1
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Hew BE, Gupta S, Sato R, Waller DF, Stoytchev I, Short JE, Sharek L, Tran CT, Badran AH, Owens JB. Directed evolution of hyperactive integrases for site specific insertion of transgenes. Nucleic Acids Res 2024:gkae534. [PMID: 38953167 DOI: 10.1093/nar/gkae534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 05/16/2024] [Accepted: 06/10/2024] [Indexed: 07/03/2024] Open
Abstract
The ability to deliver large transgenes to a single genomic sequence with high efficiency would accelerate biomedical interventions. Current methods suffer from low insertion efficiency and most rely on undesired double-strand DNA breaks. Serine integrases catalyze the insertion of large DNA cargos at attachment (att) sites. By targeting att sites to the genome using technologies such as prime editing, integrases can target safe loci while avoiding double-strand breaks. We developed a method of phage-assisted continuous evolution we call IntePACE, that we used to rapidly perform hundreds of rounds of mutagenesis to systematically improve activity of PhiC31 and Bxb1 serine integrases. Novel hyperactive mutants were generated by combining synergistic mutations resulting in integration of a multi-gene cargo at rates as high as 80% of target chromosomes. Hyperactive integrases inserted a 15.7 kb therapeutic DNA cargo containing von Willebrand Factor. This technology could accelerate gene delivery therapeutics and our directed evolution strategy can easily be adapted to improve novel integrases from nature.
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Affiliation(s)
- Brian E Hew
- Department of Cell and Molecular Biology, Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI 96814, USA
| | - Sabranth Gupta
- Department of Cell and Molecular Biology, Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI 96814, USA
| | - Ryuei Sato
- Department of Cell and Molecular Biology, Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI 96814, USA
| | - David F Waller
- Department of Cell and Molecular Biology, Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI 96814, USA
| | - Ilko Stoytchev
- Department of Cell and Molecular Biology, Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI 96814, USA
| | - James E Short
- Department of Cell and Molecular Biology, Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI 96814, USA
| | - Lisa Sharek
- Department of Cell and Molecular Biology, Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI 96814, USA
| | - Christopher T Tran
- Department of Cell and Molecular Biology, Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI 96814, USA
| | - Ahmed H Badran
- Department of Chemistry, Department of Integrative Structural and Computational Biology, Beckman Center for Chemical Sciences, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jesse B Owens
- Department of Cell and Molecular Biology, Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI 96814, USA
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2
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Erhardt V, Snow CM, Hosur V. Protocol for large DNA transgenesis in mice using the Cas9+Bxb1 toolbox. STAR Protoc 2024; 5:103022. [PMID: 38625797 PMCID: PMC11033688 DOI: 10.1016/j.xpro.2024.103022] [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: 12/22/2023] [Revised: 02/22/2024] [Accepted: 04/01/2024] [Indexed: 04/18/2024] Open
Abstract
Precise integration of DNA constructs greater than 3 kb into mouse zygotes is difficult. Here, we present a protocol for large DNA transgenesis in mice using the Cas9+Bxb1 toolbox. We describe steps for choosing mouse strains with preplaced attachment sites. We then detail procedures for microinjecting mouse zygotes with the plasmid donor DNA construct to generate transgenic mice by recombination-mediated cassette exchange. This protocol has the potential for application in exploring the functional implications of large structural variations in cancer. For complete details on the use and execution of this protocol, please refer to Low et al.1 and Hosur et al.2.
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Affiliation(s)
- Valerie Erhardt
- The Jackson Laboratory for Mammalian Genetics, Bar Harbor, ME, USA
| | - Chrystal M Snow
- The Jackson Laboratory for Mammalian Genetics, Bar Harbor, ME, USA
| | - Vishnu Hosur
- The Jackson Laboratory for Mammalian Genetics, Bar Harbor, ME, USA.
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3
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Erhardt V, Hartig E, Lorenzo K, Megathlin HR, Tarchini B, Hosur V. Large-Scale Genome-Wide Optimization and Prediction of the Cre Recombinase System for Precise Genome Manipulation in Mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.14.599022. [PMID: 38948742 PMCID: PMC11212873 DOI: 10.1101/2024.06.14.599022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
The Cre-Lox recombination system is a powerful tool in mouse genetics, offering spatial-temporal control over gene expression and facilitating the large-scale generation of conditional knockout mice. Its versatility also extends to other research models, such as rats, pigs, and zebrafish. However, the Cre-Lox technology presents a set of challenges that includes high costs, a time-intensive process, and the occurrence of unpredictable recombination events, which can lead to unexpected phenotypic outcomes. To better understand factors affecting recombination, we embarked on a systematic and genome-wide analysis of Cre-mediated recombination in mice. To ensure uniformity and reproducibility, we generated 11 novel strains with conditional alleles at the ROSA26 locus, utilizing a single inbred mouse strain background, C57BL/6J. We examined several factors influencing Cre-recombination, including the inter-loxP distance, mutant loxP sites, the zygosity of the conditional alleles, chromosomal location, and the age of the breeders. We discovered that the selection of the Cre-driver strain profoundly impacts recombination efficiency. We also found that successful and complete recombination is best achieved when loxP sites are spaced between 1 to 4 kb apart, with mutant loxP sites facilitating recombination at distances of 1 to 3 kb. Furthermore, we demonstrate that complete recombination does not occur at an inter-loxP distance of ≥ 15 kb with wildtype loxP sites, nor at a distance of ≥ 7 kb with mutant lox71/66 sites. Interestingly, the age of the Cre-driver mouse at the time of breeding emerged as a critical factor in recombination efficiency, with best results observed between 8 and 20 weeks old. Moreover, crossing heterozygous floxed alleles with the Cre-driver strain resulted in more efficient recombination than using homozygous floxed alleles. Lastly, maintaining an inter-loxP distance of 4 kb or less ensures efficient recombination of the conditional allele, regardless of the chromosomal location. While CRISPR/Cas has revolutionized genome editing in mice, Cre-Lox technology remains a cornerstone for the generation of sophisticated alleles and for precise control of gene expression in mice. The knowledge gained here will enable investigators to select a Cre-Lox approach that is most efficient for their desired outcome in the generation of both germline and non-germline mouse models of human disease, thereby reducing time and cost of Cre-Lox technology-mediated genome modification.
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Affiliation(s)
- Valerie Erhardt
- The Jackson Laboratory for Mammalian Genetics, Bar Harbor, ME
| | - Elli Hartig
- The Jackson Laboratory for Mammalian Genetics, Bar Harbor, ME
- Tufts University School of Medicine, Boston, MA
| | - Kristian Lorenzo
- The Jackson Laboratory for Mammalian Genetics, Bar Harbor, ME
- The Roux Institute at Northeastern University, Portland, ME
| | - Hannah R Megathlin
- The Jackson Laboratory for Mammalian Genetics, Bar Harbor, ME
- Graduate School of Biomedical Sciences and Engineering, UMaine, Orono, ME
| | - Basile Tarchini
- The Jackson Laboratory for Mammalian Genetics, Bar Harbor, ME
- Tufts University School of Medicine, Boston, MA
| | - Vishnu Hosur
- The Jackson Laboratory for Mammalian Genetics, Bar Harbor, ME
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4
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Hew BE, Gupta S, Sato R, Waller DF, Stoytchev I, Short JE, Sharek L, Tran CT, Badran AH, Owens JB. Directed evolution of hyperactive integrases for site specific insertion of transgenes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.10.598370. [PMID: 38915697 PMCID: PMC11195097 DOI: 10.1101/2024.06.10.598370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
The ability to deliver large transgenes to a single genomic sequence with high efficiency would accelerate biomedical interventions. Current methods suffer from low insertion efficiency and most rely on undesired double-strand DNA breaks. Serine integrases catalyze the insertion of large DNA cargos at attachment (att) sites. By targeting att sites to the genome using technologies such as prime editing, integrases can target safe loci while avoiding double-strand breaks. We developed a method of phage-assisted continuous evolution we call IntePACE, that we used to rapidly perform hundreds of rounds of mutagenesis to systematically improve activity of PhiC31 and Bxb1 serine integrases. Novel hyperactive mutants were generated by combining synergistic mutations resulting in integration of a multi-gene cargo at rates as high as 80% of target chromosomes. Hyperactive integrases inserted a 15.7 kb therapeutic DNA cargo containing Von Willebrand Factor. This technology could accelerate gene delivery therapeutics and our directed evolution strategy can easily be adapted to improve novel integrases from nature.
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Affiliation(s)
- Brian E. Hew
- Department of Cell and Molecular Biology, Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, Hawaii, 96814 USA
| | - Sabranth Gupta
- Department of Cell and Molecular Biology, Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, Hawaii, 96814 USA
| | - Ryuei Sato
- Department of Cell and Molecular Biology, Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, Hawaii, 96814 USA
| | - David F. Waller
- Department of Cell and Molecular Biology, Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, Hawaii, 96814 USA
| | - Ilko Stoytchev
- Department of Cell and Molecular Biology, Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, Hawaii, 96814 USA
| | - James E. Short
- Department of Cell and Molecular Biology, Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, Hawaii, 96814 USA
| | - Lisa Sharek
- Department of Cell and Molecular Biology, Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, Hawaii, 96814 USA
| | - Christopher T. Tran
- Department of Cell and Molecular Biology, Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, Hawaii, 96814 USA
| | - Ahmed H. Badran
- Department of Chemistry, Department of Integrative Structural and Computational Biology, Beckman Center for Chemical Sciences, The Scripps Research Institute, La Jolla, California, 92037 USA
| | - Jesse B. Owens
- Department of Cell and Molecular Biology, Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, Hawaii, 96814 USA
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5
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Zhang X, Van Treeck B, Horton CA, McIntyre JJR, Palm SM, Shumate JL, Collins K. Harnessing eukaryotic retroelement proteins for transgene insertion into human safe-harbor loci. Nat Biotechnol 2024:10.1038/s41587-024-02137-y. [PMID: 38379101 DOI: 10.1038/s41587-024-02137-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 01/10/2024] [Indexed: 02/22/2024]
Abstract
Current approaches for inserting autonomous transgenes into the genome, such as CRISPR-Cas9 or virus-based strategies, have limitations including low efficiency and high risk of untargeted genome mutagenesis. Here, we describe precise RNA-mediated insertion of transgenes (PRINT), an approach for site-specifically primed reverse transcription that directs transgene synthesis directly into the genome at a multicopy safe-harbor locus. PRINT uses delivery of two in vitro transcribed RNAs: messenger RNA encoding avian R2 retroelement-protein and template RNA encoding a transgene of length validated up to 4 kb. The R2 protein coordinately recognizes the target site, nicks one strand at a precise location and primes complementary DNA synthesis for stable transgene insertion. With a cultured human primary cell line, over 50% of cells can gain several 2 kb transgenes, of which more than 50% are full-length. PRINT advantages include no extragenomic DNA, limiting risk of deleterious mutagenesis and innate immune responses, and the relatively low cost, rapid production and scalability of RNA-only delivery.
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Affiliation(s)
- Xiaozhu Zhang
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA, USA
| | - Briana Van Treeck
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA, USA
| | - Connor A Horton
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA, USA
| | - Jeremy J R McIntyre
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA, USA
| | - Sarah M Palm
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA, USA
| | - Justin L Shumate
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA, USA
| | - Kathleen Collins
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA, USA.
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6
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Bloom BR. A half-century of research on tuberculosis: Successes and challenges. J Exp Med 2023; 220:e20230859. [PMID: 37552470 PMCID: PMC10407785 DOI: 10.1084/jem.20230859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 07/20/2023] [Accepted: 07/21/2023] [Indexed: 08/09/2023] Open
Abstract
Great progress has been made over the past half-century, but TB remains a formidable global health problem, particularly in low- and middle-income countries. Understanding the mechanisms of pathogenesis and necessary and sufficient conditions for protection are critical. The need for inexpensive and sensitive point-of-care diagnostic tests for earlier detection of infection and disease, shorter and less-toxic drug regimens for drug-sensitive and -resistant TB, and a more effective vaccine than BCG is immense. New and better tools, greater support for international research, collaborations, and training will be required to dramatically reduce the burden of this devastating disease which still kills 1.6 million people annually.
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Affiliation(s)
- Barry R. Bloom
- Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
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7
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Popovitz J, Sharma R, Hoshyar R, Soo Kim B, Murthy N, Lee K. Gene editing therapeutics based on mRNA delivery. Adv Drug Deliv Rev 2023; 200:115026. [PMID: 37516409 DOI: 10.1016/j.addr.2023.115026] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 07/20/2023] [Accepted: 07/26/2023] [Indexed: 07/31/2023]
Abstract
The field of gene editing has received much attention in recent years due to its immense therapeutic potential. In particular, gene editing therapeutics, such as the CRISPR-Cas systems, base editors, and other emerging gene editors, offer the opportunity to address previously untreatable disorders. This review aims to summarize the therapeutic applications of gene editing based on mRNA delivery. We introduce gene editing therapeutics using mRNA and focus on engineering and improvement of gene editing technology. We subsequently examine ex vivo and in vivo gene editing techniques and conclude with an exploration of the next generation of CRISPR and base editing systems.
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Affiliation(s)
| | - Rohit Sharma
- Department of Bioengineering, University of California, Berkeley, CA 94720, USA; Innovative Genomics Institute, 2151 Berkeley Way, Berkeley, CA 94704, USA
| | - Reyhane Hoshyar
- GenEdit, 681 Gateway Blvd., South San Francisco, CA 94080, USA
| | - Beob Soo Kim
- GenEdit, 681 Gateway Blvd., South San Francisco, CA 94080, USA
| | - Niren Murthy
- Department of Bioengineering, University of California, Berkeley, CA 94720, USA; Innovative Genomics Institute, 2151 Berkeley Way, Berkeley, CA 94704, USA.
| | - Kunwoo Lee
- GenEdit, 681 Gateway Blvd., South San Francisco, CA 94080, USA.
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8
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Brooks PJ, Urv TK, Parisi MA. Gene-targeted therapies: Overview and implications. AMERICAN JOURNAL OF MEDICAL GENETICS. PART C, SEMINARS IN MEDICAL GENETICS 2023; 193:13-18. [PMID: 36864710 DOI: 10.1002/ajmg.c.32033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 01/10/2023] [Accepted: 01/11/2023] [Indexed: 03/04/2023]
Abstract
Gene-targeted therapies (GTTs) are therapeutic platforms that are in principle applicable to large numbers of monogenic diseases. The rapid development and implementation of GTTs have profound implications for rare monogenic disease therapy development. This article provides a brief summary of the primary types of GTTs and a brief overview of the current state of the science. It also serves as a primer for the articles in this special issue.
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Affiliation(s)
- P J Brooks
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, Maryland, USA
| | - Tiina K Urv
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, Maryland, USA
| | - Melissa A Parisi
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
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9
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Palmer RD. Three Tiers to biological escape velocity: The quest to outwit aging. Aging Med (Milton) 2022; 5:281-286. [PMID: 36606268 PMCID: PMC9805293 DOI: 10.1002/agm2.12231] [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: 08/10/2022] [Revised: 11/14/2022] [Accepted: 11/20/2022] [Indexed: 12/14/2022] Open
Abstract
As longevity companies emerge with new products and the fields of anti-aging research develop new cutting-edge therapies, three distinct classes of longevity methodologies emerge. This discussion finds that there are three clear classes (Tiers) of longevity systems that are currently under development, and all three will be paramount to achieve biological escape velocity (where tissues can be repaired faster than aging can damage them). These classes are referred to as Tier 1, Tier 2, and Tier 3 treatments and are described in detail below. These three Tiers are required for easy identification for pharmaceutical companies and research companies to determine the type of therapy they may choose to deliver being noninvasive, invasive, time consuming, or simple end user products. Specific targets and goals need to be defined clearly from an early perspective in the development of these technologies for future precision medicines. This allows consumers of future anti-aging technologies to consider which Tier a particular therapy may be, delivering a more informed choice.
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Affiliation(s)
- Raymond D. Palmer
- Full Spectrum BiologicsSouth PerthWestern AustraliaAustralia,School of Aging, Science of AgingSouth PerthWestern AustraliaAustralia
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