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Sample records for cell depletion immune

  1. Immunity to Schistosoma mansoni in congenitally athymic, irradiated and mast cell-depleted rats

    Energy Technology Data Exchange (ETDEWEB)

    Ford, M.J.; Bickle, Q.D.; Taylor, M.G.

    1987-04-01

    Immunity to Schistosoma mansoni was investigated in congenitally athymic (Nu/Nu) rats, irradiated rats and in mast cell-depleted rats. Nu/Nu rats failed to develop significant resistance following vaccination with irradiated cercariae, although Nu/Nu recipients of serum from vaccinated Fischer rats (VRS) manifested resistance comparable to heterozygous controls, suggesting that T-cells were required in the induction of resistance but were not involved in the efferent arm of antibody-dependent elimination. Radiosensitive cells (including eosinophils, basophils, neutrophils, lymphocytes and mast cells) were apparently not essential for the antibody-dependent elimination of lung or post-lung stages since irradiated (700-750 rad.) recipients of VRS manifested comparable degrees of resistance to unirradiated controls in spite of a greater than 85% reduction in total blood leucocyte counts after irradiation. Depletion of 99% of tissue mast cells by treatment of rats with Compound 48/80 had no significant effect on the attrition of a challenge infection in rats rendered immune by vaccination with irradiated cercariae or by transfer of VRS. However, there was a significant increase in worm recovery in unimmunized and mast cell-depleted or irradiated rats, indicating that mast cells and perhaps other radio-isotope sensitive cells may be involved in innate resistance.

  2. In Vitro Immune Toxicity of Depleted Uranium: Effects on Murine Macrophages, CD4+ T Cells, and Gene Expression Profiles

    OpenAIRE

    Wan, Bin; Fleming, James T.; Schultz, Terry W.; Sayler, Gary S.

    2005-01-01

    Depleted uranium (DU) is a by-product of the uranium enrichment process and shares chemical properties with natural and enriched uranium. To investigate the toxic effects of environmental DU exposure on the immune system, we examined the influences of DU (in the form of uranyl nitrate) on viability and immune function as well as cytokine gene expression in murine peritoneal macrophages and splenic CD4+ T cells. Macrophages and CD4+ T cells were exposed to various concentrations of DU, and cel...

  3. Increasing the immune activity of exosomes: the effect of miRNA-depleted exosome proteins on activating dendritic cell/cytokine-induced killer cells against pancreatic cancer* #

    OpenAIRE

    Que, Ri-sheng; Lin, Cheng; Ding, Guo-ping; WU, ZHENG-RONG; Cao, Li-ping

    2016-01-01

    Background: Tumor-derived exosomes were considered to be potential candidates for tumor vaccines because they are abundant in immune-regulating proteins, whereas tumor exosomal miRNAs may induce immune tolerance, thereby having an opposite immune function. Objective: This study was designed to separate exosomal protein and depleted exosomal microRNAs (miRNAs), increasing the immune activity of exosomes for activating dendritic cell/cytokine-induced killer cells (DC/CIKs) against pancreatic ca...

  4. YB-1 immunization combined with regulatory T-cell depletion induces specific T-cell responses that protect against neuroblastoma in the early stage

    Institute of Scientific and Technical Information of China (English)

    Jin Zheng; Ping Liu; Xiaofeng Yang

    2012-01-01

    Neuroblastoma is the most common extracranial solid cancer in childhood and the most common cancer in infancy.Currently,no effective clinical treatments are available for advanced neuroblastoma.In a previous study,we screened Y Box protein 1 (YB-1) as a potential neuroblastoma-associated antigen from sera of AGN2a-immunized mice by serological analysis of recombinant cDNA expression libraries technique.The aim of this study is to explore if YB-1 immunization in the context of Treg depletion could induce protective immune response against the neuroblastoma in mice.YB-1 was expressed and purified by pET-15b prokaryotic expression system.It was demonstrated that anti-YB-1 CD8+ T-cell responses could be induced by AGN2a immunization,and the strongest CD8+ T-cell responses against AGN2a were induced by YB-1-immunized mice in the context of Treg depletion compared with YB-1 only immunization group and control group.Importantly,the survival rate of mice treated with YB-1 immunization combined with Treg depletion was 80% when challenged by 1 × 104 AGN2a cells,significantly higher than that of mice immunized with YB-1 alone (P< 0.01).Furthermore,T-cell adoptive therapy showed that the neuroblastoma growth was inhibited when T cells or splenic cells from YB-1-immunized mice with Treg depletion were transferred to AGN2a bearing mice.Both CD4+ and CD8+ T cells were involved in the anti-neuroblastoma responses induced by YB-1immunization combined with Treg depletion.These results indicated that YB-1 immunization combined with Treg depletion could induce specific T-cell responses against neuroblastoma and could be a potential strategy for the prevention and treatment of neuroblastoma in the early stage.

  5. Monitoring of immune cell response to B cell depletion therapy and nerve root injury using SPIO enhanced MRI

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    Thorek, Daniel L.

    2009-12-01

    Magnetic resonance (MR) is a robust platform for non-invasive, high-resolution anatomical imaging. However, MR imaging lacks the requisite sensitivity and contrast for imaging at the cellular level. This represents a clinical impediment to greater diagnostic accuracy. Recent advances have allowed for the in vivo visualization of populations and even of individual cells using superparamagnetic iron oxide (SPIO) MR contrast agents. These nanoparticles, commonly manifested as a core of a single iron oxide crystal or cluster of crystals coated in a biocompatible shell, function to shorten proton relaxation times. In MR imaging these constructs locally dephase protons, resulting in a decrease in signal (hypointensity) localized to the region of accumulation of SPIO. In the context of immune cell imaging, SPIO can provide insight into the cellular migration patterns, trafficking, temporal dynamics and progression of diseases and their related pathological states. Furthermore, by visualizing the presence and activity of immune cells, SPIO-enabled cellular imaging can help evaluate the efficacy of therapy in immune disorders. This thesis examines the production, modification and application of SPIO in a range of in vitro and in vivo immune-response-relevant cellular systems. The role of different nanoparticle characteristics including diameter, surface charge and concentration are investigated in the labeling of T cells in culture. Following optimization of SPIO loading conditions for lymphocytes, the effect these particles have on the activation of primary B cells are elucidated. B cells are tracked using a variety of modalities, with and without the application of B cell depleting therapy. This is to evaluate the efficacy of SPIO as in vivo marker for B cell distribution. Unmodified SPIO were applied to monitor macrophage infiltration in a transient nerve root compression model, with implications for neck pain diagnosis and treatment. Nanoparticle accumulation and MR

  6. Depletion of CD25+CD4+T cells (Tregs) enhances the HBV-specific CD8+ T cell response primed by DNA immunization

    Institute of Scientific and Technical Information of China (English)

    Yoshihiro Furuichi; Hirotake Tokuyama; Satoshi Ueha; Makoto Kurachi; Fuminori Moriyasu; Kazuhiro Kakimi

    2005-01-01

    AIM: Persistent hepatitis B virus (HBV) infection is characterized by a weak CD8+ T cell response to HBV. Immunotherapeutic strategies that overcome tolerance and boost these suboptimal responses may facilitate viral clearance in chronically infected individuals. Therefore, we examined whether CD25+CD4+ regulatory T (Treg) cells might be involved in a inhibition of CD8+T cell priming or in the modulation of the magnitude of the'peak' antiviral CD8+ T cell response primed by DNA immunization. METHODS: B10.D2 mice were immunized once with plasmid pCMV-S. Mice received 500 μg of anti-CD25 mAb injected intraperitoneally 3 d before DNA immunization to deplete CD25+ cells. Induction of HBV-specific CD8+ T ceils in peripheral blood mononuclear cells (PBMCs) was measured by S28-39 peptide loaded DimerX staining and their function was analyzed by intracellular IFN-γ staining.RESULTS: DNA immunization induced HBV-specific CD8+ T cells. At the peak T cell response (d 10), 7.1±2.0% of CD8+ T cells were HBV-specific after DNA immunization, whereas 12.7±3.2% of CD8+ T cells were HBV-specific in Treg-depleted mice, suggesting that DNA immunization induced more antigen-specific CD8+ T cells in the absence of CD25+ Treg cells (n = 6, P<0.05). Similarly, fewer HBVspecific memory T cells were detected in the presence of these cells (1.3±0.4%) in comparison to Treg-depleted mice (2.6±0.9%) on d 30 after DNA immunization (n = 6, P<0.01). Both IFN-γ production and the avidity of the HBV-specific CD8+ T cell response to antigen were higher in HBV-specific CD8+ T cells induced in the absence of Treg cells.CONCLUSION: CD25+ Treg cells suppress priming and/or expansion of antigen-specific CD8+ T cells during DNA immunization and the peak CD8+ T cell response is enhanced by depleting this cell population. Furthermore, Treg cells appear to be involved in the contraction phase of the CD8+ T ceil response and may affect the quality of memory T cell pools. The elimination of Treg

  7. Daratumumab depletes CD38+ immune regulatory cells, promotes T-cell expansion, and skews T-cell repertoire in multiple myeloma.

    Science.gov (United States)

    Krejcik, Jakub; Casneuf, Tineke; Nijhof, Inger S; Verbist, Bie; Bald, Jaime; Plesner, Torben; Syed, Khaja; Liu, Kevin; van de Donk, Niels W C J; Weiss, Brendan M; Ahmadi, Tahamtan; Lokhorst, Henk M; Mutis, Tuna; Sasser, A Kate

    2016-07-21

    Daratumumab targets CD38-expressing myeloma cells through a variety of immune-mediated mechanisms (complement-dependent cytotoxicity, antibody-dependent cell-mediated cytotoxicity, and antibody-dependent cellular phagocytosis) and direct apoptosis with crosslinking. These mechanisms may also target nonplasma cells that express CD38, which prompted evaluation of daratumumab's effects on CD38-positive immune subpopulations. Peripheral blood (PB) and bone marrow (BM) from patients with relapsed/refractory myeloma from 2 daratumumab monotherapy studies were analyzed before and during therapy and at relapse. Regulatory B cells and myeloid-derived suppressor cells, previously shown to express CD38, were evaluated for immunosuppressive activity and daratumumab sensitivity in the myeloma setting. A novel subpopulation of regulatory T cells (Tregs) expressing CD38 was identified. These Tregs were more immunosuppressive in vitro than CD38-negative Tregs and were reduced in daratumumab-treated patients. In parallel, daratumumab induced robust increases in helper and cytotoxic T-cell absolute counts. In PB and BM, daratumumab induced significant increases in CD8(+):CD4(+) and CD8(+):Treg ratios, and increased memory T cells while decreasing naïve T cells. The majority of patients demonstrated these broad T-cell changes, although patients with a partial response or better showed greater maximum effector and helper T-cell increases, elevated antiviral and alloreactive functional responses, and significantly greater increases in T-cell clonality as measured by T-cell receptor (TCR) sequencing. Increased TCR clonality positively correlated with increased CD8(+) PB T-cell counts. Depletion of CD38(+) immunosuppressive cells, which is associated with an increase in T-helper cells, cytotoxic T cells, T-cell functional response, and TCR clonality, represents possible additional mechanisms of action for daratumumab and deserves further exploration. PMID:27222480

  8. Experimentally-induced immune activation in natural hosts of SIV induces significant increases in viral replication and CD4+ T cell depletion

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    Ribeiro, Ruy M [Los Alamos National Laboratory

    2008-01-01

    Chronically SIVagm-infected African green monkeys (AGMs) have a remarkably stable non-pathogenic disease course, with levels of immune activation in chronic SIVagm infection similar to those observed in uninfected monkeys and stable viral loads (VLs) for long periods of time. In vivo administration of lipopolysaccharide (LPS) or an IL-2/diphtheria toxin fusion protein (Ontak) to chronically SIVagm-infected AGMs triggered increases in immune activation and subsequently of viral replication and depletion of intestinal CD4{sup +} T cells. Our study indicates that circulating microbial products can increase viral replication by inducing immune activation and increasing the number of viral target cells, thus demonstrating that immune activation and T cell prolifeation are key factors in AIDS pathogenesis.

  9. Impact of ozone depletion on immune function

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    Jeevan, A.; Kripke, M.L. (Univ. of Texas, Houston, TX (United States). Dept. of Immunology)

    1993-06-01

    Depletion of stratospheric ozone is expected to lead to an increase in the amount of UV-B radiation present in sunlight. In addition to its well known ability to cause skin cancer, UV-B radiation has been shown to alter the immune system. The immune system is the body's primary defense mechanism against infectious diseases and protects against the development of certain types of cancer. Any impairment of immune function may jeopardize health by increasing susceptibility to infectious diseases, increasing the severity of infections, or delaying recovery for infections. In addition, impaired immune function can increase the incidence of certain cancers, particularly cancers of the skin. Research carried out with laboratory animals over the past 15 years has demonstrated that exposure of the skin to UV-B radiation can suppress certain types of immune responses. These include rejection of UV-induced skin cancers and melanomas, contact allergy reactions to chemicals, delayed-type hypersensitivity responses to microbial and other antigens, and phagocytosis and elimination of certain bacteria from lymphoid tissues. Recent studies with mycobacterial infection of mice demonstrated that exposure to UV-B radiation decreased the delayed hypersensitivity response to mycobacterial antigens and increased the severity of infection. In humans, UV-B radiation has also been shown to impair the contact allergy response. These studies demonstrate that UV radiation can decrease immune responses in humans and laboratory and raise the possibility that increased exposure to UV-B radiation could adversely affect human health by increasing the incidence or severity of certain infectious diseases.

  10. Depletion of CD4+CD25+ regulatory T cells can promote local immunity to suppress tumor growth in benzo[a]pyrene-induced forestomach carcinoma

    Institute of Scientific and Technical Information of China (English)

    Yi-Ling Chen; Jung-Hua Fang; Ming-Derg Lai; Yan-Shen Shan

    2008-01-01

    AIM: To elucidate the distribution of CD4+CD25+ regulatory T cells (Tregs) in different lymphoid tissues and its local enhancement on tumor growth before and after depletion of CD4+CD25+ Tregs.METHODS: Female ICR mice were gavaged with benzo[a]pyrene (BaP) to induce forestomach carcinoma. CD4+CD25+ Tregs were intraperitoneally depleted with monoclonal antibody PC61. These mice were divided into BaP-only, BaP+IgG, BaP+PC61, and control groups. The forestomach of mice was dissected for histological analysis, and tunnel test was performed for apoptosis of tumor cells. CD4+CD25+ Tregs were sorted from different lymphoid tissues and expression of Foxp3, IL-10, and chemokine receptors was analyzed by flow cytometry, semi-quantitative and real-time polymerase chain reaction.RESULTS: The mice gavaged with only BaP showed increased forestomach papilloma and carcinoma at wk 16 and 32. The proportion of CD4+CD25+ Tregs was significantly higher in peri-stomach regional lymph nodes than in other lymphoid tissues. These CD4+CD25+ Tregs in regional lymph nodes expressed higher levels of Foxp3 and IL-10, enriched in the CD62L-subset, and CCR1 and CCR5 chemokine receptors. In mice gavaged with BaP+PC61, the number of tumor nodules and tumor volume decreased significantly with massive infiltrating cells and apoptosis of tumor cells. In the draining regional lymph nodes, the number of CD4+CD25+ Tregs also decreased significantly.CONCLUSION: Inducible and activated CD4+CD25+ Tregs in the draining regional lymph nodes suppress host local immunity during tumor growth. Depletion of CD4+CD25+ Tregs can promote host local immunity to suppress tumor growth.

  11. Regulatory T-cell depletion in the gut caused by integrin β7 deficiency exacerbates DSS colitis by evoking aberrant innate immunity.

    Science.gov (United States)

    Zhang, H L; Zheng, Y J; Pan, Y D; Xie, C; Sun, H; Zhang, Y H; Yuan, M Y; Song, B L; Chen, J F

    2016-03-01

    Integrin α4β7 controls lymphocyte trafficking into the gut and has essential roles in inflammatory bowel disease (IBD). The α4β7-blocking antibody vedolizumab is approved for IBD treatment; however, high dose of vedolizumab aggravates colitis in a small percentage of patients. Herein, we show that integrin β7 deficiency results in colonic regulatory T (Treg) cell depletion and exacerbates dextran sulfate sodium (DSS) colitis by evoking aberrant innate immunity. In DSS-treated β7-deficient mice, the loss of colonic Treg cells induces excessive macrophage infiltration in the colon via upregulation of colonic epithelial intercellular adhesion molecule 1 and increases proinflammatory cytokine expression, thereby exacerbating DSS-induced colitis. Moreover, reconstitution of the colonic Treg cell population in β7-deficient mice suppresses aberrant innate immune response in the colon and attenuates DSS colitis. Thus, integrin α4β7 is essential for suppression of DSS colitis as it regulates the colonic Treg cell population and innate immunity.

  12. Daratumumab depletes CD38+ immune-regulatory cells, promotes T-cell expansion, and skews T-cell repertoire in multiple myeloma

    DEFF Research Database (Denmark)

    Krejcik, Jakub; Casneuf, Tineke; Nijhof, Inger S;

    2016-01-01

    Daratumumab targets CD38-expressing myeloma cells through a variety of immune-mediated mechanisms (complement-dependent cytotoxicity, antibody-dependent cell-mediated cytotoxicity, and antibody-dependent cellular phagocytosis) and direct apoptosis with cross-linking. These mechanisms may also...... target non-plasma cells that express CD38, which prompted evaluation of daratumumab's effects on CD38-positive immune subpopulations. Peripheral blood (PB) and bone marrow (BM) from patients with relapsed/refractory myeloma from two daratumumab monotherapy studies were analyzed before and during therapy...... and at relapse. Regulatory B cells (Bregs) and myeloid-derived suppressor cells (MDSCs), previously shown to express CD38, were evaluated for immunosuppressive activity and daratumumab sensitivity in the myeloma setting. A novel subpopulation of regulatory T cells (Tregs) expressing CD38 was identified...

  13. Mechanisms of immunological eradication of a syngeneic guinea pig tumor. II. Effect of methotrexate treatment and T cell depletion of the recipient on adoptive immunity

    International Nuclear Information System (INIS)

    The influence of methotrexate on the development of immunity to the line 10 hepatoma was studied in guinea pigs. Chronic methotrexate treatment had no apparent effect on the ability of immune guinea pigs to suppress the growth of inoculated tumor cells. In contrast, the same methotrexate regimen inhibited the development of tumor immunity if started before the 8th day after immunization with a vaccine containing viable line 10 cells admixed with Bacillus Calmette-Guerin (BCG) cell walls. Thus, methotrexate selectively inhibited the afferent limb of the immune response. In adoptive transfer experiments, methotrexate-treated recipient guinea pigs were capable of being passively sensitized with immune spleen cells, indicating that the primary cell-mediated immune response of the recipient was not required for adoptive immunity. The contribution of recipient T cells in adoptive immunity was further investigated in guinea pigs deleted of T cells by thymectomy, irradiation, and bone marrow reconstitution. Despite demonstrable deficiency in T lymphocyte reactions, B animals were fully capable of rejecting tumors after transfer of immune cells. These results suggest that the expression of adoptive immunity was independent of recipient T cell participation. In addition, sublethal irradiation of immune spleen cells prior to adoptive transfer abolished their efficacy. Proliferation of transferred immune cells in the recipient may be essential for expression of adoptive immunity

  14. B cell depletion in HIV-1 subtype A infected Ugandan adults: relationship to CD4 T cell count, viral load and humoral immune responses.

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    Peter Oballah

    Full Text Available To better understand the nature of B cell dysfunctions in subjects infected with HIV-1 subtype A, a rural cohort of 50 treatment-naïve Ugandan patients chronically infected with HIV-1 subtype A was studied, and the relationship between B cell depletion and HIV disease was assessed. B cell absolute counts were found to be significantly lower in HIV-1+ patients, when compared to community matched negative controls (p<0.0001. HIV-1-infected patients displayed variable functional and binding antibody titers that showed no correlation with viral load or CD4+ T cell count. However, B cell absolute counts were found to correlate inversely with neutralizing antibody (NAb titers against subtype A (p = 0.05 and subtype CRF02_AG (p = 0.02 viruses. A positive correlation was observed between subtype A gp120 binding antibody titers and NAb breadth (p = 0.02 and mean titer against the 10 viruses (p = 0.0002. In addition, HIV-1 subtype A sera showed preferential neutralization of the 5 subtype A or CRF02_AG pseudoviruses, as compared with 5 pseudoviruses from subtypes B, C or D (p<0.001. These data demonstrate that in patients with chronic HIV-1 subtype A infection, significant B cell depletion can be observed, the degree of which does not appear to be associated with a decrease in functional antibodies. These findings also highlight the potential importance of subtype in the specificity of cross-clade neutralization in HIV-1 infection.

  15. CD3+CD8+CD161high Tc17 cells are depleted in HIV-Infection and related to the level of immune reconstitution

    OpenAIRE

    Nielsen, S; H Ullum; J Gaardbo; H Hartling

    2012-01-01

    Purpose: The existence of CD8+cells with pro-inflammatory properties referred to as Tc17 cells has recently been acknowledged. While it is evident that CD4+pro-inflammatory IL-17-producing Th17 cells are important in the regulation of chronic viral infections, the role of Tc17 cells is largely unknown. Tc17 cells are characterized by expression of high levels of CD161 (CD161high). We hypothesized that Tc17 cells are involved in immune regulation in HIV- infection. Methods: 67 HIV-infected pat...

  16. CD20+ B Cell Depletion in Systemic Autoimmune Diseases: Common Mechanism of Inhibition or Disease-Specific Effect on Humoral Immunity?

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    Panagiotis Pateinakis

    2014-01-01

    Full Text Available Autoimmunity remains a complex physiologic deviation, enabled and perpetuated by a variety of interplayers and pathways. Simplistic approaches, targeting either isolated end-effectors of more centrally placed interactors of these mechanisms, are continuously tried in an effort to comprehend and halt cascades with potential disabling and deleterious effects in the affected individuals. This review focuses on theoretical and clinically proved effects of rituximab-induced CD20+ B cell depletion on different systemic autoimmune diseases and extrapolates on pathogenetic mechanisms that may account for different interindividual or interdisease responses.

  17. Apoptosis and T cell depletion during feline infectious peritonitis

    NARCIS (Netherlands)

    Horzinek, M.C.; Haagmans, B.L.; Egberink, H.F.

    1996-01-01

    Cats that have succumbed to feline infectious peritonitis, an immune- mediated disease caused by variants of feline coronaviruses, show apoptosis and T-cell depletion in their lymphoid organs. The ascitic fluid that develops in the course of the condition causes apoptosis in vitro but only in activa

  18. CD3+CD8+CD161high Tc17 cells are depleted in HIV-Infection and related to the level of immune reconstitution

    Directory of Open Access Journals (Sweden)

    S Nielsen

    2012-11-01

    Full Text Available Purpose: The existence of CD8+cells with pro-inflammatory properties referred to as Tc17 cells has recently been acknowledged. While it is evident that CD4+pro-inflammatory IL-17-producing Th17 cells are important in the regulation of chronic viral infections, the role of Tc17 cells is largely unknown. Tc17 cells are characterized by expression of high levels of CD161 (CD161high. We hypothesized that Tc17 cells are involved in immune regulation in HIV- infection. Methods: 67 HIV-infected patients were included in a cross-sectional study. All patients had nadir CD4 counts<200 cells/µL, fully suppressed viral loads, and had been on cART for at least 2 years. Three groups were defined: Immunological Non Responders (INR, CD4 counts<200 cells/µL, Intermediate Responders (IR, CD4 counts 200–500 cells/µL, and Responders (RES, CD4 counts>500 cells/µL. Percentages of CD8+cells expressing CD3+CD8+CD161high were evaluated using flow cytometry. Additionally, Production of IL-17 in phytohaemagglutinin(PHA-stimulated peripheral blood was determined by Luminex. For statistics Kruskall Wallis test followed by Mann-Whitney U test was used. Data are given as medians. Summary of results: INR had lower levels of Tc17 cells compared to IR, RES and controls (0.4%, 1.0%, 2.1%, 6.1%, p values<0.05. All HIV-infected patients had lower levels than controls (p values<0.0001. Furthermore, all HIV-infected patients displayed lower production of IL-17 in peripheral blood compared to controls (p values<0.001.

  19. Haploidentical bone marrow transplantation without T-cell depletion.

    Science.gov (United States)

    Chang, Ying-Jun; Huang, Xiao-Jun

    2012-12-01

    Approaches for haploidentical bone marrow transplantation (BMT) without T-cell depletion have been designed using new transplant strategies, including anti-thymocyte globulin (ATG) preparative regimens, granulocyte colony-stimulating factor-primed grafts, post-transplantation rapamycin, or high-dose cyclophosphamide (Cy) in combination with other immunosuppressive agents for graft-versus-host disease (GVHD) prophylaxis. These strategies ensured fast hematologic engraftment across the human leukocyte antigen (HLA) barrier with an acceptable incidence of GVHD. Long-term follow-up results from different transplant centers suggest that unmanipulated transplantation may provide an alternative strategy in the haploidentical setting without requiring the technical expertise and cost of ex vivo T-cell depletion. This review discusses immune reconstitution and factors associated with clinical outcomes following unmanipulated haploidentical hematopoietic stem cell transplantation (HSCT), and compares outcomes between unmanipulated haploidentical transplant versus HLA-matched sibling donor (MSD) transplantation, HLA-matched unrelated donor (MUD) transplantation, or unrelated double umbilical cord blood (dUCB) transplantation. Advantages and disadvantages of unmanipulated haploidentical HSCT and strategies to improve outcome after haploidentical BMT without ex vivo T-cell depletion are discussed. PMID:23206842

  20. Depleted uranium disturbs immune parameters in zebrafish, Danio rerio: an ex vivo/in vivo experiment.

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    Gagnaire, Béatrice; Bado-Nilles, Anne; Sanchez, Wilfried

    2014-10-01

    In this study, we investigated the effects of depleted uranium (DU), the byproduct of nuclear enrichment of uranium, on several parameters related to defence system in the zebrafish, Danio rerio, using flow cytometry. Several immune cellular parameters were followed on kidney leucocytes: cell proportion, cell mortality, phagocytosis activity and associated oxidative burst and lysosomal membrane integrity (LMI). Effects of DU were tested ex vivo after 17 h of contact between DU and freshly isolated leucocytes from 0 to 500 µg DU/L. Moreover, adult zebrafish were exposed in vivo during 3 days at 20 and 250 µg DU/L. Oxidative burst results showed that DU increased reactive oxygen species (ROS) basal level and therefore reduced ROS stimulation index in both ex vivo and in vivo experiments. ROS PMA-stimulated level was also increased at 250 µg DU/L in vivo only. Furthermore, a decrease of LMI was detected after in vivo experiments. Cell mortality was also decreased at 20 µg DU/L in ex vivo experiment. However, phagocytosis activity was not modified in both ex vivo and in vivo experiments. A reduction of immune-related parameters was demonstrated in zebrafish exposed to DU. DU could therefore decrease the ability of fish to stimulate its own immune system which could, in turn, enhance the susceptibility of fish to infection. These results encourage the development and the use of innate immune analysis by flow cytometry in order to understand the effects of DU and more generally radionuclides on fish immune system and response to infectious diseases. PMID:24723161

  1. In vitro immune functions in thiamine-replete and -depleted lake trout (Salvelinus namaycush)

    Science.gov (United States)

    Ottinger, Christopher A.; Honeyfield, Dale C.; Densmore, Christine L.; Iwanowicz, Luke R.

    2014-01-01

    In this study we examined the impacts of in vivo thiamine deficiency on lake trout leukocyte function measured in vitro. When compared outside the context of individual-specific thiamine concentrations no significant differences were observed in leukocyte bactericidal activity or in concanavalin A (Con A), and phytohemagglutinin-P (PHA-P) stimulated leukocyte proliferation. Placing immune functions into context with the ratio of in vivo liver thiamine monophosphate (TMP – biologically inactive form) to thiamine pyrophosphate (TPP – biologically active form) proved to be the best indicator of thiamine depletion impacts as determined using regression modeling. These observed relationships indicated differential effects on the immune measures with bactericidal activity exhibiting an inverse relationship with TMP to TPP ratios, Con A stimulated mitogenesis exhibiting a positive relationship with TMP to TPP ratios and PHA-P stimulated mitogenesis exhibiting no significant relationships. In addition, these relationships showed considerable complexity which included the consistent observation of a thiamine-replete subgroup with characteristics similar to those seen in the leukocytes from thiamine-depleted fish. When considered together, our observations indicate that lake trout leukocytes experience cell-type specific impacts as well as an altered physiologic environment when confronted with a thiamine-limited state.

  2. T cell depleted haploidentical transplantation: positive selection

    Directory of Open Access Journals (Sweden)

    Franco Aversa

    2011-06-01

    Full Text Available Interest in mismatched transplantation arises from the fact that a suitable one-haplotype mismatched donor is immediately available for virtually all patients, particularly for those who urgently need an allogenic transplant. Work on one haplotype-mismatched transplants has been proceeding for over 20 years all over the world and novel transplant techniques have been developed. Some centres have focused on the conditioning regimens and post transplant immune suppression; others have concentrated on manipulating the graft which may be a megadose of extensively T celldepleted or unmanipulated progenitor cells. Excellent engraftment rates are associated with a very low incidence of acute and chronic GVHD and regimen-related mortality even in patients who are over 50 years old. Overall, event-free survival and transplant-related mortality compare favourably with reports on transplants from sources of stem cells other than the matched sibling.

  3. Depletion of dendritic cells enhances innate anti-bacterial host defense through modulation of phagocyte homeostasis.

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    Stella E Autenrieth

    2012-02-01

    Full Text Available Dendritic cells (DCs as professional antigen-presenting cells play an important role in the initiation and modulation of the adaptive immune response. However, their role in the innate immune response against bacterial infections is not completely defined. Here we have analyzed the role of DCs and their impact on the innate anti-bacterial host defense in an experimental infection model of Yersinia enterocolitica (Ye. We used CD11c-diphtheria toxin (DT mice to deplete DCs prior to severe infection with Ye. DC depletion significantly increased animal survival after Ye infection. The bacterial load in the spleen of DC-depleted mice was significantly lower than that of control mice throughout the infection. DC depletion was accompanied by an increase in the serum levels of CXCL1, G-CSF, IL-1α, and CCL2 and an increase in the numbers of splenic phagocytes. Functionally, splenocytes from DC-depleted mice exhibited an increased bacterial killing capacity compared to splenocytes from control mice. Cellular studies further showed that this was due to an increased production of reactive oxygen species (ROS by neutrophils. Adoptive transfer of neutrophils from DC-depleted mice into control mice prior to Ye infection reduced the bacterial load to the level of Ye-infected DC-depleted mice, suggesting that the increased number of phagocytes with additional ROS production account for the decreased bacterial load. Furthermore, after incubation with serum from DC-depleted mice splenocytes from control mice increased their bacterial killing capacity, most likely due to enhanced ROS production by neutrophils, indicating that serum factors from DC-depleted mice account for this effect. In summary, we could show that DC depletion triggers phagocyte accumulation in the spleen and enhances their anti-bacterial killing capacity upon bacterial infection.

  4. Effect of arginase II on L-arginine depletion and cell growth in murine cell lines of renal cell carcinoma

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    Patterson John R

    2008-09-01

    Full Text Available Abstract Background L-arginine is the common substrate for the two isoforms of arginase. Arginase I, highly expressed in the liver and arginase II mainly expressed in the kidney. Arginase I-producing myeloid derived suppressor cells have been shown to inhibit T-cell function by the depletion of L-arginine. On the other hand, arginase II has been detected in patients with cancer and is thought to metabolize L-arginine to L-ornithine needed to sustain rapid tumor growth; however its role in L-arginine depletion is unclear. Thus, in tumor biology, L-arginine metabolism may play a dual role in tumor growth and in the induction of T cell dysfunction. Therefore, we studied in murine renal cell carcinoma (RCC cell lines, the effect of arginase II on tumor cell proliferation and L-arginine depletion. The effect of arginase inhibitors on cell proliferation was also tested. Methods Three murine renal cell carcinoma (mRCC cell lines were tested for the presence of arginase. nor-NOHA, an arginase inhibitor was used to substantiate the effect of arginase on cell growth and L-arginine depletion. Amino acid levels were tested by HPLC. Results Our results show that mRCC cell lines express only arginase II and were able to deplete L-arginine from the medium. Cell growth was independent of the amount of arginase activity expressed by the cells. nor-NOHA significantly (P = 0.01 reduced arginase II activity and suppressed cell growth in cells exhibiting high arginase activity. The depletion of L-arginine by mRCC induced the decrease expression of CD3ζ a key element for T-cell function. Conclusion The results of this study show for the first time that arginase II produced by RCC cell lines depletes L-arginine resulting in decreased expression of CD3ζ. These results indicate that RCC cell lines expressing arginase II can modulate the L-arginine metabolic pathway to regulate both cell growth and T-cell function. Blocking arginase may lead to a decrease in RCC cell

  5. Germinal center B cell depletion diminishes CD4+ follicular T helper cells in autoimmune mice.

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    Isharat Yusuf

    Full Text Available BACKGROUND: Continuous support from follicular CD4(+ T helper (Tfh cells drives germinal center (GC responses, which last for several weeks to produce high affinity memory B cells and plasma cells. In autoimmune Sle1 and NZB/W F1 mice, elevated numbers of Tfh cells persist, promoting the expansion of self-reactive B cells. Expansion of circulating Tfh like cells have also been described in several autoimmune diseases. Although, the signals required for Tfh differentiation have now been well described, the mechanisms that sustain the maintenance of fully differentiated Tfh are less understood. Recent data demonstrate a role for GC B cells for Tfh maintenance after protein immunization. METHODS AND FINDING: Given the pathogenic role Tfh play in autoimmune disease, we explored whether B cells are required for maintenance of autoreactive Tfh. Our data suggest that the number of mature autoreactive Tfh cells is controlled by GC B cells. Depletion of B cells in Sle1 autoimmune mice leads to a dramatic reduction in Tfh cells. In NZB/W F1 autoimmune mice, similar to the SRBC immunization model, GC B cells support the maintenance of mature Tfh, which is dependent mainly on ICOS. The CD28-associated pathway is dispensable for Tfh maintenance in SRBC immunized mice, but is required in the spontaneous NZB/W F1 model. CONCLUSION: These data suggest that mature Tfh cells require signals from GC B cells to sustain their optimal numbers and function in both autoimmune and immunization models. Thus, immunotherapies targeting B cells in autoimmune disease may affect pathogenic Tfh cells.

  6. In vivo T cell depletion regulates resistance and morbidity in murine schistosomiasis

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    Phillips, S.M.; Linette, G.P.; Doughty, B.L.; Byram, J.E.; Von Lichtenberg, F.

    1987-08-01

    These studies assessed the roles of subpopulations of T lymphocytes in inducing and modulating resistance to schistosomiasis and thereby influencing subsequent morbidity. C57BL/6 mice were depleted in vivo of Lyt-1+, Lyt-2+, and L3T4+ cells by the daily administration of monoclonal antibodies. The development of protective immunity, induced by exposure to irradiated Schistosoma mansoni cercariae as expressed in depleted animals, was compared to that demonstrated in undepleted, normal, and congenitally athymic C57BL/6 mice. The development of morbidity was determined by spleen weight, portal pressure and reticuloendothelial system activity. The results indicated that depletion of specific subpopulations of T lymphocytes minimally affected the primary development of parasites; however, depletion strongly influenced the development of resistance to the parasite and subsequent morbidity due to infection. Depletion of T lymphocytes by anti-Lyt-1+ or anti-L3T4+ antibody decreased the development of resistance, antibody and delayed-type hypersensitivity directed against schistosome antigens. Morbidity due to disease was increased. Depletion of Lyt-2+ cells produced opposite changes with augmented resistance and reduced morbidity. Congenitally athymic mice developed minimal resistance and morbidity. Moreover, resistance was inversely related to the morbidity shown by a given animal. These studies indicate that the development of protective immunity to S. mansoni cercariae is regulated by discrete subpopulations of T lymphocytes. The feasibility of decreasing morbidity by increasing specific immunologically mediated resistance is suggested.

  7. Plasmacytoid dendritic cells promote HIV-1-induced group 3 innate lymphoid cell depletion.

    Science.gov (United States)

    Zhang, Zheng; Cheng, Liang; Zhao, Juanjuan; Li, Guangming; Zhang, Liguo; Chen, Weiwei; Nie, Weiming; Reszka-Blanco, Natalia J; Wang, Fu-Sheng; Su, Lishan

    2015-09-01

    Group 3 innate lymphoid cells (ILC3s) have demonstrated roles in promoting antibacterial immunity, maintaining epithelial barrier function, and supporting tissue repair. ILC3 alterations are associated with chronic inflammation and inflammatory disease; however, the characteristics and relevant regulatory mechanisms of this cell population in HIV-1 infection are poorly understood due in part to a lack of a robust model. Here, we determined that functional human ILC3s develop in lymphoid organs of humanized mice and that persistent HIV-1 infection in this model depletes ILC3s, as observed in chronic HIV-1-infected patients. In HIV-1-infected mice, effective antiretroviral therapy reversed the loss of ILC3s. HIV-1-dependent reduction of ILC3s required plasmacytoid dendritic cells (pDCs), IFN-I, and the CD95/FasL pathway, as targeted depletion or blockade of these prevented HIV-1-induced ILC3 depletion in vivo and in vitro, respectively. Finally, we determined that HIV-1 infection induces CD95 expression on ILC3s via a pDC- and IFN-I-dependent mechanism that sensitizes ILC3s to undergo CD95/FasL-mediated apoptosis. We conclude that chronic HIV-1 infection depletes ILC3s through pDC activation, induction of IFN-I, and CD95-mediated apoptosis.

  8. Sedimentation rapidly induces an immune response and depletes energy stores in a hard coral

    Science.gov (United States)

    Sheridan, C.; Grosjean, Ph.; Leblud, J.; Palmer, C. V.; Kushmaro, A.; Eeckhaut, I.

    2014-12-01

    High sedimentation rates have been linked to reduced coral health within multiple systems; however, whether this is a direct result of compromised coral immunity has not been previously investigated. The potential effects of sedimentation on immunity of the hard coral Montipora patula were examined by comparing physiological responses of coral fragments inoculated with sterilized marine sediments and those under control conditions. Sediments were collected from terrestrial runoff-affected reefs in SW Madagascar and applied cyclically for a total of 24 h at a rate observed during precipitation-induced sedimentation events. Coral health was determined 24 h after the onset of the sedimentation stress through measuring metabolic proxies of O2 budget and lipid ratios. Immune response of the melanin synthesis pathway was measured by quantifying phenoloxidase activity and melanin deposits. Sedimentation induced both immune and metabolic responses in M. patula. Both phenoloxidase activity and melanin deposition were significantly higher in the sediment treatment compared to controls, indicating an induced immune response. Sediment-treated corals also showed a tendency towards increased respiration (during the night) and decreased photosynthesis (during the day) and a significant depletion of energy reserves as compared to controls. These data highlight that short-term (24 h) sedimentation, free of live microorganisms, compromises the health of M. patula. The energetically costly immune response, potentially elicited by residual endotoxins and other inflammatory particles associated with the sterile sediments, likely contributes to the energy depletion. Overall, exposure to sedimentation adversely affects coral health and continued exposure may lead to resource depletion and an increased susceptibility to disease.

  9. Asymmetric spindle pole formation in CPAP-depleted mitotic cells.

    Science.gov (United States)

    Lee, Miseon; Chang, Jaerak; Chang, Sunghoe; Lee, Kyung S; Rhee, Kunsoo

    2014-02-21

    CPAP is an essential component for centriole formation. Here, we report that CPAP is also critical for symmetric spindle pole formation during mitosis. We observed that pericentriolar material between the mitotic spindle poles were asymmetrically distributed in CPAP-depleted cells even with intact numbers of centrioles. The length of procentrioles was slightly reduced by CPAP depletion, but the length of mother centrioles was not affected. Surprisingly, the young mother centrioles of the CPAP-depleted cells are not fully matured, as evidenced by the absence of distal and subdistal appendage proteins. We propose that the selective absence of centriolar appendages at the young mother centrioles may be responsible for asymmetric spindle pole formation in CPAP-depleted cells. Our results suggest that the neural stem cells with CPAP mutations might form asymmetric spindle poles, which results in premature initiation of differentiation.

  10. Effects of B Cell Depletion on Early Mycobacterium tuberculosis Infection in Cynomolgus Macaques.

    Science.gov (United States)

    Phuah, Jiayao; Wong, Eileen A; Gideon, Hannah P; Maiello, Pauline; Coleman, M Teresa; Hendricks, Matthew R; Ruden, Rachel; Cirrincione, Lauren R; Chan, John; Lin, Philana Ling; Flynn, JoAnne L

    2016-05-01

    Although recent studies in mice have shown that components of B cell and humoral immunity can modulate the immune responses against Mycobacterium tuberculosis, the roles of these components in human and nonhuman primate infections are unknown. The cynomolgus macaque (Macaca fascicularis) model of M. tuberculosis infection closely mirrors the infection outcomes and pathology in human tuberculosis (TB). The present study used rituximab, an anti-CD20 antibody, to deplete B cells in M. tuberculosis-infected macaques to examine the contribution of B cells and humoral immunity to the control of TB in nonhuman primates during the acute phase of infection. While there was no difference in the overall pathology, disease profession, and clinical outcome between the rituximab-treated and untreated macaques in acute infection, analyzing individual granulomas revealed that B cell depletion resulted in altered local T cell and cytokine responses, increased bacterial burden, and lower levels of inflammation. There were elevated frequencies of T cells producing interleukin-2 (IL-2), IL-10, and IL-17 and decreased IL-6 and IL-10 levels within granulomas from B cell-depleted animals. The effects of B cell depletion varied among granulomas in an individual animal, as well as among animals, underscoring the previously reported heterogeneity of local immunologic characteristics of tuberculous granulomas in nonhuman primates. Taken together, our data clearly showed that B cells can modulate the local granulomatous response in M. tuberculosis-infected macaques during acute infection. The impact of these alterations on disease progression and outcome in the chronic phase remains to be determined. PMID:26883591

  11. CD4+ T Cell Depletion in Human Immunodeficiency Virus (HIV Infection: Role of Apoptosis

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    Angelita Rebollo

    2011-05-01

    Full Text Available Human immunodeficiency virus (HIV infection is principally a mucosal disease and the gastrointestinal (GI tract is the major site of HIV replication. Loss of CD4+ T cells and systemic immune hyperactivation are the hallmarks of HIV infection. The end of acute infection is associated with the emergence of specific CD4+ and CD8+ T cell responses and the establishment of a chronic phase of infection. Abnormal levels of immune activation and inflammation persist despite a low steady state level of viremia. Although the causes of persistent immune hyperactivation remain incompletely characterized, physiological alterations of gastrointestinal tract probably play a major role. Failure to restore Th17 cells in gut-associated lymphoid tissues (GALT might impair the recovery of the gut mucosal barrier. This review discusses recent advances on understanding the contribution of CD4+ T cell depletion to HIV pathogenesis.

  12. CD4+ T Cell Depletion in Human Immunodeficiency Virus (HIV) Infection: Role of Apoptosis

    Science.gov (United States)

    Février, Michèle; Dorgham, Karim; Rebollo, Angelita

    2011-01-01

    Human immunodeficiency virus (HIV) infection is principally a mucosal disease and the gastrointestinal (GI) tract is the major site of HIV replication. Loss of CD4+ T cells and systemic immune hyperactivation are the hallmarks of HIV infection. The end of acute infection is associated with the emergence of specific CD4+ and CD8+ T cell responses and the establishment of a chronic phase of infection. Abnormal levels of immune activation and inflammation persist despite a low steady state level of viremia. Although the causes of persistent immune hyperactivation remain incompletely characterized, physiological alterations of gastrointestinal tract probably play a major role. Failure to restore Th17 cells in gut-associated lymphoid tissues (GALT) might impair the recovery of the gut mucosal barrier. This review discusses recent advances on understanding the contribution of CD4+ T cell depletion to HIV pathogenesis. PMID:21994747

  13. DC/CIKs细胞通过无 miRNA 的 exosome 蛋白刺激后能增强对胰腺癌细胞的免疫作用%Increasing the immune activity of exosomes:the effect of miRNA-depleted exosome proteins on activating dendritic cell/cytokine-induced killer cells against pancreatic cancer

    Institute of Scientific and Technical Information of China (English)

    Ri-sheng QUE; Cheng LIN; Guo-ping DING; Zheng-rong WU; Li-ping CAO

    2016-01-01

    Background: Tumor-derived exosomes were considered to be potential candidates for tumor vaccines because they are abundant in immune-regulating proteins, whereas tumor exosomal miRNAs may induce immune tolerance, thereby having an opposite immune function. Objective: This study was designed to separate exosomal protein and depleted exosomal microRNAs (miRNAs), increasing the immune activity of exosomes for activating dendritic cell/cytokine-induced kil er cel s (DC/CIKs) against pancreatic cancer (PC). Methods:PC-derived exosomes (PEs) were extracted from cultured PANC-1 cel supernatants and then ruptured; this was fol owed by ultrafiltered exosome lysates (UELs). DCs were stimulated with lipopolysaccharide (LPS), PE, and UEL, fol owed by co-culture with CIKs. The anti-tumor effects of DC/CIKs against PC were evaluated by proliferation and kil ing rates, tumor ne-crosis factor-α(TNF-α) and perforin secretion. Exosomal miRNAs were depleted after lysis and ultrafiltration, while 128 proteins were retained, including several immune-activating proteins. Results: UEL-stimulated DC/CIKs showed a higher killing rate than LPS- and PE-stimulated DC/CIKs. Conclusions: miRNA-depleted exosome proteins may be promising agonists for specifical y activating DC/CIKs against PC.%目的:本文通过分离提取无小 RNA(miRNA)的外来体(exosome)刺激树突细胞/细胞因子活化杀伤细胞(DC/CIKs),激活其对于胰腺癌细胞的免疫杀伤作用。  创新点:无 miRNA的 exosome超速离心裂解产物可以通过激活 DC/CIKs 细胞增强其对肿瘤细胞的杀伤作用。  方法:通过收集PANC-1细胞的上清并超速离心提取其中的exosome。提取的DC细胞分别通过脂多糖、肿瘤来源exosome及无miRNA的exosome刺激后,与CIK细胞共培养。通过计算增值与杀伤效率,肿瘤坏死因子-α(TNF-α)及穿孔素的分泌,比较各组间CIK细胞对胰腺癌细胞的杀伤作用。  结论:经

  14. Tumor eradication after cyclophosphamide depends on concurrent depletion of regulatory T cells: a role for cycling TNFR2-expressing effector-suppressor T cells in limiting effective chemotherapy.

    Science.gov (United States)

    van der Most, Robbert G; Currie, Andrew J; Mahendran, Sathish; Prosser, Amy; Darabi, Anna; Robinson, Bruce W S; Nowak, Anna K; Lake, Richard A

    2009-08-01

    Tumor cell death potentially engages with the immune system. However, the efficacy of anti-tumor chemotherapy may be limited by tumor-driven immunosuppression, e.g., through CD25+ regulatory T cells. We addressed this question in a mouse model of mesothelioma by depleting or reconstituting CD25+ regulatory T cells in combination with two different chemotherapeutic drugs. We found that the efficacy of cyclophosphamide to eradicate established tumors, which has been linked to regulatory T cell depletion, was negated by adoptive transfer of CD25+ regulatory T cells. Analysis of post-chemotherapy regulatory T cell populations revealed that cyclophosphamide depleted cycling (Ki-67(hi)) T cells, including foxp3+ regulatory CD4+ T cells. Ki-67(hi) CD4+ T cells expressed increased levels of two markers, TNFR2 and ICOS, that have been associated with a maximally suppressive phenotype according to recently published studies. This suggest that cyclophosphamide depletes a population of maximally suppressive regulatory T cells, which may explain its superior anti-tumor efficacy in our model. Our data suggest that regulatory T cell depletion could be used to improve the efficacy of anti-cancer chemotherapy regimens. Indeed, we observed that the drug gemcitabine, which does not deplete cycling regulatory T cells, eradicates established tumors in mice only when CD25+ CD4+ T cells are concurrently depleted. Cyclophosphamide could be used to achieve regulatory T cell depletion in combination with chemotherapy.

  15. EZH2 depletion blocks the proliferation of colon cancer cells.

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    Bettina Fussbroich

    Full Text Available The Enhancer of Zeste 2 (EZH2 protein has been reported to stimulate cell growth in some cancers and is therefore considered to represent an interesting new target for therapeutic intervention. Here, we investigated a possible role of EZH2 for the growth control of colon cancer cells. RNA interference (RNAi-mediated intracellular EZH2 depletion led to cell cycle arrest of colon carcinoma cells at the G1/S transition. This was associated with a reduction of cell numbers upon transient transfection of synthetic EZH2-targeting siRNAs and with inhibition of their colony formation capacity upon stable expression of vector-borne siRNAs. We furthermore tested whether EZH2 may repress the growth-inhibitory p27 gene, as reported for pancreatic cancer. However, expression analyses of colon cancer cell lines and colon cancer biopsies did not reveal a consistent correlation between EZH2 and p27 levels. Moreover, EZH2 depletion did not re-induce p27 expression in colon cancer cells, indicating that p27 repression by EZH2 may be cell- or tissue-specific. Whole genome transcriptome analyses identified cellular genes affected by EZH2 depletion in colon cancer cell lines. They included several cancer-associated genes linked to cellular proliferation or invasion, such as Dag1, MageD1, SDC1, Timp2, and Tob1. In conclusion, our results demonstrate that EZH2 depletion blocks the growth of colon cancer cells. These findings might provide benefits for the treatment of colon cancer.

  16. Anti-CD20 B-cell depletion enhances monocyte reactivity in neuroimmunological disorders

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    Hohlfeld Reinhard

    2011-10-01

    Full Text Available Abstract Background Clinical trials evaluating anti-CD20-mediated B-cell depletion in multiple sclerosis (MS and neuromyelitis optica (NMO generated encouraging results. Our recent studies in the MS model experimental autoimmune encephalomyelitis (EAE attributed clinical benefit to extinction of activated B-cells, but cautioned that depletion of naïve B-cells may be undesirable. We elucidated the regulatory role of un-activated B-cells in EAE and investigated whether anti-CD20 may collaterally diminish regulatory B-cell properties in treatment of neuroimmunological disorders. Methods Myelin oligodendrocyte glycoprotein (MOG peptide-immunized C57Bl/6 mice were depleted of B-cells. Functional consequences for regulatory T-cells (Treg and cytokine production of CD11b+ antigen presenting cells (APC were assessed. Peripheral blood mononuclear cells from 22 patients receiving anti-CD20 and 23 untreated neuroimmunological patients were evaluated for frequencies of B-cells, T-cells and monocytes; monocytic reactivity was determined by TNF-production and expression of signalling lymphocytic activation molecule (SLAM. Results We observed that EAE-exacerbation upon depletion of un-activated B-cells closely correlated with an enhanced production of pro-inflammatory TNF by CD11b+ APC. Paralleling this pre-clinical finding, anti-CD20 treatment of human neuroimmunological disorders increased the relative frequency of monocytes and accentuated pro-inflammatory monocyte function; when reactivated ex vivo, a higher frequency of monocytes from B-cell depleted patients produced TNF and expressed the activation marker SLAM. Conclusions These data suggest that in neuroimmunological disorders, pro-inflammatory APC activity is controlled by a subset of B-cells which is eliminated concomitantly upon anti-CD20 treatment. While this observation does not conflict with the general concept of B-cell depletion in human autoimmunity, it implies that its safety and

  17. Selective depletion of non-specific T cells as an early event in T cell response to bacterial and viral infections

    Institute of Scientific and Technical Information of China (English)

    JIANG Jiu

    2005-01-01

    @@ Early T cell depletion occurs prior to the development of an effective immune response to infections.Both antigen-specific and non-specific T cells are induced to express early activation markers soon after microbial infections.This is followed by massive depletion of non-specific T cells and extensive proliferation of antigen-specific T cells.Proliferating antigen-specific cells exhibit a broad spectrum of late activation markers while non-specific cells exhibit no sign of further activation before succumbing to apoptosis.These results have crucial implications for the understanding of early events in the development of a robust T cell response.

  18. Roles of regulatory T cells in cancer immunity.

    Science.gov (United States)

    Takeuchi, Yoshiko; Nishikawa, Hiroyoshi

    2016-08-01

    CD4(+) regulatory T cells (Tregs) expressing the transcription factor FoxP3 are highly immune suppressive and play central roles in the maintenance of self-tolerance and immune homeostasis, yet in malignant tumors they promote tumor progression by suppressing effective antitumor immunity. Indeed, higher infiltration by Tregs is observed in tumor tissues, and their depletion augments antitumor immune responses in animal models. Additionally, increased numbers of Tregs and, in particular, decreased ratios of CD8(+) T cells to Tregs among tumor-infiltrating lymphocytes are correlated with poor prognosis in various types of human cancers. The recent success of cancer immunotherapy represented by immune checkpoint blockade has provided a new insight in cancer treatment, yet more than half of the treated patients did not experience clinical benefits. Identifying biomarkers that predict clinical responses and developing novel immunotherapies are therefore urgently required. Cancer patients whose tumors contain a large number of neoantigens stemming from gene mutations, which have not been previously recognized by the immune system, provoke strong antitumor T-cell responses associated with clinical responses following immune checkpoint blockade, depending on the resistance to Treg-mediated suppression. Thus, integration of a strategy restricting Treg-mediated immune suppression may expand the therapeutic spectrum of cancer immunotherapy towards patients with a lower number of neoantigens. In this review, we address the current understanding of Treg-mediated immune suppressive mechanisms in cancer, the involvement of Tregs in cancer immunotherapy, and strategies for effective and tolerable Treg-targeted therapy. PMID:27160722

  19. Experimental depletion of different renal interstitial cell populations

    International Nuclear Information System (INIS)

    To define different populations of renal interstitial cells and investigate some aspects of their function, we studied the kidneys of normal rats and rats with hereditary diabetes insipidus (DI, Brattleboro) after experimental manipulations expected to alter the number of interstitial cells. DI rats showed an almost complete loss of interstitial cells in their renal papillae after treatment with a high dose of vasopressin. In spite of the lack of interstitial cells, the animals concentrated their urine to the same extent as vasopressin-treated normal rats, indicating that the renomedullary interstitial cells do not have an important function in concentrating the urine. The interstitial cells returned nearly to normal within 1 week off vasopressin treatment, suggesting a rapid turnover rate of these cells. To further distinguish different populations of interstitial cells, we studied the distribution of class II MHC antigen expression in the kidneys of normal and bone-marrow depleted Wistar rats. Normal rats had abundant class II antigen-positive interstitial cells in the renal cortex and outer medulla, but not in the inner medulla (papilla). Six days after 1000 rad whole body irradiation, the stainable cells were almost completely lost, but electron microscopic morphometry showed a virtually unchanged volume density of interstitial cells in the cortex and outer medulla, as well as the inner medulla. Thus, irradiation abolished the expression of the class II antigen but caused no significant depletion of interstitial cells

  20. Dystroglycan depletion inhibits the functions of differentiated HL-60 cells.

    Science.gov (United States)

    Martínez-Zárate, Alma Delia; Martínez-Vieyra, Ivette; Alonso-Rangel, Lea; Cisneros, Bulmaro; Winder, Steve J; Cerecedo, Doris

    2014-06-01

    Dystroglycan has recently been characterized in blood tissue cells, as part of the dystrophin glycoprotein complex but to date nothing is known of its role in the differentiation process of neutrophils. We have investigated the role of dystroglycan in the human promyelocytic leukemic cell line HL-60 differentiated to neutrophils. Depletion of dystroglycan by RNAi resulted in altered morphology and reduced properties of differentiated HL-60 cells, including chemotaxis, respiratory burst, phagocytic activities and expression of markers of differentiation. These findings strongly implicate dystroglycan as a key membrane adhesion protein involved in the differentiation process in HL-60 cells.

  1. Cytotoxicity and glutathione depletion studies using CHOK cells

    International Nuclear Information System (INIS)

    Radiosensitization characteristics of newly synthesized isoindole-4, 7-diones have been established in the authors' laboratories. Cytotoxicity studies of isoindole-4, 7-diones on chinese hamster ovary cell (CHOK) have been carried out. The effects that different concentrations of isoindole-4, 7-diones have on cell growth as a function of time after treatment on both systems (oxic and hypoxic) have been determined. Most of isoindole-4, 7-diones used in these studies show more cytotoxic effect under hypoxic conditions. Gluthathione depletion was also measured in both systems. Most of the quinones studied deplete the concentration of glutathione in the CHOK cells. The results will be compared with similar studies carried out with the well known radiosensitizers misonidazole. It is hoped that the isoindole-r, 7-diones are a new family of chemical radiosensitizers

  2. Immune Cells in Blood Recognize Tumors

    Science.gov (United States)

    NCI scientists have developed a novel strategy for identifying immune cells circulating in the blood that recognize specific proteins on tumor cells, a finding they believe may have potential implications for immune-based therapies.

  3. M cell-depletion blocks oral prion disease pathogenesis.

    Science.gov (United States)

    Donaldson, D S; Kobayashi, A; Ohno, H; Yagita, H; Williams, I R; Mabbott, N A

    2012-03-01

    Many prion diseases are orally acquired. Our data show that after oral exposure, early prion replication upon follicular dendritic cells (FDC) in Peyer's patches is obligatory for the efficient spread of disease to the brain (termed neuroinvasion). For prions to replicate on FDC within Peyer's patches after ingestion of a contaminated meal, they must first cross the gut epithelium. However, the mechanism through which prions are conveyed into Peyer's patches is uncertain. Within the follicle-associated epithelium overlying Peyer's patches are microfold cells (M cells), unique epithelial cells specialized for the transcytosis of particles. We show that following M cell-depletion, early prion accumulation upon FDC in Peyer's patches is blocked. Furthermore, in the absence of M cells at the time of oral exposure, neuroinvasion and disease development are likewise blocked. These data suggest M cells are important sites of prion uptake from the gut lumen into Peyer's patches. PMID:22294048

  4. Persistent Simian Immunodeficiency Virus Infection Causes Ultimate Depletion of Follicular Th Cells in AIDS.

    Science.gov (United States)

    Xu, Huanbin; Wang, Xiaolei; Malam, Naomi; Lackner, Andrew A; Veazey, Ronald S

    2015-11-01

    CD4(+) T follicular helper (Tfh) cells are critical for the generation of humoral immune responses to pathogenic infections, providing help for B cell development, survival, and affinity maturation of Abs. Although CD4(+) Tfh cells are reported to accumulate in HIV or SIV infection, we found that germinal center Tfh cells, defined in this study as CXCR5(+)PD-1(HIGH)CD4(+) T cells, did not consistently accumulate in chronically SIV-infected rhesus macaques compared with those infected with less pathogenic simian HIV, vaccinated and SIVmac-challenged, or SIVmac-infected Mamu-A*01(+) macaques, all of which are associated with some control of virus replication and slower disease progression. Interestingly, CXCR5(+)PD-1(HIGH) Tfh cells in lymphoid tissues were eventually depleted in macaques with AIDS compared with the other cohorts. Chronic activation and proliferation of CXCR5(+)PD-1(HIGH) Tfh were increased, but PD-L2 expression was downregulated on B cells, possibly resulting in germinal center Tfh cell apoptosis. Together, these findings suggest that changes in CXCR5(+)PD-1(HIGH) Tfh cells in lymph nodes correlate with immune control during infection, and their loss or dysregulation contribute to impairment of B cell responses and progression to AIDS.

  5. A comparative review of methods for T cell depletion in the prophylaxis of graft-versus-host disease.

    Science.gov (United States)

    Hertenstein, B; Arseniev, L; Novotny, J; Ganser, A

    1998-02-01

    Graft-versus-host disease (GVHD) remains the major problem to be overcome in transplantation of allogeneic haemopoietic stem cells. Using immunosuppressive prophylaxis with cyclosporin and methotrexate, moderate to severe acute GVHD develops in approximately 45% of transplant recipients with an HLA-identical sibling donor and in >75% of patients from unrelated HLA-identical or partially matched related donors. The pathophysiology of GVHD is complex and still incompletely described. Experimental and clinical data indicate that GVHD is largely mediated by immunocompetent T cells in the donor stem cell graft which are reactive against recipient (host) tissues. Depletion of these immunocompetent T cells from the stem cell graft offers a way to effectively prevent GVHD. The first section of this review describes the technical principles of different methods of T cell depletion. The advantages, limitations and level of T cell depletion achievable by physical methods or by positive and negative immunoselection procedures using monoclonal antibodies are comprehensively discussed. A short section concentrates on technical problems in the enumeration of T cells in the context of depletion efficiency. In the section on clinical studies, the focus is on the efficacy of different T cell depletion methods in avoiding GVHD in different clinical settings. The various methods are compared in transplantation from HLA-identical and nonidentical siblings or matched unrelated donors. The major drawbacks of T cell depletion are discussed in detail. Failure of engraftment and graft rejection is a more frequent problem following T cell-depleted transplants, particularly with HLA nonidentical donor-recipient pairs. An increase in leukaemic relapse rate is seen in certain haematological malignancies, especially in chronic myeloid leukaemia. Delayed recovery of anti-infectious immunity occurs, leading to an increased incidence of cytomegalovirus and Epstein-Barr virus related problems. The

  6. Cellular aging of mitochondrial DNA-depleted cells

    International Nuclear Information System (INIS)

    We have reported that mitochondrial DNA-depleted ρ0 cells are resistant to cell death. Because aged cells have frequent mitochondrial DNA mutations, the resistance of ρ0 cells against cell death might be related to the apoptosis resistance of aged cells and frequent development of cancers in aged individuals. We studied if ρ0 cells have features simulating aged cells. SK-Hep1 hepatoma ρ0 cells showed typical morphology associated with aging such as increased size and elongated appearance. They had increased senescence-associated β-Gal activity, lipofuscin pigment, and plasminogen activator inhibitor-1 expression. Consistent with their decreased proliferation, the expression of mitotic cyclins was decreased and that of cdk inhibitors was increased. Rb hypophosphorylation and decreased telomerase activity were also noted. Features simulating aged cells were also observed in MDA-MB-435 ρ0 cells. These results support the mitochondrial theory of aging, and suggest that ρ0 cells could serve as an in vitro model for aged cells

  7. Quantification of depletion-induced adhesion of Red Blood Cells

    CERN Document Server

    Steffen, Patrick; Wagner, Christian

    2012-01-01

    Red blood cells (RBC) are known to form aggregates in the forms of rouleaux due to the presence of plasma proteins under physiological conditions. Rouleaux formation can be also induced in vitro by the addition of macromolecules to the RBC solution. Current data on the adhesion strength between red blood cells in their natural discocyte shapes mostly rely on indirect measurements like flow chamber experiments, but on the single cell level data is lacking. Here we present measurements on the dextran induced aggregation of red blood cells by use of atomic force microscopy based single cell force spectroscopy (SCFS). The effects of dextran concentration and molecular weight on the interaction energy of adhering RBCs was determined. The results are in good agreement with a model based on the depletion effect and former experimental studies.

  8. SUZ12 Depletion Suppresses the Proliferation of Gastric Cancer Cells

    Directory of Open Access Journals (Sweden)

    Yingjun Cui

    2013-05-01

    Full Text Available Background/Aims: SUZ12 and EZH2 are two main components of polycomb repressive complex 2 (PRC2 that is known to be of great importance in tumorigenesis. EZH2 has been reported to play a vital role in pathogenesis of human cancer. However, whether SUZ12 has equivalent roles in tumorigenesis has not been demonstrated. Here, we investigated a possible role of SUZ12 for the proliferation of gastric cancer cells. Methods: Western-blot analysis was used to detected the levels of SUZ12, H3K27me3, EZH2 and p27 in ten gastric cell lines. SUZ12 was depleted by RNA interference. Cell cycle was detected by flow cytometry. Luciferase assays was to analyze whether miR-200b directly regulate SUZ12. Results: We found that SUZ12 depletion mediated by RNA interference (RNAi led to a reduction of gastric cell numbers and arrested the cell cycle at G1/S point. As an important G1/S phase inhibitory gene, p27 is re-induced to some extent by SUZ12 knockdown. Furthermore, we demonstrated that SUZ12 was directly downregulated by miR-200b. Conclusion: We provide evidence suggesting that SUZ12 may be a potential therapeutic target for gastric cancer.

  9. Tumor vaccine strategies after allogeneic T-cell depleted bone marrow transplantation

    Directory of Open Access Journals (Sweden)

    Ferrara James L.M.

    2002-01-01

    Full Text Available Allogeneic bone marrow transplantation is currently restricted to hematological malignancies because of a lack of anti-tumor activity against solid cancers. We have tested a novel treatment strategy to stimulate specific anti-tumor activity against a solid tumor after transplantation by vaccination with irradiated tumor cells engineered to secrete granulocyte-macrophage colony-stimulating factor. Using the B16 melanoma model, we found that vaccination elicited potent anti-tumor activity in recipients of syngeneic bone marrow transplantation in a time dependent fashion, and that immune reconstitution was critical for the development of anti-tumor activity. Vaccination did not stimulate anti-tumor immunity after allogeneic bone marrow transplantation because of the post-transplantation immunodeficiency associated with graft-versus-host disease. Remarkably, vaccination was effective in stimulating potent and long-lasting anti-tumor activity in recipients of T cell-depleted allogeneic bone marrow. Thus T cells derived from donor stem cells were able to recognize tumor antigens even though they remained tolerant to host histocompatibility antigens. Donor leukocyte infusion from a donor immunized with the recipient-derived B16 vaccines enhanced clinical activity of tumor vaccines without exacerbating graft-versus-host disease and CD4+ T cells are essential for this enhancement. These results demonstrate that vaccination of both donors and recipients can stimulate potent anti-tumor effects without the induction of graft-versus-host disease, and this strategy has important implications for the treatment of patients with solid malignancies.

  10. Immune cells in the female reproductive tract.

    Science.gov (United States)

    Lee, Sung Ki; Kim, Chul Jung; Kim, Dong-Jae; Kang, Jee-Hyun

    2015-02-01

    The female reproductive tract has two main functions: protection against microbial challenge and maintenance of pregnancy to term. The upper reproductive tract comprises the fallopian tubes and the uterus, including the endocervix, and the lower tract consists of the ectocervix and the vagina. Immune cells residing in the reproductive tract play contradictory roles: they maintain immunity against vaginal pathogens in the lower tract and establish immune tolerance for sperm and an embryo/fetus in the upper tract. The immune system is significantly influenced by sex steroid hormones, although leukocytes in the reproductive tract lack receptors for estrogen and progesterone. The leukocytes in the reproductive tract are distributed in either an aggregated or a dispersed form in the epithelial layer, lamina propria, and stroma. Even though immune cells are differentially distributed in each organ of the reproductive tract, the predominant immune cells are T cells, macrophages/dendritic cells, natural killer (NK) cells, neutrophils, and mast cells. B cells are rare in the female reproductive tract. NK cells in the endometrium significantly expand in the late secretory phase and further increase their number during early pregnancy. It is evident that NK cells and regulatory T (Treg) cells are extremely important in decidual angiogenesis, trophoblast migration, and immune tolerance during pregnancy. Dysregulation of endometrial/decidual immune cells is strongly related to infertility, miscarriage, and other obstetric complications. Understanding the immune system of the female reproductive tract will significantly contribute to women's health and to success in pregnancy. PMID:25713505

  11. ``Backpack'' Functionalized Living Immune Cells

    Science.gov (United States)

    Swiston, Albert; Um, Soong Ho; Irvine, Darrell; Cohen, Robert; Rubner, Michael

    2009-03-01

    We demonstrate that functional polymeric ``backpacks'' built from polyelectrolyte multilayers (PEMs) can be attached to a fraction of the surface area of living, individual lymphocytes. Backpacks containing fluorescent polymers, superparamagnetic nanoparticles, and commercially available quantum dots have been attached to B and T-cells, which may be spatially manipulated using a magnetic field. Since the backpack does not occlude the entire cellular surface from the environment, this technique allows functional synthetic payloads to be attached to a cell that is free to perform its native functions, thereby synergistically utilizing both biological and synthetic functionalities. For instance, we have shown that backpack-modified T-cells are able to migrate on surfaces for several hours following backpack attachment. Possible payloads within the PEM backpack include drugs, vaccine antigens, thermally responsive polymers, nanoparticles, and imaging agents. We will discuss how this approach has broad potential for applications in bioimaging, single-cell functionalization, immune system and tissue engineering, and cell-based therapeutics where cell-environment interactions are critical.

  12. Cytotoxicity of tumor antigen specific human T cells is unimpaired by arginine depletion.

    Directory of Open Access Journals (Sweden)

    Markus Munder

    Full Text Available Tumor-growth is often associated with the expansion of myeloid derived suppressor cells that lead to local or systemic arginine depletion via the enzyme arginase. It is generally assumed that this arginine deficiency induces a global shut-down of T cell activation with ensuing tumor immune escape. While the impact of arginine depletion on polyclonal T cell proliferation and cytokine secretion is well documented, its influence on chemotaxis, cytotoxicity and antigen specific activation of human T cells has not been demonstrated so far. We show here that chemotaxis and early calcium signaling of human T cells are unimpaired in the absence of arginine. We then analyzed CD8(+ T cell activation in a tumor peptide as well as a viral peptide antigen specific system: (i CD8(+ T cells with specificity against the MART-1aa26-35*A27L tumor antigen expanded with in vitro generated dendritic cells, and (ii clonal CMV pp65aa495-503 specific T cells and T cells retrovirally transduced with a CMV pp65aa495-503 specific T cell receptor were analyzed. Our data demonstrate that human CD8(+ T cell antigen specific cytotoxicity and perforin secretion are completely preserved in the absence of arginine, while antigen specific proliferation as well as IFN-γ and granzyme B secretion are severely compromised. These novel results highlight the complexity of antigen specific T cell activation and demonstrate that human T cells can preserve important activation-induced effector functions in the context of arginine deficiency.

  13. Alemtuzumab treatment alters circulating innate immune cells in multiple sclerosis

    Science.gov (United States)

    Ahmetspahic, Diana; Ruck, Tobias; Schulte-Mecklenbeck, Andreas; Schwarte, Kathrin; Jörgens, Silke; Scheu, Stefanie; Windhagen, Susanne; Graefe, Bettina; Melzer, Nico; Klotz, Luisa; Arolt, Volker; Wiendl, Heinz; Meuth, Sven G.

    2016-01-01

    Objective: To characterize changes in myeloid and lymphoid innate immune cells in patients with relapsing-remitting multiple sclerosis (MS) during a 6-month follow-up after alemtuzumab treatment. Methods: Circulating innate immune cells including myeloid cells and innate lymphoid cells (ILCs) were analyzed before and 6 and 12 months after onset of alemtuzumab treatment. Furthermore, a potential effect on granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)–23 production by myeloid cells and natural killer (NK) cell cytolytic activity was determined. Results: In comparison to CD4+ T lymphocytes, myeloid and lymphoid innate cell subsets of patients with MS expressed significantly lower amounts of CD52 on their cell surface. Six months after CD52 depletion, numbers of circulating plasmacytoid dendritic cells (DCs) and conventional DCs were reduced compared to baseline. GM-CSF and IL-23 production in DCs remained unchanged. Within the ILC compartment, the subset of CD56bright NK cells specifically expanded under alemtuzumab treatment, but their cytolytic activity did not change. Conclusions: Our findings demonstrate that 6 months after alemtuzumab treatment, specific DC subsets are reduced, while CD56bright NK cells expanded in patients with MS. Thus, alemtuzumab specifically restricts the DC compartment and expands the CD56bright NK cell subset with potential immunoregulatory properties in MS. We suggest that remodeling of the innate immune compartment may promote long-term efficacy of alemtuzumab and preserve immunocompetence in patients with MS. PMID:27766281

  14. Depleted-Heterojunction Colloidal Quantum Dot Solar Cells

    KAUST Repository

    Pattantyus-Abraham, Andras G.

    2010-06-22

    Colloidal quantum dot (CQD) photovoltaics combine low-cost solution processability with quantum size-effect tunability to match absorption with the solar spectrum. Rapid recent advances in CQD photovoltaics have led to impressive 3.6% AM1.5 solar power conversion efficiencies. Two distinct device architectures and operating mechanisms have been advanced. The first-the Schottky device-was optimized and explained in terms of a depletion region driving electron-hole pair separation on the semiconductor side of a junction between an opaque low-work-function metal and a p-type CQD film. The second-the excitonic device-employed a CQD layer atop a transparent conductive oxide (TCO) and was explained in terms of diffusive exciton transport via energy transfer followed by exciton separation at the type-II heterointerface between the CQD film and the TCO. Here we fabricate CQD photovoltaic devices on TCOs and show that our devices rely on the establishment of a depletion region for field-driven charge transport and separation, and that they also exploit the large bandgap of the TCO to improve rectification and block undesired hole extraction. The resultant depletedheterojunction solar cells provide a 5.1% AM1.5 power conversion efficiency. The devices employ infrared-bandgap size-effect-tuned PbS CQDs, enabling broadband harvesting of the solar spectrum. We report the highest opencircuit voltages observed in solid-state CQD solar cells to date, as well as fill factors approaching 60%, through the combination of efficient hole blocking (heterojunction) and very small minority carrier density (depletion) in the large-bandgap moiety. © 2010 American Chemical Society.

  15. 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, ...

  16. Experimental depletion of CD8+ cells in acutely SIVagm-Infected African Green Monkeys results in increased viral replication

    Directory of Open Access Journals (Sweden)

    Apetrei Cristian

    2010-05-01

    Full Text Available Abstract Background In vivo CD8+ cell depletions in pathogenic SIV infections identified a key role for cellular immunity in controlling viral load (VL and disease progression. However, similar studies gave discordant results in chronically-infected SMs, leading some authors to propose that in natural hosts, SIV replication is independent of cellular immunity. To assess the role of cellular immune responses in the control of SIV replication in natural hosts, we investigated the impact of CD8+ cell depletion during acute SIV infection in AGMs. Results Nine AGMs were infected with SIVagm.sab and were followed up to day 225 p.i. Four were intravenously infused with the cM-T807 antibody on days 0 (50 mg/kg, 6, and 13 (10 mg/kg, respectively post infection (p.i.. CD8+ cells were depleted for up to 28 days p.i. in peripheral blood and LNs in all treated AGMs. Partial CD8+ T cell depletion occurred in the intestine. SIVagm VLs peaked at similar levels in both groups (107-108 RNA copies/ml. However, while VLs were controlled in undepleted AGMs, reaching set-point levels (104-105 RNA copies/ml by day 28 p.i., high VLs (>106 RNA copies/ml were maintained by day 21 p.i. in CD8-depleted AGMs. By day 42 p.i., VLs were comparable between the two groups. The levels of immune activation and proliferation remained elevated up to day 72 p.i. in CD8-depleted AGMs and returned to preinfection levels in controls by day 28 p.i. None of the CD8-depleted animals progressed to AIDS. Conclusion CD8+ cells are responsible for a partial control of postacute viral replication in SIVagm.sab-infected AGMs. In contrast to macaques, the SIVagm-infected AGMs are able to control viral replication after recovery of the CD8+ T cells and avoid disease progression.

  17. Sequential Dysfunction and Progressive Depletion of Candida albicans-Specific CD4 T Cell Response in HIV-1 Infection.

    Directory of Open Access Journals (Sweden)

    Fengliang Liu

    2016-06-01

    Full Text Available Loss of immune control over opportunistic infections can occur at different stages of HIV-1 (HIV disease, among which mucosal candidiasis caused by the fungal pathogen Candida albicans (C. albicans is one of the early and common manifestations in HIV-infected human subjects. The underlying immunological basis is not well defined. We have previously shown that compared to cytomegalovirus (CMV-specific CD4 cells, C. albicans-specific CD4 T cells are highly permissive to HIV in vitro. Here, based on an antiretroviral treatment (ART naïve HIV infection cohort (RV21, we investigated longitudinally the impact of HIV on C. albicans- and CMV-specific CD4 T-cell immunity in vivo. We found a sequential dysfunction and preferential depletion for C. albicans-specific CD4 T cell response during progressive HIV infection. Compared to Th1 (IFN-γ, MIP-1β functional subsets, the Th17 functional subsets (IL-17, IL-22 of C. albicans-specific CD4 T cells were more permissive to HIV in vitro and impaired earlier in HIV-infected subjects. Infection history analysis showed that C. albicans-specific CD4 T cells were more susceptible to HIV in vivo, harboring modestly but significantly higher levels of HIV DNA, than CMV-specific CD4 T cells. Longitudinal analysis of HIV-infected individuals with ongoing CD4 depletion demonstrated that C. albicans-specific CD4 T-cell response was preferentially and progressively depleted. Taken together, these data suggest a potential mechanism for earlier loss of immune control over mucosal candidiasis in HIV-infected patients and provide new insights into pathogen-specific immune failure in AIDS pathogenesis.

  18. Conversion of Fibroblasts to Neural Cells by p53 Depletion

    Directory of Open Access Journals (Sweden)

    Di Zhou

    2014-12-01

    Full Text Available Conversion from fibroblasts to neurons has recently been successfully induced. However, the underlying mechanisms are poorly understood. Here, we find that depletion of p53 alone converts fibroblasts into all three major neural lineages. The induced neuronal cells express multiple neuron-specific proteins and generate action potentials and transmitter-receptor-mediated currents. Surprisingly, depletion does not affect the well-known tumorigenic p53 target, p21. Instead, knockdown of p53 upregulates neurogenic transcription factors, which in turn boosts fibroblast-neuron conversion. p53 binds the promoter of the neurogenic transcription factor Neurod2 and regulates its expression during fibroblast-neuron conversion. Furthermore, our method provides a high efficiency of conversion in late-passage fibroblasts. Genome-wide transcriptional analysis shows that the p53-deficiency-induced neurons exhibit an expression profile different from parental fibroblasts and similar to control-induced neurons. The results may help to understand and improve neural conversion mechanisms to develop robust neuron-replacement therapy strategies.

  19. Immune cell interplay in colorectal cancer prognosis

    Institute of Scientific and Technical Information of China (English)

    Samuel; E; Norton; Kirsten; A; Ward-Hartstonge; Edward; S; Taylor; Roslyn; A; Kemp

    2015-01-01

    The immune response to colorectal cancer has proven to be a reliable measure of patient outcome in several studies. However, the complexity of the immune response in this disease is not well understood, par-ticularly the interactions between tumour-associated cells and cells of the innate and adaptive immune system. This review will discuss the relationship betweencancer associated fibroblasts and macrophages, as well as between macrophages and T cells, and demonstrate how each population may support or prevent tumour growth in a different immune environment.

  20. Depletion of Neutrophils Exacerbates the Early Inflammatory Immune Response in Lungs of Mice Infected with Paracoccidioides brasiliensis.

    Science.gov (United States)

    Pino-Tamayo, Paula Andrea; Puerta-Arias, Juan David; Lopera, Damaris; Urán-Jiménez, Martha Eugenia; González, Ángel

    2016-01-01

    Neutrophils predominate during the acute phase of the Paracoccidioides brasiliensis infection. Herein, we determined the role of the neutrophil during the early stages of experimental pulmonary paracoccidioidomycosis using a monoclonal antibody (mAb) specific for neutrophils. Male BALB/c mice were inoculated intranasally with 1.5 × 10(6) or 2 × 10(6) P. brasiliensis yeast cells. The mAb was administered 24 h before infection, followed by doses every 48 h until mice were sacrificed. Survival time was evaluated and mice were sacrificed at 48 h and 96 h after inoculation to assess cellularity, fungal load, cytokine/chemokine levels, and histopathological analysis. Neutrophils from mAb-treated mice were efficiently depleted (99.04%). Eighty percent of the mice treated with the mAb and infected with 1.5 × 10(6) yeast cells died during the first two weeks after infection. When mice were treated and infected with 2 × 10(6) yeast cells, 100% of them succumbed by the first week after infection. During the acute inflammatory response significant increases in numbers of eosinophils, fungal load and levels of proinflammatory cytokines/chemokines were observed in the mAb-treated mice. We also confirmed that neutrophils are an important source of IFN-γ and IL-17. These results indicate that neutrophils are essential for protection as well as being important for regulating the early inflammatory immune response in experimental pulmonary paracoccidioidomycosis. PMID:27642235

  1. Janus kinases in immune cell signaling

    OpenAIRE

    Ghoreschi, Kamran; Laurence, Arian; O’Shea, John J.

    2009-01-01

    The Janus family kinases (Jaks), Jak1, Jak2, Jak3, and Tyk2, form one subgroup of the non-receptor protein tyrosine kinases. They are involved in cell growth, survival, development, and differentiation of a variety of cells but are critically important for immune cells and hematopoietic cells. Data from experimental mice and clinical observations have unraveled multiple signaling events mediated by Jak in innate and adaptive immunity. Deficiency of Jak3 or Tyk2 results in defined clinical dis...

  2. Major depletion of plasmacytoid dendritic cells in HIV-2 infection, an attenuated form of HIV disease.

    Directory of Open Access Journals (Sweden)

    Rita Cavaleiro

    2009-11-01

    Full Text Available Plasmacytoid dendritic cells (pDC provide an important link between innate and acquired immunity, mediating their action mainly through IFN-alpha production. pDC suppress HIV-1 replication, but there is increasing evidence suggesting they may also contribute to the increased levels of cell apoptosis and pan-immune activation associated with disease progression. Although having the same clinical spectrum, HIV-2 infection is characterized by a strikingly lower viremia and a much slower rate of CD4 decline and AIDS progression than HIV-1, irrespective of disease stage. We report here a similar marked reduction in circulating pDC levels in untreated HIV-1 and HIV-2 infections in association with CD4 depletion and T cell activation, in spite of the undetectable viremia found in the majority of HIV-2 patients. Moreover, the same overexpression of CD86 and PD-L1 on circulating pDC was found in both infections irrespective of disease stage or viremia status. Our observation that pDC depletion occurs in HIV-2 infected patients with undetectable viremia indicates that mechanisms other than direct viral infection determine the pDC depletion during persistent infections. However, viremia was associated with an impairment of IFN-alpha production on a per pDC basis upon TLR9 stimulation. These data support the possibility that diminished function in vitro may relate to prior activation by HIV virions in vivo, in agreement with our finding of higher expression levels of the IFN-alpha inducible gene, MxA, in HIV-1 than in HIV-2 individuals. Importantly, serum IFN-alpha levels were not elevated in HIV-2 infected individuals. In conclusion, our data in this unique natural model of "attenuated" HIV immunodeficiency contribute to the understanding of pDC biology in HIV/AIDS pathogenesis, showing that in the absence of detectable viremia a major depletion of circulating pDC in association with a relatively preserved IFN-alpha production does occur.

  3. Myeloid Cells' Evasion of Melanoma Immunity

    Science.gov (United States)

    Wang, Jun; Chen, Lieping

    2015-01-01

    An immune-suppressive role of myeloid-derived suppressor cells (MDSCs) in melanoma has long been speculated, whereas molecular mechanisms underlying this role are not well understood. Here, Chung and colleagues show that dendritic cell-associated, heparan sulfate proteoglycans-dependent integrin ligand (DC-HIL), a cell surface immune-modulatory molecule, is highly expressed on tumor-associated MDSCs. Genetic ablation or antibody blockade of DC-HIL delays the growth of transplantable B16 melanoma in syngeneic mice, which is accompanied by enhanced antitumor T-cell activities. These findings support a role for DC-HIL in immune evasion within the melanoma microenvironment. PMID:25318429

  4. PCM1 Depletion Inhibits Glioblastoma Cell Ciliogenesis and Increases Cell Death and Sensitivity to Temozolomide

    Directory of Open Access Journals (Sweden)

    Lan B. Hoang-Minh

    2016-10-01

    Full Text Available A better understanding of the molecules implicated in the growth and survival of glioblastoma (GBM cells and their response to temozolomide (TMZ, the standard-of-care chemotherapeutic agent, is necessary for the development of new therapies that would improve the outcome of current GBM treatments. In this study, we characterize the role of pericentriolar material 1 (PCM1, a component of centriolar satellites surrounding centrosomes, in GBM cell proliferation and sensitivity to genotoxic agents such as TMZ. We show that PCM1 is expressed around centrioles and ciliary basal bodies in patient GBM biopsies and derived cell lines and that its localization is dynamic throughout the cell cycle. To test whether PCM1 mediates GBM cell proliferation and/or response to TMZ, we used CRISPR/Cas9 genome editing to generate primary GBM cell lines depleted of PCM1. These PCM1-depleted cells displayed reduced AZI1 satellite protein localization and significantly decreased proliferation, which was attributable to increased apoptotic cell death. Furthermore, PCM1-depleted lines were more sensitive to TMZ toxicity than control lines. The increase in TMZ sensitivity may be partly due to the reduced ability of PCM1-depleted cells to form primary cilia, as depletion of KIF3A also ablated GBM cells' ciliogenesis and increased their sensitivity to TMZ while preserving PCM1 localization. In addition, the co-depletion of KIF3A and PCM1 did not have any additive effect on TMZ sensitivity. Together, our data suggest that PCM1 plays multiple roles in GBM pathogenesis and that associated pathways could be targeted to augment current or future anti-GBM therapies.

  5. Cell-Mediated Immunity in Elite Controllers Naturally Controlling HIV Viral Load.

    Science.gov (United States)

    Genovese, Luca; Nebuloni, Manuela; Alfano, Massimo

    2013-01-01

    The natural course of human immunodeficiency virus (HIV) infection is characterized by high viral load, depletion of immune cells, and immunodeficiency, ultimately leading to acquired immunodeficiency syndrome phase and the occurrence of opportunistic infections and diseases. Since the discovery of HIV in the early 1980s a naturally selected population of infected individuals has been emerged in the last years, characterized by being infected for many years, with viremia constantly below detectable level and poor depletion of immune cells. These individuals are classified as "elite controllers (EC) or suppressors" and do not develop disease in the absence of anti-retroviral therapy. Unveiling host factors and immune responses responsible for the elite status will likely provide clues for the design of therapeutic vaccines and functional cures. Scope of this review was to examine and discuss differences of the cell-mediated immune responses between HIV+ individuals with disease progression and EC. PMID:23577012

  6. Cell-mediated Immunity in Elite Controllers Naturally Controlling HIV Viral Load

    Directory of Open Access Journals (Sweden)

    Luca eGenovese

    2013-04-01

    Full Text Available The natural course of HIV infection is characterized by high viral load, depletion of immune cells and immunodeficiency, ultimately leading to acquired immunodeficiency syndrome (AIDS phase and the occurrence of opportunistic infections and diseases.Since the discovery of HIV in the early 80’s a naturally selected population of infected individuals has been emerged in the last years, characterized by being infected for many years, with viremia constantly below detectable level and poor depletion of immune cells. These individuals are classified as elite controllers or suppressors and do not develop disease in the absence of anti-retroviral therapy.Unveiling host factors and immune responses responsible for the elite status will likely provide clues for the design of therapeutic vaccines and functional cures. Scope of this review was to examine and discuss differences of the cell-mediated immune responses between HIV+ individuals with disease progression and elite controllers.

  7. Immune Cells in the Female Reproductive Tract

    OpenAIRE

    Lee, Sung Ki; Kim, Chul Jung; Kim, Dong-Jae; Kang, Jee-Hyun

    2015-01-01

    The female reproductive tract has two main functions: protection against microbial challenge and maintenance of pregnancy to term. The upper reproductive tract comprises the fallopian tubes and the uterus, including the endocervix, and the lower tract consists of the ectocervix and the vagina. Immune cells residing in the reproductive tract play contradictory roles: they maintain immunity against vaginal pathogens in the lower tract and establish immune tolerance for sperm and an embryo/fetus...

  8. Nutrient depletion modifies cell wall adsorption activity of wine yeast.

    Science.gov (United States)

    Sidari, R; Caridi, A

    2016-06-01

    Yeast cell wall is a structure that helps yeasts to manage and respond to many environmental stresses. The mannosylphosphorylation is a modification in response to stress that provides the cell wall with negative charges able to bind compounds present in the environment. Phenotypes related to the cell wall modification such as the filamentous growth in Saccharomyces cerevisiae are affected by nutrient depletion. The present work aimed at describing the effect of carbon and/or nitrogen limitation on the aptitude of S. cerevisiae strains to bind coloured polyphenols. Carbon- and nitrogen-rich or deficient media supplemented with grape polyphenols were used to simulate different grape juice conditions-early, mid, 'adjusted' for nitrogen, and late fermentations. In early fermentation condition, the R+G+B values range from 106 (high adsorption, strain Sc1128) to 192 (low adsorption, strain Σ1278b), in mid-fermentation the values range from 111 (high adsorption, strain Sc1321) to 258 (low adsorption, strain Sc2306), in 'adjusted' for nitrogen conditions the values range from 105 (high adsorption, strain Sc1321) to 194 (low adsorption, strain Sc2306) while in late fermentation conditions the values range from 101 (high adsorption, strain Sc384) to 293 (low adsorption, strain Sc2306). The effect of nutrient availability is not univocal for all the strains and the different media tested modified the strains behaviour. In all the media the strains show significant differences. Results demonstrate that wine yeasts decrease/increase their parietal adsorption activity according to the nutrient availability. The wide range of strain variability observed could be useful in selecting wine starters. PMID:27116955

  9. Cell mediated immunity to fungi: a reassessment.

    Science.gov (United States)

    Romani, Luigina

    2008-09-01

    Protective immunity against fungal pathogens is achieved by the integration of two distinct arms of the immune system, the innate and adaptive responses. Innate and adaptive immune responses are intimately linked and controlled by sets of molecules and receptors that act to generate the most effective form of immunity for protection against fungal pathogens. The decision of how to respond will still be primarily determined by interactions between pathogens and cells of the innate immune system, but the actions of T cells will feed back into this dynamic equilibrium to regulate the balance between tolerogenic and inflammatory responses. In the last two decades, the immunopathogenesis of fungal infections and fungal diseases was explained primarily in terms of Th1/Th2 balance. Although Th1 responses driven by the IL-12/IFN-gamma axis are central to protection against fungi, other cytokines and T cell-dependent pathways have come of age. The newly described Th17 developmental pathway may play an inflammatory role previously attributed to uncontrolled Th1 responses and serves to accommodate the seemingly paradoxical association of chronic inflammatory responses with fungal persistence in the face of an ongoing inflammation. Regulatory T cells in their capacity to inhibit aspects of innate and adaptive antifungal immunity have become an integral component of immune resistance to fungi, and provide the host with immune defense mechanisms adequate for protection, without necessarily eliminating fungal pathogens which would impair immune memory--or causing an unacceptable level of tissue damage. The enzyme indoleamine 2,3-dioxygenase and tryptophan metabolites contribute to immune homeostasis by inducing Tregs and taming overzealous or heightened inflammatory responses.

  10. T cells and the humoral immune system

    NARCIS (Netherlands)

    W.B. van Muiswinkel (Willem)

    1975-01-01

    textabstractLymphoid cells and macrophages play an important role in the development and rnaintance of humoral and cellular immunity in mammals. The lymphoid cells in the peripheral lymphoid organs are divided into two major classes: (1) thymus-derived lymphocytes or T cells and (2) bursa-equivalent

  11. Effect of local macrophage depletion on cellular immunity and tolerance evoked by corneal allografts.

    NARCIS (Netherlands)

    Slegers, TP; Rooijen, van N.; Rij, van G.L.; Streilein, JW

    2003-01-01

    Corneal graft rejection can be prevented by local macrophage depletion, via subconjunctival injections with clodronate liposomes. To unravel the underlying immunological mechanism responsible for prolonged graft survival in this circumstance, the effect of this regimen on induction of donor-specific

  12. Plague Bacteria Target Immune Cells During Infection

    OpenAIRE

    Marketon, Melanie M.; DePaolo, R. William; DeBord, Kristin L.; Jabri, Bana; Schneewind, Olaf

    2005-01-01

    The plague is caused by the bacterium Yersinia pestis. Plague bacteria are thought to inject effector Yop proteins into host cells via the type III pathway. The identity of the host cells targeted for injection during plague infection is unknown. We found, using Yop β-lactamase hybrids and fluorescent staining of live cells from plague-infected animals, that Y. pestis selected immune cells for injection. In vivo, dendritic cells, macrophages, and neutrophils were injected most frequently, whe...

  13. Giardia duodenalis arginine deiminase modulates the phenotype and cytokine secretion of human dendritic cells by depletion of arginine and formation of ammonia.

    Science.gov (United States)

    Banik, Stefanie; Renner Viveros, Pablo; Seeber, Frank; Klotz, Christian; Ignatius, Ralf; Aebischer, Toni

    2013-07-01

    Depletion of arginine is a recognized strategy that pathogens use to evade immune effector mechanisms. Depletion depends on microbial enzymes such as arginases, which are considered virulence factors. The effect is mostly interpreted as being a consequence of successful competition with host enzymes for the substrate. However, both arginases and arginine deiminases (ADI) have been associated with pathogen virulence. Both deplete arginine, but their reaction products differ. An ADI has been implicated in the virulence of Giardia duodenalis, an intestinal parasite that infects humans and animals, causing significant morbidity. Dendritic cells (DC) play a critical role in host defense and also in a murine G. duodenalis infection model. The functional properties of these innate immune cells depend on the milieu in which they are activated. Here, the dependence of the response of these cells on arginine was studied by using Giardia ADI and lipopolysaccharide-stimulated human monocyte-derived DC. Arginine depletion by ADI significantly increased tumor necrosis factor alpha and decreased interleukin-10 (IL-10) and IL-12p40 secretion. It also reduced the upregulation of surface CD83 and CD86 molecules, which are involved in cell-cell interactions. Arginine depletion also reduced the phosphorylation of S6 kinase in DC, suggesting the involvement of the mammalian target of rapamycin signaling pathway. The changes were due to arginine depletion and the formation of reaction products, in particular, ammonium ions. Comparison of NH(4)(+) and urea revealed distinct immunomodulatory activities of these products of deiminases and arginases, respectively. The data suggest that a better understanding of the role of arginine-depleting pathogen enzymes for immune evasion will have to take enzyme class and reaction products into consideration.

  14. Giardia duodenalis Arginine Deiminase Modulates the Phenotype and Cytokine Secretion of Human Dendritic Cells by Depletion of Arginine and Formation of Ammonia

    Science.gov (United States)

    Banik, Stefanie; Renner Viveros, Pablo; Seeber, Frank; Klotz, Christian; Ignatius, Ralf

    2013-01-01

    Depletion of arginine is a recognized strategy that pathogens use to evade immune effector mechanisms. Depletion depends on microbial enzymes such as arginases, which are considered virulence factors. The effect is mostly interpreted as being a consequence of successful competition with host enzymes for the substrate. However, both arginases and arginine deiminases (ADI) have been associated with pathogen virulence. Both deplete arginine, but their reaction products differ. An ADI has been implicated in the virulence of Giardia duodenalis, an intestinal parasite that infects humans and animals, causing significant morbidity. Dendritic cells (DC) play a critical role in host defense and also in a murine G. duodenalis infection model. The functional properties of these innate immune cells depend on the milieu in which they are activated. Here, the dependence of the response of these cells on arginine was studied by using Giardia ADI and lipopolysaccharide-stimulated human monocyte-derived DC. Arginine depletion by ADI significantly increased tumor necrosis factor alpha and decreased interleukin-10 (IL-10) and IL-12p40 secretion. It also reduced the upregulation of surface CD83 and CD86 molecules, which are involved in cell-cell interactions. Arginine depletion also reduced the phosphorylation of S6 kinase in DC, suggesting the involvement of the mammalian target of rapamycin signaling pathway. The changes were due to arginine depletion and the formation of reaction products, in particular, ammonium ions. Comparison of NH4+ and urea revealed distinct immunomodulatory activities of these products of deiminases and arginases, respectively. The data suggest that a better understanding of the role of arginine-depleting pathogen enzymes for immune evasion will have to take enzyme class and reaction products into consideration. PMID:23589577

  15. Role of regulatory T-cells in immunization strategies involving a recombinant alphavirus vector system

    NARCIS (Netherlands)

    Walczak, Mateusz; Regts, Joke; van Oosterhout, Antoon J. M.; Boon, Louis; Wilschut, Jan; Nijman, Hans W.; Daemen, Toos

    2011-01-01

    Background: Regulatory T-cells (Treg) hamper immune responses elicited by cancer vaccines. Therefore, depletion of Treg is being used to improve the outcome of vaccinations. Methods: We studied whether an alphavirus vector-based immunotherapeutic vaccine changes the number and/or activity of Treg an

  16. Influence of 5 major Salmonella pathogenicity islands on NK cell depletion in mice infected with Salmonella enterica serovar Enteritidis

    Directory of Open Access Journals (Sweden)

    Ondrackova Petra

    2010-03-01

    Full Text Available Abstract Background In this study we were interested in the colonisation and early immune response of Balb/C mice to infection with Salmonella Enteritidis and isogenic pathogenicity island free mutants. Results The virulence of S. Enteritidis for Balb/C mice was exclusively dependent on intact SPI-2. Infections with any of the mutants harbouring SPI-2 (including the mutant in which we left only SPI-2 but removed SPI-1, SPI-3, SPI-4 and SPI-5 resulted in fatalities, liver injures and NK cell depletion from the spleen. The infection was of minimal influence on counts of splenic CD4 CD8 T lymphocytes and γδ T-lymphocytes although a reduced ability of splenic lymphocytes to respond to non-specific mitogens indicated general immunosuppression in mice infected with SPI-2 positive S. Enteritidis mutants. Further investigations showed that NK cells were depleted also in blood but not in the caecal lamina propria. However, NK cell depletion was not directly associated with the presence of SPI-2 and was rather an indicator of virulence or avirulence of a particular mutant because the depletion was not observed in mice infected with other attenuated mutants such as lon and rfaL. Conclusions The virulence of S. Enteritidis for Balb/C mice is exclusively dependent on the presence of SPI-2 in its genome, and a major hallmark of the infection in terms of early changes in lymphocyte populations is the depletion of NK cells in spleen and blood. The decrease of NK cells in circulation can be used as a marker of attenuation of S. Enteritidis mutants for Balb/C mice.

  17. Myeloid cells in tumour-immune interactions.

    Science.gov (United States)

    Kareva, Irina; Berezovskaya, Faina; Castillo-Chavez, Carlos

    2010-07-01

    Despite highly developed specific immune responses, tumour cells often manage to escape recognition by the immune system, continuing to grow uncontrollably. Experimental work suggests that mature myeloid cells may be central to the activation of the specific immune response. Recognition and subsequent control of tumour growth by the cells of the specific immune response depend on the balance between immature (ImC) and mature (MmC) myeloid cells in the body. However, tumour cells produce cytokines that inhibit ImC maturation, altering the balance between ImC and MmC. Hence, the focus of this manuscript is on the study of the potential role of this inhibiting mechanism on tumour growth dynamics. A conceptual predator-prey type model that incorporates the dynamics and interactions of tumour cells, CD8(+) T cells, ImC and MmC is proposed in order to address the role of this mechanism. The prey (tumour) has a defence mechanism (blocking the maturation of ImC) that prevents the predator (immune system) from recognizing it. The model, a four-dimensional nonlinear system of ordinary differential equations, is reduced to a two-dimensional system using time-scale arguments that are tied to the maturation rate of ImC. Analysis shows that the model is capable of supporting biologically reasonable patterns of behaviour depending on the initial conditions. A range of parameters, where healing without external influences can occur, is identified both qualitatively and quantitatively.

  18. Autophagy in immune cell regulation and dysregulation.

    Science.gov (United States)

    Chaturvedi, Akanksha; Pierce, Susan K

    2009-09-01

    Autophagy is an ancient pathway required for cell and tissue homeostasis and differentiation. Initially thought to be a process leading to cell death, autophagy is currently viewed as a beneficial catabolic process that promotes cell survival under starvation conditions by sequestering components of the cytoplasm, including misfolded proteins, protein aggregates, and damaged organelles, and targeting them for lysosome-mediated degradation. In this way, autophagy plays a role in maintaining a balance between degradation and recycling of cellular material. The importance of autophagy is underscored by the fact that malfunctioning of this pathway results in neurodegeneration, cancer, susceptibility to microbial infection, and premature aging. Autophagy occurs in almost all cell types, including immune cells. Recent advances in the field suggest that autophagy plays a central role in regulating the immune system at multiple levels. In this review, we focus on recent developments in the area of autophagy-mediated modulation of immune responses. PMID:19671376

  19. Targeting epidermal Langerhans cells by epidermal powder immunization

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Immune reactions to foreign or self-antigens lead to protective immunity and, sometimes, immune disorders such as allergies and autoimmune diseases. Antigen presenting cells (APC) including epidermal Langerhans cells (LCs) play an important role in the course and outcome of the immune reactions. Epidermal powder immunization (EPI) is a technology that offers a tool to manipulate the LCs and the potential to harness the immune reactions towards prevention and treatment of infectious diseases and immune disorders.

  20. Myeloid-derived Suppressor Cells Inhibit T Cell Activation by Depleting Cystine and Cysteine

    OpenAIRE

    Minu K Srivastava; Sinha, Pratima; Clements, Virginia K.; Rodriguez, Paulo; Ostrand-Rosenberg, Suzanne

    2009-01-01

    Myeloid-derived suppressor cells (MDSC) are present in most cancer patients and are potent inhibitors of T-cell-mediated anti-tumor immunity. Their inhibitory activity is attributed to production of arginase, reactive oxygen species, inducible nitric oxide synthase, and IL-10. We now report that MDSC also block T cell activation by sequestering cystine and limiting the availability of cysteine. Cysteine is an essential amino acid for T cell activation because T cells lack cystathionase, which...

  1. mtDNA depletion confers specific gene expression profiles in human cells grown in culture and in xenograft

    Directory of Open Access Journals (Sweden)

    Ramaswamy Krishna

    2008-11-01

    Full Text Available Abstract Background Interactions between the gene products encoded by the mitochondrial and nuclear genomes play critical roles in eukaryotic cellular function. However, the effects mitochondrial DNA (mtDNA levels have on the nuclear transcriptome have not been defined under physiological conditions. In order to address this issue, we characterized the gene expression profiles of A549 lung cancer cells and their mtDNA-depleted ρ0 counterparts grown in culture and as tumor xenografts in immune-deficient mice. Results Cultured A549 ρ0 cells were respiration-deficient and showed enhanced levels of transcripts relevant to metal homeostasis, initiation of the epithelial-mesenchymal transition, and glucuronidation pathways. Several well-established HIF-regulated transcripts showed increased or decreased abundance relative to the parental cell line. Furthermore, growth in culture versus xenograft has a significantly greater influence on expression profiles, including transcripts involved in mitochondrial structure and both aerobic and anaerobic energy metabolism. However, both in vitro and in vivo, mtDNA levels explained the majority of the variance observed in the expression of transcripts in glucuronidation, tRNA synthetase, and immune surveillance related pathways. mtDNA levels in A549 xenografts also affected the expression of genes, such as AMACR and PHYH, involved in peroxisomal lipid metabolic pathways. Conclusion We have identified mtDNA-dependent gene expression profiles that are shared in cultured cells and in xenografts. These profiles indicate that mtDNA-depleted cells could provide informative model systems for the testing the efficacy of select classes of therapeutics, such as anti-angiogenesis agents. Furthermore, mtDNA-depleted cells grown culture and in xenografts provide a powerful means to investigate possible relationships between mitochondrial activity and gene expression profiles in normal and pathological cells.

  2. Accelerated cellular senescence phenotype of GAPDH-depleted human lung carcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Phadke, Manali; Krynetskaia, Natalia [Temple University School of Pharmacy, Philadelphia, PA 19140 (United States); Mishra, Anurag [Jayne Haines Center for Pharmacogenomics, Temple University School of Pharmacy, Philadelphia, PA 19140 (United States); Krynetskiy, Evgeny, E-mail: ekrynets@temple.edu [Temple University School of Pharmacy, Philadelphia, PA 19140 (United States); Jayne Haines Center for Pharmacogenomics, Temple University School of Pharmacy, Philadelphia, PA 19140 (United States)

    2011-07-29

    Highlights: {yields} We examined the effect of glyceraldehyde 3-phosphate (GAPDH) depletion on proliferation of human carcinoma A549 cells. {yields} GAPDH depletion induces accelerated senescence in tumor cells via AMPK network, in the absence of DNA damage. {yields} Metabolic and genetic rescue experiments indicate that GAPDH has regulatory functions linking energy metabolism and cell cycle. {yields} Induction of senescence in LKB1-deficient lung cancer cells via GAPDH depletion suggests a novel strategy to control tumor cell proliferation. -- Abstract: Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) is a pivotal glycolytic enzyme, and a signaling molecule which acts at the interface between stress factors and the cellular apoptotic machinery. Earlier, we found that knockdown of GAPDH in human carcinoma cell lines resulted in cell proliferation arrest and chemoresistance to S phase-specific cytotoxic agents. To elucidate the mechanism by which GAPDH depletion arrests cell proliferation, we examined the effect of GAPDH knockdown on human carcinoma cells A549. Our results show that GAPDH-depleted cells establish senescence phenotype, as revealed by proliferation arrest, changes in morphology, SA-{beta}-galactosidase staining, and more than 2-fold up-regulation of senescence-associated genes DEC1 and GLB1. Accelerated senescence following GAPDH depletion results from compromised glycolysis and energy crisis leading to the sustained AMPK activation via phosphorylation of {alpha} subunit at Thr172. Our findings demonstrate that GAPDH depletion switches human tumor cells to senescent phenotype via AMPK network, in the absence of DNA damage. Rescue experiments using metabolic and genetic models confirmed that GAPDH has important regulatory functions linking the energy metabolism and the cell cycle networks. Induction of senescence in LKB1-deficient non-small cell lung cancer cells via GAPDH depletion suggests a novel strategy to control tumor cell proliferation.

  3. HIV-dependent depletion of influenza-specific memory B cells impacts B cell responsiveness to seasonal influenza immunisation

    Science.gov (United States)

    Wheatley, Adam K.; Kristensen, Anne B.; Lay, William N.; Kent, Stephen J.

    2016-01-01

    Infection with HIV drives significant alterations in B cell phenotype and function that can markedly influence antibody responses to immunisation. Anti-retroviral therapy (ART) can partially reverse many aspects of B cell dysregulation, however complete normalisation of vaccine responsiveness is not always observed. Here we examine the effects of underlying HIV infection upon humoral immunity to seasonal influenza vaccines. Serological and memory B cell responses were assessed in 26 HIV+ subjects receiving ART and 30 healthy controls immunised with the 2015 Southern Hemisphere trivalent inactivated influenza vaccine (IIV3). Frequencies and phenotypes of influenza hemagglutinin (HA)-specific B cells were assessed by flow cytometry using recombinant HA probes. Serum antibody was measured using hemagglutination inhibition assays. Serological responses to IIV3 were comparable between HIV+ and HIV− subjects. Likewise, the activation and expansion of memory B cell populations specific for vaccine-component influenza strains was observed in both cohorts, however peak frequencies were diminished in HIV+ subjects compared to uninfected controls. Lower circulating frequencies of memory B cells recognising vaccine-component and historical influenza strains were observed in HIV+ subjects at baseline, that were generally restored to levels comparable with HIV− controls post-vaccination. HIV infection is therefore associated with depletion of selected HA-specific memory B cell pools. PMID:27220898

  4. Prevention of immunodeficiency virus induced CD4+ T-cell depletion by prior infection with a non-pathogenic virus

    International Nuclear Information System (INIS)

    Immune dysregulation initiated by a profound loss of CD4+ T-cells is fundamental to HIV-induced pathogenesis. Infection of domestic cats with a non-pathogenic lentivirus prevalent in the puma (puma lentivirus, PLV or FIVPCO) prevented peripheral blood CD4+ T-cell depletion caused by subsequent virulent FIV infection. Maintenance of this critical population was not associated with a significant decrease in FIV viremia, lending support to the hypothesis that direct viral cytopathic effect is not the primary cause of immunodeficiency. Although this approach was analogous to immunization with a modified live vaccine, correlates of immunity such as a serum-neutralizing antibody or virus-specific T-cell proliferative response were not found in protected animals. Differences in cytokine transcription profile, most notably in interferon gamma, were observed between the protected and unprotected groups. These data provide support for the importance of non-adaptive enhancement of the immune response in the prevention of CD4+ T-cell loss

  5. 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.

  6. CD4+ T cells mediate mucosal and systemic immune responses to experimental hookworm infection

    Science.gov (United States)

    DONDJI, B.; SUN, T.; BUNGIRO, R. D.; VERMEIRE, J. J.; HARRISON, L. M.; BIFULCO, C.; CAPPELLO, M.

    2011-01-01

    SUMMARY Hookworm infection is associated with anaemia and malnutrition in many resource-limited countries. Ancylostoma hookworms have previously been shown to modulate host cellular immune responses through multiple mechanisms, including reduced mitogen-mediated lymphocyte proliferation, impaired antigen presentation/processing, and relative reductions in CD4+ T cells in the spleen and mesenteric lymph nodes. Syrian hamsters were depleted of CD4+ for up to 9 days following intraperitoneal injection (200 μg) of a murine anti-mouse CD4 monoclonal IgG (clone GK1·5). CD4+ T-cell-depleted hamsters infected with the hookworm Ancylostoma ceylanicum exhibited a threefold higher mean intestinal worm burden and more severe anaemia than animals that received isotype control IgG. In addition, depletion of CD4+ T cells was associated with impaired cellular and humoral (serum and mucosal) immune responses to hookworm antigens. These data demonstrate an effector role for CD4+ T cells in hookworm immunity and disease pathogenesis. Ultimately, these studies may yield important insights into the relationship between intestinal nematode infections and diseases that are associated with CD4+ T-cell depletion, including HIV. PMID:20500671

  7. Targeting B cells in immune-mediated inflammatory disease: A comprehensive review of mechanisms of action and identification of biomarkers

    NARCIS (Netherlands)

    T. Dörner; N. Kinnman; P.P. Tak

    2010-01-01

    B cell-depletion therapy, particularly using anti-CD20 treatment, has provided proof of concept that targeting B cells and the humoral response may result in clinical improvements in immune-mediated inflammatory disease. In this review, the mechanisms of action of B cell-targeting drugs are investig

  8. Aluminum toxicity and Ca depletion may enhance cell death of tobacco cells via similar syndrome.

    Science.gov (United States)

    Basset, Refat Abdel; Matsumoto, Hideaki

    2008-05-01

    The main objective of this work is to find out whether aluminum (Al) toxicity and Ca depletion cause cell death of tobacco cells via similar sequence of events. Tobacco cell suspension culture exhibited maximum fresh weight in the presence of a wide range of Ca concentrations between 0.1-1.0 mM whereas higher concentrations (>1.0-5.0 mM) gradually lowered cell fresh weight. However, this decrease in fresh weight does not imply a negative impact on cell viability since cell growth recommenced in fresh MS medium with rates mostly higher than those of low Ca. In addition, high Ca seems to be crucial for survival of Al-treated cells. On the other side, tobacco cells exhibited extreme sensitivity to complete deprivation of Ca. Without Ca, cells could not survive for 18 h and substantially lost their growth capability. Evans blue uptake proved membrane damage of Ca-depleted same as Al-treated cells; relative to maintained membrane intactness of calcium-supplemented (control) ones. Percentage of membrane damage and the growth capability (survival) of tobacco cells exhibited a clear negative correlation.Alterations in growth (fresh weight per aliquot) could not be ascribed neither to cell number nor to decreased dry matter allocation (dry weight/fresh weight percentage) but was mainly due to decreased cellular water content. In this context, Ca-depleted cells lost about half their original water content while 100 microM Al-treated ones retained most of it (ca 87%). This represented the single difference between the two treatments (discussed in the text). Nevertheless, such high water content of the Al-treated cells seems physiologically useless since it did not result in improved viability. Similarities, however, included negligible levels of growth capability, maximum levels of membrane damage, and comparable amounts of NO(3) (-) efflux. As well, both types of treatments led to a sharp decline in osmotic potential that is, in turn, needed for water influx. The above

  9. Dissipative Particle Dynamics Simulation of Polymer- and Cell-Wall Depletion in Micro-Channels

    Science.gov (United States)

    Fedosov, Dmitry A.; Caswell, Bruce; Em Karniadakis, George

    2008-07-01

    A rising interest in physics of biological systems stimulates a great number of experiments and numerical simulations involving a variety of biological entities. These include bio-polymers and bio-molecules, real organism vesicles and capsules, artificial vesicles used in drug delivery and cells. Macromolecules, vesicles and cells are subject to wall depletion layers observed near solid-fluid interfaces. In the case of red blood cells depletion is often called the cell-free layer and is observed near blood vessel walls. We employ Dissipative Particle Dynamics (DPD) to model depletion layers in biological systems. In case of bio-polymers the simulated depletion layers compare well with the asymptotic lattice theory solution of depletion near a repulsive wall. Vesicles and cells are modeled as coarse-grained cell membranes described by in-plane viscoelastic energy, bending energy, area and volume constraints. We investigate cell-wall depletion for cells having vesicle-like shape and red blood cells, and we correlate our results with membrane coarse-graining and with material properties such as membrane stretching and bending stiffness.

  10. Epigenetic Dysfunction in Turner Syndrome Immune Cells.

    Science.gov (United States)

    Thrasher, Bradly J; Hong, Lee Kyung; Whitmire, Jason K; Su, Maureen A

    2016-05-01

    Turner syndrome (TS) is a chromosomal condition associated with partial or complete absence of the X chromosome that involves characteristic findings in multiple organ systems. In addition to well-known clinical characteristics such as short stature and gonadal failure, TS is also associated with T cell immune alterations and chronic otitis media, suggestive of a possible immune deficiency. Recently, ubiquitously transcribed tetratricopeptide repeat on the X chromosome (UTX), a histone H3 lysine 27 (H3K27) demethylase, has been identified as a downregulated gene in TS immune cells. Importantly, UTX is an X-linked gene that escapes X-chromosome inactivation and thus is haploinsufficient in TS. Mice with T cell-specific UTX deficiency have impaired clearance of chronic viral infection due to decreased frequencies of T follicular helper (Tfh) cells, which are critical for B cell antibody generation. In parallel, TS patients have decreased Tfh frequencies in peripheral blood. Together, these findings suggest that haploinsufficiency of the X-linked UTX gene in TS T cells underlies an immune deficit, which may manifest as increased predisposition to chronic otitis media.

  11. Epigenetic Dysfunction in Turner Syndrome Immune Cells.

    Science.gov (United States)

    Thrasher, Bradly J; Hong, Lee Kyung; Whitmire, Jason K; Su, Maureen A

    2016-05-01

    Turner syndrome (TS) is a chromosomal condition associated with partial or complete absence of the X chromosome that involves characteristic findings in multiple organ systems. In addition to well-known clinical characteristics such as short stature and gonadal failure, TS is also associated with T cell immune alterations and chronic otitis media, suggestive of a possible immune deficiency. Recently, ubiquitously transcribed tetratricopeptide repeat on the X chromosome (UTX), a histone H3 lysine 27 (H3K27) demethylase, has been identified as a downregulated gene in TS immune cells. Importantly, UTX is an X-linked gene that escapes X-chromosome inactivation and thus is haploinsufficient in TS. Mice with T cell-specific UTX deficiency have impaired clearance of chronic viral infection due to decreased frequencies of T follicular helper (Tfh) cells, which are critical for B cell antibody generation. In parallel, TS patients have decreased Tfh frequencies in peripheral blood. Together, these findings suggest that haploinsufficiency of the X-linked UTX gene in TS T cells underlies an immune deficit, which may manifest as increased predisposition to chronic otitis media. PMID:27039394

  12. Measurement of myeloid cell immune suppressive activity.

    Science.gov (United States)

    Dolcetti, Luigi; Peranzoni, Elisa; Bronte, Vincenzo

    2010-11-01

    This unit presents simple methods to assess the immunosuppressive properties of immunoregulatory cells of myeloid origin, such as myeloid-derived suppressor cells (MDSCs), both in vitro and in vivo. These methods are general and could be adapted to test the impact of different suppressive populations on T cell activation, proliferation, and cytotoxic activity; moreover they could be useful to assess the influence exerted on immune suppressive pathways by genetic modifications, chemical inhibitors, and drugs.

  13. Depletion of regulatory T cells augments a vaccine-induced T effector cell response against the liver-stage of malaria but fails to increase memory.

    Directory of Open Access Journals (Sweden)

    Maria del Rosario Espinoza Mora

    Full Text Available Regulatory T cells (T(reg have been shown to restrict vaccine-induced T cell responses in different experimental models. In these studies CD4(+CD25(+ T(reg were depleted using monoclonal antibodies against CD25, which might also interfere with CD25 on non-regulatory T cell populations and would have no effect on Foxp3(+CD25(- T(reg. To obtain more insights in the specific function of T(reg during vaccination we used mice that are transgenic for a bacterial artificial chromosome expressing a diphtheria toxin (DT receptor-eGFP fusion protein under the control of the foxp3 gene locus (depletion of regulatory T cell mice; DEREG. As an experimental vaccine-carrier recombinant Bordetella adenylate cyclase toxoid fused with a MHC-class I-restricted epitope of the circumsporozoite protein (ACT-CSP of Plasmodium berghei (Pb was used. ACT-CSP was shown by us previously to introduce the CD8+ epitope of Pb-CSP into the MHC class I presentation pathway of professional antigen-presenting cells (APC. Using this system we demonstrate here that the number of CSP-specific T cells increases when T(reg are depleted during prime but also during boost immunization. Importantly, despite this increase of T effector cells no difference in the number of antigen-specific memory cells was observed.

  14. Effects of T-Cell Depletion on Allogeneic Hematopoietic Stem Cell Transplantation Outcomes in AML Patients

    Directory of Open Access Journals (Sweden)

    Gabriela Soriano Hobbs

    2015-03-01

    Full Text Available Graft versus host disease (GVHD remains one of the leading causes of morbidity and mortality associated with conventional allogeneic hematopoietic stem cell transplantation (HCT. The use of T-cell depletion significantly reduces this complication. Recent prospective and retrospective data suggest that, in patients with AML in first complete remission, CD34+ selected grafts afford overall and relapse-free survival comparable to those observed in recipients of conventional grafts, while significantly decreasing GVHD. In addition, CD34+ selected grafts allow older patients, and those with medical comorbidities or with only HLA-mismatched donors to successfully undergo transplantation. Prospective data are needed to further define which groups of patients with AML are most likely to benefit from CD34+ selected grafts. Here we review the history of T-cell depletion in AML, and techniques used. We then summarize the contemporary literature using CD34+ selection in recipients of matched or partially mismatched donors (7/8 or 8/8 HLA-matched, and provide a summary of the risks and benefits of using T-cell depletion.

  15. Immunological characteristics and T-cell receptor clonal diversity in children with systemic juvenile idiopathic arthritis undergoing T-cell-depleted autologous stem cell transplantation.

    Science.gov (United States)

    Wu, Qiong; Pesenacker, Anne M; Stansfield, Alka; King, Douglas; Barge, Dawn; Foster, Helen E; Abinun, Mario; Wedderburn, Lucy R

    2014-06-01

    Children with systemic Juvenile Idiopathic Arthritis (sJIA), the most severe subtype of JIA, are at risk from destructive polyarthritis and growth failure, and corticosteroids as part of conventional treatment can result in osteoporosis and growth delay. In children where there is failure or toxicity from drug therapies, disease has been successfully controlled by T-cell-depleted autologous stem cell transplantation (ASCT). At present, the immunological basis underlying remission after ASCT is unknown. Immune reconstitution of T cells, B cells, natural killer cells, natural killer T cells and monocytes, in parallel with T-cell receptor (TCR) diversity by analysis of the β variable region (TCRVb) complementarity determining region-3 (CDR3) using spectratyping and sequencing, were studied in five children with sJIA before and after ASCT. At time of follow up (mean 11.5 years), four patients remain in complete remission, while one child relapsed within 1 month of transplant. The CD8(+) TCRVb repertoire was highly oligoclonal early in immune reconstitution and re-emergence of pre-transplant TCRVb CDR3 dominant peaks was observed after transplant in certain TCRVb families. Further, re-emergence of pre-ASCT clonal sequences in addition to new sequences was identified after transplant. These results suggest that a chimeric TCR repertoire, comprising T-cell clones developed before and after transplant, can be associated with clinical remission from severe arthritis. PMID:24405357

  16. [Dendritic cells and interaction with other cell types. Immune tolerance].

    Science.gov (United States)

    Guerder, S

    2001-07-01

    T cell tolerance to self antigen is mainly established in the thymus were self-reactive T cells are deleted. Interdigitating dendritic cells and medulary epithelial cells are directly involved in the deletion process. Some self-reactive T cells escape, however this thymic censorship and enter the peripheral pool of naive T cells. Multiple mechanisms are also at play in the periphery to control this potentially armfull T cells, this include deletion and immune deviation.

  17. Platelets as immune cells in infectious diseases.

    Science.gov (United States)

    Speth, Cornelia; Löffler, Jürgen; Krappmann, Sven; Lass-Flörl, Cornelia; Rambach, Günter

    2013-11-01

    Platelets have been shown to cover a broad range of functions. Besides their role in hemostasis, they have immunological functions and thus participate in the interaction between pathogens and host defense. Platelets have a broad repertoire of receptor molecules that enable them to sense invading pathogens and infection-induced inflammation. Consequently, platelets exert antimicrobial effector mechanisms, but also initiate an intense crosstalk with other arms of the innate and adaptive immunity, including neutrophils, monocytes/macrophages, dendritic cells, B cells and T cells. There is a fragile balance between beneficial antimicrobial effects and detrimental reactions that contribute to the pathogenesis, and many pathogens have developed mechanisms to influence these two outcomes. This review aims to highlight aspects of the interaction strategies between platelets and pathogenic bacteria, viruses, fungi and parasites, in addition to the subsequent networking between platelets and other immune cells, and the relevance of these processes for the pathogenesis of infections.

  18. Regulatory T cells in cutaneous immune responses.

    OpenAIRE

    Honda, Tetsuya; MIYACHI, YOSHIKI; Kabashima, Kenji

    2011-01-01

    Regulatory T cells (Treg) are a subset of T cells with strong immunosuppressive activity. In the skin, it has recently been revealed that Treg play important roles not only in the maintenance of skin homeostasis but also in the regulation of the immune responses, such as contact hypersensitivity and atopic dermatitis. Furthermore, the skin plays important roles in the induction of Treg in the periphery. In this review, we will provide an overview of the mechanism of Treg-mediated immunosuppre...

  19. CD4+CD25+ regulatory T cell depletion modulates anxiety and depression-like behaviors in mice.

    Directory of Open Access Journals (Sweden)

    Soo-Jeong Kim

    Full Text Available Stress has been shown to suppress immune function and increase susceptibility to inflammatory disease and psychiatric disease. CD4(+CD25(+ regulatory T (Treg cells are prominent in immune regulation. This study was conducted to determine if anti-CD25 antibody (Ab mediated depletion of Treg cells in mice susceptibility to stress-induced development of depression-like behaviors, as well as immunological and neurochemical activity. To accomplish this, an elevated plus-maze test (EPM, tail suspension test (TST, and forced swim test (FST were used to examine depression-like behaviors upon chronic immobilization stress. Immune imbalance status was observed based on analysis of serum cytokines using a mouse cytometric bead array in conjunction with flow cytometry and changes in the levels of serotonin (5-HT and dopamine (DA in the brain were measured by high performance liquid chromatography (HPLC. The time spent in the open arms of the EPM decreased significantly and the immobility time in the FST increased significantly in the anti-CD25 Ab-treated group when compared with the non stressed wild-type group. In addition, interlukin-6 (IL-6, tumor necrosis factor-á (TNF-á, interlukin-2 (IL-2, interferon-gamma (IFN-γ, interlukin-4 (IL-4 and interlukin-17A (IL-17A concentrations were significantly upregulated in the stressed anti-CD25 Ab-treated group when compared with the non stressed wild-type group. Furthermore, the non stressed anti-CD25 Ab-treated group displayed decreased 5-HT levels within the hippocampus when compared with the non stressed wild-type group. These results suggest that CD4(+CD25(+ Treg cell depletion modulated alterations in depressive behavior, cytokine and monoaminergic activity. Therefore, controlling CD4(+CD25(+ Treg cell function during stress may be a potent therapeutic strategy for the treatment of depression-like symptoms.

  20. Hematopoietic Stem and Immune Cells in Chronic HIV Infection

    OpenAIRE

    Jielin Zhang; Clyde Crumpacker

    2015-01-01

    Hematopoietic stem cell (HSC) belongs to multipotent adult somatic stem cells. A single HSC can reconstitute the entire blood system via self-renewal, differentiation into all lineages of blood cells, and replenishment of cells lost due to attrition or disease in a person's lifetime. Although all blood and immune cells derive from HSC, immune cells, specifically immune memory cells, have the properties of HSC on self-renewal and differentiation into lineage effector cells responding to the in...

  1. 6-Thioguanine-loaded polymeric micelles deplete myeloid-derived suppressor cells and enhance the efficacy of T cell immunotherapy in tumor-bearing mice.

    Science.gov (United States)

    Jeanbart, Laura; Kourtis, Iraklis C; van der Vlies, André J; Swartz, Melody A; Hubbell, Jeffrey A

    2015-08-01

    Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid cells that suppress effector T cell responses and can reduce the efficacy of cancer immunotherapies. We previously showed that ultra-small polymer nanoparticles efficiently drain to the lymphatics after intradermal injection and target antigen-presenting cells, including Ly6c(hi) Ly6g(-) monocytic MDSCs (Mo-MDSCs), in skin-draining lymph nodes (LNs) and spleen. Here, we developed ultra-small polymer micelles loaded with 6-thioguanine (MC-TG), a cytotoxic drug used in the treatment of myelogenous leukemia, with the aim of killing Mo-MDSCs in tumor-bearing mice and thus enhancing T cell-mediated anti-tumor responses. We found that 2 days post-injection in tumor-bearing mice (B16-F10 melanoma or E.G7-OVA thymoma), MC-TG depleted Mo-MDSCs in the spleen, Ly6c(lo) Ly6g(+) granulocytic MDSCs (G-MDSCs) in the draining LNs, and Gr1(int) Mo-MDSCs in the tumor. In both tumor models, MC-TG decreased the numbers of circulating Mo- and G-MDSCs, as well as of Ly6c(hi) macrophages, for up to 7 days following a single administration. MDSC depletion was dose dependent and more effective with MC-TG than with equal doses of free TG. Finally, we tested whether this MDSC-depleting strategy might enhance cancer immunotherapies in the B16-F10 melanoma model. We found that MC-TG significantly improved the efficacy of adoptively transferred, OVA-specific CD8(+) T cells in melanoma cells expressing OVA. These findings highlight the capacity of MC-TG in depleting MDSCs in the tumor microenvironment and show promise in promoting anti-tumor immunity when used in combination with T cell immunotherapies. PMID:25982370

  2. The Role of Plasmacytoid Dendritic Cells in Innate and Adaptive Immune Responses against Alpha Herpes Virus Infections

    Directory of Open Access Journals (Sweden)

    Philipp Schuster

    2011-01-01

    Full Text Available In 1999, two independent groups identified plasmacytoid dendritic cells (PDC as major type I interferon- (IFN- producing cells in the blood. Since then, evidence is accumulating that PDC are a multifunctional cell population effectively coordinating innate and adaptive immune responses. This paper focuses on the role of different immune cells and their interactions in the surveillance of alpha herpes virus infections, summarizes current knowledge on PDC surface receptors and their role in direct cell-cell contacts, and develops a risk factor model for the clinical implications of herpes simplex and varicella zoster virus reactivation. Data from studies involving knockout mice and cell-depletion experiments as well as human studies converge into a “spider web”, in which the direct and indirect crosstalk between many cell populations tightly controls acute, latent, and recurrent alpha herpes virus infections. Notably, cells involved in innate immune regulations appear to shape adaptive immune responses more extensively than previously thought.

  3. Anti-CD25 monoclonal antibody Fc variants differentially impact regulatory T cells and immune homeostasis.

    Science.gov (United States)

    Huss, David J; Pellerin, Alex F; Collette, Brian P; Kannan, Arun K; Peng, Liaomin; Datta, Abhishek; Wipke, Brian T; Fontenot, Jason D

    2016-07-01

    Interleukin-2 (IL-2) is a critical regulator of immune homeostasis through its non-redundant role in regulatory T (Treg) cell biology. There is major interest in therapeutic modulation of the IL-2 pathway to promote immune activation in the context of tumour immunotherapy or to enhance immune suppression in the context of transplantation, autoimmunity and inflammatory diseases. Antibody-mediated targeting of the high-affinity IL-2 receptor α chain (IL-2Rα or CD25) offers a direct mechanism to target IL-2 biology and is being actively explored in the clinic. In mouse models, the rat anti-mouse CD25 clone PC61 has been used extensively to investigate the biology of IL-2 and Treg cells; however, there has been controversy and conflicting data on the exact in vivo mechanistic function of PC61. Engineering antibodies to alter Fc/Fc receptor interactions can significantly alter their in vivo function. In this study, we re-engineered the heavy chain constant region of an anti-CD25 monoclonal antibody to generate variants with highly divergent Fc effector function. Using these anti-CD25 Fc variants in multiple mouse models, we investigated the in vivo impact of CD25 blockade versus depletion of CD25(+) Treg cells on immune homeostasis. We report that immune homeostasis can be maintained during CD25 blockade but aberrant T-cell activation prevails when CD25(+) Treg cells are actively depleted. These results clarify the impact of PC61 on Treg cell biology and reveal an important distinction between CD25 blockade and depletion of CD25(+) Treg cells. These findings should inform therapeutic manipulation of the IL-2 pathway by targeting the high-affinity IL-2R. PMID:27012310

  4. In vivo imaging of Tregs providing immune privilege to the hematopoietic stem cell niche

    Science.gov (United States)

    Fujisaki, Joji; Wu, Juwell; Carlson, Alicia L.; Silberstein, Lev; Putheti, Prabhakar; Larocca, Rafael; Gao, Wenda; Saito, Toshiki I.; Celso, Cristina Lo; Tsuyuzaki, Hitoshi; Sato, Tatsuyuki; Côté, Daniel; Sykes, Megan; Strom, Terry B.; Scadden, David T.; Lin, Charles P.

    2013-01-01

    Stem cells reside in a specialized regulatory microenvironment or niche1,2, where they receive appropriate support for maintaining self-renewal and multi-lineage differentiation capacity1-3. The niche may also protect stem cells from environmental insults3 including cytotoxic chemotherapy and perhaps pathogenic immunity4. The testis, hair follicle, and placenta are all sites of residence for stem cells and are immune suppressive environments, called immune privileged (IP) sites, where multiple mechanisms conspire to prevent immune attack, even enabling prolonged survival of foreign allografts without immunosuppression (IS)4. We sought to determine if somatic stem cell niches more broadly are IP sites by examining the hematopoietic stem/progenitor cell (HSPC) niche1,2,5-7 in the bone marrow (BM), a site where immune reactivity exists8,9. We observed persistence of allo-HSPCs in non-irradiated recipients for 30 days without IS with the same survival frequency compared to syngeneic HSPCs. These HSPCs were lost after the depletion of FoxP3 regulatory T cells (Tregs). High resolution in vivo imaging over time demonstrated marked co-localization of HSPCs with Tregs that accumulated on the endosteal surface in the calvarial and trabecular BM. Tregs appear to participate in creating a localized zone where HSPCs reside and where Tregs are necessary for allo-HSPC persistence. In addition to processes supporting stem cell function, the niche will provide a relative sanctuary from immune attack. PMID:21654805

  5. Effective fiber hypertrophy in satellite cell-depleted skeletal muscle

    OpenAIRE

    McCarthy, John J.; Mula, Jyothi; Miyazaki, Mitsunori; Erfani, Rod; Garrison, Kelcye; Farooqui, Amreen B.; Srikuea, Ratchakrit; Lawson, Benjamin A.; Grimes, Barry; Keller, Charles; Zant, Gary Van; Campbell, Kenneth S.; Esser, Karyn A.; Dupont-Versteegden, Esther E.; Peterson, Charlotte A.

    2011-01-01

    An important unresolved question in skeletal muscle plasticity is whether satellite cells are necessary for muscle fiber hypertrophy. To address this issue, a novel mouse strain (Pax7-DTA) was created which enabled the conditional ablation of >90% of satellite cells in mature skeletal muscle following tamoxifen administration. To test the hypothesis that satellite cells are necessary for skeletal muscle hypertrophy, the plantaris muscle of adult Pax7-DTA mice was subjected to mechanical overl...

  6. Cumulative Doses of T-Cell Depleting Antibody and Cancer Risk after Kidney Transplantation.

    Directory of Open Access Journals (Sweden)

    Jenny H C Chen

    Full Text Available T-cell depleting antibody is associated with an increased risk of cancer after kidney transplantation, but a dose-dependent relationship has not been established. This study aimed to determine the association between cumulative doses of T-cell depleting antibody and the risk of cancer after kidney transplantation. Using data from the Australian and New Zealand Dialysis and Transplant Registry between 1997-2012, we assessed the risk of incident cancer and cumulative doses of T-cell depleting antibody using adjusted Cox regression models. Of the 503 kidney transplant recipients with 2835 person-years of follow-up, 276 (55%, 209 (41% and 18 (4% patients received T-cell depleting antibody for induction, rejection or induction and rejection respectively. The overall cancer incidence rate was 1,118 cancers per 100,000 patient-years, with 975, 1093 and 1377 cancers per 100,000 patient-years among those who had received 1-5 doses, 6-10 doses and >10 doses, respectively. There was no association between cumulative doses of T cell depleting antibody and risk of incident cancer (1-5: referent, 6-10: adjusted hazard ratio (HR 1.19, 95%CI 0.48-2.95, >10: HR 1.42, 95%CI 0.50-4.02, p = 0.801. This lack of association is contradictory to our hypothesis and is likely attributed to the low event rates resulting in insufficient power to detect significant differences.

  7. Cancer Stem Cell-Secreted Macrophage Migration Inhibitory Factor Stimulates Myeloid Derived Suppressor Cell Function and Facilitates Glioblastoma Immune Evasion.

    Science.gov (United States)

    Otvos, Balint; Silver, Daniel J; Mulkearns-Hubert, Erin E; Alvarado, Alvaro G; Turaga, Soumya M; Sorensen, Mia D; Rayman, Patricia; Flavahan, William A; Hale, James S; Stoltz, Kevin; Sinyuk, Maksim; Wu, Qiulian; Jarrar, Awad; Kim, Sung-Hak; Fox, Paul L; Nakano, Ichiro; Rich, Jeremy N; Ransohoff, Richard M; Finke, James; Kristensen, Bjarne W; Vogelbaum, Michael A; Lathia, Justin D

    2016-08-01

    Shifting the balance away from tumor-mediated immune suppression toward tumor immune rejection is the conceptual foundation for a variety of immunotherapy efforts currently being tested. These efforts largely focus on activating antitumor immune responses but are confounded by multiple immune cell populations, including myeloid-derived suppressor cells (MDSCs), which serve to suppress immune system function. We have identified immune-suppressive MDSCs in the brains of GBM patients and found that they were in close proximity to self-renewing cancer stem cells (CSCs). MDSCs were selectively depleted using 5-flurouracil (5-FU) in a low-dose administration paradigm, which resulted in prolonged survival in a syngeneic mouse model of glioma. In coculture studies, patient-derived CSCs but not nonstem tumor cells selectively drove MDSC-mediated immune suppression. A cytokine screen revealed that CSCs secreted multiple factors that promoted this activity, including macrophage migration inhibitory factor (MIF), which was produced at high levels by CSCs. Addition of MIF increased production of the immune-suppressive enzyme arginase-1 in MDSCs in a CXCR2-dependent manner, whereas blocking MIF reduced arginase-1 production. Similarly to 5-FU, targeting tumor-derived MIF conferred a survival advantage to tumor-bearing animals and increased the cytotoxic T cell response within the tumor. Importantly, tumor cell proliferation, survival, and self-renewal were not impacted by MIF reduction, demonstrating that MIF is primarily an indirect promoter of GBM progression, working to suppress immune rejection by activating and protecting immune suppressive MDSCs within the GBM tumor microenvironment. Stem Cells 2016;34:2026-2039. PMID:27145382

  8. Proinflammatory GM-CSF-producing B cells in multiple sclerosis and B cell depletion therapy.

    Science.gov (United States)

    Li, Rui; Rezk, Ayman; Miyazaki, Yusei; Hilgenberg, Ellen; Touil, Hanane; Shen, Ping; Moore, Craig S; Michel, Laure; Althekair, Faisal; Rajasekharan, Sathy; Gommerman, Jennifer L; Prat, Alexandre; Fillatreau, Simon; Bar-Or, Amit

    2015-10-21

    B cells are not limited to producing protective antibodies; they also perform additional functions relevant to both health and disease. However, the relative contribution of functionally distinct B cell subsets in human disease, the signals that regulate the balance between such subsets, and which of these subsets underlie the benefits of B cell depletion therapy (BCDT) are only partially elucidated. We describe a proinflammatory, granulocyte macrophage-colony stimulating factor (GM-CSF)-expressing human memory B cell subset that is increased in frequency and more readily induced in multiple sclerosis (MS) patients compared to healthy controls. In vitro, GM-CSF-expressing B cells efficiently activated myeloid cells in a GM-CSF-dependent manner, and in vivo, BCDT resulted in a GM-CSF-dependent decrease in proinflammatory myeloid responses of MS patients. A signal transducer and activator of transcription 5 (STAT5)- and STAT6-dependent mechanism was required for B cell GM-CSF production and reciprocally regulated the generation of regulatory IL-10-expressing B cells. STAT5/6 signaling was enhanced in B cells of untreated MS patients compared with healthy controls, and B cells reemerging in patients after BCDT normalized their STAT5/6 signaling as well as their GM-CSF/IL-10 cytokine secretion ratios. The diminished proinflammatory myeloid cell responses observed after BCDT persisted even as new B cells reconstituted. These data implicate a proinflammatory B cell/myeloid cell axis in disease and underscore the rationale for selective targeting of distinct B cell populations in MS and other human autoimmune diseases. PMID:26491076

  9. Are Platelets Cells? And if Yes, Are They Immune Cells?

    Directory of Open Access Journals (Sweden)

    Fabrice eCOGNASSE

    2015-02-01

    Full Text Available Small fragments circulating in the blood were formally identified by the end of the 19th century, and it was suggested that they assisted coagulation via interactions with vessel endothelia. Wright, at the beginning of the 20th century, identified their bone-marrow origin. For long, platelets have been considered sticky assistants of hemostasis and pollutants of blood or tissue samples; they were just cell fragments. As such however, they were acknowledged as immunizing (to specific HPA and HLA markers: the platelet’s dark face. The enlightened face showed that besides hemostasis, platelets contained factors involved in healing. As early as the 1930s, platelets entered the arsenal of medicines; were transfused, and were soon manipulated to become a kind of glue to repair damaged tissues. Some gladly categorized platelets as cells but they were certainly not fully licensed as such for cell physiologists. Actually, platelets possess almost every characteristic of cells, apart from being capable of organizing their genes: they have neither a nucleus nor genes. This view prevailed until it became evident that platelets play a role in homeostasis and interact with cells other than with vascular endothelial cells; then began the era of physiological and also pathological inflammation. Platelets have now entered the field of immunity as inflammatory cells. Does assistance to immune cells itself suffice to license a cell as an immune cell? Platelets prove capable of sensing different types of signals and organizing an appropriate response. Many cells can do that. However, platelets can use a complete signalosome (apart from the last transcription step, though it is likely that this step can be circumvented by retrotranscribing RNA messages. The question has also arisen as to whether platelets can present antigen via their abundantly expressed MHC class I molecules. In combination, these properties argue in favor of allowing platelets the title of

  10. Depletion of the AP-1 repressor JDP2 induces cell death similar to apoptosis

    DEFF Research Database (Denmark)

    Lerdrup, Mads; Holmberg, Christian Henrik; Dietrich, Nikolaj;

    2005-01-01

    depletion of JDP2 resulted in p53-independent cell death that resembles apoptosis and was evident at 72 h. The death mechanism was caspase dependent as the cells could be rescued by treatment with caspase inhibitor zVAD. Our studies suggest that JDP2 functions as a general survival protein, not only...

  11. Generation of Immune Inhibitory Dendritic Cells and

    Directory of Open Access Journals (Sweden)

    Abediankenari Saeid

    2009-03-01

    Full Text Available Variety of positive as well as negative regulatory signals are provided by antigen presenting cell in particular by dendritic cells. In this research, we studied the capacity of dendritic cells to expand antigen-specific T regulatory cells.We also investigated the role of TGF-beta in induction inhibitory functions of dendritic cells in mixed leukocyte reactions.Dendritic cells were generated from blood CD14+ monocytes with granulocyte-Monocyte colony stimulating factor and interleukin-4 with or without TGF-beta (TGF-β-GM-DC or GM-DC. CD4+ T cell were isolated to assess lymphocyte proliferation by lymphocyte transformation test assay and the ratio of CD4+FOXp3+ CD25+ T cells were determined by fluorescene-activated cell sorter. T cell proliferation responses in GM-DC showed a significance antigen-specific proliferative response comparing with TGFβ-GM -DC. T Cell proliferation was inhibited in co-culture system containing DC-treated TGF-β. It can be suggested that the expsansion of T regulatory by TGF-β-GM-DC provides a means for antigen specific control of unwanted immune reactions.

  12. CD4+ T cells mediate mucosal and systemic immune responses to experimental hookworm infection

    OpenAIRE

    DONDJI, B.; Sun, T.; BUNGIRO, R. D.; VERMEIRE, J. J.; HARRISON, L. M.; BIFULCO, C.; Cappello, M

    2010-01-01

    Hookworm infection is associated with anaemia and malnutrition in many resource-limited countries. Ancylostoma hookworms have previously been shown to modulate host cellular immune responses through multiple mechanisms, including reduced mitogen-mediated lymphocyte proliferation, impaired antigen presentation/processing, and relative reductions in CD4+ T cells in the spleen and mesenteric lymph nodes. Syrian hamsters were depleted of CD4+ for up to 9 days following intraperitoneal injection (...

  13. Are Platelets Cells? And if Yes, are They Immune Cells?

    Science.gov (United States)

    Garraud, Olivier; Cognasse, Fabrice

    2015-01-01

    Small fragments circulating in the blood were formally identified by the end of the nineteenth century, and it was suggested that they assisted coagulation via interactions with vessel endothelia. Wright, at the beginning of the twentieth century, identified their bone-marrow origin. For long, platelets have been considered sticky assistants of hemostasis and pollutants of blood or tissue samples; they were just cell fragments. As such, however, they were acknowledged as immunizing (to specific HPA and HLA markers): the platelet’s dark face. The enlightened face showed that besides hemostasis, platelets contained factors involved in healing. As early as 1930s, platelets entered the arsenal of medicines were transfused, and were soon manipulated to become a kind of glue to repair damaged tissues. Some gladly categorized platelets as cells but they were certainly not fully licensed as such for cell physiologists. Actually, platelets possess almost every characteristic of cells, apart from being capable of organizing their genes: they have neither a nucleus nor genes. This view prevailed until it became evident that platelets play a role in homeostasis and interact with cells other than with vascular endothelial cells; then began the era of physiological and also pathological inflammation. Platelets have now entered the field of immunity as inflammatory cells. Does assistance to immune cells itself suffice to license a cell as an “immune cell”? Platelets prove capable of sensing different types of signals and organizing an appropriate response. Many cells can do that. However, platelets can use a complete signalosome (apart from the last transcription step, though it is likely that this step can be circumvented by retrotranscribing RNA messages). The question has also arisen as to whether platelets can present antigen via their abundantly expressed MHC class I molecules. In combination, these properties argue in favor of allowing platelets the title of immune

  14. Age-related mitochondrial DNA depletion and the impact on pancreatic Beta cell function.

    Directory of Open Access Journals (Sweden)

    Donna L Nile

    Full Text Available Type 2 diabetes is characterised by an age-related decline in insulin secretion. We previously identified a 50% age-related decline in mitochondrial DNA (mtDNA copy number in isolated human islets. The purpose of this study was to mimic this degree of mtDNA depletion in MIN6 cells to determine whether there is a direct impact on insulin secretion. Transcriptional silencing of mitochondrial transcription factor A, TFAM, decreased mtDNA levels by 40% in MIN6 cells. This level of mtDNA depletion significantly decreased mtDNA gene transcription and translation, resulting in reduced mitochondrial respiratory capacity and ATP production. Glucose-stimulated insulin secretion was impaired following partial mtDNA depletion, but was normalised following treatment with glibenclamide. This confirms that the deficit in the insulin secretory pathway precedes K+ channel closure, indicating that the impact of mtDNA depletion is at the level of mitochondrial respiration. In conclusion, partial mtDNA depletion to a degree comparable to that seen in aged human islets impaired mitochondrial function and directly decreased insulin secretion. Using our model of partial mtDNA depletion following targeted gene silencing of TFAM, we have managed to mimic the degree of mtDNA depletion observed in aged human islets, and have shown how this correlates with impaired insulin secretion. We therefore predict that the age-related mtDNA depletion in human islets is not simply a biomarker of the aging process, but will contribute to the age-related risk of type 2 diabetes.

  15. Metabolism of stromal and immune cells in health and disease

    OpenAIRE

    Ghesquière, Bart; Wong, Brian W.; Kuchnio, Anna; Carmeliet, Peter

    2014-01-01

    Cancer cells have been at the centre of cell metabolism research, but the metabolism of stromal and immune cells has received less attention. Nonetheless, these cells influence the progression of malignant, inflammatory and metabolic disorders. Here we discuss the metabolic adaptations of stromal and immune cells in health and disease, and highlight how metabolism determines their differentiation and function.

  16. Satellite cell depletion prevents fiber hypertrophy in skeletal muscle.

    Science.gov (United States)

    Egner, Ingrid M; Bruusgaard, Jo C; Gundersen, Kristian

    2016-08-15

    The largest mammalian cells are the muscle fibers, and they have multiple nuclei to support their large cytoplasmic volumes. During hypertrophic growth, new myonuclei are recruited from satellite stem cells into the fiber syncytia, but it was recently suggested that such recruitment is not obligatory: overload hypertrophy after synergist ablation of the plantaris muscle appeared normal in transgenic mice in which most of the satellite cells were abolished. When we essentially repeated these experiments analyzing the muscles by immunohistochemistry and in vivo and ex vivo imaging, we found that overload hypertrophy was prevented in the satellite cell-deficient mice, in both the plantaris and the extensor digitorum longus muscles. We attribute the previous findings to a reliance on muscle mass as a proxy for fiber hypertrophy, and to the inclusion of a significant number of regenerating fibers in the analysis. We discuss that there is currently no model in which functional, sustainable hypertrophy has been unequivocally demonstrated in the absence of satellite cells; an exception is re-growth, which can occur using previously recruited myonuclei without addition of new myonuclei. PMID:27531949

  17. Inhibition of autophagy augments apoptosis in human oral squamous cell carcinoma under nutrient depletion.

    Science.gov (United States)

    Jiang, Li-Cheng; Xin, Zhi-Yuan; Deborah, Baremberg; Zhang, Jun-Sheng; Yuan, Dao-Ying; Xu, Kai; Liu, Xian-Bin; Jiang, Hu-Quan; Fan, Qing-Chun; Zhang, Bin; Li, Ke-Yi

    2015-05-01

    There has been little research conducted regarding autophagy in oral squamous cell carcinoma (OSCC). Given the prevalence of oral cancers which are OSCC and the severe side effects of current treatments, there is a pressing need to develop effective alternative therapies. In this study, we have endeavored to explore the biological characteristics of oral squamous cell carcinoma cell line KB cells, in particular with regard to the role played by autophagy in their survival. Autophagy was activated by nutrient depletion via culturing cells in Earle's balanced salts (EBSS) and was measured via indices relating to Beclin 1, microtubule-associated protein light chain 3 (MAPLC3, LC3), p62, and Green fluorescent protein-light chain 3 plasmid transfection (GFP-LC3). Cell death and apoptosis induced by nutrient depletion was measured using both MTT assay and flow cytometry (FCM). Compared to initial levels at 0 h, Beclin 1 density in EBSS-treated cells was found to have increased at 6, 12, and 18 h in a time-dependent manner and was found to have subsequently declined at 24 and 48 h. p62 levels, LC3-II/LC3-I ratio, and GFP-LC3 levels increased at 6, 12, 18, 24, and 48 h in a time-dependent manner. 3-methyladenine (3-MA) was found to inhibit autophagy and the expression of Beclin 1 and significantly enhanced nutrient depletion-induced apoptosis and death. We concluded that nutrient depletion enhances OSCC cell autophagy in time-course patterns and that the inhibition of autophagy augments apoptosis in OSCC cells. We also deduced that Beclin 1 takes part in the development and progression of autophagy, potentially playing an important role in the crosstalk between apoptosis and autophagy in OSCC cells. These findings suggest that nutrient depletion may be an effective way to explore autophagy and that autophagy inhibitors should be investigated as a potential novel agent for the adjuvant treatment of human OSCC.

  18. Competition for IL-2 between regulatory and effector T cells to chisel immune responses

    Directory of Open Access Journals (Sweden)

    Thomas eHöfer

    2012-09-01

    Full Text Available In this review we discuss how the competition for cytokines between different cells of the immune system can shape the system wide immune response. We focus on interleukin-2 (IL-2 secretion by activated effector T cells (Teff and on the competition for IL-2 consumption between Teff and regulatory T cells (Treg. We discuss the evidence for the mechanism in which the depletion of IL-2 by Treg cells would be sufficient to suppress an autoimmune response, yet not strong enough to prevent an immune response. We present quantitative estimations and summarize our modeling effort to show that the tug-of-war between Treg and Teff cells for IL-2 molecules can be won by Treg cells in the case of weak activation of Teff leading to the suppression of the immune response. Or, for strongly activated Teff cells, it can be won by Teff cells bringing about the activation of the whole adaptive immune system. Finally, we discuss some recent applications attempting to achieve clinical effects through the modulation of IL-2 consumption by Treg compartment.

  19. CD4+ and CD8+ T cells can act separately in tumour rejection after immunization with murine pneumotropic virus chimeric Her2/neu virus-like particles.

    Directory of Open Access Journals (Sweden)

    Kalle Andreasson

    Full Text Available BACKGROUND: Immunization with murine pneumotropic virus virus-like particles carrying Her2/neu (Her2MPtVLPs prevents tumour outgrowth in mice when given prophylactically, and therapeutically if combined with the adjuvant CpG. We investigated which components of the immune system are involved in tumour rejection, and whether long-term immunological memory can be obtained. METHODOLOGY AND RESULTS: During the effector phase in BALB/c mice, only depletion of CD4+ and CD8+ in combination, with or without NK cells, completely abrogated tumour protection. Depletion of single CD4+, CD8+ or NK cell populations only had minor effects. During the immunization/induction phase, combined depletion of CD4+ and CD8+ cells abolished protection, while depletion of each individual subset had no or negligible effect. When tumour rejection was studied in knock-out mice with a C57Bl/6 background, protection was lost in CD4-/-CD8-/- and CD4-/-, but not in CD8-/- mice. In contrast, when normal C57Bl/6 mice were depleted of different cell types, protection was lost irrespective of whether only CD4+, only CD8+, or CD4+ and CD8+ cells in combination were eradicated. No anti-Her2/neu antibodies were detected but a Her2/neu-specific IFNgamma response was seen. Studies of long-term memory showed that BALB/c mice could be protected against tumour development when immunized together with CpG as long as ten weeks before challenge. CONCLUSION: Her2MPtVLP immunization is efficient in stimulating several compartments of the immune system, and induces an efficient immune response including long-term memory. In addition, when depleting mice of isolated cellular compartments, tumour protection is not as efficiently abolished as when depleting several immune compartments together.

  20. Interaction of natural killer cells with neutrophils exerts a significant antitumor immunity in hematopoietic stem cell transplantation recipients.

    Science.gov (United States)

    Ueda, Ryosuke; Narumi, Kenta; Hashimoto, Hisayoshi; Miyakawa, Reina; Okusaka, Takuji; Aoki, Kazunori

    2016-01-01

    Autologous hematopoietic stem cell transplantation (HSCT) can induce a strong antitumor immunity by homeostatic proliferation (HP) of T cells and suppression of regulatory T cells following preconditioning-induced lymphopenia. However, the role of innate immunity including natural killer (NK) cells is still not understood. Here, first, we examined whether NK cells exert an antitumor effect after syngeneic HSCT in a murine colon cancer model. Flow cytometry showed that NK cells as well as T cells rapidly proliferated after HSCT, and the frequency of mature NK cells was increased in tumor during HP. Furthermore, NK cells undergoing HP were highly activated, which contributed to substantial tumor suppression. Then, we found that a large number of neutrophils accumulated in tumor early after syngeneic HSCT. It was recently reported that neutrophil-derived mediators modulate NK cell effector functions, and so we examined whether the neutrophils infiltrated in tumor are associated with NK cell-mediated antitumor effect. The depletion of neutrophils significantly impaired an activation of NK cells in tumor and increased the fraction of proliferative NK cells accompanied by a decrease in NK cell survival. The results suggested that neutrophils in tumor prevent NK cells from activation-induced cell death during HP, thus leading to a significant antitumor effect by NK cells. This study revealed a novel aspect of antitumor immunity induced by HSCT and may contribute to the development of an effective therapeutic strategy for cancer using HSCT.

  1. Cell death by pyroptosis drives CD4 T-cell depletion in HIV-1 infection

    Science.gov (United States)

    Doitsh, Gilad; Galloway, Nicole L. K.; Geng, Xin; Yang, Zhiyuan; Monroe, Kathryn M.; Zepeda, Orlando; Hunt, Peter W.; Hatano, Hiroyu; Sowinski, Stefanie; Muñoz-Arias, Isa; Greene, Warner C.

    2014-01-01

    The pathway causing CD4 T-cell death in HIV-infected hosts remains poorly understood although apoptosis has been proposed as a key mechanism. We now show that caspase-3-mediated apoptosis accounts for the death of only a small fraction of CD4 T cells corresponding to those that are both activated and productively infected. The remaining over 95% of quiescent lymphoid CD4 T cells die by caspase-1-mediated pyroptosis triggered by abortive viral infection. Pyroptosis corresponds to an intensely inflammatory form of programmed cell death in which cytoplasmic contents and pro-inflammatory cytokines, including IL-1β, are released. This death pathway thus links the two signature events in HIV infection--CD4 T-cell depletion and chronic inflammation--and creates a pathogenic vicious cycle in which dying CD4 T cells release inflammatory signals that attract more cells to die. This cycle can be broken by caspase 1 inhibitors shown to be safe in humans, raising the possibility of a new class of `anti-AIDS' therapeutics targeting the host rather than the virus.

  2. Lignin depletion enhances the digestibility of cellulose in cultured xylem cells.

    Directory of Open Access Journals (Sweden)

    Catherine I Lacayo

    Full Text Available Plant lignocellulose constitutes an abundant and sustainable source of polysaccharides that can be converted into biofuels. However, the enzymatic digestion of native plant cell walls is inefficient, presenting a considerable barrier to cost-effective biofuel production. In addition to the insolubility of cellulose and hemicellulose, the tight association of lignin with these polysaccharides intensifies the problem of cell wall recalcitrance. To determine the extent to which lignin influences the enzymatic digestion of cellulose, specifically in secondary walls that contain the majority of cellulose and lignin in plants, we used a model system consisting of cultured xylem cells from Zinniaelegans. Rather than using purified cell wall substrates or plant tissue, we have applied this system to study cell wall degradation because it predominantly consists of homogeneous populations of single cells exhibiting large deposits of lignocellulose. We depleted lignin in these cells by treating with an oxidative chemical or by inhibiting lignin biosynthesis, and then examined the resulting cellulose digestibility and accessibility using a fluorescent cellulose-binding probe. Following cellulase digestion, we measured a significant decrease in relative cellulose content in lignin-depleted cells, whereas cells with intact lignin remained essentially unaltered. We also observed a significant increase in probe binding after lignin depletion, indicating that decreased lignin levels improve cellulose accessibility. These results indicate that lignin depletion considerably enhances the digestibility of cellulose in the cell wall by increasing the susceptibility of cellulose to enzymatic attack. Although other wall components are likely to contribute, our quantitative study exploits cultured Zinnia xylem cells to demonstrate the dominant influence of lignin on the enzymatic digestion of the cell wall. This system is simple enough for quantitative image analysis

  3. Depletion of CD8+ cells does not affect the lifespan of productively infected cells during pathogenic sivmac239 infection of rhesus macaques

    Energy Technology Data Exchange (ETDEWEB)

    Shudo, Emi [Los Alamos National Laboratory; Ribeiro, Ruy M [Los Alamos National Laboratory; Perelson, Alan S [Los Alamos National Laboratory

    2008-01-01

    While CD8+ T cell responses are clearly important in anti-viral immunity during HIV/SIV infection, the mechanisms by which CD8+ T cells induce this effect remain poorly understood, as emphasized by the failure of the Merck adenovirus-based, cytotoxic T lymphocyte (CTL)-inducing AIDS vaccine in a large phase IIb clinical trial. In this study, we measured the in vivo effect of CD8+ lymphocytes on the lifespan of productively infected cells during chronic SIVmac239 infection of rhesus macaques by treating two groups of animals (i.e., CD8+ lymphocyte-depleted or controls) with antiretroviral therapy (PMPA and FTC). The lifespan of productively infected cells was calculated based on the slope of the decline of SIV plasma viremia using a well-accepted mathematical model. We found that, in both early (i.e., day 57 post-inoculation) and late (i.e., day 177 post-inoculation) chronic SIV infection, depletion of CD8+ lymphocytes did not result in an increased lifespan of productively infected cells in vivo. This result indicates that direct killing of cells producing virus is unlikely to be a major mechanism underlying the anti-viral effect of CD8+ T cells during SIV infection. These results have profound implications for the development of AIDS vaccines.

  4. In Vivo Depletion of T Lymphocytes.

    Science.gov (United States)

    Laky, Karen; Kruisbeek, Ada M

    2016-01-01

    In vivo depletion of T lymphocytes is a means of studying the role of specific T cell populations during defined phases of in vivo immune responses. In this unit, a protocol is provided for injecting monoclonal antibodies (mAbs) into wild-type adult mice. Depletion of the appropriate subset of cells is verified by flow cytometry analysis of lymph node and spleen cell suspensions in pilot experiments. Once conditions have been established, depleted mice can be used to study the impact of T cell subsets on a variety of in vivo immune responses. The depleted condition may be maintained by repeated injections of the monoclonal antibody, or reversed by normal thymopoiesis following discontinuation of antibody administration. PMID:27038463

  5. M cell-depletion blocks oral prion disease pathogenesis

    OpenAIRE

    Donaldson, D S; Kobayashi, A; Ohno, H.; Yagita, H; Williams, I R; Mabbott, N A

    2012-01-01

    Many prion diseases are orally acquired. Our data show that after oral exposure, early prion replication upon follicular dendritic cells (FDC) in Peyer's patches is obligatory for the efficient spread of disease to the brain (termed neuroinvasion). For prions to replicate on FDC within Peyer's patches after ingestion of a contaminated meal, they must first cross the gut epithelium. However, the mechanism through which prions are conveyed into Peyer's patches is uncertain. Within the follicle-...

  6. Essential oil of clove (Eugenia caryophyllata) augments the humoral immune response but decreases cell mediated immunity.

    Science.gov (United States)

    Halder, Sumita; Mehta, Ashish K; Mediratta, Pramod K; Sharma, Krishna K

    2011-08-01

    The present study was undertaken to explore the effect of the essential oil isolated from the buds of Eugenia caryophyllata on some immunological parameters. Humoral immunity was assessed by measuring the hemagglutination titre to sheep red blood cells and delayed type hypersensitivity was assessed by measuring foot pad thickness. Clove oil administration produced a significant increase in the primary as well as secondary humoral immune response. In addition, it also produced a significant decrease in foot pad thickness compared with the control group. Thus, these results suggest that clove oil can modulate the immune response by augmenting humoral immunity and decreasing cell mediated immunity. PMID:21796701

  7. Estimation of immune cell densities in immune cell conglomerates: an approach for high-throughput quantification.

    Directory of Open Access Journals (Sweden)

    Niels Halama

    Full Text Available BACKGROUND: Determining the correct number of positive immune cells in immunohistological sections of colorectal cancer and other tumor entities is emerging as an important clinical predictor and therapy selector for an individual patient. This task is usually obstructed by cell conglomerates of various sizes. We here show that at least in colorectal cancer the inclusion of immune cell conglomerates is indispensable for estimating reliable patient cell counts. Integrating virtual microscopy and image processing principally allows the high-throughput evaluation of complete tissue slides. METHODOLOGY/PRINCIPAL FINDINGS: For such large-scale systems we demonstrate a robust quantitative image processing algorithm for the reproducible quantification of cell conglomerates on CD3 positive T cells in colorectal cancer. While isolated cells (28 to 80 microm(2 are counted directly, the number of cells contained in a conglomerate is estimated by dividing the area of the conglomerate in thin tissues sections (< or =6 microm by the median area covered by an isolated T cell which we determined as 58 microm(2. We applied our algorithm to large numbers of CD3 positive T cell conglomerates and compared the results to cell counts obtained manually by two independent observers. While especially for high cell counts, the manual counting showed a deviation of up to 400 cells/mm(2 (41% variation, algorithm-determined T cell numbers generally lay in between the manually observed cell numbers but with perfect reproducibility. CONCLUSION: In summary, we recommend our approach as an objective and robust strategy for quantifying immune cell densities in immunohistological sections which can be directly implemented into automated full slide image processing systems.

  8. Mast Cell and Immune Inhibitory Receptors

    Institute of Scientific and Technical Information of China (English)

    Lixin Li; Zhengbin Yao

    2004-01-01

    Modulation by balancing activating and inhibitory receptors constitutes an important mechanism for regulating immune responses. Cells that are activated following ligation of receptors bearing immunoreceptor tyrosine-based activation motifs (ITAMs) can be negatively regulated by other receptors bearing immunoreceptor tyrosine-based inhibition motifs (ITIMs). Human mast cells (MCs) are the major effector cells of type I hypersensitivity and important participants in a number of disease processes. Antigen-mediated aggregation of IgE bound to its high-affinity receptor on MCs initiates a complex series of biochemical events leading to MC activation. With great detailed description and analysis of several inhibitory receptors on human MCs, a central paradigm of negative regulation of human MC activation by these receptors has emerged. Cellular & Molecular Immunology. 2004;1(6):408-415.

  9. Respiratory epithelial cells orchestrate pulmonary innate immunity.

    Science.gov (United States)

    Whitsett, Jeffrey A; Alenghat, Theresa

    2015-01-01

    The epithelial surfaces of the lungs are in direct contact with the environment and are subjected to dynamic physical forces as airway tubes and alveoli are stretched and compressed during ventilation. Mucociliary clearance in conducting airways, reduction of surface tension in the alveoli, and maintenance of near sterility have been accommodated by the evolution of a multi-tiered innate host-defense system. The biophysical nature of pulmonary host defenses are integrated with the ability of respiratory epithelial cells to respond to and 'instruct' the professional immune system to protect the lungs from infection and injury. PMID:25521682

  10. Regulation of the adaptive immune system by innate lymphoid cells

    OpenAIRE

    Hepworth, Matthew R.; Sonnenberg, Gregory F.

    2014-01-01

    Innate lymphoid cells (ILCs) are a group of lymphocytes that promote rapid cytokine-dependent innate immunity, inflammation and tissue repair. In addition, a growing body of evidence suggests ILCs can influence adaptive immune cell responses. During fetal development a subset of ILCs orchestrate the generation and maturation of secondary lymphoid tissues. Following birth, ILCs continue to modulate adaptive immune cell responses indirectly through interactions with stromal cells in lymphoid ti...

  11. Ex vivo cytosolic delivery of functional macromolecules to immune cells.

    Directory of Open Access Journals (Sweden)

    Armon Sharei

    Full Text Available Intracellular delivery of biomolecules, such as proteins and siRNAs, into primary immune cells, especially resting lymphocytes, is a challenge. Here we describe the design and testing of microfluidic intracellular delivery systems that cause temporary membrane disruption by rapid mechanical deformation of human and mouse immune cells. Dextran, antibody and siRNA delivery performance is measured in multiple immune cell types and the approach's potential to engineer cell function is demonstrated in HIV infection studies.

  12. CD3+CD8+CD161high Tc17 cells are depleted in HIV-infection.

    Science.gov (United States)

    Gaardbo, Julie Christine; Hartling, Hans Jakob; Thorsteinsson, Kristina; Ullum, Henrik; Nielsen, Susanne Dam

    2013-02-20

    CD8 Tc17 cells with pro-inflammatory properties have only recently been acknowledged, and Tc17 cells in HIV-infection are not described. CD3CD8CD161 Tc17 cells and the production of interleukin (IL)-17 were examined in untreated and treated HIV-infected patients, HIV-hepatitis C virus co-infected patients, and healthy controls. Depletion of CD3CD8CD161 Tc17 cells and diminished production of IL-17 in HIV-infected patients were found. The level of Tc17 cells was associated with the CD4 cell count in treated patients. PMID:23135168

  13. B Cell Depletion: Rituximab in Glomerular Disease and Transplantation

    Directory of Open Access Journals (Sweden)

    S. Marinaki

    2013-12-01

    Full Text Available B cells play a central role in the pathogenesis of many autoimmune diseases. Selective targeting can be achieved with the use of the monoclonal antibody rituximab. In addition to being a drug for non-Hodgkin's lymphoma, rituximab is also an FDA-approved treatment for refractory rheumatoid arthritis and, since recently, ANCA vasculitis. It has shown efficacy in many autoimmune diseases. This review will discuss current evidence and the rationale of the use of rituximab in glomerular diseases, including randomized controlled trials. The focus will be on the use of rituximab in idiopathic membranous nephropathy, systemic lupus erythematosus and ANCA-associated vasculitis. The emerging role of rituximab in renal transplantation, where it seems to be important for the desensitization protocols for highly sensitized patients as well as for the preconditioning of ABO-incompatible recipients and the treatment of antibody-mediated rejection, will also be addressed.

  14. Zika Virus Depletes Neural Progenitors in Human Cerebral Organoids through Activation of the Innate Immune Receptor TLR3.

    Science.gov (United States)

    Dang, Jason; Tiwari, Shashi Kant; Lichinchi, Gianluigi; Qin, Yue; Patil, Veena S; Eroshkin, Alexey M; Rana, Tariq M

    2016-08-01

    Emerging evidence from the current outbreak of Zika virus (ZIKV) indicates a strong causal link between Zika and microcephaly. To investigate how ZIKV infection leads to microcephaly, we used human embryonic stem cell-derived cerebral organoids to recapitulate early stage, first trimester fetal brain development. Here we show that a prototype strain of ZIKV, MR766, efficiently infects organoids and causes a decrease in overall organoid size that correlates with the kinetics of viral copy number. The innate immune receptor Toll-like-Receptor 3 (TLR3) was upregulated after ZIKV infection of human organoids and mouse neurospheres and TLR3 inhibition reduced the phenotypic effects of ZIKV infection. Pathway analysis of gene expression changes during TLR3 activation highlighted 41 genes also related to neuronal development, suggesting a mechanistic connection to disrupted neurogenesis. Together, therefore, our findings identify a link between ZIKV-mediated TLR3 activation, perturbed cell fate, and a reduction in organoid volume reminiscent of microcephaly.

  15. CENPA overexpression promotes genome instability in pRb-depleted human cells

    Directory of Open Access Journals (Sweden)

    Lentini Laura

    2009-12-01

    Full Text Available Abstract Background Aneuploidy is a hallmark of most human cancers that arises as a consequence of chromosomal instability and it is frequently associated with centrosome amplification. Functional inactivation of the Retinoblastoma protein (pRb has been indicated as a cause promoting chromosomal instability as well centrosome amplification. However, the underlying molecular mechanism still remains to be clarified. Results Here we show that pRb depletion both in wild type and p53 knockout HCT116 cells was associated with the presence of multipolar spindles, anaphase bridges, lagging chromosomes and micronuclei harbouring whole chromosomes. In addition aneuploidy caused by pRb acute loss was not affected by p53 loss. Quantitative real-time RT-PCR showed that pRB depletion altered expression of genes involved in centrosome duplication, kinetochore assembly and in the Spindle Assembly Checkpoint (SAC. However, despite MAD2 up-regulation pRb-depleted cells seemed to have a functional SAC since they arrested in mitosis after treatments with mitotic poisons. Moreover pRb-depleted HCT116 cells showed BRCA1 overexpression that seemed responsible for MAD2 up-regulation. Post-transcriptional silencing of CENPA by RNA interference, resulting in CENP-A protein levels similar to those present in control cells greatly reduced aneuploid cell numbers in pRb-depleted cells. Conclusion Altogether our findings indicate a novel aspect of pRb acute loss that promotes aneuploidy mainly by inducing CENPA overexpression that in turn might induce micronuclei by affecting the correct attachment of spindle microtubules to kinetochores.

  16. Deciphering dendritic cell heterogenity in immunity

    Directory of Open Access Journals (Sweden)

    Michaël eChopin

    2012-02-01

    Full Text Available Dendritic cells (DCs are specialized antigen presenting cells that are exquisitely adapted to sense pathogens and induce the development of adaptive immune responses. They form a complex network of phenotypically and functionally distinct subsets. Within this network, individual DC subsets display highly specific roles in local immunosurveillance, migration and antigen presentation. This division of labor amongst DCs offers great potential to tune the immune response by harnessing subset-specific attributes of DCs in the clinical setting. Until recently, our understanding of DC subsets has been limited and paralleled by poor clinical translation and efficacy. We have now begun to unravel how different DC subsets develop within a complex multilayered system. These finding open up exciting possibilities for targeted manipulation of DC subsets. Furthermore, ground-breaking developments overcoming a major translational obstacle – identification of similar DC populations in mouse and man – now set the stage for significant advances in the field. Here we explore the determinants that underpin cellular and transcriptional heterogeneity within the DC network, how these influence DC distribution and localization at steady-state, and the capacity of DCs to present antigens via direct or cross-presentation during pathogen infection.

  17. CD3+CD8+CD161high Tc17 cells are depleted in HIV-infection

    DEFF Research Database (Denmark)

    Gaardbo, Julie Christine; Hartling, Hans Jakob; Thorsteinsson, Kristina;

    2012-01-01

    CD8+ Tc17 cells with pro-inflammatory properties have only recently been acknowledged, and Tc17 cells in HIV-infection are undescribed. CD3+CD8+CD161 Tc17 cells and the production of Interleukin-17 were examined in untreated and treated HIV-infected patients, HIV-HCV co-infected patients and...... healthy controls. Depletion of CD3+CD8+CD161 Tc17 cells and diminished production of Interleukin-17 in HIV-infected patients was found. The level of Tc17 cells was associated with the level of the CD4+ count in treated patients....

  18. CD4+CD25+Foxp3+ regulatory T cells depletion may attenuate the development of silica-induced lung fibrosis in mice.

    Directory of Open Access Journals (Sweden)

    Fangwei Liu

    Full Text Available BACKGROUND: Silicosis is an occupational lung disease caused by inhalation of silica dust characterized by lung inflammation and fibrosis. Previous study showed that Th1 and Th2 cytokines are involved in silicosis, but Th1/Th2 polarization during the development of silicosis is still a matter of debate. Regulatory T cells (Treg cells represent a crucial role in modulation of immune homeostasis by regulating Th1/Th2 polarization, but their possible implication in silicosis remains to be explored. METHODOLOGY/PRINCIPAL FINDINGS: To evaluate the implication of Treg cells in the development of silicosis, we generated the Treg-depleted mice model by administration of anti-CD25 mAbs and mice were exposed to silica by intratracheal instillation to establish experimental model of silica-induced lung fibrosis. The pathologic examinations show that the Treg-depleted mice are susceptive to severer inflammation in the early stage, with enhanced infiltration of inflammatory cells. Also, depletion of Treg cells causes a delay of the progress of silica-induced lung fibrosis in mice model. Further study of mRNA expression of cytokines reveals that depletion of Tregs leads to the increased production of Th1-cytokines and decreased production of Th2-cytokine. The Flow Cytometry and realtime PCR study show that Treg cells exert the modulation function both directly by expressing CTLA-4 at the inflammatory stage, and indirectly by secreting increasing amount of IL-10 and TGF-β during the fibrotic stage in silica-induced lung fibrosis. CONCLUSION/SIGNIFICANCE: Our study suggests that depletion of Tregs may attenuate the progress of silica-induced lung fibrosis and enhance Th1 response and decelerate Th1/Th2 balance toward a Th2 phenotype in silica-induced lung fibrosis. The regulatory function of Treg cells may depend on direct mechanism and indirect mechanism during the inflammatory stage of silicosis.

  19. Colon cancer and the immune system: The role of tumor invading T cells

    Institute of Scientific and Technical Information of China (English)

    Maximilian Waldner; Carl C Schimanski; Markus F Neurath

    2006-01-01

    Colon cancer is still one of the leading causes of cancer death worldwide. Although the host immune system has been shown to react against tumor cells, mainly through tumor infiltrating lymphocytes and NK cells, tumor cells may utilize different ways to escape anti-tumor immune response. Tumor infiltration of CD8+ and CD4+ (T-bet+)effector T cells has been attributed to a beneficial outcome, and the enhancement of T cell activation through T cell receptor stimulation and co-stimulatory signals provides promising strategies for immunotherapy of colon cancer. Growing evidence supports a role for the Fas/FasL system in tumor immunology, although the mechanisms and consequences of FasL activation in colon cancer are not completely understood. In animal models, depletion of regulatory T cells (CD4+ CD25+T cells) can enhance the anti-tumor immune response under certain conditions. Taken together, recent insights in the immune reaction against colon carcinoma have provided new approaches to immunotherapy,although much remains to be learned about the exact mechanisms.

  20. Rapid Protein Depletion in Human Cells by Auxin-Inducible Degron Tagging with Short Homology Donors.

    Science.gov (United States)

    Natsume, Toyoaki; Kiyomitsu, Tomomi; Saga, Yumiko; Kanemaki, Masato T

    2016-04-01

    Studying the role of essential proteins is dependent upon a method for rapid inactivation, in order to study the immediate phenotypic consequences. Auxin-inducible degron (AID) technology allows rapid depletion of proteins in animal cells and fungi, but its application to human cells has been limited by the difficulties of tagging endogenous proteins. We have developed a simple and scalable CRISPR/Cas-based method to tag endogenous proteins in human HCT116 and mouse embryonic stem (ES) cells by using donor constructs that harbor synthetic short homology arms. Using a combination of AID tagging with CRISPR/Cas, we have generated conditional alleles of essential nuclear and cytoplasmic proteins in HCT116 cells, which can then be depleted very rapidly after the addition of auxin to the culture medium. This approach should greatly facilitate the functional analysis of essential proteins, particularly those of previously unknown function.

  1. Rapid Protein Depletion in Human Cells by Auxin-Inducible Degron Tagging with Short Homology Donors

    Directory of Open Access Journals (Sweden)

    Toyoaki Natsume

    2016-04-01

    Full Text Available Studying the role of essential proteins is dependent upon a method for rapid inactivation, in order to study the immediate phenotypic consequences. Auxin-inducible degron (AID technology allows rapid depletion of proteins in animal cells and fungi, but its application to human cells has been limited by the difficulties of tagging endogenous proteins. We have developed a simple and scalable CRISPR/Cas-based method to tag endogenous proteins in human HCT116 and mouse embryonic stem (ES cells by using donor constructs that harbor synthetic short homology arms. Using a combination of AID tagging with CRISPR/Cas, we have generated conditional alleles of essential nuclear and cytoplasmic proteins in HCT116 cells, which can then be depleted very rapidly after the addition of auxin to the culture medium. This approach should greatly facilitate the functional analysis of essential proteins, particularly those of previously unknown function.

  2. Rapid Protein Depletion in Human Cells by Auxin-Inducible Degron Tagging with Short Homology Donors.

    Science.gov (United States)

    Natsume, Toyoaki; Kiyomitsu, Tomomi; Saga, Yumiko; Kanemaki, Masato T

    2016-04-01

    Studying the role of essential proteins is dependent upon a method for rapid inactivation, in order to study the immediate phenotypic consequences. Auxin-inducible degron (AID) technology allows rapid depletion of proteins in animal cells and fungi, but its application to human cells has been limited by the difficulties of tagging endogenous proteins. We have developed a simple and scalable CRISPR/Cas-based method to tag endogenous proteins in human HCT116 and mouse embryonic stem (ES) cells by using donor constructs that harbor synthetic short homology arms. Using a combination of AID tagging with CRISPR/Cas, we have generated conditional alleles of essential nuclear and cytoplasmic proteins in HCT116 cells, which can then be depleted very rapidly after the addition of auxin to the culture medium. This approach should greatly facilitate the functional analysis of essential proteins, particularly those of previously unknown function. PMID:27052166

  3. Disruption of microtubule network rescues aberrant actin comets in dynamin2-depleted cells.

    Directory of Open Access Journals (Sweden)

    Yuji Henmi

    Full Text Available A large GTPase dynamin, which is required for endocytic vesicle formation, regulates the actin cytoskeleton through its interaction with cortactin. Dynamin2 mutants impair the formation of actin comets, which are induced by Listeria monocytogenes or phosphatidylinositol-4-phosphate 5-kinase. However, the role of dynamin2 in the regulation of the actin comet is still unclear. Here we show that aberrant actin comets in dynamin2-depleted cells were rescued by disrupting of microtubule networks. Depletion of dynamin2, but not cortactin, significantly reduced the length and the speed of actin comets induced by Listeria. This implies that dynamin2 may regulate the actin comet in a cortactin-independent manner. As dynamin regulates microtubules, we investigated whether perturbation of microtubules would rescue actin comet formation in dynamin2-depleted cells. Treatment with taxol or colchicine created a microtubule-free space in the cytoplasm, and made no difference between control and dynamin2 siRNA cells. This suggests that the alteration of microtubules by dynamin2 depletion reduced the length and the speed of the actin comet.

  4. The depletion of Interleukin-8 causes cell cycle arrest and increases the efficacy of docetaxel in breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Nan [Breast Disease Center, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou (China); Chen, Liu-Hua [Department of Minimally Invasive Surgery Center, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou (China); Ye, Run-Yi [Breast Disease Center, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou (China); Lin, Ying, E-mail: frostlin@hotmail.com [Breast Disease Center, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou (China); Wang, Shen-Ming, E-mail: shenmingwang@hotmail.com [Breast Disease Center, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou (China)

    2013-02-15

    Highlights: ► IL-8 depletion affects cell cycle distribution. ► Intrinsic IL-8 mediates breast cancer cell migration and invasion. ► IL-8 siRNA down regulates key factors that control survival and metastatic pathway. ► IL-8 depletion reduces integrin β3 expression. ► IL-8 depletion increases the chemosensitivity to docetaxel. -- Abstract: IL-8 is a multi-functional pro-inflammatory chemokine, which is highly expressed in cancers, such as ER-negative breast cancer. The present study demonstrates the pervasive role of IL-8 in the malignant progression of ER-negative breast cancer. IL-8 siRNA inhibited proliferation and delayed the G1 to S cell cycle progression in MDA-MB-231 and BT549 cells. IL-8 silencing resulted in the upregulation of the CDK inhibitor p27, the downregulation of cyclin D1, and the reduction of phosphorylated-Akt and NF-κB activities. IL-8 depletion also increased the chemosensitivity to docetaxel. These results indicate a role for IL-8 in promoting tumor cell survival and resistance to docetaxel and highlight the potential therapeutic significance of IL-8 depletion in ER-negative breast cancer patients.

  5. Targeted Type 2 Alveolar Cell Depletion. A Dynamic Functional Model for Lung Injury Repair.

    Science.gov (United States)

    Garcia, Orquidea; Hiatt, Michael J; Lundin, Amber; Lee, Jooeun; Reddy, Raghava; Navarro, Sonia; Kikuchi, Alex; Driscoll, Barbara

    2016-03-01

    Type 2 alveolar epithelial cells (AEC2) are regarded as the progenitor population of the alveolus responsible for injury repair and homeostatic maintenance. Depletion of this population is hypothesized to underlie various lung pathologies. Current models of lung injury rely on either uncontrolled, nonspecific destruction of alveolar epithelia or on targeted, nontitratable levels of fixed AEC2 ablation. We hypothesized that discrete levels of AEC2 ablation would trigger stereotypical and informative patterns of repair. To this end, we created a transgenic mouse model in which the surfactant protein-C promoter drives expression of a mutant SR39TK herpes simplex virus-1 thymidine kinase specifically in AEC2. Because of the sensitivity of SR39TK, low doses of ganciclovir can be administered to these animals to induce dose-dependent AEC2 depletion ranging from mild (50%) to lethal (82%) levels. We demonstrate that specific levels of AEC2 depletion cause altered expression patterns of apoptosis and repair proteins in surviving AEC2 as well as distinct changes in distal lung morphology, pulmonary function, collagen deposition, and expression of remodeling proteins in whole lung that persist for up to 60 days. We believe SPCTK mice demonstrate the utility of cell-specific expression of the SR39TK transgene for exerting fine control of target cell depletion. Our data demonstrate, for the first time, that specific levels of type 2 alveolar epithelial cell depletion produce characteristic injury repair outcomes. Most importantly, use of these mice will contribute to a better understanding of the role of AEC2 in the initiation of, and response to, lung injury.

  6. Hematopoietic Stem and Immune Cells in Chronic HIV Infection

    Directory of Open Access Journals (Sweden)

    Jielin Zhang

    2015-01-01

    Full Text Available Hematopoietic stem cell (HSC belongs to multipotent adult somatic stem cells. A single HSC can reconstitute the entire blood system via self-renewal, differentiation into all lineages of blood cells, and replenishment of cells lost due to attrition or disease in a person’s lifetime. Although all blood and immune cells derive from HSC, immune cells, specifically immune memory cells, have the properties of HSC on self-renewal and differentiation into lineage effector cells responding to the invading pathogens. Moreover, the interplay between immune memory cell and viral pathogen determines the course of a viral infection. Here, we state our point of view on the role of blood stem and progenitor cell in chronic HIV infection, with a focus on memory CD4 T-cell in the context of HIV/AIDS eradication and cure.

  7. Hematopoietic Stem and Immune Cells in Chronic HIV Infection.

    Science.gov (United States)

    Zhang, Jielin; Crumpacker, Clyde

    2015-01-01

    Hematopoietic stem cell (HSC) belongs to multipotent adult somatic stem cells. A single HSC can reconstitute the entire blood system via self-renewal, differentiation into all lineages of blood cells, and replenishment of cells lost due to attrition or disease in a person's lifetime. Although all blood and immune cells derive from HSC, immune cells, specifically immune memory cells, have the properties of HSC on self-renewal and differentiation into lineage effector cells responding to the invading pathogens. Moreover, the interplay between immune memory cell and viral pathogen determines the course of a viral infection. Here, we state our point of view on the role of blood stem and progenitor cell in chronic HIV infection, with a focus on memory CD4 T-cell in the context of HIV/AIDS eradication and cure. PMID:26300920

  8. Dendritic cell-based vaccines in the setting of peripheral blood stem cell transplantation: CD34+ cell-depleted mobilized peripheral blood can serve as a source of potent dendritic cells.

    Science.gov (United States)

    Choi, D; Perrin, M; Hoffmann, S; Chang, A E; Ratanatharathorn, V; Uberti, J; McDonagh, K T; Mulé, J J

    1998-11-01

    We are investigating the use of tumor-pulsed dendritic cell (DC)-based vaccines in the treatment of patients with advanced cancer. In the current study, we evaluated the feasibility of obtaining both CD34+ hematopoietic stem/ progenitor cells (HSCs) and functional DCs from the same leukapheresis collection in adequate numbers for both peripheral blood stem cell transplantation (PBSCT) and immunization purposes, respectively. Leukapheresis collections of mobilized peripheral blood mononuclear cells (PBMCs) were obtained from normal donors receiving granulocyte colony-stimulating factor (G-CSF) (for allogeneic PBSCT) and from intermediate grade non-Hodgkin's lymphoma or multiple myeloma patients receiving cyclophosphamide plus G-CSF (for autologous PBSCT). High enrichment of CD34+ HSCs was obtained using an immunomagnetic bead cell separation device. After separation, the negative fraction of mobilized PBMCs from normal donors and cancer patients contained undetectable levels of CD34+ HSCs by flow cytometry. This fraction of cells was then subjected to plastic adherence, and the adherent cells were cultured for 7 days in GM-CSF (100 ng/ml) and interleukin 4 (50 ng/ml) followed by an additional 7 days in GM-CSF, interleukin 4, and tumor necrosis factor alpha (10 ng/ml) to generate DCs. Harvested DCs represented yields of 4.1+/-1.4 and 5.8+/-5.4% of the initial cells plated from the CD34+ cell-depleted mobilized PBMCs of normal donors and cancer patients, respectively, and displayed a high level expression of CD80, CD86, HLA-DR, and CD11c but not CD14. This phenotypic profile was similar to that of DCs derived from non-CD34+ cell-depleted mobilized PBMCs. DCs generated from CD34+ cell-depleted mobilized PBMCs elicited potent antitetanus as well as primary allogeneic T-cell proliferative responses in vitro, which were equivalent to DCs derived from non-CD34+ cell-depleted mobilized PBMCs. Collectively, these results demonstrate the feasibility of obtaining both DCs and

  9. Calvatia lilacina protein-extract induces apoptosis through glutathione depletion in human colorectal carcinoma cells.

    Science.gov (United States)

    Tsay, Jwu-Guh; Chung, King-Thom; Yeh, Chung-Hung; Chen, Wan-Ling; Chen, Chi-Hung; Lin, Martin Hsiu-Chu; Lu, Fung-Jou; Chiou, Jeng-Fong; Chen, Ching-Hsein

    2009-02-25

    This paper reports that a novel protein extract isolated from Calvatia lilacina (CL) can induce cell death against four types of human colorectal cancer cells. Importantly, CL was shown to be free of apoptotic effects against normal rat liver cells. We have also identified that CL-induced glutathione (GSH) depletion is the major contributor responsible for the apoptotic cell death induction of SW 480 cells, as evidenced by the observation that exogenously added N-acetylcysteine (NAC), or GSH, but not vitamin C, could offer a near complete protection of CL-treated cells against apoptotic cell death. Furthermore, the participation of reactive oxygen species (ROS) evoked a drop in the transmembrane potential (Delta Psi(m)) in the CL-induced apoptotic cell death. This observation can only be deemed as a minor pathway due to the fact that cyclosporine A (CyA) could only partially rescue the CL-treated cells from apoptotic cell death. Likewise, despite the fact that CL could induce the upregulation of Bax, its knockdown via siRNA (48 h) failed to completely mitigate apoptotic cell death, indicating that its role in this apoptotic process was insignificant. To further explore the possible underlying mechanism associated with CL-induced GSH depletion, we proceeded to determine the effect of CL on the cellular gamma-glutamylcysteine synthetase (gamma-GCS), a rate-limiting enzyme responsible for GSH biosynthesis, and demonstrated that indeed gamma-GCS could be repressed by CL. Taken together, we report here for the first time that the anticancer effect of CL on human colorectal cancer cells is mediated through GSH depletion mechanism rather than a ROS-mediated killing process. This functional attribute of CL can thus provide the basis for the strategic design of a treatment of colorectal cancer.

  10. In vivo protein synthesis determinations in human immune cells

    OpenAIRE

    Januszkiewicz, Anna

    2005-01-01

    Intact immune responses are essential for defeating severe infections in individual patients. Insufficient function of the immune system contributes to a poor prognosis in these patients, in particular the ICU patients. Nevertheless, the immune system function is not easily monitored and evaluated. The ongoing metabolic activity of immune competent cells is reflected by their in vivo protein synthesis rate. The aim of this thesis was to apply in vivo protein synthesis measur...

  11. Recursion-based depletion of human immunodeficiency virus-specific naive CD4(+) T cells may facilitate persistent viral replication and chronic viraemia leading to acquired immunodeficiency syndrome.

    Science.gov (United States)

    Tsukamoto, Tetsuo; Yamamoto, Hiroyuki; Okada, Seiji; Matano, Tetsuro

    2016-09-01

    Although antiretroviral therapy has made human immunodeficiency virus (HIV) infection a controllable disease, it is still unclear how viral replication persists in untreated patients and causes CD4(+) T-cell depletion leading to acquired immunodeficiency syndrome (AIDS) in several years. Theorists tried to explain it with the diversity threshold theory in which accumulated mutations in the HIV genome make the virus so diverse that the immune system will no longer be able to recognize all the variants and fail to control the viraemia. Although the theory could apply to a number of cases, macaque AIDS models using simian immunodeficiency virus (SIV) have shown that failed viral control at the set point is not always associated with T-cell escape mutations. Moreover, even monkeys without a protective major histocompatibility complex (MHC) allele can contain replication of a super infected SIV following immunization with a live-attenuated SIV vaccine, while those animals are not capable of fighting primary SIV infection. Here we propose a recursion-based virus-specific naive CD4(+) T-cell depletion hypothesis through thinking on what may happen in individuals experiencing primary immunodeficiency virus infection. This could explain the mechanism for impairment of virus-specific immune response in the course of HIV infection. PMID:27515208

  12. Recent advances in haploidentical hematopoietic stem cell transplantation using ex vivo T cell-depleted graft in children and adolescents.

    Science.gov (United States)

    Im, Ho Joon; Koh, Kyung-Nam; Seo, Jong Jin

    2016-03-01

    Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative treatment for children and adolescents with various malignant and non-malignant diseases. While human leukocyte antigen (HLA)-identical sibling donor is the preferred choice, matched unrelated volunteer donor is another realistic option for successful HSCT. Unfortunately, it is not always possible to find a HLA-matched donor for patients requiring HSCT, leading to a considerable number of deaths of patients without undergoing transplantation. Alternatively, allogeneic HSCT from haploidentical family members could provide donors for virtually all patients who need HSCT. Although the early attempts at allogeneic HSCT from haploidentical family donor (HFD) were disappointing, recent advances in the effective ex vivo depletion of T cells or unmanipulated in vivo regulation of T cells, better supportive care, and optimal conditioning regimens have significantly improved the outcomes of haploidentical HSCT. The ex vivo techniques used to remove T cells have evolved from the selection of CD34(+) hematopoietic stem cell progenitors to the depletion of CD3(+) cells, and more recently to the depletion of αβ(+) T cells. The recent emerging evidence for ex vivo T cell-depleted haploidentical HSCT has provided additional therapeutic options for pediatric patients with diseases curable by HSCT but has not found a suitable related or unrelated donor. This review discusses recent advances in haploidentical HSCT, focusing on transplant using ex vivo T cell-depleted grafts. In addition, our experiences with this novel approach for the treatment of pediatric patients with malignant and non-malignant diseases are described.

  13. Intestinal dendritic cells in the regulation of mucosal immunity

    DEFF Research Database (Denmark)

    Bekiaris, Vasileios; Persson, Emma K.; Agace, William Winston

    2014-01-01

    immune cells within the mucosa must suitably respond to maintain intestinal integrity, while also providing the ability to mount effective immune responses to potential pathogens. Dendritic cells (DCs) are sentinel immune cells that play a central role in the initiation and differentiation of adaptive...... immune responses. In the intestinal mucosa, DCs are located diffusely throughout the intestinal lamina propria, within gut-associated lymphoid tissues, including Peyer's patches and smaller lymphoid aggregates, as well as in intestinal-draining lymph nodes, including mesenteric lymph nodes....... The recognition that dietary nutrients and microbial communities in the intestine influence both mucosal and systemic immune cell development and function as well as immune-mediated disease has led to an explosion of literature in mucosal immunology in recent years and a growing interest in the functionality...

  14. Innate immune cell response upon Candida albicans infection.

    Science.gov (United States)

    Qin, Yulin; Zhang, Lulu; Xu, Zheng; Zhang, Jinyu; Jiang, Yuan-Ying; Cao, Yongbing; Yan, Tianhua

    2016-07-01

    Candida albicans is a polymorphic fungus which is the predominant cause of superficial and deep tissue fungal infections. This microorganism has developed efficient strategies to invade the host and evade host defense systems. However, the host immune system will be prepared for defense against the microbe by recognition of receptors, activation of signal transduction pathways and cooperation of immune cells. As a consequence, C. albicans could either be eliminated by immune cells rapidly or disseminate hematogenously, leading to life-threatening systemic infections. The interplay between Candida albicans and the host is complex, requiring recognition of the invaded pathogens, activation of intricate pathways and collaboration of various immune cells. In this review, we will focus on the effects of innate immunity that emphasize the first line protection of host defense against invaded C. albicans including the basis of receptor-mediated recognition and the mechanisms of cell-mediated immunity. PMID:27078171

  15. Alpha/Beta T-Cell Depleted Grafts as an Immunological Booster to Treat Graft Failure after Hematopoietic Stem Cell Transplantation with HLA-Matched Related and Unrelated Donors

    Directory of Open Access Journals (Sweden)

    E. Rådestad

    2014-01-01

    Full Text Available Allogeneic hematopoietic stem cell transplantation is associated with several complications and risk factors, for example, graft versus host disease (GVHD, viral infections, relapse, and graft rejection. While high levels of CD3+ cells in grafts can contribute to GVHD, they also promote the graft versus leukemia (GVL effect. Infusions of extra lymphocytes from the original stem cell donor can be used as a treatment after transplantation for relapse or poor immune reconstitution but also they increase the risk for GVHD. In peripheral blood, 95% of T-cells express the αβ T-cell receptor and the remaining T-cells express the γδ T-cell receptor. As αβ T-cells are the primary mediators of GVHD, depleting them from the graft should reduce this risk. In this pilot study, five patients transplanted with HLA-matched related and unrelated donors were treated with αβ T-cell depleted stem cell boosts. The majority of γδ T-cells in the grafts expressed Vδ2 and/or Vγ9. Most patients receiving αβ-depleted stem cell boosts increased their levels of white blood cells, platelets, and/or granulocytes 30 days after infusion. No signs of GVHD or other side effects were detected. A larger pool of patients with longer follow-up time is needed to confirm the data in this study.

  16. PTEN deficiency and mutant p53 confer glucose-addiction to thyroid cancer cells: impact of glucose depletion on cell proliferation, cell survival, autophagy and cell migration.

    Science.gov (United States)

    Morani, Federica; Phadngam, Suratchanee; Follo, Carlo; Titone, Rossella; Thongrakard, Visa; Galetto, Alessandra; Alabiso, Oscar; Isidoro, Ciro

    2014-07-01

    Proliferating cancer cells oxidize glucose through the glycolytic pathway. Since this metabolism is less profitable in terms of ATP production, cancer cells consume large quantity of glucose, and those that experience insufficient blood supply become glucose-addicted. We have analyzed the response to glucose depletion in WRO and FTC133 follicular thyroid cancer cells, which differ in the expression of two key regulators of the glucose metabolism. WRO cells, which express wild type p53 and PTEN, showed a higher rate of cell proliferation and were much less sensitive to glucose-depletion than FTC133 cells, which are PTEN null and express mutant p53. Glucose depletion slowed-down the autophagy flux in FTC133 cells, not in WRO cells. In a wound-healing assay, WRO cells were shown to migrate faster than FTC133 cells. Glucose depletion slowed down the cell migration rate, and these effects were more evident in FTC133 cells. Genetic silencing of either wild-type PTEN or p53 in WRO cells resulted in increased uptake of glucose, whereas the ectopic expression of PTEN in FTC133 cells resulted in diminished glucose uptake. In conclusion, compared to WRO, FTC133 cells were higher glucose up-taker and consumer. These data do not support the general contention that cancer cells lacking PTEN or expressing the mutant p53R273H are more aggressive and prone to better face glucose depletion. We propose that concurrent PTEN deficiency and mutant p53 leads to a glucose-addiction state that renders the cancer cell more sensitive to glucose restriction. The present observation substantiates the view that glucose-restriction may be an adjuvant strategy to combat these tumours. PMID:25221641

  17. Zika Virus Depletes Neural Progenitors in Human Cerebral Organoids through Activation of the Innate Immune Receptor TLR3.

    Science.gov (United States)

    Dang, Jason; Tiwari, Shashi Kant; Lichinchi, Gianluigi; Qin, Yue; Patil, Veena S; Eroshkin, Alexey M; Rana, Tariq M

    2016-08-01

    Emerging evidence from the current outbreak of Zika virus (ZIKV) indicates a strong causal link between Zika and microcephaly. To investigate how ZIKV infection leads to microcephaly, we used human embryonic stem cell-derived cerebral organoids to recapitulate early stage, first trimester fetal brain development. Here we show that a prototype strain of ZIKV, MR766, efficiently infects organoids and causes a decrease in overall organoid size that correlates with the kinetics of viral copy number. The innate immune receptor Toll-like-Receptor 3 (TLR3) was upregulated after ZIKV infection of human organoids and mouse neurospheres and TLR3 inhibition reduced the phenotypic effects of ZIKV infection. Pathway analysis of gene expression changes during TLR3 activation highlighted 41 genes also related to neuronal development, suggesting a mechanistic connection to disrupted neurogenesis. Together, therefore, our findings identify a link between ZIKV-mediated TLR3 activation, perturbed cell fate, and a reduction in organoid volume reminiscent of microcephaly. PMID:27162029

  18. Functional cure of SIVagm infection in rhesus macaques results in complete recovery of CD4+ T cells and is reverted by CD8+ cell depletion.

    Directory of Open Access Journals (Sweden)

    Ivona Pandrea

    2011-08-01

    Full Text Available Understanding the mechanism of infection control in elite controllers (EC may shed light on the correlates of control of disease progression in HIV infection. However, limitations have prevented a clear understanding of the mechanisms of elite controlled infection, as these studies can only be performed at randomly selected late time points in infection, after control is achieved, and the access to tissues is limited. We report that SIVagm infection is elite-controlled in rhesus macaques (RMs and therefore can be used as an animal model for EC HIV infection. A robust acute infection, with high levels of viral replication and dramatic mucosal CD4(+ T cell depletion, similar to pathogenic HIV-1/SIV infections of humans and RMs, was followed by complete and durable control of SIVagm replication, defined as: undetectable VLs in blood and tissues beginning 72 to 90 days postinoculation (pi and continuing at least 4 years; seroreversion; progressive recovery of mucosal CD4(+ T cells, with complete recovery by 4 years pi; normal levels of T cell immune activation, proliferation, and apoptosis; and no disease progression. This "functional cure" of SIVagm infection in RMs could be reverted after 4 years of control of infection by depleting CD8 cells, which resulted in transient rebounds of VLs, thus suggesting that control may be at least in part immune mediated. Viral control was independent of MHC, partial APOBEC restriction was not involved in SIVagm control in RMs and Trim5 genotypes did not impact viral replication. This new animal model of EC lentiviral infection, in which complete control can be predicted in all cases, permits research on the early events of infection in blood and tissues, before the defining characteristics of EC are evident and when host factors are actively driving the infection towards the EC status.

  19. In situ depletion of CD4(+) T cells in human skin by Zanolimumab

    DEFF Research Database (Denmark)

    Villadsen, L.S.; Skov, L.; Dam, T.N.;

    2007-01-01

    -driving T cells in situ may therefore be a useful approach in the treatment of inflammatory and malignant skin diseases. Depletion of CD4(+) T cells in intact inflamed human skin tissue by Zanolimumab, a fully human therapeutic monoclonal antibody (IgG1, kappa) against CD4, was studied in a human psoriasis......CD4(+) T cells, in activated or malignant form, are involved in a number of diseases including inflammatory skin diseases such as psoriasis, and T cell lymphomas such as the majority of cutaneous T cell lymphomas (CTCL). Targeting CD4 with an antibody that inhibits and/or eliminates disease...... xenograft mouse model. Zanolimumab treatment was shown to induce a significant reduction in the numbers of inflammatory mononuclear cells in upper dermis. This reduction in inflammatory mononuclear cells in situ was primarily due to a significant reduction in the numbers of skin-infiltrating CD4(+), but not...

  20. Differential Protein Network Analysis of the Immune Cell Lineage

    Directory of Open Access Journals (Sweden)

    Trevor Clancy

    2014-01-01

    Full Text Available Recently, the Immunological Genome Project (ImmGen completed the first phase of the goal to understand the molecular circuitry underlying the immune cell lineage in mice. That milestone resulted in the creation of the most comprehensive collection of gene expression profiles in the immune cell lineage in any model organism of human disease. There is now a requisite to examine this resource using bioinformatics integration with other molecular information, with the aim of gaining deeper insights into the underlying processes that characterize this immune cell lineage. We present here a bioinformatics approach to study differential protein interaction mechanisms across the entire immune cell lineage, achieved using affinity propagation applied to a protein interaction network similarity matrix. We demonstrate that the integration of protein interaction networks with the most comprehensive database of gene expression profiles of the immune cells can be used to generate hypotheses into the underlying mechanisms governing the differentiation and the differential functional activity across the immune cell lineage. This approach may not only serve as a hypothesis engine to derive understanding of differentiation and mechanisms across the immune cell lineage, but also help identify possible immune lineage specific and common lineage mechanism in the cells protein networks.

  1. Innate immune control of EBV-infected B cells by invariant natural killer T cells.

    Science.gov (United States)

    Chung, Brian K; Tsai, Kevin; Allan, Lenka L; Zheng, Dong Jun; Nie, Johnny C; Biggs, Catherine M; Hasan, Mohammad R; Kozak, Frederick K; van den Elzen, Peter; Priatel, John J; Tan, Rusung

    2013-10-10

    Individuals with X-linked lymphoproliferative disease lack invariant natural killer T (iNKT) cells and are exquisitely susceptible to Epstein-Barr virus (EBV) infection. To determine whether iNKT cells recognize or regulate EBV, resting B cells were infected with EBV in the presence or absence of iNKT cells. The depletion of iNKT cells increased both viral titers and the frequency of EBV-infected B cells. However, EBV-infected B cells rapidly lost expression of the iNKT cell receptor ligand CD1d, abrogating iNKT cell recognition. To determine whether induced CD1d expression could restore iNKT recognition in EBV-infected cells, lymphoblastoid cell lines (LCL) were treated with AM580, a synthetic retinoic acid receptor-α agonist that upregulates CD1d expression via the nuclear protein, lymphoid enhancer-binding factor 1 (LEF-1). AM580 significantly reduced LEF-1 association at the CD1d promoter region, induced CD1d expression on LCL, and restored iNKT recognition of LCL. CD1d-expressing LCL elicited interferon γ secretion and cytotoxicity by iNKT cells even in the absence of exogenous antigen, suggesting an endogenous iNKT antigen is expressed during EBV infection. These data indicate that iNKT cells may be important for early, innate control of B cell infection by EBV and that downregulation of CD1d may allow EBV to circumvent iNKT cell-mediated immune recognition.

  2. Determination of Mother Centriole Maturation in CPAP-Depleted Cells Using the Ninein Antibody

    OpenAIRE

    Lee, Miseon; Rhee, Kunsoo

    2015-01-01

    Background Mutations in centrosomal protein genes have been identified in a number of genetic diseases in brain development, including microcephaly. Centrosomal P4.1-associated protein (CPAP) is one of the causal genes implicated in primary microcephaly. We previously proposed that CPAP is essential for mother centriole maturation during mitosis. Methods We immunostained CPAP-depleted cells using the ninein antibody, which selectively detects subdistal appendages in mature mother centrioles. ...

  3. Transformation of human osteoblast cells to the tumorigenic phenotype by depleted uranium-uranyl chloride.

    OpenAIRE

    Miller, A C; Blakely, W F; Livengood, D; Whittaker, T; Xu, J.; Ejnik, J W; Hamilton, M. M.; Parlette, E; John, T S; Gerstenberg, H M; Hsu, H

    1998-01-01

    Depleted uranium (DU) is a dense heavy metal used primarily in military applications. Although the health effects of occupational uranium exposure are well known, limited data exist regarding the long-term health effects of internalized DU in humans. We established an in vitro cellular model to study DU exposure. Microdosimetric assessment, determined using a Monte Carlo computer simulation based on measured intracellular and extracellular uranium levels, showed that few (0.0014%) cell nuclei...

  4. Mechanical fibrinogen-depletion supports heparin-free mesenchymal stem cell propagation in human platelet lysate

    OpenAIRE

    Laner-Plamberger, Sandra; Lener, Thomas; Schmid, Doris; Streif, Doris A.; Salzer, Tina; Öller, Michaela; Hauser-Kronberger, Cornelia; Fischer, Thorsten; Jacobs, Volker R.; Schallmoser, Katharina; Gimona, Mario; Rohde, Eva

    2015-01-01

    Background Pooled human platelet lysate (pHPL) is an efficient alternative to xenogenic supplements for ex vivo expansion of mesenchymal stem cells (MSCs) in clinical studies. Currently, porcine heparin is used in pHPL-supplemented medium to prevent clotting due to plasmatic coagulation factors. We therefore searched for an efficient and reproducible medium preparation method that avoids clot formation while omitting animal-derived heparin. Methods We established a protocol to deplete fibrino...

  5. Exosomes and nanotubes: Control of immune cell communication.

    Science.gov (United States)

    McCoy-Simandle, Kessler; Hanna, Samer J; Cox, Dianne

    2016-02-01

    Cell-cell communication is critical to coordinate the activity and behavior of a multicellular organism. The cells of the immune system not only must communicate with similar cells, but also with many other cell types in the body. Therefore, the cells of the immune system have evolved multiple ways to communicate. Exosomes and tunneling nanotubes (TNTs) are two means of communication used by immune cells that contribute to immune functions. Exosomes are small membrane vesicles secreted by most cell types that can mediate intercellular communication and in the immune system they are proposed to play a role in antigen presentation and modulation of gene expression. TNTs are membranous structures that mediate direct cell-cell contact over several cell diameters in length (and possibly longer) and facilitate the interaction and/or the transfer of signals, material and other cellular organelles between connected cells. Recent studies have revealed additional, but sometimes conflicting, structural and functional features of both exosomes and TNTs. Despite the new and exciting information in exosome and TNT composition, origin and in vitro function, biologically significant functions are still being investigated and determined. In this review, we discuss the current field regarding exosomes and TNTs in immune cells providing evaluation and perspectives of the current literature.

  6. Strongyloides ratti infection induces expansion of Foxp3+ regulatory T cells that interfere with immune response and parasite clearance in BALB/c mice.

    Science.gov (United States)

    Blankenhaus, Birte; Klemm, Ulrike; Eschbach, Marie-Luise; Sparwasser, Tim; Huehn, Jochen; Kühl, Anja A; Loddenkemper, Christoph; Jacobs, Thomas; Breloer, Minka

    2011-04-01

    To escape expulsion by their host's immune system, pathogenic nematodes exploit regulatory pathways that are intrinsic parts of the mammalian immune system, such as regulatory T cells (Tregs). Using depletion of Treg mice, we showed that Foxp3(+) Treg numbers increased rapidly during infection with the nematode Strongyloides ratti. Transient depletion of Tregs during the first days of infection led to dramatically reduced worm burden and larval output, without aggravation of immune pathology. The transient absence of Tregs during primary infection did not interfere with the generation of protective memory. Depletion of Tregs at later time points of infection (i.e., day 4) did not improve resistance, suggesting that Tregs exert their counterregulatory function during the priming of S. ratti-specific immune responses. Improved resistance upon early Treg depletion was accompanied by accelerated and prolonged mast cell activation and increased production of types 1 and 2 cytokines. In contrast, the blockade of the regulatory receptor CTLA-4 specifically increased nematode-specific type 2 cytokine production. Despite this improved immune response, resistance to the infection was only marginally improved. Taken together, we provide evidence that Treg expansion during S. ratti infection suppresses the protective immune response to this pathogenic nematode and, thus, represents a mechanism of immune evasion. PMID:21335490

  7. HRP-2 determines HIV-1 integration site selection in LEDGF/p75 depleted cells

    Directory of Open Access Journals (Sweden)

    Schrijvers Rik

    2012-10-01

    Full Text Available Abstract Background Lens epithelium–derived growth factor (LEDGF/p75 is a cellular co-factor of HIV-1 integrase (IN that tethers the viral pre-integration complex to the host cell chromatin and determines the genome wide integration site distribution pattern of HIV-1. Recently, we demonstrated that HIV-1 replication was reduced in LEDGF/p75 knockout (KO cells. LEDGF/p75 KO significantly altered the integration site preference of HIV-1, but the pattern remained distinct from a computationally generated matched random control set (MRC, suggesting the presence of an alternative tethering factor. We previously identified Hepatoma-derived growth factor related protein 2 (HRP-2 as a factor mediating LEDGF/p75-independent HIV-1 replication. However, the role of HRP-2 in HIV-1 integration site selection was not addressed. Findings We studied the HIV-1 integration site distribution in the presence and absence of LEDGF/p75 and/or HRP-2, and in LEDGF/p75-depleted cells that overexpress HRP-2. We show that HRP-2 functions as a co-factor of HIV-1 IN in LEDGF/p75-depleted cells. Endogenous HRP-2 only weakly supported HIV-1 replication in LEDGF/p75 depleted cells. However, HRP-2 overexpression rescued HIV-1 replication and restored integration in RefSeq genes to wild-type levels. Additional HRP-2 KD in LEDGF/p75-depleted cells reduces integration frequency in transcription units and shifts the integration distribution towards random. Conclusions We demonstrate that HRP-2 overexpression can compensate for the absence of LEDGF/p75 and indicate that the residual bias in integration targeting observed in the absence of LEDGF/p75 can be ascribed to HRP-2. Knockdown of HRP-2 upon LEDGF/p75 depletion results in a more random HIV-1 integration pattern. These data therefore reinforce the understanding that LEDGF/p75 is the dominant HIV-1 IN co-factor.

  8. The Role of the Immune Response in Merkel Cell Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Triozzi, Pierre L., E-mail: triozzp@ccf.org [Taussig Cancer Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195 (United States); Fernandez, Anthony P. [Departments of Dermatology and Anatomic Pathology, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195 (United States)

    2013-02-28

    Merkel cell carcinoma (MCC) is an aggressive neuroendocrine skin cancer. The Merkel cell polyomavirus (MCPyV) is implicated in its pathogenesis. Immune mechanisms are also implicated. Patients who are immunosuppressed have an increased risk. There is evidence that high intratumoral T-cell counts and immune transcripts are associated with favorable survival. Spontaneous regressions implicate immune effector mechanisms. Immunogenicity is also supported by observation of autoimmune paraneoplastic syndromes. Case reports suggest that immune modulation, including reduction of immune suppression, can result in tumor regression. The relationships between MCPyV infection, the immune response, and clinical outcome, however, remain poorly understood. Circulating antibodies against MCPyV antigens are present in most individuals. MCPyV-reactive T cells have been detected in both MCC patients and control subjects. High intratumoral T-cell counts are also associated with favorable survival in MCPyV-negative MCC. That the immune system plays a central role in preventing and controlling MCC is supported by several observations. MCCs often develop, however, despite the presence of humoral and cellular immune responses. A better understanding on how MCPyV and MCC evade the immune response will be necessary to develop effective immunotherapies.

  9. Mesenchymal stromal cells engage complement and complement receptor bearing innate effector cells to modulate immune responses.

    Directory of Open Access Journals (Sweden)

    Guido Moll

    Full Text Available Infusion of human third-party mesenchymal stromal cells (MSCs appears to be a promising therapy for acute graft-versus-host disease (aGvHD. To date, little is known about how MSCs interact with the body's innate immune system after clinical infusion. This study shows, that exposure of MSCs to blood type ABO-matched human blood activates the complement system, which triggers complement-mediated lymphoid and myeloid effector cell activation in blood. We found deposition of complement component C3-derived fragments iC3b and C3dg on MSCs and fluid-phase generation of the chemotactic anaphylatoxins C3a and C5a. MSCs bound low amounts of immunoglobulins and lacked expression of complement regulatory proteins MCP (CD46 and DAF (CD55, but were protected from complement lysis via expression of protectin (CD59. Cell-surface-opsonization and anaphylatoxin-formation triggered complement receptor 3 (CD11b/CD18-mediated effector cell activation in blood. The complement-activating properties of individual MSCs were furthermore correlated with their potency to inhibit PBMC-proliferation in vitro, and both effector cell activation and the immunosuppressive effect could be blocked either by using complement inhibitor Compstatin or by depletion of CD14/CD11b-high myeloid effector cells from mixed lymphocyte reactions. Our study demonstrates for the first time a major role of the complement system in governing the immunomodulatory activity of MSCs and elucidates how complement activation mediates the interaction with other immune cells.

  10. Innate immune pattern recognition: a cell biological perspective.

    Science.gov (United States)

    Brubaker, Sky W; Bonham, Kevin S; Zanoni, Ivan; Kagan, Jonathan C

    2015-01-01

    Receptors of the innate immune system detect conserved determinants of microbial and viral origin. Activation of these receptors initiates signaling events that culminate in an effective immune response. Recently, the view that innate immune signaling events rely on and operate within a complex cellular infrastructure has become an important framework for understanding the regulation of innate immunity. Compartmentalization within this infrastructure provides the cell with the ability to assign spatial information to microbial detection and regulate immune responses. Several cell biological processes play a role in the regulation of innate signaling responses; at the same time, innate signaling can engage cellular processes as a form of defense or to promote immunological memory. In this review, we highlight these aspects of cell biology in pattern-recognition receptor signaling by focusing on signals that originate from the cell surface, from endosomal compartments, and from within the cytosol.

  11. Suppression of the CD8 T cell response by human papillomavirus type 16 E7 occurs in Langerhans cell-depleted mice

    Science.gov (United States)

    Jemon, K.; Leong, C.-M.; Ly, K.; Young, S. L.; McLellan, A. D.; Hibma, M. H.

    2016-01-01

    Human papillomavirus (HPV) is an epitheliotropic virus that is the primary causal agent for cervical cancer. Langerhans cells (LC) are skin antigen presenting cells that are reduced in number in HPV-infected skin. The aim of this study was to understand the immune-modulatory effects of HPV16 E7 on LC and on the CD8 T cell response to a skin-expressed antigen. To test this, HPV16 E7 was expressed in mouse skin keratinocytes with the model antigen ovalbumin (Ova). Similar to what is observed in HPV-infected human skin, LC numbers were significantly reduced in E7-expressing mouse skin. This shows that expression of the E7 protein alone is sufficient to mediate LC depletion. Expression of E7 with Ova in keratinocytes strongly suppressed the Ova-specific CD8+ T cell response in the skin draining lymph node. When tested in LC-ablated mice, the CD8 T cell response to skin-expressed Ova in control mice was not affected, nor was the T cell response to Ova restored in E7-expressing skin. These data indicate a role for E7 in regulation of LC homeostasis in the skin and in suppression of antigen specific CD8 T cell expansion, but suggest that these two effects occur independent of each other. PMID:27708419

  12. Advances in colloidal quantum dot solar cells: The depleted-heterojunction device

    International Nuclear Information System (INIS)

    Colloidal quantum dot (CQD) photovoltaics combine low-cost solution processibility with quantum size-effect tunability to match absorption with the solar spectrum. Recent advances in CQD photovoltaics have led to 3.6% AM1.5 solar power conversion efficiencies. Here we report CQD photovoltaic devices on transparent conductive oxides and show that our devices rely on the establishment of a depletion region for field-driven charge transport and separation. The resultant depleted-heterojunction solar cells provide a 5.1% AM1.5 power conversion efficiency. The devices employ infrared-bandgap size-effect-tuned PbS colloidal quantum dots, enabling broadband harvesting of the solar spectrum.

  13. RETRACTED: Advances in colloidal quantum dot solar cells: The depleted-heterojunction device

    KAUST Repository

    Kramer, Illan J.

    2011-08-01

    Colloidal quantum dot (CQD) photovoltaics combine low-cost solution processibility with quantum size-effect tunability to match absorption with the solar spectrum. Recent advances in CQD photovoltaics have led to 3.6% AM1.5 solar power conversion efficiencies. Here we report CQD photovoltaic devices on transparent conductive oxides and show that our devices rely on the establishment of a depletion region for field-driven charge transport and separation. The resultant depleted-heterojunction solar cells provide a 5.1% AM1.5 power conversion efficiency. The devices employ infrared-bandgap size-effect-tuned PbS colloidal quantum dots, enabling broadband harvesting of the solar spectrum. © 2010 Elsevier B.V.

  14. Norcantharidin induced DU145 cell apoptosis through ROS-mediated mitochondrial dysfunction and energy depletion.

    Science.gov (United States)

    Shen, Bo; He, Pei-Jie; Shao, Chun-Lin

    2013-01-01

    Norcantharidin (NCTD), a demethylated analog of cantharidin derived from blister beetles, has attracted considerable attentions in recent years due to their definitely toxic properties and the noteworthy advantages in stimulating bone marrow and increasing the peripheral leukocytes. Hence, it is worth studying the anti-tumor effect of NCTD on human prostate cancer cells DU145. It was found that after the treatment of NCTD with different concentrations (25-100 μM), the cell proliferation was significantly inhibited, which led to the appearance of micronucleus (MN). Moreover, the cells could be killed in a dose-/time-dependent manner along with the reduction of PCNA (proliferating cell nuclear antigen) expression, destruction of mitochondrial membrane potential (MMP), down-regulation of MnSOD, induction of ROS, depletion of ATP, and activation of AMPK (Adenosine 5'-monophosphate -activated protein kinase) . In addition, a remarkable release of cytochrome c was found in the cells exposed to 100 μM NCTD and exogenous SOD-PEG could eliminate the generation of NCTD-induced MN. In conclusion, our studies indicated that NCTD could induce the collapse of MMP and mitochondria dysfunction. Accumulation of intercellular ROS could eventually switch on the apoptotic pathway by causing DNA damage and depleting ATP. PMID:24367681

  15. Norcantharidin induced DU145 cell apoptosis through ROS-mediated mitochondrial dysfunction and energy depletion.

    Directory of Open Access Journals (Sweden)

    Bo Shen

    Full Text Available Norcantharidin (NCTD, a demethylated analog of cantharidin derived from blister beetles, has attracted considerable attentions in recent years due to their definitely toxic properties and the noteworthy advantages in stimulating bone marrow and increasing the peripheral leukocytes. Hence, it is worth studying the anti-tumor effect of NCTD on human prostate cancer cells DU145. It was found that after the treatment of NCTD with different concentrations (25-100 μM, the cell proliferation was significantly inhibited, which led to the appearance of micronucleus (MN. Moreover, the cells could be killed in a dose-/time-dependent manner along with the reduction of PCNA (proliferating cell nuclear antigen expression, destruction of mitochondrial membrane potential (MMP, down-regulation of MnSOD, induction of ROS, depletion of ATP, and activation of AMPK (Adenosine 5'-monophosphate -activated protein kinase . In addition, a remarkable release of cytochrome c was found in the cells exposed to 100 μM NCTD and exogenous SOD-PEG could eliminate the generation of NCTD-induced MN. In conclusion, our studies indicated that NCTD could induce the collapse of MMP and mitochondria dysfunction. Accumulation of intercellular ROS could eventually switch on the apoptotic pathway by causing DNA damage and depleting ATP.

  16. Human intestinal dendritic cells as controllers of mucosal immunity

    Directory of Open Access Journals (Sweden)

    David Bernardo

    2013-06-01

    Full Text Available Dendritic cells are the most potent, professional antigen-presenting cells in the body; following antigen presentation they control the type (proinflammatory/regulatory of immune response that will take place, as well as its location. Given their high plasticity and maturation ability in response to local danger signals derived from innate immunity, dendritic cells are key actors in the connection between innate immunity and adaptive immunity responses. In the gut dendritic cells control immune tolerance mechanisms against food and/or commensal flora antigens, and are also capable of initiating an active immune response in the presence of invading pathogens. Dendritic cells are thus highly efficient in controlling the delicate balance between tolerance and immunity in an environment so rich in antigens as the gut, and any factor involving these cells may impact their function, ultimately leading to the development of bowel conditions such as celiac disease or inflammatory bowel disease. In this review we shall summarize our understanding of human intestinal dendritic cells, their ability to express and induce migration markers, the various environmental factors modulating their properties, their subsets in the gut, and the problems entailed by their study, including identification strategies, differences between humans and murine models, and phenotypical variations along the gastrointestinal tract.

  17. Human intestinal dendritic cells as controllers of mucosal immunity.

    Science.gov (United States)

    Bernardo, David

    2013-01-01

    Dendritic cells are the most potent, professional antigen-presenting cells in the body; following antigen presentation they control the type (proinflammatory/regulatory) of immune response that will take place, as well as its location. Given their high plasticity and maturation ability in response to local danger signals derived from innate immunity, dendritic cells are key actors in the connection between innate immunity and adaptive immunity responses. In the gut dendritic cells control immune tolerance mechanisms against food and/or commensal flora antigens, and are also capable of initiating an active immune response in the presence of invading pathogens. Dendritic cells are thus highly efficient in controlling the delicate balance between tolerance and immunity in an environment so rich in antigens as the gut, and any factor involving these cells may impact their function, ultimately leading to the development of bowel conditions such as celiac disease or inflammatory bowel disease. In this review we shall summarize our understanding of human intestinal dendritic cells, their ability to express and induce migration markers, the various environmental factors modulating their properties, their subsets in the gut, and the problems entailed by their study, including identification strategies, differences between humans and murine models, and phenotypical variations along the gastrointestinal tract.

  18. Single cell transcriptional analysis reveals novel innate immune cell types

    Directory of Open Access Journals (Sweden)

    Linda E. Kippner

    2014-06-01

    Full Text Available Single-cell analysis has the potential to provide us with a host of new knowledge about biological systems, but it comes with the challenge of correctly interpreting the biological information. While emerging techniques have made it possible to measure inter-cellular variability at the transcriptome level, no consensus yet exists on the most appropriate method of data analysis of such single cell data. Methods for analysis of transcriptional data at the population level are well established but are not well suited to single cell analysis due to their dependence on population averages. In order to address this question, we have systematically tested combinations of methods for primary data analysis on single cell transcription data generated from two types of primary immune cells, neutrophils and T lymphocytes. Cells were obtained from healthy individuals, and single cell transcript expression data was obtained by a combination of single cell sorting and nanoscale quantitative real time PCR (qRT-PCR for markers of cell type, intracellular signaling, and immune functionality. Gene expression analysis was focused on hierarchical clustering to determine the existence of cellular subgroups within the populations. Nine combinations of criteria for data exclusion and normalization were tested and evaluated. Bimodality in gene expression indicated the presence of cellular subgroups which were also revealed by data clustering. We observed evidence for two clearly defined cellular subtypes in the neutrophil populations and at least two in the T lymphocyte populations. When normalizing the data by different methods, we observed varying outcomes with corresponding interpretations of the biological characteristics of the cell populations. Normalization of the data by linear standardization taking into account technical effects such as plate effects, resulted in interpretations that most closely matched biological expectations. Single cell transcription

  19. Combination Effect of Regulatory T-Cell Depletion and Ionizing Radiation in Mouse Models of Lung and Colon Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Son, Cheol-Hun [Dongnam Institute of Radiological and Medical Sciences, Busan (Korea, Republic of); Department of Biochemistry, Pusan National University School of Medicine, Yangsan (Korea, Republic of); Bae, Jae-Ho [Department of Biochemistry, Pusan National University School of Medicine, Yangsan (Korea, Republic of); Shin, Dong-Yeok; Lee, Hong-Rae; Jo, Wol-Soon; Yang, Kwangmo [Dongnam Institute of Radiological and Medical Sciences, Busan (Korea, Republic of); Park, You-Soo, E-mail: biotek01@hanmail.net [Dongnam Institute of Radiological and Medical Sciences, Busan (Korea, Republic of)

    2015-06-01

    Purpose: To investigate the potential of low-dose cyclophosphamide (LD-CTX) and anti-CD25 antibody to prevent activation of regulatory T cells (Tregs) during radiation therapy. Methods and Materials: We used LD-CTX and anti-CD25 monoclonal antibody as a means to inhibit Tregs and improve the therapeutic effect of radiation in a mouse model of lung and colon cancer. Mice were irradiated on the tumor mass of the right leg and treated with LD-CTX and anti-CD25 antibody once per week for 3 weeks. Results: Combined treatment of LD-CTX or anti-CD25 antibody with radiation significantly decreased Tregs in the spleen and tumor compared with control and irradiation only in both lung and colon cancer. Combinatorial treatments resulted in a significant increase in the effector T cells, longer survival rate, and suppressed irradiated and distal nonirradiated tumor growth. Specifically, the combinatorial treatment of LD-CTX with radiation resulted in outstanding regression of local and distant tumors in colon cancer, and almost all mice in this group survived until the end of the study. Conclusions: Our results suggest that Treg depletion strategies may enhance radiation-mediated antitumor immunity and further improve outcomes after radiation therapy.

  20. Combination Effect of Regulatory T-Cell Depletion and Ionizing Radiation in Mouse Models of Lung and Colon Cancer

    International Nuclear Information System (INIS)

    Purpose: To investigate the potential of low-dose cyclophosphamide (LD-CTX) and anti-CD25 antibody to prevent activation of regulatory T cells (Tregs) during radiation therapy. Methods and Materials: We used LD-CTX and anti-CD25 monoclonal antibody as a means to inhibit Tregs and improve the therapeutic effect of radiation in a mouse model of lung and colon cancer. Mice were irradiated on the tumor mass of the right leg and treated with LD-CTX and anti-CD25 antibody once per week for 3 weeks. Results: Combined treatment of LD-CTX or anti-CD25 antibody with radiation significantly decreased Tregs in the spleen and tumor compared with control and irradiation only in both lung and colon cancer. Combinatorial treatments resulted in a significant increase in the effector T cells, longer survival rate, and suppressed irradiated and distal nonirradiated tumor growth. Specifically, the combinatorial treatment of LD-CTX with radiation resulted in outstanding regression of local and distant tumors in colon cancer, and almost all mice in this group survived until the end of the study. Conclusions: Our results suggest that Treg depletion strategies may enhance radiation-mediated antitumor immunity and further improve outcomes after radiation therapy

  1. Syntaxin and VAMP association with lipid rafts depends on cholesterol depletion in capacitating sperm cells.

    Science.gov (United States)

    Tsai, Pei-Shiue; De Vries, Klaas J; De Boer-Brouwer, Mieke; Garcia-Gil, Nuria; Van Gestel, Renske A; Colenbrander, Ben; Gadella, Bart M; Van Haeften, Theo

    2007-01-01

    Sperm cells represent a special exocytotic system since mature sperm cells contain only one large secretory vesicle, the acrosome, which fuses with the overlying plasma membrane during the fertilization process. Acrosomal exocytosis is believed to be regulated by activation of SNARE proteins. In this paper, we identified specific members of the SNARE protein family, i.e., the t-SNAREs syntaxin1 and 2, and the v-SNARE VAMP, present in boar sperm cells. Both syntaxins were predominantly found in the plasma membrane whereas v-SNAREs are mainly located in the outer acrosomal membrane of these cells. Under non-capacitating conditions both syntaxins and VAMP are scattered in well-defined punctate structures over the entire sperm head. Bicarbonate-induced in vitro activation in the presence of BSA causes a relocalization of these SNAREs to a more homogeneous distribution restricted to the apical ridge area of the sperm head, exactly matching the site of sperm zona binding and subsequent induced acrosomal exocytosis. This redistribution of syntaxin and VAMP depends on cholesterol depletion and closely resembles the previously reported redistribution of lipid raft marker proteins. Detergent-resistant membrane isolation and subsequent analysis shows that a significant proportion of syntaxin emerges in the detergent-resistant membrane (raft) fraction under such conditions, which is not the case under those conditions where cholesterol depletion is blocked. The v-SNARE VAMP displays a similar cholesterol depletion-dependent lateral and raft redistribution. Taken together, our results indicate that redistribution of syntaxin and VAMP during capacitation depends on association of these SNAREs with lipid rafts and that such a SNARE-raft association may be essential for spatial control of exocytosis and/or regulation of SNARE functioning.

  2. Kicking off adaptive immunity: the discovery of dendritic cells

    OpenAIRE

    Katsnelson, Alla

    2006-01-01

    In 1973, Ralph Steinman and Zanvil Cohn discovered an unusual looking population of cells with an unprecedented ability to activate naive T cells. Dubbed “dendritic cells,” these cells are now known as the primary instigators of adaptive immunity.

  3. Hybrid tandem solar cells with depleted-heterojunction quantum dot and polymer bulk heterojunction subcells

    KAUST Repository

    Kim, Taesoo

    2015-10-01

    We investigate hybrid tandem solar cells that rely on the combination of solution-processed depleted-heterojunction colloidal quantum dot (CQD) and bulk heterojunction polymer:fullerene subcells. The hybrid tandem solar cell is monolithically integrated and electrically connected in series with a suitable p-n recombination layer that includes metal oxides and a conjugated polyelectrolyte. We discuss the monolithic integration of the subcells, taking into account solvent interactions with underlayers and associated constraints on the tandem architecture, and show that an adequate device configuration consists of a low bandgap CQD bottom cell and a high bandgap polymer:fullerene top cell. Once we optimize the recombination layer and individual subcells, the hybrid tandem device reaches a VOC of 1.3V, approaching the sum of the individual subcell voltages. An impressive fill factor of 70% is achieved, further confirming that the subcells are efficiently connected via an appropriate recombination layer. © 2015.

  4. The depletion of interleukin-8 causes cell cycle arrest and increases the efficacy of docetaxel in breast cancer cells.

    Science.gov (United States)

    Shao, Nan; Chen, Liu-Hua; Ye, Run-Yi; Lin, Ying; Wang, Shen-Ming

    2013-02-15

    IL-8 is a multi-functional pro-inflammatory chemokine, which is highly expressed in cancers, such as ER-negative breast cancer. The present study demonstrates the pervasive role of IL-8 in the malignant progression of ER-negative breast cancer. IL-8 siRNA inhibited proliferation and delayed the G1 to S cell cycle progression in MDA-MB-231 and BT549 cells. IL-8 silencing resulted in the upregulation of the CDK inhibitor p27, the downregulation of cyclin D1, and the reduction of phosphorylated-Akt and NF-κB activities. IL-8 depletion also increased the chemosensitivity to docetaxel. These results indicate a role for IL-8 in promoting tumor cell survival and resistance to docetaxel and highlight the potential therapeutic significance of IL-8 depletion in ER-negative breast cancer patients.

  5. Retinoic Acid as a Modulator of T Cell Immunity.

    Science.gov (United States)

    Bono, Maria Rosa; Tejon, Gabriela; Flores-Santibañez, Felipe; Fernandez, Dominique; Rosemblatt, Mario; Sauma, Daniela

    2016-01-01

    Vitamin A, a generic designation for an array of organic molecules that includes retinal, retinol and retinoic acid, is an essential nutrient needed in a wide array of aspects including the proper functioning of the visual system, maintenance of cell function and differentiation, epithelial surface integrity, erythrocyte production, reproduction, and normal immune function. Vitamin A deficiency is one of the most common micronutrient deficiencies worldwide and is associated with defects in adaptive immunity. Reports from epidemiological studies, clinical trials and experimental studies have clearly demonstrated that vitamin A plays a central role in immunity and that its deficiency is the cause of broad immune alterations including decreased humoral and cellular responses, inadequate immune regulation, weak response to vaccines and poor lymphoid organ development. In this review, we will examine the role of vitamin A in immunity and focus on several aspects of T cell biology such as T helper cell differentiation, function and homing, as well as lymphoid organ development. Further, we will provide an overview of the effects of vitamin A deficiency in the adaptive immune responses and how retinoic acid, through its effect on T cells can fine-tune the balance between tolerance and immunity. PMID:27304965

  6. Levels of immune cells in transcendental meditation practitioners

    Directory of Open Access Journals (Sweden)

    Jose R Infante

    2014-01-01

    Conclusions: The technique of meditation studied seems to have a significant effect on immune cells, manifesting in the different circulating levels of lymphocyte subsets analyzed. The significant effect of TM on the neuroendocrine axis and its relationship with the immune system may partly explain our results.

  7. [Multipotent mesenchymal stromal and immune cells interaction: reciprocal effects].

    Science.gov (United States)

    Andreeva, E R; Buravkova, L B

    2012-12-01

    Adult multipotent mesenchymal stromal cells (MMSCs) are considered now as one of the key players in physiological and pathological tissue remodeling. Clarification of the mechanisms that mediate MMSC functions, is one of the most intriguing issues in modern cell physiology. Present Review summarizes current understanding of the MMSC effects on different types of immune cells. The realization of MMSC immunomodulatory capacity is considered as a contribution of direct cell-to-cell contacts, soluble mediators and of local microenvironmental factors, the most important of which is the partial pressure of oxygen. MMSCs and immune cells interaction is discussed in the terms of reciprocal effects, modifying properties of all "partner cells". Special attention is paid to the influence of immune cells on the MMSCs. "Immunosuppressive" phenomenon of MMSCs is considered as the integral part of the "response to injury" mechanism. PMID:23461191

  8. Stem Cell-Derived Extracellular Vesicles and Immune-Modulation.

    Science.gov (United States)

    Burrello, Jacopo; Monticone, Silvia; Gai, Chiara; Gomez, Yonathan; Kholia, Sharad; Camussi, Giovanni

    2016-01-01

    Extra-cellular vesicles (EVs) are bilayer membrane structures enriched with proteins, nucleic acids, and other active molecules and have been implicated in many physiological and pathological processes over the past decade. Recently, evidence suggests EVs to play a more dichotomic role in the regulation of the immune system, whereby an immune response may be enhanced or supressed by EVs depending on their cell of origin and its functional state. EVs derived from antigen (Ag)-presenting cells for instance, have been involved in both innate and acquired (or adaptive) immune responses, as Ag carriers or presenters, or as vehicles for delivering active signaling molecules. On the other hand, tumor and stem cell derived EVs have been identified to exert an inhibitory effect on immune responses by carrying immuno-modulatory effectors, such as transcriptional factors, non-coding RNA (Species), and cytokines. In addition, stem cell-derived EVs have also been reported to impair dendritic cell maturation and to regulate the activation, differentiation, and proliferation of B cells. They have been shown to control natural killer cell activity and to suppress the innate immune response (IIR). Studies reporting the role of EVs on T lymphocyte modulation are controversial. Discrepancy in literature may be due to stem cell culture conditions, methods of EV purification, EV molecular content, and functional state of both parental and target cells. However, mesenchymal stem cell-derived EVs were shown to play a more suppressive role by shifting T cells from an activated to a T regulatory phenotype. In this review, we will discuss how stem cell-derived EVs may contribute toward the modulation of the immune response. Collectively, stem cell-derived EVs mainly exhibit an inhibitory effect on the immune system. PMID:27597941

  9. GSH depletion enhances adenoviral bax-induced apoptosis in lung cancer cells.

    Science.gov (United States)

    Honda, Tsuyoshi; Coppola, Simona; Ghibelli, Lina; Cho, Song H; Kagawa, Shunsuke; Spurgers, Kevin B; Brisbay, Shawn M; Roth, Jack A; Meyn, Raymond E; Fang, Bingliang; McDonnell, Timothy J

    2004-04-01

    The utility of dominant acting proapoptotic molecules to induce cell death in cancer cells is being evaluated in preclinical studies and clinical trials. We recently developed a binary adenoviral expression system to enable the efficient gene transfer of Bax and other proapoptotic molecules. Using this system, overexpression of Bax protein in four non-small-cell lung cancer (NSCLC) cell lines, H1299, A549, H226 and H322, was evaluated. The H322 line exhibited significant resistance to Bax-induced cell death compared to the other cell lines. H322 cells had the highest level of glutathione (GSH). GSH levels were significantly decreased following buthionine sulfoximine treatment and this coincided with enhanced apoptosis induction by Ad-Bax in H322 cells. GSH depletion enhanced Bax protein translocation to mitochondrial membranes. These findings suggest that the redox status may be a determinant of Bax-mediated cell death and that manipulation of intracellular thiols may sensitize cells to apoptosis by facilitating Bax insertion into mitochondrial membranes. PMID:15002033

  10. Radiation response of drug-resistant variants of a human breast cancer cell line: The effect of glutathione depletion

    International Nuclear Information System (INIS)

    Two drug-resistant variants of the human breast cancer cell line MCF-7 have been shown previously to exhibit radiation resistance associated with an increase in the size of the shoulder on the radiation survival curve. In the present study, glutathione (GSH) depletion was achieved by exposure of cells to buthionine sulfoximine (BSO) with, in some cases, additional treatment with dimethyl fumarate. Levels of GSH in the adriamycin-resistant subline MCF-7 ADRR are initially lower than in the other two sublines and are depleted to a greater extent by exposure to BSO. Wild-type MCF-7 cells are not sensitized by GSH depletion when irradiated under aerated conditions but are sensitized under hypoxic conditions to an extent which is related to the level of GSH depletion. In contrast both the drug-resistant sublines (MCF-7 ADRR and the melphalan-resistant line MCF-7 MLNR) are radiosensitized by GSH depletion under both aerated and hypoxic conditions. It is hypothesized that in the case of the MCF-7 ADRR cell line, which expresses high levels of the GSH-associated redox enzyme systems, GSH-S-transferase and GSH-peroxidase (GSH-Px), radiosensitization results when GSH-Px is inhibited in GSH-depleted cells. The reasons for radiosensitization of aerated MCF-7 MLNR cells cannot be explained on this basis, however, and other factors are being examined

  11. Self-assembled, nanowire network electrodes for depleted bulk heterojunction solar cells

    KAUST Repository

    Lan, Xinzheng

    2013-01-06

    Herein, a solution-processed, bottom-up-fabricated, nanowire network electrode is developed. This electrode features a ZnO template which is converted into locally connected, infiltratable, TiO2 nanowires. This new electrode is used to build a depleted bulk heterojunction solar cell employing hybrid-passivated colloidal quantum dots. The new electrode allows the application of a thicker, and thus more light-absorbing, colloidal quantum dot active layer, from which charge extraction of an efficiency comparable to that obtained from a thinner, planar device could be obtained. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Myoferlin depletion in breast cancer cells promotes mesenchymal to epithelial shape change and stalls invasion.

    Directory of Open Access Journals (Sweden)

    Ruth Li

    Full Text Available Myoferlin (MYOF is a mammalian ferlin protein with homology to ancestral Fer-1, a nematode protein that regulates spermatic membrane fusion, which underlies the amoeboid-like movements of its sperm. Studies in muscle and endothelial cells have reported on the role of myoferlin in membrane repair, endocytosis, myoblast fusion, and the proper expression of various plasma membrane receptors. In this study, using an in vitro human breast cancer cell model, we demonstrate that myoferlin is abundantly expressed in invasive breast tumor cells. Depletion of MYOF using lentiviral-driven shRNA expression revealed that MDA-MB-231 cells reverted to an epithelial morphology, suggesting at least some features of mesenchymal to epithelial transition (MET. These observations were confirmed by the down-regulation of some mesenchymal cell markers (e.g., fibronectin and vimentin and coordinate up-regulation of the E-cadherin epithelial marker. Cell invasion assays using Boyden chambers showed that loss of MYOF led to a significant diminution in invasion through Matrigel or type I collagen, while cell migration was unaffected. PCR array and screening of serum-free culture supernatants from shRNA(MYOF transduced MDA-MB-231 cells indicated a significant reduction in the steady-state levels of several matrix metalloproteinases. These data when considered in toto suggest a novel role of MYOF in breast tumor cell invasion and a potential reversion to an epithelial phenotype upon loss of MYOF.

  13. Maintenance of immune homeostasis through ILC/T cell interactions

    Directory of Open Access Journals (Sweden)

    Nicole evon Burg

    2015-08-01

    Full Text Available Innate lymphoid cells (ILCs have emerged as a new family of immune cells with crucial functions in innate and adaptive immunity. ILC subsets mirror the cytokine and transcriptional profile of CD4+ T helper (TH cell subsets. Hence, group 1 (ILC1, group 2 (ILC2 and group 3 (ILC3 ILCs can be distinguished by the production of TH1, TH2, and TH17-type cytokines, respectively. Cytokine release by ILCs not only shapes early innate immunity, but can also orchestrate TH immune responses to microbial or allergen exposure. Recent studies have identified an unexpected effector function of ILCs as antigen presenting cells (APCs. Both ILC2s and ILC3s are able to process and present foreign antigens (Ags via major histocompatibility complex (MHC class II, and to induce cognate CD4+ T cell responses. In addition, Ag-stimulated T cells promote ILC activation and effector functions indicating a reciprocal interaction between the adaptive and innate immune system. A fundamental puzzle in ILC function is how ILC/T cell interactions promote host protection and prevent autoimmune diseases. Furthermore, the way in which microenvironmental and inflammatory signals determine the outcome of ILC/T cell immune responses in various tissues is not yet understood. This review focuses on recent advances in understanding the mechanisms that coordinate the collaboration between ILCs and T cells under homeostatic and inflammatory conditions. We also discuss the potential roles of T cells and other immune cells to regulate ILC functions and to maintain homeostasis in mucosal tissues.

  14. Early Depletion of Primordial Germ Cells in Zebrafish Promotes Testis Formation

    Directory of Open Access Journals (Sweden)

    Keh-Weei Tzung

    2015-01-01

    Full Text Available As complete absence of germ cells leads to sterile males in zebrafish, we explored the relationship between primordial germ cell (PGC number and sexual development. Our results revealed dimorphic proliferation of PGCs in the early zebrafish larvae, marking the beginning of sexual differentiation. We applied morpholino-based gene knockdown and cell transplantation strategies to demonstrate that a threshold number of PGCs is required for the stability of ovarian fate. Using histology and transcriptomic analyses, we determined that zebrafish gonads are in a meiotic ovarian stage at 14 days postfertilization and identified signaling pathways supporting meiotic oocyte differentiation and eventual female fate. The development of PGC-depleted gonads appears to be restrained and delayed, suggesting that PGC number may directly regulate the variability and length of gonadal transformation and testicular differentiation in zebrafish. We propose that gonadal transformation may function as a developmental buffering mechanism to ensure the reproductive outcome.

  15. Recruitment of activation receptors at inhibitory NK cell immune synapses.

    Directory of Open Access Journals (Sweden)

    Nicolas Schleinitz

    Full Text Available Natural killer (NK cell activation receptors accumulate by an actin-dependent process at cytotoxic immune synapses where they provide synergistic signals that trigger NK cell effector functions. In contrast, NK cell inhibitory receptors, including members of the MHC class I-specific killer cell Ig-like receptor (KIR family, accumulate at inhibitory immune synapses, block actin dynamics, and prevent actin-dependent phosphorylation of activation receptors. Therefore, one would predict inhibition of actin-dependent accumulation of activation receptors when inhibitory receptors are engaged. By confocal imaging of primary human NK cells in contact with target cells expressing physiological ligands of NK cell receptors, we show here that this prediction is incorrect. Target cells included a human cell line and transfected Drosophila insect cells that expressed ligands of NK cell activation receptors in combination with an MHC class I ligand of inhibitory KIR. The two NK cell activation receptors CD2 and 2B4 accumulated and co-localized with KIR at inhibitory immune synapses. In fact, KIR promoted CD2 and 2B4 clustering, as CD2 and 2B4 accumulated more efficiently at inhibitory synapses. In contrast, accumulation of KIR and of activation receptors at inhibitory synapses correlated with reduced density of the integrin LFA-1. These results imply that inhibitory KIR does not prevent CD2 and 2B4 signaling by blocking their accumulation at NK cell immune synapses, but by blocking their ability to signal within inhibitory synapses.

  16. Defective cell mediated immunity in sarcoidosis: effect of interleukin-2.

    OpenAIRE

    Lyons, D J; Gao, L.; Mitchell, E B; Mitchell, D. N.

    1988-01-01

    Interleukin-2 has been reported to enhance the immune response in diseases characterised by defective cell mediated immunity. The effect of exogenous recombinant interleukin-2 was studied on the proliferative and cytotoxic responses of peripheral blood mononuclear cells from 39 patients with sarcoidosis and 14 healthy control subjects. The proliferative response to purified protein derivative was smaller in patients than in control subjects (p less than 0.001) whereas the response to 80 U int...

  17. Human immune cell targeting of protein nanoparticles - caveospheres.

    Science.gov (United States)

    Glass, Joshua J; Yuen, Daniel; Rae, James; Johnston, Angus P R; Parton, Robert G; Kent, Stephen J; De Rose, Robert

    2016-04-14

    Nanotechnology has the power to transform vaccine and drug delivery through protection of payloads from both metabolism and off-target effects, while facilitating specific delivery of cargo to immune cells. However, evaluation of immune cell nanoparticle targeting is conventionally restricted to monocultured cell line models. We generated human caveolin-1 nanoparticles, termed caveospheres, which were efficiently functionalized with monoclonal antibodies. Using this platform, we investigated CD4+ T cell and CD20+ B cell targeting within physiological mixtures of primary human blood immune cells using flow cytometry, imaging flow cytometry and confocal microscopy. Antibody-functionalization enhanced caveosphere binding to targeted immune cells (6.6 to 43.9-fold) within mixed populations and in the presence of protein-containing fluids. Moreover, targeting caveospheres to CCR5 enabled caveosphere internalization by non-phagocytic CD4+ T cells-an important therapeutic target for HIV treatment. This efficient and flexible system of immune cell-targeted caveosphere nanoparticles holds promise for the development of advanced immunotherapeutics and vaccines. PMID:27031090

  18. Human immune cell targeting of protein nanoparticles - caveospheres

    Science.gov (United States)

    Glass, Joshua J.; Yuen, Daniel; Rae, James; Johnston, Angus P. R.; Parton, Robert G.; Kent, Stephen J.; de Rose, Robert

    2016-04-01

    Nanotechnology has the power to transform vaccine and drug delivery through protection of payloads from both metabolism and off-target effects, while facilitating specific delivery of cargo to immune cells. However, evaluation of immune cell nanoparticle targeting is conventionally restricted to monocultured cell line models. We generated human caveolin-1 nanoparticles, termed caveospheres, which were efficiently functionalized with monoclonal antibodies. Using this platform, we investigated CD4+ T cell and CD20+ B cell targeting within physiological mixtures of primary human blood immune cells using flow cytometry, imaging flow cytometry and confocal microscopy. Antibody-functionalization enhanced caveosphere binding to targeted immune cells (6.6 to 43.9-fold) within mixed populations and in the presence of protein-containing fluids. Moreover, targeting caveospheres to CCR5 enabled caveosphere internalization by non-phagocytic CD4+ T cells--an important therapeutic target for HIV treatment. This efficient and flexible system of immune cell-targeted caveosphere nanoparticles holds promise for the development of advanced immunotherapeutics and vaccines.

  19. Oval cell response is attenuated by depletion of liver resident macrophages in the 2-AAF/partial hepatectomy rat.

    Directory of Open Access Journals (Sweden)

    Shuai Xiang

    Full Text Available BACKGROUND/AIMS: Macrophages are known to play an important role in hepatocyte mediated liver regeneration by secreting inflammatory mediators. However, there is little information available on the role of resident macrophages in oval cell mediated liver regeneration. In the present study we aimed to investigate the role of macrophages in oval cell expansion induced by 2-acetylaminofluorene/partial hepatectomy (2-AAF/PH in rats. METHODOLOGY/PRINCIPAL FINDINGS: We depleted macrophages in the liver of 2-AAF/PH treated rats by injecting liposome encapsulated clodronate 48 hours before PH. Regeneration of remnant liver mass, as well as proliferation and differentiation of oval cells were measured. We found that macrophage-depleted rats suffered higher mortality and liver transaminase levels. We also showed that depletion of macrophages yielded a significant decrease of EPCAM and PCK positive oval cells in immunohistochemical stained liver sections 9 days after PH. Meanwhile, oval cell differentiation was also attenuated as a result of macrophage depletion, as large foci of small basophilic hepatocytes were observed by day 9 following hepatectomy in control rats whereas they were almost absent in macrophage depleted rats. Accordingly, real-time polymerase chain reaction analysis showed lower expression of albumin mRNA in macrophage depleted livers. Then we assessed whether macrophage depletion may affect hepatic production of stimulating cytokines for liver regeneration. We showed that macrophage-depletion significantly inhibited hepatic expression of tumor necrosis factor-α and interleukin-6, along with a lack of signal transducer and activator of transcription 3 phosphorylation during the early period following hepatectomy. CONCLUSIONS: These data indicate that macrophages play an important role in oval cell mediated liver regeneration in the 2-AAF/PH model.

  20. Acute dyskerin depletion triggers cellular senescence and renders osteosarcoma cells resistant to genotoxic stress-induced apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Ping; Mobasher, Maral E.; Alawi, Faizan, E-mail: falawi@upenn.edu

    2014-04-18

    Highlights: • Dyskerin depletion triggers cellular senescence in U2OS osteosarcoma cells. • Dyskerin-depleted cells are resistant to apoptosis induced by genotoxic stress. • Chromatin relaxation sensitizes dyskerin-depleted cells to apoptosis. - Abstract: Dyskerin is a conserved, nucleolar RNA-binding protein implicated in an increasing array of fundamental cellular processes. Germline mutation in the dyskerin gene (DKC1) is the cause of X-linked dyskeratosis congenita (DC). Conversely, wild-type dyskerin is overexpressed in sporadic cancers, and high-levels may be associated with poor prognosis. It was previously reported that acute loss of dyskerin function via siRNA-mediated depletion slowed the proliferation of transformed cell lines. However, the mechanisms remained unclear. Using human U2OS osteosarcoma cells, we show that siRNA-mediated dyskerin depletion induced cellular senescence as evidenced by proliferative arrest, senescence-associated heterochromatinization and a senescence-associated molecular profile. Senescence can render cells resistant to apoptosis. Conversely, chromatin relaxation can reverse the repressive effects of senescence-associated heterochromatinization on apoptosis. To this end, genotoxic stress-induced apoptosis was suppressed in dyskerin-depleted cells. In contrast, agents that induce chromatin relaxation, including histone deacetylase inhibitors and the DNA intercalator chloroquine, sensitized dyskerin-depleted cells to apoptosis. Dyskerin is a core component of the telomerase complex and plays an important role in telomere homeostasis. Defective telomere maintenance resulting in premature senescence is thought to primarily underlie the pathogenesis of X-linked DC. Since U2OS cells are telomerase-negative, this leads us to conclude that loss of dyskerin function can also induce cellular senescence via mechanisms independent of telomere shortening.

  1. Balancing immune protection and immune pathology by CD8+ T cell responses to influenza infection

    Directory of Open Access Journals (Sweden)

    Susu eDuan

    2016-02-01

    Full Text Available Influenza A virus (IAV is a significant human pathogen causing annual epidemics and periodic pandemics. CD8+ cytotoxic T lymphocyte (CTL-mediated immunity contributes to clearance of virus-infected cells; CTL immunity targeting the conserved internal proteins of IAVs is a key protection mechanism when neutralizing antibodies are absent during heterosubtypic IAV infection. However, CTL infiltration into the airways, their cytotoxicity, and the effects of produced pro-inflammatory cytokines can cause severe lung tissue injury, thereby contributing to immunopathology. Studies have discovered complicated and exquisite stimulatory and inhibitory mechanisms that regulate CTL magnitude and effector activities during IAV infection. Here, we review the state of knowledge on the roles of IAV-specific CTLs in immune protection and immunopathology during IAV infection in animal models, highlighting the key findings of various requirements and constraints regulating the balance of immune protection and pathology involved in CTL immunity. We also discuss the evidence of cross-reactive CTL immunity as a positive correlate of cross-subtype protection during secondary IAV infection in both animal and human studies. We argue that the effects of CTL immunity on protection and immunopathology depend on multiple layers of host and viral factors, including complex host mechanisms to regulate CTL magnitude and effector activity, the pathogenic nature of the IAV, the innate response milieu, and the host historical immune context of influenza infection. Future efforts are needed to further understand these key host and viral factors, especially to differentiate those that constrain optimally effective CTL anti-viral immunity from those necessary to restrain CTL-mediated nonspecific immunopathology in the various contexts of IAV infection, in order to develop better vaccination and therapeutic strategies for modifying protective CTL immunity.

  2. Apoptosis in immune cells induced by fission fragment 147Pm

    Institute of Scientific and Technical Information of China (English)

    ZhuShou-Peng; ZhangLan-Sheng; 等

    1997-01-01

    Apoptosis in human acute lymphoblastic leukemia cell line Molt-4 cell and macrophage cell line Ana-1 cell could be induced by fission fragment 147Pm,The cumulative absorption dose of 147Pm in cultural cells through different periods were estimated.By using fluorescence microscopy and microautoradiographic tracing it can be found that Molt-4 and Anal-1 cells internally irradiated by 147Pm,displayed an obvious nuclear fragmentation and a marked phknosis in immune cell nucei,as well as DNA chain fragmentation and apoptotic bodies formation.The microautoradiographic study showed that 147Pm could infiltrate thourgh cell membrane and displayed membrane-seeking condensation in cells.At the same time.the membrane-bounded apoptotic bodies were observed.Experimental results in recent study provide evidence that Molt-4 and Ano-1 immune cells undergo apoptosis while internally irradiated with 147Pm.

  3. Effector Regulatory T Cells Reflect the Equilibrium between Antitumor Immunity and Autoimmunity in Adult T-cell Leukemia.

    Science.gov (United States)

    Ureshino, Hiroshi; Shindo, Takero; Nishikawa, Hiroyoshi; Watanabe, Nobukazu; Watanabe, Eri; Satoh, Natsuko; Kitaura, Kazutaka; Kitamura, Hiroaki; Doi, Kazuko; Nagase, Kotaro; Kimura, Hiromi; Samukawa, Makoto; Kusunoki, Susumu; Miyahara, Masaharu; Shin-I, Tadasu; Suzuki, Ryuji; Sakaguchi, Shimon; Kimura, Shinya

    2016-08-01

    The regulatory T cells (Treg) with the most potent immunosuppressive activity are the effector Tregs (eTreg) with a CD45RA(-)Foxp3(++)CCR4(+) phenotype. Adult T-cell leukemia (ATL) cells often share the Treg phenotype and also express CCR4. Although mogamulizumab, a monoclonal antibody to CCR4, shows marked antitumor effects against ATL and peripheral T-cell lymphoma, concerns have been raised that it may induce severe autoimmune immunopathology by depleting eTregs. Here, we present case reports for two patients with ATL who responded to mogamulizumab but developed a severe skin rash and autoimmune brainstem encephalitis. Deep sequencing of the T-cell receptor revealed that ATL cells and naturally occurring Tregs within the cell population with a Treg phenotype can be clearly distinguished according to CADM1 expression. The onset of skin rash and brainstem encephalitis was coincident with eTreg depletion from the peripheral blood, whereas ATL relapses were coincident with eTreg recovery. These results imply that eTreg numbers in the peripheral blood sensitively reflect the equilibrium between antitumor immunity and autoimmunity, and that mogamulizumab might suppress ATL until the eTreg population recovers. Close monitoring of eTreg numbers is crucial if we are to provide immunomodulatory treatments that target malignancy without severe adverse events. Cancer Immunol Res; 4(8); 644-9. ©2016 AACR. PMID:27215229

  4. Golgi enlargement in Arf-depleted yeast cells is due to altered dynamics of cisternal maturation

    Science.gov (United States)

    Bhave, Madhura; Papanikou, Effrosyni; Iyer, Prasanna; Pandya, Koushal; Jain, Bhawik Kumar; Ganguly, Abira; Sharma, Chandrakala; Pawar, Ketakee; Austin, Jotham; Day, Kasey J.; Rossanese, Olivia W.; Glick, Benjamin S.; Bhattacharyya, Dibyendu

    2014-01-01

    ABSTRACT Regulation of the size and abundance of membrane compartments is a fundamental cellular activity. In Saccharomyces cerevisiae, disruption of the ADP-ribosylation factor 1 (ARF1) gene yields larger and fewer Golgi cisternae by partially depleting the Arf GTPase. We observed a similar phenotype with a thermosensitive mutation in Nmt1, which myristoylates and activates Arf. Therefore, partial depletion of Arf is a convenient tool for dissecting mechanisms that regulate Golgi structure. We found that in arf1Δ cells, late Golgi structure is particularly abnormal, with the number of late Golgi cisternae being severely reduced. This effect can be explained by selective changes in cisternal maturation kinetics. The arf1Δ mutation causes early Golgi cisternae to mature more slowly and less frequently, but does not alter the maturation of late Golgi cisternae. These changes quantitatively explain why late Golgi cisternae are fewer in number and correspondingly larger. With a stacked Golgi, similar changes in maturation kinetics could be used by the cell to modulate the number of cisternae per stack. Thus, the rates of processes that transform a maturing compartment can determine compartmental size and copy number. PMID:24190882

  5. Tc17 Cells Mediate Vaccine Immunity against Lethal Fungal Pneumonia in Immune Deficient Hosts Lacking CD4+ T Cells

    OpenAIRE

    Som Gowda Nanjappa; Erika Heninger; Marcel Wüthrich; David Joseph Gasper; Bruce S Klein

    2012-01-01

    Vaccines may help reduce the growing incidence of fungal infections in immune-suppressed patients. We have found that, even in the absence of CD4(+) T-cell help, vaccine-induced CD8(+) T cells persist and confer resistance against Blastomyces dermatitidis and Histoplasma capsulatum. Type 1 cytokines contribute to that resistance, but they also are dispensable. Although the role of T helper 17 cells in immunity to fungi is debated, IL-17 producing CD8(+) T cells (Tc17 cells) have not been inve...

  6. Stress Hyperglycemia, Insulin Treatment, and Innate Immune Cells

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    Fangming Xiu

    2014-01-01

    Full Text Available Hyperglycemia (HG and insulin resistance are the hallmarks of a profoundly altered metabolism in critical illness resulting from the release of cortisol, catecholamines, and cytokines, as well as glucagon and growth hormone. Recent studies have proposed a fundamental role of the immune system towards the development of insulin resistance in traumatic patients. A comprehensive review of published literatures on the effects of hyperglycemia and insulin on innate immunity in critical illness was conducted. This review explored the interaction between the innate immune system and trauma-induced hypermetabolism, while providing greater insight into unraveling the relationship between innate immune cells and hyperglycemia. Critical illness substantially disturbs glucose metabolism resulting in a state of hyperglycemia. Alterations in glucose and insulin regulation affect the immune function of cellular components comprising the innate immunity system. Innate immune system dysfunction via hyperglycemia is associated with a higher morbidity and mortality in critical illness. Along with others, we hypothesize that reduction in morbidity and mortality observed in patients receiving insulin treatment is partially due to its effect on the attenuation of the immune response. However, there still remains substantial controversy regarding moderate versus intensive insulin treatment. Future studies need to determine the integrated effects of HG and insulin on the regulation of innate immunity in order to provide more effective insulin treatment regimen for these patients.

  7. In EXOG-depleted cardiomyocytes cell death is marked by a decreased mitochondrial reserve capacity of the electron transport chain.

    Science.gov (United States)

    Tigchelaar, Wardit; De Jong, Anne Margreet; van Gilst, Wiek H; De Boer, Rudolf A; Silljé, Herman H W

    2016-07-01

    Depletion of mitochondrial endo/exonuclease G-like (EXOG) in cultured neonatal cardiomyocytes stimulates mitochondrial oxygen consumption rate (OCR) and induces hypertrophy via reactive oxygen species (ROS). Here, we show that neurohormonal stress triggers cell death in endo/exonuclease G-like-depleted cells, and this is marked by a decrease in mitochondrial reserve capacity. Neurohormonal stimulation with phenylephrine (PE) did not have an additive effect on the hypertrophic response induced by endo/exonuclease G-like depletion. Interestingly, PE-induced atrial natriuretic peptide (ANP) gene expression was completely abolished in endo/exonuclease G-like-depleted cells, suggesting a reverse signaling function of endo/exonuclease G-like. Endo/exonuclease G-like depletion initially resulted in increased mitochondrial OCR, but this declined upon PE stimulation. In particular, the reserve capacity of the mitochondrial respiratory chain and maximal respiration were the first indicators of perturbations in mitochondrial respiration, and these marked the subsequent decline in mitochondrial function. Although pathological stimulation accelerated these processes, prolonged EXOG depletion also resulted in a decline in mitochondrial function. At early stages of endo/exonuclease G-like depletion, mitochondrial ROS production was increased, but this did not affect mitochondrial DNA (mtDNA) integrity. After prolonged depletion, ROS levels returned to control values, despite hyperpolarization of the mitochondrial membrane. The mitochondrial dysfunction finally resulted in cell death, which appears to be mainly a form of necrosis. In conclusion, endo/exonuclease G-like plays an essential role in cardiomyocyte physiology. Loss of endo/exonuclease G-like results in diminished adaptation to pathological stress. The decline in maximal respiration and reserve capacity is the first sign of mitochondrial dysfunction that determines subsequent cell death. PMID:27417117

  8. Tc17 cells mediate vaccine immunity against lethal fungal pneumonia in immune deficient hosts lacking CD4+ T cells.

    Directory of Open Access Journals (Sweden)

    Som Gowda Nanjappa

    Full Text Available Vaccines may help reduce the growing incidence of fungal infections in immune-suppressed patients. We have found that, even in the absence of CD4(+ T-cell help, vaccine-induced CD8(+ T cells persist and confer resistance against Blastomyces dermatitidis and Histoplasma capsulatum. Type 1 cytokines contribute to that resistance, but they also are dispensable. Although the role of T helper 17 cells in immunity to fungi is debated, IL-17 producing CD8(+ T cells (Tc17 cells have not been investigated. Here, we show that Tc17 cells are indispensable in antifungal vaccine immunity in hosts lacking CD4(+ T cells. Tc17 cells are induced upon vaccination, recruited to the lung on pulmonary infection, and act non-redundantly in mediating protection in a manner that requires neutrophils. Tc17 cells did not influence type I immunity, nor did the lack of IL-12 signaling augment Tc17 cells, indicating a distinct lineage and function. IL-6 was required for Tc17 differentiation and immunity, but IL-1R1 and Dectin-1 signaling was unexpectedly dispensable. Tc17 cells expressed surface CXCR3 and CCR6, but only the latter was essential in recruitment to the lung. Although IL-17 producing T cells are believed to be short-lived, effector Tc17 cells expressed low levels of KLRG1 and high levels of the transcription factor TCF-1, predicting their long-term survival and stem-cell like behavior. Our work has implications for designing vaccines against fungal infections in immune suppressed patients.

  9. Tc17 cells mediate vaccine immunity against lethal fungal pneumonia in immune deficient hosts lacking CD4+ T cells.

    Science.gov (United States)

    Nanjappa, Som Gowda; Heninger, Erika; Wüthrich, Marcel; Gasper, David Joseph; Klein, Bruce S

    2012-01-01

    Vaccines may help reduce the growing incidence of fungal infections in immune-suppressed patients. We have found that, even in the absence of CD4(+) T-cell help, vaccine-induced CD8(+) T cells persist and confer resistance against Blastomyces dermatitidis and Histoplasma capsulatum. Type 1 cytokines contribute to that resistance, but they also are dispensable. Although the role of T helper 17 cells in immunity to fungi is debated, IL-17 producing CD8(+) T cells (Tc17 cells) have not been investigated. Here, we show that Tc17 cells are indispensable in antifungal vaccine immunity in hosts lacking CD4(+) T cells. Tc17 cells are induced upon vaccination, recruited to the lung on pulmonary infection, and act non-redundantly in mediating protection in a manner that requires neutrophils. Tc17 cells did not influence type I immunity, nor did the lack of IL-12 signaling augment Tc17 cells, indicating a distinct lineage and function. IL-6 was required for Tc17 differentiation and immunity, but IL-1R1 and Dectin-1 signaling was unexpectedly dispensable. Tc17 cells expressed surface CXCR3 and CCR6, but only the latter was essential in recruitment to the lung. Although IL-17 producing T cells are believed to be short-lived, effector Tc17 cells expressed low levels of KLRG1 and high levels of the transcription factor TCF-1, predicting their long-term survival and stem-cell like behavior. Our work has implications for designing vaccines against fungal infections in immune suppressed patients.

  10. Exploitation of herpesvirus immune evasion strategies to modify the immunogenicity of human mesenchymal stem cell transplants.

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    Anabel S de la Garza-Rodea

    Full Text Available BACKGROUND: Mesenchymal stem cells (MSCs are multipotent cells residing in the connective tissue of many organs and holding great potential for tissue repair. In culture, human MSCs (hMSCs are capable of extensive proliferation without showing chromosomal aberrations. Large numbers of hMSCs can thus be acquired from small samples of easily obtainable tissues like fat and bone marrow. MSCs can contribute to regeneration indirectly by secretion of cytokines or directly by differentiation into specialized cell types. The latter mechanism requires their long-term acceptance by the recipient. Although MSCs do not elicit immune responses in vitro, animal studies have revealed that allogeneic and xenogeneic MSCs are rejected. METHODOLOGY/PRINCIPAL FINDINGS: We aim to overcome MSC immune rejection through permanent down-regulation of major histocompatibility complex (MHC class I proteins on the surface of these MHC class II-negative cells through the use of viral immune evasion proteins. Transduction of hMSCs with a retroviral vector encoding the human cytomegalovirus US11 protein resulted in strong inhibition of MHC class I surface expression. When transplanted into immunocompetent mice, persistence of the US11-expressing and HLA-ABC-negative hMSCs at levels resembling those found in immunodeficient (i.e., NOD/SCID mice could be attained provided that recipients' natural killer (NK cells were depleted prior to cell transplantation. CONCLUSIONS/SIGNIFICANCE: Our findings demonstrate the potential utility of herpesviral immunoevasins to prevent rejection of xenogeneic MSCs. The observation that down-regulation of MHC class I surface expression renders hMSCs vulnerable to NK cell recognition and cytolysis implies that multiple viral immune evasion proteins are likely required to make hMSCs non-immunogenic and thereby universally transplantable.

  11. Depletion of CD25+ cells during acute toxoplasmosis does not significantly increase mortality in Swiss OF1 mice

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    Haroon Akbar

    2012-03-01

    Full Text Available The interleukin (IL-2R alpha chain (CD25 is expressed on regulatory T cells (Treg, which constitute more than 85% of the CD25+ T cell population in a naïve mouse. CD25 is also expressed on effector T cells in mice suffering from an acute infection by the obligate intracellular protozoan parasite, Toxoplasma gondii. Lethal toxoplasmosis is accompanied by a significant loss of Treg in mice naturally susceptible to toxoplasmosis. The present study was done to explore the role of Treg cells using an anti-CD25 antibody-mediated depletion in mice naturally resistant to toxoplasmosis. Although a significant decrease in the percentage of Treg cells was observed following anti-CD25 monoclonal antibody injections, the depletion of CD25+ cells during acute toxoplasmosis did not significantly increase the mortality of Swiss OF1 mice and no significant difference was observed in the brain parasitic load between the mice in the depleted-infected and isotype-infected groups. We found no significant difference between the titres of total IgG in the sera of the mice from the two groups in the chronic phase. However, CD25+ cells depletion was followed by significantly higher levels of IL-12 in the serum of depleted mice than in that of mice injected with the isotype control antibody.

  12. Mice immunization with radioattenuated Paracoccidioides brasiliensis yeast cells: protective immunity induction evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Estefania M.N.; Andrade, Antero S.R. [Centro de Desenvolvimento da Tecnologia Nuclear CDTN/CNEN-MG, Belo Horizonte, MG (Brazil)]. E-mail: estefaniabio@yahoo.com.br; antero@cdtn.br; Reis, Bernardo S.; Goes, Alfredo M. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Bioquimica e Imunologia]. E-mail: brsgarbi@mono.icb.ufmg.br; goes@mono.icb.ufmg.br

    2007-07-01

    Paracoccidioides brasiliensis is the agent of paracoccidioidomycosis (PCM), a chronic systemic disease prevalent in Latin America. To date, there is no effective vaccine. The potential of gamma radiation for pathogens attenuation and vaccine development was explored in this work. In our laboratory was developed radioattenuated yeast cells of P. brasiliensis and the aim of this work was to evaluate the protection elicited by the immunization with this cells. To check the protector effect BALB/c mice were divided in two groups. The mice of group 1 were immunized once and those of group 2 twice, at two weeks intervals, using 10{sup 5} radioattenuated yeast cells. The mice were sacrificed 30 and 90 days after challenge. The removed organs were used for colony-forming units (CFUs) recover and histopathologic analysis. The gamma irradiated yeast loses its virulence since fails in producing infection in BALB/c mice. An efficient protection against highly infective forms of P. brasiliensis was developed in the group of mice immunized two times. The immunization was able to reduce the initial infection and elicited a long lasted protection. We concluded that the radioattenuated yeast cells are a valuable tool for the protective immunity study in the PCM and for vaccine research. (author)

  13. NKp46+ Innate Lymphoid Cells Dampen Vaginal CD8 T Cell Responses following Local Immunization with a Cholera Toxin-Based Vaccine.

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    Carmelo Luci

    Full Text Available Innate and adaptive immune cells work in concert to generate efficient protection at mucosal surface. Vaginal mucosa is an epithelial tissue that contains innate and adaptive immune effector cells. Our previous studies demonstrated that vaginal administration of Cholera toxin -based vaccines generate antigen-specific CD8 T cells through the stimulation of local dendritic cells (DC. Innate lymphoid cells (ILC are a group of lymphocytes localized in epithelial tissues that have important immune functions against pathogens and in tissue homeostasis. Their contribution to vaccine-induced mucosal T cell responses is an important issue for the design of protective vaccines. We report here that the vaginal mucosa contains a heterogeneous population of NKp46+ ILC that includes conventional NK cells and ILC1-like cells. We show that vaginal NKp46+ ILC dampen vaccine-induced CD8 T cell responses generated after local immunization. Indeed, in vivo depletion of NKp46+ ILC with anti-NK1.1 antibody or NKG2D blockade increases the magnitude of vaginal OVA-specific CD8 T cells. Furthermore, such treatments also increase the number of DC in the vagina. NKG2D ligands being expressed by vaginal DC but not by CD8 T cells, these results support that NKp46+ ILC limit mucosal CD8 T cell responses indirectly through the NKG2D-dependent elimination of vaginal DC. Our data reveal an unappreciated role of NKp46+ ILC in the regulation of mucosal CD8 T cell responses.

  14. NKp46+ Innate Lymphoid Cells Dampen Vaginal CD8 T Cell Responses following Local Immunization with a Cholera Toxin-Based Vaccine.

    Science.gov (United States)

    Luci, Carmelo; Bekri, Selma; Bihl, Franck; Pini, Jonathan; Bourdely, Pierre; Nouhen, Kelly; Malgogne, Angélique; Walzer, Thierry; Braud, Véronique M; Anjuère, Fabienne

    2015-01-01

    Innate and adaptive immune cells work in concert to generate efficient protection at mucosal surface. Vaginal mucosa is an epithelial tissue that contains innate and adaptive immune effector cells. Our previous studies demonstrated that vaginal administration of Cholera toxin -based vaccines generate antigen-specific CD8 T cells through the stimulation of local dendritic cells (DC). Innate lymphoid cells (ILC) are a group of lymphocytes localized in epithelial tissues that have important immune functions against pathogens and in tissue homeostasis. Their contribution to vaccine-induced mucosal T cell responses is an important issue for the design of protective vaccines. We report here that the vaginal mucosa contains a heterogeneous population of NKp46+ ILC that includes conventional NK cells and ILC1-like cells. We show that vaginal NKp46+ ILC dampen vaccine-induced CD8 T cell responses generated after local immunization. Indeed, in vivo depletion of NKp46+ ILC with anti-NK1.1 antibody or NKG2D blockade increases the magnitude of vaginal OVA-specific CD8 T cells. Furthermore, such treatments also increase the number of DC in the vagina. NKG2D ligands being expressed by vaginal DC but not by CD8 T cells, these results support that NKp46+ ILC limit mucosal CD8 T cell responses indirectly through the NKG2D-dependent elimination of vaginal DC. Our data reveal an unappreciated role of NKp46+ ILC in the regulation of mucosal CD8 T cell responses.

  15. Theophylline prevents NAD+ depletion via PARP-1 inhibition in human pulmonary epithelial cells

    International Nuclear Information System (INIS)

    Oxidative DNA damage, as occurs during exacerbations in chronic obstructive pulmonary disease (COPD), highly activates the nuclear enzyme poly(ADP-ribose)polymerase-1 (PARP-1). This can lead to cellular depletion of its substrate NAD+, resulting in an energy crisis and ultimately in cell death. Inhibition of PARP-1 results in preservation of the intracellular NAD+ pool, and of NAD+-dependent cellular processes. In this study, PARP-1 activation by hydrogen peroxide decreased intracellular NAD+ levels in human pulmonary epithelial cells, which was found to be prevented in a dose-dependent manner by theophylline, a widely used compound in the treatment of COPD. This enzyme inhibition by theophylline was confirmed in an ELISA using purified human PARP-1 and was found to be competitive by nature. These findings provide new mechanistic insights into the therapeutic effect of theophylline in oxidative stress-induced lung pathologies

  16. Ets Factors Regulate Neural Stem Cell Depletion and Gliogenesis in Ras Pathway Glioma.

    Science.gov (United States)

    Breunig, Joshua J; Levy, Rachelle; Antonuk, C Danielle; Molina, Jessica; Dutra-Clarke, Marina; Park, Hannah; Akhtar, Aslam Abbasi; Kim, Gi Bum; Hu, Xin; Bannykh, Serguei I; Verhaak, Roel G W; Danielpour, Moise

    2015-07-14

    As the list of putative driver mutations in glioma grows, we are just beginning to elucidate the effects of dysregulated developmental signaling pathways on the transformation of neural cells. We have employed a postnatal, mosaic, autochthonous glioma model that captures the first hours and days of gliomagenesis in more resolution than conventional genetically engineered mouse models of cancer. We provide evidence that disruption of the Nf1-Ras pathway in the ventricular zone at multiple signaling nodes uniformly results in rapid neural stem cell depletion, progenitor hyperproliferation, and gliogenic lineage restriction. Abolishing Ets subfamily activity, which is upregulated downstream of Ras, rescues these phenotypes and blocks glioma initiation. Thus, the Nf1-Ras-Ets axis might be one of the select molecular pathways that are perturbed for initiation and maintenance in glioma.

  17. Immune Monitoring Using mRNA-Transfected Dendritic Cells.

    Science.gov (United States)

    Borch, Troels Holz; Svane, Inge Marie; Met, Özcan

    2016-01-01

    Dendritic cells are known to be the most potent antigen presenting cell in the immune system and are used as cellular adjuvants in therapeutic anticancer vaccines using various tumor-associated antigens or their derivatives. One way of loading antigen into the dendritic cells is by mRNA electroporation, ensuring presentation of antigen through major histocompatibility complex I and potentially activating T cells, enabling them to kill the tumor cells. Despite extensive research in the field, only one dendritic cell-based vaccine has been approved. There is therefore a great need to elucidate and understand the immunological impact of dendritic cell vaccination in order to improve clinical benefit. In this chapter, we describe a method for performing immune monitoring using peripheral blood mononuclear cells and autologous dendritic cells transfected with tumor-associated antigen-encoding mRNA. PMID:27236804

  18. Thyroiditis in T cell-depleted rats. Influence of strain, radiation dose, adjuvants and antilymphocyte serum.

    Science.gov (United States)

    Penhale, W J; Farmer, A; Irvine, W J

    1975-09-01

    Strain differences in susceptibility to the development of thyroiditis following adult thymectomy and repeated sublethal X-irradiation (4 X 200 rad) were investigated in the rat. Marked strain variation was noted, with AUG and PVG/c rats having the highest incidence and severity of lesion (100 and 80% respectively) whilst CAM rats had a low incidence (9%). WAG and LIS rats occupied an intermediate position. The incidence of autoantibodies to thyroglobulin correlated closely with the strain incidence of thyroiditis (r = 0-87). Fractionation of the sera from thymectomized and irradiated rats by gel filtration chromatography indicated that the bulk of the antibodies to thyroglobulin were of the IgG class. Freund's complete adjuvant, but not lipopolysaccharide, enhanced the rate of development of thyroiditis in thymectomized rats given a shortened series of irradiations. It was not found possible to induce thyroiditis in thymectomized rats by substituting antilymphocyte serum for irradiation as a T cell-depleting agent, despite the fact that the treated rats had markedly reduced responses to phytohaemagglutinin. A combination of thymectomy, three doses of 200 rad, and a development period of 8 weeks were found to be the optimum conditions for induction of severe thyroiditis together with high antibody titres to thyroglobulin. These findings add support for the role of thymus-derived cells in the regulation of autoimmune responses and further suggest that thymectomy, combined with a series of sublethal irradiations, causes a selective depletion of those T cells specifically involved in the suppression of autoimmune reactivity to thyroid components, whilst leaving autoreactive helper T cells unimpaired.

  19. Dystroglycan Depletion Impairs Actin-Dependent Functions of Differentiated Kasumi-1 Cells

    Science.gov (United States)

    Escárcega-Tame, Marco Antonio; Martínez-Vieyra, Ivette; Alonso-Rangel, Lea; Cisneros, Bulmaro; Winder, Steve J.; Cerecedo, Doris

    2015-01-01

    Background Dystroglycan has recently been characterised in blood tissue cells, as part of the dystrophin glycoprotein complex involved in the differentiation process of neutrophils. Purpose In the present study we have investigated the role of dystroglycan in the human promyelocytic leukemic cell line Kasumi-1 differentiated to macrophage-like cells. Methods We characterised the pattern expression and subcellular distribution of dystroglycans in non-differentiated and differentiated Kasumi-1 cells. Results Our results demonstrated by WB and flow cytometer assays that during the differentiation process to macrophages, dystroglycans were down-regulated; these results were confirmed with qRT-PCR assays. Additionally, depletion of dystroglycan by RNAi resulted in altered morphology and reduced properties of differentiated Kasumi-1 cells, including morphology, migration and phagocytic activities although secretion of IL-1β and expression of markers of differentiation are not altered. Conclusion Our findings strongly implicate dystroglycan as a key membrane adhesion protein involved in actin-based structures during the differentiation process in Kasumi-1 cells. PMID:26630171

  20. Continuous-Wave Stimulated Emission Depletion Microscope for Imaging Actin Cytoskeleton in Fixed and Live Cells

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    Bhanu Neupane

    2015-09-01

    Full Text Available Stimulated emission depletion (STED microscopy provides a new opportunity to study fine sub-cellular structures and highly dynamic cellular processes, which are challenging to observe using conventional optical microscopy. Using actin as an example, we explored the feasibility of using a continuous wave (CW-STED microscope to study the fine structure and dynamics in fixed and live cells. Actin plays an important role in cellular processes, whose functioning involves dynamic formation and reorganization of fine structures of actin filaments. Frequently used confocal fluorescence and STED microscopy dyes were employed to image fixed PC-12 cells (dyed with phalloidin- fluorescein isothiocyante and live rat chondrosarcoma cells (RCS transfected with actin-green fluorescent protein (GFP. Compared to conventional confocal fluorescence microscopy, CW-STED microscopy shows improved spatial resolution in both fixed and live cells. We were able to monitor cell morphology changes continuously; however, the number of repetitive analyses were limited primarily by the dyes used in these experiments and could be improved with the use of dyes less susceptible to photobleaching. In conclusion, CW-STED may disclose new information for biological systems with a proper characteristic length scale. The challenges of using CW-STED microscopy to study cell structures are discussed.

  1. Dystroglycan Depletion Impairs Actin-Dependent Functions of Differentiated Kasumi-1 Cells.

    Directory of Open Access Journals (Sweden)

    Marco Antonio Escárcega-Tame

    Full Text Available Dystroglycan has recently been characterised in blood tissue cells, as part of the dystrophin glycoprotein complex involved in the differentiation process of neutrophils.In the present study we have investigated the role of dystroglycan in the human promyelocytic leukemic cell line Kasumi-1 differentiated to macrophage-like cells.We characterised the pattern expression and subcellular distribution of dystroglycans in non-differentiated and differentiated Kasumi-1 cells.Our results demonstrated by WB and flow cytometer assays that during the differentiation process to macrophages, dystroglycans were down-regulated; these results were confirmed with qRT-PCR assays. Additionally, depletion of dystroglycan by RNAi resulted in altered morphology and reduced properties of differentiated Kasumi-1 cells, including morphology, migration and phagocytic activities although secretion of IL-1β and expression of markers of differentiation are not altered.Our findings strongly implicate dystroglycan as a key membrane adhesion protein involved in actin-based structures during the differentiation process in Kasumi-1 cells.

  2. Iron Depletion by Deferoxamine Up-Regulates Glucose Uptake and Insulin Signaling in Hepatoma Cells and in Rat Liver

    OpenAIRE

    Dongiovanni, Paola; Valenti, Luca; Ludovica Fracanzani, Anna; Gatti, Stefano; Cairo, Gaetano; Fargion, Silvia.

    2008-01-01

    Iron depletion improves insulin resistance in patients with nonalcoholic fatty liver disease and diabetes and also stabilizes the hypoxia-inducible factor (HIF)-1, resulting in increased glucose uptake in vitro. This study investigated the effect of iron depletion by deferoxamine on insulin signaling and glucose uptake in HepG2 hepatocytes and in rat liver. In HepG2 cells, deferoxamine stabilized HIF-1α and induced the constitutive glucose transporter Glut1 and the insulin receptor. Up-regula...

  3. A versatile viral system for expression and depletion of proteins in mammalian cells.

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    Eric Campeau

    Full Text Available The ability to express or deplete proteins in living cells is crucial for the study of biological processes. Viral vectors are often useful to deliver DNA constructs to cells that are difficult to transfect by other methods. Lentiviruses have the additional advantage of being able to integrate into the genomes of non-dividing mammalian cells. However, existing viral expression systems generally require different vector backbones for expression of cDNA, small hairpin RNA (shRNA or microRNA (miRNA and provide limited drug selection markers. Furthermore, viral backbones are often recombinogenic in bacteria, complicating the generation and maintenance of desired clones. Here, we describe a collection of 59 vectors that comprise an integrated system for constitutive or inducible expression of cDNAs, shRNAs or miRNAs, and use a wide variety of drug selection markers. These vectors are based on the Gateway technology (Invitrogen whereby the cDNA, shRNA or miRNA of interest is cloned into an Entry vector and then recombined into a Destination vector that carries the chosen viral backbone and drug selection marker. This recombination reaction generates the desired product with >95% efficiency and greatly reduces the frequency of unwanted recombination in bacteria. We generated Destination vectors for the production of both retroviruses and lentiviruses. Further, we characterized each vector for its viral titer production as well as its efficiency in expressing or depleting proteins of interest. We also generated multiple types of vectors for the production of fusion proteins and confirmed expression of each. We demonstrated the utility of these vectors in a variety of functional studies. First, we show that the FKBP12 Destabilization Domain system can be used to either express or deplete the protein of interest in mitotically-arrested cells. Also, we generate primary fibroblasts that can be induced to senesce in the presence or absence of DNA damage

  4. Bisphosphonates target B cells to enhance humoral immune responses

    OpenAIRE

    Tonti, Elena; Jiménez de Oya, Nereida; Galliverti, Gabriele; Moseman, E. Ashley; Di Lucia, Pietro; Amabile, Angelo; Sammicheli, Stefano; De Giovanni, Marco; Sironi, Laura; Chevrier, Nicolas; Sitia, Giovanni; Gennari, Luigi; Guidotti, Luca G.; von Andrian, Ulrich H.; Iannacone, Matteo

    2013-01-01

    Bisphosphonates are a class of drugs that are widely used to inhibit loss of bone mass in patients. We show here that the administration of clinically relevant doses of bisphosphonates in mice increases antibody responses to live and inactive viruses, proteins, haptens and existing commercial vaccine formulations. Bisphosphonates exert this adjuvant-like activity in the absence of CD4+ and γδ T cells, neutrophils or dendritic cells and their effect does not rely on local macrophage depletion ...

  5. Induction of ssDNA-binding autoantibody secreting B cell immunity during murine malaria infection is a critical part of the protective immune responses.

    Science.gov (United States)

    Mannoor, Kaiissar; Li, Changchun; Inafuku, Masashi; Taniguchi, Tomoyo; Abo, Toru; Sato, Yoshiya; Watanabe, Hisami

    2013-01-01

    Although it has been hypothesized that autoimmune-like phenomena may play a critical role in the protective immune responses to both human and animal malaria, there are still no evidence-based data to support this view. In this study we demonstrate that the majority of anti-single stranded (ss) DNA autoantibody secreting B cells were confined to B220(+)CD21(+)CD23(-) cells and that these cells expanded significantly in the spleen of C57BL/6 mice infected with Plasmodium yoelii 17X non-lethal (PyNL). To determine the role of ssDNA-binding autoantibody secreting B cell responses in murine malaria, we conjugated generation 6 (poly) amidoamine dendrimer nanoparticles with ssDNA to deplete ssDNA-binding autoreactive B cells in vivo. Our data revealed that 55.5% of mice died after DNA-coated nanoparticle-mediated in vivo depletion of ssDNA-specific autoreactive B cells and subsequent challenge using PyNL. Adoptive transfer of B cells with ssDNA specificity to mice, followed by PyNL infection, caused a later appearance and inhibition of parasitemia. The possible mechanism by which the ssDNA-binding autoantibody secreting B cells is involved in the protection against murine malaria has also been demonstrated.

  6. Secondary specific immune response in vitro to MSV tumor cells.

    Science.gov (United States)

    Senik, A; Hebrero, F P; Levy, J P

    1975-12-15

    The interactions which occur between antigenic tumor cells and normal or immune lymphoid cells in a 3-day in vitro culture, have been studied with a murine sarcoma virus (MSV)-induced tumor. The 3H-thymidine incorporation of lymphoma cells growing in suspension, and the radioactive-chromium release of freshly sampled lymphoma cells regularly added to the culture, have been compared to determine the part played by immune lymphoid cells in cytolysis and cytostasis of the tumor-cell population. The cytolytic activity increases in the culture from day 0 to day 3. It is due, predominantly, to T-cells, and remains specific to antigens shared by MSV tumors and related lymphomas. This activity would be difficult to detect unless freshly sampled ascitic cells were used as targets, since the lymphoma cells spontaneously lose a part of their sensitivity to immune cytolysis during in vitro culture. The method used in the present experiments is a secondary chromium release test (SCRT), which measures the invitro secondary stimulation of cytotoxic T-lymphocytes (CTL) by tumor cells. In the absence of stimulatory cells, the CTL activity would have rapidly fallen in vitro. The cytostatic activity also increases during the 3 days in vitro, in parallel to the cytolytic activity: it is due to non-T-cells and remains mainly non-specific. The significance of these data for the interpretation of invitro demonstrated cell-mediated anti-tumor immune reactions is briefly discussed, as well as their relevance in the in vivo role of immune CTL. PMID:53210

  7. Tailored immune responses: novel effector helper T cell subsets in protective immunity.

    Directory of Open Access Journals (Sweden)

    Ervin E Kara

    2014-02-01

    Full Text Available Differentiation of naïve CD4⁺ cells into functionally distinct effector helper T cell subsets, characterised by distinct "cytokine signatures," is a cardinal strategy employed by the mammalian immune system to efficiently deal with the rapidly evolving array of pathogenic microorganisms encountered by the host. Since the T(H1/T(H2 paradigm was first described by Mosmann and Coffman, research in the field of helper T cell biology has grown exponentially with seven functionally unique subsets having now been described. In this review, recent insights into the molecular mechanisms that govern differentiation and function of effector helper T cell subsets will be discussed in the context of microbial infections, with a focus on how these different helper T cell subsets orchestrate immune responses tailored to combat the nature of the pathogenic threat encountered.

  8. Tailored immune responses: novel effector helper T cell subsets in protective immunity.

    Science.gov (United States)

    Kara, Ervin E; Comerford, Iain; Fenix, Kevin A; Bastow, Cameron R; Gregor, Carly E; McKenzie, Duncan R; McColl, Shaun R

    2014-02-01

    Differentiation of naïve CD4⁺ cells into functionally distinct effector helper T cell subsets, characterised by distinct "cytokine signatures," is a cardinal strategy employed by the mammalian immune system to efficiently deal with the rapidly evolving array of pathogenic microorganisms encountered by the host. Since the T(H)1/T(H)2 paradigm was first described by Mosmann and Coffman, research in the field of helper T cell biology has grown exponentially with seven functionally unique subsets having now been described. In this review, recent insights into the molecular mechanisms that govern differentiation and function of effector helper T cell subsets will be discussed in the context of microbial infections, with a focus on how these different helper T cell subsets orchestrate immune responses tailored to combat the nature of the pathogenic threat encountered.

  9. Regulatory T cells in immune-mediated renal disease.

    Science.gov (United States)

    Ghali, Joanna R; Wang, Yuan Min; Holdsworth, Stephen R; Kitching, A Richard

    2016-02-01

    Regulatory T cells (Tregs) are CD4+ T cells that can suppress immune responses by effector T cells, B cells and innate immune cells. This review discusses the role that Tregs play in murine models of immune-mediated renal diseases and acute kidney injury and in human autoimmune kidney disease (such as systemic lupus erythematosus, anti-glomerular basement membrane disease, anti-neutrophil cytoplasmic antibody-associated vasculitis). Current research suggests that Tregs may be reduced in number and/or have impaired regulatory function in these diseases. Tregs possess several mechanisms by which they can limit renal and systemic inflammatory immune responses. Potential therapeutic applications involving Tregs include in vivo induction of Tregs or inducing Tregs from naïve CD4+ T cells or expanding natural Tregs ex vivo, to use as a cellular therapy. At present, the optimal method of generating a phenotypically stable pool of Tregs with long-lasting suppressive effects is not established, but human studies in renal transplantation are underway exploring the therapeutic potential of Tregs as a cellular therapy, and if successful may have a role as a novel therapy in immune-mediated renal diseases. PMID:26206106

  10. Zinc protects human kidney cells from depleted uranium-induced apoptosis.

    Science.gov (United States)

    Hao, Yuhui; Ren, Jiong; Liu, Cong; Li, Hong; Liu, Jing; Yang, Zhangyou; Li, Rong; Su, Yongping

    2014-03-01

    Depleted uranium (DU) is a weak radioactive heavy metal, and zinc (Zn) is an effective antidote to heavy metal poisoning. However, the effect of Zn on DU-induced cytotoxicity and apoptosis is not completely understood. The purpose of this study was to evaluate the effect of Zn on DU-induced cell apoptosis in human kidney cells (HK-2) and explore its molecular mechanism. Pre-treatment with Zn significantly inhibited DU-induced apoptosis. It reduced the formation of reactive oxygen species in the cells, increased the catalase (CAT) and glutathione (GSH) concentrations, suppressed the DU-induced soluble Fas receptor (sFasR) and soluble Fas ligand (sFasL) overexpression, suppressed the release of cytochrome c and apoptosis inhibitor factor (AIF) from mitochondria to cytoplasm, inhibited the activation of caspase-9, caspase-8 and caspase-3, and induced metallothionein (MT) expression. Furthermore, exogenous MT effectively inhibited DU-induced cell apoptosis. In conclusion, mitochondrial and FasR-mediated apoptosis pathways contribute to DU-induced apoptosis in HK-2 cells. Through independent mechanisms, such as indirect antioxidant effects, inhibition of the activation of caspase-9, caspase-8 and caspase-3, and induction of MT expression, Zn inhibits DU-induced apoptosis. PMID:24330236

  11. The role of cell-mediated immunity in typhoid.

    Science.gov (United States)

    Mabel, T J; Paniker, C K

    1979-06-01

    The cell-mediated immunity in typhoid was assessed by the leukocyte migration inhibition test and delayed hypersensitivity skin test in 60 clinical typhoid patients. The property of leukocyte migration inhibition appeared first and was positive in 28 of 60 (46.7%) patients on admission and 45 of 60 (75%) at the time of discharge. This difference was definitely more in blood culture positive patients. The delayed hypersensitivity appeared later and was positive in 18 of 60 (30%) on admission and 31 of 60 (51.7%) at the time of discharge. Patients with positive cellular-immune response against typhoid antigen did not develop relapse. On the whole cell-mediated immunity seems to play an important role in typoid. The control groups--the medical and surgical patients, doctors, clinical students and preclinical students--showed positive cellular immune response of 43.3 81.3, 40.7 and 25% respectively. The significance of these results is discussed.

  12. Host Cell Autophagy in Immune Response to Zoonotic Infections

    Directory of Open Access Journals (Sweden)

    Panagiotis Skendros

    2012-01-01

    Full Text Available Autophagy is a fundamental homeostatic process in which cytoplasmic targets are sequestered within double-membraned autophagosomes and subsequently delivered to lysosomes for degradation. Accumulating evidence supports the pivotal role of autophagy in host defense against intracellular pathogens implicating both innate and adaptive immunity. Many of these pathogens cause common zoonotic infections worldwide. The induction of the autophagic machinery by innate immune receptors signaling, such as TLRs, NOD1/2, and p62/SQSTM1 in antigen-presenting cells results in inhibition of survival and elimination of invading pathogens. Furthermore, Th1 cytokines induce the autophagic process, whereas autophagy also contributes to antigen processing and MHC class II presentation, linking innate to adaptive immunity. However, several pathogens have developed strategies to avoid autophagy or exploit autophagic machinery to their advantage. This paper focuses on the role of host cell autophagy in the regulation of immune response against intracellular pathogens, emphasizing on selected bacterial and protozoan zoonoses.

  13. MHCII-mediated dialog between group 2 innate lymphoid cells and CD4(+) T cells potentiates type 2 immunity and promotes parasitic helminth expulsion.

    OpenAIRE

    Oliphant, CJ; Hwang, YY; Walker, JA; Salimi, M; Wong, SH; Brewer, JM; Englezakis, A; Barlow, JL; Hams, E; Scanlon, ST; Ogg, GS; Fallon, PG; McKenzie, ANJ

    2016-01-01

    Summary Group 2 innate lymphoid cells (ILC2s) release interleukin-13 (IL-13) during protective immunity to helminth infection and detrimentally during allergy and asthma. Using two mouse models to deplete ILC2s in vivo, we demonstrate that T helper 2 (Th2) cell responses are impaired in the absence of ILC2s. We show that MHCII-expressing ILC2s interact with antigen-specific T cells to instigate a dialog in which IL-2 production from T cells promotes ILC2 proliferation and IL-13 production. De...

  14. Hepatic stellate cells and innate immunity in alcoholic liver disease

    Institute of Scientific and Technical Information of China (English)

    Yang-Gun Suh; Won-Il Jeong

    2011-01-01

    Constant alcohol consumption is a major cause of chronic liver disease, and there has been a growing concern regarding the increased mortality rates worldwide. Alcoholic liver diseases (ALDs) range from mild to more severe conditions, such as steatosis, steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. The liver is enriched with innate immune cells (e.g. natural killer cells and Kupffer cells) and hepatic stellate cells (HSCs), and interestingly, emerging evidence suggests that innate immunity contributes to the development of ALDs (e.g. steatohepatitis and liver fibrosis). Indeed, HSCs play a crucial role in alcoholic steatosis via production of endocannabinoid and retinol metabolites. This review describes the roles of the innate immunity and HSCs in the pathogenesis of ALDs, and suggests therapeutic targets and strategies to assist in the reduction of ALD.

  15. Tumor Regulatory T Cells Potently Abrogate Antitumor Immunity1

    OpenAIRE

    Liu, Zuqiang; Kim, Jin H.; Falo, Louis D.; You, Zhaoyang

    2009-01-01

    Treg from mice bearing a breast tumor were elevated (tumor Treg). In vitro, whereas tumor Treg ability to inhibit tumor-primed CD4+ T cell activity is comparable to Treg from naïve mice (naïve Treg), only tumor Treg suppress naïve CD8+ T cell activation and DC function. Neither tumor Treg nor naïve Treg can suppress antitumor immunity at the effector phase of the immune response induced by adoptively-transferred tumor-primed CD4+ T cells. This is consistent with the observation that, in this ...

  16. "Flagellated" cancer cells propel anti-tumor immunity.

    Science.gov (United States)

    Garaude, Johan; Blander, J Magarian

    2012-09-01

    The use of innate immune receptor agonists in cancer therapies has suffered from many drawbacks. Our recent observations suggest that some of these hurdles can be overcome by introducing flagellin into tumor cells to promote tumor antigen presentation by dendritic cells (DCs) and simultaneously trigger two types of pattern recognition receptors (PRRs).

  17. Optimization of an Enrichment process for Circulating tumor cells from the blood of Head and Neck Cancer patients through depletion of normal cells

    OpenAIRE

    Yang, Liying; Lang, James C.; Balasubramanian, Priya; Jatana, Kris R.; Schuller, David; Agrawal, Amit; Zborowski, Maciej; Chalmers, Jeffrey J.

    2009-01-01

    The optimization of a purely negative depletion, enrichment process for circulating tumor cells, CTC's, in the peripheral blood of Head and Neck cancer patients is presented. The enrichment process uses a red cell lysis step followed by immunomagnetic labeling, and subsequent depletion, of CD45 positive cells. A number of relevant variables are quantified, or attempted to be quantified, which control the performance of the enrichment process. Six different immunomagnetic labeling combinations...

  18. Sea urchin immune cells as sentinels of environmental stress.

    Science.gov (United States)

    Pinsino, Annalisa; Matranga, Valeria

    2015-03-01

    Echinoderms, an ancient and very successful phylum of marine invertebrates, play a central role in the maintenance of ecosystem integrity and are constantly exposed to environmental pressure, including: predation, changes in temperature and pH, hypoxia, pathogens, UV radiation, metals, toxicants, and emerging pollutants like nanomaterials. The annotation of the sea urchin genome, so closely related to humans and other vertebrate genomes, revealed an unusually complex immune system, which may be the basis for why sea urchins can adapt to different marine environments and survive even in hazardous conditions. In this review, we give a brief overview of the morphological features and recognized functions of echinoderm immune cells with a focus on studies correlating stress and immunity in the sea urchin. Immune cells from adult Paracentrotus lividus, which have been introduced in the last fifteen years as sentinels of environmental stress, are valid tools to uncover basic molecular and regulatory mechanisms of immune responses, supporting their use in immunological research. Here we summarize laboratory and field studies that reveal the amenability of sea urchin immune cells for toxicological testing. PMID:25463510

  19. Transfusion of leukocyte-depleted red blood cells is not a risk factor for nosocomial infections in critically ill children

    NARCIS (Netherlands)

    van der Wal, Judith; van Heerde, Marc; Markhorst, Dick G.; Kneyber, Martin C. J.

    2011-01-01

    Objectives: Transfusion of red blood cells is increasingly linked with adverse outcomes in critically ill children. We tested the hypothesis that leukocyte-depleted red blood cell transfusions were independently associated with increased development of bloodstream infections, ventilator-associated p

  20. A single dose of rituximab does not deplete B cells in secondary lymphoid organs but alters phenotype and function

    NARCIS (Netherlands)

    Kamburova, E.G.; Koenen, H.J.P.M.; Borgman, K.J.; Berge, I.J. Ten; Joosten, I.; Hilbrands, L.B.

    2013-01-01

    A single dose of the anti-CD20 monoclonal antibody rituximab induces a nearly complete B cell depletion in peripheral blood, but not in secondary lymphoid organs. Modulation of this remaining B cell population due to rituximab treatment may contribute to the therapeutic effects of rituximab. To asse

  1. Mucosal-associated invariant T (MAIT cells: new players in anti-bacterial immunity

    Directory of Open Access Journals (Sweden)

    James E Ussher

    2014-10-01

    Full Text Available Mucosal-associated invariant T (MAIT cells are an innate-like T cell population involved in antibacterial immunity. In humans, MAIT cells are abundant, comprising ~ 10% of the CD8+ T cell compartment in blood. They are enriched at mucosal sites and are particularly prevalent within the liver. MAIT cells are defined by the expression of a semi-invariant T cell receptor (Vα7.2-Jα33/12/20 and are restricted by the non-polymorphic, highly evolutionarily conserved MHC class Ib molecule, MR1. MR1 has recently been shown to present an unstable pyrimidine intermediate derived from a biosynthetic precursor of riboflavin; riboflavin biosynthesis occurs in many bacteria but not in humans. Consistent with this, MAIT cells are responsive to riboflavin-metabolizing bacteria, including Salmonella. In mouse models, MAIT cells have been shown to play a non-redundant role in antibacterial immunity, including against E. coli, Klebsiella pneumoniae, and Mycobacterium bovis BCG. In humans, MAIT cells are decreased in frequency in the blood of patients with tuberculosis or pneumonia, and their frequency has been inversely correlated with the risk of subsequent systemic bacterial infection in patients in intensive care. Intriguingly, MAIT cells are also depleted from the blood early in HIV infection and fail to recover with antiretroviral therapy, which may contribute to the susceptibility of patients infected with HIV to certain bacterial infections, including with non-typhoidal Salmonella. In this review we will discuss what is currently known about MAIT cells, the role that Salmonella has played in elucidating MAIT cell restriction and function, and the role MAIT cells might play in the control of Salmonella infection.

  2. B cells as a target of immune modulation

    Directory of Open Access Journals (Sweden)

    Hawker Kathleen

    2009-01-01

    Full Text Available B cells have recently been identified as an integral component of the immune system; they play a part in autoimmunity through antigen presentation, antibody secretion, and complement activation. Animal models of multiple sclerosis (MS suggest that myelin destruction is partly mediated through B cell activation (and plasmablasts. MS patients with evidence of B cell involvement, as compared to those without, tend to have a worse prognosis. Finally, the significant decrease in new gadolinium-enhancing lesions, new T2 lesions, and relapses in MS patients treated with rituximab (a monoclonal antibody against CD20 on B cells leads us to the conclusion that B cells play an important role in MS and that immune modulation of these cells may ameliorate the disease. This article will explore the role of B cells in MS and the rationale for the development of B cell-targeted therapeutics. MS is an immune-mediated disease that affects over 2 million people worldwide and is the number one cause of disability in young patients. Most therapeutic targets have focused on T cells; however, recently, the focus has shifted to the role of B cells in the pathogenesis of MS and the potential of B cells as a therapeutic target.

  3. Transplantation and innate immunity: the lesson of natural killer cells

    Directory of Open Access Journals (Sweden)

    Moretta Lorenzo

    2009-12-01

    Full Text Available Abstract Natural killer cells have been demonstrated to play a major role in mediating an anti-leukemia effect in patients given a T-cell depleted allogeneic hematopoietic stem cell transplantation from an HLA-haploidentical family donor. In particular, donor-derived natural killer cells, which are alloreactive (i.e. KIR/HLA mismatched towards recipient cells, significantly contribute to the eradication of leukemia blasts escaping the preparative regimen to transplantation. A recent study on high-risk pediatric acute lymphoblastic leukemia refractory to chemotherapy further highlighted the importance of donors with alloreactive natural killer cells in haploidentical hematopoietic stem cell transplantation, as it demonstrated that these cells can emerge starting from the fourth-fifth month after the allograft and persist for many months. This study represents a major breakthrough in the cure of otherwise fatal leukemias, providing information on the best criteria for choosing the optimal donor.

  4. Murine and bovine γδ T cells enhance innate immunity against Brucella abortus infections.

    Directory of Open Access Journals (Sweden)

    Jerod A Skyberg

    Full Text Available γδ T cells have been postulated to act as a first line of defense against infectious agents, particularly intracellular pathogens, representing an important link between the innate and adaptive immune responses. Human γδ T cells expand in the blood of brucellosis patients and are active against Brucella in vitro. However, the role of γδ T cells in vivo during experimental brucellosis has not been studied. Here we report TCRδ(-/- mice are more susceptible to B. abortus infection than C57BL/6 mice at one week post-infection as measured by splenic colonization and splenomegaly. An increase in TCRγδ cells was observed in the spleens of B. abortus-infected C57BL/6 mice, which peaked at two weeks post-infection and occurred concomitantly with diminished brucellae. γδ T cells were the major source of IL-17 following infection and also produced IFN-γ. Depletion of γδ T cells from C57BL/6, IL-17Rα(-/-, and GMCSF(-/- mice enhanced susceptibility to B. abortus infection although this susceptibility was unaltered in the mutant mice; however, when γδ T cells were depleted from IFN-γ(-/- mice, enhanced susceptibility was observed. Neutralization of γδ T cells in the absence of TNF-α did not further impair immunity. In the absence of TNF-α or γδ T cells, B. abortus-infected mice showed enhanced IFN-γ, suggesting that they augmented production to compensate for the loss of γδ T cells and/or TNF-α. While the protective role of γδ T cells was TNF-α-dependent, γδ T cells were not the major source of TNF-α and activation of γδ T cells following B. abortus infection was TNF-α-independent. Additionally, bovine TCRγδ cells were found to respond rapidly to B. abortus infection upon co-culture with autologous macrophages and could impair the intramacrophage replication of B. abortus via IFN-γ. Collectively, these results demonstrate γδ T cells are important for early protection to B. abortus infections.

  5. B Cells Are Critical to T-cell—Mediated Antitumor Immunity Induced by a Combined Immune-Stimulatory/Conditionally Cytotoxic Therapy for Glioblastoma

    Directory of Open Access Journals (Sweden)

    Marianela Candolfi

    2011-10-01

    Full Text Available We have demonstrated that modifying the tumor microenvironment through intratumoral administration of adenoviral vectors (Ad encoding the conditional cytotoxic molecule, i.e., HSV1-TK and the immune-stimulatory cytokine, i.e., fms-like tyrosine kinase 3 ligand (Flt3L leads to T-cell-dependent tumor regression in rodent models of glioblastoma. We investigated the role of B cells during immune-mediated glioblastoma multiforme regression. Although treatment with Ad-TK+Ad-Flt3L induced tumor regression in 60% of wild-type (WT mice, it completely failed in B-cell-deficient Igh6-/- mice. Tumor-specific T-cell precursors were detected in Ad-TK+Ad-Flt3L-treated WT mice but not in Igh6-/- mice. The treatment also failed in WT mice depleted of total B cells or marginal zone B cells. Because we could not detect circulating antibodies against tumor cells and the treatment was equally efficient in WT mice and in mice with B-cell-specific deletion of Prdm 1 (encoding Blimp-1, in which B cells are present but unable to fully differentiate into antibody-secreting plasma cells, tumor regression in this model is not dependent on B cells’ production of tumor antigen-specific immunoglobulins. Instead, B cells seem to play a role as antigen-presenting cells (APCs. Treatment with Ad-TK+Ad-Flt3L led to an increase in the number of B cells in the cervical lymph nodes, which stimulated the proliferation of syngeneic T cells and induced clonal expansion of antitumor T cells. Our data show that B cells act as APCs, playing a critical role in clonal expansion of tumor antigen-specific T cells and brain tumor regression.

  6. Deconvoluting post-transplant immunity: cell subset-specific mapping reveals pathways for activation and expansion of memory T, monocytes and B cells.

    Directory of Open Access Journals (Sweden)

    Yevgeniy A Grigoryev

    Full Text Available A major challenge for the field of transplantation is the lack of understanding of genomic and molecular drivers of early post-transplant immunity. The early immune response creates a complex milieu that determines the course of ensuing immune events and the ultimate outcome of the transplant. The objective of the current study was to mechanistically deconvolute the early immune response by purifying and profiling the constituent cell subsets of the peripheral blood. We employed genome-wide profiling of whole blood and purified CD4, CD8, B cells and monocytes in tandem with high-throughput laser-scanning cytometry in 10 kidney transplants sampled serially pre-transplant, 1, 2, 4, 8 and 12 weeks. Cytometry confirmed early cell subset depletion by antibody induction and immunosuppression. Multiple markers revealed the activation and proliferative expansion of CD45RO(+CD62L(- effector memory CD4/CD8 T cells as well as progressive activation of monocytes and B cells. Next, we mechanistically deconvoluted early post-transplant immunity by serial monitoring of whole blood using DNA microarrays. Parallel analysis of cell subset-specific gene expression revealed a unique spectrum of time-dependent changes and functional pathways. Gene expression profiling results were validated with 157 different probesets matching all 65 antigens detected by cytometry. Thus, serial blood cell monitoring reflects the profound changes in blood cell composition and immune activation early post-transplant. Each cell subset reveals distinct pathways and functional programs. These changes illuminate a complex, early phase of immunity and inflammation that includes activation and proliferative expansion of the memory effector and regulatory cells that may determine the phenotype and outcome of the kidney transplant.

  7. DMPD: Zinc in human health: effect of zinc on immune cells. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18385818 Zinc in human health: effect of zinc on immune cells. Prasad AS. Mol Med. ...2008 May-Jun;14(5-6):353-7. (.png) (.svg) (.html) (.csml) Show Zinc in human health: effect of zinc on immun...e cells. PubmedID 18385818 Title Zinc in human health: effect of zinc on immune cells. Authors Prasad AS. Pu

  8. Advances in targeting cell surface signalling molecules for immune modulation

    Science.gov (United States)

    Yao, Sheng; Zhu, Yuwen; Chen, Lieping

    2013-01-01

    The past decade has witnessed a surge in the development of immunomodulatory approaches to combat a broad range of human diseases, including cancer, viral infections, autoimmunity and inflammation as well as in the prevention of transplant rejection. Immunomodulatory approaches mostly involve the use of monoclonal antibodies or recombinant fusion proteins that target cell surface signalling molecules on immune cells to drive immune responses towards the desired direction. Advances in our understanding of the human immune system, along with valuable lessons learned from the first generation of therapeutic biologics, are aiding the design of the next generation of immunomodulatory biologics with better therapeutic efficacy, minimized adverse effects and long-lasting clinical benefit. The recent encouraging results from antibodies targeting programmed cell death protein 1 (PD1) and B7 homolog 1 (B7H1; also known as PDL1) for the treatment of various advanced human cancers show that immunomodulatory therapy has come of age. PMID:23370250

  9. Plasmacytoid dendritic cells in antiviral immunity and autoimmunity

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Plasmacytoid dendritic cells (pDCs) represent a unique and crucial immune cell population capable of producing large amounts of type I interferons (IFNs) in response to viral infection.The function of pDCs as the professional type I IFN-producing cells is linked to their selective expression of Toll-like receptor 7 (TLR7) and TLR9,which sense viral nucleic acids within the endosomal compartments.Type I IFNs produced by pDCs not only directly inhibit viral replication but also play an essential role in linking the innate and adaptive immune system.The aberrant activation of pDCs by self nucleic acids through TLR signaling and the ongoing production of type I IFNs do occur in some autoimmune diseases.Therefore,pDC may serve as an attractive target for therapeutic manipulations of the immune system to treat viral infectious diseases and autoimmune diseases.

  10. Low cost delivery of proteins bioencapsulated in plant cells to human non-immune or immune modulatory cells.

    Science.gov (United States)

    Xiao, Yuhong; Kwon, Kwang-Chul; Hoffman, Brad E; Kamesh, Aditya; Jones, Noah T; Herzog, Roland W; Daniell, Henry

    2016-02-01

    Targeted oral delivery of GFP fused with a GM1 receptor binding protein (CTB) or human cell penetrating peptide (PTD) or dendritic cell peptide (DCpep) was investigated. Presence of GFP(+) intact plant cells between villi of ileum confirm their protection in the digestive system from acids/enzymes. Efficient delivery of GFP to gut-epithelial cells by PTD or CTB and to M cells by all these fusion tags confirm uptake of GFP in the small intestine. PTD fusion delivered GFP more efficiently to most tissues or organs than the other two tags. GFP was efficiently delivered to the liver by all fusion tags, likely through the gut-liver axis. In confocal imaging studies of human cell lines using purified GFP fused with different tags, GFP signal of DCpep-GFP was only detected within dendritic cells. PTD-GFP was only detected within kidney or pancreatic cells but not in immune modulatory cells (macrophages, dendritic, T, B, or mast cells). In contrast, CTB-GFP was detected in all tested cell types, confirming ubiquitous presence of GM1 receptors. Such low-cost oral delivery of protein drugs to sera, immune system or non-immune cells should dramatically lower their cost by elimination of prohibitively expensive fermentation, protein purification cold storage/transportation and increase patient compliance. PMID:26706477

  11. Induction of natural killer cell-dependent antitumor immunity by the Autographa californica multiple nuclear polyhedrosis virus.

    Science.gov (United States)

    Kitajima, Masayuki; Abe, Takayuki; Miyano-Kurosaki, Naoko; Taniguchi, Masaru; Nakayama, Toshinori; Takaku, Hiroshi

    2008-02-01

    Wild-type Autographa californica multiple nuclear polyhedrosis virus (AcMNPV) infects a variety of mammalian cell types in vitro, but does not replicate in these cells. We investigated the effects of AcMNPV in the induction of the immune response and tumor metastasis in mice. After intravenous injection, AcMNPV was taken up by the liver and spleen, and preferentially infected dendritic cells (DCs) and B cells in the spleen; costimulatory molecules CD40, CD80, and CD86 were upregulated in the DCs. The hepatic mononuclear cells (MNCs) in these animals were highly cytotoxic to natural killer (NK)-sensitive YAC-1 and B16 melanoma cells, but not to NK-resistant EL4 cells. Intravenous injection of AcMNPV-induced NK cell proliferation in the liver and spleen, and enhanced antitumor immunity in mice with B16 liver metastases. Furthermore, such treatment increased the survival of C57BL/6, J alpha 281 (-/-), and interferon (IFN)-gamma (-/-) mice that were previously injected with B16 tumor cells. AcMNPV injection did not enhance the survival of NK cell-depleted mice. Moreover, one AcMNPV treatment effectively prolonged survival in a B16 liver metastasis model, and was equivalent to five treatments with recombinant interleukin-12 (IL-12) protein. These findings suggest that AcMNPV efficiently stimulates NK cell-mediated antitumor immunity. PMID:18059370

  12. Oxidative damage of BEAS-2B cells induced by depleted uranium and protection by DMSO

    International Nuclear Information System (INIS)

    Objective: To observe the oxidative damage in human bronchial epithelial cells (BEAS-2B) induced by depleted uranium (DU) and protection of DMSO. Methods: The measurement of extracellular superoxide anions (O2-·) was based on the reduction of ferricytochrome C. Quantitative analysis of extracellular hydrogen peroxides (H2O2) was used by the horseradish peroxidase-dependent oxidation of phenol red. The determination of extracellular hydroxyl radicals (· OH) was based on discoloration of safranine T. Ethidium bromide and 2, 7'-dichlorofluorescein, fluorescent products of the membrane-permeable dyes-hydroethineand 2,7'-dichloroflurescin diacetate were used to monitor the intracellular production of O2- · and H2O2 by fluorometric method. The enzyme activity of SOD and GSH were measured by chemiluminescence and spectrophotometric method, respectively. Results: The ROS production, including H2O2, O2- · and · OH, increased remarkably which induced by DU in BEAs-2B cells. The enzyme activity of SOD and GSH was descended remarkedly. These changes could be effectively inhibited by 0.5% of DMSO. Conclusions: DU causes oxidative damage to BEAS-2B cells. Through removing active oxygen, DMSO can inhibit oxidative damage of DU. (authors)

  13. A mitotic kinase scaffold depleted in testicular seminomas impacts spindle orientation in germ line stem cells.

    Science.gov (United States)

    Hehnly, Heidi; Canton, David; Bucko, Paula; Langeberg, Lorene K; Ogier, Leah; Gelman, Irwin; Santana, L Fernando; Wordeman, Linda; Scott, John D

    2015-01-01

    Correct orientation of the mitotic spindle in stem cells underlies organogenesis. Spindle abnormalities correlate with cancer progression in germ line-derived tumors. We discover a macromolecular complex between the scaffolding protein Gravin/AKAP12 and the mitotic kinases, Aurora A and Plk1, that is down regulated in human seminoma. Depletion of Gravin correlates with an increased mitotic index and disorganization of seminiferous tubules. Biochemical, super-resolution imaging, and enzymology approaches establish that this Gravin scaffold accumulates at the mother spindle pole during metaphase. Manipulating elements of the Gravin-Aurora A-Plk1 axis prompts mitotic delay and prevents appropriate assembly of astral microtubules to promote spindle misorientation. These pathological responses are conserved in seminiferous tubules from Gravin(-/-) mice where an overabundance of Oct3/4 positive germ line stem cells displays randomized orientation of mitotic spindles. Thus, we propose that Gravin-mediated recruitment of Aurora A and Plk1 to the mother (oldest) spindle pole contributes to the fidelity of symmetric cell division. PMID:26406118

  14. A mitotic kinase scaffold depleted in testicular seminomas impacts spindle orientation in germ line stem cells.

    Science.gov (United States)

    Hehnly, Heidi; Canton, David; Bucko, Paula; Langeberg, Lorene K; Ogier, Leah; Gelman, Irwin; Santana, L Fernando; Wordeman, Linda; Scott, John D

    2015-09-25

    Correct orientation of the mitotic spindle in stem cells underlies organogenesis. Spindle abnormalities correlate with cancer progression in germ line-derived tumors. We discover a macromolecular complex between the scaffolding protein Gravin/AKAP12 and the mitotic kinases, Aurora A and Plk1, that is down regulated in human seminoma. Depletion of Gravin correlates with an increased mitotic index and disorganization of seminiferous tubules. Biochemical, super-resolution imaging, and enzymology approaches establish that this Gravin scaffold accumulates at the mother spindle pole during metaphase. Manipulating elements of the Gravin-Aurora A-Plk1 axis prompts mitotic delay and prevents appropriate assembly of astral microtubules to promote spindle misorientation. These pathological responses are conserved in seminiferous tubules from Gravin(-/-) mice where an overabundance of Oct3/4 positive germ line stem cells displays randomized orientation of mitotic spindles. Thus, we propose that Gravin-mediated recruitment of Aurora A and Plk1 to the mother (oldest) spindle pole contributes to the fidelity of symmetric cell division.

  15. Antitumor Immunity Produced by the Liver Kupffer Cells, NK Cells, NKT Cells, and CD8+ CD122+ T Cells

    OpenAIRE

    Shuhji Seki; Hiroyuki Nakashima; Masahiro Nakashima; Manabu Kinoshita

    2011-01-01

    Mouse and human livers contain innate immune leukocytes, NK cells, NKT cells, and macrophage-lineage Kupffer cells. Various bacterial components, including Toll-like receptor (TLR) ligands and an NKT cell ligand ( α -galactocylceramide), activate liver Kupffer cells, which produce IL-1, IL-6, IL-12, and TNF. IL-12 activates hepatic NK cells and NKT cells to produce IFN- γ , which further activates hepatic T cells, in turn activating phagocytosis and cytokine production by Kupffer cells in a p...

  16. Peptide pool immunization and CD8+ T cell reactivity

    DEFF Research Database (Denmark)

    Rasmussen, Susanne B; Harndahl, Mikkel N; Buus, Anette Stryhn;

    2013-01-01

    Mice were immunized twice with a pool of five peptides selected among twenty 8-9-mer peptides for their ability to form stable complexes at 37°C with recombinant H-2K(b) (half-lives 10-15h). Vaccine-induced immunity of splenic CD8(+) T cells was studied in a 24h IFNγ Elispot assay. Surprisingly......, IFNγ spot-formation was observed without addition of peptide to the assay culture at 3 weeks and 3 months after immunization. To clarify if IFNγ spot formation in the absence of peptide exposure ex vivo is caused by the peptide-pool per se, mice were immunized with single peptides. Three of the five...

  17. A low T regulatory cell response may contribute to both viral control and generalized immune activation in HIV controllers.

    Directory of Open Access Journals (Sweden)

    Peter W Hunt

    Full Text Available HIV-infected individuals maintaining undetectable viremia in the absence of therapy (HIV controllers often maintain high HIV-specific T cell responses, which has spurred the development of vaccines eliciting HIV-specific T cell responses. However, controllers also often have abnormally high T cell activation levels, potentially contributing to T cell dysfunction, CD4+ T cell depletion, and non-AIDS morbidity. We hypothesized that a weak T regulatory cell (Treg response might contribute to the control of viral replication in HIV controllers, but might also contribute to generalized immune activation, contributing to CD4+ T cell loss. To address these hypotheses, we measured frequencies of activated (CD38+ HLA-DR+, regulatory (CD4+CD25+CD127(dim, HIV-specific, and CMV-specific T cells among HIV controllers and 3 control populations: HIV-infected individuals with treatment-mediated viral suppression (ART-suppressed, untreated HIV-infected "non-controllers" with high levels of viremia, and HIV-uninfected individuals. Despite abnormally high T cell activation levels, controllers had lower Treg frequencies than HIV-uninfected controls (P = 0.014. Supporting the propensity for an unusually low Treg response to viral infection in HIV controllers, we observed unusually high CMV-specific CD4+ T cell frequencies and a strong correlation between HIV-specific CD4+ T cell responses and generalized CD8+ T cell activation levels in HIV controllers (P ≤ 0.001. These data support a model in which low frequencies of Tregs in HIV controllers may contribute to an effective adaptive immune response, but may also contribute to generalized immune activation, potentially contributing to CD4 depletion.

  18. Follicular helper T cell in immunity and autoimmunity

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    D. Mesquita Jr

    2016-01-01

    Full Text Available The traditional concept that effector T helper (Th responses are mediated by Th1/Th2 cell subtypes has been broadened by the recent demonstration of two new effector T helper cells, the IL-17 producing cells (Th17 and the follicular helper T cells (Tfh. These new subsets have many features in common, such as the ability to produce IL-21 and to express the IL-23 receptor (IL23R, the inducible co-stimulatory molecule ICOS, and the transcription factor c-Maf, all of them essential for expansion and establishment of the final pool of both subsets. Tfh cells differ from Th17 by their ability to home to B cell areas in secondary lymphoid tissue through interactions mediated by the chemokine receptor CXCR5 and its ligand CXCL13. These CXCR5+ CD4+ T cells are considered an effector T cell type specialized in B cell help, with a transcriptional profile distinct from Th1 and Th2 cells. The role of Tfh cells and its primary product, IL-21, on B-cell activation and differentiation is essential for humoral immunity against infectious agents. However, when deregulated, Tfh cells could represent an important mechanism contributing to exacerbated humoral response and autoantibody production in autoimmune diseases. This review highlights the importance of Tfh cells by focusing on their biology and differentiation processes in the context of normal immune response to infectious microorganisms and their role in the pathogenesis of autoimmune diseases.

  19. Follicular helper T cell in immunity and autoimmunity.

    Science.gov (United States)

    Mesquita, D; Cruvinel, W M; Resende, L S; Mesquita, F V; Silva, N P; Câmara, N O S; Andrade, L E C

    2016-01-01

    The traditional concept that effector T helper (Th) responses are mediated by Th1/Th2 cell subtypes has been broadened by the recent demonstration of two new effector T helper cells, the IL-17 producing cells (Th17) and the follicular helper T cells (Tfh). These new subsets have many features in common, such as the ability to produce IL-21 and to express the IL-23 receptor (IL23R), the inducible co-stimulatory molecule ICOS, and the transcription factor c-Maf, all of them essential for expansion and establishment of the final pool of both subsets. Tfh cells differ from Th17 by their ability to home to B cell areas in secondary lymphoid tissue through interactions mediated by the chemokine receptor CXCR5 and its ligand CXCL13. These CXCR5+ CD4+ T cells are considered an effector T cell type specialized in B cell help, with a transcriptional profile distinct from Th1 and Th2 cells. The role of Tfh cells and its primary product, IL-21, on B-cell activation and differentiation is essential for humoral immunity against infectious agents. However, when deregulated, Tfh cells could represent an important mechanism contributing to exacerbated humoral response and autoantibody production in autoimmune diseases. This review highlights the importance of Tfh cells by focusing on their biology and differentiation processes in the context of normal immune response to infectious microorganisms and their role in the pathogenesis of autoimmune diseases. PMID:27096200

  20. Single-cell time-lapse analysis of depletion of the universally conserved essential protein YgjD

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    Ackermann Martin

    2011-05-01

    Full Text Available Abstract Background The essential Escherichia coli gene ygjD belongs to a universally conserved group of genes whose function has been the focus of a number of recent studies. Here, we put ygjD under control of an inducible promoter, and used time-lapse microscopy and single cell analysis to investigate the phenotypic consequences of the depletion of YgjD protein from growing cells. Results We show that loss of YgjD leads to a marked decrease in cell size and termination of cell division. The transition towards smaller size occurs in a controlled manner: cell elongation and cell division remain coupled, but cell size at division decreases. We also find evidence that depletion of YgjD leads to the synthesis of the intracellular signaling molecule (pppGpp, inducing a cellular reaction resembling the stringent response. Concomitant deletion of the relA and spoT genes - leading to a strain that is uncapable of synthesizing (pppGpp - abrogates the decrease in cell size, but does not prevent termination of cell division upon YgjD depletion. Conclusions Depletion of YgjD protein from growing cells leads to a decrease in cell size that is contingent on (pppGpp, and to a termination of cell division. The combination of single-cell timelapse microscopy and statistical analysis can give detailed insights into the phenotypic consequences of the loss of essential genes, and can thus serve as a new tool to study the function of essential genes.

  1. T cell immune responses in psoriasis.

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    Zohre Jadali

    2014-08-01

    Full Text Available A central role for T cells and their cytokines in the pathogenesis of psoriasis has been proposed; however, there are controversies over the details of this issue. The goal of this study is to summarise currently available data on the importance of T cells in psoriasis pathogenesis. A systematic review of the English medical literature was conducted by searching PubMed, Embase, ISI Web of Knowledge, and Iranian databases including Iranmedex, and SID for studies on associations between the involvement of T cell subsets and psoriasis. The results of the present study indicate that alterations in the number and function of different subsets of T-cells are associated with psoriasis. It appears that studies on T cell subsets contributed to understanding the immunopathogenesis of psoriasis. In addition, it may have provided novel therapeutic opportunities in ameliorating immunopathologies.

  2. Rituximab efficiently depletes B cells in lung tumors and normal lung tissue [version 1; referees: 2 approved

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    Albane Joly-Battaglini

    2016-01-01

    Full Text Available Rituximab is a monoclonal antibody that targets the CD20 B-cell-specific antigen and is widely used as therapy for B-cell lymphoma. Since rituximab depletes both malignant and normal B cells, it is increasingly being used to treat various conditions in which normal B cells have a pathogenic role, such as rheumatoid arthritis and multiple sclerosis. It is well-established that rituximab efficiently eliminates B cells in blood, lymph nodes, and spleen. In contrast, the effect of rituximab in non-lymphoid tissues remains poorly documented and is debated. Here, we report a rheumatoid arthritis patient who was treated with rituximab before receiving thoracic surgery for non-small cell lung cancer. Using flow cytometry and immunohistochemistry, we show that rituximab efficiently depleted CD20-positive B cells in a primary lung tumor, in lung-associated lymph nodes, and in normal lung tissue. We conclude that rituximab may be very efficient at depleting normal B cells in the lungs. This property of rituximab may potentially be exploited for the treatment of conditions in which pathogenic B cells reside in the lungs. On the other hand, the clearance of lung B cells may provide an explanation for the rare cases of severe non-infectious pulmonary toxicity of rituximab.

  3. Innate lymphoid cell function in the context of adaptive immunity.

    Science.gov (United States)

    Bando, Jennifer K; Colonna, Marco

    2016-06-21

    Innate lymphoid cells (ILCs) are a family of innate immune cells that have diverse functions during homeostasis and disease. Subsets of ILCs have phenotypes that mirror those of polarized helper T cell subsets in their expression of core transcription factors and effector cytokines. Given the similarities between these two classes of lymphocytes, it is important to understand which functions of ILCs are specialized and which are redundant with those of T cells. Here we discuss genetic mouse models that have been used to delineate the contributions of ILCs versus those of T cells and review the current understanding of the specialized in vivo functions of ILCs. PMID:27328008

  4. TH17 cells in tumour immunity and immunotherapy

    OpenAIRE

    Zou, Weiping; Restifo, Nicholas P

    2010-01-01

    T helper 17 (TH17) cells have well-described roles in autoimmune disease. Recent evidence suggests that this effector T cell subset is also involved in tumour immunology and may be a target for cancer therapy. In this Review, we summarize recent findings regarding the nature and relevance of TH17 cells in mouse models of cancer and human disease. We describe the interplay between TH17 cells and other immune cells in the tumour microenvironment, and we assess both the potential antitumorigenic...

  5. Separase phosphosite mutation leads to genome instability and primordial germ cell depletion during oogenesis.

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    Juan Xu

    Full Text Available To ensure equal chromosome segregation and the stability of the genome during cell division, Separase is strictly regulated primarily by Securin binding and inhibitory phosphorylation. By generating a mouse model that contained a mutation to the inhibitory phosphosite of Separase, we demonstrated that mice of both sexes are infertile. We showed that Separase deregulation leads to chromosome mis-segregation, genome instability, and eventually apoptosis of primordial germ cells (PGCs during embryonic oogenesis. Although the PGCs of mutant male mice were completely depleted, a population of PGCs from mutant females survived Separase deregulation. The surviving PGCs completed oogenesis but produced deficient initial follicles. These results indicate a sexual dimorphism effect on PGCs from Separase deregulation, which may be correlated with a gender-specific discrepancy of Securin. Our results reveal that Separase phospho-regulation is critical for genome stability in oogenesis. Furthermore, we provided the first evidence of a pre-zygotic mitotic chromosome segregation error resulting from Separase deregulation, whose sex-specific differences may be a reason for the sexual dimorphism of aneuploidy in gametogenesis.

  6. Role of thymic epithelial cells in lymphoid depletion after experimental infection with the noncytopathogenic BVDV1 strain 7443.

    Science.gov (United States)

    Raya, A I; Gomez-Villamandos, J C; Bautista, M J

    2015-03-01

    Thymic epithelial cells could play an important role in lymphoid depletion during bovine viral diarrhea virus (BVDV) infection. To evaluate this hypothesis, we examined proliferation of lymphocytes, expression of cytokeratins by thymic epithelial cells, and ultrastructural features at sequential time points after experimental infection of colostrum-deprived calves with the noncytopathogenic BVDV1 strain 7443. Ten clinically healthy Friesian calves were used. Eight were inoculated with the virus, and 2 were used as uninfected controls. Calves were sedated and euthanized in batches between 3 and 14 days postinoculation. At necropsy, thymus samples were collected for structural, immunohistochemical, and ultrastructural study. Thymic lymphoid depletion was accompanied by a decrease in lymphocyte proliferation and immunohistochemical and ultrastructural changes in thymic epithelial cells. Immunohistochemical and ultrastructural results reflect a disturbance of the thymic epithelial cell network, which may explain the decrease in lymphocyte proliferation by defective thymocyte-epithelial cell interactions. PMID:24842487

  7. Biomarkers of CD4+ CTL cell Mediated Immunity to Tuberculosis

    Science.gov (United States)

    The immune responses mediated by interactions between T-lymphocyte subsets and mycobacteria-infected macrophages are critical for control of tuberculosis. In these studies, the bovine model was used to characterize the cytolytic and mycobactericidal CD4+ T cell response induced by BCG vaccination. ...

  8. Two-photon polymerization of immune cell scaffolds

    DEFF Research Database (Denmark)

    Olsen, Mark Holm

    Cancer is the leading cause of mortality in the developed world despite major advances in therapy in recent years. Recently cancer immune therapies have developed into promising treatments against a number of cancer types. One of the most promising is dendritic cell based cancer immunotherapy. One...

  9. Evasion of T cell immunity by Epstein-Barr virus

    NARCIS (Netherlands)

    Horst, D.

    2011-01-01

    Immune evasion strategies are thought to contribute essentially to the life cycle of persistent viruses by delaying the elimination of the infected cell long enough to enable the virus to replicate. Exemplary in this context are the herpesviruses, large DNA viruses that are carried as a persistent a

  10. Signal transduction in cells of the immune system in microgravity

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    Huber Kathrin

    2008-10-01

    Full Text Available Abstract Life on Earth developed in the presence and under the constant influence of gravity. Gravity has been present during the entire evolution, from the first organic molecule to mammals and humans. Modern research revealed clearly that gravity is important, probably indispensable for the function of living systems, from unicellular organisms to men. Thus, gravity research is no more or less a fundamental question about the conditions of life on Earth. Since the first space missions and supported thereafter by a multitude of space and ground-based experiments, it is well known that immune cell function is severely suppressed in microgravity, which renders the cells of the immune system an ideal model organism to investigate the influence of gravity on the cellular and molecular level. Here we review the current knowledge about the question, if and how cellular signal transduction depends on the existence of gravity, with special focus on cells of the immune system. Since immune cell function is fundamental to keep the organism under imnological surveillance during the defence against pathogens, to investigate the effects and possible molecular mechanisms of altered gravity is indispensable for long-term space flights to Earth Moon or Mars. Thus, understanding the impact of gravity on cellular functions on Earth will provide not only important informations about the development of life on Earth, but also for therapeutic and preventive strategies to cope successfully with medical problems during space exploration.

  11. Inducible cell death in plant immunity

    DEFF Research Database (Denmark)

    Hofius, Daniel; Tsitsigiannis, Dimitrios I; Jones, Jonathan D G;

    2006-01-01

    Programmed cell death (PCD) occurs during vegetative and reproductive plant growth, as typified by autumnal leaf senescence and the terminal differentiation of the endosperm of cereals which provide our major source of food. PCD also occurs in response to environmental stress and pathogen attack......, and these inducible PCD forms are intensively studied due their experimental tractability. In general, evidence exists for plant cell death pathways which have similarities to the apoptotic, autophagic and necrotic forms described in yeast and metazoans. Recent research aiming to understand these pathways...... and their molecular components in plants are reviewed here....

  12. Inhibitory effect of Polo-like kinase 1 depletion on mitosis and apoptosis of gastric cancer cells

    Institute of Scientific and Technical Information of China (English)

    Xue-Hua Chen; Bin Lan; Ying Qu; Xiao-Qing Zhang; Qu Cai; Bing-Ya Liu; Zheng-Gang Zhu

    2006-01-01

    AIM: Polo-like kinase 1 (PLK1) serine/threonine kinase plays a vital role in multiple phases of mitosis in gastric cancer cells. To investigate the effect of PLK1 depletion on mitosis and apoptosis of gastric cancer cells.METHODS: PLK1 expression was blocked by small RNA interference(siRNA). The expression levels of PLK1, cdc2, cyclin B and caspase 3 were detected by Western blotting. Then, PLK1 depletion, cdc2 activity,cell proliferation, cell cycle phase distribution, mitotic spindle structure, and the rate of apoptosis of the PLK1knockdown cells were observed.RESULTS: PLK1 gene knockdown was associated with increased cyclin B expression, increased cdc2 activity (but not with the expression levels), accumulation of gastric cancer cells at G2/M, improper mitotic spindle formation,delayed chromosome separation and delayed or arrested cytokinesis. Moreover, PLK1 depletion in gastric cancer cells was associated with decreased proliferation,attenuated pro-caspase 3 levels and increased apoptosis.CONCLUSION: Blockage of PLK1 expression may lead to decreased mitosis or even apoptosis in gastric cancer cells, indicating that PLK1 may be a valuable therapeutic target for gastric cancer.

  13. Glioblastoma formation from cell population depleted of Prominin1-expressing cells.

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    Kenji Nishide

    Full Text Available Prominin1 (Prom1, also known as CD133 in human has been widely used as a marker for cancer stem cells (CSCs, which self-renew and are tumorigenic, in malignant tumors including glioblastoma multiforme (GBM. However, there is other evidence showing that Prom1-negative cancer cells also form tumors in vivo. Thus it remains controversial whether Prom1 is a bona fide marker for CSCs. To verify if Prom1-expressing cells are essential for tumorigenesis, we established a mouse line, whose Prom1-expressing cells can be eliminated conditionally by a Cre-inducible DTA gene on the Prom1 locus together with a tamoxifen-inducible CreER(TM, and generated glioma-initiating cells (GICs-LD by overexpressing both the SV40 Large T antigen and an oncogenic H-Ras(L61 in neural stem cells of the mouse line. We show here that the tamoxifen-treated GICs-LD (GICs-DTA form tumor-spheres in culture and transplantable GBM in vivo. Thus, our studies demonstrate that Prom1-expressing cells are dispensable for gliomagenesis in this mouse model.

  14. Relationship between regulatory T cells and immune activation in human immunodeficiency virus-infected patients interrupting antiretroviral therapy.

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    Laurence Weiss

    Full Text Available UNLABELLED: Persistent immune activation plays a central role in driving Human Immunodeficiency Virus (HIV disease progression. Whether CD4+CD25+ regulatory T cells (Tregs are harmful by suppressing HIV-specific immune responses and/or beneficial through a decrease in immune activation remains debatable. We analysed the relationship between proportion and number of regulatory T cells (Tregs and immune activation in HIV-infected patients interrupting an effective antiretroviral therapy (ART. Twenty-five patients were included in a substudy of a prospective multicenter trial of treatment interruption (TI (ANRS 116. Proportions and numbers of Tregs and the proportion of activated CD4 and CD8 T cells were assessed at baseline and month 12 (M12 of TI. Specific anti-HIV CD4 and CD8 responses were investigated at baseline and M12. Non parametric univariate analyses and multivariate linear regression models were conducted. At baseline, the proportion of Tregs negatively correlated with the proportion of HLA-DR+CD8+T cells (r=-0.519. Following TI, the proportion of Tregs increased from 6.3% to 7.2% (p=0.029; absolute numbers of Tregs decreased. The increase in the proportion of HLA-DR+CD38+CD8+T cells was significantly related to the increase in proportion of Tregs (p=0.031. At M12, the proportion of Tregs did not negatively correlate with CD8 T-cell activation. Nevertheless, Tregs retain a suppressive function since depletion of Treg-containing CD4+CD25+ cells led to an increase in lymphoproliferative responses in most patients studied. Our data suggest that Tregs are efficient in controlling residual immune activation in patients with ART-mediated viral suppression. However, the insufficient increase in the proportion and/or the decrease in the absolute number of Tregs result in a failure to control immune activation following TI. TRIAL REGISTRATION: ClinicalTrials.gov NCT00118677.

  15. RNAi mediated acute depletion of Retinoblastoma protein (pRb promotes aneuploidy in human primary cells via micronuclei formation

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    Iovino Flora

    2009-11-01

    Full Text Available Abstract Background Changes in chromosome number or structure as well as supernumerary centrosomes and multipolar mitoses are commonly observed in human tumors. Thus, centrosome amplification and mitotic checkpoint dysfunctions are believed possible causes of chromosomal instability. The Retinoblastoma tumor suppressor (RB participates in the regulation of synchrony between DNA synthesis and centrosome duplication and it is involved in transcription regulation of some mitotic genes. Primary human fibroblasts were transfected transiently with short interfering RNA (siRNA specific for human pRb to investigate the effects of pRb acute loss on chromosomal stability. Results Acutely pRb-depleted fibroblasts showed altered expression of genes necessary for cell cycle progression, centrosome homeostasis, kinetochore and mitotic checkpoint proteins. Despite altered expression of genes involved in the Spindle Assembly Checkpoint (SAC the checkpoint seemed to function properly in pRb-depleted fibroblasts. In particular AURORA-A and PLK1 overexpression suggested that these two genes might have a role in the observed genomic instability. However, when they were post-transcriptionally silenced in pRb-depleted fibroblasts we did not observe reduction in the number of aneuploid cells. This finding suggests that overexpression of these two genes did not contribute to genomic instability triggered by RB acute loss although it affected cell proliferation. Acutely pRb-depleted human fibroblasts showed the presence of micronuclei containing whole chromosomes besides the presence of supernumerary centrosomes and aneuploidy. Conclusion Here we show for the first time that RB acute loss triggers centrosome amplification and aneuploidy in human primary fibroblasts. Altogether, our results suggest that pRb-depleted primary human fibroblasts possess an intact spindle checkpoint and that micronuclei, likely caused by mis-attached kinetochores that in turn trigger

  16. Differential protective effects of immune lymphoid cells against transplanted line Ib leukemia and immune polioencephalomyelitis. [X radiation, mice

    Energy Technology Data Exchange (ETDEWEB)

    Duffey, P.S.; Lukasewycz, O.A.; Olson, D.S.; Murphy, W.H.

    1978-12-01

    The capacity of immune cells obtained from the major lymphoid compartments to protect C58 mice from transplanted line Ib leukemia, and from an age-dependent autoimmune CNS disease (immune polioencephalomyelitis = IPE) elicited by immunizing old C58 mice with inactivated Ib cells was quantified. Cells used for comparative adoptive protection tests were harvested from the major lymphoid compartments 14 to 15 days after young C58 mice were immunized with inactivated Ib cell preparations. Regression curves were plotted from survival data and the log/sub 10/PD/sub 50/ values were determined. Immune spleen (ISC) and peritoneal cells (IPEC) were significantly more protective against transplanted Ib cells than immune lymph node (ILNC), thymic (ITC), and marrow cells (IMC). In contrast, IPEC and IMC were not protective against IPE and ITC were only marginally protective. ILNC afforded significant protection to transplantable leukemia but were only marginally protective to IPE. When ISC were treated with anti-thy 1.2 serum and complement, protection against transplanted leukemia and IPE was reduced > 99%. When donors of immune lymphoid cells were treated with 12.5 mg of cortisone acetate daily for 2 days before lymphoid cells were harvested, protection against transplanted Ib cells by ISC was reduced by approximately 90% whereas protection against IPE was totally eliminated. Considered together, these results indicate that the protective mechanisms to transplantable leukemia and IPE differ significantly in the same indicator mouse strain.

  17. Dynamics of Lymphocyte Populations during Trypanosoma cruzi Infection: From Thymocyte Depletion to Differential Cell Expansion/Contraction in Peripheral Lymphoid Organs

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    Alexandre Morrot

    2012-01-01

    Full Text Available The comprehension of the immune responses in infectious diseases is crucial for developing novel therapeutic strategies. Here, we review current findings on the dynamics of lymphocyte subpopulations following experimental acute infection by Trypanosoma cruzi, the causative agent of Chagas disease. In the thymus, although the negative selection process of the T-cell repertoire remains operational, there is a massive thymocyte depletion and abnormal release of immature CD4+CD8+ cells to peripheral lymphoid organs, where they acquire an activated phenotype similar to activated effector or memory T cells. These cells apparently bypassed the negative selection process, and some of them are potentially autoimmune. In infected animals, an atrophy of mesenteric lymph nodes is also observed, in contrast with the lymphocyte expansion in spleen and subcutaneous lymph nodes, illustrating a complex and organ specific dynamics of lymphocyte subpopulations. Accordingly, T- and B-cell activation is seen in subcutaneous lymph nodes and spleen, but not in mesenteric lymph nodes. Lastly, although the function of peripheral CD4+CD8+ T-cell population remains to be defined in vivo, their presence may contribute to the immunopathological events found in both murine and human Chagas disease.

  18. Regulatory T Cells, a Potent Immunoregulatory Target for CAM Researchers: Modulating Tumor Immunity, Autoimmunity and Alloreactive Immunity (III

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    Aristo Vojdani

    2006-01-01

    Full Text Available Regulatory T (Treg cells are the major arbiter of immune responses, mediating actions through the suppression of inflammatory and destructive immune reactions. Inappropriate Treg cell frequency or functionality potentiates the pathogenesis of myriad diseases with ranging magnitudes of severity. Lack of suppressive capability hinders restraint on immune responses involved in autoimmunity and alloreactivity, while excessive suppressive capacity effectively blocks processes necessary for tumor destruction. Although the etiology of dysfunctional Treg cell populations is under debate, the ramifications, and their mechanisms, are increasingly brought to light in the medical community. Methods that compensate for aberrant immune regulation may not address the underlying complications; however, they hold promise for the alleviation of debilitating immune system-related disorders. The dominant immunoregulatory nature of Treg cells, coupled with recent mechanistic knowledge of natural immunomodulatory compounds, highlights the importance of Treg cells to practitioners and researchers of complementary and alternative medicine (CAM.

  19. Cell mechanics and immune system link up to fight infections

    Science.gov (United States)

    Ekpenyong, Andrew; Man, Si Ming; Tourlomousis, Panagiotis; Achouri, Sarra; Cammarota, Eugenia; Hughes, Katherine; Rizzo, Alessandro; Ng, Gilbert; Guck, Jochen; Bryant, Clare

    2015-03-01

    Infectious diseases, in which pathogens invade and colonize host cells, are responsible for one third of all mortality worldwide. Host cells use special proteins (immunoproteins) and other molecules to fight viral and bacterial invaders. The mechanisms by which immunoproteins enable cells to reduce bacterial loads and survive infections remain unclear. Moreover, during infections, some immunoproteins are known to alter the cytoskeleton, the structure that largely determines cellular mechanical properties. We therefore used an optical stretcher to measure the mechanical properties of primary immune cells (bone marrow derived macrophages) during bacterial infection. We found that macrophages become stiffer upon infection. Remarkably, macrophages lacking the immunoprotein, NLR-C4, lost the stiffening response to infection. This in vitro result correlates with our in vivo data whereby mice lacking NLR-C4 have more lesions and hence increased bacterial distribution and spread. Thus, the immune-protein-dependent increase in cell stiffness in response to bacterial infection (in vitro result) seems to have a functional role in the system level fight against pathogens (in vivo result). We will discuss how this functional link between cell mechanical properties and innate immunity, effected by actin polymerization, reduces the spread of infection.

  20. Generation of antigen-specific T cell immunity through T cell receptor gene transfer

    NARCIS (Netherlands)

    Coccoris, Miriam

    2009-01-01

    Cancer cells often escape the attack of immune cells because they originate from self-tissue. Through T cell receptor gene transfer it is possible to equip peripheral T cells with a desired specificity, and this strategy may be useful to generate tumor-specific T cells for the treatment of cancer in

  1. Emerging Evidence for Platelets as Immune and Inflammatory Effector Cells

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    Matthew Thomas Rondina

    2014-12-01

    Full Text Available While traditionally recognized for their roles in hemostatic pathways, emerging evidence demonstrates that platelets have previously unrecognized, dynamic roles that span the immune continuum. These newly-recognized platelet functions, including the secretion of immune mediators, interactions with endothelial cells, monocytes, and neutrophils, toll-like receptor (TLR mediated responses, and induction of neutrophil extracellular trap (NET formation, bridge thrombotic and inflammatory pathways and contribute to host defense mechanisms against invading pathogens. In this focused review, we highlight several of these emerging aspects of platelet biology and their implications in clinical infectious syndromes.

  2. Specific Control of Immunity by Regulatory CD8 T Cells

    Institute of Scientific and Technical Information of China (English)

    XiaoleiTang; TrevorRFSmith

    2005-01-01

    T lymphocytes with dedicated suppressor function (Treg) play a crucial role in the homeostatic control of immunity in the periphery. Several Treg phenotypes have now been identified in the CD4 and CD8 T cell populations, suggesting their down-regulatory function in both human and animal models of autoimmunity, transplantation and tumor immunity. Here we will focus on the CD8 Treg population and their ability to specifically inhibit a pathogenic autoimmune response. This review will detail the current advances in the knowledge of CD8 Treg in the context of antigen specificity, phenotype, MHC restriction, mechanism of action, and priming. Cellular & Molecular Immunology. 2005;2(1):11-19.

  3. Role of Dendritic Cells in Immune Dysfunction

    Science.gov (United States)

    Savary, Cherylyn A.

    1997-01-01

    Specific aims include: (1) Application of the bioreactor to enhance cytokine-regulated proliferation and maturation of dendritic cells (DC); (2) Based on clues from spaceflight: compare the frequency and function of DC in normal donors and immunocompromised cancer patients; and (3) Initiate studies on the efficiency of cytokine therapy and DC-assisted immunotherapy (using bioreactor-expanded DC) in animal models of experimental fungal infections.

  4. Tissue specific heterogeneity in effector immune cell response

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    Saba eTufail

    2013-08-01

    Full Text Available Post pathogen invasion, migration of effector T-cell subsets to specific tissue locations is of prime importance for generation of robust immune response. Effector T cells are imprinted with distinct ‘homing codes’ (adhesion molecules and chemokine receptors during activation which regulate their targeted trafficking to specific tissues. Internal cues in the lymph node microenvironment along with external stimuli from food (vitamin A and sunlight (vitamin D3 prime dendritic cells, imprinting them to play centrestage in the induction of tissue tropism in effector T cells. B cells as well, in a manner similar to effector T cells, exhibit tissue tropic migration. In this review, we have focused on the factors regulating the generation and migration of effector T cells to various tissues alongwith giving an overview of tissue tropism in B cells.

  5. Beta-glucan-depleted, glycopeptide-rich extracts from Brewer's and Baker's yeast (Saccharomyces cerevisiae) lower interferon-gamma production by stimulated human blood cells in vitro.

    Science.gov (United States)

    Williams, Roderick; Dias, Daniel A; Jayasinghe, Nirupama; Roessner, Ute; Bennett, Louise E

    2016-04-15

    Regulation of the human immune system requires controlled pro- and anti-inflammatory responses for host defence against infection and disease states. Yeasts (Saccharomyces cerevisiae), as used in brewing and baking, are mostly known for ability to stimulate the human immune-system predominantly reflecting the pro-inflammatory cell wall β-glucans. However, in this study, using food-compatible processing methods, glycopeptide-enriched and β-glucan-depleted products were each prepared from Brewer's and Baker's yeasts, which suppressed production of interferon-γ (IFN-γ) in human whole blood cell assay, signifying that anti-inflammatory factors are also present in yeast. Anti-inflammatory bioactivities of products prepared from Brewer's and Baker's yeast were compared with the commercial yeast product, Epicor®. While unfractionated Epicor was inactive, the C18 resin-binding fractions of Brewer's and Baker's yeast products and Epicor dose-dependently lowered IFN-γ, demonstrating that Epicor also contained both pro-inflammatory (β-glucans) and anti-inflammatory components. Anti-inflammatory activity was attributed to C18 resin-binding species glyco-peptides in Epicor and experimental yeast products. This study demonstrated that pro- and anti-inflammatory factors could be resolved and enriched in yeasts by suitable processing, with potential to improve specific activities.

  6. Genetic variants regulating immune cell levels in health and disease.

    Science.gov (United States)

    Orrù, Valeria; Steri, Maristella; Sole, Gabriella; Sidore, Carlo; Virdis, Francesca; Dei, Mariano; Lai, Sandra; Zoledziewska, Magdalena; Busonero, Fabio; Mulas, Antonella; Floris, Matteo; Mentzen, Wieslawa I; Urru, Silvana A M; Olla, Stefania; Marongiu, Michele; Piras, Maria G; Lobina, Monia; Maschio, Andrea; Pitzalis, Maristella; Urru, Maria F; Marcelli, Marco; Cusano, Roberto; Deidda, Francesca; Serra, Valentina; Oppo, Manuela; Pilu, Rosella; Reinier, Frederic; Berutti, Riccardo; Pireddu, Luca; Zara, Ilenia; Porcu, Eleonora; Kwong, Alan; Brennan, Christine; Tarrier, Brendan; Lyons, Robert; Kang, Hyun M; Uzzau, Sergio; Atzeni, Rossano; Valentini, Maria; Firinu, Davide; Leoni, Lidia; Rotta, Gianluca; Naitza, Silvia; Angius, Andrea; Congia, Mauro; Whalen, Michael B; Jones, Chris M; Schlessinger, David; Abecasis, Gonçalo R; Fiorillo, Edoardo; Sanna, Serena; Cucca, Francesco

    2013-09-26

    The complex network of specialized cells and molecules in the immune system has evolved to defend against pathogens, but inadvertent immune system attacks on "self" result in autoimmune disease. Both genetic regulation of immune cell levels and their relationships with autoimmunity are largely undetermined. Here, we report genetic contributions to quantitative levels of 95 cell types encompassing 272 immune traits, in a cohort of 1,629 individuals from four clustered Sardinian villages. We first estimated trait heritability, showing that it can be substantial, accounting for up to 87% of the variance (mean 41%). Next, by assessing ∼8.2 million variants that we identified and confirmed in an extended set of 2,870 individuals, 23 independent variants at 13 loci associated with at least one trait. Notably, variants at three loci (HLA, IL2RA, and SH2B3/ATXN2) overlap with known autoimmune disease associations. These results connect specific cellular phenotypes to specific genetic variants, helping to explicate their involvement in disease. PMID:24074872

  7. Isocitrate Dehydrogenase 2 Dysfunction Contributes to 5-hydroxymethylcytosine Depletion in Gastric Cancer Cells.

    Science.gov (United States)

    Chou, Nan-Hua; Tsai, Chung-Yu; Tu, Ya-Ting; Wang, Kuo-Chiang; Kang, Chi-Hsiang; Chang, Po-Min; Li, Guan-Cheng; Lam, Hing-Chung; Liu, Shiuh-Inn; Tsai, Kuo-Wang

    2016-08-01

    The isocitrate dehydrogenase (IDH) family of enzymes comprises of the key functional metabolic enzymes in the Krebs cycle that catalyze the conversion of isocitrate to α-ketoglutarate (α-KG). α-KG acts as a cofactor in the conversion of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC). However, the relationship between 5hmC and IDH in gastric cancer remains unclear. Our study revealed that the 5hmC level was substantially lower and 5mC level was slightly higher in gastric cancer tissues; however, 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC) levels did not change significantly in these tissues. We further examined the expression levels of IDH1 and IDH2 in gastric cancer tissues and observed that IDH2 levels were significantly lower in gastric cancer tissues than in the adjacent normal tissues. The ectopic expression of IDH2 can increase 5hmC levels in gastric cancer cells. In conclusion, our results suggested that IDH2 dysfunction is involved in 5hmC depletion during gastric cancer progression. PMID:27466503

  8. Histone deacetylase 3 depletion in osteo/chondroprogenitor cells decreases bone density and increases marrow fat.

    Directory of Open Access Journals (Sweden)

    David F Razidlo

    Full Text Available Histone deacetylase (Hdac3 is a nuclear enzyme that contributes to epigenetic programming and is required for embryonic development. To determine the role of Hdac3 in bone formation, we crossed mice harboring loxP sites around exon 7 of Hdac3 with mice expressing Cre recombinase under the control of the osterix promoter. The resulting Hdac3 conditional knockout (CKO mice were runted and had severe deficits in intramembranous and endochondral bone formation. Calvarial bones were significantly thinner and trabecular bone volume in the distal femur was decreased 75% in the Hdac3 CKO mice due to a substantial reduction in trabecular number. Hdac3-CKO mice had fewer osteoblasts and more bone marrow adipocytes as a proportion of tissue area than their wildtype or heterozygous littermates. Bone formation rates were depressed in both the cortical and trabecular regions of Hdac3 CKO femurs. Microarray analyses revealed that numerous developmental signaling pathways were affected by Hdac3-deficiency. Thus, Hdac3 depletion in osterix-expressing progenitor cells interferes with bone formation and promotes bone marrow adipocyte differentiation. These results demonstrate that Hdac3 inhibition is detrimental to skeletal health.

  9. Breakdown of Immune Tolerance in Systemic Lupus Erythematosus by Dendritic Cells.

    Science.gov (United States)

    Liao, Xiaofeng; Reihl, Alec M; Luo, Xin 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

  10. Distinct Mechanisms of Ferritin Delivery to Lysosomes in Iron-Depleted and Iron-Replete Cells

    OpenAIRE

    Asano, Takeshi; Komatsu, Masaaki; Yamaguchi-Iwai, Yuko; Ishikawa, Fuyuki; Mizushima, Noboru; Iwai, Kazuhiro

    2011-01-01

    Ferritin is a cytosolic protein that stores excess iron, thereby protecting cells from iron toxicity. Ferritin-stored iron is believed to be utilized when cells become iron deficient; however, the mechanisms underlying the extraction of iron from ferritin have yet to be fully elucidated. Here, we demonstrate that ferritin is degraded in the lysosome under iron-depleted conditions and that the acidic environment of the lysosome is crucial for iron extraction from ferritin and utilization by ce...

  11. Depletion of neural stem cells from the subventricular zone of adult mouse brain using cytosine b‐Arabinofuranoside

    OpenAIRE

    Ghanbari, Amir; Esmaeilpour, Tahereh; Bahmanpour, Soghra; Golmohammadi, Mohammad Ghasem; Sharififar, Sharareh; Azari, Hassan

    2015-01-01

    Abstract Introduction Neural stem cells (NSCs) reside along the ventricular axis of the mammalian brain. They divide infrequently to maintain themselves and the down‐stream progenitors. Due to the quiescent property of NSCs, attempts to deplete these cells using antimitotic agents such as cytosine b‐Aarabinofuranoside (Ara‐C) have not been successful. We hypothesized that implementing infusion gaps in Ara‐C kill paradigms would recruit the quiescent NSCs and subsequently eliminate them from t...

  12. Novel immune modulators used in hematology: impact on NK cells.

    Science.gov (United States)

    Krieg, Stephanie; Ullrich, Evelyn

    2012-01-01

    There is a wide range of important pharmaceuticals used in treatment of cancer. Besides their known effects on tumor cells, there is growing evidence for modulation of the immune system. Immunomodulatory drugs (IMiDs(®)) play an important role in the treatment of patients with multiple myeloma or myelodysplastic syndrome and have already demonstrated antitumor, anti-angiogenic, and immunostimulating effects, in particular on natural killer (NK) cells. Tyrosine kinase inhibitors are directly targeting different kinases and are known to regulate effector NK cells and expression of NKG2D ligands (NKG2DLs) on tumor cells. Demethylating agents, histone deacetylases, and proteasome inhibitors interfere with the epigenetic regulation and protein degradation of malignant cells. There are first hints that these drugs also sensitize tumor cells to chemotherapy, radiation, and NK cell-mediated cytotoxicity by enhanced expression of TRAIL and NKG2DLs. However, these pharmaceuticals may also impair NK cell function in a dose- and time-dependent manner. In summary, this review provides an update on the effects of different novel molecules on the immune system focusing NK cells. PMID:23316191

  13. Iron depletion results in Src kinase inhibition with associated cell cycle arrest in neuroblastoma cells.

    Science.gov (United States)

    Siriwardana, Gamini; Seligman, Paul A

    2015-03-01

    Iron is required for cellular proliferation. Recently, using systematic time studies of neuroblastoma cell growth, we better defined the G1 arrest caused by iron chelation to a point in mid-G1, where cyclin E protein is present, but the cyclin E/CDK2 complex kinase activity is inhibited. In this study, we again used the neuroblastoma SKNSH cells lines to pinpoint the mechanism responsible for this G1 block. Initial studies showed in the presence of DFO, these cells have high levels of p27 and after reversal of iron chelation p27 is degraded allowing for CDK2 kinase activity. The initial activation of CDK2 kinase allows cells to exit G1 and enter S phase. Furthermore, we found that inhibition of p27 degradation by DFO is directly associated with inhibition of Src kinase activity measured by lack of phosphorylation of Src at the 416 residue. Activation of Src kinase occurs very early after reversal from the DFO G1 block and is temporally associated with initiation of cellular proliferation associated with entry into S phase. For the first time therefore we show that iron chelation inhibits Src kinase activity and this activity is a requirement for cellular proliferation. PMID:25825542

  14. Iron depletion results in Src kinase inhibition with associated cell cycle arrest in neuroblastoma cells.

    Science.gov (United States)

    Siriwardana, Gamini; Seligman, Paul A

    2015-03-01

    Iron is required for cellular proliferation. Recently, using systematic time studies of neuroblastoma cell growth, we better defined the G1 arrest caused by iron chelation to a point in mid-G1, where cyclin E protein is present, but the cyclin E/CDK2 complex kinase activity is inhibited. In this study, we again used the neuroblastoma SKNSH cells lines to pinpoint the mechanism responsible for this G1 block. Initial studies showed in the presence of DFO, these cells have high levels of p27 and after reversal of iron chelation p27 is degraded allowing for CDK2 kinase activity. The initial activation of CDK2 kinase allows cells to exit G1 and enter S phase. Furthermore, we found that inhibition of p27 degradation by DFO is directly associated with inhibition of Src kinase activity measured by lack of phosphorylation of Src at the 416 residue. Activation of Src kinase occurs very early after reversal from the DFO G1 block and is temporally associated with initiation of cellular proliferation associated with entry into S phase. For the first time therefore we show that iron chelation inhibits Src kinase activity and this activity is a requirement for cellular proliferation.

  15. T regulatory cells and their counterparts: masters of immune regulation.

    Science.gov (United States)

    Ozdemir, C; Akdis, M; Akdis, C A

    2009-05-01

    The interaction of environmental and genetic factors with the immune system can lead to the development of allergic diseases. The essential step in this progress is the generation of allergen-specific CD4(+) T-helper (Th) type 2 cells that mediate several effector functions. The influence of Th2 cytokines leads to the production of allergen-specific IgE antibodies by B cells, development and recruitment of eosinophils, mucus production and bronchial hyperreactivity, as well as tissue homing of other Th2 cells and eosinophils. Meanwhile, Th1 cells may contribute to chronicity and the effector phases. T cells termed T regulatory (Treg) cells, which have immunosuppressive functions and cytokine profiles distinct from that of either Th1 or Th2 cells, have been intensely investigated during the last 13 years. Treg cell response is characterized by an abolished allergen-specific T cell proliferation and the suppressed secretion of Th1 and Th2-type cytokines. Treg cells are able to inhibit the development of allergen-specific Th2 and Th1 cell responses and therefore play an important role in a healthy immune response to allergens. In addition, Treg cells potently suppress IgE production and directly or indirectly suppress the activity of effector cells of allergic inflammation, such as eosinophils, basophils and mast cells. Currently, Treg cells represent an exciting area of research, where understanding the mechanisms of peripheral tolerance to allergens may soon lead to more rational and safer approaches for the prevention and cure of allergic diseases. PMID:19422105

  16. shRNA Depletion of cIAP1 Sensitizes Human Ovarian Cancer Cells to Anticancer Agent-Induced Apoptosis.

    Science.gov (United States)

    Jin, Hong; Dong, You-Yuan; Zhang, Hong; Cui, Ying; Xie, Kai; Lou, Ge

    2014-01-01

    Emerging evidence suggests a potential role of cellular inhibitor of apoptosis protein 1 (cIAP1) in the development of human ovarian cancer. However, its function in the progression of ovarian cancer has not been clearly determined. Our study aimed to investigate the effect of cIAP1 gene depletion on the chemosensitivity of ovarian cancer cells. We developed a novel short hairpin RNA (shRNA) plasmid specifically targeting cIAP1. Cell proliferation, invasion, and apoptosis of the shRNA-transfected cells were evaluated using MTT, Transwell chamber, and flow cytometric assays, respectively. The concentration of MMP-9 in the supernatant was detected by ELISA. Targeted depletion of cIAP1 by shRNA significantly reduced expression levels of cIAP1 mRNA and protein, leading to inhibition of cell proliferation and invasion capability in SKOV3 cells. At the same time, cIAP1 downregulation decreased the secretion of MMP-9. shRNA depletion of cIAP1 enhanced chemosensitivity of ovarian cancer cells to Taxol and carboplatin-induced apoptosis. cIAP1 is associated with tumor progression in human ovarian cancer. Therefore, cIAP1 might be a potential target for therapeutic anticancer drugs. PMID:26168135

  17. Identifying genes that mediate anthracyline toxicity in immune cells

    Directory of Open Access Journals (Sweden)

    Amber eFrick

    2015-04-01

    Full Text Available The role of the immune system in response to chemotherapeutic agents remains elusive. The interpatient variability observed in immune and chemotherapeutic cytotoxic responses is likely, at least in part, due to complex genetic differences. Through the use of a panel of genetically diverse mouse inbred strains, we developed a drug screening platform aimed at identifying genes underlying these chemotherapeutic cytotoxic effects on immune cells. Using genome-wide association studies (GWAS, we identified four genome-wide significant quantitative trait loci (QTL that contributed to the sensitivity of doxorubicin and idarubicin in immune cells. Of particular interest, a locus on chromosome 16 was significantly associated with cell viability following idarubicin administration (p = 5.01x10-8. Within this QTL lies App, which encodes amyloid beta precursor protein. Comparison of dose-response curves verified that T-cells in App knockout mice were more sensitive to idarubicin than those of C57BL/6J control mice (p < 0.05.In conclusion, the cellular screening approach coupled with GWAS led to the identification and subsequent validation of a gene involved in T-cell viability after idarubicin treatment. Previous studies have suggested a role for App in in vitro and in vivo cytotoxicity to anticancer agents; the overexpression of App enhances resistance, while the knockdown of this gene is deleterious to cell viability. Thus, further investigations should include performing mechanistic studies, validating additional genes from the GWAS, including Ppfia1 and Ppfibp1, and ultimately translating the findings to in vivo and human studies.

  18. Mast cells in allergy and autoimmunity: implications for adaptive immunity.

    Science.gov (United States)

    Gregory, Gregory D; Brown, Melissa A

    2006-01-01

    As in the fashion industry, trends in a particular area of scientific investigation often are fleeting but then return with renewed and enthusiastic interest. Studies of mast cell biology are good examples of this. Although dogma once relegated mast cells almost exclusively to roles in pathological inflammation associated with allergic disease, these cells are emerging as important players in a number of other physiological processes. Consequently, they are quickly becoming the newest "trendy" cell, both within and outside the field of immunology. As sources of a large array of pro- and anti-inflammatory mediators, mast cells also express cell surface molecules with defined functions in lymphocyte activation and trafficking. Here, we provide an overview of the traditional and newly appreciated contributions of mast cells to both innate and adaptive immune responses.

  19. Iron depletion suppresses mTORC1-directed signalling in intestinal Caco-2 cells via induction of REDD1

    Science.gov (United States)

    Watson, Ailsa; Lipina, Christopher; McArdle, Harry J.; Taylor, Peter M.; Hundal, Harinder S.

    2016-01-01

    Iron is an indispensable micronutrient that regulates many aspects of cell function, including growth and proliferation. These processes are critically dependent upon signalling via the mammalian or mechanistic target of rapamycin complex 1 (mTORC1). Herein, we test whether iron depletion induced by cell incubation with the iron chelator, deferoxamine (DFO), mediates its effects on cell growth through mTORC1-directed signalling and protein synthesis. We have used Caco-2 cells, a well-established in vitro model of human intestinal epithelia. Iron depletion increased expression of iron-regulated proteins (TfR, transferrin receptor and DMT1, divalent metal transporter, as predicted, but it also promoted a marked reduction in growth and proliferation of Caco-2 cells. This was strongly associated with suppressed mTORC1 signalling, as judged by reduced phosphorylation of mTOR substrates, S6K1 and 4E-BP1, and diminished protein synthesis. The reduction in mTORC1 signalling was tightly coupled with increased expression and accumulation of REDD1 (regulated in DNA damage and development 1) and reduced phosphorylation of Akt and TSC2. The increase in REDD1 abundance was rapidly reversed upon iron repletion of cells but was also attenuated by inhibitors of gene transcription, protein phosphatase 2A (PP2A) and by REDD1 siRNA — strategies that also antagonised the loss in mTORC1 signalling associated with iron depletion. Our findings implicate REDD1 and PP2A as crucial regulators of mTORC1 activity in iron-depleted cells and indicate that their modulation may help mitigate atrophy of the intestinal mucosa that may occur in response to iron deficiency. PMID:26827808

  20. Innate lymphoid cells and natural killer T cells in the gastrointestinal tract immune system

    OpenAIRE

    Enrique Montalvillo; José Antonio Garrote; David Bernardo; Eduardo Arranz

    2014-01-01

    The gastrointestinal tract is equipped with a highly specialized intrinsic immune system. However, the intestine is exposed to a high antigenic burden that requires a fast, nonspecific response -so-called innate immunity- to maintain homeostasis and protect the body from incoming pathogens. In the last decade multiple studies helped to unravel the particular developmental requirements and specific functions of the cells that play a role in innate immunity. In this review we shall focus on inn...

  1. Depletion of polyamines prevents the neurotrophic activity of the GABA-agonist THIP in cultured rat cerebellar granule cells

    DEFF Research Database (Denmark)

    Abraham, J H; Hansen, Gert Helge; Seiler, N;

    1993-01-01

    Effects of polyamine depletion by alpha-difluoromethylornithine (DFMO) were studied on the GABA-agonist mediated enhancement of the morphological development of cultured rat cerebellar granule cells. An increase in the number of neurite extending cells and in the cytoplasmic density of organelles...... morphological development of the granule cell cultures. Thus, the number of neurite extending cells was reduced to 50% of the number in the control cultures upon culturing in the presence of DFMO alone or in combination with THIP. Moreover, the THIP mediated increase in the cytoplasmic density of rough...

  2. Regulatory T cells and the immune pathogenesis of prenatal infection.

    Science.gov (United States)

    Rowe, Jared H; Ertelt, James M; Xin, Lijun; Way, Sing Sing

    2013-12-01

    Pregnancy in placental mammals offers exceptional comprehensive benefits of in utero protection, nutrition, and metabolic waste elimination for the developing fetus. However, these benefits also require durable strategies to mitigate maternal rejection of fetal tissues expressing foreign paternal antigens. Since the initial postulate of expanded maternal immune tolerance by Sir Peter Medawar 60 years ago, an amazingly elaborate assortment of molecular and cellular modifications acting both locally at the maternal-placental interface and systemically have been shown to silence potentially detrimental maternal immune responses. In turn, simultaneously maintaining host defense against the infinite array of potential pathogens during pregnancy is equally important. Fortunately, resistance against most infections is preserved seamlessly throughout gestation. On the other hand, recent studies on pathogens with unique predisposition for prenatal infections have uncovered distinctive holes in host defense associated with the reproductive process. Using these infections to probe the response during pregnancy, the immune suppressive regulatory subset of maternal CD4 T cells has been increasingly shown to dictate the inter-workings between prenatal infection susceptibility and pathogenesis of ensuing pregnancy complications. Herein, the recent literature suggesting a necessity for maternal regulatory T cells (Tregs) in pregnancy-induced immunological shifts that sustain fetal tolerance is reviewed. Additional discussion is focused on how expansion of maternal Treg suppression may become exploited by pathogens that cause prenatal infections and the perilous potential of infection-induced immune activation that may mitigate fetal tolerance and inadvertently inject hostility into the protective in utero environment.

  3. Cell signalling in the immune response of mussel hemocytes

    Directory of Open Access Journals (Sweden)

    L Canesi

    2006-05-01

    Full Text Available In this work data on immune cell signallling in the circulating hemocytes of the edible bivalve, themussel Mytilus spp, are summarized. Studies with different bacterial species and strains, heterologouscytokines and natural hormones, as well as with organic environmental chemicals, led to theidentification of the role of conserved components of kinase-mediated transduction pathways,including cytosolic kinases (such as MAPKs and PKC and kinase-activated transcription factors (suchas STATs, CREB, NF-kB, in the immune response. From these data a general scenario emergedindicating that close similarities exist in the signalling pathways involved in cell mediated immunity inbivalve and mammalian immunocytes. In particular, the results indicate that both the extent andduration of activation of components of kinase-mediated cascades are crucial in determining thehemocyte response to extracellular stimuli. The identification of the basic mechanisms of immunityand its modulation in mussels can give important information for the possible utilization of thesespecies as an invertebrate model for studies on innate immunity. Moreover, the application of thisknowledge to the understanding of the actual adaptive responses of bivalves when exposed to microorganismsin their natural environment can represent significant ecological, economical and publichealth-related interest.

  4. Depletion of Aurora-A in zebrafish causes growth retardation due to mitotic delay and p53-dependent cell death.

    Science.gov (United States)

    Jeon, Hee-Yeon; Lee, Hyunsook

    2013-03-01

    Aurora-A is a serine/threonine mitotic kinase that is required for centrosome maturation. Many cancer cells over-express Aurora-A, and several reports have suggested that Aurora-A has prognostic value in the clinical treatment of cancer. Therefore, inhibitors for Aurora-A kinase have been developed. However, studies on Aurora-A are largely performed in cancer cell lines and are sometimes controversial. For effective evaluation of Aurora-A inhibitors in cancer treatment, it is essential to understand its function at the organism level. Here, we report the crucial functions of Aurora-A in homeostasis of spindle organization in mitosis using zebrafish embryogenesis as a model system. Using morpholino technology, we show that depletion of Aurora-A in zebrafish embryogenesis results in short bent trunks, accompanied by growth retardation and eventual cell death. Live-imaging and immunofluorescence analyses of the embryos revealed that the developmental defects are due to problems in mitosis, manifested through monopolar and disorganized spindle formation. Aurora-A-depleted cells exhibited mitotic arrest with congression failure, leading to activation of the spindle assembly checkpoint. Cell death in the absence of Aurora-A was partially rescued by co-injection of the p53 morpholino, suggesting that apoptosis after Aurora-A depletion is p53-dependent. The clinical implications of these results relate to the indication that Aurora-A inhibitors may be effective towards cancers with intact p53.

  5. Depletion of three combined THOC5 mRNA export protein target genes synergistically induces human hepatocellular carcinoma cell death.

    Science.gov (United States)

    Saran, S; Tran, D D H; Ewald, F; Koch, A; Hoffmann, A; Koch, M; Nashan, B; Tamura, T

    2016-07-21

    Hepatocellular carcinoma (HCC) is a frequent form of cancer with a poor prognosis and with limited possibilities of medical intervention. It has been shown that over 100 putative driver genes are associated with multiple recurrently altered pathways in HCC, suggesting that multiple pathways will need to be inhibited for any therapeutic method. mRNA processing is regulated by a complex RNA-protein network that is essential for the maintenance of homeostasis. THOC5, a member of mRNA export complex, has a role in less than 1% of mRNA processing, and is required for cell growth and differentiation, but not for cell survival in normal fibroblasts, hepatocytes and macrophages. In this report, we show that 50% depletion of THOC5 in human HCC cell lines Huh7 and HepG2 induced apoptosis. Transcriptome analysis using THOC5-depleted cells revealed that 396 genes, such as transmembrane BAX inhibitor motif containing 4 (TMBIM4), transmembrane emp24-like trafficking protein 10 (Tmed10) and D-tyrosyl-tRNA deacylase 2 (Dtd2) genes were downregulated in both cell lines. The depletion of one of these THOC5 target genes in Huh7 or HepG2 did not significantly induce cell death, suggesting that these may be fine tuners for HCC cell survival. However, the depletion of a combination of these genes synergistically increased the number of TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling)-positive HCC. It must be noted that the depletion of these genes did not induce cell death in the hepatocyte cell line, THLE-2 cells. THOC5 expression was enhanced in 78% of cytological differentiation grading G2 and G3 tumor in primary HCC. Furthermore, the expression of a putative glycoprotein, Tmed10, is correlated to THOC5 expression level in primary HCCs, suggesting that this protein may be a novel biomarker for HCC. These data imply that the suppression of the multiple THOC5 target genes may represent a novel strategy for HCC therapy. PMID:26549021

  6. The responses of immune cells to iron oxide nanoparticles.

    Science.gov (United States)

    Xu, Yaolin; Sherwood, Jennifer A; Lackey, Kimberly H; Qin, Ying; Bao, Yuping

    2016-04-01

    Immune cells play an important role in recognizing and removing foreign objects, such as nanoparticles. Among various parameters, surface coatings of nanoparticles are the first contact with biological system, which critically affect nanoparticle interactions. Here, surface coating effects on nanoparticle cellular uptake, toxicity and ability to trigger immune response were evaluated on a human monocyte cell line using iron oxide nanoparticles. The cells were treated with nanoparticles of three types of coatings (negatively charged polyacrylic acid, positively charged polyethylenimine and neutral polyethylene glycol). The cells were treated at various nanoparticle concentrations (5, 10, 20, 30, 50 μg ml(-1) or 2, 4, 8, 12, 20 μg cm(-2)) with 6 h incubation or treated at a nanoparticle concentration of 50 μg ml(-1) (20 μg cm(-2)) at different incubation times (6, 12, 24, 48 or 72 h). Cell viability over 80% was observed for all nanoparticle treatment experiments, regardless of surface coatings, nanoparticle concentrations and incubation times. The much lower cell viability for cells treated with free ligands (e.g. ~10% for polyethylenimine) suggested that the surface coatings were tightly attached to the nanoparticle surfaces. The immune responses of cells to nanoparticles were evaluated by quantifying the expression of toll-like receptor 2 and tumor necrosis factor-α. The expression of tumor necrosis factor-α and toll-like receptor 2 were not significant in any case of the surface coatings, nanoparticle concentrations and incubation times. These results provide useful information to select nanoparticle surface coatings for biological and biomedical applications. PMID:26817529

  7. Intestinal immune homeostasis is regulated by the crosstalk between epithelial cells and dendritic cells.

    Science.gov (United States)

    Rimoldi, Monica; Chieppa, Marcello; Salucci, Valentina; Avogadri, Francesca; Sonzogni, Angelica; Sampietro, Gianluca M; Nespoli, Angelo; Viale, Giuseppe; Allavena, Paola; Rescigno, Maria

    2005-05-01

    The control of damaging inflammation by the mucosal immune system in response to commensal and harmful ingested bacteria is unknown. Here we show epithelial cells conditioned mucosal dendritic cells through the constitutive release of thymic stromal lymphopoietin and other mediators, resulting in the induction of 'noninflammatory' dendritic cells. Epithelial cell-conditioned dendritic cells released interleukins 10 and 6 but not interleukin 12, and they promoted the polarization of T cells toward a 'classical' noninflammatory T helper type 2 response, even after exposure to a T helper type 1-inducing pathogen. This control of immune responses seemed to be lost in patients with Crohn disease. Thus, the intimate interplay between intestinal epithelial cells and dendritic cells may help to maintain gut immune homeostasis. PMID:15821737

  8. Curcumin prevents human dendritic cell response to immune stimulants

    Science.gov (United States)

    Shirley, Shawna A.; Montpetit, Alison J.; Lockey, R.F.; Mohapatra, Shyam S.

    2012-01-01

    Curcumin, a compound found in the Indian spice turmeric, has anti-inflammatory and immunomodulatory properties, though the mechanism remains unclear. Dendritic cells (DCs) are important to generating an immune response and the effect of curcumin on human DCs has not been explored. The role curcumin in the DC response to bacterial and viral infection was investigated in vitro using LPS and Poly I:C as models of infection. CD14+ monocytes, isolated from human peripheral blood, were cultured in GM-CSF- and IL-4-supplemented medium to generate immature DCs. Cultures were incubated with curcumin, stimulated with LPS or Poly I:C and functional assays were performed. Curcumin prevents DCs from responding to immunostimulants and inducing naïve CD4+ T cell proliferation by blocking maturation marker, cytokine and chemokine expression and reducing both migration and endocytosis. These data suggest a therapeutic role for curcumin as an immune suppressant. PMID:18639521

  9. Curcumin prevents human dendritic cell response to immune stimulants

    International Nuclear Information System (INIS)

    Curcumin, a compound found in the Indian spice turmeric, has anti-inflammatory and immunomodulatory properties, though the mechanism remains unclear. Dendritic cells (DCs) are important to generating an immune response and the effect of curcumin on human DCs has not been explored. The role curcumin in the DC response to bacterial and viral infection was investigated in vitro using LPS and Poly I:C as models of infection. CD14+ monocytes, isolated from human peripheral blood, were cultured in GM-CSF- and IL-4-supplemented medium to generate immature DCs. Cultures were incubated with curcumin, stimulated with LPS or Poly I:C and functional assays were performed. Curcumin prevents DCs from responding to immunostimulants and inducing CD4+ T cell proliferation by blocking maturation marker, cytokine and chemokine expression and reducing both migration and endocytosis. These data suggest a therapeutic role for curcumin as an immune suppressant

  10. Depletion of intrinsic expression of Interleukin-8 in prostate cancer cells causes cell cycle arrest, spontaneous apoptosis and increases the efficacy of chemotherapeutic drugs

    Directory of Open Access Journals (Sweden)

    Lokeshwar Bal L

    2009-07-01

    Full Text Available Abstract Background The progression of all cancers is characterized by increased-cell proliferation and decreased-apoptosis. The androgen-independent prostate cancer (AIPC is the terminal stage of the disease. Many chemokines and cytokines are suspects to cause this increased tumor cell survival that ultimately leads to resistance to therapy and demise of the host. The AIPC cells, but not androgen-responsive cells, constitutively express abundant amount of the pro-inflammatory chemokine, Interleukin-8 (IL-8. The mechanism of IL-8 mediated survival and therapeutic resistance in AIPC cells is unclear at present. The purpose of this report is to show the pervasive role of IL-8 in malignant progression of androgen-independent prostate cancer (AIPC and to provide a potential new therapeutic avenue, using RNA interference. Results The functional consequence of IL-8 depletion in AIPC cells was investigated by RNA interference in two IL-8 secreting AIPC cell lines, PC-3 and DU145. The non-IL-8 secreting LNCaP and LAPC-4 cells served as controls. Cells were transfected with RISC-free siRNA (control or validated-pool of IL-8 siRNA. Transfection with 50 nM IL-8 siRNA caused >95% depletion of IL-8 mRNA and >92% decrease in IL-8 protein. This reduction in IL-8 led to cell cycle arrest at G1/S boundary and decreases in cell cycle-regulated proteins: Cyclin D1 and Cyclin B1 (both decreased >50% and inhibition of ERK1/2 activity by >50%. Further, the spontaneous apoptosis was increased by >43% in IL-8 depleted cells, evidenced by increases in caspase-9 activation and cleaved-PARP. IL-8 depletion caused significant decreases in anti-apoptotic proteins, BCL-2, BCL-xL due to decrease in both mRNA and post-translational stability, and increased levels of pro-apoptotic BAX and BAD proteins. More significantly, depletion of intracellular IL-8 increased the cytotoxic activity of multiple chemotherapeutic drugs. Specifically, the cytotoxicity of Docetaxel

  11. Immune Cells and Molecular Networks in Experimentally Induced Pulpitis.

    Science.gov (United States)

    Renard, E; Gaudin, A; Bienvenu, G; Amiaud, J; Farges, J C; Cuturi, M C; Moreau, A; Alliot-Licht, B

    2016-02-01

    Dental pulp is a dynamic tissue able to resist external irritation during tooth decay by using immunocompetent cells involved in innate and adaptive responses. To better understand the immune response of pulp toward gram-negative bacteria, we analyzed biological mediators and immunocompetent cells in rat incisor pulp experimentally inflamed by either lipopolysaccharide (LPS) or saline solution (phosphate-buffered saline [PBS]). Untreated teeth were used as control. Expression of pro- and anti-inflammatory cytokines, chemokine ligands, growth factors, and enzymes were evaluated at the transcript level, and the recruitment of the different leukocytes in pulp was measured by fluorescence-activated cell-sorting analysis after 3 h, 9 h, and 3 d post-PBS or post-LPS treatment. After 3 d, injured rat incisors showed pulp wound healing and production of reparative dentin in both LPS and PBS conditions, testifying to the reversible pulpitis status of this model. IL6, IL1-β, TNF-α, CCL2, CXCL1, CXCL2, MMP9, and iNOS gene expression were significantly upregulated after 3 h of LPS stimulation as compared with PBS. The immunoregulatory cytokine IL10 was also upregulated after 3 h, suggesting that LPS stimulates not only inflammation but also immunoregulation. Fluorescence-activated cell-sorting analysis revealed a significant, rapid, and transient increase in leukocyte levels 9 h after PBS and LPS stimulation. The quantity of dendritic cells was significantly upregulated with LPS versus PBS. Interestingly, we identified a myeloid-derived suppressor cell-enriched cell population in noninjured rodent incisor dental pulp. The percentage of this population, known to regulate immune response, was higher 9 h after inflammation triggered with PBS and LPS as compared with the control. Taken together, these data offer a better understanding of the mechanisms involved in the regulation of dental pulp immunity that may be elicited by gram-negative bacteria. PMID:26472753

  12. Downregulation of CD4+CD25+ regulatory T cells may underlie enhanced Th1 immunity caused by immunization with activated autologous T cells

    Institute of Scientific and Technical Information of China (English)

    Qi Cao; Dangsheng Li; Ningli Li; Li Wang; Fang Du; Huiming Sheng; Yan Zhang; Juanjuan Wu; Baihua Shen; Tianwei Shen; Jingwu Zhang

    2007-01-01

    Regulatory T cells (Treg) play important roles in immune system homeostasis, and may also be involved in tumor immunotolerance by suppressing Thl immune response which is involved in anti-tumor immunity. We have previously reported that immunization with attenuated activated autologous T cells leads to enhanced anti-tumor immunity and upregulated Thl responses in vivo. However, the underlying molecular mechanisms are not well understood. Here we show that Treg function was significantly downregulated in mice that received immunization of attenuated activated autologous T cells. We found that Foxp3 expression decreased in CD4+CD25+ T cells from the immunized mice. Moreover, CD4+CD25+Foxp3+ Treg obtained from immunized mice exhibited diminished immunosuppression ability compared to those from naive mice. Further analysis showed that the serum of immunized mice contains a high level of anti-CD25 antibody (about 30 ng/ml,/K0.01 vs controls). Consistent with a role of anti-CD25 response in the down-regulation of Treg, adoptive transfer of serum from immunized mice to naive mice led to a significant decrease in Treg population and function in recipient mice. The triggering of anti-CD25 response in immunized mice can be explained by the fact that CD25 was induced to a high level in the ConA activated autologous T cells used for immunization. Our results demonstrate for the first time that immunization with attenuated activated autologous T cells evokes anti-CD25 antibody production, which leads to impeded CD4+CD25+Foxp3+ Treg expansion and function in vivo. We suggest that dampened Treg function likely contributes to enhanced Thl response in immunized mice and is at least part of the mechanism underlying the boosted anti-tumor immunity.

  13. Characterization of PrP(Sc) transmission from immune cells to neuronal cells.

    Science.gov (United States)

    Tanaka, Yufuko; Sadaike, Tetsuji; Inoshima, Yasuo; Ishiguro, Naotaka

    2012-10-01

    We investigated PrP(Sc) transmission in neuronal cells, spleen cells and several immune cells using an in vitro cell-to-cell transmission system. The transmission of PrP(Sc) in the supernatant of PrP(Sc)-infected neuronal cells was also investigated. We found that PrP(Sc) transmission was more efficient in the cell-to-cell transmission system than in the supernatant-mediated system. PrP(Sc) was more efficiently transmitted from adherent spleen cells to neuronal cells than from floating spleen cells. The adherent spleen cells were composed of macrophages (80%), dendritic cells (8%) and follicular dendritic cells (3%), indicating that macrophages play an important role in PrP(Sc) transmission from immune cells to neuronal cells. Although PrP(Sc) in the immune cells used as donor cells was gradually degraded, the PrP(Sc) transmitted to neuronal cells was observed by Western blot analysis. Investigation of the mechanism of PrP(Sc) transmission between cells represents an important step towards understanding the pathogenesis of prion diseases. PMID:23246505

  14. Depletion of histone demethylase KDM2A enhanced the adipogenic and chondrogenic differentiation potentials of stem cells from apical papilla

    International Nuclear Information System (INIS)

    Mesenchymal stem cells (MSCs) are a reliable resource for tissue regeneration, but the molecular mechanism underlying directed differentiation remains unclear; this has restricted potential MSC applications. The histone demethylase, lysine (K)-specific demethylase 2A (KDM2A), is evolutionarily conserved and ubiquitously expressed members of the JmjC-domain-containing histone demethylase family. A previous study determined that KDM2A can regulate the cell proliferation and osteo/dentinogenic differentiation of MSCs. It is not known whether KDM2A is involved in the other cell lineages differentiation of MSCs. Here, we show that depletion of KDM2A by short hairpin RNAs can enhance adipogenic and chondrogenic differentiation potentials in human stem cells from apical papilla (SCAPs). We found that the stemness-related genes, SOX2, and the embryonic stem cell master transcription factor, NANOG were significantly increased after silence of KDM2A in SCAPs. Moreover, we found that knock-down of the KDM2A co-factor, BCOR also up-regulated the mRNA levels of SOX2 and NANOG. Furthermore, Chromatin immunoprecipitation assays demonstrate that silence of KDM2A increased the histone H3 Lysine 4 (H3K4) trimethylation in the SOX2 and NANOG locus and regulates its expression. In conclusion, our results suggested that depletion of KDM2A enhanced the adipogenic and chondrogenic differentiation potentials of SCAPs by up-regulated SOX2 and NANOG, BCOR also involved in this regulation as co-factor, and provided useful information to understand the molecular mechanism underlying directed differentiation in MSCs. - Highlights: • Depletion of KDM2A enhances adipogenic/chondrogenic differentiation in SCAPs. • Depletion of KDM2A enhances the differentiation of SCAPs by activate SOX2 and NANOG. • Silence of KDM2A increases histone H3 Lysine 4 trimethylation in SOX2 and NANOG. • BCOR is co-factor of KDM2A involved in the differentiation regulation

  15. Depletion of histone demethylase KDM2A enhanced the adipogenic and chondrogenic differentiation potentials of stem cells from apical papilla

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Rui [Laboratory of Molecular Signaling and Stem Cells Therapy, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing 100050 (China); Yao, Rui [Department of Pediatrics, Stomatological Hospital of Nankai University, Tianjin 300041 (China); Du, Juan [Laboratory of Molecular Signaling and Stem Cells Therapy, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing 100050 (China); Wang, Songlin [Molecular Laboratory for Gene Therapy and Tooth Regeneration, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing 100050 (China); Department of Biochemistry and Molecular Biology, Capital Medical University School of Basic Medical Sciences, Beijing 100069 (China); Fan, Zhipeng, E-mail: zpfan@ccmu.edu.cn [Laboratory of Molecular Signaling and Stem Cells Therapy, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing 100050 (China)

    2013-11-01

    Mesenchymal stem cells (MSCs) are a reliable resource for tissue regeneration, but the molecular mechanism underlying directed differentiation remains unclear; this has restricted potential MSC applications. The histone demethylase, lysine (K)-specific demethylase 2A (KDM2A), is evolutionarily conserved and ubiquitously expressed members of the JmjC-domain-containing histone demethylase family. A previous study determined that KDM2A can regulate the cell proliferation and osteo/dentinogenic differentiation of MSCs. It is not known whether KDM2A is involved in the other cell lineages differentiation of MSCs. Here, we show that depletion of KDM2A by short hairpin RNAs can enhance adipogenic and chondrogenic differentiation potentials in human stem cells from apical papilla (SCAPs). We found that the stemness-related genes, SOX2, and the embryonic stem cell master transcription factor, NANOG were significantly increased after silence of KDM2A in SCAPs. Moreover, we found that knock-down of the KDM2A co-factor, BCOR also up-regulated the mRNA levels of SOX2 and NANOG. Furthermore, Chromatin immunoprecipitation assays demonstrate that silence of KDM2A increased the histone H3 Lysine 4 (H3K4) trimethylation in the SOX2 and NANOG locus and regulates its expression. In conclusion, our results suggested that depletion of KDM2A enhanced the adipogenic and chondrogenic differentiation potentials of SCAPs by up-regulated SOX2 and NANOG, BCOR also involved in this regulation as co-factor, and provided useful information to understand the molecular mechanism underlying directed differentiation in MSCs. - Highlights: • Depletion of KDM2A enhances adipogenic/chondrogenic differentiation in SCAPs. • Depletion of KDM2A enhances the differentiation of SCAPs by activate SOX2 and NANOG. • Silence of KDM2A increases histone H3 Lysine 4 trimethylation in SOX2 and NANOG. • BCOR is co-factor of KDM2A involved in the differentiation regulation.

  16. Glycation of extracellular matrix proteins impairs migration of immune cells.

    Science.gov (United States)

    Haucke, Elisa; Navarrete-Santos, Alexander; Simm, Andreas; Silber, Rolf-Edgar; Hofmann, Britt

    2014-01-01

    The immune response during aging and diabetes is disturbed and may be due to the altered migration of immune cells in an aged tissue. Our study should prove the hypothesis that age and diabetes-related advanced glycation end products (AGEs) have an impact on the migration and adhesion of human T-cells. To achieve our purpose, we used in vitro AGE-modified proteins (soluble albumin and fibronectin [FN]), as well as human collagen obtained from bypass graft. A Boyden chamber was used to study cell migration. Migrated Jurkat T-cells were analyzed by flow cytometry and cell adhesion by crystal violet staining. Actin polymerization was determined by phalloidin-Alexa-fluor 488-labeled antibody and fluorescence microscopy. We found that significantly fewer cells (50%, p = 0.003) migrated through methylglyoxal modified FN. The attachment to FN in the presence of AGE-bovine serum albumin (BSA) was also reduced (p < 0.05). In ex vivo experiments, isolated collagen from human vein graft material negatively affected the migration of the cells depending on the grade of AGE modification of the collagen. Collagen with a low AGE level reduced the cell migration by 30%, and collagen with a high AGE level by 60%. Interaction of the cells with an AGE-modified matrix, but not with soluble AGEs like BSA-AGE per se, was responsible for a disturbed migration. The reduced migration was accompanied by an impaired actin polymerization. We conclude that AGEs-modified matrix protein inhibits cell migration and adhesion of Jurkat T-cells.

  17. Wolbachia surface protein induces innate immune responses in mosquito cells

    Directory of Open Access Journals (Sweden)

    Pinto Sofia B

    2012-01-01

    Full Text Available Abstract Background Wolbachia endosymbiotic bacteria are capable of inducing chronic upregulation of insect immune genes in some situations and this phenotype may influence the transmission of important insect-borne pathogens. However the molecules involved in these interactions have not been characterized. Results Here we show that recombinant Wolbachia Surface Protein (WSP stimulates increased transcription of immune genes in mosquito cells derived from the mosquito Anopheles gambiae, which is naturally uninfected with Wolbachia; at least two of the upregulated genes, TEP1 and APL1, are known to be important in Plasmodium killing in this species. When cells from Aedes albopictus, which is naturally Wolbachia-infected, were challenged with WSP lower levels of upregulation were observed than for the An. gambiae cells. Conclusions We have found that WSP is a strong immune elicitor in a naturally Wolbachia-uninfected mosquito species (Anopheles gambiae while a milder elicitor in a naturally-infected species (Aedes albopictus. Since the WSP of a mosquito non-native (nematode Wolbachia strain was used, these data suggest that there is a generalized tolerance to WSP in Ae. albopictus.

  18. Detecting Secreted Analytes from Immune Cells: An Overview of Technologies.

    Science.gov (United States)

    Pike, Kelly A; Hui, Caitlyn; Krawczyk, Connie M

    2016-01-01

    The tumor microenvironment is largely shaped by secreted factors and infiltrating immune cells and the nature of this environment can profoundly influence tumor growth and progression. As such, there is an increasing need to identify and quantify secreted factors by tumor cells, tumor-associated cells, and infiltrating immune cells. To meet this need, the dynamic range of immunoassays such as ELISAs and ELISpots have been improved and the scope of reagents commercially available has been expanded. In addition, new bead-based and membrane-based screening arrays have been developed to allow for the simultaneous detection of multiple analytes in one sample. Similarly, the optimization of intracellular staining for flow cytometry now allows for the quantitation of multiple cytokines from either a purified cell population or a complex mixed cell suspension. Herein, we review the rapidly evolving technologies that are currently available to detect secreted analytes. Emphasis is placed on discussing the advantages and disadvantages of these assays and their applications. PMID:27581018

  19. Induction of acquired resistance to anti estrogen by reversible mitochondrial DNA depletion in breast cancer cell line

    Science.gov (United States)

    Naito, Akihiro; Carcel-Trullols, Jaime; Xie, Cheng-hui; Evans, Teresa T; Mizumachi, Takatsugu; Higuchi, Masahiro

    2008-01-01

    Although the net benefits of tamoxifen in adjuvant breast cancer therapy have been proven, the recurrence of the cancer in an aggressive and hormone independent form has been highly problematic. We previously demonstrated the important role mitochondrial DNA (mtDNA) plays in hormone-independence in prostate cancer. Here, the role of mtDNA in breast cancer progression was investigated. We established hydroxytamoxifen (4-OHT) resistant HTRMCF by growing MCF-7, a human breast adenocarcinoma cells, in the presence of 4-OHT. HTRMCF was cross-resistant to 4-OHT and ICI182,780 concurrent with the depletion of mtDNA. To further investigate the role of mtDNA depletion, MCF-7 was depleted of mtDNA by treatment with ethidium bromide. MCFρ0 was resistant to both 4-OHT and ICI182,780. Furthermore, cybrid (MCFcyb) prepared by fusion MCFρ0 with platelet to transfer mtDNA showed susceptibility to anti-estrogen. Surprisingly, after withdrawal of 4-OHT for 8 weeks, HTRMCF and their clones became susceptible to both drugs concurrent with a recovery of mtDNA. Herein, our results substantiated the first evidence that the depletion of mtDNA induced by hormone therapy triggers a shift to acquired resistance to hormone therapy in breast cancer. In addition, we showed that mtDNA depletion can be reversed, rendering the cancer cells susceptible to anti-estrogen. The hormone independent phenotype can be reversed should be a step toward more effective treatments for estrogen-responsive breast cancer. PMID:17990320

  20. Immunity booster

    International Nuclear Information System (INIS)

    The immunity booster is, according to its patent description, microbiologically pure water with an D/(D+H) isotopic concentration of 100 ppm, with physical-chemical characteristics similar to those of distilled water. It is obtained by sterilization of a mixture of deuterium depleted water, with a 25 ppm isotopic concentration, with distilled water in a volume ratio of 4:6. Unlike natural immunity boosters (bacterial agents as Bacillus Chalmette-Guerin, Corynebacterium parvum; lipopolysaccharides; human immunoglobulin) or synthetical products (levamysol; isoprinosyne with immunostimulating action), which cause hypersensitivity and shocks, thrill, fever, sickness and the immunity complex disease, the water of 100 ppm D/(D + H) isotopic concentration is a toxicity free product. The testing for immune reaction of the immunity booster led to the following results: - an increase of cell action capacity in the first immunity shielding stage (macrophages), as evidenced by stimulation of a number of essential characterizing parameters, as well as of the phagocytosis capacity, bactericide capacity, and opsonic capacity of serum; - an increase of the number of leucocyte particularly of the granulocyte in peripheral blood, produced especially when medullar toxic agents like caryolysine are used; - it hinders the effect of lowering the number of erythrocytes in peripheral blood produced by experimentally induced chronic inflammation; - an increase of nonspecific immunity defence capacity against specific bacterial aggression of both Gram-positive bacteria (Streptococcus pneumoniae558) and of the Gram-negative ones (Klebsiella pneumoniae 507); - an increase of immunity - stimulating activity (proinflamatory), like that of levamisole as evidenced by the test of stimulation of experimentally induced inflammation by means of carrageenan. The following advantages of the immunity booster are stressed: - it is toxicity free and side effect free; - can be orally administrated as food

  1. Severe Depletion of Mucosal CD4+ T Cells in AIDS-Free Simian Immunodeficiency Virus-Infected Sooty Mangabeys1

    OpenAIRE

    Gordon, Shari N.; Klatt, Nichole R.; Bosinger, Steven E; Brenchley, Jason M.; Milush, Jeffrey M.; Engram, Jessica C.; Dunham, Richard M.; Paiardini, Mirko; Klucking, Sara; Danesh, Ali; Strobert, Elizabeth A.; Apetrei, Cristian; Pandrea, Ivona V.; Kelvin, David; Douek, Daniel C.

    2007-01-01

    HIV-infected humans and SIV-infected rhesus macaques experience a rapid and dramatic loss of mucosal CD4+ T cells that is considered to be a key determinant of AIDS pathogenesis. In this study, we show that nonpathogenic SIV infection of sooty mangabeys (SMs), a natural host species for SIV, is also associated with an early, severe, and persistent depletion of memory CD4+ T cells from the intestinal and respiratory mucosa. Importantly, the kinetics of the loss of mucosal CD4+ T cells in SMs i...

  2. Emerging roles for platelets as immune and inflammatory cells.

    Science.gov (United States)

    Morrell, Craig N; Aggrey, Angela A; Chapman, Lesley M; Modjeski, Kristina L

    2014-05-01

    Despite their small size and anucleate status, platelets have diverse roles in vascular biology. Not only are platelets the cellular mediator of thrombosis, but platelets are also immune cells that initiate and accelerate many vascular inflammatory conditions. Platelets are linked to the pathogenesis of inflammatory diseases such as atherosclerosis, malaria infection, transplant rejection, and rheumatoid arthritis. In some contexts, platelet immune functions are protective, whereas in others platelets contribute to adverse inflammatory outcomes. In this review, we will discuss platelet and platelet-derived mediator interactions with the innate and acquired arms of the immune system and platelet-vessel wall interactions that drive inflammatory disease. There have been many recent publications indicating both important protective and adverse roles for platelets in infectious disease. Because of this new accumulating data, and the fact that infectious disease continues to be a leading cause of death globally, we will also focus on new and emerging concepts related to platelet immune and inflammatory functions in the context of infectious disease.

  3. Clonal evolution following chemotherapy-induced stem cell depletion in cats heterozygous for glucose-6-phosphate dehydrogenase

    International Nuclear Information System (INIS)

    The number of hematopoietic stem cells necessary to support normal hematopoiesis is not known but may be small. If so, the depletion or damage of such cells could result in apparent clonal dominance. To test this hypothesis, dimethylbusulfan [2 to 4 mg/kg intravenously (IV) x 3] was given to cats heterozygous for the X-linked enzyme glucose-6-phosphate dehydrogenase (G-6-PD). These cats were the daughters of domestic X Geoffroy parents. After the initial drug-induced cytopenias (2 to 4 weeks), peripheral blood counts and the numbers of marrow progenitors detected in culture remained normal, although the percentages of erythroid burst-forming cells (BFU-E) and granulocyte/macrophage colony-forming cells (CFU-GM) in DNA synthesis increased, as determined by the tritiated thymidine suicide technique. In three of six cats treated, a dominance of Geoffroy-type G-6-PD emerged among the progenitor cells, granulocytes, and RBCs. These skewed ratios of domestic to Geoffroy-type G-6-PD have persisted greater than 3 years. No changes in cell cycle kinetics or G-6-PD phenotypes were noted in similar studies in six control cats. These data suggest that clonal evolution may reflect the depletion or damage of normal stem cells and not only the preferential growth and dominance of neoplastic cells

  4. Ozone-Induced Nasal Type 2 Immunity in Mice Is Dependent on Innate Lymphoid Cells.

    Science.gov (United States)

    Kumagai, Kazuyoshi; Lewandowski, Ryan; Jackson-Humbles, Daven N; Li, Ning; Van Dyken, Steven J; Wagner, James G; Harkema, Jack R

    2016-06-01

    Epidemiological studies suggest that elevated ambient concentrations of ozone are associated with activation of eosinophils in the nasal airways of atopic and nonatopic children. Mice repeatedly exposed to ozone develop eosinophilic rhinitis and type 2 immune responses. In this study, we determined the role of innate lymphoid cells (ILCs) in the pathogenesis of ozone-induced eosinophilic rhinitis by using lymphoid-sufficient C57BL/6 mice, Rag2(-/-) mice that are devoid of T cells and B cells, and Rag2(-/-)Il2rg(-/-) mice that are depleted of all lymphoid cells including ILCs. The animals were exposed to 0 or 0.8 ppm ozone for 9 consecutive weekdays (4 h/d). Mice were killed 24 hours after exposure, and nasal tissues were selected for histopathology and gene expression analysis. ILC-sufficient C57BL/6 and Rag2(-/-) mice exposed to ozone developed marked eosinophilic rhinitis and epithelial remodeling (e.g., epithelial hyperplasia and mucous cell metaplasia). Chitinase-like proteins and alarmins (IL-33, IL-25, and thymic stromal lymphopoietin) were also increased morphometrically in the nasal epithelium of ozone-exposed C57BL/6 and Rag2(-/-) mice. Ozone exposure elicited increased expression of Il4, Il5, Il13, St2, eotaxin, MCP-2, Gob5, Arg1, Fizz1, and Ym2 mRNA in C57BL/6 and Rag2(-/-) mice. In contrast, ozone-exposed ILC-deficient Rag2(-/-)Il2rg(-/-) mice had no nasal lesions or overexpression of Th2- or ILC2-related transcripts. These results indicate that ozone-induced eosinophilic rhinitis, nasal epithelial remodeling, and type 2 immune activation are dependent on ILCs. To the best of our knowledge, this is the first study to demonstrate that ILCs play an important role in the nasal pathology induced by repeated ozone exposure. PMID:26559808

  5. Regulatory T cells and IL-10 independently counterregulate cytotoxic T lymphocyte responses induced by transcutaneous immunization.

    Directory of Open Access Journals (Sweden)

    Pamela Stein

    Full Text Available BACKGROUND: The imidazoquinoline derivate imiquimod induces inflammatory responses and protection against transplanted tumors when applied to the skin in combination with a cognate peptide epitope (transcutaneous immunization, TCI. Here we investigated the role of regulatory T cells (T(reg and the suppressive cytokine IL-10 in restricting TCI-induced cytotoxic T lymphocyte (CTL responses. METHODOLOGY/PRINCIPAL FINDINGS: TCI was performed with an ointment containing the TLR7 agonist imiquimod and a CTL epitope was applied to the depilated back skin of C57BL/6 mice. Using specific antibodies and FoxP3-diphteria toxin receptor transgenic (DEREG mice, we interrogated inhibiting factors after TCI: by depleting FoxP3(+ regulatory T cells we found that specific CTL-responses were greatly enhanced. Beyond this, in IL-10 deficient (IL-10(-/- mice or after blocking of IL-10 signalling with an IL-10 receptor specific antibody, the TCI induced CTL response is greatly enhanced indicating an important role for this cytokine in TCI. However, by transfer of T(reg in IL-10(-/- mice and the use of B cell deficient JHT(-/- mice, we can exclude T(reg and B cells as source of IL-10 in the setting of TCI. CONCLUSION/SIGNIFICANCE: We identify T(reg and IL-10 as two important and independently acting suppressors of CTL-responses induced by transcutaneous immunization. Advanced vaccination strategies inhibiting T(reg function and IL-10 release may lead the development of effective vaccination protocols aiming at the induction of T cell responses suitable for the prophylaxis or treatment of persistent infections or tumors.

  6. Ozone-Induced Nasal Type 2 Immunity in Mice Is Dependent on Innate Lymphoid Cells.

    Science.gov (United States)

    Kumagai, Kazuyoshi; Lewandowski, Ryan; Jackson-Humbles, Daven N; Li, Ning; Van Dyken, Steven J; Wagner, James G; Harkema, Jack R

    2016-06-01

    Epidemiological studies suggest that elevated ambient concentrations of ozone are associated with activation of eosinophils in the nasal airways of atopic and nonatopic children. Mice repeatedly exposed to ozone develop eosinophilic rhinitis and type 2 immune responses. In this study, we determined the role of innate lymphoid cells (ILCs) in the pathogenesis of ozone-induced eosinophilic rhinitis by using lymphoid-sufficient C57BL/6 mice, Rag2(-/-) mice that are devoid of T cells and B cells, and Rag2(-/-)Il2rg(-/-) mice that are depleted of all lymphoid cells including ILCs. The animals were exposed to 0 or 0.8 ppm ozone for 9 consecutive weekdays (4 h/d). Mice were killed 24 hours after exposure, and nasal tissues were selected for histopathology and gene expression analysis. ILC-sufficient C57BL/6 and Rag2(-/-) mice exposed to ozone developed marked eosinophilic rhinitis and epithelial remodeling (e.g., epithelial hyperplasia and mucous cell metaplasia). Chitinase-like proteins and alarmins (IL-33, IL-25, and thymic stromal lymphopoietin) were also increased morphometrically in the nasal epithelium of ozone-exposed C57BL/6 and Rag2(-/-) mice. Ozone exposure elicited increased expression of Il4, Il5, Il13, St2, eotaxin, MCP-2, Gob5, Arg1, Fizz1, and Ym2 mRNA in C57BL/6 and Rag2(-/-) mice. In contrast, ozone-exposed ILC-deficient Rag2(-/-)Il2rg(-/-) mice had no nasal lesions or overexpression of Th2- or ILC2-related transcripts. These results indicate that ozone-induced eosinophilic rhinitis, nasal epithelial remodeling, and type 2 immune activation are dependent on ILCs. To the best of our knowledge, this is the first study to demonstrate that ILCs play an important role in the nasal pathology induced by repeated ozone exposure.

  7. M-Cells Contribute to the Entry of an Oral Vaccine but Are Not Essential for the Subsequent Induction of Protective Immunity against Francisella tularensis

    Science.gov (United States)

    Cunningham, Aimee L.; Guentzel, M. Neal; Yu, Jieh-Juen; Hung, Chiung-Yu; Forsthuber, Thomas G.; Navara, Christopher S.; Yagita, Hideo; Williams, Ifor R.; Klose, Karl E.; Eaves-Pyles, Tonyia D.; Arulanandam, Bernard P.

    2016-01-01

    M-cells (microfold cells) are thought to be a primary conduit of intestinal antigen trafficking. Using an established neutralizing anti-RANKL (Receptor Activator of NF-κB Ligand) antibody treatment to transiently deplete M-cells in vivo, we sought to determine whether intestinal M-cells were required for the effective induction of protective immunity following oral vaccination with ΔiglB (a defined live attenuated Francisella novicida mutant). M-cell depleted, ΔiglB-vaccinated mice exhibited increased (but not significant) morbidity and mortality following a subsequent homotypic or heterotypic pulmonary F. tularensis challenge. No significant differences in splenic IFN-γ, IL-2, or IL-17 or serum antibody (IgG1, IgG2a, IgA) production were observed compared to non-depleted, ΔiglB-vaccinated animals suggesting complementary mechanisms for ΔiglB entry. Thus, we examined other possible routes of gastrointestinal antigen sampling following oral vaccination and found that ΔiglB co-localized to villus goblet cells and enterocytes. These results provide insight into the role of M-cells and complementary pathways in intestinal antigen trafficking that may be involved in the generation of optimal immunity following oral vaccination. PMID:27100824

  8. The Current Immune Function of Hepatic Dendritic Cells

    Institute of Scientific and Technical Information of China (English)

    Willy Hsu; Shang-An Shu; Eric Gershwin; Zhe-Xiong Lian

    2007-01-01

    While only a small percentage of the liver as dendritic cells, they play a major role in the regulation of liver immunity. Four major types of dendritic cell subsets include myeloid CD8α-B220-, lymphoid CD8α+B220-,plasmacytoid CD8α-B220+, and natural killer dendritic cell with CD8α-B220-NK1.1+ phenotype. Although these subsets have slightly different characteristics, they are all poor na(i)ve T cell stimulators. In exchange for their reduced capacity for allostimulation, hepatic DCs are equipped with an enhanced ability to secrete cytokines in response to TLR stimulation. In addition, they have increased level of phagocytosis. Both of these traits suggest hepatic DC as part of the innate immune system. With such a high rate of exposure to the dietary and commensal antigens, it is important for the hepatic DCs to have an enhanced innate response while maintaining a tolerogenic state to avoid chronic inflammation. Only upon secondary infectivity does the hepatic DC activate memory T cells for rapid eradication of recurring pathogen. On the other hand, overly tolerogenic characteristics of hepatic DC may be responsible for the increase prevalence of autoimmunity or liver malignancies.

  9. Pre-transplant donor-specific T-cell alloreactivity is strongly associated with early acute cellular rejection in kidney transplant recipients not receiving T-cell depleting induction therapy.

    Directory of Open Access Journals (Sweden)

    Elena Crespo

    Full Text Available Preformed T-cell immune-sensitization should most likely impact allograft outcome during the initial period after kidney transplantation, since donor-specific memory T-cells may rapidly recognize alloantigens and activate the effector immune response, which leads to allograft rejection. However, the precise time-frame in which acute rejection is fundamentally triggered by preformed donor-specific memory T cells rather than by de novo activated naïve T cells is still to be established. Here, preformed donor-specific alloreactive T-cell responses were evaluated using the IFN-γ ELISPOT assay in a large consecutive cohort of kidney transplant patients (n = 90, to assess the main clinical variables associated with cellular sensitization and its predominant time-frame impact on allograft outcome, and was further validated in an independent new set of kidney transplant recipients (n = 67. We found that most highly T-cell sensitized patients were elderly patients with particularly poor HLA class-I matching, without any clinically recognizable sensitizing events. While one-year incidence of all types of biopsy-proven acute rejection did not differ between T-cell alloreactive and non-alloreactive patients, Receiver Operating Characteristic curve analysis indicated the first two months after transplantation as the highest risk time period for acute cellular rejection associated with baseline T-cell sensitization. This effect was particularly evident in young and highly alloreactive individuals that did not receive T-cell depletion immunosuppression. Multivariate analysis confirmed preformed T-cell sensitization as an independent predictor of early acute cellular rejection. In summary, monitoring anti-donor T-cell sensitization before transplantation may help to identify patients at increased risk of acute cellular rejection, particularly in the early phases after kidney transplantation, and thus guide decision-making regarding the use of induction

  10. Antitumor Immunity Produced by the Liver Kupffer Cells, NK Cells, NKT Cells, and CD8+ CD122+ T Cells

    Directory of Open Access Journals (Sweden)

    Shuhji Seki

    2011-01-01

    Full Text Available Mouse and human livers contain innate immune leukocytes, NK cells, NKT cells, and macrophage-lineage Kupffer cells. Various bacterial components, including Toll-like receptor (TLR ligands and an NKT cell ligand (α-galactocylceramide, activate liver Kupffer cells, which produce IL-1, IL-6, IL-12, and TNF. IL-12 activates hepatic NK cells and NKT cells to produce IFN-γ, which further activates hepatic T cells, in turn activating phagocytosis and cytokine production by Kupffer cells in a positive feedback loop. These immunological events are essentially evoked to protect the host from bacterial and viral infections; however, these events also contribute to antitumor and antimetastatic immunity in the liver by activated liver NK cells and NKT cells. Bystander CD8+CD122+ T cells, and tumor-specific memory CD8+T cells, are also induced in the liver by α-galactocylceramide. Furthermore, adoptive transfer experiments have revealed that activated liver lymphocytes may migrate to other organs to inhibit tumor growth, such as the lungs and kidneys. The immunological mechanism underlying the development of hepatocellular carcinoma in cirrhotic livers in hepatitis C patients and liver innate immunity as a double-edged sword (hepatocyte injury/regeneration, septic shock, autoimmune disease, etc. are also discussed.

  11. Hidden talents of natural killers: NK cells in innate and adaptive immunity

    OpenAIRE

    Cooper, Megan A.; Colonna, Marco; Yokoyama, Wayne M.

    2009-01-01

    Natural killer (NK) cells are innate immune lymphocytes capable of killing target cells and producing immunoregulatory cytokines. Herein, we discuss recent studies that indicate that NK cells span the conventional boundaries between innate and adaptive immunity. For example, it was recently discovered that NK cells have the capacity for memory-like responses, a property that was previously thought to be limited to adaptive immunity. NK cells have also been identified in multiple tissues, and ...

  12. Cell mediated immune response in human antirabies revaccination

    Directory of Open Access Journals (Sweden)

    Débora Regina Veiga

    1987-04-01

    Full Text Available The occurrence of secondary cell mediated immune response (CMI in human antirabies immunization was studied. The Puenzalida & Palácios vaccine was used because it is routinely used in Brazil. CMI was evaluated by lymphoblastic transformation indices obtained in whole blood culture in the presence of rabies and control (nervous tissue antigens. Eleven volunteers submitted to revaccination constituted the group under study, while three other volunteers submitted primo vaccination were utilized as control group. A clear secondary CMI to rabies antigen was detected in all the revaccinated volunteers who showed earlier and more intense response than the control group. Response to the control antigen, however, present in all the components of the first group was not detectable in two out of the three primovaccinated and very low in the third one.

  13. Autonomous immunity in mucosal epithelial cells: fortifying the barrier against infection.

    Science.gov (United States)

    Ross, Karen F; Herzberg, Mark C

    2016-06-01

    Mucosal epithelial cells express an autonomous innate immune response that controls the overgrowth of invaded bacteria, mitigates the harmful effects of the bacteria carried within, and does not rely on other external arms of the immune response. Epithelial cell autonomous innate immunity "respects" the social biology of invading bacteria to achieve symbiosis, and is the primary protective mechanism against pathogens. PMID:27005450

  14. Levels of immune cells in transcendental meditation practitioners

    Science.gov (United States)

    Infante, Jose R; Peran, Fernando; Rayo, Juan I; Serrano, Justo; Domínguez, Maria L; Garcia, Lucia; Duran, Carmen; Roldan, Ana

    2014-01-01

    Context: Relationships between mind and body have gradually become accepted. Yogic practices cause modulation of the immune system. Transcendental meditation (TM) is a specific form of mantra meditation. We reported previously different plasma levels of catecholamines and pituitary hormones in TM practitioners comparing with a control group, and patterns of the daytime secretion of these hormones different from those normally described. Aims: The aim of the following study is to evaluate the immune system in these meditation practitioners, by determining leukocytes and lymphocytes subsets. Methods: TM group consisted of 19 subjects who regularly practice either TM or the more advanced Sidhi-TM technique. A control group consisted of 16 healthy subjects who had not previously used any relaxation technique. Total leukocytes, granulocytes, lymphocytes and monocytes were counted by an automated quantitative hematology analyzer, whereas lymphocytes subsets were determined by flow cytometry. Samples were taken from each subject at 0900 h after an overnight fast. Results: The results indicated that the TM group had higher values than the control group in CD3+CD4−CD8+ lymphocytes (P < 0.05), B lymphocytes (P < 0.01) and natural killer cells (P < 0.01), whereas CD3+CD4+CD8− lymphocytes showed low levels in meditation practitioners (P < 0.001). No significant differences were observed in total leukocytes, granulocytes, monocytes, total lymphocytes or CD3+ lymphocytes comparing both groups. Conclusions: The technique of meditation studied seems to have a significant effect on immune cells, manifesting in the different circulating levels of lymphocyte subsets analyzed. The significant effect of TM on the neuroendocrine axis and its relationship with the immune system may partly explain our results. PMID:25035626

  15. Th17 cells promote cytotoxic T cell activation in tumor immunity

    OpenAIRE

    Martin-Orozco, Natalia; Muranski, Pawel; Chung, Yeonseok; Yang, Xuexian O.; Yamazaki, Tomohide; Lu, Sijie; Hwu, Patrick; Restifo, Nicholas P; Overwijk, Willem W.; Dong, Chen

    2009-01-01

    Although T helper 17 (Th17) cells have been found in human tumor tissues, their function in cancer immunity is unclear. Here we show that IL-17-deficient mice were more susceptible to the development of lung melanoma. Conversely, adoptive T cell therapy with tumor-specific Th17 cells prevented tumor development. Importantly, the donor Th17 cells retained their cytokine expression phenotype and exhibited stronger therapeutic efficacy than Th1 cells. Unexpectedly, therapy using Th17 but not Th1...

  16. Regulation of apolipoprotein A-I gene expression in Hep G2 cells depleted of Cu by cupruretic tetramine.

    Science.gov (United States)

    Wu, J Y; Zhang, J J; Wang, Y; Reaves, S K; Wang, Y R; Lei, P P; Lei, K Y

    1997-10-01

    Studies were designed to examine the regulation of apolipoprotein (apo) A-I gene expression in Cu-depleted Hep G2 cells. The cupruretic chelator N,N'-bis(2-aminoethyl)-1,3-propanediamine 4 HCl (2,3,2-tetramine or TETA) was used to maintain a 77% reduction in cellular Cu in Hep G2 cells. After two passages of TETA treatment, the relative abundance of apoA-I mRNA was elevated 52%. In TETA-treated cells, the rate of apoA-I mRNA decay measured by an actinomycin D chase study was accelerated 108%, and the synthesis of apoA-I mRNA determined by a nuclear runoff assay was enhanced 2.5-fold in TETA-treated cells. All of those changes could be reverted toward the control values with Cu supplementation for only 2 days. In transient transfection assays, a 26.7% increase in chloramphenicol O-acetyltransferase (CAT) activity for the reporter construct -256AI-CAT was observed in the treated cells. However, the ability of apoA-I regulatory protein 1 (ARP-1) to repress the CAT activity was not affected by the depressed Cu status. In addition, gel retardation experiments demonstrated that Cu depletion enhanced the binding of hepatocyte nuclear factor 4 (HNF-4) and other undefined nuclear factors to oligonucleotides containing site A, one of three regulatory sites of the apoA-I gene promoter. Moreover, the relative abundance of HNF-4 mRNA was increased 58% in the Cu-depleted cells. Thus the observed increase in apoA-I gene transcription may be mediated mostly by an elevated level of the regulatory factor, HNF-4. In summary, the present findings established the mechanism by which a depressed cellular Cu status can enhance apoA-I mRNA production and subsequently increase apoA-I synthesis. PMID:9357782

  17. Phenotypic characterisation of immune cell infiltrates in testicular germ cell neoplasia

    DEFF Research Database (Denmark)

    Hvarness, Tine; Nielsen, John E; Almstrup, Kristian;

    2013-01-01

    and overt seminoma, in comparison to biopsies from infertile men without neoplasia. The composition of immune cells was similar across all the groups studied. Macrophages, CD8(+) and CD45R0(+) T lymphocytes constituted the majority of infiltrates, B lymphocytes were present in an intermediate proportion...... and very few CD4(+) and FoxP3(+) T cells were detected. HLA-I antigen was more abundant in Sertoli cells in tubules containing CIS than in those with normal spermatogenesis. This study showed a phenotypically comparable composition of infiltrating immune cells independently of the presence of neoplasia...

  18. Immunization with adenovirus LIGHT-engineered dendritic cells induces potent T cell responses and therapeutic immunity in HBV transgenic mice.

    Science.gov (United States)

    Jiang, Wenzheng; Chen, Ran; Kong, Xiaobo; Long, Fengying; Shi, Yaru

    2014-07-31

    LIGHT, a TNF superfamily member (TNFSF14), is a type II transmembrane protein expressed on activated T cells and immature dendritic cells (DCs). However, the expression of LIGHT on mature DCs is down-regulated. Recent studies demonstrated that LIGHT provides potent costimulatory activity for T cells, enhancing proliferation and the production of Th1 cytokines independently of the B7-CD28 pathway. Here, we evaluated the effectiveness of peptide-pulsed DC-mediated antiviral immunity in HBV transgenic mice and the immunoadjuvant effect of LIGHT. The bone marrow-derived DCs were modified in vitro with an adenovirus (Ad) vector expressing mouse LIGHT (Ad-LIGHT), the expression of costimulatory molecules was up-regulated and the secretion of cytokines IL-12 and IFN-γ increased. LIGHT-modified DCs enhanced allostimulation for T cells in mixed lymphocyte reaction (MLR). HBV peptide-pulsed DCs elicited HBV specific CD8+ T cell response and reduced the level of HBsAg and HBV DNA in sera of HBV transgenic mice. Importantly, LIGHT-modified DCs could induce stronger antiviral immunity. These results support the concept that genetic modification of DCs with a recombinant LIGHT adenovirus vector may be a useful strategy for antiviral immunotherapy. PMID:24951859

  19. “Natural Regulators”: NK Cells as Modulators of T Cell Immunity

    Science.gov (United States)

    Schuster, Iona S.; Coudert, Jerome D.; Andoniou, Christopher E.; Degli-Esposti, Mariapia A.

    2016-01-01

    Natural killer (NK) cells are known as frontline responders capable of rapidly mediating a response upon encountering transformed or infected cells. Recent findings indicate that NK cells, in addition to acting as innate effectors, can also regulate adaptive immune responses. Here, we review recent studies on the immunoregulatory function of NK cells with a specific focus on their ability to affect the generation of early, as well as long-term antiviral T cell responses, and their role in modulating immune pathology and disease. In addition, we summarize the current knowledge of the factors governing regulatory NK cell responses and discuss origin, tissue specificity, and open questions about the classification of regulatory NK cells as classical NK cells versus group 1 innate lymphoid cells. PMID:27379097

  20. The Consequence of Immune Suppressive Cells in the Use of Therapeutic Cancer Vaccines and Their Importance in Immune Monitoring

    Directory of Open Access Journals (Sweden)

    Matteo Vergati

    2011-01-01

    Full Text Available Evaluating the number, phenotypic characteristics, and function of immunosuppressive cells in the tumor microenvironment and peripheral blood could elucidate the antitumor immune response and provide information to evaluate the efficacy of cancer vaccines. Further studies are needed to evaluate the correlation between changes in immunosuppressive cells and clinical outcomes of patients in cancer vaccine clinical trials. This paper focuses on the role of T-regulatory cells, myeloid-derived suppressor cells, and tumor-associated macrophages in cancer and cancer immunotherapy and their role in immune monitoring.

  1. CFTR depletion results in changes in fatty acid composition and promotes lipogenesis in intestinal Caco 2/15 cells.

    Directory of Open Access Journals (Sweden)

    Geneviève Mailhot

    Full Text Available BACKGROUND: Abnormal fatty acid composition (FA in plasma and tissue lipids frequently occurs in homozygous and even in heterozygous carriers of cystic fibrosis transmembrane conductance regulator (CFTR mutations. The mechanism(s underlying these abnormalities remained, however, poorly understood despite the potentially CFTR contributing role. METHODOLOGY/PRINCIPAL FINDINGS: The aim of the present study was to investigate the impact of CFTR depletion on FA uptake, composition and metabolism using the intestinal Caco-2/15 cell line. shRNA-mediated cftr gene silencing induced qualitative and quantitative modifications in FA composition in differentiated enterocytes as determined by gas-liquid chromatography. With the cftr gene disruption, there was a 1,5 fold increase in the total FA amount, largely attributable to monounsaturated and saturated FA compared to controls. The activity of delta-7 desaturase, estimated by the 16:1(n-7/16:0, was significantly higher in knockdown cells and consistent with the striking elevation of the n-7 FA family. When incubated with [14C]-oleic acid, CFTR-depleted cells were capable of quick incorporation and export to the medium concomitantly with the high protein expression of L-FABP known to promote intracellular FA trafficking. Accordingly, lipoprotein vehicles (CM, VLDL, LDL and HDL, isolated from CFTR knockdown cells, exhibited higher levels of radiolabeled FA. Moreover, in the presence of [14C]-acetate, knockdown cells exhibited enhanced secretion of newly synthesized phospholipids, triglycerides, cholesteryl esters and free FA, thereby suggesting a stimulation of the lipogenic pathway. Conformably, gene expression of SREBP-1c, a key lipogenic transcription factor, was increased while protein expression of the phosphorylated and inactive form of acetylCoA carboxylase was reduced, confirming lipogenesis induction. Finally, CFTR-depleted cells exhibited lower gene expression of transcription factors (PPARalpha

  2. Restoration of prostaglandin releasing macrophage populations in lethally irradiated mice with spleen cells from bone marrow-depleted donors

    Energy Technology Data Exchange (ETDEWEB)

    Shibata, Y.; Volkman, A. (East Carolina Univ. School of Medicine, Greenville, NC (USA))

    1991-04-01

    Previous studies in mice severely depleted of bone marrow cells by 89Sr showed persistent monocytopenia and impaired expression of prostaglandin E2-releasing splenic macrophages (PGSM) despite the occurrence in the spleen of more than 10-fold increases in pluripotential stem cells and M phi colony-forming cells. To determine whether the observed deficits were due to a lack of precursors of blood monocytes and PGSM in the spleens of 89Sr-treated mice, radiation chimeras were established by i.v. infusion of 2 x 10(6) spleen cells from 89Sr donor CBA/J or semisyngeneic B6CB F1 hybrid mice into lethally gamma-irradiated CBA/J recipients. Blood monocyte levels were greater than normal by day 14 and PGSM induced by Corynebacterium parvum were demonstrated by day 28. These restored M phi populations expressed the donor haplotype detected in vitro with haplotype-specific monoclonal anti-H-2K plus complement. 89Sr treatment of the chimeras resulted in profound depletion of monocytes and PGSM. The data indicate that the spleen of the 89Sr-treated mouse, which is an ineffective source of circulating monocytes and PGSM, contains cells which can generate both of these populations following infusion into lethally irradiated recipients. Since the bone marrow of such recipients was capable of being repopulated, the aggregate observations suggest that functional bone marrow is obligatory for the generation of blood monocytes and PGSM populations.

  3. Immune Thrombocytopenia in a Child with T Cell Lymphoblastic Lymphoma

    Directory of Open Access Journals (Sweden)

    Kayo Tokeji

    2016-01-01

    Full Text Available We describe the case of a 13-year-old boy who presented with persistent thrombocytopenia during maintenance chemotherapy with mercaptopurine and methotrexate for T cell lymphoblastic lymphoma. He was diagnosed with immune thrombocytopenia (ITP after thorough investigations for the relapse of lymphoma and was successfully treated with immunoglobulin and steroids. ITP is known to be associated with chronic lymphocytic leukemia, Hodgkin lymphoma, and various types of non-Hodgkin lymphoma but rarely with T cell non-Hodgkin lymphoma or in children. Diagnosis of ITP with lymphoma is challenging due to the many factors affecting platelet counts, and ITP often complicates the diagnosis or treatment course of lymphoma. The underlying mechanism of ITP with NHL is still unclear. Drug-induced immunomodulation with a reduction of regulatory T cells might have contributed to the development of ITP in our case.

  4. The interplay of sequence conservation and T cell immune recognition

    DEFF Research Database (Denmark)

    Bresciani, Anne Gøther; Sette, Alessandro; Greenbaum, Jason;

    2014-01-01

    examined the hypothesis that conservation of a peptide in bacteria that are part of the healthy human microbiome leads to a reduced level of immunogenicity due to tolerization of T cells to the commensal bacteria. This was done by comparing experimentally characterized T cell epitope recognition data from...... the Immune Epitope Database with their conservation in the human microbiome. Indeed, we did see a lower immunogenicity for conserved peptides conserved. While many aspects how this conservation comparison is done require further optimization, this is a first step towards a better understanding T cell...... recognition of peptides in bacterial pathogens is influenced by their conservation in commensal bacteria. If the further work proves that this approach is successful, the degree of overlap of a peptide with the human proteome or microbiome could be added to the arsenal of tools available to assess peptide...

  5. The role of the cell wall in plant immunity

    DEFF Research Database (Denmark)

    Malinovsky, Frederikke Gro; Fangel, Jonatan Ulrik; Willats, William George Tycho

    2014-01-01

    The battle between plants and microbes is evolutionarily ancient, highly complex, and often co-dependent. A primary challenge for microbes is to breach the physical barrier of host cell walls whilst avoiding detection by the plant's immune receptors. While some receptors sense conserved microbial...... features, others monitor physical changes caused by an infection attempt. Detection of microbes leads to activation of appropriate defense responses that then challenge the attack. Plant cell walls are formidable and dynamic barriers. They are constructed primarily of complex carbohydrates joined...... by numerous distinct connection types, and are subject to extensive post-synthetic modification to suit prevailing local requirements. Multiple changes can be triggered in cell walls in response to microbial attack. Some of these are well described, but many remain obscure. The study of the myriad of subtle...

  6. NK and NKT Cell Depletion Alters the Outcome of Experimental Pneumococcal Pneumonia: Relationship with Regulation of Interferon-γ Production

    Directory of Open Access Journals (Sweden)

    Eirini Christaki

    2015-01-01

    Full Text Available Background. Natural killer (NK and natural killer T (NKT cells contribute to the innate host defense but their role in bacterial sepsis remains controversial. Methods. C57BL/6 mice were infected intratracheally with 5 × 105 cfu of Streptococcus pneumoniae. Animals were divided into sham group (Sham; pretreated with isotype control antibody (CON group; pretreated with anti-asialo GM1 antibody (NKd group; and pretreated with anti-CD1d monoclonal antibody (NKTd group before bacterial challenge. Serum and tissue samples were analyzed for bacterial load, cytokine levels, splenocyte apoptosis rates, and cell characteristics by flow cytometry. Splenocyte miRNA expression was also analyzed and survival was assessed. Results. NK cell depletion prolonged survival. Upon inhibition of NKT cell activation, spleen NK (CD3−/NK1.1+ cells increased compared to all other groups. Inhibition of NKT cell activation led to higher bacterial loads and increased levels of serum and splenocyte IFN-γ. Splenocyte miRNA analysis showed that miR-200c and miR-29a were downregulated, while miR-125a-5p was upregulated, in anti-CD1d treated animals. These changes were moderate after NK cell depletion. Conclusions. NK cells appear to contribute to mortality in pneumococcal pneumonia. Inhibition of NKT cell activation resulted in an increase in spleen NK (CD3−/NK1.1+ cells and a higher IFN-γ production, while altering splenocyte miRNA expression.

  7. Avian Influenza Viruses, Inflammation, and CD8+ T Cell Immunity

    Science.gov (United States)

    Wang, Zhongfang; Loh, Liyen; Kedzierski, Lukasz; Kedzierska, Katherine

    2016-01-01

    Avian influenza viruses (AIVs) circulate naturally in wild aquatic birds, infect domestic poultry, and are capable of causing sporadic bird-to-human transmissions. AIVs capable of infecting humans include a highly pathogenic AIV H5N1, first detected in humans in 1997, and a low pathogenic AIV H7N9, reported in humans in 2013. Both H5N1 and H7N9 cause severe influenza disease in humans, manifested by acute respiratory distress syndrome, multi-organ failure, and high mortality rates of 60% and 35%, respectively. Ongoing circulation of H5N1 and H7N9 viruses in wild birds and poultry, and their ability to infect humans emphasizes their epidemic and pandemic potential and poses a public health threat. It is, thus, imperative to understand the host immune responses to the AIVs so we can control severe influenza disease caused by H5N1 or H7N9 and rationally design new immunotherapies and vaccines. This review summarizes our current knowledge on AIV epidemiology, disease symptoms, inflammatory processes underlying the AIV infection in humans, and recent studies on universal pre-existing CD8+ T cell immunity to AIVs. Immune responses driving the host recovery from AIV infection in patients hospitalized with severe influenza disease are also discussed. PMID:26973644

  8. Regulatory T Cells in Post-stroke Immune Homeostasis.

    Science.gov (United States)

    Liesz, Arthur; Kleinschnitz, Christoph

    2016-08-01

    The secondary neuroinflammatory response has come into focus of experimental stroke research. Immunological mechanisms after acute stroke are being investigated in the hope to identify novel and druggable pathways that contribute to secondary infarct growth after stroke. Among a variety of neuroimmunological events after acute brain ischemia, including microglial activation, brain leukocyte invasion, and secretion of pro-inflammatory factors, lymphocytes have been identified as the key leukocyte subpopulation driving the neuroinflammatory response and contributing to stroke outcome. Several studies have shown that pro-inflammatory lymphocyte subpopulations worsen stroke outcome and that inhibiting their invasion to the injured brain is neuroprotective. In contrast to the effector functions of pro-inflammatory lymphocytes, regulatory T cells (Treg) are critically involved in maintaining immune homeostasis and have been characterized as disease-limiting protective cells in several inflammatory conditions, particularly in primary inflammatory diseases of the central nervous system (CNS). However, due to the complex function of regulatory cells in immune homeostasis and disease, divergent findings have been described for the role of Treg in stroke models. Emerging evidence suggests that this discrepancy arises from potentially differing functions of Treg depending on the predominant site of action within the neurovascular unit and the surrounding inflammatory milieu. This article will provide a comprehensive review of current findings on Treg in brain ischemia models and discuss potential reasons for the observed discrepancies. PMID:27030356

  9. Tim-3: An activation marker and activation limiter of innate immune cells

    Directory of Open Access Journals (Sweden)

    Gencheng eHan

    2013-12-01

    Full Text Available Tim-3 was initially identified on activated Th1, Th17, and Tc1 cells and induces T cell death or exhaustion after binding to its ligand, Gal-9. The observed relationship between dysregulated Tim-3 expression on T cells and the progression of many clinical diseases has identified this molecule as an important target for intervention in adaptive immunity. Recent data have shown that it also plays critical roles in regulating the activities of macrophages, monocytes, dendritic cells, mast cells, natural killer cells, and endothelial cells. Although the underlying mechanisms remain unclear, dysregulation of Tim-3 expression on these innate immune cells leads to an excessive or inhibited inflammatory response and subsequent autoimmune damage or viral or tumor evasion. In this review, we focus on the expression and function of Tim-3 on innate immune cells and discuss 1 how Tim-3 is expressed and regulated on different innate immune cells; 2 how it affects the activity of different innate immune cells; and 3 how dysregulated Tim-3 expression on innate immune cells affects adaptive immunity and disease progression. Tim-3 is involved in the optimal activation of innate immune cells through its varied expression. A better understanding of the physiopathological role of the Tim-3 pathway in innate immunity will shed new light on the pathogenesis of clinical diseases, such as autoimmune diseases, chronic viral infections, and cancer, and suggest new approaches to intervention.

  10. Depletion of regulatory T cells in a hapten-induced inflammation model results in prolonged and increased inflammation driven by T cells

    DEFF Research Database (Denmark)

    Christensen, A. D.; Skov, Søren; Kvist, P. H.;

    2015-01-01

    Regulatory T cells (Tregs ) are known to play an immunosuppressive role in the response of contact hypersensitivity (CHS), but neither the dynamics of Tregs during the CHS response nor the exaggerated inflammatory response after depletion of Tregs has been characterized in detail. In this study we...

  11. Ordered Nanopillar Structured Electrodes for Depleted Bulk Heterojunction Colloidal Quantum Dot Solar Cells

    KAUST Repository

    Kramer, Illan J.

    2012-03-30

    A bulk heterojunction of ordered titania nanopillars and PbS colloidal quantum dots is developed. By using a pre-patterned template, an ordered titania nanopillar matrix with nearest neighbours 275 nm apart and height of 300 nm is fabricated and subsequently filled in with PbS colloidal quantum dots to form an ordered depleted bulk heterojunction exhibiting power conversion efficiency of 5.6%. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Prenatal cadmium exposure alters postnatal immune cell development and function

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, Miranda L.; Holásková, Ida; Elliott, Meenal; Brundage, Kathleen M.; Schafer, Rosana; Barnett, John B., E-mail: jbarnett@hsc.wvu.edu

    2012-06-01

    Cadmium (Cd) is generally found in low concentrations in the environment due to its widespread and continual use, however, its concentration in some foods and cigarette smoke is high. Although evidence demonstrates that adult exposure to Cd causes changes in the immune system, there are limited reports of immunomodulatory effects of prenatal exposure to Cd. This study was designed to investigate the effects of prenatal exposure to Cd on the immune system of the offspring. Pregnant C57Bl/6 mice were exposed to an environmentally relevant dose of CdCl{sub 2} (10 ppm) and the effects on the immune system of the offspring were assessed at two time points following birth (2 and 7 weeks of age). Thymocyte and splenocyte phenotypes were analyzed by flow cytometry. Prenatal Cd exposure did not affect thymocyte populations at 2 and 7 weeks of age. In the spleen, the only significant effect on phenotype was a decrease in the number of macrophages in male offspring at both time points. Analysis of cytokine production by stimulated splenocytes demonstrated that prenatal Cd exposure decreased IL-2 and IL-4 production by cells from female offspring at 2 weeks of age. At 7 weeks of age, splenocyte IL-2 production was decreased in Cd-exposed males while IFN-γ production was decreased from both male and female Cd-exposed offspring. The ability of the Cd-exposed offspring to respond to immunization with a S. pneumoniae vaccine expressing T-dependent and T-independent streptococcal antigens showed marked increases in the levels of both T-dependent and T-independent serum antibody levels compared to control animals. CD4{sup +}FoxP3{sup +}CD25{sup +} (nTreg) cell percentages were increased in the spleen and thymus in all Cd-exposed offspring except in the female spleen where a decrease was seen. CD8{sup +}CD223{sup +} T cells were markedly decreased in the spleens in all offspring at 7 weeks of age. These findings suggest that even very low levels of Cd exposure during gestation can

  13. How stem cells speak with host immune cells in inflammatory brain diseases.

    Science.gov (United States)

    Pluchino, Stefano; Cossetti, Chiara

    2013-09-01

    Advances in stem cell biology have raised great expectations that diseases and injuries of the central nervous system (CNS) may be ameliorated by the development of non-hematopoietic stem cell medicines. Yet, the application of adult stem cells as CNS therapeutics is challenging and the interpretation of some of the outcomes ambiguous. In fact, the initial idea that stem cell transplants work only via structural cell replacement has been challenged by the observation of consistent cellular signaling between the graft and the host. Cellular signaling is the foundation of coordinated actions and flexible responses, and arises via networks of exchanging and interacting molecules that transmit patterns of information between cells. Sustained stem cell graft-to-host communication leads to remarkable trophic effects on endogenous brain cells and beneficial modulatory actions on innate and adaptive immune responses in vivo, ultimately promoting the healing of the injured CNS. Among a number of adult stem cell types, mesenchymal stem cells (MSCs) and neural stem/precursor cells (NPCs) are being extensively investigated for their ability to signal to the immune system upon transplantation in experimental CNS diseases. Here, we focus on the main cellular signaling pathways that grafted MSCs and NPCs use to establish a therapeutically relevant cross talk with host immune cells, while examining the role of inflammation in regulating some of the bidirectionality of these communications. We propose that the identification of the players involved in stem cell signaling might contribute to the development of innovative, high clinical impact therapeutics for inflammatory CNS diseases.

  14. Thymic function recovery after unrelated donor cord blood or T-cell depleted HLA-haploidentical stem cell transplantation correlates with leukemia relapse

    OpenAIRE

    Clave, Emmanuel; Lisini, Daniela; Douay, Corinne; Giorgiani, Giovanna; Busson, Marc; Zecca, Marco; Moretta, Francesca; Acquafredda, Gloria; Brescia, Letizia P.; Locatelli, Franco; Toubert, Antoine

    2013-01-01

    Use of alternative donors/sources of hematopoietic stem cells (HSC), such as cord blood (CB) or HLA-haploidentical (Haplo)-related donors, is associated with a significant delay in immune reconstitution after transplantation. Long-term T-cell immune reconstitution largely relies on the generation of new T cells in the recipient thymus, which can be evaluated through signal joint (sj) and beta T-cell-Receptor Excision Circles (TREC) quantification. We studied two groups of 33 and 24 children r...

  15. The role of regulatory T cells in the control of B cell mediated immune responses

    OpenAIRE

    Wollenberg, Ivonne

    2011-01-01

    Tese de doutoramento, Ciências Biomédicas (Imunologia), Universidade de Lisboa, Faculdade de Medicina, 2011 This thesis reports research on the regulation of immune responses leading to a humoral immune reaction. This type of immune phenomena is based on B-T cell interactions. The first part of the thesis is devoted to study the effect of OX40-ligand blockade in preventing allergic airways disease in mice. Allergic airways disease is a Th2-dependent pathology associated with production of ...

  16. Targeted impairment of thymidine kinase 2 expression in cells induces mitochondrial DNA depletion and reveals molecular mechanisms of compensation of mitochondrial respiratory activity

    International Nuclear Information System (INIS)

    Highlights: → We impaired TK2 expression in Ost TK1- cells via siRNA-mediated interference (TK2-). → TK2 impairment caused severe mitochondrial DNA (mtDNA) depletion in quiescent cells. → Despite mtDNA depletion, TK2- cells show high cytochrome oxidase activity. → Depletion of mtDNA occurs without imbalance in the mitochondrial dNTP pool. → Nuclear-encoded ENT1, DNA-pol γ, TFAM and TP gene expression is lowered in TK2- cells. -- Abstract: The mitochondrial DNA (mtDNA) depletion syndrome comprises a clinically heterogeneous group of diseases characterized by reductions of the mtDNA abundance, without associated point mutations or rearrangements. We have developed the first in vitro model to study of mtDNA depletion due to reduced mitochondrial thymidine kinase 2 gene (TK2) expression in order to understand the molecular mechanisms involved in mtDNA depletion syndrome due to TK2 mutations. Small interfering RNA targeting TK2 mRNA was used to decrease TK2 expression in Ost TK1- cells, a cell line devoid of endogenous thymidine kinase 1 (TK1). Stable TK2-deficient cell lines showed a reduction of TK2 levels close to 80%. In quiescent conditions, TK2-deficient cells showed severe mtDNA depletion, also close to 80% the control levels. However, TK2-deficient clones showed increased cytochrome c oxidase activity, higher cytochrome c oxidase subunit I transcript levels and higher subunit II protein expression respect to control cells. No alterations of the deoxynucleotide pools were found, whereas a reduction in the expression of genes involved in nucleoside/nucleotide homeostasis (human equilibrative nucleoside transporter 1, thymidine phosphorylase) and mtDNA maintenance (DNA-polymerase γ, mitochondrial transcription factor A) was observed. Our findings highlight the importance of cellular compensatory mechanisms that enhance the expression of respiratory components to ensure respiratory activity despite profound depletion in mtDNA levels.

  17. Type 3 innate lymphoid cell depletion is mediated by TLRs in lymphoid tissues of simian immunodeficiency virus-infected macaques.

    Science.gov (United States)

    Xu, Huanbin; Wang, Xiaolei; Lackner, Andrew A; Veazey, Ronald S

    2015-12-01

    Innate lymphoid cells (ILCs) type 3, also known as lymphoid tissue inducer cells, plays a major role in both the development and remodeling of organized lymphoid tissues and the maintenance of adaptive immune responses. HIV/simian immunodeficiency virus (SIV) infection causes breakdown of intestinal barriers resulting in microbial translocation, leading to systemic immune activation and disease progression. However, the effects of HIV/SIV infection on ILC3 are unknown. Here, we analyzed ILC3 from mucosal and systemic lymphoid tissues in chronically SIV-infected macaques and uninfected controls. ILC3 cells were defined and identified in macaque lymphoid tissues as non-T, non-B (lineage-negative), c-Kit(+)IL-7Rα(+) (CD117(+)CD127(+)) cells. These ILC3 cells highly expressed CD90 (∼ 63%) and aryl hydrocarbon receptor and produced IL-17 (∼ 63%), IL-22 (∼ 36%), and TNF-α (∼ 72%) but did not coexpress CD4 or NK cell markers. The intestinal ILC3 cell loss correlated with the reduction of total CD4(+) T cells and T helper (Th)17 and Th22 cells in the gut during SIV infection (P lymphoid tissues in SIV-infected macaques, further contributing to the HIV-induced impairment of gut-associated lymphoid tissue structure and function, especially in mucosal tissues.

  18. [Significance of regulatory B cells in nosogenesis of immune thrombocytopenia].

    Science.gov (United States)

    Li, Xin; Wang, Fang; Ding, Kai Yang; Dai, Lan

    2014-04-01

    This study was aimed to investigate the role of regulatory B cells (Breg) in pathogenesis of immune thrombocytopenia (ITP) and its clinical significance. A total of 35 ITP patients and 20 normal controls were enrolled in this study. The expression of CD19(+)CD24(hi)CD38(hi) B cells was detected by flow cytometry and the expression of IL-10 mRNA and TGF-β1 mRNA was assayed by RT-PCR. The results indicated that the expression level of CD19(+)CD24(hi)CD38(hi) B cells in peripheral blood of newly diagnosed ITP patients was obviously lower than that in normal controls (P < 0.05); the expression level of CD19(+)CD24(hi)CD38(hi) B cells in ITP patients with increased platelet count after treatment was higher than that before treatment (P < 0.05); the expression level of IL-10 mRNA in newly diagnosed ITP patients was significantly lower than that the in normal controls (P < 0.05), the expression level of TGF-β1 mRNA in newly diagnosed ITP patients increases as compared with normal controls (P < 0.05), after treatment with DXM the expression of IL-10 mRNA was enhanced, the expression of TGF-β1 mRNA was reduced as compared with expression level before treatment (P < 0.05). It is concluded that the Breg cells may play an important role in the pathogenesis of ITP via humoral immunity and its regulation of T lymphocytes.

  19. The immune-body cytokine network defines a social architecture of cell interactions

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    Alon Uri

    2006-10-01

    Full Text Available Abstract Background Three networks of intercellular communication can be associated with cytokine secretion; one limited to cells of the immune system (immune cells, one limited to parenchymal cells of organs and tissues (body cells, and one involving interactions between immune and body cells (immune-body interface. These cytokine connections determine the inflammatory response to injury and subsequent healing as well as the biologic consequences of the adaptive immune response to antigens. We informatically probed the cytokine database to uncover the underlying network architecture of the three networks. Results We now report that the three cytokine networks are among the densest of complex networks yet studied, and each features a characteristic profile of specific three-cell motifs. Some legitimate cytokine connections are shunned (anti-motifs. Certain immune cells can be paired by their input-output positions in a cytokine architecture tree of five tiers: macrophages (MΦ and B cells (BC comprise the first tier; the second tier is formed by T helper 1 (Th1 and T helper 2 (Th2 cells; the third tier includes dendritic cells (DC, mast cells (MAST, Natural Killer T cells (NK-T and others; the fourth tier is formed by neutrophils (NEUT and Natural Killer cells (NK; and the Cytotoxic T cell (CTL stand alone as a fifth tier. The three-cell cytokine motif architecture of immune system cells places the immune system in a super-family that includes social networks and the World Wide Web. Body cells are less clearly stratified, although cells involved in wound healing and angiogenesis are most highly interconnected with immune cells. Conclusion Cytokine network architecture creates an innate cell-communication platform that organizes the biologic outcome of antigen recognition and inflammation. Informatics sheds new light on immune-body systems organization. Reviewers This article was reviewed by Neil Greenspan, Matthias von Herrath and Anne Cooke.

  20. 滤除白细胞异体血对围术期患儿细胞免疫功能的影响%Effects of leukocyte-depleted allogeneic blood transfusion on perioperative cellular immunity in children

    Institute of Scientific and Technical Information of China (English)

    邢准; 王秋实; 刁艳妮

    2014-01-01

    Objective To evaluate the effects of leukocyte-depleted allogeneic blood transfusion on perioperative cellular immunity in children.Methods Three hundred and fifty-nine ASA Ⅰ or Ⅱ children (aged 3 months-14 years and weighing 5-74 kg) requiring allogeneic blood transfusion during operation were randomly divided into two groups:163 children receiving normal allogeneic blood transfusion (control group,group C) and 196 children receiving leukocyte-depleted allogeneic blood transfusion (group D).Blood samples were collected from the peripheral vein before blood transfusion,and 2 and 6 days after blood transfusion for determination of the levels of CD3+,CD4+,CD8 +,and CD56+ by flow cytometry.CD4+ /CD8+ ratio was calculated.The volume of allogeneic blood transfusion during operation,the duration of operation,postoperative drainage,antibiotic administration,hospital stay and the incidence of postoperative infection were recorded.Rssults The levels of CD3+,CD4+,CD56+ and CD4+/CD8+ ratio significantly increased at 6 days after blood transfusion while the duration of postoperative drainage,postoperative antibiotic administration,hospital stay and the incidence of postoperative infection significantly decreased in group D compared with group C.Conclusion Leukocyte-depleted allogeneic blood transfusion is helpful in improving the postoperative cellular immunity in children.

  1. Regulatory T cells control immune responses through their nonredundant tissue specific features

    OpenAIRE

    Sari eLehtimäki; Riitta eLahesmaa

    2013-01-01

    Regulatory T cells (Treg) are needed to control immune responses and to maintain immune homeostasis. Most potent regulators are Foxp3 expressing CD4+ T cells which can be roughly divided in to two main groups, natural Treg cells (nTreg) developing in the thymus and induced or adaptive Treg cells (iTreg) developing in the periphery from naïve, conventional T cells. Both nTreg cells and iTreg cells have their own, nonredundant roles in the immune system, with nTreg cells mainly maintaining...

  2. Genomic Correlates of Immune-Cell Infiltrates in Colorectal Carcinoma

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    Marios Giannakis

    2016-04-01

    Full Text Available Large-scale genomic characterization of tumors from prospective cohort studies may yield new insights into cancer pathogenesis. We performed whole-exome sequencing of 619 incident colorectal cancers (CRCs and integrated the results with tumor immunity, pathology, and survival data. We identified recurrently mutated genes in CRC, such as BCL9L, RBM10, CTCF, and KLF5, that were not previously appreciated in this disease. Furthermore, we investigated the genomic correlates of immune-cell infiltration and found that higher neoantigen load was positively associated with overall lymphocytic infiltration, tumor-infiltrating lymphocytes (TILs, memory T cells, and CRC-specific survival. The association with TILs was evident even within microsatellite-stable tumors. We also found positive selection of mutations in HLA genes and other components of the antigen-processing machinery in TIL-rich tumors. These results may inform immunotherapeutic approaches in CRC. More generally, this study demonstrates a framework for future integrative molecular epidemiology research in colorectal and other malignancies.

  3. Disruption of Early Tumor Necrosis Factor Alpha Signaling Prevents Classical Activation of Dendritic Cells in Lung-Associated Lymph Nodes and Development of Protective Immunity against Cryptococcal Infection

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    Jintao Xu

    2016-07-01

    Full Text Available Anti-tumor necrosis factor alpha (anti-TNF-α therapies have been increasingly used to treat inflammatory diseases and are associated with increased risk of invasive fungal infections, including Cryptococcus neoformans infection. Using a mouse model of cryptococcal infection, we investigated the mechanism by which disruption of early TNF-α signaling results in the development of nonprotective immunity against C. neoformans. We found that transient depletion of TNF-α inhibited pulmonary fungal clearance and enhanced extrapulmonary dissemination of C. neoformans during the adaptive phase of the immune response. Higher fungal burdens in TNF-α-depleted mice were accompanied by markedly impaired Th1 and Th17 responses in the infected lungs. Furthermore, early TNF-α depletion also resulted in disrupted transcriptional initiation of the Th17 polarization program and subsequent upregulation of Th1 genes in CD4+ T cells in the lung-associated lymph nodes (LALN of C. neoformans-infected mice. These defects in LALN T cell responses were preceded by a dramatic shift from a classical toward an alternative activation of dendritic cells (DC in the LALN of TNF-α-depleted mice. Taken together, our results indicate that early TNF-α signaling is required for optimal DC activation, and the initial Th17 response followed by Th1 transcriptional prepolarization of T cells in the LALN, which further drives the development of protective immunity against cryptococcal infection in the lungs. Thus, administration of anti-TNF-α may introduce a particularly greater risk for newly acquired fungal infections that require generation of protective Th1/Th17 responses for their containment and clearance.

  4. Disruption of Early Tumor Necrosis Factor Alpha Signaling Prevents Classical Activation of Dendritic Cells in Lung-Associated Lymph Nodes and Development of Protective Immunity against Cryptococcal Infection

    Science.gov (United States)

    Xu, Jintao; Eastman, Alison J.; Flaczyk, Adam; Neal, Lori M.; Zhao, Guolei; Carolan, Jacob; Malachowski, Antoni N.; Stolberg, Valerie R.; Yosri, Mohammed; Chensue, Stephen W.; Curtis, Jeffrey L.; Osterholzer, John J.

    2016-01-01

    ABSTRACT Anti-tumor necrosis factor alpha (anti-TNF-α) therapies have been increasingly used to treat inflammatory diseases and are associated with increased risk of invasive fungal infections, including Cryptococcus neoformans infection. Using a mouse model of cryptococcal infection, we investigated the mechanism by which disruption of early TNF-α signaling results in the development of nonprotective immunity against C. neoformans. We found that transient depletion of TNF-α inhibited pulmonary fungal clearance and enhanced extrapulmonary dissemination of C. neoformans during the adaptive phase of the immune response. Higher fungal burdens in TNF-α-depleted mice were accompanied by markedly impaired Th1 and Th17 responses in the infected lungs. Furthermore, early TNF-α depletion also resulted in disrupted transcriptional initiation of the Th17 polarization program and subsequent upregulation of Th1 genes in CD4+ T cells in the lung-associated lymph nodes (LALN) of C. neoformans-infected mice. These defects in LALN T cell responses were preceded by a dramatic shift from a classical toward an alternative activation of dendritic cells (DC) in the LALN of TNF-α-depleted mice. Taken together, our results indicate that early TNF-α signaling is required for optimal DC activation, and the initial Th17 response followed by Th1 transcriptional prepolarization of T cells in the LALN, which further drives the development of protective immunity against cryptococcal infection in the lungs. Thus, administration of anti-TNF-α may introduce a particularly greater risk for newly acquired fungal infections that require generation of protective Th1/Th17 responses for their containment and clearance. PMID:27406560

  5. T cell immunity and vaccines against invasive fungal diseases.

    Science.gov (United States)

    Ito, James Isami

    2011-01-01

    Over the past two decades much has been learned about the immunology of invasive fungal infection, especially invasive candidiasis and invasive aspergillosis. Although quite different in their pathogenesis, the major common protective host response is Th1 mediated. It is through Th1 cytokine production that the effector cells, phagocytes, are activated to kill the fungus. A more thorough understanding of the pathogenesis of disease, the elicited protective Th1 immune response, the T cell antigen(s) which elicit this response, and the mechanism(s) whereby one can enhance, reconstitute, or circumvent the immunosuppressed state will, hopefully, lead to the development of a vaccine(s) capable of protecting even the most immunocompromised of hosts.

  6. Subversion of cell-autonomous immunity and cell migration by Legionella pneumophila effectors

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    Sylvia eSimon

    2015-09-01

    Full Text Available Bacteria trigger host defense and inflammatory processes such as cytokine production, pyroptosis and the chemotactic migration of immune cells towards the source of infection. However, a number of pathogens interfere with these immune functions by producing specific so-called effector proteins, which are delivered to host cells via dedicated secretion systems. Air-borne Legionella pneumophila bacteria trigger an acute and potential fatal inflammation in the lung termed Legionnaires’ disease. The opportunistic pathogen L. pneumophila is a natural parasite of free-living amoebae, but also replicates in alveolar macrophages and accidentally infects humans. The bacteria employ the Icm/Dot type IV secretion system and as many as 300 different effector proteins to govern host cell interactions and establish in phagocytes an intracellular replication niche, the Legionella-containing vacuole. Some Icm/Dot-translocated effector proteins target cell autonomous immunity or cell migration, i.e. they interfere with (i endocytic, secretory or retrograde vesicle trafficking pathways, (ii organelle or cell motility, (iii the inflammasome and programmed cell death, or (iv the transcription factor NF-κB. Here we review recent mechanistic insights into the subversion of cellular immune functions by L. pneumophila.

  7. Subversion of Cell-Autonomous Immunity and Cell Migration by Legionella pneumophila Effectors

    Science.gov (United States)

    Simon, Sylvia; Hilbi, Hubert

    2015-01-01

    Bacteria trigger host defense and inflammatory processes, such as cytokine production, pyroptosis, and the chemotactic migration of immune cells toward the source of infection. However, a number of pathogens interfere with these immune functions by producing specific so-called “effector” proteins, which are delivered to host cells via dedicated secretion systems. Air-borne Legionella pneumophila bacteria trigger an acute and potential fatal inflammation in the lung termed Legionnaires’ disease. The opportunistic pathogen L. pneumophila is a natural parasite of free-living amoebae, but also replicates in alveolar macrophages and accidentally infects humans. The bacteria employ the intracellular multiplication/defective for organelle trafficking (Icm/Dot) type IV secretion system and as many as 300 different effector proteins to govern host–cell interactions and establish in phagocytes an intracellular replication niche, the Legionella-containing vacuole. Some Icm/Dot-translocated effector proteins target cell-autonomous immunity or cell migration, i.e., they interfere with (i) endocytic, secretory, or retrograde vesicle trafficking pathways, (ii) organelle or cell motility, (iii) the inflammasome and programed cell death, or (iv) the transcription factor NF-κB. Here, we review recent mechanistic insights into the subversion of cellular immune functions by L. pneumophila. PMID:26441958

  8. Distinct nuclear gene expression profiles in cells with mtDNA depletion and homoplasmic A3243G mutation

    Energy Technology Data Exchange (ETDEWEB)

    Jahangir Tafrechi, Roshan S. [Department of Molecular Cell Biology, Leiden University Medical Center, P.O. Box 9503, 2300 RA Leiden (Netherlands); Svensson, Peter J. [Department of Toxicogenetics, Leiden University Medical Center, P.O. Box 9503, 2300 RA Leiden (Netherlands); Department of Oncology, Radiology and Clinical Immunology, University Hospital, 75185 Uppsala (Sweden); Janssen, George M.C. [Department of Molecular Cell Biology, Leiden University Medical Center, P.O. Box 9503, 2300 RA Leiden (Netherlands); Szuhai, Karoly [Department of Molecular Cell Biology, Leiden University Medical Center, P.O. Box 9503, 2300 RA Leiden (Netherlands); Maassen, J. Antonie [Department of Molecular Cell Biology, Leiden University Medical Center, P.O. Box 9503, 2300 RA Leiden (Netherlands); Raap, Anton K. [Department of Molecular Cell Biology, Leiden University Medical Center, P.O. Box 9503, 2300 RA Leiden (Netherlands)]. E-mail: A.K.Raap@lumc.nl

    2005-10-15

    The pathobiochemical pathways determining the wide variability in phenotypic expression of mitochondrial DNA (mtDNA) mutations are not well understood. Most pathogenic mtDNA mutations induce a general defect in mitochondrial respiration and thereby ATP synthesis. Yet phenotypic expression of the different mtDNA mutations shows large variations that are difficult to reconcile with ATP depletion as sole pathogenic factor, implying that additional mechanisms contribute to the phenotype. Here, we use DNA microarrays to identify changes in nuclear gene expression resulting from the presence of the A3243G diabetogenic mutation and from a depletion of mtDNA ({rho}{sup 0} cells). We find that cells respond mildly to these mitochondrial states with both general and specific changes in nuclear gene expression. This observation indicates that cells can sense the status of mtDNA. A number of genes show divergence in expression in {rho}{sup 0} cells compared to cells with the A3243G mutation, such as genes involved in oxidative phosphorylation. As a common response in A3243G and {rho}{sup 0} cells, mRNA levels for extracellular matrix genes are up-regulated, while the mRNA levels of genes involved in ubiquitin-mediated protein degradation and in ribosomal protein synthesis is down-regulated. This reduced expression is reflected at the level of cytosolic protein synthesis in both A3243G and {rho}{sup 0} cells. Our finding that mitochondrial dysfunction caused by different mutations affects nuclear gene expression in partially distinct ways suggests that multiple pathways link mitochondrial function to nuclear gene expression and contribute to the development of the different phenotypes in mitochondrial disease.

  9. Innate lymphoid cells and natural killer T cells in the gastrointestinal tract immune system.

    Science.gov (United States)

    Montalvillo, Enrique; Garrote, José Antonio; Bernardo, David; Arranz, Eduardo

    2014-05-01

    The gastrointestinal tract is equipped with a highly specialized intrinsic immune system. However, the intestine is exposed to a high antigenic burden that requires a fast, nonspecific response -so-called innate immunity- to maintain homeostasis and protect the body from incoming pathogens. In the last decade multiple studies helped to unravel the particular developmental requirements and specific functions of the cells that play a role in innate immunity. In this review we shall focus on innate lymphoid cells, a newly discovered, heterogeneous set of cells that derive from an Id2-dependent lymphoid progenitor cell population. These cells have been categorized on the basis of the pattern of cytokines that they secrete, and the transcription factors that regulate their development and functions. Innate lymphoid cells play a role in the early response to pathogens, the anatomical contention of the commensal flora, and the maintenance of epithelial integrity.Amongst the various innate lymphoid cells we shall lay emphasis on a subpopulation with several peculiarities, namely that of natural killer T cells, a subset of T lymphocytes that express both T-cell and NK-cell receptors. The most numerous fraction of the NKT population are the so-called invariant NKT or iNKT cells. These iNKT cells have an invariant TCR and recognize the glycolipidic structures presented by the CD1d molecule, a homolog of class-I MHC molecules. Following activation they rapidly acquire cytotoxic activity and secrete both Th1 and Th2 cytokines, including IL-17. While their specific role is not yet established, iNKT cells take part in a great variety of intestinal immune responses ranging from oral tolerance to involvement in a number of gastrointestinal conditions.

  10. Innate lymphoid cells and natural killer T cells in the gastrointestinal tract immune system

    Directory of Open Access Journals (Sweden)

    Enrique Montalvillo

    2014-05-01

    Full Text Available The gastrointestinal tract is equipped with a highly specialized intrinsic immune system. However, the intestine is exposed to a high antigenic burden that requires a fast, nonspecific response -so-called innate immunity- to maintain homeostasis and protect the body from incoming pathogens. In the last decade multiple studies helped to unravel the particular developmental requirements and specific functions of the cells that play a role in innate immunity. In this review we shall focus on innate lymphoid cells, a newly discovered, heterogeneous set of cells that derive from an Id2-dependent lymphoid progenitor cell population. These cells have been categorized on the basis of the pattern of cytokines that they secrete, and the transcription factors that regulate their development and functions. Innate lymphoid cells play a role in the early response to pathogens, the anatomical contention of the commensal flora, and the maintenance of epithelial integrity. Amongst the various innate lymphoid cells we shall lay emphasis on a subpopulation with several peculiarities, namely that of natural killer T cells, a subset of T lymphocytes that express both T-cell and NK-cell receptors. The most numerous fraction of the NKT population are the so-called invariant NKT or iNKT cells. These iNKT cells have an invariant TCR and recognize the glycolipidic structures presented by the CD1d molecule, a homolog of class-I MHC molecules. Following activation they rapidly acquire cytotoxic activity and secrete both Th1 and Th2 cytokines, including IL-17. While their specific role is not yet established, iNKT cells take part in a great variety of intestinal immune responses ranging from oral tolerance to involvement in a number of gastrointestinal conditions.

  11. Lipid body accumulation alters calcium signaling dynamics in immune cells.

    Science.gov (United States)

    Greineisen, William E; Speck, Mark; Shimoda, Lori M N; Sung, Carl; Phan, Nolwenn; Maaetoft-Udsen, Kristina; Stokes, Alexander J; Turner, Helen

    2014-09-01

    There is well-established variability in the numbers of lipid bodies (LB) in macrophages, eosinophils, and neutrophils. Similarly to the steatosis observed in adipocytes and hepatocytes during hyperinsulinemia and nutrient overload, immune cell LB hyper-accumulate in response to bacterial and parasitic infection and inflammatory presentations. Recently we described that hyperinsulinemia, both in vitro and in vivo, drives steatosis and phenotypic changes in primary and transformed mast cells and basophils. LB reach high numbers in these steatotic cytosols, and here we propose that they could dramatically impact the transcytoplasmic signaling pathways. We compared calcium release and influx responses at the population and single cell level in normal and steatotic model mast cells. At the population level, all aspects of FcɛRI-dependent calcium mobilization, as well as activation of calcium-dependent downstream signaling targets such as NFATC1 phosphorylation are suppressed. At the single cell level, we demonstrate that LB are both sources and sinks of calcium following FcɛRI cross-linking. Unbiased analysis of the impact of the presence of LB on the rate of trans-cytoplasmic calcium signals suggest that LB enrichment accelerates calcium propagation, which may reflect a Bernoulli effect. LB abundance thus impacts this fundamental signaling pathway and its downstream targets.

  12. iNKT Cells Are Responsible for the Apoptotic Reduction of Basophils That Mediate Th2 Immune Responses Elicited by Papain in Mice Following γPGA Stimulation.

    Science.gov (United States)

    Park, Hyun Jung; Lee, Sung Won; Park, Se-Ho; Hong, Seokmann

    2016-01-01

    Recent studies have demonstrated that Bacillus subtilis-derived poly-gamma glutamic acid (γPGA) treatment suppresses the development of allergic diseases such as atopic dermatitis (AD). Although basophils, an innate immune cell, are known to play critical roles in allergic immune responses and repeated long-term administration of γPGA results in decreased splenic basophils in an AD murine model, the underlying mechanisms by which γPGA regulates basophil frequency remain unclear. To investigate how γPGA modulates basophils, we employed basophil-mediated Th2 induction in vivo model elicited by the allergen papain protease. Repeated injection of γPGA reduced the abundance of basophils and their production of IL4 in mice, consistent with our previous study using NC/Nga AD model mice. The depletion of basophils by a single injection of γPGA was dependent on the TLR4/DC/IL12 axis. CD1d-dependent Vα14 TCR invariant natural killer T (iNKT) cells are known to regulate a variety of immune responses, such as allergy. Because iNKT cell activation is highly sensitive to IL12 produced by DCs, we evaluated whether the effect of γPGA on basophils is mediated by iNKT cell activation. We found that in vivo γPGA treatment did not induce the reduction of basophils in iNKT cell-deficient CD1d KO mice, suggesting the critical role of iNKT cells in γPGA-mediated basophil depletion at the early time points. Furthermore, increased apoptotic basophil reduction triggered by iNKT cells upon γPGA stimulation was mainly attributed to Th1 cytokines such as IFNγ and TNFα, consequently resulting in inhibition of papain-induced Th2 differentiation via diminishing basophil-derived IL4. Taken together, our results clearly demonstrate that γPGA-induced iNKT cell polarization toward the Th1 phenotype induces apoptotic basophil depletion, leading to the suppression of Th2 immune responses. Thus, elucidation of the crosstalk between innate immune cells will contribute to the design and

  13. The Role of CD103+ Dendritic Cells in the Intestinal Mucosal Immune System

    OpenAIRE

    Ruane, Darren Thomas; Ed C Lavelle

    2011-01-01

    While dendritic cells (DC) are central to the induction and regulation of adaptive immunity, these cells are very heterogenous and specific subsets can be characterized based on the expression of cell surface markers and functional properties. Intestinal CD103+ DCs are the subject of particular interest due to their role in regulating mucosal immunity. Since the epithelial surfaces are constantly exposed to a high antigenic load, tight regulation of innate and adaptive intestinal immune respo...

  14. Amino acid containing thapsigargin analogues deplete androgen receptor protein via synthesis inhibition and induce the death of prostate cancer cells

    DEFF Research Database (Denmark)

    Griend, Donald J Vander; Antony, Lizamma; Dalrymple, Susan L;

    2009-01-01

    There are quantitative and/or qualitative mechanisms allowing androgen receptor (AR) growth signaling in androgen ablation refractory prostate cancer cells. Regardless of the mechanism, agents that deplete AR protein expression prevent such AR growth signaling. Thapsigargin (TG) is a highly cell......-penetrant sequiterpene-lactone that once inside cells inhibits (IC(50), approximately 10 nmol/L) critically important housekeeping SERCA 2b calcium pumps in the endoplasmic reticulum. Using a series of five genetically diverse androgen ablation refractory human prostate cancer lines (LNCaP, LAPC-4, VCaP, MDA-PCa-2b, and......-specific proteases, such as prostate-specific antigen and prostate-specific membrane antigen, or cancer-specific proteases, such as fibroblast activation protein, so that toxicity of these prodrugs is selectively targeted to metastatic sites of prostate cancer. Based on these results, these prodrugs are undergoing...

  15. Phenotypic and functional plasticity of cells of innate immunity: macrophages, mast cells and neutrophils

    DEFF Research Database (Denmark)

    Galli, Stephen J; Borregaard, Niels; Wynn, Thomas A

    2011-01-01

    Hematopoietic cells, including lymphoid and myeloid cells, can develop into phenotypically distinct 'subpopulations' with different functions. However, evidence indicates that some of these subpopulations can manifest substantial plasticity (that is, undergo changes in their phenotype and function......). Here we focus on the occurrence of phenotypically distinct subpopulations in three lineages of myeloid cells with important roles in innate and acquired immunity: macrophages, mast cells and neutrophils. Cytokine signals, epigenetic modifications and other microenvironmental factors can substantially...... and, in some cases, rapidly and reversibly alter the phenotype of these cells and influence their function. This suggests that regulation of the phenotype and function of differentiated hematopoietic cells by microenvironmental factors, including those generated during immune responses, represents...

  16. A phase I study of CD25/regulatory T-cell-depleted donor lymphocyte infusion for relapse after allogeneic stem cell transplantation

    Science.gov (United States)

    Nikiforow, Sarah; Kim, Haesook T.; Daley, Heather; Reynolds, Carol; Jones, Kyle Thomas; Armand, Philippe; Ho, Vincent T.; Alyea, Edwin P.; Cutler, Corey S.; Ritz, Jerome; Antin, Joseph H.; Soiffer, Robert J.; Koreth, John

    2016-01-01

    Donor lymphocyte infusions are used to treat relapse after allogeneic hematopoietic stem cell transplantation, but responses are inadequate. In addition to effector cells, infusions contain CD25+ regulatory T cells (Treg) that may suppress graft-versus-tumor responses. We undertook a phase I study of donor lymphocyte infusions depleted of CD25+ T cells in patients with hematologic malignancies who had relapsed after transplantation. Twenty-one subjects received CD25/Treg-depleted infusions following removal of CD25+ cells using antibody-conjugated magnetic beads. Sixteen subjects received prior cytoreductive therapy. Four were in complete remission at the time of infusion. Two dose levels were administered: 1×107 (n=6) and 3×107 CD3+ cells/kg (n=15). A median 2.3 log-depletion of CD4+CD25+FOXP3+ Treg was achieved. Seven subjects (33%) developed clinically significant graft-versus-host disease by 1 year, including one patient who died. At dose level 1, five subjects had progressive disease and one had stable disease. At dose level 2, nine subjects (60%) achieved or maintained responses (8 complete responses, 1 partial response), including seven with active disease at the time of infusion. A shorter period between relapse and infusion was associated with response at dose level 2 (P=0.016). The 1-year survival rate was 53% among patients treated with dose level 2. Four of eight subjects with acute myeloid leukemia remained in remission at 1 year. When compared to unmodified donor lymphocyte infusions in 14 contemporaneous patients meeting study eligibility, CD25/Treg depletion was associated with a better response rate and improved event-free survival. Circulating naïve and central memory CD4+ T cells increased after CD25/Treg-depleted infusion, but no immunophenotypic signature for response was noted. CD25/Treg-depleted donor infusion appears feasible and capable of inducing graft-versus-tumor responses without excessive graft-versus-host disease. (Clinical

  17. Cryo-ablation improves anti-tumor immunity through recovering tumor educated dendritic cells in tumor-draining lymph nodes

    Directory of Open Access Journals (Sweden)

    He XZ

    2015-03-01

    -ablation showed weak anti-tumor immunity, only inhibiting the growth of rechallenged tumors. But many IL-10-low DCs, rather than IL-10-high DCs, infiltrated the tumors. More importantly, Tregs inhibited the performance of these DCs; and depletion of Tregs greatly improved anti-tumor immunity in vivo. Conclusion: Cryo-ablation could recover function of tumor induced tolerogenic DCs in vitro; and depletion of Tregs could improve this anti-tumor effect in vivo. The Tregs/CD4+T and Tregs/CD25+T cells in TDLNs inhibit DCs’ activity and function. Keywords: glioma, cryo-ablation, dendritic cells, tumor-draining lymph nodes, anti-tumor immunity

  18. Non-neuronal Cells in ALS: Role of Glial, Immune cells and Blood-CNS Barriers.

    Science.gov (United States)

    Puentes, Fabiola; Malaspina, Andrea; van Noort, Johannes M; Amor, Sandra

    2016-03-01

    Neurological dysfunction and motor neuron degeneration in amyotrophic lateral sclerosis (ALS) is strongly associated with neuroinflammation reflected by activated microglia and astrocytes in the CNS. In ALS endogenous triggers in the CNS such as aggregated protein and misfolded proteins activate a pathogenic response by innate immune cells. However, there is also strong evidence for a neuroprotective immune response in ALS. Emerging evidence also reveals changes in the peripheral adaptive immune responses as well as alterations in the blood brain barrier that may aid traffic of lymphocytes and antibodies into the CNS. Understanding the triggers of neuroinflammation is key to controlling neuronal loss. Here, we review the current knowledge regarding the roles of non-neuronal cells as well as the innate and adaptive immune responses in ALS. Existing ALS animal models, in particular genetic rodent models, are very useful to study the underlying pathogenic mechanisms of motor neuron degeneration. We also discuss the approaches used to target the pathogenic immune responses and boost the neuroprotective immune pathways as novel immunotherapies for ALS. PMID:26780491

  19. Regulatory T Cells Control Immune Responses through Their Non-Redundant Tissue Specific Features

    OpenAIRE

    Lehtimäki, Sari; Lahesmaa, Riitta

    2013-01-01

    Regulatory T cells (Treg) are needed in the control of immune responses and to maintain immune homeostasis. Of this subtype of regulatory lymphocytes, the most potent are Foxp3 expressing CD4+ T cells, which can be roughly divided into two main groups; natural Treg cells (nTreg), developing in the thymus, and induced or adaptive Treg cells (iTreg), developing in the periphery from naïve, conventional T cells. Both nTreg cells and iTreg cells have their own, non-redundant roles in the immune s...

  20. Therapeutic immunization with HIV-1 Tat reduces immune activation and loss of regulatory T-cells and improves immune function in subjects on HAART.

    Directory of Open Access Journals (Sweden)

    Barbara Ensoli

    Full Text Available UNLABELLED: Although HAART suppresses HIV replication, it is often unable to restore immune homeostasis. Consequently, non-AIDS-defining diseases are increasingly seen in treated individuals. This is attributed to persistent virus expression in reservoirs and to cell activation. Of note, in CD4(+ T cells and monocyte-macrophages of virologically-suppressed individuals, there is continued expression of multi-spliced transcripts encoding HIV regulatory proteins. Among them, Tat is essential for virus gene expression and replication, either in primary infection or for virus reactivation during HAART, when Tat is expressed, released extracellularly and exerts, on both the virus and the immune system, effects that contribute to disease maintenance. Here we report results of an ad hoc exploratory interim analysis (up to 48 weeks on 87 virologically-suppressed HAART-treated individuals enrolled in a phase II randomized open-label multicentric clinical trial of therapeutic immunization with Tat (ISS T-002. Eighty-eight virologically-suppressed HAART-treated individuals, enrolled in a parallel prospective observational study at the same sites (ISS OBS T-002, served for intergroup comparison. Immunization with Tat was safe, induced durable immune responses, and modified the pattern of CD4(+ and CD8(+ cellular activation (CD38 and HLA-DR together with reduction of biochemical activation markers and persistent increases of regulatory T cells. This was accompanied by a progressive increment of CD4(+ T cells and B cells with reduction of CD8(+ T cells and NK cells, which were independent from the type of antiretroviral regimen. Increase in central and effector memory and reduction in terminally-differentiated effector memory CD4(+ and CD8(+ T cells were accompanied by increases of CD4(+ and CD8(+ T cell responses against Env and recall antigens. Of note, more immune-compromised individuals experienced greater therapeutic effects. In contrast, these changes

  1. Immunity

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    2008254 Prokaryotic expression and immunogenicity of Fba,a novel fibronectin-binding protein of group A streptococcus.MA Cuiqing(马翠柳),et al.Dept Immunol,Basic Med Coll,Hebei Med Univ,Shijiazhuang 050017.Chin J Infect Dis 2008;26(3):146-150.Objective To express the novel fibronectin-binding protein Fba ofgroupAstreptococcus(GAS)and analyze its immunogenicity,so to evaluate the immune responses to GAS infection.Methods fbagene was amplified by

  2. Survival of cancer stem cells under hypoxia and serum depletion via decrease in PP2A activity and activation of p38-MAPKAPK2-Hsp27.

    Directory of Open Access Journals (Sweden)

    Shih-Pei Lin

    Full Text Available Hypoxia and serum depletion are common features of solid tumors that occur upon antiangiogenesis, irradiation and chemotherapy across a wide variety of malignancies. Here we show that tumor cells expressing CD133, a marker for colorectal cancer initiating or stem cells, are enriched and survive under hypoxia and serum depletion conditions, whereas CD133- cells undergo apoptosis. CD133+ tumor cells increase cancer stem cell and epithelial-mesenchymal transition properties. Moreover, via screening a panel of tyrosine and serine/threonine kinase pathways, we identified Hsp27 is constitutively activated in CD133+ cells rather than CD133- cell under hypoxia and serum depletion conditions. However, there was no difference in Hsp27 activation between CD133+ and CD133- cells under normal growth condition. Hsp27 activation, which was mediated by the p38MAPK-MAPKAPK2-Hsp27 pathway, is required for CD133+ cells to inhibit caspase 9 and 3 cleavage. In addition, inhibition of Hsp27 signaling sensitizes CD133+ cells to hypoxia and serum depletion -induced apoptosis. Moreover, the antiapoptotic pathway is also activated in spheroid culture-enriched CD133+ cancer stem cells from a variety of solid tumor cells including lung, brain and oral cancer, suggesting it is a common pathway activated in cancer stem cells from multiple tumor types. Thus, activation of PP2A or inactivation of the p38MAPK-MAPKAPK2-Hsp27 pathway may develop new strategies for cancer therapy by suppression of their TIC population.

  3. MHC basis of T cell-dependent heterologous immunity to arenaviruses.

    Science.gov (United States)

    Daniels, Keith A; Hatfield, Steven D; Welsh, Raymond M; Brehm, Michael A

    2014-09-01

    Having a history of infection with one pathogen may sometimes provide a level of T cell-dependent protective heterologous immunity to another pathogen. This immunity was initially thought due to cross-reactive T cell epitopes, but recent work has suggested that such protective immunity can be initiated nonspecifically by the action of cytokines on memory T cells. We retested this concept using two small and well-defined arenaviruses, lymphocytic choriomeningitis virus (LCMV) and Pichinde virus (PV), and found that heterologous immunity in these systems was indeed linked to T cell epitopes and the major histocompatibility complex.

  4. Depletion region effect of highly efficient hole conductor free CH3NH3PbI3 perovskite solar cells.

    Science.gov (United States)

    Aharon, Sigalit; Gamliel, Shany; El Cohen, Bat; Etgar, Lioz

    2014-06-14

    The inorganic-organic perovskite is currently attracting a lot of attention due to its use as a light harvester in solar cells. The large absorption coefficients, high carrier mobility and good stability of organo-lead halide perovskites present good potential for their use as light harvesters in mesoscopic heterojunction solar cells. This work concentrated on a unique property of the lead halide perovskite, its function simultaneously as a light harvester and a hole conductor in the solar cell. A two-step deposition technique was used to optimize the perovskite deposition and to enhance the solar cell efficiency. It was revealed that the photovoltaic performance of the hole conductor free perovskite solar cell is strongly dependent on the depletion layer width which was created at the TiO2-CH3NH3PbI3 junction. X-ray diffraction measurements indicate that there were no changes in the crystallographic structure of the CH3NH3PbI3 perovskite over time, which supports the high stability of these hole conductor free perovskite solar cells. Furthermore, the power conversion efficiency of the best cells reached 10.85% with a fill factor of 68%, a Voc of 0.84 V, and a Jsc of 19 mA cm(-2), the highest efficiency to date of a hole conductor free perovskite solar cell. PMID:24736900

  5. Hormone activities and the cell cycle machinery in immunity-triggered growth inhibition.

    Science.gov (United States)

    Reitz, M U; Gifford, M L; Schäfer, P

    2015-04-01

    Biotic stress and diseases caused by pathogen attack pose threats in crop production and significantly reduce crop yields. Enhancing immunity against pathogens is therefore of outstanding importance in crop breeding. However, this must be balanced, as immune activation inhibits plant growth. This immunity-coupled growth trade-off does not support resistance but is postulated to reflect the reallocation of resources to drive immunity. There is, however, increasing evidence that growth-immunity trade-offs are based on the reconfiguration of hormone pathways, shared by growth and immunity signalling. Studies in roots revealed the role of hormones in orchestrating growth across different cell types, with some hormones showing a defined cell type-specific activity. This is apparently highly relevant for the regulation of the cell cycle machinery and might be part of the growth-immunity cross-talk. Since plants are constantly exposed to Immuno-activating microbes under agricultural conditions, the transition from a growth to an immunity operating mode can significantly reduce crop yield and can conflict our efforts to generate next-generation crops with improved yield under climate change conditions. By focusing on roots, we outline the current knowledge of hormone signalling on the cell cycle machinery to explain growth trade-offs induced by immunity. By referring to abiotic stress studies, we further introduce how root cell type-specific hormone activities might contribute to growth under immunity and discuss the feasibility of uncoupling the growth-immunity cross-talk.

  6. A systems model for immune cell interactions unravels the mechanism of inflammation in human skin.

    Directory of Open Access Journals (Sweden)

    Najl V Valeyev

    Full Text Available Inflammation is characterized by altered cytokine levels produced by cell populations in a highly interdependent manner. To elucidate the mechanism of an inflammatory reaction, we have developed a mathematical model for immune cell interactions via the specific, dose-dependent cytokine production rates of cell populations. The model describes the criteria required for normal and pathological immune system responses and suggests that alterations in the cytokine production rates can lead to various stable levels which manifest themselves in different disease phenotypes. The model predicts that pairs of interacting immune cell populations can maintain homeostatic and elevated extracellular cytokine concentration levels, enabling them to operate as an immune system switch. The concept described here is developed in the context of psoriasis, an immune-mediated disease, but it can also offer mechanistic insights into other inflammatory pathologies as it explains how interactions between immune cell populations can lead to disease phenotypes.

  7. LV305, a dendritic cell-targeting integration-deficient ZVex(TM)-based lentiviral vector encoding NY-ESO-1, induces potent anti-tumor immune response.

    Science.gov (United States)

    Albershardt, Tina Chang; Campbell, David James; Parsons, Andrea Jean; Slough, Megan Merrill; Ter Meulen, Jan; Berglund, Peter

    2016-01-01

    We have engineered an integration-deficient lentiviral vector, LV305, to deliver the tumor antigen NY-ESO-1 to human dendritic cells in vivo through pseudotyping with a modified Sindbis virus envelop protein. Mice immunized once with LV305 developed strong, dose-dependent, multifunctional, and cytotoxic NY-ESO-1-specific cluster of differentiation 8 (CD8) T cells within 14 days post-immunization and could be boosted with LV305 at least twice to recall peak-level CD8 T-cell responses. Immunization with LV305 protected mice against tumor growth in an NY-ESO-1-expressing CT26 lung metastasis model, with the protective effect abrogated upon depletion of CD8 T cells. Adoptive transfer of CD8 T cells, alone or together with CD4 T cells or natural killer cells, from LV305-immunized donor mice to tumor-bearing recipient mice conferred significant protection against metastatic tumor growth. Biodistribution of injected LV305 in mice was limited to the site of injection and the draining lymph node, and injected LV305 exhibited minimal excretion. Mice injected with LV305 developed little to no adverse effects, as evaluated by toxicology studies adherent to good laboratory practices. Taken together, these data support the development of LV305 as a clinical candidate for treatment against tumors expressing NY-ESO-1. PMID:27626061

  8. LV305, a dendritic cell-targeting integration-deficient ZVexTM-based lentiviral vector encoding NY-ESO-1, induces potent anti-tumor immune response

    Science.gov (United States)

    Albershardt, Tina Chang; Campbell, David James; Parsons, Andrea Jean; Slough, Megan Merrill; ter Meulen, Jan; Berglund, Peter

    2016-01-01

    We have engineered an integration-deficient lentiviral vector, LV305, to deliver the tumor antigen NY-ESO-1 to human dendritic cells in vivo through pseudotyping with a modified Sindbis virus envelop protein. Mice immunized once with LV305 developed strong, dose-dependent, multifunctional, and cytotoxic NY-ESO-1-specific cluster of differentiation 8 (CD8) T cells within 14 days post-immunization and could be boosted with LV305 at least twice to recall peak-level CD8 T-cell responses. Immunization with LV305 protected mice against tumor growth in an NY-ESO-1-expressing CT26 lung metastasis model, with the protective effect abrogated upon depletion of CD8 T cells. Adoptive transfer of CD8 T cells, alone or together with CD4 T cells or natural killer cells, from LV305-immunized donor mice to tumor-bearing recipient mice conferred significant protection against metastatic tumor growth. Biodistribution of injected LV305 in mice was limited to the site of injection and the draining lymph node, and injected LV305 exhibited minimal excretion. Mice injected with LV305 developed little to no adverse effects, as evaluated by toxicology studies adherent to good laboratory practices. Taken together, these data support the development of LV305 as a clinical candidate for treatment against tumors expressing NY-ESO-1. PMID:27626061

  9. LV305, a dendritic cell-targeting integration-deficient ZVex(TM)-based lentiviral vector encoding NY-ESO-1, induces potent anti-tumor immune response.

    Science.gov (United States)

    Albershardt, Tina Chang; Campbell, David James; Parsons, Andrea Jean; Slough, Megan Merrill; Ter Meulen, Jan; Berglund, Peter

    2016-01-01

    We have engineered an integration-deficient lentiviral vector, LV305, to deliver the tumor antigen NY-ESO-1 to human dendritic cells in vivo through pseudotyping with a modified Sindbis virus envelop protein. Mice immunized once with LV305 developed strong, dose-dependent, multifunctional, and cytotoxic NY-ESO-1-specific cluster of differentiation 8 (CD8) T cells within 14 days post-immunization and could be boosted with LV305 at least twice to recall peak-level CD8 T-cell responses. Immunization with LV305 protected mice against tumor growth in an NY-ESO-1-expressing CT26 lung metastasis model, with the protective effect abrogated upon depletion of CD8 T cells. Adoptive transfer of CD8 T cells, alone or together with CD4 T cells or natural killer cells, from LV305-immunized donor mice to tumor-bearing recipient mice conferred significant protection against metastatic tumor growth. Biodistribution of injected LV305 in mice was limited to the site of injection and the draining lymph node, and injected LV305 exhibited minimal excretion. Mice injected with LV305 developed little to no adverse effects, as evaluated by toxicology studies adherent to good laboratory practices. Taken together, these data support the development of LV305 as a clinical candidate for treatment against tumors expressing NY-ESO-1.

  10. A role for b-cell-depleting agents in treating psoriatic skin lesions induced by tumor necrosis factor-alpha antagonists: A case report and literature review

    Directory of Open Access Journals (Sweden)

    Ancuta Codrina Mihaela

    2014-01-01

    Full Text Available Despite recent advances in understanding the pathological pathways, clinical pattern and management opportunities for new-onset psoriasis as a paradoxical adverse event in patients receiving TNF inhibitors for their immune-mediated disorder, there is a subset of patients who are either partial responders or non-responders, whatever the therapeutic scenario. We present the case of new-onset psoriasis and severe alopecia development in a case study of long-standing rheumatoid arthritis (RA treated with adalimumab (ADA and leflunomide. Since skin lesions and alopecia are resistant to the classic protocol (topical treatment, ADA discontinuation and RA becomes highly active, rituximab (RTX was started. Dramatic improvement in joint disease, total remission of alopecia and partial remission of pustular psoriasis were described after the first RTX cycle. Although B-cell-depleting agents result in controversial effects on psoriatic skin lesions, this is the first case of ADA-induced psoriasis and alopecia that improved under RTX, suggesting a possible role in treating such a patient population.

  11. Invariant NKT cells and CD1d(+) cells amass in human omentum and are depleted in patients with cancer and obesity.

    LENUS (Irish Health Repository)

    Lynch, Lydia

    2012-02-01

    Invariant NKT (iNKT) cells recognize lipid antigens presented by CD1d and respond rapidly by killing tumor cells and release cytokines that activate and regulate adaptive immune responses. They are essential for tumor rejection in various mouse models, but clinical trials in humans involving iNKT cells have been less successful, partly due to their rarity in humans compared with mice. Here we describe an accumulation of functional iNKT cells in human omentum, a migratory organ with healing properties. Analysis of 39 omental samples revealed that T cells are the predominant lymphoid cell type and of these, 10% expressed the invariant Valpha24Jalpha18 TCR chain, found on iNKT cells, higher than in any other human organ tested to date. About 15% of omental hematopoietic cells expressed CD1d, compared with 1% in blood (p<0.001). Enriched omental iNKT cells killed CD1d(+) targets and released IFN-gamma and IL-4 upon activation. Omental iNKT-cell frequencies were lower in patients with severe obesity (p=0.005), and with colorectal carcinoma (p=0.004) compared with lean healthy subjects. These data suggest a novel role for the omentum in immune regulation and tumor immunity and identify it as a potential source of iNKT cells for therapeutic use.

  12. Depletion of T cell epitopes in lysostaphin mitigates anti-drug antibody response and enhances antibacterial efficacy in vivo

    Science.gov (United States)

    Zhao, Hongliang; Verma, Deeptak; Li, Wen; Choi, Yoonjoo; Ndong, Christian; Fiering, Steven N.; Bailey-Kellogg, Chris; Griswold, Karl E.

    2015-01-01

    SUMMARY The enzyme lysostaphin possesses potent anti-staphylococcal activity and represents a promising antibacterial drug candidate; however, its immunogenicity poses a barrier to clinical translation. Here, structure-based biomolecular design enabled widespread depletion of lysostaphin’s DRB1*0401 restricted T cell epitopes, and resulting deimmunized variants exhibited striking reductions in anti-drug antibody responses upon administration to humanized HLA-transgenic mice. This reduced immunogenicity translated into improved efficacy in the form of protection against repeated challenges with methicillin-resistant Staphylococcus aureus, or MRSA. In contrast, while wild type lysostaphin was efficacious against the initial MRSA infection, it failed to clear subsequent bacterial challenges that were coincident with escalating anti-drug antibody titers. These results extend the existing deimmunization literature, in which reduced immunogenicity and retained efficacy are assessed independently of each other. By correlating in vivo efficacy with longitudinal measures of anti-drug antibody development, we provide the first direct evidence that T cell epitope depletion manifests enhanced biotherapeutic efficacy. PMID:26000749

  13. NKT cell self-reactivity: evolutionary master key of immune homeostasis?

    DEFF Research Database (Denmark)

    Navikas, Shohreh

    2011-01-01

    through evolution by higher vertebrates could be related to their central function as master regulators of immune homeostasis that in part is shared with regulatory T cells. Hypothetical views on how self-reactive NKT cells secure such a central role will also be proposed....... for quick, non-specific immune responses to pathogens and more efficient, long-lasting ones upon specific recognition of recurrent pathogens. Specialized cells have arisen as the sentinels of these functions, including macrophages, natural killer (NK), and T and B-lymphocytes. Interestingly, a population...... of immune cells that can exert both of these complex functions, NKT cells, not only share common functions but also exhibit shared cell surface markers of cells of both arms of the immune system. These features, in combination with sophisticated maintenance of immune homeostasis, will be discussed...

  14. Depletion of drug-surviving glioma cells by a second phase treatment with low concentration of salinomycin

    Directory of Open Access Journals (Sweden)

    Zahid M. Delwar

    2011-06-01

    Full Text Available Standard treatment for glioma includes surgery, radiotherapy and chemotherapy but the outcome of patients is very poor. Antineoplastic drugs are usually administered alone or in combination for variable times (continuously or in cycles in a single phase schedule. In this study we explored in vitro the antiproliferative effect of a 2 phases treatment. In the first phase, glioma cells where treated for 3-4 weeks with hydroxyurea (HU or aphidicolin and then for 4 weeks with salinomycin, a drug that preferentially inhibits the proliferation of cancer stem cells. We found that salinomycin, is able to slowly deplete the fraction of glioma cells that survive the exposure to HU or aphidicolin. Surviving cells were killed at salinomycin concentrations lower than those required to kill untreated cells. The fraction of surviving cell showed traits of senescence including increased activity of the senescence associated -β-galactosidase (SA-β-gal marker. Our data suggest that drug-induced senescent cells may constitute a novel target for cancer treatment and can be exploited in a two phases therapeutic regimen.

  15. Delayed cell cycle progression in selenoprotein W depleted cells is regulated by a mitogen-activated protein kinase kinase 4–p38–p53 pathway

    Science.gov (United States)

    Selenoprotein W (SEPW1) is a ubiquitous, highly conserved thioredoxin-like protein whose depletion causes a p53- and p21Cip1-dependent G1-phase cell cycle arrest in breast and prostate epithelial cells. SEPW1 depletion increases phosphorylation of Ser33 in p53, which is associated with decreased p53...

  16. Activated T cells sustain myeloid-derived suppressor cell-mediated immune suppression.

    Science.gov (United States)

    Pinton, Laura; Solito, Samantha; Damuzzo, Vera; Francescato, Samuela; Pozzuoli, Assunta; Berizzi, Antonio; Mocellin, Simone; Rossi, Carlo Riccardo; Bronte, Vincenzo; Mandruzzato, Susanna

    2016-01-12

    The expansion of myeloid derived suppressor cells (MDSCs), a suppressive population able to hamper the immune response against cancer, correlates with tumor progression and overall survival in several cancer types. We have previously shown that MDSCs can be induced in vitro from precursors present in the bone marrow and observed that these cells are able to actively proliferate in the presence of activated T cells, whose activation level is critical to drive the suppressive activity of MDSCs. Here we investigated at molecular level the mechanisms involved in the interplay between MDSCs and activated T cells. We found that activated T cells secrete IL-10 following interaction with MDSCs which, in turn, activates STAT3 phosphorylation on MDSCs then leading to B7-H1 expression. We also demonstrated that B7-H1+ MDSCs are responsible for immune suppression through a mechanism involving ARG-1 and IDO expression. Finally, we show that the expression of ligands B7-H1 and MHC class II both on in vitro-induced MDSCs and on MDSCs in the tumor microenvironment of cancer patients is paralleled by an increased expression of their respective receptors PD-1 and LAG-3 on T cells, two inhibitory molecules associated with T cell dysfunction. These findings highlight key molecules and interactions responsible for the extensive cross-talk between MDSCs and activated T cells that are at the basis of immune suppression.

  17. NKT cell self-reactivity: evolutionary master key of immune homeostasis?

    Institute of Scientific and Technical Information of China (English)

    Shohreh Issazadeh-Navikas

    2012-01-01

    Complex immune responses have evolved to protect multicellular organisms against the invasion of pathogens.This has exerted strong developmental pressure for specialized functions that can also limit damage to self-tissue.Two arms of immunity,the innate and adaptive immune systems,have evolved for quick,non-specific immune responses to pathogens and more efficient,long-lasting ones upon specific recognition of recurrent pathogens.Specialized cells have arisen as the sentinels of these functions,including macrophages,natural killer (NK),and T and B-lymphocytes.Interestingly,a population of immune cells that can exert both of these complex functions,NKT cells,not only share common functions but also exhibit shared cell surface markers of cells of both arms of the Immune system.These features,in combination with sophisticated maintenance of immune homeostasis,will be discussed.The recent finding of self-peptide reactivity of NKT cells in the context of CD1d,with capacity to regulate multiple autoimmune and inflammatory conditions,motivates the current proposal that self-reactive NKT cells might be the ancestral link between present NK and T cells.Their parallel selection through evolution by higher vertebrates could be related to their central function as master regulators of immune homeostasis that in part is shared with regulatory T cells,Hypothetical views on how self-reactive NKT cells secure such a central role will also be proposed.

  18. Neuromelanin is an immune stimulator for dendritic cells in vitro

    Directory of Open Access Journals (Sweden)

    Oberländer Uwe

    2011-11-01

    Full Text Available Abstract Background Parkinson's disease (PD is characterized at the cellular level by a destruction of neuromelanin (NM-containing dopaminergic cells and a profound reduction in striatal dopamine. It has been shown recently that anti-melanin antibodies are increased in sera of Parkinson patients, suggesting that NM may act as an autoantigen. In this study we tested whether NM is being recognized by dendritic cells (DCs, the major cell type for inducing T- and B-cell responses in vivo. This recognition of NM by DCs is a prerequisite to trigger an adaptive autoimmune response directed against NM-associated structures. Results Murine DCs were treated with NM of substantia nigra (SN from human subjects or with synthetic dopamine melanin (DAM. DCs effectively phagocytized NM and subsequently developed a mature phenotype (CD86high/MHCIIhigh. NM-activated DCs secreted the proinflammatory cytokines IL-6 and TNF-α. In addition, they potently triggered T cell proliferation in a mixed lymphocyte reaction, showing that DC activation was functional to induce a primary T cell response. In contrast, DAM, which lacks the protein and lipid components of NM but mimics the dopamine-melanin backbone of NM, had only very little effect on DC phenotype and function. Conclusions NM is recognized by DCs in vitro and triggers their maturation. If operative in vivo, this would allow the DC-mediated transport and presentation of SN antigens to the adaptive immune system, leading to autoimmmunity in susceptible individuals. Our data provide a rationale for an autoimmune-based pathomechanism of PD with NM as the initial trigger.

  19. Impairment of pneumococcal antigen specific isotype-switched Igg memory B-cell immunity in HIV infected Malawian adults.

    Directory of Open Access Journals (Sweden)

    Oluwadamilola H Iwajomo

    Full Text Available Pneumococcal disease is associated with a particularly high morbidity and mortality amongst adults in HIV endemic countries. Our previous findings implicating a B-cell defect in HIV-infected children from the same population led us to comprehensively characterize B-cell subsets in minimally symptomatic HIV-infected Malawian adults and investigate the isotype-switched IgG memory B-cell immune response to the pneumococcus. We show that similar to vertically acquired HIV-infected Malawian children, horizontally acquired HIV infection in these adults is associated with IgM memory B-cell (CD19(+ CD27(+ IgM(+ IgD(+ depletion, B-cell activation and impairment of specific IgG B-cell memory to a range of pneumococcal proteins. Our data suggest that HIV infection affects both T-cell independent and T-cell dependent B-cell maturation, potentially leading to impairment of humoral responses to extracellular pathogens such as the pneumococcus, and thus leaving this population susceptible to invasive disease.

  20. Autoimmune disease-associated variants of extracellular endoplasmic reticulum aminopeptidase 1 induce altered innate immune responses by human immune cells.

    Science.gov (United States)

    Aldhamen, Yasser A; Pepelyayeva, Yuliya; Rastall, David P W; Seregin, Sergey S; Zervoudi, Efthalia; Koumantou, Despoina; Aylsworth, Charles F; Quiroga, Dionisia; Godbehere, Sarah; Georgiadis, Dimitris; Stratikos, Efstratios; Amalfitano, Andrea

    2015-01-01

    Endoplasmic reticulum aminopeptidase 1 (ERAP1) gene polymorphisms have been linked to several autoimmune diseases; however, the molecular mechanisms underlying these associations are not well understood. Recently, we demonstrated that ERAP1 regulates key aspects of the innate immune response. Previous studies show ERAP1 to be endoplasmic reticulum-localized and secreted during inflammation. Herein, we investigate the possible roles that ERAP1 polymorphic variants may have in modulating the innate immune responses of human peripheral blood mononuclear cells (hPBMCs) using two experimental methods: extracellular exposure of hPBMCs to ERAP1 variants and adenovirus (Ad)-based ERAP1 expression. We found that exposure of hPBMCs to ERAP1 variant proteins as well as ERAP1 overexpression by Ad5 vectors increased inflammatory cytokine and chemokine production, and enhanced immune cell activation. Investigating the molecular mechanisms behind these responses revealed that ERAP1 is able to activate innate immunity via multiple pathways, including the NLRP3 (NOD-like receptor, pyrin domain-containing 3) inflammasome. Importantly, these responses varied if autoimmune disease-associated variants of ERAP1 were examined in the assay systems. Unexpectedly, blocking ERAP1 cellular internalization augmented IL-1β production. To our knowledge, this is the first report identifying ERAP1 as being involved in modulating innate responses of human immune cells, a finding that may explain why ERAP1 has been genetically associated with several autoimmune diseases. PMID:25591727

  1. GTP depletion synergizes the anti-proliferative activity of chemotherapeutic agents in a cell type-dependent manner

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Tao; Meng, Lingjun [Center for Cancer and Stem Cell Biology, Institute of Biosciences and Technology, Texas A and M Health Science Center, Houston, TX 77030 (United States); Tsai, Robert Y.L., E-mail: rtsai@ibt.tamhsc.edu [Center for Cancer and Stem Cell Biology, Institute of Biosciences and Technology, Texas A and M Health Science Center, Houston, TX 77030 (United States)

    2011-10-22

    Highlights: {yields} Strong synergy between mycophenolic acid (MPA) and 5-FU in MDA-MB-231 cells. {yields} Cell type-dependent synergy between MPA and anti-proliferative agents. {yields} The synergy of MPA on 5-FU is recapitulated by RNA polymerase-I inhibition. {yields} The synergy of MPA on 5-FU requires the expression of nucleostemin. -- Abstract: Mycophenolic acid (MPA) depletes intracellular GTP by blocking de novo guanine nucleotide synthesis. GTP is used ubiquitously for DNA/RNA synthesis and as a signaling molecule. Here, we made a surprising discovery that the anti-proliferative activity of MPA acts synergistically with specific chemotherapeutic agents in a cell type-dependent manner. In MDA-MB-231 cells, MPA shows an extremely potent synergy with 5-FU but not with doxorubicin or etoposide. The synergy between 5-FU and MPA works most effectively against the highly tumorigenic mammary tumor cells compared to the less tumorigenic ones, and does not work in the non-breast cancer cell types that we tested, with the exception of PC3 cells. On the contrary, MPA shows the highest synergy with paclitaxel but not with 5-FU in SCC-25 cells, derived from oral squamous cell carcinomas. Mechanistically, the synergistic effect of MPA on 5-FU in MDA-MB-231 cells can be recapitulated by inhibiting the RNA polymerase-I activity and requires the expression of nucleostemin. This work reveals that the synergy between MPA and anti-proliferative agents is determined by cell type-dependent factors.

  2. Anti-CD20 as the B cells targeting agent in the combined therapy to modulate anti-factor VIII immune responses in hemophilia A inhibitor mice

    Directory of Open Access Journals (Sweden)

    Chao Lien eLiu

    2014-01-01

    Full Text Available Neutralizing antibody formation against transgene products can represent a major complication following gene therapy with treatment of genetic diseases, such as hemophilia A. Although successful approaches have been developed to prevent the formation of anti-factor VIII (FVIII antibodies, innovative strategies to overcome pre-existing anti-FVIII immune responses in FVIII-primed subjects are still lacking. Anti-FVIII neutralizing antibodies circulate for long periods in part due to persistence of memory B cells. Anti-CD20 targets a variety of B cells (pre-B cells to mature/memory cells; therefore, we investigated the impact of B cell depletion on anti-FVIII immune responses in hemophilia A mice using anti-CD20 combined with regulatory T (Treg cell expansion using IL-2/IL-2mAb complexes plus rapamycin. We found that anti-CD20 alone can partially modulate anti-FVIII immune responses in both unprimed and FVIII-primed hemophilia A mice. Moreover, in mice treated with anti-CD20 + IL-2/IL-2mAb complexes + rapamycin + FVIII, anti-FVIII antibody titers were significantly reduced in comparison to mice treated with regimens targeting only B or T cells. In addition, titers remained low after a second challenge with FVIII plasmid . Treg cells and activation markers were transiently and significantly increased in the groups treated with IL-2/IL-2mAb complexes ; however,significant B cell depletion was obtained in anti-CD20-treated groups. Importantly, both FVIII-specific antibody-secreting cells and memory B cells were significantly reduced in mice treated with combination therapy. This study demonstrates that a combination regimen is highly promising as a treatment option for modulating anti-FVIII antibodies and facilitating induction of long-term tolerance to FVIII in hemophilia A mice.

  3. A novel potent Fas agonist for selective depletion of tumor cells in hematopoietic transplants

    OpenAIRE

    Nahimana, A; AUBRY, D.; Lagopoulos, L; Greaney, P.; Attinger, A; Demotz, S; Dawson, K. M.; Schapira, M; Tschopp, J; Dupuis, M.; Duchosal, M A

    2011-01-01

    There remains a clear need for effective tumor cell purging in autologous stem cell transplantation (ASCT) where residual malignant cells within the autograft contribute to disease relapse. Here we propose the use of a novel Fas agonist with potent pro-apoptotic activity, termed MegaFasL, as an effective ex-vivo purging agent. MegaFasL selectively kills hematological cancer cells from lymphomas and leukemias and prevents tumor development at concentrations that do not reduce the functional ca...

  4. Immunization with Paracoccidioides brasiliensis radioattenuated yeast cells induces Th1 immune response in Balb/C mice

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Estefania M.N.; Andrade, Antero S.R. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN-CNEN/MG), Belo Horizonte, MG (Brazil)], e-mail: estefaniabio@yahoo.com.br, e-mail: antero@cdtn.br; Resende, Maria Aparecida de [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Microbiologia], e-mail: maresend@mono.icb.ufmg.br; Reis, Bernardo S.; Goes, Alfredo M. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Bioquimica e Imunologia], e-mail: goes@mono.icb.ufmg.br, e-mail: brsgarbi@mono.icb.ufmg.br

    2009-07-01

    Paracoccidioides brasiliensis is the agent of paracoccidioidomycosis, the most prevalent mycosis in Latin America. To date, there is no effective vaccine. In our laboratory yeast cells of P. brasiliensis were attenuated by gamma irradiation. We defined an absorbed dose in which the pathogen loses the reproductive ability, while retaining the morphology, the synthesis and secretion of proteins and the oxidative metabolism. The immunization with these cells was able to confer protection in BALB/c mice. The aim of the present work was evaluate the immune response pathway activated in mice immunized with P. brasiliensis radioattenuated yeast cells. The protector effect was evaluated in BALB/c mice groups immunized once or twice, respectively. Each group was divided in three sub groups that were challenge 30, 45 or 60 days after the immunization. These groups were called G1A, G1B and G1C in the group immunized once and G2A, G2B and G2C in the group immunized twice. Recovery of CFUs and cytokines determination (IFN - {gamma}, IL - 10 and IL IV 4) were performed three months post challenge. Quantitative RT-PCR was the method of choice used to quantify the expression of cytokines. The sera were collected weekly to evaluate the IgG antibody titers and the IgG1 and IgG2a pattern in the course of infection. A significant reduction in CFUs recovery was verified 90 days post challenge in mice submitted to one immunization: 73.0%, 96.0% and 76.3% for sub-groups G1A, G1B and G1C, respectively. In the group submitted to two immunizations, a remarkable increase in the protection was obtained. No CFUs was recovered from sub-groups G2B and G2C and very few CFUs (reduction of 98.6%) were recovered from the lungs of sub group G2A. In mice submitted to one immunization, Th1 and Th2 cytokines were simultaneously produced. In the group submitted to two immunizations, levels of IL-10 and IL-4 were very low, while IFN-{gamma} production was maintained indicating that a Th1 pattern was

  5. Immunization with Paracoccidioides brasiliensis radioattenuated yeast cells induces Th1 immune response in Balb/C mice

    International Nuclear Information System (INIS)

    Paracoccidioides brasiliensis is the agent of paracoccidioidomycosis, the most prevalent mycosis in Latin America. To date, there is no effective vaccine. In our laboratory yeast cells of P. brasiliensis were attenuated by gamma irradiation. We defined an absorbed dose in which the pathogen loses the reproductive ability, while retaining the morphology, the synthesis and secretion of proteins and the oxidative metabolism. The immunization with these cells was able to confer protection in BALB/c mice. The aim of the present work was evaluate the immune response pathway activated in mice immunized with P. brasiliensis radioattenuated yeast cells. The protector effect was evaluated in BALB/c mice groups immunized once or twice, respectively. Each group was divided in three sub groups that were challenge 30, 45 or 60 days after the immunization. These groups were called G1A, G1B and G1C in the group immunized once and G2A, G2B and G2C in the group immunized twice. Recovery of CFUs and cytokines determination (IFN - γ, IL - 10 and IL IV 4) were performed three months post challenge. Quantitative RT-PCR was the method of choice used to quantify the expression of cytokines. The sera were collected weekly to evaluate the IgG antibody titers and the IgG1 and IgG2a pattern in the course of infection. A significant reduction in CFUs recovery was verified 90 days post challenge in mice submitted to one immunization: 73.0%, 96.0% and 76.3% for sub-groups G1A, G1B and G1C, respectively. In the group submitted to two immunizations, a remarkable increase in the protection was obtained. No CFUs was recovered from sub-groups G2B and G2C and very few CFUs (reduction of 98.6%) were recovered from the lungs of sub group G2A. In mice submitted to one immunization, Th1 and Th2 cytokines were simultaneously produced. In the group submitted to two immunizations, levels of IL-10 and IL-4 were very low, while IFN-γ production was maintained indicating that a Th1 pattern was dominant. For

  6. Effect of dietary bovine colostrum on the responses of immune cells to stimulation with bacterial lipopolysaccharide.

    Science.gov (United States)

    Xu, Mei Ling; Kim, Hyoung Jin; Kim, Hong-Jin

    2014-04-01

    Previous studies have revealed that ingestion of bovine colostrum is effective in preventing pathogens from invading through the gastrointestinal tract (GI) and modulating the mucosal immunity of the GI tract, indicating that its effect is principally local. Thus it is unclear if ingestion of bovine colostrum can affect the systemic immune system. In this study, we investigated the effect of taking bovine colostrum (vs phosphate-buffered saline) for 14 days on the behavior of the immune cells of mice. Isolated splenocytes, which are pivotal cells of systemic immunity, were then stimulated with Escherichia coli lipopolysaccharide. Bovine colostrum significantly reduced NK cell and monocyte activities and lymphoproliferaltive responses to LPS stimulation. Thus dietary bovine colostrum renders immune cells less responsive to LPS stimulation. Dietary bovine colostrum thus affects the systemic immune system and may have anti-inflammatory actions. PMID:24234910

  7. Depletion of eIF4G from yeast cells narrows the range of translational efficiencies genome-wide

    Directory of Open Access Journals (Sweden)

    Hinnebusch Alan G

    2011-01-01

    Full Text Available Abstract Background Eukaryotic translation initiation factor 4G (eIF4G is thought to influence the translational efficiencies of cellular mRNAs by its roles in forming an eIF4F-mRNA-PABP mRNP that is competent for attachment of the 43S preinitiation complex, and in scanning through structured 5' UTR sequences. We have tested this hypothesis by determining the effects of genetically depleting eIF4G from yeast cells on global translational efficiencies (TEs, using gene expression microarrays to measure the abundance of mRNA in polysomes relative to total mRNA for ~5900 genes. Results Although depletion of eIF4G is lethal and reduces protein synthesis by ~75%, it had small effects (less than a factor of 1.5 on the relative TE of most genes. Within these limits, however, depleting eIF4G narrowed the range of translational efficiencies genome-wide, with mRNAs of better than average TE being translated relatively worse, and mRNAs with lower than average TE being translated relatively better. Surprisingly, the fraction of mRNAs most dependent on eIF4G display an average 5' UTR length at or below the mean for all yeast genes. Conclusions This finding suggests that eIF4G is more critical for ribosome attachment to mRNAs than for scanning long, structured 5' UTRs. Our results also indicate that eIF4G, and the closed-loop mRNP it assembles with the m7 G cap- and poly(A-binding factors (eIF4E and PABP, is not essential for translation of most (if not all mRNAs but enhances the differentiation of translational efficiencies genome-wide.

  8. T-cell depletion and autologous stem cell transplantation in the management of tumour stage mycosis fungoides with peripheral blood involvement.

    Science.gov (United States)

    Olavarria, E; Child, F; Woolford, A; Whittaker, S J; Davis, J G; McDonald, C; Chilcott, S; Spittle, M; Grieve, R J; Stewart, S; Apperley, J F; Russell-Jones, R

    2001-09-01

    Nine patients with tumour stage mycosis fungoides (MF) have been entered into a pilot study of T-cell depletion and autologous stem cell transplantation (SCT). Eight patients had detectable rearrangements of the T-cell receptor (TCR) gamma-gene demonstrated by polymerase chain reaction (PCR)/single-stranded conformation polymorphism (SSCP) in the peripheral blood. The median age was 47 years and the median duration of disease before SCT was 61 months; Peripheral blood progenitor cells were mobilized using high-dose etoposide (1.6 g/m2) and granulocyte colony-stimulating factor (G-CSF). The apheresis products underwent rigorous T-cell depletion with immunomagnetic methods. Double CD34-positive and CD4/CD8-negative selection achieved a median reduction of 3.89 log of T cells. All nine patients have been transplanted. Conditioning included carmustine (BCNU), etoposide and melphalan (BEM) in seven patients and total body irradiation plus etoposide or melphalan in two. Eight patients engrafted promptly and one patient died of septicaemia. All survivors entered complete remission. Seven patients have relapsed at a median of 7 months (2-14) post SCT. However, most patients have relapsed into a less aggressive stage, which has responded to conventional therapy. Four out of seven evaluable patients had detectable TCR rearrangements in the T-cell depleted graft. A T-cell clone was also detected in the peripheral blood before relapse in four cases. Autologous SCT is feasible, safe and can result in complete remission in a significant proportion of patients with tumour stage mycosis fungoides. Despite a short relapse-free survival, most patients achieved good disease control at the time of relapse.

  9. Dose-Dependent ATP Depletion and Cancer Cell Death following Calcium Electroporation, Relative Effect of Calcium Concentration and Electric Field Strength

    OpenAIRE

    Hansen, Emilie Louise; Sozer, Esin Bengisu; Romeo, Stefania; Frandsen, Stine Krog; Vernier, P. Thomas; Gehl, Julie

    2015-01-01

    Background Electroporation, a method for increasing the permeability of membranes to ions and small molecules, is used in the clinic with chemotherapeutic drugs for cancer treatment (electrochemotherapy). Electroporation with calcium causes ATP (adenosine triphosphate) depletion and cancer cell death and could be a novel cancer treatment. This study aims at understanding the relationship between applied electric field, calcium concentration, ATP depletion and efficacy. Methods In three human ...

  10. Dendritic cell biology in human cytomegalovirus infection and the clinical consequences for host immunity and pathology

    OpenAIRE

    Gredmark-Russ, Sara; Söderberg-Nauclér, Cecilia

    2012-01-01

    Human cytomegalovirus (HCMV), a member of the herpesvirus family, establishes life-long persistence and latency after primary infection and can be reactivated later in life. In immunosuppressed patients, it is an important pathogen that can cause severe disease. HCMV is also thought to play a causative role in inflammatory diseases and cancer. The virus can infect different immune cells, including dendritic cells (DCs) and can take advantage of host immune functions to avoid immune recognitio...

  11. Th17 cells confer long term adaptive immunity to oral mucosal Candida albicans infections

    OpenAIRE

    Hernández-Santos, Nydiaris; Huppler, Anna R; Peterson, Alanna C.; Khader, Shabaana A.; McKenna, Kyle C.; Sarah L Gaffen

    2012-01-01

    Oropharyngeal candidiasis (OPC) is an opportunistic infection caused by Candida albicans. Despite its prevalence, little is known about C. albicans-specific immunity in the oral mucosa. Vaccines against Candida generate both Th1 and Th17 responses, and considerable evidence implicates IL-17 in immunity to OPC. However, IL-17 is also produced by innate immune cells that are remarkably similar to Th17 cells, expressing the same markers and localizing to similar mucosal sites. To date, the relat...

  12. Childhood adversity and cell-mediated immunity in young adulthood: Does type and timing matter?

    OpenAIRE

    Slopen, Natalie; McLaughlin, Katie A.; Erin C Dunn; Koenen, Karestan C.

    2012-01-01

    Childhood adversity can have powerful effects on health over the life course. Persistent changes in cell-mediated immune function may be one pathway linking adverse childhood experiences with later disease risk. However, limited research has examined childhood adversity in relation to cell-mediated immune function, and in particular, immune response to latent viruses in adulthood. The present study investigated the association of two types of childhood adversity, socioeconomic disadvantage du...

  13. Increased intratumoral FOXP3-positive regulatory immune cells during interleukin-2 treatment in metastatic renal cell carcinoma

    DEFF Research Database (Denmark)

    Jensen, Hanne Krogh; Donskov, Frede; Nordsmark, Marianne;

    2009-01-01

    tumor-infiltrating immune cells at baseline and during treatment (P 180 cells/mm2) of on-treatment FOXP3-positive intratumoral immune cells were dead within 22 months (n = 11), whereas patients with low numbers (cells/mm2) of on-treatment......PURPOSE: The administration of interleukin-2 (IL-2) may increase the frequency of peripherally circulating FOXP3-positive regulatory immune cells, thus potentially compromising this treatment option for patients with metastatic renal cell carcinoma. The impact of IL-2-based therapy...... on the accumulation of FOXP3-positive immune cells in the tumor microenvironment in metastatic renal cell carcinoma is unknown. EXPERIMENTAL DESIGN: Baseline (n = 58) and on-treatment (n = 42) tumor core biopsies were prospectively obtained from patients with clear cell metastatic renal cell carcinoma before...

  14. Effect of bacillus Calmette-Guérin vaccination on CD4+Foxp3+ T cells during acquired immune response to Mycobacterium tuberculosis infection.

    Science.gov (United States)

    Henao-Tamayo, Marcela I; Obregón-Henao, Andres; Arnett, Kimberly; Shanley, Crystal A; Podell, Brendan; Orme, Ian M; Ordway, Diane J

    2016-04-01

    Increasing information has shown that many newly emerging strains of Mycobacterium tuberculosis, including the highly prevalent and troublesome Beijing family of strains, can potently induce the emergence of Foxp3(+)CD4 Tregs Although the significance of this is still not fully understood, we have previously provided evidence that the emergence of this population can significantly ablate the protective effect of BCG vaccination, causing progressive fatal disease in the mouse model. However, whether the purpose of this response is to control inflammation or to directly dampen the acquired immune response is still unclear. In the present study, we have shown, using both cell depletion and adoptive transfer strategies, that Tregs can have either properties. Cell depletion resulted in a rapid, but transient, decrease in the lung bacterial load, suggesting release or temporary re-expansion of effector immunity. Transfer of Tregs into Rag2(-/-)or marked congenic mice worsened the disease course and depressed cellular influx of effector T cells into the lungs. Tregs from infected donors seemed to preferentially depress the inflammatory response and granulocytic influx. In contrast, those from BCG-vaccinated and then challenged donors seemed more focused on depression of acquired immunity. These qualitative differences might be related to increasing knowledge reflecting the plasticity of the Treg response.

  15. The 3 major types of innate and adaptive cell-mediated effector immunity.

    Science.gov (United States)

    Annunziato, Francesco; Romagnani, Chiara; Romagnani, Sergio

    2015-03-01

    The immune system has tailored its effector functions to optimally respond to distinct species of microbes. Based on emerging knowledge on the different effector T-cell and innate lymphoid cell (ILC) lineages, it is clear that the innate and adaptive immune systems converge into 3 major kinds of cell-mediated effector immunity, which we propose to categorize as type 1, type 2, and type 3. Type 1 immunity consists of T-bet(+) IFN-γ-producing group 1 ILCs (ILC1 and natural killer cells), CD8(+) cytotoxic T cells (TC1), and CD4(+) TH1 cells, which protect against intracellular microbes through activation of mononuclear phagocytes. Type 2 immunity consists of GATA-3(+) ILC2s, TC2 cells, and TH2 cells producing IL-4, IL-5, and IL-13, which induce mast cell, basophil, and eosinophil activation, as well as IgE antibody production, thus protecting against helminthes and venoms. Type 3 immunity is mediated by retinoic acid-related orphan receptor γt(+) ILC3s, TC17 cells, and TH17 cells producing IL-17, IL-22, or both, which activate mononuclear phagocytes but also recruit neutrophils and induce epithelial antimicrobial responses, thus protecting against extracellular bacteria and fungi. On the other hand, type 1 and 3 immunity mediate autoimmune diseases, whereas type 2 responses can cause allergic diseases. PMID:25528359

  16. Toxicological studies of semiconductor quantum dots on immune cells.

    Energy Technology Data Exchange (ETDEWEB)

    Ricken, James Bryce; Rios, Lynette; Poschet, Jens Fredrich; Bachand, Marlene; Bachand, George David; Greene, Adrienne Celeste; Carroll-Portillo, Amanda

    2008-11-01

    Nanoengineered materials hold a vast promise of enabling revolutionary technologies, but also pose an emerging and potentially serious threat to human and environmental health. While there is increasing knowledge concerning the risks posed by engineered nanomaterials, significant inconsistencies exist within the current data based on the high degree of variability in the materials (e.g., synthesis method, coatings, etc) and biological test systems (e.g., cell lines, whole organism, etc). In this project, we evaluated the uptake and response of two immune cell lines (RAW macrophage and RBL mast cells) to nanocrystal quantum dots (Qdots) with different sizes and surface chemistries, and at different concentrations. The basic experimental design followed a 2 x 2 x 3 factorial model: two Qdot sizes (Qdot 520 and 620), two surface chemistries (amine 'NH{sub 2}' and carboxylic acid 'COOH'), and three concentrations (0, 1 nM, and 1 {micro}M). Based on this design, the following Qdots from Evident Technologies were used for all experiments: Qdot 520-COOH, Qdot 520-NH{sub 2}, Qdot 620-COOH, and Qdot 620-NH{sub 2}. Fluorescence and confocal imaging demonstrated that Qdot 620-COOH and Qdot 620-NH{sub 2} nanoparticles had a greater level of internalization and cell membrane association in RAW and RBL cells, respectively. From these data, a two-way interaction between Qdot size and concentration was observed in relation to the level of cellular uptake in RAW cells, and association with RBL cell membranes. Toxicity of both RBL and RAW cells was also significantly dependent on the interaction of Qdot size and concentration; the 1 {micro}M concentrations of the larger, Qdot 620 nanoparticles induced a greater toxic effect on both cell lines. The RBL data also demonstrate that Qdot exposure can induce significant toxicity independent of cellular uptake. A significant increase in TNF-{alpha} and decrease in IL-10 release was observed in RAW cells, and suggested

  17. Expression of VEGF in urinary bladder transitional cell carcinoma in an Iraqi population subjected to depleted uranium: an immunohistochemical study.

    Science.gov (United States)

    Al-Abbasi, Dhafer S; Al-Janabi, As'ad A; Al-Toriahi, Kaswer M; Jabor, Thekra A; Yasseen, Akeel A

    2009-07-01

    The present study aimed to assess the correlation between vascular endothelial growth factor (VEGF) overexpression and the grade, size, and recurrence of transitional cell carcinoma (TCC) in the south of Iraq, which includes regions that have been exposed to high levels of depleted uranium. The study also sought to evaluate whether there is any biomarker in the expression that could be correlated with the increased incidence of this type of cancer in the exposed areas. Samples of formalin-fixed and paraffin-embedded tissue from 54 patients (41 males and 13 females) with TCC and from 32 patients with benign bladder lesions (cystitis) used as controls were included in this study. The avidin-biotin complex method was used for immunohistochemical detection of VEGF. VEGF immunoexpression was positive in 77.77% of TCC but was not found in benign bladder lesions (cystitis) (P0.05). These findings support the role of VEGF in the carcinogenesis of TCC regarding evolution, behavior, and aggressiveness. Hence, VEGF could be considered as a poor prognostic parameter in bladder cancer. No positive correlation between immunohistochemical expression and the high incidence of TCC was detected (R=depleted uranium. PMID:19151604

  18. Modulation of the chicken immune cell function by dietary polyunsaturated fatty acids

    NARCIS (Netherlands)

    Sijben, J.W.C.

    2002-01-01

    Polyunsaturated fatty acids (PUFA) possess a wide range of biological properties, including immunomodulation. The amount, type, and ratio of dietary PUFA determine the types of fatty acids that are incorporated into immune cell membranes. Consequently, the physiological properties of immune cells an

  19. Discovering naturally processed antigenic determinants that confer protective T cell immunity

    DEFF Research Database (Denmark)

    Gilchuk, Pavlo; Spencer, Charles T; Conant, Stephanie B;

    2013-01-01

    CD8+ T cells (TCD8) confer protective immunity against many infectious diseases, suggesting that microbial TCD8 determinants are promising vaccine targets. Nevertheless, current T cell antigen identification approaches do not discern which epitopes drive protective immunity during active infectio...

  20. Tetraspanin-3 regulates protective immunity against Eimera tenella infection following immunization with dendritic cell-derived exosomes

    Science.gov (United States)

    The effects of immunization with dendritic cell (DC) exosomes, which had been incubated or non-incubated with an anti-tetraspanin-3 (Tspan-3) blocking antibody (Ab), were studied using an experimental model of Eimeria tenella avian coccidiosis. Purified exosomes from cecal tonsil and splenic DCs exp...

  1. Humoral and cell-mediated immune responses in DNA immunized mink challenged with wild-type canine distemper virus

    DEFF Research Database (Denmark)

    Nielsen, Line; Søgaard, Mette; Karlskov-Mortensen, Peter;

    2009-01-01

    is still a problem worldwide. The broad host range of CDV creates a constant viral reservoir among wildlife animals. Our results demonstrated early humoral and cell-mediated immune responses (IFN-gamma) in DNA vaccinated mink compared to mock-vaccinated mink after challenge with a Danish wild-type CDV...

  2. Effects of microcin B17 on microcin B17-immune cells.

    Science.gov (United States)

    Herrero, M; Kolter, R; Moreno, F

    1986-02-01

    When microcin B17-immune cells are treated with microcin B17 they show many of the physiological effects displayed by microcin B17-sensitive cells treated in the same way. DNA replication stops immediately and several SOS functions are subsequently induced. In sensitive cells these effects are irreversible and lead to cell death, whereas in immune cells they are reversible and there is no loss of viability. This is an unusual mechanism of immunity because it does not prevent the primary action of the microcin. The implications of this mechanism concerning the mode of action of microcin B17 and the induction of the SOS system are discussed.

  3. Alefacept promotes immunosuppression-free renal allograft survival in nonhuman primates via depletion of recipient memory T cells.

    Science.gov (United States)

    Lee, S; Yamada, Y; Tonsho, M; Boskovic, S; Nadazdin, O; Schoenfeld, D; Cappetta, K; Atif, M; Smith, R-N; Cosimi, A B; Benichou, G; Kawai, T

    2013-12-01

    Renal allograft tolerance has been achieved in MHC-mismatched primates via nonmyeloablative conditioning beginning 6 days prior to planned kidney and donor bone marrow transplantation (DBMT). To extend the applicability of this approach to deceased donor transplantation, we recently developed a novel-conditioning regimen, the "delayed protocol" in which donor bone marrow (DBM) is transplanted several months after kidney transplantation. However, activation/expansion of donor-reactive CD8(+) memory T cells (TMEM) occurring during the interval between kidney and DBM transplantation impaired tolerance induction using this strategy. In the current study, we tested whether, Alefacept, a fusion protein which targets LFA-3/CD2 interactions and selectively depletes CD2(high) CD8(+) effector memory T cells (TEM) could similarly induce long-term immunosuppression-free renal allograft survival but avoid the deleterious effects of anti-CD8 mAb treatment. We found that Alefacept significantly delayed the expansion of CD2(high) cells including CD8(+) TEM while sparing naïve CD8(+) T and NK cells and achieved mixed chimerism and long-term immunosuppression-free renal allograft survival. In conclusion, elimination of CD2(high) T cells represents a promising approach to prevent electively the expansion/activation of donor-reactive TEM and promotes tolerance induction via the delayed protocol mixed chimerism approach.

  4. RAGE regulates immune cell infiltration and angiogenesis in choroidal neovascularization.

    Directory of Open Access Journals (Sweden)

    Mei Chen

    Full Text Available PURPOSE: RAGE regulates pro-inflammatory responses in diverse cells and tissues. This study has investigated if RAGE plays a role in immune cell mobilization and choroidal neovascular pathology that is associated with the neovascular form of age-related macular degeneration (nvAMD. METHODS: RAGE null (RAGE-/- mice and age-matched wild type (WT control mice underwent laser photocoagulation to generate choroidal neovascularization (CNV lesions which were then analyzed for morphology, S100B immunoreactivity and inflammatory cell infiltration. The chemotactic ability of bone marrow derived macrophages (BMDMs towards S100B was investigated. RESULTS: RAGE expression was significantly increased in the retina during CNV of WT mice (p<0.001. RAGE-/- mice exhibited significantly reduced CNV lesion size when compared to WT controls (p<0.05. S100B mRNA was upregulated in the lasered WT retina but not RAGE-/- retina and S100B immunoreactivity was present within CNV lesions although levels were less when RAGE-/- mice were compared to WT controls. Activated microglia in lesions were considerably less abundant in RAGE-/- mice when compared to WT counterparts (p<0.001. A dose dependent chemotactic migration was observed in BMDMs from WT mice (p<0.05-0.01 but this was not apparent in cells isolated from RAGE-/- mice. CONCLUSIONS: RAGE-S100B interactions appear to play an important role in CNV lesion formation by regulating pro-inflammatory and angiogenic responses. This study highlights the role of RAGE in inflammation-mediated outer retinal pathology.

  5. A novel, blocking, Fc-silent anti-CD40 monoclonal antibody prolongs nonhuman primate renal allograft survival in the absence of B cell depletion.

    Science.gov (United States)

    Cordoba, F; Wieczorek, G; Audet, M; Roth, L; Schneider, M A; Kunkler, A; Stuber, N; Erard, M; Ceci, M; Baumgartner, R; Apolloni, R; Cattini, A; Robert, G; Ristig, D; Munz, J; Haeberli, L; Grau, R; Sickert, D; Heusser, C; Espie, P; Bruns, C; Patel, D; Rush, J S

    2015-11-01

    CD40-CD154 pathway blockade prolongs renal allograft survival in nonhuman primates (NHPs). However, antibodies targeting CD154 were associated with an increased incidence of thromboembolic complications. Antibodies targeting CD40 prolong renal allograft survival in NHPs without thromboembolic events but with accompanying B cell depletion, raising the question of the relative contribution of B cell depletion to the efficacy of anti-CD40 blockade. Here, we investigated whether fully silencing Fc effector functions of an anti-CD40 antibody can still promote graft survival. The parent anti-CD40 monoclonal antibody HCD122 prolonged allograft survival in MHC-mismatched cynomolgus monkey renal allograft transplantation (52, 22, and 24 days) with accompanying B cell depletion. Fc-silencing yielded CFZ533, an antibody incapable of B cell depletion but still able to potently inhibit CD40 pathway activation. CFZ533 prolonged allograft survival and function up to a defined protocol endpoint of 98-100 days (100, 100, 100, 98, and 76 days) in the absence of B cell depletion and preservation of good histological graft morphology. CFZ533 was well-tolerated, with no evidence of thromboembolic events or CD40 pathway activation and suppressed a gene signature associated with acute rejection. Thus, use of the Fc-silent anti-CD40 antibody CFZ533 appears to be an attractive approach for preventing solid organ transplant rejection.

  6. The Roles of Innate Immune Cells in Liver Injury and Regeneration

    Institute of Scientific and Technical Information of China (English)

    Zhongjun Dong; Haiming Wei; Rui Sun; Zhigang Tian

    2007-01-01

    For predominant abundance with liver-specific Kupffer cells, natural killer (NK) cells, and natural killer T (NKT)cells and their rapid responses to several stimuli, the liver is considered as an organ with innate immune features.In contrast to their roles in the defense of many infectious agents like hepatitis viruses and parasites, hepatic innate immune cells are also involved in the immunopathogenesis of human clinical liver diseases and several murine hepatitis models such as concanavalin A (Con A), lipopolysaccharide (LPS), or polyinosinic-polycytidylic acid (Poly I:C)-induced liver injury. In this review, the destructive roles of NK cells, NKT cells and Kupffer cells in the processes of immune-mediated liver injury and regeneration will be discussed, and some putative mechanisms involving the impairment of liver regeneration caused by activated hepatic innate immune cells are also proposed.

  7. Maternal Milk T Cells Drive Development of Transgenerational Th1 Immunity in Offspring Thymus.

    Science.gov (United States)

    Ghosh, Mrinal K; Nguyen, Virginia; Muller, H Konrad; Walker, Ameae M

    2016-09-15

    Using multiple murine foster-nursing protocols, thereby eliminating placental transfer and allowing a distinction between dam- and pup-derived cells, we show that foster nursing by an immunized dam results in development of CD8(+) T cells in nonimmunized foster pups that are specific for Ags against which the foster dam was immunized (Mycobacterium tuberculosis or Candida albicans). We have dubbed this process "maternal educational immunity" to distinguish it from passive cellular immunity. Of the variety of maternal immune cells present in milk, only T cells were detected in pup tissues. Maternal T cells, a substantial percentage of which were CD4(+)MHC class II(+), accumulated in the pup thymus and spleen during the nursing period. Further analysis of maternal cells in the pup thymus showed that a proportion was positive for maternal immunogen-specific MHC class II tetramers. To determine the outcome of Ag presentation in the thymus, the maternal or foster pup origin of immunogen-responding CD8(+) cells in foster pup spleens was assessed. Whereas ∼10% were maternally derived in the first few weeks after weaning, all immunogen-responding CD8(+) T cells were pup derived by 12 wk of age. Pup-derived immunogen-responsive CD8(+) cells persisted until at least 1 y of age. Passive cellular immunity is well accepted and has been demonstrated in the human population. In this study, we show an arguably more important role for transferred immune cells: the direction of offspring T cell development. Harnessing maternal educational immunity through prepregnancy immunization programs has potential for improvement of infant immunity. PMID:27496970

  8. Lawsonia intracellularis infection of intestinal crypt cells is associated with specific depletion of secreted MUC2 in goblet cells

    OpenAIRE

    Bengtsson, Rebecca J.; MacIntyre, Neil; Guthrie, Jack; Wilson, Alison D.; Finlayson, Heather; Matika, Oswald; Pong-Wong, Ricardo; Smith, Sionagh H; Archibald, Alan L.; Ait-Ali, Tahar

    2015-01-01

    The expression patterns of secreted (MUC2 and MUC5AC) and membrane-tethered (MUC1, MUC4, MUC12 and MUC13) mucins were monitored in healthy pigs and pigs challenged orally with Lawsonia intracellularis. These results showed that the regulation of mucin gene expression is distinctive along the GI tract of the healthy pig, and may reflect an association between the function of the mucin subtypes and different physiological demands at various sites. We identified a specific depletion of secreted ...

  9. Immunotherapy: Shifting the Balance of Cell-Mediated Immunity and Suppression in Human Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Jeffrey Schlom

    2012-12-01

    Full Text Available Active immunotherapy is dependent on the ability of the immune system to recognize and respond to tumors. Despite overwhelming evidence to support a cell-mediated immune response to prostate cancer, it is insufficient to eradicate the disease. This is likely due to a high level of suppression at the tumor site from a variety of sources, including immunosuppressive cells. Immune cells entering the tumor microenvironment may be inhibited directly by the tumor, stromal cells or other immune cells that have been induced to adopt a suppressive phenotype. The resurgence of interest in immunotherapy following the approval of sipuleucel-T and ipilimumab by the Food and Drug Administration has brought about new strategies for overcoming tumor-mediated suppression and bolstering anti-tumor responses. Improved understanding of the immune response to prostate cancer can lead to new combination therapies, such as the use of vaccine with small molecule and checkpoint inhibitors or other immunotherapies.

  10. Immunotherapy: Shifting the Balance of Cell-Mediated Immunity and Suppression in Human Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Tucker, Jo A.; Jochems, Caroline [Laboratory of Tumor Immunology and Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892 (United States); Gulley, James L. [Laboratory of Tumor Immunology and Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892 (United States); Medical Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892 (United States); Schlom, Jeffrey, E-mail: js141c@nih.gov; Tsang, Kwong Y. [Laboratory of Tumor Immunology and Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892 (United States)

    2012-12-11

    Active immunotherapy is dependent on the ability of the immune system to recognize and respond to tumors. Despite overwhelming evidence to support a cell-mediated immune response to prostate cancer, it is insufficient to eradicate the disease. This is likely due to a high level of suppression at the tumor site from a variety of sources, including immunosuppressive cells. Immune cells entering the tumor microenvironment may be inhibited directly by the tumor, stromal cells or other immune cells that have been induced to adopt a suppressive phenotype. The resurgence of interest in immunotherapy following the approval of sipuleucel-T and ipilimumab by the Food and Drug Administration has brought about new strategies for overcoming tumor-mediated suppression and bolstering anti-tumor responses. Improved understanding of the immune response to prostate cancer can lead to new combination therapies, such as the use of vaccine with small molecule and checkpoint inhibitors or other immunotherapies.

  11. Immunotherapy: Shifting the Balance of Cell-Mediated Immunity and Suppression in Human Prostate Cancer

    International Nuclear Information System (INIS)

    Active immunotherapy is dependent on the ability of the immune system to recognize and respond to tumors. Despite overwhelming evidence to support a cell-mediated immune response to prostate cancer, it is insufficient to eradicate the disease. This is likely due to a high level of suppression at the tumor site from a variety of sources, including immunosuppressive cells. Immune cells entering the tumor microenvironment may be inhibited directly by the tumor, stromal cells or other immune cells that have been induced to adopt a suppressive phenotype. The resurgence of interest in immunotherapy following the approval of sipuleucel-T and ipilimumab by the Food and Drug Administration has brought about new strategies for overcoming tumor-mediated suppression and bolstering anti-tumor responses. Improved understanding of the immune response to prostate cancer can lead to new combination therapies, such as the use of vaccine with small molecule and checkpoint inhibitors or other immunotherapies

  12. Virulent Salmonella enterica serovar typhimurium evades adaptive immunity by preventing dendritic cells from activating T cells.

    Science.gov (United States)

    Tobar, Jaime A; Carreño, Leandro J; Bueno, Susan M; González, Pablo A; Mora, Jorge E; Quezada, Sergio A; Kalergis, Alexis M

    2006-11-01

    Dendritic cells (DCs) constitute the link between innate and adaptive immunity by directly recognizing pathogen-associated molecular patterns (PAMPs) in bacteria and by presenting bacterial antigens to T cells. Recognition of PAMPs renders DCs as professional antigen-presenting cells able to prime naïve T cells and initiate adaptive immunity against bacteria. Therefore, interfering with DC function would promote bacterial survival and dissemination. Understanding the molecular mechanisms that have evolved in virulent bacteria to evade activation of adaptive immunity requires the characterization of virulence factors that interfere with DC function. Salmonella enterica serovar Typhimurium, the causative agent of typhoid-like disease in the mouse, can prevent antigen presentation to T cells by avoiding lysosomal degradation in DCs. Here, we show that this feature of virulent Salmonella applies in vivo to prevent activation of adaptive immunity. In addition, this attribute of virulent Salmonella requires functional expression of a type three secretion system (TTSS) and effector proteins encoded within the Salmonella pathogenicity island 2 (SPI-2). In contrast to wild-type virulent Salmonella, mutant strains carrying specific deletions of SPI-2 genes encoding TTSS components or effectors proteins are targeted to lysosomes and are no longer able to prevent DCs from activating T cells in vitro or in vivo. SPI-2 mutant strains are attenuated in vivo, showing reduced tissue colonization and enhanced T-cell activation, which confers protection against a challenge with wild-type virulent Salmonella. Our data suggest that impairment of DC function by the activity of SPI-2 gene products is crucial for Salmonella pathogenesis.

  13. rRNA maturation in yeast cells depleted of large ribosomal subunit proteins.

    Directory of Open Access Journals (Sweden)

    Gisela Pöll

    Full Text Available The structural constituents of the large eukaryotic ribosomal subunit are 3 ribosomal RNAs, namely the 25S, 5.8S and 5S rRNA and about 46 ribosomal proteins (r-proteins. They assemble and mature in a highly dynamic process that involves more than 150 proteins and 70 small RNAs. Ribosome biogenesis starts in the nucleolus, continues in the nucleoplasm and is completed after nucleo-cytoplasmic translocation of the subunits in the cytoplasm. In this work we created 26 yeast strains, each of which conditionally expresses one of the large ribosomal subunit (LSU proteins. In vivo depletion of the analysed LSU r-proteins was lethal and led to destabilisation and degradation of the LSU and/or its precursors. Detailed steady state and metabolic pulse labelling analyses of rRNA precursors in these mutant strains showed that LSU r-proteins can be grouped according to their requirement for efficient progression of different steps of large ribosomal subunit maturation. Comparative analyses of the observed phenotypes and the nature of r-protein-rRNA interactions as predicted by current atomic LSU structure models led us to discuss working hypotheses on i how individual r-proteins control the productive processing of the major 5' end of 5.8S rRNA precursors by exonucleases Rat1p and Xrn1p, and ii the nature of structural characteristics of nascent LSUs that are required for cytoplasmic accumulation of nascent subunits but are nonessential for most of the nuclear LSU pre-rRNA processing events.

  14. Study on Effect of Aloe Glue on Cytogenetics, Cellular Immunity and Cell Proliferation of Human Cells

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jiahua; WEN Shaluo; XIA Yun; ZHANG Lijun

    2002-01-01

    Objective To provide the scientific evidence for the exploiture of aloe resource. Methods Cytological combined determination was used to study the effect of aloe glue(0.01 ~ 0.3ml) on cytogenetics, cellular immunity and cell proliferation of human cells. Results SCE and MNR in varying dose groups had no significant differences as compared with control group( P > 0.05). LTR was significantly higher than that of control group(P < 0.005). MI was significantly higher than that of control group ( P < 0.05). M3 and PRI in highest dose group had significant differences as compared with control group (P < 0.05). Conclusion Aloe gel had no significant effect on cytogenetics. But it had activating effects on immunity and proliferation of cells.

  15. Co-Regulated Pendrin and Aquaporin 5 Expression and Trafficking in Type-B Intercalated Cells under Potassium Depletion

    Directory of Open Access Journals (Sweden)

    Giuseppe Procino

    2013-12-01

    Full Text Available Background: We recently reported that aquaporin 5 (AQP5, a water channel never identified in the kidney before, co-localizes with pendrin at the apical membrane of type-B intercalated cells in the kidney cortex. Since co-expression of AQP5 and pendrin in the apical membrane domain is a common feature of several other epithelia such as cochlear and bronchial epithelial cells, we evaluated here whether this strict membrane association may reflect a co-regulation of the two proteins. To investigate this possibility, we analyzed AQP5 and pendrin expression and trafficking in mice under chronic K+ depletion, a condition that results in an increased ability of renal tubule to reabsorb bicarbonate, often leads to metabolic alkalosis and is known to strongly reduce pendrin expression. Methods: Mice were housed in metabolic cages and pair-fed with either a standard laboratory chow or a K+-deficient diet. AQP5 abundance was assessed by western blot in whole kidney homogenates and AQP5 and pendrin were localized by confocal microscopy in kidney sections from those mice. In addition, the short-term effect of changes in external pH on pendrin trafficking was evaluated by fluorescence resonance energy transfer (FRET in MDCK cells, and the functional activity of pendrin was tested in the presence and absence of AQP5 in HEK 293 Phoenix cells. Results: Chronic K+ depletion caused a strong reduction in pendrin and AQP5 expression. Moreover, both proteins shifted from the apical cell membrane to an intracellular compartment. An acute pH shift from 7.4 to 7.0 caused pendrin internalization from the plasma membrane. Conversely, a pH shift from 7.4 to 7.8 caused a significant increase in the cell surface expression of pendrin. Finally, pendrin ion transport activity was not affected by co-expression with AQP5. Conclusions: The co-regulation of pendrin and AQP5 membrane expression under chronic K+-deficiency indicates that these two molecules could cooperate as an

  16. Alarming Oxygen Depletion Caused by Hydrogen Combustion and Fuel Cells and their Resolution by Magnegas$^{TM}$

    CERN Document Server

    Santilli, R M

    2000-01-01

    We recall that hydrogen combustion does resolve the environmental problems of fossil fuels due to excessive emission of carcinogenic substances and carbon dioxide. However, hydrogen combustion implies the permanent removal from our atmosphere of directly usable oxygen, a serious environmental problem called oxygen depletion, since the combustion turns oxygen into water whose separation to restore the original oxygen is prohibitive due to cost. We then show that a conceivable global use of hydrogen in complete replacement of fossil fuels would imply the permanent removal from our atmosphere of 2.8875x10^7 metric tons O_2/day. Fuel cells are briefly discussed to point out similarly serious environmental problems, again, for large uses. We propose the possibility of resolving these problems by upgrading hydrogen to the new combustible fuel called magnegas^TM, whose chemical structure is composed by the new chemical species of magnecules, whose energy content and other features are beyond the descriptive capaciti...

  17. Interfacial quality improvement of Cu(In,Ga)Se2 thin film solar cells by Cu-depletion layer formation

    Science.gov (United States)

    Nishimura, Takahito; Toki, Soma; Sugiura, Hiroki; Nakada, Kazuyoshi; Yamada, Akira

    2016-09-01

    Se irradiation with time, t Se, was introduced after the second stage of a three-stage process to control the Cu2Se layer during Cu(In,Ga)Se2 (CIGS) deposition. Open circuit voltage and fill factor of CIGS solar cells could be improved by introducing Se irradiation. We concluded that the control of the Cu2Se layer led to the formation of a Cu-depletion CIGS layer (CDL), which improved conversion efficiency owing to suppression of interfacial recombination by a valence band offset formed between CIGS and the CDL. Finally, highest efficiency of 19.8% was achieved with t Se of 5 min. This very simple and new technique is promising for the improvement of photovoltaic performance.

  18. Helminth Protein Vaccine Induced Follicular T Helper Cell for Enhancement of Humoral Immunity against Schistosoma japonicum

    Directory of Open Access Journals (Sweden)

    Jingyao Zhang

    2013-01-01

    Full Text Available Protein vaccines combined with adjuvants have been widely used to induce immune responses, especially the humoral immune response, against molecular targets including parasites. Follicular T helper (Tfh cells are the specialized providers of B-cell help, however, the induction of Tfh cells in protein vaccination has been rarely studied. Here, we report that the Schistosoma japonicum recombinant protein (SjGST-32 combined with tacrolimus (FK506 augmented the induction of Tfh cells, which expressed the canonical markers CXCR5, BCL6, and IL-21, and enhanced the humoral immune responses in BALB/c mice. Furthermore, the expression of IL-21R on germinal center (GC B cells and memory B cells increased in immunized mice, which indicated that IL-21 from the induced Tfh cells interacted with IL-21R for activation of B cells and maintenance of long-lived humoral immunity. Our results suggest that helminth protein vaccine combined with FK506 induces Tfh cell for stimulating humoral immune responses and inducing long-lived humoral immunity.

  19. Depletion of tyrosyl DNA phosphodiesterase 2 activity enhances etoposide-mediated double-strand break formation and cell killing.

    Science.gov (United States)

    Kont, Yasemin Saygideger; Dutta, Arijit; Mallisetty, Apurva; Mathew, Jeena; Minas, Tsion; Kraus, Christina; Dhopeshwarkar, Priyanka; Kallakury, Bhaskar; Mitra, Sankar; Üren, Aykut; Adhikari, Sanjay

    2016-07-01

    DNA topoisomerase 2 (Top2) poisons, including common anticancer drugs etoposide and doxorubicin kill cancer cells by stabilizing covalent Top2-tyrosyl-DNA 5'-phosphodiester adducts and DNA double-strand breaks (DSBs). Proteolytic degradation of the covalently attached Top2 leaves a 5'-tyrosylated blocked termini which is removed by tyrosyl DNA phosphodiesterase 2 (TDP2), prior to DSB repair through non-homologous end joining (NHEJ). Thus, TDP2 confers resistance of tumor cells to Top2-poisons by repairing such covalent DNA-protein adducts, and its pharmacological inhibition could enhance the efficacy of Top2-poisons. We discovered NSC111041, a selective inhibitor of TDP2, by optimizing a high throughput screening (HTS) assay for TDP2's 5'-tyrosyl phosphodiesterase activity and subsequent validation studies. We found that NSC111041 inhibits TDP2's binding to DNA without getting intercalated into DNA and enhanced etoposide's cytotoxicity synergistically in TDP2-expressing cells but not in TDP2 depleted cells. Furthermore, NSC111041 enhanced formation of etoposide-induced γ-H2AX foci presumably by affecting DSB repair. Immuno-histochemical analysis showed higher TDP2 expression in a sub-set of different type of tumor tissues. These findings underscore the feasibility of clinical use of suitable TDP2 inhibitors in adjuvant therapy with Top2-poisons for a sub-set of cancer patients with high TDP2 expression. PMID:27235629

  20. The inhibition of DNA synthesis in vitamin-E-depleted lymphosarcoma cells by X-rays and cytostatics

    International Nuclear Information System (INIS)

    Since there is evidence that the lipid-soluble anti-oxidant vitamin E may protect the polyunsaturated fatty acids of cellular membranes from free-radical attack, a shortage of vitamin E should increase the radiosensitivity of the membranes. An investigation has been carried out into the in vivo incorporation of 3H-thymidine in spleen lymphosarcomas growing in X-irradiated (500 rad) normal and vitamin-E-deficient C57BL mice. The results showed that DNA synthesis was significantly more radiosensitive in the vitamin-E-depleted lymphosarcoma cells, and that the effect was most pronounced 3 to 5 hours post irradiation. Studied of the effects of intraperitoneal injections of the cancer therapeutic agents 1-β-D-Arabinofuranosylcytosine (ARA-C) and Adriamycin on the inhibition of thymidine incorporation into DNA showed no significant differences between normal and vitamin-E deficient lymphosarcoma cells. The inhibition of DNA synthesis by these drugs does not involve free radicals. The vitamin E deficient tumour cells had a higher lipid peroxidation rate at 370C (0.5 +- 0.1 nmoles/mg protein per hour) than the normal cells (0.2 +- 0.1 nmoles/mg protein per hour). The higher lipid peroxidation capacity corresponded with the enhanced radiosensitivity. The results provide indirect evidence for the involvement of cellular membranes in the mechanism of radiation-induced inhibition of DNA synthesis. (U.K.)

  1. Behaviour of oleic acid-depleted bovine alpha-lactalbumin made LEthal to tumor cells (BAMLET).

    Science.gov (United States)

    Hoque, Mehboob; Gupta, Jyoti; Rabbani, Gulam; Khan, Rizwan Hasan; Saleemuddin, M

    2016-05-24

    Oleic acid (OA) complexes of human alpha-lactalbumin (α-LA) and several other proteins are effective in the killing of a variety of tumor cells. While debate on whether the key component of the complexes is the OA or protein continues, studies probing the mechanism of action of the complexes at the tumor cell surface or in the cell interior assume the action of a molecule in the form of an undissociated complex. Recent evidence however suggests that OA complexes of protein are stripped of bound OA on interaction with artificial or natural membranes before entering the cell. Properties of BAMLET stripped of its OA by exposure to erythrocytes (ET-BAMLET) were investigated in the study. ET-BAMLET resembled α-LA in its inability to induce hemolysis of erythrocytes and behaviour in a gel filtration column. Spectroscopy techniques-fluorescence, far- and near UV CD as well as calorimetry and proteolysis however suggest the molecule to be different both from native α-LA and the apo form. Remarkably, unlike native α-LA and apo-α-LA, ET-BAMLET binds OA and turns hemolytic by simple mixing with the fatty acid around neutral pH. Since BAMLET/HAMLET incubated cells take up large amounts of OA, the study suggests the possibility of ET-BAMLET combining with OA and reforming the complex inside the cells. PMID:27109252

  2. Contrasting Effects of Systemic Monocyte/Macrophage and CD4+ T Cell Depletion in a Reversible Ureteral Obstruction Mouse Model of Chronic Kidney Disease

    Directory of Open Access Journals (Sweden)

    Lee D. Chaves

    2013-01-01

    Full Text Available Using a reversible UUO model (rUUO, we have demonstrated that C57BL/6 mice are susceptible to development of CKD after obstruction-mediated kidney injury while BALB/c mice are resistant. We hypothesized that selective systemic depletion of subpopulations of inflammatory cells during injury or repair might alter the development of CKD. To investigate the impact of modification of Th-lymphocytes or macrophage responses on development of CKD after rUUO, we used an anti-CD4 antibody (GK1.5 or liposomal clodronate to systemically deplete CD4+ T cells or monocyte/macrophages, respectively, prior to and throughout the rUUO protocol. Flow cytometry and immunohistochemistry confirmed depletion of target cell populations. C57BL/6 mice treated with the GK1.5 antibody to deplete CD4+ T cells had higher BUN levels and delayed recovery from rUUO. Treatment of C57BL/6 mice with liposomal clodronate to deplete monocyte/macrophages led to a relative protection from CKD as assessed by BUN values. Our results demonstrate that modulation of the inflammatory response during injury and repair altered the susceptibility of C57BL/6 mice to development of CKD in our rUUO model.

  3. Analysis of cell-mediated immune responses in support of dengue vaccine development efforts.

    Science.gov (United States)

    Rothman, Alan L; Currier, Jeffrey R; Friberg, Heather L; Mathew, Anuja

    2015-12-10

    Dengue vaccine development has made significant strides, but a better understanding of how vaccine-induced immune responses correlate with vaccine efficacy can greatly accelerate development, testing, and deployment as well as ameliorate potential risks and safety concerns. Advances in basic immunology knowledge and techniques have already improved our understanding of cell-mediated immunity of natural dengue virus infection and vaccination. We conclude that the evidence base is adequate to argue for inclusion of assessments of cell-mediated immunity as part of clinical trials of dengue vaccines, although further research to identify useful correlates of protective immunity is needed.

  4. Immune Recognition of Latency-insitigating Pathogens by Human Dendritic Cells

    DEFF Research Database (Denmark)

    Søndergaard, Jonas Nørskov

    for society. Consequently there is a pressing need to search for new treatment strategies. Nowadays it is known that HIV-1 and Mtb have acquired the ability to escape the removal from the body by exploiting the immune system for their own benefits. Dendritic cells (DCs) determine the way the immune response...... that Mtb induces signaling in moDCs that misdirects the immune response into an extracellular Th17 response, even though the bacteria hide inside immune cells. Finally it is demonstrated how HIV-1 strains, capable of provoking sustained infection, induce a highmannose-independent complete necrotic...

  5. Mycolactone-Dependent Depletion of Endothelial Cell Thrombomodulin Is Strongly Associated with Fibrin Deposition in Buruli Ulcer Lesions.

    Directory of Open Access Journals (Sweden)

    Joy Ogbechi

    2015-07-01

    Full Text Available A well-known histopathological feature of diseased skin in Buruli ulcer (BU is coagulative necrosis caused by the Mycobacterium ulcerans macrolide exotoxin mycolactone. Since the underlying mechanism is not known, we have investigated the effect of mycolactone on endothelial cells, focussing on the expression of surface anticoagulant molecules involved in the protein C anticoagulant pathway. Congenital deficiencies in this natural anticoagulant pathway are known to induce thrombotic complications such as purpura fulimans and spontaneous necrosis. Mycolactone profoundly decreased thrombomodulin (TM expression on the surface of human dermal microvascular endothelial cells (HDMVEC at doses as low as 2 ng/ml and as early as 8 hrs after exposure. TM activates protein C by altering thrombin's substrate specificity, and exposure of HDMVEC to mycolactone for 24 hours resulted in an almost complete loss of the cells' ability to produce activated protein C. Loss of TM was shown to be due to a previously described mechanism involving mycolactone-dependent blockade of Sec61 translocation that results in proteasome-dependent degradation of newly synthesised ER-transiting proteins. Indeed, depletion from cells determined by live-cell imaging of cells stably expressing a recombinant TM-GFP fusion protein occurred at the known turnover rate. In order to determine the relevance of these findings to BU disease, immunohistochemistry of punch biopsies from 40 BU lesions (31 ulcers, nine plaques was performed. TM abundance was profoundly reduced in the subcutis of 78% of biopsies. Furthermore, it was confirmed that fibrin deposition is a common feature of BU lesions, particularly in the necrotic areas. These findings indicate that there is decreased ability to control thrombin generation in BU skin. Mycolactone's effects on normal endothelial cell function, including its ability to activate the protein C anticoagulant pathway are strongly associated with this

  6. Immunological Signatures after Bordetella pertussis Infection Demonstrate Importance of Pulmonary Innate Immune Cells

    Science.gov (United States)

    Brummelman, Jolanda; van der Maas, Larissa; Tilstra, Wichard; Pennings, Jeroen L. A.; Han, Wanda G. H.; van Els, Cécile A. C. M.; van Riet, Elly; Kersten, Gideon F. A.; Metz, Bernard

    2016-01-01

    Effective immunity against Bordetella pertussis is currently under discussion following the stacking evidence of pertussis resurgence in the vaccinated population. Natural immunity is more effective than vaccine-induced immunity indicating that knowledge on infection-induced responses may contribute to improve vaccination strategies. We applied a systems biology approach comprising microarray, flow cytometry and multiplex immunoassays to unravel the molecular and cellular signatures in unprotected mice and protected mice with infection-induced immunity, around a B. pertussis challenge. Pre-existing systemic memory Th1/Th17 cells, memory B-cells, and mucosal IgA specific for Ptx, Vag8, Fim2/3 were detected in the protected mice 56 days after an experimental infection. In addition, pre-existing high activity and reactivation of pulmonary innate cells such as alveolar macrophages, M-cells and goblet cells was detected. The pro-inflammatory responses in the lungs and serum, and neutrophil recruitment in the spleen upon an infectious challenge of unprotected mice were absent in protected mice. Instead, fast pulmonary immune responses in protected mice led to efficient bacterial clearance and harbored potential new gene markers that contribute to immunity against B. pertussis. These responses comprised of innate makers, such as Clca3, Retlna, Glycam1, Gp2, and Umod, next to adaptive markers, such as CCR6+ B-cells, CCR6+ Th17 cells and CXCR6+ T-cells as demonstrated by transcriptome analysis. In conclusion, besides effective Th1/Th17 and mucosal IgA responses, the primary infection-induced immunity benefits from activation of pulmonary resident innate immune cells, achieved by local pathogen-recognition. These molecular signatures of primary infection-induced immunity provided potential markers to improve vaccine-induced immunity against B. pertussis. PMID:27711188

  7. Biochemical and Functional Insights into the Integrated Regulation of Innate Immune Cell Responses by Teleost Leukocyte Immune-Type Receptors

    Directory of Open Access Journals (Sweden)

    Chenjie Fei

    2016-03-01

    Full Text Available Across vertebrates, innate immunity consists of a complex assortment of highly specialized cells capable of unleashing potent effector responses designed to destroy or mitigate foreign pathogens. The execution of various innate cellular behaviors such as phagocytosis, degranulation, or cell-mediated cytotoxicity are functionally indistinguishable when being performed by immune cells isolated from humans or teleost fishes; vertebrates that diverged from one another more than 450 million years ago. This suggests that vital components of the vertebrate innate defense machinery are conserved and investigating such processes in a range of model systems provides an important opportunity to identify fundamental features of vertebrate immunity. One characteristic that is highly conserved across vertebrate systems is that cellular immune responses are dependent on specialized immunoregulatory receptors that sense environmental stimuli and initiate intracellular cascades that can elicit appropriate effector responses. A wide variety of immunoregulatory receptor families have been extensively studied in mammals, and many have been identified as cell- and function-specific regulators of a range of innate responses. Although much less is known in fish, the growing database of genomic information has recently allowed for the identification of several immunoregulatory receptor gene families in teleosts. Many of these putative immunoregulatory receptors have yet to be assigned any specific role(s, and much of what is known has been based solely on structural and/or phylogenetic relationships with mammalian receptor families. As an attempt to address some of these shortcomings, this review will focus on our growing understanding of the functional roles played by specific members of the channel catfish (Ictalurus punctatus leukocyte immune-type receptors (IpLITRs, which appear to be important regulators of several innate cellular responses via classical as well

  8. Establishment of Stable, Cell-Mediated Immunity that Makes "Susceptible" Mice Resistant to Leishmania major

    Science.gov (United States)

    Bretscher, Peter A.; Wei, Guojian; Menon, Juthika N.; Bielefeldt-Ohmann, Helle

    1992-07-01

    Cell-mediated, but not antibody-mediated, immune responses protect humans against certain pathogens that produce chronic diseases such as leishmaniasis. Effective vaccination against such pathogens must therefore produce an immunological "imprint" so that stable, cell-mediated immunity is induced in all individuals after natural infection. BALB/c mice "innately susceptible" to Leishmania major produce antibodies after substantial infection. In the present study, "susceptible" mice injected with a small number of parasites mounted a cell-mediated response and acquired resistance to a larger, normally pathogenic, challenge. This vaccination strategy may be applicable in diseases in which protection is dependent on cell-mediated immunity.

  9. Depletion kinetics of circulating prostate cancer cells studied by in vivo flow cytometer

    Science.gov (United States)

    Liu, Guangda; Guo, Jin; Li, Yan; Chen, Yun; Gu, Zhengqin; Chen, Tong; Wang, Cheng; Wei, Xunbin

    2010-11-01

    Prostate cancer is the most common malignancy in American men and the second leading cause of deaths from cancer, after lung cancer. The tumor usually grows slowly and remains confined to the gland for many years. During this time, the tumor produces little or no symptoms or outward signs. As the cancer advances, however, it can metastasize throughout other areas of the body, such as the bones, lungs, and liver. Surgical resection, hormonal therapy, chemotherapy and radiation therapy are the foundation of current prostate cancer therapies. Treatments for prostate cause both short- and long-term side effects that may be difficult to accept. Molecular mechanisms of prostate cancer metastasis need to be understood better and new therapies must be developed to selectively target to unique characteristics of cancer cell growth and metastasis. We have developed the "in vivo microscopy" to study the mechanisms that govern prostate cancer cell spread through the microenvironment in vivo in real-time confocal nearinfrared fluorescence imaging. A recently developed "in vivo flow cytometer" and optical imaging are used to assess prostate cancer cell spreading and the circulation kinetics of prostate cancer cells. A real- time quantitative monitoring of circulating prostate cancer cells by the in vivo flow cytometer will be useful to assess the effectiveness of the potential therapeutic interventions.

  10. Studying depletion kinetics of circulating prostate cancer cells by in vivo flow cytometer

    Science.gov (United States)

    Liu, Guangda; Gu, Zhengqin; Guo, Jin; Li, Yan; Chen, Yun; Chen, Tong; Wang, Cheng; Wei, Xunbin

    2011-03-01

    Prostate cancer is the most common malignancy in American men and the second leading cause of deaths from cancer, after lung cancer. The tumor usually grows slowly and remains confined to the gland for many years. During this time, the tumor produces little or no symptoms or outward signs. As the cancer advances, however, it can metastasize throughout other areas of the body, such as the bones, lungs, and liver. Surgical resection, hormonal therapy, chemotherapy and radiation therapy are the foundation of current prostate cancer therapies. Treatments for prostate cause both short- and long-term side effects that may be difficult to accept. Molecular mechanisms of prostate cancer metastasis need to be understood better and new therapies must be developed to selectively target to unique characteristics of cancer cell growth and metastasis. We have developed the "in vivo microscopy" to study the mechanisms that govern prostate cancer cell spread through the microenvironment in vivo in real-time confocal near-infrared fluorescence imaging. A recently developed "in vivo flow cytometer" and optical imaging are used to assess prostate cancer cell spreading and the circulation kinetics of prostate cancer cells. A real- time quantitative monitoring of circulating prostate cancer cells by the in vivo flow cytometer will be useful to assess the effectiveness of the potential therapeutic interventions.

  11. Intracellular Glutathione Depletion by Oridonin Leads to Apoptosis in Hepatic Stellate Cells

    Directory of Open Access Journals (Sweden)

    Liang-Mou Kuo

    2014-03-01

    Full Text Available Proliferation of hepatic stellate cells (HSCs plays a key role in the pathogenesis of liver fibrosis. Induction of HSC apoptosis by natural products is considered an effective strategy for treating liver fibrosis. Herein, the apoptotic effects of 7,20-epoxy-ent-kaurane (oridonin, a diterpenoid isolated from Rabdosia rubescens, and its underlying mechanisms were investigated in rat HSC cell line, HSC-T6. We found that oridonin inhibited cell viability of HSC-T6 in a concentration-dependent manner. Oridonin induced a reduction in mitochondrial membrane potential and increases in caspase 3 activation, subG1 phase, and DNA fragmentation. These apoptotic effects of oridonin were completely reversed by thiol antioxidants, N-acetylcysteine (NAC and glutathione monoethyl ester. Moreover, oridonin increased production of reactive oxygen species (ROS, which was also inhibited by NAC. Significantly, oridonin reduced intracellular glutathione (GSH level in a concentration- and time-dependent fashion. Additionally, oridonin induced phosphorylations of extracellular signal-regulated kinase (ERK, c-Jun N-terminal kinase (JNK, and p38 mitogen-activated protein kinase (MAPK. NAC prevented the activation of MAPKs in oridonin-induced cells. However, selective inhibitors of MAPKs failed to alter oridonin-induced cell death. In summary, these results demonstrate that induction of apoptosis in HSC-T6 by oridonin is associated with a decrease in cellular GSH level and increase in ROS production.

  12. Specific cytotoxic T-cell immune responses against autoantigens recognized by chronic lymphocytic leukaemia cells.

    Science.gov (United States)

    Zaleska, Joanna; Skorka, Katarzyna; Zajac, Malgorzata; Karczmarczyk, Agnieszka; Karp, Marta; Tomczak, Waldemar; Hus, Marek; Wlasiuk, Paulina; Giannopoulos, Krzysztof

    2016-08-01

    Mounting evidence suggests that autoreactivity and inflammatory processes are involved in the pathogenesis of chronic lymphocytic leukaemia (CLL). Cytoskeletal proteins, including non-muscle myosin heavy chain IIA (MYHIIA), vimentin (VIM) and cofilin-1 (CFL1), exposed on the surface of apoptotic cells have been identified as autoantigens that are recognized by the specific B-cell receptors of the CLL cells. In 212 CLL patients analysed with quantitative reverse transcriptase-polymerase chain reaction we found CFL1 overexpression and low expression of MYH9 in comparison with healthy volunteers. We detected specific cytotoxic immune responses for peptides derived from MYHIIA in 66·7%, VIM in 87·5% and CFL1 in 62·5% CLL patients in an Enzyme-Linked ImmunoSpot assay. Low frequencies of autoreactive peptide-specific T cells were detected against MYHIIA, VIM and CFL1 in CLL patients ex vivo; most of the detected cells had an effector-memory phenotype. Our findings support the existence of cytotoxic immune responses against three autoantigens that have been identified as targets of CLL clonotypic B-cell receptors. The presence of autoreactive CD8(+) T cells against MYHIIA, VIM and CFL1 in CLL patients indicates the involvement of antigen-specific autoreactive T cells in the pathogenesis of CLL.

  13. Targeted impairment of thymidine kinase 2 expression in cells induces mitochondrial DNA depletion and reveals molecular mechanisms of compensation of mitochondrial respiratory activity

    Energy Technology Data Exchange (ETDEWEB)

    Villarroya, Joan, E-mail: joanvillarroya@gmail.com [Institut de Recerca, Hospital Universitari de la Vall d' Hebron, Barcelona (Spain); Institut de Recerca l' Hospital de la Santa Creu i Sant Pau, Barcelona (Spain); Lara, Mari-Carmen [Institut de Recerca, Hospital Universitari de la Vall d' Hebron, Barcelona (Spain); Department of Neurology, Columbia University Medical Center, New York, NY (United States); Centro de Investigacion Biomedica en Red de Enfermedades Raras (CIBERER), ISCIII (Spain); Dorado, Beatriz [Department of Neurology, Columbia University Medical Center, New York, NY (United States); Garrido, Marta [Unitat de Biologia Cel.lular i Molecular, IMIM-Hospital del Mar, Barcelona (Spain); Garcia-Arumi, Elena [Institut de Recerca, Hospital Universitari de la Vall d' Hebron, Barcelona (Spain); Centro de Investigacion Biomedica en Red de Enfermedades Raras (CIBERER), ISCIII (Spain); Meseguer, Anna [Institut de Recerca, Hospital Universitari de la Vall d' Hebron, Barcelona (Spain); Hirano, Michio [Department of Neurology, Columbia University Medical Center, New York, NY (United States); Vila, Maya R. [Institut de Recerca, Hospital Universitari de la Vall d' Hebron, Barcelona (Spain)

    2011-04-08

    Highlights: {yields} We impaired TK2 expression in Ost TK1{sup -} cells via siRNA-mediated interference (TK2{sup -}). {yields} TK2 impairment caused severe mitochondrial DNA (mtDNA) depletion in quiescent cells. {yields} Despite mtDNA depletion, TK2{sup -} cells show high cytochrome oxidase activity. {yields} Depletion of mtDNA occurs without imbalance in the mitochondrial dNTP pool. {yields} Nuclear-encoded ENT1, DNA-pol {gamma}, TFAM and TP gene expression is lowered in TK2{sup -} cells. -- Abstract: The mitochondrial DNA (mtDNA) depletion syndrome comprises a clinically heterogeneous group of diseases characterized by reductions of the mtDNA abundance, without associated point mutations or rearrangements. We have developed the first in vitro model to study of mtDNA depletion due to reduced mitochondrial thymidine kinase 2 gene (TK2) expression in order to understand the molecular mechanisms involved in mtDNA depletion syndrome due to TK2 mutations. Small interfering RNA targeting TK2 mRNA was used to decrease TK2 expression in Ost TK1{sup -} cells, a cell line devoid of endogenous thymidine kinase 1 (TK1). Stable TK2-deficient cell lines showed a reduction of TK2 levels close to 80%. In quiescent conditions, TK2-deficient cells showed severe mtDNA depletion, also close to 80% the control levels. However, TK2-deficient clones showed increased cytochrome c oxidase activity, higher cytochrome c oxidase subunit I transcript levels and higher subunit II protein expression respect to control cells. No alterations of the deoxynucleotide pools were found, whereas a reduction in the expression of genes involved in nucleoside/nucleotide homeostasis (human equilibrative nucleoside transporter 1, thymidine phosphorylase) and mtDNA maintenance (DNA-polymerase {gamma}, mitochondrial transcription factor A) was observed. Our findings highlight the importance of cellular compensatory mechanisms that enhance the expression of respiratory components to ensure respiratory activity

  14. Label-free haemogram using wavelength modulated Raman spectroscopy for identifying immune-cell subset

    Science.gov (United States)

    Ashok, Praveen C.; Praveen, Bavishna B.; Campbell, Elaine C.; Dholakia, Kishan; Powis, Simon J.

    2014-03-01

    Leucocytes in the blood of mammals form a powerful protective system against a wide range of dangerous pathogens. There are several types of immune cells that has specific role in the whole immune system. The number and type of immune cells alter in the disease state and identifying the type of immune cell provides information about a person's state of health. There are several immune cell subsets that are essentially morphologically identical and require external labeling to enable discrimination. Here we demonstrate the feasibility of using Wavelength Modulated Raman Spectroscopy (WMRS) with suitable machine learning algorithms as a label-free method to distinguish between different closely lying immune cell subset. Principal Component Analysis (PCA) was performed on WMRS data from single cells, obtained using confocal Raman microscopy for feature reduction, followed by Support Vector Machine (SVM) for binary discrimination of various cell subset, which yielded an accuracy >85%. The method was successful in discriminating between untouched and unfixed purified populations of CD4+CD3+ and CD8+CD3+ T lymphocyte subsets, and CD56+CD3- natural killer cells with a high degree of specificity. It was also proved sensitive enough to identify unique Raman signatures that allow clear discrimination between dendritic cell subsets, comprising CD303+CD45+ plasmacytoid and CD1c+CD141+ myeloid dendritic cells. The results of this study clearly show that WMRS is highly sensitive and can distinguish between cell types that are morphologically identical.

  15. B-Cell Depletion Therapy in Systemic Sclerosis: Experimental Rationale and Update on Clinical Evidence

    Directory of Open Access Journals (Sweden)

    Dimitrios Daoussis

    2011-01-01

    Full Text Available Systemic sclerosis (SSc is a systemic rheumatic disease with poor prognosis since therapeutic options are limited. Recent evidence from animal models suggests that B-cells may be actively involved in the fibrotic process. B-cells from tight skin mice, an animal model of scleroderma, display a “hyperresponsive” phenotype; treatment with rituximab (RTX significantly attenuates skin fibrosis in this animal model. In humans, B-cell infiltration is a prominent finding in most lung biopsies obtained from patients with SSc-associated interstitial lung disease. Several open label studies have assessed the clinical efficacy of RTX in SSc. In most patients skin fibrosis improved; lung function either improved or remained stable. Definite conclusions regarding the clinical efficacy of RTX in SSc cannot be drawn but further exploration with a multicenter, randomized study is warranted.

  16. Depletion of pre-16S rRNA in starved Escherichia coli cells.

    OpenAIRE

    Cangelosi, G A; Brabant, W H

    1997-01-01

    Specific hybridization assays for intermediates in rRNA synthesis (pre-rRNA) may become useful for monitoring the growth activity of individual microbial species in complex natural systems. This possibility depends upon the assumption that rRNA processing in microbial cells continues after growth and pre-rRNA synthesis cease, resulting in drainage of the pre-rRNA pool. This is not the case in many eukaryotic cells, but less is known about the situation in bacteria. Therefore, we used DNA prob...

  17. Age-related declines in immune response in a wild mammal are unrelated to immune cell telomere length.

    Science.gov (United States)

    Beirne, Christopher; Waring, Laura; McDonald, Robbie A; Delahay, Richard; Young, Andrew

    2016-02-24

    Senescence has been hypothesized to arise in part from age-related declines in immune performance, but the patterns and drivers of within-individual age-related changes in immunity remain virtually unexplored in natural populations. Here, using a long-term epidemiological study of wild European badgers (Meles meles), we (i) present evidence of a within-individual age-related decline in the response of a key immune-signalling cytokine, interferon-gamma (IFNγ), to ex vivo lymphocyte stimulation, and (ii) investigate three putative drivers of individual variation in the rate of this decline (sex, disease and immune cell telomere length; ICTL). That the within-individual rate of age-related decline markedly exceeded that at the population level suggests that individuals with weaker IFNγ responses are selectively lost from this population. IFNγ responses appeared to decrease with the progression of bovine tuberculosis infection (independent of age) and were weaker among males than females. However, neither sex nor disease influenced the rate of age-related decline in IFNγ response. Similarly, while ICTL also declines with age, variation in ICTL predicted neither among- nor within-individual variation in IFNγ response. Our findings provide evidence of within-individual age-related declines in immune performance in a wild mammal and highlight the likely complexity of the mechanisms that generate them. PMID:26888036

  18. Steroid hormone signaling is essential to regulate innate immune cells and fight bacterial infection in Drosophila.

    Directory of Open Access Journals (Sweden)

    Jennifer C Regan

    2013-10-01

    Full Text Available Coupling immunity and development is essential to ensure survival despite changing internal conditions in the organism. Drosophila metamorphosis represents a striking example of drastic and systemic physiological changes that need to be integrated with the innate immune system. However, nothing is known about the mechanisms that coordinate development and immune cell activity in the transition from larva to adult. Here, we reveal that regulation of macrophage-like cells (hemocytes by the steroid hormone ecdysone is essential for an effective innate immune response over metamorphosis. Although it is generally accepted that steroid hormones impact immunity in mammals, their action on monocytes (e.g. macrophages and neutrophils is still not well understood. Here in a simpler model system, we used an approach that allows in vivo, cell autonomous analysis of hormonal regulation of innate immune cells, by combining genetic manipulation with flow cytometry, high-resolution time-lapse imaging and tissue-specific transcriptomic analysis. We show that in response to ecdysone, hemocytes rapidly upregulate actin dynamics, motility and phagocytosis of apoptotic corpses, and acquire the ability to chemotax to damaged epithelia. Most importantly, individuals lacking ecdysone-activated hemocytes are defective in bacterial phagocytosis and are fatally susceptible to infection by bacteria ingested at larval stages, despite the normal systemic and local production of antimicrobial peptides. This decrease in survival is comparable to the one observed in pupae lacking immune cells altogether, indicating that ecdysone-regulation is essential for hemocyte immune functions and survival after infection. Microarray analysis of hemocytes revealed a large set of genes regulated at metamorphosis by EcR signaling, among which many are known to function in cell motility, cell shape or phagocytosis. This study demonstrates an important role for steroid hormone regulation of

  19. Transcriptional modulation in a leukocyte-depleted splenic cell population during prion disease.

    Science.gov (United States)

    Huzarewich, Rhiannon L C H; Medina, Sarah; Robertson, Catherine; Parchaliuk, Debra; Booth, Stephanie A

    2011-01-01

    Prion replication in the periphery precedes neuroinvasion in many experimental rodent scrapie models, and in natural sheep scrapie and chronic wasting disease (CWD) in cervids. Prions propagate in the germinal centers of secondary lymphoid organs and are strongly associated with follicular dendritic cells (FDC) and possibly circulating dendritic cells and macrophages. Given the importance of lymphoid organs in prion disease transmission and pathogenesis, gene expression studies may reveal host factors or biological pathways related to prion replication and accumulation. A procedure was developed to enrich for FDC, dendritic cells, and macrophages prior to the investigation of transcriptional alterations in murine splenic cells during prion pathogenesis. In total, 1753 transcripts exhibited fold changes greater than three (false discovery rates less than 2%) in this population isolated from spleens of prion-infected versus uninfected mice. The gene for the small leucine-rich proteoglycan decorin (DCN) was one of the genes most overexpressed in infected mice, and the splenic protein levels mirrored this in mice infected with scrapie as well as bovine spongiform encephalopathy (BSE) and variant Creutzfeldt-Jakob disease (vCJD). A number of groups of functionally related genes were also significantly decreased in infected spleens. These included genes related to iron metabolism and homeostasis, pathways that have also been implicated in prion pathogenesis in the brain. These gene expression alterations provide insights into the molecular mechanisms underlying prion disease pathogenesis and may serve as a pool of potential surrogate markers for the early detection and diagnosis of some prion diseases. PMID:22043911

  20. T cell immunity in the teleost digestive tract.

    Science.gov (United States)

    Tafalla, Carolina; Leal, Esther; Yamaguchi, Takuya; Fischer, Uwe

    2016-11-01

    Fish (along with cyclostomes) constitute the most ancient animal group in which an acquired immune system is present. As in higher vertebrates, both B and T lymphocytes cooperate in implementing an adequate response. Although there is still a debate on whether fish possess a true gut associated lymphoid tissue (GALT), the presence of diffuse B and T lymphocytes throughout all mucosal surfaces has been demonstrated in a wide variety of fish species. The lack of antibodies against T lymphocyte markers has hampered the performance of functional assays in both systemic and mucosal compartments. However, most components associated with T lymphocyte function have been identified in fish through extensive genomic research, suggesting similar functionalities for fish and mammalian T lymphocytes. Thus, the aim of this review is to briefly summarize what is known in teleost concerning the characteristics and functionalities of the different T cell subsets, to then focus on what is known to date regarding their presence and role in the gastrointestinal tract, through either direct functional assays or indirectly by conclusions drawn from transcriptomic analysis. PMID:26905634

  1. Hypoxia-induced soluble CD137 in malignant cells blocks CD137L-costimulation as an immune escape mechanism

    Science.gov (United States)

    Labiano, Sara; Palazón, Asis; Bolaños, Elixabet; Azpilikueta, Arantza; Sánchez-Paulete, Alfonso R.; Morales-Kastresana, Aizea; Quetglas, Jose I.; Perez-Gracia, José L.; Gúrpide, Alfonso; Rodriguez-Ruiz, Maria; Aznar, M. Angela; Jure-Kunkel, Maria; Berraondo, Pedro; Melero, Ignacio

    2016-01-01

    ABSTRACT Hypoxia is a common feature in solid tumors that has been implicated in immune evasion. Previous studies from our group have shown that hypoxia upregulates the co-stimulatory receptor CD137 on activated T lymphocytes and on vascular endothelial cells. In this study, we show that exposure of mouse and human tumor cell lines to hypoxic conditions (1% O2) promotes CD137 transcription. However, the resulting mRNA is predominantly an alternatively spliced form that encodes for a soluble variant, lacking the transmembrane domain. Accordingly, soluble CD137 (sCD137) is detectable by ELISA in the supernatant of hypoxia-exposed cell lines and in the serum of tumor-bearing mice. sCD137, as secreted by tumor cells, is able to bind to CD137-Ligand (CD137L). Our studies on primed T lymphocytes in co-culture with stable transfectants for CD137L demonstrate that tumor-secreted sCD137 prevents co-stimulation of T lymphocytes. Such an effect results from preventing the interaction of CD137L with the transmembrane forms of CD137 expressed on T lymphocytes undergoing activation. Indeed, silencing CD137 with shRNA renders more immunogenic tumor-cell variants upon inoculation to immunocompetent mice but which readily grafted on immunodeficient or CD8+ T-cell-depleted mice. These mechanisms are interpreted as a molecular strategy deployed by tumors to repress lymphocyte co-stimulation via CD137/CD137L. PMID:26942078

  2. How numbers, nature and immune status of Foxp3+ regulatory T cells shape the early immunological events in tumor development.

    Directory of Open Access Journals (Sweden)

    Guillaume eDarrasse-Jeze

    2013-09-01

    Full Text Available The influence of CD4+CD25+Foxp3+ regulatory T cells (Tregs on cancer progression has been demonstrated in a large number of preclinical models and confirmed in several types of malignancies. Neoplastic processes trigger an increase of Treg numbers in draining lymph nodes, spleen, blood, and tumors, leading to the suppression of anti-tumor responses. Treg depletion before or early in tumor development may lead to complete tumor eradication and extends survival of mice and humans. However this strategy is ineffective in established tumors, highlighting the critical role of the early Treg-tumor encounters. In this review, after discussing old and new concepts of immunological tumor tolerance, we focus on the nature (thymus-derived vs. peripherally-derived and status (naïve or activated / memory of the regulatory T cells at tumor emergence. The recent discoveries in this field suggest that the activation status of Tregs and effector T cells (Teffs at the first encounter with the tumor are essential to shape the fate and speed of the immune response across a variety of tumor models. The relative timing of activation/recruitment of antitumor cells versus tolerogenic cells at tumor emergence appears to be crucial in the identification of tumor cells as friend or foe, which has broad implications for the design of cancer immunotherapies.

  3. A role for CD4 sup + but not CD8 sup + T cells in immunity to Schistosoma mansoni induced by 20 krad-irradiated and Ro 11-3128-terminated infections

    Energy Technology Data Exchange (ETDEWEB)

    Vignali, D.A.A.; Bickle, Q.D.; Taylor, M.G. (London School of Hygiene and Tropical Medicine (UK)); Crocker, P. (Oxford Univ. (UK). Sir William Dunn School of Pathology); Cobbold, S.; Waldmann, H (Cambridge Univ. (UK). Dept. of Pathology)

    1989-08-01

    The role of CD4{sup +} (L3/T4{sup +}) and CD8{sup +} (Lyt-2{sup +}) T cells in immunity to Schistosoma mansoni induced by 20 krad-irradiated and Ro 11-terminated infections in mice was investigated directly by in vivo depletion of these subsets with cytotoxic rat monoclonal antibodies (mAb). Effective physical depletion was demonstrated by flow cytometric analysis and immunohistochemical staining. Functional depletion of helper activity following anti-CD4 treatment was indicated by an abrogation of concanavalin A(Con A)-induced colony-stimulating factor (CSF) release, while anti-CD8 treatment had no effect in these assays. Pre-existing S. mansoni-specific antibody levels were unaffected by anti-CD4 and anti-CD8 treatment. In vivo depletion of CD4 {sup +} T cells resulted in a dramatic reduction in immunity induced by one (up to 100%) and two (up to 70%) vaccinations with 20 krad-irradiated cercariae and also of resistance induced by Ro 11-attenuated infections (up to 100%). Depletion of CD8{sup +} T cells had no effect on resistance induced by any of the vaccination protocols investigated. A correlation was observed between resistance and T cell-induced, macrophage-mediated killing of schistosomula in vitro, both of which were abrogated following anti-CD4 treatment but were unaffected by CD8{sup +} T-cell depletion. The possible role of CD4{sup +} T cells in vivo and the implications for vaccine development are discussed. (author).

  4. Immune Cell Dynamics in the CNS : Learning From the Zebrafish

    NARCIS (Netherlands)

    Oosterhof, Nynke; Boddeke, Erik; van Ham, Tjakko J.

    2015-01-01

    A major question in research on immune responses in the brain is how the timing and nature of these responses influence physiology, pathogenesis or recovery from pathogenic processes. Proper understanding of the immune regulation of the human brain requires a detailed description of the function and

  5. Allogeneic Transplantation of Müller-Derived Retinal Ganglion Cells Improves Retinal Function in a Feline Model of Ganglion Cell Depletion.

    Science.gov (United States)

    Becker, Silke; Eastlake, Karen; Jayaram, Hari; Jones, Megan F; Brown, Robert A; McLellan, Gillian J; Charteris, David G; Khaw, Peng T; Limb, G Astrid

    2016-02-01

    Human Müller glia with stem cell characteristics (hMGSCs) have been shown to improve retinal function upon transplantation into rat models of retinal ganglion cell (RGC) depletion. However, their translational potential may depend upon successful engraftment and improvement of retinal function in experimental models with anatomical and functional features resembling those of the human eye. We investigated the effect of allogeneic transplantation of feline Müller glia with the ability to differentiate into cells expressing RGC markers, following ablation of RGCs by N-methyl-d-aspartate (NMDA). Unlike previous observations in the rat, transplantation of hMGSC-derived RGCs into the feline vitreous formed aggregates and elicited a severe inflammatory response without improving visual function. In contrast, allogeneic transplantation of feline MGSC (fMGSC)-derived RGCs into the vitrectomized eye improved the scotopic threshold response (STR) of the electroretinogram (ERG). Despite causing functional improvement, the cells did not attach onto the retina and formed aggregates on peripheral vitreous remnants, suggesting that vitreous may constitute a barrier for cell attachment onto the retina. This was confirmed by observations that cellular scaffolds of compressed collagen and enriched preparations of fMGSC-derived RGCs facilitated cell attachment. Although cells did not migrate into the RGC layer or the optic nerve, they significantly improved the STR and the photopic negative response of the ERG, indicative of increased RGC function. These results suggest that MGSCs have a neuroprotective ability that promotes partial recovery of impaired RGC function and indicate that cell attachment onto the retina may be necessary for transplanted cells to confer neuroprotection to the retina. Significance: Müller glia with stem cell characteristics are present in the adult human retina, but they do not have regenerative ability. These cells, however, have potential for

  6. Age-Dependent Differences in Systemic and Cell-Autonomous Immunity to L. monocytogenes

    Directory of Open Access Journals (Sweden)

    Ashley M. Sherrid

    2013-01-01

    Full Text Available Host defense against infection can broadly be categorized into systemic immunity and cell-autonomous immunity. Systemic immunity is crucial for all multicellular organisms, increasing in importance with increasing cellular complexity of the host. The systemic immune response to Listeria monocytogenes has been studied extensively in murine models; however, the clinical applicability of these findings to the human newborn remains incompletely understood. Furthermore, the ability to control infection at the level of an individual cell, known as “cell-autonomous immunity,” appears most relevant following infection with L. monocytogenes; as the main target, the monocyte is centrally important to innate as well as adaptive systemic immunity to listeriosis. We thus suggest that the overall increased risk to suffer and die from L. monocytogenes infection in the newborn period is a direct consequence of age-dependent differences in cell-autonomous immunity of the monocyte to L. monocytogenes. We here review what is known about age-dependent differences in systemic innate and adaptive as well as cell-autonomous immunity to infection with Listeria monocytogenes.

  7. Wash functions downstream of Rho1 GTPase in a subset of Drosophila immune cell developmental migrations

    OpenAIRE

    Verboon, Jeffrey M; Travis K Rahe; Rodriguez-Mesa, Evelyn; Parkhurst, Susan M.

    2015-01-01

    Drosophila immune cells, the hemocytes, undergo four stereotypical developmental migrations to populate the embryo, where they provide immune reconnoitering, as well as a number of non–immune-related functions necessary for proper embryogenesis. Here, we describe a role for Rho1 in one of these developmental migrations in which posteriorly located hemocytes migrate toward the head. This migration requires the interaction of Rho1 with its downstream effector Wash, a Wiskott–Aldrich syndrome fa...

  8. Immunotoxicological impact of engineered nanomaterial exposure: mechanisms of immune cell modulation

    OpenAIRE

    WANG, XIAOJIA; Reece, Shaun P.; Brown, Jared M.

    2013-01-01

    Engineered nanomaterials (ENM) are increasingly being utilized in many consumer products and various medical applications thereby leading to the potentiality of increased human exposures. Assessment of the adverse effects on the immune system is an important component for evaluating the overall health and safety of ENM. Tasked with eliminating pathogens and removing cancerous cells, the immune system is constantly functioning to maintain homeostasis. Small modifications to the immune system w...

  9. The case of the “serfdom” condition of phagocytic immune cells

    Directory of Open Access Journals (Sweden)

    E Ottaviani

    2012-08-01

    Full Text Available In a modern immunological perspective, it may be asserted that the phagocytic cell should not be considered as the "serfdom", but rather the pivot of the immune system. Indeed, the invertebrate immunocyte as well as the vertebrate macrophage play a central role in immunity, inflammation and stress response. The evolutionary conserved immune-neuroendocrine effector system have remained of fundamental importance in defense against pathogens, and its efficiency increased through synergy with the new, clonotipical recognition repertoire in vertebrates.

  10. Shrinkage insensitivity of NKCC1 in myosin II-depleted cytoplasts from Ehrlich ascites tumor cells

    DEFF Research Database (Denmark)

    Hoffmann, Else K; Pedersen, Stine F

    2007-01-01

    Protein phosphorylation/dephosphorylation and cytoskeletal reorganization regulate the Na(+)-K(+)-2Cl(-) cotransporter (NKCC1) during osmotic shrinkage; however, the mechanisms involved are unclear. We show that in cytoplasts, plasma membrane vesicles detached from Ehrlich ascites tumor cells (EATC......) by cytochalasin treatment, NKCC1 activity evaluated as bumetanide-sensitive (86)Rb influx was increased compared with the basal level in intact cells yet could not be further increased by osmotic shrinkage. Accordingly, cytoplasts exhibited no regulatory volume increase after shrinkage. In cytoplasts......, cortical F-actin organization was disrupted, and myosin II, which in shrunken EATC translocates to the cortical region, was absent. Moreover, NKCC1 activity was essentially insensitive to the myosin light chain kinase (MLCK) inhibitor ML-7, a potent blocker of shrinkage-induced NKCC1 activity in intact...

  11. The role of IL-33/ST2L signals in the immune cells.

    Science.gov (United States)

    Lu, Jingli; Kang, Jian; Zhang, Chengliang; Zhang, Xiaojian

    2015-03-01

    Interleukin (IL)-33 signals influence various immune cells during differentiation, immune responses and homeostasis. As discussed in this Review, IL-33 via TI/ST2L regulates the functions of immune cells including T cells, B cells, DCs, macrophages, mast cells, and innate lymphoid cells (ILCs). Stimulation with IL-33 is crucial for CD4+ T cell polarized into Th2 immunity and for the induction of Treg. CD8+ T cells can also express ST2L and IL-33 promotes features of effector CD8+ T cells. For macrophages and ILCs, ST2L presents on these cells and IL-33 induces Th2 cytokine production. IL-33 modulates adhesion, activation, maturation, and cytokine production by mast cells. ST2 is expressed in B1 and is important for differentiation of IL-10-producing B cells. Understanding the specific role of IL-33/ST2L in different immune cells will help to answer the remaining questions that are important for diseases pathologies and intervention strategies by targeting the IL-33/ST2L signals. PMID:25662624

  12. Hepatitis C Virus Immune Escape via Exploitation of a Hole in the T cell Repertoire

    OpenAIRE

    Wolfl, Matthias; Rutebemberwa, Alleluiah; Mosbruger, Timothy; Mao, Qing; Li, Hongmei; Netski, Dale; Ray, Stuart C.; Pardoll, Drew; Sidney, John; Sette, Alessandro; Allen, Todd; Kuntzen, Thomas; Kavanagh, Daniel G.; Kuball, Jurgen; Greenberg, Philip D.

    2008-01-01

    Hepatitis C virus (HCV) infection frequently persists despite eliciting substantial virus-specific immune responses. Thus, HCV infection provides a setting in which to investigate mechanisms of immune escape that allow for viral persistence. Viral amino acid substitutions resulting in decreased MHC binding or impaired antigen processing of T cell epitopes reduce antigen density on the cell surface, permitting evasion of T cell responses in chronic viral infection. Substitutions in viral epito...

  13. Cancer stem cell immunology: key to understanding tumorigenesis and tumor immune escape?

    OpenAIRE

    Valentin eBruttel; Jörg eWischhusen

    2014-01-01

    Cancer stem cell (CSC) biology and tumor immunology have shaped our understanding of tumorigenesis. However, we still do not fully understand why tumors can be contained but not eliminated by the immune system and whether rare CSCs are required for tumor propagation.Long latency or recurrence periods have been described for most tumors. Conceptually, this requires a subset of malignant cells which is capable of initiating tumors, but is neither eliminated by immune cells nor able to grow stra...

  14. Mesenchymal Stem Cells in Immune-Mediated Bone Marrow Failure Syndromes

    OpenAIRE

    Maria-Christina Kastrinaki; Konstantia Pavlaki; Batsali, Aristea K.; Elisavet Kouvidi; Irene Mavroudi; Charalampos Pontikoglou; Papadaki, Helen A

    2013-01-01

    Immune-mediated bone marrow failure syndromes (BMFS) are characterized by ineffective marrow haemopoiesis and subsequent peripheral cytopenias. Ineffective haemopoiesis is the result of a complex marrow deregulation including genetic, epigenetic, and immune-mediated alterations in haemopoietic stem/progenitor cells, as well as abnormal haemopoietic-to-stromal cell interactions, with abnormal release of haemopoietic growth f