1
|
Li K, Ouyang Y, Yang H. Myasthenia gravis and five autoimmune diseases: a bidirectional Mendelian randomization study. Neurol Sci 2024; 45:1699-1706. [PMID: 37910321 DOI: 10.1007/s10072-023-07163-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 10/18/2023] [Indexed: 11/03/2023]
Abstract
BACKGROUND The association between myasthenia gravis (MG) and other autoimmune diseases is well established. In this study, we aimed to investigate the causal effects between MG and five other autoimmune diseases, including autoimmune thyroid disease (AITD), multiple sclerosis (MS), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and type 1 diabetes (T1DM). METHODS We conducted a bidirectional Mendelian randomization (MR) study by using seven published genome-wide association studies (GWAS), including MG (1873 patients versus 36,370 controls), AITD (autoimmune hypothyroidism) (22,997 patients versus 175,475 controls), AITD (autoimmune hyperthyroidism) (962 patients versus 172,976 controls), MS (47,429 patients versus 68,374 controls), RA (14,361 patients versus 43,923 controls), SLE (4222 patients versus 8431 controls), and T1DM (9266 patients versus 15,574 controls). We used the inverse-variance-weighted (IVW) method, weighted-median (WM) estimator, MR-Egger regression, and MR PRESSO in our analyses. We also carried out detailed sensitivity analyses for each direction using the aforementioned methods. RESULTS When MG was treated as the exposure, MR evidence suggested a causal relationship between MG and T1DM, SLE, AITD (both hypothyroidism and hyperthyroidism), and MS (excluding RA). Using the IVW method, we found that MG was associated with increased risk of T1DM (OR = 1.94; 95% CI, 1.16-3.26; p = 0.012), SLE (OR = 1.47; 95% CI, 1.02-2.13; p = 0.04), AITD (hypothyroidism) (OR = 1.31; 95% CI, 1.02-1.68; p = 0.039), AITD (hyperthyroidism) (OR = 1.55; 95% CI, 1.15-2.09; p = 0.004), and MS (OR = 1.46; 95% CI, 1.01-2.09; p = 0.041). When MG was treated as the outcome, MR evidence suggested that RA, T1DM, and SLE were causal factors in MG. Using the IVW method, we found that the risk of MG increased with exposure to RA (OR = 1.21; 95% CI, 1.08-1.37; p = 0.002), T1DM (OR = 1.09; 95% CI, 1.02-1.16; p = 0.006), and SLE (OR = 1.12; 95% CI, 1.02-1.23; p = 0.018). CONCLUSIONS This study demonstrated a causal relationship between MG and several other autoimmune diseases. Our results supported a bidirectional causal association between MG and SLE/T1DM. Our findings also provided reliable evidence that MG is associated with increased risk of AITD. Meanwhile, we also showed that RA is a possible causal driver of MG risk.
Collapse
Affiliation(s)
- Kailin Li
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, 410013, China
| | - Yuzhen Ouyang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, 410013, China
| | - Huan Yang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, 410013, China.
| |
Collapse
|
2
|
Lalunio H, Parker L, Hanson ED, Gregorevic P, Levinger I, Hayes A, Goodman CA. Detecting the vitamin D receptor (VDR) protein in mouse and human skeletal muscle: Strain-specific, species-specific and inter-individual variation. Mol Cell Endocrinol 2023; 578:112050. [PMID: 37683909 DOI: 10.1016/j.mce.2023.112050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/27/2023] [Accepted: 08/29/2023] [Indexed: 09/10/2023]
Abstract
Vitamin D, and its receptor (VDR), play roles in muscle development/function, however, VDR detection in muscle has been controversial. Using different sample preparation methods and antibodies, we examined differences in muscle VDR protein abundance between two mouse strains and between mice and humans. The mouse D-6 VDR antibody was not reliable for detecting VDR in mouse muscle, but was suitable for human muscle, while the rabbit D2K6W antibody was valid for mouse and human muscle. VDR protein was generally lower in muscles from C57 B l/6 than FVB/N mice and was higher in human than mouse muscle. Two putative VDR bands were detected in human muscle, possibly representing VDR isoforms/splice variants, with marked inter-individual differences. This study provides new information on detecting VDR in muscle and on inter-mouse strain and inter-human individual differences in VDR expression. These findings may have implications for future pre-clinical and clinical studies and prompt further investigation to confirm possible VDR isoforms in human muscle.
Collapse
Affiliation(s)
- Hannah Lalunio
- Department of Medicine, The University of Melbourne, Parkville, Victoria, Australia; Australian Institute for Musculoskeletal Science (AIMSS), Victoria University, St. Albans, Victoria, Australia
| | - Lewan Parker
- Institute for Physical Activity and Nutrition (IPAN), Deakin University, Geelong, VIC, Australia
| | - Erik D Hanson
- Department of Exercise and Sport Science, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Institute for Health and Sport (iHeS), Victoria University, Melbourne, Victoria, Australia
| | - Paul Gregorevic
- Department of Anatomy and Physiology, The University of Melbourne, Parkville, Victoria, Australia; Centre for Muscle Research, The University of Melbourne, Parkville, Victoria, Australia; Department of Neurology, The University of Washington School of Medicine, Seattle, WA, USA; Department of Biochemistry and Molecular Biology, Monash University, VIC, Australia
| | - Itamar Levinger
- Australian Institute for Musculoskeletal Science (AIMSS), Victoria University, St. Albans, Victoria, Australia; Institute for Health and Sport (iHeS), Victoria University, Melbourne, Victoria, Australia
| | - Alan Hayes
- Department of Medicine, The University of Melbourne, Parkville, Victoria, Australia; Australian Institute for Musculoskeletal Science (AIMSS), Victoria University, St. Albans, Victoria, Australia; Institute for Health and Sport (iHeS), Victoria University, Melbourne, Victoria, Australia
| | - Craig A Goodman
- Australian Institute for Musculoskeletal Science (AIMSS), Victoria University, St. Albans, Victoria, Australia; Department of Anatomy and Physiology, The University of Melbourne, Parkville, Victoria, Australia; Centre for Muscle Research, The University of Melbourne, Parkville, Victoria, Australia; Institute for Health and Sport (iHeS), Victoria University, Melbourne, Victoria, Australia.
| |
Collapse
|
3
|
Naorem LD, Pathak E, Muthaiyan M, Venkatesan A. Network-based meta-analysis for the identification of potential target for human anaplastic thyroid carcinoma. Meta Gene 2020. [DOI: 10.1016/j.mgene.2020.100690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
|
4
|
Activation-induced cell death of self-reactive regulatory T cells drives autoimmunity. Proc Natl Acad Sci U S A 2019; 116:26788-26797. [PMID: 31818938 DOI: 10.1073/pnas.1910281116] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Activation of self-reactive T cells is a major driver to autoimmunity and is suppressed by mechanisms of regulation. In a humanized model of autoimmune thyroiditis, we investigated the mechanism underlying break of tolerance. Here, we found that a human TCR specific for the self-antigen thyroid peroxidase (TPO) is positively selected in the thymus of RAG KO mice on both T effector (Teff) and T regulatory (Treg) CD4+Foxp3+ cells. In vivo Teff are present in all immune organs, whereas the TPO-specific Treg are present in all lymphoid organs with the exception of the thyroid-draining lymph nodes. We suggest that the presence of TPO in the thyroid draining lymph nodes induces the activation of Teff and the depletion of Treg via activation-induced cell death (AICD). Our findings provide insights on the failure of the mechanisms of immune tolerance, with potential implications in designing immunotherapeutic strategies.
Collapse
|
5
|
McLachlan SM, Rapoport B. A transgenic mouse that spontaneously develops pathogenic TSH receptor antibodies will facilitate study of antigen-specific immunotherapy for human Graves' disease. Endocrine 2019; 66:137-148. [PMID: 31560118 DOI: 10.1007/s12020-019-02083-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Accepted: 09/04/2019] [Indexed: 12/13/2022]
Abstract
Graves' hyperthyroidism can be treated but not cured. Antigen-specific immunotherapy would accomplish this goal, for which purpose an animal model is an invaluable tool. Two types of animal models are available. First, pathogenic TSHR antibodies (TSHRAb) can be induced by injecting mice with fibroblasts co-expressing the human TSHR (hTSHR) and MHC class II, or in mammals using plasmid or adenovirus vectors encoding the hTSHR or its A-subunit. Second, a mouse model that spontaneously develops pathogenic TSHRAb resembling those in human disease was recently described. This outcome was accomplished by transgenic intrathyroidal expression of the hTSHR A-subunit in NOD.H2h4 mice that are genetically predisposed to develop thyroiditis but, without the transgene, do not generate TSHRAb. Recently, novel approaches to antigen-specific immunotherapy have been tested, primarily in the induced model, by injecting TSHR A-subunit protein or cyclic TSHR peptides. T-cell tolerance has also been induced in "humanized" HLA-DR3 mice by injecting synthetic peptides predicted in silico to mimic naturally processed TSHR T-cell epitopes. Indeed, a phase 1 study based on the latter approach has been conducted in humans. In the spontaneous model (hTSHR/NOD.H2h mice), injection of soluble or nanoparticle-bearing hTSHR A-subunits had the unwanted effect of exacerbating pathogenic TSHRAb levels. A promising avenue for tolerance induction, successful in other conditions and yet to be tested with the TSHR, involves encapsulating the antigen. In conclusion, these studies provide insight into the potential outcome of immunotherapeutic approaches and emphasize the importance of a spontaneous model to test future novel, antigen-specific immunotherapies for Graves' disease.
Collapse
Affiliation(s)
- Sandra M McLachlan
- Department of Medicine, University of California Los Angeles, 100 Medical Plaza Driveway, Los Angeles, CA, 90095, USA
| | - Basil Rapoport
- Department of Medicine, University of California Los Angeles, 100 Medical Plaza Driveway, Los Angeles, CA, 90095, USA.
| |
Collapse
|
6
|
Lin JD, Fang WF, Tang KT, Cheng CW. Effects of exogenous melatonin on clinical and pathological features of a human thyroglobulin-induced experimental autoimmune thyroiditis mouse model. Sci Rep 2019; 9:5886. [PMID: 30971749 PMCID: PMC6458129 DOI: 10.1038/s41598-019-42442-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 03/28/2019] [Indexed: 12/22/2022] Open
Abstract
Melatonin (MLT) plays a significant role in both innate and adaptive immunity, and dysregulation of the MLT signature can modify autoimmune disease phenotypes. In this study, the influence of exogenous MLT administration on regulating autoimmune thyroiditis animal models was evaluated. An experimental autoimmune thyroiditis model was established in MLT-synthesizing (CBA) and MLT-deficient (C57BL/6) mice by immunization with human thyroidglobulin (TG), which features thyrotoxicosis, thyrocyte damage, and CD3+ T cell infiltration. In TG-immunized CBA mice, exogenous MLT administration in drinking water (6 μg/ml) enhanced thyroiditis and increased TG-specific splenocyte proliferation but not the anti-thyroglobulin antibody (ATA) titer, while MLT alone caused no significant alteration in thyroid function or histopathology. Meanwhile, MLT administration did not modify thyroid function, the ATA titer, or the thyroid histopathology, but results showed an increase in the splenocyte proliferative capacity in TG-immunized C57BL/6 mice. Collectively, our data showed that early exogenous MLT modified the progression of autoimmune thyroiditis through T cell-driven immunity, and excess MLT worsened the clinical and pathological features.
Collapse
Affiliation(s)
- Jiunn-Diann Lin
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Division of Endocrinology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan.,Division of Endocrinology and Metabolism, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Wen-Fang Fang
- Department of Family Medicine, Shuang Ho Hospital, New Taipei City, Taiwan
| | - Kam-Tsun Tang
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Veterans General Hospital, Taipei, Taiwan
| | - Chao-Wen Cheng
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan. .,Traditional Herb Medicine Research Center, Taipei Medical University Hospital, Taipei Medical University, Taipei, Taiwan. .,Cell Physiology and Molecular Image Research Center, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.
| |
Collapse
|
7
|
Ząbczyńska M, Kozłowska K, Pocheć E. Glycosylation in the Thyroid Gland: Vital Aspects of Glycoprotein Function in Thyrocyte Physiology and Thyroid Disorders. Int J Mol Sci 2018; 19:E2792. [PMID: 30227620 PMCID: PMC6163523 DOI: 10.3390/ijms19092792] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 09/07/2018] [Accepted: 09/14/2018] [Indexed: 02/08/2023] Open
Abstract
The key proteins responsible for hormone synthesis in the thyroid are glycosylated. Oligosaccharides strongly affect the function of glycosylated proteins. Both thyroid-stimulating hormone (TSH) secreted by the pituitary gland and TSH receptors on the surface of thyrocytes contain N-glycans, which are crucial to their proper activity. Thyroglobulin (Tg), the protein backbone for synthesis of thyroid hormones, is a heavily N-glycosylated protein, containing 20 putative N-glycosylated sites. N-oligosaccharides play a role in Tg transport into the follicular lumen, where thyroid hormones are produced, and into thyrocytes, where hyposialylated Tg is degraded. N-glycans of the cell membrane transporters sodium/iodide symporter and pendrin are necessary for iodide transport. Some changes in glycosylation result in abnormal activity of the thyroid and alteration of the metabolic clearance rate of hormones. Alteration of glycan structures is a pathological process related to the progression of chronic diseases such as thyroid cancers and autoimmunity. Thyroid carcinogenesis is accompanied by changes in sialylation and fucosylation, β1,6-branching of glycans, the content and structure of poly-LacNAc chains, as well as O-GlcNAcylation, while in thyroid autoimmunity the main processes affected are sialylation and fucosylation. The glycobiology of the thyroid gland is an intensively studied field of research, providing new data helpful in understanding the role of the sugar component in thyroid protein biology and disorders.
Collapse
Affiliation(s)
- Marta Ząbczyńska
- Department of Glycoconjugate Biochemistry, Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387 Kraków, Poland.
| | - Kamila Kozłowska
- Department of Glycoconjugate Biochemistry, Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387 Kraków, Poland.
| | - Ewa Pocheć
- Department of Glycoconjugate Biochemistry, Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387 Kraków, Poland.
| |
Collapse
|
8
|
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.
Collapse
Affiliation(s)
- Roberto Perniola
- Department of Pediatrics, Neonatal Intensive Care, Vito Fazzi Regional Hospital, Lecce, Italy
| |
Collapse
|
9
|
Schlüter A, Horstmann M, Diaz-Cano S, Plöhn S, Stähr K, Mattheis S, Oeverhaus M, Lang S, Flögel U, Berchner-Pfannschmidt U, Eckstein A, Banga JP. Genetic immunization with mouse thyrotrophin hormone receptor plasmid breaks self-tolerance for a murine model of autoimmune thyroid disease and Graves' orbitopathy. Clin Exp Immunol 2017; 191:255-267. [PMID: 29058307 DOI: 10.1111/cei.13075] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/20/2017] [Indexed: 01/08/2023] Open
Abstract
Experimental models of Graves' hyperthyroid disease accompanied by Graves' orbitopathy (GO) can be induced efficiently in susceptible inbred strains of mice by immunization by electroporation of heterologous human TSH receptor (TSHR) A-subunit plasmid. In this study, we report on the development of a bona fide murine model of autoimmune Graves' disease induced with homologous mouse TSHR A-subunit plasmid. Autoimmune thyroid disease in the self-antigen model was accompanied by GO and characterized by histopathology of hyperplastic glands with large thyroid follicular cells. Examination of orbital tissues showed significant inflammation in extra-ocular muscle with accumulation of T cells and macrophages together with substantial deposition of adipose tissue. Notably, increased levels of brown adipose tissue were present in the orbital tissue of animals undergoing experimental GO. Further analysis of inflammatory loci by 19 F-magnetic resonance imaging showed inflammation to be confined to orbital muscle and optic nerve, but orbital fat showed no difference in inflammatory signs in comparison to control β-Gal-immunized animals. Pathogenic antibodies induced to mouse TSHR were specific for the self-antigen, with minimal cross-reactivity to human TSHR. Moreover, compared to other self-antigen models of murine Graves' disease induced in TSHR knock-out mice, the repertoire of autoantibodies to mouse TSHR generated following the breakdown of thymic self-tolerance is different to those that arise when tolerance is not breached immunologically, as in the knock-out models. Overall, we show that mouse TSHR A-subunit plasmid immunization by electroporation overcomes tolerance to self-antigen to provide a faithful model of Graves' disease and GO.
Collapse
Affiliation(s)
- A Schlüter
- Molecular Ophthalmology, Departments of Ophthalmology University Hospital Essen, Germany.,Oto-Rhino-Laryngology, Head and Neck Surgery, University Hospital Essen, Essen, Germany
| | - M Horstmann
- Molecular Ophthalmology, Departments of Ophthalmology University Hospital Essen, Germany
| | - S Diaz-Cano
- Department of Histopathology, King's College Hospital NHS, London, UK
| | - S Plöhn
- Molecular Ophthalmology, Departments of Ophthalmology University Hospital Essen, Germany
| | - K Stähr
- Oto-Rhino-Laryngology, Head and Neck Surgery, University Hospital Essen, Essen, Germany
| | - S Mattheis
- Oto-Rhino-Laryngology, Head and Neck Surgery, University Hospital Essen, Essen, Germany
| | - M Oeverhaus
- Department of Ophthalmology, University Hospital Essen, Essen, Germany
| | - S Lang
- Oto-Rhino-Laryngology, Head and Neck Surgery, University Hospital Essen, Essen, Germany
| | - U Flögel
- Experimental Cardiovascular Imaging, Department of Molecular Cardiology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | | | - A Eckstein
- Molecular Ophthalmology, Departments of Ophthalmology University Hospital Essen, Germany.,Department of Ophthalmology, University Hospital Essen, Essen, Germany
| | - J P Banga
- Molecular Ophthalmology, Departments of Ophthalmology University Hospital Essen, Germany
| |
Collapse
|
10
|
McLachlan SM, Lesage S, Collin R, Banuelos B, Aliesky HA, Rapoport B. Genes Outside the Major Histocompatibility Complex Locus Are Linked to the Development of Thyroid Autoantibodies and Thyroiditis in NOD.H2h4 Mice. Endocrinology 2017; 158:702-713. [PMID: 28323998 PMCID: PMC5460802 DOI: 10.1210/en.2016-1875] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 01/11/2017] [Indexed: 12/13/2022]
Abstract
Thyroiditis and autoantibodies to thyroglobulin (TgAb) and thyroid peroxidase (TPOAb) develop spontaneously in NOD.H2h4 mice, a phenotype enhanced by dietary iodine. NOD.H2h4 mice were derived by introducing the major histocompatibility class (MHC) molecule I-Ak from B10.A(4R) mice to nonobese diabetic (NOD) mice. Apart from I-Ak, the genes responsible for the NOD.H2h4 phenotype are unknown. Extending serendipitous observations from crossing BALB/c to NOD.H2h4 mice, thyroid autoimmunity was investigated in both genders of the F1, F2, and the second-generation backcross of F1 to NOD.H2h4 (N2). Medium-density linkage analysis was performed on thyroid autoimmunity traits in F2 and N2 progeny. TgAb develop before TPOAb and were measured after 8 and 16 weeks of iodide exposure; TPOAb and thyroiditis were studied at 16 weeks. TgAb, TPOAb, and thyroiditis, absent in BALB/c and F1 mice, developed in most NOD.H2h4 and in more N2 than F2 progeny. No linkages were observed in F2 progeny, probably because of the small number of autoantibody-positive mice. In N2 progeny (equal numbers of males and females), a chromosome 17 locus is linked to thyroiditis and TgAb and is suggestively linked to TPOAb. This locus includes MHC region genes from B10.A(4R) mice (such as I-Ak and Tnf, the latter involved in thyrocyte apoptosis) and genes from NOD mice such as Satb1, which most likely plays a role in immune tolerance. In conclusion, MHC and non-MHC genes, encoded within the chromosome 17 locus from both B10.A(4R) and NOD strains, are most likely responsible for the Hashimoto disease-like phenotype of NOD.H2h4 mice.
Collapse
Affiliation(s)
- Sandra M. McLachlan
- Thyroid Autoimmune Disease Unit, Cedars-Sinai Medical Center, Los Angeles, California 90048
- University of California, Los Angeles, School of Medicine, Los Angeles, California 90095
| | - Sylvie Lesage
- Department of Immunology-Oncology, Maisonneuve-Rosemont Hospital, Montréal, Québec H1T 2M4, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Roxanne Collin
- Department of Immunology-Oncology, Maisonneuve-Rosemont Hospital, Montréal, Québec H1T 2M4, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Bianca Banuelos
- Thyroid Autoimmune Disease Unit, Cedars-Sinai Medical Center, Los Angeles, California 90048
- University of California, Los Angeles, School of Medicine, Los Angeles, California 90095
| | - Holly A. Aliesky
- Thyroid Autoimmune Disease Unit, Cedars-Sinai Medical Center, Los Angeles, California 90048
- University of California, Los Angeles, School of Medicine, Los Angeles, California 90095
| | - Basil Rapoport
- Thyroid Autoimmune Disease Unit, Cedars-Sinai Medical Center, Los Angeles, California 90048
- University of California, Los Angeles, School of Medicine, Los Angeles, California 90095
| |
Collapse
|
11
|
McLachlan SM, Aliesky HA, Banuelos B, Lesage S, Collin R, Rapoport B. High-level intrathymic thyrotrophin receptor expression in thyroiditis-prone mice protects against the spontaneous generation of pathogenic thyrotrophin receptor autoantibodies. Clin Exp Immunol 2017; 188:243-253. [PMID: 28099999 PMCID: PMC5383439 DOI: 10.1111/cei.12928] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 01/03/2017] [Accepted: 01/12/2017] [Indexed: 12/11/2022] Open
Abstract
The thyrotrophin receptor (TSHR) A-subunit is the autoantigen targeted by pathogenic autoantibodies that cause Graves' hyperthyroidism, a common autoimmune disease in humans. Previously, we reported that pathogenic TSHR antibodies develop spontaneously in thyroiditis-susceptible non-obese diabetic (NOD).H2h4 mice bearing a human TSHR A-subunit transgene, which is expressed at low levels in both the thyroid and thymus (Lo-expressor transgene). The present study tested recent evidence that high intrathymic TSHR expression protects against the development of pathogenic TSHR antibodies in humans. By successive back-crossing, we transferred to the NOD.H2h4 background a human TSHR A-subunit transgene expressed at high levels in the thyroid and thymus (Hi-expressor transgene). In the sixth back-cross generation (> 98% NOD.H2h4 genome), only transgenic offspring produced spontaneously immunoglobulin (Ig)G class non-pathogenic human TSHR A-subunit antibodies. In contrast, both transgenic and non-transgenic offspring developed antibodies to thyroglobulin and thyroid peroxidase. However, non-pathogenic human TSHR antibody levels in Hi-expressor offspring were lower than in Lo-expressor transgenic mice. Moreover, pathogenic TSHR antibodies, detected by inhibition of TSH binding to the TSHR, only developed in back-cross offspring bearing the Lo-expressor, but not the Hi-expressor, transgene. High versus low expression human TSHR A-subunit in the NOD.H2h4 thymus was not explained by the transgene locations, namely chromosome 2 (127-147 Mb; Hi-expressor) and chromosome 1 (22.9-39.3 Mb; low expressor). Nevertheless, using thyroiditis-prone NOD.H2h4 mice and two transgenic lines, our data support the association from human studies that low intrathymic TSHR expression is associated with susceptibility to developing pathogenic TSHR antibodies, while high intrathymic TSHR expression is protective.
Collapse
Affiliation(s)
- S M McLachlan
- Thyroid Autoimmune Disease Unit, Cedars-Sinai Research Institute and UCLA School of Medicine, University of California, Los Angeles, CA, USA
| | - H A Aliesky
- Thyroid Autoimmune Disease Unit, Cedars-Sinai Research Institute and UCLA School of Medicine, University of California, Los Angeles, CA, USA
| | - B Banuelos
- Thyroid Autoimmune Disease Unit, Cedars-Sinai Research Institute and UCLA School of Medicine, University of California, Los Angeles, CA, USA
| | - S Lesage
- Department of Immunology-Oncology, Maisonneuve-Rosemont Hospital, Montréal, Québec, Canada and Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
| | - R Collin
- Department of Immunology-Oncology, Maisonneuve-Rosemont Hospital, Montréal, Québec, Canada and Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
| | - B Rapoport
- Thyroid Autoimmune Disease Unit, Cedars-Sinai Research Institute and UCLA School of Medicine, University of California, Los Angeles, CA, USA
| |
Collapse
|
12
|
Rapoport B, Banuelos B, Aliesky HA, Hartwig Trier N, McLachlan SM. Critical Differences between Induced and Spontaneous Mouse Models of Graves' Disease with Implications for Antigen-Specific Immunotherapy in Humans. THE JOURNAL OF IMMUNOLOGY 2016; 197:4560-4568. [PMID: 27913646 DOI: 10.4049/jimmunol.1601393] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 10/14/2016] [Indexed: 01/20/2023]
Abstract
Graves' hyperthyroidism, a common autoimmune disease caused by pathogenic autoantibodies to the thyrotropin (TSH) receptor (TSHR), can be treated but not cured. This single autoantigenic target makes Graves' disease a prime candidate for Ag-specific immunotherapy. Previously, in an induced mouse model, injecting TSHR A-subunit protein attenuated hyperthyroidism by diverting pathogenic TSHR Abs to a nonfunctional variety. In this study, we explored the possibility of a similar diversion in a mouse model that spontaneously develops pathogenic TSHR autoantibodies, NOD.H2h4 mice with the human (h) TSHR (hTSHR) A-subunit transgene expressed in the thyroid and (shown in this article) the thymus. We hypothesized that such diversion would occur after injection of "inactive" hTSHR A-subunit protein recognized only by nonpathogenic (not pathogenic) TSHR Abs. Surprisingly, rather than attenuating the pre-existing pathogenic TSHR level, in TSHR/NOD.H2h4 mice inactive hTSHR Ag injected without adjuvant enhanced the levels of pathogenic TSH-binding inhibition and thyroid-stimulating Abs, as well as nonpathogenic Abs detected by ELISA. This effect was TSHR specific because spontaneously occurring autoantibodies to thyroglobulin and thyroid peroxidase were unaffected. As controls, nontransgenic NOD.H2h4 mice similarly injected with inactive hTSHR A-subunit protein unexpectedly developed TSHR Abs, but only of the nonpathogenic variety detected by ELISA. Our observations highlight critical differences between induced and spontaneous mouse models of Graves' disease with implications for potential immunotherapy in humans. In hTSHR/NOD.H2h4 mice with ongoing disease, injecting inactive hTSHR A-subunit protein fails to divert the autoantibody response to a nonpathogenic form. Indeed, such therapy is likely to enhance pathogenic Ab production and exacerbate Graves' disease in humans.
Collapse
Affiliation(s)
- Basil Rapoport
- Thyroid Autoimmune Disease Unit, Cedars-Sinai Medical Center and UCLA School of Medicine, Los Angeles, CA 90048; and
| | - Bianca Banuelos
- Thyroid Autoimmune Disease Unit, Cedars-Sinai Medical Center and UCLA School of Medicine, Los Angeles, CA 90048; and
| | - Holly A Aliesky
- Thyroid Autoimmune Disease Unit, Cedars-Sinai Medical Center and UCLA School of Medicine, Los Angeles, CA 90048; and
| | - Nicole Hartwig Trier
- Department of Autoimmunology and Biomarkers, Statens Serum Institut, DK-2300 Copenhagen S, Denmark
| | - Sandra M McLachlan
- Thyroid Autoimmune Disease Unit, Cedars-Sinai Medical Center and UCLA School of Medicine, Los Angeles, CA 90048; and
| |
Collapse
|
13
|
Dragin N, Bismuth J, Cizeron-Clairac G, Biferi MG, Berthault C, Serraf A, Nottin R, Klatzmann D, Cumano A, Barkats M, Le Panse R, Berrih-Aknin S. Estrogen-mediated downregulation of AIRE influences sexual dimorphism in autoimmune diseases. J Clin Invest 2016; 126:1525-37. [PMID: 26999605 PMCID: PMC4811157 DOI: 10.1172/jci81894] [Citation(s) in RCA: 124] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 01/21/2016] [Indexed: 01/01/2023] Open
Abstract
Autoimmune diseases affect 5% to 8% of the population, and females are more susceptible to these diseases than males. Here, we analyzed human thymic transcriptome and revealed sex-associated differences in the expression of tissue-specific antigens that are controlled by the autoimmune regulator (AIRE), a key factor in central tolerance. We hypothesized that the level of AIRE is linked to sexual dimorphism susceptibility to autoimmune diseases. In human and mouse thymus, females expressed less AIRE (mRNA and protein) than males after puberty. These results were confirmed in purified murine thymic epithelial cells (TECs). We also demonstrated that AIRE expression is related to sexual hormones, as male castration decreased AIRE thymic expression and estrogen receptor α-deficient mice did not show a sex disparity for AIRE expression. Moreover, estrogen treatment resulted in downregulation of AIRE expression in cultured human TECs, human thymic tissue grafted to immunodeficient mice, and murine fetal thymus organ cultures. AIRE levels in human thymus grafted in immunodeficient mice depended upon the sex of the recipient. Estrogen also upregulated the number of methylated CpG sites in the AIRE promoter. Together, our results indicate that in females, estrogen induces epigenetic changes in the AIRE gene, leading to reduced AIRE expression under a threshold that increases female susceptibility to autoimmune diseases.
Collapse
Affiliation(s)
- Nadine Dragin
- Sorbonne Universités, UPMC University of Paris 06, Paris, France
- INSERM U974, Paris, France
- CNRS FRE 3617, Paris, France
- AIM, Institute of Myology, Paris, France
| | - Jacky Bismuth
- Sorbonne Universités, UPMC University of Paris 06, Paris, France
- INSERM U974, Paris, France
- CNRS FRE 3617, Paris, France
- AIM, Institute of Myology, Paris, France
| | | | - Maria Grazia Biferi
- Sorbonne Universités, UPMC University of Paris 06, Paris, France
- INSERM U974, Paris, France
- CNRS FRE 3617, Paris, France
- AIM, Institute of Myology, Paris, France
| | - Claire Berthault
- INSERM U668, Unit for Lymphopoiesis, Immunology Department, Pasteur Institute, Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Cellule Pasteur, Paris, France
| | - Alain Serraf
- Hôpital Marie Lannelongue, Le Plessis–Robinson, France
| | - Rémi Nottin
- Hôpital Marie Lannelongue, Le Plessis–Robinson, France
| | - David Klatzmann
- Assistance Publique – Hôpitaux de Paris (AP-HP), Pitié-Salpêtrière Hospital, Biotherapy, Paris, France
| | - Ana Cumano
- INSERM U668, Unit for Lymphopoiesis, Immunology Department, Pasteur Institute, Paris, France
| | - Martine Barkats
- Sorbonne Universités, UPMC University of Paris 06, Paris, France
- INSERM U974, Paris, France
- CNRS FRE 3617, Paris, France
- AIM, Institute of Myology, Paris, France
| | - Rozen Le Panse
- Sorbonne Universités, UPMC University of Paris 06, Paris, France
- INSERM U974, Paris, France
- CNRS FRE 3617, Paris, France
- AIM, Institute of Myology, Paris, France
| | - Sonia Berrih-Aknin
- Sorbonne Universités, UPMC University of Paris 06, Paris, France
- INSERM U974, Paris, France
- CNRS FRE 3617, Paris, France
- AIM, Institute of Myology, Paris, France
| |
Collapse
|
14
|
Chen J, Ren J, Jing Q, Lu S, Zhang Y, Liu Y, Yu C, Gao P, Zong C, Li X, Wang X. TSH/TSHR Signaling Suppresses Fatty Acid Synthase (FASN) Expression in Adipocytes. J Cell Physiol 2015; 230:2233-9. [PMID: 25655684 DOI: 10.1002/jcp.24952] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 01/23/2015] [Indexed: 11/06/2022]
Abstract
TSH/TSHR signaling plays a role in the regulation of lipid metabolism in adipocytes. However, the precise mechanisms are not known. In the present study, we determined the effect of TSH on fatty acid synthase (FASN) expression, and explored the underlying mechanisms. In vitro, TSH reduced FASN expression in both mRNA and protein levels in mature adipocytes and was accompanied by protein kinase A (PKA) activation, cAMP-response element binding protein (CREB) phosphorylation, as well as extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun NH2 -terminal kinase (JNK) activation. TSH-induced downregulation of FASN was partially abolished by inhibition of PKA and ERK, but not JNK. TSHR and FASN expression in visceral tissue was significantly increased in C57BL/6 mice with diet-induced obesity compared with control animals, whereas thyroid TSHR expression was normal. These findings suggest that activation of TSHR directly inhibits FASN expression in mature adipocytes, possibly mediated by PKA and ERK. In obese animals, this function of TSHR seems to be counteracted. The precise mechanisms need further investigation.
Collapse
Affiliation(s)
- Jicui Chen
- Department of Cell Biology, Shandong University School of Medicine, Jinan, China
| | - Jianmin Ren
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, China
| | - Qingping Jing
- Department of Endocrinology, Zibo First Hospital, Zibo, Shandong, China
| | - Sumei Lu
- Department of Cell Biology, Shandong University School of Medicine, Jinan, China
| | - Yuchao Zhang
- Department of Cell Biology, Shandong University School of Medicine, Jinan, China
| | - Yuantao Liu
- Department of Endocrinology, The Second Hospital of Shandong University, Jinan, China
| | - Cong Yu
- Department of Cell Biology, Shandong University School of Medicine, Jinan, China
| | - Peng Gao
- Department of Cell Biology, Shandong University School of Medicine, Jinan, China
| | - Chen Zong
- Department of Cell Biology, Shandong University School of Medicine, Jinan, China
| | - Xia Li
- Department of Cell Biology, Shandong University School of Medicine, Jinan, China
| | - Xiangdong Wang
- Department of Cell Biology, Shandong University School of Medicine, Jinan, China
| |
Collapse
|
15
|
Giménez-Barcons M, Colobran R, Gómez-Pau A, Marín-Sánchez A, Casteràs A, Obiols G, Abella R, Fernández-Doblas J, Tonacchera M, Lucas-Martín A, Pujol-Borrell R. Graves' disease TSHR-stimulating antibodies (TSAbs) induce the activation of immature thymocytes: a clue to the riddle of TSAbs generation? THE JOURNAL OF IMMUNOLOGY 2015; 194:4199-206. [PMID: 25801430 DOI: 10.4049/jimmunol.1500183] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 02/24/2015] [Indexed: 01/22/2023]
Abstract
Graves' disease (GD) is an autoimmune thyroid disease defined by the production of stimulating autoantibodies to the thyroid-stimulating hormone receptor (TSHR) (TSAbs) that induce a sustained state of hyperthyroidism in patients. We previously demonstrated that TSHR, the target of this autoimmune response, is also a key susceptibility gene for GD, probably acting through thymic-dependent central tolerance. We also showed that TSHR is, unexpectedly, expressed in thymocytes. In this report, we confirm the expression of TSHR in thymocytes by protein immunoblotting and quantitative PCR, and show that expression is confined to maturing thymocytes. Using functional assays, we show that thymic TSHR is functional and that TSAbs can stimulate thymocytes through this receptor. This new activity of TSAbs on thymocytes may: 1) explain GD-associated thymic enlargement (hyperplasia), and 2) suggest the provocative hypothesis that the continuous stimulation of thymocytes by TSAbs could lead to a vicious cycle of iterative improvement of the affinity and stimulating capability of initially low-affinity antibacterial (e.g., Yersinia) Abs cross-reactive with TSHR, eventually leading to TSAbs. This may help to fill one of the gaps in our present understanding of unusual characteristics of TSAbs.
Collapse
Affiliation(s)
| | - Roger Colobran
- Vall d'Hebron Institute de Recerca, 08035 Barcelona, Spain; Departament de Biologia Cellular, Fisiologia i Immunologia, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Ana Gómez-Pau
- Vall d'Hebron Institute de Recerca, 08035 Barcelona, Spain
| | - Ana Marín-Sánchez
- Servei d'Immunologia, Hospital Universitari Vall d'Hebron, 08035 Barcelona, Spain
| | - Anna Casteràs
- Servei de Endocrinologia, Hospital Universitari Vall d'Hebron, 08035 Barcelona, Spain
| | - Gabriel Obiols
- Servei de Endocrinologia, Hospital Universitari Vall d'Hebron, 08035 Barcelona, Spain
| | - Raúl Abella
- Servei de Cirurgia, Hospital Universitari Vall d'Hebron, 08035 Barcelona, Spain
| | | | - Massimo Tonacchera
- Department of Clinical and Experimental Medicine, Pisa University, 56126 Pisa, Italy; and
| | - Ana Lucas-Martín
- Departament de Biologia Cellular, Fisiologia i Immunologia, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain; Hospital Universitari Germans Trias i Pujol, 08916 Badalona, Barcelona, Catalonia, Spain
| | - Ricardo Pujol-Borrell
- Vall d'Hebron Institute de Recerca, 08035 Barcelona, Spain; Departament de Biologia Cellular, Fisiologia i Immunologia, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain; Servei d'Immunologia, Hospital Universitari Vall d'Hebron, 08035 Barcelona, Spain;
| |
Collapse
|
16
|
Skogberg G, Lundberg V, Lindgren S, Gudmundsdottir J, Sandström K, Kämpe O, Annerén G, Gustafsson J, Sunnegårdh J, van der Post S, Telemo E, Berglund M, Ekwall O. Altered expression of autoimmune regulator in infant down syndrome thymus, a possible contributor to an autoimmune phenotype. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2014; 193:2187-95. [PMID: 25038256 PMCID: PMC4135177 DOI: 10.4049/jimmunol.1400742] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 06/18/2014] [Indexed: 12/16/2022]
Abstract
Down syndrome (DS), caused by trisomy of chromosome 21, is associated with immunological dysfunctions such as increased frequency of infections and autoimmune diseases. Patients with DS share clinical features, such as autoimmune manifestations and specific autoantibodies, with patients affected by autoimmune polyendocrine syndrome type 1. Autoimmune polyendocrine syndrome type 1 is caused by mutations in the autoimmune regulator (AIRE) gene, located on chromosome 21, which regulates the expression of tissue-restricted Ags (TRAs) in thymic epithelial cells. We investigated the expression of AIRE and TRAs in DS and control thymic tissue using quantitative PCR. AIRE mRNA levels were elevated in thymic tissue from DS patients, and trends toward increased expression of the AIRE-controlled genes INSULIN and CHRNA1 were found. Immunohistochemical stainings showed altered cell composition and architecture of the thymic medulla in DS individuals with increased frequencies of AIRE-positive medullary epithelial cells and CD11c-positive dendritic cells as well as enlarged Hassall's corpuscles. In addition, we evaluated the proteomic profile of thymic exosomes in DS individuals and controls. DS exosomes carried a broader protein pool and also a larger pool of unique TRAs compared with control exosomes. In conclusion, the increased AIRE gene dose in DS could contribute to an autoimmune phenotype through multiple AIRE-mediated effects on homeostasis and function of thymic epithelial cells that affect thymic selection processes.
Collapse
Affiliation(s)
- Gabriel Skogberg
- Department of Rheumatology and Inflammation Research, Institute of Medicine, University of Gothenburg, 405 30 Gothenburg, Sweden;
| | - Vanja Lundberg
- Department of Rheumatology and Inflammation Research, Institute of Medicine, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Susanne Lindgren
- Department of Rheumatology and Inflammation Research, Institute of Medicine, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Judith Gudmundsdottir
- Department of Rheumatology and Inflammation Research, Institute of Medicine, University of Gothenburg, 405 30 Gothenburg, Sweden; Department of Pediatrics at the Institute of Clinical Sciences, University of Gothenburg, 416 86 Gothenburg, Sweden
| | - Kerstin Sandström
- Department of Pediatric Anesthesia and Intensive Care at the Sahlgrenska Academy, University of Gothenburg, 416 86 Gothenburg, Sweden
| | - Olle Kämpe
- Centre of Molecular Medicine, Department of Medicine (Solna), Karolinska Institutet, 171 76 Stockholm, Sweden; Science for Life Laboratory, Uppsala University, 750 03 Uppsala, Sweden
| | - Göran Annerén
- Department of Immunology, Genetics, and Pathology, Science for Life Laboratory, Uppsala University, 751 85 Uppsala, Sweden
| | - Jan Gustafsson
- Department of Women's and Children´s Health, Uppsala University, 751 85 Uppsala, Sweden; and
| | - Jan Sunnegårdh
- Department of Pediatrics at the Institute of Clinical Sciences, University of Gothenburg, 416 86 Gothenburg, Sweden
| | - Sjoerd van der Post
- Proteomics Core Facility at the Sahlgrenska Academy, University of Gothenburg, 413 90 Gothenburg, Sweden
| | - Esbjörn Telemo
- Department of Rheumatology and Inflammation Research, Institute of Medicine, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Martin Berglund
- Department of Rheumatology and Inflammation Research, Institute of Medicine, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Olov Ekwall
- Department of Rheumatology and Inflammation Research, Institute of Medicine, University of Gothenburg, 405 30 Gothenburg, Sweden; Department of Pediatrics at the Institute of Clinical Sciences, University of Gothenburg, 416 86 Gothenburg, Sweden
| |
Collapse
|
17
|
Berrih-Aknin S. Myasthenia Gravis: paradox versus paradigm in autoimmunity. J Autoimmun 2014; 52:1-28. [PMID: 24934596 DOI: 10.1016/j.jaut.2014.05.001] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 05/07/2014] [Indexed: 12/12/2022]
Abstract
Myasthenia Gravis (MG) is a paradigm of organ-specific autoimmune disease (AID). It is mediated by antibodies that target the neuromuscular junction. The purpose of this review is to place MG in the general context of autoimmunity, to summarize the common mechanisms between MG and other AIDs, and to describe the specific mechanisms of MG. We have chosen the most common organ-specific AIDs to compare with MG: type 1 diabetes mellitus (T1DM), autoimmune thyroid diseases (AITD), multiple sclerosis (MS), some systemic AIDs (systemic lupus erythematous (SLE), rheumatoid arthritis (RA), Sjogren's syndrome (SS)), as well as inflammatory diseases of the gut and liver (celiac disease (CeD), Crohn's disease (CD), and primary biliary cirrhosis (PBC)). Several features are similar between all AIDs, suggesting that common pathogenic mechanisms lead to their development. In this review, we address the predisposing factors (genetic, epigenetic, hormones, vitamin D, microbiota), the triggering components (infections, drugs) and their interactions with the immune system [1,2]. The dysregulation of the immune system is detailed and includes the role of B cells, Treg cells, Th17 and cytokines. We particularly focused on the role of TNF-α and interferon type I whose role in MG is very analogous to that in several other AIDS. The implication of AIRE, a key factor in central tolerance is also discussed. Finally, if MG is a prototype of AIDS, it has a clear specificity compared to the other AIDS, by the fact that the target organ, the muscle, is not the site of immune infiltration and B cell expansion, but exclusively that of antibody-mediated pathogenic mechanisms. By contrast, the thymus in the early onset subtype frequently undergoes tissue remodeling, resulting in the development of ectopic germinal centers surrounded by high endothelial venules (HEV), as observed in the target organs of many other AIDs.
Collapse
Affiliation(s)
- Sonia Berrih-Aknin
- Sorbonne Universités, UPMC Univ Paris 06, Myology Research Center UM76, F-75013 Paris, France; INSERM U974, F-75013 Paris, France; CNRS FRE 3617, F-75013 Paris, France; Institute of Myology, F-75013 Paris, France.
| |
Collapse
|
18
|
McLachlan SM, Rapoport B. Breaking tolerance to thyroid antigens: changing concepts in thyroid autoimmunity. Endocr Rev 2014; 35:59-105. [PMID: 24091783 PMCID: PMC3895862 DOI: 10.1210/er.2013-1055] [Citation(s) in RCA: 138] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Accepted: 09/24/2013] [Indexed: 02/06/2023]
Abstract
Thyroid autoimmunity involves loss of tolerance to thyroid proteins in genetically susceptible individuals in association with environmental factors. In central tolerance, intrathymic autoantigen presentation deletes immature T cells with high affinity for autoantigen-derived peptides. Regulatory T cells provide an alternative mechanism to silence autoimmune T cells in the periphery. The TSH receptor (TSHR), thyroid peroxidase (TPO), and thyroglobulin (Tg) have unusual properties ("immunogenicity") that contribute to breaking tolerance, including size, abundance, membrane association, glycosylation, and polymorphisms. Insight into loss of tolerance to thyroid proteins comes from spontaneous and induced animal models: 1) intrathymic expression controls self-tolerance to the TSHR, not TPO or Tg; 2) regulatory T cells are not involved in TSHR self-tolerance and instead control the balance between Graves' disease and thyroiditis; 3) breaking TSHR tolerance involves contributions from major histocompatibility complex molecules (humans and induced mouse models), TSHR polymorphism(s) (humans), and alternative splicing (mice); 4) loss of tolerance to Tg before TPO indicates that greater Tg immunogenicity vs TPO dominates central tolerance expectations; 5) tolerance is induced by thyroid autoantigen administration before autoimmunity is established; 6) interferon-α therapy for hepatitis C infection enhances thyroid autoimmunity in patients with intact immunity; Graves' disease developing after T-cell depletion reflects reconstitution autoimmunity; and 7) most environmental factors (including excess iodine) "reveal," but do not induce, thyroid autoimmunity. Micro-organisms likely exert their effects via bystander stimulation. Finally, no single mechanism explains the loss of tolerance to thyroid proteins. The goal of inducing self-tolerance to prevent autoimmune thyroid disease will require accurate prediction of at-risk individuals together with an antigen-specific, not blanket, therapeutic approach.
Collapse
Affiliation(s)
- Sandra M McLachlan
- Thyroid Autoimmune Disease Unit, Cedars-Sinai Research Institute, and University of California-Los Angeles School of Medicine, Los Angeles, California 90048
| | | |
Collapse
|
19
|
Breaking tolerance in transgenic mice expressing the human TSH receptor A-subunit: thyroiditis, epitope spreading and adjuvant as a 'double edged sword'. PLoS One 2012; 7:e43517. [PMID: 22970131 PMCID: PMC3436763 DOI: 10.1371/journal.pone.0043517] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Accepted: 07/23/2012] [Indexed: 02/05/2023] Open
Abstract
Transgenic mice with the human thyrotropin-receptor (TSHR) A-subunit targeted to the thyroid are tolerant of the transgene. In transgenics that express low A-subunit levels (Lo-expressors), regulatory T cell (Treg) depletion using anti-CD25 before immunization with adenovirus encoding the A-subunit (A-sub-Ad) breaks tolerance, inducing extensive thyroid lymphocytic infiltration, thyroid damage and antibody spreading to other thyroid proteins. In contrast, no thyroiditis develops in Hi-expressor transgenics or wild-type mice. Our present goal was to determine if thyroiditis could be induced in Hi-expressor transgenics using a more potent immunization protocol: Treg depletion, priming with Complete Freund's Adjuvant (CFA) + A-subunit protein and further Treg depletions before two boosts with A-sub-Ad. As controls, anti-CD25 treated Hi- and Lo-expressors and wild-type mice were primed with CFA+ mouse thyroglobulin (Tg) or CFA alone before A-sub-Ad boosting. Thyroiditis developed after CFA+A-subunit protein or Tg and A-sub-Ad boosting in Lo-expressor transgenics but Hi- expressors (and wild-type mice) were resistant to thyroiditis induction. Importantly, in Lo-expressors, thyroiditis was associated with the development of antibodies to the mouse TSHR downstream of the A-subunit. Unexpectedly, we observed that the effect of bacterial products on the immune system is a “double-edged sword”. On the one hand, priming with CFA (mycobacteria emulsified in oil) plus A-subunit protein broke tolerance to the A-subunit in Hi-expressor transgenics leading to high TSHR antibody levels. On the other hand, prior treatment with CFA in the absence of A-subunit protein inhibited responses to subsequent immunization with A-sub-Ad. Consequently, adjuvant activity arising in vivo after bacterial infections combined with a protein autoantigen can break self-tolerance but in the absence of the autoantigen, adjuvant activity can inhibit the induction of immunity to autoantigens (like the TSHR) displaying strong self-tolerance.
Collapse
|
20
|
McLachlan SM, Aliesky HA, Chen CR, Rapoport B. Role of self-tolerance and chronic stimulation in the long-term persistence of adenovirus-induced thyrotropin receptor antibodies in wild-type and transgenic mice. Thyroid 2012; 22:931-7. [PMID: 22827528 PMCID: PMC3429281 DOI: 10.1089/thy.2012.0008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND Graves'-like disease, reflected by thyrotropin receptor (TSHR) antibodies and hyperthyroidism in some mouse strains, can be induced by immunization with adenovirus-expressing DNA for the human TSHR or its A-subunit. The conventional approach involves two or three adenovirus injections at 3-week intervals and euthanasia 10 weeks after the first injection. To investigate TSHR antibody persistence in mice with differing degrees of self-tolerance to the TSHR A-subunit, we studied the effect of delaying euthanasia until 20 weeks after the initial immunization. METHODS Wild-type (WT) mice and transgenic (tg) mice expressing low intrathyroidal levels of the human TSHR A-subunit were immunized with A-subunit-adenovirus on two occasions; a second group of mice was immunized on three occasions. Sera obtained 4, 10, and 20 weeks (euthanasia) after the initial immunization were tested for thyrotropin (TSH) binding inhibition (TBI), antibody binding to TSHR A-subunit protein-coated enzyme-linked immunosorbent assay (ELISA) plates, and thyroid stimulating antibody activity (TSAb; cyclic adenosine monophosphate [cAMP] generation). Serum thyroxine (T4) and thyroid histology were studied at euthanasia. RESULTS THE majority of WT mice retained high TSHR antibody levels measured by TBI or ELISA at euthanasia but only about 50% were TSAb positive. Low-expressor tgs exhibited self-tolerance, with fewer mice positive by TBI or ELISA and antibody levels were lower than in WT littermates. In WT mice, antibody persistence was similar after two or three immunizations; for tgs, only mice immunized three times had detectable TSAb at 20 weeks. Unlike our previous observations of hyperthyroidism in WT mice examined 4 or 10 weeks after immunization, all mice were euthyroid at 20 weeks. CONCLUSIONS Our findings for induced TSHR antibodies in mice, similar to data for human thyroid autoantibodies, indicate that the parameters that contribute to the concentration of the antibody and thereby play a critical role in long-term persistence of TSHR antibodies are the degree of self-tolerance to the TSHR and chronic stimulation.
Collapse
Affiliation(s)
- Sandra M McLachlan
- Thyroid Autoimmune Disease Unit, Cedars-Sinai Research Institute, Los Angeles, CA 90048, USA.
| | | | | | | |
Collapse
|
21
|
Lu S, Guan Q, Liu Y, Wang H, Xu W, Li X, Fu Y, Gao L, Zhao J, Wang X. Role of extrathyroidal TSHR expression in adipocyte differentiation and its association with obesity. Lipids Health Dis 2012; 11:17. [PMID: 22289392 PMCID: PMC3285521 DOI: 10.1186/1476-511x-11-17] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Accepted: 01/30/2012] [Indexed: 11/27/2022] Open
Abstract
Background Obesity is known to be associated with higher risks of cardiovascular disease, metabolic syndrome, and diabetes mellitus. Thyroid-stimulating hormone (TSHR) is the receptor for thyroid-stimulating hormone (TSH, or thyrotropin), the key regulator of thyroid functions. The expression of TSHR, once considered to be limited to thyrocytes, has been so far detected in many extrathyroidal tissues including liver and fat. Previous studies have shown that TSHR expression is upregulated when preadipocytes differentiate into mature adipocytes, suggestive of a possible role of TSHR in adipogenesis. However, it remains unclear whether TSHR expression in adipocytes is implicated in the pathogenesis of obesity. Methods In the present study, TSHR expression in adipose tissues from both mice and human was analyzed, and its association with obesity was evaluated. Results We here showed that TSHR expression was increased at both mRNA and protein levels when 3T3-L1 preadipocytes were induced to differentiate. Knockdown of TSHR blocked the adipocyte differentiation of 3T3-L1 preadipocytes as evaluated by Oil-red-O staining for lipid accumulation and by RT-PCR analyses of PPAR-γ and ALBP mRNA expression. We generated obesity mice (C57/BL6) by high-fat diet feeding and found that the TSHR protein expression in visceral adipose tissues from obesity mice was significantly higher in comparison with the non-obesity control mice (P < 0.05). Finally, the TSHR expression in adipose tissues was determined in 120 patients. The results showed that TSHR expression in subcutaneous adipose tissue is correlated with BMI (body mass index). Conclusion Taken together, these results suggested that TSHR is an important regulator of adipocyte differentiation. Dysregulated expression of TSHR in adipose tissues is associated with obesity, which may involve a mechanism of excess adipogenesis.
Collapse
Affiliation(s)
- Sumei Lu
- The Institute of Cell Biology, Shandong University School of Medicine, Jinan, China, 250012
| | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Abstract
BACKGROUND Graves' disease, caused by stimulatory thyrotropin receptor (TSHR) autoantibodies, has not been observed in animals. In contrast, Hashimoto's thyroiditis develops in chickens, rats, mice, dogs, and marmosets. Attempts to induce an immune response in mice to the luteinizing-hormone receptor suggested that autoantigen glycosylation was one parameter involved in breaking self-tolerance. Over evolution, TSHR glycosylation increased from three asparagine-linked-glycans (N-glycans) in fish to six N-glycans in humans and great apes. All other placental mammals lack one N-glycan in the shed TSHR A-subunit, the primary Graves' disease autoantigen. We hypothesized that (a) lesser TSHR A-subunit glycosylation reduces immunogenicity, accounting for the absence of Graves' disease in most placental mammals; (b) due to human-like A-subunit glycosylation, Graves' disease might arise in great apes. Here, we review and analyze the literature on this subject and report the results of a survey of veterinarians at primate centers and zoos in North America. SUMMARY Previous experimental data from induced TSHR antibodies in mice support a role for A-subunit glycosylation in breaking self-tolerance. An extensive search of the great-ape literature revealed five reports of noncongenital thyroid dysfunction, four with hypothyroidism and one with hyperthyroidism. The latter was a gorilla who was treated with anti-thyroid drugs but is now deceased. Neither serum nor thyroid tissue from this gorilla were available for analysis. The survey of veterinarians revealed that none of the 979 chimpanzees in primate research centers had a diagnosis of noncongenital thyroid dysfunction and among ∼1100 great apes (gorillas, orangutans, and chimpanzees) in U.S. zoos, only three were hypothyroid, and none were hyperthyroid. CONCLUSIONS Graves' disease appears to be either very rare or does not occur in great apes based on the literature and a survey of veterinarians. Although the available data do not advance our hypothesis, there is a paucity of information regarding thyroid function tests and thyroid autoantibodies in the great apes In addition, these primates may be protected against TSHR autoimmunity by the absence of genetic polymorphisms and putative environmental triggers. Finally, larger numbers of great apes need to be followed, and tests of thyroid function and thyroid autoantibodies be performed, to confirm that spontaneous Graves' disease is restricted to humans.
Collapse
Affiliation(s)
- Sandra M McLachlan
- Autoimmune Disease Unit, Cedars-Sinai Research Institute, UCLA School of Medicine, Los Angeles, California 90048, USA.
| | | | | |
Collapse
|
23
|
Chen CR, Aliesky HA, Rapoport B, McLachlan SM. An attempt to induce "Graves' disease of the gonads" by immunizing mice with the luteinizing hormone receptor provides insight into breaking tolerance to self-antigens. Thyroid 2011; 21:773-81. [PMID: 21649471 PMCID: PMC3123529 DOI: 10.1089/thy.2010.0460] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Gonadotropin receptors, unlike the thyrotropin receptor (TSHR), are not cleaved into disulfide-linked A- and B-subunits, nor do they shed A-subunits. Heavily glycosylated TSHR A-subunits initiate or amplify responses leading to stimulating TSHR-autoantibodies and Graves' hyperthyroidism. METHODS To investigate the possibility that mice immunized with luteinizing hormone receptor (LHR) would develop functional antibodies, we constructed adenoviruses expressing the rat-LH holoreceptor (LHR-Ad) and an LHR A-subunit equivalent (LHR-289-Ad). Female BALB/c mice were immunized with high doses (10(11) particles) of LHR-Ad, LHR-289-Ad, or control (Con)-Ad. Sera were tested using LHR-expressing eukaryotic cells for antibody binding by flow cytometry and for bioactivity by measuring cyclic adenosine monophosphate (cAMP) stimulation. RESULTS Elevated serum binding to LHR cells in some LHR-Ad and LHR-289-Ad immunized mice was not specific for LHR-expressing cells. Moreover, sera lacked bioactivity, consistent with unchanged serum estradiol and ovary histology. The difference between rat and mouse LHR-ectodomains is relatively small (3% at the amino-acid level). In contrast, despite amino-acid identity, immunization of mice with adenovirus expressing membrane-bound mouse thyroid peroxidase (TPO), but not soluble mouse TPO ectodomain, elicited strong TPO-specific antibodies. CONCLUSIONS Our investigations provide insight into antibody responses to self-antigens. First, antibodies are induced to large self-antigens like mouse-TPO when membrane bound. Second, lesser amino acid homology between the immunogen and mouse protein (91% vs. 97% for the human-TSHR and rat-LHR, respectively) favors antibody induction. Finally, from previous studies demonstrating the immunogenicity of the highly glycosylated human TSHR A-subunit versus our present data for the nonimmunogenic less glycosylated rat LHR, we suggest that the extent of glycosylation contributes to breaking self-tolerance.
Collapse
Affiliation(s)
- Chun-Rong Chen
- Thyroid Autoimmune Disease Unit, Cedars-Sinai Research Institute and UCLA School of Medicine, Los Angeles, California 90048, USA
| | | | | | | |
Collapse
|
24
|
Colobran R, Armengol MDP, Faner R, Gärtner M, Tykocinski LO, Lucas A, Ruiz M, Juan M, Kyewski B, Pujol-Borrell R. Association of an SNP with intrathymic transcription of TSHR and Graves' disease: a role for defective thymic tolerance. Hum Mol Genet 2011; 20:3415-23. [PMID: 21642385 DOI: 10.1093/hmg/ddr247] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Graves' disease (GD) is the paradigm of an anti-receptor autoimmune disease, with agonistic auto-antibodies against the thyrotropin receptor (TSHR-thyroid-stimulating hormone receptor) being the underlying pathogenic effector mechanism. The TSHR belongs to the category of tissue-restricted antigens, which are promiscuously expressed in the thymus and thereby induce central T cell tolerance. In order to understand the association between TSHR gene polymorphisms and GD, we tested the hypothesis that TSHR gene variants affect susceptibility to GD by influencing levels of TSHR transcription in the thymus. We show that thymic glands from non-autoimmune donors homozygous for the rs179247 SNP predisposing allele of TSHR had significantly fewer TSHR mRNA transcripts than carriers of the protective allele. In addition, in heterozygous individuals, the TSHR predisposing allele was expressed at a lower level than the protective one as demonstrated by allele-specific transcript quantification. This unbalanced allelic expression was detectable in both thymic epithelial cells and thymocytes. Since the level of self-antigen expression is known to influence the threshold of central tolerance, these results are compatible with the notion that defective central tolerance contributes to the pathogenesis of GD, a scenario already implicated in type 1 diabetes mellitus, myasthenia gravis and autoimmune myocarditis.
Collapse
Affiliation(s)
- Roger Colobran
- Laboratory of Immunobiology for Research and Applications to Diagnostic, Banc de Sang i Teixits, Institut d'Investigacióen Ciències de Salut Germans Trias i Pujol, Badalona 08916, Catalonia, Spain
| | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Nakahara M, Mitsutake N, Sakamoto H, Chen CR, Rapoport B, McLachlan SM, Nagayama Y. Enhanced response to mouse thyroid-stimulating hormone (TSH) receptor immunization in TSH receptor-knockout mice. Endocrinology 2010; 151:4047-54. [PMID: 20555026 DOI: 10.1210/en.2010-0315] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Graves-like hyperthyroidism is induced in BALB/c mice by immunization with adenovirus expressing the human TSH receptor (TSHR) A-subunit (amino acids 1-289). However, because of nonidentity between the human and mouse TSHR ( approximately 87% amino acid homology), we compared the responses of mice immunized with adenoviruses expressing either the mouse or the human TSHR A-subunit. Wild-type (wt) BALB/c mice immunized with the mouse A-subunit developed neither TSHR antibodies (measured by flow cytometry) nor thyroid lymphocytic infiltration. However, wt C57BL/6 mice developed sparse intrathyroidal lymphocyte infiltration without antibody production. Depletion of naturally occurring regulatory CD4(+)CD25(+) T cells had little effect. These results indicate the inability to break tolerance to the mouse TSHR in wt mice. In contrast, TSHR knockout (KO) BALB/c mice generated mouse TSHR antibodies in response to mouse A-subunit immunization and augmented human TSHR antibody response to human A-subunit immunization. Thyroid-stimulating antibody titers measured in a functional bioassay were comparable in human A-subunit immunized wt mice and in TSHR KO mice immunized with either the mouse or human A-subunit. In conclusion, immune response to the mouse TSHR is readily induced in TSHR KO but not in wt mice. Only in the former does immunization with adenovirus expressing the mouse A-subunit generate antibodies capable of activating the mouse TSHR. TSHR KO mice are, therefore, of value for future studies dissecting the autoimmune response to the mouse TSHR.
Collapse
Affiliation(s)
- Mami Nakahara
- Department of Medical Gene Technology, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | | | | | | | | | | | | |
Collapse
|
26
|
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.
Collapse
Affiliation(s)
- Nuria Colomé
- Vall d'Hebron University Hospital, Barcelona, Spain
| | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Autoimmune thyroiditis: a model uniquely suited to probe regulatory T cell function. J Autoimmun 2009; 33:239-46. [PMID: 19822405 DOI: 10.1016/j.jaut.2009.09.004] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Murine experimental autoimmune thyroiditis (EAT) is a model for Hashimoto's thyroiditis that has served as a prototype of T cell-mediated autoimmunity for more than three decades. Key roles for MHC restriction and autoantigen influence on susceptibility to autoimmunity have been demonstrated in EAT. Moreover, it has served a unique role in investigations of self tolerance. In the early 1980s, self tolerance and resistance to EAT induction could be enhanced by increasing circulating levels of the autoantigen, thyroglobulin (Tg), by exogenous addition as well as endogenous release. This observation, directly linking circulating self antigen to self tolerance, led to subsequent investigations of the role of regulatory T cells (Tregs) in self tolerance. These studies revealed that protection against autoimmunity, in both naive and tolerized mice, was mediated by thymically-derived CD4(+)CD25(+)Foxp3(+) Tregs. Moreover, these naturally-existing Tregs required proper costimulation, in context with autoantigen presentation, to maintain and enhance self tolerance. In particular was the selected use of MHC- and heterologous Tg-restricted models from both conventional and transgenic mice. These models helped to elucidate the complex interplay between autoantigen presentation and MHC class II-mediated T cell selection in the development of Treg and autoreactive T cell repertoires determining susceptibility to autoimmunity. Here we describe these investigations in further detail, providing a context for how EAT has helped shape our understanding of self tolerance and autoimmunity.
Collapse
|
28
|
Dooley J, Erickson M, Farr AG. Lessons from thymic epithelial heterogeneity: FoxN1 and tissue-restricted gene expression by extrathymic, endodermally derived epithelium. THE JOURNAL OF IMMUNOLOGY 2009; 183:5042-9. [PMID: 19786540 DOI: 10.4049/jimmunol.0901371] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Modeling of thymic epithelial differentiation has been guided by several important underlying assumptions. One is that within epithelial tissues derived from pharyngeal endoderm, FoxN1 expression is signature for the thymic epithelial lineage. Another is that expression of tissue-restricted Ag (TRA) is a unique feature of thymic epithelium. In this murine study, we evaluate the thymic expression of a subset of TRA, parathyroid hormone, calcitonin, and thyroglobulin, as part of an effort to better define the heterogeneity of medullary thymic epithelial cells. In this study, we demonstrate that both conventional and cystic epithelial cells display a history of FoxN1 expression using a cre-lox approach. We also document that extrathymic epithelial tissues that originate from pharyngeal endoderm also have a history of FoxN1 expression, indicating that FoxN1 expression per se is not a signature for the thymic lineage and suggesting that FoxN1 expression, whereas necessary for thymic epithelium, development, is not sufficient for this process to occur. Both cystic and conventional medullary thymic epithelial cells express these TRAs, as do extrathymic epithelial tissues that are not usually considered to be sources of these molecules. This finding supports the proposition that promiscuous gene expression is not unique to the thymus. Furthermore, the pattern of promiscuous gene expression in these extrathymic epithelia is consistent with developmental regulation processes and suggests that it is premature to discard the possibility that some promiscuous gene expression in the thymus reflects normal differentiation programs of epithelia.
Collapse
Affiliation(s)
- James Dooley
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | | | | |
Collapse
|
29
|
Misharin AV, Rapoport B, McLachlan SM. Thyroid antigens, not central tolerance, control responses to immunization in BALB/c versus C57BL/6 mice. Thyroid 2009; 19:503-9. [PMID: 19348579 PMCID: PMC2857445 DOI: 10.1089/thy.2008.0420] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND Vaccination with cDNA for the human thyrotropin receptor (TSHR) in a plasmid, without adjuvant, induces TSHR antibodies in C57BL/6 but rarely in BALB/c mice. This outcome could be due to a difference between "high" versus "low" antibody responder mouse strains. However, unlike their poor response to TSHR-DNA vaccination, BALB/c mice vaccinated with thyroid peroxidase (TPO)-cDNA readily develop antibodies to TPO. We hypothesized that insight into these conundrums would be provided by the following differences in central tolerance: (i) between two mouse strains (C57BL/6 versus BALB/c) for the TSHR; and (ii) between two thyroid autoantigens (TPO and the TSHR) in one mouse strain (BALB/c). METHODS We studied autoantigen expression using real-time polymerase chain reaction to quantify mRNA transcripts for the TSHR, TPO, and thyroglobulin (Tg) in thymic tissue (as well as in thyroid) of young mice. RESULTS Our hypothesis was not confirmed. Intrathymic TSHR transcript expression was similar in BALB/c and C57BL/6 mice. Moreover, thymic mRNA transcripts for TSHR and TPO were comparable. Unlike the 10-fold differences for the autoantigens in thyroid tissue (Tg greater than TPO which, in turn was greater than the TSHR), intrathymic transcripts for TPO and the TSHR were similar, both being slightly lower than the level for Tg. CONCLUSIONS Central tolerance, assessed by measuring intrathymic transcripts of thyroid autoantigens, does not explain the different outcome of TSHR-DNA vaccination in BALB/c and C57BL/6 mice, or even susceptibility versus resistance to hyperthyroidism induced by TSHR-adenovirus. Instead, differences in MHC and TSHR T-cell epitopes likely contribute to TSHR antibody development (or not) following DNA plasmid immunization. The greater immunogenicity of TPO versus TSHR probably relates to the greater number of nonhomologous amino acids in the human and mouse TPO ectodomains (78 amino acids) than in the human and mouse TSHR ectodomains (58 amino acids). Overall, the autoantigens themselves, not central tolerance, control DNA plasmid-induced immunity to TPO and the TSHR.
Collapse
|