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Krishnamurthy B, Lacorcia M, Kay TWH, Thomas HE, Mannering SI. Monitoring immunomodulation strategies in type 1 diabetes. Front Immunol 2023; 14:1206874. [PMID: 37346035 PMCID: PMC10279879 DOI: 10.3389/fimmu.2023.1206874] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Accepted: 05/26/2023] [Indexed: 06/23/2023] Open
Abstract
Type 1 diabetes (T1D) is a T-cell mediated autoimmune disease. Short-term treatment with agents targeting T cells, B cells and inflammatory cytokines to modify the disease course resulted in a short-term pause in disease activity. Lessons learnt from these trials will be discussed in this review. It is expected that effective disease-modifying agents will become available for use in earlier stages of T1D. Progress has been made to analyze antigen-specific T cells with standardization of T cell assay and discovery of antigen epitopes but there are many challenges. High-dimensional profiling of gene, protein and TCR expression at single cell level with innovative computational tools should lead to novel biomarker discovery. With this, assays to detect, quantify and characterize the phenotype and function of antigen-specific T cells will continuously evolve. An improved understanding of T cell responses will help researchers and clinicians to better predict disease onset, and progression, and the therapeutic efficacy of interventions to prevent or arrest T1D.
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Affiliation(s)
- Balasubramanian Krishnamurthy
- Immunology and Diabetes Unit, St Vincent’s Institute, Fitzroy, VIC, Australia
- Department of Medicine, St Vincent’s Hospital, University of Melbourne, Fitzroy, VIC, Australia
| | - Matthew Lacorcia
- Immunology and Diabetes Unit, St Vincent’s Institute, Fitzroy, VIC, Australia
| | - Thomas W. H. Kay
- Immunology and Diabetes Unit, St Vincent’s Institute, Fitzroy, VIC, Australia
- Department of Medicine, St Vincent’s Hospital, University of Melbourne, Fitzroy, VIC, Australia
| | - Helen E. Thomas
- Immunology and Diabetes Unit, St Vincent’s Institute, Fitzroy, VIC, Australia
- Department of Medicine, St Vincent’s Hospital, University of Melbourne, Fitzroy, VIC, Australia
| | - Stuart I. Mannering
- Immunology and Diabetes Unit, St Vincent’s Institute, Fitzroy, VIC, Australia
- Department of Medicine, St Vincent’s Hospital, University of Melbourne, Fitzroy, VIC, Australia
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Kim YK, Walters JA, Moss ND, Wells KL, Sheridan R, Miranda JG, Benninger RKP, Pyle LL, O'Brien RM, Sussel L, Davidson HW. Zinc transporter 8 haploinsufficiency protects against beta cell dysfunction in type 1 diabetes by increasing mitochondrial respiration. Mol Metab 2022; 66:101632. [PMID: 36347424 PMCID: PMC9672421 DOI: 10.1016/j.molmet.2022.101632] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 10/17/2022] [Accepted: 11/03/2022] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVE Zinc transporter 8 (ZnT8) is a major humoral target in human type 1 diabetes (T1D). Polymorphic variants of Slc30A8, which encodes ZnT8, are also associated with protection from type 2 diabetes (T2D). The current study examined whether ZnT8 might play a role beyond simply being a target of autoimmunity in the pathophysiology of T1D. METHODS The phenotypes of NOD mice with complete or partial global loss of ZnT8 were determined using a combination of disease incidence, histological, transcriptomic, and metabolic analyses. RESULTS Unexpectedly, while complete loss of ZnT8 accelerated spontaneous T1D, heterozygosity was partially protective. In vivo and in vitro studies of ZnT8 deficient NOD.SCID mice suggested that the accelerated disease was due to more rampant autoimmunity. Conversely, beta cells in heterozygous animals uniquely displayed increased mitochondrial fitness under mild proinflammatory conditions. CONCLUSIONS In pancreatic beta cells and immune cell populations, Zn2+ plays a key role as a regulator of redox signaling and as an independent secondary messenger. Importantly, Zn2+ also plays a major role in maintaining mitochondrial homeostasis. Our results suggest that regulating mitochondrial fitness by altering intra-islet zinc homeostasis may provide a novel mechanism to modulate T1D pathophysiology.
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Affiliation(s)
- Yong Kyung Kim
- Barbara Davis Center for Diabetes, University of Colorado Denver Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Jay A Walters
- Barbara Davis Center for Diabetes, University of Colorado Denver Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Nicole D Moss
- Barbara Davis Center for Diabetes, University of Colorado Denver Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Kristen L Wells
- Barbara Davis Center for Diabetes, University of Colorado Denver Anschutz Medical Campus, Aurora, CO 80045, USA; RNA Biology Initiative, Biochemistry and Molecular Genetics Department, University of Colorado Denver Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Ryan Sheridan
- RNA Biology Initiative, Biochemistry and Molecular Genetics Department, University of Colorado Denver Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Jose G Miranda
- Barbara Davis Center for Diabetes, University of Colorado Denver Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Richard K P Benninger
- Barbara Davis Center for Diabetes, University of Colorado Denver Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Laura L Pyle
- Barbara Davis Center for Diabetes, University of Colorado Denver Anschutz Medical Campus, Aurora, CO 80045, USA; Director Child Health Research Biostatistics Core, Department of Pediatrics, University of Colorado Denver Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Richard M O'Brien
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Lori Sussel
- Barbara Davis Center for Diabetes, University of Colorado Denver Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Howard W Davidson
- Barbara Davis Center for Diabetes, University of Colorado Denver Anschutz Medical Campus, Aurora, CO 80045, USA; Department of Immunology and Microbiology, University of Colorado Denver Anschutz Medical Campus, Aurora, CO 80045, USA.
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Buckle I, Loaiza Naranjo JD, Bergot AS, Zhang V, Talekar M, Steptoe RJ, Thomas R, Hamilton-Williams EE. Tolerance induction by liposomes targeting a single CD8 epitope IGRP 206-214 in a model of type 1 diabetes is impeded by co-targeting a CD4 + islet epitope. Immunol Cell Biol 2021; 100:33-48. [PMID: 34668580 DOI: 10.1111/imcb.12506] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 10/06/2021] [Accepted: 10/18/2021] [Indexed: 12/01/2022]
Abstract
The autoimmune disease type 1 diabetes is predominantly mediated by CD8+ cytotoxic T-cell destruction of islet beta cells, of which islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP)206-214 is a dominant target antigen specificity. Previously, we found that a liposome-based antigen-specific immunotherapy encapsulating the CD4+ T-cell islet epitope 2.5mim together with the nuclear factor-κB inhibitor calcitriol induced regulatory T cells and protected from diabetes in NOD mice. Here we investigated whether the same system delivering IGRP206-214 could induce antigen-specific CD8+ T-cell-targeted immune regulation and delay diabetes. Subcutaneous administration of IGRP206-214 /calcitriol liposomes transiently activated and expanded IGRP-specific T-cell receptor transgenic 8.3 CD8+ T cells. Liposomal co-delivery of calcitriol was required to optimally suppress endogenous IGRP-specific CD8+ T-cell interferon-γ production and cytotoxicity. Concordantly, a short course of IGRP206-214 /calcitriol liposomes delayed diabetes progression and reduced insulitis. However, when IGRP206-214 /calcitriol liposomes were delivered together with 2.5mim /calcitriol liposomes, disease protection was not observed and the regulatory effect of 2.5mim /calcitriol liposomes was abrogated. Thus, tolerogenic liposomes that target either a dominant CD8+ or a CD4+ T-cell islet epitope can delay diabetes progression but combining multiple epitopes does not enhance protection.
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Affiliation(s)
- Irina Buckle
- The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, QLD, Australia
| | - Jeniffer D Loaiza Naranjo
- The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, QLD, Australia
| | - Anne-Sophie Bergot
- The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, QLD, Australia
| | - Vivian Zhang
- The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, QLD, Australia
| | - Meghna Talekar
- The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, QLD, Australia
| | - Raymond J Steptoe
- The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, QLD, Australia
| | - Ranjeny Thomas
- The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, QLD, Australia
| | - Emma E Hamilton-Williams
- The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, QLD, Australia
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Xu X, Bian L, Shen M, Li X, Zhu J, Chen S, Xiao L, Zhang Q, Chen H, Xu K, Yang T. Multipeptide-coupled nanoparticles induce tolerance in 'humanised' HLA-transgenic mice and inhibit diabetogenic CD8 + T cell responses in type 1 diabetes. Diabetologia 2017; 60:2418-2431. [PMID: 28887632 DOI: 10.1007/s00125-017-4419-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Accepted: 07/12/2017] [Indexed: 12/25/2022]
Abstract
AIMS/HYPOTHESIS Induction of antigen-specific immunological tolerance may provide an attractive immunotherapy in the NOD mouse model but the conditions that lead to the successful translation to human type 1 diabetes are limited. In this study, we covalently linked 500 nm carboxylated polystyrene beads (PSB) with a mixture of immunodominant HLA-A*02:01-restricted epitopes (peptides-PSB) that may have high clinical relevance in humans as they promote immune tolerance; we then investigated the effect of the nanoparticle-peptide complexes on T cell tolerance. METHODS PSB-coupled mixtures of HLA-A*02:01-restricted epitopes were administered to HHD II mice via intravenous injection. The effects on delaying the course of the disease were verified in NOD.β2m null HHD mice. The diabetogenic HLA-A*02:01-restricted cytotoxic lymphocyte (CTL) responses to treatment with peptides-PSB were validated in individuals with type 1 diabetes. RESULTS We showed that peptides-PSB could induce antigen-specific tolerance in HHD II mice. The protective immunological mechanisms were mediated through the function of CD4+CD25+ regulatory T cells, suppressive T cell activation and T cell anergy. Furthermore, the peptides-PSB induced an activation and accumulation of regulatory T cells and CD11c+ dendritic cells through a rapid production of CD169+ macrophage-derived C-C motif chemokine 22 (CCL22). Peptides-PSB also prevented diabetes in 'humanised' NOD.β2m null HHD mice and suppressed pathogenic CTL responses in people with type 1 diabetes. CONCLUSIONS/INTERPRETATION Our findings demonstrate for the first time the potential for using multipeptide-PSB complexes to induce T cell tolerance and halt the autoimmune process. These findings represent a promising platform for an antigen-specific tolerance strategy in type 1 diabetes and highlight a mechanism through which metallophilic macrophages mediate the early cell-cell interactions required for peptides-PSB-induced immune tolerance.
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Affiliation(s)
- Xinyu Xu
- Department of Endocrinology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, Jiangsu, People's Republic of China
| | - Lingling Bian
- Department of Endocrinology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, Jiangsu, People's Republic of China
- Department of Endocrinology, Yancheng City No.1 People's Hospital, Yancheng, Jiangsu Province, People's Republic of China
| | - Min Shen
- Department of Endocrinology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, Jiangsu, People's Republic of China
| | - Xin Li
- Department of Endocrinology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, Jiangsu, People's Republic of China
| | - Jing Zhu
- Department of Endocrinology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, Jiangsu, People's Republic of China
| | - Shuang Chen
- Department of Endocrinology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, Jiangsu, People's Republic of China
| | - Lei Xiao
- Department of Endocrinology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, Jiangsu, People's Republic of China
| | - Qingqing Zhang
- Department of Endocrinology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, Jiangsu, People's Republic of China
| | - Heng Chen
- Department of Endocrinology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, Jiangsu, People's Republic of China
| | - Kuanfeng Xu
- Department of Endocrinology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, Jiangsu, People's Republic of China
| | - Tao Yang
- Department of Endocrinology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, Jiangsu, People's Republic of China.
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CD8 + T cells specific for the islet autoantigen IGRP are restricted in their T cell receptor chain usage. Sci Rep 2017; 7:44661. [PMID: 28300170 PMCID: PMC5353542 DOI: 10.1038/srep44661] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 02/13/2017] [Indexed: 11/21/2022] Open
Abstract
CD8+ T cells directed against beta cell autoantigens are considered relevant for the pathogenesis of type 1 diabetes. Using single cell T cell receptor sequencing of CD8+ T cells specific for the IGRP265-273 epitope, we examined whether there was expansion of clonotypes and sharing of T cell receptor chains in autoreactive CD8+ T cell repertoires. HLA-A*0201 positive type 1 diabetes patients (n = 19) and controls (n = 18) were analysed. TCR α- and β-chain sequences of 418 patient-derived IGRP265-273-multimer+ CD8+ T cells representing 48 clonotypes were obtained. Expanded populations of IGRP265-273-specific CD8+ T cells with dominant clonotypes that had TCR α-chains shared across patients were observed. The SGGSNYKLTF motif corresponding to TRAJ53 was contained in 384 (91.9%) cells, and in 20 (41.7%) patient-derived clonotypes. TRAJ53 together with TRAV29/DV5 was found in 15 (31.3%) clonotypes. Using next generation TCR α-chain sequencing, we found enrichment of one of these TCR α-chains in the memory CD8+ T cells of patients as compared to healthy controls. CD8+ T cell clones bearing the enriched motifs mediated antigen-specific target cell lysis. We provide the first evidence for restriction of T cell receptor motifs in the alpha chain of human CD8+ T cells with specificity to a beta cell antigen.
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Chujo D, Nguyen TS, Foucat E, Blankenship D, Banchereau J, Nepom GT, Chaussabel D, Ueno H. Adult-onset type 1 diabetes patients display decreased IGRP-specific Tr1 cells in blood. Clin Immunol 2015; 161:270-7. [PMID: 26341315 DOI: 10.1016/j.clim.2015.08.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 08/25/2015] [Accepted: 08/26/2015] [Indexed: 11/26/2022]
Abstract
The breakdown of immune tolerance against islet antigens causes type 1 diabetes (T1D). The antigens associated with adult-onset T1D (AT1D) remain largely undefined. It is possible that AT1D patients display a unique type of CD4(+) T cells specific for a certain islet antigen. Here we analyzed the cytokine production profiles of CD4(+) helper T (Th) cells that are specific for three islet antigens; GAD65, preproinsulin, and IGRP in patients with AT1D, juvenile-onset T1D (JT1D), and age-, gender- and human leukocyte antigen (HLA)-matched control adults. While IGRP-specific Th cells in AT1D patients were dominantly Th1 cells, IGRP-specific Th cells in control adults and JT1D patients were dominantly Th2 and T regulatory type 1 (Tr1) cells. Notably, the frequency of IGRP-specific Tr1 cells was significantly lower in AT1D patients than in control adults and JT1D patients. In conclusion, our study suggests that IGRP-specific Th cells play a unique pathogenic role in AT1D.
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Affiliation(s)
- Daisuke Chujo
- Baylor Institute for Immunology Research, Dallas, TX, USA; National Center for Global Health and Medicine, Tokyo, Japan
| | | | - Emile Foucat
- Baylor Institute for Immunology Research, Dallas, TX, USA
| | | | | | - Gerald T Nepom
- Benaroya Research Institute at Virginia Mason, Seattle, WA, USA
| | | | - Hideki Ueno
- Baylor Institute for Immunology Research, Dallas, TX, USA.
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Koopman FA, Vosters JL, Roescher N, Broekstra N, Tak PP, Vervoordeldonk MJ. Cholinergic anti-inflammatory pathway in the non-obese diabetic mouse model. Oral Dis 2015; 21:858-65. [DOI: 10.1111/odi.12354] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 05/27/2015] [Accepted: 05/29/2015] [Indexed: 01/03/2023]
Affiliation(s)
- FA Koopman
- Department of Clinical Immunology & Rheumatology; Amsterdam Rheumatology and immunology Center; Academic Medical Center/University of Amsterdam; Amsterdam The Netherlands
| | - JL Vosters
- Department of Clinical Immunology & Rheumatology; Amsterdam Rheumatology and immunology Center; Academic Medical Center/University of Amsterdam; Amsterdam The Netherlands
| | - N Roescher
- Department of Clinical Immunology & Rheumatology; Amsterdam Rheumatology and immunology Center; Academic Medical Center/University of Amsterdam; Amsterdam The Netherlands
| | - N Broekstra
- Department of Clinical Immunology & Rheumatology; Amsterdam Rheumatology and immunology Center; Academic Medical Center/University of Amsterdam; Amsterdam The Netherlands
| | - PP Tak
- Department of Clinical Immunology & Rheumatology; Amsterdam Rheumatology and immunology Center; Academic Medical Center/University of Amsterdam; Amsterdam The Netherlands
- University of Cambridge; Cambridge UK
- Ghent University; Ghent Belgium
- GlaxoSmithKline; Stevenage UK
| | - MJ Vervoordeldonk
- Department of Clinical Immunology & Rheumatology; Amsterdam Rheumatology and immunology Center; Academic Medical Center/University of Amsterdam; Amsterdam The Netherlands
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Fuchs YF, Adler K, Lindner A, Karasinsky A, Wilhelm C, Weigelt M, Balke H, Förtsch K, Mortler-Hildebrandt LF, Harlan DM, Pechhold K, Ziegler AG, Bonifacio E. IGRP and insulin vaccination induce CD8+ T cell-mediated autoimmune diabetes in the RIP-CD80GP mouse. Clin Exp Immunol 2014; 176:199-206. [PMID: 24387268 DOI: 10.1111/cei.12263] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/27/2013] [Indexed: 01/07/2023] Open
Abstract
Autoimmune diabetes is characterized by autoantigen-specific T cell-mediated destruction of pancreatic islet beta cells, and CD8(+) T cells are key players during this process. We assessed whether the bitransgenic RIP-CD80 x RIP-LCMV-GP (RIP-CD80GP) mice may be a versatile antigen-specific model of inducible CD8(+) T cell-mediated autoimmune diabetes. Antigen-encoding DNA, peptide-loaded dendritic cells and antigen plus incomplete Freund's adjuvant were used for vaccination. Of 14 pancreatic proteins tested by DNA vaccination, murine pre-proinsulin 2 (100% of mice; median time after vaccination, 60 days) and islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP) (77%, 58 days) could induce diabetes. Vaccination with DNA encoding for zinc transporter 8, Ia-2, Ia-2β, glutamic acid decarboxylase 67 (Gad67), chromogranin A, insulinoma amyloid polypeptide and homeobox protein Nkx-2.2 induced diabetes development in 25-33% of mice. Vaccination with DNA encoding for Gad65, secretogranin 5, pancreas/duodenum homeobox protein 1 (Pdx1), carboxyl ester lipase, glucagon and control hepatitis B surface antigen (HBsAg) induced diabetes in <20% of mice. Diabetes induction efficiency could be increased by DNA vaccination with a vector encoding a ubiquitin-antigen fusion construct. Diabetic mice had florid T cell islet infiltration. CD8(+) T cell targets of IGRP were identified with a peptide library-based enzyme-linked immunospot assay, and diabetes could also be induced by vaccination with major histocompatibility complex (MHC) class I-restricted IGRP peptides loaded on mature dendritic cells. Vaccination with antigen plus incomplete Freund's adjuvant, which can prevent diabetes in other models, led to rapid diabetes development in the RIP-CD80GP mouse. We conclude that RIP-CD80GP mice are a versatile model of antigen specific autoimmune diabetes and may complement existing mouse models of autoimmune diabetes for evaluating CD8(+) T cell-targeted prevention strategies.
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Affiliation(s)
- Y F Fuchs
- DFG - Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden, Dresden, Germany; Paul Langerhans Institute Dresden-German Center for Diabetes Research (DZD), Dresden, Germany
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Abstract
Type 1A diabetes (autoimmune) is now immunologically predictable in man, but preventable only in animal models. What triggers the development of autoimmunity in genetically susceptible individuals remains unknown. Studies of non-obese diabetic (NOD) mice reveal that interactions between T-cell receptors of diabetogenic T cell and an MHC class II loaded with an autoantigen are key determinates of the disease. With insulin as the primary target in the NOD mouse, likely man, and possibly the RT1-U rat models, therapeutic targeting of the components of these anti-insulin trimolecular complexes we believe provide a fulcrum for development of preventive therapy. In particular for the NOD mouse model, there is extensive evidence that the dominant insulin peptide driving disease initiation is insulin B chain amino acids 9-23 (SHLVEALYLVCGERG) recognized predominantly by germ-line sequences of a specific T-cell receptor Valpha (TRAV5D-4), and small molecules or monoclonal antibodies directed at this recognition complex can prevent diabetes.
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Yang T, Hohenstein AC, Lee CE, Hutton JC, Davidson HW. Mapping I-A(g7) restricted epitopes in murine G6PC2. Immunol Res 2013; 55:91-9. [PMID: 22983906 DOI: 10.1007/s12026-012-8368-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
G6PC2, also known as islet-specific glucose 6-phosphatase catalytic subunit-related protein (IGRP), is a major target of autoreactive CD8(+) T cells in both diabetic human subjects and the non-obese diabetic (NOD) mouse. However, in contrast to the abundant literature regarding the CD8(+) response to this antigen, much less is known about the potential involvement of IGRP-reactive CD4(+) T cells in diabetogenesis. The single previous study that examined this question in NOD mice was based upon a candidate epitope approach and identified three I-A(g7)-restricted epitopes that each elicited spontaneous responses in these animals. However, given the known inaccuracies of MHC class II epitope prediction algorithms, we hypothesized that additional specificities might also be targeted. To address this issue, we immunized NOD mice with membranes from insect cells overexpressing full-length recombinant mouse IGRP and measured recall responses of purified CD4(+) T cells using a library of overlapping peptides encompassing the entire 355-aa primary sequence. Nine peptides representing 8 epitopes gave recall responses, only 1 of which corresponded to any of the previously reported sequences. In each case proliferation was blocked by a monoclonal antibody to I-A(g7), but not the appropriate isotype control. Consistent with a role in diabetogenesis, proliferative responses to 4 of the 9 peptides (3 epitopes) were also detected in CD4(+) T cells purified from the pancreatic draining lymph nodes of pre-diabetic female animals, but not from peripheral lymph nodes or spleens of the same animals. Intriguingly, one of the newly identified spontaneously reactive epitopes (P8 [IGRP(55-72)]) is highly conserved between mice and man, suggesting that it might also be a target of HLA-DQ8-restricted T cells in diabetic human subjects, an hypothesis that we are currently testing.
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Affiliation(s)
- Tao Yang
- Barbara Davis Center for Childhood Diabetes, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
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Multiple roles of glucose-6-phosphatases in pathophysiology. Biochim Biophys Acta Gen Subj 2013; 1830:2608-18. [DOI: 10.1016/j.bbagen.2012.12.013] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Revised: 12/11/2012] [Accepted: 12/13/2012] [Indexed: 12/28/2022]
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Boztug K, Klein C. Genetics and Pathophysiology of Severe Congenital Neutropenia Syndromes Unrelated to Neutrophil Elastase. Hematol Oncol Clin North Am 2013; 27:43-60, vii. [DOI: 10.1016/j.hoc.2012.11.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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