IL-8 production in PBECs is not dramatically affected by CSE, strongly enhanced by PMA and sensitive to broad-spectrum metalloprotease inhibitor TAPI-2. PBEC were obtained from non-smokers (n = 7), healthy smokers (n = 9) and COPD patients (n = 8). Cells were growth factor-deprived overnight, pre-treated with and without GW280264 (2.5 μM), TAPI-2 (2.5 μM) or medium/DMSO for 30 min and incubated with and without CSE (2.5%) or PMA (5 ng/ml) for 24 hours. A) IL-8 production is not significantly different in the 3 different subject groups under basal conditions. Absolute values and medians are shown. B) CSE induces a slight but significant increase in IL-8 production in the healthy smoker and COPD group. Absolute values are shown and significance is indicated (* = p < 0.05). C) PMA induces a similar increase in IL-8 production in PBECs from the 3 different subject groups. Absolute values and medians are shown. D) TAPI-2 reduced IL-8 production in PBEC from the 3 different subject groups. Significance is indicated. Absolute values are shown. Significance is indicated (* = p < 0.05 and ** = p < 0.01).