Phenotype of NK cells after coculture with autologous APCs. NK cells were stained for different surface markers after coincubation for 48 hours alone or with monocytes, DC, macrophages, and macrophages activated with 100 ng/mL (macrophage^{low LPS}) or 200 ng/mL (macrophage^{high LPS}) LPS at 10:1 ratio and analyzed by flow cytometry. Fluorescence intensities were calculated as the geometric mean fluorescence intensity of the sample − geometric mean fluorescence intensity after isotype-matched control mAb staining. The mean ± SD from 3 independent experiments using cells derived from different donors is shown. Instrumental settings were adjusted so that the fluorescence intensity of all samples stained with an isotype-matched control mAb was similar.