ESCRT is required to traffic Mtb to the lysosome.

(A) RAW264.7 cells were treated with control siRNA (Con), individual siRNAs targeting Hrs (#9 or #12), or siRNA pools targeting Tsg101 or Rab7 and infected with Mtb. Bacterial colony forming units (CFU) were enumerated 2 d post-infection and are normalized to the average number of CFU in control wells from three independent experiments. Results reflect the mean +/− SEM. *p = 0.018; ***p = 0.0002; ****p<0.0001, unpaired Student's t-test. (B) Composite images and quantification of Mtb-GFP or BCG-GFP (in green) and RAW cell LAMP1, TfR, or LysoTracker (in red) at 24 hpi. Regions indicated by yellow circles are shown in higher magnification in adjacent panels. In graphs, data points are the mean fluorescence intensity (MFI) around at least 100 phagosomes for each condition; bars show mean +/− SEM. Data are representative of at least three experiments; p<0.0001 for all siRNAs compared to controls.