FIG. 3.

(A) Expression of LFA-1 on HL-60 cells grown in the presence of DMSO or PMA for 72 h. The expression of LFA-1 was determined by the reactivity of the cells with monoclonal antibodies against CD11a. The proportion of cells reacting with the antibody (given within brackets) is the mean value of three experiments. Representative results of cell distributions obtained by a fluorescence-assisted cell scanner are shown. (B) Extracellular release of LDH, indicative of cell lysis, from HL-60 cells grown in the presence of DMSO or PMA and incubated for 1 h with various concentrations of leukotoxin. Mean values of three experiments are shown.