The polymerization of actin in response to zymosan. (A) Change in polymerized filamentous (f) actin over time following exposure of neutrophils to zymosan, compared with the time course of phagocytosis. Data shown as mean values from n = 3 healthy donors. (B) Representative histograms illustrating the shift in geometric mean fluorescence before (red) and after (blue) exposure of cells to zymosan, indicating actin polymerization. (C) Change in polymerized f-actin over time in neutrophils treated with vehicle control (■―), rhC5a (▾), or IC87114 followed by rhC5a (▵), then exposed to opsonized zymosan. Data shown as mean and SEM, P < .0001 for difference between treatment groups by 2-way ANOVA, *P < .05 between control and C5a treatment, +P < .05 between C5a + IC87114 and C5a treatment by Bonferroni posthoc test (n = 8 healthy donors).