Upregulation of IL-2Rγc Expression in huASMC by IL-4 and IL-4/GM-CSF. Alpha-smooth muscle isoactin positive Human ASMC (Clonetics) in T-75 flasks were starved for 24 h in 0.1% FBS containing medium M199. The cells were then either stimulated with BSA (vehicle) (1 μg/ml), IL-4 (0.5 nM), GM-CSF (0.4 nM), or IL-4/GM-CSF (0.5 nM/0.4 nM) for 24 hours. The IL-4 and IL-4/GM-CSF stimulated cells had increased IL-2Rγc expression compared to the BSA (vehicle) group. Fibronectin polyclonal rabbit antibody (Sigma) (1:250) was used as an irrelevant isotype control.