Figure 8.

Effect of DDD85646 on the multiplication of the mammarenaviruses JUNV, TCRV, ML29, and LASV, and the flavivirus ZIKV. (A) A549 cells were infected with the indicated mammarenavirus and treated with DDD85646 (5 or 10 µM) or VC. At the indicated h pi, titers of infectious virus in the cell culture supernatants were determined by the FFA. (B) A549 and BHK21 cells were seeded into M24-well plates at a density of 1 × 10⁵ cells/well and infected with ZIKV (MOI 0.1) for 1 h, then treated with DDD85646 (5 µM). At 24 h pi, supernatants were collected, and virus titers were determined by the FFA. Titers of technical duplicates were log-transformed and plotted as the mean ± SD (error bars). (C) A549 cells were seeded at 4 × 10⁴ cells/well into a 96-well plate, infected with r3LASV/GFP (MOI 0.05), and treated with DDD85646 at the indicated concentrations. At 72 h pi, the cells were fixed, and the numbers of infected cells were determined by immunofluorescence. Numbers of infected cells were normalized to those of vehicle control (VC)-infected cells and expressed as a % of infected cells (viral infection). Cell viability was estimated based on the signal of DAPI staining. Results show the percentage of infected cells (four biological replicates). EC50 and CC50 values were calculated using a variable slope (based on four parameters) model (Prism10). Results show the mean and SD of four replicates. Representative immunofluorescence images of the dose-response assay of selected doses of DDD85646 are shown (D).