title: Selection and characterization of a replication-competent human immunodeficiency virus type 1 variant encoding C-terminally truncated env.
abstract: A long cytoplasmic C-terminus (Env-CT) on the human immunodeficiency virus type 1 (HIV-1) Env protein is a highly conserved feature in vivo. Mutant HIV lacking the Env-CT cannot replicate in PBMCs and in the majority of T cell lines (nonpermissive cells, e.g., H9 cells) in vitro. We report here that a single amino acid change (N750K) in the context of the mutant virus pNL-Tr752 lacking 104 C-terminal Env amino acids gives rise to a virus variant pNL-Tr752(N750K), which can now replicate in nonpermissive H9 cells and, albeit to a lower extent, in PBMCs. We have analyzed the properties of replication-competent pNL-Tr752(N750K) in comparison to its defective counterpart pNL-Tr752 and to wild-type virus in H9 cells. In all cases, the respective glycoproteins were functional in inducing membrane fusion and were incorporated into particles. In comparison to pNL-Tr752 and pNL-Wt, pNL-Tr752(N750K) glycoprotein exhibited increased fusion induction and 2- to 3-fold increased incorporation into particles, properties that may contribute to the observed replication competence.
authors.affiliation: Forschungsschwerpunkt Infektion und Krebs, F020, Deutsches Krebsforschungszentrum, 69120 Heidelberg, Germany.
authors.forename: Denise
authors.initials: D
authors.lastname: Holtkotte
authors.forename: Tanya
authors.initials: T
authors.lastname: Pfeiffer
authors.forename: Thorsten
authors.initials: T
authors.lastname: Pisch
authors.forename: Valerie
authors.initials: V
authors.lastname: Bosch
mesh_terms: D002460:Cell Line; D004279:DNA, Viral / Q000235:genetics; D017353:Gene Deletion; D015752:Genes, env / Q000235:genetics*; D015497:HIV-1 / Q000235:genetics* / Q000502:physiology; D006801:Humans; D014779:Virus Replication
chemical_list: D004279:DNA, Viral