Figure 2

Inhibition of intracellular survival of F. tularensis in THP-1 macrophages by AR-12. (A) Dose-dependent effect of AR-12 (3 h treatment) on the intracellular survival of F. novicida in THP-1 macrophages. Post-treatment CFU values are expressed as a percentage of those in the control group. Columns, mean; bars, ± SD (n = 3). *P < 0.05, **P < 0.01. (B) Dose-dependent effect of AR-12 (3 h treatment) on the intracellular survival of F. tularensis (a type A strain, Schu S4) in THP-1 macrophages. Points, mean; bars, ± SD (n = 3). *P < 0.05, **P < 0.01. (C) AR-12 did not show cytotoxic effect on the viability of F. novicida infected THP-1 macrophages. Cells infected with F. novicida and treated with the indicated doses of AR-12 for 3 h. Cell viability was assessed by the MTT assay. Points, mean; bars, ± SD (n = 3). (D) Effect of AR-12 on the growth of F. novicida in modified TSB broth. Points, mean; bars, ± SD (n = 6).