Figure 1.

R5X4 HIV-1 use CCR5 and CXCR4 on primary macrophages. Monocyte-derived macrophages (MDM) were infected with HIV-1 luciferase-pseudotype viruses (5ng p24 Gag antigen) carrying representative prototype R5X4 envelope glycoproteins, along with control R5 (Bal) and X4 (Tybe) Env-containing viruses. Infections were carried out without entry blocker or in the presence of the CCR5 antagonist Maraviroc (“CXCR4 pathway”; 5μM), CXCR4 antagonist AMD3100 (“CCR5 pathway”; 5μg/ml) or both inhibitors. Three days after infection, cells were lysed with 0.1% Triton, luciferase assay substrate (Promega) was added and luciferase activity (RLUs) was measured using a Dynex Revelation Luminometer. Results represent normalized infection mediated by each coreceptor as a percentage of infection in the absence of antagonists and are means ± sem of infections done using cells from two different donors, each performed in triplicate.