Figure 4

HSV1-GFP was highly oncolytic to 4T1 monolayers, mammospheres and isolated ALDH ^br and ALDH ^lo cells. (A) 4T1 cells were infected with HSV1-GFP at different MOIs (0, 0.01, 0.1, 0.5 and 1) for 24 hours. The images were visualized using a phase-contrast microscope (top) and a fluorescence microscope for GFP expression (bottom). (B) After a 7 day culture, 4T1 mammospheres were infected with HSV1-GFP at an MOI of 1. At 24 (middle) and 48 (lower) hours after infection, the spheres exhibited a GFP signal compared with the mock-infected control (upper). The images were visualized using phase-contrast (left) and fluorescence microscopy (right). (C) Sorted ALDH^br and ALDH^lo cells were infected by HSV1-GFP at different MOIs (0, 0.1, 0.3 and 1). The cell morphology and GFP expression were visualized using an inverted fluorescence microscope, and overlapping images were taken at 10 (left panels) and 33 hours (right panels) after infection (100 × objective magnifications).