title: Human immunodeficiency virus type 1 assembly, budding, and cell-cell spread in T cells take place in tetraspanin-enriched plasma membrane domains.
abstract: Human immunodeficiency virus type-1 (HIV-1) egress from infected CD4+ T cells is thought to be via assembly and budding at the plasma membrane and may involve components of the T-cell secretory apparatus, including tetraspanins. However, many studies on HIV-1 assembly have examined the trafficking of viral proteins in isolation, and most have used immortalized epithelial, fibroblastic, or hematopoietic cell lines that may not necessarily reflect natural infection of susceptible T cells. Here we have used immunofluorescence and cryoimmunoelectron microscopy (CEM) to examine protein transport during HIV-1 assembly in productively infected Jurkat CD4+ T cells and primary CD4+ T cells. The HIV-1 envelope glycoprotein (Env) and the core protein (Gag) colocalize strongly with CD63 and CD81 and less strongly with CD9, whereas no colocalization was seen between Env or Gag and the late endosome/lysosomal marker Lamp2. CEM revealed incorporation of CD63 and CD81 but not Lamp2 into virions budding at the plasma membrane, and this was supported by immunoprecipitation studies, confirming that HIV-1 egress in T cells is trafficked via tetraspanin-enriched membrane domains (TEMs) that are distinct from lysosomal compartments. CD63, CD81, and, to a lesser extent, CD9 were recruited to the virological synapse (VS), and antibodies against these tetraspanins reduced VS formation. We propose that HIV-1 promotes virus assembly and cell-cell transfer in T cells by targeting plasma membrane TEMs.
authors.affiliation: The Sir William Dunn School of Pathology, The University of Oxford, Oxford OX1 3RE, United Kingdom. clare.jolly@path.ox.ac.uk
authors.forename: Clare
authors.initials: C
authors.lastname: Jolly
authors.forename: Quentin J
authors.initials: QJ
authors.lastname: Sattentau
mesh_terms: D000199:Actins / Q000378:metabolism; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism*; D015496:CD4-Positive T-Lymphocytes / Q000821:virology*; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D015686:Gene Products, env / Q000235:genetics / Q000378:metabolism; D015683:Gene Products, gag / Q000235:genetics / Q000378:metabolism; D015488:HIV Antigens / Q000235:genetics / Q000378:metabolism; D016655:HIV Core Protein p24 / Q000235:genetics / Q000378:metabolism; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D019169:Jurkat Cells; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D010980:Platelet Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D060225:Tetraspanin 28; D060245:Tetraspanin 29; D060149:Tetraspanin 30; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism; D019065:Virus Assembly; D017201:Virus Shedding; D054301:gag Gene Products, Human Immunodeficiency Virus
chemical_list: D000199:Actins; D015703:Antigens, CD; C554586:CD63 protein, human; C554798:CD81 protein, human; C554869:CD9 protein, human; D015686:Gene Products, env; D015683:Gene Products, gag; D015488:HIV Antigens; D016655:HIV Core Protein p24; D008562:Membrane Glycoproteins; D010980:Platelet Membrane Glycoproteins; D060225:Tetraspanin 28; D060245:Tetraspanin 29; D060149:Tetraspanin 30; D014764:Viral Proteins; D054301:gag Gene Products, Human Immunodeficiency Virus; C054858:p17 protein, Human Immunodeficiency Virus Type 1