Increasing cell culture productivity by control of programmed cell death (apoptosis)

• Research unit: EU RFP
• Project number: 95.0682

Key words (English)

Mammalian cell cultures; apoptosis; genetic engineering; cell cycle

Alternative project number (English)

EU project number: BIO4CT950207

Research programs (English)

EU-programme: 4. Frame Research Programme - 4.1 Biotechnology

Short description (English)

See abstract

Partners and International Organizations (English)

University of Manchester (UK)

Abstract (English)

In recent years basic research revealed an active, genetically determined process of eukaryotic cells to kill themselves by a mechanism called apoptosis or programmed cell death. Although apoptosis is a vital mechanism for multicellular organisms which is, for example, involved in development and the elaboration and maintenance of the immune system, it is an undesired phenomenon in industrial production processes for the production of protein pharmaceuticals.
Development of serum- and protein-free Chinese hamster ovary (CHO) cell cultures is a high priority for the production of biopharmaceuticals. Protein-free competent CHO cell lines have been previously constructed by two different methods - metabolic engineering with cell cycle regulatory proteins and long-term selective adaptation. Apoptosis was present in both cell lines during protein-free, static batch culture as a result of nutrient deprivation, and glucose deprivation alone was a potent inducer of apoptosis compared to the depletion of other nutrients such as amino acids. By adding back serum to the cultures during bath growth or nutrient deprivation, it was shown that unidentified survival factors in serum can greatly reduce apoptosis in protein-competent cell lines in all phases of the culture. 'Both observations contrast to previous reports for hybridoma cells, in which amino acids were the key determinants of apoptosis and serum had no additional anti-apoptotic effect. Serum's protective effect against CHO cell death in batch culture was multi-faced and complex. These data show that there is much room for improvement of protein-free CHO cell lines despite their adequate growth competence, and new strategies different from those successfully used for hybridomas may be neessary to combat CHO cell apoptosis.

References in databases (English)

Swiss Database: Euro-DB of the
State Secretariat for Education and Research
Hallwylstrasse 4
CH-3003 Berne, Switzerland
Tel. [phone]
Swiss Project-Number: 95.0682