Animal cell culture for the production of viral vaccines has been performed for more than 50 years, and currently this technology is expanding rapidly to meet present and future demands of the health sector. The development and regulatory approval of continuous cell lines for manufacturing viral vaccines has brought numerous benefits to production processes. However, greater advances in the last decade have been achieved in mammalian cell production of biological therapeutics, including monoclonal antibodies, hormones, growth factors, cytokines and clotting factors. We and others have contributed to these upstream advances by improving cell culture media with the development of animal-free and chemically-defined recombinant protein supplements. The supplements we have developed include recombinant insulin-like growth factor-I (LONG®R3IGF-I), epidermal growth factor (LONG®EGF), transforming growth factor-á (LONG®TGF-á), transferrin (CellPrime™ rTransferrin AF), and albumin (CellPrime™ rAlbumin AF-G or -S). Extensive literature on the action of these bioactive proteins on the cell types relevant to viral vaccine production, including Vero, MDCK, PerC6 ®, and HEK293 cells, strongly supports extending their use to media design for these cell lines. In this report we present our initial results evaluating the effect of protein supplements on cell growth in several of these cell types. Vero, MDCK or HEK293 cells were seeded into a 96-well, scaled-down, cell growth assay system under serum-free conditions. LONG®R3IGF-I, LONG®EGF, CellPrime™ rTransferrin AF, and CellPrime™ rAlbumin AF-G or -S were added either alone or in various combinations and growth over 6 days was measured with a CYQUANT DNA cell-proliferation assay. Results indicated that individual supplements enhanced the growth of some cell types up to 150%; moreover, various combinations of the supplements stimulated growth to a greater extent: Vero (300-500%), MDCK (60-100%), and HEK293 cells (200-240%) above control culture growth. The conclusion is that these animal-free recombinant bioactive protein supplements have the potential to improve dramatically the growth performance of cell culture media in the absence of serum for cell types important in viral vaccine production. Further investigation is required to identify the impact these bioactive proteins may have on viral titres from microcarrier and suspension cultures.
Kenneth Bertram, Marina Ross, Domenica Cavallaro, Larissa Chirkova, and Geoffrey Francis, "APPLICATION OF ANIMAL-FREE RECOMBINANT BIOACTIVE PROTEIN SUPPLEMENTS TO IMPROVE THE PERFORMANCE OF CELL-BASED VIRAL VACCINE PRODUCTION" in "Vaccine Technology III", Eds, ECI Symposium Series, Volume P13 (2010). http://dc.engconfintl.org/vaccine_iii/34