FIG 7.

The NF-κB transcription factor is involved in VpOmpU-mediated proinflammatory responses. (A) Decrease in production of TNF-α in response to VpOmpU with the use of an inhibitor of NF-κB (MLN4924) in both RAW 264.7 and THP-1 cells. Results are expressed as mean ± SEM from three independent experiments (*, P < 0.05; **, P < 0.01; ***, P < 0.001; ns, P > 0.05 [versus cells treated with VpOmpU only]). (B) Increase in phosphorylated IκB and decrease in total IκB in response to VpOmpU with increase in time in both RAW 264.7 and THP-1 cells. Cells were treated with VpOmpU and incubated for different times. Whole-cell lysates were prepared and analyzed by Western blotting for phosphorylated and total IκB. β-Actin and GAPDH were used as loading controls for the whole-cell lysates. (C) Translocation of NF-κB subunits c-Rel in RAW 264.7 and p65 in THP-1 from the cytoplasm to the nucleus in response to VpOmpU. Lamin B1 was used as a loading control for nuclear lysates, and β-actin and GAPDH were used as loading controls for the cytoplasmic lysates.