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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.
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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
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Bayat H, Farahmand F, Tabatabaee SH, Shams F, Mohammadian O, Pourmaleki E, Rahimpour A. Evaluation of the paired-Cas9 nickase and RNA-guided FokI genome editing tools in precise integration of an anti-CD52 bicistronic monoclonal antibody expression construct at Chinese hamster ovary cells 18S rDNA locus. Protein Expr Purif 2024; 217:106445. [PMID: 38342386 DOI: 10.1016/j.pep.2024.106445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 01/08/2024] [Accepted: 02/08/2024] [Indexed: 02/13/2024]
Abstract
INTRODUCTION The aim of this study was to compare two CRISPR/Cas9-based orthogonal strategies, paired-Cas9 nickase (paired-Cas9n) and RNA-guided FokI (RFN), in targeting 18S rDNA locus in Chinese hamster ovary (CHO) cells and precisely integrating a bicistronic anti-CD52 monoclonal antibody (mAb) expression cassette into this locus. METHODS T7E1 and high-resolution melt (HRM) assays were used to compare the ability of mentioned systems in inducing double-strand break (DSB) at the target site. Moreover, 5'- and 3'-junction polymerase chain reactions (PCR) were used to verify the accuracy of the targeted integration of the mAb expression cassette into the 18S rDNA locus. Finally, anti-CD52 mAb gene copy number was measured and, its expression was analyzed using ELISA and western blot assays. RESULTS Our results indicated that both paired-Cas9n and RFN induced DSB at the target site albeit RFN performance was slightly more efficient in HRM analysis. We also confirmed that the anti-CD52 mAb cassette was accurately integrated at the 18S rDNA locus and the mAb was expressed successfully in CHO cells. CONCLUSION Taken together, our findings elucidated that both paired-Cas9n and RFN genome editing tools are promising in targeting the 18S rDNA locus. Site specific integration of the bicistronic anti-CD52 mAb expression cassette at this locus in the CHO-K1 cells was obtained, using RFN. Moreover, proper expression of the anti-CD52 mAb at the 18S rDNA target site can be achieved using the bicistronic internal ribosome entry site (IRES)-based vector system.
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Affiliation(s)
- Hadi Bayat
- Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Faranak Farahmand
- Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Sayed Hassan Tabatabaee
- Department of Life Science Engineering, Faculty of New Sciences and Technology, University of Tehran, Tehran, Iran
| | - Forough Shams
- Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Omid Mohammadian
- Department of Clinical Biochemistry, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Es'hagh Pourmaleki
- Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Azam Rahimpour
- Medical Nanotechnology and Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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Rahman MR, Kawabe Y, Suzuki K, Chen S, Amamoto Y, Kamihira M. Inducible transgene expression in CHO cells using an artificial transcriptional activator with estrogen-binding domain. Biotechnol J 2024; 19:e2300362. [PMID: 38161242 DOI: 10.1002/biot.202300362] [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: 07/26/2023] [Revised: 12/04/2023] [Accepted: 12/21/2023] [Indexed: 01/03/2024]
Abstract
Biopharmaceuticals, including therapeutic antibodies, are rapidly growing products in the pharmaceutical market. Mammalian cells, such as Chinese hamster ovary (CHO) cells, are widely used as production hosts because recombinant antibodies require complex three-dimensional structures modified with sugar chains. Recombinant protein production using mammalian cells is generally performed with cell growth. In this study, we developed a technology that controls cell growth and recombinant protein production to induce recombinant protein production with predetermined timing. Expression of green fluorescent protein (GFP) gene and a single-chain antibody fused with the Fc-region of the human IgG1 (scFv-Fc) gene can be induced and mediated by the estrogen receptor-based artificial transcription factor Gal4-ERT2-VP16 and corresponding inducer drugs. We generated CHO cells using an artificial gene expression system. The addition of various concentrations of inducer drugs to the culture medium allowed control of proliferation and transgene expression of the engineered CHO cells. Use of 4-hydroxytamoxifen, an antagonist of estrogen, as an inducing agent yielded high gene expression at a concentration more than 10-fold lower than that of β-estradiol. When scFv-Fc was produced under inducing conditions, continuous production was possible for more than 2 weeks while maintaining high specific productivity (57 pg cell-1 day-1 ). This artificial gene expression control system that utilizes the estrogen response of estrogen receptors can be an effective method for inducible production of biopharmaceuticals.
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Affiliation(s)
- Md Rashidur Rahman
- Department of Chemical Engineering, Faculty of Engineering, Kyushu University, Fukuoka, Japan
| | - Yoshinori Kawabe
- Department of Chemical Engineering, Faculty of Engineering, Kyushu University, Fukuoka, Japan
| | - Kozumi Suzuki
- Department of Chemical Engineering, Faculty of Engineering, Kyushu University, Fukuoka, Japan
| | - Satoshi Chen
- Department of Chemical Engineering, Faculty of Engineering, Kyushu University, Fukuoka, Japan
| | - Yuki Amamoto
- Department of Chemical Engineering, Faculty of Engineering, Kyushu University, Fukuoka, Japan
| | - Masamichi Kamihira
- Department of Chemical Engineering, Faculty of Engineering, Kyushu University, Fukuoka, Japan
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Yamano-Adachi N, Hata H, Nakanishi Y, Omasa T. Effects of genome instability of parental CHO cell clones on chromosome number distribution and recombinant protein production in parent-derived subclones. J Biosci Bioeng 2024; 137:54-63. [PMID: 37981489 DOI: 10.1016/j.jbiosc.2023.10.001] [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: 08/09/2023] [Revised: 10/11/2023] [Accepted: 10/16/2023] [Indexed: 11/21/2023]
Abstract
Chinese hamster ovary (CHO) cells are the de facto standard host cells for biopharmaceuticals, and there is great interest in developing methods for constructing stable production cell lines. In this study, clones with a wide chromosome number distribution were selected from isolated antibody-producing strains, and subclones obtained from these clones were evaluated. The transgene copy number varied between the subclones. Even among subclones with similar copy numbers of antibody genes and maintained insertion sites, clones with different productivity were generated. Although the chromosome number distribution differed between these subclones, there was no correlation between the variability in chromosome number after cloning (genome instability) and productivity. Most of the subclones obtained from a parental strain with a wide chromosome number had the same wide chromosome number distribution as the parental strain. Less frequently, cells with less variation (remaining in one distribution) in chromosome number were isolated from cells with a wide chromosome number distribution, from which subclones with less variation in chromosome number were obtained when subcloning was performed again. These results imply that the characteristics of clones with chromosomal instability are inherited by subclones, and thus provide a better understanding of cell line stability/instability.
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Affiliation(s)
- Noriko Yamano-Adachi
- Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan; Institute for Open and Transdisciplinary Research Initiatives, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Hirofumi Hata
- Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Yuto Nakanishi
- Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Takeshi Omasa
- Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan; Institute for Open and Transdisciplinary Research Initiatives, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
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Liu H, Zhang W, Xie L, Hu Y. Identification of a New Integration Site and Study on Site-Specific Integration in CHO-K1 Cells. Pharmaceuticals (Basel) 2023; 17:8. [PMID: 38275994 PMCID: PMC10819697 DOI: 10.3390/ph17010008] [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: 11/29/2023] [Revised: 12/15/2023] [Accepted: 12/18/2023] [Indexed: 01/27/2024] Open
Abstract
Site-specific integration is an important approach used to address the problem of unstable cell lines in industry. In this study, we observed a reduction in the gene copy number and antibody production in a CHOK1 cell line BA03 capable of high antibody expression. We identified a new integration site named locus 7 in the intron region of the parva gene through sequencing, FISH, and genome walking. We demonstrate that the integration of the exogenous gene at this locus does not affect the transcription of the parva and, therefore, has a minimal impact on cell growth. We designed sgRNA and donor vectors to integrate the etanercept-coding gene into locus 7 and obtained a cell line, SSI-4. We performed a passaged stability study on SSI-4 and proved the possibility of the stable, site-specific integration of exogenous genes at this locus in terms of integration site, copy number, expression level, and cell growth. In summary, our study has identified a new integration site suitable for site-specific integration, which lays the foundation for the subsequent development of site-specific integration cell lines.
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Affiliation(s)
| | | | - Liping Xie
- Department of Biology, China State Institute of Pharmaceutical Industry, Shanghai 201203, China; (H.L.); (W.Z.)
| | - Youjia Hu
- Department of Biology, China State Institute of Pharmaceutical Industry, Shanghai 201203, China; (H.L.); (W.Z.)
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Huang Z, Habib A, Zhao G, Ding X. CRISPR-Cas9 Mediated Stable Expression of Exogenous Proteins in the CHO Cell Line through Site-Specific Integration. Int J Mol Sci 2023; 24:16767. [PMID: 38069090 PMCID: PMC10706275 DOI: 10.3390/ijms242316767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 11/22/2023] [Accepted: 11/24/2023] [Indexed: 12/18/2023] Open
Abstract
Chinese hamster ovary (CHO) cells are a popular choice in biopharmaceuticals because of their beneficial traits, including high-density suspension culture, safety, and exogenously produced proteins that closely resemble natural proteins. Nevertheless, a decline in the expression of exogenous proteins is noted as culture time progresses. This is a consequence of foreign gene recombination into chromosomes by random integration. The current investigation employs CRISPR-Cas9 technology to integrate foreign genes into a particular chromosomal location for sustained expression. Results demonstrate the successful integration of enhanced green fluorescent protein (EGFP) and human serum albumin (HSA) near base 434814407 on chromosome NC_048595.1 of CHO-K1 cells. Over 60 successive passages, monoclonal cell lines were produced that consistently expressed all relevant external proteins without discernible variation in expression levels. In conclusion, the CHO-K1 cell locus, NC_048595.1, proves an advantageous locus for stable exogenous protein expression. This study provides a viable approach to establishing a CHO cell line capable of enduring reliable exogenous protein expression.
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Affiliation(s)
- Zhipeng Huang
- Collaborative Innovation Center for Genetics and Development, State Key Laboratory of Genetic Engineering, Department of Microbiology, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Arslan Habib
- Laboratory of Molecular Immunology, State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Guoping Zhao
- Collaborative Innovation Center for Genetics and Development, State Key Laboratory of Genetic Engineering, Department of Microbiology, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Xiaoming Ding
- Collaborative Innovation Center for Genetics and Development, State Key Laboratory of Genetic Engineering, Department of Microbiology, School of Life Sciences, Fudan University, Shanghai 200438, China
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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.
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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.
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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.
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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
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Targeting DNA repair pathways with B02 and Nocodazole small molecules to improve CRIS-PITCh mediated cassette integration in CHO-K1 cells. Sci Rep 2023; 13:3116. [PMID: 36813818 PMCID: PMC9947112 DOI: 10.1038/s41598-023-29863-8] [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: 09/21/2022] [Accepted: 02/11/2023] [Indexed: 02/24/2023] Open
Abstract
CRISPR-mediated integration could be used to develop the recombinant CHO (rCHO) cells by knock-in into the hotspot loci. However, low HDR efficiency besides the complex donor design is the main barrier for achieving so. The recently introduced MMEJ-mediated CRISPR system (CRIS-PITCh) uses a donor with short homology arms, being linearized in the cells via two sgRNAs. In this paper, a new approach to improve CRIS-PITCh knock-in efficiency by employing small molecules was investigated. Two small molecules, B02, a Rad51 inhibitor, and Nocodazole, a G2/M cell cycle synchronizer, were used to target the S100A hotspot site using a bxb1 recombinase comprised landing pad in CHO-K1 cells. Following transfection, the CHO-K1 cells were treated with the optimum concentration of one or combination of small molecules, being determined by the cell viability or flow cytometric cell cycle assay. Stable cell lines were generated and the single-cell clones were achieved by the clonal selection procedure. The finding showed that B02 improved the PITCh-mediated integration approximately twofold. In the case of Nocodazole treatment, the improvement was even more significant, up to 2.4-fold. However, the combinatorial effects of both molecules were not substantial. Moreover, according to the copy number and out-out PCR analyses, 5 and 6 of 20 clonal cells exhibited mono-allelic integration in Nocodazole and B02 groups, respectively. The results of the present study as the first attempt to enhance the CHO platform generation by exploiting two small molecules in the CRIS-PITCh system could be used in future researches to establish rCHO clones.
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A comprehensive evaluation of stable expression "hot spot" in the ScltI gene of Chinese hamster ovary cells. Appl Microbiol Biotechnol 2023; 107:1299-1309. [PMID: 36707420 DOI: 10.1007/s00253-023-12383-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 01/06/2023] [Accepted: 01/09/2023] [Indexed: 01/29/2023]
Abstract
The Chinese hamster ovary (CHO) cell is the most widely used biopharmaceutical expression system, but its long-term expression is unstable. This issue can be effectively addressed by site-specific integration of exogenous genes into the genome. Therefore, exogenous protein sites with stable expression in the CHO cell genome must be identified. CRISPR/Cas9 technology was used in this study to integrate various exogenous genes into the ScltI site as a "hot spot" at the CHO-K1 cell genome NW_003614095.1, and the stability and adaptability of exogenous genes expressed at the site were investigated. Flow cytometry sorting technology was used to obtain positive monoclonal cell lines that expressed either intracellular protein green fluorescent protein (EGFP) or secretory protein human serum albumin (HSA). For 60 passages, the positive monoclonal cell lines' cell growth cycles and exogenous protein expression were both observed. The results demonstrated that integrating the gene encoding exogenous proteins into the ScltI site had no effect on cell growth. The fluorescence intensity of EGFP was similar after 60 passages, and the expression of HSA increased slightly. Additionally, the super-monomeric protein VWF hydrolase (ADAMTS13) (190 kDa), human coagulation factor VII (FVII) (55 kDa), and interferon α2b (12 kDa) were integrated into the ScltI site for expression. In conclusion, the site located in the first exon of the ScltI gene within the CHO-K1 cell genome NW_003614095.1 is an ideal "hot spot" for the stable expression of various exogenous proteins. KEY POINTS: • The site-specific integration strategy of an exogenous gene in CHO cells was established for the ScltI site. • The genes for EGFP and HSA were site-directed integrated and stably expressed at the ScltI site. • The ScltI site fulfills the expression of exogenous proteins of different molecular weight sizes (15-190 kDa).
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11
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Targeted integration in CHO cells using CRIS-PITCh/Bxb1 recombinase-mediated cassette exchange hybrid system. Appl Microbiol Biotechnol 2023; 107:769-783. [PMID: 36536089 PMCID: PMC9763083 DOI: 10.1007/s00253-022-12322-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 11/27/2022] [Accepted: 11/30/2022] [Indexed: 12/24/2022]
Abstract
Recombinant Chinese hamster ovary (CHO) cell line development for complex biotherapeutic production is conventionally based on the random integration (RI) approach. Due to the lack of control over the integration site and copy number, RI-generated cell pools are always coupled with rigorous screening to find clones that satisfy requirements for production titers, quality, and stability. Targeted integration into a well-defined genomic site has been suggested as a possible strategy to mitigate the drawbacks associated with RI. In this work, we employed the CRISPR-mediated precise integration into target chromosome (CRIS-PITCh) system in combination with the Bxb1 recombinase-mediated cassette exchange (RMCE) system to generate an isogenic transgene-expressing cell line. We successfully utilized the CRIS-PITCh system to target a 2.6 kb Bxb1 landing pad with homology arms as short as 30 bp into the upstream region of the S100A gene cluster, achieving a targeting efficiency of 10.4%. The platform cell line (PCL) with a single copy of the landing pad was then employed for the Bxb1-mediated landing pad exchange with an EGFP encoding cassette to prove its functionality. Finally, to accomplish the main goal of our cell line development method, the PCL was applied for the expression of a secretory glycoprotein, human recombinant soluble angiotensin-converting enzyme 2 (hrsACE2). Taken together, on-target, single-copy, and stable expression of the transgene over long-term cultivation demonstrated our CRIS-PITCh/RMCE hybrid approach might possibly improve the cell line development process in terms of timeline, specificity, and stability. KEY POINTS: • CRIS-PITCh system is an efficient method for single copy targeted integration of the landing pad and generation of platform cell line • Upstream region of the S100A gene cluster of CHO-K1 is retargetable by recombinase-mediated cassette exchange (RMCE) approach and provides a stable expression of the transgene • CRIS-PITCh/Bxb1 RMCE hybrid system has the potential to overcome some limitations of the random integration approach and accelerate the cell line development timeline.
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12
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Hertel O, Neuss A, Busche T, Brandt D, Kalinowski J, Bahnemann J, Noll T. Enhancing stability of recombinant CHO cells by CRISPR/Cas9-mediated site-specific integration into regions with distinct histone modifications. Front Bioeng Biotechnol 2022; 10:1010719. [PMID: 36312557 PMCID: PMC9606416 DOI: 10.3389/fbioe.2022.1010719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 09/30/2022] [Indexed: 11/24/2022] Open
Abstract
Chinese hamster ovary (CHO) cells are the most important platform for producing biotherapeutics. Random integration of a transgene into epigenetically instable regions of the genome results in silencing of the gene of interest and loss of productivity during upstream processing. Therefore, cost- and time-intensive long-term stability studies must be performed. Site-specific integration into safe harbors is a strategy to overcome these limitations of conventional cell line design. Recent publications predict safe harbors in CHO cells based on omics data sets or by learning from random integrations, but those predictions remain theory. In this study, we established a CRISPR/Cas9-mediated site-specific integration strategy based on ChIP-seq data to improve stability of recombinant CHO cells. Therefore, a ChIP experiment from the exponential and stationary growth phase of a fed-batch cultivation of CHO-K1 cells yielded 709 potentially stable integration sites. The reporter gene eGFP was integrated into three regions harboring specific modifications by CRISPR/Cas9. Targeted Cas9 nanopore sequencing showed site-specific integration in all 3 cell pools with a specificity between 23 and 73%. Subsequently, the cells with the three different integration sites were compared with the randomly integrated donor vector in terms of transcript level, productivity, gene copy numbers and stability. All site-specific integrations showed an increase in productivity and transcript levels of up to 7.4-fold. In a long-term cultivation over 70 generations, two of the site-specific integrations showed a stable productivity (>70%) independent of selection pressure.
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Affiliation(s)
- Oliver Hertel
- Cell Culture Technology, Faculty of Technology, Bielefeld University, Bielefeld, Germany
- Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
- *Correspondence: Oliver Hertel,
| | - Anne Neuss
- Biochemical Engineering (AVT.BioVT), RWTH Aachen University, Aachen, Germany
| | - Tobias Busche
- Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | - David Brandt
- Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | - Jörn Kalinowski
- Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | | | - Thomas Noll
- Cell Culture Technology, Faculty of Technology, Bielefeld University, Bielefeld, Germany
- Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
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13
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Schloßhauer JL, Cavak N, Zemella A, Thoring L, Kubick S. Cell Engineering and Cultivation of Chinese Hamster Ovary Cells for the Development of Orthogonal Eukaryotic Cell-free Translation Systems. Front Mol Biosci 2022; 9:832379. [PMID: 35586195 PMCID: PMC9109823 DOI: 10.3389/fmolb.2022.832379] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 03/15/2022] [Indexed: 12/03/2022] Open
Abstract
The investigation of protein structures, functions and interactions often requires modifications to adapt protein properties to the specific application. Among many possible methods to equip proteins with new chemical groups, the utilization of orthogonal aminoacyl-tRNA synthetase/tRNA pairs enables the site-specific incorporation of non-canonical amino acids at defined positions in the protein. The open nature of cell-free protein synthesis reactions provides an optimal environment, as the orthogonal components do not need to be transported across the cell membrane and the impact on cell viability is negligible. In the present work, it was shown that the expression of orthogonal aminoacyl-tRNA synthetases in CHO cells prior to cell disruption enhanced the modification of the pharmaceutically relevant adenosine A2a receptor. For this purpose, in complement to transient transfection of CHO cells, an approach based on CRISPR/Cas9 technology was selected to generate a translationally active cell lysate harboring endogenous orthogonal aminoacyl-tRNA synthetase.
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Affiliation(s)
- Jeffrey L. Schloßhauer
- Branch Bioanalytics and Bioprocesses (IZI-BB), Fraunhofer Institute for Cell Therapy and Immunology (IZI), Potsdam, Germany
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Niño Cavak
- Branch Bioanalytics and Bioprocesses (IZI-BB), Fraunhofer Institute for Cell Therapy and Immunology (IZI), Potsdam, Germany
| | - Anne Zemella
- Branch Bioanalytics and Bioprocesses (IZI-BB), Fraunhofer Institute for Cell Therapy and Immunology (IZI), Potsdam, Germany
| | - Lena Thoring
- Branch Bioanalytics and Bioprocesses (IZI-BB), Fraunhofer Institute for Cell Therapy and Immunology (IZI), Potsdam, Germany
| | - Stefan Kubick
- Branch Bioanalytics and Bioprocesses (IZI-BB), Fraunhofer Institute for Cell Therapy and Immunology (IZI), Potsdam, Germany
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
- Faculty of Health Sciences, Joint Faculty of the Brandenburg University of Technology Cottbus –Senftenberg, The Brandenburg Medical School Theodor Fontane and the University of Potsdam, Potsdam, Germany
- *Correspondence: Stefan Kubick,
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14
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Horie M, Yamano-Adachi N, Kawabe Y, Kaneoka H, Fujita H, Nagamori E, Iwai R, Sato Y, Kanie K, Ohta S, Somiya M, Ino K. Recent advances in animal cell technologies for industrial and medical applications. J Biosci Bioeng 2022; 133:509-514. [DOI: 10.1016/j.jbiosc.2022.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 03/07/2022] [Accepted: 03/07/2022] [Indexed: 11/25/2022]
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15
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Identification of Genomic Safe Harbors in the Anhydrobiotic Cell Line, Pv11. Genes (Basel) 2022; 13:genes13030406. [PMID: 35327960 PMCID: PMC8949610 DOI: 10.3390/genes13030406] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 02/17/2022] [Accepted: 02/21/2022] [Indexed: 12/22/2022] Open
Abstract
Genomic safe harbors (GSHs) provide ideal integration sites for generating transgenic organisms and cells and can be of great benefit in advancing the basic and applied biology of a particular species. Here we report the identification of GSHs in a dry-preservable insect cell line, Pv11, which derives from the sleeping chironomid, Polypedilum vanderplanki, and similar to the larvae of its progenitor species exhibits extreme desiccation tolerance. To identify GSHs, we carried out genome analysis of transgenic cell lines established by random integration of exogenous genes and found four candidate loci. Targeted knock-in was performed into these sites and the phenotypes of the resulting transgenic cell lines were examined. Precise integration was achieved for three candidate GSHs, and in all three cases integration did not alter the anhydrobiotic ability or the proliferation rate of the cell lines. We therefore suggest these genomic loci represent GSHs in Pv11 cells. Indeed, we successfully constructed a knock-in system and introduced an expression unit into one of these GSHs. We therefore identified several GSHs in Pv11 cells and developed a new technique for producing transgenic Pv11 cells without affecting the phenotype.
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16
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Stadermann A, Gamer M, Fieder J, Lindner B, Fehrmann S, Schmidt M, Schulz P, Gorr IH. Structural analysis of random transgene integration in CHO manufacturing cell lines by targeted sequencing. Biotechnol Bioeng 2021; 119:868-880. [PMID: 34935125 PMCID: PMC10138747 DOI: 10.1002/bit.28012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/29/2021] [Accepted: 11/30/2021] [Indexed: 11/08/2022]
Abstract
Genetically modified CHO cell lines are traditionally used for the production of biopharmaceuticals. However, an in-depth molecular understanding of the mechanism and exact position of transgene integration into the genome of pharmaceutical manufacturing cell lines is still scarce. Next Generation Sequencing (NGS) holds great promise for strongly facilitating the understanding of CHO cell factories, as it has matured to a powerful and affordable technology for cellular genotype analysis. Targeted Locus Amplification (TLA) combined with NGS allows for robust detection of genomic positions of transgene integration and structural genomic changes occurring upon stable integration of expression vectors. TLA was applied to generate comparative genomic fingerprints of several CHO production cell lines expressing different monoclonal antibodies. Moreover, high producers resulting from an additional round of transfection of an existing cell line (supertransfection) were analyzed to investigate the integrity and the number of integration sites. Our analyses enabled detailed genetic characterization of the integration regions with respect to the number of integrates and structural changes of the host cell's genome. Single integration sites per clone with concatenated transgene copies could be detected and were in some cases found to be associated with genomic rearrangements, deletions or translocations. Supertransfection resulted in an increase in titer associated with an additional integration site per clone. Based on the TLA fingerprints, CHO cell lines originating from the same mother clone could clearly be distinguished. Interestingly, two CHO cell lines originating from the same mother clone were shown to differ genetically and phenotypically despite of their identical TLA fingerprints. Taken together, TLA provides an accurate genetic characterization with respect to transgene integration sites compared to conventional methods and represents a valuable tool for a comprehensive evaluation of CHO production clones early in cell line development. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Anna Stadermann
- Bioprocess Development Biologicals, Cell Line Development, Boehringer Ingelheim GmbH & Co. KG, Birkendorfer Strasse 65, 88397, Biberach, Germany
| | - Martin Gamer
- R&D Project Management NBEs, Boehringer Ingelheim GmbH & Co. KG, Birkendorfer Strasse 65, 88397, Biberach, Germany
| | - Jürgen Fieder
- Bioprocess Development Biologicals, Cell Line Development, Boehringer Ingelheim GmbH & Co. KG, Birkendorfer Strasse 65, 88397, Biberach, Germany
| | - Benjamin Lindner
- Bioprocess Development Biologicals, Cell Line Development, Boehringer Ingelheim GmbH & Co. KG, Birkendorfer Strasse 65, 88397, Biberach, Germany
| | - Steffen Fehrmann
- Genedata AG, Selector BU, Margarethenstrasse 38, 4053, Basel, Switzerland
| | - Moritz Schmidt
- Bioprocess Development Biologicals, Cell Line Development, Boehringer Ingelheim GmbH & Co. KG, Birkendorfer Strasse 65, 88397, Biberach, Germany
| | - Patrick Schulz
- Bioprocess Development Biologicals, Cell Line Development, Boehringer Ingelheim GmbH & Co. KG, Birkendorfer Strasse 65, 88397, Biberach, Germany
| | - Ingo H Gorr
- Analytical Development Biologicals, Boehringer Ingelheim GmbH & Co. KG, Birkendorfer Strasse 65, 88397, Biberach, Germany
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17
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Tihanyi B, Nyitray L. Recent advances in CHO cell line development for recombinant protein production. DRUG DISCOVERY TODAY. TECHNOLOGIES 2021; 38:25-34. [PMID: 34895638 DOI: 10.1016/j.ddtec.2021.02.003] [Citation(s) in RCA: 81] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 02/02/2021] [Accepted: 02/23/2021] [Indexed: 12/20/2022]
Abstract
Recombinant proteins used in biomedical research, diagnostics and different therapies are mostly produced in Chinese hamster ovary cells in the pharmaceutical industry. These biotherapeutics, monoclonal antibodies in particular, have shown remarkable market growth in the past few decades. The increasing demand for high amounts of biologics requires continuous optimization and improvement of production technologies. Research aims at discovering better means and methods for reaching higher volumetric capacity, while maintaining stable product quality. An increasing number of complex novel protein therapeutics, such as viral antigens, vaccines, bi- and tri-specific monoclonal antibodies, are currently entering industrial production pipelines. These biomolecules are, in many cases, difficult to express and require tailored product-specific solutions to improve their transient or stable production. All these requirements boost the development of more efficient expression optimization systems and high-throughput screening platforms to facilitate the design of product-specific cell line engineering and production strategies. In this minireview, we provide an overview on recent advances in CHO cell line development, targeted genome manipulation techniques, selection systems and screening methods currently used in recombinant protein production.
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Affiliation(s)
- Borbála Tihanyi
- Department of Biochemistry, Eötvös Loránd University, Pázmány Péter stny 1/C, 1117 Budapest, Hungary
| | - László Nyitray
- Department of Biochemistry, Eötvös Loránd University, Pázmány Péter stny 1/C, 1117 Budapest, Hungary.
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18
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Arnesen JA, Hoof JB, Kildegaard HF, Borodina I. Genome Editing of Eukarya. Metab Eng 2021. [DOI: 10.1002/9783527823468.ch10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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19
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Pourtabatabaei S, Ghanbari S, Damavandi N, Bayat E, Raigani M, Zeinali S, Davami F. Targeted integration into pseudo attP sites of CHO cells using CRISPR/Cas9. J Biotechnol 2021; 337:1-7. [PMID: 34157351 DOI: 10.1016/j.jbiotec.2021.06.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 06/16/2021] [Indexed: 11/20/2022]
Abstract
Chinese hamster ovary (CHO) cells are regarded as a prominent host for manufacturing therapeutic proteins. Although conventional strategies for generating recombinant proteins in CHO cells depend on the random integration of a gene of interest (GOI), these established techniques occasionally result in genetically heterogeneous cell lines, which causes diminished expression of the recombinant proteins in the long run. Production instability can be reduced by SSI and creates stable cell lines with a consistent expression of the GOI. In this experiment, we demonstrate the targeted incorporation of a reporter cassette in two PhiC31 pseudo attP sites of CHO cells exploiting the homology-directed repair (HDR) generated by the CRISPR/Cas9 platform. Genes encoding GFP and puromycin resistance marker were precisely inserted into these loci via CRISPR/Cas9. Stable cell lines were suitably produced following antibiotic selection. Junction PCR and fluorescence assay determined targeted integration and expression homogeneity of the reporter cassette, respectively. Taken together, our results indicate the possibility of these two PhiC31 pseudo attP sites as the target sites for site-specific integration of a transgene mediated by CRISPR/Cas9. Furthermore, higher knock-in efficiency and expression homogeneity was observed in the pseudo attP site associated with chromosome 6 compared to the pseudo attP site from chromosome 3.
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Affiliation(s)
- Sana Pourtabatabaei
- Department of Biotechnology, College of Science, University of Tehran, Tehran, Iran; Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran; Kawsar Genomics and Biotech Center, Tehran, Iran
| | - Samaneh Ghanbari
- Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Narges Damavandi
- Department of Biotechnology, College of Science, University of Tehran, Tehran, Iran; Kawsar Genomics and Biotech Center, Tehran, Iran
| | - Elham Bayat
- Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Mozhgan Raigani
- Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Sirous Zeinali
- Department of Biotechnology, College of Science, University of Tehran, Tehran, Iran; Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran; Kawsar Genomics and Biotech Center, Tehran, Iran
| | - Fatemeh Davami
- Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran.
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20
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Safari F, Farajnia S, Behzad Behbahani A, Zarredar H, Barekati-Mowahed M, Dehghani H. Caspase-7 deficiency in Chinese hamster ovary cells reduces cell proliferation and viability. Biol Res 2020; 53:52. [PMID: 33187557 PMCID: PMC7666471 DOI: 10.1186/s40659-020-00319-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 11/04/2020] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Chinese hamster ovary (CHO) cells are the most commonly used mammalian host cell in the commercial-scale production of biopharmaceutical proteins. Modification of genes involved in apoptosis may improve the productivity of CHO cells. Executive caspases, including caspases 3 and 7, play critical roles in apoptosis. The effects of the ablation of the caspase 7 gene on proliferation and viability of CHO cells remains unknown. In this study, we applied clustered regularly interspaced short palindromic repeat (CRISPR/Cas9) to target caspase 7 gene of CHO K1 cell via all in one and homology targeted integration strategies. Consequently, the effect of caspase 7 deficiency on cell proliferation, viability, and apoptosis was studied by MTT assay and flow cytometry. RESULTS Findings of gel electrophoresis, western blotting, and sequencing confirmed the caspase 7 gene silencing in CHO cells (CHO-KO). Proliferation assay revealed that caspase 7 deficiency in CHO cells resulted in the reduction of proliferation in various CHO-KO clones. Besides, the disruption of caspase 7 had negative effects on cell viability in exposure with NaBu which confirmed by MTT assay. Results of flow cytometry using Anexin V/PI demonstrated that Nabu treatment (11 mM) declined the percentage of live CHO-K1 and CHO-KO cells to 70.3% and 5.79%. These results verified that the CHO-K1 cells were more resistant to apoptosis than CHO-KO, however most of CHO-KO cells undergone early apoptosis (91.9%) which seems to be a fascinating finding. CONCLUSION These results reveal that caspase 7 may be involved in the cell cycle progression of CHO cells. Furthermore, it seems that targeting caspase 7 is not the ideal route as it had previously been imagined within the prevention of apoptosis but the relation between caspase 7 deficiency, cell cycle arrest, and the occurrence of early apoptosis will require more investigation.
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Affiliation(s)
- Fatemeh Safari
- Department of Medical Biotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
- Diagnostic Laboratory Sciences and Technology Research Center, School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Safar Farajnia
- Biotechnology Research Center, Tabriz University of Medical Sciences, Daneshgah Ave., Tabriz, Iran.
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Abbas Behzad Behbahani
- Diagnostic Laboratory Sciences and Technology Research Center, School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Habib Zarredar
- Tuberculosis and Lung Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mazyar Barekati-Mowahed
- Department of Physiology & Biophysics, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Hesam Dehghani
- Department of Basic Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran
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21
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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]
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22
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Banan M. Recent advances in CRISPR/Cas9-mediated knock-ins in mammalian cells. J Biotechnol 2020; 308:1-9. [DOI: 10.1016/j.jbiotec.2019.11.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 11/16/2019] [Accepted: 11/17/2019] [Indexed: 12/16/2022]
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23
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Schweickert PG, Cheng Z. Application of Genetic Engineering in Biotherapeutics Development. J Pharm Innov 2019. [DOI: 10.1007/s12247-019-09411-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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24
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Carmignotto GP, Azzoni AR. On the expression of recombinant Cas9 protein in E. coli BL21(DE3) and BL21(DE3) Rosetta strains. J Biotechnol 2019; 306:62-70. [DOI: 10.1016/j.jbiotec.2019.09.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 09/18/2019] [Accepted: 09/19/2019] [Indexed: 02/08/2023]
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25
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Ahmadzadeh V, Farajnia S, Baghban R, Rahbarnia L, Zarredar H. CRISPR-Cas system: Toward a more efficient technology for genome editing and beyond. J Cell Biochem 2019; 120:16379-16392. [PMID: 31219653 DOI: 10.1002/jcb.29140] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 05/07/2019] [Indexed: 12/26/2022]
Abstract
Genome engineering technology is of great interest for biomedical research that enables scientists to make specific manipulation in the DNA sequence. Early methods for introducing double-stranded DNA breaks relies on protein-based systems. These platforms have enabled fascinating advances, but all are costly and time-consuming to engineer, preventing these from gaining high-throughput applications. The CRISPR-Cas9 system, co-opted from bacteria, has generated considerable excitement in gene targeting. In this review, we describe gene targeting techniques with an emphasis on recent strategies to improve the specificities of CRISPR-Cas systems for nuclease and non-nuclease applications.
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Affiliation(s)
- Vahideh Ahmadzadeh
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Safar Farajnia
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.,Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Roghayyeh Baghban
- Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Leila Rahbarnia
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Habib Zarredar
- Tuberculosis and Lung Disease Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
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26
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Mohammadian O, Rajabibazl M, Pourmaleki E, Bayat H, Ahani R, Rahimpour A. Development of an improved lentiviral based vector system for the stable expression of monoclonal antibody in CHO cells. Prep Biochem Biotechnol 2019; 49:822-829. [PMID: 31156045 DOI: 10.1080/10826068.2019.1621893] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Therapeutic monoclonal antibodies (mAbs) have become the dominant products in biopharmaceutical industry. Mammalian cell expression systems including Chinese hamster ovary (CHO) cells are the most commonly used hosts for the production of complex recombinant proteins. However, development of stable, high producing CHO cell lines suffers from the low expression level and instability of the transgene. The increasing efforts in the development of novel therapeutic antibodies and the advent of biosimilars have revealed the necessity for the development of improved platforms for rapid production of products for initial characterization and testing. In line with this premise, vector design and engineering has been applied to improve the expression level and stability of the transgene. This study reports the application of an improved lentiviral vector system containing the human interferon-β scaffold attachment region (IFN-SAR) for the development of antibody producing stable CHO cells. mAb expressing clones producing 1100 µg/L of IgG1 monoclonal antibody were isolated without extensive screening of a large number of clones. Our results here indicate the positive effects of IFN-SAR on stable mAb expression using lentiviral based expression vectors. We also observed that although IFN-SAR can improve light chain (LC) and heavy chain (HC) gene copy numbers in stable cell pools, mAb expression in single cell clones was not affected by the transgene copy number.
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Affiliation(s)
- Omid Mohammadian
- a Department of Clinical Biochemistry, School of Medicine, Shahid Beheshti University of Medical Sciences , Tehran , Iran
| | - Masoumeh Rajabibazl
- a Department of Clinical Biochemistry, School of Medicine, Shahid Beheshti University of Medical Sciences , Tehran , Iran.,b Nano-Technology and Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences , Tehran , Iran
| | - Es'hagh Pourmaleki
- b Nano-Technology and Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences , Tehran , Iran.,c Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences , Tehran , Iran
| | - Hadi Bayat
- b Nano-Technology and Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences , Tehran , Iran.,d Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University , Tehran , Iran
| | - Roshanak Ahani
- b Nano-Technology and Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences , Tehran , Iran
| | - Azam Rahimpour
- b Nano-Technology and Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences , Tehran , Iran.,c Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences , Tehran , Iran
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27
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Raab N, Mathias S, Alt K, Handrick R, Fischer S, Schmieder V, Jadhav V, Borth N, Otte K. CRISPR/Cas9-Mediated Knockout of MicroRNA-744 Improves Antibody Titer of CHO Production Cell Lines. Biotechnol J 2019; 14:e1800477. [PMID: 30802343 DOI: 10.1002/biot.201800477] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 01/25/2019] [Accepted: 01/28/2019] [Indexed: 12/18/2022]
Abstract
MicroRNAs (miRNAs) are noncoding RNAs that serve as versatile molecular engineering tools to improve production cells by overexpression or knockdown of miRNAs showing beneficial or adverse effects on cell-culture performance. The genomic knockout (KO) of noncoding RNAs in Chinese hamster ovary (CHO) production cells has not been reported. However, given the significant number of miRNAs showing negative effects on CHO-bioprocess performance and the development of clustered regularly interspaced short palindromic repeats/CRISPR-associated proteins (CRISPR/Cas9), genome editing tools facilitate precise optimization of CHO cells via modulation of noncoding RNAs. In a previous high-content miRNA screen, miR-744 was identified as a potential target associated with reduced productivity. Hence, the genomic miR-744 precursor sequence is deleted by two single guide RNA (sgRNA)-Cas9-mediated DNA double-strand breaks (DSB) flanking the miR-744 locus. After fluorescence-activated cell sorting (FACS), clonal miR-744 KO cell lines are recovered and three of them are confirmed as miR-744 KOs. Impacts of CRISPR/Cas9 editing are characterized at the genetic, transcript, and phenotypic levels. During batch cultivation, antibody titers of miR-744 KOs are significantly increased to 190-311 mg L-1 compared to a nontargeting (NT) sgRNA transfected clonal control with 156 mg L-1 , pointing towards the potential of miRNA KO for cell line engineering.
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Affiliation(s)
- Nadja Raab
- Institute of Applied Biotechnology, University of Applied Sciences Biberach, Hubertus-Liebrecht-Str. 35, Biberach, 88400, Germany
| | - Sven Mathias
- Institute of Applied Biotechnology, University of Applied Sciences Biberach, Hubertus-Liebrecht-Str. 35, Biberach, 88400, Germany
| | - Kerstin Alt
- Institute of Applied Biotechnology, University of Applied Sciences Biberach, Hubertus-Liebrecht-Str. 35, Biberach, 88400, Germany
- Genetikum, Wegenerstraße 15, Neu-Ulm, 89231, Germany
| | - René Handrick
- Institute of Applied Biotechnology, University of Applied Sciences Biberach, Hubertus-Liebrecht-Str. 35, Biberach, 88400, Germany
| | - Simon Fischer
- Boehringer Ingelheim Pharma GmbH & Co KG, Cell Line Development CMB, Birkendorfer Str. 65, Biberach, 88397, Germany
| | - Valerie Schmieder
- Austrian Center of Industrial Biotechnology, Muthgasse 11, Vienna, 1190, Austria
| | - Vaibhav Jadhav
- Austrian Center of Industrial Biotechnology, Muthgasse 11, Vienna, 1190, Austria
| | - Nicole Borth
- Austrian Center of Industrial Biotechnology, Muthgasse 11, Vienna, 1190, Austria
- BOKU Vienna, Institute of Biotechnology, Gregor-Mendel-Straße 33, Vienna, 1180, Austria
| | - Kerstin Otte
- Institute of Applied Biotechnology, University of Applied Sciences Biberach, Hubertus-Liebrecht-Str. 35, Biberach, 88400, Germany
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Smirnikhina SA, Anuchina AA, Lavrov AV. Ways of improving precise knock-in by genome-editing technologies. Hum Genet 2018; 138:1-19. [DOI: 10.1007/s00439-018-1953-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 10/29/2018] [Indexed: 02/07/2023]
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Hamaker NK, Lee KH. Site-specific Integration Ushers in a New Era of Precise CHO Cell Line Engineering. Curr Opin Chem Eng 2018; 22:152-160. [PMID: 31086757 DOI: 10.1016/j.coche.2018.09.011] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Chinese hamster ovary (CHO) cells are widely used for the production of therapeutic proteins. Customarily, CHO production cell lines are established through random integration, which requires laborious screening of many clones to isolate suitable producers. In contrast, site-specific integration (SSI) accelerates cell line development by targeting integration of transgenes to pre-validated genomic loci capable of supporting high and stable expression. To date, a relatively small number of these so called 'hot spots' have been identified, mainly through empirical methods. Nevertheless, nuclease-mediated and recombinase-mediated SSI have revolutionized cell line engineering by enabling rational and reproducible transgene targeting.
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Affiliation(s)
- Nathaniel K Hamaker
- Delaware Biotechnology Institute, Newark, DE.,Chemical and Biomolecular Engineering, University of Delaware, Newark, DE
| | - Kelvin H Lee
- Delaware Biotechnology Institute, Newark, DE.,Chemical and Biomolecular Engineering, University of Delaware, Newark, DE
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30
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Zhao M, Wang J, Luo M, Luo H, Zhao M, Han L, Zhang M, Yang H, Xie Y, Jiang H, Feng L, Lu H, Zhu J. Rapid development of stable transgene CHO cell lines by CRISPR/Cas9-mediated site-specific integration into C12orf35. Appl Microbiol Biotechnol 2018; 102:6105-6117. [PMID: 29789882 DOI: 10.1007/s00253-018-9021-6] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Revised: 04/12/2018] [Accepted: 04/13/2018] [Indexed: 12/16/2022]
Abstract
Chinese hamster ovary (CHO) cells are the most widely used mammalian hosts for recombinant protein production. However, by conventional random integration strategy, development of a high-expressing and stable recombinant CHO cell line has always been a difficult task due to the heterogenic insertion and its caused requirement of multiple rounds of selection. Site-specific integration of transgenes into CHO hot spots is an ideal strategy to overcome these challenges since it can generate isogenic cell lines with consistent productivity and stability. In this study, we investigated three sites with potential high transcriptional activities: C12orf35, HPRT, and GRIK1, to determine the possible transcriptional hot spots in CHO cells, and further construct a reliable site-specific integration strategy to develop recombinant cell lines efficiently. Genes encoding representative proteins mCherry and anti-PD1 monoclonal antibody were targeted into these three loci respectively through CRISPR/Cas9 technology. Stable cell lines were generated successfully after a single round of selection. In comparison with a random integration control, all the targeted integration cell lines showed higher productivity, among which C12orf35 locus was the most advantageous in both productivity and cell line stability. Binding affinity and N-glycan analysis of the antibody revealed that all batches of product were of similar quality independent on integrated sites. Deep sequencing demonstrated that there was low level of off-target mutations caused by CRISPR/Cas9, but none of them contributed to the development process of transgene cell lines. Our results demonstrated the feasibility of C12orf35 as the target site for exogenous gene integration, and strongly suggested that C12orf35 targeted integration mediated by CRISPR/Cas9 is a reliable strategy for the rapid development of recombinant CHO cell lines.
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Affiliation(s)
- Menglin Zhao
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Jiaxian Wang
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.,Department of Hematology, VU University Medical Center, Amsterdam, the Netherlands
| | - Manyu Luo
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Han Luo
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Meiqi Zhao
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Lei Han
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Mengxiao Zhang
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Hui Yang
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Yueqing Xie
- Jecho Laboratories, Inc., 7320 Executive Way, Frederick, MD, 21704, USA
| | - Hua Jiang
- Jecho Laboratories, Inc., 7320 Executive Way, Frederick, MD, 21704, USA
| | - Lei Feng
- Instrumental Analysis Center, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Huili Lu
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
| | - Jianwei Zhu
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China. .,Jecho Laboratories, Inc., 7320 Executive Way, Frederick, MD, 21704, USA.
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31
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Wang X, Kawabe Y, Hada T, Ito A, Kamihira M. Cre-Mediated Transgene Integration in Chinese Hamster Ovary Cells Using Minicircle DNA Vectors. Biotechnol J 2018; 13:e1800063. [DOI: 10.1002/biot.201800063] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Revised: 03/26/2018] [Indexed: 01/01/2023]
Affiliation(s)
- Xue Wang
- Department of Chemical Engineering, Faculty of Engineering, Kyushu University; 744 Motooka Nishi-ku, 819-0395 Japan
| | - Yoshinori Kawabe
- Department of Chemical Engineering, Faculty of Engineering, Kyushu University; 744 Motooka Nishi-ku, 819-0395 Japan
| | - Takeshi Hada
- Department of Chemical Engineering, Faculty of Engineering, Kyushu University; 744 Motooka Nishi-ku, 819-0395 Japan
| | - Akira Ito
- Department of Chemical Engineering, Faculty of Engineering, Kyushu University; 744 Motooka Nishi-ku, 819-0395 Japan
| | - Masamichi Kamihira
- Department of Chemical Engineering, Faculty of Engineering, Kyushu University; 744 Motooka Nishi-ku, 819-0395 Japan
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