1
|
Li ZM, Fan ZL, Wang XY, Wang TY. Factors Affecting the Expression of Recombinant Protein and Improvement Strategies in Chinese Hamster Ovary Cells. Front Bioeng Biotechnol 2022; 10:880155. [PMID: 35860329 PMCID: PMC9289362 DOI: 10.3389/fbioe.2022.880155] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 06/01/2022] [Indexed: 01/20/2023] Open
Abstract
Recombinant therapeutic proteins (RTPs) are important parts of biopharmaceuticals. Chinese hamster ovary cells (CHO) have become the main cell hosts for the production of most RTPs approved for marketing because of their high-density suspension growth characteristics, and similar human post-translational modification patterns et al. In recent years, many studies have been performed on CHO cell expression systems, and the yields and quality of recombinant protein expression have been greatly improved. However, the expression levels of some proteins are still low or even difficult-to express in CHO cells. It is urgent further to increase the yields and to express successfully the “difficult-to express” protein in CHO cells. The process of recombinant protein expression of is a complex, involving multiple steps such as transcription, translation, folding processing and secretion. In addition, the inherent characteristics of molecular will also affect the production of protein. Here, we reviewed the factors affecting the expression of recombinant protein and improvement strategies in CHO cells.
Collapse
Affiliation(s)
- Zheng-Mei Li
- School of Life Science and Technology, Xinxiang Medical University, Xinxiang, China
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang, China
| | - Zhen-Lin Fan
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang, China
- Institutes of Health Central Plain, Xinxiang Medical University, Xinxiang, China
| | - Xiao-Yin Wang
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang, China
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, China
| | - Tian-Yun Wang
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang, China
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, China
- *Correspondence: Tian-Yun Wang,
| |
Collapse
|
2
|
Logan M, Rinas K, McConkey B, Aucoin MG. Vero cells gain renal tubule markers in low-calcium and magnesium chemically defined media. Sci Rep 2022; 12:6180. [PMID: 35418617 PMCID: PMC9008052 DOI: 10.1038/s41598-022-10221-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 03/28/2022] [Indexed: 11/17/2022] Open
Abstract
In this study, a chemically defined, animal component-free media was developed to promote Vero growth in suspension. Key media compounds were screened using Plackett–Burman styled experiments to create a media formulation to support suspension growth. Vero cells remained viable in suspension, but their growth rate was extremely low, conversely, other cell types such as CHO-K1, MDCK and HEK293T were able to grow in single cell suspension in the same media. To investigate the slow growth of Vero cells, RNA-seq analysis was conducted. Vero cells were cultured in three different conditions: adherently in serum-containing medium, adherently in in-house medium, and in suspension in low calcium and magnesium in-house medium. This study illustrates that adherent cells maintain similar gene expression, while the suspension phenotype tends to overexpress genes related to renal tubules.
Collapse
Affiliation(s)
- Megan Logan
- Department of Chemical Engineering, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Karsten Rinas
- Department of Biology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Brendan McConkey
- Department of Biology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Marc G Aucoin
- Department of Chemical Engineering, University of Waterloo, Waterloo, ON, N2L 3G1, Canada.
| |
Collapse
|
3
|
Kar N, Gupta D, Bellare J. Ethanol affects fibroblast behavior differentially at low and high doses: A comprehensive, dose-response evaluation. Toxicol Rep 2021; 8:1054-1066. [PMID: 34307054 PMCID: PMC8296147 DOI: 10.1016/j.toxrep.2021.05.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 04/19/2021] [Accepted: 05/17/2021] [Indexed: 12/17/2022] Open
Abstract
Ethanol exhibits hormetic response in terms of cellular activity. 1 % (v/v) ethanol concentration demarcates non-toxic and toxic range. Different types of mitochondrial impairment identified at high dose. Cellular toxicity is accompanied by an increase in cellular stiffness. Dose-dependent cellular stress response to toxicity is observed.
This study aims to develop a comprehensive understanding of effects of low and high doses of ethanol on cellular biochemistry and morphology. Here, fibroblast cells are exposed to ethanol of varied concentrations [0.005−10 % (v/v)] to investigate cellular activity, cytoskeletal organization, cellular stiffness, mitochondrial structure, and real-time behavior. Our results indicate a sharp difference in cellular behavior above and below 1 % ethanol concentration. A two-fold increase in MTT activity at low doses is observed, whereas at high doses it decreases. This increased activity at low doses does not involve cell proliferation changes or mitochondrial impairment, as seen at higher doses. Moreover, the study identifies different types of mitochondrial structure impairment at high doses. Morphologically, cells demonstrate a gradual change in cytoskeletal organization and an increase in cell stiffness with increase in doses. Cells exhibit adaptation to sub-toxic doses of ethanol, wherein recovery from ethanol-induced stress is a dose-dependent phenomenon. Cell survival at low doses and toxicity at higher doses are attributed to mild and strong oxidative stress, respectively. Overall, the study provides a comprehensive understanding of dose-dependent effects of ethanol, manifesting its biphasic or hormetic response, biochemically, at low doses and illustrating its toxicological effects at higher doses.
Collapse
Affiliation(s)
- Neelakshi Kar
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, 400076, India
| | - Deepak Gupta
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, 400076, India
| | - Jayesh Bellare
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, 400076, India.,Wadhwani Research Centre for Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, 400076, India
| |
Collapse
|
4
|
Patil AA, Bhor SA, Rhee WJ. Cell death in culture: Molecular mechanisms, detections, and inhibition strategies. J IND ENG CHEM 2020. [DOI: 10.1016/j.jiec.2020.08.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
5
|
Mufarrege EF, Benizio EL, Prieto CC, Chiappini F, Rodriguez MC, Etcheverrigaray M, Kratje RB. Development of Magoh protein-overexpressing HEK cells for optimized therapeutic protein production. Biotechnol Appl Biochem 2020; 68:230-238. [PMID: 32249976 DOI: 10.1002/bab.1915] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 03/25/2020] [Indexed: 11/07/2022]
Abstract
In the pharmaceutical industry, the need for high levels of protein expression in mammalian cells has prompted the search for new strategies, including technologies to obtain cells with improved mechanisms that enhance its transcriptional activity, folding, or protein secretion. Chinese Hamster Ovary (CHO) cells are by far the most used host cell for therapeutic protein expression. However, these cells produce specific glycans that are not present in human cells and therefore potentially immunogenic. As a result, there is an increased interest in the use of human-derived cells for therapeutic protein production. For many decades, human embryonic kidney (HEK) cells were exclusively used for research. However, two products for therapeutic indication were recently approved in the United States. It was previously shown that tethered Magoh, an Exon-junction complex core component, to specific mRNA sequences, have had significant positive effects on mRNA translational efficiency. In this study, a HEK Magoh-overexpressing cell line and clones, designated here as HEK-MAGO, were developed for the first time. These cells exhibited improved characteristics in protein expression, reaching -two- to threefold increases in rhEPO protein production in comparison with the wild-type cells. Moreover, this effect was promoter independent highlighting the versatility of this expression platform.
Collapse
Affiliation(s)
- Eduardo F Mufarrege
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Edificio FBCB - Ciudad Universitaria UNL, Santa Fe, Argentina.,Cell Culture Laboratory, Edificio FBCB, Ciudad Universitaria UNL, Santa Fe, Argentina
| | - Evangelina L Benizio
- Cell Culture Laboratory, Edificio FBCB, Ciudad Universitaria UNL, Santa Fe, Argentina
| | - Claudio C Prieto
- Cell Culture Laboratory, Edificio FBCB, Ciudad Universitaria UNL, Santa Fe, Argentina
| | - Fabricio Chiappini
- Cell Culture Laboratory, Edificio FBCB, Ciudad Universitaria UNL, Santa Fe, Argentina
| | | | - Marina Etcheverrigaray
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Edificio FBCB - Ciudad Universitaria UNL, Santa Fe, Argentina.,Cell Culture Laboratory, Edificio FBCB, Ciudad Universitaria UNL, Santa Fe, Argentina
| | - Ricardo B Kratje
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Edificio FBCB - Ciudad Universitaria UNL, Santa Fe, Argentina.,Cell Culture Laboratory, Edificio FBCB, Ciudad Universitaria UNL, Santa Fe, Argentina
| |
Collapse
|
6
|
Golabgir A, Gutierrez JM, Hefzi H, Li S, Palsson BO, Herwig C, Lewis NE. Quantitative feature extraction from the Chinese hamster ovary bioprocess bibliome using a novel meta-analysis workflow. Biotechnol Adv 2016; 34:621-633. [DOI: 10.1016/j.biotechadv.2016.02.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Revised: 02/21/2016] [Accepted: 02/28/2016] [Indexed: 01/01/2023]
|
7
|
Chu C, Bottaro DP, Betenbaugh MJ, Shiloach J. Stable Ectopic Expression of ST6GALNAC5 Induces Autocrine MET Activation and Anchorage-Independence in MDCK Cells. PLoS One 2016; 11:e0148075. [PMID: 26848584 PMCID: PMC4743853 DOI: 10.1371/journal.pone.0148075] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 01/12/2016] [Indexed: 11/19/2022] Open
Abstract
The epithelial-mesenchymal transition (EMT) is a complex cancer progression that can boost the metastatic potential of transformed cells by inducing migration, loss of cell adhesion, and promoting proliferation under anchorage-independent conditions. A DNA microarray analysis was performed comparing parental anchorage-dependent MDCK cells and anchorage-independent MDCK cells that were engineered to express human siat7e (ST6GALNAC5). The comparison identified several genes involved in the EMT process that were differentially expressed between the anchorage-dependent and the anchorage-independent MDCK cell lines. The hepatocyte growth factor gene (hgf) was found to be over-expressed in the engineered MDCK-siat7e cells at both transcription and protein expression levels. Phosphorylation analysis of the MET receptor tyrosine kinase confirmed the activation of an autocrine loop of the HGF/ MET signaling pathway in the MDCK-siat7e cells. When MET activities were suppressed by using the small-molecular inhibitor drug PF-02341066 (Crizotinib), the anchorage-independent MDCK-siat7e cells reverted to the cellular morphology of the parental anchorage-dependent MDCK cells. These observations indicate that the MET receptor plays a central role in the growth properties of the MDCK cells and its phosphorylation status is likely dependent on sialylation. Further investigation of the downstream signaling targets in the MET network showed that the degree of MDCK cell adhesion correlated with secretion levels of a matrix metalloproteinase, MMP1, suggesting a role of metalloproteinases in the EMT process. These results demonstrate that in addition to its application in biotechnology processes, MDCK-siat7e may serve as a model cell for metastasis studies to decipher the sequence of events leading up to the activation of EMT.
Collapse
Affiliation(s)
- Chia Chu
- Biotechnology Core Laboratory, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Donald P. Bottaro
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Michael J. Betenbaugh
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Joseph Shiloach
- Biotechnology Core Laboratory, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
| |
Collapse
|
8
|
Chin CL, Chin HK, Chin CSH, Lai ET, Ng SK. Engineering selection stringency on expression vector for the production of recombinant human alpha1-antitrypsin using Chinese Hamster ovary cells. BMC Biotechnol 2015; 15:44. [PMID: 26033090 PMCID: PMC4450478 DOI: 10.1186/s12896-015-0145-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 04/17/2015] [Indexed: 11/28/2022] Open
Abstract
Background Expression vector engineering technology is one of the most convenient and timely method for cell line development to meet the rising demand of novel production cell line with high productivity. Destabilization of dihydrofolate reductase (dhfr) selection marker by addition of AU-rich elements and murine ornithine decarboxylase PEST region was previously shown to improve the specific productivities of recombinant human interferon gamma in CHO-DG44 cells. In this study, we evaluated novel combinations of engineered motifs for further selection marker attenuation to improve recombinant human alpha-1-antitrypsin (rhA1AT) production. Motifs tested include tandem PEST elements to promote protein degradation, internal ribosome entry site (IRES) mutations to impede translation initiation, and codon-deoptimized dhfr selection marker to reduce translation efficiency. Results After a 2-step methotrexate (MTX) amplification to 50 nM that took less than 3 months, the expression vector with IRES point mutation and dhfr-PEST gave a maximum titer of 1.05 g/l with the top producer cell pool. Further MTX amplification to 300 nM MTX gave a maximum titer of 1.15 g/l. Relative transcript copy numbers and dhfr protein expression in the cell pools were also analysed to demonstrate that the transcription of rhA1AT and dhfr genes were correlated due to the IRES linkage, and that the strategies of further attenuating dhfr protein expression with the use of a mutated IRES and tandem PEST, but not codon deoptimization, were effective in reducing dhfr protein levels in suspension serum free culture. Conclusions Novel combinations of engineered motifs for further selection marker attenuation were studied to result in the highest reported recombinant protein titer to our knowledge in shake flask batch culture of stable mammalian cell pools at 1.15 g/l, highlighting applicability of expression vector optimization in generating high producing stable cells essential for recombinant protein therapeutics production. Our results also suggest that codon usage of the selection marker should be considered for applications that may involve gene amplification and serum free suspension culture, since the overall codon usage and thus the general expression and regulation of host cell proteins may be affected in the surviving cells. Electronic supplementary material The online version of this article (doi:10.1186/s12896-015-0145-9) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Christine Lin Chin
- Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore.
| | - Hing Kah Chin
- Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore.
| | - Cara Sze Hui Chin
- Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore.
| | - Ethan Tingfeng Lai
- Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore.
| | - Say Kong Ng
- Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore. .,Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore, Singapore.
| |
Collapse
|
9
|
Le H, Vishwanathan N, Jacob NM, Gadgil M, Hu WS. Cell line development for biomanufacturing processes: recent advances and an outlook. Biotechnol Lett 2015; 37:1553-64. [PMID: 25971160 DOI: 10.1007/s10529-015-1843-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Accepted: 04/29/2015] [Indexed: 12/20/2022]
Abstract
At the core of a biomanufacturing process for recombinant proteins is the production cell line. It influences the productivity and product quality. Its characteristics also dictate process development, as the process is optimized to complement the producing cell to achieve the target productivity and quality. Advances in the past decade, from vector design to cell line screening, have greatly expanded our capability to attain producing cell lines with certain desired traits. Increasing availability of genomic and transcriptomic resources for industrially important cell lines coupled with advances in genome editing technology have opened new avenues for cell line development. These developments are poised to help biosimilar manufacturing, which requires targeting pre-defined product quality attributes, e.g., glycoform, to match the innovator's range. This review summarizes recent advances and discusses future possibilities in this area.
Collapse
|
10
|
Advances in Mammalian cell line development technologies for recombinant protein production. Pharmaceuticals (Basel) 2013; 6:579-603. [PMID: 24276168 PMCID: PMC3817724 DOI: 10.3390/ph6050579] [Citation(s) in RCA: 201] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 03/28/2013] [Accepted: 04/10/2013] [Indexed: 01/20/2023] Open
Abstract
From 2006 to 2011, an average of 15 novel recombinant protein therapeutics have been approved by US Food and Drug Administration (FDA) annually. In addition, the expiration of blockbuster biologics has also spurred the emergence of biosimilars. The increasing numbers of innovator biologic products and biosimilars have thus fuelled the demand of production cell lines with high productivity. Currently, mammalian cell line development technologies used by most biopharmaceutical companies are based on either the methotrexate (MTX) amplification technology or the glutamine synthetase (GS) system. With both systems, the cell clones obtained are highly heterogeneous, as a result of random genome integration by the gene of interest and the gene amplification process. Consequently, large numbers of cell clones have to be screened to identify rare stable high producer cell clones. As such, the cell line development process typically requires 6 to 12 months and is a time, capital and labour intensive process. This article reviews established advances in protein expression and clone screening which are the core technologies in mammalian cell line development. Advancements in these component technologies are vital to improve the speed and efficiency of generating robust and highly productive cell line for large scale production of protein therapeutics.
Collapse
|
11
|
CHO cells in biotechnology for production of recombinant proteins: current state and further potential. Appl Microbiol Biotechnol 2011; 93:917-30. [PMID: 22159888 DOI: 10.1007/s00253-011-3758-5] [Citation(s) in RCA: 509] [Impact Index Per Article: 39.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2011] [Revised: 11/09/2011] [Accepted: 11/10/2011] [Indexed: 10/14/2022]
|
12
|
Hackl M, Jakobi T, Blom J, Doppmeier D, Brinkrolf K, Szczepanowski R, Bernhart SH, Höner Zu Siederdissen C, Bort JAH, Wieser M, Kunert R, Jeffs S, Hofacker IL, Goesmann A, Pühler A, Borth N, Grillari J. Next-generation sequencing of the Chinese hamster ovary microRNA transcriptome: Identification, annotation and profiling of microRNAs as targets for cellular engineering. J Biotechnol 2011; 153:62-75. [PMID: 21392545 PMCID: PMC3119918 DOI: 10.1016/j.jbiotec.2011.02.011] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Revised: 02/24/2011] [Accepted: 02/25/2011] [Indexed: 01/30/2023]
Abstract
Chinese hamster ovary (CHO) cells are the predominant cell factory for the production of recombinant therapeutic proteins. Nevertheless, the lack in publicly available sequence information is severely limiting advances in CHO cell biology, including the exploration of microRNAs (miRNA) as tools for CHO cell characterization and engineering. In an effort to identify and annotate both conserved and novel CHO miRNAs in the absence of a Chinese hamster genome, we deep-sequenced small RNA fractions of 6 biotechnologically relevant cell lines and mapped the resulting reads to an artificial reference sequence consisting of all known miRNA hairpins. Read alignment patterns and read count ratios of 5' and 3' mature miRNAs were obtained and used for an independent classification into miR/miR* and 5p/3p miRNA pairs and discrimination of miRNAs from other non-coding RNAs, resulting in the annotation of 387 mature CHO miRNAs. The quantitative content of next-generation sequencing data was analyzed and confirmed using qPCR, to find that miRNAs are markers of cell status. Finally, cDNA sequencing of 26 validated targets of miR-17-92 suggests conserved functions for miRNAs in CHO cells, which together with the now publicly available sequence information sets the stage for developing novel RNAi tools for CHO cell engineering.
Collapse
Affiliation(s)
- Matthias Hackl
- Department of Biotechnology, University of Natural Resources and Life Sciences Vienna, Muthgasse 19, A-1190 Vienna, Austria
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Bort JAH, Stern B, Borth N. CHO-K1 host cells adapted to growth in glutamine-free medium by FACS-assisted evolution. Biotechnol J 2011; 5:1090-7. [PMID: 20931603 DOI: 10.1002/biot.201000095] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
During the process of recombinant cell line optimisation for production of biopharmaceuticals, multiple cellular properties like robustness against stress, the attainment of high cell concentrations and maintenance of high viability must be considered to maximize protein yield. To improve growth and viability, glutamine is supplemented as an alternative energy source for rapidly dividing cells that oxidize glucose inefficiently. However, the resulting by-product ammonia is toxic at high concentrations and has a negative impact on protein glycosylation, a major quality-determining parameter of biopharmaceuticals. In this work, the CHO-K1 cell line was adapted to a chemically defined medium and suspension growth within 3 weeks. Subsequently, the glutamine concentration was stepwise reduced from 8 to 4 and 2 mM. After each reduction, both the final cell concentration in the batch and the viability decreased. To force a rapid evolution of cells to achieve high final cell concentrations, cells were seeded at high densities (10(7) cells/mL) and surviving cells were sorted by FACS or MACS when viability declined to 10% (typically after 24 h). Sorted cells were grown in batch until viability declined to 10% and viable cells recovered again. The final sorted population was able to reach comparable or even better viable cell concentrations and showed a significantly improved viability compared to their ancestors. The 2 mM glutamine-adapted cell line was directly transferred into glutamine-free medium and was able to grow at comparable rates without requiring further adaptation. Cells compensated the lack of glutamine by increasing their consumption of glutamate and aspartate.
Collapse
Affiliation(s)
- Juan A Hernández Bort
- Department of Biotechnology, University of Natural Resources and Applied Life Sciences, Vienna, Austria
| | | | | |
Collapse
|
14
|
Dreesen IAJ, Fussenegger M. Ectopic expression of human mTOR increases viability, robustness, cell size, proliferation, and antibody production of chinese hamster ovary cells. Biotechnol Bioeng 2010; 108:853-66. [PMID: 21404259 DOI: 10.1002/bit.22990] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2010] [Revised: 10/11/2010] [Accepted: 10/18/2010] [Indexed: 01/14/2023]
Abstract
Engineering of mammalian production cell lines to improve titer and quality of biopharmaceuticals is a top priority of the biopharmaceutical manufacturing industry providing protein therapeutics to patients worldwide. While many engineering strategies have been successful in the past decade they were often based on the over-expression of a single transgene and therefore limited to addressing a single bottleneck in the cell's production capacity. We provide evidence that ectopic expression of the global metabolic sensor and processing protein mammalian target of rapamycin (mTOR), simultaneously improves key bioprocess-relevant characteristics of Chinese hamster ovary (CHO) cell-derived production cell lines such as cell growth (increased cell size and protein content), proliferation (increased cell-cycle progression), viability (decreased apoptosis), robustness (decreased sensitivity to sub-optimal growth factor and oxygen supplies) and specific productivity of secreted human glycoproteins. Cultivation of mTOR-transgenic CHO-derived cell lines engineered for secretion of a therapeutic IgG resulted in antibody titers of up to 50 pg/cell/day, which represents a four-fold increase compared to the parental production cell line. mTOR-based engineering of mammalian production cell lines may therefore have a promising future in biopharmaceutical manufacturing of human therapeutic proteins.
Collapse
Affiliation(s)
- Imke A J Dreesen
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, CH-4058 Basel, Switzerland
| | | |
Collapse
|
15
|
Krampe B, Al-Rubeai M. Cell death in mammalian cell culture: molecular mechanisms and cell line engineering strategies. Cytotechnology 2010; 62:175-88. [PMID: 20502964 DOI: 10.1007/s10616-010-9274-0] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Accepted: 04/12/2010] [Indexed: 12/15/2022] Open
Abstract
Cell death is a fundamentally important problem in cell lines used by the biopharmaceutical industry. Environmental stress, which can result from nutrient depletion, by-product accumulation and chemical agents, activates through signalling cascades regulators that promote death. The best known key regulators of death process are the Bcl-2 family proteins which constitute a critical intracellular checkpoint of apoptosis cell death within a common death pathway. Engineering of several members of the anti-apoptosis Bcl-2 family genes in several cell types has extended the knowledge of their molecular function and interaction with other proteins, and their regulation of cell death. In this review, we describe the various modes of cell death and their death pathways at molecular and organelle level and discuss the relevance of the growing knowledge of anti-apoptotic engineering strategies to inhibit cell death and increase productivity in mammalian cell culture.
Collapse
Affiliation(s)
- Britta Krampe
- School of Chemical and Bioprocess Engineering, and Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Belfield, Dublin 4, Republic of Ireland
| | | |
Collapse
|