RESUMEN
The premature termination of high producer clones, which will be killed due to cell proliferation and proteins production antagonism, is one of the basic drawback in recombinant proteins technology. Furtheremore, it is supposed some toxic proteins like interferon which we intended to clone and express, inhibit host cells' proliferation. So, it is necessary to tightly control IFN-gamma production during growing and selecting of highly producing clones. In the present study, we constructed an expression vector, pMPGB43P2[6]K containing the cumate-regulatable expression cassette to high production of human IFN-gamma in Chinese Hamster Ovary- Cumate Transactivator [CHO-CTA]. The clones were selected in the cumate and without cumate treated medium. Our results showed induced IFN-lamda expression level was about 5 of magnitude higher than the constitive transgenic system. Application of cumate-regulatable expression cassette, which can be switch off and on by cumate, is useful to production of high producer clones and express toxic proteins in animal cells