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Characterization of glutathione proteome in CHO cells and its relationship with productivity and cholesterol synthesis.
  • +2
  • Valentine Chevallier,
  • Erwin Schoof,
  • Laetitia Malphettes,
  • Mikael Rørdam Andersen,
  • Christopher Workman
Valentine Chevallier
UCB NORDIC A/S
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Erwin Schoof
Danmarks Tekniske Universitet
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Laetitia Malphettes
UCB Pharma SA
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Mikael Rørdam Andersen
Danmarks Tekniske Universitet, Technical University of Denmark
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Christopher Workman
Danmarks Tekniske Universitet
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Peer review status:UNDER REVIEW

17 Mar 2020Submitted to Biotechnology and Bioengineering
18 Mar 2020Submission Checks Completed
18 Mar 2020Assigned to Editor
29 Mar 2020Reviewer(s) Assigned
26 Apr 2020Editorial Decision: Revise Major
26 Apr 2020Review(s) Completed, Editorial Evaluation Pending
05 Jun 20201st Revision Received
05 Jun 2020Submission Checks Completed
05 Jun 2020Assigned to Editor
15 Jun 2020Reviewer(s) Assigned

Abstract

Glutathione (GSH) plays a central role in the redox balance maintenance in mammalian cells. The study of industrial CHO cell lines have demonstrated a close link between GSH metabolism and clone productivity. However, a deep investigation is still required to understand this correlation and highlights new potential targets for cell engineering. In this study, we have modulated the GSH intracellular content of an industrial cell line under bioprocess conditions in order to further elucidate the role of the GSH synthesis pathway. Two strategies were used : the variation of cystine supply and the direct inhibition of the GSH synthesis using buthionine sulfoximine (BSO). Cysteine supply modulation have revealed a correlation between intracellular GSH and product titer over time. Analysis of metabolites uptake/secretion rates and proteome comparison between BSO-treated cells and non-treated cells has highlighted a slow down of the TCA cycle leading to a secretion of lactate and alanine in the extracellular environment. Moreover, an adaptation of the glutathione related proteome has been observed with a up-regulation of the regulatory subunit of glutamate cysteine ligase and a down-regulation of a specific glutathione transferase subgroup, the Mu family. Surprisingly, the main impact of BSO treatment was observed on a global down-regulation of the cholesterol synthesis pathways. As cholesterol is required for protein secretion, it can be the missing part of the jigsaw to finally elucidate the link between GSH synthesis and productivity.