SAMHD1 and HIV-1 infection: Vpx efficiently degraded endogenous SAMHD1 in DCs at 24 hr post-transduction (Figure1A) and significantly enhanced vesicular stomatitis virus G protein (VSV-G)-pseudotyped single-cycle HIV-1 infection of DCs by 1.5- to 41-fold over a period of 24 to 96 hr post-infection (p <0.05), relative to negative controls (Figure1B).