Fig. 1.

PDCoV infection induces autophagy in LLC-PK1 cells. (A) LLC-PK1 cells were mock infected or infected with PDCoV (MOI = 2). The expressions of LC3-II and p62 were analyzed by western blot at 6, 12, 24 and 30 hpi. (B, C) Results were presented as the ratio of target protein band intensity to β-actin band intensity. (D) LLC-PK1 cells were transfected with plasmid GFP-LC3 for 24 h, followed by PDCoV infection (MOI = 2). The fluorescence signals were visualized by confocal immunofluorescence microscopy at 24 hpi. Scale bars: 10 μm. (E) Determination of cytotoxicity of CQ by CCK-8 assay. (F) LLC-PK1 cells were transfected with plasmid ptfLC3 for 24 h, followed by mock-treated or CQ (12.5 μg/mL)-treated for 4 h. Then, the cells were mock-infected or infected with PDCoV (MOI = 2). After PDCoV adsorption for 1 h, the cells were further cultured in fresh medium in the absence or presence of CQ (6.25 μg/mL). The fluorescence signals were visualized by confocal immunofluorescence microscopy at 24 hpi. Scale bars: 10 μm. Values represent the mean ± SEM for three independent experiments. *P <  0.05; **P <  0.01.