Fig. 4
Efficacy of selected sirtuin inhibitors to reduce intracellular Mtb growth in macrophages or PBMCs. Control conditions of H37Rv-GFP growth inside (A) fully differentiated hMDMs, or (B) bulk PBMC cultures. Uninfected host cells and the MOI1 infection control was compared to the positive controls with antibiotics (RIF + INH) or PBA (internal HDAC inhibitor control) for intracellular Mtb growth (%). (C) Representative microscopy images of the MOI1 infection control at day 0 and 3, in hMDM (upper panel) or PBMC cultures (lower panel). Immune cells (grey color) and H37Rv bacteria (green color) were visualized in the microscopy images. Arrows indicate H37Rv-GFP infected cells. Magnification x20. Note the smaller size of the lymphocytes compared to hMDMs. Efficacy of the selected compounds, tenovin, suramin, salermide and cambinol, to reduce intracellular growth of H37Rv-GFP inside hMDMs (D-G) or PBMC cultures (I-L), including comparison of intracellular Mtb growth reduction by treatment with PBA or the sirtuin inhibitors in (H) hMDMs or (M) PBMCs. In Fig. 4H and M, respectively, individual data from n = 12 donors present the µM-doses for each selected sirtuin inhibitor that were most effective (0.001, 0.01, 0.1 or 1 µM) in reducing intracellular Mtb growth as compared to 2mM of PBA. (N) Efficacy of the selected compounds to reduce intracellular growth of H37Rv-GFP inside hMDMs assessed using CFU counts at day 3. Data assessed with IncuCyte at day 3 is presented in individual dot plot graphs or bar graphs (median and range) from n = 12 donors (n = 4 donors for CFU counts in (N)) and was analyzed using a paired Friedman test (A-B), Kruskal-Wallis and Dunn´s multiple comparisons test (D-G and I-L) and repeated measures ANOVA with uncorrected Fisher’s LSD (H, M). The dotted lines indicate 50% intracellular Mtb growth and the MOI1 control was set to 100%. *P < 0.05, **P < 0.01, ****P ≤ 0.0001.
