The monoclonal anti-phosphorylcholine antibody response in several murine strains: Genetic implications of a diverse repertoire*

The idiotypic identification of monoclonal antibodies has been used to define and enumerate clonotypes within the murine repertoire of B cells specific for phosphorylcholine (PC). The response in the BALB/c strain is dominated by a single antibody specificity which is identical to TEPC 15 protein; however, antibody without the TEPC 15 idiotype appears heterogeneous by idiotypic cross-reactivity and hapten inhibition of binding to antigen. Dissection of the PC-specific repertoire in the AKR, A/He, and C3H strains has indicated that some monoclonal antibodies share binding-site idiotypic determinants with TEPC 15, although these clones represent a minority of the precursor cells. In addition to providing insights into the heterogeneity and expression of the murine B-cell repertoire, these studies emphasize structural relationships between PC-specific clonotypes. Within the BALB/c strain, some antibodies share combining-site-related idiotypic specificities with TEPC 15, but differ in other variable region determinants. Among allotypically distinct strains, there exists a remarkable similarity of variable region determinants in at least a minority of antibodies.