HIV-1 Pseudovirus Infection Assay

TZM-bl and TZM-bl/FcγRI cells with Tat-regulated luciferase reporter gene expression were used for quantification of viral infection and antibody neutralization as described previously (25 (link), 26 (link), 98 (link)). Briefly, 5 × 10³ TZM-bl or TZM-bl/FcγRI cells were seeded overnight in white-walled 96-well plates at 37°C in a humidified atmosphere with 5% CO₂. The next day, the medium was aspirated without disturbing the cells and mixtures containing HIV-1-pseudotyped lentivirus, DEAE dextran (10 μg/mL), and anti-gp41 antibodies were added to the cells. After incubation for 48 h, cells were lysed and luciferase activity was determined using britelite plus reagent (Perkin Elmer). Relative luminescence unit (RLU) values were quantified using a Synergy HTX multimode reader (BioTek), and percent infection calculated as described previously (34 (link)).