Phenotypic and functional characterization of purified NK cells and PE-MΦs of C57BL/6 mice. (A-C) CD11c⁺NK1.1⁺DX5⁺ NK cells were positively selected from PECs by AutoMACS and MoFlo sorting (purity ≥ 99%). (A) Surface phenotyping of purified NK cells by FACS. Representative for 4 independent experiments. (B) NK cell cytolytic activity (mean of triplicates ± SD) of total PECs compared to purified CD11c⁺NK1.1⁺DX5⁺ NK cells against YAC-1 cells (5000 target cells/well). ^*Significantly different from unselected PECs (P < .02, unpaired Student t test). One of 2 independent experiments. (C) IFN-γ production (mean of triplicates ± SD) of total PECs, the DX5⁺ cell fraction (after AutoMACS separation), and the highly purified CD11c⁺NK1.1⁺DX5⁺ NK cells (AutoMACS plus MoFlo sorting). The number of cells was titrated and stimulated with IL-12/IL-18 for 72 hours. No IFN-γ was detectable in unstimulated cells (not shown). Representative of 2 independent experiments. (D) Phenotyping of PE-MΦ monolayers by FACS. After adherence and washing, the PE-MΦs were detached by accutase treatment and stained for lymphoid markers. Detection of NK cells (CD3^-DX5⁺), T cells (CD3⁺DX5^-), and NKT cells (CD3⁺DX5⁺) within region R3. Representative of 3 similar experiments.