Dose response and kinetics of LFA-1 and ICAM-1 expression induced by IL-4. Cultured human mast cells (2 × 10⁵) stimulated (A) with various concentration of IL-4 for 3 days and (B) with IL-4 (10 ng/mL) for the periods indicated in the presence of SCF and IL-6 were incubated with mouse MoAbs specific for human ICAM-1 (RR1/1) (□), LFA-1α (TS1/22) (▵), and LFA-1β (TS1/18) (▴), respectively, and were subsequently stained with FITC-conjugated goat antimouse IgG. Cells were then analyzed by flow cytometery. The mean fluorescence intensity was measured in log scale and calculated by dividing the log scale axis equally into 255 channels. Each result is one representative out of three.