51
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Brossard C, Semichon M, Trautmann A, Bismuth G. CD5 inhibits signaling at the immunological synapse without impairing its formation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:4623-9. [PMID: 12707340 DOI: 10.4049/jimmunol.170.9.4623] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Physiologically, Ag detection by T cells occurs at the immunological synapse (IS) formed at the interface with an APC. CD5 is considered as an inhibitory molecule for Ag receptor-mediated signals in T cells. However, the influence of CD5 at the IS on synapse formation and functioning has not yet been reported. We demonstrate here that CD5 is recruited and tightly colocalized with CD3 in different human and murine IS. Following transfection in a CD5-negative T cell line of CD5 fused to the green fluorescent protein, we show that CD5 recruitment includes a fast Ag-independent and a slower Ag-dependent component. In video-imaging recordings of doubly transfected cells, the movements of CD3 and CD5 show similar kinetics, and the amount of CD3 recruited to the synapse is unaffected by CD5 expression. Moreover, APC-T cell adhesion is unchanged in CD5-expressing cells. Despite this, the extent of tyrosine phosphorylation at the synapse and the amplitude of calcium responses induced by Ag recognition are both decreased by CD5. These inhibitions increase with CD5 membrane levels. They also requires the pseudo-immunoreceptor tyrosine-based activation motif expressed in the cytoplasmic domain of the molecule. Thus, CD5 is rapidly recruited at the IS and lowers the T cell response elicited by Ag presentation by targeting downstream signaling events without affecting IS formation.
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Affiliation(s)
- Cédric Brossard
- Département de Biologie Cellulaire, Institut National de la Santé et de la Recherche Médicale, Unité 567, Center National de la Recherche Scientifique, Unité Mixte de Recherche 8104, Université René Descartes, Institut Cochin, Paris, France
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52
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Abstract
The CD5 coreceptor is a cysteine-rich scavenger receptor family glycoprotein that is expressed constitutively on all T cells and a subset of B cells (B I a B cells). It is now generally accepted that the biologic role of CD5 is to regulate intracellular strength induced by antigen receptors in both T and B cells. However, at present it is unclear if this coreceptor's effect on antigen receptor signaling is primarily costimulatory or inhibitory since support for both exists. Our studies focus on understanding the physiologic role of CD5 in the context of regulation of antigen receptor activation, B and T cell selection, and generation/maintenance of immune tolerance. In this overview, I discuss studies using experimental models of lymphocyte selection and tolerance showing that CD5 plays a key role in B and T cell selection as well as generation and maintenance of tolerance. I and others, reviewed here, now provide clear evidence that CD5 is a key regulator of immune tolerance and that alterations of its activity can promote development of autoreactivity.
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Affiliation(s)
- Chander Raman
- Department of Medicine, University of Alabama at Birmingham, 35294-0007, USA.
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53
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Chen W, Ford MS, Young KJ, Cybulsky MI, Zhang L. Role of double-negative regulatory T cells in long-term cardiac xenograft survival. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:1846-53. [PMID: 12574350 DOI: 10.4049/jimmunol.170.4.1846] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A novel subset of CD3(+)CD4(-)CD8(-) (double negative; DN) regulatory T cells has recently been shown to induce donor-specific skin allograft acceptance following donor lymphocyte infusion (DLI). In this study, we investigated the effect of DLI on rat to mouse cardiac xenotransplant survival and the ability of DN T cells to regulate xenoreactive T cells. B6 mice were given either DLI from Lewis rats, a short course of depleting anti-CD4 mAb, both DLI and anti-CD4 treatment together, or left untreated. DLI alone did not prolong graft survival when compared with untreated controls. Although anti-CD4-depleting mAb alone significantly prolonged graft survival, grafts were eventually rejected by all recipients. However, the combination of DLI and anti-CD4 treatment induced permanent cardiac xenograft survival. We demonstrate that recipients given both DLI and anti-CD4 treatment had a significant increase in the total number of DN T cells in their spleens when compared with all other treatment groups. Furthermore, DN T cells harvested from the spleens of DLI plus anti-CD4-treated mice could dose-dependently inhibit the proliferation of syngeneic antidonor T cells. Suppression mediated by these DN T cells was specific for antidonor T cells as T cells stimulated by third-party Ags were not suppressed. These results demonstrate for the first time that a combination of pretransplant DLI and anti-CD4-depleting mAb can induce permanent survival of rat to mouse cardiac xenografts and that DN T regulatory cells play an important role in preventing long-term concordant xenograft rejection through the specific suppression of antidonor T cells.
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MESH Headings
- Adoptive Transfer
- Animals
- Antibodies, Monoclonal/administration & dosage
- Antigens/metabolism
- Antigens, Surface
- CD3 Complex/biosynthesis
- CD4 Antigens/immunology
- CD4 Antigens/metabolism
- CD4-Positive T-Lymphocytes/immunology
- CD8 Antigens/metabolism
- CD8-Positive T-Lymphocytes/immunology
- Cell Division/genetics
- Cell Division/immunology
- Epitopes, T-Lymphocyte/immunology
- Graft Enhancement, Immunologic/methods
- Graft Survival/genetics
- Graft Survival/immunology
- Heart Transplantation/immunology
- Immune Tolerance/genetics
- Immunosuppression Therapy
- Injections, Intraperitoneal
- Interphase/immunology
- Lectins, C-Type
- Lymphocyte Activation/genetics
- Lymphocyte Activation/immunology
- Lymphocyte Transfusion
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- NK Cell Lectin-Like Receptor Subfamily B
- Proteins/metabolism
- Rats
- Rats, Inbred Lew
- Rats, Inbred WF
- Spleen/cytology
- Spleen/metabolism
- Spleen/transplantation
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
- Transplantation Conditioning
- Transplantation, Heterologous/immunology
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Affiliation(s)
- Wenhao Chen
- Department of Laboratory Medicine and Pathobiology, Multi Organ Transplantation Program, Toronto General Research Institute, University Health Network, University of Toronto, Toronto, Ontario, M5G 2C4 Canada
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54
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Abstract
Host defense against pathogenic microbes requires dramatically different responses, depending on the character of the pathogen and on the tissue under attack. Central to the immune system's ability to mobilize a response to an invading pathogen is its ability to distinguish self from nonself. The host has evolved both innate and adaptive mechanisms to respond to and eliminate pathogenic microbes. Both of these mechanisms include self-nonself discrimination. This overview describes key mechanisms used by the immune system to respond to invading microbes and identifies settings in which disturbed immune function exacerbates tissue injury.
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Affiliation(s)
- David D Chaplin
- University of Alabama at Birmingham, 845 19th Street South, BBRB 276/11, Birmingham, AL 35294-2170, USA
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55
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Cho HJ, Edmondson SG, Miller AD, Sellars M, Alexander ST, Somersan S, Punt JA. Cutting edge: identification of the targets of clonal deletion in an unmanipulated thymus. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:10-3. [PMID: 12496375 DOI: 10.4049/jimmunol.170.1.10] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Autoreactive thymocytes can be eliminated by clonal deletion during their development in the thymus. The precise developmental stage(s) at which clonal deletion occurs in a normal thymus has been difficult to assess, in large part because of the absence of a specific marker for TCR-mediated apoptosis. In this report, we reveal that Nur77 expression can be used as a specific marker of clonal deletion in an unmanipulated thymus and directly identify TCRintCD4+CD8+ and semimature CD4+CD8- thymocytes as the principal targets of deletion. These data indicate that clonal deletion normally occurs at a relatively late stage of development, as cells mature from CD4+CD8+ thymocytes to single-positive T cells.
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Affiliation(s)
- Hyung J Cho
- Department of Biology, Haverford College, Haverford, PA 19041, USA
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56
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Purton J, Zhan Y, Liddicoat D, Hardy C, Lew AM, Cole T, Godfrey D. Glucocorticoid receptor deficient thymic and peripheral T cells develop normally in adult mice. Eur J Immunol 2002. [DOI: 10.1002/1521-4141(200212)32:12%3c3546::aid-immu3546%3e3.0.co;2-s] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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57
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Purton JF, Zhan Y, Liddicoat DR, Hardy CL, Lew AM, Cole TJ, Godfrey DI. Glucocorticoid receptor deficient thymic and peripheral T cells develop normally in adult mice. Eur J Immunol 2002; 32:3546-55. [PMID: 12442337 DOI: 10.1002/1521-4141(200212)32:12<3546::aid-immu3546>3.0.co;2-s] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The involvement of glucocorticoid receptor (GR) signaling in T cell development is highly controversial, with several studies for and against. We have previously demonstrated that GR(-/-) mice, which usually die at birth because of impaired lung development, exhibit normal T cell development, at least in embryonic mice and in fetal thymus organ cultures. To directly investigate the role of GR signaling in adult T cell development, we analyzed the few GR(-/-) mice that occasionally survive birth, and irradiated mice reconstituted with GR(-/-) fetal liver precursors. All thymic and peripheral T cells, as well as other leukocyte lineages, developed and were maintained at normal levels. Anti-CD3-induced cell death of thymocytes in vitro, T cell repertoire heterogeneity and T cell proliferation in response to anti-CD3 stimulation were normal in the absence of GR signaling. Finally, we show that metyrapone, an inhibitor of glucocorticoid synthesis (commonly used to demonstrate a role for glucocorticoids in T cell development), impaired thymocyte development regardless of GR genotype indicating that this reagent inhibits thymocyte development in a glucocorticoid-independent fashion. These data demonstrate that GR signaling is not required for either normal T cell development or peripheral maintenance in embryonic or adult mice.
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Affiliation(s)
- Jared F Purton
- Monash University Medical School, Department of Pathology and Immunology, Victoria, Australia
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58
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Daniels MA, Hogquist KA, Jameson SC. Sweet 'n' sour: the impact of differential glycosylation on T cell responses. Nat Immunol 2002; 3:903-10. [PMID: 12352967 DOI: 10.1038/ni1002-903] [Citation(s) in RCA: 206] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The fate and functional activity of T lymphocytes depend largely on the precise timing of gene expression and protein production. However, it is clear that post-translational modification of proteins affects their functional properties. Although modifications such as phosphorylation have been intensely studied by immunologists, less attention has been paid to the impact that changes in glycosylation have on protein function. However, there is considerable evidence that glycosylation plays a key role in immune regulation. We will focus here on examples in which differential glycosylation affects the development, survival or reactivity of T cells.
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Affiliation(s)
- Mark A Daniels
- Center for Immunology and Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN 55455, USA
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59
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He Y. Orphan nuclear receptors in T lymphocyte development. J Leukoc Biol 2002. [DOI: 10.1189/jlb.72.3.440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- You‐Wen He
- Department of Immunology, Duke University Medical Center, Durham, North Carolina
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60
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Matsuki Y, Zhang HG, Hsu HC, Yang PA, Zhou T, Dodd CH, Cecconi F, Gruss P, Tadakuma T, Mountz JD. Different role of Apaf-1 in positive selection, negative selection and death by neglect in foetal thymic organ culture. Scand J Immunol 2002; 56:174-84. [PMID: 12121437 DOI: 10.1046/j.1365-3083.2002.01120.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Apoptotic protease-activating factor 1 (Apaf-1) is a component of the apoptosome which is required for the activation of procaspase-9. As Apaf-1 knockout (KO) (Apaf-1-/-) mice die before birth, the role of Apaf-1 during thymic selection was investigated using 5 day foetal thymic organ culture (FTOC) of thymi obtained at gestational day 15. There was a lower ratio of CD4 single-positive (SP) to CD8 SP cells and decreased apoptosis of CD4+CD8+ (DP) thymocytes from Apaf-1-/- mice compared with wild-type. To determine if these defects resulted in increased production of neglected thymocytes, the Apaf-1-/- mice were crossed with the T-cell receptor (TCR)-alpha-chain KO mice. There was no difference in thymocyte development in the thymi of TCR-alpha-/-Apaf-1-/- and TCR-alpha-/-Apaf-1+/+ mice 5 days after FTOC. To determine if Apaf-1 is involved in apoptosis during death by negative or positive selection, FTOC of the thymus of Apaf-1-/- Db/HY TCR-alphabeta transgenic (Tg) mice was carried out. There was decreased apoptosis of the HY clonal-specific M33+ thymocytes and an increased percentage of the autoreactive CD8+M33+ thymocytes in male, but not female Apaf-1-/- Db/HY TCR Tg mice. Our data suggest that Apaf-1 is not involved in positive selection or death by neglect, but may have a partial role in negative selection during early thymic T-cell development.
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Affiliation(s)
- Y Matsuki
- Department of Immulogy and Parasitology, National Defense Medical College, Saitama, Japan
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61
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Ford MS, Young KJ, Zhang Z, Ohashi PS, Zhang L. The immune regulatory function of lymphoproliferative double negative T cells in vitro and in vivo. J Exp Med 2002; 196:261-7. [PMID: 12119351 PMCID: PMC2193928 DOI: 10.1084/jem.20020029] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Lymphoproliferative (lpr) mice, which lack functional Fas receptor expression and develop autoimmune lymphoproliferative disease, have an accumulation of T cell receptor-alphabeta(+)CD4(-)CD8(-) (double negative T cells [DNTC]) in the periphery. The function of the accumulating DNTC is not clear. In this study we demonstrate that B6/lpr DNTC can dose dependently kill syngeneic CD8(+) and CD4(+) T cells from wild-type B6 mice through Fas/Fas ligand interactions in vitro. We also demonstrate that B6/lpr DNTC that are activated and expand in vivo are able to specifically down-regulate allogeneic immune responses mediated by syngeneic Fas(+)CD4(+) and CD8(+) T cells in vivo. B6/lpr DNTC that have been preactivated in vivo by infusion of either class I- (bm1) or class II- (bm12) mismatched allogeneic lymphocytes are able to specifically enhance the survival of bm1 or bm12, but not third-party skin allografts when adoptively transferred into naive B6(+/+) mice. These findings clearly demonstrate that B6/lpr DNTC have a potent immune regulatory function in vitro and in vivo. They also provide new insights into the mechanisms involved in the development of autoimmune disease in lpr mice.
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Affiliation(s)
- Megan S Ford
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Multi Organ Transplantation Program, Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario M5G 2C4, Canada
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62
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Abstract
Maintenance of tolerance to self antigens is presumed to reflect a combination of central and peripheral tolerance. For T cells, central tolerance occurs during early T cell development in the thymus and causes cells with strong reactivity to self antigens to be destroyed in situ (negative selection). Here, we summarize evidence that negative selection can occur in the thymic medulla and affects a population of semimature HSA+ T cells. The influence of costimulatory molecules, Fas and cytokines on negative selection is discussed.
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Affiliation(s)
- Jonathan Sprent
- Department of Immunology, IMM4, The Scripps Research Institute, La Jolla, California 92037, USA.
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63
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Abstract
Whether B-1a (CD5+) cells are a distinct lineage derived from committed fetal/neonatal precursors or arise from follicular B-2 cells in response to BCR ligation and other, unknown signals remains controversial. Recent evidence indicates that B-1a cells can derive from adult precursors expressing an appropriate specificity when the (self-) antigen is present. Antibody specificity determines whether a B cell expressing immunoglobulin transgenes has a B-2, B-1a or marginal zone (MZ) phenotype. MZ cells share many phenotypic characteristics of B-1 cells and, like them, appear to develop in response to T independent type 2 antigens. Because fetal-derived B cell progenitors fail to express terminal deoxynucleotidyl transferase (TdT) and for other reasons, they are likely to express a repertoire that allows selection into the B-1a population. As it is selected by self-antigen, the B-1 repertoire tends to be autoreactive. This potentially dangerous repertoire is also useful, as B-1 cells are essential for resistance to several pathogens and they play an important role in mucosal immunity. The CD5 molecule can function as a negative regulator of BCR signaling that may help prevent inappropriate activation of autoreactive B-1a cells.
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Affiliation(s)
- Robert Berland
- Department of Pathology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA.
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64
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Lu X, Axtell RC, Collawn JF, Gibson A, Justement LB, Raman C. AP2 adaptor complex-dependent internalization of CD5: differential regulation in T and B cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 168:5612-20. [PMID: 12023358 DOI: 10.4049/jimmunol.168.11.5612] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
CD5 is a key regulator of Ag receptor-mediated activation, selection, and differentiation in both T and B cells. Accumulating evidence indicates that lymphocyte activation and selection are sensitive to variations in levels of CD5 on the cell surface. We now show that CD5 expression on the surface of B and T cells is regulated posttranslationally by direct interaction with the mu(2) subunit of the AP2 adaptor complex that links transmembrane proteins to clathrin-coated pits. CD5 is rapidly internalized from the cell surface in lymphoid cell lines, mature splenic T and B cells, and peritoneal CD5(+) B cells following monovalent or bivalent ligation of the receptor. We mapped the mu(2) subunit binding site on CD5 to Y(429) and determined that the integrity of this site was necessary for CD5 internalization. Cross-linking of the Ag receptor with intact Abs inhibited CD5 internalization in B cells, but had the opposite effect in T cells. However, if F(ab')(2) Abs were used to stimulate the Ag receptor in B cells, the effect on CD5 internalization was now similar to that observed in T cells, indicating that signals through the Ag receptor and FcR regulate CD5 endocytosis in B cells. This was confirmed using an FcgammaRIIB1-deficient B cell line. The ability to differentially alter posttranslational CD5 expression in T and B cells is likely to be key in regulation of Ag receptor signaling and generation of tolerance in T and B lymphocytes.
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Affiliation(s)
- Xianghuai Lu
- Division of Clinical Immunology and Rheumatology, Departments of Medicine, Cell Biology, and Microbiology, University of Alabama, Birmingham, AL 35294
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65
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Gao JX, Zhang H, Bai XF, Wen J, Zheng X, Liu J, Zheng P, Liu Y. Perinatal blockade of b7-1 and b7-2 inhibits clonal deletion of highly pathogenic autoreactive T cells. J Exp Med 2002; 195:959-71. [PMID: 11956287 PMCID: PMC2193695 DOI: 10.1084/jem.20011948] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
A number of in vitro studies have suggested that costimulatory molecules B7-1 and B7-2 and their receptor CD28 can promote clonal deletion, and limited in vivo studies have indicated that CD28 is involved in the clonal deletion of some T cells. However, the significance of B7-mediated clonal deletion in preventing autoimmune diseases has not been studied systematically. Here we report that the perinatal blockade of B7-1 and B7-2 substantially inhibits the clonal deletion of T cells in the thymus and leads to an accumulation of T cells capable of inducing fatal multiorgan inflammation. These results reveal a critical role for costimulatory molecules B7-1 and B7-2 in deleting pathogenic autoreactive T cells in the thymus. The critical role of B7-1 and B7-2 in T cell clonal deletion may explain, at least in part, the paradoxical increase of autoimmune disease in mice deficient for this family of costimulatory molecules, such as cytotoxic T lymphocyte associated molecule 4, CD28, and B7-2. The strong pathogenicity of the self-reactive T cells supports a central hypothesis in immunology, which is that clonal deletion plays an important role in preventing autoimmune diseases.
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Affiliation(s)
- Jian-Xin Gao
- Department of Pathology and Comprehensive Cancer Center, Division of Cancer Immunology, Ohio State University Medical Center, Columbus, OH 43210, USA
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66
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McNeil LK, Evavold BD. Dissociation of peripheral T cell responses from thymocyte negative selection by weak agonists supports a spare receptor model of T cell activation. Proc Natl Acad Sci U S A 2002; 99:4520-5. [PMID: 11904393 PMCID: PMC123680 DOI: 10.1073/pnas.072673899] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
We have focused on stability of the peptide-MHC complex as a determining factor of ligand potency for thymocytes and peripheral CD4+ T cell responses. MHC variant peptides that have low affinities and fast dissociation rates are different in that they stimulate proliferation and cytolysis of mature T cells (classifying the variant peptides as weak agonists) but do not induce thymocyte negative selection. The MHC variant weak agonists require significant receptor reserve, because decreasing the level of T cell receptor on mature T cells blocks the proliferative response. These results demonstrate that peripheral T cells are more sensitive to MHC variant ligands by virtue of increased T cell receptor expression; in addition, the data support a T cell model of the spare receptor theory.
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Affiliation(s)
- Lisa K McNeil
- Department of Microbiology and Immunology, Emory University, Atlanta, GA 30322, USA
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67
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Abstract
Among the numerous steroid and orphan nuclear receptors encoded within mammalian genomes, several are involved in regulating immune system functions. We review here recent studies on the glucocorticoid receptor and the orphan receptors Nur77 and RORgamma. These molecules play key roles in the development and the effector functions of T lymphocytes.
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Affiliation(s)
- Astar Winoto
- Department of Molecular and Cell Biology, 469 LSA, University of California, Berkeley, Berkeley, CA 94720, USA.
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68
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Williams JA, Sharrow SO, Adams AJ, Hodes RJ. CD40 ligand functions non-cell autonomously to promote deletion of self-reactive thymocytes. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 168:2759-65. [PMID: 11884443 DOI: 10.4049/jimmunol.168.6.2759] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
CD40 ligand (CD40L)-deficient mice have been shown to have a defect in negative selection of self-reactive T cells during thymic development. However, the mechanism by which CD40L promotes deletion of autoreactive thymocytes has not yet been elucidated. We have studied negative selection in response to endogenous superantigens in CD40L-deficient mice and, consistent with previous reports, have found a defect in negative selection in these mice. To test the requirement for expression of CD40L on T cells undergoing negative selection, we have generated chimeric mice in which CD40L wild-type and CD40L-deficient thymocytes coexist. We find that both CD40L wild-type and CD40L-deficient thymocytes undergo equivalent and efficient negative selection when these populations coexist in chimeric mice. These results indicate that CD40L can function in a non-cell-autonomous manner during negative selection. Deletion of superantigen-reactive thymocytes was normal in B7-1/B7-2 double-knockout mice, indicating that CD40-CD40L-dependent negative selection is not solely mediated by B7 up-regulation and facilitation of B7-dependent T cell signaling. Finally, although the absence of CD40-CD40L interactions impairs negative selection of autoreactive CD4(+) and CD8(+) cells during thymic development, we find that self-reactive T cells are deleted in the mature CD4(+) population through a CD40L-independent pathway.
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Affiliation(s)
- Joy A Williams
- Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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69
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Wang R, Wang-Zhu Y, Grey H. Interactions between double positive thymocytes and high affinity ligands presented by cortical epithelial cells generate double negative thymocytes with T cell regulatory activity. Proc Natl Acad Sci U S A 2002; 99:2181-6. [PMID: 11842216 PMCID: PMC122339 DOI: 10.1073/pnas.042692799] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Previous studies on thymocyte differentiation by using reaggregate cultures (RC) of double positive T cell receptor (TCR) transgenic thymocytes and the thymic epithelial cell line ANV indicated that low concentrations of high affinity ligands for the TCR were efficient inducers of thymocyte maturation to CD4 single positive (SP) functional cells. In this study, it is demonstrated that, when high concentrations of high affinity ligands are used in this RC system, double positive (DP) cells down-modulate expression of both coreceptors and that, as a result, large numbers of double negative (DN) cells are generated. These DN cells proliferated modestly in response to stimulation by antigen, and this response was considerably augmented by the addition of IL-2 to the cultures. Notably, these antigen-stimulated DN cells produced large amounts of IL-10. When the DN cells generated in RC were cocultured with naive TCR transgenic T cells in the presence of antigen, they suppressed the proliferative response of the naive T cells. Thus, high affinity ligands, when presented to DP thymocytes by cortical thymic epithelial cells in reaggregate cultures, rather than causing deletion of the immature thymocytes, induce their differentiation into immunoregulatory DN cells, suggesting a distinct mechanism by which self tolerance may be maintained.
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Affiliation(s)
- Rongfang Wang
- La Jolla Institute for Allergy and Immunology, 10355 Science Center Drive, San Diego, CA 92121, USA
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70
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Abstract
The predisposition of nonobese diabetic (NOD) mice to develop autoimmune disease is usually attributed to defects in peripheral tolerance mechanisms. Here, evidence is presented that NOD mice display a defect in central tolerance (negative selection) of thymocytes. Impaired central tolerance in NOD mice was most prominent in a population of semi-mature thymocytes found in the medulla. The defect was apparent in vivo as well as in vitro, was independent of IAbetag7 expression and affected both Fas-dependent and Fas-independent pathways of apoptosis; for Fas-dependent apoptosis, the defective tolerance of NOD thymocytes correlated with the strong T cell receptor-mediated up-regulation of caspase 8-homologous FLICE (Fas-associated death-domain-like interleukin 1beta-converting enzyme)-inhibitory protein. In light of these findings, disease onset in NOD mice may reflect defects in central as well as peripheral tolerance.
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MESH Headings
- Animals
- Antigens, CD/biosynthesis
- Antigens, CD/genetics
- Antigens, Differentiation, T-Lymphocyte/biosynthesis
- Antigens, Differentiation, T-Lymphocyte/genetics
- Apoptosis
- Autoimmune Diseases/genetics
- Autoimmune Diseases/immunology
- CASP8 and FADD-Like Apoptosis Regulating Protein
- CD28 Antigens/physiology
- CD4 Antigens/analysis
- CD8 Antigens/analysis
- Carrier Proteins/biosynthesis
- Carrier Proteins/genetics
- Clonal Deletion/immunology
- Diabetes Mellitus, Type 1/genetics
- Diabetes Mellitus, Type 1/immunology
- Fas Ligand Protein
- Gene Expression Regulation
- Genetic Predisposition to Disease
- Immune Tolerance/immunology
- Interleukin-4/pharmacology
- Interleukin-7/pharmacology
- Intracellular Signaling Peptides and Proteins
- Lectins, C-Type
- Membrane Glycoproteins/physiology
- Mice
- Mice, Inbred C57BL
- Mice, Inbred MRL lpr
- Mice, Inbred NOD/genetics
- Mice, Inbred NOD/immunology
- Mice, Inbred NZB
- RNA, Messenger/biosynthesis
- Receptors, Antigen, T-Cell/physiology
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/pathology
- Thymus Gland/pathology
- fas Receptor/physiology
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Affiliation(s)
- H Kishimoto
- Department of Immunology, IMM4, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA
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71
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Gomez M, Kioussis D, Cantrell DA. The GTPase Rac-1 controls cell fate in the thymus by diverting thymocytes from positive to negative selection. Immunity 2001; 15:703-13. [PMID: 11728333 DOI: 10.1016/s1074-7613(01)00235-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The positive selection of CD4 or CD8 single-positive mature peripheral T lymphocytes and the deletion of self-reactive cells are crucial for central tolerance in the peripheral immune system. Previously, the guanine nucleotide binding protein Rac-1 has been shown to control pre-T cell development. The present report now describes the actions of Rac-1 in thymocyte selection. The study reveals that this molecule has the striking and unique ability to efficiently divert cells from positive selection into a pathway of negative selection and deletion. The ability of Rac-1 to switch thymocytes from a destiny of positive to negative selection identifies this molecule as a critical regulator of the developmental processes in T cells that are essential for immune homeostasis.
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Affiliation(s)
- M Gomez
- Imperial Cancer Research Fund, Lymphocyte Activation Laboratory, 44 Lincoln's Inn Fields, London, WC2A 3PX, United Kingdom
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72
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Wang J, Chun T, Lo JC, Wu Q, Wang Y, Foster A, Roca K, Chen M, Tamada K, Chen L, Wang CR, Fu YX. The critical role of LIGHT, a TNF family member, in T cell development. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:5099-105. [PMID: 11673520 DOI: 10.4049/jimmunol.167.9.5099] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Negative selection refers to the selective deletion of autoreactive thymocytes but its molecular events have not been well defined. In this study, we demonstrate that a cellular ligand for herpes virus entry mediator and lymphotoxin receptor (LIGHT), a newly identified member of the TNF superfamily, may play a critical role in negative selection. Using TCR transgenic mice, we find that the blockade of LIGHT signaling in vitro and in vivo prevents negative selection induced by peptide and intrathymically expressed Ags, resulting in the rescue of thymocytes from apoptosis. Furthermore, the thymi of LIGHT transgenic mice show severe atrophy with remarkably reduced CD4(+)CD8(+) double-positive cells caused by increased apoptosis, suggesting that LIGHT can delete immature T cells in vivo. Taken together, these results demonstrate a critical role of LIGHT in thymic negative selection of the T cell repertoire.
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Affiliation(s)
- J Wang
- Department of Pathology and Committee on Immunology, University of Chicago, Chicago, IL 60637, USA
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73
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Abstract
T-cell differentiation in the thymus generates a peripheral repertoire of mature T cells that mounts strong responses to foreign antigens but is largely unresponsive to self-antigens. This state of specific immunological tolerance to self-components involves both central and peripheral mechanisms. Here we review the process whereby many T cells with potential reactivity for self-antigens are eliminated in the thymus during early T-cell differentiation. This process of central tolerance (negative selection) reflects apoptosis and is a consequence of immature T cells receiving strong intracellular signalling through T-cell receptor (TCR) recognition of peptides bound to major histocompatibility complex (MHC) molecules. Central tolerance occurs mainly in the medullary region of the thymus and depends upon contact with peptide-MHC complexes expressed on bone-marrow-derived antigen-presenting cells (APCs); whether tolerance also occurs in the cortex is still controversial. Tolerance induction requires a combination of TCR ligation and co-stimulatory signals. Co-stimulation reflects interaction between complementary molecules on T cells and APCs and probably involves multiple molecules acting in consort, which may account for why deletion of individual molecules with known or potential co-stimulatory function has little or no effect on central tolerance. The range of self-antigens that induce central tolerance is considerable and, via low-level expression in the thymus, may also include tissue-specific antigens; central tolerance to these latter antigens, however, is likely to be limited to high-affinity T cells, leaving low-affinity cells to escape. Tolerance to alloantigens and the possibility of using central tolerance to promote acceptance of allografts are discussed.
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Affiliation(s)
- J Sprent
- Department of Immunology, IMM4, The Scripps Research Institute, 10550 North Torrey Pines Road, LaJolla, CA 92037, USA.
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74
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Berney SM, Schaan T, Wolf RE, Kimpel DL, van der Heyde H, Atkinson TP. CD5 (OKT1) augments CD3-mediated intracellular signaling events in human T lymphocytes. Inflammation 2001; 25:215-21. [PMID: 11580097 DOI: 10.1023/a:1010919719200] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
CD5 is expressed on thymocytes, all mature T cells, and a subset of mature B cells, and probably contributes to T-cell-B-cell adhesion. We assessed whether CD5-crosslinking by mAb augments T-cell stimulation. Plate-bound anti-CD5 or anti-CD3 mAb alone had no effect on any of the assessed activation parameters of resting T cells. However, concomitant signaling through both CD5 and CD3 by plate-bound antibodies resulted in marked increases in T-cell surface CD69 expression and T-cell metabolism, as assessed by the T cell's ability to reduce 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxylmethoxyphenyl)-2-(4-sulphophenyl)-2H-tetrazolium (MTS) to formazen. In addition, simultaneous cross-linking of CD5 and CD3 caused a significant (p < 0.001) increase in phosphatidylinositol hydrolysis in resting T cells compared to stimulation with anti-CD3 mAb alone or anti-CD3 mAb plus anti-CD5 isotype control antibody. These results indicate that CD5 augments signaling through CD3 and consequently functions as a costimulatory molecule for resting T cells.
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Affiliation(s)
- S M Berney
- Department of Medicine-Section of Rheumatology/Center of Excellence for Arthritis and Rheumatology, Shreveport, Louisiana 71130-3932, USA.
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75
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Li R, Page DM. Requirement for a complex array of costimulators in the negative selection of autoreactive thymocytes in vivo. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:6050-6. [PMID: 11342622 DOI: 10.4049/jimmunol.166.10.6050] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Autoreactive thymocytes can be deleted at an immature stage of their development by Ag-induced apoptosis or negative selection. In addition to Ag, negative selection also requires costimulatory signals from APC. We recently used a fetal thymus organ culture system to show that CD5, CD28, and TNF cooperatively regulate deletion of autoreactive thymocytes. Although these experiments provided strong evidence for the action of several costimulators in negative selection, we wished to demonstrate a role for these molecules in a physiologically natural model where thymocytes are deleted in vivo by endogenously expressed AGS: Accordingly, we examined thymocyte deletion in costimulator-null mice in three models of autoantigen-induced negative selection. We compared CD5(-/-) CD28(-/-) mice to CD40L(-/-) mice, which exhibited a profound block in negative selection in all three systems. Surprisingly, only one of the three models revealed a requirement for the CD5 and CD28 costimulators in autoantigen-induced deletion. These results suggest that an extraordinarily complex array of costimulators is involved in negative selection. We predict that different sets of costimulators will be required depending on the timing of negative selection, the Ag, the signal strength, the APC, and whether Ag presentation occurs on class I or class II MHC molecules.
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Affiliation(s)
- R Li
- Department of Biology and the Cancer Center, University of California at San Diego, La Jolla, CA 92093, USA
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76
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Wang EC, Thern A, Denzel A, Kitson J, Farrow SN, Owen MJ. DR3 regulates negative selection during thymocyte development. Mol Cell Biol 2001; 21:3451-61. [PMID: 11313471 PMCID: PMC100267 DOI: 10.1128/mcb.21.10.3451-3461.2001] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
DR3 (Ws1, Apo3, LARD, TRAMP, TNFSFR12) is a member of the death domain-containing tumor necrosis factor receptor (TNFR) superfamily, members of which mediate a variety of developmental events including the regulation of cell proliferation, differentiation, and apoptosis. We have investigated the in vivo role(s) of DR3 by generating mice congenitally deficient in the expression of the DR3 gene. We show that negative selection and anti-CD3-induced apoptosis are significantly impaired in DR3-null mice. In contrast, both superantigen-induced negative selection and positive selection are normal. The pre-T-cell receptor-mediated checkpoint, which is dependent on TNFR signaling, is also unaffected in DR3-deficient mice. These data reveal a nonredundant in vivo role for this TNF receptor family member in the removal of self-reactive T cells in the thymus.
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Affiliation(s)
- E C Wang
- Imperial Cancer Research Fund, Lincoln's Inn Fields, London WC2A 3PX, United Kingdom
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77
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McKean DJ, Huntoon CJ, Bell MP, Tai X, Sharrow S, Hedin KE, Conley A, Singer A. Maturation versus death of developing double-positive thymocytes reflects competing effects on Bcl-2 expression and can be regulated by the intensity of CD28 costimulation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:3468-75. [PMID: 11207305 DOI: 10.4049/jimmunol.166.5.3468] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Immature double-positive (DP) thymocytes mature into CD4(+)CD8(-) cells in response to coengagement of TCR with any of a variety of cell surface "coinducer" receptors, including CD2. In contrast, DP thymocytes are signaled to undergo apoptosis by coengagement of TCR with CD28 costimulatory receptors, but the molecular basis for DP thymocyte apoptosis by TCR plus CD28 coengagement is not known. In the present study, we report that TCR plus CD28 coengagement does not invariably induce DP thymocyte apoptosis but, depending on the intensity of CD28 costimulation, can induce DP thymocyte maturation. We demonstrate that distinct but interacting signal transduction pathways mediate DP thymocyte maturation signals and DP thymocyte apoptotic signals. Specifically, DP maturation signals are transduced by the extracellular signal-related kinase (ERK)/mitogen-activated protein kinase (MAPK) pathway and up-regulate expression of the antiapoptotic protein Bcl-2. In contrast, the apoptotic response stimulated by CD28 costimulatory signals is mediated by ERK/MAPK-independent pathways. Importantly, when TCR-activated thymocytes are simultaneously coengaged by both CD28 and CD2 receptors, CD28 signals can inhibit ERK/MAPK-dependent Bcl-2 protein up-regulation. Thus, there is cross-talk between the signal transduction pathways that transduce apoptotic and maturation responses, enabling CD28-initiated signal transduction pathways to both stimulate DP thymocyte apoptosis and also negatively regulate maturation responses initiated by TCR plus CD2 coengagement.
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MESH Headings
- Animals
- Apoptosis/immunology
- CD28 Antigens/immunology
- CD28 Antigens/metabolism
- CD28 Antigens/physiology
- CD4 Antigens/biosynthesis
- CD8 Antigens/biosynthesis
- Cell Differentiation/immunology
- Cells, Cultured
- Dose-Response Relationship, Immunologic
- Female
- Humans
- Immunophenotyping
- Lymphocyte Activation
- MAP Kinase Signaling System/immunology
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Proto-Oncogene Proteins c-bcl-2/biosynthesis
- Receptor Cross-Talk/immunology
- Receptors, Antigen, T-Cell/immunology
- Receptors, Antigen, T-Cell/metabolism
- Receptors, Antigen, T-Cell/physiology
- Signal Transduction/immunology
- T-Lymphocyte Subsets/cytology
- T-Lymphocyte Subsets/enzymology
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
- Thymus Gland/cytology
- Thymus Gland/enzymology
- Thymus Gland/immunology
- Thymus Gland/metabolism
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Affiliation(s)
- D J McKean
- Department of Immunology, Mayo Graduate School, Mayo Clinic, Rochester, MN 55905, USA.
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78
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Heinly CS, Sempowski GD, Lee DM, Patel DD, McDermott PM, Scearce RM, Thompson CB, Haynes BF. Comparison of thymocyte development and cytokine production in CD7-deficient, CD28-deficient and CD7/CD28 double-deficient mice. Int Immunol 2001; 13:157-66. [PMID: 11157849 DOI: 10.1093/intimm/13.2.157] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
CD7 and CD28 are Ig superfamily molecules expressed on thymocytes and mature T cells that share common signaling 0mechanisms and are co-mitogens for T cell activation. CD7-deficient mice are resistant to lipopolysaccharide (LPS)-induced shock syndrome, and have diminished in vivo LPS-triggered IFN-gamma and tumor necrosis factor (TNF)-alpha production. CD28-deficient mice have decreased serum Ig levels, defective IgG isotype switching, decreased T cell IL-2 production and are resistant to Staphylococcus aureus enterotoxin-induced shock. To determine synergistic roles CD7 and CD28 might play in thymocyte development and function, we have generated and characterized CD7/CD28 double-deficient mice. CD7/CD28-deficient mice were healthy, reproduced normally, had normal numbers of thymocyte subsets and had normal thymus histology. Anti-CD3 mAb induced similar levels of apoptosis in CD7-deficient, CD28-deficient and CD7/CD28 double-deficient thymocytes as in control C57BL/6 mice (P = NS). Similarly, thymocyte viability, apoptosis and necrosis following ionomycin or dexamethasone treatment were the same in control, CD7-deficient, CD28-deficient and CD7/CD28-deficient mice. CD28-deficient and CD7/CD28-deficient thymocytes had decreased [3H]thymidine incorporation responses to concanavalin A (Con A) stimulation compared to control mice (P < or = 0.01 and P < or = 0.05 respectively). CD7/CD28 double-deficient mice had significantly reduced numbers of B7-1/B7-2 double-positive cells compared to freshly isolated wild-type, CD7-deficient and CD28-deficient thymocytes. Con A-stimulated CD4/CD8 double-negative (DN) thymocytes from CD7/CD28 double-deficient mice expressed significantly lower levels of CD25 when compared to CD4/CD8 DN thymocytes from wild-type, CD7-deficient and CD28-deficient mice (P < 0.05). Anti-CD3-triggered CD7/CD28-deficient thymocytes also had decreased IFN-gamma and TNF-alpha production compared to C57BL/6 control, CD7-deficient and CD28-deficient mice (P < or = 0.05). Thus, CD7 and CD28 deficiencies combined to produce abnormalities in the absolute number of B7-1/B7-2-expressing cells in the thymus, thymocyte IL-2 receptor expression and CD3-triggered cytokine production.
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Affiliation(s)
- C S Heinly
- Division of Rheumatology, Allergy and Clinical Immunology, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
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79
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Pedraza-Alva G, Sawasdikosol S, Liu YC, Mérida LB, Cruz-Muñoz ME, Oceguera-Yañez F, Burakoff SJ, Rosenstein Y. Regulation of Cbl molecular interactions by the co-receptor molecule CD43 in human T cells. J Biol Chem 2001; 276:729-37. [PMID: 11024037 DOI: 10.1074/jbc.m008494200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
CD43, one of the most abundant glycoproteins on the T cell surface, has been implicated in selection and maturation of thymocytes and migration, adhesion, and activation of mature T cells. The adapter molecule Cbl has been shown to be a negative regulator of Ras. Furthermore, it may also regulate intracellular signaling through the formation of several multi-molecular complexes. Here we investigated the role of Cbl in the CD43-mediated signaling pathway in human T cells. Unlike T cell receptor signaling, the interaction of the adapter protein Cbl with Vav and phosphatidylinositol 3-kinase, resulting from CD43-specific signals, is independent of Cbl tyrosine phosphorylation, suggesting an alternative mechanism of interaction. CD43 signals induced a Cbl serine phosphorylation-dependent interaction with the tau-isoform of 14-3-3. protein. Protein kinase C-mediated Cbl serine phosphorylation was required for this interaction, because the PKC inhibitor RO-31-8220 prevented it, as well as 14-3-3 dimerization. Moreover, mutation of Cbl serine residues 619, 623, 639, and 642 abolished the interaction between Cbl and 14-3-3. Overexpression of Cbl in Jurkat cells inhibited the CD43-dependent activation of the mitogen-activated protein kinase (MAPK) pathway and AP-1 transcriptional activity, confirming nevertheless a negative role for Cbl in T cell signaling. However, under normal conditions, PKC activation resulting from CD43 engagement was required to activate the MAPK pathway, suggesting that phosphorylation of Cbl on serine residues by PKC and its association with 14-3-3 molecules may play a role in preventing the Cbl inhibitory effect on the Ras-MAPK pathway. These data suggest that by inducing its phosphorylation on serine residues, CD43-mediated signals may regulate the molecular associations and functions of the Cbl adapter protein.
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Affiliation(s)
- G Pedraza-Alva
- Instituto de Biotecnologia/Universidad Nacional Autónoma de México, Apartado Postal 510-3, Cuernavaca, MOR 62250, Mexico
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80
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Carlow DA, Corbel SY, Ziltener HJ. Absence of CD43 fails to alter T cell development and responsiveness. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:256-61. [PMID: 11123300 DOI: 10.4049/jimmunol.166.1.256] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Genetic elimination of CD43 has been associated with increased T cell adhesiveness and T cell hyperresponsiveness to mitogens and alloantigens. Therefore, we investigated whether T cell development was perturbed in CD43-deficient mice by breeding CD43(null) mice with male Ag (Hy)-specific TCR-transgenic mice. Neither positive nor negative thymic selection of male Ag-specific T cells were affected by CD43 status. Furthermore, we did not observe a substantial or consistent hyperresponsive pattern in HY-CD43(null) lymph node cells compared with littermate HY-CD43(+/-) lymph node cells upon analysis of in vitro T cell stimulation with male Ag or mitogen. These observations challenged original conclusions associating absence of CD43 with T cell hyperresponsiveness and led us to re-examine this association. Reported phenotypes of CD43(null) mice have been based on mice with a mixed 129xC57BL/6 genetic background. To exclude a possible influence of genetic background differences among individual mice we analyzed CD43(null) littermates that had been back-bred onto the C57BL/6 background for seven to eight generations. We found that CD43(+) and CD43(null) littermates with the C57BL/6 background exhibited no differences in response to mitogen or alloantigen, thereby establishing that T cell hyperresponsiveness is not a general correlate of CD43 absence.
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MESH Headings
- Animals
- Antigens, CD/biosynthesis
- Antigens, CD/genetics
- Cell Differentiation/genetics
- Cell Differentiation/immunology
- Cells, Cultured
- Crosses, Genetic
- Female
- H-Y Antigen/biosynthesis
- H-Y Antigen/genetics
- Leukosialin
- Lymphocyte Activation/genetics
- Male
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- Phenotype
- Receptors, Antigen, T-Cell/biosynthesis
- Receptors, Antigen, T-Cell/genetics
- Sex Factors
- Sialoglycoproteins/deficiency
- Sialoglycoproteins/genetics
- T-Lymphocytes/cytology
- T-Lymphocytes/immunology
- T-Lymphocytes/metabolism
- Thymus Gland/cytology
- Thymus Gland/immunology
- Thymus Gland/metabolism
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Affiliation(s)
- D A Carlow
- The Biomedical Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
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81
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Bugeon L, Hargreaves RE, Crompton T, Outram S, Rahemtulla A, Porter AC, Dallman MJ. Selective silencing of full-length CD80 but not IgV-CD80 leads to impaired clonal deletion of self-reactive T cells and altered regulation of immune responses. Eur J Immunol 2001; 31:118-27. [PMID: 11169445 DOI: 10.1002/1521-4141(200101)31:1<118::aid-immu118>3.0.co;2-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Co-stimulation provided by the B7 family of proteins underpins the development of protective immunity. There are three identified members of this family: CD80, its splice variant IgV-CD80 and CD86. It has hitherto been difficult to analyze the expression and function of IgV-CD80 since there are no appropriate reagents capable of distinguishing it from CD80. We have generated mice, by gene targeting, the lack CD80 whilst maintaining expression of IgV-CD80. Mutant animals did not delete T cells bearing mammary tumor virus-reactive TCR as efficiently as wild-type animals. We also demonstrate the importance of IgV-CD80 in the responses of recently activated cells and reveal a role for CD80 in sustaining T cell responses. CD86, whilst critical to primary T cell activation, made only a minor contribution to re-activation of normal cells.
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Affiliation(s)
- L Bugeon
- Department of Biology, Imperial College of Science Technology and Medicine, London, GB.
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82
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Godfrey DI, Purton JF, Boyd RL, Cole TJ. Stress-free T-cell development: glucocorticoids are not obligatory. IMMUNOLOGY TODAY 2000; 21:606-11. [PMID: 11114419 DOI: 10.1016/s0167-5699(00)01741-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A role for glucocorticoids in thymopoiesis has been suggested by studies using glucocorticoid receptor (GR) anti-sense transgenic mice, glucocorticoid synthesis inhibitors and GR antagonists. Unfortunately, no consensus has been reached on exactly how glucocorticoids influence T-cell development. The most recent approach, using GR knockout (GR(-/-)) mice, indicates that GR signaling is, in fact, dispensable in this entire process.
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MESH Headings
- Aminoglutethimide/pharmacology
- Animals
- Cell Differentiation/drug effects
- Clonal Deletion/drug effects
- DNA, Antisense/genetics
- Glucocorticoids/antagonists & inhibitors
- Glucocorticoids/deficiency
- Glucocorticoids/genetics
- Glucocorticoids/physiology
- Hematopoiesis/drug effects
- Hormone Antagonists/pharmacology
- Humans
- Immunologic Deficiency Syndromes/genetics
- Immunologic Deficiency Syndromes/immunology
- Lymphocyte Activation/drug effects
- Metyrapone/pharmacology
- Mice
- Mice, Knockout
- Mice, Transgenic
- Mifepristone/pharmacology
- Models, Biological
- Receptors, Glucocorticoid/deficiency
- Receptors, Glucocorticoid/drug effects
- Receptors, Glucocorticoid/genetics
- Receptors, Glucocorticoid/physiology
- Stress, Physiological/immunology
- Stress, Physiological/physiopathology
- T-Lymphocyte Subsets/cytology
- T-Lymphocyte Subsets/drug effects
- T-Lymphocyte Subsets/immunology
- Thymus Gland/embryology
- Thymus Gland/immunology
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Affiliation(s)
- D I Godfrey
- Monash University Medical School, Department of Pathology and Immunology, Commercial Road, VIC. 3181, Prahran, Australia.
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83
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DeYoung AL, Duramad O, Winoto A. The TNF receptor family member CD30 is not essential for negative selection. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 165:6170-3. [PMID: 11086050 DOI: 10.4049/jimmunol.165.11.6170] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
CD30 is a member of the TNF receptor superfamily that has been implicated in negative selection and some forms of peripheral tolerance. A previous study of CD30(-/-) mice in a class I-restricted H-Y TCR-transgenic mouse model showed that CD30 is essential for removal of autoreactive thymocytes. During the course of the studies of CD30 in the class II-restricted TCR-transgenic mice, we found that the absence of CD30 has no effect on negative selection. Surprisingly, we also found that the CD30 mutation does not perturb apoptosis of the autoreactive thymocytes in the class I-restricted H-Y TCR-transgenic model. The minimal role of CD30 in negative selection and other recent data are discussed.
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Affiliation(s)
- A L DeYoung
- Department of Molecular and Cell Biology, Division of Immunology and Cancer Research Laboratory, University of California, Berkeley, CA 94720, USA
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84
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Ebert PJ, Baker JF, Punt JA. Immature CD4+CD8+ thymocytes do not polarize lipid rafts in response to TCR-mediated signals. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 165:5435-42. [PMID: 11067895 DOI: 10.4049/jimmunol.165.10.5435] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
TCR-mediated stimulation induces activation and proliferation of mature T cells. When accompanied by signals through the costimulatory receptor CD28, TCR signals also result in the recruitment of cholesterol- and glycosphingolipid-rich membrane microdomains (lipid rafts), which are known to contain several molecules important for T cell signaling. Interestingly, immature CD4(+)CD8(+) thymocytes respond to TCR/CD28 costimulation not by proliferating, but by dying. In this study, we report that, although CD4(+)CD8(+) thymocytes polarize their actin cytoskeleton, they fail to recruit lipid rafts to the site of TCR/CD28 costimulation. We show that coupling of lipid raft mobilization to cytoskeletal reorganization can be mediated by phosphoinositide 3-kinase, and discuss the relevance of these findings to the interpretation of TCR signals by immature vs mature T cells.
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Affiliation(s)
- P J Ebert
- Department of Biology, Haverford College, Haverford, PA 19041, USA
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85
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Asada A, Zhao Y, Komano H, Kuwata T, Mukai M, Fujita K, Tozawa Y, Iseki R, Tian H, Sato K, Motegi Y, Suzuki R, Yokoyama M, Iwata M. The calcium-independent protein kinase C participates in an early process of CD3/CD28-mediated induction of thymocyte apoptosis. Immunology 2000; 101:309-15. [PMID: 11106933 PMCID: PMC2327094 DOI: 10.1046/j.1365-2567.2000.00110.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Thymocyte negative selection eliminates self-reactive clones and involves both a T-cell receptor (TCR)/CD3-mediated signal and a costimulatory signal, which can be delivered via CD28. Anti-CD3/anti-CD28-triggered apoptosis in isolated CD4+CD8+ thymocytes in vitro provides a basic model for negative selection. Effects of isoform-selective and non-isoform-selective inhibitors of protein kinase C (PKC) on this apoptotic process suggest that activation of Ca2+-independent PKC isoforms during the first 2-3 hr of culture is essential for inducing apoptosis, and that Ca2+-dependent PKC isoforms may be influential, but not essential, for apoptosis. To assess the CD3/CD28-mediated activation of PKC in the apoptotic process, we prepared CD4+CD8+ thymocytes (without contamination with cells that had received negative or positive selection signals in vivo) by establishing TCR-transgenic mice with RAG-2-deficient and non-selecting major histocompatibility complex (MHC) backgrounds, in addition to a CD4+CD8+ thymocyte-enriched population from normal mice. Translocation of Ca2+-independent PKC from the cytosolic fraction to the particulate fraction of CD4+CD8+ thymocytes was induced by CD3/CD28-mediated stimulation, but not by CD3- or CD28-mediated stimulation alone, and peaked 2 hr after the start of culture. The kinase activity of the translocated Ca2+-independent PKC was dependent on cofactors in vitro, indicating that novel (n)PKC, but not atypical (a)PKC or a proteolytic PKC fragment, was responsible for the activity. Immunoblotting analysis indicated that the nPKC-theta isoform was the major contributor among nPKC isoforms, and that the classical (c)PKC-alpha isoform was the major contributor among cPKC isoforms. These results suggest that activation of nPKC (especially the theta isoform) in CD4+CD8+ thymocytes is involved in a pathway for negative selection.
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Affiliation(s)
- A Asada
- Integrative Projects Center, Peptide Research and Reproductive Engineering, Mitsubishi Kasei Institute of Life Sciences, Machida-shi, Tokyo, Japan
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86
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Abstract
Self-tolerance induction is largely a reflection of negative selection (deletion) of autoreactive T cells in the thymus. Evidence is presented that negative selection occurs at a relatively late stage of thymocyte differentiation and affects a population of semimature HSA(hi) CD4+8- cells found in the medulla. Negative selection involves a number of cell-surface molecules on T cells, including Fas, CD28, CD5, and CD43. These molecules appear to act in consort, thereby ensuring that negative selection is highly efficient.
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Affiliation(s)
- H Kishimoto
- Department of Immunology, The Scripps Research Institute, La Jolla, CA 92037, USA
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87
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Belz GT, Stevenson PG, Doherty PC. Contemporary analysis of MHC-related immunodominance hierarchies in the CD8+ T cell response to influenza A viruses. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 165:2404-9. [PMID: 10946264 DOI: 10.4049/jimmunol.165.5.2404] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Early studies of influenza virus-specific CD8+ T cell-mediated immunity indicated that the level of CTL activity associated with H2Db is greatly diminished in mice that also express H2Kk. Such MHC-related immunodominance hierarchies are of some interest, as they could lead to variable outcomes for peptide-based vaccination protocols in human populations. The influence of H2Kk on the H2Db-restricted response profile has thus been looked at again using a contemporary, quantitative, IFN-gamma-based flow cytometric assay. The depressive effect of H2Kk was very apparent for the influenza DbPA224 epitope and was also reproduced when CTL activity was measured for H2Db-expressing targets pulsed with the immunodominant NP366 peptide. The secondary CD8+IFN-gamma+ DbNP366-specific response was much greater in parental H2b than in H2kxbF1 mice, but the sizes of the CD8+ sets specific for KkNP50 and DbNP366 were essentially equivalent in the F1 animals. Thus, although the immunodominance profile associated with DbNP366 is lost when H2Kk is also present, the response is still substantial. A further, MHC-related effect was also identified for the KkNS1152 epitope, which was consistently associated with a greater CD8+IFN-gamma+ response in H2KkDb recombinant than in (H2KkDk x H2KbDb)F1 mice. The diminished DbPA224 response in H2kxbF1 mice was characterized by loss of a prominent Vbeta7 TCR responder phenotype, supporting the idea that TCR deletion during ontogeny shapes the available repertoire. The overall conclusion is that these MHC-related immunodominance hierarchies are more subtle than the early CTL assays suggested and, although inherently unpredictable, are unlikely to cause a problem for peptide-based vaccine strategies.
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MESH Headings
- Animals
- CD8 Antigens/biosynthesis
- CD8-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/virology
- Cell Line
- Crosses, Genetic
- Epitopes, T-Lymphocyte/genetics
- Epitopes, T-Lymphocyte/immunology
- Female
- H-2 Antigens/genetics
- H-2 Antigens/immunology
- Hemagglutinin Glycoproteins, Influenza Virus/immunology
- Histocompatibility Antigen H-2D
- Immunodominant Epitopes/genetics
- Immunodominant Epitopes/immunology
- Immunologic Memory/genetics
- Immunophenotyping
- Influenza A virus/immunology
- Interferon-gamma/biosynthesis
- Lymphocyte Activation/genetics
- Mice
- Mice, Inbred C3H
- Mice, Inbred C57BL
- Peptide Fragments/immunology
- RNA-Dependent RNA Polymerase
- Receptors, Antigen, T-Cell, alpha-beta/biosynthesis
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
- T-Lymphocytes, Cytotoxic/immunology
- T-Lymphocytes, Cytotoxic/virology
- Viral Nonstructural Proteins/immunology
- Viral Proteins/immunology
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Affiliation(s)
- G T Belz
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
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88
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Lucas B, Germain RN. Opening a window on thymic positive selection: developmental changes in the influence of cosignaling by integrins and CD28 on selection events induced by TCR engagement. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 165:1889-95. [PMID: 10925269 DOI: 10.4049/jimmunol.165.4.1889] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
How TCR and non-TCR signals are integrated by thymocytes to generate a decision to undergo either positive or negative selection remains incompletely understood. Recent evidence suggests that TCR signal transduction changes its quality during thymocyte maturation, but whether the contributions of various cosignaling or costimulatory pathways to thymocyte selection also are modified during development is unclear. Questions also remain about the possible selective roles of specific costimulatory pathways in induction of differentiation vs death among thymocytes at any given stage of maturity. To address these issues, a quantitative in vitro analysis of initiation of CD4+CD8+ thymocyte differentiation as measured by CD69 up-regulation/coreceptor down-modulation was conducted in parallel with an analysis of induction of death. Using transfected cells varying in their surface display of ICAM-1 or B7.1 along with antibody blocking experiments, we demonstrate here that ICAM-1 provides a selective boost to signaling for differentiation without substantially affecting induction of death among CD4+CD8+ cells, a property that is lost as thymocytes mature further. In contrast, B7 engagement enhances both cell activation and death in parallel. Based on these data, we propose that the high level of ICAM-1 on cortical epithelial cells plays a special role in opening a window between TCR signaling for differentiation vs death, permitting efficient initiation of positive selection on epithelial ligands. In contrast, late CD28-dependent cosignaling on hemopoietic cells in the medulla would help enforce negative selection by augmenting the effects of TCR engagement by low levels of high affinity ligands.
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Affiliation(s)
- B Lucas
- Institut National de la Santé et de la Recherche Médicale, Unité 345, Institut Necker, Paris, France
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89
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Purton JF, Boyd RL, Cole TJ, Godfrey DI. Intrathymic T cell development and selection proceeds normally in the absence of glucocorticoid receptor signaling. Immunity 2000; 13:179-86. [PMID: 10981961 DOI: 10.1016/s1074-7613(00)00018-2] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Glucocorticoids are believed to play a role in T cell development and selection, although their precise function is controversial. Glucocorticoid receptor (GR)-deficient mice were used to directly investigate this problem. GR-deficient thymocytes were resistant to dexamethasone-mediated apoptosis, confirming the absence of glucocorticoid responsiveness. An absence of GR signaling had no impact on thymocyte development either in vivo or in vitro. T cell differentiation, including positive selection, was normal as assessed by normal development of CD4+CD8+, alphabetaTCR+CD4+, and alphabetaTCR+CD8+ thymocytes. Negative selection, mediated by the superantigen staphylococcal enterotoxin B (SEB), or anti-CD3/CD28, was also normal in the absence of GR signaling. In contrast to earlier reports, these data demonstrate that GR signaling is not essential for intrathymic T cell development or selection.
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Affiliation(s)
- J F Purton
- Department of Pathology and Immunology, Monash University Medical School, Prahran, Victoria, Australia
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90
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Popović P, Colić M, Vucević D, Gasić S, Pavicić L. Comparison of signaling pathways involved in apoptosis of a thymocyte hybridoma triggered by a rat thymic medullary epithelial cell line, dexamethasone or T-cell receptor cross-linking. Immunol Lett 2000; 72:83-91. [PMID: 10841942 DOI: 10.1016/s0165-2478(00)00165-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Using an in vitro co-culture assay we found that a rat medullary thymic epithelial cell (TEC) line (TE-R2.5) induces apoptosis of the BWRT8 thymocyte hybridoma (TH) (CD4(hi)CD8(low) alphabetaTCR(hi)). TH apoptosis induced by this TEC line was predominantly mediated by direct cell-cell contacts and was potentiated by cross-linking of the T cell receptor (TCR) by R73 monoclonal antibody (mAb). Dexamethasone (Dx) also triggered TH apoptosis but inhibited death of these cells induced by TE-R2.5 cells or immobilized R73 mAb. The TEC-induced apoptosis was independent of the LFA-1/ICAM-1 interaction but partly depended on a novel 29 kDa molecule expressed on TE-R2.5 cells. All three types of TH apoptosis were followed by the cleavage of poly-(ADP-ribose)-polymerase and were blocked by a caspase inhibitor Z-Val-Ala-Asp(OMe)-CH(2)F.PKC stimulation by phorbol myristate acetate interfered with the TH apoptosis induced by TE-R2.5 and Dx, but did not modulate the effect of R73 mAb. On the contrary, inhibition of calcineurin with cyclosporine A did not influence the apoptosis induced by TE-R2.5 and Dx, but completely prevented the R73-triggered TH cell death. The TE-R2.5-mediated BWRT8 apoptosis was suppressed by Na-orthovanadate, an inhibitor of protein tyrosine phosphatases (PTP) as well as by genistein, a protein tyrosine kinase (PTK) inhibitor, while both compounds potentiated the effect of Dx. Blocking PTP, but not PTK decreased the proapoptotic effect of R73 mAb. These results, including those using a BWRT8 subclone (BWRT8-MDP.2) which is resistant to TCR-triggered apoptosis, but sensitive to apoptosis stimulated by TE-R2.5 and Dx, indicate that TE-R2.5-induced TH apoptosis in our model is different from apoptosis in other TEC co-culture models, published so far.
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Affiliation(s)
- P Popović
- Institue of Medical Research, Military Medical Academy, Crnotravska 17, 11002, Belgrade, Yugoslavia
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91
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Abstract
T cell tolerance to self-components occurs largely in the thymus during early differentiation and leads to death (negative selection) of T cells with overt autoreactivity. In this article we review the evidence that negative selection in mice occurs mainly in the medulla at the level of a population of semimature T cells. The role of Fas and several costimulatory molecules on negative selection and the inhibitory role of certain cytokines are discussed.
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Affiliation(s)
- H Kishimoto
- Department of Immunology, IMM4, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
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92
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Nakajima H, Noguchi M, Leonard WJ. Role of the common cytokine receptor gamma chain (gammac) in thymocyte selection. IMMUNOLOGY TODAY 2000; 21:88-94. [PMID: 10652467 DOI: 10.1016/s0167-5699(99)01555-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
During thymocyte development, T-cell receptor (TCR) alphabeta-mediated intracellular signals can elicit two entirely different cellular responses: positive selection (resulting in rescue from death and maturation or differentiation) and negative selection (induction of apoptosis). Here, Hiroshi Nakajima and colleagues discuss how survival signals that are dependent on the common cytokine receptor gamma chain (gammac) might affect the TCR-driven selection process in thymocytes, underscoring the potential role of cytokines in this process.
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Affiliation(s)
- H Nakajima
- Dept of Internal Medicine II, Chiba University School of Medicine, Chiba 260-8670, Japan
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93
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Abstract
Apoptosis is the fate of most thymocytes. Many molecules participate in the decision of whether a thymocyte is to live or to die, including cell surface receptors, such as the T cell receptor for antigen, Notch-1, and costimulatory receptors, ligand-regulated nuclear transcription factors such as the glucocorticoid receptor, signaling, and effector proteases, and direct regulators of the apoptotic machinery such IAPs. In this review we discuss recent data concerning these molecules and pathways and their implication for understanding the mechanisms underlying thymocyte death, survival, and the generation of inmmunocompetent T cells.
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Affiliation(s)
- Y Yang
- Laboratory of Immune Cell Biology, Division of Basic Sciences, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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