Fig. 4.
RO8191 activity against CHIKV-nanoluc infection in Vero-E6 cells. A) Representative scheme of the infection assays. Vero-E6 cells were treated with three-fold serial dilutions of RO8191 at concentrations ranging from 0.02 to 60 µM. CHIKV replication was quantified by measuring nanoluciferase activity (indicated by a black square) and cell viability using an MTT assay (indicated by a gray circle). Values of EC50, CC50, and SI were obtained from the treatment of Vero-E6 cells treated with RO8191. B) Vero-E6 cells were treated with RO8191 for 1 h, then the cells were washed with PBS and infected with CHIKV-nanoluc virus at MOI 0.1 for 1 h. The medium was removed, cells were washed with PBS and fresh medium was added. C) Vero-E6 cells were infected with CHIKV-nanoluc (MOI 0.1) and simultaneously treated with RO8191 for 1 h. Then, cells were washed, and fresh medium was added. D) RO891 and CHIKV-nanoluc at MOI 5 were incubated for 1 h, then the inoculum was added to cells for an extra 1 h, cells were washed, and fresh medium was added. E) Vero-E6 cells were infected with CHIKV-nanoluc (MOI 0.1) for 1 h, cells were washed with PBS and treated with RO8191. Schematic representation of each time-based assay as indicated by Vero-E6 cells (blue bars), RO8191 (gray bars), CHIKV-nanoluc (orange bars), and CHIKV-nanoluc/RO8191 inoculum (blue tube). Mean ± SD values of a minimum of three independent experiments, each measured in triplicate, are represented. (****) P <0.0001, (***) P <0.001 and (*) P <0.05. Images were generated using GraphPad Prism 8 and GIMP 2.1v.