FIG 2.
Effects on pseudovirus infectivity of variation in glycoprotein expression levels for different filovirus strains as well as for HIV Env. (A to D) 293T cells were cotransfected with 500 ng of plasmid encoding HIVΔEnv (SG3) backbone plus plasmids encoding GP1,2 from Sudan ebolavirus (A), Marburg virus (B), Lloviu cuevavirus (C), or HIV Env (SF162) (D). The amounts of glycoprotein-encoding DNA plasmids varied from 4 μg to 4 ng, and infectivity was measured at 48 h posttransfection by luciferase assay and converted to PFU/ml as described in Materials and Methods. Results reported are representative of those obtained in three separate experiments and are the means and standard deviations for samples run in triplicate.