Induction of autophagy in THP-1 macrophages by AR-12. (A) AR-12 induced autophagosome formation in uninfected THP-1 macrophages. THP-1 cells were induced to differentiate by treatment with 12-O-tetradecanoylphorbol 13-acetate and then treated as indicated. Autophagosomes were visualized by immunofluorescence microscopy after staining with antibody against LC3-II. Scale bar, 10 μm. (B) AR-12 induced the accumulation of LC3-II in uninfected THP-1 macrophages. Above: Western blot analysis of the time-dependent effect of AR-12 on LC3-II formation in uninfected THP-1 macrophages. β-Actin was used as a loading control. Below: The ratio of LC3-II/β-actin in the blot after different time of AR-12 exposure (C) AR-12 did not affect the viability of uninfected THP-1 macrophages. Cells were treated with the indicated doses of AR-12 for 3 h and cell viability was assessed by the MTT assay. Points, mean; bars, ± SD (n = 6).