Autoreactivity in collagen-induced arthritis of rats: a potential role for T cell responses to self MHC peptides

Collagen-induced arthritis (CIA) is a chronic inflammatory arthropathy of rats which follows immunization with bovine type II collagen (bCII). T cell lines generated from arthritic rats have been shown to be self-reactive and proliferate in an autologous MLR, which is MHC-dependent. However, the peptides which drive this autoreactive response remain to be elucidated. T cell lines, generated initially to bCII, were cultured with synthetic peptides representing potential autoreactive self epitopes. C1q-c(50-64) peptide, which demonstrates sequence homology to the bCII(184-198) peptide, failed to stimulate T cell proliferation suggesting that the autologous MLR was not due to antigen cross-reactivity with this self peptide. In contrast, several peptides from the amino-terminal region of the RT1D(alpha) MHC class II molecule stimulated proliferative responses. These results suggest that immunization with bCII leads to activation of a population of autoreactive T cells which respond in an autologous MLR, and that this response could be due, in part, to T cell reactivity to self MHC peptides. (C) 2002 Published by Elsevier Science Ltd.