Figure 2. MSCs were infected with M.tb. (A) Colony forming units (CFU) of M.tb in MSCs. (B) MSCs were infected with M.tb for 72 hours, as imaged by confocal microscopy. Scale bars: 20 μm. Green color represents M.tb GFP. Blue color represents nuclei. (C) Bodipy 493/503 assay in MSCs infected with M.tb. Scale bars: 20 μm. Red color represents M.tb GFP. Green color represents neutral lipids. Blue color represents nuclei. (D) Edu assay in MSCs infected without or with M.tb. Scale bars: 20 μm. (E) Morphology of exosomes derived from M.tb infected MSCs, as imaged by TEM. Scale bars: 100 μm. (F) Concentration and diameter distribution of Exo-MSCs-M.tb, as detected by NTA. (G) Detection of exosomal markers CD63, CD81, Hsp70, Hsp90, and TSG101, as detected by flow cytometer.