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Yang C, Yang Y, Chu G, Wang R, Li H, Mao Y, Wang M, Zhang J, Liao X, Ma H. AutoESDCas: A Web-Based Tool for the Whole-Workflow Editing Sequence Design for Microbial Genome Editing Based on the CRISPR/Cas System. ACS Synth Biol 2024; 13:1737-1749. [PMID: 38845097 DOI: 10.1021/acssynbio.4c00063] [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: 06/22/2024]
Abstract
Genome editing is the basis for the modification of engineered microbes. In the process of genome editing, the design of editing sequences, such as primers and sgRNA, is very important for the accurate positioning of editing sites and efficient sequence editing. The whole process of genome editing involves multiple rounds and types of editing sequence design, while the development of related whole-workflow design tools for high-throughput experimental requirements lags. Here, we propose AutoESDCas, an online tool for the end-to-end editing sequence design for microbial genome editing based on the CRISPR/Cas system. This tool facilitates all types of genetic manipulation covering diverse experimental requirements and design scenarios, enables biologists to quickly and efficiently obtain all editing sequences needed for the entire genome editing process, and empowers high-throughput strain modification. Notably, with its off-target risk assessment function for editing sequences, the usability of the design results is significantly improved. AutoESDCas is freely available at https://autoesdcas.biodesign.ac.cn/with the source code at https://github.com/tibbdc/AutoESDCas/.
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Affiliation(s)
- Chunhe Yang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
- Biodesign Center, Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Yi Yang
- Biodesign Center, Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Guangyun Chu
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- College of Food Science and Engineering, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Ruoyu Wang
- Biodesign Center, Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Haoran Li
- Biodesign Center, Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Yufeng Mao
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Meng Wang
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Jian Zhang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Xiaoping Liao
- Haihe Laboratory of Synthetic Biology, 300308 Tianjin, China
- Biodesign Center, Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Hongwu Ma
- Biodesign Center, Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
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2
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Miles LB, Calcinotto V, Oveissi S, Serrano RJ, Sonntag C, Mulia O, Lee C, Bryson-Richardson RJ. CRIMP: a CRISPR/Cas9 insertional mutagenesis protocol and toolkit. Nat Commun 2024; 15:5011. [PMID: 38866742 PMCID: PMC11169554 DOI: 10.1038/s41467-024-49341-7] [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: 08/23/2023] [Accepted: 05/31/2024] [Indexed: 06/14/2024] Open
Abstract
Site-directed insertion is a powerful approach for generating mutant alleles, but low efficiency and the need for customisation for each target has limited its application. To overcome this, we developed a highly efficient targeted insertional mutagenesis system, CRIMP, and an associated plasmid toolkit, CRIMPkit, that disrupts native gene expression by inducing complete transcriptional termination, generating null mutant alleles without inducing genetic compensation. The protocol results in a high frequency of integration events and can generate very early targeted insertions, during the first cell division, producing embryos with expression in one or both halves of the body plan. Fluorescent readout of integration events facilitates selection of successfully mutagenized fish and, subsequently, visual identification of heterozygous and mutant animals. Together, these advances greatly improve the efficacy of generating and studying mutant lines. The CRIMPkit contains 24 ready-to-use plasmid vectors to allow easy and complete mutagenesis of any gene in any reading frame without requiring custom sequences, modification, or subcloning.
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Affiliation(s)
- Lee B Miles
- School of Biological Sciences, Monash University, Clayton, Melbourne, VIC, 3800, Australia
| | - Vanessa Calcinotto
- School of Biological Sciences, Monash University, Clayton, Melbourne, VIC, 3800, Australia
| | - Sara Oveissi
- School of Biological Sciences, Monash University, Clayton, Melbourne, VIC, 3800, Australia
| | - Rita J Serrano
- School of Biological Sciences, Monash University, Clayton, Melbourne, VIC, 3800, Australia
| | - Carmen Sonntag
- School of Biological Sciences, Monash University, Clayton, Melbourne, VIC, 3800, Australia
| | - Orlen Mulia
- School of Biological Sciences, Monash University, Clayton, Melbourne, VIC, 3800, Australia
| | - Clara Lee
- School of Biological Sciences, Monash University, Clayton, Melbourne, VIC, 3800, Australia
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3
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Guo L, Yang G. Pioneering DNA assembling techniques and their applications in eukaryotic microalgae. Biotechnol Adv 2024; 70:108301. [PMID: 38101551 DOI: 10.1016/j.biotechadv.2023.108301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 11/12/2023] [Accepted: 12/08/2023] [Indexed: 12/17/2023]
Abstract
Assembling DNA fragments is a fundamental manipulation of cloning microalgal genes and carrying out microalgal synthetic biological studies. From the earliest DNA recombination to current trait and metabolic pathway engineering, we are always accompanied by homology-based DNA assembling. The improvement and modification of pioneering DNA assembling techniques and the combinational applications of the available assembling techniques have diversified and complicated the literature environment and aggravated our identification of the core and pioneering methodologies. Identifying the core assembling methodologies and using them appropriately and flourishing them even are important for researchers. A group of microalgae have been evolving as the models for both industrial applications and biological studies. DNA assembling requires researchers to know the methods available and their improvements and evolvements. In this review, we summarized the pioneering (core; leading) DNA assembling techniques developed previously, extended these techniques to their modifications, improvements and their combinations, and highlighted their applications in eukaryotic microalgae. We predicted that the gene(s) will be assembled into a functional cluster (e.g., those involving in a metabolic pathway, and stacked on normal microalgal chromosomes, their artificial episomes and looming artificial chromosomes. It should be particularly pointed out that the techniques mentioned in this review are classified according to the strategy used to assemble the final construct.
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Affiliation(s)
- Li Guo
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, PR China
| | - Guanpin Yang
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, PR China; Institutes of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, PR China; MoE Laboratory of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, PR China; Key Laboratory of Marine Genetics and Breeding of Ministry of Education, Ocean University of China, Qingdao 266003, China.
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4
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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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5
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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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6
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Marken JP, Murray RM. Addressable and adaptable intercellular communication via DNA messaging. Nat Commun 2023; 14:2358. [PMID: 37095088 PMCID: PMC10126159 DOI: 10.1038/s41467-023-37788-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Accepted: 03/31/2023] [Indexed: 04/26/2023] Open
Abstract
Engineered consortia are a major research focus for synthetic biologists because they can implement sophisticated behaviors inaccessible to single-strain systems. However, this functional capacity is constrained by their constituent strains' ability to engage in complex communication. DNA messaging, by enabling information-rich channel-decoupled communication, is a promising candidate architecture for implementing complex communication. But its major advantage, its messages' dynamic mutability, is still unexplored. We develop a framework for addressable and adaptable DNA messaging that leverages all three of these advantages and implement it using plasmid conjugation in E. coli. Our system can bias the transfer of messages to targeted receiver strains by 100- to 1000-fold, and their recipient lists can be dynamically updated in situ to control the flow of information through the population. This work lays the foundation for future developments that further utilize the unique advantages of DNA messaging to engineer previously-inaccessible levels of complexity into biological systems.
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Affiliation(s)
- John P Marken
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.
| | - Richard M Murray
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
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7
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Picoli CC, Martins PR, Wong XLC, Righi T, Guimarães PPG, Pinto MCX, Amorim JH, Azevedo VAC, Pereira SR, Kanashiro A, Cruz FC, Resende RR, Mintz A, Frenette PS, Birbrair A. Whole bone subcutaneous transplantation as a strategy to study precisely the bone marrow niche. Stem Cell Rev Rep 2022; 19:906-927. [PMID: 36585572 DOI: 10.1007/s12015-022-10496-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/15/2022] [Indexed: 01/01/2023]
Abstract
Hematopoietic stem cells are maintained in a specialized microenvironment, known as the 'niche', within the bone marrow. Understanding the contribution of cellular and molecular components within the bone marrow niche for the maintenance of hematopoietic stem cells is crucial for the success of therapeutic applications. So far, the roles of crucial mechanisms within the bone marrow niche have been explored in transgenic animals in which genetic modifications are ubiquitously introduced in the whole body. The lack of precise tools to explore genetic alterations exclusively within the bone marrow prevents our determination of whether the observed outcomes result from confounding effects from other organs. Here, we developed a new method - 'whole bone subcutaneous transplantation'- to study the bone marrow niche in transgenic animals precisely. Using immunolabeling of CD45.1 (donor) vs. CD45.2 (recipient) hematopoeitic stem cells, we demonstrated that hematopoeitic stem cells from the host animals colonize the subcutaneously transplanted femurs after transplantation, while the hematopoietic stem cells from the donor disappear. Strikinlgy, the bone marrow niche of these subcutaneously transplanted femurs remain from the donor mice, enabling us to study specifically cells of the bone marrow niche using this model. We also showed that genetic ablation of peri-arteriolar cells specifically in donor femurs reduced the numbers of hematopoietic stem cells in these bones. This supports the use of this strategy as a model, in combination with genetic tools, to evaluate how bone marrow niche specific modifications may impact non-modified hematopoietic stem cells. Thus, this approach can be utilized for genetic manipulation in vivo of specific cell types only within the bone marrow. The combination of whole bone subcutaneous transplantation with rodent transgenic models will facilitate a more precise, complex and comprehensive understanding of existing problems in the study of the hematopoietic stem cell bone marrow niche.
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Affiliation(s)
- Caroline C Picoli
- Department of Pathology, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | | | - Xiao Lin Casey Wong
- Department of Dermatology, University of Wisconsin-Madison, Medical Sciences Center, Rm 4385, 1300 University Avenue, Madison, WI, 53706, USA
| | - Thamires Righi
- Department of Dermatology, University of Wisconsin-Madison, Medical Sciences Center, Rm 4385, 1300 University Avenue, Madison, WI, 53706, USA.,Department of Pharmacology, Federal University of São Paulo, São Paulo, SP, Brazil
| | - Pedro P G Guimarães
- Department of Physiology and Biophysics, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Mauro C X Pinto
- Institute of Biological Sciences, Federal University of Goiás, Goiânia, GO, Brazil
| | - Jaime H Amorim
- Center of Biological Sciences and Health, Federal University of West Bahia, Barreiras, BA, Brazil
| | - Vasco A C Azevedo
- Department of Genetics, Ecology and Evolution, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | | | - Alexandre Kanashiro
- Department of Dermatology, University of Wisconsin-Madison, Medical Sciences Center, Rm 4385, 1300 University Avenue, Madison, WI, 53706, USA
| | - Fabio Cardoso Cruz
- Department of Pharmacology, Federal University of São Paulo, São Paulo, SP, Brazil
| | - Rodrigo R Resende
- Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Akiva Mintz
- Department of Radiology, Columbia University Medical Center, New York, NY, USA
| | - Paul S Frenette
- Gottesman Institute for Stem Cell and Regenerative Medicine Research, Albert Einstein College of Medicine, Bronx, New York, NY, USA.,Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY, USA.,Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Alexander Birbrair
- Department of Pathology, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil. .,Department of Dermatology, University of Wisconsin-Madison, Medical Sciences Center, Rm 4385, 1300 University Avenue, Madison, WI, 53706, USA. .,Department of Radiology, Columbia University Medical Center, New York, NY, USA.
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8
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Lavado-García J, Pérez-Rubio P, Cervera L, Gòdia F. The cell density effect in animal cell-based bioprocessing: Questions, insights and perspectives. Biotechnol Adv 2022; 60:108017. [PMID: 35809763 DOI: 10.1016/j.biotechadv.2022.108017] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 05/31/2022] [Accepted: 07/01/2022] [Indexed: 11/28/2022]
Abstract
One of the main challenges in the development of bioprocesses based on cell transient expression is the commonly reported reduction of cell specific productivity at increasing cell densities. This is generally known as the cell density effect (CDE). Many efforts have been devoted to understanding the cell metabolic implications to this phenomenon in an attempt to design operational strategies to overcome it. A comprehensive analysis of the main studies regarding the CDE is provided in this work to better define the elements comprising its cause and impact. Then, examples of methodologies and approaches employed to achieve successful transient expression at high cell densities (HCD) are thoroughly reviewed. A critical assessment of the limitations of the reported studies in the understanding of the CDE is presented, covering the leading hypothesis of the molecular implications. The overall analysis of previous work on CDE may offer useful insights for further research into manufacturing of biologics.
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Affiliation(s)
- Jesús Lavado-García
- Grup d'Enginyeria Cel·lular i Bioprocessos, Escola d'Enginyeria, Universitat Autònoma de Barcelona, Campus de Bellaterra, Cerdanyola del Vallès, 08193 Barcelona, Spain; Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
| | - Pol Pérez-Rubio
- Grup d'Enginyeria Cel·lular i Bioprocessos, Escola d'Enginyeria, Universitat Autònoma de Barcelona, Campus de Bellaterra, Cerdanyola del Vallès, 08193 Barcelona, Spain
| | - Laura Cervera
- Grup d'Enginyeria Cel·lular i Bioprocessos, Escola d'Enginyeria, Universitat Autònoma de Barcelona, Campus de Bellaterra, Cerdanyola del Vallès, 08193 Barcelona, Spain
| | - Francesc Gòdia
- Grup d'Enginyeria Cel·lular i Bioprocessos, Escola d'Enginyeria, Universitat Autònoma de Barcelona, Campus de Bellaterra, Cerdanyola del Vallès, 08193 Barcelona, Spain
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9
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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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10
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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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11
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Bello SM, Perry MN, Smith CL. Know Your Model: A brief history of making mutant mouse genetic models. Lab Anim (NY) 2021; 50:263-266. [PMID: 34561680 DOI: 10.1038/s41684-021-00853-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Susan M Bello
- Mouse Genome Informatics, The Jackson Laboratory, Bar Harbor, ME, USA.
| | - Michelle N Perry
- Mouse Genome Informatics, The Jackson Laboratory, Bar Harbor, ME, USA
| | - Cynthia L Smith
- Mouse Genome Informatics, The Jackson Laboratory, Bar Harbor, ME, USA
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12
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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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Shin S, Kim SH, Lee JS, Lee GM. Streamlined Human Cell-Based Recombinase-Mediated Cassette Exchange Platform Enables Multigene Expression for the Production of Therapeutic Proteins. ACS Synth Biol 2021; 10:1715-1727. [PMID: 34133132 DOI: 10.1021/acssynbio.1c00113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A platform, based on targeted integration of transgenes using recombinase-mediated cassette exchange (RMCE) coupled with CRISPR/Cas9, is increasingly being used for the development of mammalian cell lines that produce therapeutic proteins, because of reduced clonal variation and predictable transgene expression. However, low efficiency of the RMCE process has hampered its application in multicopy or multisite integration of transgenes. To improve RMCE efficiency, nuclear transport of RMCE components such as site-specific recombinase and donor plasmid was accelerated by incorporation of nuclear localization signal and DNA nuclear-targeting sequence, respectively. Consequently, the efficiency of RMCE in dual-landing pad human embryonic kidney 293 (HEK293) cell lines harboring identical or orthogonal pairs of recombination sites at two well-known human safe harbors (AAVS1 and ROSA26 loci), increased 6.7- and 8.1-fold, respectively. This platform with enhanced RMCE efficiency enabled simultaneous integration of transgenes at the two sites using a single transfection without performing selection and enrichment processes. The use of a homotypic dual-landing pad HEK293 cell line capable of incorporating the same transgenes at two sites resulted in a 2-fold increase in the transgene expression level compared to a single-landing pad HEK293 cell line. In addition, the use of a heterotypic dual-landing pad HEK293 cell line, which can incorporate transgenes for a recombinant protein at one site and an effector transgene for cell engineering at another site, increased recombinant protein production. Overall, a streamlined RMCE platform can be a versatile tool for mammalian cell line development by facilitating multigene expression at genomic safe harbors.
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Affiliation(s)
- Seunghyeon Shin
- Department of Biological Sciences, KAIST, Daejeon 34141, Republic of Korea
| | - Su Hyun Kim
- Department of Biological Sciences, KAIST, Daejeon 34141, Republic of Korea
| | - Jae Seong Lee
- Department of Molecular Science and Technology, Ajou University, Suwon 16499, Republic of Korea
| | - Gyun Min Lee
- Department of Biological Sciences, KAIST, Daejeon 34141, Republic of Korea
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14
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Abstract
Conventional methods of DNA sequence insertion into plants, using Agrobacterium-mediated transformation or microprojectile bombardment, result in the integration of the DNA at random sites in the genome. These plants may exhibit altered agronomic traits as a consequence of disruption or silencing of genes that serve a critical function. Also, genes of interest inserted at random sites are often not expressed at the desired level. For these reasons, targeted DNA insertion at suitable genomic sites in plants is a desirable alternative. In this paper we review approaches of targeted DNA insertion in plant genomes, discuss current technical challenges, and describe promising applications of targeted DNA insertion for crop genetic improvement.
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15
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Feary M, Moffat MA, Casperson GF, Allen MJ, Young RJ. CHOK1SV GS-KO SSI expression system: A combination of the Fer1L4 locus and glutamine synthetase selection. Biotechnol Prog 2021; 37:e3137. [PMID: 33609084 DOI: 10.1002/btpr.3137] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 02/03/2021] [Accepted: 02/07/2021] [Indexed: 12/11/2022]
Abstract
There are an ever-increasing number of biopharmaceutical candidates in clinical trials fueling an urgent need to streamline the cell line development process. A critical part of the process is the methodology used to generate and screen candidate cell lines compatible with GMP manufacturing processes. The relatively large amount of clone phenotypic variation observed from conventional "random integration" (RI)-based cell line construction is thought to be the result of a combination of the position variegation effect, genome plasticity and clonal variation. Site-specific integration (SSI) has been used by several groups to temper the influence of the position variegation effect and thus reduce variability in expression of biopharmaceutical candidates. Following on from our previous reports on the application of the Fer1L4 locus for SSI in CHOK1SV (10E9), we have combined this locus and a CHOK1SV glutamine synthetase knockout (GS-KO) host to create an improved expression system. The host, CHOK1SV GS-KO SSI (HD7876), was created by homology directed integration of a targetable landing pad flanked with incompatible Frt sequences in the Fer1L4 gene. The targeting vector contains a promoterless GS expression cassette and monoclonal antibody (mAb) expression cassettes, flanked by Frt sites compatible with equivalent sites flanking the landing pad in the host cell line. SSI clones expressing four antibody candidates, selected in a streamlined cell line development process, have mAb titers which rival RI (1.0-4.5 g/L) and robust expression stability (100% of clones stable through the 50 generation "manufacturing window" which supports commercial manufacturing at 12,000 L bioreactor scale).
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Affiliation(s)
- Marc Feary
- R&D Cell Engineering, Lonza Biologics, Little Chesterford, UK
| | - Mark A Moffat
- Cell Line Development, Biotherapeutics Pharmaceutical Sciences, Pfizer Inc., Chesterfield, MO, 63017, USA
| | - Gerald F Casperson
- Cell Line Development, Biotherapeutics Pharmaceutical Sciences, Pfizer Inc., Chesterfield, MO, 63017, USA
| | - Martin J Allen
- Cell Line Development, Biotherapeutics Pharmaceutical Sciences, Pfizer Inc., Chesterfield, MO, 63017, USA
| | - Robert J Young
- R&D Cell Engineering, Lonza Biologics, Little Chesterford, UK
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16
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Ahmed HMM, Heese F, Wimmer EA. Improvement on the genetic engineering of an invasive agricultural pest insect, the cherry vinegar fly, Drosophila suzukii. BMC Genet 2020; 21:139. [PMID: 33339511 PMCID: PMC7747376 DOI: 10.1186/s12863-020-00940-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Background The invasive fly Drosophila suzukii has become an established fruit pest in Europe, the USA, and South America with no effective and safe pest management. Genetic engineering enables the development of transgene-based novel genetic control strategies against insect pests and disease vectors. This, however, requires the establishment of reliable germline transformation techniques. Previous studies have shown that D. suzukii is amenable to transgenesis using the transposon-based vectors piggyBac and Minos, site-specific recombination (lox/Cre), and CRISPR/Cas9 genome editing. Results We experienced differences in the usability of piggyBac-based germline transformation in different strains of D. suzukii: we obtained no transgenic lines in a US strain, a single rare transgenic line in an Italian strain, but observed a reliable transformation rate of 2.5 to 11% in a strain from the French Alps. This difference in efficiency was confirmed by comparative examination of these three strains. In addition, we used an attP landing site line to successfully established φC31-integrase-mediated plasmid integration at a rate of 10% and generated landing site lines with two attP sequences to effectively perform φC31-Recombinase Mediated Cassette Exchange (φC31-RMCE) with 11% efficiency. Moreover, we isolated and used the endogenous regulatory regions of Ds nanos to express φC31 integrase maternally to generate self-docking lines for φC31-RMCE. Besides, we isolated the promoter/enhancer of Ds serendipity α to drive the heterologous tetracycline-controlled transactivator (tTA) during early embryonic development and generated a testes-specific tTA driver line using the endogenous beta-2-tubulin (β2t) promoter/enhancer. Conclusion Our results provide evidence that the D. suzukii strain AM derived from the French Alps is more suitable for piggyBac germline transformation than other strains. We demonstrated the feasibility of using φC31-RMCE in the cherry vinegar fly and generated a set of lines that can be used for highly efficient integration of larger constructs. The φC31-based integration will facilitate modification and stabilization of previously generated transgenic lines that carry at least one attP site in the transgene construction. An early embryo-specific and a spermatogenesis-specific driver line were generated for future use of the binary expression system tet-off to engineer tissue- and stage-specific effector gene expression for genetic pest control strategies. Supplementary Information The online version contains supplementary material available at 10.1186/s12863-020-00940-5.
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Affiliation(s)
- Hassan M M Ahmed
- Department of Developmental Biology, Johann-Friedrich-Blumenbach-Institute of Zoology and Anthropology, Göttingen Center for Molecular Biosciences, Georg-August-University Göttingen, 37077, Göttingen, Germany.,Department of Crop Protection, Faculty of Agriculture-University of Khartoum, P.O. Box 32, 13314, Khartoum North, Khartoum, Sudan
| | - Fabienne Heese
- Department of Developmental Biology, Johann-Friedrich-Blumenbach-Institute of Zoology and Anthropology, Göttingen Center for Molecular Biosciences, Georg-August-University Göttingen, 37077, Göttingen, Germany
| | - Ernst A Wimmer
- Department of Developmental Biology, Johann-Friedrich-Blumenbach-Institute of Zoology and Anthropology, Göttingen Center for Molecular Biosciences, Georg-August-University Göttingen, 37077, Göttingen, Germany.
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17
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Sontayananon N, Redwood C, Davies B, Gehmlich K. Fluorescent PSC-Derived Cardiomyocyte Reporter Lines: Generation Approaches and Their Applications in Cardiovascular Medicine. BIOLOGY 2020; 9:biology9110402. [PMID: 33207727 PMCID: PMC7697758 DOI: 10.3390/biology9110402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/09/2020] [Accepted: 11/10/2020] [Indexed: 12/13/2022]
Abstract
Recent advances have made pluripotent stem cell (PSC)-derived cardiomyocytes an attractive option to model both normal and diseased cardiac function at the single-cell level. However, in vitro differentiation yields heterogeneous populations of cardiomyocytes and other cell types, potentially confounding phenotypic analyses. Fluorescent PSC-derived cardiomyocyte reporter systems allow specific cell lineages to be labelled, facilitating cell isolation for downstream applications including drug testing, disease modelling and cardiac regeneration. In this review, the different genetic strategies used to generate such reporter lines are presented with an emphasis on their relative technical advantages and disadvantages. Next, we explore how the fluorescent reporter lines have provided insights into cardiac development and cardiomyocyte physiology. Finally, we discuss how exciting new approaches using PSC-derived cardiomyocyte reporter lines are contributing to progress in cardiac cell therapy with respect to both graft adaptation and clinical safety.
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Affiliation(s)
- Naeramit Sontayananon
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford OX3 9DU, UK; (N.S.); (C.R.)
| | - Charles Redwood
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford OX3 9DU, UK; (N.S.); (C.R.)
| | - Benjamin Davies
- Wellcome Centre for Human Genetics, Roosevelt Drive, Oxford OX3 7BN, UK
- Correspondence: (B.D.); (K.G.)
| | - Katja Gehmlich
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford OX3 9DU, UK; (N.S.); (C.R.)
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham B15 2TT, UK
- Correspondence: (B.D.); (K.G.)
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18
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Metabolic Effects of Selective Deletion of Group VIA Phospholipase A 2 from Macrophages or Pancreatic Islet Beta-Cells. Biomolecules 2020; 10:biom10101455. [PMID: 33080873 PMCID: PMC7602969 DOI: 10.3390/biom10101455] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 10/08/2020] [Accepted: 10/13/2020] [Indexed: 12/11/2022] Open
Abstract
To examine the role of group VIA phospholipase A2 (iPLA2β) in specific cell lineages in insulin secretion and insulin action, we prepared mice with a selective iPLA2β deficiency in cells of myelomonocytic lineage, including macrophages (MØ-iPLA2β-KO), or in insulin-secreting β-cells (β-Cell-iPLA2β-KO), respectively. MØ-iPLA2β-KO mice exhibited normal glucose tolerance when fed standard chow and better glucose tolerance than floxed-iPLA2β control mice after consuming a high-fat diet (HFD). MØ-iPLA2β-KO mice exhibited normal glucose-stimulated insulin secretion (GSIS) in vivo and from isolated islets ex vivo compared to controls. Male MØ-iPLA2β-KO mice exhibited enhanced insulin responsivity vs. controls after a prolonged HFD. In contrast, β-cell-iPLA2β-KO mice exhibited impaired glucose tolerance when fed standard chow, and glucose tolerance deteriorated further when introduced to a HFD. β-Cell-iPLA2β-KO mice exhibited impaired GSIS in vivo and from isolated islets ex vivo vs. controls. β-Cell-iPLA2β-KO mice also exhibited an enhanced insulin responsivity compared to controls. These findings suggest that MØ iPLA2β participates in HFD-induced deterioration in glucose tolerance and that this mainly reflects an effect on insulin responsivity rather than on insulin secretion. In contrast, β-cell iPLA2β plays a role in GSIS and also appears to confer some protection against deterioration in β-cell functions induced by a HFD.
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19
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Jensen O, Ansari S, Gebauer L, Müller SF, Lowjaga KAAT, Geyer J, Tzvetkov MV, Brockmöller J. A double-Flp-in method for stable overexpression of two genes. Sci Rep 2020; 10:14018. [PMID: 32820202 PMCID: PMC7441062 DOI: 10.1038/s41598-020-71051-5] [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: 05/19/2020] [Accepted: 07/30/2020] [Indexed: 12/29/2022] Open
Abstract
Overexpression of single genes in mammalian cells is widely used to investigate protein function in basic and applied biosciences and in drug research. A better understanding of interactions of two proteins is an important next step in the advancement of our understanding of complex biological systems. However, simultaneous and robust overexpression of two or more genes is challenging. The Flp-In system integrates a vector into cell lines at a specific genomic locus, but has not been used for integration of more than one gene. Here we present a modification of the Flp-In system that enables the simultaneous targeted integration of two genes. We describe the modification and generation of the vectors required and give the complete protocol for transfection and validation of correct genomic integration and expression. We also provide results on the stability and reproducibility, and we functionally validated this approach with a pharmacologically relevant combination of a membrane transporter facilitating drug uptake and an enzyme mediating drug metabolism.
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Affiliation(s)
- Ole Jensen
- Institute of Clinical Pharmacology, University Medical Center Göttingen, Georg-August University, Robert-Koch-Str. 40, 37075, Göttingen, Germany.
| | - Salim Ansari
- Institute of Clinical Pharmacology, University Medical Center Göttingen, Georg-August University, Robert-Koch-Str. 40, 37075, Göttingen, Germany
| | - Lukas Gebauer
- Institute of Clinical Pharmacology, University Medical Center Göttingen, Georg-August University, Robert-Koch-Str. 40, 37075, Göttingen, Germany
| | - Simon F Müller
- Institute of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Justus Liebig University Giessen, 35392, Giessen, Germany
| | - Kira A A T Lowjaga
- Institute of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Justus Liebig University Giessen, 35392, Giessen, Germany
| | - Joachim Geyer
- Institute of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Justus Liebig University Giessen, 35392, Giessen, Germany
| | - Mladen V Tzvetkov
- Institute of Clinical Pharmacology, University Medical Center Göttingen, Georg-August University, Robert-Koch-Str. 40, 37075, Göttingen, Germany.,Institute of Pharmacology, Center of Drug Absorption and Transport (C_DAT), University Medical Center Greifswald, 17489, Greifswald, Germany
| | - Jürgen Brockmöller
- Institute of Clinical Pharmacology, University Medical Center Göttingen, Georg-August University, Robert-Koch-Str. 40, 37075, Göttingen, Germany
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20
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Kabir MT, Uddin MS, Setu JR, Ashraf GM, Bin-Jumah MN, Abdel-Daim MM. Exploring the Role of PSEN Mutations in the Pathogenesis of Alzheimer's Disease. Neurotox Res 2020; 38:833-849. [PMID: 32556937 DOI: 10.1007/s12640-020-00232-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 05/24/2020] [Accepted: 05/28/2020] [Indexed: 12/25/2022]
Abstract
Alzheimer's disease (AD) is the most common cause of dementia. Mutations of presenilin (PSEN) genes that encode presenilin proteins have been found as the vital causal factors for early-onset familial AD (FAD). AD pathological features such as memory loss, synaptic dysfunction, and formation of plaques have been successfully mimicked in the transgenic mouse models that coexpress FAD-related presenilin and amyloid precursor protein (APP) variants. γ-Secretase (GS) is an enzyme that plays roles in catalyzing intramembranous APP proteolysis to release pathogenic amyloid beta (Aβ). It has been found that presenilins can play a role as the GS's catalytic subunit. FAD-related mutations in presenilins can modify the site of GS cleavage in a way that can elevate the production of longer and highly fibrillogenic Aβ. Presenilins can interact with β-catenin to generate presenilin complexes. Aforesaid interactions have also been studied to observe the mutational and physiological activities in the catenin signal transduction pathway. Along with APP, GS can catalyze intramembrane proteolysis of various substrates that play a vital role in synaptic function. PSEN mutations can cause FAD with autosomal dominant inheritance and early onset of the disease. In this article, we have reviewed the current progress in the analysis of PSENs and the correlation of PSEN mutations and AD pathogenesis.
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Affiliation(s)
| | - Md Sahab Uddin
- Department of Pharmacy, Southeast University, Dhaka, Bangladesh. .,Pharmakon Neuroscience Research Network, Dhaka, Bangladesh.
| | | | - Ghulam Md Ashraf
- King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia.,Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - May N Bin-Jumah
- Department of Biology, College of Science, Princess Nourah bint Abdulrahman University, Riyadh, 11474, Saudi Arabia
| | - Mohamed M Abdel-Daim
- Department of Zoology, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia.,Pharmacology Department, Faculty of Veterinary Medicine, Suez Canal University, Ismailia, 41522, Egypt
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21
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Matsushima A, Graybiel AM. Combinatorial Developmental Controls on Striatonigral Circuits. Cell Rep 2020; 31:107778. [PMID: 32553154 PMCID: PMC7433760 DOI: 10.1016/j.celrep.2020.107778] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 02/12/2020] [Accepted: 05/27/2020] [Indexed: 11/17/2022] Open
Abstract
Cortical pyramidal cells are generated locally, from pre-programmed progenitors, to form functionally distinct areas. By contrast, striatal projection neurons (SPNs) are generated remotely from a common source, undergo migration to form mosaics of striosomes and matrix, and become incorporated into functionally distinct sectors. Striatal circuits might thus have a unique logic of developmental organization, distinct from those of the neocortex. We explore this possibility in mice by mapping one set of SPNs, those in striosomes, with striatonigral projections to the dopamine-containing substantia nigra pars compacta (SNpc). Same-age SPNs exhibit topographic striatonigral projections, according to their resident sector. However, the different birth dates of resident SPNs within a given sector specify the destination of their axons within the SNpc. These findings highlight a logic intercalating birth date-dependent and birth date-independent factors in determining the trajectories of SPN axons and organizing specialized units of striatonigral circuitry that could influence behavioral expression and vulnerabilities to disease.
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Affiliation(s)
- Ayano Matsushima
- McGovern Institute for Brain Research and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 20139, USA
| | - Ann M Graybiel
- McGovern Institute for Brain Research and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 20139, USA.
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22
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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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23
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Brown DM, Glass JI. Technology used to build and transfer mammalian chromosomes. Exp Cell Res 2020; 388:111851. [PMID: 31952951 DOI: 10.1016/j.yexcr.2020.111851] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 01/09/2020] [Accepted: 01/14/2020] [Indexed: 01/05/2023]
Abstract
In the near twenty-year existence of the human and mammalian artificial chromosome field, the technologies for artificial chromosome construction and installation into desired cell types or organisms have evolved with the rest of modern molecular and synthetic biology. Medical, industrial, pharmaceutical, agricultural, and basic research scientists seek the as yet unrealized promise of human and mammalian artificial chromosomes. Existing technologies for both top-down and bottom-up approaches to construct these artificial chromosomes for use in higher eukaryotes are very different but aspire to achieve similar results. New capacity for production of chromosome sized synthetic DNA will likely shift the field towards more bottom-up approaches, but not completely. Similarly, new approaches to install human and mammalian artificial chromosomes in target cells will compete with the microcell mediated cell transfer methods that currently dominate the field.
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Abstract
Clostridia are a group of Gram-positive anaerobic bacteria of medical and industrial importance for which limited genetic methods are available. Here, we demonstrate an approach to make large genomic deletions and insertions in the model Clostridium phytofermentans by combining designed group II introns (targetrons) and Cre recombinase. We apply these methods to delete a 50-gene prophage island by programming targetrons to position markerless lox66 and lox71 sites, which mediate deletion of the intervening 39-kb DNA region using Cre recombinase. Gene expression and growth of the deletion strain showed that the prophage genes contribute to fitness on nonpreferred carbon sources. We also inserted an inducible fluorescent reporter gene into a neutral genomic site by recombination-mediated cassette exchange (RMCE) between genomic and plasmid-based tandem lox sites bearing heterospecific spacers to prevent intracassette recombination. These approaches generally enable facile markerless genome engineering in clostridia to study their genome structure and regulation.IMPORTANCE Clostridia are anaerobic bacteria with important roles in intestinal and soil microbiomes. The inability to experimentally modify the genomes of clostridia has limited their study and application in biotechnology. Here, we developed a targetron-recombinase system to efficiently make large targeted genomic deletions and insertions using the model Clostridium phytofermentans We applied this approach to reveal the importance of a prophage to host fitness and introduce an inducible reporter by recombination-mediated cassette exchange.
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25
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Targeted Forward Genetics: Population-Scale Analyses of Allele Replacements Spanning Thousands of Base Pairs in Fission Yeast. G3-GENES GENOMES GENETICS 2019; 9:4097-4106. [PMID: 31597677 PMCID: PMC6893178 DOI: 10.1534/g3.119.400805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Precise allele replacement (genome editing), without unwanted changes to the genome, provides a powerful tool to define the functions of DNA elements and encoded factors in their normal biological context. While CRISPR is now used extensively for gene targeting, its utility for precise allele replacement at population scale is limited because: (A) there is a strict requirement for a correctly positioned PAM motif to introduce recombinogenic dsDNA breaks (DSBs); (B) efficient replacements only occur very close to the DSBs; and (C) indels and off-target changes are frequently generated. Here we show, using a saturated mutation library with about 15,000 alleles of the ade6 gene of Schizosaccharomyces pombe, that pop-in, pop-out allele replacement circumvents these problems. Two rounds of selection ensure that clones arise by homologous recombination with the target locus. Moreover, the exceptionally high efficiency allows one to carry out the process in bulk, then screen individual clones for phenotypes and genotypes. Alleles were introduced successfully throughout the region targeted, up to 1,956 base pairs from the DSB. About 11% of mutant alleles were hypomorphic, demonstrating utility for analyses of essential genes and genetic elements. This process of “targeted forward genetics” can be used to analyze comprehensively, across thousands of base pairs within a specific target region, a variety of allelic changes, such as scanning amino acid substitutions, deletions, and epitope tags. The overall approach and optimized workflow are extensible to other organisms that support gene targeting.
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26
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Sterner ZR, Rankin SA, Wlizla M, Choi JA, Luedeke DM, Zorn AM, Buchholz DR. Novel vectors for functional interrogation of
Xenopus
ORFeome coding sequences. Genesis 2019; 57:e23329. [DOI: 10.1002/dvg.23329] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 07/10/2019] [Accepted: 07/11/2019] [Indexed: 12/18/2022]
Affiliation(s)
- Zachary R. Sterner
- Department of Biological SciencesUniversity of Cincinnati Cincinnati Ohio
| | - Scott A. Rankin
- Division of Developmental BiologyCincinnati Children's Research Foundation Cincinnati Ohio
- Department of Pediatrics, College of MedicineUniversity of Cincinnati Cincinnati Ohio
| | - Marcin Wlizla
- Division of Developmental BiologyCincinnati Children's Research Foundation Cincinnati Ohio
- Department of Pediatrics, College of MedicineUniversity of Cincinnati Cincinnati Ohio
| | - Jinyoung A. Choi
- Department of Biological SciencesUniversity of Cincinnati Cincinnati Ohio
| | - David M. Luedeke
- Division of Developmental BiologyCincinnati Children's Research Foundation Cincinnati Ohio
- Department of Pediatrics, College of MedicineUniversity of Cincinnati Cincinnati Ohio
| | - Aaron M. Zorn
- Division of Developmental BiologyCincinnati Children's Research Foundation Cincinnati Ohio
- Department of Pediatrics, College of MedicineUniversity of Cincinnati Cincinnati Ohio
| | - Daniel R. Buchholz
- Department of Biological SciencesUniversity of Cincinnati Cincinnati Ohio
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27
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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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Liu S, Li J, Wang T, Xu J, Liu Z, Wang H, Wei GH, Ianni A, Braun T, Yue S. Illumination of cell cycle progression by multi-fluorescent sensing system. Cell Cycle 2019; 18:1364-1378. [PMID: 31131683 DOI: 10.1080/15384101.2019.1618117] [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] [Indexed: 10/26/2022] Open
Abstract
Multi-fluorescent imaging of cell cycle progression is essential for the study of cell proliferation in vitro and in vivo. However, there remain challenges, particularly to image cell cycle progression in living cell with available imaging techniques due to lacking the suitable probe. Here, we design a triple fluorescent sensors system making the cell cycle progression visible. Multi-fluorescent sensor shows the proliferating or proliferated cells with different colors. We thus generate the construct and adenovirus to probe cell cycle progression in living cell lines and primary cardiomyocytes. Furthermore, we create the knock-in transgenic mouse to monitor cell cycle progression in vivo. Together, the system can be applied to investigate cell proliferation or cell cycle progression in living cells and animals.
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Affiliation(s)
- Shuo Liu
- a State Key Laboratory of Medicinal Chemical Biology , Nankai University , Tianjin , China.,b School of Medicine , Nankai University , Tianjin , China
| | - Jun Li
- a State Key Laboratory of Medicinal Chemical Biology , Nankai University , Tianjin , China.,b School of Medicine , Nankai University , Tianjin , China
| | - Teng Wang
- a State Key Laboratory of Medicinal Chemical Biology , Nankai University , Tianjin , China.,b School of Medicine , Nankai University , Tianjin , China
| | - Jiawen Xu
- a State Key Laboratory of Medicinal Chemical Biology , Nankai University , Tianjin , China.,b School of Medicine , Nankai University , Tianjin , China
| | - Zhipei Liu
- c Department of Cardiac Development and Remodeling , Max-Planck-Institute for Heart and Lung Research , Bad Nauheim , Germany.,d Union Gene Test & Health Management Center , Tianjin , China
| | - Haobin Wang
- e Department of Breast & Thyroid Surgery , The third people's hospital of Chengdu; The Affiliated Hospital of Southwest Jiaotong University , Chengdu , China
| | - Gong-Hong Wei
- f Biocenter Oulu, Faculty of Biochemistry and Molecular Medicine , University of Oulu , Oulu , Finland
| | - Alessandro Ianni
- c Department of Cardiac Development and Remodeling , Max-Planck-Institute for Heart and Lung Research , Bad Nauheim , Germany
| | - Thomas Braun
- c Department of Cardiac Development and Remodeling , Max-Planck-Institute for Heart and Lung Research , Bad Nauheim , Germany
| | - Shijing Yue
- a State Key Laboratory of Medicinal Chemical Biology , Nankai University , Tianjin , China.,b School of Medicine , Nankai University , Tianjin , China.,c Department of Cardiac Development and Remodeling , Max-Planck-Institute for Heart and Lung Research , Bad Nauheim , Germany
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29
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Rozov SM, Deineko EV. Strategies for Optimizing Recombinant Protein Synthesis in Plant Cells: Classical Approaches and New Directions. Mol Biol 2019. [DOI: 10.1134/s0026893319020146] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Couasnay G, Frey C, Elefteriou F. Promoter Cre-Specific Genotyping Assays for Authentication of Cre-Driver Mouse Lines. JBMR Plus 2019; 3:e10128. [PMID: 31044186 PMCID: PMC6478581 DOI: 10.1002/jbm4.10128] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 10/17/2018] [Accepted: 10/21/2018] [Indexed: 11/07/2022] Open
Abstract
The Cre-LoxP system gene knockout (KO) technology provides cell- and time-specificity of gene ablation to investigate cell-autonomous gene function in vivo, and is paramount for understanding the function of genes involved in bone development, remodeling, and repair. This approach permits gene ablation in a cell- or tissue-specific, differentiation stage-specific, and inducible manner, thanks to the use of well-chosen promoters that drive expression of the Cre recombinase in selected cells/tissues. The generation of these powerful tools has led to the expansion of Cre mouse lines available to the research community, which are often shared within and between laboratories. Although convenient and commonly used, genotyping these Cre lines with a generic set of primers that amplifies the Cre transgene does not distinguish between various Cre-deleter lines. This practice poses the significant risk of mistakenly swapping Cre lineages, as laboratories often host and handle several lines at a time and utilize multiple lines per project. In line with the NIH-led effort to promote authentication of biological reagents and increase scientific rigor, we report here strategies for designing appropriate sets of primers able to discriminate some of most widely used Cre-deleter mouse lines in the field of bone biology, and the validation of 24 of them.
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Affiliation(s)
| | | | - Florent Elefteriou
- Department of Orthopedic Surgery
- Departments of Human and Molecular GeneticsBaylor College of MedicineHoustonTXUSA
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31
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Abstract
Vector control programs based on population reduction by matings with mass-released sterile insects require the release of only male mosquitoes, as the release of females, even if sterile, would increase the number of biting and potentially disease-transmitting individuals. While small-scale releases demonstrated the applicability of sterile males releases to control the yellow fever mosquito Aedes aegypti, large-scale programs for mosquitoes are currently prevented by the lack of efficient sexing systems in any of the vector species.Different approaches of sexing are pursued, including classical genetic and mechanical methods of sex separation. Another strategy is the development of transgenic sexing systems. Such systems already exist in other insect pests. Genome modification tools could be used to apply similar strategies to mosquitoes. Three major tools to modify mosquito genomes are currently used: transposable elements, site-specific recombination systems, and genome editing via TALEN or CRISPR/Cas. All three can serve the purpose of developing sexing systems and vector control strains in mosquitoes in two ways: first, via their use in basic research. A better understanding of mosquito biology, including the sex-determining pathways and the involved genes can greatly facilitate the development of sexing strains. Moreover, basic research can help to identify other regulatory elements and genes potentially useful for the construction of transgenic sexing systems. Second, these genome modification tools can be used to apply the gained knowledge to build and test mosquito sexing strains for vector control.
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Affiliation(s)
- Irina Häcker
- Institute for Insect Biotechnology, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 26-32, 35392, Giessen, Germany.
| | - Marc F Schetelig
- Institute for Insect Biotechnology, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 26-32, 35392, Giessen, Germany
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Leidy-Davis T, Cheng K, Goodwin LO, Morgan JL, Juan WC, Roca X, Ong ST, Bergstrom DE. Viable Mice with Extensive Gene Humanization (25-kbp) Created Using Embryonic Stem Cell/Blastocyst and CRISPR/Zygote Injection Approaches. Sci Rep 2018; 8:15028. [PMID: 30301924 PMCID: PMC6177426 DOI: 10.1038/s41598-018-33408-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 09/28/2018] [Indexed: 02/06/2023] Open
Abstract
Here, we describe an expansion of the typical DNA size limitations associated with CRISPR knock-in technology, more specifically, the physical extent to which mouse genomic DNA can be replaced with donor (in this case, human) DNA at an orthologous locus by zygotic injection. Driving our efforts was the desire to create a whole animal model that would replace 17 kilobase pairs (kbp) of the mouse Bcl2l11 gene with the corresponding 25-kbp segment of human BCL2L11, including a conditionally removable segment (2.9-kbp) of intron 2, a cryptic human exon immediately 3' of this, and a native human exon some 20 kbp downstream. Using two methods, we first carried out the replacement by employing a combination of bacterial artificial chromosome recombineering, classic embryonic stem cell (ESC) targeting, dual selection, and recombinase-driven cassette removal (ESC/Blastocyst Approach). Using a unique second method, we employed the same vector (devoid of its selectable marker cassettes), microinjecting it along with redundant single guide RNAs (sgRNAs) and Cas9 mRNA into mouse zygotes (CRISPR/Zygote Approach). In both instances, we were able to achieve humanization of Bcl2l11 to the extent designed, remove all selection cassettes, and demonstrate the functionality of the conditionally removable, loxP-flanked, 2.9-kbp intronic segment.
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Affiliation(s)
| | - Kai Cheng
- Genetic Resource Science, The Jackson Laboratory, Bar Harbor, ME, USA
- Genetically Engineered Models and Services, Charles River Laboratories, Wilmington, USA
| | - Leslie O Goodwin
- Genetic Resource Science, The Jackson Laboratory, Bar Harbor, ME, USA
| | - Judith L Morgan
- Genetic Resource Science, The Jackson Laboratory, Bar Harbor, ME, USA
- Center for Biometric Analysis, The Jackson Laboratory, Bar Harbor, USA
| | - Wen Chun Juan
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore
- MSD Pharma (Singapore) Private Limited, Singapore, Republic of Singapore
| | - Xavier Roca
- School of Biological Sciences, Nanyang Technological University, Singapore, Republic of Singapore
| | - S Tiong Ong
- Cancer and Stem Cell Biology Signature Research Programme, Duke-NUS Medical School, Singapore, Republic of Singapore
- Department of Haematology, Singapore General Hospital, Singapore, Republic of Singapore
- Department of Medical Oncology, National Cancer Centre, Singapore, Republic of Singapore
- Department of Medicine, Duke University Medical Center, Durham, NC, USA
| | - David E Bergstrom
- Genetic Resource Science, The Jackson Laboratory, Bar Harbor, ME, USA.
- Cancer Center, The Jackson Laboratory, Bar Harbor, ME, USA.
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O’Brien SA, Lee K, Fu HY, Lee Z, Le TS, Stach CS, McCann MG, Zhang AQ, Smanski MJ, Somia NV, Hu WS. Single Copy Transgene Integration in a Transcriptionally Active Site for Recombinant Protein Synthesis. Biotechnol J 2018; 13:e1800226. [PMID: 30024101 PMCID: PMC7058118 DOI: 10.1002/biot.201800226] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 07/09/2018] [Indexed: 12/21/2022]
Abstract
For the biomanufacturing of protein biologics, establishing stable cell lines with high transgene transcription is critical for high productivity. Modern genome engineering tools can direct transgene insertion to a specified genomic locus and can potentially become a valuable tool for cell line generation. In this study, the authors survey transgene integration sites and their transcriptional activity to identify characteristics of desirable regions. A lentivirus containing destabilized Green Fluorescent Protein (dGFP) is used to infect Chinese hamster ovary cells at a low multiplicity of infection, and cells with high or low GFP fluorescence are isolated. RNA sequencing and Assay for Transposase Accessible Chromatin using sequencing data shows integration sites with high GFP expression are in larger regions of high transcriptional activity and accessibility, but not necessarily within highly transcribed genes. This method is used to obtain high Immunoglobulin G (IgG) expressing cell lines with a single copy of the transgene integrated into transcriptionally active and accessible genomic regions. Dual recombinase-mediated cassette exchange is then employed to swap the IgG transgene for erythropoietin or tumor necrosis factor receptor-Fc. This work thus highlights a strategy to identify desirable sites for transgene integration and to streamline the development of new product producing cell lines.
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Affiliation(s)
- Sofie A. O’Brien
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455-0132 USA
| | - Kyoungho Lee
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455-0132 USA
| | - Hsu-Yuan Fu
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455-0132 USA
| | - Zion Lee
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455-0132 USA
| | - Tung S. Le
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455-0132 USA
| | - Christopher S. Stach
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455-0132 USA
| | - Meghan G. McCann
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455-0132 USA
| | - Alicia Q. Zhang
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455-0132 USA
| | - Michael J. Smanski
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455-0132 USA
| | - Nikunj V. Somia
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455-0132 USA
| | - Wei-Shou Hu
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455-0132 USA
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34
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Nomura W. Development of Toolboxes for Precision Genome/Epigenome Editing and Imaging of Epigenetics. CHEM REC 2018; 18:1717-1726. [PMID: 30066981 DOI: 10.1002/tcr.201800036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 07/17/2018] [Indexed: 12/17/2022]
Abstract
Zinc finger (ZF) proteins are composed of repeated ββα modules and coordinate a zinc ion. ZF domains recognizing specific DNA target sequences can be substituted for the binding domains of various DNA-modifying enzymes to create designer nucleases, recombinases, and methyltransferases with programmable sequence specificity. Enzymatic genome editing and modification can be applied to many fields of basic research and medicine. The recent development of new platforms using transcription activator-like effector (TALE) proteins or the CRISPR-Cas9 system has expanded the range of possibilities for genome-editing technologies. In addition, these DNA binding domains can also be utilized to build a toolbox for epigenetic controls by fusing them with protein- or DNA-modifying enzymes. Here, our research on epigenome editing including the development of artificial zinc finger recombinase (ZFR), split DNA methyltransferase, and fluorescence imaging of histone proteins by ZIP tag-probe system is introduced. Advances in the ZF, TALE, and CRISPR-Cas9 platforms have paved the way for the next generation of genome/epigenome engineering approaches.
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Affiliation(s)
- Wataru Nomura
- Institute of Biomaterials and Bioenginerring, Tokyo Medical and Dental University, 2-3-10 Kandasurugadai, Chiyoda-ku, Tokyo, 101-0062, Japan
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35
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Efficient targeted integration into the bovine Rosa26 locus using TALENs. Sci Rep 2018; 8:10385. [PMID: 29991797 PMCID: PMC6039519 DOI: 10.1038/s41598-018-28502-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 06/04/2018] [Indexed: 02/03/2023] Open
Abstract
The genetic modification of cattle has many agricultural and biomedical applications. However, random integration often results in the unstable expression of transgenes and unpredictable phenotypes. Targeting genes to the "safe locus" and stably expressing foreign genes at a high level are desirable methods for overcoming these hurdles. The Rosa26 locus has been widely used to produce genetically modified animals in some species expressing transgenes at high and consistent levels. For the first time, we identified a bovine orthologue of the mouse Rosa26 locus through a genomic sequence homology analysis. According to 5' rapid-amplification of cDNA ends (5'RACE), 3' rapid-amplification of cDNA ends (3'RACE), reverse transcription PCR (RT-PCR) and quantitative PCR (Q-PCR) experiments, this locus encodes a long noncoding RNA (lncRNA) comprising two exons that is expressed ubiquitously and stably in different tissues. The bovine Rosa26 (bRosa26) locus appears to be highly amenable to transcription activator-like effector nucleases (TALENs)-mediated knock-in, and ubiquitous expression of enhanced green fluorescent protein (EGFP) inserted in the bRosa26 locus was observed in various stages, including cells, embryos, fetus and cattle. Finally, we created a valuable master bRosa26-EGFP fetal fibroblast cell line in which any gene of interest can be efficiently introduced and stably expressed using recombinase-mediated cassette exchange (RMCE). The new tools described here will be useful for a variety of studies using cattle.
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36
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Flexible pseudotyping of retrovirus using recombinase-mediated cassette exchange. Biotechnol Lett 2018; 40:633-639. [PMID: 29353442 PMCID: PMC5862940 DOI: 10.1007/s10529-018-2515-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 01/11/2018] [Indexed: 10/27/2022]
Abstract
OBJECTIVE Develop an engineered cell line containing two flexible gene expression systems enabling the continuous production of tailor-made recombinant gammaretrovirus with predictable productivities through targeted integration. RESULTS Dual-FLEX cells (dFLEX) contain two independent recombinase-mediated cassette exchange (RMCE) systems which confer flexibility to the expression of different transgene and envelope combinations. The flexible envelope expression in dFLEX cells was validated by pseudotyping retrovirus particles with three different viral envelope proteins-GaLV, 4070A and VSV-G. Our results show that dFLEX cells are able to provide high titers of infectious retroviral particles with a single-copy integration of the envelope constructs after RMCE. The integrated CRE/Lox tagging cassette was amenable to express envelope proteins both using constitutive (i.e. CMV) and inducible (i.e. Tet-on) promoters. CONCLUSIONS dFLEX cell line provides predictable productivities of recombinant retrovirus pseudotyped with different envelope proteins broadening the tropism of particles that can be generated and thus accelerating the research and development of retrovirus-based products.
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37
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Sengupta R, Mendenhall A, Sarkar N, Mukherjee C, Afshari A, Huang J, Lu B. Viral Cre-LoxP tools aid genome engineering in mammalian cells. J Biol Eng 2017; 11:45. [PMID: 29204184 PMCID: PMC5702101 DOI: 10.1186/s13036-017-0087-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 11/14/2017] [Indexed: 01/06/2023] Open
Abstract
Background Targeted nucleases have transformed genome editing technology, providing more efficient methods to make targeted changes in mammalian genome. In parallel, there is an increasing demand of Cre-LoxP technology for complex genome manipulation such as large deletion, addition, gene fusion and conditional removal of gene sequences at the target site. However, an efficient and easy-to-use Cre-recombinase delivery system remains lacking. Results We designed and constructed two sets of expression vectors for Cre-recombinase using two highly efficient viral systems, the integrative lentivirus and non-integrative adeno associated virus. We demonstrate the effectiveness of those methods in Cre-delivery into stably-engineered HEK293 cells harboring LoxP-floxed red fluorescent protein (RFP) and puromycin (Puro) resistant reporters. The delivered Cre recombinase effectively excised the floxed RFP-Puro either directly or conditionally, therefore validating the function of these molecular tools. Given the convenient options of two selections markers, these viral-based systems offer a robust and easy-to-use tool for advanced genome editing, expanding complicated genome engineering to a variety of cell types and conditions. Conclusions We have developed and functionally validated two viral-based Cre-recombinase delivery systems for efficient genome manipulation in various mammalian cells. The ease of gene delivery with the built-in reporters and inducible element enables live cell monitoring, drug selection and temporal knockout, broadening applications of genome editing.
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Affiliation(s)
- Ranjita Sengupta
- System Biosciences, 2436 Embarcadero Way, Palo Alto, CA 94303 USA
| | - Amy Mendenhall
- System Biosciences, 2436 Embarcadero Way, Palo Alto, CA 94303 USA
| | - Nandita Sarkar
- Gilead Sciences Inc., 333 Lakeside Drive, Foster City, CA 94404 USA
| | | | - Amirali Afshari
- System Biosciences, 2436 Embarcadero Way, Palo Alto, CA 94303 USA
| | - Joseph Huang
- System Biosciences, 2436 Embarcadero Way, Palo Alto, CA 94303 USA
| | - Biao Lu
- Department of Bioengineering, Santa Clara University, 500 El Camino Real, Santa Clara, CA 95053 USA
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38
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Stolfa G, Smonskey MT, Boniface R, Hachmann AB, Gulde P, Joshi AD, Pierce AP, Jacobia SJ, Campbell A. CHO-Omics Review: The Impact of Current and Emerging Technologies on Chinese Hamster Ovary Based Bioproduction. Biotechnol J 2017; 13:e1700227. [PMID: 29072373 DOI: 10.1002/biot.201700227] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 10/12/2017] [Accepted: 10/16/2017] [Indexed: 01/07/2023]
Abstract
CHO cells are the most prevalent platform for modern bio-therapeutic production. Currently, there are several CHO cell lines used in bioproduction with distinct characteristics and unique genotypes and phenotypes. These differences limit advances in productivity and quality that can be achieved by the most common approaches to bioprocess optimization and cell line engineering. Incorporating omics-based approaches into current bioproduction processes will complement traditional methodologies to maximize gains from CHO engineering and bioprocess improvements. In order to highlight the utility of omics technologies in CHO bioproduction, the authors discuss current applications as well as limitations of genomics, transcriptomics, proteomics, metabolomics, lipidomics, fluxomics, glycomics, and multi-omics approaches and the potential they hold for the future of bioproduction. Multiple omics approaches are currently being used to improve CHO bioprocesses; however, the application of these technologies is still limited. As more CHO-omic datasets become available and integrated into systems models, the authors expect significant gains in product yield and quality. While individual omics technologies provide incremental improvements in bioproduction, the authors will likely see the most significant gains by applying multi-omics and systems biology approaches to individual CHO cell lines.
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Affiliation(s)
- Gino Stolfa
- Bioproduction R&D, Thermo Fisher Scientific, Grand Island, USA
| | | | - Ryan Boniface
- Bioproduction R&D, Thermo Fisher Scientific, Grand Island, USA
| | | | - Paul Gulde
- Bioproduction R&D, Thermo Fisher Scientific, Grand Island, USA
| | - Atul D Joshi
- Bioproduction R&D, Thermo Fisher Scientific, Grand Island, USA
| | - Anson P Pierce
- Bioproduction R&D, Thermo Fisher Scientific, Grand Island, USA
| | - Scott J Jacobia
- Bioproduction R&D, Thermo Fisher Scientific, Grand Island, USA
| | - Andrew Campbell
- Bioproduction R&D, Thermo Fisher Scientific, Grand Island, USA
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39
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Baumann M, Gludovacz E, Sealover N, Bahr S, George H, Lin N, Kayser K, Borth N. Preselection of recombinant gene integration sites enabling high transcription rates in CHO cells using alternate start codons and recombinase mediated cassette exchange. Biotechnol Bioeng 2017; 114:2616-2627. [DOI: 10.1002/bit.26388] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 06/13/2017] [Accepted: 07/19/2017] [Indexed: 01/01/2023]
Affiliation(s)
- Martina Baumann
- Austrian Centre of Industrial Biotechnology (ACIB); Graz Austria
| | | | | | - Scott Bahr
- MilliporeSigma (SAFC); St. Louis Minnesota
| | | | - Nan Lin
- MilliporeSigma (SAFC); St. Louis Minnesota
| | | | - Nicole Borth
- Austrian Centre of Industrial Biotechnology (ACIB); Graz Austria
- University of Natural Resources and Life Sciences (BOKU); Vienna Austria
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40
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Ausländer S, Ausländer D, Fussenegger M. Synthetische Biologie - die Synthese der Biologie. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201609229] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Simon Ausländer
- Department of Biosystems Science and Engineering; ETH Zürich; Mattenstrasse 26 4058 Basel Schweiz
| | - David Ausländer
- Department of Biosystems Science and Engineering; ETH Zürich; Mattenstrasse 26 4058 Basel Schweiz
| | - Martin Fussenegger
- Department of Biosystems Science and Engineering; ETH Zürich; Mattenstrasse 26 4058 Basel Schweiz
- Faculty of Science; Universität Basel; Mattenstrasse 26 4058 Basel Schweiz
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41
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Ausländer S, Ausländer D, Fussenegger M. Synthetic Biology-The Synthesis of Biology. Angew Chem Int Ed Engl 2017; 56:6396-6419. [PMID: 27943572 DOI: 10.1002/anie.201609229] [Citation(s) in RCA: 107] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 11/17/2016] [Indexed: 01/01/2023]
Abstract
Synthetic biology concerns the engineering of man-made living biomachines from standardized components that can perform predefined functions in a (self-)controlled manner. Different research strategies and interdisciplinary efforts are pursued to implement engineering principles to biology. The "top-down" strategy exploits nature's incredible diversity of existing, natural parts to construct synthetic compositions of genetic, metabolic, or signaling networks with predictable and controllable properties. This mainly application-driven approach results in living factories that produce drugs, biofuels, biomaterials, and fine chemicals, and results in living pills that are based on engineered cells with the capacity to autonomously detect and treat disease states in vivo. In contrast, the "bottom-up" strategy seeks to be independent of existing living systems by designing biological systems from scratch and synthesizing artificial biological entities not found in nature. This more knowledge-driven approach investigates the reconstruction of minimal biological systems that are capable of performing basic biological phenomena, such as self-organization, self-replication, and self-sustainability. Moreover, the syntheses of artificial biological units, such as synthetic nucleotides or amino acids, and their implementation into polymers inside living cells currently set the boundaries between natural and artificial biological systems. In particular, the in vitro design, synthesis, and transfer of complete genomes into host cells point to the future of synthetic biology: the creation of designer cells with tailored desirable properties for biomedicine and biotechnology.
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Affiliation(s)
- Simon Ausländer
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, 4058, Basel, Switzerland
| | - David Ausländer
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, 4058, Basel, Switzerland
| | - Martin Fussenegger
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, 4058, Basel, Switzerland.,Faculty of Science, University of Basel, Mattenstrasse 26, 4058, Basel, Switzerland
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42
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Kelton W, Waindok AC, Pesch T, Pogson M, Ford K, Parola C, Reddy ST. Reprogramming MHC specificity by CRISPR-Cas9-assisted cassette exchange. Sci Rep 2017; 7:45775. [PMID: 28374766 PMCID: PMC5379551 DOI: 10.1038/srep45775] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 03/02/2017] [Indexed: 11/20/2022] Open
Abstract
The development of programmable nucleases has enabled the application of new genome engineering strategies for cellular immunotherapy. While targeted nucleases have mostly been used to knock-out or knock-in genes in immune cells, the scarless exchange of entire immunogenomic alleles would be of great interest. In particular, reprogramming the polymorphic MHC locus could enable the creation of matched donors for allogeneic cellular transplantation. Here we show a proof-of-concept for reprogramming MHC-specificity by performing CRISPR-Cas9-assisted cassette exchange. Using murine antigen presenting cell lines (RAW264.7 macrophages), we demonstrate that the generation of Cas9-induced double-stranded breaks flanking the native MHC-I H2-Kd locus led to exchange of an orthogonal H2-Kb allele. MHC surface expression allowed for easy selection of reprogrammed cells by flow cytometry, thus obviating the need for additional selection markers. MHC-reprogrammed cells were fully functional as they could present H2-Kd-restricted peptide and activate cognate T cells. Finally, we investigated the role of various donor template formats on exchange efficiency, discovering that templates that underwent in situ linearization resulted in the highest MHC-reprogramming efficiency. These findings highlight a potential new approach for the correcting of MHC mismatches in cellular transplantation.
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Affiliation(s)
- William Kelton
- Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland
| | - Ann Cathrin Waindok
- Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland
| | - Theresa Pesch
- Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland
| | - Mark Pogson
- Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland
| | - Kyle Ford
- Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland
| | - Cristina Parola
- Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland
| | - Sai T. Reddy
- Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland
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43
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Small animal models to understand pathogenesis of osteoarthritis and use of stem cell in cartilage regeneration. Cell Biochem Funct 2017; 35:3-11. [DOI: 10.1002/cbf.3246] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 11/06/2016] [Accepted: 12/04/2016] [Indexed: 01/05/2023]
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44
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Alves CS, Dobrowsky TM. Strategies and Considerations for Improving Expression of "Difficult to Express" Proteins in CHO Cells. Methods Mol Biol 2017; 1603:1-23. [PMID: 28493120 DOI: 10.1007/978-1-4939-6972-2_1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Despite substantial advances in the field of mammalian expression, there are still proteins that are characterized as difficult to express. Determining the expression bottleneck requires troubleshooting techniques specific for the given molecule and host. The complex array of intracellular processes involved in protein expression includes transcription, protein folding, post-translation processing, and secretion. Challenges in any of these steps could result in low protein expression, while the inherent properties of the molecule itself may limit its production via mechanisms such as cytotoxicity or inherent instability. Strategies to identify the rate-limiting step and subsequently improve expression and production are discussed here.
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45
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Bebel A, Karaca E, Kumar B, Stark WM, Barabas O. Structural snapshots of Xer recombination reveal activation by synaptic complex remodeling and DNA bending. eLife 2016; 5. [PMID: 28009253 PMCID: PMC5241119 DOI: 10.7554/elife.19706] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 12/21/2016] [Indexed: 02/06/2023] Open
Abstract
Bacterial Xer site-specific recombinases play an essential genome maintenance role by unlinking chromosome multimers, but their mechanism of action has remained structurally uncharacterized. Here, we present two high-resolution structures of Helicobacter pylori XerH with its recombination site DNA difH, representing pre-cleavage and post-cleavage synaptic intermediates in the recombination pathway. The structures reveal that activation of DNA strand cleavage and rejoining involves large conformational changes and DNA bending, suggesting how interaction with the cell division protein FtsK may license recombination at the septum. Together with biochemical and in vivo analysis, our structures also reveal how a small sequence asymmetry in difH defines protein conformation in the synaptic complex and orchestrates the order of DNA strand exchanges. Our results provide insights into the catalytic mechanism of Xer recombination and a model for regulation of recombination activity during cell division. DOI:http://dx.doi.org/10.7554/eLife.19706.001 Similar to humans, bacteria store their genetic material in the form of DNA and arrange it into structures called chromosomes. In fact, most bacteria have a single circular chromosome. Bacteria multiply by simply dividing in two, and before that happens they must replicate their DNA so that each of the newly formed cells receives one copy of the chromosome. Occasionally, mistakes during the DNA replication process can cause the two chromosomes to become tangled with each other; this prevents them from separating into the newly formed cells. For instance, the chromosomes can become physically connected like links in a chain, or merge into one long string. This kind of tangling can result in cell death, so bacteria encode enzymes called Xer recombinases that can untangle chromosomes. These enzymes separate the chromosomes by cutting and rejoining the DNA strands in a process known as Xer recombination. Although Xer recombinases have been studied in quite some detail, many questions remain unanswered about how they work. How do Xer recombinases interact with DNA? How do they ensure they only work on tangled chromosomes? And how does a protein called FtsK ensure that Xer recombination takes place at the correct time and place? Bebel et al. have now studied the Xer recombinase from a bacterium called Helicobacter pylori, which causes stomach ulcers, using a technique called X-ray crystallography. This enabled the three-dimensional structure of the Xer recombinase to be visualized as it interacted with DNA to form a Xer-DNA complex. Structures of the enzyme before and after it cut the DNA show that Xer-DNA complexes first assemble in an inactive state and are then activated by large conformational changes that make the DNA bend. Bebel et al. propose that the FtsK protein might trigger these changes and help to bend the DNA as it activates Xer recombination. Further work showed that the structures could be used to model and understand Xer recombinases from other species of bacteria. The next step is to analyze how FtsK activates Xer recombinases and to see if this process is universal amongst bacteria. Understanding how this process can be interrupted could help to develop new drugs that can kill harmful bacteria. DOI:http://dx.doi.org/10.7554/eLife.19706.002
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Affiliation(s)
- Aleksandra Bebel
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Ezgi Karaca
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Banushree Kumar
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - W Marshall Stark
- Institute of Molecular, Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
| | - Orsolya Barabas
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
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46
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Fan HF, Hsieh TS, Ma CH, Jayaram M. Single-molecule analysis of ϕC31 integrase-mediated site-specific recombination by tethered particle motion. Nucleic Acids Res 2016; 44:10804-10823. [PMID: 27986956 PMCID: PMC5159548 DOI: 10.1093/nar/gkw861] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 09/11/2016] [Accepted: 09/22/2016] [Indexed: 11/14/2022] Open
Abstract
Serine and tyrosine site-specific recombinases (SRs and YRs, respectively) provide templates for understanding the chemical mechanisms and conformational dynamics of strand cleavage/exchange between DNA partners. Current evidence suggests a rather intriguing mechanism for serine recombination, in which one half of the cleaved synaptic complex undergoes a 180° rotation relative to the other. The 'small' and 'large' SRs contain a compact amino-terminal catalytic domain, but differ conspicuously in their carboxyl-terminal domains. So far, only one serine recombinase has been analyzed using single substrate molecules. We now utilized single-molecule tethered particle motion (TPM) to follow step-by-step recombination catalyzed by a large SR, phage ϕC31 integrase. The integrase promotes unidirectional DNA exchange between attB and attP sites to integrate the phage genome into the host chromosome. The recombination directionality factor (RDF; ϕC31 gp3) activates the excision reaction (attL × attR). From integrase-induced changes in TPM in the presence or absence of gp3, we delineated the individual steps of recombination and their kinetic features. The gp3 protein appears to regulate recombination directionality by selectively promoting or excluding active conformations of the synapse formed by specific att site partners. Our results support a 'gated rotation' of the synaptic complex between DNA cleavage and joining.
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Affiliation(s)
- Hsiu-Fang Fan
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, 112, Taiwan
- Biophotonics and Molecular Imaging Research Center, National Yang-Ming University, 112, Taiwan
| | - Tao-Shih Hsieh
- Institute of Cellular and Organismic Biology Academia Sinica, 115, Taiwan
| | - Chien-Hui Ma
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Makkuni Jayaram
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
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47
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Chaikind B, Bessen JL, Thompson DB, Hu JH, Liu DR. A programmable Cas9-serine recombinase fusion protein that operates on DNA sequences in mammalian cells. Nucleic Acids Res 2016; 44:9758-9770. [PMID: 27515511 PMCID: PMC5175349 DOI: 10.1093/nar/gkw707] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 08/01/2016] [Accepted: 08/02/2016] [Indexed: 02/07/2023] Open
Abstract
We describe the development of ‘recCas9’, an RNA-programmed small serine recombinase that functions in mammalian cells. We fused a catalytically inactive dCas9 to the catalytic domain of Gin recombinase using an optimized fusion architecture. The resulting recCas9 system recombines DNA sites containing a minimal recombinase core site flanked by guide RNA-specified sequences. We show that these recombinases can operate on DNA sites in mammalian cells identical to genomic loci naturally found in the human genome in a manner that is dependent on the guide RNA sequences. DNA sequencing reveals that recCas9 catalyzes guide RNA-dependent recombination in human cells with an efficiency as high as 32% on plasmid substrates. Finally, we demonstrate that recCas9 expressed in human cells can catalyze in situ deletion between two genomic sites. Because recCas9 directly catalyzes recombination, it generates virtually no detectable indels or other stochastic DNA modification products. This work represents a step toward programmable, scarless genome editing in unmodified cells that is independent of endogenous cellular machinery or cell state. Current and future generations of recCas9 may facilitate targeted agricultural breeding, or the study and treatment of human genetic diseases.
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Affiliation(s)
- Brian Chaikind
- Department of Chemistry & Chemical Biology, Harvard University, Cambridge, MA 02138, USA.,Howard Hughes Medical institute, Harvard University, Cambridge, MA 02138 USA
| | - Jeffrey L Bessen
- Department of Chemistry & Chemical Biology, Harvard University, Cambridge, MA 02138, USA.,Howard Hughes Medical institute, Harvard University, Cambridge, MA 02138 USA
| | - David B Thompson
- Department of Chemistry & Chemical Biology, Harvard University, Cambridge, MA 02138, USA.,Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA 02138, USA
| | - Johnny H Hu
- Department of Chemistry & Chemical Biology, Harvard University, Cambridge, MA 02138, USA.,Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA 02138, USA
| | - David R Liu
- Department of Chemistry & Chemical Biology, Harvard University, Cambridge, MA 02138, USA .,Howard Hughes Medical institute, Harvard University, Cambridge, MA 02138 USA
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48
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Probing Mitosis by Manipulating the Interactions of Mitotic Regulator Proteins Using Rapamycin-Inducible Dimerization. Methods Mol Biol 2016; 1413:325-31. [PMID: 27193858 DOI: 10.1007/978-1-4939-3542-0_20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
Abstract
Inducible dimerization is a general approach to experimentally manipulate protein-protein interactions with temporal control. This chapter describes the use of rapamycin-inducible dimerization to manipulate mitotic regulatory proteins, for example to control kinetochore localization. A significant feature of this method relative to previously described protocols is the depletion of endogenous FKBP12 protein, which markedly improves dimerization efficiency.
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49
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Moritz B, Woltering L, Becker PB, Göpfert U. High levels of histone H3 acetylation at the CMV promoter are predictive of stable expression in Chinese hamster ovary cells. Biotechnol Prog 2016; 32:776-86. [DOI: 10.1002/btpr.2271] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 03/11/2016] [Indexed: 12/12/2022]
Affiliation(s)
- Benjamin Moritz
- Roche Pharmaceutical Research and Early Development, Large Molecule Research, Roche Innovation Center Munich; Germany
- Biomedical Center and Center for Integrated Protein Science, Molecular Biology Division, Ludwig-Maximilians-University; Munich Germany
| | - Laura Woltering
- Roche Pharmaceutical Research and Early Development, Large Molecule Research, Roche Innovation Center Munich; Germany
| | - Peter B. Becker
- Biomedical Center and Center for Integrated Protein Science, Molecular Biology Division, Ludwig-Maximilians-University; Munich Germany
| | - Ulrich Göpfert
- Roche Pharmaceutical Research and Early Development, Large Molecule Research, Roche Innovation Center Munich; Germany
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50
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Mariscal AM, González-González L, Querol E, Piñol J. All-in-one construct for genome engineering using Cre-lox technology. DNA Res 2016; 23:263-70. [PMID: 27084897 PMCID: PMC4909314 DOI: 10.1093/dnares/dsw015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 03/02/2016] [Indexed: 12/25/2022] Open
Abstract
Mycoplasma genitalium is an appealing model of a minimal cell and synthetic biology study, and it was one of the first organisms whose genome was fully sequenced and chemically synthesized. Despite its usefulness as a model organism, many genetic tools well established for other microorganisms are not currently available in mycoplasmas. We have developed several vectors to adapt the Cre-lox technology for genome engineering in M. genitalium, providing an all-in-one construct that could be also useful to obtain unmarked genetic modifications in many other slow growing microorganisms. This construct contains a modified promoter sequence based in TetR system that exhibits an enhanced control on Cre recombinase expression, virtually abolishing the presence of this recombinase in the absence of inducer. This allows to introduce the Cre recombinase gene and the desired genetic modification in a single transformation step. In addition, this inducible promoter may be a very promising tool for a wide range of molecular applications.
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Affiliation(s)
- Ana M Mariscal
- Departament de Bioquímica i Biologia Molecular and Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 0819, Spain
| | - Luis González-González
- Departament de Bioquímica i Biologia Molecular and Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 0819, Spain
| | - Enrique Querol
- Departament de Bioquímica i Biologia Molecular and Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 0819, Spain
| | - Jaume Piñol
- Departament de Bioquímica i Biologia Molecular and Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 0819, Spain
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