Comprehensive assessment of host cell protein expression after extended culture and bioreactor production of CHO cell lines
Date
2022-05-04
Journal Title
Journal ISSN
Volume Title
Publisher
Biotechnology and Bioengineering
Abstract
The biomanufacturing industry is advancing toward continuous processes that will involve longer culture durations and older cell ages. These upstream trends may bring unforeseen challenges for downstream purification due to fluctuations in host cell protein (HCP) levels. To understand the extent of HCP expression instability exhibited by Chinese hamster ovary (CHO) cells over these time scales, an industry-wide consortium collaborated to develop a study to characterize age-dependent changes in HCP levels across 30, 60, and 90 cell doublings, representing a period of approximately 60 days. A monoclonal antibody (mAb)-producing cell line with bulk productivity up to 3 g/L in a bioreactor was aged in parallel with its parental CHO-K1 host. Subsequently, both cell types at each age were cultivated in an automated bioreactor system to generate harvested cell culture fluid (HCCF) for HCP analysis. More than 1500 HCPs were quantified using complementary proteomic techniques, two-dimensional electrophoresis (2DE) and liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). While up to 13% of proteins showed variable expression with age, more changes were observed when comparing between the two cell lines with up to 47% of HCPs differentially expressed. A small subset (50 HCPs) with age-dependent expression were previously reported to be problematic as high-risk and/or difficult-to-remove impurities; however, the vast majority of these were downregulated with age. Our findings suggest that HCP expression changes over this time scale may not be as dramatic and pose as great of a challenge to downstream processing as originally expected but that monitoring of variably expressed problematic HCPs remains critical.
Description
This is the peer reviewed version of the following article: Hamaker, N. K., Min, L., & Lee, K. H. (2022). Comprehensive assessment of host cell protein expression after extended culture and bioreactor production of CHO cell lines. Biotechnology and Bioengineering, 1– 18. https://doi.org/10.1002/bit.28128, which has been published in final form at https://doi.org/10.1002/bit.28128. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited. This article will be embargoed until 05/04/2023.
Keywords
biomanufacturing, CHO cells, host cell proteins, monoclonal antibody, proteomics
Citation
Hamaker, N. K., Min, L., & Lee, K. H. (2022). Comprehensive assessment of host cell protein expression after extended culture and bioreactor production of CHO cell lines. Biotechnology and Bioengineering, 1– 18. https://doi.org/10.1002/bit.28128