Effect of NTZ on Mtb proliferation and survival of THP-1 cells.

<p>(A) Differentiated THP-1 cells infected with Mtb H37Rv bearing a luciferase-reporting plasmid were treated with various concentrations of NTZ or TIZ for the indicated times. Intracellular Mtb was measured as luciferase activity at 24, 48 and 72 h. (B) Infected THP-1 cells were treated as in (A) but after 24 h treatment the drugs were removed and cells were incubated with medium without drug. Luciferase activity was measured at 24 h, 48 h (24 h post-wash) and 72 h (48 h post-wash). (C) Differentiated THP-1 cells were exposed to various concentrations of NTZ, TIZ or rapamycin for 4 h. Endogenous LC3 processing (using LC3 antibodies) and mTORC1 activity were determined by immunoblotting as in <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1002691#ppat-1002691-g002" target="_blank">Figure 2</a>.Viability of THP-1 cells treated with drugs for the indicated times was measured with the MTT assay (D) or by propidium iodide (PI) staining (E, F). PI levels were measured quantitatively by automated microscopy, and viable cells was calculated as the percentage of PI-negative cells. (F) After drug removal at 24 h, THP-1 cell survival was measured by PI at 48 h (24 h post-wash) and 72 h (48 h post-wash).