title: A bioassay for HIV-1 based on Env-CD4 interaction.
abstract: The binding of human immunodeficiency virus type 1 (HIV-1) gp120env to CD4 is the first event leading to infection and represents an important target for possible therapeutic intervention. To provide a tool for screening and quantitation of the effects of drugs inhibiting the Env-CD4 interaction, we developed a simple, fast and quantitative bioassay measuring the fusion between two cell lines generated by stable transfection: one expressing high levels of HIV-1 proteins but no infectious virus (HL2/3), and the other expressing the CD4 receptor and containing an inducible chloramphenicol acetyltransferase (CAT) gene linked to the HIV-1 long terminal repeat (HLCD4-CAT). Upon cocultivation of HL2/3 and HLCD4-CAT cells, efficient cell fusion is observed within 8 h. The efficiency of fusion can be evaluated visually and quantitated by measuring CAT enzyme. This novel bioassay allows testing for drugs capable of interfering with the CD4-Env interaction. HL2/3 cell line secretes gp120env in the medium and can be used for the production of Env protein.
authors.affiliation: National Cancer Institute-Frederick Cancer Research and Development Center, ABL-Basic Research Program, Frederick, MD 21702-1201.
authors.forename: V
authors.initials: V
authors.lastname: Ciminale
authors.forename: B K
authors.initials: BK
authors.lastname: Felber
authors.forename: M
authors.initials: M
authors.lastname: Campbell
authors.forename: G N
authors.initials: GN
authors.lastname: Pavlakis
mesh_terms: D001681:Biological Assay; D015704:CD4 Antigens / Q000378:metabolism* / Q000494:pharmacology; D002459:Cell Fusion / Q000187:drug effects; D002460:Cell Line; D016264:Dextran Sulfate / Q000494:pharmacology; D015726:Giant Cells / Q000166:cytology / Q000187:drug effects; D015699:HIV Envelope Protein gp120 / Q000378:metabolism*; D016325:HIV Long Terminal Repeat; D015497:HIV-1 / Q000502:physiology*; D006367:HeLa Cells; D006801:Humans; D008854:Microscopy, Electron; D014162:Transfection
chemical_list: D015704:CD4 Antigens; D015699:HIV Envelope Protein gp120; D016264:Dextran Sulfate