Perturbations of pHi and the inflammatory milieu alter mechanisms of cell death in phagocytosing neutrophils.
(A) The effects of amiloride (0.2 mM), ZnCl2 (50 μM), bafilomycin (100 nM), and CF ELF (40 μL/mL) on rates of apoptosis at 16 hours in phagocytosing neutrophils (4 replicates from 5 healthy donors) exposed to E coli at a pathogen-to-phagocyte ratio of 20:1. Inhibitors or ELF was added 10 minutes after bacteria. *P < .05; % apoptosis greater than E colialone; **P < .05; % apoptosis less than E coli. Note that bafilomycin did affect apoptosis in neutrophils exposed to lower pathogen-to-phagocyte ratios (see text). (B) The effects of amiloride, ZnCl2, CF ELF, a combination of amiloride plus ZnCl2 plus bafilomycin, and lowering of the extracellular pH on rates of necrosis in the same cells (*P < .005 versus E coli alone).
