1
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Liu HN, Wang XY, Zou Y, Wu WB, Lin Y, Ji BY, Wang TY. Synthetic enhancers including TFREs improve transgene expression in CHO cells. Heliyon 2024; 10:e26901. [PMID: 38468921 PMCID: PMC10926067 DOI: 10.1016/j.heliyon.2024.e26901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 02/12/2024] [Accepted: 02/21/2024] [Indexed: 03/13/2024] Open
Abstract
The human cytomegalovirus major immediate early gene (CMV) promoter is currently the most preferred promoter for recombinant therapeutic proteins (RTPs) production in CHO cells. To enhance the production of RTPs, five synthetic enhancers including multiple transcription factor regulatory elements (TFREs) were evaluated to enhance recombinant protein level in transient and stably transfected CHO cells. Compared with the control, four elements can enhance the report genes expression under both two transfected states. Further, the function of these four enhancers on human serum albumin (HSA) were investigated. We found that the transient expression can increase by up to 1.5 times, and the stably expression can maximum increase by up to 2.14 times. The enhancement of transgene expression was caused by the boost of their corresponding mRNA levels. Transcriptomics analysis was performed and found that transcriptional activation and cell cycle regulation genes were involved. In conclusion, optimization of enhancers in the CMV promoter could increase the production yield of transgene in transfected CHO cells, which has significance for developing high-yield CHO cell expression system.
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Affiliation(s)
- Hui-Ning Liu
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang 453003, China
- SanQuan College of Xinxiang Medical University, Xinxiang 453003, China
| | - Xiao-Yin Wang
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang 453003, China
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Xinxiang Medical University, Xinxiang 453003, China
| | - Ying Zou
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang 453003, China
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Xinxiang Medical University, Xinxiang 453003, China
| | - Wen-Bao Wu
- Shanghai Immunocan Biotech Co., LTD, Shanghai 200000, China
| | - Yan Lin
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang 453003, China
| | - Bo-Yu Ji
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang 453003, China
| | - Tian-Yun Wang
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang 453003, China
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Xinxiang Medical University, Xinxiang 453003, China
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2
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Nagy A, Chakrabarti L, Kurasawa J, Mulagapati SHR, Devine P, Therres J, Chen Z, Schmelzer AE. Engineered CHO cells as a novel AAV production platform for gene therapy delivery. Sci Rep 2023; 13:19210. [PMID: 37932360 PMCID: PMC10628118 DOI: 10.1038/s41598-023-46298-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 10/30/2023] [Indexed: 11/08/2023] Open
Abstract
The Herpes simplex virus (HSV)-based platform for production of recombinant adeno-associated viral vectors (rAAVs) yields higher titers and increased percentage of full capsids when compared to the triple transient transfection (TTT) method. However, this platform currently faces two major challenges. The first challenge is the reliance on commercial media, sometimes supplemented with serum, leading to costly manufacturing and a high risk for introduction of adventitious agents. The second challenge is that the production of HSV-1 relies on adherent complementing Vero cells (V27), making it difficult to scale up. We engineered serum-free-adapted CHO cells expressing key HSV-1 entry receptors, HVEM and/or Nectin-1 to address the first challenge. Using high-throughput cloning methods, we successfully selected a HVEM receptor-expressing clone (CHO-HV-C1) that yields 1.62 × 109, 2.51 × 109, and 4.07 × 109 viral genome copies/mL with rAAV6.2-GFP, rAAV8-GFP, and rAAV9-GFP vectors respectively, within 24 h post rHSV-1 co-infection. Moreover, CHO-HV-C1-derived rAAVs had comparable in vitro transduction, infectivity, and biodistribution titers to those produced by TTT. The second challenge was addressed via engineering CHO-HV-C1 cells to express HSV-1 CP27. These cells successfully produced rHSV-1 vectors, but with significantly lower titers than V27 cells. Taken together, the CHO/HSV system provides a novel, scalable, reduced cost, serum-free AAV manufacturing platform.
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Affiliation(s)
- Abdou Nagy
- Cell Culture and Fermentation Sciences, Biopharmaceutical Development, BioPharmaceuticals R&D, AstraZeneca, One MedImmune Way, Gaithersburg, MD, 20878, USA.
| | - Lina Chakrabarti
- Cell Culture and Fermentation Sciences, Biopharmaceutical Development, BioPharmaceuticals R&D, AstraZeneca, One MedImmune Way, Gaithersburg, MD, 20878, USA
| | - James Kurasawa
- Biologics Engineering, R&D, AstraZeneca, One MedImmune Way, Gaithersburg, MD, 20878, USA
| | - Sri Hari Raju Mulagapati
- Analytical Science, Biopharmaceutical Development, Biopharma R&D, AstraZeneca, One MedImmune Way, Gaithersburg, MD, 20878, USA
| | - Paul Devine
- Analytical Science, Biopharmaceutical Development, Biopharma R&D, AstraZeneca, Milstein Building, Granta Park, Cambridge, CB216GH, UK
| | - Jamy Therres
- Cell Culture and Fermentation Sciences, Biopharmaceutical Development, BioPharmaceuticals R&D, AstraZeneca, One MedImmune Way, Gaithersburg, MD, 20878, USA
| | - Zhongying Chen
- Clinical Pharmacology and Safety Sciences, AstraZeneca, One MedImmune Way, Gaithersburg, MD, 20878, USA
| | - Albert E Schmelzer
- Cell Culture and Fermentation Sciences, Biopharmaceutical Development, BioPharmaceuticals R&D, AstraZeneca, One MedImmune Way, Gaithersburg, MD, 20878, USA.
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3
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Yoon C, Baek KE, Kim D, Lee GM. Mitigating transcriptional bottleneck using a constitutively active transcription factor, VP16-CREB, in mammalian cells. Metab Eng 2023; 80:33-44. [PMID: 37709006 DOI: 10.1016/j.ymben.2023.09.005] [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: 08/13/2022] [Revised: 07/13/2023] [Accepted: 09/11/2023] [Indexed: 09/16/2023]
Abstract
High-level expression of recombinant proteins in mammalian cells has long been an area of interest. Inefficient transcription machinery is often an obstacle in achieving high-level expression of recombinant proteins in mammalian cells. Synthetic promoters have been developed to improve the transcription efficiency, but have achieved limited success due to the limited availability of transcription factors (TFs). Here, we present a TF-engineering approach to mitigate the transcriptional bottlenecks of recombinant proteins. This includes: (i) identification of cAMP response element binding protein (CREB) as a candidate TF by searching for TFs enriched in the cytomegalovirus (CMV) promoter-driven high-producing recombinant Chinese hamster ovary (rCHO) cell lines via transcriptome analysis, (ii) confirmation of transcriptional limitation of active CREB in rCHO cell lines, and (iii) direct activation of the transgene promoter by expressing constitutively active CREB at non-cytotoxic levels in rCHO cell lines. With the expression of constitutively active VP16-CREB, the production of therapeutic proteins, such as monoclonal antibody and etanercept, in CMV promoter-driven rCHO cell lines was increased up to 3.9-fold. VP16-CREB was also used successfully with synthetic promoters containing cAMP response elements. Taken together, this strategy to introduce constitutively active TFs into cells is a useful means of overcoming the transcriptional limitations in recombinant mammalian cells.
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Affiliation(s)
- Chansik Yoon
- Department of Biological Sciences, KAIST, Daejeon, 34141, Republic of Korea
| | - Kyoung Eun Baek
- Department of Biological Sciences, KAIST, Daejeon, 34141, Republic of Korea
| | - Dongil Kim
- Department of Biological Sciences, KAIST, Daejeon, 34141, Republic of Korea
| | - Gyun Min Lee
- Department of Biological Sciences, KAIST, Daejeon, 34141, Republic of Korea.
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4
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Sou SN, Harris CL, Williams R, Kozub D, Zurlo F, Patel YD, Kallamvalli Illam Sankaran P, Daramola O, Brown A, James DC, Hatton D, Dunn S, Gibson SJ. CHO synthetic promoters improve expression and product quality of biotherapeutic proteins. Biotechnol Prog 2023; 39:e3348. [PMID: 37114854 DOI: 10.1002/btpr.3348] [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: 12/13/2022] [Revised: 03/27/2023] [Accepted: 04/13/2023] [Indexed: 04/29/2023]
Abstract
When expressing complex biotherapeutic proteins, traditional expression plasmids and methods may not always yield sufficient levels of high-quality product. High-strength viral promoters commonly used for recombinant protein (rProtein) production in mammalian cells allow for maximal expression, but provide limited scope to alter their transcription dynamics. However, synthetic promoters designed to provide tunable transcriptional activity offer a plasmid engineering approach to more precisely regulate product quality, yield or to reduce product related contaminants. We substituted the viral promoter CMV with synthetic promoters that offer different transcriptional activities to express our gene of interest in Chinese hamster ovary (CHO) cells. Stable pools were established and the benefits of regulating transgene transcription on the quality of biotherapeutics were examined in stable pool fed-batch overgrow experiments. Specific control of gene expression of the heavy chain (HC):light chain (LC) of a Fab, and the ratio between the two HCs in a Duet mAb reduced levels of aberrant protein contaminants; and the controlled expression of the helper gene XBP-1s improved expression of a difficult-to-express mAb. This synthetic promoter technology benefits applications that require custom activity. Our work highlights the advantages of employing synthetic promoters for production of more complex rProteins.
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Affiliation(s)
- Si Nga Sou
- BioPharmaceutical Development, R&D, AstraZeneca, Cambridge, UK
| | - Claire L Harris
- BioPharmaceutical Development, R&D, AstraZeneca, Cambridge, UK
| | | | - Dorota Kozub
- BioPharmaceutical Development, R&D, AstraZeneca, Cambridge, UK
| | - Fabio Zurlo
- BioPharmaceutical Development, R&D, AstraZeneca, Cambridge, UK
| | - Yash D Patel
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield, UK
| | | | | | - Adam Brown
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield, UK
| | - David C James
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield, UK
| | - Diane Hatton
- BioPharmaceutical Development, R&D, AstraZeneca, Cambridge, UK
| | - Sarah Dunn
- BioPharmaceutical Development, R&D, AstraZeneca, Cambridge, UK
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5
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Chen WCW, Gaidukov L, Lai Y, Wu MR, Cao J, Gutbrod MJ, Choi GCG, Utomo RP, Chen YC, Wroblewska L, Kellis M, Zhang L, Weiss R, Lu TK. A synthetic transcription platform for programmable gene expression in mammalian cells. Nat Commun 2022; 13:6167. [PMID: 36257931 PMCID: PMC9579178 DOI: 10.1038/s41467-022-33287-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 09/13/2022] [Indexed: 12/24/2022] Open
Abstract
Precise, scalable, and sustainable control of genetic and cellular activities in mammalian cells is key to developing precision therapeutics and smart biomanufacturing. Here we create a highly tunable, modular, versatile CRISPR-based synthetic transcription system for the programmable control of gene expression and cellular phenotypes in mammalian cells. Genetic circuits consisting of well-characterized libraries of guide RNAs, binding motifs of synthetic operators, transcriptional activators, and additional genetic regulatory elements express mammalian genes in a highly predictable and tunable manner. We demonstrate the programmable control of reporter genes episomally and chromosomally, with up to 25-fold more activity than seen with the EF1α promoter, in multiple cell types. We use these circuits to program the secretion of human monoclonal antibodies and to control T-cell effector function marked by interferon-γ production. Antibody titers and interferon-γ concentrations significantly correlate with synthetic promoter strengths, providing a platform for programming gene expression and cellular function in diverse applications.
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Affiliation(s)
- William C W Chen
- Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA, 02114, USA.
- Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD, 57069, USA.
| | - Leonid Gaidukov
- Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Yong Lai
- Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Ming-Ru Wu
- Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA, 02215, USA
| | - Jicong Cao
- Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Michael J Gutbrod
- Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard University, Cambridge, MA, 02139, USA
| | - Gigi C G Choi
- Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Laboratory of Combinatorial Genetics and Synthetic Biology, School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Rachel P Utomo
- Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Biochemistry, Wellesley College, Wellesley, MA, 02481, USA
| | - Ying-Chou Chen
- Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan
| | | | - Manolis Kellis
- Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard University, Cambridge, MA, 02139, USA
| | - Lin Zhang
- Pfizer Inc., Andover, MA, 01810, USA
| | - Ron Weiss
- Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Timothy K Lu
- Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
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6
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Koyuturk I, Kedia S, Robotham A, Star A, Brochu D, Sauvageau J, Kelly J, Gilbert M, Durocher Y. High-level production of wild-type and oxidation-resistant recombinant alpha-1-antitrypsin in glycoengineered CHO cells. Biotechnol Bioeng 2022; 119:2331-2344. [PMID: 35508753 DOI: 10.1002/bit.28129] [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: 02/21/2022] [Revised: 04/24/2022] [Accepted: 05/03/2022] [Indexed: 11/10/2022]
Abstract
Alpha-1-antitrypsin (A1AT) is a serine protease inhibitor which blocks the activity of serum proteases including neutrophil elastase to protect the lungs. Its deficiency is known to increase the risk of pulmonary emphysema as well as chronic obstructive pulmonary disease. Currently, the only treatment for patients with A1AT deficiency is weekly injection of plasma-purified A1AT. There is still today no commercial source of therapeutic recombinant A1AT, likely due to significant differences in expression host-specific glycosylation profile and/or high costs associated with the huge therapeutic dose needed. Accordingly, we aimed to produce high levels of recombinant wild-type A1AT, as well as a mutated protein (mutein) version for increased oxidation resistance, with N-glycans analogous to human plasma-derived A1AT. To achieve this, we disrupted two endogenous glycosyltransferase genes controlling core α-1,6-fucosylation (Fut8) and α-2,3-sialylation (ST3Gal4) in CHO cells using CRISPR/Cas9 technology, followed by overexpression of human α-2,6-sialyltransferase (ST6Gal1) using a cumate-inducible expression system. Volumetric A1AT productivity obtained from stable CHO pools was 2.5- to 6.5-fold higher with the cumate-inducible CR5 promoter compared to five strong constitutive promoters. Using the CR5 promoter, glycoengineered stable CHO pools were able to produce over 2.1 g/L and 2.8 g/L of wild-type and mutein forms of A1AT, respectively, with N-glycans analogous to the plasma-derived clinical product Prolastin-C. Supplementation of N-acetylmannosamine to the cell culture media during production increased the overall sialylation of A1AT as well as the proportion of bi-antennary and disialylated A2G2S2 N-glycans. These purified recombinant A1AT proteins showed in vitro inhibitory activity equivalent to Prolastin-C and substitution of methionine residues 351 and 358 with valines rendered A1AT significantly more resistant to oxidation. The recombinant A1AT mutein bearing an improved oxidation-resistance described in this study could represent a viable biobetter drug, offering a safe and more stable alternative for augmentation therapy. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Izel Koyuturk
- Department of Biochemistry and Molecular Medicine, Faculty of Medicine, Université de Montréal, Qc, Canada, H3C 3J7.,Life Sciences, Human Health Therapeutics Research Centre, Building Montreal-Royalmount, National Research Council Canada, Montréal, Qc, Canada, H4P 2R2
| | - Surbhi Kedia
- Department of Parasitology, Faculty of Agricultural and Environmental Sciences, McGill University, Qc, Canada, H9X 3V9
| | - Anna Robotham
- Life Sciences, Human Health Therapeutics Research Centre, 100 Sussex Drive, National Research Council Canada, Ottawa, Ontario, Canada, K1A OR6
| | - Alexandra Star
- Life Sciences, Human Health Therapeutics Research Centre, 100 Sussex Drive, National Research Council Canada, Ottawa, Ontario, Canada, K1A OR6
| | - Denis Brochu
- Life Sciences, Human Health Therapeutics Research Centre, 100 Sussex Drive, National Research Council Canada, Ottawa, Ontario, Canada, K1A OR6
| | - Janelle Sauvageau
- Life Sciences, Human Health Therapeutics Research Centre, 100 Sussex Drive, National Research Council Canada, Ottawa, Ontario, Canada, K1A OR6
| | - John Kelly
- Life Sciences, Human Health Therapeutics Research Centre, 100 Sussex Drive, National Research Council Canada, Ottawa, Ontario, Canada, K1A OR6
| | - Michel Gilbert
- Life Sciences, Human Health Therapeutics Research Centre, 100 Sussex Drive, National Research Council Canada, Ottawa, Ontario, Canada, K1A OR6
| | - Yves Durocher
- Department of Biochemistry and Molecular Medicine, Faculty of Medicine, Université de Montréal, Qc, Canada, H3C 3J7.,Life Sciences, Human Health Therapeutics Research Centre, Building Montreal-Royalmount, National Research Council Canada, Montréal, Qc, Canada, H4P 2R2
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7
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Johnson AO, Fowler SB, Webster CI, Brown AJ, James DC. Bioinformatic Design of Dendritic Cell-Specific Synthetic Promoters. ACS Synth Biol 2022; 11:1613-1626. [PMID: 35389220 PMCID: PMC9016764 DOI: 10.1021/acssynbio.2c00027] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
![]()
Next-generation DNA vectors for cancer
immunotherapies and vaccine
development require promoters eliciting predefined transcriptional
activities specific to target cell types, such as dendritic cells
(DCs), which underpin immune response. In this study, we describe
the de novo design of DC-specific synthetic promoters via in silico assembly of cis-transcription
factor response elements (TFREs) that harness the DC transcriptional
landscape. Using computational genome mining approaches, candidate
TFREs were identified within promoter sequences of highly expressed
DC-specific genes or those exhibiting an upregulated expression during
DC maturation. Individual TFREs were then screened in vitro in a target DC line and off-target cell lines derived from skeletal
muscle, fibroblast, epithelial, and endothelial cells using homotypic
(TFRE repeats in series) reporter constructs. Based on these data,
a library of heterotypic promoter assemblies varying in the TFRE composition,
copy number, and sequential arrangement was constructed and tested in vitro to identify DC-specific promoters. Analysis of
the transcriptional activity and specificity of these promoters unraveled
underlying design rules, primarily TFRE composition, which govern
the DC-specific synthetic promoter activity. Using these design rules,
a second library of exclusively DC-specific promoters exhibiting varied
transcriptional activities was generated. All DC-specific synthetic
promoter assemblies exhibited >5-fold activity in the target DC
line
relative to off-target cell lines, with transcriptional activities
ranging from 8 to 67% of the nonspecific human cytomegalovirus (hCMV-IE1)
promoter. We show that bioinformatic analysis of a mammalian cell
transcriptional landscape is an effective strategy for de
novo design of cell-type-specific synthetic promoters with
precisely controllable transcriptional activities.
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Affiliation(s)
- Abayomi O. Johnson
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD, U.K
- SynGenSys Limited, Freeths LLP, Norfolk Street, Sheffield S1 2JE, U.K
| | - Susan B. Fowler
- Antibody Discovery and Protein Engineering, R&D, AstraZeneca, Cambridge CB21 6GH, U.K
| | - Carl I. Webster
- Discovery Sciences, R&D, AstraZeneca, Cambridge CB21 6GH, U.K
| | - Adam J. Brown
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD, U.K
- SynGenSys Limited, Freeths LLP, Norfolk Street, Sheffield S1 2JE, U.K
| | - David C. James
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD, U.K
- SynGenSys Limited, Freeths LLP, Norfolk Street, Sheffield S1 2JE, U.K
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8
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Fischell JM, Fishman PS. A Multifaceted Approach to Optimizing AAV Delivery to the Brain for the Treatment of Neurodegenerative Diseases. Front Neurosci 2021; 15:747726. [PMID: 34630029 PMCID: PMC8497810 DOI: 10.3389/fnins.2021.747726] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 08/31/2021] [Indexed: 12/12/2022] Open
Abstract
Despite major advancements in gene therapy technologies, there are no approved gene therapies for diseases which predominantly effect the brain. Adeno-associated virus (AAV) vectors have emerged as the most effective delivery vector for gene therapy owing to their simplicity, wide spread transduction and low immunogenicity. Unfortunately, the blood-brain barrier (BBB) makes IV delivery of AAVs, to the brain highly inefficient. At IV doses capable of widespread expression in the brain, there is a significant risk of severe immune-mediated toxicity. Direct intracerebral injection of vectors is being attempted. However, this method is invasive, and only provides localized delivery for diseases known to afflict the brain globally. More advanced methods for AAV delivery will likely be required for safe and effective gene therapy to the brain. Each step in AAV delivery, including delivery route, BBB transduction, cellular tropism and transgene expression provide opportunities for innovative solutions to optimize delivery efficiency. Intra-arterial delivery with mannitol, focused ultrasound, optimized AAV capsid evolution with machine learning algorithms, synthetic promotors are all examples of advanced strategies which have been developed in pre-clinical models, yet none are being investigated in clinical trials. This manuscript seeks to review these technological advancements, and others, to improve AAV delivery to the brain, and to propose novel strategies to build upon this research. Ultimately, it is hoped that the optimization of AAV delivery will allow for the human translation of many gene therapies for neurodegenerative and other neurologic diseases.
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Affiliation(s)
- Jonathan M Fischell
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Paul S Fishman
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, United States
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9
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Cazier AP, Blazeck J. Advances in promoter engineering: novel applications and predefined transcriptional control. Biotechnol J 2021; 16:e2100239. [PMID: 34351706 DOI: 10.1002/biot.202100239] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 07/30/2021] [Accepted: 08/03/2021] [Indexed: 11/08/2022]
Abstract
Synthetic biology continues to progress by relying on more robust tools for transcriptional control, of which promoters are the most fundamental component. Numerous studies have sought to characterize promoter function, determine principles to guide their engineering, and create promoters with stronger expression or tailored inducible control. In this review, we will summarize promoter architecture and highlight recent advances in the field, focusing on the novel applications of inducible promoter design and engineering towards metabolic engineering and cellular therapeutic development. Additionally, we will highlight how the expansion of new, machine learning techniques for modeling and engineering promoter sequences are enabling more accurate prediction of promoter characteristics. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Andrew P Cazier
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst St. NW, Atlanta, Georgia, 30332, USA
| | - John Blazeck
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst St. NW, Atlanta, Georgia, 30332, USA
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10
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Shin S, Kim SH, Lee JS, Lee GM. Streamlined Human Cell-Based Recombinase-Mediated Cassette Exchange Platform Enables Multigene Expression for the Production of Therapeutic Proteins. ACS Synth Biol 2021; 10:1715-1727. [PMID: 34133132 DOI: 10.1021/acssynbio.1c00113] [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] [Indexed: 11/29/2022]
Abstract
A platform, based on targeted integration of transgenes using recombinase-mediated cassette exchange (RMCE) coupled with CRISPR/Cas9, is increasingly being used for the development of mammalian cell lines that produce therapeutic proteins, because of reduced clonal variation and predictable transgene expression. However, low efficiency of the RMCE process has hampered its application in multicopy or multisite integration of transgenes. To improve RMCE efficiency, nuclear transport of RMCE components such as site-specific recombinase and donor plasmid was accelerated by incorporation of nuclear localization signal and DNA nuclear-targeting sequence, respectively. Consequently, the efficiency of RMCE in dual-landing pad human embryonic kidney 293 (HEK293) cell lines harboring identical or orthogonal pairs of recombination sites at two well-known human safe harbors (AAVS1 and ROSA26 loci), increased 6.7- and 8.1-fold, respectively. This platform with enhanced RMCE efficiency enabled simultaneous integration of transgenes at the two sites using a single transfection without performing selection and enrichment processes. The use of a homotypic dual-landing pad HEK293 cell line capable of incorporating the same transgenes at two sites resulted in a 2-fold increase in the transgene expression level compared to a single-landing pad HEK293 cell line. In addition, the use of a heterotypic dual-landing pad HEK293 cell line, which can incorporate transgenes for a recombinant protein at one site and an effector transgene for cell engineering at another site, increased recombinant protein production. Overall, a streamlined RMCE platform can be a versatile tool for mammalian cell line development by facilitating multigene expression at genomic safe harbors.
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Affiliation(s)
- Seunghyeon Shin
- Department of Biological Sciences, KAIST, Daejeon 34141, Republic of Korea
| | - Su Hyun Kim
- Department of Biological Sciences, KAIST, Daejeon 34141, Republic of Korea
| | - Jae Seong Lee
- Department of Molecular Science and Technology, Ajou University, Suwon 16499, Republic of Korea
| | - Gyun Min Lee
- Department of Biological Sciences, KAIST, Daejeon 34141, Republic of Korea
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11
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Patel YD, Brown AJ, Zhu J, Rosignoli G, Gibson SJ, Hatton D, James DC. Control of Multigene Expression Stoichiometry in Mammalian Cells Using Synthetic Promoters. ACS Synth Biol 2021; 10:1155-1165. [PMID: 33939428 PMCID: PMC8296667 DOI: 10.1021/acssynbio.0c00643] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Indexed: 01/22/2023]
Abstract
To successfully engineer mammalian cells for a desired purpose, multiple recombinant genes are required to be coexpressed at a specific and optimal ratio. In this study, we hypothesized that synthetic promoters varying in transcriptional activity could be used to create single multigene expression vectors coexpressing recombinant genes at a predictable relative stoichiometry. A library of 27 multigene constructs was created comprising three discrete fluorescent reporter gene transcriptional units in fixed series, each under the control of either a relatively low, medium, or high transcriptional strength synthetic promoter in every possible combination. Expression of each reporter gene was determined by absolute quantitation qRT-PCR in CHO cells. The synthetic promoters did generally function as designed within a multigene vector context; however, significant divergences from predicted promoter-mediated transcriptional activity were observed. First, expression of all three genes within a multigene vector was repressed at varying levels relative to coexpression of identical reporter genes on separate single gene vectors at equivalent gene copies. Second, gene positional effects were evident across all constructs where expression of the reporter genes in positions 2 and 3 was generally reduced relative to position 1. Finally, after accounting for general repression, synthetic promoter transcriptional activity within a local multigene vector format deviated from that expected. Taken together, our data reveal that mammalian synthetic promoters can be employed in vectors to mediate expression of multiple genes at predictable relative stoichiometries. However, empirical validation of functional performance is a necessary prerequisite, as vector and promoter design features can significantly impact performance.
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Affiliation(s)
- Yash D. Patel
- Department
of Chemical and Biological Engineering, The University of Sheffield, Mappin Street, Sheffield, S1 3JD, U.K.
| | - Adam J. Brown
- Department
of Chemical and Biological Engineering, The University of Sheffield, Mappin Street, Sheffield, S1 3JD, U.K.
| | - Jie Zhu
- Cell
Culture and Fermentation Sciences, BioPharmaceuticals Development,
R&D, AstraZeneca, Gaithersburg, Maryland 20878, United States
| | - Guglielmo Rosignoli
- Dynamic
Omics, Antibody Discovery & Protein Engineering, R&D, AstraZeneca, Cambridge, CB21 6GH, U.K.
| | - Suzanne J. Gibson
- Cell
Culture and Fermentation Sciences, BioPharmaceuticals Development,
R&D, AstraZeneca, Cambridge, CB21 6GH, U.K.
| | - Diane Hatton
- Cell
Culture and Fermentation Sciences, BioPharmaceuticals Development,
R&D, AstraZeneca, Cambridge, CB21 6GH, U.K.
| | - David C. James
- Department
of Chemical and Biological Engineering, The University of Sheffield, Mappin Street, Sheffield, S1 3JD, U.K.
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12
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Johari YB, Mercer AC, Liu Y, Brown AJ, James DC. Design of synthetic promoters for controlled expression of therapeutic genes in retinal pigment epithelial cells. Biotechnol Bioeng 2021; 118:2001-2015. [PMID: 33580508 DOI: 10.1002/bit.27713] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 02/09/2021] [Accepted: 02/11/2021] [Indexed: 11/10/2022]
Abstract
Age-related macular degeneration (AMD) associated with dysfunction of retinal pigment epithelial (RPE) cells is the most common cause of untreatable blindness. To advance gene therapy as a viable treatment for AMD there is a need for technologies that enable controlled, RPE-specific expression of therapeutic genes. Here we describe design, construction and testing of compact synthetic promoters with a pre-defined transcriptional activity and RPE cell specificity. Initial comparative informatic analyses of RPE and photoreceptor (PR) cell transcriptomic data identified conserved and overrepresented transcription factor regulatory elements (TFREs, 8-19 bp) specifically associated with transcriptionally active RPE genes. Both RPE-specific TFREs and those derived from the generically active cytomegalovirus-immediate early (CMV-IE) promoter were then screened in vitro to identify sequence elements able to control recombinant gene transcription in model induced pluripotent stem (iPS)-derived and primary human RPE cells. Two libraries of heterotypic synthetic promoters varying in predicted RPE specificity and transcriptional activity were designed de novo using combinations of up to 20 discrete TFREs in series (323-602 bp) and their transcriptional activity in model RPE cells was compared to that of the endogenous BEST1 promoter (661 bp, plus an engineered derivative) and the highly active generic CMV-IE promoter (650 bp). Synthetic promoters with a highpredicted specificity, comprised predominantly of endogenous TFREs exhibited a range of activities up to 8-fold that of the RPE-specific BEST1 gene promoter. Moreover, albeit at a lower predicted specificity, synthetic promoter transcriptional activity in model RPE cells was enhanced beyond that of the CMV-IE promoter when viral elements were utilized in combination with endogenous RPE-specific TFREs, with a reduction in promoter size of 15%. Taken together, while our data reveal an inverse relationship between synthetic promoter activity and cell-type specificity, cell context-specific control of recombinant gene transcriptional activity may be achievable.
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Affiliation(s)
- Yusuf B Johari
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield, UK
| | - Andrew C Mercer
- Research and Early Development, REGENXBIO Inc., Rockville, Maryland, USA
| | - Ye Liu
- Research and Early Development, REGENXBIO Inc., Rockville, Maryland, USA
| | - Adam J Brown
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield, UK
| | - David C James
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield, UK
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13
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Johari YB, Jaffé SRP, Scarrott JM, Johnson AO, Mozzanino T, Pohle TH, Maisuria S, Bhayat-Cammack A, Lambiase G, Brown AJ, Tee KL, Jackson PJ, Wong TS, Dickman MJ, Sargur RB, James DC. Production of trimeric SARS-CoV-2 spike protein by CHO cells for serological COVID-19 testing. Biotechnol Bioeng 2021; 118:1013-1021. [PMID: 33128388 DOI: 10.1002/bit.27615] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 10/14/2020] [Accepted: 10/27/2020] [Indexed: 12/27/2022]
Abstract
We describe scalable and cost-efficient production of full length, His-tagged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike glycoprotein trimer by Chinese hamster ovary (CHO) cells that can be used to detect SARS-CoV-2 antibodies in patient sera at high specificity and sensitivity. Transient production of spike in both human embryonic kidney (HEK) and CHO cells mediated by polyethyleneimine was increased significantly (up to 10.9-fold) by a reduction in culture temperature to 32°C to permit extended duration cultures. Based on these data GS-CHO pools stably producing spike trimer under the control of a strong synthetic promoter were cultured in hypothermic conditions with combinations of bioactive small molecules to increase yield of purified spike product 4.9-fold to 53 mg/L. Purification of recombinant spike by Ni-chelate affinity chromatography initially yielded a variety of co-eluting protein impurities identified as host cell derived by mass spectrometry, which were separated from spike trimer using a modified imidazole gradient elution. Purified CHO spike trimer antigen was used in enzyme-linked immunosorbent assay format to detect immunoglobulin G antibodies against SARS-CoV-2 in sera from patient cohorts previously tested for viral infection by polymerase chain reaction, including those who had displayed coronavirus disease 2019 (COVID-19) symptoms. The antibody assay, validated to ISO 15189 Medical Laboratories standards, exhibited a specificity of 100% and sensitivity of 92.3%. Our data show that CHO cells are a suitable host for the production of larger quantities of recombinant SARS-CoV-2 trimer which can be used as antigen for mass serological testing.
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Affiliation(s)
- Yusuf B Johari
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin St., Sheffield, UK
| | - Stephen R P Jaffé
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin St., Sheffield, UK
| | - Joseph M Scarrott
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin St., Sheffield, UK
| | - Abayomi O Johnson
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin St., Sheffield, UK
| | - Théo Mozzanino
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin St., Sheffield, UK
| | - Thilo H Pohle
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin St., Sheffield, UK
| | - Sheetal Maisuria
- Department of Immunology, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK
| | - Amina Bhayat-Cammack
- Department of Immunology, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK
| | - Giulia Lambiase
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin St., Sheffield, UK
| | - Adam J Brown
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin St., Sheffield, UK
| | - Kang Lan Tee
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin St., Sheffield, UK
| | - Philip J Jackson
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin St., Sheffield, UK
| | - Tuck Seng Wong
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin St., Sheffield, UK
| | - Mark J Dickman
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin St., Sheffield, UK
| | - Ravishankar B Sargur
- Department of Immunology, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK
| | - David C James
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin St., Sheffield, UK
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14
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McGraw CE, Peng D, Sandoval NR. Synthetic biology approaches: the next tools for improved protein production from CHO cells. Curr Opin Chem Eng 2020. [DOI: 10.1016/j.coche.2020.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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15
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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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16
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Sergeeva D, Lee GM, Nielsen LK, Grav LM. Multicopy Targeted Integration for Accelerated Development of High-Producing Chinese Hamster Ovary Cells. ACS Synth Biol 2020; 9:2546-2561. [PMID: 32835482 DOI: 10.1021/acssynbio.0c00322] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The ever-growing biopharmaceutical industry relies on the production of recombinant therapeutic proteins in Chinese hamster ovary (CHO) cells. The traditional timelines of CHO cell line development can be significantly shortened by the use of targeted gene integration (TI). However, broad use of TI has been limited due to the low specific productivity (qP) of TI-generated clones. Here, we show a 10-fold increase in the qP of therapeutic glycoproteins in CHO cells through the development and optimization of a multicopy TI method. We used a recombinase-mediated cassette exchange (RMCE) platform to investigate the effect of gene copy number, 5' and 3' gene regulatory elements, and landing pad features on qP. We evaluated the limitations of multicopy expression from a single genomic site as well as multiple genomic sites and found that a transcriptional bottleneck can appear with an increase in gene dosage. We created a dual-RMCE system for simultaneous multicopy TI in two genomic sites and generated isogenic high-producing clones with qP of 12-14 pg/cell/day and product titer close to 1 g/L in fed-batch. Our study provides an extensive characterization of the multicopy TI method and elucidates the relationship between gene copy number and protein expression in mammalian cells. Moreover, it demonstrates that TI-generated CHO cells are capable of producing therapeutic proteins at levels that can support their industrial manufacture.
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Affiliation(s)
- Daria Sergeeva
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby 2800, Denmark
| | - Gyun Min Lee
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby 2800, Denmark
- Department of Biological Sciences, KAIST, Daejeon 34141, Republic of Korea
| | - Lars Keld Nielsen
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby 2800, Denmark
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, Brisbane 4072, Australia
| | - Lise Marie Grav
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby 2800, Denmark
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17
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Abstract
Following the success of and the high demand for recombinant protein-based therapeutics during the last 25 years, the pharmaceutical industry has invested significantly in the development of novel treatments based on biologics. Mammalian cells are the major production systems for these complex biopharmaceuticals, with Chinese hamster ovary (CHO) cell lines as the most important players. Over the years, various engineering strategies and modeling approaches have been used to improve microbial production platforms, such as bacteria and yeasts, as well as to create pre-optimized chassis host strains. However, the complexity of mammalian cells curtailed the optimization of these host cells by metabolic engineering. Most of the improvements of titer and productivity were achieved by media optimization and large-scale screening of producer clones. The advances made in recent years now open the door to again consider the potential application of systems biology approaches and metabolic engineering also to CHO. The availability of a reference genome sequence, genome-scale metabolic models and the growing number of various “omics” datasets can help overcome the complexity of CHO cells and support design strategies to boost their production performance. Modular design approaches applied to engineer industrially relevant cell lines have evolved to reduce the time and effort needed for the generation of new producer cells and to allow the achievement of desired product titers and quality. Nevertheless, important steps to enable the design of a chassis platform similar to those in use in the microbial world are still missing. In this review, we highlight the importance of mammalian cellular platforms for the production of biopharmaceuticals and compare them to microbial platforms, with an emphasis on describing novel approaches and discussing still open questions that need to be resolved to reach the objective of designing enhanced modular chassis CHO cell lines.
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18
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A platform for context-specific genetic engineering of recombinant protein production by CHO cells. J Biotechnol 2020; 312:11-22. [DOI: 10.1016/j.jbiotec.2020.02.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 12/12/2019] [Accepted: 02/25/2020] [Indexed: 12/12/2022]
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19
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de Jongh RP, van Dijk AD, Julsing MK, Schaap PJ, de Ridder D. Designing Eukaryotic Gene Expression Regulation Using Machine Learning. Trends Biotechnol 2020; 38:191-201. [DOI: 10.1016/j.tibtech.2019.07.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 07/12/2019] [Accepted: 07/19/2019] [Indexed: 12/11/2022]
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20
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Chassin H, Müller M, Tigges M, Scheller L, Lang M, Fussenegger M. A modular degron library for synthetic circuits in mammalian cells. Nat Commun 2019; 10:2013. [PMID: 31043592 PMCID: PMC6494899 DOI: 10.1038/s41467-019-09974-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 04/04/2019] [Indexed: 01/26/2023] Open
Abstract
Tight control over protein degradation is a fundamental requirement for cells to respond rapidly to various stimuli and adapt to a fluctuating environment. Here we develop a versatile, easy-to-handle library of destabilizing tags (degrons) for the precise regulation of protein expression profiles in mammalian cells by modulating target protein half-lives in a predictable manner. Using the well-established tetracycline gene-regulation system as a model, we show that the dynamics of protein expression can be tuned by fusing appropriate degron tags to gene regulators. Next, we apply this degron library to tune a synthetic pulse-generating circuit in mammalian cells. With this toolbox we establish a set of pulse generators with tailored pulse lengths and magnitudes of protein expression. This methodology will prove useful in the functional roles of essential proteins, fine-tuning of gene-expression systems, and enabling a higher complexity in the design of synthetic biological systems in mammalian cells.
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Affiliation(s)
- Hélène Chassin
- 0000 0001 2156 2780grid.5801.cDepartment of Biosystems Science and Engineering, ETH Zürich, Mattenstrasse 26, CH-4058 Basel, Switzerland
| | - Marius Müller
- Cilag AG, Hochstrasse 201, CH-8200 Schaffhausen, Switzerland
| | - Marcel Tigges
- Cilag AG, Hochstrasse 201, CH-8200 Schaffhausen, Switzerland
| | - Leo Scheller
- 0000 0001 2156 2780grid.5801.cDepartment of Biosystems Science and Engineering, ETH Zürich, Mattenstrasse 26, CH-4058 Basel, Switzerland
| | - Moritz Lang
- 0000000404312247grid.33565.36Institute of Science and Technology Austria, A-3400 Klosterneuburg, Austria
| | - Martin Fussenegger
- 0000 0001 2156 2780grid.5801.cDepartment of Biosystems Science and Engineering, ETH Zürich, Mattenstrasse 26, CH-4058 Basel, Switzerland ,0000 0004 1937 0642grid.6612.3Faculty of Science, University of Basel, Mattenstrasse 26, CH-4058 Basel, Switzerland
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21
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Pristovšek N, Nallapareddy S, Grav LM, Hefzi H, Lewis NE, Rugbjerg P, Hansen HG, Lee GM, Andersen MR, Kildegaard HF. Systematic Evaluation of Site-Specific Recombinant Gene Expression for Programmable Mammalian Cell Engineering. ACS Synth Biol 2019; 8:758-774. [PMID: 30807689 DOI: 10.1021/acssynbio.8b00453] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Many branches of biology depend on stable and predictable recombinant gene expression, which has been achieved in recent years through targeted integration of the recombinant gene into defined integration sites. However, transcriptional levels of recombinant genes in characterized integration sites are controlled by multiple components of the integrated expression cassette. Lack of readily available tools has inhibited meaningful experimental investigation of the interplay between the integration site and the expression cassette components. Here we show in a systematic manner how multiple components contribute to final net expression of recombinant genes in a characterized integration site. We develop a CRISPR/Cas9-based toolbox for construction of mammalian cell lines with targeted integration of a landing pad, containing a recombinant gene under defined 5' proximal regulatory elements. Generated site-specific recombinant cell lines can be used in a streamlined recombinase-mediated cassette exchange for fast screening of different expression cassettes. Using the developed toolbox, we show that different 5' proximal regulatory elements generate distinct and robust recombinant gene expression patterns in defined integration sites of CHO cells with a wide range of transcriptional outputs. This approach facilitates the generation of user-defined and product-specific gene expression patterns for programmable mammalian cell engineering.
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Affiliation(s)
- Nuša Pristovšek
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet, Building 220, 2800 Kgs. Lyngby, Denmark
| | - Saranya Nallapareddy
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet, Building 220, 2800 Kgs. Lyngby, Denmark
| | - Lise Marie Grav
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet, Building 220, 2800 Kgs. Lyngby, Denmark
| | - Hooman Hefzi
- Departments of Pediatrics and Bioengineering, University of California, San Diego, La Jolla, California 92093, United States
- The Novo Nordisk Foundation Center for Biosustainability at the University of California, San Diego School of Medicine, La Jolla, California 92093, United States
| | - Nathan E. Lewis
- Departments of Pediatrics and Bioengineering, University of California, San Diego, La Jolla, California 92093, United States
- The Novo Nordisk Foundation Center for Biosustainability at the University of California, San Diego School of Medicine, La Jolla, California 92093, United States
| | - Peter Rugbjerg
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet, Building 220, 2800 Kgs. Lyngby, Denmark
| | - Henning Gram Hansen
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet, Building 220, 2800 Kgs. Lyngby, Denmark
| | - Gyun Min Lee
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet, Building 220, 2800 Kgs. Lyngby, Denmark
- Department of Biological Sciences, KAIST, 291 Daehak-ro,
Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Mikael Rørdam Andersen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, Building 223, 2800 Kgs. Lyngby, Denmark
| | - Helene Faustrup Kildegaard
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet, Building 220, 2800 Kgs. Lyngby, Denmark
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22
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Johari YB, Brown AJ, Alves CS, Zhou Y, Wright CM, Estes SD, Kshirsagar R, James DC. CHO genome mining for synthetic promoter design. J Biotechnol 2019; 294:1-13. [PMID: 30703471 DOI: 10.1016/j.jbiotec.2019.01.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 01/07/2019] [Accepted: 01/09/2019] [Indexed: 01/01/2023]
Abstract
Synthetic promoters are an attractive alternative for use in mammalian hosts such as CHO cells as they can be designed de novo with user-defined functionalities. In this study, we describe and validate a method for bioprocess-directed design of synthetic promoters utilizing CHO genomic sequence information. We designed promoters with two objective features, (i) constitutive high-level recombinant gene transcription, and (ii) upregulated transcription under mild hypothermia or late-stage culture. CHO genes varying in transcriptional activity were selected based on a comparative analysis of RNA-Seq transcript levels in normal and biphasic cultures in combination with estimates of mRNA half-life from published genome scale datasets. Discrete transcription factor regulatory elements (TFREs) upstream of these genes were informatically identified and functionally screened in vitro to identify a subset of TFREs with the potential to support high activity recombinant gene transcription during biphasic cell culture processes. Two libraries of heterotypic synthetic promoters with varying TFRE combinations were then designed in silico that exhibited a maximal 2.5-fold increase in transcriptional strength over the CMV-IE promoter after transient transfection into host CHO-K1 cells. A subset of synthetic promoters was then used to create stable transfectant pools using CHO-K1 cells under glutamine synthetase selection. Whilst not achieving the maximal 2.5-fold increase in productivity over stable pools harboring the CMV promoter, all stably transfected cells utilizing synthetic promoters exhibited increased reporter production - up to 1.6-fold that of cells employing CMV, both in the presence or absence of intron A immediately downstream of the promoter. The increased productivity of stably transfected cells harboring synthetic promoters was maintained during fed-batch culture, with or without a transition to mild hypothermia at the onset of stationary phase. Our data exemplify that it is important to consider both host cell and intended bioprocess contexts as design criteria in the de novo construction of synthetic genetic parts for mammalian cell engineering.
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Affiliation(s)
- Yusuf B Johari
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin St., Sheffield S1 3JD, UK
| | - Adam J Brown
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin St., Sheffield S1 3JD, UK
| | | | - Yizhou Zhou
- Cell Culture Development, Biogen Inc., Cambridge, MA 02142, USA
| | | | - Scott D Estes
- Cell Culture Development, Biogen Inc., Cambridge, MA 02142, USA
| | | | - David C James
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin St., Sheffield S1 3JD, UK.
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23
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Brown AJ, Gibson SJ, Hatton D, Arnall CL, James DC. Whole synthetic pathway engineering of recombinant protein production. Biotechnol Bioeng 2018; 116:375-387. [DOI: 10.1002/bit.26855] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 09/14/2018] [Accepted: 10/18/2018] [Indexed: 12/13/2022]
Affiliation(s)
- Adam J. Brown
- Department of Chemical and Biological EngineeringUniversity of SheffieldSheffield UK
| | | | - Diane Hatton
- Biopharmaceutical Development, MedImmuneCambridge UK
| | - Claire L. Arnall
- Department of Chemical and Biological EngineeringUniversity of SheffieldSheffield UK
| | - David C. James
- Department of Chemical and Biological EngineeringUniversity of SheffieldSheffield UK
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