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Eisenhut P, Marx N, Borsi G, Papež M, Ruggeri C, Baumann M, Borth N. Manipulating gene expression levels in mammalian cell factories: An outline of synthetic molecular toolboxes to achieve multiplexed control. N Biotechnol 2024; 79:1-19. [PMID: 38040288 DOI: 10.1016/j.nbt.2023.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/06/2023] [Accepted: 11/26/2023] [Indexed: 12/03/2023]
Abstract
Mammalian cells have developed dedicated molecular mechanisms to tightly control expression levels of their genes where the specific transcriptomic signature across all genes eventually determines the cell's phenotype. Modulating cellular phenotypes is of major interest to study their role in disease or to reprogram cells for the manufacturing of recombinant products, such as biopharmaceuticals. Cells of mammalian origin, for example Chinese hamster ovary (CHO) and Human embryonic kidney 293 (HEK293) cells, are most commonly employed to produce therapeutic proteins. Early genetic engineering approaches to alter their phenotype have often been attempted by "uncontrolled" overexpression or knock-down/-out of specific genetic factors. Many studies in the past years, however, highlight that rationally regulating and fine-tuning the strength of overexpression or knock-down to an optimum level, can adjust phenotypic traits with much more precision than such "uncontrolled" approaches. To this end, synthetic biology tools have been generated that enable (fine-)tunable and/or inducible control of gene expression. In this review, we discuss various molecular tools used in mammalian cell lines and group them by their mode of action: transcriptional, post-transcriptional, translational and post-translational regulation. We discuss the advantages and disadvantages of using these tools for each cell regulatory layer and with respect to cell line engineering approaches. This review highlights the plethora of synthetic toolboxes that could be employed, alone or in combination, to optimize cellular systems and eventually gain enhanced control over the cellular phenotype to equip mammalian cell factories with the tools required for efficient production of emerging, more difficult-to-express biologics formats.
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Affiliation(s)
- Peter Eisenhut
- Austrian Centre of Industrial Biotechnology (acib GmbH), Muthgasse 11, 1190 Vienna, Austria
| | - Nicolas Marx
- BOKU University of Natural Resources and Life Sciences, Institute of Animal Cell Technology and Systems Biology, Muthgasse 18, 1190 Vienna, Austria.
| | - Giulia Borsi
- BOKU University of Natural Resources and Life Sciences, Institute of Animal Cell Technology and Systems Biology, Muthgasse 18, 1190 Vienna, Austria
| | - Maja Papež
- Austrian Centre of Industrial Biotechnology (acib GmbH), Muthgasse 11, 1190 Vienna, Austria; BOKU University of Natural Resources and Life Sciences, Institute of Animal Cell Technology and Systems Biology, Muthgasse 18, 1190 Vienna, Austria
| | - Caterina Ruggeri
- BOKU University of Natural Resources and Life Sciences, Institute of Animal Cell Technology and Systems Biology, Muthgasse 18, 1190 Vienna, Austria
| | - Martina Baumann
- Austrian Centre of Industrial Biotechnology (acib GmbH), Muthgasse 11, 1190 Vienna, Austria
| | - Nicole Borth
- Austrian Centre of Industrial Biotechnology (acib GmbH), Muthgasse 11, 1190 Vienna, Austria; BOKU University of Natural Resources and Life Sciences, Institute of Animal Cell Technology and Systems Biology, Muthgasse 18, 1190 Vienna, Austria.
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2
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Jerabek T, Weiß L, Fahrion H, Zeh N, Raab N, Lindner B, Fischer S, Otte K. In pursuit of a minimal CHO genome: Establishment of large-scale genome deletions. N Biotechnol 2024; 79:100-110. [PMID: 38154614 DOI: 10.1016/j.nbt.2023.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 11/27/2023] [Accepted: 12/24/2023] [Indexed: 12/30/2023]
Abstract
Chinese hamster ovary (CHO) cells are the most commonly used mammalian cell line for the production of complex therapeutic glycoproteins. As CHO cells have evolved as part of a multicellular organism, they harbor many cellular functions irrelevant for their application as production hosts in industrial bioprocesses. Consequently, CHO cells have been the target for numerous genetic engineering efforts in the past, but a tailored host cell chassis holistically optimized for its specific task in a bioreactor is still missing. While the concept of genome reduction has already been successfully applied to bacterial production cells, attempts to create higher eukaryotic production hosts exhibiting reduced genomes have not been reported yet. Here, we present the establishment and application of a large-scale genome deletion strategy for targeted excision of large genomic regions in CHO cells. We demonstrate the feasibility of genome reduction in CHO cells using optimized CRISPR/Cas9 based experimental protocols targeting large non-essential genomic regions with high efficiency. Achieved genome deletions of non-essential genetic regions did not introduce negative effects on bioprocess relevant parameters, although we conducted the largest reported genomic excision of 864 kilobase pairs in CHO cells so far. The concept presented serves as a directive to accelerate the development of a significantly genome-reduced CHO host cell chassis paving the way for a next generation of CHO cell factories.
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Affiliation(s)
- Tobias Jerabek
- University of Applied Sciences Biberach, Institute of Applied Biotechnology, Biberach, Germany.
| | - Linus Weiß
- University of Applied Sciences Biberach, Institute of Applied Biotechnology, Biberach, Germany
| | - Hannah Fahrion
- University of Applied Sciences Biberach, Institute of Applied Biotechnology, Biberach, Germany
| | - Nikolas Zeh
- University of Applied Sciences Biberach, Institute of Applied Biotechnology, Biberach, Germany; Boehringer Ingelheim Pharma GmbH & Co KG, Bioprocess Development Biologicals, Cell Line Development, Biberach, Germany
| | - Nadja Raab
- University of Applied Sciences Biberach, Institute of Applied Biotechnology, Biberach, Germany
| | - Benjamin Lindner
- Boehringer Ingelheim Pharma GmbH & Co KG, Bioprocess Development Biologicals, Cell Line Development, Biberach, Germany
| | - Simon Fischer
- Boehringer Ingelheim Pharma GmbH & Co KG, Bioprocess Development Biologicals, Cell Line Development, Biberach, Germany
| | - Kerstin Otte
- University of Applied Sciences Biberach, Institute of Applied Biotechnology, Biberach, Germany
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Weiß L, Schmieder-Todtenhaupt V, Haemmerling F, Lakatos D, Schulz P, Fischer S. Multi-lipase gene knockdown in Chinese hamster ovary cells using artificial microRNAs to reduce host cell protein mediated polysorbate degradation. Biotechnol Bioeng 2024; 121:329-340. [PMID: 37743807 DOI: 10.1002/bit.28563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 09/05/2023] [Accepted: 09/12/2023] [Indexed: 09/26/2023]
Abstract
A large number of companies observe polysorbate (PS) degradation and associated (sub-)visible particle formation in biological drug formulations, which compromise the stability of the drug product, ultimately posing a risk toward delivering innovative medicines to patients. The main culprits of PS degradation are hydrolytic host cell proteins (HCPs) originating from the production cell lines, which are mostly Chinese hamster ovary (CHO) cell derived. Here, a small portion of particularly difficult-to-remove HCPs-mainly lipases-cause hydrolytic cleavage of PS resulting in the accumulation of free fatty acid aggregates/particles. One possible mitigation strategy is the removal of such critical HCPs in the production cell line. Multigene regulation can be achieved via microRNAs (miRNAs) thereby serving as a smart tool to reduce the expression of different target genes using a single miRNA. To enable a tailored gene regulation of multiple specific target lipases self-designed and non-naturally occurring artificial miRNAs (amiRNA) can be designed. Based on micro-conserved regions in the mRNA sequence of two sets of target HCPs, we provide a proof-of-concept for a simultaneous multi-lipase knockdown in CHO cells using single amiRNAs. By this, we were not only able to reduce PS degradation but laid the foundation to expand this tool to other areas of cell line phenotype engineering.
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Affiliation(s)
- Linus Weiß
- Cell Line Development, Bioprocess Development Biologicals, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Valerie Schmieder-Todtenhaupt
- Cell Line Development, Bioprocess Development Biologicals, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Frank Haemmerling
- Early Stage Pharmaceutical Development, Pharmaceutical Development Biologicals, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Daniel Lakatos
- Late Stage DSP, Bioprocess Development Biologicals, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Patrick Schulz
- Cell Line Development, Bioprocess Development Biologicals, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Simon Fischer
- Cell Line Development, Bioprocess Development Biologicals, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
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Novak N, Baumann M, Friss A, Cairns V, DeMaria C, Borth N. LncRNA analysis of mAb producing CHO clones reveals marker and engineering potential. Metab Eng 2023; 78:26-40. [PMID: 37196898 DOI: 10.1016/j.ymben.2023.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 05/09/2023] [Accepted: 05/14/2023] [Indexed: 05/19/2023]
Abstract
Long non-coding RNAs (lncRNAs) are a potential new cell line engineering tool for improvement of yield and stability of CHO cells. In this study, we performed RNA sequencing of mAb producer CHO clones to study the lncRNA and protein coding transcriptome in relation to productivity. First, a robust linear model was used to identify genes correlating to productivity. To unravel specific patterns in expression of these genes, we employed weighted gene coexpression analysis (WGCNA) to find coexpressed modules, looking both for lncRNAs and coding genes. There was little overlap in the genes associated with productivity between the two products studied, possibly due to the difference in absolute range of productivity between the two mAbs. Therefore, we focused on the product with higher productivity and stronger candidate lncRNAs. To evaluate their potential as engineering targets, these candidate lncRNAs were transiently overexpressed or deleted by stable CRISPR Cas9 knock out both in a high and a low productivity subclone. We found that the thus achieved expression level of the identified lncRNAs, as confirmed by qPCR, does correlate well to productivity, so that they represent good markers that may be used for early clone selection. Additionally, we found that the deletion of one tested lncRNA region decreased viable cell density (VCD), prolonged culture time and increased cell size, final titer and specific productivity per cell. These results demonstrate the feasibility and usefulness of engineering lncRNA expression in production cell lines.
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Affiliation(s)
- Neža Novak
- Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Austria; ACIB, Austrian Centre of Industrial Biotechnology, Graz, Austria
| | - Martina Baumann
- ACIB, Austrian Centre of Industrial Biotechnology, Graz, Austria
| | - Amy Friss
- Sanofi Biopharmaceutics Development, Framingham, MA, USA
| | - Victor Cairns
- Sanofi Biopharmaceutics Development, Framingham, MA, USA
| | | | - Nicole Borth
- Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Austria; ACIB, Austrian Centre of Industrial Biotechnology, Graz, Austria.
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Glinšek K, Bozovičar K, Bratkovič T. CRISPR Technologies in Chinese Hamster Ovary Cell Line Engineering. Int J Mol Sci 2023; 24:ijms24098144. [PMID: 37175850 PMCID: PMC10179654 DOI: 10.3390/ijms24098144] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 04/26/2023] [Accepted: 04/28/2023] [Indexed: 05/15/2023] Open
Abstract
The Chinese hamster ovary (CHO) cell line is a well-established platform for the production of biopharmaceuticals due to its ability to express complex therapeutic proteins with human-like glycopatterns in high amounts. The advent of CRISPR technology has opened up new avenues for the engineering of CHO cell lines for improved protein production and enhanced product quality. This review summarizes recent advances in the application of CRISPR technology for CHO cell line engineering with a particular focus on glycosylation modulation, productivity enhancement, tackling adventitious agents, elimination of problematic host cell proteins, development of antibiotic-free selection systems, site-specific transgene integration, and CRISPR-mediated gene activation and repression. The review highlights the potential of CRISPR technology in CHO cell line genome editing and epigenetic engineering for the more efficient and cost-effective development of biopharmaceuticals while ensuring the safety and quality of the final product.
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Affiliation(s)
- Katja Glinšek
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000 Ljubljana, Slovenia
| | - Krištof Bozovičar
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000 Ljubljana, Slovenia
| | - Tomaž Bratkovič
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000 Ljubljana, Slovenia
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Papež M, Jiménez Lancho V, Eisenhut P, Motheramgari K, Borth N. SLAM-seq reveals early transcriptomic response mechanisms upon glutamine deprivation in Chinese hamster ovary cells. Biotechnol Bioeng 2023; 120:970-986. [PMID: 36575109 DOI: 10.1002/bit.28320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 11/30/2022] [Accepted: 12/25/2022] [Indexed: 12/29/2022]
Abstract
Mammalian cells frequently encounter subtle perturbations during recombinant protein production. Identifying the genetic factors that govern the cellular stress response can facilitate targeted genetic engineering to obtain production cell lines that demonstrate a higher stress tolerance. To simulate nutrient stress, Chinese hamster ovary (CHO) cells were transferred into a glutamine(Q)-free medium and transcriptional dynamics using thiol(SH)-linked alkylation for the metabolic sequencing of RNA (SLAM-seq) along with standard RNA-seq of stressed and unstressed cells were investigated. The SLAM-seq method allows differentiation between actively transcribed, nascent mRNA, and total (previously present) mRNA in the sample, adding an additional, time-resolved layer to classic RNA-sequencing. The cells tackle amino acid (AA) limitation by inducing the integrated stress response (ISR) signaling pathway, reflected in Atf4 overexpression in the early hours post Q deprivation, leading to subsequent activation of its targets, Asns, Atf3, Ddit3, Eif4ebp1, Gpt2, Herpud1, Slc7a1, Slc7a11, Slc38a2, Trib3, and Vegfa. The GCN2-eIF2α-ATF4 pathway is confirmed by a significant halt in transcription of translation-related genes at 24 h post Q deprivation. The downregulation of lipid synthesis indicates the inhibition of the mTOR pathway, further confirmed by overexpression of Sesn2. Furthermore, SLAM-seq detects short-lived transcription factors, such as Egr1, that would have been missed in standard experimental designs with RNA-seq. Our results describe the successful establishment of SLAM-seq in CHO cells and therefore facilitate its future use in other scenarios where dynamic transcriptome profiling in CHO cells is essential.
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Affiliation(s)
- Maja Papež
- Austrian Centre of Industrial Biotechnology (acib GmbH), Graz, Austria
| | | | - Peter Eisenhut
- Austrian Centre of Industrial Biotechnology (acib GmbH), Graz, Austria
| | | | - Nicole Borth
- Austrian Centre of Industrial Biotechnology (acib GmbH), Graz, Austria
- University of Natural Resources and Life Sciences (BOKU), Vienna, Austria
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7
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Hussein MK, Papež M, Dhiman H, Baumann M, Galosy S, Borth N. In silico design of CMV promoter binding oligonucleotides and their impact on inhibition of gene expression in Chinese hamster ovary cells. J Biotechnol 2022; 359:185-193. [DOI: 10.1016/j.jbiotec.2022.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 09/30/2022] [Accepted: 10/04/2022] [Indexed: 10/31/2022]
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8
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Recent developments in miRNA based recombinant protein expression in CHO. Biotechnol Lett 2022; 44:671-681. [PMID: 35507207 DOI: 10.1007/s10529-022-03250-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Accepted: 03/30/2022] [Indexed: 11/02/2022]
Abstract
It is widely accepted that the growing demand for recombinant therapeutic proteins has led to the expansion of the biopharmaceutical industry and the development of strategies to increase recombinant protein production in mammalian cell lines such as SP2/0 HEK and particularly Chinese hamster ovary cells. For a long time now, most investigations have been focused on increasing host cell productivity using genetic manipulating of cellular processes like cell cycle, apoptosis, cell growth, protein secretory and other pathways. In recent decades MicroRNAs beside different genetic engineering tools (e.g., TALEN, ZFN, and Crisper/Cas) have attracted further attention as a tool in the genetic engineering of host cells to increase protein expression levels. Their ability to simultaneously target multiple mRNAs involved in one or more cellular processes made them a favorable tool in this field. Accordingly, this study aimed to review the methods of selecting target miRNA for cell line engineering, miRNA gain- or loss-of-function strategies, examples of laboratory and pilot studies in this field and discussed advantages and disadvantages of this technology.
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9
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Schmieder V, Novak N, Dhiman H, Nguyen LN, Serafimova E, Klanert G, Baumann M, Kildegaard HF, Borth N. A pooled CRISPR/AsCpf1 screen using paired gRNAs to induce genomic deletions in Chinese hamster ovary cells. ACTA ACUST UNITED AC 2021; 31:e00649. [PMID: 34277363 PMCID: PMC8261548 DOI: 10.1016/j.btre.2021.e00649] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 06/06/2021] [Accepted: 06/16/2021] [Indexed: 12/13/2022]
Abstract
• Development of a small-scale CRISPR/AsCpf1 screen in CHO. • Usage of paired gRNAs enables full deletion of coding or noncoding genomic regions. • Growth perturbing paired gRNAs identified. • Key points for considerations in future screens identified.
Chinese hamster ovary (CHO) cells are the most widely used host for the expression of therapeutic proteins. Recently, significant progress has been made due to advances in genome sequence and annotation quality to unravel the black box CHO. Nevertheless, in many cases the link between genotype and phenotype in the context of suspension cultivated production cell lines is still not fully understood. While frameshift approaches targeting coding genes are frequently used, the non-coding regions of the genome have received less attention with respect to such functional annotation. Importantly, for non-coding regions frameshift knock-out strategies are not feasible. In this study, we developed a CRISPR-mediated screening approach that performs full deletions of genomic regions to enable the functional study of both the translated and untranslated genome. An in silico pipeline for the computational high-throughput design of paired guide RNAs (pgRNAs) directing CRISPR/AsCpf1 was established and used to generate a library tackling process-related genes and long non-coding RNAs. Next generation sequencing analysis of the plasmid library revealed a sufficient, but highly variable pgRNA composition. Recombinase-mediated cassette exchange was applied for pgRNA library integration rather than viral transduction to ensure single copy representation of pgRNAs per cell. After transient AsCpf1 expression, cells were cultivated over two sequential batches to identify pgRNAs which massively affected growth and survival. By comparing pgRNA abundance, depleted candidates were identified and individually validated to verify their effect.
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Key Words
- AsCpf1, Cpf1 from Acidaminococcus sp BV3L6
- CHO, Chinese hamster ovary
- CPM, counts per million reads mapped
- CRISPR, Clustered Regularly Interspaced Short Palindromic Repeats
- CRISPR/AsCpf1
- Cas9, CRISPR-associated protein 9
- Chinese hamster ovary cells
- Cpf1, CRISPR-associated protein in Prevotella and Francisella
- DE, differentially expressed
- DOWN-TTS, downstream transcription termination site
- DR, differentially represented
- EV, empty vector
- EpoFc, Erythropoietin Fc fusion protein
- FACS, fluorescence activated cell sorting
- FC, fold change
- FDR, false discovery rate
- GS, glutamine synthetase
- Genetic screen
- NGS, next generation sequencing
- NTC, no template control
- PAM, protospacer adjacent motif
- PCA, principal component analysis
- Qp, specific productivity
- RMCE, recombinase-mediated cassette exchange
- TMM, trimmed mean of M values
- UP-TSS, upstream transcription start site
- VCD, viable cell density
- dCas9, deactivated Cas9
- gRNA, guide RNA
- genomic deletion
- lncRNA, long non-coding RNA
- ncGene, non-coding gene
- oligo, oligonucleotide
- paired gRNAs
- pgRNA, paired gRNA
- sgRNA, single guide RNA
- µ, growth rate
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Affiliation(s)
- Valerie Schmieder
- Department of Biotechnology, BOKU University of Natural Resources and Life Sciences, Muthgasse 18, Vienna, Austria.,acib GmbH, Austrian Centre of Industrial Biotechnology, Muthgasse 11, Vienna, Austria
| | - Neža Novak
- Department of Biotechnology, BOKU University of Natural Resources and Life Sciences, Muthgasse 18, Vienna, Austria.,acib GmbH, Austrian Centre of Industrial Biotechnology, Muthgasse 11, Vienna, Austria
| | - Heena Dhiman
- Department of Biotechnology, BOKU University of Natural Resources and Life Sciences, Muthgasse 18, Vienna, Austria.,acib GmbH, Austrian Centre of Industrial Biotechnology, Muthgasse 11, Vienna, Austria
| | - Ly Ngoc Nguyen
- Department of Biotechnology, BOKU University of Natural Resources and Life Sciences, Muthgasse 18, Vienna, Austria.,acib GmbH, Austrian Centre of Industrial Biotechnology, Muthgasse 11, Vienna, Austria
| | - Evgenija Serafimova
- Department of Biotechnology, BOKU University of Natural Resources and Life Sciences, Muthgasse 18, Vienna, Austria.,acib GmbH, Austrian Centre of Industrial Biotechnology, Muthgasse 11, Vienna, Austria
| | - Gerald Klanert
- acib GmbH, Austrian Centre of Industrial Biotechnology, Muthgasse 11, Vienna, Austria
| | - Martina Baumann
- acib GmbH, Austrian Centre of Industrial Biotechnology, Muthgasse 11, Vienna, Austria
| | - Helene Faustrup Kildegaard
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Building 220, Kemitorvet, Kgs. Lyngby, Denmark
| | - Nicole Borth
- Department of Biotechnology, BOKU University of Natural Resources and Life Sciences, Muthgasse 18, Vienna, Austria.,acib GmbH, Austrian Centre of Industrial Biotechnology, Muthgasse 11, Vienna, Austria
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Samoudi M, Masson HO, Kuo CC, Robinson CM, Lewis NE. From omics to Cellular mechanisms in mammalian cell factory development. Curr Opin Chem Eng 2021; 32:100688. [PMID: 37475722 PMCID: PMC10357924 DOI: 10.1016/j.coche.2021.100688] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Mammalian cells have been used widely as biopharmaceutical cell factories due to their ability to make complex biotherapeutic proteins with human-compatible modifications. However, their application for some products has been hampered by low protein yields. Numerous studies have aimed to characterize cellular bottlenecks in the hope of boosting protein productivity, but the complexity of the underlying pathways and the diversity of the modifications have complicated cell engineering when relying solely on traditional methodologies. Incorporating omics-based and systems approaches into cell engineering can provide valuable insights into desirable phenotypes of cell factories. Here, we discuss cell engineering strategies for enhancing protein productivity in mammalian cell factories, particularly CHO and HEK293, and the opportunities and limitations of the genome-wide screening and multi-omics approaches for guiding cell engineering. Systems biology strategies will also be discussed to show how they refine our understanding of the cellular mechanisms which will aid in effective engineering strategies.
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Affiliation(s)
- Mojtaba Samoudi
- Department of Pediatrics, University of California, San Diego, La Jolla, California, USA
| | - Helen O. Masson
- Department of Bioengineering, University of California, San Diego, La Jolla, California, USA
| | - Chih-Chung Kuo
- Department of Bioengineering, University of California, San Diego, La Jolla, California, USA
| | - Caressa M Robinson
- Department of Pediatrics, University of California, San Diego, La Jolla, California, USA
| | - Nathan E Lewis
- Department of Pediatrics, University of California, San Diego, La Jolla, California, USA
- Department of Bioengineering, University of California, San Diego, La Jolla, California, USA
- National Biologics Facility, Technical University of Denmark, Kgs. Lyngby, Denmark
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Gludovacz E, Schuetzenberger K, Resch M, Tillmann K, Petroczi K, Vondra S, Vakal S, Schosserer M, Virgolini N, Pollheimer J, Salminen TA, Jilma B, Borth N, Boehm T. Human diamine oxidase cellular binding and internalization in vitro and rapid clearance in vivo are not mediated by N-glycans but by heparan sulfate proteoglycan interactions. Glycobiology 2021; 31:444-458. [PMID: 32985651 DOI: 10.1093/glycob/cwaa090] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 09/03/2020] [Accepted: 09/16/2020] [Indexed: 12/17/2022] Open
Abstract
Human diamine oxidase (hDAO) rapidly inactivates histamine by deamination. No pharmacokinetic data are available to better understand its potential as a new therapeutic modality for diseases with excess local and systemic histamine, like anaphylaxis, urticaria or mastocytosis. After intravenous administration of recombinant hDAO to rats and mice, more than 90% of the dose disappeared from the plasma pool within 10 min. Human DAO did not only bind to various endothelial and epithelial cell lines in vitro, but was also unexpectedly internalized and visible in granule-like structures. The uptake of rhDAO into cells was dependent on neither the asialoglycoprotein-receptor (ASGP-R) nor the mannose receptor (MR) recognizing terminal galactose or mannose residues, respectively. Competition experiments with ASGP-R and MR ligands did not block internalization in vitro or rapid clearance in vivo. The lack of involvement of N-glycans was confirmed by testing various glycosylation mutants. High but not low molecular weight heparin strongly reduced the internalization of rhDAO in HepG2 cells and HUVECs. Human DAO was readily internalized by CHO-K1 cells, but not by the glycosaminoglycan- and heparan sulfate-deficient CHO cell lines pgsA-745 and pgsD-677, respectively. A docked heparin hexasaccharide interacted well with the predicted heparin binding site 568RFKRKLPK575. These results strongly imply that rhDAO clearance in vivo and cellular uptake in vitro is independent of N-glycan interactions with the classical clearance receptors ASGP-R and MR, but is mediated by binding to heparan sulfate proteoglycans followed by internalization via an unknown receptor.
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Affiliation(s)
- Elisabeth Gludovacz
- Department of Biotechnology, University of Natural Resources and Life Sciences, Muthgasse 18, Vienna 1190, Austria.,Department of Clinical Pharmacology, Medical University of Vienna, Waehringer Guertel 18-20, Vienna 1090, Austria
| | - Kornelia Schuetzenberger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, Vienna 1090, Austria
| | - Marlene Resch
- Department of Clinical Pharmacology, Medical University of Vienna, Waehringer Guertel 18-20, Vienna 1090, Austria
| | - Katharina Tillmann
- Center for Biomedical Research, Medical University of Vienna, Waehringer Guertel 18-20, Vienna 1090, Austria
| | - Karin Petroczi
- Department of Clinical Pharmacology, Medical University of Vienna, Waehringer Guertel 18-20, Vienna 1090, Austria
| | - Sigrid Vondra
- Department of Obstetrics and Gynecology, Medical University of Vienna, Waehringer Guertel 18-20, Vienna 1090, Austria
| | - Serhii Vakal
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Tykistökatu 6A, Turku 20520, Finland
| | - Markus Schosserer
- Department of Biotechnology, University of Natural Resources and Life Sciences, Muthgasse 18, Vienna 1190, Austria
| | - Nikolaus Virgolini
- Department of Biotechnology, University of Natural Resources and Life Sciences, Muthgasse 18, Vienna 1190, Austria
| | - Jürgen Pollheimer
- Department of Obstetrics and Gynecology, Medical University of Vienna, Waehringer Guertel 18-20, Vienna 1090, Austria
| | - Tiina A Salminen
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Tykistökatu 6A, Turku 20520, Finland
| | - Bernd Jilma
- Department of Clinical Pharmacology, Medical University of Vienna, Waehringer Guertel 18-20, Vienna 1090, Austria
| | - Nicole Borth
- Department of Biotechnology, University of Natural Resources and Life Sciences, Muthgasse 18, Vienna 1190, Austria
| | - Thomas Boehm
- Department of Clinical Pharmacology, Medical University of Vienna, Waehringer Guertel 18-20, Vienna 1090, Austria
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12
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Karottki KJLC, Hefzi H, Li S, Pedersen LE, Spahn PN, Joshi C, Ruckerbauer D, Bort JAH, Thomas A, Lee JS, Borth N, Lee GM, Kildegaard HF, Lewis NE. A metabolic CRISPR-Cas9 screen in Chinese hamster ovary cells identifies glutamine-sensitive genes. Metab Eng 2021; 66:114-122. [PMID: 33813034 DOI: 10.1016/j.ymben.2021.03.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 03/25/2021] [Accepted: 03/28/2021] [Indexed: 12/20/2022]
Abstract
Media and feed optimization have fueled many-fold improvements in mammalian biopharmaceutical production, but genome editing offers an emerging avenue for further enhancing cell metabolism and bioproduction. However, the complexity of metabolism, involving thousands of genes, makes it unclear which engineering strategies will result in desired traits. Here we present a comprehensive pooled CRISPR screen for CHO cell metabolism, including ~16,000 gRNAs against ~2500 metabolic enzymes and regulators. Using this screen, we identified a glutamine response network in CHO cells. Glutamine is particularly important since it is often over-fed to drive increased TCA cycle flux, but toxic ammonia may accumulate. With the screen we found one orphan glutamine-responsive gene with no clear connection to our network. Knockout of this novel and poorly characterized lipase, Abhd11, substantially increased growth in glutamine-free media by altering the regulation of the TCA cycle. Thus, the screen provides an invaluable targeted platform to comprehensively study genes involved in any metabolic trait, and elucidate novel regulators of metabolism.
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Affiliation(s)
| | - Hooman Hefzi
- The Novo Nordisk Foundation Center for Biosustainability at the University of California, San Diego, USA; Department of Pediatrics, University of California, San Diego, USA; Department of Bioengineering, University of California, San Diego, USA
| | - Songyuan Li
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Denmark
| | - Lasse Ebdrup Pedersen
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Denmark
| | - Philipp N Spahn
- The Novo Nordisk Foundation Center for Biosustainability at the University of California, San Diego, USA; Department of Pediatrics, University of California, San Diego, USA
| | - Chintan Joshi
- The Novo Nordisk Foundation Center for Biosustainability at the University of California, San Diego, USA; Department of Pediatrics, University of California, San Diego, USA
| | - David Ruckerbauer
- Austrian Centre of Industrial Biotechnology, Vienna, Austria; University of Natural Resources and Life Sciences, Vienna, Austria
| | | | - Alex Thomas
- The Novo Nordisk Foundation Center for Biosustainability at the University of California, San Diego, USA
| | - Jae Seong Lee
- Department of Molecular Science and Technology, Ajou University, Suwon, 16499, Republic of Korea
| | - Nicole Borth
- Austrian Centre of Industrial Biotechnology, Vienna, Austria; University of Natural Resources and Life Sciences, Vienna, Austria
| | - Gyun Min Lee
- Department of Biological Sciences, Kaist, 291 Daehak-Ro, Yuseong-Gu, Daejeon, 305-701, Republic of Korea
| | | | - Nathan E Lewis
- The Novo Nordisk Foundation Center for Biosustainability at the University of California, San Diego, USA; Department of Pediatrics, University of California, San Diego, USA; Department of Bioengineering, University of California, San Diego, USA; National Biologics Facility, Technical University of Denmark, Denmark.
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13
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Weinguny M, Klanert G, Eisenhut P, Lee I, Timp W, Borth N. Subcloning induces changes in the DNA-methylation pattern of outgrowing Chinese hamster ovary cell colonies. Biotechnol J 2021; 16:e2000350. [PMID: 33484505 DOI: 10.1002/biot.202000350] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 01/17/2021] [Accepted: 01/21/2021] [Indexed: 12/12/2022]
Abstract
Chinese hamster ovary (CHO) cells are the most extensively used mammalian production system for biologics intended for use in humans. A critical step in the establishment of production cell lines is single cell cloning, with the objective of achieving high productivity and product quality. Despite general use, knowledge of the effects of this process is limited. Importantly, single cell cloned cells display a wide array of observed phenotypes, which so far was attributed to the instability and variability of the CHO genome. In this study we present data indicating that the emergence of diverse phenotypes during single cell cloning is associated with changes in DNA methylation patterns and transcriptomes that occur during the subcloning process. The DNA methylation pattern of each analyzed subclone, randomly picked from all outgrowing clones of the experiment, had unique changes preferentially found in regulatory regions of the genome such as enhancers, and de-enriched in actively transcribed sequences (not including the respective promoters), indicating that these changes resulted in adaptations of the relative gene expression pattern. The transcriptome of each subclone also had a significant number of individual changes. These results indicate that epigenetic regulation is a hidden, but important player in cell line development with a major role in the establishment of high performing clones with improved characteristics for bioprocessing.
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Affiliation(s)
- Marcus Weinguny
- ACIB Gmbh, Austrian Centre of Industrial Biotechnology, Vienna, Austria.,Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Vienna, Austria
| | - Gerald Klanert
- ACIB Gmbh, Austrian Centre of Industrial Biotechnology, Vienna, Austria
| | - Peter Eisenhut
- ACIB Gmbh, Austrian Centre of Industrial Biotechnology, Vienna, Austria.,Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Vienna, Austria
| | - Isac Lee
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, USA
| | - Winston Timp
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, USA
| | - Nicole Borth
- ACIB Gmbh, Austrian Centre of Industrial Biotechnology, Vienna, Austria.,Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Vienna, Austria
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14
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Eisenhut P, Mebrahtu A, Moradi Barzadd M, Thalén N, Klanert G, Weinguny M, Sandegren A, Su C, Hatton D, Borth N, Rockberg J. Systematic use of synthetic 5'-UTR RNA structures to tune protein translation improves yield and quality of complex proteins in mammalian cell factories. Nucleic Acids Res 2020; 48:e119. [PMID: 33051690 PMCID: PMC7672427 DOI: 10.1093/nar/gkaa847] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 08/28/2020] [Accepted: 09/22/2020] [Indexed: 12/30/2022] Open
Abstract
Predictably regulating protein expression levels to improve recombinant protein production has become an important tool, but is still rarely applied to engineer mammalian cells. We therefore sought to set-up an easy-to-implement toolbox to facilitate fast and reliable regulation of protein expression in mammalian cells by introducing defined RNA hairpins, termed 'regulation elements (RgE)', in the 5'-untranslated region (UTR) to impact translation efficiency. RgEs varying in thermodynamic stability, GC-content and position were added to the 5'-UTR of a fluorescent reporter gene. Predictable translation dosage over two orders of magnitude in mammalian cell lines of hamster and human origin was confirmed by flow cytometry. Tuning heavy chain expression of an IgG with the RgEs to various levels eventually resulted in up to 3.5-fold increased titers and fewer IgG aggregates and fragments in CHO cells. Co-expression of a therapeutic Arylsulfatase-A with RgE-tuned levels of the required helper factor SUMF1 demonstrated that the maximum specific sulfatase activity was already attained at lower SUMF1 expression levels, while specific production rates steadily decreased with increasing helper expression. In summary, we show that defined 5'-UTR RNA-structures represent a valid tool to systematically tune protein expression levels in mammalian cells and eventually help to optimize recombinant protein expression.
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Affiliation(s)
- Peter Eisenhut
- ACIB Austrian Centre of Industrial Biotechnology, Krenngasse 37, 8010 Graz, Austria
- BOKU University of Natural Resources and Life Sciences, Department of Biotechnology, Vienna 1190, Austria
| | - Aman Mebrahtu
- KTH Royal Institute of Technology, Department of Protein Science, 10691 Stockholm, Sweden
| | - Mona Moradi Barzadd
- KTH Royal Institute of Technology, Department of Protein Science, 10691 Stockholm, Sweden
| | - Niklas Thalén
- KTH Royal Institute of Technology, Department of Protein Science, 10691 Stockholm, Sweden
| | - Gerald Klanert
- ACIB Austrian Centre of Industrial Biotechnology, Krenngasse 37, 8010 Graz, Austria
| | - Marcus Weinguny
- ACIB Austrian Centre of Industrial Biotechnology, Krenngasse 37, 8010 Graz, Austria
- BOKU University of Natural Resources and Life Sciences, Department of Biotechnology, Vienna 1190, Austria
| | - Anna Sandegren
- Affibody Medical AB, Scheeles väg 2, SE-171 65 Solna, Sweden
| | - Chao Su
- SOBI AB, Tomtebodavägen 23A, Stockholm, Sweden
| | - Diane Hatton
- AstraZeneca, Biopharmaceutical Development, Milstein Building, Granta Park, Cambridge CB21 6GH, UK
| | - Nicole Borth
- ACIB Austrian Centre of Industrial Biotechnology, Krenngasse 37, 8010 Graz, Austria
- BOKU University of Natural Resources and Life Sciences, Department of Biotechnology, Vienna 1190, Austria
| | - Johan Rockberg
- KTH Royal Institute of Technology, Department of Protein Science, 10691 Stockholm, Sweden
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15
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Lin PC, Liu R, Alvin K, Wahyu S, Murgolo N, Ye J, Du Z, Song Z. Improving Antibody Production in Stably Transfected CHO Cells by CRISPR-Cas9-Mediated Inactivation of Genes Identified in a Large-Scale Screen with Chinese Hamster-Specific siRNAs. Biotechnol J 2020; 16:e2000267. [PMID: 33079482 DOI: 10.1002/biot.202000267] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 09/25/2020] [Indexed: 11/07/2022]
Abstract
The Chinese hamster ovary (CHO) cell line is commonly used for the production of biotherapeutics. As cell productivity directly affects the cost of production, methods are developed to manipulate the expression of specific genes that are known to be involved in protein synthesis, folding, and secretion to increase productivity. However, there are no large-scale CHO-specific functional screens to identify novel gene targets that impact the production of secreted recombinant proteins. Here, a large-scale, CHO cell-specific small interfering RNA screen is performed to identify genes that consistently enhance antibody production when silenced in a panel of seven CHO cell lines. Four genes, namely, Cyp1a2, Atp5s, Dgki, and P3h2, are identified, and then selected for CRISPR-Cas9 knockout validation in recombinant CHO cell lines. Single knockout of Cyp1a2, Atp5s, or Dgki, but not P3h2, results in a more than 90% increase in specific antibody productivity. Overall, the knockout of Cyp1a2 demonstrates the most significant improvement of antibody production, with a minimal impact on cell growth.
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Affiliation(s)
- Pao-Chun Lin
- Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), 20 Biopolis Way, #04-01 Centros, Singapore, 138668, Singapore
| | - Ren Liu
- Cell Line Development, MRL, Merck & Co., Inc., 2000 Galloping Hill Road, Kenilworth, NJ, 07033, USA
| | - Krista Alvin
- Cell Line Development, MRL, Merck & Co., Inc., 2000 Galloping Hill Road, Kenilworth, NJ, 07033, USA
| | - Shahreel Wahyu
- Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), 20 Biopolis Way, #04-01 Centros, Singapore, 138668, Singapore
| | - Nicholas Murgolo
- Bioinformatics, MRL, Merck & Co., Inc., 2000 Galloping Hill Road, Kenilworth, NJ, 07033, USA
| | - Jianxin Ye
- Cell Line Development, MRL, Merck & Co., Inc., 2000 Galloping Hill Road, Kenilworth, NJ, 07033, USA
| | - Zhimei Du
- Cell Line Development, MRL, Merck & Co., Inc., 2000 Galloping Hill Road, Kenilworth, NJ, 07033, USA
| | - Zhiwei Song
- Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), 20 Biopolis Way, #04-01 Centros, Singapore, 138668, Singapore
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16
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Weinguny M, Eisenhut P, Klanert G, Virgolini N, Marx N, Jonsson A, Ivansson D, Lövgren A, Borth N. Random epigenetic modulation of CHO cells by repeated knockdown of DNA methyltransferases increases population diversity and enables sorting of cells with higher production capacities. Biotechnol Bioeng 2020; 117:3435-3447. [PMID: 32662873 PMCID: PMC7818401 DOI: 10.1002/bit.27493] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 05/25/2020] [Accepted: 07/12/2020] [Indexed: 12/15/2022]
Abstract
Chinese hamster ovary (CHO) cells produce a large share of today's biopharmaceuticals. Still, the generation of satisfactory producer cell lines is a tedious undertaking. Recently, it was found that CHO cells, when exposed to new environmental conditions, modify their epigenome, suggesting that cells adapt their gene expression pattern to handle new challenges. The major aim of the present study was to employ artificially induced, random changes in the DNA-methylation pattern of CHO cells to diversify cell populations and consequently increase the finding of cell lines with improved cellular characteristics. To achieve this, DNA methyltransferases and/or the ten-eleven translocation enzymes were downregulated by RNA interference over a time span of ∼16 days. Methylation analysis of the resulting cell pools revealed that the knockdown of DNA methyltransferases was highly effective in randomly demethylating the genome. The same approach, when applied to stable CHO producer cells resulted in (a) an increased productivity diversity in the cell population, and (b) a higher number of outliers within the population, which resulted in higher specific productivity and titer in the sorted cells. These findings suggest that epigenetics play a previously underestimated, but actually important role in defining the overall cellular behavior of production clones.
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Affiliation(s)
- Marcus Weinguny
- ACIB—Austrian Centre of Industrial BiotechnologyGrazAustria,Department of BiotechnologyUniversity of Natural Resources and Life SciencesViennaAustria
| | - Peter Eisenhut
- ACIB—Austrian Centre of Industrial BiotechnologyGrazAustria,Department of BiotechnologyUniversity of Natural Resources and Life SciencesViennaAustria
| | - Gerald Klanert
- ACIB—Austrian Centre of Industrial BiotechnologyGrazAustria
| | | | - Nicolas Marx
- ACIB—Austrian Centre of Industrial BiotechnologyGrazAustria,Department of BiotechnologyUniversity of Natural Resources and Life SciencesViennaAustria
| | | | | | | | - Nicole Borth
- ACIB—Austrian Centre of Industrial BiotechnologyGrazAustria,Department of BiotechnologyUniversity of Natural Resources and Life SciencesViennaAustria
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17
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Abaandou L, Sharma AK, Shiloach J. Knockout of the caspase 8-associated protein 2 gene improves recombinant protein expression in HEK293 cells through up-regulation of the cyclin-dependent kinase inhibitor 2A gene. Biotechnol Bioeng 2020; 118:186-198. [PMID: 32910455 DOI: 10.1002/bit.27561] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 07/29/2020] [Accepted: 09/03/2020] [Indexed: 12/21/2022]
Abstract
Cell lines used in bioproduction are routinely engineered to improve their production efficiency. Numerous strategies, such as random mutagenesis, RNA interference screens, and transcriptome analyses have been employed to identify effective engineering targets. A genome-wide small interfering RNA screen previously identified the CASP8AP2 gene as a potential engineering target for improved expression of recombinant protein in the HEK293 cell line. Here, we validate the CASP8AP2 gene as an engineering target in HEK293 cells by knocking it out using CRISPR/Cas9 genome editing and assessing the effect of its knockout on recombinant protein expression, cell growth, cell viability, and overall gene expression. HEK293 cells lacking CASP8AP2 showed a seven-fold increase in specific expression of recombinant luciferase and a 2.5-fold increase in specific expression of recombinant SEAP, without significantly affecting cell growth and viability. Transcriptome analysis revealed that the deregulation of the cell cycle, specifically the upregulation of the cyclin-dependent kinase inhibitor 2A (CDKN2A) gene, contributed to the improvement in recombinant protein expression in CASP8AP2 deficient cells. The results validate the CASP8AP2 gene is a viable engineering target for improved recombinant protein expression in the HEK293 cell line.
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Affiliation(s)
- Laura Abaandou
- Biotechnology Core Laboratory, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, Maryland, USA.,Department of Chemistry and Biochemistry, George Mason University, Fairfax, VA, USA
| | - Ashish K Sharma
- Biotechnology Core Laboratory, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, Maryland, USA
| | - Joseph Shiloach
- Biotechnology Core Laboratory, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, Maryland, USA
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18
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Weinguny M, Klanert G, Eisenhut P, Jonsson A, Ivansson D, Lövgren A, Borth N. Directed evolution approach to enhance efficiency and speed of outgrowth during single cell subcloning of Chinese Hamster Ovary cells. Comput Struct Biotechnol J 2020; 18:1320-1329. [PMID: 32612755 PMCID: PMC7306589 DOI: 10.1016/j.csbj.2020.05.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 05/16/2020] [Accepted: 05/17/2020] [Indexed: 01/08/2023] Open
Abstract
Chinese Hamster Ovary (CHO) cells are the working horse of the pharmaceutical industry. To obtain high producing cell clones and to satisfy regulatory requirements single cell cloning is a necessary step in cell line development. However, it is also a tedious, labor intensive and expensive process. Here we show an easy way to enhance subclonability using subcloning by single cell sorting itself as the selection pressure, resulting in improved subcloning performance of three different host cell lines. These improvements in subclonability also lead to an enhanced cellular growth behavior during standard batch culture. RNA-seq was performed to shed light on the underlying mechanisms, showing that there is little overlap in differentially expressed genes or associated pathways between the cell lines, each finding their individual strategy for optimization. However, in all three cell lines pathways associated with the extracellular matrix were found to be enriched, indicating that cells struggle predominantly with their microenvironment and possibly lack of cell-to-cell contact. The observed small overlap may hint that there are multiple ways for a cell line to achieve a certain phenotype due to numerous genetic and subsequently metabolic redundancies.
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Key Words
- CHO
- CHO cells
- CHO, Chinese hamster ovary
- Cell line development
- Cell sorting
- Chinese Hamster Ovary Cells
- CoI, clusters of interest
- DE, directed evolved
- Directed Evolution
- ECM, extracellular matrix
- ES, enrichment score
- FACS
- FACS, fluorescent-activated cell sorting
- Fluorescent-activated cell sorting
- GSEA, gene set analysis
- Growth enhancement
- Growth improvement
- LDC, limiting dilution cloning
- NES, negative enrichment score
- PC, principal component
- PCA, principal component analysis
- POI, product of interest
- RNA Sequencing
- RNA-Seq
- RNA-Seq, RNA sequencing
- SCC, single cell cloning
- Single Cell Cloning
- Single Cell Subcloning
- Subcloning
- lfcSE, logfoldstandard error
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Affiliation(s)
- Marcus Weinguny
- ACIB Gmbh, Austrian Centre of Industrial Biotechnology, Vienna, Austria
- Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Vienna, Austria
| | - Gerald Klanert
- ACIB Gmbh, Austrian Centre of Industrial Biotechnology, Vienna, Austria
| | - Peter Eisenhut
- ACIB Gmbh, Austrian Centre of Industrial Biotechnology, Vienna, Austria
- Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Vienna, Austria
| | | | | | | | - Nicole Borth
- ACIB Gmbh, Austrian Centre of Industrial Biotechnology, Vienna, Austria
- Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Vienna, Austria
- Corresponding author at: Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Muthgasse 18, 1190 Vienna, Austria.
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19
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Coats MT, Bydlinski N, Maresch D, Diendorfer A, Klanert G, Borth N. mRNA Transfection into CHO-Cells Reveals Production Bottlenecks. Biotechnol J 2019; 15:e1900198. [PMID: 31475780 DOI: 10.1002/biot.201900198] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 08/27/2019] [Indexed: 12/19/2022]
Abstract
Obtaining highly productive Chinese hamster ovary (CHO)-cell clones for the production of therapeutic proteins relies on multiple time-consuming selection steps. Several CHO-cell strains with high degrees of genomic and epigenetic variation are available. Each harbor potential advantages and disadvantages for any given product, particularly those considered difficult to express. A simple test system to quickly assess compatibility of cell line and product may therefore prove useful. Transient plasmid transfection falls short of the specific productivities of stable producer cells, making it unsuitable for the elucidation of high specific productivity bottlenecks. The aim of the study is to reach specific productivities approaching those of industrial production cell lines by transfection of in vitro transcribed mRNA. The system is characterized with respect to transfection efficacy (by quantitative PCR) and protein production (by flow cytometry and biolayer interferometry). Fluorescence of intracellular eGFP saturates at higher amounts of mRNA per cell, while the amount of secreted and intracellular EPO-Fc remain linearly correlated to the amount of mRNA taken up. Nevertheless, MS shows a severe reduction in N-glycosylation quality. This method allows for rapid elucidation of bottlenecks that would otherwise remain undetected until later during cell line development, giving insight into suitable strategies for preemptive targeted metabolic engineering and host cell line optimization.
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Affiliation(s)
- Michael T Coats
- Department of Biotechnology, BOKU University of Natural Resources and Life Sciences, 1190, Vienna, Austria
| | - Nina Bydlinski
- Department of Biotechnology, BOKU University of Natural Resources and Life Sciences, 1190, Vienna, Austria
| | - Daniel Maresch
- Department of Chemistry, BOKU University of Natural Resources and Life Sciences, 1190, Vienna, Austria
| | | | - Gerald Klanert
- Austrian Centre of Industrial Biotechnology GmbH, 8010, Graz, Austria
| | - Nicole Borth
- Department of Biotechnology, BOKU University of Natural Resources and Life Sciences, 1190, Vienna, Austria.,Austrian Centre of Industrial Biotechnology GmbH, 8010, Graz, Austria
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