The anti-viral factor APOBEC3G enhances natural killer cell recognition of HIV-infected primary T cells

APOBEC3G (A3G) is an intrinsic antiviral factor that inhibits HIV replication by deaminating cytidine residues to uridine. This causes G-to-A hypermutation in the opposite strand and results in viral inactivation. HIV counteracts A3G through the activity of viral infectivity factor (Vif), which promotes A3G degradation. We report that viral protein R (Vpr), which interacts with a uracil glycosylase, also counteracts A3G by reducing uridine incorporation. However, this process results in activation of the DNA damage response pathway and expression of NK cell activating ligands. Our results reveal that pathogen-induced cytidine deamination and the DNA damage response to viral-mediated repair of uridine incorporation enhance recognition of HIV-infected cells by NK cells.