A SYNTHETIC PEPTIDE ANALOG OF A DETERMINANT OF TYPE-II COLLAGEN PREVENTS THE ONSET OF COLLAGEN-INDUCED ARTHRITIS

The immunization of genetically susceptible strains of mice with type II collagen (CII) elicits a collagen-induced arthritis that resembles rheumatoid arthritis. Our laboratory previously identified a region of CII, CII-245-270, that contains a T cell epitope that is prominent in the immune response to CII. Residues critical to the I-A(q)-restricte d presentation of this determinant have been characterized. To produce synthetic peptides with the potential of disrupting I-A(q)-restricted Ag presentation, synthetic analogue peptides were developed that cont ain site-directed substitutions in critical positions. One analogue pe ptide was found to be an efficient competitor for binding to I-A(q) an d to be capable of inhibiting T cell responses in vitro. When DBA/1 mi ce were coimmunized with CII and the analogue peptide, the incidence a nd severity of arthritis were greatly reduced, concordant with the hum oral immune responses to CII.