The role of suppression in immunoregulation: in vivo analysis using a monoclonal antibody to T suppressor factors.

Abstract

We have used a monoclonal antibody (mAb)-specific for murine T suppressor (Ts) cells (mAb 14-12) to study the role of T cells in tolerance and immunoregulation. We demonstrate that mAb 14-12 can block in vivo Ts cell activity in a variety of experimental systems. It prevents the induction of Ts cells induced by i.v. injection of the water-soluble hapten 2,4,6-trinitrobenzene sulfonic acid, and the protein antigen bovine serum albumin. When 14-12 mAb is given prior to the i.v. injection of trinitrophenyl-conjugated spleen cells (TNP-SC) it blocks the induction of Ts cells and sufficiently overcomes suppression so that TNP-SC is able to induce immunity. mAb 14-12 can convert nonresponder mice into responders for the Ir gene-controlled response to the random terpolymer L-glutamic acid60-L-alanine30-L-tyrosine 10 (GAT), and can substitute for cyclophosphamide in overcoming a suppressor barrier in the adoptive transfer of contact sensitivity. Administration of 14-12 mAb just prior to immunization results in the augmentation of contact sensitivity, antibody and plaque-forming cell responses. These results demonstrate the versatility of this reagent for the study of Ts cell activity.