CTL activated by 3/28 beads in the presence of IL-12 or IL-4 secrete type 1 or type 2 cytokines, respectively. Splenic T cells were expanded by CD3, CD28 stimulation under T1- or T2-promoting conditions. Resultant CD4/CD8 cells (Th1/Tc1 or Th2/Tc2) or purified CD8 cells (Tc1 or Tc2) were restimulated with 3/28 beads on day 4 of culture; the resultant supernatant was tested by ELISA for cytokine content. Results represent mean and standard error of the mean (SEM) of 3 independent experiments.