Dynamic growth of M. tuberculosis in distinct subpopulations of human primary macrophages. (A) Intracellular replication of GFP-Mtb in resting (blue line) or IFN-γ–activated (red line) GM-CSF– differentiated macrophages, normalized to 2 h and expressed as the percent increase in CFUs over time. (B) Intracellular replication of GFP-Mtb in resting (blue dots) or IFN-γ–activated (red dots) GM-CSF–differentiated macrophages (expressed as the mean number of GFP-positive pixels per cell) at 2 h, 72 h, and 7 d after infection. (C) Quantification of the mean proportion of GFP-Mtb infected cells in resting (blue dots) or activated (red dots) GM-CSF–differentiated macrophages at 2 h, 72 h, and 7 d after infection. (D–F) Same as in A–C, but with M-CSF–differentiated macrophages. (A–F) Data presented are means ± SEM from three (A, B, D, and E) or at least three (C and F) independent experiments. (G) Analysis of the association of GFP-Mtb with LAMP-2 in resting and activated GM-CSF macrophages infected at an MOI of 1 for 72 h. Representative confocal microscopy images of GFP-Mtb and LAMP-2 marker. Nuclei were stained with DAPI. Insets show magnifications of the outlined cells, highlighting the low level of association of LAMP-2 to bacteria. (H) Quantification of the association of GFP-Mtb with LAMP-2 in resting (blue) or activated (red) GM-CSF macrophages. The number of bacteria analyzed for each condition is displayed as well as the proportions of M. tuberculosis that are considered to be positive for LAMP-2 association (i.e., a mean intensity value of ≥150). (I and J) Same as G and H, but with M-CSF–differentiated macrophages. Bars, 10 µm.