A HUMAN CELL-LINE CONSTITUTIVELY EXPRESSING HTV-1 GAG AND GAG-POL GENE-PRODUCTS

A human cell line constitutively expressing the HIV-1 gag and pol gene s products was established. The cell line was established by stably tr ansfecting 293 cells with a plasmid construct that expresses the HIV G ag and Pol and can confer the transfectants resistant to mycophenolic acid. Particles generated from transient expression of the plasmid con struct were noninfectious when pseudotyped with HIV envelope or with a mphotropic murine leukemia virus envelope proteins. However, virus-lik e Gag particles produced by the stable cell line were appropriately pr ocessed, exhibited a wild-type retrovirus particle density, and posses sed significant reverse-transcriptase (RT) activities. Continuous pass age of the cell line either in the presence or absence of mycophenolic acid had no major effects on the Gag processing efficiency, particle assembly, or RT activity release. It was also demonstrated that the pr oteolytic processing of the virus-like particles released from the cel l line was inhibited by an HIV protease inhibitor, saquinavir. The est ablishment of a stable cell line producing noninfectious but proteolyt ically processed HIV Gag particles offers a safe, convenient tool for biochemical and immunological analysis of virus-like particle assembly and is very useful for the development of anti-HIV protease drugs. J. Med. Virol. 57:77-24, 9999. (C) 1999 Wiley-Liss, Inc.