Are macrophages the target of antigenic competition between different epitopes of a hapten-carrier conjugate?

The inverse relationship between antibody synthesis and cell-mediated immunity has already been explained by the activities of antibodies and/or regulator lymphocytes. Studying the modulation of the immune response to a hapten-carrier conjugate in the guinea pig, we present experimental data which demonstrate the existence of an antigenic competition between hapten and carrier epitopes for antibody synthesis to the hapten and delayed hypersensitivity reactions to the carrier. This antigenic competition responsible for the inverse relationship between antibody synthesis and cellular immunity appears to occur during the beginning of the immune response at the macrophage level.