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. Author manuscript; available in PMC: 2013 Mar 13.
Published in final edited form as: Nature. 2011 May 25;474(7353):654–657. doi: 10.1038/nature10117

Figure 2. SAMHD1 restricts HIV-1 infection in THP-1 cells.

Figure 2

THP-1 cells were engineered to stably express shRNA 3 (3) or shRNA 4 (4) specifically targeting SAMHD1 (THP-1-shSAMHD1) or scrambled shRNA (THP-1-scr). a, THP-1-shSAMHD1 and THP-1-scr cells were infected with 50 ng of HIV-LUC-G. Luciferase activity was measured 24 h after infection and normalized for protein concentration in analysed samples. Results are expressed as fold increase of luciferase activity in THP-1-shSAMHD1 over THP-1-scr cells. N.I., non-infected. b, THP-1-shSAMHD1 and THP-1-scr cells were treated with VLP-Vpx before infection with 50 ng of HIV-LUC-G. Luciferase activity was measured as in a. Results are expressed as fold increase of luciferase activity in VLP-Vpx-treated over untreated cells. c, Mutants of Flag- and HA-tagged SAMHD1 (SAMHD1-F/H) were generated that are either shSAMHD1-resistant (SAMHD1-R) or mutated in the HD domain (SAMHD1(HD/AA)). These mutants were introduced in an MLV expression vector. Asterisk indicates synonymous mutation. d, THP-1-shSAMHD1 cells were transduced with SAMHD1-R for 48 h or left untreated, differentiated and infected with 100 ng of HIV-LUC-G. Luciferase activity was measured and expressed as in a. e, U937 myeloid cells were transduced with SAMHD1-F/H or SAMHD1(HD/AA) for 24 h. After a further 16-h differentiation step, cells were infected with 10 ng of HIV-LUC-G. Luciferase activity was measured as in a. Results are expressed as fold increase luciferase activity in transduced over parental U937 cells. f, Total viral DNA was quantified by quantitative PCR in THP-1-shSAMHD1 and THP-1-scr cells 24 h after infection with HIV-LUC-G or heat-inactivated virus (56 °C). Results are expressed as per cent maximum signal intensity. All graphs show mean ± standard deviation from a representative experiment (n = 5).