Idiotypic analysis of antibodies to poly(Glu60Ala30Tyr10): interstrain and interspecies idiotypic crossreactions

Abstract

A common idiotype was defined by a guinea pig anti-idiotypic antiserum made against D1.LP antibodies specific to the synthetic terpolymer poly(Glu60Ala30Tyr10), referred to as GAT. This idiotype was found in the anti-GAT antibodies of all individuals of all inbred strains of mice tested. Due to its common (C) occurrence in the anti-GAT antibodies of all mouse strains, it was termed the CGAT idiotype. The presence of CGAT idiotype in mice is independent of the expression of various Ig-1, H-2, or Vg genetic markers. In contrast, antibodies produced in response to the crossreactive poly(Glu60-Ala40), termed GA, bound to the GAT ligand but did not bear the CGAT idiotype. This suggests that GAT, although bearing GA determinants, preferentially stimulates clones of CGAT idiotype. Some of the CGAT idiotypic specificities were also identified in sera of WF inbred rats after immunization with GAT. However, no significant levels of CGAT idiotype were detected in LEW rats, F344 rats, guinea pigs, or rabbits, although measurable quantities of anti-GAT antibody were present.