Fig 6.

The block to infection is reversed by Vpx-mediated degradation of SAMHD1. (A) MDDC were pretreated with MLN4924 or DMSO for 2 h, and then Vpx-containing or control VLP were added and washed away after 24 h. The drug was kept on the cells for 24 h or 48 h or for 24 h and then replaced by fresh medium that was cultured for another 24 h (on/off). SAMHD1 was detected on an immunoblot probed with a monoclonal anti-SAMHD1 antibody. GAPDH was detected as a loading control. (B) Vpx-containing VLP were added to MDM at the indicated time points relative to infection with wild-type or Δvpx SIVmac luciferase reporter virus. Results are shown as luciferase activity of Δvpx SIVmac infection relative to that of WT virus infection. The results shown are representative of 3 independent donors tested. (C) MDDC were infected with HIV.GFP reporter virus containing (HIV X+) or lacking (HIV X−) Vpx. dNs were added to the cells infected with HIV X− and then removed at the indicated time points. After 3 days, the number of infected cells was quantified by flow cytometry. Results shown are averages for triplicate infections with standard deviations. The results shown are representative of 3 independent donors tested.