Activation of caspase-3 in PMNs.

PMNs were cultured as described in Figure 1. Then the cells were fixed, permeabilized, stained with mAb specific for active caspase-3, and analyzed by CLSM. (A) Fresh PMNs showed faint background staining. (B) Overnight-cultured untreated PMNs revealed a bright punctate staining representing active caspase-3. (C) G-CSF strongly inhibited caspase-3 activation. (D) Cells treated with zVAD-fmk did not demonstrate active caspase-3. Bar is 5 μm. Results are representative of at least 3 independent experiments.