Figure 3

Inhibition of the intracellular survival of F. novicida in THP-1 macrophages by AR-12 involves an autophagy-dependent mechanism. (A) The autophagy inhibitor 3-MA prevented AR-12-induced inhibition of intracellular bacterial survival. THP-1 macrophages were infected with F. novicida and then treated for 3 h with 2 μM AR-12 or DMSO in the presence and absence of 10 mM 3-MA as indicated. The number of surviving intracellular bacteria was determined and expressed as a percentage of that in the DMSO only group. Points, mean; bars, ± SD (n = 3). **P < 0.01. (B) Chloroquine, an inhibitor of lysosomal degradation, prevented AR-12-induced inhibition of intracellular bacterial survival. THP-1 macrophages were infected with F. novicida and then treated for 3 h with 2 μM AR-12 or DMSO in the presence and absence of 10 μM chloroquine as indicated. The number of surviving intracellular bacteria was determined and expressed as a percentage of that in the DMSO only group. Points, mean; bars, ± SD (n = 3). **P < 0.01.