Binding of autoreactive mouse anti-type II collagen antibodies derived from the primary and the secondary immune response investigated with the biosensor technique

The reactivity of autoantibodies to type II collagen, secreted by B cells isolated from the primary and the secondary immune response to rat type II collagen in DBA/1 mice, was investigated using BIAcore 2000 instrumentation. Assays were performed on both collagen and antibody surfaces. These assays demonstrated a 100-fold difference in affinity between primary and secondary immune response antibodies. The difference in affinity was almost entirely due to differences in the dissociation rate constant. Somatic mutations in secondary clones were in one case associated with a 3-4-fold difference in affinity and in another case appeared to be without any effect on the binding activity.