pH excursions impact CHO cell culture performance and antibody N-linked glycosylation
- 283 Downloads
pH excursions exist due to frequent base addition and environmental heterogeneity in large-scale bioreactors. Such excursions could lead to suboptimal culture performance. Here we investigated the impact of pH excursions on cell culture performance and N-linked glycosylation for three MAb-producing Chinese hamster ovary cell lines. Frequent pH excursions were introduced by bolus base addition (in total 2–6% of initial volume, fixed bolus addition distributed from day 2 to 8) into small-scale bioreactors. Base addition led to increase in osmolality, pCO2, and lactate production. Lactate production increase was mainly caused by increased culture pH due to base addition, and bolus addition led to higher glucose and lactate metabolic rates than continuous addition. For the three cell lines studied, antibody galactosylation increased with the increase in cultivating pH, correlating to the decrease in cell-specific productivity. Interestingly, pH excursions led to significantly higher galactosylation for one cell line, which also had a higher response to different cultivating pHs. On the other hand, there was no such substantial impact of pH excursions on galactosylation for the other two cell lines, both of which also had minimal response to cultivating pH. This suggests that the impact of pH excursions on antibody N-linked glycosylation is cell line specific and is closely related to cell line response to cultivating pH.
KeywordsHeterogeneity Lactate Mixing Quality attributes Scale-up/scale-down
We thank the Bioprocess Technical Operations group for inoculum and media preparation, Elizabeth Valente, Illysa Hom, Justin Miller, and Michael Rauscher for in-process purification and analytics support, Sonja Battle and Jaymim Patel for N-glycan analysis. We would also like to thank Gregg Nyberg and John Bowers for their constructive feedback.
- 19.Xu S, Gupta B, Hoshan L, Chen H (2015) Rapid early process development enabled by commercial chemically defined media and microbioreactors. Biopharm Int 28:28–33Google Scholar
- 26.Trummer E, Fauland K, Seidinger S, Schriebl K, Lattenmayer C, Kunert R, Vorauer-Uhl K, Weik R, Borth N, Katinger H, Müller D (2006) Process parameter shifting: part I. Effect of DOT, pH, and temperature on the performance of Epo-Fc expressing CHO cells cultivated in controlled batch bioreactors. Biotechnol Bioeng 94:1033–1044CrossRefPubMedGoogle Scholar
- 31.Schilling BM, Abu-Absi S, Thompson P (2012) Metabolic process engineering—a novel technology platform applied to industrial cell culture production processes. Bioprocess Int 10:42–49Google Scholar
- 32.Xu S, Abu-Absi S, Itzcoatl P, Maranga L (2014) Scale dependence of lactate metabolism in mammalian cell cultures. ACS Spring MeetGoogle Scholar
- 44.Zalai D, Hever H, Lovasz K, Molnar D, Wechselberger P, Hofer A, Parta L, Putics A, Herwig C (2016) A control strategy to investigate the relationship between specific productivity and high-mannose glycoforms in CHO cells. Appl Microbiol Biotechnol 100:7011–7024CrossRefPubMedPubMedCentralGoogle Scholar
- 46.Sieck JB, Cordes T, Budach WE, Rhiel MH, Suemeghy Z, Leist C, Villiger TK, Morbidelli M, Soos M (2013) Development of a scale-down model of hydrodynamic stress to study the performance of an industrial CHO cell line under simulated production scale bioreactor conditions. J Biotechnol 164:41–49CrossRefPubMedGoogle Scholar