Figure 5

Wild type SAMHD1 as well as SAMHD1 _K11A inhibit HIV-1 infection in cell lines and primary monocyte derived macrophages. A) U937 cells transduced with lentiviral vectors expressing wild type or K11A mutant SAMHD1, or mCherry respectively, were differentiated with 100 ng/ml PMA for 2 days and then infected with an HIV-1 YFP reporter vector at different doses. Infected cells were enumerated by flow cytometry 48 h after infection. A representative of at least three independent experiments is shown. B) A parallel sample to A) was used for western blotting using a SAMHD1 specific antibody. Tubulin served as a loading control. C) Monocyte-derived macrophages were transduced with lentiviral vectors encoding HA-tagged SAMHD1_WT or SAMHD1_K11A in the presence or absence of virus like particles delivering Vpx_MAC and cells were used for western blotting using anti-HA, anti-SAMHD1 as well as anti-tubulin antibodies. Cells transduced with a lentivirus vector expressing E2-Crimson (E2C) served as a control. D) A parallel sample of C) was used to test the infectivity of an HIV-1 GFP reporter virus which was measured 48 h post infection by flow cytometry. Infectious titers (i.u./ml) were calculated from three independent viral doses. Numbers above bars present fold changes compared to the E2C control.