FIG. 4.

Effects of the microtubule-disrupting agent nocodazole and the microtubule-stabilizing agent taxol on Ebola virus GP-pseudotyped entry and fusion. (A) Effects of nocodazole and taxol on the microtubule network present in HeLa cells. Cells were treated with nocodazole (10 μM) or taxol (20 μM) for 1 h at 37°C followed by immunostaining with anti-α-tubulin antibody. (B and C) HeLa or HeLa-CD4 cells were pretreated with the indicated concentrations of nocodazole (B) or taxol (C) at 37°C for 30 min and incubated with each of the pseudotyped virions in the continued presence of each drug at 37°C for 3 h. Values in panels B and C are the levels of fusion relative to that in untreated controls. (D) Effect of taxol (Tx) on entry and fusion kinetics. Cells were pretreated with 10 μM taxol or a dimethyl sulfoxide control for 1 h at 4°C prior to assessment of entry and fusion kinetics with the indicated virion pseudotypes. Values represent the extent of fusion relative to the maximum level of fusion obtained.