhibiting activity of T cells in response to alloantigen, promoting Th1 to Th2 immune deviation and up regulating CD4(+)CD25(+)Foxp3(+) Tregs. Syngeneic HSCT plus preconditioning of sublethal irradiation induces tolerance and improves islet allograft survival in fully mismatched mice model. Th1 to Th2 immune deviation, increased CD4(+)CD25(+)Foxp3(+) Tregs and up-regulation of CTLA-4 maybe contribute to the tolerogenic effect induced by syngeneic HSCT. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Coniferyl aldehyde attenuates radiation enteropathy by inhibiting cell death and promoting endothelial cell function.

    Science.gov (United States)

    Jeong, Ye-Ji; Jung, Myung Gu; Son, Yeonghoon; Jang, Jun-Ho; Lee, Yoon-Jin; Kim, Sung-Ho; Ko, Young-Gyo; Lee, Yun-Sil; Lee, Hae-June

    2015-01-01

    Radiation enteropathy is a common complication in cancer patients. The aim of this study was to investigate whether radiation-induced intestinal injury could be alleviated by coniferyl aldehyde (CA), an HSF1-inducing agent that increases cellular HSP70 expression. We systemically administered CA to mice with radiation enteropathy following abdominal irradiation (IR) to demonstrate the protective effects of CA against radiation-induced gastrointestinal injury. CA clearly alleviated acute radiation-induced intestinal damage, as reflected by the histopathological data and it also attenuated sub-acute enteritis. CA prevented intestinal crypt cell death and protected the microvasculature in the lamina propria during the acute and sub-acute phases of damage. CA induced HSF1 and HSP70 expression in both intestinal epithelial cells and endothelial cells in vitro. Additionally, CA protected against not only the apoptotic cell death of both endothelial and epithelial cells but also the loss of endothelial cell function following IR, indicating that CA has beneficial effects on the intestine. Our results provide novel insight into the effects of CA and suggest its role as a therapeutic candidate for radiation-induced enteropathy due to its ability to promote rapid re-proliferation of the intestinal epithelium by the synergic effects of the inhibition of cell death and the promotion of endothelial cell function.

  18. Regulatory dendritic cells in autoimmunity: A comprehensive review.

    Science.gov (United States)

    Liu, Juan; Cao, Xuetao

    2015-09-01

    Dendritic cells (DCs) are professional antigen-presenting cells (APC) with significant phenotypic heterogeneity and functional plasticity. DCs play crucial roles in initiating effective adaptive immune responses for elimination of invading pathogens and also in inducing immune tolerance toward harmless components to maintain immune homeostasis. The regulatory capacity of DCs depends on their immature state and distinct subsets, yet not restricted to the immature state and one specialized subset. The tolerogenicity of DC is controlled by a complex network of environmental signals and cellular intrinsic mechanisms. Regulatory DCs play an important role in the maintenance of immunological tolerance via the induction of T cell unresponsiveness or apoptosis, and generation of regulatory T cells. DCs play essential roles in driving autoimmunity via promoting the activation of effector T cells such as T helper 1 and T helper 17 cells, and/or suppressing the generation of regulatory T cells. Besides, a breakdown of DCs-mediated tolerance due to abnormal environmental signals or breakdown of intrinsic regulatory mechanisms is closely linked with the pathogenesis of autoimmune diseases. Novel immunotherapy taking advantage of the tolerogenic potential of regulatory DCs is being developed for treatment of autoimmune diseases. In this review, we will describe the current understanding on the generation of regulatory DC and the role of regulatory DCs in promoting tolerogenic immune responses and suppressing autoimmune responses. The emerging roles of DCs dysfunction in the pathogenesis of autoimmune diseases and the potential application of regulatory DCs in the treatment of autoimmune diseases will also be discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. The Grape VlWRKY3 Gene Promotes Abiotic and Biotic Stress Tolerance in Transgenic Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Rongrong Guo

    2018-04-01

    Full Text Available WRKY transcription factors are known to play important roles in plant responses to various abiotic and biotic stresses. The grape WRKY gene, WRKY3 was previously reported to respond to salt and drought stress, as well as methyl jasmonate and ethylene treatments in Vitis labrusca × V. vinifera cv. ‘Kyoho.’ In the current study, WRKY3 from the ‘Kyoho’ grape cultivar was constitutively expressed in Arabidopsis thaliana under control of the cauliflower mosaic virus 35S promoter. The 35S::VlWRKY3 transgenic A. thaliana plants showed improved salt and drought stress tolerance during the germination, seedling and the mature plant stages. Various physiological traits related to abiotic stress responses were evaluated to gain further insight into the role of VlWRKY3, and it was found that abiotic stress caused less damage to the transgenic seedlings than to the wild-type (WT plants. VlWRKY3 over-expression also resulted in altered expression levels of abiotic stress-responsive genes. Moreover, the 35S::VlWRKY3 transgenic A. thaliana lines showed improved resistance to Golovinomyces cichoracearum, but increased susceptibility to Botrytis cinerea, compared with the WT plants. Collectively, these results indicate that VlWRKY3 plays important roles in responses to both abiotic and biotic stress, and modification of its expression may represent a strategy to enhance stress tolerance in crops.

  20. Immune tolerance in radiation chimeras

    International Nuclear Information System (INIS)

    Awaya, Kazuhiko; Kuniki, Hiromichi; Neki, Miyuki

    1978-01-01

    Establishment of immune tolerance in radiation chimeras and the mechanism of maintaining it were discussed from certain points. Semiallogeneic radiation chimeras are mostly of long-living, and the hematopoietic organ of this individual consists mainly of the cells derived from the marrow donor, i. e., F 1 -type cells. F 1 -type lymphocytes can distinguish parental strain cells from themselves. In these chimeras, a F 1 -skin graft maintains to be fresh as long as the host is alive, showing immune tolerance effective through its life. In establishment and maintenance of this immune tolerance, the suppressing mechanism of host-type or F 1 -type seems to be involved. The allogeneic radiation chimera has very poor long-survival rate compared with that of the semiallogeneic radiation chimera. To raise this survival rate, efforts are now being made from the immunological point of view. (Ueda, J.)

  1. Interaction between dendritic cells and natural killer cells during pregnancy in mice.

    Science.gov (United States)

    Blois, Sandra M; Barrientos, Gabriela; Garcia, Mariana G; Orsal, Arif S; Tometten, Mareike; Cordo-Russo, Rosalia I; Klapp, Burghard F; Santoni, Angela; Fernández, Nelson; Terness, Peter; Arck, Petra C

    2008-07-01

    A complex regulation of innate and adaptive immune responses at the maternal fetal interface promotes tolerance of trophoblast cells carrying paternally derived antigens. Such regulatory functions involve uterine dendritic cells (uDC) and natural killer (uNK) cells. The existence of a NK and DC "cross talk" has been revealed in various experimental settings; its biological significance ranging from cooperative stimulation to cell lysis. Little is known about the presence or role of NK and DC cross talk at the maternal fetal interface. The present study shows that mouse NK and DC interactions are subject to modulation by trophoblast cells in vitro. This interaction promotes a tolerogenic microenvironment characterized by downregulation of the expression of activation markers on uNK cells and uDC and dominance of Th2 cytokines. NK and DC interactions would also influence uterine cell proliferation and this process would be strongly modulated by trophoblast-derived signals. Indeed; while low proliferation rates were observed upon regular coculture allowing direct contact between uterine cells and trophoblasts, incubation in a transwell culture system markedly increased uterine cell proliferation suggesting that soluble factors are key mediators in the molecular "dialog" between the mother and the conceptus during the establishment of mouse pregnancy. Our data further reveal that the regulatory functions of trophoblast cells associated with tolerance induction are impaired in high abortion murine matings. Interestingly, we observed that secretion of interleukin-12p70 by uDC is dramatically abrogated in the presence of uNK cells. Taken together, our results provide the first evidence that a delicate balance of interactions involving NK cells, DC, and trophoblasts at the mouse maternal fetal interface supports a successful pregnancy outcome.

  2. HOXB4 Promotes Hemogenic Endothelium Formation without Perturbing Endothelial Cell Development

    Directory of Open Access Journals (Sweden)

    Nadine Teichweyde

    2018-03-01

    Full Text Available Summary: Generation of hematopoietic stem cells (HSCs from pluripotent stem cells, in vitro, holds great promise for regenerative therapies. Primarily, this has been achieved in mouse cells by overexpression of the homeotic selector protein HOXB4. The exact cellular stage at which HOXB4 promotes hematopoietic development, in vitro, is not yet known. However, its identification is a prerequisite to unambiguously identify the molecular circuits controlling hematopoiesis, since the activity of HOX proteins is highly cell and context dependent. To identify that stage, we retrovirally expressed HOXB4 in differentiating mouse embryonic stem cells (ESCs. Through the use of Runx1(−/− ESCs containing a doxycycline-inducible Runx1 coding sequence, we uncovered that HOXB4 promoted the formation of hemogenic endothelium cells without altering endothelial cell development. Whole-transcriptome analysis revealed that its expression mediated the upregulation of transcription of core transcription factors necessary for hematopoiesis, culminating in the formation of blood progenitors upon initiation of Runx1 expression. : In this article, Klump and colleagues demonstrate that the human homeotic selector protein HOXB4 promotes ESC-derived hematopoiesis by inducing hemogenic endothelium formation, in vitro. It propels hematopoietic specification by upregulating the transcription of genes essential for hematopoietic development, such as those encoding members of the so-called heptad transcription factors. Keywords: HOXB4, hematopoietic stem cells, hemangioblast, hemogenic endothelium, hematopoietic specification, EHT, RUNX1, pluripotent stem cells

  3. VEGF promotes tumorigenesis and angiogenesis of human glioblastoma stem cells

    International Nuclear Information System (INIS)

    Oka, Naoki; Soeda, Akio; Inagaki, Akihito; Onodera, Masafumi; Maruyama, Hidekazu; Hara, Akira; Kunisada, Takahiro; Mori, Hideki; Iwama, Toru

    2007-01-01

    There is increasing evidence for the presence of cancer stem cells (CSCs) in malignant brain tumors, and these CSCs may play a pivotal role in tumor initiation, growth, and recurrence. Vascular endothelial growth factor (VEGF) promotes the proliferation of vascular endothelial cells (VECs) and the neurogenesis of neural stem cells. Using CSCs derived from human glioblastomas and a retrovirus expressing VEGF, we examined the effects of VEGF on the properties of CSCs in vitro and in vivo. Although VEGF did not affect the property of CSCs in vitro, the injection of mouse brains with VEGF-expressing CSCs led to the massive expansion of vascular-rich GBM, tumor-associated hemorrhage, and high morbidity, suggesting that VEGF promoted tumorigenesis via angiogenesis. These results revealed that VEGF induced the proliferation of VEC in the vascular-rich tumor environment, the so-called stem cell niche

  4. IL-6 inhibits upregulation of membrane-bound TGF-beta 1 on CD4+ T cells and blocking IL-6 enhances oral tolerance

    Science.gov (United States)

    Kuhn, Chantal; Rezende, Rafael Machado; M'Hamdi, Hanane; da Cunha, Andre Pires; Weiner, Howard L.

    2016-01-01

    Oral administration of antigen induces regulatory T cells that express latent membrane-bound TGF-beta (LAP) and that have been shown to play an important role in the induction of oral tolerance. We developed an in vitro model to study modulation of LAP+ on CD4+ T cells. The combination of anti-CD3 mAb, anti-CD28 mAb and recombinant IL-2 induced expression of LAP on naïve CD4+ T cells, independent of FoxP3 or exogenous TGF-β. In vitro generated CD4+LAP+FoxP3− T cells were suppressive in vitro, inhibiting proliferation of naïve CD4+ T cells and IL-17A secretion by Th17 cells. Assessing the impact of different cytokines and neutralizing antibodies against cytokines we found that LAP induction was decreased in the presence of IL-6 and IL-21, and to a lesser extent by IL-4 and TNFα. IL-6 abrogated the in vitro induction of CD4+LAP+ T cells by STAT3 dependent inhibition of Lrrc32 (GARP), the adapter protein that tethers TGF-beta to the membrane. Oral tolerance induction was enhanced in mice lacking expression of IL-6R by CD4+ T cells and by treatment of wild-type mice with neutralizing anti-IL-6 mAb. These results suggest that pro-inflammatory cytokines interfere with oral tolerance induction and that blocking the IL-6 pathway is a potential strategy for enhancing oral tolerance in the setting of autoimmune and inflammatory diseases. PMID:28039301

  5. Mussel-inspired alginate gel promoting the osteogenic differentiation of mesenchymal stem cells and anti-infection

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Shiwen [Department of Mechanical Engineering, Faculty of Engineering and Department of Biochemistry & Genetics, Faculty of Medicine and Manitoba Institute of Child Health, The University of Manitoba, Winnipeg, Manitoba (Canada); Children Hospital Research Institute of Manitoba, Winnipeg (Canada); Sichuan University, Chengdu (China); Xu, Kaige; Darabi, Mohammad Ali [Children Hospital Research Institute of Manitoba, Winnipeg (Canada); Yuan, Quan [Sichuan University, Chengdu (China); Xing, Malcolm [Department of Mechanical Engineering, Faculty of Engineering and Department of Biochemistry & Genetics, Faculty of Medicine and Manitoba Institute of Child Health, The University of Manitoba, Winnipeg, Manitoba (Canada)

    2016-12-01

    Alginate hydrogels have been used in cell encapsulation for many years but a prevalent issue with pure alginates is that they are unable to provide enough bioactive properties to interact with mammalian cells. This paper discusses the modification of alginate with mussel-inspired dopamine for cell loading and anti-infection. Mouse bone marrow stem cells were immobilized into alginate and alginate-dopamine beads and fibers. Through live-dead and MTT assay, alginates modified by dopamine promoted cell viability and proliferation. In vitro cell differentiation results showed that such an alginate-dopamine gel can promote the osteogenic differentiation of mesenchymal stem cell after PCR and ALP assays. In addition to that, the adhesive prosperities of dopamine allowed for coating the surface of alginate-dopamine gel with silver nanoparticles, which provided the gel with significant antibacterial characteristics. Overall, these results demonstrate that a dopamine-modified alginate gel can be a great tool for cell encapsulation to promote cell proliferation and can be applied to bone regeneration, especially in contaminated bone defects. - Highlights: • Dopamine modified alginate bead and fiber promote cell viability and proliferation. • Alginate-dopamine gel promotes osteogenic differentiation of MSCs. • Dopamine reduced nanosilver for anti-infection. • Alginate-dopamine bead and fiber for delivery of mesenchymal stem cells (MSCs)

  6. Mussel-inspired alginate gel promoting the osteogenic differentiation of mesenchymal stem cells and anti-infection

    International Nuclear Information System (INIS)

    Zhang, Shiwen; Xu, Kaige; Darabi, Mohammad Ali; Yuan, Quan; Xing, Malcolm

    2016-01-01

    Alginate hydrogels have been used in cell encapsulation for many years but a prevalent issue with pure alginates is that they are unable to provide enough bioactive properties to interact with mammalian cells. This paper discusses the modification of alginate with mussel-inspired dopamine for cell loading and anti-infection. Mouse bone marrow stem cells were immobilized into alginate and alginate-dopamine beads and fibers. Through live-dead and MTT assay, alginates modified by dopamine promoted cell viability and proliferation. In vitro cell differentiation results showed that such an alginate-dopamine gel can promote the osteogenic differentiation of mesenchymal stem cell after PCR and ALP assays. In addition to that, the adhesive prosperities of dopamine allowed for coating the surface of alginate-dopamine gel with silver nanoparticles, which provided the gel with significant antibacterial characteristics. Overall, these results demonstrate that a dopamine-modified alginate gel can be a great tool for cell encapsulation to promote cell proliferation and can be applied to bone regeneration, especially in contaminated bone defects. - Highlights: • Dopamine modified alginate bead and fiber promote cell viability and proliferation. • Alginate-dopamine gel promotes osteogenic differentiation of MSCs. • Dopamine reduced nanosilver for anti-infection. • Alginate-dopamine bead and fiber for delivery of mesenchymal stem cells (MSCs)

  7. Implications of the quadratic cell survival curve and human skin radiation ''tolerance doses'' on fractionation and superfractionation dose selection

    International Nuclear Information System (INIS)

    Douglas, B.G.

    1982-01-01

    An analysis of early published multifraction orthovoltage human acute skin irradiation tolerance isoeffect doses is presented. It indicates that human acute skin radiation reactions may result from the repetition, with each dose fraction, of a cell survival curve of the form: S = e/sup -(αD + βD 2 )/). The analysis also shows no need for an independent proliferation related time factor for skin, for daily treatments of six weeks or less in duration. The value obtained for the constant β/α for orthovoltage irradiation from these data is 2.9 x 10 -3 rad -1 for the cell line determining acute skin tolerance. A radiation isoeffect relationship, based on the quadratic cell survival curve, is introduced for human skin. This relationship has some advantages over the nominal standard dose (NSD). First, its use is not restricted to tolerance level reactions. Second, a modification of the relationship, which is also introduced, may be employed in the selection of doses per treatment when irradiation dose fractions are administered at short intervals where repair of sublethal injury is incomplete

  8. Double overexpression of DREB and PIF transcription factors improves drought stress tolerance and cell elongation in transgenic plants.

    Science.gov (United States)

    Kudo, Madoka; Kidokoro, Satoshi; Yoshida, Takuya; Mizoi, Junya; Todaka, Daisuke; Fernie, Alisdair R; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

    2017-04-01

    Although a variety of transgenic plants that are tolerant to drought stress have been generated, many of these plants show growth retardation. To improve drought tolerance and plant growth, we applied a gene-stacking approach using two transcription factor genes: DEHYDRATION-RESPONSIVE ELEMENT-BINDING 1A (DREB1A) and rice PHYTOCHROME-INTERACTING FACTOR-LIKE 1 (OsPIL1). The overexpression of DREB1A has been reported to improve drought stress tolerance in various crops, although it also causes a severe dwarf phenotype. OsPIL1 is a rice homologue of Arabidopsis PHYTOCHROME-INTERACTING FACTOR 4 (PIF4), and it enhances cell elongation by activating cell wall-related gene expression. We found that the OsPIL1 protein was more stable than PIF4 under light conditions in Arabidopsis protoplasts. Transactivation analyses revealed that DREB1A and OsPIL1 did not negatively affect each other's transcriptional activities. The transgenic plants overexpressing both OsPIL1 and DREB1A showed the improved drought stress tolerance similar to that of DREB1A overexpressors. Furthermore, double overexpressors showed the enhanced hypocotyl elongation and floral induction compared with the DREB1A overexpressors. Metabolome analyses indicated that compatible solutes, such as sugars and amino acids, accumulated in the double overexpressors, which was similar to the observations of the DREB1A overexpressors. Transcriptome analyses showed an increased expression of abiotic stress-inducible DREB1A downstream genes and cell elongation-related OsPIL1 downstream genes in the double overexpressors, which suggests that these two transcription factors function independently in the transgenic plants despite the trade-offs required to balance plant growth and stress tolerance. Our study provides a basis for plant genetic engineering designed to overcome growth retardation in drought-tolerant transgenic plants. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology

  9. Beta-cell function, incretin effect, and incretin hormones in obese youth along the span of glucose tolerance from normal to prediabetes to Type 2 diabetes

    Science.gov (United States)

    Using the hyperglycemic and euglycemic clamp, we demonstrated impaired Beta-cell function in obese youth with increasing dysglycemia. Herein we describe oral glucose tolerance test (OGTT)-modeled Beta-cell function and incretin effect in obese adolescents spanning the range of glucose tolerance. Bet...

  10. Overexpression of persimmon DkXTH1 enhanced tolerance to abiotic stress and delayed fruit softening in transgenic plants.

    Science.gov (United States)

    Han, Ye; Han, Shoukun; Ban, Qiuyan; He, Yiheng; Jin, Mijing; Rao, Jingping

    2017-04-01

    DkXTH1 promoted cell elongation and more strength to maintain structural integrity by involving in cell wall assembly, thus enhanced tolerance to abiotic stress with broader phenotype in transgenic plants. Xyloglucan endotransglucosylase/hydrolase (XTH) is thought to play a key role in cell wall modifications by cleaving and re-joining xyloglucan, and participates in the diverse physiological processes. DkXTH1 was found to peak in immature expanding persimmon fruit, and its higher expression level exhibited along with firmer fruit during storage. In the present study, transgenic Arabidopsis and tomato plants were generated with DkXTH1 constitutively expressed. Overexpression of DkXTH1 enhanced tolerance to salt, ABA and drought stresses in transgenic Arabidopsis plants with respect to root and leaf growth, and survival. Transgenic tomatoes collected at the mature green stage, presented delayed fruit softening coupled with postponed color change, a later and lower ethylene peak, and higher firmness in comparison with the wild-type tomatoes during storage. Furthermore, broader leaves and tomato fruit with larger diameter were gained in transgenic Arabidopsis and tomato, respectively. Most importantly, transgenic plants exhibited more large and irregular cells with higher density of cell wall and intercellular spaces, resulting from the overactivity of XET enzymes involving in cell wall assembly. We suggest that DkXTH1 expression resulted in cells with more strength and thickness to maintain structural integrity, and thus enhanced tolerance to abiotic stress and delayed fruit softening in transgenic plants.

  11. Study of calcium-dependent lead-tolerance on plants differing in their level of Ca-deficiency tolerance

    International Nuclear Information System (INIS)

    Antosiewicz, Danuta Maria

    2005-01-01

    The main aim of the study was to determine the role of calcium in the amelioration of lead toxic effects in plants with accordingly high/low level of Pb-tolerance and high/low Ca-deficiency tolerance. The study was performed on maize, rye, tomato and mustard. Plants were cultivated in modified Knop's solution. They were subjected to Ca-deficiency, and to lead nitrate administered in the presence of four calcium nitrate concentrations 3.0, 2.4, 1.2, 0.3 mM. Lead-tolerance and tolerance to Ca-deficiency were determined, as were concentration of the studied elements in plant tissues, and the Pb deposition pattern at the ultrastructural level (electron microscopy study, X-ray microanalysis). In all studied plants, lead toxicity increased as medium calcium content decreased, however, only in the Ca-deficiency sensitive mustard with low Pb-tolerance was it accompanied by a rise in tissue lead concentration. In contrast, lead root and shoot levels did not increase in the highly Ca-deficiency tolerant tomato, mustard and rye with high Pb-tolerance irrespective of the Ca 2+ regimens applied. Thus, in these plants, lead's unfavourable effects resulted only from the higher toxicity of the same amount of lead in tissues at low calcium in the medium. Of particular relevance is the finding by electron microscopy and X-ray microanalysis, that under low calcium in both highly Ca-deficiency tolerant and Ca-deficiency sensitive plants, less efficient Pb 2+ detoxification was accompanied by the restriction of the formation of large lead deposits in cell walls. Obtained results are novel in demonstrating calcium involvement in the lead deposition in the cell wall, thus in the regulation of the internal lead detoxification. - Calcium regulated lead deposition in cell walls of plants

  12. Tolerance and immunity in mice infected with herpes simplex virus: studies on the mechanism of tolerance to delayed-type hypersensitivity.

    Science.gov (United States)

    Nash, A A; Phelan, J; Gell, P G; Wildy, P

    1981-06-01

    Tolerance to delayed-type hypersensitivity is produced in mice following an intravenous injection of herpes simplex virus. This form of tolerance is produced early on, following simultaneous injections of virus subcutaneously and intravenously, and is long lasting (greater than 100 days). The early tolerance mechanism is resistant to high doses of cyclophosphamide and is not transferable by serum or spleen cells taken after 7 days. However, spleen cells taken at 14 days onwards inhibit the induction of delayed hypersensitivity when transferred to normal syngeneic recipients. These cells are T lymphocytes and are specific for the herpes type used in the induction.

  13. Breaking Immunological Tolerance through OX40 (CD134

    Directory of Open Access Journals (Sweden)

    Pratima Bansal-Pakala

    2001-01-01

    Full Text Available Immunological tolerance represents a mechanism by which cells of the host remain protected from the immune system. Breaking of immunological tolerance can result in a variety of autoimmune diseases such as rheumatoid arthritis, diabetes, and multiple sclerosis. The reasons for tolerance breaking down and autoimmune processes arising are largely unknown but of obvious interest for therapeutic intervention of these diseases. Although reversal of the tolerant state is generally unwanted, there are instances where this may be of benefit to the host. In particular, one way a cancerous cell escapes being targeted by the immune system is through tolerance mechanisms that in effect turn off the reactivity of T lymphocytes that can respond to tumor-associated peptides. Thus tolerance represents a major obstacle in developing effective immunotherapy against tumors. The molecules that are involved in regulating immunological tolerance are then of interest as they may be great targets for positively or negatively manipulating the tolerance process.

  14. Functional transforming growth factor-β receptor type II expression by CD4+ T cells in Peyer's patches is essential for oral tolerance induction.

    Directory of Open Access Journals (Sweden)

    Rebekah S Gilbert

    Full Text Available Our previous studies have shown that Peyer's patches (PPs play a key role in the induction of oral tolerance. Therefore, we hypothesized that PPs are an important site for Transforming Growth Factor (TGF-β signaling and sought to prove that this tissue is of importance in oral tolerance induction. We found that expression of TGF-β type II receptor (TGFβRII by CD4(+ T cells increases and persists in the PPs of normal C57BL/6 mice after either high- or low-dose feeding of OVA when compared to mesenteric lymph nodes (MLNs and spleen. Approximately one-third of these TGFβRII(+ CD4(+ T cells express the transcription factor Foxp3. Interestingly, the number of TGFβRII(+ CD4(+ T cells in PPs decreased when OVA-fed mice were orally challenged with OVA plus native cholera toxin (CT. In contrast, numbers of TGFβRII(+ CD4(+ T cells were increased in the intestinal lamina propria (iLP of these challenged mice. Further, these PP CD4(+ TGFβRII(+ T cells upregulated Foxp3 within 2 hours after OVA plus CT challenge. Mice fed PBS and challenged with OVA plus CT did not reveal any changes in TGFβRII expression by CD4(+ T cells. In order to test the functional property of TGFβRII in the induction of oral tolerance, CD4dnTGFβRII transgenic mice, in which TGFβRII signaling is abrogated from all CD4(+ T cells, were employed. Importantly, these mice could not develop oral tolerance to OVA. Our studies show a critical, dose-independent, role for TGFβRII expression and function by CD4(+ T cells in the gut-associated lymphoid tissues, further underlining the vital role of PPs in oral tolerance.

  15. Reverting antibiotic tolerance of Pseudomonas aeruginosa PAO1 persister cells by (Z-4-bromo-5-(bromomethylene-3-methylfuran-2(5H-one.

    Directory of Open Access Journals (Sweden)

    Jiachuan Pan

    Full Text Available BACKGROUND: Bacteria are well known to form dormant persister cells that are tolerant to most antibiotics. Such intrinsic tolerance also facilitates the development of multidrug resistance through acquired mechanisms. Thus persister cells are a promising target for developing more effective methods to control chronic infections and help prevent the development of multidrug-resistant bacteria. However, control of persister cells is still an unmet challenge. METHODOLOGY/PRINCIPAL FINDINGS: We show in this report that (Z-4-bromo-5-(bromomethylene-3-methylfuran-2(5H-one (BF8 can restore the antibiotic susceptibility of Pseudomonas aeruginosa PAO1 persister cells at growth non-inhibitory concentrations. Persister control by BF8 was found to be effective against both planktonic and biofilm cells of P. aeruginosa PAO1. Interestingly, although BF8 is an inhibitor of quorum sensing (QS in Gram-negative bacteria, the data in this study suggest that the activities of BF8 to revert antibiotic tolerance of P. aeruginosa PAO1 persister cells is not through QS inhibition and may involve other targets. CONCLUSION: BF8 can sensitize P. aeruginosa persister cells to antibiotics.

  16. Plant-based oral tolerance to hemophilia therapy employs a complex immune regulatory response including LAP+CD4+ T cells

    OpenAIRE

    Wang, Xiaomei; Su, Jin; Sherman, Alexandra; Rogers, Geoffrey L.; Liao, Gongxian; Hoffman, Brad E.; Leong, Kam W.; Terhorst, Cox; Daniell, Henry; Herzog, Roland W.

    2015-01-01

    Coadministering FIX orally and systemically induces tolerance via complex immune regulation, involving tolerogenic dendritic and T-cell subsets.Induced CD4+CD25−LAP+ regulatory T cells with increased IL-10 and TGF-β expression and CD4+CD25+ regulatory T cells suppress antibody formation against FIX.

  17. Role of glutathione metabolism status in the definition of some cellular parameters and oxidative stress tolerance of Saccharomyces cerevisiae cells growing as biofilms.

    Science.gov (United States)

    Gales, Grégoire; Penninckx, Michel; Block, Jean-Claude; Leroy, Pierre

    2008-08-01

    The resistance of Saccharomyces cerevisiae to oxidative stress (H(2)O(2) and Cd(2+)) was compared in biofilms and planktonic cells, with the help of yeast mutants deleted of genes related to glutathione metabolism and oxidative stress. Biofilm-forming cells were found predominantly in the G1 stage of the cell cycle. This might explain their higher tolerance to oxidative stress and the young replicative age of these cells in an old culture. The reduced glutathione status of S. cerevisiae was affected by the growth phase and apparently plays an important role in oxidative stress tolerance in cells growing as a biofilm.

  18. Increased degradation of ATP is driven by memory regulatory T cells in kidney transplantation tolerance.

    Science.gov (United States)

    Durand, Maxim; Dubois, Florian; Dejou, Cécile; Durand, Eugénie; Danger, Richard; Chesneau, Mélanie; Brosseau, Carole; Guerif, Pierrick; Soulillou, Jean-Paul; Degauque, Nicolas; Eliaou, Jean-François; Giral, Magali; Bonnefoy, Nathalie; Brouard, Sophie

    2018-05-01

    Regulatory T cells were recently proposed as the central actor in operational tolerance after renal transplantation. Tolerant patients harbor increased FoxP3hi memory Treg frequency and increased demethylation in the Foxp3 Treg-specific demethylated region when compared to stable kidney recipients and exhibit greater memory Treg suppressive capacities and higher expression of the ectonucleotidase CD39. However, in this particular and unique situation the mechanisms of action of Tregs were not identified. Thus, we analyzed the ability of memory Tregs to degrade extracellular ATP in tolerant patients, healthy volunteers, and patients with stable graft function under immunosuppression and determined the role of immunosuppressive drugs on this process. The conserved proportion of memory Tregs leads to the establishment of a pro-tolerogenic balance in operationally tolerant patients. Memory Tregs in tolerant patients display normal capacity to degrade extracellular ATP/ADP. In contrast, memory Tregs from patients with stable graft function do not have this ability. Finally, in vitro, immunosuppressive drugs may favor the lower proportion of memory Tregs in stable patients, but they have no effect on CD39-dependent ATP degradation and do not explain memory Treg lack of extracellular ATP/ADP degradation ability. Thus, intrinsic active regulatory mechanisms may act long after immunosuppressive drug arrest in operationally tolerant patients and may contribute to kidney allograft tolerance via the maintenance of CD39 Treg function. Copyright © 2018 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  19. Physiological and proteomic changes suggest an important role of cell walls in the high tolerance to metals of Elodea nuttallii.

    Science.gov (United States)

    Larras, Floriane; Regier, Nicole; Planchon, Sébastien; Poté, John; Renaut, Jenny; Cosio, Claudia

    2013-12-15

    Macrophytes bioaccumulate metals, the suggestion being made that they be considered for phytoremediation. However, a thorough understanding of the mechanisms of metal tolerance in these plants is necessary to allow full optimization of this approach. The present study was undertaken to gain insight into Hg and Cd accumulation and their effects in a representative macrophyte, Elodea nuttallii. Exposure to methyl-Hg (23 ng dm(-3)) had no significant effect while inorganic Hg (70 ng dm(-3)) and Cd (281 μg dm(-3)) affected root growth but did not affect shoots growth, photosynthesis, or antioxidant enzymes. Phytochelatins were confirmed as having a role in Cd tolerance in this plant while Hg tolerance seems to rely on different mechanisms. Histology and subcellular distribution revealed a localized increase in lignification, and an increased proportion of metal accumulation in cell wall over time. Proteomics further suggested that E. nuttallii was able to efficiently adapt its energy sources and the structure of its cells during Hg and Cd exposure. Storage in cell walls to protect cellular machinery is certainly predominant at environmental concentrations of metals in this plant resulting in a high tolerance highlighted by the absence of toxicity symptoms in shoots despite the significant accumulation of metals. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Performance Factors and Sulfur Tolerance of Metal Supported Solid Oxide Fuel Cells with Nanostructured Ni:GDC Infiltrated Anodes

    DEFF Research Database (Denmark)

    Nielsen, Jimmi; Sudireddy, Bhaskar Reddy; Hagen, Anke

    2015-01-01

    at a current load of 0.25Acm-2. The results were compared with literature on the sulfur tolerance of the conventional SOFC Ni/YSZ cermet anode. The comparison in terms of absolute cell resistance increase and relative anode polarization resistance increase indicate, that the nanostructured Ni:GDC MS-SOFC based...... anode is significantly more sulfur tolerant than the conventional Ni/YSZ cermet anode. © 2015 ECS - The Electrochemical Society...

  1. Cocktail of chemical compounds robustly promoting cell reprogramming protects liver against acute injury

    Directory of Open Access Journals (Sweden)

    Yuewen Tang

    2017-02-01

    Full Text Available Abstract Tissue damage induces cells into reprogramming-like cellular state, which contributes to tissue regeneration. However, whether factors promoting the cell reprogramming favor tissue regeneration remains elusive. Here we identified combination of small chemical compounds including drug cocktails robustly promoting in vitro cell reprogramming. We then administrated the drug cocktails to mice with acute liver injuries induced by partial hepatectomy or toxic treatment. Our results demonstrated that the drug cocktails which promoted cell reprogramming in vitro improved liver regeneration and hepatic function in vivo after acute injuries. The underlying mechanism could be that expression of pluripotent genes activated after injury is further upregulated by drug cocktails. Thus our study offers proof-of-concept evidence that cocktail of clinical compounds improving cell reprogramming favors tissue recovery after acute damages, which is an attractive strategy for regenerative purpose.

  2. Comparing passive angle-torque curves recorded simultaneously with a load cell versus an isokinetic dynamometer during dorsiflexion stretch tolerance assessments.

    Science.gov (United States)

    Buckner, Samuel L; Jenkins, Nathaniel D M; Costa, Pablo B; Ryan, Eric D; Herda, Trent J; Cramer, Joel T

    2015-05-01

    The purpose of the present study was to compare the passive angle-torque curves and the passive stiffness (PS, N m °(-)(1)) values recorded simultaneously from a load cell versus an isokinetic dynamometer during dorsiflexion stretch tolerance assessments in vivo. Nine healthy men (mean ± SD age = 21.4 ± 1.6 years) completed stretch tolerance assessments on a custom-built apparatus where passive torque was measured simultaneously from an isokinetic dynamometer and a load cell. Passive torque values that corresponded with the last 10° of dorsiflexion, verified by surface electromyographic amplitude, were analyzed for each device (θ1, θ2, θ3, …, θ10). Passive torque values measured with the load cell were greater (p ≤ 0.05) than the dynamometer torque values for θ4 through θ10. There were more statistical differentiations among joint angles for passive torque measured by the load cell, and the load cell measured a greater (p ≤ 0.01) increase in passive torque and PS than the isokinetic dynamometer. These findings suggested that when examining the angle-torque curves from passive dorsiflexion stretch tolerance tests, a load cell placed under the distal end of the foot may be more sensitive than the torque recorded from an isokinetic dynamometer. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

  3. IL-6 Inhibits Upregulation of Membrane-Bound TGF-β 1 on CD4+ T Cells and Blocking IL-6 Enhances Oral Tolerance.

    Science.gov (United States)

    Kuhn, Chantal; Rezende, Rafael Machado; M'Hamdi, Hanane; da Cunha, Andre Pires; Weiner, Howard L

    2017-02-01

    Oral administration of Ag induces regulatory T cells that express latent membrane-bound TGF-β (latency-associated peptide [LAP]) and have been shown to play an important role in the induction of oral tolerance. We developed an in vitro model to study modulation of LAP + on CD4 + T cells. The combination of anti-CD3 mAb, anti-CD28 mAb, and recombinant IL-2 induced expression of LAP on naive CD4 + T cells, independent of Foxp3 or exogenous TGF-β. In vitro generated CD4 + LAP + Foxp3 - T cells were suppressive in vitro, inhibiting proliferation of naive CD4 + T cells and IL-17A secretion by Th17 cells. Assessing the impact of different cytokines and neutralizing Abs against cytokines, we found that LAP induction was decreased in the presence of IL-6 and IL-21, and to a lesser extent by IL-4 and TNF-α. IL-6 abrogated the in vitro induction of CD4 + LAP + T cells by STAT3-dependent inhibition of Lrrc32 (glycoprotein A repetitions predominant [GARP]), the adapter protein that tethers TGF-β to the membrane. Oral tolerance induction was enhanced in mice lacking expression of IL-6R by CD4 + T cells and by treatment of wild-type mice with neutralizing anti-IL-6 mAb. These results suggest that proinflammatory cytokines interfere with oral tolerance induction and that blocking the IL-6 pathway is a potential strategy for enhancing oral tolerance in the setting of autoimmune and inflammatory diseases. Copyright © 2017 by The American Association of Immunologists, Inc.

  4. Sorafenib-induced defective autophagy promotes cell death by necroptosis.

    Science.gov (United States)

    Kharaziha, Pedram; Chioureas, Dimitris; Baltatzis, George; Fonseca, Pedro; Rodriguez, Patricia; Gogvadze, Vladimir; Lennartsson, Lena; Björklund, Ann-Charlotte; Zhivotovsky, Boris; Grandér, Dan; Egevad, Lars; Nilsson, Sten; Panaretakis, Theocharis

    2015-11-10

    Autophagy is one of the main cytoprotective mechanisms that cancer cells deploy to withstand the cytotoxic stress and survive the lethal damage induced by anti-cancer drugs. However, under specific conditions, autophagy may, directly or indirectly, induce cell death. In our study, treatment of the Atg5-deficient DU145 prostate cancer cells, with the multi-tyrosine kinase inhibitor, sorafenib, induces mitochondrial damage, autophagy and cell death. Molecular inhibition of autophagy by silencing ULK1 and Beclin1 rescues DU145 cells from cell death indicating that, in this setting, autophagy promotes cell death. Re-expression of Atg5 restores the lipidation of LC3 and rescues DU145 and MEF atg5-/- cells from sorafenib-induced cell death. Despite the lack of Atg5 expression and LC3 lipidation, DU145 cells form autophagosomes as demonstrated by transmission and immuno-electron microscopy, and the formation of LC3 positive foci. However, the lack of cellular content in the autophagosomes, the accumulation of long-lived proteins, the presence of GFP-RFP-LC3 positive foci and the accumulated p62 protein levels indicate that these autophagosomes may not be fully functional. DU145 cells treated with sorafenib undergo a caspase-independent cell death that is inhibited by the RIPK1 inhibitor, necrostatin-1. Furthermore, treatment with sorafenib induces the interaction of RIPK1 with p62, as demonstrated by immunoprecipitation and a proximity ligation assay. Silencing of p62 decreases the RIPK1 protein levels and renders necrostatin-1 ineffective in blocking sorafenib-induced cell death. In summary, the formation of Atg5-deficient autophagosomes in response to sorafenib promotes the interaction of p62 with RIPK leading to cell death by necroptosis.

  5. Enhanced water stress tolerance of transgenic maize plants over-expressing LEA Rab28 gene.

    Science.gov (United States)

    Amara, Imen; Capellades, Montserrat; Ludevid, M Dolors; Pagès, Montserrat; Goday, Adela

    2013-06-15

    Late Embryogenesis Abundant (LEA) proteins participate in plant stress responses and contribute to the acquisition of desiccation tolerance. In this report Rab28 LEA gene has been over-expressed in maize plants under a constitutive maize promoter. The expression of Rab28 transcripts led to the accumulation and stability of Rab28 protein in the transgenic plants. Native Rab28 protein is localized to nucleoli in wild type maize embryo cells; here we find by whole-mount immunocytochemistry that in root cells of Rab28 transgenic and wild-type plants the protein is also associated to nucleolar structures. Transgenic plants were tested for stress tolerance and resulted in sustained growth under polyethyleneglycol (PEG)-mediated dehydration compared to wild-type controls. Under osmotic stress transgenic seedlings showed increased leaf and root areas, higher relative water content (RWC), reduced chlorophyll loss and lower Malondialdehyde (MDA) production in relation to wild-type plants. Moreover, transgenic seeds exhibited higher germination rates than wild-type seeds under water deficit. Overall, our results highlight the presence of transgenic Rab28 protein in nucleolar structures and point to the potential of group 5 LEA Rab28 gene as candidate to enhance stress tolerance in maize plants. Copyright © 2013 Elsevier GmbH. All rights reserved.

  6. Increased expression of the yeast multidrug resistance ABC transporter Pdr18 leads to increased ethanol tolerance and ethanol production in high gravity alcoholic fermentation

    Directory of Open Access Journals (Sweden)

    Teixeira Miguel C

    2012-07-01

    Full Text Available Abstract Background The understanding of the molecular basis of yeast tolerance to ethanol may guide the design of rational strategies to increase process performance in industrial alcoholic fermentations. A set of 21 genes encoding multidrug transporters from the ATP-Binding Cassette (ABC Superfamily and Major Facilitator Superfamily (MFS in S. cerevisiae were scrutinized for a role in ethanol stress resistance. Results A yeast multidrug resistance ABC transporter encoded by the PDR18 gene, proposed to play a role in the incorporation of ergosterol in the yeast plasma membrane, was found to confer resistance to growth inhibitory concentrations of ethanol. PDR18 expression was seen to contribute to decreased 3 H-ethanol intracellular concentrations and decreased plasma membrane permeabilization of yeast cells challenged with inhibitory ethanol concentrations. Given the increased tolerance to ethanol of cells expressing PDR18, the final concentration of ethanol produced during high gravity alcoholic fermentation by yeast cells devoid of PDR18 was lower than the final ethanol concentration produced by the corresponding parental strain. Moreover, an engineered yeast strain in which the PDR18 promoter was replaced in the genome by the stronger PDR5 promoter, leading to increased PDR18 mRNA levels during alcoholic fermentation, was able to attain a 6 % higher ethanol concentration and a 17 % higher ethanol production yield than the parental strain. The improved fermentative performance of yeast cells over-expressing PDR18 was found to correlate with their increased ethanol tolerance and ability to restrain plasma membrane permeabilization induced throughout high gravity fermentation. Conclusions PDR18 gene over-expression increases yeast ethanol tolerance and fermentation performance leading to the production of highly inhibitory concentrations of ethanol. PDR18 overexpression in industrial yeast strains appears to be a promising approach to

  7. Engineering microbes for tolerance to next-generation biofuels

    Directory of Open Access Journals (Sweden)

    Dunlop Mary J

    2011-09-01

    Full Text Available Abstract A major challenge when using microorganisms to produce bulk chemicals such as biofuels is that the production targets are often toxic to cells. Many biofuels are known to reduce cell viability through damage to the cell membrane and interference with essential physiological processes. Therefore, cells must trade off biofuel production and survival, reducing potential yields. Recently, there have been several efforts towards engineering strains for biofuel tolerance. Promising methods include engineering biofuel export systems, heat shock proteins, membrane modifications, more general stress responses, and approaches that integrate multiple tolerance strategies. In addition, in situ recovery methods and media supplements can help to ease the burden of end-product toxicity and may be used in combination with genetic approaches. Recent advances in systems and synthetic biology provide a framework for tolerance engineering. This review highlights recent targeted approaches towards improving microbial tolerance to next-generation biofuels with a particular emphasis on strategies that will improve production.

  8. Palmitoylation at Cys574 is essential for MT1-MMP to promote cell migration

    DEFF Research Database (Denmark)

    Anilkumar, Narayanapanicker; Uekita, Takamasa; Couchman, John R

    2005-01-01

    of the palmitoylated cysteine relative to LLY573, a motif that interacts with mu2 subunit of adaptor protein 2, is critical for the cell motility-promoting activity of MT1-MMP and its clathrin-mediated internalization. Taken together, palmitoylation of MT1-MMP is one of the key posttranslational modifications......MT1-MMP is a type I transmembrane proteinase that promotes cell migration and invasion. Here, we report that MT1-MMP is palmitoylated at Cys574 in the cytoplasmic domain, and this lipid modification is critical for its promotion of cell migration and clathrin-mediated internalization...... that determines MT1-MMP-dependent cell migration....

  9. Phosphatidylserine-Liposomes Promote Tolerogenic Features on Dendritic Cells in Human Type 1 Diabetes by Apoptotic Mimicry

    Directory of Open Access Journals (Sweden)

    Silvia Rodriguez-Fernandez

    2018-02-01

    Full Text Available Type 1 diabetes (T1D is a metabolic disease caused by the autoimmune destruction of insulin-producing β-cells. With its incidence increasing worldwide, to find a safe approach to permanently cease autoimmunity and allow β-cell recovery has become vital. Relying on the inherent ability of apoptotic cells to induce immunological tolerance, we demonstrated that liposomes mimicking apoptotic β-cells arrested autoimmunity to β-cells and prevented experimental T1D through tolerogenic dendritic cell (DC generation. These liposomes contained phosphatidylserine (PS—the main signal of the apoptotic cell membrane—and β-cell autoantigens. To move toward a clinical application, PS-liposomes with optimum size and composition for phagocytosis were loaded with human insulin peptides and tested on DCs from patients with T1D and control age-related subjects. PS accelerated phagocytosis of liposomes with a dynamic typical of apoptotic cell clearance, preserving DCs viability. After PS-liposomes phagocytosis, the expression pattern of molecules involved in efferocytosis, antigen presentation, immunoregulation, and activation in DCs concurred with a tolerogenic functionality, both in patients and control subjects. Furthermore, DCs exposed to PS-liposomes displayed decreased ability to stimulate autologous T cell proliferation. Moreover, transcriptional changes in DCs from patients with T1D after PS-liposomes phagocytosis pointed to an immunoregulatory prolife. Bioinformatics analysis showed 233 differentially expressed genes. Genes involved in antigen presentation were downregulated, whereas genes pertaining to tolerogenic/anti-inflammatory pathways were mostly upregulated. In conclusion, PS-liposomes phagocytosis mimics efferocytosis and leads to phenotypic and functional changes in human DCs, which are accountable for tolerance induction. The herein reported results reinforce the potential of this novel immunotherapy to re-establish immunological

  10. Transfusion of 35-day-stored red blood cells does not alter lipopolysaccharide tolerance during human endotoxemia

    NARCIS (Netherlands)

    Peters, Anna L.; van Hezel, Maike E.; Klanderman, Robert B.; Tuip-de Boer, Anita M.; Wiersinga, W. Joost; van der Spek, Anne H.; van Bruggen, Robin; de Korte, Dirk; Juffermans, Nicole P.; Vlaar, Alexander P. J.

    2017-01-01

    Transfusion-related immunomodulation (TRIM) encompasses immunosuppressive and proinflammatory effects induced by red blood cell (RBC) transfusion. Changes that occur during storage in the RBC product have been hypothesized to underlie TRIM, mediated by tolerance of toll-like receptors (TLR). We

  11. A specific immune tolerance toward offspring cells is to exist after the mother lymphocyte infusion.

    Science.gov (United States)

    Xing, Haizhou; Liu, Shiqin; Chen, Xue; Fang, Fang; Wu, Xueqiang; Zhu, Ping

    2017-04-01

    To examine immune tolerance between maternal lymphocytes and offspring tissue after a donor lymphocyte infusion. Mouse models were established by mating female BALB/c mice with male C57BL mice. Splenic lymphocytes from donors of different genetic backgrounds were labeled with carboxyfluorescein succinimidyl ester (CFSE), and 1×10 7 of the labeled cells were intravenously injected into a recipient. At 6h, 24h, 72h and 120h after the infusion, mononuclear cells in recipient spleen, liver, thymus, lymph nodes, and peripheral blood were collected. CFSE+, CFSE-, CD3+, CD8+, CD4+, CD19+, NK1.1+, CD25+, and CD127+ lymphocytes in those samples were analyzed by flow cytometry. The distribution of donor T cells, B cells, NK cells, helper T cells, cytotoxic T cells, and recipient regulatory T cells in the tissues were then analyzed. Maternal lymphocytes were more likely to survive in offspring. At 120h after infusion, the percentages of maternal cells in the offspring were 0.52±0.11% in lymph nodes, 0.97±0.04% in peripheral blood, and 0.97±0.11% in the spleen. Few donor cells, if any, were detected in these tissues at 120h after aunt to child, father to child, and unrelated allogeneic infusions were performed. The subtype proportion of donor lymphocytes changed significantly in the recipient tissues. Recipient Treg cells increased in the mother to child group, but not in the aunt to child, father to child, and unrelated allogeneic groups, suggesting a decreased cellular immune response to allogeneic cells in the mother to child group. At 120h after the infusion, no donor cells were detected in the recipient livers and thymuses of all groups, implying that donor cells were barely able to colonize in the liver and thymus. Specific immune tolerance to maternal lymphocytes exists in offspring. An infusion of maternal donor lymphocytes may produce a relatively persistent effect of adoptive immunotherapy with reduced side-effects. Copyright © 2017 Elsevier GmbH. All rights

  12. Tumor-promoting phorbol esters effect alkalinization of canine renal proximal tubular cells

    International Nuclear Information System (INIS)

    Mellas, J.; Hammerman, M.R.

    1986-01-01

    We have demonstrated the presence of specific receptors for tumor-promoting phorbol esters in the plasma membrane of the canine renal proximal tubular cell. These compounds affect proximal tubular metabolism in vitro. For example, we have shown that they inhibit gluconeogenesis in canine renal proximal tubular segments. Tumor-promoting phorbol esters have been shown to effect alkalinization of non-renal cells, by enhancing Na + -H + exchange across the plasma membrane. To determine whether the actions of tumor-promoting phorbol esters in proximal tubular segments might be mediated by a similar process, we incubated suspensions of segments from dog kidney with these compounds and measured changes in intracellular pH using [ 14 C]-5,5-dimethoxazoladine-2-4-dione (DMO) and flow dialysis. Incubation of segments with phorbol 12,13 dibutyrate, but not inactive phorbol ester, 4 γ phorbol, effected alkalinization of cells within the segments in a concentration-dependent manner. Alkalinization was dependent upon the presence of extracellular [Na + ] > intracellular [Na + ], was prevented by amiloride and was demonstrable in the presence of SITS. Our findings suggest that tumor-promoting esters stimulate the Na + -H + exchanger known to be present in the brush border membrane of the renal proximal tubular cell. It is possible that the stimulation reflects a mechanism by which phorbol esters affect metabolic processes in these cells

  13. miR-664 negatively regulates PLP2 and promotes cell proliferation and invasion in T-cell acute lymphoblastic leukaemia

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Hong; Miao, Mei-hua; Ji, Xue-qiang; Xue, Jun; Shao, Xue-jun, E-mail: xuejunshao@hotmail.com

    2015-04-03

    MicroRNAs (miRNAs) play important roles in the pathogenesis of many types of cancers by negatively regulating gene expression at posttranscriptional level. However, the role of microRNAs in leukaemia, particularly T-cell acute lymphoblastic leukaemia (T-ALL), has remained elusive. Here, we identified miR-664 and its predicted target gene PLP2 were differentially expressed in T-ALL using bioinformatics methods. In T-ALL cell lines, CCK-8 proliferation assay indicated that the cell proliferation was promoted by miR-664, while miR-664 inhibitor could significantly inhibited the proliferation. Moreover, migration and invasion assay showed that overexpression of miR-664 could significantly promoted the migration and invasion of T-ALL cells, whereas miR-664 inhibitor could reduce cell migration and invasion. luciferase assays confirmed that miR-664 directly bound to the 3'untranslated region of PLP2, and western blotting showed that miR-664 suppressed the expression of PLP2 at the protein levels. This study indicated that miR-664 negatively regulates PLP2 and promotes proliferation and invasion of T-ALL cell lines. Thus, miR-664 may represent a potential therapeutic target for T-ALL intervention. - Highlights: • miR-664 mimics promote the proliferation and invasion of T-ALL cells. • miR-664 inhibitors inhibit the proliferation and invasion of T-ALL cells. • miR-664 targets 3′ UTR of PLP2 in T-ALL cells. • miR-664 negatively regulates PLP2 in T-ALL cells.

  14. PDGFBB promotes PDGFR{alpha}-positive cell migration into artificial bone in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Shigeyuki [Department of Dentistry and Oral Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Center for Human Metabolomic Systems Biology, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Iwasaki, Ryotaro; Kawana, Hiromasa [Department of Dentistry and Oral Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Miyauchi, Yoshiteru [Center for Human Metabolomic Systems Biology, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Department of Integrated Bone Metabolism and Immunology, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Hoshi, Hiroko; Miyamoto, Hiroya; Mori, Tomoaki [Center for Human Metabolomic Systems Biology, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Kanagawa, Hiroya [Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Katsuyama, Eri; Fujie, Atsuhiro [Center for Human Metabolomic Systems Biology, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Hao, Wu [Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); and others

    2012-05-18

    Highlights: Black-Right-Pointing-Pointer We examined effects of PDGFBB in PDGFR{alpha} positive cell migration in artificial bones. Black-Right-Pointing-Pointer PDGFBB was not expressed in osteoblastic cells but was expressed in peripheral blood cells. Black-Right-Pointing-Pointer PDGFBB promoted PDGFR{alpha} positive cell migration into artificial bones but not osteoblast proliferation. Black-Right-Pointing-Pointer PDGFBB did not inhibit osteoblastogenesis. -- Abstract: Bone defects caused by traumatic bone loss or tumor dissection are now treated with auto- or allo-bone graft, and also occasionally by artificial bone transplantation, particularly in the case of large bone defects. However, artificial bones often exhibit poor affinity to host bones followed by bony union failure. Thus therapies combining artificial bones with growth factors have been sought. Here we report that platelet derived growth factor bb (PDGFBB) promotes a significant increase in migration of PDGF receptor {alpha} (PDGFR{alpha})-positive mesenchymal stem cells/pre-osteoblastic cells into artificial bone in vivo. Growth factors such as transforming growth factor beta (TGF{beta}) and hepatocyte growth factor (HGF) reportedly inhibit osteoblast differentiation; however, PDGFBB did not exhibit such inhibitory effects and in fact stimulated osteoblast differentiation in vitro, suggesting that combining artificial bones with PDGFBB treatment could promote host cell migration into artificial bones without inhibiting osteoblastogenesis.

  15. Cell-cell adhesion mediated by binding of membrane-anchored transforming growth factor α to epidermal growth factor receptors promotes cell proliferation

    International Nuclear Information System (INIS)

    Anklesaria, P.; Greenberger, J.S.; Teixido, J.; Laiho, M.; Massague, J.; Pierce, J.H.

    1990-01-01

    The precursor for transforming growth factor α, pro-TGF-α, is a cell surface glycoprotein that can establish contact with epidermal growth factor (EGF) receptors on adjacent cells. To examine whether the pro-TGF-α/EGF receptor pair can simultaneously mediate cell adhesion and promote cell proliferation, the authors have expressed pro-TGF-α in a bone marrow stromal cell line labeled with [ 35 S] cysteine. Expression of pro-TGF-α allows these cells to support long-term attachment of an EGF/interleukin-3-dependent hematopoietic progenitor cell line that expresses EGF receptors but is unable to adhere to normal stroma. This interaction is inhibited by soluble EGF receptor ligands. Further, the hematopoietic progenitor cells replicate their DNA while they are attached to the stromal cell layer and become foci of sustained cell proliferation. Thus, pro-TGF-α and the EGF receptor can function as mediators of intercellular adhesion and this interaction may promote a mitogenic response. They propose the term juxtacrine to designate this form of stimulation between adjacent cells

  16. miR-367 promotes proliferation and invasion of hepatocellular carcinoma cells by negatively regulating PTEN

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Xiangrui, E-mail: mengxiangruibb2008@163.com [Oncology Department, The First Affiliated Hospital of Zhengzhou University, Zhengzhou (China); Lu, Peng [Gastrointestinal Surgery Department, People' s Hospital of Zhengzhou, Zhengzhou (China); Fan, Qingxia [Oncology Department, The First Affiliated Hospital of Zhengzhou University, Zhengzhou (China)

    2016-01-29

    MicroRNAs play important roles in the carcinogenesis of many types of cancers by inhibiting gene expression at posttranscriptional level. However, the roles of microRNAs in hepatocellular carcinoma, are still unclear. Here, we identified that miR-367 promotes hepatocellular carcinoma (HCC) cell proliferation by negatively regulates its target gene PTEN. The expression of miR-367 and PTEN are significantly inverse correlated in 35 HCC patients. In HCC cell line, CCK-8 proliferation assay indicated that the cell proliferation was promoted by miR-367, while miR-367 inhibitor significantly inhibited the cell proliferation. Transwell assay showed that miR-367 mimics significantly promoted the migration and invasion of HCC cells, whereas miR-367 inhibitors significantly reduced cell migration and invasion. Luciferase assays confirmed that miR-367 directly bound to the 3'untranslated region of PTEN, and western blotting showed that miR-367 suppressed the expression of PTEN at the protein levels. This study indicated that miR-367 negatively regulates PTEN and promotes proliferation and invasion of HCC cells. Thus, miR-367 may represent a potential therapeutic target for HCC intervention. - Highlights: • miR-367 mimics promote the proliferation and invasion of HCC cells. • miR-367 inhibitors inhibit the proliferation and invasion of HCC cells. • miR-367 targets 3′UTR of PTEN in HCC cells. • miR-367 negatively regulates PTEN in HCC cells.

  17. Role of Melatonin in Cell-Wall Disassembly and Chilling Tolerance in Cold-Stored Peach Fruit.

    Science.gov (United States)

    Cao, Shifeng; Bian, Kun; Shi, Liyu; Chung, Hsiao-Hang; Chen, Wei; Yang, Zhenfeng

    2018-06-06

    Melatonin reportedly increases chilling tolerance in postharvest peach fruit during cold storage, but information on its effects on cell-wall disassembly in chilling-injured peaches is limited. In this study, we investigated the role of cell-wall depolymerization in chilling-tolerance induction in melatonin-treated peaches. Treatment with 100 μM melatonin alleviated chilling symptoms (mealiness) characterized by a decrease in fruit firmness and increase in juice extractability in treated peaches during storage. The loss of neutral sugars, such as arabinose and galactose, in both the 1,2-cyclohexylenedinitrilotetraacetic acid (CDTA)- and Na 2 CO 3 -soluble fractions was observed at 7 days in treated peaches, but the contents increased after 28 days of storage. Atomic-force-microscopy (AFM) analysis revealed that the polysaccharide widths in the CDTA- and Na 2 CO 3 -soluble fractions in the treated fruit were mainly distributed in a shorter range, as compared with those in the control fruit. In addition, the expression profiles of a series of cell-wall-related genes showed that melatonin treatment maintained the balance between transcripts of PpPME and PpPG, which accompany the up-regulation of several other genes involved in cell-wall disassembly. Taken together, our results suggested that the reduced mealiness by melatonin was probably associated with its positive regulation of numerous cell-wall-modifying enzymes and proteins; thus, the depolymerization of the cell-wall polysaccharides in the peaches treated with melatonin was maintained, and the treated fruit could soften gradually during cold storage.

  18. Promotion or suppression of experimental metastasis of B16 melanoma cells after oral administration of lapachol

    International Nuclear Information System (INIS)

    Maeda, Masayo; Murakami, Manabu; Takegami, Tsutomu; Ota, Takahide

    2008-01-01

    Lapachol [2-hydroxy-3-(3-methyl-2-butenyl)-1,4-naphthoquinone] is a vitamin K antagonist with antitumor activity. The effect of lapachol on the experimental metastasis of murine B16BL6 melanoma cells was examined. A single oral administration of a high toxic dose of lapachol (80-100 mg/kg) 6 h before iv injection of tumor cells drastically promoted metastasis. This promotion of metastasis was also observed in T-cell-deficient mice and NK-suppressed mice. In vitro treatment of B16BL6 cells with lapachol promoted metastasis only slightly, indicating that lapachol promotes metastasis primarily by affecting host factors other than T cells and NK cells. A single oral administration of warfarin, the most commonly used vitamin K antagonist, 6 h before iv injection of tumor cells also drastically promoted the metastasis of B16BL6 cells. The promotion of metastasis by lapachol and warfarin was almost completely suppressed by preadministration of vitamin K3, indicating that the promotion of metastasis by lapachol was derived from vitamin K antagonism. Six hours after oral administration of lapachol or warfarin, the protein C level was reduced maximally, without elongation of prothrombin time. These observations suggest that a high toxic dose of lapachol promotes metastasis by inducing a hypercoagulable state as a result of vitamin K-dependent pathway inhibition. On the other hand, serial oral administration of low non-toxic doses of lapachol (5-20 mg/kg) weakly but significantly suppressed metastasis by an unknown mechanism, suggesting the possible use of lapachol as an anti-metastatic agent

  19. The fatty acid profile of rainbow trout liver cells modulates their tolerance to methylmercury and cadmium

    International Nuclear Information System (INIS)

    Ferain, Aline; Bonnineau, Chloé; Neefs, Ineke; Rees, Jean François; Larondelle, Yvan; Schamphelaere, Karel A.C.De; Debier, Cathy

    2016-01-01

    protected the RTL-W1 cells against both methylmercury and cadmium; (iv) DHA enrichment significantly protected the cells against cadmium but not methylmercury; (v) AA and LA enrichment had no impact on the cell tolerance to both methylmercury and cadmium; (vi) the abundance of 20:3n-6, a metabolite of the n-6 biotransformation pathway, in phospholipids was negatively correlated to the cell tolerance to both methylmercury and cadmium. Overall, our results highlighted the importance of the fatty acid supply on the tolerance of fish liver cells to methylmercury and cadmium.

  20. The fatty acid profile of rainbow trout liver cells modulates their tolerance to methylmercury and cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Ferain, Aline, E-mail: aline.ferain@uclouvain.be [Institute of Life Sciences, Université catholique de Louvain, Place Croix du Sud 2/L7.05.08, B-1348 Louvain-la-Neuve (Belgium); Bonnineau, Chloé [Institute of Life Sciences, Université catholique de Louvain, Place Croix du Sud 2/L7.05.08, B-1348 Louvain-la-Neuve (Belgium); Irstea, UR MALY, Centre de Lyon-Villeurbanne, rue de la Doua 5/32108, F-69616 Villeurbanne (France); Neefs, Ineke; Rees, Jean François; Larondelle, Yvan [Institute of Life Sciences, Université catholique de Louvain, Place Croix du Sud 2/L7.05.08, B-1348 Louvain-la-Neuve (Belgium); Schamphelaere, Karel A.C.De [Laboratory of Environmental Toxicology and Aquatic Ecology, Environmental Toxicology Unit, Ghent University, J. Plateaustraat 22, B-9000 Ghent (Belgium); Debier, Cathy [Institute of Life Sciences, Université catholique de Louvain, Place Croix du Sud 2/L7.05.08, B-1348 Louvain-la-Neuve (Belgium)

    2016-08-15

    protected the RTL-W1 cells against both methylmercury and cadmium; (iv) DHA enrichment significantly protected the cells against cadmium but not methylmercury; (v) AA and LA enrichment had no impact on the cell tolerance to both methylmercury and cadmium; (vi) the abundance of 20:3n-6, a metabolite of the n-6 biotransformation pathway, in phospholipids was negatively correlated to the cell tolerance to both methylmercury and cadmium. Overall, our results highlighted the importance of the fatty acid supply on the tolerance of fish liver cells to methylmercury and cadmium.

  1. Senescence from glioma stem cell differentiation promotes tumor growth

    International Nuclear Information System (INIS)

    Ouchi, Rie; Okabe, Sachiko; Migita, Toshiro; Nakano, Ichiro; Seimiya, Hiroyuki

    2016-01-01

    Glioblastoma (GBM) is a lethal brain tumor composed of heterogeneous cellular populations including glioma stem cells (GSCs) and differentiated non-stem glioma cells (NSGCs). While GSCs are involved in tumor initiation and propagation, NSGCs' role remains elusive. Here, we demonstrate that NSGCs undergo senescence and secrete pro-angiogenic proteins, boosting the GSC-derived tumor formation in vivo. We used a GSC model that maintains stemness in neurospheres, but loses the stemness and differentiates into NSGCs upon serum stimulation. These NSGCs downregulated telomerase, shortened telomeres, and eventually became senescent. The senescent NSGCs released pro-angiogenic proteins, including vascular endothelial growth factors and senescence-associated interleukins, such as IL-6 and IL-8. Conditioned medium from senescent NSGCs promoted proliferation of brain microvascular endothelial cells, and mixed implantation of GSCs and senescent NSGCs into mice enhanced the tumorigenic potential of GSCs. The senescent NSGCs seem to be clinically relevant, because both clinical samples and xenografts of GBM contained tumor cells that expressed the senescence markers. Our data suggest that senescent NSGCs promote malignant progression of GBM in part via paracrine effects of the secreted proteins. - Highlights: • Non-stem glioma cells (NSGCs) lose telomerase and eventually become senescent. • Senescent NSGCs secrete pro-angiogenic proteins, such as VEGFs, IL-6, and IL-8. • Senescent NSGCs enhance the growth of brain microvascular endothelial cells. • Senescent NSGCs enhance the tumorigenic potential of glioma stem cells in vivo.

  2. Senescence from glioma stem cell differentiation promotes tumor growth

    Energy Technology Data Exchange (ETDEWEB)

    Ouchi, Rie [Division of Molecular Biotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo 135-8550 (Japan); Laboratory of Molecular Target Therapy of Cancer, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 3-8-31 Ariake, Koto-ku, Tokyo 135-8550 (Japan); Okabe, Sachiko; Migita, Toshiro [Division of Molecular Biotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo 135-8550 (Japan); Nakano, Ichiro [Department of Neurosurgery, Comprehensive Cancer Center, University of Alabama at Birmingham, 1824 6th Avenue South, Birmingham, AL 35233 (United States); Seimiya, Hiroyuki, E-mail: hseimiya@jfcr.or.jp [Division of Molecular Biotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo 135-8550 (Japan); Laboratory of Molecular Target Therapy of Cancer, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 3-8-31 Ariake, Koto-ku, Tokyo 135-8550 (Japan)

    2016-02-05

    Glioblastoma (GBM) is a lethal brain tumor composed of heterogeneous cellular populations including glioma stem cells (GSCs) and differentiated non-stem glioma cells (NSGCs). While GSCs are involved in tumor initiation and propagation, NSGCs' role remains elusive. Here, we demonstrate that NSGCs undergo senescence and secrete pro-angiogenic proteins, boosting the GSC-derived tumor formation in vivo. We used a GSC model that maintains stemness in neurospheres, but loses the stemness and differentiates into NSGCs upon serum stimulation. These NSGCs downregulated telomerase, shortened telomeres, and eventually became senescent. The senescent NSGCs released pro-angiogenic proteins, including vascular endothelial growth factors and senescence-associated interleukins, such as IL-6 and IL-8. Conditioned medium from senescent NSGCs promoted proliferation of brain microvascular endothelial cells, and mixed implantation of GSCs and senescent NSGCs into mice enhanced the tumorigenic potential of GSCs. The senescent NSGCs seem to be clinically relevant, because both clinical samples and xenografts of GBM contained tumor cells that expressed the senescence markers. Our data suggest that senescent NSGCs promote malignant progression of GBM in part via paracrine effects of the secreted proteins. - Highlights: • Non-stem glioma cells (NSGCs) lose telomerase and eventually become senescent. • Senescent NSGCs secrete pro-angiogenic proteins, such as VEGFs, IL-6, and IL-8. • Senescent NSGCs enhance the growth of brain microvascular endothelial cells. • Senescent NSGCs enhance the tumorigenic potential of glioma stem cells in vivo.

  3. Induction of bacterial lipoprotein tolerance is associated with suppression of toll-like receptor 2 expression.

    LENUS (Irish Health Repository)

    Wang, Jiang Huai

    2012-02-03

    Tolerance to bacterial cell wall components including lipopolysaccharide (LPS) may represent an essential regulatory mechanism during bacterial infection. Two members of the Toll-like receptor (TLR) family, TLR2 and TLR4, recognize the specific pattern of bacterial cell wall components. TLR4 has been found to be responsible for LPS tolerance. However, the role of TLR2 in bacterial lipoprotein (BLP) tolerance and LPS tolerance is unclear. Pretreatment of human THP-1 monocytic cells with a synthetic bacterial lipopeptide induced tolerance to a second BLP challenge with diminished tumor necrosis factor-alpha and interleukin-6 production, termed BLP tolerance. Furthermore, BLP-tolerized THP-1 cells no longer responded to LPS stimulation, indicating a cross-tolerance to LPS. Induction of BLP tolerance was CD14-independent, as THP-1 cells that lack membrane-bound CD14 developed tolerance both in serum-free conditions and in the presence of a specific CD14 blocking monoclonal antibody (MEM-18). Pre-exposure of THP-1 cells to BLP suppressed mitogen-activated protein kinase phosphorylation and nuclear factor-kappaB activation in response to subsequent BLP and LPS stimulation, which is comparable with that found in LPS-tolerized cells, indicating that BLP tolerance and LPS tolerance may share similar intracellular pathways. However, BLP strongly enhanced TLR2 expression in non-tolerized THP-1 cells, whereas LPS stimulation had no effect. Furthermore, a specific TLR2 blocking monoclonal antibody (2392) attenuated BLP-induced, but not LPS-induced, tumor necrosis factor-alpha and interleukin-6 production, indicating BLP rather than LPS as a ligand for TLR2 engagement and activation. More importantly, pretreatment of THP-1 cells with BLP strongly inhibited TLR2 activation in response to subsequent BLP stimulation. In contrast, LPS tolerance did not prevent BLP-induced TLR2 overexpression. These results demonstrate that BLP tolerance develops through down-regulation of TLR2

  4. The Role of Helicobacter pylori Seropositivity in Insulin Sensitivity, Beta Cell Function, and Abnormal Glucose Tolerance

    Directory of Open Access Journals (Sweden)

    Lou Rose Malamug

    2014-01-01

    Full Text Available Infection, for example, Helicobacter pylori (H. pylori, has been thought to play a role in the pathogenesis of type 2 diabetes mellitus (T2DM. Our aim was to determine the role of H. pylori infection in glucose metabolism in an American cohort. We examined data from 4,136 non-Hispanic white (NHW, non-Hispanic black (NHB, and Mexican Americans (MA aged 18 and over from the NHANES 1999-2000 cohort. We calculated the odds ratios for states of glucose tolerance based on the H. pylori status. We calculated and compared homeostatic model assessment insulin resistance (HOMA-IR and beta cell function (HOMA-B in subjects without diabetes based on the H. pylori status. The results were adjusted for age, body mass index (BMI, poverty index, education, alcohol consumption, tobacco use, and physical activity. The H. pylori status was not a risk factor for abnormal glucose tolerance. After adjustment for age and BMI and also adjustment for all covariates, no difference was found in either HOMA-IR or HOMA-B in all ethnic and gender groups except for a marginally significant difference in HOMA-IR in NHB females. H. pylori infection was not a risk factor for abnormal glucose tolerance, nor plays a major role in insulin resistance or beta cell dysfunction.

  5. HCG-Activated Human Peripheral Blood Mononuclear Cells (PBMC Promote Trophoblast Cell Invasion.

    Directory of Open Access Journals (Sweden)

    Nan Yu

    Full Text Available Successful embryo implantation and placentation depend on appropriate trophoblast invasion into the maternal endometrial stroma. Human chorionic gonadotropin (hCG is one of the earliest embryo-derived secreted signals in the peripheral blood mononuclear cells (PBMC that abundantly expresses hCG receptors. The aims of this study were to estimate the effect of human embryo-secreted hCG on PBMC function and investigate the role and underlying mechanisms of activated PBMC in trophoblast invasion. Blood samples were collected from women undergoing benign gynecological surgery during the mid-secretory phase. PBMC were isolated and stimulated with or without hCG for 0 or 24 h. Interleukin-1β (IL-1β and leukemia inhibitory factor (LIF expressions in PBMC were detected by enzyme-linked immunosorbent assay and real-time polymerase chain reaction (PCR. The JAR cell line served as a model for trophoblast cells and was divided into four groups: control, hCG only, PBMC only, and PBMC with hCG. JAR cell invasive and proliferative abilities were detected by trans-well and CCK8 assays and matrix metalloproteinase (MMP-2 (MMP-2, MMP-9, vascular endothelial growth factor (VEGF, tissue inhibitor of metalloproteinase (TIMP-1, and TIMP-2 expressions in JAR cells were detected by western blotting and real-time PCR analysis. We found that hCG can remarkably promote IL-1β and LIF promotion in PBMC after 24-h culture. PBMC activated by hCG significantly increased the number of invasive JAR cells in an invasion assay without affecting proliferation, and hCG-activated PBMC significantly increased MMP-2, MMP-9, and VEGF and decreased TIMP-1 and TIMP-2 expressions in JAR cells in a dose-dependent manner. This study demonstrated that hCG stimulates cytokine secretion in human PBMC and could stimulate trophoblast invasion.

  6. Enhanced pathway efficiency of Saccharomyces cerevisiae by introducing thermo-tolerant devices.

    Science.gov (United States)

    Liu, Yueqin; Zhang, Genli; Sun, Huan; Sun, Xiangying; Jiang, Nisi; Rasool, Aamir; Lin, Zhanglin; Li, Chun

    2014-10-01

    In this study, thermo-tolerant devices consisting of heat shock genes from thermophiles were designed and introduced into Saccharomyces cerevisiae for improving its thermo-tolerance. Among ten engineered thermo-tolerant yeasts, T.te-TTE2469, T.te-GroS2 and T.te-IbpA displayed over 25% increased cell density and 1.5-4-fold cell viability compared with the control. Physiological characteristics of thermo-tolerant strains revealed that better cell wall integrity, higher trehalose content and enhanced metabolic energy were preserved by thermo-tolerant devices. Engineered thermo-tolerant strain was used to investigate the impact of thermo-tolerant device on pathway efficiency by introducing β-amyrin synthesis pathway, showed 28.1% increased β-amyrin titer, 28-35°C broadened growth temperature range and 72h shortened fermentation period. The results indicated that implanting heat shock proteins from thermophiles to S. cerevisiae would be an efficient approach to improve its thermo-tolerance. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Oral Tolerance: Therapeutic Implications for Autoimmune Diseases

    Directory of Open Access Journals (Sweden)

    Ana M. C. Faria

    2006-01-01

    Full Text Available Oral tolerance is classically defined as the suppression of immune responses to antigens (Ag that have been administered previously by the oral route. Multiple mechanisms of tolerance are induced by oral Ag. Low doses favor active suppression, whereas higher doses favor clonal anergy/deletion. Oral Ag induces Th2 (IL-4/IL-10 and Th3 (TGF-β regulatory T cells (Tregs plus CD4+CD25+ regulatory cells and LAP+T cells. Induction of oral tolerance is enhanced by IL-4, IL-10, anti-IL-12, TGF-β, cholera toxin B subunit (CTB, Flt-3 ligand, anti-CD40 ligand and continuous feeding of Ag. In addition to oral tolerance, nasal tolerance has also been shown to be effective in suppressing inflammatory conditions with the advantage of a lower dose requirement. Oral and nasal tolerance suppress several animal models of autoimmune diseases including experimental allergic encephalomyelitis (EAE, uveitis, thyroiditis, myasthenia, arthritis and diabetes in the nonobese diabetic (NOD mouse, plus non-autoimmune diseases such as asthma, atherosclerosis, colitis and stroke. Oral tolerance has been tested in human autoimmune diseases including MS, arthritis, uveitis and diabetes and in allergy, contact sensitivity to DNCB, nickel allergy. Positive results have been observed in phase II trials and new trials for arthritis, MS and diabetes are underway. Mucosal tolerance is an attractive approach for treatment of autoimmune and inflammatory diseases because of lack of toxicity, ease of administration over time and Ag-specific mechanism of action. The successful application of oral tolerance for the treatment of human diseases will depend on dose, developing immune markers to assess immunologic effects, route (nasal versus oral, formulation, mucosal adjuvants, combination therapy and early therapy.

  8. Osmotic stress tolerance in semi-terrestrial tardigrades

    DEFF Research Database (Denmark)

    Heidemann, Nanna W T; Smith, Daniel K.; Hygum, Thomas L.

    2016-01-01

    Little is known about ionic and osmotic stress tolerance in tardigrades. Here, we examine salt stress tolerance in Ramazzottius oberhaeuseri and Echiniscus testudo from Nivå (Denmark) and address whether limno-terrestrial tardigrades can enter a state of quiescence (osmobiosis) in the face of high......-ionic osmolytes as compared to NaCl. Ramazzottius oberhaeuseri furthermore readily regained activity following gradual increases in non-ionic osmolytes and NaCl of up to 2434 ± 28 and 1905 ± 3 mOsm kg−1, respectively, showing that short-term acclimation promoted salt stress tolerance. Our results suggest...... that the limno-terrestrial R. oberhaeuseri enters a state of quiescence in the face of high external osmotic pressure and that it, in this state, is highly tolerant of ionic and osmotic stress....

  9. Adoptive transfer of transplantation tolerance in the H-2 compatible mouse system CBA/C3H

    International Nuclear Information System (INIS)

    Siegl, E.; Brock, J.; Schulze, H.A.

    1985-01-01

    Transfer of neonatally induced tolerance in the H-2 compatible CBA/C3H strain combination is possible with different efficiency by injection of adherent and non-adherent spleen cells, unseparated spleen cells and lymph node cells from C3H-tolerant CBA mice into sublethal irradiated CBA mice. The most efficient cell populations are adherent spleen cells and lymph node cells. Successfull transfer of transplantation tolerance is not possible to non-irradiated mice. The adherent fraction of spleen cells and lymph node cells contains a suppressor cell population responsible for transplantation tolerance against non-H-2 antigens. The induced transplantation tolerance is not due to a chimeric state of C3H-tolerant CBA mice. (author)

  10. Co-culture with Sertoli cells promotes proliferation and migration of umbilical cord mesenchymal stem cells

    International Nuclear Information System (INIS)

    Zhang, Fenxi; Hong, Yan; Liang, Wenmei; Ren, Tongming; Jing, Suhua; Lin, Juntang

    2012-01-01

    Highlights: ► Co-culture of Sertoli cells (SCs) with human umbilical cord mesenchymal stem cells (UCMSCs). ► Presence of SCs dramatically increased proliferation and migration of UCMSCs. ► Presence of SCs stimulated expression of Mdm2, Akt, CDC2, Cyclin D, CXCR4, MAPKs. -- Abstract: Human umbilical cord mesenchymal stem cells (hUCMSCs) have been recently used in transplant therapy. The proliferation and migration of MSCs are the determinants of the efficiency of MSC transplant therapy. Sertoli cells are a kind of “nurse” cells that support the development of sperm cells. Recent studies show that Sertoli cells promote proliferation of endothelial cells and neural stem cells in co-culture. We hypothesized that co-culture of UCMSCs with Sertoli cells may also promote proliferation and migration of UCMSCs. To examine this hypothesis, we isolated UCMSCs from human cords and Sertoli cells from mouse testes, and co-cultured them using a Transwell system. We found that UCMSCs exhibited strong proliferation ability and potential to differentiate to other cell lineages such as osteocytes and adipocytes. The presence of Sertoli cells in co-culture significantly enhanced the proliferation and migration potential of UCMSCs (P < 0.01). Moreover, these phenotypic changes were accompanied with upregulation of multiple genes involved in cell proliferation and migration including phospho-Akt, Mdm2, phospho-CDC2, Cyclin D1, Cyclin D3 as well as CXCR4, phospho-p44 MAPK and phospho-p38 MAPK. These findings indicate that Sertoli cells boost UCMSC proliferation and migration potential.

  11. Co-culture with Sertoli cells promotes proliferation and migration of umbilical cord mesenchymal stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Fenxi, E-mail: fxzhang0824@gmail.com [Department of Anatomy, Sanquan College, Xinxiang Medical University, Henan 453003, People' s Republic of China (China); Hong, Yan; Liang, Wenmei [Department of Histology and Embryology, Guiyang Medical University, Guizhou 550004, People' s Republic of China (China); Ren, Tongming [Department of Anatomy, Sanquan College, Xinxiang Medical University, Henan 453003, People' s Republic of China (China); Jing, Suhua [ICU Center, The Third Hospital of Xinxiang Medical University, Henan 453003, People' s Republic of China (China); Lin, Juntang [Stem Cell Center, Xinxiang Medical University, Henan 453003, People' s Republic of China (China)

    2012-10-12

    Highlights: Black-Right-Pointing-Pointer Co-culture of Sertoli cells (SCs) with human umbilical cord mesenchymal stem cells (UCMSCs). Black-Right-Pointing-Pointer Presence of SCs dramatically increased proliferation and migration of UCMSCs. Black-Right-Pointing-Pointer Presence of SCs stimulated expression of Mdm2, Akt, CDC2, Cyclin D, CXCR4, MAPKs. -- Abstract: Human umbilical cord mesenchymal stem cells (hUCMSCs) have been recently used in transplant therapy. The proliferation and migration of MSCs are the determinants of the efficiency of MSC transplant therapy. Sertoli cells are a kind of 'nurse' cells that support the development of sperm cells. Recent studies show that Sertoli cells promote proliferation of endothelial cells and neural stem cells in co-culture. We hypothesized that co-culture of UCMSCs with Sertoli cells may also promote proliferation and migration of UCMSCs. To examine this hypothesis, we isolated UCMSCs from human cords and Sertoli cells from mouse testes, and co-cultured them using a Transwell system. We found that UCMSCs exhibited strong proliferation ability and potential to differentiate to other cell lineages such as osteocytes and adipocytes. The presence of Sertoli cells in co-culture significantly enhanced the proliferation and migration potential of UCMSCs (P < 0.01). Moreover, these phenotypic changes were accompanied with upregulation of multiple genes involved in cell proliferation and migration including phospho-Akt, Mdm2, phospho-CDC2, Cyclin D1, Cyclin D3 as well as CXCR4, phospho-p44 MAPK and phospho-p38 MAPK. These findings indicate that Sertoli cells boost UCMSC proliferation and migration potential.

  12. The Cellular and Molecular Mechanisms of Immuno-suppression by Human Type 1 Regulatory T cells

    Directory of Open Access Journals (Sweden)

    Silvia eGregori

    2012-02-01

    Full Text Available The immuno-regulatory mechanisms of IL-10-producing type 1 regulatory T (Tr1 cells have been widely studied over the years. However, several recent discoveries have shed new light on the cellular and molecular mechanisms that human Tr1 cells use to control immune responses and induce tolerance. In this review we outline the well-known and newly discovered regulatory properties of human Tr1 cells and provide an in-depth comparison of the known suppressor mechanisms of Tr1 cells with FOXP3+ Treg. We also highlight the role that Tr1 cells play in promoting and maintaining tolerance in autoimmunity, allergy, and transplantation.

  13. Exogenous fatty acid binding protein 4 promotes human prostate cancer cell progression.

    Science.gov (United States)

    Uehara, Hisanori; Takahashi, Tetsuyuki; Oha, Mina; Ogawa, Hirohisa; Izumi, Keisuke

    2014-12-01

    Epidemiologic studies have found that obesity is associated with malignant grade and mortality in prostate cancer. Several adipokines have been implicated as putative mediating factors between obesity and prostate cancer. Fatty acid binding protein 4 (FABP4), a member of the cytoplasmic fatty acid binding protein multigene family, was recently identified as a novel adipokine. Although FABP4 is released from adipocytes and mean circulating concentrations of FABP4 are linked with obesity, effects of exogenous FABP4 on prostate cancer progression are unclear. In this study, we examined the effects of exogenous FABP4 on human prostate cancer cell progression. FABP4 treatment promoted serum-induced prostate cancer cell invasion in vitro. Furthermore, oleic acid promoted prostate cancer cell invasion only if FABP4 was present in the medium. These promoting effects were reduced by FABP4 inhibitor, which inhibits FABP4 binding to fatty acids. Immunostaining for FABP4 showed that exogenous FABP4 was taken up into DU145 cells in three-dimensional culture. In mice, treatment with FABP4 inhibitor reduced the subcutaneous growth and lung metastasis of prostate cancer cells. Immunohistochemical analysis showed that the number of apoptotic cells, positive for cleaved caspase-3 and cleaved PARP, was increased in subcutaneous tumors of FABP4 inhibitor-treated mice, as compared with control mice. These results suggest that exogenous FABP4 might promote human prostate cancer cell progression by binding with fatty acids. Additionally, exogenous FABP4 activated the PI3K/Akt pathway, independently of binding to fatty acids. Thus, FABP4 might be a key molecule to understand the mechanisms underlying the obesity-prostate cancer progression link. © 2014 UICC.

  14. Advanced glycation end products promote ChREBP expression and cell proliferation in liver cancer cells by increasing reactive oxygen species.

    Science.gov (United States)

    Chen, Hanbei; Li, Yakui; Zhu, Yemin; Wu, Lifang; Meng, Jian; Lin, Ning; Yang, Dianqiang; Li, Minle; Ding, WenJin; Tong, Xuemei; Su, Qing

    2017-08-01

    The aim of the study was to elucidate the mechanism by which advanced glycation end products (AGEs) promote cell proliferation in liver cancer cells.We treated liver cancer HepG2 cells with 200 mg/L AGEs or bovine serum albumin (BSA) and assayed for cell viability, cell cycle, and apoptosis. We performed real-time PCR and Western blot analysis for RNA and protein levels of carbohydrate responsive element-binding protein (ChREBP) in AGEs- or BSA-treated HepG2 cells. We analyzed the level of reactive oxygen species (ROS) in HepG2 cells treated with AGEs or BSA.We found that increased S-phase cell percentage and decreased apoptosis contributed to AGEs-induced liver cancer cell proliferation. Real-time PCR and Western blot analysis showed that AGEs stimulated RNA and protein levels of ChREBP, a transcription factor promoting glycolysis and maintaining cell proliferation in liver cancer cells. Intriguingly, the level of ROS was higher in AGEs-treated liver cancer cells. Treating liver cancer cells with antioxidant N-acetyl cystein (NAC) partly blocked AGEs-induced ChREBP expression and cell proliferation.Our results suggest that the AGEs-ROS-ChREBP pathway plays a critical role in promoting ChREBP expression and liver cancer cell proliferation.

  15. TGF-β promotes glioma cell growth via activating Nodal expression through Smad and ERK1/2 pathways

    International Nuclear Information System (INIS)

    Sun, Jing; Liu, Su-zhi; Lin, Yan; Cao, Xiao-pan; Liu, Jia-ming

    2014-01-01

    Highlights: •TGF-β promoted Nodal expression in glioma cells. •TGF-β promoted Nodal expression via activating Smad and ERK1/2 pathways. •TGF-β promotes glioma cell growth via activating Nodal expression. -- Abstract: While there were certain studies focusing on the mechanism of TGF-β promoting the growth of glioma cells, the present work revealed another novel mechanism that TGF-β may promote glioma cell growth via enhancing Nodal expression. Our results showed that Nodal expression was significantly upregulated in glioma cells when TGF-β was added, whereas the TGF-β-induced Nodal expression was evidently inhibited by transfection Smad2 or Smad3 siRNAs, and the suppression was especially significant when the Smad3 was downregulated. Another, the attenuation of TGF-β-induced Nodal expression was observed with blockade of the ERK1/2 pathway also. Further detection of the proliferation, apoptosis, and invasion of glioma cells indicated that Nodal overexpression promoted the proliferation and invasion of tumor cells and inhibited their apoptosis, resembling the effect of TGF-β addition. Downregulation of Nodal expression via transfection Nodal-specific siRNA in the presence of TGF-β weakened the promoting effect of the latter on glioma cells growth, and transfecting Nodal siRNA alone in the absence of exogenous TGF-β more profoundly inhibited the growth of glioma cells. These results demonstrated that while both TGF-β and Nodal promoted glioma cells growth, the former might exert such effect by enhancing Nodal expression, which may form a new target for glioma therapy

  16. Three-dimensional piezoelectric fibrous scaffolds selectively promote mesenchymal stem cell differentiation.

    Science.gov (United States)

    Damaraju, Sita M; Shen, Yueyang; Elele, Ezinwa; Khusid, Boris; Eshghinejad, Ahmad; Li, Jiangyu; Jaffe, Michael; Arinzeh, Treena Livingston

    2017-12-01

    The discovery of electric fields in biological tissues has led to efforts in developing technologies utilizing electrical stimulation for therapeutic applications. Native tissues, such as cartilage and bone, exhibit piezoelectric behavior, wherein electrical activity can be generated due to mechanical deformation. Yet, the use of piezoelectric materials have largely been unexplored as a potential strategy in tissue engineering, wherein a piezoelectric biomaterial acts as a scaffold to promote cell behavior and the formation of large tissues. Here we show, for the first time, that piezoelectric materials can be fabricated into flexible, three-dimensional fibrous scaffolds and can be used to stimulate human mesenchymal stem cell differentiation and corresponding extracellular matrix/tissue formation in physiological loading conditions. Piezoelectric scaffolds that exhibit low voltage output, or streaming potential, promoted chondrogenic differentiation and piezoelectric scaffolds with a high voltage output promoted osteogenic differentiation. Electromechanical stimulus promoted greater differentiation than mechanical loading alone. Results demonstrate the additive effect of electromechanical stimulus on stem cell differentiation, which is an important design consideration for tissue engineering scaffolds. Piezoelectric, smart materials are attractive as scaffolds for regenerative medicine strategies due to their inherent electrical properties without the need for external power sources for electrical stimulation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Expression of human cationic trypsinogen (PRSS1) in murine acinar cells promotes pancreatitis and apoptotic cell death

    Science.gov (United States)

    Athwal, T; Huang, W; Mukherjee, R; Latawiec, D; Chvanov, M; Clarke, R; Smith, K; Campbell, F; Merriman, C; Criddle, D; Sutton, R; Neoptolemos, J; Vlatković, N

    2014-01-01

    Hereditary pancreatitis (HP) is an autosomal dominant disease that displays the features of both acute and chronic pancreatitis. Mutations in human cationic trypsinogen (PRSS1) are associated with HP and have provided some insight into the pathogenesis of pancreatitis, but mechanisms responsible for the initiation of pancreatitis have not been elucidated and the role of apoptosis and necrosis has been much debated. However, it has been generally accepted that trypsinogen, prematurely activated within the pancreatic acinar cell, has a major role in the initiation process. Functional studies of HP have been limited by the absence of an experimental system that authentically mimics disease development. We therefore developed a novel transgenic murine model system using wild-type (WT) human PRSS1 or two HP-associated mutants (R122H and N29I) to determine whether expression of human cationic trypsinogen in murine acinar cells promotes pancreatitis. The rat elastase promoter was used to target transgene expression to pancreatic acinar cells in three transgenic strains that were generated: Tg(Ela-PRSS1)NV, Tg(Ela-PRSS1*R122H)NV and Tg(Ela-PRSS1*N29I)NV. Mice were analysed histologically, immunohistochemically and biochemically. We found that transgene expression is restricted to pancreatic acinar cells and transgenic PRSS1 proteins are targeted to the pancreatic secretory pathway. Animals from all transgenic strains developed pancreatitis characterised by acinar cell vacuolisation, inflammatory infiltrates and fibrosis. Transgenic animals also developed more severe pancreatitis upon treatment with low-dose cerulein than controls, displaying significantly higher scores for oedema, inflammation and overall histopathology. Expression of PRSS1, WT or mutant, in acinar cells increased apoptosis in pancreatic tissues and isolated acinar cells. Moreover, studies of isolated acinar cells demonstrated that transgene expression promotes apoptosis rather than necrosis. We therefore

  18. [Gelatin/alginate hydrogel scaffolds prepared by 3D bioprinting promotes cell adhesion and proliferation of human dental pulp cells in vitro].

    Science.gov (United States)

    Yu, Hai-Yue; Ma, Dan-Dan; Wu, Bu-Ling

    2017-05-20

    To evaluate the cytotoxicity of gelatin/alginate hydrogel scaffolds prepared by 3D bioprinting in human dental pulp cells (HDPCs) and compare the cell adhesion and proliferation of the cells seeded in the biomaterial using two different methods. HDPCs isolated by tissue block culture and enzyme digestion were cultured and passaged. Gelatin/alginate hydrogel scaffolds were printed using a bioplotter, and the cytotoxicity of the aqueous extracts of the scaffold material was tested in the third passage of HDPCs using cell counting kit-8. Scanning electron microscopy and trypan blue were used to assess the adhesion and proliferation of the cells seeded in the scaffold material at a low or high concentration. The aqueous extract of the scaffolds at different concentrations showed no obvious cytotoxicity and promoted the proliferation of HDPCs. The scaffolds had a good biocompatibility and HDPCs seeded in the scaffold showed good cell growth. Cell seeding at a high concentration in the scaffold better promoted the adhesion of HDPCs and resulted in a greater cell number on the scaffold surface compared with low-concentration cell seeding after a 5-day culture (Palginate hydrogel scaffolds prepared by 3D bioprinting has a good biocompatibility and promotes the proliferation of HDPCs, and can be used as a scaffold material for tooth regeneration. Cell seeding at a high concentration can better promote cell adhesion to the scaffold material.

  19. Induction of Foxp3-expressing regulatory T-cells by donor blood transfusion is required for tolerance to rat liver allografts.

    Directory of Open Access Journals (Sweden)

    Yuta Abe

    Full Text Available BACKGROUND: Donor-specific blood transfusion (DST prior to solid organ transplantation has been shown to induce long-term allograft survival in the absence of immunosuppressive therapy. Although the mechanisms underlying DST-induced allograft tolerance are not well defined, there is evidence to suggest DST induces one or more populations of antigen-specific regulatory cells that suppress allograft rejection. However, neither the identity nor the regulatory properties of these tolerogenic lymphocytes have been reported. Therefore, the objective of this study was to define the kinetics, phenotype and suppressive function of the regulatory cells induced by DST alone or in combination with liver allograft transplantation (LTx. METHODOLOGY/PRINCIPAL FINDINGS: Tolerance to Dark Agouti (DA; RT1(a rat liver allografts was induced by injection (iv of 1 ml of heparinized DA blood to naïve Lewis (LEW; RT1(l rats once per week for 4 weeks prior to LTx. We found that preoperative DST alone generates CD4(+ T-cells that when transferred into naïve LEW recipients are capable of suppressing DA liver allograft rejection and promoting long-term survival of the graft and recipient. However, these DST-generated T-cells did not express the regulatory T-cell (Treg transcription factor Foxp3 nor did they suppress alloantigen (DA-induced activation of LEW T-cells in vitro suggesting that these lymphocytes are not fully functional regulatory Tregs. We did observe that DST+LTx (but not DST alone induced the time-dependent formation of CD4(+Foxp3(+ Tregs that potently suppressed alloantigen-induced activation of naïve LEW T-cells in vitro and liver allograft rejection in vivo. Finally, we present data demonstrating that virtually all of the Foxp3-expressing Tregs reside within the CD4(+CD45RC(- population whereas in which approximately 50% of these Tregs express CD25. CONCLUSIONS/SIGNIFICANCE: We conclude that preoperative DST, in the absence of liver allograft

  20. Novel NAC transcription factor TaNAC67 confers enhanced multi-abiotic stress tolerances in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Xinguo Mao

    Full Text Available Abiotic stresses are major environmental factors that affect agricultural productivity worldwide. NAC transcription factors play pivotal roles in abiotic stress signaling in plants. As a staple crop, wheat production is severely constrained by abiotic stresses whereas only a few NAC transcription factors have been characterized functionally. To promote the application of NAC genes in wheat improvement by biotechnology, a novel NAC gene designated TaNAC67 was characterized in common wheat. To determine its role, transgenic Arabidopsis overexpressing TaNAC67-GFP controlled by the CaMV-35S promoter was generated and subjected to various abiotic stresses for morphological and physiological assays. Gene expression showed that TaNAC67 was involved in response to drought, salt, cold and ABA treatments. Localization assays revealed that TaNAC67 localized in the nucleus. Morphological analysis indicated the transgenics had enhanced tolerances to drought, salt and freezing stresses, simultaneously supported by enhanced expression of multiple abiotic stress responsive genes and improved physiological traits, including strengthened cell membrane stability, retention of higher chlorophyll contents and Na(+ efflux rates, improved photosynthetic potential, and enhanced water retention capability. Overexpression of TaNAC67 resulted in pronounced enhanced tolerances to drought, salt and freezing stresses, therefore it has potential for utilization in transgenic breeding to improve abiotic stress tolerance in crops.

  1. Identifying and engineering promoters for high level and sustainable therapeutic recombinant protein production in cultured mammalian cells.

    Science.gov (United States)

    Ho, Steven C L; Yang, Yuansheng

    2014-08-01

    Promoters are essential on plasmid vectors to initiate transcription of the transgenes when generating therapeutic recombinant proteins expressing mammalian cell lines. High and sustained levels of gene expression are desired during therapeutic protein production while gene expression is useful for cell engineering. As many finely controlled promoters exhibit cell and product specificity, new promoters need to be identified, optimized and carefully evaluated before use. Suitable promoters can be identified using techniques ranging from simple molecular biology methods to modern high-throughput omics screenings. Promoter engineering is often required after identification to either obtain high and sustained expression or to provide a wider range of gene expression. This review discusses some of the available methods to identify and engineer promoters for therapeutic recombinant protein expression in mammalian cells.

  2. Cognitive component of Tolerance in Pedagogic Education

    Directory of Open Access Journals (Sweden)

    O. V. Akimova

    2013-01-01

    Full Text Available The paper looks at one of the urgent educational problems of tolerance development by teachers and students; tolerance being viewed as the openness to the new knowledge acquisition, willingness to understand other people and cooperate with them, and therefore the opportunity for self- development.The paper outlines the ways of tolerant attitudes formation by all the human subjects of educational process; the concept of person oriented teaching is considered to be the basic one for tolerance development. To optimize the specialists’ training for communication at any level of professional environment, the cognitive activity educational model is suggested, providing the ways out of any complicated pedagogical situation. The cognitive psychology concepts give the background for the above model. The education in question promotes the intellectual level of the prospective teachers, intensifies their creative potential, methodological thinking and practical experience, as well as tolerance development in professional communication process. 

  3. Effects of exendin-4 on glucose tolerance, insulin secretion, and beta-cell proliferation depend on treatment dose, treatment duration and meal contents

    International Nuclear Information System (INIS)

    Arakawa, Masayuki; Ebato, Chie; Mita, Tomoya; Hirose, Takahisa; Kawamori, Ryuzo; Fujitani, Yoshio; Watada, Hirotaka

    2009-01-01

    Beta-cell proliferation is regulated by various metabolic demands including peripheral insulin resistance, obesity, and hyperglycemia. In addition to enhancement of glucose-induced insulin secretion, agonists for glucagon-like peptide-1 receptor (GLP-1R) stimulate proliferation and inhibit apoptosis of beta-cells, thereby probably preserve beta-cell mass. To evaluate the beta-cell preserving actions of GLP-1R agonists, we assessed the acute and chronic effects of exendin-4 on beta-cell proliferation, mass and glucose tolerance in C57BL/6J mice under various conditions. Short-term administration of high-dose exendin-4 transiently stimulated beta-cell proliferation. Comparative transcriptomic analysis showed upregulation of IGF-1 receptor and its downstream effectors in islets. Treatment of mice with exendin-4 daily for 4 weeks (long-term administration) and feeding high-fat diet resulted in significant inhibition of weight gain and improvement of glucose tolerance with reduced insulin secretion and beta-cell mass. These findings suggest that long-term GLP-1 treatment results in insulin sensitization of peripheral organs, rather than enhancement of beta-cell proliferation and function, particularly when animals are fed high-fat diet. Thus, the effects of exendin-4 on glucose tolerance, insulin secretion, and beta-cell proliferation largely depend on treatment dose, duration of treatment and meal contents. While GLP-1 enhances proliferation of beta-cells in some diabetic mice models, our results suggest that GLP-1 stimulates beta-cell growth only when expansion of beta-cell mass is required to meet metabolic demands.

  4. Effects of exendin-4 on glucose tolerance, insulin secretion, and beta-cell proliferation depend on treatment dose, treatment duration and meal contents

    Energy Technology Data Exchange (ETDEWEB)

    Arakawa, Masayuki; Ebato, Chie; Mita, Tomoya [Department of Medicine, Metabolism and Endocrinology, Juntendo University School of Medicine, Tokyo (Japan); Hirose, Takahisa [Department of Medicine, Metabolism and Endocrinology, Juntendo University School of Medicine, Tokyo (Japan); Center for Therapeutic Innovations in Diabetes, Juntendo University School of Medicine, Tokyo (Japan); Kawamori, Ryuzo [Department of Medicine, Metabolism and Endocrinology, Juntendo University School of Medicine, Tokyo (Japan); Center for Therapeutic Innovations in Diabetes, Juntendo University School of Medicine, Tokyo (Japan); Center for Beta Cell Biology and Regeneration, Juntendo University School of Medicine, Tokyo (Japan); Sportology Center, Juntendo University School of Medicine, Tokyo (Japan); Fujitani, Yoshio, E-mail: fujitani@juntendo.ac.jp [Department of Medicine, Metabolism and Endocrinology, Juntendo University School of Medicine, Tokyo (Japan); Center for Therapeutic Innovations in Diabetes, Juntendo University School of Medicine, Tokyo (Japan); Watada, Hirotaka, E-mail: hwatada@juntendo.ac.jp [Department of Medicine, Metabolism and Endocrinology, Juntendo University School of Medicine, Tokyo (Japan); Sportology Center, Juntendo University School of Medicine, Tokyo (Japan)

    2009-12-18

    Beta-cell proliferation is regulated by various metabolic demands including peripheral insulin resistance, obesity, and hyperglycemia. In addition to enhancement of glucose-induced insulin secretion, agonists for glucagon-like peptide-1 receptor (GLP-1R) stimulate proliferation and inhibit apoptosis of beta-cells, thereby probably preserve beta-cell mass. To evaluate the beta-cell preserving actions of GLP-1R agonists, we assessed the acute and chronic effects of exendin-4 on beta-cell proliferation, mass and glucose tolerance in C57BL/6J mice under various conditions. Short-term administration of high-dose exendin-4 transiently stimulated beta-cell proliferation. Comparative transcriptomic analysis showed upregulation of IGF-1 receptor and its downstream effectors in islets. Treatment of mice with exendin-4 daily for 4 weeks (long-term administration) and feeding high-fat diet resulted in significant inhibition of weight gain and improvement of glucose tolerance with reduced insulin secretion and beta-cell mass. These findings suggest that long-term GLP-1 treatment results in insulin sensitization of peripheral organs, rather than enhancement of beta-cell proliferation and function, particularly when animals are fed high-fat diet. Thus, the effects of exendin-4 on glucose tolerance, insulin secretion, and beta-cell proliferation largely depend on treatment dose, duration of treatment and meal contents. While GLP-1 enhances proliferation of beta-cells in some diabetic mice models, our results suggest that GLP-1 stimulates beta-cell growth only when expansion of beta-cell mass is required to meet metabolic demands.

  5. Oral tolerance induction with altered forms of ovalbumin

    Directory of Open Access Journals (Sweden)

    Stransky B.

    1998-01-01

    Full Text Available As a T cell-dependent phenomenon, oral tolerance is not expected to depend necessarily on native configuration of antigens. We investigated the induction of oral tolerance with modified ovalbumin (Ova. Oral administration of heat-denatured (HD-Ova and cyanogen bromide-degraded ovalbumin was less effective than native Ova in inducing oral tolerance in B6D2F1 mice. HD-Ova was effective in suppressing delayed-type hypersensitivity (DTH reactions but did not suppress specific antibody formation. Injection of Ova directly into the stomach, but not into the ileum or cecum, suppressed subsequent immunization to DTH reactions. Gavage with protease inhibitors (aprotinin or ovomucoid before gavage with Ova was ineffective in blocking tolerance induction. Treatment with hydroxyurea to destroy cycling cells 24 h before gavage with Ova blocked oral tolerance induction and also the possibility to passively transfer tolerance to naive recipients with the serum of mice gavaged with Ova 1 h before. The implications of these findings about oral tolerance induction are discussed

  6. Failure of Elevating Calcium Induces Oxidative Stress Tolerance and Imparts Cisplatin Resistance in Ovarian Cancer Cells

    OpenAIRE

    Ma, Liwei; Wang, Hongjun; Wang, Chunyan; Su, Jing; Xie, Qi; Xu, Lu; Yu, Yang; Liu, Shibing; Li, Songyan; Xu, Ye; Li, Zhixin

    2016-01-01

    Cisplatin is a commonly used chemotherapeutic drug, used for the treatment of malignant ovarian cancer, but acquired resistance limits its application. There is therefore an overwhelming need to understand the mechanism of cisplatin resistance in ovarian cancer, that is, ovarian cancer cells are insensitive to cisplatin treatment. Here, we show that failure of elevating calcium and oxidative stress tolerance play key roles in cisplatin resistance in ovarian cancer cell lines. Cisplatin induce...

  7. Cellular aspects of tolerance. V. The in vivo cooperative role of acceessory and thymus derived cells in responsiveness and unresponsiveness of SJL mice

    International Nuclear Information System (INIS)

    Fujiwara, M.; Cinader, B.

    1974-01-01

    Adult (8-week-old) SJL mice reach a relatively low degree of tolerance when injected with aggregate free rabbit γ-globulin (RGG). To analyze this phenomenon, we first examined indirect plaque-forming responses (PFC) in terms of participation of accessory and thymus-derived cells. Double transfer experiments were used; accessory cells were removed from donor cells by filtration over glasswool and their capacity reduced in recipients by 3 day preirradiation or by horse erythrocyte-mediated blockage. Using this type of experimental arrangement we found that the antibody response to RGG required the cooperation of accessory and thymus-derived cells. The induction of tolerance was affected by the presence of accessory cells. Preirradiated secondary recipients were reconstituted with spleen cells from accessory cell-deprived donors which had received thymus and bone marrow cells. In some experiments, the thymus and bone marrow cells were passed over glasswool. The primary recipients were left untreated or were given tolerogen. A more profound state of tolerance (reduction in plaque forming response) was the consequence of the incapacitation or removal of accessory cells. The magnitude of the reduction in PFC was directly related to the completeness of accessory cell removal and incapacitation. Responsiveness could be restored by administration of irradiated spleen cells as a source of accessory cells. The need for thymus-derived (T) cells in the antibody response was demonstrated by double transfer experiments in which the primary recipient was restored with thymus cells alone, bone marrow cells alone, or with a mixture of cell types

  8. Activated iNKT cells promote memory CD8+ T cell differentiation during viral infection.

    Directory of Open Access Journals (Sweden)

    Emma C Reilly

    Full Text Available α-Galactosylceramide (α-GalCer is the prototypical lipid ligand for invariant NKT cells. Recent studies have proposed that α-GalCer is an effective adjuvant in vaccination against a range of immune challenges, however its mechanism of action has not been completely elucidated. A variety of delivery methods have been examined including pulsing dendritic cells with α-GalCer to optimize the potential of α-GalCer. These methods are currently being used in a variety of clinical trials in patients with advanced cancer but cannot be used in the context of vaccine development against pathogens due to their complexity. Using a simple delivery method, we evaluated α-GalCer adjuvant properties, using the mouse model for cytomegalovirus (MCMV. We measured several key parameters of the immune response to MCMV, including inflammation, effector, and central memory CD8(+ T cell responses. We found that α-GalCer injection at the time of the infection decreases viral titers, alters the kinetics of the inflammatory response, and promotes both increased frequencies and numbers of virus-specific memory CD8(+ T cells. Overall, our data suggest that iNKT cell activation by α-GalCer promotes the development of long-term protective immunity through increased fitness of central memory CD8(+ T cells, as a consequence of reduced inflammation.

  9. Mechanism of oral tolerance induction to therapeutic proteins.

    Science.gov (United States)

    Wang, Xiaomei; Sherman, Alexandra; Liao, Gongxian; Leong, Kam W; Daniell, Henry; Terhorst, Cox; Herzog, Roland W

    2013-06-15

    Oral tolerance is defined as the specific suppression of humoral and/or cellular immune responses to an antigen by administration of the same antigen through the oral route. Due to its absence of toxicity, easy administration, and antigen specificity, oral tolerance is a very attractive approach to prevent unwanted immune responses that cause a variety of diseases or that complicate treatment of a disease. Many researchers have induced oral tolerance to efficiently treat autoimmune and inflammatory diseases in different animal models. However, clinical trials yielded limited success. Thus, understanding the mechanisms of oral tolerance induction to therapeutic proteins is critical for paving the way for clinical development of oral tolerance protocols. This review will summarize progress on understanding the major underlying tolerance mechanisms and contributors, including antigen presenting cells, regulatory T cells, cytokines, and signaling pathways. Potential applications, examples for therapeutic proteins and disease targets, and recent developments in delivery methods are discussed. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Immuno-therapy with anti-CTLA4 antibodies in tolerized and non-tolerized mouse tumor models.

    Directory of Open Access Journals (Sweden)

    Jonas Persson

    Full Text Available Monoclonal antibodies specific for cytotoxic T lymphocyte-associated antigen 4 (anti-CTLA4 are a novel form of cancer immunotherapy. While preclinical studies in mouse tumor models have shown anti-tumor efficacy of anti-CTLA4 injection or expression, anti-CTLA4 treatment in patients with advanced cancers had disappointing therapeutic benefit. These discrepancies have to be addressed in more adequate pre-clinical models. We employed two tumor models. The first model is based on C57Bl/6 mice and syngeneic TC-1 tumors expressing HPV16 E6/E7. In this model, the HPV antigens are neo-antigens, against which no central tolerance exists. The second model involves mice transgenic for the proto-oncogen neu and syngeneic mouse mammary carcinoma (MMC cells. In this model tolerance to Neu involves both central and peripheral mechanisms. Anti-CTLA4 delivery as a protein or expression from gene-modified tumor cells were therapeutically efficacious in the non-tolerized TC-1 tumor model, but had no effect in the MMC-model. We also used the two tumor models to test an immuno-gene therapy approach for anti-CTLA4. Recently, we used an approach based on hematopoietic stem cells (HSC to deliver the relaxin gene to tumors and showed that this approach facilitates pre-existing anti-tumor T-cells to control tumor growth in the MMC tumor model. However, unexpectedly, when used for anti-CTLA4 gene delivery in this study, the HSC-based approach was therapeutically detrimental in both the TC-1 and MMC models. Anti-CTLA4 expression in these models resulted in an increase in the number of intratumoral CD1d+ NKT cells and in the expression of TGF-β1. At the same time, levels of pro-inflammatory cytokines and chemokines, which potentially can support anti-tumor T-cell responses, were lower in tumors of mice that received anti-CTLA4-HSC therapy. The differences in outcomes between the tolerized and non-tolerized models also provide a potential explanation for the low efficacy

  11. Follicular B Cells Promote Atherosclerosis via T Cell-Mediated Differentiation Into Plasma Cells and Secreting Pathogenic Immunoglobulin G.

    Science.gov (United States)

    Tay, Christopher; Liu, Yu-Han; Kanellakis, Peter; Kallies, Axel; Li, Yi; Cao, Anh; Hosseini, Hamid; Tipping, Peter; Toh, Ban-Hock; Bobik, Alex; Kyaw, Tin

    2018-05-01

    B cells promote or protect development of atherosclerosis. In this study, we examined the role of MHCII (major histocompatibility II), CD40 (cluster of differentiation 40), and Blimp-1 (B-lymphocyte-induced maturation protein) expression by follicular B (FO B) cells in development of atherosclerosis together with the effects of IgG purified from atherosclerotic mice. Using mixed chimeric Ldlr -/- mice whose B cells are deficient in MHCII or CD40, we demonstrate that these molecules are critical for the proatherogenic actions of FO B cells. During development of atherosclerosis, these deficiencies affected T-B cell interactions, germinal center B cells, plasma cells, and IgG. As FO B cells differentiating into plasma cells require Blimp-1, we also assessed its role in the development of atherosclerosis. Blimp-1-deficient B cells greatly attenuated atherosclerosis and immunoglobulin-including IgG production, preventing IgG accumulation in atherosclerotic lesions; Blimp-1 deletion also attenuated lesion proinflammatory cytokines, apoptotic cell numbers, and necrotic core. To determine the importance of IgG for atherosclerosis, we purified IgG from atherosclerotic mice. Their transfer but not IgG from nonatherosclerotic mice into Ldlr -/- mice whose B cells are Blimp-1-deficient increased atherosclerosis; transfer was associated with IgG accumulating in atherosclerotic lesions, increased lesion inflammatory cytokines, apoptotic cell numbers, and necrotic core size. The mechanism by which FO B cells promote atherosclerosis is highly dependent on their expression of MHCII, CD40, and Blimp-1. FO B cell differentiation into IgG-producing plasma cells also is critical for their proatherogenic actions. Targeting B-T cell interactions and pathogenic IgG may provide novel therapeutic strategies to prevent atherosclerosis and its adverse cardiovascular complications. © 2018 American Heart Association, Inc.

  12. Human Nanog pseudogene8 promotes the proliferation of gastrointestinal cancer cells

    International Nuclear Information System (INIS)

    Uchino, Keita; Hirano, Gen; Hirahashi, Minako; Isobe, Taichi; Shirakawa, Tsuyoshi; Kusaba, Hitoshi; Baba, Eishi; Tsuneyoshi, Masazumi; Akashi, Koichi

    2012-01-01

    There is emerging evidence that human solid tumor cells originate from cancer stem cells (CSCs). In cancer cell lines, tumor-initiating CSCs are mainly found in the side population (SP) that has the capacity to extrude dyes such as Hoechst 33342. We found that Nanog is expressed specifically in SP cells of human gastrointestinal (GI) cancer cells. Nucleotide sequencing revealed that NanogP8 but not Nanog was expressed in GI cancer cells. Transfection of NanogP8 into GI cancer cell lines promoted cell proliferation, while its inhibition by anti-Nanog siRNA suppressed the proliferation. Immunohistochemical staining of primary GI cancer tissues revealed NanogP8 protein to be strongly expressed in 3 out of 60 cases. In these cases, NanogP8 was found especially in an infiltrative part of the tumor, in proliferating cells with Ki67 expression. These data suggest that NanogP8 is involved in GI cancer development in a fraction of patients, in whom it presumably acts by supporting CSC proliferation. -- Highlights: ► Nanog maintains pluripotency by regulating embryonic stem cells differentiation. ► Nanog is expressed in cancer stem cells of human gastrointestinal cancer cells. ► Nucleotide sequencing revealed that Nanog pseudogene8 but not Nanog was expressed. ► Nanog pseudogene8 promotes cancer stem cells proliferation. ► Nanog pseudogene8 is involved in gastrointestinal cancer development.

  13. High Tolerance of Hydrogenothermus marinus to Sodium Perchlorate

    Directory of Open Access Journals (Sweden)

    Kristina Beblo-Vranesevic

    2017-07-01

    Full Text Available On Mars, significant amounts (0.4–0.6% of perchlorate ions were detected in dry soil by the Phoenix Wet Chemistry Laboratory and later confirmed with the Mars Science Laboratory. Therefore, the ability of Hydrogenothermus marinus, a desiccation tolerant bacterium, to survive and grow in the presence of perchlorates was determined. Results indicated that H. marinus was able to tolerate concentrations of sodium perchlorate up to 200 mM ( 1.6% during cultivation without any changes in its growth pattern. After the addition of up to 440 mM ( 3.7% sodium perchlorate, H. marinus showed significant changes in cell morphology; from single motile short rods to long cell chains up to 80 cells. Furthermore, it was shown that the known desiccation tolerance of H. marinus is highly influenced by a pre-treatment with different perchlorates; additive effects of desiccation and perchlorate treatments are visible in a reduced survival rate. These data demonstrate that thermophiles, especially H. marinus, have so far, unknown high tolerances against cell damaging treatments and may serve as model organisms for future space experiments.

  14. The flavoprotein Tah18-dependent NO synthesis confers high-temperature stress tolerance on yeast cells

    International Nuclear Information System (INIS)

    Nishimura, Akira; Kawahara, Nobuhiro; Takagi, Hiroshi

    2013-01-01

    Highlights: ► NO is produced from L-arginine in response to elevated temperature in yeast. ► Tah18 was first identified as the yeast protein involved in NO synthesis. ► Tah18-dependent NO synthesis confers tolerance to high-temperature on yeast cells. -- Abstract: Nitric oxide (NO) is a ubiquitous signaling molecule involved in the regulation of a large number of cellular functions. In the unicellular eukaryote yeast, NO may be involved in stress response pathways, but its role is poorly understood due to the lack of mammalian NO synthase (NOS) orthologues. Previously, we have proposed the oxidative stress-induced L-arginine synthesis and its physiological role under stress conditions in yeast Saccharomyces cerevisiae. Here, our experimental results indicated that increased conversion of L-proline into L-arginine led to NO production in response to elevated temperature. We also showed that the flavoprotein Tah18, which was previously reported to transfer electrons to the Fe–S cluster protein Dre2, was involved in NO synthesis in yeast. Gene knockdown analysis demonstrated that Tah18-dependent NO synthesis confers high-temperature stress tolerance on yeast cells. As it appears that such a unique cell protection mechanism is specific to yeasts and fungi, it represents a promising target for antifungal activity.

  15. Effect of metal tolerant plant growth promoting bacteria on growth and metal accumulation in Zea mays plants grown in fly ash amended soil.

    Science.gov (United States)

    Kumar, Kalpna V; Patra, D D

    2013-01-01

    The present study was undertaken to examine the effect of the application of fly ash (FA) into Garden soil (GS), with and without inoculation of plant growth promoting bacteria (PGPB), on the growth and metal uptake by Zea mays plants. Three FA tolerant PGPB strains, Pseudomonas sp. PS5, PS14, and Bacillus sp. BC29 were isolated from FA contaminated soils and assessed for their plant growth promoting features on the Z. mays plants. All three strains were also examined for their ability to solubilize phosphate and to produce Indole Acetic Acid (IAA), siderophores, and hydrogencynide acid (HCN) production. Although inoculation of all strains significantly enhanced the growth of plants at both the concentration of FA but maximum growth was observed in plants inoculated with BC29 and PS14 at low level (25%) of FA concentration. The experimental results explored the plant growth promoting features of selected strains which not only enhanced growth and biomass of plants but also protected them from toxicity of FA.

  16. Teaching Tolerance in a Globalized World

    NARCIS (Netherlands)

    Sandoval-Hernández, Andrés; Isac, Maria Magdalena; Miranda, Daniel

    2018-01-01

    This open access thematic report identifies factors and conditions that can help schools and education systems promote tolerance in a globalized world. The IEA’s International Civic and Citizenship Study (ICCS) is a comparative research program designed to investigate the ways in which young people

  17. Therapeutic Potential of Invariant Natural Killer T Cells in Autoimmunity

    Directory of Open Access Journals (Sweden)

    Luc Van Kaer

    2018-03-01

    Full Text Available Tolerance against self-antigens is regulated by a variety of cell types with immunoregulatory properties, such as CD1d-restricted invariant natural killer T (iNKT cells. In many experimental models of autoimmunity, iNKT cells promote self-tolerance and protect against autoimmunity. These findings are supported by studies with patients suffering from autoimmune diseases. Based on these studies, the therapeutic potential of iNKT cells in autoimmunity has been explored. Many of these studies have been performed with the potent iNKT cell agonist KRN7000 or its structural variants. These findings have generated promising results in several autoimmune diseases, although mechanisms by which iNKT cells modulate autoimmunity remain incompletely understood. Here, we will review these preclinical studies and discuss the prospects for translating their findings to patients suffering from autoimmune diseases.

  18. ALA Pretreatment Improves Waterlogging Tolerance of Fig Plants.

    Directory of Open Access Journals (Sweden)

    Yuyan An

    Full Text Available 5-aminolevulinic acid (ALA, a natural and environmentally friendly plant growth regulator, can improve plant tolerance to various environmental stresses. However, whether ALA can improve plant waterlogging tolerance is unknown. Here, we investigated the effects of ALA pretreatment on the waterlogging-induced damage of fig (Ficus carica Linn. plants, which often suffer from waterlogging stress. ALA pretreatment significantly alleviated stress-induced morphological damage, increased leaf relative water content (RWC, and reduced leaf superoxide anion ([Formula: see text] production rate and malonaldehyde (MDA content in fig leaves, indicating ALA mitigates waterlogging stress of fig plants. We further demonstrated that ALA pretreatment largely promoted leaf chlorophyll content, photosynthetic electron transfer ability, and photosynthetic performance index, indicating ALA significantly improves plant photosynthetic efficiency under waterlogging stress. Moreover, ALA pretreatment significantly increased activities of leaf superoxide dismutase (SOD and peroxidase (POD, root vigor, and activities of root alcohol dehydrogenase (ADH, and lactate dehydrogenase (LDH, indicating ALA also significantly improves antioxidant ability and root function of fig plants under waterlogging stress. Taken together, ALA pretreatment improves waterlogging tolerance of fig plants significantly, and the promoted root respiration, leaf photosynthesis, and antioxidant ability may contribute greatly to this improvement. Our data firstly shows that ALA can improve plant waterlogging tolerance.

  19. Live-cell Imaging of Pol II Promoter Activity to Monitor Gene expression with RNA IMAGEtag reporters

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Ilchung [Ames Laboratory; Ray, Judhajeet [Ames Laboratory; Gupta, Vinayak [Iowa State University; Ilgu, Muslum [Ames Laboratory; Beasley, Jonathan [Iowa State University; Bendickson, Lee [Ames Laboratory; Mehanovic, Samir [Molecular Express; Kraus, George A. [Iowa State University; Nilsen-Hamilton, Marit [Ames Laboratory

    2014-04-20

    We describe a ribonucleic acid (RNA) reporter system for live-cell imaging of gene expression to detect changes in polymerase II activity on individual promoters in individual cells. The reporters use strings of RNA aptamers that constitute IMAGEtags (Intracellular MultiAptamer GEnetic tags) that can be expressed from a promoter of choice. For imaging, the cells are incubated with their ligands that are separately conjugated with one of the FRET pair, Cy3 and Cy5. The IMAGEtags were expressed in yeast from the GAL1, ADH1 or ACT1 promoters. Transcription from all three promoters was imaged in live cells and transcriptional increases from the GAL1 promoter were observed with time after adding galactose. Expression of the IMAGEtags did not affect cell proliferation or endogenous gene expression. Advantages of this method are that no foreign proteins are produced in the cells that could be toxic or otherwise influence the cellular response as they accumulate, the IMAGEtags are short lived and oxygen is not required to generate their signals. The IMAGEtag RNA reporter system provides a means of tracking changes in transcriptional activity in live cells and in real time.

  20. High frequency of p 16 promoter methylation in non-small cell lung carcinomas from Chile

    Directory of Open Access Journals (Sweden)

    LEDA M GUZMAN

    2007-01-01

    Full Text Available The inactivation of tumour suppressor genes by aberrant methylation of promoter regions has been described as a frequent event in neoplasia development, including lung cancer. The p16 gene is a tumour suppressor gene involved in the regulation of cell cycle progression that has been reported to be inactivated by promoter methylation in lung carcinomas at variable frequencies around the world in a smoking habit dependent manner. The purpose of this study was to investigate the methylation status of the promoter region of the p16 gene in 74 non-small cell lung carcinomas from Chile. The frequency of p16 gene inactivation by promoter methylation was determined as 79.7% (59/74. When we considered histological type, we observed that p16 promoter methylation was significantly higher in squamous cell carcinomas (30/33, 91% compared with adenocarcinomas (21/30, 70% (p=0.029. In addition, no association between p16 promoter methylation and gender, age or smoking habit was found (p=0.202, 0.202 and 0.147 respectively. Our results suggest that p16 promoter hypermethylation is a very frequent event in non-small cell lung carcinomas from Chile and could be smoking habit-independent

  1. Sublethal irradiation promotes invasiveness of neuroblastoma cells

    International Nuclear Information System (INIS)

    Schweigerer, Lothar; Rave-Fraenk, Margret; Schmidberger, Heinz; Hecht, Monica

    2005-01-01

    Neuroblastoma is the most frequent extracranial solid tumour of childhood. Despite multiple clinical efforts, clinical outcome has remained poor. Neuroblastoma is considered to be radiosensitive, but some clinical studies including the German trial NB90 failed to show a clinical benefit of radiation therapy. The mechanisms underlying this apparent discrepancy are still unclear. We have therefore investigated the effects of radiation on neuroblastoma cell behaviour in vitro. We show that sublethal doses of irradiation up-regulated the expression of the hepatocyte growth factor (HGF) and its receptor c-Met in some neuroblastoma cell lines. The increase in HGF/c-Met expression was correlated with enhanced invasiveness and activation of proteases degrading the extracellular matrix. Thus, irradiation at sublethal doses may promote the metastatic dissemination of neuroblastoma cells through activating the HGF/c-Met pathway and triggering matrix degradation

  2. Characterization of the distal promoter of the human pyruvate carboxylase gene in pancreatic beta cells.

    Directory of Open Access Journals (Sweden)

    Ansaya Thonpho

    Full Text Available Pyruvate carboxylase (PC is an enzyme that plays a crucial role in many biosynthetic pathways in various tissues including glucose-stimulated insulin secretion. In the present study, we identify promoter usage of the human PC gene in pancreatic beta cells. The data show that in the human, two alternative promoters, proximal and distal, are responsible for the production of multiple mRNA isoforms as in the rat and mouse. RT-PCR analysis performed with cDNA prepared from human liver and islets showed that the distal promoter, but not the proximal promoter, of the human PC gene is active in pancreatic beta cells. A 1108 bp fragment of the human PC distal promoter was cloned and analyzed. It contains no TATA box but possesses two CCAAT boxes, and other putative transcription factor binding sites, similar to those of the distal promoter of rat PC gene. To localize the positive regulatory region in the human PC distal promoter, 5'-truncated and the 25-bp and 15-bp internal deletion mutants of the human PC distal promoter were generated and used in transient transfections in INS-1 832/13 insulinoma and HEK293T (kidney cell lines. The results indicated that positions -340 to -315 of the human PC distal promoter serve as (an activator element(s for cell-specific transcription factor, while the CCAAT box at -71/-67, a binding site for nuclear factor Y (NF-Y, as well as a GC box at -54/-39 of the human PC distal promoter act as activator sequences for basal transcription.

  3. Particle size dependence of CO tolerance of anode PtRu catalysts for polymer electrolyte fuel cells

    Science.gov (United States)

    Yamanaka, Toshiro; Takeguchi, Tatsuya; Wang, Guoxiong; Muhamad, Ernee Noryana; Ueda, Wataru

    An anode catalyst for a polymer electrolyte fuel cell must be CO-tolerant, that is, it must have the function of hydrogen oxidation in the presence of CO, because hydrogen fuel gas generated by the steam reforming process of natural gas contains a small amount of CO. In the present study, PtRu/C catalysts were prepared with control of the degree of Pt-Ru alloying and the size of PtRu particles. This control has become possible by a new method of heat treatment at the final step in the preparation of catalysts. The CO tolerances of PtRu/C catalysts with the same degree of Pt-Ru alloying and with different average sizes of PtRu particles were thus compared. Polarization curves were obtained with pure H 2 and CO/H 2 (CO concentrations of 500-2040 ppm). It was found that the CO tolerance of highly dispersed PtRu/C (high dispersion (HD)) with small PtRu particles was much higher than that of poorly dispersed PtRu/C (low dispersion (LD)) with large metal particles. The CO tolerance of PtRu/C (HD) was higher than that of any commercial PtRu/C. The high CO tolerance of PtRu/C (HD) is thought to be due to efficient concerted functions of Pt, Ru, and their alloy.

  4. Probiotics promote endocytic allergen degradation in gut epithelial cells

    International Nuclear Information System (INIS)

    Song, Chun-Hua; Liu, Zhi-Qiang; Huang, Shelly; Zheng, Peng-Yuan; Yang, Ping-Chang

    2012-01-01

    Highlights: ► Knockdown of A20 compromised the epithelial barrier function. ► The fusion of endosome/lysosome was disturbed in the A20-deficient HT-29 cells. ► Antigens transported across A20-deficient HT-29 monolayers conserved antigenicity. ► Probiotic proteins increased the expression of A20 in HT-29 cells. -- Abstract: Background and aims: Epithelial barrier dysfunction plays a critical role in the pathogenesis of allergic diseases; the mechanism is to be further understood. The ubiquitin E3 ligase A20 (A20) plays a role in the endocytic protein degradation in the cells. This study aims to elucidate the role of A20 in the maintenance of gut epithelial barrier function. Methods: Gut epithelial cell line, HT-29 cell, was cultured into monolayers to evaluate the barrier function in transwells. RNA interference was employed to knock down the A20 gene in HT-29 cells to test the role of A20 in the maintenance of epithelial barrier function. Probiotic derived proteins were extracted from the culture supernatants using to enhance the expression of A20 in HT-29 cells. Results: The results showed that the knockdown of A20 compromised the epithelial barrier function in HT-29 monolayers, mainly increased the intracellular permeability. The fusion of endosome/lysosome was disturbed in the A20-deficient HT-29 cells. Allergens collected from the transwell basal chambers of A20-deficient HT-29 monolayers still conserved functional antigenicity. Treating with probiotic derived proteins increased the expression of A20 in HT-29 cells and promote the barrier function. Conclusion: A20 plays an important role in the maintenance of epithelial barrier function as shown by HT-29 monolayer. Probiotic derived protein increases the expression of A20 and promote the HT-29 monolayer barrier function.

  5. Probiotics promote endocytic allergen degradation in gut epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Song, Chun-Hua [Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, Zhengzhou (China); Liu, Zhi-Qiang [Department of Gastroenterology, The Second Hospital, Zhengzhou University, Zhengzhou (China); Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON (Canada); Huang, Shelly [Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON (Canada); Zheng, Peng-Yuan, E-mail: medp7123@126.com [Department of Gastroenterology, The Second Hospital, Zhengzhou University, Zhengzhou (China); Yang, Ping-Chang, E-mail: yangp@mcmaster.ca [Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON (Canada)

    2012-09-14

    Highlights: Black-Right-Pointing-Pointer Knockdown of A20 compromised the epithelial barrier function. Black-Right-Pointing-Pointer The fusion of endosome/lysosome was disturbed in the A20-deficient HT-29 cells. Black-Right-Pointing-Pointer Antigens transported across A20-deficient HT-29 monolayers conserved antigenicity. Black-Right-Pointing-Pointer Probiotic proteins increased the expression of A20 in HT-29 cells. -- Abstract: Background and aims: Epithelial barrier dysfunction plays a critical role in the pathogenesis of allergic diseases; the mechanism is to be further understood. The ubiquitin E3 ligase A20 (A20) plays a role in the endocytic protein degradation in the cells. This study aims to elucidate the role of A20 in the maintenance of gut epithelial barrier function. Methods: Gut epithelial cell line, HT-29 cell, was cultured into monolayers to evaluate the barrier function in transwells. RNA interference was employed to knock down the A20 gene in HT-29 cells to test the role of A20 in the maintenance of epithelial barrier function. Probiotic derived proteins were extracted from the culture supernatants using to enhance the expression of A20 in HT-29 cells. Results: The results showed that the knockdown of A20 compromised the epithelial barrier function in HT-29 monolayers, mainly increased the intracellular permeability. The fusion of endosome/lysosome was disturbed in the A20-deficient HT-29 cells. Allergens collected from the transwell basal chambers of A20-deficient HT-29 monolayers still conserved functional antigenicity. Treating with probiotic derived proteins increased the expression of A20 in HT-29 cells and promote the barrier function. Conclusion: A20 plays an important role in the maintenance of epithelial barrier function as shown by HT-29 monolayer. Probiotic derived protein increases the expression of A20 and promote the HT-29 monolayer barrier function.

  6. A 310-bp minimal promoter mediates smooth muscle cell-specific expression of telokin.

    Science.gov (United States)

    Smith, A F; Bigsby, R M; Word, R A; Herring, B P

    1998-05-01

    A cell-specific promoter located in an intron of the smooth muscle myosin light chain kinase gene directs transcription of telokin exclusively in smooth muscle cells. Transgenic mice were generated in which a 310-bp rabbit telokin promoter fragment, extending from -163 to +147, was used to drive expression of simian virus 40 large T antigen. Smooth muscle-specific expression of the T-antigen transgene paralleled that of the endogenous telokin gene in all smooth muscle tissues except uterus. The 310-bp promoter fragment resulted in very low levels of transgene expression in uterus; in contrast, a transgene driven by a 2.4-kb fragment (-2250 to +147) resulted in high levels of transgene expression in uterine smooth muscle. Telokin expression levels correlate with the estrogen status of human myometrial tissues, suggesting that deletion of an estrogen response element (ERE) may account for the low levels of transgene expression driven by the 310-bp rabbit telokin promoter in uterine smooth muscle. Experiments in A10 smooth muscle cells directly showed that reporter gene expression driven by the 2.4-kb, but not 310-bp, promoter fragment could be stimulated two- to threefold by estrogen. This stimulation was mediated through an ERE located between -1447 and -1474. Addition of the ERE to the 310-bp fragment restored estrogen responsiveness in A10 cells. These data demonstrate that in addition to a minimal 310-bp proximal promoter at least one distal cis-acting regulatory element is required for telokin expression in uterine smooth muscle. The distal element may include an ERE between -1447 and -1474.

  7. Three-dimensional spheroid culture of human umbilical cord mesenchymal stem cells promotes cell yield and stemness maintenance.

    Science.gov (United States)

    Li, Yi; Guo, Gang; Li, Li; Chen, Fei; Bao, Ji; Shi, Yu-Jun; Bu, Hong

    2015-05-01

    Mesenchymal stem cell (MSC) transplantation is a promising treatment of many diseases. However, conventional techniques with cells being cultured as a monolayer result in slow cell proliferation and insufficient yield to meet clinical demands. Three-dimensional (3D) culture systems are gaining attention with regard to recreating a complex microenvironment and to understanding the conditions experienced by cells. Our aim is to establish a novel 3D system for the culture of human umbilical cord MSCs (hUC-MSCs) within a real 3D microenvironment but with no digestion or passaging. Primary hUC-MSCs were isolated and grown in serum-free medium (SFM) on a suspension Rocker system. Cell characteristics including proliferation, phenotype and multipotency were recorded. The therapeutic effects of 3D-cultured hUC-MSCs on carbon tetrachloride (CCl4)-induced acute liver failure in mouse models were examined. In the 3D Rocker system, hUC-MSCs formed spheroids in SFM and maintained high viability and active proliferation. Compared with monolayer culture, the 3D-culture system yielded more hUC-MSCs cells within the same volume. The spheroids expressed higher levels of stem cell markers and displayed stronger multipotency. After transplantation into mouse, 3D hUC-MSCs significantly promoted the secretion of interferon-γ and interleukin-6 but inhibited that of tumor necrosis factor-α, thereby alleviating liver necrosis and promoting regeneration following CCl4 injury. The 3D culture of hUC-MSCs thus promotes cell yield and stemness maintenance and represents a promising strategy for hUC-MSCs expansion on an industrial scale with great potential for cell therapy and biotechnology.

  8. AKT increases VEGF expression in tumor cells by transactivating the proximal VEGF promoter

    International Nuclear Information System (INIS)

    Pore, N.; Bernhard, E.J.; Shu, H.-K.; Li, B.; O'Rourke, D.M.; Maity, A.; Haas-Kogan, D.

    2003-01-01

    Vascular endothelial growth factor (VEGF) is overexpressed in many cancers including glioblastomas and may contribute to their growth. Epidermal growth factor receptor (EGFR) amplification and loss of PTEN, commonly found in glioblastomas leading to increase phosphatidylinositol-3-kinase (PI3K) activity and VEGF expression. In the current study we show that AKT, which is downstream of PI3K, regulates VEGF expression. U87MG human glioblastoma cells lack wildtype PTEN and express high levels of phosphorylated AKT. Over expression of AKT either by stable expression in immortalized human astrocytes or by transduction with adenovirus containing activated myristoylated AKT in SF188 glioblastoma cells increases VEGF expression. Moreover the elevation of angiogenesis by constitutively expressed AKT is further confirmed by in vivo matrigel plug assay in nude mice. The upregulation of VEGF by AKT is mediated through a region in the proximal promoter located between -88 and -70 (+1 is transcription start site). In transient transfection activity of a luciferase reporter containing the -88/+54 region of the VEGF promoter is increased by cotransfection with myristoylated AKT and downregulated by a dominant negative AKT expression vector. Mutation of the putative Sp1 binding sites located in the -88/-70 region we show that AKT acts through Sp1 to transactivate the VEGF promoter. Cotransfection of the VEGF promoter reporter with both Sp1 and myristoylated AKT expression vectors increases promoter activity to a greater extent than either Sp1 or Akt by itself. In vivo phosphate labeling of proteins reveals that AKT leads to increased Sp1 phosphorylation. Gel shift assays using a radio labeled probe corresponding to nucleotides -88 through -66 in the promoter show increased binding with nuclear extracts from cells transduced with adenovirus expressing myristoylated AKT. In conclusion, our results suggest that loss of PTEN leads to increased VEGF expression by increasing AKT

  9. Spatially and Temporally Regulated NRF2 Gene Therapy Using Mcp-1 Promoter in Retinal Ganglion Cell Injury

    Directory of Open Access Journals (Sweden)

    Kosuke Fujita

    2017-06-01

    Full Text Available Retinal ganglion cell degeneration triggered by axonal injury is believed to underlie many ocular diseases, including glaucoma and optic neuritis. In these diseases, retinal ganglion cells are affected unevenly, both spatially and temporally, such that healthy and unhealthy cells coexist in different patterns at different time points. Herein, we describe a temporally and spatially regulated adeno-associated virus gene therapy aiming to reduce undesired off-target effects on healthy retinal neurons. The Mcp-1 promoter previously shown to be activated in stressed retinal ganglion cells following murine optic nerve injury was combined with the neuroprotective intracellular transcription factor Nrf2. In this model, Mcp-1 promoter-driven NRF2 expression targeting only stressed retinal ganglion cells showed efficacy equivalent to non-selective cytomegalovirus promoter-driven therapy for preventing cell death. However, cytomegalovirus promoter-mediated NRF2 transcription induced cellular stress responses and death of Brn3A-positive uninjured retinal ganglion cells. Such undesired effects were reduced substantially by adopting the Mcp-1 promoter. Combining a stress-responsive promoter and intracellular therapeutic gene is a versatile approach for specifically targeting cells at risk of degeneration. This strategy may be applicable to numerous chronic ocular and non-ocular conditions.

  10. Glial cell line-derived neurotrophic factor and endothelial cells promote self-renewal of rabbit germ cells with spermatogonial stem cell properties.

    Science.gov (United States)

    Kubota, Hiroshi; Wu, Xin; Goodyear, Shaun M; Avarbock, Mary R; Brinster, Ralph L

    2011-08-01

    Previous studies suggest that exogenous factors crucial for spermatogonial stem cell (SSC) self-renewal are conserved among several mammalian species. Since glial cell line-derived neurotrophic factor (GDNF) and fibroblast growth factor 2 (FGF2) are critical for rodent SSC self-renewal, we hypothesized that they might promote self-renewal of nonrodent SSCs. Therefore, we cultured testicular germ cells from prepubertal rabbits in the presence of GDNF and FGF2 and found they proliferated indefinitely as cellular clumps that displayed characteristics previously identified for rodent SSCs. The rabbit germ cells could not be maintained on mouse embryonic fibroblast (STO) feeders that support rodent SSC self-renewal in vitro but were rather supported on mouse yolk sac-derived endothelial cell (C166) feeder layers. Proliferation of rabbit germ cells was dependent on GDNF. Of critical importance was that clump-forming rabbit germ cells colonized seminiferous tubules of immunodeficient mice, proliferated for at least 6 mo, while retaining an SSC phenotype in the testes of recipient mice, indicating that they were rabbit SSCs. This study demonstrates that GDNF is a mitogenic factor promoting self-renewal that is conserved between rodent and rabbit SSCs; with an evolutionary separation of ∼ 60 million years. These findings provide a foundation to study the mechanisms governing SSC self-renewal in nonrodent species.

  11. miR-4295 promotes cell proliferation and invasion in anaplastic thyroid carcinoma via CDKN1A

    International Nuclear Information System (INIS)

    Shao, Mingchen; Geng, Yiwei; Lu, Peng; Xi, Ying; Wei, Sidong; Wang, Liuxing; Fan, Qingxia; Ma, Wang

    2015-01-01

    MicroRNAs (miRNAs) play important roles in the pathogenesis of many types of cancers by negatively regulating gene expression at posttranscriptional level. However, the role of microRNAs in anaplastic thyroid carcinoma (ATC), has remained elusive. Here, we identified that miR-4295 promotes ATC cell proliferation by negatively regulates its target gene CDKN1A. In ATC cell lines, CCK-8 proliferation assay indicated that the cell proliferation was promoted by miR-4295, while miR-4295 inhibitor significantly inhibited the cell proliferation. Transwell assay showed that miR-4295 mimics significantly promoted the migration and invasion of ATC cells, whereas miR-4295 inhibitors significantly reduced cell migration and invasion. luciferase assays confirmed that miR-4295 directly bound to the 3'untranslated region of CDKN1A, and western blotting showed that miR-4295 suppressed the expression of CDKN1A at the protein levels. This study indicated that miR-4295 negatively regulates CDKN1A and promotes proliferation and invasion of ATC cell lines. Thus, miR-4295 may represent a potential therapeutic target for ATC intervention. - Highlights: • miR-4295 mimics promote the proliferation and invasion of ATC cells. • miR-4295 inhibitors inhibit the proliferation and invasion of ATC cells. • miR-4295 targets 3′UTR of CDKN1A in ATC cells. • miR-4295 negatively regulates CDKN1A in ATC cells

  12. Laboratory study on influence of plant growth promoting ...

    African Journals Online (AJOL)

    Aghomotsegin

    2015-03-06

    Mar 6, 2015 ... promoting rhizobacteria (PGPR) on growth response and tolerance of Zea ... inoculating maize seeds with plant growth promoting rhizobacterial strains in a crude oil impacted medium. ..... Botany and Environmental Health.

  13. Impact of pseudo-continuous fermentation on the ethanol tolerance of Scheffersomyces stipitis.

    Science.gov (United States)

    Liang, Meng; Kim, Min Hea; He, Qinghua Peter; Wang, Jin

    2013-09-01

    In this work we conducted the pseudo-continuous fermentation, i.e., continuous fermentation with cell retention, using Scheffersomyces stipitis, and studied its effect on ethanol tolerance of the strain. During the fermentation experiments, S. stipitis was adapted to a mild concentration of ethanol (20-26 g/L) for two weeks. Two substrates (glucose and xylose) were used in different fermentation experiments. After fermentation, various experiments were performed to evaluate the ethanol tolerance of adapted cells and unadapted cells. Compared to the unadapted cells, the viability of adapted cells increased by 8 folds with glucose as the carbon source and 6 folds with xylose as the carbon source following exposure to 60 g/L ethanol for 2 h. Improved ethanol tolerance of the adapted cells was also revealed in the effects of ethanol on plasma membrane permeability, extracellular alkalization and acidification. The mathematical modeling of cell leakage, extracellular alkalization and acidification revealed that cells cultured on glucose show better ethanol tolerance than cells cultured on xylose but the differences become smaller for adapted cells. The results show that pseudo-continuous fermentation can effectively improve cell's ethanol tolerance due to the environmental pressure during the fermentation process. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  14. Electrical Stimulation of Schwann Cells Promotes Sustained Increases in Neurite Outgrowth

    OpenAIRE

    Koppes, Abigail N.; Nordberg, Andrea L.; Paolillo, Gina M.; Goodsell, Nicole M.; Darwish, Haley A.; Zhang, Linxia; Thompson, Deanna M.

    2013-01-01

    Endogenous electric fields are instructive during embryogenesis by acting to direct cell migration, and postnatally, they can promote axonal growth after injury (McCaig 1991, Al-Majed 2000). However, the mechanisms for these changes are not well understood. Application of an appropriate electrical stimulus may increase the rate and success of nerve repair by directly promoting axonal growth. Previously, DC electrical stimulation at 50 mV/mm (1 mA, 8 h duration) was shown to promote neurite ou...

  15. Anti-regulatory T cells

    DEFF Research Database (Denmark)

    Andersen, Mads Hald

    2017-01-01

    responses to tumours or inhibiting autoimmunity development. However, recent studies report the discovery of self-reactive pro-inflammatory T cells—termed anti-regulatory T cells (anti-Tregs)—that target immune-suppressive cells. Thus, regulatory cells can now be defined as both cells that suppress immune...... reactions as well as effector cells that counteract the effects of suppressor cells and support immune reactions. Self-reactive anti-Tregs have been described that specifically recognize human leukocyte antigen-restricted epitopes derived from proteins that are normally expressed by regulatory immune cells......Our initial understanding of immune-regulatory cells was based on the discovery of suppressor cells that assure peripheral T-cell tolerance and promote immune homeostasis. Research has particularly focused on the importance of regulatory T cells (Tregs) for immune modulation, e.g. directing host...

  16. HNF1 alpha activates the aminopeptidase N promoter in intestinal (Caco-2) cells

    DEFF Research Database (Denmark)

    Olsen, Jørgen; Laustsen, Lotte; Troelsen, J

    1994-01-01

    The importance of HNF1 binding proteins for intestinal aminopeptidase N expression was investigated using the Caco-2 cell-line. Aminopeptidase N promoter activity in Caco-2 cells depends on the HNF1 element (positions -85 to -58) and co-transfection with an HNF1 alpha expression vector demonstrates...... a direct activation of the promoter by HNF1 alpha through this element. Electrophoretic mobility shift assays using nuclear extracts from Caco-2 cells show the presence of high amounts of HNF1 binding proteins irrespective of their state of differentiation....

  17. NCYM promotes calpain-mediated Myc-nick production in human MYCN-amplified neuroblastoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Shoji, Wataru [Division of Biochemistry and Innovative Cancer Therapeutics and Children' s Cancer Research Center, Chiba Cancer Center Research Institute, 666-2 Nitona, Chuo-ku, Chiba 260-8717 (Japan); Department of Pediatric Surgery, Graduate School of Medicine, Tohoku University, Sendai 980-8574 (Japan); Suenaga, Yusuke, E-mail: ysuenaga@chiba-cc.jp [Division of Biochemistry and Innovative Cancer Therapeutics and Children' s Cancer Research Center, Chiba Cancer Center Research Institute, 666-2 Nitona, Chuo-ku, Chiba 260-8717 (Japan); Cancer Genome Center, Chiba Cancer Center Research Institute, 666-2 Nitona, Chuo-ku, Chiba 260-8717 (Japan); Kaneko, Yoshiki; Islam, S.M. Rafiqul; Alagu, Jennifer [Division of Biochemistry and Innovative Cancer Therapeutics and Children' s Cancer Research Center, Chiba Cancer Center Research Institute, 666-2 Nitona, Chuo-ku, Chiba 260-8717 (Japan); Yokoi, Sana [Cancer Genome Center, Chiba Cancer Center Research Institute, 666-2 Nitona, Chuo-ku, Chiba 260-8717 (Japan); Nio, Masaki [Department of Pediatric Surgery, Graduate School of Medicine, Tohoku University, Sendai 980-8574 (Japan); Nakagawara, Akira, E-mail: nakagawara-a@koseikan.jp [Division of Biochemistry and Innovative Cancer Therapeutics and Children' s Cancer Research Center, Chiba Cancer Center Research Institute, 666-2 Nitona, Chuo-ku, Chiba 260-8717 (Japan)

    2015-06-05

    NCYM is a cis-antisense gene of MYCN and is amplified in human neuroblastomas. High NCYM expression is associated with poor prognoses, and the NCYM protein stabilizes MYCN to promote proliferation of neuroblastoma cells. However, the molecular mechanisms of NCYM in the regulation of cell survival have remained poorly characterized. Here we show that NCYM promotes cleavage of MYCN to produce the anti-apoptotic protein, Myc-nick, both in vitro and in vivo. NCYM and Myc-nick were induced at G2/M phase, and NCYM knockdown induced apoptotic cell death accompanied by Myc-nick downregulation. These results reveal a novel function of NCYM as a regulator of Myc-nick production in human neuroblastomas. - Highlights: • NCYM promotes cleavages of MYC and MYCN to produce Myc-nick in vitro. • NCYM increases Myc-nick production in MYCN-amplified neuroblastoma cells. • NCYM knockdown decreases Myc-nick production and induces apoptosis at G2/M phase.

  18. NCYM promotes calpain-mediated Myc-nick production in human MYCN-amplified neuroblastoma cells

    International Nuclear Information System (INIS)

    Shoji, Wataru; Suenaga, Yusuke; Kaneko, Yoshiki; Islam, S.M. Rafiqul; Alagu, Jennifer; Yokoi, Sana; Nio, Masaki; Nakagawara, Akira

    2015-01-01

    NCYM is a cis-antisense gene of MYCN and is amplified in human neuroblastomas. High NCYM expression is associated with poor prognoses, and the NCYM protein stabilizes MYCN to promote proliferation of neuroblastoma cells. However, the molecular mechanisms of NCYM in the regulation of cell survival have remained poorly characterized. Here we show that NCYM promotes cleavage of MYCN to produce the anti-apoptotic protein, Myc-nick, both in vitro and in vivo. NCYM and Myc-nick were induced at G2/M phase, and NCYM knockdown induced apoptotic cell death accompanied by Myc-nick downregulation. These results reveal a novel function of NCYM as a regulator of Myc-nick production in human neuroblastomas. - Highlights: • NCYM promotes cleavages of MYC and MYCN to produce Myc-nick in vitro. • NCYM increases Myc-nick production in MYCN-amplified neuroblastoma cells. • NCYM knockdown decreases Myc-nick production and induces apoptosis at G2/M phase

  19. Regulatory Myeloid Cells in Transplantation

    Science.gov (United States)

    Rosborough, Brian R.; Raïch-Regué, Dàlia; Turnquist, Heth R.; Thomson, Angus W.

    2013-01-01

    Regulatory myeloid cells (RMC) are emerging as novel targets for immunosuppressive (IS) agents and hold considerable promise as cellular therapeutic agents. Herein, we discuss the ability of regulatory macrophages (Mreg), regulatory dendritic cells (DCreg) and myeloid-derived suppressor cells (MDSC) to regulate alloimmunity, their potential as cellular therapeutic agents and the IS agents that target their function. We consider protocols for the generation of RMC and the selection of donor- or recipient-derived cells for adoptive cell therapy. Additionally, the issues of cell trafficking and antigen (Ag) specificity following RMC transfer are discussed. Improved understanding of the immunobiology of these cells has increased the possibility of moving RMC into the clinic to reduce the burden of current IS agents and promote Ag-specific tolerance. In the second half of this review, we discuss the influence of established and experimental IS agents on myeloid cell populations. IS agents believed historically to act primarily on T cell activation and proliferation are emerging as important regulators of RMC function. Better insights into the influence of IS agents on RMC will enhance our ability to develop cell therapy protocols to promote the function of these cells. Moreover, novel IS agents may be designed to target RMC in situ to promote Ag-specific immune regulation in transplantation and usher in a new era of immune modulation exploiting cells of myeloid origin. PMID:24092382

  20. Is Tolerance of Faiths Helpful in English School Policy? Reification, Complexity, and Values Education

    Science.gov (United States)

    Bowie, Robert

    2017-01-01

    Government policies for teachers and schools in England promote values including tolerance of faiths and beliefs alongside law keeping, democracy, and respect. Tolerance of faiths has been highlighted as a key value but complexities around tolerance make interpretations and applications of the policy difficult. Policy documents in this area are…

  1. Overcoming drug-tolerant cancer cell subpopulations showing AXL activation and epithelial–mesenchymal transition is critical in conquering ALK-positive lung cancer

    Science.gov (United States)

    Nakamichi, Shinji; Seike, Masahiro; Miyanaga, Akihiko; Chiba, Mika; Zou, Fenfei; Takahashi, Akiko; Ishikawa, Arimi; Kunugi, Shinobu; Noro, Rintaro; Kubota, Kaoru; Gemma, Akihiko

    2018-01-01

    Anaplastic lymphoma kinase tyrosine kinase inhibitors (ALK-TKIs) induce a dramatic response in non–small cell lung cancer (NSCLC) patients with the ALK fusion gene. However, acquired resistance to ALK-TKIs remains an inevitable problem. In this study, we aimed to discover novel therapeutic targets to conquer ALK-positive lung cancer. We established three types of ALK-TKI (crizotinib, alectinib and ceritinib)-resistant H2228 NSCLC cell lines by high exposure and stepwise methods. We found these cells showed a loss of ALK signaling, overexpressed AXL with epithelial-mesenchymal transition (EMT), and had cancer stem cell-like (CSC) properties, suggesting drug-tolerant cancer cell subpopulations. Similarly, we demonstrated that TGF-β1 treated H2228 cells also showed AXL overexpression with EMT features and ALK-TKI resistance. The AXL inhibitor, R428, or HSP90 inhibitor, ganetespib, were effective in reversing ALK-TKI resistance and EMT changes in both ALK-TKI-resistant and TGF-β1-exposed H2228 cells. Tumor volumes of xenograft mice implanted with established H2228-ceritinib-resistant (H2228-CER) cells were significantly reduced after treatment with ganetespib, or ganetespib in combination with ceritinib. Some ALK-positive NSCLC patients with AXL overexpression showed a poorer response to crizotinib therapy than patients with a low expression of AXL. ALK signaling-independent AXL overexpressed in drug-tolerant cancer cell subpopulations with EMT and CSC features may be commonly involved commonly involved in intrinsic and acquired resistance to ALK-TKIs. This suggests AXL and HSP90 inhibitors may be promising therapeutic drugs to overcome drug-tolerant cancer cell subpopulations in ALK-positive NSCLC patients for the reason that ALK-positive NSCLC cells do not live through ALK-TKI therapy. PMID:29930762

  2. Novel mitochondria-targeted heat-soluble proteins identified in the anhydrobiotic Tardigrade improve osmotic tolerance of human cells.

    Directory of Open Access Journals (Sweden)

    Sae Tanaka

    Full Text Available Tardigrades are able to tolerate almost complete dehydration through transition to a metabolically inactive state, called "anhydrobiosis". Late Embryogenesis Abundant (LEA proteins are heat-soluble proteins involved in the desiccation tolerance of many anhydrobiotic organisms. Tardigrades, Ramazzottius varieornatus, however, express predominantly tardigrade-unique heat-soluble proteins: CAHS (Cytoplasmic Abundant Heat Soluble and SAHS (Secretory Abundant Heat Soluble proteins, which are secreted or localized in most intracellular compartments, except the mitochondria. Although mitochondrial integrity is crucial to ensure cellular survival, protective molecules for mitochondria have remained elusive. Here, we identified two novel mitochondrial heat-soluble proteins, RvLEAM and MAHS (Mitochondrial Abundant Heat Soluble, as potent mitochondrial protectants from Ramazzottius varieornatus. RvLEAM is a group3 LEA protein and immunohistochemistry confirmed its mitochondrial localization in tardigrade cells. MAHS-green fluorescent protein fusion protein localized in human mitochondria and was heat-soluble in vitro, though no sequence similarity with other known proteins was found, and one region was conserved among tardigrades. Furthermore, we demonstrated that RvLEAM protein as well as MAHS protein improved the hyperosmotic tolerance of human cells. The findings of the present study revealed that tardigrade mitochondria contain at least two types of heat-soluble proteins that might have protective roles in water-deficient environments.

  3. Persistence and drug tolerance in pathogenic yeast

    DEFF Research Database (Denmark)

    Bojsen, Rasmus Kenneth; Regenberg, Birgitte; Folkesson, Sven Anders

    2017-01-01

    In this review, we briefly summarize the current understanding of how fungal pathogens can persist antifungal treatment without heritable resistance mutations by forming tolerant persister cells. Fungal infections tolerant to antifungal treatment have become a major medical problem. One mechanism...

  4. Human Nanog pseudogene8 promotes the proliferation of gastrointestinal cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Uchino, Keita, E-mail: uchino13@intmed1.med.kyushu-u.ac.jp [Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Hirano, Gen [Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Hirahashi, Minako [Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Isobe, Taichi; Shirakawa, Tsuyoshi; Kusaba, Hitoshi; Baba, Eishi [Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Tsuneyoshi, Masazumi [Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Akashi, Koichi [Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan)

    2012-09-10

    There is emerging evidence that human solid tumor cells originate from cancer stem cells (CSCs). In cancer cell lines, tumor-initiating CSCs are mainly found in the side population (SP) that has the capacity to extrude dyes such as Hoechst 33342. We found that Nanog is expressed specifically in SP cells of human gastrointestinal (GI) cancer cells. Nucleotide sequencing revealed that NanogP8 but not Nanog was expressed in GI cancer cells. Transfection of NanogP8 into GI cancer cell lines promoted cell proliferation, while its inhibition by anti-Nanog siRNA suppressed the proliferation. Immunohistochemical staining of primary GI cancer tissues revealed NanogP8 protein to be strongly expressed in 3 out of 60 cases. In these cases, NanogP8 was found especially in an infiltrative part of the tumor, in proliferating cells with Ki67 expression. These data suggest that NanogP8 is involved in GI cancer development in a fraction of patients, in whom it presumably acts by supporting CSC proliferation. -- Highlights: Black-Right-Pointing-Pointer Nanog maintains pluripotency by regulating embryonic stem cells differentiation. Black-Right-Pointing-Pointer Nanog is expressed in cancer stem cells of human gastrointestinal cancer cells. Black-Right-Pointing-Pointer Nucleotide sequencing revealed that Nanog pseudogene8 but not Nanog was expressed. Black-Right-Pointing-Pointer Nanog pseudogene8 promotes cancer stem cells proliferation. Black-Right-Pointing-Pointer Nanog pseudogene8 is involved in gastrointestinal cancer development.

  5. Tolerance to MHC class II disparate allografts through genetic modification of bone marrow

    Science.gov (United States)

    Jindra, Peter T.; Tripathi, Sudipta; Tian, Chaorui; Iacomini, John; Bagley, Jessamyn

    2012-01-01

    Induction of molecular chimerism through genetic modification of bone marrow is a powerful tool for the induction of tolerance. Here we demonstrate for the first time that expression of an allogeneic MHC class II gene in autologous bone marrow cells, resulting in a state of molecular chimerism, induces tolerance to MHC class II mismatched skin grafts, a stringent test of transplant tolerance. Reconstitution of recipients with syngeneic bone marrow transduced with retrovirus encoding H-2I-Ab (I-Ab) resulted the long-term expression of the retroviral gene product on the surface of MHC class II-expressing bone marrow derived cell types. Mechanistically, tolerance was maintained by the presence of regulatory T cells, which prevented proliferation and cytokine production by alloreactive host T cells. Thus, the introduction of MHC class II genes into bone marrow derived cells through genetic engineering results in tolerance. These results have the potential to extend the clinical applicability of molecular chimerism for tolerance induction. PMID:22833118

  6. Promoter for the late gene encoding Vp5 of herpes simplex virus type 1 is recognized by cell extracts derived from uninfected cells

    International Nuclear Information System (INIS)

    Chisholm, G.E.; Summers, W.C.

    1986-01-01

    The ability of whole-cell extracts from unidentified HeLa cells to recognize the promoter for the herpes simplex virus type 1 late gene encoding the major capsid protein Vp5 was investigated by using both in vitro transcriptional and S1 nuclease protection analysis. This gene promoter was recognized by the cell extracts and produced abundant amounts of transcript in the absence of any other virus-encoded factors. This transcript was shown to arise, in vitro, from specific initiation at or very near the physiological mRNA start site. Thus, it appears that cell extracts from uninfected HeLa cells can efficiently recognize both early- and late-gene promoters

  7. Rac1 acts in conjunction with Nedd4 and dishevelled-1 to promote maturation of cell-cell contacts

    NARCIS (Netherlands)

    M. Nethe (Micha); B.J. de Kreuk (Bart-Jan); D.V.F. Tauriello (Daniele); E.C. Anthony (Eloise); B. Snoek (Barbara); T. Stumpel (Thomas); M. Salinas; K. Maurice (Karelle); D. Geerts (Dirk); A.M. Deelder (André); P. Hensbergen (Paul); P.L. Hordijk (Peter )

    2012-01-01

    textabstractThe Rho-GTPase Rac1 promotes actin polymerization and membrane protrusion that mediate initial contact and subsequent maturation of cell-cell junctions. Here we report that Rac1 associates with the ubiquitin-protein ligase neural precursor cell expressed developmentally down-regulated 4

  8. An Alu-like RNA promotes cell differentiation and reduces malignancy of human neuroblastoma cells.

    Science.gov (United States)

    Castelnuovo, Manuele; Massone, Sara; Tasso, Roberta; Fiorino, Gloria; Gatti, Monica; Robello, Mauro; Gatta, Elena; Berger, Audrey; Strub, Katharina; Florio, Tullio; Dieci, Giorgio; Cancedda, Ranieri; Pagano, Aldo

    2010-10-01

    Neuroblastoma (NB) is a pediatric cancer characterized by remarkable cell heterogeneity within the tumor nodules. Here, we demonstrate that the synthesis of a pol III-transcribed noncoding (nc) RNA (NDM29) strongly restricts NB development by promoting cell differentiation, a drop of malignancy processes, and a dramatic reduction of the tumor initiating cell (TIC) fraction in the NB cell population. Notably, the overexpression of NDM29 also confers to malignant NB cells an unpredicted susceptibility to the effects of antiblastic drugs used in NB therapy. Altogether, these results suggest the induction of NDM29 expression as possible treatment to increase cancer cells vulnerability to therapeutics and the measure of its synthesis in NB explants as prognostic factor of this cancer type.

  9. Genistein promotes DNA demethylation of the steroidogenic factor 1 (SF-1) promoter in endometrial stromal cells

    International Nuclear Information System (INIS)

    Matsukura, Hiroshi; Aisaki, Ken-ichi; Igarashi, Katsuhide; Matsushima, Yuko; Kanno, Jun; Muramatsu, Masaaki; Sudo, Katsuko; Sato, Noriko

    2011-01-01

    Highlights: → Genistein (GEN) is a phytoestrogen found in soy products. → GEN demethylated/unsilenced the steroidogenic factor 1 gene in endometrial tissue. → GEN thus altered mRNA expression in uteri of ovariectomized (OVX) mice. → A high-resolution melting assay was used to screen for epigenetic change. → We isolated an endometrial cell clone that was epigenetically modulated by GEN. -- Abstract: It has recently been demonstrated that genistein (GEN), a phytoestrogen in soy products, is an epigenetic modulator in various types of cells; but its effect on endometrium has not yet been determined. We investigated the effects of GEN on mouse uterine cells, in vivo and in vitro. Oral administration of GEN for 1 week induced mild proliferation of the endometrium in ovariectomized (OVX) mice, which was accompanied by the induction of steroidogenic factor 1 (SF-1) gene expression. GEN administration induced demethylation of multiple CpG sites in the SF-1 promoter; these sites are extensively methylated and thus silenced in normal endometrium. The GEN-mediated promoter demethylation occurred predominantly on the luminal side, as opposed to myometrium side, indicating that the epigenetic change was mainly shown in regenerated cells. Primary cultures of endometrial stromal cell colonies were screened for GEN-mediated alterations of DNA methylation by a high-resolution melting (HRM) method. One out of 20 colony-forming cell clones showed GEN-induced demethylation of SF-1. This clone exhibited a high proliferation capacity with continuous colony formation activity through multiple serial clonings. We propose that only a portion of endometrial cells are capable of receiving epigenetic modulation by GEN.

  10. Genistein promotes DNA demethylation of the steroidogenic factor 1 (SF-1) promoter in endometrial stromal cells

    Energy Technology Data Exchange (ETDEWEB)

    Matsukura, Hiroshi, E-mail: hmatsukura.epi@mri.tmd.ac.jp [Department of Molecular Epidemiology, Medical Research Institute, Tokyo Medical and Dental University, 2-3-10 Kanda-surugadai, Chiyoda-ku, Tokyo 101-0062 (Japan); Aisaki, Ken-ichi; Igarashi, Katsuhide; Matsushima, Yuko; Kanno, Jun [Division of Cellular and Molecular Toxicology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501 (Japan); Muramatsu, Masaaki [Department of Molecular Epidemiology, Medical Research Institute, Tokyo Medical and Dental University, 2-3-10 Kanda-surugadai, Chiyoda-ku, Tokyo 101-0062 (Japan); Sudo, Katsuko [Department of Molecular Epidemiology, Medical Research Institute, Tokyo Medical and Dental University, 2-3-10 Kanda-surugadai, Chiyoda-ku, Tokyo 101-0062 (Japan); Animal Research Center, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo 160-8402 (Japan); Sato, Noriko, E-mail: nsato.epi@tmd.ac.jp [Department of Molecular Epidemiology, Medical Research Institute, Tokyo Medical and Dental University, 2-3-10 Kanda-surugadai, Chiyoda-ku, Tokyo 101-0062 (Japan)

    2011-08-26

    Highlights: {yields} Genistein (GEN) is a phytoestrogen found in soy products. {yields} GEN demethylated/unsilenced the steroidogenic factor 1 gene in endometrial tissue. {yields} GEN thus altered mRNA expression in uteri of ovariectomized (OVX) mice. {yields} A high-resolution melting assay was used to screen for epigenetic change. {yields} We isolated an endometrial cell clone that was epigenetically modulated by GEN. -- Abstract: It has recently been demonstrated that genistein (GEN), a phytoestrogen in soy products, is an epigenetic modulator in various types of cells; but its effect on endometrium has not yet been determined. We investigated the effects of GEN on mouse uterine cells, in vivo and in vitro. Oral administration of GEN for 1 week induced mild proliferation of the endometrium in ovariectomized (OVX) mice, which was accompanied by the induction of steroidogenic factor 1 (SF-1) gene expression. GEN administration induced demethylation of multiple CpG sites in the SF-1 promoter; these sites are extensively methylated and thus silenced in normal endometrium. The GEN-mediated promoter demethylation occurred predominantly on the luminal side, as opposed to myometrium side, indicating that the epigenetic change was mainly shown in regenerated cells. Primary cultures of endometrial stromal cell colonies were screened for GEN-mediated alterations of DNA methylation by a high-resolution melting (HRM) method. One out of 20 colony-forming cell clones showed GEN-induced demethylation of SF-1. This clone exhibited a high proliferation capacity with continuous colony formation activity through multiple serial clonings. We propose that only a portion of endometrial cells are capable of receiving epigenetic modulation by GEN.

  11. Prioritized Expression of BDH2 under Bulk Translational Repression and Its Contribution to Tolerance to Severe Vanillin Stress in Saccharomyces cerevisiae.

    Science.gov (United States)

    Ishida, Yoko; Nguyen, Trinh T M; Kitajima, Sakihito; Izawa, Shingo

    2016-01-01

    Vanillin is a potent fermentation inhibitor derived from the lignocellulosic biomass in biofuel production, and high concentrations of vanillin result in the pronounced repression of bulk translation in Saccharomyces cerevisiae. Studies on genes that are efficiently translated even in the presence of high concentrations of vanillin will be useful for improving yeast vanillin tolerance and fermentation efficiency. The BDH1 and BDH2 genes encode putative medium-chain alcohol dehydrogenase/reductases and their amino acid sequences are very similar to each other. Although BDH2 was previously suggested to be involved in vanillin tolerance, it has yet to be clarified whether Bdh1/Bdh2 actually contribute to vanillin tolerance and reductions in vanillin. Therefore, we herein investigated the effects of Bdh1 and Bdh2 on vanillin tolerance. bdh2Δ cells exhibited hypersensitivity to vanillin and slower reductions in vanillin than wild-type cells and bdh1Δ cells. Additionally, the overexpression of the BDH2 gene improved yeast tolerance to vanillin more efficiently than that of BDH1. Only BDH2 mRNA was efficiently translated under severe vanillin stress, however, both BDH genes were transcriptionally up-regulated. These results reveal the importance of Bdh2 in vanillin detoxification and confirm the preferential translation of the BDH2 gene in the presence of high concentrations of vanillin. The BDH2 promoter also enabled the expression of non-native genes under severe vanillin stress and furfural stress, suggesting its availability to improve of the efficiency of bioethanol production through modifications in gene expression in the presence of fermentation inhibitors.

  12. Promoter de-methylation of cyclin D2 by sulforaphane in prostate cancer cells

    Directory of Open Access Journals (Sweden)

    Hsu Anna

    2011-10-01

    Full Text Available Abstract Sulforaphane (SFN, an isothiocyanate derived from cruciferous vegetables, induces potent anti-proliferative effects in prostate cancer cells. One mechanism that may contribute to the anti-proliferative effects of SFN is the modulation of epigenetic marks, such as inhibition of histone deacetylase (HDAC enzymes. However, the effects of SFN on other common epigenetic marks such as DNA methylation are understudied. Promoter hyper-methylation of cyclin D2, a major regulator of cell cycle, is correlated with prostate cancer progression, and restoration of cyclin D2 expression exerts anti-proliferative effects on LnCap prostate cancer cells. Our study aimed to investigate the effects of SFN on DNA methylation status of cyclin D2 promoter, and how alteration in promoter methylation impacts cyclin D2 gene expression in LnCap cells. We found that SFN significantly decreased the expression of DNA methyltransferases (DNMTs, especially DNMT1 and DNMT3b. Furthermore, SFN significantly decreased methylation in cyclin D2 promoter regions containing c-Myc and multiple Sp1 binding sites. Reduced methlyation of cyclin D2 promoter corresponded to an increase in cyclin D2 transcript levels, suggesting that SFN may de-repress methylation-silenced cyclin D2 by impacting epigenetic pathways. Our results demonstrated the ability of SFN to epigenetically modulate cyclin D2 expression, and provide novel insights into the mechanisms by which SFN may regulate gene expression as a prostate cancer chemopreventive agent.

  13. Sox2 promotes survival of satellite glial cells in vitro

    International Nuclear Information System (INIS)

    Koike, Taro; Wakabayashi, Taketoshi; Mori, Tetsuji; Hirahara, Yukie; Yamada, Hisao

    2015-01-01

    Sox2 is a transcriptional factor expressed in neural stem cells. It is known that Sox2 regulates cell differentiation, proliferation and survival of the neural stem cells. Our previous study showed that Sox2 is expressed in all satellite glial cells of the adult rat dorsal root ganglion. In this study, to examine the role of Sox2 in satellite glial cells, we establish a satellite glial cell-enriched culture system. Our culture method succeeded in harvesting satellite glial cells with the somata of neurons in the dorsal root ganglion. Using this culture system, Sox2 was downregulated by siRNA against Sox2. The knockdown of Sox2 downregulated ErbB2 and ErbB3 mRNA at 2 and 4 days after siRNA treatment. MAPK phosphorylation, downstream of ErbB, was also inhibited by Sox2 knockdown. Because ErbB2 and ErbB3 are receptors that support the survival of glial cells in the peripheral nervous system, apoptotic cells were also counted. TUNEL-positive cells increased at 5 days after siRNA treatment. These results suggest that Sox2 promotes satellite glial cell survival through the MAPK pathway via ErbB receptors. - Highlights: • We established satellite glial cell culture system. • Function of Sox2 in satellite glial cell was examined using siRNA. • Sox2 knockdown downregulated expression level of ErbB2 and ErbB3 mRNA. • Sox2 knockdown increased apoptotic satellite glial cell. • Sox2 promotes satellite glial cell survival through ErbB signaling

  14. Sox2 promotes survival of satellite glial cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Koike, Taro, E-mail: koiket@hirakata.kmu.ac.jp; Wakabayashi, Taketoshi; Mori, Tetsuji; Hirahara, Yukie; Yamada, Hisao

    2015-08-14

    Sox2 is a transcriptional factor expressed in neural stem cells. It is known that Sox2 regulates cell differentiation, proliferation and survival of the neural stem cells. Our previous study showed that Sox2 is expressed in all satellite glial cells of the adult rat dorsal root ganglion. In this study, to examine the role of Sox2 in satellite glial cells, we establish a satellite glial cell-enriched culture system. Our culture method succeeded in harvesting satellite glial cells with the somata of neurons in the dorsal root ganglion. Using this culture system, Sox2 was downregulated by siRNA against Sox2. The knockdown of Sox2 downregulated ErbB2 and ErbB3 mRNA at 2 and 4 days after siRNA treatment. MAPK phosphorylation, downstream of ErbB, was also inhibited by Sox2 knockdown. Because ErbB2 and ErbB3 are receptors that support the survival of glial cells in the peripheral nervous system, apoptotic cells were also counted. TUNEL-positive cells increased at 5 days after siRNA treatment. These results suggest that Sox2 promotes satellite glial cell survival through the MAPK pathway via ErbB receptors. - Highlights: • We established satellite glial cell culture system. • Function of Sox2 in satellite glial cell was examined using siRNA. • Sox2 knockdown downregulated expression level of ErbB2 and ErbB3 mRNA. • Sox2 knockdown increased apoptotic satellite glial cell. • Sox2 promotes satellite glial cell survival through ErbB signaling.

  15. Potato Annexin STANN1 Promotes Drought Tolerance and Mitigates Light Stress in Transgenic Solanum tuberosum L. Plants

    Science.gov (United States)

    Szalonek, Michal; Sierpien, Barbara; Rymaszewski, Wojciech; Gieczewska, Katarzyna; Garstka, Maciej; Lichocka, Malgorzata; Sass, Laszlo; Paul, Kenny; Vass, Imre; Vankova, Radomira; Dobrev, Peter; Szczesny, Pawel; Marczewski, Waldemar; Krusiewicz, Dominika; Strzelczyk-Zyta, Danuta; Hennig, Jacek; Konopka-Postupolska, Dorota

    2015-01-01

    Annexins are a family of calcium- and membrane-binding proteins that are important for plant tolerance to adverse environmental conditions. Annexins function to counteract oxidative stress, maintain cell redox homeostasis, and enhance drought tolerance. In the present study, an endogenous annexin, STANN1, was overexpressed to determine whether crop yields could be improved in potato (Solanum tuberosum L.) during drought. Nine potential potato annexins were identified and their expression characterized in response to drought treatment. STANN1 mRNA was constitutively expressed at a high level and drought treatment strongly increased transcription levels. Therefore, STANN1 was selected for overexpression analysis. Under drought conditions, transgenic potato plants ectopically expressing STANN1 were more tolerant to water deficit in the root zone, preserved more water in green tissues, maintained chloroplast functions, and had higher accumulation of chlorophyll b and xanthophylls (especially zeaxanthin) than wild type (WT). Drought-induced reductions in the maximum efficiency and the electron transport rate of photosystem II (PSII), as well as the quantum yield of photosynthesis, were less pronounced in transgenic plants overexpressing STANN1 than in the WT. This conferred more efficient non-photochemical energy dissipation in the outer antennae of PSII and probably more efficient protection of reaction centers against photooxidative damage in transgenic plants under drought conditions. Consequently, these plants were able to maintain effective photosynthesis during drought, which resulted in greater productivity than WT plants despite water scarcity. Although the mechanisms underlying this stress protection are not yet clear, annexin-mediated photoprotection is probably linked to protection against light-induced oxidative stress. PMID:26172952

  16. Potato Annexin STANN1 Promotes Drought Tolerance and Mitigates Light Stress in Transgenic Solanum tuberosum L. Plants.

    Science.gov (United States)

    Szalonek, Michal; Sierpien, Barbara; Rymaszewski, Wojciech; Gieczewska, Katarzyna; Garstka, Maciej; Lichocka, Malgorzata; Sass, Laszlo; Paul, Kenny; Vass, Imre; Vankova, Radomira; Dobrev, Peter; Szczesny, Pawel; Marczewski, Waldemar; Krusiewicz, Dominika; Strzelczyk-Zyta, Danuta; Hennig, Jacek; Konopka-Postupolska, Dorota

    2015-01-01

    Annexins are a family of calcium- and membrane-binding proteins that are important for plant tolerance to adverse environmental conditions. Annexins function to counteract oxidative stress, maintain cell redox homeostasis, and enhance drought tolerance. In the present study, an endogenous annexin, STANN1, was overexpressed to determine whether crop yields could be improved in potato (Solanum tuberosum L.) during drought. Nine potential potato annexins were identified and their expression characterized in response to drought treatment. STANN1 mRNA was constitutively expressed at a high level and drought treatment strongly increased transcription levels. Therefore, STANN1 was selected for overexpression analysis. Under drought conditions, transgenic potato plants ectopically expressing STANN1 were more tolerant to water deficit in the root zone, preserved more water in green tissues, maintained chloroplast functions, and had higher accumulation of chlorophyll b and xanthophylls (especially zeaxanthin) than wild type (WT). Drought-induced reductions in the maximum efficiency and the electron transport rate of photosystem II (PSII), as well as the quantum yield of photosynthesis, were less pronounced in transgenic plants overexpressing STANN1 than in the WT. This conferred more efficient non-photochemical energy dissipation in the outer antennae of PSII and probably more efficient protection of reaction centers against photooxidative damage in transgenic plants under drought conditions. Consequently, these plants were able to maintain effective photosynthesis during drought, which resulted in greater productivity than WT plants despite water scarcity. Although the mechanisms underlying this stress protection are not yet clear, annexin-mediated photoprotection is probably linked to protection against light-induced oxidative stress.

  17. Potato Annexin STANN1 Promotes Drought Tolerance and Mitigates Light Stress in Transgenic Solanum tuberosum L. Plants.

    Directory of Open Access Journals (Sweden)

    Michal Szalonek

    Full Text Available Annexins are a family of calcium- and membrane-binding proteins that are important for plant tolerance to adverse environmental conditions. Annexins function to counteract oxidative stress, maintain cell redox homeostasis, and enhance drought tolerance. In the present study, an endogenous annexin, STANN1, was overexpressed to determine whether crop yields could be improved in potato (Solanum tuberosum L. during drought. Nine potential potato annexins were identified and their expression characterized in response to drought treatment. STANN1 mRNA was constitutively expressed at a high level and drought treatment strongly increased transcription levels. Therefore, STANN1 was selected for overexpression analysis. Under drought conditions, transgenic potato plants ectopically expressing STANN1 were more tolerant to water deficit in the root zone, preserved more water in green tissues, maintained chloroplast functions, and had higher accumulation of chlorophyll b and xanthophylls (especially zeaxanthin than wild type (WT. Drought-induced reductions in the maximum efficiency and the electron transport rate of photosystem II (PSII, as well as the quantum yield of photosynthesis, were less pronounced in transgenic plants overexpressing STANN1 than in the WT. This conferred more efficient non-photochemical energy dissipation in the outer antennae of PSII and probably more efficient protection of reaction centers against photooxidative damage in transgenic plants under drought conditions. Consequently, these plants were able to maintain effective photosynthesis during drought, which resulted in greater productivity than WT plants despite water scarcity. Although the mechanisms underlying this stress protection are not yet clear, annexin-mediated photoprotection is probably linked to protection against light-induced oxidative stress.

  18. Tolerance induction to cytoplasmic beta-galactosidase by hepatic AAV gene transfer: implications for antigen presentation and immunotoxicity.

    Directory of Open Access Journals (Sweden)

    Ashley T Martino

    2009-08-01

    Full Text Available Hepatic gene transfer, in particular using adeno-associated viral (AAV vectors, has been shown to induce immune tolerance to several protein antigens. This approach has been exploited in animal models of inherited protein deficiency for systemic delivery of therapeutic proteins. Adequate levels of transgene expression in hepatocytes induce a suppressive T cell response, thereby promoting immune tolerance. This study addresses the question of whether AAV gene transfer can induce tolerance to a cytoplasmic protein.AAV-2 vector-mediated hepatic gene transfer for expression of cytoplasmic beta-galactosidase (beta-gal was performed in immune competent mice, followed by a secondary beta-gal gene transfer with E1/E3-deleted adenoviral Ad-LacZ vector to provoke a severe immunotoxic response. Transgene expression from the AAV-2 vector in approximately 2% of hepatocytes almost completely protected from inflammatory T cell responses against beta-gal, eliminated antibody formation, and significantly reduced adenovirus-induced hepatotoxicity. Consequently, approximately 10% of hepatocytes continued to express beta-gal 45 days after secondary Ad-LacZ gene transfer, a time point when control mice had lost all Ad-LacZ derived expression. Suppression of inflammatory T cell infiltration in the liver and liver damage was linked to specific transgene expression and was not seen for secondary gene transfer with Ad-GFP. A combination of adoptive transfer studies and flow cytometric analyses demonstrated induction of Treg that actively suppressed CD8(+ T cell responses to beta-gal and that was amplified in liver and spleen upon secondary Ad-LacZ gene transfer.These data demonstrate that tolerance induction by hepatic AAV gene transfer does not require systemic delivery of the transgene product and that expression of a cytoplasmic neo-antigen in few hepatocytes can induce Treg and provide long-term suppression of inflammatory responses and immunotoxicity.

  19. Neural stem cells promote nerve regeneration through IL12-induced Schwann cell differentiation.

    Science.gov (United States)

    Lee, Don-Ching; Chen, Jong-Hang; Hsu, Tai-Yu; Chang, Li-Hsun; Chang, Hsu; Chi, Ya-Hui; Chiu, Ing-Ming

    2017-03-01

    Regeneration of injured peripheral nerves is a slow, complicated process that could be improved by implantation of neural stem cells (NSCs) or nerve conduit. Implantation of NSCs along with conduits promotes the regeneration of damaged nerve, likely because (i) conduit supports and guides axonal growth from one nerve stump to the other, while preventing fibrous tissue ingrowth and retaining neurotrophic factors; and (ii) implanted NSCs differentiate into Schwann cells and maintain a growth factor enriched microenvironment, which promotes nerve regeneration. In this study, we identified IL12p80 (homodimer of IL12p40) in the cell extracts of implanted nerve conduit combined with NSCs by using protein antibody array and Western blotting. Levels of IL12p80 in these conduits are 1.6-fold higher than those in conduits without NSCs. In the sciatic nerve injury mouse model, implantation of NSCs combined with nerve conduit and IL12p80 improves motor recovery and increases the diameter up to 4.5-fold, at the medial site of the regenerated nerve. In vitro study further revealed that IL12p80 stimulates the Schwann cell differentiation of mouse NSCs through the phosphorylation of signal transducer and activator of transcription 3 (Stat3). These results suggest that IL12p80 can trigger Schwann cell differentiation of mouse NSCs through Stat3 phosphorylation and enhance the functional recovery and the diameter of regenerated nerves in a mouse sciatic nerve injury model. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Mechanosensation Dynamically Coordinates Polar Growth and Cell Wall Assembly to Promote Cell Survival.

    Science.gov (United States)

    Davì, Valeria; Tanimoto, Hirokazu; Ershov, Dmitry; Haupt, Armin; De Belly, Henry; Le Borgne, Rémi; Couturier, Etienne; Boudaoud, Arezki; Minc, Nicolas

    2018-04-23

    How growing cells cope with size expansion while ensuring mechanical integrity is not known. In walled cells, such as those of microbes and plants, growth and viability are both supported by a thin and rigid encasing cell wall (CW). We deciphered the dynamic mechanisms controlling wall surface assembly during cell growth, using a sub-resolution microscopy approach to monitor CW thickness in live rod-shaped fission yeast cells. We found that polar cell growth yielded wall thinning and that thickness negatively influenced growth. Thickness at growing tips exhibited a fluctuating behavior with thickening phases followed by thinning phases, indicative of a delayed feedback promoting thickness homeostasis. This feedback was mediated by mechanosensing through the CW integrity pathway, which probes strain in the wall to adjust synthase localization and activity to surface growth. Mutants defective in thickness homeostasis lysed by rupturing the wall, demonstrating its pivotal role for walled cell survival. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. The flavoprotein Tah18-dependent NO synthesis confers high-temperature stress tolerance on yeast cells

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Akira; Kawahara, Nobuhiro [Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192 (Japan); Takagi, Hiroshi, E-mail: hiro@bs.naist.jp [Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192 (Japan)

    2013-01-04

    Highlights: Black-Right-Pointing-Pointer NO is produced from L-arginine in response to elevated temperature in yeast. Black-Right-Pointing-Pointer Tah18 was first identified as the yeast protein involved in NO synthesis. Black-Right-Pointing-Pointer Tah18-dependent NO synthesis confers tolerance to high-temperature on yeast cells. -- Abstract: Nitric oxide (NO) is a ubiquitous signaling molecule involved in the regulation of a large number of cellular functions. In the unicellular eukaryote yeast, NO may be involved in stress response pathways, but its role is poorly understood due to the lack of mammalian NO synthase (NOS) orthologues. Previously, we have proposed the oxidative stress-induced L-arginine synthesis and its physiological role under stress conditions in yeast Saccharomyces cerevisiae. Here, our experimental results indicated that increased conversion of L-proline into L-arginine led to NO production in response to elevated temperature. We also showed that the flavoprotein Tah18, which was previously reported to transfer electrons to the Fe-S cluster protein Dre2, was involved in NO synthesis in yeast. Gene knockdown analysis demonstrated that Tah18-dependent NO synthesis confers high-temperature stress tolerance on yeast cells. As it appears that such a unique cell protection mechanism is specific to yeasts and fungi, it represents a promising target for antifungal activity.

  2. Molecular Evolution of Two Distinct dmrt1 Promoters for Germ and Somatic Cells in Vertebrate Gonads.

    Science.gov (United States)

    Mawaribuchi, Shuuji; Musashijima, Masato; Wada, Mikako; Izutsu, Yumi; Kurakata, Erina; Park, Min Kyun; Takamatsu, Nobuhiko; Ito, Michihiko

    2017-03-01

    The transcription factor DMRT1 has important functions in two distinct processes, somatic-cell masculinization and germ-cell development in mammals. However, it is unknown whether the functions are conserved during evolution, and what mechanism underlies its expression in the two cell lineages. Our analysis of the Xenopus laevis and Silurana tropicalis dmrt1 genes indicated the presence of two distinct promoters: one upstream of the noncoding first exon (ncEx1), and one within the first intron. In contrast, only the ncEx1-upstream promoter was detected in the dmrt1 gene of the agnathan sand lamprey, which expressed dmrt1 exclusively in the germ cells. In X. laevis, the ncEx1- and exon 2-upstream promoters were predominantly used for germ-cell and somatic-cell transcription, respectively. Importantly, knockdown of the ncEx1-containing transcript led to reduced germ-cell numbers in X. laevis gonads. Intriguingly, two genetically female individuals carrying the knockdown construct developed testicles. Analysis of the reptilian leopard gecko dmrt1 revealed the absence of ncEx1. We propose that dmrt1 regulated germ-cell development in the vertebrate ancestor, then acquired another promoter in its first intron to regulate somatic-cell masculinization during gnathostome evolution. In the common ancestor of reptiles and mammals, only one promoter got function for both the two cell lineages, accompanied with the loss of ncEx1. In addition, we found a conserved noncoding sequence (CNS) in the dmrt1 5'-flanking regions only among amniote species, and two CNSs in the introns among most vertebrates except for agnathans. Finally, we discuss relationships between these CNSs and the promoters of dmrt1 during vertebrate evolution. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Fascin overexpression promotes neoplastic progression in oral squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Alam Hunain

    2012-01-01

    Full Text Available Abstract Background Fascin is a globular actin cross-linking protein, which plays a major role in forming parallel actin bundles in cell protrusions and is found to be associated with tumor cell invasion and metastasis in various type of cancers including oral squamous cell carcinoma (OSCC. Previously, we have demonstrated that fascin regulates actin polymerization and thereby promotes cell motility in K8-depleted OSCC cells. In the present study we have investigated the role of fascin in tumor progression of OSCC. Methods To understand the role of fascin in OSCC development and/or progression, fascin was overexpressed along with vector control in OSCC derived cells AW13516. The phenotype was studied using wound healing, Boyden chamber, cell adhesion, Hanging drop, soft agar and tumorigenicity assays. Further, fascin expression was examined in human OSCC samples (N = 131 using immunohistochemistry and level of its expression was correlated with clinico-pathological parameters of the patients. Results Fascin overexpression in OSCC derived cells led to significant increase in cell migration, cell invasion and MMP-2 activity. In addition these cells demonstrated increased levels of phosphorylated AKT, ERK1/2 and JNK1/2. Our in vitro results were consistent with correlative studies of fascin expression with the clinico-pathological parameters of the OSCC patients. Fascin expression in OSCC showed statistically significant correlation with increased tumor stage (P = 0.041, increased lymph node metastasis (P = 0.001, less differentiation (P = 0.005, increased recurrence (P = 0.038 and shorter survival (P = 0.004 of the patients. Conclusion In conclusion, our results indicate that fascin promotes tumor progression and activates AKT and MAPK pathways in OSCC-derived cells. Further, our correlative studies of fascin expression in OSCC with clinico-pathological parameters of the patients indicate that fascin may prove to be useful in prognostication and

  4. Fascin overexpression promotes neoplastic progression in oral squamous cell carcinoma

    International Nuclear Information System (INIS)

    Alam, Hunain; Kannanl, Sadhna; Gude, Rajiv; Kane, Shubhada; Dalal, Sorab N; Vaidya, Milind M; Bhate, Amruta V; Gangadaran, Prakash; Sawant, Sharda S; Salot, Shimul; Sehgal, Lalit; Dange, Prerana P; Chaukar, Devendra A; D'cruz, Anil K

    2012-01-01

    Fascin is a globular actin cross-linking protein, which plays a major role in forming parallel actin bundles in cell protrusions and is found to be associated with tumor cell invasion and metastasis in various type of cancers including oral squamous cell carcinoma (OSCC). Previously, we have demonstrated that fascin regulates actin polymerization and thereby promotes cell motility in K8-depleted OSCC cells. In the present study we have investigated the role of fascin in tumor progression of OSCC. To understand the role of fascin in OSCC development and/or progression, fascin was overexpressed along with vector control in OSCC derived cells AW13516. The phenotype was studied using wound healing, Boyden chamber, cell adhesion, Hanging drop, soft agar and tumorigenicity assays. Further, fascin expression was examined in human OSCC samples (N = 131) using immunohistochemistry and level of its expression was correlated with clinico-pathological parameters of the patients. Fascin overexpression in OSCC derived cells led to significant increase in cell migration, cell invasion and MMP-2 activity. In addition these cells demonstrated increased levels of phosphorylated AKT, ERK1/2 and JNK1/2. Our in vitro results were consistent with correlative studies of fascin expression with the clinico-pathological parameters of the OSCC patients. Fascin expression in OSCC showed statistically significant correlation with increased tumor stage (P = 0.041), increased lymph node metastasis (P = 0.001), less differentiation (P = 0.005), increased recurrence (P = 0.038) and shorter survival (P = 0.004) of the patients. In conclusion, our results indicate that fascin promotes tumor progression and activates AKT and MAPK pathways in OSCC-derived cells. Further, our correlative studies of fascin expression in OSCC with clinico-pathological parameters of the patients indicate that fascin may prove to be useful in prognostication and treatment of OSCC

  5. Overexpression AtNHX1 confers salt-tolerance of transgenic tall ...

    African Journals Online (AJOL)

    Saline soil is a serious problem worldwide, and it is necessary to improve the salt tolerance of plants so as to avoid the progressive deterioration of saline soil. Here we report that over-expression of AtNHX1 improves salt tolerance in transgenic tall fescue. The AtNHX1 gene driven with CaMV35S promoter was constructed ...

  6. Biomaterials that promote cell-cell interactions enhance the paracrine function of MSCs.

    Science.gov (United States)

    Qazi, Taimoor H; Mooney, David J; Duda, Georg N; Geissler, Sven

    2017-09-01

    Mesenchymal stromal cells (MSCs) secrete paracrine factors that play crucial roles during tissue regeneration. Whether this paracrine function is influenced by the properties of biomaterials in general, and those used for cell delivery in particular, largely remains unexplored. Here, we investigated if three-dimensional culture in distinct microenvironments - nanoporous hydrogels (mean pore size ∼5 nm) and macroporous scaffolds (mean pore size ∼120 μm) - affects the secretion pattern of MSCs, and consequently leads to differential paracrine effects on target progenitor cells such as myoblasts. We report that compared to MSCs encapsulated in hydrogels, scaffold seeded MSCs show an enhanced secretion profile and exert beneficial paracrine effects on various myoblast functions including migration and proliferation. Additionally, we show that the heightened paracrine effects of scaffold seeded cells can in part be attributed to N-cadherin mediated cell-cell interactions during culture. In hydrogels, this physical interaction between cells is prevented by the encapsulating matrix. Functionally blocking N-cadherin negatively affected the secretion profile and paracrine effects of MSCs on myoblasts, with stronger effects observed for scaffold seeded compared to hydrogel encapsulated cells. Together, these findings demonstrate that the therapeutic potency of MSCs can be enhanced by biomaterials that promote cell-cell interactions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Tolerance induced by anti-DNA Ig peptide in (NZB×NZW)F1 lupus mice impinges on the resistance of effector T cells to suppression by regulatory T cells.

    Science.gov (United States)

    Yu, Yiyun; Liu, Yaoyang; Shi, Fu-Dong; Zou, Hejian; Hahn, Bevra H; La Cava, Antonio

    2012-03-01

    We have previously shown that immune tolerance induced by the anti-DNA Ig peptide pCons in (NZB×NZW)F(1) (NZB/W) lupus mice prolonged survival of treated animals and delayed the appearance of autoantibodies and glomerulonephritis. Part of the protection conferred by pCons could be ascribed to the induction of regulatory T cells (T(Reg)) that suppressed the production of anti-DNA antibodies in a p38 MAPK-dependent fashion. Here we show that another effect of pCons in the induction of immune tolerance in NZB/W lupus mice is the facilitation of effector T cell suppression by T(Reg). These new findings indicate that pCons exerts protective effects in NZB/W lupus mice by differentially modulating the activity of different T cell subsets, implying new considerations in the design of T(Reg)-based approaches to modulate T cell autoreactivity in SLE. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. Tolerance-based punishment in continuous public goods game

    Science.gov (United States)

    Gao, Jia; Li, Zhi; Cong, Rui; Wang, Long

    2012-08-01

    Altruistic punishment for defectors is considered as a key motive for the explanation of cooperation. However, there is no clear border between the cooperative and defective behaviors in a continuous strategy game. We propose a model to study the effect of punishment on the evolution of cooperation in continuous public goods game, wherein individuals have the traits to punish the co-players based on social tolerance. We show that a reasonable punishment with a uniform tolerance can spur individuals to make more investments. Additionally, for a fixed punishment cost and a fixed fine, a moderate value of tolerance can result in the best promotion of cooperation. Furthermore, we investigate the coevolutionary dynamics of investment and tolerance. We find that the population splits into two branches: high-tolerance individuals who make high investments and low-tolerance individuals who make low investments. A dynamic equilibrium is achieved between these two types of individuals. Our work extends punishment to continuous cooperative behaviors and the results may enhance the understanding of altruistic punishment in the evolution of human cooperation.

  9. Histone deacetylase inhibitors epigenetically promote reparative events in primary dental pulp cells

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, Henry F., E-mail: Hal.Duncan@dental.tcd.ie [Division of Restorative Dentistry and Periodontology, Dublin Dental University Hospital, Trinity College Dublin, Lincoln Place, Dublin 2 (Ireland); Smith, Anthony J. [Oral Biology, School of Dentistry, College of Medical and Dental Sciences, University of Birmingham, Birmingham (United Kingdom); Fleming, Garry J.P. [Material Science Unit, Division of Oral Biosciences, Dublin Dental University Hospital, Trinity College Dublin, Dublin (Ireland); Cooper, Paul R. [Oral Biology, School of Dentistry, College of Medical and Dental Sciences, University of Birmingham, Birmingham (United Kingdom)

    2013-06-10

    Application of histone deacetylase inhibitors (HDACi) to cells epigenetically alters their chromatin structure and induces transcriptional and cellular reparative events. This study investigated the application of two HDACi, valproic acid (VPA) and trichostatin A (TSA) on the induction of repair-associated responses in primary dental pulp cell (DPC) cultures. Flow cytometry demonstrated that TSA (100 nM, 400 nM) significantly increased cell viability. Neither HDACi was cytotoxic, although cell growth analysis revealed significant anti-proliferative effects at higher concentrations for VPA (>0.5 mM) and TSA (>50 nM). While high-content-analysis demonstrated that HDACi did not significantly induce caspase-3 or p21 activity, p53-expression was increased by VPA (3 mM, 5 mM) at 48 h. HDACi-exposure induced mineralization per cell dose-dependently to a plateau level (VPA-0.125 mM and TSA-25 nM) with accompanying increases in mineralization/dentinogenic-associated gene expression at 5 days (DMP-1, BMP-2/-4, Nestin) and 10 days (DSPP, BMP-2/-4). Both HDACis, at a range of concentrations, significantly stimulated osteopontin and BMP-2 protein expression at 10 and 14 days further supporting the ability of HDACi to promote differentiation. HDACi exert different effects on primary compared with transformed DPCs and promote mineralization and differentiation events without cytotoxic effects. These novel data now highlight the potential in restorative dentistry for applying low concentrations of HDACi in vital pulp treatment. -- Highlights: • Valproic acid and trichostatin A promoted mineralization in primary pulp cells. • Cell viability, apoptosis, caspase-3, p21 unaltered; p53 increased by valproic acid. • Trichostatin A increased cell viability at 24 h at selected concentrations. • Altered cell toxicity and differentiation between primary and transformed cells. • HDACi-induced the differentiation marker proteins osteopontin and BMP-2.

  10. Histone deacetylase inhibitors epigenetically promote reparative events in primary dental pulp cells

    International Nuclear Information System (INIS)

    Duncan, Henry F.; Smith, Anthony J.; Fleming, Garry J.P.; Cooper, Paul R.

    2013-01-01

    Application of histone deacetylase inhibitors (HDACi) to cells epigenetically alters their chromatin structure and induces transcriptional and cellular reparative events. This study investigated the application of two HDACi, valproic acid (VPA) and trichostatin A (TSA) on the induction of repair-associated responses in primary dental pulp cell (DPC) cultures. Flow cytometry demonstrated that TSA (100 nM, 400 nM) significantly increased cell viability. Neither HDACi was cytotoxic, although cell growth analysis revealed significant anti-proliferative effects at higher concentrations for VPA (>0.5 mM) and TSA (>50 nM). While high-content-analysis demonstrated that HDACi did not significantly induce caspase-3 or p21 activity, p53-expression was increased by VPA (3 mM, 5 mM) at 48 h. HDACi-exposure induced mineralization per cell dose-dependently to a plateau level (VPA-0.125 mM and TSA-25 nM) with accompanying increases in mineralization/dentinogenic-associated gene expression at 5 days (DMP-1, BMP-2/-4, Nestin) and 10 days (DSPP, BMP-2/-4). Both HDACis, at a range of concentrations, significantly stimulated osteopontin and BMP-2 protein expression at 10 and 14 days further supporting the ability of HDACi to promote differentiation. HDACi exert different effects on primary compared with transformed DPCs and promote mineralization and differentiation events without cytotoxic effects. These novel data now highlight the potential in restorative dentistry for applying low concentrations of HDACi in vital pulp treatment. -- Highlights: • Valproic acid and trichostatin A promoted mineralization in primary pulp cells. • Cell viability, apoptosis, caspase-3, p21 unaltered; p53 increased by valproic acid. • Trichostatin A increased cell viability at 24 h at selected concentrations. • Altered cell toxicity and differentiation between primary and transformed cells. • HDACi-induced the differentiation marker proteins osteopontin and BMP-2

  11. TP508 accelerates fracture repair by promoting cell growth over cell death

    International Nuclear Information System (INIS)

    Li Xinmin; Wang Hali; Touma, Edward; Qi Yuchen; Rousseau, Emma; Quigg, Richard J.; Ryaby, James T.

    2007-01-01

    TP508 is a synthetic 23-amino acid peptide representing a receptor-binding domain of human thrombin. We have previously shown that a single injection of TP508 accelerates fracture healing in a rat femoral fracture model. To understand how TP508 acts at the protein level during fracture healing, we compared the translational profiles between saline-control and fractured femur at six time points after TP508 treatment using the second generation of BD Clontech TM Antibody Microarray. Here, we demonstrate that TP508 accelerates fracture healing by modulating expression levels of proteins primarily involved in the functional categories of cell cycle, cellular growth and proliferation, and cell death. The majority of those proteins are physically interrelated and functionally overlapped. The action of those proteins is highlighted by a central theme of promoting cell growth via balance of cell survival over cell death signals. This appears to occur through the stimulation of several bone healing pathways including cell cycle-G1/S checkpoint regulation, apoptosis, JAK/STAT, NF-κB, PDGF, PI3K/AKT, PTEN, and ERK/MAPK

  12. Plastid-expressed betaine aldehyde dehydrogenase gene in carrot cultured cells, roots, and leaves confers enhanced salt tolerance.

    Science.gov (United States)

    Kumar, Shashi; Dhingra, Amit; Daniell, Henry

    2004-09-01

    Salinity is one of the major factors that limits geographical distribution of plants and adversely affects crop productivity and quality. We report here high-level expression of betaine aldehyde dehydrogenase (BADH) in cultured cells, roots, and leaves of carrot (Daucus carota) via plastid genetic engineering. Homoplasmic transgenic plants exhibiting high levels of salt tolerance were regenerated from bombarded cell cultures via somatic embryogenesis. Transformation efficiency of carrot somatic embryos was very high, with one transgenic event per approximately seven bombarded plates under optimal conditions. In vitro transgenic carrot cells transformed with the badh transgene were visually green in color when compared to untransformed carrot cells, and this offered a visual selection for transgenic lines. BADH enzyme activity was enhanced 8-fold in transgenic carrot cell cultures, grew 7-fold more, and accumulated 50- to 54-fold more betaine (93-101 micromol g(-1) dry weight of beta-Ala betaine and Gly betaine) than untransformed cells grown in liquid medium containing 100 mm NaCl. Transgenic carrot plants expressing BADH grew in the presence of high concentrations of NaCl (up to 400 mm), the highest level of salt tolerance reported so far among genetically modified crop plants. BADH expression was 74.8% in non-green edible parts (carrots) containing chromoplasts, and 53% in proplastids of cultured cells when compared to chloroplasts (100%) in leaves. Demonstration of plastid transformation via somatic embryogenesis utilizing non-green tissues as recipients of foreign DNA for the first time overcomes two of the major obstacles in extending this technology to important crop plants.

  13. Reactive glia promote development of CD103+ CD69+ CD8+ T-cells through programmed cell death-ligand 1 (PD-L1).

    Science.gov (United States)

    Prasad, Sujata; Hu, Shuxian; Sheng, Wen S; Chauhan, Priyanka; Lokensgard, James R

    2018-06-01

    Previous work from our laboratory has demonstrated in vivo persistence of CD103 + CD69 + brain resident memory CD8 + T-cells (bT RM ) following viral infection, and that the PD-1: PD-L1 pathway promotes development of these T RM cells within the brain. Although glial cells express low basal levels of PD-L1, its expression is upregulated upon IFN-γ-treatment, and they have been shown to modulate antiviral T-cell effector responses through the PD-1: PD-L1 pathway. We performed flow cytometric analysis of cells from co-cultures of mixed glia and CD8 + T-cells obtained from wild type mice to investigate the role of glial cells in the development of bT RM . In this study, we show that interactions between reactive glia and anti-CD3 Ab-stimulated CD8 + T-cells promote development of CD103 + CD69 + CD8 + T-cells through engagement of the PD-1: PD-L1 pathway. These studies used co-cultures of primary murine glial cells obtained from WT animals along with CD8 + T-cells obtained from either WT or PD-1 KO mice. We found that αCD3 Ab-stimulated CD8 + T-cells from WT animals increased expression of CD103 and CD69 when co-cultured with primary murine glial cells. In contrast, significantly reduced expression of CD103 and CD69 was observed using CD8 + T-cells from PD-1 KO mice. We also observed that reactive glia promoted high levels of CD127, a marker of memory precursor effector cells (MPEC), on CD69 + CD8 + T-cells, which promotes development of T RM cells. Interestingly, results obtained using T-cells from PD-1 KO animals showed significantly reduced expression of CD127 on CD69 + CD8 + cells. Additionally, blocking of glial PD-L1 resulted in decreased expression of CD103, along with reduced CD127 on CD69 + CD8 + T-cells. Taken together, these results demonstrate a role for activated glia in promoting development of bT RM through the PD-1: PD-L1 pathway. © 2018 The Authors. Immunity, Inflammation and Disease Published by John Wiley & Sons Ltd.

  14. Polycystin-1 promotes PKCα-mediated NF-κB activation in kidney cells

    International Nuclear Information System (INIS)

    Banzi, Manuela; Aguiari, Gianluca; Trimi, Viky; Mangolini, Alessandra; Pinton, Paolo; Witzgall, Ralph; Rizzuto, Rosario; Senno, Laura del

    2006-01-01

    Polycystin-1 (PC1), the PKD1 gene product, is a membrane receptor which regulates many cell functions, including cell proliferation and apoptosis, both typically increased in cyst lining cells in autosomal dominant polycystic kidney disease. Here we show that PC1 upregulates the NF-κB signalling pathway in kidney cells to prevent cell death. Human embryonic kidney cell lines (HEK293 CTT ), stably expressing a PC1 cytoplasmic terminal tail (CTT), presented increased NF-κB nuclear levels and NF-κB-mediated luciferase promoter activity. This, consistently, was reduced in HEK293 cells in which the endogenous PC1 was depleted by RNA interference. CTT-dependent NF-κB promoter activation was mediated by PKCα because it was blocked by its specific inhibitor Ro-320432. Furthermore, it was observed that apoptosis, which was increased in PC1-depleted cells, was reduced in HEK293 CTT cells and in porcine kidney LtTA cells expressing a doxycycline-regulated CTT. Staurosporine, a PKC inhibitor, and parthenolide, a NF-κB inhibitor, significantly reduced the CTT-dependent antiapoptotic effect. These data reveal, therefore, a novel pathway by which polycystin-1 activates a PKCα-mediated NF-κB signalling and cell survival

  15. CMTM5 exhibits tumor suppressor activity through promoter methylation in oral squamous cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Heyu [Central Laboratory, Peking University School of Stomatology, Beijing (China); Nan, Xu [Center for Human Disease Genomics, Department of Immunology, Key Laboratory of Medical Immunology, Ministry of Health, School of Basic Medical Sciences, Peking University, Beijing (China); Li, Xuefen [Central Laboratory, Peking University School of Stomatology, Beijing (China); Chen, Yan; Zhang, Jianyun [Department of Oral Pathology, Peking University School of Stomatology, Beijing (China); Sun, Lisha [Central Laboratory, Peking University School of Stomatology, Beijing (China); Han, Wenlin [Center for Human Disease Genomics, Department of Immunology, Key Laboratory of Medical Immunology, Ministry of Health, School of Basic Medical Sciences, Peking University, Beijing (China); Li, Tiejun, E-mail: litiejun22@vip.sina.com [Department of Oral Pathology, Peking University School of Stomatology, Beijing (China)

    2014-05-02

    Highlights: • Down-regulation of CMTM5 expression in OSCC tissues was found. • The promoter methylation status of CMTM5 was measured. • CMTM5-v1 inhibited cell proliferation and migration and induced apoptosis. • CMTM5 might act as a putative tumor suppressor gene in OSCC. - Abstract: Oral squamous cell carcinoma (OSCC) is one of the most common types of malignancies in the head and neck region. CKLF-like MARVEL transmembrane domain-containing member 5 (CMTM5) has been recently implicated as a tumor suppressor gene in several cancer types. Herein, we examined the expression and function of CMTM5 in oral squamous cell carcinoma. CMTM5 was down-regulated in oral squamous cell lines and tumor samples from patients with promoter methylation. Treatment with the demethylating agent 5-aza-2′-deoxycytidine restored CMTM5 expression. In the OSCC cell lines CAL27 and GNM, the ectopic expression of CMTM5-v1 strongly inhibited cell proliferation and migration and induced apoptosis. In addition, CMTM5-v1 inhibited tumor formation in vivo. Therefore, CMTM5 might act as a putative tumor suppressor gene through promoter methylation in oral squamous cell carcinoma.

  16. CMTM5 exhibits tumor suppressor activity through promoter methylation in oral squamous cell carcinoma

    International Nuclear Information System (INIS)

    Zhang, Heyu; Nan, Xu; Li, Xuefen; Chen, Yan; Zhang, Jianyun; Sun, Lisha; Han, Wenlin; Li, Tiejun

    2014-01-01

    Highlights: • Down-regulation of CMTM5 expression in OSCC tissues was found. • The promoter methylation status of CMTM5 was measured. • CMTM5-v1 inhibited cell proliferation and migration and induced apoptosis. • CMTM5 might act as a putative tumor suppressor gene in OSCC. - Abstract: Oral squamous cell carcinoma (OSCC) is one of the most common types of malignancies in the head and neck region. CKLF-like MARVEL transmembrane domain-containing member 5 (CMTM5) has been recently implicated as a tumor suppressor gene in several cancer types. Herein, we examined the expression and function of CMTM5 in oral squamous cell carcinoma. CMTM5 was down-regulated in oral squamous cell lines and tumor samples from patients with promoter methylation. Treatment with the demethylating agent 5-aza-2′-deoxycytidine restored CMTM5 expression. In the OSCC cell lines CAL27 and GNM, the ectopic expression of CMTM5-v1 strongly inhibited cell proliferation and migration and induced apoptosis. In addition, CMTM5-v1 inhibited tumor formation in vivo. Therefore, CMTM5 might act as a putative tumor suppressor gene through promoter methylation in oral squamous cell carcinoma

  17. Habituation of enterotoxigenic Staphylococcus aureus to Origanum vulgare L. essential oil does not induce direct-tolerance and cross-tolerance to salts and organic acids

    Directory of Open Access Journals (Sweden)

    Adassa Gama Tavares

    2015-09-01

    Full Text Available Enterotoxigenic Staphylococcus aureus strains that were isolated from foods were investigated for their ability to develop direct-tolerance and cross-tolerance to sodium chloride (NaCl, potassium chloride (KCl, lactic acid (LA and acetic acid (AA after habituation in sublethal amounts (1/2 of the minimum inhibitory concentration - 1/2 MIC and 1/4 of the minimum inhibitory concentration - 1/4 MIC of Origanum vulgare L. essential oil (OVEO. The habituation of S. aureus to 1/2 MIC and 1/4 MIC of OVEO did not induce direct-tolerance or cross-tolerance in the tested strains, as assessed by modulation of MIC values. Otherwise, exposing the strains to OVEO at sublethal concentrations maintained or increased the sensitivity of the cells to the tested stressing agents because the MIC values of OVEO, NaCl, KCl, LA and AA against the cells that were previously habituated to OVEO remained the same or decreased when compared with non-habituated cells. These data indicate that OVEO does not have an inductive effect on the acquisition of direct-tolerance or cross-tolerance in the tested enterotoxigenic strains of S. aureus to antimicrobial agents that are typically used in food preservation.

  18. Towards gene banking amphibian maternal germ lines: short-term incubation, cryoprotectant tolerance and cryopreservation of embryonic cells of the frog, Limnodynastes peronii.

    Science.gov (United States)

    Lawson, Bianca; Clulow, Simon; Mahony, Michael J; Clulow, John

    2013-01-01

    Gene banking is arguably the best method available to prevent the loss of genetic diversity caused by declines in wild populations, when the causes of decline cannot be halted or reversed. For one of the most impacted vertebrate groups, the amphibians, gene banking technologies have advanced considerably, and gametes from the male line can be banked successfully for many species. However, cryopreserving the female germ line remains challenging, with attempts at cryopreserving oocytes unsuccessful due to their large size and yolk content. One possible solution is to target cryopreservation of early embryos that contain the maternal germ line, but consist of smaller cells. Here, we investigate the short term incubation, cryoprotectant tolerance, and cryopreservation of dissociated early embryonic cells from gastrulae and neurulae of the Striped Marsh Frog, Limnodynastes peronii. Embryos were dissociated and cells were incubated for up to 24 hours in various media. Viability of both gastrula and neurula cells remained high (means up to 40-60%) over 24 hours of incubation in all media, although viability was maintained at a higher level in Ca(2+)-free Simplified Amphibian Ringer; low speed centrifugation did not reduce cell viability. Tolerance of dissociated embryonic cells was tested for two cryoprotectants, glycerol and dimethyl sulphoxide; dissociated cells of both gastrulae and neurulae were highly tolerant to both-indeed, cell viability over 24 hours was higher in media containing low-to-medium concentrations than in equivalent cryoprotectant-free media. Viability over 24 hours was lower in concentrations of cryoprotectant higher than 10%. Live cells were recovered following cryopreservation of both gastrula and neurula cells, but only at low rates. Optimal cryodiluents were identified for gastrula and neurula cells. This is the first report of a slow cooling protocol for cryopreservation of amphibian embryonic cells, and sets future research directions for

  19. Towards gene banking amphibian maternal germ lines: short-term incubation, cryoprotectant tolerance and cryopreservation of embryonic cells of the frog, Limnodynastes peronii.

    Directory of Open Access Journals (Sweden)

    Bianca Lawson

    Full Text Available Gene banking is arguably the best method available to prevent the loss of genetic diversity caused by declines in wild populations, when the causes of decline cannot be halted or reversed. For one of the most impacted vertebrate groups, the amphibians, gene banking technologies have advanced considerably, and gametes from the male line can be banked successfully for many species. However, cryopreserving the female germ line remains challenging, with attempts at cryopreserving oocytes unsuccessful due to their large size and yolk content. One possible solution is to target cryopreservation of early embryos that contain the maternal germ line, but consist of smaller cells. Here, we investigate the short term incubation, cryoprotectant tolerance, and cryopreservation of dissociated early embryonic cells from gastrulae and neurulae of the Striped Marsh Frog, Limnodynastes peronii. Embryos were dissociated and cells were incubated for up to 24 hours in various media. Viability of both gastrula and neurula cells remained high (means up to 40-60% over 24 hours of incubation in all media, although viability was maintained at a higher level in Ca(2+-free Simplified Amphibian Ringer; low speed centrifugation did not reduce cell viability. Tolerance of dissociated embryonic cells was tested for two cryoprotectants, glycerol and dimethyl sulphoxide; dissociated cells of both gastrulae and neurulae were highly tolerant to both-indeed, cell viability over 24 hours was higher in media containing low-to-medium concentrations than in equivalent cryoprotectant-free media. Viability over 24 hours was lower in concentrations of cryoprotectant higher than 10%. Live cells were recovered following cryopreservation of both gastrula and neurula cells, but only at low rates. Optimal cryodiluents were identified for gastrula and neurula cells. This is the first report of a slow cooling protocol for cryopreservation of amphibian embryonic cells, and sets future research

  20. Sonic hedgehog promotes stem-cell potential of Mueller glia in the mammalian retina

    International Nuclear Information System (INIS)

    Wan Jin; Zheng Hua; Xiao Honglei; She Zhenjue; Zhou Guomin

    2007-01-01

    Mueller glia have been demonstrated to display stem-cell properties after retinal damage. Here, we report this potential can be regulated by Sonic hedgehog (Shh) signaling. Shh can stimulate proliferation of Mueller glia through its receptor and target gene expressed on them, furthermore, Shh-treated Mueller glia are induced to dedifferentiate by expressing progenitor-specific markers, and then adopt cell fate of rod photoreceptor. Inhibition of signaling by cyclopamine inhibits proliferation and dedifferentiation. Intraocular injection of Shh promotes Mueller glia activation in the photoreceptor-damaged retina, Shh also enhances neurogenic potential by producing more rhodopsin-positive photoreceptors from Mueller glia-derived cells. Together, these results provide evidences that Mueller glia act as potential stem cells in mammalian retina, Shh may have therapeutic effects on these cells for promoting the regeneration of retinal neurons

  1. Sonic hedgehog promotes stem-cell potential of Mueller glia in the mammalian retina

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Wan; Hua, Zheng; Honglei, Xiao; Zhenjue, She [Department of Anatomy, Histology and Embryology, Shanghai Medical School, Fudan University, 200032 Shanghai (China); Zhou Guomin [Department of Anatomy, Histology and Embryology, Shanghai Medical School, Fudan University, 200032 Shanghai (China)], E-mail: gmzhou185@yahoo.com.cn

    2007-11-16

    Mueller glia have been demonstrated to display stem-cell properties after retinal damage. Here, we report this potential can be regulated by Sonic hedgehog (Shh) signaling. Shh can stimulate proliferation of Mueller glia through its receptor and target gene expressed on them, furthermore, Shh-treated Mueller glia are induced to dedifferentiate by expressing progenitor-specific markers, and then adopt cell fate of rod photoreceptor. Inhibition of signaling by cyclopamine inhibits proliferation and dedifferentiation. Intraocular injection of Shh promotes Mueller glia activation in the photoreceptor-damaged retina, Shh also enhances neurogenic potential by producing more rhodopsin-positive photoreceptors from Mueller glia-derived cells. Together, these results provide evidences that Mueller glia act as potential stem cells in mammalian retina, Shh may have therapeutic effects on these cells for promoting the regeneration of retinal neurons.

  2. TIM-1 Promotes Hepatitis C Virus Cell Attachment and Infection.

    Science.gov (United States)

    Wang, Jing; Qiao, Luhua; Hou, Zhouhua; Luo, Guangxiang

    2017-01-15

    Human TIM and TAM family proteins were recently found to serve as phosphatidylserine (PS) receptors which promote infections by many different viruses, including dengue virus, West Nile virus, Ebola virus, Marburg virus, and Zika virus. In the present study, we provide substantial evidence demonstrating that TIM-1 is important for efficient infection by hepatitis C virus (HCV). The knockdown of TIM-1 expression significantly reduced HCV infection but not HCV RNA replication. Likewise, TIM-1 knockout in Huh-7.5 cells remarkably lowered HCV cell attachment and subsequent HCV infection. More significantly, the impairment of HCV infection in the TIM-1 knockout cells could be restored completely by ectopic expression of TIM-1 but not TIM-3 or TIM-4. Additionally, HCV infection and cell attachment were inhibited by PS but not by phosphatidylcholine (PC), demonstrating that TIM-1-mediated enhancement of HCV infection is PS dependent. The exposure of PS on the HCV envelope was confirmed by immunoprecipitation of HCV particles with a PS-specific monoclonal antibody. Collectively, these findings demonstrate that TIM-1 promotes HCV infection by serving as an attachment receptor for binding to PS exposed on the HCV envelope. TIM family proteins were recently found to enhance infections by many different viruses, including several members of the Flaviviridae family. However, their importance in HCV infection has not previously been examined experimentally. The TIM family proteins include three members in humans: TIM-1, TIM-3, and TIM-4. The findings derived from our studies demonstrate that TIM-1, but not TIM-3 or TIM-4, promotes HCV infection by functioning as an HCV attachment factor. Knockout of the TIM-1 gene resulted in a remarkable reduction of HCV cell attachment and infection. PS-containing liposomes blocked HCV cell attachment and subsequent HCV infection. HCV particles could also be precipitated with a PS-specific monoclonal antibody. These findings suggest that TIM-1

  3. Design of Polymeric Culture Substrates to Promote Proangiogenic Potential of Stem Cells.

    Science.gov (United States)

    Kwon, Byeong-Ju; Wang, Xintong; Kang, Mi-Lan; You, Jin; Lee, Shin-Jeong; Kim, Won Shik; Yoon, Young-Sup; Park, Jong-Chul; Sung, Hak-Joon

    2018-02-01

    Stem cells are a promising cell source for regenerative medicine due to their differentiation and self-renewal capacities. In the field of regenerative medicine and tissue engineering, a variety of biomedical technologies have been tested to improve proangiogenic activities of stem cells. However, their therapeutic effect is found to be limited in the clinic because of cell loss, senescence, and insufficient therapeutic activities. To address this type of issue, advanced techniques for biomaterial synthesis and fabrication have been approached to mimic proangiogenic microenvironment and to direct proangiogenic activities. This review highlights the types of polymers and design strategies that have been studied to promote proangiogenic activities of stem cells. In particular, scaffolds, hydrogels, and surface topographies, as well as insight into their underlying mechanisms to improve proangiogenic activities are the focuses. The strategy to promote angiogenic activities of hMSCs by controlling substrate repellency is introduced, and the future direction is proposed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Auto Poisoning of the Respiratory Chain by a Quorum Sensing Regulated Molecule Favors Biofilm Formation and Antibiotic Tolerance

    Science.gov (United States)

    Hazan, Ronen; Que, Yok Ai; Maura, Damien; Strobel, Benjamin; Majcherczyk, Paul Anthony; Hopper, Laura Rose; Wilbur, David J.; Hreha, Teri N.; Barquera, Blanca; Rahme, Laurence G.

    2015-01-01

    Summary Bacterial programmed cell death and quorum sensing are direct examples of prokaryote group behaviors, wherein cells coordinate their actions to function cooperatively like one organism for the benefit of the whole culture. We demonstrate here that 2-n-heptyl-4-hydroxyquinoline-N-oxide (HQNO), a Pseudomonas aeruginosa quorum sensing -regulated low-molecular-weight excreted molecule, and triggers autolysis by self-perturbing the electron transfer reactions of the cytochrome bc1 complex. HQNO induces specific self-poisoning by disrupting the flow of electrons through the respiratory chain at the cytochrome bc1 complex, causing a leak of reducing equivalents to O2 whereby electrons that would normally be passed to cytochrome c are donated directly to O2. The subsequent mass production of reactive oxygen species (ROS) reduces membrane potential and disrupts membrane integrity, causing bacterial cell autolysis and DNA release. DNA subsequently promotes biofilm formation and increases antibiotic tolerance to beta-lactams, suggesting that HQNO-dependent cell autolysis is advantageous to the bacterial populations. These data both identify a new programmed cell death system, and a novel role for HQNO as a critical-inducer of biofilm formation and antibiotic tolerance. This newly identified pathway suggests intriguing mechanistic similarities with the initial mitochondrial-mediated steps of eukaryotic apoptosis. PMID:26776731

  5. Enhanced incorporation of radioactive inorganic phosphate into phospholipids of HeLa cells by tumor promoters

    International Nuclear Information System (INIS)

    Nishino, H.; Fujiki, H.; Terada, M.; Sato, S.

    1983-01-01

    Teleocidin, a new tumor promoter, increased incorporation of radioactive inorganic phosphate ( 32 P/sub i/) into phospholipids in HeLa cells. This effect was detected within 1 h on incubation of the cells in medium containing teleocidin. The half-maximum effective dose of teleocidin was approximately 10 ng/ml. The main effect of teleocidin was on the incorporation of 32 P/sub i/ into the phosphatidylcholine fraction, with a lesser effect on 32 P/sub i/ incorporation into other phospholipid fractions. Increased incorporation of 32 P/sub i/ into phospholipids was also observed on incubation of the cells with 12-O-tetradecanoylphorbol-13-acetate (TPA), dihydroteleocidin B, or lyngbyatoxin A, which are all complete tumor promoters, and also with mezerein, which is an incomplete and second stage promoter. On the other hand, at concentrations of up to 1 microgram/ml, 4-O-methyl TPA and C/sub a/ 2 + ionophore A23187, which are incomplete and first stage promoters, and phorbol, which has no promoting activity in skin carcinogenesis, did not cause any increased incorporation of 32 P/sub i/ into phospholipid fractions of HeLa cells

  6. CXCL17 expression by tumor cells recruits CD11b+Gr1 high F4/80- cells and promotes tumor progression.

    Directory of Open Access Journals (Sweden)

    Aya Matsui

    Full Text Available BACKGROUND: Chemokines are involved in multiple aspects of pathogenesis and cellular trafficking in tumorigenesis. In this study, we report that the latest member of the C-X-C-type chemokines, CXCL17 (DMC/VCC-1, recruits immature myeloid-derived cells and enhances early tumor progression. METHODOLOGY/PRINCIPAL FINDINGS: CXCL17 was preferentially expressed in some aggressive types of gastrointestinal, breast, and lung cancer cells. CXCL17 expression did not impart NIH3T3 cells with oncogenic potential in vitro, but CXCL17-expressing NIH3T3 cells could form vasculature-rich tumors in immunodeficient mice. Our data showed that CXCL17-expressing tumor cells increased immature CD11b(+Gr1(+ myeloid-derived cells at tumor sites in mice and promoted CD31(+ tumor angiogenesis. Extensive chemotactic assays proved that CXCL17-responding cells were CD11b(+Gr1(highF4/80(- cells (≈ 90% with a neutrophil-like morphology in vitro. Although CXCL17 expression could not increase the number of CD11b(+Gr1(+ cells in tumor-burdened SCID mice or promote metastases of low metastatic colon cancer cells, the existence of CXCL17-responding myeloid-derived cells caused a striking enhancement of xenograft tumor formation. CONCLUSIONS/SIGNIFICANCE: These results suggest that aberrant expression of CXCL17 in tumor cells recruits immature myeloid-derived cells and promotes tumor progression through angiogenesis.

  7. Interstitial flows promote an amoeboid cell phenotype and motility of breast cancer cells

    Science.gov (United States)

    Tung, Chih-Kuan; Huang, Yu Ling; Zheng, Angela; Wu, Mingming

    2015-03-01

    Lymph nodes, the drainage systems for interstitial flows, are clinically known to be the first metastatic sites of many cancer types including breast and prostate cancers. Here, we demonstrate that breast cancer cell morphology and motility is modulated by interstitial flows in a cell-ECM adhesion dependent manner. The average aspect ratios of the cells are significantly lower (or are more amoeboid like) in the presence of the flow in comparison to the case when the flow is absent. The addition of exogenous adhesion molecules within the extracellular matrix (type I collagen) enhances the overall aspect ratio (or are more mesenchymal like) of the cell population. Using measured cell trajectories, we find that the persistence of the amoeboid cells (aspect ratio less than 2.0) is shorter than that of mesenchymal cells. However, the maximum speed of the amoeboid cells is larger than that of mesenchymal cells. Together these findings provide the novel insight that interstitial flows promote amoeboid cell morphology and motility and highlight the plasticity of tumor cell motility in response to its biophysical environment. Supported by NIH Grant R21CA138366.

  8. Improved tolerance toward fungal diseases in transgenic Cavendish banana (Musa spp. AAA group) cv. Grand Nain.

    Science.gov (United States)

    Vishnevetsky, Jane; White, Thomas L; Palmateer, Aaron J; Flaishman, Moshe; Cohen, Yuval; Elad, Yigal; Velcheva, Margarita; Hanania, Uri; Sahar, Nachman; Dgani, Oded; Perl, Avihai

    2011-02-01

    The most devastating disease currently threatening to destroy the banana industry worldwide is undoubtedly Sigatoka Leaf spot disease caused by Mycosphaerella fijiensis. In this study, we developed a transformation system for banana and expressed the endochitinase gene ThEn-42 from Trichoderma harzianum together with the grape stilbene synthase (StSy) gene in transgenic banana plants under the control of the 35S promoter and the inducible PR-10 promoter, respectively. The superoxide dismutase gene Cu,Zn-SOD from tomato, under control of the ubiquitin promoter, was added to this cassette to improve scavenging of free radicals generated during fungal attack. A 4-year field trial demonstrated several transgenic banana lines with improved tolerance to Sigatoka. As the genes conferring Sigatoka tolerance may have a wide range of anti-fungal activities we also inoculated the regenerated banana plants with Botrytis cinerea. The best transgenic lines exhibiting Sigatoka tolerance were also found to have tolerance to B. cinerea in laboratory assays.

  9. Osteogenic differentiation of mouse mesenchymal progenitor cell, Kusa-A1 is promoted by mammalian transcriptional repressor Rbpj

    International Nuclear Information System (INIS)

    Wang, Shengchao; Kawashima, Nobuyuki; Sakamoto, Kei; Katsube, Ken-ichi; Umezawa, Akihiro; Suda, Hideaki

    2010-01-01

    Research highlights: → High Rbpj mRNA expression was observed in mesenchymal cells surrounding the bone of mouse embryos. → Overexpression of Rbpj depressed Notch-Hes1/Hey1 signaling. → Rbpj upregulated promoter activities of Runx2 and Ose2. → Rbpj promoted osteoblastic differentiation/maturation in Kusa-A1 cells. -- Abstract: Pluripotent mesenchymal stem cells possess the ability to differentiate into many cell types, but the precise mechanisms of differentiation are still unclear. Here, we provide evidence that Rbpj (recombination signal-binding protein for immunoglobulin kappa j region) protein, the primary nuclear mediator of Notch, is involved in osteogenesis. Overexpression of Rbpj promoted osteogenic differentiation of mouse Kusa-A1 cells in vitro and in vivo. Transient transfection of an Rbpj expression vector into Kusa-A1 cells upregulated promoter activities of Runx2 and Ose2. Enhanced osteogenic potentials including high alkaline phosphatase activity, rapid calcium deposition, and increased calcified nodule formation, were observed in established stable Rbpj-overexpressing Kusa-A1 (Kusa-A1/Rbpj) cell line. In vivo mineralization by Kusa-A1/Rbpj was promoted compared to that by Kusa-A1 host cells. Histological findings revealed that expression of Rbpj was primarily observed in osteoblasts. These results suggest that Rbpj may play essential roles in osteoblast differentiation.

  10. Osteogenic differentiation of mouse mesenchymal progenitor cell, Kusa-A1 is promoted by mammalian transcriptional repressor Rbpj

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shengchao [Department of Preventive Dentistry, School of Stomatology, The Fourth Military Medical University, 145 West Changle Road, 710032 Xi' an (China); Kawashima, Nobuyuki, E-mail: kawashima.n.endo@tmd.ac.jp [Department of Pulp Biology and Endodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549 (Japan); Sakamoto, Kei; Katsube, Ken-ichi [Department of Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549 (Japan); Umezawa, Akihiro [Department of Reproductive Biology and Pathology, National Institute for Child Health and Development, 2-10-4 Ohkura, Setagaya-ku, Tokyo 157-8535 (Japan); Suda, Hideaki [Department of Pulp Biology and Endodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549 (Japan); GCOE Program, International Research Center for Molecular Science in Tooth and Bone Diseases, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549 (Japan)

    2010-09-10

    Research highlights: {yields} High Rbpj mRNA expression was observed in mesenchymal cells surrounding the bone of mouse embryos. {yields} Overexpression of Rbpj depressed Notch-Hes1/Hey1 signaling. {yields} Rbpj upregulated promoter activities of Runx2 and Ose2. {yields} Rbpj promoted osteoblastic differentiation/maturation in Kusa-A1 cells. -- Abstract: Pluripotent mesenchymal stem cells possess the ability to differentiate into many cell types, but the precise mechanisms of differentiation are still unclear. Here, we provide evidence that Rbpj (recombination signal-binding protein for immunoglobulin kappa j region) protein, the primary nuclear mediator of Notch, is involved in osteogenesis. Overexpression of Rbpj promoted osteogenic differentiation of mouse Kusa-A1 cells in vitro and in vivo. Transient transfection of an Rbpj expression vector into Kusa-A1 cells upregulated promoter activities of Runx2 and Ose2. Enhanced osteogenic potentials including high alkaline phosphatase activity, rapid calcium deposition, and increased calcified nodule formation, were observed in established stable Rbpj-overexpressing Kusa-A1 (Kusa-A1/Rbpj) cell line. In vivo mineralization by Kusa-A1/Rbpj was promoted compared to that by Kusa-A1 host cells. Histological findings revealed that expression of Rbpj was primarily observed in osteoblasts. These results suggest that Rbpj may play essential roles in osteoblast differentiation.

  11. CD4 Depletion or CD40L Blockade Results in Antigen-Specific Tolerance in a Red Blood Cell Alloimmunization Model

    Directory of Open Access Journals (Sweden)

    Prabitha Natarajan

    2017-08-01

    Full Text Available Approximately 3–10% of human red blood cell (RBC transfusion recipients form alloantibodies to non-self, non-ABO blood group antigens expressed on donor RBCs, with these alloantibodies having the potential to be clinically significant in transfusion and pregnancy settings. However, the majority of transfused individuals never form detectable alloantibodies. Expanding upon observations that children initially transfused with RBCs at a young age are less likely to form alloantibodies throughout their lives, we hypothesized that “non-responders” may not only be ignorant of antigens on RBCs but instead tolerized. We investigated this question in a reductionist murine model, in which transgenic donors express the human glycophorin A (hGPA antigen in an RBC-specific manner. Although wild-type mice treated with poly IC and transfused with hGPA RBCs generated robust anti-hGPA IgG alloantibodies that led to rapid clearance of incompatible RBCs, those transfused in the absence of an adjuvant failed to become alloimmunized. Animals depleted of CD4+ cells or treated with CD40L blockade prior to initial hGPA RBC exposure, in the presence of poly IC, failed to generate detectable anti-hGPA IgG alloantibodies. These non-responders to a primary transfusion remained unable to generate anti-hGPA IgG alloantibodies upon secondary hGPA exposure and did not prematurely clear transfused hGPA RBCs even after their CD4 cells had returned or their CD40L blockade had resolved. This observed tolerance was antigen (hGPA specific, as robust IgG responses to transfused RBCs expressing a third-party antigen occurred in all studied groups. Experiments completed in an RBC alloimmunization model that allowed evaluation of antigen-specific CD4+ T-cells (HOD (hen egg lysozyme, ovalbumin, and human duffyb demonstrated that CD40L blockade prevented the expansion of ovalbumin 323-339 specific T-cells after HOD RBC transfusion and also prevented germinal center formation. Taken

  12. Fibronectin promotes differentiation of neural crest progenitors endowed with smooth muscle cell potential

    International Nuclear Information System (INIS)

    Costa-Silva, Bruno; Coelho da Costa, Meline; Melo, Fernanda Rosene; Neves, Cynara Mendes; Alvarez-Silva, Marcio; Calloni, Giordano Wosgrau; Trentin, Andrea Goncalves

    2009-01-01

    The neural crest (NC) is a model system used to investigate multipotency during vertebrate development. Environmental factors control NC cell fate decisions. Despite the well-known influence of extracellular matrix molecules in NC cell migration, the issue of whether they also influence NC cell differentiation has not been addressed at the single cell level. By analyzing mass and clonal cultures of mouse cephalic and quail trunk NC cells, we show for the first time that fibronectin (FN) promotes differentiation into the smooth muscle cell phenotype without affecting differentiation into glia, neurons, and melanocytes. Time course analysis indicated that the FN-induced effect was not related to massive cell death or proliferation of smooth muscle cells. Finally, by comparing clonal cultures of quail trunk NC cells grown on FN and collagen type IV (CLIV), we found that FN strongly increased both NC cell survival and the proportion of unipotent and oligopotent NC progenitors endowed with smooth muscle potential. In contrast, melanocytic progenitors were prominent in clonogenic NC cells grown on CLIV. Taken together, these results show that FN promotes NC cell differentiation along the smooth muscle lineage, and therefore plays an important role in fate decisions of NC progenitor cells

  13. Expression of Nanog gene promotes NIH3T3 cell proliferation

    International Nuclear Information System (INIS)

    Zhang Jingyu; Wang Xia; Chen Bing; Suo Guangli; Zhao Yanhong; Duan Ziyuan; Dai Jianwu

    2005-01-01

    Cells are the functional elements in tissue engineering and regenerative medicine. A large number of cells are usually needed for these purposes. However, there are numbers of limitations for in vitro cell proliferation. Nanog is an important self-renewal determinant in embryonic stem cells. However, it remains unknown whether Nanog will influence the cell cycle and cell proliferation of mature cells. In this study, we expressed Nanog in NIH3T3 cells and showed that expression of Nanog in NIH3T3 promoted cells to enter into S phase and enhanced cell proliferation. This suggests that Nanog gene might function in a similar fashion in mature cells as in ES cells. In addition, it may provide an approach for in vitro cell expansion

  14. Triiodothyronine promotes the proliferation of epicardial progenitor cells through the MAPK/ERK pathway

    International Nuclear Information System (INIS)

    Deng, Song-Bai; Jing, Xiao-Dong; Wei, Xiao-ming; Du, Jian-Lin; Liu, Ya-Jie; Qin, Qin; She, Qiang

    2017-01-01

    Thyroid hormone has important functions in the development and physiological function of the heart. The aim of this study was to determine whether 3,5,3′-Triiodothyronine (T3) can promote the proliferation of epicardial progenitor cells (EPCs) and to investigate the potential underlying mechanism. Our results showed that T3 significantly promoted the proliferation of EPCs in a concentration- and time-dependent manner. The thyroid hormone nuclear receptor inhibitor bisphenol A (100 μmol/L) did not affect T3's ability to induce proliferation. Further studies showed that the mRNA expression levels of mitogen-activated protein kinase 1 (MAPK1), MAPK3, and Ki67 in EPCs in the T3 group (10 nmol/L) increased 2.9-, 3-, and 4.1-fold, respectively, compared with those in the control group (P < 0.05). In addition, the mRNA expression of the cell cycle protein cyclin D1 in the T3 group increased approximately 2-fold compared with the control group (P < 0.05), and there were more EPCs in the S phase of the cell cycle (20.6% vs. 12.0%, P < 0.05). The mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling pathway inhibitor U0126 (10 μmol/L) significantly inhibited the ability of T3 to promote the proliferation of EPCs and to alter cell cycle progression. This study suggested that T3 significantly promotes the proliferation of EPCs, and this effect may be achieved through activation of the MAPK/ERK signaling pathway. - Highlights: • Epicardial progenitor cells were successfully cultured from E12.5 mice. • Thyroid hormone T3 significantly promoted the proliferation of EPCs. • This biological effect may be mediated via activation of the MAPK/ERK pathway.

  15. Transcriptomic variation among six Arabidopsis thaliana accessions identified several novel genes controlling aluminium tolerance.

    Science.gov (United States)

    Kusunoki, Kazutaka; Nakano, Yuki; Tanaka, Keisuke; Sakata, Yoichi; Koyama, Hiroyuki; Kobayashi, Yuriko

    2017-02-01

    Differences in the expression levels of aluminium (Al) tolerance genes are a known determinant of Al tolerance among plant varieties. We combined transcriptomic analysis of six Arabidopsis thaliana accessions with contrasting Al tolerance and a reverse genetic approach to identify Al-tolerance genes responsible for differences in Al tolerance between accession groups. Gene expression variation increased in the signal transduction process under Al stress and in growth-related processes in the absence of stress. Co-expression analysis and promoter single nucleotide polymorphism searching suggested that both trans-acting polymorphisms of Al signal transduction pathway and cis-acting polymorphisms in the promoter sequences caused the variations in gene expression associated with Al tolerance. Compared with the wild type, Al sensitivity increased in T-DNA knockout (KO) lines for five genes, including TARGET OF AVRB OPERATION1 (TAO1) and an unannotated gene (At5g22530). These were identified from 53 Al-inducible genes showing significantly higher expression in tolerant accessions than in sensitive accessions. These results indicate that the difference in transcriptional signalling is partly associated with the natural variation in Al tolerance in Arabidopsis. Our study also demonstrates the feasibility of comparative transcriptome analysis by using natural genetic variation for the identification of genes responsible for Al stress tolerance. © 2016 John Wiley & Sons Ltd.

  16. Artificial sweeteners and mixture of food additives cause to break oral tolerance and induce food allergy in murine oral tolerance model for food allergy.

    Science.gov (United States)

    Yamashita, H; Matsuhara, H; Miotani, S; Sako, Y; Matsui, T; Tanaka, H; Inagaki, N

    2017-09-01

    Processed foods are part of daily life. Almost all processed foods contain food additives such as sweeteners, preservatives and colourants. From childhood, it is difficult to avoid consuming food additives. It is thought that oral tolerance for food antigens is acquired during early life. If tolerance fails, adverse immune responses to food proteins may occur. We hypothesized that food additives prevent acquisition of oral tolerance and aimed to verify the safety of food additives. We induced experimental oral tolerance in mice for ovalbumin (OVA), a food antigen, by previous oral treatment with OVA before sensitization with OVA injections. Food additives were administered at the induction of oral tolerance, and food allergy was induced by repeated administration of OVA. Symptoms of food allergy were defined as a change in body temperature and allergic diarrhoea. Saccharin sodium and a mixture of food additives inhibited acquisition of oral tolerance. Hypothermia and allergic diarrhoea with elevation of OVA-specific IgE were induced in the murine model of oral tolerance. Analyses of antigen-presenting cells in mesenteric lymph nodes showed that food additives affected their manner of migration. Additionally, food additives decreased the proportion of CD25 hi regulatory T cells among CD4 + T cells in the mesenteric lymph nodes. A large amount of food additives may prevent acquisition of oral tolerance. Intake of food additives in early life may increase the risk of food allergies. © 2017 John Wiley & Sons Ltd.

  17. Megakaryocytes promote murine osteoblastic HSC niche expansion and stem cell engraftment after radioablative conditioning

    OpenAIRE

    Olson, Timothy S.; Caselli, Anna; Otsuru, Satoru; Hofmann, Ted J.; Williams, Richard; Paolucci, Paolo; Dominici, Massimo; Horwitz, Edwin M.

    2013-01-01

    After radioablative conditioning, host megakaryocytes promote endosteal HSC niche expansion and donor stem cell engraftment.Thrombopoietin administration before radiation and bone marrow transplant enhances megakaryocyte promotion of HSC engraftment.

  18. Restoring conjunctival tolerance by topical nuclear factor-κB inhibitors reduces preservative-facilitated allergic conjunctivitis in mice.

    Science.gov (United States)

    Guzmán, Mauricio; Sabbione, Florencia; Gabelloni, María Laura; Vanzulli, Silvia; Trevani, Analía Silvina; Giordano, Mirta Nilda; Galletti, Jeremías Gastón

    2014-09-04

    To evaluate the role of nuclear factor-κB (NF-κB) activation in eye drop preservative toxicity and the effect of topical NF-κB inhibitors on preservative-facilitated allergic conjunctivitis. Balb/c mice were instilled ovalbumin (OVA) combined with benzalkonium chloride (BAK) and/or NF-κB inhibitors in both eyes. After immunization, T-cell responses and antigen-induced ocular inflammation were evaluated. Nuclear factor-κB activation and associated inflammatory changes also were assessed in murine eyes and in an epithelial cell line after BAK exposure. Benzalkonium chloride promoted allergic inflammation and leukocyte infiltration of the conjunctiva. Topical NF-κB inhibitors blocked the disruptive effect of BAK on conjunctival immunological tolerance and ameliorated subsequent ocular allergic reactions. In line with these findings, BAK induced NF-κB activation and the secretion of IL-6 and granulocyte-monocyte colony-stimulating factor in an epithelial cell line and in the conjunctiva of instilled mice. In addition, BAK favored major histocompatibility complex (MHC) II expression in cultured epithelial cells in an NF-κB-dependent fashion after interaction with T cells. Benzalkonium chloride triggers conjunctival epithelial NF-κB activation, which seems to mediate some of its immune side effects, such as proinflammatory cytokine release and increased MHC II expression. Breakdown of conjunctival tolerance by BAK favors allergic inflammation, and this effect can be prevented in mice by topical NF-κB inhibitors. These results suggest a new pharmacological target for preservative toxicity and highlight the importance of conjunctival tolerance in ocular surface homeostasis. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

  19. Differentiation and distribution of colistin- and sodium dodecyl sulfate-tolerant cells in Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Haagensen, Janus Anders Juul; Klausen, M; Ernst, RK

    2007-01-01

    During Pseudomonas aeruginosa flow cell biofilm development, the cell population differentiates into a nonmotile subpopulation which forms microcolonies and a migrating subpopulation which eventually colonizes the top of the microcolonies, resulting in the development of mushroom-shaped multicell......During Pseudomonas aeruginosa flow cell biofilm development, the cell population differentiates into a nonmotile subpopulation which forms microcolonies and a migrating subpopulation which eventually colonizes the top of the microcolonies, resulting in the development of mushroom......-targeting antibacterial agents. All biofilm-associated cells were sensitive to the antibacterial agents when tested in standard plate assays. A mutation eliminating the production of type IV pili, and hence surface-associated motility, prevented the formation of regular mushroom-shaped structures in the flow cell...... that only the cap-forming subpopulation in biofilms treated with colistin expresses the pmr operon. These results suggest that increased antibiotic tolerance in biofilms may be a consequence of differentiation into distinct subpopulations with different phenotypic properties....

  20. Nanoparticles carrying neurotrophin-3-modified Schwann cells promote repair of sciatic nerve defects.

    Science.gov (United States)

    Zong, Haibin; Zhao, Hongxing; Zhao, Yilei; Jia, Jingling; Yang, Libin; Ma, Chao; Zhang, Yang; Dong, Yuzhen

    2013-05-15

    Schwann cells and neurotrophin-3 play an important role in neural regeneration, but the secretion of neurotrophin-3 from Schwann cells is limited, and exogenous neurotrophin-3 is inactived easily in vivo. In this study, we have transfected neurotrophin-3 into Schwann cells cultured in vitro using nanoparticle liposomes. Results showed that neurotrophin-3 was successfully transfected into Schwann cells, where it was expressed effectively and steadily. A composite of Schwann cells transfected with neurotrophin-3 and poly(lactic-co-glycolic acid) biodegradable conduits was transplanted into rats to repair 10-mm sciatic nerve defects. Transplantation of the composite scaffold could restore the myoelectricity and wave amplitude of the sciatic nerve by electrophysiological examination, promote nerve axonal and myelin regeneration, and delay apoptosis of spinal motor neurons. Experimental findings indicate that neurotrophin-3 transfected Schwann cells combined with bridge grafting can promote neural regeneration and functional recovery after nerve injury.

  1. Ectopic expression of phloem motor protein pea forisome PsSEO-F1 enhances salinity stress tolerance in tobacco.

    Science.gov (United States)

    Srivastava, Vineet Kumar; Raikwar, Shailendra; Tuteja, Renu; Tuteja, Narendra

    2016-05-01

    PsSEOF-1 binds to calcium and its expression is upregulated by salinity treatment. PsSEOF - 1 -overexpressing transgenic tobacco showed enhanced salinity stress tolerance by maintaining cellular ion homeostasis and modulating ROS-scavenging pathway. Calcium (Ca(2+)) plays important role in growth, development and stress tolerance in plants. Cellular Ca(2+) homeostasis is achieved by the collective action of channels, pumps, antiporters and by Ca(2+) chelators present in the cell like calcium-binding proteins. Forisomes are ATP-independent mechanically active motor proteins known to function in wound sealing of injured sieve elements of phloem tissue. The Ca(2+)-binding activity of forisome and its role in abiotic stress signaling were largely unknown. Here we report the Ca(2+)-binding activity of pea forisome (PsSEO-F1) and its novel function in promoting salinity tolerance in transgenic tobacco. Native PsSEO-F1 promoter positively responded in salinity stress as confirmed using GUS reporter. Overexpression of PsSEO-F1 tobacco plants confers salinity tolerance by alleviating ionic toxicity and increased ROS scavenging activity which probably results in reduced membrane damage and improved yield under salinity stress. Evaluation of several physiological indices shows an increase in relative water content, electrolyte leakage, proline accumulation and chlorophyll content in transgenic lines as compared with null-segregant control. Expression of several genes involved in cellular homeostasis is perturbed by PsSEO-F1 overexpression. These findings suggest that PsSEO-F1 provides salinity tolerance through cellular Ca(2+) homeostasis which in turn modulates ROS machinery providing indirect link between Ca(2+) and ROS signaling under salinity-induced perturbation. PsSEO-F1 most likely functions in salinity stress tolerance by improving antioxidant machinery and mitigating ion toxicity in transgenic lines. This finding should make an important contribution in our better

  2. Plant-based oral tolerance to hemophilia therapy employs a complex immune regulatory response including LAP+CD4+ T cells.

    Science.gov (United States)

    Wang, Xiaomei; Su, Jin; Sherman, Alexandra; Rogers, Geoffrey L; Liao, Gongxian; Hoffman, Brad E; Leong, Kam W; Terhorst, Cox; Daniell, Henry; Herzog, Roland W

    2015-04-09

    Coagulation factor replacement therapy for the X-linked bleeding disorder hemophilia is severely complicated by antibody ("inhibitor") formation. We previously found that oral delivery to hemophilic mice of cholera toxin B subunit-coagulation factor fusion proteins expressed in chloroplasts of transgenic plants suppressed inhibitor formation directed against factors VIII and IX and anaphylaxis against factor IX (FIX). This observation and the relatively high concentration of antigen in the chloroplasts prompted us to evaluate the underlying tolerance mechanisms. The combination of oral delivery of bioencapsulated FIX and intravenous replacement therapy induced a complex, interleukin-10 (IL-10)-dependent, antigen-specific systemic immune suppression of pathogenic antibody formation (immunoglobulin [Ig] 1/inhibitors, IgE) in hemophilia B mice. Tolerance induction was also successful in preimmune mice but required prolonged oral delivery once replacement therapy was resumed. Orally delivered antigen, initially targeted to epithelial cells, was taken up by dendritic cells throughout the small intestine and additionally by F4/80(+) cells in the duodenum. Consistent with the immunomodulatory responses, frequencies of tolerogenic CD103(+) and plasmacytoid dendritic cells were increased. Ultimately, latency-associated peptide expressing CD4(+) regulatory T cells (CD4(+)CD25(-)LAP(+) cells with upregulated IL-10 and transforming growth factor-β (TGF-β) expression) as well as conventional CD4(+)CD25(+) regulatory T cells systemically suppressed anti-FIX responses. © 2015 by The American Society of Hematology.

  3. Caspase-1 from Human Myeloid-Derived Suppressor Cells Can Promote T Cell-Independent Tumor Proliferation.

    Science.gov (United States)

    Zeng, Qi; Fu, Juan; Korrer, Michael; Gorbounov, Mikhail; Murray, Peter J; Pardoll, Drew; Masica, David L; Kim, Young J

    2018-05-01

    Immunosuppressive myeloid-derived suppressive cells (MDSCs) are characterized by their phenotypic and functional heterogeneity. To better define their T cell-independent functions within the tumor, sorted monocytic CD14 + CD11b + HLA-DR low/- MDSCs (mMDSC) from squamous cell carcinoma patients showed upregulated caspase-1 activity, which was associated with increased IL1β and IL18 expression. In vitro studies demonstrated that mMDSCs promoted caspase-1-dependent proliferation of multiple squamous carcinoma cell lines in both human and murine systems. In vivo , growth rates of B16, MOC1, and Panc02 were significantly blunted in chimeric mice adoptively transferred with caspase-1 null bone marrow cells under T cell-depleted conditions. Adoptive transfer of wild-type Gr-1 + CD11b + MDSCs from tumor-bearing mice reversed this antitumor response, whereas caspase-1 inhibiting thalidomide-treated MDSCs phenocopied the antitumor response found in caspase-1 null mice. We further hypothesized that MDSC caspase-1 activity could promote tumor-intrinsic MyD88-dependent carcinogenesis. In mice with wild-type caspase-1, MyD88-silenced tumors displayed reduced growth rate, but in chimeric mice with caspase-1 null bone marrow cells, MyD88-silenced tumors did not display differential tumor growth rate. When we queried the TCGA database, we found that caspase-1 expression is correlated with overall survival in squamous cell carcinoma patients. Taken together, our findings demonstrated that caspase-1 in MDSCs is a direct T cell-independent mediator of tumor proliferation. Cancer Immunol Res; 6(5); 566-77. ©2018 AACR . ©2018 American Association for Cancer Research.

  4. Induced Foxp3+ T cells colonising tolerated allografts exhibit the hypomethylation pattern typical of mature regulatory T cells.

    Directory of Open Access Journals (Sweden)

    Robert eHilbrands

    2016-04-01

    Full Text Available Regulatory T cells expressing the transcription factor Foxp3 require acquisition of a specific hypomethylation pattern to ensure optimal functional commitment, limited lineage plasticity and long-term maintenance of tolerance. A better understanding of the molecular mechanisms involved in the generation of these epigenetic changes in vivo will contribute to the clinical exploitation of Foxp3+Treg. Here we show that both in vitro and in vivo generated antigen specific Foxp3+Treg can acquire Treg-specific epigenetic characteristics and prevent skin graft rejection in an animal model.

  5. Activation of mitochondrial promoter PH-binding protein in a radio-resistant Chinese hamster cell strain associated with Bcl-2

    International Nuclear Information System (INIS)

    Roychoudhury, Paromita; Ghosh, Utpal; Bhattacharyya, Nitai P.; Chaudhuri, Keya

    2006-01-01

    The cellular response to ionizing radiation is mediated by a complex interaction of number of proteins involving different pathways. Previously, we have shown that up regulation of mitochondrial genes ND1, ND4, and COX1 transcribed from the heavy strand promoter (P H ) has been increased in a radio-resistant cell strain designated as M5 in comparison with the parental Chinese hamster V79 cells. These genes are also up regulated in Chinese hamster V79 cells VB13 that express exogenous human Bcl2. In the present study, the expression of the gene ND6 that is expressed from the light strand promoter (P L ) was found to be similar in both the cell lines, as determined by RT-PCR. To test the possibility that this differential expression of mitochondrial genes under these two promoters was mediated by differences in proteins' affinity to interact with these promoters, we have carried out electrophoretic mobility shift assay (EMSA) using mitochondrial cell extracts from these two cell lines. Our result of these experiments revealed that two different proteins formed complex with the synthetic promoters and higher amount of protein from M5 cell extracts interacted with the P H promoter in comparison to that observed with cell extracts from Chinese hamster V79 cells. The promoter-specific differential binding of proteins was also observed in VB13. These results showed that differential mitochondrial gene expression observed earlier in the radio-resistant M5 cells was due to enhanced interaction proteins with the promoters P H and mediated by the expression of Bcl2

  6. B cells promote obesity-associated periodontitis and oral pathogen-associated inflammation.

    Science.gov (United States)

    Zhu, Min; Belkina, Anna C; DeFuria, Jason; Carr, Jordan D; Van Dyke, Thomas E; Gyurko, Robert; Nikolajczyk, Barbara S

    2014-08-01

    Individuals with T2D and PD suffer significantly from the ability of one disease to intensify the other. Disease-associated inflammation is one mechanism thought to fuel this pathogenic feed-forward loop. Several lines of evidence indicate that proinflammatory B cells promote T2D and PD; thus, B cells are top candidates for a cell type that predisposes PD in T2D. To test directly the role of B cells in T2D-associated PD, we compared outcomes from oral Porphyromonas gingivalis challenge of lean WT or B cell-null mice with outcomes from mice that were obese and insulin-resistant before challenge. Obese WT mice responded to oral P. gingivalis challenge with significant periodontal bone loss, whereas obese B cell-null mice were protected completely from PD. By contrast, lean WT and B cell-null mice suffer similar periodontal bone loss in response to oral pathogen. B cells from obese/insulin-resistant hosts also support oral osteoclastogenesis and both oral and systemic production of inflammatory cytokines, including pro-osteoclastogenic TNF-α and MIP-2, an ortholog of human IL-8. B cells furthermore impact AT inflammation in obese, P. gingivalis-infected hosts. Taken together, these data show that fundamentally different mechanisms regulate PD in lean and obese hosts, with B cells able to promote PD only if the hosts are "primed" by obesity. These results justify more intense analysis of obesity-associated changes in B cells that predispose PD in human T2D. © 2014 Society for Leukocyte Biology.

  7. Breakdown of Immune Tolerance in Systemic Lupus Erythematosus by Dendritic Cells

    Science.gov (United States)

    Reihl, Alec M.

    2016-01-01

    Dendritic cells (DC) play an important role in the pathogenesis of systemic lupus erythematosus (SLE), an autoimmune disease with multiple tissue manifestations. In this review, we summarize recent studies on the roles of conventional DC and plasmacytoid DC in the development of both murine lupus and human SLE. In the past decade, studies using selective DC depletions have demonstrated critical roles of DC in lupus progression. Comprehensive in vitro and in vivo studies suggest activation of DC by self-antigens in lupus pathogenesis, followed by breakdown of immune tolerance to self. Potential treatment strategies targeting DC have been developed. However, many questions remain regarding the mechanisms by which DC modulate lupus pathogenesis that require further investigations. PMID:27034965

  8. Optimal fault-tolerant control strategy of a solid oxide fuel cell system

    Science.gov (United States)

    Wu, Xiaojuan; Gao, Danhui

    2017-10-01

    For solid oxide fuel cell (SOFC) development, load tracking, heat management, air excess ratio constraint, high efficiency, low cost and fault diagnosis are six key issues. However, no literature studies the control techniques combining optimization and fault diagnosis for the SOFC system. An optimal fault-tolerant control strategy is presented in this paper, which involves four parts: a fault diagnosis module, a switching module, two backup optimizers and a controller loop. The fault diagnosis part is presented to identify the SOFC current fault type, and the switching module is used to select the appropriate backup optimizer based on the diagnosis result. NSGA-II and TOPSIS are employed to design the two backup optimizers under normal and air compressor fault states. PID algorithm is proposed to design the control loop, which includes a power tracking controller, an anode inlet temperature controller, a cathode inlet temperature controller and an air excess ratio controller. The simulation results show the proposed optimal fault-tolerant control method can track the power, temperature and air excess ratio at the desired values, simultaneously achieving the maximum efficiency and the minimum unit cost in the case of SOFC normal and even in the air compressor fault.

  9. [Phenotype-based primary screening for drugs promoting neuronal subtype differentiation in embryonic stem cells with light microscope].

    Science.gov (United States)

    Gao, Yi-ning; Wang, Dan-ying; Pan, Zong-fu; Mei, Yu-qin; Wang, Zhi-qiang; Zhu, Dan-yan; Lou, Yi-jia

    2012-07-01

    To set up a platform for phenotype-based primary screening of drug candidates promoting neuronal subtype differentiation in embryonic stem cells (ES) with light microscope. Hanging drop culture 4-/4+ method was employed to harvest the cells around embryoid body (EB) at differentiation endpoint. Morphological evaluation for neuron-like cells was performed with light microscope. Axons for more than three times of the length of the cell body were considered as neuron-like cells. The compound(s) that promote neuron-like cells was further evaluated. Icariin (ICA, 10(-6)mol/L) and Isobavachin (IBA, 10(-7)mol/L) were selected to screen the differentiation-promoting activity on ES cells. Immunofluorescence staining with specific antibodies (ChAT, GABA) was used to evaluate the neuron subtypes. The cells treated with IBA showed neuron-like phenotype, but the cells treated with ICA did not exhibit the morphological changes. ES cells treated with IBA was further confirmed to be cholinergic and GABAergic neurons. Phenotypic screening with light microscope for molecules promoting neuronal differentiation is an effective method with advantages of less labor and material consuming and time saving, and false-positive results derived from immunofluorescence can be avoided. The method confirms that IBA is able to facilitate ES cells differentiating into neuronal cells, including cholinergic neurons and GABAergic neurons.

  10. Gamma-glutamylcyclotransferase promotes the growth of human glioma cells by activating Notch-Akt signaling

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Shang-Hang; Yu, Ning; Liu, Xi-Yao; Tan, Guo-Wei; Wang, Zhan-Xiang, E-mail: md_wzx7189@163.com

    2016-03-18

    Glioma as an aggressive type tumor is rapidly growing and has become one of the leading cause of cancer-related death worldwide. γ-Glutamylcyclotransferase (GGCT) has been shown as a diagnostic marker in various cancers. To reveal whether there is a correlation between GGCT and human glioma, GGCT expression in human glioma tissues and cell lines was first determined. We found that GGCT expression was up-regulated in human glioma tissues and cell lines. Further, we demonstrate that GGCT knockdown inhibits glioma cell T98G and U251 proliferation and colony formation, whereas GGCT overexpression leads to oppose effects. GGCT overexpression promotes the expression of Notch receptors and activates Akt signaling in glioma cells, and Notch-Akt signaling is activated in glioma tissues with high expression of GGCT. Finally, we show that inhibition of Notch-Akt signaling with Notch inhibitor MK-0752 blocks the effects of GGCT on glioma proliferation and colony formation. In conclusion, GGCT plays a critical role in glioma cell proliferation and may be a potential cancer therapeutic target. - Highlights: • GGCT expression is up-regulated in human glioma tissues and cell lines. • GGCT promotes glioma cell growth and colony formation. • GGCT promotes the activation of Notch-Akt signaling in glioma cells and tissues. • Notch inhibition blocks the role of GGCT in human glioma cells.

  11. Tafazzin (TAZ promotes the tumorigenicity of cervical cancer cells and inhibits apoptosis.

    Directory of Open Access Journals (Sweden)

    Mei Chen

    Full Text Available Tafazzin (TAZ is often aberrantly expressed in some cancers, including rectal cancer and thyroid neoplasms. However, the function of TAZ in cervical cancer cells remains unknown. This study aims to explore the expression and function of TAZ in cervical cancer cells. Here, we determined the expression of TAZ protein in normal cervical tissue (NC, n = 27, high-grade squamous intraepithelial lesions (HSIL, n = 26 and squamous cervical carcinoma (SCC, n = 41 by immunohistochemistry, the expression of TAZ protein gradually increased from NC to HSIL to SCC. TAZ was overexpressed or down-regulated in cervical cancer cells by stably transfecting a TAZ-expressing plasmid or a shRNA plasmid targeting TAZ. In vitro, the cell growth curves and MTT assays showed that TAZ may promote the growth and viability of cervical cancer cells. In vivo, xenografts experiment showed that TAZ may increase tumor-forming ability. The percentage of apoptosis cells analyzed by FACS and TUNEL assays consistently showed that TAZ inhibits apoptosis in cervical cancer cells. Furthermore, the Cleaved Caspase 9 and Cleaved Caspase 3 were down-regulated by TAZ in cervical cancer cells. Taken together, this study demonstrated that TAZ is overexpressed in cervical cancer and may promote tumorigenicity of cervical cancer cells and inhibit apoptosis.

  12. Clonal deletion: A mechanism of tolerance in mixed bone marrow chimeras

    International Nuclear Information System (INIS)

    Yu, J.C.; Webster, M.; Fox, I.J.

    1990-01-01

    The mechanism of antigen-specific immunologic unresponsiveness which results from lethal irradiation and mixed (syngeneic-allogeneic) bone marrow cell (BMC) reconstitution is unknown. To determine whether clonal deletion is the mechanism of tolerance in this model, monoclonal antibody (Mab) RR-4-4, specific for a T-cell receptor (V beta 6) reactive against the minor alloantigen MLsa, was employed. Six-week-old B10 mice (H-2b, Mlsb, Thyl.2) were tolerized to AKR antigens (H-2k, Mlsa, Thyl.1) by whole body irradiation (950 R) and iv infusion of T-cell-depleted (TCD) B10 BMC + non-TCD AKR BMC. Chimerism and antigen-specific tolerance were documented by flow microfluorometry (FMF), skin grafting, mixed lymphocyte reaction, and cell-mediated lympholysis. When tolerant B10 mice (n = 15) had accepted AKR skin grafts for greater than 100 days, these animals were studied for the presence of host V beta 6+ T cells using Mab RR-4-4. FMF revealed that 0-5% of host (B10) lymph node and spleen cells from chimeras were V beta 6+ while 15-20% of lymph node and spleen cells from control B10 mice expressed V beta 6. These data demonstrate that clonal deletion occurs in the lethal irradiation-mixed reconstitution model as evidenced by the near total elimination of Mlsa-reactive V beta 6+ T cells and suggest that it maybe a mechanism responsible for tolerance in adult mice

  13. PAI-1 expression and its regulation by promoter 4G/5G polymorphism in clear cell renal cell carcinoma.

    Science.gov (United States)

    Choi, Jung-Woo; Lee, Ju-Han; Park, Hong Seok; Kim, Young-Sik

    2011-10-01

    To characterise patients with high plasminogen activator inhibitor-1 (PAI-1) expression as oral PAI-1 antagonists are currently in preclinical trials, and to determine whether the PAI-1 promoter 4G/5G polymorphism regulates PAI-1 expression in clear cell renal cell carcinoma (CCRCC). PAI-1 expression was examined by immunohistochemistry in 69 CCRCC specimens. In addition, the promoter 4G/5G polymorphism was investigated by both allele-specific PCR and direct DNA sequencing. PAI-1 was overexpressed in 25/69 (36.2%) patients with CCRCC. PAI-1 staining was intense in tumour cells with a high Fuhrman nuclear grade and in spindle-shaped tumour cells. PAI-1 expression was significantly associated with older age at diagnosis (p=0.027), high nuclear grade (p5G and 31.9% (22/69) 5G/5G. The homozygous 4G/4G or 5G/5G group showed a tendency for a high nuclear grade (p=0.05) but the 4G/5G polymorphism was not related to other prognostic parameters. PAI-1 expression was poorly correlated with its promoter 4G/5G polymorphism (Spearman ρ=0.088). CCRCC with high PAI-1 expression is characterised by older age, high nuclear grade, advanced stage, distant metastasis and/or shortened disease-free survival. PAI-1 expression is not affected by the promoter 4G/5G polymorphism.

  14. Promoter motifs required for c-mpl gene expression induced by thrombopoietin in CMK cells.

    Science.gov (United States)

    Sunohara, Masataka; Sato, Iwao; Morikawa, Shigeru

    2017-11-30

    Thrombopoietin (TPO) and its receptor, c-Mpl, are the central regulators of megakaryocyte development and platelet production and are also crucial to regulate megakaryocytopoiesis. TPO remarkably elevated c-mpl promoter activity, while the protein kinase C (PKC) inhibitors, GF109203, H7 and Calphostin C, clearly reduced the steady level of its promoter activity.  In the present study, motifs crucial for c-mpl promoter activity induced by TPO treatment have been analyzed using a human megakaryoblastic cell line, CMK. Destruction of the -107Sp1 and the -57Sp1 sites in the c-mpl promoter enhancer region resulted in decrease of the promoter activity by 53.1% and 64.4%, respectively, and destruction of -69Ets and -28Ets elements dramatically decreased the promoter activity by 96.4% and 87.8%, respectively, while mutation of -77GATA moderately reduced the activity by 31.4%. The result was in agreement with our previous report that showed the crucial motifs in the c-mpl promoter for the promoter activity induced by PMA-treatment. This indicates that TPO-induced activation of the c-mpl promoter activity is fully modulated by transcription through a PKC-dependent pathway and the two Sp1 and two Ets motifs are crucial for the activation of the c-mpl promoter activity rather than a GATA motif in the c-mpl promoter of CMK cells.

  15. Performance Factors and Sulfur Tolerance of Metal Supported Solid Oxide Fuel Cells with Nanostructured Ni:GDC Infiltrated Anodes

    DEFF Research Database (Denmark)

    Nielsen, Jimmi; Sudireddy, Bhaskar Reddy; Hagen, Anke

    2016-01-01

    galvanostatic operation at a current load of 0.25 Acm−2. The results were compared with literature on the sulfur tolerance of conventional SOFC Ni/YSZ cermet anode. The comparison in terms of absolute cell resistance increase and relative anode polarization resistance increase indicates, that the nanostructured...... Ni:GDC MS-SOFC based anode is significantly more sulfur tolerant than the conventional Ni/YSZ cermet anode. Furthermore, it was shown that the believed extension of the electrochemical three-phase-boundary reaction zone in the presence of GDC must be very limited and cannot account for the higher...

  16. The MerR-like regulator BrlR confers biofilm tolerance by activating multidrug efflux pumps in Pseudomonas aeruginosa biofilms.

    Science.gov (United States)

    Liao, Julie; Schurr, Michael J; Sauer, Karin

    2013-08-01

    A defining characteristic of biofilms is antibiotic tolerance that can be up to 1,000-fold greater than that of planktonic cells. In Pseudomonas aeruginosa, biofilm tolerance to antimicrobial agents requires the biofilm-specific MerR-type transcriptional regulator BrlR. However, the mechanism by which BrlR mediates biofilm tolerance has not been elucidated. Genome-wide transcriptional profiling indicated that brlR was required for maximal expression of genes associated with antibiotic resistance, in particular those encoding the multidrug efflux pumps MexAB-OprM and MexEF-OprN. Chromatin immunoprecipitation (ChIP) analysis revealed a direct regulation of these genes by BrlR, with DNA binding assays confirming BrlR binding to the promoter regions of the mexAB-oprM and mexEF-oprN operons. Quantitative reverse transcriptase PCR (qRT-PCR) analysis further indicated BrlR to be an activator of mexAB-oprM and mexEF-oprN gene expression. Moreover, immunoblot analysis confirmed increased MexA abundance in cells overexpressing brlR. Inactivation of both efflux pumps rendered biofilms significantly more susceptible to five different classes of antibiotics by affecting MIC but not the recalcitrance of biofilms to killing by bactericidal agents. Overexpression of either efflux pump in a ΔbrlR strain partly restored tolerance of ΔbrlR biofilms to antibiotics. Expression of brlR in mutant biofilms lacking both efflux pumps partly restored antimicrobial tolerance of biofilms to wild-type levels. Our results indicate that BrlR acts as an activator of multidrug efflux pumps to confer tolerance to P. aeruginosa biofilms and to resist the action of antimicrobial agents.

  17. Transient HIF2A inhibition promotes satellite cell proliferation and muscle regeneration.

    Science.gov (United States)

    Xie, Liwei; Yin, Amelia; Nichenko, Anna S; Beedle, Aaron M; Call, Jarrod A; Yin, Hang

    2018-03-13

    The remarkable regeneration capability of skeletal muscle depends on coordinated proliferation and differentiation of satellite cells. The self-renewal of satellite cells is critical for long-term maintenance of muscle regeneration potential. Hypoxia profoundly affects the proliferation, differentiation, and self-renewal of cultured myoblasts. However, the physiological relevance of hypoxia and hypoxia signaling in satellite cells in vivo remains largely unknown. Here, we report that satellite cells are in an intrinsic hypoxic state in vivo and express hypoxia-inducible factor 2A (HIF2A). HIF2A promotes the stemness and long-term homeostatic maintenance of satellite cells by maintaining the quiescence, increasing the self-renewal and blocking the myogenic differentiation of satellite cells. HIF2A stabilization in satellite cells cultured under normoxia augmented their engraftment potential in regenerative muscle. Reversely, HIF2A ablation led to the depletion of satellite cells and the consequent regenerative failure in the long-term. In contrast, transient pharmacological inhibition of HIF2A accelerated muscle regeneration by increasing satellite cell proliferation and differentiation. Mechanistically, HIF2A induces the quiescence/self-renewal of satellite cells by binding the promoter of Spry1 gene and activating Spry1 expression. These findings suggest that HIF2A is a pivotal mediator of hypoxia signaling in satellite cells and may be therapeutically targeted to improve muscle regeneration.

  18. Y-27632, a ROCK Inhibitor, Promoted Limbal Epithelial Cell Proliferation and Corneal Wound Healing.

    Directory of Open Access Journals (Sweden)

    Chi-Chin Sun

    Full Text Available Transplantation of ex vivo cultured limbal epithelial cells is proven effective in restoring limbal stem cell deficiency. The present study aimed to investigate the promoting effect of Y-27632 on limbal epithelial cell proliferation. Limbal explants isolated from human donor eyes were expanded three weeks on culture dishes and outgrowth of epithelial cells was subsequently subcultured for in vitro experiments. In the presence of Y-27632, the ex vivo limbal outgrowth was accelerated, particularly the cells with epithelial cell-like morphology. Y-27632 dose-dependently promoted the proliferation of in vitro cultured human limbal epithelial cells as examined by phase contrast microscopy and luminescent cell-viability assay 30 hours after the treatment. The colony forming efficacy determined 7 days after the treatment was enhanced by Y-27632 also in a dose-dependent manner. The number of p63- or Ki67-positive cells was dose-dependently increased in Y-27632-treated cultures as detected by immunofluorescent staining and western blotanalysis. Cell cycle analysis by flow cytometric method revealed an increase in S-phase proliferating cells. The epithelial woundclosure rate was shown to be faster in experimental group received topical treatment withY-27632 than the sham control using a rat corneal wounding model. These resultsdemonstrate that Y-27632 can promote both the ex vivo and in vitro proliferation oflimbal epithelial cell proliferation. The in vivo enhanced epithelial wound healingfurther implies that the Y-27632 may act as a new strategy for treating limbal stem cell deficiency.

  19. Injury-activated glial cells promote wound healing of the adult skin in mice.

    Science.gov (United States)

    Parfejevs, Vadims; Debbache, Julien; Shakhova, Olga; Schaefer, Simon M; Glausch, Mareen; Wegner, Michael; Suter, Ueli; Riekstina, Una; Werner, Sabine; Sommer, Lukas

    2018-01-16

    Cutaneous wound healing is a complex process that aims to re-establish the original structure of the skin and its functions. Among other disorders, peripheral neuropathies are known to severely impair wound healing capabilities of the skin, revealing the importance of skin innervation for proper repair. Here, we report that peripheral glia are crucially involved in this process. Using a mouse model of wound healing, combined with in vivo fate mapping, we show that injury activates peripheral glia by promoting de-differentiation, cell-cycle re-entry and dissemination of the cells into the wound bed. Moreover, injury-activated glia upregulate the expression of many secreted factors previously associated with wound healing and promote myofibroblast differentiation by paracrine modulation of TGF-β signalling. Accordingly, depletion of these cells impairs epithelial proliferation and wound closure through contraction, while their expansion promotes myofibroblast formation. Thus, injury-activated glia and/or their secretome might have therapeutic potential in human wound healing disorders.

  20. Toleration and Coexistence in Conflicting Societies: Some Tensions and Implications for Education

    Science.gov (United States)

    Zembylas, Michalinos

    2011-01-01

    In this paper, the author shows that the issue of whether toleration promotes coexistence is controversial and therefore needs careful consideration in light of the complexities that are involved in understanding and teaching toleration in the schools of conflict and post-conflict societies. In particular, this paper offers a critique to the…