STUDIES OF IN-VITRO GAMMA-INTERFERON PRODUCTION IN CELIAC-DISEASE AS A RESPONSE TO GLIADIN PEPTIDES

The effects of certain fractions of a peptic-tryptic-pancreatinic (PTP ) digest of wheat gliadin and of synthetic peptides on the production of gamma interferon (gamma-IFN) in cultures of whole blood from adult patients with coeliac disease (CD) have been studied using a sandwich enzyme immunoassay. The most active peptides were fraction 9, its two principal sub-fractions (sub-fractions 1 and 2) and a synthetic peptid e of sequence RPQQPYPQPQPQ (peptide V) corresponding to the principal peptide obtained from reversed-phase HPLC of fraction 9. Results with blood from the control group of subjects also indicated some response to these antigens, in most cases at similar levels to those observed w ith the coeliacs. Fraction 1 of the PTP digest and the other nine synt hetic peptides tested were inactive with both coeliacs and controls. T hese results are in agreement with the results of in vivo and in vitro toxicity tests. They provide evidence of a link between toxicity and cell-mediated immune response in CD, and suggest that peptide V repres ents one of the active parts of the gliadin molecule.