title: Rapid complementation assays measuring replicative potential of human immunodeficiency virus type 1 envelope glycoprotein mutants.
abstract: Rapid assays which measure the ability of mutant human immunodeficiency virus type 1 envelope glycoproteins to mediate cell-free and/or cell-to-cell transmission of virus are described. By using these assays, envelope glycoprotein mutants with varying degrees of syncytium-forming ability were tested for ability to complement viral replication in trans. As expected, mutants that dramatically affect association of the gp120-gp41 envelope subunits, CD4 binding, or membrane fusion were unable to form syncytia or to support cell-free or cell-to-cell transmission. Surprisingly, some membrane fusion-defective mutants significantly attenuated in syncytium-forming ability were able to complement viral replication. Conversely, mutations in the carboxyl terminus of gp41 transmembrane glycoprotein, although not affecting syncytium-forming ability, significantly attenuated both forms of virus transmission. These results indicate that syncytium formation is not sufficient for cell-to-cell transmission of human immunodeficiency virus type 1. Furthermore, virus transmission appears to be less sensitive to inhibition of membrane fusion than is syncytium formation.
authors.affiliation: Dana-Farber Cancer Institute, Department of Pathology, Harvard Medical School, Boston, Massachusetts.
authors.forename: E
authors.initials: E
authors.lastname: Helseth
authors.forename: M
authors.initials: M
authors.lastname: Kowalski
authors.forename: D
authors.initials: D
authors.lastname: Gabuzda
authors.forename: U
authors.initials: U
authors.lastname: Olshevsky
authors.forename: W
authors.initials: W
authors.lastname: Haseltine
authors.forename: J
authors.initials: J
authors.lastname: Sodroski
mesh_terms: D000818:Animals; D002460:Cell Line; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D005816:Genetic Complementation Test; D015726:Giant Cells / Q000166:cytology; D006678:HIV / Q000235:genetics* / Q000502:physiology; D006801:Humans; D009154:Mutation; D010957:Plasmids; D014162:Transfection; D014759:Viral Envelope Proteins / Q000235:genetics*; D014779:Virus Replication
chemical_list: D014759:Viral Envelope Proteins; D015500:Chloramphenicol O-Acetyltransferase