title: Cell-to-cell transfer of HIV-1 via virological synapses leads to endosomal virion maturation that activates viral membrane fusion.
abstract: HIV-1 can infect T cells by cell-free virus or by direct virion transfer between cells through cell contact-induced structures called virological synapses (VS). During VS-mediated infection, virions accumulate within target cell endosomes. We show that after crossing the VS, the transferred virus undergoes both maturation and viral membrane fusion. Following VS transfer, viral membrane fusion occurs with delayed kinetics and transferred virions display reduced sensitivity to patient antisera compared to mature, cell-free virus. Furthermore, particle fusion requires that the transferred virions undergo proteolytic maturation within acceptor cell endosomes, which occurs over several hours. Rapid, live cell confocal microscopy demonstrated that viral fusion can occur in compartments that have moved away from the VS. Thus, HIV particle maturation activates viral fusion in target CD4+ T cell endosomes following transfer across the VS and may represent a pathway by which HIV evades antibody neutralization.
authors.affiliation: Division of Infectious Diseases, Immunology Institute, Mount Sinai School of Medicine, New York, NY 10029, USA.
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Dale
authors.forename: Gregory P
authors.initials: GP
authors.lastname: McNerney
authors.forename: Deanna L
authors.initials: DL
authors.lastname: Thompson
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Hubner
authors.forename: Kevin
authors.initials: K
authors.lastname: de Los Reyes
authors.forename: Frank Y S
authors.initials: FY
authors.lastname: Chuang
authors.forename: Thomas
authors.initials: T
authors.lastname: Huser
authors.forename: Benjamin K
authors.initials: BK
authors.lastname: Chen
mesh_terms: D015496:CD4-Positive T-Lymphocytes / Q000821:virology; D002460:Cell Line; D011992:Endosomes / Q000821:virology*; D015658:HIV Infections / Q000821:virology*; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D013569:Synapses / Q000821:virology*; D014771:Virion / Q000502:physiology*; D053586:Virus Internalization