Effect of CR3 and FcγR inhibition on granulocyte oxidative burst. The anti-CD11b-blocking antibody ICRF44 (6.25-50 μg/mL) completely inhibited oxidative burst by N meningitidis H44/76 (2 × 10⁸/mL, 10-minute incubation) (left panel). In contrast, blocking of FcγR using anti-CD16 (FcγRIII), anti-CD32 (FcγRII), and anti-CD64 (FcγRI) (6.25-50 μg/mL) had no effect (right panel). Anti-C5a (clone 137-26) was included in both experiments for comparison. B indicates baseline (unstimulated sample) after a 10-minute incubation (t = 10). Results from 1 of 3 representative experiments are shown.