Neutrophil-DC hybrids retain functionality as professional phagocytes. (A) Cells harvested from GM-CSF–supplemented BM culture (d 6) were incubated for 30 min at 4°C or 37°C with FITC-DX, live E. coli expressing GFP, or fluorescent beads and then examined for the mean fluorescence intensity (MFI) or percent bead⁺ cells within the Ly6G⁺/CD11c⁻ neutrophil, Ly6G⁺/CD11c⁺ hybrid, and Ly6G⁻/CD11c⁺ traditional DC populations. Some samples were tested after a 2-h pretreatment with PMA (100 nM). (B-D) Ly6G⁺/CD11c⁻/MHC II⁻ neutrophils, Ly6G⁺/CD11c⁺/MHC II⁺ neutrophil-DC hybrids, and Ly6G⁻/CD11c⁺/MHC II⁺ traditional DCs purified from GM-CSF–supplemented BM culture (d 6) were examined for NET formation. The purified samples were incubated for 2 h with phosphate-buffered saline alone (B) or PMA (C) on cover slips and then stained for DNA and histone 2A. Arrows indicate NET-forming cells (bar represents 20 μm). The same images are shown at a higher magnification in supplemental Figure 11. (D) The purified samples were incubated for 2 h with phosphate-buffered saline alone, LPS, or PMA and then examined for the magnitudes of NET formation by measuring DNA release (means ± SD from triplicate cultures). Data are representative of 2 independent experiments. **P < .01, ***P < .001 between the indicated samples.