title: Mucosal-associated invariant T cells are reduced and functionally immature in the peripheral blood of primary Sjögren's syndrome patients.
abstract: The frequencies, immunophenotype, and function of mucosal-associated invariant T (MAIT) cells were studied in patients with primary Sjögren syndrome (pSS) and healthy controls. MAIT cells were significantly decreased in the peripheral blood (PB) of patients with pSS. Vα7.2+MAIT cells were detected in the salivary gland tissue from pSS patients, but not in controls, indicating that the reduction of MAIT cells in PB might be due to migration into the target tissue. Furthermore, the residual peripheral blood MAIT cells in pSS patients showed altered immunophenotype and function. While MAIT cells from controls were almost exclusively CD8+and expressed an effector memory immunophenotype, in pSS patients they were enriched in CD4+and naïve subpopulations. Consistently, the functional studies demonstrated that MAIT cells from pSS showed a lower level of activation with reduced expression of CD69 and CD154 (CD40L), and a lower production of TNF and IFN-γ. In summary, our findings demonstrate that MAIT cells were reduced and phenotypically and functionally altered in PB of pSS patients. The altered function of MAIT cells in target tissues from pSS patients may result in dysregulation of mucosal immunity leading to microbial damage of mucosal surfaces and subsequent initiation of autoimmune response.
authors.affiliation: Department of Immunology, SA Pathology, Flinders Medical Centre, Bedford Park, South Australia.|Department of Immunology, Flinders University, Bedford Park, South Australia.
authors.forename: Jing J
authors.initials: JJ
authors.lastname: Wang
authors.affiliation: Department of Immunology, SA Pathology, Flinders Medical Centre, Bedford Park, South Australia.|Department of Immunology, Flinders University, Bedford Park, South Australia.
authors.forename: Cindy
authors.initials: C
authors.lastname: Macardle
authors.affiliation: Rheumatology Research Unit, Repatriation General Hospital, Daw Park, Adelaide, South Australia.
authors.forename: Helen
authors.initials: H
authors.lastname: Weedon
authors.affiliation: Department of Immunology, SA Pathology, Flinders Medical Centre, Bedford Park, South Australia.|Department of Immunology, Flinders University, Bedford Park, South Australia.
authors.forename: Dimitra
authors.initials: D
authors.lastname: Beroukas
authors.affiliation: Department of Immunology, SA Pathology, Flinders Medical Centre, Bedford Park, South Australia. tatjana.banovic@sa.gov.au.|Department of Immunology, Flinders University, Bedford Park, South Australia. tatjana.banovic@sa.gov.au.|Department of Immunology, SA Pathology, IMVS, Adelaide, South Australia. tatjana.banovic@sa.gov.au.|Department of Clinical Immunology and Allergy, Royal Adelaide Hospital, Adelaide, South Australia. tatjana.banovic@sa.gov.au.|Discipline of Pediatrics, School of Pediatrics and Reproductive Health, Faculty of Health Sciences, University of Adelaide, Adelaide, South Australia. tatjana.banovic@sa.gov.au.
authors.forename: Tatjana
authors.initials: T
authors.lastname: Banovic
mesh_terms: D000328:Adult; D001773:Blood Cells / Q000276:immunology*; D002454:Cell Differentiation; D049109:Cell Proliferation; D015331:Cohort Studies; D005260:Female; D006801:Humans; D018928:Immunity, Mucosal; D007156:Immunologic Memory; D007371:Interferon-gamma / Q000378:metabolism; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D055611:Natural Killer T-Cells / Q000276:immunology*; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics; D012859:Sjogren's Syndrome / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D016693:Receptors, Antigen, T-Cell, alpha-beta; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma
keywords: Immunity; Mucosal-associated invariant T cell; Primary Sjögren syndrome