IDIOTYPIC ANALYSIS OF ANTI-GAT ANTIBODIES .3. DETERMINANT SPECIFICITY AND IMMUNOGLOBULIN CLASS DISTRIBUTION OF CGAT IDIOTYPE

Abstract

The humoral response to poly-(L-glutamic acid60, L-alanine30, L-tyrosine10) (GAT), in mice is further characterized by idiotype and fine specificity analyses. The common idiotype on murine anti-GAT antibodies [Ab] (CGAT) was identified in anti-GAT antisera from 7 additional strains of mice. The CGAT idiotype can be induced in all inbred strains of mice. Using a partially inbred strain of mice selected for their ability to respond to poly-(L-glutamic acid50, L-tyrosine50) (GT), the GT copolymer is capable of inducing Ab that express the CGAT idiotype. Antisera directed against poly-(L-glutamic acid60, L-alanine40) (GA), bind GAT but lack CGAT idiotype. GAT molecules contain determinants similar or identical to those on GT molecules, which are responsible for the induction of CGAT idiotypic Ab. GAT responder and nonresponder strains of mice can produce anti-GAT Ab with similar fine specificity patterns and CGAT idiotype. Ig[immunoglobulin]M, IgG1 and IgG2 Ab express the CGAT idiotype.