1
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Anderson G, Cosway EJ, James KD, Ohigashi I, Takahama Y. Generation and repair of thymic epithelial cells. J Exp Med 2024; 221:e20230894. [PMID: 38980292 PMCID: PMC11232892 DOI: 10.1084/jem.20230894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 05/20/2024] [Accepted: 06/10/2024] [Indexed: 07/10/2024] Open
Abstract
In the vertebrate immune system, thymus stromal microenvironments support the generation of αβT cells from immature thymocytes. Thymic epithelial cells are of particular importance, and the generation of cortical and medullary epithelial lineages from progenitor stages controls the initiation and maintenance of thymus function. Here, we discuss the developmental pathways that regulate thymic epithelial cell diversity during both the embryonic and postnatal periods. We also examine how thymus microenvironments respond to injury, with particular focus on mechanisms that ensure regeneration of thymic epithelial cells for the restoration of thymus function.
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Affiliation(s)
- Graham Anderson
- Institute for Immunology and Immunotherapy, University of Birmingham , Birmingham, UK
| | - Emilie J Cosway
- Institute for Immunology and Immunotherapy, University of Birmingham , Birmingham, UK
| | - Kieran D James
- Institute for Immunology and Immunotherapy, University of Birmingham , Birmingham, UK
| | - Izumi Ohigashi
- Division of Experimental Immunology, Institute of Advanced Medical Sciences, University of Tokushima, Tokushima, Japan
| | - Yousuke Takahama
- Thymus Biology Section, Experimental Immunology Branch, National Cancer Institute, National Institutes of Health , Bethesda, MD, USA
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2
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Chiu H, Weinstein KN, Spath S, Hu A, Varela S, Obata-Ninomiya K, Ziegler SF. SKI Regulates Medullary Thymic Epithelial Cell Differentiation to Control Peripheral T Cell Responses in Mice. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2024; 213:52-62. [PMID: 38767415 PMCID: PMC11182718 DOI: 10.4049/jimmunol.2300262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 04/15/2024] [Indexed: 05/22/2024]
Abstract
The thymus is an important site for the establishment of an appropriate immune response through positive and negative selection of developing T cells. During selection, developing T cells interact with cortical and medullary thymic epithelial cells (TECs), termed cTECs and mTECs, respectively. Using a Foxn1Cre+/-SKIfl/fl mouse model, we found that TEC-specific deletion of SKI reduced the mTEC compartment in the thymus and that tissue-restricted Ag expression in mTECs was altered. This decrease in the medullary area led to a decrease in CD4 thymocyte cellularity; however, mature CD4 cellularity in the spleen remained normal. Interestingly, naive CD4 T cells purified from SKI-deleted mice showed a defect in proliferation in vitro after global TCR stimulation, and these mice were significantly protected from developing experimental autoimmune encephalomyelitis compared with the control mice. Overall, our findings suggest that SKI signaling in the thymus regulates mTEC differentiation and function as well as downstream peripheral T cell responses and provide evidence for targeting SKI in T cell-driven autoimmune diseases such as multiple sclerosis.
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3
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Fang Y, Bansal K, Mostafavi S, Benoist C, Mathis D. AIRE relies on Z-DNA to flag gene targets for thymic T cell tolerization. Nature 2024; 628:400-407. [PMID: 38480882 PMCID: PMC11091860 DOI: 10.1038/s41586-024-07169-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 02/06/2024] [Indexed: 03/18/2024]
Abstract
AIRE is an unconventional transcription factor that enhances the expression of thousands of genes in medullary thymic epithelial cells and promotes clonal deletion or phenotypic diversion of self-reactive T cells1-4. The biological logic of AIRE's target specificity remains largely unclear as, in contrast to many transcription factors, it does not bind to a particular DNA sequence motif. Here we implemented two orthogonal approaches to investigate AIRE's cis-regulatory mechanisms: construction of a convolutional neural network and leveraging natural genetic variation through analysis of F1 hybrid mice5. Both approaches nominated Z-DNA and NFE2-MAF as putative positive influences on AIRE's target choices. Genome-wide mapping studies revealed that Z-DNA-forming and NFE2L2-binding motifs were positively associated with the inherent ability of a gene's promoter to generate DNA double-stranded breaks, and promoters showing strong double-stranded break generation were more likely to enter a poised state with accessible chromatin and already-assembled transcriptional machinery. Consequently, AIRE preferentially targets genes with poised promoters. We propose a model in which Z-DNA anchors the AIRE-mediated transcriptional program by enhancing double-stranded break generation and promoter poising. Beyond resolving a long-standing mechanistic conundrum, these findings suggest routes for manipulating T cell tolerance.
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Affiliation(s)
- Yuan Fang
- Department of Immunology, Harvard Medical School, Boston, MA, USA
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Kushagra Bansal
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
| | - Sara Mostafavi
- Paul G. Allen School of Computer Science and Engineering, University of Washington, Seattle, WA, USA
- Canadian Institute for Advanced Research, Toronto, Ontario, Canada
| | | | - Diane Mathis
- Department of Immunology, Harvard Medical School, Boston, MA, USA.
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4
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Shirafkan F, Hensel L, Rattay K. Immune tolerance and the prevention of autoimmune diseases essentially depend on thymic tissue homeostasis. Front Immunol 2024; 15:1339714. [PMID: 38571951 PMCID: PMC10987875 DOI: 10.3389/fimmu.2024.1339714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 03/11/2024] [Indexed: 04/05/2024] Open
Abstract
The intricate balance of immune reactions towards invading pathogens and immune tolerance towards self is pivotal in preventing autoimmune diseases, with the thymus playing a central role in establishing and maintaining this equilibrium. The induction of central immune tolerance in the thymus involves the elimination of self-reactive T cells, a mechanism essential for averting autoimmunity. Disruption of the thymic T cell selection mechanisms can lead to the development of autoimmune diseases. In the dynamic microenvironment of the thymus, T cell migration and interactions with thymic stromal cells are critical for the selection processes that ensure self-tolerance. Thymic epithelial cells are particularly significant in this context, presenting self-antigens and inducing the negative selection of autoreactive T cells. Further, the synergistic roles of thymic fibroblasts, B cells, and dendritic cells in antigen presentation, selection and the development of regulatory T cells are pivotal in maintaining immune responses tightly regulated. This review article collates these insights, offering a comprehensive examination of the multifaceted role of thymic tissue homeostasis in the establishment of immune tolerance and its implications in the prevention of autoimmune diseases. Additionally, the developmental pathways of the thymus are explored, highlighting how genetic aberrations can disrupt thymic architecture and function, leading to autoimmune conditions. The impact of infections on immune tolerance is another critical area, with pathogens potentially triggering autoimmunity by altering thymic homeostasis. Overall, this review underscores the integral role of thymic tissue homeostasis in the prevention of autoimmune diseases, discussing insights into potential therapeutic strategies and examining putative avenues for future research on developing thymic-based therapies in treating and preventing autoimmune conditions.
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5
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Oftedal BE, Sjøgren T, Wolff ASB. Interferon autoantibodies as signals of a sick thymus. Front Immunol 2024; 15:1327784. [PMID: 38455040 PMCID: PMC10917889 DOI: 10.3389/fimmu.2024.1327784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 02/07/2024] [Indexed: 03/09/2024] Open
Abstract
Type I interferons (IFN-I) are key immune messenger molecules that play an important role in viral defense. They act as a bridge between microbe sensing, immune function magnitude, and adaptive immunity to fight infections, and they must therefore be tightly regulated. It has become increasingly evident that thymic irregularities and mutations in immune genes affecting thymic tolerance can lead to the production of IFN-I autoantibodies (autoAbs). Whether these biomarkers affect the immune system or tissue integrity of the host is still controversial, but new data show that IFN-I autoAbs may increase susceptibility to severe disease caused by certain viruses, including SARS-CoV-2, herpes zoster, and varicella pneumonia. In this article, we will elaborate on disorders that have been identified with IFN-I autoAbs, discuss models of how tolerance to IFN-Is is lost, and explain the consequences for the host.
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Affiliation(s)
- Bergithe E. Oftedal
- Department of Clinical Science, University of Bergen, Bergen, Norway
- Department of Medicine, Haukeland University Hospital, Bergen, Norway
| | - Thea Sjøgren
- Department of Medicine, Haukeland University Hospital, Bergen, Norway
| | - Anette S. B. Wolff
- Department of Clinical Science, University of Bergen, Bergen, Norway
- Department of Medicine, Haukeland University Hospital, Bergen, Norway
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6
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Lammers S, Barrera V, Brennecke P, Miller C, Yoon J, Balolong J, Anderson MS, Ho Sui S, Steinmetz LM, von Andrian UH, Rattay K. Ehf and Fezf2 regulate late medullary thymic epithelial cell and thymic tuft cell development. Front Immunol 2024; 14:1277365. [PMID: 38420512 PMCID: PMC10901246 DOI: 10.3389/fimmu.2023.1277365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 12/29/2023] [Indexed: 03/02/2024] Open
Abstract
Thymic epithelial cells are indispensable for T cell maturation and selection and the induction of central immune tolerance. The self-peptide repertoire expressed by medullary thymic epithelial cells is in part regulated by the transcriptional regulator Aire (Autoimmune regulator) and the transcription factor Fezf2. Due to the high complexity of mTEC maturation stages (i.e., post-Aire, Krt10+ mTECs, and Dclk1+ Tuft mTECs) and the heterogeneity in their gene expression profiles (i.e., mosaic expression patterns), it has been challenging to identify the additional factors complementing the transcriptional regulation. We aimed to identify the transcriptional regulators involved in the regulation of mTEC development and self-peptide expression in an unbiased and genome-wide manner. We used ATAC footprinting analysis as an indirect approach to identify transcription factors involved in the gene expression regulation in mTECs, which we validated by ChIP sequencing. This study identifies Fezf2 as a regulator of the recently described thymic Tuft cells (i.e., Tuft mTECs). Furthermore, we identify that transcriptional regulators of the ELF, ESE, ERF, and PEA3 subfamily of the ETS transcription factor family and members of the Krüppel-like family of transcription factors play a role in the transcriptional regulation of genes involved in late mTEC development and promiscuous gene expression.
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Affiliation(s)
- Sören Lammers
- Institute for Theoretical Physics, Heidelberg University, Heidelberg, Germany
| | - Victor Barrera
- Bioinformatics Core, Harvard T.H. Chan School of Public Health, Boston, MA, United States
| | - Philip Brennecke
- Department of Genetics, Stanford University, School of Medicine, Stanford, CA, United States
- Stanford Genome Technology Center, Stanford University, Stanford, CA, United States
| | - Corey Miller
- Diabetes Center, University of California, San Francisco (UCSF), San Francisco, CA, United States
| | - Joon Yoon
- Bioinformatics Core, Harvard T.H. Chan School of Public Health, Boston, MA, United States
| | - Jared Balolong
- Diabetes Center, University of California, San Francisco (UCSF), San Francisco, CA, United States
| | - Mark S. Anderson
- Diabetes Center, University of California, San Francisco (UCSF), San Francisco, CA, United States
| | - Shannan Ho Sui
- Bioinformatics Core, Harvard T.H. Chan School of Public Health, Boston, MA, United States
| | - Lars M. Steinmetz
- Department of Genetics, Stanford University, School of Medicine, Stanford, CA, United States
- Stanford Genome Technology Center, Stanford University, Stanford, CA, United States
- Genome Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Ulrich H. von Andrian
- Department of Immunology & HMS Center for Immune Imaging, Harvard Medical School, Boston, MA, United States
- The Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, United States
| | - Kristin Rattay
- Department of Immunology & HMS Center for Immune Imaging, Harvard Medical School, Boston, MA, United States
- Pharmacological Institute, Biochemical Pharmacological Center, University of Marburg, Marburg, Germany
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7
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Matsumoto M, Matsumoto M. Learning the Autoimmune Pathogenesis Through the Study of Aire. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024; 1444:19-32. [PMID: 38467970 DOI: 10.1007/978-981-99-9781-7_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
One of the difficulties in studying the pathogenesis of autoimmune diseases is that the disease is multifactorial involving sex, age, MHC, environment, and some genetic factors. Because deficiency of Aire, a transcriptional regulator, is an autoimmune disease caused by a single gene abnormality, Aire is an ideal research target for approaching the enigma of autoimmunity, e.g., the mechanisms underlying Aire deficiency can be studied using genetically modified animals. Nevertheless, the exact mechanisms of the breakdown of self-tolerance due to Aire's dysfunction have not yet been fully clarified. This is due, at least in part, to the lack of information on the exact target genes controlled by Aire. State-of-the-art research infrastructures such as single-cell analysis are now in place to elucidate the essential function of Aire. The knowledge gained through the study of Aire-mediated tolerance should help our understanding of the pathogenesis of autoimmune disease in general.
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Affiliation(s)
| | - Minoru Matsumoto
- Department of Molecular Pathology, Tokushima University Graduate School of Biomedical Sciences, Tokushima, Japan
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8
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Sin JH, Sucharov J, Kashyap S, Wang Y, Proekt I, Liu X, Parent AV, Gupta A, Kastner P, Chan S, Gardner JM, Ntranos V, Miller CN, Anderson MS, Schjerven H, Waterfield MR. Ikaros is a principal regulator of Aire + mTEC homeostasis, thymic mimetic cell diversity, and central tolerance. Sci Immunol 2023; 8:eabq3109. [PMID: 37889983 DOI: 10.1126/sciimmunol.abq3109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 10/04/2023] [Indexed: 10/29/2023]
Abstract
Mutations in the gene encoding the zinc-finger transcription factor Ikaros (IKZF1) are found in patients with immunodeficiency, leukemia, and autoimmunity. Although Ikaros has a well-established function in modulating gene expression programs important for hematopoietic development, its role in other cell types is less well defined. Here, we uncover functions for Ikaros in thymic epithelial lineage development in mice and show that Ikzf1 expression in medullary thymic epithelial cells (mTECs) is required for both autoimmune regulator-positive (Aire+) mTEC development and tissue-specific antigen (TSA) gene expression. Accordingly, TEC-specific deletion of Ikzf1 in mice results in a profound decrease in Aire+ mTECs, a global loss of TSA gene expression, and the development of autoimmunity. Moreover, Ikaros shapes thymic mimetic cell diversity, and its deletion results in a marked expansion of thymic tuft cells and muscle-like mTECs and a loss of other Aire-dependent mimetic populations. Single-cell analysis reveals that Ikaros modulates core transcriptional programs in TECs that correlate with the observed cellular changes. Our findings highlight a previously undescribed role for Ikaros in regulating epithelial lineage development and function and suggest that failed thymic central tolerance could contribute to the autoimmunity seen in humans with IKZF1 mutations.
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Affiliation(s)
- Jun Hyung Sin
- Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, USA
- Department of Pediatrics, University of California San Francisco, San Francisco, CA, USA
| | - Juliana Sucharov
- Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, USA
| | - Sujit Kashyap
- Department of Pediatrics, University of California San Francisco, San Francisco, CA, USA
| | - Yi Wang
- Diabetes Center, University of California San Francisco, San Francisco, CA, USA
- 10x Genomics, Pleasanton, CA, USA
| | - Irina Proekt
- Diabetes Center, University of California San Francisco, San Francisco, CA, USA
| | - Xian Liu
- Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, USA
- Diabetes Center, University of California San Francisco, San Francisco, CA, USA
| | - Audrey V Parent
- Diabetes Center, University of California San Francisco, San Francisco, CA, USA
| | - Alexander Gupta
- Diabetes Center, University of California San Francisco, San Francisco, CA, USA
- Department of Surgery, University of California San Francisco, San Francisco, CA, USA
| | - Philippe Kastner
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U 1258, CNRS UMR 7104, Université de Strasbourg, 67404 Illkirch, France
| | - Susan Chan
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U 1258, CNRS UMR 7104, Université de Strasbourg, 67404 Illkirch, France
| | - James M Gardner
- Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, USA
- Diabetes Center, University of California San Francisco, San Francisco, CA, USA
- Department of Surgery, University of California San Francisco, San Francisco, CA, USA
| | - Vasilis Ntranos
- Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, USA
- Diabetes Center, University of California San Francisco, San Francisco, CA, USA
| | - Corey N Miller
- Diabetes Center, University of California San Francisco, San Francisco, CA, USA
| | - Mark S Anderson
- Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, USA
- Diabetes Center, University of California San Francisco, San Francisco, CA, USA
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Hilde Schjerven
- Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, USA
- Department of Laboratory Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Michael R Waterfield
- Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, USA
- Department of Pediatrics, University of California San Francisco, San Francisco, CA, USA
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9
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Michelson DA, Zuo C, Verzi M, Benoist C, Mathis D. Hnf4 activates mimetic-cell enhancers to recapitulate gut and liver development within the thymus. J Exp Med 2023; 220:e20230461. [PMID: 37399024 PMCID: PMC10318407 DOI: 10.1084/jem.20230461] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/16/2023] [Accepted: 06/16/2023] [Indexed: 07/04/2023] Open
Abstract
Mimetic cells are medullary thymic epithelial cells (mTECs) that mimic extra-thymic cell types to tolerize T cells to self-antigens. Here, we dissected the biology of entero-hepato mTECs, mimetic cells expressing gut- and liver-associated transcripts. Entero-hepato mTECs conserved their thymic identity yet accessed wide swaths of enterocyte chromatin and transcriptional programs via the transcription factors Hnf4α and Hnf4γ. Deletion of Hnf4α and Hnf4γ in TECs ablated entero-hepato mTECs and downregulated numerous gut- and liver-associated transcripts, with a primary contribution from Hnf4γ. Loss of Hnf4 impaired enhancer activation and CTCF redistribution in mTECs but did not impact Polycomb-mediated repression or promoter-proximal histone marks. By single-cell RNA sequencing, Hnf4 loss produced three distinct effects on mimetic cell state, fate, and accumulation. Serendipitously, a requirement for Hnf4 in microfold mTECs was discovered, which exposed a requirement for Hnf4γ in gut microfold cells and the IgA response. Study of Hnf4 in entero-hepato mTECs thus revealed mechanisms of gene control in the thymus and periphery alike.
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Affiliation(s)
| | - Chong Zuo
- Department of Immunology, Harvard Medical School, Boston, MA, USA
| | - Michael Verzi
- Department of Genetics, Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ, USA
- Rutgers Cancer Institute of New Jersey, Rutgers University, New Brunswick, NJ, USA
| | | | - Diane Mathis
- Department of Immunology, Harvard Medical School, Boston, MA, USA
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10
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Cabric V, Brown CC. Thymic mimicry: The art of imitation. J Exp Med 2023; 220:e20231010. [PMID: 37516920 PMCID: PMC10374940 DOI: 10.1084/jem.20231010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/31/2023] Open
Abstract
Display of tissue self-antigens within the thymus is critical for the regulation of self-reactive T cells. In this issue of JEM, Michelson et al. (2023. J. Exp. Med.https://doi.org/10.1084/jem.20230461) continue to advance our understanding of self-antigen representation by medullary thymic epithelial cells, identifying a new role for Hnf4γ in the regulation of thymic mimetic cells as well as their peripheral counterparts.
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Affiliation(s)
- Vanja Cabric
- Immuno-Oncology, Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Chrysothemis C. Brown
- Immuno-Oncology, Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Immunology and Microbial Pathogenesis Program, Weill Cornell Medicine Graduate School of Medical Sciences, New York, NY, USA
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11
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Hor JL, Germain RN. Spatiotemporal and cell-state control of antigen presentation during tolerance and immunity. Curr Opin Immunol 2023; 84:102357. [PMID: 37331219 DOI: 10.1016/j.coi.2023.102357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 05/18/2023] [Accepted: 05/19/2023] [Indexed: 06/20/2023]
Abstract
Effective adaptive immunity is rendered possible by highly organized tissue architecture and coordinated cellular crosstalk. While detailed spatiotemporal analyses of antigen presentation and adaptive immune activation in secondary lymphoid tissues have been a major focus of study, it is clear that antigen presentation in other tissues also plays a critical role in shaping the immune response. In this article, we concentrate on two opposing aspects of adaptive immunity: tolerance and antitumor immunity, to illustrate how a complex set of antigen presentation mechanisms contributes to maintaining a delicate balance between robust immunity and avoidance of autoimmune pathology. We emphasize the importance of how immune cell identity, state, and location collectively determine the nature of adaptive immune responses.
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Affiliation(s)
- Jyh Liang Hor
- Lymphocyte Biology Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-1892, USA
| | - Ronald N Germain
- Lymphocyte Biology Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-1892, USA.
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12
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Chiu H, Linsley PS, Ziegler SF. Investigating Thymic Epithelial Cell Diversity Using Systems Biology. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2023; 210:888-894. [PMID: 36947816 PMCID: PMC10037528 DOI: 10.4049/jimmunol.2200610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 10/12/2022] [Indexed: 03/24/2023]
Abstract
The thymus is an intricate organ consisting of a diverse population of thymic epithelial cells (TECs). Cortical and medullary TECs and their subpopulations have distinct roles in coordinating the development and selection of functionally competent and self-tolerant T cells. Recent advances made in technologies such as single-cell RNA sequencing have made it possible to investigate and resolve the heterogeneity in TECs. These findings have provided further understanding of the molecular mechanisms regulating TEC function and expression of tissue-restricted Ags. In this brief review, we focus on the newly characterized subsets of TECs and their diversity in relation to their functions in supporting T cell development. We also discuss recent discoveries in expression of self-antigens in the context of TEC development as well as the cellular and molecular changes occurring during embryonic development to thymic involution.
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13
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Matsumoto M, Yoshida H, Tsuneyama K, Oya T, Matsumoto M. Revisiting Aire and tissue-restricted antigens at single-cell resolution. Front Immunol 2023; 14:1176450. [PMID: 37207224 PMCID: PMC10191227 DOI: 10.3389/fimmu.2023.1176450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 04/20/2023] [Indexed: 05/21/2023] Open
Abstract
The thymus is a highly specialized organ that plays an indispensable role in the establishment of self-tolerance, a process characterized by the "education" of developing T-cells. To provide competent T-cells tolerant to self-antigens, medullary thymic epithelial cells (mTECs) orchestrate negative selection by ectopically expressing a wide range of genes, including various tissue-restricted antigens (TRAs). Notably, recent advancements in the high-throughput single-cell analysis have revealed remarkable heterogeneity in mTECs, giving us important clues for dissecting the mechanisms underlying TRA expression. We overview how recent single-cell studies have furthered our understanding of mTECs, with a focus on the role of Aire in inducing mTEC heterogeneity to encompass TRAs.
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Affiliation(s)
- Minoru Matsumoto
- Department of Molecular Pathology, Tokushima University Graduate School of Biomedical Sciences, Tokushima, Japan
- Division of Molecular Immunology, Institute for Enzyme Research, Tokushima University, Tokushima, Japan
- *Correspondence: Minoru Matsumoto,
| | - Hideyuki Yoshida
- YCI Laboratory for Immunological Transcriptomics, RIKEN Center for Integrative Medical Science, Yokohama, Japan
| | - Koichi Tsuneyama
- Department of Pathology and Laboratory Medicine, Tokushima University Graduate School of Biomedical Sciences, Tokushima, Japan
| | - Takeshi Oya
- Department of Molecular Pathology, Tokushima University Graduate School of Biomedical Sciences, Tokushima, Japan
| | - Mitsuru Matsumoto
- Division of Molecular Immunology, Institute for Enzyme Research, Tokushima University, Tokushima, Japan
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14
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Michelson DA, Mathis D. Thymic mimetic cells: tolerogenic masqueraders. Trends Immunol 2022; 43:782-791. [PMID: 36008259 PMCID: PMC9509455 DOI: 10.1016/j.it.2022.07.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 07/28/2022] [Accepted: 07/29/2022] [Indexed: 10/15/2022]
Abstract
Medullary thymic epithelial cells (mTECs) clonally delete or divert autoreactive T cells by ectopically expressing a diverse array of peripheral-tissue antigens (PTAs) within the thymus. Although thymic stromal cells with histological features of extra-thymic cell types, like myocytes or neurons, have been observed by light microscopy since the mid-1800s, most modern work on PTA expression has focused on the transcription factor Aire. Here, we highlight recent work that has refocused attention on such 'misplaced' thymic cells, referred to collectively as thymic mimetic cells. We review the molecular underpinnings of mimetic cells and their roles in establishing T cell tolerance, and we propose that mimetic cells play important roles in autoimmunity. Finally, we suggest future directions for this emerging area.
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Affiliation(s)
| | - Diane Mathis
- Department of Immunology, Harvard Medical School, Boston, MA 02115, USA.
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15
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Březina J, Vobořil M, Filipp D. Mechanisms of Direct and Indirect Presentation of Self-Antigens in the Thymus. Front Immunol 2022; 13:926625. [PMID: 35774801 PMCID: PMC9237256 DOI: 10.3389/fimmu.2022.926625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 05/16/2022] [Indexed: 11/13/2022] Open
Abstract
The inevitability of evolution of the adaptive immune system with its mechanism of randomly rearranging segments of the T cell receptor (TCR) gene is the generation of self-reactive clones. For the sake of prevention of autoimmunity, these clones must be eliminated from the pool of circulating T cells. This process occurs largely in the thymic medulla where the strength of affinity between TCR and self-peptide MHC complexes is the factor determining thymocyte fate. Thus, the display of self-antigens in the thymus by thymic antigen presenting cells, which are comprised of medullary thymic epithelial (mTECs) and dendritic cells (DCs), is fundamental for the establishment of T cell central tolerance. Whereas mTECs produce and present antigens in a direct, self-autonomous manner, thymic DCs can acquire these mTEC-derived antigens by cooperative antigen transfer (CAT), and thus present them indirectly. While the basic characteristics for both direct and indirect presentation of self-antigens are currently known, recent reports that describe the heterogeneity of mTEC and DC subsets, their presentation capacity, and the potentially non-redundant roles in T cell selection processes represents another level of complexity which we are attempting to unravel. In this review, we underscore the seminal studies relevant to these topics with an emphasis on new observations pertinent to the mechanism of CAT and its cellular trajectories underpinning the preferential distribution of thymic epithelial cell-derived self-antigens to specific subsets of DC. Identification of molecular determinants which control CAT would significantly advance our understanding of how the cellularly targeted presentation of thymic self-antigens is functionally coupled to the T cell selection process.
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Affiliation(s)
| | | | - Dominik Filipp
- Laboratory of Immunobiology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
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16
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Lancaster JN, Keatinge‐Clay DE, Srinivasan J, Li Y, Selden HJ, Nam S, Richie ER, Ehrlich LIR. Central tolerance is impaired in the middle-aged thymic environment. Aging Cell 2022; 21:e13624. [PMID: 35561351 PMCID: PMC9197411 DOI: 10.1111/acel.13624] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 04/03/2022] [Accepted: 04/20/2022] [Indexed: 12/03/2022] Open
Abstract
One of the earliest hallmarks of immune aging is thymus involution, which not only reduces the number of newly generated and exported T cells, but also alters the composition and organization of the thymus microenvironment. Thymic T‐cell export continues into adulthood, yet the impact of thymus involution on the quality of newly generated T‐cell clones is not well established. Notably, the number and proportion of medullary thymic epithelial cells (mTECs) and expression of tissue‐restricted antigens (TRAs) decline with age, suggesting the involuting thymus may not promote efficient central tolerance. Here, we demonstrate that the middle‐aged thymic environment does not support rapid motility of medullary thymocytes, potentially diminishing their ability to scan antigen presenting cells (APCs) that display the diverse self‐antigens that induce central tolerance. Consistent with this possibility, thymic slice assays reveal that the middle‐aged thymic environment does not support efficient negative selection or regulatory T‐cell (Treg) induction of thymocytes responsive to either TRAs or ubiquitous self‐antigens. This decline in central tolerance is not universal, but instead impacts lower‐avidity self‐antigens that are either less abundant or bind to TCRs with moderate affinities. Additionally, the decline in thymic tolerance by middle age is accompanied by both a reduction in mTECs and hematopoietic APC subsets that cooperate to drive central tolerance. Thus, age‐associated changes in the thymic environment result in impaired central tolerance against moderate‐avidity self‐antigens, potentially resulting in export of increasingly autoreactive naive T cells, with a deficit of Treg counterparts by middle age.
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Affiliation(s)
- Jessica N. Lancaster
- Department of Molecular Biosciences The University of Texas at Austin Austin Texas USA
| | | | - Jayashree Srinivasan
- Department of Molecular Biosciences The University of Texas at Austin Austin Texas USA
| | - Yu Li
- Department of Molecular Biosciences The University of Texas at Austin Austin Texas USA
| | - Hilary J. Selden
- Department of Molecular Biosciences The University of Texas at Austin Austin Texas USA
| | - Seohee Nam
- Department of Molecular Biosciences The University of Texas at Austin Austin Texas USA
| | - Ellen R. Richie
- Department of Epigenetics and Molecular Carcinogenesis The University of Texas MD Anderson Cancer Center Houston Texas USA
| | - Lauren I. R. Ehrlich
- Department of Molecular Biosciences The University of Texas at Austin Austin Texas USA
- Department of Oncology Dell Medical School at The University of Texas at Austin Austin Texas USA
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17
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Thymic epithelial cells co-opt lineage-defining transcription factors to eliminate autoreactive T cells. Cell 2022; 185:2542-2558.e18. [DOI: 10.1016/j.cell.2022.05.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 03/21/2022] [Accepted: 05/19/2022] [Indexed: 12/13/2022]
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18
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Monteleone-Cassiano AC, Dernowsek JA, Mascarenhas RS, Assis AF, Pitol D, Santos Moreira NC, Sakamoto-Hojo ET, Issa JPM, Donadi EA, Passos GA. The absence of the autoimmune regulator gene (AIRE) impairs the three-dimensional structure of medullary thymic epithelial cell spheroids. BMC Mol Cell Biol 2022; 23:15. [PMID: 35331137 PMCID: PMC8952272 DOI: 10.1186/s12860-022-00414-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 03/11/2022] [Indexed: 11/14/2022] Open
Abstract
Background Besides controlling the expression of peripheral tissue antigens, the autoimmune regulator (AIRE) gene also regulates the expression of adhesion genes in medullary thymic epithelial cells (mTECs), an essential process for mTEC-thymocyte interaction for triggering the negative selection in the thymus. For these processes to occur, it is necessary that the medulla compartment forms an adequate three-dimensional (3D) architecture, preserving the thymic medulla. Previous studies have shown that AIRE knockout (KO) mice have a small and disorganized thymic medulla; however, whether AIRE influences the mTEC-mTEC interaction in the maintenance of the 3D structure has been little explored. Considering that AIRE controls cell adhesion genes, we hypothesized that this gene affects 3D mTEC-mTEC interaction. To test this, we constructed an in vitro model system for mTEC spheroid formation, in which cells adhere to each other, establishing a 3D structure. Results The comparisons between AIRE wild type (AIREWT) and AIRE KO (AIRE−/−) 3D mTEC spheroid formation showed that the absence of AIRE: i) disorganizes the 3D structure of mTEC spheroids, ii) increases the proportion of cells at the G0/G1 phase of the cell cycle, iii) increases the rate of mTEC apoptosis, iv) decreases the strength of mTEC-mTEC adhesion, v) promotes a differential regulation of mTEC classical surface markers, and vi) modulates genes encoding adhesion and other molecules. Conclusions Overall, the results show that AIRE influences the 3D structuring of mTECs when these cells begin the spheroid formation through controlling cell adhesion genes.
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Affiliation(s)
- Ana Carolina Monteleone-Cassiano
- Program of Basic and Applied Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil.,Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, 14049-900, Brazil
| | - Janaina A Dernowsek
- Institute for Energy and Nuclear Research, University of São Paulo, São Paulo, SP, Brazil
| | - Romario S Mascarenhas
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, 14049-900, Brazil
| | - Amanda Freire Assis
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, 14049-900, Brazil
| | - Dimitrius Pitol
- Department of Basic and Oral Biology, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | | | - Elza Tiemi Sakamoto-Hojo
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil.,Department of Biology, Faculty of Philosophy, Sciences and Letters at Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - João Paulo Mardegan Issa
- Department of Basic and Oral Biology, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Eduardo A Donadi
- Program of Basic and Applied Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil. .,Division of Clinical Immunology, Department of Medicine, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil.
| | - Geraldo Aleixo Passos
- Program of Basic and Applied Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil. .,Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, 14049-900, Brazil. .,Department of Basic and Oral Biology, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil. .,Center for Cell-Based Therapy in Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil. .,Laboratory of Genetics and Molecular Biology, Department of Basic and Oral Biology, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
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19
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Vobořil M, Březina J, Brabec T, Dobeš J, Ballek O, Dobešová M, Manning J, Blumberg RS, Filipp D. A model of preferential pairing between epithelial and dendritic cells in thymic antigen transfer. eLife 2022; 11:71578. [PMID: 35099391 PMCID: PMC8803313 DOI: 10.7554/elife.71578] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 12/22/2021] [Indexed: 12/22/2022] Open
Abstract
Medullary thymic epithelial cells (mTECs), which produce and present self-antigens, are essential for the establishment of central tolerance. Since mTEC numbers are limited, their function is complemented by thymic dendritic cells (DCs), which transfer mTEC-produced self-antigens via cooperative antigen transfer (CAT). While CAT is required for effective T cell selection, many aspects remain enigmatic. Given the recently described heterogeneity of mTECs and DCs, it is unclear whether the antigen acquisition from a particular TEC subset is mediated by preferential pairing with a specific subset of DCs. Using several relevant Cre-based mouse models that control for the expression of fluorescent proteins, we have found that, in regards to CAT, each subset of thymic DCs preferentially targets a distinct mTEC subset(s). Importantly, XCR1+-activated DC subset represented the most potent subset in CAT. Interestingly, thymic DCs can also acquire antigens from more than one mTEC, and of these, monocyte-derived dendritic cells (moDCs) were determined to be the most efficient. moDCs also represented the most potent DC subset in the acquisition of antigen from other DCs. These findings suggest a preferential pairing model for the distribution of mTEC-derived antigens among distinct populations of thymic DCs.
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Affiliation(s)
- Matouš Vobořil
- Laboratory of Immunobiology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jiří Březina
- Laboratory of Immunobiology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic.,Department of Cell Biology, Charles University, Faculty of Science, Charles University, Prague, Czech Republic
| | - Tomáš Brabec
- Laboratory of Immunobiology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jan Dobeš
- Laboratory of Immunobiology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic.,Department of Cell Biology, Charles University, Faculty of Science, Charles University, Prague, Czech Republic
| | - Ondřej Ballek
- Laboratory of Immunobiology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Martina Dobešová
- Laboratory of Immunobiology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jasper Manning
- Laboratory of Immunobiology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Richard S Blumberg
- Division of Gastroenterology, Hepatology, and Endoscopy, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, United States
| | - Dominik Filipp
- Laboratory of Immunobiology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
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20
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Kaiser C, Bradu A, Gamble N, Caldwell JA, Koh AS. AIRE in context: Leveraging chromatin plasticity to trigger ectopic gene expression. Immunol Rev 2022; 305:59-76. [PMID: 34545959 PMCID: PMC9250823 DOI: 10.1111/imr.13026] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Accepted: 08/26/2021] [Indexed: 12/22/2022]
Abstract
The emergence of antigen receptor diversity in clonotypic lymphocytes drove the evolution of a novel gene, Aire, that enabled the adaptive immune system to discriminate foreign invaders from self-constituents. AIRE functions in the epithelial cells of the thymus to express genes highly restricted to alternative cell lineages. This somatic plasticity facilitates the selection of a balanced repertoire of T cells that protects the host from harmful self-reactive clones, yet maintains a wide range of affinities for virtually any foreign antigen. Here, we review the latest understanding of AIRE's molecular actions with a focus on its interplay with chromatin. We argue that AIRE is a multi-valent chromatin effector that acts late in the transcription cycle to modulate the activity of previously poised non-coding regulatory elements of tissue-specific genes. We postulate a role for chromatin instability-caused in part by ATP-dependent chromatin remodeling-that variably sets the scope of the accessible landscape on which AIRE can act. We highlight AIRE's intrinsic repressive function and its relevance in providing feedback control. We synthesize these recent advances into a putative model for the mechanistic modes by which AIRE triggers ectopic transcription for immune repertoire selection.
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Affiliation(s)
- Caroline Kaiser
- Department of Pathology, University of Chicago, Chicago, Illinois, USA
- Department of Human Genetics, University of Chicago, Chicago, Illinois, USA
| | - Alexandra Bradu
- Department of Pathology, University of Chicago, Chicago, Illinois, USA
| | - Noah Gamble
- Department of Pathology, University of Chicago, Chicago, Illinois, USA
- Graduate Program in Biophysical Sciences, University of Chicago, Chicago, Illinois, USA
| | - Jason A. Caldwell
- Department of Pathology, University of Chicago, Chicago, Illinois, USA
| | - Andrew S. Koh
- Department of Pathology, University of Chicago, Chicago, Illinois, USA
- Institute for Biophysical Dynamics, University of Chicago, Chicago, Illinois, USA
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21
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Haunerdinger V, Moccia MD, Opitz L, Vavassori S, Dave H, Hauri-Hohl MM. Novel Combination of Surface Markers for the Reliable and Comprehensive Identification of Human Thymic Epithelial Cells by Flow Cytometry: Quantitation and Transcriptional Characterization of Thymic Stroma in a Pediatric Cohort. Front Immunol 2021; 12:740047. [PMID: 34659232 PMCID: PMC8514761 DOI: 10.3389/fimmu.2021.740047] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 09/14/2021] [Indexed: 12/12/2022] Open
Abstract
Thymic epithelial cells (TECs) are essential in supporting the development of mature T cells from hematopoietic progenitor cells and facilitate their lineage-commitment, proliferation, T-cell receptor repertoire selection and maturation. While animal model systems have greatly aided in elucidating the contribution of stromal cells to these intricate processes, human tissue has been more difficult to study, partly due to a lack of suitable surface markers comprehensively defining human TECs. Here, we conducted a flow cytometry based surface marker screen to reliably identify and quantify human TECs and delineate medullary from cortical subsets. These findings were validated by transcriptomic and histologic means. The combination of EpCAM, podoplanin (pdpn), CD49f and CD200 comprehensively identified human TECs and not only allowed their reliable distinction in medullary and cortical subsets but also their detailed quantitation. Transcriptomic profiling of each subset in comparison to fibroblasts and endothelial cells confirmed the identity of the different stromal cell subsets sorted according to the proposed strategy. Our dataset not only demonstrated transcriptional similarities between TEC and cells of mesenchymal origin but furthermore revealed a subset-specific distribution of a specific set of extracellular matrix-related genes in TECs. This indicates that TECs significantly contribute to the distinct compartmentalization - and thus function - of the human thymus. We applied the strategy to quantify TEC subsets in 31 immunologically healthy children, which revealed sex-specific differences of TEC composition early in life. As the distribution of mature CD4- or CD8-single-positive thymocytes was correspondingly altered, the composition of the thymic epithelial compartment may directly impact on the CD4-CD8-lineage choice of thymocytes. We prove that the plain, reliable strategy proposed here to comprehensively identify human TEC subpopulations by flow cytometry based on surface marker expression is suitable to determine their frequency and phenotype in health and disease and allows sorting of live cells for downstream analysis. Its use reaches from a reliable diagnostic tool for thymic biopsies to improved phenotypic characterization of thymic grafts intended for therapeutic use.
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Affiliation(s)
- Veronika Haunerdinger
- Division of Stem Cell Transplantation and Children's Research Center, University Children's Hospital, Zurich, Switzerland
| | - Maria Domenica Moccia
- Functional Genomics Center Zurich, Swiss Federal Institute of Technology and University of Zurich, Zurich, Switzerland
| | - Lennart Opitz
- Functional Genomics Center Zurich, Swiss Federal Institute of Technology and University of Zurich, Zurich, Switzerland
| | - Stefano Vavassori
- Division of Immunology and Children's Research Center, University Children's Hospital, Pediatric Immunology, Zurich, Switzerland
| | - Hitendu Dave
- Division of Congenital Cardiovascular Surgery, University Children's Hospital and Children's Research Centre, Zurich, Switzerland
| | - Mathias M Hauri-Hohl
- Division of Stem Cell Transplantation and Children's Research Center, University Children's Hospital, Zurich, Switzerland
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22
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Bansal K, Michelson DA, Ramirez RN, Viny AD, Levine RL, Benoist C, Mathis D. Aire regulates chromatin looping by evicting CTCF from domain boundaries and favoring accumulation of cohesin on superenhancers. Proc Natl Acad Sci U S A 2021; 118:e2110991118. [PMID: 34518235 PMCID: PMC8463806 DOI: 10.1073/pnas.2110991118] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2021] [Indexed: 11/18/2022] Open
Abstract
Aire controls immunological tolerance by driving promiscuous expression of a large swath of the genome in medullary thymic epithelial cells (mTECs). Its molecular mechanism remains enigmatic. High-resolution chromosome-conformation capture (Hi-C) experiments on ex vivo mTECs revealed Aire to have a widespread impact on higher-order chromatin structure, disfavoring architectural loops while favoring transcriptional loops. In the presence of Aire, cohesin complexes concentrated on superenhancers together with mediator complexes, while the CCCTC-binding factor (CTCF) was relatively depleted from structural domain boundaries. In particular, Aire associated with the cohesin loader, NIPBL, strengthening this factor's affiliation with cohesin's enzymatic subunits. mTEC transcripts up-regulated in the presence of Aire corresponded closely to those down-regulated in the absence of one of the cohesin subunits, SA-2. A mechanistic model incorporating these findings explains many of the unusual features of Aire's impact on mTEC transcription, providing molecular insight into tolerance induction.
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Affiliation(s)
- Kushagra Bansal
- Department of Immunology, Harvard Medical School, Boston, MA 02115
- Evergrande Center for Immunologic Diseases, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560 064, India
| | - Daniel A Michelson
- Department of Immunology, Harvard Medical School, Boston, MA 02115
- Evergrande Center for Immunologic Diseases, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115
| | - Ricardo N Ramirez
- Department of Immunology, Harvard Medical School, Boston, MA 02115
- Evergrande Center for Immunologic Diseases, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115
| | - Aaron D Viny
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065
- Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY 10065
- Leukemia Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY 10065
- Center for Epigenetics Research, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - Ross L Levine
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065
- Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY 10065
- Leukemia Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY 10065
- Center for Epigenetics Research, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - Christophe Benoist
- Department of Immunology, Harvard Medical School, Boston, MA 02115;
- Evergrande Center for Immunologic Diseases, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115
| | - Diane Mathis
- Department of Immunology, Harvard Medical School, Boston, MA 02115;
- Evergrande Center for Immunologic Diseases, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115
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23
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Barthlott T, Handel AE, Teh HY, Wirasinha RC, Hafen K, Žuklys S, Roch B, Orkin SH, de Villartay JP, Daley SR, Holländer GA. Indispensable epigenetic control of thymic epithelial cell development and function by polycomb repressive complex 2. Nat Commun 2021; 12:3933. [PMID: 34168132 PMCID: PMC8225857 DOI: 10.1038/s41467-021-24158-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 05/31/2021] [Indexed: 12/11/2022] Open
Abstract
Thymic T cell development and T cell receptor repertoire selection are dependent on essential molecular cues provided by thymic epithelial cells (TEC). TEC development and function are regulated by their epigenetic landscape, in which the repressive H3K27me3 epigenetic marks are catalyzed by polycomb repressive complex 2 (PRC2). Here we show that a TEC-targeted deficiency of PRC2 function results in a hypoplastic thymus with reduced ability to express antigens and select a normal repertoire of T cells. The absence of PRC2 activity reveals a transcriptomically distinct medullary TEC lineage that incompletely off-sets the shortage of canonically-derived medullary TEC whereas cortical TEC numbers remain unchanged. This alternative TEC development is associated with the generation of reduced TCR diversity. Hence, normal PRC2 activity and placement of H3K27me3 marks are required for TEC lineage differentiation and function and, in their absence, the thymus is unable to compensate for the loss of a normal TEC scaffold.
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Affiliation(s)
- Thomas Barthlott
- Department of Biomedicine and University Children's Hospital of Basel, University of Basel, Basel, Switzerland
| | - Adam E Handel
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Hong Ying Teh
- Department of Biomedicine and University Children's Hospital of Basel, University of Basel, Basel, Switzerland
| | - Rushika C Wirasinha
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Melbourne, VIC, Australia
| | - Katrin Hafen
- Department of Biomedicine and University Children's Hospital of Basel, University of Basel, Basel, Switzerland
| | - Saulius Žuklys
- Department of Biomedicine and University Children's Hospital of Basel, University of Basel, Basel, Switzerland
| | - Benoit Roch
- Genome Dynamics in the Immune System Laboratory, INSERM UMR 1163, Université de Paris, Imagine Institute, Paris, France
| | - Stuart H Orkin
- Department of Pediatric Oncology, Dana-Farber Cancer Institute and Division of Hematology/Oncology, Boston Children's Hospital, Harvard Stem Cell Institute, Harvard Medical School, and Howard Hughes Medical Institute, Boston, MA, USA
| | - Jean-Pierre de Villartay
- Genome Dynamics in the Immune System Laboratory, INSERM UMR 1163, Université de Paris, Imagine Institute, Paris, France
| | - Stephen R Daley
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Melbourne, VIC, Australia
- School of Health and Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Georg A Holländer
- Department of Biomedicine and University Children's Hospital of Basel, University of Basel, Basel, Switzerland.
- Department of Paediatrics and the Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK.
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24
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Perniola R, Fierabracci A, Falorni A. Autoimmune Addison's Disease as Part of the Autoimmune Polyglandular Syndrome Type 1: Historical Overview and Current Evidence. Front Immunol 2021; 12:606860. [PMID: 33717087 PMCID: PMC7953157 DOI: 10.3389/fimmu.2021.606860] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 01/25/2021] [Indexed: 12/11/2022] Open
Abstract
The autoimmune polyglandular syndrome type 1 (APS1) is caused by pathogenic variants of the autoimmune regulator (AIRE) gene, located in the chromosomal region 21q22.3. The related protein, AIRE, enhances thymic self-representation and immune self-tolerance by localization to chromatin and anchorage to multimolecular complexes involved in the initiation and post-initiation events of tissue-specific antigen-encoding gene transcription. Once synthesized, the self-antigens are presented to, and cause deletion of, the self-reactive thymocyte clones. The clinical diagnosis of APS1 is based on the classic triad idiopathic hypoparathyroidism (HPT)—chronic mucocutaneous candidiasis—autoimmune Addison's disease (AAD), though new criteria based on early non-endocrine manifestations have been proposed. HPT is in most cases the first endocrine component of the syndrome; however, APS1-associated AAD has received the most accurate biochemical, clinical, and immunological characterization. Here is a comprehensive review of the studies on APS1-associated AAD from initial case reports to the most recent scientific findings.
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Affiliation(s)
- Roberto Perniola
- Department of Pediatrics-Neonatal Intensive Care, V. Fazzi Hospital, ASL LE, Lecce, Italy
| | - Alessandra Fierabracci
- Infectivology and Clinical Trials Research Department, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Alberto Falorni
- Section of Internal Medicine and Endocrinological and Metabolic Sciences, Department of Medicine, University of Perugia, Perugia, Italy
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25
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Xydia M, Rahbari R, Ruggiero E, Macaulay I, Tarabichi M, Lohmayer R, Wilkening S, Michels T, Brown D, Vanuytven S, Mastitskaya S, Laidlaw S, Grabe N, Pritsch M, Fronza R, Hexel K, Schmitt S, Müller-Steinhardt M, Halama N, Domschke C, Schmidt M, von Kalle C, Schütz F, Voet T, Beckhove P. Common clonal origin of conventional T cells and induced regulatory T cells in breast cancer patients. Nat Commun 2021; 12:1119. [PMID: 33602930 PMCID: PMC7893042 DOI: 10.1038/s41467-021-21297-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 12/11/2020] [Indexed: 02/06/2023] Open
Abstract
Regulatory CD4+ T cells (Treg) prevent tumor clearance by conventional T cells (Tconv) comprising a major obstacle of cancer immune-surveillance. Hitherto, the mechanisms of Treg repertoire formation in human cancers remain largely unclear. Here, we analyze Treg clonal origin in breast cancer patients using T-Cell Receptor and single-cell transcriptome sequencing. While Treg in peripheral blood and breast tumors are clonally distinct, Tconv clones, including tumor-antigen reactive effectors (Teff), are detected in both compartments. Tumor-infiltrating CD4+ cells accumulate into distinct transcriptome clusters, including early activated Tconv, uncommitted Teff, Th1 Teff, suppressive Treg and pro-tumorigenic Treg. Trajectory analysis suggests early activated Tconv differentiation either into Th1 Teff or into suppressive and pro-tumorigenic Treg. Importantly, Tconv, activated Tconv and Treg share highly-expanded clones contributing up to 65% of intratumoral Treg. Here we show that Treg in human breast cancer may considerably stem from antigen-experienced Tconv converting into secondary induced Treg through intratumoral activation.
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Affiliation(s)
- Maria Xydia
- RCI Regensburg Centre for Interventional Immunology, University and Department of Hematology/Oncology, University Medical Centre of Regensburg, Regensburg, Germany.
- Translational Immunology Department, German Cancer Research Centre, Heidelberg, Germany.
| | - Raheleh Rahbari
- The Cancer, Ageing and Somatic Mutation Program, Wellcome Sanger Institute, Hinxton, UK
| | - Eliana Ruggiero
- Translational Oncology Department, National Centre for Tumor Diseases and German Cancer Research Centre, Heidelberg, Germany
| | - Iain Macaulay
- The Cancer, Ageing and Somatic Mutation Program, Wellcome Sanger Institute, Hinxton, UK
- Technical Development, Earlham Institute, Norwich, UK
| | - Maxime Tarabichi
- The Cancer, Ageing and Somatic Mutation Program, Wellcome Sanger Institute, Hinxton, UK
- The Francis Crick Institute, London, UK
| | - Robert Lohmayer
- RCI Regensburg Centre for Interventional Immunology, University and Department of Hematology/Oncology, University Medical Centre of Regensburg, Regensburg, Germany
- Institute for Theoretical Physics, University of Regensburg, Regensburg, Germany
| | - Stefan Wilkening
- Translational Oncology Department, National Centre for Tumor Diseases and German Cancer Research Centre, Heidelberg, Germany
| | - Tillmann Michels
- RCI Regensburg Centre for Interventional Immunology, University and Department of Hematology/Oncology, University Medical Centre of Regensburg, Regensburg, Germany
| | - Daniel Brown
- Department of Human Genetics, University of Leuven, KU Leuven, Leuven, Belgium
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
| | - Sebastiaan Vanuytven
- The Francis Crick Institute, London, UK
- Department of Human Genetics, University of Leuven, KU Leuven, Leuven, Belgium
| | - Svetlana Mastitskaya
- Medical Oncology Department, National Centre for Tumor Diseases, Heidelberg, Germany
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Sean Laidlaw
- The Cancer, Ageing and Somatic Mutation Program, Wellcome Sanger Institute, Hinxton, UK
| | - Niels Grabe
- Medical Oncology Department, National Centre for Tumor Diseases, Heidelberg, Germany
- Hamamatsu Tissue Imaging and Analysis Centre, BIOQUANT, University of Heidelberg, Heidelberg, Germany
| | - Maria Pritsch
- Translational Immunology Department, German Cancer Research Centre, Heidelberg, Germany
| | - Raffaele Fronza
- Translational Oncology Department, National Centre for Tumor Diseases and German Cancer Research Centre, Heidelberg, Germany
| | - Klaus Hexel
- Flow Cytometry Core Facility, German Cancer Research Centre, Heidelberg, Germany
| | - Steffen Schmitt
- Flow Cytometry Core Facility, German Cancer Research Centre, Heidelberg, Germany
| | - Michael Müller-Steinhardt
- German Red Cross (DRK Blood Donation Service in Baden-Württemberg-Hessen) and Institute for Transfusion Medicine and Immunology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Niels Halama
- Medical Oncology Department, National Centre for Tumor Diseases, Heidelberg, Germany
- Hamamatsu Tissue Imaging and Analysis Centre, BIOQUANT, University of Heidelberg, Heidelberg, Germany
| | - Christoph Domschke
- Department of Gynecology and Obstetrics, University Hospital of Heidelberg, Heidelberg, Germany
| | - Manfred Schmidt
- Translational Oncology Department, National Centre for Tumor Diseases and German Cancer Research Centre, Heidelberg, Germany
| | - Christof von Kalle
- Translational Oncology Department, National Centre for Tumor Diseases and German Cancer Research Centre, Heidelberg, Germany
- Clinical Study Centre, Charité/BIH, Berlin, Germany
| | - Florian Schütz
- Department of Gynecology and Obstetrics, University Hospital of Heidelberg, Heidelberg, Germany
| | - Thierry Voet
- The Cancer, Ageing and Somatic Mutation Program, Wellcome Sanger Institute, Hinxton, UK
- Department of Human Genetics, University of Leuven, KU Leuven, Leuven, Belgium
| | - Philipp Beckhove
- RCI Regensburg Centre for Interventional Immunology, University and Department of Hematology/Oncology, University Medical Centre of Regensburg, Regensburg, Germany.
- Translational Immunology Department, German Cancer Research Centre, Heidelberg, Germany.
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Marx A, Yamada Y, Simon-Keller K, Schalke B, Willcox N, Ströbel P, Weis CA. Thymus and autoimmunity. Semin Immunopathol 2021; 43:45-64. [PMID: 33537838 PMCID: PMC7925479 DOI: 10.1007/s00281-021-00842-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 01/12/2021] [Indexed: 12/19/2022]
Abstract
The thymus prevents autoimmune diseases through mechanisms that operate in the cortex and medulla, comprising positive and negative selection and the generation of regulatory T-cells (Tregs). Egress from the thymus through the perivascular space (PVS) to the blood is another possible checkpoint, as shown by some autoimmune/immunodeficiency syndromes. In polygenic autoimmune diseases, subtle thymic dysfunctions may compound genetic, hormonal and environmental cues. Here, we cover (a) tolerance-inducing cell types, whether thymic epithelial or tuft cells, or dendritic, B- or thymic myoid cells; (b) tolerance-inducing mechanisms and their failure in relation to thymic anatomic compartments, and with special emphasis on human monogenic and polygenic autoimmune diseases and the related thymic pathologies, if known; (c) polymorphisms and mutations of tolerance-related genes with an impact on positive selection (e.g. the gene encoding the thymoproteasome-specific subunit, PSMB11), promiscuous gene expression (e.g. AIRE, PRKDC, FEZF2, CHD4), Treg development (e.g. SATB1, FOXP3), T-cell migration (e.g. TAGAP) and egress from the thymus (e.g. MTS1, CORO1A); (d) myasthenia gravis as the prototypic outcome of an inflamed or disordered neoplastic ‘sick thymus’.
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Affiliation(s)
- Alexander Marx
- Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany.
| | - Yosuke Yamada
- Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
- Department of Diagnostic Pathology, Kyoto University Hospital, Kyoto, 606-8507, Japan
| | - Katja Simon-Keller
- Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Berthold Schalke
- Department of Neurology, Bezirkskrankenhaus, University of Regensburg, 93042, Regensburg, Germany
| | - Nick Willcox
- Neurosciences Group, Nuffield Department of Clinical Neurology, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Philipp Ströbel
- Institute of Pathology, University Medical Center Göttingen, University of Göttigen, 37075, Göttingen, Germany
| | - Cleo-Aron Weis
- Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
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27
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Thymic origins of autoimmunity-lessons from inborn errors of immunity. Semin Immunopathol 2021; 43:65-83. [PMID: 33532929 PMCID: PMC7925499 DOI: 10.1007/s00281-020-00835-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 12/22/2020] [Indexed: 12/16/2022]
Abstract
During their intrathymic development, nascent T cells are empowered to protect against pathogens and to be operative for a life-long acceptance of self. While autoreactive effector T (Teff) cell progenitors are eliminated by clonal deletion, the intrathymic mechanisms by which thymic regulatory T cell (tTreg) progenitors maintain specificity for self-antigens but escape deletion to exert their regulatory functions are less well understood. Both tTreg and Teff development and selection result from finely coordinated interactions between their clonotypic T cell receptors (TCR) and peptide/MHC complexes expressed by antigen-presenting cells, such as thymic epithelial cells and thymic dendritic cells. tTreg function is dependent on expression of the FOXP3 transcription factor, and induction of FOXP3 gene expression by tTreg occurs during their thymic development, particularly within the thymic medulla. While initial expression of FOXP3 is downstream of TCR activation, constitutive expression is fixed by interactions with various transcription factors that are regulated by other extracellular signals like TCR and cytokines, leading to epigenetic modification of the FOXP3 gene. Most of the understanding of the molecular events underlying tTreg generation is based on studies of murine models, whereas gaining similar insight in the human system has been very challenging. In this review, we will elucidate how inborn errors of immunity illuminate the critical non-redundant roles of certain molecules during tTreg development, shedding light on how their abnormal development and function cause well-defined diseases that manifest with autoimmunity alone or are associated with states of immune deficiency and autoinflammation.
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Wells KL, Miller CN, Gschwind AR, Wei W, Phipps JD, Anderson MS, Steinmetz LM. Combined transient ablation and single-cell RNA-sequencing reveals the development of medullary thymic epithelial cells. eLife 2020; 9:60188. [PMID: 33226342 PMCID: PMC7771965 DOI: 10.7554/elife.60188] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 11/21/2020] [Indexed: 12/14/2022] Open
Abstract
Medullary thymic epithelial cells (mTECs) play a critical role in central immune tolerance by mediating negative selection of autoreactive T cells through the collective expression of the peripheral self-antigen compartment, including tissue-specific antigens (TSAs). Recent work has shown that gene-expression patterns within the mTEC compartment are heterogenous and include multiple differentiated cell states. To further define mTEC development and medullary epithelial lineage relationships, we combined lineage tracing and recovery from transient in vivo mTEC ablation with single-cell RNA-sequencing in Mus musculus. The combination of bioinformatic and experimental approaches revealed a non-stem transit-amplifying population of cycling mTECs that preceded Aire expression. We propose a branching model of mTEC development wherein a heterogeneous pool of transit-amplifying cells gives rise to Aire- and Ccl21a-expressing mTEC subsets. We further use experimental techniques to show that within the Aire-expressing developmental branch, TSA expression peaked as Aire expression decreased, implying Aire expression must be established before TSA expression can occur. Collectively, these data provide a roadmap of mTEC development and demonstrate the power of combinatorial approaches leveraging both in vivo models and high-dimensional datasets. Specialized cells in the immune system known as T cells protect the body from infection by destroying disease-causing microbes, such as bacteria or viruses. T cells use proteins on their surface called receptors to stick to infectious microbes and remove them from the body. Some newly developed T-cells, however, contain receptors that recognize and bind to cells that belong in the body. If these faulty T cells are released, they can attack healthy tissues and cause an autoimmune disease. After a new T cell is developed, it gets carried to a gland in the chest known as the thymus. Cells in the thymus called mTECs screen T cells for receptors that may bind to the body’s tissues. mTECs do this by presenting T cells with proteins that are commonly found on the surface of healthy cells in the body. If a T cell recognizes any of these ‘tissue specific proteins’, it is destroyed or given a new role in the body. Some faulty T cells, however, still manage to evade detection. One way to uncover why this might happen is to investigate how mTECs develop. Previous work showed that mTECs transition through various stages before reaching their final form. However, the order in which these events occur remained unclear. To gain a better understanding of these developmental steps, Wells, Miller et al. extracted mTECs from the thymus of mice and analyzed the genetic make-up of individual cells. This uncovered a missing link in mTEC development: a new type of cell that is the immediate predecessor of the final mTEC. These ‘predecessor’ cells were actively growing, highlighting that mTECs can be constantly generated in the body. By probing the genes that generate tissue-specific proteins in mTECs, Wells, Miller et al. revealed that these proteins were only produced for short periods and in the late stages of mTEC development. These findings contribute to our understanding of how mTECs develop to screen T cells. Mapping these developmental stages will make it easier to identify when faulty T cells are able to evade mTECs. This will lead to earlier detection of autoimmune diseases which could result in better treatments.
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Affiliation(s)
- Kristen L Wells
- Department of Genetics, Stanford University School of Medicine, Stanford, United States
| | - Corey N Miller
- Diabetes Center, University of California, San Francisco, San Francisco, United States.,Department of Medicine, University of California San Francisco, San Francisco, United States
| | - Andreas R Gschwind
- Department of Genetics, Stanford University School of Medicine, Stanford, United States
| | - Wu Wei
- Stanford Genome Technology Center, Stanford University, Palo Alto, United States
| | - Jonah D Phipps
- Diabetes Center, University of California, San Francisco, San Francisco, United States.,Department of Medicine, University of California San Francisco, San Francisco, United States
| | - Mark S Anderson
- Diabetes Center, University of California, San Francisco, San Francisco, United States.,Department of Medicine, University of California San Francisco, San Francisco, United States
| | - Lars M Steinmetz
- Department of Genetics, Stanford University School of Medicine, Stanford, United States.,Stanford Genome Technology Center, Stanford University, Palo Alto, United States.,Genome Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
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29
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Scarsella L, Pollmann R, Amber KT. Autoreactive T cells in pemphigus: perpetrator and target. Ital J Dermatol Venerol 2020; 156:124-133. [PMID: 33179878 DOI: 10.23736/s2784-8671.20.06706-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Pemphigus vulgaris (PV) is an autoimmune blistering disease, in which autoantibodies against epidermal cadherins, such as desmoglein (Dsg)1 and Dsg3, lead to the development of blisters and erosions on the skin and mucous membranes. Autoreactive CD4+ T cells are essential for the induction and perpetuation of the disease by interaction with B cells producing autoantibodies. PV has a strong genetic association with certain human leucocyte antigen (HLA) alleles with HLA-DRB1*04:02 and LA-DQB1*05:03 being the most prevalent in patients. Recently, genome-wide association studies have provided a new approach to identify single nucleotide polymorphisms, alongside the known association with HLA alleles. Loss of tolerance against Dsgs and other autoantigens is a critical event in the pathogenesis of PV. Epitope spreading contributes to the progression of PV, leading to an extension of the Dsg-specific autoimmune response to other molecular epitopes of autoantigens, such as desmocollins or muscarinic receptors. Alterations in CD4+CD25+ FoxP3+ regulatory T cells are thought to contribute to the development of PV representing a suitable target for therapeutic interventions. Several CD4+ T-cell subsets and cytokines are involved in the pathogenesis of PV, while Th2 cells are the extensively studied population. Recently, other T cell subsets like T follicular helper cells and Th17 have gained attention as new potential players in PV pathogenesis. The involvement of local autoantibody production in the lesional skin of PV patients in tertiary lymphoid organs is currently discussed but not yet clarified. In this study, we reviewed the current knowledge about the development, characteristics and function of autoreactive T cells in pemphigus and present current new T cell-targeted therapeutic approaches.
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Affiliation(s)
- Luca Scarsella
- Department of Dermatology and Allergology, Philipps University, Marburg, Germany
| | - Robert Pollmann
- Department of Dermatology and Allergology, Philipps University, Marburg, Germany -
| | - Kyle T Amber
- Department of Dermatology, University of Illinois, Chicago, IL, USA
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30
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Rausch MP, Meador LR, Metzger TC, Li H, Qiu S, Anderson MS, Hastings KT. GILT in Thymic Epithelial Cells Facilitates Central CD4 T Cell Tolerance to a Tissue-Restricted, Melanoma-Associated Self-Antigen. THE JOURNAL OF IMMUNOLOGY 2020; 204:2877-2886. [PMID: 32269095 DOI: 10.4049/jimmunol.1900523] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 03/23/2020] [Indexed: 12/17/2022]
Abstract
Central tolerance prevents autoimmunity, but also limits T cell responses to potentially immunodominant tumor epitopes with limited expression in healthy tissues. In peripheral APCs, γ-IFN-inducible lysosomal thiol reductase (GILT) is critical for MHC class II-restricted presentation of disulfide bond-containing proteins, including the self-antigen and melanoma Ag tyrosinase-related protein 1 (TRP1). The role of GILT in thymic Ag processing and generation of central tolerance has not been investigated. We found that GILT enhanced the negative selection of TRP1-specific thymocytes in mice. GILT expression was enriched in thymic APCs capable of mediating deletion, namely medullary thymic epithelial cells (mTECs) and dendritic cells, whereas TRP1 expression was restricted solely to mTECs. GILT facilitated MHC class II-restricted presentation of endogenous TRP1 by pooled thymic APCs. Using bone marrow chimeras, GILT expression in thymic epithelial cells (TECs), but not hematopoietic cells, was sufficient for complete deletion of TRP1-specific thymocytes. An increased frequency of TRP1-specific regulatory T (Treg) cells was present in chimeras with increased deletion of TRP1-specific thymocytes. Only chimeras that lacked GILT in both TECs and hematopoietic cells had a high conventional T/Treg cell ratio and were protected from melanoma challenge. Thus, GILT expression in thymic APCs, and mTECs in particular, preferentially facilitates MHC class II-restricted presentation, negative selection, and increased Treg cells, resulting in a diminished antitumor response to a tissue-restricted, melanoma-associated self-antigen.
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Affiliation(s)
- Matthew P Rausch
- Department of Basic Medical Sciences, University of Arizona, Phoenix, AZ 85004; and
| | - Lydia R Meador
- Department of Basic Medical Sciences, University of Arizona, Phoenix, AZ 85004; and
| | - Todd C Metzger
- Diabetes Center, University of California, San Francisco, San Francisco, CA 94143
| | - Handong Li
- Department of Basic Medical Sciences, University of Arizona, Phoenix, AZ 85004; and
| | - Shenfeng Qiu
- Department of Basic Medical Sciences, University of Arizona, Phoenix, AZ 85004; and
| | - Mark S Anderson
- Diabetes Center, University of California, San Francisco, San Francisco, CA 94143
| | - K Taraszka Hastings
- Department of Basic Medical Sciences, University of Arizona, Phoenix, AZ 85004; and
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31
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Nicholson LB, Blyuss KB, Fatehi F. Quantifying the Role of Stochasticity in the Development of Autoimmune Disease. Cells 2020; 9:E860. [PMID: 32252308 PMCID: PMC7226790 DOI: 10.3390/cells9040860] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 03/11/2020] [Accepted: 03/26/2020] [Indexed: 12/11/2022] Open
Abstract
In this paper, we propose and analyse a mathematical model for the onset and development of autoimmune disease, with particular attention to stochastic effects in the dynamics. Stability analysis yields parameter regions associated with normal cell homeostasis, or sustained periodic oscillations. Variance of these oscillations and the effects of stochastic amplification are also explored. Theoretical results are complemented by experiments, in which experimental autoimmune uveoretinitis (EAU) was induced in B10.RIII and C57BL/6 mice. For both cases, we discuss peculiarities of disease development, the levels of variation in T cell populations in a population of genetically identical organisms, as well as a comparison with model outputs.
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Affiliation(s)
- Lindsay B. Nicholson
- School of Cellular and Molecular Medicine & School of Clinical Sciences, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | | | - Farzad Fatehi
- Department of Mathematics, University of York, York YO10 5DD, UK;
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32
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Abstract
Foxp3-expressing CD4+ regulatory T (Treg) cells play key roles in the prevention of autoimmunity and the maintenance of immune homeostasis and represent a major barrier to the induction of robust antitumor immune responses. Thus, a clear understanding of the mechanisms coordinating Treg cell differentiation is crucial for understanding numerous facets of health and disease and for developing approaches to modulate Treg cells for clinical benefit. Here, we discuss current knowledge of the signals that coordinate Treg cell development, the antigen-presenting cell types that direct Treg cell selection, and the nature of endogenous Treg cell ligands, focusing on evidence from studies in mice. We also highlight recent advances in this area and identify key unanswered questions.
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Affiliation(s)
- Peter A Savage
- Department of Pathology, University of Chicago, Chicago, Illinois 60637, USA; , ,
| | - David E J Klawon
- Department of Pathology, University of Chicago, Chicago, Illinois 60637, USA; , ,
| | - Christine H Miller
- Department of Pathology, University of Chicago, Chicago, Illinois 60637, USA; , ,
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Dhalla F, Baran‐Gale J, Maio S, Chappell L, Holländer GA, Ponting CP. Biologically indeterminate yet ordered promiscuous gene expression in single medullary thymic epithelial cells. EMBO J 2020; 39:e101828. [PMID: 31657037 PMCID: PMC6939203 DOI: 10.15252/embj.2019101828] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 09/20/2019] [Accepted: 09/25/2019] [Indexed: 12/12/2022] Open
Abstract
To induce central T-cell tolerance, medullary thymic epithelial cells (mTEC) collectively express most protein-coding genes, thereby presenting an extensive library of tissue-restricted antigens (TRAs). To resolve mTEC diversity and whether promiscuous gene expression (PGE) is stochastic or coordinated, we sequenced transcriptomes of 6,894 single mTEC, enriching for 1,795 rare cells expressing either of two TRAs, TSPAN8 or GP2. Transcriptional heterogeneity allowed partitioning of mTEC into 15 reproducible subpopulations representing distinct maturational trajectories, stages and subtypes, including novel mTEC subsets, such as chemokine-expressing and ciliated TEC, which warrant further characterisation. Unexpectedly, 50 modules of genes were robustly defined each showing patterns of co-expression within individual cells, which were mainly not explicable by chromosomal location, biological pathway or tissue specificity. Further, TSPAN8+ and GP2+ mTEC were randomly dispersed within thymic medullary islands. Consequently, these data support observations that PGE exhibits ordered co-expression, although mechanisms underlying this instruction remain biologically indeterminate. Ordered co-expression and random spatial distribution of a diverse range of TRAs likely enhance their presentation and encounter with passing thymocytes, while maintaining mTEC identity.
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Affiliation(s)
- Fatima Dhalla
- Weatherall Institute of Molecular MedicineUniversity of OxfordOxfordUK
| | | | - Stefano Maio
- Weatherall Institute of Molecular MedicineUniversity of OxfordOxfordUK
| | | | - Georg A Holländer
- Weatherall Institute of Molecular MedicineUniversity of OxfordOxfordUK
| | - Chris P Ponting
- MRC Human Genetics UnitMRC IGMMThe University of EdinburghEdinburghUK
- Wellcome Sanger InstituteHinxtonUK
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34
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Pechelyulko AA, Tarakanova YN, Dmitriev DA, Massino YS, Kost VY, Rogozhin EA, Segal OL, Dmitriev AD. Comparative Analysis of the Efficiency of Chicken and Rabbit Antibodies in Competitive Enzyme Linked Immunoassay for the Detection of Bovine Beta-Casomorphin 7. APPL BIOCHEM MICRO+ 2019. [DOI: 10.1134/s0003683819060103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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35
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Abstract
The generation of a functional T cell repertoire in the thymus is mainly orchestrated by thymic epithelial cells (TECs), which provide developing T cells with cues for their navigation, proliferation, differentiation and survival. The TEC compartment has been segregated historically into two major populations of medullary TECs and cortical TECs, which differ in their anatomical localization, molecular characteristics and functional roles. However, recent studies have shown that TECs are highly heterogeneous and comprise multiple subpopulations with distinct molecular and functional characteristics, including tuft cell-like or corneocyte-like phenotypes. Here, we review the most recent advances in our understanding of TEC heterogeneity from a molecular, functional and developmental perspective. In particular, we highlight the key insights that were recently provided by single-cell genomic technologies and in vivo fate mapping and discuss them in the context of previously published data.
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36
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Lancaster JN, Thyagarajan HM, Srinivasan J, Li Y, Hu Z, Ehrlich LIR. Live-cell imaging reveals the relative contributions of antigen-presenting cell subsets to thymic central tolerance. Nat Commun 2019; 10:2220. [PMID: 31101805 PMCID: PMC6525199 DOI: 10.1038/s41467-019-09727-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 03/18/2019] [Indexed: 12/31/2022] Open
Abstract
Both medullary thymic epithelial cells (mTEC) and dendritic cells (DC) present tissue-restricted antigens (TRA) to thymocytes to induce central tolerance, but the relative contributions of these antigen-presenting cell (APC) subsets remain unresolved. Here we developed a two-photon microscopy approach to observe thymocytes interacting with intact APCs presenting TRAs. We find that mTECs and DCs cooperate extensively to induce tolerance, with their relative contributions regulated by the cellular form of the TRA and the class of major histocompatibility complex (MHC) on which antigen is presented. Even when TRA expression is restricted to mTECs, DCs still present self-antigens at least as frequently as mTECs. Notably, the DC subset cDC2 efficiently acquires secreted mTEC-derived TRAs for cross-presentation on MHC-I. By directly imaging interactions between thymocytes and APCs, while monitoring intracellular signaling, this study reveals that distinct DC subsets and AIRE+ mTECs contribute substantially to presentation of diverse self-antigens for establishing central tolerance.
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Affiliation(s)
- J N Lancaster
- Department of Molecular Biosciences, Institute of Cellular and Molecular Biology, The University of Texas at Austin, 100 E. 24th Street A5000, Austin, TX, 78712, USA
| | - H M Thyagarajan
- Department of Molecular Biosciences, Institute of Cellular and Molecular Biology, The University of Texas at Austin, 100 E. 24th Street A5000, Austin, TX, 78712, USA
| | - J Srinivasan
- Department of Molecular Biosciences, Institute of Cellular and Molecular Biology, The University of Texas at Austin, 100 E. 24th Street A5000, Austin, TX, 78712, USA
| | - Y Li
- Department of Molecular Biosciences, Institute of Cellular and Molecular Biology, The University of Texas at Austin, 100 E. 24th Street A5000, Austin, TX, 78712, USA
| | - Z Hu
- Department of Molecular Biosciences, Institute of Cellular and Molecular Biology, The University of Texas at Austin, 100 E. 24th Street A5000, Austin, TX, 78712, USA
| | - L I R Ehrlich
- Department of Molecular Biosciences, Institute of Cellular and Molecular Biology, The University of Texas at Austin, 100 E. 24th Street A5000, Austin, TX, 78712, USA.
- Livestrong Cancer Institutes, Dell Medical School, The University of Texas at Austin, Austin, TX, 78712, USA.
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Geenen V, Trussart C, Michaux H, Halouani A, Jaïdane H, Collée C, Renard C, Daukandt M, Ledent P, Martens H. The presentation of neuroendocrine self-peptides in the thymus: an essential event for individual life and vertebrate survival. Ann N Y Acad Sci 2019; 1455:113-125. [PMID: 31008523 PMCID: PMC6899491 DOI: 10.1111/nyas.14089] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 02/27/2019] [Accepted: 03/10/2019] [Indexed: 12/12/2022]
Abstract
Confirming Burnet's early hypothesis, elimination of self‐reactive T cells in the thymus was demonstrated in the late 1980s, and an important question immediately arose about the nature of the self‐peptides expressed in the thymus. Many genes encoding neuroendocrine‐related and tissue‐restricted antigens (TRAs) are transcribed in thymic epithelial cells (TECs). They are then processed for presentation by proteins of the major histocompatibility complex (MHC) expressed by TECs and thymic dendritic cells. MHC presentation of self‐peptides in the thymus programs self‐tolerance by two complementary mechanisms: (1) negative selection of self‐reactive “forbidden” T cell clones starting already in fetal life, and (2) generation of self‐specific thymic regulatory T lymphocytes (tTreg cells), mainly after birth. Many studies, including the discovery of the transcription factors autoimmune regulator (AIRE) and fasciculation and elongation protein zeta family zinc finger (FEZF2), have shown that a defect in thymus central self‐tolerance is the earliest event promoting autoimmunity. AIRE and FEZF2 control the level of transcription of many neuroendocrine self‐peptides and TRAs in the thymic epithelium. Furthermore, AIRE and FEZF2 mutations are associated with the development of autoimmunity in peripheral organs. The discovery of the intrathymic presentation of self‐peptides has revolutionized our knowledge of immunology and is opening novel avenues for prevention/treatment of autoimmunity.
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Affiliation(s)
- Vincent Geenen
- GIGA Institute, University of Liège, Liège-Sart Tilman, Belgium
| | | | - Hélène Michaux
- GIGA Institute, University of Liège, Liège-Sart Tilman, Belgium
| | - Aymen Halouani
- GIGA Institute, University of Liège, Liège-Sart Tilman, Belgium.,Faculty of Sciences and Faculty of Pharmacy, University of Tunis El Manar, Monastir, Tunisia
| | - Hela Jaïdane
- Faculty of Sciences and Faculty of Pharmacy, University of Tunis El Manar, Monastir, Tunisia
| | - Caroline Collée
- GIGA Institute, University of Liège, Liège-Sart Tilman, Belgium
| | - Chantal Renard
- GIGA Institute, University of Liège, Liège-Sart Tilman, Belgium
| | - Marc Daukandt
- X-Press Biologics, Industrial Park of Milmort, Liège, Belgium
| | - Philippe Ledent
- X-Press Biologics, Industrial Park of Milmort, Liège, Belgium
| | - Henri Martens
- GIGA Institute, University of Liège, Liège-Sart Tilman, Belgium
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38
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Morimoto J, Nishikawa Y, Kakimoto T, Furutani K, Kihara N, Matsumoto M, Tsuneyama K, Kozono Y, Kozono H, Hozumi K, Hosomichi K, Nishijima H, Matsumoto M. Aire Controls in Trans the Production of Medullary Thymic Epithelial Cells Expressing Ly-6C/Ly-6G. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2018; 201:3244-3257. [PMID: 30389776 DOI: 10.4049/jimmunol.1800950] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 09/27/2018] [Indexed: 11/19/2022]
Abstract
Medullary thymic epithelial cells (mTECs), which express a wide range of tissue-restricted Ags (TRAs), contribute to the establishment of self-tolerance by eliminating autoreactive T cells and/or inducing regulatory T cells. Aire controls a diverse set of TRAs within Aire-expressing cells by employing various transcriptional pathways. As Aire has a profound effect on transcriptomes of mTECs, including TRAs not only at the single-cell but also the population level, we suspected that Aire (Aire+ mTECs) might control the cellular composition of the thymic microenvironment. In this study, we confirmed that this is indeed the case by identifying a novel mTEC subset expressing Ly-6 family protein whose production was defective in Aire-deficient thymi. Reaggregated thymic organ culture experiments demonstrated that Aire did not induce the expression of Ly-6C/Ly-6G molecules from mTECs as Aire-dependent TRAs in a cell-intrinsic manner. Instead, Aire+ mTECs functioned in trans to maintain Ly-6C/Ly-6G+ mTECs. Thus, Aire not only controls TRA expression transcriptionally within the cell but also controls the overall composition of mTECs in a cell-extrinsic manner, thereby regulating the transcriptome from mTECs on a global scale.
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Affiliation(s)
- Junko Morimoto
- Division of Molecular Immunology, Institute for Enzyme Research, Tokushima University, Tokushima 770-8503, Japan
| | - Yumiko Nishikawa
- Division of Molecular Immunology, Institute for Enzyme Research, Tokushima University, Tokushima 770-8503, Japan
| | - Takumi Kakimoto
- Division of Molecular Immunology, Institute for Enzyme Research, Tokushima University, Tokushima 770-8503, Japan
- Student Lab, Tokushima University Faculty of Medicine, Tokushima 770-8503, Japan
| | - Kohei Furutani
- Division of Molecular Immunology, Institute for Enzyme Research, Tokushima University, Tokushima 770-8503, Japan
- Student Lab, Tokushima University Faculty of Medicine, Tokushima 770-8503, Japan
| | - Naoki Kihara
- Division of Molecular Immunology, Institute for Enzyme Research, Tokushima University, Tokushima 770-8503, Japan
- Student Lab, Tokushima University Faculty of Medicine, Tokushima 770-8503, Japan
| | - Minoru Matsumoto
- Division of Molecular Immunology, Institute for Enzyme Research, Tokushima University, Tokushima 770-8503, Japan
- Department of Molecular and Environmental Pathology, Institute of Biomedical Sciences, The University of Tokushima Graduate School, Tokushima 770-8503, Japan
| | - Koichi Tsuneyama
- Department of Molecular and Environmental Pathology, Institute of Biomedical Sciences, The University of Tokushima Graduate School, Tokushima 770-8503, Japan
| | - Yuko Kozono
- Research Institute for Biomedical Sciences, Tokyo University of Science, Chiba 278-0022, Japan
| | - Haruo Kozono
- Research Institute for Biomedical Sciences, Tokyo University of Science, Chiba 278-0022, Japan
| | - Katsuto Hozumi
- Department of Immunology, Tokai University School of Medicine, Isehara, Kanagawa 259-1193, Japan
| | - Kazuyoshi Hosomichi
- Department of Bioinformatics and Genomics, Graduate School of Medical Sciences, Kanazawa University, Ishikawa 920-0934, Japan; and
| | - Hitoshi Nishijima
- Division of Molecular Immunology, Institute for Enzyme Research, Tokushima University, Tokushima 770-8503, Japan
| | - Mitsuru Matsumoto
- Division of Molecular Immunology, Institute for Enzyme Research, Tokushima University, Tokushima 770-8503, Japan;
- Japan Agency for Medical Research and Development-Core Research for Evolutional Science and Technology, Tokyo 100-0004, Japan
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39
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Bekpen C, Xie C, Tautz D. Dealing with the adaptive immune system during de novo evolution of genes from intergenic sequences. BMC Evol Biol 2018; 18:121. [PMID: 30075701 PMCID: PMC6091031 DOI: 10.1186/s12862-018-1232-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 07/16/2018] [Indexed: 12/26/2022] Open
Abstract
Background The adaptive immune system of vertebrates has an extraordinary potential to sense and neutralize foreign antigens entering the body. De novo evolution of genes implies that the genome itself expresses novel antigens from intergenic sequences which could cause a problem with this immune system. Peptides from these novel proteins could be presented by the major histocompatibility complex (MHC) receptors to the cell surface and would be recognized as foreign. The respective cells would then be attacked and destroyed, or would cause inflammatory responses. Hence, de novo expressed peptides have to be introduced to the immune system as being self-peptides to avoid such autoimmune reactions. The regulation of the distinction between self and non-self starts during embryonic development, but continues late into adulthood. It is mostly mediated by specialized cells in the thymus, but can also be conveyed in peripheral tissues, such as the lymph nodes and the spleen. The self-antigens need to be exposed to the reactive T-cells, which requires the expression of the genes in the respective tissues. Since the initial activation of a promotor for new intergenic transcription of a de novo gene could occur in any tissue, we should expect that the evolutionary establishment of a de novo gene in animals with an adaptive immune system should also involve expression in at least one of the tissues that confer self-recognition. Results We have studied this question by analyzing the transcriptomes of multiple tissues from young mice in three closely related natural populations of the house mouse (M. m. domesticus). We find that new intergenic transcription occurs indeed mostly in only a single tissue. When a second tissue becomes involved, thymus and spleen are significantly overrepresented. Conclusions We conclude that the inclusion of de novo transcripts in the processes for the induction of self-tolerance is indeed an important step in the evolution of functional de novo genes in vertebrates. Electronic supplementary material The online version of this article (10.1186/s12862-018-1232-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Cemalettin Bekpen
- Max-Planck Institute for Evolutionary Biology, August-Thienemannstr. 2, 24306, Plön, Germany
| | - Chen Xie
- Max-Planck Institute for Evolutionary Biology, August-Thienemannstr. 2, 24306, Plön, Germany
| | - Diethard Tautz
- Max-Planck Institute for Evolutionary Biology, August-Thienemannstr. 2, 24306, Plön, Germany.
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40
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Villegas JA, Gradolatto A, Truffault F, Roussin R, Berrih-Aknin S, Le Panse R, Dragin N. Cultured Human Thymic-Derived Cells Display Medullary Thymic Epithelial Cell Phenotype and Functionality. Front Immunol 2018; 9:1663. [PMID: 30083154 PMCID: PMC6064927 DOI: 10.3389/fimmu.2018.01663] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 07/04/2018] [Indexed: 12/13/2022] Open
Abstract
Thymic epithelial cells are one of the main components of the thymic microenvironment required for T-cell development. In this work, we describe an efficient method free of enzymatic and Facs-sorted methods to culture human medullary thymic epithelial cells without affecting the cell phenotypic, physiologic and functional features. Human medulla thymic epithelial cells (mTECs) are obtained by culturing thymic biopsies explants. After 7 days of primo-culture, mTECs keep their ability to express key molecules involved in immune tolerance processes such as autoimmune regulator, tissue-specific antigens, chemokines, and cytokines. In addition, the cells sensor their cultured environment and consequently adjust their gene expression network. Therefore, we describe and provide a human mTEC model that may be used to test the effect of various molecules on thymic epithelial cell homeostasis and physiology. This method should allow the investigations of the specificities and the knowledge of human mTECs in normal or pathological conditions and therefore discontinue the extrapolations done on the murine models.
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Affiliation(s)
- José A Villegas
- INSERM, AIM, Center of Research in Myology, UMRS974, Sorbonne University, Paris, France
| | - Angeline Gradolatto
- INSERM, AIM, Center of Research in Myology, UMRS974, Sorbonne University, Paris, France
| | - Frédérique Truffault
- INSERM, AIM, Center of Research in Myology, UMRS974, Sorbonne University, Paris, France
| | | | - Sonia Berrih-Aknin
- INSERM, AIM, Center of Research in Myology, UMRS974, Sorbonne University, Paris, France
| | - Rozen Le Panse
- INSERM, AIM, Center of Research in Myology, UMRS974, Sorbonne University, Paris, France
| | - Nadine Dragin
- INSERM, AIM, Center of Research in Myology, UMRS974, Sorbonne University, Paris, France.,Inovarion, Paris, France
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41
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Pohar J, Simon Q, Fillatreau S. Antigen-Specificity in the Thymic Development and Peripheral Activity of CD4 +FOXP3 + T Regulatory Cells. Front Immunol 2018; 9:1701. [PMID: 30083162 PMCID: PMC6064734 DOI: 10.3389/fimmu.2018.01701] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 07/10/2018] [Indexed: 01/12/2023] Open
Abstract
CD4+Foxp3+ T regulatory cells (Treg) are essential for the life of the organism, in particular because they protect the host against its own autoaggressive CD4+Foxp3- T lymphocytes (Tconv). Treg distinctively suppress autoaggressive immunity while permitting efficient defense against infectious diseases. This split effect indicates that Treg activity is controlled in an antigen-specific manner. This specificity is achieved first by the formation of the Treg repertoire during their development, and second by their activation in the periphery. This review presents novel information on the antigen-specificity of Treg development in the thymus, and Treg function in the periphery. These aspects have so far remained imprecisely understood due to the lack of knowledge of the actual antigens recognized by Treg during the different steps of their life, so that most previous studies have been performed using artificial antigens. However, recent studies identified some antigens mediating the positive selection of autoreactive Treg in the thymus, and the function of Treg in the periphery in autoimmune and allergic disorders. These investigations emphasized the remarkable specificity of Treg development and function. Indeed, the development of autoreactive Treg in the thymus was found to be mediated by single autoantigens, so that the absence of one antigen led to a dramatic loss of Treg reacting toward that antigen. The specificity of Treg development is important because the constitution of the Treg repertoire, and especially the presence of holes in this repertoire, was found to crucially influence human immunopathology. Indeed, it was found that the development of human immunopathology was permitted by the lack of Treg against the antigens driving the autoimmune or allergic T cell responses rather than by the impairment of Treg activation or function. The specificity of Treg suppression in the periphery is therefore intimately associated with the mechanisms shaping the formation of the Treg repertoire during their development. This novel information refines significantly our understanding of the antigen-specificity of Treg protective function, which is required to envision how these cells distinctively regulate unwanted immune responses as well as for the development of appropriate approaches to optimally harness them therapeutically in autoimmune, malignant, and infectious diseases.
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Affiliation(s)
- Jelka Pohar
- Institut Necker-Enfants Malades, INSERM U1151-CNRS UMR 8253, Paris, France
| | - Quentin Simon
- Institut Necker-Enfants Malades, INSERM U1151-CNRS UMR 8253, Paris, France
| | - Simon Fillatreau
- Institut Necker-Enfants Malades, INSERM U1151-CNRS UMR 8253, Paris, France.,Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris, France.,AP-HP, Hôpital Necker Enfants Malades, Paris, France
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42
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Betts CB, Pennock ND, Caruso BP, Ruffell B, Borges VF, Schedin P. Mucosal Immunity in the Female Murine Mammary Gland. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2018; 201:734-746. [PMID: 29884705 PMCID: PMC6036228 DOI: 10.4049/jimmunol.1800023] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 05/11/2018] [Indexed: 12/12/2022]
Abstract
The mammary gland is not classically considered a mucosal organ, although it exhibits some features common to mucosal tissues. Notably, the mammary epithelium is contiguous with the external environment, is exposed to bacteria during lactation, and displays antimicrobial features. Nonetheless, immunological hallmarks predictive of mucosal function have not been demonstrated in the mammary gland, including immune tolerance to foreign Ags under homeostasis. This inquiry is important, as mucosal immunity in the mammary gland may assure infant and women's health during lactation. Further, such mucosal immune programs may protect mammary function at the expense of breast cancer promotion via decreased immune surveillance. In this study, using murine models, we evaluated mammary specific mucosal attributes focusing on two reproductive states at increased risk for foreign and self-antigen exposure: lactation and weaning-induced involution. We find a baseline mucosal program of RORγT+ CD4+ T cells that is elevated within lactating and involuting mammary glands and is extended during involution to include tolerogenic dendritic cell phenotypes, barrier-supportive antimicrobials, and immunosuppressive Foxp3+ CD4+ T cells. Further, we demonstrate suppression of Ag-dependent CD4+ T cell activation, data consistent with immune tolerance. We also find Ag-independent accumulation of memory RORγT+ Foxp3+ CD4+ T cells specifically within the involution mammary gland consistent with an active immune process. Overall, these data elucidate strong mucosal immune programs within lactating and involuting mammary glands. Our findings support the classification of the mammary gland as a temporal mucosal organ and open new avenues for exploration into breast pathologic conditions, including compromised lactation and breast cancer.
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MESH Headings
- Animals
- Antigen Presentation
- Cells, Cultured
- Female
- Forkhead Transcription Factors/metabolism
- Humans
- Immune Tolerance
- Immunity, Mucosal
- Lactation
- Mammary Glands, Animal/physiology
- Mammary Glands, Human/physiology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Nuclear Receptor Subfamily 1, Group F, Member 3/genetics
- Nuclear Receptor Subfamily 1, Group F, Member 3/metabolism
- T-Lymphocytes, Regulatory/immunology
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Affiliation(s)
- Courtney B Betts
- Department of Cell, Developmental and Cancer Biology, Oregon Health and Science University, Portland, OR 97239
| | - Nathan D Pennock
- Department of Cell, Developmental and Cancer Biology, Oregon Health and Science University, Portland, OR 97239
| | - Breanna P Caruso
- Department of Cell, Developmental and Cancer Biology, Oregon Health and Science University, Portland, OR 97239
| | - Brian Ruffell
- Department of Immunology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612
- Department of Breast Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL
| | - Virginia F Borges
- Division of Medical Oncology, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
- University of Colorado Cancer Center, Aurora, CO 80045
- Young Women's Breast Cancer Translational Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045; and
| | - Pepper Schedin
- Department of Cell, Developmental and Cancer Biology, Oregon Health and Science University, Portland, OR 97239;
- University of Colorado Cancer Center, Aurora, CO 80045
- Knight Cancer Institute, Oregon Health and Science University, Portland, OR 97239
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43
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Assis AF, Li J, Donate PB, Dernowsek JA, Manley NR, Passos GA. Predicted miRNA-mRNA-mediated posttranscriptional control associated with differences in cervical and thoracic thymus function. Mol Immunol 2018; 99:39-52. [DOI: 10.1016/j.molimm.2018.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 03/09/2018] [Accepted: 04/05/2018] [Indexed: 12/12/2022]
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44
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Lovewell TRJ, McDonagh AJG, Messenger AG, Azzouz M, Tazi-Ahnini R. Meta-Analysis of Autoimmune Regulator-Regulated Genes in Human and Murine Models: A Novel Human Model Provides Insights on the Role of Autoimmune Regulator in Regulating STAT1 and STAT1-Regulated Genes. Front Immunol 2018; 9:1380. [PMID: 30002654 PMCID: PMC6031710 DOI: 10.3389/fimmu.2018.01380] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 06/04/2018] [Indexed: 12/14/2022] Open
Abstract
Autoimmune regulator (AIRE) regulates promiscuous expression of tissue-restricted antigens in medullary epithelial cells (mTEC) of the thymus. To understand the diverse effects of AIRE, it is crucial to elucidate the molecular mechanisms underlying the process of AIRE-regulated gene expression. In this study, we generated a recombinant AIRE expression variant of the TEC 1A3 human cell line, TEC 1A3 AIREhi, to determine genes targeted by AIRE, and using microarray analysis, we identified 482 genes showing significant differential expression (P < 0.05; false discovery rate <5%), with 353 upregulated and 129 downregulated by AIRE expression. Microarray data were validated by quantitative PCR, confirming the differential expression of 12 known AIRE-regulated genes. Comparison of AIRE-dependent differential expression in our cell line model with murine datasets identified 447 conserved genes with a number of transcription regulatory interactions, forming several key nodes, including STAT1, which had over 30 interactions with other AIRE-regulated genes. As STAT1 mutations cause dominant chronic mucocutaneous candidiasis and decreased STAT1 levels in monocytes of autoimmune polyglandular syndrome 1 (APS-1) patients, it was important to further characterize AIRE–STAT1 interactions. TEC 1A3AIREhi were treated with the STAT1 phosphorylation inhibitors fludarabine and LLL3 showed that phosphorylated STAT1 (p-STAT1) was not responsible for any of the observed differential expression. Moreover, treatment of TEC 1A3 AIREhi with STAT1 shRNA did not induce any significant variation in the expression of unphosphorylated STAT1 (U-STAT1) downstream genes, suggesting that these genes were directly regulated by AIRE but not via U-STAT1. The novel model system we have developed provides potential opportunities for further analysis of the pathogenesis of (APS-1) and the wider roles of the AIRE gene.
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Affiliation(s)
- Thomas R J Lovewell
- Department of Infection, Immunity and Cardiovascular Disease, The Medical School, University of Sheffield, Sheffield, United Kingdom
| | - Andrew J G McDonagh
- Department of Dermatology, Royal Hallamshire Hospital, Sheffield, United Kingdom
| | - Andrew G Messenger
- Department of Dermatology, Royal Hallamshire Hospital, Sheffield, United Kingdom
| | - Mimoun Azzouz
- Department of Neuroscience, The Medical School, University of Sheffield, Sheffield, United Kingdom
| | - Rachid Tazi-Ahnini
- Department of Infection, Immunity and Cardiovascular Disease, The Medical School, University of Sheffield, Sheffield, United Kingdom
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45
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Montero-Herradón S, García-Ceca J, Zapata AG. Altered Maturation of Medullary TEC in EphB-Deficient Thymi Is Recovered by RANK Signaling Stimulation. Front Immunol 2018; 9:1020. [PMID: 29867988 PMCID: PMC5954084 DOI: 10.3389/fimmu.2018.01020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 04/24/2018] [Indexed: 12/31/2022] Open
Abstract
In the present study, the relevance of EphB2 and EphB3 tyrosine kinase receptors for the maturation of medullary thymic epithelial cells (TECs) is analyzed. The absence of both molecules, but particularly that of EphB2, courses with altered maturation of medullary Cld3,4hiSSEA1+ epithelial progenitor cells, mature medulla epithelial cells, defined by the expression of specific cell markers, including UEA1, MHCII, CD40, CD80, and AIRE, and reduced expansion of medullary islets. In vivo assays demonstrate that these changes are a consequence of the absence of EphBs in both TECs and thymocytes. On the other hand, the changes, that remains in the adult thymus, correlated well with reduced proportions of E15.5 Vγ5+RANKL+ cells in EphB-deficient thymi that could result in decreased stimulation of RANK+ medullary TECs to mature, a fact that was confirmed by recovering of proportions of both CD40hiCD80+ and MHCIIhiUEA1+ mature medullary TECs of mutant E14.5 alymphoid thymic lobes by agonist anti-RANK antibody treatment. Accordingly, the effects of EphB deficiency on medullary TECs maturation are recovered by RANK stimulation.
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Affiliation(s)
- Sara Montero-Herradón
- Department of Cell Biology, Faculty of Biology, Complutense University of Madrid, Madrid, Spain
| | - Javier García-Ceca
- Department of Cell Biology, Faculty of Biology, Complutense University of Madrid, Madrid, Spain
| | - Agustín G Zapata
- Department of Cell Biology, Faculty of Biology, Complutense University of Madrid, Madrid, Spain
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46
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Conteduca G, Indiveri F, Filaci G, Negrini S. Beyond APECED: An update on the role of the autoimmune regulator gene (AIRE) in physiology and disease. Autoimmun Rev 2018; 17:325-330. [PMID: 29427825 DOI: 10.1016/j.autrev.2017.10.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 10/24/2017] [Indexed: 12/15/2022]
Abstract
The autoimmune regulator gene (AIRE) is a transcription factor expressed both in the thymus, by medullary thymic epithelial cells, and in secondary lymphoid organs. AIRE controls the local transcription of organ- specific proteins typically expressed in peripheral tissues, thus allowing the negative selection of self- reactive T cells. The crucial role played by AIRE in central immune tolerance emerged in the studies on the pathogenesis of Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy, a rare inherited polyendocrine/autoimmune disease. Thereafter, several studies found evidences indicating that AIRE impairment might be pathogenically involved in several autoimmune diseases and in tumorigenesis. In this review, we focus on recent advances relative to AIRE's effect on T cell development in physiology and disease. In particular, we address the following issues: 1) AIRE function and mTECs biology, 2) the impact of AIRE gene mutations in autoimmune diseases, and 3) the role of AIRE gene in anti-tumor immune response.
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Affiliation(s)
- Giuseppina Conteduca
- Groupe Interdisciplinaire de Génoprotéomique Appliquée (GIGA)-I3, Laboratory of Hematology, University of Liège, Liège, Belgium
| | - Francesco Indiveri
- Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy; Department of Internal Medicine, Clinical Immunology Unit, University of Genoa, Genoa, Italy
| | - Gilberto Filaci
- Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy; Department of Internal Medicine, Clinical Immunology Unit, University of Genoa, Genoa, Italy.
| | - Simone Negrini
- Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy; Department of Internal Medicine, Clinical Immunology Unit, University of Genoa, Genoa, Italy
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47
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Extracellular vesicle-mediated MHC cross-dressing in immune homeostasis, transplantation, infectious diseases, and cancer. Semin Immunopathol 2018; 40:477-490. [PMID: 29594331 DOI: 10.1007/s00281-018-0679-8] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 03/16/2018] [Indexed: 12/19/2022]
Abstract
Eukaryotic cells employ different types of extracellular vesicles (EVs) to exchange proteins, mRNAs, non-coding regulatory RNAs, carbohydrates, and lipids. Cells of the immune system, in particular antigen (Ag)-presenting cells (APCs), acquire major histocompatibility complex (MHC) class I and II molecules loaded with antigenic peptides from leukocytes and tissue parenchymal and stromal cells, through a mechanism known as MHC cross-dressing. Increasing evidence indicates that cross-dressing of APCs with pre-formed Ag-peptide/MHC complexes (pMHCs) is mediated via passage of clusters of EVs with characteristics of exosomes. A percentage of the transferred EVs remain attached to the acceptor APCs, with the appropriate orientation, at sufficient concentration within localized areas of the plasma membrane, and for sufficient time, so the preformed pMHCs carried by the EVs are presented without further processing, to cognate T cells. Although its biological relevance is not fully understood, numerous studies have demonstrated that MHC cross-dressing of APCs represents a pathway of Ag presentation of acquired pre-formed pMHCs to T cells-alternative to direct and cross-presentation-participate in immune homeostasis and T cell tolerance, cross-regulate alloreactive T cells with different MHC restricted specificities, and is a mechanism of Ag spreading for autologous, allogeneic, microbial, tumor, or vaccine-delivered Ags. Here, we compare MHC cross-dressing with other mechanisms and terminologies used for pMHC transfer, including trogocytosis. We discuss the experimental evidence, mostly from in vitro and ex vivo studies, of the role of MHC cross-dressing of APCs via EVs in positive or negative regulation of T cell immunity in the steady state, transplantation, microbial diseases, and cancer.
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48
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Abstract
About two decades ago, cloning of the autoimmune regulator (AIRE) gene materialized one of the most important actors on the scene of self-tolerance. Thymic transcription of genes encoding tissue-specific antigens (ts-ags) is activated by AIRE protein and embodies the essence of thymic self-representation. Pathogenic AIRE variants cause the autoimmune polyglandular syndrome type 1, which is a rare and complex disease that is gaining attention in research on autoimmunity. The animal models of disease, although not identically reproducing the human picture, supply fundamental information on mechanisms and extent of AIRE action: thanks to its multidomain structure, AIRE localizes to chromatin enclosing the target genes, binds to histones, and offers an anchorage to multimolecular complexes involved in initiation and post-initiation events of gene transcription. In addition, AIRE enhances mRNA diversity by favoring alternative mRNA splicing. Once synthesized, ts-ags are presented to, and cause deletion of the self-reactive thymocyte clones. However, AIRE function is not restricted to the activation of gene transcription. AIRE would control presentation and transfer of self-antigens for thymic cellular interplay: such mechanism is aimed at increasing the likelihood of engagement of the thymocytes that carry the corresponding T-cell receptors. Another fundamental role of AIRE in promoting self-tolerance is related to the development of thymocyte anergy, as thymic self-representation shapes at the same time the repertoire of regulatory T cells. Finally, AIRE seems to replicate its action in the secondary lymphoid organs, albeit the cell lineage detaining such property has not been fully characterized. Delineation of AIRE functions adds interesting data to the knowledge of the mechanisms of self-tolerance and introduces exciting perspectives of therapeutic interventions against the related diseases.
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Affiliation(s)
- Roberto Perniola
- Department of Pediatrics, Neonatal Intensive Care, Vito Fazzi Regional Hospital, Lecce, Italy
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49
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Koh AS, Miller EL, Buenrostro JD, Moskowitz DM, Wang J, Greenleaf WJ, Chang HY, Crabtree GR. Rapid chromatin repression by Aire provides precise control of immune tolerance. Nat Immunol 2018; 19:162-172. [PMID: 29335648 PMCID: PMC6049828 DOI: 10.1038/s41590-017-0032-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 12/07/2017] [Indexed: 01/23/2023]
Abstract
Aire mediates the expression of tissue-specific antigens in thymic epithelial cells to promote tolerance against self-reactive T lymphocytes. However, the mechanism that allows expression of tissue-specific genes at levels that prevent harm is unknown. Here we show that Brg1 generates accessibility at tissue-specific loci to impose central tolerance. We found that Aire has an intrinsic repressive function that restricts chromatin accessibility and opposes Brg1 across the genome. Aire exerted this repressive influence within minutes after recruitment to chromatin and restrained the amplitude of active transcription. Disease-causing mutations that impair Aire-induced activation also impair the protein's repressive function, which indicates dual roles for Aire. Together, Brg1 and Aire fine-tune the expression of tissue-specific genes at levels that prevent toxicity yet promote immune tolerance.
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Affiliation(s)
- Andrew S Koh
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA.
- Center for Personal Dynamic Regulomes, Stanford University School of Medicine, Stanford, CA, USA.
- Howard Hughes Medical Institute, Chevy Chase, MD, USA.
| | - Erik L Miller
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Jason D Buenrostro
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Harvard Society of Fellows, Harvard University, Cambridge, MA, USA
| | - David M Moskowitz
- Center for Personal Dynamic Regulomes, Stanford University School of Medicine, Stanford, CA, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Jing Wang
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - William J Greenleaf
- Center for Personal Dynamic Regulomes, Stanford University School of Medicine, Stanford, CA, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Department of Applied Physics, Stanford University, Stanford, CA, USA
- Chan Zuckerburg Biohub, San Francisco, CA, USA
| | - Howard Y Chang
- Center for Personal Dynamic Regulomes, Stanford University School of Medicine, Stanford, CA, USA
| | - Gerald R Crabtree
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA.
- Center for Personal Dynamic Regulomes, Stanford University School of Medicine, Stanford, CA, USA.
- Howard Hughes Medical Institute, Chevy Chase, MD, USA.
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50
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Miragaia RJ, Zhang X, Gomes T, Svensson V, Ilicic T, Henriksson J, Kar G, Lönnberg T. Single-cell RNA-sequencing resolves self-antigen expression during mTEC development. Sci Rep 2018; 8:685. [PMID: 29330484 PMCID: PMC5766627 DOI: 10.1038/s41598-017-19100-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 12/14/2017] [Indexed: 01/03/2023] Open
Abstract
The crucial capability of T cells for discrimination between self and non-self peptides is based on negative selection of developing thymocytes by medullary thymic epithelial cells (mTECs). The mTECs purge autoreactive T cells by expression of cell-type specific genes referred to as tissue-restricted antigens (TRAs). Although the autoimmune regulator (AIRE) protein is known to promote the expression of a subset of TRAs, its mechanism of action is still not fully understood. The expression of TRAs that are not under the control of AIRE also needs further characterization. Furthermore, expression patterns of TRA genes have been suggested to change over the course of mTEC development. Herein we have used single-cell RNA-sequencing to resolve patterns of TRA expression during mTEC development. Our data indicated that mTEC development consists of three distinct stages, correlating with previously described jTEC, mTEChi and mTEClo phenotypes. For each subpopulation, we have identified marker genes useful in future studies. Aire-induced TRAs were switched on during jTEC-mTEC transition and were expressed in genomic clusters, while otherwise the subsets expressed largely overlapping sets of TRAs. Moreover, population-level analysis of TRA expression frequencies suggested that such differences might not be necessary to achieve efficient thymocyte selection.
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Affiliation(s)
- Ricardo J Miragaia
- European Bioinformatics Institute (EMBL-EBI), European Molecular Biology Laboratory, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, United Kingdom
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, United Kingdom
- Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Xiuwei Zhang
- European Bioinformatics Institute (EMBL-EBI), European Molecular Biology Laboratory, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, United Kingdom
- University of California, Berkeley, USA
| | - Tomás Gomes
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, United Kingdom
| | - Valentine Svensson
- European Bioinformatics Institute (EMBL-EBI), European Molecular Biology Laboratory, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, United Kingdom
| | - Tomislav Ilicic
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, United Kingdom
| | - Johan Henriksson
- European Bioinformatics Institute (EMBL-EBI), European Molecular Biology Laboratory, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, United Kingdom
| | - Gozde Kar
- European Bioinformatics Institute (EMBL-EBI), European Molecular Biology Laboratory, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, United Kingdom
| | - Tapio Lönnberg
- European Bioinformatics Institute (EMBL-EBI), European Molecular Biology Laboratory, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, United Kingdom.
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, United Kingdom.
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, Finland.
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