FIG. 2.
Infectivity and Env processing of HIV-2KR.X7/HIV-1 V3 chimeras. (A) Proviral constructs were transfected into 293T cells to generate infectious virus stocks. Virus infectivity was assessed by luciferase production (RLU) in the TZM-bl single-cycle entry assay (96, 97). Luciferase readout was normalized by HIV-2 p27 antigen quantification. Data are presented as the mean and standard deviation of three independent experiments. Env-deficient HIV-2 was tested as a negative control. (B) Virus stocks were prepared by 293T transfection. At 48 h after transfection, virus was harvested from culture supernatants, pelleted, solubilized, and subjected to sodium dodecyl sulfate-gel electrophoresis and immunoblotting with a guinea pig anti-HIV-2 gp120 polyclonal antibody. Envelope-deficient HIV-2 was included as a negative control. The positions of the gp160 precursor glycoprotein and processed gp120 are identified by arrows.