Naive Th cells require exogenous IFN-γ to induce IL-12 production in DC. Naive or memory Th cells were incubated with autologous DC, in the absence or presence of SEA to activate the Th cells and rIFN-γ. Supernatants were procured after 24 hours and levels of IL-12 p70 were analyzed. Result are presented as mean production IL-12 p70 ± SEM of triplicate cultures. Data are representative of three independent experiments.