Binding of gliadin to lymphoblastoid, myeloid and epithelial cell lines

The aim of our work was to investigate the in vitro reactivity of gliadin peptides of natural and synthetic origin with various cell lines. We have found that all tested cell lines of human, mouse and rat origin were agglutinated by enzymically digested gliadin (peptic-tryptic- and peptic-tryptic pancreatic digest of alpha-gliadin) in a concentration dependent manner. In order to test the specificity of binding, inhibition studies were performed using a panel of sugars as well as natural and synthetic peptides derived from gliadin. We have found that among twelve tested sugars only fetuin and phosphomannan were able to inhibit the agglutination of K562 cells with peptic-tryptic- but not with peptic-tryptic pancreatic digest of alpha-gliadin. The lack of inhibition by gliadin peptides and most of the saccharides suggests that agglutinating activity of gliadin is the result of a nonspecific binding of gliadin to the cell membrane.