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BioDrugs : Clinical Immunotherapeutics,... Aug 2017There has been a resurgence in gene therapy efforts that is partly fueled by the identification and understanding of new gene delivery vectors. Adeno-associated virus... (Review)
Review
There has been a resurgence in gene therapy efforts that is partly fueled by the identification and understanding of new gene delivery vectors. Adeno-associated virus (AAV) is a non-enveloped virus that can be engineered to deliver DNA to target cells, and has attracted a significant amount of attention in the field, especially in clinical-stage experimental therapeutic strategies. The ability to generate recombinant AAV particles lacking any viral genes and containing DNA sequences of interest for various therapeutic applications has thus far proven to be one of the safest strategies for gene therapies. This review will provide an overview of some important factors to consider in the use of AAV as a vector for gene therapy.
Topics: Animals; Capsid; Cell Line; Dependovirus; Drug Delivery Systems; Genetic Therapy; Genetic Vectors; Humans; Insecta; Transfection
PubMed: 28669112
DOI: 10.1007/s40259-017-0234-5 -
Trends in Microbiology May 2022Adeno-associated virus (AAV) is the leading vector in emerging treatments of inherited diseases. Higher transduction efficiencies and cellular specificity are required... (Review)
Review
Adeno-associated virus (AAV) is the leading vector in emerging treatments of inherited diseases. Higher transduction efficiencies and cellular specificity are required for broader clinical application, motivating investigations of virus-host molecular interactions during cell entry. High-throughput methods are identifying host proteins more comprehensively, with subsequent molecular studies revealing unanticipated complexity and serotype specificity. Cryogenic electron microscopy (cryo-EM) provides a path towards structural details of these sometimes heterogeneous virus-host complexes, and is poised to illuminate more fully the steps in entry. Here presented, is progress in understanding the distinct steps of glycan attachment, and receptor-mediated entry/trafficking. Comparison with structures of antibody complexes provides new insights on immune neutralization with implications for the design of improved gene therapy vectors.
Topics: Dependovirus; Genetic Vectors; Polysaccharides; Receptors, Cell Surface; Serogroup; Virus Internalization
PubMed: 34711462
DOI: 10.1016/j.tim.2021.09.005 -
Molecular Therapy : the Journal of the... Sep 2006Recombinant adeno-associated viral (AAV) vectors have rapidly advanced to the forefront of gene therapy in the past decade. The exponential progress of AAV-based vectors... (Review)
Review
Recombinant adeno-associated viral (AAV) vectors have rapidly advanced to the forefront of gene therapy in the past decade. The exponential progress of AAV-based vectors has been made possible by the isolation of several naturally occurring AAV serotypes and over 100 AAV variants from different animal species. These isolates are ideally suited to development into human gene therapy vectors due to their diverse tissue tropisms and potential to evade preexisting neutralizing antibodies against the common human AAV serotype 2. Despite their prolific application in several animal models of disease, the mechanisms underlying selective tropisms of AAV serotypes remain largely unknown. Efforts to understand cell surface receptor usage and intracellular trafficking pathways exploited by AAV continue to provide significant insight into the biology of AAV vectors. Such unique traits are thought to arise from differences in surface topology of the capsids of AAV serotypes and variants. In addition to the aforementioned naturally evolved AAV isolates, several strategies to engineer hybrid AAV serotype vectors have been formulated in recent years. The generation of mosaic or chimeric vectors through the transcapsidation or marker-rescue/domain-swapping approach, respectively, is notable in this regard. More recently, combinatorial strategies for engineering AAV vectors using error-prone PCR, DNA shuffling, and other molecular cloning techniques have been established. The latter library-based approaches can serve as powerful tools in the generation of low-immunogenic and cell/tissue type-specific AAV vectors for gene delivery. This review is focused on recent developments in the isolation of novel AAV serotypes and isolates, their production and purification, diverse tissue tropisms, mechanisms of cellular entry/trafficking, and capsid structure. Strategies for engineering hybrid AAV vectors derived from AAV serotypes and potential implications of the rapidly expanding AAV vector toolkit are discussed.
Topics: Animals; Dependovirus; Genetic Engineering; Genetic Therapy; Genetic Vectors; Humans; Mice; Serotyping
PubMed: 16824801
DOI: 10.1016/j.ymthe.2006.05.009 -
Physiological Genomics Aug 2022
Topics: Dependovirus; Genetic Vectors; Transduction, Genetic
PubMed: 35816650
DOI: 10.1152/physiolgenomics.00102.2022 -
Human Gene Therapy Oct 2023For successful vector-based gene therapy manufacturing, the selected adeno-associated virus (AAV) vector production system must produce vector at sufficient scale....
For successful vector-based gene therapy manufacturing, the selected adeno-associated virus (AAV) vector production system must produce vector at sufficient scale. However, concerns have arisen regarding the quality of vector produced using different systems. In this study, we compared AAV serotypes 1, 8, and 9 produced by two different systems (Sf9/baculovirus and HEK293/transfection) and purified by two separate processes. We evaluated capsid properties, including protein composition, post-translational modification, particle content profiles, and and vector potency. Vectors produced in the Sf9/baculovirus system displayed reduced incorporation of viral protein 1 and 2 into the capsid, increased capsid protein deamidation, increased empty and partially packaged particles in vector preparations, and an overall reduced potency. The differences observed were largely independent of the harvest method and purification process. These findings illustrate the need for careful consideration when choosing an AAV vector production system for clinical production.
Topics: Humans; Capsid Proteins; Capsid; HEK293 Cells; Genetic Vectors; Dependovirus
PubMed: 37597192
DOI: 10.1089/hum.2022.116 -
Annual Review of Virology Sep 2019The recent market approvals of recombinant adeno-associated virus (rAAV) gene therapies in Europe and the United States are landmark achievements in the history of...
The recent market approvals of recombinant adeno-associated virus (rAAV) gene therapies in Europe and the United States are landmark achievements in the history of modern science. These approvals are also anticipated to herald the emergence of a new class of therapies for monogenic disorders, which had hitherto been considered untreatable. These events can be viewed as stemming from the convergence of several important historical trends: the study of basic virology, the development of genomic technologies, the imperative for translational impact of National Institutes of Health-funded research, and the development of economic models for commercialization of rare disease therapies. In this review, these historical trends are described and the key developments that have enabled clinical rAAV gene therapies are discussed, along with an overview of the current state of the field and future directions.
Topics: Animals; Clinical Trials as Topic; Dependovirus; Genetic Therapy; Genetic Vectors; History, 20th Century; History, 21st Century; Humans
PubMed: 31283441
DOI: 10.1146/annurev-virology-092818-015530 -
Molecular Therapy : the Journal of the... Sep 2022
Topics: Dependovirus; Hepatitis; Humans
PubMed: 35981546
DOI: 10.1016/j.ymthe.2022.08.001 -
Nature Reviews. Drug Discovery Mar 2023
Topics: Humans; Tropism; Gene Transfer Techniques; Dependovirus; Genetic Vectors
PubMed: 36755157
DOI: 10.1038/d41573-023-00025-9 -
Critical Reviews in Eukaryotic Gene... 2023Choice of vector is the most critical step in gene therapy. Adeno-associated viruses (AAV); third generation vectors, are getting much attention of scientists to be used...
Choice of vector is the most critical step in gene therapy. Adeno-associated viruses (AAV); third generation vectors, are getting much attention of scientists to be used as vehicles due to their non-pathogenicity, excellent safety profile, low immune responses, great efficiency to transduce non-dividing cells, large capacity to transfer genetic material and long-term expression of genetic payload. AAVs have multiple serotypes and each serotype shows tropism for a specific cell. Different serotypes are used to target liver, lungs, muscles, retina, heart, CNS, kidneys, etc. Furthermore, AAV based gene therapies have tremendous marketing applications that can be perfectly incorporated in the anticipated sites of the host target genome resulting in life long expression of transgenes. Some therapeutic products use AAV vectors that are used to treat lipoprotein lipase deficiency (LPLD) and it is injected intramuscularly, to treat mutated retinal pigment epithelium RPE65 (RPE65) that is introduced to subretinal space, an intravenous infusion to treat spinal muscular atrophy and rAAV2-CFTR vector is introduced into nasal epithelial cells to treat cystic fibrosis. AAV therapies and other such interdisciplinary methodologies can create the miracles for the generation of precision gene therapies for the treatment of most serious and sometimes fatal disorders.
Topics: Humans; Gene Transfer Techniques; Dependovirus; Genetic Vectors; Genetic Therapy; Retina
PubMed: 37522547
DOI: 10.1615/CritRevEukaryotGeneExpr.2023048135 -
Chemical Reviews Sep 2022Adeno-associated virus (AAV) has a single-stranded DNA genome encapsidated in a small icosahedrally symmetric protein shell with 60 subunits. AAV is the leading delivery... (Review)
Review
Adeno-associated virus (AAV) has a single-stranded DNA genome encapsidated in a small icosahedrally symmetric protein shell with 60 subunits. AAV is the leading delivery vector in emerging gene therapy treatments for inherited disorders, so its structure and molecular interactions with human hosts are of intense interest. A wide array of electron microscopic approaches have been used to visualize the virus and its complexes, depending on the scientific question, technology available, and amenability of the sample. Approaches range from subvolume tomographic analyses of complexes with large and flexible host proteins to detailed analysis of atomic interactions within the virus and with small ligands at resolutions as high as 1.6 Å. Analyses have led to the reclassification of glycan receptors as attachment factors, to structures with a new-found receptor protein, to identification of the epitopes of antibodies, and a new understanding of possible neutralization mechanisms. AAV is now well-enough characterized that it has also become a model system for EM methods development. Heralding a new era, cryo-EM is now also being deployed as an analytic tool in the process development and production quality control of high value pharmaceutical biologics, namely AAV vectors.
Topics: Cryoelectron Microscopy; Dependovirus; Epitopes; Genetic Therapy; Humans
PubMed: 35575684
DOI: 10.1021/acs.chemrev.1c00936