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. 2011 Nov 3;7(11):e1002356. doi: 10.1371/journal.ppat.1002356

Figure 1. LLO is required for efficient entry of L. monocytogenes into HepG2 cells.

Figure 1

(A) HepG2 cells were infected with isogenic WT (DP10403S), LLO-deficient (Δhly), InlAB-deficient (ΔinlAB), LLO- and InlAB-deficient (ΔhlyΔinlAB), or LLO-complemented (Δhly + pAM401hly; ΔhlyΔinlAB +pAM401hly) bacteria (MOI = 20) for 30 min at 37°C. Gentamicin was added for 1 h and the CFUs were enumerated as described in methods. Results were the mean ± SEM (n≥3) and expressed relative to WT. Statistics indicated here and elsewhere are as follows: * p<0.05; ** p<0.005. (B) to (D) Cells were infected with WT, LLO-deficient (Δhly), LLO- and InlAB-deficient (ΔhlyΔinlAB), or LLO-complemented (Δhly + pAM401hly; ΔhlyΔinlAB + pAM401hly) bacteria (MOI = 20) for 30 min at 37°C. Cells were washed, fixed, and labeled with fluorescent antibodies and DAPI. (B) Representative images of WT extracellular bacteria (green), total bacteria (red), and HepG2 nuclei (blue). The arrow indicates an internalized bacterium. Scale bar = 10 µm. In (C) and (D), results were the mean ± SEM (n≥3) and were expressed relative to WT.