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CD25+ T Cells (cd25+ t + cell)
Kinds of CD25+ T Cells Selected AbstractsMHC class II-independent CD25+ CD4+ CD8,,,+ ,,, T cells attenuate CD4+ T cell-induced transfer colitisEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 3 2004Tamara Krajina Abstract CD4+ ,,, T cell populations that develop in mice deficient in MHC class II (through ,knockout' of either the A,, or the A, chain of the I-Ab molecule) comprise a major ,single-positive' (SP) CD4+ CD8, subset (60,90%) and a minor ,double-positive' (DP) CD4+ CD8,,,+ subset (10,40%). Many DP T cells found in spleen, mesenteric lymph nodes (MLN) and colonic lamina propria (cLP) express CD25, CD103 and Foxp3. Adoptive transfer of SP but not DP T cells from A,,/, or A,,/, B6 mice into congenic RAG,/, hosts induces colitis. Transfer of SP T cells repopulates the host with only SP T cells; transfer of DP T cells repopulates the host with DP and SP T cells. Anti-CD25 antibody treatment of mice transplanted with DP T cells induces severe, lethal colitis; anti-CD25 antibody treatment of mice transplanted with SP T cells further aggravates the course of severe colitis. Hence, regulatory CD25+ T cells within (or developing from) the DP T cell population of MHC class II-deficient mice control the colitogenic potential of CD25, CD4+ T cells. [source] Control of T-cell activation by CD4+ CD25+ suppressor T cellsIMMUNOLOGICAL REVIEWS, Issue 1 2001Ethan M. Shevach Summary: Depletion of the minor (,10%) subpopulation of CD4+ T cells that co-expresses CD25 (interleukin (IL)-2 receptor ,-chain) by thymectomy of neonates on the third day of life or by treatment of adult CD4+ T cells with anti-CD25 and complement results in the development of organ-specific autoimmunity. Autoimmune disease can be prevented by reconstitution of the animals with CD4+ CD25+ cells. CD4+ CD25+ -mediated protection of autoimmune gastritis does not require the suppressor cytokines IL-4, IL-10, or transforming growth factor (TGF)-,. Mice that express a transgenic T-cell receptor (TCR) derived from a thymectomized newborn that recognizes the gastric parietal cell antigen H/K ATPase all develop severe autoimmune gastritis very early in life. CD4+ CD25+ T cells are also powerful suppressors of the activation of both CD4+ and CD8+ T cells in vitro. Suppression is mediated by a cell contact-dependent, cytokine-independent T,T interaction. Activation of CD4+ CD25+ via their TCR generates suppressor effector cells that are capable of non-specifically suppressing the activation of any CD4+ or CD8+ T cell. Activation of suppressor effector function is independent of co-stimulation mediated by CD28/CTLA-4 interactions with CD80/CD86. We propose that CD4+ CD25+ T cells recognize organ-specific antigens, are recruited to sites of autoimmune damage where they are activated by their target antigen, and then physically interact with autoreactive CD4+ or CD8+ effector cells to suppress the development of autoimmune disease. [source] Suppression of allergic airway inflammation in a mouse model by Der p2 recombined BCGIMMUNOLOGY, Issue 1pt2 2009Hai-Feng Ou-Yang Summary Allergic asthma is a chronic inflammatory disease mediated by T helper (Th)2 cell immune responses. Currently, immunotherapies based on both immune deviation and immune suppression, including the development of recombinant mycobacteria as immunoregulatory vaccines, are attractive treatment strategies for asthma. In our previous studies, we created a genetically recombinant form of bacille Calmette,Guerin (rBCG) that expressed Der p2 of house dust mites and established that it induced a shift from a Th2 response to a Th1 response in naive mice. However, it is unclear whether rBCG could suppress allergic airway inflammation in a mouse model. In this article we report that rBCG dramatically inhibited airway inflammation, eosinophilia, mucus production and mast cell degranulation in allergic mice. Analysis of interferon-, (IFN-,) and interleukin-4 (IL-4) levels in bronchoalveolar lavage fluid (BALF) and lung tissue revealed that the suppression was associated with a shift from a Th2 response to a Th1 response. At the same time, rBCG induced a CD4+ CD25+ Foxp3+ T-cell subtype that could suppress the proliferation of Th2 effector cells in vitro in an antigen-specific manner. Moreover, suppression of CD4+ CD25+ T cells could be adoptively transferred. Thus, our results demonstrate that rBCG induces both generic and specific immune responses. The generic immune response is associated with a shift from a Th2 to a Th1 cytokine response, whereas the specific immune response against Der p2 appears to be related to the expansion of transforming growth factor-, (TGF-,)-producing CD4+ CD25+ Foxp3+ regulatory T cells. rBCG can suppress asthmatic airway inflammation through both immune deviation and immune suppression and may be a feasible, efficient immunotherapy for asthma. [source] Toll-like receptors and immune regulation: their direct and indirect modulation on regulatory CD4+ CD25+ T cellsIMMUNOLOGY, Issue 2 2007Guangwei Liu Summary Regulatory CD4+ CD25+ T (Treg) cells with the ability to suppress host immune responses against self- or non-self antigens play important roles in the processes of autoimmunity, transplant rejection, infectious diseases and cancers. The proper regulation of CD4+ CD25+ Treg cells is thus critical for optimal immune responses. Toll-like receptor (TLR)-mediated recognition of specific structures of invading pathogens initiates innate as well as adaptive immune responses via antigen-presenting cells (APCs). Interestingly, new evidence suggests that TLR signalling may directly or indirectly regulate the immunosuppressive function of CD4+ CD25+ Treg cells in immune responses. TLR signalling may shift the balance between CD4+ T-helper cells and Treg cells, and subsequently influence the outcome of the immune response. This immunomodulation pathway may therefore have potential applications in the treatment of graft rejection, autoimmune diseases, infection diseases and cancers. [source] Regulation of tumour immunity by CD25+ T cellsIMMUNOLOGY, Issue 1 2002Awen Gallimore First page of article [source] Hypersensitivity and oral tolerance in the absence of a secretory immune systemALLERGY, Issue 5 2010M. R. Karlsson To cite this article: Karlsson M-R, Johansen F-E, Kahu H, Macpherson A, Brandtzaeg P. Hypersensitivity and oral tolerance in the absence of a secretory immune system. Allergy 2010; 65: 561,570. Abstract Background:, Mucosal immunity protects the epithelial barrier by immune exclusion of foreign antigens and by anti-inflammatory tolerance mechanisms, but there is a continuing debate about the role of secretory immunoglobulins (SIgs), particularly SIgA, in the protection against allergy and other inflammatory diseases. Lack of secretory antibodies may cause immune dysfunction and affect mucosally induced (oral) tolerance against food antigens. Methods:, We used polymeric Ig receptor (pIgR) knockout (KO) mice, which cannot export SIgA or SIgM, to study oral tolerance induction by ovalbumin (OVA) feeding and for parenteral antigen sensitization in the same animal. Results:, Remarkable systemic hyperreactivity was observed in pIgR KO mice, as 50% died after intradermal OVA challenge, which was not seen in similarly sensitized and challenged wild-type (WT) mice. Oral tolerance induced by OVA completely protected the sensitized pIgR KO mice against anaphylaxis and suppressed antibody levels (particularly IgG1) as well as delayed-type hypersensitivity (DTH) to OVA. Delayed-type hypersensitivity to a bystander antigen, human serum albumin, was also suppressed and T-cell proliferation against OVA in vitro was reduced in tolerized compared with non-tolerized pIgR KO mice. This effect was largely mediated by CD25+ T cells. Adoptive transfer of splenic putative regulatory T cells (CD4+ CD25+) obtained from OVA-fed pIgR KO mice to naïve WT mice mediated suppression of DTH against OVA after sensitization of the recipients. Conclusion:, Compensatory regulatory T-cell function becomes critical in pIgR-deficient mice to avoid the potentially catastrophic effects of systemic immune hyperreactivity, presumably resulting from defective secretory antibody-mediated immune exclusion of microbial components. [source] Role for CTLA-4 but not CD25+ T cells during Schistosoma mansoni infection of micePARASITE IMMUNOLOGY, Issue 6 2007C. M. WALSH SUMMARY Schistosoma mansoni infection of mice increases the frequency of cells that are CD4+CD25+ in the acute (4 and 8 weeks) and chronic (16 week) stages of infection. Depletion of > 85% of CD25+ cells in the acute or chronic stages of schistosome infection caused no overt changes in morbidity or immunological responses. The absence of effect in mice with CD25+ cells depleted may be due to the preferential expression of IL-4 and IL-10, two cytokines that are protective in schistosome infection, on CD25, CD4+ cells. We also assessed infection-induced changes of other regulatory markers, GITR, CD103 and CTLA-4 on CD4+ cells. We identified a marked expansion of CTLA-4+ population on CD25, CD4+ cells in acute and chronic infection. Blocking of CTLA-4 during acute, but not chronic infection, caused significant weight loss and altered the type 2 cytokine response of mice, with increased IL-4 and IL-5 production associated with significantly more Th2 cells and eosinophils in the liver granuloma. This study illustrates the complexity of regulation of T cells in schistosome infection and highlights a specific role for CTLA-4+, but not CD25+ cells, in the regulation of Th2 responses in helminth infection. [source] Induction of IL-10+ CD4+ CD25+ regulatory T cells with decreased NF-,B expression during immunotherapyPEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 1-Part-II 2010Yi-Giien Tsai Tsai Y-G, Chiou Y-L, Chien J-W, Wu H-P, Lin C-Y. Induction of IL-10+ CD4+ CD25+ regulatory T cells with decreased NF-,B expression during immunotherapy. Pediatr Allergy Immunol 2010: 21: e166,e173. © 2009 The Authors Journal compilation © 2009 Blackwell Munksgaard MyD88 is a major toll-like receptor (TLR) adaptor to activate NF-,B, which acts as a mater switch for allergic inflammation disease. Sterile hust dust extracts have been reported with TLR-dependent immunostimulatory activities. The aim of this study was to evaluate whether Dermatophagoides pteronyssinus (Der p) immunotherapy may increase IL-10+ CD4+ CD25+ T cells with modulating MyD88 signaling proteins, to decrease NF-,B expression. Peripheral blood mononuclear cells were isolated from patients before and after 1 yr of Der p immunotherapy, and also from matched control subjects. After 2 days of Der p-2 stimulation, intracellular IL-10 and Foxp3 expression of CD4+ CD25+ T cells were measured by flow-cytometry. The expression of IL-1 receptor-associated kinase (IRAK)-1 in cytoplasm and IFN-regulator factor-3 (IRF-3) with NF-,B/p65 in nuclei was determined by Western-blot analysis. Patients undergoing immunotherapy produced more soluble CD14, IL-10, and TGF-, that correlated with FEV1improvement (p < 0.05). In the immunotherapy group, the number of Foxp3+ CD4+ Treg cells increased more than the baseline status (25.06 ± 4.19 vs. 16.08 ± 3.54, p < 0.05). Additionally, increased IL-10 production with decreased IRAK-1 and NF-,B/p65 nuclear translocation was observed in sorted-purified Treg cells. IL-10+ CD4+ CD25+ Treg cells may respond to Der p-2 and down-regulate NF-,B/p65 expression to maintain immune tolerance during immunotherapy. [source] Proinflammatory mediator,induced reversal of CD4+,CD25+ regulatory T cell,mediated suppression in rheumatoid arthritisARTHRITIS & RHEUMATISM, Issue 3 2007Jocea M. R. van Amelsfort Objective We previously demonstrated that CD4+,CD25+ regulatory T (Treg) cells are present in increased numbers in the synovial fluid (SF) of rheumatoid arthritis (RA) patients and display enhanced suppressive activity as compared with their peripheral blood (PB) counterparts. Despite the presence of these immunoregulatory cells in RA, chronic inflammation persists. The purpose of the present study was to investigate whether particular proinflammatory mediators that are associated with RA could abrogate CD4+,CD25+ Treg,mediated suppression. Methods Monocyte phenotype was determined by flow cytometry and cytokine levels by enzyme-linked immunosorbent assay. Magnetically sorted CD4+,CD25, and CD4+,CD25+ T cells derived from the PB and SF obtained from RA patients were stimulated alone or in coculture with anti-CD3 monoclonal antibody (mAb) and autologous antigen-presenting cells, in the absence or presence of anti-CD28 mAb or the proinflammatory cytokines interleukin-6 (IL-6), tumor necrosis factor , (TNF,), or IL-7. Results Monocytes from the SF of RA patients displayed increased expression of HLA class II molecules, CD80, CD86, and CD40 as compared with PB-derived monocytes, indicating their activated status. Mimicking this increased costimulatory potential, addition of anti-CD28 mAb to cocultures of CD4+,CD25, and CD4+,CD25+ T cells resulted in reduced CD4+,CD25+ Treg,mediated suppression in both PB and SF. Furthermore, IL-7 and, to a limited extent, TNF,, both of which are produced by activated monocytes and were detected in SF, abrogated the CD4+,CD25+ Treg,mediated suppression. In contrast, IL-6 did not influence Treg-mediated suppression. Conclusion Our findings suggest that the interaction of CD4+,CD25+ Treg cells with activated monocytes in the joint might lead to diminished suppressive activity of CD4+,CD25+ Treg cells in vivo, thus contributing to the chronic inflammation in RA. [source] Seasonal changes in suppressive capacity of CD4+ CD25+ T cells from patients with hayfever are allergen-specific and may result in part from expansion of effector T cells among the CD25+ populationCLINICAL & EXPERIMENTAL ALLERGY, Issue 11 2009A. E. Anderson Summary Background Suppression of allergen-stimulated peripheral blood CD4+ CD25, effector T cells by CD4+ CD25+ regulatory T cells obtained from subjects with allergic rhinoconjunctivitis is reduced during the pollen season when compared with out of season. Objective We examined possible explanations for this effect of seasonal pollen exposure on suppression of allergen responses. Methods CD4+ CD25, and CD4+ CD25+ T cells were isolated from blood obtained from 44 volunteers with allergic rhinoconjunctivitis during and out of the UK grass pollen season. Co-cultures were performed with grass pollen extract and house dust mite (HDM) to examine allergen specificity. The frequency of IL-5 and IL-10 producing cells was determined by ELISPOT and the expression of T cell activation markers and the CD25+ regulatory T cell-associated transcription factor Foxp3 were examined. Lactic acid stripping of IgE was used to determine IgE dependence of T cell responses. Results The seasonal reduction in suppression by CD4+ CD25+ T cells was confirmed and was shown to be allergen specific because suppression of HDM-stimulated cultures was not affected significantly. The CD4+ CD25+ population contained IL-5 and IL-10 producing cells but increases in their frequencies with seasonal pollen exposure were not significant. Both activation marker and Foxp3 expression increased during the pollen season. IgE stripping reduced CD4+ and CD4+ CD25, T cell responses to allergen, but had no effect on suppression by CD4+ CD25+ T cells. Conclusion The seasonal reduction in suppression of grass pollen-stimulated effector T cells by CD4+ CD25+ T cells is allergen specific and cannot be explained by increased IgE-facilitated allergen presentation. We suggest that changes in the proportion of effector to regulatory T cells among the CD25+ population isolated may partially explain these findings, and that trafficking to the site of allergic disease may reduce allergen-specific regulatory T cell numbers in peripheral blood. [source] Frequencies and role of regulatory T cells in patients with (pre)malignant cervical neoplasiaCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 2 2007J. Visser Summary Oncogenic human papillomavirus (HPV)-infection is crucial for developing cervical cancer and its precursor lesions [cervical intraepithelial neoplasia (CIN)]. Regulatory T cells (Tregs) might be involved in the failure of the immune system to control the development of HPV-induced cancer. We investigated frequencies, phenotype and activity of Tregs in patients with cervical neoplasia. CIN and cervical cancer patients showed increased CD4+/CD25high T cell frequencies in peripheral blood and CD4+ T cell fraction. These CD4+/CD25high T cells represent Tregs as demonstrated by their low proliferation rate, low interferon (IFN)-,/interleukin (IL)-10 ratio, high expression of CD45RO, GITR, CTLA-4, forkhead box P3 (FoxP3) and low CD45RA expression. Moreover, in HPV16+ cervical cancer patients, in-vitro depletion of CD25+ T cells resulted in increased IFN-, T cell responses against HPV16 E6- and E7 peptides. Thus, increased frequencies of Tregs in cervical cancer patients may indeed suppress HPV-specific immunity. Longitudinal analysis of CD4+/CD25high T cell frequencies in patients showed a modest decline 1 year after curative surgery or chemoradiation. This study demonstrates increased frequencies and suppressive activity of Tregs in cervical cancer. These results imply that Tregs may suppress the immune control of cervical neoplasia and furthermore that suppression of immunity by Tregs will be another hurdle to overcome in therapeutic immunization strategies against cervical neoplasia. [source] CD4+ CD25+ transforming growth factor-,-producing T cells are present in the lung in murine tuberculosis and may regulate the host inflammatory response,CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2007C. M. Mason Summary CD4+ CD25+ regulatory T cells produce the anti-inflammatory cytokines transforming growth factor (TGF)-, or interleukin (IL)-10. Regulatory T cells have been recognized to suppress autoimmunity and promote self-tolerance. These cells may also facilitate pathogen persistence by down-regulating the host defence response during infection with Mycobacterium tuberculosis. We evaluated TGF-,+ and IL-10+ lung CD4+ CD25+ T cells in a murine model of M. tuberculosis. BALB/c mice were infected with ,50 colony-forming units of M. tuberculosis H37Rv intratracheally. At serial times post-infection, lung cells were analysed for surface marker expression (CD3, CD4, CD25) and intracellular IL-10, TGF-,, and interferon (IFN)-, production (following stimulation in vitro with anti-CD3 and anti-CD28 antibodies). CD4+ lung lymphocytes were also selected positively after lung digestion, and stimulated in vitro for 48 h with anti-CD3 and anti-CD28 antibodies in the absence and presence of anti-TGF-, antibody, anti-IL-10 antibody or rmTGF-, soluble receptor II/human Fc chimera (TGF,srII). Supernatants were assayed for elicited IFN-, and IL-2. Fluorescence activated cell sorter analyses showed that TGF-,- and IL-10-producing CD4+ CD25+ T cells are present in the lungs of infected mice. Neutralization of TGF-, and IL-10 each resulted in increases in elicited IFN-,, with the greatest effect seen when TGF,srII was used. Elicited IL-2 was not affected significantly by TGF-, neutralization. These results confirm the presence of CD4+ CD25+ TGF-,+ T cells in murine pulmonary tuberculosis, and support the possibility that TGF-, may contribute to down-regulation of the host response. [source] The number of human peripheral blood CD4+ CD25high regulatory T cells increases with ageCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2005R. Gregg Summary Ageing is associated with evidence of immune deficiency and dysregulation. Key changes in the immune system with ageing include a progressive reduction in naive T cell output associated with thymic involution and peripheral expansion of oligoclonal memory T cells. These features are associated with evidence of impaired immune responsiveness both in vitro and in vivo, termed immune senescence. CD4+ CD25+ T cells have recently been recognized as mediators of peripheral immune regulation and play a role in the control of autoimmune and pathogen-specific immune responses. The significance of CD4+ CD25+ regulatory T cells in the context of immunosenescence is not known. We have investigated the number, phenotype and function of CD4+ CD25+ T cells in healthy volunteers over a wide age range. We demonstrate that the number of CD4+ CD25+ and CD4+ CD25high T cells in healthy volunteers increases with age. In both age groups CD4+ CD25+ T cells showed a phenotype consistent with that described for regulatory T cells. Further analysis of CD4+ CD25high T cells in young and elderly donors showed equivalent expression of intracellular CTLA-4 and surface expression of activation markers. In vitro, functional titration assays of CD4+ CD25high T cells demonstrated equivalent regulatory function in both young and elderly donors, with suppression of proliferation and cytokine production in response to polyclonal T cell stimulation. These observations demonstrate an increase in peripheral blood CD4+ CD25high regulatory T cells associated with ageing. The relevance of these expanded cells in relation to the immune senescence seen in the elderly as yet remains unclear. [source] Idiotype-specific CD4+CD25+ T suppressor cells prevent, by limiting antibody diversity, the occurrence of anti-dextran antibodies crossreacting with histone H3EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 5 2003Christoph Specht Abstract CD25+ suppressor T cells regulate the immune response against the type-2 "thymus independent" bacterial polysaccharide antigen ,(1,3)dextran (Dex) in BALB/c mice. These T cells, represented by the clone 178-4 Ts, restrict the Dex-specific IgG antibody repertoire such that the J558 idiotype dominates. Antibodies with other structures in the heavy-chain variable region (VH region), predominantly within the CDR3 domain, occur when the T cell control fails. This increase of antibody diversity caused by a lack of CD25+ Ts cells, e.g. in nude mice, does not result in the appearance of antibodies with enhanced affinity to the antigen Dex, but often leads to a crossreactivity with autologous proteins. Twenty-two out of sixty Dex-specific hybridomas from nude mice, but no hybridomas from euthymic mice, crossreact with a nuclear protein, as tested by ELISA. This nuclear protein was identified as histone H3. Ten of the sixty hybridomas from nude mice were sequenced and show VH sequences that deviate from the original J558 sequence. Three of these ten hybridomas crossreact with the histone H3. Adoptive transfer of CD25+ Ts cells to nude mice leads to a marked increase of antibodies carrying the original J558 idiotype within the IgG pool after immunization with Dex. Our data demonstrate a CD25+ Ts cell-mediated restriction of VH usage, which prevents the appearance of crossreactive autoantibodies. [source] | ||||||||||||||||||||||