Gluten-Free Diet Induces Rapid Changes in Phenotype and Survival Properties of Gluten-Specific T Cells in Celiac Disease

Abstract

Background and AimsThe treatment of celiac disease (CeD) with gluten-free diet (GFD) normalizes gut inflammation and disease-specific antibodies. CeD patients have HLA-restricted, gluten-specific T cells persisting in the blood and gut even after decades of GFD, which are re-activated and disease driving upon gluten exposure. Our aim was to examine the transition of activated gluten-specific T cells into a pool of persisting memory T cells concurrent with normalization of clinically relevant biomarkers during the first year of treatment. MethodsWe followed 17 CeD patients during their initial GFD year, leading to disease remission. We assessed activation and frequency of gluten-specific CD4+ blood and gut T cells with HLA-DQ2.5:gluten tetramers and flow cytometry, disease-specific serology, histology and symptom scores. We assessed gluten-specific blood T cells within the first three weeks of GFD in six patients and serology in additional nine patients. ResultsGluten-specific CD4+ T cells peaked in blood at day 14 while upregulating Bcl-2 and downregulating Ki-67, then decreased in frequency within 10 weeks of GFD. CD38, ICOS, HLA-DR and Ki-67 decreased in gluten-specific cells within three days. PD-1, CD39 and OX40 expression persisted even after 12 months. IgA-TG2 decreased significantly within four weeks. ConclusionGFD induces rapid changes in phenotype and number of gluten-specific CD4+ blood T cells, including a peak of non-proliferating, non-apoptotic cells at day 14. Subsequent alterations in T-cell phenotype associate with the quiescent but chronic nature of treated CeD. The rapid changes affecting gluten-specific T cells and disease-specific antibodies offer opportunities for clinical trials aiming at developing non-dietary treatments for newly diagnosed CeD patients.