Modulation of help and suppression in a hapten-carrier system.

Provision of beta-galactosidase (GZ) under defined conditions of dose and time can either help or suppress a subsequent response to trinitrophenyl (TNP)-GZ in CBA/J mice. The optimal helper effect occurs when 10(7) spleen cells from mice primed 9 or more days previously with 10 mug GZ are adoptively transferred to irradiated recipients which are than challenged with 10 mug TNP50GZ. Optimum suppression results from the transfer of spleen cells from mice primed 3 days previously with 100 mug GZ and challenge of recipients with TMP150GZ. Both help and suppression are carrier-specific and mediated by T cells. In experiments where helper or suppressor cells were mixed with normal cells, the anti-TNP response was proportional to the number of primed cells transferred. The results point to a wave of suppression as the initial event after immunization, which is succeeded by period in which the helper effect dominates.