Induction and regulation of silent idiotype clones.

In order to study whether allotype linkage of idiotype expression is related to the total absence of structural gene(s) or to regulatory mechanisms acting on its phenotype expression, the M460 clone expression was followed in b cells from various inbred and recombinant strains of mice cultured at low density in the presence of lipopolysaccharide. Under these conditions, all cultures were found to contain anti-trinitrophenyl (TNP) antibody plaque-forming cells, some of which inhibitable by anti-M460 immunoglobulins. In the course of these studies, it also became apparent that, even in the absence of T cells, B lymphocytes are able to exert regulatory functions. Experiments carried out using anti-M460 hybrid cells F6(%!), and affinity-purified anti-(anti-M460) antibodies revealed that clonotype regulation by B cells is mediated by idiotype-auto-antiidiotype interactions.