Figure 2. CD11b^low macrophages engulf higher numbers of apoptotic neutrophils than CD11b^high macrophages.

Sorted CD11b^high and CD11b^low macrophages were stained with Hoechst and LysoTracker, analyzed by confocal microscopy and photographed as indicated (A; merged pictures). Similar preparations were enumerated for apoptotic PMN uptake and analyzed according to average (B) neutrophils engulfed per macrophage (N/M), and percentage of cells reaching engulfment threshold (C) or engulfing the indicated number of apoptotic PMN (D). Results are mean ± SE (B, C) or representative (A, D) from three experiments. Significant differences by Student's t test between CD11b^high and CD11b^low macrophages (* P value< 0.05, ** P value< 0.005, *** P value< 0.001) are indicated.