Identification of the minimal glycopeptide core recognized by T cells in a model for rheumatoid arthritis

Collagen induced arthritis (CIA) is a common mouse model for rheumatoid arthritis. Two sets of truncated peptides derived from type II collagen have been prepared and tested for binding to A(q), a MHC-II molecule associated with development of CIA. Binding to A(q) correlated well with predictions from a computer-based model. T-cell hybridomas, obtained in CIA, were also used to study the ability of A(q) bound peptides to trigger a T-cell response. The minimal peptide epitope required for binding, as well as for giving a T-cell response, was determined to be CII260-267. In collagen this epitope is often glycosylated at hydroxylysine 264 and glycosylation has been shown to be an immunodominant feature in CIA. Synthesis and evaluation of CII260-267 carrying a beta-D-galactosyl moiety at position 264 revealed that this glycopeptide stimulated representative members from a panel of carbohydrate-specific T-cell hybridomas obtained in CIA.