Effect of IFNγ on LPS-induced spleen cell proliferation. Splenocytes from WT (•) or ICE-deficient (○) mice were incubated with 20 μg/mL of LPS in the presence of increasing concentrations of IFNγ. Proliferation was assessed after 72 hours of incubation. Data are the mean ± SEM of 3 mice per group and are expressed as the percentage of change in MTS absorbance over unstimulated cells (100%). *P < .05; **P < .01 versus WT by factorial ANOVA. ^†††P < .001 versus LPS alone by ANOVA for repeated measures.