GLIADIN-SPECIFIC T-CELL RESPONSES IN PERIPHERAL-BLOOD OF HEALTHY-INDIVIDUALS INVOLVE T-CELLS RESTRICTED BY THE CELIAC-DISEASE ASSOCIATED DQ2 HETERODIMER

Coeliac disease (CD) is probably caused by an abnormal immune response towards wheat gliadin in the small intestine. We found that gliadin-s pecific T cells from the small intestinal mucosa of HLA-DQ2 positive C D patients were almost exclusively restricted by the disease-associate d DQ2 molecule. In the peripheral blood of CD patients, a large propor tion of gliadin-specific T cells were found to be restricted by DQ mol ecules, including DQ2, but many were instead restricted by DR or DP mo lecules of the patient. We have now investigated gliadin-specific T ce ll responses in peripheral blood from healthy individuals. Four of 20 persons tested had strong in vitro responses and were used as donors f or gliadin-specific T cell clones. We found gliadin-specific T cells r estricted by the CD-associated DQ2 molecule in peripheral blood for tw o of these four individuals. It is the presence of such T cells also i n the small intestinal mucosa which seems typical of CD.