FIG 3.

G₂/M arrest stimulates VSV-ΔM51 replication under lower-MOI conditions. (A) Light and epifluorescence microscopy of Suit2 cells mock treated (Ctrl) or treated with paclitaxel (3 μM), VSV-ΔM51 (MOI of 0.01 or 0.1 PFU/ml [the MOI was calculated based on virus titration on BHK-21 cells]), or both for 72 h p.i. (B) Suit2 cells were seeded and washed with PBS before infection with 100 μl of VSV-ΔM51 at different MOIs (0.001, 0.1, or 10 PFU/cell [the MOI was calculated based on virus titration on BHK-21 cells]) for 1 h in medium without FBS. Cells were then washed and incubated for 72 h with 100 μl of medium (5% FBS) containing or not 500 nM paclitaxel. The measurements of GFP fluorescence were performed at the indicated time points. The data show results of one experiment representative of two, each performed in quadruplicates, and data represent the means and SD of the means. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001; ns, nonsignificant. The significance of the data was determined using two-way ANOVA with a Tukey posttest at a 95% confidence interval for comparison between VSV plus paclitaxel and VSV alone. (C) De novo virion production in the supernatant of Suit2 cells infected with VSV-ΔM51, incubated for 72 h, and treated or not treated with 3 μM paclitaxel (PAC). Virion production yield was measured by titrating the supernatants on BHK-21 cells using a standard plaque assay. The experiment was performed two independent times, and data are presented as the means and SD of the means. *, P < 0.05; ***, P < 0.001; ns, nonsignificant. The significance of the data was determined by using the two-tailed unpaired t test.