Abstract
Celiac disease is caused by inflammatory, gluten specific T cell responses in the small intestine. Invariably such responses are HLA‐DQ2 or HLA‐DQ8 restricted, providing an explanation for the strong association between celiac disease and these HLA‐class II alleles. It is now clear that some native gluten sequences can bind to HLA‐DQ2/8 and induce T cell responses. In addition, modification of gluten peptides by the enzyme tissue transglutaminase results in high affinity HLA‐DQ2/8 binding peptides that can induce T cell responses. Thus, gluten molecules contain a large number of immunogenic peptides and this is likely to play an important role in the breaking of oral tolerance to gluten. Copyright © 2003 John Wiley & Sons, Ltd.