Figure 4.

Cs-DS loaded with anti-cystatin C siRNA improves the intracellular killing of laboratory and clinical strains of Mtb with different drug-resistance phenotypes in human macrophages. Human monocyte-derived macrophages were treated with Cs-DS loaded with anti-CstC siRNA or scramble control siRNA 72 h before infection with (a) the laboratory strain H37Rv and three clinical strains of Mtb with different levels of drug resistance. Bacterial intracellular survival was evaluated at discrete time points. Line plots depict the average CFU per sample; (b) the bar plot of CstC mRNA levels demonstrates the silencing efficacy of Cs-DS during infection with H37Rv. Western blot image demonstrates the silencing of CstC protein by Cs-DS at the moment of infection (t = 0 h). The respective bar plot was calculated from band intensity using β-tubulins as a calibrator. The values depicted are the average of three independent experiments. Error bars represent the standard error of the mean. ** p ≤ 0.01, and *** p ≤ 0.001.