Figure 3.

CD13-mediated phagocytosis requires actin reorganization and Syk and PIK3 activities. Neutrophils were incubated with 10 µg Fab fragments of mAb452 or mAb C (anti-CD13), with 10 µg of mAb G8 (anti-FcγRIIIb), or without antibody (no Fab) for 30 minutes at 4°C. After washing, cells were incubated with 5 µM cytochalasin D, 10 µM BAY, or 20 µM LY294002, or DMSO as vehicle control for 20 min at 37°C. Then, cells were incubated for 1 hour at 37°C with EBS-Fab. Non ingested erythrocytes were lysed and samples were analyzed by flow cytometry to determine the percentages of CFSE-positive cells. The bars show the mean ± SEM of CFSE-positive cells from 5 independent experiments for cytochalasin D, and from 11 experiments for the pharmacological inhibitors of kinases (BAY and LY294002). *p<0.05, **p<0.01, ***p<0.001.