Regulation of anti-idiotypic antibody on anti-DNA antidody production

Anti-idiotypic antibody(anti-id) regulates antibody(ab) production on B cell. Although regulatory mechanism of anti-id is not fully understood, its effect has been reported only on IgM production. But major pathogenic ab is IgG anti-DNA ab, not IgM anti-DNA ab in systemic lupus erythematosus. Therefore to elucidate the effect of anti-id on IgG anti-DNA ab production, we compared the effect of anti-id on IgM and IgG anti-DNA ab production. Two types of anti-DNA ab producing hybridomas(2 IgM and 2 IgG) which were obtained by fusing spleen cell from MRL/lpr autoimmune prone mice with SP2/0 myeloma cells were treated with anti-id. After treatment with anti-id, amount of IgG production tested by ELISA was decreased (1.0 vs 0.78, p=0.006), but cellular proliferation tested by count of thymidine uptake was not affected (0.89 vs 0.93, p=0.57). In IgM hybridoma, amount of IgM production was decreased (1.0 vs 0.73, p=0.049), but cellular proliferation was not affected (0.81 vs 0.83, p=0.70). Therefore anti-id suppresses ab production without affecting cellular proliferation. This regulatory mechanism maybe not different on IgM and IgG anti-DNA ab production.