Figure 1

Dose-response and time-course of TNFα-induced IL-8 protein expression in A549 cells. A. Dose-response. The top panel illustrates a typical western blotting image of IL-8 and β-actin protein detections. After starving for serum overnight, A549 cells were stimulated with different doses of TNFα as indicated for 24 hours. Equal amount of total protein from each sample was separated by 16.5% SDS-PAGE and immunodetected by the western blotting using anti-human IL-8 or β-actin antibodies. Middle panel-Quantitation of secreted IL-8 level by densitometric analysis. Results from each group are presented as mean ± SD of 4 samples from two separate experiments. Bottom panel-Quantitation of cell lysate IL-8 level by densitometric analysis. **p < 0.01 vs. control (0 ng.ml TNFα). B. Time-course. Top panel-Representative western blotting image of IL-8 and β-actin protein detections. After starving for serum overnight, A549 cells were stimulated with TNFα (15 ng/ml) for different time (h) as indicated. Middle panel-Quantitation of secreted IL-8 protein level by densitometric analysis. Bottom panel-Quantitation of cell lysate IL-8 protein level by densitometric analysis. *p < 0.05 and **p < 0.01 vs 0 dosage of TNFα or 0 h control.