FIGURE 1.

Teicoplanin specifically inhibits the entry of Ebola viruses. A, teicoplanin and amiodarone specifically inhibit the entry of Ebola viruses. HEK293T cells were seeded in a 96-well plate, and 24 h later, the cells were incubated with various reagents at 37 °C for 1 h. The cells were then infected with HIV-luc/Zaire EBOV-GP (2014) pseudotyped viruses. After washing and incubation with fresh medium for 48 h, the intracellular luciferase activity was measured. B, chemical structure of teicoplanin. C, HEK293T cells were incubated with teicoplanin at various concentrations at 37 °C for 1 h. The intracellular luciferase activity was measured at 48 h post-infection. The IC₅₀ was calculated using GraphPad Prism software. D, HEK293T cells were incubated with 500 μm teicoplanin at 37 °C for 48 h. Then the cell viability was determined. E, HEK293T cells were infected with HIV-luc/Zaire EBOV-GP (2014) pseudotyped viruses and incubated with 50 μm teicoplanin at 0, 2, 4, and 8 h post-infection. The cells were then incubated for 48 h after which the intracellular luciferase activity was tested. The HIV-luc/VSV-G pseudotyped viruses were used as the controls for specificity. F, HEK293T cells were seeded in a 6-well plate (2 × 10⁵ per well). After 24 h, the cells were incubated with teicoplanin at various concentrations at 37 °C for 1 h and then infected with p24-normalized (100 ng) HIV-luc/Zaire EBOV-GP (2014) or HIV-luc/VSV-G pseudotyped viruses per well. After 6 h, the cells were washed with PBS twice and incubated with 0.25% trypsin at 37 °C for 2 min to remove the viruses that adhered to the cell surfaces. The cells were then collected and lysed, and the intracellular amount of HIV-1 p24 was measured by ELISA. The results are representatives of at least three independent experiments. The bars show the mean values ± S.D. (error bars). The p value was determined by a Student's t test. ***, p < 0.001.