FIG. 7.

Campylobacter-induced IL-8 secretion is dependent on NF-κB activation. (A) T84 cells were incubated with C. jejuni 81-176 (MOI, ∼10) in the presence of cycloheximide for varying lengths of time. T84 cells treated with TNF-α were used as a positive control. −, no treatment. The cells were washed and lysed, and the cell lysates were analyzed by SDS-PAGE and Western blotting with probing for IκB-α. The blots were stripped and reprobed for tubulin as a loading control. Representative results from three independent experiments are shown. (B) Polarized T84 cells were pretreated with the NF-κB inhibitor SN50 (18 μM), quinazoline (28 μM), or TPCK (50 μM) for 30 min and then incubated with C. jejuni 81-176 in the presence of the inhibitor at 37°C for 24 h. No significant difference was detected between the transepithelial resistance before incubation and that after incubation. The apical and basolateral media were collected individually, and the IL-8 concentrations were determined by ELISA. The data are means for three independent experiments; error bars, standard deviations.