TNF does not significantly contribute to LPS-induced caspaselike activation. DCs were exposed to LPS (100 ng/mL), with or without pretreatment with zVAD (1 hour, 40 μM) and in the presence of the indicated neutralizing concentrations (2.5-20 μg/mL) of anti-TNF–blocking antibodies. After 16 hours cells were analyzed for PI uptake by flow cytometry. Means ± 1 SD from 3 different experiments are shown.