Genetic control of the immune response to the L-Glu60-L-Ala30-L-Tyr10 (GAT) terpolymer. V. Three types of idiotypic specificities on BALB/c anti-GAT antibodies.

Three types of idiotypic specificities compose the major idiotype of anti-poly (L-Glu60-L-Ala30-L-Tyr10) (GAT) antibodies from BALB/c mice (idiotype termed GAT-715). Assays have been designed to analyzed and study the distribution of these specificities. The highly conserved idiotypic specificity (h.c.GAT) has been assayed by the binding of serum 715-7A4 to radiolabeled rat anti-GAT antibodies. Guinea pig and mouse anti-GAT antisera all express the same h.c.GAT specificity. The public specificity (p.GAT) has been shown to be present in an identical form in all anti-GAT antisera from all strains of mice studied. The assay used for p.GAT was the binding of serum 715-7A4 to C57BL/6 anti-GAT antibodies that express only p.GAT. Finally, the strain-restricted specificity s.r.GAT has also been investigated by radioimmunoassay; this specificity is expressed only by strains BALB/c, BALB/b, BUB/J, DBA/2, DBA/1 and ATL. This expression is independent of known allotypic markers. However, the expression of the s.r.GAT specificity of BALB/c mice follows the genetic distribution of VH genes of BALB/c origin indicating that s.r.GAT can be considered as a genetic marker of some VH gene(s) involved in the specific immune response to the GAT terpolymer.