Presence of highly conserved idiotypic determinants in a family of antibodies that constitute an intrastrain cross-reactive idiotype.

It has been shown that A/J anti-p-azophenylarsonate antibodies that share a major cross-reactive idiotype (CRI) comprise a family of closely related, but nonidentical, molecules. Our results demonstrate that 12 of 14 monoclonal hybridoma products that express the CRI have in common at least one highly conserved idiotypic determinant. It is proposed that this reflects conservation of a portion of the amino acid sequence, presumably in hypervariable regions. That the conserved determinant(s0 are located in the region of the hapten-binding site is indicated by the ability of haptens to inhibit idiotype-anti-idiotype interactions involving the conserved, or public determinants.