MSU crystals reduce intracellular BCG viability in a phagolysosome maturation dependent and ROS mediated manner.

<p>BCG infected dTHP-1 cells were stimulated or not with 5 μg/ml MSU and CFU assays were performed at day 3 post-infection. (<b>A</b>) In order to ascertain whether phagolysosome maturation was responsible for intracellular mycobacterial killing, 10 μM chloroquine (Cq) or 20 mM NH₄Cl was added to BCG-infected cells together with MSU. Results are expressed as mean ± SD of CFU values performed in triplicate and are representative of two independent experiments. * p < 0.001 in comparison with non-stimulated control cells. (<b>B</b>) In order to ascertain the role of ROS in intracellular mycobacterial killing, 100 U/ml PEG-catalase was added to BCG infected cells together with MSU. Results are expressed as mean ± SD of CFU values performed in triplicate and are representative of two independent experiments. * p < 0.001 in comparison with non-stimulated control cells.