Figure 4

SAMHD1 restricts MPMV and RSV. (A) MDM or (B) PMA-treated THP-1 shControl and THP-1 shSAMHD1 cells were preincubated with Vpx-containing (+Vpx) or control VLP (−Vpx) and infected with control supernatant (mock) or with RSV-GFP or HIV-GFP reporter viruses at a MOI = 1. Reporter gene expression in infected cells was analyzed three days postinfection by flow cytometry. (C) MDM were incubated with Vpx-containing (+Vpx) or control VLP (−Vpx) and then infected with control supernatant (mock) or with RSV reporter virus. Cellular DNA was purified 24 and 48 h postinfection and used to quantify late reverse transcription products by qPCR. AZT was added to one well treated with Vpx-containing VLP prior to infection (AZT). (D) MDM were preincubated for 2 h with Vpx-containing (+Vpx) or control VLP (−Vpx) and not infected (mock) or infected with MPMV-GFP or HIV-GFP at a MOI = 1. The data are shown on the left as a histogram and on the right as a FACS plot. (E) MPMV infection as in (D) but using PMA-differentiated THP-1 shControl and THP-1 shSAMHD1 cells. Reporter gene expression was analyzed three days postinfection by flow cytometry. Reporter gene expression was analyzed as shown for HIV-GFP and MLV-GFP infection of MDM blotted in (D). The data presented are the average of triplicates with error bars indicating the standard deviation. The results of one of three independent experiments are shown.