Summary
PROJECT SUMMARY/ABSTRACT Significant data implicate a role for autoantibodies to citrullinated proteins in RA pathogenesis, and autoantibodies to the citrullinating enzyme peptidylarginine deiminase 4 (PAD4) are also found in a subset of patients with the most severe joint disease. Citrullination is the calcium-dependent conversion of peptidyl- arginine to citrulline by the PAD enzymes, but the mechanisms that initiate immune responses to citrullination- associated autoantigens are poorly understood. While different several mechanisms have been proposed, our published and preliminary data impl