Cell Engineering and Cultivation of Chinese Hamster Ovary (CHO) Cells

Abstract

Mammalian cell lines are important host cells for the industrial production of pharmaceutical proteins owing to their capacity for correct folding, assembly and post-translational modification. In particular, Chinese hamster ovary (CHO) cells are the most dependable host cells for the industrial production of therapeutic proteins. Growing demand for therapeutic proteins promotes the development of technologies for high quality and productivity in CHO expression systems. The following are fundamentally important for effective production. 1) Construction of cultivation process. The CHO-based cultivation process is well established and is a general platform of therapeutic antibody production. The cost of therapeutic protein production using CHO cells is equivalent to that using microbial culture. 2) Cell line development. Recent developments in omics technologies have been essential for the development of rational methods of constructing a cell line. 3) Cell engineering for post-translational steps. Improvement of secretion, folding and glycosylaiton is an important key issue for mammalian cell production systems. This review provides an overview of the industrial production of therapeutic proteins using a CHO cell expression system.

Improved antibody production in Chinese hamster ovary cells by ATF4 overexpression

“…First, the conventional methods focused on process and reactor design and media formulation development (Wurm 2004) to increase viable cell concentration. Second, gene amplification methodologies, including the construction of gene-amplified cell lines, target integration into hot spots on CHO chromosomes, or the use of strong promoters and/or stable elements in vectors, can increase yield by increasing mRNA translation (Barnes and Dickson 2006;Omasa 2002;Omasa et al 2010;Park et al 2010). Third, protein folding, post-translational modification and secretion have been improved, which is of particular importance because the amount of secreted heterologous protein does not always increase proportionally with gene copy number (Parekh et al 1995;Yoshikawa et al 2000), mRNA (Barnes et al 2004) or even the amount of intracellular heterologous protein (Schroder and Friedl 1997).…”

Promoter methylation and transgene copy numbers predict unstable protein production in recombinant chinese hamster ovary cell lines

“…Today, many of these proteins are produced recombinantly in mammalian cell culture, by transient or stable transfection with a DNA expression vector. Stably transfected cell lines derived from Chinese hamster ovary (CHO), NS0, Sp2/0, or other mammalian cells are widely used to produce large amounts of therapeutic proteins, such as immunoglobulins (Durocher and Butler, 2009;Omasa et al, 2010;Wurm, 2004).…”

Enhancement of sialylation on humanized IgG-like bispecific antibody by overexpression of α2,6-sialyltransferase derived from Chinese hamster ovary cells

“…The heterogeneity of the oligosaccharide structure should be regulated for industrial therapeutic antibody production because that results in an unstable potency of therapeutic antibodies. At present, the Chinese hamster ovary (CHO) cell is the most important "industrial mammalian host cell line" because of its wide usage for GMP-certified recombinant protein production, the development of industrial serum-free media, and the achievement of the production of more than 10 g/L recombinant antibody (Butler 2005;Omasa et al 2010a). In general, the oligosaccharide heterogeneity of recombinant glycoproteins produced from CHO cells is largely affected by the environmental condition of its cell culture (Andersen and Goochee 1994;Yang and Butler 2002;Hong et al 2010).…”