Rapid complementation assays measuring replicative potential of human immunodeficiency virus type 1 envelope glycoprotein mutants.
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.
Helseth
E
E
Dana-Farber Cancer Institute, Department of Pathology, Harvard Medical School, Boston, Massachusetts.
Kowalski
M
M
Gabuzda
D
D
Olshevsky
U
U
Haseltine
W
W
Sodroski
J
J
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
D014759:Viral Envelope Proteins; D015500:Chloramphenicol O-Acetyltransferase