title: Directional budding of human immunodeficiency virus from monocytes.
abstract: Time-lapse cinematography revealed that activated human immunodeficiency virus (HIV)-infected monocytes crawl along surfaces, putting forward a leading pseudopod. Scanning electron micrographs showed monocyte pseudopods associated with spherical structures the size of HIV virions, and transmission electron micrographs revealed HIV virions budding from pseudopods. Filamentous actin (F-actin) was localized by electron microscopy in the pseudopod by heavy meromyosin decoration. Colocalization of F-actin and p24 viral antigen by light microscopy immunofluorescence indicated that F-actin and virus were present on the same pseudopod. These observations indicate that monocytes produce virus from a leading pseudopod. We suggest that HIV secretion at the leading edges of donor monocytes/macrophages may be an efficient way for HIV to infect target cells.
authors.affiliation: Department of General Physiology and Biochemistry, University of Milan, Italy.
authors.forename: M E
authors.initials: ME
authors.lastname: Perotti
authors.forename: X
authors.initials: X
authors.lastname: Tan
authors.forename: D M
authors.initials: DM
authors.lastname: Phillips
mesh_terms: D000199:Actins / Q000032:analysis; D002465:Cell Movement; D016655:HIV Core Protein p24 / Q000032:analysis; D015497:HIV-1 / Q000502:physiology* / Q000648:ultrastructure*; D006801:Humans; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D009000:Monocytes / Q000502:physiology* / Q000648:ultrastructure / Q000821:virology*; D009040:Motion Pictures; D013997:Time Factors
chemical_list: D000199:Actins; D016655:HIV Core Protein p24