Fig 3.

Effects of siRNAs directed against category II host genes on human gene expression and internalization of Listeria. (A) Inhibition of host gene expression. HeLa cells were transfected with siRNA pools targeting the indicated category II host genes. Control transfection conditions and analysis of gene expression were carried out as described in the legend for Fig. 2. (i) Gene expression was analyzed by real-time PCR for all but one of the genes. (ii) In the case of PLCG1 (encoding PLC-γ1 protein), gene expression was assessed by Western blotting, since the probe did not detect expression (see Materials and Methods). Data are means ± SEM for 3 to 5 experiments, depending on the siRNA condition. Statistical analysis by ANOVA gave a P value of <0.0001. *, P < 0.05 relative to the NTC1 or no-siRNA control (by the Tukey-Kramer posttest). (B) Effects of siRNA pools on Listeria internalization. HeLa cells were transfected with siRNA pools directed against the indicated category II host gene. Control transfection conditions and measurement of bacterial entry were carried out as described in the legend for Fig. 2. Data for siRNAs targeting category II genes are means ± SEM for 3 to 5 experiments. Data obtained under the no-siRNA (none), NTC2, or lamin A/C siRNA control condition are from 46, 13, or 13 experiments, respectively. Statistical analysis by ANOVA gave a P value of <0.0001. *, P < 0.05 relative to the NTC1, NTC2, lamin A/C, or no-siRNA control (by the Tukey-Kramer posttest).