A tetracycline regulated recombinant protein production system

摘要

We designed a bicistronic vector enabling high level, regulated production of recombinant protein in mammalian cells. In this vector, a tetracycline-responsive promoter PhCMV~*-1 was used to control the transcription of a bicistronic unit composed of a gene of interest, an internal ribosomal entrysite (IRES) and a chimeric transactivator (tTA). In the absence of tetracycline, the leaky expressed tTA transactivators bind to the PhCMV~*-1 promoter and activate the expression of both the gene of interest and the tTA gene. The tTA transactivators translated from the bicistronic transcript will further activate the transcription of the bicistronic transcript, therefore, the expression system is autocatalytic, Addition of tetracycline prevents the binding of the tTA transactivators to the PhCMV~*-1 promoter, therefore, represses the transcription of the bicistronic transcript. Using this vector, we established a recombinant cell line producing 980 ng #beta#-lactoglobulin/10~6 cells/day with a regulation factor of several thousand folds.