FIG 2.
(A) Degradation of SAMHD1 by VLPVpx in MDM. Western blot of SAMHD1 expression in MDM treated or not with VLPVpx. (B) Degradation of SAMHD1 by Vpx enhances HIV-1 replication in MDM. MDM previously treated or not with VLPVpx were infected with a VSV-pseudotyped HIV-1 GFP virus and replication was assessed 2 days later by measuring GFP expression. Fivefold change in HIV-1 replication was observed after Vpx-mediated SAMHD1 degradation. Means ± SD from at least six independent donors performed in duplicate are shown. (C) Decreased sensitivity of thymidine analogs NRTI after Vpx-mediated SAMHD1 degradation in MDM. Dose response of NRTI (AZT, d4T, 3TC, ddC, ABC, TFV, and ddI), NNRTI (NVP and EFV), and integrase inhibitor raltegravir as a control. Inhibition of HIV infection was measured as the percentage of GFP+ cells relative to the no-drug condition. Means ± SD from at least three independent donors performed in duplicate are shown. (D) siRNA-mediated knockdown of SAMHD1 in MDM affects AZT antiviral potency. Specific siRNA-mediated inhibition of SAMHD1 mRNA (left) or protein expression (middle) led to an increase in HIV-1 replication (right) compared to mock-transfected MDM or MDM transfected with a control siRNA (siNT). Absence of SAMHD1 correlated with a decreased sensitivity of AZT (1 μM), whereas no changes in NVP sensitivity (5 μM) were observed. Values from a representative donor performed in duplicate are shown.