Differential Induction and Suppression of Direct and Indidirect PFC Responses to TNP Conjugated to Heterologous Erythrocytes

Abstract

According to the simple receptor model there are strong similarities between the receptor molecules on lymphocytes and the antibodies produced by the cells or their descendents after antigenic stimulation. Mäkelä and others have shown that the monovalent BSA conjugate of NIP (4 hydroxy, 3 iodo, 5-nitrophenyl acetic acid) preferentially induces an IgG anti NIP response, while the polyvalent conjugate preferentially induces an IgM response (1,2,3). This finding is compatible with a simple receptor model, namely, the correspondence between the cell receptor and the antibodies the cell secretes. When Mäkelä and his colleagues conjugated the hapten to sheep red cells (SRC), however, heavily conjugated NNP-SRC (SRC treated with high concentrations of the azide of 3,5-dinitro, 5-hydroxyphenylacetic acid) induced an IgG response, while lightly conjugated NNP-SRC preferentially induced an IgM response. We reported in a previous communication the following contradictory results (4). Mice which were injected with lightly conjugated TNP-SRC (TNP_0.086SRC, or TNP_0.14 SRC, see Material & Methods) induced largely of entirely indirect anti TNP PFC responses. The splenic direct anti TNP PFC response was either absent (to TNP_0.086SRC) or very low (to TNP_0.14SRC).