Single Chain Recombinant HLA-DQ2.5/peptide Molecules Block α2-gliadin-Specific Pathogenic CD4(+) T Cell Proliferation and Attenuate Production of Inflammatory Cytokines: A Potential Therapy for Celiac Disease

Celiac disease (CD) is a disorder of the small intestine caused by intolerance to wheat gluten and related proteins in barley and rye. CD4(+) T cells play a central role in CD, recognizing and binding complexes of HLA-DQ2.5 bearing gluten peptides that have survived digestion and that are deamidated by tissue transglutaminase (TG2), propagating a cascade of inflammatory processes that damage and eventually destroy the villous tissue structures of the small intestine. Here we present data showing that recombinant DQ2.5-derived molecules bearing covalently tethered α2-gliadin-61-71 peptide have a remarkable ability to block antigen-specific T cell proliferation and inhibited pro-inflammatory cytokine secretion in human DQ2.5-restricted α2-gliadin specific T cell clones obtained from patients with celiac disease. The results from our in vitro studies suggest that HLA-DQ2.5 derived molecules could significantly inhibit and perhaps reverse the intestinal pathology caused by T cell mediated inflammation and the associated production of proinflammatory cytokines.