Model-based investigation of intracellular processes determining antibody Fc-glycosylation under mild hypothermia.
Model-based investigation of intracellular processes determining antibody Fc-glycosylation under mild hypothermia.
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DOI：
10.1002/bit.26225
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发表时间：
2017-07
影响因子：
3.8
通讯作者：
Kontoravdi C
中科院分区：
文献类型：
--
作者：
Sou SN;Jedrzejewski PM;Lee K;Sellick C;Polizzi KM;Kontoravdi C
尽管在哺乳动物细胞培养期间，轻度低温条件对单克隆抗体（mAb）生产率（q mAb）具有积极影响，但降低培养温度对mAb Fc-糖基化的影响以及聚糖组成变化背后的机制尚未完全确立。对亚低温条件下细胞内动态过程调控的认识不足限制了生物过程的优化。为了解决这个问题，构建了一个数学模型，定量描述了诱导亚低温前后中国仓鼠卵巢（CHO）细胞的行为和代谢、mAb合成和mAb N-连接糖基化特征。本研究的结果表明，该模型能够很好地代表上述所有方面的实验结果，包括在亚低温下产生的mAb的N-连接糖基化谱。最重要的是，不同培养温度的模型模拟结果之间的比较表明，核苷酸糖供体产生和半乳糖基转移酶（GalT）表达的速率降低是决定稳定CHO转染子中生理和轻度低温条件之间Fc-聚糖谱变化的关键影响因素。然后，使用GalT表达水平的实验测量来证实这一点，从而闭合实验和计算系统之间的回路。在轻度低温条件下CHO细胞代谢内的瓶颈的鉴定将有助于生物过程优化，例如，通过定制补料策略以改善NSD生产，或通过细胞系工程操纵特定糖基转移酶的表达。Biotechnol. Bioeng. 2017;114：1570-1582.© 2016作者。生物技术和生物工程出版的威利期刊公司。
Despite the positive effects of mild hypothermic conditions on monoclonal antibody (mAb) productivity (q mAb) during mammalian cell culture, the impact of reduced culture temperature on mAb Fc‐glycosylation and the mechanism behind changes in the glycan composition are not fully established. The lack of knowledge about the regulation of dynamic intracellular processes under mild hypothermia restricts bioprocess optimization. To address this issue, a mathematical model that quantitatively describes Chinese hamster ovary (CHO) cell behavior and metabolism, mAb synthesis and mAb N‐linked glycosylation profile before and after the induction of mild hypothermia is constructed. Results from this study show that the model is capable of representing experimental results well in all of the aspects mentioned above, including the N‐linked glycosylation profile of mAb produced under mild hypothermia. Most importantly, comparison between model simulation results for different culture temperatures suggests the reduced rates of nucleotide sugar donor production and galactosyltransferase (GalT) expression to be critical contributing factors that determine the variation in Fc‐glycan profiles between physiological and mild hypothermic conditions in stable CHO transfectants. This is then confirmed using experimental measurements of GalT expression levels, thereby closing the loop between the experimental and the computational system. The identification of bottlenecks within CHO cell metabolism under mild hypothermic conditions will aid bioprocess optimization, for example, by tailoring feeding strategies to improve NSD production, or manipulating the expression of specific glycosyltransferases through cell line engineering. Biotechnol. Bioeng. 2017;114: 1570–1582. © 2016 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals Inc.