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Breed ER, Vobořil M, Ashby KM, Martinez RJ, Qian L, Wang H, Salgado OC, O'Connor CH, Hogquist KA. Type 2 cytokines in the thymus activate Sirpα + dendritic cells to promote clonal deletion. Nat Immunol 2022; 23:1042-1051. [PMID: 35637352 PMCID: PMC10037932 DOI: 10.1038/s41590-022-01218-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 04/18/2022] [Indexed: 12/30/2022]
Abstract
The thymus contains a diversity of dendritic cells (DCs) that exist in defined locations and have different antigen-processing and -presenting features. This suggests that they play nonredundant roles in mediating thymocyte selection. In an effort to eliminate SIRPα+ classic DC2 subsets, we discovered that a substantial proportion expresses the surface lectin, CD301b, in the thymus. These cells resemble the CD301b+ type 2 immune response promoting DCs that are present in the skin-draining lymph nodes. Transcriptional and phenotypic comparison to other DC subsets in the thymus revealed that thymic CD301b+ cDCs represent an activated state that exhibits enhanced antigen processing and presentation. Furthermore, a CD301b+ cDC2 subset demonstrated a type 2 cytokine signature and required steady-state interleukin-4 receptor signaling. Selective ablation of CD301b+ cDC2 subsets impaired clonal deletion without affecting regulatory T cells (Treg cells). The T cell receptor α repertoire sequencing confirmed that a cDC2 subset promotes deletion of conventional T cells with minimal effect on Treg cell selection. Together, these findings suggest that cytokine-induced activation of DCs in the thymus substantially enforces central tolerance.
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Affiliation(s)
- Elise R Breed
- Department of Laboratory Medicine and Pathology, Center for Immunology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Matouš Vobořil
- Department of Laboratory Medicine and Pathology, Center for Immunology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Katherine M Ashby
- Department of Laboratory Medicine and Pathology, Center for Immunology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Ryan J Martinez
- Department of Laboratory Medicine and Pathology, Center for Immunology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Lily Qian
- Department of Laboratory Medicine and Pathology, Center for Immunology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Haiguang Wang
- Department of Laboratory Medicine and Pathology, Center for Immunology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Oscar C Salgado
- Department of Laboratory Medicine and Pathology, Center for Immunology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Christine H O'Connor
- Research Informatics Solutions, Laboratory Medicine and Pathology Group, Minnesota Supercomputing Institute, Minneapolis, MN, USA
| | - Kristin A Hogquist
- Department of Laboratory Medicine and Pathology, Center for Immunology, University of Minnesota Medical School, Minneapolis, MN, USA.
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2
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Huseby ES, Teixeiro E. The perception and response of T cells to a changing environment are based on the law of initial value. Sci Signal 2022; 15:eabj9842. [PMID: 35639856 PMCID: PMC9290192 DOI: 10.1126/scisignal.abj9842] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
αβ T cells are critical components of the adaptive immune system and are capable of inducing sterilizing immunity after pathogen infection and eliminating transformed tumor cells. The development and function of T cells are controlled through the T cell antigen receptor, which recognizes peptides displayed on major histocompatibility complex (MHC) molecules. Here, we review how T cells generate the ability to recognize self-peptide-bound MHC molecules and use signals derived from these interactions to instruct cellular development, activation thresholds, and functional specialization in the steady state and during immune responses. We argue that the basic tenants of T cell development and function follow Weber-Fetcher's law of just noticeable differences and Wilder's law of initial value. Together, these laws argue that the ability of a system to respond and the quality of that response are scalable to the basal state of that system. Manifestation of these laws in T cells generates clone-specific activation thresholds that are based on perceivable differences between homeostasis and pathogen encounter (self versus nonself discrimination), as well as poised states for subsequent differentiation into specific effector cell lineages.
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Affiliation(s)
- Eric S. Huseby
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Emma Teixeiro
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO 65212, USA
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3
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Gangopadhyay K, Roy S, Sen Gupta S, Chandradasan A, Chowdhury S, Das R. Regulating the discriminatory response to antigen by T-cell receptor. Biosci Rep 2022; 42:BSR20212012. [PMID: 35260878 PMCID: PMC8965820 DOI: 10.1042/bsr20212012] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 03/04/2022] [Accepted: 03/08/2022] [Indexed: 11/17/2022] Open
Abstract
The cell-mediated immune response constitutes a robust host defense mechanism to eliminate pathogens and oncogenic cells. T cells play a central role in such a defense mechanism and creating memories to prevent any potential infection. T cell recognizes foreign antigen by its surface receptors when presented through antigen-presenting cells (APCs) and calibrates its cellular response by a network of intracellular signaling events. Activation of T-cell receptor (TCR) leads to changes in gene expression and metabolic networks regulating cell development, proliferation, and migration. TCR does not possess any catalytic activity, and the signaling initiates with the colocalization of several enzymes and scaffold proteins. Deregulation of T cell signaling is often linked to autoimmune disorders like severe combined immunodeficiency (SCID), rheumatoid arthritis, and multiple sclerosis. The TCR remarkably distinguishes the minor difference between self and non-self antigen through a kinetic proofreading mechanism. The output of TCR signaling is determined by the half-life of the receptor antigen complex and the time taken to recruit and activate the downstream enzymes. A longer half-life of a non-self antigen receptor complex could initiate downstream signaling by activating associated enzymes. Whereas, the short-lived, self-peptide receptor complex disassembles before the downstream enzymes are activated. Activation of TCR rewires the cellular metabolic response to aerobic glycolysis from oxidative phosphorylation. How does the early event in the TCR signaling cross-talk with the cellular metabolism is an open question. In this review, we have discussed the recent developments in understanding the regulation of TCR signaling, and then we reviewed the emerging role of metabolism in regulating T cell function.
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Affiliation(s)
- Kaustav Gangopadhyay
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur campus, Mohanpur 741246, India
| | - Swarnendu Roy
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur campus, Mohanpur 741246, India
| | - Soumee Sen Gupta
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur campus, Mohanpur 741246, India
| | - Athira C. Chandradasan
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur campus, Mohanpur 741246, India
| | - Subhankar Chowdhury
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur campus, Mohanpur 741246, India
| | - Rahul Das
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur campus, Mohanpur 741246, India
- Centre for Advanced Functional Materials, Indian Institute of Science Education and Research Kolkata, Mohanpur campus, Mohanpur 741246, India
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4
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Modeling the Dynamics of T-Cell Development in the Thymus. ENTROPY 2021; 23:e23040437. [PMID: 33918050 PMCID: PMC8069328 DOI: 10.3390/e23040437] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 04/01/2021] [Accepted: 04/05/2021] [Indexed: 12/24/2022]
Abstract
The thymus hosts the development of a specific type of adaptive immune cells called T cells. T cells orchestrate the adaptive immune response through recognition of antigen by the highly variable T-cell receptor (TCR). T-cell development is a tightly coordinated process comprising lineage commitment, somatic recombination of Tcr gene loci and selection for functional, but non-self-reactive TCRs, all interspersed with massive proliferation and cell death. Thus, the thymus produces a pool of T cells throughout life capable of responding to virtually any exogenous attack while preserving the body through self-tolerance. The thymus has been of considerable interest to both immunologists and theoretical biologists due to its multi-scale quantitative properties, bridging molecular binding, population dynamics and polyclonal repertoire specificity. Here, we review experimental strategies aimed at revealing quantitative and dynamic properties of T-cell development and how they have been implemented in mathematical modeling strategies that were reported to help understand the flexible dynamics of the highly dividing and dying thymic cell populations. Furthermore, we summarize the current challenges to estimating in vivo cellular dynamics and to reaching a next-generation multi-scale picture of T-cell development.
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5
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Affiliation(s)
- Jeffrey A Bluestone
- From the Sean N. Parker Autoimmune Research Laboratory (J.A.B.) and the Diabetes Center (J.A.B., M.A.), University of California, San Francisco, San Francisco
| | - Mark Anderson
- From the Sean N. Parker Autoimmune Research Laboratory (J.A.B.) and the Diabetes Center (J.A.B., M.A.), University of California, San Francisco, San Francisco
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6
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Huo J, Xu S, Lam KP. FAIM: An Antagonist of Fas-Killing and Beyond. Cells 2019; 8:cells8060541. [PMID: 31167518 PMCID: PMC6628066 DOI: 10.3390/cells8060541] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 05/29/2019] [Accepted: 05/30/2019] [Indexed: 12/12/2022] Open
Abstract
Fas Apoptosis Inhibitory Molecule (FAIM) is an anti-apoptotic protein that is up-regulated in B cell receptor (BCR)-activated B cells and confers upon them resistance to Fas-mediated cell death. Faim has two alternatively spliced isoforms, with the short isoform ubiquitously expressed in various tissues and the long isoform mainly found in the nervous tissues. FAIM is evolutionarily conserved but does not share any significant primary sequence homology with any known protein. The function of FAIM has been extensively studied in the past 20 years, with its primary role being ascribed to be anti-apoptotic. In addition, several other functions of FAIM were also discovered in different physiological and pathological conditions, such as cell growth, metabolism, Alzheimer’s disease and tumorigenesis. However, the detailed molecular mechanisms underlying FAIM’s role in these conditions remain unknown. In this review, we summarize comprehensively the functions of FAIM in these different contexts and discuss its potential as a diagnostic, prognostic or therapeutic target.
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Affiliation(s)
- Jianxin Huo
- Bioprocessing Technology Institute, Agency for Science, Technology and Research, Singapore 138668, Singapore.
| | - Shengli Xu
- Bioprocessing Technology Institute, Agency for Science, Technology and Research, Singapore 138668, Singapore.
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117593, Singapore.
| | - Kong-Peng Lam
- Bioprocessing Technology Institute, Agency for Science, Technology and Research, Singapore 138668, Singapore.
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545, Singapore.
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore.
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7
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Deletion of self-reactive CCR7- thymocytes in the absence of MHC expression on thymic epithelial cells. Cell Death Differ 2019; 26:2727-2739. [PMID: 31019259 DOI: 10.1038/s41418-019-0331-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 03/18/2019] [Accepted: 04/05/2019] [Indexed: 12/11/2022] Open
Abstract
The selection of αβ T cells in the thymus is punctuated by checkpoints at which thymocytes differentiate or undergo apoptosis. Wave 1 deletion is defined as apoptosis within nascent αβ T-cell antigen receptor (TCR)-signalled thymocytes that lack CCR7 expression. The antigen-presenting cell (APC) types that mediate wave 1 deletion are unclear. To measure wave 1 deletion, we compared the frequencies of TCRβ + CD5 + Helios + CCR7- cells in nascent thymocyte cohorts in mice with normal or defective apoptosis. This thymocyte population is small in mice lacking major histocompatibility complex (MHC) expression. The scale of wave 1 deletion was increased by transgenic expression of the self-reactive Yae62 TCRβ chain, was almost halved when haemopoietic APCs lacked MHC expression and, surprisingly, was unchanged when epithelial cells lacked MHC expression. These findings demonstrate efficiency, and some redundancy, in the APC types that mediate wave 1 deletion in the normal mouse thymus.
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8
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Breed ER, Watanabe M, Hogquist KA. Measuring Thymic Clonal Deletion at the Population Level. THE JOURNAL OF IMMUNOLOGY 2019; 202:3226-3233. [PMID: 31010850 DOI: 10.4049/jimmunol.1900191] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 03/25/2019] [Indexed: 12/18/2022]
Abstract
Clonal deletion of T cells specific for self-antigens in the thymus has been widely studied, primarily by approaches that focus on a single receptor (using TCR transgenes) or a single specificity (using peptide-MHC tetramers). However, less is known about clonal deletion at the population level. In this article, we report an assay that measures cleaved caspase 3 to define clonal deletion at the population level. This assay distinguishes clonal deletion from apoptotic events caused by neglect and approximates the anatomic site of deletion using CCR7. This approach showed that 78% of clonal deletion events occur in the cortex in mice. Medullary deletion events were detected at both the semimature and mature stages, although mature events were associated with failed regulatory T cell induction. Using this assay, we showed that bone marrow-derived APC drive approximately half of deletion events at both stages. We also found that both cortical and medullary deletion rely heavily on CD28 costimulation. These findings demonstrate a useful strategy for studying clonal deletion within the polyclonal repertoire.
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Affiliation(s)
- Elise R Breed
- Department of Laboratory Medicine and Pathology, Center for Immunology, University of Minnesota Medical School, Minneapolis, MN 55455; and
| | - Masashi Watanabe
- Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Kristin A Hogquist
- Department of Laboratory Medicine and Pathology, Center for Immunology, University of Minnesota Medical School, Minneapolis, MN 55455; and
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10
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Robinson KA, Orent W, Madsen JC, Benichou G. Maintaining T cell tolerance of alloantigens: Lessons from animal studies. Am J Transplant 2018; 18:1843-1856. [PMID: 29939471 PMCID: PMC6352985 DOI: 10.1111/ajt.14984] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 06/13/2018] [Accepted: 06/14/2018] [Indexed: 01/25/2023]
Abstract
Achieving host immune tolerance of allogeneic transplants represents the ultimate challenge in clinical transplantation. It has become clear that different cells and mechanisms participate in acquisition versus maintenance of allograft tolerance. Indeed, manipulations which prevent tolerance induction often fail to abrogate tolerance once it has been established. Hence, elucidation of the immunological mechanisms underlying maintenance of T cell tolerance to alloantigens is essential for the development of novel interventions that preserve a robust and long lasting state of allograft tolerance that relies on T cell deletion in addition to intra-graft suppression of inflammatory immune responses. In this review, we discuss some essential elements of the mechanisms involved in the maintenance of naturally occurring or experimentally induced allograft tolerance, including the newly described role of antigen cross-dressing mediated by extracellular vesicles.
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Affiliation(s)
- Kortney A. Robinson
- Center for Transplant Sciences, Massachusetts General
Hospital and Harvard Medical School, Boston, MA
| | - William Orent
- Center for Transplant Sciences, Massachusetts General
Hospital and Harvard Medical School, Boston, MA
| | - Joren C. Madsen
- Center for Transplant Sciences, Massachusetts General
Hospital and Harvard Medical School, Boston, MA.,Division of Cardiac Surgery, Department of Surgery,
Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Gilles Benichou
- Center for Transplant Sciences, Massachusetts General
Hospital and Harvard Medical School, Boston, MA
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11
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James KD, Jenkinson WE, Anderson G. T-cell egress from the thymus: Should I stay or should I go? J Leukoc Biol 2018; 104:275-284. [PMID: 29485734 PMCID: PMC6174998 DOI: 10.1002/jlb.1mr1217-496r] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 01/11/2018] [Accepted: 01/22/2018] [Indexed: 02/02/2023] Open
Abstract
T‐cells bearing the αβTCR play a vital role in defending the host against foreign pathogens and malignant transformation of self. Importantly, T‐cells are required to remain tolerant to the host's own cells and tissues in order to prevent self‐reactive responses that can lead to autoimmune disease. T‐cells achieve the capacity for self/nonself discrimination by undergoing a highly selective and rigorous developmental program during their maturation in the thymus. This organ is unique in its ability to support a program of T‐cell development that ensures the establishment of a functionally diverse αβTCR repertoire within the peripheral T‐cell pool. The thymus achieves this by virtue of specialized stromal microenvironments that contain heterogeneous cell types, whose organization and function underpins their ability to educate, support, and screen different thymocyte subsets through various stages of development. These stages range from the entry of early T‐cell progenitors into the thymus, through to the positive and negative selection of the αβTCR repertoire. The importance of the thymus medulla as a site for T‐cell tolerance and the exit of newly generated T‐cells into the periphery is well established. In this review, we summarize current knowledge on the developmental pathways that take place during αβT‐cell development in the thymus. In addition, we focus on the mechanisms that regulate thymic egress and contribute to the seeding of peripheral tissues with newly selected self‐tolerant αβT‐cells. Review on thymic microenvironments regulation of thymocyte maturation and egress of mature self‐tolerant T cells.
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Affiliation(s)
- Kieran D James
- Institute of Immunology and Immunotherapy, College of Medical and Dental Sciences, Medical School, University of Birmingham, Birmingham, UK
| | - William E Jenkinson
- Institute of Immunology and Immunotherapy, College of Medical and Dental Sciences, Medical School, University of Birmingham, Birmingham, UK
| | - Graham Anderson
- Institute of Immunology and Immunotherapy, College of Medical and Dental Sciences, Medical School, University of Birmingham, Birmingham, UK
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12
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Audiger C, Rahman MJ, Yun TJ, Tarbell KV, Lesage S. The Importance of Dendritic Cells in Maintaining Immune Tolerance. THE JOURNAL OF IMMUNOLOGY 2017; 198:2223-2231. [PMID: 28264998 DOI: 10.4049/jimmunol.1601629] [Citation(s) in RCA: 189] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 12/11/2016] [Indexed: 12/30/2022]
Abstract
Immune tolerance is necessary to prevent the immune system from reacting against self, and thus to avoid the development of autoimmune diseases. In this review, we discuss key findings that position dendritic cells (DCs) as critical modulators of both thymic and peripheral immune tolerance. Although DCs are important for inducing both immunity and tolerance, increased autoimmunity associated with decreased DCs suggests their nonredundant role in tolerance induction. DC-mediated T cell immune tolerance is an active process that is influenced by genetic variants, environmental signals, as well as the nature of the specific DC subset presenting Ag to T cells. Answering the many open questions with regard to the role of DCs in immune tolerance could lead to the development of novel therapies for the prevention of autoimmune diseases.
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Affiliation(s)
- Cindy Audiger
- Department of Immunology-Oncology, Maisonneuve-Rosemont Hospital, Montreal, Quebec H1T 2M4, Canada.,Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec H3C 3J7, Canada
| | - M Jubayer Rahman
- Immune Tolerance Section, Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Tae Jin Yun
- Laboratory of Cellular Physiology and Immunology, Clinical Research Institute of Montreal, Montreal, Quebec H2W 1R7, Canada; and.,Division of Experimental Medicine, Department of Medicine, McGill University, Montreal, Quebec H3A 1A3, Canada
| | - Kristin V Tarbell
- Immune Tolerance Section, Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Sylvie Lesage
- Department of Immunology-Oncology, Maisonneuve-Rosemont Hospital, Montreal, Quebec H1T 2M4, Canada; .,Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec H3C 3J7, Canada
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13
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Krueger A, Ziętara N, Łyszkiewicz M. T Cell Development by the Numbers. Trends Immunol 2016; 38:128-139. [PMID: 27842955 DOI: 10.1016/j.it.2016.10.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 10/21/2016] [Accepted: 10/25/2016] [Indexed: 01/01/2023]
Abstract
T cells are continually generated in the thymus in a highly dynamic process comprising discrete steps of lineage commitment, T cell receptor (TCR) gene rearrangement, and selection. These steps are linked to distinct rates of proliferation, survival, and cell death, but a quantitative picture of T cell development is only beginning to emerge. Here we summarize recent technical advances, including genetic fate mapping, barcoding, and molecular timers, that have allowed the implementation of computational models to quantify developmental dynamics in the thymus. Coupling new techniques with mathematical models has recently resulted in the emergence of new paradigms in early hematopoiesis and might similarly open new perspectives on T cell development.
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Affiliation(s)
- Andreas Krueger
- Institute of Molecular Medicine, Goethe University Frankfurt am Main, 60590 Frankfurt am Main, Germany.
| | - Natalia Ziętara
- Dr von Hauner Children's Hospital, Ludwig Maximilian University, 80337 Munich, Germany
| | - Marcin Łyszkiewicz
- Dr von Hauner Children's Hospital, Ludwig Maximilian University, 80337 Munich, Germany
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14
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Kohli K, Janssen A, Förster R. Plasmacytoid dendritic cells induce tolerance predominantly by cargoing antigen to lymph nodes. Eur J Immunol 2016; 46:2659-2668. [PMID: 27592607 PMCID: PMC5129535 DOI: 10.1002/eji.201646359] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 07/01/2016] [Accepted: 08/25/2016] [Indexed: 01/14/2023]
Abstract
Plasmacytoid dendritic cells (pDCs) have been shown to induce tolerance to innocuous antigens. Their migratory properties allow them to take up antigens from the periphery and transport them to the draining lymph nodes or to the thymus. However, pDC‐T‐cell interaction in the primary and secondary lymphoid organs still remains poorly defined. In this study, we show that resting pDCs loaded with exogenous antigen could induce tolerance when transferred intralymphatically into a single lymph node of wild‐type C57BL/6 mice. However, this was a result of antigen transfer from pDCs to endogenous antigen presenting cells and subsequent abortive proliferation of cognate CD4+ T cells. pDCs could not directly induce the proliferation of CD4+ T cells, as observed in mice lacking MHC class II gene. Moreover, pDCs failed to make physical contacts with OT‐II cells as revealed by two‐photon imaging. Thus, the role of resting pDCs in tolerance induction seems to be independent of its direct interaction with cognate CD4+ T cells.
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Affiliation(s)
- Karan Kohli
- Institute of Immunology, Hannover Medical School, Hannover, Germany
| | - Anika Janssen
- Institute of Immunology, Hannover Medical School, Hannover, Germany
| | - Reinhold Förster
- Institute of Immunology, Hannover Medical School, Hannover, Germany.
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15
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Stadinski BD, Shekhar K, Gómez-Touriño I, Jung J, Sasaki K, Sewell AK, Peakman M, Chakraborty AK, Huseby ES. Hydrophobic CDR3 residues promote the development of self-reactive T cells. Nat Immunol 2016; 17:946-55. [PMID: 27348411 PMCID: PMC4955740 DOI: 10.1038/ni.3491] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 05/12/2016] [Indexed: 12/11/2022]
Abstract
Studies of individual T cell antigen receptors (TCRs) have shed some light on structural features that underlie self-reactivity. However, the general rules that can be used to predict whether TCRs are self-reactive have not been fully elucidated. Here we found that the interfacial hydrophobicity of amino acids at positions 6 and 7 of the complementarity-determining region CDR3β robustly promoted the development of self-reactive TCRs. This property was found irrespective of the member of the β-chain variable region (Vβ) family present in the TCR or the length of the CDR3β. An index based on these findings distinguished Vβ2(+), Vβ6(+) and Vβ8.2(+) regulatory T cells from conventional T cells and also distinguished CD4(+) T cells selected by the major histocompatibility complex (MHC) class II molecule I-A(g7) (associated with the development of type 1 diabetes in NOD mice) from those selected by a non-autoimmunity-promoting MHC class II molecule I-A(b). Our results provide a means for distinguishing normal T cell repertoires versus autoimmunity-prone T cell repertoires.
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Affiliation(s)
- Brian D. Stadinski
- Department of Pathology, University of Massachusetts Medical School Worcester, MA 01605, USA
| | - Karthik Shekhar
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | | | - Jonathan Jung
- Department of Pathology, University of Massachusetts Medical School Worcester, MA 01605, USA
| | - Katsuhiro Sasaki
- Department of Pathology, University of Massachusetts Medical School Worcester, MA 01605, USA
| | - Andrew K. Sewell
- Division of Infection and Immunity, Cardiff University School of Medicine, Cardiff, UK
| | - Mark Peakman
- Department of Immunobiology, King's College London, London, UK
| | - Arup K. Chakraborty
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA 02139
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139., USA
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Eric S. Huseby
- Department of Pathology, University of Massachusetts Medical School Worcester, MA 01605, USA
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16
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Perry JSA, Hsieh CS. Development of T-cell tolerance utilizes both cell-autonomous and cooperative presentation of self-antigen. Immunol Rev 2016; 271:141-55. [PMID: 27088912 PMCID: PMC4837647 DOI: 10.1111/imr.12403] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The development of T-cell self-tolerance in the thymus is important for establishing immune homeostasis and preventing autoimmunity. Here, we review the components of T-cell tolerance, which includes T-cell receptor (TCR) self-reactivity, costimulation, cytokines, and antigen presentation by a variety of antigen-presenting cells (APCs) subsets. We discuss the current evidence on the process of regulatory T (Treg) cell and negative selection and the importance of TCR signaling. We then examine recent evidence showing unique roles for bone marrow (BM)-derived APCs and medullary thymic epithelial cells (mTECs) on the conventional and Treg TCR repertoire, as well as emerging data on the role of B cells in tolerance. Finally, we review the accumulating data that suggest that cooperative antigen presentation is a prominent component of T -ell tolerance. With the development of tools to interrogate the function of individual APC subsets in the medulla, we have gained greater understanding of the complex cellular and molecular events that determine T-cell tolerance.
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Affiliation(s)
- Justin S A Perry
- Department of Internal Medicine, Division of Rheumatology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Chyi-Song Hsieh
- Department of Internal Medicine, Division of Rheumatology, Washington University School of Medicine, St. Louis, MO, 63110, USA
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17
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Hirai T, Ishii R, Miyairi S, Ikemiyagi M, Omoto K, Ishii Y, Tanabe K. Clonal Deletion Established via Invariant NKT Cell Activation and Costimulatory Blockade Requires In Vivo Expansion of Regulatory T Cells. Am J Transplant 2016; 16:426-39. [PMID: 26495767 DOI: 10.1111/ajt.13493] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 08/12/2015] [Accepted: 08/17/2015] [Indexed: 01/25/2023]
Abstract
Recently, the immune-regulating potential of invariant natural killer T (iNKT) cells has attracted considerable attention. We previously reported that a combination treatment with a liposomal ligand for iNKT cells and an anti-CD154 antibody in a sublethally irradiated murine bone marrow transplant (BMT) model resulted in the establishment of mixed hematopoietic chimerism through in vivo expansion of regulatory T cells (Tregs). Herein, we show the lack of alloreactivity of CD8(+) T cells in chimeras and an early expansion of donor-derived dendritic cells (DCs) in the recipient thymi accompanied by a sequential reduction in the donor-reactive Vβ-T cell receptor repertoire, suggesting a contribution of clonal deletion in this model. Since thymic expansion of donor DCs and the reduction in the donor-reactive T cell repertoire were precluded with Treg depletion, we presumed that Tregs should preform before the establishment of clonal deletion. In contrast, the mice thymectomized before BMT failed to increase the number of Tregs and to establish CD8(+) T cell tolerance, suggesting the presence of mutual dependence between the thymic donor-DCs and Tregs. These results provide new insights into the regulatory mechanisms that actively promote clonal deletion.
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Affiliation(s)
- T Hirai
- Department of Urology, Tokyo Women's Medical University, Tokyo, Japan
| | - R Ishii
- Department of Urology, Tokyo Women's Medical University, Tokyo, Japan
| | - S Miyairi
- Department of Urology, Tokyo Women's Medical University, Tokyo, Japan
| | - M Ikemiyagi
- Department of Urology, Tokyo Women's Medical University, Tokyo, Japan
| | - K Omoto
- Department of Urology, Tokyo Women's Medical University, Tokyo, Japan
| | - Y Ishii
- Laboratory for Vaccine Design, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
| | - K Tanabe
- Department of Urology, Tokyo Women's Medical University, Tokyo, Japan
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18
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McDonald BD, Bunker JJ, Erickson SA, Oh-Hora M, Bendelac A. Crossreactive αβ T Cell Receptors Are the Predominant Targets of Thymocyte Negative Selection. Immunity 2015; 43:859-69. [PMID: 26522985 PMCID: PMC4654978 DOI: 10.1016/j.immuni.2015.09.009] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2015] [Revised: 06/28/2015] [Accepted: 09/23/2015] [Indexed: 11/18/2022]
Abstract
The precise impact of thymic positive and negative selection on the T cell receptor (TCR) repertoire remains controversial. Here, we used unbiased, high-throughput cloning and retroviral expression of individual pre-selection TCRs to provide a direct assessment of these processes at the clonal level in vivo. We found that 15% of random TCRs induced signaling and directed positive (7.5%) or negative (7.5%) selection, depending on strength of signal, whereas the remaining 85% failed to induce signaling or selection. Most negatively selected TCRs exhibited promiscuous crossreactivity toward multiple other major histocompatibility complex (MHC) haplotypes. In contrast, TCRs that were positively selected or non-selected were minimally crossreactive. Negative selection of crossreactive TCRs led to clonal deletion but also recycling into intestinal CD4(-)CD8β(-) intraepithelial lymphocytes (iIELs). Thus, broadly crossreactive TCRs arise at low frequency in the pre-selection repertoire but constitute the primary drivers of thymic negative selection and iIEL lineage differentiation.
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Affiliation(s)
- Benjamin D McDonald
- Committee on Immunology, University of Chicago, Chicago, IL 60637, USA; Department of Pathology, University of Chicago, Chicago, IL 60637, USA
| | - Jeffrey J Bunker
- Committee on Immunology, University of Chicago, Chicago, IL 60637, USA; Department of Pathology, University of Chicago, Chicago, IL 60637, USA
| | - Steven A Erickson
- Committee on Immunology, University of Chicago, Chicago, IL 60637, USA; Department of Pathology, University of Chicago, Chicago, IL 60637, USA
| | - Masatsugu Oh-Hora
- Division of Molecular Immunology, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan
| | - Albert Bendelac
- Committee on Immunology, University of Chicago, Chicago, IL 60637, USA; Department of Pathology, University of Chicago, Chicago, IL 60637, USA.
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19
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Oh J, Shin JS. The Role of Dendritic Cells in Central Tolerance. Immune Netw 2015; 15:111-20. [PMID: 26140042 PMCID: PMC4486773 DOI: 10.4110/in.2015.15.3.111] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 05/26/2015] [Accepted: 06/02/2015] [Indexed: 12/16/2022] Open
Abstract
Dendritic cells (DCs) play a significant role in establishing self-tolerance through their ability to present self-antigens to developing T cells in the thymus. DCs are predominantly localized in the medullary region of thymus and present a broad range of self-antigens, which include tissue-restricted antigens expressed and transferred from medullary thymic epithelial cells, circulating antigens directly captured by thymic DCs through coticomedullary junction blood vessels, and peripheral tissue antigens captured and transported by peripheral tissue DCs homing to the thymus. When antigen-presenting DCs make a high affinity interaction with antigen-specific thymocytes, this interaction drives the interacting thymocytes to death, a process often referred to as negative selection, which fundamentally blocks the self-reactive thymocytes from differentiating into mature T cells. Alternatively, the interacting thymocytes differentiate into the regulatory T (Treg) cells, a distinct T cell subset with potent immune suppressive activities. The specific mechanisms by which thymic DCs differentiate Treg cells have been proposed by several laboratories. Here, we review the literatures that elucidate the contribution of thymic DCs to negative selection and Treg cell differentiation, and discusses its potential mechanisms and future directions.
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Affiliation(s)
- Jaehak Oh
- Department of Microbiology and Immunology, Sandler Asthma Basic Research Center, University of California San Francisco, San Francisco, CA 94143, USA
| | - Jeoung-Sook Shin
- Department of Microbiology and Immunology, Sandler Asthma Basic Research Center, University of California San Francisco, San Francisco, CA 94143, USA
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20
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Yamano T, Nedjic J, Hinterberger M, Steinert M, Koser S, Pinto S, Gerdes N, Lutgens E, Ishimaru N, Busslinger M, Brors B, Kyewski B, Klein L. Thymic B Cells Are Licensed to Present Self Antigens for Central T Cell Tolerance Induction. Immunity 2015; 42:1048-61. [PMID: 26070482 DOI: 10.1016/j.immuni.2015.05.013] [Citation(s) in RCA: 172] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 03/20/2015] [Accepted: 04/13/2015] [Indexed: 12/22/2022]
Abstract
Thymic antigen-presenting cells (APCs) such as dendritic cells and medullary thymic epithelial cells (mTECs) use distinct strategies of self-antigen expression and presentation to mediate central tolerance. The thymus also harbors B cells; whether they also display unique tolerogenic features and how they genealogically relate to peripheral B cells is unclear. Here, we found that Aire is expressed in thymic but not peripheral B cells. Aire expression in thymic B cells coincided with major histocompatibility class II (MHCII) and CD80 upregulation and immunoglobulin class-switching. These features were recapitulated upon immigration of naive peripheral B cells into the thymus, whereby this intrathymic licensing required CD40 signaling in the context of cognate interactions with autoreactive CD4(+) thymocytes. Moreover, a licensing-dependent neo-antigen selectively upregulated in immigrating B cells mediated negative selection through direct presentation. Thus, autoreactivity within the nascent T cell repertoire fuels a feed forward loop that endows thymic B cells with tolerogenic features.
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Affiliation(s)
- Tomoyoshi Yamano
- Institute for Immunology, Ludwig-Maximilians-University Munich, Goethestrasse 31, 80336 Munich, Germany
| | - Jelena Nedjic
- Institute for Immunology, Ludwig-Maximilians-University Munich, Goethestrasse 31, 80336 Munich, Germany
| | - Maria Hinterberger
- Institute for Immunology, Ludwig-Maximilians-University Munich, Goethestrasse 31, 80336 Munich, Germany
| | - Madlen Steinert
- Institute for Immunology, Ludwig-Maximilians-University Munich, Goethestrasse 31, 80336 Munich, Germany
| | - Sandra Koser
- Division of Theoretical Bioinformatics, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Sheena Pinto
- Division of Developmental Immunology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Norbert Gerdes
- Institute for Cardiovascular Prevention, Ludwig-Maximilians-University Munich, Pettenkoferstrasse 9, 80336 Munich, Germany
| | - Esther Lutgens
- Institute for Cardiovascular Prevention, Ludwig-Maximilians-University Munich, Pettenkoferstrasse 9, 80336 Munich, Germany; Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 Amsterdam, the Netherlands
| | - Naozumi Ishimaru
- Department of Oral Molecular Pathology, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15 Kuramoto, Tokushima 770-8504, Japan
| | - Meinrad Busslinger
- Research Institute of Molecular Pathology, Vienna Biocenter, Dr. Bohr-Gasse 7, 1030 Vienna, Austria
| | - Benedikt Brors
- Division of Theoretical Bioinformatics, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Bruno Kyewski
- Division of Developmental Immunology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Ludger Klein
- Institute for Immunology, Ludwig-Maximilians-University Munich, Goethestrasse 31, 80336 Munich, Germany.
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21
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Melichar HJ, Ross JO, Taylor KT, Robey EA. Stable interactions and sustained TCR signaling characterize thymocyte-thymocyte interactions that support negative selection. THE JOURNAL OF IMMUNOLOGY 2014; 194:1057-1061. [PMID: 25520400 DOI: 10.4049/jimmunol.1400169] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Negative selection is one of the primary mechanisms that render T cells tolerant to self. Thymic dendritic cells play an important role in negative selection, in line with their ability to induce migratory arrest and sustained TCR signals. Thymocytes themselves display self-peptide/MHC class I complexes, and although there is evidence that they can support clonal deletion, it is not clear whether they do so directly via stable cell-cell contacts and sustained TCR signals. In this study, we show that murine thymocytes can support surprisingly efficient negative selection of Ag-specific thymocytes. Furthermore, we observe that agonist-dependent thymocyte-thymocyte interactions occurred as stable, motile conjugates led by the peptide-presenting thymocyte and in which the trailing peptide-specific thymocyte exhibited persistent elevations in intracellular calcium concentration. These data confirm that self-Ag presentation by thymocytes is an additional mechanism to ensure T cell tolerance and further strengthen the correlation between stable cellular contacts, sustained TCR signals, and efficient negative selection.
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Affiliation(s)
- Heather J Melichar
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Jenny O Ross
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Kayleigh T Taylor
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Ellen A Robey
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
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22
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Revisiting thymic positive selection and the mature T cell repertoire for antigen. Immunity 2014; 41:181-90. [PMID: 25148022 DOI: 10.1016/j.immuni.2014.07.007] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Indexed: 12/11/2022]
Abstract
To support effective host defense, the T cell repertoire must balance breadth of recognition with sensitivity for antigen. The concept that T lymphocytes are positively selected in the thymus is well established, but how this selection achieves such a repertoire has not been resolved. Here we suggest that it is direct linkage between self and foreign antigen recognition that produces the necessary blend of TCR diversity and specificity in the mature peripheral repertoire, enabling responses to a broad universe of unpredictable antigens while maintaining an adequate number of highly sensitive T cells in a population of limited size. Our analysis also helps to explain how diversity and frequency of antigen-reactive cells in a T cell repertoire are adjusted in animals of vastly different size scale to enable effective antipathogen responses and suggests a possible binary architecture in the TCR repertoire that is divided between germline-related optimal binding and diverse recognition.
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23
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Khailaie S, Robert PA, Toker A, Huehn J, Meyer-Hermann M. A signal integration model of thymic selection and natural regulatory T cell commitment. THE JOURNAL OF IMMUNOLOGY 2014; 193:5983-96. [PMID: 25392533 DOI: 10.4049/jimmunol.1400889] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The extent of TCR self-reactivity is the basis for selection of a functional and self-tolerant T cell repertoire and is quantified by repeated engagement of TCRs with a diverse pool of self-peptides complexed with self-MHC molecules. The strength of a TCR signal depends on the binding properties of a TCR to the peptide and the MHC, but it is not clear how the specificity to both components drives fate decisions. In this study, we propose a TCR signal-integration model of thymic selection that describes how thymocytes decide among distinct fates, not only based on a single TCR-ligand interaction, but taking into account the TCR stimulation history. These fates are separated based on sustained accumulated signals for positive selection and transient peak signals for negative selection. This spans up the cells into a two-dimensional space where they are either neglected, positively selected, negatively selected, or selected as natural regulatory T cells (nTregs). We show that the dynamics of the integrated signal can serve as a successful basis for extracting specificity of thymocytes to MHC and detecting the existence of cognate self-peptide-MHC. It allows to select a self-MHC-biased and self-peptide-tolerant T cell repertoire. Furthermore, nTregs in the model are enriched with MHC-specific TCRs. This allows nTregs to be more sensitive to activation and more cross-reactive than conventional T cells. This study provides a mechanistic model showing that time integration of TCR-mediated signals, as opposed to single-cell interaction events, is needed to gain a full view on the properties emerging from thymic selection.
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Affiliation(s)
- Sahamoddin Khailaie
- Department of Systems Immunology and Braunschweig Integrated Centre of Systems Biology, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Philippe A Robert
- Department of Systems Immunology and Braunschweig Integrated Centre of Systems Biology, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany; Institut de Génétique Moléculaire de Montpellier, Centre National de la Recherche Scientifique, 34293 Montpellier, France
| | - Aras Toker
- Department of Experimental Immunology, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany; and
| | - Jochen Huehn
- Department of Experimental Immunology, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany; and
| | - Michael Meyer-Hermann
- Department of Systems Immunology and Braunschweig Integrated Centre of Systems Biology, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany; Institute for Biochemistry, Biotechnology, and Bioinformatics, University of Technology Braunschweig, 38106 Braunschweig, Germany
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24
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Ni PP, Wang Y, Allen PM. Both positive and negative effects on immune responses by expression of a second class II MHC molecule. Mol Immunol 2014; 62:199-208. [PMID: 25016574 PMCID: PMC4157116 DOI: 10.1016/j.molimm.2014.06.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Revised: 06/19/2014] [Accepted: 06/20/2014] [Indexed: 12/24/2022]
Abstract
It is perplexing why vertebrates express a limited number of major histocompatibility complex (MHC) molecules when theoretically, having a greater repertoire of MHC molecules would increase the number of epitopes presented, thereby enhancing thymic selection and T cell response to pathogens. It is possible that any positive effects would either be neutralized or outweighed by negative selection restricting the T cell repertoire. We hypothesize that the limit on MHC number is due to negative consequences arising from expressing additional MHC. We compared T cell responses between B6 mice (I-A(+)) and B6.E(+) mice (I-A(+), I-E(+)), the latter expressing a second class II MHC molecule, I-E(b), due to a monomorphic Eα(k) transgene that pairs with the endogenous I-Eβ(b) chain. First, the naive T cell Vβ repertoire was altered in B6.E(+) thymi and spleens, potentially mediating different outcomes in T cell reactivity. Although the B6 and B6.E(+) responses to hen egg-white lysozyme (HEL) protein immunization remained similar, other immune models yielded differences. For viral infection, the quality of the T cell response was subtly altered, with diminished production of certain cytokines by B6.E(+) CD4(+) T cells. In alloreactivity, the B6.E(+) T cell response was significantly dampened. Finally, we observed markedly enhanced susceptibility to experimental autoimmune encephalomyelitis (EAE) in B6.E(+) mice. This correlated with decreased percentages of nTreg cells, supporting the concept of Tregs exhibiting differential susceptibility to negative selection. Altogether, our data suggest that expressing an additional class II MHC can produce diverse effects, with more severe autoimmunity providing a compelling explanation for limiting the expression of MHC molecules.
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Affiliation(s)
- Peggy P Ni
- Department of Pathology and Immunology, Washington University School of Medicine, 660 S. Euclid, Box 8118, St. Louis, MO 63110, United States
| | - Yaming Wang
- Department of Pathology and Immunology, Washington University School of Medicine, 660 S. Euclid, Box 8118, St. Louis, MO 63110, United States
| | - Paul M Allen
- Department of Pathology and Immunology, Washington University School of Medicine, 660 S. Euclid, Box 8118, St. Louis, MO 63110, United States.
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25
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Perry JSA, Lio CWJ, Kau AL, Nutsch K, Yang Z, Gordon JI, Murphy KM, Hsieh CS. Distinct contributions of Aire and antigen-presenting-cell subsets to the generation of self-tolerance in the thymus. Immunity 2014; 41:414-426. [PMID: 25220213 PMCID: PMC4175925 DOI: 10.1016/j.immuni.2014.08.007] [Citation(s) in RCA: 180] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 08/18/2014] [Indexed: 02/07/2023]
Abstract
The contribution of thymic antigen-presenting-cell (APC) subsets in selecting a self-tolerant T cell population remains unclear. We show that bone marrow (BM) APCs and medullary thymic epithelial cells (mTECs) played nonoverlapping roles in shaping the T cell receptor (TCR) repertoire by deletion and regulatory T (Treg) cell selection of distinct TCRs. Aire, which induces tissue-specific antigen expression in mTECs, affected the TCR repertoire in a manner distinct from mTEC presentation. Approximately half of Aire-dependent deletion or Treg cell selection utilized a pathway dependent on antigen presentation by BM APCs. Batf3-dependent CD8α⁺ dendritic cells (DCs) were the crucial BM APCs for Treg cell selection via this pathway, showing enhanced ability to present antigens from stromal cells. These results demonstrate the division of function between thymic APCs in shaping the self-tolerant TCR repertoire and reveal an unappreciated cooperation between mTECs and CD8α⁺ DCs for presentation of Aire-induced self-antigens to developing thymocytes.
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Affiliation(s)
- Justin S A Perry
- Division of Rheumatology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Chan-Wang J Lio
- Division of Rheumatology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Andrew L Kau
- Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63108, USA
| | - Katherine Nutsch
- Division of Rheumatology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Zhuo Yang
- Division of Rheumatology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Jeffrey I Gordon
- Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63108, USA
| | - Kenneth M Murphy
- Howard Hughes Medical Institute and Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Chyi-Song Hsieh
- Division of Rheumatology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA.
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26
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Savage PA, Leventhal DS, Malchow S. Shaping the repertoire of tumor-infiltrating effector and regulatory T cells. Immunol Rev 2014; 259:245-58. [PMID: 24712470 PMCID: PMC4122093 DOI: 10.1111/imr.12166] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Many tumors express antigens that can be specifically or selectively recognized by T lymphocytes, suggesting that T-cell-mediated immunity may be harnessed for the immunotherapy of cancer. However, since tumors originate from normal cells and evolve within the context of self-tissues, the immune mechanisms that prevent the autoimmune attack of normal tissues function in parallel to restrict anti-tumor immunity. In particular, the purging of autoreactive T cells and the development of immune-suppressive regulatory T cells (Tregs) are thought to be major barriers impeding anti-tumor immune responses. Here, we discuss current understanding regarding the antigens recognized by tumor-infiltrating T-cell populations, the mechanisms that shape the repertoire of these cells, and the role of the transcription factor autoimmune regulator (Aire) in these processes. Further elucidation of these principles is likely to be critical for optimizing emerging cancer immunotherapies, and for the rational design of novel therapies exhibiting robust anti-tumor activity with limited toxicity.
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Affiliation(s)
- Peter A. Savage
- Department of Pathology, University of Chicago, Chicago, IL 60637
| | | | - Sven Malchow
- Department of Pathology, University of Chicago, Chicago, IL 60637
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27
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Ragonnaud E, Holst P. The rationale of vectored gene-fusion vaccines against cancer: evolving strategies and latest evidence. THERAPEUTIC ADVANCES IN VACCINES 2014; 1:33-47. [PMID: 24757514 DOI: 10.1177/2051013613480446] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The development of vaccines that target tumor antigens in cancer has proven difficult. A major reason for this is that T cells specific for tumor self-antigens and neoantigens are eliminated or inactivated through mechanisms of tolerance. Antigen fusion strategies which increase the ability of vaccines to stimulate T cells that have escaped tolerance mechanisms, may have a particular potential as immunotherapies. This review highlights antigen fusion strategies that have been successful in stimulating the induction of T-cell immunity against cancer and counteracting tumor-associated tolerance. In preclinical studies, these strategies have shown to improve the potency of vectored vaccines through fusion of tumor antigen to proteins or protein domains that increase CD4+ T-cell help, CD8+ T-cell responses or both the CD4+ and CD8+ T-cell responses. However, in clinical trials such strategies seem to be less efficient when provided as a DNA vaccine. The first clinical trial using a viral vectored fusion-gene vaccine is expected to be tested as a partner in a heterologous prime-boost regimen directed against cervical cancer.
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Affiliation(s)
| | - Peter Holst
- ISIM - Center for Medical Parasitology, Copenhagen, Denmark
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28
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Sawicka M, Stritesky GL, Reynolds J, Abourashchi N, Lythe G, Molina-París C, Hogquist KA. From pre-DP, post-DP, SP4, and SP8 Thymocyte Cell Counts to a Dynamical Model of Cortical and Medullary Selection. Front Immunol 2014; 5:19. [PMID: 24592261 PMCID: PMC3924582 DOI: 10.3389/fimmu.2014.00019] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Accepted: 01/15/2014] [Indexed: 01/15/2023] Open
Abstract
Cells of the mature αβ T cell repertoire arise from the development in the thymus of bone marrow precursors (thymocytes). αβ T cell maturation is characterized by the expression of thousands of copies of identical αβ T cell receptors and the CD4 and/or CD8 co-receptors on the surface of thymocytes. The maturation stages of a thymocyte are: (1) double negative (DN) (TCR−, CD4− and CD8−), (2) double positive (DP) (TCR+, CD4+ and CD8+), and (3) single positive (SP) (TCR+, CD4+ or CD8+). Thymic antigen presenting cells provide the appropriate micro-architecture for the maturation of thymocytes, which “sense” the signaling environment via their randomly generated TCRs. Thymic development is characterized by (i) an extremely low success rate, and (ii) the selection of a functional and self-tolerant T cell repertoire. In this paper, we combine recent experimental data and mathematical modeling to study the selection events that take place in the thymus after the DN stage. The stable steady state of the model for the pre-DP, post-DP, and SP populations is identified with the experimentally measured cell counts from 5.5- to 17-week-old mice. We make use of residence times in the cortex and the medulla for the different populations, as well as recently reported asymmetric death rates for CD4 and CD8 SP thymocytes. We estimate that 65.8% of pre-DP thymocytes undergo death by neglect. In the post-DP compartment, 91.7% undergo death by negative selection, 4.7% become CD4 SP, and 3.6% become CD8 SP. Death by negative selection in the medulla removes 8.6% of CD4 SP and 32.1% of CD8 SP thymocytes. Approximately 46.3% of CD4 SP and 27% of CD8 SP thymocytes divide before dying or exiting the thymus.
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Affiliation(s)
- Maria Sawicka
- Department of Applied Mathematics, School of Mathematics, University of Leeds , Leeds , UK
| | - Gretta L Stritesky
- Department of Laboratory Medicine and Pathology, Center for Immunology, University of Minnesota , Minneapolis, MN , USA
| | - Joseph Reynolds
- Department of Applied Mathematics, School of Mathematics, University of Leeds , Leeds , UK
| | - Niloufar Abourashchi
- Department of Applied Mathematics, School of Mathematics, University of Leeds , Leeds , UK
| | - Grant Lythe
- Department of Applied Mathematics, School of Mathematics, University of Leeds , Leeds , UK
| | - Carmen Molina-París
- Department of Applied Mathematics, School of Mathematics, University of Leeds , Leeds , UK
| | - Kristin A Hogquist
- Department of Laboratory Medicine and Pathology, Center for Immunology, University of Minnesota , Minneapolis, MN , USA
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29
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Abstract
The peripheral T cell repertoire is sculpted from prototypic T cells in the thymus bearing randomly generated T cell receptors (TCR) and by a series of developmental and selection steps that remove cells that are unresponsive or overly reactive to self-peptide–MHC complexes. The challenge of understanding how the kinetics of T cell development and the statistics of the selection processes combine to provide a diverse but self-tolerant T cell repertoire has invited quantitative modeling approaches, which are reviewed here.
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Affiliation(s)
- Andrew J Yates
- Departments of Systems and Computational Biology, Microbiology and Immunology, Albert Einstein College of Medicine , New York, NY , USA
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30
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Abstract
The evolutionary emergence of vertebrates was accompanied by major morphological and functional innovations, including the development of an adaptive immune system. Vertebrate adaptive immunity is based on the clonal expression of somatically diversifying antigen receptors on lymphocytes. This is a common feature of both the jawless and jawed vertebrates , although these two groups of extant vertebrates employ structurally different types of antigen receptors and principal mechanisms for their somatic diversification . These observations suggest that the common vertebrate ancestor must have already possessed a complex immune system, including B- and T-like lymphocyte lineages and primary lymphoid organs, such as the thymus, but possibly lacked the facilities for somatic diversification of antigen receptors. Interestingly, memory formation, previously considered to be a defining feature of adaptive immunity, also occurs in the context of innate immune responses and can even be observed in unicellular organisms, attesting to the convergent evolutionary history of distinct aspects of adaptive immunity.
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Affiliation(s)
- Thomas Boehm
- Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany; ,
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31
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Melichar HJ, Ross JO, Herzmark P, Hogquist KA, Robey EA. Distinct temporal patterns of T cell receptor signaling during positive versus negative selection in situ. Sci Signal 2013; 6:ra92. [PMID: 24129702 DOI: 10.1126/scisignal.2004400] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The recognition by the T cell receptor (TCR) of self-peptides presented by the major histocompatibility complex (MHC) on antigen-presenting cells, such as dendritic cells and thymic epithelial cells, controls T cell fate in the thymus, with weak TCR signals inducing survival (positive selection) and stronger signals inducing death (negative selection). In vitro studies indicate that peptide ligands that induce positive selection stimulate a low, but sustained, pattern of TCR signaling; however, the temporal pattern of TCR signaling in MHC class I-restricted thymocytes (thymocytes that are presented with peptides by MHC class I) in the thymus, under conditions that support positive selection, is unknown. We addressed this question by examining intracellular Ca(2+) dynamics and migratory changes in thymocytes undergoing positive and negative selection in thymic slices. Brief, serial signaling events that were separated by migratory periods and low cytosolic Ca(2+) concentrations correlated with the positive selection of MHC class I-restricted thymocytes, whereas sustained Ca(2+) signaling and the arrest of thymocytes were associated with negative selection. Low-avidity peptides and the presentation of peptides by cortical thymic epithelial cells, rather than dendritic cells, failed to induce strong migratory arrest of thymocytes, which led to transient TCR signaling. Thus, we provide a comparison of positive and negative selection signals in situ and suggest that the absence of strong stop signals distinguishes between positive and negative selection.
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Affiliation(s)
- Heather J Melichar
- 1Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
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32
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Abstract
T cells orchestrate pathogen-specific adaptive immune responses by identifying peptides derived from pathogenic proteins that are displayed on the surface of infected cells. Host cells also display peptide fragments from the host's own proteins. Incorrectly identifying peptides derived from the body's own proteome as pathogenic can result in autoimmune disease. To minimize autoreactivity, immature T cells that respond to self-peptides are deleted in the thymus by a process called negative selection. However, negative selection is imperfect, and autoreactive T cells exist in healthy individuals. To understand how autoimmunity is yet avoided, without loss of responsiveness to pathogens, we have developed a model of T-cell training and response. Our model shows that T cells reliably respond to infection and avoid autoimmunity because collective decisions made by the T-cell population, rather than the responses of individual T cells, determine biological outcomes. The theory is qualitatively consistent with experimental data and yields a criterion for thymic selection to be adequate for suppressing autoimmunity.
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Long-term prevention of chronic allograft rejection by regulatory T-cell immunotherapy involves host Foxp3-expressing T cells. Blood 2013; 121:4303-10. [DOI: 10.1182/blood-2012-08-452037] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Key Points
Administration of donor-specific regulatory T cells prevents chronic rejection of BM and skin allografts in the mouse. Injected regulatory T cells induce the emergence of host regulatory T cells with similar specificity thus ensuring persistence of tolerance.
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Mingueneau M, Kreslavsky T, Gray D, Heng T, Cruse R, Ericson J, Bendall S, Spitzer MH, Nolan GP, Kobayashi K, von Boehmer H, Mathis D, Benoist C, Best AJ, Knell J, Goldrath A, Joic V, Koller D, Shay T, Regev A, Cohen N, Brennan P, Brenner M, Kim F, Nageswara Rao T, Wagers A, Heng T, Ericson J, Rothamel K, Ortiz-Lopez A, Mathis D, Benoist C, Bezman NA, Sun JC, Min-Oo G, Kim CC, Lanier LL, Miller J, Brown B, Merad M, Gautier EL, Jakubzick C, Randolph GJ, Monach P, Blair DA, Dustin ML, Shinton SA, Hardy RR, Laidlaw D, Collins J, Gazit R, Rossi DJ, Malhotra N, Sylvia K, Kang J, Kreslavsky T, Fletcher A, Elpek K, Bellemare-Pelletier A, Malhotra D, Turley S. The transcriptional landscape of αβ T cell differentiation. Nat Immunol 2013; 14:619-32. [PMID: 23644507 PMCID: PMC3660436 DOI: 10.1038/ni.2590] [Citation(s) in RCA: 215] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Accepted: 03/19/2013] [Indexed: 12/11/2022]
Abstract
αβT cell differentiation from thymic precursors is a complex process, explored here with the breadth of ImmGen expression datasets, analyzing how differentiation of thymic precursors gives rise to transcriptomes. After surprisingly gradual changes though early T commitment, transit through the CD4+CD8+ stage involves a shutdown or rare breadth, and correlating tightly with MYC. MHC-driven selection promotes a large-scale transcriptional reactivation. We identify distinct signatures that mark cells destined for positive selection versus apoptotic deletion. Differential expression of surprisingly few genes accompany CD4 or CD8 commitment, a similarity that carries through to peripheral T cells and their activation, revealed by mass cytometry phosphoproteomics. The novel transcripts identified as candidate mediators of key transitions help define the “known unknown” of thymocyte differentiation.
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Affiliation(s)
- Michael Mingueneau
- Division of Immunology, Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, USA
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35
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Shi Y, Zhu M. Medullary thymic epithelial cells, the indispensable player in central tolerance. SCIENCE CHINA. LIFE SCIENCES 2013; 56:392-8. [PMID: 23633070 DOI: 10.1007/s11427-013-4482-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 03/21/2013] [Indexed: 02/06/2023]
Abstract
Crosstalk between thymocytes and thymic epithelial cells is critical for T cell development and the establishment of central tolerance. Medullary thymic epithelial cells (mTECs) play important roles in the late stage of T cell development, especially negative selection and Treg generation. The function of mTECs is highly dependent on their characteristic features such as ectopic expression of peripheral tissue restricted antigens (TRAs) and their master regulator-autoimmune regulator (Aire), expression of various chemokines and cytokines. In this review, we summarize the current understanding of cellular and molecular mechanisms of mTEC development and its functions in T cell development and the establishment of central tolerance. The open questions in this field are also discussed. Understanding the function and underlying mechanisms of mTECs will contribute to the better control of autoimmune diseases and the improvement of immune reconstitution during aging or after infection, chemotherapy or radiotherapy.
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Affiliation(s)
- Yaoyao Shi
- Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
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36
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Murine thymic selection quantified using a unique method to capture deleted T cells. Proc Natl Acad Sci U S A 2013; 110:4679-84. [PMID: 23487759 DOI: 10.1073/pnas.1217532110] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Thymic positive and negative selection events generate a T-cell repertoire that is MHC restricted and self-tolerant. The number of T cells undergoing positive and negative selection in normal mice has never been firmly established. We generated mice that lack the proapoptotic molecule Bim (bcl2l11) together with a Nur77(GFP) transgene, which allowed the identification and enumeration of T cells that would normally undergo clonal deletion. Using this method, we report the striking observation that six times more cells undergo negative selection than complete positive selection. Seventy-five percent of the negatively selected cells are deleted at the double positive stage in the thymic cortex, compared with 25% at the single positive stage in the medulla. The fact that more thymocytes are highly reactive to MHC than are weakly reactive is inconsistent with a random model of recognition and suggests that T-cell recognition is MHC biased. Furthermore, Bim(-/-) mice had an increased number of GFP(hi) cells in the peripheral lymphoid tissue and a corresponding increase in antigen experienced or anergic cell phenotype. Our data also show that the CD4+ T cells that are clonally deleted experienced only slightly stronger T-cell receptor signaling than those that developed into regulatory T cells.
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37
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Abstract
Inflammatory bowel disease is characterized by a number of immunological alterations, not the least in the T-cell compartment. Numerous animal models of colitis have revealed aberrant thymocyte dynamics associated with skewed thymocyte development. The recent advancements in quantitative methods have proposed critical kinetic alterations in the thymocyte development during the progression of colitis. This review focuses on the aberrant thymocyte dynamics in Gαi2-deficient mice as this mouse model provides most quantitative data of the thymocyte development associated with colitis. Herein, we discuss several dynamic changes during the progression of colitis and propose a hypothesis for the underlying causes for the skewed proportions of the thymocyte populations seen in the Gαi2-deficient mice and in other mouse models of colitis.
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Guerri L, Peguillet I, Geraldo Y, Nabti S, Premel V, Lantz O. Analysis of APC types involved in CD4 tolerance and regulatory T cell generation using reaggregated thymic organ cultures. THE JOURNAL OF IMMUNOLOGY 2013; 190:2102-10. [PMID: 23365074 DOI: 10.4049/jimmunol.1202883] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Tolerance to self-Ags is generated in the thymus. Both epithelial and hematopoietic thymic stromal cells play an active and essential role in this process. However, the role of each of the various stromal cell types remains unresolved. To our knowledge, we describe the first comparative analysis of several types of thymic hematopoietic stromal cells (THSCs) for their ability to induce CD4 tolerance to self, in parallel with the thymic epithelium. The THSCs--two types of conventional dendritic cells (cDCs), plasmacytoid dendritic cells, macrophages (MΦs), B lymphocytes, and eosinophils--were first characterized and quantified in adult mouse thymus. They were then examined in reaggregated thymic organ cultures containing mixtures of monoclonal and polyclonal thymocytes. This thymocyte mixture allows for the analysis of Ag-specific events while avoiding the extreme skewing frequently seen in purely monoclonal systems. Our data indicate that thymic epithelium alone is capable of promoting self-tolerance by eliminating autoreactive CD4 single-positive thymocytes and by supporting regulatory T cell (Treg) development. We also show that both non-Treg CD4 single-positive thymocytes and Tregs are efficiently deleted by the two populations of cDCs present in the thymus, as well as to a lesser extent by MΦs. Plasmacytoid dendritic cells, B lymphocytes, and eosinophils were not able to do so. Finally, cDCs were also the most efficient THSCs at supporting Treg development in the thymus, suggesting that although they may share some characteristics required for negative selection with MΦs, they do not share those required for the support of Treg development, making cDCs a unique cell subset in the thymus.
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Affiliation(s)
- Lucia Guerri
- INSERM U932 and Centre d'Investigation Clinique, CIC-BT507, Institut Curie, Paris 75005, France.
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39
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Daley SR, Hu DY, Goodnow CC. Helios marks strongly autoreactive CD4+ T cells in two major waves of thymic deletion distinguished by induction of PD-1 or NF-κB. ACTA ACUST UNITED AC 2013; 210:269-85. [PMID: 23337809 PMCID: PMC3570102 DOI: 10.1084/jem.20121458] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Expression of the transcription factor Helios identifies thymocyte divergence during positive and negative selection. Acquisition of self-tolerance in the thymus requires T cells to discriminate strong versus weak T cell receptor binding by self-peptide–MHC complexes. We find this discrimination is reported by expression of the transcription factor Helios, which is induced during negative selection but decreases during positive selection. Helios and the proapoptotic protein Bim were coinduced in 55% of nascent CCR7− CD4+ CD69+ thymocytes. These were short-lived cells that up-regulated PD-1 and down-regulated CD4 and CD8 during Bim-dependent apoptosis. Helios and Bim were also coinduced at the subsequent CCR7+ CD4+ CD69+ CD8− stage, and this second wave of Bim-dependent negative selection involved 20% of nascent cells. Unlike CCR7− counterparts, Helios+ CCR7+ CD4+ cells mount a concurrent Card11- and c-Rel–dependent activation response that opposes Bim-mediated apoptosis. This “hollow” activation response consists of many NF-κB target genes but lacks key growth mediators like IL-2 and Myc, and the thymocytes were not induced to proliferate. These findings identify Helios as the first marker known to diverge during positive and negative selection of thymocytes and reveal the extent, stage, and molecular nature of two distinct waves of clonal deletion in the normal thymus.
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Affiliation(s)
- Stephen R Daley
- Department of Immunology, The John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory 0200, Australia
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40
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Romagnoli P, Dooley J, Enault G, Vicente R, Malissen B, Liston A, van Meerwijk JPM. The Thymic Niche Does Not Limit Development of the Naturally Diverse Population of Mouse Regulatory T Lymphocytes. THE JOURNAL OF IMMUNOLOGY 2012; 189:3831-7. [DOI: 10.4049/jimmunol.1201564] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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41
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Currie J, Castro M, Lythe G, Palmer E, Molina-París C. A stochastic T cell response criterion. J R Soc Interface 2012; 9:2856-70. [PMID: 22745227 PMCID: PMC3479899 DOI: 10.1098/rsif.2012.0205] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The adaptive immune system relies on different cell types to provide fast and coordinated responses, characterized by recognition of pathogenic challenge, extensive cellular proliferation and differentiation, as well as death. T cells are a subset of the adaptive immune cellular pool that recognize immunogenic peptides expressed on the surface of antigen-presenting cells by means of specialized receptors on their membrane. T cell receptor binding to ligand determines T cell responses at different times and locations during the life of a T cell. Current experimental evidence provides support to the following: (i) sufficiently long receptor–ligand engagements are required to initiate the T cell signalling cascade that results in productive signal transduction and (ii) counting devices are at work in T cells to allow signal accumulation, decoding and translation into biological responses. In the light of these results, we explore, with mathematical models, the timescales associated with T cell responses. We consider two different criteria: a stochastic one (the mean time it takes to have had N receptor–ligand complexes bound for at least a dwell time, τ, each) and one based on equilibrium (the time to reach a threshold number N of receptor–ligand complexes). We have applied mathematical models to previous experiments in the context of thymic negative selection and to recent two-dimensional experiments. Our results indicate that the stochastic criterion provides support to the thymic affinity threshold hypothesis, whereas the equilibrium one does not, and agrees with the ligand hierarchy experimentally established for thymic negative selection.
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Affiliation(s)
- James Currie
- Department of Applied Mathematics, School of Mathematics, University of Leeds, Leeds LS2 9JT, UK
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42
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Fleishman SJ, Baker D. Role of the biomolecular energy gap in protein design, structure, and evolution. Cell 2012; 149:262-73. [PMID: 22500796 DOI: 10.1016/j.cell.2012.03.016] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Indexed: 01/29/2023]
Abstract
The folding of natural biopolymers into unique three-dimensional structures that determine their function is remarkable considering the vast number of alternative states and requires a large gap in the energy of the functional state compared to the many alternatives. This Perspective explores the implications of this energy gap for computing the structures of naturally occurring biopolymers, designing proteins with new structures and functions, and optimally integrating experiment and computation in these endeavors. Possible parallels between the generation of functional molecules in computational design and natural evolution are highlighted.
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Affiliation(s)
- Sarel J Fleishman
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.
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43
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Billiard F, Lobry C, Darrasse-Jèze G, Waite J, Liu X, Mouquet H, DaNave A, Tait M, Idoyaga J, Leboeuf M, Kyratsous CA, Burton J, Kalter J, Klinakis A, Zhang W, Thurston G, Merad M, Steinman RM, Murphy AJ, Yancopoulos GD, Aifantis I, Skokos D. Dll4-Notch signaling in Flt3-independent dendritic cell development and autoimmunity in mice. ACTA ACUST UNITED AC 2012; 209:1011-28. [PMID: 22547652 PMCID: PMC3348095 DOI: 10.1084/jem.20111615] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Delta-like ligand 4 (Dll4)-Notch signaling is essential for T cell development and alternative thymic lineage decisions. How Dll4-Notch signaling affects pro-T cell fate and thymic dendritic cell (tDC) development is unknown. We found that Dll4 pharmacological blockade induces accumulation of tDCs and CD4(+)CD25(+)FoxP3(+) regulatory T cells (T(reg) cells) in the thymic cortex. Both genetic inactivation models and anti-Dll4 antibody (Ab) treatment promote de novo natural T(reg) cell expansion by a DC-dependent mechanism that requires major histocompatibility complex II expression on DCs. Anti-Dll4 treatment converts CD4(-)CD8(-)c-kit(+)CD44(+)CD25(-) (DN1) T cell progenitors to immature DCs that induce ex vivo differentiation of naive CD4(+) T cells into T(reg) cells. Induction of these tolerogenic DN1-derived tDCs and the ensuing expansion of T(reg) cells are Fms-like tyrosine kinase 3 (Flt3) independent, occur in the context of transcriptional up-regulation of PU.1, Irf-4, Irf-8, and CSF-1, genes critical for DC differentiation, and are abrogated in thymectomized mice. Anti-Dll4 treatment fully prevents type 1 diabetes (T1D) via a T(reg) cell-mediated mechanism and inhibits CD8(+) T cell pancreatic islet infiltration. Furthermore, a single injection of anti-Dll4 Ab reverses established T1D. Disease remission and recurrence are correlated with increased T(reg) cell numbers in the pancreas-draining lymph nodes. These results identify Dll4-Notch as a novel Flt3-alternative pathway important for regulating tDC-mediated T(reg) cell homeostasis and autoimmunity.
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44
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CIITA promoter I CARD-deficient mice express functional MHC class II genes in myeloid and lymphoid compartments. Genes Immun 2012; 13:299-310. [PMID: 22218223 PMCID: PMC3366023 DOI: 10.1038/gene.2011.86] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Three distinct promoters control the master regulator of MHC class II expression, CIITA, in a cell type specific manner. Promoter I (pI) CIITA, expressed primarily by dendritic cells and macrophages, expresses a unique isoform that contains a caspase recruitment domain. The activity and function of this isoform is not understood but has been thought to enhance the function of CIITA in antigen presenting cells. To determine if isoform I of CIITA has specific functions, CIITA mutant mice were created in which isoform I was replaced with isoform III sequences. Mice in which pI and the CARD encoding exon were deleted were also created. No defect in the formation of CD4 T cells, the ability to respond to a model antigen, or bacterial or viral challenge was observed in mice lacking CIITA isoform I. Although CIITA and MHC-II expression was decreased in splenic DC, the pI knockout animals expressed CIITA from downstream promoters, suggesting that control of pI activity is mediated by unknown s II distal elements that could act at the pIII, the B cell promoter. Thus, no critical function is linked to the CARD domain of CIITA isoform I with respect to basic immune system development, function and challenge.
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45
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Stritesky GL, Jameson SC, Hogquist KA. Selection of self-reactive T cells in the thymus. Annu Rev Immunol 2011; 30:95-114. [PMID: 22149933 DOI: 10.1146/annurev-immunol-020711-075035] [Citation(s) in RCA: 237] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
On the whole, the healthy adaptive immune system is responsive to foreign antigens and tolerant to self. However, many individual lymphocytes have, and even require, substantial self-reactivity for their particular functions in immunity. In this review, we discuss several populations of lymphocytes that are thought to experience agonist stimulation through the T cell receptor during selection: nTreg cells, iNKT cells, nIELs, and nTh17s. We discuss the nature of this self-reactivity, how it compares with conventional T cells, and why it is important for overall immune health. We also outline molecular pathways unique to each lineage and consider possible commonalities to their development and survival.
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Affiliation(s)
- Gretta L Stritesky
- Center for Immunology and Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, Minnesota 55455, USA
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46
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Abstract
The discovery of regulatory T cells (Tregs) as a crucial component of peripheral down-regulation of immunity to self and allogeneic antigens has raised legitimate hope for the development of Treg-based clinical protocols for tolerance to allografts. The present review addresses the question of whether therapeutic Tregs are ready to enter the clinical transplantation arena. In light of recent experimental observations, we will revisit some fundamentals of T cell and Treg biology that stress the need for further studies prior to applications and provide conceptual cues for novel therapeutic approaches.
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Affiliation(s)
- Christian Leguern
- Transplantation Biology Research Center, Department of Surgery, Massachusetts General Hospital East, Harvard Medical School, Boston, MA 02129, USA.
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47
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Pomié C, Vicente R, Vuddamalay Y, Lundgren BA, van der Hoek M, Enault G, Kagan J, Fazilleau N, Scott HS, Romagnoli P, van Meerwijk JPM. Autoimmune regulator (AIRE)-deficient CD8+CD28low regulatory T lymphocytes fail to control experimental colitis. Proc Natl Acad Sci U S A 2011; 108:12437-42. [PMID: 21746930 PMCID: PMC3145727 DOI: 10.1073/pnas.1107136108] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mutations in the gene encoding the transcription factor autoimmune regulator (AIRE) are responsible for autoimmune polyendocrinopathy candidiasis ectodermal dystrophy syndrome. AIRE directs expression of tissue-restricted antigens in the thymic medulla and in lymph node stromal cells and thereby substantially contributes to induction of immunological tolerance to self-antigens. Data from experimental mouse models showed that AIRE deficiency leads to impaired deletion of autospecific T-cell precursors. However, a potential role for AIRE in the function of regulatory T-cell populations, which are known to play a central role in prevention of immunopathology, has remained elusive. Regulatory T cells of CD8(+)CD28(low) phenotype efficiently control immune responses in experimental autoimmune and colitis models in mice. Here we show that CD8(+)CD28(low) regulatory T lymphocytes from AIRE-deficient mice are transcriptionally and phenotypically normal and exert efficient suppression of in vitro immune responses, but completely fail to prevent experimental colitis in vivo. Our data therefore demonstrate that AIRE plays an important role in the in vivo function of a naturally occurring regulatory T-cell population.
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Affiliation(s)
- Céline Pomié
- Institut National de la Santé et de la Recherche Médicale, U1043, Toulouse F-31300, France
- Centre National de la Recherche Scientifique, U5282, Toulouse F-31300, France
- Centre de Physiopathologie de Toulouse Purpan, Université Paul Sabatier, Université de Toulouse, Toulouse F-31300, France
| | - Rita Vicente
- Institut National de la Santé et de la Recherche Médicale, U1043, Toulouse F-31300, France
- Centre National de la Recherche Scientifique, U5282, Toulouse F-31300, France
- Centre de Physiopathologie de Toulouse Purpan, Université Paul Sabatier, Université de Toulouse, Toulouse F-31300, France
| | - Yirajen Vuddamalay
- Institut National de la Santé et de la Recherche Médicale, U1043, Toulouse F-31300, France
- Centre National de la Recherche Scientifique, U5282, Toulouse F-31300, France
- Centre de Physiopathologie de Toulouse Purpan, Université Paul Sabatier, Université de Toulouse, Toulouse F-31300, France
| | - Brita Ardesjö Lundgren
- Department of Molecular Pathology, Centre for Cancer Biology, SA Pathology, Adelaide, South Australia 5000, Australia
| | - Mark van der Hoek
- Adelaide Microarray Centre, SA Pathology, Adelaide, South Australia 5000, Australia
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide, South Australia 5000, Australia
| | - Geneviève Enault
- Institut National de la Santé et de la Recherche Médicale, U1043, Toulouse F-31300, France
- Centre National de la Recherche Scientifique, U5282, Toulouse F-31300, France
- Centre de Physiopathologie de Toulouse Purpan, Université Paul Sabatier, Université de Toulouse, Toulouse F-31300, France
| | - Jérémy Kagan
- Institut National de la Santé et de la Recherche Médicale, U1043, Toulouse F-31300, France
- Centre National de la Recherche Scientifique, U5282, Toulouse F-31300, France
- Centre de Physiopathologie de Toulouse Purpan, Université Paul Sabatier, Université de Toulouse, Toulouse F-31300, France
| | - Nicolas Fazilleau
- Institut National de la Santé et de la Recherche Médicale, U1043, Toulouse F-31300, France
- Centre National de la Recherche Scientifique, U5282, Toulouse F-31300, France
- Centre de Physiopathologie de Toulouse Purpan, Université Paul Sabatier, Université de Toulouse, Toulouse F-31300, France
| | - Hamish S. Scott
- Department of Molecular Pathology, Centre for Cancer Biology, SA Pathology, Adelaide, South Australia 5000, Australia
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide, South Australia 5000, Australia
- School of Medicine, University of Adelaide, Adelaide, South Australia 5005, Australia; and
| | - Paola Romagnoli
- Institut National de la Santé et de la Recherche Médicale, U1043, Toulouse F-31300, France
- Centre National de la Recherche Scientifique, U5282, Toulouse F-31300, France
- Centre de Physiopathologie de Toulouse Purpan, Université Paul Sabatier, Université de Toulouse, Toulouse F-31300, France
| | - Joost P. M. van Meerwijk
- Institut National de la Santé et de la Recherche Médicale, U1043, Toulouse F-31300, France
- Centre National de la Recherche Scientifique, U5282, Toulouse F-31300, France
- Centre de Physiopathologie de Toulouse Purpan, Université Paul Sabatier, Université de Toulouse, Toulouse F-31300, France
- Institut Universitaire de France, Paris F-75000, France
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48
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Abstract
The immunological function of the thymus was first documented 50 years ago by using neonatally thymectomized mice, while studying its role in virus-induced leukaemia. Since then, an enormous wealth of reports has helped to define the importance of this primary lymphoid organ. In this article, I summarize the key advances that have led to our current knowledge of the functions of the thymus and its T cells in immunity.
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49
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Klein L, Hinterberger M, von Rohrscheidt J, Aichinger M. Autonomous versus dendritic cell-dependent contributions of medullary thymic epithelial cells to central tolerance. Trends Immunol 2011; 32:188-93. [PMID: 21493141 DOI: 10.1016/j.it.2011.03.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 03/02/2011] [Accepted: 03/04/2011] [Indexed: 12/27/2022]
Abstract
Promiscuous expression of 'peripheral' tissue-restricted antigens (TRAs) by medullary thymic epithelial cells (mTECs) is essential for central tolerance. Remarkably, the expression of individual TRAs varies among mTECs and is confined to a perplexingly small number of cells. To reconcile this with the ensuing robust state of tolerance, one might envisage that mTECs serve primarily as an antigen reservoir, whereas tolerogenic recognition of TRAs would ultimately require antigen uptake and presentation by dendritic cells (DCs). Here, we survey the evidence for this 'antigen-spreading' scenario and relate it to findings that document autonomous antigen-presentation by mTECs. We suggest that DC-dependent and autonomous tolerogenic functions of mTECs operate in parallel, and the underlying mechanisms remain to be established.
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Affiliation(s)
- Ludger Klein
- University of Munich, Institute for Immunology, Goethestr. 31, 80336 Munich, Germany.
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Abstract
Both jawless vertebrates, such as lampreys and hagfish, and jawed vertebrates (encompassing species as diverse as sharks and humans) have an adaptive immune system that is based on somatically diversified and clonally expressed antigen receptors. Although the molecular nature of the antigen receptors and the mechanisms of their assembly are different, recent findings suggest that the general design principles underlying the two adaptive immune systems are surprisingly similar. The identification of such commonalities promises to further our understanding of the mammalian immune system and to inspire the development of new strategies for medical interventions targeting the consequences of faulty immune functions.
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Affiliation(s)
- Thomas Boehm
- Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, Stuebeweg 51, D-79108 Freiburg, Germany.
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