Establishment of a new cell line inducibly expressing HIV-1 protease for performing safe and highly sensitive screening of HIV protease inhibitors

• Published in: Microbes and infection 2006-06, Vol.8 (7), p.1783-1789
• Main Authors: Fuse, Takayuki, Watanabe, Ken, Kitazato, Kaio, Kobayashi, Nobuyuki
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Cell Line; Cytotoxicity; Doxycycline - pharmacology; Drug Evaluation, Preclinical - methods; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation; Green Fluorescent Proteins - genetics; Green Fluorescent Proteins - metabolism; HIV Protease - biosynthesis; HIV Protease - genetics; HIV Protease - metabolism; HIV Protease Inhibitors - pharmacology; HIV-1 protease; Human immunodeficiency virus 1; Humans; Mammalian cell-based system; Microbiology; Miscellaneous; Nelfinavir - pharmacology; Recombinant Fusion Proteins - biosynthesis; Saquinavir - pharmacology; Screening; Sensitivity and Specificity; Tet-off system; Virology
• ISSN: 1286-4579; 1769-714X
• DOI: 10.1016/j.micinf.2006.02.016

The human immunodeficiency virus type 1 (HIV-1) protease (PR) plays an essential role in processing viral polyproteins into mature proteins. As a result, it is a major target for the development of drugs against AIDS. However, due to the rapid emergence of drug-resistant HIV, the development of novel HIV PR inhibitors is urgently needed. We recently established a new cell line E-PR293 which can be used as a safe, convenient and highly efficient assay system to screen HIV-1 PR inhibitors. In the cells, the HIV-1 PR is expressed in a chimeric protein with the green fluorescence protein (GFP). This assay measures the PR activity as a function of either the fluorescence of GFP or the cytotoxic activity of HIV-1 PR which is expressed in the cell. E-PR293 cells were maintained in the presence of doxycycline, which suppresses the expression of HIV-1 PR. The removal of doxycycline induces the expression of HIV-1 PR, which is used to screen HIV-1 PR inhibitors. In E-PR293 cells, the 50% inhibitory concentration of the cytotoxic effects by nelfinavir and saquinavir were as low as nanomolar levels, almost equal to those found in the HIV-infection assay.