Fig. 5

MRBV sensitivity can be conferred to resistant cells through direct cell-cell co-culture. a iOvCa147-F8 and iOvCa147-G4 cells were seeded at specific mixtures as indicated to a total of 100,000 cells per well of a 24-well plate. No virus mock-infections at each cell mixture was used as a control to determine relative viability as assessed at 48 h post-infection using CellTiter-Glo®. Expected viability if there was no interaction between subclones was calculated using the data from 100% pure iOvCa147-F8 and 100% pure iOvCa147-G4 MRBV-infected cultures. (**, p < 0.01; ****, p < 0.0001, as determined by paired Student’s t-test) b Fluorescence images of co-cultured cells iOvCa147-F8 (red, DiI-labelled) and iOvCa147-G4 (blue, CMAC-labelled) were captured 16 h post-infection. MRBV-infected iOvCa147-F8 cells appear yellow (GFP and DiI double-positive) whereas MRBV-infected iOvCa147-G4 cells appear teal (GFP and CMAC double-positive). c Double-positive cells were counted for each co-culture concentration and normalized to the total number of iOvCa147-G4 cells (black bars) to determine percent infectivity (100% iOvCa147-F8 served as a control; white bar). (***, p < 0.001, as determined by one-way ANOVA and Dunnett’s posthoc test) d Physical separation of cells was achieved using 0.4-μm Transwell inserts. Media was identical between both upper and lower chambers and 100,000 cells in total were seeded (25,000 cells in the upper chamber and 75,000 cells in the lower chamber). After 24 h, media was changed and cells were infected at 50,000 viral particles (MOI 0.5) of MRBV. After 48 h, viability of the cells in the lower chamber only was measured using CellTiter-Glo® and normalized to uninfected cells. (***, p < 0.001; ****, p < 0.0001, as determined by one-way ANOVA and Tukey’s posthoc test)