Effects of glutamine and asparagine on recombinant antibody production using CHO‐GS cell lines

Abstract

A unique and nontraditional approach using glutamine and asparagine supplements for CHO-glutamine synthetase (GS) cell lines was studied. In our experiments, we found that a decrease in pH and an increase in cell death occurred in production phase of a GS cell line, leading to reduced antibody expression and lower antibody yields. The experimental results and the statistical analysis (ANOVA) indicated that additions of glutamine and asparagine in the basal and feed media were effective to buffer the cell culture pH, reduce lactate generation, maintain a higher cell viability profile, and improve antibody productivity. In bench-top bioreactors, glutamine and asparagine supplementation helped to prevent cell death, improve antibody yield, and reduce base usage. Glutamine is normally excluded from culture media for GS cell lines to prevent the bypass of selection pressure. In this study, however, the addition of glutamine did not affect cell population homogeneity, protein quality, or decrease antibody yield of two GS cell lines.

Cell culture media for recombinant protein expression in Chinese hamster ovary (CHO) cells: History, key components, and optimization strategies

“…For CHO cell lines derived from glutamine synthetase gene knockout hosts (CHO‐GS), media without glutamine is used to select for transfected cells . However, supplementation of glutamine in basal media has been reported to improve cell viability, reduce lactate production and increase antibody productivity, even in the case of CHO‐GS cells which produce abundant glutamine synthetase after transfection . During glutaminolysis, however, glutamine is typically converted to glutamate, thereby also generating free ammonium in the medium .…”

Advanced model‐based control strategies for the intensification of upstream and downstream processing in mAb production

“…Another key amino acid considered in this work is aspartate that is crucial for energy production (through the TCA cycle). When aspartate is exhausted, asparagine can be converted into aspartate through the reaction catalyzed by asparaginase, to compensate for aspartate depletion …”

Responses of CHO-DHFR cells to ratio of asparagine to glutamine in feed media: cell growth, antibody production, metabolic waste, glutamate, and energy metabolism

“…To achieve high-specific growth rate, cell density, and productivity, the culture should be fed with high levels of glutamine or asparagine (Wlaschin and Hu 2006;Jain and Kumar 2008;Lu et al 2013;Sengupta et al 2011). Specifically, glutamine and asparagine are mutually related to each other not only in transportation but also in metabolism (Wipf et al 2002;Huang et al 2007;Kobayashi et al 2015;Xu et al 2014). Glutamine and asparagine could turn into glutamate and aspartate through deamination.…”