Together, these findings indicate that HIV-2 and HIV-1 support similar levels of CD4 T cell depletion <i>in vitro</i> despite HIV-2 Vpx-mediated degradation of the SAMHD1 transcription factor.
Human immunodeficiency virus type 2 (HIV-2) and simian immunodeficiency virus (SIV) encode an accessory protein called viral protein X (Vpx) that promotes proteasomal degradation of SAMHD1, leading to a rapid increase in cellular dNTP concentrations.
SAMHD1 degradation was induced by treating target macrophages with vesicular stomatitis virus glycoprotein-pseudotyped human immunodeficiency virus type 2 (HIV-2) particles containing viral protein X.