Rectal epithelial gamma/delta T-lymphocyte responses to local gluten challenge in coeliac disease.

The proportion of intra-epithelial lymphocytes (IEL) that utilize the gamma/delta form of the T-cell receptor (TCR) is increased in coeliac disease, but their function remains unexplained. The response of intra-epithelial lymphocytes to rectal gluten challenge in coeliac and control subjects was studied after a rectal challenge of 2 g of Frazer's fraction III. A marked rise in CD3+ IEL occurred after challenge in the coeliac patients, peaking at 6 h and returning to normal by 48 h, with no significant changes in the gamma/delta TCR+ IEL. The IEL did not significantly change after gluten challenge in the controls. Acute gluten challenge induces infiltration of the rectal mucosa by T cells in coeliac patients, which is not accompanied acutely by increased numbers of gamma/delta TCR+ IEL. This study supports the hypothesis that alpha/beta TCR+ T cells may be of importance in the early response of coeliac patients to local gluten challenge.