Figure 3

Macrophages infected with Δppe31^Mm show reduced caspase- independent cell death. (A) BMDMs were infected with WT, Δppe31^Mm, or comp-Δppe31^Mm (MOI = 10) for 24h for analysis of morphological changes. Scale bar in 100 μm. (B) BMDMs were infected with WT, Δppe31^Mm, or comp-Δppe31^Mm (MOI = 10). The cytotoxicity was assessed by LDH release assay at indicated times. (C) BMDMs were infected with either WT, Δppe31^Mm, or comp-Δppe31^Mm (MOI = 10 or 5) for 24 h, and cell death was detected by PI staining and then examined by flow cytometry. (D) BMDMs were infected with WT, Δppe31^Mm or comp-Δppe31^Mm (MOI = 10) in the presence or absence of Z-VAD-FMK (20 μM), a caspase inhibitor, then cells were stained with PI and then examined by flow cytometry. Data are shown as mean ± S.E.M. of three independent experiments. *p < 0.05, **p < 0.01. WT, wild-type M. marinum; UI, uninfected; SC, solvent control (0.1% DMSO); ns, no significant.