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Current Opinion in Virology Dec 2016Recombinant adeno-associated viral vectors (rAAV) are regarded as promising vehicles for therapeutic gene delivery. Continued development and new strategies are... (Review)
Review
Recombinant adeno-associated viral vectors (rAAV) are regarded as promising vehicles for therapeutic gene delivery. Continued development and new strategies are essential to improve the potency of AAV vectors and reduce the effective dose needed for clinical efficacy. In this regard, many studies have focused on understanding the cellular transduction mechanisms of rAAV, often with the goal of exploiting this knowledge to increase gene transfer efficiency. Here, we provide an overview of our evolving understanding of rAAV cellular trafficking pathways through the host cell, beginning with cellular entry and ending with transcription of the vector genome. Strategies to exploit this information for improving rAAV transduction are discussed.
Topics: Dependovirus; Drug Delivery Systems; Genetic Therapy; Genetic Vectors; Humans; Transduction, Genetic
PubMed: 27544821
DOI: 10.1016/j.coviro.2016.08.001 -
Biotechnology Advances 2024Recombinant adeno-associated viruses (rAAVs) stand at the forefront of gene therapy applications, holding immense significance for their safe and efficient gene delivery... (Review)
Review
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.
Topics: Dependovirus; Animals; Genetic Vectors; Humans; Genetic Therapy
PubMed: 38692443
DOI: 10.1016/j.biotechadv.2024.108370 -
Current Opinion in Virology Jun 2017Viral vectors based on adeno-associated virus (AAV) are leading candidates for therapeutic gene delivery. Understanding rate-limiting steps in the entry of AAV vectors... (Review)
Review
Viral vectors based on adeno-associated virus (AAV) are leading candidates for therapeutic gene delivery. Understanding rate-limiting steps in the entry of AAV vectors may be used in a rational approach to improve efficiency and specificity of transduction. This review describes our current understanding of AAV entry, a key step during infection. We discuss the identity and functions of AAV receptors and attachment factors, including the recently discovered multi-serotype receptor AAVR. We further provide an overview of other host factors that act during the trafficking stage of AAV vector transduction. In particular, we focus on cellular protein complexes associated with retrograde transport from endosomes to the trans-Golgi network. The novel insights in AAV-host interactions facilitated by technological advances in genetic screening approaches provide a greater depth in our understanding how AAV vectors exploit host factors to deliver its genetic cargo to the nucleus.
Topics: Animals; Biological Transport; Dependovirus; Genetic Vectors; Golgi Apparatus; Host-Pathogen Interactions; Humans; Mice; Polysaccharides; Serogroup; Transduction, Genetic; Virus Internalization
PubMed: 28672171
DOI: 10.1016/j.coviro.2017.06.003 -
Human Gene Therapy Jun 2019Traditional gene therapy (gene replacement) has made a breakthrough in treating inherited diseases. Adeno-associated virus (AAV) has emerged as a highly promising vector... (Review)
Review
Traditional gene therapy (gene replacement) has made a breakthrough in treating inherited diseases. Adeno-associated virus (AAV) has emerged as a highly promising vector with innate ability, boosting the development of gene replacement and gene targeting. With the recent advance of engineered nucleases that work efficiently in human cells, AAV mediated-genome editing with nucleases has raised hopes for gene therapy of inherited and non-inherited diseases. Here, the applications of AAV-mediated genome editing are highlighted, and the prospect of AAV and nucleases that will render extension of such success in clinical gene therapy is discussed.
Topics: Animals; Dependovirus; Endonucleases; Gene Editing; Gene Expression Regulation, Viral; Genetic Vectors; Genome, Human; Genomics; Humans; Virus Integration
PubMed: 30588843
DOI: 10.1089/hum.2018.190 -
Pharmaceutical Research Dec 2018A resurgence of interest and investment in the field of gene therapy, driven in large part by advances in viral vector technology, has recently culminated in United... (Review)
Review
A resurgence of interest and investment in the field of gene therapy, driven in large part by advances in viral vector technology, has recently culminated in United States Food and Drug Administration approval of the first gene therapy product targeting a disease caused by mutations in a single gene. This product, LUXTURNA™ (voretigene neparvovec-rzyl; Spark Therapeutics, Inc., Philadelphia, PA), delivers a normal copy of the RPE65 gene to retinal cells for the treatment of biallelic RPE65 mutation-associated retinal dystrophy, a blinding disease. Many additional gene therapy programs targeting both inherited retinal diseases and other ocular diseases are in development, owing to an improved understanding of the genetic basis of ocular disease and the unique properties of the ocular compartment that make it amenable to local gene therapy. Here we review the growing body of literature that describes both the design and development of ocular gene therapy products, with a particular emphasis on target and vector selection, and chemistry, manufacturing, and controls.
Topics: Animals; Dependovirus; Drug Compounding; Drug Development; Gene Transfer Techniques; Genetic Therapy; Genetic Vectors; Humans; Macular Degeneration; Retinal Diseases
PubMed: 30591984
DOI: 10.1007/s11095-018-2554-7 -
Hearing Research Jan 2022Owing to the advances in transgenic animal technology and the advent of the next-generation sequencing era, over 120 genes causing hereditary hearing loss have been... (Review)
Review
Owing to the advances in transgenic animal technology and the advent of the next-generation sequencing era, over 120 genes causing hereditary hearing loss have been identified by now. In parallel, the field of human gene therapy continues to make exciting and rapid progress, culminating in the recent approval of several ex vivo and in vivo applications. Despite these encouraging developments and the growing interest in causative treatments for hearing disorders, gene therapeutic interventions in the inner ear remain in their infancy and await clinical translation. This review focuses on the adeno-associated virus (AAV), which nowadays represents one of the safest and most promising vectors in gene therapy. We first provide an overview of AAV biology and outline the principles of therapeutic gene transfer with recombinant AAV vectors, before pointing out major challenges and solutions for clinical translation including vector manufacturing and species translatability. Finally, we highlight seminal technologies for engineering and selection of next-generation "designer" AAV capsids, and illustrate their power and potential with recent examples of their application for inner ear gene transfer in animals.
Topics: Animals; Capsid; Dependovirus; Gene Transfer Techniques; Genetic Therapy; Genetic Vectors; Hearing Disorders
PubMed: 33268240
DOI: 10.1016/j.heares.2020.108092 -
Current Opinion in Neurobiology Jun 2018Optimization of traditional replication-competent viral tracers has granted access to immediate synaptic partners of target neuronal populations, enabling the dissection... (Review)
Review
Optimization of traditional replication-competent viral tracers has granted access to immediate synaptic partners of target neuronal populations, enabling the dissection of complex brain circuits into functional neural pathways. The excessive virulence of most conventional tracers, however, impedes their utility in revealing and genetically perturbing cellular function on long time scales. As a promising alternative, the natural capacity of adeno-associated viral (AAV) vectors to safely mediate persistent and robust gene expression has stimulated strong interest in adapting them for sparse neuronal labeling and physiological studies. Furthermore, increasingly refined engineering strategies have yielded novel AAV variants with enhanced target specificity, transduction, and retrograde trafficking in the CNS. These potent vectors offer new opportunities for characterizing the identity and connectivity of single neurons within immense networks and modulating their activity via robust delivery of functional genetic tools.
Topics: Animals; Dependovirus; Genetic Vectors; Humans; Neural Pathways; Protein Engineering; Protein Transport
PubMed: 29614429
DOI: 10.1016/j.conb.2017.12.011 -
Drug Discovery Today Jan 2023The characterization of adeno-associated virus (AAV)-based gene therapy products represents significant challenges owing to their extremely large molecular sizes,... (Review)
Review
The characterization of adeno-associated virus (AAV)-based gene therapy products represents significant challenges owing to their extremely large molecular sizes, structural complexity and heterogeneity, and limited sample amounts. Mass spectrometry (MS) is one of the key analytical tools that can overcome these challenges and serve as an important technique for the analysis of multiple attributes. In this review, the current methodologies and emerging trends in MS analysis of AAV gene therapy products are presented, highlighting their advantages and unique capabilities in addressing key issues encountered in intact AAV vector analysis, capsid viral protein characterization and impurity analysis.
Topics: Dependovirus; Capsid Proteins; Capsid; Genetic Therapy; Mass Spectrometry; Genetic Vectors
PubMed: 36396118
DOI: 10.1016/j.drudis.2022.103442 -
Annual Review of Neuroscience Jul 2018Recombinant viruses allow for targeted transgene expression in specific cell populations throughout the nervous system. The adeno-associated virus (AAV) is among the... (Review)
Review
Recombinant viruses allow for targeted transgene expression in specific cell populations throughout the nervous system. The adeno-associated virus (AAV) is among the most commonly used viruses for neuroscience research. Recombinant AAVs (rAAVs) are highly versatile and can package most cargo composed of desired genes within the capsid's ∼5-kb carrying capacity. Numerous regulatory elements and intersectional strategies have been validated in rAAVs to enable cell type-specific expression. rAAVs can be delivered to specific neuronal populations or globally throughout the animal. The AAV capsids have natural cell type or tissue tropism and trafficking that can be modified for increased specificity. Here, we describe recently engineered AAV capsids and associated cargo that have extended the utility of AAVs in targeting molecularly defined neurons throughout the nervous system, which will further facilitate neuronal circuit interrogation and discovery.
Topics: Animals; Central Nervous System; Dependovirus; Genetic Engineering; Humans; Peripheral Nervous System
PubMed: 29709207
DOI: 10.1146/annurev-neuro-080317-062048 -
Expert Opinion on Biological Therapy Jun 2021Gene therapy clinical trials with adeno-associated virus (AAV) vectors report impressive clinical efficacy data. Nevertheless, challenges have become apparent, such as... (Review)
Review
Gene therapy clinical trials with adeno-associated virus (AAV) vectors report impressive clinical efficacy data. Nevertheless, challenges have become apparent, such as the need for high vector doses and the induction of anti-AAV immune responses that cause the loss of vector-transduced hepatocytes. This fostered research focusing on development of next-generation AAV vectors capable of dealing with these hurdles. While both the viral vector genome and the capsid are subjects to engineering, this review focuses on the latter. Specifically, we summarize the principles of capsid engineering strategies, and describe developments and applications of engineered capsid variants for liver-directed gene therapy. Capsid engineering is a promising strategy to significantly improve efficacy of the AAV vector system in clinical application. Reduction in vector dose will further improve vector safety, lower the risk of host immune responses and the cost of manufacturing. Capsid engineering is also expected to result in AAV vectors applicable to patients with preexisting immunity toward natural AAV serotypes.
Topics: Capsid; Dependovirus; Genetic Therapy; Genetic Vectors; Humans; Liver
PubMed: 33331201
DOI: 10.1080/14712598.2021.1865303