Antigen presentation in celiac disease

Celiac disease is caused by an inappropriate immune response to ingested gluten proteins. As a dietary antigen, gluten undergoes extensive but incomplete proteolytic digestion in the intestinal lumen. The resultant peptide fragments of gluten require deamidation, but not necessarily further intracellular processing for presentation. Recent studies reveal why the disease associated HLA-DQ2 molecule is particularly suited for binding proline-rich gluten peptides. In comparison, DQ8 exhibits different binding characteristics, which may explain the lesser risk for disease in association with this molecule.