1
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Wang JH, Gessler DJ, Zhan W, Gallagher TL, Gao G. Adeno-associated virus as a delivery vector for gene therapy of human diseases. Signal Transduct Target Ther 2024; 9:78. [PMID: 38565561 PMCID: PMC10987683 DOI: 10.1038/s41392-024-01780-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 02/08/2024] [Accepted: 02/19/2024] [Indexed: 04/04/2024] Open
Abstract
Adeno-associated virus (AAV) has emerged as a pivotal delivery tool in clinical gene therapy owing to its minimal pathogenicity and ability to establish long-term gene expression in different tissues. Recombinant AAV (rAAV) has been engineered for enhanced specificity and developed as a tool for treating various diseases. However, as rAAV is being more widely used as a therapy, the increased demand has created challenges for the existing manufacturing methods. Seven rAAV-based gene therapy products have received regulatory approval, but there continue to be concerns about safely using high-dose viral therapies in humans, including immune responses and adverse effects such as genotoxicity, hepatotoxicity, thrombotic microangiopathy, and neurotoxicity. In this review, we explore AAV biology with an emphasis on current vector engineering strategies and manufacturing technologies. We discuss how rAAVs are being employed in ongoing clinical trials for ocular, neurological, metabolic, hematological, neuromuscular, and cardiovascular diseases as well as cancers. We outline immune responses triggered by rAAV, address associated side effects, and discuss strategies to mitigate these reactions. We hope that discussing recent advancements and current challenges in the field will be a helpful guide for researchers and clinicians navigating the ever-evolving landscape of rAAV-based gene therapy.
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Affiliation(s)
- Jiang-Hui Wang
- Horae Gene Therapy Center, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
- Department of Microbiology and Physiological Systems, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, 3002, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, East Melbourne, VIC, 3002, Australia
| | - Dominic J Gessler
- Horae Gene Therapy Center, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
- Department of Microbiology and Physiological Systems, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
- Department of Neurological Surgery, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
- Department of Neurosurgery, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Wei Zhan
- Horae Gene Therapy Center, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
- Department of Microbiology and Physiological Systems, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
- Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
- Li Weibo Institute for Rare Diseases Research, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
| | - Thomas L Gallagher
- Horae Gene Therapy Center, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
| | - Guangping Gao
- Horae Gene Therapy Center, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA.
- Department of Microbiology and Physiological Systems, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA.
- Li Weibo Institute for Rare Diseases Research, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA.
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2
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Klementieva NV, Lunev EA, Shmidt AA, Loseva EM, Savchenko IM, Svetlova EA, Galkin II, Polikarpova AV, Usachev EV, Vassilieva SG, Marina VI, Dzhenkova MA, Romanova AD, Agutin AV, Timakova AA, Reshetov DA, Egorova TV, Bardina MV. RNA Interference Effectors Selectively Silence the Pathogenic Variant GNAO1 c.607 G > A In Vitro. Nucleic Acid Ther 2024; 34:90-99. [PMID: 38215303 DOI: 10.1089/nat.2023.0043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2024] Open
Abstract
RNA interference (RNAi)-based therapeutics hold the potential for dominant genetic disorders, enabling sequence-specific inhibition of pathogenic gene products. We aimed to direct RNAi for the selective suppression of the heterozygous GNAO1 c.607 G > A variant causing GNAO1 encephalopathy. By screening short interfering RNA (siRNA), we showed that GNAO1 c.607G>A is a druggable target for RNAi. The si1488 candidate achieved at least twofold allelic discrimination and downregulated mutant protein to 35%. We created vectorized RNAi by incorporating the si1488 sequence into the short hairpin RNA (shRNA) in the adeno-associated virus (AAV) vector. The shRNA stem and loop were modified to improve the transcription, processing, and guide strand selection. All tested shRNA constructs demonstrated selectivity toward mutant GNAO1, while tweaking hairpin structure only marginally affected the silencing efficiency. The selectivity of shRNA-mediated silencing was confirmed in the context of AAV vector transduction. To conclude, RNAi effectors ranging from siRNA to AAV-RNAi achieve suppression of the pathogenic GNAO1 c.607G>A and discriminate alleles by the single-nucleotide substitution. For gene therapy development, it is crucial to demonstrate the benefit of these RNAi effectors in patient-specific neurons and animal models of the GNAO1 encephalopathy.
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Affiliation(s)
- Natalia V Klementieva
- Laboratory of Modeling and Gene Therapy of Hereditary Diseases, Institute of Gene Biology Russian Academy of Sciences, Moscow, Russia
- Marlin Biotech LLC, Sochi, Russia
| | - Evgenii A Lunev
- Laboratory of Modeling and Gene Therapy of Hereditary Diseases, Institute of Gene Biology Russian Academy of Sciences, Moscow, Russia
- Marlin Biotech LLC, Sochi, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Anna A Shmidt
- Laboratory of Modeling and Gene Therapy of Hereditary Diseases, Institute of Gene Biology Russian Academy of Sciences, Moscow, Russia
- Marlin Biotech LLC, Sochi, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | | | - Irina M Savchenko
- Marlin Biotech LLC, Sochi, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Ekaterina A Svetlova
- Laboratory of Modeling and Gene Therapy of Hereditary Diseases, Institute of Gene Biology Russian Academy of Sciences, Moscow, Russia
- Marlin Biotech LLC, Sochi, Russia
| | - Ivan I Galkin
- Marlin Biotech LLC, Sochi, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Anna V Polikarpova
- Laboratory of Modeling and Gene Therapy of Hereditary Diseases, Institute of Gene Biology Russian Academy of Sciences, Moscow, Russia
- Marlin Biotech LLC, Sochi, Russia
| | - Evgeny V Usachev
- Laboratory of Translational Biomedicine, Gamaleya National Research Center for Epidemiology, Moscow, Russia
| | - Svetlana G Vassilieva
- Laboratory of Modeling and Gene Therapy of Hereditary Diseases, Institute of Gene Biology Russian Academy of Sciences, Moscow, Russia
- Marlin Biotech LLC, Sochi, Russia
| | | | - Marina A Dzhenkova
- Laboratory of Modeling and Gene Therapy of Hereditary Diseases, Institute of Gene Biology Russian Academy of Sciences, Moscow, Russia
- Marlin Biotech LLC, Sochi, Russia
| | - Anna D Romanova
- Laboratory of Modeling and Gene Therapy of Hereditary Diseases, Institute of Gene Biology Russian Academy of Sciences, Moscow, Russia
| | - Anton V Agutin
- State Budgetary Healthcare Institution of Moscow Region "Balashikha Hospital," Balashikha, Russia
| | - Anna A Timakova
- Institute for Regenerative Medicine, Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | | | - Tatiana V Egorova
- Laboratory of Modeling and Gene Therapy of Hereditary Diseases, Institute of Gene Biology Russian Academy of Sciences, Moscow, Russia
- Marlin Biotech LLC, Sochi, Russia
| | - Maryana V Bardina
- Laboratory of Modeling and Gene Therapy of Hereditary Diseases, Institute of Gene Biology Russian Academy of Sciences, Moscow, Russia
- Marlin Biotech LLC, Sochi, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
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3
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Zhang J, Yu X, Chrzanowski M, Tian J, Pouchnik D, Guo P, Herzog RW, Xiao W. Thorough molecular configuration analysis of noncanonical AAV genomes in AAV vector preparations. Mol Ther Methods Clin Dev 2024; 32:101215. [PMID: 38463141 PMCID: PMC10924063 DOI: 10.1016/j.omtm.2024.101215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 02/16/2024] [Indexed: 03/12/2024]
Abstract
The unique palindromic inverted terminal repeats (ITRs) and single-stranded nature of adeno-associated virus (AAV) DNA are major hurdles to current sequencing technologies. Due to these characteristics, sequencing noncanonical AAV genomes present in AAV vector preparations remains challenging. To address this limitation, we developed thorough molecule configuration analysis of noncanonical AAV genomes (TMCA-AAV-seq). TMCA-AAV-seq takes advantage of the documented AAV packaging mechanism in which encapsidation initiates from its 3' ITR, for AAV-seq library construction. Any AAV genome with a 3' ITR is converted to a template suitable to adapter addition by a Bst DNA polymerase-mediated extension reaction. This extension reaction helps fix ITR heterogeneity in the AAV population and allows efficient adapter addition to even noncanonical AAV genomes. The resulting library maintains the original AAV genome configurations without introducing undesired changes. Subsequently, long-read sequencing can be performed by the Pacific Biosciences (PacBio) single-molecule, real-time (SMRT) sequencing technology platform. Finally, through comprehensive data analysis, we can recover canonical, noncanonical AAV DNA, and non-AAV vector DNA sequences, along with their molecular configurations. Our method is a robust tool for profiling thorough AAV-population genomes. TMCA-AAVseq can be further extended to all parvoviruses and their derivative vectors.
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Affiliation(s)
- Junping Zhang
- Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | | | | | - Jiahe Tian
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Derek Pouchnik
- School of Molecular Biosciences, Washington State University, Pullman, WA 99164-4660, USA
| | - Ping Guo
- Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Roland W. Herzog
- Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Weidong Xiao
- Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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4
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McGee AV, Liu YV, Griffith AL, Szegletes ZM, Wen B, Kraus C, Miller NW, Steger RJ, Escude Velasco B, Bosch JA, Zirin JD, Viswanatha R, Sontheimer EJ, Goodale A, Greene MA, Green TM, Doench JG. Modular vector assembly enables rapid assessment of emerging CRISPR technologies. CELL GENOMICS 2024; 4:100519. [PMID: 38484704 PMCID: PMC10943585 DOI: 10.1016/j.xgen.2024.100519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 12/31/2023] [Accepted: 02/08/2024] [Indexed: 03/19/2024]
Abstract
The diversity of CRISPR systems, coupled with scientific ingenuity, has led to an explosion of applications; however, to test newly described innovations in their model systems, researchers typically embark on cumbersome, one-off cloning projects to generate custom reagents that are optimized for their biological questions. Here, we leverage Golden Gate cloning to create the Fragmid toolkit, a modular set of CRISPR cassettes and delivery technologies, along with a web portal, resulting in a combinatorial platform that enables scalable vector assembly within days. We further demonstrate that multiple CRISPR technologies can be assessed in parallel in a pooled screening format using this resource, enabling the rapid optimization of both novel technologies and cellular models. These results establish Fragmid as a robust system for the rapid design of CRISPR vectors, and we anticipate that this assembly approach will be broadly useful for systematic development, comparison, and dissemination of CRISPR technologies.
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Affiliation(s)
- Abby V McGee
- Genetic Perturbation Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Yanjing V Liu
- Genetic Perturbation Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Audrey L Griffith
- Genetic Perturbation Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Zsofia M Szegletes
- Genetic Perturbation Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Bronte Wen
- Genetic Perturbation Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Carolyn Kraus
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Nathan W Miller
- Genetic Perturbation Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Ryan J Steger
- Genetic Perturbation Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Berta Escude Velasco
- Genetic Perturbation Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Justin A Bosch
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Jonathan D Zirin
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Raghuvir Viswanatha
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Erik J Sontheimer
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA; Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA; Li Weibo Institute for Rare Diseases Research, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Amy Goodale
- Genetic Perturbation Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Matthew A Greene
- Genetic Perturbation Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Thomas M Green
- Genetic Perturbation Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - John G Doench
- Genetic Perturbation Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
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5
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Suárez-Herrera N, Riswick IB, Vázquez-Domínguez I, Duijkers L, Karjosukarso DW, Piccolo D, Bauwens M, De Baere E, Cheetham ME, Garanto A, Collin RWJ. Proof-of-concept for multiple AON delivery by a single U7snRNA vector to restore splicing defects in ABCA4. Mol Ther 2024; 32:837-851. [PMID: 38243599 PMCID: PMC10928313 DOI: 10.1016/j.ymthe.2024.01.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 12/13/2023] [Accepted: 01/12/2024] [Indexed: 01/21/2024] Open
Abstract
The high allelic heterogeneity in Stargardt disease (STGD1) complicates the design of intervention strategies. A significant proportion of pathogenic intronic ABCA4 variants alters the pre-mRNA splicing process. Antisense oligonucleotides (AONs) are an attractive yet mutation-specific therapeutic strategy to restore these splicing defects. In this study, we experimentally assessed the potential of a splicing modulation therapy to target multiple intronic ABCA4 variants. AONs were inserted into U7snRNA gene cassettes and tested in midigene-based splice assays. Five potent antisense sequences were selected to generate a multiple U7snRNA cassette construct, and this combination vector showed substantial rescue of all of the splicing defects. Therefore, the combination cassette was used for viral synthesis and assessment in patient-derived photoreceptor precursor cells (PPCs). Simultaneous delivery of several modified U7snRNAs through a single AAV, however, did not show substantial splicing correction, probably due to suboptimal transduction efficiency in PPCs and/or a heterogeneous viral population containing incomplete AAV genomes. Overall, these data demonstrate the potential of the U7snRNA system to rescue multiple splicing defects, but also suggest that AAV-associated challenges are still a limiting step, underscoring the need for further optimization before implementing this strategy as a potential treatment for STGD1.
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Affiliation(s)
- Nuria Suárez-Herrera
- Radboud University Medical Center, Department of Human Genetics, 6525GA Nijmegen, the Netherlands
| | - Iris B Riswick
- Radboud University Medical Center, Department of Human Genetics, 6525GA Nijmegen, the Netherlands
| | - Irene Vázquez-Domínguez
- Radboud University Medical Center, Department of Human Genetics, 6525GA Nijmegen, the Netherlands
| | - Lonneke Duijkers
- Radboud University Medical Center, Department of Human Genetics, 6525GA Nijmegen, the Netherlands
| | - Dyah W Karjosukarso
- Radboud University Medical Center, Department of Human Genetics, 6525GA Nijmegen, the Netherlands
| | | | - Miriam Bauwens
- Department of Biomolecular Medicine, Ghent University, 9000 Ghent, Belgium; Center for Medical Genetics, Ghent University Hospital, 9000 Ghent, Belgium
| | - Elfride De Baere
- Department of Biomolecular Medicine, Ghent University, 9000 Ghent, Belgium; Center for Medical Genetics, Ghent University Hospital, 9000 Ghent, Belgium
| | | | - Alejandro Garanto
- Radboud University Medical Center, Department of Human Genetics, 6525GA Nijmegen, the Netherlands; Radboud University Medical Center, Amalia Children's Hospital, Department of Pediatrics, Nijmegen 6252GA, the Netherlands
| | - Rob W J Collin
- Radboud University Medical Center, Department of Human Genetics, 6525GA Nijmegen, the Netherlands.
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6
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McGee AV, Liu YV, Griffith AL, Szegletes ZM, Wen B, Kraus C, Miller NW, Steger RJ, Velasco BE, Bosch JA, Zirin JD, Viswanatha R, Sontheimer EJ, Goodale A, Greene MA, Green TM, Doench JG. Modular vector assembly enables rapid assessment of emerging CRISPR technologies. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.25.564061. [PMID: 37961518 PMCID: PMC10634825 DOI: 10.1101/2023.10.25.564061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
The diversity of CRISPR systems, coupled with scientific ingenuity, has led to an explosion of applications; however, to test newly-described innovations in their model systems, researchers typically embark on cumbersome, one-off cloning projects to generate custom reagents that are optimized for their biological questions. Here, we leverage Golden Gate cloning to create the Fragmid toolkit, a modular set of CRISPR cassettes and delivery technologies, along with a web portal, resulting in a combinatorial platform that enables scalable vector assembly within days. We further demonstrate that multiple CRISPR technologies can be assessed in parallel in a pooled screening format using this resource, enabling the rapid optimization of both novel technologies and cellular models. These results establish Fragmid as a robust system for the rapid design of CRISPR vectors, and we anticipate that this assembly approach will be broadly useful for systematic development, comparison, and dissemination of CRISPR technologies.
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Affiliation(s)
- Abby V McGee
- Genetic Perturbation Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Yanjing V Liu
- Genetic Perturbation Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Audrey L Griffith
- Genetic Perturbation Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Zsofia M Szegletes
- Genetic Perturbation Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Bronte Wen
- Genetic Perturbation Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Carolyn Kraus
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Nathan W Miller
- Genetic Perturbation Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Ryan J Steger
- Genetic Perturbation Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Berta Escude Velasco
- Genetic Perturbation Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Justin A Bosch
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Jonathan D Zirin
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Raghuvir Viswanatha
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Erik J Sontheimer
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
- Li Weibo Institute for Rare Diseases Research, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Amy Goodale
- Genetic Perturbation Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Matthew A Greene
- Genetic Perturbation Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Thomas M Green
- Genetic Perturbation Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - John G Doench
- Genetic Perturbation Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
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7
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Brimble MA, Winston SM, Davidoff AM. Stowaways in the cargo: Contaminating nucleic acids in rAAV preparations for gene therapy. Mol Ther 2023; 31:2826-2838. [PMID: 37533254 PMCID: PMC10556190 DOI: 10.1016/j.ymthe.2023.07.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 07/11/2023] [Accepted: 07/31/2023] [Indexed: 08/04/2023] Open
Abstract
Recombinant AAV (rAAV) is the most used delivery vector for clinical gene therapy. However, many issues must be addressed before safer and more widespread implementation can be achieved. At present, efficacies are highly variable across trials and patients, and immune responses after treatment are widely reported. Although rAAV is capable of directly delivering gene-encoded therapeutic sequences, increased scrutiny of viral preparations for translational use have revealed contaminating nucleic acid species packaged within rAAV preparations. The introduction of non-therapeutic nucleic acids into a recipient patient adds to the risk burden, immunogenic or otherwise, of rAAV therapies. DNA from incomplete expression cassettes, portions of plasmids or vectors used to facilitate viral replication, and production cell line genomes all have the potential to be packaged within rAAV. Here, we review what is currently known about the profile, abundance, and post-treatment consequences of nucleic acid impurities within rAAV and cover strategies that have been developed to improve rAAV purity. Furthering our understanding of these aberrantly packaged DNA species will help to ensure the continued safe implementation of rAAV therapies as the number of patients treated with this modality increases.
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Affiliation(s)
- Mark A Brimble
- Department of Immunology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA.
| | - Stephen M Winston
- Department of Surgery, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA; St. Jude Children's Research Hospital Graduate School of Biomedical Sciences, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Andrew M Davidoff
- Department of Surgery, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
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8
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Mikkelsen NS, Hernandez SS, Jensen TI, Schneller JL, Bak RO. Enrichment of transgene integrations by transient CRISPR activation of a silent reporter gene. Mol Ther Methods Clin Dev 2023; 29:1-16. [PMID: 36922985 PMCID: PMC10009645 DOI: 10.1016/j.omtm.2023.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 02/13/2023] [Indexed: 02/18/2023]
Abstract
CRISPR-Cas-mediated site-specific integration of transgenes by homology-directed repair (HDR) is challenging, especially in primary cells, where inferior editing efficiency may impede the development of gene- and cellular therapies. Various strategies for enrichment of cells with transgene integrations have been developed, but most strategies either generate unwanted genomic scars or rely on permanent integration and expression of a reporter gene used for selection. However, stable expression of a reporter gene may perturb cell homeostasis and function. Here we develop a broadly applicable and versatile enrichment strategy by harnessing the capability of CRISPR activation (CRISPRa) to transiently induce expression of a therapeutically relevant reporter gene used for immunomagnetic enrichment. This strategy is readily adaptable to primary human T cells and CD34+ hematopoietic stem and progenitor cells (HSPCs), where enrichment of 1.8- to 3.3-fold and 3.2- to 3.6-fold was achieved, respectively. Furthermore, chimeric antigen receptor (CAR) T cells were enriched 2.5-fold and demonstrated improved cytotoxicity over non-enriched CAR T cells. Analysis of HDR integrations showed a proportion of cells harboring deletions of the transgene cassette arising either from impartial HDR or truncated adeno-associated virus (AAV) vector genomes. Nonetheless, this novel enrichment strategy expands the possibility to enrich for transgene integrations in research settings and in gene and cellular therapies.
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Affiliation(s)
| | | | - Trine I Jensen
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark
| | - Jessica L Schneller
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark.,RNA and Gene Therapies, Novo Nordisk A/S, Maaloev, Denmark
| | - Rasmus O Bak
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark.,Aarhus Institute of Advanced Studies, Aarhus University, Aarhus C, Denmark
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9
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Yip M, Chen J, Zhi Y, Tran NT, Namkung S, Pastor E, Gao G, Tai PWL. Querying Recombination Junctions of Replication-Competent Adeno-Associated Viruses in Gene Therapy Vector Preparations with Single Molecule, Real-Time Sequencing. Viruses 2023; 15:1228. [PMID: 37376529 DOI: 10.3390/v15061228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 05/20/2023] [Accepted: 05/21/2023] [Indexed: 06/29/2023] Open
Abstract
Clinical-grade preparations of adeno-associated virus (AAV) vectors used for gene therapy typically undergo a series of diagnostics to determine titer, purity, homogeneity, and the presence of DNA contaminants. One type of contaminant that remains poorly investigated is replication-competent (rc)AAVs. rcAAVs form through recombination of DNA originating from production materials, yielding intact, replicative, and potentially infectious virus-like virions. They can be detected through the serial passaging of lysates from cells transduced by AAV vectors in the presence of wildtype adenovirus. Cellular lysates from the last passage are subjected to qPCR to detect the presence of the rep gene. Unfortunately, the method cannot be used to query the diversity of recombination events, nor can qPCR provide insights into how rcAAVs arise. Thus, the formation of rcAAVs through errant recombination events between ITR-flanked gene of interest (GOI) constructs and expression constructs carrying the rep-cap genes is poorly described. We have used single molecule, real-time sequencing (SMRT) to analyze virus-like genomes expanded from rcAAV-positive vector preparations. We present evidence that sequence-independent and non-homologous recombination between the ITR-bearing transgene and the rep/cap plasmid occurs under several events and rcAAVs spawn from diverse clones.
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Affiliation(s)
- Mitchell Yip
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, MA 01605, USA
| | - Jing Chen
- Spirovant Sciences, Inc., Philadelphia, PA 19104, USA
| | - Yan Zhi
- Spirovant Sciences, Inc., Philadelphia, PA 19104, USA
| | - Ngoc Tam Tran
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, MA 01605, USA
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, Worcester, MA 01605, USA
| | - Suk Namkung
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, MA 01605, USA
| | - Eric Pastor
- Spirovant Sciences, Inc., Philadelphia, PA 19104, USA
| | - Guangping Gao
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, MA 01605, USA
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, Worcester, MA 01605, USA
- Li Weibo Institute of Rare Diseases Research, UMass Chan Medical School, Worcester, MA 01605, USA
| | - Phillip W L Tai
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, MA 01605, USA
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, Worcester, MA 01605, USA
- Li Weibo Institute of Rare Diseases Research, UMass Chan Medical School, Worcester, MA 01605, USA
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10
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Barnes LF, Draper BE, Kurian J, Chen YT, Shapkina T, Powers TW, Jarrold MF. Analysis of AAV-Extracted DNA by Charge Detection Mass Spectrometry Reveals Genome Truncations. Anal Chem 2023; 95:4310-4316. [PMID: 36880264 DOI: 10.1021/acs.analchem.2c04234] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Adeno-associated virus (AAV) is a widely used gene therapy vector. The intact packaged genome is a critical quality attribute and necessary for an effective therapeutic. In this work, charge detection mass spectrometry (CDMS) was used to measure the molecular weight (MW) distribution for the genome of interest (GOI) extracted from recombinant AAV (rAAV) vectors. The measured MWs were compared to sequence masses for a range of rAAV vectors with different GOIs, serotypes, and production methods (Sf9 and HEK293 cell lines). In most cases, the measured MWs were slightly larger than the sequence masses, a result attributed to counterions. However, in a few cases, the measured MWs were significantly smaller than the sequence masses. In these cases, genome truncation is the only reasonable explanation for the discrepancy. These results suggest that direct analysis of the extracted GOI by CDMS provides a rapid and powerful tool to evaluate genome integrity in gene therapy products.
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Affiliation(s)
- Lauren F Barnes
- Chemistry Department, Indiana University, 800 E Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Benjamin E Draper
- Chemistry Department, Indiana University, 800 E Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Justin Kurian
- Analytical Research and Development, Pfizer Inc., 875 Chesterfield Pkwy. West, Chesterfield, Missouri 63017, United States
| | - Yu-Ting Chen
- Analytical Research and Development, Pfizer Inc., 875 Chesterfield Pkwy. West, Chesterfield, Missouri 63017, United States
| | - Tatiana Shapkina
- Analytical Research and Development, Pfizer Inc., 875 Chesterfield Pkwy. West, Chesterfield, Missouri 63017, United States
| | - Thomas W Powers
- Analytical Research and Development, Pfizer Inc., 875 Chesterfield Pkwy. West, Chesterfield, Missouri 63017, United States
| | - Martin F Jarrold
- Chemistry Department, Indiana University, 800 E Kirkwood Avenue, Bloomington, Indiana 47405, United States
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11
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Weinmann J, Söllner J, Abele S, Zimmermann G, Zuckschwerdt K, Mayer C, Danner-Liskus J, Peltzer A, Schuler M, Lamla T, Strobel B. Identification of Broadly Applicable Adeno-Associated Virus Vectors by Systematic Comparison of Commonly Used Capsid Variants In Vitro. Hum Gene Ther 2022; 33:1197-1212. [PMID: 36097758 PMCID: PMC9700356 DOI: 10.1089/hum.2022.109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Adeno-associated viruses (AAVs) represent highly attractive gene therapy vectors and potent research tools for the modulation of gene expression in animal models or difficult-to-transfect cell cultures. Engineered variants, comprising chimeric, mutated, or peptide-inserted capsids, have strongly broadened the utility of AAVs by altering cellular tropism, enabling immune evasion, or increasing transduction efficiency. In this work, the performance of 50 of the most used, predominantly published, AAVs was compared on several primary cells, cell lines, and induced pluripotent stem cell-derived models from different organs, including the adipose tissue, liver, lung, brain, and eyes. To identify the most efficient capsids for each cell type, self-complementary AAVs were standardized by digital polymerase chain reaction, arrayed on 96-well plates, and screened using high-content imaging. To enable best use of the data, all results are also provided in a web app. The utility of one selected AAV variant is further exemplified in a liver fibrosis assay based on primary hepatic stellate cells, where it successfully reversed a small interfering RNA (siRNA)-induced phenotype. Most importantly, our comparative analysis revealed that a subselection of only five AAV variants (AAV2.NN, AAV9-SLRSPPS, AAV6.2, AAV6TM, and AAV1P5) enabled efficient transduction of all tested cell types and markedly outperformed other well-established capsids, such as AAV2-7m8. These findings suggest that a core panel comprising these five capsid variants is a universally applicable and sufficient tool to identify potent AAVs for gene expression modulation in cellular systems.
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Affiliation(s)
- Jonas Weinmann
- Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Julia Söllner
- Translational Medicine & Clinical Pharmacology, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Sarah Abele
- Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Gudrun Zimmermann
- Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Kai Zuckschwerdt
- Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Christine Mayer
- Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Jenny Danner-Liskus
- Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Alexander Peltzer
- Translational Medicine & Clinical Pharmacology, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Michael Schuler
- Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Thorsten Lamla
- Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Benjamin Strobel
- Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany,Correspondence: Dr. Benjamin Strobel, Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str. 65, 88400 Biberach an der Riss, Germany.
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12
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DNA read count calibration for single-molecule, long-read sequencing. Sci Rep 2022; 12:17257. [PMID: 36319642 PMCID: PMC9626564 DOI: 10.1038/s41598-022-21606-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 09/29/2022] [Indexed: 11/17/2022] Open
Abstract
There are many applications in which quantitative information about DNA mixtures with different molecular lengths is important. Gene therapy vectors are much longer than can be sequenced individually via short-read NGS. However, vector preparations may contain smaller DNAs that behave differently during sequencing. We have used two library preparations each for Pacific Biosystems (PacBio) and Oxford Nanopore Technologies NGS to determine their suitability for quantitative assessment of varying sized DNAs. Equimolar length standards were generated from E. coli genomic DNA. Both PacBio library preparations provided a consistent length dependence though with a complex pattern. This method is sufficiently sensitive that differences in genomic copy number between DNA from E. coli grown in exponential and stationary phase conditions could be detected. The transposase-based Oxford Nanopore library preparation provided a predictable length dependence, but the random sequence starts caused the loss of original length information. The ligation-based approach retained length information but read frequency was more variable. Modeling of E. coli versus lambda read frequency via cubic spline smoothing showed that the shorter genome could be used as a suitable internal spike-in for DNAs in the 200 bp to 10 kb range, allowing meaningful QC to be carried out with AAV preparations.
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13
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Namkung S, Tran NT, Manokaran S, He R, Su Q, Xie J, Gao G, Tai PW. Direct ITR-to-ITR Nanopore Sequencing of AAV Vector Genomes. Hum Gene Ther 2022; 33:1187-1196. [PMID: 36178359 PMCID: PMC9700346 DOI: 10.1089/hum.2022.143] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 08/30/2022] [Indexed: 01/06/2023] Open
Abstract
Recombinant adeno-associated viruses (rAAVs) are currently the most prominently investigated vector platform for human gene therapy. The rAAV capsid serves as a potent and efficient vehicle for delivering genetic payloads into the host cell, while the vector genome determines the function and effectiveness of these biotherapies. However, current production schemes yield vectors that may consist of heterogeneous populations, compromising their potencies. The development of next-generation sequencing methods within the past few years have helped investigators profile the diversity and relative abundances of heterogenous species in vector preparations. Specifically, long-read sequencing methods, like single molecule real-time (SMRT) sequencing, have been used to uncover truncations, chimeric genomes, and inverted terminal repeat (ITR) mutations in vectors. Unfortunately, these sequencing platforms may be inaccessible to investigators with limited resources, require large amounts of input material, or may require long wait times for sequencing and analyses. Recent advances with nanopore sequencing have helped to bridge the gap for quick and relatively inexpensive long-read sequencing needs. However, their limitations and sample biases are not well-defined for sequencing rAAV. In this study, we explored the capacity for nanopore sequencing to directly interrogate rAAV content to obtain full-length resolution of encapsidated genomes. We found that the nanopore platform can cover the entirety of rAAV genomes from ITR to ITR without the need for pre-fragmentation. However, the accuracy for base calling was low, resulting in a high degree of miscalled bases and false indels. These false indels led to read-length compression; thus, assessing heterogeneity based on read length is not advisable with current nanopore technologies. Nonetheless, nanopore sequencing was able to correctly identify truncation hotspots in single-strand and self-complementary vectors similar to SMRT sequencing. In summary, nanopore sequencing can serve as a rapid and low-cost alternative for proofing AAV vectors.
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Affiliation(s)
- Suk Namkung
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, Massachusetts, USA
| | - Ngoc Tam Tran
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, Massachusetts, USA
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, Worcester, Massachusetts, USA; and
| | - Sangeetha Manokaran
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, Massachusetts, USA
| | - Ran He
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, Massachusetts, USA
| | - Qin Su
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, Massachusetts, USA
| | - Jun Xie
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, Massachusetts, USA
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, Worcester, Massachusetts, USA; and
| | - Guangping Gao
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, Massachusetts, USA
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, Worcester, Massachusetts, USA; and
- Li Weibo Institute of Rare Diseases Research, UMass Chan Medical School, Worcester, Massachusetts, USA
| | - Phillip W.L. Tai
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, Massachusetts, USA
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, Worcester, Massachusetts, USA; and
- Li Weibo Institute of Rare Diseases Research, UMass Chan Medical School, Worcester, Massachusetts, USA
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14
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Pan X, Yue Y, Boftsi M, Wasala LP, Tran NT, Zhang K, Pintel DJ, Tai PWL, Duan D. Rational engineering of a functional CpG-free ITR for AAV gene therapy. Gene Ther 2022; 29:333-345. [PMID: 34611321 PMCID: PMC8983793 DOI: 10.1038/s41434-021-00296-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 09/10/2021] [Accepted: 09/15/2021] [Indexed: 12/12/2022]
Abstract
Inverted terminal repeats (ITRs) are the only wild-type components retained in the genome of adeno-associated virus (AAV) vectors. To determine whether ITR modification is a viable approach for AAV vector engineering, we rationally deleted all CpG motifs in the ITR and examined whether CpG elimination compromises AAV-vector production and transduction. Modified ITRs were stable in the plasmid and maintained the CpG-free nature in purified vectors. Replacing the wild-type ITR with the CpG-free ITR did not affect vector genome encapsidation. However, the vector yield was decreased by approximately 3-fold due to reduced vector genome replication. To study the biological potency, we made micro-dystrophin (μDys) AAV vectors carrying either the wild-type ITR or the CpG-free ITR. We delivered the CpG-free μDys vector to one side of the tibialis anterior muscle of dystrophin-null mdx mice and the wild-type μDys vector to the contralateral side. Evaluation at four months after injection showed no difference in the vector genome copy number, microdystrophin expression, and muscle histology and force. Our results suggest that the complete elimination of the CpG motif in the ITR does not affect the biological activity of the AAV vector. CpG-free ITRs could be useful in engineering therapeutic AAV vectors.
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Affiliation(s)
- Xiufang Pan
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO, 65212, USA
| | - Yongping Yue
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO, 65212, USA
| | - Maria Boftsi
- Pathobiology Area Graduate Program, University of Missouri, Columbia, MO, 65212, USA
- Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO, 65212, USA
| | - Lakmini P Wasala
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO, 65212, USA
- Pathobiology Area Graduate Program, University of Missouri, Columbia, MO, 65212, USA
| | - Ngoc Tam Tran
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, MA, 01605, USA
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, Worcester, MA, 01605, USA
| | - Keqing Zhang
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO, 65212, USA
| | - David J Pintel
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO, 65212, USA
- Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO, 65212, USA
| | - Phillip W L Tai
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, MA, 01605, USA
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, Worcester, MA, 01605, USA
| | - Dongsheng Duan
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO, 65212, USA.
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, 65212, USA.
- Department of Neurology, School of Medicine, University of Missouri, Columbia, MO, 65212, USA.
- Department of Biomedical, Biological & Chemical Engineering, College of Engineering, University of Missouri, Columbia, MO, 65212, USA.
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15
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Himeda CL, Jones PL. FSHD Therapeutic Strategies: What Will It Take to Get to Clinic? J Pers Med 2022; 12:jpm12060865. [PMID: 35743650 PMCID: PMC9225474 DOI: 10.3390/jpm12060865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 05/17/2022] [Accepted: 05/20/2022] [Indexed: 12/10/2022] Open
Abstract
Facioscapulohumeral muscular dystrophy (FSHD) is arguably one of the most challenging genetic diseases to understand and treat. The disease is caused by epigenetic dysregulation of a macrosatellite repeat, either by contraction of the repeat or by mutations in silencing proteins. Both cases lead to chromatin relaxation and, in the context of a permissive allele, pathogenic misexpression of DUX4 in skeletal muscle. The complex nature of the locus and the fact that FSHD is a toxic, gain-of-function disease present unique challenges for the design of therapeutic strategies. There are three major DUX4-targeting avenues of therapy for FSHD: small molecules, oligonucleotide therapeutics, and CRISPR-based approaches. Here, we evaluate the preclinical progress of each avenue, and discuss efforts being made to overcome major hurdles to translation.
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16
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Wasala NB, Million ED, Watkins TB, Wasala LP, Han J, Yue Y, Lu B, Chen SJ, Hakim CH, Duan D. The gRNA Vector Level Determines the Outcome of Systemic AAV CRISPR Therapy for Duchenne Muscular Dystrophy. Hum Gene Ther 2022; 33:518-528. [PMID: 35350865 PMCID: PMC9142771 DOI: 10.1089/hum.2021.130] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 02/13/2022] [Indexed: 01/19/2023] Open
Abstract
Adeno-associated virus (AAV)-mediated clustered regularly interspaced short palindromic repeats (CRISPR) editing holds promise to restore missing dystrophin in Duchenne muscular dystrophy (DMD). Intramuscular coinjection of CRISPR-associated protein 9 (Cas9) and guide RNA (gRNA) vectors resulted in robust dystrophin restoration in short-term studies in the mdx mouse model of DMD. Intriguingly, this strategy failed to yield efficient dystrophin rescue in muscle in a long-term (18-month) systemic injection study. In-depth analyses revealed a selective loss of the gRNA vector after long-term systemic, but not short-term local injection. To determine whether preferential gRNA vector depletion is due to the mode of delivery (local vs. systemic) or the duration of the study (short term vs. long term), we conducted a short-term systemic injection study. The gRNA (4e12 vg/mouse in the 1:1 group or 1.2e13 vg/mouse in the 3:1 group) and Cas9 (4e12 vg/mouse) vectors were coinjected intravenously into 4-week-old mdx mice. The ratio of the gRNA to Cas9 vector genome copy dropped from 1:1 and 3:1 at injection to 0.4:1 and 1:1 at harvest 3 months later, suggesting that the route of administration, rather than the experimental duration, determines preferential gRNA vector loss. Consistent with our long-term systemic injection study, the vector ratio did not influence Cas9 expression. However, the 3:1 group showed significantly higher dystrophin expression and genome editing, better myofiber size distribution, and a more pronounced improvement in muscle function and electrocardiography. Our data suggest that the gRNA vector dose determines the outcome of systemic AAV CRISPR therapy for DMD.
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Affiliation(s)
- Nalinda B. Wasala
- Department of Molecular Microbiology and Immunology, The University of Missouri, Columbia, Missouri, USA
| | - Emily D. Million
- Department of Molecular Microbiology and Immunology, The University of Missouri, Columbia, Missouri, USA
| | - Thais B. Watkins
- Department of Molecular Microbiology and Immunology, The University of Missouri, Columbia, Missouri, USA
| | - Lakmini P. Wasala
- Department of Molecular Microbiology and Immunology, The University of Missouri, Columbia, Missouri, USA
| | - Jin Han
- Department of Molecular Microbiology and Immunology, The University of Missouri, Columbia, Missouri, USA
| | - Yongping Yue
- Department of Molecular Microbiology and Immunology, The University of Missouri, Columbia, Missouri, USA
| | - Baisong Lu
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA
| | - Shi-jie Chen
- Department of Physics
- Department of Biochemistry, and
- Institute for Data Science and Informatics, The University of Missouri, Columbia, Missouri, USA
| | - Chady H. Hakim
- Department of Molecular Microbiology and Immunology, The University of Missouri, Columbia, Missouri, USA
| | - Dongsheng Duan
- Department of Molecular Microbiology and Immunology, The University of Missouri, Columbia, Missouri, USA
- Departments of Neurology, School of Medicine, The University of Missouri, Columbia, Missouri, USA
- Department of Biomedical, Biological and Chemical Engineering, College of Engineering, The University of Missouri, Columbia, Missouri, USA
- Department of Biomedical Sciences, College of Veterinary Medicine, The University of Missouri, Columbia, Missouri, USA
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17
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Commentary: Multiplex dPCR and SV-AUC are Promising Assays to Robustly Monitor the Critical Quality Attribute of AAV Drug Product Integrity. J Pharm Sci 2022; 111:2143-2148. [DOI: 10.1016/j.xphs.2022.04.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 04/10/2022] [Accepted: 04/11/2022] [Indexed: 11/23/2022]
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18
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Tran NT, Lecomte E, Saleun S, Namkung S, Robin C, Weber K, Devine E, Blouin V, Adjali O, Ayuso E, Gao G, Penaud-Budloo M, Tai PW. Human and Insect Cell-Produced Recombinant Adeno-Associated Viruses Show Differences in Genome Heterogeneity. Hum Gene Ther 2022; 33:371-388. [PMID: 35293222 PMCID: PMC9063199 DOI: 10.1089/hum.2022.050] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 03/02/2022] [Indexed: 02/01/2023] Open
Abstract
In the past two decades, adeno-associated virus (AAV) vector manufacturing has made remarkable advancements to meet large-scale production demands for preclinical and clinical trials. In addition, AAV vectors have been extensively studied for their safety and efficacy. In particular, the presence of empty AAV capsids and particles containing "inaccurate" vector genomes in preparations has been a subject of concern. Several methods exist to separate empty capsids from full particles; but thus far, no single technique can produce vectors that are free of empty or partial (non-unit length) capsids. Unfortunately, the exact genome compositions of full, intermediate, and empty capsids remain largely unknown. In this work, we used AAV-genome population sequencing to explore the compositions of DNase-resistant, encapsidated vector genomes produced by two common production pipelines: plasmid transfection in human embryonic kidney cells (pTx/HEK293) and baculovirus expression vectors in Spodoptera frugiperda insect cells (rBV/Sf9). Intriguingly, our results show that vectors originating from the same construct design that were manufactured by the rBV/Sf9 system produced a higher degree of truncated and unresolved species than those generated by pTx/HEK293 production. We also demonstrate that empty particles purified by cesium chloride gradient ultracentrifugation are not truly empty but are instead packaged with genomes composed of a single truncated and/or unresolved inverted terminal repeat (ITR). Our data suggest that the frequency of these "mutated" ITRs correlates with the abundance of inaccurate genomes in all fractions. These surprising findings shed new light on vector efficacy, safety, and how clinical vectors should be quantified and evaluated.
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Affiliation(s)
- Ngoc Tam Tran
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, Massachusetts, USA
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, Worcester, Massachusetts, USA
| | - Emilie Lecomte
- INSERM UMR 1089, University of Nantes, CHU of Nantes, Nantes, France
| | - Sylvie Saleun
- INSERM UMR 1089, University of Nantes, CHU of Nantes, Nantes, France
| | - Suk Namkung
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, Massachusetts, USA
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, Worcester, Massachusetts, USA
| | - Cécile Robin
- INSERM UMR 1089, University of Nantes, CHU of Nantes, Nantes, France
| | | | - Eric Devine
- INSERM UMR 1089, University of Nantes, CHU of Nantes, Nantes, France
| | - Veronique Blouin
- INSERM UMR 1089, University of Nantes, CHU of Nantes, Nantes, France
| | - Oumeya Adjali
- INSERM UMR 1089, University of Nantes, CHU of Nantes, Nantes, France
| | - Eduard Ayuso
- INSERM UMR 1089, University of Nantes, CHU of Nantes, Nantes, France
| | - Guangping Gao
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, Massachusetts, USA
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, Worcester, Massachusetts, USA
- Li Weibo Institute of Rare Diseases Research; UMass Chan Medical School, Worcester, Massachusetts, USA
| | | | - Phillip W.L. Tai
- Horae Gene Therapy Center, UMass Chan Medical School, Worcester, Massachusetts, USA
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, Worcester, Massachusetts, USA
- Li Weibo Institute of Rare Diseases Research; UMass Chan Medical School, Worcester, Massachusetts, USA
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19
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Wörner TP, Snijder J, Friese O, Powers T, Heck AJ. Assessment of genome packaging in AAVs using Orbitrap-based charge-detection mass spectrometry. Mol Ther Methods Clin Dev 2022; 24:40-47. [PMID: 34977271 PMCID: PMC8671526 DOI: 10.1016/j.omtm.2021.11.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 11/27/2021] [Indexed: 12/31/2022]
Abstract
Adeno-associated viruses (AAVs) represent important gene therapy vectors with several approved clinical applications and numerous more in clinical trials. Genome packaging is an essential step in the bioprocessing of AAVs and needs to be tightly monitored to ensure the proper delivery of transgenes and the production of effective drugs. Current methods to monitor genome packaging have limited sensitivity, a high demand on labor, and struggle to distinguish between packaging of the intended genome or unwanted side-products. Here we show that Orbitrap-based charge-detection mass spectrometry allows the very sensitive quantification of all these different AAV bioprocessing products. A protocol is presented that allows the quantification of genome-packed AAV preparations in under half an hour, requiring only micro-liter quantities of typical AAV preparations with ∼1013 viral capsids per milliliter. The method quickly assesses the integrity and amount of genome packed AAV particles to support AAV bioprocessing and characterization of this rapidly emerging class of advanced drug therapies.
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Affiliation(s)
- Tobias P. Wörner
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Padualaan 8, 3584 CH Utrecht, the Netherlands
- Netherlands Proteomics Center, Padualaan 8, 3584 CH Utrecht, the Netherlands
| | - Joost Snijder
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Padualaan 8, 3584 CH Utrecht, the Netherlands
- Netherlands Proteomics Center, Padualaan 8, 3584 CH Utrecht, the Netherlands
| | - Olga Friese
- Biotherapeutics Pharmaceutical Sciences, Pfizer WRDM, St Louis, MO, USA
| | - Thomas Powers
- Biotherapeutics Pharmaceutical Sciences, Pfizer WRDM, St Louis, MO, USA
| | - Albert J.R. Heck
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Padualaan 8, 3584 CH Utrecht, the Netherlands
- Netherlands Proteomics Center, Padualaan 8, 3584 CH Utrecht, the Netherlands
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20
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Brimble MA, Cheng PH, Winston SM, Reeves IL, Souquette A, Spence Y, Zhou J, Wang YD, Morton CL, Valentine M, Thomas PG, Nathwani AC, Gray JT, Davidoff AM. Preventing packaging of translatable P5-associated DNA contaminants in recombinant AAV vector preps. Mol Ther Methods Clin Dev 2022; 24:280-291. [PMID: 35211640 PMCID: PMC8829444 DOI: 10.1016/j.omtm.2022.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 01/16/2022] [Indexed: 11/25/2022]
Abstract
Recombinant adeno-associated virus (rAAV) vectors are increasingly being used for clinical gene transfer and have shown great potential for the treatment of several monogenic disorders. However, contaminant DNA from producer plasmids can be packaged into rAAV alongside the intended expression cassette-containing vector genome. The consequences of this are unknown. Our analysis of rAAV preps revealed abundant contaminant sequences upstream of the AAV replication (Rep) protein driving promoter, P5, on the Rep-Cap producer plasmid. Characterization of P5-associated contaminants after infection showed transfer, persistence, and transcriptional activity in AAV-transduced murine hepatocytes, in addition to in vitro evidence suggestive of integration. These contaminants can also be efficiently translated and immunogenic, revealing previously unrecognized side effects of rAAV-mediated gene transfer. P5-associated contaminant packaging and activity were independent of an inverted terminal repeat (ITR)-flanked vector genome. To prevent incorporation of these potentially harmful sequences, we constructed a modified P5-promoter (P5-HS), inserting a DNA spacer between an Rep binding site and an Rep nicking site in P5. This prevented upstream DNA contamination regardless of transgene or AAV serotype, while maintaining vector yield. Thus, we have constructed an rAAV production plasmid that improves vector purity and can be implemented across clinical rAAV applications. These findings represent new vector safety and production considerations for rAAV gene therapy.
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Affiliation(s)
- Mark A. Brimble
- Department of Surgery, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
- Department of Haematology, University College London (UCL) Cancer Institute, London WC1E 6DD, UK
| | - Pei-Hsin Cheng
- Department of Surgery, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Stephen M. Winston
- Department of Surgery, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
- Graduate School of Biomedical Sciences, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Isaiah L. Reeves
- Department of Surgery, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
- Graduate School of Biomedical Sciences, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Aisha Souquette
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Yunyu Spence
- Department of Surgery, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Junfang Zhou
- Department of Surgery, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Yong-Dong Wang
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Christopher L. Morton
- Department of Surgery, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Marcus Valentine
- Cytogenetics Shared Resource, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Paul G. Thomas
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Amit C. Nathwani
- Department of Haematology, University College London (UCL) Cancer Institute, London WC1E 6DD, UK
- Katharine Dormandy Haemophilia and Thrombosis Centre, Royal Free Hospital, London NW3 2QG, UK
| | - John T. Gray
- Vertex Cell and Genetic Therapies, Vertex Pharmaceuticals, Boston, MA 02210, USA
| | - Andrew M. Davidoff
- Department of Surgery, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
- Graduate School of Biomedical Sciences, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
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21
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PCR-Based Analytical Methods for Quantification and Quality Control of Recombinant Adeno-Associated Viral Vector Preparations. Pharmaceuticals (Basel) 2021; 15:ph15010023. [PMID: 35056080 PMCID: PMC8779925 DOI: 10.3390/ph15010023] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 12/17/2021] [Accepted: 12/22/2021] [Indexed: 11/17/2022] Open
Abstract
Recombinant adeno-associated viral vectors (rAAV) represent a gene therapy tool of ever-increasing importance. Their utilization as a delivery vehicle for gene replacement, silencing and editing, among other purposes, demonstrate considerable versatility. Emerging vector utilization in various experimental, preclinical and clinical applications establishes the necessity of producing and characterizing a wide variety of rAAV preparations. Critically important characteristics concerning quality control are rAAV titer quantification and the detection of impurities. Differences in rAAV constructs necessitate the development of highly standardized quantification assays to make direct comparisons of different preparations in terms of assembly or purification efficiency, as well as experimental or therapeutic dosages. The development of universal methods for impurities quantification is rather complicated, since variable production platforms are utilized for rAAV assembly. However, general agreements also should be achieved to address this issue. The majority of methods for rAAV quantification and quality control are based on PCR techniques. Despite the progress made, increasing evidence concerning high variability in titration assays indicates poor standardization of the methods undertaken to date. This review summarizes successes in the field of rAAV quality control and emphasizes ongoing challenges in PCR applications for rAAV characterization. General considerations regarding possible solutions are also provided.
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22
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Zanker J, Lázaro-Petri S, Hüser D, Heilbronn R, Savy A. Insight & Development of Advanced rAAV Analysis Tools Exploiting Single Particle Quantification by Multidimensional ddPCR. Hum Gene Ther 2021; 33:977-989. [PMID: 34937401 PMCID: PMC10112877 DOI: 10.1089/hum.2021.182] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Recombinant Adeno-Associated Virus (rAAV) has become the most widely used vector in the gene therapy field with hundreds of clinical trials ongoing and already several products on the market. AAV's physico-chemical stability, and the various natural and engineered serotypes allow for targeting a broad range of cell types and tissue by diverse routes of administration. Progressing from early clinical studies to eventual market approval, many critical quality attributes (CQAs) have to be defined and reproducibly quantified, such as AAV stability, purity, aggregates, empty/full particles ratio and rAAV genome titration. Droplet digital PCR (ddPCR) is becoming the tool of choice to perform absolute quantification of rAAV genomes. In the present study, we have identified critical parameters that could impact AAV titration and characterization accuracy, such as Poisson distribution confidence interval, primers/probe position and potential aggregates. Our work presents how ddPCR can help to better characterize AAV vectors on the single particle level and highlights challenges that we are facing today in term of AAV titration.
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Affiliation(s)
- Jeanette Zanker
- Charité Universitätsmedizin Berlin Campus Benjamin Franklin, 9164, Institute of Health, Department of Neurology, AG Gene Therapy, Berlin, Berlin, Germany;
| | - Sara Lázaro-Petri
- Charité Universitätsmedizin Berlin Campus Benjamin Franklin, 9164, Institute of Health, Department of Neurology, AG Gene Therapy, Berlin, Berlin, Germany;
| | - Daniela Hüser
- Charité Universitätsmedizin Berlin Campus Benjamin Franklin, 9164, Institute of Health, Department of Neurology, AG Gene Therapy, Berlin, Berlin, Germany;
| | - Regine Heilbronn
- Charité Universitätsmedizin Berlin Campus Benjamin Franklin, 9164, Institute of Health, Department of Neurology, AG Gene Therapy, Berlin, Berlin, Germany;
| | - Adrien Savy
- Charité Universitätsmedizin Berlin Campus Benjamin Franklin, 9164, Institute of Health, Department of Neurology, AG Gene Therapy, Berlin, Berlin, Germany.,Kolibri, BioProcess, Paris, France;
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23
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PALAZZI X, Pardo I, Sirivelu M, Newman L, Kumpf S, Qian J, Franks T, Lopes S, Liu J, Monarski L, Casinghino S, Ritenour C, Ritenour H, Dubois C, Olson J, Graves J, Alexander K, Coskran T, Lanz TA, Brady J, McCarty D, Somanathan S, Whiteley L. Biodistribution and Tolerability of AAV-PHP.B-CBh-SMN1 in Wistar Han Rats and Cynomolgus Macaques Reveal Different Toxicologic Profiles. Hum Gene Ther 2021; 33:175-187. [PMID: 34931542 PMCID: PMC8885435 DOI: 10.1089/hum.2021.116] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Recombinant adeno-associated viruses (AAVs) have emerged as promising vectors for human gene therapy, but some variants have induced severe toxicity in Rhesus monkeys and piglets following high-dose intravenous (IV) administration. To characterize biodistribution, transduction, and toxicity among common preclinical species, an AAV9 neurotropic variant expressing the survival motor neuron 1 (SMN1) transgene (AAV-PHP.B-CBh-SMN1) was administered by IV bolus injection to Wistar Han rats and cynomolgus monkeys at doses of 2 × 1013, 5 × 1013, or 1 × 1014 vg/kg. A dose-dependent degeneration/necrosis of neurons without clinical manifestations occurred in dorsal root ganglia (DRGs) and sympathetic thoracic ganglia in rats, while liver injury was not observed in rats. In monkeys, one male at 5 × 1013 vg/kg was found dead on day 4. Clinical pathology data on days 3 and/or 4 at all doses suggested liver dysfunction and coagulation disorders, which led to study termination. Histologic evaluation of the liver in monkeys showed hepatocyte degeneration and necrosis without inflammatory cell infiltrates or intravascular thrombi, suggesting that hepatocyte injury is a direct effect of the vector following hepatocyte transduction. In situ hybridization demonstrated a dose-dependent expression of SMN1 transgene mRNA in the cytoplasm and DNA in the nucleus of periportal to panlobular hepatocytes, while quantitative polymerase chain reaction confirmed the dose-dependent presence of SMN1 transgene mRNA and DNA in monkeys. Monkeys produced a much greater amount of transgene mRNA compared with rats. In DRGs, neuronal degeneration/necrosis and accompanying findings were observed in monkeys as early as 4 days after test article administration. The present results show sensory neuron toxicity following IV delivery of AAV vectors at high doses with an early onset in Macaca fascicularis and after 1 month in rats, and suggest adding the autonomic system in the watch list for preclinical and clinical studies. Our data also suggest that the rat may be useful for evaluating the potential DRG toxicity of AAV vectors, while acute hepatic toxicity associated with coagulation disorders appears to be highly species-dependent.
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Affiliation(s)
- Xavier PALAZZI
- Pfizer Global Research and Development, 105623, 1, Eastern Point Road, Groton, Connecticut, United States, 06340
| | - Ingrid Pardo
- Pfizer Global Research and Development, 105623, Groton, Connecticut, United States
| | - Madhu Sirivelu
- Pfizer Worldwide Research Development and Medicine, Drug Safety Research and Development, Cambridge, Massachusetts, United States
| | - Leah Newman
- Pfizer Global Research and Development, 105623, Groton, Connecticut, United States
| | - Steven Kumpf
- Pfizer Global Research and Development, 105623, Groton, Connecticut, United States
| | - Jessie Qian
- Pfizer Global Research and Development, 105623, Groton, Connecticut, United States
| | - Tania Franks
- Pfizer Global Research and Development, 105623, Groton, Connecticut, United States
| | - Sarah Lopes
- Pfizer Global Research and Development, 105623, Groton, Connecticut, United States
| | - June Liu
- Pfizer Global Research and Development, 105623, Groton, Connecticut, United States
| | - Laura Monarski
- Pfizer Global Research and Development, 105623, Groton, Connecticut, United States
| | - Sandra Casinghino
- Pfizer Global Research and Development, 105623, Groton, Connecticut, United States
| | - Casey Ritenour
- Pfizer Global Research and Development, 105623, Groton, Connecticut, United States
| | - Hayley Ritenour
- Pfizer Global Research and Development, 105623, Groton, Connecticut, United States
| | - Christopher Dubois
- Pfizer Global Research and Development, 105623, Groton, Connecticut, United States
| | - Jennifer Olson
- Pfizer Global Research and Development, 105623, Groton, Connecticut, United States
| | - John Graves
- Pfizer Global Research and Development, 105623, Groton, Connecticut, United States
| | - Kristin Alexander
- Pfizer Global Research and Development, 105623, Groton, Connecticut, United States
| | - Timothy Coskran
- Pfizer Global Research and Development, 105623, Groton, Connecticut, United States
| | - Thomas A Lanz
- Pfizer Global Research and Development, 105623, Groton, Connecticut, United States
| | - Joseph Brady
- Pfizer Worldwide Research Development and Medicine, Drug Safety Research and Development, Cambridge, Massachusetts, United States
| | - Douglas McCarty
- Pfizer Worldwide Research Development and Medicine, Drug Safety Research and Development, Cambridge, Massachusetts, United States
| | - Suryanarayan Somanathan
- Pfizer Worldwide Research Development and Medicine, Drug Safety Research and Development, Cambridge, Massachusetts, United States
| | - Laurence Whiteley
- Pfizer Worldwide Research Development and Medicine, Drug Safety Research and Development, Cambridge, Massachusetts, United States
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24
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Overview of analytics needed to support a robust gene therapy manufacturing process. CURRENT OPINION IN BIOMEDICAL ENGINEERING 2021. [DOI: 10.1016/j.cobme.2021.100339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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25
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Self-inactivating, all-in-one AAV vectors for precision Cas9 genome editing via homology-directed repair in vivo. Nat Commun 2021; 12:6267. [PMID: 34725353 PMCID: PMC8560862 DOI: 10.1038/s41467-021-26518-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 10/06/2021] [Indexed: 12/26/2022] Open
Abstract
Adeno-associated virus (AAV) vectors are important delivery platforms for therapeutic genome editing but are severely constrained by cargo limits. Simultaneous delivery of multiple vectors can limit dose and efficacy and increase safety risks. Here, we describe single-vector, ~4.8-kb AAV platforms that express Nme2Cas9 and either two sgRNAs for segmental deletions, or a single sgRNA with a homology-directed repair (HDR) template. We also use anti-CRISPR proteins to enable production of vectors that self-inactivate via Nme2Cas9 cleavage. We further introduce a nanopore-based sequencing platform that is designed to profile rAAV genomes and serves as a quality control measure for vector homogeneity. We demonstrate that these platforms can effectively treat two disease models [type I hereditary tyrosinemia (HT-I) and mucopolysaccharidosis type I (MPS-I)] in mice by HDR-based correction of the disease allele. These results will enable the engineering of single-vector AAVs that can achieve diverse therapeutic genome editing outcomes. Long-term expression of Cas9 following precision genome editing in vivo may lead to undesirable consequences. Here we show that a single-vector, self-inactivating AAV system containing Cas9 nuclease, guide, and DNA donor can use homology-directed repair to correct disease mutations in vivo.
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26
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Zhang J, Yu X, Guo P, Firrman J, Pouchnik D, Diao Y, Samulski RJ, Xiao W. Satellite Subgenomic Particles Are Key Regulators of Adeno-Associated Virus Life Cycle. Viruses 2021; 13:v13061185. [PMID: 34205760 PMCID: PMC8235507 DOI: 10.3390/v13061185] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 06/16/2021] [Accepted: 06/17/2021] [Indexed: 11/22/2022] Open
Abstract
Historically, adeno-associated virus (AAV)-defective interfering particles (DI) were known as abnormal virions arising from natural replication and encapsidation errors. Through single virion genome analysis, we revealed that a major category of DI particles contains a double-stranded DNA genome in a “snapback” configuration. The 5′- snapback genomes (SBGs) include the P5 promoters and partial rep gene sequences. The 3′-SBGs contains the capsid region. The molecular configuration of 5′-SBGs theoretically may allow double-stranded RNA transcription in their dimer configuration. Our studies demonstrated that 5-SBG regulated AAV rep expression and improved AAV packaging. In contrast, 3′-SBGs at its dimer configuration increased levels of cap protein. The generation and accumulation of 5′-SBGs and 3′-SBGs appears to be coordinated to balance the viral gene expression level. Therefore, the functions of 5′-SBGs and 3′-SBGs may help maximize the yield of AAV progenies. We postulate that AAV virus population behaved as a colony and utilizes its subgenomic particles to overcome the size limit of a viral genome and encodes additional essential functions.
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Affiliation(s)
- Junping Zhang
- School of Medicine, Huaqiao University, Quanzhou 362021, China; (J.Z.); (X.Y.); (P.G.); (Y.D.)
| | - Xiangping Yu
- School of Medicine, Huaqiao University, Quanzhou 362021, China; (J.Z.); (X.Y.); (P.G.); (Y.D.)
| | - Ping Guo
- School of Medicine, Huaqiao University, Quanzhou 362021, China; (J.Z.); (X.Y.); (P.G.); (Y.D.)
| | - Jenni Firrman
- Dairy and Functional Foods Research Unit, Eastern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Wyndmoor, PA 19038, USA;
| | - Derek Pouchnik
- School of Molecular Biosciences, Washington State University, Pullman, WA 99164, USA;
| | - Yong Diao
- School of Medicine, Huaqiao University, Quanzhou 362021, China; (J.Z.); (X.Y.); (P.G.); (Y.D.)
| | - Richard Jude Samulski
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Correspondence: (R.J.S.); (W.X.)
| | - Weidong Xiao
- Herman B Wells Center for Pediatric Research, Indiana University, Indianapolis, IN 46202, USA
- Correspondence: (R.J.S.); (W.X.)
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27
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Dudek AM, Porteus MH. Answered and Unanswered Questions in Early-Stage Viral Vector Transduction Biology and Innate Primary Cell Toxicity for Ex-Vivo Gene Editing. Front Immunol 2021; 12:660302. [PMID: 34122418 PMCID: PMC8195279 DOI: 10.3389/fimmu.2021.660302] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 05/04/2021] [Indexed: 01/07/2023] Open
Abstract
Adeno-associated virus is a highly efficient DNA delivery vehicle for genome editing strategies that employ CRISPR/Cas9 and a DNA donor for homology-directed repair. Many groups have used this strategy in development of therapies for blood and immune disorders such as sickle-cell anemia and severe-combined immunodeficiency. However, recent events have called into question the immunogenicity of AAV as a gene therapy vector and the safety profile dictated by the immune response to this vector. The target cells dictating this response and the molecular mechanisms dictating cellular response to AAV are poorly understood. Here, we will investigate the current known AAV capsid and genome interactions with cellular proteins during early stage vector transduction and how these interactions may influence innate cellular responses. We will discuss the current understanding of innate immune activation and DNA damage response to AAV, and the limitations of what is currently known. In particular, we will focus on pathway differences in cell line verses primary cells, with a focus on hematopoietic stem and progenitor cells (HSPCs) in the context of ex-vivo gene editing, and what we can learn from HSPC infection by other parvoviruses. Finally, we will discuss how innate immune and DNA damage response pathway activation in these highly sensitive stem cell populations may impact long-term engraftment and clinical outcomes as these gene-editing strategies move towards the clinic, with the aim to propose pathways relevant for improved hematopoietic stem cell survival and long-term engraftment after AAV-mediated genome editing.
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Affiliation(s)
- Amanda Mary Dudek
- Department of Pediatrics, Stanford University, Stanford, CA, United States.,Department of Pediatrics, School of Medicine, Stanford University, Palo Alto, CA, United States
| | - Matthew Hebden Porteus
- Department of Pediatrics, Stanford University, Stanford, CA, United States.,Department of Pediatrics, School of Medicine, Stanford University, Palo Alto, CA, United States
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28
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Lek A, Ma K, Woodman KG, Lek M. Nuclease-Deficient Clustered Regularly Interspaced Short Palindromic Repeat-Based Approaches for In Vitro and In Vivo Gene Activation. Hum Gene Ther 2021; 32:260-274. [PMID: 33446040 DOI: 10.1089/hum.2020.241] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Clustered regularly interspaced short palindromic repeat (CRISPR)-based technology has been adapted to achieve a wide range of genome modifications, including transcription regulation. The focus of this review is on the application of CRISPR-based platforms such as nuclease-deficient Cas9 and Cas12a, to achieve targeted gene activation. We review studies to date that have used CRISPR-based activation technology for the elucidation of biological mechanism and disease correction, as well as its application in genetic screens as a powerful tool for high-throughput genotype-phenotype mapping. In addition to our synthesis and critical analysis of published studies, we explore key considerations for the potential clinical translation of CRISPR-based activation technology.
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Affiliation(s)
- Angela Lek
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut, USA
| | - Kaiyue Ma
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut, USA
| | - Keryn G Woodman
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut, USA
| | - Monkol Lek
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut, USA
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29
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Affiliation(s)
- Charles P Venditti
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA.
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