FIGURE 3.

A, effect of ESAT-6 on IL-8 AP-1 and NF-κB DNA binding activities. H441 cells were treated with or without ESAT-6 (5 μg/ml) for the indicated times, and AP-1 and NF-κB DNA binding activities in the nuclear extracts were determined by an electrophoretic mobility shift assay. B, effect of ESAT-6 on the wild type and mutant IL-8 promoter activities. H441 cells were transiently transfected with wild type, AP-1, NF-κB, or AP-1 and NF-κB double mutant (Dm) IL-8-luciferase promoter plasmids (−546/+44 bp) and then treated with or without ESAT-6 (5 μg/ml) for 6 h. Luciferase activities were measured and normalized to total cell protein. Data shown are means ± S.E. (error bars) (n = 3–4). *, p < 0.05 compared with untreated cells.