A component of the nuclear changes that occur during zVAD-sensitized, TNF-α–stimulated neutrophil cell death is apoptosislike.

(A) Neutrophils were preincubated with or without zVAD (100 μM) for 1 hour before the addition of TNF-α (10 ng/mL) at time 0. Genomic DNA harvested from neutrophils incubated with the indicated reagents for 6 hours was then resolved by agarose gel electrophoresis to qualitatively assess internucleosomal DNA fragmentation (see “Materials and methods”). MW indicates 100–base pair (bp) ladder DNA molecular weight standard. (B) In separate experiments, internucleosomal DNA fragmentation was quantitatively determined by assaying for cytoplasmic mononucleosome- and oligonucleosome-associated histone accumulated in membrane-intact cells at the indicated time points (see “Materials and methods”). Results shown represent means ± SEM, n = 3. *P < .05 compared with unstimulated neutrophils at the corresponding times; #P < .05 compared with neutrophils stimulated with TNF-α only at the corresponding times.