title: Inhibition of endosomal/lysosomal degradation increases the infectivity of human immunodeficiency virus.
abstract: Productive entry of human immunodeficiency virus type 1 (HIV-1) into a host cell is believed to proceed via fusion of the viral envelope with the host cell's plasma membrane. Interestingly, the majority of HIV-1 particles that bind to the cell surface are taken up by the host cell via endocytosis; however, this mode of internalization generally does not result in infection. Presumably, virus particles remain trapped in the endocytic pathway and are eventually degraded. Here, we demonstrate that treatment of cells with various pharmacological agents known to elevate the pH of endosomes and lysosomes allows HIV-1 to efficiently enter and infect the host cell. Pretreatment of cells with bafilomycin A1 results in up to a 50-fold increase in the infectivity of HIV-1(SF2). Similarly, pretreatment of target cells with amantadine, concanamycin A, concanamycin B, chloroquine, and ammonium chloride resulted in increases in HIV-1 infectivity ranging between 2- and 15-fold. Analysis of receptor and coreceptor expression, HIV-long terminal repeat (LTR) transactivation, and transduction with amphotropic-pseudotyped murine leukemia virus (MLV)-based vectors suggests that the increase in infectivity is not artifactual. The increased infectivity under these conditions appears to be due to the ability of HIV-1 and MLV particles to enter via the endocytic pathway when spared from degradation in the late endosomes and lysosomes. These results could have significant implications for the administration of current and future lysosmotropic agents to patients with HIV disease.
authors.affiliation: Department of Internal Medicine, Division of Infectious Diseases, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390, USA.
authors.forename: Brenda L
authors.initials: BL
authors.lastname: Fredericksen
authors.forename: Bangdong L
authors.initials: BL
authors.lastname: Wei
authors.forename: Jian
authors.initials: J
authors.lastname: Yao
authors.forename: Tianci
authors.initials: T
authors.lastname: Luo
authors.forename: J Victor
authors.initials: JV
authors.lastname: Garcia
mesh_terms: D000547:Amantadine / Q000494:pharmacology; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002460:Cell Line; D002738:Chloroquine / Q000494:pharmacology; D004705:Endocytosis / Q000187:drug effects*; D011992:Endosomes / Q000378:metabolism* / Q000821:virology; D016325:HIV Long Terminal Repeat; D015497:HIV-1 / Q000187:drug effects / Q000235:genetics / Q000472:pathogenicity*; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009052:Leukemia Virus, Murine / Q000235:genetics; D008247:Lysosomes / Q000378:metabolism* / Q000821:virology; D018942:Macrolides; D051379:Mice; D014161:Transduction, Genetic
chemical_list: D000900:Anti-Bacterial Agents; D018942:Macrolides; D002738:Chloroquine; C040929:bafilomycin A1; D000547:Amantadine