FIG. 4.

Role of TLR2 in the induction of HBD-2, HBD-3, and IL-8 by F. nucleatum in HOK-16B cells. HOK-16B cells were transfected with control nonsilencing or TLR2-specific siRNA. After 24 h of incubation, the cells were infected with live F. nucleatum at an MOI of 1,000 for 24 h. (A) Gene silencing was assessed by real-time RT-PCR and flow cytometry 24 h after transfection. (B) The expression of HBDs and secretion of IL-8 by F. nucleatum were evaluated by real-time RT-PCR and ELISA, respectively. The mean ± the SEM values of the relative copy numbers from 12 real-time RT-PCR assays were expressed as relative expression compared to that of control cultures without any treatment. *, P < 0.05; and **, P < 0.001 versus no infection. P values indicate differences in the F. nucleatum-induced upregulation of HBDs between control and TLR2-specific RNAi.