title: Inducible human immunodeficiency virus type 1 packaging cell lines.
abstract: Packaging cell lines are important tools for transferring genes into eukaryotic cells. Human immunodeficiency virus type 1 (HIV-1)-based packaging cell lines are difficult to obtain, in part owing to the problem that some HIV-1 proteins are cytotoxic in a variety of cells. To overcome this, we have developed an HIV-1-based packaging cell line which has an inducible expression system. The tetracycline-inducible expression system was utilized to control the expression of the Rev regulatory protein, which in turn controls the expression of the late proteins including Gag, Pol, and Env. Western blotting (immunoblotting) demonstrated that the expression of p24gag and gp120env from the packaging cells peaked on days 6 and 7 postinduction. Reverse transcriptase activity could be detected by day 4 after induction and also peaked on days 6 and 7. Defective vector virus could be propagated, yielding titers as high as 7 x 10(3) CFU/ml, while replication-competent virus was not detectable at any time. Thus, the cell line should enable the transfer of specific genes into CD4+ cells and should be a useful tool for studying the biology of HIV-1. We have also established an inducible HIV-1 Env-expressing cell line which could be used to propagate HIV-1 vectors that require only Env in trans. The env-minus vector virus titer produced from the Env-expressing cells reached 2 x 10(4) CFU/ml. The inducible HIV-1 Env-expressing cell line should be a useful tool for the study of HIV-1 Env as well.
authors.affiliation: Department of Molecular Genetics and Microbiology, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway, New Jersey 08854-5635, USA.
authors.forename: H
authors.initials: H
authors.lastname: Yu
authors.forename: A B
authors.initials: AB
authors.lastname: Rabson
authors.forename: M
authors.initials: M
authors.lastname: Kaul
authors.forename: Y
authors.initials: Y
authors.lastname: Ron
authors.forename: J P
authors.initials: JP
authors.lastname: Dougherty
mesh_terms: D002460:Cell Line / Q000821:virology*; D002461:Cell Line, Transformed; D002472:Cell Transformation, Viral; D003673:Defective Viruses / Q000235:genetics / Q000502:physiology; D015967:Gene Expression Regulation, Viral; D015686:Gene Products, env / Q000235:genetics; D005822:Genetic Vectors; D015497:HIV-1 / Q000235:genetics / Q000502:physiology*; D006367:HeLa Cells; D006801:Humans; D014779:Virus Replication
chemical_list: D015686:Gene Products, env