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Blanch-Asensio A, Grandela C, Mummery CL, Davis RP. STRAIGHT-IN: a platform for rapidly generating panels of genetically modified human pluripotent stem cell lines. Nat Protoc 2024:10.1038/s41596-024-01039-2. [PMID: 39179886 DOI: 10.1038/s41596-024-01039-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 06/11/2024] [Indexed: 08/26/2024]
Abstract
Targeted integration of large DNA cargoes (>10 kb) or genomic replacements in mammalian cells, such as human pluripotent stem cells (hPS cells), remains challenging. Here we describe a platform termed serine and tyrosine recombinase-assisted integration of genes for high-throughput investigation (STRAIGHT-IN) to circumvent this. First, a landing pad cassette is precisely inserted or used to replace specific genomic regions. The site-specific integrase Bxb1 then enables DNA constructs, including those >50 kb, to be integrated into the genome, while Cre recombinase excises auxiliary DNA sequences to prevent postintegrative silencing. Using a strategy whereby the positive selection marker is only expressed if the donor plasmid carrying the payload is correctly targeted, we can obtain 100% enrichment for cells containing the DNA payload. Procedures for expressing Cre efficiently also mean that a clonal isolation step is no longer essential to derive the required genetically modified hPS cells containing the integrated DNA, potentially reducing clonal variability. Furthermore, STRAIGHT-IN facilitates rapid and multiplexed generation of genetically matched hPS cells when multiple donor plasmids are delivered simultaneously. STRAIGHT-IN has various applications, which include integrating complex genetic circuits for synthetic biology, as well as creating panels of hPS cells lines containing, as necessary, hundreds of disease-linked variants for disease modeling and drug discovery. After establishing the hPS cell line containing the landing pad, the entire procedure, including donor plasmid synthesis, takes 1.5-3 months, depending on whether single or multiple DNA payloads are integrated. This protocol only requires the researcher to be skilled in molecular biology and standard cell culture techniques.
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Affiliation(s)
- Albert Blanch-Asensio
- Department of Anatomy and Embryology, Leiden University Medical Center, Leiden, the Netherlands
- The Novo Nordisk Foundation Center for Stem Cell Medicine (reNEW), Leiden University Medical Center, Leiden, the Netherlands
| | - Catarina Grandela
- Department of Anatomy and Embryology, Leiden University Medical Center, Leiden, the Netherlands
| | - Christine L Mummery
- Department of Anatomy and Embryology, Leiden University Medical Center, Leiden, the Netherlands
- The Novo Nordisk Foundation Center for Stem Cell Medicine (reNEW), Leiden University Medical Center, Leiden, the Netherlands
| | - Richard P Davis
- Department of Anatomy and Embryology, Leiden University Medical Center, Leiden, the Netherlands.
- The Novo Nordisk Foundation Center for Stem Cell Medicine (reNEW), Leiden University Medical Center, Leiden, the Netherlands.
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2
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Lenser M, Ngo HG, Sarrafha L, Rajendra Y. Evaluation of two transposases for improving expression of recombinant proteins in Chinese hamster ovary cell stable pools by co-transfection and supertransfection approaches. Biotechnol Prog 2024:e3496. [PMID: 39016635 DOI: 10.1002/btpr.3496] [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: 03/26/2024] [Revised: 06/13/2024] [Accepted: 07/09/2024] [Indexed: 07/18/2024]
Abstract
Transposons are genetic elements capable of cutting and pasting genes of interest via the action of a transposase and offer many advantages over random or targeted integration of DNA in the creation of Chinese hamster ovary (CHO) cell lines for recombinant protein expression. Unique transposases have different recognition sites, allowing multiple transposases to be co-transfected together. They also allow for supertransfection (transfection on a previously transfected pool or cell line) with a second transposase to integrate additional copies of the same gene or an additional gene without disruption of the previously integrated DNA which to our knowledge has not been previously described in literature. Two fluorescent proteins, EGFP and tagRFP657, were either co-transfected or supertransfected into CHO cells using two unique transposases and showed high expression efficiency with similar expression levels (measured as mean fluorescence intensity), regardless of whether the genes were co-transfected or supertransfected onto an existing stable pool. Additionally, dual selection of the genes, both in the absence of L-glutamine and the presence of puromycin, led to higher expression levels than single selection alone. These results demonstrate that supertransfection using unique transposases could be a useful strategy for increasing titers of existing cell lines or for overexpressing helper (non-therapeutic) genes to improve expression and/or product quality of existing pools and cell lines, potentially saving significant time and resources.
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Affiliation(s)
- Melina Lenser
- Bioprocess Development, Technical Operations, Denali Therapeutics, Inc., South San Francisco, California, USA
| | - Hanh Giai Ngo
- Bioprocess Development, Technical Operations, Denali Therapeutics, Inc., South San Francisco, California, USA
| | - Lily Sarrafha
- Discovery Biology, Denali Therapeutics, Inc., South San Francisco, California, USA
| | - Yashas Rajendra
- Bioprocess Development, Technical Operations, Denali Therapeutics, Inc., South San Francisco, California, USA
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3
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Wang Z, Kang M, Ebrahimpour A, Chen C, Ge X. Fc engineering by monoclonal mammalian cell display for improved affinity and selectivity towards FcγRs. Antib Ther 2024; 7:209-220. [PMID: 39036072 PMCID: PMC11259757 DOI: 10.1093/abt/tbae017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 05/29/2024] [Accepted: 06/20/2024] [Indexed: 07/23/2024] Open
Abstract
Fc optimization can significantly enhance therapeutic efficacy of monoclonal antibodies. However, existing Fc engineering approaches are sub-optimal with noted limitations, such as inappropriate glycosylation, polyclonal libraries, and utilizing fragment but not full-length IgG display. Applying cell cycle arrested recombinase-mediated cassette exchange, this study constructed high-quality monoclonal Fc libraries in CHO cells, displayed full-length IgG on cell surface, and preformed ratiometric fluorescence activated cell sorting (FACS) with the antigen and individual FcγRs. Identified Fc variants were quantitatively evaluated by flow cytometry, ELISA, kinetic and steady-state binding affinity measurements, and cytotoxicity assays. An error-prone Fc library focusing on the hinge-CH2 region was constructed in CHO cells with a functional diversity of 7.5 × 106. Panels of novel Fc variants with enhanced affinity and selectivity for FcγRs were isolated. Particularly, clone 2a-10 (G236E/K288R/K290W/K320M) showed increased binding strength towards FcγRIIa-131R and 131H allotypes with kinetic dissociation constants (KD-K) of 140 nM and 220 nM, respectively, while reduced binding strength towards FcγRIIb compared to WT Fc; clone 2b-1 (K222I/V302E/L328F/K334E) had KD-K of 180 nM towards FcγRIIb; clone 3a-2 (P247L/K248E/K334I) exhibited KD-K of 190 nM and 100 nM towards FcγRIIIa-176F and 176 V allotypes, respectively, and improved potency of 2.0 ng/ml in ADCC assays. Key mutation hotspots were identified, including P247 for FcγRIIIa, K290 for FcγRIIa, and K334 for FcγRIIb bindings. Discovery of Fc variants with enhanced affinity and selectivity towards individual FcγR and the identification of novel mutation hotspots provide valuable insights for further Fc optimization and serve as a foundation for advancing antibody therapeutics development.
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Affiliation(s)
- Zening Wang
- Institute of Molecular Medicine, University of Texas Health Science Center at Houston, 1825 Pressler St, Houston, TX 77030, United States
- Department of Chemical and Environmental Engineering, University of California Riverside, 900 University Ave, Reverside, CA 92521, United States
| | - Minhyo Kang
- Department of Chemical and Environmental Engineering, University of California Riverside, 900 University Ave, Reverside, CA 92521, United States
| | - Afshin Ebrahimpour
- Institute of Molecular Medicine, University of Texas Health Science Center at Houston, 1825 Pressler St, Houston, TX 77030, United States
| | - Chuan Chen
- Department of Chemical and Environmental Engineering, University of California Riverside, 900 University Ave, Reverside, CA 92521, United States
| | - Xin Ge
- Institute of Molecular Medicine, University of Texas Health Science Center at Houston, 1825 Pressler St, Houston, TX 77030, United States
- Department of Chemical and Environmental Engineering, University of California Riverside, 900 University Ave, Reverside, CA 92521, United States
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4
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Huhtinen O, Prince S, Lamminmäki U, Salbo R, Kulmala A. Increased stable integration efficiency in CHO cells through enhanced nuclear localization of Bxb1 serine integrase. BMC Biotechnol 2024; 24:44. [PMID: 38926833 PMCID: PMC11210126 DOI: 10.1186/s12896-024-00871-4] [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: 02/02/2024] [Accepted: 06/20/2024] [Indexed: 06/28/2024] Open
Abstract
BACKGROUND Mammalian display is an appealing technology for therapeutic antibody development. Despite the advantages of mammalian display, such as full-length IgG display with mammalian glycosylation and its inherent ability to select antibodies with good biophysical properties, the restricted library size and large culture volumes remain challenges. Bxb1 serine integrase is commonly used for the stable genomic integration of antibody genes into mammalian cells, but presently lacks the efficiency required for the display of large mammalian display libraries. To increase the Bxb1 integrase-mediated stable integration efficiency, our study investigates factors that potentially affect the nuclear localization of Bxb1 integrase. METHODS In an attempt to enhance Bxb1 serine integrase-mediated integration efficiency, we fused various nuclear localization signals (NLS) to the N- and C-termini of the integrase. Concurrently, we co-expressed multiple proteins associated with nuclear transport to assess their impact on the stable integration efficiency of green fluorescent protein (GFP)-encoding DNA and an antibody display cassette into the genome of Chinese hamster ovary (CHO) cells containing a landing pad for Bxb1 integrase-mediated integration. RESULTS The nucleoplasmin NLS from Xenopus laevis, when fused to the C-terminus of Bxb1 integrase, demonstrated the highest enhancement in stable integration efficiency among the tested NLS fusions, exhibiting over a 6-fold improvement compared to Bxb1 integrase lacking an NLS fusion. Subsequent additions of extra NLS fusions to the Bxb1 integrase revealed an additional 131% enhancement in stable integration efficiency with the inclusion of two copies of C-terminal nucleoplasmin NLS fusions. Further improvement was achieved by co-expressing the Ran GTPase-activating protein (RanGAP). Finally, to validate the applicability of these findings to more complex proteins, the DNA encoding the membrane-bound clinical antibody abrilumab was stably integrated into the genome of CHO cells using Bxb1 integrase with two copies of C-terminal nucleoplasmin NLS fusions and co-expression of RanGAP. This approach demonstrated over 14-fold increase in integration efficiency compared to Bxb1 integrase lacking an NLS fusion. CONCLUSIONS This study demonstrates that optimizing the NLS sequence fusion for Bxb1 integrase significantly enhances the stable genomic integration efficiency. These findings provide a practical approach for constructing larger libraries in mammalian cells through the stable integration of genes into a genomic landing pad.
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Affiliation(s)
- Olli Huhtinen
- Protein & Antibody Engineering, Orion Corporation, Turku, Finland.
- Department of Life Technologies, University of Turku, Turku, Finland.
| | - Stuart Prince
- MediCity Research Laboratory, University of Turku, Turku, Finland
- Institute of Biomedicine, University of Turku, Turku, Finland
| | - Urpo Lamminmäki
- Department of Life Technologies, University of Turku, Turku, Finland
| | - Rune Salbo
- Protein & Antibody Engineering, Orion Corporation, Turku, Finland
| | - Antti Kulmala
- Protein & Antibody Engineering, Orion Corporation, Turku, Finland.
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de Oliveira MA, Florentino LH, Sales TT, Lima RN, Barros LRC, Limia CG, Almeida MSM, Robledo ML, Barros LMG, Melo EO, Bittencourt DM, Rehen SK, Bonamino MH, Rech E. Protocol for the establishment of a serine integrase-based platform for functional validation of genetic switch controllers in eukaryotic cells. PLoS One 2024; 19:e0303999. [PMID: 38781126 PMCID: PMC11115199 DOI: 10.1371/journal.pone.0303999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 05/04/2024] [Indexed: 05/25/2024] Open
Abstract
Serine integrases (Ints) are a family of site-specific recombinases (SSRs) encoded by some bacteriophages to integrate their genetic material into the genome of a host. Their ability to rearrange DNA sequences in different ways including inversion, excision, or insertion with no help from endogenous molecular machinery, confers important biotechnological value as genetic editing tools with high host plasticity. Despite advances in their use in prokaryotic cells, only a few Ints are currently used as gene editors in eukaryotes, partly due to the functional loss and cytotoxicity presented by some candidates in more complex organisms. To help expand the number of Ints available for the assembly of more complex multifunctional circuits in eukaryotic cells, this protocol describes a platform for the assembly and functional screening of serine-integrase-based genetic switches designed to control gene expression by directional inversions of DNA sequence orientation. The system consists of two sets of plasmids, an effector module and a reporter module, both sets assembled with regulatory components (as promoter and terminator regions) appropriate for expression in mammals, including humans, and plants. The complete method involves plasmid design, DNA delivery, testing and both molecular and phenotypical assessment of results. This platform presents a suitable workflow for the identification and functional validation of new tools for the genetic regulation and reprogramming of organisms with importance in different fields, from medical applications to crop enhancement, as shown by the initial results obtained. This protocol can be completed in 4 weeks for mammalian cells or up to 8 weeks for plant cells, considering cell culture or plant growth time.
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Affiliation(s)
- Marco A. de Oliveira
- Department of Cell Biology, Institute of Biological Science, University of Brasília, Brasília, Distrito Federal, Brazil
- National Institute of Science and Technology in Synthetic Biology (INCT BioSyn), Brasília, Distrito Federal, Brazil
| | - Lilian H. Florentino
- Department of Cell Biology, Institute of Biological Science, University of Brasília, Brasília, Distrito Federal, Brazil
- National Institute of Science and Technology in Synthetic Biology (INCT BioSyn), Brasília, Distrito Federal, Brazil
- Embrapa Genetic Resources and Biotechnology, Brasília, Distrito Federal, Brazil
| | - Thais T. Sales
- Department of Cell Biology, Institute of Biological Science, University of Brasília, Brasília, Distrito Federal, Brazil
- National Institute of Science and Technology in Synthetic Biology (INCT BioSyn), Brasília, Distrito Federal, Brazil
- Embrapa Genetic Resources and Biotechnology, Brasília, Distrito Federal, Brazil
| | - Rayane N. Lima
- National Institute of Science and Technology in Synthetic Biology (INCT BioSyn), Brasília, Distrito Federal, Brazil
- Embrapa Genetic Resources and Biotechnology, Brasília, Distrito Federal, Brazil
| | - Luciana R. C. Barros
- Center for Translational Research in Oncology, Instituto do Câncer do Estado de São Paulo, Hospital das Clínicas da Faculdade de Medicina de Universidade de São Paulo, São Paulo, Brazil
| | - Cintia G. Limia
- Molecular Carcinogenesis Program, Research Coordination, National Cancer Institute (INCA), Rio de Janeiro, Brazil
| | - Mariana S. M. Almeida
- National Institute of Science and Technology in Synthetic Biology (INCT BioSyn), Brasília, Distrito Federal, Brazil
- Embrapa Genetic Resources and Biotechnology, Brasília, Distrito Federal, Brazil
| | - Maria L. Robledo
- Molecular Carcinogenesis Program, Research Coordination, National Cancer Institute (INCA), Rio de Janeiro, Brazil
| | - Leila M. G. Barros
- National Institute of Science and Technology in Synthetic Biology (INCT BioSyn), Brasília, Distrito Federal, Brazil
- Embrapa Genetic Resources and Biotechnology, Brasília, Distrito Federal, Brazil
| | - Eduardo O. Melo
- National Institute of Science and Technology in Synthetic Biology (INCT BioSyn), Brasília, Distrito Federal, Brazil
- Embrapa Genetic Resources and Biotechnology, Brasília, Distrito Federal, Brazil
| | - Daniela M. Bittencourt
- National Institute of Science and Technology in Synthetic Biology (INCT BioSyn), Brasília, Distrito Federal, Brazil
- Embrapa Genetic Resources and Biotechnology, Brasília, Distrito Federal, Brazil
| | - Stevens K. Rehen
- D’Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Martín H. Bonamino
- Cell and Gene Therapy Program, Research Coordination, National Cancer Institute (INCA), Rio de Janeiro, Brazil
- Vice-Presidency of Research and Biological Collections (VPPCB), FIOCRUZ – Oswaldo Cruz Foundation Institute, Rio de Janeiro, Brazil
| | - Elibio Rech
- National Institute of Science and Technology in Synthetic Biology (INCT BioSyn), Brasília, Distrito Federal, Brazil
- Embrapa Genetic Resources and Biotechnology, Brasília, Distrito Federal, Brazil
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6
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Laurent M, Geoffroy M, Pavani G, Guiraud S. CRISPR-Based Gene Therapies: From Preclinical to Clinical Treatments. Cells 2024; 13:800. [PMID: 38786024 PMCID: PMC11119143 DOI: 10.3390/cells13100800] [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: 03/26/2024] [Revised: 05/03/2024] [Accepted: 05/05/2024] [Indexed: 05/25/2024] Open
Abstract
In recent years, clustered regularly interspaced short palindromic repeats (CRISPRs) and CRISPR-associated (Cas) protein have emerged as a revolutionary gene editing tool to treat inherited disorders affecting different organ systems, such as blood and muscles. Both hematological and neuromuscular genetic disorders benefit from genome editing approaches but face different challenges in their clinical translation. The ability of CRISPR/Cas9 technologies to modify hematopoietic stem cells ex vivo has greatly accelerated the development of genetic therapies for blood disorders. In the last decade, many clinical trials were initiated and are now delivering encouraging results. The recent FDA approval of Casgevy, the first CRISPR/Cas9-based drug for severe sickle cell disease and transfusion-dependent β-thalassemia, represents a significant milestone in the field and highlights the great potential of this technology. Similar preclinical efforts are currently expanding CRISPR therapies to other hematologic disorders such as primary immunodeficiencies. In the neuromuscular field, the versatility of CRISPR/Cas9 has been instrumental for the generation of new cellular and animal models of Duchenne muscular dystrophy (DMD), offering innovative platforms to speed up preclinical development of therapeutic solutions. Several corrective interventions have been proposed to genetically restore dystrophin production using the CRISPR toolbox and have demonstrated promising results in different DMD animal models. Although these advances represent a significant step forward to the clinical translation of CRISPR/Cas9 therapies to DMD, there are still many hurdles to overcome, such as in vivo delivery methods associated with high viral vector doses, together with safety and immunological concerns. Collectively, the results obtained in the hematological and neuromuscular fields emphasize the transformative impact of CRISPR/Cas9 for patients affected by these debilitating conditions. As each field suffers from different and specific challenges, the clinical translation of CRISPR therapies may progress differentially depending on the genetic disorder. Ongoing investigations and clinical trials will address risks and limitations of these therapies, including long-term efficacy, potential genotoxicity, and adverse immune reactions. This review provides insights into the diverse applications of CRISPR-based technologies in both preclinical and clinical settings for monogenic blood disorders and muscular dystrophy and compare advances in both fields while highlighting current trends, difficulties, and challenges to overcome.
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Affiliation(s)
- Marine Laurent
- INTEGRARE, UMR_S951, Genethon, Inserm, Univ Evry, Université Paris-Saclay, 91190 Evry, France
| | | | - Giulia Pavani
- Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Simon Guiraud
- SQY Therapeutics, 78180 Montigny-le-Bretonneux, France
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7
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Wang Z, Chen C, Ge X. Large T antigen mediated target gene replication improves site-specific recombination efficiency. Front Bioeng Biotechnol 2024; 12:1377167. [PMID: 38737535 PMCID: PMC11082406 DOI: 10.3389/fbioe.2024.1377167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Accepted: 04/11/2024] [Indexed: 05/14/2024] Open
Abstract
With advantages of high-fidelity, monoclonality and large cargo capacity, site-specific recombination (SSR) holds great promises for precise genomic modifications. However, broad applications of SSR have been hurdled by low integration efficiency, and the amount of donor DNA available in nucleus for SSR presents as a limiting factor. Inspired by the DNA replication mechanisms observed in double-stranded DNA virus SV40, we hypothesized that expression of SV40 large T antigen (TAg) can increase the copy number of the donor plasmid bearing an SV40 origin, and in consequence promote recombination events. This hypothesis was tested with dual recombinase-mediated cassette exchange (RMCE) in suspension 293F cells. Results showed that TAg co-transfection significantly enhanced SSR in polyclonal cells. In the monoclonal cell line carrying a single landing pad at an identified genomic locus, 12% RMCE efficiency was achieved, and such improvement was indeed correlated with donor plasmid amplification. The developed TAg facilitated RMCE (T-RMCE) was exploited for the construction of large libraries of >107 diversity, from which GFP variants with enhanced fluorescence were isolated. We expect the underlying principle of target gene amplification can be applicable to other SSR processes and gene editing approaches in general for directed evolution and large-scale genomic screening in mammalian cells.
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Affiliation(s)
- Zening Wang
- Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX, United States
- Department of Chemical and Environmental Engineering, University of California Riverside, Riverside, CA, United States
| | - Chuan Chen
- Department of Chemical and Environmental Engineering, University of California Riverside, Riverside, CA, United States
| | - Xin Ge
- Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX, United States
- Department of Chemical and Environmental Engineering, University of California Riverside, Riverside, CA, United States
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8
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Xu Y, Crowe KB, Lieske PL, Barnes M, Bandara K, Chu J, Wei W, Scarcelli JJ, Zhang L. A high-fidelity, dual site-specific integration system in CHO cells by a Bxb1 recombinase. Biotechnol J 2024; 19:e2300410. [PMID: 38375559 DOI: 10.1002/biot.202300410] [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: 08/14/2023] [Revised: 11/16/2023] [Accepted: 12/06/2023] [Indexed: 02/21/2024]
Abstract
Site-specific integration (SSI) via recombinase mediated cassette exchange (RMCE) has shown advantages over random integration methods for expression of biotherapeutics. As an extension of our previous work developing SSI host cells, we developed a dual-site SSI system having two independent integration sites at different genomic loci, each containing a unique landing pad (LP). This system was leveraged to generate and compare two RMCE hosts, one (dFRT) compatible with the Flp recombinase, the other (dBxb1) compatible with the Bxb1 recombinase. Our comparison demonstrated that the dBxb1 host was able to generate stable transfectant pools in a shorter time frame, and cells within the dBxb1 transfectant pools were more phenotypically and genotypically stable. We further improved process performance of the dBxb1 host, resulting in desired fed batch performance attributes. Clones derived from this improved host (referred as 41L-11) maintained stable expression profiles over extended generations. While the data represents a significant improvement in the efficiency of our cell line development process, the dual LP architecture also affords a high degree of flexibility for development of complex protein modalities.
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Affiliation(s)
- Yifeng Xu
- Cell Line Development, Bioprocess R&D, Biotherapeutics Pharmaceutical Science, Pfizer Inc, Andover, Massachusetts, USA
| | - Kerstin B Crowe
- Cell Line Development, Bioprocess R&D, Biotherapeutics Pharmaceutical Science, Pfizer Inc, Andover, Massachusetts, USA
| | - Paulena L Lieske
- Cell Line Development, Bioprocess R&D, Biotherapeutics Pharmaceutical Science, Pfizer Inc, Andover, Massachusetts, USA
| | - Michael Barnes
- Cell Line Development, Bioprocess R&D, Biotherapeutics Pharmaceutical Science, Pfizer Inc, Andover, Massachusetts, USA
| | - Kalpanie Bandara
- Cell Line Development, Bioprocess R&D, Biotherapeutics Pharmaceutical Science, Pfizer Inc, Andover, Massachusetts, USA
| | - Jianlin Chu
- Cell Line Development, Bioprocess R&D, Biotherapeutics Pharmaceutical Science, Pfizer Inc, Andover, Massachusetts, USA
| | - Wei Wei
- Cell Line Development, Bioprocess R&D, Biotherapeutics Pharmaceutical Science, Pfizer Inc, Andover, Massachusetts, USA
| | - John J Scarcelli
- Cell Line Development, Bioprocess R&D, Biotherapeutics Pharmaceutical Science, Pfizer Inc, Andover, Massachusetts, USA
| | - Lin Zhang
- Cell Line Development, Bioprocess R&D, Biotherapeutics Pharmaceutical Science, Pfizer Inc, Andover, Massachusetts, USA
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9
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Zhang C, Chang F, Miao H, Fu Y, Tong X, Feng Y, Zheng W, Ma X. Construction and application of a multifunctional CHO cell platform utilizing Cre/ lox and Dre/ rox site-specific recombination systems. Front Bioeng Biotechnol 2023; 11:1320841. [PMID: 38173869 PMCID: PMC10761530 DOI: 10.3389/fbioe.2023.1320841] [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: 10/13/2023] [Accepted: 12/04/2023] [Indexed: 01/05/2024] Open
Abstract
During the development of traditional Chinese hamster ovary (CHO) cell lines, target genes randomly integrate into the genome upon entering the nucleus, resulting in unpredictable productivity of cell clones. The characterization and screening of high-yielding cell lines is a time-consuming and expensive process. Site-specific integration is recognized as an effective approach for overcoming random integration and improving production stability. We have designed a multifunctional expression cassette, called CDbox, which can be manipulated by the site-specific recombination systems Cre/lox and Dre/rox. The CDbox expression cassette was inserted at the Hipp11(H11) locus hotspot in the CHO-K1 genome using CRISPR/Cas9 technology, and a compliant CHO-CDbox cell platform was screened and obtained. The CHO-CDbox cell platform was transformed into a pool of EGFP-expressing cells using Cre/lox recombinase-mediated cassette exchange (RMCE) in only 2 weeks, and this expression remained stable for at least 75 generations without the need for drug stress. Subsequently, we used the Dre/rox system to directly eliminate the EGFP gene. In addition, two practical applications of the CHO-CDbox cell platform were presented. The first was the quick construction of the Pembrolizumab antibody stable expression strain, while the second was a protocol for the integration of surface-displayed and secreted antibodies on CHO cells. The previous research on site-specific integration of CHO cells has always focused on the single functionality of insertion of target genes. This newly developed CHO cell platform is expected to offer expanded applicability for protein production and gene function studies.
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Affiliation(s)
- Chen Zhang
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Feng Chang
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Hui Miao
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Yunhui Fu
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Xikui Tong
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Yu Feng
- Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Wenyun Zheng
- Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Xingyuan Ma
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, China
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10
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Chen C, Wang Z, Kang M, Lee KB, Ge X. High-fidelity large-diversity monoclonal mammalian cell libraries by cell cycle arrested recombinase-mediated cassette exchange. Nucleic Acids Res 2023; 51:e113. [PMID: 37941133 PMCID: PMC10711435 DOI: 10.1093/nar/gkad1001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 09/26/2023] [Accepted: 10/18/2023] [Indexed: 11/10/2023] Open
Abstract
Mammalian cells carrying defined genetic variations have shown great potentials in both fundamental research and therapeutic development. However, their full use was limited by lack of a robust method to construct large monoclonal high-quality combinatorial libraries. This study developed cell cycle arrested recombinase-mediated cassette exchange (aRMCE), able to provide monoclonality, precise genomic integration and uniform transgene expression. Via optimized nocodazole-mediated mitotic arrest, 20% target gene replacement efficiency was achieved without antibiotic selection, and the improved aRMCE efficiency was applicable to a variety of tested cell clones, transgene targets and transfection methods. As a demonstration of this versatile method, we performed directed evolution of fragment crystallizable (Fc), for which error-prone libraries of over 107 variants were constructed and displayed as IgG on surface of CHO cells. Diversities of constructed libraries were validated by deep sequencing, and panels of novel Fc mutants were identified showing improved binding towards specific Fc gamma receptors and enhanced effector functions. Due to its large cargo capacity and compatibility with different mutagenesis approaches, we expect this mammalian cell platform technology has broad applications for directed evolution, multiplex genetic assays, cell line development and stem cell engineering.
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Affiliation(s)
- Chuan Chen
- Department of Chemical and Environmental Engineering, University of California Riverside, Riverside, CA 92521, USA
| | - Zening Wang
- Department of Chemical and Environmental Engineering, University of California Riverside, Riverside, CA 92521, USA
- Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Minhyo Kang
- Department of Chemical and Environmental Engineering, University of California Riverside, Riverside, CA 92521, USA
| | - Ki Baek Lee
- Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Xin Ge
- Department of Chemical and Environmental Engineering, University of California Riverside, Riverside, CA 92521, USA
- Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
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11
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Gaa R, Kumari K, Mayer HM, Yanakieva D, Tsai SP, Joshi S, Guenther R, Doerner A. An integrated mammalian library approach for optimization and enhanced microfluidics-assisted antibody hit discovery. ARTIFICIAL CELLS, NANOMEDICINE, AND BIOTECHNOLOGY 2023; 51:74-82. [PMID: 36762883 DOI: 10.1080/21691401.2023.2173219] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Recent years have seen the development of a variety of mammalian library approaches for display and secretion mode. Advantages include library approaches for engineering, preservation of precious immune repertoires and their repeated interrogation, as well as screening in final therapeutic format and host. Mammalian display approaches for antibody optimization exploit these advantages, necessitating the generation of large libraries but in turn enabling early screening for both manufacturability and target specificity. For suitable libraries, high antibody integration rates and resulting monoclonality need to be balanced - we present a solution for sufficient transmutability and acceptable monoclonality by applying an optimized ratio of coding to non-coding lentivirus. The recent advent of microfluidic-assisted hit discovery represents a perfect match to mammalian libraries in secretion mode, as the lower throughput fits well with the facile generation of libraries comprising a few million functional clones. In the presented work, Chinese Hamster Ovary cells were engineered to both express the target of interest and secrete antibodies in relevant formats, and specific clones were strongly enriched by high throughput screening for autocrine cellular binding. The powerful combination of mammalian secretion libraries and microfluidics-assisted hit discovery could reduce attrition rates and increase the probability to identify the best possible therapeutic antibody hits faster.
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Affiliation(s)
- Ramona Gaa
- Protein Engineering and Antibody Technologies, Merck KGaA, Darmstadt, Germany
| | - Kavita Kumari
- Discovery Biology, Syngene International, Phase-IV, Bangalore, India
| | - Hannah Melina Mayer
- Protein Engineering and Antibody Technologies, Merck KGaA, Darmstadt, Germany
| | - Desislava Yanakieva
- Protein Engineering and Antibody Technologies, Merck KGaA, Darmstadt, Germany
| | - Shang-Pu Tsai
- Protein Engineering and Antibody Technologies, EMD Serono, Billerica, MA, USA
| | - Saurabh Joshi
- Discovery Biology, Syngene International, Phase-IV, Bangalore, India
| | - Ralf Guenther
- Protein Engineering and Antibody Technologies, Merck KGaA, Darmstadt, Germany
| | - Achim Doerner
- Protein Engineering and Antibody Technologies, Merck KGaA, Darmstadt, Germany
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12
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Maes S, Deploey N, Peelman F, Eyckerman S. Deep mutational scanning of proteins in mammalian cells. CELL REPORTS METHODS 2023; 3:100641. [PMID: 37963462 PMCID: PMC10694495 DOI: 10.1016/j.crmeth.2023.100641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 07/06/2023] [Accepted: 10/20/2023] [Indexed: 11/16/2023]
Abstract
Protein mutagenesis is essential for unveiling the molecular mechanisms underlying protein function in health, disease, and evolution. In the past decade, deep mutational scanning methods have evolved to support the functional analysis of nearly all possible single-amino acid changes in a protein of interest. While historically these methods were developed in lower organisms such as E. coli and yeast, recent technological advancements have resulted in the increased use of mammalian cells, particularly for studying proteins involved in human disease. These advancements will aid significantly in the classification and interpretation of variants of unknown significance, which are being discovered at large scale due to the current surge in the use of whole-genome sequencing in clinical contexts. Here, we explore the experimental aspects of deep mutational scanning studies in mammalian cells and report the different methods used in each step of the workflow, ultimately providing a useful guide toward the design of such studies.
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Affiliation(s)
- Stefanie Maes
- VIB Center for Medical Biotechnology (CMB), Technologiepark-Zwijnaarde 75, 9052 Ghent, Belgium; Department of Biochemistry and Microbiology, Ghent University, Technologiepark-Zwijnaarde 75, 9052 Ghent, Belgium; Department of Biomolecular Medicine, Ghent University, Technologiepark-Zwijnaarde 75, 9052 Ghent, Belgium
| | - Nick Deploey
- VIB Center for Medical Biotechnology (CMB), Technologiepark-Zwijnaarde 75, 9052 Ghent, Belgium; Department of Biomolecular Medicine, Ghent University, Technologiepark-Zwijnaarde 75, 9052 Ghent, Belgium
| | - Frank Peelman
- VIB Center for Medical Biotechnology (CMB), Technologiepark-Zwijnaarde 75, 9052 Ghent, Belgium; Department of Biomolecular Medicine, Ghent University, Technologiepark-Zwijnaarde 75, 9052 Ghent, Belgium
| | - Sven Eyckerman
- VIB Center for Medical Biotechnology (CMB), Technologiepark-Zwijnaarde 75, 9052 Ghent, Belgium; Department of Biomolecular Medicine, Ghent University, Technologiepark-Zwijnaarde 75, 9052 Ghent, Belgium.
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13
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Roelle S, Kamath ND, Matreyek KA. Mammalian Genomic Manipulation with Orthogonal Bxb1 DNA Recombinase Sites for the Functional Characterization of Protein Variants. ACS Synth Biol 2023; 12:3352-3365. [PMID: 37922210 PMCID: PMC10661055 DOI: 10.1021/acssynbio.3c00355] [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: 06/10/2023] [Revised: 09/22/2023] [Accepted: 10/19/2023] [Indexed: 11/05/2023]
Abstract
The Bxb1 bacteriophage serine DNA recombinase is an efficient tool for engineering recombinant DNA into the genomes of cultured cells. Generally, a single engineered "landing pad" site is introduced into the cell genome, permitting the integration of transgenic circuits or libraries of transgene variants. While sufficient for many studies, the extent of genetic manipulation possible with a single recombinase site is limiting and insufficient for more complex cell-based assays. Here, we harnessed two orthogonal Bxb1 recombinase sites to enable alternative avenues for using mammalian synthetic biology to characterize transgenic protein variants. By designing plasmids flanked by a second pair of auxiliary recombination sites, we demonstrate that we can avoid the genomic integration of undesirable bacterial DNA elements using the same starting cells engineered for whole-plasmid integration. We also created "double landing pad" cells simultaneously harboring two orthogonal Bxb1 recombinase sites at separate genomic loci, allowing complex cell-based genetic assays. Integration of a genetically encoded calcium indicator allowed for the real-time monitoring of intracellular calcium signaling dynamics, including kinetic perturbations that occur upon overexpression of the wild-type or variant version of the calcium signaling relay protein STIM1. A panel of missense mutants of the HIV-1 accessory protein Vif was paired with various paralogs within the human Apobec3 innate immune protein family to identify combinations capable or incapable of interacting within cells. These cells allow transgenic protein variant libraries to be readily paired with assay-specific protein partners or biosensors, enabling new functional readouts for large-scale genetic assays for protein function.
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Affiliation(s)
- Sarah
M. Roelle
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, United States
| | - Nisha D. Kamath
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, United States
| | - Kenneth A. Matreyek
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, United States
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14
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Siddiqui AA, Peter S, Ngoh EZX, Wang CI, Ng S, Dangerfield JA, Gunzburg WH, Dröge P, Makhija H. A versatile genomic transgenesis platform with enhanced λ integrase for human Expi293F cells. Front Bioeng Biotechnol 2023; 11:1198465. [PMID: 37425360 PMCID: PMC10325659 DOI: 10.3389/fbioe.2023.1198465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Accepted: 06/06/2023] [Indexed: 07/11/2023] Open
Abstract
Reliable cell-based platforms to test and/or produce biologics in a sustainable manner are important for the biotech industry. Utilizing enhanced λ integrase, a sequence-specific DNA recombinase, we developed a novel transgenesis platform involving a fully characterized single genomic locus as an artificial landing pad for transgene insertion in human Expi293F cells. Importantly, transgene instability and variation in expression were not observed in the absence of selection pressure, thus enabling reliable long-term biotherapeutics testing or production. The artificial landing pad for λ integrase can be targeted with multi-transgene constructs and offers future modularity involving additional genome manipulation tools to generate sequential or nearly seamless insertions. We demonstrated broad utility with expression constructs for anti PD-1 monoclonal antibodies and showed that the orientation of heavy and light chain transcription units profoundly affected antibody expression levels. In addition, we demonstrated encapsulation of our PD-1 platform cells into bio-compatible mini-bioreactors and the continued secretion of antibodies, thus providing a basis for future cell-based applications for more effective and affordable therapies.
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Affiliation(s)
- Asim Azhar Siddiqui
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Sabrina Peter
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Eve Zi Xian Ngoh
- Singapore Immunology Network, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Cheng-I. Wang
- Singapore Immunology Network, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Shirelle Ng
- Austrianova Singapore Pte. Ltd., Singapore, Singapore
| | | | - Walter H. Gunzburg
- Austrianova Singapore Pte. Ltd., Singapore, Singapore
- Department of Pathobiology, Institute of Virology, University of Veterinary Medicine, Vienna, Austria
| | - Peter Dröge
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
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15
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Zhou L, Yao S. Recent advances in therapeutic CRISPR-Cas9 genome editing: mechanisms and applications. MOLECULAR BIOMEDICINE 2023; 4:10. [PMID: 37027099 PMCID: PMC10080534 DOI: 10.1186/s43556-023-00115-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Accepted: 01/04/2023] [Indexed: 04/08/2023] Open
Abstract
Recently, clustered regularly interspaced palindromic repeats (CRISPR)-Cas9 derived editing tools had significantly improved our ability to make desired changes in the genome. Wild-type Cas9 protein recognizes the target genomic loci and induced local double strand breaks (DSBs) in the guidance of small RNA molecule. In mammalian cells, the DSBs are mainly repaired by endogenous non-homologous end joining (NHEJ) pathway, which is error prone and results in the formation of indels. The indels can be harnessed to interrupt gene coding sequences or regulation elements. The DSBs can also be fixed by homology directed repair (HDR) pathway to introduce desired changes, such as base substitution and fragment insertion, when proper donor templates are provided, albeit in a less efficient manner. Besides making DSBs, Cas9 protein can be mutated to serve as a DNA binding platform to recruit functional modulators to the target loci, performing local transcriptional regulation, epigenetic remolding, base editing or prime editing. These Cas9 derived editing tools, especially base editors and prime editors, can introduce precise changes into the target loci at a single-base resolution and in an efficient and irreversible manner. Such features make these editing tools very promising for therapeutic applications. This review focuses on the evolution and mechanisms of CRISPR-Cas9 derived editing tools and their applications in the field of gene therapy.
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Affiliation(s)
- Lifang Zhou
- Laboratory of Biotherapy, National Key Laboratory of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Renmin Nanlu 17, Chengdu, 610041, Sichuan, China
| | - Shaohua Yao
- Laboratory of Biotherapy, National Key Laboratory of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Renmin Nanlu 17, Chengdu, 610041, Sichuan, China.
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16
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Nakayama M. VCre/VloxP and SCre/SloxP as Reliable Site-Specific Recombination Systems for Genome Engineering. Methods Mol Biol 2023; 2637:161-180. [PMID: 36773146 DOI: 10.1007/978-1-0716-3016-7_13] [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] [Indexed: 04/27/2023]
Abstract
The Cre/loxP system is a versatile and powerful tool that has been used to develop many kinds of genetically modified mice, such as conditional knockout mice and mutant protein-expressing mice through the excision of a STOP cassette. However, while numerous in vivo and in vitro applications of the Cre/loxP system have been reported, it remains difficult to target at one time more than one set of recognition sites in an identical single cell in mice using the Cre/loxP system. To overcome this barrier, we developed two novel site-specific recombination systems called VCre/VloxP and SCre/SloxP. These systems allow multiple independent site-specific recombination, for example, multiple targeted deletions in the same cell at different times. In this chapter, I describe the features of VCre/VloxP and SCre/SloxP, practical protocols and tips on how to use them in genomic engineering applications, potential problems in their use, and how problems can be identified and solved.
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Affiliation(s)
- Manabu Nakayama
- Department of Frontier Research and Development, Kazusa DNA Research Institute, Kisarazu, Chiba, Japan.
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17
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Biggs D, Chen CM, Davies B. Targeted Integration of Transgenes at the Mouse Gt(ROSA)26Sor Locus. Methods Mol Biol 2023; 2631:299-323. [PMID: 36995674 DOI: 10.1007/978-1-0716-2990-1_13] [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] [Indexed: 04/27/2023]
Abstract
The targeting of transgenic constructs at single copy into neutral genomic loci avoids the unpredictable outcomes associated with conventional random integration approaches. The Gt(ROSA)26Sor locus on chromosome 6 has been used many times for the integration of transgenic constructs and is known to be permissive for transgene expression and disruption of the gene is not associated with a known phenotype. Furthermore, the transcript made from the Gt(ROSA)26Sor locus is ubiquitously expressed and subsequently the locus can be used to drive the ubiquitous expression of transgenes.Here we report a protocol for the generation of targeted transgenic alleles at Gt(ROSA)26Sor, taking as an example a conditional overexpression allele, by PhiC31 integrase/recombinase-mediated cassette exchange of an engineered Gt(ROSA)26Sor locus in mouse embryonic stem cells. The overexpression allele is initially silenced by the presence of a loxP flanked stop sequence but can be strongly activated through the action of Cre recombinase.
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Affiliation(s)
- Daniel Biggs
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Chiann-Mun Chen
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Benjamin Davies
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK.
- The Francis Crick Institute, London, UK.
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18
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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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19
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Gottschalk WK, Mahon S, Hodgson D, Barrera J, Hill D, Wei A, Kumar M, Dai K, Anderson L, Mihovilovic M, Lutz MW, Chiba-Falek O. The APOE-TOMM40 Humanized Mouse Model: Characterization of Age, Sex, and PolyT Variant Effects on Gene Expression. J Alzheimers Dis 2023; 94:1563-1576. [PMID: 37458041 PMCID: PMC10733864 DOI: 10.3233/jad-230451] [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] [Indexed: 07/18/2023]
Abstract
BACKGROUND The human chromosome 19q13.32 is a gene rich region and has been associated with multiple phenotypes, including late onset Alzheimer's disease (LOAD) and other age-related conditions. OBJECTIVE Here we developed the first humanized mouse model that contains the entire TOMM40 and APOE genes with all intronic and intergenic sequences including the upstream and downstream regions. Thus, the mouse model carries the human TOMM40 and APOE genes and their intact regulatory sequences. METHODS We generated the APOE-TOMM40 humanized mouse model in which the entire mouse region was replaced with the human (h)APOE-TOMM40 loci including their upstream and downstream flanking regulatory sequences using recombineering technologies. We then measured the expression of the human TOMM40 and APOE genes in the mice brain, liver, and spleen tissues using TaqMan based mRNA expression assays. RESULTS We investigated the effects of the '523' polyT genotype (S/S or VL/VL), sex, and age on the human TOMM40- and APOE-mRNAs expression levels using our new humanized mouse model. The analysis revealed tissue specific and shared effects of the '523' polyT genotype, sex, and age on the regulation of the human TOMM40 and APOE genes. Noteworthy, the regulatory effect of the '523' polyT genotype was observed for all studied organs. CONCLUSION The model offers new opportunities for basic science, translational, and preclinical drug discovery studies focused on the APOE genomic region in relation to LOAD and other conditions in adulthood.
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Affiliation(s)
- William K. Gottschalk
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, USA
| | - Scott Mahon
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, USA
| | - Dellila Hodgson
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, USA
| | - Julio Barrera
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, USA
| | - Delaney Hill
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, USA
| | - Angela Wei
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, USA
| | - Manish Kumar
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, USA
| | - Kathy Dai
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, USA
| | - Lauren Anderson
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, USA
| | - Mirta Mihovilovic
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, USA
| | - Michael W. Lutz
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, USA
| | - Ornit Chiba-Falek
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, USA
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20
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Jin Q, Yang X, Gou S, Liu X, Zhuang Z, Liang Y, Shi H, Huang J, Wu H, Zhao Y, Ouyang Z, Zhang Q, Liu Z, Chen F, Ge W, Xie J, Li N, Lai C, Zhao X, Wang J, Lian M, Li L, Quan L, Ye Y, Lai L, Wang K. Double knock-in pig models with elements of binary Tet-On and phiC31 integrase systems for controllable and switchable gene expression. SCIENCE CHINA. LIFE SCIENCES 2022; 65:2269-2286. [PMID: 35596888 DOI: 10.1007/s11427-021-2088-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 01/20/2022] [Indexed: 06/15/2023]
Abstract
Inducible expression systems are indispensable for precise regulation and in-depth analysis of biological process. Binary Tet-On system has been widely employed to regulate transgenic expression by doxycycline. Previous pig models with tetracycline regulatory elements were generated through random integration. This process often resulted in uncertain expression and unpredictable phenotypes, thus hindering their applications. Here, by precise knock-in of binary Tet-On 3G elements into Rosa26 and Hipp11 locus, respectively, a double knock-in reporter pig model was generated. We characterized excellent properties of this system for controllable transgenic expression both in vitro and in vivo. Two attP sites were arranged to flank the tdTomato to switch reporter gene. Single or multiple gene replacement was efficiently and faithfully achieved in fetal fibroblasts and nuclear transfer embryos. To display the flexible application of this system, we generated a pig strain with Dox-inducing hKRASG12D expression through phiC31 integrase-mediated cassette exchange. After eight months of Dox administration, squamous cell carcinoma developed in the nose, mouth, and scrotum, which indicated this pig strain could serve as an ideal large animal model to study tumorigenesis. Overall, the established pig models with controllable and switchable transgene expression system will provide a facilitating platform for transgenic and biomedical research.
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Affiliation(s)
- Qin Jin
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou, 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Centre for Regenerative Medicine and Health, Hong Kong Institute of Science and Innovation, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
- Sanya institute of Swine resource, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Hainan Provincial Research Center of Laboratory Animals, Sanya, 572000, China
- Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou, 510530, China
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510005, China
| | - Xiaoyu Yang
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou, 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Centre for Regenerative Medicine and Health, Hong Kong Institute of Science and Innovation, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
- Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou, 510530, China
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510005, China
| | - Shixue Gou
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou, 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Centre for Regenerative Medicine and Health, Hong Kong Institute of Science and Innovation, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
- Sanya institute of Swine resource, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Hainan Provincial Research Center of Laboratory Animals, Sanya, 572000, China
- Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou, 510530, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510005, China
| | - Xiaoyi Liu
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou, 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Centre for Regenerative Medicine and Health, Hong Kong Institute of Science and Innovation, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
- Sanya institute of Swine resource, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Hainan Provincial Research Center of Laboratory Animals, Sanya, 572000, China
- Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou, 510530, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510005, China
| | - Zhenpeng Zhuang
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou, 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Centre for Regenerative Medicine and Health, Hong Kong Institute of Science and Innovation, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
- Sanya institute of Swine resource, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Hainan Provincial Research Center of Laboratory Animals, Sanya, 572000, China
- Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou, 510530, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510005, China
| | - Yanhui Liang
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou, 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Centre for Regenerative Medicine and Health, Hong Kong Institute of Science and Innovation, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
- Sanya institute of Swine resource, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Hainan Provincial Research Center of Laboratory Animals, Sanya, 572000, China
- Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou, 510530, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510005, China
| | - Hui Shi
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou, 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Centre for Regenerative Medicine and Health, Hong Kong Institute of Science and Innovation, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
- Sanya institute of Swine resource, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Hainan Provincial Research Center of Laboratory Animals, Sanya, 572000, China
- Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou, 510530, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510005, China
| | - Jiayuan Huang
- Guangdong Provincial Key Laboratory of Laboratory Animals, Guangdong Laboratory Animals Monitoring Institute, Guangzhou, 510633, China
| | - Han Wu
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou, 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Centre for Regenerative Medicine and Health, Hong Kong Institute of Science and Innovation, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
- Sanya institute of Swine resource, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Hainan Provincial Research Center of Laboratory Animals, Sanya, 572000, China
- Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou, 510530, China
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510005, China
| | - Yu Zhao
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou, 510530, China
- Sanya institute of Swine resource, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Hainan Provincial Research Center of Laboratory Animals, Sanya, 572000, China
- Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou, 510530, China
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510005, China
- Guangdong Provincial Key Laboratory of Large Animal models for Biomedicine, Wuyi University, Jiangmen, 529020, China
| | - Zhen Ouyang
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou, 510530, China
- Sanya institute of Swine resource, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Hainan Provincial Research Center of Laboratory Animals, Sanya, 572000, China
- Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou, 510530, China
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510005, China
- Guangdong Provincial Key Laboratory of Large Animal models for Biomedicine, Wuyi University, Jiangmen, 529020, China
| | - Quanjun Zhang
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou, 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Centre for Regenerative Medicine and Health, Hong Kong Institute of Science and Innovation, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
- Sanya institute of Swine resource, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Hainan Provincial Research Center of Laboratory Animals, Sanya, 572000, China
- Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou, 510530, China
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510005, China
| | - Zhaoming Liu
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou, 510530, China
- Sanya institute of Swine resource, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Hainan Provincial Research Center of Laboratory Animals, Sanya, 572000, China
- Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou, 510530, China
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510005, China
- Guangdong Provincial Key Laboratory of Large Animal models for Biomedicine, Wuyi University, Jiangmen, 529020, China
| | - Fangbing Chen
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou, 510530, China
- Sanya institute of Swine resource, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Hainan Provincial Research Center of Laboratory Animals, Sanya, 572000, China
- Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou, 510530, China
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510005, China
- Guangdong Provincial Key Laboratory of Large Animal models for Biomedicine, Wuyi University, Jiangmen, 529020, China
| | - Weikai Ge
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou, 510530, China
- Sanya institute of Swine resource, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Hainan Provincial Research Center of Laboratory Animals, Sanya, 572000, China
- Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou, 510530, China
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510005, China
- Guangdong Provincial Key Laboratory of Large Animal models for Biomedicine, Wuyi University, Jiangmen, 529020, China
| | - Jingke Xie
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou, 510530, China
- Sanya institute of Swine resource, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Hainan Provincial Research Center of Laboratory Animals, Sanya, 572000, China
- Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou, 510530, China
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510005, China
- Guangdong Provincial Key Laboratory of Large Animal models for Biomedicine, Wuyi University, Jiangmen, 529020, China
| | - Nan Li
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou, 510530, China
- Sanya institute of Swine resource, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Hainan Provincial Research Center of Laboratory Animals, Sanya, 572000, China
- Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou, 510530, China
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510005, China
- Guangdong Provincial Key Laboratory of Large Animal models for Biomedicine, Wuyi University, Jiangmen, 529020, China
| | - Chengdan Lai
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou, 510530, China
- Sanya institute of Swine resource, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Hainan Provincial Research Center of Laboratory Animals, Sanya, 572000, China
- Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou, 510530, China
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510005, China
- Guangdong Provincial Key Laboratory of Large Animal models for Biomedicine, Wuyi University, Jiangmen, 529020, China
| | - Xiaozhu Zhao
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou, 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Centre for Regenerative Medicine and Health, Hong Kong Institute of Science and Innovation, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
- Sanya institute of Swine resource, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Hainan Provincial Research Center of Laboratory Animals, Sanya, 572000, China
- Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou, 510530, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510005, China
| | - Jiaowei Wang
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou, 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Centre for Regenerative Medicine and Health, Hong Kong Institute of Science and Innovation, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
- Sanya institute of Swine resource, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Hainan Provincial Research Center of Laboratory Animals, Sanya, 572000, China
- Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou, 510530, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510005, China
| | - Meng Lian
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou, 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Centre for Regenerative Medicine and Health, Hong Kong Institute of Science and Innovation, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
- Sanya institute of Swine resource, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Hainan Provincial Research Center of Laboratory Animals, Sanya, 572000, China
- Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou, 510530, China
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510005, China
| | - Lei Li
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou, 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Centre for Regenerative Medicine and Health, Hong Kong Institute of Science and Innovation, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
- Sanya institute of Swine resource, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Hainan Provincial Research Center of Laboratory Animals, Sanya, 572000, China
- Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou, 510530, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510005, China
| | - Longquan Quan
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou, 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Centre for Regenerative Medicine and Health, Hong Kong Institute of Science and Innovation, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
- Sanya institute of Swine resource, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Hainan Provincial Research Center of Laboratory Animals, Sanya, 572000, China
- Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou, 510530, China
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510005, China
| | - Yinghua Ye
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou, 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Centre for Regenerative Medicine and Health, Hong Kong Institute of Science and Innovation, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
- Sanya institute of Swine resource, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Hainan Provincial Research Center of Laboratory Animals, Sanya, 572000, China
- Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou, 510530, China
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510005, China
| | - Liangxue Lai
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou, 510530, China.
- Sanya institute of Swine resource, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Hainan Provincial Research Center of Laboratory Animals, Sanya, 572000, China.
- Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou, 510530, China.
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510005, China.
- Guangdong Provincial Key Laboratory of Large Animal models for Biomedicine, Wuyi University, Jiangmen, 529020, China.
| | - Kepin Wang
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou, 510530, China.
- Sanya institute of Swine resource, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Hainan Provincial Research Center of Laboratory Animals, Sanya, 572000, China.
- Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou, 510530, China.
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510005, China.
- Guangdong Provincial Key Laboratory of Large Animal models for Biomedicine, Wuyi University, Jiangmen, 529020, China.
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21
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Blanch-Asensio A, Grandela C, Brandão KO, de Korte T, Mei H, Ariyurek Y, Yiangou L, Mol MP, van Meer BJ, Kloet SL, Mummery CL, Davis RP. STRAIGHT-IN enables high-throughput targeting of large DNA payloads in human pluripotent stem cells. CELL REPORTS METHODS 2022; 2:100300. [PMID: 36313798 PMCID: PMC9606106 DOI: 10.1016/j.crmeth.2022.100300] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 07/12/2022] [Accepted: 08/31/2022] [Indexed: 04/20/2023]
Abstract
Inserting large DNA payloads (>10 kb) into specific genomic sites of mammalian cells remains challenging. Applications ranging from synthetic biology to evaluating the pathogenicity of disease-associated variants for precision medicine initiatives would greatly benefit from tools that facilitate this process. Here, we merge the strengths of different classes of site-specific recombinases and combine these with CRISPR-Cas9-mediated homologous recombination to develop a strategy for stringent site-specific replacement of genomic fragments at least 50 kb in size in human induced pluripotent stem cells (hiPSCs). We demonstrate the versatility of STRAIGHT-IN (serine and tyrosine recombinase-assisted integration of genes for high-throughput investigation) by (1) inserting various combinations of fluorescent reporters into hiPSCs to assess the excitation-contraction coupling cascade in derivative cardiomyocytes and (2) simultaneously targeting multiple variants associated with inherited cardiac arrhythmic disorders into a pool of hiPSCs. STRAIGHT-IN offers a precise approach to generate genetically matched panels of hiPSC lines efficiently and cost effectively.
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Affiliation(s)
- Albert Blanch-Asensio
- Department of Anatomy and Embryology, Leiden University Medical Center, 2300RC Leiden, the Netherlands
| | - Catarina Grandela
- Department of Anatomy and Embryology, Leiden University Medical Center, 2300RC Leiden, the Netherlands
| | - Karina O. Brandão
- Department of Anatomy and Embryology, Leiden University Medical Center, 2300RC Leiden, the Netherlands
| | - Tessa de Korte
- Department of Anatomy and Embryology, Leiden University Medical Center, 2300RC Leiden, the Netherlands
| | - Hailiang Mei
- Sequencing Analysis Support Core, Leiden University Medical Center, 2333RC Leiden, the Netherlands
| | - Yavuz Ariyurek
- Leiden Genome Technology Center, Leiden University Medical Center, 2333RC Leiden, the Netherlands
| | - Loukia Yiangou
- Department of Anatomy and Embryology, Leiden University Medical Center, 2300RC Leiden, the Netherlands
| | - Mervyn P.H. Mol
- Department of Anatomy and Embryology, Leiden University Medical Center, 2300RC Leiden, the Netherlands
| | - Berend J. van Meer
- Department of Anatomy and Embryology, Leiden University Medical Center, 2300RC Leiden, the Netherlands
| | - Susan L. Kloet
- Leiden Genome Technology Center, Leiden University Medical Center, 2333RC Leiden, the Netherlands
| | - Christine L. Mummery
- Department of Anatomy and Embryology, Leiden University Medical Center, 2300RC Leiden, the Netherlands
- Department of Applied Stem Cell Technologies, University of Twente, 7500AE Enschede, the Netherlands
| | - Richard P. Davis
- Department of Anatomy and Embryology, Leiden University Medical Center, 2300RC Leiden, the Netherlands
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22
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Yang W, Zhang J, Xiao Y, Li W, Wang T. Screening Strategies for High-Yield Chinese Hamster Ovary Cell Clones. Front Bioeng Biotechnol 2022; 10:858478. [PMID: 35782513 PMCID: PMC9247297 DOI: 10.3389/fbioe.2022.858478] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 05/23/2022] [Indexed: 12/20/2022] Open
Abstract
Chinese hamster ovary (CHO) cells are by far the most commonly used mammalian expression system for recombinant expression of therapeutic proteins in the pharmaceutical industry. The development of high-yield stable cell lines requires processes of transfection, selection, screening and adaptation, among which the screening process requires tremendous time and determines the level of forming highly productive monoclonal cell lines. Therefore, how to achieve productive cell lines is a major question prior to industrial manufacturing. Cell line development (CLD) is one of the most critical steps in the production of recombinant therapeutic proteins. Generation of high-yield cell clones is mainly based on the time-consuming, laborious process of selection and screening. With the increase in recombinant therapeutic proteins expressed by CHO cells, CLD has become a major bottleneck in obtaining cell lines for manufacturing. The basic principles for CLD include preliminary screening for high-yield cell pool, single-cell isolation and improvement of productivity, clonality and stability. With the development of modern analysis and testing technologies, various screening methods have been used for CLD to enhance the selection efficiency of high-yield clonal cells. This review provides a comprehensive overview on preliminary screening methods for high-yield cell pool based on drug selective pressure. Moreover, we focus on high throughput methods for isolating high-yield cell clones and increasing the productivity and stability, as well as new screening strategies used for the biopharmaceutical industry.
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Affiliation(s)
- Wenwen Yang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, China
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang, China
| | - Junhe Zhang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, China
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang, China
- Institutes of Health Central Plains, Xinxiang Medical University, Xinxiang, China
- *Correspondence: Tianyun Wang, ; Junhe Zhang,
| | - Yunxi Xiao
- Institutes of Health Central Plains, Xinxiang Medical University, Xinxiang, China
| | - Wenqing Li
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, China
| | - Tianyun Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, China
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang, China
- *Correspondence: Tianyun Wang, ; Junhe Zhang,
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23
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Liu L, Zhang J, Teng T, Yang Y, Zhang W, Wu W, Li G, Zheng X. Electroporation of His-Cre fusion protein triggers a specific recombinase-mediated cassette exchange in HEK 293T cells. Protein Expr Purif 2022; 198:106128. [PMID: 35667585 DOI: 10.1016/j.pep.2022.106128] [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: 03/17/2022] [Revised: 05/31/2022] [Accepted: 05/31/2022] [Indexed: 10/18/2022]
Abstract
Cre recombinase is a widely-used genetic manipulation of genomic DNA. However, the conventional transfection of the DNA vectors expressing the Cre recombinase or viral transduction method yields low transfection efficiencies or insertion mutagenesis. The present paper evaluated whether the direct protein delivery of Cre recombinase through electroporation can induce the Cre-mediated recombination in the HEK 293T cells. Here, the small ubiquitin-related modifier (SUMO) -tagged His-Cre fusion protein was expressed in a soluble pattern in the Eschrichria coli (E.coli) cells, purified using affinity chromatography, and finally electroporated into the HEK 293T cells. These cells were previously transfected with three different Cre reporter vectors. The electroporation of the HEK 293T cells revealed either the activation of EGFP expression, or a decrease in RFP expression, and a concomitant increase in EGFP expression, indicating a desired recombinase-mediated cassette exchange (RMCE) event (conversion of RFP to EGFP), and a biological activity of the purified SUMO-His-Cre protein, which is expected to serve in the Easi-CRISPR-LoxP-mediated genome editing to generate transgenic animal models.
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Affiliation(s)
- Lingkang Liu
- Department of Animal Medicine, College of Animal Science and Technology, Guangxi University, No. 100 Daxue Road, Nanning, 530004, Guangxi, PR China
| | - Jiashun Zhang
- Department of Animal Medicine, College of Animal Science and Technology, Guangxi University, No. 100 Daxue Road, Nanning, 530004, Guangxi, PR China
| | - Ting Teng
- Department of Animal Medicine, College of Animal Science and Technology, Guangxi University, No. 100 Daxue Road, Nanning, 530004, Guangxi, PR China
| | - Yang Yang
- Department of Animal Medicine, College of Animal Science and Technology, Guangxi University, No. 100 Daxue Road, Nanning, 530004, Guangxi, PR China
| | - Wanyu Zhang
- Department of Animal Medicine, College of Animal Science and Technology, Guangxi University, No. 100 Daxue Road, Nanning, 530004, Guangxi, PR China
| | - Wende Wu
- Department of Animal Medicine, College of Animal Science and Technology, Guangxi University, No. 100 Daxue Road, Nanning, 530004, Guangxi, PR China
| | - Gonghe Li
- Department of Animal Medicine, College of Animal Science and Technology, Guangxi University, No. 100 Daxue Road, Nanning, 530004, Guangxi, PR China
| | - Xibang Zheng
- Department of Animal Medicine, College of Animal Science and Technology, Guangxi University, No. 100 Daxue Road, Nanning, 530004, Guangxi, PR China.
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24
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Tsai SJ, Ai Y, Guo C, Gould SJ. Degron tagging of BleoR and other antibiotic-resistance genes selects for higher expression of linked transgenes and improved exosome engineering. J Biol Chem 2022; 298:101846. [PMID: 35314197 PMCID: PMC9111990 DOI: 10.1016/j.jbc.2022.101846] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 03/15/2022] [Accepted: 03/16/2022] [Indexed: 12/24/2022] Open
Abstract
Five antibiotic resistance (AR) genes have been used to select for transgenic eukaryotic cell lines, with the BleoR, PuroR, HygR, NeoR, and BsdR cassettes conferring resistance to zeocin, puromycin, hygromycin, geneticin/G418, and blasticidin, respectively. We recently demonstrated that each AR gene establishes a distinct threshold of transgene expression below which no cell can survive, with BleoR selecting for the highest level of transgene expression, nearly ∼10-fold higher than in cells selected using the NeoR or BsdR markers. Here, we tested the hypothesis that there may be an inverse proportionality between AR protein function and the expression of linked, transgene-encoded, recombinant proteins. Specifically, we fused each AR protein to proteasome-targeting degron tags, used these to select for antibiotic-resistant cell lines, and then measured the expression of the linked, recombinant protein, mCherry, as a proxy marker of transgene expression. In each case, degron-tagged AR proteins selected for higher mCherry expression than their cognate WT AR proteins. ER50BleoR selected for the highest level of mCherry expression, greater than twofold higher than BleoR or any other AR gene. Interestingly, use of ER50BleoR as the selectable marker translated to an even higher, 3.5-fold increase in the exosomal loading of the exosomal cargo protein, CD63/Y235A. Although a putative CD63-binding peptide, CP05, has been used to decorate exosome membranes in a technology known as "exosome painting," we show here that CP05 binds equally well to CD63-/- cells, WT 293F cells, and CD63-overexpressing cells, indicating that CP05 may bind membranes nonspecifically. These results are of high significance for cell engineering and especially for exosome engineering.
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Affiliation(s)
- Shang Jui Tsai
- Department of Biological Chemistry, Johns Hopkins University, Baltimore, Maryland, USA
| | - Yiwei Ai
- Department of Biological Chemistry, Johns Hopkins University, Baltimore, Maryland, USA
| | - Chenxu Guo
- Department of Biological Chemistry, Johns Hopkins University, Baltimore, Maryland, USA
| | - Stephen J Gould
- Department of Biological Chemistry, Johns Hopkins University, Baltimore, Maryland, USA.
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25
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Oliviero C, Hinz SC, Bogen JP, Kornmann H, Hock B, Kolmar H, Hagens G. Generation of a Host Cell line containing a MAR-rich landing pad for site-specific integration and expression of transgenes. Biotechnol Prog 2022; 38:e3254. [PMID: 35396920 PMCID: PMC9539524 DOI: 10.1002/btpr.3254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 03/22/2022] [Accepted: 03/31/2022] [Indexed: 11/10/2022]
Abstract
In recent years, targeted gene integration (TI) has been introduced as a strategy for the generation of recombinant mammalian cell lines for the production of biotherapeutics. Besides reducing the immense heterogeneity within a pool of recombinant transfectants, TI also aims at shortening the duration of the current cell line development process. Here we describe the generation of a host cell line carrying Matrix‐Attachment Region (MAR)‐rich landing pads (LPs), which allow for the simultaneous and site‐specific integration of multiple genes of interest (GOIs). We show that several copies of each chicken lysozyme 5'MAR‐based LP containing either BxB1 wild type or mutated recombination sites, integrated at one random chromosomal locus of the host cell genome. We further demonstrate that these LP‐containing host cell lines can be used for the site‐specific integration of several GOIs and thus, generation of transgene‐expressing stable recombinant clones. Transgene expression was shown by site‐specific integration of heavy and light chain genes coding for a monospecific antibody (msAb) as well as for a bi‐specific antibody (bsAb). The genetic stability of the herein described LP‐based recombinant clones expressing msAb or bsAb was demonstrated by cultivating the recombinant clones and measuring antibody titers over 85 generations. We conclude that the host cell containing multiple copies of MAR‐rich landing pads can be successfully used for stable expression of one or several GOIs.
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Affiliation(s)
- Claudia Oliviero
- Institute of Life Technology, Haute Ecole d'Ingénierie HES-SO Valais Wallis, Rue de l'Industrie 19, CH-1950 Sion, Switzerland
| | - Steffen C Hinz
- Institute of Life Technology, Haute Ecole d'Ingénierie HES-SO Valais Wallis, Rue de l'Industrie 19, CH-1950 Sion, Switzerland
| | - Jan P Bogen
- Institute for Organic Chemistry and Biochemistry, Technical University of Darmstadt, Alarich-Weiss-Strasse 4, D-64287, Darmstadt, Germany
| | - Henri Kornmann
- Ferring Biologics Innovation Center, Route de la Corniche 8, CH-1066, Epalinges, Switzerland
| | - Björn Hock
- Ferring Biologics Innovation Center, Route de la Corniche 8, CH-1066, Epalinges, Switzerland.,SwissThera SA, Route de la Corniche 4, CH-1066, Epalinges, Switzerland
| | - Harald Kolmar
- Institute for Organic Chemistry and Biochemistry, Technical University of Darmstadt, Alarich-Weiss-Strasse 4, D-64287, Darmstadt, Germany
| | - Gerrit Hagens
- Institute of Life Technology, Haute Ecole d'Ingénierie HES-SO Valais Wallis, Rue de l'Industrie 19, CH-1950 Sion, Switzerland
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26
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Efficient targeted transgenesis of large donor DNA into multiple mouse genetic backgrounds using bacteriophage Bxb1 integrase. Sci Rep 2022; 12:5424. [PMID: 35361849 PMCID: PMC8971409 DOI: 10.1038/s41598-022-09445-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 03/23/2022] [Indexed: 12/12/2022] Open
Abstract
The development of mouse models of human disease and synthetic biology research by targeted transgenesis of large DNA constructs represent a significant genetic engineering hurdle. We developed an efficient, precise, single-copy integration of large transgenes directly into zygotes using multiple mouse genetic backgrounds. We used in vivo Bxb1 mediated recombinase-mediated cassette exchange (RMCE) with a transgene “landing pad” composed of dual heterologous Bxb1 attachment (att) sites in cis, within the Gt(ROSA)26Sor safe harbor locus. RMCE of donor was achieved by microinjection of vector DNA carrying cognate attachment sites flanking the donor transgene with Bxb1-integrase mRNA. This approach achieves perfect vector-free integration of donor constructs at efficiencies > 40% with up to ~ 43 kb transgenes. Coupled with a nanopore-based Cas9-targeted sequencing (nCATS), complete verification of precise insertion sequence was achieved. As a proof-of-concept we describe the development of C57BL/6J and NSG Krt18-ACE2 models for SARS-CoV2 research with verified heterozygous N1 animals within ~ 4 months. Additionally, we created a series of mice with diverse backgrounds carrying a single att site including FVB/NJ, PWK/PhJ, NOD/ShiLtJ, CAST/EiJ and DBA/2J allowing for rapid transgene insertion. Combined, this system enables predictable, rapid development with simplified characterization of precisely targeted transgenic animals across multiple genetic backgrounds.
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Teixeira AP, Stücheli P, Ausländer S, Ausländer D, Schönenberger P, Hürlemann S, Fussenegger M. CelloSelect - A synthetic cellobiose metabolic pathway for selection of stable transgenic CHO cell lines. Metab Eng 2022; 70:23-30. [PMID: 35007751 DOI: 10.1016/j.ymben.2022.01.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/30/2021] [Accepted: 01/03/2022] [Indexed: 11/30/2022]
Abstract
Current protocols for generating stable transgenic cell lines mostly rely on antibiotic selection or the use of specialized cell lines lacking an essential part of their metabolic machinery, but these approaches require working with either toxic chemicals or knockout cell lines, which can reduce productivity. Since most mammalian cells cannot utilize cellobiose, a disaccharide consisting of two β-1,4-linked glucose molecules, we designed an antibiotic-free selection system, CelloSelect, which consists of a selection cassette encoding Neurospora crassa cellodextrin transporter CDT1 and β-glucosidase GH1-1. When cultivated in glucose-free culture medium containing cellobiose, CelloSelect-transfected cells proliferate by metabolizing cellobiose as a primary energy source, and are protected from glucose starvation. We show that the combination of CelloSelect with a PiggyBac transposase-based integration strategy provides a platform for the swift and efficient generation of stable transgenic cell lines. Growth rate analysis of metabolically engineered cells in cellobiose medium confirmed the expansion of cells stably expressing high levels of a cargo fluorescent marker protein. We further validated this strategy by applying the CelloSelect system for stable integration of sequences encoding two biopharmaceutical proteins, erythropoietin and the monoclonal antibody rituximab, and confirmed that the proteins are efficiently produced in either cellobiose- or glucose-containing medium in suspension-adapted CHO cells cultured in chemically defined media. We believe coupling heterologous metabolic pathways additively to the endogenous metabolism of mammalian cells has the potential to complement or to replace current cell-line selection systems.
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Affiliation(s)
- Ana P Teixeira
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - Pascal Stücheli
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - Simon Ausländer
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - David Ausländer
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - Pascal Schönenberger
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - Samuel Hürlemann
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - Martin Fussenegger
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, CH-4058, Basel, Switzerland; Faculty of Science, University of Basel, Mattenstrasse 26, CH-4058, Basel, Switzerland.
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Furukawa A, Tanaka A, Yamaguchi S, Kosuda M, Yamana M, Nagasawa A, Kohno G, Ishihara H. Using recombinase-mediated cassette exchange to engineer MIN6 insulin-secreting cells based on a newly identified safe harbor locus. J Diabetes Investig 2021; 12:2129-2140. [PMID: 34382357 PMCID: PMC8668067 DOI: 10.1111/jdi.13646] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 08/03/2021] [Accepted: 08/09/2021] [Indexed: 12/04/2022] Open
Abstract
AIMS/INTRODUCTION Recent studies have identified genomic and transcript level changes along with alterations in insulin secretion in patients with diabetes and in rodent models of diabetes. It is important to establish an efficient system for testing functional consequences of these changes. We aimed to generate such a system using insulin-secreting MIN6 cells. MATERIALS AND METHODS MIN6 cells were first engineered to have a tetracycline-regulated expression system. Then, we used the recombination-mediated cassette exchange strategy to explore the silencing-resistant site in the genome and generated a master cell line based on this site. RESULTS We identified a site 10.5 kbps upstream from the Zxdb gene as a locus that allows homogenous transgene expression from a tetracycline responsible promoter. Placing the Flip/Frt-based platform on this locus using CRISPR/Cas9 technology generated modified MIN6 cells applicable to achieving cassette exchange on the genome. Using this cell line, we generated MIN6 subclones with over- or underexpression of glucokinase. By analyzing a mixed population of these cells, we obtained an initial estimate of effects on insulin secretion within 6 weeks. Furthermore, we generated six MIN6 cell sublines simultaneously harboring genes of inducible overexpression with unknown functions in insulin secretion, and found that Cited4 and Arhgef3 overexpressions increased and decreased insulin secretion, respectively. CONCLUSIONS We engineered MIN6 cells, which can serve as a powerful tool for testing genetic alterations associated with diabetes, and studied the molecular mechanisms of insulin secretion.
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Affiliation(s)
- Asami Furukawa
- Division of Diabetes and Metabolic DiseasesNihon University School of MedicineItabashiJapan
| | - Aya Tanaka
- Division of Diabetes and Metabolic DiseasesNihon University School of MedicineItabashiJapan
| | - Suguru Yamaguchi
- Division of Diabetes and Metabolic DiseasesNihon University School of MedicineItabashiJapan
| | - Minami Kosuda
- Division of Diabetes and Metabolic DiseasesNihon University School of MedicineItabashiJapan
| | - Midori Yamana
- Division of Diabetes and Metabolic DiseasesNihon University School of MedicineItabashiJapan
| | - Akiko Nagasawa
- Division of Diabetes and Metabolic DiseasesNihon University School of MedicineItabashiJapan
| | - Genta Kohno
- Division of Diabetes and Metabolic DiseasesNihon University School of MedicineItabashiJapan
| | - Hisamitsu Ishihara
- Division of Diabetes and Metabolic DiseasesNihon University School of MedicineItabashiJapan
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Cre/Lox-based RMCE for Site-specific Integration in CHO Cells. BIOTECHNOL BIOPROC E 2021. [DOI: 10.1007/s12257-020-0332-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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30
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Liu C, Cui Z, Yan Y, Wu NL, Li L, Ying Q, Peng L. An optimized proliferation system of embryonic stem cells for generating the rat model with large fragment modification. Biochem Biophys Res Commun 2021; 571:8-13. [PMID: 34298338 DOI: 10.1016/j.bbrc.2021.07.053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 07/15/2021] [Indexed: 11/25/2022]
Abstract
Rats have long been an ideal model for disease research in the field of biomedicine, but the bottleneck of in vitro culture of rat embryonic stem (ES) cells hindered the wide application as genetic disease models. Here, we optimized a special medium which we named 5N-medium for rat embryonic stem cells, which improved the in vitro cells with better morphology and higher pluripotency. We then established a drug selection schedule harboring a prior selection of 12 h that achieved a higher positive selection ratio. These treatments induced at least 50% increase of homologous recombination efficiency compared with conventional 2i culture condition. Moreover, the ratio of euploid ES clones also increased by 50% with a higher germline transmission rate. Finally, we successfully knocked in a 175 kb human Bacterial Artificial Chromosome (BAC) fragment to rat ES genome through recombinase mediated cassette exchange (RMCE). Hence, we provide a promising system for generating sophisticated rat models which could be benefit for biomedical researches.
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Affiliation(s)
- Chang Liu
- Key Laboratory of Arrhythmias, Ministry of Education of China, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, 200120, China; Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, 200120, China; Department of Medical Genetics, Tongji University School of Medicine, Shanghai, 200092, China
| | - Zhonglin Cui
- Division of Hepatobiliopancreatic Surgery, Department of General Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, 510515, China; Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research at USC, Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Youzhen Yan
- USC/Norris Cancer Center Transgenic/Knockout Rodent Core Facility, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Nancy L Wu
- USC/Norris Cancer Center Transgenic/Knockout Rodent Core Facility, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Li Li
- Key Laboratory of Arrhythmias, Ministry of Education of China, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, 200120, China; Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, 200120, China; Department of Medical Genetics, Tongji University School of Medicine, Shanghai, 200092, China; Research Units of Origin and Regulation of Heart Rhythm, Chinese Academy of Medical Sciences, Beijing, 100730, China.
| | - Qilong Ying
- Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research at USC, Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA; USC/Norris Cancer Center Transgenic/Knockout Rodent Core Facility, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA.
| | - Luying Peng
- Key Laboratory of Arrhythmias, Ministry of Education of China, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, 200120, China; Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, 200120, China; Department of Medical Genetics, Tongji University School of Medicine, Shanghai, 200092, China; Research Units of Origin and Regulation of Heart Rhythm, Chinese Academy of Medical Sciences, Beijing, 100730, China.
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31
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Guo C, Fordjour FK, Tsai SJ, Morrell JC, Gould SJ. Choice of selectable marker affects recombinant protein expression in cells and exosomes. J Biol Chem 2021; 297:100838. [PMID: 34051235 PMCID: PMC8258971 DOI: 10.1016/j.jbc.2021.100838] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 04/14/2021] [Accepted: 05/25/2021] [Indexed: 11/19/2022] Open
Abstract
Transgenic mammalian cells are used for numerous research, pharmaceutical, industrial, and clinical purposes, and dominant selectable markers are often used to enable the selection of transgenic cell lines. Using HEK293 cells, we show here that the choice of selectable marker gene has a significant impact on both the level of recombinant protein expression and the cell-to-cell variability in recombinant protein expression. Specifically, we observed that cell lines generated with the NeoR or BsdR selectable markers and selected in the antibiotics G418 or blasticidin, respectively, displayed the lowest level of recombinant protein expression as well as the greatest cell-to-cell variability in transgene expression. In contrast, cell lines generated with the BleoR marker and selected in zeocin yielded cell lines that expressed the highest levels of linked recombinant protein, approximately 10-fold higher than those selected using the NeoR or BsdR markers, as well as the lowest cell-to-cell variability in recombinant protein expression. Intermediate yet still-high levels of expression were observed in cells generated with the PuroR- or HygR-based vectors and that were selected in puromycin or hygromycin, respectively. Similar results were observed in the African green monkey cell line COS7. These data indicate that each combination of selectable marker and antibiotic establishes a threshold below which no cell can survive and that these thresholds vary significantly between different selectable markers. Moreover, we show that choice of selectable marker also affects recombinant protein expression in cell-derived exosomes, consistent with the hypothesis that exosome protein budding is a stochastic rather than determinative process.
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Affiliation(s)
- Chenxu Guo
- Department of Biological Chemistry, School of Medicine, Johns Hopkins University, Baltimore Maryland, USA
| | - Francis K Fordjour
- Department of Biological Chemistry, School of Medicine, Johns Hopkins University, Baltimore Maryland, USA
| | - Shang Jui Tsai
- Department of Biological Chemistry, School of Medicine, Johns Hopkins University, Baltimore Maryland, USA
| | - James C Morrell
- Department of Biological Chemistry, School of Medicine, Johns Hopkins University, Baltimore Maryland, USA
| | - Stephen J Gould
- Department of Biological Chemistry, School of Medicine, Johns Hopkins University, Baltimore Maryland, USA.
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32
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Zheng F, Kawabe Y, Murakami M, Takahashi M, Nishihata K, Yoshida S, Ito A, Kamihira M. LINE-1 vectors mediate recombinant antibody gene transfer by retrotransposition in Chinese hamster ovary cells. Biotechnol J 2021; 16:e2000620. [PMID: 33938150 DOI: 10.1002/biot.202000620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 04/26/2021] [Accepted: 04/28/2021] [Indexed: 11/09/2022]
Abstract
Retrotransposons, such as long interspersed element-1 (LINE-1), can copy themselves to other genomic loci via a transposition event (termed retrotransposition). Retrotransposons, therefore, have potential use as an efficient gene delivery tool to integrate multiple copies of a target gene into a host genome. Here, we developed a retrotransposon vector based on LINE-1 that achieves target gene integration of multiple transgene copies. The retrotransposon vector contains a neomycin resistance gene split by an intron as a marker gene, and a gene encoding an antibody single-chain variable fragment (Fv) fused with the constant antibody region (Fc) (scFv-Fc) as a model target gene. G418-resistant Chinese hamster ovary cells were generated using this retrotransposon vector, and scFv-Fc was produced in the culture medium. To regulate retrotransposition, we developed a retrotransposon vector system that separately expressed the two open reading frames (ORF1 and ORF2) of LINE-1. Genomic PCR analysis detected the transgene sequence in almost all tested clones. Compared with clones established using the intact LINE-1 vector, clones generated with the split ORF1 and ORF2 system showed similar specific scFv-Fc productivity and retrotransposition efficiency. This approach of using a retrotransposon-based vector system has the potential to provide a new gene delivery tool for mammalian cells.
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Affiliation(s)
- Feiyang Zheng
- Graduate School of Systems Life Sciences, Kyushu University, Nishi-ku, Fukuoka, Japan
| | - Yoshinori Kawabe
- Department of Chemical Engineering, Faculty of Engineering, Kyushu University, Nishi-ku, Fukuoka, Japan
| | - Mai Murakami
- Graduate School of Systems Life Sciences, Kyushu University, Nishi-ku, Fukuoka, Japan
| | - Mamika Takahashi
- Department of Chemical Engineering, Faculty of Engineering, Kyushu University, Nishi-ku, Fukuoka, Japan
| | - Kyoka Nishihata
- Department of Chemical Engineering, Faculty of Engineering, Kyushu University, Nishi-ku, Fukuoka, Japan
| | - Souichiro Yoshida
- Department of Chemical Engineering, Faculty of Engineering, Kyushu University, Nishi-ku, Fukuoka, Japan
| | - Akira Ito
- Department of Chemical Engineering, Faculty of Engineering, Kyushu University, Nishi-ku, Fukuoka, Japan
| | - Masamichi Kamihira
- Graduate School of Systems Life Sciences, Kyushu University, Nishi-ku, Fukuoka, Japan.,Department of Chemical Engineering, Faculty of Engineering, Kyushu University, Nishi-ku, Fukuoka, Japan
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33
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Tevelev B, Patel H, Shields K, Wei W, Cooley C, Zhang S, Bitzas G, Duan W, Khetemenee L, Jackobek R, D'Antona A, Sievers A, King A, Tam A, Zhang Y, Sousa E, Cohen J, Wroblewska L, Marshall J, Jackson M, Scarcelli JJ. Genetic rearrangement during site specific integration event facilitates cell line development of a bispecific molecule. Biotechnol Prog 2021; 37:e3158. [PMID: 33891804 PMCID: PMC8459265 DOI: 10.1002/btpr.3158] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 04/16/2021] [Accepted: 04/19/2021] [Indexed: 11/13/2022]
Abstract
Site specific integration (SSI) expression systems offer robust means of generating highly productive and stable cell lines for traditional monoclonal antibodies. As complex modalities such as antibody‐like molecules comprised of greater than two peptides become more prevalent, greater emphasis needs to be placed on the ability to produce appreciable quantities of the correct product of interest (POI). The ability to screen several transcript stoichiometries could play a large role in ensuring high amounts of the correct POI. Here we illustrate implementation of an SSI expression system with a single site of integration for development and production of a multi‐chain, bi‐specific molecule. A SSI vector with a single copy of all of the genes of interest was initially selected for stable Chinese hamster ovary transfection. While the resulting transfection pools generated low levels of the desired heterodimer, utilizing an intensive clone screen strategy, we were able to identify clones having significantly higher levels of POI. In‐depth genotypic characterization of clones having the desirable phenotype revealed that a duplication of the light chain within the landing pad was responsible for producing the intended molecule. Retrospective transfection pool analysis using a vector configuration mimicking the transgene configuration found in the clones, as well as other vector configurations, yielded more favorable results with respect to % POI. Overall, the study demonstrated that despite the theoretical static nature of the SSI expression system, enough heterogeneity existed to yield clones having significantly different transgene phenotypes/genotypes and support production of a complex multi‐chain molecule.
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Affiliation(s)
- Barbara Tevelev
- Cell Line Development, Biotherapeutics Pharmaceutical Sciences, Pfizer Inc., Andover, Massachusetts, USA
| | - Himakshi Patel
- Analytical Research and Development, Biotherapeutics Pharmaceutical Sciences, Pfizer Inc., Andover, Massachusetts, USA
| | - Kathleen Shields
- Analytical Research and Development, Biotherapeutics Pharmaceutical Sciences, Pfizer Inc., Andover, Massachusetts, USA
| | - Wei Wei
- Cell Line Development, Biotherapeutics Pharmaceutical Sciences, Pfizer Inc., Andover, Massachusetts, USA
| | - Cecilia Cooley
- Cell Line Development, Biotherapeutics Pharmaceutical Sciences, Pfizer Inc., Andover, Massachusetts, USA
| | - Sam Zhang
- Cell Line Development, Biotherapeutics Pharmaceutical Sciences, Pfizer Inc., Andover, Massachusetts, USA
| | | | - Weili Duan
- BioMedicine Design, Pfizer Inc., Andover, Massachusetts, USA
| | - Lam Khetemenee
- BioMedicine Design, Pfizer Inc., Andover, Massachusetts, USA
| | - Ryan Jackobek
- BioMedicine Design, Pfizer Inc., Andover, Massachusetts, USA
| | - Aaron D'Antona
- BioMedicine Design, Pfizer Inc., Andover, Massachusetts, USA
| | - Annette Sievers
- BioMedicine Design, Pfizer Inc., Andover, Massachusetts, USA
| | - Amy King
- BioMedicine Design, Pfizer Inc., Andover, Massachusetts, USA
| | - Amy Tam
- BioMedicine Design, Pfizer Inc., Andover, Massachusetts, USA
| | - Yan Zhang
- BioMedicine Design, Pfizer Inc., Andover, Massachusetts, USA
| | - Eric Sousa
- BioMedicine Design, Pfizer Inc., Andover, Massachusetts, USA
| | - Justin Cohen
- BioMedicine Design, Pfizer Inc., Andover, Massachusetts, USA
| | - Lila Wroblewska
- BioMedicine Design, Pfizer Inc., Andover, Massachusetts, USA
| | - Jeffrey Marshall
- Analytical Research and Development, Biotherapeutics Pharmaceutical Sciences, Pfizer Inc., Andover, Massachusetts, USA
| | - Martha Jackson
- Analytical Research and Development, Biotherapeutics Pharmaceutical Sciences, Pfizer Inc., Andover, Massachusetts, USA
| | - John J Scarcelli
- Cell Line Development, Biotherapeutics Pharmaceutical Sciences, Pfizer Inc., Andover, Massachusetts, USA
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Yadav AK, Rajak KK, Kumar A, Bhatt M, Chakravarti S, Muthu S, Dubal ZB, Khulape S, Yousuf RW, Rai V, Kumar B, Muthuchelvan D, Gupta PK, Singh RP, Singh R. Replication competence of canine distemper virus in cell lines expressing signaling lymphocyte activation molecule (SLAM) of goat, sheep and dog origin. Microb Pathog 2021; 156:104940. [PMID: 33962006 DOI: 10.1016/j.micpath.2021.104940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 04/26/2021] [Accepted: 04/26/2021] [Indexed: 11/30/2022]
Abstract
Cellular receptors play an important role in entry and cell to cell spread of morbillivirus infections. The cells expressing SLAM and Nectin-4 have been used for successful and efficient isolation of canine distemper virus (CDV) in high titre. There are several methods for generation of cells expressing receptor molecules. Here, we have used a comparatively cheaper and easily available method, pcDNA 3.1 (+) for engineering Vero cells to express SLAM gene of goat, sheep and dog origin (Vero/Goat/SLAM (VGS), Vero/Sheep/SLAM (VSS) and Vero/Dog/SLAM (VDS), respectively). The generated cell lines were then compared to test their efficacy to support CDV replication. CDV could be grown in high titre in the cells expressing SLAM and a difference of log two could be recorded in virus titre between VDS and native Vero cells. Also, CDV could be grown in a higher titre in VDS as compared to VGS and VSS. The finding of this study supports the preferential use of SLAM expressing cells over the native Vero cells by CDV. Further, the higher titre of CDV in cells expressing dog-SLAM as compared to the cells expressing SLAM of non-CDV hosts (i.e. goat and sheep) points towards the preferential use of dog SLAM by the CDV and may be a plausible reason for differential susceptibility of small ruminants and Canines to CDV.
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Affiliation(s)
- Ajay Kumar Yadav
- Division of Biological Products, Indian Council of Agricultural Research (ICAR)-Indian Veterinary Research Institute (IVRI), Izatnagar, 243122, Bareilly, Uttar Pradesh, India; ICAR -National Research Centre on Pig, Rani, Guwahati, Assam, 781131, India
| | - Kaushal Kishor Rajak
- Division of Biological Products, Indian Council of Agricultural Research (ICAR)-Indian Veterinary Research Institute (IVRI), Izatnagar, 243122, Bareilly, Uttar Pradesh, India.
| | - Ashok Kumar
- Division of Biological Products, Indian Council of Agricultural Research (ICAR)-Indian Veterinary Research Institute (IVRI), Izatnagar, 243122, Bareilly, Uttar Pradesh, India
| | - Mukesh Bhatt
- Division of Biological Products, Indian Council of Agricultural Research (ICAR)-Indian Veterinary Research Institute (IVRI), Izatnagar, 243122, Bareilly, Uttar Pradesh, India; ICAR -National Organic Farming Research Institute, Tadong, Gangtok, Sikkim, 737102, India
| | - Soumendu Chakravarti
- Division of Biological Products, Indian Council of Agricultural Research (ICAR)-Indian Veterinary Research Institute (IVRI), Izatnagar, 243122, Bareilly, Uttar Pradesh, India
| | - Sankar Muthu
- Division of Parasitology, Indian Council of Agricultural Research (ICAR)-Indian Veterinary Research Institute (IVRI), Izatnagar, 243122, Bareilly, Uttar Pradesh, India
| | - Z B Dubal
- Division of Veterinary Public Health, Indian Council of Agricultural Research (ICAR)-Indian Veterinary Research Institute (IVRI), Izatnagar, 243122, Bareilly, Uttar Pradesh, India
| | - Sagar Khulape
- ICAR-D-FMD, Indian Veterinary Research Institute (IVRI), Mukteswar, 263138, Nainital, Uttarakhand, India
| | - Raja Wasim Yousuf
- Division of Biological Products, Indian Council of Agricultural Research (ICAR)-Indian Veterinary Research Institute (IVRI), Izatnagar, 243122, Bareilly, Uttar Pradesh, India
| | - Vishal Rai
- Division of Biological Products, Indian Council of Agricultural Research (ICAR)-Indian Veterinary Research Institute (IVRI), Izatnagar, 243122, Bareilly, Uttar Pradesh, India
| | - Bablu Kumar
- Division of Biological Products, Indian Council of Agricultural Research (ICAR)-Indian Veterinary Research Institute (IVRI), Izatnagar, 243122, Bareilly, Uttar Pradesh, India
| | - Dhanavelu Muthuchelvan
- Division of Virology, Indian Council of Agricultural Research (ICAR)-Indian Veterinary Research Institute (IVRI), Mukteswar, 263138, Nainital, Uttrakhand, India
| | - Praveen Kumar Gupta
- Division of Animal Biotechnology, Indian Council of Agricultural Research (ICAR)-Indian Veterinary Research Institute (IVRI), Izatnagar, 243122, Bareilly, Uttar Pradesh, India
| | - Rabindra Prasad Singh
- Division of Biological Products, Indian Council of Agricultural Research (ICAR)-Indian Veterinary Research Institute (IVRI), Izatnagar, 243122, Bareilly, Uttar Pradesh, India
| | - Rajkumar Singh
- Indian Council of Agricultural Research (ICAR)-Indian Veterinary Research Institute (IVRI), Izatnagar, 243122, Bareilly, Uttar Pradesh, India.
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Gödecke N, Herrmann S, Hauser H, Mayer-Bartschmid A, Trautwein M, Wirth D. Rational Design of Single Copy Expression Cassettes in Defined Chromosomal Sites Overcomes Intraclonal Cell-to-Cell Expression Heterogeneity and Ensures Robust Antibody Production. ACS Synth Biol 2021; 10:145-157. [PMID: 33382574 DOI: 10.1021/acssynbio.0c00519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The expression of endogenous genes as well as transgenes depends on regulatory elements within and surrounding genes as well as their epigenetic modifications. Members of a cloned cell population often show pronounced cell-to-cell heterogeneity with respect to the expression of a certain gene. To investigate the heterogeneity of recombinant protein expression we targeted cassettes into two preselected chromosomal hot-spots in Chinese hamster ovary (CHO) cells. Depending on the gene of interest and the design of the expression cassette, we found strong expression variability that could be reduced by epigenetic modifiers, but not by site-specific recruitment of the modulator dCas9-VPR. In particular, the implementation of ubiquitous chromatin opening elements (UCOEs) reduced cell-to-cell heterogeneity and concomitantly increased expression. The application of this method to recombinant antibody expression confirmed that rational design of cell lines for production of transgenes with predictable and high titers is a promising approach.
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Affiliation(s)
- Natascha Gödecke
- RG Model Systems for Infection and Immunity, Helmholtz Centre for Infection Research, Braunschweig 38124, Germany
| | - Sabrina Herrmann
- RG Model Systems for Infection and Immunity, Helmholtz Centre for Infection Research, Braunschweig 38124, Germany
| | - Hansjörg Hauser
- Staff Unit Scientific Strategy, Helmholtz Centre for Infection Research, Braunschweig 38124, Germany
| | | | | | - Dagmar Wirth
- RG Model Systems for Infection and Immunity, Helmholtz Centre for Infection Research, Braunschweig 38124, Germany
- Institute of Experimental Hematology, Medical University Hannover, Hannover 30625, Germany
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36
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Elias A, Kassis H, Elkader SA, Gritsenko N, Nahmad A, Shir H, Younis L, Shannan A, Aihara H, Prag G, Yagil E, Kolot M. HK022 bacteriophage Integrase mediated RMCE as a potential tool for human gene therapy. Nucleic Acids Res 2020; 48:12804-12816. [PMID: 33270859 PMCID: PMC7736782 DOI: 10.1093/nar/gkaa1140] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 10/31/2020] [Accepted: 11/08/2020] [Indexed: 12/25/2022] Open
Abstract
HK022 coliphage site-specific recombinase Integrase (Int) can catalyze integrative site-specific recombination and recombinase-mediated cassette exchange (RMCE) reactions in mammalian cell cultures. Owing to the promiscuity of the 7 bp overlap sequence in its att sites, active ‘attB’ sites flanking human deleterious mutations were previously identified that may serve as substrates for RMCE reactions for future potential gene therapy. However, the wild type Int proved inefficient in catalyzing such RMCE reactions. To address this low efficiency, variants of Int were constructed and examined by integrative site-specific recombination and RMCE assays in human cells using native ‘attB’ sites. As a proof of concept, various Int derivatives have demonstrated successful RMCE reactions using a pair of native ‘attB’ sites that were inserted as a substrate into the human genome. Moreover, successful RMCE reactions were demonstrated in native locations of the human CTNS and DMD genes whose mutations are responsible for Cystinosis and Duchene Muscular Dystrophy diseases, respectively. This work provides a steppingstone for potential downstream therapeutic applications.
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Affiliation(s)
- Amer Elias
- Department of Biochemistry and Molecular Biology, School of Neurobiology, Biochemistry &Biophysics, Tel-Aviv University, Tel-Aviv, Israel
| | - Hala Kassis
- Department of Biochemistry and Molecular Biology, School of Neurobiology, Biochemistry &Biophysics, Tel-Aviv University, Tel-Aviv, Israel
| | - Suha Abd Elkader
- Department of Biochemistry and Molecular Biology, School of Neurobiology, Biochemistry &Biophysics, Tel-Aviv University, Tel-Aviv, Israel
| | - Natasha Gritsenko
- Department of Biochemistry and Molecular Biology, School of Neurobiology, Biochemistry &Biophysics, Tel-Aviv University, Tel-Aviv, Israel
| | - Alessio Nahmad
- Department of Biochemistry and Molecular Biology, School of Neurobiology, Biochemistry &Biophysics, Tel-Aviv University, Tel-Aviv, Israel
| | - Hodaya Shir
- Department of Biochemistry and Molecular Biology, School of Neurobiology, Biochemistry &Biophysics, Tel-Aviv University, Tel-Aviv, Israel
| | - Liana Younis
- Department of Biochemistry and Molecular Biology, School of Neurobiology, Biochemistry &Biophysics, Tel-Aviv University, Tel-Aviv, Israel
| | - Atheer Shannan
- Department of Biochemistry and Molecular Biology, School of Neurobiology, Biochemistry &Biophysics, Tel-Aviv University, Tel-Aviv, Israel
| | - Hideki Aihara
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota TwinCities, Minneapolis, MN, 55455, USA
| | - Gali Prag
- Department of Biochemistry and Molecular Biology, School of Neurobiology, Biochemistry &Biophysics, Tel-Aviv University, Tel-Aviv, Israel
| | - Ezra Yagil
- Department of Biochemistry and Molecular Biology, School of Neurobiology, Biochemistry &Biophysics, Tel-Aviv University, Tel-Aviv, Israel
| | - Mikhail Kolot
- Department of Biochemistry and Molecular Biology, School of Neurobiology, Biochemistry &Biophysics, Tel-Aviv University, Tel-Aviv, Israel
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McGraw CE, Peng D, Sandoval NR. Synthetic biology approaches: the next tools for improved protein production from CHO cells. Curr Opin Chem Eng 2020. [DOI: 10.1016/j.coche.2020.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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38
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Li J, Li Y, Pawlik KM, Napierala JS, Napierala M. A CRISPR-Cas9, Cre- lox, and Flp- FRT Cascade Strategy for the Precise and Efficient Integration of Exogenous DNA into Cellular Genomes. CRISPR J 2020; 3:470-486. [PMID: 33146562 DOI: 10.1089/crispr.2020.0042] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
We describe a protocol for the precise integration of exogenous DNA into user-defined genomic loci in cultured cells. This strategy first introduces a promoter and a lox site to a specific location via a Cas9-induced double-strand break. Second, a gene of interest (GOI) is inserted into the lox site via Cre-lox recombination. Upon correct insertion, a cis-linked antibiotic resistance gene will be expressed from a promoter introduced into the genome in the first step assuring selection for correct integrants. Last, the selection cassette is excised via a Flp-FRT recombination event, leaving a precisely targeted GOI. This method is broadly applicable to any exogenous DNA to be integrated, choice of integration site, and choice of cell type. The most remarkable aspect of this versatile approach, termed "CasPi" (cascaded precise integration), is that it allows for precise genome targeting with large, frequently complex, and repetitive DNA sequences that do not integrate efficiently or at all with current genome targeting methods.
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Affiliation(s)
- Jixue Li
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Yanjie Li
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Kevin M Pawlik
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Jill S Napierala
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Marek Napierala
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA
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39
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Sergeeva D, Lee GM, Nielsen LK, Grav LM. Multicopy Targeted Integration for Accelerated Development of High-Producing Chinese Hamster Ovary Cells. ACS Synth Biol 2020; 9:2546-2561. [PMID: 32835482 DOI: 10.1021/acssynbio.0c00322] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The ever-growing biopharmaceutical industry relies on the production of recombinant therapeutic proteins in Chinese hamster ovary (CHO) cells. The traditional timelines of CHO cell line development can be significantly shortened by the use of targeted gene integration (TI). However, broad use of TI has been limited due to the low specific productivity (qP) of TI-generated clones. Here, we show a 10-fold increase in the qP of therapeutic glycoproteins in CHO cells through the development and optimization of a multicopy TI method. We used a recombinase-mediated cassette exchange (RMCE) platform to investigate the effect of gene copy number, 5' and 3' gene regulatory elements, and landing pad features on qP. We evaluated the limitations of multicopy expression from a single genomic site as well as multiple genomic sites and found that a transcriptional bottleneck can appear with an increase in gene dosage. We created a dual-RMCE system for simultaneous multicopy TI in two genomic sites and generated isogenic high-producing clones with qP of 12-14 pg/cell/day and product titer close to 1 g/L in fed-batch. Our study provides an extensive characterization of the multicopy TI method and elucidates the relationship between gene copy number and protein expression in mammalian cells. Moreover, it demonstrates that TI-generated CHO cells are capable of producing therapeutic proteins at levels that can support their industrial manufacture.
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Affiliation(s)
- Daria Sergeeva
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby 2800, Denmark
| | - Gyun Min Lee
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby 2800, Denmark
- Department of Biological Sciences, KAIST, Daejeon 34141, Republic of Korea
| | - Lars Keld Nielsen
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby 2800, Denmark
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, Brisbane 4072, Australia
| | - Lise Marie Grav
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby 2800, Denmark
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40
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Efficient allele conversion in mouse zygotes and primary cells based on electroporation of Cre protein. Methods 2020; 191:87-94. [PMID: 32717290 DOI: 10.1016/j.ymeth.2020.07.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 06/23/2020] [Accepted: 07/16/2020] [Indexed: 11/22/2022] Open
Abstract
Cre-loxP recombination system is a powerful tool for genome engineering. One of its applications is found in genetic mouse models that often require to induce Cre recombination in preimplantation embryos. Here, we describe a technically simple, affordable and highly efficient protocol for Cre protein delivery into mouse zygotes by electroporation. We show that electroporation based delivery of Cre has no negative impact on embryo survival and the method can be easily combined with in vitro fertilization resulting in a significantly faster generation of desired models. Lastly, we demonstrate that Cre protein electroporation is suitable for allelic conversion in primary cells derived from conditional mouse models.
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41
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Efficient Transgenesis in Caenorhabditis elegans Using Flp Recombinase-Mediated Cassette Exchange. Genetics 2020; 215:903-921. [PMID: 32513816 DOI: 10.1534/genetics.120.303388] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 05/01/2020] [Indexed: 11/18/2022] Open
Abstract
The application of CRISPR technology has greatly facilitated the creation of transgenic Caenorhabditis elegans lines. However, methods to insert multi-kilobase DNA constructs remain laborious even with these advances. Here, I describe a new approach for introducing large DNA constructs into the C. elegans genome at specific sites using a combination of Flp and Cre recombinases. The system utilizes specialized integrated landing sites that express GFP ubiquitously flanked by single loxP, FRT, and FRT3 sites. DNA sequences of interest are inserted into an integration vector that contains a sqt-1 self-excising cassette and FRT and FRT3 sites. Plasmid DNA is injected into the germline of landing site animals. Transgenic animals are identified as Rol progeny, and the sqt-1 marker is subsequently excised with heat shock Cre expression. Integration events were obtained at a rate of approximately one integration per three injected F0 animals-a rate substantially higher than any current approach. To demonstrate the robustness of the approach, I compared the efficiency of the Gal4/UAS, QF (and QF2)/QUAS, tetR(and rtetR)/tetO, and LexA/lexO bipartite expression systems by assessing expression levels in combinations of driver and reporter GFP constructs and a direct promoter GFP fusion each integrated at multiple sites in the genome. My data demonstrate that all four bipartite systems are functional in C. elegans Although the new integration system has several limitations, it greatly reduces the effort required to create single-copy insertions at defined sites in the C. elegans genome.
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42
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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.
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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
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43
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Srirangan K, Loignon M, Durocher Y. The use of site-specific recombination and cassette exchange technologies for monoclonal antibody production in Chinese Hamster ovary cells: retrospective analysis and future directions. Crit Rev Biotechnol 2020; 40:833-851. [DOI: 10.1080/07388551.2020.1768043] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Kajan Srirangan
- Mammalian Cell Expression, Human Health Therapeutics Research Centre, National Research Council Canada, Montréal, Québec, Canada
| | - Martin Loignon
- Mammalian Cell Expression, Human Health Therapeutics Research Centre, National Research Council Canada, Montréal, Québec, Canada
| | - Yves Durocher
- Mammalian Cell Expression, Human Health Therapeutics Research Centre, National Research Council Canada, Montréal, Québec, Canada
- Département de biochimie et médecine moléculaire, Université de Montréal, Montréal, Québec, Canada
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44
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Lansing F, Paszkowski-Rogacz M, Schmitt LT, Schneider PM, Rojo Romanos T, Sonntag J, Buchholz F. A heterodimer of evolved designer-recombinases precisely excises a human genomic DNA locus. Nucleic Acids Res 2020; 48:472-485. [PMID: 31745551 PMCID: PMC7107906 DOI: 10.1093/nar/gkz1078] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 10/29/2019] [Accepted: 11/04/2019] [Indexed: 01/04/2023] Open
Abstract
Site-specific recombinases (SSRs) such as the Cre/loxP system are useful genome engineering tools that can be repurposed by altering their DNA-binding specificity. However, SSRs that delete a natural sequence from the human genome have not been reported thus far. Here, we describe the generation of an SSR system that precisely excises a 1.4 kb fragment from the human genome. Through a streamlined process of substrate-linked directed evolution we generated two separate recombinases that, when expressed together, act as a heterodimer to delete a human genomic sequence from chromosome 7. Our data indicates that designer-recombinases can be generated in a manageable timeframe for precision genome editing. A large-scale bioinformatics analysis suggests that around 13% of all human protein-coding genes could be targetable by dual designer-recombinase induced genomic deletion (dDRiGD). We propose that heterospecific designer-recombinases, which work independently of the host DNA repair machinery, represent an efficient and safe alternative to nuclease-based genome editing technologies.
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Affiliation(s)
- Felix Lansing
- Medical Faculty and University Hospital Carl Gustav Carus, UCC Section Medical Systems Biology, TU Dresden, 01307 Dresden, Germany
| | - Maciej Paszkowski-Rogacz
- Medical Faculty and University Hospital Carl Gustav Carus, UCC Section Medical Systems Biology, TU Dresden, 01307 Dresden, Germany
| | - Lukas Theo Schmitt
- Medical Faculty and University Hospital Carl Gustav Carus, UCC Section Medical Systems Biology, TU Dresden, 01307 Dresden, Germany
| | - Paul Martin Schneider
- Medical Faculty and University Hospital Carl Gustav Carus, UCC Section Medical Systems Biology, TU Dresden, 01307 Dresden, Germany
| | - Teresa Rojo Romanos
- Medical Faculty and University Hospital Carl Gustav Carus, UCC Section Medical Systems Biology, TU Dresden, 01307 Dresden, Germany
| | - Jan Sonntag
- Medical Faculty and University Hospital Carl Gustav Carus, UCC Section Medical Systems Biology, TU Dresden, 01307 Dresden, Germany
| | - Frank Buchholz
- Medical Faculty and University Hospital Carl Gustav Carus, UCC Section Medical Systems Biology, TU Dresden, 01307 Dresden, Germany
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45
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Brumos J, Zhao C, Gong Y, Soriano D, Patel AP, Perez-Amador MA, Stepanova AN, Alonso JM. An Improved Recombineering Toolset for Plants. THE PLANT CELL 2020; 32:100-122. [PMID: 31666295 PMCID: PMC6961616 DOI: 10.1105/tpc.19.00431] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 10/07/2019] [Accepted: 10/29/2019] [Indexed: 05/08/2023]
Abstract
Gene functional studies often rely on the expression of a gene of interest as transcriptional and translational fusions with specialized tags. Ideally, this is done in the native chromosomal contexts to avoid potential misexpression artifacts. Although recent improvements in genome editing have made it possible to directly modify the target genes in their native chromosomal locations, classical transgenesis is still the preferred experimental approach chosen in most gene tagging studies because of its time efficiency and accessibility. We have developed a recombineering-based tagging system that brings together the convenience of the classical transgenic approaches and the high degree of confidence in the results obtained by direct chromosomal tagging using genome-editing strategies. These simple, scalable, customizable recombineering toolsets and protocols allow a variety of genetic modifications to be generated. In addition, we developed a highly efficient recombinase-mediated cassette exchange system to facilitate the transfer of the desired sequences from a bacterial artificial chromosome clone to a transformation-compatible binary vector, expanding the use of the recombineering approaches beyond Arabidopsis (Arabidopsis thaliana). We demonstrated the utility of this system by generating more than 250 whole-gene translational fusions and 123 Arabidopsis transgenic lines corresponding to 62 auxin-related genes and characterizing the translational reporter expression patterns for 14 auxin biosynthesis genes.
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Affiliation(s)
- Javier Brumos
- Department of Plant and Microbial Biology, Program in Genetics, North Carolina State University, Raleigh, North Carolina 27695
| | - Chengsong Zhao
- Department of Plant and Microbial Biology, Program in Genetics, North Carolina State University, Raleigh, North Carolina 27695
| | - Yan Gong
- Department of Plant and Microbial Biology, Program in Genetics, North Carolina State University, Raleigh, North Carolina 27695
- Department of Biology, Stanford University, Stanford, California 94305
| | - David Soriano
- Department of Plant and Microbial Biology, Program in Genetics, North Carolina State University, Raleigh, North Carolina 27695
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708
| | - Arjun P Patel
- Department of Plant and Microbial Biology, Program in Genetics, North Carolina State University, Raleigh, North Carolina 27695
| | - Miguel A Perez-Amador
- Department of Plant and Microbial Biology, Program in Genetics, North Carolina State University, Raleigh, North Carolina 27695
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universidad Politécnica de Valencia (UPV)-Consejo Superior de Investigaciones Científicas (CSIC), 46022 Valencia, Spain
| | - Anna N Stepanova
- Department of Plant and Microbial Biology, Program in Genetics, North Carolina State University, Raleigh, North Carolina 27695
| | - Jose M Alonso
- Department of Plant and Microbial Biology, Program in Genetics, North Carolina State University, Raleigh, North Carolina 27695
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46
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Protein trap: a new Swiss army knife for geneticists? Mol Biol Rep 2019; 47:1445-1458. [PMID: 31728729 DOI: 10.1007/s11033-019-05181-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 11/04/2019] [Indexed: 10/25/2022]
Abstract
The protein trap is a powerful tool for genetic and biochemical studies of gene function in the animal kingdom. Although the original protein trap was developed for flies, it can be easily adapted to other multicellular organisms, both known models and ones with an unsequenced genome. The protein trap has been successfully applied to the fruit fly, crustaceans Parhyale hawaiensis, zebrafish, and insect and animal cell cultures. This approach is based on the integration into genes of an artificial exon that carries DNA encoding a fluorescent marker, standardized immunoepitopes, an integrase docking site, and splice acceptor and donor sites. The protein trap for cell cultures additionally contains an antibiotic resistance gene, which facilitates the selection of trapped clones. Resulting chimeric tagged mRNAs can be interfered by dsRNA against GFP (iGFPi-in vivo GFP interference), or the chimeric proteins can be efficiently knocked down by deGradFP technology. Both RNA and protein knockdowns produce a strong loss of function phenotype in tagged cells. The fluorescent and protein affinity tags can be used for tagged protein localisation within the cell and for identifying their binding partners in their native complexes. Insertion into protein trap integrase docking sites allows the replacement of trap contents by any new constructs, including other markers, cell toxins, stop-codons, and binary expression systems such as GAL4/UAS, LexA/LexAop and QF/QUAS, that reliably reflect endogenous gene expression. A distinctive feature of the protein trap approach is that all manipulations with a gene or its product occur only in the endogenous locus, which cannot be achieved by any other method.
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47
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Gaidukov L, Wroblewska L, Teague B, Nelson T, Zhang X, Liu Y, Jagtap K, Mamo S, Tseng WA, Lowe A, Das J, Bandara K, Baijuraj S, Summers NM, Lu TK, Zhang L, Weiss R. A multi-landing pad DNA integration platform for mammalian cell engineering. Nucleic Acids Res 2019; 46:4072-4086. [PMID: 29617873 PMCID: PMC5934685 DOI: 10.1093/nar/gky216] [Citation(s) in RCA: 101] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 03/14/2018] [Indexed: 12/11/2022] Open
Abstract
Engineering mammalian cell lines that stably express many transgenes requires the precise insertion of large amounts of heterologous DNA into well-characterized genomic loci, but current methods are limited. To facilitate reliable large-scale engineering of CHO cells, we identified 21 novel genomic sites that supported stable long-term expression of transgenes, and then constructed cell lines containing one, two or three 'landing pad' recombination sites at selected loci. By using a highly efficient BxB1 recombinase along with different selection markers at each site, we directed recombinase-mediated insertion of heterologous DNA to selected sites, including targeting all three with a single transfection. We used this method to controllably integrate up to nine copies of a monoclonal antibody, representing about 100 kb of heterologous DNA in 21 transcriptional units. Because the integration was targeted to pre-validated loci, recombinant protein expression remained stable for weeks and additional copies of the antibody cassette in the integrated payload resulted in a linear increase in antibody expression. Overall, this multi-copy site-specific integration platform allows for controllable and reproducible insertion of large amounts of DNA into stable genomic sites, which has broad applications for mammalian synthetic biology, recombinant protein production and biomanufacturing.
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Affiliation(s)
- Leonid Gaidukov
- Synthetic Biology Center, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | - Brian Teague
- Synthetic Biology Center, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Tom Nelson
- Cell Line Development, Biotherapeutics Pharmaceutical Science, Pfizer Inc, Andover, MA 01810, USA
| | - Xin Zhang
- Biomedicine Design, Pfizer Inc, Cambridge, MA 02139, USA
| | - Yan Liu
- Biomedicine Design, Pfizer Inc, Cambridge, MA 02139, USA
| | - Kalpana Jagtap
- Synthetic Biology Center, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Selamawit Mamo
- Synthetic Biology Center, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Wen Allen Tseng
- Synthetic Biology Center, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Alexis Lowe
- Biomedicine Design, Pfizer Inc, Cambridge, MA 02139, USA
| | - Jishnu Das
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Ragon Institute of MGH, MIT & Harvard, Cambridge, MA 02139, USA
| | - Kalpanie Bandara
- Cell Line Development, Biotherapeutics Pharmaceutical Science, Pfizer Inc, Andover, MA 01810, USA
| | - Swetha Baijuraj
- Cell Line Development, Biotherapeutics Pharmaceutical Science, Pfizer Inc, Andover, MA 01810, USA
| | - Nevin M Summers
- Synthetic Biology Center, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Timothy K Lu
- Synthetic Biology Center, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Lin Zhang
- Cell Line Development, Biotherapeutics Pharmaceutical Science, Pfizer Inc, Andover, MA 01810, USA
| | - Ron Weiss
- Synthetic Biology Center, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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48
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Anand A, Wu E, Li Z, TeRonde S, Arling M, Lenderts B, Mutti JS, Gordon‐Kamm W, Jones TJ, Chilcoat ND. High efficiency Agrobacterium-mediated site-specific gene integration in maize utilizing the FLP-FRT recombination system. PLANT BIOTECHNOLOGY JOURNAL 2019; 17:1636-1645. [PMID: 30706638 PMCID: PMC6662307 DOI: 10.1111/pbi.13089] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 01/23/2019] [Accepted: 01/27/2019] [Indexed: 05/20/2023]
Abstract
An efficient Agrobacterium-mediated site-specific integration (SSI) technology using the flipase/flipase recognition target (FLP/FRT) system in elite maize inbred lines is described. The system allows precise integration of a single copy of a donor DNA flanked by heterologous FRT sites into a predefined recombinant target line (RTL) containing the corresponding heterologous FRT sites. A promoter-trap system consisting of a pre-integrated promoter followed by an FRT site enables efficient selection of events. The efficiency of this system is dependent on several factors including Agrobacterium tumefaciens strain, expression of morphogenic genes Babyboom (Bbm) and Wuschel2 (Wus2) and choice of heterologous FRT pairs. Of the Agrobacterium strains tested, strain AGL1 resulted in higher transformation frequency than strain LBA4404 THY- (0.27% vs. 0.05%; per cent of infected embryos producing events). The addition of morphogenic genes increased transformation frequency (2.65% in AGL1; 0.65% in LBA4404 THY-). Following further optimization, including the choice of FRT pairs, a method was developed that achieved 19%-22.5% transformation frequency. Importantly, >50% of T0 transformants contain the desired full-length site-specific insertion. The frequencies reported here establish a new benchmark for generating targeted quality events compatible with commercial product development.
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Affiliation(s)
- Ajith Anand
- Agricultural Division of Dow DuPontCorteva Agriscience™JohnstonIAUSA
| | - Emily Wu
- Agricultural Division of Dow DuPontCorteva Agriscience™JohnstonIAUSA
| | - Zhi Li
- Agricultural Division of Dow DuPontCorteva Agriscience™JohnstonIAUSA
| | - Sue TeRonde
- Agricultural Division of Dow DuPontCorteva Agriscience™JohnstonIAUSA
| | - Maren Arling
- Agricultural Division of Dow DuPontCorteva Agriscience™JohnstonIAUSA
| | - Brian Lenderts
- Agricultural Division of Dow DuPontCorteva Agriscience™JohnstonIAUSA
| | - Jasdeep S. Mutti
- Agricultural Division of Dow DuPontCorteva Agriscience™JohnstonIAUSA
| | | | - Todd J. Jones
- Agricultural Division of Dow DuPontCorteva Agriscience™JohnstonIAUSA
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49
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Chi X, Zheng Q, Jiang R, Chen-Tsai RY, Kong LJ. A system for site-specific integration of transgenes in mammalian cells. PLoS One 2019; 14:e0219842. [PMID: 31344144 PMCID: PMC6657834 DOI: 10.1371/journal.pone.0219842] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 07/02/2019] [Indexed: 11/19/2022] Open
Abstract
Mammalian cell expression systems are the most commonly used platforms for producing biotherapeutic proteins. However, development of recombinant mammalian cell lines is often hindered by the unstable and variable transgene expression associated with random integration. We have developed an efficient strategy for site-specific integration of genes of interest (GOIs). This method enables rapid and precise insertion of a gene expression cassette at defined loci in mammalian cells, resulting in homogeneous transgene expression. We identified the Hipp11 (H11) gene as a "safe harbor" locus for gene knock-in in CHO-S cells. Using clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 mediated homologous recombination, we knocked in a DNA cassette (the landing pad) that includes a pair of PhiC31 bacteriophage attP sites and genes facilitating integrase-based GOI integration. A master cell line, with the landing pad inserted correctly in the H11 locus, was established. This master cell line was used for site-specific, irreversible recombination, catalyzed by PhiC31 integrase. Using this system, an integration efficiency of 97.7% was achieved with green fluorescent protein (GFP) after selection. The system was then further validated in HEK293T cells, using an analogous protocol to insert the GFP gene at the ROSA26 locus, resulting in 90.7% GFP-positive cells after selection. In comparison, random insertion yielded 0.68% and 1.32% GFP-positive cells in the CHO-S and HEK293T cells, respectively. Taken together, these findings demonstrated an accurate and effective protocol for generating recombinant cell lines to provide consistent protein production. Its likely broad applicability was illustrated here in two cell lines, CHO-S and HEK293T, using two different genomic loci as integration sites. Thus, the system is potentially valuable for biomanufacturing therapeutic proteins.
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Affiliation(s)
- Xiuling Chi
- Applied StemCell, Inc., Milpitas, California, United States of America
| | - Qi Zheng
- Applied StemCell, Inc., Milpitas, California, United States of America
| | - Ruhong Jiang
- Applied StemCell, Inc., Milpitas, California, United States of America
| | - Ruby Yanru Chen-Tsai
- Applied StemCell, Inc., Milpitas, California, United States of America
- * E-mail: (RT); (LK)
| | - Ling-Jie Kong
- Applied StemCell, Inc., Milpitas, California, United States of America
- * E-mail: (RT); (LK)
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Zhu J, Hatton D. New Mammalian Expression Systems. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2019; 165:9-50. [PMID: 28585079 DOI: 10.1007/10_2016_55] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
There are an increasing number of recombinant antibodies and proteins in preclinical and clinical development for therapeutic applications. Mammalian expression systems are key to enabling the production of these molecules, and Chinese hamster ovary (CHO) cell platforms continue to be central to delivery of the stable cell lines required for large-scale production. Increasing pressure on timelines and efficiency, further innovation of molecular formats and the shift to new production systems are driving developments of these CHO cell line platforms. The availability of genome and transcriptome data coupled with advancing gene editing tools are increasing the ability to design and engineer CHO cell lines to meet these challenges. This chapter aims to give an overview of the developments in CHO expression systems and some of the associated technologies over the past few years.
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Affiliation(s)
- Jie Zhu
- MedImmune, One MedImmune Way, Gaithersburg, MD, 20878, USA
| | - Diane Hatton
- MedImmune, Milstein Building, Granta Park, Cambridge, CB21 6GH, UK.
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