title: Circulating gluten-specific FOXP3+CD39+regulatory T cells have impaired suppressive function in patients with celiac disease.
abstract: BACKGROUND
  Celiac disease is a chronic immune-mediated inflammatory disorder of the gut triggered by dietary gluten. Although the effector T-cell response in patients with celiac disease has been well characterized, the role of regulatory T (Treg) cells in the loss of tolerance to gluten remains poorly understood.
  
  
  OBJECTIVE
  We sought to define whether patients with celiac disease have a dysfunction or lack of gluten-specific forkhead box protein 3 (FOXP3)+Treg cells.
  
  
  METHODS
  Treated patients with celiac disease underwent oral wheat challenge to stimulate recirculation of gluten-specific T cells. Peripheral blood was collected before and after challenge. To comprehensively measure the gluten-specific CD4+T-cell response, we paired traditional IFN-γ ELISpot with an assay to detect antigen-specific CD4+T cells that does not rely on tetramers, antigen-stimulated cytokine production, or proliferation but rather on antigen-induced coexpression of CD25 and OX40 (CD134).
  
  
  RESULTS
  Numbers of circulating gluten-specific Treg cells and effector T cells both increased significantly after oral wheat challenge, peaking at day 6. Surprisingly, we found that approximately 80% of the ex vivo circulating gluten-specific CD4+T cells were FOXP3+CD39+Treg cells, which reside within the pool of memory CD4+CD25+CD127lowCD45RO+Treg cells. Although we observed normal suppressive function in peripheral polyclonal Treg cells from patients with celiac disease, after a short in vitro expansion, the gluten-specific FOXP3+CD39+Treg cells exhibited significantly reduced suppressive function compared with polyclonal Treg cells.
  
  
  CONCLUSIONS
  This study provides the first estimation of FOXP3+CD39+Treg cell frequency within circulating gluten-specific CD4+T cells after oral gluten challenge of patients with celiac disease. FOXP3+CD39+Treg cells comprised a major proportion of all circulating gluten-specific CD4+T cells but had impaired suppressive function, indicating that Treg cell dysfunction might be a key contributor to disease pathogenesis.
authors.affiliation: Immunovirology and Pathogenesis Program, The Kirby Institute, UNSW Sydney, Sydney, Australia; St Vincent's Centre for Applied Medical Research, St Vincent's Hospital, Sydney, Australia. Electronic address: lcook@bcchr.ca.
authors.forename: Laura
authors.initials: L
authors.lastname: Cook
authors.affiliation: Immunovirology and Pathogenesis Program, The Kirby Institute, UNSW Sydney, Sydney, Australia.
authors.forename: C Mee Ling
authors.initials: CML
authors.lastname: Munier
authors.affiliation: Immunovirology and Pathogenesis Program, The Kirby Institute, UNSW Sydney, Sydney, Australia; St Vincent's Centre for Applied Medical Research, St Vincent's Hospital, Sydney, Australia.
authors.forename: Nabila
authors.initials: N
authors.lastname: Seddiki
authors.affiliation: Immunovirology and Pathogenesis Program, The Kirby Institute, UNSW Sydney, Sydney, Australia.
authors.forename: David
authors.initials: D
authors.lastname: van Bockel
authors.affiliation: Immunology Division, Walter and Eliza Hall Institute, Parkville, Australia; Department of Medical Biology, University of Melbourne, Parkville, Australia.
authors.forename: Noé
authors.initials: N
authors.lastname: Ontiveros
authors.affiliation: Immunology Division, Walter and Eliza Hall Institute, Parkville, Australia; Department of Medical Biology, University of Melbourne, Parkville, Australia.
authors.forename: Melinda Y
authors.initials: MY
authors.lastname: Hardy
authors.affiliation: Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Jana K
authors.initials: JK
authors.lastname: Gillies
authors.affiliation: Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Megan K
authors.initials: MK
authors.lastname: Levings
authors.affiliation: Infection and Immunity Program, The Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Australia; Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Australia.
authors.forename: Hugh H
authors.initials: HH
authors.lastname: Reid
authors.affiliation: Infection and Immunity Program, The Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Australia; Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Australia.
authors.forename: Jan
authors.initials: J
authors.lastname: Petersen
authors.affiliation: Infection and Immunity Program, The Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Australia; Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Australia; Institute of Infection and Immunity, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom.
authors.forename: Jamie
authors.initials: J
authors.lastname: Rossjohn
authors.affiliation: Immunology Division, Walter and Eliza Hall Institute, Parkville, Australia; Department of Medical Biology, University of Melbourne, Parkville, Australia; ImmusanT, Cambridge, Mass.
authors.forename: Robert P
authors.initials: RP
authors.lastname: Anderson
authors.affiliation: Immunovirology and Pathogenesis Program, The Kirby Institute, UNSW Sydney, Sydney, Australia; St Vincent's Centre for Applied Medical Research, St Vincent's Hospital, Sydney, Australia.
authors.forename: John J
authors.initials: JJ
authors.lastname: Zaunders
authors.affiliation: Immunology Division, Walter and Eliza Hall Institute, Parkville, Australia; Department of Medical Biology, University of Melbourne, Parkville, Australia; Department of Gastroenterology, Royal Melbourne Hospital, Parkville, Australia.
authors.forename: Jason A
authors.initials: JA
authors.lastname: Tye-Din
authors.affiliation: Immunovirology and Pathogenesis Program, The Kirby Institute, UNSW Sydney, Sydney, Australia; St Vincent's Centre for Applied Medical Research, St Vincent's Hospital, Sydney, Australia.
authors.forename: Anthony D
authors.initials: AD
authors.lastname: Kelleher
mesh_terms: D000328:Adult; D015703:Antigens, CD / Q000378:metabolism; D001081:Apyrase / Q000378:metabolism; D002446:Celiac Disease / Q000276:immunology*; D002478:Cells, Cultured; D058501:Enzyme-Linked Immunospot Assay; D005260:Female; D051858:Forkhead Transcription Factors / Q000378:metabolism; D005983:Glutens / Q000276:immunology*; D006683:HLA-DQ Antigens / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007165:Immunosuppression Therapy; D007371:Interferon-gamma / Q000378:metabolism; D018655:Lymphocyte Count; D008297:Male; D020641:Polymorphism, Single Nucleotide; D037182:T-Cell Antigen Receptor Specificity / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: D015703:Antigens, CD; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D006683:HLA-DQ Antigens; C053186:HLA-DQ2 antigen; D005983:Glutens; D007371:Interferon-gamma; D001081:Apyrase; C067869:CD39 antigen
keywords: CD39; OX40; Regulatory T cells; celiac disease; forkhead box protein 3; gluten