Exogenous TNF-α restores the susceptibility of splenic CFU-C from NK cell–deficient

RAG2-γ_c^−/−mice to Fas cross-linking. Spleen cells were incubated for 24 hours in culture medium alone, TNF-α (10 ng/mL), or anti-Fas mAb (5 μg/mL) combined with IFN-γ (100 U/mL), TNF-α, or both. Cells were then recovered and evaluated for colony growth in methylcellulose. Data are means ± SEM from triplicate determinations.