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Poli MC. Proteasome disorders and inborn errors of immunity. Immunol Rev 2024; 322:283-299. [PMID: 38071420 DOI: 10.1111/imr.13299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 11/27/2023] [Accepted: 11/30/2023] [Indexed: 03/20/2024]
Abstract
Inborn errors of immunity (IEI) or primary immune deficiencies (PIDD) are caused by variants in genes encoding for molecules that are relevant to the innate or adaptive immune response. To date, defects in more than 450 different genes have been identified as causes of IEI, causing a constellation of heterogeneous clinical manifestations ranging from increased susceptibility to infection, to autoimmunity or autoinflammation. IEI that are mainly characterized by autoinflammation are broadly classified according to the inflammatory pathway that they predominantly perturb. Among autoinflammatory IEI are those characterized by the transcriptional upregulation of type I interferon genes and are referred to as interferonopathies. Within the spectrum of interferonopathies, genetic defects that affect the proteasome have been described to cause autoinflammatory disease and represent a growing area of investigation. This review is focused on describing the clinical, genetic, and molecular aspects of IEI associated with mutations that affect the proteasome and how the study of these diseases has contributed to delineate therapeutic interventions.
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Affiliation(s)
- M Cecilia Poli
- Faculty of Medicine, Clínica Alemana Universidad del Desarrollo, Santiago, Chile
- Unit of Immunology and Rheumatology Hospital Roberto del Río, Santiago, Chile
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2
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Tundo GR, Sbardella D, Oddone F, Kudriaeva AA, Lacal PM, Belogurov AA, Graziani G, Marini S. At the Cutting Edge against Cancer: A Perspective on Immunoproteasome and Immune Checkpoints Modulation as a Potential Therapeutic Intervention. Cancers (Basel) 2021; 13:4852. [PMID: 34638337 PMCID: PMC8507813 DOI: 10.3390/cancers13194852] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 09/20/2021] [Accepted: 09/21/2021] [Indexed: 01/22/2023] Open
Abstract
Immunoproteasome is a noncanonical form of proteasome with enzymological properties optimized for the generation of antigenic peptides presented in complex with class I MHC molecules. This enzymatic property makes the modulation of its activity a promising area of research. Nevertheless, immunotherapy has emerged as a front-line treatment of advanced/metastatic tumors providing outstanding improvement of life expectancy, even though not all patients achieve a long-lasting clinical benefit. To enhance the efficacy of the currently available immunotherapies and enable the development of new strategies, a broader knowledge of the dynamics of antigen repertoire processing by cancer cells is needed. Therefore, a better understanding of the role of immunoproteasome in antigen processing and of the therapeutic implication of its modulation is mandatory. Studies on the potential crosstalk between proteasome modulators and immune checkpoint inhibitors could provide novel perspectives and an unexplored treatment option for a variety of cancers.
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Affiliation(s)
| | | | | | - Anna A. Kudriaeva
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Miklukho-Maklaya 16/10, 117997 Moscow, Russia; (A.A.K.)
| | - Pedro M. Lacal
- Laboratory of Molecular Oncology, IDI-IRCCS, 00167 Rome, Italy;
| | - Alexey A. Belogurov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Miklukho-Maklaya 16/10, 117997 Moscow, Russia; (A.A.K.)
- Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow, Russia
| | - Grazia Graziani
- Laboratory of Molecular Oncology, IDI-IRCCS, 00167 Rome, Italy;
- Department of Systems Medicine, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Stefano Marini
- Department of Clinical Sciences and Translational Medicine, University of Rome Tor Vergata, 00133 Rome, Italy;
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3
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Apavaloaei A, Laverdure JP, Perreault C. PSMB11 regulates gene expression in cortical thymic epithelial cells. Cell Rep 2021; 36:109546. [PMID: 34496243 DOI: 10.1016/j.celrep.2021.109546] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 11/30/2020] [Accepted: 07/26/2021] [Indexed: 12/13/2022] Open
Abstract
The PSMB11 proteasomal subunit, expressed only in cortical thymic epithelial cells (cTECs), is essential for the development of functional CD8+ T cells. An attractive yet unproven theory holds that PSMB11 generates unique major histocompatibility complex class I (MHC I)-associated peptides required for positive selection. We recently reported that PSMB11 regulates the expression of hundreds of genes in cTECs, mainly by differential proteolysis of transcription factors. Thereby, PSMB11 maintains the distinctness of cTECs relative to medullary TECs (mTECs) and promotes cortex-to-medulla migration of developing thymocytes. These conclusions have been challenged by Ohigashi and colleagues, who suggest that their data show that PSMB11 uniquely controls antigen presentation without affecting cTEC biology. Here, we perform a comprehensive reanalysis of transcriptomic and proteomic data from the Ohigashi lab and confirm our original conclusions. This Matters Arising paper is in response to Ohigashi et al. (2019), published in Cell Reports. See also the response by Ohigashi and Takahama (2021), published in this issue of Cell Reports.
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Affiliation(s)
- Anca Apavaloaei
- Institute for Research in Immunology and Cancer, Montreal, QC H3C 3J7, Canada; Department of Medicine, University of Montreal, Montreal, QC H3C 3J7, Canada
| | | | - Claude Perreault
- Institute for Research in Immunology and Cancer, Montreal, QC H3C 3J7, Canada; Department of Medicine, University of Montreal, Montreal, QC H3C 3J7, Canada.
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4
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Joyce S, Ternette N. Know thy immune self and non-self: Proteomics informs on the expanse of self and non-self, and how and where they arise. Proteomics 2021; 21:e2000143. [PMID: 34310018 PMCID: PMC8865197 DOI: 10.1002/pmic.202000143] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 06/30/2021] [Accepted: 07/19/2021] [Indexed: 12/30/2022]
Abstract
T cells play an important role in the adaptive immune response to a variety of infections and cancers. Initiation of a T cell mediated immune response requires antigen recognition in a process termed MHC (major histocompatibility complex) restri ction. A T cell antigen is a composite structure made up of a peptide fragment bound within the antigen‐binding groove of an MHC‐encoded class I or class II molecule. Insight into the precise composition and biology of self and non‐self immunopeptidomes is essential to harness T cell mediated immunity to prevent, treat, or cure infectious diseases and cancers. T cell antigen discovery is an arduous task! The pioneering work in the early 1990s has made large‐scale T cell antigen discovery possible. Thus, advancements in mass spectrometry coupled with proteomics and genomics technologies make possible T cell antigen discovery with ease, accuracy, and sensitivity. Yet we have only begun to understand the breadth and the depth of self and non‐self immunopeptidomes because the molecular biology of the cell continues to surprise us with new secrets directly related to the source, and the processing and presentation of MHC ligands. Focused on MHC class I molecules, this review, therefore, provides a brief historic account of T cell antigen discovery and, against a backdrop of key advances in molecular cell biologic processes, elaborates on how proteogenomics approaches have revolutionised the field.
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Affiliation(s)
- Sebastian Joyce
- Department of Veterans Affairs, Tennessee Valley Healthcare System and the Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Nicola Ternette
- Centre for Cellular and Molecular Physiology, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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5
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Role of Proteasomes in Inflammation. J Clin Med 2021; 10:jcm10081783. [PMID: 33923887 PMCID: PMC8072576 DOI: 10.3390/jcm10081783] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 04/10/2021] [Accepted: 04/14/2021] [Indexed: 12/14/2022] Open
Abstract
The ubiquitin–proteasome system (UPS) is involved in multiple cellular functions including the regulation of protein homeostasis, major histocompatibility (MHC) class I antigen processing, cell cycle proliferation and signaling. In humans, proteasome loss-of-function mutations result in autoinflammation dominated by a prominent type I interferon (IFN) gene signature. These genomic alterations typically cause the development of proteasome-associated autoinflammatory syndromes (PRAAS) by impairing proteasome activity and perturbing protein homeostasis. However, an abnormal increased proteasomal activity can also be found in other human inflammatory diseases. In this review, we cast a light on the different clinical aspects of proteasomal activity in human disease and summarize the currently studied therapeutic approaches.
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6
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Frantzeskakis M, Takahama Y, Ohigashi I. The Role of Proteasomes in the Thymus. Front Immunol 2021; 12:646209. [PMID: 33815406 PMCID: PMC8017227 DOI: 10.3389/fimmu.2021.646209] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Accepted: 03/05/2021] [Indexed: 12/26/2022] Open
Abstract
The thymus provides a microenvironment that supports the generation and selection of T cells. Cortical thymic epithelial cells (cTECs) and medullary thymic epithelial cells (mTECs) are essential components of the thymic microenvironment and present MHC-associated self-antigens to developing thymocytes for the generation of immunocompetent and self-tolerant T cells. Proteasomes are multicomponent protease complexes that degrade ubiquitinated proteins and produce peptides that are destined to be associated with MHC class I molecules. cTECs specifically express thymoproteasomes that are essential for optimal positive selection of CD8+ T cells, whereas mTECs, which contribute to the establishment of self-tolerance in T cells, express immunoproteasomes. Immunoproteasomes are also detectable in dendritic cells and developing thymocytes, additionally contributing to T cell development in the thymus. In this review, we summarize the functions of proteasomes expressed in the thymus, focusing on recent findings pertaining to the functions of the thymoproteasomes and the immunoproteasomes.
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Affiliation(s)
- Melina Frantzeskakis
- Thymus Biology Section, Experimental Immunology Branch, National Cancer Institute, Bethesda, MD, United States
| | - Yousuke Takahama
- Thymus Biology Section, Experimental Immunology Branch, National Cancer Institute, Bethesda, MD, United States
| | - Izumi Ohigashi
- Division of Experimental Immunology, Institute of Advanced Medical Sciences, University of Tokushima, Tokushima, Japan
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7
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Kasahara M. Role of immunoproteasomes and thymoproteasomes in health and disease. Pathol Int 2021; 71:371-382. [PMID: 33657242 DOI: 10.1111/pin.13088] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 02/11/2021] [Indexed: 12/14/2022]
Abstract
The proteasome is a multisubunit protease that degrades intracellular proteins into small peptides. Besides playing a pivotal role in many cellular processes indispensable for survival, it is involved in the production of peptides presented by major histocompatibility complex class I molecules. In addition to the standard proteasome shared in all eukaryotes, jawed vertebrates have two specialized forms of proteasome known as immunoproteasomes and thymoproteasomes. The immunoproteasome, which contains cytokine-inducible catalytic subunits with distinct cleavage specificities, produces peptides presented by class I molecules more efficiently than the standard proteasome. The thymoproteasome, which contains a unique catalytic subunit β5t, is a tissue-specific proteasome expressed exclusively in cortical thymic epithelial cells. It plays a critical role in CD8+ cytotoxic T cell development via positive selection. This review provides a brief overview on the structure and function of these specialized forms of proteasome and their involvement in human disease.
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Affiliation(s)
- Masanori Kasahara
- Department of Pathology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Hokkaido, Japan
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8
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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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9
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Fibroblasts as a source of self-antigens for central immune tolerance. Nat Immunol 2020; 21:1172-1180. [PMID: 32839611 DOI: 10.1038/s41590-020-0756-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 07/02/2020] [Indexed: 12/13/2022]
Abstract
Fibroblasts are one of the most common but also neglected types of stromal cells, the heterogeneity of which underlies the specific function of tissue microenvironments in development and regeneration. In the thymus, autoreactive T cells are thought to be negatively selected by reference to the self-antigens expressed in medullary epithelial cells, but the contribution of other stromal cells to tolerance induction has been poorly examined. In the present study, we report a PDGFR+ gp38+ DPP4- thymic fibroblast subset that is required for T cell tolerance induction. The deletion of the lymphotoxin β-receptor in thymic fibroblasts caused an autoimmune phenotype with decreased expression of tissue-restricted and fibroblast-specific antigens, offering insight into the long-sought target of lymphotoxin signaling in the context of the regulation of autoimmunity. Thus, thymic medullary fibroblasts play an essential role in the establishment of central tolerance by producing a diverse array of self-antigens.
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10
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Kondo K, Ohigashi I, Takahama Y. Thymus machinery for T-cell selection. Int Immunol 2020; 31:119-125. [PMID: 30476234 DOI: 10.1093/intimm/dxy081] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 11/20/2018] [Indexed: 01/01/2023] Open
Abstract
An immunocompetent and self-tolerant pool of naive T cells is formed in the thymus through the process of repertoire selection. T cells that are potentially capable of responding to foreign antigens are positively selected in the thymic cortex and are further selected in the thymic medulla to help prevent self-reactivity. The affinity between T-cell antigen receptors expressed by newly generated T cells and self-peptide-major histocompatibility complexes displayed in the thymic microenvironments plays a key role in determining the fate of developing T cells during thymic selection. Recent advances in our knowledge of the biology of thymic epithelial cells have revealed unique machinery that contributes to positive and negative selection in the thymus. In this article, we summarize recent findings on thymic T-cell selection, focusing on the machinery unique to thymic epithelial cells.
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Affiliation(s)
- Kenta Kondo
- Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.,Division of Experimental Immunology, Institute of Advanced Medical Sciences, University of Tokushima, Kuramoto, Tokushima, Japan
| | - Izumi Ohigashi
- Division of Experimental Immunology, Institute of Advanced Medical Sciences, University of Tokushima, Kuramoto, Tokushima, Japan
| | - Yousuke Takahama
- Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.,Division of Experimental Immunology, Institute of Advanced Medical Sciences, University of Tokushima, Kuramoto, Tokushima, Japan
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11
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Retroviral Gene Transduction into T Cell Progenitors for Analysis of T Cell Development in the Thymus. Methods Mol Biol 2020; 2111:193-203. [PMID: 31933209 DOI: 10.1007/978-1-0716-0266-9_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The thymus is an organ where T cells develop throughout life. Using mice as a model animal, molecular mechanisms of intrathymic T cell development have been studied. Fetal thymus organ culture technique enables ex vivo reconstitution of fetal-specific T cell development, while bone marrow chimera technique allows in vivo reconstitution of T cell development in adult thymus. These techniques can be combined with retroviral gene transduction into the T cell progenitors to evaluate the function of genes of interest in developing T cells. Here, we describe the basic protocols for retrovirus gene transduction into fetal or adult T cell progenitors and reconstitution of thymic T cell development including experimental tips such as using cryopreserved fetal liver or bone marrow cells as sources of T cell progenitors.
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12
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Apavaloaei A, Brochu S, Dong M, Rouette A, Hardy MP, Villafano G, Murata S, Melichar HJ, Perreault C. PSMB11 Orchestrates the Development of CD4 and CD8 Thymocytes via Regulation of Gene Expression in Cortical Thymic Epithelial Cells. THE JOURNAL OF IMMUNOLOGY 2018; 202:966-978. [PMID: 30567730 DOI: 10.4049/jimmunol.1801288] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 11/16/2018] [Indexed: 12/16/2022]
Abstract
T cell development depends on sequential interactions of thymocytes with cortical thymic epithelial cells (cTECs) and medullary thymic epithelial cells. PSMB11 is a catalytic proteasomal subunit present exclusively in cTECs. Because proteasomes regulate transcriptional activity, we asked whether PSMB11 might affect gene expression in cTECs. We report that PSMB11 regulates the expression of 850 cTEC genes that modulate lymphostromal interactions primarily via the WNT signaling pathway. cTECs from Psmb11 -/- mice 1) acquire features of medullary thymic epithelial cells and 2) retain CD8 thymocytes in the thymic cortex, thereby impairing phase 2 of positive selection, 3) perturbing CD8 T cell development, and 4) causing dramatic oxidative stress leading to apoptosis of CD8 thymocytes. Deletion of Psmb11 also causes major oxidative stress in CD4 thymocytes. However, CD4 thymocytes do not undergo apoptosis because, unlike CD8 thymocytes, they upregulate expression of chaperones and inhibitors of apoptosis. We conclude that PSMB11 has pervasive effects on both CD4 and CD8 thymocytes via regulation of gene expression in cTECs.
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Affiliation(s)
- Anca Apavaloaei
- Institute for Research in Immunology and Cancer, Montreal, Quebec H3C 3J7, Canada.,Department of Medicine, University of Montreal, Montreal, Quebec H3C 3J7, Canada
| | - Sylvie Brochu
- Institute for Research in Immunology and Cancer, Montreal, Quebec H3C 3J7, Canada
| | - Mengqi Dong
- Department of Medicine, University of Montreal, Montreal, Quebec H3C 3J7, Canada.,Maisonneuve-Rosemont Hospital Research Center, Montreal, Quebec H1T 2M4, Canada
| | - Alexandre Rouette
- Institute for Research in Immunology and Cancer, Montreal, Quebec H3C 3J7, Canada.,Department of Medicine, University of Montreal, Montreal, Quebec H3C 3J7, Canada
| | - Marie-Pierre Hardy
- Institute for Research in Immunology and Cancer, Montreal, Quebec H3C 3J7, Canada
| | - Geno Villafano
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269; and
| | - Shigeo Murata
- Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo 113-0033, Japan
| | - Heather J Melichar
- Department of Medicine, University of Montreal, Montreal, Quebec H3C 3J7, Canada.,Maisonneuve-Rosemont Hospital Research Center, Montreal, Quebec H1T 2M4, Canada
| | - Claude Perreault
- Institute for Research in Immunology and Cancer, Montreal, Quebec H3C 3J7, Canada; .,Department of Medicine, University of Montreal, Montreal, Quebec H3C 3J7, Canada
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13
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Yasutomo K. Dysregulation of immunoproteasomes in autoinflammatory syndromes. Int Immunol 2018; 31:631-637. [DOI: 10.1093/intimm/dxy059] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 08/30/2018] [Indexed: 12/30/2022] Open
Abstract
Abstract
Immunoproteasomes degrade ubiquitin-coupled proteins and play a role in creating peptides for presentation by MHC class I proteins. Studies of gene-deficient mice, in which each immunoproteasomal subunit was affected, have demonstrated that dysfunction of immunoproteasomes leads to immunodeficiency, i.e. reduced expression of MHC class I and attenuation of CD8 T-cell responses. Recent studies, however, have uncovered a new type of autoinflammatory syndrome characterized by fever, nodular erythema and progressive partial lipodystrophy that is caused by genetic mutations in immunoproteasome subunits. These mutations disturbed the assembly of immunoproteasomes, which led to reduced proteasomal activity and thus accumulation of ubiquitin-coupled proteins. Those findings suggest that immunoproteasomes function as anti-inflammatory machinery in humans. The discovery of a new type of autoinflammatory syndrome caused by dysregulated immunoproteasomes provides novel insights into the important roles of immunoproteasomes in inflammation as well as the spectrum of autoinflammatory diseases.
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Affiliation(s)
- Koji Yasutomo
- Department of Immunology & Parasitology, Graduate School of Medicine, Tokushima University, Kuramoto, Tokushima, Japan
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14
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The immunoproteasome and thymoproteasome: functions, evolution and human disease. Nat Immunol 2018; 19:923-931. [PMID: 30104634 DOI: 10.1038/s41590-018-0186-z] [Citation(s) in RCA: 193] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 07/12/2018] [Accepted: 07/19/2018] [Indexed: 01/12/2023]
Abstract
The basic principle of adaptive immunity is to strictly discriminate between self and non-self, and a central challenge to overcome is the enormous variety of pathogens that might be encountered. In cell-mediated immunity, immunological discernment takes place at a molecular or cellular level. Central to both mechanisms of discernment is the generation of antigenic peptides associated with MHC class I molecules, which is achieved by a proteolytic complex called the proteasome. To adequately accomplish the discrimination between self and non-self that is essential for adaptive immunity and self-tolerance, two proteasome subtypes have evolved via gene duplication: the immunoproteasome and the thymoproteasome. In this Review, we describe various aspects of these immunity-dedicated proteasomes, from their discovery to recent findings.
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15
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Cheng M, Anderson MS. Thymic tolerance as a key brake on autoimmunity. Nat Immunol 2018; 19:659-664. [PMID: 29925986 PMCID: PMC6370479 DOI: 10.1038/s41590-018-0128-9] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 02/20/2018] [Indexed: 12/11/2022]
Abstract
Although the thymus has long been recognized as a key organ for T cell selection, the intricate details linking these selection events to human autoimmunity have been challenging to decipher. Over the last two decades, there has been rapid progress in understanding the role of thymic tolerance mechanisms in autoimmunity through genetics. Here we review some of the recent progress in understanding key thymic tolerance processes that are critical for preventing autoimmune disease.
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Affiliation(s)
- Mickie Cheng
- Diabetes Center, University of California, San Francisco, San Francisco, CA, USA
| | - Mark S Anderson
- Diabetes Center, University of California, San Francisco, San Francisco, CA, USA.
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