1
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Gau D, Daoud A, Allen A, Joy M, Sagan A, Lee S, Lucas PC, Duensing S, Boone D, Osmanbeyoglu HU, Roy P. Vascular endothelial profilin-1 drives a protumorigenic tumor microenvironment and tumor progression in renal cancer. J Biol Chem 2023; 299:105044. [PMID: 37451478 PMCID: PMC10432806 DOI: 10.1016/j.jbc.2023.105044] [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: 04/18/2023] [Revised: 07/06/2023] [Accepted: 07/09/2023] [Indexed: 07/18/2023] Open
Abstract
Overexpression of actin-binding protein profilin-1 (Pfn1) correlates with advanced disease features and adverse clinical outcome of patients with clear cell renal carcinoma, the most prevalent form of renal cancer. We previously reported that Pfn1 is predominantly overexpressed in tumor-associated vascular endothelial cells in human clear cell renal carcinoma. In this study, we combined in vivo strategies involving endothelial cell-specific depletion and overexpression of Pfn1 to demonstrate a role of vascular endothelial Pfn1 in promoting tumorigenicity and enabling progressive growth and metastasis of renal carcinoma cells in a syngeneic orthotopic mouse model of kidney cancer. We established an important role of endothelial Pfn1 in tumor angiogenesis and further identified endothelial Pfn1-dependent regulation of several pro- (VEGF, SERPINE1, CCL2) and anti-angiogenic factors (platelet factor 4) in vivo. Endothelial Pfn1 overexpression increases tumor infiltration by macrophages and concomitantly diminishes tumor infiltration by T cells including CD8+ T cells in vivo, correlating with the pattern of endothelial Pfn1-dependent changes in tumor abundance of several prominent immunomodulatory cytokines. These data were also corroborated by multiplexed quantitative immunohistochemistry and immune deconvolution analyses of RNA-seq data of clinical samples. Guided by Upstream Regulator Analysis of tumor transcriptome data, we further established endothelial Pfn1-induced Hif1α elevation and suppression of STAT1 activation. In conclusion, this study demonstrates for the first time a direct causal relationship between vascular endothelial Pfn1 dysregulation, immunosuppressive tumor microenvironment, and disease progression with mechanistic insights in kidney cancer. Our study also provides a conceptual basis for targeting Pfn1 for therapeutic benefit in kidney cancer.
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Affiliation(s)
- David Gau
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
| | - Andrew Daoud
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Abigail Allen
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Marion Joy
- UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - April Sagan
- UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Department of Biomedical Informatics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Sanghoon Lee
- UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Department of Biomedical Informatics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Peter C Lucas
- UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Stefan Duensing
- Department of Urology, University of Heidelberg School of Medicine, Heidelberg, Germany
| | - David Boone
- Department of Biomedical Informatics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Hatice U Osmanbeyoglu
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Department of Biomedical Informatics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Department of Biostatistics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Partha Roy
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
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2
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Periasamy R, Patel DD, Boye SL, Boye SE, Lipinski DM. Improving retinal vascular endothelial cell tropism through rational rAAV capsid design. PLoS One 2023; 18:e0285370. [PMID: 37167304 PMCID: PMC10174500 DOI: 10.1371/journal.pone.0285370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 04/21/2023] [Indexed: 05/13/2023] Open
Abstract
Vascular endothelial cells (VEC) are essential for retinal homeostasis and their dysfunction underlies pathogenesis in diabetic retinopathy (DR) and exudative age-related macular degeneration (AMD). Studies have shown that recombinant adeno-associated virus (rAAV) vectors are effective at delivering new genetic material to neural and glial cells within the retina, but targeting VECs remains challenging. To overcome this limitation, herein we developed rAAV capsid mutant vectors with improved tropism towards retinal VEC. rAAV2/2, 2/2[QuadYF-TV], and rAAV2/9 serotype vectors (n = 9, capsid mutants per serotype) expressing GFP were generated by inserting heptameric peptides (7AA) designed to increase endothelial targeting at positions 588 (2/2 and 2/2[QuadYF-TV] or 589 (2/9) of the virus protein (VP 1-3). The packaging and transduction efficiency of the vectors were assessed in HEK293T and bovine VECs using Fluorescence microscopy and flow cytometry, leading to the identification of one mutant, termed EC5, that showed improved endothelial tropism when inserted into all three capsid serotypes. Intra-ocular and intravenous administration of EC5 mutants in C57Bl/6j mice demonstrated moderately improved transduction of the retinal vasculature, particularly surrounding the optic nerve head, and evidence of sinusoidal endothelial cell transduction in the liver. Most notably, intravenous administration of the rAAV2/2[QuadYF-TV] EC5 mutant led to a dramatic and unexpected increase in cardiac muscle transduction.
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Affiliation(s)
- Ramesh Periasamy
- Department of Ophthalmology and Visual Science, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Dwani D. Patel
- Department of Ophthalmology and Visual Science, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Cell Biology, Neurobiology, Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Sanford L. Boye
- Department of Pediatrics, Powell Gene Therapy Center, University of Florida, Gainesville, FL, United States of America
| | - Shannon E. Boye
- Department of Pediatrics, Division of Cellular and Molecular Biology, University of Florida, Gainesville, FL, United States of America
| | - Daniel M. Lipinski
- Department of Ophthalmology and Visual Science, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Cell Biology, Neurobiology, Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
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3
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Böldicke T. Therapeutic Potential of Intrabodies for Cancer Immunotherapy: Current Status and Future Directions. Antibodies (Basel) 2022; 11:antib11030049. [PMID: 35892709 PMCID: PMC9326752 DOI: 10.3390/antib11030049] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 06/29/2022] [Accepted: 07/12/2022] [Indexed: 12/04/2022] Open
Abstract
Tumor cells are characterized by overexpressed tumor-associated antigens or mutated neoantigens, which are expressed on the cell surface or intracellularly. One strategy of cancer immunotherapy is to target cell-surface-expressed tumor-associated antigens (TAAs) with therapeutic antibodies. For targeting TAAs or neoantigens, adoptive T-cell therapies with activated autologous T cells from cancer patients transduced with novel recombinant TCRs or chimeric antigen receptors have been successfully applied. Many TAAs and most neoantigens are expressed in the cytoplasm or nucleus of tumor cells. As alternative to adoptive T-cell therapy, the mRNA of intracellular tumor antigens can be depleted by RNAi, the corresponding genes or proteins deleted by CRISPR-Cas or inactivated by kinase inhibitors or by intrabodies, respectively. Intrabodies are suitable to knockdown TAAs and neoantigens without off-target effects. RNA sequencing and proteome analysis of single tumor cells combined with computational methods is bringing forward the identification of new neoantigens for the selection of anti-cancer intrabodies, which can be easily performed using phage display antibody repertoires. For specifically delivering intrabodies into tumor cells, the usage of new capsid-modified adeno-associated viruses and lipid nanoparticles coupled with specific ligands to cell surface receptors can be used and might bring cancer intrabodies into the clinic.
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Affiliation(s)
- Thomas Böldicke
- Department Structure and Function of Proteins, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
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4
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Flitsch LJ, Börner K, Stüllein C, Ziegler S, Sonntag-Buck V, Wiedtke E, Semkova V, Au Yeung SWC, Schlee J, Hajo M, Mathews M, Ludwig BS, Kossatz S, Kessler H, Grimm D, Brüstle O. Identification of adeno-associated virus variants for gene transfer into human neural cell types by parallel capsid screening. Sci Rep 2022; 12:8356. [PMID: 35589936 PMCID: PMC9120183 DOI: 10.1038/s41598-022-12404-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 05/09/2022] [Indexed: 12/11/2022] Open
Abstract
Human brain cells generated by in vitro cell programming provide exciting prospects for disease modeling, drug discovery and cell therapy. These applications frequently require efficient and clinically compliant tools for genetic modification of the cells. Recombinant adeno-associated viruses (AAVs) fulfill these prerequisites for a number of reasons, including the availability of a myriad of AAV capsid variants with distinct cell type specificity (also called tropism). Here, we harnessed a customizable parallel screening approach to assess a panel of natural or synthetic AAV capsid variants for their efficacy in lineage-related human neural cell types. We identified common lead candidates suited for the transduction of directly converted, early-stage induced neural stem cells (iNSCs), induced pluripotent stem cell (iPSC)-derived later-stage, radial glia-like neural progenitors, as well as differentiated astrocytic and mixed neuroglial cultures. We then selected a subset of these candidates for functional validation in iNSCs and iPSC-derived astrocytes, using shRNA-induced downregulation of the citrate transporter SLC25A1 and overexpression of the transcription factor NGN2 for proofs-of-concept. Our study provides a comparative overview of the susceptibility of different human cell programming-derived brain cell types to AAV transduction and a critical discussion of the assets and limitations of this specific AAV capsid screening approach.
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Affiliation(s)
- Lea Jessica Flitsch
- Institute of Reconstructive Neurobiology, University of Bonn Medical Faculty and University Hospital Bonn, Venusberg-Campus 1, Building 76, 53127, Bonn, Germany
| | - Kathleen Börner
- Center for Infectious Diseases, Virology, Medical Faculty, Heidelberg University, Im Neuenheimer Feld 344, 69120, Heidelberg, Germany.,BioQuant, Heidelberg University, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany.,German Center for Infection Research (DZIF), partner site Heidelberg, 69120, Heidelberg, Germany.,AskBio GmbH, Am Taubenfeld 21, 69123, Heidelberg, Germany
| | - Christian Stüllein
- CLADIAC GmbH, Kurfürsten-Anlage 52-58, 69115, Heidelberg, Germany.,Stüllein Software Engineering (SSE), Friedrich-Hartung-Str. 16, 64560, Riedstadt, Germany
| | - Simon Ziegler
- CLADIAC GmbH, Kurfürsten-Anlage 52-58, 69115, Heidelberg, Germany.,KINSYS GmbH, Holtzstr. 2, 76135, Karlsruhe, Germany
| | - Vera Sonntag-Buck
- Center for Infectious Diseases, Virology, Medical Faculty, Heidelberg University, Im Neuenheimer Feld 344, 69120, Heidelberg, Germany.,BioQuant, Heidelberg University, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany.,German Center for Infection Research (DZIF), partner site Heidelberg, 69120, Heidelberg, Germany
| | - Ellen Wiedtke
- Center for Infectious Diseases, Virology, Medical Faculty, Heidelberg University, Im Neuenheimer Feld 344, 69120, Heidelberg, Germany.,BioQuant, Heidelberg University, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany
| | - Vesselina Semkova
- Institute of Reconstructive Neurobiology, University of Bonn Medical Faculty and University Hospital Bonn, Venusberg-Campus 1, Building 76, 53127, Bonn, Germany.,LIFE and BRAIN GmbH, Venusberg-Campus 1, Building 76, 53127, Bonn, Germany
| | - Si Wah Christina Au Yeung
- Institute of Reconstructive Neurobiology, University of Bonn Medical Faculty and University Hospital Bonn, Venusberg-Campus 1, Building 76, 53127, Bonn, Germany
| | - Julia Schlee
- Institute of Reconstructive Neurobiology, University of Bonn Medical Faculty and University Hospital Bonn, Venusberg-Campus 1, Building 76, 53127, Bonn, Germany
| | - Mohamad Hajo
- Institute of Reconstructive Neurobiology, University of Bonn Medical Faculty and University Hospital Bonn, Venusberg-Campus 1, Building 76, 53127, Bonn, Germany.,Federal Institute for Drugs and Medical Devices (BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175, Bonn, Germany
| | - Mona Mathews
- LIFE and BRAIN GmbH, Venusberg-Campus 1, Building 76, 53127, Bonn, Germany
| | - Beatrice Stefanie Ludwig
- Department of Nuclear Medicine, School of Medicine, Technical University Munich (TUM), University Hospital Klinikum Rechts der Isar and Central Institute for Translational Cancer Research (Transla TUM, Einsteinstr. 25, 81675, Munich, Germany
| | - Susanne Kossatz
- Department of Nuclear Medicine, School of Medicine, Technical University Munich (TUM), University Hospital Klinikum Rechts der Isar and Central Institute for Translational Cancer Research (Transla TUM, Einsteinstr. 25, 81675, Munich, Germany
| | - Horst Kessler
- Institute for Advanced Study, Department Chemie, Technical University Munich (TUM), Lichtenbergstr. 4, 85747, Garching, Germany
| | - Dirk Grimm
- Center for Infectious Diseases, Virology, Medical Faculty, Heidelberg University, Im Neuenheimer Feld 344, 69120, Heidelberg, Germany. .,BioQuant, Heidelberg University, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany. .,German Center for Infection Research (DZIF), partner site Heidelberg, 69120, Heidelberg, Germany. .,German Center for Cardiovascular Research (DZHK), partner site Heidelberg, 69120, Heidelberg, Germany.
| | - Oliver Brüstle
- Institute of Reconstructive Neurobiology, University of Bonn Medical Faculty and University Hospital Bonn, Venusberg-Campus 1, Building 76, 53127, Bonn, Germany. .,LIFE and BRAIN GmbH, Venusberg-Campus 1, Building 76, 53127, Bonn, Germany.
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5
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Belova L, Kochergin‐Nikitsky K, Erofeeva A, Lavrov A, Smirnikhina S. Approaches to purification and concentration of rAAV vectors for gene therapy. Bioessays 2022; 44:e2200019. [DOI: 10.1002/bies.202200019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 03/14/2022] [Accepted: 03/15/2022] [Indexed: 11/11/2022]
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Hacker UT, Bentler M, Kaniowska D, Morgan M, Büning H. Towards Clinical Implementation of Adeno-Associated Virus (AAV) Vectors for Cancer Gene Therapy: Current Status and Future Perspectives. Cancers (Basel) 2020; 12:E1889. [PMID: 32674264 PMCID: PMC7409174 DOI: 10.3390/cancers12071889] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 07/03/2020] [Accepted: 07/07/2020] [Indexed: 02/06/2023] Open
Abstract
Adeno-associated virus (AAV) vectors have gained tremendous attention as in vivo delivery systems in gene therapy for inherited monogenetic diseases. First market approvals, excellent safety data, availability of large-scale production protocols, and the possibility to tailor the vector towards optimized and cell-type specific gene transfer offers to move from (ultra) rare to common diseases. Cancer, a major health burden for which novel therapeutic options are urgently needed, represents such a target. We here provide an up-to-date overview of the strategies which are currently developed for the use of AAV vectors in cancer gene therapy and discuss the perspectives for the future translation of these pre-clinical approaches into the clinic.
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Affiliation(s)
- Ulrich T. Hacker
- Department of Oncology, Gastroenterology, Hepatology, Pulmonology, and Infectious Diseases, University Cancer Center Leipzig (UCCL), Leipzig University Medical Center, 04103 Leipzig, Germany;
- Institute of Experimental Hematology, Hannover Medical School, 30625 Hannover, Germany; (M.B.); (M.M.)
| | - Martin Bentler
- Institute of Experimental Hematology, Hannover Medical School, 30625 Hannover, Germany; (M.B.); (M.M.)
| | - Dorota Kaniowska
- Department of Oncology, Gastroenterology, Hepatology, Pulmonology, and Infectious Diseases, University Cancer Center Leipzig (UCCL), Leipzig University Medical Center, 04103 Leipzig, Germany;
| | - Michael Morgan
- Institute of Experimental Hematology, Hannover Medical School, 30625 Hannover, Germany; (M.B.); (M.M.)
- REBIRTH Research Center for Translational Regenerative Medicine, Hannover Medical School, 30625 Hannover, Germany
| | - Hildegard Büning
- Institute of Experimental Hematology, Hannover Medical School, 30625 Hannover, Germany; (M.B.); (M.M.)
- REBIRTH Research Center for Translational Regenerative Medicine, Hannover Medical School, 30625 Hannover, Germany
- German Center for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Inhoffenstraße 7, 38124 Braunschweig, Germany
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7
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Pre-arrayed Pan-AAV Peptide Display Libraries for Rapid Single-Round Screening. Mol Ther 2020; 28:1016-1032. [PMID: 32105604 DOI: 10.1016/j.ymthe.2020.02.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 10/07/2019] [Accepted: 02/08/2020] [Indexed: 12/27/2022] Open
Abstract
Display of short peptides on the surface of adeno-associated viruses (AAVs) is a powerful technology for the generation of gene therapy vectors with altered cell specificities and/or transduction efficiencies. Following its extensive prior use in the best characterized AAV serotype 2 (AAV2), recent reports also indicate the potential of other AAV isolates as scaffolds for peptide display. In this study, we systematically explored the respective capacities of 13 different AAV capsid variants to tolerate 27 peptides inserted on the surface followed by production of reporter-encoding vectors. Single-round screening in pre-arrayed 96-well plates permitted rapid and simple identification of superior vectors in >90 cell types, including T cells and primary cells. Notably, vector performance depended not only on the combination of capsid, peptide, and cell type, but also on the position of the inserted peptide and the nature of flanking residues. For optimal data availability and accessibility, all results were assembled in a searchable online database offering multiple output styles. Finally, we established a reverse-transduction pipeline based on vector pre-spotting in 96- or 384-well plates that facilitates high-throughput library panning. Our comprehensive illustration of the vast potential of alternative AAV capsids for peptide display should accelerate their in vivo screening and application as unique gene therapy vectors.
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8
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Büning H, Srivastava A. Capsid Modifications for Targeting and Improving the Efficacy of AAV Vectors. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2019; 12:248-265. [PMID: 30815511 PMCID: PMC6378346 DOI: 10.1016/j.omtm.2019.01.008] [Citation(s) in RCA: 155] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In the past decade, recombinant vectors based on a non-pathogenic parvovirus, the adeno-associated virus (AAV), have taken center stage as a gene delivery vehicle for the potential gene therapy for a number of human diseases. To date, the safety of AAV vectors in 176 phase I, II, and III clinical trials and their efficacy in at least eight human diseases are now firmly documented. Despite these remarkable achievements, it has also become abundantly clear that the full potential of first generation AAV vectors composed of naturally occurring capsids is not likely to be realized, since the wild-type AAV did not evolve for the purpose of therapeutic gene delivery. In this article, we provide a brief historical account of the progress that has been made in the development of capsid-modified, next-generation AAV vectors to ensure both the safety and efficacy of these vectors in targeting a wide variety of human diseases.
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Affiliation(s)
- Hildegard Büning
- Institute of Experimental Hematology, Hannover Medical School, Hannover, Germany.,REBIRTH Cluster of Excellence, Hannover Medical School, Hannover, Germany
| | - Arun Srivastava
- Division of Cellular and Molecular Therapy, Departments of Pediatrics and Molecular Genetics & Microbiology, Powell Gene Therapy Center, University of Florida College of Medicine, Gainesville, FL, USA
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9
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Dhungel B, Jayachandran A, Layton CJ, Steel JC. Seek and destroy: targeted adeno-associated viruses for gene delivery to hepatocellular carcinoma. Drug Deliv 2017; 24:289-299. [PMID: 28165834 PMCID: PMC8241004 DOI: 10.1080/10717544.2016.1247926] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Hepatocellular carcinoma (HCC) is the most common form of primary liver cancer with high incidence globally. Increasing mortality and morbidity rates combined with limited treatment options available for advanced HCC press for novel and effective treatment modalities. Gene therapy represents one of the most promising therapeutic options. With the recent approval of herpes simplex virus for advanced melanoma, the field of gene therapy has received a major boost. Adeno-associated virus (AAV) is among the most widely used and effective viral vectors today with safety and efficacy demonstrated in a number of human clinical trials. This review identifies the obstacles for effective AAV based gene delivery to HCC which primarily include host immune responses and off-target effects. These drawbacks could be more pronounced for HCC because of the underlying liver dysfunction in most of the patients. We discuss approaches that could be adopted to tackle these shortcomings and manufacture HCC-targeted vectors. The combination of transductional targeting by modifying the vector capsid and transcriptional targeting using HCC-specific promoters has the potential to produce vectors which can specifically seek HCC and deliver therapeutic gene without significant side effects. Finally, the identification of novel HCC-specific ligands and promoters should facilitate and expedite this process.
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Affiliation(s)
- Bijay Dhungel
- a Gallipoli Medical Research Institute, Greenslopes Private Hospital , Brisbane , QLD , Australia.,b School of Medicine, The University of Queensland , Brisbane , QLD , Australia.,c University of Queensland Diamantina Institute, Translational Research Institute , Woolloongabba , QLD , Australia , and
| | - Aparna Jayachandran
- a Gallipoli Medical Research Institute, Greenslopes Private Hospital , Brisbane , QLD , Australia.,b School of Medicine, The University of Queensland , Brisbane , QLD , Australia
| | - Christopher J Layton
- b School of Medicine, The University of Queensland , Brisbane , QLD , Australia.,d Ophthalmology Department, Gallipoli Medical Research Institute, Greenslopes Private Hospital , Brisbane , QLD , Australia
| | - Jason C Steel
- a Gallipoli Medical Research Institute, Greenslopes Private Hospital , Brisbane , QLD , Australia.,b School of Medicine, The University of Queensland , Brisbane , QLD , Australia
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Lisowski L, Tay SS, Alexander IE. Adeno-associated virus serotypes for gene therapeutics. Curr Opin Pharmacol 2015; 24:59-67. [PMID: 26291407 DOI: 10.1016/j.coph.2015.07.006] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 07/27/2015] [Accepted: 07/29/2015] [Indexed: 12/11/2022]
Abstract
Gene transfer vectors based on adeno-associated virus (AAV) are showing exciting therapeutic promise in early phase clinical trials. The ability to cross-package the prototypic AAV2 vector genome into different capsids is a powerful way of conferring novel tropism and biology, with evolving capsid engineering technologies and directed evolution approaches further enhancing the utility and flexibility of these vectors. Novel properties of specific capsids show unpredictable species and cell-type specificity. Therefore, full realisation of the therapeutic potential of AAV vectors requires the development of more therapeutically predictive preclinical methods for evaluating capsid performance. This will strongly complement an iterative approach to the evaluation of capsid variants in the clinic and, should wherever possible, include the determination of gene transfer efficiencies.
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Affiliation(s)
- Leszek Lisowski
- Gene Transfer, Targeting and Therapeutics Core, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, San Diego, CA, USA
| | - Szun Szun Tay
- Gene Therapy Research Unit, The Children's Hospital at Westmead and Children's Medical Research Institute, Locked Bag 4001, Westmead 2145, NSW, Australia
| | - Ian Edward Alexander
- Gene Therapy Research Unit, The Children's Hospital at Westmead and Children's Medical Research Institute, Locked Bag 4001, Westmead 2145, NSW, Australia; Discipline of Paediatrics and Child Health, The University of Sydney, NSW, Australia.
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11
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Davis AS, Federici T, Ray WC, Boulis NM, OʼConnor D, Clark KR, Bartlett JS. Rational design and engineering of a modified adeno-associated virus (AAV1)-based vector system for enhanced retrograde gene delivery. Neurosurgery 2015; 76:216-25; discussion 225. [PMID: 25549186 DOI: 10.1227/neu.0000000000000589] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND After injection into muscle and peripheral nerves, a variety of viral vectors undergo retrograde transport to lower motor neurons. However, because of its attractive safety profile and durable gene expression, adeno-associated virus (AAV) remains the only vector to have been applied to the human nervous system for the treatment of neurodegenerative disease. Nonetheless, only a very small fraction of intramuscularly injected AAV vector arrives at the spinal cord. OBJECTIVE To engineer a novel AAV vector by inserting a neuronal targeting peptide (Tet1), with binding properties similar to those of tetanus toxin, into the AAV1 capsid. METHODS Integral to this approach was the use of structure-based design to increase the effectiveness of functional capsid engineering. This approach allowed the optimization of scaffolding regions for effective display of the foreign epitope while minimizing disruption of the native capsid structure. We also validated an approach by which low-titer tropism-modified AAV vectors can be rescued by particle mosaicism with unmodified capsid proteins. RESULTS Importantly, our rationally engineered AAV1-based vectors exhibited markedly enhanced transduction of cultured motor neurons, diminished transduction of nontarget cells, and markedly superior retrograde delivery compared with unmodified AAV1 vector. CONCLUSION This approach promises a significant advancement in the rational engineering of AAV vectors for diseases of the nervous system and other organs.
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Affiliation(s)
- Adam S Davis
- ‡Gene Therapy Center and ¶Battelle Center for Mathematical Medicine, The Research Institute at Nationwide Children's Hospital, Nationwide Children's Hospital, Columbus, Ohio; §Department of Neurosurgery, Emory University, Atlanta, Georgia; ‖Department of Pediatrics, College of Medicine and Public Health and #Department of Molecular Virology, Immunology, and Medical Genetics, College of Medicine and Public Health, The Ohio State University Columbus, Ohio; **Calimmune, Inc, Tucson, Arizona
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12
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Abstract
INTRODUCTION An estimated 25 million Americans are living with rare diseases. Adeno-associated virus (AAV)-mediated gene therapy is an emerging therapeutic option for the more than 7,000 identified rare diseases. This paper highlights the benefits of AAV therapy compared to conventional small molecules, discusses current pre-clinical and clinical applications of AAV-mediated gene therapy, and offers insights into cutting edge research that will shape the future of AAV for broad therapeutic use. AREAS COVERED In this review the biology of AAV and our ability to generate disease-specific variants is summarized. Limitations of current therapy are reviewed, with an emphasis on immune detection of virus, viral tropism and tissue targeting, and limitations of gene expression. Information for this review was found using PubMed and clinicaltrials.gov. EXPERT OPINION Currently the scope of clinical trials of AAV gene therapy is concentrated in an array of phase I/II safety trials with less than two dozen rare diseases featured. Pre-clinical, translational studies are expanding in number as developments within the last decade have made generation of improved AAV vectors available to more researchers. Further, one bottleneck that is being overcome is the availability of disease models, which will allow for improved preclinical testing and advancement of AAV to more clinical applications.
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Affiliation(s)
- Eric Hastie
- Gene Therapy Center, University of North Carolina, Chapel Hill, North Carolina, USA, The University of North Carolina at Chapel Hill, 7119 Thurston Bowles Building (104 Manning Drive), Campus Box 7352, Chapel Hill, NC, 27599-7352, United States
| | - R Jude Samulski
- Gene Therapy Center, University of North Carolina, Chapel Hill, North Carolina, USA, The University of North Carolina at Chapel Hill, 7119 Thurston Bowles Building (104 Manning Drive), Campus Box 7352, Chapel Hill, NC, 27599-7352, United States; Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina, USA, The University of North Carolina at Chapel Hill, 7119 Thurston Bowles Building (104 Manning Drive), Campus Box 7352, Chapel Hill, NC, 27599-7352, United States
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13
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Qu W, Wang M, Wu Y, Xu R. Scalable downstream strategies for purification of recombinant adeno- associated virus vectors in light of the properties. Curr Pharm Biotechnol 2015; 16:684-95. [PMID: 25941887 PMCID: PMC5388796 DOI: 10.2174/1389201016666150505122228] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 12/30/2014] [Accepted: 04/06/2015] [Indexed: 12/27/2022]
Abstract
Recombinant adeno-associated virus (rAAV) vector is one of the promising delivery tools for gene therapy. Currently, hundreds of clinical trials are performed but the major barrier for clinical application is the absence of any ideal large scale production technique to obtain sufficient and highly pure rAAV vector. The large scale production technique includes upstream and downstream processing. The upstream processing is a vector package step and the downstream processing is a vector purification step. For large scale downstream processing, the scientists need to recover rAAV from dozens of liters of cell lysate or medium, and a variety of purification strategies have been developed but not comprehensively compared till now. Consequently, this review will evaluate the scalable downstream purification strategies systematically, especially those based on the physicochemical properties of AAV virus, and attempt to find better scalable downstream strategies for rAAV vectors.
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Affiliation(s)
| | - Mingxi Wang
- Yunleung Laboratory of Molecular Diagnostics, School of Medicine and Institute of Molecular Medicine, Huaqiao University, Quanzhou 362021, China.
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14
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Sagare AP, Deane R, Zlokovic BV. Low-density lipoprotein receptor-related protein 1: a physiological Aβ homeostatic mechanism with multiple therapeutic opportunities. Pharmacol Ther 2012; 136:94-105. [PMID: 22820095 PMCID: PMC3432694 DOI: 10.1016/j.pharmthera.2012.07.008] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Accepted: 07/03/2012] [Indexed: 11/29/2022]
Abstract
Low-density lipoprotein receptor-related protein-1 (LRP1) is the main cell surface receptor involved in brain and systemic clearance of the Alzheimer's disease (AD) toxin amyloid-beta (Aβ). In plasma, a soluble form of LRP1 (sLRP1) is the major transport protein for peripheral Aβ. LRP1 in brain endothelium and mural cells mediates Aβ efflux from brain by providing a transport mechanism for Aβ across the blood-brain barrier (BBB). sLRP1 maintains a plasma 'sink' activity for Aβ through binding of peripheral Aβ which in turn inhibits re-entry of free plasma Aβ into the brain. LRP1 in the liver mediates systemic clearance of Aβ. In AD, LRP1 expression at the BBB is reduced and Aβ binding to circulating sLRP1 is compromised by oxidation. Cell surface LRP1 and circulating sLRP1 represent druggable targets which can be therapeutically modified to restore the physiological mechanisms of brain Aβ homeostasis. In this review, we discuss how increasing LRP1 expression at the BBB and liver with lifestyle changes, statins, plant-based active principles and/or gene therapy on one hand, and how replacing dysfunctional plasma sLRP1 on the other regulate Aβ clearance from brain ultimately controlling the onset and/or progression of AD.
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Affiliation(s)
- Abhay P. Sagare
- Department of Physiology and Biophysics, and Center for Neurodegeneration and Regeneration at the Zilkha Neurogenetic Institute, University of Southern California, Keck School of Medicine, 1501 San Pablo Street, Los Angeles, CA 90089, United States
| | - Rashid Deane
- Department of Neurosurgery, Arthur Kornberg Medical Research Building, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, United States
| | - Berislav V. Zlokovic
- Department of Physiology and Biophysics, and Center for Neurodegeneration and Regeneration at the Zilkha Neurogenetic Institute, University of Southern California, Keck School of Medicine, 1501 San Pablo Street, Los Angeles, CA 90089, United States
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15
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Robertson KE, McDonald RA, Oldroyd KG, Nicklin SA, Baker AH. Prevention of coronary in-stent restenosis and vein graft failure: does vascular gene therapy have a role? Pharmacol Ther 2012; 136:23-34. [PMID: 22796519 DOI: 10.1016/j.pharmthera.2012.07.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 06/28/2012] [Indexed: 12/19/2022]
Abstract
Coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI), including stent insertion, are established therapies in both acute coronary syndromes (ACS) and symptomatic chronic coronary artery disease refractory to pharmacological therapy. These continually advancing treatments remain limited by failure of conduit grafts in CABG and by restenosis or thrombosis of stented vessel segments in PCI caused by neointimal hyperplasia, impaired endothelialisation and accelerated atherosclerosis. While pharmacological and technological advancements have improved patient outcomes following both procedures, when grafts or stents fail these result in significant health burdens. In this review we discuss the pathophysiology of vein graft disease and in-stent restenosis, gene therapy vector development and design, and translation from pre-clinical animal models through human clinical trials. We identify the key issues that are currently preventing vascular gene therapy from interfacing with clinical use and introduce the areas of research attempting to overcome these.
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Affiliation(s)
- Keith E Robertson
- British Heart Foundation Glasgow Cardiovascular Research Centre, Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
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16
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Abstract
The use of recombinant adeno-associated virus (rAAV) vectors in gene therapy for preclinical studies in animal models and human clinical trials is increasing, as these vectors have been shown to be safe and to mediate persistent transgene expression in vivo. Constant improvement in rAAV manufacturing processes (upstream production and downstream purification) has paralleled this evolution to meet the needs for larger vector batches, higher vector titer, and improved vector quality and safety. This chapter provides an overview of existing production and purification systems used for adeno-associated virus (AAV) vectors, and the advantages and disadvantages of each system are outlined. Regulatory guidelines that apply to the use of these systems for clinical trials are also presented. The methods described are examples of protocols that have been utilized for establishing rAAV packaging cell lines, production of rAAV vectors using recombinant HSV infection, and for chromatographic purification of various AAV vector serotypes. A protocol for the production of clinical-grade rAAV type 2 vectors using transient transfection and centrifugation-based purification is also described.
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17
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Lee HS, Kim JY, Lee WI, Kim SJ, Ko MJ, Jeong S, Park K, Choe H, Lee H. Acquisition of selective antitumoral effects of recombinant adeno-associated virus by genetically inserting tumor-targeting peptides into capsid proteins. Oncol Lett 2011; 2:1113-1119. [PMID: 22848276 DOI: 10.3892/ol.2011.376] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Accepted: 07/25/2011] [Indexed: 11/05/2022] Open
Abstract
Recombinant adeno-associated virus serotype 5 (rAAV5) is considered to be a promising gene transfer vehicle. However, preferential gene delivery to the tumor remains a requirement for cancer treatment. We generated rAAV5 mutants bearing tumor marker-binding peptides and analyzed their properties as viral vectors, as well as their transduction efficiencies and preferential antitumoral potencies. All of the mutants were successfully produced. Transduction analyses showed that rAAV5 mutants harboring tumor-homing peptides, including RGD and TnC, transduced human cancer cells expressing corresponding receptors on their surfaces. RGDS peptides and TnC antibodies significantly suppressed transduction by rAAV5-RGD and rAAV5-TnC. Cytotoxicity was evident upon transfer of HSV-TK to cells by re-targeted rAAV5. These results provide evidence that rAAV5 vectors, genetically armed with tumor-targeting ligands, preferentially infect human cancer cells harboring the corresponding receptors, thereby inducing antitumoral effects. Further optimization of rAAV5 mutant viruses should thus facilitate practical exploitation of these vectors for gene-based cancer treatment.
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Affiliation(s)
- Han Saem Lee
- Department of Microbiology, University of Ulsan College of Medicine, Seoul
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18
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Abstract
Viral vector is the most effective means of gene transfer to modify specific cell type or tissue and can be manipulated to express therapeutic genes. Several virus types are currently being investigated for use to deliver genes to cells to provide either transient or permanent transgene expression. These include adenoviruses (Ads), retroviruses (γ-retroviruses and lentiviruses), poxviruses, adeno-associated viruses, baculoviruses, and herpes simplex viruses. The choice of virus for routine clinical use will depend on the efficiency of transgene expression, ease of production, safety, toxicity, and stability. This chapter provides an introductory overview of the general characteristics of viral vectors commonly used in gene transfer and their advantages and disadvantages for gene therapy use.
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Affiliation(s)
- James N Warnock
- School of Chemical & Bioprocess Engineering and Conway Institute for Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin, Ireland
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Segura MM, Kamen AA, Garnier A. Overview of current scalable methods for purification of viral vectors. Methods Mol Biol 2011; 737:89-116. [PMID: 21590394 DOI: 10.1007/978-1-61779-095-9_4] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
As a result of the growing interest in the use of viruses for gene therapy and vaccines, many virus-based products are being developed. The manufacturing of viruses poses new challenges for process developers and regulating authorities that need to be addressed to ensure quality, efficacy, and safety of the final product. The design of suitable purification strategies will depend on a multitude of variables including the vector production system and the nature of the virus. In this chapter, we provide an overview of the most commonly used purification methods for viral gene therapy vectors. Current chromatography options available for large-scale purification of γ-retrovirus, lentivirus, adenovirus, adeno-associated virus, herpes simplex virus, baculovirus, and poxvirus vectors are presented.
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Affiliation(s)
- María Mercedes Segura
- Department of Biochemistry and Molecular Biology, Center of Animal Biotechnology and Gene Therapy (CBATEG), Universitat Autònoma de Barcelona, Barcelona, Spain.
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20
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Mitchell AM, Nicolson SC, Warischalk JK, Samulski RJ. AAV's anatomy: roadmap for optimizing vectors for translational success. Curr Gene Ther 2010; 10:319-340. [PMID: 20712583 PMCID: PMC3920455 DOI: 10.2174/156652310793180706] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2010] [Accepted: 07/20/2010] [Indexed: 12/14/2022]
Abstract
Adeno-Associated Virus based vectors (rAAV) are advantageous for human gene therapy due to low inflammatory responses, lack of toxicity, natural persistence, and ability to transencapsidate the genome allowing large variations in vector biology and tropism. Over sixty clinical trials have been conducted using rAAV serotype 2 for gene delivery with a number demonstrating success in immunoprivileged sites, including the retina and the CNS. Furthermore, an increasing number of trials have been initiated utilizing other serotypes of AAV to exploit vector tropism, trafficking, and expression efficiency. While these trials have demonstrated success in safety with emerging success in clinical outcomes, one benefit has been identification of issues associated with vector administration in humans (e.g. the role of pre-existing antibody responses, loss of transgene expression in non-immunoprivileged sites, and low transgene expression levels). For these reasons, several strategies are being used to optimize rAAV vectors, ranging from addition of exogenous agents for immune evasion to optimization of the transgene cassette for enhanced therapeutic output. By far, the vast majority of approaches have focused on genetic manipulation of the viral capsid. These methods include rational mutagenesis, engineering of targeting peptides, generation of chimeric particles, library and directed evolution approaches, as well as immune evasion modifications. Overall, these modifications have created a new repertoire of AAV vectors with improved targeting, transgene expression, and immune evasion. Continued work in these areas should synergize strategies to improve capsids and transgene cassettes that will eventually lead to optimized vectors ideally suited for translational success.
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Affiliation(s)
- Angela M. Mitchell
- UNC Gene Therapy Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Sarah C. Nicolson
- UNC Gene Therapy Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Jayme K. Warischalk
- UNC Gene Therapy Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - R. Jude Samulski
- UNC Gene Therapy Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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Lesch HP, Kaikkonen MU, Pikkarainen JT, Ylä-Herttuala S. Avidin-biotin technology in targeted therapy. Expert Opin Drug Deliv 2010; 7:551-64. [PMID: 20233034 DOI: 10.1517/17425241003677749] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
IMPORTANCE OF THE FIELD The goal of drug targeting is to increase the concentration of the drug in the vicinity of the cells responsible for disease without affecting healthy cells. Many approaches in cancer treatment are limited because of their broad range of unwanted side effects on healthy cells. Targeting can reduce side effects and increase efficacy of drugs in the patient. AREAS COVERED IN THIS REVIEW Avidin, originally isolated from chicken eggs, and its bacterial analogue, streptavidin, from Streptomyces avidinii, have extremely high affinity for biotin. This unique feature is the basis of avidin-biotin technology. This article reviews the current status of avidin-biotin systems and their use for pretargeted drug delivery and vector targeting. WHAT THE READER WILL GAIN The reader will gain an understanding of the following approaches using the avidin-biotin system: i) targeting antibodies and therapeutic molecules are administered separately leading to a reduction of drug dose in normal tissues compared with conventional (radio)immunotherapies; ii) introducing avidin gene into specific tissues by local gene transfer, which subsequently can sequester and concentrate considerable amounts of therapeutic ligands; and iii) enabling transductional targeting of gene therapy vectors. TAKE HOME MESSAGE Avidin and biotin technology has proved to be an extremely versatile tool with broad applications, such as pretargeting, delivering avidin gene into cells enabling targeting of biotinylated compounds and targeting of viral vectors.
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Affiliation(s)
- Hanna P Lesch
- University of Eastern Finland, A.I. Virtanen institute, Department of Biotechnology and Molecular Medicine, Kuopio, Finland
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22
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Zhang X, Zhuang J, Wu H, Chen Z, Su J, Chen S, Chen J. Inhibitory effects of calcitonin gene-related peptides on experimental vein graft disease. Ann Thorac Surg 2010; 90:117-23. [PMID: 20609760 DOI: 10.1016/j.athoracsur.2010.03.063] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2010] [Revised: 03/17/2010] [Accepted: 03/22/2010] [Indexed: 11/25/2022]
Abstract
BACKGROUND Vein graft disease is a chronic inflammatory disease and limits the long-term clinical outcome of coronary revascularization. Because calcitonin gene-related peptide (CGRP) inhibits macrophage infiltration and inflammatory mediators, we hypothesized that transfected CGRP gene would inhibit macrophage infiltration and expression of inflammatory mediators in vein graft disease. METHODS Autologous rabbit jugular vein grafts were incubated ex vivo in a solution of mosaic adeno-associated virus vectors containing CGRP gene (AAV2/1.CGRP) or Escherichia coli B-galactosidase gene (LacZ) or a saline solution and then interposed in the carotid artery. Expression of CGRP gene was identified by reverse transcription-polymerase chain reaction, and E. coli LacZ gene expression was identified by X-gal staining. Intima to media ratios were evaluated at postoperative 4 weeks. Macrophages were identified with CD68 antibody by immunocytochemistry. Inflammatory mediators were measured with real-time polymerase chain reaction. RESULTS The CGRP and LacZ gene expression were positive at postoperative 4 weeks. The intima to media ratio was significantly inhibited in the AAV2/1.CGRP group. Macrophage infiltration and expression of inflammatory mediators including monocyte chemoattractant protein-1, tumor necrosis factor-alpha, inducible nitric oxide synthase, and matrix metalloproteinase-9 were also significantly inhibited in the AAV2/1.CGRP group. CONCLUSIONS Transfection of AAV2/1.CGRP inhibited inflammatory mediator expression, macrophage infiltration, and neointimal hyperplasia in experimental vein graft disease.
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Affiliation(s)
- Xiaoning Zhang
- Guangdong Academy of Medical Sciences, Guangdong General Hospital, Guangdong Provincial Cardiovascular Disease Research Institute, Guangzhou, China
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23
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Michelfelder S, Trepel M. Adeno-associated viral vectors and their redirection to cell-type specific receptors. ADVANCES IN GENETICS 2010; 67:29-60. [PMID: 19914449 DOI: 10.1016/s0065-2660(09)67002-4] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Efficient and specific delivery of genes to the cell type of interest is a crucial issue in gene therapy. Adeno-associated virus (AAV) has gained particular interest as gene vector recently and is therefore the focus of this chapter. Its low frequency of random integration into the genome and the moderate immune response make AAV an attractive platform for vector design. Like in most other vector systems, the tropism of AAV vectors limits their utility for certain tissues especially upon systemic application. This may in part be circumvented by using AAV serotypes with an in vivo gene transduction pattern most closely fitting the needs of the application. Also, the tropism of AAV capsids may be changed by combining parts of the natural serotype diversity. In addition, peptides mediating binding to the cell type of interest can be identified by random phage display library screening and subsequently be introduced into an AAV capsid region critical for receptor binding. Such peptide insertions can abrogate the natural tropism of AAV capsids and result in detargeting from the liver in vivo. In a novel approach, cell type-directed vector capsids can be selected from random peptide libraries displayed on viral capsids or serotype-shuffling libraries in vitro and in vivo for optimized transduction of the cell type or tissue of interest.
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Affiliation(s)
- Stefan Michelfelder
- Department of Oncology and Hematology, Hubertus Wald Cancer Center, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Martin Trepel
- Department of Oncology and Hematology, Hubertus Wald Cancer Center, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
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24
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Parrish CR. Structures and functions of parvovirus capsids and the process of cell infection. Curr Top Microbiol Immunol 2010; 343:149-76. [PMID: 20397069 DOI: 10.1007/82_2010_33] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
To infect a cell, the parvovirus or adeno-associated virus (AAV) genome must be delivered from outside the plasma membrane to the nucleus, and in the process, the capsid must follow a series of binding and trafficking steps and also undergo necessary changes that result in exposure or release the ssDNA genome at the appropriate time and place within the cell. The 25 nm parvovirus capsid is comprised of two or three forms of a single protein, and although it is robust and stable, it is still sufficiently flexible to allow the exposure of several internal components at appropriate times during cell infection. The capsid can also accommodate insertion of peptides into surface loops, and capsid proteins from different viral serotypes can be shuffled to create novel functional variants. The capsids of the different viruses bind to one or more cell receptors, and for at least some viruses, the insertion of additional or alternative receptor binding sequences or structures into the capsid can expand or redirect its tropism. The infection process after cell binding involves receptor-mediated endocytosis followed by viral trafficking through the endosomal systems. That endosomal trafficking may be complex and prolonged for hours or be relatively brief. Generally only a small proportion of the particles taken up enter the cytoplasm after altering the endosomal membrane through the activity of a VP1-encoded phospholipase A2 domain that becomes released to the outside of the viral particle. Modifications to the capsid that can occur within the endosome or cytoplasm include structural changes to expose internal components, ubiquination and proteosomal processing, and possible trafficking of particles on molecular motors. It is still not clear how the genomes enter the nucleus, but nuclear pore-dependent entry of particles or permeabilization of nuclear membranes have been proposed. Those processes control the infection, pathogenesis, and host ranges of the autonomous viruses and determine the effectiveness of gene therapy using AAV capsids.
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Affiliation(s)
- Colin R Parrish
- Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA.
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Howarth JL, Lee YB, Uney JB. Using viral vectors as gene transfer tools (Cell Biology and Toxicology Special Issue: ETCS-UK 1 day meeting on genetic manipulation of cells). Cell Biol Toxicol 2009; 26:1-20. [PMID: 19830583 PMCID: PMC2817806 DOI: 10.1007/s10565-009-9139-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2009] [Accepted: 09/24/2009] [Indexed: 02/06/2023]
Abstract
In recent years, the development of powerful viral gene transfer techniques has greatly facilitated the study of gene function. This review summarises some of the viral delivery systems routinely used to mediate gene transfer into cell lines, primary cell cultures and in whole animal models. The systems described were originally discussed at a 1-day European Tissue Culture Society (ETCS-UK) workshop that was held at University College London on 1st April 2009. Recombinant-deficient viral vectors (viruses that are no longer able to replicate) are used to transduce dividing and post-mitotic cells, and they have been optimised to mediate regulatable, powerful, long-term and cell-specific expression. Hence, viral systems have become very widely used, especially in the field of neurobiology. This review introduces the main categories of viral vectors, focusing on their initial development and highlighting modifications and improvements made since their introduction. In particular, the use of specific promoters to restrict expression, translational enhancers and regulatory elements to boost expression from a single virion and the development of regulatable systems is described.
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(Strept)avidin-displaying lentiviruses as versatile tools for targeting and dual imaging of gene delivery. Gene Ther 2009; 16:894-904. [PMID: 19440224 DOI: 10.1038/gt.2009.47] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Lentiviruses have shown great promise for human gene therapy. However, no optimal strategies are yet available for noninvasive imaging of virus biodistribution and subsequent transduction in vivo. We have developed a dual-imaging strategy based on avidin-biotin system allowing easy exchange of the surface ligand on HIV-derived lentivirus envelope. This was achieved by displaying avidin or streptavidin fused to the transmembrane anchor of vesicular stomatitis virus G protein on gp64-pseudotyped envelopes. Avidin and streptavidin were efficiently incorporated on virus particles, which consequently showed binding to biotin in ELISA. These vectors, conjugated to biotinylated radionuclides and engineered to express a ferritin transgene, enabled for the first-time dual imaging of virus biodistribution and transduction pattern by single-photon emission computed tomography and magnetic resonance imaging after stereotactic injection into rat brain. In addition, vector retargeting to cancer cells overexpressing CD46, epidermal growth factor and transferrin receptors using biotinylated ligands and antibodies was demonstrated in vitro. In conclusion, we have generated novel lentivirus vectors for noninvasive imaging and targeting of lentivirus-mediated gene delivery. This study suggests that these novel vectors could be applicable for the treatment of central nervous system disorders and cancer.
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Ong HT, Trejo TR, Pham LD, Oberg AL, Russell SJ, Peng KW. Intravascularly administered RGD-displaying measles viruses bind to and infect neovessel endothelial cells in vivo. Mol Ther 2009; 17:1012-21. [PMID: 19277014 DOI: 10.1038/mt.2009.39] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Systemically administered vectors must cross the endothelial lining of tumor blood vessels to access cancer cells. Vectors that interact with markers on the lumenal surface of these endothelial cells might have enhanced tumor localization. Here, we generated oncolytic measles viruses (MVs) displaying alpha(v)beta(3) integrin-binding peptides, cyclic arginine-glycine-aspartate (RGD) or echistatin, on the measles hemagglutinin protein. Both viruses had expanded tropisms, and efficiently entered target cells via binding to integrins, but also retained their native tropisms for CD46 and signaling lymphocyte activation molecule (SLAM). When fluorescently labeled and injected intravascularly into chick chorioallantoic membranes (CAMs), in contrast to unmodified viruses, the integrin-binding viral particles bound to the lumenal surface of the developing chick neovessels and infected the CAM vascular endothelial cells. In a mouse model of VEGF-induced angiogenesis in the ear pinna, the integrin-binding viruses, but not the parental virus, infected cells at sites of new blood vessel formation. When given intravenously to mice bearing tumor xenografts, the integrin-binding virus infected endothelial cells of tumor neovessels in addition to tumor parenchyma. To our knowledge, this is the first report demonstrating that oncolytic MVs can be engineered to target the lumenal endothelial surface of newly formed blood vessels when administered intravenously in living animals.
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Affiliation(s)
- Hooi Tin Ong
- Department of Molecular Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA
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Shi WF, Bartlett JS. Estrogen plays a critical role in AAV2-mediated gene transfer in ovarian cancer. Acta Pharmacol Sin 2008; 29:1440-50. [PMID: 19026163 DOI: 10.1111/j.1745-7254.2008.00894.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
AIM The aim of our study was to develop an effective gene delivery system for ovarian cancer gene therapy. METHODS The expression of heparin sulfate proteoglycan (HSPG) and integrins alpha(upsilon)beta(3) and alpha(upsilon)beta(5) were analyzed with flow cytometry on 2 human ovarian cancer cell lines (OVCAR-3 and SKOV-3ip). The gene transduction efficiencies were evaluated with recombinant adeno-associated viral vector (rAAV)2-green fluorescent protein or rAAV2-lactase Z followed by flow cytometry or cytohistochemistry staining. The effect of 17beta-estradiol on ovarian cancer cell proliferation, HSPG, the expressions of integrins alpha(upsilon)beta(3) and alpha(upsilon)beta(5), and adeno-associated viral vector (AAV)2-mediated gene transduction were determined. RESULTS In the present study, we found: (1) a variation in HSPG and the expressions of integrins alpha(upsilon)beta(3) and alpha(upsilon)beta(5) between OVCAR-3 and SKOV-3ip; (2) that 17beta-estradiol was shown to significantly stimulate cell proliferation and integrin beta(5) expression in certain ovarian cancer cell lines; and (3) integrintargeted A520/N584RGD-rAAV2, which has alternative interactivity with integrins and abrogates the binding capacity HSPG, showed much higher gene transduction efficiency in ovarian cancer cells than rAAV2 in the presence/absence of 17beta-estradiol. Moreover, this RGD-modified rAAV2 exerted more efficient transduction in ovarian cancer cells in response to 17beta-estradiol. CONCLUSION Our findings implied that A520/N584RGD-rAAV2 may offer great potential for ovarian cancer treatment in vivo.
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Affiliation(s)
- Wen-fang Shi
- Laboratory of Gene and Viral Therapy, Eastern Hepatobiliary Surgical Hospital, Second Military Medical University, Shanghai 200433, China.
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Abstract
SUMMARY The unique life cycle of adeno-associated virus (AAV) and its ability to infect both nondividing and dividing cells with persistent expression have made it an attractive vector. An additional attractive feature of the wild-type virus is the lack of apparent pathogenicity. Gene transfer studies using AAV have shown significant progress at the level of animal models; clinical trials have been noteworthy with respect to the safety of AAV vectors. No proven efficacy has been observed, although in some instances, there have been promising observations. In this review, topics in AAV biology are supplemented with a section on AAV clinical trials with emphasis on the need for a deeper understanding of AAV biology and the development of efficient AAV vectors. In addition, several novel approaches and recent findings that promise to expand AAV's utility are discussed, especially in the context of combining gene therapy ex vivo with new advances in stem or progenitor cell biology.
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LPS-induced MCP-1 expression in human microvascular endothelial cells is mediated by the tyrosine kinase, Pyk2 via the p38 MAPK/NF-kappaB-dependent pathway. Mol Immunol 2008; 46:962-8. [PMID: 18954908 DOI: 10.1016/j.molimm.2008.09.022] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2008] [Revised: 09/12/2008] [Accepted: 09/15/2008] [Indexed: 11/22/2022]
Abstract
Bacterial endotoxin (lipopolysaccharide or LPS) has potent pro-inflammatory properties and acts on many cell types including endothelial cells. Secretion of the CC chemokine, MCP-1 (CCL2) by LPS-activated endothelial cells contributes substantially to the pathogenesis of sepsis. However, the mechanism involved in LPS-induced MCP-1 production in endothelial cells is not well understood. Using human microvascular endothelial cells (HMVEC), we analyzed the involvement of the non-receptor tyrosine kinase, Pyk2, in LPS-mediated MCP-1 production. There was a marked activation of the non-receptor tyrosine kinase, Pyk2, in response to LPS. Inhibition of Pyk2 activity using a pharmacological inhibitor, Tyrphostin A9 significantly attenuated LPS-induced Pyk2 tyrosine phosphorylation, p38 MAP kinase (MAPK) activation, NF-kappaB activation, and MCP-1 expression. Furthermore, specific inactivation of Pyk2 activity by transducing microvascular endothelial cells with catalytically inactive Pyk2 mutant (AAV-Pyk2MT) or Pyk2-specific siRNA significantly blocked LPS-induced MCP-1 production. The supernatants of these LPS-stimulated cells with attenuated Pyk2 activity demonstrated decreased trans-endothelial monocyte migration in comparison to LPS-treated controls, thus confirming the inhibition of functional MCP-1 production. In summary, our data suggest a critical role for the Pyk2 mediated pathway involving p38 MAP kinase and NF-kappaB in LPS-induced MCP-1 production in human microvascular endothelial cells.
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Abstract
Viruses can be engineered to efficiently deliver exogenous genes, but their natural gene delivery properties often fail to meet human therapeutic needs. Therefore, engineering viral vectors with new properties, including enhanced targeting abilities and resistance to immune responses, is a growing area of research. This review discusses protein engineering approaches to generate viral vectors with novel gene delivery capabilities. Rational design of viral vectors has yielded successful advances in vitro, and to an extent in vivo. However, there is often insufficient knowledge of viral structure-function relationships to reengineer existing functions or create new capabilities, such as virus-cell interactions, whose molecular basis is distributed throughout the primary sequence of the viral proteins. Therefore, high-throughput library and directed evolution methods offer alternative approaches to engineer viral vectors with desired properties. Parallel and integrated efforts in rational and library-based design promise to aid the translation of engineered viral vectors toward the clinic.
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Affiliation(s)
- David V Schaffer
- The Department of Chemical Engineering, the Department of Bioengineering, and The Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720-3220, USA.
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32
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Büning H, Perabo L, Coutelle O, Quadt-Humme S, Hallek M. Recent developments in adeno-associated virus vector technology. J Gene Med 2008; 10:717-33. [PMID: 18452237 DOI: 10.1002/jgm.1205] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Adeno-associated virus (AAV), a single-stranded DNA parvovirus, is emerging as one of the leading gene therapy vectors owing to its nonpathogenicity and low immunogenicity, stability and the potential to integrate site-specifically without known side-effects. A portfolio of recombinant AAV vector types has been developed with the aim of optimizing efficiency, specificity and thereby also the safety of in vitro and in vivo gene transfer. More and more information is now becoming available about the mechanism of AAV/host cell interaction improving the efficacy of recombinant AAV vector (rAAV) mediated gene delivery. This review summarizes the current knowledge of the infectious biology of AAV, provides an overview of the latest developments in the field of AAV vector technology and discusses remaining challenges.
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Affiliation(s)
- Hildegard Büning
- Clinic I for Internal Medicine, University of Cologne, Cologne, Germany.
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33
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Kaikkonen MU, Viholainen JI, Närvänen A, Ylä-Herttuala S, Airenne KJ. Targeting and purification of metabolically biotinylated baculovirus. Hum Gene Ther 2008; 19:589-600. [PMID: 18479188 DOI: 10.1089/hum.2007.177] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Targeting viral entry is one of the major goals in the development of vectors for gene therapy. Ideally, the coupling of each new targeting motif would not require changes in vector structure. To achieve this, we developed novel metabolically biotinylated baculoviral vectors by displaying a small biotin acceptor peptide (BAP) fused either to different sites in the baculovirus glycoprotein gp64 or to the transmembrane anchor of vesicular stomatitis virus G protein. Baculoviral particles were biotinylated during vector production by coexpression of Escherichia coli biotin ligase (BirA). The insertion of BAP at amino acid position 283 of gp64 resulted in the most efficient biotin display. Unlike vectors with lower biotin display, these vectors also showed improved transduction when retargeted to transferrin, epidermal growth factor, and CD46 receptors overexpressed on rat glioma and human ovarian carcinoma cells. Biotinylated baculoviral vectors could also be concentrated by one-step magnetic particle-based capture to reach titers up to 10(10) plaque-forming units/ml. These results demonstrate the utility of metabolically biotinylated baculovirus for vector targeting and viral purification applications.
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Affiliation(s)
- Minna U Kaikkonen
- Department of Biotechnology and Molecular Medicine, A.I. Virtanen Institute for Molecular Sciences, FIN-70211 Kuopio, Finland
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34
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Stachler MD, Chen I, Ting AY, Bartlett JS. Site-specific modification of AAV vector particles with biophysical probes and targeting ligands using biotin ligase. Mol Ther 2008; 16:1467-73. [PMID: 18560418 DOI: 10.1038/mt.2008.129] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
We have developed a highly specific and robust new method for labeling adeno-associated virus (AAV) vector particles with either biophysical probes or targeting ligands. Our approach uses the Escherichia coli enzyme biotin ligase (BirA), which ligates biotin to a 15-amino-acid biotin acceptor peptide (BAP) in a sequence-specific manner. In this study we demonstrate that by using a ketone isotere of biotin as a cofactor we can ligate this probe to BAP-modified AAV capsids. Because ketones are absent from AAV, BAP-modified AAV particles can be tagged with the ketone probe and then specifically conjugated to hydrazide- or hydroxylamine-functionalized molecules. We demonstrate this two-stage modification methodology in the context of a mammalian cell lysate for the labeling of AAV vector particles with various fluorophores, and for the attachment of a synthetic cyclic arginine-glycine-aspartate (RGD) peptide (c(RGDfC)) to target integrin receptors that are present on neovasculature. Fluorophore labeling allowed the straightforward determination of intracellular particle distribution. Ligand conjugation mediated a significant increase in the transduction of endothelial cells in vitro, and permitted the intravascular targeting of AAV vectors to tumor-associated vasculature in vivo. These results suggest that this approach holds significant promise for future studies aimed at understanding and modifying AAV vector-cellular interactions.
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Affiliation(s)
- Matthew D Stachler
- Gene Therapy Center, The Research Institute at Nationwide Children's Hospital, Nationwide Children's Hospital, Columbus, Ohio, USA
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35
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Schultz BR, Chamberlain JS. Recombinant adeno-associated virus transduction and integration. Mol Ther 2008; 16:1189-99. [PMID: 18500252 DOI: 10.1038/mt.2008.103] [Citation(s) in RCA: 143] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Recombinant adeno-associated virus (rAAV) holds promise as a gene therapy vector for a multitude of genetic disorders such as hemophilia, cystic fibrosis, and the muscular dystrophies. Given the variety of applications and tissue types toward which these vectors may be targeted, an understanding of rAAV transduction is crucial for the effective application of therapy. rAAV transduction mechanisms have been the subject of much study, resulting in a body of knowledge relating to events from virus-cell attachment through to vector genome conformation in the target cell nucleus. Instead of utilizing one mechanism in each phase of vector transduction, rAAV appears to employ multiple possible pathways toward transgene expression, in part dependent on rAAV serotype, dose, and target cell type. Once inside the nucleus, the rAAV genome exists in a predominantly episomal form; therefore, nondividing cells tend to be most stably transduced. However, rAAV has a low frequency of integration into the host cell genome, often in or near genes, and can be associated with host genome mutations. This review describes the current understanding of the mechanisms and rate-limiting steps involved in rAAV transduction.
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Affiliation(s)
- Brian R Schultz
- Molecular and Cellular Biology, Senator Paul D Wellstone Muscular Dystrophy Cooperative Research Center, University of Washington, Seattle, Washington, USA
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36
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Van Vliet KM, Blouin V, Brument N, Agbandje-McKenna M, Snyder RO. The role of the adeno-associated virus capsid in gene transfer. Methods Mol Biol 2008; 437:51-91. [PMID: 18369962 PMCID: PMC7120696 DOI: 10.1007/978-1-59745-210-6_2] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Adeno-associated virus (AAV) is one of the most promising viral gene transfer vectors that has been shown to effect long-term gene expression and disease correction with low toxicity in animal models, and is well tolerated in human clinical trials. The surface of the AAV capsid is an essential component that is involved in cell binding, internalization, and trafficking within the targeted cell. Prior to developing a gene therapy strategy that utilizes AAV, the serotype should be carefully considered since each capsid exhibits a unique tissue tropism and transduction efficiency. Several approaches have been undertaken in an effort to target AAV vectors to specific cell types, including utilizing natural serotypes that target a desired cellular receptor, producing pseudotyped vectors, and engineering chimeric and mosaic AAV capsids. These capsid modifications are being incorporated into vector production and purification methods that provide for the ability to scale-up the manufacturing process to support human clinical trials. Protocols for small-scale and large-scale production of AAV, as well as assays to characterize the final vector product, are presented here. The structures of AAV2, AAV4, and AAV5 have been solved by X-ray crystallography or cryo-electron microscopy (cryo-EM), and provide a basis for rational vector design in developing customized capsids for specific targeting of AAV vectors. The capsid of AAV has been shown to be remarkably stable, which is a desirable characteristic for a gene therapy vector; however, recently it has been shown that the AAV serotypes exhibit differential susceptibility to proteases. The capsid fragmentation pattern when exposed to various proteases, as well as the susceptibility of the serotypes to a series of proteases, provides a unique fingerprint for each serotype that can be used for capsid identity validation. In addition to serotype identification, protease susceptibility can also be utilized to study dynamic structural changes that must occur for the AAV capsid to perform its various functions during the virus life cycle. The use of proteases for structural studies in solution complements the crystal structural studies of the virus. A generic protocol based on proteolysis for AAV serotype identification is provided here.
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Affiliation(s)
- Kim M Van Vliet
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, USA
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37
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Kwon I, Schaffer DV. Designer gene delivery vectors: molecular engineering and evolution of adeno-associated viral vectors for enhanced gene transfer. Pharm Res 2007; 25:489-99. [PMID: 17763830 PMCID: PMC2265771 DOI: 10.1007/s11095-007-9431-0] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2007] [Accepted: 08/03/2007] [Indexed: 12/23/2022]
Abstract
Gene delivery vectors based on adeno-associated virus (AAV) are highly promising due to several desirable features of this parent virus, including a lack of pathogenicity, efficient infection of dividing and non-dividing cells, and sustained maintenance of the viral genome. However, several problems should be addressed to enhance the utility of AAV vectors, particularly those based on AAV2, the best characterized AAV serotype. First, altering viral tropism would be advantageous for broadening its utility in various tissue or cell types. In response to this need, vector pseudotyping, mosaic capsids, and targeting ligand insertion into the capsid have shown promise for altering AAV specificity. In addition, library selection and directed evolution have recently emerged as promising approaches to modulate AAV tropism despite limited knowledge of viral structure-function relationships. Second, pre-existing immunity to AAV must be addressed for successful clinical application of AAV vectors. "Shielding" polymers, site-directed mutagenesis, and alternative AAV serotypes have shown success in avoiding immune neutralization. Furthermore, directed evolution of the AAV capsid is a high throughput approach that has yielded vectors with substantial resistance to neutralizing antibodies. Molecular engineering and directed evolution of AAV vectors therefore offer promise for generating 'designer' gene delivery vectors with enhanced properties.
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Affiliation(s)
- Inchan Kwon
- Department of Chemical Engineering and Helen Wills Neuroscience Institute, University of California, 201 Gilman Hall, Berkeley, California 94720-1462 USA
| | - David V. Schaffer
- Department of Chemical Engineering and Helen Wills Neuroscience Institute, University of California, 201 Gilman Hall, Berkeley, California 94720-1462 USA
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38
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Abstract
Translating knowledge of genetic disease mechanisms into gene therapies has been slow with limited clinical success. One major reason is that the transfer vectors, which are most often of viral origin, are not targeted sufficiently towards the cells of interest. To achieve successful delivery of genetic material, transductional targeting is often essential to enter the target cell and to avoid side effects from the transduction of non-target cells. Many techniques to target viral vectors to specific cells have been developed. They can be divided into three types: systems that use adaptor proteins from other viruses (pseudotyping); systems that use adaptors to couple the targeting ligand to the vector; and systems that genetically incorporate the targeting moiety into the viral genome. Whereas systems involving adaptor proteins are highly useful in preclinical evaluations, systems that make use of genetically incorporated targeting ligands are advantageous for clinical applications. Combinations of several targeting principles (including ablation of natural tropism, pseudotyping and adaptors) and novel combinations (such as the adeno-associated virus (AAV) genome in a phage vector) allow systemic vector application. An initial clinical study with a targeted retrovirus showed feasibility to transfer laboratory success to patient application, underlining that there are no principal regulatory barriers for targeted vectors. Systemic vector applications will be facilitated by enabling the vector to move beyond the vascular endothelium at specific sites, using transcytosis or cellular vehicles. The application of existing targeting techniques to new viral vector serotypes and new vector classes is extending the therapeutic capabilities further. Obstacles to systemic application of vectors are found in the blood as immune reactions against the vector and as binding of blood proteins to the vector. Some targeting approaches might have the potential to circumvent these obstacles. To preclinically evaluate new targeting strategies, several models that reflect the human situation to varying degrees are available. The use of primary cells, tissue-slice systems and transgenic animals seems to be especially promising. Imaging technologies provide the ability to monitor the vector in vivo in real time without sacrificing the animal model. These techniques facilitate vector targeting and biodistribution studies.
A key challenge in gene therapy is vector targeting to specific cells, while avoiding effects on other tissues. Several strategies have been developed recently to enable targeting of the main viral vectors, moving them a step closer to clinical use. To achieve therapeutic success, transfer vehicles for gene therapy must be capable of transducing target cells while avoiding impact on non-target cells. Despite the high transduction efficiency of viral vectors, their tropism frequently does not match the therapeutic need. In the past, this lack of appropriate targeting allowed only partial exploitation of the great potential of gene therapy. Substantial progress in modifying viral vectors using diverse techniques now allows targeting to many cell types in vitro. Although important challenges remain for in vivo applications, the first clinical trials with targeted vectors have already begun to take place.
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Affiliation(s)
- Reinhard Waehler
- Division of Human Gene Therapy, 502 Biomedical Research Building II, 901 19th Street, South Birmingham, 35294-2172 Alabama USA
| | - Stephen J. Russell
- Molecular Medicine Program, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, 55905 Minnesota USA
| | - David T. Curiel
- Division of Human Gene Therapy, 502 Biomedical Research Building II, 901 19th Street, South Birmingham, 35294-2172 Alabama USA
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39
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White K, Nicklin SA, Baker AH. Novel vectors forin vivogene delivery to vascular tissue. Expert Opin Biol Ther 2007; 7:809-21. [PMID: 17555367 DOI: 10.1517/14712598.7.6.809] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Although some success has been achieved with gene delivery in animal models of vascular disorders, the results from some clinical trials have been less promising, possibly due, in part, to the use of suboptimal vectors for in vivo gene transfer. Non-viral vectors have a very low transfection efficiency so are largely unsuitable for most in vivo applications, and the relatively broad tropism of many of the commonly used viral vectors can limit efficient gene delivery specifically to target vascular tissues. However, characterisation of novel virus serotypes and advances in techniques that enable vectors to be targeted to the required tissue have led to progress in the development of novel vectors that could be utilised for gene delivery for vascular disorders.
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Affiliation(s)
- Kathryn White
- University of Glasgow, British Heart Foundation Glasgow Cardiovascular Research Centre, Glasgow, UK
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40
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Balestrieri ML, Napoli C. Novel challenges in exploring peptide ligands and corresponding tissue-specific endothelial receptors. Eur J Cancer 2007; 43:1242-50. [PMID: 17449238 DOI: 10.1016/j.ejca.2007.02.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2006] [Revised: 02/06/2007] [Accepted: 02/08/2007] [Indexed: 12/14/2022]
Abstract
The structural and molecular diversity of vascular endothelium may depend on the functional state and tissue localisation of its cells. Tumour vasculature expresses a number of molecular markers that distinguish it from normal vasculature. In cancer, the determinant of specific tumour vasculature heterogeneity is, in part, dictated by dysregulated expression of tumour-derived angiogenic factors. The identification of molecular 'addresses' on the surface of tumour vasculature has significantly contributed to the selection of targets, which have been used for delivering therapeutic and imaging agents in cancer. Cytotoxic drug, pro-apoptotic peptides, protease inhibitors, and gene therapy vectors have been successfully linked to peptides and delivered to tumour sites with an improved experimental therapy. Different diagnostic and therapeutic compounds can be efficiently targeted to specific receptors on vascular endothelial cells; the development of ligand-directed vector tools may promote systemic targeted gene delivery. Here, we review the very recent advances in the identification of peptide ligands and their corresponding tissue-specific endothelial receptors through the phage display technology with emphasis on ligand-directed delivery of therapeutic agents and targeted gene therapy.
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Affiliation(s)
- Maria Luisa Balestrieri
- Department of Chemical Biology and Physics; 1st School of Medicine, II University of Naples, Complesso S. Andrea delle Dame, Naples 80138, Italy
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41
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Abstract
Cardiovascular diseases are the major cause of morbidity and mortality in both men and women in industrially developed countries. These disorders may result from impaired angiogenesis, particularly in response to hypoxia. Despite many limitations, gene therapy is still emerging as a potential alternative for patients who are not candidates for traditional revascularization procedures, like angioplasty or vein grafts. This review focuses on recent approaches in the development of new gene delivery vectors, with great respect to newly discovered AAV serotypes and their modified forms. Moreover, some new cardiovascular gene therapy strategies have been highlighted, such as combination of different angiogenic growth factors or simultaneous application of genes and progenitor cells in order to obtain stable and functional blood vessels in ischemic tissue.
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Affiliation(s)
| | | | - J. Dulak
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Krakow, Poland; Tel: +48-12-664-63-75; Fax: +48-12-664-69-18; E-mail:
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