BIOT 277 |
| We developed a platform for selective and controllable expression of multiple foreign protein types in insect cell culture. Based on the fact that baculovirus cannot replicate in nonpermissive Drosophila melanogaster Schneider line 2 (S2) cells, S2 cells that stably express human erythropoietin (hEPO) under the control of the S2-derived inducible metallothionein (MT) promoter were infected with three types of recombinant baculoviruses, each of which expressed a fluorescent protein (enhanced green fluorescent protein [EGFP], enhanced cyan fluorescent protein [ECFP], or enhanced yellow fluorescent protein [EYFP]) gene under the control of MT promoter. Addition of copper sulfate as an inducer to infected, stably transfected S2 cells resulted in simultaneous expression of hEPO and three fluorescent proteins. Expression profiles and levels of the three induced fluorescent proteins were similar in all single infected cells. Importantly, expression profiles and levels of hEPO were similar in both non-infected and infected cells, indicating that baculovirus infection did not affect the expression of stably introduced foreign genes. Expression of the three fluorescent proteins was able to be selectively regulated by altering combination ratios of the three types of recombinant baculoviruses. Collectively, these data indicate that the baculovirus/stably transfected S2 cell system can be successfully used to express multiple foreign proteins in a controlled and selective manner without the burden of additional selection markers. Such a system would be expected to be attractive as a multiple protein expression platform for engineering metabolic or glycosylation pathways. |
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Poster Session
5:30 PM-7:30 PM, Wednesday, August 22, 2007 BCEC -- Exhibit Hall - B2, Poster
Division of Biochemical Technology |