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Weber JA, Lang JF, Carrell EM, Alameh MG, Davidson BL. Temporal restriction of Cas9 expression improves CRISPR-mediated deletion efficacy and fidelity. MOLECULAR THERAPY. NUCLEIC ACIDS 2024; 35:102172. [PMID: 38978694 PMCID: PMC11229411 DOI: 10.1016/j.omtn.2024.102172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 03/08/2024] [Indexed: 07/10/2024]
Abstract
Clinical application of CRISPR-Cas9 technology for large deletions of somatic mutations is inefficient, and methods to improve utility suffer from our inability to rapidly assess mono- vs. biallelic deletions. Here we establish a model system for investigating allelic heterogeneity at the single-cell level and identify indel scarring from non-simultaneous nuclease activity at gRNA cut sites as a major barrier to CRISPR-del efficacy both in vitro and in vivo. We show that non-simultaneous nuclease activity is partially prevented via restriction of CRISPR-Cas9 expression via inducible adeno-associated viruses (AAVs) or lipid nanoparticles (LNPs). Inducible AAV-based expression of CRISPR-del machinery significantly improved mono- and biallelic deletion frequency in vivo, supporting the use of the Xon cassette over traditional constitutively expressing AAV approaches. These data depicting improvements to deletions and insight into allelic heterogeneity after CRISPR-del will inform therapeutic approaches for phenotypes that require either large mono- or biallelic deletions, such as autosomal recessive diseases or where mutant allele-specific gRNAs are not readily available, or in situations where the targeted sequence for excision is located multiple times in a genome.
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Affiliation(s)
- Jesse A Weber
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Cell and Molecular Biology Graduate Group, Biomedical Graduate Studies, University of Pennsylvania, Philadelphia, PA, USA
| | - Jonathan F Lang
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Cell and Molecular Biology Graduate Group, Biomedical Graduate Studies, University of Pennsylvania, Philadelphia, PA, USA
| | - Ellie M Carrell
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Mohamad-Gabriel Alameh
- Penn Institute for RNA Innovation, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Beverly L Davidson
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
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2
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Presa M, Bailey RM, Davis C, Murphy T, Cook J, Walls R, Wilpan H, Bogdanik L, Lenk GM, Burgess RW, Gray SJ, Lutz C. AAV9-mediated FIG4 delivery prolongs life span in Charcot-Marie-Tooth disease type 4J mouse model. J Clin Invest 2021; 131:137159. [PMID: 33878035 PMCID: PMC8159684 DOI: 10.1172/jci137159] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 04/15/2021] [Indexed: 12/23/2022] Open
Abstract
Charcot-Marie-Tooth disease type 4J (CMT4J) is caused by recessive, loss-of-function mutations in FIG4, encoding a phosphoinositol(3,5)P2-phosphatase. CMT4J patients have both neuron loss and demyelination in the peripheral nervous system, with vacuolization indicative of endosome/lysosome trafficking defects. Although the disease is highly variable, the onset is often in childhood and FIG4 mutations can dramatically shorten life span. There is currently no treatment for CMT4J. Here, we present the results of preclinical studies testing a gene-therapy approach to restoring FIG4 expression. A mouse model of CMT4J, the Fig4-pale tremor (plt) allele, was dosed with a single-stranded adeno-associated virus serotype 9 (AAV9) to deliver a codon-optimized human FIG4 sequence. Untreated, Fig4plt/plt mice have a median survival of approximately 5 weeks. When treated with the AAV9-FIG4 vector at P1 or P4, mice survived at least 1 year, with largely normal gross motor performance and little sign of neuropathy by neurophysiological or histopathological evaluation. When mice were treated at P7 or P11, life span was still significantly prolonged and peripheral nerve function was improved, but rescue was less complete. No unanticipated adverse effects were observed. Therefore, AAV9-mediated delivery of FIG4 is a well-tolerated and efficacious strategy in a mouse model of CMT4J.
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Affiliation(s)
| | - Rachel M. Bailey
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | | | - Tara Murphy
- The Jackson Laboratory, Bar Harbor, Maine, USA
| | - Jenn Cook
- The Jackson Laboratory, Bar Harbor, Maine, USA
| | - Randy Walls
- The Jackson Laboratory, Bar Harbor, Maine, USA
| | | | | | - Guy M. Lenk
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, USA
| | | | - Steven J. Gray
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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3
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Scimia MC, Cannavo A, Koch WJ. Gene therapy for heart disease: molecular targets, vectors and modes of delivery to myocardium. Expert Rev Cardiovasc Ther 2014; 11:999-1013. [PMID: 23984926 DOI: 10.1586/14779072.2013.818813] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Despite the numerous hurdles that gene therapy has encountered along the way, clinical trials over the last few years are showing promising results in many fields of medicine, including cardiology, where many targets are moving toward clinical development. In this review, the authors discuss the current state of the art in terms of clinical and preclinical development. They also examine vector technology and available vector-delivery strategies.
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Affiliation(s)
- Maria Cecilia Scimia
- Department of Pharmacology, Center for Translational Medicine, Temple University School of Medicine, 3500 N Broad St, MERB 941, Philadelphia, PA 19140, USA
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4
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Bockstael O, Melas C, Pythoud C, Levivier M, McCarty D, Samulski RJ, De Witte O, Tenenbaum L. Rapid transgene expression in multiple precursor cell types of adult rat subventricular zone mediated by adeno-associated type 1 vectors. Hum Gene Ther 2012; 23:742-53. [PMID: 22471423 DOI: 10.1089/hum.2011.216] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The adult rat brain subventricular zone (SVZ) contains proliferative precursors that migrate to the olfactory bulb (OB) and differentiate into mature neurons. Recruitment of precursors constitutes a potential avenue for brain repair. We have investigated the kinetics and cellular specificity of transgene expression mediated by AAV2/1 vectors (i.e., adeno-associated virus type 2 pseudotyped with AAV1 capsid) in the SVZ. Self-complementary (sc) and single-stranded (ss) AAV2/1 vectors mediated efficient GFP expression, respectively, at 17 and 24 hr postinjection. Transgene expression was efficient in all the rapidly proliferating cells types, that is, Mash1(+) precursors (30% of the GFP(+) cells), Dlx2(+) neuronal progenitors (55%), Olig2(+) oligodendrocyte progenitors (35%), and doublecortin-positive (Dcx(+)) migrating cells (40%), but not in the slowly proliferating glial fibrillary acidic protein-positive (GFAP(+)) neural stem cell pool (5%). Because cell cycle arrest by wild-type and recombinant AAV has been described in primary cultures, we examined SVZ proliferative activity after vector injection. Indeed, cell proliferation was reduced immediately after vector injection but was normal after 1 month. In contrast, migration and differentiation of GFP(+) precursors were unaltered. Indeed, the proportion of Dcx(+) cells was similar in the injected and contralateral hemispheres. Furthermore, 1 month after vector injection into the SVZ, GFP(+) cells, found, as expected, in the OB granular cell layer, were mature GABAergic neurons. In conclusion, the rapid and efficient transgene expression in SVZ neural precursors mediated by scAAV2/1 vectors underlines their potential usefulness for brain repair via recruitment of immature cells. The observed transient precursor proliferation inhibition, not affecting their migration and differentiation, will likely not compromise this strategy.
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Affiliation(s)
- Olivier Bockstael
- Laboratory of Experimental Neurosurgery, Université Libre de Bruxelles, BE-1070 Brussels, Belgium.
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5
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Chaanine AH, Kalman J, Hajjar RJ. Cardiac gene therapy. Semin Thorac Cardiovasc Surg 2011; 22:127-39. [PMID: 21092890 DOI: 10.1053/j.semtcvs.2010.09.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/03/2010] [Indexed: 11/11/2022]
Abstract
Heart failure is a chronic progressive disorder in which frequent and recurrent hospitalizations are associated with high mortality and morbidity. The incidence and the prevalence of this disease will increase with the increase in the number of the aging population of the United States. Understanding the molecular pathology and pathophysiology of this disease will uncover novel targets and therapies that can restore the function or attenuate the damage of malfunctioning cardiomyocytes by gene therapy that becomes an interesting and a promising field for the treatment of heart failure as well as other diseases in the future. Of equal importance are developing vectors and delivery methods that can efficiently transduce most of the cardiomyocytes that can offer a long-term expression and that can escape the host immune response. Recombinant adeno-associated virus vectors have the potential to become a promising novel therapeutic vehicles for molecular medicine in the future.
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Affiliation(s)
- Antoine H Chaanine
- Cardiovascular Institute, Mount Sinai School of Medicine, New York, New York 10029, USA
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6
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Gwathmey JK, Yerevanian AI, Hajjar RJ. Cardiac gene therapy with SERCA2a: from bench to bedside. J Mol Cell Cardiol 2010; 50:803-12. [PMID: 21093451 DOI: 10.1016/j.yjmcc.2010.11.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2010] [Revised: 10/27/2010] [Accepted: 11/10/2010] [Indexed: 10/18/2022]
Abstract
While progress in conventional treatments is making steady and incremental gains to reduce mortality associated with heart failure, there remains a need to explore potentially new therapeutic approaches. Heart failure induced by different etiologies such as coronary artery disease, hypertension, diabetes, infection, or inflammation results generally in calcium cycling dysregulation at the myocyte level. Recent advances in understanding of the molecular basis of these calcium cycling abnormalities, together with the evolution of increasingly efficient gene transfer technology, have placed heart failure within reach of gene-based therapy. Furthermore, the recent successful completion of a phase 2 trial targeting the sarcoplasmic reticulum calcium pump (SERCA2a) ushers in a new era for gene therapy for the treatment of heart failure. This article is part of a Special Section entitled "Special Section: Cardiovascular Gene Therapy".
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7
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Beeri R, Chaput M, Guerrero JL, Kawase Y, Yosefy C, Abedat S, Karakikes I, Morel C, Tisosky A, Sullivan S, Handschumacher MD, Gilon D, Vlahakes GJ, Hajjar RJ, Levine RA. Gene delivery of sarcoplasmic reticulum calcium ATPase inhibits ventricular remodeling in ischemic mitral regurgitation. Circ Heart Fail 2010; 3:627-34. [PMID: 20634484 DOI: 10.1161/circheartfailure.109.891184] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Mitral regurgitation (MR) doubles mortality after myocardial infarction (MI). We have demonstrated that MR worsens remodeling after MI and that early correction reverses remodeling. Sarcoplasmic reticulum Ca(+2)-ATPase (SERCA2a) is downregulated in this process. We hypothesized that upregulating SERCA2a might inhibit remodeling in a surgical model of apical MI (no intrinsic MR) with independent MR-type flow. METHODS AND RESULTS In 12 sheep, percutaneous gene delivery was performed by using a validated protocol to perfuse both the left anterior descending and circumflex coronary arteries with occlusion of venous drainage. We administered adeno-associated virus 6 (AAV6) carrying SERCA2a under a Cytomegalovirus promoter control in 6 sheep and a reporter gene in 6 controls. After 2 weeks, a standardized apical MI was created, and a shunt was implanted between the left ventricle and left atrium, producing regurgitant fractions of ≈30%. Animals were compared at baseline and 1 and 3 months by 3D echocardiography, Millar hemodynamics, and biopsies. The SERCA2a group had a well-maintained preload-recruitable stroke work at 3 months (decrease by 8±10% vs 42±12% with reporter gene controls; P<0.001). Left ventricular dP/dt followed the same pattern (no change vs 55% decrease; P<0.001). Left ventricular end-systolic volume was lower with SERCA2a (82.6±9.6 vs 99.4±9.7 mL; P=0.03); left ventricular end-diastolic volume, reflecting volume overload, was not significantly different (127.8±6.2 vs 134.3±9.4 mL). SERCA2a sheep showed a 15% rise in antiapoptotic pAkt versus a 30% reduction with the reporter gene (P<0.001). Prohypertrophic activated STAT3 was also 41% higher with SERCA2a than in controls (P<0.001). Proapoptotic activated caspase-3 rose >5-fold during 1 month in both SERCA2a and control animals (P=NS) and decreased by 19% at 3 months, remaining elevated in both groups. CONCLUSIONS In this controlled model, upregulating SERCA2a induced better function and lesser remodeling, with improved contractility, smaller volume, and activation of prohypertrophic/antiapoptotic pathways. Although caspase-3 remained activated in both groups, SERCA2a sheep had increased molecular antiremodeling "tone." We therefore conclude that upregulating SERCA2a inhibits MR-induced post-MI remodeling in this model and thus may constitute a useful approach to reduce the vicious circle of remodeling in ischemic MR.
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Affiliation(s)
- Ronen Beeri
- Cardiac Ultrasound Laboratory and Cardiac Surgery Department, Heart Center, Massachusetts General Hospital, Boston, Mass 02114, USA
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8
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Ulrich-Vinther M. Gene therapy methods in bone and joint disorders. ACTA ORTHOPAEDICA. SUPPLEMENTUM 2010. [DOI: 10.1080/17453690610046512] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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9
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Kreindler JL. Cystic fibrosis: exploiting its genetic basis in the hunt for new therapies. Pharmacol Ther 2009; 125:219-29. [PMID: 19903491 DOI: 10.1016/j.pharmthera.2009.10.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2009] [Accepted: 10/16/2009] [Indexed: 01/11/2023]
Abstract
Cystic fibrosis (CF) is caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR), an anion channel expressed in epithelial cells throughout the body. In the lungs, absence or dysfunction of CFTR results in altered epithelial salt and water transport eventuating in impaired mucociliary clearance, chronic infection and inflammation, and tissue damage. CF lung disease is the major cause of morbidity and mortality in CF despite the many therapies aimed at reducing it. However, recent technological advances combined with two decades of research driven by the discovery of the CFTR gene have resulted in the development and clinical testing of novel therapies aimed at the principal underlying defect in CF, thereby ushering in a new age of therapy for CF.
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Affiliation(s)
- James L Kreindler
- Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, 3615 Civic Center Boulevard, Abramson Research Center, Rm 1016-D, Philadelphia, PA 19104, USA.
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10
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Abstract
A hallmark of glaucomatous optic nerve damage is retinal ganglion cell (RGC) death. RGCs, like other central nervous system neurons, have a limited capacity to survive or regenerate an axon after injury. Strategies that prevent or slow down RGC degeneration, in combination with intraocular pressure management, may be beneficial to preserve vision in glaucoma. Recent progress in neurobiological research has led to a better understanding of the molecular pathways that regulate the survival of injured RGCs. Here we discuss a variety of experimental strategies including intraocular delivery of neuroprotective molecules, viral-mediated gene transfer, cell implants and stem cell therapies, which share the ultimate goal of promoting RGC survival after optic nerve damage. The challenge now is to assess how this wealth of knowledge can be translated into viable therapies for the treatment of glaucoma and other optic neuropathies.
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11
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Awad HA, Zhang X, Reynolds DG, Guldberg RE, O'Keefe RJ, Schwarz EM. Recent Advances in Gene Delivery for Structural Bone Allografts. ACTA ACUST UNITED AC 2007; 13:1973-85. [PMID: 17518728 DOI: 10.1089/ten.2006.0107] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
In this paper, we review the progress toward developing strategies to engineer improved structural grafting of bone. Three strategies are typically used to augment massive bone defect repair. The first is to engraft mesenchymal stem cells (MSCs) onto a graft or a biosynthetic matrix to provide a viable osteoinductive scaffold material for segmental defect repair. The second strategy is to introduce critical factor(s), for example, bone morphogenetic proteins (BMPs), in the form of bone-derived or recombinant proteins onto the graft or matrix directly. The third strategy uses targeted delivery of therapeutic genes (using viral and nonviral vectors) that either transduce host cells in vivo or stably transduce cells in vitro for subsequent implantation in vivo. We developed a murine femoral model in which allografts can be revitalized via recombinant adeno-associated virus (rAAV) gene transfer. Specifically, allografts coated with rAAV expressing either the constitutively active BMP type I receptor Alk2 (caAlk2), or the angiogenic factor vascular endothelial growth factor (VEGF) combined with the osteoclastogenic factor receptor activator of NF-kappa B ligand (RANKL) have remarkable osteogenic, angiogenic, and remodeling effects that have not been previously documented in healing allografts. Using histomorphometric and micro computed tomography (muCT) imaging we show that rAAV-mediated delivery of caAlk2 induces significant osteoinduction manifested by a mineralized callus on the surface of the allograft, which resembles the healing response of an autograft. We also demonstrate that the rAAV-mediated gene transfer of the combination of VEGF and RANKL can induce significant vascularization and remodeling of processed structural allografts. By contrast, rAAV-LacZ coated allograft controls appeared similar to necrotic allografts and lacked significant mineralized callus, neovascularization, and remodeling. Therefore, innovations in gene delivery offer promising therapeutic approaches for tissue engineering of structural bone substitutes that can potentially have clinical applications in challenging indications.
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Affiliation(s)
- Hani A Awad
- Department of Biomedical Engineering, The Center for Musculoskeletal Research, University of Rochester, Rochester, New York 14620, USA.
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12
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Lai CM, Yu MJT, Brankov M, Barnett NL, Zhou X, Redmond TM, Narfstrom K, Rakoczy PE. Recombinant adeno-associated virus type 2-mediated gene delivery into the Rpe65-/- knockout mouse eye results in limited rescue. GENETIC VACCINES AND THERAPY 2004; 2:3. [PMID: 15109394 PMCID: PMC416492 DOI: 10.1186/1479-0556-2-3] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2003] [Accepted: 04/27/2004] [Indexed: 11/10/2022]
Abstract
BACKGROUND Leber's congenital amaurosis (LCA) is a severe form of retinal dystrophy. Mutations in the RPE65 gene, which is abundantly expressed in retinal pigment epithelial (RPE) cells, account for approximately 10-15% of LCA cases. In this study we used the high turnover, and rapid breeding and maturation time of the Rpe65-/- knockout mice to assess the efficacy of using rAAV-mediated gene therapy to replace the disrupted RPE65 gene. The potential for rAAV-mediated gene treatment of LCA was then analyzed by determining the pattern of RPE65 expression, the physiological and histological effects that it produced, and any improvement in visual function. METHODS rAAV.RPE65 was injected into the subretinal space of Rpe65-/- knockout mice and control mice. Histological and immunohistological analyses were performed to evaluate any rescue of photoreceptors and to determine longevity and pattern of transgene expression. Electron microscopy was used to examine ultrastructural changes, and electroretinography was used to measure changes in visual function following rAAV.RPE65 injection. RESULTS rAAV-mediated RPE65 expression was detected for up to 18 months post injection. The delivery of rAAV.RPE65 to Rpe65-/- mouse retinas resulted in a transient improvement in the maximum b-wave amplitude under both scotopic and photopic conditions (76% and 59% increase above uninjected controls, respectively) but no changes were observed in a-wave amplitude. However, this increase in b-wave amplitude was not accompanied by any slow down in photoreceptor degeneration or apoptotic cell death. Delivery of rAAV.RPE65 also resulted in a decrease in retinyl ester lipid droplets and an increase in short wavelength cone opsin-positive cells, suggesting that the recovery of RPE65 expression has long-term benefits for retinal health. CONCLUSION This work demonstrated the potential benefits of using the Rpe65-/- mice to study the effects and mechanism of rAAV.RPE65-mediated gene delivery into the retina. Although the functional recovery in this model was not as robust as in the dog model, these experiments provided important clues about the long-term physiological benefits of restoration of RPE65 expression in the retina.
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Affiliation(s)
- Chooi-May Lai
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, Western Australia, 6009, Australia
| | - Meaghan JT Yu
- Department of Molecular Ophthalmology, Lions Eye Institute and The University of Western Australia, Perth, Western Australia, 6009, Australia
| | - Meliha Brankov
- Department of Molecular Ophthalmology, Lions Eye Institute and The University of Western Australia, Perth, Western Australia, 6009, Australia
| | - Nigel L Barnett
- Vision Touch and Hearing Research Centre, School of Biomedical Sciences, University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Xiaohuai Zhou
- Virus Core Facility, Gene Therapy Center, University of North Carolina, North Carolina, 27599, USA
| | - T Michael Redmond
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, 20892, USA
| | - Kristina Narfstrom
- Vision Science Group, Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri-Columbia, Columbia, Missouri, 65211, USA
| | - P Elizabeth Rakoczy
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, Western Australia, 6009, Australia
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Pachori AS, Melo LG, Zhang L, Loda M, Pratt RE, Dzau VJ. Potential for germ line transmission after intramyocardial gene delivery by adeno-associated virus. Biochem Biophys Res Commun 2004; 313:528-33. [PMID: 14697221 DOI: 10.1016/j.bbrc.2003.11.140] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Intramyocardial injection of adeno-associated virus (AAV) has been shown to be an effective strategy for cardiac gene delivery. This approach leads to long-term gene expression in the heart, offering the possibility of chronic gene therapy. However, the long-term safety of this approach with regard to vector bio-distribution and extracardiac transgene expression has not been evaluated. To examine these issues, 8-week-old male Sprague-Dawley rats were injected intramyocardially with either 4x10(11) particles of AAV-2-lacZ or saline at five locations in the anterioposterior apical region of the left ventricle. Animals were sacrificed at 3 and 6 months after gene transfer, tissues were harvested and analyzed for lacZ expression by semi-quantitative RT-PCR and beta-galactosidase activity using X-gal staining. We observed high level of transgene expression in the myocardium at 3 months after gene transfer, which persisted up to 6 months of follow-up. Also, significantly we detected lacZ expression and beta-galactosidase activity in extracardiac tissues such as liver, kidney, and testes at 6 months. More significantly, late transgene expression was detected in cellular elements of the seminiferous tubule, including Sertoli cells and spermatogonia like cells. These data demonstrate the efficacy of AAV-2 delivery for long-term myocardial gene therapy, but raise concerns about the possibility of ectopic transgene expression and germ cell line infection.
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Affiliation(s)
- Alok S Pachori
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA
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14
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Lalani AS, Chang B, Lin J, Case SS, Luan B, Wu-Prior WW, VanRoey M, Jooss K. Anti-Tumor Efficacy of Human Angiostatin Using Liver-Mediated Adeno-Associated Virus Gene Therapy. Mol Ther 2004; 9:56-66. [PMID: 14741778 DOI: 10.1016/j.ymthe.2003.10.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Angiostatin is a potent endogenous inhibitor of angiogenesis and tumor growth in vivo. The therapeutic potential of adeno-associated viral (AAV) gene delivery of angiostatin in modulating tumor growth in vivo was evaluated. Sustained levels of angiostatin were detected in the sera of mice for up to 6 months after they received a single injection of AAV-angiostatin. AAV-mediated stable expression of angiostatin inhibited tumor burden in the highly aggressive B16F10 melanoma and Lewis lung carcinoma (LLC) models of experimental metastasis. Moreover, AAV-angiostatin prolonged survival in B16F10 and LLC tumor-bearing mice compared to control groups. Anti-tumor efficacy was consistently observed when angiostatin serum levels of 15-50 ng/ml were detected following gene transfer, but the effect was minimal when the levels were lower or higher than this range. The combination of AAV-angiostatin gene therapy with chemotherapy was also shown to extend marginally the survival of mice bearing preestablished human tumors; however, the effect was evident only within a narrow dose of circulating angiostatin. These studies demonstrate the feasibility of using AAV anti-angiogenic gene therapy as a cancer treatment modality and suggest that the optimal anti-tumor efficacy of angiostatin following gene transfer may be limited to a narrow dose range.
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MESH Headings
- Angiogenesis Inhibitors/genetics
- Angiogenesis Inhibitors/metabolism
- Angiostatins/genetics
- Angiostatins/metabolism
- Animals
- Carcinoma, Lewis Lung/blood supply
- Carcinoma, Lewis Lung/pathology
- Carcinoma, Lewis Lung/therapy
- Cell Line
- Chick Embryo
- Combined Modality Therapy
- Dependovirus/genetics
- Female
- Gene Expression
- Genetic Therapy
- Genetic Vectors/administration & dosage
- Humans
- Liver/metabolism
- Melanoma, Experimental/blood supply
- Melanoma, Experimental/pathology
- Melanoma, Experimental/therapy
- Mice
- Mice, Inbred BALB C
- Mice, Nude
- Neoplasms, Experimental/blood supply
- Neoplasms, Experimental/therapy
- Neovascularization, Pathologic/etiology
- Neovascularization, Pathologic/genetics
- Neovascularization, Pathologic/therapy
- Transduction, Genetic
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Affiliation(s)
- Alshad S Lalani
- Cell Genesys, Inc., South San Francisco, California 94080, USA
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15
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Affiliation(s)
- E Lehtonen
- Free University of Brussels, Laboratory of Experimental Neurosurgery, Interdisciplinary Research Institute (IRIBHM), B-1070 Brussels, Belgium
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16
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Abstract
A key factor in the success of gene therapy is the development of gene delivery systems that are capable of efficient gene transfer in a broad variety of tissues, without causing any pathogenic effect. Currently, viral vectors based on many different viruses have been developed, and their performance and pathogenicity has been evaluated in animal models. The results of these studies form the basis for the first clinical trials for correcting genetic disorders using retroviral, adenoviral, and adeno-associated viral vectors. Even though the results of these trials are encouraging, vector development is still required to improve and refine future treatment of hereditary disorders.
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Affiliation(s)
- Neeltje A Kootstra
- Laboratory of Genetics, The Salk Institute, La Jolla, California 92037-1099, USA.
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17
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Nakai H, Storm TA, Fuess S, Kay MA. Pathways of removal of free DNA vector ends in normal and DNA-PKcs-deficient SCID mouse hepatocytes transduced with rAAV vectors. Hum Gene Ther 2003; 14:871-81. [PMID: 12828858 DOI: 10.1089/104303403765701169] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Elucidation of the mechanisms of transformation of single-stranded (ss) recombinant adeno-associated virus (rAAV) vector genomes into a variety of stable double-stranded (ds) forms is key to a complete understanding of rAAV vector transduction in vivo. Ds monomer genome formation and cellular ds DNA break (DSB) repair pathways that remove free vector ends toxic to cells, presumably play a central role in this process. By delivering rAAV and naked ds linear DNA vectors into livers of DNA-dependent protein kinase catalytic subunit (DNA-PKcs)-deficient severe combined immunodeficiency (SCID) and wild-type mice, we demonstrate the presence of three major pathways for free ds vector end removal: (1) DNA-PKcs-dependent self-circularization, (2) DNA-PKcs-independent self-circularization, and (3) DNA-PKcs-independent concatemerization. By using the DNA-PKcs-independent pathways, mouse hepatocytes efficiently removed free ds rAAV vector ends even in the absence of DNA-PKcs. Our studies suggest a hierarchical organization of these processes; self-circularization is the preferred pathway over concatemerization, although the former has a limited capacity to remove free vector ends. These studies shed new light on the molecular mechanisms of rAAV vector transduction in vivo.
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Affiliation(s)
- Hiroyuki Nakai
- Departments of Pediatrics and Genetics, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA
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18
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Weber M, Rabinowitz J, Provost N, Conrath H, Folliot S, Briot D, Chérel Y, Chenuaud P, Samulski J, Moullier P, Rolling F. Recombinant adeno-associated virus serotype 4 mediates unique and exclusive long-term transduction of retinal pigmented epithelium in rat, dog, and nonhuman primate after subretinal delivery. Mol Ther 2003; 7:774-81. [PMID: 12788651 DOI: 10.1016/s1525-0016(03)00098-4] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
We previously described chimeric recombinant adeno-associated virus (rAAV) vectors 2/4 and 2/5 as the most efficient vectors in rat retina. We now characterize these two vectors carrying the CMV.gfp genome following subretinal injection in the Wistar rat, beagle dog, and cynomolgus macaque. Both serotypes displayed stable GFP expression for the duration of the experiment (6 months) in all three animal models. Similar to the AAV-2 serotype, AAV-2/5 transduced both RPE and photoreceptor cells, with higher level of transduction in photoreceptors, whereas rAAV-2/4 transduction was unambiguously restricted to RPE cells. This unique specificity found conserved among all three species makes AAV-2/4-derived vectors attractive for retinal diseases originating in RPE such as Leber congenital amaurosis (RPE65) or retinitis pigmentosa due to a mutated mertk gene. To provide further important preclinical data, vector shedding was monitored by PCR in various biological fluids for 2 months post-rAAV administration. Following rAAV-2/4 and -5 subretinal delivery in dogs (n = 6) and in nonhuman primates (n = 2), vector genome was found in lacrymal and nasal fluids for up to 3-4 days and in the serum for up to 15-20 days. Overall, these findings will have a practical impact on the development of future gene therapy trials of retinal diseases.
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Affiliation(s)
- Michel Weber
- Laboratoire de Thérapie Génique, INSERM ERM01-05, CHU-Hotel DIEU, Bat. J. Monnet, 30 Avenue J. Monnet, 44035, Nantes Cedex 01, France
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19
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Jooss K, Chirmule N. Immunity to adenovirus and adeno-associated viral vectors: implications for gene therapy. Gene Ther 2003; 10:955-63. [PMID: 12756416 DOI: 10.1038/sj.gt.3302037] [Citation(s) in RCA: 224] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Viral vectors have provided effective methods for in vivo gene delivery for therapeutic purposes. The ability of viruses to infect a wide variety of cell types in vivo has been exploited for several applications, such as liver, lung, muscle, brain, eye and many others. Immune responses directed towards the viral capsids and the transgene products have severely affected the ability of these vectors to induce long-term gene expression. This paper reviews the influence of viral vectors on antigen-presenting cells (APC), which are central to the induction of innate as well as adaptive immune responses. In this respect, we have focused on adenovirus and adeno-associated viruses because of the polar responses these vector systems induce in vivo. While adenovirus vector can induce significant inflammatory responses, adeno-associated viral vectors are characterized by their inability to consistantly induce immune responses to the transgene product. Understanding the mechanism of infection, transduction and activation of APC by viral vectors will provide strategies to develop safe vectors and prevent immune responses in gene therapies.
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Affiliation(s)
- K Jooss
- Cell Genesys, South San Francisco, CA 94404, USA
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20
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Schnepp BC, Clark KR, Klemanski DL, Pacak CA, Johnson PR. Genetic fate of recombinant adeno-associated virus vector genomes in muscle. J Virol 2003; 77:3495-504. [PMID: 12610125 PMCID: PMC149530 DOI: 10.1128/jvi.77.6.3495-3504.2003] [Citation(s) in RCA: 173] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2002] [Accepted: 12/18/2002] [Indexed: 11/20/2022] Open
Abstract
Recombinant adeno-associated virus (rAAV) vectors are promising human gene transfer vectors, because they mediate long-term gene expression in vivo. The vector DNA form responsible for sustained gene expression has not been clearly defined, but it has been presumed that the vector integrates to some degree and persists in this manner. Using two independent methods, we were unable to identify rAAV integrants in mouse muscle. In the first approach, we were unable to recover host cell-vector DNA junctions from a lambda phage library generated using transduced mouse muscle DNA that contained a high vector copy number. Following this result, we devised a PCR assay based on the principle that integrated rAAV vector sequences could be amplified using primers specific for mouse interspersed repetitive sequences (B1 elements). Using this assay, we analyzed transduced mouse muscle DNA isolated from 6 to 57 weeks after injection and did not detect amplification above background levels. Based on the demonstrated sensitivity of the assay, these results suggested that >99.5% of vector DNA was not integrated. Additional analyses using a novel DNA exonuclease showed that the majority of the rAAV vector DNA in muscle persisted over time as transcriptionally active monomeric and concatameric episomes.
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Affiliation(s)
- Bruce C Schnepp
- Columbus Children's Research Institute, Columbus Children's Hospital, and Department of Pediatrics, College of Medicine and Public Health, The Ohio State University, Columbus, Ohio 43205, USA
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21
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Abstract
Recombinant adenovirus (rAd) and recombinant adeno-associated virus (rAAV) are among the most extensively used vectors in gene therapy studies to date. These two vectors share some similar features such as a broad host range and ability to infect both proliferating and quiescent cells. However, they also possess their own unique set of properties that render them particularly attractive for gene therapy applications. rAd vectors can accommodate larger inserts, mediate transient but high levels of protein expression, and can be easily produced at high titers. Development of gutted rAd vectors has further increased the cloning capacity of these vectors. The gaining popularity of rAAV use in gene therapy can be attributed to its lack of pathogenicity and added safety due to its replication defectiveness, and its ability to mediate long-term expression in a variety of tissues. Site-specific integration, as occurs with wild-type AAV, will be a unique and valuable feature if incorporated into rAAV vectors, further improving their safety. This paper describes these properties of rAd and rAAV vectors, and discusses further development and vector improvements that continue to extend the utility of these vectors, such as cell retargeting by capsid modification, differential transduction by use of serotypes, and extension of the cloning capacity of rAAV vectors by dual vector heterodimerization.
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Affiliation(s)
- Chooi May Lai
- Centre for Ophthalmology and Visual Science, University of Western Australia, Nedlands, Western Australia
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22
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Saaristo A, Veikkola T, Tammela T, Enholm B, Karkkainen MJ, Pajusola K, Bueler H, Ylä-Herttuala S, Alitalo K. Lymphangiogenic gene therapy with minimal blood vascular side effects. J Exp Med 2002; 196:719-30. [PMID: 12235206 PMCID: PMC2194057 DOI: 10.1084/jem.20020587] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Recent work from many laboratories has demonstrated that the vascular endothelial growth factor-C/VEGF-D/VEGFR-3 signaling pathway is crucial for lymphangiogenesis, and that mutations of the Vegfr3 gene are associated with hereditary lymphedema. Furthermore, VEGF-C gene transfer to the skin of mice with lymphedema induced a regeneration of the cutaneous lymphatic vessel network. However, as is the case with VEGF, high levels of VEGF-C cause blood vessel growth and leakiness, resulting in tissue edema. To avoid these blood vascular side effects of VEGF-C, we constructed a viral vector for a VEGFR-3-specific mutant form of VEGF-C (VEGF-C156S) for lymphedema gene therapy. We demonstrate that VEGF-C156S potently induces lymphangiogenesis in transgenic mouse embryos, and when applied via viral gene transfer, in normal and lymphedema mice. Importantly, adenoviral VEGF-C156S lacked the blood vascular side effects of VEGF and VEGF-C adenoviruses. In particular, in the lymphedema mice functional cutaneous lymphatic vessels of normal caliber and morphology were detected after long-term expression of VEGF-C156S via an adeno associated virus. These results have important implications for the development of gene therapy for human lymphedema.
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Affiliation(s)
- Anne Saaristo
- Molecular/Cancer Biology Laboratory and Ludwig Institute for Cancer Research, Biomedicum Helsinki, Helsinki University Central Hospital, University of Helsinki, Finland
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23
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Abstract
Injury-induced downregulation of neurotrophin receptors may limit the response of neurons to trophic factors, compromising their ability to survive. We tested this hypothesis in a model of CNS injury: retinal ganglion cell (RGC) death after transection of the adult rat optic nerve. TrkB mRNA rapidly decreased in axotomized RGCs to approximately 50% of the level in intact retinas. TrkB gene transfer into RGCs combined with exogenous BDNF administration markedly increased neuronal survival: 76% of RGCs remained alive at 2 weeks after axotomy, a time when >90% of these neurons are lost without treatment. Activation of mitogen-activated protein kinase, but not phosphatidylinositol-3 kinase, was required for TrkB-induced survival. These data provide proof-of-principle that enhancing the capacity of injured neurons to respond to trophic factors can be an effective neuroprotective strategy in the adult CNS.
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24
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Zaiss AK, Liu Q, Bowen GP, Wong NCW, Bartlett JS, Muruve DA. Differential activation of innate immune responses by adenovirus and adeno-associated virus vectors. J Virol 2002; 76:4580-90. [PMID: 11932423 PMCID: PMC155101 DOI: 10.1128/jvi.76.9.4580-4590.2002] [Citation(s) in RCA: 281] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Adenovirus vectors induce acute inflammation of infected tissues due to activation of the innate immune system and expression of numerous chemokines and cytokines in transduced target cells. In contrast, adeno-associated virus (AAV) vectors are not associated with significant inflammation experimentally or clinically. We tested the ability of AAV vectors to induce the expression of chemokines in vitro and to activate the innate immune system in vivo. In human HeLa cells and murine renal epithelium-derived cells (REC cells) the adenovirus vector AdlacZ induced the expression of multiple inflammatory chemokines including RANTES, interferon-inducible protein 10 (IP-10), interleukin-8 (IL-8), MIP-1beta, and MIP-2 in a dose-dependent manner. The use of AAVlacZ did not induce the expression of these chemokines above baseline levels despite 40-fold-greater titers than AdlacZ and greater amounts of intracellular AAVlacZ genomes according to Southern and slot blot analysis. This finding confirmed that the lack of AAVlacZ induction of chemokine was not due to reduced transduction. In DBA/2 mice, the intravenous administration of 2.5 x 10(11) particles of AAVlacZ resulted in the rapid induction of liver tumor necrosis factor alpha (TNF-alpha), RANTES, IP-10, MIP-1beta, MCP-1, and MIP-2 mRNAs. However, 6 h following injection, chemokine mRNA levels returned to baseline. As expected, administration of 10-fold less AdlacZ caused an induction of liver TNF-alpha and chemokine mRNAs that persisted for more than 24 h posttransduction. Whereas intravenous administration of 2.5 x 10(11) particles of AAVlacZ triggered a transient infiltration of neutrophils and CD11b(+) cells into liver, this response stood in contrast to widespread inflammation and toxicity induced by AdlacZ. Kupffer cell depletion abolished AAVlacZ but not AdlacZ-induced chemokine expression and neutrophil infiltration. In summary, these results show that AAV vectors activate the innate immune system to a lesser extent than do adenovirus vectors and offer a possible explanation for the reduced inflammatory properties of AAV compared to adenovirus vectors.
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Affiliation(s)
- Anne-Kathrin Zaiss
- Department of Biochemistry and Molecular Biology, Department of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada, Department of Pediatrics, Ohio State University, Children's Research Institute, Children's Hospital, Columbus, Ohio
| | - Qiang Liu
- Department of Biochemistry and Molecular Biology, Department of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada, Department of Pediatrics, Ohio State University, Children's Research Institute, Children's Hospital, Columbus, Ohio
| | - Gloria P. Bowen
- Department of Biochemistry and Molecular Biology, Department of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada, Department of Pediatrics, Ohio State University, Children's Research Institute, Children's Hospital, Columbus, Ohio
| | - Norman C. W. Wong
- Department of Biochemistry and Molecular Biology, Department of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada, Department of Pediatrics, Ohio State University, Children's Research Institute, Children's Hospital, Columbus, Ohio
| | - Jeffrey S. Bartlett
- Department of Biochemistry and Molecular Biology, Department of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada, Department of Pediatrics, Ohio State University, Children's Research Institute, Children's Hospital, Columbus, Ohio
| | - Daniel A. Muruve
- Department of Biochemistry and Molecular Biology, Department of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada, Department of Pediatrics, Ohio State University, Children's Research Institute, Children's Hospital, Columbus, Ohio
- Corresponding author. Mailing address: Faculty of Medicine, University of Calgary, 3330 Hospital Dr. NW, Calgary, AB T2N 4N1, Canada. Phone: (403) 220-3908. Fax: (403) 270-0979. E-mail:
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25
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Monahan PE, Jooss K, Sands MS. Safety of adeno-associated virus gene therapy vectors: a current evaluation. Expert Opin Drug Saf 2002; 1:79-91. [PMID: 12904163 DOI: 10.1517/14740338.1.1.79] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
An increasing number of strategies for molecular treatment of disease rely on the adeno-associated virus (AAV) as a therapeutic gene delivery vector. One of the most attractive features of this viral DNA vector is the perceived safety of AAV gene delivery. Recent applications in human clinical trials support the safety record established in preclinical trials, with evidence of gene transfer in the absence of cellular immune responses or tissue disturbance. Nevertheless, many aspects of the biology of the wild type AAV and its derivatives are still being explored. While the therapeutic potential of novel recombinant AAV therapeutics appears promising, recent insights suggest aspects of their pharmacokinetics, biodistribution and toxicity that require consideration to achieve the safest application of these molecular medicines.
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Affiliation(s)
- Paul E Monahan
- Gene Therapy Center, CB #7220, University of North Carolina-Chapel Hill School of Medicine, 418 MacNider Building, Chapel Hill, NC 27599, USA.
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26
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Soifer H, Higo C, Logg CR, Jih LJL, Shichinohe T, Harboe-Schmidt E, Mitani K, Kasahara N. A novel, helper-dependent, adenovirus-retrovirus hybrid vector: stable transduction by a two-stage mechanism. Mol Ther 2002; 5:599-608. [PMID: 11991751 DOI: 10.1006/mthe.2002.0586] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We have developed a novel vector system that uses a helper-dependent adenoviral vector as a carrier to deliver a fully functional retrovirus vector. The helper-dependent adenovirus (HDAd) can accommodate large inserts, provide high titers, and infect nondividing as well as dividing cells. However, adenoviral DNA is rarely integrated into the host cell genome, and its episomal expression is transient. Therefore we inserted a replication-competent, ecotropic retrovirus vector containing the green fluorescent protein (GFP) reporter gene as a second-stage component. The well-characterized host species tropism of each vector component provided a stringent biological assay system that demonstrates the two-stage transduction mechanism of the hybrid vector, because the adenovirus stage can efficiently transduce human cells but cannot replicate in murine cells, and conversely, the ecotropic retrovirus stage cannot enter human cells but can efficiently proliferate in murine cells, resulting in permanent integration and progressive spread of reporter gene expression.
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Affiliation(s)
- Harris Soifer
- Institute for Genetic Medicine, University of Southern California, 2250 Alcazar Street, CSC-240, Los Angeles, California 90033, USA
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27
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Igarashi T, Miyake K, Suzuki N, Kato K, Takahashi H, Ohara K, Shimada T. New strategy for in vivo transgene expression in corneal epithelial progenitor cells. Curr Eye Res 2002; 24:46-50. [PMID: 12187494 DOI: 10.1076/ceyr.24.1.46.5436] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
PURPOSE Efficient in vivo gene transfer into corneal epithelial cells and stable transgene expression would have broad clinical applications. We therefore assessed the capacity of adenoviral, adeno-associated viral (AAV) and lentiviral vectors encoding enhanced green fluorescent protein (EGFP) to transduce rat corneal epithelial progenitor cells. METHODS Superficial cells of the corneal epithelium were shaved, after which 20 microl of the respective vector solutions were inoculated onto the basal cell layer of the limbal epithelium for 30 min. Results. Three days after transduction, fluorescence microscopic examination revealed the presence of EGFP+ cells in all corneas, irrespective of the vector used; however, EGFP+ cells were undetectable in corneas transduced with adenoviral and AAV vectors after 2 and 4 weeks, respectively. By contrast, EGFP+ cells were still detected among cells transduced with lentiviral vector 6 weeks after transduction. DAPI (4', 6-diamidino-2-phenylindole) staining confirmed that it was the basal layer cells that continued to express EGFP throughout the 6-week period. CONCLUSIONS The use of a lentiviral vector for in vivo transfer of foreign genes into corneal epithelial stem and transient amplifying cells may represent a new and effective approach to the treatment of corneal disease, as well as to the study of the biology of these stem cells.
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Affiliation(s)
- Tsutomu Igarashi
- Department of Biochemistry and Molecular Biology, Nippon Medical School, Tokyo, Japan.
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28
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Lozier JN, Csako G, Mondoro TH, Krizek DM, Metzger ME, Costello R, Vostal JG, Rick ME, Donahue RE, Morgan RA. Toxicity of a first-generation adenoviral vector in rhesus macaques. Hum Gene Ther 2002; 13:113-24. [PMID: 11779415 DOI: 10.1089/10430340152712665] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We constructed a first-generation adenovirus vector (AVC3FIX5) that we used to assess the rhesus macaque as a nonhuman primate model for preclinical testing of hemophilia B gene therapy vectors. Although we succeeded in our primary objective of demonstrating expression of human factor IX we encountered numerous toxic side effects that proved to be dose limiting. Following intravenous administration of AVC3FIX5 at doses of 3.4 x 10(11) vector particles/kg to 3.8 x 10(12) vector particles/kg, the animals in our study developed antibodies against human factor IX, and dose-dependent elevations of enzymes specific for liver, muscle, and lung injury. In addition, these animals showed dose-dependent prolongation of clotting times as well as acute, dose-dependent decreases in platelet counts and concomitant elevation of fibrinogen and von Willebrand factor. These abnormalities may be caused by the direct toxic effects of the adenovirus vector itself, or may result indirectly from the accompanying acute inflammatory response marked by elevations in IL-6, a key regulator of the acute inflammatory response. The rhesus macaque may be a useful animal model in which to evaluate mechanisms of adenovirus toxicities that have been encountered during clinical gene therapy trials.
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Affiliation(s)
- Jay N Lozier
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA.
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29
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Nakai H, Yant SR, Storm TA, Fuess S, Meuse L, Kay MA. Extrachromosomal recombinant adeno-associated virus vector genomes are primarily responsible for stable liver transduction in vivo. J Virol 2001; 75:6969-76. [PMID: 11435577 PMCID: PMC114425 DOI: 10.1128/jvi.75.15.6969-6976.2001] [Citation(s) in RCA: 343] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Recombinant adeno-associated virus (rAAV) vectors stably transduce hepatocytes in experimental animals. Although the vector genomes are found both as extrachromosomes and as chromosomally integrated forms in hepatocytes, the relative proportion of each has not yet been clearly established. Using an in vivo assay based on the induction of hepatocellular regeneration via a surgical two-thirds partial hepatectomy, we have determined the proportion of integrated and extrachromosomal rAAV genomes in mouse livers and their relative contribution to stable gene expression in vivo. Plasma human coagulation factor IX (hF.IX) levels in mice originating from a chromosomally integrated hF.IX-expressing transposon vector remained unchanged with hepatectomy. This was in sharp contrast to what was observed when a surgical partial hepatectomy was performed in mice 6 weeks to 12 months after portal vein injection of a series of hF.IX-expressing rAAV vectors. At doses of 2.4 x 10(11) to 3.0 x 10(11) vector genomes per mouse (n = 12), hF.IX levels and the average number of stably transduced vector genomes per cell decreased by 92 and 86%, respectively, after hepatectomy. In a separate study, one of three mice injected with a higher dose of rAAV had a higher proportion (67%) of integrated genomes, the significance of which is not known. Nevertheless, in general, these results indicate that, in most cases, no more than approximately 10% of stably transduced genomes integrated into host chromosomes in vivo. Additionally, the results demonstrate that extrachromosomal, not integrated, genomes are the major form of rAAV in the liver and are the primary source of rAAV-mediated gene expression. This small fraction of integrated genomes greatly decreases the potential risk of vector-related insertional mutagenesis associated with all integrating vectors but also raises uncertainties as to whether rAAV-mediated hepatic gene expression can persist lifelong after a single vector administration.
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Affiliation(s)
- H Nakai
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California 94305, USA
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30
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Lai YK, Rolling F, Baker E, Rakoczy PE. Kinetics of efficient recombinant adeno-associated virus transduction in retinal pigment epithelial cells. Exp Cell Res 2001; 267:184-92. [PMID: 11426937 DOI: 10.1006/excr.2001.5236] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aim of this study was to investigate the premise that retinal pigment epithelial (RPE) cells are more permissive to recombinant adeno-associated virus (rAAV) transduction than other cells. We investigated the kinetics and mechanisms of rAAV transduction in RPE cells and found that the transduction efficiencies of cultured RPE cells HRPE51 and ARPE19 were significantly higher than those of 293 (P < 0.008) and HeLa (P < 0.025) cells. In addition, RPE cells reached maximum transduction efficiency at a much lower m.o.i. (m.o.i. 10) than 293 cells (m.o.i. 25). Competition experiments using 1 microg/ml heparin inhibited the high level of transduction in RPE cells by 30%, but additional heparin failed to reduce rAAV transduction further. Southern hybridization of low-molecular-weight DNA from transduced RPE cells indicated that 42% of single-stranded rAAV DNA was translocated into the nucleus by 2 h postinfection. By 6 h postinfection, double-stranded rAAV DNA was observed, which coincided with the onset of transgene expression. Southern and fluorescence in situ hybridization of total genomic DNA indicated that long-term transgene expression in RPE cells was maintained by the integration of rAAV into the cellular chromosome. Together, these results suggest that the high permissiveness of RPE cells is not related to the presence of heparan sulfate receptors or nuclear trafficking but may be due to an enhanced rate of second-strand synthesis and that integration in RPE cells is responsible for long-term transgene expression.
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Affiliation(s)
- Y K Lai
- Centre for Ophthalmology and Visual Science, University of Western Australia, Nedlands, Western Australia, Australia
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31
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Bonadio J. Tissue engineering via local gene delivery: update and future prospects for enhancing the technology. Adv Drug Deliv Rev 2000; 44:185-94. [PMID: 11072114 DOI: 10.1016/s0169-409x(00)00094-6] [Citation(s) in RCA: 126] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
This review describes the status of a local plasmid-based gene transfer technology known as the gene activated matrix (GAM). Studies over the past 6 years suggest that GAM may serve as a platform technology for local gene delivery in the wound bed of various tissues and organs. These studies demonstrated that plasmid encoding genes can be delivered to acutely injured tendon, ligament, bone, muscle, skin and nerve. Moreover, direct in vivo transfer of therapeutic plasmid encoding genes in bone, skin and nerve was associated with a significant regenerative response relative to sham controls. The review also describes new technology that should enhance the potential of local gene delivery in a manner consistent with the risk-benefit profile associated with tissue engineering applications.
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Affiliation(s)
- J Bonadio
- Selective Genetics Inc., 6046 Cornerstone Court West, Suite 107, San Diego, CA 92121, USA.
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32
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Monahan PE, Samulski RJ. Adeno-associated virus vectors for gene therapy: more pros than cons? MOLECULAR MEDICINE TODAY 2000; 6:433-40. [PMID: 11074369 DOI: 10.1016/s1357-4310(00)01810-4] [Citation(s) in RCA: 168] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Gene therapy vectors based on the adeno-associated virus (AAV) are being developed for a widening variety of therapeutic applications. Enthusiasm for AAV is due, not only to the relative safety of these vectors, but also to advances in understanding of the unique biology of this virus. This review examines a number of long-standing concerns regarding the utility of AAV for gene transfer in light of many new insights into the biology, immunology and production of AAV.
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Affiliation(s)
- P E Monahan
- Division of Hematology/Oncology and Gene Therapy Center, University of North Carolina at Chapel Hill School of Medicine, CB#7352, Thurston-Bowles Bldg, Chapel Hill, NC 27599, USA.
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