Role of self carriers in the immune response and tolerance. VIII. Suppression of the MOPC-104E idiotypic response by idiotype-modified self, but not by dextran-modified self

We have investigated the suppression of the anti-dextran B1355S immune response using our model of modified self. The anti-dextran response is idiotypically well defined in BALB/c mice. This system enables us to examine the contribution of various predominant idiotypes to the antibody response under conditions of suppression by antigen or by idiotype-specific suppressor cells. Our results demonstrate that the total anti-dextran response can be inhibited by pretreatment of animals with dextran-coupled syngeneic spleen cells; however, the representation of major idiotypes constituting this response are not reduced in percentage. In contrast, pretreatment of mice with MOPC-104E-coupled spleen cells leads to a specific suppression of the private IdI-104E idiotype. The total anti-dextran response remains unchanged, as well as proportions of other major idiotypes known (IdI-588 and IdX). This suppression is mediated by Thy-1.2⁺ T cells, as demonstrated by adoptive transfer assays. This system will allow the molecular dissection of the regulation of an idiotypically well-defined system for the suppression by either antigen- or idiotype-specific suppressor T cells.