Fig. 1

Activation of NF-κB-luciferase constructs in Caco-2 cells. a Schematic illustration of the NF-κB-luciferase and control TATA-luciferase constructs. The NF-κB-luciferase construct contained the firefly luciferase coding region, a TATA box and three NF-κB binding sites whereas the NF-κB binding sites were deleted in the control. b Caco-2 cells were transfected with either the NF-κB-luc or TATA-luciferase construct. Stable transfectants grown in Se-supplemented medium were incubated with flagellin (100 ng/ml) or TNFα (20 ng/ml) for up to 8 h and cell extract prepared for measurement of luciferase activity. Both flagellin and TNFα elicited a stimulation of luciferase activity in the NF-κB-luciferase cells but not in the TATA-luciferase controls (TNFα dashline with triangle and flagellin dashline with square)