a-Gliadin (229-246) – Other Categories

a-Gliadin (229-246) is derived from Gliadin peptides, the component of wheat involved in the gastrointestinal symptoms of wheat allergy and Celiac Disease (CD). During wheat allergies histamines and leukotrienes are secreted due to gliadin peptide sequences cross-linking two IgE molecules on mast cells and basophils. The glutamine and proline rich peptides of which Gliadin is composed of are resistant to proteolysis during digestion, leaving them active in the gastrointestinal tract. Subsequently these are deamidated by tissue transglutaminase and can bind to HLA-DQ2 or DQ8. As a result in patients with the autoimmune disease CD, there is a Th1-mediated inflammatory immune response against these gliadin peptides. Gliadin can exert additional effects on the intestinal microbiota and ileal barrier function. It has been found that gut microbiota members such as Bifidobacterium and lactobacillus have the ability to digest and inactivate gliadin peptides hence reducing their inflammatory effects in the gastrointestinal system.