Figure 1.

Production and Characterization of EBOVpp. (A) Schematic of EBOVpp with surface-expressing EBOV-GP and an HIV-based luciferase reporter-tagged lentiviral backbone. (B) Infectivity analysis and titration of EBOVpp (10-fold serial dilution) on Huh-7 cells. Luciferase reporter activity was determined at 72 h post-infection to determine viral infectivity. Paraformaldehyde (PFA; 4%) treatment, which fixes the cells and renders them impermeable to virus internalization, was included as a negative control. Data are expressed as mean relative light units (RLU) ± SD from 3 independent experiments. (C) Analysis of EBOV GP expression in supernatant-harvested pseudoparticle preparation by western blotting. Images shown are representative blots from three independent experiments. VSV-G pseudoparticles (VSVpp) are included for comparison and anti-HIV-p17 matrix protein served as control. (D) Transmission electron microscope (TEM) imaging of EBOVpp release from transfected HEK 293FT cells. Representative micrographs from three independent experiments are shown.