FIG 3 .
Rab4a, Rab11b, and Myo5b are required for intracellular survival of Y. pestis. RAW 264.7 macrophages were transfected with siRNAs targeting Rab4a, Rab11b, or Myo5B. (A and B) Forty-eight hours after transfection, RNA samples were harvested for qRT-PCR (n = 9) (represented as relative expression of scrambled-siRNA-treated cells) (A) or cell viability was determined (n = 5) (B). (C and D) To determine the impact of RNAi on Y. pestis survival, transfected RAW264.7 macrophages (n = 6) were infected with Y. pestis CO92 pCD1(-) LuxPtolC (MOI of 10), and intracellular bacterial numbers were determined by bioluminescence (in RLU) at 2 h (C) or 10 h (D) postinfection and compared to the values for scrambled (Scr) controls. (E) At 10 h postinfection, a subset of samples (n = 3) were harvested for conventional bacterial enumeration. (F) Percent of intracellular bioluminescence at 10 h postinfection compared to 2 h postinfection. Values that are significantly different by one-way ANOVA with Tukey’s posthoc test are indicated by asterisks as follows: **, P ≤ 0.01; ***, P ≤ 0.001. Values that are not significantly different (ns) are indicated.