Fig. 1

VSV-FAST increases 4T1 cell fusion and cell death in vitro. (A) 4T1 cell monolayers were cultured with vehicle (uninfected) or infected at an MOI of 1 with VSV-GFP, VSV-p10ARV, VSV-p14, or VSV-p15. Images of syncytia were acquired 12.5 h after infection. Scale bar is 100µM. The number of nuclei per syncytia was quantified at 15 h (n = 6 per group). ^†p < 0.05 compared to VSV-GFP, ^‡p < 0.05 compared to VSV-p10ARV, ^§p < 0.05 compared to VSV-p14. (B) 4T1 cell monolayers were infected in culture for 20 h at an MOI of 1 or 10 with VSV-GFP or VSV expressing different FAST proteins. Viability was determined by MTT assay (n = 3 per group). ^*p < 0.05 compared to untreated, ^†p < 0.05 compared to VSV-GFP, ^‡p < 0.05 compared to VSV-p10ARV, ^§p < 0.05 compared to VSV-p14. (C) Monolayers of 4T1 cells or MCF7 cells were infected at an MOI of 5 for 24 h. Supernatants were collected and viral titres were determined by plaque assay (n = 3 per group). ^*p < 0.05 compared to VSV-GFP. (D) Spheroids were collected from 4T1 and MCF7 cells infected with VSV-GFP or VSV expressing different FAST proteins for 20 h. Viability was determined by acid phosphatase assay (n = 3 per group). ^*p < 0.05 compared to untreated, ^†p < 0.05 compared to VSV-GFP, ^‡p < 0.05 compared to VSV-p10ARV, ^§p < 0.05 compared to VSV-p14