Figure 7. Inhibition of miR-33 and miR-33* enhances targeting of M. tuberculosis for autophagy and bacterial killing.

(a) Immunofluorescence imaging of peritoneal macrophages treated with control anti-miR, anti-miR-33, anti-miR-33*, or IFN-γ (200 units/mL) and infected with an Mtb H37Rv strain co-expressing mCherry and anhydrotetracycline-inducible GFP for 48 h. Metabolically active Mtb are GFP and mCherry positive, whereas inactive or non-viable bacteria are mCherry positive only. Scale bar = 25 μm. Quantification of bacterial viability in peritoneal macrophages infected with Mtb H37Rv or ΔesxA mutant strain shown on the right. (b–c) Quantification of Mtb survival in wild type (WT) or miR-33^−/− BMDMs treated with or without IFN-γ (200 units/mL) using (b) the dual fluorescence viability assay as in (a), or (c) colony forming units (CFU) 5 days post-infection. (d) Mtb survival in wild type (WT) or Atg16l1^−/− BMDMs treated with control anti-miR, anti-miR-33 or anti-miR-33*, measured by CFU 5 days post-infection. (e) Mtb survival in wild type (WT) or cGAS^−/− BMDMs treated with control anti-miR, anti-miR-33 or anti-miR-33*, measured by CFU 5 days post-infection. NS, not significant; *P≤0.05, **P≤0.005 (Two-way ANOVA (a–e)). Data are from one experiment and are representative of 2 independent experiments (a-e; mean ± s.e.m) with similar findings.