Identification of antibody epitopes in the CB-11 peptide of bovine type II collagen recognized by sera from arthritis-susceptible and -resistant rhesus monkeys.

Sera from eight rhesus monkeys that had been immunized with native bovine type II collagen were tested for antibodies to cyanogen bromide peptides (CB peptides) of type II collagen by Western blotting. The monkeys produced IgG antibodies to a number of different CB peptides, with five out of eight animals producing antibodies to the CB-11 peptide (four arthritic, one non-arthritic). Antibody epitopes on the CB-11 peptide of bovine type II collagen recognized by these sera were investigated by epitope mapping. Peptides (8-mers overlapping by seven amino acids) representing the CB-11 region were synthesised and the sera screened for binding to these peptides to determine areas of high IgG antibody binding to this region of type II collagen. The profiles obtained were not identical, though there were some epitopes that were commonly recognized. Antibodies to one epitope, also present in human type II collagen, were found only in the sera of two animals with the severest arthritis. The technique of epitope mapping has successfully identified a number of epitopes within the CB-11 peptide of type II collagen recognized by antibodies from bovine type II collagen-immunized monkeys. Studies on the relevance of responses to the identified epitopes can now be undertaken.