title: Cell-to-cell fusion, but not virus entry in macrophages by T-cell line tropic HIV-1 strains: a V3 loop-determined restriction.
abstract: T-cell lines chronically infected with laboratory adapted, T-cell tropic HIV-1 strains (RF, LAI, CBL-4, and NY5) induced syncytia after cocultivation with primary macrophages. Such fusion-competent strains, however, replicated inefficiently after cell-free infection of macrophage cultures. Evidence based on proviral DNA synthesis, pseudotype penetration, and a V3 loop mutation revealed that cell-free infection was restricted at a prepenetration stage in entry and controlled by envelope sequences. Our results suggest that primary macrophages are sensitive to cell-to-cell but not to virion-to-cell fusion induced by the envelope glycoproteins of several T-cell tropic HIV-1 strains.
authors.affiliation: Virology Laboratory, Chester Beatty Laboratories, Institute of Cancer Research, London.
authors.forename: G
authors.initials: G
authors.lastname: Simmons
authors.forename: A
authors.initials: A
authors.lastname: McKnight
authors.forename: Y
authors.initials: Y
authors.lastname: Takeuchi
authors.forename: H
authors.initials: H
authors.lastname: Hoshino
authors.forename: P R
authors.initials: PR
authors.lastname: Clapham
mesh_terms: D002450:Cell Communication; D002459:Cell Fusion; D002460:Cell Line; D002474:Cell-Free System; D015686:Gene Products, env / Q000737:chemistry / Q000378:metabolism*; D015726:Giant Cells / Q000166:cytology; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D008264:Macrophages / Q000166:cytology / Q000502:physiology* / Q000821:virology; D013601:T-Lymphocytes / Q000502:physiology* / Q000821:virology; D014771:Virion / Q000502:physiology; D014779:Virus Replication
chemical_list: D015686:Gene Products, env