Figure 3

Vpu S52A does not impair HIV-1 release from P4-CCR5 cells. (A) Western blot analysis of viral gene expression in lysates of transfected 293T cells. (B) Viral particle release by P4-CCR5 cells transfected with the indicated X4 and R5 HIV-1 NL4-3 proviral constructs. P4-CCR5 cells were transfected with 0.1 μg proviral DNA in sextuplicates and p24 in the culture supernatants was quantified by p24 ELISA three days later. Measurement of the β-Gal activities in the cell lysates verified similar transfection efficiencies (not shown). Values give averages +/- SD from two independent experiments with sextuplicate transfections and represent percentages compared to NL4-3 wildtype transfected cells (100%). (C) P4-CCR5 indicator cells were infected in triplicate with virus stocks containing 1 ng p24 antigen derived from 293T cells transfected with the indicated proviral constructs and β-Gal activity was determined three days later. Shown are average values +/- SD from two independent experiments with triplicate infections of two independent virus stocks. Infectivity is given as percentage compared to infectivity of NL4-3 wildtype infected cells (100%). Abbreviations, N-, Nef-defective; U-, Vpu-defective; S52A, VpuS52A.