Phospholipase C-Related Catalytically Inactive Protein Participates in the Autophagic Elimination of Staphylococcus aureus Infecting Mouse Embryonic Fibroblasts
Figure 1
PRIP deficiency in mouse embryonic fibroblasts (MEFs) induces S. aureus accumulation in autophagosome-like vacuoles.
(A–C) Comparison between S. aureus-containing autophagosome-like vacuoles in wild-type (WT) and PRIP double-knockout (DKO) MEFs. MEFs transiently expressing RFP-LC3 were incubated with S. aureus (ATCC 29213). After 1.5 h incubation, cells were washed with 100 µg/mL of gentamicin-containing medium and further incubated with gentamicin-containing medium until 3 or 4.5 h post-infection. Extracellular (ext.) S. aureus cells were immunostained with anti-protein A antibody (green), and intracellular S. aureus cells were defined as DAPI single-positive signals (A). Images at 3 h post-infection obtained by confocal laser microscopy are shown. Enlarged images of the boxed areas of the left image (scale bar: 10 µm) are shown in the middle and right images (scale bar: 2 µm). Representative images from three independent experiments are shown. The graph in (B and C) shows the numbers of intracellular S. aureus cells and of S. aureus cells localized to LC3-positive autophagosome-like vacuoles per cytosol area (0.01 mm2), respectively. Values represent means ±SEM (n = 20 cells analyzed at each time-point). Reproducible results were obtained from three independent experiments. *p<0.05 and ***p<0.001 relative to corresponding WT values.