Figure 4.

Dose dependence and kinetics for the IL-4–mediated upregulation of LTC₄S protein expression. (a) Dose-dependent effects at 5 d of IL-4, from 0.1 to 50 ng/ml, on LTC₄S protein with a constant concentration of SCF (100 ng/ml), as demonstrated by SDS-PAGE immunoblot. Single lanes containing lysates from 10⁵ hMCs treated for 5 d with SCF alone, and with SCF plus IL-13 (10 ng/ml), are included. (b) Kinetic effects of IL-4 (10 ng/ml) on LTC₄S protein in hMCs incubated for 0 to 5 d with SCF (100 ng/ml) to maintain viability. The displayed blots are representative of three experiments each.