Generation of monoclonal rheumatoid factors after immunization with collagen II-anti-collagen II immune complexes. An anti-idiotypic antibody to anti-collagen II is also a rheumatoid factor.

Two monoclonal IgG rheumatoid factors were obtained after hybridization of spleen cells from DBA/1 mice immunized with immune complexes containing native collagen type II and a monoclonal anti-collagen II antibody. One of these rheumatoid factors reacted not only with purified murine Fc fragments, but also with Fab fragments of the anti-collagen II antibody used for immunization, whereas no reactivity was seen with Fab fragments from normal mouse IgG. The findings demonstrate the ability of immune complexes encompassing native collagen type II to induce production of IgG rheumatoid factors, and suggest that an idiotypic relationship may exist between certain rheumatoid factors and anti-collagen II antibodies.