Idiotypic analysis of antibodies against the terpolymer L‐glutamic acid60‐L‐alanine30‐L‐tyrosine10 (GAT) IV. Induction of CGAT idiotype following immuniza‐ tion with various synthetic polymers containing glutamic acid and tyrosine

Abstract

The immune responses of all inbred strains of mice specific to the synthetic terpolymer poly(LGlu⁶⁰LAla³⁰LTyr¹⁰), referred to as GAT¹⁰, are characterized by the pres- ence of anti-GAT antibodies which share a common (CGAT) idiotype. In this report, we describe the ability of the synthetic polymers, LGlu³³LAla³³LTyr³³, LGlu⁵¹- LAla³⁴LTyr¹⁵and poly-L(Tyr, Glu)-DLAla–LLys [(T,G)-A–L] to induce antibodies with CGAT idiotypic specificities. All of these polymers contain “GT”-related deter- minants. Following immunization with these polymers, antisera from responder mice bind the corresponding ¹²⁵I-labeled antigen and ¹²⁵I-labeled poly(LGlu⁵⁰LTyr⁵⁰) or GAT¹⁰. These antisera shared the CGAT idiotype which is associated with the anti- body fraction with binding specificity for GAT¹⁰. Collectively, the present results indi- cate that GT-related determinants are required for the induction of the CGAT idio- type. Moreover, since the immune responses to these synthetic polymers are under distinct H-2-linked immune response (Ir) gene control, a mouse strain can be nonre- sponder to one polymer and responder to another; in this case, only the latter polymer induces CGAT idiotype. Thus, although the immune responses of inbred strains of mice to different polymers are under distinct Ir gene control, the antibody responses can be idiotypically related.