High level, stable production of recombinant proteins in mammalian cell culture using the herpesvirus VP16 transactivator.

We have engineered mammalian cell lines to produce high levels of heterologous proteins by constructing a cell line that expresses the herpesvirus transactivator, VP16. Subsequent stable transfection with a gene of interest under control of a herpesvirus immediate early promoter led to a rapid isolation of cell lines producing between 1 and 20 micrograms of protein/million cells/24 hours. This high level expression is stable for at least five months.