Regulation of the BALB/c anti-p-azophenylarsonate antibody response by monoclonal anti-idiotype. II. Idiotope expression in serum and its regulation.

Five murine monoclonal antibody (mAb) anti-idiotypes (id), shown in the accompanying report by binding studies to be reactive with five different id on a single member of the 5AF6 family of BALB/c antibodies against the p-azophenylarsonate (Ar) hapten, were used to examine the distribution of their recognized id among anti-Ar in BALB/c and other mouse strains immunized with keyhole limpet hemocyanin-Ar (KLH-Ar). Differences in id expression in BALB/c and other strains substantiate that all five monoclonal anti-id reacted with different id. This suggests that the anti-id repertoire for a single antibody molecule may be extensive. Two of the anti-id reacted with id that were found in virtually all KLH-Ar immunized BALB/c mice, but constituted only a subset (approximately 33%) of the antibodies representing the 5AF6 family. The other three anti-id reacted with id infrequently expressed among BALB/c anti-Ar. Other mouse strains producing 5AF6 family anti-Ar antibodies also produced antibodies recognized by mAb 2CB8 and 6BA1; however, the three id infrequently expressed in BALB/c mice were produced in higher quantities and in a greater percent of mice. Monoclonal anti-id were capable of suppressing a portion but not all of the 5AF6 family of anti-Ar antibodies. Four of the five anti-id suppressed a greater fraction of the 5AF6 family than that id represented in a normal immune response, suggesting that suppression was mediated via an id other than that recognized by these monoclonal anti-id. Overall, the results indicate that an extensive repertoire of anti-id can be produced against a single id antibody, but suppression induced by treatment with these anti-id in this model is presumably mediated via another as yet unidentified id determinant(s).