FIG 4.

Cholesterol efflux is necessary for viral infectivity. (A) Distribution of endosomes and cholesterol at the viral factory in ASFV-infected untreated cells at 16 hpi. Endosomes stained with Rab 7 are shown in green, cholesterol in blue, and viral protein p72 accumulated in the viral replication site in red. N, nucleus. High magnifications of the merged boxed area are shown. The color channels are shown individually in black-and-white pictures. Bar, 10 μm. Bottom left, general view of cholesterol-laden endosomes in uninfected control cells treated with U18666A. Bottom right, in treated and infected cells at 16 hpi, LE devoid of cholesterol were found in close proximity to viral factories (arrows). Bar, 25 μm. (B) Cellular viability at increasing concentrations of U18666A. (C) Infectivity at 6 hpi with U18666A, analyzed by flow cytometry by p30 expression (***, P < 0.001; *, P < 0.05). (D) Early p30 viral protein expression at 6 hpi by WB after U18666A treatment.