Knock-down of SAMHD1 in BMDM increases HIV-1 infection.

<p>(A) The time-line shows the scheme for determining the effect of SAMHD1 knock-down on HIV-1 infection of primary BMDM. Bone marrow cells were differentiated to BMDM in M-CSF and then transfected with siRNA. The cells were then infected with luciferase or GFP reporter virus and the infection was quantified after 4 days. (B) BMDM were transfected with individual SAMHD1 siRNAs (siRNA1, 2 and 4), a pool of 4 SAMHD1 siRNAs (siPool) or control siRNA (siControl). SAMHD1 was then detected on an immunoblot probed with rabbit anti-SAMHD1 antiserum. (C) BMDM were transfected with the pool of four siRNAs targeting mouse SAMHD1 (siPool) or control siRNA (siControl) and then infected with NL-Luc reporter virus 4 days later. After 4 more days, the cells were lysed and luciferase activity was measured. (D, E) BMDM were transfected with anti-SAMHD1 siRNA or control siRNA and, after 4 days, infected with HIV-1-CMV-GFP reporter virus. The cells were analyzed 4 days post-infection by flow cytometry. The result of 3 independent experiments is shown (D). Representative flow cytometry data from a single experiment is shown (E). (F) BMDM were transfected with SAMHD1 siRNA pool or control siRNA. After 6 days, extracts were prepared and the dATP concentration was quantified. These experiments were in triplicate with error bars to indicate the standard deviation of the mean.