Histocompatibility antigens and genetic control of the immune response in guinea pigs. III. Specific inhibition of antigen-induced lymphocyte proliferation by strain-specific anti-idiotypic antibodies.

The in vitro T-cell proliferation induced by penicilloylated bovine IgG (BPO-BGG) in sensitized strain 2 and strain 13 guinea pigs could be specifically blocked by strain-specific antisera presumably directed against cell membrane-associated immunoglobulin idiotypes. The anti-idiotypic antisera were prepared in strain 2 and strain 13 guinea pigs against immunoadsorbent purified anti-BPO-BGG antibodies which had been raised in strain 2 and strain 13 animals. Strain 13 antistrain 13 anti-BPO-BGG (a strain 13 BPO-BGG) suppressed the in vitro BPO-BGG response of cells from immunized strain 13 animals but did not inhibit the response of cells from immune strain 2 animals. Conversely, the corresponding antiserum raised in a strain 2 combination (a strain 2 BPO-BGG) only inhibited the in vitro BPO-BGG response of strain 2 cells. Furthermore, the inhibitory activity of the antisera could only be absorbed by immune cells from the syngeneic strain. The activity of the a strain 13 BPO-BGG serum was highly specific; the inhibitory activity could only be absorbed by BPO-BGG-sensitive strain 13 cells. The inhibitory activity of the anti-idiotypic sera was predominantly associated with the 19S fraction. The data suggest that immune cells and in particular T lymphocytes from strain 2 and strain 13 guinea pigs possess strain-specific recognition structures from BPO-BGG with the same idiotypes as the corresponding strain-specific immunoglobulins. Furthermore, the production of such inhibitory anti-idiotypic sera was restricted to syngeneic combinations, which suggests a potential role of autoanti-idiotypic antibodies in the regulation of the immune response. The anti-idiotypic antisera used here are apparently directed against gene products not associated with the strain 2 or strain 13 major histocompatibility complex.