Figure 6

The relative importance of AP-1, NF-IL-6 and NF-κB binding sites in the IL-8 promoter. (A) Diagram of the constructs used in these experiments. The AP-1, NF-IL-6 or NF-κB site in the IL-8 promoter (-133 to +44 bp), linked to the luciferase gene, was mutated. (B) Mutational analysis of the cis-elements required for L. pneumophila-induced IL-8 promoter activity. The indicated wild-type and mutated plasmids (40 ng) were transfected into A549 cells, and the cells were subsequently infected with AA100jm strain (MOI of 100) for 48 h. The activities are expressed relative to that of cells transfected with -133-luc without further treatment, which was defined as 1. Data are mean ± SD values of three independent experiments. (C) Diagram of the constructs used in these experiments. (D) L. pneumophila-induced IL-8 gene expression is specific for the NF-κB region of the IL-8 gene. The activities are expressed relative to that of cells transfected with -50-luc without further treatment, which was defined as 1. Data are mean ± SD values of three independent experiments. *, P < 0.05; **, P < 0.005; #, P < 0.001; ##, P < 0.0005 (compared to uninfected cells).