VCAM-1-mediated rescue shares similar signaling pathways to IFN-β and activates NF-κB. Neutrophils were cultured for 18 hours in the absence (□) or presence of 20 μM PI3K inhibitor LY294002 (▪) with or without 1000 U/mL IFN-β, 10 μg/mL sVCAM-1, or both together (A); in the absence (□) or presence of 100 μg/mL NF-κB inhibitor SN50 (▪) with or without 1000 U/mL IFN-β, 10 μg/mL sVCAM-1, or both together (B); and in the absence (□) or presence of 1 μg/mL cycloheximide (▪) with or without 1000 U/mL IFN-β, 10 μg/mL sVCAM-1, or both together (C). Apoptosis was measured by DiOC6 staining; mean ± SD of 3 separate experiments. (D) NF-κB activation was measured and (E) quantified (see “Materials and methods”) following the exposure of neutrophils to medium alone, 1000 U/mL IFN-β, 10 μg/mL VCAM-1, or both together after 60, 300, and 1800 seconds.