Concomitant Induction and Persistence of Hapten‐Specific Suppressor and Helper T Cells in Vivo

Intravenous injection of haptenized syngeneic lymphoid cells in the mouse induced a suppression in vivo against any immunogen carrying this hapten, introduced as a second antigen. Suppression was observed against any epitope on such a haptenized immunogen, thus largely excluding cross-reactions at the level of antigen-binding or idiotypy. However, when cells from such suppressed mice were assessed in vitro, it could be shown that significant T-helper activity had been induced by the same procedure, which in vivo resulted in suppression only. Thus, concomitant induction and persistence of hapten-specific suppressor and helper T cells is a result of the present immunization protocol. Both phenomena express the conventional requirements for physical linkage between hapten and immunogen to have an impact on the antibody response against the epitopes of the carrier. It is thus likely that the observed suppression/help in the present system does function at the level of handling the intact immunogen.