FIG. 6.

HIV-1 and HIV-2 isolates are susceptible to Lv2, rescued by the VSV-G envelope, and blocked post-reverse transcription. An array of HIV-2 (A) and HIV-1 (B) isolates was titrated on permissive U87/CD4/CXCR4, H399, and restrictive HeLa/CD4 cells and the FFUs calculated. Fold restriction was calculated by dividing the titer on permissive U87/CD4/CXCR4 cells by the titer on restrictive HeLa/CD4 cells or by permissive H399 cells. (C) VSV-G envelope pseudotypes were prepared with restricted HIV-1 89.6 or nonrestricted NL4.3 gag-pol and titrated on permissive and restrictive cell lines. Transduced eGFP was measured with a fluorescence-activated cell sorter and eGFP-positive cells per ml calculated. (D) Time course of qPCR, first-strand synthesis (ψ), of restricted HIV-1 89.6 and unrestricted HIV-1 NL4.3 on permissive and restrictive cell lines. Zidovudine (AZT) was added at 100 μM as a negative control for reverse transcription.