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Qi Y, Zhang R, Lu Y, Zou X, Yang W. Aire and Fezf2, two regulators in medullary thymic epithelial cells, control autoimmune diseases by regulating TSAs: Partner or complementer? Front Immunol 2022; 13:948259. [PMID: 36110862 PMCID: PMC9468217 DOI: 10.3389/fimmu.2022.948259] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 08/08/2022] [Indexed: 11/13/2022] Open
Abstract
The expression of tissue-specific antigens (TSAs) in medullary thymic epithelial cells (mTECs) is believed to be responsible for the elimination of autoreactive T cells, a critical process in the maintenance of central immune tolerance. The transcription factor autoimmune regulator (Aire) and FEZ family zinc finger 2(Fezf2) play an essential role in driving the expression of TSAs in mTECs, while their deficiency in humans and mice causes a range of autoimmune manifestations, such as type 1 diabetes, Sjögren’s syndrome and rheumatoid arthritis. However, because of their regulatory mechanisms, the expression profile of TSAs and their relationship with special autoimmune diseases are still in dispute. In this review, we compare the roles of Aire and Fezf2 in regulating TSAs, with an emphasis on their molecular mechanisms in autoimmune diseases, which provides the foundation for devising improved diagnostic and therapeutic approaches for patients.
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Affiliation(s)
| | | | | | | | - Wei Yang
- *Correspondence: Wei Yang, ; Xueyang Zou,
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2
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Bigley TM, Yang L, Kang LI, Saenz JB, Victorino F, Yokoyama WM. Disruption of thymic central tolerance by infection with murine roseolovirus induces autoimmune gastritis. J Exp Med 2022; 219:213039. [PMID: 35226043 PMCID: PMC8932538 DOI: 10.1084/jem.20211403] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 11/29/2021] [Accepted: 01/24/2022] [Indexed: 12/12/2022] Open
Abstract
Infections with herpesviruses, including human roseoloviruses, have been proposed to cause autoimmune disease, but defining a causal relationship and mechanism has been difficult due to the ubiquitous nature of infection and development of autoimmunity long after acute infection. Murine roseolovirus (MRV) is highly related to human roseoloviruses. Herein we show that neonatal MRV infection induced autoimmune gastritis (AIG) in adult mice in the absence of ongoing infection. MRV-induced AIG was dependent on replication during the neonatal period and was CD4+ T cell and IL-17 dependent. Moreover, neonatal MRV infection was associated with development of a wide array of autoantibodies in adult mice. Finally, neonatal MRV infection reduced medullary thymic epithelial cell numbers, thymic dendritic cell numbers, and thymic expression of AIRE and tissue-restricted antigens, in addition to increasing thymocyte apoptosis at the stage of negative selection. These findings strongly suggest that infection with a roseolovirus early in life results in disruption of central tolerance and development of autoimmune disease.
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Affiliation(s)
- Tarin M. Bigley
- Department of Pediatrics, Division of Rheumatology, Washington University School of Medicine, St. Louis, MO
| | - Liping Yang
- Department of Medicine, Division of Rheumatology, Washington University School of Medicine, St. Louis, MO
| | - Liang-I Kang
- Department of Pathology and Immunology, Division of Anatomic and Molecular Pathology, Washington University School of Medicine, St. Louis, MO
| | - Jose B. Saenz
- Department of Medicine, Division of Gastroenterology, Washington University School of Medicine, St. Louis, MO
| | - Francisco Victorino
- Department of Medicine, Division of Rheumatology, Washington University School of Medicine, St. Louis, MO
| | - Wayne M. Yokoyama
- Department of Medicine, Division of Rheumatology, Washington University School of Medicine, St. Louis, MO
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Rajabi F, Drake LA, Senna MM, Rezaei N. Alopecia areata: a review of disease pathogenesis. Br J Dermatol 2018; 179:1033-1048. [PMID: 29791718 DOI: 10.1111/bjd.16808] [Citation(s) in RCA: 153] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/16/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND Alopecia areata is a disorder that results in nonscarring hair loss. The psychological impact can be significant, leading to feelings of depression and social isolation. Objectives In this article, we seek to review the pathophysiological mechanisms proposed in recent years in a narrative fashion. METHODS We searched MEDLINE and Scopus for articles related to alopecia areata, with a particular emphasis on its pathogenesis. RESULTS The main theory of alopecia areata pathogenesis is that it is an autoimmune phenomenon resulting from a disruption in hair follicle immune privilege. What causes this breakdown is an issue of debate. Some believe that a stressed hair follicle environment triggers antigen presentation, while others blame a dysregulation in the central immune system entangling the follicles. Evidence for the latter theory is provided by animal studies, as well investigations around the AIRE gene. Different immune-cell lines including plasmacytoid dendritic cells, natural killer cells and T cells, along with key molecules such as interferon-γ, interleukin-15, MICA and NKG2D, have been identified as contributing to the autoimmune process. CONCLUSIONS Alopecia areata remains incurable, although it has been studied for years. Available treatment options at best are beneficial for milder cases, and the rate of relapse is high. Understanding the exact mechanisms of hair loss in alopecia areata is therefore of utmost importance to help identify potential therapeutic targets.
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Affiliation(s)
- F Rajabi
- Department of Dermatology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Network of Immunity in Infection, Malignancy and Autoimmunity (NIIMA), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - L A Drake
- Massachusetts General Hospital, Harvard Medical School, MA, U.S.A
| | - M M Senna
- Massachusetts General Hospital, Harvard Medical School, MA, U.S.A
| | - N Rezaei
- Research Center for Immunodeficiencies, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
- Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
- Network of Immunity in Infection, Malignancy and Autoimmunity (NIIMA), Universal Scientific Education and Research Network (USERN), Sheffield, U.K
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Lovewell TRJ, McDonagh AJG, Messenger AG, Azzouz M, Tazi-Ahnini R. Meta-Analysis of Autoimmune Regulator-Regulated Genes in Human and Murine Models: A Novel Human Model Provides Insights on the Role of Autoimmune Regulator in Regulating STAT1 and STAT1-Regulated Genes. Front Immunol 2018; 9:1380. [PMID: 30002654 PMCID: PMC6031710 DOI: 10.3389/fimmu.2018.01380] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 06/04/2018] [Indexed: 12/14/2022] Open
Abstract
Autoimmune regulator (AIRE) regulates promiscuous expression of tissue-restricted antigens in medullary epithelial cells (mTEC) of the thymus. To understand the diverse effects of AIRE, it is crucial to elucidate the molecular mechanisms underlying the process of AIRE-regulated gene expression. In this study, we generated a recombinant AIRE expression variant of the TEC 1A3 human cell line, TEC 1A3 AIREhi, to determine genes targeted by AIRE, and using microarray analysis, we identified 482 genes showing significant differential expression (P < 0.05; false discovery rate <5%), with 353 upregulated and 129 downregulated by AIRE expression. Microarray data were validated by quantitative PCR, confirming the differential expression of 12 known AIRE-regulated genes. Comparison of AIRE-dependent differential expression in our cell line model with murine datasets identified 447 conserved genes with a number of transcription regulatory interactions, forming several key nodes, including STAT1, which had over 30 interactions with other AIRE-regulated genes. As STAT1 mutations cause dominant chronic mucocutaneous candidiasis and decreased STAT1 levels in monocytes of autoimmune polyglandular syndrome 1 (APS-1) patients, it was important to further characterize AIRE–STAT1 interactions. TEC 1A3AIREhi were treated with the STAT1 phosphorylation inhibitors fludarabine and LLL3 showed that phosphorylated STAT1 (p-STAT1) was not responsible for any of the observed differential expression. Moreover, treatment of TEC 1A3 AIREhi with STAT1 shRNA did not induce any significant variation in the expression of unphosphorylated STAT1 (U-STAT1) downstream genes, suggesting that these genes were directly regulated by AIRE but not via U-STAT1. The novel model system we have developed provides potential opportunities for further analysis of the pathogenesis of (APS-1) and the wider roles of the AIRE gene.
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Affiliation(s)
- Thomas R J Lovewell
- Department of Infection, Immunity and Cardiovascular Disease, The Medical School, University of Sheffield, Sheffield, United Kingdom
| | - Andrew J G McDonagh
- Department of Dermatology, Royal Hallamshire Hospital, Sheffield, United Kingdom
| | - Andrew G Messenger
- Department of Dermatology, Royal Hallamshire Hospital, Sheffield, United Kingdom
| | - Mimoun Azzouz
- Department of Neuroscience, The Medical School, University of Sheffield, Sheffield, United Kingdom
| | - Rachid Tazi-Ahnini
- Department of Infection, Immunity and Cardiovascular Disease, The Medical School, University of Sheffield, Sheffield, United Kingdom
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AIRE promotes androgen-independent prostate cancer by directly regulating IL-6 and modulating tumor microenvironment. Oncogenesis 2018; 7:43. [PMID: 29795364 PMCID: PMC5968032 DOI: 10.1038/s41389-018-0053-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 03/29/2018] [Accepted: 04/23/2018] [Indexed: 01/01/2023] Open
Abstract
Early stage prostate cancers are dependent on androgens for their growth and survival and androgen withdrawal causes them to regress. Progressive prostate cancers eventually acquire androgen independence rendering anti-androgen therapy ineffective. However, the factors leading to this have not been adequately addressed. This study shows that AIRE finds differential expression in androgen-dependent and -independent prostate cancer cells. AIRE expression is more in androgen-independent cells due to its regulation by transcription factor Elk-1. These enhanced levels of AIRE modulate the prostate tumor microenvironment by transcriptionally activating a malignancy gene IL-6 in androgen-independent cells. Additionally, AIRE prevents the cancer cells from anticancer drug-induced death and enhances their invasiveness. Moreover, AIRE by modulating the cytokine milieu skews the tumor-associated macrophage polarization towards M2 phenotype with increased CD206 and CD163 expression. Subcutaneous mouse model of prostate cancer revealed AIRE+/+ mice forming a palpable tumor and presents lymphadenopathy however, only a small benign tumor is observed in AIRE−/− mice and lymph nodes appear normal in size. In conclusion, our findings suggest AIRE as a probable factor in promoting prostate cancer progression.
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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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Zhu W, Hu Z, Liao X, Chen X, Huang W, Zhong Y, Zeng Z. A new mutation site in the AIRE gene causes autoimmune polyendocrine syndrome type 1. Immunogenetics 2017; 69:643-651. [PMID: 28540407 DOI: 10.1007/s00251-017-0995-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Accepted: 04/26/2017] [Indexed: 01/07/2023]
Abstract
Autoimmune polyendocrine syndrome type 1 (APS-1, OMIM 2403000) is a rare autosomal recessive disease that is caused by autoimmune regulator (AIRE). The main symptoms of APS-1 are chronic mucocutaneous candidiasis, autoimmune adrenocortical insufficiency (Addison's disease) and hypoparathyroidism. We collected APS-1 cases and analysed them. The AIRE genes of the patient and his family members were sequenced to identify whether the APS-1 patient had an AIRE mutation. We discovered a mutation site (c.206A>C) that had never before been reported in the AIRE gene located in exon 2 of the AIRE gene. This homogyzous mutation caused a substitution of the 69th amino acid of the AIRE protein from glutamine to proline (p.Q69P). A yeast two-hybrid assay, which was used to analyse the homodimerization properties of the mutant AIRE protein, showed that the mutant AIRE protein could not interact with the normal AIRE protein. Flow cytometry and RT-qPCR analyses indicated that the new mutation site could decrease the expression levels of the AIRE, glutamic acid decarboxylase 65 (GAD65) and tryptophan hydroxylase-1 (TPH1) proteins to affect central immune tolerance. In conclusion, our research has shown that the new mutation site (c.206A>C) may influence the homodimerization and expression levels and other aspects of the AIRE protein. It may also impact the expression levels of tissue-restricted antigens (TRAs), leading to a series of autoimmune diseases.
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Affiliation(s)
- Wufei Zhu
- Department of Endocrinology, China Three Gorges University & Yichang Central People's Hospital, Yi Ling Road 181, Yichang, 443003, China.
| | - Zhen Hu
- Department of Endocrinology, China Three Gorges University & Yichang Central People's Hospital, Yi Ling Road 181, Yichang, 443003, China
| | - Xiangyu Liao
- Department of Endocrinology, China Three Gorges University & Yichang Central People's Hospital, Yi Ling Road 181, Yichang, 443003, China
| | - Xing Chen
- Department of Endocrinology, China Three Gorges University & Yichang Central People's Hospital, Yi Ling Road 181, Yichang, 443003, China
| | - Wenrong Huang
- Department of Endocrinology, China Three Gorges University & Yichang Central People's Hospital, Yi Ling Road 181, Yichang, 443003, China
| | - Yu Zhong
- Department of Endocrinology, China Three Gorges University & Yichang Central People's Hospital, Yi Ling Road 181, Yichang, 443003, China
| | - Zhaoyang Zeng
- Department of Endocrinology, China Three Gorges University & Yichang Central People's Hospital, Yi Ling Road 181, Yichang, 443003, China.
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Devarapu SK, Lorenz G, Kulkarni OP, Anders HJ, Mulay SR. Cellular and Molecular Mechanisms of Autoimmunity and Lupus Nephritis. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2017; 332:43-154. [PMID: 28526137 DOI: 10.1016/bs.ircmb.2016.12.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Autoimmunity involves immune responses directed against self, which are a result of defective self/foreign distinction of the immune system, leading to proliferation of self-reactive lymphocytes, and is characterized by systemic, as well as tissue-specific, inflammation. Numerous mechanisms operate to ensure the immune tolerance to self-antigens. However, monogenetic defects or genetic variants that weaken immune tolerance render susceptibility to the loss of immune tolerance, which is further triggered by environmental factors. In this review, we discuss the phenomenon of immune tolerance, genetic and environmental factors that influence the immune tolerance, factors that induce autoimmunity such as epigenetic and transcription factors, neutrophil extracellular trap formation, extracellular vesicles, ion channels, and lipid mediators, as well as costimulatory or coinhibitory molecules that contribute to an autoimmune response. Further, we discuss the cellular and molecular mechanisms of autoimmune tissue injury and inflammation during systemic lupus erythematosus and lupus nephritis.
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Affiliation(s)
- S K Devarapu
- Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Munich, Germany
| | - G Lorenz
- Klinikum rechts der Isar, Abteilung für Nephrologie, Technische Universität München, Munich, Germany
| | | | - H-J Anders
- Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Munich, Germany
| | - S R Mulay
- Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Munich, Germany.
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Soumya V, Padmanabhan RA, Titus S, Laloraya M. Murine uterine decidualization is a novel function of autoimmune regulator-beyond immune tolerance. Am J Reprod Immunol 2016; 76:224-34. [PMID: 27432359 DOI: 10.1111/aji.12538] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Accepted: 06/14/2016] [Indexed: 12/16/2023] Open
Abstract
PROBLEM Autoimmune polyendocrinopathy, candidiasis, and ectodermal dystrophy (APECED, APS-1) patients characterized by Aire (autoimmune regulator) mutations and Aire homozygous knockouts (Aire(-/-) ) exhibit infertility. It is not clear as to what contributes to infertility in the above. METHOD OF STUDY This study investigates the expression of "AIRE in the uterus" and its contribution to early pregnancy of mice by using quantitative real-time PCR analysis, immunohistochemistry, Western blotting, and in vivo Aire silencing experiments. RESULTS Aire (Isoform 1a) is expressed in the uterus during the "window of implantation" and decidualization. In vivo Aire silencing interfered with formation of implantation sites and stromal cell transformation by regulating bone morphogenetic protein-2,4 (Bmp2, Bmp4), homeobox A10 (Hoxa10), and insulin-like growth factor-binding protein 1(Igfbp1) leading to pregnancy failure. CONCLUSION Our consolidated results on extrathymic uterine expression of AIRE during early pregnancy and decidualization and impaired fertility on in vivo silencing are suggestive of its importance in pregnancy via a role beyond immune tolerance.
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Affiliation(s)
- Vasanthi Soumya
- Female Reproduction and Metabolic Syndromes Laboratory, Division of Molecular Reproduction, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India
| | - Renjini A Padmanabhan
- Female Reproduction and Metabolic Syndromes Laboratory, Division of Molecular Reproduction, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India
| | - Shiny Titus
- Female Reproduction and Metabolic Syndromes Laboratory, Division of Molecular Reproduction, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India
| | - Malini Laloraya
- Female Reproduction and Metabolic Syndromes Laboratory, Division of Molecular Reproduction, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India
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Crossland KL, Abinun M, Arkwright PD, Cheetham TD, Pearce SH, Hilkens CMU, Lilic D. AIRE is not essential for the induction of human tolerogenic dendritic cells. Autoimmunity 2016; 49:211-8. [PMID: 26912174 DOI: 10.3109/08916934.2016.1148692] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Loss-of-function mutations of the Autoimmune Regulator (AIRE) gene results in organ-specific autoimmunity and disease Autoimmune Polyendocrinopathy type 1 (APS1)/Autoimmune Polyendocrinopathy Candidiasis Ectodermal Dystrophy (APECED). The AIRE protein is crucial in the induction of central tolerance, promoting ectopic expression of tissue-specific antigens in medullary thymic epithelial cells and enabling removal of self-reactive T-cells. AIRE expression has recently been detected in myeloid dendritic cells (DC), suggesting AIRE may have a significant role in peripheral tolerance. DC stimulation of T-cells is critical in determining the initiation or lack of an immune response, depending on the pattern of costimulation and cytokine production by DCs, defining immunogenic/inflammatory (inflDC) and tolerogenic (tolDC) DC. In AIRE-deficient patients and healthy controls, we validated the role of AIRE in the generation and function of monocyte-derived inflDC and tolDCs by determining mRNA and protein expression of AIRE and comparing activation markers (HLA-DR/DP/DQ,CD83,CD86,CD274(PDL-1),TLR-2), cytokine production (IL-12p70,IL-10,IL-6,TNF-α,IFN-γ) and T-cell stimulatory capacity (mixed lymphocyte reaction) of AIRE+ and AIRE- DCs. We show for the first time that: (1) tolDCs from healthy individuals express AIRE; (2) AIRE expression is not significantly higher in tolDC compared to inflDC; (3) tolDC can be generated from APECED patient monocytes and (4) tolDCs lacking AIRE retain the same phenotype and reduced T-cell stimulatory function. Our findings suggest that AIRE does not have a role in the induction and function of monocyte-derived tolerogenic DC in humans, but these findings do not exclude a role for AIRE in peripheral tolerance mediated by other cell types.
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Affiliation(s)
- Katherine L Crossland
- a Primary Immune Deficiency Group, Institute of Cellular Medicine, Newcastle University , Newcastle upon Tyne , UK
| | - Mario Abinun
- a Primary Immune Deficiency Group, Institute of Cellular Medicine, Newcastle University , Newcastle upon Tyne , UK
- b Department of Paediatric Immunology , Great North Children's Hospital , Newcastle upon Tyne , UK
| | - Peter D Arkwright
- c Institute of Inflammation and Repair, University of Manchester , Manchester , UK
| | - Timothy D Cheetham
- d Department of Paediatric Endocrinology , Great North Children's Hospital , Newcastle upon Tyne , UK
| | - Simon H Pearce
- e Institute of Human Genetics, Newcastle University , Newcastle upon Tyne , UK
| | - Catharien M U Hilkens
- f Musculoskeletal Research Group, Institute of Cellular Medicine, Newcastle University , Newcastle upon Tyne , UK , and
| | - Desa Lilic
- a Primary Immune Deficiency Group, Institute of Cellular Medicine, Newcastle University , Newcastle upon Tyne , UK
- g Department of Regional Immunology and Allergy , Newcastle upon Tyne Hospitals NHS Trust , Newcastle upon Tyne , UK
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Nitta T, Suzuki H. Thymic stromal cell subsets for T cell development. Cell Mol Life Sci 2016; 73:1021-37. [PMID: 26825337 PMCID: PMC11108406 DOI: 10.1007/s00018-015-2107-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 11/26/2015] [Accepted: 12/01/2015] [Indexed: 12/20/2022]
Abstract
The thymus provides a specialized microenvironment in which a variety of stromal cells of both hematopoietic and non-hematopoietic origin regulate development and repertoire selection of T cells. Recent studies have been unraveling the inter- and intracellular signals and transcriptional networks for spatiotemporal regulation of development of thymic stromal cells, mainly thymic epithelial cells (TECs), and the molecular mechanisms of how different TEC subsets control T cell development and selection. TECs are classified into two functionally different subsets: cortical TECs (cTECs) and medullary TECs (mTECs). cTECs induce positive selection of diverse and functionally distinct T cells by virtue of unique antigen-processing systems, while mTECs are essential for establishing T cell tolerance via ectopic expression of peripheral tissue-restricted antigens and cooperation with dendritic cells. In addition to reviewing the role of the thymic stroma in conventional T cell development, we will discuss recently discovered novel functions of TECs in the development of unconventional T cells, such as natural killer T cells and γδT cells.
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Affiliation(s)
- Takeshi Nitta
- Department of Immunology and Pathology, Research Institute, National Center for Global Health and Medicine, Chiba, 272-8516, Japan.
| | - Harumi Suzuki
- Department of Immunology and Pathology, Research Institute, National Center for Global Health and Medicine, Chiba, 272-8516, Japan.
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12
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Abramson J, Goldfarb Y. AIRE: From promiscuous molecular partnerships to promiscuous gene expression. Eur J Immunol 2016; 46:22-33. [PMID: 26450177 DOI: 10.1002/eji.201545792] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 08/10/2015] [Accepted: 10/05/2015] [Indexed: 12/11/2022]
Abstract
Autoimmune regulator (AIRE) is a unique transcriptional regulator that induces promiscuous expression of thousands of tissue-restricted antigens (TRAs) in medullary thymic epithelial cells (mTECs), a step critical for the induction of immunological self-tolerance. The past 15 years have seen dramatic progress in our understanding of how AIRE induces immunological self-tolerance on a molecular level. This major advancement can be greatly attributed to the identification of a large variety of proteins that physically associate with AIRE, supporting and regulating its transcription-transactivation capacity. These diverse molecular partnerships have been shown to play roles in shuttling AIRE to the nucleus, securing AIRE's interaction with nuclear matrix and chromatin, releasing RNA polymerase-II from its stalled state and potentiating AIRE-mediated gene expression, among others. In this review we discuss the relationship of AIRE with its vast and rather diverse repertoire of partners and highlight how such "promiscuous partnerships" contribute to the phenomenon of "promiscuous gene expression" in the thymus.
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Affiliation(s)
- Jakub Abramson
- Department of Immunology, Weizmann Institute of Science, Rehovot, Israel
| | - Yael Goldfarb
- Department of Immunology, Weizmann Institute of Science, Rehovot, Israel
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Landegren N, Sharon D, Shum AK, Khan IS, Fasano KJ, Hallgren Å, Kampf C, Freyhult E, Ardesjö-Lundgren B, Alimohammadi M, Rathsman S, Ludvigsson JF, Lundh D, Motrich R, Rivero V, Fong L, Giwercman A, Gustafsson J, Perheentupa J, Husebye ES, Anderson MS, Snyder M, Kämpe O. Transglutaminase 4 as a prostate autoantigen in male subfertility. Sci Transl Med 2015; 7:292ra101. [PMID: 26084804 DOI: 10.1126/scitranslmed.aaa9186] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Autoimmune polyendocrine syndrome type 1 (APS1), a monogenic disorder caused by AIRE gene mutations, features multiple autoimmune disease components. Infertility is common in both males and females with APS1. Although female infertility can be explained by autoimmune ovarian failure, the mechanisms underlying male infertility have remained poorly understood. We performed a proteome-wide autoantibody screen in APS1 patient sera to assess the autoimmune response against the male reproductive organs. By screening human protein arrays with male and female patient sera and by selecting for gender-imbalanced autoantibody signals, we identified transglutaminase 4 (TGM4) as a male-specific autoantigen. Notably, TGM4 is a prostatic secretory molecule with critical role in male reproduction. TGM4 autoantibodies were detected in most of the adult male APS1 patients but were absent in all the young males. Consecutive serum samples further revealed that TGM4 autoantibodies first presented during pubertal age and subsequent to prostate maturation. We assessed the animal model for APS1, the Aire-deficient mouse, and found spontaneous development of TGM4 autoantibodies specifically in males. Aire-deficient mice failed to present TGM4 in the thymus, consistent with a defect in central tolerance for TGM4. In the mouse, we further link TGM4 immunity with a destructive prostatitis and compromised secretion of TGM4. Collectively, our findings in APS1 patients and Aire-deficient mice reveal prostate autoimmunity as a major manifestation of APS1 with potential role in male subfertility.
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Affiliation(s)
- Nils Landegren
- Department of Medicine (Solna), Karolinska University Hospital, Karolinska Institutet, Stockholm SE 171 76, Sweden. Department of Medical Sciences, Science for Life Laboratory, Uppsala University, Uppsala SE 751 85, Sweden.
| | - Donald Sharon
- Department of Genetics, Stanford University, Stanford 94305, CA, USA. Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Anthony K Shum
- Division of Pulmonary and Critical Care, Department of Medicine, University of California San Francisco, San Francisco, CA 94143, USA
| | - Imran S Khan
- Diabetes Center, University of California San Francisco, San Francisco, CA 94143, USA
| | - Kayla J Fasano
- Diabetes Center, University of California San Francisco, San Francisco, CA 94143, USA
| | - Åsa Hallgren
- Department of Medicine (Solna), Karolinska University Hospital, Karolinska Institutet, Stockholm SE 171 76, Sweden. Department of Medical Sciences, Science for Life Laboratory, Uppsala University, Uppsala SE 751 85, Sweden
| | - Caroline Kampf
- Department of Immunology, Genetics, and Pathology, Uppsala University, Uppsala SE 751 85, Sweden
| | - Eva Freyhult
- Cancer Pharmacology and Computational Medicine, Department of Medical Sciences, Bioinformatics Infrastructure for Life Sciences, Science for Life Laboratory, Uppsala University, Uppsala SE 751 85, Sweden
| | - Brita Ardesjö-Lundgren
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala SE 750 07, Sweden
| | - Mohammad Alimohammadi
- Department of Medicine (Solna), Karolinska University Hospital, Karolinska Institutet, Stockholm SE 171 76, Sweden. Department of Medical Sciences, Science for Life Laboratory, Uppsala University, Uppsala SE 751 85, Sweden. Department of Medical Sciences, Uppsala University, Uppsala SE 751 85, Sweden
| | - Sandra Rathsman
- Department of Laboratory Medicine/Microbiology, Örebro University Hospital, Örebro SE 701 85, Sweden
| | - Jonas F Ludvigsson
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm SE 171 76, Sweden
| | - Dan Lundh
- School of Bioscience, University of Skövde, Skövde SE 541 28, Sweden
| | - Ruben Motrich
- Centro de Investigaciones en Bioquímica Clínica e Inmunología, Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba 5000, Argentina
| | - Virginia Rivero
- Centro de Investigaciones en Bioquímica Clínica e Inmunología, Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba 5000, Argentina
| | - Lawrence Fong
- University of California San Francisco Helen Diller Family Comprehensive Cancer Center, San Francisco, CA 94115, USA
| | - Aleksander Giwercman
- Molecular Reproduction Research, Department of Clinical Sciences Malmö, Lund University, Malmö SE 205 02, Sweden
| | - Jan Gustafsson
- Department of Women's and Children's Health, Uppsala University, Uppsala SE 751 85, Sweden
| | - Jaakko Perheentupa
- The Hospital for Children and Adolescents, University of Helsinki, Helsinki 00029, Finland
| | - Eystein S Husebye
- Department of Clinical Science, University of Bergen, and Department of Medicine, Haukeland University Hospital, Bergen 5020, Norway
| | - Mark S Anderson
- Diabetes Center, University of California San Francisco, San Francisco, CA 94143, USA
| | - Michael Snyder
- Department of Genetics, Stanford University, Stanford 94305, CA, USA
| | - Olle Kämpe
- Department of Medicine (Solna), Karolinska University Hospital, Karolinska Institutet, Stockholm SE 171 76, Sweden. Department of Medical Sciences, Science for Life Laboratory, Uppsala University, Uppsala SE 751 85, Sweden
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14
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Van Gorp H, Kuchmiy A, Van Hauwermeiren F, Lamkanfi M. NOD-like receptors interfacing the immune and reproductive systems. FEBS J 2014; 281:4568-82. [PMID: 25154302 DOI: 10.1111/febs.13014] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 08/13/2014] [Accepted: 08/19/2014] [Indexed: 12/13/2022]
Abstract
Nucleotide-binding oligomerization domain receptors (NOD-like receptors, NLRs) are intracellular proteins that are chiefly known for their critical functions in inflammatory responses and host defense against microbial pathogens. Several NLRs have been demonstrated to assemble inflammasomes or to engage transcriptional signaling cascades that result in the production of pro-inflammatory cytokines and bactericidal factors. In recent years, NLRs have also emerged as key regulators of early mammalian embryogenesis and reproduction. A subset of phylogenetically related NLRs represents a new class of maternal effect genes that are highly expressed in maturing oocytes and pre-implantation embryos. Mutations in several of these NLRs have been linked to hereditary reproductive defects and imprinting diseases. In this review, we discuss the expression profiles, the emerging functions and molecular mode of action of these NLRs with newly recognized roles at the interfaces of the immune and reproductive systems. In addition, we provide an overview of coding mutations in NLRs that have been associated with human reproductive diseases, and outline crucial outstanding questions in this emerging research field.
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Affiliation(s)
- Hanne Van Gorp
- Department of Medical Protein Research, VIB, Ghent, Belgium; Department of Biochemistry, Ghent University, Ghent, Belgium
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15
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McLachlan SM, Rapoport B. Breaking tolerance to thyroid antigens: changing concepts in thyroid autoimmunity. Endocr Rev 2014; 35:59-105. [PMID: 24091783 PMCID: PMC3895862 DOI: 10.1210/er.2013-1055] [Citation(s) in RCA: 138] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Accepted: 09/24/2013] [Indexed: 02/06/2023]
Abstract
Thyroid autoimmunity involves loss of tolerance to thyroid proteins in genetically susceptible individuals in association with environmental factors. In central tolerance, intrathymic autoantigen presentation deletes immature T cells with high affinity for autoantigen-derived peptides. Regulatory T cells provide an alternative mechanism to silence autoimmune T cells in the periphery. The TSH receptor (TSHR), thyroid peroxidase (TPO), and thyroglobulin (Tg) have unusual properties ("immunogenicity") that contribute to breaking tolerance, including size, abundance, membrane association, glycosylation, and polymorphisms. Insight into loss of tolerance to thyroid proteins comes from spontaneous and induced animal models: 1) intrathymic expression controls self-tolerance to the TSHR, not TPO or Tg; 2) regulatory T cells are not involved in TSHR self-tolerance and instead control the balance between Graves' disease and thyroiditis; 3) breaking TSHR tolerance involves contributions from major histocompatibility complex molecules (humans and induced mouse models), TSHR polymorphism(s) (humans), and alternative splicing (mice); 4) loss of tolerance to Tg before TPO indicates that greater Tg immunogenicity vs TPO dominates central tolerance expectations; 5) tolerance is induced by thyroid autoantigen administration before autoimmunity is established; 6) interferon-α therapy for hepatitis C infection enhances thyroid autoimmunity in patients with intact immunity; Graves' disease developing after T-cell depletion reflects reconstitution autoimmunity; and 7) most environmental factors (including excess iodine) "reveal," but do not induce, thyroid autoimmunity. Micro-organisms likely exert their effects via bystander stimulation. Finally, no single mechanism explains the loss of tolerance to thyroid proteins. The goal of inducing self-tolerance to prevent autoimmune thyroid disease will require accurate prediction of at-risk individuals together with an antigen-specific, not blanket, therapeutic approach.
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Affiliation(s)
- Sandra M McLachlan
- Thyroid Autoimmune Disease Unit, Cedars-Sinai Research Institute, and University of California-Los Angeles School of Medicine, Los Angeles, California 90048
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16
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Perniola R, Musco G. The biophysical and biochemical properties of the autoimmune regulator (AIRE) protein. BIOCHIMICA ET BIOPHYSICA ACTA 2014; 1842:326-37. [PMID: 24275490 DOI: 10.1016/j.bbadis.2013.11.020] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2013] [Revised: 11/11/2013] [Accepted: 11/18/2013] [Indexed: 01/20/2023]
Abstract
AIRE (for autoimmune regulator) is a multidomain protein that performs a fundamental function in the thymus and possibly in the secondary lymphoid organs: the regulation, especially in the sense of activation, of the process of gene transcription in cell lines deputed to the presentation of self-antigens to the maturing T lymphocytes. The apoptosis of the elements bearing T-cell receptors with critical affinity for the exhibited self-antigens prevents the escape of autoreactive clones and represents a simple and efficient mechanism of deletional self-tolerance. However, AIRE action relies on an articulated complex of biophysical and biochemical properties, in most cases attributable to single subspecialized domains. Here a thorough review of the matter is presented, with a privileged look at the pathogenic changes of AIRE that interfere with such properties and lead to the impairment in its chief function.
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Affiliation(s)
- Roberto Perniola
- Department of Pediatrics - Neonatal Intensive Care, V. Fazzi Regional Hospital, Piazza F. Muratore, I-73100, Lecce, Italy.
| | - Giovanna Musco
- Biomolecular NMR Laboratory, Center of Translational Genomics and Bioinformatics, Dulbecco Telethon Institute at San Raffaele Scientific Institute, Via Olgettina 58, I-20132, Milan, Italy.
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17
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18
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Akiyama T, Shinzawa M, Qin J, Akiyama N. Regulations of gene expression in medullary thymic epithelial cells required for preventing the onset of autoimmune diseases. Front Immunol 2013; 4:249. [PMID: 23986760 PMCID: PMC3752772 DOI: 10.3389/fimmu.2013.00249] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Accepted: 08/09/2013] [Indexed: 11/13/2022] Open
Abstract
Elimination of potential self-reactive T cells in the thymus is crucial for preventing the onset of autoimmune diseases. Epithelial cell subsets localized in thymic medulla [medullary thymic epithelial cells (mTECs)] contribute to this process by supplying a wide range of self-antigens that are otherwise expressed in a tissue-specific manner (TSAs). Expression of some TSAs in mTECs is controlled by the autoimmune regulator (AIRE) protein, of which dysfunctional mutations are the causative factor of autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED). In addition to the elimination of self-reactive T cells, recent studies indicated roles of mTECs in the development of Foxp3-positive regulatory T cells, which suppress autoimmunity and excess immune reactions in peripheral tissues. The TNF family cytokines, RANK ligand, CD40 ligand, and lymphotoxin were found to promote the differentiation of AIRE- and TSA-expressing mTECs. Furthermore, activation of NF-κB is essential for mTEC differentiation. In this mini-review, we focus on molecular mechanisms that regulate induction of AIRE and TSA expression and discuss possible contributions of these mechanisms to prevent the onset of autoimmune diseases.
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Affiliation(s)
- Taishin Akiyama
- Division of Cellular and Molecular Biology, Institute of Medical Science, University of Tokyo , Tokyo , Japan
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19
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Si Y, Inoue K, Igarashi K, Kanno J, Imai Y. Autoimmune regulator, Aire, is a novel regulator of chondrocyte differentiation. Biochem Biophys Res Commun 2013; 437:579-84. [PMID: 23850677 DOI: 10.1016/j.bbrc.2013.07.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 07/01/2013] [Indexed: 01/23/2023]
Abstract
Chondrocyte differentiation is controlled by various regulators, such as Sox9 and Runx2, but the process is complex. To further understand the precise underlying molecular mechanisms of chondrocyte differentiation, we aimed to identify a novel regulatory factor of chondrocyte differentiation using gene expression profiles of micromass-cultured chondrocytes at different differentiation stages. From the results of microarray analysis, the autoimmune regulator, Aire, was identified as a novel regulator. Aire stable knockdown cells, and primary cultured chondrocytes obtained from Aire(-/-) mice, showed reduced mRNA expression levels of chondrocyte-related genes. Over-expression of Aire induced the early stages of chondrocyte differentiation by facilitating expression of Bmp2. A ChIP assay revealed that Aire was recruited on an Airebinding site (T box) in the Bmp2 promoter region in the early stages of chondrocyte differentiation and histone methylation was modified. These results suggest that Aire can facilitate early chondrocyte differentiation by expression of Bmp2 through altering the histone modification status of the promoter region of Bmp2. Taken together, Aire might play a role as an active regulator of chondrocyte differentiation, which leads to new insights into the regulatory mechanisms of chondrocyte differentiation.
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Affiliation(s)
- Yuan Si
- Laboratory of Epigenetic Skeletal Diseases, Institute of Molecular and Cellular Biosciences, The University of Tokyo, Japan
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20
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Lovewell T, Tazi-Ahnini R. Models to explore the molecular function and regulation of AIRE. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2011. [DOI: 10.1016/j.ejmhg.2011.06.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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21
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Abstract
The negative selection of self-reactive thymocytes depends on the expression of tissue-specific antigens by medullary thymic epithelial cells. The autoimmune regulator (Aire) protein plays an important role in turning on these antigens, and the absence of even one Aire-induced tissue-specific antigen in the thymus can lead to autoimmunity in the antigen-expressing target organ. Recently, Aire protein has been detected in peripheral lymphoid organs, suggesting that peripheral Aire plays a complementary role here. In these peripheral sites, Aire was found to regulate the expression of a group of tissue-specific antigens that is distinct from those expressed in the thymus. Furthermore, transgenic antigen expression in extrathymic Aire-expressing cells (eTACs) can mediate deletional tolerance, but the immunological relevance of Aire-dependent, endogenous tissue-specific antigens remains to be determined.
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Affiliation(s)
- Todd C Metzger
- Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA
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22
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Durrant LG, Pudney V, Spendlove I, Metheringham RL. Vaccines as early therapeutic interventions for cancer therapy: neutralising the immunosuppressive tumour environment and increasing T cell avidity may lead to improved responses. Expert Opin Biol Ther 2010; 10:735-48. [DOI: 10.1517/14712591003769790] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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23
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Org T, Rebane A, Kisand K, Laan M, Haljasorg U, Andreson R, Peterson P. AIRE activated tissue specific genes have histone modifications associated with inactive chromatin. Hum Mol Genet 2009; 18:4699-710. [PMID: 19744957 PMCID: PMC2778368 DOI: 10.1093/hmg/ddp433] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2009] [Accepted: 09/08/2009] [Indexed: 02/06/2023] Open
Abstract
The Autoimmune Regulator (AIRE) protein is expressed in thymic medullary epithelial cells, where it promotes the ectopic expression of tissue-restricted antigens needed for efficient negative selection of developing thymocytes. Mutations in AIRE cause APECED syndrome, which is characterized by a breakdown of self-tolerance. The molecular mechanism by which AIRE increases the expression of a variety of different genes remains unknown. Here, we studied AIRE-regulated genes using whole genome expression analysis and chromatin immunoprecipitation. We show that AIRE preferentially activates genes that are tissue-specific and characterized by low levels of initial expression in stably transfected HEK293 cell model and mouse thymic medullary epithelial cells. In addition, the AIRE-regulated genes lack active chromatin marks, such as histone H3 trimethylation (H3K4me3) and acetylation (AcH3), on their promoters. We also show that during activation by AIRE, the target genes acquire histone H3 modifications associated with transcription and RNA polymerase II. In conclusion, our data show that AIRE is able to promote ectopic gene expression from chromatin associated with histone modifications characteristic to inactive genes.
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Affiliation(s)
- Tõnis Org
- Department of Molecular Pathology, Institute of General and Molecular Pathology and
| | - Ana Rebane
- Department of Molecular Pathology, Institute of General and Molecular Pathology and
| | - Kai Kisand
- Department of Molecular Pathology, Institute of General and Molecular Pathology and
| | - Martti Laan
- Department of Molecular Pathology, Institute of General and Molecular Pathology and
| | - Uku Haljasorg
- Department of Molecular Pathology, Institute of General and Molecular Pathology and
| | - Reidar Andreson
- Department of Bioinformatics, Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Pärt Peterson
- Department of Molecular Pathology, Institute of General and Molecular Pathology and
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24
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Gardner JM, Fletcher AL, Anderson MS, Turley SJ. AIRE in the thymus and beyond. Curr Opin Immunol 2009; 21:582-9. [PMID: 19833494 PMCID: PMC2787634 DOI: 10.1016/j.coi.2009.08.007] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2009] [Revised: 08/21/2009] [Accepted: 08/25/2009] [Indexed: 01/09/2023]
Abstract
The maintenance of immunologic self-tolerance requires the coordination of multiple complementary systems. Studies of the Autoimmune Regulator (Aire) gene have revealed that Aire promotes self-tolerance partly by inducing the transcription of a wide array of tissue-specific antigens (TSAs), particularly in the thymus. The importance of Aire is highlighted by the fact that patients and mice defective in Aire expression develop a multi-organ autoimmune syndrome. In this review we discuss recent progress in our understanding of Aire's control of immune tolerance at the cellular and molecular levels, and also address the potential importance of Aire expression both in the thymus and in the peripheral lymphoid organs. The detection of both Aire and TSA expression by cell populations outside of the thymus raises the possibility that such expression may play a relevant role in the maintenance of self-tolerance.
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Affiliation(s)
- James M Gardner
- Diabetes Center and the Department of Medicine, University of California, San Francisco, CA 94143-0540, USA
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25
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Matsumoto M. The role of autoimmune regulator (Aire) in the development of the immune system. Microbes Infect 2009; 11:928-34. [PMID: 19615461 DOI: 10.1016/j.micinf.2009.07.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2009] [Accepted: 07/08/2009] [Indexed: 10/20/2022]
Abstract
AIRE is the gene responsible for a rather rare hereditary type of autoimmune disease. The mechanism underlying the autoimmune pathogenesis caused by AIRE deficiency is a focus of intense research because it could provide clues to the fundamental question of how the immune system discriminates between self and non-self within the thymic microenvironment.
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Affiliation(s)
- Mitsuru Matsumoto
- Division of Molecular Immunology, Institute for Enzyme Research, University of Tokushima, 3-18-15 Kuramoto, Tokushima 770-8503, Japan.
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26
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Macedo C, Evangelista AF, Magalhães DA, Fornari TA, Linhares LL, Junta CM, Silva GL, Sakamoto-Hojo ET, Donadi EA, Savino W, Passos GAS. Evidence for a network transcriptional control of promiscuous gene expression in medullary thymic epithelial cells. Mol Immunol 2009; 46:3240-4. [PMID: 19720399 DOI: 10.1016/j.molimm.2009.08.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Revised: 08/04/2009] [Accepted: 08/04/2009] [Indexed: 11/17/2022]
Abstract
The expression of peripheral tissue antigens (PTAs) in the thymus by medullary thymic epithelial cells (mTECs) is essential for the central self-tolerance in the generation of the T cell repertoire. Due to heterogeneity of autoantigen representation, this phenomenon has been termed promiscuous gene expression (PGE), in which the autoimmune regulator (Aire) gene plays a key role as a transcription factor in part of these genes. Here we used a microarray strategy to access PGE in cultured murine CD80(+) 3.10 mTEC line. Hierarchical clustering of the data allowed observation that PTA genes were differentially expressed being possible to found their respective induced or repressed mRNAs. To further investigate the control of PGE, we tested the hypothesis that genes involved in this phenomenon might also be modulated by transcriptional network. We then reconstructed such network based on the microarray expression data, featuring the guanylate cyclase 2d (Gucy2d) gene as a main node. In such condition, we established 167 positive and negative interactions with downstream PTA genes. Silencing Aire by RNA interference, Gucy2d while down regulated established a larger number (355) of interactions with PTA genes. T- and G-boxes corresponding to AIRE protein binding sites located upstream to ATG codon of Gucy2d supports this effect. These findings provide evidence that Aire plays a role in association with Gucy2d, which is connected to several PTA genes and establishes a cascade-like transcriptional control of promiscuous gene expression in mTEC cells.
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Affiliation(s)
- Cláudia Macedo
- Molecular Immunogenetics Group, Department of Genetics, Faculty of Medicine of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
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27
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Dooley J, Erickson M, Farr AG. Lessons from thymic epithelial heterogeneity: FoxN1 and tissue-restricted gene expression by extrathymic, endodermally derived epithelium. THE JOURNAL OF IMMUNOLOGY 2009; 183:5042-9. [PMID: 19786540 DOI: 10.4049/jimmunol.0901371] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Modeling of thymic epithelial differentiation has been guided by several important underlying assumptions. One is that within epithelial tissues derived from pharyngeal endoderm, FoxN1 expression is signature for the thymic epithelial lineage. Another is that expression of tissue-restricted Ag (TRA) is a unique feature of thymic epithelium. In this murine study, we evaluate the thymic expression of a subset of TRA, parathyroid hormone, calcitonin, and thyroglobulin, as part of an effort to better define the heterogeneity of medullary thymic epithelial cells. In this study, we demonstrate that both conventional and cystic epithelial cells display a history of FoxN1 expression using a cre-lox approach. We also document that extrathymic epithelial tissues that originate from pharyngeal endoderm also have a history of FoxN1 expression, indicating that FoxN1 expression per se is not a signature for the thymic lineage and suggesting that FoxN1 expression, whereas necessary for thymic epithelium, development, is not sufficient for this process to occur. Both cystic and conventional medullary thymic epithelial cells express these TRAs, as do extrathymic epithelial tissues that are not usually considered to be sources of these molecules. This finding supports the proposition that promiscuous gene expression is not unique to the thymus. Furthermore, the pattern of promiscuous gene expression in these extrathymic epithelia is consistent with developmental regulation processes and suggests that it is premature to discard the possibility that some promiscuous gene expression in the thymus reflects normal differentiation programs of epithelia.
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Affiliation(s)
- James Dooley
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
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28
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Misharin AV, Nagayama Y, Aliesky HA, Rapoport B, McLachlan SM. Studies in mice deficient for the autoimmune regulator (Aire) and transgenic for the thyrotropin receptor reveal a role for Aire in tolerance for thyroid autoantigens. Endocrinology 2009; 150:2948-56. [PMID: 19264867 PMCID: PMC2689795 DOI: 10.1210/en.2008-1690] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2008] [Accepted: 02/20/2009] [Indexed: 01/20/2023]
Abstract
The autoimmune regulator (Aire) mediates central tolerance for many autoantigens, and autoimmunity occurs spontaneously in Aire-deficient humans and mice. Using a mouse model of Graves' disease, we investigated the role of Aire in tolerance to the TSH receptor (TSHR) in Aire-deficient and wild-type mice (hyperthyroid-susceptible BALB/c background). Mice were immunized three times with TSHR A-subunit expressing adenovirus. The lack of Aire did not influence T-cell responses to TSHR protein or TSHR peptides. However, antibody levels were higher in Aire-deficient than wild-type mice after the second (but not the third) immunization. After the third immunization, hyperthyroidism persisted in a higher proportion of Aire-deficient than wild-type mice. Aire-deficient mice were crossed with transgenic strains expressing high or low-intrathyroidal levels of human TSHR A subunits. In the low-expressor transgenics, Aire deficiency had the same effect on the pattern of the TSHR antibody response to immunization as in nontransgenics, although the amplitude of the response was lower in the transgenics. High-expressor A-subunit transgenics were unresponsive to immunization. We examined intrathymic expression of murine TSHR, thyroglobulin, and thyroid peroxidase (TPO), the latter two being the dominant autoantigens in Hashimoto's thyroiditis (particularly TPO). Expression of the TSHR and thyroglobulin were reduced in the absence of Aire. Dramatically, thymic expression of TPO was nearly abolished. In contrast, the human A-subunit transgene, lacking a potential Aire-binding motif, was unaffected. Our findings provide insight into how varying intrathymic autoantigen expression may modulate thyroid autoimmunity and suggest that Aire deficiency may contribute more to developing Hashimoto's thyroiditis than Graves' disease.
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MESH Headings
- Animals
- Autoantigens/metabolism
- Disease Models, Animal
- Female
- Graves Disease/immunology
- Graves Disease/metabolism
- Graves Disease/pathology
- Hyperthyroidism/immunology
- Hyperthyroidism/metabolism
- Hyperthyroidism/pathology
- Immune Tolerance/immunology
- Immunoglobulins, Thyroid-Stimulating/immunology
- Immunoglobulins, Thyroid-Stimulating/metabolism
- Male
- Mice
- Mice, Inbred BALB C
- Mice, Knockout
- Mice, Transgenic
- Receptors, Thyrotropin/genetics
- Receptors, Thyrotropin/immunology
- Receptors, Thyrotropin/metabolism
- T-Lymphocytes, Regulatory/pathology
- Thyroid Gland/immunology
- Thyroid Gland/metabolism
- Thyroid Gland/pathology
- Transcription Factors/genetics
- Transcription Factors/physiology
- AIRE Protein
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Affiliation(s)
- Alexander V Misharin
- Autoimmune Disease Unit, Cedars-Sinai Research Institute and University of California Los Angeles School of Medicine, Los Angeles, California 90048, USA
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29
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Shikama N, Nusspaumer G, Holländer GA. Clearing the AIRE: on the pathophysiological basis of the autoimmune polyendocrinopathy syndrome type-1. Endocrinol Metab Clin North Am 2009; 38:273-88, vii. [PMID: 19328411 DOI: 10.1016/j.ecl.2009.01.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Autoimmune polyendocrine syndrome type-1 clinically manifests as the triad of hypoparathyroidism, primary adrenocortical insufficiency, and chronic mucocutaneous candidiasis. Mutations in the gene that encodes the autoimmune regulator protein, AIRE, have been identified as the cause of the autoimmune polyendocrine syndrome type-1. The loss of immunologic tolerance to tissue-restricted antigens consequent to an absence of AIRE expression in the thymus results in the thymic export of autoreactive T cells that initiate autoimmunity. In this article, we discuss the role of AIRE in autoimmune polyendocrine syndrome type-1 and identify issues that still need to be addressed to fully understand the molecular pathophysiology of this complex syndrome.
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Affiliation(s)
- Noriko Shikama
- Laboratory of Pediatric Immunology, Department of Biomedicine, University of Basel and The University Children's Hospital (UKBB), Basel, Switzerland
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30
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Abstract
A pool of immature T cells with a seemingly unrestricted repertoire of antigen specificities is generated life-long in the thymus. Amongst these cells are, however, thymocytes that express a strongly self-reactive antigen receptor and hence hold the potential to trigger autoimmunity. To prevent such an outcome, the thymus employs several independent but functionally related strategies that act in parallel to enforce self-tolerance. The deletion of strongly self-reactive thymocytes and the generation of regulatory T cells constitute the two most efficient mechanisms to induce and maintain immunological tolerance. Thymic epithelial cells of the medulla express for this purpose tissue-restricted self-antigens. This review will focus on the cellular and molecular mechanisms operative in the thymus to shape a repertoire of mature T cells tolerant to self-antigens.
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Affiliation(s)
- G A Holländer
- Department of Clinical-Biological Sciences, Laboratory of Pediatric Immunology, Center for Biomedicine, University of Basel and The University Children's Hospital, Switzerland.
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31
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Peterson P, Org T, Rebane A. Transcriptional regulation by AIRE: molecular mechanisms of central tolerance. Nat Rev Immunol 2008; 8:948-57. [PMID: 19008896 PMCID: PMC2785478 DOI: 10.1038/nri2450] [Citation(s) in RCA: 172] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The negative selection of T cells in the thymus is necessary for the maintenance of self tolerance. Medullary thymic epithelial cells have a key function in this process as they express a large number of tissue-specific self antigens that are presented to developing T cells. Mutations in the autoimmune regulator (AIRE) protein cause a breakdown of central tolerance that is associated with decreased expression of self antigens in the thymus. In this Review, we discuss the role of AIRE in the thymus and recent advances in our understanding of how AIRE might function at the molecular level to regulate gene expression.
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Affiliation(s)
- Pärt Peterson
- Institute of General and Molecular Pathology, University of Tartu, Tartu 5O411, Estonia.
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Musco G, Peterson P. PHD finger of autoimmune regulator: an epigenetic link between the histone modifications and tissue-specific antigen expression in thymus. Epigenetics 2008; 3:310-4. [PMID: 19011376 PMCID: PMC2635555 DOI: 10.4161/epi.3.6.7182] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Methylation of lysine residues on histone H3 tails regulates transcription. A recent addition to the list of known methylated histone binding modules is the plant homeodomain (PHD) finger, which is usually found in nuclear proteins with chromatin-related functions. Autoimmune regulator (AIRE) protein contains two PHD fingers and mutations in AIRE gene cause the monogenic disease autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED). AIRE is expressed in thymic medullary epithelial cells where it promotes the expression of tissue-specific antigens. However the mechanism by which AIRE controls gene expression is currently unknown and the function of its domains, in particular of its PHD fingers is still elusive and controversial. In this review we discuss recent works on AIRE PHD finger(s) providing a new link between the status of histone modifications and the regulation of tissue-specific antigen expression in thymus.
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Affiliation(s)
- Giovanna Musco
- Biomolecular NMR Laboratory; Dulbecco Telethon Institute c/o S. Raffaele Scientific Institute, Milan Italy
| | - Pärt Peterson
- Molecular Pathology; University of Tartu; Tartu Estonia
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Koh AS, Kuo AJ, Park SY, Cheung P, Abramson J, Bua D, Carney D, Shoelson SE, Gozani O, Kingston RE, Benoist C, Mathis D. Aire employs a histone-binding module to mediate immunological tolerance, linking chromatin regulation with organ-specific autoimmunity. Proc Natl Acad Sci U S A 2008; 105:15878-83. [PMID: 18840680 PMCID: PMC2572939 DOI: 10.1073/pnas.0808470105] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2008] [Indexed: 01/08/2023] Open
Abstract
Aire induces ectopic expression of peripheral tissue antigens (PTAs) in thymic medullary epithelial cells, which promotes immunological tolerance. Beginning with a broad screen of histone peptides, we demonstrate that the mechanism by which this single factor controls the transcription of thousands of genes involves recognition of the amino-terminal tail of histone H3, but not of other histones, by one of Aire's plant homeodomain (PHD) fingers. Certain posttranslational modifications of H3 tails, notably dimethylation or trimethylation at H3K4, abrogated binding by Aire, whereas others were tolerated. Similar PHD finger-H3 tail-binding properties were recently reported for BRAF-histone deacetylase complex 80 and DNA methyltransferase 3L; sequence alignment, molecular modeling, and biochemical analyses showed these factors and Aire to have structure-function relationships in common. In addition, certain PHD1 mutations underlying the polyendocrine disorder autoimmune polyendocrinopathy-candidiases-ectodermaldystrophy compromised Aire recognition of H3. In vitro binding assays demonstrated direct physical interaction between Aire and nucleosomes, which was in part buttressed by its affinity to DNA. In vivo Aire interactions with chromosomal regions depleted of H3K4me3 were dependent on its H3 tail-binding activity, and this binding was necessary but not sufficient for the up-regulation of genes encoding PTAs. Thus, Aire's activity as a histone-binding module mediates the thymic display of PTAs that promotes self-tolerance and prevents organ-specific autoimmunity.
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Affiliation(s)
- Andrew S. Koh
- *Research Division, Joslin Diabetes Center and Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02215
- Department of Molecular Biology, Massachusetts General Hospital and Department of Genetics, Harvard Medical School, Boston, MA, 02114; and
| | - Alex J. Kuo
- Department of Biology, Stanford University, Stanford, CA 94305
| | - Sang Youn Park
- *Research Division, Joslin Diabetes Center and Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02215
| | - Peggie Cheung
- Department of Biology, Stanford University, Stanford, CA 94305
| | - Jakub Abramson
- *Research Division, Joslin Diabetes Center and Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02215
| | - Dennis Bua
- Department of Biology, Stanford University, Stanford, CA 94305
| | - Dylan Carney
- Department of Biology, Stanford University, Stanford, CA 94305
| | - Steven E. Shoelson
- *Research Division, Joslin Diabetes Center and Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02215
| | - Or Gozani
- Department of Biology, Stanford University, Stanford, CA 94305
| | - Robert E. Kingston
- Department of Molecular Biology, Massachusetts General Hospital and Department of Genetics, Harvard Medical School, Boston, MA, 02114; and
| | - Christophe Benoist
- *Research Division, Joslin Diabetes Center and Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02215
| | - Diane Mathis
- *Research Division, Joslin Diabetes Center and Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02215
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Tazi-Ahnini R, McDonagh AJG, Wengraf DA, Lovewell TRJ, Vasilopoulos Y, Messenger AG, Cork MJ, Gawkrodger DJ. The autoimmune regulator gene (AIRE) is strongly associated with vitiligo. Br J Dermatol 2008; 159:591-6. [PMID: 18616774 DOI: 10.1111/j.1365-2133.2008.08718.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Vitiligo is an autoimmune disorder that occurs with greatly increased frequency in the rare recessive autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome (APECED) caused by mutations of the autoimmune regulator (AIRE) gene on chromosome 21q22.3. We have previously detected an association between alopecia areata and single nucleotide polymorphisms (SNPs) in the AIRE gene. OBJECTIVES To report the findings of an extended study including haplotype analysis on six AIRE polymorphisms (AIRE C-103T, C4144G, T5238C, G6528A, T7215C and T11787C) in vitiligo, another APECED-associated disease. METHODS A case-control analysis was performed. RESULTS Results showed a strong association between AIRE 7215C and vitiligo [P = 1.36 x 10(-5), odds ratio (OR) 3.12, 95% confidence interval (CI) 1.87-5.46]. We found no significant association with the other polymorphisms individually. However, haplotype analysis revealed that the AIRE haplotype CCTGCC showed a highly significant association with vitiligo (P = 4.14 x 10(-4), OR 3.00, 95% CI 1.70-5.28). To select the most informative minimal haplotypes, we tagged the polymorphisms using SNP tag software. Using AIRE C-103T, G6528A, T7215C and T11787C as tag SNPs, the haplotype AIRE CGCC was associated with vitiligo (P = 0.003, OR 2.49, 95% CI 1.45-4.26). CONCLUSIONS The link between vitiligo and AIRE raises the possibility that defective skin peripheral antigen selection in the thymus is involved in the changes that result in melanocyte destruction in this disorder.
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Affiliation(s)
- R Tazi-Ahnini
- Division of Genomic Medicine, University of Sheffield, Sheffield S10 2RX, UK.
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Org T, Chignola F, Hetényi C, Gaetani M, Rebane A, Liiv I, Maran U, Mollica L, Bottomley MJ, Musco G, Peterson P. The autoimmune regulator PHD finger binds to non-methylated histone H3K4 to activate gene expression. EMBO Rep 2008; 9:370-6. [PMID: 18292755 PMCID: PMC2261226 DOI: 10.1038/sj.embor.2008.11] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2007] [Revised: 12/07/2007] [Accepted: 01/09/2008] [Indexed: 12/28/2022] Open
Abstract
Mutations in the gene autoimmune regulator (AIRE) cause autoimmune polyendocrinopathy candidiasis ectodermal dystrophy. AIRE is expressed in thymic medullary epithelial cells, where it promotes the expression of tissue-restricted antigens. By the combined use of biochemical and biophysical methods, we show that AIRE selectively interacts with histone H3 through its first plant homeodomain (PHD) finger (AIRE-PHD1) and preferentially binds to non-methylated H3K4 (H3K4me0). Accordingly, in vivo AIRE binds to and activates promoters containing low levels of H3K4me3 in human embryonic kidney 293 cells. We conclude that AIRE-PHD1 is an important member of a newly identified class of PHD fingers that specifically recognize H3K4me0, thus providing a new link between the status of histone modifications and the regulation of tissue-restricted antigen expression in thymus.
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Affiliation(s)
- Tõnis Org
- Molecular Pathology, University of Tartu, Tartu 50411, Estonia
| | - Francesca Chignola
- Biomolecular NMR Laboratory, Dulbecco Telethon Institute c/o S. Raffaele Scientific Institute, Milan 20132, Italy
| | - Csaba Hetényi
- Institute of Chemical Physics, University of Tartu, Tartu 51010, Estonia
| | - Massimiliano Gaetani
- Biomolecular NMR Laboratory, Dulbecco Telethon Institute c/o S. Raffaele Scientific Institute, Milan 20132, Italy
| | - Ana Rebane
- Molecular Pathology, University of Tartu, Tartu 50411, Estonia
| | - Ingrid Liiv
- Molecular Pathology, University of Tartu, Tartu 50411, Estonia
| | - Uko Maran
- Institute of Chemical Physics, University of Tartu, Tartu 51010, Estonia
| | - Luca Mollica
- Biomolecular NMR Laboratory, Dulbecco Telethon Institute c/o S. Raffaele Scientific Institute, Milan 20132, Italy
| | - Matthew J Bottomley
- Istituto di Ricerche di Biologia Molecolare, via Pontina km 30.600, Pomezia (Rome), 00040, Italy
| | - Giovanna Musco
- Biomolecular NMR Laboratory, Dulbecco Telethon Institute c/o S. Raffaele Scientific Institute, Milan 20132, Italy
| | - Pärt Peterson
- Molecular Pathology, University of Tartu, Tartu 50411, Estonia
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Org T, Chignola F, Hetényi C, Gaetani M, Rebane A, Liiv I, Maran U, Mollica L, Bottomley MJ, Musco G, Peterson P. The autoimmune regulator PHD finger binds to non-methylated histone H3K4 to activate gene expression. EMBO Rep 2008. [PMID: 18292755 PMCID: PMC2261226 DOI: 10.1038/embor.2008.11] [Citation(s) in RCA: 156] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Mutations in the gene autoimmune regulator (AIRE) cause autoimmune polyendocrinopathy candidiasis ectodermal dystrophy. AIRE is expressed in thymic medullary epithelial cells, where it promotes the expression of tissue-restricted antigens. By the combined use of biochemical and biophysical methods, we show that AIRE selectively interacts with histone H3 through its first plant homeodomain (PHD) finger (AIRE–PHD1) and preferentially binds to non-methylated H3K4 (H3K4me0). Accordingly, in vivo AIRE binds to and activates promoters containing low levels of H3K4me3 in human embryonic kidney 293 cells. We conclude that AIRE–PHD1 is an important member of a newly identified class of PHD fingers that specifically recognize H3K4me0, thus providing a new link between the status of histone modifications and the regulation of tissue-restricted antigen expression in thymus.
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Affiliation(s)
- Tõnis Org
- Molecular Pathology, University of Tartu, Tartu 50411, Estonia
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Nitta T, Murata S, Ueno T, Tanaka K, Takahama Y. Thymic microenvironments for T-cell repertoire formation. Adv Immunol 2008; 99:59-94. [PMID: 19117532 DOI: 10.1016/s0065-2776(08)00603-2] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Functionally competent immune system includes a functionally competent T-cell repertoire that is reactive to foreign antigens but is tolerant to self-antigens. The repertoire of T cells is primarily formed in the thymus through positive and negative selection of developing thymocytes. Immature thymocytes that undergo V(D)J recombination of T-cell antigen receptor (TCR) genes and that express the virgin repertoire of TCRs are generated in thymic cortex. The recent discovery of thymoproteasomes, a molecular complex specifically expressed in cortical thymic epithelial cells (cTEC), has revealed a unique role of cTEC in cuing the further development of immature thymocytes in thymic cortex, possibly by displaying unique self-peptides that induce positive selection. Cortical thymocytes that receive TCR-mediated positive selection signals are destined to survive for further differentiation and are induced to express CCR7, a chemokine receptor. Being attracted to CCR7 ligands expressed by medullary thymic epithelial cells (mTEC), CCR7-expressing positively selected thymocytes relocate to thymic medulla. The medullary microenvironment displays another set of unique self-peptides for trimming positively selected T-cell repertoire to establish self-tolerance, via promiscuous expression of tissue-specific antigens by mTEC and efficient antigen presentation by dendritic cells. Recent results demonstrate that tumor necrosis factor (TNF) superfamily ligands, including receptor activating NF-kappaB ligand (RANKL), CD40L, and lymphotoxin, are produced by positively selected thymocytes and pivotally regulate mTEC development and thymic medulla formation.
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Affiliation(s)
- Takeshi Nitta
- Division of Experimental Immunology, Institute for Genome Research, University of Tokushima, Tokushima 770-8503, Japan
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