Inheritance of antibody specificity. IV. Control of related molecular species by one VH gene.

Products of two unrelated VH genes or gene clusters of the mouse, VHABA-HOPb and VHNPb, were studied by submitting antisera of immunized mice (either ABA-HOP-immunized or NP-immunized) to an IEF analysis and fine-specificity tests (affinities for a series of structural analogs). Products of both genes had an exotic (heteroclitic) fine-specificity. The products of both genes included several molecular species detectable by IEF (spectrotypes). Some of them were shared by many immunized mice (shared spectrotypes), but others occurred only in one mouse of several tested. Fine-specificity of two shared spectrotypes of the VHNPb gene, N-1 and N-4, were determined. Both were heteroclitic but they differed in nuances of the fine-specificity. Occurrence of different spectrotypes in the course of an NP immunization had a regular pattern. In the primary response, we could detect at least four shared spectrotypes (N-1, N-2, N-3, and N-4). They were predominant in the early response (days 8-14) but less so on day 30. In the secondary response, shared spectrotypes were in the minority, and, in the tertiary response, they had been fully replaced by individual spectrotypes which had a higher affinity for NP than the shared spectrotypes.