FIGURE 5.

Macrophage efferocytosis of apoptotic cells. Peritoneal macrophages from wild type C57BL/6 mice were fluorescently labeled with CFDA-SE and then made apoptotic by incubation with staurosporine in serum-free medium overnight. The fluorescently labeled apoptotic cells (1 × 10⁶) were then added to freshly plated APOE3 and APOE4 macrophages in 24-well dishes for a 2-h incubation period. The phagocytes were fixed, and efferocytosis efficiency based on uptake of fluorescently labeled apoptotic cells by APOE3 (open tracings) and APOE4 (shaded tracings) macrophages was assessed by flow cytometry, using cells with or without fluorescent labels as positive and negative markers for gating purposes as indicated. A shows representative results from one experiment, and B shows data collected from four experiments ± S.E. * denotes difference from APOE3 macrophages at p < 0.01.