Correlation of phagocytosis-induced neutrophil apoptosis with changes in pHi and intracellular oxidant generation.
Isolated peripheral blood neutrophils were exposed to varying pathogen-to-phagocyte ratios, and early changes in pHi, intracellular oxidant production, and apoptosis were measured after 16 hours. (A) Neutrophil apoptosis is inhibited at lower pathogen-to-phagocyte ratios (*P < .01 by 2-way ANOVA), but is activated at higher ratios (**P < .005 by 2-way ANOVA). (B) Linear correlation between ΔpHi over 90 minutes and Δ% apoptosis at varying pathogen-to-phagocyte ratios. Net ΔpHi is based on a calculation of the phagocytosis-induced change in net pHi curve area above (net alkalinization) and below (net acidification) baseline pHi (baseline pHi curve is that of non–bacteria-exposed neutrophils) over time. (C) Linear correlation between intracellular oxidant generation over 90 minutes and Δ% apoptosis at varying pathogen-to-phagocyte ratios. All data mean ± SEM; r2 indicates coefficient of determination.
