Murine monoclonal anti-DNA antibodies with an absolute specificity for DNA have a large amount of idiotypic diversity.

The clonal heterogeneity of nine monoclonal antibodies with absolute specificities for deoxyribonucleic acid (DNA) was analyzed. These monoclonal anti-DNA antibodies were generated in three different fusion experiments using autoimmune (NZB X NZW)F1 mouse spleen cells. Isoelectric focusing analyses demonstrated different isoelectric points within the IgG2a and IgG2b subclasses. Three anti-idiotypic antisera were prepared (one in a rabbit and two in mice) against two monoclonal anti-DNA antibodies. These antisera detected idiotypic determinants uniquely associated with homologous hybridoma anti-DNA antibodies. Two of these idiotypes could be detected at low levels in the sera of (NZB X NZW)F1 mice. Anti-PME77 idiotypic antiserum had no effect in vitro on the total binding capacity of (NZB X NZW)F1 sera. Taken together these results demonstrate that, in (NZB X NZW)F1 mice, the anti-DNA antibody repertoire contains molecules that show similar antigen binding characteristics but are not structurally uniform.