Fig 4.

MyD88 is not involved in invasion of cells by STEC strain 98NK2 or 98NK2ΔfliC. (A) Invasion assays with STEC strains 98NK2 and 98NK2ΔfliC in HCT-8 cells transiently transfected with MyD88-DN, IRAK-Wt, IRAK-Wt, TLR5-DN, or TLR5-Wt approximately 24 to 36 h prior to invasion assays (as described in Materials and Methods). Results shown are the means plus SDs from three independent experiments in duplicate wells. Significant differences are indicated as follows: *, P values ranged from 0.0002 to 0.0494; NS, not significant. (B) HCT-8 cells were transfected with siRNA directed against MyD88 or with negative-control siRNA, and RNA was extracted 24 h later (as described in Materials and Methods). MyD88 mRNA was quantitated by real-time RT-PCR. Results are expressed as the fold increase in the concentration of MyD88 mRNA relative to control cells. Data shown are the means plus SDs from three independent experiments performed in triplicate. Significant differences are indicated as follows: **, P = 0.0028. (C) HCT-8 cells were transfected with siRNA directed against MyD88 or with negative-control siRNA and used in invasion assays performed with strain 98NK2 approximately 48 h later (as described in Materials and Methods). Results shown are the means plus SDs from three independent experiments, each performed in quadruplicate. NS, not significant.