FIG 3.

BST2 expression inhibits HIV-1 release in macrophages. MDMs from different donors transfected with control siRNA (siCtrl) or siRNA targeting BST2 (siBST2) were infected with VSV-G-pseudotyped WT NL4-3 (WT) or Vpu-deficient NL4-3 (Udel) HIV-1. (A) At 5 days postinfection, Western blot analysis of HIV-1-infected MDMs from donor 5 was performed using anti-BST2, anti-CAp24, anti-Vpu, and anti-actin antibodies. (B and C) CAp24 present within the cells (cell-associated CAp24) and CAp24 released into the supernatant (released CAp24) of infected cells were quantified by an ELISA. Data normalized to the value for WT NL4-3-infected siCtrl cells in panel B and raw data are presented in panel C. Bars represent the means ± SEM from replicates done on the same donor. (D) HIV-1 release was determined as the ratio of released CAp24 to total CAp24 production (cell-associated CAp24 plus released CAp24). Data were normalized to the value for WT NL4-3-infected siCtrl cells. Statistical significance was determined using one-way ANOVA combined with Holm-Sidak’s post hoc test (means ± SEM; n = 3 donors). **, P ≤ 0.01; ***, P ≤ 0.001; ns, not significant.