Figure 2.

Inhibition of Ebola virus (EBOV) replication by protein phosphatase 1 (PP1)–targeting compounds. A, Chemical structures of 3 top inhibitory compounds: C17, C31, and C42. B, EBOV inhibition. Vero E6 cell monolayers were pretreated where indicated with 1, 3, 10, and 30 μM concentrations of C17, C31, and C42 for 1 hour before infection with EBOV expressing enhanced green fluorescent protein (EBOV-eGFP; multiplicity of infection, 2 plaque-forming units [PFU]/cell). Following incubation for 1 hour, medium was removed, and fresh medium containing the original concentrations of the compounds was added. For the samples in which no virus was detected, values 2-fold below the limit of detection were assigned. Shown are mean EBOV-eGFP titers (±SD) in the medium, based on triplicate monolayers. C, Vero E6 cell GFP fluorescence and monolayers were photographed 48 hours after infection. Upper panels show noninfected cells treated with C31. D, C31 inhibits EBOV minigenome replication. 293T cells were transfected with monocistronic minigenome, nucleoprotein, VP35, L, VP30, and T7 plasmids. They also were treated with 10 µM C31, 1E7-03, or treated with dimethyl sulfoxide (DMSO) as a vehicle control. At 48 hours after transfection, the minigenome transcriptional activity was analyzed by a luciferase assay. The experiment was repeated 3 times, and a P value of <.05 was considered statistically significant.