title: Host range of human T-cell leukemia virus type I analyzed by a cell fusion-dependent reporter gene activation assay.
abstract: We constructed a sensitive and quantitative assay system to examine human T-cell leukemia virus type I (HTLV-I) envelope (env) glycoprotein-mediated cell fusion in which T7 RNA polymerase in donor cells coexpressing env glycoproteins activates a reporter gene in recipient cells upon cell fusion. An efficient expression of HTLV-I env glycoproteins (gp46 and gp21) was observed in 293T cells transfected with an expression plasmid by both immunoblot and immunofluorescence analyses. The cells expressing env glycoproteins also exhibited self-fusion. By cocultivating the donor cells with recipient cells transfected with a reporter plasmid possessing the luciferase gene under the T7 promoter, the expression of luciferase was observed upon cell fusion. The activation of the luciferase gene was inhibited by either anti-env neutralizing antibody or synthetic peptide corresponding to env gp21, thus indicating the cell fusion to be specifically mediated by the HTLV-I env glycoproteins expressed in the donor cells. A broad range of cell lines exhibited susceptibility to HTLV-I env-mediated cell fusion by this assay. This newly established assay system may thus provide an efficient way both to study the fusion mechanisms mediated by HTLV-I env glycoproteins and to identify the HTLV-I receptor(s).
authors.affiliation: Faculty of Medicine, Kyushu University, Fukuoka, 812-8582, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Okuma
authors.forename: M
authors.initials: M
authors.lastname: Nakamura
authors.forename: S
authors.initials: S
authors.lastname: Nakano
authors.forename: Y
authors.initials: Y
authors.lastname: Niho
authors.forename: Y
authors.initials: Y
authors.lastname: Matsuura
mesh_terms: D000818:Animals; D002459:Cell Fusion; D002460:Cell Line; D018920:Coculture Techniques; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D015485:Deltaretrovirus Antigens / Q000235:genetics; D004285:Dogs; D004789:Enzyme Activation; D015686:Gene Products, env / Q000737:chemistry / Q000235:genetics*; D017930:Genes, Reporter; D015486:HTLV-I Antigens / Q000235:genetics; D000882:Haplorhini; D015368:Human T-lymphotropic virus 1 / Q000235:genetics*; D006801:Humans; D008156:Luciferases / Q000235:genetics; D051379:Mice; D015493:Paraparesis, Tropical Spastic / Q000235:genetics / Q000821:virology; D011401:Promoter Regions, Genetic; D051381:Rats; D015682:Retroviridae Proteins, Oncogenic / Q000235:genetics; D013552:Swine; D014162:Transfection; D014764:Viral Proteins; D054299:env Gene Products, Human Immunodeficiency Virus