Immunization with autologous plus IL-12–secreting allogeneic tumor cells induces Th1 and Th2 immune responses.

Highly purified CD4⁺ T cells from the different experimental groups were evaluated for cytokine release after 5-day in vitro restimulation with irradiated A20 cells. T cells were collected after 4 immunizations. Negligible cytokine production was observed in the presence of irradiated A20 cells alone. Data are given as means (+ SDs) of groups of 3 mice, analyzed individually.