title: Construction and characterization of a stably transformed HeLa cell line in which the expression of bovine herpesvirus 1 ICP0 (BICP0) is induced by tetracycline.
abstract: To explore the effects BICP0 (a principal transactivator of BHV-1 gene expression) on viral promoter elements, we established a cell line in which the expression of BICP0 is regulated by tetracycline. A hybrid promoter containing reiterated copies of the tet-operator (tet-O) and a minimal herpesviral alpha gene transinducing factor (alpha TIF) responsive element (minimal human cytomegalovirus immediate early promoter) was fused to the BICP0 gene and used to transform a HeLa cell line which expressed a fusion protein consisting of the repressor of the tet-O and the transactivating domain of alpha TIF. Simultaneously, the hygromycin resistance gene was transfected to select cells in media containing either hygromycin alone or both hygromycin and tetracycline. Immunofluorescent assays indicated that BICP0 was synthesised in the transformed cell lines solely upon induction of the gene by tetracycline removal. Only cells which had been kept constantly in medium containing tetracycline were able to synthesise BICP0 upon induction. Induced cell lines transactivated the native BICP0 promoter as well as the herpes simplex virus thymidine kinase promoter and the long terminal repeat sequences of human immunodeficiency virus in a dose dependent manner. These cell lines may help to further explore the functions of BICP0 as well as to investigate the molecular basis of interactions between herpes- and retroviruses.
authors.affiliation: Institute of Virology, University of Zurich, Switzerland.
authors.forename: N A
authors.initials: NA
authors.lastname: Steinmann
authors.forename: R
authors.initials: R
authors.lastname: Nuñez
authors.forename: R
authors.initials: R
authors.lastname: Köppel
authors.forename: M
authors.initials: M
authors.lastname: Ackermann
mesh_terms: D002461:Cell Line, Transformed / Q000187:drug effects / Q000378:metabolism; D004279:DNA, Viral / Q000032:analysis / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D015967:Gene Expression Regulation, Viral / Q000187:drug effects; D005814:Genes, Viral / Q000235:genetics; D016325:HIV Long Terminal Repeat / Q000235:genetics; D006367:HeLa Cells / Q000378:metabolism*; D018259:Herpesvirus 1, Human / Q000201:enzymology / Q000235:genetics; D006801:Humans; D009875:Operator Regions, Genetic / Q000187:drug effects; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic / Q000235:genetics / Q000502:physiology; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology*; D011994:Recombinant Proteins / Q000187:drug effects / Q000235:genetics; D013752:Tetracycline / Q000494:pharmacology*; D013753:Tetracycline Resistance / Q000235:genetics; D013937:Thymidine Kinase / Q000235:genetics; D015534:Trans-Activators / Q000187:drug effects* / Q000235:genetics* / Q000502:physiology; D015533:Transcriptional Activation / Q000235:genetics / Q000502:physiology; D014162:Transfection / Q000235:genetics; D044767:Ubiquitin-Protein Ligases; D014764:Viral Proteins / Q000187:drug effects* / Q000235:genetics* / Q000502:physiology; D015678:Viral Structural Proteins / Q000235:genetics
chemical_list: D004279:DNA, Viral; D011500:Protein Synthesis Inhibitors; D011994:Recombinant Proteins; D015534:Trans-Activators; D014764:Viral Proteins; D015678:Viral Structural Proteins; D044767:Ubiquitin-Protein Ligases; C086729:bICP0 protein, Bovine herpesvirus 1; D013937:Thymidine Kinase; D013752:Tetracycline