TY - JOUR AU - Mahboubi, Bijan AU - Gavegnano, Christina AU - Kim, Dong-Hyun AU - Schinazi, Raymond F. AU - Kim, Baek PY - 2018 DA - 2018/10/13 TI - Host SAMHD1 protein restricts endogenous reverse transcription of HIV-1 in nondividing macrophages JO - Retrovirology SP - 69 VL - 15 IS - 1 AB - SAM domain and HD domain containing protein 1 (SAMHD1) is a host anti-HIV-1 restriction factor known to suppress viral reverse transcription in nondividing myeloid cells by its dNTP triphosphorylase activity that depletes cellular dNTPs. However, HIV-2 and some SIV strains rapidly replicate in macrophages due to their accessory protein, viral protein X (Vpx), which proteosomally degrades SAMHD1 and elevates dNTP levels. Endogenous reverse transcription (ERT) of retroviruses is the extra-cellular reverse transcription step that partially synthesizes proviral DNAs within cell-free viral particles before the viruses infect new cells. ERT activity utilizes dNTPs co-packaged during budding from the virus-producing cells, and high ERT activity is known to enhance HIV-1 infectivity in nondividing cells. Here, since Vpx elevates cellular dNTP levels in macrophages, we hypothesize that HIV-2 should contain higher ERT activity than HIV-1 in macrophages, and that the Vpx-mediated dNTP elevation should enhance both ERT activity and infectivity of HIV-1 particles produced in macrophages. SN - 1742-4690 UR - https://doi.org/10.1186/s12977-018-0452-z DO - 10.1186/s12977-018-0452-z ID - Mahboubi2018 ER -