FIG. 5.

Target cell surface GAG-dependent effects of polyanions and polycations on HIV-1 infectivity. (A) CHO-K1- and pgsA745-derived target cells were pretreated with the indicated concentrations of Polybrene prior to infection with R7/HXB/GFP or R7/ADA/GFP. (B) Percent GFP positive K1/R5 and 745/R5 target cells that were untreated or treated with 5 μg of Polybrene per ml prior to infection with R7/ADA/GFP. Alternatively, R7/HXB/GFP (C) and R7/ADA/GFP (D) were incubated with the indicated concentrations of heparin prior to infection of CHO-K1- and pgsA745-derived target cells. For each experiment, the number of infected cells was determined by FACS analysis of GFP expression. Relative infectivity values are numbers of infected cells relative to that obtained with untreated cells and viruses.