HD5 and HD6 enhanced HIV infectivity by targeting the virus. Pseudotyped HIV-1JR-FL luciferase reporter virus was incubated with or without HD5 or HD6 (20 μg/ml) at 37°C for 1 hour followed by infection of primary CD4+ T cells (A) or HeLa-CD4-CCR5 cells (B) as described in Materials and Methods. To determine the effect of defensins on the target cell, primary CD4+ T cells or HeLa-CD4-CCR5 cells were incubated with defensins in the presence of FBS for 1 hour, washed, and exposed to pseudotyped HIV-1JR-FL reporter virus for 2 hours. Cells were washed and cultured for 48 hours before measuring luciferase activity. Difference between defensin-treated virions and non-treated control was significant (*p< 0.05) as calculated by two-tailed, paired Student ttest. The value of mean luciferase readout is shown. Data are means ± SD of triplicate samples and represent three independent experiments.