The data presented above support the observation that LLO is required for LC3-GFP colocalization with L. monocytogenes. To determine if LLO was the only L. monocytogenes determinant of pathogenesis necessary to induce autophagy, we examined the interaction of LC3-GFP in BMDMs with the non-pathogenic Gram-positive bacterium Bacillus subtilis engineered to express and secrete LLO or a related cholesterol dependent cytolysin, perfringolysin O (PFO). These modified bacteria have previously been shown to escape into the host cell cytosol, although the efficiency of escape is less than that observed for wild-type L. monocytogenes [29, 30] .