Figure 4

Infection with Δppe31^Mm reduces cell death through JNK-dependent signaling. (A) BMDMs were infected with WT, Δppe31^Mm or comp-Δppe31^Mm (MOI = 10) for the indicated periods of time, and then subjected to Western blot analysis using antibodies raised to p-ERK1/2, p-p38, p-JNK, and β-actin. (B) BMDMs were pretreated with the following MAPK signaling pathways inhibitors U0126 (20 μM), SB203580 (SB; 10 μM), or SP600125 (SP; 20 μM) for 1h, and then infected with WT, Δppe31^Mm or comp-Δppe31^Mm for 30 min, Cells were then incubated with DCFH-DA and analyzed immediately for ROS generation by flow cytometry. (C) BMDMs were pretreated with U0126 (20 μM), SB (10 μM), or SP (20 μM) for 1h, and then infected with WT, Δppe31^Mm or comp-Δppe31^Mm for 24h, cells were stained with PI 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 DPI (10 μM). After 24h, cells were then stained with PI and analyzed immediately for cell death using flow cytometry. Data are shown as mean ± S.E.M. of three independent experiments. *p < 0.05, **p < 0.01, ***p < 0.001. WT, wild-type; M, marinum; UI, uninfected; SC, solvent control (0.1% DMSO); ns, no significant.