VCAM-1 inhibits FAS-induced neutrophil apoptosis. (A) Neutrophils were incubated with 10 μg/mL sVCAM-1, 1000 U/mL IFN-β, or both together in the absence (□) or presence (▪) of 50 ng/mL CD95 antagonist antibody CH-11 for 6 hours and apoptosis measured by DiOC₆ staining. Data are the mean ± SD of 3 separate experiments. (B) Caspase 3 activation was measured in freshly isolated neutrophils (T = 0) or neutrophils incubated for 6 hours in medium alone (□) or presence of 1000 U/mL IFN-β (▪), 10 μg/mL soluble VCAM-1 (▪), or both together (▪) with or without 50 ng/mL of the CD95 activating antibody CH-11. Data are the mean ± SD of 3 separate experiments.