Lysosomal accumulation of gliadin p31-43 peptide induces oxidative stress and tissue transglutaminase-mediated PPARgamma downregulation in intestinal epithelial cells and coeliac mucosa

An unresolved question in coeliac disease is to understand how some toxic gliadin peptides, in particular p31-43, can initiate an innate response and lead to tissue transglutaminase (TG2) upregulation in coeliac intestine and gliadin sensitive epithelial cell lines. Aim We addressed whether the epithelial uptake of p31-43 induces an intracellular pro-oxidative envoronment favouring TG2 activation and leading to the innate immune response.