1
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Mori S, Kohyama M, Yasumizu Y, Tada A, Tanzawa K, Shishido T, Kishida K, Jin H, Nishide M, Kawada S, Motooka D, Okuzaki D, Naito R, Nakai W, Kanda T, Murata T, Terao C, Ohmura K, Arase N, Kurosaki T, Fujimoto M, Suenaga T, Kumanogoh A, Sakaguchi S, Ogawa Y, Arase H. Neoself-antigens are the primary target for autoreactive T cells in human lupus. Cell 2024:S0092-8674(24)00913-9. [PMID: 39276775 DOI: 10.1016/j.cell.2024.08.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 05/06/2024] [Accepted: 08/12/2024] [Indexed: 09/17/2024]
Abstract
Major histocompatibility complex class II (MHC-II) is the most significant genetic risk factor for systemic lupus erythematosus (SLE), but the nature of the self-antigens that trigger autoimmunity remains unclear. Unusual self-antigens, termed neoself-antigens, are presented on MHC-II in the absence of the invariant chain essential for peptide presentation. Here, we demonstrate that neoself-antigens are the primary target for autoreactive T cells clonally expanded in SLE. When neoself-antigen presentation was induced by deleting the invariant chain in adult mice, neoself-reactive T cells were clonally expanded, leading to the development of lupus-like disease. Furthermore, we found that neoself-reactive CD4+ T cells were significantly expanded in SLE patients. A high frequency of Epstein-Barr virus reactivation is a risk factor for SLE. Neoself-reactive lupus T cells were activated by Epstein-Barr-virus-reactivated cells through downregulation of the invariant chain. Together, our findings imply that neoself-antigen presentation by MHC-II plays a crucial role in the pathogenesis of SLE.
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Affiliation(s)
- Shunsuke Mori
- Laboratory of Immunochemistry, World Premier International Immunology Frontier Research Centre, Osaka University, Osaka 565-0871, Japan
| | - Masako Kohyama
- Laboratory of Immunochemistry, World Premier International Immunology Frontier Research Centre, Osaka University, Osaka 565-0871, Japan; Department of Immunochemistry, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
| | - Yoshiaki Yasumizu
- Department of Experimental Immunology, World Premier International Immunology Frontier Research Centre, Osaka University, Osaka 565-0871, Japan; Integrated Frontier Research for Medical Science Division, Institute for Open and Transdisciplinary Research Initiatives, Osaka University, Osaka 565-0871, Japan
| | - Asa Tada
- Laboratory of Immunochemistry, World Premier International Immunology Frontier Research Centre, Osaka University, Osaka 565-0871, Japan
| | - Kaito Tanzawa
- Laboratory of Immunochemistry, World Premier International Immunology Frontier Research Centre, Osaka University, Osaka 565-0871, Japan; Department of Immunochemistry, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
| | - Tatsuya Shishido
- Laboratory of Immunochemistry, World Premier International Immunology Frontier Research Centre, Osaka University, Osaka 565-0871, Japan; Department of Immunochemistry, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
| | - Kazuki Kishida
- Department of Immunochemistry, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
| | - Hui Jin
- Department of Immunochemistry, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
| | - Masayuki Nishide
- Department of Respiratory Medicine and Clinical Immunology, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan
| | - Shoji Kawada
- Department of Respiratory Medicine and Clinical Immunology, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan
| | - Daisuke Motooka
- Genome Information Research Center, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan; Integrated Frontier Research for Medical Science Division, Institute for Open and Transdisciplinary Research Initiatives, Osaka University, Osaka 565-0871, Japan; Single Cell Genomics, Human Immunology, WPI Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan
| | - Daisuke Okuzaki
- Genome Information Research Center, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan; Integrated Frontier Research for Medical Science Division, Institute for Open and Transdisciplinary Research Initiatives, Osaka University, Osaka 565-0871, Japan; Single Cell Genomics, Human Immunology, WPI Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan
| | - Ryota Naito
- Department of Immunochemistry, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan; Department of Rheumatology and Clinical Immunology, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Wataru Nakai
- Laboratory of Immunochemistry, World Premier International Immunology Frontier Research Centre, Osaka University, Osaka 565-0871, Japan; Department of Immunochemistry, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
| | - Teru Kanda
- Division of Microbiology, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, Sendai, Miyagi 981-8558, Japan
| | - Takayuki Murata
- Department of Virology, Graduate School of Medicine, Nagoya University, Nagoya 466-8550, Japan; Department of Virology, Fujita Health University School of Medicine, Nagoya 470-1192, Japan
| | - Chikashi Terao
- Laboratory for Statistical and Translational Genetics, RIKEN Center for Integrative Medical Sciences, Yokohama, Kanagawa 351-0198, Japan; Clinical Research Center, Shizuoka General Hospital, Shizuoka 420-8527, Japan; The Department of Applied Genetics, The School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Koichiro Ohmura
- Department of Rheumatology and Clinical Immunology, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan; Department of Rheumatology, Kobe City Medical Center General Hospital, Kobe, Hyogo 650-0047, Japan
| | - Noriko Arase
- Department of Dermatology, Graduate school of Medicine, Osaka University, Osaka 565-0871, Japan
| | - Tomohiro Kurosaki
- Laboratory of Lymphocyte Differentiation, WPI Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan
| | - Manabu Fujimoto
- Department of Dermatology, Graduate school of Medicine, Osaka University, Osaka 565-0871, Japan
| | - Tadahiro Suenaga
- Laboratory of Immunochemistry, World Premier International Immunology Frontier Research Centre, Osaka University, Osaka 565-0871, Japan; Department of Immunochemistry, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan; Department of Immunology, Kitasato University School of Medicine, Sagamihara, Kanagawa 252-0374, Japan
| | - Atsushi Kumanogoh
- Department of Respiratory Medicine and Clinical Immunology, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan; Center for advanced modalities and DDS, Osaka University, Osaka 565-0871, Japan
| | - Shimon Sakaguchi
- Department of Experimental Immunology, World Premier International Immunology Frontier Research Centre, Osaka University, Osaka 565-0871, Japan; Department of Experimental Immunology, Institute for Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
| | - Yoshihiro Ogawa
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Hisashi Arase
- Laboratory of Immunochemistry, World Premier International Immunology Frontier Research Centre, Osaka University, Osaka 565-0871, Japan; Department of Immunochemistry, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan; Center for advanced modalities and DDS, Osaka University, Osaka 565-0871, Japan; Center for Infectious Disease Education and Research, Osaka University, Osaka 565-0871, Japan.
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2
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Dwyer AJ, Shaheen ZR, Fife BT. Antigen-specific T cell responses in autoimmune diabetes. Front Immunol 2024; 15:1440045. [PMID: 39211046 PMCID: PMC11358097 DOI: 10.3389/fimmu.2024.1440045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Accepted: 07/23/2024] [Indexed: 09/04/2024] Open
Abstract
Autoimmune diabetes is a disease characterized by the selective destruction of insulin-secreting β-cells of the endocrine pancreas by islet-reactive T cells. Autoimmune disease requires a complex interplay between host genetic factors and environmental triggers that promote the activation of such antigen-specific T lymphocyte responses. Given the critical involvement of self-reactive T lymphocyte in diabetes pathogenesis, understanding how these T lymphocyte populations contribute to disease is essential to develop targeted therapeutics. To this end, several key antigenic T lymphocyte epitopes have been identified and studied to understand their contributions to disease with the aim of developing effective treatment approaches for translation to the clinical setting. In this review, we discuss the role of pathogenic islet-specific T lymphocyte responses in autoimmune diabetes, the mechanisms and cell types governing autoantigen presentation, and therapeutic strategies targeting such T lymphocyte responses for the amelioration of disease.
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Affiliation(s)
- Alexander J. Dwyer
- Center for Immunology, Department of Medicine, Division of Rheumatic and Autoimmune Diseases, University of Minnesota Medical School, Minneapolis, MN, United States
| | - Zachary R. Shaheen
- Center for Immunology, Department of Pediatrics, Pediatric Rheumatology, Allergy, & Immunology, University of Minnesota Medical School, Minneapolis, MN, United States
| | - Brian T. Fife
- Center for Immunology, Department of Medicine, Division of Rheumatic and Autoimmune Diseases, University of Minnesota Medical School, Minneapolis, MN, United States
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3
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Yang K, Zhang Y, Ding J, Li Z, Zhang H, Zou F. Autoimmune CD8+ T cells in type 1 diabetes: from single-cell RNA sequencing to T-cell receptor redirection. Front Endocrinol (Lausanne) 2024; 15:1377322. [PMID: 38800484 PMCID: PMC11116783 DOI: 10.3389/fendo.2024.1377322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Accepted: 04/18/2024] [Indexed: 05/29/2024] Open
Abstract
Type 1 diabetes (T1D) is an organ-specific autoimmune disease caused by pancreatic β cell destruction and mediated primarily by autoreactive CD8+ T cells. It has been shown that only a small number of stem cell-like β cell-specific CD8+ T cells are needed to convert normal mice into T1D mice; thus, it is likely that T1D can be cured or significantly improved by modulating or altering self-reactive CD8+ T cells. However, stem cell-type, effector and exhausted CD8+ T cells play intricate and important roles in T1D. The highly diverse T-cell receptors (TCRs) also make precise and stable targeted therapy more difficult. Therefore, this review will investigate the mechanisms of autoimmune CD8+ T cells and TCRs in T1D, as well as the related single-cell RNA sequencing (ScRNA-Seq), CRISPR/Cas9, chimeric antigen receptor T-cell (CAR-T) and T-cell receptor-gene engineered T cells (TCR-T), for a detailed and clear overview. This review highlights that targeting CD8+ T cells and their TCRs may be a potential strategy for predicting or treating T1D.
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Affiliation(s)
- Kangping Yang
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Yihan Zhang
- The Second Clinical Medicine School, Nanchang University, Nanchang, China
| | - Jiatong Ding
- The Second Clinical Medicine School, Nanchang University, Nanchang, China
| | - Zelin Li
- The First Clinical Medicine School, Nanchang University, Nanchang, China
| | - Hejin Zhang
- The Second Clinical Medicine School, Nanchang University, Nanchang, China
| | - Fang Zou
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Nanchang University, Nanchang, China
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4
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Lu X, Hayashi H, Ishikawa E, Takeuchi Y, Dychiao JVT, Nakagami H, Yamasaki S. Early acquisition of S-specific Tfh clonotypes after SARS-CoV-2 vaccination is associated with the longevity of anti-S antibodies. eLife 2024; 12:RP89999. [PMID: 38716629 PMCID: PMC11078543 DOI: 10.7554/elife.89999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2024] Open
Abstract
SARS-CoV-2 vaccines have been used worldwide to combat COVID-19 pandemic. To elucidate the factors that determine the longevity of spike (S)-specific antibodies, we traced the characteristics of S-specific T cell clonotypes together with their epitopes and anti-S antibody titers before and after BNT162b2 vaccination over time. T cell receptor (TCR) αβ sequences and mRNA expression of the S-responded T cells were investigated using single-cell TCR- and RNA-sequencing. Highly expanded 199 TCR clonotypes upon stimulation with S peptide pools were reconstituted into a reporter T cell line for the determination of epitopes and restricting HLAs. Among them, we could determine 78 S epitopes, most of which were conserved in variants of concern (VOCs). After the 2nd vaccination, T cell clonotypes highly responsive to recall S stimulation were polarized to follicular helper T (Tfh)-like cells in donors exhibiting sustained anti-S antibody titers (designated as 'sustainers'), but not in 'decliners'. Even before vaccination, S-reactive CD4+ T cell clonotypes did exist, most of which cross-reacted with environmental or symbiotic microbes. However, these clonotypes contracted after vaccination. Conversely, S-reactive clonotypes dominated after vaccination were undetectable in pre-vaccinated T cell pool, suggesting that highly responding S-reactive T cells were established by vaccination from rare clonotypes. These results suggest that de novo acquisition of memory Tfh-like cells upon vaccination may contribute to the longevity of anti-S antibody titers.
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Affiliation(s)
- Xiuyuan Lu
- Laboratory of Molecular Immunology, Immunology Frontier Research Center, Osaka UniversitySuitaJapan
| | - Hiroki Hayashi
- Department of Health Development and Medicine, Osaka University Graduate School of MedicineSuitaJapan
| | - Eri Ishikawa
- Laboratory of Molecular Immunology, Immunology Frontier Research Center, Osaka UniversitySuitaJapan
- Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka UniversitySuitaJapan
| | - Yukiko Takeuchi
- Laboratory of Molecular Immunology, Immunology Frontier Research Center, Osaka UniversitySuitaJapan
| | | | - Hironori Nakagami
- Department of Health Development and Medicine, Osaka University Graduate School of MedicineSuitaJapan
| | - Sho Yamasaki
- Laboratory of Molecular Immunology, Immunology Frontier Research Center, Osaka UniversitySuitaJapan
- Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka UniversitySuitaJapan
- Center for Infectious Disease Education and Research (CiDER), Osaka UniversitySuitaJapan
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5
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Ito E, Inuki S, Izumi Y, Takahashi M, Dambayashi Y, Ciacchi L, Awad W, Takeyama A, Shibata K, Mori S, Mak JYW, Fairlie DP, Bamba T, Ishikawa E, Nagae M, Rossjohn J, Yamasaki S. Sulfated bile acid is a host-derived ligand for MAIT cells. Sci Immunol 2024; 9:eade6924. [PMID: 38277465 PMCID: PMC11147531 DOI: 10.1126/sciimmunol.ade6924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 01/03/2024] [Indexed: 01/28/2024]
Abstract
Mucosal-associated invariant T (MAIT) cells are innate-like T cells that recognize bacterial riboflavin-based metabolites as activating antigens. Although MAIT cells are found in tissues, it is unknown whether any host tissue-derived antigens exist. Here, we report that a sulfated bile acid, cholic acid 7-sulfate (CA7S), binds the nonclassical MHC class I protein MR1 and is recognized by MAIT cells. CA7S is a host-derived metabolite whose levels were reduced by more than 98% in germ-free mice. Deletion of the sulfotransferase 2a family of enzymes (Sult2a1-8) responsible for CA7S synthesis reduced the number of thymic MAIT cells in mice. Moreover, recognition of CA7S induced MAIT cell survival and the expression of a homeostatic gene signature. By contrast, recognition of a previously described foreign antigen, 5-(2-oxopropylideneamino)-6-d-ribitylaminouracil (5-OP-RU), drove MAIT cell proliferation and the expression of inflammatory genes. Thus, CA7S is an endogenous antigen for MAIT cells, which promotes their development and function.
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Affiliation(s)
- Emi Ito
- Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
- Laboratory of Molecular Immunology, Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan
| | - Shinsuke Inuki
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Kyoto 606-8501, Japan
| | - Yoshihiro Izumi
- Division of Metabolomics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Fukuoka 812-8582, Japan
| | - Masatomo Takahashi
- Division of Metabolomics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Fukuoka 812-8582, Japan
| | - Yuki Dambayashi
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Kyoto 606-8501, Japan
| | - Lisa Ciacchi
- Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Wael Awad
- Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Ami Takeyama
- Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
- Laboratory of Molecular Immunology, Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan
| | - Kensuke Shibata
- Department of Microbiology and Immunology, Graduate School of Medicine, Yamaguchi University, Ube, Yamaguchi 755-8505, Japan
| | - Shotaro Mori
- Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
- Laboratory of Molecular Immunology, Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan
| | - Jeffrey Y. W. Mak
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia
| | - David P. Fairlie
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Takeshi Bamba
- Division of Metabolomics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Fukuoka 812-8582, Japan
| | - Eri Ishikawa
- Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
- Laboratory of Molecular Immunology, Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan
| | - Masamichi Nagae
- Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
- Laboratory of Molecular Immunology, Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan
| | - Jamie Rossjohn
- Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
- Institute of Infection and Immunity, Cardiff University, School of Medicine, Heath Park, Cardiff, UK
| | - Sho Yamasaki
- Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
- Laboratory of Molecular Immunology, Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan
- Center for Infectious Disease Education and Research (CiDER), Osaka University, Suita, Osaka, 565-0871, Japan
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6
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Moriyama T, Yoritate M, Kato N, Saika A, Kusuhara W, Ono S, Nagatake T, Koshino H, Kiya N, Moritsuka N, Tanabe R, Hidaka Y, Usui K, Chiba S, Kudo N, Nakahashi R, Igawa K, Matoba H, Tomooka K, Ishikawa E, Takahashi S, Kunisawa J, Yamasaki S, Hirai G. Linkage-Editing Pseudo-Glycans: A Reductive α-Fluorovinyl- C-Glycosylation Strategy to Create Glycan Analogs with Altered Biological Activities. J Am Chem Soc 2024; 146:2237-2247. [PMID: 38196121 DOI: 10.1021/jacs.3c12581] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2024]
Abstract
The acetal (O-glycoside) bonds of glycans and glycoconjugates are chemically and biologically vulnerable, and therefore C-glycosides are of interest as more stable analogs. We hypothesized that, if the O-glycoside linkage plays a vital role in glycan function, the biological activities of C-glycoside analogs would vary depending on their substituents. Based on this idea, we adopted a "linkage-editing strategy" for the creation of glycan analogs (pseudo-glycans). We designed three types of pseudo-glycans with CH2 and CHF linkages, which resemble the O-glycoside linkage in terms of bond lengths, angles, and bulkiness, and synthesized them efficiently by means of fluorovinyl C-glycosylation and selective hydrogenation reactions. Application of this strategy to isomaltose (IM), an inducer of amylase expression, and α-GalCer, which activates iNKT cells, resulted in the discovery of CH2-IM, which shows increased amylase production ability, and CHF-α-GalCer, which shows activity opposite that of native α-GalCer, serving as an antagonist of iNKT cells.
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Affiliation(s)
- Takahiro Moriyama
- Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Makoto Yoritate
- Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Naoki Kato
- Faculty of Agriculture, Setsunan University, 45-1 Nagaotoge-cho, Hirakata, Osaka 573-0101, Japan
- RIKEN Center for Sustainable Resource Science, 2-1, Hirosawa, Wako, Saitama 351-0198, Japan
| | - Azusa Saika
- Microbial Research Center for Health and Medicine, National Institutes of Biomedical Innovation, Health and Nutrition, 7-6-8 Asagi-Saito, Ibaraki, Osaka 567-0085, Japan
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, 11 Biopolis Way, Helios, Singapore 138667, Singapore
| | - Wakana Kusuhara
- Research Institute for Microbial Diseases, Osaka University, Yamadaoka, Suita, Osaka 565-0871, Japan
- Immunology Frontier Research Center, Osaka University, Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Shunsuke Ono
- Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Takahiro Nagatake
- Microbial Research Center for Health and Medicine, National Institutes of Biomedical Innovation, Health and Nutrition, 7-6-8 Asagi-Saito, Ibaraki, Osaka 567-0085, Japan
- Department of Life Sciences, School of Agriculture, Meiji University, 1-1-1 Higashi-Mita, Tama, Kawasaki, Kanagawa 214-8571, Japan
| | - Hiroyuki Koshino
- RIKEN Center for Sustainable Resource Science, 2-1, Hirosawa, Wako, Saitama 351-0198, Japan
| | - Noriaki Kiya
- Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Natsuho Moritsuka
- Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Riko Tanabe
- Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Yu Hidaka
- Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Kazuteru Usui
- Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Suzuka Chiba
- Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Noyuri Kudo
- Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Rintaro Nakahashi
- Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Kazunobu Igawa
- Institute for Materials Chemistry and Engineering, IRCCS, Kyushu University, Kasuga, Fukuoka 816-8580, Japan
| | - Hiroaki Matoba
- Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Katsuhiko Tomooka
- Institute for Materials Chemistry and Engineering, IRCCS, Kyushu University, Kasuga, Fukuoka 816-8580, Japan
| | - Eri Ishikawa
- Research Institute for Microbial Diseases, Osaka University, Yamadaoka, Suita, Osaka 565-0871, Japan
- Immunology Frontier Research Center, Osaka University, Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Shunji Takahashi
- RIKEN Center for Sustainable Resource Science, 2-1, Hirosawa, Wako, Saitama 351-0198, Japan
| | - Jun Kunisawa
- Microbial Research Center for Health and Medicine, National Institutes of Biomedical Innovation, Health and Nutrition, 7-6-8 Asagi-Saito, Ibaraki, Osaka 567-0085, Japan
| | - Sho Yamasaki
- Research Institute for Microbial Diseases, Osaka University, Yamadaoka, Suita, Osaka 565-0871, Japan
- Immunology Frontier Research Center, Osaka University, Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Go Hirai
- Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
- RIKEN Center for Sustainable Resource Science, 2-1, Hirosawa, Wako, Saitama 351-0198, Japan
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7
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Morita R, Kubota-Koketsu R, Lu X, Sasaki T, Nakayama EE, Liu YC, Okuzaki D, Motooka D, Wing JB, Fujikawa Y, Ichida Y, Amo K, Goto T, Hara J, Shirano M, Yamasaki S, Shioda T. COVID-19 relapse associated with SARS-CoV-2 evasion from CD4 + T-cell recognition in an agammaglobulinemia patient. iScience 2023; 26:106685. [PMID: 37124420 PMCID: PMC10116114 DOI: 10.1016/j.isci.2023.106685] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 03/27/2023] [Accepted: 04/12/2023] [Indexed: 05/02/2023] Open
Abstract
A 25-year-old patient with a primary immunodeficiency lacking immunoglobulin production experienced a relapse after a 239-day period of persistent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Viral genetic sequencing demonstrated that SARS-CoV-2 had evolved during the infection period, with at least five mutations associated with host cellular immune recognition. Among them, the T32I mutation in ORF3a was found to evade recognition by CD4+ T cells. The virus found after relapse showed an increased proliferative capacity in vitro. SARS-CoV-2 may have evolved to evade recognition by CD4+ T cells and increased in its proliferative capacity during the persistent infection, likely leading to relapse. These mutations may further affect viral clearance in hosts with similar types of human leukocyte antigens. The early elimination of SARS-CoV-2 in immunocompromised patients is therefore important not only to improve the condition of patients but also to prevent the emergence of mutants that threaten public health.
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Affiliation(s)
- Ryo Morita
- Department of Infectious Diseases, Osaka City General Hospital, Osaka 534-0021, Japan
- Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
| | - Ritsuko Kubota-Koketsu
- Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
| | - Xiuyuan Lu
- Laboratory of Molecular Immunology, Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan
| | - Tadahiro Sasaki
- Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
| | - Emi E Nakayama
- Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
| | - Yu-Chen Liu
- Laboratory of Human Immunology (Single Cell Genomics), Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan
| | - Daisuke Okuzaki
- Laboratory of Human Immunology (Single Cell Genomics), Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan
| | - Daisuke Motooka
- Department of Infection Metagenomics, Genome Information Research Center, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
| | - James Badger Wing
- Laboratory of Human Immunology (Single Cell Immunology), Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan
| | - Yasunori Fujikawa
- Department of Medical Laboratory, Osaka City General Hospital, Osaka 534-0021, Japan
| | - Yuji Ichida
- Department of Pharmacy, Osaka City General Hospital, Osaka 534-0021, Japan
| | - Kiyoko Amo
- Department of Pediatric Emergency Medicine, Osaka City General Hospital, Osaka 534-0021, Japan
| | - Tetsushi Goto
- Department of Infectious Diseases, Osaka City General Hospital, Osaka 534-0021, Japan
| | - Junichi Hara
- Department of Pediatric Hematology and Oncology, Osaka City General Hospital, Osaka 534-0021, Japan
| | - Michinori Shirano
- Department of Infectious Diseases, Osaka City General Hospital, Osaka 534-0021, Japan
| | - Sho Yamasaki
- Laboratory of Molecular Immunology, Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan
| | - Tatsuo Shioda
- Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
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8
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Li Y, Jiang W, Mellins ED. TCR-like antibodies targeting autoantigen-mhc complexes: a mini-review. Front Immunol 2022; 13:968432. [PMID: 35967436 PMCID: PMC9363607 DOI: 10.3389/fimmu.2022.968432] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 07/06/2022] [Indexed: 11/13/2022] Open
Abstract
T cell receptors (TCRs) recognize peptide antigens bound to major histocompatibility complex (MHC) molecules (p/MHC) that are expressed on cell surfaces; while B cell-derived antibodies (Abs) recognize soluble or cell surface native antigens of various types (proteins, carbohydrates, etc.). Immune surveillance by T and B cells thus inspects almost all formats of antigens to mount adaptive immune responses against cancer cells, infectious organisms and other foreign insults, while maintaining tolerance to self-tissues. With contributions from environmental triggers, the development of autoimmune disease is thought to be due to the expression of MHC risk alleles by antigen-presenting cells (APCs) presenting self-antigen (autoantigen), breaking through self-tolerance and activating autoreactive T cells, which orchestrate downstream pathologic events. Investigating and treating autoimmune diseases have been challenging, both because of the intrinsic complexity of these diseases and the need for tools targeting T cell epitopes (autoantigen-MHC). Naturally occurring TCRs with relatively low (micromolar) affinities to p/MHC are suboptimal for autoantigen-MHC targeting, whereas the use of engineered TCRs and their derivatives (e.g., TCR multimers and TCR-engineered T cells) are limited by unpredictable cross-reactivity. As Abs generally have nanomolar affinity, recent advances in engineering TCR-like (TCRL) Abs promise advantages over their TCR counterparts for autoantigen-MHC targeting. Here, we compare the p/MHC binding by TCRs and TCRL Abs, review the strategies for generation of TCRL Abs, highlight their application for identification of autoantigen-presenting APCs, and discuss future directions and limitations of TCRL Abs as immunotherapy for autoimmune diseases.
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Affiliation(s)
- Ying Li
- Department of Pediatrics, Divisions of Human Gene Therapy and Allergy, Immunology & Rheumatology, Stanford University School of Medicine, Stanford, CA, United States
- Stanford Program in Immunology, Stanford University School of Medicine, Stanford, CA, United States
| | - Wei Jiang
- Department of Pediatrics, Divisions of Human Gene Therapy and Allergy, Immunology & Rheumatology, Stanford University School of Medicine, Stanford, CA, United States
- Stanford Program in Immunology, Stanford University School of Medicine, Stanford, CA, United States
- *Correspondence: Wei Jiang, ; Elizabeth D. Mellins,
| | - Elizabeth D. Mellins
- Department of Pediatrics, Divisions of Human Gene Therapy and Allergy, Immunology & Rheumatology, Stanford University School of Medicine, Stanford, CA, United States
- Stanford Program in Immunology, Stanford University School of Medicine, Stanford, CA, United States
- *Correspondence: Wei Jiang, ; Elizabeth D. Mellins,
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9
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Shibata K, Shimizu T, Nakahara M, Ito E, Legoux F, Fujii S, Yamada Y, Furutani-Seiki M, Lantz O, Yamasaki S, Watarai M, Shirai M. The intracellular pathogen Francisella tularensis escapes from adaptive immunity by metabolic adaptation. Life Sci Alliance 2022; 5:5/10/e202201441. [PMID: 35667686 PMCID: PMC9170078 DOI: 10.26508/lsa.202201441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 05/12/2022] [Accepted: 05/13/2022] [Indexed: 11/24/2022] Open
Abstract
This study shows that metabolic adaptation allows the intracellular bacterial pathogen Francisella tularensis to escape recognition by the host adaptive immunity. Intracellular pathogens lose many metabolic genes during their evolution from free-living bacteria, but the pathogenic consequences of their altered metabolic programs on host immunity are poorly understood. Here, we show that a pathogenic strain of Francisella tularensis subsp. tularensis (FT) has five amino acid substitutions in RibD, a converting enzyme of the riboflavin synthetic pathway responsible for generating metabolites recognized by mucosal-associated invariant T (MAIT) cells. Metabolites from a free-living strain, F. tularensis subsp. novicida (FN), activated MAIT cells in a T-cell receptor (TCR)–dependent manner, whereas introduction of FT-type ribD to the free-living strain was sufficient to attenuate this activation in both human and mouse MAIT cells. Intranasal infection in mice showed that the ribDFT-expressing FN strain induced impaired Th1-type MAIT cell expansion and resulted in reduced bacterial clearance and worsened survival compared with the wild-type free-living strain FN. These results demonstrate that F. tularensis can acquire immune evasion capacity by alteration of metabolic programs during evolution.
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Affiliation(s)
- Kensuke Shibata
- Department of Microbiology and Immunology, Graduate School of Medicine, Yamaguchi University, Yamaguchi, Japan .,Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.,Department of Ophthalmology, Department of Ocular Pathology and Imaging Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Takashi Shimizu
- Joint Faculty of Veterinary Medicine, Laboratory of Veterinary Public Health, Yamaguchi University, Yamaguchi, Japan
| | - Mashio Nakahara
- Department of Microbiology and Immunology, Graduate School of Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Emi Ito
- Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | | | - Shotaro Fujii
- Department of Microbiology and Immunology, Graduate School of Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Yuka Yamada
- Department of Microbiology and Immunology, Graduate School of Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Makoto Furutani-Seiki
- Systems Biochemistry in Pathology and Regeneration, Graduate School of Medicine, Yamaguchi University, Ube, Japan
| | - Olivier Lantz
- INSERM U932, PSL University, Laboratoire d'Immunologie Clinique, Centre d'Investigation Clinique en Biothérapie, Institut Curie (CIC-BT1428), Paris, France
| | - Sho Yamasaki
- Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.,Laboratory of Molecular Immunology, Immunology Frontier Research Center, Osaka University, Osaka, Japan.,Division of Molecular Design, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan.,Division of Molecular Immunology, Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Masahisa Watarai
- Joint Faculty of Veterinary Medicine, Laboratory of Veterinary Public Health, Yamaguchi University, Yamaguchi, Japan
| | - Mutsunori Shirai
- Department of Microbiology and Immunology, Graduate School of Medicine, Yamaguchi University, Yamaguchi, Japan
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10
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Lu X, Hosono Y, Nagae M, Ishizuka S, Ishikawa E, Motooka D, Ozaki Y, Sax N, Maeda Y, Kato Y, Morita T, Shinnakasu R, Inoue T, Onodera T, Matsumura T, Shinkai M, Sato T, Nakamura S, Mori S, Kanda T, Nakayama EE, Shioda T, Kurosaki T, Takeda K, Kumanogoh A, Arase H, Nakagami H, Yamashita K, Takahashi Y, Yamasaki S. Identification of conserved SARS-CoV-2 spike epitopes that expand public cTfh clonotypes in mild COVID-19 patients. J Exp Med 2021; 218:212701. [PMID: 34647971 PMCID: PMC8641254 DOI: 10.1084/jem.20211327] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 08/21/2021] [Accepted: 09/28/2021] [Indexed: 11/04/2022] Open
Abstract
Adaptive immunity is a fundamental component in controlling COVID-19. In this process, follicular helper T (Tfh) cells are a subset of CD4+ T cells that mediate the production of protective antibodies; however, the SARS-CoV-2 epitopes activating Tfh cells are not well characterized. Here, we identified and crystallized TCRs of public circulating Tfh (cTfh) clonotypes that are expanded in patients who have recovered from mild symptoms. These public clonotypes recognized the SARS-CoV-2 spike (S) epitopes conserved across emerging variants. The epitope of the most prevalent cTfh clonotype, S864-882, was presented by multiple HLAs and activated T cells in most healthy donors, suggesting that this S region is a universal T cell epitope useful for booster antigen. SARS-CoV-2-specific public cTfh clonotypes also cross-reacted with specific commensal bacteria. In this study, we identified conserved SARS-CoV-2 S epitopes that activate public cTfh clonotypes associated with mild symptoms.
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Affiliation(s)
- Xiuyuan Lu
- Laboratory of Molecular Immunology, Immunology Frontier Research Center, Osaka University, Suita, Japan
| | - Yuki Hosono
- Laboratory of Molecular Immunology, Immunology Frontier Research Center, Osaka University, Suita, Japan.,Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka University, Suita, Japan.,Department of Respiratory Medicine and Clinical Immunology, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Masamichi Nagae
- Laboratory of Molecular Immunology, Immunology Frontier Research Center, Osaka University, Suita, Japan.,Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | - Shigenari Ishizuka
- Laboratory of Molecular Immunology, Immunology Frontier Research Center, Osaka University, Suita, Japan.,Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | - Eri Ishikawa
- Laboratory of Molecular Immunology, Immunology Frontier Research Center, Osaka University, Suita, Japan.,Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | - Daisuke Motooka
- Department of Infection Metagenomics, Genome Information Research Center, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | - Yuki Ozaki
- Department of Infection Metagenomics, Genome Information Research Center, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | | | - Yuichi Maeda
- Department of Respiratory Medicine and Clinical Immunology, Graduate School of Medicine, Osaka University, Suita, Japan.,Laboratory of Immune Regulation, Department of Microbiology and Immunology, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Yasuhiro Kato
- Department of Respiratory Medicine and Clinical Immunology, Graduate School of Medicine, Osaka University, Suita, Japan.,Department of Immunopathology, Immunology Frontier Research Center, Osaka University, Suita, Japan
| | - Takayoshi Morita
- Department of Respiratory Medicine and Clinical Immunology, Graduate School of Medicine, Osaka University, Suita, Japan.,Department of Immunopathology, Immunology Frontier Research Center, Osaka University, Suita, Japan
| | - Ryo Shinnakasu
- Laboratory of Lymphocyte Differentiation, Immunology Frontier Research Center, Osaka University, Suita, Japan
| | - Takeshi Inoue
- Laboratory of Lymphocyte Differentiation, Immunology Frontier Research Center, Osaka University, Suita, Japan
| | - Taishi Onodera
- Research Center for Drug and Vaccine Development, National Institute of Infectious Diseases, Tokyo, Japan
| | - Takayuki Matsumura
- Research Center for Drug and Vaccine Development, National Institute of Infectious Diseases, Tokyo, Japan
| | | | | | - Shota Nakamura
- Department of Infection Metagenomics, Genome Information Research Center, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | - Shunsuke Mori
- Department of Immunochemistry, Research Institute for Microbial Diseases, Osaka University, Suita, Japan.,Laboratory of Immunochemistry, Immunology Frontier Research Center, Osaka University, Suita, Japan
| | - Teru Kanda
- Division of Microbiology, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Emi E Nakayama
- Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | - Tatsuo Shioda
- Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University, Suita, Japan.,Center for Infectious Disease Education and Research, Osaka University, Suita, Japan
| | - Tomohiro Kurosaki
- Laboratory of Lymphocyte Differentiation, Immunology Frontier Research Center, Osaka University, Suita, Japan.,Center for Infectious Disease Education and Research, Osaka University, Suita, Japan.,Laboratory of Lymphocyte Differentiation, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
| | - Kiyoshi Takeda
- Laboratory of Immune Regulation, Department of Microbiology and Immunology, Graduate School of Medicine, Osaka University, Suita, Japan.,Center for Infectious Disease Education and Research, Osaka University, Suita, Japan.,Department of Mucosal Immunology, Immunology Frontier Research Center, Osaka University, Suita, Japan
| | - Atsushi Kumanogoh
- Department of Respiratory Medicine and Clinical Immunology, Graduate School of Medicine, Osaka University, Suita, Japan.,Department of Immunopathology, Immunology Frontier Research Center, Osaka University, Suita, Japan.,Center for Infectious Disease Education and Research, Osaka University, Suita, Japan
| | - Hisashi Arase
- Department of Immunochemistry, Research Institute for Microbial Diseases, Osaka University, Suita, Japan.,Laboratory of Immunochemistry, Immunology Frontier Research Center, Osaka University, Suita, Japan.,Center for Infectious Disease Education and Research, Osaka University, Suita, Japan
| | - Hironori Nakagami
- Department of Health Development and Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
| | | | - Yoshimasa Takahashi
- Research Center for Drug and Vaccine Development, National Institute of Infectious Diseases, Tokyo, Japan
| | - Sho Yamasaki
- Laboratory of Molecular Immunology, Immunology Frontier Research Center, Osaka University, Suita, Japan.,Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka University, Suita, Japan.,Center for Infectious Disease Education and Research, Osaka University, Suita, Japan.,Division of Molecular Immunology, Medical Mycology Research Center, Chiba University, Chiba, Japan.,Division of Molecular Design, Research Center for Systems Immunology, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
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11
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Non-Genetically Encoded Epitopes Are Relevant Targets in Autoimmune Diabetes. Biomedicines 2021; 9:biomedicines9020202. [PMID: 33671312 PMCID: PMC7922826 DOI: 10.3390/biomedicines9020202] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 02/10/2021] [Accepted: 02/12/2021] [Indexed: 12/16/2022] Open
Abstract
Islet antigen reactive T cells play a key role in promoting beta cell destruction in type 1 diabetes (T1D). Self-reactive T cells are typically deleted through negative selection in the thymus or deviated to a regulatory phenotype. Nevertheless, those processes are imperfect such that even healthy individuals have a reservoir of potentially autoreactive T cells. What remains less clear is how tolerance is lost to insulin and other beta cell specific antigens. Islet autoantibodies, the best predictor of disease risk, are known to recognize classical antigens such as proinsulin, GAD65, IA-2, and ZnT8. These antibodies are thought to be supported by the expansion of autoreactive CD4+ T cells that recognize these same antigenic targets. However, recent studies have identified new classes of non-genetically encoded epitopes that may reflect crucial gaps in central and peripheral tolerance. Notably, some of these specificities, including epitopes from enzymatically post-translationally modified antigens and hybrid insulin peptides, are present at relatively high frequencies in the peripheral blood of patients with T1D. We conclude that CD4+ T cells that recognize non-genetically encoded epitopes are likely to make an important contribution to the progression of islet autoimmunity in T1D. We further propose that these classes of neo-epitopes should be considered as possible targets for strategies to induce antigen specific tolerance.
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