Transient Bcl- x L Overexpression Has Different Effects on Protein Production in Various CHO-Derived Cell Lines

Most Chinese hamster ovary (CHO)-derived cell lines grown in serum- and protein-free suspension cultures for biopharmaceutical manufacturing are particularly sensitive to apoptosis. A wide variety of reports have demonstrated in the past years that overexpression of Bcl-2 significantly delays the onset of apoptosis and may have positive apoptosis-unrelated effects on production cell lines (viability, cell number, productivity). In contrast to Bcl-2, the impact of other anfi-apoptosis determinants of the Bcl-2 family such as Bcl-x L , on key cell characteristics has not yet been evaluated in great detail. However, pioneering work on Bcl-x L has suggested that its expression in a multicistronic expression configuration significantly enhances production of the model product protein SEAP (human placental secreted alkaline phosphatase). Here we show the influence of transient Bcl-x L overexpression on the production of the soluble intracellular adhesion molecule (sICAM) in various CHO-derived production cell lines.