Vpx is necessary for HIV-2 infection in unstimulated CD4+ T cells. (a) Replication of HIV-2 GL-AN, expressing or not Vpx, in activated CD4+ T cells. Primary activated CD4+ T cells were infected with HIV-2 GL-AN WT and GL-AN ∆Vpx (20–30 ng p27 mL−1). Viral replication was followed as in Figure 1a. Upper panels: Mean ± SD of 6 independent donors. Lower panels: Gag and SAMHD1 expression at day 7 p.i., in one representative donor. ns: non significant (b) Role of Vpx in HIV-2 infection of resting, unstimulated CD4+ T cells. Unstimulated CD4+ T cells were exposed to HIV-2 GL-AN WT and GL-AN ∆Vpx (30 and 90 ng p27 mL−1, respectively) as described in Figure 1c. One day post-infection, the cells were activated with PHA/IL-2. Gag and SAMHD1 levels are shown at different days p.i. Data are Mean ± SEM of 3 independent donors. *: p-value < 0.05.