The effect of in vivo rhIFN-γ on bacterial ingestion by neutrophils. These graphs show the mean ± SE phagocytosis by neutrophils of S aureus-BODIPY BioParticles opsonized with complement-depleted serum (A; •; n = 6) or pooled human serum with intact complement (B; ○; n = 4). Phagocytosis by neutrophils from rhIFN-γ–treated subjects was calculated as MFI (subject)/MFI (control) × 100. Asterisks indicate statistical significance (P < .05).