Inhibition of host cell necrosis limits M. tuberculosis replication. (A) Example confocal microscopy images showing GFP-Mtb (green), PI (red), and DAPI (blue) staining of resting or activated GM-CSF or M-CSF macrophages at 7 d after infection in control cells (DMSO only) or cells treated with 10 µM of the shown necrosis inhibitors. Cells outlined in white dotted lines are considered to be PI positive. Bars, 10 µm. (B) Quantification of the effect of treating infected resting (blue) or activated (red) GM-CSF (dots) or M-CSF (squares) with three necrosis inhibitors compared with untreated control macrophages at 7 d after infection with GFP-Mtb. (C) Quantification of the effect of treating infected resting (blue) or activated (red) GM-CSF (dots) or M-CSF (squares) with three necrosis inhibitors on the proportion of cells with a PI-positive (PI+) nucleus compared with untreated control macrophages at 7 d after infection with GFP-Mtb. Data points show the percent reduction for each independent experiment, and the bars show the overall mean.