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Källberg E, Mehmeti-Ajradini M, Björk Gunnarsdottir F, Göransson M, Bergenfelz C, Allaoui Fredriksson R, Hagerling C, Johansson ME, Welinder C, Jirström K, Leandersson K. AIRE is expressed in breast cancer TANs and TAMs to regulate the extrinsic apoptotic pathway and inflammation. J Leukoc Biol 2024; 115:664-678. [PMID: 38060995 DOI: 10.1093/jleuko/qiad152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 11/02/2023] [Accepted: 11/19/2023] [Indexed: 04/02/2024] Open
Abstract
The autoimmune regulator (AIRE) is a transcriptional regulator expressed in the thymus and is necessary for maintaining immunological self-tolerance. Extrathymic AIRE expression is rare, and a role for AIRE in tumor-associated innate immune cells has not yet been established. In this study, we show that AIRE is expressed in human pro-tumor neutrophils. In breast cancer, AIRE was primarily located to tumor-associated neutrophils (TANs), and to a lesser extent to tumor-associated macrophages (TAMs) and tumor cells. Expression of AIRE in TAN/TAMs, but not in cancer cells, was associated with an adverse prognosis. We show that the functional role for AIRE in neutrophils and macrophages is to regulate expression of immune mediators and the extrinsic apoptotic pathway involving the Fas/TNFR death receptors and cathepsin G. Here, we propose that the role for AIRE in TAN/TAMs in breast tumors is to regulate cell death and inflammation, thus promoting tumor progression.
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Affiliation(s)
- Eva Källberg
- Cancer Immunology, Department of Translational Medicine, Lund University, Jan Waldenströmsg 35, 214 28 Malmö, Sweden
| | - Meliha Mehmeti-Ajradini
- Cancer Immunology, Department of Translational Medicine, Lund University, Jan Waldenströmsg 35, 214 28 Malmö, Sweden
| | - Frida Björk Gunnarsdottir
- Cancer Immunology, Department of Translational Medicine, Lund University, Jan Waldenströmsg 35, 214 28 Malmö, Sweden
| | - Marcus Göransson
- Cancer Immunology, Department of Translational Medicine, Lund University, Jan Waldenströmsg 35, 214 28 Malmö, Sweden
| | - Caroline Bergenfelz
- Cancer Immunology, Department of Translational Medicine, Lund University, Jan Waldenströmsg 35, 214 28 Malmö, Sweden
| | - Roni Allaoui Fredriksson
- Cancer Immunology, Department of Translational Medicine, Lund University, Jan Waldenströmsg 35, 214 28 Malmö, Sweden
| | - Catharina Hagerling
- Cancer Immunology, Department of Translational Medicine, Lund University, Jan Waldenströmsg 35, 214 28 Malmö, Sweden
| | - Martin E Johansson
- Sahlgrenska Center for Cancer Research, Department of Biomedicine, Vasaparken Universitetsplatsen 1, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Charlotte Welinder
- Mass Spectrometry, Department for Clinical Sciences, Lund University, Sölvegatan 19, 221 84 Lund, Sweden
| | - Karin Jirström
- Oncology and Therapeutic Pathology, Department of Clinical Sciences Lund, Lund University, Sölvegatan 19, 221 84 Lund, Sweden
| | - Karin Leandersson
- Cancer Immunology, Department of Translational Medicine, Lund University, Jan Waldenströmsg 35, 214 28 Malmö, Sweden
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2
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Sin JH, Sucharov J, Kashyap S, Wang Y, Proekt I, Liu X, Parent AV, Gupta A, Kastner P, Chan S, Gardner JM, Ntranos V, Miller CN, Anderson MS, Schjerven H, Waterfield MR. Ikaros is a principal regulator of Aire + mTEC homeostasis, thymic mimetic cell diversity, and central tolerance. Sci Immunol 2023; 8:eabq3109. [PMID: 37889983 DOI: 10.1126/sciimmunol.abq3109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 10/04/2023] [Indexed: 10/29/2023]
Abstract
Mutations in the gene encoding the zinc-finger transcription factor Ikaros (IKZF1) are found in patients with immunodeficiency, leukemia, and autoimmunity. Although Ikaros has a well-established function in modulating gene expression programs important for hematopoietic development, its role in other cell types is less well defined. Here, we uncover functions for Ikaros in thymic epithelial lineage development in mice and show that Ikzf1 expression in medullary thymic epithelial cells (mTECs) is required for both autoimmune regulator-positive (Aire+) mTEC development and tissue-specific antigen (TSA) gene expression. Accordingly, TEC-specific deletion of Ikzf1 in mice results in a profound decrease in Aire+ mTECs, a global loss of TSA gene expression, and the development of autoimmunity. Moreover, Ikaros shapes thymic mimetic cell diversity, and its deletion results in a marked expansion of thymic tuft cells and muscle-like mTECs and a loss of other Aire-dependent mimetic populations. Single-cell analysis reveals that Ikaros modulates core transcriptional programs in TECs that correlate with the observed cellular changes. Our findings highlight a previously undescribed role for Ikaros in regulating epithelial lineage development and function and suggest that failed thymic central tolerance could contribute to the autoimmunity seen in humans with IKZF1 mutations.
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Affiliation(s)
- Jun Hyung Sin
- Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, USA
- Department of Pediatrics, University of California San Francisco, San Francisco, CA, USA
| | - Juliana Sucharov
- Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, USA
| | - Sujit Kashyap
- Department of Pediatrics, University of California San Francisco, San Francisco, CA, USA
| | - Yi Wang
- Diabetes Center, University of California San Francisco, San Francisco, CA, USA
- 10x Genomics, Pleasanton, CA, USA
| | - Irina Proekt
- Diabetes Center, University of California San Francisco, San Francisco, CA, USA
| | - Xian Liu
- Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, USA
- Diabetes Center, University of California San Francisco, San Francisco, CA, USA
| | - Audrey V Parent
- Diabetes Center, University of California San Francisco, San Francisco, CA, USA
| | - Alexander Gupta
- Diabetes Center, University of California San Francisco, San Francisco, CA, USA
- Department of Surgery, University of California San Francisco, San Francisco, CA, USA
| | - Philippe Kastner
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U 1258, CNRS UMR 7104, Université de Strasbourg, 67404 Illkirch, France
| | - Susan Chan
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U 1258, CNRS UMR 7104, Université de Strasbourg, 67404 Illkirch, France
| | - James M Gardner
- Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, USA
- Diabetes Center, University of California San Francisco, San Francisco, CA, USA
- Department of Surgery, University of California San Francisco, San Francisco, CA, USA
| | - Vasilis Ntranos
- Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, USA
- Diabetes Center, University of California San Francisco, San Francisco, CA, USA
| | - Corey N Miller
- Diabetes Center, University of California San Francisco, San Francisco, CA, USA
| | - Mark S Anderson
- Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, USA
- Diabetes Center, University of California San Francisco, San Francisco, CA, USA
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Hilde Schjerven
- Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, USA
- Department of Laboratory Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Michael R Waterfield
- Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, USA
- Department of Pediatrics, University of California San Francisco, San Francisco, CA, USA
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3
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Zhang Y, Lu Y, Gao Y, Liang X, Zhang R, Wang X, Zou X, Yang W. Effects of Aire on perforin expression in BMDCs via TLR7/8 and its therapeutic effect on type 1 diabetes. Int Immunopharmacol 2023; 117:109890. [PMID: 36805202 DOI: 10.1016/j.intimp.2023.109890] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 01/30/2023] [Accepted: 02/11/2023] [Indexed: 02/19/2023]
Abstract
AIMS Type 1 diabetes, as a kind of autoimmune diseases, usually results from the broken-down of self-tolerance. Autoimmune regulator (Aire), as a transcription factor, induces peripheral tolerance by regulating Toll-like receptor (TLR) expression in dendritic cells (DCs). Several studies have recently identified a small population of perforin-expressing DCs, which is an important population of tolerogenic DCs (tolDCs) that restricts autoreactive T cells in vivo through a perforin-mediated mechanism. Thus, the present study explored the specific relationship among Aire, perforin-expressing DCs and immune tolerance, as well as their roles in type 1 diabetes. METHODS We conducted studies based on the Aire-overexpressing bone marrow-derived dendritic cell (BMDC) model. And through in vitro and in vivo experiments to observe that Aire-overexpressing BMDCs which express perforin induce immune tolerance and treat type 1 diabetes via TLR7/8. RESULTS Aire enhances the expression of perforin in BMDCs after treatment with the TLR7/8 ligand as well as promotes the expression of TLR7/8 and myeloid differentiation primary response gene 88 (MyD88)-dependent pathway molecules. Aire-overexpressing BMDCs mediate apoptosis of allogeneic CD8+ T cells via perforin in vitro. Moreover, Aire-overexpressing BMDCs enhance the therapeutic effect of type 1 diabetes in non-obese diabetic (NOD) mice via perforin and induce apoptosis of autoreactive CD8+ T cells in vivo. CONCLUSIONS These results provide an experimental basis for comprehensively elucidating the role and significance of Aire expression in peripheral DCs, thereby providing new ideas for the treatment of autoimmune diseases by using Aire as a target to induce the production of perforin-expressing DCs.
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Affiliation(s)
- Yi Zhang
- Department of Immunology, College of Basic Medical Sciences, Jilin University, Changchun, China
| | - Yaoping Lu
- Department of Immunology, College of Basic Medical Sciences, Jilin University, Changchun, China
| | - Yan Gao
- Department of Immunology, College of Basic Medical Sciences, Jilin University, Changchun, China
| | - Xiaojing Liang
- Department of Immunology, College of Basic Medical Sciences, Jilin University, Changchun, China
| | - Rongchao Zhang
- Department of Immunology, College of Basic Medical Sciences, Jilin University, Changchun, China
| | - Xiaoya Wang
- Department of Immunology, College of Basic Medical Sciences, Jilin University, Changchun, China
| | - Xueyang Zou
- Department of Immunology, College of Basic Medical Sciences, Jilin University, Changchun, China
| | - Wei Yang
- Department of Immunology, College of Basic Medical Sciences, Jilin University, Changchun, China.
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Nguyen CTK, Sawangarun W, Mandasari M, Morita KI, Harada H, Kayamori K, Yamaguchi A, Sakamoto K. AIRE is induced in oral squamous cell carcinoma and promotes cancer gene expression. PLoS One 2020; 15:e0222689. [PMID: 32012175 PMCID: PMC6996854 DOI: 10.1371/journal.pone.0222689] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 01/02/2020] [Indexed: 12/23/2022] Open
Abstract
Autoimmune regulator (AIRE) is a transcriptional regulator that is primarily expressed in medullary epithelial cells, where it induces tissue-specific antigen expression. Under pathological conditions, AIRE expression is induced in epidermal cells and promotes skin tumor development. This study aimed to clarify the role of AIRE in the pathogenesis of oral squamous cell carcinoma (OSCC). AIRE expression was evaluated in six OSCC cell lines and in OSCC tissue specimens. Expression of STAT1, ICAM1, CXCL10, CXCL11, and MMP9 was elevated in 293A cells stably expressing AIRE, and conversely, was decreased in AIRE-knockout HSC3 OSCC cells when compared to the respective controls. Upregulation of STAT1, and ICAM in OSCC cells was confirmed in tissue specimens by immunohistochemistry. We provide evidence that AIRE exerts transcriptional control in cooperation with ETS1. Expression of STAT1, ICAM1, CXCL10, CXCL11, and MMP9 was increased in 293A cells upon Ets1 transfection, and coexpression of AIRE further increased the expression of these proteins. AIRE coprecipitated with ETS1 in a modified immunoprecipitation assay using formaldehyde crosslinking. Chromatin immunoprecipitation and quantitative PCR analysis revealed that promoter fragments of STAT1, ICAM1, CXCL10, and MMP9 were enriched in the AIRE precipitates. These results indicate that AIRE is induced in OSCC and supports cancer-related gene expression in cooperation with ETS1. This is a novel function of AIRE in extrathymic tissues under the pathological condition.
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Affiliation(s)
- Chi Thi Kim Nguyen
- Department of Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Wanlada Sawangarun
- Department of Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Masita Mandasari
- Department of Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Kei-ichi Morita
- Department of Maxillofacial Surgery, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
- Bioresource Research Center, Tokyo Medical and Dental University, Tokyo, Japan
| | - Hiroyuki Harada
- Department of Oral and Maxillofacial Surgery, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Kou Kayamori
- Department of Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Akira Yamaguchi
- Department of Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
- Oral Health Science Center, Tokyo Dental College, Tokyo, Japan
| | - Kei Sakamoto
- Department of Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
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5
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Toraih EA, Ameen HM, Hussein MH, Youssef Elabd AA, Mohamed AM, Abdel-Gawad AR, Fawzy MS. Association of Autoimmune Regulator Gene Rs2075876 Variant, but Not Gene Expression with Alopecia Areata in Males: A Case-control Study. Immunol Invest 2020; 49:146-165. [PMID: 31601134 DOI: 10.1080/08820139.2019.1671450] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Alopecia areata (AA) is a non-scarring hair loss of autoimmune etiology. The autoimmune regulator (AIRE) gene is believed to be an important driver in AA pathogenesis. Genetic variants can alter mRNA expression levels which may provoke an autoimmune response. A total of 337 males (97 AA patients and 240 controls) were enrolled in the current case-control study. On screening of the most frequent variants in the gene, rs2075876 (A/G) polymorphism in intron 5 was selected and genotyped using Real-Time PCR (polymerase chain reaction) technology. Additionally, circulatory AIRE expression levels were quantified by quantitative reverse-transcription PCR (qRT-PCR). Allelic discrimination analysis revealed GG genotype to be more frequent in patients (90.7% in AA compared to 32.5% in controls, p < .001). G variant conferred increased risk to alopecia under homozygote comparison (GG versus AA: OR = 16.1, 95%CI = 5.57-46.3), dominant model (GG+AG versus AA: OR = 7.24, 95%CI = 2.5-20.5), recessive model (GG versus AG+AA: OR = 20.3, 95%CI = 9.7-42.4), and allelic model (G versus A: OR = 11.6, 95%CI = 6.47-21.1). The expression levels of AIRE gene did not differ significantly between patients and controls and were not related to rs2075876 variant. In conclusion, the intronic variant (rs2075876) is suggested to be a potent susceptibility variant for AA development in the studied population.Abbreviations: AA: Alopecia areata; AIRE: Autoimmune Regulator; APECED: Autoimmune, Polyendocrinopathy Candidiasis Ectodermal Dystrophy; DLQI: Dermatology life quality index questionnaire; MIQE: Minimum information for publication of quantitative real-time PCR experiments; mTEC: Medullary thymic epithelial cells; PHD: Plant homeodomain; qRT-PCR: Quantitative reversetranscription-polymerase chain reaction; RA: Rheumatoid arthritis.
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Affiliation(s)
- Eman A Toraih
- Genetics Unit, Department of Histology and Cell Biology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
- Center of Excellence of Molecular and Cellular Medicine, Suez Canal University, Ismailia, Egypt
| | - Hatem M Ameen
- Department of Dermatology, Al Qantara East Central Hospital, Ismailia, Egypt
| | - Mohammad H Hussein
- Department of Chest Diseases, Ministry of Health and Population, Cairo, Egypt
| | - Ahmed A Youssef Elabd
- Department of Dermatology, El-Sheikh Zaied Aal Nahyan hospital, Cairo, Egypt
- Department of Dermatology, Emirates Medical Center, Salalah Oman, Oman
| | - Abeer M Mohamed
- Department of Clinical Pathology and Clinical Chemistry, Faculty of Medicine, Sohag University, Sohag, Egypt
- Department of Clinical Laboratory Sciences, Al-Ghad International College for Applied Medical Sciences, Abha, Saudi Arabia
| | | | - Manal S Fawzy
- Deprtment of Biochemistry, Faculty of Medicine, Northern Border University, Arar, Saudi Arabia
- Department of Medical Biochemistry and Molecular Biology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
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6
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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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7
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Gu B, Lambert JP, Cockburn K, Gingras AC, Rossant J. AIRE is a critical spindle-associated protein in embryonic stem cells. eLife 2017; 6:e28131. [PMID: 28742026 PMCID: PMC5560860 DOI: 10.7554/elife.28131] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 07/17/2017] [Indexed: 12/21/2022] Open
Abstract
Embryonic stem (ES) cells go though embryo-like cell cycles regulated by specialized molecular mechanisms. However, it is not known whether there are ES cell-specific mechanisms regulating mitotic fidelity. Here we showed that Autoimmune Regulator (Aire), a transcription coordinator involved in immune tolerance processes, is a critical spindle-associated protein in mouse ES(mES) cells. BioID analysis showed that AIRE associates with spindle-associated proteins in mES cells. Loss of function analysis revealed that Aire was important for centrosome number regulation and spindle pole integrity specifically in mES cells. We also identified the c-terminal LESLL motif as a critical motif for AIRE's mitotic function. Combined maternal and zygotic knockout further revealed Aire's critical functions for spindle assembly in preimplantation embryos. These results uncovered a previously unappreciated function for Aire and provide new insights into the biology of stem cell proliferation and potential new angles to understand fertility defects in humans carrying Aire mutations.
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Affiliation(s)
- Bin Gu
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Canada
| | | | - Katie Cockburn
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Canada
| | - Anne-Claude Gingras
- Lunenfeld-Tanenbaum Research Institute at Mount Sinai Hospital, Toronto, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Janet Rossant
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
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8
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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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9
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Warren BD, Kinsey WK, McGinnis LK, Christenson LK, Jasti S, Stevens AM, Petroff BK, Petroff MG. Ovarian autoimmune disease: clinical concepts and animal models. Cell Mol Immunol 2014; 11:510-21. [PMID: 25327908 PMCID: PMC4220844 DOI: 10.1038/cmi.2014.97] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 09/11/2014] [Accepted: 09/11/2014] [Indexed: 01/08/2023] Open
Abstract
The ovary is not an immunologically privileged organ, but a breakdown in tolerogenic mechanisms for ovary-specific antigens has disastrous consequences on fertility in women, and this is replicated in murine models of autoimmune disease. Isolated ovarian autoimmune disease is rare in women, likely due to the severity of the disease and the inability to transmit genetic information conferring the ovarian disease across generations. Nonetheless, autoimmune oophoritis is often observed in association with other autoimmune diseases, particularly autoimmune adrenal disease, and takes a toll on both society and individual health. Studies in mice have revealed at least two mechanisms that protect the ovary from autoimmune attack. These mechanisms include control of autoreactive T cells by thymus-derived regulatory T cells, as well as a role for the autoimmune regulator (AIRE), a transcriptional regulator that induces expression of tissue-restricted antigens in medullary thymic epithelial cells during development of T cells. Although the latter mechanism is incompletely defined, it is well established that failure of either results in autoimmune-mediated targeting and depletion of ovarian follicles. In this review, we will address the clinical features and consequences of autoimmune-mediated ovarian infertility in women, as well as the possible mechanisms of disease as revealed by animal models.
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Affiliation(s)
- Bryce D Warren
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS, USA
| | - William K Kinsey
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Lynda K McGinnis
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Lane K Christenson
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Susmita Jasti
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Anne M Stevens
- Research Center for Immunity and Immunotherapies, Children's Hospital and Regional Medical Center, and Division of Rheumatology, Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - Brian K Petroff
- 1] Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS, USA [2] Present address: Department of Pathobiology and Diagnostic Investigation, Michigan State University College of Veterinary Medicine, East Lansing, MI, USA
| | - Margaret G Petroff
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS, USA
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10
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Incani F, Serra ML, Meloni A, Cossu C, Saba L, Cabras T, Messana I, Rosatelli MC. AIRE acetylation and deacetylation: effect on protein stability and transactivation activity. J Biomed Sci 2014; 21:85. [PMID: 25158603 PMCID: PMC4256887 DOI: 10.1186/s12929-014-0085-z] [Citation(s) in RCA: 18] [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: 06/17/2014] [Accepted: 08/16/2014] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The AIRE protein plays a remarkable role as a regulator of central tolerance by controlling the promiscuous expression of tissue-specific antigens in thymic medullary epithelial cells. Defects in AIRE gene cause the autoimmune polyendocrinopathy- candidiasis-ectodermal dystrophy, a rare disease frequent in Iranian Jews, Finns, and Sardinian population. RESULTS In this study, we have precisely mapped, by mass spectrometry experiments, the sites of protein acetylation and, by mutagenesis assays, we have described a set of acetylated lysines as being crucial in influencing the subcellular localization of AIRE. Furthermore, we have also determined that the de-acetyltransferase enzymes HDAC1-2 are involved in the lysine de-acetylation of AIRE. CONCLUSIONS On the basis of our results and those reported in literature, we propose a model in which lysines acetylation increases the stability of AIRE in the nucleus. In addition, we observed that the interaction of AIRE with deacetylases complexes inhibits its transcriptional activity and is probably responsible for the instability of AIRE, which becomes more susceptible to degradation in the proteasome.
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Affiliation(s)
- Federica Incani
- />Dipartimento di Sanità Pubblica, Medicina Clinica e Molecolare, Unità di Ricerca di Scienze Biomediche e Biotecnologie, Università degli Studi di Cagliari, via Jenner s/n, Cagliari, Italy
| | - Maria Luisa Serra
- />Dipartimento di Sanità Pubblica, Medicina Clinica e Molecolare, Unità di Ricerca di Scienze Biomediche e Biotecnologie, Università degli Studi di Cagliari, via Jenner s/n, Cagliari, Italy
| | - Alessandra Meloni
- />Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Cagliari, Italy
| | - Carla Cossu
- />Dipartimento di Sanità Pubblica, Medicina Clinica e Molecolare, Unità di Ricerca di Scienze Biomediche e Biotecnologie, Università degli Studi di Cagliari, via Jenner s/n, Cagliari, Italy
| | - Luisella Saba
- />Dipartimento di Sanità Pubblica, Medicina Clinica e Molecolare, Unità di Ricerca di Scienze Biomediche e Biotecnologie, Università degli Studi di Cagliari, via Jenner s/n, Cagliari, Italy
| | - Tiziana Cabras
- />Dipartimento di Scienze della Vita e dell’Ambiente, Sezione di Biochimica, Università degli Studi di Cagliari, Cagliari, Italy
| | - Irene Messana
- />Dipartimento di Scienze della Vita e dell’Ambiente, Sezione di Biochimica, Università degli Studi di Cagliari, Cagliari, Italy
| | - Maria Cristina Rosatelli
- />Dipartimento di Sanità Pubblica, Medicina Clinica e Molecolare, Unità di Ricerca di Scienze Biomediche e Biotecnologie, Università degli Studi di Cagliari, via Jenner s/n, Cagliari, Italy
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11
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Fernando R, Lu Y, Atkins SJ, Mester T, Branham K, Smith TJ. Expression of thyrotropin receptor, thyroglobulin, sodium-iodide symporter, and thyroperoxidase by fibrocytes depends on AIRE. J Clin Endocrinol Metab 2014; 99:E1236-44. [PMID: 24708100 PMCID: PMC4079309 DOI: 10.1210/jc.2013-4271] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 03/26/2014] [Indexed: 11/19/2022]
Abstract
CONTEXT CD34(+) fibrocytes, bone marrow-derived progenitor cells, infiltrate orbital connective tissue in thyroid-associated ophthalmopathy, a manifestation of Graves' disease. In the orbit, they become CD34(+) fibroblasts and coexist with native CD34(-) fibroblasts. Fibrocytes have been shown to express TSH receptor and thyroglobulin. OBJECTIVE The objective of the study was to determine whether a broader repertoire of thyroid protein expression can be detected in fibrocytes and whether a common factor is responsible. DESIGN/SETTING/PARTICIPANTS Fibrocytes and fibroblasts were collected and analyzed from healthy individuals and those with Graves' disease in an academic clinical practice. MAIN OUTCOME MEASURES Real-time PCR, Western blot analysis, gene promoter analysis, cell transfections, and flow cytometric cell sorting were performed. RESULTS We detect two additional thyroid proteins expressed by fibrocytes, namely sodium-iodide symporter and thyroperoxidase. The autoimmune regulator (AIRE) protein appears necessary for this expression. AIRE expression in fibrocytes results from an active AIRE gene promoter and stable AIRE mRNA. Knocking down AIRE with a targeting small interfering RNA reduces the expression of these thyroid proteins in fibrocytes as well as the transcription factors paired box-8 and thyroid transcription factor-1. When compared with an unaffected first-degree relative, levels of these proteins are substantially reduced in fibrocytes from an individual with an inactivating AIRE mutation. Levels of AIRE and the thyroid proteins are lower in orbital fibroblasts from patients with thyroid-associated ophthalmopathy than in fibrocytes. However, when mixed fibroblast populations are sorted into pure CD34(+) and CD34(-) subsets, the levels of these proteins are dramatically increased selectively in CD34(+) fibroblasts. CONCLUSIONS Fibrocytes express four proteins, the aggregate expression of which was previously thought to be restricted to thyroid epithelium. These proteins represent the necessary molecular biosynthetic machinery necessary for thyroid hormone production. Our findings implicate AIRE in the promiscuous expression of thyroid proteins in fibrocytes.
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Affiliation(s)
- Roshini Fernando
- Department of Ophthalmology and Visual Sciences (R.F., Y.L., S.J.A., T.M., K.B., T.J.S.), Kellogg Eye Center, and Division of Metabolism, Diabetes, and Endocrinology (T.J.S.), Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48105
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12
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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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13
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Perniola R. Expression of the autoimmune regulator gene and its relevance to the mechanisms of central and peripheral tolerance. Clin Dev Immunol 2012; 2012:207403. [PMID: 23125865 PMCID: PMC3485510 DOI: 10.1155/2012/207403] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Revised: 08/26/2012] [Accepted: 09/11/2012] [Indexed: 01/12/2023]
Abstract
The autoimmune polyendocrine syndrome type 1 (APS-1) is a monogenic disease due to pathogenic variants occurring in the autoimmune regulator (AIRE) gene. Its related protein, AIRE, activates the transcription of genes encoding for tissue-specific antigens (TsAgs) in a subset of medullary thymic epithelial cells: the presentation of TsAgs to the maturating thymocytes induces the apoptosis of the autoreactive clones and constitutes the main form of central tolerance. Dysregulation of thymic AIRE expression in genetically transmitted and acquired diseases other than APS-1 may contribute to further forms of autoimmunity. As AIRE and its murine homolog are also expressed in the secondary lymphoid organs, the extent and relevance of AIRE participation in the mechanisms of peripheral tolerance need to be thoroughly defined.
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Affiliation(s)
- Roberto Perniola
- Neonatal Intensive Care, Department of Pediatrics, V. Fazzi Regional Hospital, Piazza F. Muratore, 73100 Lecce, Italy.
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14
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Saare M, Rebane A, Rajashekar B, Vilo J, Peterson P. Autoimmune regulator is acetylated by transcription coactivator CBP/p300. Exp Cell Res 2012; 318:1767-78. [PMID: 22659170 DOI: 10.1016/j.yexcr.2012.04.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 04/12/2012] [Accepted: 04/17/2012] [Indexed: 11/17/2022]
Abstract
The Autoimmune Regulator (AIRE) is a regulator of transcription in the thymic medulla, where it controls the expression of a large set of peripheral-tissue specific genes. AIRE interacts with the transcriptional coactivator and acetyltransferase CBP and synergistically cooperates with it in transcriptional activation. Here, we aimed to study a possible role of AIRE acetylation in the modulation of its activity. We found that AIRE is acetylated in tissue culture cells and this acetylation is enhanced by overexpression of CBP and the CBP paralog p300. The acetylated lysines were located within nuclear localization signal and SAND domain. AIRE with mutations that mimicked acetylated K243 and K253 in the SAND domain had reduced transactivation activity and accumulated into fewer and larger nuclear bodies, whereas mutations that mimicked the unacetylated lysines were functionally similar to wild-type AIRE. Analogously to CBP, p300 localized to AIRE-containing nuclear bodies, however, the overexpression of p300 did not enhance the transcriptional activation of AIRE-regulated genes. Further studies showed that overexpression of p300 stabilized the AIRE protein. Interestingly, gene expression profiling revealed that AIRE, with mutations mimicking K243/K253 acetylation in SAND, was able to activate gene expression, although the affected genes were different and the activation level was lower from those regulated by wild-type AIRE. Our results suggest that the AIRE acetylation can influence the selection of AIRE activated genes.
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Affiliation(s)
- Mario Saare
- Molecular Pathology, Institute of General and Molecular Pathology, University of Tartu, 19th Ravila Str, Tartu, Estonia.
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15
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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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16
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Kumar V, Pedroza LA, Mace EM, Seeholzer S, Cotsarelis G, Condino-Neto A, Payne AS, Orange JS. The autoimmune regulator (AIRE), which is defective in autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy patients, is expressed in human epidermal and follicular keratinocytes and associates with the intermediate filament protein cytokeratin 17. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 178:983-8. [PMID: 21356351 PMCID: PMC3069874 DOI: 10.1016/j.ajpath.2010.12.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Revised: 11/02/2010] [Accepted: 12/01/2010] [Indexed: 12/22/2022]
Abstract
Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) syndrome, which is caused by mutation of the autoimmune regulator (AIRE) gene, is a highly variable disease characterized by multiple endocrine failure, chronic mucocutaneous candidiasis, and various ectodermal defects. AIRE is a transcriptional regulator classically expressed in medullary thymic epithelial cells, monocytes, macrophages, and dendritic cells. Previous studies have suggested that AIRE can shuttle between the nucleus and cytoplasm of cells, although its cytoplasmic functions are poorly characterized. Through mass spectrometry analysis of proteins co-immunoprecipitating with cytoplasmic AIRE, we identified a novel association of AIRE with the intermediate filament protein cytokeratin 17 (K17) in the THP-1 monocyte cell line. We confirmed AIRE expression in HaCaT epidermal keratinocytes, as well as its interaction with K17. Confocal microscopy of human fetal and adult scalp hair follicles demonstrated a cytoplasmic pattern of AIRE staining that moderately colocalized with K17. The cytoplasmic association of AIRE with the intermediate filament network in human epidermal and follicular keratinocytes may provide a new path to understanding the ectodermal abnormalities associated with the APECED syndrome.
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Affiliation(s)
- Vipul Kumar
- Division of Immunology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Luis A. Pedroza
- Division of Immunology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
- Department of Immunology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
- Center for Investigation in Pediatrics, School of Medicine, Campinas State University, Sao Paulo, Brazil
| | - Emily M. Mace
- Division of Immunology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Steven Seeholzer
- Division of Immunology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - George Cotsarelis
- Department of Dermatology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
| | - Antonio Condino-Neto
- Department of Immunology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Aimee S. Payne
- Department of Dermatology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
| | - Jordan S. Orange
- Division of Immunology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
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17
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Ko HJ, Kinkel SA, Hubert FX, Nasa Z, Chan J, Siatskas C, Hirubalan P, Toh BH, Scott HS, Alderuccio F. Transplantation of autoimmune regulator-encoding bone marrow cells delays the onset of experimental autoimmune encephalomyelitis. Eur J Immunol 2010; 40:3499-509. [PMID: 21108470 DOI: 10.1002/eji.201040679] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Revised: 08/12/2010] [Accepted: 09/02/2010] [Indexed: 01/04/2023]
Abstract
The autoimmune regulator (AIRE) promotes "promiscuous" expression of tissue-restricted antigens (TRA) in thymic medullary epithelial cells to facilitate thymic deletion of autoreactive T-cells. Here, we show that AIRE-deficient mice showed an earlier development of myelin oligonucleotide glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE). To determine the outcome of ectopic Aire expression, we used a retroviral transduction system to over-express Aire in vitro, in cell lines and in bone marrow (BM). In the cell lines that included those of thymic medullary and dendritic cell origin, ectopically expressed Aire variably promoted expression of TRA including Mog and Ins2 (proII) autoantigens associated, respectively, with the autoimmune diseases multiple sclerosis and type 1 diabetes. BM chimeras generated from BM transduced with a retrovirus encoding Aire displayed elevated levels of Mog and Ins2 expression in thymus and spleen. Following induction of EAE with MOG(35-55), transplanted mice displayed significant delay in the onset of EAE compared with control mice. To our knowledge, this is the first example showing that in vivo ectopic expression of AIRE can modulate TRA expression and alter autoimmune disease development.
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Affiliation(s)
- Hyun-Ja Ko
- Department of Immunology, Central Clinical School, Monash University, Melbourne, VIC, Australia
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18
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Colomé N, Collado J, Bech-Serra JJ, Liiv I, Antón LC, Peterson P, Canals F, Jaraquemada D, Alvarez I. Increased apoptosis after autoimmune regulator expression in epithelial cells revealed by a combined quantitative proteomics approach. J Proteome Res 2010; 9:2600-9. [PMID: 20218732 DOI: 10.1021/pr100044d] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare autosomal recessive autoimmune disease, affecting many endocrine tissues. APECED is associated to the lack of function of a single gene called AutoImmune REgulator (AIRE). Aire knockout mice develop various autoimmune disorders affecting different organs, indicating that Aire is a key gene in the control of organ-specific autoimmune diseases. AIRE is mainly expressed by medullary thymic epithelial cells (mTECs), and its absence results in the loss of tolerance against tissue restricted antigens (TRAs). Aire induces the transcription of genes encoding for TRAs in mTECs. In this report, the analysis of AIRE's effect on the cellular proteome was approached by the combination of two quantitative proteomics techniques, 2D-DIGE and ICPL, using an AIRE-transfected and nontransfected epithelial cell line. The results showed increased levels of several chaperones, (HSC70, HSP27 and tubulin-specific chaperone A) in AIRE-expressing cells, while various cytoskeleton interacting proteins, that is, transgelin, caldesmon, tropomyosin alpha-1 chain, myosin regulatory light polypeptide 9, and myosin-9, were decreased. Furthermore, some apoptosis-related proteins were differentially expressed. Data were confirmed by Western blot and flow cytometry analysis. Apoptosis assays with annexin V and etoposide demonstrated that AIRE-positive cells suffer more spontaneous apoptosis and are less resistant to apoptosis induction.
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Affiliation(s)
- Nuria Colomé
- Vall d'Hebron University Hospital, Barcelona, Spain
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19
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Sebastian J, Ravi M, Andreuzza S, Panoli AP, Marimuthu MPA, Siddiqi I. The plant adherin AtSCC2 is required for embryogenesis and sister-chromatid cohesion during meiosis in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2009; 59:1-13. [PMID: 19228337 DOI: 10.1111/j.1365-313x.2009.03845.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Adherin plays an important role in loading the cohesin complex onto chromosomes, and is essential for the establishment of sister-chromatid cohesion. We have identified and analyzed the Arabidopsis adherin homolog AtSCC2. Interestingly, the sequence analysis of AtSCC2 and of other putative plant adherin homologs revealed the presence of a PHD finger, which is not found in their fungal and animal counterparts. AtSCC2 is identical to EMB2773, and mutants show early embryo lethality and formation of giant endosperm nuclei. A role for AtSCC2 in sister-chromatid cohesion was established by using conditional RNAi and examining meiotic chromosome organization. AtSCC2-RNAi lines showed sterility, arising from the following defects in meiotic chromosome organization: failure of homologous pairing, loss of sister-chromatid cohesion, mixed segregation of chromosomes and chromosome fragmentation. The mutant phenotype, which included defects in chromosome organization and cohesion in prophase I, is distinct from that of the Arabidopsis cohesin mutant Atrec8, which retains centromere cohesion up to anaphase I. Immunostaining experiments revealed the aberrant distribution of the cohesin subunit AtSCC3 on chromosomes, and defects in chromosomal axis formation, in the meiocytes of AtSCC2-RNAi lines. These results demonstrate a role for AtSCC2 in sister-chromatid cohesion and centromere organization, and show that the machinery responsible for the establishment of cohesion is conserved in plants.
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Affiliation(s)
- Jose Sebastian
- Centre for Cellular & Molecular Biology, Uppal Road, Hyderabad 500007, India
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20
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Hubert FX, Kinkel SA, Crewther PE, Cannon PZF, Webster KE, Link M, Uibo R, O'Bryan MK, Meager A, Forehan SP, Smyth GK, Mittaz L, Antonarakis SE, Peterson P, Heath WR, Scott HS. Aire-deficient C57BL/6 mice mimicking the common human 13-base pair deletion mutation present with only a mild autoimmune phenotype. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2009; 182:3902-18. [PMID: 19265170 DOI: 10.4049/jimmunol.0802124] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Autoimmune regulator (AIRE) is an important transcription regulator that mediates a role in central tolerance via promoting the "promiscuous" expression of tissue-specific Ags in the thymus. Although several mouse models of Aire deficiency have been described, none has analyzed the phenotype induced by a mutation that emulates the common 13-bp deletion in human APECED (autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy) by disrupting the first plant homeodomain in exon 8. Aire-deficient mice with a corresponding mutation showed some disturbance of the medullary epithelial compartment, but at the phenotypic level their T cell compartment appeared relatively normal in the thymus and periphery. An increase in the number of activated T cells was evident, and autoantibodies against several organs were detected. At the histological level, lymphocytic infiltration of several organs indicated the development of autoimmunity, although symptoms were mild and the quality of life for Aire-deficient mice appeared equivalent to wild-type littermates, with the exception of male infertility. Vbeta and CDR3 length analysis suggested that each Aire-deficient mouse developed its own polyclonal autoimmune repertoire. Finally, given the prevalence of candidiasis in APECED patients, we examined the control of infection with Candida albicans in Aire-deficient mice. No increase in disease susceptibility was found for either oral or systemic infection. These observations support the view that additional genetic and/or environmental factors contribute substantially to the overt nature of autoimmunity associated with Aire mutations, even for mutations identical to those found in humans with APECED.
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Affiliation(s)
- François-Xavier Hubert
- Division of Immunology, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
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Abstract
Mutations in the transcriptional regulator, Aire, cause APECED, a polyglandular autoimmune disease with monogenic transmission. Animal models of APECED have revealed that Aire plays an important role in T cell tolerance induction in the thymus, mainly by promoting ectopic expression of a large repertoire of transcripts encoding proteins normally restricted to differentiated organs residing in the periphery. The absence of Aire results in impaired clonal deletion of self-reactive thymocytes, which escape into the periphery and attack a variety of organs. In addition, Aire is a proapoptotic factor, expressed at the final maturation stage of thymic medullary epithelial cells, a function that may promote cross-presentation of the antigens encoded by Aire-induced transcripts in these cells. Transcriptional regulation by Aire is unusual in being very broad, context-dependent, probabilistic, and noisy. Structure/function analyses and identification of its interaction partners suggest that Aire may impact transcription at several levels, including nucleosome displacement during elongation and transcript splicing or other aspects of maturation.
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Affiliation(s)
- Diane Mathis
- Section on Immunology and Immunogenetics, Joslin Diabetes Center; Department of Medicine, Brigham and Women's Hospital; Harvard Medical School; and the Harvard Stem Cell Institute, Boston, Massachusetts 02215, USA.
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22
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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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23
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Effects of trichostatin A on neuronal mu-opioid receptor gene expression. Brain Res 2008; 1246:1-10. [PMID: 18950606 DOI: 10.1016/j.brainres.2008.09.083] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2008] [Revised: 09/17/2008] [Accepted: 09/19/2008] [Indexed: 11/21/2022]
Abstract
In this study, we determined the effects of a histone deacetylase (HDAC) inhibitor, trichostatin A (TSA), on neuronal mu-opioid receptor (MOR) gene expression using human neuronal NMB cells, endogenously expressing MOR. Recruitment of two classes of HDAC, HDAC1 and HDAC2, to MOR promoter region in situ was detected via chromatin immunoprecipitation (ChIP) analysis with NMB cells. Functional analysis using the luciferase reporter gene system showed that TSA induced an approximately 3-fold increase of the promoter activity as compared to the vehicle treated group. Mutation analysis demonstrated that TSA response was mediated by both dsDNA (Sp1/Sp3 binding site) and ssDNA (PolyC binding protein1, PCBP, binding site) elements located in mouse MOR proximal core promoter region, further suggesting the functional importance of this cis-element, which shows high sequence homology between human and mouse MOR genes. ChIP analysis further suggested that TSA enhanced the recruitment of Sp1/Sp3 and PCBP to the promoter region, whereas no significant changes of total proteins were observed in response to TSA using Western blot analysis. Moreover, confocal images showed TSA-induced nuclear hot spots of endogenous PCBP in neuronal cells, whereas no obvious nuclear PCBP hotspot was observed in vehicle treated cells. Taken together, these results suggested that TSA enhanced neuronal MOR gene expression at the transcriptional level. RT-PCR analysis further revealed that TSA also decreased the steady-state level of MOR mRNA in a time-dependent manner by enhancing its instability. Thus, data suggest that TSA, an epigenetic regulator, affects neuronal MOR gene expression at both transcriptional and post-transcriptional levels.
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Berry AM, Flock KE, Loh HH, Ko JL. Molecular basis of cellular localization of poly C binding protein 1 in neuronal cells. Biochem Biophys Res Commun 2006; 349:1378-86. [PMID: 16979592 PMCID: PMC1618817 DOI: 10.1016/j.bbrc.2006.09.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2006] [Accepted: 09/01/2006] [Indexed: 11/26/2022]
Abstract
Poly C binding protein 1 (PCBP) is involved in the transcriptional regulation of neuronal mu-opioid receptor gene. In this study, we examined the molecular basis of PCBP cellular/nuclear localization in neuronal cells using EGFP fusion protein. PCBP, containing three KH domains and a variable domain, distributed in cytoplasm and nucleus with a preferential nuclear expression. Domain-deletional analyses suggested the requirement of variable and KH3 domains for strong PCBP nuclear expression. Within the nucleus, a low nucleolar PCBP expression was observed, and PCBP variable domain contributed to this restricted nucleolar expression. Furthermore, the punctate nuclear pattern of PCBP was correlated to its single-stranded (ss) DNA binding ability, with both requiring cooperativity of at least three sequential domains. Collectively, certain PCBP domains thus govern its nuclear distribution and transcriptional regulatory activity in the nucleus of neurons, whereas the low nucleolar expression implicates the disengagement of PCBP in the ribosomal RNA synthesis.
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Affiliation(s)
- Andrea M Berry
- Department of Biology, Seton Hall University, 208 McNulty Hall, 400 South Orange Avenue, South Orange, NJ 07079, USA
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25
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Klamp T, Sahin U, Kyewski B, Schwendemann J, Dhaene K, Türeci O. Expression profiling of autoimmune regulator AIRE mRNA in a comprehensive set of human normal and neoplastic tissues. Immunol Lett 2006; 106:172-9. [PMID: 16876259 DOI: 10.1016/j.imlet.2006.06.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2006] [Revised: 06/13/2006] [Accepted: 06/15/2006] [Indexed: 01/17/2023]
Abstract
Defects in the autoimmune regulator (AIRE) gene cause the monogenic autoimmune disease autoimmune polyendocrinopathy syndrome type 1 (APS-1), which is characterized by a loss of self-tolerance to multiple organs. In concordance with its role in immune tolerance, AIRE is strongly expressed in medullary thymic epithelial cells (mTECs). Data on mechanisms controlling AIRE activation and the expression of this gene in other tissues are fragmentary and controversial. We report here AIRE mRNA expression profiling of a large set of normal human tissues and cells, tumor specimen and methylation deficient cell lines. On this broad data basis we found that AIRE mRNA expression is confined to mTECs in thymus and to lymph node tissue and that DNA hypomethylation contributes to transcriptional control of this gene.
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MESH Headings
- Cell Line, Tumor
- DNA Methylation
- Gene Expression Profiling/methods
- Gene Expression Regulation, Neoplastic
- Humans
- Immune Tolerance/genetics
- Lymph Nodes/immunology
- Lymph Nodes/metabolism
- Lymph Nodes/pathology
- Neoplasms/genetics
- Neoplasms/immunology
- Neoplasms/metabolism
- Neoplasms/pathology
- Polyendocrinopathies, Autoimmune/genetics
- Polyendocrinopathies, Autoimmune/immunology
- Polyendocrinopathies, Autoimmune/metabolism
- Polyendocrinopathies, Autoimmune/pathology
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- RNA, Messenger/immunology
- Reverse Transcriptase Polymerase Chain Reaction
- Thymus Gland/immunology
- Thymus Gland/metabolism
- Thymus Gland/pathology
- Transcription Factors/biosynthesis
- Transcription Factors/immunology
- Transcription, Genetic/immunology
- AIRE Protein
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Affiliation(s)
- Thorsten Klamp
- Department of Internal Medicine III, Johannes-Gutenberg University Mainz, Obere Zahlbacherstr 63, 55131 Mainz, Germany
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26
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There and back again: Autoimmune Polyendocrinopathy Syndrome Type I and the Aire knockout mouse. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.ddmod.2006.03.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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27
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Kurobe H, Liu C, Ueno T, Saito F, Ohigashi I, Seach N, Arakaki R, Hayashi Y, Kitagawa T, Lipp M, Boyd RL, Takahama Y. CCR7-Dependent Cortex-to-Medulla Migration of Positively Selected Thymocytes Is Essential for Establishing Central Tolerance. Immunity 2006; 24:165-77. [PMID: 16473829 DOI: 10.1016/j.immuni.2005.12.011] [Citation(s) in RCA: 213] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2005] [Revised: 10/31/2005] [Accepted: 12/27/2005] [Indexed: 01/05/2023]
Abstract
Immature CD4+CD8+ thymocytes, which are generated in the thymic cortex, are induced upon positive selection to differentiate into mature T lymphocytes and relocate to the thymic medulla. It was recently shown that a chemokine signal via CCR7 is essential for the cortex-to-medulla migration of positively selected thymocytes in the thymus. However, the role of the cortex-to-medulla migration in T cell development and selection has remained unclear. The present study shows that the developmental kinetics and the thymic export of mature thymocytes were undisturbed in adult mice lacking CCR7 or its ligands (CCR7L). The inhibition of sphingosine-1-phosphate-mediated lymphocyte egress from the thymus led to the accumulation of mature thymocytes in the cortex of CCR7- or CCR7L-deficient mice, unlike the accumulation in the medulla of normal mice, thereby suggesting that mature thymocytes may be exported directly from the cortex in the absence of CCR7 signals. However, the thymocytes that were generated in the absence of CCR7 or CCR7L were potent in causing autoimmune dacryoadenitis and sialadenitis in mice and were thus incapable of establishing central tolerance to organ-specific antigens. These results indicate that CCR7-mediated cortex-to-medulla migration of thymocytes is essential for establishing central tolerance rather than for supporting the maturation or export of thymocytes.
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Affiliation(s)
- Hirotsugu Kurobe
- Division of Experimental Immunology, Institute for Genome Research, University of Tokushima, Tokushima 770-8503, Japan
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28
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Abstract
Far from being mutually exclusive, immunodeficiency and autoimmunity may occur simultaneously. During the last years, analysis of Autoimmune Polyendocrinopathy--Candidiasis--Ectodermal Dystrophy (APECED) and Immunodysregulation--Polyendocrinopathy--Enteropathy--X-linked (IPEX), two rare monogenic forms of immunodeficiency associated with autoimmunity, has led to the identification of Auto Immune Regulator (AIRE) and Forkhead Box P3 (FOXP3), essential transcriptional regulators, involved in central tolerance and peripheral immune homeostasis, respectively. Characterization of the molecular and cellular mechanisms involved in APECED, and recognition that AIRE expression is sustained by effective thymopoiesis, has recently allowed to define that the autoimmunity of Omenn syndrome, a combined immunodeficiency due to defects of V(D)J recombination, also results from defective expression of AIRE. The implications of identification of the basis of autoimmunity in these rare forms of immunodeficiency have important implications for a better understanding of more common autoimmune disorders, and for development of novel therapeutic approaches.
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Affiliation(s)
- Luigi D Notarangelo
- Angelo Nocivelli Institute for Molecular Medicine, Department of Pediatrics, University of Brescia, Brescia, Italy
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29
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Ilmarinen T, Melén K, Kangas H, Julkunen I, Ulmanen I, Eskelin P. The monopartite nuclear localization signal of autoimmune regulator mediates its nuclear import and interaction with multiple importin alpha molecules. FEBS J 2006; 273:315-24. [PMID: 16403019 DOI: 10.1111/j.1742-4658.2005.05065.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Autoimmune regulator (AIRE) is a transcriptional regulator involved in establishing immunological self-tolerance. Mutations in the AIRE gene lead to the development of the autosomal, recessively inherited, organ-specific autoimmune disease, autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED). The AIRE protein is mainly localized in the cell nucleus where it is associated with nuclear bodies. The N-terminal part of AIRE has been previously shown to mediate nuclear localization of the protein. However, the functional nuclear localization signal (NLS) and nuclear import mechanisms of AIRE have not been identified. We show that, although the amino-acid sequence of AIRE contains a potential bipartite NLS consisting of amino acids 110-114 and 131-133, only the latter part constitutes a functional NLS. Furthermore, we show by in vitro binding assays that AIRE interacts with multiple members of the nuclear transport receptor importin alpha family, mainly alpha1, alpha3, and alpha5, and that these interactions depend on the intactness of the Arg-Lys-rich NLS of AIRE. In addition, we found that AIRE binds to the 'minor' NLS-binding site of importin alpha3 and alpha5 proteins consisting of the C-terminal armadillo repeats 7-9. Our findings strongly suggest that the nuclear import of AIRE is mediated by the classical importin alpha/beta pathway through binding to several importin alpha family members.
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Affiliation(s)
- Tanja Ilmarinen
- Department of Molecular Medicine, National Public Health Institute, Helsinki, Finland.
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30
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Ulinski T, Perrin L, Morris M, Houang M, Cabrol S, Grapin C, Chabbert-Buffet N, Bensman A, Deschênes G, Giurgea I. Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome with renal failure: impact of posttransplant immunosuppression on disease activity. J Clin Endocrinol Metab 2006; 91:192-5. [PMID: 16263818 DOI: 10.1210/jc.2005-1538] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare autosomal recessive disorder caused by mutations in the gene AIRE (autoimmune regulator). APECED affects mainly endocrine organs resulting in hypoparathyroidism, adrenocortical failure, diabetes mellitus, hypogonadism, and hypothyroidism. Nonendocrine organ manifestations are autoimmune hepatitis, vitiligo, pernicious anemia, exocrine pancreatic insufficiency, and alopecia. APECED's first manifestation generally is mucocutaneous candidiasis presumably related to T cell dysfunction. PATIENT A 5-yr-old Iranian girl presented first with pernicious anemia, exocrine pancreatic insufficiency, and nail candidiasis. She had renal dysfunction due to chronic interstitial nephritis (CIN), which progressed to end-stage renal failure. She was transplanted 1 yr later. Common causes of CIN were excluded. APECED was suspected first because she developed progressively hypoparathyroidism, adrenocortical failure, glucose intolerance, and hypothyroidism. RESULTS Genetic analysis revealed a large homozygous deletion (g.424_2157del1734), spanning exons 2-4, in the AIRE gene. The predicted protein, if it is produced, has only 44 amino acids (exon 1) in common with the wild-type protein. Immunosuppression after the first renal transplant included prednisone, azathioprine, and cyclosporine A. Multiple acute rejection episodes occurred. Chronic rejection resulted in lost graft and she was retransplanted 2 yr later. Surprisingly, all APECED-related symptoms including candidiasis and autoantibody levels decreased, presumably due to the reinforced immunosuppression (tacrolimus, mycophenolate mofetil, prednisone). CONCLUSIONS This is the first report of an APECED patient with CIN resulting in end-stage renal failure. Clinical and biological improvement was observed under posttransplant multidrug immunosuppression including tacrolimus and mycophenolate mofetil.
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Affiliation(s)
- Tim Ulinski
- Department of Pediatric Nephrology, Hôpital Trousseau, 75571 Paris Cedex 12, France.
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31
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Ulmanen I, Halonen M, Ilmarinen T, Peltonen L. Monogenic autoimmune diseases — lessons of self-tolerance. Curr Opin Immunol 2005; 17:609-15. [PMID: 16226439 DOI: 10.1016/j.coi.2005.09.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2005] [Accepted: 09/20/2005] [Indexed: 12/21/2022]
Abstract
The molecular defects recently identified in the rare monogenic autoimmune diseases (AIDs) have pinpointed critical steps in the pathways that contribute to the development of normal immune responses and self-tolerance. Recent studies of autoimmune polyendocrinopathy syndrome type 1, autoimmune lymphoproliferative syndrome, immunodysregulation, polyendocrinopathy and enteropathy, X-linked, IL-2 receptor alpha-chain deficiency, and, in particular, their corresponding mouse models, have revealed the details of the molecular mechanisms of normal immune tolerance, and exposed how defects in these mechanisms result in human autoimmunity. In addition to a deeper understanding of the immune system, detailed molecular characterization of monogenic AIDs will help us to understand the mechanisms behind common polygenic AIDs and, furthermore, to develop novel therapies and intervention strategies to treat them.
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Affiliation(s)
- Ismo Ulmanen
- National Public Health Institute, Department of Molecular Medicine, Biomedicum, Helsinki, Finland
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32
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Ilmarinen T, Eskelin P, Halonen M, Rüppell T, Kilpikari R, Torres GD, Kangas H, Ulmanen I. Functional analysis of SAND mutations in AIRE supports dominant inheritance of the G228W mutation. Hum Mutat 2005; 26:322-31. [PMID: 16114041 DOI: 10.1002/humu.20224] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED) is a rare disorder caused by mutations in the autoimmune regulator gene (AIRE) and characterized by a variable combination of organ-specific autoimmune diseases. Studies on AIRE-deficient mice suggest that AIRE is an important factor in the establishment and maintenance of self-tolerance. The AIRE protein contains several structural domains often found in transcriptional regulators and functions as a transcriptional transactivator in vitro. To date, more than 50 patient mutations have been identified in the coding region of the AIRE gene. So far, APECED has been reported to be inherited in an autosomal recessive manner. However, in contrast to all other AIRE mutations, a novel mutation c.682T>G (p.G228W) in the DNA-binding and/or multimerization domain SAND was recently described to be inherited in a dominant fashion. We analyzed the effects of mutant AIRE proteins containing the patient mutations c.682T>G (p.G228W) and c.755C>T (p.P252L) located in the SAND domain on the properties of the wild-type AIRE in a heterozygous situation in vitro. In addition to the patient mutations, we analyzed the effects of a double mutation [c.727A>G;c.728A>C;c.739C>G;c740G>C] (p.K243A;R247A) of positively charged amino acids in the SAND domain. Of the mutants studied, only c.682T>G (p.G228W) mutant changed the subcellular localization and in addition severely disrupted the transactivating capacity of the wild-type AIRE. Our results indicate that the c.682T>G (p.G228W) mutant AIRE protein acts with a dominant negative effect by binding to the wild-type AIRE, thus preventing the protein from forming the complexes needed for transactivation.
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Affiliation(s)
- Tanja Ilmarinen
- Department of Molecular Medicine, National Public Health Institute, Helsinki, Finland.
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33
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Pereira LE, Bostik P, Ansari AA. The development of mouse APECED models provides new insight into the role of AIRE in immune regulation. Clin Dev Immunol 2005; 12:211-6. [PMID: 16295527 PMCID: PMC2275420 DOI: 10.1080/17402520500212589] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Autoimmune polyendocrinopathy candidiasis ectodermal dystrophy is a rare recessive autoimmune disorder caused by a defect in a single gene called AIRE (autoimmune regulator). Characteristics of this disease include a variable combination of autoimmune endocrine tissue destruction, mucocutaneous candidiasis and ectodermal dystrophies. The development of Aire-knockout mice has provided an invaluable model for the study of this disease. The aim of this review is to briefly highlight the strides made in APECED research using these transgenic murine models, with a focus on known roles of Aire in autoimmunity. The findings thus far are compelling and prompt additional areas of study which are discussed.
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Affiliation(s)
- Lara E Pereira
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, USA
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34
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Pitkänen J, Rebane A, Rowell J, Murumägi A, Ströbel P, Möll K, Saare M, Heikkilä J, Doucas V, Marx A, Peterson P. Cooperative activation of transcription by autoimmune regulator AIRE and CBP. Biochem Biophys Res Commun 2005; 333:944-53. [PMID: 15964547 DOI: 10.1016/j.bbrc.2005.05.187] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2005] [Accepted: 05/25/2005] [Indexed: 11/18/2022]
Abstract
Autoimmune regulator (AIRE) is a transcriptional regulator that is believed to control the expression of tissue-specific genes in the thymus. Mutated AIRE is responsible for onset of the hereditary autoimmune disease APECED. AIRE is able to form nuclear bodies (NBs) and interacts with the ubiquitous transcriptional coactivator CBP. In this paper, we show that CBP and AIRE synergistically activate transcription on different promoter reporters whereas AIRE gene mutation R257X, found in APECED patients, interferes with this coactivation effect. Furthermore, the overexpression of AIRE and CBP collaboratively enhance endogenous IFNbeta mRNA expression. The immunohistochemical studies suggest that CBP, depending on the balance of nuclear proteins, is a component of AIRE NBs. We also show that AIRE NBs are devoid of active chromatin and, therefore, not sites of transcription. In addition, we demonstrate by 3D analyses that AIRE and CBP, when colocalizing, are located spatially differently within AIRE NBs. In conclusion, our data suggest that AIRE activates transcription of the target genes, i.e., autoantigens in collaboration with CBP and that this activation occurs outside of AIRE NBs.
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Affiliation(s)
- J Pitkänen
- Institute of Medical Technology, University of Tampere and Tampere University Hospital, Tampere, Finland
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35
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Liston A, Lesage S, Gray DHD, Boyd RL, Goodnow CC. Genetic lesions in T-cell tolerance and thresholds for autoimmunity. Immunol Rev 2005; 204:87-101. [PMID: 15790352 DOI: 10.1111/j.0105-2896.2005.00253.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The cause of common organ-specific autoimmune diseases is poorly understood because of genetic and cellular complexity in humans and animals. Recent advances in the understanding of the mechanisms of the defects underlying autoimmune disease in autoimmune polyendocrinopathy syndrome type 1 and non-obese diabetic mice suggest that failures in central tolerance play a key role in predisposition towards organ-specific autoimmunity. The lessons from such rare monogenic autoimmune disorders and well-characterized polygenic traits demonstrate how subtle quantitative trait loci can result in large changes in the susceptibility to autoimmunity. These data allow us to propose a model relating efficiency of thymic deletion to T-cell tolerance and susceptibility to autoimmunity.
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Affiliation(s)
- Adrian Liston
- John Curtin School of Medical Research and The Australian Phenomics Facility, The Australian National University, Canberra, ACT 2601, Australia
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36
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Abstract
Mutations in the autoimmune regulator (AIRE) protein are the causative factor in development of the human disease autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED). In mice, the absence of the analogous protein aire influences ectopic expression of peripheral tissue antigens in thymic medullary epithelial cells (MECs), resulting in the development of an autoimmune disorder similar to APECED and establishing aire/AIRE as an important player in the induction of central tolerance. However, the molecular mechanism of AIRE's function, in particular its ability to specifically control the expression of peripheral tissue antigens in MECs, is still unclear. Here, we review current evidence relating to the molecular mechanism of AIRE.
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Affiliation(s)
- Jennifer Villaseñor
- Department of Medicine, Section on Immunology and Immunogenetics, Joslin Diabetes Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02215, USA
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37
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Bottomley MJ, Stier G, Pennacchini D, Legube G, Simon B, Akhtar A, Sattler M, Musco G. NMR structure of the first PHD finger of autoimmune regulator protein (AIRE1). Insights into autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) disease. J Biol Chem 2005; 280:11505-12. [PMID: 15649886 DOI: 10.1074/jbc.m413959200] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mutations in the autoimmune regulator protein AIRE1 cause a monogenic autosomal recessively inherited disease: autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED). AIRE1 is a multidomain protein that harbors two plant homeodomain (PHD)-type zinc fingers. The first PHD finger of AIRE1 is a mutational hot spot, to which several pathological point mutations have been mapped. Using heteronuclear NMR spectroscopy, we determined the solution structure of the first PHD finger of AIRE1 (AIRE1-PHD1), and characterized the peptide backbone mobility of the domain. We performed a conformational analysis of pathological AIRE1-PHD1 mutants that allowed us to rationalize the structural impact of APECED-causing mutations and to identify an interaction site with putative protein ligands of the AIRE1-PHD1 domain. The structure unequivocally exhibits the canonical PHD finger fold, with a highly conserved tryptophan buried inside the structure. The PHD finger is stabilized by two zinc ions coordinated in an interleaved (cross-brace) scheme. This zinc coordination resembles RING finger domains, which can function as E3 ligases in the ubiquitination pathway. Based on this fold similarity, it has been suggested that PHD fingers might also function as E3 ligases, although this hypothesis is controversial. At variance to a previous report, we could not find any evidence that AIRE1-PHD1 has an intrinsic E3 ubiquitin ligase activity, nor detect any direct interaction between AIRE1-PHD1 and its putative cognate E2. Consistently, we show that the AIRE1-PHD1 structure is clearly distinct from the RING finger fold. Our results point to a function of the AIRE1-PHD1 domain in protein-protein interactions, which is impaired in some APECED mutations.
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Affiliation(s)
- Matthew James Bottomley
- Istituto di Ricerche di Biologia Molecolare P. Angeletti, Via Pontina Km. 30.600, 00040 Pomezia (RM), Italy
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38
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Purohit S, Kumar PG, Laloraya M, She JX. Mapping DNA-binding domains of the autoimmune regulator protein. Biochem Biophys Res Commun 2005; 327:939-44. [PMID: 15649436 DOI: 10.1016/j.bbrc.2004.12.093] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2004] [Indexed: 11/23/2022]
Abstract
The human autoimmune regulator (AIRE) gene encodes a putative DNA-binding protein, which is mutated in patients affected by the autoimmune polyglandular syndrome type 1 or autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy. We have recently reported that AIRE can bind to two different DNA sequence motifs, suggesting the existence of at least two DNA-binding domains in the AIRE protein. By expressing a series of recombinant AIRE protein fragments, we demonstrate here that the two well-known plant homeodomains (PHD) domains in AIRE can bind to the ATTGGTTA sequence motif. The first ATTGGTTA-binding domain is mapped to amino acids 299-355 and the second ATTGGTTA-binding domain to amino acids 434-475. Furthermore, the SAND domain of AIRE is shown to bind to TTATTA motif. Results presented herein show that the residues at position 189-196 of AIRE (QRAVAMSS) are required for its binding to the TTATTA motif. The required sequence for DNA binding in the SAND domain of AIRE is remarkably different from other SAND-containing proteins such as Sp-100b and NUDR. Data presented in this paper indicate that the two PHD domains contained in AIRE, in addition to the SAND domain, can bind to specific DNA sequence motifs.
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Affiliation(s)
- Sharad Purohit
- Center for Biotechnology and Genomic Medicine, Medical College of Georgia, CA4095, Augusta, GA 30912, USA
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39
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Loraine AE, Helt GA, Cline MS, Siani-Rose MA. Exploring alternative transcript structure in the human genome using blocks and InterPro. J Bioinform Comput Biol 2005; 1:289-306. [PMID: 15290774 DOI: 10.1142/s0219720003000113] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2002] [Revised: 12/07/2002] [Accepted: 01/15/2003] [Indexed: 11/18/2022]
Abstract
Understanding how alternative splicing affects gene function is an important challenge facing modern-day molecular biology. Using homology-based, protein sequence analysis methods, it should be possible to investigate how transcript diversity impacts protein function. To test this, high-quality exon-intron structures were deduced for over 8000 human genes, including over 1300 (17 percent) that produce multiple transcript variants. A data mining technique (DiffMotif) was developed to identify genes in which transcript variation coincides with changes in conserved motifs between variants. Applying this method, we found that 30 percent of the multi-variant genes in our test set exhibited a differential profile of conserved InterPro and/or BLOCKS motifs across different mRNA variants. To investigate these, a visualization tool (ProtAnnot) that displays amino acid motifs in the context of genomic sequence was developed. Using this tool, genes revealed by the DiffMotif method were analyzed, and when possible, hypotheses regarding the potential role of alternative transcript structure in modulating gene function were developed. Examples of these, including: MEOX1, a homeobox-containing protein; AIRE, involved in auto-immune disease; PLAT, tissue type plasminogen activator; and CD79b, a component of the B-cell receptor complex, are presented. These results demonstrate that amino acid motif databases like BLOCKS and InterPro are useful tools for investigating how alternative transcript structure affects gene function.
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Affiliation(s)
- Ann E Loraine
- Bioinformatics Department, Affymetrix, 6550 Vallejo St, Emeryville, CA 94530 USA.
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40
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Abstract
Aire (autoimmune regulator), the gene responsible for the clinical disorder autoimmune polyendocrinopathy syndrome type I, has recently been identified as an important mediator of central tolerance. Aire upregulates the transcription of certain organ-specific self-antigens in medullary thymic epithelial cells, and has a role in the negative selection of organ-specific thymocytes. However, the molecular mechanisms by which Aire functions in these processes are still not well understood. Structural characteristics and biochemical data suggest that Aire might have a direct role in nuclear transcription and that it can function as an ubiquitin ligase. Although these molecular details await further characterization, the association of Aire with the prevention of autoimmunity highlights the importance of thymic mechanisms in the maintenance of tolerance.
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Affiliation(s)
- Maureen A Su
- Diabetes Center, University of California, San Francisco, Box 0540, 513 Parnassus Avenue, San Francisco, California 94143, USA
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41
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Zachou K, Rigopoulou E, Dalekos GN. Autoantibodies and autoantigens in autoimmune hepatitis: important tools in clinical practice and to study pathogenesis of the disease. JOURNAL OF AUTOIMMUNE DISEASES 2004; 1:2. [PMID: 15679907 PMCID: PMC544946 DOI: 10.1186/1740-2557-1-2] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2003] [Accepted: 10/15/2004] [Indexed: 02/08/2023]
Abstract
Autoimmune hepatitis (AIH) is a chronic necroinflammatory disease of the liver characterized by hypergammaglobulinemia, characteristic autoantibodies, association with HLA DR3 or DR4 and a favorable response to immunosuppressive treatment. The etiology is unknown. The detection of non-organ and liver-related autoantibodies remains the hallmark for the diagnosis of the disease in the absence of viral, metabolic, genetic, and toxic etiology of chronic hepatitis or hepatic injury. The current classification of AIH and the several autoantibodies/target-autoantigens found in this disease are reported. Current aspects on the significance of these markers in the differential diagnosis and the study of pathogenesis of AIH are also stated. AIH is subdivided into two major types; AIH type 1 (AIH-1) and type 2 (AIH-2). AIH-1 is characterized by the detection of smooth muscle autoantibodies (SMA) and/or antinuclear antibodies (ANA). Determination of antineutrophil cytoplasmic autoantibodies (ANCA), antibodies against the asialoglycoprotein receptor (anti-ASGP-R) and antibodies against to soluble liver antigens or liver-pancreas (anti-SLA/LP) may be useful for the identification of patients who are seronegative for ANA/SMA. AIH-2 is characterized by the presence of specific autoantibodies against liver and kidney microsomal antigens (anti-LKM type 1 or infrequently anti-LKM type 3) and/or autoantibodies against liver cytosol 1 antigen (anti-LC1). Anti-LKM-1 and anti-LKM-3 autoantibodies are also detected in some patients with chronic hepatitis C (HCV) and chronic hepatitis D (HDV). Cytochrome P450 2D6 (CYP2D6) has been documented as the major target-autoantigen of anti-LKM-1 autoantibodies in both AIH-2 and HCV infection. Recent convincing data demonstrated the expression of CYP2D6 on the surface of hepatocytes suggesting a pathogenetic role of anti-LKM-1 autoantibodies for the liver damage. Family 1 of UDP-glycuronosyltransferases has been identified as the target-autoantigen of anti-LKM-3. For these reasons the distinction between AIH and chronic viral hepatitis (especially of HCV) is of particular importance. Recently, the molecular target of anti-SLA/LP and anti-LC1 autoantibodies were identified as a 50 kDa UGA-suppressor tRNA-associated protein and a liver specific enzyme, the formiminotransferase cyclodeaminase, respectively. Anti-ASGP-R and anti-LC1 autoantibodies appear to correlate closely with disease severity and response to treatment suggesting a pathogenetic role of these autoantibodies for the hepatocellular injury. In general however, autoantibodies should not be used to monitor treatment, predict AIH activity or outcome. Finally, the current aspects on a specific form of AIH that may develop in some patients with a rare genetic syndrome, the autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome (APECED) are also given. Autoantibodies against liver microsomes (anti-LM) are the specific autoantibodies detected in AIH as a disease component of APECED but also in cases of dihydralazine-induced hepatitis. Cytochrome P450 1A2 has been identified as the target-autoantigen of anti-LM autoantibodies in both APECED-related AIH and dihydralazine-induced hepatitis. The latter may indicate that similar autoimmune pathogenetic mechanisms can lead to liver injury in susceptible individuals irrespective of the primary defect. Characterization of the autoantigen-autoantibody repertoire continues to be an attractive and important tool to get access to the correct diagnosis and to gain insight into the as yet unresolved mystery of how hepatic tolerance is given up and AIH ensues.
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Affiliation(s)
- Kalliopi Zachou
- Research Laboratory of Internal Medicine, Department of Medicine, Larissa Medical School, University of Thessaly, Larissa 41222, Greece
| | - Eirini Rigopoulou
- Academic Liver Unit, Department of Medicine, Larissa Medical School, University of Thessaly, Larissa 41222, Greece
| | - George N Dalekos
- Research Laboratory of Internal Medicine, Department of Medicine, Larissa Medical School, University of Thessaly, Larissa 41222, Greece
- Academic Liver Unit, Department of Medicine, Larissa Medical School, University of Thessaly, Larissa 41222, Greece
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42
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Sato K, Sato U, Tateishi S, Kubo K, Horikawa R, Mimura T, Yamamoto K, Kanda H. Aire downregulates multiple molecules that have contradicting immune-enhancing and immune-suppressive functions. Biochem Biophys Res Commun 2004; 318:935-40. [PMID: 15147962 DOI: 10.1016/j.bbrc.2004.04.116] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2004] [Indexed: 01/08/2023]
Abstract
Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a systemic disease with autoimmune characteristics caused by mutations in a single gene called AIRE. Although a defect in negative selection has been emphasized for the pathogenesis of the autoimmune symptoms on the basis of studies of Aire-targeted mice, the function of the gene in the peripheral immune system and the cause of immunodeficiency noted in the disease have not been clarified yet. In this study, we demonstrated using murine Aire transfectants that Aire downregulates IL-1 receptor antagonist (IL-1Ra), which is important for immune suppression, and major histocompatibility complex (MHC) class II molecules, which are critical for acquired immunity. It was surprising to learn that Aire, which has been supposed to positively regulate transcription, downregulates multiple molecules. This downregulation of IL-1Ra and MHC class II molecules seems to be caused by the competition for transcriptional coactivator, CREB-binding protein (CBP), and may explain part of the contradictory (i.e., both autoimmune and immunodeficient) nature of APECED.
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Affiliation(s)
- Kojiro Sato
- Department of Allergy and Rheumatology, Graduate School of Medicine and Faculty of Medicine, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-8655, Japan.
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Török HP, Tonenchi L, Glas J, Schiemann U, Folwaczny C. No significant association between mutations in exons 6 and 8 of the autoimmune regulator (AIRE) gene and inflammatory bowel disease. EUROPEAN JOURNAL OF IMMUNOGENETICS : OFFICIAL JOURNAL OF THE BRITISH SOCIETY FOR HISTOCOMPATIBILITY AND IMMUNOGENETICS 2004; 31:83-6. [PMID: 15086348 DOI: 10.1111/j.1365-2370.2004.00449.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Various autoantibodies have been described in patients with inflammatory bowel disease. The autoimmune regulator (AIRE) functions as a transcription factor in cells responsible for the induction and maintenance of immunological tolerance. In contrast to classic autoimmune disorders, polymorphisms of the AIRE gene are not associated with inflammatory bowel disease, despite the presence of disease-specific autoantibodies.
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Affiliation(s)
- H-P Török
- Medical Policlinic, University Hospital Immenstadt, Munich, Germany
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Peterson P, Pitkänen J, Sillanpää N, Krohn K. Autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED): a model disease to study molecular aspects of endocrine autoimmunity. Clin Exp Immunol 2004; 135:348-57. [PMID: 15008965 PMCID: PMC1808970 DOI: 10.1111/j.1365-2249.2004.02384.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/12/2003] [Indexed: 02/06/2023] Open
Affiliation(s)
- P Peterson
- Institute of Medical Technology and University Hospital, Tampere, Finland.
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Abstract
The autoimmune polyglandular syndrome type I (APSI) is an auto-somal recessive disorder that is characterized by chronic mucocutaneous candidiasis, multiple autoimmune endocrinopathies, and ectodermal dystrophies. The gene that is responsible for APSI has been identified as autoimmune regulator (AIRE). More than 50 different mutations have been discovered in patients who have APSI and the defects include nonsense and missense mutations, small insertions and deletions that lead to frameshift, and splice site mutations. The 545-amino acid protein that is encoded by AIRE contains several structural motifs that are suggestive of a transcriptional regulator. We provide an overview of the clinical and genetic features ofAPSI as well as the structure and functions of the AIRE protein.
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Affiliation(s)
- Qing-Guo Ruan
- Center for Biotechnology and Genomic Medicine, Medical College of Georgia, 1120 15th Street, Augusta, GA 30912-2400, USA
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46
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Halonen M, Kangas H, Rüppell T, Ilmarinen T, Ollila J, Kolmer M, Vihinen M, Palvimo J, Saarela J, Ulmanen I, Eskelin P. APECED-causing mutations in AIRE reveal the functional domains of the protein. Hum Mutat 2004; 23:245-57. [PMID: 14974083 DOI: 10.1002/humu.20003] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A defective form of the AIRE protein causes autoimmune destruction of target organs by disturbing the immunological tolerance of patients with a rare monogenic disease, autoimmune polyendocrinopathy (APE)-candidiasis (C)-ectodermal dystrophy (ED), APECED. Recently, experiments on knockout mice revealed that AIRE controls autoimmunity by regulating the transcription of peripheral tissue-restricted antigens in thymic medullary epithelial cells. Thus, AIRE provides a unique model for molecular studies of organ-specific autoimmunity. In order to analyze the molecular and cellular consequences of 16 disease-causing mutations in vitro, we studied the subcellular localization, transactivation capacity, homomultimerization, and complex formation of several mutant AIRE polypeptides. Most of the mutations altered the nucleus-cytoplasm distribution of AIRE and disturbed its association with nuclear dots and cytoplasmic filaments. While the PHD zinc fingers were necessary for the transactivation capacity of AIRE, other regions of AIRE also modulated this function. Consequently, most of the mutations decreased transactivation. The HSR domain was responsible for the homomultimerization activity of AIRE; all the missense mutations of the HSR and the SAND domains decreased this activity, but those in other domains did not. The AIRE protein was present in soluble high-molecular-weight complexes. Mutations in the HSR domain and deletion of PHD zinc fingers disturbed the formation of these complexes. In conclusion, we propose an in vitro model in which AIRE transactivates transcription through heteromeric molecular interactions that are regulated by homomultimerization and conditional localization of AIRE in the nucleus or in the cytoplasm.
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Affiliation(s)
- Maria Halonen
- Department of Molecular Medicine, National Public Health Institute, Helsinki, Finland.
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Harris M, Kecha O, Deal C, Howlett CR, Deiss D, Tobias V, Simoneau-Roy J, Walker J. Reversible metaphyseal dysplasia, a novel bone phenotype, in two unrelated children with autoimmunepolyendocrinopathy-candidiasis-ectodermal dystrophy: clinical and molecular studies. J Clin Endocrinol Metab 2003; 88:4576-85. [PMID: 14557425 DOI: 10.1210/jc.2003-030089] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
We report the association of an undescribed, reversible metaphyseal dysplasia (RMD) with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) in two patients, one homozygous and one heterozygous for a 13-bp deletion in exon 8 of the autoimmune regulator (AIRE) gene. One patient also had a novel deletion in exon 6, resulting in a frameshift mutation and introduction of a STOP codon in exon 10. Their APECED phenotypes differed, but both patients developed progressive skeletal deformities and growth failure from early childhood. Radiological examination suggested a generalized abnormality of endochondral ossification, with irregular, flared, radioopaque regions in the metaphyses, subjacent to the growth plates. Histopathology in patient 1 showed islands of calcified cartilage within bone, consistent with impaired coupling of cartilage resorption with vascular invasion and ossification. Despite discordance for puberty, both patients experienced radiological resolution of their bone disease in their mid-teens, with improvement in histopathology in patient 1. RMD may constitute a rare phenotypic variation of APECED, possibly resulting from autoimmunity directed against skeletal proteins. We also demonstrated AIRE expression in chondrocytes derived from human fetal growth plates, primary culture of human chondrocytes, and two chondrosarcoma cell lines, suggesting a potential role for abnormal AIRE expression in the development of RMD.
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Affiliation(s)
- Mark Harris
- Department of Endocrinology, Sydney Children's Hospital, Randwick, New South Wales 2031, Australia
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48
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Strassburg CP, Manns MP. Transition of care between paediatric and adult gastroenterology. Autoimmune hepatitis. Best Pract Res Clin Gastroenterol 2003; 17:291-306. [PMID: 12676120 DOI: 10.1016/s1521-6918(03)00015-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Autoimmune hepatitis (AIH) is a rare chronic disease of the liver with an excellent prognosis under medical therapy capable of reaching complete remission. The diagnosis of AIH relies on the exclusion of viral, metabolic, genetic and toxic aetiologies of chronic hepatitis, or hepatic injury. Autoantibodies contribute to the diagnosis of AIH and have led to the serological subclassification into three distinct types. Also, immunogenetic associations suggest heterogeneity of the syndrome of AIH. Treatment is not based on serological types but is uniformly employed for all subtypes of AIH. Although 90% of patients respond to treatment, immunosuppressive drugs used in transplant medicine have been employed for patients with treatment failure. New drugs, such as budenoside, are being evaluated for the long-term treatment of AIH with a reduction in steroid side-effects. Liver transplantation is an established treatment option for patients who fail to reach remission and progress to cirrhosis and liver failure. In Europe, about 4% of cirrhotic patients with the diagnosis of AIH undergo transplantation. The diagnosis and awareness of the disease is designed to reduce mortality and morbidity.
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Affiliation(s)
- Christian P Strassburg
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Carl Neuberg Str. 1, 30625 Hannover, Germany
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49
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Abstract
The autoimmune regulator (AIRE) is a gene where mutations cause the recessively inherited disorder called autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) or autoimmune polyendocrinopathy syndrome type 1 (APS1). Variable combinations of autoimmune endocrine diseases such as Addison's disease, hypoparathyroidism, and type 1 diabetes characterize APECED. The AIRE protein has several domains indicative of a transcriptional regulator. AIRE contains two PHD (plant homeodomain) type zinc fingers, four nuclear receptor binding LXXLL motifs, a putative DNA-binding domain named SAND and, in addition, a highly conserved N-terminal domain similar to the homogenously staining region domain of the Sp100 protein. At the subcellular level, AIRE is expressed in nuclear dots resembling promyelocytic leukemia nuclear bodies, which are associated with several transcriptionally active proteins. AIRE is primarily expressed in thymic medullary epithelial cells and monocyte-dendritic cells in the thymus but also in a rare subset of cells in the lymph nodes, spleen and fetal liver. The disease, caused by mutations in AIRE, its function as a protein involved in transcription, and its restricted expression in cells important in negative selection, all together suggest that AIRE is a central protein in the maintenance of immune tolerance. In this review of the recent literature we discuss the results of these studies with particular attention on the AIRE expression pattern and its function as a transcriptional regulator, as well as the effects of patient mutations on the molecular characteristics of the protein.
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Affiliation(s)
- J Pitkänen
- Institute of Medical Technology, University of Tampere and Tampere Hospital, Finland
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Lappalainen I, Vihinen M. Structural basis of ICF-causing mutations in the methyltransferase domain of DNMT3B. Protein Eng Des Sel 2002; 15:1005-14. [PMID: 12601140 DOI: 10.1093/protein/15.12.1005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Mutations in the gene encoding for a de novo methyltransferase, DNMT3B, lead to an autosomal recessive Immunodeficiency, Centromeric instability and Facial anomalies (ICF) syndrome. To analyse the protein structure and consequences of ICF-causing mutations, we modelled the structure of the DNMT3B methyltransferase domain based on Haemophilus haemolyticus protein in complex with the cofactor AdoMet and the target DNA sequence. The structural model has a two-subdomain fold where the DNA-binding region is situated between the subdomains on a surface cleft having positive electrostatic potential. The smaller subdomains of the methyltransferases differ in length and sequences and therefore only the target recognition domain loop was modelled to show the location of an ICF-causing mutation. Based on the model, the DNMT3B recognizes the GC sequence and flips the cytosine from the double-stranded DNA to the catalytic pocket. The amino acids in the cofactor and target cytosine binding sites and also the electrostatic properties of the binding pockets are conserved. In addition, a registry of all known ICF-causing mutations, DNMT3Bbase, was constructed. The structural principles of the pathogenic mutations based on the modelled structure and the analysis of chi angle rotation changes of mutated side chains are discussed.
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Affiliation(s)
- Ilkka Lappalainen
- Institute of Medical Technology, FIN-33014 University of Tampere, Tampere, Finland
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