Cell growth in conventional mammalian cells cultures used in production eventually leads to nutrient depletion, oxygen deficiency and accumulation of toxic compounds in the medium. Cell death and decreased product quality is the undesired consequences. In the native environment cells proliferate until an organ has reached its mature size, yet secretion of cellular products can go without further growth. The natural situation in biotechnologically relevant cell lines (CHO and BHK) was mimicked by the initially allowing rapid cell growth that is followed by an extended production phase during which proliferation is reduced.
Achievements:
-Establishment of proliferation controlled CHO and BHK-21 cell lines and cell lines currently used for the production of several pharmaceutically relevant proteins (e.g. Erythropoietin, Factor VII). Control of cell proliferation by using tumor suppressor genes or cell cycle controlling genes.
-Establishment of the physiological characteristics of stable proliferation controlled cell lines and their product formation characteristics.
-Overall improvement of product expression in proliferation reduced cell lines as compared to cells with unrestricted cell growth. Improvement of the physiological status of the cells.
-Establishment of process configuration and operational strategies to achieve good levels of performance with proliferation-controlled production cell lines.
-Consistent glycosylation patterns during unrestricted and restricted cell growth.