Long-term suppressor cell lines. I. Demonstration of suppressive function.

Suppressor T cell (Ts) lines have been generated and maintained in culture for over one year. Cells from these lines suppress proliferation by primed lymph node cells and antibody production by primed spleen cells. Ts were originally obtained from either spleens of mice rendered tolerant to human gamma globulin (HGG) or short-term cultures of normal spleen cells. Ts from these two sources have previously been shown to exhibit antigen specificity in that only HGG-specific immune responses were suppressed. Prolonged culture of Ts, however, leads to 2 events: an enrichment for suppressive activity in the cultures; and a polyclonal activation of Ts which is demonstrated by the acquired ability of Ts cell lines to regulate responses to antigens other than HGG. Ts cell lines still contain HGG-specific Ts which can be isolated by their capacity to bind to HGG-coated plates. Only HGG-specific immune responses are suppressed by the HGG-binding Ts.