“…In cell culture, vif-defective (vif Ϫ ) HIV-1 is able to replicate in some T-lymphoblastoid cell lines termed permissive (CEM-SS, SupT1, C8166, and Jurkat) whereas Vif is required in other cell lines, such as H9 or MT-2, termed nonpermissive (18,22,37,64,66,69). It is generally accepted that Vif acts in late steps of the viral life cycle to ensure production of infectious virions (3,12,53,56,61,64,69). vif Ϫ HIV-1 is impaired in endogenous reverse transcription and in its ability to form proviral DNA in newly infected cells (4,25,59,64,69).…”