Figure 1

CD63 facilitates HIV-1 env-mediated entry in human MØs. Human monocyte derived MØ (5 × 10⁵ cells/well) were transfected with 50 nM siRNAs (CD63, CD4, and ERBB2IP). Forty-eight hours post-transfection, cells were transduced with reporter viruses pseudotyped with various viral Env proteins (m.o.i. = 0.02) that contained the HIV-1 NL4-3 envelope-negative luciferase backbone. Cell lysates were collected on day 3 post-transduction, and luciferase activities were analyzed to monitor pseudovirus integration. MLV and VSV were used as controls for the entry step because they enter the cells via receptor-mediated endocytosis. In contrast, pseudoyped viruses coated with R5 (ADA) and R5/X4 dual-tropic (89.6) HIV-1 Env proteins gain entrance into MØs by sequential Env interactions with CD4 and CCR5, resulting in viral-cell membrane fusion. All experiments were performed in quadruplicate. *P < 0.05, compared with ERBB2IP group.