Repertoire of the anti-MOPC 173 anti-idiotypic antibodies: Genetical and structural features

Abstract

Anti-idiotypic antibodies against the MOPC 173 protein (IgG2a,κ) were raised in five strains of mice. Three types of responses were observed: CBA and A/J mice were all high-responder (HR) as appreciated from the haemagglutinating titers. Balb/B animals were very low or non-responders (NR). Individual antisera titers of Balb/c and C57BL/6 mice were scattered, ranging from no response to high titers. CBA and A/J antibodies (HR) gave an IEF pattern that was characteristic of each strain, which is suggestive of the expression of germ-line genes. By contrast, discrete IEF patterns of Balb/c and C57BL/6 were observed for each antiserum tested, a situation which might be compatible with either the expression of a somatic repertoire or an extremely large collection of heterogeneous germ-line V genes. Cross-reactive idiotypes were looked for by screening a collection of 115 mouse myeloma sera. Only 2 were found to be slightly inhibitory in a specific radioimmunoassay. A segregation of the NR and HR characters was observed within our Balb/c colony, which is suggestive that some level of genetic drift had taken place. Genetical characteristic of HR and NR strains, screened for the H-2 locus and the C H allotypes, suggest that the expression of these anti-idiotypic antibodies depends both on the Ig gene repertoire and on regulation mechanisms that might be encoded by the I region genes.