miR-155-induced autophagy promotes the formation of mycobacterial autophagosomes.

<p>(A) RAW264.7 cells stably expressing GFP-LC3 were transiently transfected with control or miR-155 mimic and then infected with Texas Red-labeled BCG for 1 h. The co-localization of BCG with LC3 was detected by confocal microscopy. (B) Quantification of the co-localization of BCG with LC3-positive autophagosomes is shown. (C) RAW264.7 cells were transiently transfected with control or miR-155 mimic, and then infected with Texas Red-labeled BCG for 1 h. Endogenous LC3 was stained with LC3 antibody followed by Alexa Fluor 488-conjugated goat anti-rabbit IgG (Green). The co-localization of BCG with endogenous LC3 was detected by confocal microscopy. (D) Quantification of the co-localization of BCG with LC3-positive autophagosomes is shown. (E) After transient transfection with control or miR-155 mimic, RAW264.7 cells were infected with Texas Red-labeled BCG for 1 h, and then were labeled with a specific fluorescent dye MDC (50 µM) for autophagic vacuoles. The co-localization of BCG with MDC-positive autophagic vacuoles was detected by confocal microscopy. (F) Quantification of the co-localization of BCG with MDC-positive autophagosomes is shown. Cells treated with rapamycin were used as a positive control. Arrows indicate the co-localization of BCG with autophagosomes; scale bar = 5 µm. Data are shown as the mean ± SEM of three independent experiments (n = 100 phagosomes). **, p<0.01; ***, p<0.001.