1
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Catalán-Tatjer D, Tzimou K, Nielsen LK, Lavado-García J. Unravelling the essential elements for recombinant adeno-associated virus (rAAV) production in animal cell-based platforms. Biotechnol Adv 2024; 73:108370. [PMID: 38692443 DOI: 10.1016/j.biotechadv.2024.108370] [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: 01/16/2024] [Revised: 04/05/2024] [Accepted: 04/27/2024] [Indexed: 05/03/2024]
Abstract
Recombinant adeno-associated viruses (rAAVs) stand at the forefront of gene therapy applications, holding immense significance for their safe and efficient gene delivery capabilities. The constantly increasing and unmet demand for rAAVs underscores the need for a more comprehensive understanding of AAV biology and its impact on rAAV production. In this literature review, we delved into AAV biology and rAAV manufacturing bioprocesses, unravelling the functions and essentiality of proteins involved in rAAV production. We discuss the interconnections between these proteins and how they affect the choice of rAAV production platform. By addressing existing inconsistencies, literature gaps and limitations, this review aims to define a minimal set of genes that are essential for rAAV production, providing the potential to advance rAAV biomanufacturing, with a focus on minimizing the genetic load within rAAV-producing cells.
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Affiliation(s)
- David Catalán-Tatjer
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Denmark
| | - Konstantina Tzimou
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Denmark
| | - Lars K Nielsen
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Denmark; Australian Institute for Bioengineering and Nanotechnology, University of Queensland, Australia
| | - Jesús Lavado-García
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Denmark.
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2
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Luo Z, Chen Y. Unlocking Delivery Strategies for mRNA Therapeutics. Recent Pat Anticancer Drug Discov 2024; 19:126-129. [PMID: 37287306 DOI: 10.2174/1574892818666230607093231] [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: 12/05/2022] [Revised: 03/01/2023] [Accepted: 05/16/2023] [Indexed: 06/09/2023]
Abstract
mRNA emerged as an attractive therapy modality with the development of mRNA structure engineering techniques and delivery platforms. mRNA therapeutics, applied for vaccine therapy, protein replacement therapy, and chimeric antigen receptor (CAR) T cell-based therapy, has shown huge potential in treating a wide range of diseases, such as cancer and rare genetic diseases, with successful and exciting preclinical and clinical progress. In mRNA therapeutics, a potent delivery system is key to the success of its application for disease treatment. Herein, different types of mRNA delivery strategies, including nanoparticles produced from lipid or polymer materials, virus-based platforms, and exosome-based platforms, are mainly focused.
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Affiliation(s)
- Zhiyuan Luo
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong
| | - Yangchao Chen
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong
- Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
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3
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Zhang S, Wang Y, Mao D, Wang Y, Zhang H, Pan Y, Wang Y, Teng S, Huang P. Current trends of clinical trials involving CRISPR/Cas systems. Front Med (Lausanne) 2023; 10:1292452. [PMID: 38020120 PMCID: PMC10666174 DOI: 10.3389/fmed.2023.1292452] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 10/25/2023] [Indexed: 12/01/2023] Open
Abstract
The CRISPR/Cas9 system is a powerful genome editing tool that has made enormous impacts on next-generation molecular diagnostics and therapeutics, especially for genetic disorders that traditional therapies cannot cure. Currently, CRISPR-based gene editing is widely applied in basic, preclinical, and clinical studies. In this review, we attempt to identify trends in clinical studies involving CRISPR techniques to gain insights into the improvement and contribution of CRISPR/Cas technologies compared to traditional modified modalities. The review of clinical trials is focused on the applications of the CRISPR/Cas systems in the treatment of cancer, hematological, endocrine, and immune system diseases, as well as in diagnostics. The scientific basis underlined is analyzed. In addition, the challenges of CRISPR application in disease therapies and recent advances that expand and improve CRISPR applications in precision medicine are discussed.
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Affiliation(s)
- Songyang Zhang
- The Key Laboratory of Pathobiology, Ministry of Education, Norman Bethune College of Medicine, Jilin University, Changchun, China
| | - Yidi Wang
- The Third Affiliated Hospital of Jilin University, Changchun, China
| | - Dezhi Mao
- The Third Affiliated Hospital of Jilin University, Changchun, China
| | - Yue Wang
- The Second Affiliated Hospital of Jilin University, Changchun, China
| | - Hong Zhang
- The Third Affiliated Hospital of Jilin University, Changchun, China
| | - Yihan Pan
- The Second Affiliated Hospital of Jilin University, Changchun, China
| | - Yuezeng Wang
- The Key Laboratory of Pathobiology, Ministry of Education, Norman Bethune College of Medicine, Jilin University, Changchun, China
| | - Shuzhi Teng
- The Key Laboratory of Pathobiology, Ministry of Education, Norman Bethune College of Medicine, Jilin University, Changchun, China
| | - Ping Huang
- The Key Laboratory of Pathobiology, Ministry of Education, Norman Bethune College of Medicine, Jilin University, Changchun, China
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4
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Ishibashi Y, Sung CYW, Grati M, Chien W. Immune responses in the mammalian inner ear and their implications for AAV-mediated inner ear gene therapy. Hear Res 2023; 432:108735. [PMID: 36965335 DOI: 10.1016/j.heares.2023.108735] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 02/17/2023] [Accepted: 03/04/2023] [Indexed: 03/13/2023]
Abstract
Adeno-associated virus (AAV)-mediated inner ear gene therapy is a promising treatment option for hearing loss and dizziness. Several studies have shown that AAV-mediated inner ear gene therapy can be applied to various mouse models of hereditary hearing loss to improve their auditory function. Despite the increase in AAV-based animal and clinical studies aiming to rescue auditory and vestibular functions, little is currently known about the host immune responses to AAV in the mammalian inner ear. It has been reported that the host immune response plays an important role in the safety and efficacy of viral-mediated gene therapy. Therefore, in order for AAV-mediated gene therapy to be successfully and safely translated into patients with hearing loss and dizziness, a better understanding of the host immune responses to AAV in the inner ear is critical. In this review, we summarize the current knowledge on host immune responses to AAV-mediated gene therapy in the mammalian inner ear and other organ systems. We also outline the areas of research that are critical for ensuring the safety and efficacy of AAV-mediated inner ear gene therapy in future clinical and translational studies.
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Affiliation(s)
- Yasuko Ishibashi
- Inner Ear Gene Therapy Program, National Institute on Deafness and Other Communication Disorders (NIDCD), National Institutes of Health, 35A 1F220, 35A Covent Dr., Bethesda, MD 20892, USA; Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders (NIDCD), National Institutes of Health, Bethesda, MD, USA
| | - Cathy Yea Won Sung
- Laboratory of Hearing Biology and Therapeutics, National Institute on Deafness and Other Communication Disorders (NIDCD), National Institutes of Health, Bethesda, MD, USA
| | - Mhamed Grati
- Inner Ear Gene Therapy Program, National Institute on Deafness and Other Communication Disorders (NIDCD), National Institutes of Health, 35A 1F220, 35A Covent Dr., Bethesda, MD 20892, USA
| | - Wade Chien
- Inner Ear Gene Therapy Program, National Institute on Deafness and Other Communication Disorders (NIDCD), National Institutes of Health, 35A 1F220, 35A Covent Dr., Bethesda, MD 20892, USA; Department of Otolaryngology-Head & Neck Surgery, Johns Hopkins School of Medicine, Baltimore, MD, USA.
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5
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Bhujbal S, Bhujbal R, Giram P. An overview: CRISPR/Cas-based gene editing for viral vaccine development. Expert Rev Vaccines 2022; 21:1581-1593. [PMID: 35959589 DOI: 10.1080/14760584.2022.2112952] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION : Gene-editing technology revolutionized vaccine manufacturing and offers a variety of benefits over traditional vaccinations, such as improved immune response, higher production rate, stability, precise immunogenic activity, and fewer adverse effects. The more recently discovered Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/associated protein 9 (Cas9) system has become the most widely utilized technology based on its efficiency, utility, flexibility, versatility, ease of use, and cheaper compared to other gene-editing techniques. Considering its wider scope for genomic modification, CRISPR/Cas9-based technology's potential is explored for vaccine development. AREAS COVERED : In this review, we will address the recent advances in the CRISPR/Cas system for the development of vaccines and viral vectors for delivery. In addition, we will discuss strategies for the development of the vaccine, as well as the limitations and future prospects of the CRISPR/Cas system. EXPERT OPINION : Human and animal viruses have been exposed to antiviral CRISPR/Cas9-based engineering to prevent infection, which uses knockout, knock-in, gene activation/deactivation, RNA targeting, and editing cell lines strategies for gene editing of viruses. Because of that CRISPR/Cas system is used to boost the vaccine production yield by removing unwanted genes that cause disease or are required for viral infection.
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Affiliation(s)
- Santosh Bhujbal
- Department of Pharmacognosy, Dr. D. Y. Patil Institute of Pharmaceutical Sciences and Research, Sant. Tukaram Nagar Pimpri, Pune, Maharashtra (India) -411018
| | - Rushikesh Bhujbal
- Department of Quality Assurance Technique, Dr. D. Y. Patil Institute of Pharmaceutical Sciences and Research, Sant. Tukaram Nagar Pimpri, Pune, Maharashtra (India) -411018
| | - Prabhanjan Giram
- Department of Pharmaceutics, Dr. D. Y. Patil Institute of Pharmaceutical Sciences and Research, Sant. Tukaram Nagar Pimpri, Pune, Maharashtra (India) -411018.,Department of Pharmaceutics, Department of Pharmaceutical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA- 14260-1660
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6
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Huerlimann R, Cowley JA, Wade NM, Wang Y, Kasinadhuni N, Chan CKK, Jabbari JS, Siemering K, Gordon L, Tinning M, Montenegro JD, Maes GE, Sellars MJ, Coman GJ, McWilliam S, Zenger KR, Khatkar MS, Raadsma HW, Donovan D, Krishna G, Jerry DR. Genome assembly of the Australian black tiger shrimp (Penaeus monodon) reveals a novel fragmented IHHNV EVE sequence. G3 (BETHESDA, MD.) 2022; 12:6526390. [PMID: 35143647 PMCID: PMC8982415 DOI: 10.1093/g3journal/jkac034] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 02/02/2022] [Indexed: 01/08/2023]
Abstract
Shrimp are a valuable aquaculture species globally; however, disease remains a major hindrance to shrimp aquaculture sustainability and growth. Mechanisms mediated by endogenous viral elements have been proposed as a means by which shrimp that encounter a new virus start to accommodate rather than succumb to infection over time. However, evidence on the nature of such endogenous viral elements and how they mediate viral accommodation is limited. More extensive genomic data on Penaeid shrimp from different geographical locations should assist in exposing the diversity of endogenous viral elements. In this context, reported here is a PacBio Sequel-based draft genome assembly of an Australian black tiger shrimp (Penaeus monodon) inbred for 1 generation. The 1.89 Gbp draft genome is comprised of 31,922 scaffolds (N50: 496,398 bp) covering 85.9% of the projected genome size. The genome repeat content (61.8% with 30% representing simple sequence repeats) is almost the highest identified for any species. The functional annotation identified 35,517 gene models, of which 25,809 were protein-coding and 17,158 were annotated using interproscan. Scaffold scanning for specific endogenous viral elements identified an element comprised of a 9,045-bp stretch of repeated, inverted, and jumbled genome fragments of infectious hypodermal and hematopoietic necrosis virus bounded by a repeated 591/590 bp host sequence. As only near complete linear ∼4 kb infectious hypodermal and hematopoietic necrosis virus genomes have been found integrated in the genome of P. monodon previously, its discovery has implications regarding the validity of PCR tests designed to specifically detect such linear endogenous viral element types. The existence of joined inverted infectious hypodermal and hematopoietic necrosis virus genome fragments also provides a means by which hairpin double-stranded RNA could be expressed and processed by the shrimp RNA interference machinery.
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Affiliation(s)
- Roger Huerlimann
- ARC Industrial Transformation Research Hub for Advanced Prawn Breeding, James Cook University, Townsville, QLD 4811, Australia.,Centre for Sustainable Tropical Fisheries and Aquaculture, College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia.,Centre for Tropical Bioinformatics and Molecular Biology, James Cook University, Townsville, QLD 4811, Australia
| | - Jeff A Cowley
- ARC Industrial Transformation Research Hub for Advanced Prawn Breeding, James Cook University, Townsville, QLD 4811, Australia.,CSIRO Agriculture and Food, St Lucia, QLD 4067, Australia
| | - Nicholas M Wade
- ARC Industrial Transformation Research Hub for Advanced Prawn Breeding, James Cook University, Townsville, QLD 4811, Australia.,CSIRO Agriculture and Food, St Lucia, QLD 4067, Australia
| | - Yinan Wang
- Australian Genome Research Facility Ltd, Level 13, Victorian Comprehensive Cancer Centre, Melbourne, VIC 3000, Australia
| | - Naga Kasinadhuni
- Australian Genome Research Facility Ltd, Level 13, Victorian Comprehensive Cancer Centre, Melbourne, VIC 3000, Australia
| | - Chon-Kit Kenneth Chan
- Australian Genome Research Facility Ltd, Level 13, Victorian Comprehensive Cancer Centre, Melbourne, VIC 3000, Australia
| | - Jafar S Jabbari
- Australian Genome Research Facility Ltd, Level 13, Victorian Comprehensive Cancer Centre, Melbourne, VIC 3000, Australia
| | - Kirby Siemering
- ARC Industrial Transformation Research Hub for Advanced Prawn Breeding, James Cook University, Townsville, QLD 4811, Australia.,Australian Genome Research Facility Ltd, Level 13, Victorian Comprehensive Cancer Centre, Melbourne, VIC 3000, Australia
| | - Lavinia Gordon
- Australian Genome Research Facility Ltd, Level 13, Victorian Comprehensive Cancer Centre, Melbourne, VIC 3000, Australia
| | - Matthew Tinning
- ARC Industrial Transformation Research Hub for Advanced Prawn Breeding, James Cook University, Townsville, QLD 4811, Australia.,Australian Genome Research Facility Ltd, Level 13, Victorian Comprehensive Cancer Centre, Melbourne, VIC 3000, Australia
| | - Juan D Montenegro
- Australian Genome Research Facility Ltd, Level 13, Victorian Comprehensive Cancer Centre, Melbourne, VIC 3000, Australia
| | - Gregory E Maes
- Centre for Sustainable Tropical Fisheries and Aquaculture, College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia.,Laboratory of Biodiversity and Evolutionary Genomics, Biogenomics-consultancy, KU Leuven, Leuven 3000, Belgium.,Center for Human Genetics, UZ Leuven- Genomics Core, KU Leuven, Leuven 3000, Belgium
| | | | - Greg J Coman
- ARC Industrial Transformation Research Hub for Advanced Prawn Breeding, James Cook University, Townsville, QLD 4811, Australia.,CSIRO Agriculture and Food, Bribie Island Research Centre, Woorim, QLD 4507, Australia
| | - Sean McWilliam
- ARC Industrial Transformation Research Hub for Advanced Prawn Breeding, James Cook University, Townsville, QLD 4811, Australia.,CSIRO Agriculture and Food, St Lucia, QLD 4067, Australia
| | - Kyall R Zenger
- ARC Industrial Transformation Research Hub for Advanced Prawn Breeding, James Cook University, Townsville, QLD 4811, Australia.,Centre for Sustainable Tropical Fisheries and Aquaculture, College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia
| | - Mehar S Khatkar
- ARC Industrial Transformation Research Hub for Advanced Prawn Breeding, James Cook University, Townsville, QLD 4811, Australia.,Faculty of Science, Sydney School of Veterinary Science, The University of Sydney, Camden, NSW 2570, Australia
| | - Herman W Raadsma
- ARC Industrial Transformation Research Hub for Advanced Prawn Breeding, James Cook University, Townsville, QLD 4811, Australia.,Faculty of Science, Sydney School of Veterinary Science, The University of Sydney, Camden, NSW 2570, Australia
| | - Dallas Donovan
- ARC Industrial Transformation Research Hub for Advanced Prawn Breeding, James Cook University, Townsville, QLD 4811, Australia.,Seafarms Group Ltd, Darwin, NT 0800, Australia
| | - Gopala Krishna
- ARC Industrial Transformation Research Hub for Advanced Prawn Breeding, James Cook University, Townsville, QLD 4811, Australia.,Seafarms Group Ltd, Darwin, NT 0800, Australia
| | - Dean R Jerry
- ARC Industrial Transformation Research Hub for Advanced Prawn Breeding, James Cook University, Townsville, QLD 4811, Australia.,Centre for Sustainable Tropical Fisheries and Aquaculture, College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia.,Centre for Tropical Bioinformatics and Molecular Biology, James Cook University, Townsville, QLD 4811, Australia
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7
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Riyad JM, Weber T. Intracellular trafficking of adeno-associated virus (AAV) vectors: challenges and future directions. Gene Ther 2021; 28:683-696. [PMID: 33658649 PMCID: PMC8413391 DOI: 10.1038/s41434-021-00243-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 01/27/2021] [Accepted: 02/05/2021] [Indexed: 02/07/2023]
Abstract
In the last two decades, recombinant adeno-associated virus has emerged as the most popular gene therapy vector. Recently AAV gene therapy has been approved by the FDA for the treatment of two rare genetic disorders, namely the early childhood blindness disease Leber congenital amaurosis and spinal muscular atrophy (SMA). As is the case for the treatment of SMA, if the AAV vector must be administered systemically, very high vector doses are often required for therapeutic efficacy. But higher vector doses inevitably increase the risk of adverse events. The tragic death of three children in a clinical trial to treat X-linked myotubular myopathy with an AAV vector has thrown this limitation into sharp relief. Regardless of the precise cause(s) that led to the death of the two children, it is critical that we develop better AAV vectors to achieve therapeutic levels of expression with lower vector doses. To transduce successfully a target cell, AAV has to overcome both systemic as well as cellular roadblocks. In this review, we discuss some of the most prominent cellular roadblocks that AAV must get past to deliver successfully its therapeutic payload. We also highlight recent advancements in our knowledge of AAV biology that can potentially be harnessed to improve AAV vector performance and thereby make AAV gene therapy safer.
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Affiliation(s)
- Jalish M Riyad
- Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Thomas Weber
- Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
- Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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8
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Boftsi M, Whittle FB, Wang J, Shepherd P, Burger LR, Kaifer KA, Lorson CL, Joshi T, Pintel DJ, Majumder K. The adeno-associated virus 2 (AAV2) genome and rep 68/78 proteins interact with cellular sites of DNA damage. Hum Mol Genet 2021; 31:985-998. [PMID: 34652429 DOI: 10.1093/hmg/ddab300] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 09/20/2021] [Accepted: 10/11/2021] [Indexed: 12/14/2022] Open
Abstract
Nuclear DNA viruses simultaneously access cellular factors that aid their life cycle while evading inhibitory factors by localizing to distinct nuclear sites. Adeno-Associated Viruses (AAVs), which are Dependoviruses in the family Parvovirinae, are non-enveloped icosahedral viruses, that have been developed as recombinant AAV vectors (rAAV) to express transgenes. AAV2 expression and replication occur in nuclear viral replication centers (VRCs), which relies on cellular replication machinery as well as coinfection by helper viruses such as adenoviruses or herpesviruses, or exogenous DNA damage to host cells. AAV2 infection induces a complex cellular DNA damage response (DDR), either in response to viral DNA or viral proteins expressed in the host nucleus during infection, where VRCs colocalize with DDR proteins. We have previously developed a modified iteration of a viral chromosome conformation capture (V3C-seq) assay to show that the autonomous parvovirus Minute Virus of Mice (MVM) localizes to cellular sites of DNA damage to establish and amplify its replication. Similar V3C-seq assays to map AAV2 show that the AAV2 genome colocalized with cellular sites of DNA damage under both non-replicating and replicating conditions. The AAV2 non-structural protein Rep 68/78, also localized to cellular DDR sites during both non-replicating and replicating infections, and also when ectopically expressed. Ectopically expressed Rep could be efficiently re-localized to DDR sites induced by micro-irradiation. Recombinant AAV2 gene therapy vector genomes derived from AAV2 localized to sites of cellular DNA damage to a lesser degree, suggesting that the Inverted Terminal Repeat (ITR) origins of replication were insufficient for targeting.
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Affiliation(s)
- Maria Boftsi
- Pathobiology Area Graduate Program.,Christopher S. Bond Life Sciences Center
| | | | - Juexin Wang
- Christopher S. Bond Life Sciences Center.,Department of Electrical Engineering and Computer Science
| | | | | | - Kevin A Kaifer
- Christopher S. Bond Life Sciences Center.,Department of Veterinary Pathobiology, College of Veterinary Medicine
| | - Christian L Lorson
- Christopher S. Bond Life Sciences Center.,Department of Veterinary Pathobiology, College of Veterinary Medicine
| | - Trupti Joshi
- Christopher S. Bond Life Sciences Center.,Department of Electrical Engineering and Computer Science.,MU Informatics Institute.,Department of Health Management and Informatics
| | - David J Pintel
- Christopher S. Bond Life Sciences Center.,Molecular Microbiology and Immunology, University of Missouri-Columbia, School of Medicine, Columbia, MO USA 65211
| | - Kinjal Majumder
- Institute for Molecular Virology.,McArdle Laboratory for Cancer Research.,University of Wisconsin-Carbone Cancer Center
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9
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Silva-Pilipich N, Smerdou C, Vanrell L. A Small Virus to Deliver Small Antibodies: New Targeted Therapies Based on AAV Delivery of Nanobodies. Microorganisms 2021; 9:microorganisms9091956. [PMID: 34576851 PMCID: PMC8465657 DOI: 10.3390/microorganisms9091956] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 09/04/2021] [Accepted: 09/07/2021] [Indexed: 12/12/2022] Open
Abstract
Nanobodies are camelid-derived single-domain antibodies that present some advantages versus conventional antibodies, such as a smaller size, and higher tissue penetrability, stability, and hydrophilicity. Although nanobodies can be delivered as proteins, in vivo expression from adeno-associated viral (AAV) vectors represents an attractive strategy. This is due to the fact that AAV vectors, that can provide long-term expression of recombinant genes, have shown an excellent safety profile, and can accommodate genes for one or several nanobodies. In fact, several studies showed that AAV vectors can provide sustained nanobody expression both locally or systemically in preclinical models of human diseases. Some of the pathologies addressed with this technology include cancer, neurological, cardiovascular, infectious, and genetic diseases. Depending on the indication, AAV-delivered nanobodies can be expressed extracellularly or inside cells. Intracellular nanobodies or “intrabodies” carry out their function by interacting with cell proteins involved in disease and have also been designed to help elucidate cellular mechanisms by interfering with normal cell processes. Finally, nanobodies can also be used to retarget AAV vectors, when tethered to viral capsid proteins. This review covers applications in which AAV vectors have been used to deliver nanobodies, with a focus on their therapeutic use.
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Affiliation(s)
- Noelia Silva-Pilipich
- Division of Gene Therapy and Regulation of Gene Expression, Cima Universidad de Navarra and Instituto de Investigación Sanitaria de Navarra (IdISNA), 31008 Pamplona, Spain;
| | - Cristian Smerdou
- Division of Gene Therapy and Regulation of Gene Expression, Cima Universidad de Navarra and Instituto de Investigación Sanitaria de Navarra (IdISNA), 31008 Pamplona, Spain;
- Correspondence: (C.S.); (L.V.); Tel.: +34-948194700 (C.S.); +508-29021505 (L.V.); Fax: +34-948194717 (C.S.)
| | - Lucía Vanrell
- Biotechnology Laboratory, Facultad de Ingeniería, Universidad ORT Uruguay, Mercedes 1237, Montevideo 11100, Uruguay
- Nanogrow Biotech, CIE BIO Incubator, Mercedes 1237, Montevideo 11100, Uruguay
- Correspondence: (C.S.); (L.V.); Tel.: +34-948194700 (C.S.); +508-29021505 (L.V.); Fax: +34-948194717 (C.S.)
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10
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The U94 Gene of Human Herpesvirus 6: A Narrative Review of Its Role and Potential Functions. Cells 2020; 9:cells9122608. [PMID: 33291793 PMCID: PMC7762089 DOI: 10.3390/cells9122608] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 12/02/2020] [Accepted: 12/02/2020] [Indexed: 12/11/2022] Open
Abstract
Human herpesvirus 6 (HHV-6) is a β-herpesvirus that is highly prevalent in the human population. HHV-6 comprises two recognized species (HHV-6A and HHV-6B). Despite different cell tropism and disease association, HHV-6A/B show high genome homology and harbor the conserved U94 gene, which is limited to HHV-6 and absent in all the other human herpesviruses. U94 has key functions in the virus life cycle and associated diseases, having demonstrated or putative roles in virus replication, integration, and reactivation. During natural infection, U94 elicits an immune response, and the prevalence and extent of the anti-U94 response are associated with specific diseases. Notably, U94 can entirely reproduce some virus effects at the cell level, including inhibition of cell migration, induction of cytokines and HLA-G expression, and angiogenesis inhibition, supporting a direct U94 role in the development of HHV-6-associated diseases. Moreover, specific U94 properties, such as the ability to modulate angiogenesis pathways, have been exploited to counteract cancer development. Here, we review the information available on this key HHV-6 gene, highlighting its potential uses.
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11
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Luchicchi A, Pattij T, Viaña JNM, de Kloet S, Marchant N. Tracing goes viral: Viruses that introduce expression of fluorescent proteins in chemically-specific neurons. J Neurosci Methods 2020; 348:109004. [PMID: 33242528 DOI: 10.1016/j.jneumeth.2020.109004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 11/12/2020] [Accepted: 11/16/2020] [Indexed: 12/26/2022]
Abstract
Over the last century, there has been great progress in understanding how the brain works. In particular, the last two decades have been crucial in gaining more awareness over the complex functioning of neurotransmitter systems. The use of viral vectors in neuroscience has been pivotal for such development. Exploiting the properties of viral particles, modifying them according to the research needs, and making them target chemically-specific neurons, techniques such as optogenetics and chemogenetics have been developed, which could lead to a giant step toward gene therapy for brain disorders. In this review, we aim to provide an overview of some of the most widely used viral techniques in neuroscience. We will discuss advantages and disadvantages of these methods. In particular, attention is dedicated to the pivotal role played by the introduction of adeno-associated virus and the retrograde tracer canine-associated-2 Cre virus in order to achieve optimal visualization, and interrogation, of chemically-specific neuronal populations and their projections.
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Affiliation(s)
- Antonio Luchicchi
- Department of Anatomy and Neurosciences, Amsterdam UMC, VU University Medical Center, de Boelelaan 1108, 1081HZ, Amsterdam, the Netherlands.
| | - Tommy Pattij
- Department of Anatomy and Neurosciences, Amsterdam UMC, VU University Medical Center, de Boelelaan 1108, 1081HZ, Amsterdam, the Netherlands
| | - John Noel M Viaña
- Center for Neurogenomics and Cognitive Research (CNCR), VU University Amsterdam, de Boelelaan 1085, 1081HZ, Amsterdam, the Netherlands; Australian National Centre for the Public Awareness of Science, ANU College of Science, The Australian National University, Linnaeus Way, Acton, ACT 2601, Australia
| | - Sybren de Kloet
- Center for Neurogenomics and Cognitive Research (CNCR), VU University Amsterdam, de Boelelaan 1085, 1081HZ, Amsterdam, the Netherlands
| | - Nathan Marchant
- Department of Anatomy and Neurosciences, Amsterdam UMC, VU University Medical Center, de Boelelaan 1108, 1081HZ, Amsterdam, the Netherlands
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12
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Maurer AC, Weitzman MD. Adeno-Associated Virus Genome Interactions Important for Vector Production and Transduction. Hum Gene Ther 2020; 31:499-511. [PMID: 32303138 PMCID: PMC7232694 DOI: 10.1089/hum.2020.069] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Accepted: 04/16/2020] [Indexed: 12/12/2022] Open
Abstract
Recombinant adeno-associated virus has emerged as one of the most promising gene therapy delivery vectors. Development of these vectors took advantage of key features of the wild-type adeno-associated virus (AAV), enabled by basic studies of the underlying biology and requirements for transcription, replication, and packaging of the viral genome. Each step in generating and utilizing viral vectors involves numerous molecular interactions that together determine the efficiency of vector production and gene delivery. Once delivered into the cell, interactions with host proteins will determine the fate of the viral genome, and these will impact the intended goal of gene delivery. Here, we provide an overview of known interactions of the AAV genome with viral and cellular proteins involved in its amplification, packaging, and expression. Further appreciation of how the AAV genome interacts with host factors will enhance how this simple virus can be harnessed for an array of vector purposes that benefit human health.
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Affiliation(s)
- Anna C. Maurer
- Department of Molecular and Cell Biology, University of California, Berkeley, California, USA
| | - Matthew D. Weitzman
- Division of Protective Immunity, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Division of Cancer Pathobiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
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13
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TALEN mediated gene editing in a mouse model of Fanconi anemia. Sci Rep 2020; 10:6997. [PMID: 32332829 PMCID: PMC7181878 DOI: 10.1038/s41598-020-63971-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 02/28/2020] [Indexed: 01/05/2023] Open
Abstract
The promising ability to genetically modify hematopoietic stem and progenitor cells by precise gene editing remains challenging due to their sensitivity to in vitro manipulations and poor efficiencies of homologous recombination. This study represents the first evidence of implementing a gene editing strategy in a murine safe harbor locus site that phenotypically corrects primary cells from a mouse model of Fanconi anemia A. By means of the co-delivery of transcription activator-like effector nucleases and a donor therapeutic FANCA template to the Mbs85 locus, we achieved efficient gene targeting (23%) in mFA-A fibroblasts. This resulted in the phenotypic correction of these cells, as revealed by the reduced sensitivity of these cells to mitomycin C. Moreover, robust evidence of targeted integration was observed in murine wild type and FA-A hematopoietic progenitor cells, reaching mean targeted integration values of 21% and 16% respectively, that were associated with the phenotypic correction of these cells. Overall, our results demonstrate the feasibility of implementing a therapeutic targeted integration strategy into the mMbs85 locus, ortholog to the well-validated hAAVS1, constituting the first study of gene editing in mHSC with TALEN, that sets the basis for the use of a new safe harbor locus in mice.
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14
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Abstract
Although the sequence of the AAV inverted terminal repeat has been known for 40 years, there are still unanswered questions about functions attributable to the terminal 125 nucleotides.
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Affiliation(s)
- Kenneth I Berns
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, USA
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15
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Current understanding of human herpesvirus 6 (HHV-6) chromosomal integration. Antiviral Res 2020; 176:104720. [PMID: 32044155 DOI: 10.1016/j.antiviral.2020.104720] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 01/21/2020] [Accepted: 01/23/2020] [Indexed: 12/12/2022]
Abstract
Human herpesvirus 6A (HHV-6A) and 6B (HHV-6B) are members of the genus Roseolovirus in the Betaherpesvirinae subfamily. HHV-6B infects humans in the first years of life, has a seroprevalence of more than 90% and causes Roseola Infantum, but less is known about HHV-6A. While most other herpesviruses maintain their latent genome as a circular episome, HHV-6A and HHV-6B (HHV-6A/B) have been shown to integrate their genome into the telomeres of infected cells. HHV-6A/B can also integrate into the chromosomes of germ cells, resulting in individuals carrying a copy of the virus genome in every nucleated cell of their bodies. This review highlights our current understanding of HHV-6A/B integration and reactivation as well as aspects that should be addressed in the future of this relatively young research area. It forms part of an online symposium on the prevention and therapy of DNA virus infections, dedicated to the memory of Mark Prichard.
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16
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Wang D, Tai PWL, Gao G. Adeno-associated virus vector as a platform for gene therapy delivery. Nat Rev Drug Discov 2019; 18:358-378. [PMID: 30710128 DOI: 10.1038/s41573-019-0012-9] [Citation(s) in RCA: 1172] [Impact Index Per Article: 234.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Adeno-associated virus (AAV) vectors are the leading platform for gene delivery for the treatment of a variety of human diseases. Recent advances in developing clinically desirable AAV capsids, optimizing genome designs and harnessing revolutionary biotechnologies have contributed substantially to the growth of the gene therapy field. Preclinical and clinical successes in AAV-mediated gene replacement, gene silencing and gene editing have helped AAV gain popularity as the ideal therapeutic vector, with two AAV-based therapeutics gaining regulatory approval in Europe or the United States. Continued study of AAV biology and increased understanding of the associated therapeutic challenges and limitations will build the foundation for future clinical success.
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Affiliation(s)
- Dan Wang
- Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester, MA, USA.,Li Weibo Institute for Rare Diseases Research, University of Massachusetts Medical School, Worcester, MA, USA.,Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, USA
| | - Phillip W L Tai
- Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester, MA, USA.,Li Weibo Institute for Rare Diseases Research, University of Massachusetts Medical School, Worcester, MA, USA.,Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, USA
| | - Guangping Gao
- Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester, MA, USA. .,Li Weibo Institute for Rare Diseases Research, University of Massachusetts Medical School, Worcester, MA, USA. .,Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, USA.
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17
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Li C, Mishra AS, Gil S, Wang M, Georgakopoulou A, Papayannopoulou T, Hawkins RD, Lieber A. Targeted Integration and High-Level Transgene Expression in AAVS1 Transgenic Mice after In Vivo HSC Transduction with HDAd5/35++ Vectors. Mol Ther 2019; 27:2195-2212. [PMID: 31494053 DOI: 10.1016/j.ymthe.2019.08.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 08/10/2019] [Accepted: 08/14/2019] [Indexed: 12/16/2022] Open
Abstract
Our goal is the development of in vivo hematopoietic stem cell (HSC) transduction technology with targeted integration. To achieve this, we modified helper-dependent HDAd5/35++ vectors to express a CRISPR/Cas9 specific to the "safe harbor" adeno-associated virus integration site 1 (AAVS1) locus and to provide a donor template for targeted integration through homology-dependent repair. We tested the HDAd-CRISPR + HDAd-donor vector system in AAVS1 transgenic mice using a standard ex vivo HSC gene therapy approach as well as a new in vivo HSC transduction approach that involves HSC mobilization and intravenous HDAd5/35++ injections. In both settings, the majority of treated mice had transgenes (GFP or human γ-globin) integrated into the AAVS1 locus. On average, >60% of peripheral blood cells expressed the transgene after in vivo selection with low-dose O6BG/bis-chloroethylnitrosourea (BCNU). Ex vivo and in vivo HSC transduction and selection studies with HDAd-CRISPR + HDAd-globin-donor resulted in stable γ-globin expression at levels that were significantly higher (>20% γ-globin of adult mouse globin) than those achieved in previous studies with a SB100x-transposase-based HDAd5/35++ system that mediates random integration. The ability to achieve therapeutically relevant transgene expression levels after in vivo HSC transduction and selection and targeted integration make our HDAd5/35++-based vector system a new tool in HSC gene therapy.
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Affiliation(s)
- Chang Li
- Division of Medical Genetics, Department of Medicine, University of Washington, Box 357720, Seattle, WA 98195, USA
| | - Arpit Suresh Mishra
- Division of Medical Genetics, Department of Medicine, University of Washington, Box 357720, Seattle, WA 98195, USA
| | - Sucheol Gil
- Division of Medical Genetics, Department of Medicine, University of Washington, Box 357720, Seattle, WA 98195, USA
| | - Meng Wang
- Division of Medical Genetics, Department of Medicine, University of Washington, Box 357720, Seattle, WA 98195, USA
| | - Aphrodite Georgakopoulou
- Division of Medical Genetics, Department of Medicine, University of Washington, Box 357720, Seattle, WA 98195, USA
| | | | - R David Hawkins
- Division of Medical Genetics, Department of Medicine, University of Washington, Box 357720, Seattle, WA 98195, USA
| | - André Lieber
- Division of Medical Genetics, Department of Medicine, University of Washington, Box 357720, Seattle, WA 98195, USA; Department of Pathology, University of Washington, Box 357720, Seattle, WA 98195, USA.
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18
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Mougari S, Sahmi-Bounsiar D, Levasseur A, Colson P, La Scola B. Virophages of Giant Viruses: An Update at Eleven. Viruses 2019; 11:v11080733. [PMID: 31398856 PMCID: PMC6723459 DOI: 10.3390/v11080733] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 07/31/2019] [Accepted: 08/02/2019] [Indexed: 12/19/2022] Open
Abstract
The last decade has been marked by two eminent discoveries that have changed our perception of the virology field: The discovery of giant viruses and a distinct new class of viral agents that parasitize their viral factories, the virophages. Coculture and metagenomics have actively contributed to the expansion of the virophage family by isolating dozens of new members. This increase in the body of data on virophage not only revealed the diversity of the virophage group, but also the relevant ecological impact of these small viruses and their potential role in the dynamics of the microbial network. In addition, the isolation of virophages has led us to discover previously unknown features displayed by their host viruses and cells. In this review, we present an update of all the knowledge on the isolation, biology, genomics, and morphological features of the virophages, a decade after the discovery of their first member, the Sputnik virophage. We discuss their parasitic lifestyle as bona fide viruses of the giant virus factories, genetic parasites of their genomes, and then their role as a key component or target for some host defense mechanisms during the tripartite virophage–giant virus–host cell interaction. We also present the latest advances regarding their origin, classification, and definition that have been widely discussed.
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Affiliation(s)
- Said Mougari
- Aix-Marseille Université, Institut de Recherche pour le Développement (IRD), Assistance Publique - Hôpitaux de Marseille (AP-HM), Microbes Evolution Phylogeny and Infections (MEPHI), 27 boulevard Jean Moulin, 13005 Marseille, France
- Institut Hospitalo-Universitaire (IHU) Méditerranée Infection, 19-21 boulevard Jean Moulin, 13005 Marseille, France
| | - Dehia Sahmi-Bounsiar
- Aix-Marseille Université, Institut de Recherche pour le Développement (IRD), Assistance Publique - Hôpitaux de Marseille (AP-HM), Microbes Evolution Phylogeny and Infections (MEPHI), 27 boulevard Jean Moulin, 13005 Marseille, France
- Institut Hospitalo-Universitaire (IHU) Méditerranée Infection, 19-21 boulevard Jean Moulin, 13005 Marseille, France
| | - Anthony Levasseur
- Aix-Marseille Université, Institut de Recherche pour le Développement (IRD), Assistance Publique - Hôpitaux de Marseille (AP-HM), Microbes Evolution Phylogeny and Infections (MEPHI), 27 boulevard Jean Moulin, 13005 Marseille, France
- Institut Hospitalo-Universitaire (IHU) Méditerranée Infection, 19-21 boulevard Jean Moulin, 13005 Marseille, France
| | - Philippe Colson
- Aix-Marseille Université, Institut de Recherche pour le Développement (IRD), Assistance Publique - Hôpitaux de Marseille (AP-HM), Microbes Evolution Phylogeny and Infections (MEPHI), 27 boulevard Jean Moulin, 13005 Marseille, France.
- Institut Hospitalo-Universitaire (IHU) Méditerranée Infection, 19-21 boulevard Jean Moulin, 13005 Marseille, France.
| | - Bernard La Scola
- Aix-Marseille Université, Institut de Recherche pour le Développement (IRD), Assistance Publique - Hôpitaux de Marseille (AP-HM), Microbes Evolution Phylogeny and Infections (MEPHI), 27 boulevard Jean Moulin, 13005 Marseille, France.
- Institut Hospitalo-Universitaire (IHU) Méditerranée Infection, 19-21 boulevard Jean Moulin, 13005 Marseille, France.
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19
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Li J, Dong Y, Sun Y, Lai Z, Zhao Y, Liu P, Gao Y, Chen X, Gu J. A Novel Densovirus Isolated From the Asian Tiger Mosquito Displays Varied Pathogenicity Depending on Its Host Species. Front Microbiol 2019; 10:1549. [PMID: 31333635 PMCID: PMC6624781 DOI: 10.3389/fmicb.2019.01549] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 06/20/2019] [Indexed: 11/18/2022] Open
Abstract
Mosquito-borne viral diseases (MBVDs) continue to pose a significant global public health burden. Mosquito control remains a core intervention strategy in integrated mosquito management (IMM) programs to reduce the transmission of MBVDs. Mosquito densoviruses (MDVs) are mosquito-specific entomopathogenic viruses, and their attractive biological and pathogenic characteristics make MDVs potential biological control agents as alternatives to traditional chemical pesticides. However, different viral strains vary greatly in their pathogenicity against different mosquito species, which poses an obstacle for the wide application of MDVs in vector control. In this study, a novel MDV, Aedes albopictus densovirus-7 (AalDV-7), was isolated from field-collected Aedes albopictus in the dengue-endemic area of Guangzhou, China. The complete 4,048 nt genome of AalDV-7 was cloned and sequenced, and the transcription and translation of three open reading frames (ORFs) were characterized. Phylogenetic analysis indicated that AalDV-7 clustered with MDVs mostly isolated from indigenous mosquitoes. The pathogenicity of AalDV-7 to A. albopictus, Aedes aegypti, and Culex quinquefasciatus larvae was completely different, and the median lethal dose (LD50) of AalDV-7 in A. albopictus which was 109.48 genome equivalents per ml (geq/ml) was 12 and 46 times lower than those in A. aegypti (1010.56 geq/ml) and C. quinquefasciatus (1011.15 geq/ml). Furthermore, the median lethal time (LT50) value in A. albopictus (7.72 days) was 25% and 26% shorter than those in A. aegypti (10.24 days) and C. quinquefasciatus (10.42 days) at a titer of 1011 geq/ml. Furthermore, the mortality of AalDV-7-infected mosquitoes increased in a dose-dependent manner, and the highest mortality was found in A. albopictus larvae exposed to 1011 geq/ml AalDV-7 (82.00%). Sublethal effects analysis also showed that AalDV-7 infection significantly decreased pupation and emergence rates. The 1st–2nd instar larvae of all three mosquito species showed a near 100% infection rate, and the highest relative vial titer (305.97 ± 67.57 geq/ng) was observed in the 1st–2nd instar larvae of C. quinquefasciatus. These pathogenic characteristics make AalDV-7 a potential MBVDs control agent in China, whereas its negligible pathogenicity and high infection rate and viral dose in vivo make it a good candidate for gene delivery vectors in C. quinquefasciatus gene function analysis. In conclusion, the continuous discovery and isolation of new MDVs enrich the pool of mosquito entomopathogenic viruses and provide a variety of choices for optimal MDVs or combinations of MDVs to target certain mosquitoes.
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Affiliation(s)
- Jing Li
- Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Pathogen Biology, School of Public Health, Southern Medical University, Guangzhou, China
| | - Yunqiao Dong
- Reproductive Medical Centre of Guangdong Women and Children's Hospital, Guangzhou, China
| | - Yan Sun
- Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Pathogen Biology, School of Public Health, Southern Medical University, Guangzhou, China
| | - Zetian Lai
- Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Pathogen Biology, School of Public Health, Southern Medical University, Guangzhou, China
| | - Yijie Zhao
- Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Pathogen Biology, School of Public Health, Southern Medical University, Guangzhou, China
| | - Peiwen Liu
- Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Pathogen Biology, School of Public Health, Southern Medical University, Guangzhou, China
| | - Yonghui Gao
- Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Pathogen Biology, School of Public Health, Southern Medical University, Guangzhou, China
| | - Xiaoguang Chen
- Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Pathogen Biology, School of Public Health, Southern Medical University, Guangzhou, China
| | - Jinbao Gu
- Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Pathogen Biology, School of Public Health, Southern Medical University, Guangzhou, China
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20
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Callaway HM, Subramanian S, Urbina CA, Barnard KN, Dick RA, Bator CM, Hafenstein SL, Gifford RJ, Parrish CR. Examination and Reconstruction of Three Ancient Endogenous Parvovirus Capsid Protein Gene Remnants Found in Rodent Genomes. J Virol 2019; 93:e01542-18. [PMID: 30626673 PMCID: PMC6401472 DOI: 10.1128/jvi.01542-18] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 12/24/2018] [Indexed: 11/20/2022] Open
Abstract
Parvovirus-derived endogenous viral elements (EVEs) have been found in the genomes of many different animal species, resulting from integration events that may have occurred from more than 50 million years ago to much more recently. Here, we further investigate the properties of autonomous parvovirus EVEs and describe their relationships to contemporary viruses. While we did not find any intact capsid protein open reading frames in the integrated viral sequences, we examined three EVEs that were repaired to form full-length sequences with relatively few changes. These sequences were found in the genomes of Rattus norvegicus (brown rat), Mus spretus (Algerian mouse), and Apodemus sylvaticus (wood mouse). The R. norvegicus sequence was not present in the genomes of the closely related species R. rattus, R. tanezumi, R. exulans, and R. everetti, indicating that it was less than 2 million years old, and the M. spretus and A. sylvaticus sequences were not found in the published genomes of other mouse species, also indicating relatively recent insertions. The M. spretus VP2 sequence assembled into capsids, which had high thermal stability, bound the sialic acid N-acetylneuraminic acid, and entered murine L cells. The 3.89-Å structure of the M. spretus virus-like particles (VLPs), determined using cryo-electron microscopy, showed similarities to rodent and porcine parvovirus capsids. The repaired VP2 sequences from R. norvegicus and A. sylvaticus did not assemble as first prepared, but chimeras combining capsid surface loops from R. norvegicus with canine parvovirus assembled, allowing some of that capsid's structures and functions to be examined.IMPORTANCE Parvovirus endogenous viral elements (EVEs) that have been incorporated into the genomes of different animals represent remnants of the DNA sequences of ancient viruses that infected the ancestors of those animals millions of years ago, but we know little about their properties or how they differ from currently circulating parvoviruses. By expressing the capsid proteins of different parvovirus EVEs that were found integrated into the genomes of three different rodents, we can examine their structures and functions. A VP2 (major capsid protein) EVE sequence from a mouse genome assembled into capsids that had a similar structure and biophysical properties to extant parvoviruses and also bound sialic acids and entered rodent cells. Chimeras formed from combinations of canine parvovirus and portions of the parvovirus sequences from the brown rat genome allowed us to examine the structures and functions of the surface loops of that EVE capsid.
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Affiliation(s)
- Heather M Callaway
- Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Suriyasri Subramanian
- Department of Medicine, Penn State University College of Medicine, Hershey, Pennsylvania, USA
- Department of Biochemistry and Molecular Biology, Penn State University, University Park, Pennsylvania, USA
| | - Christian A Urbina
- Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Karen N Barnard
- Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Robert A Dick
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, USA
| | - Carol M Bator
- Department of Medicine, Penn State University College of Medicine, Hershey, Pennsylvania, USA
- Department of Biochemistry and Molecular Biology, Penn State University, University Park, Pennsylvania, USA
| | - Susan L Hafenstein
- Department of Medicine, Penn State University College of Medicine, Hershey, Pennsylvania, USA
- Department of Biochemistry and Molecular Biology, Penn State University, University Park, Pennsylvania, USA
| | - Robert J Gifford
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Colin R Parrish
- Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
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21
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Li P, Marino MP, Zou J, Argaw T, Morreale MT, Iaffaldano BJ, Reiser J. Efficiency and Specificity of Targeted Integration Mediated by the Adeno-Associated Virus Serotype 2 Rep 78 Protein. Hum Gene Ther Methods 2019; 29:135-145. [PMID: 29860898 DOI: 10.1089/hgtb.2018.052] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The adeno-associated virus serotype 2 (AAV2) Rep 78 protein, a strand-specific endonuclease (nickase) promotes site-specific integration of transgene sequences bearing homology arms corresponding to the AAVS1 safe harbor locus. To investigate the efficiency and specificity of this approach, plasmid-based donor vectors were tested in concert with nuclease encoding vectors, including an engineered version of the AAV2 Rep 78 protein, an AAVS1-specific zinc finger nuclease (ZFN), and the CRISPR-Cas9 components in HEK 293 cells. The Rep 78 and ZFN-based approaches were also compared in HEK 293 cells and in human induced pluripotent stem cells using integrase deficient lentiviral vectors. The targeting efficiencies involving the Rep 78 protein were similar to those involving the AAVS1-specific ZFN, while the targeting specificity for the Rep 78 protein was lower compared to that of the ZFN. It is anticipated that the Rep 78 nickase-based targeting approach may ultimately contribute to the reduction of risks associated with other genome editing approaches involving DNA double-strand breaks.
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Affiliation(s)
- Pingjuan Li
- 1 Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research , Food and Drug Administration, Silver Spring, Maryland.,2 Gemini Therapeutics, Inc. , Cambridge, Massachusetts
| | - Michael P Marino
- 1 Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research , Food and Drug Administration, Silver Spring, Maryland
| | - Jizhong Zou
- 3 National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda, Maryland
| | - Takele Argaw
- 1 Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research , Food and Drug Administration, Silver Spring, Maryland
| | - Michael T Morreale
- 1 Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research , Food and Drug Administration, Silver Spring, Maryland
| | - Brian J Iaffaldano
- 1 Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research , Food and Drug Administration, Silver Spring, Maryland
| | - Jakob Reiser
- 1 Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research , Food and Drug Administration, Silver Spring, Maryland
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22
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Methylation Status of the Adeno-Associated Virus Type 2 (AAV2). Viruses 2019; 11:v11010038. [PMID: 30634383 PMCID: PMC6356613 DOI: 10.3390/v11010038] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 01/04/2019] [Accepted: 01/04/2019] [Indexed: 11/16/2022] Open
Abstract
To analyze the methylation status of wild-type adeno-associated virus type 2 (AAV2), bisulfite PCR sequencing (BPS) of the packaged viral genome and its integrated form was performed and 262 of the total 266 CG dinucleotides (CpG) were mapped. In virion-packaged DNA, the ratio of the methylated cytosines ranged between 0⁻1.7%. In contrast, the chromosomally integrated AAV2 genome was hypermethylated with an average of 76% methylation per CpG site. The methylation level showed local minimums around the four known AAV2 promoters. To study the effect of methylation on viral rescue and replication, the replication initiation capability of CpG methylated and non-CpG methylated AAV DNA was compared. The in vitro hypermethylation of the viral genome does not inhibit its rescue and replication from a plasmid transfected into cells. This insensitivity of the viral replicative machinery to methylation may permit the rescue of the integrated heavily methylated AAV genome from the host's chromosomes.
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23
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Viral Delivery Systems for CRISPR. Viruses 2019; 11:v11010028. [PMID: 30621179 PMCID: PMC6356701 DOI: 10.3390/v11010028] [Citation(s) in RCA: 135] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 12/31/2018] [Accepted: 01/01/2019] [Indexed: 12/16/2022] Open
Abstract
The frontiers of precision medicine have been revolutionized by the development of Clustered Regularly-Interspaced Short Palindromic Repeats (CRISPR)/Cas9 as an editing tool. CRISPR/Cas9 has been used to develop animal models, understand disease mechanisms, and validate treatment targets. In addition, it is regarded as an effective tool for genome surgery when combined with viral delivery vectors. In this article, we will explore the various viral mechanisms for delivering CRISPR/Cas9 into tissues and cells, as well as the benefits and drawbacks of each method. We will also review the history and recent development of CRISPR and viral vectors and discuss their applications as a powerful tool in furthering our exploration of disease mechanisms and therapies.
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24
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Agúndez L, Zárate-Pérez F, Meier AF, Bardelli M, Llosa M, Escalante CR, Linden RM, Henckaerts E. Exchange of functional domains between a bacterial conjugative relaxase and the integrase of the human adeno-associated virus. PLoS One 2018; 13:e0200841. [PMID: 30016371 PMCID: PMC6049929 DOI: 10.1371/journal.pone.0200841] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 07/02/2018] [Indexed: 12/21/2022] Open
Abstract
Endonucleases of the HUH family are specialized in processing single-stranded DNA in a variety of evolutionarily highly conserved biological processes related to mobile genetic elements. They share a structurally defined catalytic domain for site-specific nicking and strand-transfer reactions, which is often linked to the activities of additional functional domains, contributing to their overall versatility. To assess if these HUH domains could be interchanged, we created a chimeric protein from two distantly related HUH endonucleases, containing the N-terminal HUH domain of the bacterial conjugative relaxase TrwC and the C-terminal DNA helicase domain of the human adeno-associated virus (AAV) replicase and site-specific integrase. The purified chimeric protein retained oligomerization properties and DNA helicase activities similar to Rep68, while its DNA binding specificity and cleaving-joining activity at oriT was similar to TrwC. Interestingly, the chimeric protein could catalyse site-specific integration in bacteria with an efficiency comparable to that of TrwC, while the HUH domain of TrwC alone was unable to catalyze this reaction, implying that the Rep68 C-terminal helicase domain is complementing the TrwC HUH domain to achieve site-specific integration into TrwC targets in bacteria. Our results illustrate how HUH domains could have acquired through evolution other domains in order to attain new roles, contributing to the functional flexibility observed in this protein superfamily.
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Affiliation(s)
- Leticia Agúndez
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, United Kingdom
| | - Francisco Zárate-Pérez
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, Virginia, United States of America
| | - Anita F. Meier
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, United Kingdom
| | - Martino Bardelli
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, United Kingdom
| | - Matxalen Llosa
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC-SODERCAN, Santander, Spain
- * E-mail: (EH); (ML)
| | - Carlos R. Escalante
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, Virginia, United States of America
| | - R. Michael Linden
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, United Kingdom
| | - Els Henckaerts
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, United Kingdom
- * E-mail: (EH); (ML)
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Human Neural Stem Cells with GDNF Site-Specific Integration at AAVS1 by Using AAV Vectors Retained Their Stemness. Neurochem Res 2018; 43:930-937. [PMID: 29435804 DOI: 10.1007/s11064-018-2498-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 01/05/2018] [Accepted: 02/07/2018] [Indexed: 01/30/2023]
Abstract
The neural stem cells (NSCs) have the ability to self-renew, and to migrate to pathologically altered regions of the central nervous system. Glial cell derived neurotrophic factor (GDNF) could protect dopamine neurons and rescue motor neurons in vivo, which has been proposed as a promising candidate for the treatments of degenerative neurological diseases. In order to combine the advantages of neurotrophic factors and stem cells in clinical therapy, we established the modified hNSCs that has site-specific integration of GDNF gene by using recombinant adeno-associated virus (rAAV) vectors. The hNSCs were co-infected by rAAV2-EGFP-GDNF and rAAV2-SVAV2 which provide integrase to specifically integrate GDNF gene into AAVS1 site. The GDNF-hNSCs maintained their original stem cell characteristics and the ability to differentiate into neurons in vitro. In the animal model, the GDNF-hNSCs were specifically transplanted into CA1 area of hippocampi and could migrate to the dentate gyrus region and differentiate into neuronal cells while maintaining GDNF expression. hNSCs with GDNF gene site-specific integration at AAVS1 by using AAV vectors retained their stemness and effectively expressed GDNF, which indicates the potential of employing transplanted hNPCs for treatment of brain injuries and degenerative neurological diseases.
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Cell Cycle-Dependent Expression of Adeno-Associated Virus 2 (AAV2) Rep in Coinfections with Herpes Simplex Virus 1 (HSV-1) Gives Rise to a Mosaic of Cells Replicating either AAV2 or HSV-1. J Virol 2017; 91:JVI.00357-17. [PMID: 28515305 DOI: 10.1128/jvi.00357-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 05/05/2017] [Indexed: 12/19/2022] Open
Abstract
Adeno-associated virus 2 (AAV2) depends on the simultaneous presence of a helper virus such as herpes simplex virus 1 (HSV-1) for productive replication. At the same time, AAV2 efficiently blocks the replication of HSV-1, which would eventually limit its own replication by diminishing the helper virus reservoir. This discrepancy begs the question of how AAV2 and HSV-1 can coexist in a cell population. Here we show that in coinfected cultures, AAV2 DNA replication takes place almost exclusively in S/G2-phase cells, while HSV-1 DNA replication is restricted to G1 phase. Live microscopy revealed that not only wild-type AAV2 (wtAAV2) replication but also reporter gene expression from both single-stranded and double-stranded (self-complementary) recombinant AAV2 vectors preferentially occurs in S/G2-phase cells, suggesting that the preference for S/G2 phase is independent of the nature of the viral genome. Interestingly, however, a substantial proportion of S/G2-phase cells transduced by the double-stranded but not the single-stranded recombinant AAV2 vectors progressed through mitosis in the absence of the helper virus. We conclude that cell cycle-dependent AAV2 rep expression facilitates cell cycle-dependent AAV2 DNA replication and inhibits HSV-1 DNA replication. This may limit competition for cellular and viral helper factors and, hence, creates a biological niche for either virus to replicate.IMPORTANCE Adeno-associated virus 2 (AAV2) differs from most other viruses, as it requires not only a host cell for replication but also a helper virus such as an adenovirus or a herpesvirus. This situation inevitably leads to competition for cellular resources. AAV2 has been shown to efficiently inhibit the replication of helper viruses. Here we present a new facet of the interaction between AAV2 and one of its helper viruses, herpes simplex virus 1 (HSV-1). We observed that AAV2 rep gene expression is cell cycle dependent and gives rise to distinct time-controlled windows for HSV-1 replication. High Rep protein levels in S/G2 phase support AAV2 replication and inhibit HSV-1 replication. Conversely, low Rep protein levels in G1 phase permit HSV-1 replication but are insufficient for AAV2 replication. This allows both viruses to productively replicate in distinct sets of dividing cells.
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Hagedorn C, Schnödt-Fuchs M, Boehme P, Abdelrazik H, Lipps HJ, Büning H. S/MAR Element Facilitates Episomal Long-Term Persistence of Adeno-Associated Virus Vector Genomes in Proliferating Cells. Hum Gene Ther 2017; 28:1169-1179. [PMID: 28665147 DOI: 10.1089/hum.2017.025] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Adeno-associated virus (AAV) vectors are one of the most frequently applied gene transfer systems in research and human clinical trials. Since AAV vectors do not possess an integrase activity, application is restricted to terminally differentiated tissues if transgene expression is required long term. To overcome this limitation and to generate AAV vectors that persist episomally in dividing cells, AAV vector genomes were equipped with a scaffold/matrix attachment region (S/MAR). After a mild antibiotic selection, cells transduced with AAV-S/MAR established colonies that maintained long-term transgene expression (>50 population doublings) from replicating AAV vector episomes in the absence of further selection. Unexpectedly, with a lesser but still significant efficiency, the control vector (AAV-ΔS/MAR), a standard single-stranded AAV vector, also established stable transgene-expressing colonies, most of which were maintained as replicating episomes rather than integrated vector genomes. Thus, based on the result in HeLa cells, it is concluded that AAV vector genomes per se possess the ability to establish episomal maintenance in proliferating cells, a feature that can be enhanced by incorporation of a foreign genomic element such as an S/MAR element.
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Affiliation(s)
- Claudia Hagedorn
- 1 Institute of Cell Biology, ZBAF, University of Witten/Herdecke , Witten, Germany
| | - Maria Schnödt-Fuchs
- 2 Laboratory for AAV Vector Development, Center for Molecular Medicine Cologne (CMMC), University of Cologne , Cologne, Germany .,3 Department I of Internal Medicine, University Hospital Cologne , Cologne, Germany .,4 German Center for Infection Research (DZIF) , partner sites Bonn-Cologne and Hannover-Braunschweig
| | - Philip Boehme
- 1 Institute of Cell Biology, ZBAF, University of Witten/Herdecke , Witten, Germany .,5 Institute of Virology and Microbiology, ZBAF, University of Witten/Herdecke , Witten, Germany
| | - Heba Abdelrazik
- 2 Laboratory for AAV Vector Development, Center for Molecular Medicine Cologne (CMMC), University of Cologne , Cologne, Germany .,6 Clinical Pathology Department, Faculty of Medicine, Cairo University , Cairo, Egypt
| | - Hans J Lipps
- 1 Institute of Cell Biology, ZBAF, University of Witten/Herdecke , Witten, Germany
| | - Hildegard Büning
- 2 Laboratory for AAV Vector Development, Center for Molecular Medicine Cologne (CMMC), University of Cologne , Cologne, Germany .,3 Department I of Internal Medicine, University Hospital Cologne , Cologne, Germany .,4 German Center for Infection Research (DZIF) , partner sites Bonn-Cologne and Hannover-Braunschweig.,7 Laboratory for Infection Biology and Gene Transfer, Institute of Experimental Hematology, Hannover Medical School , Hannover, Germany
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28
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Luo Y, Frederick A, Martin JM, Scaria A, Cheng SH, Armentano D, Wadsworth SC, Vincent KA. AAVS1-Targeted Plasmid Integration in AAV Producer Cell Lines. Hum Gene Ther Methods 2017; 28:124-138. [PMID: 28504553 DOI: 10.1089/hgtb.2016.158] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Adeno-associated virus (AAV) producer cell lines are created via transfection of HeLaS3 cells with a single plasmid containing three components (the vector sequence, the AAV rep and cap genes, and a selectable marker gene). As this plasmid contains both the cis (Rep binding sites) and trans (Rep protein encoded by the rep gene) elements required for site-specific integration, it was predicted that plasmid integration might occur within the AAVS1 locus on human chromosome 19 (chr19). The objective of this study was to investigate whether integration in AAVS1 might be correlated with vector yield. Plasmid integration sites within several independent cell lines were assessed via Southern, fluorescence in situ hybridization (FISH) and PCR analyses. In the Southern analyses, the presence of fragments detected by both rep- and AAVS1-specific probes suggested that for several mid- and high-producing lines, plasmid DNA had integrated into the AAVS1 locus. Analysis with puroR and AAVS1-specific probes suggested that integration in AAVS1 was a more widespread phenomenon. High-producing AAV2-secreted alkaline phosphatase (SEAP) lines (masterwell 82 [MW82] and MW278) were evaluated via FISH using probes specific for the plasmid, AAVS1, and a chr19 marker. FISH analysis detected two plasmid integration sites in MW278 (neither in AAVS1), while a total of three sites were identified in MW82 (two in AAVS1). An inverse PCR assay confirmed integration within AAVS1 for several mid- and high-producing lines. In summary, the FISH, Southern, and PCR data provide evidence of site-specific integration of the plasmid within AAVS1 in several AAV producer cell lines. The data also suggest that integration in AAVS1 is a general phenomenon that is not necessarily restricted to high producers. The results also suggest that plasmid integration within the AAVS1 locus is not an absolute requirement for a high vector yield.
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Affiliation(s)
- Yuxia Luo
- 1 Sanofi Genzyme , Framingham, Massachusetts
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29
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Identification of a Functionally Relevant Adeno-Associated Virus Rep68 Oligomeric Interface. J Virol 2016; 90:6612-6624. [PMID: 27170758 PMCID: PMC4944284 DOI: 10.1128/jvi.00356-16] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 05/01/2016] [Indexed: 12/11/2022] Open
Abstract
The life cycle of the human parvovirus adeno-associated virus (AAV) is orchestrated by four Rep proteins. The large Rep proteins, Rep78 and Rep68, are remarkably multifunctional and display a range of biochemical activities, including DNA binding, nicking, and unwinding. Functionally, Rep78 and Rep68 are involved in transcriptional regulation, DNA replication, and genomic integration. Structurally, the Rep proteins share an AAA+ domain characteristic of superfamily 3 helicases, with the large Rep proteins additionally containing an N-terminal origin-binding domain (OBD) that specifically binds and nicks DNA. The combination of these domains, coupled with dynamic oligomerization properties, is the basis for the remarkable multifunctionality displayed by Rep68 and Rep78 during the AAV life cycle. In this report, we describe an oligomeric interface formed by Rep68 and demonstrate how disruption of this interface has drastic effects on both the oligomerization and functionality of the Rep proteins. Our results support a role for the four-helix bundle in the helicase domain of Rep68 as a bona fide oligomerization domain (OD). We have identified key residues in the OD that are critical for the stabilization of the Rep68-Rep68 interface; mutation of these key residues disrupts the enzymatic activities of Rep68, including DNA binding and nicking, and compromises viral DNA replication and transcriptional regulation of the viral promoters. Taken together, our data contribute to our understanding of the dynamic and substrate-responsive Rep78/68 oligomerization that is instrumental in the regulation of the DNA transitions that take place during the AAV life cycle.
IMPORTANCE The limited genome size of small viruses has driven the evolution of highly multifunctional proteins that integrate different domains and enzymatic activities within a single polypeptide. The Rep68 protein from adeno-associated virus (AAV) combines a DNA binding and endonuclease domain with a helicase-ATPase domain, which together support DNA replication, transcriptional regulation, and site-specific integration. The coordination of the enzymatic activities of Rep68 remains poorly understood; however, Rep68 oligomerization and Rep68-DNA interactions have been suggested to play a crucial role. We investigated the determinants of Rep68 oligomerization and identified a hydrophobic interface necessary for Rep68 activity during the AAV life cycle. Our results provide new insights into the molecular mechanisms underlying the regulation of the versatile Rep proteins. Efficient production of AAV-based gene therapy vectors requires optimal Rep expression levels, and studies such as the one presented here could contribute to further optimization of AAV production schemes.
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Musayev FN, Zarate-Perez F, Bishop C, Burgner JW, Escalante CR. Structural Insights into the Assembly of the Adeno-associated Virus Type 2 Rep68 Protein on the Integration Site AAVS1. J Biol Chem 2015; 290:27487-99. [PMID: 26370092 DOI: 10.1074/jbc.m115.669960] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Indexed: 11/06/2022] Open
Abstract
Adeno-associated virus (AAV) is the only eukaryotic virus with the property of establishing latency by integrating site-specifically into the human genome. The integration site known as AAVS1 is located in chromosome 19 and contains multiple GCTC repeats that are recognized by the AAV non-structural Rep proteins. These proteins are multifunctional, with an N-terminal origin-binding domain (OBD) and a helicase domain joined together by a short linker. As a first step to understand the process of site-specific integration, we proceeded to characterize the recognition and assembly of Rep68 onto the AAVS1 site. We first determined the x-ray structure of AAV-2 Rep68 OBD in complex with the AAVS1 DNA site. Specificity is achieved through the interaction of a glycine-rich loop that binds the major groove and an α-helix that interacts with a downstream minor groove on the same face of the DNA. Although the structure shows a complex with three OBD molecules bound to the AAVS1 site, we show by using analytical centrifugation and electron microscopy that the full-length Rep68 forms a heptameric complex. Moreover, we determined that a minimum of two direct repeats is required to form a stable complex and to melt DNA. Finally, we show that although the individual domains bind DNA poorly, complex assembly requires oligomerization and cooperation between its OBD, helicase, and the linker domains.
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Affiliation(s)
- Faik N Musayev
- From the Department of Medicinal Chemistry, School of Pharmacy, and
| | - Francisco Zarate-Perez
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, Virginia 23298
| | - Clayton Bishop
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, Virginia 23298
| | - John W Burgner
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, Virginia 23298
| | - Carlos R Escalante
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, Virginia 23298
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Ling C, Wang Y, Lu Y, Wang L, Jayandharan GR, Aslanidi GV, Li B, Cheng B, Ma W, Lentz T, Ling C, Xiao X, Samulski RJ, Muzyczka N, Srivastava A. The Adeno-Associated Virus Genome Packaging Puzzle. J Mol Genet Med 2015; 9. [PMID: 26949410 DOI: 10.4172/1747-0862.1000175] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Affiliation(s)
- Chen Ling
- Division of Cellular and Molecular Therapy, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA; Powell Gene Therapy Center, University of Florida College of Medicine, Gainesville, FL, USA
| | - Yuan Wang
- Division of Cellular and Molecular Therapy, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA; Powell Gene Therapy Center, University of Florida College of Medicine, Gainesville, FL, USA; Department of Traditional Chinese Medicine, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Yuan Lu
- Department of Orthopedics & Rehabilitative Medicine, University of Florida College of Medicine, Gainesville, FL, USA
| | - Lina Wang
- Division of Cellular and Molecular Therapy, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA; Powell Gene Therapy Center, University of Florida College of Medicine, Gainesville, FL, USA; Department of Traditional Chinese Medicine, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Giridhara R Jayandharan
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, India
| | - George V Aslanidi
- Division of Cellular and Molecular Therapy, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA; Powell Gene Therapy Center, University of Florida College of Medicine, Gainesville, FL, USA
| | - Baozheng Li
- Division of Cellular and Molecular Therapy, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA; Powell Gene Therapy Center, University of Florida College of Medicine, Gainesville, FL, USA
| | - Binbin Cheng
- Division of Cellular and Molecular Therapy, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA; Department of Traditional Chinese Medicine, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Wenqin Ma
- Division of Cellular and Molecular Therapy, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA; Powell Gene Therapy Center, University of Florida College of Medicine, Gainesville, FL, USA
| | - Thomas Lentz
- Gene Therapy Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Changquan Ling
- Department of Traditional Chinese Medicine, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Xiao Xiao
- Gene Therapy Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Division of Molecular Pharmaceutics, University of North Carolina School of Pharmacy, Chapel Hill, NC, USA
| | - R Jude Samulski
- Gene Therapy Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Nicholas Muzyczka
- Powell Gene Therapy Center, University of Florida College of Medicine, Gainesville, FL, USA; Department of Molecular Genetics & Microbiology, University of Florida College of Medicine, Gainesville, FL, USA; Genetics Institute, University of Florida College of Medicine, Gainesville, FL, USA
| | - Arun Srivastava
- Division of Cellular and Molecular Therapy, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA; Powell Gene Therapy Center, University of Florida College of Medicine, Gainesville, FL, USA; Department of Molecular Genetics & Microbiology, University of Florida College of Medicine, Gainesville, FL, USA; Genetics Institute, University of Florida College of Medicine, Gainesville, FL, USA; Shands Cancer Center, University of Florida College of Medicine, Gainesville, FL, USA
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32
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Millet R, Jolinon N, Nguyen XN, Berger G, Cimarelli A, Greco A, Bertrand P, Odenthal M, Büning H, Salvetti A. Impact of the MRN Complex on Adeno-Associated Virus Integration and Replication during Coinfection with Herpes Simplex Virus 1. J Virol 2015; 89:6824-34. [PMID: 25903339 PMCID: PMC4468484 DOI: 10.1128/jvi.00171-15] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 04/13/2015] [Indexed: 12/11/2022] Open
Abstract
UNLABELLED Adeno-associated virus (AAV) is a helper-dependent parvovirus that requires coinfection with adenovirus (AdV) or herpes simplex virus 1 (HSV-1) to replicate. In the absence of the helper virus, AAV can persist in an episomal or integrated form. Previous studies have analyzed the DNA damage response (DDR) induced upon AAV replication to understand how it controls AAV replication. In particular, it was shown that the Mre11-Rad50-Nbs1 (MRN) complex, a major player of the DDR induced by double-stranded DNA breaks and stalled replication forks, could negatively regulate AdV and AAV replication during coinfection. In contrast, MRN favors HSV-1 replication and is recruited to AAV replication compartments that are induced in the presence of HSV-1. In this study, we examined the role of MRN during AAV replication induced by HSV-1. Our results indicated that knockdown of MRN significantly reduced AAV DNA replication after coinfection with wild-type (wt) HSV-1 or HSV-1 with the polymerase deleted. This effect was specific to wt AAV, since it did not occur with recombinant AAV vectors. Positive regulation of AAV replication by MRN was dependent on its DNA tethering activity but did not require its nuclease activities. Importantly, knockdown of MRN also negatively regulated AAV integration within the human AAVS1 site, both in the presence and in the absence of HSV-1. Altogether, this work identifies a new function of MRN during integration of the AAV genome and demonstrates that this DNA repair complex positively regulates AAV replication in the presence of HSV-1. IMPORTANCE Viral DNA genomes trigger a DNA damage response (DDR), which can be either detrimental or beneficial for virus replication. Adeno-associated virus (AAV) is a defective parvovirus that requires the help of an unrelated virus such as adenovirus (AdV) or herpes simplex virus 1 (HSV-1) for productive replication. Previous studies have demonstrated that the cellular Mre11-Rad50-Nbs1 (MRN) complex, a sensor and regulator of the DDR, negatively regulates AAV replication during coinfection with AdV, which counteracts this effect by inactivating the complex. Here, we demonstrate that MRN positively regulates AAV replication during coinfection with HSV-1. Importantly, our study also indicates that MRN also favors integration of AAV genomes within the human AAVS1 site. Altogether, this work indicates that MRN differentially regulates AAV replication depending on the helper virus which is present and identifies a new function of this DNA repair complex during AAV integration.
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Affiliation(s)
- Rachel Millet
- International Center for Research in Infectiology, INSERM U1111, CNRS UMR5308, Lyon, France Ecole Normale Supérieure de Lyon, Lyon, France Université de Lyon, UCB-Lyon 1, Lyon, France LabEx Ecofect, Université de Lyon, Lyon, France
| | - Nelly Jolinon
- International Center for Research in Infectiology, INSERM U1111, CNRS UMR5308, Lyon, France Ecole Normale Supérieure de Lyon, Lyon, France Université de Lyon, UCB-Lyon 1, Lyon, France
| | - Xuan-Nhi Nguyen
- International Center for Research in Infectiology, INSERM U1111, CNRS UMR5308, Lyon, France Ecole Normale Supérieure de Lyon, Lyon, France Université de Lyon, UCB-Lyon 1, Lyon, France LabEx Ecofect, Université de Lyon, Lyon, France
| | - Gregory Berger
- International Center for Research in Infectiology, INSERM U1111, CNRS UMR5308, Lyon, France Ecole Normale Supérieure de Lyon, Lyon, France Université de Lyon, UCB-Lyon 1, Lyon, France
| | - Andrea Cimarelli
- International Center for Research in Infectiology, INSERM U1111, CNRS UMR5308, Lyon, France Ecole Normale Supérieure de Lyon, Lyon, France Université de Lyon, UCB-Lyon 1, Lyon, France LabEx Ecofect, Université de Lyon, Lyon, France
| | - Anna Greco
- International Center for Research in Infectiology, INSERM U1111, CNRS UMR5308, Lyon, France Ecole Normale Supérieure de Lyon, Lyon, France Université de Lyon, UCB-Lyon 1, Lyon, France LabEx Ecofect, Université de Lyon, Lyon, France
| | - Pascale Bertrand
- INSERM U967, CEA, Université Paris Diderot, Université Paris Sud, CEA DSV, Institut de Radiobiologie Moléculaire et Cellulaire, Fontenay-aux-Roses, France
| | - Margarete Odenthal
- Institute for Pathology, University Hospital of Cologne, Cologne, Germany Center for Molecular Medicine of Cologne, University of Cologne, Cologne, Germany
| | - Hildegard Büning
- Center for Molecular Medicine of Cologne, University of Cologne, Cologne, Germany Institute of Experimental Hematology, Hannover Medical School, Hannover, Germany German Center for Infection Research, Bonn-Cologne Partner Site, Bonn-Cologne, Germany
| | - Anna Salvetti
- International Center for Research in Infectiology, INSERM U1111, CNRS UMR5308, Lyon, France Ecole Normale Supérieure de Lyon, Lyon, France Université de Lyon, UCB-Lyon 1, Lyon, France LabEx Ecofect, Université de Lyon, Lyon, France
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Trempe F, Gravel A, Dubuc I, Wallaschek N, Collin V, Gilbert-Girard S, Morissette G, Kaufer BB, Flamand L. Characterization of human herpesvirus 6A/B U94 as ATPase, helicase, exonuclease and DNA-binding proteins. Nucleic Acids Res 2015; 43:6084-98. [PMID: 25999342 PMCID: PMC4499131 DOI: 10.1093/nar/gkv503] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 05/04/2015] [Indexed: 02/02/2023] Open
Abstract
Human herpesvirus-6A (HHV-6A) and HHV-6B integrate their genomes into the telomeres of human chromosomes, however, the mechanisms leading to integration remain unknown. HHV-6A/B encode a protein that has been proposed to be involved in integration termed U94, an ortholog of adeno-associated virus type 2 (AAV-2) Rep68 integrase. In this report, we addressed whether purified recombinant maltose-binding protein (MBP)-U94 fusion proteins of HHV-6A/B possess biological functions compatible with viral integration. We could demonstrate that MBP-U94 efficiently binds both dsDNA and ssDNA containing telomeric repeats using gel shift assay and surface plasmon resonance. MBP-U94 is also able to hydrolyze adenosine triphosphate (ATP) to ADP, providing the energy for further catalytic activities. In addition, U94 displays a 3′ to 5′ exonuclease activity on dsDNA with a preference for 3′-recessed ends. Once the DNA strand reaches 8–10 nt in length, the enzyme dissociates it from the complementary strand. Lastly, MBP-U94 compromises the integrity of a synthetic telomeric D-loop through exonuclease attack at the 3′ end of the invading strand. The preferential DNA binding of MBP-U94 to telomeric sequences, its ability to hydrolyze ATP and its exonuclease/helicase activities suggest that U94 possesses all functions required for HHV-6A/B chromosomal integration.
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Affiliation(s)
- Frédéric Trempe
- Division of Infectious Disease and Immunity, CHU de Québec Research Center, Quebec city, Quebec G1V 4G2, Canada
| | - Annie Gravel
- Division of Infectious Disease and Immunity, CHU de Québec Research Center, Quebec city, Quebec G1V 4G2, Canada
| | - Isabelle Dubuc
- Division of Infectious Disease and Immunity, CHU de Québec Research Center, Quebec city, Quebec G1V 4G2, Canada
| | - Nina Wallaschek
- Institut für Virologie, Freie Universität Berlin, Berlin 14163, Germany
| | - Vanessa Collin
- Division of Infectious Disease and Immunity, CHU de Québec Research Center, Quebec city, Quebec G1V 4G2, Canada
| | - Shella Gilbert-Girard
- Division of Infectious Disease and Immunity, CHU de Québec Research Center, Quebec city, Quebec G1V 4G2, Canada
| | - Guillaume Morissette
- Division of Infectious Disease and Immunity, CHU de Québec Research Center, Quebec city, Quebec G1V 4G2, Canada
| | - Benedikt B Kaufer
- Institut für Virologie, Freie Universität Berlin, Berlin 14163, Germany
| | - Louis Flamand
- Division of Infectious Disease and Immunity, CHU de Québec Research Center, Quebec city, Quebec G1V 4G2, Canada Department of microbiology, infectious disease and immunology, Faculty of Medicine, Université Laval, Quebec city, Québec,G1V 0A6 Canada
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Presence of a trs-Like Motif Promotes Rep-Mediated Wild-Type Adeno-Associated Virus Type 2 Integration. J Virol 2015; 89:7428-32. [PMID: 25972561 DOI: 10.1128/jvi.00426-15] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Accepted: 05/04/2015] [Indexed: 11/20/2022] Open
Abstract
High-throughput integration site (IS) analysis of wild-type adeno-associated virus type 2 (wtAAV2) in human dermal fibroblasts (HDFs) and HeLa cells revealed that juxtaposition of a Rep binding site (RBS) and terminal resolution site (trs)-like motif leads to a 4-fold-increased probability of wtAAV integration. Electrophoretic mobility shift assays (EMSAs) confirmed binding of Rep to off-target RBSs. For the first time, we show Rep protein off-target nicking activity, highlighting the importance of the nicking substrate for Rep-mediated integration.
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Kaufer BB, Flamand L. Chromosomally integrated HHV-6: impact on virus, cell and organismal biology. Curr Opin Virol 2014; 9:111-8. [PMID: 25462442 DOI: 10.1016/j.coviro.2014.09.010] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 09/24/2014] [Accepted: 09/25/2014] [Indexed: 11/16/2022]
Abstract
HHV-6 integrates its genome into telomeres of human chromosomes. Integration can occur in somatic cells or gametes, the latter leading to individuals harboring the HHV-6 genome in every cell. This condition is transmitted to descendants and referred to as inherited chromosomally integrated human herpesvirus 6 (iciHHV-6). Although integration can occur in different chromosomes, it invariably takes place in the telomere region. This integration mechanism represents a way to maintain the virus genome during latency, which is so far unique amongst human herpesviruses. Recent work provides evidence that the integrated HHV-6 genome can be mobilized from the host chromosome, resulting in the onset of disease. Details on required structural determinants, putative integration mechanisms and biological and medical consequences of iciHHV-6 are discussed.
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Affiliation(s)
| | - Louis Flamand
- Division of Infectious and Immune Diseases, CHU de Quebec, Research Center and Department of Microbiology-Infectious Diseases and Immunology, Université Laval, Quebec, Canada.
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Liu X, Ping H, Zhang C. Rapid establishment of a HEK 293 cell line expressing FVIII-BDD using AAV site-specific integration plasmids. BMC Res Notes 2014; 7:626. [PMID: 25204455 PMCID: PMC4166473 DOI: 10.1186/1756-0500-7-626] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 09/05/2014] [Indexed: 11/14/2022] Open
Abstract
Background Stable human cell lines have gradually become the preferred system for large scale production of recombinant proteins for clinical applications because of their capacity of proper protein post-translational modification and low immunogenicity. However, human cell line development technologies are commonly based on random genome integration of protein expressing genes. It is required to screen large numbers of cell clones to identify stable high producer cell clones and the cell line development process usually takes 6 to 12 months. Adeno-associated virus type 2 (AAV2) Rep protein is known to induce rAAV DNA integration into a specific site (AAVS1) of the human chromosome 19 and integrated transgenes can stably express proteins. We take advantage of this AAV unique feature to develop a rapid protocol to clone a stable recombinant protein expression human cell line. Findings We have constructed two plasmids. One plasmid, pSVAV2, contains the AAV rep gene for the synthesis of integrase; the second plasmid, pTRP5GFPFVIII-BDD, contains B-domain-deleted factor VIII (FVIII-BDD) and GFP gene flanked by AAV ITRs. Human embryonic kidney (HEK) 293 cells were co-transfected with the two plasmids and the cells were screened by green fluorescence to establish the recombinant FVIII-BDD cell line. PCR analysis showed that the FVIII-BDD gene has been integrated into the AAVS1 site of human chromosome 19. The FVIII-BDD protein secreted into the extracellular media exhibited coagulant activity. Conclusion We developed a method of rapid establishment of human HEK 293 cell line expressing recombinant FVIII-BDD protein with AAV site-specific integration plasmids.
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Affiliation(s)
| | | | - Chun Zhang
- Suzhou Municipal Key Laboratory of Molecular Diagnostics and Therapeutics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, NO, 88 Keling Road, Suzhou New District, Suzhou 215163, P, R, China.
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Adeno-associated virus type 2 wild-type and vector-mediated genomic integration profiles of human diploid fibroblasts analyzed by third-generation PacBio DNA sequencing. J Virol 2014; 88:11253-63. [PMID: 25031342 DOI: 10.1128/jvi.01356-14] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Genome-wide analysis of adeno-associated virus (AAV) type 2 integration in HeLa cells has shown that wild-type AAV integrates at numerous genomic sites, including AAVS1 on chromosome 19q13.42. Multiple GAGY/C repeats, resembling consensus AAV Rep-binding sites are preferred, whereas rep-deficient AAV vectors (rAAV) regularly show a random integration profile. This study is the first study to analyze wild-type AAV integration in diploid human fibroblasts. Applying high-throughput third-generation PacBio-based DNA sequencing, integration profiles of wild-type AAV and rAAV are compared side by side. Bioinformatic analysis reveals that both wild-type AAV and rAAV prefer open chromatin regions. Although genomic features of AAV integration largely reproduce previous findings, the pattern of integration hot spots differs from that described in HeLa cells before. DNase-Seq data for human fibroblasts and for HeLa cells reveal variant chromatin accessibility at preferred AAV integration hot spots that correlates with variant hot spot preferences. DNase-Seq patterns of these sites in human tissues, including liver, muscle, heart, brain, skin, and embryonic stem cells further underline variant chromatin accessibility. In summary, AAV integration is dependent on cell-type-specific, variant chromatin accessibility leading to random integration profiles for rAAV, whereas wild-type AAV integration sites cluster near GAGY/C repeats. IMPORTANCE Adeno-associated virus type 2 (AAV) is assumed to establish latency by chromosomal integration of its DNA. This is the first genome-wide analysis of wild-type AAV2 integration in diploid human cells and the first to compare wild-type to recombinant AAV vector integration side by side under identical experimental conditions. Major determinants of wild-type AAV integration represent open chromatin regions with accessible consensus AAV Rep-binding sites. The variant chromatin accessibility of different human tissues or cell types will have impact on vector targeting to be considered during gene therapy.
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Zacchigna S, Zentilin L, Giacca M. Adeno-associated virus vectors as therapeutic and investigational tools in the cardiovascular system. Circ Res 2014; 114:1827-46. [PMID: 24855205 DOI: 10.1161/circresaha.114.302331] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The use of vectors based on the small parvovirus adeno-associated virus has gained significant momentum during the past decade. Their high efficiency of transduction of postmitotic tissues in vivo, such as heart, brain, and retina, renders these vectors extremely attractive for several gene therapy applications affecting these organs. Besides functional correction of different monogenic diseases, the possibility to drive efficient and persistent transgene expression in the heart offers the possibility to develop innovative therapies for prevalent conditions, such as ischemic cardiomyopathy and heart failure. Therapeutic genes are not only restricted to protein-coding complementary DNAs but also include short hairpin RNAs and microRNA genes, thus broadening the spectrum of possible applications. In addition, several spontaneous or engineered variants in the virus capsid have recently improved vector efficiency and expanded their tropism. Apart from their therapeutic potential, adeno-associated virus vectors also represent outstanding investigational tools to explore the function of individual genes or gene combinations in vivo, thus providing information that is conceptually similar to that obtained from genetically modified animals. Finally, their single-stranded DNA genome can drive homology-directed gene repair at high efficiency. Here, we review the main molecular characteristics of adeno-associated virus vectors, with a particular view to their applications in the cardiovascular field.
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Affiliation(s)
- Serena Zacchigna
- From the Molecular Medicine Laboratory, International Centre for Genetic Engineering and Biotechnology, Trieste, Italy (S.Z., L.Z., M.G.); and Department of Medical, Surgical, and Health Sciences, University of Trieste, Trieste, Italy (S.Z., M.G.)
| | - Lorena Zentilin
- From the Molecular Medicine Laboratory, International Centre for Genetic Engineering and Biotechnology, Trieste, Italy (S.Z., L.Z., M.G.); and Department of Medical, Surgical, and Health Sciences, University of Trieste, Trieste, Italy (S.Z., M.G.)
| | - Mauro Giacca
- From the Molecular Medicine Laboratory, International Centre for Genetic Engineering and Biotechnology, Trieste, Italy (S.Z., L.Z., M.G.); and Department of Medical, Surgical, and Health Sciences, University of Trieste, Trieste, Italy (S.Z., M.G.).
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39
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Osterrieder N, Wallaschek N, Kaufer BB. Herpesvirus Genome Integration into Telomeric Repeats of Host Cell Chromosomes. Annu Rev Virol 2014; 1:215-35. [PMID: 26958721 DOI: 10.1146/annurev-virology-031413-085422] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
It is well known that numerous viruses integrate their genetic material into host cell chromosomes. Human herpesvirus 6 (HHV-6) and oncogenic Marek's disease virus (MDV) have been shown to integrate their genomes into host telomeres of latently infected cells. This is unusual for herpesviruses as most maintain their genomes as circular episomes during the quiescent stage of infection. The genomic DNA of HHV-6, MDV, and several other herpesviruses harbors telomeric repeats (TMRs) that are identical to host telomere sequences (TTAGGG). At least in the case of MDV, viral TMRs facilitate integration into host telomeres. Integration of HHV-6 occurs not only in lymphocytes but also in the germline of some individuals, allowing vertical virus transmission. Although the molecular mechanism of telomere integration is poorly understood, the presence of TMRs in a number of herpesviruses suggests it is their default program for genome maintenance during latency and also allows efficient reactivation.
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Affiliation(s)
| | - Nina Wallaschek
- Institut für Virologie, Freie Universität Berlin, 14163 Berlin, Germany; ,
| | - Benedikt B Kaufer
- Institut für Virologie, Freie Universität Berlin, 14163 Berlin, Germany; ,
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40
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Janovitz T, Sadelain M, Falck-Pedersen E. Adeno-associated virus type 2 preferentially integrates single genome copies with defined breakpoints. Virol J 2014; 11:15. [PMID: 24468291 PMCID: PMC3918229 DOI: 10.1186/1743-422x-11-15] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Accepted: 01/22/2014] [Indexed: 01/05/2023] Open
Abstract
Background Adeno-associated virus (AAV) serotype 2 prevalently infects humans and is the only described eukaryotic virus that integrates site-preferentially. In a recent high throughput study, the genome wide distribution of AAV-2 integrants was determined using Integrant Capture Sequencing (IC-Seq). Additional insight regarding the integration of AAV-2 into human genomic DNA could be gleaned by low-throughput sequencing of complete viral-chromosomal junctions. Findings In this study, 140 clones derived from Integrant-Capture Sequencing were sequenced. 100 met sequence inclusion criteria, and of these 39 contained validated junction sequences. These unique sequences were analyzed to investigate the structure and location of viral-chromosomal junctions. Conclusions Overall the low-throughput analysis confirmed the genome wide distribution profile gathered through the IC-Seq analysis. We found no unidentifiable sequence inserted at AAV-2 chromosomal junctions. Assessing both left and right ends of the AAV genome, viral breakpoints predominantly occurred in one hairpin of the inverted terminal repeat and AAV genomes were preferentially integrated as single copies.
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Affiliation(s)
| | | | - Erik Falck-Pedersen
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, NY 10065, USA.
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41
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Highly divergent integration profile of adeno-associated virus serotype 5 revealed by high-throughput sequencing. J Virol 2013; 88:2481-8. [PMID: 24335317 DOI: 10.1128/jvi.03419-13] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Adeno-associated virus serotype 5 (AAV-5) is a human parvovirus that infects a high percentage of the population. It is the most divergent AAV, the DNA sequence cleaved by the viral endonuclease is distinct from all other described serotypes and, uniquely, AAV-5 does not cross-complement the replication of other serotypes. In contrast to the well-characterized integration of AAV-2, no published studies have investigated the genomic integration of AAV-5. In this study, we analyzed more than 660,000 AAV-5 integration junctions using high-throughput integrant capture sequencing of infected human cells. The integration activity of AAV-5 was 99.7% distinct from AAV-2 and favored intronic sequences. Genome-wide integration was highly correlated with viral replication protein binding and endonuclease sites, and a 39-bp consensus integration motif was revealed that included these features. Algorithmic scanning identified 126 AAV-5 hot spots, the largest of which encompassed 3.3% of all integration events. The unique aspects of AAV-5 integration may provide novel tools for biotechnology and gene therapy. IMPORTANCE Viral integration into the host genome is an important aspect of virus host cell biology. Genomic integration studies of the small single-stranded AAVs have largely focused on site preferential integration of AAV-2, which depends on the viral replication protein (Rep). We have now established the first genome wide integration profile of the highly divergent AAV-5 serotype. Using integrant capture sequencing, more than 600,000 AAV-5 integration junctions in human cells were analyzed. AAV-5 integration hot spots were 99.7% distinct from AAV-2. Integration favored intronic sequences, occurred on all chromosomes, and integration hot spot distribution was correlated with human genomic GAGC repeats and transcriptional activity. These features support expansion of AAV-5 based vectors for gene transfer considerations.
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42
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Martin J, Frederick A, Luo Y, Jackson R, Joubert M, Sol B, Poulin F, Pastor E, Armentano D, Wadsworth S, Vincent K. Generation and characterization of adeno-associated virus producer cell lines for research and preclinical vector production. Hum Gene Ther Methods 2013; 24:253-69. [PMID: 23848282 DOI: 10.1089/hgtb.2013.046] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Adeno-associated virus (AAV) producer cell lines represent an effective method for large-scale production of AAV vectors. We set out to evaluate and characterize the use of an abbreviated protocol to generate "masterwells" (MWs; a nonclonal cell population) as a platform for research and preclinical vector production. In this system, a single plasmid containing three components, the vector sequence, the AAV rep, and cap genes, and a selectable marker gene is stably transfected into HeLaS3 cells. Producer cell lines generating an AAV2 vector expressing a secreted form of human placental alkaline phosphatase (SEAP) have been created. Several MWs showed vector yields in the 5×10(4) to 2×10(5) DNase-resistant particles/cell range, and the productivity was stable over >60 population doublings. Integrated plasmid copy number in three high-producing MWs ranged from approximately 12 to 50; copies were arranged in a head-to-tail configuration. Upon infection with adenovirus, rep/cap copy number was amplified approximately 100-fold and high yield appeared to be dependent on the extent of amplification. Rep/cap gene expression and vector packaging both reached a peak at 48 hr postinfection. AAV2-SEAP vector was produced in 1-liter shaker culture and purified for assessment of vector quality and potency. The data showed that the majority of the capsids from the MWs contained vector DNA (≥70%) and that purified vector was free of replication-competent AAV. In vitro and in vivo analyses demonstrated that potency of the producer cell-derived vector was comparable to vector generated via the standard transfection method.
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Affiliation(s)
- John Martin
- Genzyme, a Sanofi company , Framingham, MA 01701-9322, USA
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Berns KI. My life with adeno-associated virus: a long time spent studying a short genome. DNA Cell Biol 2013; 32:342-7. [PMID: 23781880 DOI: 10.1089/dna.2013.2120] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
My 45 years of studying the molecular biology of adeno-associated virus are recounted. Additional activities as a mentor, department chair, and medical school administrator are described, as are my activities in the public sphere, which involved national issues related to science policy and medical education.
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Affiliation(s)
- Kenneth I Berns
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida 32608, USA.
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High-throughput sequencing reveals principles of adeno-associated virus serotype 2 integration. J Virol 2013; 87:8559-68. [PMID: 23720718 DOI: 10.1128/jvi.01135-13] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Viral integrations are important in human biology, yet genome-wide integration profiles have not been determined for many viruses. Adeno-associated virus (AAV) infects most of the human population and is a prevalent gene therapy vector. AAV integrates into the human genome with preference for a single locus, termed AAVS1. However, the genome-wide integration of AAV has not been defined, and the principles underlying this recombination remain unclear. Using a novel high-throughput approach, integrant capture sequencing, nearly 12 million AAV junctions were recovered from a human cell line, providing five orders of magnitude more data than were previously available. Forty-five percent of integrations occurred near AAVS1, and several thousand novel integration hotspots were identified computationally. Most of these occurred in genes, with dozens of hotspots targeting known oncogenes. Viral replication protein binding sites (RBS) and transcriptional activity were major factors favoring integration. In a first for eukaryotic viruses, the data reveal a unique asymmetric integration profile with distinctive directional orientation of viral genomes. These studies provide a new understanding of AAV integration biology through the use of unbiased high-throughput data acquisition and bioinformatics.
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Targeted integration of a rAAV vector into the AAVS1 region. Virology 2012; 433:356-66. [PMID: 22981435 DOI: 10.1016/j.virol.2012.08.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 05/25/2012] [Accepted: 08/03/2012] [Indexed: 11/22/2022]
Abstract
Adeno-associated virus (AAV) has been reported to integrate in a site-specific manner into chromosome 19 (a site designated AAVS1), a phenomenon that could be exploited for ex vivo targeted gene therapy. Recent studies employing LM-PCR to determine AAV integration loci; however, have, contrary to previous results with less reliable methods, concluded that the proclivity for AAV integration at AAVS1 is minimal. We tested this conclusion employing LM-PCR protocols designed to avoid bias. Hep G2 cells were infected with rAAV2-GFP and coinfected with wt AAV2 to supply Rep in trans. Sorted cells were cloned and cultured. In 26 clones that retained fluorescence, DNA was extracted and AAV-genomic junctions amplified by two LM-PCR methods. Sequencing was performed without bacterial cloning. Of these 26 clones it was possible to assign a genomic integration site to 14, of which 9 were in the AAVS1 region. In three additional clones, rAAV integration junction were to an integrated wt AAV genome while two were to an rAAV genome. We also show that integration of the AAV-GFP genome can be achieved without cointegration of the AAV genome. Based on the pattern of integrants we propose, for potential use in ex vivo targeted gene therapy, a simplified PCR method to identify clones that have rAAV genomes integrated into AAVS1.
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46
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Giacca M, Zacchigna S. Virus-mediated gene delivery for human gene therapy. J Control Release 2012; 161:377-88. [PMID: 22516095 DOI: 10.1016/j.jconrel.2012.04.008] [Citation(s) in RCA: 202] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Revised: 03/28/2012] [Accepted: 04/03/2012] [Indexed: 01/21/2023]
Abstract
After over 20 years from the first application of gene transfer in humans, gene therapy is now a mature discipline, which has progressively overcome several of the hurdles that prevented clinical success in the early stages of application. So far, the vast majority of gene therapy clinical trials have exploited viral vectors as very efficient nucleic acid delivery vehicles both in vivo and ex vivo. Here we summarize the current status of viral gene transfer for clinical applications, with special emphasis on the molecular properties of the major classes of viral vectors and the information so far obtained from gene therapy clinical trials.
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Affiliation(s)
- Mauro Giacca
- Molecular Medicine Laboratory, International Centre for Genetic Engineering and Biotechnology, Trieste, Italy.
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47
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Saydam O, Glauser DL, Fraefel C. Construction and packaging of herpes simplex virus/adeno-associated virus (HSV/AAV) Hybrid amplicon vectors. Cold Spring Harb Protoc 2012; 2012:352-6. [PMID: 22383640 DOI: 10.1101/pdb.prot068114] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Herpes simplex virus type 1 (HSV-1)-based amplicon vectors conserve most properties of the parental virus: broad host range, the ability to transduce dividing and nondiving cells, and a large transgene capacity. This permits incorporation of genomic sequences as well as cDNA, large transcriptional regulatory sequences for cell-specific expression, multiple transgene cassettes, or genetic elements from other viruses. Hybrid vectors use elements from HSV-1 that allow replication and packaging of large-vector DNA into highly infectious particles, and elements from other viruses that confer genetic stability to vector DNA in the transduced cell. For example, adeno-associated virus (AAV) has the unique ability to integrate its genome into a specific site on human chromosome 19. The viral rep gene and the inverted terminal repeats (ITRs) that flank the AAV genome are sufficient for this process. However, AAV-based vectors have a very small transgene capacity and do not conventionally contain the rep gene to support site-specific genomic integration. HSV/AAV hybrid vectors contain both HSV-1 replication and packaging functions and the AAV rep gene and a transgene cassette flanked by the AAV ITRs. This combines the large transgene capacity of HSV-1 with the capability of site-specific genomic transgene integration and long-term transgene expression of AAV. This protocol describes the preparation of HSV/AAV hybrid vectors using a replication-competent/conditional, packaging-defective HSV-1 genome cloned as a bacterial artificial chromosome (BAC) to provide helper functions for vector replication and packaging. The advantages and limitations of such vectors compared to standard HSV-1 amplicon vectors are also discussed.
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Abstract
Adeno-associated virus (AAV) was first discovered as a contaminant of adenovirus stocks in the 1960s. The development of recombinant AAV vectors (rAAV) was facilitated by early studies that generated infectious molecular clones, determined the sequence of the genome, and defined the genetic elements of the virus. The refinement of methods and protocols for the production and application of rAAV vectors has come from years of studies that explored the basic biology of this virus and its interaction with host cells. Interest in improving vector performance has in turn driven studies that have provided tremendous insights into the basic biology of the AAV lifecycle. In this chapter, we review the background on AAV biology and its exploitation for vectors and gene delivery.
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Huang S, Kawabe Y, Ito A, Kamihira M. Adeno-associated virus Rep-mediated targeting of integrase-defective retroviral vector DNA circles into human chromosome 19. Biochem Biophys Res Commun 2012; 417:78-83. [DOI: 10.1016/j.bbrc.2011.11.059] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 11/14/2011] [Indexed: 01/22/2023]
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The amino acid linker between the endonuclease and helicase domains of adeno-associated virus type 5 Rep plays a critical role in DNA-dependent oligomerization. J Virol 2011; 86:3337-46. [PMID: 22205752 DOI: 10.1128/jvi.06775-11] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The adeno-associated virus (AAV) genome encodes four Rep proteins, all of which contain an SF3 helicase domain. The larger Rep proteins, Rep78 and Rep68, are required for viral replication, whereas Rep40 and Rep52 are needed to package AAV genomes into preformed capsids; these smaller proteins are missing the site-specific DNA-binding and endonuclease domain found in Rep68/78. Other viral SF3 helicases, such as the simian virus 40 large T antigen and the papillomavirus E1 protein, are active as hexameric assemblies. However, Rep40 and Rep52 have not been observed to form stable oligomers on their own or with DNA, suggesting that important determinants of helicase multimerization lie outside the helicase domain. Here, we report that when the 23-residue linker that connects the endonuclease and helicase domains is appended to the adeno-associated virus type 5 (AAV5) helicase domain, the resulting protein forms discrete complexes on DNA consistent with single or double hexamers. The formation of these complexes does not require the Rep binding site sequence, nor is it nucleotide dependent. These complexes have stimulated ATPase and helicase activities relative to the helicase domain alone, indicating that they are catalytically relevant, a result supported by negative-stain electron microscopy images of hexameric rings. Similarly, the addition of the linker region to the AAV5 Rep endonuclease domain also confers on it the ability to bind and multimerize on nonspecific double-stranded DNA. We conclude that the linker is likely a key contributor to Rep68/78 DNA-dependent oligomerization and may play an important role in mediating Rep68/78's conversion from site-specific DNA binding to nonspecific DNA unwinding.
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