Abstract: | IL 2 receptor expression as a function of time after antigenic stimulation was examined on antigen-dependent human CTL clones specific for type A influenza virus. The anti-Tac monoclonal antibody was used to follow IL 2 receptor levels on the cloned cells. Shortly after antigenic stimulation, IL 2 receptor expression was maximal; by 1 wk, however, levels had decayed considerably, and by 2 wk only background expression remained. Reexpression of IL 2 receptors could be induced by exposure of quiescent clones to antigen or lectin. IL 2-driven proliferation of the cytotoxic clones was also examined, and it decayed with the same kinetics as IL 2 receptor levels. Proliferation of quiescent cells could also be obtained by antigen-specific stimulation. Thus, IL 2 receptor expression by human CTL clones at least in part regulates the antigen-specific proliferation of these cells. |