Effects of gliadin-derived peptides from bread and durum wheats on in vitro cultures of human cell lines. Implications for coeliac disease pathogenesis.

A peptic-tryptic-cotazym digest, obtained from bread (hexaploid) wheat gliadins under experimental conditions mimicking in vivo protein digestion, was found to reduce in vitro viability of human embryo (MRC-5) and tumor cell (Hep-2) lines. Time of onset and extent of cytotoxic effects were largely dependent on initial peptide concentrations in the culture medium. The presence of 2% fetal calf serum was capable of delaying, but not of preventing, the onset of cytotoxic effects only in MRC-5 cultures. A peptic-tryptic-cotazim digest obtained from durum (tetraploid) wheat gliadins and tested under identical conditions did not show any cytotoxic activity on MRC-5 and Hep-2 cell lines. These results indicate that cell systems are useful to investigate pathogenetic mechanisms of coeliac disease (gluten-dependent enteropathy).