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Weeder BR, Wood MA, Li E, Nellore A, Thompson RF. pepsickle rapidly and accurately predicts proteasomal cleavage sites for improved neoantigen identification. Bioinformatics 2021; 37:3723-3733. [PMID: 34478497 DOI: 10.1093/bioinformatics/btab628] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/21/2021] [Accepted: 08/31/2021] [Indexed: 12/30/2022] Open
Abstract
MOTIVATION Proteasomal cleavage is a key component in protein turnover, as well as antigen processing and presentation. Although tools for proteasomal cleavage prediction are available, they vary widely in their performance, options, and availability. RESULTS Herein we present pepsickle, an open-source tool for proteasomal cleavage prediction with better in vivo prediction performance (AUC) and computational speed than current models available in the field and with the ability to predict sites based on both constitutive and immunoproteasome profiles. Post-hoc filtering of predicted patient neoepitopes using pepsickle significantly enriches for immune-responsive epitopes and may improve current epitope prediction and vaccine development pipelines. AVAILABILITY pepsickle is open source and available at https://github.com/pdxgx/pepsickle. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Benjamin R Weeder
- Computational Biology Program, Oregon Health & Science University, Portland, Oregon, USA.,Department of Biomedical Engineering, Oregon Health & Science University, Portland, Oregon, USA
| | | | - Ellysia Li
- Pacific University, Forest Grove, OR, USA
| | - Abhinav Nellore
- Computational Biology Program, Oregon Health & Science University, Portland, Oregon, USA.,Department of Biomedical Engineering, Oregon Health & Science University, Portland, Oregon, USA.,Department of Surgery, Oregon Health & Science University, Portland, Oregon, USA
| | - Reid F Thompson
- Computational Biology Program, Oregon Health & Science University, Portland, Oregon, USA.,Department of Biomedical Engineering, Oregon Health & Science University, Portland, Oregon, USA.,Department of Radiation Medicine, Oregon Health & Science University, Portland, Oregon, USA.,Department of Medical Informatics and Clinical Epidemiology, Oregon Health & Science University, Portland, Oregon, USA.,Division of Hospital and Specialty Medicine, VA Portland Healthcare System, Portland, Oregon, USA
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2
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Mannering SI, Bhattacharjee P. Insulin's other life: an autoantigen in type 1 diabetes. Immunol Cell Biol 2021; 99:448-460. [PMID: 33524197 DOI: 10.1111/imcb.12442] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 12/21/2020] [Accepted: 01/28/2021] [Indexed: 12/14/2022]
Abstract
One hundred years ago, Frederick Banting, John Macleod, Charles Best and James Collip, and their collaborators, discovered insulin. This discovery paved the way to saving countless lives and ushered in the "Insulin Era." Since the discovery of insulin, we have made enormous strides in understanding its role in metabolism and diabetes. Insulin has played a dramatic role in the treatment of people with diabetes; particularly type 1 diabetes (T1D). Insulin replacement is a life-saving therapy for people with T1D and some with type 2 diabetes. T1D is an autoimmune disease caused by the T-cell-mediated destruction of the pancreatic insulin-producing beta cells that leads to a primary insulin deficiency. It has become increasingly clear that insulin, and its precursors preproinsulin (PPI) and proinsulin (PI), can play another role-not as a hormone but as an autoantigen in T1D. Here we review the role played by the products of the INS gene as autoantigens in people with T1D. From many elegant animal studies, it is clear that T-cell responses to insulin, PPI and PI are essential for T1D to develop. Here we review the evidence that autoimmune responses to insulin and PPI arise in people with T1D and discuss the recently described neoepitopes derived from the products of the insulin gene. Finally, we look forward to new approaches to deliver epitopes derived from PPI, PI and insulin that may allow immune tolerance to pancreatic beta cells to be restored in people with, or at risk of, T1D.
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Affiliation(s)
- Stuart I Mannering
- Immunology and Diabetes Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC, Australia.,Department of Medicine, St. Vincent's Hospital, University of Melbourne, Fitzroy, VIC, Australia
| | - Pushpak Bhattacharjee
- Immunology and Diabetes Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC, Australia
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3
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Ogura H, Preston-Hurlburt P, Perdigoto AL, Amodio M, Krishnaswamy S, Clark P, Yu H, Egli D, Fouts A, Steck AK, Herold KC. Identification and Analysis of Islet Antigen-Specific CD8 + T Cells with T Cell Libraries. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2018; 201:1662-1670. [PMID: 30082321 PMCID: PMC6449153 DOI: 10.4049/jimmunol.1800267] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 07/06/2018] [Indexed: 11/19/2022]
Abstract
Type 1 diabetes (T1D) is most likely caused by killing of β cells by autoreactive CD8+ T cells. Methods to isolate and identify these cells are limited by their low frequency in the peripheral blood. We analyzed CD8+ T cells, reactive with diabetes Ags, with T cell libraries and further characterized their phenotype by CyTOF using class I MHC tetramers. In the libraries, the frequency of islet Ag-specific CD45RO+IFN-γ+CD8+ T cells was higher in patients with T1D compared with healthy control subjects. Ag-specific cells from the libraries of patients with T1D were reactive with ZnT8186-194, whereas those from healthy control recognized ZnT8186-194 and other Ags. ZnT8186-194-reactive CD8+ cells expressed an activation phenotype in T1D patients. We found TCR sequences that were used in multiple library wells from patients with T1D, but these sequences were private and not shared between individuals. These sequences could identify the Ag-specific T cells on a repeated draw, ex vivo in the IFN-γ+ CD8+ T cell subset. We conclude that CD8+ T cell libraries can identify Ag-specific T cells in patients with T1D. The T cell clonotypes can be tracked in vivo with identification of the TCR gene sequences.
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Affiliation(s)
- Hideki Ogura
- Department of Immunobiology, Yale University, New Haven, CT 06520
| | | | | | - Matthew Amodio
- Department of Genetics and of Computer Science, Yale University, New Haven, CT 06520
| | - Smita Krishnaswamy
- Department of Genetics and of Computer Science, Yale University, New Haven, CT 06520
| | - Pamela Clark
- Department of Immunobiology, Yale University, New Haven, CT 06520
| | - Hua Yu
- Department of Immunobiology, Yale University, New Haven, CT 06520
| | - Dieter Egli
- Naomi Berrie Diabetes Center, Division of Molecular Genetics, Columbia University, New York, NY 10032
| | - Alexandra Fouts
- Barbara Davis Center for Childhood Diabetes, University of Colorado School of Medicine, Aurora, CO 80045
| | - Andrea K Steck
- Barbara Davis Center for Childhood Diabetes, University of Colorado School of Medicine, Aurora, CO 80045
| | - Kevan C Herold
- Department of Immunobiology, Yale University, New Haven, CT 06520;
- Department of Internal Medicine, Yale University, New Haven, CT 06520
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4
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A dual-function epidermal growth factor receptor pathway substrate 8 (Eps8)-derived peptide exhibits a potent cytotoxic T lymphocyte-activating effect and a specific inhibitory activity. Cell Death Dis 2018. [PMID: 29515106 PMCID: PMC5841361 DOI: 10.1038/s41419-018-0420-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The identification and characterization of tumor-associated antigens (TAAs) that generate specific cytotoxic T lymphocytes (CTLs) are vital to the development of cancer immunotherapy. The epidermal growth factor receptor (EGFR) pathway substrate 8 gene (Eps8) is involved in regulating cancer progression and might be an ideal antigen. In this study, we searched for novel human leukocyte antigen (HLA)-A*2402-restricted epitopes derived from the Eps8 protein via the HLA-binding prediction algorithm. Among four candidates, peptides 327 (EFLDCFQKF), 534 (KYAKSKYDF) and 755 (LFSLNKDEL) induced peptide-specific CTLs to secrete higher levels of interferon-gamma (IFN-γ) and showed enhanced cytotoxic activity against malignant cancer cells. Our results demonstrated that peptide-specific CTLs showed effective antitumor responses, including upregulation of interleukin-2 (IL-2), tumor necrosis factor-alpha (TNF-α), granzyme B and perforin. Treatment with peptide-sensitized peripheral blood mononuclear cells (PBMCs) significantly reduced the tumor growth in vivo compared with the non-peptide-sensitized PBMC treatment. Importantly, our results indicated that peptide 327 may interfere with EGFR signaling by mechanistically disrupting Eps8/EGFR complex formation. We extended this observation that peptide 327 also suppressed the viability of cancer cells, blocked EGFR signal pathway and reduced the expression of downstream targets. Notably, conjugation of peptide 327 to the TAT sequence (TAT-327) resulted in potent antitumor activity and selective insertion into cancer cell membranes, where it adopted a punctate distribution. Furthermore, peptide 327 and TAT-327 displayed anticancer properties in xenograft models. Our results indicated that 327, 534 and 755 were novel HLA-A*2402-restricted epitopes from Eps8. By inhibiting the Eps8/EGFR interaction, peptide 327 and TAT-327 may serve as novel peptide inhibitors, which could provide an innovative approach for treating various cancers.
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Abstract
Type 1 diabetes (T1D) is a chronic autoimmune disease that causes severe loss of pancreatic β cells. Autoreactive T cells are key mediators of β cell destruction. Studies of organ donors with T1D that have examined T cells in pancreas, the diabetogenic insulitis lesion, and lymphoid tissues have revealed a broad repertoire of target antigens and T cell receptor (TCR) usage, with initial evidence of public TCR sequences that are shared by individuals with T1D. Neoepitopes derived from post-translational modifications of native antigens are emerging as novel targets that are more likely to evade self-tolerance. Further studies will determine whether T cell responses to neoepitopes are major disease drivers that could impact prediction, prevention, and therapy. This Review provides an overview of recent progress in our knowledge of autoreactive T cells that has emerged from experimental and clinical research as well as pathology investigations.
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Fishman S, Lewis MD, Siew LK, De Leenheer E, Kakabadse D, Davies J, Ziv D, Margalit A, Karin N, Gross G, Wong FS. Adoptive Transfer of mRNA-Transfected T Cells Redirected against Diabetogenic CD8 T Cells Can Prevent Diabetes. Mol Ther 2017; 25:456-464. [PMID: 28109957 DOI: 10.1016/j.ymthe.2016.12.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 12/05/2016] [Accepted: 12/05/2016] [Indexed: 11/29/2022] Open
Abstract
Chimeric major histocompatibility complex (MHC) molecules supplemented with T cell receptor (TCR) signaling motifs function as activation receptors and can redirect gene-modified T cells against pathogenic CD8 T cells. We have shown that β2 microglobulin (β2m) operates as a universal signaling component of MHC-I molecules when fused with the CD3-ζ chain. Linking the H-2Kd-binding insulin B chain peptide insulin B chain, amino acids 15-23 (InsB15-23) to the N terminus of β2m/CD3-ζ, redirected polyclonal CD8 T cells against pathogenic CD8 T cells in a peptide-specific manner in the non-obese diabetic (NOD) mouse. Here, we describe mRNA electroporation for delivering peptide/β2m/CD3-ζ genes to a reporter T cell line and purified primary mouse CD8 T cells. The peptide/β2m/CD3-ζ products paired with endogenous MHC-I chains and transmitted strong activation signals upon MHC-I cross-linking. The reporter T cell line transfected with InsB15-23/β2m/CD3-ζ mRNA was activated by an InsB15-23-H-2Kd-specific CD8 T cell hybrid only when the transfected T cells expressed H-2Kd. Primary NOD CD8 T cells expressing either InsB15-23/β2m/CD3-ζ or islet-specific glucose-6-phosphatase catalytic subunit-related protein, amino acids 206-214 (IGRP206-214)/β2m/CD3-ζ killed their respective autoreactive CD8 T cell targets in vitro. Furthermore, transfer of primary CD8 T cells transfected with InsB15-23/β2m/CD3-ζ mRNA significantly reduced insulitis and protected NOD mice from diabetes. Our results demonstrate that mRNA encoding chimeric MHC-I receptors can redirect effector CD8 against diabetogenic CD8 T cells, offering a new approach for the treatment of type 1 diabetes.
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Affiliation(s)
- Sigal Fishman
- Laboratory of Immunology, MIGAL - Galilee Research Institute, Kiryat Shmona 11016, Israel; Department of Immunology, Rappaport Family Institute for Research in the Medical Sciences, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa 3525433, Israel
| | - Mark D Lewis
- Diabetes Research Group, Division of Infection and Immunity, Cardiff University School of Medicine, Cardiff University, Cardiff CF14 4XN, UK
| | - L Khai Siew
- Diabetes Research Group, Division of Infection and Immunity, Cardiff University School of Medicine, Cardiff University, Cardiff CF14 4XN, UK
| | - Evy De Leenheer
- Diabetes Research Group, Division of Infection and Immunity, Cardiff University School of Medicine, Cardiff University, Cardiff CF14 4XN, UK
| | - Dimitri Kakabadse
- Diabetes Research Group, Division of Infection and Immunity, Cardiff University School of Medicine, Cardiff University, Cardiff CF14 4XN, UK
| | - Joanne Davies
- Diabetes Research Group, Division of Infection and Immunity, Cardiff University School of Medicine, Cardiff University, Cardiff CF14 4XN, UK
| | - Doron Ziv
- Laboratory of Immunology, MIGAL - Galilee Research Institute, Kiryat Shmona 11016, Israel; Department of Biotechnology, Tel-Hai College, Upper Galilee 12210, Israel
| | - Alon Margalit
- Laboratory of Immunology, MIGAL - Galilee Research Institute, Kiryat Shmona 11016, Israel; Department of Biotechnology, Tel-Hai College, Upper Galilee 12210, Israel
| | - Nathan Karin
- Department of Immunology, Rappaport Family Institute for Research in the Medical Sciences, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa 3525433, Israel
| | - Gideon Gross
- Laboratory of Immunology, MIGAL - Galilee Research Institute, Kiryat Shmona 11016, Israel; Department of Biotechnology, Tel-Hai College, Upper Galilee 12210, Israel.
| | - F Susan Wong
- Diabetes Research Group, Division of Infection and Immunity, Cardiff University School of Medicine, Cardiff University, Cardiff CF14 4XN, UK
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7
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Gorasia DG, Dudek NL, Safavi-Hemami H, Perez RA, Schittenhelm RB, Saunders PM, Wee S, Mangum JE, Hubbard MJ, Purcell AW. A prominent role of PDIA6 in processing of misfolded proinsulin. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2016; 1864:715-723. [PMID: 26947243 DOI: 10.1016/j.bbapap.2016.03.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 02/22/2016] [Accepted: 03/02/2016] [Indexed: 11/17/2022]
Abstract
Despite its critical role in maintaining glucose homeostasis, surprisingly little is known about proinsulin folding in the endoplasmic reticulum. In this study we aimed to understand the chaperones involved in the maturation and degradation of proinsulin. We generated pancreatic beta cell lines expressing FLAG-tagged proinsulin. Several chaperones (including BiP, PDIA6, calnexin, calreticulin, GRP170, Erdj3 and ribophorin II) co-immunoprecipitated with proinsulin suggesting a role for these proteins in folding. To investigate the chaperones responsible for targeting misfolded proinsulin for degradation, we also created a beta cell line expressing FLAG-tagged proinsulin carrying the Akita mutation (Cys96Tyr). All chaperones found to be associated with wild type proinsulin also co-immunoprecipitated with Akita proinsulin. However, one additional protein, namely P58(IPK), specifically precipitated with Akita proinsulin and approximately ten fold more PDIA6, but not other PDI family members, was bound to Akita proinsulin. The latter suggests that PDIA6 may act as a key reductase and target misfolded proinsulin to the ER-degradation pathway. The preferential association of PDIA6 to Akita proinsulin was also confirmed in another beta cell line (βTC-6). Furthermore, for the first time, a physiologically relevant substrate for PDIA6 has been evidenced. Thus, this study has identified several chaperones/foldases that associated with wild type proinsulin and has also provided a comprehensive interactome for Akita misfolded proinsulin.
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Affiliation(s)
- Dhana G Gorasia
- Department of Biochemistry and Molecular Biology, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, Australia
| | - Nadine L Dudek
- Department of Biochemistry and Molecular Biology, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, Australia; Infection and Immunity Program, Biomolecular Discovery Institute and Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria, Australia
| | - Helena Safavi-Hemami
- Department of Biochemistry and Molecular Biology, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, Australia
| | - Rochelle Ayala Perez
- Infection and Immunity Program, Biomolecular Discovery Institute and Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria, Australia
| | - Ralf B Schittenhelm
- Infection and Immunity Program, Biomolecular Discovery Institute and Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria, Australia
| | - Philippa M Saunders
- Department of Microbiology and Immunology, The University of Melbourne, Parkville, Victoria, Australia
| | - Sheena Wee
- Department of Biochemistry and Molecular Biology, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, Australia
| | - Jon E Mangum
- Department of Pharmacology and Therapeutics, The University of Melbourne, Melbourne, Victoria, Australia
| | - Michael J Hubbard
- Department of Pharmacology and Therapeutics, The University of Melbourne, Melbourne, Victoria, Australia; Department of Paediatrics, The University of Melbourne, Melbourne, Victoria, Australia
| | - Anthony W Purcell
- Department of Biochemistry and Molecular Biology, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, Australia; Infection and Immunity Program, Biomolecular Discovery Institute and Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria, Australia.
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8
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Major histocompatibility complex linked databases and prediction tools for designing vaccines. Hum Immunol 2015; 77:295-306. [PMID: 26585361 DOI: 10.1016/j.humimm.2015.11.012] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 08/29/2015] [Accepted: 11/09/2015] [Indexed: 12/19/2022]
Abstract
Presently, the major histocompatibility complex (MHC) is receiving considerable interest owing to its remarkable role in antigen presentation and vaccine design. The specific databases and prediction approaches related to MHC sequences, structures and binding/nonbinding peptides have been aggressively developed in the past two decades with their own benchmarks and standards. Before using these databases and prediction tools, it is important to analyze why and how the tools are constructed along with their strengths and limitations. The current review presents insights into web-based immunological bioinformatics resources that include searchable databases of MHC sequences, epitopes and prediction tools that are linked to MHC based vaccine design, including population coverage analysis. In T cell epitope forecasts, MHC class I binding predictions are very accurate for most of the identified MHC alleles. However, these predictions could be further improved by integrating proteasome cleavage (in conjugation with transporter associated with antigen processing (TAP) binding) prediction, as well as T cell receptor binding prediction. On the other hand, MHC class II restricted epitope predictions display relatively low accuracy compared to MHC class I. To date, pan-specific tools have been developed, which not only deliver significantly improved predictions in terms of accuracy, but also in terms of the coverage of MHC alleles and supertypes. In addition, structural modeling and simulation systems for peptide-MHC complexes enable the molecular-level investigation of immune processes. Finally, epitope prediction tools, and their assessments and guidelines, have been presented to immunologist for the design of novel vaccine and diagnostics.
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Xu X, Gu Y, Bian L, Shi Y, Cai Y, Chen Y, Chen H, Qian L, Wu X, Xu K, Mallone R, Davidson HW, Yu L, She J, Zhang M, Yang T. Characterization of immune response to novel HLA-A2-restricted epitopes from zinc transporter 8 in type 1 diabetes. Vaccine 2015; 34:854-62. [PMID: 26541133 DOI: 10.1016/j.vaccine.2015.10.108] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Revised: 10/19/2015] [Accepted: 10/26/2015] [Indexed: 11/17/2022]
Abstract
OBJECTIVE ZnT8-specific CD8+ T cells in human type 1 diabetes (T1D) have been reported recently, although the results from different laboratories are inconsistent. We aimed to characterize these ZnT8 specific CD8+ T cells and validate assays to screen peptide libraries. METHODS We screened HLA-A2-restricted T cell candidate peptides of ZnT8 with different methods including computer algorithms, MHC-peptide binding and dissociation assays in T2 cell line, identification in HLA-A2 transgenic (Tg) mice and in vivo CTL assays. Then ELISpot assay was used to measure peptide-reactive T cell responses in 49 HLA-A2-restricted T1D patients. RESULTS We demonstrated that ZnT8(107-116)(115), ZnT8(110-118), and ZnT8(177-186) were novel HLA-A*0201-restricted CTL epitopes in T1D patients. ZnT8(107-116)(115), ZnT8(115-123), ZnT8(153-161), ZnT8(177-186) and ZnT8(291-300) represent potentially major biomarkers for T1D. T cell responses against these epitopes showed different distributions between recently diagnosed and long-standing patients. Furthermore, they displayed discriminating performance among different ethnicities. We also compared the performance of the epitope identification strategies used herein. The epitopes which exhibited strong immunogenicity in HLA-A2 Tg mice were also well recognized by T1D patients. CONCLUSIONS The differences in autoimmune T cell responses among T1D individuals may open new avenues toward T1D prediction and prevention. It also provides efficient strategies for immune intervention.
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Affiliation(s)
- Xinyu Xu
- Department of Endocrinology, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu, China
| | - Yong Gu
- Department of Endocrinology, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu, China
| | - Lingling Bian
- Department of Endocrinology, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu, China
| | - Yun Shi
- Department of Endocrinology, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu, China
| | - Yun Cai
- Department of Endocrinology, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu, China
| | - Yang Chen
- Department of Endocrinology, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu, China
| | - Heng Chen
- Department of Endocrinology, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu, China
| | - Li Qian
- Department of Endocrinology, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu, China
| | - Xiangmei Wu
- Department of Endocrinology, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu, China
| | - Kuanfeng Xu
- Department of Endocrinology, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu, China
| | - Roberto Mallone
- INSERM, U1016, Cochin Institute, Paris, France; CNRS, UMR8104, Cochin Institute, Paris, France; Paris Descartes University, Sorbonne Paris Cité, Paris, France; Assistance Publique Hôpitaux de Paris, Dept. of Diabetology, Cochin Hospital, Paris, France
| | - Howard W Davidson
- Department of Barbara Davis Center for Childhood Diabetes, University of Colorado at Denver and Health Sciences Center, USA
| | - Liping Yu
- Department of Barbara Davis Center for Childhood Diabetes, University of Colorado at Denver and Health Sciences Center, USA
| | - Jinxiong She
- Department of Endocrinology, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu, China; Center for Biotechnology and Genomic Medicine, Medical College of Georgia, Georgia Regents University, Augusta, GA, USA
| | - Mei Zhang
- Department of Endocrinology, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu, China.
| | - Tao Yang
- Department of Endocrinology, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu, China
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10
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Pearson JA, Wong FS, Wen L. The importance of the Non Obese Diabetic (NOD) mouse model in autoimmune diabetes. J Autoimmun 2015; 66:76-88. [PMID: 26403950 DOI: 10.1016/j.jaut.2015.08.019] [Citation(s) in RCA: 180] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 08/26/2015] [Indexed: 02/06/2023]
Abstract
Type 1 Diabetes (T1D) is an autoimmune disease characterized by the pancreatic infiltration of immune cells resulting in T cell-mediated destruction of the insulin-producing beta cells. The successes of the Non-Obese Diabetic (NOD) mouse model have come in multiple forms including identifying key genetic and environmental risk factors e.g. Idd loci and effects of microorganisms including the gut microbiota, respectively, and how they may contribute to disease susceptibility and pathogenesis. Furthermore, the NOD model also provides insights into the roles of the innate immune cells as well as the B cells in contributing to the T cell-mediated disease. Unlike many autoimmune disease models, the NOD mouse develops spontaneous disease and has many similarities to human T1D. Through exploiting these similarities many targets have been identified for immune-intervention strategies. Although many of these immunotherapies did not have a significant impact on human T1D, they have been shown to be effective in the NOD mouse in early stage disease, which is not equivalent to trials in newly-diagnosed patients with diabetes. However, the continued development of humanized NOD mice would enable further clinical developments, bringing T1D research to a new translational level. Therefore, it is the aim of this review to discuss the importance of the NOD model in identifying the roles of the innate immune system and the interaction with the gut microbiota in modifying diabetes susceptibility. In addition, the role of the B cells will also be discussed with new insights gained through B cell depletion experiments and the impact on translational developments. Finally, this review will also discuss the future of the NOD mouse and the development of humanized NOD mice, providing novel insights into human T1D.
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Affiliation(s)
- James A Pearson
- Section of Endocrinology, School of Medicine, Yale University, New Haven, CT, USA
| | - F Susan Wong
- Diabetes Research Group, Institute of Molecular & Experimental Medicine, School of Medicine, Cardiff University, Wales, UK
| | - Li Wen
- Section of Endocrinology, School of Medicine, Yale University, New Haven, CT, USA.
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11
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Hsu HT, Janßen L, Lawand M, Kim J, Perez-Arroyo A, Culina S, Gdoura A, Burgevin A, Cumenal D, Fourneau Y, Moser A, Kratzer R, Wong FS, Springer S, van Endert P. Endoplasmic reticulum targeting alters regulation of expression and antigen presentation of proinsulin. THE JOURNAL OF IMMUNOLOGY 2014; 192:4957-66. [PMID: 24778449 DOI: 10.4049/jimmunol.1300631] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Peptide ligands presented by MHC class I (MHC-I) molecules are produced by degradation of cytosolic and nuclear, but also endoplasmic reticulum (ER)-resident, proteins by the proteasome. However, Ag processing of ER proteins remains little characterized. Studying processing and presentation of proinsulin, which plays a pivotal role in autoimmune diabetes, we found that targeting to the ER has profound effects not only on how proinsulin is degraded, but also on regulation of its cellular levels. While proteasome inhibition inhibited degradation and presentation of cytosolic proinsulin, as expected, it reduced the abundance of ER-targeted proinsulin. This targeting and protein modifications modifying protein half-life also had profound effects on MHC-I presentation and proteolytic processing of proinsulin. Thus, presentation of stable luminal forms was inefficient but enhanced by proteasome inhibition, whereas that of unstable luminal forms and of a cytosolic form were more efficient and compromised by proteasome inhibitors. Distinct stability of peptide MHC complexes produced from cytosolic and luminal proinsulin suggests that different proteolytic activities process the two Ag forms. Thus, both structural features and subcellular targeting of Ags can have strong effects on the processing pathways engaged by MHC-I-restricted Ags, and on the efficiency and regulation of their presentation.
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Affiliation(s)
- Hsiang-Ting Hsu
- INSERM, Unité 1151, 75015 Paris, France; Centre National de la Recherche Scientifique, Unité 8253, 75015 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, 75015 Paris, France
| | - Linda Janßen
- Biochemistry and Cell Biology, Molecular Life Science Center, Jacobs University Bremen, 28759 Bremen, Germany; and
| | - Myriam Lawand
- INSERM, Unité 1151, 75015 Paris, France; Centre National de la Recherche Scientifique, Unité 8253, 75015 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, 75015 Paris, France
| | - Jessica Kim
- INSERM, Unité 1151, 75015 Paris, France; Centre National de la Recherche Scientifique, Unité 8253, 75015 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, 75015 Paris, France
| | - Alicia Perez-Arroyo
- INSERM, Unité 1151, 75015 Paris, France; Centre National de la Recherche Scientifique, Unité 8253, 75015 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, 75015 Paris, France
| | - Slobodan Culina
- INSERM, Unité 1151, 75015 Paris, France; Centre National de la Recherche Scientifique, Unité 8253, 75015 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, 75015 Paris, France
| | - Abdel Gdoura
- INSERM, Unité 1151, 75015 Paris, France; Centre National de la Recherche Scientifique, Unité 8253, 75015 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, 75015 Paris, France
| | - Anne Burgevin
- INSERM, Unité 1151, 75015 Paris, France; Centre National de la Recherche Scientifique, Unité 8253, 75015 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, 75015 Paris, France
| | - Delphine Cumenal
- INSERM, Unité 1151, 75015 Paris, France; Centre National de la Recherche Scientifique, Unité 8253, 75015 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, 75015 Paris, France
| | - Yousra Fourneau
- INSERM, Unité 1151, 75015 Paris, France; Centre National de la Recherche Scientifique, Unité 8253, 75015 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, 75015 Paris, France
| | - Anna Moser
- INSERM, Unité 1151, 75015 Paris, France; Centre National de la Recherche Scientifique, Unité 8253, 75015 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, 75015 Paris, France
| | - Roland Kratzer
- INSERM, Unité 1151, 75015 Paris, France; Centre National de la Recherche Scientifique, Unité 8253, 75015 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, 75015 Paris, France
| | - F Susan Wong
- Centre for Endocrine and Diabetes Science, Cardiff University School of Medicine, Cardiff CF14 4XN, United Kingdom
| | - Sebastian Springer
- Biochemistry and Cell Biology, Molecular Life Science Center, Jacobs University Bremen, 28759 Bremen, Germany; and
| | - Peter van Endert
- INSERM, Unité 1151, 75015 Paris, France; Centre National de la Recherche Scientifique, Unité 8253, 75015 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, 75015 Paris, France;
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Culina S, Mauvais FX, Hsu HT, Burgevin A, Guénette S, Moser A, van Endert P. No major role for insulin-degrading enzyme in antigen presentation by MHC molecules. PLoS One 2014; 9:e88365. [PMID: 24516642 PMCID: PMC3917890 DOI: 10.1371/journal.pone.0088365] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 01/06/2014] [Indexed: 12/27/2022] Open
Abstract
Antigen presentation by MHC class I molecules requires degradation of epitope source proteins in the cytosol. Although the preeminent role of the proteasome is clearly established, evidence suggesting a significant role for proteasome-independent generation of class I ligands has been reported repeatedly. However, an enzyme responsible for such a role has not been identified. Recently insulin-degrading enzyme (IDE) was shown to produce an antigenic peptide derived from the tumor antigen MAGE-A3 in an entirely proteasome-independent manner, raising the question of the global impact of IDE in MHC class I antigen processing. Here we report that IDE knockdown in human cell lines, or knockout in two different mouse strains, has no effect on cell surface expression of various MHC class I molecules, including allomorphs such as HLA-A3 and HLA-B27 suggested to be loaded in an at least a partly proteasome-independent manner. Moreover, reduced or absent IDE expression does not affect presentation of five epitopes including epitopes derived from beta amyloid and proinsulin, two preferred IDE substrates. Thus, IDE does not play a major role in MHC class I antigen processing, confirming the dominant and almost exclusive role of the proteasome in cytosolic production of MHC class I ligands.
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Affiliation(s)
- Slobodan Culina
- Institut National de la Santé et de la Recherche Médicale, Unité 1013, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine Paris Descartes, Paris, France
| | - François-Xavier Mauvais
- Institut National de la Santé et de la Recherche Médicale, Unité 1013, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine Paris Descartes, Paris, France
| | - Hsiang-Ting Hsu
- Institut National de la Santé et de la Recherche Médicale, Unité 1013, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine Paris Descartes, Paris, France
| | - Anne Burgevin
- Institut National de la Santé et de la Recherche Médicale, Unité 1013, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine Paris Descartes, Paris, France
| | - Suzanne Guénette
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Charlestown, Massachusetts, United States of America
| | - Anna Moser
- Institut National de la Santé et de la Recherche Médicale, Unité 1013, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine Paris Descartes, Paris, France
| | - Peter van Endert
- Institut National de la Santé et de la Recherche Médicale, Unité 1013, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine Paris Descartes, Paris, France
- * E-mail:
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Monoclonal antibody blocking the recognition of an insulin peptide-MHC complex modulates type 1 diabetes. Proc Natl Acad Sci U S A 2014; 111:2656-61. [PMID: 24550292 DOI: 10.1073/pnas.1323436111] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The primary autoantigen triggering spontaneous type 1 diabetes mellitus in nonobese diabetic (NOD) mice is insulin. The major T-cell insulin epitope lies within the amino acid 9-23 peptide of the β-chain (B:9-23). This peptide can bind within the peptide binding groove of the NOD MHC class II molecule (MHCII), IA(g7), in multiple positions or "registers." However, the majority of pathogenic CD4 T cells recognize this complex only when the insulin peptide is bound in register 3 (R3). We hypothesized that antibodies reacting specifically with R3 insulin-IA(g7) complexes would inhibit autoimmune diabetes specifically without interfering with recognition of other IA(g7)-presented antigens. To test this hypothesis, we generated a monoclonal antibody (mAb287), which selectively binds to B:9-23 and related variants when presented by IA(g7) in R3, but not other registers. The monoclonal antibody blocks binding of IA(g7)-B:10-23 R3 tetramers to cognate T cells and inhibits T-cell responses to soluble B:9-23 peptides and NOD islets. However, mAb287 has no effect on recognition of other peptides bound to IA(g7) or other MHCII molecules. Intervention with mAb287, but not irrelevant isotype matched antibody, at either early or late stages of disease development, significantly delayed diabetes onset by inhibiting infiltration by not only insulin-specific CD4 T cells, but also by CD4 and CD8 T cells of other specificities. We propose that peptide-MHC-specific monoclonal antibodies can modulate autoimmune disease without the pleiotropic effects of nonselective reagents and, thus, could be applicable to the treatment of multiple T-cell mediated autoimmune disorders.
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Abstract
Type 1 diabetes (T1D) represents 10 to 15% of all forms of diabetes. Its incidence shows a consistent rise in all countries under survey. Evidence for autoimmunity in human T1D relies on the detection of insulitis, of islet cell antibodies, of activated β-cell-specific T lymphocytes and on the association of T1D with a restricted set of class II major histocompatibility complex (MHC) alleles. However, mechanisms that initiate the failure of immune tolerance to β-cell autoantigens remain elusive in common forms of T1D. T1D commonly develop as a multifactorial disease in which environmental factors concur with a highly multigenic background. The disease is driven by the activation of T-lymphocytes against pancreatic β-cells. Several years elapse between initial triggering of the autoimmune response to β cells, as evidenced by the appearance or islet cell autoantibodies, and the onset of clinical diabetes, defining a prediabetes stage. Active mechanisms hold back autoreactive effector T-cells in prediabetes, in particular a subset of CD4+ T-cells (T(reg)) and other regulatory T-cells, such as invariant NKT cells. There is evidence in experimental models that systemic or local infections can trigger autoimmune reactions to β-cells. However, epidemiological observations that have accumulated over years have failed to identify undisputable environmental factors that trigger T1D. Moreover, multiple environmental factors may intervene in the disease evolution and protective as weel as triggering environmental factors may be involved. Available models also indicate that local signals within the islets are required for full-blown diabetes to develop. Many autoantigens that are expressed by β-cells but also by the other endocrine islet cells and by neurons are recognized by lymphocytes along the development of T1D. The immune image of β-cells is that of native components of the β-cell membrane, as seen by B-lymphocytes, and of fragments of intracellular β-cell proteins in the form of peptides loaded onto class I MHC molecules on the β-cell surface and class I and class II molecules onto professional antigen presenting cells. Given the key role of T lymphocytes in T1D, the cartography of autoantigen-derived peptides that are presented to class I-restricted CD8(+) T-cells and class II-restricted CD4(+) T-cells is of outmost importance and is a necessary step in the development of diagnostic T-cell assays and of immunotherapy of T1D.
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Kanatsuna N, Papadopoulos GK, Moustakas AK, Lenmark Å. Etiopathogenesis of insulin autoimmunity. ANATOMY RESEARCH INTERNATIONAL 2012; 2012:457546. [PMID: 22567309 PMCID: PMC3335545 DOI: 10.1155/2012/457546] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Accepted: 01/12/2012] [Indexed: 12/12/2022]
Abstract
Autoimmunity against pancreatic islet beta cells is strongly associated with proinsulin, insulin, or both. The insulin autoreactivity is particularly pronounced in children with young age at onset of type 1 diabetes. Possible mechanisms for (pro)insulin autoimmunity may involve beta-cell destruction resulting in proinsulin peptide presentation on HLA-DR-DQ Class II molecules in pancreatic draining lymphnodes. Recent data on proinsulin peptide binding to type 1 diabetes-associated HLA-DQ2 and -DQ8 is reviewed and illustrated by molecular modeling. The importance of the cellular immune reaction involving cytotoxic CD8-positive T cells to kill beta cells through Class I MHC is discussed along with speculations of the possible role of B lymphocytes in presenting the proinsulin autoantigen over and over again through insulin-carrying insulin autoantibodies. In contrast to autoantibodies against other islet autoantigens such as GAD65, IA-2, and ZnT8 transporters, it has not been possible yet to standardize the insulin autoantibody test. As islet autoantibodies predict type 1 diabetes, it is imperative to clarify the mechanisms of insulin autoimmunity.
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Affiliation(s)
- Norio Kanatsuna
- Department of Clinical Sciences, Skåne University Hospital (SUS), Lund University, CRC Ing 72 Building 91:10, 205 02 Malmö, Sweden
| | - George K. Papadopoulos
- Laboratory of Biochemistry and Biophysics, Faculty of Agricultural Technology, Technological Educational Institute of Epirus, 47100 Arta, Greece
| | - Antonis K. Moustakas
- Department of Organic Farming, Technological Educational Institute of Ionian Islands, 27100 Argostoli, Greece
| | - Åke Lenmark
- Department of Clinical Sciences, Skåne University Hospital (SUS), Lund University, CRC Ing 72 Building 91:10, 205 02 Malmö, Sweden
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Wu X, Xu X, Gu R, Wang Z, Chen H, Xu K, Zhang M, Hutton J, Yang T. Prediction of HLA class I-restricted T-cell epitopes of islet autoantigen combined with binding and dissociation assays. Autoimmunity 2012; 45:176-85. [PMID: 22260783 DOI: 10.3109/08916934.2011.622014] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Identification of cognate peptides recognized by human leucocyte antigen (HLA)/T cell receptor (TCR) complex provides insight into the pathogenic process of type 1 diabetes (T1D). We hypothesize that HLA-binding assays alone are inadequate metrics for the affinity of peptides. Zinc transporter-8 (ZnT8) has emerged in recent years as a novel, major, human autoantigen. Therefore, we aim to identify the HLA-A2-restricted ZnT8 epitopes using both binding and dissociation assays. HLA class I peptide affinity algorithms were used to predict candidate ZnT8 peptides that bind to HLA-A2. We analyzed 15 reported epitopes of seven β-cell candidate autoantigens and eight predicted candidate ZnT8 peptides using binding and dissociation assays. Using IFN-γ ELISpot assay, we tested peripheral blood mononuclear cells (PBMCs) from recent-onset T1D patients and healthy controls for reactivity to seven reported epitopes and eight candidate ZnT8 peptides directly ex vivo. We found five of seven recently reported epitopes in Chinese T1D patients. Of the eight predicted ZnT8 peptides, ZnT8(153-161) had a strong binding affinity and the lowest dissociation rate to HLA-A*0201. We identified it as a novel HLA-A*0201-restricted T-cell epitope in three of eight T1D patients. We conclude that ZnT8(153-161) is a novel HLA-A*0201-restricted T-cell epitope. We did not observe a significant correlation (P = 0.3, R = - 0.5) between cytotoxic T cell (CTL) response and peptide/HLA*0201 complex stability. However, selection of peptides based on affinity and their dissociation rate may be helpful for the identification of candidate CTL epitopes. Thus, we can minimize the number of experiments for the identification of T-cell epitopes from interesting antigens.
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Affiliation(s)
- Xiangmei Wu
- Department of Endocrinology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
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Mallone R, Scotto M, Janicki CN, James EA, Fitzgerald-Miller L, Wagner R, Gottlieb P, Thorpe J, Jospe N, Durinovic-Bellò I, Boitard C, Lou O, Dayan CM, Wong FS. Immunology of Diabetes Society T-Cell Workshop: HLA class I tetramer-directed epitope validation initiative T-Cell Workshop Report-HLA Class I Tetramer Validation Initiative. Diabetes Metab Res Rev 2011; 27:720-6. [PMID: 22069251 DOI: 10.1002/dmrr.1243] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
BACKGROUND Identification of T-cell reactivity to β-cell antigen epitopes is an important goal for studying pathogenesis and for designing and monitoring of immunotherapeutic interventions in type 1 diabetes (T1D). METHODS We performed a multicentre validation of known human leukocyte antigen (HLA) class I CD8+ T-cell epitopes. To this end, peripheral blood T-cell responses were measured in 35 recently (<2 years) diagnosed HLA-A*02:01+ T1D patients using blind-coded HLA-A2 tetramers (TMrs) and pentamers (PMrs), encompassing two epitopes of preproinsulin (PPI; PPIA12-20 and PPIB10-18) and two epitopes of glutamic acid decarboxylase (GAD; GAD114-122 and GAD536-545). We also compared the readout of TMrs and PMrs with a CD8+ T-cell interferon-γ enzyme-linked immunospot assay. RESULTS Despite the minute frequencies of autoreactive cells detected by TMrs/PMrs, most (73-77%) T1D patients had responses to one or more of the epitopes used. All four epitopes were recognized by T1D patients, with a prevalence ranging from 5 to 25%. TMrs and PMrs detected more positive responses to the β-cell epitopes than CD8+ T-cell interferon-γ enzyme-linked immunospot. However, concordance between positive responses to TMrs and PMrs was limited. CONCLUSIONS Using a multicentre blind-coded setup and three different T-cell assays, we have validated PPI and GAD epitopes as commonly recognized CD8+ T-cell targets in recently diagnosed T1D patients. Both TMrs and PMrs showed higher detection sensitivity than the CD8+ T-cell interferon-γ enzyme-linked immunospot assay. However, there are some important methodological issues that need to be addressed in using these sensitive techniques for detecting low frequency responses.
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Affiliation(s)
- R Mallone
- INSERM U986, DeAR Lab Avenir, Saint Vincent de Paul Hospital, and Paris Descartes University, Paris, France.
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Zhang L, Stadinski BD, Michels A, Kappler JW, Eisenbarth GS. Immunization with an insulin peptide-MHC complex to prevent type 1 diabetes of NOD mice. Diabetes Metab Res Rev 2011; 27:784-9. [PMID: 22069260 DOI: 10.1002/dmrr.1252] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BACKGROUND Mutating the insulin B:9-23 peptide prevents diabetes in NOD mice. Thus, the trimolecular complex of I-Ag7-insulin B:9-23 peptide-TCR may be essential for the development of spontaneous diabetes. Pathogenic T cells recognize the B:9-23 peptide presented by I-Ag7 in what is termed register 3, with the B22 basic amino acid (arginine) of the peptide bound in pocket 9 of I-Ag7. Our hypothesis is that immunization with an insulin B:12-22 peptide linked to I-Ag7 in register 3 (I-Ag7-B:RE#3 complex) can induce specific antibodies to the complex, block pathogenic TCRs, and thus prevent diabetes. METHODS We immunized young NOD mice with recombinant I-Ag7-B:RE#3 protein, in which two amino acids of the peptide were mutated to fix the peptide in register 3, and investigated the induced antibodies targeted to the peptide in register 3. RESULTS Specific antibodies targeting I-Ag7-B:RE#3 but not I-Ag7-HEL were identified in the sera of I-Ag7-B:RE#3 immunized mice. The sera inhibited B:9-23-induced T-cell responses in vitro. I-Ag7-B:RE#3 immunization delayed progression to diabetes (versus PBS, p=0.0005), while immunization with I-Ag7-HEL control complex did not. CONCLUSIONS Immunization with I-Ag7-B:RE#3 complex significantly delays the development of insulin autoantibodies and the onset of diabetes in NOD mice, which is associated with the induction of I-Ag7-B:RE#3 antibodies.
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Affiliation(s)
- Li Zhang
- Barbara Davis Center for Childhood Diabetes, University of Colorado Denver, Aurora, CO 80045, USA.
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20
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Brezar V, Carel JC, Boitard C, Mallone R. Beyond the hormone: insulin as an autoimmune target in type 1 diabetes. Endocr Rev 2011; 32:623-69. [PMID: 21700723 DOI: 10.1210/er.2011-0010] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Insulin is not only the hormone produced by pancreatic β-cells but also a key target antigen of the autoimmune islet destruction leading to type 1 diabetes. Despite cultural biases between the fields of endocrinology and immunology, these two facets should not be regarded separately, but rather harmonized in a unifying picture of diabetes pathogenesis. There is increasing evidence suggesting that metabolic factors (β-cell dysfunction, insulin resistance) and immunological components (inflammation and β-cell-directed adaptive immune responses) may synergize toward islet destruction, with insulin standing at the crossroad of these pathways. This concept further calls for a revision of the classical dichotomy between type 1 and type 2 diabetes because metabolic and immune mechanisms may both contribute to different extents to the development of different forms of diabetes. After providing a background on the mechanisms of β-cell autoimmunity, we will explain the role of insulin and its precursors as target antigens expressed not only by β-cells but also in the thymus. Available knowledge on the autoimmune antibody and T-cell responses against insulin will be summarized. A unifying scheme will be proposed to show how different aspects of insulin biology may lead to β-cell destruction and may be therapeutically exploited. We will argue about possible reasons why insulin remains the mainstay of metabolic control in type 1 diabetes but has so far failed to prevent or halt β-cell autoimmunity as an immune modulatory reagent.
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Affiliation(s)
- Vedran Brezar
- Institut National de la Santé et de la Recherche Médicale, Unité 986, DeAR Lab Avenir, Saint Vincent de Paul Hospital, and Paris Descartes University, 82 avenue Denfert Rochereau, 75674 Paris Cedex 14, France
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T cell recognition of autoantigens in human type 1 diabetes: clinical perspectives. Clin Dev Immunol 2011; 2011:513210. [PMID: 21785617 PMCID: PMC3140193 DOI: 10.1155/2011/513210] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Accepted: 03/18/2011] [Indexed: 12/20/2022]
Abstract
Type 1 diabetes (T1D) is an autoimmune disease driven by the activation of lymphocytes against pancreatic β-cells. Among β-cell autoantigens, preproinsulin has been ascribed a key role in the T1D process. The successive steps that control the activation of autoreactive lymphocytes have been extensively studied in animal models of T1D, but remains ill defined in man. In man, T lymphocytes, especially CD8+ T cells, are predominant within insulitis. Developing T-cell assays in diabetes autoimmunity is, thus, a major challenge. It is expected to help defining autoantigens and epitopes that drive the disease process, to pinpoint key functional features of epitope-specific T lymphocytes along the natural history of diabetes and to pave the way towards therapeutic strategies to induce immune tolerance to β-cells. New T-cell technologies will allow defining autoreactive T-cell differentiation programs and characterizing autoimmune responses in comparison with physiologically appropriate immune responses. This may prove instrumental in the discovery of immune correlates of efficacy in clinical trials.
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Gough SCL, Simmonds MJ. The HLA Region and Autoimmune Disease: Associations and Mechanisms of Action. Curr Genomics 2011; 8:453-65. [PMID: 19412418 PMCID: PMC2647156 DOI: 10.2174/138920207783591690] [Citation(s) in RCA: 294] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 10/11/2007] [Accepted: 10/19/2007] [Indexed: 01/01/2023] Open
Abstract
The HLA region encodes several molecules that play key roles in the immune system. Strong association between the HLA region and autoimmune disease (AID) has been established for over fifty years. Association of components of the HLA class II encoded HLA-DRB1-DQA1-DQB1 haplotype has been detected with several AIDs, including rheumatoid arthritis, type 1 diabetes and Graves' disease. Molecules encoded by this region play a key role in exogenous antigen presentation to CD4+ Th cells, indicating the importance of this pathway in AID initiation and progression. Although other components of the HLA class I and III regions have also been investigated for association with AID, apart from the association of HLA-B*27 with ankylosing spondylitis, it has been difficult to determine additional susceptibility loci independent of the strong linkage disequilibrium (LD) with the HLA class II genes. Recent advances in the statistical analysis of LD and the recruitment of large AID datasets have allowed investigation of the HLA class I and III regions to be re-visited. Association of the HLA class I region, independent of known HLA class II effects, has now been detected for several AIDs, including strong association of HLA-B with type 1 diabetes and HLA-C with multiple sclerosis and Graves' disease. These results provide further evidence of a possible role for bacterial or viral infection and CD8+ T cells in AID onset. The advances being made in determining the primary associations within the HLA region and AIDs will not only increase our understanding of the mechanisms behind disease pathogenesis but may also aid in the development of novel therapeutic targets in the future.
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Affiliation(s)
- S C L Gough
- Division of Medical Sciences, University of Birmingham, Institute of Biomedical Research, Birmingham, B15 2TT, UK
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Unger WW, Velthuis J, Abreu JRF, Laban S, Quinten E, Kester MGD, Reker-Hadrup S, Bakker AH, Duinkerken G, Mulder A, Franken KLMC, Hilbrands R, Keymeulen B, Peakman M, Ossendorp F, Drijfhout JW, Schumacher TN, Roep BO. Discovery of low-affinity preproinsulin epitopes and detection of autoreactive CD8 T-cells using combinatorial MHC multimers. J Autoimmun 2011; 37:151-9. [PMID: 21636247 DOI: 10.1016/j.jaut.2011.05.012] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 05/04/2011] [Accepted: 05/09/2011] [Indexed: 11/27/2022]
Abstract
Autoreactive cytotoxic CD8 T-cells (CTLs) play a key pathogenic role in the destruction of insulin-producing beta-cells resulting in type 1 diabetes. However, knowledge regarding their targets is limited, restricting the ability to monitor the course of the disease and immune interventions. In a multi-step discovery process to identify novel CTL epitopes in human preproinsulin (PPI), PPI was digested with purified human proteasomes, and resulting COOH-fragments aligned with algorithm-predicted HLA-binding peptides to yield nine potential HLA-A1, -A2, -A3 or -B7-restricted candidates. An UV-exchange method allowed the generation of a repertoire of multimers including low-affinity HLA-binding peptides. These were labeled with quantum dot-fluorochromes and encoded in a combinatorial fashion, allowing parallel and sensitive detection of specific, low-avidity T-cells. Significantly increased frequencies of T-cells against four novel PPI epitopes (PPI(4-13)/B7, PPI(29-38)/A2, PPI(76-84)/A3 and PPI(79-88)/A3) were detected in stored blood of patients with recent onset diabetes but not in controls. Changes in frequencies of circulating CD8 T-cells against these novel epitopes were detected in blood of islet graft recipients at different time points after transplantation, which correlated with clinical outcome. In conclusion, our novel strategy involving a sensitive multiplex detection technology and requiring minimal volumes of stored blood represents a major improvement in the direct ex-vivo characterization and enumeration of immune cells in the pathogenesis of type 1 diabetes.
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Affiliation(s)
- Wendy W Unger
- Department of Immunohematology & Blood Transfusion, Leiden University Medical Center, 2300 RC Leiden, The Netherlands
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Eerligh P, van Lummel M, Zaldumbide A, Moustakas AK, Duinkerken G, Bondinas G, Koeleman BPC, Papadopoulos GK, Roep BO. Functional consequences of HLA-DQ8 homozygosity versus heterozygosity for islet autoimmunity in type 1 diabetes. Genes Immun 2011; 12:415-27. [PMID: 21562577 DOI: 10.1038/gene.2011.24] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Human leukocyte antigen (HLA) class II haplotypes are established risk factors in type 1 diabetes (T1D). The heterozygous DQ2/8 genotype confers the highest risk, whereas the DQ6/8 genotype is protective. We hypothesized that DQ2/8 trans-molecules composed of α and β chains from DQ2 and DQ8 express unique β-cell epitopes, whereas DQ6 may interfere with peptide binding to DQ8. Here we show that a single insulin epitope (InsB13-21) within the T1D prototype antigenic InsB6-22 peptide can bind to both cis- and trans-dimers, although these molecules display different peptide binding patterns. DQ6 binds a distinct insulin epitope (InsB6-14). The phenotype of DQ8-restricted T cells from a T1D patient changed from proinflammatory to anti-inflammatory in the presence of DQ6. Our data provide new insights into both susceptible and protective mechanism of DQ, where protecting HLA molecules bind autoantigens in a different (competing) binding register leading to 'epitope stealing', thereby inducing a regulatory, rather than a pathogenic immune response.
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Affiliation(s)
- P Eerligh
- Department of Immunohaematology and Blood Transfusion, Leiden University Medical Center, Leiden, The Netherlands
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Scott GS, Fishman S, Khai Siew L, Margalit A, Chapman S, Chervonsky AV, Wen L, Gross G, Susan Wong F. Immunotargeting of insulin reactive CD8 T cells to prevent Diabetes. J Autoimmun 2010; 35:390-7. [DOI: 10.1016/j.jaut.2010.08.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Revised: 08/16/2010] [Accepted: 08/22/2010] [Indexed: 02/06/2023]
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Schütz C, Oelke M, Schneck JP, Mackensen A, Fleck M. Killer artificial antigen-presenting cells: the synthetic embodiment of a 'guided missile'. Immunotherapy 2010; 2:539-50. [PMID: 20636007 DOI: 10.2217/imt.10.26] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
At present, the treatment of T-cell-dependent autoimmune diseases relies exclusively on strategies leading to nonspecific suppression of the immune systems causing a substantial reduced ability to control concomitant infections or malignancies. Furthermore, long-term treatment with most drugs is accompanied by several serious adverse effects and does not consequently result in cure of the primary immunological malfunction. By contrast, antigen-specific immunotherapy offers the potential to achieve the highest therapeutic efficiency in accordance with minimal adverse effects. Therefore, several studies have been performed utilizing antigen-presenting cells specifically engineered to deplete allo- or antigen-specific T cells ('guided missiles'). Many of these strategies take advantage of the Fas/Fas ligand signaling pathway to efficiently induce antigen-presenting cell-mediated apoptosis in targeted T cells. In this article, we discuss the advantages and shortcomings of a novel non-cell-based 'killer artificial antigen-presenting cell' strategy, developed to overcome obstacles related to current cell-based approaches for the treatment of T-cell-mediated autoimmunity.
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Affiliation(s)
- Christian Schütz
- Department of Internal Medicine I, University Medical Center Regensburg, Franz-Josef-Strauss-Allee 11, 93042 Regensburg, Germany.
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Moser A, Hsu HT, van Endert P. Beta cell antigens in type 1 diabetes: triggers in pathogenesis and therapeutic targets. F1000 BIOLOGY REPORTS 2010; 2:75. [PMID: 21173836 PMCID: PMC2981181 DOI: 10.3410/b2-75] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Recognition of pancreatic beta cell antigens by autoreactive T lymphocytes plays a central role in the pathogenesis of insulin-dependent type 1 diabetes. Recent results suggest that non-conventional antigenic epitope processing and presentation may contribute to triggering and maintaining autoreactive responses. Moreover, promising results raise hope that autoantigens may become safe and specific therapeutics for type 1 diabetes in the future.
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Affiliation(s)
- Anna Moser
- Faculté de Médecine René Descartes, Université Paris Descartes161 rue de Sèvres, 75015 ParisFrance
- Institut National de la Santé et de la Recherche MédicaleUnité 1013, 161 rue de Sèvres, 75015 ParisFrance
| | - Hsiang-Ting Hsu
- Faculté de Médecine René Descartes, Université Paris Descartes161 rue de Sèvres, 75015 ParisFrance
- Institut National de la Santé et de la Recherche MédicaleUnité 1013, 161 rue de Sèvres, 75015 ParisFrance
| | - Peter van Endert
- Faculté de Médecine René Descartes, Université Paris Descartes161 rue de Sèvres, 75015 ParisFrance
- Institut National de la Santé et de la Recherche MédicaleUnité 1013, 161 rue de Sèvres, 75015 ParisFrance
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[Antitumor effects of raddeanin A on S180, H22 and U14 cell xenografts in mice]. Curr Opin Immunol 2010; 20:111-8. [PMID: 18799026 DOI: 10.1016/j.coi.2007.11.005] [Citation(s) in RCA: 144] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2007] [Revised: 11/19/2007] [Accepted: 11/19/2007] [Indexed: 01/19/2023]
Abstract
BACKGROUND & OBJECTIVE Raddeanin A, a triterpenoid saponin from Anemone raddeana Regel, has good antitumor activity in vitro. This study was to investigate its antitumor effects on tumor cell xenografts in mice. METHODS The inhibitory effects of raddeanin A on the proliferation of human nasopharyngeal carcinoma KB cells and ovarian cancer SKOV3 cells were measured by MTT assay. The inhibitory effects of raddeanin A injection on the growth of sarcoma S180, liver cancer H22 and cervical carcinoma U14 cell xenografts in mice and the effect of raddeanin A lavage on the growth of S180 cell xenografts were measured. The acute toxicity of raddeanin A was also measured. RESULTS The 50% inhibition concentration (IC(50)) of raddeanin A was 4.64 microg/mL for KB cells and 1.40 microg/mL for SKOV3 cells. When injected with raddeanin A at a dose of 4.5 mg/kg, the growth inhibition rates of S180, H22 and U14 cell xenografts were 60.5%, 36.2% and 61.8%, respectively. When lavaged with raddeanin A at a dose of 200 mg/kg, the growth inhibition rate of S180 cell xenografts was 64.7%. The median lethal dose (LD50) of raddeanin A lavage was 1.1 g/kg and that of raddeanin A injection was 16.1 mg/kg. CONCLUSION Raddeanin A has good antitumor activity both in vitro and in vivo, and would be a potential antitumor medicine.
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Abstract
PURPOSE OF REVIEW Description of the immunologic components needed for autoimmune diabetes. RECENT FINDINGS The major histocompatability complex (MHC) class II molecules are the primary susceptibility genes for many autoimmune diseases, including type 1 diabetes. Understanding of the structural interaction between MHC molecules, antigenic peptides, and T-cell receptors (the three components of the trimolecular complex) has increased greatly over the past several years. The components of the anti-insulin trimolecular complex and findings that insulin is a key autoantigen in type 1 diabetes are reviewed. SUMMARY The anti-insulin trimolecular complex is well defined in the nonobese diabetic mouse model. Insulin and specifically, the amino acid sequence 9 to 23 of the insulin B chain, represents a primary antigenic target for islet autoimmunity in the nonobese diabetic mouse model of type 1 diabetes with a specific mutation of this peptide preventing all diabetes. Initial studies suggest the human homologs of the anti-insulin trimolecular complex may be relevant in human disease.
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Affiliation(s)
- Aaron W Michels
- Barbara Davis Center for Childhood Diabetes, University of Colorado Denver, Aurora, Colorado 80045, USA.
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30
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Velthuis JH, Unger WW, Abreu JR, Duinkerken G, Franken K, Peakman M, Bakker AH, Reker-Hadrup S, Keymeulen B, Drijfhout JW, Schumacher TN, Roep BO. Simultaneous detection of circulating autoreactive CD8+ T-cells specific for different islet cell-associated epitopes using combinatorial MHC multimers. Diabetes 2010; 59:1721-30. [PMID: 20357361 PMCID: PMC2889772 DOI: 10.2337/db09-1486] [Citation(s) in RCA: 159] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Accepted: 03/15/2010] [Indexed: 01/31/2023]
Abstract
OBJECTIVE Type 1 diabetes results from selective T-cell-mediated destruction of the insulin-producing beta-cells in the pancreas. In this process, islet epitope-specific CD8(+) T-cells play a pivotal role. Thus, monitoring of multiple islet-specific CD8(+) T-cells may prove to be valuable for measuring disease activity, progression, and intervention. Yet, conventional detection techniques (ELISPOT and HLA tetramers) require many cells and are relatively insensitive. RESEARCH DESIGN AND METHODS Here, we used a combinatorial quantum dot major histocompatibility complex multimer technique to simultaneously monitor the presence of HLA-A2 restricted insulin B(10-18), prepro-insulin (PPI)(15-24), islet antigen (IA)-2(797-805), GAD65(114-123), islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP)(265-273), and prepro islet amyloid polypeptide (ppIAPP)(5-13)-specific CD8(+) T-cells in recent-onset diabetic patients, their siblings, healthy control subjects, and islet cell transplantation recipients. RESULTS Using this kit, islet autoreactive CD8(+) T-cells recognizing insulin B(10-18), IA-2(797-805), and IGRP(265-273) were shown to be frequently detectable in recent-onset diabetic patients but rarely in healthy control subjects; PPI(15-24) proved to be the most sensitive epitope. Applying the "Diab-Q-kit" to samples of islet cell transplantation recipients allowed detection of changes of autoreactive T-cell frequencies against multiple islet cell-derived epitopes that were associated with disease activity and correlated with clinical outcome. CONCLUSIONS A kit was developed that allows simultaneous detection of CD8(+) T-cells reactive to multiple HLA-A2-restricted beta-cell epitopes requiring limited amounts of blood, without a need for in vitro culture, that is applicable on stored blood samples.
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Affiliation(s)
- Jurjen H. Velthuis
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, the Netherlands
- JDRF Center for Beta Cell Therapy in Diabetes Brussels, Belgium
| | - Wendy W. Unger
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, the Netherlands
| | - Joana R.F. Abreu
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, the Netherlands
| | - Gaby Duinkerken
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, the Netherlands
- JDRF Center for Beta Cell Therapy in Diabetes Brussels, Belgium
| | - Kees Franken
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, the Netherlands
| | - Mark Peakman
- Department of Immunobiology, King's College School of Medicine, Guy's Hospital, London, U.K
| | - Arnold H. Bakker
- Divison of Immunology, The Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Sine Reker-Hadrup
- Divison of Immunology, The Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Bart Keymeulen
- JDRF Center for Beta Cell Therapy in Diabetes Brussels, Belgium
- Diabetes Research Center, Brussels Free University-VUB, Brussels, Belgium
| | | | - Ton N. Schumacher
- Divison of Immunology, The Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Bart O. Roep
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, the Netherlands
- JDRF Center for Beta Cell Therapy in Diabetes Brussels, Belgium
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Pugliese A. Insulin: a critical autoantigen and potential therapeutic agent in Type 1 diabetes. Expert Rev Clin Immunol 2010; 2:419-31. [PMID: 20476913 DOI: 10.1586/1744666x.2.3.419] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Insulin is a polypeptide hormone secreted by pancreatic beta-cells and is critical for glucose homeostasis. Abnormalities in insulin secretion result in various forms of diabetes. Type 1A diabetes is an autoimmune form in which insulin has been identified as a critical autoantigen. Recent studies have identified genetic determinants of insulin-specific autoimmune responses and insulin epitopes targeted by autoreactive T lymphocytes. The study of insulin as an autoantigen has also led to discoveries about basic mechanisms of immunological tolerance and autoimmunity. Experimental and clinical evidence suggests that insulin and insulin-derived peptides may delay and perhaps prevent the development of diabetes. Further clinical trials may identify effective treatment modalities for inhibiting diabetogenic autoimmunity and preventing disease development.
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Affiliation(s)
- Alberto Pugliese
- Diabetes Research Institute, University of Miami Miller School of Medicine, 1450 NW 10th Avenue, Miami, FL 33136, USA.
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32
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Stadinski B, Kappler J, Eisenbarth GS. Molecular targeting of islet autoantigens. Immunity 2010; 32:446-56. [PMID: 20412755 DOI: 10.1016/j.immuni.2010.04.008] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2010] [Revised: 04/02/2010] [Accepted: 04/05/2010] [Indexed: 12/11/2022]
Abstract
Type 1 diabetes of man and animal models results from immune-mediated specific beta cell destruction. Multiple islet antigens are targets of autoimmunity and most of these are not beta cell specific. Immune responses to insulin appear to be essential for the development of diabetes of the NOD mouse. In this review, we will emphasize the unusual manner in which selected autoantigenic peptides (particularly the recently discovered target of BDC2.5 T cells [chromagranin A]) are presented and recognized by autoreactive CD4(+) T cell receptors. We hypothesize that "unusual" structural interactions of specific trimolecular complexes (MHC class II, peptide, and T cell receptors) are fundamental to the escape from the thymus of autoreactive T cells able to cause type 1 diabetes.
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Cernea S, Herold KC. Monitoring of antigen-specific CD8 T cells in patients with type 1 diabetes treated with antiCD3 monoclonal antibodies. Clin Immunol 2010; 134:121-9. [PMID: 19837003 DOI: 10.1016/j.clim.2009.09.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2009] [Revised: 08/22/2009] [Accepted: 09/12/2009] [Indexed: 01/11/2023]
Abstract
The way in which anti-CD3 monoclonal antibodies (mAbs) modify human immune responses in type 1 diabetes (T1DM) is not known. We prepared a panel of Class I HLA-A2.1 tetramers with peptides from diabetes-associated antigens and studied the frequency and phenotype of the cells in patients with T1DM and blood donors and in patients treated with anti-CD3 mAb (Teplizumab). More patients with T1DM showed positive staining for at least 1 tetramer using frozen and fresh samples (p<0.05). Three months following treatment with anti-CD3 mAb, the proportion of GAD65- and InsB-peptide reactive CD8+ T cells increased (p<0.05). The phenotype of these cells was modulated from naïve to effector memoryRA+. We concludethat Class I MHC tetramers can identify antigen specific CD8+ T cells in patients with T1DM. The frequency of certain specificities increases after treatment with anti-CD3 mAb. Their modulated phenotype may have functional consequences for their pathogenicity.
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Affiliation(s)
- Simona Cernea
- Department of Immunobiology, Yale University, 10 Amistad Street, 131D, New Haven, CT 06520, USA
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Abstract
Apoptosis of beta cells is a feature of both type 1 and type 2 diabetes as well as loss of islets after transplantation. In type 1 diabetes, beta cells are destroyed by immunological mechanisms. In type 2 diabetes abnormal levels of metabolic factors contribute to beta cell failure and subsequent apoptosis. Loss of beta cells after islet transplantation is due to many factors including the stress associated with islet isolation, primary graft non-function and allogeneic graft rejection. Irrespective of the exact mediators, highly conserved intracellular pathways of apoptosis are triggered. This review will outline the molecular mediators of beta cell apoptosis and the intracellular pathways activated.
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Affiliation(s)
- Helen E Thomas
- St. Vincent's Institute of Medical Research, 41 Victoria Parade, Fitzroy, VIC 3065, Australia.
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35
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La Torre D, Lernmark A. Immunology of beta-cell destruction. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 654:537-83. [PMID: 20217514 DOI: 10.1007/978-90-481-3271-3_24] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The pancreatic islet beta-cells are the target for an autoimmune process that eventually results in an inability to control blood glucose due to the lack of insulin. The different steps that eventually lead to the complete loss of the beta-cells are reviewed to include the very first step of a triggering event that initiates the development of beta-cell autoimmunity to the last step of appearance of islet-cell autoantibodies, which may mark that insulitis is about to form. The observations that the initial beta-cell destruction by virus or other environmental factors triggers islet autoimmunity not in the islets but in the draining pancreatic lymph nodes are reviewed along with possible basic mechanisms of loss of tolerance to islet autoantigens. Once islet autoimmunity is established the question is how beta-cells are progressively killed by autoreactive lymphocytes which eventually results in chronic insulitis. Many of these series of events have been dissected in spontaneously diabetic mice or rats, but controlled clinical trials have shown that rodent observations are not always translated into mechanisms in humans. Attempts are therefore needed to clarify the step 1 triggering mechanisms and the step to chronic autoimmune insulitis to develop evidence-based treatment approaches to prevent type 1 diabetes.
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Affiliation(s)
- Daria La Torre
- Lund University, CRC, Department of Clinical Sciences, University Hospital MAS, SE-205 02, Malmö, Sweden.
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Jarchum I, DiLorenzo TP. Ins2 deficiency augments spontaneous HLA-A*0201-restricted T cell responses to insulin. THE JOURNAL OF IMMUNOLOGY 2009; 184:658-65. [PMID: 19966211 DOI: 10.4049/jimmunol.0903414] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Type 1 diabetes results from the autoimmune destruction of insulin-producing beta cells by T cells specific for beta cell Ags, including insulin. In humans, the non-MHC locus conferring the strongest disease susceptibility is the insulin gene, and alleles yielding lower thymic insulin expression are predisposing. We sought to incorporate this characteristic into an HLA-transgenic model of the disease and to determine the influence of reduced thymic insulin expression on CD8+ T cell responses to preproinsulin. We examined NOD.Ins2(-/-) mice, which do not express insulin in the thymus and show accelerated disease, to determine whether they exhibit quantitative or qualitative differences in CD8+ T cell responses to preproinsulin. We also generated NOD.Ins2(-/-) mice expressing type 1 diabetes-associated HLA-A*0201 (designated NOD.beta2m(-/-).HHD.Ins2(-/-)) in an effort to obtain an improved humanized disease model. We found that CD8+ T cell reactivity to certain insulin peptides was more readily detected in NOD.Ins2(-/-) mice than in NOD mice. Furthermore, the proportion of insulin-reactive CD8+ T cells infiltrating the islets of NOD.Ins2(-/-) mice was increased. NOD.beta2m(-/-).HHD.Ins2(-/-) mice exhibited rapid onset of disease and had an increased proportion of HLA-A*0201-restricted insulin-reactive T cells, including those targeting the clinically relevant epitope Ins B10-18. Our results suggest that insulin alleles that predispose to type 1 diabetes in humans do so, at least in part, by facilitating CD8+ T cell responses to the protein. We propose the NOD.beta2m(-/-).HHD.Ins2(-/-) strain as an improved humanized disease model, in particular for studies seeking to develop therapeutic strategies targeting insulin-specific T cells.
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Affiliation(s)
- Irene Jarchum
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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Martinuzzi E, Lemonnier FA, Boitard C, Mallone R. Measurement of CD8 T cell responses in human type 1 diabetes. Ann N Y Acad Sci 2009; 1150:61-7. [PMID: 19120269 DOI: 10.1196/annals.1447.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Type 1 diabetes (T1D) is a T cell-mediated autoimmune disease targeting pancreatic beta-cells. Despite this textbook definition, it is quite striking that neither the diagnosis nor the therapy nor the follow-up of T1D "belong" to immunologists, but rather to endocrinologists whose only option is to limit the consequences of the disease. Immune therapies would seem better suited to correct the causes of T1D, but critical laboratory tools are missing for early diagnosis, prognostic stratification, and therapeutic follow-up. The immune markers routinely available are limited to autoantibodies, which have some intrinsic limitations. Because T cells are central pathogenic actors of T1D, the quest for their measurement appeared to offer a path towards new autoimmune markers. Given the strong association between T1D susceptibility and the HLA class II locus, investigators have long been focused on CD4(+) T cells. However, data gathered in the NOD mouse and the examination of human insulitis point to a critical role of CD8(+) T cells in the pathogenesis of T1D. These observations have revived interest in trying to measure CD8(+) T cell responses in human T1D. Achievement of this goal mainly depends on two factors. First, the relevant epitopes need to be identified. Second, appropriate readouts and measurement techniques need to be selected. This review summarizes recent advances on both of these battlefronts, and discusses the potential clinical applications of T cell assays.
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Toma A, Laïka T, Haddouk S, Luce S, Briand JP, Camoin L, Connan F, Lambert M, Caillat-Zucman S, Carel JC, Muller S, Choppin J, Lemonnier F, Boitard C. Recognition of human proinsulin leader sequence by class I-restricted T-cells in HLA-A*0201 transgenic mice and in human type 1 diabetes. Diabetes 2009; 58:394-402. [PMID: 19011169 PMCID: PMC2628613 DOI: 10.2337/db08-0599] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE A restricted region of proinsulin located in the B chain and adjacent region of C-peptide has been shown to contain numerous candidate epitopes recognized by CD8(+) T-cells. Our objective is to characterize HLA class I-restricted epitopes located within the preproinsulin leader sequence. RESEARCH DESIGN AND METHODS Seven 8- to 11-mer preproinsulin peptides carrying anchoring residues for HLA-A1, -A2, -A24, and -B8 were selected from databases. HLA-A2-restricted peptides were tested for immunogenicity in transgenic mice expressing a chimeric HLA-A*0201/beta2-microglobulin molecule. The peptides were studied for binding to purified HLA class I molecules, selected for carrying COOH-terminal residues generated by proteasome digestion in vitro and tested for recognition by human lymphocytes using an ex vivo interferon-gamma (IFN-gamma) ELISpot assay. RESULTS Five HLA-A2-restricted peptides were immunogenic in transgenic mice. Murine T-cell clones specific for these peptides were cytotoxic against cells transfected with the preproinsulin gene. They were recognized by peripheral blood mononuclear cells (PBMCs) from 17 of 21 HLA-A2 type 1 diabetic patients. PBMCs from 25 of 38 HLA-A1, -A2, -A24, or -B8 patients produced IFN-gamma in response to six preproinsulin peptides covering residues 2-25 within the preproinsulin region. In most patients, the response was against several class I-restricted peptides. T-cells recognizing preproinsulin peptide were characterized as CD8(+) T-cells by staining with peptide/HLA-A2 tetramers. CONCLUSIONS We defined class I-restricted epitopes located within the leader sequence of human preproinsulin through in vivo (transgenic mice) and ex vivo (diabetic patients) assays, illustrating the possible role of preproinsulin-specific CD8(+) T-cells in human type 1 diabetes.
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Affiliation(s)
- Andréa Toma
- Institut National de Santé et de Recherche Médicale U561 et Université Paris N, Hôpital Cochin-Saint Vincent de Paul, Paris, France
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Current research status of immunology in the genomic era. ACTA ACUST UNITED AC 2009; 52:43-9. [PMID: 19152083 PMCID: PMC7089291 DOI: 10.1007/s11427-009-0006-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2008] [Accepted: 10/08/2008] [Indexed: 01/16/2023]
Abstract
This review updates the current status of immunology research under the influence of genomics, both conceptually and technologically. It particularly highlights the advantages of employing the high-throughput and large-scale technology, the large genomic database, and bioinformatic power in the immunology research. The fast development in the fields of basic immunology, clinical immunology (tumor and infectious immunology) and vaccine designing is illustrated with respect to the successful usage of genomic strategy. We also speculate the future research directions of immunology in the era of genomics and post-genomics.
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Skowera A, Ellis RJ, Varela-Calviño R, Arif S, Huang GC, Van-Krinks C, Zaremba A, Rackham C, Allen JS, Tree TIM, Zhao M, Dayan CM, Sewell AK, Unger WW, Unger W, Drijfhout JW, Ossendorp F, Roep BO, Peakman M. CTLs are targeted to kill beta cells in patients with type 1 diabetes through recognition of a glucose-regulated preproinsulin epitope. J Clin Invest 2008; 118:3390-402. [PMID: 18802479 DOI: 10.1172/jci35449] [Citation(s) in RCA: 202] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2008] [Accepted: 07/21/2008] [Indexed: 12/15/2022] Open
Abstract
The final pathway of beta cell destruction leading to insulin deficiency, hyperglycemia, and clinical type 1 diabetes is unknown. Here we show that circulating CTLs can kill beta cells via recognition of a glucose-regulated epitope. First, we identified 2 naturally processed epitopes from the human preproinsulin signal peptide by elution from HLA-A2 (specifically, the protein encoded by the A*0201 allele) molecules. Processing of these was unconventional, requiring neither the proteasome nor transporter associated with processing (TAP). However, both epitopes were major targets for circulating effector CD8+ T cells from HLA-A2+ patients with type 1 diabetes. Moreover, cloned preproinsulin signal peptide-specific CD8+ T cells killed human beta cells in vitro. Critically, at high glucose concentration, beta cell presentation of preproinsulin signal epitope increased, as did CTL killing. This study provides direct evidence that autoreactive CTLs are present in the circulation of patients with type 1 diabetes and that they can kill human beta cells. These results also identify a mechanism of self-antigen presentation that is under pathophysiological regulation and could expose insulin-producing beta cells to increasing cytotoxicity at the later stages of the development of clinical diabetes. Our findings suggest that autoreactive CTLs are important targets for immune-based interventions in type 1 diabetes and argue for early, aggressive insulin therapy to preserve remaining beta cells.
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Affiliation(s)
- Ania Skowera
- Department of Immunobiology, King's College London, London, United Kingdom
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CD8+ T-cells and their interaction with other cells in damage to islet beta-cells. Biochem Soc Trans 2008; 36:316-20. [PMID: 18481949 DOI: 10.1042/bst0360316] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The autoimmune attack on pancreatic beta-cells is orchestrated by a variety of cells that produce cytokines and other toxic mediators. CD8(+) T-cells work together with other lymphocytes and antigen-presenting cells to mediate this damage and have been shown in animal models to be important both in the early stages of diabetes development and in the final effector stages. Recently, there has also been much interest in studying CD8(+) T-cells that may play a role in human Type 1 diabetes and identifying their antigenic targets. The present paper will focus on the activation of CD8(+) T-cells and their interaction with other cells of the immune system and discuss the target antigens and mechanisms of damage that the CD8(+) T-cells use in the attack on the islet beta-cell.
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Serreze DV, Choisy-Rossi CM, Grier AE, Holl TM, Chapman HD, Gahagan JR, Osborne MA, Zhang W, King BL, Brown A, Roopenian D, Marron MP. Through regulation of TCR expression levels, an Idd7 region gene(s) interactively contributes to the impaired thymic deletion of autoreactive diabetogenic CD8+ T cells in nonobese diabetic mice. THE JOURNAL OF IMMUNOLOGY 2008; 180:3250-9. [PMID: 18292549 DOI: 10.4049/jimmunol.180.5.3250] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
When expressed in NOD, but not C57BL/6 (B6) genetic background mice, the common class I variants encoded by the H2g7 MHC haplotype aberrantly lose the ability to mediate the thymic deletion of autoreactive CD8+ T cells contributing to type 1 diabetes (T1D). This indicated some subset of the T1D susceptibility (Idd) genes located outside the MHC of NOD mice interactively impair the negative selection of diabetogenic CD8+ T cells. In this study, using both linkage and congenic strain analyses, we demonstrate contributions from a polymorphic gene(s) in the previously described Idd7 locus on the proximal portion of Chromosome 7 predominantly, but not exclusively, determines the extent to which H2g7 class I molecules can mediate the thymic deletion of diabetogenic CD8+ T cells as illustrated using the AI4 TCR transgenic system. The polymorphic Idd7 region gene(s) appears to control events that respectively result in high vs low expression of the AI4 clonotypic TCR alpha-chain on developing thymocytes in B6.H2g7 and NOD background mice. This expression difference likely lowers levels of the clonotypic AI4 TCR in NOD, but not B6.H2g7 thymocytes, below the threshold presumably necessary to induce a signaling response sufficient to trigger negative selection upon Ag engagement. These findings provide further insight to how susceptibility genes, both within and outside the MHC, may interact to elicit autoreactive T cell responses mediating T1D development in both NOD mice and human patients.
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Campbell PD, Estella E, Dudek NL, Jhala G, Thomas HE, Kay TWH, Mannering SI. Cytotoxic T-lymphocyte-mediated killing of human pancreatic islet cells in vitro. Hum Immunol 2008; 69:543-51. [PMID: 18639598 DOI: 10.1016/j.humimm.2008.06.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2008] [Revised: 06/10/2008] [Accepted: 06/16/2008] [Indexed: 11/30/2022]
Abstract
Cytotoxic T lymphocytes (CTL) are believed to play an essential role in beta-cell destruction leading to development of type 1 diabetes and allogeneic islet graft failure. We aimed to identify the mechanisms used by CTL to kill human beta cells. CTL clones that recognize epitopes from influenza virus and Epstein-Barr virus restricted by human leukocyte antigen (HLA)-A0201 and -B0801, respectively, were used to investigate the susceptibility of human beta cells to CTL. In a short-term (5-hour) assay, CTL killed human islet cells of the appropriate major histocompatibility complex (MHC) class I type that had been pulsed with viral peptides. Killing was increased by pretreating islets with interferon gamma that increases MHC class I on target cells. Killing was abolished by incubation of CTL with the perforin inhibitor concanamycin A. The Fas pathway did not contribute to killing because blocking with neutralizing anti-Fas ligand antibody did not significantly reduce beta-cell killing. In conclusion, we report a novel way of investigating the interaction between CTL and human islets. Human islets were rapidly killed in vitro by MHC class I-restricted CTL predominantly by the granule exocytosis pathway.
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Affiliation(s)
- Peter D Campbell
- St Vincent's Institute, The University of Melbourne Department of Medicine, St. Vincent's Hospital, Fitzroy, Australia
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Martinuzzi E, Novelli G, Scotto M, Blancou P, Bach JM, Chaillous L, Bruno G, Chatenoud L, van Endert P, Mallone R. The frequency and immunodominance of islet-specific CD8+ T-cell responses change after type 1 diabetes diagnosis and treatment. Diabetes 2008; 57:1312-20. [PMID: 18305140 DOI: 10.2337/db07-1594] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE Islet-reactive CD8(+) T-cells play a key role in the pathogenesis of type 1 diabetes in the NOD mouse. The predominant T-cell specificities change over time, but whether similar shifts also occur after clinical diagnosis and insulin treatment in type 1 diabetic patients is unknown. RESEARCH DESIGN AND METHODS We took advantage of a recently validated islet-specific CD8(+) T-cell gamma-interferon enzyme-linked immunospot (ISL8Spot) assay to follow responses against preproinsulin (PPI), GAD, insulinoma-associated protein 2 (IA-2), and islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP) epitopes in 15 HLA-A2(+) adult type 1 diabetic patients close to diagnosis and at a second time point 7-16 months later. RESULTS CD8(+) T-cell reactivities were less frequent at follow-up, as 28.6% of responses tested positive at type 1 diabetes diagnosis vs. 13.2% after a median of 11 months (P = 0.003). While GAD and IA-2 autoantibody (aAb) titers were unchanged in 75% of cases, the fraction of patients responding to PPI and/or GAD epitopes by ISL8Spot decreased from 60-67 to 20% (P < 0.02). The previously subdominant IA-2(206-214) and IGRP(265-273) peptides were newly targeted, thus becoming the immunodominant epitopes. CONCLUSIONS Shifts both in frequency and in immunodominance of CD8(+) T-cell responses occur more rapidly than do changes in aAb titers. These different kinetics may suggest complementary clinical applications for T-cell and aAb measurements.
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Affiliation(s)
- Bart O Roep
- Department of Immunohaematology & Blood Transfusion, Leiden University Medical Center, Leiden, the Netherlands.
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Énée E, Martinuzzi E, Blancou P, Bach JM, Mallone R, van Endert P. Equivalent Specificity of Peripheral Blood and Islet-Infiltrating CD8+ T Lymphocytes in Spontaneously Diabetic HLA-A2 Transgenic NOD Mice. THE JOURNAL OF IMMUNOLOGY 2008; 180:5430-8. [DOI: 10.4049/jimmunol.180.8.5430] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Abstract
T lymphocytes' crucial role in the autoimmune process leading to insulin-dependent type 1 diabetes is now universally recognized. Research focuses on identifying pathogenic and nonpathogenic T cells, understanding how they are primed and expanded, characterizing their antigen specificity, and ultimately on devising strategies to blunt their autoaggressive action. In this review, we focus on recent progress identified in three different areas. Results obtained with transgenic mice acknowledge proinsulin's unique role in triggering autoimmunity and suggest that other beta-cell proteins are recognized as a result of epitope spreading, at least in the nonobese diabetic mouse. Progress has also been achieved by developing and validating reliable CD4+ and CD8+ T-cell tests that may prove valuable for diagnostic and prognostic purposes in the near future. Finally, recent results provide novel and important guidance for manipulating autoreactive T-cell responses against beta-cell antigens.
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Petrich de Marquesini LG, Moustakas AK, Thomas IJ, Wen L, Papadopoulos GK, Wong FS. Functional inhibition related to structure of a highly potent insulin-specific CD8 T cell clone using altered peptide ligands. Eur J Immunol 2008; 38:240-9. [PMID: 18157812 PMCID: PMC2901522 DOI: 10.1002/eji.200737762] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Insulin-reactive CD8 T cells are amongst the earliest islet-infiltrating CD8 T cells in NOD mice. Cloned insulin B15–23-reactive cells (designated G9C8), restricted by H-2Kd, are highly diabetogenic. We used altered peptide ligands (APL) substituted at TCR contact sites, positions (p)6 and 8, to investigate G9C8 T cell function and correlated this with structure. Cytotoxicity and IFN-γ production assays revealed that p6G and p8R could not be replaced by any naturally occurring amino acid without abrogating recognition and functional response by the G9C8 clone. When tested for antagonist activity with APL differing from the native peptide at either of these positions, the peptide variants, G6H and R8L showed the capacity to reduce the agonist response to the native peptide. The antagonist activity in cytotoxicity and IFN-γ production assays can be correlated with conformational changes induced by different structures of the MHC-peptide complexes, shown by molecular modeling. We conclude that p6 and p8 of the insulin B15–23 peptide are very important for TCR stimulation of this clone and no substitutions are tolerated at these positions in the peptide. This is important in considering the therapeutic use of peptides as APL that encompass both CD4 and CD8 epitopes of insulin.
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Human CD8 responses to a complete epitope set from preproinsulin: implications for approaches to epitope discovery. J Clin Immunol 2008; 28:350-60. [PMID: 18311511 DOI: 10.1007/s10875-008-9177-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2007] [Accepted: 01/15/2008] [Indexed: 12/14/2022]
Abstract
PURPOSE In this study, we explored the breadth of CD8 T cell reactivity to preproinsulin (PPI) in type 1 diabetes. MATERIALS AND METHODS We tested a complete peptide set in pools covering all 406 potential 8-11mer epitopes of PPI and 61 algorithm-predicted human leukocyte antigen (HLA)-A2-specific epitopes (15 pools) from islet-specific glucose-6-phophatase catalytic subunit-related protein (IGRP), using a CD8-specific granzyme B enzyme-linked immunosorbent spot assay. RESULTS Responses were seen to 64 of the 102 PPI pools in two or more newly diagnosed patients (63%) compared to 11 pools in the control subjects (11%, p < 0.0001, Fisher's exact test). We identified five pools containing 20 peptides, which distinguished patients from control subjects, most of which had predicted low-affinity binding to HLA class I molecules. In contrast, fewer (5 of 15 = 33%) IGRP peptide pools, selected by higher binding affinity for HLA-A2 (present in seven of eight patients and five of seven control subjects), stimulated responses in two or more patients, and none stimulated responses in more than two control subjects (p = 0.042, Fisher's exact test). CONCLUSION Thus, we conclude that CD8 T cell reactivity to PPI in patients with type 1 diabetes can be much broader than shown previously and more diverse than seen in control subjects. Furthermore, responses were often stimulated by peptides with low predicted HLA-binding affinities.
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