U373-MAGI-CCR5 cells (1 × 105 cells/well) were plated in triplicate in 24-well plates and transfected with 50 nM siRNAs (CD63, CD4, and ERBB2IP). Controls included cells treated with raltegravir (20 mM), untreated cells or cells treated with virus infection only. Forty eight hours post-transfection, cells were infected with HIV-1 SX (m.o.i. = 0.02). Cell lysates were collected on day 3 post-infection, and Tat-driven β–galactosidase activity was analyzed using the Beta–Glo Assay System (Promega, Madison, WI), and was detected by Dynex MLX Luminometer. *P<0.05, **P<0.01, compared with ERBB2IP control group, respectively.