FIGURE 6.

Role of MyD88, TLR2, TLR4, and NOD1 in K. pneumoniae ompA mutant-induced cell activation. A, C, E, and G, activation of an NF-κB luciferase reporter plasmid in A549 cells transfected with either control or the indicated siRNA for different pattern recognition receptors, which were left untreated (white bars) or infected for 8 h with different strains. Activity is normalized by correction of Renilla expression and is presented relative to the cells untreated (n = 3). B, D, F, and H, ELISA of IL-8 released by A549 cells transfected with either control or the indicated siRNA for different pattern recognition receptors, which were left untreated (white bars) or infected for 8 h with different strains (n = 3). I, activation of an NF-κB luciferase reporter plasmid in HEK293T cells transfected with HA-NOD1 plasmid, which were left untreated (white bar) or infected with the indicated strains for 8 h. Activity is normalized by correction of Renilla expression and is presented relative to untreated cells (data are means and S.E. (error bars); n = 3). J, siRNA efficiency was quantified by RT-qPCR in samples from the same experiment shown in A–H. mRNA level was normalized to GADPH, and then relative mRNA levels in cells transfected with control siRNA or specific siRNA were compared. mRNA levels in cells transfected with control siRNA were set to 100% (data are means and S.E.; n = 3). Gray bars, CPS-expressing strains; black bars, CPS-negative strains. A–H, Δ, p < 0.05 (results are significantly different from the results for untreated cells; one-way ANOVA); *, p < 0.05 (results are significantly different from those for transfected cells with control siRNA infected with the same strain). I, *, p < 0.05 (results are significantly different from the results for untreated cells; one-way ANOVA).