Genetic Control of Specific Immune Suppression

In earlier studies from our laboratory, mice that are nonresponders (H2P, H29, H-28) to the terpolymer of L-glutamic acids°-L-alanine3°-L-tyrosine'° (GAT)' were shown to develop suppressor T cells capable of inhibiting GAT-specific responses to GAT complexed with methylated bovine serum albumin (GATMBSA) (1). This finding raised several important points: (a) Could suppressor T cells be demonstrated in nonresponder mice immunized with antigens other than GAT? (b) Do all nonresponder strains unable to form an antibody response to an antigen under H-2-linked Ir gene control develop suppressor cells? (c) If the ability to generate suppressor cells in response to an antigen is observed in some mouse strains but not in others, are these phenotypic differences under genetic control? (d) If such genetic control is observed, are the responsible genes linked to the major histocompatibility complex of the mousein a manner similar to what has been demonstrated for the control of antibody responses by H-2linked Ir genes (2, 3)? We have selected the copolymer of L-glutamic acids° and L-tyrossnns° (GT) to investigate these points for the following reasons. Firstly, it was reported that GT fails to induce antibody responses in any of the inbred strains of mice tested, although it is immunogenic in some individual random-bred Swiss mice (4), in strain 13 guinea pigs (5), and in some inbred rat strains (6) . Secondly, the copolymer GT can be complexed readily with positively charged MBSA and, as will be shown, GT-MBSA is immunogenic for mice unable to form antibody responses to GT. Thirdly, we could use the same technique that was used