FIG. 7.

Vpx allows HIV-1 to overcome the type I IFN-induced antiviral state. (A) MDM were induced for 14 h with increasing concentrations of type I IFN, incubated for 2 h with wild-type VLP or medium, and then infected with HIV-1 luciferase reporter virus. One set of wells was left uninfected (mock) to control for background signal. Luciferase activity was measured 4 days postinfection. The results are representative of two independent experiments with MDM from different donors. (B) MDM were induced with 100 U of type I IFN/ml overnight. The cells were then incubated with Δvpx VLP complemented with empty vector (pcDNA), wild-type or Q76A Vpx, or the chimeras R22X or X86R and after 2 h, infected with HIV-1 reporter virus. Luciferase activity was measured 4 days postinfection. The data are presented as the fold enhancement of HIV-1 infection relative to cells incubated with Δvpx VLP. The results are representative of three independent experiments using MDM prepared from PBMC of three different donors.