Regulatory CD4 T cells inhibit HIV-1 expression of other CD4 T cell subsets via interactions with cell surface regulatory proteins.

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Zhang, Mingce; Robinson, Tanya O; Duverger, Alexandra; Kutsch, Olaf; Heath, Sonya L; Cron, Randy Q

2018-03-01

During chronic HIV-1 infection, regulatory CD4 T cells (Tregs) frequently represent the largest subpopulation of CD4 T cell subsets, implying relative resistant to HIV-1. When HIV-1 infection of CD4 T cells was explored in vitro and ex vivo from patient samples, Tregs possessed lower levels of HIV-1 DNA and RNA in comparison with conventional effector and memory CD4 T cells. Moreover, Tregs suppressed HIV-1 expression in other CD4 T cells in an in vitro co-culture system. This suppression was mediated in part via multiple inhibitory surface proteins expressed on Tregs. Antibody blockade of CTLA-4, PD-1, and GARP on Tregs resulted in increased HIV-1 DNA integration and mRNA expression in neighboring CD4 T cells. Moreover, antibody blockade of Tregs inhibitory proteins resulted in increased HIV-1 LTR transcription in co-cultured CD4 T cells. Thus, Tregs inhibit HIV-1 infection of other CD4 T cell subsets via interactions with inhibitory cell surface proteins. Copyright © 2018 Elsevier Inc. All rights reserved.

Human Blood CD1c+ Dendritic Cells Promote Th1 and Th17 Effector Function in Memory CD4+ T Cells.

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Leal Rojas, Ingrid M; Mok, Wai-Hong; Pearson, Frances E; Minoda, Yoshihito; Kenna, Tony J; Barnard, Ross T; Radford, Kristen J

2017-01-01

Dendritic cells (DC) initiate the differentiation of CD4 + helper T cells into effector cells including Th1 and Th17 responses that play an important role in inflammation and autoimmune disease pathogenesis. In mice, Th1 and Th17 responses are regulated by different conventional (c) DC subsets, with cDC1 being the main producers of IL-12p70 and inducers of Th1 responses, while cDC2 produce IL-23 to promote Th17 responses. The role that human DC subsets play in memory CD4 + T cell activation is not known. This study investigated production of Th1 promoting cytokine IL-12p70, and Th17 promoting cytokines, IL-1β, IL-6, and IL-23, by human blood monocytes, CD1c + DC, CD141 + DC, and plasmacytoid DC and examined their ability to induce Th1 and Th17 responses in memory CD4 + T cells. Human CD1c + DC produced IL-12p70, IL-1β, IL-6, and IL-23 in response to R848 combined with LPS or poly I:C. CD141 + DC were also capable of producing IL-12p70 and IL-23 but were not as proficient as CD1c + DC. Activated CD1c + DC were endowed with the capacity to promote both Th1 and Th17 effector function in memory CD4 + T cells, characterized by high production of interferon-γ, IL-17A, IL-17F, IL-21, and IL-22. These findings support a role for CD1c + DC in autoimmune inflammation where Th1/Th17 responses play an important role in disease pathogenesis.

Regulatory function of cytomegalovirus-specific CD4+CD27-CD28- T cells

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Tovar-Salazar, Adriana; Patterson-Bartlett, Julie; Jesser, Renee; Weinberg, Adriana

2010-01-01

CMV infection is characterized by high of frequencies of CD27 - CD28 - T cells. Here we demonstrate that CMV-specific CD4 + CD27 - CD28 - cells are regulatory T cells (T R ). CD4 + CD27 - CD28 - cells sorted from CMV-stimulated PBMC of CMV-seropositive donors inhibited de novo CMV-specific proliferation of autologous PBMC in a dose-dependent fashion. Compared with the entire CMV-stimulated CD4 + T-cell population, higher proportions of CD4 + CD27 - CD28 - T R expressed FoxP3, TGFβ, granzyme B, perforin, GITR and PD-1, lower proportions expressed CD127 and PD1-L and similar proportions expressed CD25, CTLA4, Fas-L and GITR-L. CMV-CD4 + CD27 - CD28 - T R expanded in response to IL-2, but not to CMV antigenic restimulation. The anti-proliferative effect of CMV-CD4 + CD27 - CD28 - T R significantly decreased after granzyme B or TGFβ inhibition. The CMV-CD4 + CD27 - CD28 - T R of HIV-infected and uninfected donors had similar phenotypes and anti-proliferative potency, but HIV-infected individuals had higher proportions of CMV-CD4 + CD27 - CD28 - T R . The CMV-CD4 + CD27 - CD28 - T R may contribute to the downregulation of CMV-specific and nonspecific immune responses of CMV-infected individuals.

Dominant role of antigen dose in CD4+Foxp3+ regulatory T cell induction and expansion1

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Turner, Michael S.; Kane, Lawrence P.; Morel, Penelope A.

2009-01-01

The definitions of tolerogenic vs. immunogenic dendritic cells (DC) remain controversial. Immature DC have been shown to induce T regulatory cells (Treg) specific for foreign and allo-antigens. However, we have previously reported that mature DC (G4DC) prevented the onset of autoimmune diabetes whereas immature DC (GMDC) were therapeutically ineffective. In this study, islet-specific CD4+ T cells from BDC2.5 TCR Tg mice were stimulated, in the absence of exogenous cytokine, with GMDC or G4DC pulsed with high- or low-affinity antigenic peptides and examined for Treg induction. Both GMDC and G4DC presenting low peptide doses induced weak TCR signaling via the Akt/mTOR pathway, resulting in significant expansion of Foxp3+ Treg. Furthermore, unpulsed G4DC, but not GMDC, also induced Treg. High peptide doses induced strong Akt/mTOR signaling and favored the expansion of Foxp3neg Th cells. The inverse correlation of Foxp3 and Akt/mTOR signaling was also observed in DO11.10 and OT-II TCR-Tg T cells and was recapitulated with anti-CD3/CD28 stimulation in the absence of DC. IL-6 production in these cultures correlated positively with antigen dose and inversely with Treg expansion. Studies with T cells or DC from IL-6−/− mice revealed that IL-6 production by T cells was more important in the inhibition of Treg induction at low antigen doses. These studies indicate that strength of Akt/mTOR signaling, a critical T cell intrinsic determinant for Treg vs Th induction, can be controlled by adjusting the dose of antigenic peptide. Furthermore, this operates in a dominant fashion over DC phenotype and cytokine production. PMID:19801514

Hydroxychloroquine inhibits CD154 expression in CD4+ T lymphocytes of systemic lupus erythematosus through NFAT, but not STAT5, signaling.

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Wu, Shu-Fen; Chang, Chia-Bin; Hsu, Jui-Mei; Lu, Ming-Chi; Lai, Ning-Sheng; Li, Chin; Tung, Chien-Hsueh

2017-08-09

Overexpression of membranous CD154 in T lymphocytes has been found previously in systemic lupus erythematosus (SLE). Because hydroxychloroquine (HCQ) has been used frequently in the treatment of lupus, we sought to identify the effects of HCQ on CD154 and a possibly regulatory mechanism. CD4 + T cells were isolated from the blood of lupus patients. After stimulation with ionomycin or IL-15 and various concentrations of HCQ, expression of membranous CD154 and NFAT and STAT5 signaling were assessed. HCQ treatment had significant dose-dependent suppressive effects on membranous CD154 expression in ionomycin-activated T cells from lupus patients. Furthermore, HCQ inhibited intracellular sustained calcium storage release, and attenuated the nuclear translocation of NFATc2 and the expression of NFATc1. However, CD154 expressed through IL-15-mediated STAT5 signaling was not inhibited by HCQ treatment. HCQ inhibited NFAT signaling in activated T cells and blocked the expression of membranous CD154, but not STAT5 signaling. These findings provide a mechanistic insight into SLE in HCQ treatment.

Simian virus 40 inhibits differentiation and maturation of rhesus macaque DC-SIGN+-dendritic cells

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Changyong G

2010-09-01

Full Text Available Abstract Dendritic cells (DC are the initiators and modulators of the immune responses. Some species of pathogenic microorganisms have developed immune evasion strategies by controlling antigen presentation function of DC. Simian virus 40 (SV40 is a DNA tumor virus of rhesus monkey origin. It can induce cell transformation and tumorigenesis in many vertebrate species, but often causes no visible effects and persists as a latent infection in rhesus monkeys under natural conditions. To investigate the interaction between SV40 and rhesus monkey DC, rhesus monkey peripheral blood monocyte-derived DC were induced using recombinant human Interleukin-4 (rhIL-4 and infective SV40, the phenotype and function of DC-specific intracellular adhesion molecule-3 grabbing nonintegrin (DC-SIGN+ DC were analyzed by flow cytometry (FCM and mixed lymphocyte reaction (MLR. Results showed that SV40 can down-regulate the expression of CD83 and CD86 on DC and impair DC-induced activation of T cell proliferation. These findings suggest that SV40 might also cause immune suppression by influencing differentiation and maturation of DC.

Hesperidin Inhibits Inflammatory Response Induced by Aeromonas hydrophila Infection and Alters CD4+/CD8+ T Cell Ratio

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Abdelaziz S. A. Abuelsaad

2014-01-01

Full Text Available Background. Aeromonas hydrophila is an opportunistic bacterial pathogen that is associated with a number of human diseases. Hesperidin (HES has been reported to exert antioxidant and anti-inflammatory activities. Objectives. The aim of this study was to investigate the potential effect of HES treatment on inflammatory response induced by A. hydrophila infection in murine. Methods. A. hydrophila-infected mice were treated with HES at 250 mg/kg b.wt./week for 4 consecutive weeks. Phagocytosis, reactive oxygen species production, CD4+/CD8+ T cell ratio, and CD14 expression on intestinal infiltrating monocytes were evaluated. The expression of E-selectin and intercellular adhesion molecule 1 on stimulated HUVECs and RAW macrophage was evaluated. Results. Percentage of CD4+ T cells in the intestinal tissues of infected treated mice was highly significantly increased; however, phagocytic index, ROS production, CD8+ T cells percentage, and CD14 expression on monocytes were significantly reduced. On the other hand, HES significantly inhibited A-LPS- and A-ECP-induced E-selectin and ICAM-1 expression on HUVECs and ICAM-1 expression on RAW macrophage. Conclusion. Present data indicated that HES has a potential role in the suppression of inflammatory response induced by A. hydrophila toxins through downmodulation of ROS production and CD14 and adhesion molecules expression, as well as increase of CD4+/CD8+ cell ratio.

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

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

2010-02-01

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

Inhibition of HIV transmission in human cervicovaginal explants and humanized mice using CD4 aptamer-siRNA chimeras

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Wheeler, Lee Adam; Trifonova, Radiana; Vrbanac, Vladimir; Basar, Emre; McKernan, Shannon; Xu, Zhan; Seung, Edward; Deruaz, Maud; Dudek, Tim; Einarsson, Jon Ivar; Yang, Linda; Allen, Todd M.; Luster, Andrew D.; Tager, Andrew M.; Dykxhoorn, Derek M.; Lieberman, Judy

2011-01-01

The continued spread of the HIV epidemic underscores the need to interrupt transmission. One attractive strategy is a topical vaginal microbicide. Sexual transmission of herpes simplex virus type 2 (HSV-2) in mice can be inhibited by intravaginal siRNA application. To overcome the challenges of knocking down gene expression in immune cells susceptible to HIV infection, we used chimeric RNAs composed of an aptamer fused to an siRNA for targeted gene knockdown in cells bearing an aptamer-binding receptor. Here, we showed that CD4 aptamer-siRNA chimeras (CD4-AsiCs) specifically suppress gene expression in CD4+ T cells and macrophages in vitro, in polarized cervicovaginal tissue explants, and in the female genital tract of humanized mice. CD4-AsiCs do not activate lymphocytes or stimulate innate immunity. CD4-AsiCs that knock down HIV genes and/or CCR5 inhibited HIV infection in vitro and in tissue explants. When applied intravaginally to humanized mice, CD4-AsiCs protected against HIV vaginal transmission. Thus, CD4-AsiCs could be used as the active ingredient of a microbicide to prevent HIV sexual transmission. PMID:21576818

Effect of bone marrow-derived CD11b(+)F4/80 (+) immature dendritic cells on the balance between pro-inflammatory and anti-inflammatory cytokines in DBA/1 mice with collagen-induced arthritis.

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Fu, Jingjing; Zhang, Lingling; Song, Shanshan; Sheng, Kangliang; Li, Ying; Li, Peipei; Song, Shasha; Wang, Qingtong; Chu, Jianhong; Wei, Wei

2014-05-01

To explore the effect of bone marrow-derived CD11b(+)F4/80(+) immature dendritic cells (BM CD11b(+)F4/80(+)iDC) on the balance between pro-inflammatory and anti-inflammatory cytokines in DBA/1 mice with collagen-induced arthritis (CIA). BM CD11b(+)F4/80(+)iDC were induced with rmGM-CSF and rmIL-4, and were identified by the expressions of toll-like receptor 2 (TLR-2), indoleamine 2,3-deoxygenase (IDO), interleukin (IL)-10, transforming growth factor (TGF)-β1 and mixed leukocyte reaction (MLR). CIA was established in DBA/1 mice by immunization with type II collagen. CIA mice were injected intravenously with BM CD11b(+)F4/80(+)iDC three times after immunization. The effect of BM CD11b(+)F4/80(+)iDC on CIA was evaluated by the arthritis index, joint histopathology, body weight, thymus index, thymocytes proliferation, IL-1β, tumor necrosis factor (TNF)-α, IL-17, IL-10 and TGF-β1 levels. BM CD11b(+)F4/80(+)iDC induced with rmGM-CSF and rmIL-4 expressed high levels of TLR-2, IDO, IL-10 and TGF-β1. Infusion of BM CD11b(+)F4/80(+)iDC in CIA mice significantly reduced the arthritis index and pathological scores of joints, recovered the weight, decreased the thymus index and inhibited thymocyte proliferation. Levels of IL-1β, TNF-α and IL-17 were decreased in BM CD11b(+)F4/80(+)iDC-treated mice. BM CD11b(+)F4/80(+)iDC can be induced successfully with rmGM-CSF and rmIL-4. BM CD11b(+)F4/80(+)iDC treatment can ameliorate the development and severity of CIA by regulating the balance between pro-inflammatory cytokines and anti-inflammatory cytokines.

Mitofusin 2 Promotes Apoptosis of CD4+ T Cells by Inhibiting Autophagy in Sepsis

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Lan Ying

2017-01-01

Full Text Available Apoptosis of CD4+ T cells is a primary pathophysiological mechanism of immune dysfunction in the pathogenesis of sepsis. Mitofusin 2 (Mfn2, an integral mitochondrial outer membrane protein, has been confirmed to be associated with cellular metabolism, proliferation, and apoptosis. The function of Mfn2 in CD4+ T cell apoptosis in sepsis is poorly understood. Here, we discovered increased in vivo Mfn2 expression, autophagy deficiency, and elevated cell apoptosis in murine splenic CD4+ T cells after cecal ligation and puncture (CLP. We also observed almost identical results in splenic CD4+ T cells upon lipopolysaccharide (LPS stimulation in vitro. Furthermore, overexpression of Mfn2 resulted in impaired autophagy and increased apoptosis in Jurkat cells. Pharmacological inhibition of autophagy with 3-methyladenine enhanced Mfn2 overexpression-induced cell apoptosis. In addition, overexpression of Mfn2 downregulated phorbol myristate acetate (PMA/ionomycin-, rapamycin- and starvation-induced autophagy in Jurkat T cells. Taken together, these data indicate a critical role of Mfn2 in CD4+ T cell apoptosis in sepsis and the underlying mechanism of autophagy deficiency.

Role of the carbohydrate-binding sites of griffithsin in the prevention of DC-SIGN-mediated capture and transmission of HIV-1.

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Bart Hoorelbeke

Full Text Available BACKGROUND: The glycan-targeting C-type DC-SIGN lectin receptor is implicated in the transmission of the human immunodeficiency virus (HIV by binding the virus and transferring the captured HIV-1 to CD4(+ T lymphocytes. Carbohydrate binding agents (CBAs have been reported to block HIV-1 infection. We have now investigated the potent mannose-specific anti-HIV CBA griffithsin (GRFT on its ability to inhibit the capture of HIV-1 to DC-SIGN, its DC-SIGN-directed transmission to CD4(+ T-lymphocytes and the role of the three carbohydrate-binding sites (CBS of GRFT in these processes. FINDINGS: GRFT inhibited HIV-1(IIIB infection of CEM and HIV-1(NL4.3 infection of C8166 CD4(+ T-lymphocytes at an EC50 of 0.059 and 0.444 nM, respectively. The single mutant CBS variants of GRFT (in which a key Asp in one of the CBS was mutated to Ala were about ∼20 to 60-fold less potent to prevent HIV-1 infection and ∼20 to 90-fold less potent to inhibit syncytia formation in co-cultures of persistently HIV-1 infected HuT-78 and uninfected C8166 CD4(+ T-lymphocytes. GRFT prevents DC-SIGN-mediated virus capture and HIV-1 transmission to CD4(+ T-lymphocytes at an EC50 of 1.5 nM and 0.012 nM, respectively. Surface plasmon resonance (SPR studies revealed that wild-type GRFT efficiently blocked the binding between DC-SIGN and immobilized gp120, whereas the point mutant CBS variants of GRFT were ∼10- to 15-fold less efficient. SPR-analysis also demonstrated that wild-type GRFT and its single mutant CBS variants have the capacity to expel bound gp120 from the gp120-DC-SIGN complex in a dose dependent manner, a property that was not observed for HHA, another mannose-specific potent anti-HIV-1 CBA. CONCLUSION: GRFT is inhibitory against HIV gp120 binding to DC-SIGN, efficiently prevents DC-SIGN-mediated transfer of HIV-1 to CD4(+ T-lymphocytes and is able to expel gp120 from the gp120-DC-SIGN complex. Functionally intact CBS of GRFT are important for the optimal action of

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

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

2016-09-20

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

Dipeptidyl peptidase-4 (CD26): knowing the function before inhibiting the enzyme.

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Matteucci, E; Giampietro, O

2009-01-01

Dipeptidyl peptidase-4 (DPP4) or adenosine deaminase complexing protein 2 (ADCP 2) or T-cell activation antigen CD26 (EC 3.4.14.5.) is a serine exopeptidase belonging to the S9B protein family that cleaves X-proline dipeptides from the N-terminus of polypeptides, such as chemokines, neuropeptides, and peptide hormones. The enzyme is a type II transmembrane glycoprotein, expressed on the surface of many cell types, whose physiological functions are largely unknown. Protein dimerisation should be required for catalytic activity and glycosylation of the enzyme could impact on its physiological functions. The dimeric glycoprotein ADCP has been found linked to adenosine deaminase (ADA) whose relationship with lymphocyte maturation-differentiation is well-established. Since implicated in the regulation of the biological activity of hormones and chemokines, such as glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide, DPP4 inhibition offers a new potential therapeutic approach for type 2 diabetes mellitus, as monotherapy and adjunct therapy to other oral agents. The clinical use of presently available orally active inhibitors of DPP4, however, has been associated with side effects that have been in part attributed to the inhibition of related serine proteases, such as DPP8 and DPP9. Indeed, it is noteworthy that CD26 has a key role in immune regulation as a T cell activation molecule and in immune-mediated disorder. All-cause infections were increased after sitagliptin treatment. It is noteworthy that the effects of DPP4 inhibition on the immune system have not been extensively investigated. So far, only routine laboratory safety variables have been measured in published randomised controlled trials. The review summarises present knowledge in the field and suggests some potential directions of future research.

Inferior clinical outcome of the CD4+ cell count-guided antiretroviral treatment interruption strategy in the SMART study: role of CD4+ Cell counts and HIV RNA levels during follow-up

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Lundgren, Jens; Babiker, Abdel; El-Sadr, Wafaa

2008-01-01

BACKGROUND AND METHODS: The SMART study compared 2 strategies for using antiretroviral therapy-drug conservation (DC) and viral suppression (VS)-in 5,472 human immunodeficiency virus (HIV)-infected patients with CD4+ cell counts >350 cells/microL. Rates and predictors of opportunistic disease...... or death (OD/death) and the relative risk (RR) in DC versus VS groups according to the latest CD4+ cell count and HIV RNA level are reported. RESULTS: During a mean of 16 months of follow-up, DC patients spent more time with a latest CD4+ cell count ...%) and with a latest HIV RNA level >400 copies/mL (71% vs. 28%) and had a higher rate of OD/death (3.4 vs. 1.3/100 person-years) than VS patients. For periods of follow- up with a CD4+ cell count

Inhibition of VEGF-dependent angiogenesis by the anti-CD82 monoclonal antibody 4F9 through regulation of lipid raft microdomains

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Nomura, Sayaka; Iwata, Satoshi; Hatano, Ryo; Komiya, Eriko; Dang, Nam H.; Iwao, Noriaki; Ohnuma, Kei; Morimoto, Chikao

2016-01-01

CD82 (also known as KAI1) belongs to the tetraspanin superfamily of type III transmembrane proteins, and is involved in regulating cell adhesion, migration and proliferation. In contrast to these well-established roles of CD82 in tumor biology, its function in endothelial cell (EC) activity and tumor angiogenesis is yet to be determined. In this study, we show that suppression of CD82 negatively regulates vascular endothelial growth factor (VEGF)-induced angiogenesis. Moreover, we demonstrate that the anti-CD82 mAb 4F9 effectively inhibits phosphorylation of VEGF receptor 2 (VEGFR2), which is the principal mediator of the VEGF-induced angiogenic signaling process in tumor angiogenesis, by regulating the organization of the lipid raft microdomain signaling platform in human EC. Our present work therefore suggests that CD82 on EC is a potential target for anti-angiogenic therapy in VEGFR2-dependent tumor angiogenesis. -- Highlights: •Knockdown of CD82 decreases EC migration, proliferation and angiogenesis. •Anti-CD82 mAb 4F9 inhibits EC migration, proliferation and angiogenesis. •4F9 inhibits VEGFR2 phosphorylation via control of CD82 distribution in lipid rafts.

Inhibition of VEGF-dependent angiogenesis by the anti-CD82 monoclonal antibody 4F9 through regulation of lipid raft microdomains

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Nomura, Sayaka; Iwata, Satoshi; Hatano, Ryo [Division of Clinical Immunology, Advanced Clinical Research Center, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, 108-8639 (Japan); Komiya, Eriko [Department of Therapy Development and Innovation for Immune Disorders and Cancers, Graduate School of Medicine, Juntendo University, 2-1-1, Hongo, Bunkyo-ku, Tokyo, 113-8421 (Japan); Dang, Nam H. [Division of Hematology/Oncology, University of Florida, 1600 SW Archer Road- Box 100278, Room MSB M410A, Gainesville, FL, 32610 (United States); Iwao, Noriaki [Department of Hematology, School of Medicine, Juntendo University, 2-1-1, Hongo, Bunkyo-ku, Tokyo, 113-8421 (Japan); Ohnuma, Kei, E-mail: kohnuma@juntendo.ac.jp [Department of Rheumatology and Allergy, IMSUT Hospital, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, 108-8639 (Japan); Morimoto, Chikao [Division of Clinical Immunology, Advanced Clinical Research Center, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, 108-8639 (Japan); Department of Rheumatology and Allergy, IMSUT Hospital, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, 108-8639 (Japan)

2016-05-20

CD82 (also known as KAI1) belongs to the tetraspanin superfamily of type III transmembrane proteins, and is involved in regulating cell adhesion, migration and proliferation. In contrast to these well-established roles of CD82 in tumor biology, its function in endothelial cell (EC) activity and tumor angiogenesis is yet to be determined. In this study, we show that suppression of CD82 negatively regulates vascular endothelial growth factor (VEGF)-induced angiogenesis. Moreover, we demonstrate that the anti-CD82 mAb 4F9 effectively inhibits phosphorylation of VEGF receptor 2 (VEGFR2), which is the principal mediator of the VEGF-induced angiogenic signaling process in tumor angiogenesis, by regulating the organization of the lipid raft microdomain signaling platform in human EC. Our present work therefore suggests that CD82 on EC is a potential target for anti-angiogenic therapy in VEGFR2-dependent tumor angiogenesis. -- Highlights: •Knockdown of CD82 decreases EC migration, proliferation and angiogenesis. •Anti-CD82 mAb 4F9 inhibits EC migration, proliferation and angiogenesis. •4F9 inhibits VEGFR2 phosphorylation via control of CD82 distribution in lipid rafts.

Modulation of phenotype and function of human CD4+CD25+ T regulatory lymphocytes mediated by cAMP elevating agents

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Antonella Riccomi

2016-09-01

Full Text Available We have shown that Cholera Toxin (CT and other cyclic AMP (cAMP elevating agents induce up-regulation of the inhibitory molecule CTLA-4 in human resting CD4+ T lymphocytes, which following the treatment acquired suppressive functions. In this study, we evaluated the effect of cAMP elevating agents on human CD4+CD25+ T cells, which include the T regulatory (Treg cells that play a pivotal role in the maintenance of immunological tolerance. We found that cAMP elevating agents induce up-regulation of CTLA-4 in CD4+CD25- and further enhance its expression in CD4+CD25+ T cells. We observed an increase of two isoforms of mRNA coding for the membrane and the soluble CTLA-4 molecules, suggesting that the regulation of CTLA-4 expression by cAMP is at the transcriptional level. In addition, we found that the increase of cAMP in CD4+CD25+ T cells converts the CD4+CD25+Foxp3- T cells in CD4+CD25+Foxp3+ T cells, whereas the increase of cAMP in CD4+CD25- T cells did not up-regulate Foxp3 in the absence of activation stimuli. To investigate the function of these cells, we performed an in vitro suppression assay by culturing CD4+CD25+ T cells untreated or pre-treated with CT with anti-CD3 mAbs-stimulated autologous PBMC. We found that CT enhances the inhibitory function of CD4+CD25+ T cells, CD4+ and CD8+ T cell proliferation and IFNγ production are strongly inhibited by CD4+CD25+ T cells pre-treated with cAMP elevating agents. Furthermore, we found that CD4+CD25+ T lymphocytes pre-treated with cAMP elevating agents induce the up-regulation of CD80 and CD86 co-stimulatory molecules on immature dendritic cells (DCs in the absence of antigenic stimulation, however without leading to full DC maturation. These data show that the increase of intracellular cAMP modulates the phenotype and function of human CD4+CD25+ T cells.

Transgene IL-6 Enhances DC-Stimulated CTL Responses by Counteracting CD4+25+Foxp3+ Regulatory T Cell Suppression via IL-6-Induced Foxp3 Downregulation

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Kalpana Kalyanasundaram Bhanumathy

2014-03-01

Full Text Available Dendritic cells (DCs, the most potent antigen-presenting cells have been extensively applied in clinical trials for evaluation of antitumor immunity. However, the efficacy of DC-mediated cancer vaccines is still limited as they are unable to sufficiently break the immune tolerance. In this study, we constructed a recombinant adenoviral vector (AdVIL-6 expressing IL-6, and generated IL-6 transgene-engineered DC vaccine (DCOVA/IL-6 by transfection of murine bone marrow-derived ovalbumin (OVA-pulsed DCs (DCOVA with AdVIL-6. We then assessed DCOVA/IL-6-stimulated cytotoxic T-lymphocyte (CTL responses and antitumor immunity in OVA-specific animal tumor model. We demonstrate that DCOVA/IL-6 vaccine up-regulates expression of DC maturation markers, secretes transgene-encoded IL-6, and more efficiently stimulates OVA-specific CTL responses and therapeutic immunity against OVA-expressing B16 melanoma BL6-10OVA in vivo than the control DCOVA/Null vaccine. Moreover, DCOVA/IL-6-stimulated CTL responses were relatively maintained in mice with transfer of CD4+25+Foxp3+ Tr-cells, but significantly reduced when treated with anti-IL-6 antibody. In addition, we demonstrate that IL-6 down-regulates Foxp3-expression of CD4+25+Foxp3+ Tr-cells in vitro. Taken together, our results demonstrate that AdV-mediated IL-6 transgene-engineered DC vaccine stimulates potent CTL responses and antitumor immunity by counteracting CD4+25+ Tr immunosuppression via IL-6-induced Foxp3 down-regulation. Thus, IL-6 may be a good candidate for engineering DCs for cancer immunotherapy.

Hypoxia Enhances Immunosuppression by Inhibiting CD4+ Effector T Cell Function and Promoting Treg Activity

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Astrid M. Westendorf

2017-03-01

Full Text Available Background/Aims: Hypoxia occurs in many pathological conditions, including inflammation and cancer. Within this context, hypoxia was shown to inhibit but also to promote T cell responses. Due to this controversial function, we aimed to explore whether an insufficient anti-tumour response during colitis-associated colon cancer could be ascribed to a hypoxic microenvironment. Methods: Colitis-associated colon cancer was induced in wildtype mice, and hypoxia as well as T cell immunity were analysed in the colonic tumour tissues. In addition, CD4+ effector T cells and regulatory T cells were cultured under normoxic and hypoxic conditions and examined regarding their phenotype and function. Results: We observed severe hypoxia in the colon of mice suffering from colitis-associated colon cancer that was accompanied by a reduced differentiation of CD4+ effector T cells and an enhanced number and suppressive activity of regulatory T cells. Complementary ex vivo and in vitro studies revealed that T cell stimulation under hypoxic conditions inhibited the differentiation, proliferation and IFN-γ production of TH1 cells and enhanced the suppressive capacity of regulatory T cells. Moreover, we identified an active role for HIF-1α in the modulation of CD4+ T cell functions under hypoxic conditions. Conclusion: Our data indicate that oxygen availability can function as a local modulator of CD4+ T cell responses and thus influences tumour immune surveillance in inflammation-associated colon cancer.

NADPH oxidase-2 derived ROS dictates murine DC cytokine-mediated cell fate decisions during CD4 T helper-cell commitment.

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Meghan A Jendrysik

Full Text Available NADPH oxidase-2 (Nox2/gp91(phox and p47(phox deficient mice are prone to hyper-inflammatory responses suggesting a paradoxical role for Nox2-derived reactive oxygen species (ROS as anti-inflammatory mediators. The molecular basis for this mode of control remains unclear. Here we demonstrate that IFNγ/LPS matured p47(phox-/--ROS deficient mouse dendritic cells (DC secrete more IL-12p70 than similarly treated wild type DC, and in an in vitro co-culture model IFNγ/LPS matured p47(phox-/- DC bias more ovalbumin-specific CD4(+ T lymphocytes toward a Th1 phenotype than wild type (WT DC through a ROS-dependent mechanism linking IL-12p70 expression to regulation of p38-MAPK activation. The Nox2-dependent ROS production in DC negatively regulates proinflammatory IL-12 expression in DC by constraining p38-MAPK activity. Increasing endogenous H(2O(2 attenuates p38-MAPK activity in IFNγ/LPS stimulated WT and p47(phox-/- DC, which suggests that endogenous Nox 2-derived ROS functions as a secondary messenger in the activated p38-MAPK signaling pathway during IL-12 expression. These findings indicate that ROS, generated endogenously by innate and adaptive immune cells, can function as important secondary messengers that can regulate cytokine production and immune cell cross-talk to control during the inflammatory response.

T Lymphocyte Inhibition by Tumor-Infiltrating Dendritic Cells Involves Ectonucleotidase CD39 but Not Arginase-1

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Malika Trad

2015-01-01

Full Text Available T lymphocytes activated by dendritic cells (DC which present tumor antigens play a key role in the antitumor immune response. However, in patients suffering from active cancer, DC are not efficient at initiating and supporting immune responses as they participate to T lymphocyte inhibition. DC in the tumor environment are functionally defective and exhibit a characteristic of immature phenotype, different to that of DC present in nonpathological conditions. The mechanistic bases underlying DC dysfunction in cancer responsible for the modulation of T-cell responses and tumor immune escape are still being investigated. Using two different mouse tumor models, we showed that tumor-infiltrating DC (TIDC are constitutively immunosuppressive, exhibit a semimature phenotype, and impair responder T lymphocyte proliferation and activation by a mechanism involving CD39 ectoenzyme.

Soluble human CD4 elicits an antibody response in rhesus monkeys that inhibits simian immunodeficiency virus replication

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Watanabe, Mamoru; Chen, Zheng W.; Tsubota, Hiroshi; Lord, C.I.; Levine, C.G.; Letvin, N.L.

1991-01-01

Rhesus monkeys infected with the simian immunodeficiency virus of macaques (SIV mac ) demonstrate significant virologic and clinical improvement as a result of treatment with human recombinant soluble CD4 (rsCD4). The authors show that human rsCD4 does not efficiently inhibit SIV mac replication in bone marrow macrophages of rhesus monkeys and does not significantly augment bone marrow hematopoietic colony formation in vitro. However, plasma of human rsCD4-treated rhesus monkeys does exhibit significant anti-SIV mac activity in vitro. Plasma of these animals efficiently blocks SIV mac replicaton in peripheral blood lymphocytes and bone marrow macrophages. It also increases granulocyte/macrophage colony formation in vitro by bone marrow cells of SIV mac -infected monkeys. This plasma and the IgG fraction of plasma from a rhesus monkey immunized with human rsCD4 in adjuvant demonstrate reactivity with a soluble form of the rhesus monkey CD4 molecule, exhibit binding to CD4 + but not CD8 + concanavalin A-activated rhesus monkey peripheral blood lymphocytes, and precipitate the CD4 molecule from surface-labeled activated rhesus monkey peripheral blood lymphocytes. Moreover, anti-viral activity is demonstrable in the IgG fraction of plasma from a human rsCD4-immunized monkey. These studies raise the possibility that a modified human CD4 molecule serving as an immunogen might elicit an antibody response that could potentially induce a beneficial therapeutic response in human immunodeficiency virus-infected individuals

MS4a4B, a CD20 homologue in T cells, inhibits T cell propagation by modulation of cell cycle.

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Hui Xu

2010-11-01

Full Text Available MS4a4B, a CD20 homologue in T cells, is a novel member of the MS4A gene family in mice. The MS4A family includes CD20, FcεRIβ, HTm4 and at least 26 novel members that are characterized by their structural features: with four membrane-spanning domains, two extracellular domains and two cytoplasmic regions. CD20, FcεRIβ and HTm4 have been found to function in B cells, mast cells and hematopoietic cells respectively. However, little is known about the function of MS4a4B in T cell regulation. We demonstrate here that MS4a4B negatively regulates mouse T cell proliferation. MS4a4B is highly expressed in primary T cells, natural killer cells (NK and some T cell lines. But its expression in all malignant T cells, including thymoma and T hybridoma tested, was silenced. Interestingly, its expression was regulated during T cell activation. Viral vector-driven overexpression of MS4a4B in primary T cells and EL4 thymoma cells reduced cell proliferation. In contrast, knockdown of MS4a4B accelerated T cell proliferation. Cell cycle analysis showed that MS4a4B regulated T cell proliferation by inhibiting entry of the cells into S-G2/M phase. MS4a4B-mediated inhibition of cell cycle was correlated with upregulation of Cdk inhibitory proteins and decreased levels of Cdk2 activity, subsequently leading to inhibition of cell cycle progression. Our data indicate that MS4a4B negatively regulates T cell proliferation. MS4a4B, therefore, may serve as a modulator in the negative-feedback regulatory loop of activated T cells.

MS4a4B, a CD20 homologue in T cells, inhibits T cell propagation by modulation of cell cycle.

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Xu, Hui; Yan, Yaping; Williams, Mark S; Carey, Gregory B; Yang, Jingxian; Li, Hongmei; Zhang, Guang-Xian; Rostami, Abdolmohamad

2010-11-01

MS4a4B, a CD20 homologue in T cells, is a novel member of the MS4A gene family in mice. The MS4A family includes CD20, FcεRIβ, HTm4 and at least 26 novel members that are characterized by their structural features: with four membrane-spanning domains, two extracellular domains and two cytoplasmic regions. CD20, FcεRIβ and HTm4 have been found to function in B cells, mast cells and hematopoietic cells respectively. However, little is known about the function of MS4a4B in T cell regulation. We demonstrate here that MS4a4B negatively regulates mouse T cell proliferation. MS4a4B is highly expressed in primary T cells, natural killer cells (NK) and some T cell lines. But its expression in all malignant T cells, including thymoma and T hybridoma tested, was silenced. Interestingly, its expression was regulated during T cell activation. Viral vector-driven overexpression of MS4a4B in primary T cells and EL4 thymoma cells reduced cell proliferation. In contrast, knockdown of MS4a4B accelerated T cell proliferation. Cell cycle analysis showed that MS4a4B regulated T cell proliferation by inhibiting entry of the cells into S-G2/M phase. MS4a4B-mediated inhibition of cell cycle was correlated with upregulation of Cdk inhibitory proteins and decreased levels of Cdk2 activity, subsequently leading to inhibition of cell cycle progression. Our data indicate that MS4a4B negatively regulates T cell proliferation. MS4a4B, therefore, may serve as a modulator in the negative-feedback regulatory loop of activated T cells.

The Metalloporphyrin Antioxidant, MnTE-2-PyP, Inhibits Th2 Cell Immune Responses in an Asthma Model

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Paiboon Jungsuwadee

2012-08-01

Full Text Available MnTE-2-PyP, a superoxide dismutase mimetic, inhibited OVA-induced airway inflammation in mice suggesting an effect on Th2 responsiveness. Thus, we hypothesized that MnTE-2-PyP may alter dendritic cell-Th2 interactions. Bone marrow derived dendritic cells (DC and OVA_323-339-specific Th2 cells were cultured separately in the presence or absence of MnTE-2-PyP for 3 days prior to the co-culturing of the two cell types in the presence of an OVA_323-339 peptide and in some cases stimulated with CD3/CD28. MnTE-2-PyP-pretreated DC inhibited IL-4, IL-5 and IFNγ production and inhibited Th2 cell proliferation in the DC-Th2 co-culturing system in the presence of the OVA_323-339 peptide. Similar results were obtained using the CD3/CD28 cell-activation system; the addition of MnTE-2-PyP inhibited Th2 cell proliferation. MnTE-2-PyP suppressed CD25 expression on OVA-specific Th2 cells, which implied that MnTE-2-PyP can inhibit the activation of Th2 cells. MnTE-2-PyP also down-regulated co-stimulatory molecules: CD40, CD80 and CD86 on immature DC. Our studies suggest that the major mechanism by which MnTE-2-PyP inhibits airway inflammation is by acting on the DC and suppressing Th2 cell proliferation and activation.

Methionine enkephalin (MENK) inhibits tumor growth through regulating CD4+Foxp3+ regulatory T cells (Tregs) in mice.

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Li, Xuan; Meng, Yiming; Plotnikoff, Nicolas P; Youkilis, Gene; Griffin, Noreen; Wang, Enhua; Lu, Changlong; Shan, Fengping

2015-01-01

Methionine enkephalin (MENK), an endogenous neuropeptide, plays an crucial role in both neuroendocrine and immune systems. CD4+Foxp3+ regulatory T cells (Tregs) are identified as a major subpopulation of T lymphocytes in suppressing immune system to keep balanced immunity. The aim of this research work was to elucidate the mechanisms via which MENK interacts with Tregs in cancer situation. The influence of MENK on transforming growth factor-β (TGF-β) mediated conversion from naïve CD4+CD25- T cells to CD4+CD25+ Tregs was determined and the data from flow cytometry (FCM) analysis indicated that MENK effectively inhibited the expression of Foxp3 during the process of TGF-βinduction. Furthermore, this inhibiting process was accompanied by diminishing phosphorylation and nuclear translocation of Smad2/3, confirmed by western blot (WB) analysis and immunofluorescence (IF) at molecular level. We established sarcoma mice model with S180 to investigate whether MENK could modulate Tregs in tumor circumstance. Our findings showed that MENK delayed the development of tumor in S180 tumor bearing mice and down-regulated level of Tregs. Together, these novel findings reached a conclusion that MENK could inhibit Tregs activity directly and retard tumor development through down-regulating Tregs in mice. This work advances the deepening understanding of the influence of MENK on Tregs in cancer situation, and relation of MENK with immune system, supporting the implication of MENK as a new strategy for cancer immunotherapy.

HBV-Derived Synthetic Long Peptide Can Boost CD4+ and CD8+ T-Cell Responses in Chronic HBV Patients Ex Vivo.

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Dou, Yingying; van Montfoort, Nadine; van den Bosch, Aniek; de Man, Robert A; Zom, Gijs G; Krebber, Willem-Jan; Melief, Cornelis J M; Buschow, Sonja I; Woltman, Andrea M

2018-02-14

Vaccination with synthetic long peptides (SLP) is a promising new treatment strategy for chronic hepatitis B virus (CHB). SLP can induce broad T-cell responses for all HLA types. Here we investigated the ability of a prototype HBV-core (HBc)-sequence-derived SLP to boost HBV-specific T cells in CHB patients ex vivo. HBc-SLP was used to assess cross-presentation by monocyte-derived dendritic cells (moDC) and BDCA1+ blood myeloid DC (mDC) to engineered HBV-specific CD8+ T cells. Autologous SLP-loaded and toll-like receptor (TLR)-stimulated DC were used to activate patient HBc-specific CD8+ and CD4+ T cells. HBV-SLP was cross-presented by moDC, which was further enhanced by adjuvants. Patient-derived SLP-loaded moDC significantly increased autologous HBcAg18-27-specific CD8+ T cells and CD4+ T cells ex vivo. HBV-specific T cells were functional as they synthesized tumor necrosis factor-alpha and interferon-gamma. In 6/7 of patients blockade of PD-L1 further increased SLP effects. Also, importantly, patient-derived BDCA1+ mDC cross-presented and activated autologous T-cell responses ex vivo. As a proof of concept, we showed a prototype HBc-SLP can boost T-cell responses in patients ex vivo. These results pave the way for the development of a therapeutic SLP-based vaccine to induce effective HBV-specific adaptive immune responses in CHB patients. © The Author(s) 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Monitoring the initiation and kinetics of human dendritic cell-induced polarization of autologous naive CD4+ T cells.

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Tammy Oth

Full Text Available A crucial step in generating de novo immune responses is the polarization of naive cognate CD4+ T cells by pathogen-triggered dendritic cells (DC. In the human setting, standardized DC-dependent systems are lacking to study molecular events during the initiation of a naive CD4+ T cell response. We developed a TCR-restricted assay to compare different pathogen-triggered human DC for their capacities to instruct functional differentiation of autologous, naive CD4+ T cells. We demonstrated that this methodology can be applied to compare differently matured DC in terms of kinetics, direction, and magnitude of the naive CD4+ T cell response. Furthermore, we showed the applicability of this assay to study the T cell polarizing capacity of low-frequency blood-derived DC populations directly isolated ex vivo. This methodology for addressing APC-dependent instruction of naive CD4+ T cells in a human autologous setting will provide researchers with a valuable tool to gain more insight into molecular mechanisms occurring in the early phase of T cell polarization. In addition, it may also allow the study of pharmacological agents on DC-dependent T cell polarization in the human system.

Percentage and function of CD4+CD25+ regulatory T cells in patients with hyperthyroidism

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Jiang, Ting-Jun; Cao, Xue-Liang; Luan, Sha; Cui, Wan-Hui; Qiu, Si-Huang; Wang, Yi-Chao; Zhao, Chang-Jiu; Fu, Peng

2018-01-01

The current study observed the percentage of peripheral blood (PB) CD4+CD25+ regulatory T cells (Tregs) and the influence of CD4+CD25+ Tregs on the proliferation of naïve CD4 T cells in patients with hyperthyroidism. Furthermore, preliminary discussions are presented on the action mechanism of CD4+CD25+ Tregs on hyperthyroidism attacks. The present study identified that compared with the percentage of PB CD4+CD25+ Tregs in healthy control subjects, no significant changes were observed in the percentage of PB CD4+CD25+ Tregs in patients with hyperthyroidism (P>0.05). For patients with hyperthyroidism, CD4+CD25+ Tregs exhibited significantly reduced inhibition of the proliferation of naïve CD4 T cells and decreased secretion capacity on the cytokines of CD4 T cells, compared with those of healthy control subjects (Phyperthyroidism was significantly improved (Phyperthyroidism before treatment, no significant changes were observed in the percentage of PB CD4+CD25+ Tregs in hyperthyroidism patients following treatment (P>0.05). In the patients with hyperthyroidism, following treatment, CD4+CD25+ Tregs exhibited significantly increased inhibition of the proliferation of naïve CD4 T cells and increased secretion capacity of CD4 T cell cytokines, compared with those of the patients with hyperthyroidism prior to treatment (Phyperthyroidism, and its non-proportional decrease may be closely associated with the occurrence and progression of hyperthyroidism. PMID:29207121

Synovial CD4+ T-cell-derived GM-CSF supports the differentiation of an inflammatory dendritic cell population in rheumatoid arthritis

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Reynolds, G; Gibbon, J R; Pratt, A G; Wood, M J; Coady, D; Raftery, G; Lorenzi, A R; Gray, A; Filer, A; Buckley, C D; Haniffa, M A; Isaacs, J D; Hilkens, C M U

2016-01-01

Objective A population of synovial inflammatory dendritic cells (infDCs) has recently been identified in rheumatoid arthritis (RA) and is thought to be monocyte-derived. Here, we investigated the role and source of granulocyte macrophage-colony-stimulating factor (GM-CSF) in the differentiation of synovial infDC in RA. Methods Production of GM-CSF by peripheral blood (PB) and synovial fluid (SF) CD4+ T cells was assessed by ELISA and flow cytometry. In vitro CD4+ T-cell polarisation experiments were performed with T-cell activating CD2/CD3/CD28-coated beads in the absence or presence of pro-Th1 or pro-Th17 cytokines. CD1c+ DC and CD16+ macrophage subsets were flow-sorted and analysed morphologically and functionally (T-cell stimulatory/polarising capacity). Results RA-SF CD4+ T cells produced abundant GM-CSF upon stimulation and significantly more than RA-SF mononuclear cells depleted of CD4+ T cells. GM-CSF-producing T cells were significantly increased in RA-SF compared with non-RA inflammatory arthritis SF, active RA PB and healthy donor PB. GM-CSF-producing CD4+ T cells were expanded by Th1-promoting but not Th17-promoting conditions. Following coculture with RA-SF CD4+ T cells, but not healthy donor PB CD4+ T cells, a subpopulation of monocytes differentiated into CD1c+ infDC; a process dependent on GM-CSF. These infDC displayed potent alloproliferative capacity and enhanced GM-CSF, interleukin-17 and interferon-γ production by CD4+ T cells. InfDC with an identical phenotype to in vitro generated cells were significantly enriched in RA-SF compared with non-RA-SF/tissue/PB. Conclusions We demonstrate a therapeutically tractable feedback loop of GM-CSF secreted by RA synovial CD4+ T cells promoting the differentiation of infDC with potent capacity to induce GM-CSF-producing CD4+ T cells. PMID:25923217

Potent Inhibition of HIV-1 Replication in Resting CD4 T Cells by Resveratrol and Pterostilbene.

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Chan, Chi N; Trinité, Benjamin; Levy, David N

2017-09-01

HIV-1 infection of resting CD4 T cells plays a crucial and numerically dominant role during virus transmission at mucosal sites and during subsequent acute replication and T cell depletion. Resveratrol and pterostilbene are plant stilbenoids associated with several health-promoting benefits. Resveratrol has been shown to inhibit the replication of several viruses, including herpes simplex viruses 1 and 2, papillomaviruses, severe acute respiratory syndrome virus, and influenza virus. Alone, resveratrol does not inhibit HIV-1 infection of activated T cells, but it does synergize with nucleoside reverse transcriptase inhibitors in these cells to inhibit reverse transcription. Here, we demonstrate that resveratrol and pterostilbene completely block HIV-1 infection at a low micromolar dose in resting CD4 T cells, primarily at the reverse transcription step. The anti-HIV effect was fully reversed by exogenous deoxynucleosides and Vpx, an HIV-1 and simian immunodeficiency virus protein that increases deoxynucleoside triphosphate (dNTP) levels. These findings are consistent with the reported ability of resveratrol to inhibit ribonucleotide reductase and to lower dNTP levels in cells. This study supports the potential use of resveratrol, pterostilbene, or related compounds as adjuvants in anti-HIV preexposure prophylaxis (PrEP) formulations. Copyright © 2017 American Society for Microbiology.

Kalimeris integrifolia Turcz. ex DC.: An accumulator of Cd

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Wei Shuhe; Zhou Qixing; Srivastava, Mrittunjai; Xiao Hong; Yang Chuanjie; Zhang Qianru

2009-01-01

Phytoremediation is a traditional technique that uses vegetation to remediate contaminants from water, soil and sediments. This is a solar-driven, aesthetically pleasing, and cost effective technology. In a former published article, Kalimeris integrifolia Turcz. ex DC. indicated some basic properties of hyperaccumulators for cadmium (Cd). In this study, concentration gradient experiment and sample-analyzing experiments were used to assess whether this plant is a Cd-hyperaccumulator. The results showed the Cd enrichment factor (concentration in plant/soil) and Cd translocation factor (concentration in shoot/root) of K. integrifolia was basically >1 in concentration gradient experiment. Shoot biomass was not reduced significantly (p -1 , the threshold concentration for a Cd-hyperaccumulator. Thus, K. integrifolia should only be considered as a Cd-accumulator. In the sample-analyzing experiments conducted in a Pb-Zn mine area and a wastewater irrigation region, K. integrifolia also showed Cd-accumulator properties. Based on these results, K. integrifolia could be identified as a Cd-accumulator

Inefficient HIV-1 trans infection of CD4+ T cells by macrophages from HIV-1 nonprogressors is associated with altered membrane cholesterol and DC-SIGN.

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DeLucia, Diana C; Rinaldo, Charles R; Rappocciolo, Giovanna

2018-04-11

Professional antigen presenting cells (APC: myeloid dendritic cells (DC) and macrophages (MΦ); B lymphocytes) mediate highly efficient HIV-1 infection of CD4 + T cells, termed trans infection, that could contribute to HIV-1 pathogenesis. We have previously shown that lower cholesterol content in DC and B lymphocytes is associated with a lack of HIV-1 trans infection in HIV-1 infected nonprogressors (NP). Here we assessed whether HIV-1 trans infection mediated by another major APC, MΦ, is deficient in NP due to altered cholesterol metabolism. When comparing healthy HIV-1 seronegatives (SN), rapid progressors (PR), and NP, we found that monocyte-derived MΦ from NP did not mediate HIV-1 trans infection of autologous CD4 + T cells, in contrast to efficient trans infection mediated by SN and PR MΦ. MΦ trans infection efficiency was directly associated with the number of DC-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN)-expressing MΦ. Significantly fewer NP MΦ expressed DC-SIGN. Unesterified (free) cholesterol in MΦ cell membranes and lipid rafting was significantly lower in NP than PR, as well as virus internalization in early endosomes. Furthermore, simvastatin (SIMV), decreased the subpopulation of DC-SIGN + MΦ, as well as MΦ cis and trans infection. Notably, SIMV decreased cell membrane cholesterol and led to lipid raft dissociation, effectively mimicking the incompetent APC trans infection environment characteristic of NP. Our data support that DC-SIGN and membrane cholesterol are central to MΦ trans infection, and a lack of these limits HIV-1 disease progression. Targeting the ability of MΦ to drive HIV-1 dissemination in trans could enhance HIV-1 therapeutic strategies. IMPORTANCE Despite the success of combination anti-retroviral therapy, neither a vaccine nor a cure for HIV infection has been developed, demonstrating a need for novel prophylactic and therapeutic strategies. Here we show that efficiency of macrophage (M�

IL-15 augments TCR-induced CD4+ T cell expansion in vitro by inhibiting the suppressive function of CD25 High CD4+ T cells.

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Tom L Van Belle

Full Text Available Due to its critical role in NK cell differentiation and CD8(+ T cell homeostasis, the importance of IL-15 is more firmly established for cytolytic effectors of the immune system than for CD4(+ T cells. The increased levels of IL-15 found in several CD4(+ T cell-driven (auto- immune diseases prompted us to examine how IL-15 influences murine CD4(+ T cell responses to low dose TCR-stimulation in vitro. We show that IL-15 exerts growth factor activity on both CD4(+ and CD8(+ T cells in a TCR-dependent and Cyclosporin A-sensitive manner. In CD4(+ T cells, IL-15 augmented initial IL-2-dependent expansion and once IL-15Rα was upregulated, IL-15 sustained the TCR-induced expression of IL-2/15Rβ, supporting proliferation independently of secreted IL-2. Moreover, IL-15 counteracts CD4(+ T cell suppression by a gradually expanding CD25(HighCD4(+ T cell subset that expresses Foxp3 and originates from CD4(+CD25(+ Tregs. These in vitro data suggest that IL-15 may dramatically strengthen the T cell response to suboptimal TCR-triggering by overcoming an activation threshold set by Treg that might create a risk for autoimmune pathology.

MECHANICAL VIBRATION INHIBITS OSTEOCLAST FORMATION BY REDUCING DC-STAMP RECEPTOR EXPRESSION IN OSTEOCLAST PRECURSOR CELLS

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Kulkarni, R.N.; Voglewede, P.A.; Liu, D.

2014-01-01

It is well known that physical inactivity leads to loss of muscle mass, but it also causes bone loss. Mechanistically, osteoclastogenesis and bone resorption have recently been shown to be regulated by vibration. However, the underlying mechanism behind the inhibition of osteoclast formation is yet unknown. Therefore, we investigated whether mechanical vibration of osteoclast precursor cells affects osteoclast formation by the involvement of fusion-related molecules such as dendritic cell-specific transmembrane protein (DC-STAMP), and P2X7 receptor (P2X7R). RAW264.7 (a murine osteoclastic-like cell line) cells were treated with 20 ng/ml receptor activator of NF-κB ligand (RANKL). For 3 consecutive days, the cells were subjected to 1 hour of mechanical vibration with 20 µm displacement at a frequency of 4 Hz and compared to the control cells that were treated under the same condition but without the vibration. After 5 days of culture, osteoclast formation was determined. Gene expression of DC-STAMP and P2X7R by RAW264.7 cells were determined after 1 hour mechanical vibration, while protein production of the DC-STAMP was determined after 6 hours of post incubation after vibration. As a result, mechanical vibration of RAW264.7 cells inhibited the formation of osteoclasts. Vibration down-regulated DC-STAMP gene expression by 1.6-fold in the presence of RANKL and by 1.4-fold in the absence of RANKL. Additionally, DC-STAMP protein production was also down-regulated by 1.4-fold in the presence of RANKL and by 1.2-fold in the absence of RANKL in RAW264.7 cells in response to mechanical vibration. However, vibration did not affect P2X7R gene expression. Mouse anti-DC-STAMP antibody inhibited osteoclast formation in the absence of vibration. Our results suggest that mechanical vibration of osteoclast precursor cells reduce DC-STAMP expression in osteoclast precursor cells leading to the inhibition of osteoclast formation. PMID:23994170

Mechanical vibration inhibits osteoclast formation by reducing DC-STAMP receptor expression in osteoclast precursor cells.

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Kulkarni, Rishikesh N; Voglewede, Philip A; Liu, Dawei

2013-12-01

It is well known that physical inactivity leads to loss of muscle mass, but it also causes bone loss. Mechanistically, osteoclastogenesis and bone resorption have recently been shown to be regulated by vibration. However, the underlying mechanism behind the inhibition of osteoclast formation is yet unknown. Therefore, we investigated whether mechanical vibration of osteoclast precursor cells affects osteoclast formation by the involvement of fusion-related molecules such as dendritic cell-specific transmembrane protein (DC-STAMP) and P2X7 receptor (P2X7R). RAW264.7 (a murine osteoclastic-like cell line) cells were treated with 20ng/ml receptor activator of NF-κB ligand (RANKL). For 3 consecutive days, the cells were subjected to 1h of mechanical vibration with 20μm displacement at a frequency of 4Hz and compared to the control cells that were treated under the same condition but without the vibration. After 5days of culture, osteoclast formation was determined. Gene expression of DC-STAMP and P2X7R by RAW264.7 cells was determined after 1h of mechanical vibration, while protein production of the DC-STAMP was determined after 6h of postincubation after vibration. As a result, mechanical vibration of RAW264.7 cells inhibited the formation of osteoclasts. Vibration down-regulated DC-STAMP gene expression by 1.6-fold in the presence of RANKL and by 1.4-fold in the absence of RANKL. Additionally, DC-STAMP protein production was also down-regulated by 1.4-fold in the presence of RANKL and by 1.2-fold in the absence of RANKL in RAW264.7 cells in response to mechanical vibration. However, vibration did not affect P2X7R gene expression. Mouse anti-DC-STAMP antibody inhibited osteoclast formation in the absence of vibration. Our results suggest that mechanical vibration of osteoclast precursor cells reduces DC-STAMP expression in osteoclast precursor cells leading to the inhibition of osteoclast formation. © 2013 Elsevier Inc. All rights reserved.

Mucosal stromal fibroblasts markedly enhance HIV infection of CD4+ T cells.

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Jason A Neidleman

2017-02-01

Full Text Available Understanding early events of HIV transmission within mucosal tissues is vital for developing effective prevention strategies. Here, we report that primary stromal fibroblasts isolated from endometrium, cervix, foreskin, male urethra, and intestines significantly increase HIV infection of CD4+ T cells-by up to 37-fold for R5-tropic HIV and 100-fold for X4-tropic HIV-without themselves becoming infected. Fibroblasts were more efficient than dendritic cells at trans-infection and mediate this response in the absence of the DC-SIGN and Siglec-1 receptors. In comparison, mucosal epithelial cells secrete antivirals and inhibit HIV infection. These data suggest that breaches in the epithelium allow external or luminal HIV to escape an antiviral environment to access the infection-favorable environment of the stromal fibroblasts, and suggest that resident fibroblasts have a central, but previously unrecognized, role in HIV acquisition at mucosal sites. Inhibiting fibroblast-mediated enhancement of HIV infection should be considered as a novel prevention strategy.

Paclitaxel-Fe3O4 nanoparticles inhibit growth of CD138–  CD34– tumor stem-like cells in multiple myeloma-bearing mice

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Yang C

2013-04-01

Full Text Available Cuiping Yang,1,3,* Jing Wang,2,* Dengyu Chen,1,* Junsong Chen,1 Fei Xiong,4 Hongyi Zhang,1 Yunxia Zhang,2 Ning Gu,4 Jun Dou11Department of Pathogenic Biology and Immunology, Medical School, 2Department of Gynecology and Obstetrics, Zhongda Hospital, Southeast University, Nanjing, 3Department of Pathogenic Biology and Immunology, School of Basic Medicine, Jiangxi University of Traditional Chinese Medicine, Nanchang, 4School of Biological Science and Medical Engineering, Southeast University, Nanjing, People’s Republic of China*These authors contributed equally to this workBackground: There is growing evidence that CD138– CD34– cells may actually be tumor stem cells responsible for initiation and relapse of multiple myeloma. However, effective drugs targeted at CD138– CD34– tumor stem cells are yet to be developed. The purpose of this study was to investigate the inhibitory effect of paclitaxel-loaded Fe3O4 nanoparticles (PTX-NPs on CD138– CD34– tumor stem cells in multiple myeloma-bearing mice.Methods: CD138– CD34– cells were isolated from a human U266 multiple myeloma cell line using an immune magnetic bead sorting method and then subcutaneously injected into mice with nonobese diabetic/severe combined immunodeficiency to develop a multiple myeloma-bearing mouse model. The mice were treated with Fe3O4 nanoparticles 2 mg/kg, paclitaxel 4.8 mg/kg, and PTX-NPs 0.64 mg/kg for 2 weeks. Tumor growth, pathological changes, serum and urinary interleukin-6 levels, and molecular expression of caspase-3, caspase-8, and caspase-9 were evaluated.Results: CD138– CD34– cells were found to have tumor stem cell characteristics. All the mice developed tumors in 40 days after injection of 1 × 106 CD138– CD34– tumor stem cells. Tumor growth in mice treated with PTX-NPs was significantly inhibited compared with the controls (P <  0.005, and the groups that received nanoparticles alone (P < 0.005 or paclitaxel alone (P < 0.05. In addition

Activation-Induced TIM-4 Expression Identifies Differential Responsiveness of Intestinal CD103+ CD11b+ Dendritic Cells to a Mucosal Adjuvant.

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Kerry L Hilligan

Full Text Available Macrophage and dendritic cell (DC populations residing in the intestinal lamina propria (LP are highly heterogeneous and have disparate yet collaborative roles in the promotion of adaptive immune responses towards intestinal antigen. Under steady-state conditions, macrophages are efficient at acquiring antigen but are non-migratory. In comparison, intestinal DC are inefficient at antigen uptake but migrate to the mesenteric lymph nodes (mLN where they present antigen to T cells. Whether such distinction in the roles of DC and macrophages in the uptake and transport of antigen is maintained under immunostimulatory conditions is less clear. Here we show that the scavenger and phosphatidylserine receptor T cell Immunoglobulin and Mucin (TIM-4 is expressed by the majority of LP macrophages at steady-state, whereas DC are TIM-4 negative. Oral treatment with the mucosal adjuvant cholera toxin (CT induces expression of TIM-4 on a proportion of CD103+ CD11b+ DC in the LP. TIM-4+ DC selectively express high levels of co-stimulatory molecules after CT treatment and are detected in the mLN a short time after appearing in the LP. Importantly, intestinal macrophages and DC expressing TIM-4 are more efficient than their TIM-4 negative counterparts at taking up apoptotic cells and soluble antigen ex vivo. Taken together, our results show that CT induces phenotypic changes to migratory intestinal DC that may impact their ability to take up local antigens and in turn promote the priming of mucosal immunity.

In situ targeting of dendritic cells sets tolerogenic environment and ameliorates CD4+ T-cell response in the postischemic liver.

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Funken, Dominik; Ishikawa-Ankerhold, Hellen; Uhl, Bernd; Lerchenberger, Maximilian; Rentsch, Markus; Mayr, Doris; Massberg, Steffen; Werner, Jens; Khandoga, Andrej

2017-11-01

CD4 + T cells recruited to the liver play a key role in the pathogenesis of ischemia/reperfusion (I/R) injury. The mechanism of their activation during alloantigen-independent I/R is not completely understood. We hypothesized that liver-resident dendritic cells (DCs) interact with CD4 + T cells in the postischemic liver and that modulation of DCs or T-cell-DC interactions attenuates liver inflammation. In mice, warm hepatic I/R (90/120-240 min) was induced. Tolerogenic DCs were generated in situ by pretreatment of animals with the vitamin D analog paricalcitol. A mAb-CD44 was used for blockade of CD4 + T-cell-DC interactions. As shown by 2-photon in vivo microscopy as well as confocal microscopy, CD4 + T cells were closely colocalized with DCs in the postischemic liver. Pretreatment with paricalcitol attenuated I/R-induced maturation of DCs (flow cytometry), CD4 + T-cell recruitment into the liver (intravital microscopy), and hepatocellular/microvascular damage (intravital microscopy, alanine aminotransferase/aspartate aminotransferase, histology). However, interruption of T-cell-DC interaction increased proinflammatory DC maturation and even enhanced tissue damage. Simultaneous treatment with an anti-CD44mAb completely abolished the beneficial effect of paricalcitol on T-cell migration and tissue injury. Our study demonstrates for the first time that hepatic DCs interact with CD4 + T cells in the postischemic liver in vivo ; modulation of DCs and/or generation of tolerogenic DCs attenuates intrahepatic CD4 + T-cell recruitment and reduces I/R injury; and interruption of CD44-dependent CD4 + T-cell-DC interactions enhances tissue injury by preventing the modulatory effect of hepatic DCs on T cells, especially type 1 T helper effector cells. Thus, hepatic DCs are strongly involved in the promotion of CD4 + T-cell-dependent postischemic liver inflammation.-Funken, D., Ishikawa-Ankerhold, H., Uhl, B., Lerchenberger, M., Rentsch, M., Mayr, D., Massberg, S., Werner, J

The role of cDC1s in vivo: CD8 T cell priming through cross-presentation [version 1; referees: 3 approved

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Derek Theisen

2017-02-01

Full Text Available The cDC1 subset of classical dendritic cells is specialized for priming CD8 T cell responses through the process of cross-presentation. The molecular mechanisms of cross-presentation remain incompletely understood because of limited biochemical analysis of rare cDC1 cells, difficulty in their genetic manipulation, and reliance on in vitro systems based on monocyte- and bone-marrow-derived dendritic cells. This review will discuss cross-presentation from the perspective of studies with monocyte- or bone-marrow-derived dendritic cells while highlighting the need for future work examining cDC1 cells. We then discuss the role of cDC1s as a cellular platform to combine antigen processing for class I and class II MHC presentation to allow the integration of “help” from CD4 T cells during priming of CD8 T cell responses.

TLR-4 engagement of dendritic cells confers a BST-2/tetherin-mediated restriction of HIV-1 infection to CD4+ T cells across the virological synapse

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Blanchet Fabien P

2013-01-01

Full Text Available Abstract Background Dendritic cells and their subsets, located at mucosal surfaces, are among the first immune cells to encounter disseminating pathogens. The cellular restriction factor BST-2/tetherin (also known as CD317 or HM1.24 potently restricts HIV-1 release by retaining viral particles at the cell surface in many cell types, including primary cells such as macrophages. However, BST-2/tetherin does not efficiently restrict HIV-1 infection in immature dendritic cells. Results We now report that BST-2/tetherin expression in myeloid (myDC and monocyte-derived dendritic cells (DC can be significantly up-regulated by IFN-α treatment and TLR-4 engagement with LPS. In contrast to HeLa or 293T cells, infectious HIV-1 release in immature DC and IFN-α–matured DC was only modestly affected in the absence of Vpu compared to wild-type viruses. Strikingly, immunofluorescence analysis revealed that BST-2/tetherin was excluded from HIV containing tetraspanin-enriched microdomains (TEMs in both immature DC and IFN-α–matured DC. In contrast, in LPS-mediated mature DC, BST-2/tetherin exerted a significant restriction in transfer of HIV-1 infection to CD4+ T cells. Additionally, LPS, but not IFN-α stimulation of immature DC, leads to a dramatic redistribution of cellular restriction factors to the TEM as well as at the virological synapse between DC and CD4+ T cells. Conclusions In conclusion, we demonstrate that TLR-4 engagement in immature DC significantly up-regulates the intrinsic antiviral activity of BST-2/tetherin, during cis-infection of CD4+ T cells across the DC/T cell virological synapse. Manipulating the function and potency of cellular restriction factors such as BST-2/tetherin to HIV-1 infection, has implications in the design of antiviral therapeutic strategies.

IL-6 inhibits upregulation of membrane-bound TGF-beta 1 on CD4+ T cells and blocking IL-6 enhances oral tolerance

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Kuhn, Chantal; Rezende, Rafael Machado; M'Hamdi, Hanane; da Cunha, Andre Pires; Weiner, Howard L.

2016-01-01

Oral administration of antigen induces regulatory T cells that express latent membrane-bound TGF-beta (LAP) and that have been shown to play an important role in the induction of oral tolerance. We developed an in vitro model to study modulation of LAP+ on CD4+ T cells. The combination of anti-CD3 mAb, anti-CD28 mAb and recombinant IL-2 induced expression of LAP on naïve CD4+ T cells, independent of FoxP3 or exogenous TGF-β. In vitro generated CD4+LAP+FoxP3− T cells were suppressive in vitro, inhibiting proliferation of naïve CD4+ T cells and IL-17A secretion by Th17 cells. Assessing the impact of different cytokines and neutralizing antibodies against cytokines we found that LAP induction was decreased in the presence of IL-6 and IL-21, and to a lesser extent by IL-4 and TNFα. IL-6 abrogated the in vitro induction of CD4+LAP+ T cells by STAT3 dependent inhibition of Lrrc32 (GARP), the adapter protein that tethers TGF-beta to the membrane. Oral tolerance induction was enhanced in mice lacking expression of IL-6R by CD4+ T cells and by treatment of wild-type mice with neutralizing anti-IL-6 mAb. These results suggest that pro-inflammatory cytokines interfere with oral tolerance induction and that blocking the IL-6 pathway is a potential strategy for enhancing oral tolerance in the setting of autoimmune and inflammatory diseases. PMID:28039301

Conglutinin binds the HIV-1 envelope glycoprotein gp 160 and inhibits its interaction with cell membrane CD4

DEFF Research Database (Denmark)

Andersen, Ove; Sørensen, A M; Svehag, S E

1991-01-01

The highly glycosylated envelope glycoprotein (gp 160) of human immunodeficiency virus (HIV) interacts with the CD4 molecule present on the membrane of CD4+ cells and is involved in the pathobiology of HIV infection. Lectins bind glycoproteins through non-covalent interactions with specific hexose...... residues. The mammalian C-type lectin bovine conglutinin was examined for its ability to interact with recombinant gp160 (rgp160) produced in vaccinia virus-infected BHK21 cells. Specific binding of conglutinin to rgp160 was demonstrated by ELISA. The interaction of bovine conglutinin with rgp160...... of the binding of rgp160 to the CD4 receptor on CEM 13 cells, as demonstrated by FACS analyses. These results indicate that conglutinin may inhibit the infection with HIV-1 through its interaction with the viral envelope glycoprotein....

Reprogramming tumor-infiltrating dendritic cells for CD103+CD8+ mucosal T cell differentiation and breast cancer rejection

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Wu, Te-Chia; Xu, Kangling; Banchereau, Romain; Marches, Florentina; Yu, Chun I; Martinek, Jan; Anguiano, Esperanza; Pedroza-Gonzalez, Alexander; Snipes, G. Jackson; O’Shaughnessy, Joyce; Nishimura, Stephen; Liu, Yong-Jun; Pascual, Virginia; Banchereau, Jacques; Oh, Sangkon; Palucka, Karolina

2014-01-01

Our studies showed that tumor-infiltrating dendritic cells (DC) in breast cancer drive inflammatory T helper 2 (iTh2) cells and protumor inflammation. Here we show that intratumoral delivery of the β-glucan curdlan, a ligand of dectin-1, blocks the generation of iTh2 cells, and prevents breast cancer progression in vivo. Curdlan reprograms tumor-infiltrating DC via the ligation of dectin-1, enabling the DC to become resistant to cancer-derived thymic stromal lymphopoietin (TSLP), to produce IL12p70, and to favor the generation of T helper 1 (Th1) cells. DC activated via dectin-1, but not those activated with TLR-7/8 ligand or poly IC, induce CD8+ T cells to express CD103 (αE integrin), a ligand for cancer cells E-cadherin. Generation of these mucosal CD8+ T cells is regulated by DC-derived integrin αvβ8 and TGF-β activation in a dectin-1-dependent fashion. These CD103+CD8+ mucosal T cells accumulate in the tumors thereby increasing cancer necrosis and inhibiting cancer progression in vivo in a humanized mouse model of breast cancer. Importantly, CD103+CD8+ mucosal T cells elicited by reprogrammed DC can reject established cancer. Thus, reprogramming tumor-infiltrating DC represents a new strategy for cancer rejection. PMID:24795361

IL-6 Inhibits Upregulation of Membrane-Bound TGF-β 1 on CD4+ T Cells and Blocking IL-6 Enhances Oral Tolerance.

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Kuhn, Chantal; Rezende, Rafael Machado; M'Hamdi, Hanane; da Cunha, Andre Pires; Weiner, Howard L

2017-02-01

Oral administration of Ag induces regulatory T cells that express latent membrane-bound TGF-β (latency-associated peptide [LAP]) and have been shown to play an important role in the induction of oral tolerance. We developed an in vitro model to study modulation of LAP + on CD4 + T cells. The combination of anti-CD3 mAb, anti-CD28 mAb, and recombinant IL-2 induced expression of LAP on naive CD4 + T cells, independent of Foxp3 or exogenous TGF-β. In vitro generated CD4 + LAP + Foxp3 - T cells were suppressive in vitro, inhibiting proliferation of naive CD4 + T cells and IL-17A secretion by Th17 cells. Assessing the impact of different cytokines and neutralizing Abs against cytokines, we found that LAP induction was decreased in the presence of IL-6 and IL-21, and to a lesser extent by IL-4 and TNF-α. IL-6 abrogated the in vitro induction of CD4 + LAP + T cells by STAT3-dependent inhibition of Lrrc32 (glycoprotein A repetitions predominant [GARP]), the adapter protein that tethers TGF-β to the membrane. Oral tolerance induction was enhanced in mice lacking expression of IL-6R by CD4 + T cells and by treatment of wild-type mice with neutralizing anti-IL-6 mAb. These results suggest that proinflammatory cytokines interfere with oral tolerance induction and that blocking the IL-6 pathway is a potential strategy for enhancing oral tolerance in the setting of autoimmune and inflammatory diseases. Copyright © 2017 by The American Association of Immunologists, Inc.

A novel kefir product (PFT) activates dendritic cells to induce CD4+T and CD8+T cell responses in vitro.

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Ghoneum, Mamdooh; Felo, Nouran; Agrawal, Sudhanshu; Agrawal, Anshu

2015-12-01

Lactobacilli have been widely studied for their probiotic effects and have been reported to function as antiviral and anticancer agents. However, the underlying mechanisms via immune modulation are poorly understood. PFT is a freeze dried compound of Lactobacillus kefiri P-IF with a unique composition and functionality. In this study, we examined the potential stimulatory effects of two concentrations (50 µg and 100 µg/mL) of PFT on human monocyte-derived dendritic cell (DC) function in vitro. Results showed that PFT upregulated the expression of DC surface co-stimulatory and maturation markers CD80, CD86, and HLADR in a concentration dependent manner. PFT at 100 µg/mL markedly increased the secretion of IL-6, IL-10, TNF-α, and IL-1β by DCs. This concentration of PFT also stimulated the production of antiviral cytokines, IFN-α and IFN-λ(IL29) in DCs. Additionally, PFT at 100 µg/mL activated moDCs prime CD4(+)T cells and significantly increased the levels of IL-10, IFN-γ, and TNF-α by 1.7, four, three-fold, respectively. Furthermore PFT-stimulated DCs were also effective in enhancing the cytotoxic potential of CD8(+)T cells via the induction of Granzyme-B and upregulation of CD107a, and CD103 expression, a marker of resident/regulatory CD8(+)T cells. These data suggest that PFT functions as a natural adjuvant for DC activation and thus may be used in DC-based vaccine strategies against viral infections and cancer. © The Author(s) 2015.

CD4+ Primary T Cells Expressing HCV-Core Protein Upregulate Foxp3 and IL-10, Suppressing CD4 and CD8 T Cells

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Aguado, Enrique; Garcia-Cozar, Francisco

2014-01-01

Adaptive T cell responses are critical for controlling HCV infection. While there is clinical evidence of a relevant role for regulatory T cells in chronic HCV-infected patients, based on their increased number and function; mechanisms underlying such a phenomena are still poorly understood. Accumulating evidence suggests that proteins from Hepatitis C virus can suppress host immune responses. We and others have shown that HCV is present in CD4+ lymphocytes from chronically infected patients and that HCV-core protein induces a state of unresponsiveness in the CD4+ tumor cell line Jurkat. Here we show that CD4+ primary T cells lentivirally transduced with HCV-core, not only acquire an anergic phenotype but also inhibit IL-2 production and proliferation of bystander CD4+ or CD8+ T cells in response to anti-CD3 plus anti-CD28 stimulation. Core-transduced CD4+ T cells show a phenotype characterized by an increased basal secretion of the regulatory cytokine IL-10, a decreased IFN-γ production upon stimulation, as well as expression of regulatory T cell markers, CTLA-4, and Foxp3. A significant induction of CD4+CD25+CD127lowPD-1highTIM-3high regulatory T cells with an exhausted phenotype was also observed. Moreover, CCR7 expression decreased in HCV-core expressing CD4+ T cells explaining their sequestration in inflamed tissues such as the infected liver. This work provides a new perspective on de novo generation of regulatory CD4+ T cells in the periphery, induced by the expression of a single viral protein. PMID:24465502

CD4+ primary T cells expressing HCV-core protein upregulate Foxp3 and IL-10, suppressing CD4 and CD8 T cells.

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Cecilia Fernandez-Ponce

Full Text Available Adaptive T cell responses are critical for controlling HCV infection. While there is clinical evidence of a relevant role for regulatory T cells in chronic HCV-infected patients, based on their increased number and function; mechanisms underlying such a phenomena are still poorly understood. Accumulating evidence suggests that proteins from Hepatitis C virus can suppress host immune responses. We and others have shown that HCV is present in CD4+ lymphocytes from chronically infected patients and that HCV-core protein induces a state of unresponsiveness in the CD4+ tumor cell line Jurkat. Here we show that CD4+ primary T cells lentivirally transduced with HCV-core, not only acquire an anergic phenotype but also inhibit IL-2 production and proliferation of bystander CD4+ or CD8+ T cells in response to anti-CD3 plus anti-CD28 stimulation. Core-transduced CD4+ T cells show a phenotype characterized by an increased basal secretion of the regulatory cytokine IL-10, a decreased IFN-γ production upon stimulation, as well as expression of regulatory T cell markers, CTLA-4, and Foxp3. A significant induction of CD4+CD25+CD127(lowPD-1(highTIM-3(high regulatory T cells with an exhausted phenotype was also observed. Moreover, CCR7 expression decreased in HCV-core expressing CD4+ T cells explaining their sequestration in inflamed tissues such as the infected liver. This work provides a new perspective on de novo generation of regulatory CD4+ T cells in the periphery, induced by the expression of a single viral protein.

Luteolin, a flavonoid, inhibits CD40 ligand expression by activated human basophils.

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Hirano, Toru; Arimitsu, Junsuke; Higa, Shinji; Naka, Tetsuji; Ogata, Atsushi; Shima, Yoshihito; Fujimoto, Minoru; Yamadori, Tomoki; Ohkawara, Tomoharu; Kuwabara, Yusuke; Kawai, Mari; Kawase, Ichiro; Tanaka, Toshio

2006-01-01

We have previously shown that flavonoids such as luteolin, apigenin and fisetin inhibit interleukin 4 and interleukin 13 production. In this study, we investigated whether luteolin can suppress CD40 ligand expression by basophils. A human basophilic cell line, KU812, was stimulated with A23187 and phorbol myristate acetate (PMA) with or without various concentrations of luteolin or other flavonoids for 12 h, and CD40 ligand expression was analyzed by FACS. The effect of luteolin on CD40 ligand mRNA expression was studied by semiquantitative reverse transcription PCR analysis. In addition, CD40 ligand expression was also measured in purified basophils that had been stimulated for 12 h with A23187 plus PMA with or without various concentrations of luteolin. CD40 ligand expression by KU812 cells was enhanced noticeably in response to A23187 and even more strikingly augmented by A23187 plus PMA. The expression was significantly suppressed by 10 or 30 microM of luteolin, whereas myricetin failed to inhibit. Reverse transcription PCR analyses demonstrated that luteolin inhibited CD40 ligand mRNA expression by stimulated KU812 cells. Of the six flavonoids examined, luteolin, apigenin, fisetin and quercetin at 30 microM showed a significant inhibitory effect on CD40 ligand expression. The incubation of purified basophils with A23187 plus PMA significantly enhanced CD40 ligand expression, and the presence of luteolin again had an inhibitory effect. Luteolin inhibits CD40 ligand expression by activated basophils.

Lewis Lung Cancer Cells Promote SIGNR1(CD209b)-Mediated Macrophages Polarization Induced by IL-4 to Facilitate Immune Evasion.

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Yan, Xiaolong; Li, Wenhai; Pan, Lei; Fu, Enqing; Xie, Yonghong; Chen, Min; Mu, Deguang

2016-05-01

Tumor-associated macrophages are a prominent component of lung cancer and contribute to tumor progression by facilitating the immune evasion of cancer cells. DC-SIGN (CD209) assists in the immune evasion of a broad spectrum of pathogens and neoplasms by inhibiting the maturation of DCs and subsequent cytokines production. However, the expression of DC-SIGN in macrophages and its role in mediating immune evasion in lung cancer and the underlying mechanism remain unclear. Our study aimed to identify the immunosuppressive role of SIGNR1 in murine macrophage differentiation and lung cancer progression. We found that SIGNR1-positive RAW264.7 macrophages were enriched in mixed cultures with Lewis lung cancer cells (LLC) (ratio of RAW 264.7 to LLC being 1:1) after stimulation with IL-4. Moreover, LLC-educated macrophages exhibited significantly higher levels of IL-10 but lower IL-12 in response to IL-4 treatment as determined by RT-PCR and ELISA. However, inhibition of SIGNR1 markedly hampered the production of IL-10, indicating that SIGNR1 was indispensable for IL-4+LLC induced macrophage polarization towards the M2 subtype. Furthermore, polarized M2 cells immersed in a tumor microenvironment promoted the migration of LLCs, as measured by transwell assays, but migration was suppressed after blockade of SIGNR1 using CD209b antibody. In addition, IL-4+LLC-educated macrophages reduced the proliferation of the activated T cells and reduced IFN-γ-mediated Th1 response in T cells, while SIGNR1 inhibition rescued Th1 cell functions. In conclusion, murine SIGNR1 expressed in LLC-educated macrophages appears to mediate IL-4-induced RAW264.7 macrophage polarization and thus facilitate lung cancer evasion. © 2015 Wiley Periodicals, Inc.

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

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Muhaimin Rifa’i

2014-05-01

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

Hormonal Contraceptives Differentially Suppress TFV and TAF Inhibition of HIV Infection and TFV-DP in Blood and Genital Tract CD4+ T cells.

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Shen, Zheng; Rodriguez-Garcia, Marta; Patel, Mickey V; Bodwell, Jack; Kashuba, Angela D M; Wira, Charles R

2017-12-18

HIV prevention research is focused on combining antiretrovirals (ARV) and progestin contraceptives to prevent HIV infection and pregnancy. The possibility that progestins compromise ARV anti-HIV activity prompted us to evaluate the effects of progestins on tenofovir (TFV) and TFV-alafenamide (TAF) on HIV infection and intracellular TFV-diphosphate (TFV-DP) concentrations in blood and genital CD4+ T cells. Following incubation of blood CD4+ T cells with TFV or TAF, Medroxyprogesterone acetate (MPA), but not Levonorgestrel, Norethisterone or progesterone, suppressed the anti-HIV effect of TFV by reducing intracellular TFV-DP, but had no effect on TAF inhibition of infection or TFV-DP. In contrast, with genital CD4+ T cells, MPA suppressed TAF inhibition of HIV infection and lowered of TFV-DP concentrations without affecting TFV protection. These findings demonstrate that MPA selectively compromises TFV and TAF protection in blood and genital CD4+ T cells and suggests that MPA may decrease ARV protection in individuals who use ARV intermittently for prevention.

A viral long terminal repeat expressed in CD4+CD8+ precursors is downregulated in mature peripheral CD4-CD8+ or CD4+CD8- T cells.

OpenAIRE

Paquette, Y; Doyon, L; Laperrière, A; Hanna, Z; Ball, J; Sekaly, R P; Jolicoeur, P

1992-01-01

The long terminal repeat from a thymotropic mouse mammary tumor virus variant, DMBA-LV, was used to drive the expression of two reporter genes, murine c-myc and human CD4, in transgenic mice. Expression was observed specifically in thymic immature cells. Expression of c-myc in these cells induced oligoclonal CD4+ CD8+ T-cell thymomas. Expression of human CD4 was restricted to thymic progenitor CD4- CD8- and CD4+ CD8+ T cells and was shut off in mature CD4+ CD8- and CD4- CD8+ T cells, known to...

Friends not foes: CTLA-4 blockade and mTOR inhibition cooperate during CD8+ T cell priming to promote memory formation and metabolic readiness.

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Pedicord, Virginia A; Cross, Justin R; Montalvo-Ortiz, Welby; Miller, Martin L; Allison, James P

2015-03-01

During primary Ag encounter, T cells receive numerous positive and negative signals that control their proliferation, function, and differentiation, but how these signals are integrated to modulate T cell memory has not been fully characterized. In these studies, we demonstrate that combining seemingly opposite signals, CTLA-4 blockade and rapamycin-mediated mammalian target of rapamycin inhibition, during in vivo T cell priming leads to both an increase in the frequency of memory CD8(+) T cells and improved memory responses to tumors and bacterial challenges. This enhanced efficacy corresponds to increased early expansion and memory precursor differentiation of CD8(+) T cells and increased mitochondrial biogenesis and spare respiratory capacity in memory CD8(+) T cells in mice treated with anti-CTLA-4 and rapamycin during immunization. Collectively, these results reveal that mammalian target of rapamycin inhibition cooperates with rather than antagonizes blockade of CTLA-4, promoting unrestrained effector function and proliferation, and an optimal metabolic program for CD8(+) T cell memory. Copyright © 2015 by The American Association of Immunologists, Inc.

Gallic Acid Is the Major Active Component of Cortex Moutan in Inhibiting Immune Maturation of Human Monocyte-Derived Dendritic Cells

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Ben Chung Lap Chan

2015-09-01

Full Text Available Atopic dermatitis (AD is a widely prevalent and chronically relapsing inflammatory skin disease. Penta Herbs Formula (PHF is efficacious in improving the quality of life and reducing topical corticosteroid used in children with AD and one of the active herbs it contains is Cortex Moutan. Recent studies showed that altered functions of dendritic cells (DC were observed in atopic individuals, suggesting that DC might play a major role in the generation and maintenance of inflammation by their production of pro-inflammatory cytokines. Hence, the aims of the present study were to identify the major active component(s of Cortex Moutan, which might inhibit DC functions and to investigate their possible interactions with conventional corticosteroid on inhibiting the development of DC from monocytes. Monocyte-derived dendritic cells (moDC culture model coupled with the high-speed counter-current chromatography (HSCCC, high pressure liquid chromatography (HPLC and Liquid Chromatography-Mass Spectrometry (LCMS analyses were used. Gallic acid was the major active component from Cortex Moutan which could dose dependently inhibit interleukin (IL-12 p40 and the functional cluster of differentiation (CD surface markers CD40, CD80, CD83 and CD86 expression from cytokine cocktail-activated moDC. Gallic acid could also lower the concentration of hydrocortisone required to inhibit the activation of DC.

Downregulation of IL-12 and a novel negative feedback system mediated by CD25+CD4+ T cells

International Nuclear Information System (INIS)

Sato, Kojiro; Tateishi, Shoko; Kubo, Kanae; Mimura, Toshihide; Yamamoto, Kazuhiko; Kanda, Hiroko

2005-01-01

CD25 + CD4 + regulatory T cells suppress immune responses and are believed to play roles in preventing autoimmune diseases. However, the mechanism(s) underlying the suppression and the regulation of their homeostasis remain to be elucidated. Here we show that these regulatory T cells downregulated CD25 - CD4 + T-cell-mediated production of IL-12 from antigen-presenting cells, which can act as a growth factor for CD25 - CD4 + T cells. We further found that CD25 + CD4 + T cells, despite their well-documented 'anergic' nature, proliferate significantly in vitro only when CD25 - CD4 + T cells are present. Notably, this proliferation was strongly dependent on IL-2 and relatively independent of IL-12. Thus, CD25 + CD4 + T cells suppress CD25 - CD4 + T-cell responses, at least in part, by inhibiting IL-12 production while they themselves can undergo proliferation with the mediation of CD25 - CD4 + T cells in vitro. These results offer a novel negative feedback system involving a tripartite interaction among CD25 + CD4 + and CD25 - CD4 + T cells, and APCs that may contribute to the termination of immune responses

Envelope conformational changes induced by human immunodeficiency virus type 1 attachment inhibitors prevent CD4 binding and downstream entry events.

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Ho, Hsu-Tso; Fan, Li; Nowicka-Sans, Beata; McAuliffe, Brian; Li, Chang-Ben; Yamanaka, Gregory; Zhou, Nannan; Fang, Hua; Dicker, Ira; Dalterio, Richard; Gong, Yi-Fei; Wang, Tao; Yin, Zhiwei; Ueda, Yasutsugu; Matiskella, John; Kadow, John; Clapham, Paul; Robinson, James; Colonno, Richard; Lin, Pin-Fang

2006-04-01

BMS-488043 is a small-molecule human immunodeficiency virus type 1 (HIV-1) CD4 attachment inhibitor with demonstrated clinical efficacy. The compound inhibits soluble CD4 (sCD4) binding to the 11 distinct HIV envelope gp120 proteins surveyed. Binding of BMS-488043 and that of sCD4 to gp120 are mutually exclusive, since increased concentrations of one can completely block the binding of the other without affecting the maximal gp120 binding capacity. Similarly, BMS-488043 inhibited virion envelope trimers from binding to sCD4-immunoglobulin G (IgG), with decreasing inhibition as the sCD4-IgG concentration increased, and BMS-488043 blocked the sCD4-induced exposure of the gp41 groove in virions. In both virion binding assays, BMS-488043 was active only when added prior to sCD4. Collectively, these results indicate that obstruction of gp120-sCD4 interactions is the primary inhibition mechanism of this compound and that compound interaction with envelope must precede CD4 binding. By three independent approaches, BMS-488043 was further shown to induce conformational changes within gp120 in both the CD4 and CCR5 binding regions. These changes likely prevent gp120-CD4 interactions and downstream entry events. However, BMS-488043 could only partially inhibit CD4 binding to an HIV variant containing a specific envelope truncation and altered gp120 conformation, despite effectively inhibiting the pseudotyped virus infection. Taken together, BMS-488043 inhibits viral entry primarily through altering the envelope conformation and preventing CD4 binding, and other downstream entry events could also be inhibited as a result of these induced conformational changes.

DC-SIGN (CD209), pentraxin 3 and vitamin D receptor gene variants associate with pulmonary tuberculosis risk in West Africans

DEFF Research Database (Denmark)

Olesen, R; Wejse, C; Velez, D R

2007-01-01

We investigated the role of DC-SIGN (CD209), long pentraxin 3 (PTX3) and vitamin D receptor (VDR) gene single nucleotide polymorphisms (SNPs) in susceptibility to pulmonary tuberculosis (TB) in 321 TB cases and 347 healthy controls from Guinea-Bissau. Five additional, functionally relevant SNPs...... within toll-like receptors (TLRs) 2, 4 and 9 were typed but found, when polymorphic, not to affect host vulnerability to pulmonary TB. We did not replicate an association between SNPs in the DC-SIGN promoter and TB. However, we found that two polymorphisms, one in DC-SIGN and one in VDR, were associated...

Tiamulin inhibits breast cancer growth and pulmonary metastasis by decreasing the activity of CD73.

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Yang, Xu; Pei, Shimin; Wang, Huanan; Jin, Yipeng; Yu, Fang; Zhou, Bin; Zhang, Hong; Zhang, Di; Lin, Degui

2017-04-11

Metastasis is the leading cause of death in breast cancer patients. CD73, also known as ecto-5'-nucleotidase, plays a critical role in cancer development including metastasis. The existing researches indicate that overexpression of CD73 promotes growth and metastasis of breast cancer. Therefore, CD73 inhibitor can offer a promising treatment for breast cancer. Here, we determined whether tiamulin, which was found to inhibit CD73, was able to suppress breast cancer development and explored the related mechanisms. We firstly measured the effect of tiamulin hydrogen fumarate (THF) on CD73 using high performance liquid chromatography (HPLC). Then, we investigated cell proliferation, migration and invasion in MDA-MB-231 human breast cancer cell line and 4 T1 mouse breast cancer cell line treated with THF by migration assay, invasion assay and activity assay. Besides, we examined the effect of THF on syngeneic mammary tumors of mice by immunohistochemistry. Our data demonstrated that THF inhibited CD73 by decreasing the activity instead of the expression of CD73. In vitro, THF inhibited the proliferation, migration and invasion of MDA-MB-231 and 4 T1 cells by suppressing CD73 activity. In vivo, animal experiments showed that THF treatment resulted in significant reduction in syngeneic tumor growth, microvascular density and lung metastasis rate. Our results indicate that THF inhibits growth and metastasis of breast cancer by blocking the activity of CD73, which may offer a promising treatment for breast cancer therapy.

Inhibition of dipeptidyl peptidase 4 regulates microvascular endothelial growth induced by inflammatory cytokines

International Nuclear Information System (INIS)

Takasawa, Wataru; Ohnuma, Kei; Hatano, Ryo; Endo, Yuko; Dang, Nam H.; Morimoto, Chikao

2010-01-01

Research highlights: → TNF-α or IL-1β induces EC proliferation with reduction of CD26 expression. → CD26 siRNA or DPP-4 inhibition enhances TNF-α or IL-1β-induced EC proliferation. → Loss of CD26/DPP-4 enhances aortic sprouting induced by TNF-α or IL-1β. → Capillary formation induced by TNF-α or IL-1β is enahced in the CD26 -/- mice. -- Abstract: CD26/DPP-4 is abundantly expressed on capillary of inflamed lesion as well as effector T cells. Recently, CD26/dipeptidyl peptidase 4 (DPP-4) inhibition has been used as a novel oral therapeutic approach for patients with type 2 diabetes. While accumulating data indicate that vascular inflammation is a key feature of both micro- and macro-vascular complications in diabetes, the direct role of CD26/DPP-4 in endothelial biology is to be elucidated. We herein showed that proinflammatory cytokines such as tumor necrosis factor or interleukin-1 reduce expression of CD26 on microvascular endothelial cells, and that genetical or pharmacological inhibition of CD26/DPP-4 enhances endothelial growth both in vitro and in vivo. With DPP-4 inhibitors being used widely in the treatment of type 2 diabetes, our data strongly suggest that DPP-4 inhibition plays a pivotal role in endothelial growth and may have a potential role in the recovery of local circulation following diabetic vascular complications.

Imprinting of CCR9 on CD4 T cells requires IL-4 signaling on mesenteric lymph node dendritic cells.

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Elgueta, Raul; Sepulveda, Fernando E; Vilches, Felipe; Vargas, Leonardo; Mora, J Rodrigo; Bono, Maria Rosa; Rosemblatt, Mario

2008-05-15

It has recently been shown that IL-4 can educate dendritic cells (DC) to differentially affect T cell effector activity. In this study, we show that IL-4 can also act upon DC to instruct naive T cells to express the gut-associated homing receptor CCR9. Thus, effector T cells generated after coculture with mesenteric lymph node (MLN)-DC show a higher expression of CCR9 when activated in the presence of IL-4. In contrast, IL-4 had no effect on CCR9 expression when naive T cells were polyclonally activated in the absence of MLN-DC, suggesting that the effect of IL-4 on CCR9 expression passed through DC. Indeed, T cells activated by MLN-DC from IL-4Ralpha(-/-) mice showed a much lower CCR9 expression and a greatly reduced migration to the small intestine than T cells activated by wild-type MLN-DC even in the presence of IL-4. Consistent with the finding that the vitamin A metabolite retinoic acid (RA) induces gut-homing molecules on T cells, we further demonstrate that IL-4 up-regulated retinaldehyde dehydrogenase 2 mRNA on MLN-DC, a critical enzyme involved in the synthesis of RA. Moreover, LE135, a RA receptor antagonist, blocked the increased expression of CCR9 driven by IL-4-treated MLN-DC. Thus, besides the direct effect of RA on T cell gut tropism, our results show that the induction of a gut-homing phenotype on CD4(+) T cells is also influenced by the effect of IL-4 on gut-associated DC.

Drilling history core hole DC-4

International Nuclear Information System (INIS)

1978-12-01

Core hole DC-4 was completed at a depth of 3998 feet in December, 1978 by Boyles Brothers Drilling Company, Spokane, Washington, under subcontract to Fenix and Scission, Inc. The hole was cored for the US Department of Energy and the Rockwell Hanford Operations' Basalt Waste Isolation Program. Fenix and Sicsson, Inc. furnished the engineering, daily supervision of the cable tool and core drilling activities, and geological core logging for DC-4. Core hole DC-4 is located on the Hanford Site about 3 miles east of the Yakima Barricade and approximately 103 feet southwest of rotary hole DC-5, which was completed to 3990 feet in February, 1978. Hanford Site coordinates reported for hole DC-4 are north 49,385.62 feet and west 85,207.63 feet, and Washington State coordinates are north 454,468.73 feet and east 2,209,990.87 feet. No elevation survey is available for hole DC-4, but it is approximately 745 feet above mean sea level based upon the survey of hole DC-5, which has a reported elevation of 745.16 feet on the top of the 3-inch flange. The purpose of core hole DC-4 was to core drill vertically through the basalt and interbed units for stratigraphic depth determination and core collection, and to provide a borehole for hydrologic testing, cross-hole seismic shear, and pressure wave velocity studies with rotary hole DC-5. Hole DC-4 was drilled through the overburden into basalt bedrock by cable tool methods (0-623 feet) and continuously cored through the final interval (623 to 3998 feet).Core recovery was 95.8 percent of the total footage cored

Total glucosides of paeony induces regulatory CD4(+)CD25(+) T cells by increasing Foxp3 demethylation in lupus CD4(+) T cells.

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Zhao, Ming; Liang, Gong-ping; Tang, Mei-ni; Luo, Shuang-yan; Zhang, Jing; Cheng, Wen-jing; Chan, Tak-mao; Lu, Qian-jin

2012-05-01

Total glucosides of paeony (TGP), an active compound extracted from Paeony root, has been used in therapy for autoimmune diseases. However the molecular mechanism of TGP in the prevention of autoimmune response remains unclear. In this study, we found that TGP treatment significantly increased the percentage and number of Treg cells in lupus CD4(+) T cells. Further investigation revealed that treatment with TGP increased the expression of Foxp3 in lupus CD4(+) T cells by down-regulating Foxp3 promoter methylation levels. However, we couldn't observe similar results in healthy control CD4(+) T cells treated by TGP. Moreover, our results also showed that IFN-γ and IL-2 expression was enhanced in TGP-treated lupus CD4(+) T cells. These findings indicate that TGP inhibits autoimmunity in SLE patients possibly by inducing Treg cell differentiation, which may in turn be due to its ability to regulate the methylation status of the Foxp3 promoter and activate IFN-γ and IL-2 signaling. Copyright © 2012 Elsevier Inc. All rights reserved.

Uncarinic Acid C Isolated from Uncaria rhynchophylla Induces Differentiation of Th1-Promoting Dendritic Cells Through TLR4 Signaling.

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Kim, Kyu Sik; Pham, Thanh Nhan Nguyen; Jin, Chun-Ji; Umeyama, Akemi; Shoji, Noboru; Hashimoto, Toshihiro; Lee, Je-Jung; Takei, Masao

2011-02-28

Uncarinic acid C (URC) is triterpene isolated from Uncaria rhynchophylla and is a pharmacologically active substance. The induction of dendritic cells (DC) is critical for the induction of Ag-specific T lymphocyte responses and may be essential for the development of human vaccines relying on T cell immunity. DC might be a potential target for URC. We demonstrate that URC activates human DC as documented by phenotypic and functional maturation, and altered cytokine production. The expression of CD1a, CD38, CD40, CD54, CD80, CD83, CD86, HLA-DR and CCR7 on URC-primed DC was enhanced. The production of IL-12p70 by URC-primed DC was higher than that of lipopolysaccharide (LPS)-primed DC. The production of IL-12p70 by URC-primed DC was inhibited by the anti-Toll-like receptor 4 (TLR4) monoclonal antibody (mAb), but partially abolished by anti-TLR2 mAb. mRNA coding for TLR2 and TLR4 was expressed in URC-primed DC. URC-primed DC induced the NF-κB transcription factor. Naïve T cells co-cultured with URC-primed DC turned into typical Th1 cells that produced large quantities of IFN-γ depending on IL-12 secretion. URC enhanced the T cell stimulatory capacity in an allo MLR. In the cytotoxic T-lymphocyte assay (CTL) assay, DNA fragmentation assay and (51)Cr release on URC-primed DC were more augmented than that of TNF-α-primed DC. DC matured with URC had an intermediate migratory capacity towards CCL19 and CCL21. These results suggest that URC modulates DC function in a fashion that favors Th1 polarization via the activation of IL-12p70 dependent on TLR4 signaling, and may be used on DC-based vaccine for cancer immunotherapy.

Differential requirements of CD4(+) T-cell signals for effector cytotoxic T-lymphocyte (CTL) priming and functional memory CTL development at higher CD8(+) T-cell precursor frequency.

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Umeshappa, Channakeshava S; Nanjundappa, Roopa H; Xie, Yufeng; Freywald, Andrew; Xu, Qingyong; Xiang, Jim

2013-04-01

Increased CD8(+) T-cell precursor frequency (PF) precludes the requirement of CD4(+) helper T (Th) cells for primary CD8(+) cytotoxic T-lymphocyte (CTL) responses. However, the key questions of whether unhelped CTLs generated at higher PF are functional effectors, and whether unhelped CTLs can differentiate into functional memory cells at higher PF are unclear. In this study, ovalbumin (OVA) -pulsed dendritic cells (DC(OVA)) derived from C57BL/6, CD40 knockout (CD40(-/-)) or CD40 ligand knockout (CD40L(-/-)) mice were used to immunize C57BL/6, Ia(b-/-), CD40(-/-) or CD40L(-/-) mice, whose PF was previously increased with transfer of 1 × 10(6) CD8(+) T cells derived from OVA-specific T-cell receptor (TCR) transgenic OTI, OTI(CD40(-/-)) or OTI(CD40L(-/-)) mice. All the immunized mice were then assessed for effector and memory CTL responses. Following DC immunization, relatively comparable CTL priming occurred without CD4(+) T-cell help and Th-provided CD40/CD40L signalling. In addition, the unhelped CTLs were functional effectors capable of inducing therapeutic immunity against established OVA-expressing tumours. In contrast, the functional memory development of CTLs was severely impaired in the absence of CD4(+) T-cell help and CD40/CD40L signalling. Finally, unhelped memory CTLs failed to protect mice against lethal tumour challenge. Taken together, these results demonstrate that CD4(+) T-cell help at higher PF, is not required for effector CTL priming, but is required for functional memory CTL development against cancer. Our data may impact the development of novel preventive and therapeutic approaches in cancer patients with compromised CD4(+) T-cell functions. © 2012 Blackwell Publishing Ltd.

Korelasi Kadar Feritin dengan Jumlah CD4, CD8, dan Rasio CD4/CD8 pada Penyandang Talasemia Mayor Anak

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Bonnie Arseno

2017-11-01

Hasil. Didapatkan jumlah CD4 absolut, CD4%, CD8 absolut dan rasio CD4/CD8 menurun. Selain itu, terdapat jumlah CD4 absolut, CD8 absolut dan CD8% meningkat. Pada kelompok usia ≤5 tahun, korelasi kadar feritin dengan CD8 absolut, CD8%, dan rasio CD4/CD8 berturut-turut menghasilkan koefisien korelasi 0,691, 0,557, -0,680, dan p<0,05. Sementara pada kelompok lama terapi ≤5 tahun korelasi kadar feritin dengan CD8 absolut, CD8%, dan rasio CD4/CD8 menghasilkan koefisien korelasi 0,709, 0,571, -0,726 dengan p<0,05. Kesimpulan. Tidak terdapat korelasi antara kadar feritin dengan jumlah CD4, CD8, rasio CD4/CD8. Peningkatan kadar feritin akan diikuti dengan peningkatan jumlah CD8 absolut dan CD8%, serta penurunan rasio CD4/CD8 pada penyandang talasemia mayor anak berdasar atas usia dan lama terapi ≤5 tahun.

The TRPA1 ion channel is expressed in CD4+ T cells and restrains T-cell-mediated colitis through inhibition of TRPV1.

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Bertin, Samuel; Aoki-Nonaka, Yukari; Lee, Jihyung; de Jong, Petrus R; Kim, Peter; Han, Tiffany; Yu, Timothy; To, Keith; Takahashi, Naoki; Boland, Brigid S; Chang, John T; Ho, Samuel B; Herdman, Scott; Corr, Maripat; Franco, Alessandra; Sharma, Sonia; Dong, Hui; Akopian, Armen N; Raz, Eyal

2017-09-01

Transient receptor potential ankyrin-1 (TRPA1) and transient receptor potential vanilloid-1 (TRPV1) are calcium (Ca 2+ )-permeable ion channels mostly known as pain receptors in sensory neurons. However, growing evidence suggests their crucial involvement in the pathogenesis of IBD. We explored the possible contribution of TRPA1 and TRPV1 to T-cell-mediated colitis. We evaluated the role of Trpa1 gene deletion in two models of experimental colitis (ie, interleukin-10 knockout and T-cell-adoptive transfer models). We performed electrophysiological and Ca 2+ imaging studies to analyse TRPA1 and TRPV1 functions in CD4+ T cells. We used genetic and pharmacological approaches to evaluate TRPV1 contribution to the phenotype of Trpa1 -/- CD4+ T cells. We also analysed TRPA1 and TRPV1 gene expression and TRPA1 + TRPV1 + T cell infiltration in colonic biopsies from patients with IBD. We identified a protective role for TRPA1 in T-cell-mediated colitis. We demonstrated the functional expression of TRPA1 on the plasma membrane of CD4+ T cells and identified that Trpa1 -/- CD4+ T cells have increased T-cell receptor-induced Ca 2+ influx, activation profile and differentiation into Th1-effector cells. This phenotype was abrogated upon genetic deletion or pharmacological inhibition of the TRPV1 channel in mouse and human CD4+ T cells. Finally, we found differential regulation of TRPA1 and TRPV1 gene expression as well as increased infiltration of TRPA1 + TRPV1 + T cells in the colon of patients with IBD. Our study indicates that TRPA1 inhibits TRPV1 channel activity in CD4+ T cells, and consequently restrains CD4+ T-cell activation and colitogenic responses. These findings may therefore have therapeutic implications for human IBD. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Enhanced Dendritic Cell-Mediated Antigen-Specific CD4+ T Cell Responses: IFN-Gamma Aids TLR Stimulation

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Kuo-Ching Sheng

2013-01-01

Full Text Available Phenotypic maturation and T cell stimulation are two functional attributes of DCs critical for immune induction. The combination of antigens, including those from cancer, with Toll-like receptor (TLR ligands induces far superior cellular immune responses compared to antigen alone. In this study, IFN-gamma treatment of bone marrow-derived DC, followed by incubation with the TLR2, TLR4, or TLR9 agonists, enhanced DC activation compared to TLR ligation alone. Most notably, the upregulation of CD40 with LPS stimulation and CD86 with CpG stimulation was observed in in vitro cultures. Similarly, IFN-gamma coinjected with TLR ligands was able to promote DC activation in vivo, with DCs migrating from the site of immunization to the popliteal lymph nodes demonstrating increased expression of CD80 and CD86. The heightened DC activation translated to a drastic increase in T cell stimulatory capacity in both antigen independent and antigen dependent fashions. This is the first time that IFN-gamma has been shown to have a combined effect with TLR ligation to enhance DC activation and function. The results demonstrate the novel use of IFN-gamma together with TLR agonists to enhance antigen-specific T cell responses, for applications in the development of enhanced vaccines and drug targets against diseases including cancer.

Fentanyl Suppresses the Survival of CD4+ T Cells Isolated from Human Umbilical Cord Blood through Inhibition of IKKs-mediated NF-κB Activation.

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Ma, K; Ma, P; Lu, H; Liu, S; Cao, Q

2017-05-01

The aim of this study was to investigate the effects and the underlying mechanisms of fentanyl anaesthetic on T lymphocytes isolated from human umbilical cord blood in vitro. The percentages of CD4 + , CD8 + and regulatory T (Treg) cells in human umbilical cord blood mononuclear cells (UBMC) treated with fentanyl in vitro were analysed by flow cytometry. The levels of cytokines IFN-γ, IL-2, IL-4 and IL-17 secreted by activated CD4 + T cells were measured by ELISA assays. Expressions of MAPK and NF-κB signalling pathway proteins were determined by Western blotting. Effects of fentanyl on IKK and p65 expression promoter activities were analysed by luciferase assay. Fentanyl decreased the percentages and amounts of CD4 + , CD8 + and Foxp3 + Treg T lymphocyte subsets in UBMCs in a dose-dependent manner. Fentanyl inhibited the proliferation and induced apoptosis of activated CD4 + T cells dose dependently. Fentanyl could not reverse the increase of cell proliferation in activated groups to be equivalent with those in inactivated group. Secretions of IFN-γ, IL-2 and IL-4 cytokines were significantly decreased by moderate to high dose of fentanyl compared with controls. No significant differences were observed in protein expressions of MAPK pathway. In addition, fentanyl suppressed the IKKs-mediated activation of NF-κB. This study demonstrates that fentanyl exerts immunosuppressive effects on T lymphocytes obtained from UBMCs. Thus, the clinical application of fentanyl would not only relieve pain caused by surgery but regulate immune responses post-operation possibly through inhibition of IKKs-mediated NF-κB activation. © 2017 The Foundation for the Scandinavian Journal of Immunology.

Methamphetamine inhibits HIV-1 replication in CD4+ T cells by modulating anti-HIV-1 miRNA expression.

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Mantri, Chinmay K; Mantri, Jyoti V; Pandhare, Jui; Dash, Chandravanu

2014-01-01

Methamphetamine is the second most frequently used illicit drug in the United States. Methamphetamine abuse is associated with increased risk of HIV-1 acquisition, higher viral loads, and enhanced HIV-1 pathogenesis. Although a direct link between methamphetamine abuse and HIV-1 pathogenesis remains to be established in patients, methamphetamine has been shown to increase HIV-1 replication in macrophages, dendritic cells, and cells of HIV transgenic mice. Intriguingly, the effects of methamphetamine on HIV-1 replication in human CD4(+) T cells that serve as the primary targets of infection in vivo are not clearly understood. Therefore, we examined HIV-1 replication in primary CD4(+) T cells in the presence of methamphetamine in a dose-dependent manner. Our results demonstrate that methamphetamine had a minimal effect on HIV-1 replication at concentrations of 1 to 50 μmol/L. However, at concentrations >100 μmol/L, it inhibited HIV-1 replication in a dose-dependent manner. We also discovered that methamphetamine up-regulated the cellular anti-HIV-1 microRNAs (miR-125b, miR-150, and miR-28-5p) in CD4(+) T cells. Knockdown experiments illustrated that up-regulation of the anti-HIV miRNAs inhibited HIV-1 replication. These results are contrary to the paradigm that methamphetamine accentuates HIV-1 pathogenesis by increasing HIV-1 replication. Therefore, our findings underline the complex interaction between drug use and HIV-1 and necessitate comprehensive understanding of the effects of methamphetamine on HIV-1 pathogenesis. Copyright © 2014 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

[Regulatory B cells activated by CpG-ODN combined with anti-CD40 monoclonal antibody inhibit CD4(+)T cell proliferation].

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Wang, Keng; Tao, Lei; Su, Jianbing; Zhang, Yueyang; Zou, Binhua; Wang, Yiyuan; Li, Xiaojuan

2016-09-01

Objective To observe the immunosuppressive function of regulatory B cells (Bregs) in vitro after activated by CpG oligodeoxynucleotide (CpG-ODN) and anti-CD40 mAb. Methods Mice splenic CD5(+)CD1d(high)B cells and CD5(-)CD1d(low)B cells were sorted by flow cytometry. These B cells were first stimulated with CpG-ODN combined with anti-CD40 mAb for 24 hours, and then co-cultured with purified CD4(+)T cells. The interleukin 10 (IL-10) expression in the activated Bregs and other B cell subset, as well as the proliferation and interferon γ (IFN-γ) expression in the CD4(+) T cells activated by anti-CD3 mAb plus anti-CD28 mAb were determined by flow cytometry. Results CD5(+)CD1d(high) B cells activated by CpG-ODN plus anti-CD40 mAb blocked the up-regulated CD4(+)T proliferation and significantly reduced the IFN-γ level. At the same time, activated CD5(-)CD1d(low)B cells showed no inhibitory effect on CD4(+)T cells. Further study revealed that IL-10 expression in the CD5(+)CD1d(high) B cells were much higher than that in the CD5(-)CD1d(low)B cells after stimulated with CpG-ODN combined with anti-CD40 mAb for 24 hours. Conclusion CD5(+)CD1d(high) B cells activated by CpG-ODN combined with anti-CD40 mAb have immune inhibitory effects on CD4(+)T cell activation in vitro , which possibly due to IL-10 secretion.

Vaccination of B-CLL patients with autologous dendritic cells can change the frequency of leukemia antigen-specific CD8+ T cells as well as CD4+CD25+FoxP3+ regulatory T cells toward an antileukemia response.

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Hus, I; Schmitt, M; Tabarkiewicz, J; Radej, S; Wojas, K; Bojarska-Junak, A; Schmitt, A; Giannopoulos, K; Dmoszyńska, A; Roliński, J

2008-05-01

Recently, we described that vaccination with allogeneic dendritic cells (DCs) pulsed with tumor cell lysate generated specific CD8+ T cell response in patients with B-cell chronic lymphocytic leukemia (B-CLL). In the present study, the potential of autologous DCs pulsed ex vivo with tumor cell lysates to stimulate antitumor immunity in patients with B-CLL in early stages was evaluated. Twelve patients at clinical stage 0-2 as per Rai were vaccinated intradermally up to eight times with a mean number of 7.4 x 10(6) DCs pulsed with B-CLL cell lysate. We observed a decrease of peripheral blood leukocytes and CD19+/CD5+ leukemic cells in five patients, three patients showed a stable disease and four patients progressed despite DC vaccination. A significant increase of specific cytotoxic CD8+ T lymphocytes against the leukemia-associated antigens RHAMM or fibromodulin was detected in four patients after DC vaccination. In patients with a clinical response, an increase of interleukin 12 (IL-12) serum levels and a decrease of the frequency of CD4+CD25(+)FOXP3+ T regulatory cells were observed. Taken together, the study demonstrated that vaccination with autologous DC in CLL patients is feasible and safe. Immunological and to some extend hematological responses could be noted, justifying further investigation on this immunotherapeutical approach.

A sea urchin lectin, SUL-1, from the Toxopneustid sea urchin induces DC maturation from human monocyte and drives Th1 polarization in vitro

International Nuclear Information System (INIS)

Takei, Masao; Nakagawa, Hideyuki

2006-01-01

The sea urchin Toxopneustes pileolus belonging to the family Toxopneustidae, they have well-developed globiferous pedicellariae with pharmacologically active substances. We have purified a novel sea urchin lectin-1 (SUL-1) from the large globiferous pedicellariae of T. pileolus. Dendritic cells (DC) are professional APC and play a pivotal role in controlling immune responses. This study investigated whether SUL-1 can drive DC maturation from human immature monocyte-derived DC in vitro. Human monocytes were cultured with GM-CSF and IL-4 for 6 days followed by another 1 day in the presence of SUL-1 or LPS. DC harvested on day 7 were examined using functional assays. The expression levels of CD1a, CD80, CD83, CD86 and HLA-DR as expressed by mean fluorescence intensity (MFI) on DC differentiated from immature DC after culture with 1.0 μg/ml of SUL-1 for 1 day were enhanced and decreased endocytic activity. SUL-1-treated DC also displayed enhanced T cell stimulatory capacity in an MLR, as measured by T cell proliferation. Cell surface expression of CD80, CD83 and CD86 on SUL-1-treated DC was inhibited by anti-DC-SIGN mAb, while anti-DC-SIGN mAb had no influence on allogeneic T cell proliferation by SUL-1-treated DC. DC differentiated with SUL-1 induced the differentiation of naive T cell towards a helper T cell type 1 (Th1) response at DC/T (1:5) cells ratio depending on IL-12 secretion. In CTL assay, the production of IFN-γ and 51 Cr release on SUL-1-treated DC were more augmented than of immature DC or LPS-treated DC. SUL-1-treated DC expressed CCR7 and had a high migration to MIP-3β. Intracellular Ca 2+ mobilization in SUL-1-treated DC was also induced by MIP-3β. These results suggest that SUL-1 bindings to DC-SIGN on surface of immature DC may lead to differentiate DC from immature DC. Moreover, it suggests that SUL-1 may be used on DC-based vaccines for cancer immunotherapy

Sphingosine 1-Phosphate- and C-C Chemokine Receptor 2-Dependent Activation of CD4+ Plasmacytoid Dendritic Cells in the Bone Marrow Contributes to Signs of Sepsis-Induced Immunosuppression

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Smirnov, Anna; Pohlmann, Stephanie; Nehring, Melanie; Ali, Shafaqat; Mann-Nüttel, Ritu; Scheu, Stefanie; Antoni, Anne-Charlotte; Hansen, Wiebke; Büettner, Manuela; Gardiasch, Miriam J.; Westendorf, Astrid M.; Wirsdörfer, Florian; Pastille, Eva; Dudda, Marcel; Flohé, Stefanie B.

2017-01-01

Sepsis is the dysregulated response of the host to systemic, mostly bacterial infection, and is associated with an enhanced susceptibility to life-threatening opportunistic infections. During polymicrobial sepsis, dendritic cells (DCs) secrete enhanced levels of interleukin (IL) 10 due to an altered differentiation in the bone marrow and contribute to the development of immunosuppression. We investigated the origin of the altered DC differentiation using murine cecal ligation and puncture (CLP), a model for human polymicrobial sepsis. Bone marrow cells (BMC) were isolated after sham or CLP operation, the cellular composition was analyzed, and bone marrow-derived DCs (BMDCs) were generated in vitro. From 24 h on after CLP, BMC gave rise to BMDC that released enhanced levels of IL-10. In parallel, a population of CD11chiMHCII+CD4+ DCs expanded in the bone marrow in a MyD88-dependent manner. Prior depletion of the CD11chiMHCII+CD4+ DCs from BMC in vitro reversed the increased IL-10 secretion of subsequently differentiating BMDC. The expansion of the CD11chiMHCII+CD4+ DC population in the bone marrow after CLP required the function of sphingosine 1-phosphate receptors and C-C chemokine receptor (CCR) 2, the receptor for C-C chemokine ligand (CCL) 2, but was not associated with monocyte mobilization. CD11chiMHCII+CD4+ DCs were identified as plasmacytoid DCs (pDCs) that had acquired an activated phenotype according to their increased expression of MHC class II and CD86. A redistribution of CD4+ pDCs from MHC class II− to MHC class II+ cells concomitant with enhanced expression of CD11c finally led to the rise in the number of CD11chiMHCII+CD4+ DCs. Enhanced levels of CCL2 were found in the bone marrow of septic mice and the inhibition of CCR2 dampened the expression of CD86 on CD4+ pDCs after CLP in vitro. Depletion of pDCs reversed the bias of splenic DCs toward increased IL-10 synthesis after CLP in vivo. Thus, during polymicrobial sepsis, CD4+ pDCs are activated

Sphingosine 1-Phosphate- and C-C Chemokine Receptor 2-Dependent Activation of CD4+ Plasmacytoid Dendritic Cells in the Bone Marrow Contributes to Signs of Sepsis-Induced Immunosuppression

Directory of Open Access Journals (Sweden)

Anna Smirnov

2017-11-01

Full Text Available Sepsis is the dysregulated response of the host to systemic, mostly bacterial infection, and is associated with an enhanced susceptibility to life-threatening opportunistic infections. During polymicrobial sepsis, dendritic cells (DCs secrete enhanced levels of interleukin (IL 10 due to an altered differentiation in the bone marrow and contribute to the development of immunosuppression. We investigated the origin of the altered DC differentiation using murine cecal ligation and puncture (CLP, a model for human polymicrobial sepsis. Bone marrow cells (BMC were isolated after sham or CLP operation, the cellular composition was analyzed, and bone marrow-derived DCs (BMDCs were generated in vitro. From 24 h on after CLP, BMC gave rise to BMDC that released enhanced levels of IL-10. In parallel, a population of CD11chiMHCII+CD4+ DCs expanded in the bone marrow in a MyD88-dependent manner. Prior depletion of the CD11chiMHCII+CD4+ DCs from BMC in vitro reversed the increased IL-10 secretion of subsequently differentiating BMDC. The expansion of the CD11chiMHCII+CD4+ DC population in the bone marrow after CLP required the function of sphingosine 1-phosphate receptors and C-C chemokine receptor (CCR 2, the receptor for C-C chemokine ligand (CCL 2, but was not associated with monocyte mobilization. CD11chiMHCII+CD4+ DCs were identified as plasmacytoid DCs (pDCs that had acquired an activated phenotype according to their increased expression of MHC class II and CD86. A redistribution of CD4+ pDCs from MHC class II− to MHC class II+ cells concomitant with enhanced expression of CD11c finally led to the rise in the number of CD11chiMHCII+CD4+ DCs. Enhanced levels of CCL2 were found in the bone marrow of septic mice and the inhibition of CCR2 dampened the expression of CD86 on CD4+ pDCs after CLP in vitro. Depletion of pDCs reversed the bias of splenic DCs toward increased IL-10 synthesis after CLP in vivo. Thus, during polymicrobial sepsis, CD4+ pDCs are

S-layer proteins from Lactobacillus sp. inhibit bacterial infection by blockage of DC-SIGN cell receptor.

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Prado Acosta, Mariano; Ruzal, Sandra M; Cordo, Sandra M

2016-11-01

Many species of Lactobacillus sp. possess Surface(s) layer proteins in their envelope. Among other important characteristics S-layer from Lactobacillus acidophilus binds to the cellular receptor DC-SIGN (Dendritic Cell-Specific Intercellular adhesion molecule-3-Grabbing Non-integrin; CD209), which is involved in adhesion and infection of several families of bacteria. In this report we investigate the activity of new S-layer proteins from the Lactobacillus family (Lactobacillus acidophilus, Lactobacillus brevis, Lactobacillus helveticus and Lactobacillus kefiri) over the infection of representative microorganisms important to human health. After the treatment of DC-SIGN expressing cells with these proteins, we were able to diminish bacterial infection by up to 79% in both gram negative and mycobacterial models. We discovered that pre-treatment of the bacteria with S-layers from Lactobacillus acidophilus and Lactobacillus brevis reduced bacteria viability but also prevent infection by the pathogenic bacteria. We also proved the importance of the glycosylation of the S-layer from Lactobacillus kefiri in the binding to the receptor and thus inhibition of infection. This novel characteristic of the S-layers proteins may contribute to the already reported pathogen exclusion activity for these Lactobacillus probiotic strains; and might be also considered as a novel enzymatic antimicrobial agents to inhibit bacterial infection and entry to host cells. Copyright © 2016 Elsevier B.V. All rights reserved.

CD4~+Foxp3~+ regulatory T cells converted by rapamycin from peripheral CD4~+ CD25~-naive T cells display more potent regulatory ability in vitro

Institute of Scientific and Technical Information of China (English)

CHEN Jian-fei; GAO Jie; ZHANG Dong; WANG Zi-han; ZHU Ji-ye

2010-01-01

Background Rapamycin (RAPA) is a relatively new immunosuppressant drug that functions as a serine/threonine kinase inhibitor to prevent rejection in organ transplantation. RAPA blocks activation of T-effector (Teff) cells by inhibiting the response to interleukin-2. Recently, RAPA was also shown to selectively expand the T-regulator (Treg) cell population. To date, no studies have examined the mechanism by which RAPA converts Teff cells to Treg cells. Methods Peripheral CD4~+CD25~- naive T cells were cultivated with RAPA and B cells as antigen-presenting cells (APCs) in vitro. CD4~+CD25~- T cells were harvested after 6 days and analyzed for expression of forkhead box protein 3 (Foxp3) using flow cytometry. CD4~+CD25~+CD127~- subsets as the converted Tregs were isolated from the mixed lymphocyte reactions (MLR) with CD127 negative selection, followed by CD4 and CD25 positive selection using microbeads and magnetic separation column (MSC). Moreover, mRNA was extracted from converted Tregs and C57BL/6 naive CD4~+CD25~+ T cells and Foxp3 levels were examined by quantitative real-time polymerase chain reaction (rt-PCR). A total of 1×10~5 carboxyfluorescein succinimidyl ester (CFSE)-labeled naive CD4~+CD25~- T cells/well from C57BL/6 mice were cocultured with DBA/2 or C3H maturation of dendritic cells (mDCs) (0.25×10~5/well) in 96-well round-bottom plates for 6 days. Then 1×10~5 or 0.25×10~5 converted Treg cells were added to every well as regulatory cells. Cells were harvested after 6 days of culture and analyzed for proliferation of CFSE-labeled naive CD4~+CD25~- T cells using flow cytometry. Data were analyzed using CellQuest software.Results We found that RAPA can convert peripheral CD4~+CD25~- naive T Cells to CD4~+Foxp3~+ Treg cells using B cells as APCs, and this subtype of Treg can potently suppress Teff proliferation and maintain antigenic specificity. Conclusion Our findings provide evidence that RAPA induces Treg cell conversion from Teff cells and

Different thresholds of T cell activation regulate FIV infection of CD4+CD25+ and CD4+CD25- cells

International Nuclear Information System (INIS)

Joshi, Anjali; Garg, Himanshu; Tompkins, Mary B.; Tompkins, Wayne A.

2005-01-01

Cellular activation plays an important role in retroviral replication. Previously, we have shown that CD4 + CD25 + T cells by the virtue of their partially activated phenotype represent ideal candidates for a productive feline immunodeficiency virus (FIV) infection. In the present study, we extended our previous observations with regard to FIV replication in CD4 + CD25 + and CD4 + CD25 - cells under different stimulation conditions. Both CD4 + CD25 + and CD4 + CD25 - cells remain latently infected in the absence of IL-2 or concanvalinA (ConA), respectively; harboring a replication competent provirus capable of reactivation several days post-infection. While CD4 + CD25 + cells require low levels of exogenous IL-2 and virus inputs for an efficient FIV replication, CD4 + CD25 - T cells can only be productively infected in the presence of either high concentrations of IL-2 or high virus titers, even in the absence of mitogenic stimulation. Interestingly, while high virus input activates CD4 + CD25 - cells to replicate FIV, it induces apoptosis in a high percentage of CD4 + CD25 + T cells. High IL-2 concentrations but not high virus inputs lead to surface upregulation of CD25 and significant cellular proliferation in CD4 + CD25 - cells. These results suggest that CD4 + CD25 + and CD4 + CD25 - T cells have different activation requirements which can be modulated by both viral and cytokine stimuli to reach threshold activation levels in order to harbor a productive FIV infection. This holds implications in vivo for CD4 + CD25 + and CD4 + CD25 - cells to serve as potential reservoirs of a productive and latent FIV infection

Increase of Circulating CD4(+)CD25(high)Foxp3(+) Regulatory T Cells in Patients With Metastatic Renal Cell Carcinoma During Treatment With Dendritic Cell Vaccination and Low-Dose Interleukin-2

DEFF Research Database (Denmark)

Berntsen, Annika; Brimnes, M.K.; Straten, P.T.

2010-01-01

Regulatory T cells (Treg) play an important role in the maintenance of immune tolerance and may be one of the obstacles of successful tumor immunotherapy. In this study, we analyzed the impact of administration of dendritic cell (DC) vaccination in combination with low-dose interleukin (IL)-2...... in patients with metastatic renal cell carcinoma on the frequency of CD4(+) CD25(high)Foxp3(+) Treg cells in peripheral blood. We found that the treatment increased the frequency of Treg cells more than 7-fold compared with pretreatment levels (P cells decreased when patients...... had been off IL-2 treatment for only 8 days, but remained higher than pretreatment levels. A functional assay showed that isolated Treg cells were capable of inhibiting proliferation of responder cells. Also, in vitro studies showed that coculture of mature DCs, autologous T cells and IL-2 leads...

Structural Basis for Species Selectivity in the HIV-1 gp120-CD4 Interaction: Restoring Affinity to gp120 in Murine CD4 Mimetic Peptides

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Kristin Kassler

2011-01-01

Full Text Available The first step of HIV-1 infection involves interaction between the viral glycoprotein gp120 and the human cellular receptor CD4. Inhibition of the gp120-CD4 interaction represents an attractive strategy to block HIV-1 infection. In an attempt to explore the known lack of affinity of murine CD4 to gp120, we have investigated peptides presenting the putative gp120-binding site of murine CD4 (mCD4. Molecular modeling indicates that mCD4 protein cannot bind gp120 due to steric clashes, while the larger conformational flexibility of mCD4 peptides allows an interaction. This finding is confirmed by experimental binding assays, which also evidenced specificity of the peptide-gp120 interaction. Molecular dynamics simulations indicate that the mCD4-peptide stably interacts with gp120 via an intermolecular β-sheet, while an important salt-bridge formed by a C-terminal lysine is lost. Fixation of the C-terminus by introducing a disulfide bridge between the N- and C-termini of the peptide significantly enhanced the affinity to gp120.

miR-20a inhibits TCR-mediated signaling and cytokine production in human naïve CD4+ T cells.

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Amarendra V Reddycherla

Full Text Available Upon TCR stimulation by peptide-MHC complexes, CD4+ T cells undergo activation and proliferation. This process will ultimately culminate in T-cell differentiation and the acquisition of effector functions. The production of specific cytokines by differentiated CD4+ T cells is crucial for the generation of the appropriate immune response. Altered CD4+ T-cell activation and cytokine production result in chronic inflammatory conditions and autoimmune disorders. miRNAs have been shown to be important regulators of T-cell biology. In this study, we have focused our investigation on miR-20a, a member of the miR-17-92 cluster, whose expression is decreased in patients suffering from multiple sclerosis. We have found that miR-20a is rapidly induced upon TCR-triggering in primary human naïve CD4+ T cells and that its transcription is regulated in a Erk-, NF-κB-, and Ca++-dependent manner. We have further shown that overexpression of miR-20a inhibits TCR-mediated signaling but not the proliferation of primary human naïve CD4+ T cells. However, miR-20a overexpression strongly suppresses IL-10 secretion and moderately decreases IL-2, IL-6 and IL8 production, which are crucial regulators of inflammatory responses. Our study suggests that miR-20a is a new player in the regulation of TCR signaling strength and cytokine production.

A novel differentiation pathway from CD4⁺ T cells to CD4⁻ T cells for maintaining immune system homeostasis.

Science.gov (United States)

Zhao, X; Sun, G; Sun, X; Tian, D; Liu, K; Liu, T; Cong, M; Xu, H; Li, X; Shi, W; Tian, Y; Yao, J; Guo, H; Zhang, D

2016-04-14

CD4(+) T lymphocytes are key players in the adaptive immune system and can differentiate into a variety of effector and regulatory T cells. Here, we provide evidence that a novel differentiation pathway of CD4(+) T cells shifts the balance from a destructive T-cell response to one that favors regulation in an immune-mediated liver injury model. Peripheral CD4(-)CD8(-)NK1.1(-) double-negative T cells (DNT) was increased following Concanavalin A administration in mice. Adoptive transfer of DNT led to significant protection from hepatocyte necrosis by direct inhibition on the activation of lymphocytes, a process that occurred primarily through the perforin-granzyme B route. These DNT converted from CD4(+) rather than CD8(+) T cells, a process primarily regulated by OX40. DNT migrated to the liver through the CXCR3-CXCL9/CXCL10 interaction. In conclusion, we elucidated a novel differentiation pathway from activated CD4(+) T cells to regulatory DNT cells for maintaining homeostasis of the immune system in vivo, and provided key evidence that utilizing this novel differentiation pathway has potential application in the prevention and treatment of autoimmune diseases.

Helminth antigens enable CpG-activated dendritic cells to inhibit the symptoms of collagen-induced arthritis through Foxp3+ regulatory T cells.

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Franco Carranza

Full Text Available Dendritic cells (DC have the potential to control the outcome of autoimmunity by modulating the immune response. In this study, we tested the ability of Fasciola hepatica total extract (TE to induce tolerogenic properties in CpG-ODN (CpG maturated DC, to then evaluate the therapeutic potential of these cells to diminish the inflammatory response in collagen induced arthritis (CIA. DBA/1J mice were injected with TE plus CpG treated DC (T/C-DC pulsed with bovine collagen II (CII between two immunizations with CII and clinical scores CIA were determined. The levels of CII-specific IgG2 and IgG1 in sera, the histological analyses in the joints, the cytokine profile in the draining lymph node (DLN cells and in the joints, and the number, and functionality of CD4+CD25+Foxp3+ T cells (Treg were evaluated. Vaccination of mice with CII pulsed T/C-DC diminished the severity and incidence of CIA symptoms and the production of the inflammatory cytokine, while induced the production of anti-inflammatory cytokines. The therapeutic effect was mediated by Treg cells, since the adoptive transfer of CD4+CD25+ T cells, inhibited the inflammatory symptoms in CIA. The in vitro blockage of TGF-β in cultures of DLN cells plus CII pulsed T/C-DC inhibited the expansion of Treg cells. Vaccination with CII pulsed T/C-DC seems to be a very efficient approach to diminish exacerbated immune response in CIA, by inducing the development of Treg cells, and it is therefore an interesting candidate for a cell-based therapy for rheumatoid arthritis (RA.

Preliminary study of CdTe and CdTe:Cu thin films nanostructures deposited by using DC magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Marwoto, Putut; Made, D. P. Ngurah; Sugianto [Departement of Physics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Semarang, Gunungpati, Semarang 50229 Jawa Tengah (Indonesia); Wibowo, Edy; Astuti, Santi Yuli; Aryani, Nila Prasetya [Materials Research Group, Laboratory of Thin Film, Department of Physics, Universitas Negeri Semarang, Gunungpati, Semarang 50229 Jawa Tengah (Indonesia); Othaman, Zulkafli [Departement of Physics, Universiti Teknologi Malaysia (UTM), Skudai, Johor Bahru (Malaysia)

2013-09-03

Growth and properties of CdTe and CdTe:Cu thin films nanostrucures deposited by using dc magnetron sputtering are reported. Scanning electron microscope (SEM) was used to observe the surface morphologies of the thin films. At growth conditions of 250 °C and 14 W, CdTe films did not yet evenly deposited. However, at growth temperature and plasma power of 325 °C and 43 W, both CdTe and CdTe:Cu(2%) have deposited on the substrates. In this condition, the morphology of the films indicate that the films have a grain-like nanostructures. Grain size diameter of about 200 nm begin to appear on top of the films. Energy Dispersive X-rays spectroscopy (EDX) was used to investigate chemical elements of the Cu doped CdTe film deposited. It was found that the film deposited consist of Cd, Te and Cu elements. XRD was used to investigate the full width at half maximum (FWHM) values of the thin films deposited. The results show that CdTe:Cu(2%) thin film has better crystallographic properties than CdTe thin film. The UV-Vis spectrometer was used to investigate the optical properties of thin films deposited. The transmittance spectra showed that transmittance of CdTe:Cu(2%) film is lower than CdTe film. It was found that the bandgap energy of CdTe and CdTe:Cu(2%) thin films of about 1.48 eV.

Attenuation of LPS-induced inflammation by ICT, a derivate of icariin, via inhibition of the CD14/TLR4 signaling pathway in human monocytes.

Science.gov (United States)

Wu, Jinfeng; Zhou, Junmin; Chen, Xianghong; Fortenbery, Nicole; Eksioglu, Erika A; Wei, Sheng; Dong, Jingcheng

2012-01-01

To evaluate the anti-inflammatory potential of ICT in LPS stimulated human innate immune cells. 3, 5, 7-Trihydroxy-4'-methoxy-8-(3-hydroxy-3- methylbutyl)-flavone (ICT) is a novel derivative of icariin, the major active ingredient of Herba Epimedii, an herb used in traditional Chinese medicine. We previously demonstrated its anti-inflammatory potential in a murine macrophage cell line as well as in mouse models. We measured TNF-α production by ELISA, TLR4/CD14 expression by flow cytometry, and NF-κB and MAPK activation by western blot all in LPS-stimulated PBMC, human monocytes, or THP-1 cells after treatment with ICT. ICT inhibited LPS-induced TNF-α production in THP-1 cells, PBMCs and human monocytes in a dose-dependent manner. ICT treatment resulted in down-regulation of the expression of CD14/TLR4 and attenuated NF-κB and MAPK activation induced by LPS. We illustrate the anti-inflammatory property of ICT in human immune cells, especially in monocytes. These effects were mediated, at least partially, via inhibition of the CD14/TLR4 signaling pathway. Copyright © 2011 Elsevier B.V. All rights reserved.

The Ixodes scapularis Salivary Protein, Salp15, Prevents the Association of HIV-1 gp120 and CD4

OpenAIRE

Juncadella, Ignacio J.; Garg, Renu; Bates, Tonya C.; Olivera, Elias R.; Anguita, Juan

2007-01-01

Ixodes scapularis salivary protein, Salp15, inhibits CD4+ T cell activation by binding to the most-extracellular domains of the CD4 molecule, potentially overlapping with the gp120-binding region. We now show that Salp15 inhibits the interaction of gp120 and CD4. Furthermore, Salp15 prevents syncytia formation between HL2/3 (a stable HeLa cell line expressing the envelope protein) and CD4-expressing cells. Salp15 prevented gp120-CD4 interaction at least partially through its direct interactio...

Characterization of Yellow Fever Virus Infection of Human and Non-human Primate Antigen Presenting Cells and Their Interaction with CD4+ T Cells.

Directory of Open Access Journals (Sweden)

Yu Cong

2016-05-01

Full Text Available Humans infected with yellow fever virus (YFV, a mosquito-borne flavivirus, can develop illness ranging from a mild febrile disease to hemorrhagic fever and death. The 17D vaccine strain of YFV was developed in the 1930s, has been used continuously since development and has proven very effective. Genetic differences between vaccine and wild-type viruses are few, yet viral or host mechanisms associated with protection or disease are not fully understood. Over the past 20 years, a number of cases of vaccine-associated disease have been identified following vaccination with 17D; these cases have been correlated with reduced immune status at the time of vaccination. Recently, several studies have evaluated T cell responses to vaccination in both humans and non-human primates, but none have evaluated the response to wild-type virus infection. In the studies described here, monocyte-derived macrophages (MDM and dendritic cells (MoDC from both humans and rhesus macaques were evaluated for their ability to support infection with either wild-type Asibi virus or the 17D vaccine strain and the host cytokine and chemokine response characterized. Human MoDC and MDM were also evaluated for their ability to stimulate CD4+ T cells. It was found that MoDC and MDM supported viral replication and that there were differential cytokine responses to infection with either wild-type or vaccine viruses. Additionally, MoDCs infected with live 17D virus were able to stimulate IFN-γ and IL-2 production in CD4+ T cells, while cells infected with Asibi virus were not. These data demonstrate that wild-type and vaccine YFV stimulate different responses in target antigen presenting cells and that wild-type YFV can inhibit MoDC activation of CD4+ T cells, a critical component in development of protective immunity. These data provide initial, but critical insight into regulatory capabilities of wild-type YFV in development of disease.

Bile salt-stimulated lipase from human milk binds DC-SIGN and inhibits human immunodeficiency virus type 1 transfer to CD4+ T cells

NARCIS (Netherlands)

Naarding, Marloes A.; Dirac, Annette M.; Ludwig, Irene S.; Speijer, Dave; Lindquist, Susanne; Vestman, Eva-Lotta; Stax, Martijn J.; Geijtenbeek, Teunis B. H.; Pollakis, Georgios; Hernell, Olle; Paxton, William A.

2006-01-01

A wide range of pathogens, including human immunodeficiency virus type 1 (HIV-1), hepatitis C virus, Ebola virus, cytomegalovirus, dengue virus, Mycobacterium, Leishmania, and Helicobacter pylori, can interact with dendritic cell (DC)-specific ICAM3-grabbing nonintegrin (DC-SIGN), expressed on DCs

The importance of Foxp3 antibody and fixation/permeabilization buffer combinations in identifying CD4+CD25+Foxp3+ regulatory T cells.

Science.gov (United States)

Law, Jacqueline P; Hirschkorn, Dale F; Owen, Rachel E; Biswas, Hope H; Norris, Philip J; Lanteri, Marion C

2009-12-01

Foxp3 is a key marker for CD4(+) regulatory T cells (T(regs)) and was used in developing a multiparameter flow cytometric panel to identify T(regs). Achieving reproducible staining and analysis first required optimization of Foxp3 staining. We present a comparative study of PCH101, 236A/E7, 3G3, 206D, 150D, and 259D/C7 clones of anti-human-Foxp3 antibodies used in combination with five different fixation/permeabilization buffers. Staining for CD25, CD152, and CD127 was also compared between fixation/permeabilization treatments. Promising antibody/buffer combinations were tested in a panel of peripheral blood mononuclear cells from 10 individuals, and then on fresh versus frozen cells from four individuals. Finally, different fluorochromes coupled to two representative antibodies were compared to optimize separation of Foxp3(+) from Foxp3(-) events. Foxp3 gates were set using two gating strategies based on CD127(+)CD25(-) "non-T(regs)" or based on isotype controls. For Foxp3 staining, the best conditions for fixation/permeabilization were obtained using the eBioscience Foxp3, Imgenex, BioLegend, and BD Foxp3 buffers. Comparing results from 10 subjects, 259D/C7, PCH101, 236A/E7, and 206D antibodies yielded statistically higher levels of Foxp3 cells than those by 150D and 3G3 antibodies (mean = 6.9, 5.1, 4.7, and 3.7% compared with 1.7, and 0.3% of CD25(+)Foxp3(+) events within CD4(+) cells, respectively). Importantly, the "nonspecificity" of some antibodies observed with a Foxp3 gate based on isotype controls could be eliminated by setting the Foxp3 gate on "non-T(regs)". Better separation of Foxp3(+) and Foxp3(-) populations was observed using the PCH101 clone coupled to Alexa647 compared with FITC or the 259D/C7 clone coupled to PE compared with Alexa488 fluorochrome. Foxp3 staining can be highly variable and depends on the choice of antibody/buffer pair and the fluorochrome used. Selecting the correct population for setting the Foxp3 gate is critical to avoid

CD4+/CD8+ double-positive T cells

DEFF Research Database (Denmark)

Overgaard, Nana H; Jung, Ji-Won; Steptoe, Raymond J

2015-01-01

CD4(+)/CD8(+) DP thymocytes are a well-described T cell developmental stage within the thymus. However, once differentiated, the CD4(+) lineage or the CD8(+) lineage is generally considered to be fixed. Nevertheless, mature CD4(+)/CD8(+) DP T cells have been described in the blood and peripheral...... cells, CD4(+)/CD8(+) T cell populations, outside of the thymus, have recently been described to express concurrently ThPOK and Runx3. Considerable heterogeneity exists within the CD4(+)/CD8(+) DP T cell pool, and the function of CD4(+)/CD8(+) T cell populations remains controversial, with conflicting...... reports describing cytotoxic or suppressive roles for these cells. In this review, we describe how transcriptional regulation, lineage of origin, heterogeneity of CD4 and CD8 expression, age, species, and specific disease settings influence the functionality of this rarely studied T cell population....

Virus-induced dysfunction of CD4+CD25+ T cells in patients with HTLV-I-associated neuroimmunological disease.

Science.gov (United States)

Yamano, Yoshihisa; Takenouchi, Norihiro; Li, Hong-Chuan; Tomaru, Utano; Yao, Karen; Grant, Christian W; Maric, Dragan A; Jacobson, Steven

2005-05-01

CD4(+)CD25(+) Tregs are important in the maintenance of immunological self tolerance and in the prevention of autoimmune diseases. As the CD4(+)CD25(+) T cell population in patients with human T cell lymphotropic virus type I-associated (HTLV-I-associated) myelopathy/tropical spastic paraparesis (HAM/TSP) has been shown to be a major reservoir for this virus, it was of interest to determine whether the frequency and function of CD4(+)CD25(+) Tregs in HAM/TSP patients might be affected. In these cells, both mRNA and protein expression of the forkhead transcription factor Foxp3, a specific marker of Tregs, were lower than those in CD4(+)CD25(+) T cells from healthy individuals. The virus-encoded transactivating HTLV-I tax gene was demonstrated to have a direct inhibitory effect on Foxp3 expression and function of CD4(+)CD25(+) T cells. This is the first report to our knowledge demonstrating the role of a specific viral gene product (HTLV-I Tax) on the expression of genes associated with Tregs (in particular, foxp3) resulting in inhibition of Treg function. These results suggest that direct human retroviral infection of CD4(+)CD25(+) T cells may be associated with the pathogenesis of HTLV-I-associated neurologic disease.

CD4+ T cell-derived novel peptide Thp5 induces interleukin-4 production in CD4+ T cells to direct T helper 2 cell differentiation.

Science.gov (United States)

Khan, Mohd Moin; Chatterjee, Samit; Dwivedi, Ved Prakash; Pandey, Nishant Kumar; Singh, Yogesh; Tousif, Sultan; Bhavesh, Neel Sarovar; Van Kaer, Luc; Das, Jyoti; Das, Gobardhan

2012-01-20

The differentiation of naïve CD4(+) T cells into T helper 2 (Th2) cells requires production of the cytokine IL-4 in the local microenvironment. It is evident that naïve/quiescently activated CD4(+) T cells produce the IL-4 that drives Th2 cell differentiation. Because early production of IL-4 in naïve T cells leads to preferential Th2 cell differentiation, this process needs to be tightly regulated so as to avoid catastrophic and misdirected Th2 cell differentiation. Here, we show that Thp5, a novel peptide with structural similarity to vasoactive intestinal peptide, regulates production of early IL-4 in newly activated CD4(+) T cells. Induction of IL-4 in CD4(+) T cells by Thp5 is independent of the transcription factor STAT6 but dependent on ERK1/2 signaling. Furthermore, cytokines (IL-12 and TGF-β) that promote the differentiation of Th1 or Th17 cells inhibit Thp5 induction, thus suppressing Th2 cell differentiation. We further showed that Thp5 enhances Th2 responses and exacerbates allergic airway inflammation in mice. Taken together, our findings reveal that early activated CD4(+) T cells produce Thp5, which plays a critical role as a molecular switch in the differentiation of Th cells, biasing the response toward the Th2 cell phenotype.

Curcumin blocks interleukin (IL)-2 signaling in T-lymphocytes by inhibiting IL-2 synthesis, CD25 expression, and IL-2 receptor signaling

International Nuclear Information System (INIS)

Forward, Nicholas A.; Conrad, David M.; Power Coombs, Melanie R.; Doucette, Carolyn D.; Furlong, Suzanne J.; Lin, Tong-Jun; Hoskin, David W.

2011-01-01

Highlights: → Curcumin inhibits CD4 + T-lymphocyte proliferation. → Curcumin inhibits interleukin-2 (IL-2) synthesis and CD25 expression by CD4 + T-lymphocytes. → Curcumin interferes with IL-2 receptor signaling by inhibiting JAK3 and STAT5 phosphorylation. → IL-2-dependent regulatory T-lymphocyte function and Foxp3 expression is downregulated by curcumin. -- Abstract: Curcumin (diferulomethane) is the principal curcuminoid in the spice tumeric and a potent inhibitor of activation-induced T-lymphocyte proliferation; however, the molecular basis of this immunosuppressive effect has not been well studied. Here we show that micromolar concentrations of curcumin inhibited DNA synthesis by mouse CD4 + T-lymphocytes, as well as interleukin-2 (IL-2) and CD25 (α chain of the high affinity IL-2 receptor) expression in response to antibody-mediated cross-linking of CD3 and CD28. Curcumin acted downstream of protein kinase C activation and intracellular Ca 2+ release to inhibit IκB phosphorylation, which is required for nuclear translocation of the transcription factor NFκB. In addition, IL-2-dependent DNA synthesis by mouse CTLL-2 cells, but not constitutive CD25 expression, was impaired in the presence of curcumin, which demonstrated an inhibitory effect on IL-2 receptor (IL-2R) signaling. IL-2-induced phosphorylation of STAT5A and JAK3, but not JAK1, was diminished in the presence of curcumin, indicating inhibition of critical proximal events in IL-2R signaling. In line with the inhibitory action of curcumin on IL-2R signaling, pretreatment of CD4 + CD25 + regulatory T-cells with curcumin downregulated suppressor function, as well as forkhead box p3 (Foxp3) expression. We conclude that curcumin inhibits IL-2 signaling by reducing available IL-2 and high affinity IL-2R, as well as interfering with IL-2R signaling.

[Regulatory T cells inhibit proliferation of mouse lymphoma cell line EL4 in vitro].

Science.gov (United States)

Zhang, Chen; Kong, Yan; Guo, Jun; Ying, Zhi-Tao; Yuan, Zhi-Hong; Zhang, Yun-Tao; Zheng, Wen; Song, Yu-Qin; Li, Ping-Ping; Zhu, Jun

2010-10-01

This study was aimed to investigate the effect of regulatory T (Treg) cells on the T cell lymphoma EL4 cells and its mechanism in vitro. C57BL/6 mouse Treg cells were isolated by magnetic cell sorting (MACS). The purity of Treg cells and their expression of Foxp3 were identified by flow cytometry (FCM) and PT-PCR respectively. The suppression of Treg cells on EL4 cells was detected by 3H-TdR method. At the same time, enzyme-linked immunosorbent assay (ELISA) was used to detect the secretion of cytokine TGF-β1 and IL-10. The results showed that CD4+CD25+ T cells could be successfully isolated by MACS with the purity reaching 94.52% and the expression of Foxp3 reaching 84.72%. After sorting, the expression of Foxp3 mRNA could be detected by RT-PCR. 3H-TdR assay confirmed that regulatory T cells could suppress the proliferation of EL4 cells with or without antigen presenting cells (APC) or dendritic cells (DC), APC or DC might effectively enhance the suppression. In addition, DC alone also suppressed the proliferation. TGF-β1 and IL-10 could be detected in the supernatant by ELISA. It is concluded that the Treg cells can obviously suppress the proliferation of T cell lymphoma cells in vitro, APC or DC can enhance this suppressive effect, while the DC alone also can suppress the proliferation of EL4 cells, the TGF-β1 and IL-10 cytokine pathway may be one of the mechanisms of suppression.

Monitoring of regulatory T cell frequencies and expression of CTLA-4 on T cells, before and after DC vaccination, can predict survival in GBM patients.

Directory of Open Access Journals (Sweden)

Brendan Fong

Full Text Available PURPOSE: Dendritic cell (DC vaccines have recently emerged as an innovative therapeutic option for glioblastoma patients. To identify novel surrogates of anti-tumor immune responsiveness, we studied the dynamic expression of activation and inhibitory markers on peripheral blood lymphocyte (PBL subsets in glioblastoma patients treated with DC vaccination at UCLA. EXPERIMENTAL DESIGN: Pre-treatment and post-treatment PBL from 24 patients enrolled in two Phase I clinical trials of dendritic cell immunotherapy were stained and analyzed using flow cytometry. A univariate Cox proportional hazards model was utilized to investigate the association between continuous immune monitoring variables and survival. Finally, the immune monitoring variables were dichotomized and a recursive partitioning survival tree was built to obtain cut-off values predictive of survival. RESULTS: The change in regulatory T cell (CD3(+CD4(+CD25(+CD127(low frequency in PBL was significantly associated with survival (p = 0.0228; hazard ratio = 3.623 after DC vaccination. Furthermore, the dynamic expression of the negative co-stimulatory molecule, CTLA-4, was also significantly associated with survival on CD3(+CD4(+ T cells (p = 0.0191; hazard ratio = 2.840 and CD3(+CD8(+ T cells (p = 0.0273; hazard ratio = 2.690, while that of activation markers (CD25, CD69 was not. Finally, a recursive partitioning tree algorithm was utilized to dichotomize the post/pre fold change immune monitoring variables. The resultant cut-off values from these immune monitoring variables could effectively segregate these patients into groups with significantly different overall survival curves. CONCLUSIONS: Our results suggest that monitoring the change in regulatory T cell frequencies and dynamic expression of the negative co-stimulatory molecules on peripheral blood T cells, before and after DC vaccination, may predict survival. The cut-off point generated from these data can be utilized in future

Galectin-7 promotes proliferation and Th1/2 cells polarization toward Th1 in activated CD4+ T cells by inhibiting The TGFβ/Smad3 pathway.

Science.gov (United States)

Luo, Zhenlong; Ji, Yudong; Tian, Dean; Zhang, Yong; Chang, Sheng; Yang, Chao; Zhou, Hongmin; Chen, Zhonghua Klaus

2018-06-08

Galectin-7 (Gal-7) has been associated with cell proliferation and apoptosis. It is known that Gal-7 antagonises TGFβ-mediated effects in hepatocytes by interacting with Smad3. Previously, we have demonstrated that Gal-7 is related to CD4+ T cells responses; nevertheless, its effect and functional mechanism on CD4+ T cells responses remain unclear. The murine CD4+ T cells were respectively cultured with Gal-7, anti-CD3/CD28 mAbs, or with anti-CD3/CD28 mAbs & Gal-7. The effects of Gal-7 on proliferation and the phenotypic changes in CD4+ T cells were assessed by flow cytometry. The cytokines from CD4+ T cells were analysed by quantitative real-time PCR. Subcellular localisation and expression of Smad3 were determined by immunofluorescence staining and Western blot, respectively. Gal-7 enhanced the proliferation of activated CD4+ T cells in a dose- and β-galactoside-dependent manner. Additionally, Gal-7 treatment did not change the ratio of Th2 cells in activated CD4+ T cells, while it increased the ratio of Th1 cells. Gal-7 also induced activated CD4+ T cells to produce a higher level of IFN-γ and TNF-α and a lower level of IL-10. Moreover, Gal-7 treatment significantly accelerated nuclear export of Smad3 in activated CD4+ T cells. These results revealed a novel role of Gal-7 in promoting proliferation and Th1/2 cells polarization toward Th1 in activated CD4+ T cells by inhibiting the TGFβ/Smad3 pathway. Copyright © 2018 Elsevier Ltd. All rights reserved.

Induction of CD4 suppressor T cells with anti-Leu-8 antibody

International Nuclear Information System (INIS)

Kanof, M.E.; Strober, W.; James, S.P.

1987-01-01

To characterize the conditions under which CD4 T cells suppress polyclonal immunoglobulin synthesis, we investigated the capacity of CD4 T cells that coexpress the surface antigen recognized by the monoclonal antibody anti-Leu-8 to mediate suppression. In an in vitro system devoid of CD8 T cells, CD4, Leu-8+ T cells suppressed pokeweed mitogen-induced immunoglobulin synthesis. Similarly, suppressor function was induced in unfractionated CD4 T cell populations after incubation with anti-Leu-8 antibody under cross-linking conditions. This induction of suppressor function by anti-Leu-8 antibody was not due to expansion of the CD4, Leu-8+ T cell population because CD4 T cells did not proliferate in response to anti-Leu-8 antibody. However, CD4, Leu-8+ T cell-mediated suppression was radiosensitive. Finally, CD4, Leu-8+ T cells do not inhibit immunoglobulin synthesis when T cell lymphokines were used in place of helper CD4 T cells (CD4, Leu-8- T cells), suggesting that CD4 T cell-mediated suppression occurs at the T cell level. We conclude that CD4 T cells can be induced to suppress immunoglobulin synthesis by modulation of the membrane antigen recognized by anti-Leu-8 antibody

Saccharomyces boulardii inhibits lipopolysaccharide-induced activation of human dendritic cells and T cell proliferation

Science.gov (United States)

Thomas, S; Przesdzing, I; Metzke, D; Schmitz, J; Radbruch, A; Baumgart, D C

2009-01-01

Saccharomyces boulardii (Sb) is a probiotic yeast preparation that has demonstrated efficacy in inflammatory and infectious disorders of the gastrointestinal tract in controlled clinical trials. Although patients clearly benefit from treatment with Sb, little is known on how Sb unfolds its anti-inflammatory properties in humans. Dendritic cells (DC) balance tolerance and immunity and are involved critically in the control of T cell activation. Thus, they are believed to have a pivotal role in the initiation and perpetuation of chronic inflammatory disorders, not only in the gut. We therefore decided to investigate if Sb modulates DC function. Culture of primary (native, non-monocyte-derived) human myeloid CD1c+CD11c+CD123– DC (mDC) in the presence of Sb culture supernatant (active component molecular weight < 3 kDa, as evaluated by membrane partition chromatography) reduced significantly expression of the co-stimulatory molecules CD40 and CD80 (P < 0·01) and the DC mobilization marker CC-chemokine receptor CCR7 (CD197) (P < 0·001) induced by the prototypical microbial antigen lipopolysaccharide (LPS). Moreover, secretion of key proinflammatory cytokines such as tumour necrosis factor-α and interleukin (IL)-6 were notably reduced, while the secretion of anti-inflammatory IL-10 increased. Finally, Sb supernatant inhibited the proliferation of naive T cells in a mixed lymphocyte reaction with mDC. In summary, our data suggest that Sb may exhibit part of its anti-inflammatory potential through modulation of DC phenotype, function and migration by inhibition of their immune response to bacterial microbial surrogate antigens such as LPS. PMID:19161443

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

Science.gov (United States)

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

2017-01-01

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

Natural CD8+25+ regulatory T cell-secreted exosomes capable of suppressing cytotoxic T lymphocyte-mediated immunity against B16 melanoma

International Nuclear Information System (INIS)

Xie, Yufeng; Zhang, Xueshu; Zhao, Tuo; Li, Wei; Xiang, Jim

2013-01-01

Highlights: •CD8 + 25 + regulatory T cells secrete tolerogenic exosomes. •CD8 + 25 + regulatory T cell-derived exosomes exhibit immunosuppressive effect. •CD8 + 25 + regulatory T cell-derived exosomes inhibit antitumor immunity. -- Abstract: Natural CD4 + 25 + and CD8 + 25 + regulatory T (Tr) cells have been shown to inhibit autoimmune diseases. Immune cells secrete exosomes (EXOs), which are crucial for immune regulation. However, immunomodulatory effect of natural Tr cell-secreted EXOs is unknown. In this study, we purified natural CD8 + 25 + Tr cells from C57BL/6 mouse naive CD8 + T cells, and in vitro amplified them with CD3/CD28 beads. EXOs (EXO Tr ) were purified from Tr cell’s culture supernatants by differential ultracentrifugation and analyzed by electron microscopy, Western blot and flow cytometry. Our data showed that EXO Tr had a “saucer” or round shape with 50–100 nm in diameter, contained EXO-associated markers LAMP-1 and CD9, and expressed natural Tr cell markers CD25 and GITR. To assess immunomodulatory effect, we i.v. immunized C57BL/6 mice with ovalbumin (OVA)-pulsed DCs (DC OVA ) plus Tr cells or EXO Tr , and then assessed OVA-specific CD8 + T cell responses using PE-H-2K b /OVA tetramer and FITC-anti-CD8 antibody staining by flow cytometry and antitumor immunity in immunized mice with challenge of OVA-expressing BL6–10 OVA melanoma cells. We demonstrated that DC OVA -stimulated CD8 + T cell responses and protective antitumor immunity significantly dropped from 2.52% to 1.08% and 1.81% (p OVA (p Tr , respectively. Our results indicate that natural CD8 + 25 + Tr cell-released EXOs, alike CD8 + 25 + Tr cells, can inhibit CD8 + T cell responses and antitumor immunity. Therefore, EXOs derived from natural CD4 + 25 + and CD8 + 25 + Tr cells may become an alternative for immunotherapy of autoimmune diseases

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

Science.gov (United States)

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

2017-08-01

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

CD4-specific designed ankyrin repeat proteins are novel potent HIV entry inhibitors with unique characteristics.

Directory of Open Access Journals (Sweden)

Andreas Schweizer

2008-07-01

Full Text Available Here, we describe the generation of a novel type of HIV entry inhibitor using the recently developed Designed Ankyrin Repeat Protein (DARPin technology. DARPin proteins specific for human CD4 were selected from a DARPin DNA library using ribosome display. Selected pool members interacted specifically with CD4 and competed with gp120 for binding to CD4. DARPin proteins derived in the initial selection series inhibited HIV in a dose-dependent manner, but showed a relatively high variability in their capacity to block replication of patient isolates on primary CD4 T cells. In consequence, a second series of CD4-specific DARPins with improved affinity for CD4 was generated. These 2nd series DARPins potently inhibit infection of genetically divergent (subtype B and C HIV isolates in the low nanomolar range, independent of coreceptor usage. Importantly, the actions of the CD4 binding DARPins were highly specific: no effect on cell viability or activation, CD4 memory cell function, or interference with CD4-independent virus entry was observed. These novel CD4 targeting molecules described here combine the unique characteristics of DARPins-high physical stability, specificity and low production costs-with the capacity to potently block HIV entry, rendering them promising candidates for microbicide development.

Blocking the recruitment of naive CD4+ T cells reverses immunosuppression in breast cancer

Institute of Scientific and Technical Information of China (English)

Shicheng Su; Ling Lin; Yunjie Zeng; Nengtai Ouyang; Xiuying Cui; Herui Yao; Fengxi Su; Jian-dong Huang; Judy Lieberman; Qiang Liu; Erwei Song; Jianyou Liao; Jiang Liu; Di Huang; Chonghua He; Fei Chen; LinBing Yang; Wei Wu; Jianing Chen

2017-01-01

The origin of tumor-infiltrating Tregs,critical mediators of tumor immunosuppression,is unclear.Here,we show that tumor-infiltrating naive CD4+ T cells and Tregs in human breast cancer have overlapping TCR repertoires,while hardly overlap with circulating Tregs,suggesting that intratumoral Tregs mainly develop from naive T cells in situ rather than from recruited Tregs.Furthermore,the abundance of naive CD4+ T cells and Tregs is closely correlated,both indicating poor prognosis for breast cancer patients.Naive CD4+ T cells adhere to tumor slices in proportion to the abundance of CCLl8-producing macrophages.Moreover,adoptively transferred human naive CD4+ T cells infiltrate human breast cancer orthotopic xenografts in a CCL18-dependent manner.In human breast cancer xenografts in humanized mice,blocking the recruitment of naive CD4+ T cells into tumor by knocking down the expression of PITPNM3,a CCL18 receptor,significantly reduces intratumoral Tregs and inhibits tumor progression.These findings suggest that breast tumor-infiltrating Tregs arise from chemotaxis of circulating naive CD4+ T cells that differentiate into Tregs in situ.Inhibiting naive CD4+ T cell recruitment into tumors by interfering with PITPNM3 recognition of CCL18 may be an attractive strategy for anticancer immunotherapy.

Blocking the recruitment of naive CD4+ T cells reverses immunosuppression in breast cancer

Science.gov (United States)

Su, Shicheng; Liao, Jianyou; Liu, Jiang; Huang, Di; He, Chonghua; Chen, Fei; Yang, LinBing; Wu, Wei; Chen, Jianing; Lin, Ling; Zeng, Yunjie; Ouyang, Nengtai; Cui, Xiuying; Yao, Herui; Su, Fengxi; Huang, Jian-dong; Lieberman, Judy; Liu, Qiang; Song, Erwei

2017-01-01

The origin of tumor-infiltrating Tregs, critical mediators of tumor immunosuppression, is unclear. Here, we show that tumor-infiltrating naive CD4+ T cells and Tregs in human breast cancer have overlapping TCR repertoires, while hardly overlap with circulating Tregs, suggesting that intratumoral Tregs mainly develop from naive T cells in situ rather than from recruited Tregs. Furthermore, the abundance of naive CD4+ T cells and Tregs is closely correlated, both indicating poor prognosis for breast cancer patients. Naive CD4+ T cells adhere to tumor slices in proportion to the abundance of CCL18-producing macrophages. Moreover, adoptively transferred human naive CD4+ T cells infiltrate human breast cancer orthotopic xenografts in a CCL18-dependent manner. In human breast cancer xenografts in humanized mice, blocking the recruitment of naive CD4+ T cells into tumor by knocking down the expression of PITPNM3, a CCL18 receptor, significantly reduces intratumoral Tregs and inhibits tumor progression. These findings suggest that breast tumor-infiltrating Tregs arise from chemotaxis of circulating naive CD4+ T cells that differentiate into Tregs in situ. Inhibiting naive CD4+ T cell recruitment into tumors by interfering with PITPNM3 recognition of CCL18 may be an attractive strategy for anticancer immunotherapy. PMID:28290464

Function and regulation of LAG3 on CD4+CD25- T cells in non-small cell lung cancer.

Science.gov (United States)

Ma, Qin-Yun; Huang, Da-Yu; Zhang, Hui-Jun; Wang, Shaohua; Chen, Xiao-Feng

2017-11-15

LAG3 is a surface molecule found on a subset of immune cells. The precise function of LAG3 appears to be context-dependent. In this study, we investigated the effect of LAG3 on CD4 + CD25 - T cells from non-small cell lung cancer (NSCLC) patients. We found that in the peripheral blood mononuclear cells of NSCLC patients, LAG3 was significantly increased in CD4 + T cells directly ex vivo and primarily in the CD4 + CD25 - fraction, which was regulated by prolonged TCR stimulation and the presence of IL-27. TCR stimulation also increased CD25 expression, but not Foxp3 expression, in LAG3-expressing CD4 + CD25 - cells Compared to LAG3-nonexpressing CD4 + CD25 - cells, LAG3-expressing CD4 + CD25 - cells presented significantly higher levels of PD1 and TIM3, two inhibitory receptors best described in exhausted CD8 + T effector cells. LAG3-expressing CD4 + CD25 - cells also presented impaired proliferation compared with LAG3-nonexpressing CD4 + CD25 - cells but could be partially rescued by inhibiting both PD1 and TIM3. Interestingly, CD8 + T cells co-incubated with LAG3-expressing CD4 + CD25 - cells at equal cell numbers demonstrated significantly lower proliferation than CD8 + T cells incubated alone. Co-culture with CD8 + T cell and LAG3-expressing CD4 + CD25 - T cell also upregulated soluble IL-10 level in the supernatant, of which the concentration was positively correlated with the number of LAG3-expressing CD4 + CD25 - T cells. In addition, we found that LAG3-expressing CD4 + CD25 - T cells infiltrated the resected tumors and were present at higher frequencies of in metastases than in primary tumors. Taken together, these data suggest that LAG3-expressing CD4 + CD25 - T cells represent another regulatory immune cell type with potential to interfere with anti-tumor immunity. Copyright © 2017 Elsevier Inc. All rights reserved.

ImmunoPET Imaging of Murine CD4+ T Cells Using Anti-CD4 Cys-Diabody: Effects of Protein Dose on T Cell Function and Imaging.

Science.gov (United States)

Freise, Amanda C; Zettlitz, Kirstin A; Salazar, Felix B; Lu, Xiang; Tavaré, Richard; Wu, Anna M

2017-08-01

Molecular imaging of CD4 + T cells throughout the body has implications for monitoring autoimmune disease and immunotherapy of cancer. Given the key role of these cells in regulating immunity, it is important to develop a biologically inert probe. GK1.5 cys-diabody (cDb), a previously developed anti-mouse CD4 antibody fragment, was tested at different doses to assess its effects on positron emission tomography (PET) imaging and CD4 + T cell viability, proliferation, CD4 expression, and function. The effect of protein dose on image contrast (lymphoid tissue-to-muscle ratio) was assessed by administering different amounts of 89 Zr-labeled GK1.5 cDb to mice followed by PET imaging and ex vivo biodistribution analysis. To assess impact of GK1.5 cDb on T cell biology, GK1.5 cDb was incubated with T cells in vitro or administered intravenously to C57BL/6 mice at multiple protein doses. CD4 expression and T cell proliferation were analyzed with flow cytometry and cytokines were assayed. For immunoPET imaging, the lowest protein dose of 2 μg of 89 Zr-labeled GK1.5 cDb resulted in significantly higher % injected dose/g in inguinal lymph nodes (ILN) and spleen compared to the 12-μg protein dose. In vivo administration of GK1.5 cDb at the high dose of 40 μg caused a transient decrease in CD4 expression in spleen, blood, lymph nodes, and thymus, which recovered within 3 days postinjection; this effect was reduced, although not abrogated, when 2 μg was administered. Proliferation was inhibited in vivo in ILN but not the spleen by injection of 40 μg GK1.5 cDb. Concentrations of GK1.5 cDb in excess of 25 nM significantly inhibited CD4 + T cell proliferation and interferon-γ production in vitro. Overall, using low-dose GK1.5 cDb minimized biological effects on CD4 + T cells. Low-dose GK1.5 cDb yields high-contrast immunoPET images with minimal effects on T cell biology in vitro and in vivo and may be a useful tool for investigating CD4 + T cells in the context of

Influence of DC-CIK in advanced colorectal cancer patients on T lymphocyte subsets and cytokines

Directory of Open Access Journals (Sweden)

Rong Wang

2016-07-01

Full Text Available Objective: To explore the effects of dendritic cells (DC-cytokine induced killer cells (CIK treatment on T lymphocyte subsets and cytokines in patients with advanced colorectal cancer. Methods: A total of 84 cases patients with advanced colorectal cancer were divided into two groups according to random number table method, each 42 cases, both two groups were given FOLFOX scheme chemotherapy, on the basis, the observation group were given supplementary DC-CIK treatment, compared the T lymphocy te subgroup: CD3+, CD4+, CD8+, CD4+/CD8+, Th1 cytokines, interleukin-2 (IL-2 and interferon gamma-γ (FN-γ, Th2 cytokines: interleukin 6 (IL-6, interleukin 4 (IL-4 of the two groups before and after treatment. Results: Compared with before treatment, the CD3+, CD4+, CD8+, CD4+/CD8+, Th1 cytokines IL-2 and IFN-γ in observation group were significantly higher than after treatment , the CD3+, CD4+, CD8+, CD4+/CD8+, Th1 cytokines IL-2 and IFN-γ in control group were significantly lower than after treatment, and the differences were all statistically significant; The CD3+, CD4+, CD8+, CD4+/CD8+, Th1 cytokines IL-2 and IFN-γ in observation group after treatment were significantly higher than those in control group after treatment with statistical difference; CD8+, Th2 cytokines IL-4, IL-6 in two groups had no statistical significance before and after treatment. Conclusion: Chemotherapy can cause the immune function restrained in patients with advanced colorectal cancer, and DC-CIK supplementary therapy can significantly improve the immune function, enhance the anti tumor immune responses.

Curcumin blocks interleukin (IL)-2 signaling in T-lymphocytes by inhibiting IL-2 synthesis, CD25 expression, and IL-2 receptor signaling

Energy Technology Data Exchange (ETDEWEB)

Forward, Nicholas A.; Conrad, David M. [Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia (Canada); Power Coombs, Melanie R.; Doucette, Carolyn D. [Department of Pathology, Dalhousie University, Halifax, Nova Scotia (Canada); Furlong, Suzanne J. [Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia (Canada); Lin, Tong-Jun [Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia (Canada); Department of Pediatrics, Dalhousie University, Halifax, Nova Scotia (Canada); Hoskin, David W., E-mail: d.w.hoskin@dal.ca [Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia (Canada); Department of Pathology, Dalhousie University, Halifax, Nova Scotia (Canada); Department of Surgery, Dalhousie University, Halifax, Nova Scotia (Canada)

2011-04-22

Highlights: {yields} Curcumin inhibits CD4{sup +} T-lymphocyte proliferation. {yields} Curcumin inhibits interleukin-2 (IL-2) synthesis and CD25 expression by CD4{sup +} T-lymphocytes. {yields} Curcumin interferes with IL-2 receptor signaling by inhibiting JAK3 and STAT5 phosphorylation. {yields} IL-2-dependent regulatory T-lymphocyte function and Foxp3 expression is downregulated by curcumin. -- Abstract: Curcumin (diferulomethane) is the principal curcuminoid in the spice tumeric and a potent inhibitor of activation-induced T-lymphocyte proliferation; however, the molecular basis of this immunosuppressive effect has not been well studied. Here we show that micromolar concentrations of curcumin inhibited DNA synthesis by mouse CD4{sup +} T-lymphocytes, as well as interleukin-2 (IL-2) and CD25 ({alpha} chain of the high affinity IL-2 receptor) expression in response to antibody-mediated cross-linking of CD3 and CD28. Curcumin acted downstream of protein kinase C activation and intracellular Ca{sup 2+} release to inhibit I{kappa}B phosphorylation, which is required for nuclear translocation of the transcription factor NF{kappa}B. In addition, IL-2-dependent DNA synthesis by mouse CTLL-2 cells, but not constitutive CD25 expression, was impaired in the presence of curcumin, which demonstrated an inhibitory effect on IL-2 receptor (IL-2R) signaling. IL-2-induced phosphorylation of STAT5A and JAK3, but not JAK1, was diminished in the presence of curcumin, indicating inhibition of critical proximal events in IL-2R signaling. In line with the inhibitory action of curcumin on IL-2R signaling, pretreatment of CD4{sup +}CD25{sup +} regulatory T-cells with curcumin downregulated suppressor function, as well as forkhead box p3 (Foxp3) expression. We conclude that curcumin inhibits IL-2 signaling by reducing available IL-2 and high affinity IL-2R, as well as interfering with IL-2R signaling.

Natural CD8{sup +}25{sup +} regulatory T cell-secreted exosomes capable of suppressing cytotoxic T lymphocyte-mediated immunity against B16 melanoma

Energy Technology Data Exchange (ETDEWEB)

Xie, Yufeng; Zhang, Xueshu; Zhao, Tuo; Li, Wei; Xiang, Jim, E-mail: jim.xiang@saskcancer.ca

2013-08-16

Highlights: •CD8{sup +}25{sup +} regulatory T cells secrete tolerogenic exosomes. •CD8{sup +}25{sup +} regulatory T cell-derived exosomes exhibit immunosuppressive effect. •CD8{sup +}25{sup +} regulatory T cell-derived exosomes inhibit antitumor immunity. -- Abstract: Natural CD4{sup +}25{sup +} and CD8{sup +}25{sup +} regulatory T (Tr) cells have been shown to inhibit autoimmune diseases. Immune cells secrete exosomes (EXOs), which are crucial for immune regulation. However, immunomodulatory effect of natural Tr cell-secreted EXOs is unknown. In this study, we purified natural CD8{sup +}25{sup +} Tr cells from C57BL/6 mouse naive CD8{sup +} T cells, and in vitro amplified them with CD3/CD28 beads. EXOs (EXO{sub Tr}) were purified from Tr cell’s culture supernatants by differential ultracentrifugation and analyzed by electron microscopy, Western blot and flow cytometry. Our data showed that EXO{sub Tr} had a “saucer” or round shape with 50–100 nm in diameter, contained EXO-associated markers LAMP-1 and CD9, and expressed natural Tr cell markers CD25 and GITR. To assess immunomodulatory effect, we i.v. immunized C57BL/6 mice with ovalbumin (OVA)-pulsed DCs (DC{sub OVA}) plus Tr cells or EXO{sub Tr}, and then assessed OVA-specific CD8{sup +} T cell responses using PE-H-2K{sup b}/OVA tetramer and FITC-anti-CD8 antibody staining by flow cytometry and antitumor immunity in immunized mice with challenge of OVA-expressing BL6–10{sub OVA} melanoma cells. We demonstrated that DC{sub OVA}-stimulated CD8{sup +} T cell responses and protective antitumor immunity significantly dropped from 2.52% to 1.08% and 1.81% (p < 0.05), and from 8/8 to 2/8 and 5/8 mice DC{sub OVA} (p < 0.05) in immunized mice with co-injection of Tr cells and EXO{sub Tr}, respectively. Our results indicate that natural CD8{sup +}25{sup +} Tr cell-released EXOs, alike CD8{sup +}25{sup +} Tr cells, can inhibit CD8{sup +} T cell responses and antitumor immunity. Therefore, EXOs derived from

Human amniotic epithelial cells inhibit CD4+ T cell activation in acute kidney injury patients by influencing the miR-101-c-Rel-IL-2 pathway.

Science.gov (United States)

Liu, Junfeng; Hua, Rong; Gong, Zhangbin; Shang, Bin; Huang, Yongyi; Guo, Lihe; Liu, Te; Xue, Jun

2017-01-01

In the pathogenesis of acute kidney injury (AKI), the release of multiple interleukins can lead to increased kidney damage. Human amniotic epithelial cells (HuAECs) can inhibit immune cell activation in vivo and in vitro. We hypothesized that HuAECs could weaken patient-derived peripheral blood CD4+ T-cell activation and decreasing the ability of these cells to express and release IL-2. -Cell proliferation assay revealed that under the same culture conditions, activated AKI patient-derived CD4+ T cells had a significantly reduced proliferation rate when were co-cultured with HuAECs. And the level of IL-2 released was also significantly reduced. Western blot and qRT-PCR assays showed that the expression of c-Rel in the CD4+ T cells was also significantly reduced. However, the expression level of endogenous miR-101 in the CD4+ T cells co-cultured with HuAECs was significantly increased. Luciferase reporter assay results suggested that miR-101 could bind to a specific site in the c-Rel 3' UTR and induce the post-transcriptional silencing of c-Rel. Subsequently, we over-expressed miR-101 in AKI patient-derived CD4+ T cells. The qRT-PCR and western blot assay results revealed that the expression of endogenous c-Rel was significantly reduced, while the ELISA results indicated that the level of IL-2 released was also significantly decreased. Finally, ChIP-PCR assay results showed that the miR-101-overexpressing CD4+ T-cell group and the HuAEC co-culture CD4+ T-cell group exhibited significantly decreased binding capacities between the 'c-Rel-NFκB' complex and the IL-2 gene promoter, and the transcriptional activity of IL-2 was also significantly decreased. Therefore, we confirmed that HuAECs can stimulate miR-101 expression in AKI patient-derived peripheral blood CD4+ T cells, thus inhibiting the expression of the miR-101 target gene c-Rel and leading to a reduction in IL-2 expression and release. Copyright © 2016 Elsevier Ltd. All rights reserved.

Novel teleost CD4-bearing cell populations provide insights into the evolutionary origins and primordial roles of CD4+ lymphocytes and CD4+ macrophages

OpenAIRE

Takizawa, Fumio; Magadan, Susana; Parra, David; Xu, Zhen; Koryt����, Tom����; Boudinot, Pierre; Sunyer, J. Oriol

2016-01-01

Tetrapods contain a single CD4 co-receptor with four immunoglobulin domains that likely arose from a primordial two-domain ancestor. Notably, teleost fish contain two CD4 genes. Like tetrapod CD4, CD4-1 of rainbow trout includes four immunoglobulin domains while CD4-2 contains only two. Since CD4-2 is reminiscent of the prototypic two-domain CD4 co-receptor, we hypothesized that by characterizing the cell types bearing CD4-1 and CD4-2, we would shed light into the evolution and primordial rol...

Cutting Edge: 2B4-Mediated Coinhibition of CD4+ T Cells Underlies Mortality in Experimental Sepsis.

Science.gov (United States)

Chen, Ching-Wen; Mittal, Rohit; Klingensmith, Nathan J; Burd, Eileen M; Terhorst, Cox; Martin, Greg S; Coopersmith, Craig M; Ford, Mandy L

2017-09-15

Sepsis is a leading cause of death in the United States, but the mechanisms underlying sepsis-induced immune dysregulation remain poorly understood. 2B4 (CD244, SLAM4) is a cosignaling molecule expressed predominantly on NK cells and memory CD8 + T cells that has been shown to regulate T cell function in models of viral infection and autoimmunity. In this article, we show that 2B4 signaling mediates sepsis lymphocyte dysfunction and mortality. 2B4 expression is increased on CD4 + T cells in septic animals and human patients at early time points. Importantly, genetic loss or pharmacologic inhibition of 2B4 significantly increased survival in a murine cecal ligation and puncture model. Further, CD4-specific conditional knockouts showed that 2B4 functions on CD4 + T cell populations in a cell-intrinsic manner and modulates adaptive and innate immune responses during sepsis. Our results illuminate a novel role for 2B4 coinhibitory signaling on CD4 + T cells in mediating immune dysregulation. Copyright © 2017 by The American Association of Immunologists, Inc.

Selective modulation of the CD4 molecular complex by Pseudomonas aeruginosa alkaline protease and elastase

DEFF Research Database (Denmark)

Pedersen, B K; Kharazmi, A; Theander, T G

1987-01-01

The binding of monoclonal antibodies against CD4 was specifically inhibited by treatment of human CD4+ cells with either alkaline protease (AP) or elastase (Ela), purified from Pseudomonas aeruginosa. Binding of antibodies against CD3 (pan T), CD5 (pan T), CD8 (T suppressor/cytotoxic), HLA-ABC, HLA......-DR, HLA-DQ, HLA-DP/DR, and beta 2 microglobulin was not inhibited by AP or Ela. Heat-inactivation of the proteases at 65 degrees C for 20 min or treatment with the metal chelator EDTA abolished the inhibitory activity of both proteases. These findings may serve to develop novel immunological methods...

The effects of intermittent, CD4-guided antiretroviral therapy on body composition and metabolic parameters

NARCIS (Netherlands)

Martinez, Esteban; Visnegarwala, Fehmida; Grund, Birgit; Thomas, Avis; Gibert, Cynthia; Shlay, Judith; Drummond, Fraser; Pearce, Daniel; Edwards, Simon; Reiss, Peter; El-Sadr, Wafaa; Carr, Andrew

2010-01-01

Objective: To assess the effects of decreased antiretroviral therapy exposure on body fat and metabolic parameters. Design: Substudy of the Strategies for Management of Anti-Retroviral Therapy study, in which participants were randomized to intermittent CD4-guided [Drug Conservation (DC) group] or

Milk-derived GM3 and GD3 differentially inhibit dendritic cell maturation and effector functionalities

DEFF Research Database (Denmark)

Brønnum, H.; Seested, T.; Hellgren, Lars

2005-01-01

value of gangliosides in breast milk has yet to be elucidated but when milk is ingested, dietary gangliosides might conceptually affect immune cells, such as dendritic cells (DCs). In this study, we address the in vitro effect of GD(3) and GM(3) on DC effector functionalities. Treatment of bone marrow......Gangliosides are complex glycosphingolipids, which exert immune-modulating effects on various cell types. Ganglioside GD(3) and GM(3) are the predominant gangliosides of human breast milk but during the early phase of lactation, the content of GD(3) decreases while GM(3) increases. The biological...... by GM(3,) and the potency of DCs to activate CD4(+) cells in MLR was unaffected by GM(3). However, both gangliosides suppressed expression of CD40, CD80, CD86 and major histocompatibility complex class II on DCs. Because GD(3) overall inhibits DC functionalities more than GM(3), the immune modulating...

Milk-derived GM(3) and GD(3) differentially inhibit dendritic cell maturation and effector functionalities

DEFF Research Database (Denmark)

Bronnum, H.; Seested, T.; Hellgren, Lars

2005-01-01

value of gangliosides in breast milk has yet to be elucidated but when milk is ingested, dietary gangliosides might conceptually affect immune cells, such as dendritic cells (DCs). In this study, we address the in vitro effect of GD(3) and GM(3) on DC effector functionalities. Treatment of bone marrow......Gangliosides are complex glycosphingolipids, which exert immune-modulating effects on various cell types. Ganglioside GD(3) and GM(3) are the predominant gangliosides of human breast milk but during the early phase of lactation, the content of GD(3) decreases while GM(3) increases. The biological...... by GM(3,) and the potency of DCs to activate CD4(+) cells in MLR was unaffected by GM(3). However, both gangliosides suppressed expression of CD40, CD80, CD86 and major histocompatibility complex class II on DCs. Because GD(3) overall inhibits DC functionalities more than GM(3), the immune modulating...

CD4(+)and CD8(+)T-cell reactions against leukemia-associated- or minor-histocompatibility-antigens in AML-patients after allogeneic SCT.

Science.gov (United States)

Steger, Brigitte; Milosevic, Slavoljub; Doessinger, Georg; Reuther, Susanne; Liepert, Anja; Braeu, Marion; Schick, Julia; Vogt, Valentin; Schuster, Friedhelm; Kroell, Tanja; Busch, Dirk H; Borkhardt, Arndt; Kolb, Hans-Jochem; Tischer, Johanna; Buhmann, Raymund; Schmetzer, Helga

2014-04-01

T-cells play an important role in the remission-maintenance in AML-patients (pts) after SCT, however the role of LAA- (WT1, PR1, PRAME) or minor-histocompatibility (mHag, HA1) antigen-specific CD4(+) and CD8(+)T-cells is not defined. A LAA/HA1-peptide/protein stimulation, cloning and monitoring strategy for specific CD8(+)/CD4(+)T-cells in AML-pts after SCT is given. Our results show that (1) LAA-peptide-specific CD8+T-cells are detectable in every AML-pt after SCT. CD8(+)T-cells, recognizing two different antigens detectable in 5 of 7 cases correlate with long-lasting remissions. Clonal TCR-Vβ-restriction exemplarily proven by spectratyping in PRAME-specific CD8(+)T-cells; high PRAME-peptide-reactivity was CD4(+)-associated, as shown by IFN-γ-release. (2) Two types of antigen-presenting cells (APCs) were tested for presentation of LAA/HA1-proteins to CD4(+)T-cells: miniEBV-transduced lymphoblastoid cells (B-cell-source) and CD4-depleted MNC (source for B-cell/monocyte/DC). We provide a refined cloning-system for proliferating, CD40L(+)CD4(+)T-cells after LAA/HA1-stimulation. CD4(+)T-cells produced cytokines (GM-CSF, IFN-γ) upon exposure to LAA/HA1-stimulation until after at least 7 restimulations and demonstrated cytotoxic activity against naive blasts, but not fibroblasts. Antileukemic activity of unstimulated, stimulated or cloned CD4(+)T-cells correlated with defined T-cell-subtypes and the clinical course of the disease. In conclusion we provide immunological tools to enrich and monitor LAA/HA1-CD4(+)- and CD8(+)T-cells in AML-pts after SCT and generate data with relevant prognostic value. We were able to demonstrate the presence of LAA-peptide-specific CD8(+)T-cell clones in AML-pts after SCT. In addition, we were also able to enrich specific antileukemic reactive CD4(+)T-cells without GvH-reactivity upon repeated LAA/HA1-protein stimulation and limiting dilution cloning. Copyright © 2013 Elsevier GmbH. All rights reserved.

CD4+ T‐cell activation is differentially modulated by bacteria‐primed dendritic cells, but is generally down‐regulated by n‐3 polyunsaturated fatty acids

DEFF Research Database (Denmark)

Pedersen, Susanne Brix; Lund, Pia; Kjær, Tanja

2010-01-01

provided by dendritic cells (DCs). Upon interaction with DCs primed by different concentrations and species of gut bacteria, CD4+ T cells were activated according to the type of DC stimulus. The levels of CD80 were found to correlate to the levels of expression of CD28 and to the proliferation of CD4+ T......, thereby affecting and shaping activation of acquired immunity by differential regulation of proliferation and costimulatory molecule expression in CD4+ T cells....

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

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

2015-07-01

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

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

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......-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......(+), but not CD8(+) CD3(+) T cells. The capacity of Zanolimumab to deplete the CD4(+) T cells in the skin may be of importance in diseases where CD4(+) T cells play a central role. Indeed, in a phase II clinical trial Zanolimumab has shown a dose-dependent clinical response in patients with CTCL and the antibody...

Exposure of a distinct PDCA-1+ (CD317 B cell population to agonistic anti-4-1BB (CD137 inhibits T and B cell responses both in vitro and in vivo.

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Dass S Vinay

Full Text Available 4-1BB (CD137 is an important T cell activating molecule. Here we report that it also promotes development of a distinct B cell subpopulation co-expressing PDCA-1. 4-1BB is expressed constitutively, and its expression is increased when PDCA-1(+ B cells are activated. We found that despite a high level of surface expression of 4-1BB on PDCA-1(+ B cells, treatment of these cells with agonistic anti-4-1BB mAb stimulated the expression of only a few activation markers (B7-2, MHC II, PD-L2, cytokines (IL-12p40/p70, and chemokines (MCP-1, RANTES, as well as sTNFR1, and the immunosuppressive enzyme, IDO. Although the PDCA-1(+ B cells stimulated by anti-4-1BB expressed MHC II at high levels and took up antigens efficiently, Ig class switching was inhibited when they were pulsed with T-independent (TI or T-dependent (TD Ags and adoptively transferred into syngeneic recipients. Furthermore, when anti-4-1BB-treated PDCA-1(+ B cells were pulsed with OVA peptide and combined with Vα2(+CD4(+ T cells, Ag-specific cell division was inhibited both in vitro and in vivo. Our findings suggest that the 4-1BB signal transforms PDCA-1(+ B cells into propagators of negative immune regulation, and establish an important role for 4-1BB in PDCA-1(+ B cell development and function.

Role of 4-1BB receptor in the control played by CD8(+ T cells on IFN-gamma production by Mycobacterium tuberculosis antigen-specific CD4(+ T Cells.

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Carla Palma

Full Text Available BACKGROUND: Antigen-specific IFN-gamma producing CD4(+ T cells are the main mediators of protection against Mycobacterium tuberculosis infection both under natural conditions and following vaccination. However these cells are responsible for lung damage and poor vaccine efficacy when not tightly controlled. Discovering new tools to control nonprotective antigen-specific IFN-gamma production without affecting protective IFN-gamma is a challenge in tuberculosis research. METHODS AND FINDINGS: Immunization with DNA encoding Ag85B, a candidate vaccine antigen of Mycobacterium tuberculosis, elicited in mice a low but protective CD4(+ T cell-mediated IFN-gamma response, while in mice primed with DNA and boosted with Ag85B protein a massive increase in IFN-gamma response was associated with loss of protection. Both protective and non-protective Ag85B-immunization generated antigen-specific CD8(+ T cells which suppressed IFN-gamma-secreting CD4(+ T cells. However, ex vivo ligation of 4-1BB, a member of TNF-receptor super-family, reduced the massive, non-protective IFN-gamma responses by CD4(+ T cells in protein-boosted mice without affecting the low protective IFN-gamma-secretion in mice immunized with DNA. This selective inhibition was due to the induction of 4-1BB exclusively on CD8(+ T cells of DNA-primed and protein-boosted mice following Ag85B protein stimulation. The 4-1BB-mediated IFN-gamma inhibition did not require soluble IL-10, TGF-beta, XCL-1 and MIP-1beta. In vivo Ag85B stimulation induced 4-1BB expression on CD8(+ T cells and in vivo 4-1BB ligation reduced the activation, IFN-gamma production and expansion of Ag85B-specific CD4(+ T cells of DNA-primed and protein-boosted mice. CONCLUSION/SIGNIFICANCE: Antigen-specific suppressor CD8(+ T cells are elicited through immunization with the mycobacterial antigen Ag85B. Ligation of 4-1BB receptor further enhanced their suppressive activity on IFN-gamma-secreting CD4(+ T cells. The selective

Mannosyl Glycodendritic Structure Inhibits DC-SIGN-Mediated Ebola Virus Infection in cis and in trans

OpenAIRE

Lasala, Fátima; Arce, Eva; Otero, Joaquín R.; Rojo, Javier; Delgado, Rafael

2003-01-01

We have designed a glycodendritic structure, BH30sucMan, that blocks the interaction between dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN) and Ebola virus (EBOV) envelope. BH30sucMan inhibits DC-SIGN-mediated EBOV infection at nanomolar concentrations. BH30sucMan may counteract important steps of the infective process of EBOV and, potentially, of microorganisms shown to exploit DC-SIGN for cell entry and infection.

Mannosyl Glycodendritic Structure Inhibits DC-SIGN-Mediated Ebola Virus Infection in cis and in trans

Science.gov (United States)

Lasala, Fátima; Arce, Eva; Otero, Joaquín R.; Rojo, Javier; Delgado, Rafael

2003-01-01

We have designed a glycodendritic structure, BH30sucMan, that blocks the interaction between dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN) and Ebola virus (EBOV) envelope. BH30sucMan inhibits DC-SIGN-mediated EBOV infection at nanomolar concentrations. BH30sucMan may counteract important steps of the infective process of EBOV and, potentially, of microorganisms shown to exploit DC-SIGN for cell entry and infection. PMID:14638512

Increased frequency of CD8+ and CD4+ regulatory T cells in chronic lymphocytic leukemia: association with disease progression.

Science.gov (United States)

Jadidi-Niaragh, Farhad; Yousefi, Mehdi; Memarian, Ali; Hojjat-Farsangi, Mohammad; Khoshnoodi, Jalal; Razavi, Seyed Mohsen; Jeddi-Tehrani, Mahmood; Shokri, Fazel

2013-02-01

Little is known regarding the immunobiology of regulatory T (Treg) cells in hematopoietic malignancies, particularly in chronic lymphocytic leukemia (CLL). In the present study, we showed that the frequencies of CD8(+) and CD4(+) Treg cells were significantly increased in progressive as compared with indolent CLL patients and normal subjects. Enriched CD4(+) Treg cells induced a similar level of inhibition in polyclonally activated B cells and effector T cells from CLL patients and normal subjects. Our results suggest that the increase in circulating Treg cells may result in downregulation of tumor-specific immune response, leading to tumor expansion and disease progression.

Per a 10 protease activity modulates CD40 expression on dendritic cell surface by nuclear factor-kappaB pathway.

Science.gov (United States)

Goel, C; Kalra, N; Dwarakanath, B S; Gaur, S N; Arora, N

2015-05-01

Serine protease activity of Per a 10 from Periplaneta americana modulates dendritic cell (DC) functions by a mechanism(s) that remains unclear. In the present study, Per a 10 protease activity on CD40 expression and downstream signalling was evaluated in DCs. Monocyte-derived DCs from cockroach-allergic patients were treated with proteolytically active/heat-inactivated Per a 10. Stimulation with active Per a 10 demonstrated low CD40 expression on DCs surface (P Per a 10, suggesting cleavage of CD40. Per a 10 activity reduced the interleukin (IL)-12 and interferon (IFN)-γ secretion by DCs (P Per a 10, indicating that low CD40 expression is associated with low levels of IL-12 secretion. Active Per a 10 stimulation caused low nuclear factor-kappa B (NF-κB) activation in DCs compared to heat-inactivated Per a 10. Inhibition of the NF-κB pathway suppressed the CD40 expression and IL-12 secretion by DCs, further indicating that NF-κB is required for CD40 up-regulation. CD40 expression activated the tumour necrosis factor (TNF) receptor-associated factor 6 (TRAF6), thereby suggesting its involvement in NF-κB activation. Protease activity of Per a 10 induced p38 mitogen-activated protein kinase (MAPK) activation that showed no significant effect on CD40 expression by DCs. However, inhibiting p38 MAPK or NF-κB suppressed the secretion of IL-12, IFN-γ, IL-6 and TNF-α by DCs. Such DCs further reduced the secretion of IL-4, IL-6, IL-12 and TNF-α by CD4(+) T cells. In conclusion, protease activity of Per a 10 reduces CD40 expression on DCs. CD40 down-regulation leads to low NF-κB levels, thereby modulating DC-mediated immune responses. © 2014 British Society for Immunology.

Therapeutic Effect of CD4+CD25+ Regulatory T Cells Amplified In Vitro on Experimental Autoimmune Neuritis in Rats

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Feng-Jie Wang

2018-05-01

Full Text Available Background/Aims: This study aimed to explore whether the adoptive transfusion of autologous CD4+CD25+ regulatory T cells (CD4+CD25+ Tregs has a therapeutic effect on Experimental autoimmune neuritis (EAN model rats, and it provides new experimental and theoretical bases for the immunotherapy of Guillain-Barre syndrome (GBS. Methods: CD4+CD25+ Tregs were sorted from the spleens of rats using immunomagnetic bead separation techniques combined with flow cytometry. Their in vitro inhibitory function was determined using a lymphocyte proliferation inhibition test, and their purity was confirmed by flow cytometry. Cells were stimulated using CD3/CD28 monoclonal antibodies and were cultured in culture medium containing interleukin 2 (IL-2, transforming growth factor-β (TGF-β and rapamycin. After 15 days of amplification, CD4+CD25+ Tregs were collected and transfused into EAN model rats. Changes in the pathology and electron microscopical morphology of rat sciatic nerves in the normal group, untreated group, low-dose group (2 × 107 and high-dose group (4 × 107 were observed, and the expression of CD4+CD25+FOXP3 in peripheral blood in the four groups of rats was detected by flow cytometry. Results: Compared with rats in the untreated group, rats in the treatment groups had significantly reduced infiltration of inflammatory cells in the sciatic nerve, as well as myelin and axonal damage. Additionally, the CD4+CD25+ Tregs levels in peripheral blood were significantly higher than those in the untreated group (P< 0. 05. Moreover, the therapeutic effect became more significant with an increase in the dose of adoptive transfusion. Conclusion: Adoptive transfusion of CD4+CD25+ Tregs into EAN model rats has significant therapeutic effects.

Both CD4+ and CD8+ Lymphocytes Participate in the IFN-γ Response to Filamentous Hemagglutinin from Bordetella pertussis in Infants, Children, and Adults

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Violette Dirix

2012-01-01

Full Text Available Infant CD4+ T-cell responses to bacterial infections or vaccines have been extensively studied, whereas studies on CD8+ T-cell responses focused mainly on viral and intracellular parasite infections. Here we investigated CD8+ T-cell responses upon Bordetella pertussis infection in infants, children, and adults and pertussis vaccination in infants. Filamentous hemagglutinin-specific IFN-γ secretion by circulating lymphocytes was blocked by anti-MHC-I or -MHC-II antibodies, suggesting that CD4+ and CD8+ T lymphocytes are involved in IFN-γ production. Flow cytometry analyses confirmed that both cell types synthesized antigen-specific IFN-γ, although CD4+ lymphocytes were the major source of this cytokine. IFN-γ synthesis by CD8+ cells was CD4+ T cell dependent, as evidenced by selective depletion experiments. Furthermore, IFN-γ synthesis by CD4+ cells was sometimes inhibited by CD8+ lymphocytes, suggesting the presence of CD8+ regulatory T cells. The role of this dual IFN-γ secretion by CD4+ and CD8+ T lymphocytes in pertussis remains to be investigated.

Nanoparticles containing siRNA to silence CD4 and CCR5 reduce expression of these receptors and inhibit HIV-1 infection in human female reproductive tract tissue explants

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Susan K. Eszterhas

2011-09-01

Full Text Available Human Immunodeficiency Virus-type 1 (HIV- 1 binds to CD4 and CCR5 receptors on target cells in the human female reproductive tract. We sought to determine whether reducing levels of messenger RNA (mRNA transcripts that encode these receptors in female reproductive tract cells could protect mucosal tissue explants from HIV- 1 infection. Explants prepared from the endometrium, endocervix, and ectocervix of hysterectomy tissues from HIV-1 sero-negative women were exposed to nanoparticles containing CD4- and CCR5-specific short-interfering RNA (siRNA sequences. Explants were then exposed two days later to HIV-1, and HIV-1 reverse transcripts were measured five days post-infection. Explants treated with nanoparticles containing CD4- and CCR5-specific siRNA showed reduced levels of CD4 and CCR5 transcripts, and significantly lower levels of HIV-1 reverse transcripts compared to those treated with an irrelevant siRNA. In female reproductive tract explants and in peripheral blood cell cultures, siRNA transfection induced the secretion of IFN-alpha (IFN-α, a potent antiviral cytokine. In female mice, murine-specific Cd4-siRNA nanoparticles instilled within the uterus significantly reduced murine Cd4 transcripts by day 3. Our findings demonstrate that siRNA nanoparticles reduce expression of HIV-1 infectivity receptors in human female reproductive tract tissues and also inhibit HIV-1 infection. Murine studies demonstrate that nanoparticles can penetrate the reproductive tract tissues in vivo and silence gene expression. The induction of IFN-α after siRNA transfection can potentially contribute to the antiviral effect. These findings support the therapeutic development of nanoparticles to deliver siRNA molecules to silence host cell receptors in the female reproductive tract as a novel microbicide to inhibit mucosal HIV-1 transmission.

Human umbilical cord-derived mesenchymal stem cells suppress proliferation of PHA-activated lymphocytes in vitro by inducing CD4(+)CD25(high)CD45RA(+) regulatory T cell production and modulating cytokine secretion.

Science.gov (United States)

Yang, Hongna; Sun, Jinhua; Li, Yan; Duan, Wei-Ming; Bi, Jianzhong; Qu, Tingyu

2016-04-01

Bone marrow-derived mesenchymal stem cells (MSCs) are promising candidate cells for therapeutic application in autoimmune diseases due to their immunomodulatory properties. Unused human umbilical cords (UC) offer an abundant and noninvasive source of MSCs without ethical issues and are emerging as a valuable alternative to bone marrow tissue for producing MSCs. We thus investigated the immunomodulation effect of umbilical cord-derived MSCs (UC-MSCs) on human peripheral blood mononuclear cells (PBMCs), T cells in particular, in a co-culture system. We found that UC-MSCs efficiently suppressed the proliferation of phytohaemagglutinin (PHA)-stimulated PBMCs (pMSCs primarily inhibited the division of generation 3 (G3) and 4 (G4) of PBMCs. In addition, UC-MSCs augmented the expression of CD127(+) and CD45RA(+) but reduced the expression of CD25(+) in PBMCs stimulated by PHA (pMSCs inhibited PHA-resulted increase in the frequency of CD4(+)CD25(+)CD127(low/-) Tregs significantly (pMSCs are able to suppress mitogen-induced PBMC activation and proliferation in vitro by altering T lymphocyte phenotypes, increasing the frequency of CD4(+)CD25(high)CD45RA(+) Tregs, and modulating the associated cytokine production. Further studies are warranted to investigate the therapeutic potential of UC-MSCs in immunologically-diseased conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

Kaempferol regulates OPN–CD44 pathway to inhibit the atherogenesis of apolipoprotein E deficient mice

International Nuclear Information System (INIS)

Xiao, Hong-Bo; Lu, Xiang-Yang; Sun, Zhi-Liang; Zhang, Heng-Bo

2011-01-01

Recent studies show that osteopontin (OPN) and its receptor cluster of differentiation 44 (CD44) are two pro-inflammatory cytokines contributing to the development of atherosclerosis. The objective of this study was to explore the inhibitory effect of kaempferol, a naturally occurring flavonoid compound, on atherogenesis and the mechanisms involved. The experiments were performed in aorta and plasma from C57BL/6J control and apolipoprotein E-deficient (ApoE −/− ) mice treated or not with kaempferol (50 or 100 mg/kg, intragastrically) for 4 weeks. Kaempferol treatment decreased atherosclerotic lesion area, improved endothelium-dependent vasorelaxation, and increased the maximal relaxation value concomitantly with decrease in the half-maximum effective concentration, plasma OPN level, aortic OPN expression, and aortic CD44 expression in ApoE −/− mice. In addition, treatment with kaempferol also significantly decreased reactive oxygen species production in mice aorta. The present results suggest that kaempferol regulates OPN–CD44 pathway to inhibit the atherogenesis of ApoE −/− mice. -- Graphical abstract: Kaempferol regulates OPN–CD44 pathway to inhibit the atherogenesis of ApoE −/− mice. Highlights: ► OPN–CD44 pathway plays a critical role in the development of atherosclerosis. ► We examine lesion area, OPN and CD44 changes after kaempferol treatment. ► Kaempferol treatment decreased atherosclerotic lesion area in ApoE −/− mice. ► Kaempferol treatment decreased aortic OPN and CD44 expressions in ApoE −/− mice. ► Kaempferol regulates OPN–CD44 pathway to inhibit the atherogenesis.

Kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis of apolipoprotein E deficient mice

Energy Technology Data Exchange (ETDEWEB)

Xiao, Hong-Bo, E-mail: xhbzhb@yahoo.com [College of Veterinary Medicine, Hunan Agricultural University, Changsha 410128 (China); Lu, Xiang-Yang; Sun, Zhi-Liang [Hunan Agricultural University, Changsha 410128 (China); Zhang, Heng-Bo [Furong District Red Cross Hospital, Changsha 410126 (China)

2011-12-15

Recent studies show that osteopontin (OPN) and its receptor cluster of differentiation 44 (CD44) are two pro-inflammatory cytokines contributing to the development of atherosclerosis. The objective of this study was to explore the inhibitory effect of kaempferol, a naturally occurring flavonoid compound, on atherogenesis and the mechanisms involved. The experiments were performed in aorta and plasma from C57BL/6J control and apolipoprotein E-deficient (ApoE{sup -/-}) mice treated or not with kaempferol (50 or 100 mg/kg, intragastrically) for 4 weeks. Kaempferol treatment decreased atherosclerotic lesion area, improved endothelium-dependent vasorelaxation, and increased the maximal relaxation value concomitantly with decrease in the half-maximum effective concentration, plasma OPN level, aortic OPN expression, and aortic CD44 expression in ApoE{sup -/-} mice. In addition, treatment with kaempferol also significantly decreased reactive oxygen species production in mice aorta. The present results suggest that kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis of ApoE{sup -/-} mice. -- Graphical abstract: Kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis of ApoE{sup -/-} mice. Highlights: Black-Right-Pointing-Pointer OPN-CD44 pathway plays a critical role in the development of atherosclerosis. Black-Right-Pointing-Pointer We examine lesion area, OPN and CD44 changes after kaempferol treatment. Black-Right-Pointing-Pointer Kaempferol treatment decreased atherosclerotic lesion area in ApoE{sup -/-} mice. Black-Right-Pointing-Pointer Kaempferol treatment decreased aortic OPN and CD44 expressions in ApoE{sup -/-} mice. Black-Right-Pointing-Pointer Kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis.

Task-shifting of CD4 T cell count monitoring by the touchscreen-based Muse™ Auto CD4/CD4% single-platform system for CD4 T cell numeration: Implication for decentralization in resource-constrained settings.

Science.gov (United States)

Kouabosso, André; Mossoro-Kpinde, Christian Diamant; Bouassa, Ralph-Sydney Mboumba; Longo, Jean De Dieu; Mbeko Simaleko, Marcel; Grésenguet, Gérard; Bélec, Laurent

2018-04-01

The accuracy of CD4 T cell monitoring by the recently developed flow cytometry-based CD4 T cell counting Muse™ Auto CD4/CD4% Assay analyzer (EMD Millipore Corporation, Merck Life Sciences, KGaA, Darmstadt, Germany) was evaluated in trained lay providers against laboratory technicians. After 2 days of training on the Muse™ Auto CD4/CD4% analyzer, EDTA-blood samples from 6 HIV-positive and 4 HIV-negative individuals were used for CD4 T cell counting in triplicate in parallel by 12 trained lay providers as compared to 10 lab technicians. Mean number of CD4 T cells in absolute number was 829 ± 380 cells/μl by lay providers and 794 ± 409 cells/μl by technicians (P > 0.05); and in percentage 36.2 ± 14.8%CD4 by lay providers and 36.1 ± 15.0%CD4 by laboratory technician (P > 0.05). The unweighted linear regression and Passing-Bablok regression analyses on CD4 T cell results expressed in absolute count revealed moderate correlation between CD4 T cell counts obtained by lay providers and lab technicians. The mean absolute bias measured by Bland-Altman analysis between CD4 T cell/μl obtained by lay providers and lab technicians was -3.41 cells/μl. Intra-assay coefficient of variance (CV) of Muse™ Auto CD4/CD4% in absolute number was 10.1% by lay providers and 8.5% by lab technicians (P > 0.05), and in percentage 5.5% by lay providers and 4.4% by lab technicians (P > 0.05). The inter-assay CV of Muse™ Auto CD4/CD4% in absolute number was 13.4% by lay providers and 10.3% by lab technicians (P > 0.05), and in percentage 7.8% by lay providers and 6.9% by lab technicians (P > 0.05). The study demonstrates the feasibility of CD4 T cell counting using the alternative flow cytometer Muse™ Auto CD4/CD4% analyzer by trained lay providers and therefore the practical possibility of decentralization CD4 T cell counting to health community centers. Copyright © 2018. Published by Elsevier B.V.

CD38 gene-modified dendritic cells inhibit murine asthma development by increasing IL-12 production and promoting Th1 cell differentiation.

Science.gov (United States)

Wang, Jiaoli; Zhu, Weiguo; Chen, Yinghu; Lin, Zhendong; Ma, Shenglin

2016-11-01

Predominant T helper (Th)2 and impaired Th1 cell polarization has a crucial role in the development of asthma. Cluster of differentiation (CD)38 is associated with the increased release of interleukin (IL)‑12 from dendritic cells (DCs) and DC‑induced Th1 cell polarization. However, whether CD38 expression affects DC function in asthma development remains unknown. In the current study, adenoviruses were constructed containing the murine CD38 gene. Overexpression of CD38 protein level in DCs induced from bone‑marrow derived DCs (BMDCs) by recombinant mouse granulocyte macrophage colony‑stimulating factor and IL‑4 was achieved through 24 h adenovirus infection. The results demonstrated that BMDCs with CD38 overexpression exhibited no phenotypic change; however, following stimulation with lipopolysaccharide (LPS), maturation and IL‑12 secretion were increased. In addition, CD38‑overexpressing BMDCs stimulated with LPS exhibited more effective Th1 cell differentiation. Mice that were administered CD38‑overexpressing BMDCs exhibited milder symptoms of asthma. Furthermore, decreased IL‑4, IL‑5 and IL‑13 levels were detected in bronchoalveolar lavage fluid (BALF), reduced immunoglobulin E levels were measured in the sera, and increased interferon‑γ was detected in BALF from the recipients of CD38‑overexpressing BMDCs. Increased phosphorylated‑p38 expression was also detected in LPS-stimulated CD38-overexpressing BMDCs, whereas pretreatment with a p38‑specific inhibitor was able to abolish the effects of LPS stimulation and CD38 overexpression on IL‑12 release and Th1 cell differentiation in BMDCs. These results suggested that CD38 may be involved in the DC function of alleviating asthma via restoration of the Th1/Th2 balance, thus providing a novel strategy for asthma therapy.

Distinct and overlapping effector functions of expanded human CD4+, CD8α+ and CD4-CD8α- invariant natural killer T cells.

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Vincent O'Reilly

Full Text Available CD1d-restricted invariant natural killer T (iNKT cells have diverse immune stimulatory/regulatory activities through their ability to release cytokines and to kill or transactivate other cells. Activation of iNKT cells can protect against multiple diseases in mice but clinical trials in humans have had limited impact. Clinical studies to date have targeted polyclonal mixtures of iNKT cells and we proposed that their subset compositions will influence therapeutic outcomes. We sorted and expanded iNKT cells from healthy donors and compared the phenotypes, cytotoxic activities and cytokine profiles of the CD4(+, CD8α(+ and CD4(-CD8α(- double-negative (DN subsets. CD4(+ iNKT cells expanded more readily than CD8α(+ and DN iNKT cells upon mitogen stimulation. CD8α(+ and DN iNKT cells most frequently expressed CD56, CD161 and NKG2D and most potently killed CD1d(+ cell lines and primary leukemia cells. All iNKT subsets released Th1 (IFN-γ and TNF-α and Th2 (IL-4, IL-5 and IL-13 cytokines. Relative amounts followed a CD8α>DN>CD4 pattern for Th1 and CD4>DN>CD8α for Th2. All iNKT subsets could simultaneously produce IFN-γ and IL-4, but single-positivity for IFN-γ or IL-4 was strikingly rare in CD4(+ and CD8α(+ fractions, respectively. Only CD4(+ iNKT cells produced IL-9 and IL-10; DN cells released IL-17; and none produced IL-22. All iNKT subsets upregulated CD40L upon glycolipid stimulation and induced IL-10 and IL-12 secretion by dendritic cells. Thus, subset composition of iNKT cells is a major determinant of function. Use of enriched CD8α(+, DN or CD4(+ iNKT cells may optimally harness the immunoregulatory properties of iNKT cells for treatment of disease.

The major surface glycoprotein (gp63) from Leishmania major and Leishmania donovani cleaves CD4 molecules on human T cells

DEFF Research Database (Denmark)

Hey, A S; Theander, T G; Hviid, L

1994-01-01

The effect of Leishmania major and L. donovani surface protease gp63 on surface markers on human T cells was studied using fluorescence-activated flow cytometry. Purified gp63 (63,000 m.w. glycoprotein) at concentrations above 10 micrograms/ml completely inhibited binding of six different anti-CD4......-expression of CD4, reaching 50% of the initial level after 72 h of incubation in medium. Preincubation of cells with live promastigotes showed an inhibitory effect on CD4 comparable to that seen with purified gp63. The binding of Abs directed against other surface markers present on human T-cells--CD2, CD3, CD5......, CD8, CD11A, CD25, CD45RO, CD45RA, CD58, TCR-alpha, TCR-gamma, and HLA DQ--was not inhibited by gp63. These data suggest that gp63, both in its purified form and in the form anchored to the parasite membrane, cleaves CD4 on human T cells. The cleavage of CD4 by the protease might play a role...

21 CFR 74.1254 - D&C Orange No. 4.

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2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false D&C Orange No. 4. 74.1254 Section 74.1254 Food and... ADDITIVES SUBJECT TO CERTIFICATION Drugs § 74.1254 D&C Orange No. 4. (a) Identity. (1) the color additive D&C Orange No. 4 is principally the sodium salt of 4-[(2-hydroxy-1-naphthalenyl)azo]benzenesulfonic...

Association of CD147 and Calcium Exporter PMCA4 Uncouples IL-2 Expression from Early TCR Signaling.

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Supper, Verena; Schiller, Herbert B; Paster, Wolfgang; Forster, Florian; Boulègue, Cyril; Mitulovic, Goran; Leksa, Vladimir; Ohradanova-Repic, Anna; Machacek, Christian; Schatzlmaier, Philipp; Zlabinger, Gerhard J; Stockinger, Hannes

2016-02-01

The Ig superfamily member CD147 is upregulated following T cell activation and was shown to serve as a negative regulator of T cell proliferation. Thus, Abs targeting CD147 are being tested as new treatment strategies for cancer and autoimmune diseases. How CD147 mediates immunosuppression and whether association with other coreceptor complexes is needed have remained unknown. In the current study, we show that silencing of CD147 in human T cells increases IL-2 production without affecting the TCR proximal signaling components. We mapped the immunosuppressive moieties of CD147 to its transmembrane domain and Ig-like domain II. Using affinity purification combined with mass spectrometry, we determined the domain specificity of CD147 interaction partners and identified the calcium exporter plasma membrane calcium ATPase isoform 4 (PMCA4) as the interaction partner of the immunosuppressive moieties of CD147. CD147 does not control the proper membrane localization of PMCA4, but PMCA4 is essential for the CD147-dependent inhibition of IL-2 expression via a calcium-independent mechanism. In summary, our data show that CD147 interacts via its immunomodulatory domains with PMCA4 to bypass TCR proximal signaling and inhibit IL-2 expression. Copyright © 2016 by The American Association of Immunologists, Inc.

Human CD141+ Dendritic Cell and CD1c+ Dendritic Cell Undergo Concordant Early Genetic Programming after Activation in Humanized Mice In Vivo

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Yoshihito Minoda

2017-10-01

Full Text Available Human immune cell subsets develop in immunodeficient mice following reconstitution with human CD34+ hematopoietic stem cells. These “humanized” mice are useful models to study human immunology and human-tropic infections, autoimmunity, and cancer. However, some human immune cell subsets are unable to fully develop or acquire full functional capacity due to a lack of cross-reactivity of many growth factors and cytokines between species. Conventional dendritic cells (cDCs in mice are categorized into cDC1, which mediate T helper (Th1 and CD8+ T cell responses, and cDC2, which mediate Th2 and Th17 responses. The likely human equivalents are CD141+ DC and CD1c+ DC subsets for mouse cDC1 and cDC2, respectively, but the extent of any interspecies differences is poorly characterized. Here, we exploit the fact that human CD141+ DC and CD1c+ DC develop in humanized mice, to further explore their equivalency in vivo. Global transcriptome analysis of CD141+ DC and CD1c+ DC isolated from humanized mice demonstrated that they closely resemble those in human blood. Activation of DC subsets in vivo, with the TLR3 ligand poly I:C, and the TLR7/8 ligand R848 revealed that a core panel of genes consistent with DC maturation status were upregulated by both subsets. R848 specifically upregulated genes associated with Th17 responses by CD1c+ DC, while poly I:C upregulated IFN-λ genes specifically by CD141+ DC. MYCL expression, known to be essential for CD8+ T cell priming by mouse DC, was specifically induced in CD141+ DC after activation. Concomitantly, CD141+ DC were superior to CD1c+ DC in their ability to prime naïve antigen-specific CD8+ T cells. Thus, CD141+ DC and CD1c+ DC share a similar activation profiles in vivo but also have induce unique signatures that support specialized roles in CD8+ T cell priming and Th17 responses, respectively. In combination, these data demonstrate that humanized mice provide an attractive and tractable model to study

Alzheimer's disease risk gene CD33 inhibits microglial uptake of amyloid beta.

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Griciuc, Ana; Serrano-Pozo, Alberto; Parrado, Antonio R; Lesinski, Andrea N; Asselin, Caroline N; Mullin, Kristina; Hooli, Basavaraj; Choi, Se Hoon; Hyman, Bradley T; Tanzi, Rudolph E

2013-05-22

The transmembrane protein CD33 is a sialic acid-binding immunoglobulin-like lectin that regulates innate immunity but has no known functions in the brain. We have previously shown that the CD33 gene is a risk factor for Alzheimer's disease (AD). Here, we observed increased expression of CD33 in microglial cells in AD brain. The minor allele of the CD33 SNP rs3865444, which confers protection against AD, was associated with reductions in both CD33 expression and insoluble amyloid beta 42 (Aβ42) levels in AD brain. Furthermore, the numbers of CD33-immunoreactive microglia were positively correlated with insoluble Aβ42 levels and plaque burden in AD brain. CD33 inhibited uptake and clearance of Aβ42 in microglial cell cultures. Finally, brain levels of insoluble Aβ42 as well as amyloid plaque burden were markedly reduced in APP(Swe)/PS1(ΔE9)/CD33(-/-) mice. Therefore, CD33 inactivation mitigates Aβ pathology and CD33 inhibition could represent a novel therapy for AD. Copyright © 2013 Elsevier Inc. All rights reserved.

21 CFR 74.2254 - D&C Orange No. 4.

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2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false D&C Orange No. 4. 74.2254 Section 74.2254 Food and... ADDITIVES SUBJECT TO CERTIFICATION Cosmetics § 74.2254 D&C Orange No. 4. (a) Identity and specifications. The color additive D&C Orange No. 4 shall conform in identity and specifications to the requirements...

Percentages of CD4+CD161+ and CD4−CD8−CD161+ T Cells in the Synovial Fluid Are Correlated with Disease Activity in Rheumatoid Arthritis

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Jinlin Miao

2015-01-01

Full Text Available Objective. CD161 has been identified as a marker of human IL-17-producing T cells that are implicated in the pathogenesis of rheumatoid arthritis (RA. This study aimed to investigate the potential link between the percentage of CD161+ T cells and disease activity in RA patients. Methods. Peripheral blood (PB from 54 RA patients and 21 healthy controls was evaluated. Paired synovial fluid (SF (n = 17 was analyzed. CD161 expression levels on CD4+, CD8+, and CD4−CD8− T cells were assessed by flow cytometry. Results. The percentage of CD4+CD161+ T cells in RA SF was higher than RA PB, and it was positively correlated with DAS28, erythrocyte sedimentation rate (ESR, and C-reactive protein (CRP. CD4−CD8−CD161+ T cell percentage was decreased in RA PB and was further reduced in RA SF, and its level in SF was inversely correlated with DAS28, ESR, and CRP. However, CD8+CD161+ T cell percentage was neither changed in RA PB and SF nor correlated with disease activity indices. Conclusion. An increased CD4+CD161+ T cell percentage and a decreased CD4−CD8−CD161+ T cell percentage are present in RA SF and are associated with disease activity, and the accumulation of CD4+CD161+ T cells in SF may contribute to the local inflammation of RA.

CD4+ T helper cells and regulatory T cells in active lupus nephritis: an imbalance towards a predominant Th1 response?

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Mesquita, D; Kirsztajn, G Mastroianni; Franco, M F; Reis, L A; Perazzio, S F; Mesquita, F V; Ferreira, V da Silva; Andrade, L E Coelho; de Souza, A W Silva

2018-01-01

The objective of this study was to evaluate the frequency of CD4 + T cell subsets in peripheral blood mononuclear cells (PBMC), urine and renal tissue from patients with lupus nephritis (LN). PBMC and urinary cells were collected from 17 patients with active LN, 20 disease controls (DC) with primary glomerulonephritis and 10 healthy controls (HC) and were analysed by flow cytometry with markers for T helper type 1 (Th1), Th2, Th17 and regulatory T cells (T reg ) cells. T cell subsets were assessed by immunohistochemistry from LN biopsy specimens from 12 LN patients. T cell subtypes in PBMC were re-evaluated at 6 months of therapy. CD4 + T cells were decreased in PBMC in LN compared with DC and HC (P = 0·0001). No differences were observed in urinary CD4 + T cell subsets between LN and DC. The frequency of urinary Th17 cells was higher in patients with non-proliferative than in proliferative LN (P = 0·041). CD3 + and T-box 21 ( Tbet+) cells were found in glomeruli and interstitium of LN patients, while forkhead box protein 3 (FoxP3), retinoid-related orphan receptor gamma (ROR-γ) and GATA binding protein 3 (GATA-3) were present only in glomeruli. Th1 cells in PBMC were correlated negatively with urinary Th1 cells (Rho = -0·531; P = 0·028) and with T bet in renal interstitium (Rho = -0·782; P = 0·004). At 6 months, LN patients showed an increase in Th17 cells in PBMC. In conclusion, the inverse association between Th1 cells from PBMC and urinary/renal tissue indicate a role for Th1 in LN pathophysiology. Urinary Th17 cells were associated with less severe LN, and Th17 increased in PBMC during therapy. Urinary CD4 + T cells were not different between LN and DC. © 2017 British Society for Immunology.

Optoelectronic properties of R-F magnetron sputtered Cadmium Tin Oxide (Cd2SnO4) thin films for CdS/CdTe thin film solar cell applications

International Nuclear Information System (INIS)

Jeyadheepan, K.; Thamilselvan, M.; Kim, Kyunghae; Yi, Junsin; Sanjeeviraja, C.

2015-01-01

Highlights: • Characterization of “as-prepared” Cd 2 SnO 4 thin films ideal for thin film solar cells. • Lowest value of resistivity with high mobility attained for the as-prepared Cd 2 SnO 4 films. • Maximum transmittance of 93% in the visible range for the as-prepared films. • Effect of substrate temperature on the scattering mechanism of TCO. - Abstract: The influence of substrate temperature on the microstructural behavior, optical, electrical properties and on the scattering mechanism of charge carriers were studied for the as-prepared radio-frequency (R-F) magnetron sputtered Cadmium Tin Oxide (Cd 2 SnO 4 ) thin films. Films prepared at the substrate temperature of 300 °C were found to be polycrystalline in nature with preferential orientation along (3 1 1) plane. Well pronounced Moss–Burstein shift, in the transmittance spectra with dispersions in the optical band gap from 3.07 to 3.30 eV, was observed at substrate temperatures between 25 and 300 °C. Optical property of high visible transmittance was retained by the films. Analysis of the electrical properties on the prepared crystalline Cd 2 SnO 4 films showed a calculated resistivity of 10 −3 –10 −4 Ω cm, with n-type carrier density in the range of 10 19 –10 20 cm −3 and the charge carrier mobility in the range of 63–30 cm 2 /V s. The effects of structural, compositional and optical properties on the scattering mechanism of charge carrier are elaborated and reported to be an experimental evidence for the theoretical predictions. The results revealed the essential DC electrical conduction behavior, which is ideal for the fabrication of Cd 2 SnO 4 -based CdS/CdTe thin film solar cells

Atorvastatin inhibits the immediate-early response gene EGR1 and improves the functional profile of CD4+T-lymphocytes in acute coronary syndromes.

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Severino, Anna; Zara, Chiara; Campioni, Mara; Flego, Davide; Angelini, Giulia; Pedicino, Daniela; Giglio, Ada Francesca; Trotta, Francesco; Giubilato, Simona; Pazzano, Vincenzo; Lucci, Claudia; Iaconelli, Antonio; Ruggio, Aureliano; Biasucci, Luigi Marzio; Crea, Filippo; Liuzzo, Giovanna

2017-03-14

Background- Adaptive immune-response is associated with a worse outcome in acute coronary syndromes. Statins have anti-inflammatory activity beyond lowering lipid levels. We investigated the effects of ex-vivo and in-vivo atorvastatin treatment in acute coronary syndromes on CD4+T-cells, and the underlying molecular mechanisms.Approach and results- Blood samples were collected from 50 statin-naïve acute coronary syndrome patients. We assessed CD4+T-cell activation by flow-cytometry, the expression of 84 T-helper transcription-factors and 84 T-cell related genes by RT-qPCR, and protein expression by Western-blot, before and after 24-hours incubation with increasing doses of atorvastatin: 3-10-26 μg/ml (corresponding to blood levels achieved with doses of 10-40-80 mg, respectively). After incubation, we found a significant decrease in interferon-γ-producing CD4+CD28nullT-cells (P = 0.009) and a significant increase in interleukin-10-producing CD4+CD25highT-cells (P 3-fold changes).The in-vivo effects of atorvastatin were analyzed in 10 statin-free acute coronary syndrome patients at baseline, and after 24h and 48h of atorvastatin therapy (80 mg/daily): EGR1-gene expression decreased at 24h (P = 0.01) and 48h (P = 0.005); EGR1-protein levels decreased at 48h (P = 0.03).Conclusions-In acute coronary syndromes, the effects of atorvastatin on immune system might be partially related to the inhibition of the master regulator gene EGR1. Our finding might offer a causal explanation on why statins improve the early outcome in acute coronary syndromes.

B7-H4 Treatment of T Cells Inhibits ERK, JNK, p38, and AKT Activation.

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Xiaojie Wang

Full Text Available B7-H4 is a newly identified B7 homolog that plays an important role in maintaining T-cell homeostasis by inhibiting T-cell proliferation and lymphokine-secretion. In this study, we investigated the signal transduction pathways inhibited by B7-H4 engagement in mouse T cells. We found that treatment of CD3(+ T cells with a B7-H4.Ig fusion protein inhibits anti-CD3 elicited T-cell receptor (TCR/CD28 signaling events, including phosphorylation of the MAP kinases, ERK, p38, and JNK. B7-H4.Ig treatment also inhibited the phosphorylation of AKT kinase and impaired its kinase activity as assessed by the phosphorylation of its endogenous substrate GSK-3. Expression of IL-2 is also reduced by B7-H4. In contrast, the phosphorylation state of the TCR proximal tyrosine kinases ZAP70 and lymphocyte-specific protein tyrosine kinase (LCK are not affected by B7-H4 ligation. These results indicate that B7-H4 inhibits T-cell proliferation and IL-2 production through interfering with activation of ERK, JNK, and AKT, but not of ZAP70 or LCK.

CML/CD36 accelerates atherosclerotic progression via inhibiting foam cell migration.

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Xu, Suining; Li, Lihua; Yan, Jinchuan; Ye, Fei; Shao, Chen; Sun, Zhen; Bao, Zhengyang; Dai, Zhiyin; Zhu, Jie; Jing, Lele; Wang, Zhongqun

2018-01-01

Among the various complications of type 2 diabetes mellitus, atherosclerosis causes the highest disability and morbidity. A multitude of macrophage-derived foam cells are retained in atherosclerotic plaques resulting not only from recruitment of monocytes into lesions but also from a reduced rate of macrophage migration from lesions. Nε-carboxymethyl-Lysine (CML), an advanced glycation end product, is responsible for most complications of diabetes. This study was designed to investigate the mechanism of CML/CD36 accelerating atherosclerotic progression via inhibiting foam cell migration. In vivo study and in vitro study were performed. For the in vivo investigation, CML/CD36 accelerated atherosclerotic progression via promoting the accumulation of macrophage-derived foam cells in aorta and inhibited macrophage-derived foam cells in aorta migrating to the para-aorta lymph node of diabetic apoE -/- mice. For the in vitro investigation, CML/CD36 inhibited RAW264.7-derived foam cell migration through NOX-derived ROS, FAK phosphorylation, Arp2/3 complex activation and F-actin polymerization. Thus, we concluded that CML/CD36 inhibited foam cells of plaque migrating to para-aorta lymph nodes, accelerating atherosclerotic progression. The corresponding mechanism may be via free cholesterol, ROS generation, p-FAK, Arp2/3, F-actin polymerization. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

LAP TGF-Beta Subset of CD4+CD25+CD127− Treg Cells is Increased and Overexpresses LAP TGF-Beta in Lung Adenocarcinoma Patients

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Islas-Vazquez, Lorenzo; Aguilar-Cazares, Dolores; Meneses-Flores, Manuel; Galicia-Velasco, Miriam; Romero-Garcia, Susana; Camacho-Mendoza, Catalina; Lopez-Gonzalez, Jose Sullivan

2015-01-01

Lung cancer is the leading cause of cancer death worldwide. Adenocarcinoma, the most commonly diagnosed histologic type of lung cancer, is associated with smoking. Cigarette smoke promotes inflammation on the airways, which might be mediated by Th17 cells. This inflammatory environment may contribute to tumor development. In contrast, some reports indicate that tumors may induce immunosuppressive Treg cells to dampen immune reactivity, supporting tumor growth and progression. Thus, we aimed to analyze whether chronic inflammation or immunosuppression predominates at the systemic level in lung adenocarcinoma patients, and several cytokines and Th17 and Treg cells were studied. Higher proportions of IL-17-producing CD4+ T-cells were found in smoking control subjects and in lung adenocarcinoma patients compared to nonsmoking control subjects. In addition, lung adenocarcinoma patients increased both plasma concentrations of IL-2, IL-4, IL-6, and IL-10, and proportions of Latency Associated Peptide (LAP) TGF-β subset of CD4+CD25+CD127− Treg cells, which overexpressed LAP TGF-β. This knowledge may lead to the development of immunotherapies that could inhibit the suppressor activity mediated by the LAP TGF-β subset of CD4+CD25+CD127− Treg cells to promote reactivity of immune cells against lung adenocarcinoma cells. PMID:26582240

LAP TGF-Beta Subset of CD4+CD25+CD127− Treg Cells is Increased and Overexpresses LAP TGF-Beta in Lung Adenocarcinoma Patients

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Lorenzo Islas-Vazquez

2015-01-01

Full Text Available Lung cancer is the leading cause of cancer death worldwide. Adenocarcinoma, the most commonly diagnosed histologic type of lung cancer, is associated with smoking. Cigarette smoke promotes inflammation on the airways, which might be mediated by Th17 cells. This inflammatory environment may contribute to tumor development. In contrast, some reports indicate that tumors may induce immunosuppressive Treg cells to dampen immune reactivity, supporting tumor growth and progression. Thus, we aimed to analyze whether chronic inflammation or immunosuppression predominates at the systemic level in lung adenocarcinoma patients, and several cytokines and Th17 and Treg cells were studied. Higher proportions of IL-17-producing CD4+ T-cells were found in smoking control subjects and in lung adenocarcinoma patients compared to nonsmoking control subjects. In addition, lung adenocarcinoma patients increased both plasma concentrations of IL-2, IL-4, IL-6, and IL-10, and proportions of Latency Associated Peptide (LAP TGF-β subset of CD4+CD25+CD127− Treg cells, which overexpressed LAP TGF-β. This knowledge may lead to the development of immunotherapies that could inhibit the suppressor activity mediated by the LAP TGF-β subset of CD4+CD25+CD127− Treg cells to promote reactivity of immune cells against lung adenocarcinoma cells.

21 CFR 82.1254 - D&C Orange No. 4.

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2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false D&C Orange No. 4. 82.1254 Section 82.1254 Food and... PROVISIONALLY LISTED COLORS AND SPECIFICATIONS Drugs and Cosmetics § 82.1254 D&C Orange No. 4. The color additive D&C Orange No. 4 shall conform in identity and specifications to the requirements of § 74.1254(a...

Tumor-Targeted Human T Cells Expressing CD28-Based Chimeric Antigen Receptors Circumvent CTLA-4 Inhibition.

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Maud Condomines

Full Text Available Adoptive T cell therapy represents a promising treatment for cancer. Human T cells engineered to express a chimeric antigen receptor (CAR recognize and kill tumor cells in a MHC-unrestricted manner and persist in vivo when the CAR includes a CD28 costimulatory domain. However, the intensity of the CAR-mediated CD28 activation signal and its regulation by the CTLA-4 checkpoint are unknown. We investigated whether T cells expressing an anti-CD19, CD3 zeta and CD28-based CAR (19-28z displayed the same proliferation and anti-tumor abilities than T cells expressing a CD3 zeta-based CAR (19z1 costimulated through the CD80/CD28, ligand/receptor pathway. Repeated in vitro antigen-specific stimulations indicated that 19-28z+ T cells secreted higher levels of Th1 cytokines and showed enhanced proliferation compared to those of 19z1+ or 19z1-CD80+ T cells. In an aggressive pre-B cell leukemia model, mice treated with 19-28z+ T cells had 10-fold reduced tumor progression compared to those treated with 19z1+ or 19z1-CD80+ T cells. shRNA-mediated CTLA-4 down-regulation in 19z1-CD80+ T cells significantly increased their in vivo expansion and anti-tumor properties, but had no effect in 19-28z+ T cells. Our results establish that CTLA-4 down-regulation may benefit human adoptive T cell therapy and demonstrate that CAR design can elude negative checkpoints to better sustain T cell function.

Human dendritic cells sequentially matured with CD4(+) T cells as a secondary signal favor CTL and long-term T memory cell responses.

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Simon, Thomas; Tanguy-Royer, Séverine; Royer, Pierre-Joseph; Boisgerault, Nicolas; Frikeche, Jihane; Fonteneau, Jean-François; Grégoire, Marc

2012-01-01

Dendritic cells (DCs) are professional antigen-presenting cells involved in the control and initiation of immune responses. In vivo, DCs exposed at the periphery to maturation stimuli migrate to lymph nodes, where they receive secondary signals from CD4+ T helper cells. These DCs become able to initiate CD8+ cytotoxic T lymphocyte (CTL) responses. However, in vitro investigations concerning human monocyte-derived DCs have never focused on their functional properties after such sequential maturation. Here, we studied human DC phenotypes and functions according to this sequential exposure to maturation stimuli. As first signals, we used TNF-α/polyI:C mimicking inflammatory and pathogen stimuli and, as second signals, we compared activated CD4+ T helper cells to a combination of CD40-L/ IFN-γ. Our results show that a sequential activation with activated CD4+ T cells dramatically increased the maturation of DCs in terms of their phenotype and cytokine secretion compared to DCs activated with maturation stimuli delivered simultaneously. Furthermore, this sequential maturation led to the induction of CTL with a long-term effector and central memory phenotypes. Thus, sequential delivery of maturation stimuli, which includes CD4+ T cells, should be considered in the future to improve the induction of long-term CTL memory in DC-based immunotherapy.

Notch controls the survival of memory CD4+ T cells by regulating glucose uptake.

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Maekawa, Yoichi; Ishifune, Chieko; Tsukumo, Shin-ichi; Hozumi, Katsuto; Yagita, Hideo; Yasutomo, Koji

2015-01-01

CD4+ T cells differentiate into memory T cells that protect the host from subsequent infection. In contrast, autoreactive memory CD4+ T cells harm the body by persisting in the tissues. The underlying pathways controlling the maintenance of memory CD4+ T cells remain undefined. We show here that memory CD4+ T cell survival is impaired in the absence of the Notch signaling protein known as recombination signal binding protein for immunoglobulin κ J region (Rbpj). Treatment of mice with a Notch inhibitor reduced memory CD4+ T cell numbers and prevented the recurrent induction of experimental autoimmune encephalomyelitis. Rbpj-deficient CD4+ memory T cells exhibit reduced glucose uptake due to impaired AKT phosphorylation, resulting in low Glut1 expression. Treating mice with pyruvic acid, which bypasses glucose uptake and supplies the metabolite downstream of glucose uptake, inhibited the decrease of autoimmune memory CD4+ T cells in the absence of Notch signaling, suggesting memory CD4+ T cell survival relies on glucose metabolism. Together, these data define a central role for Notch signaling in maintaining memory CD4+ T cells through the regulation of glucose uptake.

Therapeutic effects of anti-CD115 monoclonal antibody in mouse cancer models through dual inhibition of tumor-associated macrophages and osteoclasts.

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Laetitia Fend

Full Text Available Tumor progression is promoted by Tumor-Associated Macrophages (TAMs and metastasis-induced bone destruction by osteoclasts. Both myeloid cell types depend on the CD115-CSF-1 pathway for their differentiation and function. We used 3 different mouse cancer models to study the effects of targeting cancer host myeloid cells with a monoclonal antibody (mAb capable of blocking CSF-1 binding to murine CD115. In mice bearing sub-cutaneous EL4 tumors, which are CD115-negative, the anti-CD115 mAb depleted F4/80(+ CD163(+ M2-type TAMs and reduced tumor growth, resulting in prolonged survival. In the MMTV-PyMT mouse model, the spontaneous appearance of palpable mammary tumors was delayed when the anti-CD115 mAb was administered before malignant transition and tumors became palpable only after termination of the immunotherapy. When administered to mice already bearing established PyMT tumors, anti-CD115 treatment prolonged their survival and potentiated the effect of chemotherapy with Paclitaxel. As shown by immunohistochemistry, this therapeutic effect correlated with the depletion of F4/80(+CD163(+ M2-polarized TAMs. In a breast cancer model of bone metastasis, the anti-CD115 mAb potently blocked the differentiation of osteoclasts and their bone destruction activity. This resulted in the inhibition of cancer-induced weight loss. CD115 thus represents a promising target for cancer immunotherapy, since a specific blocking antibody may not only inhibit the growth of a primary tumor through TAM depletion, but also metastasis-induced bone destruction through osteoclast inhibition.

Decreased HIV-specific T-regulatory responses are associated with effective DC-vaccine induced immunity.

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Vedran Brezar

2015-03-01

Full Text Available The role of regulatory T cells (Tregs in vaccination has been poorly investigated. We have reported that vaccination with ex vivo-generated dendritic-cells (DC loaded with HIV-lipopeptides (LIPO-5-DC vaccine in HIV-infected patients was well tolerated and highly immunogenic. These responses and their relation to viral replication following analytical treatment interruption (ATI were variable. Here, we investigated whether the presence of HIV-specific Tregs might explain these differences. Co-expression of CD25, CD134, CD39 and FoxP3 was used to delineate both antigen-specific Tregs and effectors T cells (Teffs. Median LIPO-5 specific-CD25+CD134+ polyfunctional T cells increased from 0.1% (IQR 0-0.3 before vaccination (week -4 to 2.1% (IQR 1.1-3.9 at week 16 following 4 immunizations (p=0.001 and were inversely correlated with maximum viral load following ATI (r=-0.77, p=0.001. Vaccinees who displayed lower levels of HIV-specific CD4+CD134+CD25+CD39+FoxP3+ Tregs responded better to the LIPO-5-DC vaccine. After vaccination, the frequency of HIV-specific Tregs decreased (from 69.3 at week -4 to 31.7% at week 16 and inversely correlated with HIV-specific IFN-γ-producing cells (r=-0.64, p=0.002. We show that therapeutic immunization skewed the HIV-specific response from regulatory to effector phenotype which impacts on the magnitude of viral replication following ATI.

Forsythoside A Inhibits BVDV Replication via TRAF2-Dependent CD28-4-1BB Signaling in Bovine PBMCs.

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Quan-Jiang Song

Full Text Available Bovine viral diarrhea virus (BVDV, the causative agent of bovine viral diarrhea/mucosal disease (BVD/MD, is an important pathogen of cattle and other wild animals throughout the world. BVDV infection typically leads to an impaired immune response in cattle. In the present study, we investigated the effect of Forsythoside A (FTA on BVDV infection of bovine peripheral blood mononuclear cells (PBMCs. We found that Forsythoside A could not only promote proliferation of PBMCs and T cells activation but also inhibit the replication of BVDV as well as apoptosis induced by BVDV. FTA treatment could counteract the BVDV-induced overproduction of IFN-γ to maintain the immune homeostasis in bovine PBMCs. At same time, FTA can enhance the secretion of IL-2. What's more, BVDV promotes the expression of CD28, 4-1BB and TRAF-2, which can be modulated by FTA. Our data suggest that FTA protects PBMCs from BVDV infection possibly via TRAF2-dependent CD28-4-1BB signaling, which may activate PBMCs in response to BVDV infection. Therefore, this aids in the development of an effective adjuvant for vaccines against BVDV and other specific FTA-based therapies for preventing BVDV infection.

HuMax-CD4

DEFF Research Database (Denmark)

Skov, Lone; Kragballe, Knud; Zachariae, Claus

2003-01-01

BACKGROUND: Psoriasis is characterized by infiltration with mononuclear cells. Especially activated memory CD4+ T cells are critical in the pathogenesis. Interaction between the CD4 receptor and the major histocompatibility complex class II molecule is important for T-cell activation. OBJECTIVE......: To test safety and efficacy of a fully human monoclonal anti-CD4 antibody (HuMax-CD4) in the treatment of psoriasis. DESIGN: Multicenter, double-blind, placebo-controlled, randomized clinical trial. Patients Eighty-five patients with moderate to severe psoriasis. INTERVENTIONS: Subcutaneous infusions...... dose level, 6 (38%) of 16 patients obtained more than 25% reduction of PASI and 3 (19%) obtained more than 50% reduction of PASI. A dose-dependent decrease in total lymphocyte count was seen and was parallel to a dose-dependent decrease in CD4+ T cells. This decrease was due to a decrease in the memory...

A Novel Toll-Like Receptor 9 Agonist, MGN1703, Enhances HIV-1 Transcription and NK Cell-Mediated Inhibition of HIV-1-Infected Autologous CD4+ T Cells.

Science.gov (United States)

Offersen, Rasmus; Nissen, Sara Konstantin; Rasmussen, Thomas A; Østergaard, Lars; Denton, Paul W; Søgaard, Ole Schmeltz; Tolstrup, Martin

2016-05-01

Toll-like receptor (TLR) agonists are potent enhancers of innate antiviral immunity and may also reverse HIV-1 latency. Therefore, TLR agonists have a potential role in the context of a "shock-and-kill" approach to eradicate HIV-1. Our extensive preclinical evaluation suggests that a novel TLR9 agonist, MGN1703, may indeed perform both functions in an HIV-1 eradication trial. Peripheral blood mononuclear cells (PBMCs) from aviremic HIV-1-infected donors on antiretroviral therapy (ART) that were incubated with MGN1703 ex vivo exhibited increased secretion of interferon alpha (IFN-α) (P= 0.005) and CXCL10 (P= 0.0005) in culture supernatants. Within the incubated PBMC pool, there were higher proportions of CD69-positive CD56(dim)CD16(+)NK cells (P= 0.001) as well as higher proportions of CD107a-positive (P= 0.002) and IFN-γ-producing (P= 0.038) NK cells. Incubation with MGN1703 also increased the proportions of CD69-expressing CD4(+)and CD8(+)T cells. Furthermore, CD4(+)T cells within the pool of MGN1703-incubated PBMCs showed enhanced levels of unspliced HIV-1 RNA (P= 0.036). Importantly, MGN1703 increased the capacity of NK cells to inhibit virus spread within a culture of autologous CD4(+)T cells assessed by using an HIV-1 p24 enzyme-linked immunosorbent assay (ELISA) (P= 0.03). In conclusion, we show that MGN1703 induced strong antiviral innate immune responses, enhanced HIV-1 transcription, and boosted NK cell-mediated suppression of HIV-1 infection in autologous CD4(+)T cells. These findings support clinical testing of MGN1703 in HIV-1 eradication trials. We demonstrate that MGN1703 (a TLR9 agonist currently undergoing phase 3 clinical testing for the treatment of metastatic colorectal cancer) induces potent antiviral responses in immune effector cells from HIV-1-infected individuals on suppressive antiretroviral therapy. The significantly improved safety and tolerability profiles of MGN1703 versus TLR9 agonists of the CpG-oligodeoxynucleotide (CpG-ODN) family

Fusion proteins of HIV-1 envelope glycoprotein gp120 with CD4-induced antibodies showed enhanced binding to CD4 and CD4 binding site antibodies

Energy Technology Data Exchange (ETDEWEB)

Chen, Weizao, E-mail: chenw3@mail.nih.gov [Protein Interactions Group, Frederick National Laboratory for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States); Feng, Yang [Protein Interactions Group, Frederick National Laboratory for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States); Wang, Yanping [Protein Interactions Group, Frederick National Laboratory for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States); The Basic Research Program, Science Applications International Corporation-Frederick, Inc., National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States); Zhu, Zhongyu; Dimitrov, Dimiter S. [Protein Interactions Group, Frederick National Laboratory for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States)

2012-09-07

Highlights: Black-Right-Pointing-Pointer Some recombinant HIV-1 gp120s do not preserve their conformations on gp140s. Black-Right-Pointing-Pointer We hypothesize that CD4i antibodies could induce conformational changes in gp120. Black-Right-Pointing-Pointer CD4i antibodies enhance binding of CD4 and CD4bs antibodies to gp120. Black-Right-Pointing-Pointer CD4i antibody-gp120 fusion proteins could have potential as vaccine immunogens. -- Abstract: Development of successful AIDS vaccine immunogens continues to be a major challenge. One of the mechanisms by which HIV-1 evades antibody-mediated neutralizing responses is the remarkable conformational flexibility of its envelope glycoprotein (Env) gp120. Some recombinant gp120s do not preserve their conformations on gp140s and functional viral spikes, and exhibit decreased recognition by CD4 and neutralizing antibodies. CD4 binding induces conformational changes in gp120 leading to exposure of the coreceptor-binding site (CoRbs). In this study, we test our hypothesis that CD4-induced (CD4i) antibodies, which target the CoRbs, could also induce conformational changes in gp120 leading to better exposed conserved neutralizing antibody epitopes including the CD4-binding site (CD4bs). We found that a mixture of CD4i antibodies with gp120 only weakly enhanced CD4 binding. However, such interactions in single-chain fusion proteins resulted in gp120 conformations which bound to CD4 and CD4bs antibodies better than the original or mutagenically stabilized gp120s. Moreover, the two molecules in the fusion proteins synergized with each other in neutralizing HIV-1. Therefore, fusion proteins of gp120 with CD4i antibodies could have potential as components of HIV-1 vaccines and inhibitors of HIV-1 entry, and could be used as reagents to explore the conformational flexibility of gp120 and mechanisms of entry and immune evasion.

Azidothymidine Sensitizes Primary Effusion Lymphoma Cells to Kaposi Sarcoma-Associated Herpesvirus-Specific CD4+ T Cell Control and Inhibits vIRF3 Function.

Directory of Open Access Journals (Sweden)

Samantha J Williamson

2016-11-01

Full Text Available Kaposi sarcoma-associated herpesvirus (KSHV is linked with the development of Kaposi sarcoma and the B lymphocyte disorders primary effusion lymphoma (PEL and multi-centric Castleman disease. T cell immunity limits KSHV infection and disease, however the virus employs multiple mechanisms to inhibit efficient control by these effectors. Thus KSHV-specific CD4+ T cells poorly recognize most PEL cells and even where they can, they are unable to kill them. To make KSHV-infected cells more sensitive to T cell control we treated PEL cells with the thymidine analogue azidothymidine (AZT, which sensitizes PEL lines to Fas-ligand and TRAIL challenge; effector mechanisms which T cells use. PELs co-cultured with KSHV-specific CD4+ T cells in the absence of AZT showed no control of PEL outgrowth. However in the presence of AZT PEL outgrowth was controlled in an MHC-restricted manner. To investigate how AZT sensitizes PELs to immune control we first examined BJAB cells transduced with individual KSHV-latent genes for their ability to resist apoptosis mediated by stimuli delivered through Fas and TRAIL receptors. This showed that in addition to the previously described vFLIP protein, expression of vIRF3 also inhibited apoptosis delivered by these stimuli. Importantly vIRF3 mediated protection from these apoptotic stimuli was inhibited in the presence of AZT as was a second vIRF3 associated phenotype, the downregulation of surface MHC class II. Although both vFLIP and vIRF3 are expressed in PELs, we propose that inhibiting vIRF3 function with AZT may be sufficient to restore T cell control of these tumor cells.

Human CD4 restores normal T cell development and function in mice deficient in murine CD4

OpenAIRE

1994-01-01

The ability of a human coreceptor to function in mice was investigated by generating human CD4 (hCD4)-expressing transgenic mice on a mouse CD4-deficient (mCD4-/-) background. From developing thymocyte to matured T lymphocyte functions, hCD4 was shown to be physiologically active. By examining the expansion and deletion of specific V beta T cell families in mutated mice with and without hCD4, it was found that hCD4 can participate in positive and negative selection. Mature hCD4 single positiv...

Sulforaphane inhibits osteoclast differentiation by suppressing the cell-cell fusion molecules DC-STAMP and OC-STAMP

International Nuclear Information System (INIS)

Takagi, Tomohiro; Inoue, Hirofumi; Takahashi, Nobuyuki; Katsumata-Tsuboi, Rie; Uehara, Mariko

2017-01-01

Sulforaphane (SFN), a kind of isothiocyanate, is derived from broccoli sprouts. It has anti-tumor, anti-inflammatory, and anti-oxidation activity. The molecular function of SFN in the inhibition of osteoclast differentiation is not well-documented. In this study, we assessed the effect of SFN on osteoclast differentiation in vitro. SFN inhibited osteoclast differentiation in both bone marrow cells and RAW264.7 cells. Key molecules involved in the inhibitory effects of SFN on osteoclast differentiation were determined using a microarray analysis, which showed that SFN inhibits osteoclast-associated genes, such as osteoclast-associated receptor (OSCAR), nuclear factor of activated T cells cytoplasmic-1, tartrate-resistant acid phosphatase, and cathepsin K. Moreover, the mRNA expression levels of the cell-cell fusion molecules dendritic cell specific transmembrane protein (DC-STAMP) and osteoclast stimulatory transmembrane protein (OC-STAMP) were strongly suppressed in cells treated with SFN. Furthermore, SFN increased the phosphorylation of signal transducer and activator of transcription 1 (STAT1), a regulator of macrophage and osteoclast cell fusion. Thus, our data suggested that SFN significantly inhibits the cell-cell fusion molecules DC-STAMP and OC-STAMP by inducing the phosphorylation of STAT1 (Tyr701), which might be regulated by interactions with OSCAR. - Highlights: • Sulforaphane inhibited osteoclast differentiation and osteoclast cell-fusion. • Sulforaphane suppressed not only NFATc1, but also cell-cell fusion molecules, DC-STAMP and OC-STAMP. • Sulforaphane decreased multinucleated osteoclasts, whereas increased mono-nucleated osteoclasts. • Sulforaphane inhibits the cell-cell fusion by inducing the phosphorylation of STAT1 (Tyr701).

Targeting CD4(+) T-Helper Cells Improves the Induction of Antitumor Responses in Dendritic Cell-Based Vaccination

NARCIS (Netherlands)

Aarntzen, Erik H. J. G.; de Vries, I. Jolanda M.; Lesterhuis, W. Joost; Schuurhuis, Danita; Jacobs, Joannes F. M.; Bol, Kalijn; Schreibelt, Gerty; Mus, Roel; de Wilt, Johannes H. W.; Haanen, John B. A. G.; Schadendorf, Dirk; Croockewit, Alexandra; Blokx, Willeke A. M.; van Rossum, Michelle M.; Kwok, William W.; Adema, Gosse J.; Punt, Cornelis J. A.; Figdor, Carl G.

2013-01-01

To evaluate the relevance of directing antigen-specific CD4(+) T helper cells as part of effective anticancer immunotherapy, we investigated the immunologic and clinical responses to vaccination with dendritic cells (DC) pulsed with either MHC class I (MHC-I)-restricted epitopes alone or both MHC

IL-22-producing CD4(+) T cells: Middle-men between the immune system and its environment

NARCIS (Netherlands)

Trifari, Sara; Spits, Hergen

2010-01-01

CD4(+) Th cell populations such as Th1, Th2, Th17 and regulatory T cells regulate immune responses by inducing (or inhibiting) proliferation, differentiation and activation of other immune cells. Recent findings have expanded the universe of CD4(+) T-cell subsets by identifying a cell population

Effects of Inhibiting Dipeptidyl Peptidase-4 (DPP4 in Cows with Subclinical Ketosis.

Directory of Open Access Journals (Sweden)

Kirsten Schulz

Full Text Available The inhibition of dipeptidyl peptidase-4 (DPP4 via specific inhibitors is known to result in improved glucose tolerance and insulin sensitivity and decreased accumulation of hepatic fat in type II diabetic human patients. The metabolic situation of dairy cows can easily be compared to the status of human diabetes and non-alcoholic fatty liver. For both, insulin sensitivity is reduced, while hepatic fat accumulation increases, characterized by high levels of non-esterified fatty acids (NEFA and ketone bodies.Therefore, in the present study, a DPP4 inhibitor was employed (BI 14332 for the first time in cows. In a first investigation BI 14332 treatment (intravenous injection at dosages of up to 3 mg/kg body weight was well tolerated in healthy lactating pluriparous cows (n = 6 with a significant inhibition of DPP4 in plasma and liver. Further testing included primi- and pluriparous lactating cows suffering from subclinical ketosis (β-hydroxybutyrate concentrations in serum > 1.2 mM; n = 12. The intension was to offer effects of DPP4 inhibition during comprehensive lipomobilisation and hepatosteatosis. The cows of subclinical ketosis were evenly allocated to either the treatment group (daily injections, 0.3 mg BI 14332/kg body weight, 7 days or the control group. Under condition of subclinical ketosis, the impact of DPP4 inhibition via BI 14332 was less, as in particular β-hydroxybutyrate and the hepatic lipid content remained unaffected, but NEFA and triglyceride concentrations were decreased after treatment. Owing to lower NEFA, the revised quantitative insulin sensitivity check index (surrogate marker for insulin sensitivity increased. Therefore, a positive influence on energy metabolism might be quite possible. Minor impacts on immune-modulating variables were limited to the lymphocyte CD4+/CD8+ ratio for which a trend to decreased values in treated versus control animals was noted. In sum, the DPP4 inhibition in cows did not affect glycaemic

Effects of Inhibiting Dipeptidyl Peptidase-4 (DPP4) in Cows with Subclinical Ketosis

Science.gov (United States)

Schulz, Kirsten; Frahm, Jana; Kersten, Susanne; Meyer, Ulrich; Rehage, Jürgen; Piechotta, Marion; Meyerholz, Maria; Breves, Gerhard; Reiche, Dania; Sauerwein, Helga; Dänicke, Sven

2015-01-01

The inhibition of dipeptidyl peptidase-4 (DPP4) via specific inhibitors is known to result in improved glucose tolerance and insulin sensitivity and decreased accumulation of hepatic fat in type II diabetic human patients. The metabolic situation of dairy cows can easily be compared to the status of human diabetes and non-alcoholic fatty liver. For both, insulin sensitivity is reduced, while hepatic fat accumulation increases, characterized by high levels of non-esterified fatty acids (NEFA) and ketone bodies.Therefore, in the present study, a DPP4 inhibitor was employed (BI 14332) for the first time in cows. In a first investigation BI 14332 treatment (intravenous injection at dosages of up to 3 mg/kg body weight) was well tolerated in healthy lactating pluriparous cows (n = 6) with a significant inhibition of DPP4 in plasma and liver. Further testing included primi- and pluriparous lactating cows suffering from subclinical ketosis (β-hydroxybutyrate concentrations in serum > 1.2 mM; n = 12). The intension was to offer effects of DPP4 inhibition during comprehensive lipomobilisation and hepatosteatosis. The cows of subclinical ketosis were evenly allocated to either the treatment group (daily injections, 0.3 mg BI 14332/kg body weight, 7 days) or the control group. Under condition of subclinical ketosis, the impact of DPP4 inhibition via BI 14332 was less, as in particular β-hydroxybutyrate and the hepatic lipid content remained unaffected, but NEFA and triglyceride concentrations were decreased after treatment. Owing to lower NEFA, the revised quantitative insulin sensitivity check index (surrogate marker for insulin sensitivity) increased. Therefore, a positive influence on energy metabolism might be quite possible. Minor impacts on immune-modulating variables were limited to the lymphocyte CD4+/CD8+ ratio for which a trend to decreased values in treated versus control animals was noted. In sum, the DPP4 inhibition in cows did not affect glycaemic control like

Effects of Inhibiting Dipeptidyl Peptidase-4 (DPP4) in Cows with Subclinical Ketosis.

Science.gov (United States)

Schulz, Kirsten; Frahm, Jana; Kersten, Susanne; Meyer, Ulrich; Rehage, Jürgen; Piechotta, Marion; Meyerholz, Maria; Breves, Gerhard; Reiche, Dania; Sauerwein, Helga; Dänicke, Sven

2015-01-01

The inhibition of dipeptidyl peptidase-4 (DPP4) via specific inhibitors is known to result in improved glucose tolerance and insulin sensitivity and decreased accumulation of hepatic fat in type II diabetic human patients. The metabolic situation of dairy cows can easily be compared to the status of human diabetes and non-alcoholic fatty liver. For both, insulin sensitivity is reduced, while hepatic fat accumulation increases, characterized by high levels of non-esterified fatty acids (NEFA) and ketone bodies.Therefore, in the present study, a DPP4 inhibitor was employed (BI 14332) for the first time in cows. In a first investigation BI 14332 treatment (intravenous injection at dosages of up to 3 mg/kg body weight) was well tolerated in healthy lactating pluriparous cows (n = 6) with a significant inhibition of DPP4 in plasma and liver. Further testing included primi- and pluriparous lactating cows suffering from subclinical ketosis (β-hydroxybutyrate concentrations in serum > 1.2 mM; n = 12). The intension was to offer effects of DPP4 inhibition during comprehensive lipomobilisation and hepatosteatosis. The cows of subclinical ketosis were evenly allocated to either the treatment group (daily injections, 0.3 mg BI 14332/kg body weight, 7 days) or the control group. Under condition of subclinical ketosis, the impact of DPP4 inhibition via BI 14332 was less, as in particular β-hydroxybutyrate and the hepatic lipid content remained unaffected, but NEFA and triglyceride concentrations were decreased after treatment. Owing to lower NEFA, the revised quantitative insulin sensitivity check index (surrogate marker for insulin sensitivity) increased. Therefore, a positive influence on energy metabolism might be quite possible. Minor impacts on immune-modulating variables were limited to the lymphocyte CD4+/CD8+ ratio for which a trend to decreased values in treated versus control animals was noted. In sum, the DPP4 inhibition in cows did not affect glycaemic control like

Specific interaction of CXCR4 with CD4 and CD8α: Functional analysis of the CD4/CXCR4 interaction in the context of HIV-1 envelope glycoprotein-mediated membrane fusion

International Nuclear Information System (INIS)

Basmaciogullari, Stephane; Pacheco, Beatriz; Bour, Stephan; Sodroski, Joseph

2006-01-01

We investigated possible interactions between HIV-1 receptor (CD4) and the main coreceptors CXCR4 and CCR5. We found that CD4 and CXCR4 coexpressed in 293T cells form a complex that can be immunoprecipitated with antibodies directed against the extracellular domain of either protein. Mutagenesis revealed that the CD4/CXCR4 interaction maps to two previously uncharacterized basic motifs in the cytoplasmic domain of CD4. HIV-1 envelope glycoprotein-mediated membrane fusion was found to be independent of the ability of CD4 and CXCR4 to interact, whether fusion was studied in a virus-cell or a cell-cell model. However, this interaction might explain the adaptation of HIV-1 to CXCR4 as an alternative to CCR5. We found that CXCR4 also interacts with the cytoplasmic domain of CD8α in a way that is similar to the CD4/CXCR4 interaction. The CD4/CXCR4 and CD8α/CXCR4 interactions may thus be involved in cellular signaling pathways shared by the CD4 and CD8α molecules

Alzheimer’s Disease Risk Gene CD33 Inhibits Microglial Uptake of Amyloid Beta

Science.gov (United States)

Griciuc, Ana; Serrano-Pozo, Alberto; Parrado, Antonio R.; Lesinski, Andrea N.; Asselin, Caroline N.; Mullin, Kristina; Hooli, Basavaraj; Choi, Se Hoon; Hyman, Bradley T.; Tanzi, Rudolph E.

2013-01-01

SUMMARY The transmembrane protein CD33 is a sialic acid-binding immunoglobulin-like lectin that regulates innate immunity but has no known functions in the brain. We have previously shown that the CD33 gene is a risk factor for Alzheimer’s disease (AD). Here, we observed increased expression of CD33 in microglial cells in AD brain. The minor allele of the CD33 SNP rs3865444, which confers protection against AD, was associated with reductions in both CD33 expression and insoluble amyloid beta 42 (Aβ42) levels in AD brain. Furthermore, the numbers of CD33-immunoreactive microglia were positively correlated with insoluble Aβ42 levels and plaque burden in AD brain. CD33 inhibited uptake and clearance of Aβ42 in microglial cell cultures. Finally, brain levels of insoluble Aβ42 as well as amyloid plaque burden were markedly reduced in APPSwe/PS1ΔE9/CD33−/− mice. Therefore, CD33 inactivation mitigates Aβ pathology and CD33 inhibition could represent a novel therapy for AD. PMID:23623698

HIV-1 Env and Nef Cooperatively Contribute to Plasmacytoid Dendritic Cell Activation via CD4-Dependent Mechanisms.

Science.gov (United States)

Reszka-Blanco, Natalia J; Sivaraman, Vijay; Zhang, Liguo; Su, Lishan

2015-08-01

Plasmacytoid dendritic cells (pDCs) are the major source of type I IFN (IFN-I) in response to human immunodeficiency virus type 1 (HIV-1) infection. pDCs are rapidly activated during HIV-1 infection and are implicated in reducing the early viral load, as well as contributing to HIV-1-induced pathogenesis. However, most cell-free HIV-1 isolates are inefficient in activating human pDCs, and the mechanisms of HIV-1 recognition by pDCs and pDC activation are not clearly defined. In this study, we report that two genetically similar HIV-1 variants (R3A and R3B) isolated from a rapid progressor differentially activated pDCs to produce alpha interferon (IFN-α). The highly pathogenic R3A efficiently activated pDCs to induce robust IFN-α production, while the less pathogenic R3B did not. The viral determinant for efficient pDC activation was mapped to the V1V2 region of R3A Env, which also correlated with enhanced CD4 binding activity. Furthermore, we showed that the Nef protein was also required for the activation of pDCs by R3A. Analysis of a panel of R3A Nef functional mutants demonstrated that Nef domains involved in CD4 downregulation were necessary for R3A to activate pDCs. Our data indicate that R3A-induced pDC activation depends on (i) the high affinity of R3A Env for binding the CD4 receptor and (ii) Nef activity, which is involved in CD4 downregulation. Our findings provide new insights into the mechanism by which HIV-1 induces IFN-α in pDCs, which contributes to pathogenesis. Plasmacytoid dendritic cells (pDCs) are the major type I interferon (IFN-I)-producing cells, and IFN-I actually contributes to pathogenesis during chronic viral infections. How HIV-1 activates pDCs and the roles of pDCs/IFN-I in HIV-1 pathogenesis remain unclear. We report here that the highly pathogenic HIV R3A efficiently activated pDCs to induce IFN-α production, while most HIV-1 isolates are inefficient in activating pDCs. We have discovered that R3A-induced pDC activation depends on

Human dendritic cells sequentially matured with CD4+ T cells as a secondary signal favor CTL and long-term T memory cell responses

Directory of Open Access Journals (Sweden)

Thomas Simon

2012-01-01

Full Text Available Dendritic cells (DCs are professional antigen-presenting cells involved in the control and initiation of immune responses. In vivo, DCs exposed at the periphery to maturation stimuli migrate to lymph nodes, where they receive secondary signals from CD4+ T helper cells. These DCs become able to initiate CD8+ cytotoxic T lymphocyte (CTL responses. However, in vitro investigations concerning human monocyte-derived DCs have never focused on their functional properties after such sequential maturation. Here, we studied human DC phenotypes and functions according to this sequential exposure to maturation stimuli. As first signals, we used TNF-α/polyI:C mimicking inflammatory and pathogen stimuli and, as second signals, we compared activated CD4+ T helper cells to a combination of CD40-L/ IFN-γ. Our results show that a sequential activation with activated CD4+ T cells dramatically increased the maturation of DCs in terms of their phenotype and cytokine secretion compared to DCs activated with maturation stimuli delivered simultaneously. Furthermore, this sequential maturation led to the induction of CTL with a long-term effector and central memory phenotypes. Thus, sequential delivery of maturation stimuli, which includes CD4+ T cells, should be considered in the future to improve the induction of long-term CTL memory in DC-based immunotherapy.

3-Bromopyruvate inhibits cell proliferation and induces apoptosis in CD133+ population in human glioma.

Science.gov (United States)

Xu, Dong-Qiang; Tan, Xiao-Yu; Zhang, Bao-Wei; Wu, Tao; Liu, Ping; Sun, Shao-Jun; Cao, Yin-Guang

2016-03-01

The study was aimed to investigate the role of 3-bromopyruvate in inhibition of CD133+ U87 human glioma cell population growth. The results demonstrated that 3-bromopyruvate inhibited the viability of both CD133+ and parental cells derived from U87 human glioma cell line. However, the 3-bromopyruvate-induced inhibition in viability was more prominent in CD133+ cells at 10 μM concentration after 48 h. Treatment of CD133+ cells with 3-bromopyruvate caused reduction in cell population and cell size, membrane bubbling, and degradation of cell membranes. Hoechst 33258 staining showed condensation of chromatin material and fragmentation of DNA in treated CD133+ cells after 48 h. 3-Bromopyruvate inhibited the migration rate of CD133+ cells significantly compared to the parental cells. Flow cytometry revealed that exposure of CD133+ cells to 3-bromopyruvate increased the cell population in S phase from 24.5 to 37.9 % with increase in time from 12 to 48 h. In addition, 3-bromopyruvate significantly enhanced the expression of Bax and cleaved caspase 3 in CD133+ cells compared to the parental cells. Therefore, 3-bromopyruvate is a potent chemotherapeutic agent for the treatment of glioma by targeting stem cells selectively.

Changes and clinical significance of CD4+CD25+CD127- regulatory T cells in Graves disease

International Nuclear Information System (INIS)

Zou Jintao; Yu Peiling; Dong Jingwei; Liao Qihong; Liu Dongliang; Zeng Hongyi

2012-01-01

Objective: To investigate the mechanism of Graves disease by observing the changes of CD4 + CD25 + CD127 - regulatory T cells (Treg) population in the patients. Methods: Flow cytometry was used to detect the proportion of CD4 + CD25 + CD127 - Treg of CD4 + T cells in 90 Graves disease patients (Graves disease group) and 50 healthy adults (control group). Thyroid function and autoantibody levels were determined simultaneously. The t test was adopted for comparison between groups. The relationship between CD4 + CD25 + CD127 - Treg and thyroid function was analyzed by linear correlation analysis. Results: The percentages of CD4 + CD25 + CD127 - Treg in Graves disease group and control group were 1.39%±1.09% and 4.59%±1.14% separately. There was significant difference between the two groups (t=16.4, P<0.01). There were negative correlation between CD4 + CD25 + CD127 - Treg percentages and total triiodothyronine, total thyroxine,free triiodothyronine, free thyroxine and thyrotropin receptor antibody,thyroglobulin antibody, thyroid microsomal antibody (r=-0.62, -0.65, -0.56, -0.71, -0.50, -0.15, all P<0.01). Conclusions: The reduction of CD4 + CD25 + CD127 - Treg percentages in Graves disease group and close relations of CD4 + CD25 + CD127 - Treg with thyroid function and thyroid autoantibody levels suggest that CD4 + CD25 + CD127 - Treg decrease in the number may be associated with the onset of Graves disease. CD4 + CD25 + CD127 - may be the specific marker of Treg. (authors)

Evaluation of CD4+/CD8+ status and urinary tract infections ...

African Journals Online (AJOL)

Evaluation of CD4+/CD8+ status and urinary tract infections associated with urinary schistosomiasis ... African Health Sciences ... by <50 ova /10ml of urine had a mean CD4+:CD8+ ratio of 1.57 while those with heavy infections as ... Key words: CD4+, CD8+, urinary tract infections, urinary schistosomiasis, rural Nigerians

Performance of 22.4-kW nonlaminated-frame dc series motor with chopper controller. [a dc to dc voltage converter

Science.gov (United States)

Schwab, J. R.

1979-01-01

Performance data obtained through experimental testing of a 22.4 kW traction motor using two types of excitation are presented. Ripple free dc from a motor-generator set for baseline data and pulse width modulated dc as supplied by a battery pack and chopper controller were used for excitation. For the same average values of input voltage and current, the motor power output was independent of the type of excitation. However, at the same speeds, the motor efficiency at low power output (corresponding to low duty cycle of the controller) was 5 to 10 percentage points lower on chopped dc than on ripple free dc. The chopped dc locked-rotor torque was approximately 1 to 3 percent greater than the ripple free dc torque for the same average current.

CAMEX-4 DC-8 DROPSONDE SYSTEM V1

Data.gov (United States)

National Aeronautics and Space Administration — The CAMEX-4 DC-8 Dropsonde System dataset was collected by the DC-8 Dropsonde System (D8D) uses dropwindsonde and Global Positioning System (GPS) receivers to...

Fas (CD95) expression and death-mediating function are induced by CD4 cross-linking on CD4+ T cells.

OpenAIRE

Desbarats, J; Freed, J H; Campbell, P A; Newell, M K

1996-01-01

The CD4 receptor contributes to T-cell activation by coligating major histocompatibility complex class II on antigen presenting cells with the T-cell receptor (TCR)/CD3 complex, and triggering a cascade of signaling events including tyrosine phosphorylation of intracellular proteins. Paradoxically, CD3 cross-linking prior to TCR stimulation results in apoptotic cell death, as does injection of anti-CD4 antibodies in vivo of CD4 ligation by HIV glycoprotein (gp) 120. In this report we investig...

Targeted knock down of CCL22 and CCL17 by siRNA during DC differentiation and maturation affects the recruitment of T subsets.

Science.gov (United States)

Kang, Shijun; Xie, Jianmin; Ma, Shudong; Liao, Wangjun; Zhang, Junyi; Luo, Rongcheng

2010-01-01

Chemokines secreted by DC are instrumental for DC to regulate their own migratory capacities and to recruit T lymphocytes during local tumour immune response. Using the recently developed chemokine protein arrays, we analyzed 38 chemokines associated with monocyte-derived DC (MoDC), including the CC family (CCL2, CCL3, CCL4, CCL17, CCL18, CCL22, CCL23, CCL24, CCL27) and the CXC family (CXCL3, CXCL5, CXCL7, CXCL8, CXCL16) chemokines. Our results indicate that MoDC largely inherit the chemokines constitutively expressed by monocytes, with a significant induction of CCL17, CCL22 and CCL23. Spent culture supernatant collected from MoDC exhibited chemotatic abilities to activate CD4(+), CD8(+), and CD25(+) Foxp3(+) regulatory T cells (Tregs). Selective knock down of CCL22 and CCL17 expression by siRNA decreased the ratios of CD4(+) to CD8(+), as well as the frequency of Tregs recruited by MoDC. Intratumoural injection of MoDC transfected with siCCL22 and siCCL17, significantly reduced the number of Tregs while increasing the number of infiltrating CD8(+) T cells in human tumour xenografts in athymic nude mice. This study demonstrates that chemokine expression of MoDC is complex and may change dynamically. Using siRNA to selectively knock down chemokines which are highly chemoattractive to Tregs may consequentially alter the lymphocyte populations recruited into the tumour microenvironment, therefore has the potency to provide insight into cellular interactions in cancer immunology. This may lead to a new strategy for DC vaccine development to improve cancer immunobiotherapy.

Forsythoside A Inhibits BVDV Replication via TRAF2-Dependent CD28–4-1BB Signaling in Bovine PBMCs

Science.gov (United States)

Song, Quan-Jiang; Weng, Xiao-Gang; Cai, Dong-Jie; Zhang, Wang; Wang, Jiu-Feng

2016-01-01

Bovine viral diarrhea virus (BVDV), the causative agent of bovine viral diarrhea/mucosal disease (BVD/MD), is an important pathogen of cattle and other wild animals throughout the world. BVDV infection typically leads to an impaired immune response in cattle. In the present study, we investigated the effect of Forsythoside A (FTA) on BVDV infection of bovine peripheral blood mononuclear cells (PBMCs). We found that Forsythoside A could not only promote proliferation of PBMCs and T cells activation but also inhibit the replication of BVDV as well as apoptosis induced by BVDV. FTA treatment could counteract the BVDV-induced overproduction of IFN-γ to maintain the immune homeostasis in bovine PBMCs. At same time, FTA can enhance the secretion of IL-2. What’s more, BVDV promotes the expression of CD28, 4-1BB and TRAF-2, which can be modulated by FTA. Our data suggest that FTA protects PBMCs from BVDV infection possibly via TRAF2-dependent CD28–4-1BB signaling, which may activate PBMCs in response to BVDV infection. Therefore, this aids in the development of an effective adjuvant for vaccines against BVDV and other specific FTA-based therapies for preventing BVDV infection. PMID:27617959

Transmitted/founder and chronic subtype C HIV-1 use CD4 and CCR5 receptors with equal efficiency and are not inhibited by blocking the integrin α4β7.

Directory of Open Access Journals (Sweden)

Nicholas F Parrish

Full Text Available Sexual transmission of human immunodeficiency virus type 1 (HIV-1 most often results from productive infection by a single transmitted/founder (T/F virus, indicating a stringent mucosal bottleneck. Understanding the viral traits that overcome this bottleneck could have important implications for HIV-1 vaccine design and other prevention strategies. Most T/F viruses use CCR5 to infect target cells and some encode envelope glycoproteins (Envs that contain fewer potential N-linked glycosylation sites and shorter V1/V2 variable loops than Envs from chronic viruses. Moreover, it has been reported that the gp120 subunits of certain transmitted Envs bind to the gut-homing integrin α4β7, possibly enhancing virus entry and cell-to-cell spread. Here we sought to determine whether subtype C T/F viruses, which are responsible for the majority of new HIV-1 infections worldwide, share biological properties that increase their transmission fitness, including preferential α4β7 engagement. Using single genome amplification, we generated panels of both T/F (n = 20 and chronic (n = 20 Env constructs as well as full-length T/F (n = 6 and chronic (n = 4 infectious molecular clones (IMCs. We found that T/F and chronic control Envs were indistinguishable in the efficiency with which they used CD4 and CCR5. Both groups of Envs also exhibited the same CD4+ T cell subset tropism and showed similar sensitivity to neutralization by CD4 binding site (CD4bs antibodies. Finally, saturating concentrations of anti-α4β7 antibodies failed to inhibit infection and replication of T/F as well as chronic control viruses, although the growth of the tissue culture-adapted strain SF162 was modestly impaired. These results indicate that the population bottleneck associated with mucosal HIV-1 acquisition is not due to the selection of T/F viruses that use α4β7, CD4 or CCR5 more efficiently.

CD4+CD25hiFOXP3+ cells in cord blood of neonates born from filaria infected mother are negatively associated with CD4+Tbet+ and CD4+RORγt+ T cells.

Science.gov (United States)

Ateba-Ngoa, Ulysse; Mombo-Ngoma, Ghyslain; Zettlmeissl, Eva; van der Vlugt, Luciën E P M; de Jong, Sanne E; de Jong, Sanne; Matsiegui, Pierre-Blaise; Ramharter, Michael; Kremsner, Peter G; Yazdanbakhsh, Maria; Adegnika, Ayola Akim

2014-01-01

Children who have been exposed in utero to maternal filarial infection are immunologically less responsive to filarial antigens, have less pathology, and are more susceptible to acquire infection than offspring of uninfected mothers. Moreover children from filaria infected mothers have been shown to be less responsive to vaccination as a consequence of an impairment of their immune response. However, it is not well known how in utero exposure to parasite antigens affects cellular immune responses. Here, 30 pregnant women were examined for the presence of microfilaria of Loa loa and Mansonella perstans in peripheral blood. At delivery, cord blood mononuclear cells (CBMC) were obtained and the CD4+T cells were phenotyped by expression of the transcription factors Tbet, RORγt, and FOXP3. No significant difference was observed between newborns from infected versus uninfected mothers in the frequencies of total CD4+T cells and CD4+T cells subsets including CD4+Tbet+, CD4+RORγt+ T and CD4+CD25hiFOXP3+ T cells. However, there was a negative association between CD4+CD25hiFOXP3+T cells and CD4+Tbet+ as well as CD4+RORγt+ T cells in the infected group only (B = -0.242, P = 0.002; B = -0.178, P = 0.013 respectively). Our results suggest that filarial infection during pregnancy leads to an expansion of functionally active regulatory T cells that keep TH1 and TH17 in check.

A general approach for controlling transcription and probing epigenetic mechanisms: application to the CD4 locus.

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Wan, Mimi; Kaundal, Ravinder; Huang, Haichang; Zhao, Jiugang; Yang, Xiaojun; Chaiyachati, Barbara H; Li, Sicong; Chi, Tian

2013-01-15

Synthetic regulatory proteins such as tetracycline (tet)-controlled transcription factors are potentially useful for repression as well as ectopic activation of endogenous genes and also for probing their regulatory mechanisms, which would offer a versatile genetic tool advantageous over conventional gene targeting methods. In this study, we provide evidence supporting this concept using Cd4 as a model. CD4 is expressed in double-positive and CD4 cells but irreversibly silenced in CD8 cells. The silencing is mediated by heterochromatin established during CD8 lineage development via transient action of the Cd4 silencer; once established, the heterochromatin becomes self-perpetuating independently of the Cd4 silencer. Using a tet-sensitive Cd4 allele harboring a removable Cd4 silencer, we found that a tet-controlled repressor recapitulated the phenotype of Cd4-deficient mice, inhibited Cd4 expression in a reversible and dose-dependent manner, and could surprisingly replace the Cd4 silencer to induce irreversible Cd4 silencing in CD8 cells, thus suggesting the Cd4 silencer is not the (only) determinant of heterochromatin formation. In contrast, a tet-controlled activator reversibly disrupted Cd4 silencing in CD8 cells. The Cd4 silencer impeded this disruption but was not essential for its reversal, which revealed a continuous role of the silencer in mature CD8 cells while exposing a remarkable intrinsic self-regenerative ability of heterochromatin after forced disruption. These data demonstrate an effective approach for gene manipulation and provide insights into the epigenetic Cd4 regulatory mechanisms that are otherwise difficult to obtain.

A Sensitive Method for Detecting Peptide-specific CD4+ T Cell Responses in Peripheral Blood from Patients with Myasthenia Gravis

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Sharma, Sapna; Malmeström, Clas; Lindberg, Christopher; Meisel, Sarah; Schön, Karin; Verolin, Martina; Lycke, Nils Yngve

2017-01-01

Myasthenia gravis (MG) is an autoimmune neurological disorder typified by skeletal muscle fatigue and most often production of autoantibodies against the nicotinic acetylcholine receptor (AChR). The present study was undertaken to assess the extent of AChR-peptide recognition in MG patients using co-culturing (DC:TC) of autologous monocyte-derived dendritic cells (moDCs) and highly enriched CD4+ T cells from the blood as compared to the traditional whole peripheral blood mononuclear cell (PBMC) cultures. We found that the DC:TC cultures were highly superior to the PBMC cultures for detection of reactivity toward HLA-DQ/DR-restricted AChR-peptides. In fact, whereas DC:TC cultures identified recognition in all MG patients the PBMC cultures failed to detect responsiveness in around 40% of the patients. Furthermore, reactivity to multiple peptides was evident in DC:TC cultures, while PBMC cultures mostly exhibited reactivity to a single peptide. No healthy control (HC) CD4+ T cells responded to the peptides in either culture system. Interestingly, whereas spontaneous production of IFNγ and IL-17 was observed in the DC:TC cultures from MG patients, recall responses to peptides enhanced IL-10 production in 9/13 MG patients, while little increase in IFNγ and IL-17 was seen. HCs did not produce cytokines to peptide stimulations. We conclude that the DC: TC culture system is significantly more sensitive and better identifies the extent of responsiveness in MG patients to AChR-peptides than traditional PBMC cultures. PMID:29114250

The interplay of CD150 and CD180 receptor pathways contribute to the pathobiology of chronic lymphocytic leukemia B cells by selective inhibition of Akt and MAPK signaling.

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Inna Gordiienko

Full Text Available Cell surface expression of CD150 and CD180 receptors in chronic lymphocytic leukemia (CLL associates with mutational IGHV status and favourable prognosis. Here we show a direct correlation between cell surface expression and colocalization of these receptors on CLL B cells. In the absence of CD150 and CD180 on the cell surface both receptors were expressed in the cytoplasm. The CD150 receptor was colocalized with markers of the endoplasmic reticulum, the Golgi apparatus and early endosomes. In contrast, CD180 was detected preferentially in early endosomes. Analysis of CD150 isoforms differential expression revealed that regardless of CD150 cell surface expression the mCD150 isoform with two ITSM signaling motifs was a predominant CD150 isoform in CLL B cells. The majority of CLL cases had significantly elevated expression level of the soluble sCD150, moreover CLL B cells secrete this isoform. CD150 or CD180 crosslinking on CLL B cells alone led to activation of Akt, mTORC1, ERK1/2, p38MAPK and JNK1/2 networks. Both CD150 and CD180 target the translation machinery through mTOR independent as well as mTOR dependent pathways. Moreover, both these receptors transmit pro-survival signals via Akt-mediated inhibition of GSK3β and FOXO1/FOXO3a. Unexpectedly, coligation CD150 and CD180 receptors on CLL B cells led to mutual inhibition of the Akt and MAPK pathways. While CD150 and CD180 coligation resulted in reduced phosphorylation of Akt, ERK1/2, c-Jun, RSK, p70S6K, S6RP, and 4E-BP; it led to complete blocking of mTOR and p38MAPK phosphorylation. At the same time coligation of CD150 and CD40 receptors did not result in Akt and MAPK inhibition. This suggests that combination of signals via CD150 and CD180 leads to blocking of pro-survival pathways that may be a restraining factor for neoplastic CLL B cells propagation in more than 50% of CLL cases where these receptors are coexpressed.

Demonstration of strong enterobacterial reactivity of CD4+CD25- T cells from conventional and germ-free mice which is counter-regulated by CD4+CD25+ T cells

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Gad, Monika; Pedersen, Anders Elm; Kristensen, Nanna N

2004-01-01

Unfractionated CD4+ T cells from the gut-associated lymphoid tissue (GALT) and peripheral lymph nodes are unresponsive when exposed to enterobacterial antigens in vitro. Under similar conditions, CD4+ T cells depleted in vivo or in vitro of CD4+CD25+ T cells proliferate extensively. The CD4+CD25- T...

Assessing Specific Oligonucleotides and Small Molecule Antibiotics for the Ability to Inhibit the CRD-BP-CD44 RNA Interaction

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Thomsen, Dana; Lee, Chow H.

2014-01-01

Studies on Coding Region Determinant-Binding Protein (CRD-BP) and its orthologs have confirmed their functional role in mRNA stability and localization. CRD-BP is present in extremely low levels in normal adult tissues, but it is over-expressed in many types of aggressive human cancers and in neonatal tissues. Although the exact role of CRD-BP in tumour progression is unclear, cumulative evidence suggests that its ability to physically associate with target mRNAs is an important criterion for its oncogenic role. CRD-BP has high affinity for the 3′UTR of the oncogenic CD44 mRNA and depletion of CRD-BP in cells led to destabilization of CD44 mRNA, decreased CD44 expression, reduced adhesion and disruption of invadopodia formation. Here, we further characterize the CRD-BP-CD44 RNA interaction and assess specific antisense oligonucleotides and small molecule antibiotics for their ability to inhibit the CRD-BP-CD44 RNA interaction. CRD-BP has a high affinity for binding to CD44 RNA nts 2862–3055 with a Kd of 645 nM. Out of ten antisense oligonucleotides spanning nts 2862–3055, only three antisense oligonucleotides (DD4, DD7 and DD10) were effective in competing with CRD-BP for binding to 32P-labeled CD44 RNA. The potency of DD4, DD7 and DD10 in inhibiting the CRD-BP-CD44 RNA interaction in vitro correlated with their ability to specifically reduce the steady-state level of CD44 mRNA in cells. The aminoglycoside antibiotics neomycin, paramomycin, kanamycin and streptomycin effectively inhibited the CRD-BP-CD44 RNA interaction in vitro. Assessing the potential inhibitory effect of aminoglycoside antibiotics including neomycin on the CRD-BP-CD44 mRNA interaction in cells proved difficult, likely due to their propensity to non-specifically bind nucleic acids. Our results have important implications for future studies in finding small molecules and nucleic acid-based inhibitors that interfere with protein-RNA interactions. PMID:24622399

Characterization of CD8+ T-Cell Responses in the Peripheral Blood and Skin Injection Sites of Melanoma Patients Treated with mRNA Electroporated Autologous Dendritic Cells (TriMixDC-MEL

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Daphné Benteyn

2013-01-01

Full Text Available Treatment of melanoma patients with mRNA electroporated dendritic cells (TriMixDC-MEL stimulates T-cell responses against the presented tumor-associated antigens (TAAs. In the current clinical trials, melanoma patients with systemic metastases are treated, requiring priming and/or expansion of preexisting TAA-specific T cells that are able to migrate to both the skin and internal organs. We monitored the presence of TAA-specific CD8+ T cells infiltrating the skin at sites of intradermal TriMixDC-MEL injection (SKILs and within the circulation of melanoma patients treated in two clinical trials. In 10 out of fourteen (71% patients screened, CD8+ T cells recognizing any of the four TAA presented by TriMixDC-MEL cellular vaccine were found in both compartments. In total, 30 TAA-specific T-cell responses were detected among the SKILs and 29 among peripheral blood T cells, of which 24 in common. A detailed characterization of the antigen specificity of CD8+ T-cell populations in four patients indicates that the majority of the epitopes detected were only recognized by CD8+ T cells derived from either skin biopsies or peripheral blood, indicating that some compartmentalization occurs after TriMix-DC therapy. To conclude, functional TAA-specific CD8+ T cells distribute both to the skin and peripheral blood of patients after TriMixDC-MEL therapy.

Characterization of CD8+ T-cell responses in the peripheral blood and skin injection sites of melanoma patients treated with mRNA electroporated autologous dendritic cells (TriMixDC-MEL).

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Benteyn, Daphné; Van Nuffel, An M T; Wilgenhof, Sofie; Corthals, Jurgen; Heirman, Carlo; Neyns, Bart; Thielemans, Kris; Bonehill, Aude

2013-01-01

Treatment of melanoma patients with mRNA electroporated dendritic cells (TriMixDC-MEL) stimulates T-cell responses against the presented tumor-associated antigens (TAAs). In the current clinical trials, melanoma patients with systemic metastases are treated, requiring priming and/or expansion of preexisting TAA-specific T cells that are able to migrate to both the skin and internal organs. We monitored the presence of TAA-specific CD8(+) T cells infiltrating the skin at sites of intradermal TriMixDC-MEL injection (SKILs) and within the circulation of melanoma patients treated in two clinical trials. In 10 out of fourteen (71%) patients screened, CD8(+) T cells recognizing any of the four TAA presented by TriMixDC-MEL cellular vaccine were found in both compartments. In total, 30 TAA-specific T-cell responses were detected among the SKILs and 29 among peripheral blood T cells, of which 24 in common. A detailed characterization of the antigen specificity of CD8(+) T-cell populations in four patients indicates that the majority of the epitopes detected were only recognized by CD8(+) T cells derived from either skin biopsies or peripheral blood, indicating that some compartmentalization occurs after TriMix-DC therapy. To conclude, functional TAA-specific CD8(+) T cells distribute both to the skin and peripheral blood of patients after TriMixDC-MEL therapy.

Functional and clinical relevance of VLA-4 (CD49d/CD29) in ibrutinib-treated chronic lymphocytic leukemia

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Tissino, Erika; Benedetti, Dania; Herman, Sarah E.M.; ten Hacken, Elisa; Rossi, Francesca Maria; Dal Bo, Michele; Bulian, Pietro; Bomben, Riccardo; Bayer, Elisabeth; Härzschel, Andrea; Gutjahr, Julia Christine; Postorino, Massimiliano; Santinelli, Enrico; Zaja, Francesco; Pozzato, Gabriele; Chigaev, Alexandre; Sklar, Larry A.; Burger, Jan A.; Ferrajoli, Alessandra; Shanafelt, Tait D.; Wiestner, Adrian; Del Poeta, Giovanni; Hartmann, Tanja Nicole

2018-01-01

The Bruton’s tyrosine kinase (BTK) inhibitor ibrutinib, which antagonizes B cell receptor (BCR) signals, demonstrates remarkable clinical activity in chronic lymphocytic leukemia (CLL). The lymphocytosis experienced by most patients under ibrutinib has previously been attributed to inhibition of BTK-dependent integrin and chemokine cues operating to retain the tumor cells in nodal compartments. Here, we show that the VLA-4 integrin, as expressed by CD49d-positive CLL, can be inside-out activated upon BCR triggering, thus reinforcing the adhesive capacities of CLL cells. In vitro and in vivo ibrutinib treatment, although reducing the constitutive VLA-4 activation and cell adhesion, can be overcome by exogenous BCR triggering in a BTK-independent manner involving PI3K. Clinically, in three independent ibrutinib-treated CLL cohorts, CD49d expression identifies cases with reduced lymphocytosis and inferior nodal response and behaves as independent predictor of shorter progression-free survival, suggesting the retention of CD49d-expressing CLL cells in tissue sites via activated VLA-4. Evaluation of CD49d expression should be incorporated in the characterization of CLL undergoing therapy with BCR inhibitors. PMID:29301866

Glutamic acid decarboxylase-derived epitopes with specific domains expand CD4(+CD25(+ regulatory T cells.

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Guojiang Chen

Full Text Available BACKGROUND: CD4(+CD25(+ regulatory T cell (Treg-based immunotherapy is considered a promising regimen for controlling the progression of autoimmune diabetes. In this study, we tested the hypothesis that the therapeutic effects of Tregs in response to the antigenic epitope stimulation depend on the structural properties of the epitopes used. METHODOLOGY/PRINCIPAL FINDINGS: Splenic lymphocytes from nonobese diabetic (NOD mice were stimulated with different glutamic acid decarboxylase (GAD-derived epitopes for 7-10 days and the frequency and function of Tregs was analyzed. We found that, although all expanded Tregs showed suppressive functions in vitro, only p524 (GAD524-538-expanded CD4(+CD25(+ T cells inhibited diabetes development in the co-transfer models, while p509 (GAD509-528- or p530 (GAD530-543-expanded CD4(+CD25(+ T cells had no such effects. Using computer-guided molecular modeling and docking methods, the differences in structural characteristics of these epitopes and the interaction mode (including binding energy and identified domains in the epitopes between the above-mentioned epitopes and MHC class II I-A(g7 were analyzed. The theoretical results showed that the epitope p524, which induced protective Tregs, possessed negative surface-electrostatic potential and bound two chains of MHC class II I-A(g7, while the epitopes p509 and p530 which had no such ability exhibited positive surface-electrostatic potential and bound one chain of I-A(g7. Furthermore, p524 bound to I-A(g7 more stably than p509 and p530. Of importance, we hypothesized and subsequently confirmed experimentally that the epitope (GAD570-585, p570, which displayed similar characteristics to p524, was a protective epitope by showing that p570-expanded CD4(+CD25(+ T cells suppressed the onset of diabetes in NOD mice. CONCLUSIONS/SIGNIFICANCE: These data suggest that molecular modeling-based structural analysis of epitopes may be an instrumental tool for prediction of

Increased Aqueous Humor CD4+/CD8+ Lymphocyte Ratio in Sarcoid Uveitis.

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Dave, Namita; Chevour, Priyanka; Mahendradas, Padmamalini; Venkatesh, Anitha; Kawali, Ankush; Shetty, Rohit; Ghosh, Arkasubhra; Sethu, Swaminathan

2018-02-08

To determine aqueous humor CD4+/CD8+ T-lymphocyte ratio changes in sarcoid and non-sarcoid uveitis with anterior chamber involvement. The case-control study includes 61 patients with either anterior uveitis, intermediate uveitis with anterior spill, or panuveitis. A total of 21 of them were categorized as sarcoid uveitis and 40 as non-sarcoid uveitis according to diagnostic criteria. CD4+/CD8+ ratio in the aqueous humor was determined using flow cytometry. Significantly higher CD4+/CD8+ ratio in the aqueous humor was observed in patients with sarcoid uveitis (6.3 ± 1.4; mean ± SEM) compared to non-sarcoid uveitis (1.6 ± 0.1; mean ± SEM). Whole blood CD4+/CD8+ ratio was not elevated in subjects with sarcoid and non-sarcoid uveitis. Aqueous humor CD4+/CD8+ ratio >3.5 was observed to be associated with sarcoid uveitis (OR 38, 95% CI 7.0-205.2). Increased aqueous humor CD4+/CD8+ ratio in sarcoid uveitis. Immunophenotyping of localized lymphocytosis in aqueous humor could be utilized as an additional confirmatory marker for ocular sarcoidosis.

CD40L induces functional tunneling nanotube networks exclusively in dendritic cells programmed by mediators of type 1 immunity.

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Zaccard, Colleen R; Watkins, Simon C; Kalinski, Pawel; Fecek, Ronald J; Yates, Aarika L; Salter, Russell D; Ayyavoo, Velpandi; Rinaldo, Charles R; Mailliard, Robbie B

2015-02-01

The ability of dendritic cells (DC) to mediate CD4(+) T cell help for cellular immunity is guided by instructive signals received during DC maturation, as well as the resulting pattern of DC responsiveness to the Th signal, CD40L. Furthermore, the professional transfer of antigenic information from migratory DC to lymph node-residing DC is critical for the effective induction of cellular immune responses. In this study we report that, in addition to their enhanced IL-12p70 producing capacity, human DC matured in the presence of inflammatory mediators of type 1 immunity are uniquely programmed to form networks of tunneling nanotube-like structures in response to CD40L-expressing Th cells or rCD40L. This immunologic process of DC reticulation facilitates intercellular trafficking of endosome-associated vesicles and Ag, but also pathogens such HIV-1, and is regulated by the opposing roles of IFN-γ and IL-4. The initiation of DC reticulation represents a novel helper function of CD40L and a superior mechanism of intercellular communication possessed by type 1 polarized DC, as well as a target for exploitation by pathogens to enhance direct cell-to-cell spread. Copyright © 2015 by The American Association of Immunologists, Inc.

Effect of DC-CIK treatment on tumor markers and T cell subsets in patients with advanced ovarian cancer

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Jie-Qun Guo

2016-10-01

Full Text Available Objective: To investigate the effects of dendritic cells (DC and cytokine induced killer cells (CIK on tumor markers and T cell subsets in peripheral blood of patients with advanced ovarian cancer. Methods: A total of 100 cases of patients with advanced ovarian cancer who were proved by operation and pathology in the department of gynecologic oncology in our hospital were selected from April 2013 to April 20l6, and randomly divided into experimental group and control group, the control group was treated with TC (Taxinol+Cisplat chemotherapy alone, the experimental group was treated with DC-CIK combined with chemotherapy. Before and after treatment, the changes of CD3+, CD4+, CD8+, CD4+/CD8+, CD4+/CD25+, NK cells in peripheral blood and serum tumor markers (CA125, CA19-9, HE4 were detected. Results: Before treatment, the phenotypes of T cell subsets in the two groups were not significantly different; in the experimental group after treatment, the levels of CD3+, CD4+, CD4+/CD8+, and NK cells were increased,while the levels of CD4+/CD25+ and CD8+ were decreased, compared with before treatment, the differences were statistically significant; the phenotype changes of T cells were not statistically significant before and after treatment in the control group; after treatment, there were significant differences in the levels of CD4+, CD8+, CD4+/CD8+, CD4+/CD25+ and NK cells between the two groups. Before treatment, there were no significant differences in HE4 value, CA125 value and CA19-9 value between the two groups; after treatment, the tumor markers in the two groups were all decreased, and the difference was significant as compared with those before treatment; after treatment, the CA125 value, CA19-9 value and HE4 value were (73.68±79.46 U/mL, (54.32±32.85 U/mL and (69.57±39.85 pmol/L respectively, the values of three tumor markers were compared with the control group, with a statistical difference. Conclusion: DC-CIK treatment can improve the

A DNA vaccine encoding multiple HIV CD4 epitopes elicits vigorous polyfunctional, long-lived CD4+ and CD8+ T cell responses.

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Daniela Santoro Rosa

Full Text Available T-cell based vaccines against HIV have the goal of limiting both transmission and disease progression by inducing broad and functionally relevant T cell responses. Moreover, polyfunctional and long-lived specific memory T cells have been associated to vaccine-induced protection. CD4(+ T cells are important for the generation and maintenance of functional CD8(+ cytotoxic T cells. We have recently developed a DNA vaccine encoding 18 conserved multiple HLA-DR-binding HIV-1 CD4 epitopes (HIVBr18, capable of eliciting broad CD4(+ T cell responses in multiple HLA class II transgenic mice. Here, we evaluated the breadth and functional profile of HIVBr18-induced immune responses in BALB/c mice. Immunized mice displayed high-magnitude, broad CD4(+/CD8(+ T cell responses, and 8/18 vaccine-encoded peptides were recognized. In addition, HIVBr18 immunization was able to induce polyfunctional CD4(+ and CD8(+ T cells that proliferate and produce any two cytokines (IFNγ/TNFα, IFNγ/IL-2 or TNFα/IL-2 simultaneously in response to HIV-1 peptides. For CD4(+ T cells exclusively, we also detected cells that proliferate and produce all three tested cytokines simultaneously (IFNγ/TNFα/IL-2. The vaccine also generated long-lived central and effector memory CD4(+ T cells, a desirable feature for T-cell based vaccines. By virtue of inducing broad, polyfunctional and long-lived T cell responses against conserved CD4(+ T cell epitopes, combined administration of this vaccine concept may provide sustained help for CD8(+ T cells and antibody responses- elicited by other HIV immunogens.

MicroRNA-4443 Causes CD4+ T Cells Dysfunction by Targeting TNFR-Associated Factor 4 in Graves’ Disease

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Yicheng Qi

2017-11-01

Full Text Available ContextAberrant CD4+ T cell function plays a critical role in the process of Graves’ disease (GD. MicroRNAs (miRNAs are important regulators of T cell activation, proliferation, and cytokine production. However, the contribution of miRNAs to CD4+ T cell dysfunction in GD remains unclear.ObjectiveTo investigate how certain miRNA causes aberrant CD4+ T cell function in GD patients.MethodsWe compared the expression pattern of miRNAs in CD4+ T cells from untreated GD (UGD patients with those from healthy controls. The most significantly dysregulated miRNAs were selected and their correlations with clinical parameters were analyzed. The effect of miR-4443 on CD4+ T cells cytokines production and proliferation was assessed. The potential gene target was identified and validated.ResultsGD patients had unique pattern of miRNA expression profile in CD4+ T cells comparing to healthy subjects. miR-10a, miR-125b, and miR-4443 were the three most significantly dysregulated miRNAs. The elevated miR-4443 levels were strongly correlated with clinical parameters in an independent dataset of UGD patients (N = 40, while miR-4443 was normally expressed in GD patients with euthyroidism and negative TRAb level. We found that miR-4443 directly inhibited TNFR-associated factor (TRAF 4 expression to increase CD4+ T cells cytokines secretion as well as proliferation through the NF-κB pathway. Furthermore, the TRAF4 levels in GD patients were inversely correlated with miR-4443, and knocking down TRAF4 had a similar effect with miR-4443 overexpression.ConclusionThe increased expression of miR-4443 induced CD4+ T cells dysfunction by targeting TRAF4, which may cause GD.

Cellular reactions of CD3+ CD4+ CD45RO+ T-lymphocytes on dexamethason in in normal patients and in patients with with rheumatoid arthritis in vitro

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L. S. Litvinova

2017-01-01

Full Text Available The aim of the study was to analyze the influence of glucocorticoid (GC dexamethasone (Dex on changes in CD4+ T-cells expressing the surface molecule of activation (CD25, CD71, HLA-DR and CD95 and their ability to produce proinflammatory mediators in cultures of TCR-stimulated CD3+CD45RO+ T-lymphocytes obtained from healthy donors and patients with rheumatoid arthritis in vitro.Materials and methods. The study included 50 patients and 20 healthy donors. T-cell cultures (CD3+ CD45RO+ were obtained from mononuclear leukocytes of immunomagnetic separation (MACS® technology. As an activator of T-lymphocytes, antibiotic particles with biotinylated antibodies against CD2+, CD3+, CD28+, which simulate the process of costimulation of T cells by antigen-presenting cells, were used. The following concentrations of dexamethasone (2, 8, 16, 32, 64 mg were used in the experiment. The change in the immunophenotype of T-lymphocytes was analyzed by flow cytofluoometry. The secretion of CD3+CD45RO+ T-cells of proinflammatory cytokines IL-2, IFNγ, TNFα, IL-17 and IL-21 was evaluated by enzyme-linked immunosorbent assay.Results. The general suppressor effect of Dex on CD3+CD45RO+ T-cell cultures mediated by a decrease in the number of CD4 + T cells expressing activation molecules (CD25 and proliferation (CD71, as well as inhibition of the production of inflammatory mediators: IFNγ, IL-2 and TNFα. It is shown that against the background of TCR activation Dex increases the number of CD4+CD95+HLA-DR+ cells in CD3+CD45RO+ cultures obtained from RA patients and does not change their content in the control. The correlations between the number of proinflammatory factors (IL-17, IL-21 and TNFα in CD4+CD45RO+CD95+HLA-DR+ T cells in supernatants of cell cultures in RA patients indicate the presence of a pro-inflammatory potential of this population of T cells. We assume that the resistance of CD4+CD45RO+CD95+HLA-DR+ T cells in RA patients to the suppressor effect of

CD4+, CD8+, CD3+ cell counts and CD4+/CD8+ ratio among patients with mycobacterial diseases (leprosy, tuberculosis), HIV infections, and normal healthy adults: a comparative analysis of studies in different regions of India.

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Hussain, Tahziba; Kulshreshtha, K K; Yadav, V S; Katoch, Kiran

2015-01-01

In this study, we estimated the CD4+, CD8+, CD3+ cell counts and the CD4/CD8 ratio among normal healthy controls (adults and children), leprosy patients (without any complications and during reactional states), TB patients (with and without HIV), and HIV-positive patients (early infection and full-blown AIDS) and correlated the changes with disease progression. In our study, it was observed that among adults, CD4+ cell counts ranged from 518-1098, CD8+ from 312-952, whereas CD4/CD8 ratio from 0.75-2.30. Among children, both CD4+ and CD8+ cells were more and the CD4/CD8 ratio varied from 0.91-3.17. With regard to leprosy patients, we observed that CD4+ and CD8+ cell counts were lower among PB (pauci-bacillary) and MB (multi-bacillary) patients. CD4/CD8 ratio was 0.99 ± 0.28 among PB patients while the ratio was lower, 0.78 ± 0.20, among MB patients. CD4+ cell counts were raised during RR (reversal reactions) and ENL (erythema nodosum leprosum) among the PB and MB patients whereas the CD8+ cell counts were lower among PB and MB patients. CD4/CD8 ratio doubled during reactional episodes of RR and ENL. Among the HIV-negative tuberculosis (TB) patients, both the CD4+ and CD8+ cell counts were found to be less and the CD4/CD8 ratio varied between 0.53-1.75. Among the HIV-positive TB patients and HIV-positive patients, both the CD4+ and CD8+ cells were very less and ratio drops significantly. In the initial stages of infection, as CD4+ counts drop, an increase in the CD8+ cell counts was observed and the ratio declines. In full-blown cases, CD4+ cell counts were very low, 3-4 to 54 cells, CD8+ cells from 12-211 and the ratio drops too low. This study is the first of its kind in this region of the country and assumes importance since no other study has reported the values of CD4+ and CD8+ T-lymphocyte counts among patients with mycobacterial diseases (leprosy and TB), HIV infections along with normal healthy individuals of the region, and correlation with clinical

Capacity of lung stroma to educate dendritic cells inhibiting mycobacteria-specific T-cell response depends upon genetic susceptibility to tuberculosis.

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Kapina, Marina A; Rubakova, Elvira I; Majorov, Konstantin B; Logunova, Nadezhda N; Apt, Alexander S

2013-01-01

The balance between activation and inhibition of local immune responses in affected tissues during prolonged chronic infections is important for host protection. There is ample evidence that regulatory, tolerogenic dendritic cells (DC) are developed and present in tissues and inhibit overwhelming inflammatory reactions. Also, it was firmly established that stromal microenvironment of many organs is able to induce development of immature regulatory DC (DCreg), an essential element of a general immune regulatory network. However, direct experimental data demonstrating inhibition of immune responses by stroma-instructed immature DCreg in infectious models are scarce, and virtually nothing is known about functioning of this axis of immunity during tuberculosis (TB) infection. In this study, we demonstrate that lung stromal cells are capable of supporting the development in culture of immature CD11b(+)CD11c(low)CD103(-) DCreg from lineage-negative (lin(-)) bone marrow precursors. DCreg developed on lung stroma isolated from mice of genetically TB-hyper-susceptible I/St and relatively resistant B6 inbred strains inhibited proliferative response of mycobacteria-specific CD4(+) T-cell lines a dose-dependent manner. Importantly, the inhibitory activity of B6 DCreg was substantially higher than that of I/St Dcreg. Moreover, when the donors of stromal cells were chronically infected with virulent mycobacteria, the capacity to instruct inhibitory DCreg was retained in B6, but further diminished in I/St stromal cells. DCreg-provided suppression was mediated by a few soluble mediators, including PGE2, NO and IL-10. The content of CD4(+)Foxp3(+) Treg cells in the mediastinal, lung-draining lymph nodes at the advanced stages of chronic infection did not change in I/St, but increased 2-fold in B6 mice, and lung pathology was much more pronounced in the former mice. Taken together, these data provide genetic evidence that the capacity to maintain populations of regulatory cells

Capacity of lung stroma to educate dendritic cells inhibiting mycobacteria-specific T-cell response depends upon genetic susceptibility to tuberculosis.

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Marina A Kapina

Full Text Available The balance between activation and inhibition of local immune responses in affected tissues during prolonged chronic infections is important for host protection. There is ample evidence that regulatory, tolerogenic dendritic cells (DC are developed and present in tissues and inhibit overwhelming inflammatory reactions. Also, it was firmly established that stromal microenvironment of many organs is able to induce development of immature regulatory DC (DCreg, an essential element of a general immune regulatory network. However, direct experimental data demonstrating inhibition of immune responses by stroma-instructed immature DCreg in infectious models are scarce, and virtually nothing is known about functioning of this axis of immunity during tuberculosis (TB infection. In this study, we demonstrate that lung stromal cells are capable of supporting the development in culture of immature CD11b(+CD11c(lowCD103(- DCreg from lineage-negative (lin(- bone marrow precursors. DCreg developed on lung stroma isolated from mice of genetically TB-hyper-susceptible I/St and relatively resistant B6 inbred strains inhibited proliferative response of mycobacteria-specific CD4(+ T-cell lines a dose-dependent manner. Importantly, the inhibitory activity of B6 DCreg was substantially higher than that of I/St Dcreg. Moreover, when the donors of stromal cells were chronically infected with virulent mycobacteria, the capacity to instruct inhibitory DCreg was retained in B6, but further diminished in I/St stromal cells. DCreg-provided suppression was mediated by a few soluble mediators, including PGE2, NO and IL-10. The content of CD4(+Foxp3(+ Treg cells in the mediastinal, lung-draining lymph nodes at the advanced stages of chronic infection did not change in I/St, but increased 2-fold in B6 mice, and lung pathology was much more pronounced in the former mice. Taken together, these data provide genetic evidence that the capacity to maintain populations of regulatory

Multidimensional Clusters of CD4+T Cell Dysfunction Are Primarily Associated with the CD4/CD8 Ratio in Chronic HIV Infection

DEFF Research Database (Denmark)

Frederiksen, Juliet Wairimu; Buggert, Marcus; Noyan, Kajsa

2015-01-01

was compared to a multidimensional clustering tool, FLOw Clustering with K (FLOCK) in two cohorts of 47 untreated HIV-infected individuals and 21 age and sex matched healthy controls. In order to reduce the subjectivity of FLOCK, we developed an "artificial reference", using 2% of all CD4+ gated T cells from...... each of the HIV-infected individuals. Principle component analyses demonstrated that using an artificial reference lead to a better separation of the HIV-infected individuals from the healthy controls as compared to using a single HIV-infected subject as a reference or analyzing data manually. Multiple...... correlation analyses between laboratory parameters and pathological CD4+ clusters revealed that the CD4/CD8 ratio was the preeminent surrogate marker of CD4+ T cells dysfunction using all three methods. Increased frequencies of an early-differentiated CD4+ T cell cluster with high CD38, HLA-DR and PD-1...

Regulation of CD95 expression and CD95-mediated cell death by interferon-gamma in acute lymphoblastic leukemia with chromosomal translocation t(4;11).

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Dörrie, J; Schuh, W; Keil, A; Bongards, E; Greil, J; Fey, G H; Zunino, S J

1999-10-01

The regulatory effects of IFNgamma on CD95 expression and CD95-mediated cell death were investigated in three high-risk pro-B acute lymphoblastic leukemia (ALL) lines that carry the chromosomal translocation t(4;11)(q21;q23). These leukemias are characteristically refractory to conventional chemotherapeutic treatments operating through the induction of apoptosis. However, the mechanisms leading to increased cell survival and resistance to cell death in these leukemias are largely unknown. Interferon-gamma (IFNgamma), a potent inhibitor of hematopoiesis, acts in part by upregulating CD95 and sensitizing cells to CD95-induced apoptosis. The t(4;11) lines SEM, RS4;11, and MV4;11 expressed low levels of CD95, but were completely resistant to CD95-mediated death. Addition of IFNgamma markedly upregulated CD95 expression in SEM (8-9-fold), RS4;11 (2-3-fold), and MV4;11 (2-3-fold) lines. However, after treatment with IFNgamma, only an 11% increase in sensitivity to CD95-mediated cell death was observed in SEM cells, whereas RS4;11 and MV4;11 cells remained resistant. Cycloheximide, but not actinomycin D or brefeldin A, increased CD95-specific cell death only in IFNgamma-treated RS4;11 cells by approximately 12%. Abundant levels of Bcl-2 and Bcl-XL, known to inhibit CD95-signaling in some cells, were present suggesting a possible role for both molecules in the resistance to CD95-mediated cell death. Resistance of the leukemic blasts to CD95-mediated cell death and the failure of IFNgamma to substantially sensitize the CD95-signaling pathway may contribute to the highly malignant phenotype of pro-B ALL with translocation t(4;11).

Activation of human CD141+ and CD1c+ dendritic cells in vivo with combined TLR3 and TLR7/8 ligation.

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Pearson, Frances E; Chang, Karshing; Minoda, Yoshihito; Rojas, Ingrid M Leal; Haigh, Oscar L; Daraj, Ghazal; Tullett, Kirsteen M; Radford, Kristen J

2018-04-01

Mice reconstituted with human hematopoietic stem cells are valuable models to study aspects of the human immune system in vivo. We describe a humanized mouse model (hu mice) in which fully functional human CD141 + and CD1c + myeloid and CD123 + plasmacytoid dendritic cells (DC) develop from human cord blood CD34 + cells in immunodeficient mice. CD141 + DC are the human equivalents of murine CD8 + /CD103 + DC which are essential for the induction of tumor-inhibitory cytotoxic T lymphocyte responses, making them attractive targets to exploit for the development of new cancer immunotherapies. We used CD34 + -engrafted NSG-A2 mice to investigate activation of DC subsets by synthetic dsRNA or ssRNA analogs polyinosinic-polycytidylic acid/poly I:C and Resiquimod/R848, agonists for TLR3 and TLR8, respectively, both of which are expressed by CD141 + DC. Injection of hu mice with these agonists resulted in upregulation of costimulatory molecules CD80, CD83 and CD86 by CD141 + and CD1c + DC alike, and their combination further enhanced expression of these molecules by both subsets. When combined, poly I:C and R848 enhanced serum levels of key cytokines associated with cross-presentation and the induction of cytotoxic T lymphocyte responses including IFN-α, IFN-β, IL-12 and CXCL10. These data advocate a combination of poly I:C and R848 TLR agonists as means of activating human DC for immunotherapy. © 2018 Australasian Society for Immunology Inc.

Identification of NY-BR-1-specific CD4(+) T cell epitopes using HLA-transgenic mice.

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Gardyan, Adriane; Osen, Wolfram; Zörnig, Inka; Podola, Lilli; Agarwal, Maria; Aulmann, Sebastian; Ruggiero, Eliana; Schmidt, Manfred; Halama, Niels; Leuchs, Barbara; von Kalle, Christof; Beckhove, Philipp; Schneeweiss, Andreas; Jäger, Dirk; Eichmüller, Stefan B

2015-06-01

Breast cancer represents the second most common cancer type worldwide and has remained the leading cause of cancer-related deaths among women. The differentiation antigen NY-BR-1 appears overexpressed in invasive mammary carcinomas compared to healthy breast tissue, thus representing a promising target antigen for T cell based tumor immunotherapy approaches. Since efficient immune attack of tumors depends on the activity of tumor antigen-specific CD4(+) effector T cells, NY-BR-1 was screened for the presence of HLA-restricted CD4(+) T cell epitopes that could be included in immunological treatment approaches. Upon NY-BR-1-specific DNA immunization of HLA-transgenic mice and functional ex vivo analysis, a panel of NY-BR-1-derived library peptides was determined that specifically stimulated IFNγ secretion among splenocytes of immunized mice. Following in silico analyses, four candidate epitopes were determined which were successfully used for peptide immunization to establish NY-BR-1-specific, HLA-DRB1*0301- or HLA-DRB1*0401-restricted CD4(+) T cell lines from splenocytes of peptide immunized HLA-transgenic mice. Notably, all four CD4(+) T cell lines recognized human HLA-DR-matched dendritic cells (DC) pulsed with lysates of NY-BR-1 expressing human tumor cells, demonstrating natural processing of these epitopes also within the human system. Finally, CD4(+) T cells specific for all four CD4(+) T cell epitopes were detectable among PBMC of breast cancer patients, showing that CD4(+) T cell responses against the new epitopes are not deleted nor inactivated by self-tolerance mechanisms. Our results present the first NY-BR-1-specific HLA-DRB1*0301- and HLA-DRB1*0401-restricted T cell epitopes that could be exploited for therapeutic intervention against breast cancer. © 2014 UICC.

Relationship of CD86 surface marker expression and cytotoxicity on dendritic cells exposed to chemical allergen

International Nuclear Information System (INIS)

Hulette, Ben C.; Ryan, Cindy A.; Gildea, Lucy A.; Gerberick, G. Frank

2005-01-01

Human peripheral blood-derived dendritic cells (DC) respond to a variety of chemical allergens by up-regulating expression of the co-stimulatory molecule CD86. It has been postulated that this measure might provide the basis for an in vitro alternative approach for the identification of skin sensitizing chemicals. We recently reported that DC, exposed in culture to the highest non-cytotoxic concentrations of various chemical allergens, displayed marginal up-regulation of membrane CD86 expression; the interpretation being that such changes were insufficiently sensitive for the purposes of hazard identification. For the work presented here, immature DC were derived from human monocytes and treated with the chemical allergens 2,4-dinitrobenzenesulfonic acid (DNBS), nickel sulfate (NiSO 4 ), p-phenylenediamine (PPD), Bandrowski's base (BB), hydroquinone (HQ) and propyl gallate (PG) for 48 h at concentrations which induced both no to slight to moderate cytotoxicity. For comparison, DC were treated with the irritants sodium dodecyl sulfate (SDS), benzoic acid (BA), and benzalkonium chloride (BZC) at concentrations resulting in comparable levels of cytotoxicity. CD86 expression, as measured by flow cytometry, was consistently up-regulated (ranging from 162 to 386% control) on DC treated with concentrations of chemical allergens that induced approximately 10-15% cytotoxicity. The irritants BA and BZC did not induce up-regulation of CD86 expression when tested at concentrations that induced similar levels of cytotoxicity. SDS, however, up-regulated CD86 expression to 125-138% of control in 2/4 preparations when tested at concentrations which induced similar toxicity. Our results confirm that chemical allergens up-regulate CD86 expression on blood-derived DC and illustrate further that up-regulation of CD86 surface marker expression is more robust when DC are treated with concentrations of chemical allergen that induce slight to moderate cytotoxicity

IL-10-produced by human transitional B-cells down-regulates CD86 expression on B-cells leading to inhibition of CD4+T-cell responses.

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Nova-Lamperti, Estefania; Fanelli, Giorgia; Becker, Pablo D; Chana, Prabhjoat; Elgueta, Raul; Dodd, Philippa C; Lord, Graham M; Lombardi, Giovanna; Hernandez-Fuentes, Maria P

2016-01-22

A novel subset of human regulatory B-cells has recently been described. They arise from within the transitional B-cell subpopulation and are characterised by the production of IL-10. They appear to be of significant importance in regulating T-cell immunity in vivo. Despite this important function, the molecular mechanisms by which they control T-cell activation are incompletely defined. Here we show that transitional B-cells produced more IL-10 and expressed higher levels of IL-10 receptor after CD40 engagement compared to other B-cell subsets. Furthermore, under this stimulatory condition, CD86 expressed by transitional B-cells was down regulated and T-cell proliferation was reduced. We provide evidence to demonstrate that the down-regulation of CD86 expression by transitional B-cells was due to the autocrine effect of IL-10, which in turn leads to decreased T-cell proliferation and TNF-α production. This analysis was further extended to peripheral B-cells in kidney transplant recipients. We observed that B-cells from patients tolerant to the graft maintained higher IL-10 production after CD40 ligation, which correlates with lower CD86 expression compared to patients with chronic rejection. Hence, the results obtained in this study shed light on a new alternative mechanism by which transitional B-cells inhibit T-cell proliferation and cytokine production.

IL-10-produced by human transitional B-cells down-regulates CD86 expression on B-cells leading to inhibition of CD4+T-cell responses

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Nova-Lamperti, Estefania; Fanelli, Giorgia; Becker, Pablo D.; Chana, Prabhjoat; Elgueta, Raul; Dodd, Philippa C.; Lord, Graham M.; Lombardi, Giovanna; Hernandez-Fuentes, Maria P.

2016-01-01

A novel subset of human regulatory B-cells has recently been described. They arise from within the transitional B-cell subpopulation and are characterised by the production of IL-10. They appear to be of significant importance in regulating T-cell immunity in vivo. Despite this important function, the molecular mechanisms by which they control T-cell activation are incompletely defined. Here we show that transitional B-cells produced more IL-10 and expressed higher levels of IL-10 receptor after CD40 engagement compared to other B-cell subsets. Furthermore, under this stimulatory condition, CD86 expressed by transitional B-cells was down regulated and T-cell proliferation was reduced. We provide evidence to demonstrate that the down-regulation of CD86 expression by transitional B-cells was due to the autocrine effect of IL-10, which in turn leads to decreased T-cell proliferation and TNF-α production. This analysis was further extended to peripheral B-cells in kidney transplant recipients. We observed that B-cells from patients tolerant to the graft maintained higher IL-10 production after CD40 ligation, which correlates with lower CD86 expression compared to patients with chronic rejection. Hence, the results obtained in this study shed light on a new alternative mechanism by which transitional B-cells inhibit T-cell proliferation and cytokine production. PMID:26795594

RB4CD12 epitope expression and heparan sulfate disaccharide composition in brain vasculature.

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Hosono-Fukao, Tomomi; Ohtake-Niimi, Shiori; Nishitsuji, Kazuchika; Hossain, Md Motarab; van Kuppevelt, Toin H; Michikawa, Makoto; Uchimura, Kenji

2011-11-01

RB4CD12 is a phage display antibody that recognizes a heparan sulfate (HS) glycosaminoglycan epitope. The epitope structure is proposed to contain a trisulfated disaccharide, [-IdoA(2-OSO(3))-GlcNSO(3) (6-OSO(3))-], which supports HS binding to various macromolecules such as growth factors and cytokines in central nervous tissues. Chemically modified heparins that lack the trisulfated disaccharides failed to inhibit the RB4CD12 recognition of HS chains. To determine the localization of the RB4CD12 anti-HS epitope in the brain, we performed an immunohistochemical analysis for cryocut sections of mouse brain. The RB4CD12 staining signals were colocalized with laminin and were detected abundantly in the vascular basement membrane. Bacterial heparinases eliminated the RB4CD12 staining signals. The RB4CD12 epitope localization was confirmed by immunoelectron microscopy. Western blotting analysis revealed that the size of a major RB4CD12-positive molecule is ∼460 kDa in a vessel-enriched fraction of the mouse brain. Disaccharide analysis with reversed-phase ion-pair HPLC showed that [-IdoA(2-OSO(3))-GlcNSO(3) (6-OSO(3))-] trisulfated disaccharide residues are present in HS purified from the vessel-enriched brain fraction. These results indicated that the RB4CD12 anti-HS epitope exists in large quantities in the brain vascular basement membrane. Copyright © 2011 Wiley-Liss, Inc.

Relative Contribution of Cellular Complement Inhibitors CD59, CD46, and CD55 to Parainfluenza Virus 5 Inhibition of Complement-Mediated Neutralization

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Yujia Li

2018-04-01

Full Text Available The complement system is a part of the innate immune system that viruses need to face during infections. Many viruses incorporate cellular regulators of complement activation (RCA to block complement pathways and our prior work has shown that Parainfluenza virus 5 (PIV5 incorporates CD55 and CD46 to delay complement-mediated neutralization. In this paper, we tested the role of a third individual RCA inhibitor CD59 in PIV5 interactions with complement pathways. Using a cell line engineered to express CD59, we show that small levels of functional CD59 are associated with progeny PIV5, which is capable of blocking assembly of the C5b-C9 membrane attack complex (MAC. PIV5 containing CD59 (PIV5-CD59 showed increased resistance to complement-mediated neutralization in vitro comparing to PIV5 lacking regulators. Infection of A549 cells with PIV5 and RSV upregulated CD59 expression. TGF-beta treatment of PIV5-infected cells also increased cell surface CD59 expression and progeny virions were more resistant to complement-mediated neutralization. A comparison of individual viruses containing only CD55, CD46, or CD59 showed a potency of inhibiting complement-mediated neutralization, which followed a pattern of CD55 > CD46 > CD59.

In ovo injection of anti-chicken CD25 monoclonal antibodies depletes CD4+CD25+ T cells in chickens.

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Shanmugasundaram, Revathi; Selvaraj, Ramesh K

2013-01-01

The CD4(+)CD25(+) cells have T regulatory cell properties in chickens. This study investigated the effect of in ovo injection of anti-chicken CD25 monoclonal antibodies (0.5 mg/egg) on CD4(+)CD25(+) cell depletion and on amounts of interleukin-2 mRNA and interferon-γ mRNA in CD4(+)CD25(-) cells posthatch. Anti-chicken CD25 or PBS (control) was injected into 16-d-old embryos. Chicks hatched from eggs injected with anti-chicken CD25 antibodies had a lower CD4(+)CD25(+) cell percentage in the blood until 25 d posthatch. The anti-chicken CD25 antibody injection nearly depleted CD4(+)CD25(+) cells in the blood until 16 d posthatch. At 30 d posthatch, the CD4(+)CD25(+) cell percentage in the anti-CD25-antibody-injected group was comparable with the percentage in the control group. At 16 d posthatch, the anti-chicken CD25 antibody injection decreased CD4(+)CD25(+) cell percentages in the thymus, spleen, and cecal tonsils. Chickens hatched from anti-CD25-antibody-injected eggs had approximately 25% of CD4(+)CD25(+) cells in the cecal tonsils and thymus compared with those in the cecal tonsils and thymus of the control group. The CD4(+)CD25(-) cells from the spleen and cecal tonsils of chicks hatched from anti-chicken-CD25-injected eggs had higher amounts of interferon-γ and interleukin-2 mRNA than CD4(+)CD25(-) cells from the control group. It could be concluded that injecting anti-chicken CD25 antibodies in ovo at 16 d of incubation nearly depleted the CD4(+)CD25(+) cells until 25 d posthatch.

CD147-mediated chemotaxis of CD4+CD161+ T cells may contribute to local inflammation in rheumatoid arthritis.

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Lv, Minghua; Miao, Jinlin; Zhao, Peng; Luo, Xing; Han, Qing; Wu, Zhenbiao; Zhang, Kui; Zhu, Ping

2018-01-01

CD161 is used as a surrogate marker for Th17 cells, which are implicated in the pathogenesis of rheumatoid arthritis (RA). In this study, we evaluated the percentage, clinical significance, and CD98 and CD147 expression of CD4 + CD161 + T cells. The potential role of CD147 and CD98 in cyclophilin A-induced chemotaxis of CD4 + CD161 + T cells was analyzed. Thirty-seven RA patients, 15 paired synovial fluid (SF) of RA, and 22 healthy controls were recruited. The cell populations and surface expression of CD98 and CD147 were analyzed by flow cytometry. Spearman's rank correlation coefficient and multiple linear regression were applied to calculate the correlations. Chemotaxis assay was used to investigate CD4 + CD161 + T cell migration. We found that the percentage of CD4 + CD161 + T cells and their expression of CD147 and CD98 in SF were higher than in the peripheral blood of RA patients. Percentage of SF CD4 + CD161 + T cells was positively correlated with 28-Joint Disease Activity Score (DAS28). CD147 monoclonal antibody (HAb18) attenuated the chemotactic ability of CD4 + CD161 + T cells. An increased CD4 + CD161 + T cell percentage and expression of CD147 and CD98 were shown in RA SF. Percentage of SF CD4 + CD161 + T cells can be used as a predictive marker of disease activity in RA. CD147 block significantly decreased the chemotactic index of CD4 + CD161 + cells induced by cyclophilin A (CypA). These results imply that the accumulation of CD4 + CD161 + T cells in SF and their high expression of CD147 may be associated with CypA-mediated chemotaxis and contribute to local inflammation in RA.

B-cell inhibition by cross-linking CD79b is superior to B-cell depletion with anti-CD20 antibodies in treating murine collagen-induced arthritis

Czech Academy of Sciences Publication Activity Database

Bruhl, H.; Cihak, J.; Talke, Y.; Rodriguez-Gomez, M.; Hermann, F.; Goebel, N.; Renner, K.; Plachý, Jiří; Stangassinger, M.; Archemann, S.; Nimmerjahn, F.; Mack, M.

2015-01-01

Roč. 45, č. 3 (2015), s. 705-715 ISSN 0014-2980 Institutional support: RVO:68378050 Keywords : Arthritis * B cells * B-cell depletion * B-cell inhibition * CD79b * Humoral immune response Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.179, year: 2015

Colorectal cancer cells suppress CD4+ T cells immunity through canonical Wnt signaling.

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Sun, Xuan; Liu, Suoning; Wang, Daguang; Zhang, Yang; Li, Wei; Guo, Yuchen; Zhang, Hua; Suo, Jian

2017-02-28

Understanding how colorectal cancer escapes from immunosurveillance and immune attack is important for developing novel immunotherapies for colorectal cancer. In this study we evaluated the role of canonical Wnt signaling in the regulation of T cell function in a mouse colorectal cancer model. We found that colorectal cancer cells expressed abundant Wnt ligands, and intratumoral T cells expressed various Frizzled proteins. Meanwhile, both active β-catenin and total β-catenin were elevated in intratumoral T cells. In vitro study indicated that colorectal cancer cells suppressed IFN-γ expression and increased IL-17a expression in activated CD4+ T cells. However, the cytotoxic activity of CD8+ T cells was not altered by colorectal cancer cells. To further evaluate the importance of Wnt signaling for CD4+ T cell-mediated cancer immunity, β-catenin expression was enforced in CD4+ T cells using lentiviral transduction. In an adoptive transfer model, enforced expression of β-catenin in intratumoral CD4+ T cells increased IL-17a expression, enhanced proliferation and inhibited apoptosis of colorectal cancer cells. Taken together, our study disclosed a new mechanism by which colorectal cancer impairs T cell immunity.

Dominant Suppression of β1 Integrin by Ectopic CD98-ICD Inhibits Hepatocellular Carcinoma Progression

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Bo Wu

2016-11-01

Full Text Available Hepatocellular carcinoma (HCC is currently the third most common cause of cancer-related death in the Asia-Pacific region. Our previous work showed that knockdown of CD98 significantly inhibits malignant HCC cell phenotypes in vitro and in vivo. The level of CD98 in the membrane is tightly regulated to mediate complex processes associated with cell–cell communication and intracellular signaling. In addition, the intracellular domain of CD98 (CD98-ICD seems to be of vital importance for recycling CD98 to the membrane after it is endocytosed. The intracellular and transmembrane domains of CD98 associate with β-integrins (primarily β1 but also β3, and this association is essential for CD98 mediation of integrin-like signaling and complements dominant suppression of β1-integrin. We speculated that isolated CD98-ICD would similarly suppress β1-integrin activation and inhibit the malignant behaviors of cancer cells. In particular, the exact role of CD98-ICD has not been studied independently in HCC. In this study, we found that ectopic expression of CD98-ICD inhibited the malignant phenotypes of HCC cells, and the mechanism possibly involves β1-integrin suppression. Moreover, the expression levels of CD98, β1-integrin-A (the activated form of β1-integrin and Ki-67 were significantly increased in HCC tissues relative to those of normal liver tissues. Therefore, our preliminary study indicates that ectopic CD98-ICD has an inhibitory role in the malignant development of HCC, and shows that CD98-ICD acts as a dominant negative mutant of CD98 that attenuates β1-integrin activation. CD98-ICD may emerge as a promising candidate for antitumor treatment.

Cd4As2Br3

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Mohammed Kars

2014-03-01

Full Text Available Single crystals of Cd4As2Br3 (tetracadmium biarsenide tribromide were grown by a chemical transport reaction. The structure is isotypic with the members of the cadmium and mercury pnictidohalides family with general formula M4A2X3 (M = Cd, Hg; A = P, As, Sb; X = Cl, Br, I and contains two independent As atoms on special positions with site symmetry -3 and two independent Cd atoms, of which one is on a special position with site symmetry -3. The Cd4As2Br3 structure consists of AsCd4 tetrahedra sharing vertices with isolated As2Cd6 octahedra that contain As–As dumbbells in the centre of the octahedron. The Br atoms are located in the voids of this three-dimensional arrangement and bridge the different polyhedra through Cd...Br contacts.

Red Wine Inhibits Aggregation and Increases ATP-diphosphohydrolase (CD39) Activity of Rat Platelets in Vitro.

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Caiazzo, Elisabetta; Tedesco, Idolo; Spagnuolo, Carmela; Russo, Gian Luigi; Ialenti, Armando; Cicala, Carla

2016-06-01

Moderate consumption of red wine has been shown to exert a peculiar cardioprotective effect compared with other alcoholic beverages; inhibition of platelet aggregation seems to be one of the mechanisms underlying this beneficial effect. CD39/ATP-diphosphohydrolase is an integral membrane glycoprotein metabolizing ATP and ADP to AMP; in concert with CD73/ecto-5'-nucleotidase, it contributes to extracellular adenosine accumulation. CD39 is considered a key modulator of thrombus formation; it inhibits platelet aggregation by promoting ADP hydrolysis. There is evidence that red wine consumption increases CD39 activity in platelets from streptozotocin-induced diabetic rats. Here we show that two kinds of Aglianico red wines inhibit aggregation and increase ATP--and ADPase activity in rat platelets.

Calcineurin B in CD4+ T Cells Prevents Autoimmune Colitis by Negatively Regulating the JAK/STAT Pathway.

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Mencarelli, Andrea; Vacca, Maurizio; Khameneh, Hanif Javanmard; Acerbi, Enzo; Tay, Alicia; Zolezzi, Francesca; Poidinger, Michael; Mortellaro, Alessandra

2018-01-01

Calcineurin (Cn) is a protein phosphatase that regulates the activation of the nuclear factor of activated T-cells (NFAT) family of transcription factors, which are key regulators of T-cell development and function. Here, we generated a conditional Cnb1 mouse model in which Cnb1 was specifically deleted in CD4 + T cells (Cnb1 CD4 mice) to delineate the role of the Cn-NFAT pathway in immune homeostasis of the intestine. The Cnb1 CD4 mice developed severe, spontaneous colitis characterized at the molecular level by an increased T helper-1-cell response but an unaltered regulatory T-cell compartment. Antibiotic treatment ameliorated the intestinal inflammation observed in Cnb1 CD4 mice, suggesting that the microbiota contributes to the onset of colitis. CD4 + T cells isolated from Cnb1 CD4 mice produced high levels of IFNγ due to increased activation of the JAK2/STAT4 pathway induced by IL-12. Our data highlight that Cn signaling in CD4 + T cells is critical for intestinal immune homeostasis in part by inhibiting IL-12 responsiveness of CD4 + T cells.

Cell-contact-dependent activation of CD4+ T cells by adhesion molecules on synovial fibroblasts.

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Mori, Masato; Hashimoto, Motomu; Matsuo, Takashi; Fujii, Takao; Furu, Moritoshi; Ito, Hiromu; Yoshitomi, Hiroyuki; Hirose, Jun; Ito, Yoshinaga; Akizuki, Shuji; Nakashima, Ran; Imura, Yoshitaka; Yukawa, Naoichiro; Yoshifuji, Hajime; Ohmura, Koichiro; Mimori, Tsuneyo

2017-05-01

To determine how cell-cell contact with synovial fibroblasts (SF) influence on the proliferation and cytokine production of CD4 +  T cells. Naïve CD4 +  T cells were cultured with SF from rheumatoid arthritis patients, stimulated by anti-CD3/28 antibody, and CD4 +  T cell proliferation and IFN-γ/IL-17 production were analyzed. To study the role of adhesion molecules, cell contact was blocked by transwell plate or anti-intracellular adhesion molecule-1 (ICAM-1)/vascular cell adhesion molecule-1(VCAM-1) antibody. To study the direct role of adhesion molecules for CD4 +  T cells, CD161 +  or CD161 - naïve CD4 +  T cells were stimulated on plastic plates coated by recombinant ICAM-1 or VCAM-1, and the source of IFN-γ/IL-17 were analyzed. SF enhanced naïve CD4 +  T cell proliferation and IFN-γ/IL-17 production in cell-contact and in part ICAM-1-/VCAM-1-dependent manner. Plate-coated ICAM-1 and VCAM-1 enhanced naïve CD4 +  T cell proliferation and IFN-γ production, while VCAM-1 efficiently promoting IL-17 production. CD161 +  naïve T cells upregulating LFA-1 and VLA-4 were the major source of IFN-γ/IL-17 upon interaction with ICAM-1/VCAM-1. CD4 +  T cells rapidly expand and secrete IFN-γ/IL-17 upon cell-contact with SF via adhesion molecules. Interfering with ICAM-1-/VCAM-1 may be beneficial for inhibiting RA synovitis.

Phenotype and Function of CD209+ Bovine Blood Dendritic Cells, Monocyte-Derived-Dendritic Cells and Monocyte-Derived Macrophages.

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Kun Taek Park

Full Text Available Phylogenic comparisons of the mononuclear phagocyte system (MPS of humans and mice demonstrate phenotypic divergence of dendritic cell (DC subsets that play similar roles in innate and adaptive immunity. Although differing in phenotype, DC can be classified into four groups according to ontogeny and function: conventional DC (cDC1 and cDC2, plasmacytoid DC (pDC, and monocyte derived DC (MoDC. DC of Artiodactyla (pigs and ruminants can also be sub-classified using this system, allowing direct functional and phenotypic comparison of MoDC and other DC subsets trafficking in blood (bDC. Because of the high volume of blood collections required to study DC, cattle offer the best opportunity to further our understanding of bDC and MoDC function in an outbred large animal species. As reported here, phenotyping DC using a monoclonal antibody (mAb to CD209 revealed CD209 is expressed on the major myeloid population of DC present in blood and MoDC, providing a phenotypic link between these two subsets. Additionally, the present study demonstrates that CD209 is also expressed on monocyte derived macrophages (MoΦ. Functional analysis revealed each of these populations can take up and process antigens (Ags, present them to CD4 and CD8 T cells, and elicit a T-cell recall response. Thus, bDC, MoDC, and MoΦ pulsed with pathogens or candidate vaccine antigens can be used to study factors that modulate DC-driven T-cell priming and differentiation ex vivo.

Distribution of dendritic cells expressing dendritic cell-specific ICAM-3-grabbing non-integrin (DC-SIGN, CD209): Morphological analysis using a novel Photoshop-aided multiple immunohistochemistry technique.

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Masuda, Akihiro; Nishikawa, Toshio

2014-08-01

The distribution of dendritic cells (DCs) expressing DC-specific ICAM-3-grabbing non-integrin (DC-SIGN, CD209) and the morphological interaction of DC-SIGN⁺ DCs with other cells, especially B cells, in tonsillar and other lymphoid tissues were investigated by multiple immunohistochemistry (IHC) using the graphics editing program Photoshop, which enabled staining with 4 or more antibodies in formalin-fixed paraffin sections. Images obtained by repetition of conventional IHC using diaminobenzidine color development in a tissue section were processed on Photoshop for multiple staining. DC-SIGN⁺ DCs were present in the area around the lymphoid follicles and formed a DC-SIGN⁺ DC-rich area, and these cells contacted not only T cells, fascin⁺ DCs, and blood vessels but also several subsets of B cells simultaneously, including naïve and memory B cells. DC-SIGN⁺ DCs may play an important role in the regulation of the immune response mediated by not only T cells but also B cells. The multiple IHC method introduced in the present study is a simple and useful method for analyzing details of complex structures. Because this method can be applied to routinely processed paraffin sections with conventional IHC with diaminobenzidine, it can be applied to a wide variety of archival specimens.

CD4-regulatory cells in COPD patients

DEFF Research Database (Denmark)

Smyth, Lucy J C; Starkey, Cerys; Vestbo, Jørgen

2007-01-01

BACKGROUND: The numbers of airway CD8 and B lymphocytes are increased in COPD patients, suggesting an autoimmune process. CD4-regulatory T cells control autoimmunity but have not been studied in patients with COPD. OBJECTIVE: To compare T-regulatory cell numbers in the BAL from COPD patients......, smokers with normal lung function, and healthy nonsmokers (HNS). METHODS: BAL and peripheral blood mononuclear cell (PBMC) samples were obtained from 26 COPD patients, 19 smokers, and 8 HNS. Flow cytometry was performed for regulatory phenotypic markers. RESULTS: COPD patients had increased BAL CD8...... numbers compared to smokers and HNS. CD4 numbers were similar between groups. There was increased BAL CD4CD25(bright) expression in smokers (median 28.8%) and COPD patients (median 23.1%) compared to HNS (median 0%). Increased FoxP3 expression was confirmed in BAL CD4CD25(bright) cells. BAL CD4CD25 cells...

CP-25 attenuates the inflammatory response of fibroblast-like synoviocytes co-cultured with BAFF-activated CD4(+) T cells.

Science.gov (United States)

Jia, Xiaoyi; Wei, Fang; Sun, Xiaojing; Chang, Yan; Xu, Shu; Yang, Xuezhi; Wang, Chun; Wei, Wei

2016-08-02

Total glucosides of paeony (TGP) is the first anti-inflammatory immune regulatory drug approved for the treatment of rheumatoid arthritis in China. A novel compound, paeoniflorin-6'-O-benzene sulfonate (code CP-25), comes from the structural modification of paeoniflorin (Pae), which is the effective active ingredient of TGP. The aim of the present study is to investigate the effect of CP-25 on adjuvant arthritis (AA) fibroblast-like synoviocytes (FLS) co-cultured with BAFF-activated CD4(+) T cells and the expression of BAFF-R in CD4(+) T cells. The mRNA expression of BAFF and its receptors was assessed by qPCR. The expression of BAFF receptors in CD4(+) T cells was analyzed by flow cytometry. The effect of CP-25 on AA rats was evaluated by their joint histopathology. The cell culture growth of thymocytes and FLS was detected by cell counting kit (CCK-8). The concentrations of IL-1β, TNF-α, and IL-6 were measured by Enzyme-linked immunosorbent assay (ELISA). The mRNA expression levels of BAFF and BAFF-R were enhanced in the mesenteric lymph nodes of AA rats, TACI expression was reduced, and BCMA had no change. The expression of BAFF-R in CD4(+) T cells was also enhanced. CP-25 alleviated the joint histopathology and decreased the expression of BAFF-R in CD4(+) T cells from AA rats in vivo. In vitro, CP-25 inhibited the abnormal cell culture growth of BAFF-stimulated thymocytes and FLS. In the co-culture system, IL-1β, IL-6 and TNF-α production was enhanced by FLS co-cultured with BAFF-activated CD4(+) T cells. Moreover, BAFF-stimulated CD4(+) T cells promoted the cell culture growth of FLS. The addition of CP-25 decreased the expression of BAFF-R in CD4(+) T cells and inhibited the cell culture growth and cytokine secretion ability of FLS co-cultured with BAFF-activated CD4(+) T cells. The present study indicates that CP-25 may repress the cell culture growth and cytokine secretion ability of FLS, and its inhibitory effects might be associated with its ability

CD4 T cell knockout does not protect against kidney injury and worsens cancer.

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Ravichandran, Kameswaran; Wang, Qian; Ozkok, Abdullah; Jani, Alkesh; Li, Howard; He, Zhibin; Ljubanovic, Danica; Weiser-Evans, Mary C; Nemenoff, Raphael A; Edelstein, Charles L

2016-04-01

Most previous studies of cisplatin-induced acute kidney injury (AKI) have been in models of acute, high-dose cisplatin administration that leads to mortality in non-tumor-bearing mice. The aim of the study was to determine whether CD4 T cell knockout protects against AKI and cancer in a clinically relevant model of low-dose cisplatin-induced AKI in mice with cancer. Kidney function, serum neutrophil gelatinase-associated lipocalin (NGAL), acute tubular necrosis (ATN), and tubular apoptosis score were the same in wild-type and CD4 -/- mice with AKI. The lack of protection against AKI in CD4 -/- mice was associated with an increase in extracellular signal-regulated kinase (ERK), p38, CXCL1, and TNF-α, mediators of AKI and fibrosis, in both cisplatin-treated CD4 -/- mice and wild-type mice. The lack of protection was independent of the presence of cancer or not. Tumor size was double, and cisplatin had an impaired therapeutic effect on the tumors in CD4 -/- vs. wild-type mice. Mice depleted of CD4 T cells using the GK1.5 antibody were not protected against AKI and had larger tumors and lesser response to cisplatin. In summary, in a clinically relevant model of cisplatin-induced AKI in mice with cancer, (1) CD4 -/- mice were not protected against AKI; (2) ERK, p38, CXCL1, and TNF-α, known mediators of AKI, and interstitial fibrosis were increased in CD4 -/- kidneys; and (3) CD4 -/- mice had faster tumor growth and an impaired therapeutic effect of cisplatin on the tumors. The data warns against the use of CD4 T cell inhibition to attenuate cisplatin-induced AKI in patients with cancer. A clinically relevant low-dose cisplatin model of AKI in mice with cancer was used. CD4 -/- mice were not functionally or histologically protected against AKI. CD4 -/- mice had faster tumor growth. CD4 -/- mice had an impaired therapeutic effect of cisplatin on the tumors. Mice depleted of CD4 T cells were not protected against AKI and had larger tumors.

A plasmacytoid dendritic cell (CD123+/CD11c-) based assay system to predict contact allergenicity of chemicals

Science.gov (United States)

Ayehunie, Seyoum; Snell, Maureen; Child, Matthew; Klausner, Mitchell

2009-01-01

A predictive allergenicity test system for assessing the contact allergenicity of chemicals is needed by the cosmetic and pharmaceutical industry to monitor product safety in the marketplace. Development of such non-animal alternative assay systems for skin sensitization and hazard identification has been pursued by policy makers and regulatory agencies. We investigated whether phenotypic and functional changes to a subset of dendritic cells (DC), plasmacytoid DC (pDC), could be used to identify contact allergens. To achieve this goal, normal human DC were generated from CD34+ progenitor cells and cryopreserved. Frozen DC were thawed and the pDC fraction (CD123+/CD11c-) was harvested using FACS sorting. The pDC were cultured, expanded, and exposed to chemical allergens (N=26) or non-allergens (N=22). Concentrations of each chemical that resulted in >50% viability was determined using FACS analysis of propidium iodide stained cells using pDC from 2-5 donors. Expression of the surface marker, CD86, which has been implicated in dendritic cell maturation, was used as a marker of allergenicity. CD86 expression increased (≥ 1.5 fold) for 25 of 26 allergens (sensitivity = 96%) but did not increase for 19 of 22 non-allergens (specificity = 86%). In a direct comparison to historical data for the regulatory approved, mouse local lymph node assay (LLNA) for 23 allergens and 22 non-allergens, the pDC method had sensitivity and specificity of 96% and 86%, respectively, while the sensitivity and specificity of the LLNA assay was 83% and 82%, respectively. In conclusion, CD86 expression in pDC appears to be a sensitive and specific indicator to identify contact allergenicity. Such an assay method utilizing normal human cells will be useful for high throughput screening of chemicals for allergenicity. PMID:19665512

A plasmacytoid dendritic cell (CD123+/CD11c-) based assay system to predict contact allergenicity of chemicals

International Nuclear Information System (INIS)

Ayehunie, Seyoum; Snell, Maureen; Child, Matthew; Klausner, Mitchell

2009-01-01

A predictive allergenicity test system for assessing the contact allergenicity of chemicals is needed by the cosmetic and pharmaceutical industry to monitor product safety in the marketplace. Development of such non-animal alternative assay systems for skin sensitization and hazard identification has been pursued by policy makers and regulatory agencies. We investigated whether phenotypic and functional changes to a subset of dendritic cells (DC), plasmacytoid DC (pDC), could be used to identify contact allergens. To achieve this goal, normal human DC were generated from CD34+ progenitor cells and cryopreserved. Frozen DC were thawed and the pDC fraction (CD123+/CD11c-) was harvested using FACS sorting. The pDC were cultured, expanded, and exposed to chemical allergens (N = 26) or non-allergens (N = 22). Concentrations of each chemical that resulted in >50% viability was determined using FACS analysis of propidium iodide stained cells using pDC from 2 to 5 donors. Expression of the surface marker, CD86, which has been implicated in dendritic cell maturation, was used as a marker of allergenicity. CD86 expression increased (≥1.5-fold) for 25 of 26 allergens (sensitivity = 96%) but did not increase for 19 of 22 non-allergens (specificity = 86%). In a direct comparison to historical data for the regulatory approved, mouse local lymph node assay (LLNA) for 23 allergens and 22 non-allergens, the pDC method had sensitivity and specificity of 96% and 86%, respectively, while the sensitivity and specificity of the LLNA assay was 83% and 82%, respectively. In conclusion, CD86 expression in pDC appears to be a sensitive and specific indicator to identify contact allergenicity. Such an assay method utilizing normal human cells will be useful for high throughput screening of chemicals for allergenicity.

CD4-binding site alterations in CCR5-using HIV-1 envelopes influencing gp120-CD4 interactions and fusogenicity

International Nuclear Information System (INIS)

Sterjovski, Jasminka; Churchill, Melissa J.; Roche, Michael; Ellett, Anne; Farrugia, William; Wesselingh, Steven L.; Cunningham, Anthony L.; Ramsland, Paul A.; Gorry, Paul R.

2011-01-01

CD4-binding site (CD4bs) alterations in gp120 contribute to different pathophysiological phenotypes of CCR5-using (R5) HIV-1 strains, but the potential structural basis is unknown. Here, we characterized functionally diverse R5 envelope (Env) clones (n = 16) to elucidate potential structural alterations within the gp120 CD4bs that influence Env function. Initially, we showed that the magnitude of gp120-CD4-binding correlates with increased fusogenicity and reduced CD4 dependence. Analysis of three-dimensional gp120 structural models revealed two CD4bs variants, D279 and N362, that were associated with reduced CD4 dependence. Further structural analysis showed that a wider aperture of the predicted CD4bs cavity, as constrained by the inner-most atoms at the gp120 V1V2 stem and the V5 loop, was associated with amino acid alterations within V5 and correlated with increased gp120-CD4 binding and increased fusogenicity. Our results provide evidence that the gp120 V5 loop may alter CD4bs conformation and contribute to increased gp120-CD4 interactions and Env fusogenicity.

Increase of circulating CD4+CD25highFoxp3+ regulatory T cells in patients with metastatic renal cell carcinoma during treatment with dendritic cell vaccination and low-dose interleukin-2

DEFF Research Database (Denmark)

Berntsen, Annika; Brimnes, Marie Klinge; thor Straten, Per

2010-01-01

Regulatory T cells (Treg) play an important role in the maintenance of immune tolerance and may be one of the obstacles of successful tumor immunotherapy. In this study, we analyzed the impact of administration of dendritic cell (DC) vaccination in combination with low-dose interleukin (IL)-2...... in patients with metastatic renal cell carcinoma on the frequency of CD4+CD25highFoxp3+ Treg cells in peripheral blood. We found that the treatment increased the frequency of Treg cells more than 7-fold compared with pretreatment levels (P...

CD4 down regulation and raft dissociation by the non-depleting YTS177 antibody hinder murine T helper cell activities

Energy Technology Data Exchange (ETDEWEB)

Wu, Cheng-Jang [Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan (China); Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093 (United States); Lu, Chun-Hao [Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan (China); Chen, Li-Chen [Division of Allergy, Asthma, and Rheumatology, Department of Pediatrics, Chang Gung Memorial Hospital, Tao-Yuan, Taiwan (China); Nguyen, Duc T. [Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093 (United States); Huang, Yi-Shu [Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan (China); Lin, Hsi-Hsien [Department of Microbiology and Immunology, Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan (China); Chang Gung Immunology Consortium, Chang Gung Memorial Hospital and Chang Gung University, Tao-Yuan, Taiwan (China); Department of Anatomic Pathology, Chang Gung Memorial Hospital, Tao-Yuan, Taiwan (China); Lin, Chun-Yen [Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan (China); Chang Gung Immunology Consortium, Chang Gung Memorial Hospital and Chang Gung University, Tao-Yuan, Taiwan (China); Department of Hepatogastroenterology, Chang Gung Memorial Hospital, Tao-Yuan, Taiwan (China); Kuo, Ming-Ling, E-mail: mingling@mail.cgu.edu.tw [Department of Microbiology and Immunology, Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan (China); Division of Allergy, Asthma, and Rheumatology, Department of Pediatrics, Chang Gung Memorial Hospital, Tao-Yuan, Taiwan (China); Chang Gung Immunology Consortium, Chang Gung Memorial Hospital and Chang Gung University, Tao-Yuan, Taiwan (China)

2016-05-13

Non-depleting YTS177 anti-CD4 monoclonal antibody (MoAb) has been reported to lead to antigen-specific immunotolerance in allograft transplantation and autoimmune diabetes, as well as possibly to inhibition of allergic inflammation in mice. However, the molecular mechanisms underlying hyporesponsive T cell responses induced by YTS177 MoAb remain elusive. Herein, we demonstrate that the YTS177 MoAb increases the levels of anergy factors p27{sup kip1} and Cbl-b, inhibits IL-2 production, and impairs calcium mobilization in activated T cells in vitro. YTS177 MoAb suppresses OVA-driven proliferation of DO11.10 CD4{sup +} T cells in vivo as well. Mechanistically, YTS177 MoAb induces tolerance by causing CD4 down-regulation through clathrin-dependent and raft dissociation. The results obtained in this study lead us to propose novel protective or curative approaches to CD4 T cell-mediated diseases.

CD4 down regulation and raft dissociation by the non-depleting YTS177 antibody hinder murine T helper cell activities

International Nuclear Information System (INIS)

Wu, Cheng-Jang; Lu, Chun-Hao; Chen, Li-Chen; Nguyen, Duc T.; Huang, Yi-Shu; Lin, Hsi-Hsien; Lin, Chun-Yen; Kuo, Ming-Ling

2016-01-01

Non-depleting YTS177 anti-CD4 monoclonal antibody (MoAb) has been reported to lead to antigen-specific immunotolerance in allograft transplantation and autoimmune diabetes, as well as possibly to inhibition of allergic inflammation in mice. However, the molecular mechanisms underlying hyporesponsive T cell responses induced by YTS177 MoAb remain elusive. Herein, we demonstrate that the YTS177 MoAb increases the levels of anergy factors p27"k"i"p"1 and Cbl-b, inhibits IL-2 production, and impairs calcium mobilization in activated T cells in vitro. YTS177 MoAb suppresses OVA-driven proliferation of DO11.10 CD4"+ T cells in vivo as well. Mechanistically, YTS177 MoAb induces tolerance by causing CD4 down-regulation through clathrin-dependent and raft dissociation. The results obtained in this study lead us to propose novel protective or curative approaches to CD4 T cell-mediated diseases.

CD28 co-stimulation down regulates Th17 development.

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Salim Bouguermouh

Full Text Available Th17 cells are implicated in host defence and autoimmune diseases. CD28/B7 co-stimulation is involved in the induction and progression of autoimmune diseases, but its role in controlling murine Th17 cell fate remains to be clarified. We here report that soluble anti-CD28 mAb suppressed the differentiation of anti-CD3-stimulated naïve CD4(+ T cells into IL-17-producing cells. CD28 co-stimulation reduced the frequency of proliferating cells that produce IL-17. We provide evidence for an IL-2 and IFN-gamma-dependent mechanism of CD28-mediated IL-17 suppression. CD28 blockade of Th17 development was correlated with a decrease rather than an increase in the percentage of Foxp3(+ T cells. In APC/T cell co-cultures, mature dendritic cells (DC were less efficient than immature DC in their ability to support Th17 cell differentiation, while CTLA4-Ig, an agent blocking CD28/B7 and CTLA4/B7 interactions, facilitated both murine and human Th17 differentiation. This study identifies the importance of B7 co-stimulatory molecules in the negative regulation of Th17 development. These unexpected results caution targeting the CD28/B7 pathways in the treatment of human autoimmune diseases.

Biomarker screening of oral cancer cell lines revealed sub-populations of CD133-, CD44-, CD24- and ALDH1- positive cancer stem cells

Directory of Open Access Journals (Sweden)

Kendall K

2013-05-01

Full Text Available Head and neck squamous cell carcinoma (HNSCC ranks sixth worldwide for cancer-related mortality. For the past several decades the mainstay of treatment for HNSCC has been surgery and external beam radiation, although more recent trials combining chemotherapy and radiation have demonstrated improvements. However, cancer recurrence and treatment failures continue to occur in a significant percentage of patients. Recent advances in tumor biology have led to the discovery that many cancers, including HNSCC, may contain subpopulations of cells with stem cell-like properties that may explain relapse and recurrence. The objective of this study was to screen existing oral cancer cell lines for biomarkers specific for cells with stem cell-like properties. RNA was isolated for RT-PCR screening using primers for specific mRNA of the biomarkers: CD44, CD24, CD133, NANOG, Nestin, ALDH1, and ABCG2 in CAL27, SCC25 and SCC15 cells. This analysis revealed that some oral cancer cell lines (CAL27 and SCC25 may contain small subpopulations of adhesion- and contact-independent cells (AiDC that also express tumor stem cell markers, including CD44, CD133, and CD24. In addition, CAL27 cells also expressed the intracellular tumor stem cell markers, ALDH1 and ABCG2. Isolation and culture of the adhesion- and contact-independent cells from CAL27 and SCC25 populations revealed differential proliferation rates and more robust inhibition by the MEK inhibitor PD98059, as well as the chemotherapeutic agents Cisplatin and Paclitaxel, within the AiDC CAL27 cells. At least one oral cancer cell line (CAL27 contained subpopulations of cells that express specific biomarkers associated with tumor stem cells which were morphologically and phenotypically distinct from other cells within this cell line.

Requirement for CD4 T Cell Help in Generating Functional CD8 T Cell Memory

Science.gov (United States)

Shedlock, Devon J.; Shen, Hao

2003-04-01

Although primary CD8 responses to acute infections are independent of CD4 help, it is unknown whether a similar situation applies to secondary responses. We show that depletion of CD4 cells during the recall response has minimal effect, whereas depletion during the priming phase leads to reduced responses by memory CD8 cells to reinfection. Memory CD8 cells generated in CD4+/+ mice responded normally when transferred into CD4-/- hosts, whereas memory CD8 cells generated in CD4-/- mice mounted defective recall responses in CD4+/+ adoptive hosts. These results demonstrate a previously undescribed role for CD4 help in the development of functional CD8 memory.

IL-2 and IL-15 regulate CD154 expression on activated CD4 T cells

DEFF Research Database (Denmark)

Skov, S; Bonyhadi, M; Odum, Niels

2000-01-01

The cellular and humoral immune system is critically dependent upon CD40-CD154 (CD40 ligand) interactions between CD40 expressed on B cells, macrophages, and dendritic cells, and CD154 expressed primarily on CD4 T cells. Previous studies have shown that CD154 is transiently expressed on CD4 T cells...... after T cell receptor engagement in vitro. However, we found that stimulation of PBLs with maximal CD28 costimulation, using beads coupled to Abs against CD3 and CD28, led to a very prolonged expression of CD154 on CD4 cells (>4 days) that was dependent upon autocrine IL-2 production. Previously...... activated CD4 T cells could respond to IL-2, or the related cytokine IL-15, by de novo CD154 production and expression without requiring an additional signal from CD3 and CD28. These results provide evidence that CD28 costimulation of CD4 T cells, through autocrine IL-2 production, maintains high levels...

Broad-spectrum inhibition of HIV-1 by a monoclonal antibody directed against a gp120-induced epitope of CD4.

Science.gov (United States)

Burastero, Samuele E; Frigerio, Barbara; Lopalco, Lucia; Sironi, Francesca; Breda, Daniela; Longhi, Renato; Scarlatti, Gabriella; Canevari, Silvana; Figini, Mariangela; Lusso, Paolo

2011-01-01

To penetrate susceptible cells, HIV-1 sequentially interacts with two highly conserved cellular receptors, CD4 and a chemokine receptor like CCR5 or CXCR4. Monoclonal antibodies (MAbs) directed against such receptors are currently under clinical investigation as potential preventive or therapeutic agents. We immunized Balb/c mice with molecular complexes of the native, trimeric HIV-1 envelope (Env) bound to a soluble form of the human CD4 receptor. Sera from immunized mice were found to contain gp120-CD4 complex-enhanced antibodies and showed broad-spectrum HIV-1-inhibitory activity. A proportion of MAbs derived from these mice preferentially recognized complex-enhanced epitopes. In particular, a CD4-specific MAb designated DB81 (IgG1Κ) was found to preferentially bind to a complex-enhanced epitope on the D2 domain of human CD4. MAb DB81 also recognized chimpanzee CD4, but not baboon or macaque CD4, which exhibit sequence divergence in the D2 domain. Functionally, MAb DB81 displayed broad HIV-1-inhibitory activity, but it did not exert suppressive effects on T-cell activation in vitro. The variable regions of the heavy and light chains of MAb DB81 were sequenced. Due to its broad-spectrum anti-HIV-1 activity and lack of immunosuppressive effects, a humanized derivative of MAb DB81 could provide a useful complement to current preventive or therapeutic strategies against HIV-1.