Death of PMNs.

(A-B) PMNs were cultured for 6 hours without additions, with 20 ng/mL TNF-α, with 150 μM zVAD-fmk, or with the combination of these agents, and cell death was assessed (A) by FACScan analysis of annexin-V–FITC/PI staining and (B) by morphologic examination of cytospins stained with May-Grünwald-Giemsa stain (for quantitative data see C). Arrowheads indicate PMNs that have undergone spontaneous or TNF-α–induced apoptosis with typical apoptotic morphology; closed and open arrows depict PMNs with aberrant morphology appeared after TNF-α/zVAD-fmk treatment (see “Results” for details). (C) Quantitative data obtained by FACScan analysis and cytospin evaluation of PMNs treated for 6 hours under the conditions as indicated. Dosage of additions: TNF-α and zVAD-fmk, as indicated for A and B; anti-Fas monoclonal Abs, 500 ng/mL. *P < .05. Data represent means ± SEM of 4 to 8 separate experiments performed in duplicate.