Induction of primary and inhibition of secondary antibody response to hapten by hapten conjugates of type III pneumococcal polysaccharide.

Trior dinitrophenylated pneumococcal polysaccharide type 111 ( T N P or DNPS I I I ) ) induced a primary 19s anti-TNP response without generating immunological niemory to the hapten in LAFI mice. Hapten-hemocyanin (TNP-KLH) or hapten conjugates of B . a6ortirs organisms (DNP-BA) induced both 19s and 7s primary responses and memory to the hapten. Spleen cells from mice immunized with T N P K L H or DNP-BA did not give adoptive memory responses upon challenge with hapten-SI11 and, in fact, were inhibited from responding to their homologous hapten conjugates by simultaneous injection of hapten-SIII. Incubation of TNP-KLHprimed spleen cells for as short as 5 min a t 0°C with 10 pg of TNP-SI11 per milliliter virtually abolished their ability to give 19s and 7s memory responses to TNP-KLH upon transfer into irradiated recipients. It is suggested that a difference in avidity and/or number of anti-TNP receptors per cell between virgin and primed B cells may be an important factor in determining whether the cells will be stimulated or inhibited by exposure to hapten-SIII. Another factor may be a difference between virgin and memory cells in their requirement for T-cell help.