Effect of soluble GAGs on defensin-mediated enhancement of HIV infectivity. Pseudotyped HIV-JR-FL virus was incubated with or without HD5 or HD6 at 20 μg/ml in the absence or presence of heparin (A), chondroitin sulfate (B), and dextran sulfate (C) at various concentrations. After washing off unbound virus, infected cells were cultured for 48 hours before measurement of luciferase activity. Anti-HIV activities of soluble GAGs in the absence of defensins are shown in the left panel. Black bars represent the effect of soluble GAGs on HIV enhancement by HD5 (middle panels) and HD6 (right panels). Open bars (in the middle panel) represent samples in the absence of defensins. In the left panels, the difference between soluble GAG-treated virions and non-treated control is significant (*p< 0.05). In the middle and right panels, the difference between samples with or without defensins is significant (**p< 0.05) except samples treated with heparin at 10 or 100 μg/ml or dextran sulfate at 100 μg/ml in the presence of HD5 (#p > 0.05). After Bonferroni correction, the difference between heparin (1 μg/ml)-treated samples with or without HD5 was not significant (+, p = 0.06). Similarly, the difference between condroitin sulfate (100 μg/ml)-treated samples with or without HD5 was not significant (x, p = 0.14) after Bonferroni correction. Data are means ± SD of triplicate samples and represent three independent experiments.