FIG. 3.
The lower infectivity and higher responsiveness to BFLA-1 of HIV-1SF2 map to its envelope. (A) Diagram depicting the genomic structure of HIV-1 and the chimeric viruses used for this analysis. (B) Infectivities of wild-type and chimeric viruses relative to HIV-1SF2 (set as 1). Infections with each wild-type virus and the individual chimeras were performed twice in triplicate using P4-R5 Magi cells. (C) Top: effect of BFLA-1 on the infectivities of HIV-1SF2, HIV-1NL4-3, and two chimeras. The infectivity of each virus in the absence of BFLA-1 was set as 1 for comparison purposes. Bottom: similar levels of Env incorporation into virions were confirmed by Western blot analysis of HIV-1 gp120 in the four virus preparations. For both panels B and C, absolute infectivities expressed as IU/ng p24Gag for each isolate are: SF2, 13; NL4-3, 350; SF2BsENL4-3, 9; NL4-3BsESF2, 273; SF2SXNL4-3, 260; NL4-3SXSF2, 12; SF2DXNL4-3, 191; SF2SMNL4-3, 33; SF2MXNL4-3, 45; NL4-3BaXSF2, 260.