Prolamins of maize and wheat differentially affect intestinal cells both in biopsies of celiac patients and CACO-2 cell line

We study the effect of maize zeins on cellular immune response as compared to that of wheat gliadins for exacerbating celiac disease due to a hypothetical similar response in some patients. In vitro activation of celiac duodenal mucosa with gliadin or zein immunoreactive peptides and pro-inflammatory response of CACO-2 cells to digested gliadin or zein fractions were evaluated as indicators of adaptive and innate response, respectively. In 3/5 biopsies, zein increased production of IFN-γ, whereas gliadin has done it in all the patient biopsies. In CACO-2 cells, two zein fractions (3–5 and 1–3 kDa), similar to gliadin fractions, stimulated the production of IL-8, p38 MAPK, COX2, and release of ZO-1 as compared to medium alone. The 3–5 kDa zein fraction increased permeability in cell monolayers, although less than gliadin. Zein peptides are immunogenic for some patients and induce a similar innate response, but to a lesser extent than gliadin peptides.