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Huang E, Frydman C, Xiao X. Navigating the landscape of epitranscriptomics and host immunity. Genome Res 2024; 34:515-529. [PMID: 38702197 PMCID: PMC11146601 DOI: 10.1101/gr.278412.123] [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: 05/06/2024]
Abstract
RNA modifications, also termed epitranscriptomic marks, encompass chemical alterations to individual nucleotides, including processes such as methylation and editing. These marks contribute to a wide range of biological processes, many of which are related to host immune system defense. The functions of immune-related RNA modifications can be categorized into three main groups: regulation of immunogenic RNAs, control of genes involved in innate immune response, and facilitation of adaptive immunity. Here, we provide an overview of recent research findings that elucidate the contributions of RNA modifications to each of these processes. We also discuss relevant methods for genome-wide identification of RNA modifications and their immunogenic substrates. Finally, we highlight recent advances in cancer immunotherapies that aim to reduce cancer cell viability by targeting the enzymes responsible for RNA modifications. Our presentation of these dynamic research avenues sets the stage for future investigations in this field.
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Affiliation(s)
- Elaine Huang
- Bioinformatics Interdepartmental Program, University of California, Los Angeles, California 90095, USA
| | - Clara Frydman
- Bioinformatics Interdepartmental Program, University of California, Los Angeles, California 90095, USA
| | - Xinshu Xiao
- Bioinformatics Interdepartmental Program, University of California, Los Angeles, California 90095, USA;
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California 90095, USA
- Molecular Biology Interdepartmental Program, University of California, Los Angeles, California 90095, USA
- Molecular Biology Institute, University of California, Los Angeles, California 90095, USA
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2
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Perrino M, Voulaz E, Balin S, Cazzato G, Fontana E, Franzese S, Defendi M, De Vincenzo F, Cordua N, Tamma R, Borea F, Aliprandi M, Airoldi M, Cecchi LG, Fazio R, Alloisio M, Marulli G, Santoro A, Di Tommaso L, Ingravallo G, Russo L, Da Rin G, Villa A, Della Bella S, Zucali PA, Mavilio D. Autoimmunity in thymic epithelial tumors: a not yet clarified pathologic paradigm associated with several unmet clinical needs. Front Immunol 2024; 15:1288045. [PMID: 38629065 PMCID: PMC11018877 DOI: 10.3389/fimmu.2024.1288045] [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: 09/03/2023] [Accepted: 01/29/2024] [Indexed: 04/19/2024] Open
Abstract
Thymic epithelial tumors (TETs) are rare mediastinal cancers originating from the thymus, classified in two main histotypes: thymoma and thymic carcinoma (TC). TETs affect a primary lymphoid organ playing a critical role in keeping T-cell homeostasis and ensuring an adequate immunological tolerance against "self". In particular, thymomas and not TC are frequently associated with autoimmune diseases (ADs), with Myasthenia Gravis being the most common AD present in 30% of patients with thymoma. This comorbidity, in addition to negatively affecting the quality and duration of patients' life, reduces the spectrum of the available therapeutic options. Indeed, the presence of autoimmunity represents an exclusion criteria for the administration of the newest immunotherapeutic treatments with checkpoint inhibitors. The pathophysiological correlation between TETs and autoimmunity remains a mystery. Several studies have demonstrated the presence of a residual and active thymopoiesis in adult patients affected by thymomas, especially in mixed and lymphocytic-rich thymomas, currently known as type AB and B thymomas. The aim of this review is to provide the state of art in regard to the histological features of the different TET histotype, to the role of the different immune cells infiltrating tumor microenvironments and their impact in the break of central immunologic thymic tolerance in thymomas. We discuss here both cellular and molecular immunologic mechanisms inducing the onset of autoimmunity in TETs, limiting the portfolio of therapeutic strategies against TETs and greatly impacting the prognosis of associated autoimmune diseases.
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Affiliation(s)
- Matteo Perrino
- Department of Medical Oncology and Hematology, IRCCS Humanitas Research Hospital, Milan, Italy
| | - Emanuele Voulaz
- Division of Thoracic Surgery, IRCCS Humanitas Research Hospital, Milan, Italy
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
| | - Simone Balin
- Department of Medical Biotechnologies and Translational Medicine, University of Milan, Milan, Italy
| | - Gerardo Cazzato
- Section of Pathology, Department of Precision and Regenerative Medicine and Ionian Area (DiMePRe-J), University of Bari “Aldo Moro”, Bari, Italy
| | - Elena Fontana
- Istituto di Ricerca Genetica e Biomedica (IRGB), National Research Council (CNR), Milan, Italy
- Human Genome and Biomedical Technologies Unit, IRCCS Humanitas Research Hospital, Milan, Italy
| | - Sara Franzese
- Department of Medical Biotechnologies and Translational Medicine, University of Milan, Milan, Italy
- Unit of Clinical and Experimental Immunology, IRCCS Humanitas Research Hospital, Milan, Italy
| | - Martina Defendi
- Department of Medical Biotechnologies and Translational Medicine, University of Milan, Milan, Italy
- Unit of Clinical and Experimental Immunology, IRCCS Humanitas Research Hospital, Milan, Italy
| | - Fabio De Vincenzo
- Department of Medical Oncology and Hematology, IRCCS Humanitas Research Hospital, Milan, Italy
| | - Nadia Cordua
- Department of Medical Oncology and Hematology, IRCCS Humanitas Research Hospital, Milan, Italy
| | - Roberto Tamma
- Section of Human Anatomy and Histology, Department of Translational Biomedicine and Neurosciences (DiBraiN), University of Bari “Aldo Moro”, Bari, Italy
| | - Federica Borea
- Department of Medical Oncology and Hematology, IRCCS Humanitas Research Hospital, Milan, Italy
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
| | - Marta Aliprandi
- Department of Medical Oncology and Hematology, IRCCS Humanitas Research Hospital, Milan, Italy
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
| | - Marco Airoldi
- Department of Medical Oncology and Hematology, IRCCS Humanitas Research Hospital, Milan, Italy
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
| | - Luigi Giovanni Cecchi
- Department of Medical Oncology and Hematology, IRCCS Humanitas Research Hospital, Milan, Italy
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
| | - Roberta Fazio
- Department of Medical Oncology and Hematology, IRCCS Humanitas Research Hospital, Milan, Italy
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
| | - Marco Alloisio
- Division of Thoracic Surgery, IRCCS Humanitas Research Hospital, Milan, Italy
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
| | - Giuseppe Marulli
- Division of Thoracic Surgery, IRCCS Humanitas Research Hospital, Milan, Italy
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
| | - Armando Santoro
- Department of Medical Oncology and Hematology, IRCCS Humanitas Research Hospital, Milan, Italy
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
| | - Luca Di Tommaso
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
- Department of Pathology, IRCCS Humanitas Research Hospital, Milan, Italy
| | - Giuseppe Ingravallo
- Section of Pathology, Department of Precision and Regenerative Medicine and Ionian Area (DiMePRe-J), University of Bari “Aldo Moro”, Bari, Italy
| | - Laura Russo
- Clinical Laboratory, IRCCS Humanitas Research Hospital, Milan, Italy
| | - Giorgio Da Rin
- Clinical Laboratory, IRCCS Humanitas Research Hospital, Milan, Italy
| | - Anna Villa
- Istituto di Ricerca Genetica e Biomedica (IRGB), National Research Council (CNR), Milan, Italy
- San Raffaele Telethon Institute for Gene Therapy (SR-TIGET), IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Silvia Della Bella
- Department of Medical Biotechnologies and Translational Medicine, University of Milan, Milan, Italy
- Unit of Clinical and Experimental Immunology, IRCCS Humanitas Research Hospital, Milan, Italy
| | - Paolo Andrea Zucali
- Department of Medical Oncology and Hematology, IRCCS Humanitas Research Hospital, Milan, Italy
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
| | - Domenico Mavilio
- Department of Medical Biotechnologies and Translational Medicine, University of Milan, Milan, Italy
- Unit of Clinical and Experimental Immunology, IRCCS Humanitas Research Hospital, Milan, Italy
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3
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Yu H, Yang W, Cao M, Lei Q, Yuan R, Xu H, Cui Y, Chen X, Su X, Zhuo H, Lin L. Mechanism study of ubiquitination in T cell development and autoimmune disease. Front Immunol 2024; 15:1359933. [PMID: 38562929 PMCID: PMC10982411 DOI: 10.3389/fimmu.2024.1359933] [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: 12/22/2023] [Accepted: 02/19/2024] [Indexed: 04/04/2024] Open
Abstract
T cells play critical role in multiple immune processes including antigen response, tumor immunity, inflammation, self-tolerance maintenance and autoimmune diseases et. Fetal liver or bone marrow-derived thymus-seeding progenitors (TSPs) settle in thymus and undergo T cell-lineage commitment, proliferation, T cell receptor (TCR) rearrangement, and thymic selections driven by microenvironment composed of thymic epithelial cells (TEC), dendritic cells (DC), macrophage and B cells, thus generating T cells with diverse TCR repertoire immunocompetent but not self-reactive. Additionally, some self-reactive thymocytes give rise to Treg with the help of TEC and DC, serving for immune tolerance. The sequential proliferation, cell fate decision, and selection during T cell development and self-tolerance establishment are tightly regulated to ensure the proper immune response without autoimmune reaction. There are remarkable progresses in understanding of the regulatory mechanisms regarding ubiquitination in T cell development and the establishment of self-tolerance in the past few years, which holds great potential for further therapeutic interventions in immune-related diseases.
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Affiliation(s)
- Hui Yu
- Department of Urology, Medical Research Center, Department of Neurosurgery, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, The Second Chengdu Hospital Affiliated to Chongqing Medical University, Chengdu, China
| | - Wenyong Yang
- Department of Urology, Medical Research Center, Department of Neurosurgery, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, The Second Chengdu Hospital Affiliated to Chongqing Medical University, Chengdu, China
| | - Min Cao
- Department of Urology, Medical Research Center, Department of Neurosurgery, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, The Second Chengdu Hospital Affiliated to Chongqing Medical University, Chengdu, China
| | - Qingqiang Lei
- Department of Urology, Medical Research Center, Department of Neurosurgery, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, The Second Chengdu Hospital Affiliated to Chongqing Medical University, Chengdu, China
| | - Renbin Yuan
- Department of Urology, Medical Research Center, Department of Neurosurgery, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, The Second Chengdu Hospital Affiliated to Chongqing Medical University, Chengdu, China
| | - He Xu
- Department of Urology, Medical Research Center, Department of Neurosurgery, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, The Second Chengdu Hospital Affiliated to Chongqing Medical University, Chengdu, China
| | - Yuqian Cui
- Department of Urology, Medical Research Center, Department of Neurosurgery, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, The Second Chengdu Hospital Affiliated to Chongqing Medical University, Chengdu, China
| | - Xuerui Chen
- Department of Urology, Medical Research Center, Department of Neurosurgery, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, The Second Chengdu Hospital Affiliated to Chongqing Medical University, Chengdu, China
| | - Xu Su
- Department of Urology, Medical Research Center, Department of Neurosurgery, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, The Second Chengdu Hospital Affiliated to Chongqing Medical University, Chengdu, China
- College of Medicine, Southwest Jiaotong University, Chengdu, China
| | - Hui Zhuo
- Department of Urology, Medical Research Center, Department of Neurosurgery, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, The Second Chengdu Hospital Affiliated to Chongqing Medical University, Chengdu, China
| | - Liangbin Lin
- Department of Urology, Medical Research Center, Department of Neurosurgery, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, The Second Chengdu Hospital Affiliated to Chongqing Medical University, Chengdu, China
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4
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Filipp D, Manning J, Petrusová J. Extrathymic AIRE-Expressing Cells: A Historical Perspective. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024; 1444:33-49. [PMID: 38467971 DOI: 10.1007/978-981-99-9781-7_3] [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
Since its discovery, Aire has been the topic of numerous studies in its role as a transcriptional regulator in the thymus where it promotes the "promiscuous" expression of a large repertoire of tissue-restricted antigens (TRAs) that are normally expressed only in the immune periphery. This process occurs in specialized medullary thymic epithelial cells (mTECs) and mediates the elimination of self-reactive T cells or promotes their conversion to the Foxp3+ regulatory T cell lineage, both of which are required for the prevention of autoimmunity. In recent years, there has been increasing interest in the role of extrathymic Aire expression in peripheral organs. The focus has primarily been on the identification of the cellular source(s) and mechanism(s) by which extrathymic AIRE affects tolerance-related or other physiological processes. A cadre of OMICs tools including single cell RNA sequencing and novel transgenic models to trace Aire expression to perform lineage tracing experiments have shed light on a phenomenon that is more complex than previously thought. In this chapter, we provide a deeper analysis of how extrathymic Aire research has developed and progressed, how cellular sources were identified, and how the function of AIRE was determined. Current data suggests that extrathymic AIRE fulfills a function that differs from what has been observed in the thymus and strongly argues that its main purpose is to regulate transcriptional programs in a cell content-dependent manner. Surprisingly, there is data that also suggests a non-transcriptional role of extrathymic AIRE in the cytoplasm. We have arrived at a potential turning point that will take the field from the classical understanding of AIRE as a transcription factor in control of TRA expression to its role in immunological and non-immunological processes in the periphery.
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Affiliation(s)
- Dominik Filipp
- 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
| | - Jana Petrusová
- Laboratory of Immunobiology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
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Aytekin ES, Cagdas D. APECED and the place of AIRE in the puzzle of the immune network associated with autoimmunity. Scand J Immunol 2023; 98:e13299. [PMID: 38441333 DOI: 10.1111/sji.13299] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 04/27/2023] [Accepted: 05/03/2023] [Indexed: 03/07/2024]
Abstract
In the last 20 years, discoveries about the autoimmune regulator (AIRE) protein and its critical role in immune tolerance have provided fundamental insights into understanding the molecular basis of autoimmunity. This review provides a comprehensive overview of the effect of AIRE on immunological tolerance and the characteristics of autoimmune diseases in Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy (APECED), which is caused by biallelic AIRE mutations. A better understanding of the immunological mechanisms of AIRE deficiency may enlighten immune tolerance mechanisms and new diagnostic and treatment strategies for autoimmune diseases. Considering that not all clinical features of APECED are present in a given follow-up period, the diagnosis is not easy in a patient at the first visit. Longer follow-up and a multidisciplinary approach are essential for diagnosis. It is challenging to prevent endocrine and other organ damage compared with other diseases associated with multiple autoimmunities, such as FOXP3, LRBA, and CTLA4 deficiencies. Unfortunately, no curative therapy like haematopoietic stem cell transplantation or specific immunomodulation is present that is successful in the treatment.
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Affiliation(s)
- Elif Soyak Aytekin
- Pediatric Allergy and Immunology, Department of Pediatrics, SBU Dr. Sami Ulus Children Hospital, Ankara, Turkey
| | - Deniz Cagdas
- Division of Pediatric Immunology, Department of Pediatrics, Ihsan Dogramaci Children`s Hospital, Institute of Child Health, Hacettepe University Medical School, Ankara, Turkey
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6
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Park MJ, Jeong E, Lee EJ, Choi HJ, Moon BH, Kang K, Chang S. RNA Editing Enzyme ADAR1 Suppresses the Mobility of Cancer Cells via ARPIN. Mol Cells 2023; 46:351-359. [PMID: 36921992 PMCID: PMC10258462 DOI: 10.14348/molcells.2023.2174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 01/05/2023] [Accepted: 01/15/2023] [Indexed: 03/17/2023] Open
Abstract
Deamination of adenine or cytosine in RNA, called RNA editing, is a constitutively active and common modification. The primary role of RNA editing is tagging RNA right after its synthesis so that the endogenous RNA is recognized as self and distinguished from exogenous RNA, such as viral RNA. In addition to this primary function, the direct or indirect effects on gene expression can be utilized in cancer where a high level of RNA editing activity persists. This report identified actin-related protein 2/3 complex inhibitor (ARPIN) as a target of ADAR1 in breast cancer cells. Our comparative RNA sequencing analysis in MCF7 cells revealed that the expression of ARPIN was decreased upon ADAR1 depletion with altered editing on its 3'UTR. However, the expression changes of ARPIN were not dependent on 3'UTR editing but relied on three microRNAs acting on ARPIN. As a result, we found that the migration and invasion of cancer cells were profoundly increased by ADAR1 depletion, and this cellular phenotype was reversed by the exogenous ARPIN expression. Altogether, our data suggest that ADAR1 suppresses breast cancer cell mobility via the upregulation of ARPIN.
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Affiliation(s)
- Min Ji Park
- Department of Biomedical Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Eunji Jeong
- Department of Biomedical Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Eun Ji Lee
- Department of Biomedical Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Hyeon Ji Choi
- Department of Biomedical Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Bo Hyun Moon
- Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Keunsoo Kang
- Department of Microbiology, College of Science & Technology, Dankook University, Cheonan 31116, Korea
| | - Suhwan Chang
- Department of Biomedical Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
- Department of Physiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
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7
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AIRE in Male Fertility: A New Hypothesis. Cells 2022; 11:cells11193168. [PMID: 36231130 PMCID: PMC9563308 DOI: 10.3390/cells11193168] [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: 09/12/2022] [Revised: 09/29/2022] [Accepted: 10/08/2022] [Indexed: 11/16/2022] Open
Abstract
Male infertility affects approximately 14% of all European men, of which ~44% are characterized as idiopathic. There is an urgency to identify the factors that affect male fertility. One such factor, Autoimmune Regulator (AIRE), a protein found in the thymus, has been studied in the context of central tolerance functioning as a nuclear transcription modulator, responsible for the expression of tissue-restricted antigens in specialized thymic cells that prevent autoimmunity. While its expression in the testes remains enigmatic, we recently observed that sterility in mice correlates with the absence of Aire in the testes, regardless of the deficient expression in medullary thymic epithelial cells or cells of the hematopoietic system. By assessing the Aire transcript levels, we discovered that Sertoli cells are the exclusive source of Aire in the testes, where it most likely plays a non-immune role, suggesting an unknown mechanism by which testicular Aire regulates fertility. Here, we discuss these results in the context of previous reports which have suggested that infertility observed in Aire deficient mice is of an autoimmune aetiology. We present an alternative point of view for the role of Aire in testes in respect to fertility altering the perspective of how Aire's function in the testes is currently perceived.
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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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Complexification of eukaryote phenotype: Adaptive immuno-cognitive systems as unique Gödelian block chain distributed ledger. Biosystems 2022; 220:104718. [PMID: 35803502 DOI: 10.1016/j.biosystems.2022.104718] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 06/03/2022] [Accepted: 06/03/2022] [Indexed: 12/26/2022]
Abstract
The digitization of inheritable information in the genome has been called the 'algorithmic take-over of biology'. The McClintock discovery that viral software based transposable elements that conduct cut-paste (transposon) and copy-paste (retrotransposon) operations are needed for genomic evolvability underscores the truism that only software can change software and also that viral hacking by internal and external bio-malware is the Achilles heel of genomic digital systems. There was a paradigm shift in genomic information processing with the Adaptive Immune System (AIS) 500 mya followed by the Mirror Neuron System (MNS), latterly mostly in primate brains, which reaches its apogee in human social cognition. The AIS and MNS involve distinctive Gödelian features of self-reference (Self-Ref) and offline virtual self-representation (Self-Rep) for complex self-other interaction with prodigious open-ended capacity for anticipative malware detection and novelty production within a unique blockchain distributed ledger (BCDL). The role of self-referential information processing, often considered to be central to the sentient self with origins in the immune system 'Thymic self', is shown to be part of the Gödel logic behind a generator-selector framework at a molecular level, which exerts stringent selection criteria to maintain genomic BCDL. The latter manifests digital and decentralized record keeping where no internal or external bio-malware can compromise the immutability of the life's building blocks and no novel blocks can be added that is not consistent with extant blocks. This is demonstrated with regard to somatic hypermutation with novel anti-body production in the face of external non-self antigen attacks.
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Provin N, Giraud M. Differentiation of Pluripotent Stem Cells Into Thymic Epithelial Cells and Generation of Thymic Organoids: Applications for Therapeutic Strategies Against APECED. Front Immunol 2022; 13:930963. [PMID: 35844523 PMCID: PMC9277542 DOI: 10.3389/fimmu.2022.930963] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 05/26/2022] [Indexed: 01/01/2023] Open
Abstract
The thymus is a primary lymphoid organ essential for the induction of central immune tolerance. Maturing T cells undergo several steps of expansion and selection mediated by thymic epithelial cells (TECs). In APECED and other congenital pathologies, a deficiency in genes that regulate TEC development or their ability to select non auto-reactive thymocytes results in a defective immune balance, and consequently in a general autoimmune syndrome. Restoration of thymic function is thus crucial for the emergence of curative treatments. The last decade has seen remarkable progress in both gene editing and pluripotent stem cell differentiation, with the emergence of CRISPR-based gene correction, the trivialization of reprogramming of somatic cells to induced pluripotent stem cells (iPSc) and their subsequent differentiation into multiple cellular fates. The combination of these two approaches has paved the way to the generation of genetically corrected thymic organoids and their use to control thymic genetic pathologies affecting self-tolerance. Here we review the recent advances in differentiation of iPSc into TECs and the ability of the latter to support a proper and efficient maturation of thymocytes into functional and non-autoreactive T cells. A special focus is given on thymus organogenesis and pathway modulation during iPSc differentiation, on the impact of the 2/3D structure on the generated TECs, and on perspectives for therapeutic strategies in APECED based on patient-derived iPSc corrected for AIRE gene mutations.
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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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12
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Tassinari V, Cerboni C, Soriani A. Self or Non-Self? It Is also a Matter of RNA Recognition and Editing by ADAR1. BIOLOGY 2022; 11:biology11040568. [PMID: 35453767 PMCID: PMC9024829 DOI: 10.3390/biology11040568] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 04/01/2022] [Accepted: 04/06/2022] [Indexed: 01/19/2023]
Abstract
Simple Summary A fundamental feature of innate immune cells is to detect the presence of non-self, such as potentially harmful nucleic acids, by germline-encoded specialized receptors called pattern recognition receptors (PRRs). ADAR1 is one key enzyme avoiding aberrant type I interferon (IFN-I) production and immune cell activation by the conversion of adenosine to inosine (A-to-I) in double-stranded RNA (dsRNA) structures that arise in self mRNA containing specific repetitive elements. This review intends to give an up-to-date and detailed overview of the ADAR1-mediated ability to modulate the immune response in autoimmune diseases and cancer progression. Abstract A-to-I editing is a post-transcriptional mechanism affecting coding and non-coding dsRNAs, catalyzed by the adenosine deaminases acting on the RNA (ADAR) family of enzymes. A-to-I modifications of endogenous dsRNA (mainly derived from Alu repetitive elements) prevent their recognition by cellular dsRNA sensors, thus avoiding the induction of antiviral signaling and uncontrolled IFN-I production. This process, mediated by ADAR1 activity, ensures the activation of an innate immune response against foreign (non-self) but not self nucleic acids. As a consequence, ADAR1 mutations or its de-regulated activity promote the development of autoimmune diseases and strongly impact cell growth, also leading to cancer. Moreover, the excessive inflammation promoted by Adar1 ablation also impacts T and B cell maturation, as well as the development of dendritic cell subsets, revealing a new role of ADAR1 in the homeostasis of the immune system.
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13
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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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14
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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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15
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Shevyrev D, Tereshchenko V, Kozlov V, Sennikov S. Phylogeny, Structure, Functions, and Role of AIRE in the Formation of T-Cell Subsets. Cells 2022; 11:194. [PMID: 35053310 PMCID: PMC8773594 DOI: 10.3390/cells11020194] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 01/03/2022] [Accepted: 01/04/2022] [Indexed: 02/06/2023] Open
Abstract
It is well known that the most important feature of adaptive immunity is the specificity that provides highly precise recognition of the self, altered-self, and non-self. Due to the high specificity of antigen recognition, the adaptive immune system participates in the maintenance of genetic homeostasis, supports multicellularity, and protects an organism from different pathogens at a qualitatively different level than innate immunity. This seemingly simple property is based on millions of years of evolution that led to the formation of diversification mechanisms of antigen-recognizing receptors and later to the emergence of a system of presentation of the self and non-self antigens. The latter could have a crucial significance because the presentation of nearly complete diversity of auto-antigens in the thymus allows for the "calibration" of the forming repertoires of T-cells for the recognition of self, altered-self, and non-self antigens that are presented on the periphery. The central role in this process belongs to promiscuous gene expression by the thymic epithelial cells that express nearly the whole spectrum of proteins encoded in the genome, meanwhile maintaining their cellular identity. This complex mechanism requires strict control that is executed by several transcription factors. One of the most important of them is AIRE. This noncanonical transcription factor not only regulates the processes of differentiation and expression of peripheral tissue-specific antigens in the thymic medullar epithelial cells but also controls intercellular interactions in the thymus. Besides, it participates in an increase in the diversity and transfer of presented antigens and thus influences the formation of repertoires of maturing thymocytes. Due to these complex effects, AIRE is also called a transcriptional regulator. In this review, we briefly described the history of AIRE discovery, its structure, functions, and role in the formation of antigen-recognizing receptor repertoires, along with other transcription factors. We focused on the phylogenetic prerequisites for the development of modern adaptive immunity and emphasized the importance of the antigen presentation system.
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Affiliation(s)
- Daniil Shevyrev
- Research Institute for Fundamental and Clinical Immunology (RIFCI), 630099 Novosibirsk, Russia; (V.T.); (V.K.); (S.S.)
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16
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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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17
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Fotakis G, Trajanoski Z, Rieder D. Computational cancer neoantigen prediction: current status and recent advances. IMMUNO-ONCOLOGY TECHNOLOGY 2021; 12:100052. [PMID: 35755950 PMCID: PMC9216660 DOI: 10.1016/j.iotech.2021.100052] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Over the last few decades, immunotherapy has shown significant therapeutic efficacy in a broad range of cancer types. Antitumor immune responses are contingent on the recognition of tumor-specific antigens, which are termed neoantigens. Tumor neoantigens are ideal targets for immunotherapy since they can be recognized as non-self antigens by the host immune system and thus are able to elicit an antitumor T-cell response. There are an increasing number of studies that highlight the importance of tumor neoantigens in immunoediting and in the sensitivity to immune checkpoint blockade. Therefore, one of the most fundamental tasks in the field of immuno-oncology research is the identification of patient-specific neoantigens. To this end, a plethora of computational approaches have been developed in order to predict tumor-specific aberrant peptides and quantify their likelihood of binding to patients' human leukocyte antigen molecules in order to be recognized by T cells. In this review, we systematically summarize and present the most recent advances in computational neoantigen prediction, and discuss the challenges and novel methods that are being developed to resolve them. Tumors have the ability to acquire immune escape mechanisms. Tumor-specific aberrant peptides (neoantigens) can elicit an immune response by the host immune system. The identification of neoantigens is one of the most fundamental tasks in the field of immuno-oncology research. A plethora of computational approaches have been developed in order to predict patient-specificneoantigens.
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Affiliation(s)
- G Fotakis
- Institute of Bioinformatics, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Z Trajanoski
- Institute of Bioinformatics, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - D Rieder
- Institute of Bioinformatics, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
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18
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Tao Z, Jiang Y, Xia S. Regulation of thymic T regulatory cell differentiation by TECs in health and disease. Scand J Immunol 2021; 94:e13094. [PMID: 34780092 DOI: 10.1111/sji.13094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 07/26/2021] [Accepted: 07/27/2021] [Indexed: 12/22/2022]
Abstract
The thymus produces self-limiting and self-tolerant T cells through the interaction between thymocytes and thymus epithelial cells (TECs), thereby generating central immune tolerance. The TECs are composed of cortical and medullary thymic epithelial cells, which regulate the positive and negative selection of T cells, respectively. During the process of negative selection, thymocytes with self-reactive ability are deleted or differentiated into regulatory T cells (Tregs). Tregs are a subset of suppressor T cells that are important for maintaining immune homeostasis. The differentiation and development of Tregs depend on the development of TECs and other underlying molecular mechanisms. Tregs regulated by thymic epithelial cells are closely related to human health and are significant in autoimmune diseases, thymoma and pregnancy. In this review, we summarize the current molecular and transcriptional regulatory mechanisms by which TECs affect the development and function of thymic Tregs. We also review the pathophysiological models of thymic epithelial cells regulating thymic Tregs in human diseases and specific physiological conditions.
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Affiliation(s)
- Zehua Tao
- Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Yalan Jiang
- Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Sheng Xia
- Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, China
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19
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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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Ferrua F, Bortolomai I, Fontana E, Di Silvestre D, Rigoni R, Marcovecchio GE, Draghici E, Brambilla F, Castiello MC, Delfanti G, Moshous D, Picard C, Taghon T, Bordon V, Schulz AS, Schuetz C, Giliani S, Soresina A, Gennery AR, Signa S, Dávila Saldaña BJ, Delmonte OM, Notarangelo LD, Roifman CM, Poliani PL, Uva P, Mauri PL, Villa A, Bosticardo M. Thymic Epithelial Cell Alterations and Defective Thymopoiesis Lead to Central and Peripheral Tolerance Perturbation in MHCII Deficiency. Front Immunol 2021; 12:669943. [PMID: 34211466 PMCID: PMC8239840 DOI: 10.3389/fimmu.2021.669943] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 05/07/2021] [Indexed: 11/13/2022] Open
Abstract
Major Histocompatibility Complex (MHC) class II (MHCII) deficiency (MHCII-D), also known as Bare Lymphocyte Syndrome (BLS), is a rare combined immunodeficiency due to mutations in genes regulating expression of MHCII molecules. MHCII deficiency results in impaired cellular and humoral immune responses, leading to severe infections and autoimmunity. Abnormal cross-talk with developing T cells due to the absence of MHCII expression likely leads to defects in thymic epithelial cells (TEC). However, the contribution of TEC alterations to the pathogenesis of this primary immunodeficiency has not been well characterized to date, in particular in regard to immune dysregulation. To this aim, we have performed an in-depth cellular and molecular characterization of TEC in this disease. We observed an overall perturbation of thymic structure and function in both MHCII-/- mice and patients. Transcriptomic and proteomic profiling of murine TEC revealed several alterations. In particular, we demonstrated that impairment of lymphostromal cross-talk in the thymus of MHCII-/- mice affects mTEC maturation and promiscuous gene expression and causes defects of central tolerance. Furthermore, we observed peripheral tolerance impairment, likely due to defective Treg cell generation and/or function and B cell tolerance breakdown. Overall, our findings reveal disease-specific TEC defects resulting in perturbation of central tolerance and limiting the potential benefits of hematopoietic stem cell transplantation in MHCII deficiency.
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Affiliation(s)
- Francesca Ferrua
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan, Italy
- Pediatric Immunohematology and Bone Marrow Transplantation Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Vita-Salute San Raffaele University, Milan, Italy
| | - Ileana Bortolomai
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Elena Fontana
- Human Genome Department, Humanitas Clinical and Research Center, Rozzano, Milan, Italy
- Milan Unit, Institute of Genetic and Biomedical Research, National Research Council (CNR), Milan, Italy
| | - Dario Di Silvestre
- Department of Biomedical Sciences, Institute for Biomedical Technologies-National Research Council (CNR), Milan, Italy
| | - Rosita Rigoni
- Human Genome Department, Humanitas Clinical and Research Center, Rozzano, Milan, Italy
- Milan Unit, Institute of Genetic and Biomedical Research, National Research Council (CNR), Milan, Italy
| | - Genni Enza Marcovecchio
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Elena Draghici
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Francesca Brambilla
- Department of Biomedical Sciences, Institute for Biomedical Technologies-National Research Council (CNR), Milan, Italy
| | - Maria Carmina Castiello
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan, Italy
- Milan Unit, Institute of Genetic and Biomedical Research, National Research Council (CNR), Milan, Italy
| | - Gloria Delfanti
- Experimental Immunology Unit, Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Despina Moshous
- Department of Pediatric Immunology, Hematology and Rheumatology, Necker Children’s Hospital, AP-HP, Paris, France
- Laboratory “Genome Dynamics in the Immune System”, INSERM UMR1163, Université de Paris, Institut Imagine, Paris, France
| | - Capucine Picard
- Department of Pediatric Immunology, Hematology and Rheumatology, Necker Children’s Hospital, AP-HP, Paris, France
- Centre d’Etude des Déficits Immunitaires, Necker-Enfants Malades Hospital, AP-HP, Paris, France
- Laboratory of Lymphocyte Activation and Susceptibility to EBV infection, Inserm UMR 1163, University Paris Descartes Sorbonne Paris Cité, Imagine Institute, Paris, France
| | - Tom Taghon
- Department of Diagnostic Sciences, Ghent University Hospital, Ghent University, Ghent, Belgium
| | - Victoria Bordon
- Department of Pediatric Hematology, Oncology and Stem Cell Transplantation, Ghent University Hospital, Ghent, Belgium
| | - Ansgar S. Schulz
- Department of Pediatrics, University Medical Center Ulm, Ulm, Germany
| | - Catharina Schuetz
- Department of Pediatrics, University Medical Center Ulm, Ulm, Germany
- Department of Pediatrics, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Silvia Giliani
- Cytogenetics and Medical Genetics Unit and “A. Nocivelli” Institute for Molecular Medicine, Spedali Civili Hospital, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Annarosa Soresina
- Unit of Pediatric Immunology, Pediatrics Clinic, University of Brescia, ASST-Spedali Civili Brescia, Brescia, Italy
| | - Andrew R. Gennery
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
- Department of Pediatric Immunology and HSCT, Great North Children's Hospital, Newcastle upon Tyne, United Kingdom
| | - Sara Signa
- Department of Pediatric Immunology and HSCT, Great North Children's Hospital, Newcastle upon Tyne, United Kingdom
- Autoinflammatory Diseases and Immunodeficiencies Center, IRCCS Istituto G. Gaslini, and Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, and Maternal and Children's Sciences, University of Genoa, Genoa, Italy
| | - Blachy J. Dávila Saldaña
- Division of Blood and Marrow Transplantation, Children's National Hospital, Washington, DC, United States
| | - Ottavia M. Delmonte
- Laboratory of Clinical Immunology and Microbiology, NIAID, NIH, Bethesda, MD, United States
| | - Luigi D. Notarangelo
- Laboratory of Clinical Immunology and Microbiology, NIAID, NIH, Bethesda, MD, United States
| | - Chaim M. Roifman
- Division of Immunology & Allergy, Department of Pediatrics, The Hospital for Sick Children, the Canadian Centre for Primary Immunodeficiency and the University of Toronto, Toronto, ON, Canada
| | - Pietro Luigi Poliani
- Department of Molecular and Translational Medicine, Pathology Unit, University of Brescia, Brescia, Italy
| | - Paolo Uva
- CRS4, Science and Technology Park Polaris, Pula, Cagliari, Italy
| | - Pier Luigi Mauri
- Department of Biomedical Sciences, Institute for Biomedical Technologies-National Research Council (CNR), Milan, Italy
| | - Anna Villa
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan, Italy
- Milan Unit, Institute of Genetic and Biomedical Research, National Research Council (CNR), Milan, Italy
| | - Marita Bosticardo
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan, Italy
- Laboratory of Clinical Immunology and Microbiology, NIAID, NIH, Bethesda, MD, United States
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21
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Genomic Intelligence as Über Bio-Cybersecurity: The Gödel Sentence in Immuno-Cognitive Systems. ENTROPY 2021; 23:e23040405. [PMID: 33805411 PMCID: PMC8065710 DOI: 10.3390/e23040405] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 02/20/2021] [Accepted: 02/24/2021] [Indexed: 12/27/2022]
Abstract
This paper gives formal foundations and evidence from gene science in the post Barbara McClintock era that the Gödel Sentence, far from being an esoteric construction in mathematical logic, is ubiquitous in genomic intelligence that evolved with multi-cellular life. Conditions uniquely found in the Adaptive Immune System (AIS) and Mirror Neuron System (MNS), termed the genomic immuno-cognitive system, coincide with three building blocks in computation theory of Gödel, Turing and Post (G-T-P). (i) Biotic elements have unique digital identifiers with gene codes executing 3D self-assembly for morphology and regulation of the organism using the recursive operation of Self-Ref (Self-Reference) with the other being a self-referential projection of self. (ii) A parallel offline simulation meta/mirror environment in 1–1 relation to online machine executions of self-codes gives G-T-P Self-Rep (Self-Representation). (iii) This permits a digital biotic entity to self-report that it is under attack by a biotic malware or non-self antigen in the format of the Gödel sentence, resulting in the “smarts” for contextual novelty production. The proposed unitary G-T-P recursive machinery in AIS and in MNS for social cognition yields a new explanation that the Interferon Gamma factor, known for friend-foe identification in AIS, is also integral to social behaviors. New G-T-P bio-informatics of AIS and novel anti-body production is given with interesting testable implications for COVID-19 pathology.
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22
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Besnard M, Padonou F, Provin N, Giraud M, Guillonneau C. AIRE deficiency, from preclinical models to human APECED disease. Dis Model Mech 2021; 14:dmm046359. [PMID: 33729987 PMCID: PMC7875492 DOI: 10.1242/dmm.046359] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED) is a rare life-threatening autoimmune disease that attacks multiple organs and has its onset in childhood. It is an inherited condition caused by a variety of mutations in the autoimmune regulator (AIRE) gene that encodes a protein whose function has been uncovered by the generation and study of Aire-KO mice. These provided invaluable insights into the link between AIRE expression in medullary thymic epithelial cells (mTECs), and the broad spectrum of self-antigens that these cells express and present to the developing thymocytes. However, these murine models poorly recapitulate all phenotypic aspects of human APECED. Unlike Aire-KO mice, the recently generated Aire-KO rat model presents visual features, organ lymphocytic infiltrations and production of autoantibodies that resemble those observed in APECED patients, making the rat model a main research asset. In addition, ex vivo models of AIRE-dependent self-antigen expression in primary mTECs have been successfully set up. Thymus organoids based on pluripotent stem cell-derived TECs from APECED patients are also emerging, and constitute a promising tool to engineer AIRE-corrected mTECs and restore the generation of regulatory T cells. Eventually, these new models will undoubtedly lead to main advances in the identification and assessment of specific and efficient new therapeutic strategies aiming to restore immunological tolerance in APECED patients.
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Affiliation(s)
- Marine Besnard
- Université de Nantes, Inserm, CNRS, Centre de Recherche en Transplantation et Immunologie, UMR 1064, ITUN, F-44000 Nantes, France
| | - Francine Padonou
- Université de Nantes, Inserm, CNRS, Centre de Recherche en Transplantation et Immunologie, UMR 1064, ITUN, F-44000 Nantes, France
| | - Nathan Provin
- Université de Nantes, Inserm, CNRS, Centre de Recherche en Transplantation et Immunologie, UMR 1064, ITUN, F-44000 Nantes, France
| | - Matthieu Giraud
- Université de Nantes, Inserm, CNRS, Centre de Recherche en Transplantation et Immunologie, UMR 1064, ITUN, F-44000 Nantes, France
| | - Carole Guillonneau
- Université de Nantes, Inserm, CNRS, Centre de Recherche en Transplantation et Immunologie, UMR 1064, ITUN, F-44000 Nantes, France
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23
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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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24
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Salaman MR, Gould KG. Breakdown of T-cell ignorance: The tolerance failure responsible for mainstream autoimmune diseases? J Transl Autoimmun 2020; 3:100070. [PMID: 33294833 PMCID: PMC7695872 DOI: 10.1016/j.jtauto.2020.100070] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 11/07/2020] [Accepted: 11/09/2020] [Indexed: 12/31/2022] Open
Abstract
This article explores the possibility that the major autoimmune diseases come about because of the breakdown of T lymphocyte ignorance – that state in which antigen and lymphocyte have never come together in such a way as to induce tolerance or an immune response. By use of transgenic technique to place a foreign antigen/peptide in various mouse tissues the widespread occurrence of ignorance has been observed and information obtained on when it is likely to occur. Now, with the advent of tetramer technique to enrich specific T cells and the recognition of lymphocyte markers indicating whether or not antigen interaction has taken place, ignorance of genuine self-antigens is being examined in mouse and man. In the absence of thymic deletion it seems that tolerance to self-antigens is brought about either by T cell ignorance or T cell regulatory control. The initiating factor in these major diseases is likely to be a change in the condition of the antigen leading to tolerance failure. There is evidence that it is ignorance that breaks down in Type 1 diabetes and systemic lupus erythematosus. If this proves a general rule, it may be because ignorance is the tolerance mechanism most vulnerable to subversion. T cell ignorance or regulation maintain self-tolerance when thymic deletion is absent. Increased antigen availability is the likely initiator of major autoimmune diseases. Altered antigen availability may result in breakdown of T cell ignorance. Loss of ignorance will lead to autoimmune disease unless T cell regulation steps in.
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Affiliation(s)
- Myer R. Salaman
- Corresponding author. Department of Infectious Disease, St Mary’s Campus, Imperial College, London, W2 1PG, UK.
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25
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Nakahama T, Kawahara Y. Adenosine-to-inosine RNA editing in the immune system: friend or foe? Cell Mol Life Sci 2020; 77:2931-2948. [PMID: 31996954 PMCID: PMC11104962 DOI: 10.1007/s00018-020-03466-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 12/27/2019] [Accepted: 01/14/2020] [Indexed: 12/19/2022]
Abstract
Our body expresses sensors to detect pathogens through the recognition of expressed molecules, including nucleic acids, lipids, and proteins, while immune tolerance prevents an overreaction with self and the development of autoimmune disease. Adenosine (A)-to-inosine (I) RNA editing, catalyzed by adenosine deaminases acting on RNA (ADARs), is a post-transcriptional modification that can potentially occur at over 100 million sites in the human genome, mainly in Alu repetitive elements that preferentially form a double-stranded RNA (dsRNA) structure. A-to-I conversion within dsRNA, which may induce a structural change, is required to escape from the host immune system, given that endogenous dsRNAs transcribed from Alu repetitive elements are potentially recognized by melanoma differentiation-associated protein 5 (MDA5) as non-self. Of note, loss-of-function mutations in the ADAR1 gene cause Aicardi-Goutières syndrome, a congenital autoimmune disease characterized by encephalopathy and a type I interferon (IFN) signature. However, the loss of ADAR1 in cancer cells with an IFN signature induces lethality via the activation of protein kinase R in addition to MDA5. This makes cells more sensitive to immunotherapy, highlighting the opposing immune status of autoimmune diseases (overreaction) and cancer (tolerance). In this review, we provide an overview of insights into two opposing aspects of RNA editing that functions as a modulator of the immune system in autoimmune diseases and cancer.
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Affiliation(s)
- Taisuke Nakahama
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Yukio Kawahara
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka, 565-0871, Japan.
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26
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Oliveira EH, Assis AF, Speck-Hernandez CA, Duarte MJ, Passos GA. Aire Gene Influences the Length of the 3' UTR of mRNAs in Medullary Thymic Epithelial Cells. Front Immunol 2020; 11:1039. [PMID: 32547551 PMCID: PMC7270294 DOI: 10.3389/fimmu.2020.01039] [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: 11/03/2019] [Accepted: 04/29/2020] [Indexed: 12/15/2022] Open
Abstract
Aire is a transcriptional controller in medullary thymic epithelial cells (mTECs) modulating a set of peripheral tissue antigens (PTAs) and non-PTA mRNAs as well as miRNAs. Even miRNAs exerting posttranscriptional control of mRNAs in mTECs, the composition of miRNA-mRNA networks may differ. Under reduction in Aire expression, networks exhibited greater miRNA diversity controlling mRNAs. Variations in the number of 3'UTR binding sites of Aire-dependent mRNAs may represent a crucial factor that influence the miRNA interaction. To test this hypothesis, we analyzed through bioinformatics the length of 3'UTRs of a large set of Aire-dependent mRNAs. The data were obtained from existing RNA-seq of mTECs of wild type or Aire-knockout (KO) mice. We used computational algorithms as FASTQC, STAR and HTSEQ for sequence alignment and counting reads, DESEQ2 for the differential expression, 3USS for the alternative 3'UTRs and TAPAS for the alternative polyadenylation sites. We identified 152 differentially expressed mRNAs between these samples comprising those that encode PTAs as well as transcription regulators. In Aire KO mTECs, most of these mRNAs featured an increase in the length of their 3'UTRs originating additional miRNA binding sites and new miRNA controllers. Results from the in silico analysis were statistically significant and the predicted miRNA-mRNA interactions were thermodynamically stable. Even with no in vivo or in vitro experiments, they were adequate to show that lack of Aire in mTECs might favor the downregulation of PTA mRNAs and transcription regulators via miRNA control. This could unbalance the overall transcriptional activity in mTECs and thus the self-representation.
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Affiliation(s)
- Ernna H. Oliveira
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, Brazil
| | | | - Cesar A. Speck-Hernandez
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, Brazil
| | - Max Jordan Duarte
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, Brazil
| | - Geraldo A. Passos
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, Brazil
- Laboratory of Genetics and Molecular Biology, Department of Basic and Oral Biology, School of Dentistry of Ribeirão Preto, USP, Ribeirão Preto, Brazil
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27
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Guyon C, Jmari N, Padonou F, Li YC, Ucar O, Fujikado N, Coulpier F, Blanchet C, Root DE, Giraud M. Aire-dependent genes undergo Clp1-mediated 3'UTR shortening associated with higher transcript stability in the thymus. eLife 2020; 9:52985. [PMID: 32338592 PMCID: PMC7205469 DOI: 10.7554/elife.52985] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 04/24/2020] [Indexed: 12/23/2022] Open
Abstract
The ability of the immune system to avoid autoimmune disease relies on tolerization of thymocytes to self-antigens whose expression and presentation by thymic medullary epithelial cells (mTECs) is controlled predominantly by Aire at the transcriptional level and possibly regulated at other unrecognized levels. Aire-sensitive gene expression is influenced by several molecular factors, some of which belong to the 3'end processing complex, suggesting they might impact transcript stability and levels through an effect on 3'UTR shortening. We discovered that Aire-sensitive genes display a pronounced preference for short-3'UTR transcript isoforms in mTECs, a feature preceding Aire's expression and correlated with the preferential selection of proximal polyA sites by the 3'end processing complex. Through an RNAi screen and generation of a lentigenic mouse, we found that one factor, Clp1, promotes 3'UTR shortening associated with higher transcript stability and expression of Aire-sensitive genes, revealing a post-transcriptional level of control of Aire-activated expression in mTECs.
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Affiliation(s)
- Clotilde Guyon
- Institut Cochin, INSERM U1016, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Nada Jmari
- Institut Cochin, INSERM U1016, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Francine Padonou
- Institut Cochin, INSERM U1016, Université Paris Descartes, Sorbonne Paris Cité, Paris, France.,Université de Nantes, Inserm, Centre de Recherche en Transplantation et Immunologie, UMR 1064, ITUN, F-44000, Nantes, France
| | - Yen-Chin Li
- Institut Cochin, INSERM U1016, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Olga Ucar
- Division of Developmental Immunology, German Cancer Research Center, Heidelberg, Germany
| | - Noriyuki Fujikado
- Division of Immunology, Department of Microbiology and Immunobiology, Harvard Medical School, Boston, United States
| | - Fanny Coulpier
- Ecole Normale Supérieure, PSL Research University, CNRS, INSERM, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Plateforme Génomique, Paris, France
| | | | - David E Root
- The Broad Institute of MIT and Harvard, Cambridge, United States
| | - Matthieu Giraud
- Institut Cochin, INSERM U1016, Université Paris Descartes, Sorbonne Paris Cité, Paris, France.,Université de Nantes, Inserm, Centre de Recherche en Transplantation et Immunologie, UMR 1064, ITUN, F-44000, Nantes, France
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28
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Larouche JD, Trofimov A, Hesnard L, Ehx G, Zhao Q, Vincent K, Durette C, Gendron P, Laverdure JP, Bonneil É, Côté C, Lemieux S, Thibault P, Perreault C. Widespread and tissue-specific expression of endogenous retroelements in human somatic tissues. Genome Med 2020; 12:40. [PMID: 32345368 PMCID: PMC7189544 DOI: 10.1186/s13073-020-00740-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 04/13/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Endogenous retroelements (EREs) constitute about 42% of the human genome and have been implicated in common human diseases such as autoimmunity and cancer. The dominant paradigm holds that EREs are expressed in embryonic stem cells (ESCs) and germline cells but are repressed in differentiated somatic cells. Despite evidence that some EREs can be expressed at the RNA and protein levels in specific contexts, a system-level evaluation of their expression in human tissues is lacking. METHODS Using RNA sequencing data, we analyzed ERE expression in 32 human tissues and cell types, including medullary thymic epithelial cells (mTECs). A tissue specificity index was computed to identify tissue-restricted ERE families. We also analyzed the transcriptome of mTECs in wild-type and autoimmune regulator (AIRE)-deficient mice. Finally, we developed a proteogenomic workflow combining RNA sequencing and mass spectrometry (MS) in order to evaluate whether EREs might be translated and generate MHC I-associated peptides (MAP) in B-lymphoblastoid cell lines (B-LCL) from 16 individuals. RESULTS We report that all human tissues express EREs, but the breadth and magnitude of ERE expression are very heterogeneous from one tissue to another. ERE expression was particularly high in two MHC I-deficient tissues (ESCs and testis) and one MHC I-expressing tissue, mTECs. In mutant mice, we report that the exceptional expression of EREs in mTECs was AIRE-independent. MS analyses identified 103 non-redundant ERE-derived MAPs (ereMAPs) in B-LCLs. These ereMAPs preferentially derived from sense translation of intronic EREs. Notably, detailed analyses of their amino acid composition revealed that ERE-derived MAPs presented homology to viral MAPs. CONCLUSIONS This study shows that ERE expression in somatic tissues is more pervasive and heterogeneous than anticipated. The high and diversified expression of EREs in mTECs and their ability to generate MAPs suggest that EREs may play an important role in the establishment of self-tolerance. The viral-like properties of ERE-derived MAPs suggest that those not expressed in mTECs can be highly immunogenic.
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Affiliation(s)
- Jean-David Larouche
- Institute of Research in Immunology and Cancer, Université de Montréal, P.O. Box 6128, Downtown Station, Montréal, QC, H3C 3J7, Canada
- Department of Medicine, Université de Montréal, Montréal, QC, Canada
| | - Assya Trofimov
- Institute of Research in Immunology and Cancer, Université de Montréal, P.O. Box 6128, Downtown Station, Montréal, QC, H3C 3J7, Canada
- Department of Computer Science and Operations Research, Université de Montréal, Montréal, QC, Canada
| | - Leslie Hesnard
- Institute of Research in Immunology and Cancer, Université de Montréal, P.O. Box 6128, Downtown Station, Montréal, QC, H3C 3J7, Canada
- Department of Medicine, Université de Montréal, Montréal, QC, Canada
| | - Gregory Ehx
- Institute of Research in Immunology and Cancer, Université de Montréal, P.O. Box 6128, Downtown Station, Montréal, QC, H3C 3J7, Canada
- Department of Medicine, Université de Montréal, Montréal, QC, Canada
| | - Qingchuan Zhao
- Institute of Research in Immunology and Cancer, Université de Montréal, P.O. Box 6128, Downtown Station, Montréal, QC, H3C 3J7, Canada
- Department of Medicine, Université de Montréal, Montréal, QC, Canada
| | - Krystel Vincent
- Institute of Research in Immunology and Cancer, Université de Montréal, P.O. Box 6128, Downtown Station, Montréal, QC, H3C 3J7, Canada
- Department of Medicine, Université de Montréal, Montréal, QC, Canada
| | - Chantal Durette
- Institute of Research in Immunology and Cancer, Université de Montréal, P.O. Box 6128, Downtown Station, Montréal, QC, H3C 3J7, Canada
| | - Patrick Gendron
- Institute of Research in Immunology and Cancer, Université de Montréal, P.O. Box 6128, Downtown Station, Montréal, QC, H3C 3J7, Canada
| | - Jean-Philippe Laverdure
- Institute of Research in Immunology and Cancer, Université de Montréal, P.O. Box 6128, Downtown Station, Montréal, QC, H3C 3J7, Canada
| | - Éric Bonneil
- Institute of Research in Immunology and Cancer, Université de Montréal, P.O. Box 6128, Downtown Station, Montréal, QC, H3C 3J7, Canada
| | - Caroline Côté
- Institute of Research in Immunology and Cancer, Université de Montréal, P.O. Box 6128, Downtown Station, Montréal, QC, H3C 3J7, Canada
| | - Sébastien Lemieux
- Institute of Research in Immunology and Cancer, Université de Montréal, P.O. Box 6128, Downtown Station, Montréal, QC, H3C 3J7, Canada
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, QC, Canada
| | - Pierre Thibault
- Institute of Research in Immunology and Cancer, Université de Montréal, P.O. Box 6128, Downtown Station, Montréal, QC, H3C 3J7, Canada.
- Department of Chemistry, Université de Montréal, Montréal, QC, Canada.
| | - Claude Perreault
- Institute of Research in Immunology and Cancer, Université de Montréal, P.O. Box 6128, Downtown Station, Montréal, QC, H3C 3J7, Canada.
- Department of Medicine, Université de Montréal, Montréal, QC, Canada.
- Division of Hematology-Oncology, Hôpital Maisonneuve-Rosemont, Montréal, QC, Canada.
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29
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Vongpipatana T, Nakahama T, Shibuya T, Kato Y, Kawahara Y. ADAR1 Regulates Early T Cell Development via MDA5-Dependent and -Independent Pathways. THE JOURNAL OF IMMUNOLOGY 2020; 204:2156-2168. [DOI: 10.4049/jimmunol.1900929] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 02/11/2020] [Indexed: 11/19/2022]
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30
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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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31
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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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32
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Abstract
Modifications of RNA affect its function and stability. RNA editing is unique among these modifications because it not only alters the cellular fate of RNA molecules but also alters their sequence relative to the genome. The most common type of RNA editing is A-to-I editing by double-stranded RNA-specific adenosine deaminase (ADAR) enzymes. Recent transcriptomic studies have identified a number of 'recoding' sites at which A-to-I editing results in non-synonymous substitutions in protein-coding sequences. Many of these recoding sites are conserved within (but not usually across) lineages, are under positive selection and have functional and evolutionary importance. However, systematic mapping of the editome across the animal kingdom has revealed that most A-to-I editing sites are located within mobile elements in non-coding parts of the genome. Editing of these non-coding sites is thought to have a critical role in protecting against activation of innate immunity by self-transcripts. Both recoding and non-coding events have implications for genome evolution and, when deregulated, may lead to disease. Finally, ADARs are now being adapted for RNA engineering purposes.
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Ma CP, Liu H, Yi-Feng Chang I, Wang WC, Chen YT, Wu SM, Chen HW, Kuo YP, Shih CT, Li CY, Tan BCM. ADAR1 promotes robust hypoxia signaling via distinct regulation of multiple HIF-1α-inhibiting factors. EMBO Rep 2019; 20:e47107. [PMID: 30948460 PMCID: PMC6500999 DOI: 10.15252/embr.201847107] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 03/12/2019] [Accepted: 03/14/2019] [Indexed: 12/15/2022] Open
Abstract
Adenosine deaminase acting on RNA (ADAR)-catalyzed adenosine-to-inosine RNA editing is potentially dysregulated in neoplastic progression. However, how this transcriptome recoding process is functionally correlated with tumorigenesis remains largely elusive. Our analyses of RNA editome datasets identify hypoxia-related genes as A-to-I editing targets. In particular, two negative regulators of HIF-1A-the natural antisense transcript HIF1A-AS2 and the ubiquitin ligase scaffold LIMD1-are directly but differentially modulated by ADAR1. We show that HIF1A-AS2 antagonizes the expression of HIF-1A in the immediate-early phase of hypoxic challenge, likely through a convergent transcription competition in cis ADAR1 in turn suppresses transcriptional progression of the antisense gene. In contrast, ADAR1 affects LIMD1 expression post-transcriptionally, by interfering with the cytoplasmic translocation of LIMD1 mRNA and thus protein translation. This multi-tier regulation coordinated by ADAR1 promotes robust and timely accumulation of HIF-1α upon oxygen depletion and reinforces target gene induction and downstream angiogenesis. Our results pinpoint ADAR1-HIF-1α axis as a hitherto unrecognized key regulator in hypoxia.
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Affiliation(s)
- Chung-Pei Ma
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Hsuan Liu
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Molecular Medicine Research Center, Chang Gung University, Taoyuan, Taiwan
- Department of Cell and Molecular Biology, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Division of Colon and Rectal Surgery, Lin-Kou Medical Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Ian Yi-Feng Chang
- Molecular Medicine Research Center, Chang Gung University, Taoyuan, Taiwan
| | - Wan-Cheng Wang
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Yi-Tung Chen
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Shao-Min Wu
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Hui-Wen Chen
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Yu-Ping Kuo
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chieh-Tien Shih
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chuan-Yun Li
- Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Bertrand Chin-Ming Tan
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Department of Neurosurgery, Lin-Kou Medical Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- Research Center for Emerging Viral Infections, Chang Gung University, Taoyuan, Taiwan
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Ossart J, Moreau A, Autrusseau E, Ménoret S, Martin JC, Besnard M, Ouisse LH, Tesson L, Flippe L, Kisand K, Peterson P, Hubert FX, Anegon I, Josien R, Guillonneau C. Breakdown of Immune Tolerance in AIRE-Deficient Rats Induces a Severe Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy-like Autoimmune Disease. THE JOURNAL OF IMMUNOLOGY 2018; 201:874-887. [PMID: 29959280 DOI: 10.4049/jimmunol.1701318] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 06/02/2018] [Indexed: 12/31/2022]
Abstract
Autoimmune regulator (AIRE) deficiency in humans induces a life-threatening generalized autoimmune disease called autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), and no curative treatments are available. Several models of AIRE-deficient mice have been generated, and although they have been useful in understanding the role of AIRE in central tolerance, they do not reproduce accurately the APECED symptoms, and thus there is still a need for an animal model displaying APECED-like disease. We assessed, in this study, the potential of the rat as an accurate model for APECED. In this study, we demonstrate that in rat, AIRE is expressed by MHC class II (MCH-II)+ and MHC-II- medullary thymic epithelial cells in thymus and by CD4int conventional dendritic cells in periphery. To our knowledge, we generated the first AIRE-deficient rat model using zinc-finger nucleases and demonstrated that they display several of the key symptoms of APECED disease, including alopecia, skin depigmentation, and nail dystrophy, independently of the genetic background. We observed severe autoimmune lesions in a large spectrum of organs, in particular in the pancreas, and identified several autoantibodies in organs and cytokines such as type I IFNs and IL-17 at levels similar to APECED. Finally, we demonstrated a biased Ab response to IgG1, IgM, and IgA isotypes. Altogether, our data demonstrate that AIRE-deficient rat is a relevant APECED animal model, opening new opportunity to test curative therapeutic treatments.
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Affiliation(s)
- Jason Ossart
- Centre de Recherche en Transplantation et Immunologie UMR 1064, INSERM Université de Nantes, 44093 Nantes, France.,Institut de Transplantation Urologie Néphrologie, CHU Nantes, 44093 Nantes, France
| | - Anne Moreau
- Anatomie et Cytologie Pathologiques, CHU Nantes, 44093 Nantes, France
| | - Elodie Autrusseau
- Centre de Recherche en Transplantation et Immunologie UMR 1064, INSERM Université de Nantes, 44093 Nantes, France.,Institut de Transplantation Urologie Néphrologie, CHU Nantes, 44093 Nantes, France
| | - Séverine Ménoret
- Centre de Recherche en Transplantation et Immunologie UMR 1064, INSERM Université de Nantes, 44093 Nantes, France.,Institut de Transplantation Urologie Néphrologie, CHU Nantes, 44093 Nantes, France.,Transgenesis Rat Immunophenomic Platform, INSERM 1064 and SFR Francois Bonamy, CNRS UMS3556, 44093 Nantes, France
| | - Jérôme C Martin
- Centre de Recherche en Transplantation et Immunologie UMR 1064, INSERM Université de Nantes, 44093 Nantes, France.,Institut de Transplantation Urologie Néphrologie, CHU Nantes, 44093 Nantes, France
| | - Marine Besnard
- Centre de Recherche en Transplantation et Immunologie UMR 1064, INSERM Université de Nantes, 44093 Nantes, France.,Institut de Transplantation Urologie Néphrologie, CHU Nantes, 44093 Nantes, France
| | - Laure-Hélène Ouisse
- Centre de Recherche en Transplantation et Immunologie UMR 1064, INSERM Université de Nantes, 44093 Nantes, France.,Institut de Transplantation Urologie Néphrologie, CHU Nantes, 44093 Nantes, France.,Transgenesis Rat Immunophenomic Platform, INSERM 1064 and SFR Francois Bonamy, CNRS UMS3556, 44093 Nantes, France
| | - Laurent Tesson
- Centre de Recherche en Transplantation et Immunologie UMR 1064, INSERM Université de Nantes, 44093 Nantes, France.,Institut de Transplantation Urologie Néphrologie, CHU Nantes, 44093 Nantes, France.,Transgenesis Rat Immunophenomic Platform, INSERM 1064 and SFR Francois Bonamy, CNRS UMS3556, 44093 Nantes, France
| | - Léa Flippe
- Centre de Recherche en Transplantation et Immunologie UMR 1064, INSERM Université de Nantes, 44093 Nantes, France.,Institut de Transplantation Urologie Néphrologie, CHU Nantes, 44093 Nantes, France
| | - Kai Kisand
- Molecular Pathology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu 50411, Estonia; and
| | - Pärt Peterson
- Molecular Pathology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu 50411, Estonia; and
| | - François-Xavier Hubert
- Centre de Recherche en Transplantation et Immunologie UMR 1064, INSERM Université de Nantes, 44093 Nantes, France.,Institut de Transplantation Urologie Néphrologie, CHU Nantes, 44093 Nantes, France
| | - Ignacio Anegon
- Centre de Recherche en Transplantation et Immunologie UMR 1064, INSERM Université de Nantes, 44093 Nantes, France.,Institut de Transplantation Urologie Néphrologie, CHU Nantes, 44093 Nantes, France.,Transgenesis Rat Immunophenomic Platform, INSERM 1064 and SFR Francois Bonamy, CNRS UMS3556, 44093 Nantes, France
| | - Régis Josien
- Centre de Recherche en Transplantation et Immunologie UMR 1064, INSERM Université de Nantes, 44093 Nantes, France.,Institut de Transplantation Urologie Néphrologie, CHU Nantes, 44093 Nantes, France.,Laboratoire d'Immunologie, CHU Nantes, 44093 Nantes, France
| | - Carole Guillonneau
- Centre de Recherche en Transplantation et Immunologie UMR 1064, INSERM Université de Nantes, 44093 Nantes, France; .,Institut de Transplantation Urologie Néphrologie, CHU Nantes, 44093 Nantes, France
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Speck-Hernandez CA, Assis AF, Felicio RF, Cotrim-Sousa L, Pezzi N, Lopes GS, Bombonato-Prado KF, Giuliatti S, Passos GA. Aire Disruption Influences the Medullary Thymic Epithelial Cell Transcriptome and Interaction With Thymocytes. Front Immunol 2018; 9:964. [PMID: 29867946 PMCID: PMC5949327 DOI: 10.3389/fimmu.2018.00964] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Accepted: 04/18/2018] [Indexed: 11/13/2022] Open
Abstract
The function of medullary thymic epithelial cells (mTECs) is associated with thymocyte adhesion, which is crucial for the negative selection of autoreactive thymocytes in the thymus. This process represents the root of central tolerance of self-components and prevents the onset of autoimmune diseases. Since thymic epithelia correspond to an important target of donor T cells during the onset of chronic graft-vs-host-disease, mTEC-thymocyte adhesion may have implications for alloimmunity. The Aire and Fezf2 genes function as transcriptome controllers in mTECs. The central question of this study is whether there is a mutual relationship between mTEC-thymocyte adhesion and the control of the mTEC transcriptome and whether Aire is involved in this process. Here, we show that in vitro mTEC-thymocyte adhesion causes transcriptome changes in mTECs and upregulates the transcriptional expression of Aire and Fezf2, as well as cell adhesion-related genes such as Cd80 or Tcf7, among others. Crispr-Cas9-mediated Aire gene disruption demonstrated that this gene plays a role in the process of mTEC-thymocyte adhesion. Consistent with the nuclear localization signal (NLS) encoded by Aire exon 3, which was targeted, we demonstrate that Aire KO-/- mTECs impair AIRE protein localization in the nucleus. Consequently, the loss of function of Aire reduced the ability of these cells to adhere to thymocytes. Their transcriptomes differed from their wild-type Aire+/+ counterparts, even during thymocyte adhesion. A set of mRNA isoforms that encode proteins involved in cell adhesion were also modulated during this process. This demonstrates that both thymocyte interactions and Aire influence transcriptome profiling of mTEC cells.
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Affiliation(s)
- Cesar A. Speck-Hernandez
- Graduate Programme in Basic and Applied Immunology, Universidade de São Paulo, São Paulo, Brazil
| | - Amanda F. Assis
- Molecular Immunogenetics Group, Genetics, Ribeirão Preto Medical School, Universidade de São Paulo, São Paulo, Brazil
| | - Rafaela F. Felicio
- Graduate Programme in Basic and Applied Immunology, Universidade de São Paulo, São Paulo, Brazil
| | - Larissa Cotrim-Sousa
- Molecular Immunogenetics Group, Genetics, Ribeirão Preto Medical School, Universidade de São Paulo, São Paulo, Brazil
| | - Nicole Pezzi
- Graduate Programme in Basic and Applied Immunology, Universidade de São Paulo, São Paulo, Brazil
| | - Gabriel S. Lopes
- Graduate Programme in Cellular and Molecular Biology, Ribeirão Preto Medical School, Universidade de São Paulo, São Paulo, Brazil
| | - Karina F. Bombonato-Prado
- Morphology, Physiology and Basic Pathology, School of Dentistry of Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - Silvana Giuliatti
- Genetics, Bioinformatics Group, Ribeirão Preto Medical School, Universidade de São Paulo, São Paulo, Brazil
| | - Geraldo A. Passos
- Molecular Immunogenetics Group, Genetics, Ribeirão Preto Medical School, Universidade de São Paulo, São Paulo, Brazil
- Morphology, Physiology and Basic Pathology, School of Dentistry of Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
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36
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Schaub A, Glasmacher E. Splicing in immune cells-mechanistic insights and emerging topics. Int Immunol 2018; 29:173-181. [PMID: 28498981 PMCID: PMC5890895 DOI: 10.1093/intimm/dxx026] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Accepted: 04/27/2017] [Indexed: 11/26/2022] Open
Abstract
Differential splicing of mRNAs not only enables regulation of gene expression levels, but also ensures a high degree of gene-product diversity. The extent to which splicing of mRNAs is utilized as a mechanism in immune cells has become evident within the last few years. Still, only a few of these mechanisms have been well studied. In this review, we discuss some of the best-understood mechanisms, for instance the differential splicing of CD45 in T cells, as well as immunoglobulin genes in B cells. Beyond that we provide general mechanistic insights on how, when and where this process takes place and discuss the current knowledge regarding these topics in immune cells. We also highlight some of the reported links to immune-related diseases, genome-wide sequencing studies that revealed thousands of differentially spliced transcripts, as well as splicing studies on immune cells that remain mechanistically not fully understood. We thereby display potential emerging topics for future studies centered on splicing mechanisms in immune cells.
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Affiliation(s)
- Annalisa Schaub
- Institute for Diabetes and Obesity, Helmholtz Zentrum München, German Center for Diabetes Research (DZD), 85764 München-Neuherberg, Germany
| | - Elke Glasmacher
- Institute for Diabetes and Obesity, Helmholtz Zentrum München, German Center for Diabetes Research (DZD), 85764 München-Neuherberg, Germany
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37
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Roth SH, Danan-Gotthold M, Ben-Izhak M, Rechavi G, Cohen CJ, Louzoun Y, Levanon EY. Increased RNA Editing May Provide a Source for Autoantigens in Systemic Lupus Erythematosus. Cell Rep 2018; 23:50-57. [PMID: 29617672 PMCID: PMC5905401 DOI: 10.1016/j.celrep.2018.03.036] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 11/21/2017] [Accepted: 03/09/2018] [Indexed: 12/12/2022] Open
Abstract
RNA-editing mechanisms, which induce nucleotide substitution in the RNA, increase transcript and protein diversities. Editing dysregulation has been shown to lead to grave outcomes, and transcriptome-wide aberrant RNA editing has been found in tumors. However, little is known about the involvement of editing in other diseases. Systemic lupus erythematosus (SLE) is a multisystemic autoimmune disease characterized by a loss of tolerance for autoantigens from various tissues and the production of multiple autoantibodies. Here, we show that blood samples from individuals with SLE have abnormally high levels of RNA editing, some of which affect proteins and potentially generate novel autoantigens. We suggest that elevated RNA editing, either by ADARs or APOBECs, may be involved in the pathophysiology of SLE, as well as in other autoimmune diseases, by generating or increasing the autoantigen load, a key requisite for the progression of autoimmunity.
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Affiliation(s)
- Shalom Hillel Roth
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 5290002, Israel
| | - Miri Danan-Gotthold
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 5290002, Israel
| | - Meirav Ben-Izhak
- Department of Mathematics, Bar-Ilan University, Ramat Gan 5290002, Israel; The Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan 5290002, Israel
| | - Gideon Rechavi
- Cancer Research Center and the Wohl Institute for Translational Medicine, Chaim Sheba Medical Center, Tel Hashomer 52621, Israel
| | - Cyrille J Cohen
- Laboratory of Tumor Immunology and Immunotherapy, The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 5290002, Israel
| | - Yoram Louzoun
- Department of Mathematics, Bar-Ilan University, Ramat Gan 5290002, Israel; The Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan 5290002, Israel
| | - Erez Y Levanon
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 5290002, Israel
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38
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Abstract
The immune system is remarkably responsive to a myriad of invading microorganisms and provides continuous surveillance against tissue damage and developing tumor cells. To achieve these diverse functions, multiple soluble and cellular components must react in an orchestrated cascade of events to control the specificity, magnitude and persistence of the immune response. Numerous catabolic and anabolic processes are involved in this process, and prominent roles for l-arginine and l-glutamine catabolism have been described, as these amino acids serve as precursors of nitric oxide, creatine, agmatine, tricarboxylic acid cycle intermediates, nucleotides and other amino acids, as well as for ornithine, which is used to synthesize putrescine and the polyamines spermidine and spermine. Polyamines have several purported roles and high levels of polyamines are manifest in tumor cells as well in autoreactive B- and T-cells in autoimmune diseases. In the tumor microenvironment, l-arginine catabolism by both tumor cells and suppressive myeloid cells is known to dampen cytotoxic T-cell functions suggesting there might be links between polyamines and T-cell suppression. Here, we review studies suggesting roles of polyamines in normal immune cell function and highlight their connections to autoimmunity and anti-tumor immune cell function.
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Affiliation(s)
- Rebecca S Hesterberg
- University of South Florida Cancer Biology Graduate Program, University of South Florida, 4202 East Fowler Ave, Tampa, FL 33620, USA.
- Department Immunology, PharmD, Moffitt Cancer Center & Research Institute, 12902 Magnolia Drive, 23033 SRB, Tampa, FL 33612, USA.
| | - John L Cleveland
- Department of Tumor Biology, Moffitt Cancer Center & Research Institute, 12902 Magnolia Drive, Tampa, FL 33612, USA.
| | - Pearlie K Epling-Burnette
- Department Immunology, PharmD, Moffitt Cancer Center & Research Institute, 12902 Magnolia Drive, 23033 SRB, Tampa, FL 33612, USA.
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39
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Dobeš J, Edenhofer F, Vobořil M, Brabec T, Dobešová M, Čepková A, Klein L, Rajewsky K, Filipp D. A novel conditional Aire allele enables cell-specific ablation of the immune tolerance regulator Aire. Eur J Immunol 2018; 48:546-548. [PMID: 29193031 DOI: 10.1002/eji.201747267] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Revised: 11/05/2017] [Accepted: 11/23/2017] [Indexed: 11/12/2022]
Abstract
Medullary thymic epithelial cell (mTEC)-restricted expression of autoimmune regulator (Aire) is essential for establishment of immune tolerance. Recently, Aire was also shown to be expressed in cells of hematopietic and reproductive lineages. Thus, the generation of Airefl/fl mouse strain enables the investigation of the cell-specific function of Aire.
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Affiliation(s)
- Jan Dobeš
- Laboratory of Immunobiology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Frank Edenhofer
- Institute of Genetics, University of Cologne, Cologne, Germany
| | - Matouš Vobořil
- Laboratory of Immunobiology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
- Department of Cell biology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Tomáš Brabec
- 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
| | - Adéla Čepková
- Laboratory of Immunobiology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Ludger Klein
- Laboratory of Thymusfuction, Institute for Immunology, Ludwig-Maxmilians-Universität München, Munich, Germany
| | - Klaus Rajewsky
- Institute of Genetics, University of Cologne, Cologne, Germany
| | - Dominik Filipp
- Laboratory of Immunobiology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
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40
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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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41
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Enteric α-defensins on the verge of intestinal immune tolerance and inflammation. Semin Cell Dev Biol 2018; 88:138-146. [PMID: 29355606 DOI: 10.1016/j.semcdb.2018.01.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 01/12/2018] [Indexed: 12/18/2022]
Abstract
The gut is the biggest immune organ in the body that encloses commensal microbiota which aids in food digestion. Paneth cells, positioned at the frontline of host-microbiota interphase, can modulate the composition of microbiota. Paneth cells achieve this via the delivery of microbicidal substances, among which enteric α-defensins play the primary role. If microbiota is dysregulated, it can impact the function of the local mucosal immune system. Importantly, this system is also exposed to an enormous number of antigens which are derived from the gut-resident microbiota and processed food, and may potentially trigger undesirable local inflammatory responses. To understand the intricate regulations and liaisons between Paneth cells, microbiota and the immune system in this intestinal-specific setting, one must consider their mode of interaction in a wider context of regulatory processes which impose immune tolerance not only to self, but also to microbiota and food-derived antigens. These include, but are not limited to, tolerogenic mechanisms of central tolerance in the thymus and peripheral tolerance in the secondary lymphoid organs, and the intestine itself. Defects in these processes can compromise homeostasis in the intestinal mucosal immunity. In this review, which is focused on tolerance to intestinal antigens and its relevance for the pathogenesis of gut immune diseases, we provide an outline of such multilayered immune control mechanisms and highlight functional links that underpin their cooperative nature.
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42
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Passos GA, Speck‐Hernandez CA, Assis AF, Mendes‐da‐Cruz DA. Update on Aire and thymic negative selection. Immunology 2018; 153:10-20. [PMID: 28871661 PMCID: PMC5721245 DOI: 10.1111/imm.12831] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 08/24/2017] [Accepted: 08/31/2017] [Indexed: 12/17/2022] Open
Abstract
Twenty years ago, the autoimmune regulator (Aire) gene was associated with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy, and was cloned and sequenced. Its importance goes beyond its abstract link with human autoimmune disease. Aire identification opened new perspectives to better understand the molecular basis of central tolerance and self-non-self distinction, the main properties of the immune system. Since 1997, a growing number of immunologists and molecular geneticists have made important discoveries about the function of Aire, which is essentially a pleiotropic gene. Aire is one of the functional markers in medullary thymic epithelial cells (mTECs), controlling their differentiation and expression of peripheral tissue antigens (PTAs), mTEC-thymocyte adhesion and the expression of microRNAs, among other functions. With Aire, the immunological tolerance became even more apparent from the molecular genetics point of view. Currently, mTECs represent the most unusual cells because they express almost the entire functional genome but still maintain their identity. Due to the enormous diversity of PTAs, this uncommon gene expression pattern was termed promiscuous gene expression, the interpretation of which is essentially immunological - i.e. it is related to self-representation in the thymus. Therefore, this knowledge is strongly linked to the negative selection of autoreactive thymocytes. In this update, we focus on the most relevant results of Aire as a transcriptional and post-transcriptional controller of PTAs in mTECs, its mechanism of action, and its influence on the negative selection of autoreactive thymocytes as the bases of the induction of central tolerance and prevention of autoimmune diseases.
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Affiliation(s)
- Geraldo A. Passos
- Molecular Immunogenetics GroupDepartment of GeneticsRibeirão Preto Medical SchoolUniversity of São PauloRibeirão PretoSPBrazil
- Discipline of Genetics and Molecular BiologyDepartment of Morphology, Physiology and Basic PathologySchool of Dentistry of Ribeirão PretoUniversity of São PauloRibeirão PretoSPBrazil
| | - Cesar A. Speck‐Hernandez
- Graduate Programme in Basic and Applied ImmunologyRibeirão Preto Medical SchoolUniversity of São PauloRibeirão PretoSPBrazil
| | - Amanda F. Assis
- Molecular Immunogenetics GroupDepartment of GeneticsRibeirão Preto Medical SchoolUniversity of São PauloRibeirão PretoSPBrazil
| | - Daniella A. Mendes‐da‐Cruz
- Laboratory on Thymus ResearchOswaldo Cruz InstituteOswaldo Cruz FoundationRio de JaneiroRJBrazil
- National Institute of Science and Technology on NeuroimmunomodulationRio de JaneiroRJBrazil
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43
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Abstract
Autoimmune diseases are classified into about 80 different types based on their specificity related to system, organ and/or tissue. About 5% of the western population is affected by this anomaly, but its worldwide incidence is unknown. Autoimmune diseases are heterogeneous in nature and clinical manifestations range from benign disorders to life-threatening conditions. Autoimmunity strikes at any stage of life, but age and/or gender also play role in onset of some of these anomalies. The autoimmune pathogenesis is initiated by the origination of autoantigens, which leads to the development of autoantibodies followed by auto-immunogenicity and the ultimate onset of autoimmunity. There is a lack of suitable therapies to treat autoimmune diseases, because mechanisms involved in the onset of these anomalies were poorly understood. Present therapies are limited to symptomatic treatment and come with severe side effects. Here, I described the molecular mechanisms and cellular events involved in the initiation of autoimmunity and proposed better strategies to modulate such molecular and cellular anomalies, which will help in preventing and/or controlling autoimmune pathogenesis and ultimately aid in enhancing the quality of life.
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Affiliation(s)
- Dama Laxminarayana
- Editor in Chief, Clinical Medicine Insights: Pathology; Sathya Krishna Genomics LLC, Winston-Salem, NC, USA
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Takahama Y, Ohigashi I, Baik S, Anderson G. Generation of diversity in thymic epithelial cells. Nat Rev Immunol 2017; 17:295-305. [PMID: 28317923 DOI: 10.1038/nri.2017.12] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In the thymus, diverse populations of thymic epithelial cells (TECs), including cortical and medullary TECs and their subpopulations, have distinct roles in coordinating the development and repertoire selection of functionally competent and self-tolerant T cells. Here, we review the expanding diversity in TEC subpopulations in relation to their functions in T cell development and selection as well as their origins and development.
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Affiliation(s)
- Yousuke Takahama
- Division of Experimental Immunology, Institute of Advanced Medical Sciences, University of Tokushima, Tokushima 770-8503, Japan
| | - Izumi Ohigashi
- Division of Experimental Immunology, Institute of Advanced Medical Sciences, University of Tokushima, Tokushima 770-8503, Japan
| | - Song Baik
- Institute for Immunology and Immunotherapy, Medical School, University of Birmingham, Birmingham B15 2TT, UK
| | - Graham Anderson
- Institute for Immunology and Immunotherapy, Medical School, University of Birmingham, Birmingham B15 2TT, UK
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Abstract
Intrathymic T cell development is a complex process that depends upon continuous guidance from thymus stromal cell microenvironments. The thymic epithelium within the thymic stroma comprises highly specialized cells with a high degree of anatomic, phenotypic, and functional heterogeneity. These properties are collectively required to bias thymocyte development toward production of self-tolerant and functionally competent T cells. The importance of thymic epithelial cells (TECs) is evidenced by clear links between their dysfunction and multiple diseases where autoimmunity and immunodeficiency are major components. Consequently, TECs are an attractive target for cell therapies to restore effective immune system function. The pathways and molecular regulators that control TEC development are becoming clearer, as are their influences on particular stages of T cell development. Here, we review both historical and the most recent advances in our understanding of the cellular and molecular mechanisms controlling TEC development, function, dysfunction, and regeneration.
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Affiliation(s)
- Jakub Abramson
- Department of Immunology, Weizmann Institute of Science, Rehovot 76100, Israel;
| | - Graham Anderson
- MRC Centre for Immune Regulation, Institute for Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, United Kingdom;
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Gallego-Paez LM, Bordone MC, Leote AC, Saraiva-Agostinho N, Ascensão-Ferreira M, Barbosa-Morais NL. Alternative splicing: the pledge, the turn, and the prestige : The key role of alternative splicing in human biological systems. Hum Genet 2017; 136:1015-1042. [PMID: 28374191 PMCID: PMC5602094 DOI: 10.1007/s00439-017-1790-y] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 03/25/2017] [Indexed: 02/06/2023]
Abstract
Alternative pre-mRNA splicing is a tightly controlled process conducted by the spliceosome, with the assistance of several regulators, resulting in the expression of different transcript isoforms from the same gene and increasing both transcriptome and proteome complexity. The differences between alternative isoforms may be subtle but enough to change the function or localization of the translated proteins. A fine control of the isoform balance is, therefore, needed throughout developmental stages and adult tissues or physiological conditions and it does not come as a surprise that several diseases are caused by its deregulation. In this review, we aim to bring the splicing machinery on stage and raise the curtain on its mechanisms and regulation throughout several systems and tissues of the human body, from neurodevelopment to the interactions with the human microbiome. We discuss, on one hand, the essential role of alternative splicing in assuring tissue function, diversity, and swiftness of response in these systems or tissues, and on the other hand, what goes wrong when its regulatory mechanisms fail. We also focus on the possibilities that splicing modulation therapies open for the future of personalized medicine, along with the leading techniques in this field. The final act of the spliceosome, however, is yet to be fully revealed, as more knowledge is needed regarding the complex regulatory network that coordinates alternative splicing and how its dysfunction leads to disease.
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Affiliation(s)
- L M Gallego-Paez
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - M C Bordone
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - A C Leote
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - N Saraiva-Agostinho
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - M Ascensão-Ferreira
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - N L Barbosa-Morais
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.
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