1
|
Woo HJ, Kim J, Kim SM, Kim D, Moon JY, Park D, Lee JS. Context-dependent genomic locus effects on antibody production in recombinant Chinese hamster ovary cells generated through random integration. Comput Struct Biotechnol J 2024; 23:1654-1665. [PMID: 38680870 PMCID: PMC11046053 DOI: 10.1016/j.csbj.2024.04.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 03/30/2024] [Accepted: 04/07/2024] [Indexed: 05/01/2024] Open
Abstract
High-yield production of therapeutic protein using Chinese hamster ovary (CHO) cells requires stable cell line development (CLD). CLD typically uses random integration of transgenes; however, this results in clonal variation and subsequent laborious clone screening. Therefore, site-specific integration of a protein expression cassette into a desired chromosomal locus showing high transcriptional activity and stability, referred to as a hot spot, is emerging. Although positional effects are important for therapeutic protein expression, the sequence-specific mechanisms by which hotspots work are not well understood. In this study, we performed whole-genome sequencing (WGS) to locate randomly inserted vectors in the genome of recombinant CHO cells expressing high levels of monoclonal antibodies (mAbs) and experimentally validated these locations and vector compositions. The integration site was characterized by active histone marks and potential enhancer activities, and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) mediated indel mutations in the region upstream of the integration site led to a significant reduction in specific antibody productivity by up to 30%. Notably, the integration site and its core region did not function equivalently outside the native genomic context, showing a minimal effect on the increase in exogenous protein expression in the host cell line. We also observed a superior production capacity of the mAb expressing cell line compared to that of the host cell line. Collectively, this study demonstrates that developing recombinant CHO cell lines to produce therapeutic proteins at high levels requires a balance of factors including transgene configuration, genomic locus landscape, and host cell properties.
Collapse
Affiliation(s)
- Hyun Jee Woo
- Department of Molecular Science and Technology, Ajou University, Suwon 16499, Republic of Korea
| | - Jaehoon Kim
- Department of Molecular Science and Technology, Ajou University, Suwon 16499, Republic of Korea
- Molecular Science and Technology Research Center, Ajou University, Suwon 16499, Republic of Korea
| | - Seul Mi Kim
- Department of Molecular Science and Technology, Ajou University, Suwon 16499, Republic of Korea
| | - Dongwoo Kim
- Department of Molecular Science and Technology, Ajou University, Suwon 16499, Republic of Korea
| | - Jae Yun Moon
- Department of Molecular Science and Technology, Ajou University, Suwon 16499, Republic of Korea
| | - Daechan Park
- Department of Molecular Science and Technology, Ajou University, Suwon 16499, Republic of Korea
- Department of Biological Sciences, Ajou University, Suwon 16499, Republic of Korea
| | - Jae Seong Lee
- Department of Molecular Science and Technology, Ajou University, Suwon 16499, Republic of Korea
- Department of Applied Chemistry and Biological Engineering, Ajou University, Suwon 16499, Republic of Korea
| |
Collapse
|
2
|
Hamaker NK, Lee KH. High-efficiency and multilocus targeted integration in CHO cells using CRISPR-mediated donor nicking and DNA repair inhibitors. Biotechnol Bioeng 2023; 120:2419-2440. [PMID: 37039773 PMCID: PMC10524319 DOI: 10.1002/bit.28393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 03/20/2023] [Accepted: 03/24/2023] [Indexed: 04/12/2023]
Abstract
Efforts to leverage clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) for targeted genomic modifications in mammalian cells are limited by low efficiencies and heterogeneous outcomes. To aid method optimization, we developed an all-in-one reporter system, including a novel superfolder orange fluorescent protein (sfOrange), to simultaneously quantify gene disruption, site-specific integration (SSI), and random integration (RI). SSI strategies that utilize different donor plasmid formats and Cas9 nuclease variants were evaluated for targeting accuracy and efficiency in Chinese hamster ovary cells. Double-cut and double-nick donor formats significantly improved targeting accuracy by 2.3-8.3-fold and 19-22-fold, respectively, compared to standard circular donors. Notably, Cas9-mediated donor linearization was associated with increased RI events, whereas donor nicking minimized RI without sacrificing SSI efficiency and avoided low-fidelity outcomes. A screen of 10 molecules that modulate the major mammalian DNA repair pathways identified two inhibitors that further enhance targeting accuracy and efficiency to achieve SSI in 25% of transfected cells without selection. The optimized methods integrated transgene expression cassettes with 96% efficiency at a single locus and with 53%-55% efficiency at two loci simultaneously in selected clones. The CRISPR-based tools and methods developed here could inform the use of CRISPR/Cas9 in mammalian cell lines, accelerate mammalian cell line engineering, and support advanced recombinant protein production applications.
Collapse
Affiliation(s)
- Nathaniel K. Hamaker
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE, 19716, USA
| | - Kelvin H. Lee
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE, 19716, USA
- The National Institute for Innovation in Manufacturing Biopharmaceuticals (NIIMBL), University of Delaware, Newark, DE, 19713, USA
| |
Collapse
|
3
|
Kalkan AK, Palaz F, Sofija S, Elmousa N, Ledezma Y, Cachat E, Rios-Solis L. Improving recombinant protein production in CHO cells using the CRISPR-Cas system. Biotechnol Adv 2023; 64:108115. [PMID: 36758652 DOI: 10.1016/j.biotechadv.2023.108115] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 12/28/2022] [Accepted: 02/03/2023] [Indexed: 02/10/2023]
Abstract
Chinese hamster ovary (CHO) cells are among the most widely used mammalian cell lines in the biopharmaceutical industry. Therefore, it is not surprising that significant efforts have been made around the engineering of CHO cells using genetic engineering methods such as the CRISPR-Cas system. In this review, we summarize key recent studies that have used different CRISPR-Cas systems such as Cas9, Cas13 or dCas9 fused with effector domains to improve recombinant protein (r-protein) production in CHO cells. Here, every relevant stage of production was considered, underscoring the advantages and limitations of these systems, as well as discussing their bottlenecks and probable solutions. A special emphasis was given on how these systems could disrupt and/or regulate genes related to glycan composition, which has relevant effects over r-protein properties and in vivo activity. Furthermore, the related promising future applications of CRISPR to achieve a tunable, reversible, or highly stable editing of CHO cells are discussed. Overall, the studies covered in this review show that despite the complexity of mammalian cells, the synthetic biology community has developed many mature strategies to improve r-protein production using CHO cells. In this regard, CRISPR-Cas technology clearly provides efficient and flexible genetic manipulation and allows for the generation of more productive CHO cell lines, leading to more cost-efficient production of biopharmaceuticals, however, there is still a need for many emerging techniques in CRISPR to be reported in CHO cells; therefore, more research in these cells is needed to realize the full potential of this technology.
Collapse
Affiliation(s)
- Ali Kerem Kalkan
- Department of Bioengineering and Imperial College Centre for Synthetic Biology, Imperial College London, London, UK; Environmental Engineering Department, Gebze Technical University, Turkey
| | - Fahreddin Palaz
- Faculty of Medicine, Hacettepe University, Ankara 06100, Turkey
| | - Semeniuk Sofija
- Centre for Engineering Biology, University of Edinburgh, Edinburgh EH9 3BF, UK; Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Nada Elmousa
- Institute for Bioengineering, School of Engineering, University of Edinburgh, Edinburgh EH9 3DW, UK
| | - Yuri Ledezma
- Institute for Bioengineering, School of Engineering, University of Edinburgh, Edinburgh EH9 3DW, UK; Biology Department, Faculty of Pure and Natural Sciences, Universidad Mayor de San Andrés, Bolivia
| | - Elise Cachat
- Centre for Engineering Biology, University of Edinburgh, Edinburgh EH9 3BF, UK; Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences University of Edinburgh, Edinburgh EH9 3BF, UK; UK Centre for Mammalian Synthetic Biology, University of Edinburgh, Edinburgh EH8 9YL, UK
| | - Leonardo Rios-Solis
- Centre for Engineering Biology, University of Edinburgh, Edinburgh EH9 3BF, UK; Institute for Bioengineering, School of Engineering, University of Edinburgh, Edinburgh EH9 3DW, UK; School of Natural and Environmental Sciences, Molecular Biology and Biotechnology Division, Newcastle University, Newcastle Upon Tyne, NE1 7RU, UK.
| |
Collapse
|
4
|
Amiri S, Adibzadeh S, Ghanbari S, Rahmani B, Kheirandish MH, Farokhi-Fard A, Dastjerdeh MS, Davami F. CRISPR-interceded CHO cell line development approaches. Biotechnol Bioeng 2023; 120:865-902. [PMID: 36597180 DOI: 10.1002/bit.28329] [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: 05/06/2022] [Revised: 11/28/2022] [Accepted: 01/02/2023] [Indexed: 01/05/2023]
Abstract
For industrial production of recombinant protein biopharmaceuticals, Chinese hamster ovary (CHO) cells represent the most widely adopted host cell system, owing to their capacity to produce high-quality biologics with human-like posttranslational modifications. As opposed to random integration, targeted genome editing in genomic safe harbor sites has offered CHO cell line engineering a new perspective, ensuring production consistency in long-term culture and high biotherapeutic expression levels. Corresponding the remarkable advancements in knowledge of CRISPR-Cas systems, the use of CRISPR-Cas technology along with the donor design strategies has been pushed into increasing novel scenarios in cell line engineering, allowing scientists to modify mammalian genomes such as CHO cell line quickly, readily, and efficiently. Depending on the strategies and production requirements, the gene of interest can also be incorporated at single or multiple loci. This review will give a gist of all the most fundamental recent advancements in CHO cell line development, such as different cell line engineering approaches along with donor design strategies for targeted integration of the desired construct into genomic hot spots, which could ultimately lead to the fast-track product development process with consistent, improved product yield and quality.
Collapse
Affiliation(s)
- Shahin Amiri
- Department of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Setare Adibzadeh
- Department of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Samaneh Ghanbari
- Department of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Behnaz Rahmani
- Department of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Mohammad H Kheirandish
- Department of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
- Department of Medical Biotechnology, School of Advanced Technologies, Tehran University of Medical Sciences, Tehran, Iran
| | - Aref Farokhi-Fard
- Department of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Mansoureh S Dastjerdeh
- Department of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Fatemeh Davami
- Department of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| |
Collapse
|
5
|
Rahimi A, Karimipoor M, Mahdian R, Alipour A, Hosseini S, Kaghazian H, Abbasi A, Shahsavarani H, Shokrgozar MA. Targeting Caspase-3 Gene in rCHO Cell Line by CRISPR/Cas9 Editing Tool and Its Effect on Protein Production in Manipulated Cell Line. IRANIAN JOURNAL OF PHARMACEUTICAL RESEARCH : IJPR 2022; 21:e130236. [PMID: 36915405 PMCID: PMC10007989 DOI: 10.5812/ijpr-130236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 11/19/2022] [Accepted: 12/12/2022] [Indexed: 03/06/2023]
Abstract
Background Chinese hamster ovary (CHO) cells are the widely used mammalian cell host for biopharmaceutical manufacturing. During cell cultures, CHO cells lose viability mainly from apoptosis. Inhibiting cell death is useful because prolonging cell lifespans can direct to more productive cell culture systems for biotechnology requests. Objectives This study exploited a CRISPR/Cas9 technology to generate site-specific gene disruptions in the caspase-3 gene in the apoptosis pathway, which acts as an apoptotic regulator to extend cell viability in the CHO cell line. Methods The STRING database was used to identify the key pro-apoptotic genes to be modified by CRISPR/Cas9 system. The guide RNAs targeting the caspase-3 gene were designed, and vectors containing sgRNA and Cas9 were transfected into CHO cells that expressed erythropoietin as a heterologous protein. Indel formation was investigated by DNA sequencing. Caspase-3 expression was quantified by real-time PCR and western blot. The effect of editing the caspase-3 gene on the inhibition of apoptosis was also investigated by induction of apoptosis in manipulated cell lines by oleuropein. Finally, the erythropoietin production in the edited cells was compared to the control cells. Results The caspase-3 manipulation significantly prolongation of the cell viability and decreased the caspase-3 expression level of protein in manipulated CHO cells (more than 6-fold, P-value < 0.0001). Manipulated cells displayed higher threshold tolerance to apoptosis compared to the control cells when they were induced by oleuropein. They show a higher IC50 than the control ones (7271 µM/mL Vs. 5741 µM/mL). They also show a higher proliferation rate than the control cells in the presence of an apoptosis inducer (P-value < 0.0001). Furthermore, manipulated cell lines significantly produce more recombinant protein in the presence of 2,000 µM oleuropein compared to the control ones (P-value = 0.0021). Conclusions We understood that CRISPR/Cas9 could be effectively applied to suppress the expression of the caspase-3 gene and rescue CHO cells from apoptosis induced by cell stress and metabolites. The CRISPR/Cas9 system-assisted caspase-3 gene ablation can potentially increase erythropoietin yield in CHO cells.
Collapse
Affiliation(s)
- Amirabbas Rahimi
- Laboratory of Regenerative Medicine and Biomedical Innovations, Department of National Cell Bank, Pasteur Institute of Iran, Tehran, Iran
- Department of Molecular Medicine, Pasteur Institute of Iran, Tehran, Iran
| | - Morteza Karimipoor
- Department of Molecular Medicine, Pasteur Institute of Iran, Tehran, Iran
| | - Reza Mahdian
- Department of Molecular Medicine, Pasteur Institute of Iran, Tehran, Iran
| | - Atefeh Alipour
- Department of Nano-Biotechnology, Pasteur Institute of Iran, Tehran, Iran
| | - Sadi Hosseini
- Laboratory of Regenerative Medicine and Biomedical Innovations, Department of National Cell Bank, Pasteur Institute of Iran, Tehran, Iran
| | - Hooman Kaghazian
- Department of Research & Development, Production & Research Complex, Pasteur Institute of Iran, Tehran, Iran
| | - Abdolrahim Abbasi
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Hosein Shahsavarani
- Department of Cell and Molecular Biology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran
- Corresponding Author: Department of Cell and Molecular Biology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran.
| | - Mohammad Ali Shokrgozar
- Laboratory of Regenerative Medicine and Biomedical Innovations, Department of National Cell Bank, Pasteur Institute of Iran, Tehran, Iran
- Corresponding Author: Laboratory of Regenerative Medicine and Biomedical Innovations, Department of National Cell Bank, Pasteur Institute of Iran, 13169-43551, Tehran, Iran.
| |
Collapse
|
6
|
Shin SW, Kim D, Lee JS. Controlling Ratios of Plasmid-Based Double Cut Donor and CRISPR/Cas9 Components to Enhance Targeted Integration of Transgenes in Chinese Hamster Ovary Cells. Int J Mol Sci 2021; 22:ijms22052407. [PMID: 33673701 PMCID: PMC7957797 DOI: 10.3390/ijms22052407] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 02/23/2021] [Accepted: 02/24/2021] [Indexed: 12/20/2022] Open
Abstract
Chinese hamster ovary (CHO) cells are the most valuable expression host for the commercial production of biotherapeutics. Recent trends in recombinant CHO cell-line development have focused on the site-specific integration of transgenes encoding recombinant proteins over random integration. However, the low efficiency of homology-directed repair upon transfection of Cas9, single-guide RNA (sgRNA), and the donor template has limited its feasibility. Previously, we demonstrated that a double-cut donor (DCD) system enables highly efficient CRISPR/Cas9-mediated targeted integration (TI) in CHO cells. Here, we describe several CRISPR/Cas9 vector systems based on DCD templates using a promoter trap-based TI monitoring cell line. Among them, a multi-component (MC) system consisting of an sgRNA/DCD vector and Cas9 expression vector showed an approximate 1.5-fold increase in knock-in (KI) efficiency compared to the previous DCD system, when a systematically optimized relative ratio of sgRNA/DCD and Cas9 vector was applied. Our optimization efforts revealed that concurrently increasing sgRNA and DCD components relative to Cas9 correlated positively with KI efficiency at a single KI site. Furthermore, we explored component bottlenecks, such as effects of sgRNA components and applicability of the MC system on simultaneous double KI. Taken together, we improved the DCD vector design by tailoring plasmid constructs and relative component ratios, and this system can be widely used in the TI strategy of transgenes, particularly in CHO cell line development and engineering.
Collapse
|
7
|
Kwak JM, Lee Y, Shin SW, Lee JS. Hydroxyurea selection for enhancement of homology-directed targeted integration of transgenes in CHO cells. N Biotechnol 2021; 62:26-31. [PMID: 33484867 DOI: 10.1016/j.nbt.2021.01.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 01/06/2021] [Accepted: 01/17/2021] [Indexed: 12/23/2022]
Abstract
Site-specific integration via genome editing technologies has been implemented in Chinese hamster ovary (CHO) cells for predictable and efficient cell line development and engineering. Various strategies have been employed to enhance knock-in (KI) efficiency for precise homology-directed repair (HDR)-mediated targeted integration of transgenes in CHO cells. Given the cell cycle-dependent regulation of the DNA damage repair pathway, cell cycle synchronization to the HDR-favored S/G2 phase has been successfully utilized in mammalian cells, but the effect is limited in CHO cells. Here, we describe a cell cycle enrichment method to increase HDR-mediated KI efficiency in CHO cells. Existing G1 cell cycle synchronization methods showed transient cell cycle arrest and did not improve KI efficiency. Rather than cell cycle arrest with a high concentration of chemicals followed by a release step, cells were incubated in the presence of a lower concentration of hydroxyurea (HU) to enrich cells in the S phase. HU selection allowed for robust S phase enrichment of CHO cells by up to 70 % and maintained cell viability. This short-term selection resulted in improved KI efficiency by 1.2-1.5 fold compared with cells in the control condition. Overall, this approach serves as a simple and effective strategy for enhancement of site-specific genome engineering in CHO cells.
Collapse
Affiliation(s)
- Jin Myeong Kwak
- Department of Applied Chemistry and Biological Engineering, Ajou University, Suwon, 16499, Republic of Korea; Department of Molecular Science and Technology, Ajou University, Suwon, 16499, Republic of Korea
| | - Youngsik Lee
- Department of Molecular Science and Technology, Ajou University, Suwon, 16499, Republic of Korea
| | - Sung Wook Shin
- Department of Molecular Science and Technology, Ajou University, Suwon, 16499, Republic of Korea
| | - Jae Seong Lee
- Department of Applied Chemistry and Biological Engineering, Ajou University, Suwon, 16499, Republic of Korea; Department of Molecular Science and Technology, Ajou University, Suwon, 16499, Republic of Korea.
| |
Collapse
|
8
|
Lau CH, Tin C, Suh Y. CRISPR-based strategies for targeted transgene knock-in and gene correction. Fac Rev 2020; 9:20. [PMID: 33659952 PMCID: PMC7886068 DOI: 10.12703/r/9-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The last few years have seen tremendous advances in CRISPR-mediated genome editing. Great efforts have been made to improve the efficiency, specificity, editing window, and targeting scope of CRISPR/Cas9-mediated transgene knock-in and gene correction. In this article, we comprehensively review recent progress in CRISPR-based strategies for targeted transgene knock-in and gene correction in both homology-dependent and homology-independent approaches. We cover homology-directed repair (HDR), synthesis-dependent strand annealing (SDSA), microhomology-mediated end joining (MMEJ), and homology-mediated end joining (HMEJ) pathways for a homology-dependent strategy and alternative DNA repair pathways such as non-homologous end joining (NHEJ), base excision repair (BER), and mismatch repair (MMR) for a homology-independent strategy. We also discuss base editing and prime editing that enable direct conversion of nucleotides in genomic DNA without damaging the DNA or requiring donor DNA. Notably, we illustrate the key mechanisms and design principles for each strategy, providing design guidelines for multiplex, flexible, scarless gene insertion and replacement at high efficiency and specificity. In addition, we highlight next-generation base editors that provide higher editing efficiency, fewer undesired by-products, and broader targeting scope.
Collapse
Affiliation(s)
- Cia-Hin Lau
- Department of Biomedical Engineering, Academic 1, 83 Tat Chee Avenue, City University of Hong Kong, Hong Kong
| | - Chung Tin
- Department of Biomedical Engineering, Academic 1, 83 Tat Chee Avenue, City University of Hong Kong, Hong Kong
| | - Yousin Suh
- Department of Obstetrics and Gynecology, Columbia University Irving Medical Center, 630 West 168th Street, New York, NY 10032, USA
- Department of Genetics and Development, Columbia University Irving Medical Center, 630 West 168th Street, New York, NY 10032, USA
| |
Collapse
|
9
|
Shin SW, Lee JS. CHO Cell Line Development and Engineering via Site-specific Integration: Challenges and Opportunities. BIOTECHNOL BIOPROC E 2020. [DOI: 10.1007/s12257-020-0093-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
10
|
Kiesslich S, Kamen AA. Vero cell upstream bioprocess development for the production of viral vectors and vaccines. Biotechnol Adv 2020; 44:107608. [PMID: 32768520 PMCID: PMC7405825 DOI: 10.1016/j.biotechadv.2020.107608] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 07/28/2020] [Accepted: 07/30/2020] [Indexed: 12/13/2022]
Abstract
The Vero cell line is considered the most used continuous cell line for the production of viral vectors and vaccines. Historically, it is the first cell line that was approved by the WHO for the production of human vaccines. Comprehensive experimental data on the production of many viruses using the Vero cell line can be found in the literature. However, the vast majority of these processes is relying on the microcarrier technology. While this system is established for the large-scale manufacturing of viral vaccine, it is still quite complex and labor intensive. Moreover, scale-up remains difficult and is limited by the surface area given by the carriers. To overcome these and other drawbacks and to establish more efficient manufacturing processes, it is a priority to further develop the Vero cell platform by applying novel bioprocess technologies. Especially in times like the current COVID-19 pandemic, advanced and scalable platform technologies could provide more efficient and cost-effective solutions to meet the global vaccine demand. Herein, we review the prevailing literature on Vero cell bioprocess development for the production of viral vectors and vaccines with the aim to assess the recent advances in bioprocess development. We critically underline the need for further research activities and describe bottlenecks to improve the Vero cell platform by taking advantage of recent developments in the cell culture engineering field.
Collapse
Affiliation(s)
- Sascha Kiesslich
- Department of Bioengineering, McGill University, 817 Sherbrooke Street West, Montreal, Quebec H3A 0C3, Canada
| | - Amine A Kamen
- Department of Bioengineering, McGill University, 817 Sherbrooke Street West, Montreal, Quebec H3A 0C3, Canada.
| |
Collapse
|
11
|
Hamaker NK, Lee KH. A Site-Specific Integration Reporter System That Enables Rapid Evaluation of CRISPR/Cas9-Mediated Genome Editing Strategies in CHO Cells. Biotechnol J 2020; 15:e2000057. [PMID: 32500600 DOI: 10.1002/biot.202000057] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 05/09/2020] [Indexed: 12/12/2022]
Abstract
Targeted gene knockout and site-specific integration (SSI) are powerful genome editing techniques to improve the development of industrially relevant Chinese hamster ovary (CHO) cell lines. However, past efforts to perform SSI in CHO cells are characterized by low efficiencies. Moreover, numerous strategies proposed to boost SSI efficiency in mammalian cell types have yet to be evaluated head to head or in combination to appreciably boost efficiencies in CHO. To enable systematic and rapid optimization of genome editing methods, the SSIGNAL (site-specific integration and genome alteration) reporter system is developed. This tool can analyze CRISPR (clustered regularly interspaced palindromic repeats)/Cas9 (CRISPR-associated protein 9)-mediated disruption activity alone or in conjunction with SSI efficiency. The reporter system uses green and red dual-fluorescence signals to indicate genotype states within four days following transfection, facilitating rapid data acquisition via standard flow cytometry instrumentation. In addition to describing the design and development of the system, two of its applications are demonstrated by first comparing transfection conditions to maximize CRISPR/Cas9 activity and subsequently assessing the efficiency of several promising SSI strategies. Due to its sensitivity and versatility, the SSIGNAL reporter system may serve as a tool to advance genome editing technology.
Collapse
Affiliation(s)
- Nathaniel K Hamaker
- Biopharmaceutical Innovation Center, Newark, DE, 19713, USA.,Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE, 19716, USA
| | - Kelvin H Lee
- Biopharmaceutical Innovation Center, Newark, DE, 19713, USA.,Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE, 19716, USA
| |
Collapse
|