title: Diabetes-specific HLA-DR-restricted proinflammatory T-cell response to wheat polypeptides in tissue transglutaminase antibody-negative patients with type 1 diabetes.
abstract: OBJECTIVE
  There is evidence of gut barrier and immune system dysfunction in some patients with type 1 diabetes, possibly linked with exposure to dietary wheat polypeptides (WP). However, questions arise regarding the frequency of abnormal immune responses to wheat and their nature, and it remains unclear whether such responses are diabetes specific.
  
  
  METHODS
  In type 1 diabetic patients and healthy control subjects, the immune response of peripheral CD3(+) T-cells to WPs, ovalbumin, gliadin, alpha-gliadin 33-mer peptide, tetanus toxoid, and phytohemagglutinin was measured using a carboxyfluorescein diacetate succinimidyl ester (CFSE) proliferation assay. T-helper cell type 1 (Th1), Th2, and Th17 cytokines were analyzed in WP-stimulated peripheral blood mononuclear cell (PBMNC) supernatants, and HLA was analyzed by PCR.
  
  
  RESULTS
  Of 42 patients, 20 displayed increased CD3(+) T-cell proliferation to WPs and were classified as responders; proliferative responses to other dietary antigens were less pronounced. WP-stimulated PBMNCs from patients showed a mixed proinflammatory cytokine response with large amounts of IFN-gamma, IL-17A, and increased TNF. HLA-DQ2, the major celiac disease risk gene, was not significantly different. Nearly all responders carried the diabetes risk gene HLA-DR4. Anti-DR antibodies blocked the WP response and inhibited secretion of Th1 and Th17 cytokines. High amounts of WP-stimulated IL-6 were not blocked.
  
  
  CONCLUSIONS
  T-cell reactivity to WPs was frequently present in type 1 diabetic patients and associated with HLA-DR4 but not HLA-DQ2. The presence of an HLA-DR-restricted Th1 and Th17 response to WPs in a subset of patients indicates a diabetes-related inflammatory state in the gut immune tissues associated with defective oral tolerance and possibly gut barrier dysfunction.
authors.affiliation: Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, Canada.
authors.forename: Majid
authors.initials: M
authors.lastname: Mojibian
authors.forename: Habiba
authors.initials: H
authors.lastname: Chakir
authors.forename: David E
authors.initials: DE
authors.lastname: Lefebvre
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Crookshank
authors.forename: Brigitte
authors.initials: B
authors.lastname: Sonier
authors.forename: Erin
authors.initials: E
authors.lastname: Keely
authors.forename: Fraser W
authors.initials: FW
authors.lastname: Scott
mesh_terms: D000293:Adolescent; D000328:Adult; D015703:Antigens, CD / Q000276:immunology; D017252:CD3 Complex / Q000276:immunology; D002648:Child; D016207:Cytokines / Q000097:blood; D003922:Diabetes Mellitus, Type 1 / Q000276:immunology*; D006683:HLA-DQ Antigens / Q000276:immunology; D015804:HLA-DR4 Antigen / Q000276:immunology; D006650:Histocompatibility Testing; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology*; D010455:Peptides / Q000276:immunology*; D012016:Reference Values; D013601:T-Lymphocytes / Q000276:immunology*; D014908:Triticum / Q000276:immunology*; D055815:Young Adult
chemical_list: D015703:Antigens, CD; D017252:CD3 Complex; D016207:Cytokines; D006683:HLA-DQ Antigens; C053186:HLA-DQ2 antigen; D015804:HLA-DR4 Antigen; D010455:Peptides