Figure 2.

Effects of accessory gene inactivation on HIV-1 replication in HEK 293T/CD4/X4 cells. (A) Schematic representation of experiments designed to quantify and normalize HIV-1 infection in 293T/CD4/X4 cells. The levels of infection estimated by luciferase activity were normalized to the levels of Gag quantified by ELISA. The normalized level of infectivity obtained for wt HIV-1 was set at 1.0, and the infectivity levels for mutants were recalculated relative to that value. The levels of HIV-1 relative infectivity measured in 293T/CD4/X4 cell culture and cell-free infection tests are shown in (B,C), respectively. All data are representative of at least three independent experiments and shown as average values ± standard deviations. *, **, statistically different from the control (wt) by Student’s t-test at p < 0.05 and p < 0.01, respectively.