Figure 2.

Host cell mechanisms contributing to the maintenance of a long-term infection.A. Initial and final frames of Movie S1 showing the expansion of a group of three infected cells into seven infected cells in a period of 38.15 h. Scale bar: 10 μm.B. Quantitative analysis of the changes in the number of infected cells and fluorescent area occupied by BCG-GFP, the data are from 11 movies. (**) P ≤ 0.01 from two-tailed Student's t-test.C. Analysis by flow cytometry of LTI and RI macrophages showing Annexin V signal intensity distribution. In order to determine cell death, cells were double stained with Annexin V and 7-AAD and gated based on 7-AAD positive signal and GFP-positive signal (infected cells, blue line) or GFP-negative (uninfected cells, red line). Results are represented as % of total in the y-axis versus intensity of Annexin V signal in x-axis. The median fluorescence intensity (MFI) values for each gated population are shown in the histograms. Data are representatives of three independent experiments.D. Time-lapse of Movie S2 showing cell death and efferocytosis as a mechanism for propagation of the infection in the culture of long-term infected macrophages. Scale bar: 10 μm.E. Time-lapse of Movie S3 showing different events of cell division in long-term infected macrophages and distribution of selected bacteria. (i) Infected cell divides and bacteria are segregated into just one daughter cell. (ii) Infected cell divides and bacteria are segregated into both daughter cells. Scale bar: 10 μm.