title: MAIT cells are activated and accumulated in the inflamed mucosa of ulcerative colitis.
abstract: OBJECTIVE
  Ulcerative colitis (UC) is a chronic, relapsing and remitting, inflammatory disorder of the large intestine. Mucosal associated invariant T (MAIT) cells are a member of innate-like lymphocytes found abundantly in the mucosal tissue. The contribution of MAIT cells in the pathogenesis of UC is still unclear; therefore, this study aimed at investigating the role of these cells in patients with UC.
  
  
  METHODS
  The frequency of MAIT cells, as well as the production of cytokines and expression levels of activation markers by these cells in the peripheral blood of UC patients and healthy controls, was analyzed by flow cytometry. MAIT cells were also quantified in colon biopsies of UC patients using a confocal microscope.
  
  
  RESULTS
  There was a significant reduction in MAIT cell frequency in the peripheral blood of UC patients compared with healthy controls (P < 0.0001). MAIT cells from UC patients secreted more interleukin (IL)-17 than healthy controls (P < 0.05). The expression levels of CD69 on these cells were correlated with disease activity and endoscopic scores and plasma levels of IL-18. Furthermore, MAIT cells increased in the inflamed mucosa, and their frequency was correlated with clinical and endoscopic disease activity in UC patients.
  
  
  CONCLUSIONS
  The findings from this study indicate that MAIT cells could be associated with UC and may serve as potential biomarkers or therapeutic targets in UC.
authors.affiliation: Departments of Immunology, Juntendo University School of Medicine, Tokyo, Japan.|Department of Gastroenterology, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Haga
authors.affiliation: Departments of Immunology, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Asako
authors.initials: A
authors.lastname: Chiba
authors.affiliation: Department of Gastroenterology, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Tomoyoshi
authors.initials: T
authors.lastname: Shibuya
authors.affiliation: Department of Gastroenterology, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Taro
authors.initials: T
authors.lastname: Osada
authors.affiliation: Department of Gastroenterology, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Dai
authors.initials: D
authors.lastname: Ishikawa
authors.affiliation: Department of Gastroenterology, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Kodani
authors.affiliation: Department of Gastroenterology, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Nomura
authors.affiliation: Department of Gastroenterology, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Sumio
authors.initials: S
authors.lastname: Watanabe
authors.affiliation: Departments of Immunology, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Miyake
mesh_terms: D000328:Adult; D015703:Antigens, CD / Q000378:metabolism; D000945:Antigens, Differentiation, T-Lymphocyte / Q000378:metabolism; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D016923:Cell Death; D002634:Chemotaxis, Leukocyte; D003093:Colitis, Ulcerative / Q000097:blood / Q000276:immunology* / Q000473:pathology; D003106:Colon / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D016207:Cytokines / Q000097:blood; D005260:Female; D006801:Humans; D007113:Immunity, Innate; D018836:Inflammation Mediators / Q000097:blood; D007413:Intestinal Mucosa / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D037181:Lectins, C-Type / Q000378:metabolism; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D000072336:Mucosal-Associated Invariant T Cells / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D012720:Severity of Illness Index; D000099192:CD69 Antigens
chemical_list: D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D015415:Biomarkers; D016207:Cytokines; D018836:Inflammation Mediators; D037181:Lectins, C-Type; D000099192:CD69 Antigens
keywords: MAIT cells; activation marker; inflammatory bowel diseases; ulcerative colitis