Benchmarking of commercially available CHO cell culture media for antibody production

Abstract

In this study, eight commercially available, chemically defined Chinese hamster ovary (CHO) cell culture media from different vendors were evaluated in batch culture using an IgG-producing CHO DG44 cell line as a model. Medium adaptation revealed that the occurrence of even small aggregates might be a good indicator of cell growth performance in subsequent high cell density cultures. Batch experiments confirmed that the culture medium has a significant impact on bioprocess performance, but high amino acid concentrations alone were not sufficient to ensure superior cell growth and high antibody production. However, some key amino acids that were limiting in most media could be identified. Unbalanced glucose and amino acids led to high cell-specific lactate and ammonium production rates. In some media, persistently high glucose concentrations probably induced the suppression of respiration and oxidative phosphorylation, known as Crabtree effect, which resulted in high cell-specific glycolysis rates along with a continuous and high lactate production. In additional experiments, two of the eight basal media were supplemented with feeds from two different manufacturers in six combinations, in order to understand the combined impact of media and feeds on cell metabolism in a CHO fed-batch process. Cell growth, nutrient consumption and metabolite production rates, antibody production, and IgG quality were evaluated in detail. Concentrated feed supplements boosted cell concentrations almost threefold and antibody titers up to sevenfold. Depending on the fed-batch strategy, fourfold higher peak cell concentrations and eightfold increased IgG titers (up to 5.8 g/L) were achieved. The glycolytic flux was remarkably similar among the fed-batches; however, substantially different specific lactate production rates were observed in the different media and feed combinations. Further analysis revealed that in addition to the feed additives, the basal medium can make a considerable contribution to the ammonium metabolism of the cells. The glycosylation of the recombinant antibody was influenced by the selection of basal medium and feeds. Differences of up to 50 % in the monogalacto-fucosylated (G1F) and high mannose fraction of the IgG were observed.

Selection of chemically defined media for CHO cell fed-batch culture processes

“…6) due to an imbalance in the feed. Notably, overfeeding of amino acids also occurred when following the protocols prescribed by the suppliers (Reinhart et al 2015). This study demonstrates that CHO cells may display a high variation in specific glucose consumption in different basal medium-feed combinations and during different phases.…”

“…Part of the variation in glucose consumption rate may be caused by uncontrolled glucose levels. The high glucose levels were shown to induce inefficient use of glucose, thus result in higher glucose consumption rate and higher lactate production rate (Reinhart et al 2015). Hence, control of glucose concentration at low values may reduce the variation and keep feeds more balanced throughout the process.…”

“…A feed is generally more concentrated than a basal medium to maximize culture volumetric productivity and product titer. Studies have shown that the composition of culture media and feeds can influence cell growth, protein productivity (Rodrigues et al 2012), gene expression (Zagari et al 2013), product quality (Costa et al 2013; Hossler et al 2009; Reinhart et al 2015), and metabolism of lactate and ammonia (Zagari et al 2013; Kyriakopoulos and Kontoravdi 2014; Luo et al 2012; Ma et al 2009). …”

“…For different medium-feed combinations the richness and composition of the basal media and feeds differ widely. The optimal composition of a basal medium or a feed is highly dependent upon the basic type of CHO cell used, specific characteristics of the generated sub-clones, and type of product (Rodrigues et al 2012; Reinhart et al 2015). Thus, there is no single basal medium or feed suitable for all CHO cultures.…”

“…Rodrigues et al (2012) have compared viable cell concentration and antibody production in seven commercially available media in batch cultures of a CHO-K1 cell line and stressed the importance of selecting the correct medium for the outcome of a process. Reinhart et al (2015) compared cell growth, antibody production, antibody quality on eight chemically defined media for a CHO DG44 cell line in batch, and with a subset of conditions in fed-batch.…”