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Ciesielska-Figlon K, Lisowska KA. The Role of the CD28 Family Receptors in T-Cell Immunomodulation. Int J Mol Sci 2024; 25:1274. [PMID: 38279272 PMCID: PMC10816057 DOI: 10.3390/ijms25021274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/14/2024] [Accepted: 01/18/2024] [Indexed: 01/28/2024] Open
Abstract
The CD28 family receptors include the CD28, ICOS (inducible co-stimulator), CTLA-4 (cytotoxic T-lymphocyte antigen-4), PD-1 (programmed cell death protein 1), and BTLA (B- and T-lymphocyte attenuator) molecules. They characterize a group of molecules similar to immunoglobulins that control the immune response through modulating T-cell activity. Among the family members, CD28 and ICOS act as enhancers of T-cell activity, while three others-BTLA, CTLA-4, and PD-1-function as suppressors. The receptors of the CD28 family interact with the B7 family of ligands. The cooperation between these molecules is essential for controlling the course of the adaptive response, but it also significantly impacts the development of immune-related diseases. This review introduces the reader to the molecular basis of the functioning of CD28 family receptors and their impact on T-cell activity.
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2
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Caruso B, Moran AE. Thymic expression of immune checkpoint molecules and their implication for response to immunotherapies. Trends Cancer 2023:S2405-8033(23)00063-8. [PMID: 37173189 DOI: 10.1016/j.trecan.2023.04.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 04/07/2023] [Accepted: 04/14/2023] [Indexed: 05/15/2023]
Abstract
The thymus is responsible for generating a diverse T cell repertoire that is tolerant to self, but capable of responding to various immunologic insults, including cancer. Checkpoint blockade has changed the face of cancer treatment by targeting inhibitory molecules, which are known to regulate peripheral T cell responses. However, these inhibitory molecules and their ligands are expressed during T cell development in the thymus. In this review, we describe the underappreciated role of checkpoint molecule expression during the formation of the T cell repertoire and detail the importance of inhibitory molecules in regulating T cell lineage commitment. Understanding how these molecules function in the thymus may inform therapeutic strategies for better patient outcomes.
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Affiliation(s)
- Breanna Caruso
- Cell, Developmental and Cancer Biology, Oregon Health and Science University, Portland, OR, USA
| | - Amy E Moran
- Cell, Developmental and Cancer Biology, Oregon Health and Science University, Portland, OR, USA; Knight Cancer Institute, Oregon Health and Science University, Portland, OR, USA.
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3
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Dong M, Chang J, Lebel MÈ, Gervais N, Fournier M, Mallet Gauthier È, Suh WK, Melichar HJ. The ICOS-ICOSL pathway tunes thymic selection. Immunol Cell Biol 2021; 100:205-217. [PMID: 34962663 PMCID: PMC9304562 DOI: 10.1111/imcb.12520] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Revised: 12/11/2021] [Accepted: 12/27/2021] [Indexed: 11/30/2022]
Abstract
Negative selection of developing T cells plays a significant role in T cell tolerance to self-antigen. This process relies on thymic antigen presenting cells which express both self-antigens as well as co-signaling molecules. Inducible T cell costimulator (ICOS) belongs to the CD28 family of co-signaling molecules and binds to ICOS ligand (ICOSL). The ICOS signaling pathway plays important roles in shaping the immune response to infections, but its role in central tolerance is less well understood. Here we show that ICOSL is expressed by subsets of thymic dendritic cells and medullary thymic epithelial cells as well as thymic B cells. ICOS expression is upregulated as T cells mature in the thymus and correlates with T cell receptor signal strength during thymic selection. We also provide evidence of a role for ICOS signaling in mediating negative selection. Our findings suggest that ICOS may fine-tune T cell receptor signals during thymic selection contributing to the generation of a tolerant T cell population.
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Affiliation(s)
- Mengqi Dong
- Département de microbiologie, Université de Montréal, infectiologie et immunologie, Montréal, Québec, H3T 1J4, Canada.,Immunology-Oncology Unit, Maisonneuve-Rosemont Hospital Research Center, Montréal, Québec, H1T 2M4, Canada
| | - Jinsam Chang
- Institut de recherches cliniques de Montréal, Montréal, Québec, H2W 1R7, Canada.,Programme de biologie moléculaire, Université de Montréal, Montréal, Québec, H3T 1J4, Canada
| | - Marie-Ève Lebel
- Immunology-Oncology Unit, Maisonneuve-Rosemont Hospital Research Center, Montréal, Québec, H1T 2M4, Canada
| | - Noémie Gervais
- Immunology-Oncology Unit, Maisonneuve-Rosemont Hospital Research Center, Montréal, Québec, H1T 2M4, Canada
| | - Marilaine Fournier
- Immunology-Oncology Unit, Maisonneuve-Rosemont Hospital Research Center, Montréal, Québec, H1T 2M4, Canada
| | - Ève Mallet Gauthier
- Département de microbiologie, Université de Montréal, infectiologie et immunologie, Montréal, Québec, H3T 1J4, Canada.,Immunology-Oncology Unit, Maisonneuve-Rosemont Hospital Research Center, Montréal, Québec, H1T 2M4, Canada
| | - Woong-Kyung Suh
- Département de microbiologie, Université de Montréal, infectiologie et immunologie, Montréal, Québec, H3T 1J4, Canada.,Institut de recherches cliniques de Montréal, Montréal, Québec, H2W 1R7, Canada.,Programme de biologie moléculaire, Université de Montréal, Montréal, Québec, H3T 1J4, Canada
| | - Heather J Melichar
- Immunology-Oncology Unit, Maisonneuve-Rosemont Hospital Research Center, Montréal, Québec, H1T 2M4, Canada.,Département de médecine, Université de Montréal, Montréal, Québec, H3T 1J4, Canada
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Watanabe M, Lu Y, Breen M, Hodes RJ. B7-CD28 co-stimulation modulates central tolerance via thymic clonal deletion and Treg generation through distinct mechanisms. Nat Commun 2020; 11:6264. [PMID: 33293517 PMCID: PMC7722925 DOI: 10.1038/s41467-020-20070-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 11/09/2020] [Indexed: 12/22/2022] Open
Abstract
The molecular and cellular mechanisms mediating thymic central tolerance and prevention of autoimmunity are not fully understood. Here we show that B7-CD28 co-stimulation and B7 expression by specific antigen-presenting cell (APC) types are required for clonal deletion and for regulatory T (Treg) cell generation from endogenous tissue-restricted antigen (TRA)-specific thymocytes. While B7-CD28 interaction is required for both clonal deletion and Treg induction, these two processes differ in their CD28 signaling requirements and in their dependence on B7-expressing dendritic cells, B cells, and thymic epithelial cells. Meanwhile, defective thymic clonal deletion due to altered B7-CD28 signaling results in the accumulation of mature, peripheral TRA-specific T cells capable of mediating destructive autoimmunity. Our findings thus reveal a function of B7-CD28 co-stimulation in shaping the T cell repertoire and limiting autoimmunity through both thymic clonal deletion and Treg cell generation.
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MESH Headings
- Animals
- Antigen-Presenting Cells/metabolism
- Autoimmunity/physiology
- B7-1 Antigen/metabolism
- CD28 Antigens/genetics
- CD28 Antigens/metabolism
- Cell Differentiation/immunology
- Central Tolerance
- Clonal Deletion
- Encephalomyelitis, Autoimmune, Experimental/immunology
- Flow Cytometry
- Gene Knock-In Techniques
- Mice
- Mice, Knockout
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/metabolism
- Signal Transduction/immunology
- T-Lymphocytes, Regulatory/immunology
- T-Lymphocytes, Regulatory/metabolism
- Thymocytes/physiology
- Thymus Gland/cytology
- Thymus Gland/immunology
- Thymus Gland/metabolism
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Affiliation(s)
- Masashi Watanabe
- Experimental Immunology Branch, National Cancer Institute, Bethesda, MD, 20892, USA
| | - Ying Lu
- Experimental Immunology Branch, National Cancer Institute, Bethesda, MD, 20892, USA
| | - Michael Breen
- Experimental Immunology Branch, National Cancer Institute, Bethesda, MD, 20892, USA
| | - Richard J Hodes
- Experimental Immunology Branch, National Cancer Institute, Bethesda, MD, 20892, USA.
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5
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Abstract
Induction of specific immune tolerance to grafts remains the sought-after standard following transplantation. Defined by expression of the Foxp3 (forkhead box protein 3) transcription factor, the regulatory T-cell (Treg) lineage has been noted to exert potent immunoregulatory functions that contribute to specific graft tolerance. In this review, we discuss the known signals and pathways which govern Treg development, both in the thymus and in peripheral sites, as well as lineage maintenance and homeostasis. In particular, we highlight the roles of T-cell receptor signaling, CD28 costimulation, and signals through phosphatidyl inositol 3-kinase (PI3K) and related metabolic pathways in multiple aspects of Treg biology.
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Affiliation(s)
- Alexandria Huynh
- Division of Medical Sciences, Harvard Medical School, Boston, MA, USA; Transplantation Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
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Abstract
T cell activation is a key event in the adaptive immune response and vital to the generation of both cellular and humoral immunity. Activation is required not only for effective CD4 T cell responses but also to provide help for B cells and the generation of cytotoxic T cell responses. Unsurprisingly, impaired T cell activation results in infectious pathology, whereas dysregulated activation can result in autoimmunity. The decision to activate is therefore tightly regulated and the CD28/CTLA-4 pathway represents this apical decision point at the molecular level. In particular, CTLA-4 (CD152) is an essential checkpoint control for autoimmunity; however, the molecular mechanism(s) by which CTLA-4 achieves its regulatory function are not well understood, especially how it functionally intersects with the CD28 pathway. In this chapter, we review the established molecular and cellular concepts relating to CD28 and CTLA-4 biology, and attempt to integrate these by discussing the transendocytosis of ligands as a new model of CTLA-4 function.
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Affiliation(s)
- Blagoje Soskic
- School of Immunity and Infection, University of Birmingham, Birmingham, United Kingdom
| | | | - Tiezheng Hou
- UCL Institute of Immunity and Transplantation, Royal Free Campus, London, United Kingdom
| | - David M Sansom
- UCL Institute of Immunity and Transplantation, Royal Free Campus, London, United Kingdom.
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7
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Williams JA, Zhang J, Jeon H, Nitta T, Ohigashi I, Klug D, Kruhlak MJ, Choudhury B, Sharrow SO, Granger L, Adams A, Eckhaus MA, Jenkinson SR, Richie ER, Gress RE, Takahama Y, Hodes RJ. Thymic medullary epithelium and thymocyte self-tolerance require cooperation between CD28-CD80/86 and CD40-CD40L costimulatory pathways. THE JOURNAL OF IMMUNOLOGY 2013; 192:630-40. [PMID: 24337745 DOI: 10.4049/jimmunol.1302550] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A critical process during thymic development of the T cell repertoire is the induction of self-tolerance. Tolerance in developing T cells is highly dependent on medullary thymic epithelial cells (mTEC), and mTEC development in turn requires signals from mature single-positive thymocytes, a bidirectional relationship termed thymus crosstalk. We show that CD28-CD80/86 and CD40-CD40L costimulatory interactions, which mediate negative selection and self-tolerance, upregulate expression of LTα, LTβ, and receptor activator for NF-κB in the thymus and are necessary for medullary development. Combined absence of CD28-CD80/86 and CD40-CD40L results in profound deficiency in mTEC development comparable to that observed in the absence of single-positive thymocytes. This requirement for costimulatory signaling is maintained even in a TCR transgenic model of high-affinity TCR-ligand interactions. CD4 thymocytes maturing in the altered thymic epithelial environment of CD40/CD80/86 knockout mice are highly autoreactive in vitro and are lethal in congenic adoptive transfer in vivo, demonstrating a critical role for these costimulatory pathways in self-tolerance as well as thymic epithelial development. These findings demonstrate that cooperativity between CD28-CD80/86 and CD40-CD40L pathways is required for normal medullary epithelium and for maintenance of self-tolerance in thymocyte development.
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Affiliation(s)
- Joy A Williams
- Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
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8
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Abstract
CD28 costimulation regulates a wide range of cellular processes, from proliferation and survival to promoting the differentiation of specialized T-cell subsets. Since first being identified over 20 years ago, CD28 has remained a subject of intense study because of its profound consequences on T cell function and its potential for therapeutic manipulation. In this review we highlight the signaling cascades initiated by the major signaling motifs in CD28, focusing on PI-3 kinase-dependent and -independent pathways and how these are linked to specific cellular outcomes. Recent studies using gene targeted knockin mice have clarified the relative importance of these motifs on in vivo immune responses; however, much remains to be elucidated. Understanding the mechanism behind costimulation holds great potential for development of new clinically relevant reagents, a fact beginning to be realized with the advent of drugs that prevent CD28 ligation and signaling.
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Affiliation(s)
- Jonathan S Boomer
- Department of Internal Medicine, Washington University School of Medicine, St Louis, Missouri 63110, USA
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Zhou P, Zheng X, Zhang H, Liu Y, Zheng P. B7 blockade alters the balance between regulatory T cells and tumor-reactive T cells for immunotherapy of cancer. Clin Cancer Res 2009; 15:960-70. [PMID: 19188167 DOI: 10.1158/1078-0432.ccr-08-1611] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
PURPOSE In prostate cancer-bearing host, regulatory T (Treg) cells restrain activity of tumor antigen-specific T cells. Because B7:CD28 interactions are needed for both function of CD4+CD25+ Treg cells and CD8+ effective T cells, targeting this pathway may help to overcome the immunotherapy barriers. EXPERIMENTAL DESIGN The anti-B7-1/B7-2 monoclonal antibodies were administered to a transgenic mouse model of prostate cancer (TRAMP) ectopically expressing SV40 large T antigen in different tumor development stages for prevention and therapy of prostate cancer. The treatment was also tested in treating transplanted MC38 colon adenocarcinoma in mice. RESULTS Here, we showed that short-term administration of anti-B7-1/B7-2 monoclonal antibodies in TRAMP mice leads to significant inhibited primary tumor growth and the size of metastatic lesions. The treatment is effective to inhibit MC38 colon cancer growth. Correspondingly, this treatment results in a transient reduction of Treg in both thymus and the periphery. In vivo cytotoxicity assay revealed T antigen-specific CTL effectors in anti-B7-treated but not control IgG-treated TRAMP mice. CONCLUSIONS Transient blockade of B7-1/B7-2 alters the balance between Treg and cancer-reactive T cells to enhance cancer immunotherapy.
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Affiliation(s)
- Penghui Zhou
- Department of Surgery and Pathology, University of Michigan Medical Center, Program of Molecular Mechanism of Diseases and Comprehensive Cancer Center, Ann Arbor, Michigan 48109, USA
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10
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Abstract
Although the inhibitory receptor CTLA-4 (CD152) has been implicated in peripheral CD4 T-cell tolerance, its mechanism of action remains poorly defined. We analyzed mechanisms of CD4 cell tolerance in a model of tolerance induction involving establishment of mixed hematopoietic chimerism in recipients of fully MHC-mismatched allogeneic bone marrow cells with anti-CD154 mAb. Animals lacking CD80 and CD86 failed to achieve chimerism. We detected no T cell-intrinsic requirement for CD28 for chimerism induction. However, a CD4 T cell-intrinsic signal through CTLA-4 was shown to be essential within the first 48 hours of exposure to alloantigen for the establishment of tolerance and mixed chimerism. This signal must be provided by a recipient CD80/86(+) non-T-cell population. Donor CD80/86 expression was insufficient to achieve tolerance. Together, our findings demonstrate a surprising role for interactions of CTLA-4 expressed by alloreactive peripheral CD4 T cells with CD80/86 on recipient antigen-presenting cells (APCs) in the induction of early tolerance, suggesting a 3-cell tolerance model involving directly alloreactive CD4 cells, donor antigen-expressing bone marrow cells, and recipient antigen-presenting cells. This tolerance is independent of regulatory T cells and culminates in the deletion of directly alloreactive CD4 T cells.
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11
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Williams JA, Lumsden JM, Yu X, Feigenbaum L, Zhang J, Steinberg SM, Hodes RJ. Regulation of thymic NKT cell development by the B7-CD28 costimulatory pathway. THE JOURNAL OF IMMUNOLOGY 2008; 181:907-17. [PMID: 18606642 DOI: 10.4049/jimmunol.181.2.907] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Invariant NKT (iNKT) cells are a population of TCRalphabeta-expressing cells that are unique in several respects. In contrast to conventional T cells, iNKT cells are selected in the thymus for recognition of CD1, rather than conventional MHC class I or II, and are selected by CD1-expressing double-positive thymocytes, rather than by the thymic stromal cells responsible for positive selection of conventional T cells. We have probed further the requirements for thymic iNKT cell development and find that these cells are highly sensitive to B7-CD28 costimulatory interactions, as evidenced by the substantially decreased numbers of thymic iNKT cells in CD28 and in B7 knockout mice. In contrast to the requirement for CD1, B7-CD28 signaling does not affect early iNKT cell lineage commitment, but exerts its influence on the subsequent intrathymic expansion and differentiation of iNKT cells. CD28 wild-type/CD28-deficient mixed bone marrow chimeras provided evidence of both cell-autonomous and non-cell-autonomous roles for CD28 during iNKT cell development. Paradoxically, transgenic mice in which thymic expression of B7 is elevated have essentially no measurable thymic iNKT cells. Taken together, these results demonstrate that the unique pathway involved in iNKT cell development is marked by a critical role of B7-CD28 interactions and that disruption or augmentation of this costimulatory interaction has substantial effects on iNKT cell development in the thymus.
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Affiliation(s)
- Joy A Williams
- Experimental Immunology Branch, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
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12
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Kasler HG, Verdin E. Histone deacetylase 7 functions as a key regulator of genes involved in both positive and negative selection of thymocytes. Mol Cell Biol 2007; 27:5184-200. [PMID: 17470548 PMCID: PMC1951960 DOI: 10.1128/mcb.02091-06] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Histone deacetylase 7 (HDAC7) is highly expressed in CD4(+)/CD8(+) thymocytes and functions as a signal-dependent repressor of gene transcription during T-cell development. In this study, we expressed HDAC7 mutant proteins in a T-cell line and use DNA microarrays to identify transcriptional targets of HDAC7 in T cells. The changes in gene expression levels were compared to differential gene expression profiles associated with positive and negative thymic selection. This analysis reveals that HDAC7 regulates an extensive set of genes that are differentially expressed during both positive and negative thymic selection. Many of these genes play important functional roles in thymic selection, primarily via modulating the coupling between antigen receptor engagement and downstream signaling events. Consistent with the model that HDAC7 may play an important role in both positive and negative thymic selection, the expression of distinct HDAC7 mutants or the abrogation of HDAC7 expression can either enhance or inhibit the signal-dependent differentiation of a CD4(+)/CD8(+) cell line.
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Affiliation(s)
- Herbert G Kasler
- Gladstone Institute of Virology and Immunology, 1650 Owens Street, San Francisco, CA 94158, USA
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13
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Graham DB, Bell MP, Huntoon CJ, Griffin MD, Tai X, Singer A, McKean DJ. CD28 ligation costimulates cell death but not maturation of double-positive thymocytes due to defective ERK MAPK signaling. THE JOURNAL OF IMMUNOLOGY 2006; 177:6098-107. [PMID: 17056536 DOI: 10.4049/jimmunol.177.9.6098] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The differentiation of double-positive (DP) CD4(+)CD8(+) thymocytes to single-positive CD4(+) or CD8(+) T cells is regulated by signals that are initiated by coengagement of the Ag (TCR) and costimulatory receptors. CD28 costimulatory receptors, which augment differentiation and antiapoptotic responses in mature T lymphocytes, have been reported to stimulate both differentiation and apoptotic responses in TCR-activated DP thymocytes. We have used artificial APCs that express ligands for TCR and CD28 to show that CD28 signals increase expression of CD69, Bim, and cell death in TCR-activated DP thymocytes but do not costimulate DP thymocytes to initiate the differentiation program. The lack of a differentiation response is not due to defects in CD28-initiated TCR proximal signaling events but by a selective defect in the activation of ERK MAPK. To characterize signals needed to initiate the death response, a mutational analysis was performed on the CD28 cytoplasmic domain. Although mutation of all of CD28 cytoplasmic domain signaling motifs blocks cell death, the presence of any single motif is able to signal a death response. Thus, there is functional redundancy in the CD28 cytoplasmic domain signaling motifs that initiate the thymocyte death response. In contrast, immobilized Abs can initiate differentiation responses and cell death in DP thymocytes. However, because Ab-mediated differentiation occurs through CD28 receptors with no cytoplasmic domain, the response may be mediated by increased adhesion to immobilized anti-TCR Abs.
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Affiliation(s)
- Daniel B Graham
- Department of Immunology, Mayo Clinic College of Medicine,301 Guggenheim Building, Rochester, MN 55905, USA
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Tuckermann JP, Kleiman A, McPherson KG, Reichardt HM. Molecular mechanisms of glucocorticoids in the control of inflammation and lymphocyte apoptosis. Crit Rev Clin Lab Sci 2005; 42:71-104. [PMID: 15697171 DOI: 10.1080/10408360590888983] [Citation(s) in RCA: 148] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The immune system must be tightly controlled not only to guarantee efficient protection from invading pathogens and oncogenic cells but also to avoid exaggerated immune responses and autoimmunity. This is achieved through interactions amongst leukocytes themselves, by signals from stromal cells and also by various hormones, including glucocorticoids. The glucocorticoids are a class of steroid hormones that exert a wide range of anti-inflammatory and immunosuppressive activities after binding to the glucocorticoid receptor. The power of these hormones was acknowledged many decades ago, and today synthetic derivatives are widely used in the treatment of inflammatory disorders, autoimmunity and cancer. In this review, we summarize our present knowledge of the molecular mechanisms of glucocorticoid action, their influence on specific leukocytes and the induction of thymocyte apoptosis, with an emphasis on how molecular genetics has contributed to our growing, although still incomplete, understanding of these processes.
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Vacchio MS, Williams JA, Hodes RJ. A novel role for CD28 in thymic selection: elimination of CD28/B7 interactions increases positive selection. Eur J Immunol 2005; 35:418-27. [PMID: 15657954 DOI: 10.1002/eji.200424918] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
While the importance of the CD28/B7 costimulation pathway is well established for mature T cells, the role of CD28 in thymocyte selection is less well defined. The role of CD28 in both negative and positive selection was assessed using H-Y-specific TCR-transgenic (Tg) RAG-2-deficient (H-Yrag) mice. Negative selection in male H-Yrag mice was not affected by deficiency in CD28 or B7. Surprisingly, absence of CD28 or B7 in H-Yrag females resulted in increased numbers of CD8 single-positive (SP) thymocytes. The CD8 SP thymocytes found in these females were mature and functionally competent. Furthermore, double-positive (DP) thymocytes from CD28-knockout (CD28KO) or B7.1/B7.2 double-KO (B7DKO) females had higher levels of both CD5 and TCR than those from WT females, consistent with a stronger selecting signal. CD28KO H-Yrag fetal thymic organ cultures also had elevated numbers of thymic CD8 SP cells, reflecting increased thymic differentiation and not recirculation of peripheral T cells. Finally, increased selection of mature CD4 and CD8 SP T cells was observed in non-TCR-Tg CD28KO and B7DKO mice, indicating that this function of CD28-B7 interaction is not unique to a TCR-Tg model. Together these findings demonstrate a novel negative regulatory role for CD28 in inhibiting differentiation of SP thymocytes, probably through inhibition of thymic selection.
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Affiliation(s)
- Melanie S Vacchio
- Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, USA.
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16
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Urban JA, Winandy S. Ikaros null mice display defects in T cell selection and CD4 versus CD8 lineage decisions. THE JOURNAL OF IMMUNOLOGY 2004; 173:4470-8. [PMID: 15383578 DOI: 10.4049/jimmunol.173.7.4470] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Previous evidence suggested that the hemopoietic-specific nuclear factor Ikaros regulates TCR signaling thresholds in mature T cells. In this study, we test the hypothesis that Ikaros also sets TCR signaling thresholds to regulate selection events and CD4 vs CD8 lineage determination in developing thymocytes. Ikaros null mice were crossed to three lines of TCR-transgenic mice, and positive selection, negative selection, and CD4 vs CD8 lineage decisions were analyzed. Mice expressing a polyclonal repertoire or a MHC class II-restricted TCR transgene exhibited enhanced positive selection toward the CD4 lineage. Moreover, in the absence of Ikaros, CD4 development can occur with decreased thresholds of TCR signaling. In addition, CD4 single-positive thymocytes were detected in MHC class I-restricted TCR-transgenic Ikaros null mice. To assess the role of Ikaros in negative selection, we analyzed deletion of T cells induced by conventional Ag or by endogenous superantigen. Surprisingly, negative selection was impaired in Ikaros null thymocytes despite evidence of high levels of TCR signal and no intrinsic defect in apoptosis ex vivo. To our knowledge, these data identify Ikaros as the first nuclear factor that plays a critical role in regulating negative selection as well as CD4 vs CD8 lineage decisions during positive selection.
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Affiliation(s)
- Julie A Urban
- Department of Microbiology-Immunology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA
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17
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Lohr J, Knoechel B, Kahn EC, Abbas AK. Role of B7 in T cell tolerance. THE JOURNAL OF IMMUNOLOGY 2004; 173:5028-35. [PMID: 15470046 DOI: 10.4049/jimmunol.173.8.5028] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The induction of effective immune responses requires costimulation by B7 molecules, and Ag recognition without B7 is thought to result in no response or tolerance. We compared T cell responses in vivo to the same Ag presented either by mature dendritic cells (DCs) or as self, in the presence or absence of B7. We show that Ag presentation by mature B7-1/2-deficient DCs fails to elicit an effector T cell response but does not induce tolerance. In contrast, using a newly developed adoptive transfer system, we show that naive OVA-specific DO11 CD4+ T cells become anergic upon encounter with a soluble form of OVA, in the presence or absence of B7. However, tolerance in DO11 cells transferred into soluble OVA transgenic recipients can be broken by immunization with Ag-pulsed DCs only in B7-deficient mice and not in wild-type mice, suggesting a role of B7 in maintaining tolerance in the presence of strong immunogenic signals. Comparing two double-transgenic models--expressing either a soluble or a tissue Ag--we further show that B7 is not only essential for the active induction of regulatory T cells in the thymus, but also for their maintenance in the periphery. Thus, the obligatory role of B7 molecules paradoxically is to promote effective T cell priming and contain effector responses when self-Ags are presented as foreign.
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Affiliation(s)
- Jens Lohr
- Department of Pathology, University of California San Francisco, School of Medicine, 94143, USA
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18
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Zheng X, Gao JX, Chang X, Wang Y, Liu Y, Wen J, Zhang H, Zhang J, Liu Y, Zheng P. B7-CD28 Interaction Promotes Proliferation and Survival but Suppresses Differentiation of CD4−CD8− T Cells in the Thymus. THE JOURNAL OF IMMUNOLOGY 2004; 173:2253-61. [PMID: 15294937 DOI: 10.4049/jimmunol.173.4.2253] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Costimulatory molecules play critical roles in the induction and effector function of T cells. More recent studies reveal that costimulatory molecules enhance clonal deletion of autoreactive T cells as well as generation and homeostasis of the CD25(+)CD4(+) regulatory T cells. However, it is unclear whether the costimulatory molecules play any role in the proliferation and differentiation of T cells before they acquire MHC-restricted TCR. In this study, we report that targeted mutations of B7-1 and B7-2 substantially reduce the proliferation and survival of CD4(-)CD8(-) (double-negative (DN)) T cells in the thymus. Perhaps as a result of reduced proliferation, the accumulation of RAG-2 protein in the DN thymocytes is increased in B7-deficient mice, which may explain the increased expression of TCR gene and accelerated transition of CD25(+)CD44(-) (DN3) to CD25(-)CD44(-) (DN4) stage. Qualitatively similar, but quantitatively less striking effects were observed in mice with a targeted mutation of CD28, but not CTLA4. Taken together, our results demonstrate that the development of DN in the thymus is subject to modulation by the B7-CD28 costimulatory pathway.
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Affiliation(s)
- Xincheng Zheng
- Division of Cancer Immunology, Department of Pathology, Ohio State University Medical Center and Comprehensive Cancer Center, Columbus, OH 43210, USA
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19
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van den Brandt J, Wang D, Reichardt HM. Resistance of single-positive thymocytes to glucocorticoid-induced apoptosis is mediated by CD28 signaling. Mol Endocrinol 2003; 18:687-95. [PMID: 14701943 DOI: 10.1210/me.2003-0390] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Glucocorticoids administered in pharmacological doses potently induce apoptosis in immature double-positive thymocytes. In contrast, single-positive thymocytes are completely resistant. We now provide evidence that this difference can be attributed to CD28 signaling. When taken into culture, single-positive thymocytes also become sensitive to glucocorticoid-induced apoptosis, which can be prevented by enforced CD28 engagement using a novel type of antibody. This is achieved, at least in part, by transcriptional regulation of apoptosis-related genes such as Bcl-X(L) via a calcium- and phosphatidylinositol 3 kinase-dependent pathway. Accordingly, deficiency of CD28 in genetically engineered mice leads to an increased sensitivity of single-positive thymocytes toward glucocorticoid-induced cell death in vivo. Taken together, we have identified CD28 signaling in the thymus as a key player in determining the differential sensitivity of double-positive and single-positive cells to glucocorticoid action.
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Affiliation(s)
- Jens van den Brandt
- Institute of Virology and Immunobiology, University of Würzburg, Versbacher Strasse 7, 97078 Würzburg, Germany
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20
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Abstract
A functional immune system requires the selection of T lymphocytes expressing receptors that are major histocompatibility complex restricted but tolerant to self-antigens. This selection occurs predominantly in the thymus, where lymphocyte precursors first assemble a surface receptor. In this review we summarize the current state of the field regarding the natural ligands and molecular factors required for positive and negative selection and discuss a model for how these disparate outcomes can be signaled via the same receptor. We also discuss emerging data on the selection of regulatory T cells. Such cells require a high-affinity interaction with self-antigens, yet differentiate into regulatory cells instead of being eliminated.
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Affiliation(s)
- Timothy K Starr
- Center for Immunology and the Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis 55455, USA.
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21
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Buhlmann JE, Elkin SK, Sharpe AH. A role for the B7-1/B7-2:CD28/CTLA-4 pathway during negative selection. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:5421-8. [PMID: 12759417 DOI: 10.4049/jimmunol.170.11.5421] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Although costimulation plays an important role in activating naive T cells, its role in negative selection is controversial. By following thymocyte deletion induced by endogenous superantigens in mice lacking B7-1 and/or B7-2, we have identified a role for both B7-1 and B7-2 in negative selection. Studies using CD28-deficient and CD28/CTLA-4-double-deficient mice have revealed that either CD28 or another as yet undefined coreceptor can mediate these B7-dependent signals that promote negative selection. Finally, CTLA-4 delivers signals that inhibit selection, suggesting that CTLA-4 and CD28 have opposing functions in thymic development. Combined, the data demonstrate that B7-1/B7-2-dependent signals help shape the T cell repertoire.
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Affiliation(s)
- Janet E Buhlmann
- Department of Pathology, Immunology Research Division, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
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22
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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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23
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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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24
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Guerin S, Baron ML, Valero R, Herrant M, Auberger P, Naquet P. RelB reduces thymocyte apoptosis and regulates terminal thymocyte maturation. Eur J Immunol 2002; 32:1-9. [PMID: 11753998 DOI: 10.1002/1521-4141(200201)32:1<1::aid-immu1>3.0.co;2-s] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Thymocyte maturation is controlled by successive developmental checkpoints connected to the acquisition of a functional T cell receptor (TCR). During thymocyte selection, engagement of the TCR regulates the fine balance between death and survival signals. At the final stages of single-positive (SP) thymocyte maturation, the coupling of the TCR changes from death- to proliferation-inducing signals, a competence required for optimal effector functions in the periphery. We show here that in RelB mutant thymuses, thymocyte differentiation of CD24(-) SP cells is partially impaired. Competitive bone marrow reconstitution experiments show that this defect is constitutive to the lymphoid compartment. This is accompanied by an increased proportion of apoptotic thymocytes and a drastically reduced proliferation upon activation with anti-CD3 antibody/PMA stimulation. Thus, the RelB protein contributes to the quality of cell signaling in thymocytes by providing anti-apoptotic signals. These results suggest that in addition to its major role on the activation of antigen-presenting cell function, the RelB protein is intrinsically required for terminal thymocyte differentiation and activation.
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Affiliation(s)
- Sandrine Guerin
- Centre d'Immunologie de Marseille-Luminy, CNRS-INSERM-Université de la Méditerranée, Marseille, France
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25
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Mora AL, Stanley S, Armistead W, Chan AC, Boothby M. Inefficient ZAP-70 phosphorylation and decreased thymic selection in vivo result from inhibition of NF-kappaB/Rel. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:5628-35. [PMID: 11698434 DOI: 10.4049/jimmunol.167.10.5628] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Signaling from the TCR regulates T lymphoid survival, deletion by apoptosis, and selective clonal expansion. One set of signaling pathways activated during thymic selection leads to degradation of a cytosolic retention protein, the inhibitor of kappaB (IkappaB)alpha, followed by nuclear translocation of the NF-kappaB/Rel family of transcription factors. It has been found previously that NF-kappaB proteins mediate a pathway signaling the survival of mature T cells and protection of thymocytes against TNF-induced apoptosis. In contrast, we show in this study that a transgenic inhibitor of NF-kappaB/Rel signaling interferes with the negative selection of immature thymocytes by endogenous MHC ligands in vivo. Positive selection of the H-Y TCR also was diminished. This attenuation of thymic selection efficiency was associated with decreased ZAP-70 phosphorylation and TCR signaling of CD69 induction. These findings demonstrate that the NF-kappaB transcriptional pathway plays an important role in normal processes of clonal deletion and they indicate that the NF-kappaB/IkappaB axis can regulate the efficiency of TCR signaling.
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Affiliation(s)
- A L Mora
- Department of Microbiology and Immunology, Vanderbilt University Medical School, Nashville, TN 37232, USA
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26
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Travers H, Anderson G, Gentle D, Jenkinson E, Girdlestone J. Protocols for high efficiency, stage-specific retroviral transduction of murine fetal thymocytes and thymic epithelial cells. J Immunol Methods 2001; 253:209-22. [PMID: 11384682 DOI: 10.1016/s0022-1759(01)00391-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: 10/18/2022]
Abstract
Viral vectors have the potential to provide a fast and economic alternative to transgenic methods for manipulating gene expression in studies of immune system development and function. Although protocols exist for the infection of hematopoietic precursors and peripheral T cells in vitro, critical stages of T cell differentiation are strictly dependent upon a three-dimensional thymic architecture and their analysis poses unique technical challenges. Whole fetal thymic lobes have been used as targets for retroviral and adenoviral infection, both in situ and in vitro, but this approach does not allow for discrimination between lymphoid and stromal components. Isolated thymocytes have been infected by co-culture with viral producer cells, but under these conditions they rapidly lose their developmental potential. To overcome these problems we have combined a number of efficient techniques for retroviral production, concentration, and infection that allow us to rapidly achieve significant transduction rates of purified populations of double-negative (DN) and double-positive (DP) thymocytes, single-positive (SP) T lymphocytes, as well as fetal thymic MHC II(+) epithelial cells without the need for co-culture with viral producer cells. Reaggregate thymic organ culture (RTOC) techniques were used to assess the development and function of transduced cells in defined cellular environments. As a demonstration of the utility of these methods, CD80 (B7.1) was transduced into thymic epithelial cells and shown to allow them to mediate negative selection of DP thymocytes, and to act as antigen-presenting cells (APC) to mature T cells. The ability to genetically manipulate primary cells of a specified type and differentiation stage provides a powerful complement to RTOC techniques for the study of T cell development.
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Affiliation(s)
- H Travers
- Anatomy Department, Division of Immunity and Infection, MRC Centre for Immune Regulation, The Medical School, University of Birmingham, B15 2TT, Birmingham, UK.
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27
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Annunziato F, Romagnani P, Cosmi L, Lazzeri E, Romagnani S. Chemokines and lymphopoiesis in human thymus. Trends Immunol 2001; 22:277-81. [PMID: 11323287 DOI: 10.1016/s1471-4906(01)01889-0] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Distinct and redundant chemokines are responsible for organizing the extraordinarily diverse thymocyte populations into discrete microenvironments, from the arrival of immature precursors in the thymus to the migration of different mature cell types to the periphery. We propose that, by selectively mobilizing cells, chemokines can sort positively selected cells from negatively selected cells, and that chemokines make distinctions among CD8+ subpopulations that previously have not been recognized.
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Affiliation(s)
- F Annunziato
- Dept of Internal Medicine, Section of Immunoallergology and Respiratory Diseases, University of Florence, Viale Pieraccini 6, Florence-50134, Italy
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28
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Szot GL, Zhou P, Rulifson I, Wang J, Guo Z, Kim O, Newel KA, Thistlethwaite JR, Bluestone JA, Alegre ML. Different mechanisms of cardiac allograft rejection in wildtype and CD28-deficient mice. Am J Transplant 2001; 1:38-46. [PMID: 12095035 DOI: 10.1034/j.1600-6143.2001.010108.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Although CD28 blockade results in long-term cardiac allograft survival in wildtype mice, CD28-deficient mice effectively reject heart allografts. This study compared the mechanisms of allogeneic responses in wildtype and CD28-deficient mice. Adoptive transfer of purified CD28-deficient T cells into transplanted nude mice resulted in graft rejection. However, this model demonstrated that the allogeneic T cell function was severely impaired when compared with wildtype T cells, despite similar survival kinetics. Cardiac allograft rejection depended on both CD4+ and CD8+ T cell subsets in CD28-deficient mice, whereas only CD4+ T cells were necessary in wildtype recipients. These results suggested that CD8+ T cells were more important in CD28-deficient than wildtype mice. In addition to the CD8+ T cell requirement, allograft rejection in CD28-deficient mice was dependent on a sustained presence of CD4+ T cells, whereas it only required the initial presence of CD4+ T cells in wildtype mice. Taken together, these data suggest that CD4+ T cells from CD28-deficient mice have impaired responses to alloantigen in vivo, thus requiring long-lasting cooperation with CD8+ T cell responses to facilitate graft rejection. These results may help to explain the failure to promote graft tolerance in some preclinical and clinical settings.
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Affiliation(s)
- G L Szot
- Ben May Institute for Cancer Research, The University of Chicago, IL 60637, USA
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29
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Abstract
Combinatorial regulation is a powerful mechanism that enables tight control of gene expression, via integration of multiple signaling pathways that induce different transcription factors required for enhanceosome assembly. The four calcium-regulated transcription factors of the NFAT family act synergistically with AP-1 (Fos/Jun) proteins on composite DNA elements which contain adjacent NFAT and AP-1 binding sites, where they form highly stable ternary complexes to regulate the expression of diverse inducible genes. Concomitant induction of NFAT and AP-1 requires concerted activation of two different signaling pathways: calcium/calcineurin, which promotes NFAT dephosphorylation, nuclear translocation and activation; and protein kinase C (PKC)/Ras, which promotes the synthesis, phosphorylation and activation of members of the Fos and Jun families of transcription factors. A fifth member of the NFAT family, NFAT5, controls the cellular response to osmotic stress, by a mechanism that requires dimer formation and is independent of calcineurin or of interaction with AP-1. Pharmacological interference with theNFAT:AP-1 interaction may be useful in selective manipulation of the immune response. Balanced activation of NFAT and AP-1 is known to be required for productive immune responses, but the role of NFAT:AP-1 interactions in other cell types and biological processes remains to be understood.
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Affiliation(s)
- F Macián
- Department of Pathology, Harvard Medical School and the Center for Blood Research, 200 Longwood Avenue, Boston, Massachusetts, MA 02115, USA
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30
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Bergman ML, Cilio CM, Penha-Gonçalves C, Lamhamedi-Cherradi SE, Löfgren A, Colucci F, Lejon K, Garchon HJ, Holmberg D. CTLA-4-/- mice display T cell-apoptosis resistance resembling that ascribed to autoimmune-prone non-obese diabetic (NOD) mice. J Autoimmun 2001; 16:105-13. [PMID: 11247636 DOI: 10.1006/jaut.2000.0474] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The genes conferring susceptibility to autoimmune (insulin-dependent) diabetes mellitus (IDDM) are, in most cases, not defined. Among the loci so far identified as associated with murine IDDM (Idd1-19), only the nature of Idd1 has been assessed. Here we show that thymocytes and peripheral lymphocytes of the non-obese diabetic (NOD) mouse are relatively resistant to apoptosis induced by gamma-irradiation. By linkage analysis of F2 progeny mice, we map this trait to a locus on chromosome 1 containing the Idd5 diabetes susceptibility region. By the use of congenic mice, we confirm the linkage data and map this locus to a 6 cM region on proximal chromosome 1. Ctla4, being localized in this chromosomal region and mediating crucial functions in T cell biology, is a logical candidate gene in the Idd5 susceptibility region. In line with this, we demonstrate that T cells from Ctla4(-/-)deficient mice show a similar resistance to gamma-irradiation-induced apoptosis as observed in the NOD mice. This reinforces the notion that CTLA-4 contributes to the pathogenesis of autoimmune diabetes.
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Affiliation(s)
- M L Bergman
- Department of Cell and Molecular Biology, University of Umeå, S-901 87 Umeå Sweden
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31
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Teh HS, Teh SJ. The affinity/avidity and length of exposure to the deleting ligand determine dependence on CD28 for the efficient deletion of self-specific CD4+CD8+ thymocytes. Cell Immunol 2001; 207:100-9. [PMID: 11243699 DOI: 10.1006/cimm.2000.1757] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Whether the CD28/B7 signaling pathway is essential for the negative selection of immature CD4+CD8+ (DP) thymocytes expressing self-specific alphabeta TCRs is a controversial issue. In this study we examined the role of CD28 in the deletion of thymocytes that express either the H-Y or the 2C transgenic TCR. In H-2(b) male mice that expressed the H-Y TCR, negative selection of DP H-Y TCR+ thymocytes occurred very efficiently and this deletion was unaffected by the CD28(-/-) mutation. In H-2(b) 2C mice, where the deletion of DP 2C TCR+ thymocytes occurred less efficiently, the CD28(-/-) mutation led to a higher recovery of DP thymocytes. Using an in vitro deletion assay, a requirement for the CD28 signaling pathway in the deletion of DP H-Y TCR+ thymocytes was evident at low, but not high, densities of the antigenic ligand. Similar results were also observed in an in vivo assay for the deletion of these thymocytes. Intraperitoneal administration of an anti-CD3epsilon mAb led to the intrathymic deletion of DP H-Y TCR+ thymocytes in a CD28-dependent manner at the 24-h time point. However, the CD28 dependence was less evident at the 40-h time point. These results indicate that the dependence on CD28 for the efficient deletion of self-specific thymocytes is determined by the concentration, affinity/avidity, and length of exposure to the deleting ligand.
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Affiliation(s)
- H S Teh
- The Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
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32
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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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33
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Macián F, García-Rodríguez C, Rao A. Gene expression elicited by NFAT in the presence or absence of cooperative recruitment of Fos and Jun. EMBO J 2000; 19:4783-95. [PMID: 10970869 PMCID: PMC302068 DOI: 10.1093/emboj/19.17.4783] [Citation(s) in RCA: 240] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Cooperation between nuclear factor of activated T cells (NFAT) and AP-1 (Fos-Jun) proteins on composite NFAT-AP-1 DNA elements constitutes a powerful mechanism for signal integration of the calcium and protein kinase C/Ras pathways in the regulation of gene expression. Here we report that NFAT can induce expression of certain genes in T cells without the need for cooperative recruitment of Fos and Jun. Using NFAT1 mutant proteins that are unable to interact with Fos-Jun dimers but are unaffected in DNA binding or transcriptional activity, we show that expression of interleukin (IL)-2, granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-3, IL-4, MIP1alpha and Fas ligand mRNAs is absolutely dependent on cooperation between NFAT and Fos-Jun; in contrast, NFAT induces tumor necrosis factor alpha (TNFalpha) mRNA and IL-13 promoter activity without any necessity to recruit Fos and Jun. Furthermore, we show that NFAT-Fos-Jun cooperation is also essential to elicit the NFAT-dependent program of activation-induced cell death. Our results support the hypothesis that even in a single cell type, NFAT activation can evoke two distinct biological programs of gene expression, dependent or independent of NFAT-AP-1 cooperation.
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Affiliation(s)
- F Macián
- Department of Pathology, Harvard Medical School and the Center for Blood Research, 200 Longwood Avenue, Boston, MA 02115, USA
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34
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Yu X, Fournier S, Allison JP, Sharpe AH, Hodes RJ. The role of B7 costimulation in CD4/CD8 T cell homeostasis. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 164:3543-53. [PMID: 10725709 DOI: 10.4049/jimmunol.164.7.3543] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The effect of B7-mediated costimulation on T cell homeostasis was examined in studies of B7-1 (CD80) and B7-2 (CD86) transgenic as well as B7-deficient mice. B7 overexpression in transgenic mice resulted in marked polyclonal peripheral T cell hyperplasia accompanied by skewing toward an increased proportion of CD8 single-positive cells and a decreased proportion of CD4 single-positive cells in thymus and more markedly in peripheral T cells. B7-induced T cell expansion was dependent on both CD28 and TCR expression. Transgenic overexpression of B7-1 or B7-2 resulted in down-regulation of cell surface CD28 on thymocytes and peripheral T cells through a mechanism mediated by intercellular interaction. Mice deficient in B7-1 and B7-2 exhibited changes that were the reciprocal of those observed in B7-overexpressing transgenics: a marked increase in the CD4/CD8 ratio in peripheral T cells and an increase in cell surface CD28 in thymus and peripheral T cells. These reciprocal effects of genetically engineered increase or decrease in B7 expression indicate that B7 costimulation plays a physiological role in the regulation of CD4+ and CD8+ T cell homeostasis.
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MESH Headings
- Abatacept
- Animals
- Antigens, CD/biosynthesis
- Antigens, CD/genetics
- Antigens, CD/physiology
- Antigens, Differentiation/biosynthesis
- Antigens, Differentiation/genetics
- B7-1 Antigen/biosynthesis
- B7-1 Antigen/genetics
- B7-1 Antigen/physiology
- B7-2 Antigen
- CD28 Antigens/biosynthesis
- CD28 Antigens/genetics
- CD28 Antigens/physiology
- CD4-CD8 Ratio
- CD4-Positive T-Lymphocytes/cytology
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/metabolism
- CD8-Positive T-Lymphocytes/cytology
- CD8-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/metabolism
- CTLA-4 Antigen
- Down-Regulation/genetics
- Down-Regulation/immunology
- Homeostasis/genetics
- Homeostasis/immunology
- Hyperplasia
- Immunoconjugates
- Lymphocyte Activation/genetics
- Lymphoid Tissue/immunology
- Lymphoid Tissue/metabolism
- Lymphoid Tissue/pathology
- Membrane Glycoproteins/biosynthesis
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/physiology
- Mice
- Mice, Congenic
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Mutant Strains
- Mice, Transgenic
- Phenotype
- Receptors, Antigen, T-Cell/biosynthesis
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell, alpha-beta/biosynthesis
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
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Affiliation(s)
- X Yu
- Experimental Immunology Branch, National Cancer Institute, and National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA.
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35
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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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36
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Kishimoto H, Sprent J. Several different cell surface molecules control negative selection of medullary thymocytes. J Exp Med 1999; 190:65-73. [PMID: 10429671 PMCID: PMC2195556 DOI: 10.1084/jem.190.1.65] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/1999] [Accepted: 05/10/1999] [Indexed: 12/15/2022] Open
Abstract
Repeated attempts to show that costimulation for negative selection is controlled by a single cell surface molecule have been unsuccessful. Thus, negative selection may involve multiple cell surface molecules acting in consort. In support of this idea, we show here that at least three cell surface molecules, namely CD28, CD5, and CD43, contribute to Fas-independent negative selection of the tolerance-susceptible population of heat-stable antigen (HSA)hiCD4+8- cells found in the medulla. The costimulatory function of these three molecules can be blocked by certain cytokines, IL-4 and IL-7, and coinjecting these cytokines with antigen in vivo abolishes negative selection; Fas-dependent negative selection, however, is maintained. The results suggest that efficient negative selection requires the combined functions of at least four cell surface molecules: CD28, CD5, CD43, and Fas.
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Affiliation(s)
- H Kishimoto
- Department of Immunology, Scripps Research Institute, La Jolla, California 92037, USA
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Burns RP, Nasir A, Haake AR, Barth RK, Gaspari AA. B7-1 overexpression by thymic epithelial cells results in transient and long-lasting effects on thymocytes and peripheral T helper cells but does not result in immunodeficiency. Cell Immunol 1999; 194:162-77. [PMID: 10383819 DOI: 10.1006/cimm.1999.1510] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The B7-1 (CD80) molecule provides costimulatory function for the activation of T helper lymphocytes upon encounter with antigen. To investigate the role of this molecule in thymocyte maturation, we have generated transgenic (Tg) mice in which CD80 expression is driven by the keratin 14 promoter (K14). This overexpression of CD80 resulted in the loss of detectable cell surface CD28 expression on thymocytes and a significant reduction in both the surface T cell receptor expression and the ratio of CD4(+) to CD8(+) single-positive thymocytes in Tg animals compared to nontransgenic (non-Tg) controls. While many of these defects were transient, the significant decrease in CD4(+) versus CD8(+) T cell ratio persisted peripherally. Peripheral T cells from these Tg mice were found to be significantly hyporesponsive to T cell mitogens and in mixed leukocyte reaction, effects that our data indicate are due to reduced IL-2 production by Tg T cells upon activation. Despite these functional defects, immunization with both complex and simple protein antigens produced no differences in the proliferative or humoral responses to these antigens between Tg and non-Tg groups. These data indicate that thymic CD80 signaling results in the deletion of significant numbers of CD4(+) T cells but does not culminate in antigen-specific immunodeficiency.
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Affiliation(s)
- R P Burns
- Department of Dermatology, University of Rochester School of Medicine and Dentistry, Rochester, New York, 14642, USA
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38
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Moore JK, Gold DP, Dreskin SC, Lernmark A, Bellgrau D. A diabetogenic gene prevents T cells from receiving costimulatory signals. Cell Immunol 1999; 194:90-7. [PMID: 10357884 DOI: 10.1006/cimm.1999.1501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
T cell fate following antigen encounter is determined by several intracellular signals generated by the interaction of the T cell with an antigen-presenting cell. In the periphery activation requires T cell receptor signaling (signal one) in combination with costimulatory signals (signal two), usually provided through the cognate interaction of CD28 and B7 molecules. Provision of signal one alone to purified murine peripheral T cells in vitro induces apoptosis or anergy rather than promoting activation. These T cells can be rescued from apoptosis if they are provided with costimulation supplied, for example, by engaging the CD28 co-receptor with an anti-CD28 monoclonal antibody or by adding an exogenous source of interleukin-2. However, a majority of peripheral T cells from autoimmune, diabetes-prone Biobreeding (BB) rats exhibited different responses to these stimuli. T cells from these rats could not be rescued from apoptosis by costimulation. This was not due to the inability of BB-DP T cells to upregulate CD28 and the IL-2 receptor in response to TCR crosslinking. The failure of these costimulatory interactions to rescue BB-DP T cells segregated with the diabetes-susceptibility gene iddm1. Iddm1 in the rat causes peripheral T cell lymphopenia, which is associated with a dramatically shortened peripheral T cell life span. Our results indicate that a diabetogenic gene may contribute to autoimmunity by negating costimulatory signals important for the survival of long-lived peripheral T cells.
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Affiliation(s)
- J K Moore
- Department of Immunology, Department of Medicine, University of Colorado Health Sciences Center, 4200 E. Ninth Avenue, Denver, Colorado, 80262, USA
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Amsen D, Revilla Calvo C, Osborne BA, Kruisbeek AM. Costimulatory signals are required for induction of transcription factor Nur77 during negative selection of CD4(+)CD8(+) thymocytes. Proc Natl Acad Sci U S A 1999; 96:622-7. [PMID: 9892683 PMCID: PMC15186 DOI: 10.1073/pnas.96.2.622] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A major question in end-stage T cell development is how T cell receptor(TCR) ligation on immature CD4(+)CD8(+) double positive thymocytes is translated into either survival (positive selection) or apoptotic (negative selection) signals. Because different types of antigen-presenting cells (APCs) induce positive or negative selection in the thymus and express different costimulatory molecules, involvement of such costimulatory molecules in determining cell fate of DP thymocytes is considered here. If TCR-generated signals are modulated by APCs, this should be reflected in the activation of distinct biochemical pathways. We here demonstrate that costimulatory signals involved in negative selection also are required for induction of protein expression of Nur77 and its family members. These transcription factors are critically involved in negative but not positive selection. In contrast, the signals that costimulate negative selection are not required for induction of several molecular events associated with positive selection. These include activation of the immediate early gene Egr-1, the mitogen-activated protein kinase ERK2, and surface expression of the CD69 marker. Thus, costimulation for negative selection selectively provides signals for activation of apoptotic mediators. These data provide molecular insights into how TCR-engagement by ligands on different thymic APCs can determine cell fate.
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Affiliation(s)
- D Amsen
- Division of Immunology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
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