Evaluation of functional properties of PMNs. Functional properties of PMNs were assessed in the absence or presence of IL-2–activated NK-cell supernatant after 18 to 24 hours of culture. (A) Representative FACS analysis of PMNs coincubated with 1-μm fluorescent labeled latex beads in the absence (left panel) or presence of IL-2–activated NK cells supernatant (right panel). Shaded profiles represent uptake when PMNs were incubated on ice, and open profiles represent active uptake at 37°C. The percentage of PMNs phagocytosing 1-μm latex beads is indicated. (B) Quantitative representation of bead uptake by PMNs from 4 individual experiments. (C) Evaluation of the phagocytic capacity of PMNs when cultured with supernatants from NK cells stimulated with IL-2, IL-21, IL-15, IL-12, IL-18, or a combination of IL-12 plus IL-18 (n= 1). (D) Correlation analysis between the percentage of apoptotic PMNs and the percentage of phagocytosing PMNs. (E) Quantitative representation of the amount of superoxide produced by PMNs from 3 individual experiments. Amount of superoxide produced by PMNs was determined by measuring the electron spin of a superoxide radical. Results are expressed as mean ± SEM. ***P < .001.