FIG. 4.

Nef enhances the infectivity of virus produced in T cells independent of the presence or absence of MA. GHOST-CXCR4 cells were inoculated with the indicated recombinant viruses produced in Jurkat Tag cells. C-terminally truncated HIV-1 Env was provided in trans in the Jurkat Tag cells to permit only a single round of virus replication. To compensate for the reductions in infectivity caused by the deletions in MA, Δ8-87 and ΔMA/R3 recombinant viruses were used at 2.5- and 5-fold higher concentrations, respectively, than the recombinant viruses containing WT MA. Four days after infection, GFP-positive cells were quantitated by flow cytometry. The percentage of cells within the area defined by the horizontal line in each panel is indicated.