Pathogenic S. aureus USA300 induces GFP-WIPI-1 puncta formation and becomes entrapped in GFP-WIPI-1 positive autophagosome-like vesicles. GFP-WIPI-1 U2OS cells were infected with mCherry-expressing S. aureus USA300 for 0.5, 1, and 2 h in DMEM/FCS, DMEM, or EBSS. Automated image acquisition and analysis were conducted as described in Figure 3. The quantification of up to 2000 individual cells is presented for GFP-WIPI-1 (in green) and S. aureus USA300 (in red) using either DMEM/FCS (a), DMEM (b), or EBSS (c) for infection ± SD (, each in duplicates). Representative images (2 h infection in DMEM/FCS) are shown (d). Scale bars: 20 μm. From 100 infected cells for each of the treatment condition, the number of cells displaying GFP-WIPI-1 positive autophagosomal-like vesicles entrapping S. aureus USA300 was determined (e) ± SD (, each in duplicates).
