Human polymorphonuclear (PMN) cells were evaluated for phagocytic activity, measured by the uptake of green-fluorescent beads. (A) Flow cytometry analysis showed an increase in mean fluorescence intensity (MFI) of PMN cells treated with either MTB or CW. Microscopy showed that the level of bead uptake by an untreated PMN cell (B) was increased in PMN cells treated with CW (C). Photographs were taken at 600× magnification and the bar drawn in figure 2C represents 5 uM. The data shown are representative of PMN cells assayed in triplicate for each test condition.