SAMHD1 and infection: In DC and macrophages cultured in vitro, the degradation of SAMHD1 by SIV-Vpx delivered in target cells by lentivectors prior to infection did not affect HTLV-1 infection, while it efficiently increased that of HIV, suggesting that SAMHD1 is not active against HTLV-1 in DC and macrophages [54].