FIG 1.

Obatoclax is an effective antiviral against alphaviruses. (A) BHK-21 cells were infected with wild-type SFV, SINV, and CHIKV at an MOI of 0.01 PFU/cell with or without 0.5 μM OLX, which was present throughout the experiment when it was added. Plaque assay titers in cell culture supernatants collected at 16 h p.i. were determined in duplicate (data are means from three independent experiments ± SEMs). (B) BHK-21 cells were infected with wild-type CHIKV at an MOI of 10 PFU/cell for 6 h. Throughout the experiment, OLX was present in a 2-fold dilution series at concentrations ranging from 2 μM to 0.125 μM. Plaque assay titers in cell culture supernatants collected at 6 h p.i. were determined in duplicate (data are means from three independent experiments ± SEMs). Statistical significance was determined using a one-way ANOVA test (****, P < 0.0001). (C) Cell lysates were analyzed by Western blotting for the presence of the indicated CHIKV proteins. Actin was used as a loading control. (D) Total RNA was isolated from parallel wells, Northern blot analysis was done using probes specific to the 3′ UTR of the CHIKV genome, and the viral genomic and subgenomic RNAs were detected. The results are representative of those from two independent experiments.