The Serine Phosphatase SerB of Porphyromonas gingivalis Suppresses IL-8 Production by Dephosphorylation of NF-κB RelA/p65
Figure 5
SerB dephosphorylation of p65 inhibits IL8 promoter activity and IL-8 production.
(A) TIGKs were transiently co-transfected with Myc (Vector) or Myc-SerB, and either of GFP, GFP-NF-κB p65 or GFP-NF-κB p50, along with pIL-8 κB-Luc luciferase reporter for IL8 promoter activity or pRL-CMV Renilla luciferase control. Cells were stimulated with TNF-α (40 ng/ml) as indicated, and after 3 h TNF-α-induced IL8 κB luciferase activity was measured and normalized to Renilla luciferase. Results are presented as fold relative to the activity of the non-stimulated control and are means ± SD of 6 biological replicates. *, p<0.05. (B) TIGKs were transiently transfected with Myc (Vector) or Myc-SerB and at 36 h after transfection stimulated with TNF-α (5 ng/ml) as indicated. At the indicated time periods, the level of IL-8 in culture supernatants was measured by ELISA. Values are mean ± SD of 6 biological replicates. *, p<0.05. (C) TIGKs were transiently co-transfected Myc (Vector) or Myc-SerB, and either of GFP, GFP-NF-κB p65 or GFP-NF-κB p50. Cells were stimulated with TNF-α (5 ng/ml) as indicated, and after 4 h the level of IL-8 in culture supernatants was measured by ELISA. Values are mean ± SD of 6 biological replicates. *, p<0.05.