1
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Kadouri N, Givony T, Nevo S, Hey J, Ben Dor S, Damari G, Dassa B, Dobes J, Weichenhan D, Bähr M, Paulsen M, Haffner-Krausz R, Mall MA, Plass C, Goldfarb Y, Abramson J. Transcriptional regulation of the thymus master regulator Foxn1. Sci Immunol 2022; 7:eabn8144. [PMID: 36026441 DOI: 10.1126/sciimmunol.abn8144] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
FOXN1 is a transcription factor critical for the development of both thymic epithelial cell (TEC) and hair follicle cell (HFC) compartments. However, mechanisms controlling its expression remain poorly understood. To address this question, we performed thorough analyses of the evolutionary conservation and chromatin status of the Foxn1 locus in different tissues and states and identified several putative cis-regulatory regions unique to TECs versus HFCs. Furthermore, experiments using genetically modified mice with specific deletions in the Foxn1 locus and additional bioinformatic analyses helped us identify key regions and transcription factors involved in either positive or negative regulation of Foxn1 in both TECs and HFCs. Specifically, we identified SIX1 and FOXN1 itself as key factors inducing Foxn1 expression in embryonic and neonatal TECs. Together, our data provide important mechanistic insights into the transcriptional regulation of the Foxn1 gene in TEC versus HFC and highlight the role of FOXN1 in its autoregulation.
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Affiliation(s)
- Noam Kadouri
- Department of Immunology and Regenerative Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Tal Givony
- Department of Immunology and Regenerative Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Shir Nevo
- Department of Immunology and Regenerative Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Joschka Hey
- Division of Cancer Epigenomics, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Ruprecht Karl University of Heidelberg, Heidelberg, Germany
| | - Shifra Ben Dor
- Bioinformatics Unit, Weizmann Institute of Science, Rehovot, Israel
| | - Golda Damari
- Department of Veterinary Resources, Weizmann Institute of Science, Rehovot, Israel
| | - Bareket Dassa
- Bioinformatics Unit, Weizmann Institute of Science, Rehovot, Israel
| | - Jan Dobes
- Department of Immunology and Regenerative Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Dieter Weichenhan
- Division of Cancer Epigenomics, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Marion Bähr
- Division of Cancer Epigenomics, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Michelle Paulsen
- Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), Heidelberg, Germany.,Department of Translational Pulmonology, University of Heidelberg, Heidelberg, Germany
| | | | - Marcus A Mall
- Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), Heidelberg, Germany.,Department of Translational Pulmonology, University of Heidelberg, Heidelberg, Germany.,Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Christoph Plass
- Division of Cancer Epigenomics, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Yael Goldfarb
- Department of Immunology and Regenerative Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Jakub Abramson
- Department of Immunology and Regenerative Biology, Weizmann Institute of Science, Rehovot, Israel
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2
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Carter JA, Strömich L, Peacey M, Chapin SR, Velten L, Steinmetz LM, Brors B, Pinto S, Meyer HV. Transcriptomic diversity in human medullary thymic epithelial cells. Nat Commun 2022; 13:4296. [PMID: 35918316 PMCID: PMC9345899 DOI: 10.1038/s41467-022-31750-1] [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: 10/25/2021] [Accepted: 06/30/2022] [Indexed: 12/03/2022] Open
Abstract
The induction of central T cell tolerance in the thymus depends on the presentation of peripheral self-epitopes by medullary thymic epithelial cells (mTECs). This promiscuous gene expression (pGE) drives mTEC transcriptomic diversity, with non-canonical transcript initiation, alternative splicing, and expression of endogenous retroelements (EREs) representing important but incompletely understood contributors. Here we map the expression of genome-wide transcripts in immature and mature human mTECs using high-throughput 5' cap and RNA sequencing. Both mTEC populations show high splicing entropy, potentially driven by the expression of peripheral splicing factors. During mTEC maturation, rates of global transcript mis-initiation increase and EREs enriched in long terminal repeat retrotransposons are up-regulated, the latter often found in proximity to differentially expressed genes. As a resource, we provide an interactive public interface for exploring mTEC transcriptomic diversity. Our findings therefore help construct a map of transcriptomic diversity in the healthy human thymus and may ultimately facilitate the identification of those epitopes which contribute to autoimmunity and immune recognition of tumor antigens.
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Affiliation(s)
- Jason A. Carter
- grid.225279.90000 0004 0387 3667Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY USA ,grid.36425.360000 0001 2216 9681Medical Scientist Training Program, Stony Brook University, Stony Brook, NY USA ,grid.34477.330000000122986657Department of Surgery, University of Washington, Seattle, WA USA
| | - Léonie Strömich
- grid.7497.d0000 0004 0492 0584German Cancer Research Center, Heidelberg, Germany ,grid.7445.20000 0001 2113 8111Present Address: Imperial College London, London, UK
| | - Matthew Peacey
- grid.225279.90000 0004 0387 3667School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY USA
| | - Sarah R. Chapin
- grid.225279.90000 0004 0387 3667Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY USA
| | - Lars Velten
- grid.473715.30000 0004 6475 7299Centre for Genomic Regulation, The Barcelona Institute of Science and Technology, Barcelona, Spain ,grid.5612.00000 0001 2172 2676Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Lars M. Steinmetz
- grid.4709.a0000 0004 0495 846XEuropean Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany ,grid.168010.e0000000419368956Department of Genetics, Stanford University School of Medicine, Stanford, CA USA ,grid.168010.e0000000419368956Stanford Genome Technology Center, Palo Alto, CA USA
| | - Benedikt Brors
- grid.7497.d0000 0004 0492 0584German Cancer Research Center, Heidelberg, Germany
| | - Sheena Pinto
- grid.7497.d0000 0004 0492 0584German Cancer Research Center, Heidelberg, Germany
| | - Hannah V. Meyer
- grid.225279.90000 0004 0387 3667Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY USA
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3
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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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4
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Padonou F, Gonzalez V, Provin N, Yayilkan S, Jmari N, Maslovskaja J, Kisand K, Peterson P, Irla M, Giraud M. Aire-dependent transcripts escape Raver2-induced splice-event inclusion in the thymic epithelium. EMBO Rep 2022; 23:e53576. [PMID: 35037357 PMCID: PMC8892270 DOI: 10.15252/embr.202153576] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 12/14/2021] [Accepted: 12/21/2021] [Indexed: 12/31/2022] Open
Abstract
Aire allows medullary thymic epithelial cells (mTECs) to express and present a large number of self-antigens for central tolerance. Although mTECs express a high diversity of self-antigen splice isoforms, the extent and regulation of alternative splicing events (ASEs) in their transcripts, notably in those induced by Aire, is unknown. In contrast to Aire-neutral genes, we find that transcripts of Aire-sensitive genes show only a low number of ASEs in mTECs, with about a quarter present in peripheral tissues excluded from the thymus. We identify Raver2, as a splicing-related factor overexpressed in mTECs and dependent on H3K36me3 marks, that promotes ASEs in transcripts of Aire-neutral genes, leaving Aire-sensitive ones unaffected. H3K36me3 profiling reveals its depletion at Aire-sensitive genes and supports a mechanism that is preceding Aire expression leading to transcripts of Aire-sensitive genes with low ASEs that escape Raver2-induced alternative splicing. The lack of ASEs in Aire-induced transcripts would result in an incomplete Aire-dependent negative selection of autoreactive T cells, thus highlighting the need of complementary tolerance mechanisms to prevent activation of these cells in the periphery.
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Affiliation(s)
- Francine Padonou
- Nantes UniversitéINSERMCenter for Research in Transplantation and Translational Immunology, UMR 1064NantesFrance,Institut CochinINSERMCNRSParis UniversitéParisFrance
| | | | - Nathan Provin
- Nantes UniversitéINSERMCenter for Research in Transplantation and Translational Immunology, UMR 1064NantesFrance
| | - Sümeyye Yayilkan
- Nantes UniversitéINSERMCenter for Research in Transplantation and Translational Immunology, UMR 1064NantesFrance
| | - Nada Jmari
- Institut CochinINSERMCNRSParis UniversitéParisFrance
| | | | - Kai Kisand
- Molecular Pathology Research GroupUniversity of TartuTartuEstonia
| | - Pärt Peterson
- Molecular Pathology Research GroupUniversity of TartuTartuEstonia
| | - Magali Irla
- Aix‐Marseille UniversitéCNRSINSERMCIML, Centre d'Immunologie de Marseille‐LuminyMarseilleFrance
| | - Matthieu Giraud
- Nantes UniversitéINSERMCenter for Research in Transplantation and Translational Immunology, UMR 1064NantesFrance,Institut CochinINSERMCNRSParis UniversitéParisFrance
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5
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Lopes N, Boucherit N, Santamaria JC, Provin N, Charaix J, Ferrier P, Giraud M, Irla M. Thymocytes trigger self-antigen-controlling pathways in immature medullary thymic epithelial stages. eLife 2022; 11:69982. [PMID: 35188458 PMCID: PMC8860447 DOI: 10.7554/elife.69982] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 01/14/2022] [Indexed: 12/20/2022] Open
Abstract
Interactions of developing T cells with Aire+ medullary thymic epithelial cells expressing high levels of MHCII molecules (mTEChi) are critical for the induction of central tolerance in the thymus. In turn, thymocytes regulate the cellularity of Aire+ mTEChi. However, it remains unknown whether thymocytes control the precursors of Aire+ mTEChi that are contained in mTEClo cells or other mTEClo subsets that have recently been delineated by single-cell transcriptomic analyses. Here, using three distinct transgenic mouse models, in which antigen presentation between mTECs and CD4+ thymocytes is perturbed, we show by high-throughput RNA-seq that self-reactive CD4+ thymocytes induce key transcriptional regulators in mTEClo and control the composition of mTEClo subsets, including Aire+ mTEChi precursors, post-Aire and tuft-like mTECs. Furthermore, these interactions upregulate the expression of tissue-restricted self-antigens, cytokines, chemokines, and adhesion molecules important for T-cell development. This gene activation program induced in mTEClo is combined with a global increase of the active H3K4me3 histone mark. Finally, we demonstrate that these self-reactive interactions between CD4+ thymocytes and mTECs critically prevent multiorgan autoimmunity. Our genome-wide study thus reveals that self-reactive CD4+ thymocytes control multiple unsuspected facets from immature stages of mTECs, which determines their heterogeneity.
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Affiliation(s)
- Noella Lopes
- Aix-Marseille University, CNRS, INSERM, Centre d'Immunologie de Marseille-Luminy, Marseille, France
| | - Nicolas Boucherit
- Aix-Marseille University, CNRS, INSERM, Centre d'Immunologie de Marseille-Luminy, Marseille, France
| | - Jérémy C Santamaria
- Aix-Marseille University, CNRS, INSERM, Centre d'Immunologie de Marseille-Luminy, Marseille, France
| | - Nathan Provin
- Nantes Université, INSERM, Center for Research in Transplantation and Translational Immunology, UMR 1064, Nantes, France
| | - Jonathan Charaix
- Aix-Marseille University, CNRS, INSERM, Centre d'Immunologie de Marseille-Luminy, Marseille, France
| | - Pierre Ferrier
- Aix-Marseille University, CNRS, INSERM, Centre d'Immunologie de Marseille-Luminy, Marseille, France
| | - Matthieu Giraud
- Nantes Université, INSERM, Center for Research in Transplantation and Translational Immunology, UMR 1064, Nantes, France
| | - Magali Irla
- Aix-Marseille University, CNRS, INSERM, Centre d'Immunologie de Marseille-Luminy, Marseille, France
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6
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Martinez-Ruíz GU, Morales-Sánchez A, Bhandoola A. Transcriptional and epigenetic regulation in thymic epithelial cells. Immunol Rev 2022; 305:43-58. [PMID: 34750841 PMCID: PMC8766885 DOI: 10.1111/imr.13034] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 10/22/2021] [Accepted: 10/26/2021] [Indexed: 01/03/2023]
Abstract
The thymus is required for the development of both adaptive and innate-like T cell subsets. There is keen interest in manipulating thymic function for therapeutic purposes in circumstances of autoimmunity, immunodeficiency, and for purposes of immunotherapy. Within the thymus, thymic epithelial cells play essential roles in directing T cell development. Several transcription factors are known to be essential for thymic epithelial cell development and function, and a few transcription factors have been studied in considerable detail. However, the role of many other transcription factors is less well understood. Further, it is likely that roles exist for other transcription factors not yet known to be important in thymic epithelial cells. Recent progress in understanding of thymic epithelial cell heterogeneity has provided some new insight into transcriptional requirements in subtypes of thymic epithelial cells. However, it is unknown whether progenitors of thymic epithelial cells exist in the adult thymus, and consequently, developmental relationships linking putative precursors with differentiated cell types are poorly understood. While we do not presently possess a clear understanding of stage-specific requirements for transcription factors in thymic epithelial cells, new single-cell transcriptomic and epigenomic technologies should enable rapid progress in this field. Here, we review our current knowledge of transcription factors involved in the development, maintenance, and function of thymic epithelial cells, and the mechanisms by which they act.
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Affiliation(s)
- Gustavo Ulises Martinez-Ruíz
- T Cell Biology and Development Unit, Laboratory of Genome Integrity, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
- Research Division, Faculty of Medicine, National Autonomous University of Mexico, Mexico City, Mexico
- Children’s Hospital of Mexico Federico Gomez, Mexico City, Mexico
| | - Abigail Morales-Sánchez
- T Cell Biology and Development Unit, Laboratory of Genome Integrity, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
- Children’s Hospital of Mexico Federico Gomez, Mexico City, Mexico
| | - Avinash Bhandoola
- T Cell Biology and Development Unit, Laboratory of Genome Integrity, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
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7
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Azoury ME, Samassa F, Buitinga M, Nigi L, Brusco N, Callebaut A, Giraud M, Irla M, Lalanne AI, Carré A, Afonso G, Zhou Z, Brandao B, Colli ML, Sebastiani G, Dotta F, Nakayama M, Eizirik DL, You S, Pinto S, Mamula MJ, Verdier Y, Vinh J, Buus S, Mathieu C, Overbergh L, Mallone R. CD8 + T Cells Variably Recognize Native Versus Citrullinated GRP78 Epitopes in Type 1 Diabetes. Diabetes 2021; 70:2879-2891. [PMID: 34561224 PMCID: PMC8660990 DOI: 10.2337/db21-0259] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Accepted: 09/17/2021] [Indexed: 11/13/2022]
Abstract
In type 1 diabetes, autoimmune β-cell destruction may be favored by neoantigens harboring posttranslational modifications (PTMs) such as citrullination. We studied the recognition of native and citrullinated glucose-regulated protein (GRP)78 peptides by CD8+ T cells. Citrullination modulated T-cell recognition and, to a lesser extent, HLA-A2 binding. GRP78-reactive CD8+ T cells circulated at similar frequencies in healthy donors and donors with type 1 diabetes and preferentially recognized either native or citrullinated versions, without cross-reactivity. Rather, the preference for native GRP78 epitopes was associated with CD8+ T cells cross-reactive with bacterial mimotopes. In the pancreas, a dominant GRP78 peptide was instead preferentially recognized when citrullinated. To further clarify these recognition patterns, we considered the possibility of citrullination in the thymus. Citrullinating peptidylarginine deiminase (Padi) enzymes were expressed in murine and human medullary epithelial cells (mTECs), with citrullinated proteins detected in murine mTECs. However, Padi2 and Padi4 expression was diminished in mature mTECs from NOD mice versus C57BL/6 mice. We conclude that, on one hand, the CD8+ T cell preference for native GRP78 peptides may be shaped by cross-reactivity with bacterial mimotopes. On the other hand, PTMs may not invariably favor loss of tolerance because thymic citrullination, although impaired in NOD mice, may drive deletion of citrulline-reactive T cells.
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Affiliation(s)
| | | | - Mijke Buitinga
- Laboratory of Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
| | - Laura Nigi
- Toscana Life Sciences, Diabetes Unit and Fondazione Umberto di Mario ONLUS, Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - Noemi Brusco
- Toscana Life Sciences, Diabetes Unit and Fondazione Umberto di Mario ONLUS, Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - Aïsha Callebaut
- Laboratory of Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
| | - Matthieu Giraud
- Centre de Recherche en Transplantation et Immunologie, INSERM UMR1064, Université de Nantes, Nantes, France
| | - Magali Irla
- Centre d'Immunologie de Marseille-Luminy, INSERM, CNRS, Aix-Marseille University, Marseille, France
| | - Ana Ines Lalanne
- Université de Paris, Institut Cochin, CNRS, INSERM, Paris, France
| | - Alexia Carré
- Université de Paris, Institut Cochin, CNRS, INSERM, Paris, France
| | - Georgia Afonso
- Université de Paris, Institut Cochin, CNRS, INSERM, Paris, France
| | - Zhicheng Zhou
- Université de Paris, Institut Cochin, CNRS, INSERM, Paris, France
| | - Barbara Brandao
- Université de Paris, Institut Cochin, CNRS, INSERM, Paris, France
| | - Maikel L Colli
- Medical Faculty, Center for Diabetes Research and Welbio, Université Libre de Bruxelles, Brussels, Belgium
| | - Guido Sebastiani
- Toscana Life Sciences, Diabetes Unit and Fondazione Umberto di Mario ONLUS, Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - Francesco Dotta
- Toscana Life Sciences, Diabetes Unit and Fondazione Umberto di Mario ONLUS, Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - Maki Nakayama
- Barbara Davis Center for Childhood Diabetes, University of Colorado School of Medicine, Aurora, CO
| | - Decio L Eizirik
- Medical Faculty, Center for Diabetes Research and Welbio, Université Libre de Bruxelles, Brussels, Belgium
- Indiana Biosciences Research Institute, Indianapolis, IN
| | - Sylvaine You
- Université de Paris, Institut Cochin, CNRS, INSERM, Paris, France
| | - Sheena Pinto
- Division of Developmental Immunology, Deutsches Krebsforschungszentrum, Heidelberg, Germany
| | | | - Yann Verdier
- ESPCI Paris, PSL University, Spectrométrie de Masse Biologique et Protéomique, CNRS UMR8249, Paris, France
| | - Joelle Vinh
- ESPCI Paris, PSL University, Spectrométrie de Masse Biologique et Protéomique, CNRS UMR8249, Paris, France
| | - Soren Buus
- Department of International Health, Immunology and Microbiology, Panum Institute, Copenhagen, Denmark
| | - Chantal Mathieu
- Laboratory of Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
| | - Lut Overbergh
- Laboratory of Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
| | - Roberto Mallone
- Université de Paris, Institut Cochin, CNRS, INSERM, Paris, France
- Assistance Publique Hôpitaux de Paris, Service de Diabétologie et Immunologie Clinique, Cochin Hospital, Paris, France
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8
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Hu C, Zhang K, Jiang F, Wang H, Shao Q. Epigenetic modifications in thymic epithelial cells: an evolutionary perspective for thymus atrophy. Clin Epigenetics 2021; 13:210. [PMID: 34819170 PMCID: PMC8612001 DOI: 10.1186/s13148-021-01197-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 11/08/2021] [Indexed: 02/06/2023] Open
Abstract
Background The thymic microenvironment is mainly comprised of thymic epithelial cells, the cytokines, exosomes, surface molecules, and hormones from the cells, and plays a vital role in the development, differentiation, maturation and homeostasis of T lymphocytes. However, the thymus begins to degenerate as early as the second year of life and continues through aging in human beings, leading to a decreased output of naïve T cells, the limited TCR diversity and an expansion of monoclonal memory T cells in the periphery organs. These alternations will reduce the adaptive immune response to tumors and emerging infectious diseases, such as COVID-19, also it is easier to suffer from autoimmune diseases in older people. In the context of global aging, it is important to investigate and clarify the causes and mechanisms of thymus involution. Main body Epigenetics include histone modification, DNA methylation, non-coding RNA effects, and chromatin remodeling. In this review, we discuss how senescent thymic epithelial cells determine and control age-related thymic atrophy, how this process is altered by epigenetic modification. How the thymus adipose influences the dysfunctions of the thymic epithelial cells, and the prospects of targeting thymic epithelial cells for the treatment of thymus atrophy. Conclusion Epigenetic modifications are emerging as key regulators in governing the development and senescence of thymic epithelial cells. It is beneficial to re-establish effective thymopoiesis, identify the potential therapeutic strategy and rejuvenate the immune function in the elderly.
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Affiliation(s)
- Cexun Hu
- Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, People's Republic of China.,Department of Immunology, Key Laboratory of Medical Science and Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, No. 301 Xuefu Road, Zhenjiang, 212013, Jiangsu, People's Republic of China
| | - Keyu Zhang
- Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, People's Republic of China.,Department of Immunology, Key Laboratory of Medical Science and Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, No. 301 Xuefu Road, Zhenjiang, 212013, Jiangsu, People's Republic of China
| | - Feng Jiang
- Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, People's Republic of China.,Department of Immunology, Key Laboratory of Medical Science and Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, No. 301 Xuefu Road, Zhenjiang, 212013, Jiangsu, People's Republic of China
| | - Hui Wang
- Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, People's Republic of China. .,Department of Immunology, Key Laboratory of Medical Science and Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, No. 301 Xuefu Road, Zhenjiang, 212013, Jiangsu, People's Republic of China.
| | - Qixiang Shao
- Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, People's Republic of China. .,Department of Immunology, Key Laboratory of Medical Science and Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, No. 301 Xuefu Road, Zhenjiang, 212013, Jiangsu, People's Republic of China. .,Jiangsu College of Nursing, School of Medical Science and Laboratory Medicine, Huai'an, 223002, Jiangsu, People's Republic of China.
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9
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Jansen K, Shikama-Dorn N, Attar M, Maio S, Lopopolo M, Buck D, Holländer GA, Sansom SN. RBFOX splicing factors contribute to a broad but selective recapitulation of peripheral tissue splicing patterns in the thymus. Genome Res 2021; 31:2022-2034. [PMID: 34649931 PMCID: PMC8559713 DOI: 10.1101/gr.275245.121] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 08/17/2021] [Indexed: 12/13/2022]
Abstract
Thymic epithelial cells (TEC) control the selection of a T cell repertoire reactive to pathogens but tolerant of self. This process is known to involve the promiscuous expression of virtually the entire protein-coding gene repertoire, but the extent to which TEC recapitulate peripheral isoforms, and the mechanisms by which they do so, remain largely unknown. We performed the first assembly-based transcriptomic census of transcript structures and splicing factor (SF) expression in mouse medullary TEC (mTEC) and 21 peripheral tissues. Mature mTEC expressed 60.1% of all protein-coding transcripts, more than was detected in any of the peripheral tissues. However, for genes with tissue-restricted expression, mTEC produced fewer isoforms than did the relevant peripheral tissues. Analysis of exon inclusion revealed an absence of brain-specific microexons in mTEC. We did not find unusual numbers of novel transcripts in TEC, and we show that Aire, the facilitator of promiscuous gene expression, promotes the generation of long “classical” transcripts (with 5′ and 3′ UTRs) but has only a limited impact on alternative splicing in mTEC. Comprehensive assessment of SF expression in mTEC identified a small set of nonpromiscuously expressed SF genes, among which we confirmed RBFOX to be present with AIRE in mTEC nuclei. Using a conditional loss-of-function approach, we show that Rbfox2 promotes mTEC development and regulates the alternative splicing of promiscuously expressed genes. These data indicate that TEC recommission a small number of peripheral SFs, including members of the RBFOX family, to generate a broad but selective representation of the peripheral splice isoform repertoire.
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Affiliation(s)
- Kathrin Jansen
- The Kennedy Institute of Rheumatology, University of Oxford, Oxford OX3 7FY, United Kingdom.,Department of Paediatrics and the Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, United Kingdom
| | - Noriko Shikama-Dorn
- The University Children's Hospital of Basel and the Department of Biomedicine, University of Basel, 4056 Basel, Switzerland
| | - Moustafa Attar
- The Kennedy Institute of Rheumatology, University of Oxford, Oxford OX3 7FY, United Kingdom.,Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, United Kingdom
| | - Stefano Maio
- Department of Paediatrics and the Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, United Kingdom
| | - Maria Lopopolo
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, United Kingdom
| | - David Buck
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, United Kingdom
| | - Georg A Holländer
- Department of Paediatrics and the Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, United Kingdom.,The University Children's Hospital of Basel and the Department of Biomedicine, University of Basel, 4056 Basel, Switzerland.,Department of Biosystems Science and Engineering, ETH Zurich, 4058 Basel, Switzerland
| | - Stephen N Sansom
- The Kennedy Institute of Rheumatology, University of Oxford, Oxford OX3 7FY, United Kingdom
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10
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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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Abstract
The conventional perception asserts that immunology is the science of ‘discrimination’ between self and non-self. This concept is however no longer tenable as effector cells of the adaptive immune system are first conditioned to be tolerant to the body’s own antigens, collectively known as self until now. Only then attain these effectors the responsiveness to non-self. The acquisition of this essential state of tolerance to self occurs for T cells in the thymus, the last major organ of our body that revealed its intricate function in health and disease. The ‘thymus’ as an anatomical notion was first notably documented in Ancient Greece although our present understanding of the organ’s functions was only deciphered commencing in the 1960s. In the late 1980s, the thymus was identified as the site where clones of cells reactive to self, termed ‘forbidden’ thymocytes, are physically depleted as the result of a process now known as negative selection. The recognition of this mechanism further contributed to the belief that the central rationale of immunology as a science lies in the distinction between self and non-self. This review will discuss the evidence that the thymus serves as a unique lymphoid organ able to instruct T cells to recognize and be tolerant to harmless self before adopting the capacity to defend the body against potentially injurious non-self-antigens presented in the context of different challenges from infections to exposure to malignant cells. The emerging insight into the thymus’ cardinal functions now also provides an opportunity to exploit this knowledge to develop novel strategies that specifically prevent or even treat organ-specific autoimmune diseases.
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12
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The contribution of thymic tolerance to central nervous system autoimmunity. Semin Immunopathol 2020; 43:135-157. [PMID: 33108502 PMCID: PMC7925481 DOI: 10.1007/s00281-020-00822-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 10/09/2020] [Indexed: 12/15/2022]
Abstract
Autoimmune diseases of the central nervous system (CNS) are associated with high levels of morbidity and economic cost. Research efforts have previously focused on the contribution of the peripheral adaptive and innate immune systems to CNS autoimmunity. However, a failure of thymic negative selection is a necessary step in CNS-reactive T cells escaping into the periphery. Even with defective thymic or peripheral tolerance, the development of CNS inflammation is rare. The reasons underlying this are currently poorly understood. In this review, we examine evidence implicating thymic selection in the pathogenesis of CNS autoimmunity. Animal models suggest that thymic negative selection is an important factor in determining susceptibility to and severity of CNS inflammation. There are indirect clinical data that suggest thymic function is also important in human CNS autoimmune diseases. Specifically, the association between thymoma and paraneoplastic encephalitis and changes in T cell receptor excision circles in multiple sclerosis implicate thymic tolerance in these diseases. We identify potential associations between CNS autoimmunity susceptibility factors and thymic tolerance. The therapeutic manipulation of thymopoiesis has the potential to open up new treatment modalities, but a better understanding of thymic tolerance in CNS autoimmunity is required before this can be realised.
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13
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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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