Effects of cytokine inhibition on IFNγ production in response to wt Lm infected BMDC. Control IgG, anti-IL-12 and anti-TNFα were used at 10ug, and the caspase inhibitor ZVAD-FMK and control FA-FMK were used at 10μM. Inhibition of IL-12, TNFα, and caspases reduced the level of IFNγ produced in response to wt Lm infected BMDC, indicating that each of these cytokines is necessary, but not sufficient for activationof naïve NK cells.