Comparative Analysis of Digestibility and Immunogenicity of Gliadin Proteins From Durum and Einkorn Wheat.

Recent studies suggested that gliadin proteins from the ancient diploid einkorn wheat retained a reduced number of immunogenic peptides for celiac disease patients because of a high digestibility with respect to hexaploid common wheat. In this study, we compared the immunological properties of gliadins from two cultivars (Hammurabi and Norberto-ID331) with those of a cultivar (Adamello). Gliadins were digested by mimicking the gastrointestinal digestion process that includes the brush border membrane peptidases. Competitive ELISA, based on R5 monoclonal antibody, showed that gastrointestinal digestion reduced the immunogenicity of gliadins; conversely, the immunogenic potential of gliadins remained almost unchanged by the digestion. The immune stimulatory activity was also evaluated by detecting the IFN-γ production in gliadin-reactive T-cell lines obtained from the small intestinal mucosa of HLA-DQ2+ celiac disease patients. Interestingly, gastrointestinal digestion markedly reduced the capability of gliadins ( <0.05) of both cultivars to activate T cells, while it slightly affected the activity of . In conclusion, our results showed that was almost unaffected by the gastrointestinal digestion, while had a marked sensibility to digestion, thus determining a lower toxicity for celiac disease patients.