Alden Nicholas, Raju Ravali, McElearney Kyle, Lambropoulos James, Kshirsagar Rashmi, Gilbert Alan, Lee Kyongbum
Department of Chemical and Biological Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA.
Biogen, 225 Binney St, Cambridge, MA 02142, USA.
Metabolites. 2020 May 15;10(5):199. doi: 10.3390/metabo10050199.
Chinese hamster ovary (CHO) cells are widely used for the production of biopharmaceuticals. Efforts to improve productivity through medium design and feeding strategy optimization have focused on preventing the depletion of essential nutrients and managing the accumulation of lactate and ammonia. In addition to ammonia and lactate, many other metabolites accumulate in CHO cell cultures, although their effects remain largely unknown. Elucidating these effects has the potential to further improve the productivity of CHO cell-based bioprocesses. This study used untargeted metabolomics to identify metabolites that accumulate in fed-batch cultures of monoclonal antibody (mAb) producing CHO cells. The metabolomics experiments profiled six cell lines that are derived from two different hosts, produce different mAbs, and exhibit different growth profiles. Comparing the cell lines' metabolite profiles at different growth stages, we found a strong negative correlation between peak viable cell density (VCD) and a tryptophan metabolite, putatively identified as 5-hydroxyindoleacetaldehyde (5-HIAAld). Amino acid supplementation experiments showed strong growth inhibition of all cell lines by excess tryptophan, which correlated with the accumulation of 5-HIAAld in the culture medium. Prospectively, the approach presented in this study could be used to identify cell line- and host-independent metabolite markers for clone selection and bioprocess development.
中国仓鼠卵巢（CHO）细胞被广泛用于生物制药的生产。通过培养基设计和补料策略优化来提高生产力的努力主要集中在防止必需营养物质的耗尽以及控制乳酸和氨的积累。除了氨和乳酸外，许多其他代谢产物也会在CHO细胞培养物中积累，尽管它们的影响在很大程度上仍不为人知。阐明这些影响有可能进一步提高基于CHO细胞的生物工艺的生产力。本研究使用非靶向代谢组学来鉴定在生产单克隆抗体（mAb）的CHO细胞的分批补料培养物中积累的代谢产物。代谢组学实验分析了来自两种不同宿主、产生不同mAb且具有不同生长曲线的六种细胞系。比较不同生长阶段细胞系的代谢产物谱，我们发现峰值活细胞密度（VCD）与一种色氨酸代谢产物之间存在强烈的负相关，该代谢产物被推测为5-羟基吲哚乙醛（5-HIAAld）。氨基酸补充实验表明，过量色氨酸对所有细胞系均有强烈的生长抑制作用，这与培养基中5-HIAAld的积累相关。前瞻性地看，本研究中提出的方法可用于鉴定用于克隆选择和生物工艺开发的与细胞系和宿主无关的代谢产物标志物。
