Chemokine mRNA inhibition in A549 cells. 2 × 107 A549 cells were pretreated with 5 mM N-acetyl-L-cysteine (NAC) or 500 nM dexamethasone (DEX). After 1 hr the pretreated cells were either infected with RSV (MOI = 1) or stimulated with TNFα (100 ng/ml) for 24 hr. The graphs show the percent inhibition for each chemokine mRNA after normalization to GAPDH. Shown is representative of two independent experiments.