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

Luigia Di Stasio; Stefania Picascia; Renata Auricchio; Serena Vitale; Laura Gazza; Gianluca Picariello; Carmen Gianfrani; Gianfranco Mamone

doi:10.3389/fnut.2020.00056

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

Front Nutr. 2020 May 22:7:56. doi: 10.3389/fnut.2020.00056. eCollection 2020.

Authors

Luigia Di Stasio¹, Stefania Picascia², Renata Auricchio³, Serena Vitale², Laura Gazza⁴, Gianluca Picariello¹, Carmen Gianfrani², Gianfranco Mamone¹

Affiliations

¹ Institute of Food Sciences, National Research Council, Avellino, Italy.
² Institute of Biochemistry and Cell Biology, National Research Council, Naples, Italy.
³ Department of Translational Medical Science, Section of Paediatrics, European Laboratory for the Investigation of Food-Induced Diseases, University "Federico II", Naples, Italy.
⁴ CREA-Research Centre for Engineering and Agro-Food Processing, Rome, Italy.

Abstract

Recent studies suggested that gliadin proteins from the ancient diploid einkorn wheat Triticum monococcum retained a reduced number of immunogenic peptides for celiac disease patients because of a high in vitro digestibility with respect to hexaploid common wheat. In this study, we compared the immunological properties of gliadins from two Triticum monococcum cultivars (Hammurabi and Norberto-ID331) with those of a Triticum durum cultivar (Adamello). Gliadins were digested by mimicking the in vitro 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 Triticum monococcum gliadins; conversely, the immunogenic potential of Triticum durum gliadins remained almost unchanged by the in vitro 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 Triticum monococcum gliadins (p <0.05) of both cultivars to activate T cells, while it slightly affected the activity of Triticum durum. In conclusion, our results showed that Triticum durum was almost unaffected by the in vitro gastrointestinal digestion, while Triticum monococcum had a marked sensibility to digestion, thus determining a lower toxicity for celiac disease patients.

Keywords: T-cell assay; Triticum durum; Triticum monococcum; brush border membrane; enzyme-linked immunosorbent assay (ELISA); gluten proteins; in vitro enzymatic digestion.