T cells in peripheral blood after gluten challenge in coeliac disease

• Published in: Gut 2005-09, Vol.54 (9), p.1217-1223
• Main Authors: Anderson, R P, van Heel, D A, Tye-Din, J A, Barnardo, M, Salio, M, Jewell, D P, Hill, A V S
• Format: Article
• Language: English
• Subjects: Adult; Aged; antigen challenge; Antigens; Biological and medical sciences; Case-Control Studies; Celiac disease; Celiac Disease - immunology; Cloning; coeliac disease; Councils; Cytokines; ELISPOT; EMA; endomysial antibodies; Enzyme-Linked Immunosorbent Assay - methods; Epitopes, T-Lymphocyte; Female; Gastroenterology. Liver. Pancreas. Abdomen; GFD; Gliadin - immunology; Gluten; gluten free diet; Glutens; HLA-DQ Antigens - analysis; Hospitals; Humans; IFN-γ; Immunity, Cellular; Immunophenotyping; Integrins - analysis; interferon γ; Interferon-gamma - immunology; interleukin; Intestinal Mucosa - immunology; Lymphocyte Activation; Lymphocytes; Male; Medical sciences; Middle Aged; Other diseases. Semiology; PBMC; Peptide Fragments; Peptides; peripheral blood mononuclear cells; PPD; purified protein derivative of Mycobacterium bovis; Sensitivity and Specificity; SFU; Small Intestine; spot forming units; Statistics, Nonparametric; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Studies; T cell epitopes; T cell receptors; T-Lymphocytes - immunology; tissue transglutaminase; tTG
• ISSN: 0017-5749; 1468-3288; 1458-3288
• DOI: 10.1136/gut.2004.059998

Background: Current understanding of T cell epitopes in coeliac disease (CD) largely derives from intestinal T cell clones in vitro. T cell clones allow identification of gluten peptides that stimulate T cells but do not quantify their contribution to the overall gluten specific T cell response in individuals with CD when exposed to gluten in vivo. Aims: To determine the contribution of a putative dominant T cell epitope to the overall gliadin T cell response in HLA-DQ2 CD in vivo. Patients: HLA-DQ2+ individuals with CD and healthy controls. Methods: Subjects consumed 20 g of gluten daily for three days. Interferon γ (IFN-γ) ELISPOT was performed using peripheral blood mononuclear cells (PBMC) to enumerate and characterise peptide and gliadin specific T cells before and after gluten challenge. Results: In 50/59 CD subjects, irrespective of homo- or heterozygosity for HLA-DQ2, IFN-γ ELISPOT responses for an optimal concentration of A-gliadin 57–73 Q-E65 were between 10 and 1500 per million PBMC, equivalent to a median 51% of the response for a “near optimal” concentration of deamidated gliadin. Whole deamidated gliadin and gliadin epitope specific T cells induced in peripheral blood expressed an intestinal homing integrin (α4β7) and were HLA-DQ2 restricted. Peripheral blood T cells specific for A-gliadin 57–73 Q-E65 are rare in untreated CD but can be predictably induced two weeks after gluten exclusion. Conclusion: In vivo gluten challenge is a simple safe method that allows relevant T cells to be analysed and quantified in peripheral blood by ELISPOT, and should permit comprehensive high throughput mapping of gluten T cell epitopes in large numbers of individuals with CD.