Figure 3.

Cross-linking of IgGs bound to human neutrophils leads to the secretion of superoxide anions and of lysozyme. Isolated neutrophils were incubated with 10% autologous PPP in the presence or absence of FcγRs blocking antibodies. A: Neutrophils were resuspended at 5x10⁶ cells/ml in HBSS containing 125 μM of cytochrome c and anti-human IgGs antibodies for 10 minutes at 37°C. The reaction was stopped by transfer on ice and the cells were removed by centrifugation. Results are expressed as mean +/− SEM of three independent experiments. * = P < 0.05 (Wilcoxon signed rank test). B: Anti-human IgG antibodies were added for 30 minutes and the neutrophil supernatants were prepared as described in Material and Methods. Lysozyme release and superoxide production were quantified as described in Methods. Results are expressed as mean +/− SEM of three independent experiments. * = P < 0.05 (Mann–Whitney test).