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Sample records for adeno-associated viral gene

  1. Adeno-associated viral vectors for clinical gene transfer studies.

    PubMed

    Snyder, Richard O; Francis, Joyce

    2005-06-01

    Recombinant adeno-associated viral (rAAV) vectors can mediate the safe and long-term correction of genetic diseases in animal models following a single administration. These pre-clinical studies are the basis of human trials that have shown rAAV vector persistence and safety in humans following delivery to lung, sinus, skeletal muscle, brain and liver. Transient disease correction has also been demonstrated in humans treated for hemophilia B and cystic fibrosis using AAV2 vectors. The physiochemical properties of rAAV vector virions are amenable to industry accepted manufacturing methodologies, long-term storage and direct in vivo administration. Recombinant adeno-associated virus vectors are manufactured in compliance with current Good Manufacturing Practices (cGMPs) as outlined in the Code of Federal Regulations (21CFR). To meet these requirements, manufacturing controls and quality systems are established, including 1) adequate facilities and equipment, 2) personnel who have relevant education or experience and are trained for specific assigned duties, 3) raw materials that are qualified for use and 4) a process (including production, purification, formulation, filling, storage and shipping) that is controlled, aseptic, reliable and consistent. Quality systems including Quality Control (QC) and Quality Assurance (QA) are also implemented. These manufacturing procedures and quality systems are designed so the product meets its release specifications to ensure that patients receive a safe, pure, potent and stable investigational drug. PMID:15975008

  2. [Adeno-associated viral vectors: methods for production and purification for gene therapy applications].

    PubMed

    Mena-Enriquez, Mayra; Flores-Contreras, Lucia; Armendáriz-Borunda, Juan

    2012-01-01

    Viral vectors based on adeno-associated virus (AAV) are widely used in gene therapy protocols, because they have characteristics that make them valuable for the treatment of genetic and chronic degenerative diseases. AAV2 serotype had been the best characterized to date. However, the AAV vectors developed from other serotypes is of special interest, since they have organ-specific tropism which increases their potential for transgene delivery to target cells for performing their therapeutic effects. This article summarizes AAV generalities, methods for their production and purification. It also discusses the use of these vectors in vitro, in vivo and their application in gene therapy clinical trials. PMID:23544311

  3. The potential of adeno-associated viral vectors for gene delivery to muscle tissue

    PubMed Central

    Nahid, M Abu; Gao, Guangping

    2014-01-01

    Introduction Muscle-directed gene therapy is rapidly gaining attention primarily because muscle is an easily accessible target tissue and is also associated with various severe genetic disorders. Localized and systemic delivery of recombinant adeno-associated virus (rAAV) vectors of several serotypes results in very efficient transduction of skeletal and cardiac muscles, which has been achieved in both small and large animals, as well as in humans. Muscle is the target tissue in gene therapy for many muscular dystrophy diseases, and may also be exploited as a biofactory to produce secretory factors for systemic disorders. Current limitations of using rAAVs for muscle gene transfer include vector size restriction, potential safety concerns such as off-target toxicity and the immunological barrier composing of pre-existing neutralizing antibodies and CD8+ T-cell response against AAV capsid in humans. Areas covered In this article, we will discuss basic AAV vector biology and its application in muscle-directed gene delivery, as well as potential strategies to overcome the aforementioned limitations of rAAV for further clinical application. Expert opinion Delivering therapeutic genes to large muscle mass in humans is arguably the most urgent unmet demand in treating diseases affecting muscle tissues throughout the whole body. Muscle-directed, rAAV-mediated gene transfer for expressing antibodies is a promising strategy to combat deadly infectious diseases. Developing strategies to circumvent the immune response following rAAV administration in humans will facilitate clinical application. PMID:24386892

  4. Gene therapy for choroideremia using an adeno-associated viral (AAV) vector.

    PubMed

    Barnard, Alun R; Groppe, Markus; MacLaren, Robert E

    2015-03-01

    Choroideremia is an outer retinal degeneration with a characteristic clinical appearance that was first described in the nineteenth century. The disorder begins with reduction of night vision and gradually progresses to blindness by middle age. The appearance of the fundus in sufferers is recognizable by the characteristic pale color caused by the loss of the outer retina, retinal-pigmented epithelium, and choroidal vessels, leading to exposure of the underlying sclera. Choroideremia shows X-linked recessive inheritance and the choroideremia gene (CHM) was one of the first to be identified by positional cloning in 1990. Subsequent identification and characterization of the CHM gene, which encodes Rab escort protein 1 (REP1), has led to better comprehension of the disease and enabled advances in genetic diagnosis. Despite several decades of work to understand the exact pathogenesis, no established treatments currently exist to stop or even slow the progression of retinal degeneration in choroideremia. Encouragingly, several specific molecular and clinical features make choroideremia an ideal candidate for treatment with gene therapy. This work describes the considerations and challenges in the development of a new clinical trial using adeno-associated virus (AAV) encoding the CHM gene. PMID:25359548

  5. Adeno Associated Viral Vector Delivered RNAi for Gene Therapy of SOD1 Amyotrophic Lateral Sclerosis

    PubMed Central

    Stoica, Lorelei; Sena-Esteves, Miguel

    2016-01-01

    Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease caused by progressive loss of upper and lower motor neurons. Mutations in superoxide dismutase 1 (SOD1) are a leading cause of ALS, responsible for up to 20% of familial cases. Although the exact mechanism by which mutant SOD1 causes disease remains unknown, multiple studies have shown that reduction of the mutant species leads to delayed disease onset and extension of lifespan of animal models. This makes SOD1 an ideal target for gene therapy coupling adeno associated virus vector (AAV) gene delivery with RNAi molecules. In this review we summarize the studies done thus far attempting to decrease SOD1 gene expression, using AAV vectors as delivery tools, and RNAi as therapeutic molecules. Current hurdles to be overcome, such as the need for widespread gene delivery through the entire central nervous system (CNS), are discussed. Continued efforts to improve current AAV delivery methods and capsids will accelerate the application of these therapeutics to the clinic. PMID:27531973

  6. Adeno Associated Viral Vector Delivered RNAi for Gene Therapy of SOD1 Amyotrophic Lateral Sclerosis.

    PubMed

    Stoica, Lorelei; Sena-Esteves, Miguel

    2016-01-01

    Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease caused by progressive loss of upper and lower motor neurons. Mutations in superoxide dismutase 1 (SOD1) are a leading cause of ALS, responsible for up to 20% of familial cases. Although the exact mechanism by which mutant SOD1 causes disease remains unknown, multiple studies have shown that reduction of the mutant species leads to delayed disease onset and extension of lifespan of animal models. This makes SOD1 an ideal target for gene therapy coupling adeno associated virus vector (AAV) gene delivery with RNAi molecules. In this review we summarize the studies done thus far attempting to decrease SOD1 gene expression, using AAV vectors as delivery tools, and RNAi as therapeutic molecules. Current hurdles to be overcome, such as the need for widespread gene delivery through the entire central nervous system (CNS), are discussed. Continued efforts to improve current AAV delivery methods and capsids will accelerate the application of these therapeutics to the clinic. PMID:27531973

  7. Systemic delivery of genes to striated muscles using adeno-associated viral vectors.

    PubMed

    Gregorevic, Paul; Blankinship, Michael J; Allen, James M; Crawford, Robert W; Meuse, Leonard; Miller, Daniel G; Russell, David W; Chamberlain, Jeffrey S

    2004-08-01

    A major obstacle limiting gene therapy for diseases of the heart and skeletal muscles is an inability to deliver genes systemically to muscles of an adult organism. Systemic gene transfer to striated muscles is hampered by the vascular endothelium, which represents a barrier to distribution of vectors via the circulation. Here we show the first evidence of widespread transduction of both cardiac and skeletal muscles in an adult mammal, after a single intravenous administration of recombinant adeno-associated virus pseudotype 6 vectors. The inclusion of vascular endothelium growth factor/vascular permeability factor, to achieve acute permeabilization of the peripheral microvasculature, enhanced tissue transduction at lower vector doses. This technique enabled widespread muscle-specific expression of a functional micro-dystrophin in the skeletal muscles of dystrophin-deficient mdx mice, which model Duchenne muscular dystrophy. We propose that these methods may be applicable for systemic delivery of a wide variety of genes to the striated muscles of adult mammals. PMID:15273747

  8. Designer Gene Delivery Vectors: Molecular Engineering and Evolution of Adeno-Associated Viral Vectors for Enhanced Gene Transfer

    PubMed Central

    Kwon, Inchan

    2007-01-01

    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. PMID:17763830

  9. Adeno-Associated Viral-Mediated LARGE Gene Therapy Rescues the Muscular Dystrophic Phenotype in Mouse Models of Dystroglycanopathy

    PubMed Central

    Yu, Miao; He, Yonglin; Wang, Kejian; Zhang, Peng; Zhang, Shengle

    2013-01-01

    Abstract Dystroglycanopathies are a group of congenital muscular dystrophies (CMD) often caused by mutations in genes encoding glycosyltransferases that lead to hypoglycosylation of α-dystroglycan (α-DG) and reduce its extracellular matrix-binding activity. Overexpressing LARGE (formerly known as like-glycosyltransferase) generates an extracellular matrix-binding carbohydrate epitope in cells with CMD-causing mutations in not only LARGE but also other glycosyltransferases, including POMT1, POMGnT1, and fukutin, creating the possibilities of a one-for-all gene therapy. To determine the feasibility of LARGE gene therapy, a serotype 9 adeno-associated viral vector for overexpressing LARGE (AAV9-LARGE) was injected intracardially into newborns of two mouse models of CMD: the natural LARGE mutant Largemyd mice and protein O-mannose N-acetylglucosaminyltransferase 1 (POMGnT1) knockout mice. AAV9-LARGE virus treatment yielded partial restoration of α-DG glycosylation and ligand-binding activity. The muscular dystrophy phenotype in skeletal muscles was ameliorated as revealed by significantly reduced fibrosis, necrosis, and numbers of centrally located nuclei with improved motor function. These results indicate that LARGE overexpression in vivo by AAV9-mediated gene therapy is effective at restoring functional glycosylation of α-DG and rescuing the muscular dystrophy phenotype in deficiency of not only LARGE but also POMGnT1, providing evidence that in vivo LARGE gene therapy may be broadly useful in dystroglycanopathies. PMID:23379513

  10. Novel adeno-associated viral vector delivering the utrophin gene regulator jazz counteracts dystrophic pathology in mdx mice.

    PubMed

    Strimpakos, Georgios; Corbi, Nicoletta; Pisani, Cinzia; Di Certo, Maria Grazia; Onori, Annalisa; Luvisetto, Siro; Severini, Cinzia; Gabanella, Francesca; Monaco, Lucia; Mattei, Elisabetta; Passananti, Claudio

    2014-09-01

    Over-expression of the dystrophin-related gene utrophin represents a promising therapeutic strategy for Duchenne muscular dystrophy (DMD). The strategy is based on the ability of utrophin to functionally replace defective dystrophin. We developed the artificial zinc finger transcription factor "Jazz" that up-regulates both the human and mouse utrophin promoter. We observed a significant recovery of muscle strength in dystrophic Jazz-transgenic mdx mice. Here we demonstrate the efficacy of an experimental gene therapy based on the systemic delivery of Jazz gene in mdx mice by adeno-associated virus (AAV). AAV serotype 8 was chosen on the basis of its high affinity for skeletal muscle. Muscle-specific expression of the therapeutic Jazz gene was enhanced by adding the muscle α-actin promoter to the AAV vector (mAAV). Injection of mAAV8-Jazz viral preparations into mdx mice resulted in muscle-specific Jazz expression coupled with up-regulation of the utrophin gene. We show a significant recovery from the dystrophic phenotype in mAAV8-Jazz-treated mdx mice. Histological and physiological analysis revealed a reduction of fiber necrosis and inflammatory cell infiltration associated with functional recovery in muscle contractile force. The combination of ZF-ATF technology with the AAV delivery can open a new avenue to obtain a therapeutic strategy for treatment of DMD. PMID:24469912

  11. Adeno-associated viral-mediated LARGE gene therapy rescues the muscular dystrophic phenotype in mouse models of dystroglycanopathy.

    PubMed

    Yu, Miao; He, Yonglin; Wang, Kejian; Zhang, Peng; Zhang, Shengle; Hu, Huaiyu

    2013-03-01

    Dystroglycanopathies are a group of congenital muscular dystrophies (CMD) often caused by mutations in genes encoding glycosyltransferases that lead to hypoglycosylation of α-dystroglycan (α-DG) and reduce its extracellular matrix-binding activity. Overexpressing LARGE (formerly known as like-glycosyltransferase) generates an extracellular matrix-binding carbohydrate epitope in cells with CMD-causing mutations in not only LARGE but also other glycosyltransferases, including POMT1, POMGnT1, and fukutin, creating the possibilities of a one-for-all gene therapy. To determine the feasibility of LARGE gene therapy, a serotype 9 adeno-associated viral vector for overexpressing LARGE (AAV9-LARGE) was injected intracardially into newborns of two mouse models of CMD: the natural LARGE mutant Large(myd) mice and protein O-mannose N-acetylglucosaminyltransferase 1 (POMGnT1) knockout mice. AAV9-LARGE virus treatment yielded partial restoration of α-DG glycosylation and ligand-binding activity. The muscular dystrophy phenotype in skeletal muscles was ameliorated as revealed by significantly reduced fibrosis, necrosis, and numbers of centrally located nuclei with improved motor function. These results indicate that LARGE overexpression in vivo by AAV9-mediated gene therapy is effective at restoring functional glycosylation of α-DG and rescuing the muscular dystrophy phenotype in deficiency of not only LARGE but also POMGnT1, providing evidence that in vivo LARGE gene therapy may be broadly useful in dystroglycanopathies. PMID:23379513

  12. Inner Ear Gene Transfection in Neonatal Mice Using Adeno-Associated Viral Vector: A Comparison of Two Approaches

    PubMed Central

    Xia, Li; Yin, Shankai; Wang, Jian

    2012-01-01

    Local gene transfection is a promising technique for the prevention and/or correction of inner ear diseases, particularly those resulting from genetic defects. Adeno-associated virus (AAV) is an ideal viral vector for inner ear gene transfection because of its safety, stability, long-lasting expression, and its high tropism for many different cell types. Recently, a new generation of AAV vectors with a tyrosine mutation (mut-AAV) has demonstrated significant improvement in transfection efficiency. A method for inner ear gene transfection via the intact round window membrane (RWM) has been developed in our laboratory. This method has not been tested in neonatal mice, an important species for the study of inherited hearing loss. Following a preliminary study to optimize the experimental protocol in order to reduce mortality, the present study investigated inner ear gene transfection in mice at postnatal day 7. We compared transfection efficiency, the safety of the scala tympani injection via RWM puncture, and the trans-RWM diffusion following partial digestion with an enzyme technique. The results revealed that approximately 47% of inner hair cells (IHCs) and 17% of outer hair cells (OHCs) were transfected via the trans-RWM approach. Transfection efficiency via RWM puncture (58% and 19% for IHCs and OHCs, respectively) was slightly higher, but the difference was not significant. PMID:22912830

  13. Efficient Transduction of Corneal Stroma by Adeno-Associated Viral Serotype Vectors for Implications in Gene Therapy of Corneal Diseases.

    PubMed

    Lu, Yi; Ai, Jianzhong; Gessler, Dominic; Su, Qin; Tran, Karen; Zheng, Qiang; Xu, Xun; Gao, Guangping

    2016-08-01

    Corneal disease is one of the leading causes of blindness worldwide. Gene therapy is an attractive therapeutic strategy for corneal diseases, but currently underdeveloped. Recombinant adeno-associated viral (rAAV) vectors have emerged as a highly promising gene therapy platform. This study aims to identify rAAV vectors that can efficiently transduce corneal stroma for potential applications in studying pathophysiology of corneal diseases and therapeutic development. We characterized 14 rAAV serotypes expressing enhanced green fluorescent protein (EGFP), for cell specificity and transduction efficiency after either intrastromal injection or topical administration in mouse corneas in vivo. Our results show that intrastromal injections of rAAVrh.8, rAAVrh.10, rAAVrh.39, and rAAVrh.43 efficiently transduce mouse corneal stroma in vivo, and that topical administrations of rAAVrh.10 and rAAVrh.39 subsequent to epithelial scraping generate detectable transgene expression. In vivo imaging analysis revealed that transgene expression became detectable by 1 week postadministration, peaked at 2 weeks, and lasted for the duration of the study (i.e., 4 weeks). Both rAAVrh.10 and rAAVrh.39 transduced more than 50% of keratocytes, the major cell type in the corneal stroma, by intrastromal injection and 30% by topical administration. Histopathology indicated that rAAV transduction of cornea caused no morphological adverse effects. Overall, our findings suggest that some rAAV serotype vectors can efficiently transduce corneal stroma in vivo, constituting a potentially powerful and safe gene delivery platform for gene therapy of corneal diseases. PMID:27001051

  14. Identification of adeno-associated viral vectors suitable for intestinal gene delivery and modulation of experimental colitis.

    PubMed

    Polyak, Steven; Mach, Annette; Porvasnik, Stacy; Dixon, Lisa; Conlon, Thomas; Erger, Kirsten E; Acosta, Andres; Wright, Amy J; Campbell-Thompson, Martha; Zolotukhin, Irene; Wasserfall, Clive; Mah, Cathryn

    2012-02-01

    Effective gene transfer with sustained gene expression is an important adjunct to the study of intestinal inflammation and future therapy in inflammatory bowel disease. Recombinant adeno-associated virus (AAV) vectors are ideal for gene transfer and long-term transgene expression. The purpose of our study was to identify optimal AAV pseudotypes for transduction of the epithelium in the small intestine and colon, which could be used for studies in experimental colitis. The tropism and transduction efficiencies of AAV pseudotypes 1-10 were examined in murine small intestine and colon 8 wk after administration by real-time PCR and immunohistochemistry. The clinical and histopathological effects of IL-10-mediated intestinal transduction delivered by AAVrh10 were examined in the murine IL-10⁻/⁻ enterocolitis model. Serum IL-10 levels and IL-10 expression were followed by ELISA and real-time PCR, respectively. AAV pseudotypes 4, 7, 8, 9, and 10 demonstrated optimal intestinal transduction. Transgene expression was sustained 8 wk after administration and was frequently observed in enteroendocrine cells. Long-term IL-10 gene expression and serum IL-10 levels were observed following AAV transduction in an IL-10-/- model of enterocolitis. Animals treated with AAVrh10-IL-10 had lower disease activity index scores, higher colon weight-to-length ratios, and lower microscopic inflammation scores. This study identifies novel AAV pseudotypes with small intestine and colon tropism and sustained transgene expression capable of modulating mucosal inflammation in a murine model of enterocolitis. PMID:22114116

  15. Adeno-associated virus for cystic fibrosis gene therapy.

    PubMed

    Martini, S V; Rocco, P R M; Morales, M M

    2011-11-01

    Gene therapy is an alternative treatment for genetic lung disease, especially monogenic disorders such as cystic fibrosis. Cystic fibrosis is a severe autosomal recessive disease affecting one in 2500 live births in the white population, caused by mutation of the cystic fibrosis transmembrane conductance regulator (CFTR). The disease is classically characterized by pancreatic enzyme insufficiency, an increased concentration of chloride in sweat, and varying severity of chronic obstructive lung disease. Currently, the greatest challenge for gene therapy is finding an ideal vector to deliver the transgene (CFTR) to the affected organ (lung). Adeno-associated virus is the most promising viral vector system for the treatment of respiratory disease because it has natural tropism for airway epithelial cells and does not cause any human disease. This review focuses on the basic properties of adeno-associated virus and its use as a vector for cystic fibrosis gene therapy. PMID:21952739

  16. Adeno-associated viral vectors for the treatment of hemophilia.

    PubMed

    High, Katherine A; Anguela, Xavier M

    2016-04-15

    Gene transfer studies for the treatment of hemophilia began more than two decades ago. A large body of pre-clinical work evaluated a variety of vectors and target tissues, but by the start of the new millennium it became evident that adeno-associated viral (AAV)-mediated gene transfer to the liver held great promise as a therapeutic tool. The transition to the clinical arena uncovered a number of unforeseen challenges, mainly in the form of a human-specific immune response against the vector that poses a significant limitation in the application of this technology. While the full nature of this response has not been elucidated, long-term expression of therapeutic levels of factor IX is already a reality for a small number of patients. Extending this success to a greater number of hemophilia B patients remains a major goal of the field, as well as translating this strategy to clinical therapy for hemophilia A. This review summarizes the progress of AAV-mediated gene therapy for the hemophilias, along with its upcoming prospects and challenges. PMID:26614390

  17. Effect of nuclear factor κB inhibition on serotype 9 adeno-associated viral (AAV9) minidystrophin gene transfer to the mdx mouse.

    PubMed

    Reay, Daniel P; Niizawa, Gabriela A; Watchko, Jon F; Daood, Molly; Reay, Ja'Nean C; Raggi, Eugene; Clemens, Paula R

    2012-01-01

    Gene therapy studies for Duchenne muscular dystrophy (DMD) have focused on viral vector-mediated gene transfer to provide therapeutic protein expression or treatment with drugs to limit dystrophic changes in muscle. The pathological activation of the nuclear factor (NF)-κB signaling pathway has emerged as an important cause of dystrophic muscle changes in muscular dystrophy. Furthermore, activation of NF-κB may inhibit gene transfer by promoting inflammation in response to the transgene or vector. Therefore, we hypothesized that inhibition of pathological NF-κB activation in muscle would complement the therapeutic benefits of dystrophin gene transfer in the mdx mouse model of DMD. Systemic gene transfer using serotype 9 adeno-associated viral (AAV9) vectors is promising for treatment of preclinical models of DMD because of vector tropism to cardiac and skeletal muscle. In quadriceps of C57BL/10ScSn-Dmd(mdx)/J (mdx) mice, the addition of octalysine (8K)-NF-κB essential modulator (NEMO)-binding domain (8K-NBD) peptide treatment to AAV9 minidystrophin gene delivery resulted in increased levels of recombinant dystrophin expression suggesting that 8K-NBD treatment promoted an environment in muscle tissue conducive to higher levels of expression. Indices of necrosis and regeneration were diminished with AAV9 gene delivery alone and to a greater degree with the addition of 8K-NBD treatment. In diaphragm muscle, high-level transgene expression was achieved with AAV9 minidystoophin gene delivery alone; therefore, improvements in histological and physiological indices were comparable in the two treatment groups. The data support benefit from 8K-NBD treatment to complement gene transfer therapy for DMD in muscle tissue that receives incomplete levels of transduction by gene transfer, which may be highly significant for clinical applications of muscle gene delivery. PMID:22231732

  18. Large-Scale Production of Adeno-Associated Viral Vector Serotype-9 Carrying the Human Survival Motor Neuron Gene.

    PubMed

    Rashnonejad, Afrooz; Chermahini, Gholamhossein Amini; Li, Shaoyong; Ozkinay, Ferda; Gao, Guangping

    2016-01-01

    Recombinant AAV (rAAV) vectors are a suitable vector for gene therapy studies because of desired characteristics such as low immunogenicity, transfection of non-dividing and dividing cells, and long-term expression of the transgene. In this study, the large-scale production of single stranded (ss) and self-complementary (sc) AAV9 carrying the human survival motor neuron (SMN) gene (AAV9-SMN) suitable for in vivo gene therapy studies of SMA was described. SMN cDNA has been cloned into pAAV-CB6-PI and pAAVsc-CB6-PI with and without its specific UTRs, respectively. Both plasmids bear CMV enhancer/beta-actin (CB) promoter, CMV IE enhancer, and polyadenylation signal sequences. 2.5 μg of constructed pAAV-CB6-PI-SMN and pAAVsc-CB6-PI-SMN cause to, respectively, 4.853- and 2.321-fold increases in SMN protein levels in transfected cells compared to untransfected cells. Ss and scAAV9-SMN vectors were also produced from these plasmids by transient transfection of HEK293 cells using CaCl2 solution. The silver staining and electron microscopy analysis demonstrated good quality of both isolated vectors, ssAAV9-SMN and scAAV9-SMN, with the titers of 2.00E+13 and 1.00E+13 GC/ml. The results of this study show that, the plasmid containing UTR elements causes to twice more SMN gene expression in transfected cells. The quality control results show that both produced ss and scAAV9-SMN are suitable for in vivo studies. PMID:26607476

  19. Large-Scale Production of Adeno-Associated Viral Vector Serotype-9 Carrying the Human Survival Motor Neuron Gene

    PubMed Central

    RASHNONEJAD, Afrooz; CHERMAHINI, Gholamhossein AMINI; Li, Shaoyong; OZKINAY, Ferda; GAO, Guangping

    2016-01-01

    Recombinant AAV (rAAV) vectors are a suitable vector for gene therapy studies because of desired characteristics such as low immunogenicity, transfection of non-dividing and dividing cells, and long-term expression of the transgene. In this study, the large-scale production of single stranded (ss) and self-complementary (sc) AAV9 carrying the human survival motor neuron (SMN) gene (AAV9-SMN) suitable for in vivo gene therapy studies of SMA was described. SMN cDNA has been cloned into pAAV-CB6-PI and pAAVsc-CB6-PI with and without its specific UTRs, respectively. Both plasmids bear CMV enhancer/beta-actin (CB) promoter, CMV IE enhancer, and polyadenylation signal sequences. 2.5 μg of constructed pAAV-CB6-PI-SMN and pAAVsc-CB6-PI-SMN cause to, respectively, 4.853- and 2.321-fold increases in SMN protein levels in transfected cells compared to untransfected cells. Ss and scAAV9-SMN vectors were also produced from these plasmids by transient transfection of HEK293 cells using CaCl2 solution. The silver staining and electron microscopy analysis demonstrated good quality of both isolated vectors, ssAAV9-SMN and scAAV9- SMN, with the titers of 2.00E+13 and 1.00E+13 GC/ml. The results of this study show that, the plasmid containing UTR elements causes to twice more SMN gene expression in transfected cells. The quality control results show that both produced ss and scAAV9-SMN are suitable for in vivo studies. PMID:26607476

  20. Use of Adeno-Associated and Herpes Simplex Viral Vectors for In Vivo Neuronal Expression in Mice

    PubMed Central

    Penrod, Rachel D.; Wells, Audrey M.; Carlezon, William A.; Cowan, Christopher W.

    2015-01-01

    Adeno-associated viruses and the herpes simplex virus are the two most widely used vectors for the in vivo expression of exogenous genes. Advances in the development of these vectors have enabled remarkable temporal and spatial control of gene expression. This unit provides methods for storing, delivering, and verifying expression of adeno-associated and herpes simplex viruses in the adult mouse brain. It also describes important considerations for experiments using in vivo expression of these viral vectors, including serotype and promoter selection, as well as timing of expression. Additional protocols are provided that describe methods for preliminary experiments to determine the appropriate conditions for in vivo delivery. PMID:26426386

  1. Adeno-Associated Viral Vector-Induced Overexpression of Neuropeptide Y Y2 Receptors in the Hippocampus Suppresses Seizures

    ERIC Educational Resources Information Center

    Woldbye, David P. D.; Angehagen, Mikael; Gotzsche, Casper R.; Elbrond-Bek, Heidi; Sorensen, Andreas T.; Christiansen, Soren H.; Olesen, Mikkel V.; Nikitidou, Litsa; Hansen, Thomas v. O.; Kanter-Schlifke, Irene; Kokaia, Merab

    2010-01-01

    Gene therapy using recombinant adeno-associated viral vectors overexpressing neuropeptide Y in the hippocampus exerts seizure-suppressant effects in rodent epilepsy models and is currently considered for clinical application in patients with intractable mesial temporal lobe epilepsy. Seizure suppression by neuropeptide Y in the hippocampus is…

  2. The Nontoxic Cell Cycle Modulator Indirubin Augments Transduction of Adeno-Associated Viral Vectors and Zinc-Finger Nuclease-Mediated Gene Targeting

    PubMed Central

    Rahman, Shamim H.; Bobis-Wozowicz, Sylwia; Chatterjee, Debanjana; Gellhaus, Katharina; Pars, Kaweh; Heilbronn, Regine; Jacobs, Roland

    2013-01-01

    Abstract Parameters that regulate or affect the cell cycle or the DNA repair choice between non-homologous end-joining and homology-directed repair (HDR) are excellent targets to enhance therapeutic gene targeting. Here, we have evaluated the impact of five cell-cycle modulating drugs on targeted genome engineering mediated by DNA double-strand break (DSB)-inducing nucleases, such as zinc-finger nucleases (ZFNs). For a side-by-side comparison, we have established four reporter cell lines by integrating a mutated EGFP gene into either three transformed human cell lines or primary umbilical cord–derived mesenchymal stromal cells (UC-MSCs). After treatment with different cytostatic drugs, cells were transduced with adeno-associated virus (AAV) vectors that encode a nuclease or a repair donor to rescue EGFP expression through DSB-induced HDR. We show that transient cell-cycle arrest increased AAV transduction and AAV-mediated HDR up to six-fold in human cell lines and ten-fold in UC-MSCs, respectively. Targeted gene correction was observed in up to 34% of transduced cells. Both the absolute and the relative gene-targeting frequencies were dependent on the cell type, the cytostatic drug, the vector dose, and the nuclease. Treatment of cells with the cyclin-dependent kinase inhibitor indirubin-3′-monoxime was especially promising as this compound combined high stimulatory effects with minimal cytotoxicity. In conclusion, indirubin-3′-monoxime significantly improved AAV transduction and the efficiency of AAV/ZFN-mediated gene targeting and may thus represent a promising compound to enhance DSB-mediated genome engineering in human stem cells, such as UC-MSCs, which hold great promise for future clinical applications. PMID:23072634

  3. Preferential Targeting of Disseminated Liver Tumors Using a Recombinant Adeno-Associated Viral Vector

    PubMed Central

    Della Peruta, Marco; Badar, Adam; Rosales, Cecilia; Chokshi, Shilpa; Kia, Azadeh; Nathwani, Devhrut; Galante, Eva; Yan, Ran; Arstad, Erik; Davidoff, Andrew M.; Williams, Roger; Lythgoe, Mark F.

    2015-01-01

    Abstract A novel selectively targeting gene delivery approach has been developed for advanced hepatocellular carcinoma (HCC), a leading cause of cancer mortality whose prognosis remains poor. We combine the strong liver tropism of serotype-8 capsid-pseudotyped adeno-associated viral vectors (AAV8) with a liver-specific promoter (HLP) and microRNA-122a (miR-122a)-mediated posttranscriptional regulation. Systemic administration of our AAV8 construct resulted in preferential transduction of the liver and encouragingly of HCC at heterotopic sites, a finding that could be exploited to target disseminated disease. Tumor selectivity was enhanced by inclusion of miR-122a-binding sequences (ssAAV8-HLP-TK-122aT4) in the expression cassette, resulting in abrogation of transgene expression in normal murine liver but not in HCC. Systemic administration of our tumor-selective vector encoding herpes simplex virus-thymidine kinase (TK) suicide gene resulted in a sevenfold reduction in HCC growth in a syngeneic murine model without toxicity. In summary, we have developed a systemically deliverable gene transfer approach that enables high-level expression of therapeutic genes in HCC but not normal tissues, thus improving the prospects of safe and effective treatment for advanced HCC. PMID:25569358

  4. Analytical Ultracentrifugation as an Approach to Characterize Recombinant Adeno-Associated Viral Vectors.

    PubMed

    Burnham, Brenda; Nass, Shelley; Kong, Elton; Mattingly, MaryEllen; Woodcock, Denise; Song, Antonius; Wadsworth, Samuel; Cheng, Seng H; Scaria, Abraham; O'Riordan, Catherine R

    2015-12-01

    Recombinant adeno-associated viral (rAAV) vectors represent a novel class of biopharmaceutical drugs. The production of clinical-grade rAAV vectors for gene therapy would benefit from analytical methods that are able to monitor drug product quality with regard to homogeneity, purity, and manufacturing consistency. Here, we demonstrate the novel application of analytical ultracentrifugation (AUC) to characterize the homogeneity of preparations of rAAV vectors. We show that a single sedimentation velocity run of rAAV vectors detected and quantified a number of different viral species, such as vectors harboring an intact genome, lacking a vector genome (empty particles), and containing fragmented or incomplete vector genomes. This information is obtained by direct boundary modeling of the AUC data generated from refractometric or UV detection systems using the computer program SEDFIT. Using AUC, we show that multiple parameters contributed to vector quality, including the AAV genome form (i.e., self-complementary vs. single-stranded), vector genome size, and the production and purification methods. Hence, AUC is a critical tool for identifying optimal production and purification processes and for monitoring the physical attributes of rAAV vectors to ensure their quality. PMID:26414997

  5. Adeno associated viral-mediated intraosseous labeling of bone marrow derived cells for CNS tracking.

    PubMed

    Selenica, Maj-Linda B; Reid, Patrick; Pena, Gabriela; Alvarez, Jennifer; Hunt, Jerry B; Nash, Kevin R; Morgan, Dave; Gordon, Marcia N; Lee, Daniel C

    2016-05-01

    Inflammation, including microglial activation in the CNS, is an important hallmark in many neurodegenerative diseases. Microglial stimuli not only impact the brain microenvironment by production and release of cytokines and chemokines, but also influence the activity of bone marrow derived cells and blood born macrophage populations. In many diseases including brain disorders and spinal cord injury, researchers have tried to harbor the neuroprotective and repair properties of these subpopulations. Hematopoietic bone marrow derived cells (BMDCs) are of great interest, especially during gene therapy because certain hematopoietic cell subpopulations traffic to the sites of injury and inflammation. The aim of this study was to develop a method of labeling endogenous bone marrow derived cells through intraosseous impregnation of recombinant adeno-associated virus (rAAV) or lentivirus. We utilized rAAV serotype 9 (rAAV-9) or lentivirus for gene delivery of green florescence protein (GFP) to the mouse bone marrow cells. Flow cytometry showed that both viruses were able to efficiently transduce mouse bone marrow cells in vivo. However, the rAAV9-GFP viral construct transduced BMDCs more efficiently than the lentivirus (11.2% vs. 6.8%), as indicated by cellular GFP expression. We also demonstrate that GFP labeled cells correspond to bone marrow cells of myeloid origin using CD11b as a marker. Additionally, we characterized the ability of bone marrow derived, GFP labeled cells to extravasate into the brain parenchyma upon acute and subchronic neuroinflammatory stimuli in the mouse CNS. Viral mediated over expression of chemokine (C-C motif) ligand 2 (CCL2) or intracranial injection of lipopolysaccharide (LPS) recruited GFP labeled BMDCs from the periphery into the brain parenchyma compared to vehicle treated mice. Altogether our findings demonstrate a useful method of labeling endogenous BMDCs via viral transduction and the ability to track subpopulations throughout the body

  6. Adeno-Associated Viral-Mediated Catalase Expression Suppresses Optic Neuritis in Experimental Allergic Encephalomyelitis

    NASA Astrophysics Data System (ADS)

    Guy, John; Qi, Xiaoping; Hauswirth, William W.

    1998-11-01

    Suppression of oxidative injury by viral-mediated transfer of the human catalase gene was tested in the optic nerves of animals with experimental allergic encephalomyelitis (EAE). EAE is an inflammatory autoimmune disorder of primary central nervous system demyelination that has been frequently used as an animal model for the human disease multiple sclerosis (MS). The optic nerve is a frequent site of involvement common to both EAE and MS. Recombinant adeno-associated virus containing the human gene for catalase was injected over the right optic nerve heads of SJL/J mice that were simultaneously sensitized for EAE. After 1 month, cell-specific catalase activity, evaluated by quantitation of catalase immunogold, was increased approximately 2-fold each in endothelia, oligodendroglia, astrocytes, and axons of the optic nerve. Effects of catalase on the histologic lesions of EAE were measured by computerized analysis of the myelin sheath area (for demyelination), optic disc area (for optic nerve head swelling), extent of the cellular infiltrate, extravasated serum albumin labeled by immunogold (for blood-brain barrier disruption), and in vivo H2O2 reaction product. Relative to control, contralateral optic nerves injected with the recombinant virus without a therapeutic gene, catalase gene inoculation reduced demyelination by 38%, optic nerve head swelling by 29%, cellular infiltration by 34%, disruption of the blood-brain barrier by 64%, and in vivo levels of H2O2 by 61%. Because the efficacy of potential treatments for MS are usually initially tested in the EAE animal model, this study suggests that catalase gene delivery by using viral vectors may be a therapeutic strategy for suppression of MS.

  7. Enhancing gene delivery of adeno-associated viruses by cell-permeable peptides

    PubMed Central

    Liu, Yarong; Kim, Young Joo; Ji, Man; Fang, Jinxu; Siriwon, Natnaree; Zhang, Li I; Wang, Pin

    2014-01-01

    Adeno-associated virus type 2 (AAV2) is considered a promising gene delivery vector and has been extensively applied in several disease models; however, inefficient transduction in various cells and tissues has limited its widespread application in many areas of gene therapy. In this study, we have developed a general, but efficient, strategy to enhance viral transduction, both in vitro and in vivo, by incubating viral particles with cell-permeable peptides (CPPs). We show that CPPs increase internalization of viral particles into cells by facilitating both energy-independent and energy-dependent endocytosis. Moreover, CPPs can significantly enhance the endosomal escape process of viral particles, thus enhancing viral transduction to those cells that have exhibited very low permissiveness to AAV2 infection as a result of impaired intracellular viral processing. We also demonstrated that this approach could be applicable to other AAV serotypes. Thus, the membrane-penetrating ability of CPPs enables us to generate an efficient method for enhanced gene delivery of AAV vectors, potentially facilitating its applicability to human gene therapy. PMID:26015948

  8. Adeno-Associated Viral Vectors for Mapping, Monitoring, and Manipulating Neural Circuits

    PubMed Central

    Betley, J. Nicholas

    2011-01-01

    Abstract Understanding the structure and function of neural circuits is central is neuroscience research. To address the associated questions, new genetically encoded tools have been developed for mapping, monitoring, and manipulating neurons. Essential to implementation of these tools is their selective delivery to defined neuronal populations in the brain. This has been facilitated by recent improvements in cell type–specific transgene expression using recombinant adeno-associated viral vectors. Here, we highlight these developments and discuss areas for improvement that could further expand capabilities for neural circuit analysis. PMID:21319997

  9. Adeno-associated virus (AAV) gene delivery in stem cell therapy.

    PubMed

    Brown, Nolan J; Hirsch, Matthew L

    2015-11-01

    The past 30 years have witnessed the development of cell and gene therapies for the treatment of diverse human diseases. Each of these approaches has inherent advantages and disadvantages; however, the two methods align in that, essentially, they are both methods of foreign DNA delivery to complement, eradicate, or supplement nucleotide sequences important for human health. As discussed herein, the combination of these therapies (gene therapy in stem cells), particularly in an ex vivo context, offers powerful genetic engineering which is applicable to the treatment of both genetic and acquired maladies ranging from blood diseases to the treatment of HIV infection. Of the existing gene therapy approaches, including non-viral and viral vectors, those based on adeno-associated virus (AAV) are currently at the forefront as they have been safely used in hundreds of clinical trials and have demonstrated remarkable success in treating blindness and hemophilia B. However, AAV vectors used in combination with cell-based therapies have not transitioned to the clinic. Instead, adenoviral, retroviral, and lentiviral vectors are the preferred choice for the modification of stem cells prior to patient infusion. This review provides a general background of AAV gene therapy and cell therapies, and highlights reports demonstrating apparently conflicting data of productive transduction and vector-induced toxicity using recombinant AAV in stem and stem-like cells. PMID:26645905

  10. Neutralizing Antibodies Against Adeno-Associated Viral Capsids in Patients with mut Methylmalonic Acidemia.

    PubMed

    Harrington, Elizabeth A; Sloan, Jennifer L; Manoli, Irini; Chandler, Randy J; Schneider, Mark; McGuire, Peter J; Calcedo, Roberto; Wilson, James M; Venditti, Charles P

    2016-05-01

    Isolated methylmalonic acidemia (MMA), a group of autosomal recessive inborn errors of metabolism, is most commonly caused by complete (mut(0)) or partial (mut(-)) deficiency of the enzyme methylmalonyl-CoA mutase (MUT). The severe metabolic instability and increased mortality experienced by many affected individuals, especially those with mut(0) MMA, has led centers to use elective liver transplantation as a treatment for these patients. We have previously demonstrated the efficacy of systemic adeno-associated viral (AAV) gene delivery as a treatment for MMA in a murine model and therefore sought to survey AAV antibody titers against serotypes 2, 8, and 9 in a group of well-characterized MMA patients, accrued via a dedicated natural history study ( clinicaltrials.gov ID: NCT00078078). Plasma samples provided by 42 patients (8 mut(-) and 34 mut(0); 10 had received organ transplantation), who ranged in age between 2 and 31 years, were analyzed to examine AAV2 (n = 35), AAV8 (n = 41), and AAV9 (n = 42) antibody titers. In total, the seroprevalence of antibodies against AAV2, AAV8, or AAV9 was 20%, 22%, and 24%, respectively. We observed a lower-than-expected seropositivity rate (titers ≥1:20) in the pediatric MMA patients (2-18 years) for both AAV2 (p < 0.05) and AAV8 (p < 0.01) neutralizing antibodies (NAbs) compared with historical controls. Those with positive NAb titers were typically older than 18 years (p < 0.05 all serotypes) or had received solid organ transplantation (p < 0.01 AAV8, AAV9). The mut(0) patients who had not been transplanted (n = 24)-that is, the subset with the greatest need for improved treatments-represented the seronegative majority, with 21 out of 24 patients lacking Abs against all AAV capsids tested. The unexpected lack of NAbs against AAV in this patient population has encouraging implications for systemic gene delivery as a treatment for mut MMA. PMID:26790480

  11. Perspective on Adeno-Associated Virus Capsid Modification for Duchenne Muscular Dystrophy Gene Therapy.

    PubMed

    Nance, Michael E; Duan, Dongsheng

    2015-12-01

    Duchenne muscular dystrophy (DMD) is a X-linked, progressive childhood myopathy caused by mutations in the dystrophin gene, one of the largest genes in the genome. It is characterized by skeletal and cardiac muscle degeneration and dysfunction leading to cardiac and/or respiratory failure. Adeno-associated virus (AAV) is a highly promising gene therapy vector. AAV gene therapy has resulted in unprecedented clinical success for treating several inherited diseases. However, AAV gene therapy for DMD remains a significant challenge. Hurdles for AAV-mediated DMD gene therapy include the difficulty to package the full-length dystrophin coding sequence in an AAV vector, the necessity for whole-body gene delivery, the immune response to dystrophin and AAV capsid, and the species-specific barriers to translate from animal models to human patients. Capsid engineering aims at improving viral vector properties by rational design and/or forced evolution. In this review, we discuss how to use the state-of-the-art AAV capsid engineering technologies to overcome hurdles in AAV-based DMD gene therapy. PMID:26414293

  12. Germline viral “fossils” guide in silico reconstruction of a mid-Cenozoic era marsupial adeno-associated virus

    PubMed Central

    Smith, Richard H.; Hallwirth, Claus V.; Westerman, Michael; Hetherington, Nicola A.; Tseng, Yu-Shan; Cecchini, Sylvain; Virag, Tamas; Ziegler, Mona-Larissa; Rogozin, Igor B.; Koonin, Eugene V.; Agbandje-McKenna, Mavis; Kotin, Robert M.; Alexander, Ian E.

    2016-01-01

    Germline endogenous viral elements (EVEs) genetically preserve viral nucleotide sequences useful to the study of viral evolution, gene mutation, and the phylogenetic relationships among host organisms. Here, we describe a lineage-specific, adeno-associated virus (AAV)-derived endogenous viral element (mAAV-EVE1) found within the germline of numerous closely related marsupial species. Molecular screening of a marsupial DNA panel indicated that mAAV-EVE1 occurs specifically within the marsupial suborder Macropodiformes (present-day kangaroos, wallabies, and related macropodoids), to the exclusion of other Diprotodontian lineages. Orthologous mAAV-EVE1 locus sequences from sixteen macropodoid species, representing a speciation history spanning an estimated 30 million years, facilitated compilation of an inferred ancestral sequence that recapitulates the genome of an ancient marsupial AAV that circulated among Australian metatherian fauna sometime during the late Eocene to early Oligocene. In silico gene reconstruction and molecular modelling indicate remarkable conservation of viral structure over a geologic timescale. Characterisation of AAV-EVE loci among disparate species affords insight into AAV evolution and, in the case of macropodoid species, may offer an additional genetic basis for assignment of phylogenetic relationships among the Macropodoidea. From an applied perspective, the identified AAV “fossils” provide novel capsid sequences for use in translational research and clinical applications. PMID:27377618

  13. Germline viral "fossils" guide in silico reconstruction of a mid-Cenozoic era marsupial adeno-associated virus.

    PubMed

    Smith, Richard H; Hallwirth, Claus V; Westerman, Michael; Hetherington, Nicola A; Tseng, Yu-Shan; Cecchini, Sylvain; Virag, Tamas; Ziegler, Mona-Larissa; Rogozin, Igor B; Koonin, Eugene V; Agbandje-McKenna, Mavis; Kotin, Robert M; Alexander, Ian E

    2016-01-01

    Germline endogenous viral elements (EVEs) genetically preserve viral nucleotide sequences useful to the study of viral evolution, gene mutation, and the phylogenetic relationships among host organisms. Here, we describe a lineage-specific, adeno-associated virus (AAV)-derived endogenous viral element (mAAV-EVE1) found within the germline of numerous closely related marsupial species. Molecular screening of a marsupial DNA panel indicated that mAAV-EVE1 occurs specifically within the marsupial suborder Macropodiformes (present-day kangaroos, wallabies, and related macropodoids), to the exclusion of other Diprotodontian lineages. Orthologous mAAV-EVE1 locus sequences from sixteen macropodoid species, representing a speciation history spanning an estimated 30 million years, facilitated compilation of an inferred ancestral sequence that recapitulates the genome of an ancient marsupial AAV that circulated among Australian metatherian fauna sometime during the late Eocene to early Oligocene. In silico gene reconstruction and molecular modelling indicate remarkable conservation of viral structure over a geologic timescale. Characterisation of AAV-EVE loci among disparate species affords insight into AAV evolution and, in the case of macropodoid species, may offer an additional genetic basis for assignment of phylogenetic relationships among the Macropodoidea. From an applied perspective, the identified AAV "fossils" provide novel capsid sequences for use in translational research and clinical applications. PMID:27377618

  14. Directed evolution of novel adeno-associated viruses for therapeutic gene delivery.

    PubMed

    Bartel, M A; Weinstein, J R; Schaffer, D V

    2012-06-01

    Gene therapy vectors based on adeno-associated virus (AAV) are currently in clinical trials for numerous disease targets, such as muscular dystrophy, hemophilia, Parkinson's disease, Leber's congenital amaurosis and macular degeneration. Despite its considerable promise and emerging clinical success, several challenges impede the broader implementation of AAV gene therapy, including the prevalence of neutralizing antibodies in the human population, low transduction of a number of therapeutically relevant cell and tissue types, an inability to overcome physical and cellular barriers in vivo and a relatively limited carrying capacity. These challenges arise as the demands we place on AAV vectors are often different from or even at odds with the properties nature bestowed on their parent viruses. Viral-directed evolution-the iterative generation of large, diverse libraries of viral mutants and selection for variants with specific properties of interest-offers an approach to address these problems. Here we outline progress in creating novel classes of AAV variant libraries and highlight the successful isolation of variants with novel and advantageous in vitro and in vivo gene delivery properties. PMID:22402323

  15. Manufacturing of recombinant adeno-associated viral vectors for clinical trials

    PubMed Central

    Clément, Nathalie; Grieger, Joshua C

    2016-01-01

    The ability to elicit robust and long-term transgene expression in vivo together with minimal immunogenicity and little to no toxicity are only a few features that make recombinant adeno-associated virus (rAAV) vectors ideally suited for many gene therapy applications. Successful preclinical studies have encouraged the use of rAAV for therapeutic gene transfer to patients in the clinical setting. Nevertheless, the use of rAAV in clinical trials has underscored the need for production and purification systems capable of generating large amounts of highly pure rAAV particles. To date, generating vector quantities sufficient to meet the expanding clinical demand is still a hurdle when using current production systems. In this chapter, we will provide a description of the current methods to produce clinical grade of rAAV under current good manufacturing practice (cGMP) settings. PMID:27014711

  16. Chemical Modulation of Endocytic Sorting Augments Adeno-associated Viral Transduction.

    PubMed

    Berry, Garrett E; Asokan, Aravind

    2016-01-01

    Intracellular trafficking of viruses can be influenced by a variety of inter-connected cellular sorting and degradation pathways involving endo-lysosomal vesicles, the ubiquitin-proteasome system, and autophagy-based or endoplasmic reticulum-associated machinery. In the case of recombinant adeno-associated viruses (AAV), proteasome inhibitors are known to prevent degradation of ubiquitinated AAV capsids, thereby leading to increased nuclear accumulation and transduction. However, the impact of other cellular degradation pathways on AAV trafficking is not well understood. In the current study, we screened a panel of small molecules focused on modulating different cellular degradation pathways and identified eeyarestatin I (EerI) as a novel reagent that enhances AAV transduction. EerI improved AAV transduction by an order of magnitude regardless of vector dose, genome architecture, cell type, or serotype. This effect was preceded by sequestration of AAV within enlarged vesicles that were dispersed throughout the cytoplasm. Specifically, EerI treatment redirected AAV particles toward large vesicles positive for late endosomal (Rab7) and lysosomal (LAMP1) markers. Notably, MG132 and EerI (proteasomal and endoplasmic reticulum-associated degradation inhibitors, respectively) appear to enhance AAV transduction by increasing the intracellular accumulation of viral particles in a mutually exclusive fashion. Taken together, our results expand on potential strategies to redirect recombinant AAV vectors toward more productive trafficking pathways by deregulating cellular degradation mechanisms. PMID:26527686

  17. CRISPR/Cas9-mediated genome engineering: an adeno-associated viral (AAV) vector toolbox.

    PubMed

    Senís, Elena; Fatouros, Chronis; Große, Stefanie; Wiedtke, Ellen; Niopek, Dominik; Mueller, Ann-Kristin; Börner, Kathleen; Grimm, Dirk

    2014-11-01

    Its remarkable ease and efficiency make the CRISPR (clustered regularly interspaced short palindromic repeats) DNA editing machinery highly attractive as a new tool for experimental gene annotation and therapeutic genome engineering in eukaryotes. Here, we report a versatile set of plasmids and vectors derived from adeno-associated virus (AAV) that allow robust and specific delivery of the two essential CRISPR components - Cas9 and chimeric g(uide)RNA - either alone or in combination. All our constructs share a modular design that enables simple and stringent guide RNA (gRNA) cloning as well as rapid exchange of promoters driving Cas9 or gRNA. Packaging into potent synthetic AAV capsids permits CRISPR delivery even into hard-to-transfect targets, as shown for human T-cells. Moreover, we demonstrate the feasibility to direct Cas9 expression to or away from hepatocytes, using a liver-specific promoter or a hepatic miRNA binding site, respectively. We also report a streamlined and economical protocol for detection of CRISPR-induced mutations in less than 3 h. Finally, we provide original evidence that AAV/CRISPR vectors can be exploited for gene engineering in vivo, as exemplified in the liver of adult mice. Our new tools and protocols should foster the broad application of CRISPR technology in eukaryotic cells and organisms, and accelerate its clinical translation into humans. PMID:25186301

  18. Large-scale adeno-associated viral vector production using a herpesvirus-based system enables manufacturing for clinical studies.

    PubMed

    Clément, Nathalie; Knop, David R; Byrne, Barry J

    2009-08-01

    The ability of recombinant adeno-associated viral (rAAV) vectors to exhibit minimal immunogenicity and little to no toxicity or inflammation while eliciting robust, multiyear gene expression in vivo are only a few of the salient features that make them ideally suited for many gene therapy applications. A major hurdle for the use of rAAV in sizeable research and clinical applications is the lack of efficient and versatile large-scale production systems. Continued progression toward flexible, scalable production techniques is a prerequisite to support human clinical evaluation of these novel biotherapeutics. This review examines the current state of large-scale production methods that employ the herpes simplex virus type 1 (HSV) platform to produce rAAV vectors for gene delivery. Improvements have substantially advanced the HSV/AAV hybrid method for large-scale rAAV manufacture, facilitating the generation of highly potent, clinical-grade purity rAAV vector stocks. At least one human clinical trial employing rAAV generated via rHSV helper-assisted replication is poised to commence, highlighting the advances and relevance of this production method. PMID:19569968

  19. Noninvasive Imaging Reveals Stable Transgene Expression in Mouse Airways After Delivery of a Nonintegrating Recombinant Adeno-Associated Viral Vector.

    PubMed

    Vidović, Dragana; Gijsbers, Rik; Jimenez, Ana Quiles; Dooley, James; Van den Haute, Chris; Van der Perren, Anke; Liston, Adrian; Baekelandt, Veerle; Debyser, Zeger; Carlon, Marianne Sylvia

    2016-01-01

    Gene therapy holds promise to cure a wide range of genetic and acquired diseases. Recent successes in recombinant adeno-associated viral vector (rAAV)-based gene therapy in the clinic for hereditary disorders such as Leber's congenital amaurosis and hemophilia B encouraged us to reexplore an rAAV approach for pulmonary gene transfer. Only limited clinical successes have been achieved for airway gene transfer so far, underscoring the need for further preclinical development of rAAV-based gene therapy for pulmonary disorders. We sought to determine the preclinical potential of an airway-tropic serotype, rAAV2/5, encoding reporter genes when delivered to mouse airways. Although several groups have assessed the stability of gene transfer using a nonintegrating rAAV in mouse airways, long-term stability for more than a year has not been reported. Additionally, an extensive quantitative analysis of the specific cell types targeted by rAAV2/5 using cell-specific markers is lacking. We obtained sustained gene expression in upper and lower airways up to 15 months after vector administration, a substantial proportion of the lifespan of a laboratory mouse. In addition, we demonstrated that readministration of rAAV2/5 to the airways is feasible and increases gene expression 14 months after primary vector administration, despite the presence of circulating neutralizing antibodies. Finally, identification of transduced cell types revealed different subpopulations being targeted by rAAV2/5, with 64% of β-galactosidase-positive cells being ciliated cells, 34% club cells in the conducting airways, and 75% alveolar type II cells in the alveoli at 1 month postinjection. This underscores the therapeutic potential of a nonintegrating rAAV vector to develop a gene therapeutic drug for a variety of pulmonary disorders, such as cystic fibrosis, primary ciliary dyskinesia, and surfactant deficiencies. PMID:26567984

  20. In vivo adeno-associated viral vector-mediated genetic engineering of white and brown adipose tissue in adult mice.

    PubMed

    Jimenez, Veronica; Muñoz, Sergio; Casana, Estefania; Mallol, Cristina; Elias, Ivet; Jambrina, Claudia; Ribera, Albert; Ferre, Tura; Franckhauser, Sylvie; Bosch, Fatima

    2013-12-01

    Adipose tissue is pivotal in the regulation of energy homeostasis through the balance of energy storage and expenditure and as an endocrine organ. An inadequate mass and/or alterations in the metabolic and endocrine functions of adipose tissue underlie the development of obesity, insulin resistance, and type 2 diabetes. To fully understand the metabolic and molecular mechanism(s) involved in adipose dysfunction, in vivo genetic modification of adipocytes holds great potential. Here, we demonstrate that adeno-associated viral (AAV) vectors, especially serotypes 8 and 9, mediated efficient transduction of white (WAT) and brown adipose tissue (BAT) in adult lean and obese diabetic mice. The use of short versions of the adipocyte protein 2 or uncoupling protein-1 promoters or micro-RNA target sequences enabled highly specific, long-term AAV-mediated transgene expression in white or brown adipocytes. As proof of concept, delivery of AAV vectors encoding for hexokinase or vascular endothelial growth factor to WAT or BAT resulted in increased glucose uptake or increased vessel density in targeted depots. This method of gene transfer also enabled the secretion of stable high levels of the alkaline phosphatase marker protein into the bloodstream by transduced WAT. Therefore, AAV-mediated genetic engineering of adipose tissue represents a useful tool for the study of adipose pathophysiology and, likely, for the future development of new therapeutic strategies for obesity and diabetes. PMID:24043756

  1. In Vivo Adeno-Associated Viral Vector–Mediated Genetic Engineering of White and Brown Adipose Tissue in Adult Mice

    PubMed Central

    Jimenez, Veronica; Muñoz, Sergio; Casana, Estefania; Mallol, Cristina; Elias, Ivet; Jambrina, Claudia; Ribera, Albert; Ferre, Tura; Franckhauser, Sylvie; Bosch, Fatima

    2013-01-01

    Adipose tissue is pivotal in the regulation of energy homeostasis through the balance of energy storage and expenditure and as an endocrine organ. An inadequate mass and/or alterations in the metabolic and endocrine functions of adipose tissue underlie the development of obesity, insulin resistance, and type 2 diabetes. To fully understand the metabolic and molecular mechanism(s) involved in adipose dysfunction, in vivo genetic modification of adipocytes holds great potential. Here, we demonstrate that adeno-associated viral (AAV) vectors, especially serotypes 8 and 9, mediated efficient transduction of white (WAT) and brown adipose tissue (BAT) in adult lean and obese diabetic mice. The use of short versions of the adipocyte protein 2 or uncoupling protein-1 promoters or micro-RNA target sequences enabled highly specific, long-term AAV-mediated transgene expression in white or brown adipocytes. As proof of concept, delivery of AAV vectors encoding for hexokinase or vascular endothelial growth factor to WAT or BAT resulted in increased glucose uptake or increased vessel density in targeted depots. This method of gene transfer also enabled the secretion of stable high levels of the alkaline phosphatase marker protein into the bloodstream by transduced WAT. Therefore, AAV-mediated genetic engineering of adipose tissue represents a useful tool for the study of adipose pathophysiology and, likely, for the future development of new therapeutic strategies for obesity and diabetes. PMID:24043756

  2. Adeno-Associated Virus-Based Gene Therapy for CNS Diseases

    PubMed Central

    Hocquemiller, Michaël; Giersch, Laura; Audrain, Mickael; Parker, Samantha; Cartier, Nathalie

    2016-01-01

    Gene therapy is at the cusp of a revolution for treating a large spectrum of CNS disorders by providing a durable therapeutic protein via a single administration. Adeno-associated virus (AAV)-mediated gene transfer is of particular interest as a therapeutic tool because of its safety profile and efficiency in transducing a wide range of cell types. The purpose of this review is to describe the most notable advancements in preclinical and clinical research on AAV-based CNS gene therapy and to discuss prospects for future development based on a new generation of vectors and delivery. PMID:27267688

  3. The state of the art of adeno-associated virus-based vectors in gene therapy

    PubMed Central

    Coura, Renata dos Santos; Nardi, Nance Beyer

    2007-01-01

    The adeno-associated virus (AAV) has rapidly gained popularity in gene therapy since the establishment of the first AAV2 infectious clone, in 1982, due to some of their distinguishing characteristics such as lack of pathogenicity, wide range of infectivity, and ability to establish long-term transgene expression. Notably over the past decade, this virus has attracted considerable interest as a gene therapy vector, and about 85% of the currently available 2,041 PubMed references on adeno-associated viruses have been published during this time. The exponential progress of AAV-based vectors has been made possible by the advances in the knowledge of the virology and biology of this virus, which allows great improvement in AAV vectors construction and a better comprehension of their operation. Moreover, with the recent discovery of novel AAV serotypes, there is virtually one preferred serotype for nearly every organ or tissue to target. Thus, AAV-based vectors have been successfully overcoming the main gene therapy challenges such as transgene maintenance, safety and host immune response, and meeting the desirable vector system features of high level of safety combined with clinical efficacy and versatility in terms of potential applications. Consequently, AAV is increasingly becoming the vector of choice for a wide range of gene therapy approaches. This report will highlight the state of the art of AAV-based vectors studies and the advances on the use of AAV vectors for several gene therapy approaches. PMID:17939872

  4. Adeno-Associated Viral Vector-Mediated Transgene Expression Is Independent of DNA Methylation in Primate Liver and Skeletal Muscle

    PubMed Central

    Léger, Adrien; Le Guiner, Caroline; Nickerson, Michael L.; McGee Im, Kate; Ferry, Nicolas; Moullier, Philippe; Snyder, Richard O.; Penaud-Budloo, Magalie

    2011-01-01

    Recombinant adeno-associated viral (rAAV) vectors can support long-term transgene expression in quiescent tissues. Intramuscular (IM) administration of a single-stranded AAV vector (ssAAV) in the nonhuman primate (NHP) results in a peak protein level at 2–3 months, followed by a decrease over several months before reaching a steady-state. To investigate transgene expression and vector genome persistence, we previously demonstrated that rAAV vector genomes associate with histones and form a chromatin structure in NHP skeletal muscle more than one year after injection. In the mammalian nucleus, chromatin remodeling via epigenetic modifications plays key role in transcriptional regulation. Among those, CpG hyper-methylation of promoters is a known hallmark of gene silencing. To assess the involvement of DNA methylation on the transgene expression, we injected NHP via the IM or the intravenous (IV) route with a recombinant ssAAV2/1 vector. The expression cassette contains the transgene under the transcriptional control of the constitutive Rous Sarcoma Virus promoter (RSVp). Total DNA isolated from NHP muscle and liver biopsies from 1 to 37 months post-injection was treated with sodium bisulfite and subsequently analyzed by pyrosequencing. No significant CpG methylation of the RSVp was found in rAAV virions or in vector DNA isolated from NHP transduced tissues. Direct de novo DNA methylation appears not to be involved in repressing transgene expression in NHP after gene transfer mediated by ssAAV vectors. The study presented here examines host/vector interactions and the impact on transgene expression in a clinically relevant model. PMID:21687632

  5. Highly Efficient Delivery of Adeno-Associated Viral Vectors to the Primate Retina.

    PubMed

    Boye, Shannon E; Alexander, John J; Witherspoon, C Douglas; Boye, Sanford L; Peterson, James J; Clark, Mark E; Sandefer, Kristen J; Girkin, Chris A; Hauswirth, William W; Gamlin, Paul D

    2016-08-01

    Adeno-associated virus (AAV) has emerged as the preferred vector for targeting gene expression to the retina. Subretinally injected AAV can efficiently transduce retinal pigment epithelium and photoreceptors in primate retina. Inner and middle primate retina can be transduced by intravitreally delivered AAV, but with low efficiency. This is due to dilution of vector, potential neutralization of capsid because it is not confined to the immune-privileged retinal compartment, and the presence of the inner limiting membrane (ILM), a barrier separating the vitreous from the neural retina. We here describe a novel "subILM" injection method that addresses all three issues. Specifically, vector is placed in a surgically induced, hydrodissected space between the ILM and neural retina. In an initial experiment, we injected viscoelastic (Healon(®)), a substance we confirmed was biocompatible with AAV, to create a subILM bleb and subsequently injected AAV2-GFP into the bleb after irrigation with basic salt solution. For later experiments, we used a Healon-AAV mixture to place single, subILM injections. In all cases, subILM delivery of AAV was well tolerated-no inflammation or gross structural changes were observed by ophthalmological examination or optical coherence tomography. In-life fluorescence imaging revealed profound transgene expression within the area of the subILM injection bleb that persisted for the study duration. Uniform and extensive transduction of retinal ganglion cells (RGCs) was achieved in the areas beneath the subILM bleb. Transduction of Müller glia, ON bipolar cells, and photoreceptors was also observed. Robust central labeling from green fluorescent protein-expressing RGCs confirmed their continued survival, and was observed in the lateral geniculate nucleus, the superior colliculus, and the pretectum. Our results confirm that the ILM is a major barrier to transduction by AAV in primate retina and that, when it is circumvented, the efficiency and

  6. Inducible long-term gene expression in brain with adeno-associated virus gene transfer.

    PubMed

    Haberman, R P; McCown, T J; Samulski, R J

    1998-12-01

    Recombinant adeno-associated virus (rAAV) vectors hold promise for treating a number of neurological disorders due to the ability to deliver long-term gene expression without toxicity or immune response. Critical to these endeavors will be controlled expression of the therapeutic gene in target cells. We have constructed and tested a dual cassette rAAV vector carrying a reporter gene under the control of the tetracycline-responsive system and the tetracycline transactivator. Transduction in vitro resulted in stable expression from the vector that can be suppressed 20-fold by tetracycline treatment. In vivo experiments, carried out to 6 weeks, demonstrated that vector-transduced expression is sustained until doxycycline administration upon which reporter gene expression is reduced. Moreover, the suppression of vector-driven expression can be reversed by removal of the drug. These studies demonstrate long-term regulated gene expression from rAAV vectors. This system will provide a valuable approach for controlling vector gene expression both in vitro and in vivo. PMID:10023439

  7. Recombinant adeno-associated virus targets passenger gene expression to cones in primate retina

    NASA Astrophysics Data System (ADS)

    Mancuso, Katherine; Hendrickson, Anita E.; Connor, Thomas B., Jr.; Mauck, Matthew C.; Kinsella, James J.; Hauswirth, William W.; Neitz, Jay; Neitz, Maureen

    2007-05-01

    Recombinant adeno-associated virus (rAAV) is a promising vector for gene therapy of photoreceptor-based diseases. Previous studies have demonstrated that rAAV serotypes 2 and 5 can transduce both rod and cone photoreceptors in rodents and dogs, and it can target rods, but not cones in primates. Here we report that using a human cone-specific enhancer and promoter to regulate expression of a green fluorescent protein (GFP) reporter gene in an rAAV-5 vector successfully targeted expression of the reporter gene to primate cones, and the time course of GFP expression was able to be monitored in a living animal using the RetCam II digital imaging system.

  8. Adeno-associated virus vectors: potential applications for cancer gene therapy

    PubMed Central

    Li, Chengwen; Bowles, Dawn E; van Dyke, Terry; Samulski, Richard Jude

    2006-01-01

    Augmenting cancer treatment by protein and gene delivery continues to gain momentum based on success in animal models. The primary hurdle of fully exploiting the arsenal of molecular targets and therapeutic transgenes continues to be efficient delivery. Vectors based on adeno-associated virus (AAV) are of particular interest as they are capable of inducing transgene expression in a broad range of tissues for a relatively long time without stimulation of a cell-mediated immune response. Perhaps the most important attribute of AAV vectors is their safety profile in phase I clinical trials ranging from CF to Parkinson’s disease. The utility of AAV vectors as a gene delivery agent in cancer therapy is showing promise in preclinical studies. In this review, we will focus on the basic biology of AAV as well as recent progress in the use of this vector in cancer gene therapy. PMID:15962012

  9. Targeting adeno-associated virus and adenoviral gene therapy for hepatocellular carcinoma.

    PubMed

    Wang, Yi-Gang; Huang, Pan-Pan; Zhang, Rong; Ma, Bu-Yun; Zhou, Xiu-Mei; Sun, Yan-Fang

    2016-01-01

    Human hepatocellular carcinoma (HCC) heavily endangers human heath worldwide. HCC is one of most frequent cancers in China because patients with liver disease, such as chronic hepatitis, have the highest cancer susceptibility. Traditional therapeutic approaches have limited efficacy in advanced liver cancer, and novel strategies are urgently needed to improve the limited treatment options for HCC. This review summarizes the basic knowledge, current advances, and future challenges and prospects of adeno-associated virus (AAV) and adenoviruses as vectors for gene therapy of HCC. This paper also reviews the clinical trials of gene therapy using adenovirus vectors, immunotherapy, toxicity and immunological barriers for AAV and adenoviruses, and proposes several alternative strategies to overcome the therapeutic barriers to using AAV and adenoviruses as vectors. PMID:26755879

  10. Targeting adeno-associated virus and adenoviral gene therapy for hepatocellular carcinoma

    PubMed Central

    Wang, Yi-Gang; Huang, Pan-Pan; Zhang, Rong; Ma, Bu-Yun; Zhou, Xiu-Mei; Sun, Yan-Fang

    2016-01-01

    Human hepatocellular carcinoma (HCC) heavily endangers human heath worldwide. HCC is one of most frequent cancers in China because patients with liver disease, such as chronic hepatitis, have the highest cancer susceptibility. Traditional therapeutic approaches have limited efficacy in advanced liver cancer, and novel strategies are urgently needed to improve the limited treatment options for HCC. This review summarizes the basic knowledge, current advances, and future challenges and prospects of adeno-associated virus (AAV) and adenoviruses as vectors for gene therapy of HCC. This paper also reviews the clinical trials of gene therapy using adenovirus vectors, immunotherapy, toxicity and immunological barriers for AAV and adenoviruses, and proposes several alternative strategies to overcome the therapeutic barriers to using AAV and adenoviruses as vectors. PMID:26755879

  11. A Hypoxia-Regulated Adeno-Associated Virus Vector for Cancer-Specific Gene Therapy1

    PubMed Central

    Ruan, Hangjun; Su, Hua; Hu, Lily; Lamborn, Kathleen R; Kan, YW; Deen, Dennis F

    2001-01-01

    Abstract The presence of hypoxic cells in human brain tumors is an important factor leading to resistance to radiation therapy. However, this physiological difference between normal tissues and tumors also provides the potential for designing cancer-specific gene therapy. We compared the increase of gene expression under anoxia (<0.01% oxygen) produced by 3, 6, and 9 copies of hypoxia-responsive elements (HRE) from the erythropoietin gene (Epo), which are activated through the transcriptional complex hypoxia-inducible factor 1 (HIF-1). Under anoxic conditions, nine copies of HRE (9XHRE) yielded 27- to 37-fold of increased gene expression in U-251 MG and U-87 MG human brain tumor cell lines. Under the less hypoxic conditions of 0.3% and 1% oxygen, gene activation by 9XHRE increased expression 11- to 18-fold in these cell lines. To generate a recombinant adeno-associated virus (rAAV) in which the transgene can be regulated by hypoxia, we inserted the DNA fragment containing 9XHRE and the LacZ reporter gene into an AAV vector. Under anoxic conditions, this vector produced 79- to 110-fold increase in gene expression. We believe this hypoxia-regulated rAAV vector will provide a useful delivery vehicle for cancer-specific gene therapy. PMID:11494119

  12. Gene transfer in the liver using recombinant adeno-associated virus

    PubMed Central

    Ahmed, Seemin Seher; Li, Jia; Godwin, Jonathan; Gao, Guangping; Zhong, Li

    2013-01-01

    Liver-directed gene transfer and gene therapy are rapidly gaining attention primarily because the liver is centrally involved in a variety of metabolic functions that are affected in various inherited disorders. Recombinant adeno-associated virus (rAAV) is a popular gene delivery vehicle for gene therapy and intravenous delivery of some rAAV serotypes results in very efficient transduction of the liver. rAAV-mediated and liver-directed gene transfer can help in creating somatic transgenic animals or disease models and studying the function of various genes and miRNAs. The liver is the target tissue for gene therapy of many inborn metabolic diseases and may also be exploited as a “bio-factory” for the production of coagulation factors, insulin and growth hormones and other non-hepatic proteins. Hence efficient delivery of transgenes and small RNAs to the liver by rAAV vectors has been of long-standing interest to research scientists and clinicians alike. PMID:23686826

  13. Gene transfer of arginine kinase to skeletal muscle using adeno-associated virus

    PubMed Central

    Forbes, Sean C.; Bish, Lawrence T.; Ye, Fan; Spinazzola, Janelle; Baligand, Celine; Plant, Daniel; Vandenborne, Krista; Barton, Elisabeth R.; Sweeney, H. Lee; Walter, Glenn A.

    2014-01-01

    In this study we tested the feasibility of non-invasively measuring phosphoarginine (PArg) after gene delivery of arginine kinase (AK) using an adeno-associated virus (AAV) to murine hindlimbs. This was achieved by evaluating the time course, regional distribution, and metabolic flux of PArg using 31 phosphorus magnetic resonance spectroscopy (31P-MRS). AK gene was injected into the gastrocnemius of the left hindlimb of C57Bl10 mice (age 5wk, male) using self-complementary AAV, type 2/8 with desmin promoter. Non-localized 31P-MRS data were acquired over nine months after injection using 11.1-T and 17.6-T Bruker Avance spectrometers. In addition, 31P 2-D chemical shift imaging and saturation transfer experiments were performed to examine the spatial distribution and metabolic flux of PArg, respectively. PArg was evident in each injected mouse hindlimb after gene delivery, increased until 28 weeks, and remained elevated for at least nine months (p<.05). Furthermore, PArg was primarily localized to the injected posterior hindimb region with the metabolite being in exchange with ATP. Overall, the results show the viability of AAV gene transfer of AK gene to skeletal muscle, and provide support of PArg as a reporter that can be utilized to non-invasively monitor the transduction of genes for therapeutic interventions. PMID:24572791

  14. Gene transfer of arginine kinase to skeletal muscle using adeno-associated virus.

    PubMed

    Forbes, S C; Bish, L T; Ye, F; Spinazzola, J; Baligand, C; Plant, D; Vandenborne, K; Barton, E R; Sweeney, H L; Walter, G A

    2014-04-01

    In this study, we tested the feasibility of non-invasively measuring phosphoarginine (PArg) after gene delivery of arginine kinase (AK) using an adeno-associated virus (AAV) to murine hindlimbs. This was achieved by evaluating the time course, regional distribution and metabolic flux of PArg using (31)phosphorus magnetic resonance spectroscopy ((31)P-MRS). AK gene was injected into the gastrocnemius of the left hindlimb of C57Bl10 mice (age 5 weeks, male) using self-complementary AAV, type 2/8 with desmin promoter. Non-localized (31)P-MRS data were acquired over 9 months after injection using 11.1-T and 17.6-T Bruker Avance spectrometers. In addition, (31)P two-dimensional chemical shift imaging and saturation transfer experiments were performed to examine the spatial distribution and metabolic flux of PArg, respectively. PArg was evident in each injected mouse hindlimb after gene delivery, increased until 28 weeks, and remained elevated for at least 9 months (P<0.05). Furthermore, PArg was primarily localized to the injected posterior hindimb region and the metabolite was in exchange with ATP. Overall, the results show the viability of AAV gene transfer of AK gene to skeletal muscle, and provide support of PArg as a reporter that can be used to non-invasively monitor the transduction of genes for therapeutic interventions. PMID:24572791

  15. Liver-Directed Adeno-Associated Virus Serotype 8 Gene Transfer Rescues a Lethal Murine Model of Citrullinemia Type 1

    PubMed Central

    Chandler, Randy J.; Tarasenko, Tatiana N.; Cusmano-Ozog, Kristina; Sun, Qin; Sutton, V. Reid; Venditti, Charles P.; McGuire, Peter J.

    2013-01-01

    Citrullinemia type 1 (CTLN1) is an autosomal recessive disorder of metabolism caused by a deficiency of argininosuccinate synthetase. Despite optimal management, CTLN1 patients still suffer from lethal metabolic instability and experience life threatening episodes of acute hyperammonemia. A murine model of CTLN1 (fold/fold) that displays lethality within the first 21 days of life was used to determine the efficacy of adeno-associated viral (AAV) gene transfer as a potential therapy. An AAV serotype 8 (AAV8) vector was engineered to express the human ASS1 cDNA under the control of a liver-specific promoter (thyroxine binding globulin, TBG), AAV8-TBG-hASS1, and delivered to 7–10 day old mice via intraperitoneal injection. Greater than 95% of the mice were rescued from lethality and survival was extended beyond 100 days after receiving a single dose of vector. AAV8-TBG-hASS1 treatment resulted in liver specific expression of hASS1, increased ASS1 enzyme activity, reduction in plasma ammonia and citrulline concentrations, and significant phenotypic improvement of the fold/fold growth and skin phenotypes. These experiments highlight a gene transfer approach using AAV8 vector for liver targeted gene therapy that could serve as a treatment for CTLN1. PMID:24131980

  16. Adeno-associated virus-targeted disruption of the CFTR gene in cloned ferrets.

    PubMed

    Sun, Xingshen; Yan, Ziying; Yi, Yaling; Li, Ziyi; Lei, Diana; Rogers, Christopher S; Chen, Juan; Zhang, Yulong; Welsh, Michael J; Leno, Gregory H; Engelhardt, John F

    2008-04-01

    Somatic cell gene targeting combined with nuclear transfer cloning presents tremendous potential for the creation of new, large-animal models of human diseases. Mouse disease models often fail to reproduce human phenotypes, underscoring the need for the generation and study of alternative disease models. Mice deficient for CFTR have been poor models for cystic fibrosis (CF), lacking many aspects of human CF lung disease. In this study, we describe the production of a CFTR gene-deficient model in the domestic ferret using recombinant adeno-associated virus-mediated gene targeting in fibroblasts, followed by nuclear transfer cloning. As part of this approach, we developed a somatic cell rejuvenation protocol using serial nuclear transfer to produce live CFTR-deficient clones from senescent gene-targeted fibroblasts. We transferred 472 reconstructed embryos into 11 recipient jills and obtained 8 healthy male ferret clones heterozygous for a disruption in exon 10 of the CFTR gene. To our knowledge, this study represents the first description of genetically engineered ferrets and describes an approach that may be of substantial utility in modeling not only CF, but also other genetic diseases. PMID:18324338

  17. Overcoming the Cystic Fibrosis Sputum Barrier to Leading Adeno-associated Virus Gene Therapy Vectors

    PubMed Central

    Schuster, Benjamin S; Kim, Anthony J; Kays, Joshua C; Kanzawa, Mia M; Guggino, William B; Boyle, Michael P; Rowe, Steven M; Muzyczka, Nicholas; Suk, Jung Soo; Hanes, Justin

    2014-01-01

    Gene therapy has not yet improved cystic fibrosis (CF) patient lung function in human trials, despite promising preclinical studies. In the human CF lung, inhaled gene vectors must penetrate the viscoelastic secretions coating the airways to reach target cells in the underlying epithelium. We investigated whether CF sputum acts as a barrier to leading adeno-associated virus (AAV) gene vectors, including AAV2, the only serotype tested in CF clinical trials, and AAV1, a leading candidate for future trials. Using multiple particle tracking, we found that sputum strongly impeded diffusion of AAV, regardless of serotype, by adhesive interactions and steric obstruction. Approximately 50% of AAV vectors diffused >1,000-fold more slowly in sputum than in water, with large patient-to-patient variation. We thus tested two strategies to improve AAV diffusion in sputum. We showed that an AAV2 mutant engineered to have reduced heparin binding diffused twice as fast as AAV2 on average, presumably because of reduced adhesion to sputum. We also discovered that the mucolytic N-acetylcysteine could markedly enhance AAV diffusion by altering the sputum microstructure. These studies underscore that sputum is a major barrier to CF gene delivery, and offer strategies for increasing AAV penetration through sputum to improve clinical outcomes. PMID:24869933

  18. The SUMOylation Pathway Restricts Gene Transduction by Adeno-Associated Viruses

    PubMed Central

    Henrich, Katharina; Chen, Qingxin; Beneke, Jürgen; Matula, Petr; Rohr, Karl; Kaderali, Lars; Beil, Nina; Erfle, Holger; Kleinschmidt, Jürgen A.; Müller, Martin

    2015-01-01

    Adeno-associated viruses are members of the genus dependoviruses of the parvoviridae family. AAV vectors are considered promising vectors for gene therapy and genetic vaccination as they can be easily produced, are highly stable and non-pathogenic. Nevertheless, transduction of cells in vitro and in vivo by AAV in the absence of a helper virus is comparatively inefficient requiring high multiplicity of infection. Several bottlenecks for AAV transduction have previously been described, including release from endosomes, nuclear transport and conversion of the single stranded DNA into a double stranded molecule. We hypothesized that the bottlenecks in AAV transduction are, in part, due to the presence of host cell restriction factors acting directly or indirectly on the AAV-mediated gene transduction. In order to identify such factors we performed a whole genome siRNA screen which identified a number of putative genes interfering with AAV gene transduction. A number of factors, yielding the highest scores, were identified as members of the SUMOylation pathway. We identified Ubc9, the E2 conjugating enzyme as well as Sae1 and Sae2, enzymes responsible for activating E1, as factors involved in restricting AAV. The restriction effect, mediated by these factors, was validated and reproduced independently. Our data indicate that SUMOylation targets entry of AAV capsids and not downstream processes of uncoating, including DNA single strand conversion or DNA damage signaling. We suggest that transiently targeting SUMOylation will enhance application of AAV in vitro and in vivo. PMID:26625259

  19. The adeno-associated virus rep gene suppresses herpes simplex virus-induced DNA amplification.

    PubMed Central

    Heilbronn, R; Bürkle, A; Stephan, S; zur Hausen, H

    1990-01-01

    Herpes simplex virus (HSV) induces within the host cell genome DNA amplification which can be suppressed by coinfection with adeno-associated virus (AAV). To characterize the AAV functions mediating this effect, cloned AAV type 2 wild-type or mutant genomes were transfected into simian virus 40 (SV40)-transformed hamster cells together with the six HSV replication genes (encoding UL5, UL8, major DNA-binding protein, DNA polymerase, UL42, and UL52) which together are necessary and sufficient for the induction of SV40 DNA amplification (R. Heilbronn and H. zur Hausen, J. Virol. 63:3683-3692, 1989). The AAV rep gene was identified as being responsible for the complete inhibition of HSV-induced SV40 DNA amplification. Likewise, rep inhibited origin-dependent HSV replication. rep neither killed the transfected host cells nor interfered with gene expression from the cotransfected amplification genes. This points to a specific interference with HSV-induced DNA amplification. Images PMID:2159559

  20. Adeno-associated virus–targeted disruption of the CFTR gene in cloned ferrets

    PubMed Central

    Sun, Xingshen; Yan, Ziying; Yi, Yaling; Li, Ziyi; Lei, Diana; Rogers, Christopher S.; Chen, Juan; Zhang, Yulong; Welsh, Michael J.; Leno, Gregory H.; Engelhardt, John F.

    2008-01-01

    Somatic cell gene targeting combined with nuclear transfer cloning presents tremendous potential for the creation of new, large-animal models of human diseases. Mouse disease models often fail to reproduce human phenotypes, underscoring the need for the generation and study of alternative disease models. Mice deficient for CFTR have been poor models for cystic fibrosis (CF), lacking many aspects of human CF lung disease. In this study, we describe the production of a CFTR gene–deficient model in the domestic ferret using recombinant adeno-associated virus–mediated gene targeting in fibroblasts, followed by nuclear transfer cloning. As part of this approach, we developed a somatic cell rejuvenation protocol using serial nuclear transfer to produce live CFTR-deficient clones from senescent gene-targeted fibroblasts. We transferred 472 reconstructed embryos into 11 recipient jills and obtained 8 healthy male ferret clones heterozygous for a disruption in exon 10 of the CFTR gene. To our knowledge, this study represents the first description of genetically engineered ferrets and describes an approach that may be of substantial utility in modeling not only CF, but also other genetic diseases. PMID:18324338

  1. Noninvasive, neuron-specific gene therapy can be facilitated by focused ultrasound and recombinant adeno-associated virus.

    PubMed

    Wang, S; Olumolade, O O; Sun, T; Samiotaki, G; Konofagou, E E

    2015-01-01

    Recombinant adeno-associated virus (rAAV) has shown great promise as a potential cure for neurodegenerative diseases. The existence of the blood-brain barrier (BBB), however, hinders efficient delivery of the viral vectors. Direct infusion through craniotomy is the most commonly used approach to achieve rAAV delivery, which carries increased risks of infection and other complications. Here, we report a focused ultrasound (FUS)-facilitated noninvasive rAAV delivery paradigm that is capable of producing targeted and neuron-specific transductions. Oscillating ultrasound contrast agents (microbubbles), driven by FUS waves, temporarily 'unlock' the BBB, allowing the systemically administrated rAAVs to enter the brain parenchyma, while maintaining their bioactivity and selectivity. Taking the advantage of the neuron-specific promoter synapsin, rAAV gene expression was triggered almost exclusively (95%) in neurons of the targeted caudate-putamen region. Both behavioral assessment and histological examination revealed no significant long-term adverse effects (in the brain and several other critical organs) for this combined treatment paradigm. Results from this study demonstrated the feasibility and safety for the noninvasive, targeted rAAV delivery, which might have open a new avenue in gene therapy in both preclinical and clinical settings. PMID:25354683

  2. Non-invasive, neuron-specific gene therapy can be facilitated by focused ultrasound and recombinant adeno-associated virus

    PubMed Central

    Wang, Shutao; Olumolade, Oluyemi O.; Sun, Tao; Samiotaki, Gesthimani; Konofagou, Elisa E.

    2015-01-01

    Recombinant adeno-associated virus (rAAV) has shown great promise as a potential cure for neurodegenerative diseases. The existence of the blood-brain barrier (BBB), however, hinders efficient delivery of the viral vectors. Direct infusion through craniotomy is the most commonly used approach to achieve rAAV delivery, which carries increased risks of infection and other complications. Here we report a focused ultrasound (FUS) facilitated, non-invasive rAAV delivery paradigm that is capable of producing targeted and neuron-specific transductions. Oscillating ultrasound contrast agents (i.e. microbubbles), driven by focused ultrasound waves, temporarily “unlocking” the BBB, allowing the systemically administrated rAAVs to enter the brain parenchyma, while maintaining their bioactivity and selectivity. Taking the advantage of the neuron-specific promoter-synapsin, rAAV gene expression was triggered almost exclusively (95%) in neurons of the targeted (i.e. caudate-putamen) region. Both behavioral assessment and histological examination revealed no significant long term adverse effects (in the brain and several other critical organs) for this combined treatment paradigm. Results from this study demonstrated the feasibility and safety for the non-invasive, targeted rAAV delivery technique, which might have provided a new arena for gene therapy in both pre-clinical and clinical settings. PMID:25354683

  3. In vivo evaluation of adeno-associated virus gene transfer in airways of mice with acute or chronic respiratory infection.

    PubMed

    Myint, Melissa; Limberis, Maria P; Bell, Peter; Somanathan, Suryanarayan; Haczku, Angela; Wilson, James M; Diamond, Scott L

    2014-11-01

    Patients with cystic fibrosis (CF) often suffer chronic lung infection with concomitant inflammation, a setting that may reduce the efficacy of gene transfer. While gene therapy development for CF often involves viral-based vectors, little is known about gene transfer in the context of an infected airway. In this study, three mouse models were established to evaluate adeno-associated virus (AAV) gene transfer in such an environment. Bordetella bronchiseptica RB50 was used in a chronic, nonlethal respiratory infection in C57BL/6 mice. An inoculum of ∼10(5) CFU allowed B. bronchiseptica RB50 to persist in the upper and lower respiratory tracts for at least 21 days. In this infection model, administration of an AAV vector on day 2 resulted in 2.8-fold reduction of reporter gene expression compared with that observed in uninfected controls. Postponement of AAV administration to day 14 resulted in an even greater (eightfold) reduction of reporter gene expression, when compared with uninfected controls. In another infection model, Pseudomonas aeruginosa PAO1 was used to infect surfactant protein D (SP-D) or surfactant protein A (SP-A) knockout (KO) mice. With an inoculum of ∼10(5) CFU, infection persisted for 2 days in the nasal cavity of either mouse model. Reporter gene expression was approximately ∼2.5-fold lower compared with uninfected mice. In the SP-D KO model, postponement of AAV administration to day 9 postinfection resulted in only a two fold reduction in reporter gene expression, when compared with expression seen in uninfected controls. These results confirm that respiratory infections, both ongoing and recently resolved, decrease the efficacy of AAV-mediated gene transfer. PMID:25144316

  4. Quantitative comparison of expression with adeno-associated virus (AAV-2) brain-specific gene cassettes.

    PubMed

    Xu, R; Janson, C G; Mastakov, M; Lawlor, P; Young, D; Mouravlev, A; Fitzsimons, H; Choi, K L; Ma, H; Dragunow, M; Leone, P; Chen, Q; Dicker, B; During, M J

    2001-09-01

    This study compared a range of mammalian CNS expression cassettes in recombinant adeno-associated virus (AAV-2) vectors using strong endogenous promoter sequences, with or without a strong post-regulatory element and polyadenylation signal. Changes in these elements led to transgene expression varying by over three orders of magnitude. In experiments conducted in primary cell culture and in >100 stereotactically injected rats, we observed highly efficient and stable (>15 months) gene expression in neurons and limited expression in glia; the highest expression occurred with endogenous, nonviral promoters such as neuron-specific enolase and beta-actin. The packaging size of AAV-2 was maximized at 5.7 kb without impairing gene expression, as judged by direct comparison with a number of smaller AAV-2 constructs. The genomic insert size and titer were confirmed by Southern blot and quantitative PCR, and infectivity was tested by particle titer using ELISA with a conformation-dependent epitope that requires the full intact capsid. A packaging and purification protocol we describe allows for high-titer, high-capacity AAV-2 vectors that can transduce over 2 x 10(5) neurons in vivo per microliter of vector, using the strongest expression cassette. PMID:11571569

  5. Translational data from adeno-associated virus-mediated gene therapy of hemophilia B in dogs.

    PubMed

    Nichols, Timothy C; Whitford, Margaret H; Arruda, Valder R; Stedman, Hansell H; Kay, Mark A; High, Katherine A

    2015-03-01

    Preclinical testing of new therapeutic strategies in relevant animal models is an essential part of drug development. The choice of animal models of disease that are used in these studies is driven by the strength of the translational data for informing about safety, efficacy, and success or failure of human clinical trials. Hemophilia B is a monogenic, X-linked, inherited bleeding disorder that results from absent or dysfunctional coagulation factor IX (FIX). Regarding preclinical studies of adeno-associated virus (AAV)-mediated gene therapy for hemophilia B, dogs with severe hemophilia B (<1% FIX) provide well-characterized phenotypes and genotypes in which a species-specific transgene can be expressed in a mixed genetic background. Correction of the hemophilic coagulopathy by sustained expression of FIX, reduction of bleeding events, and a comprehensive assessment of the humoral and cell-mediated immune responses to the expressed transgene and recombinant AAV vector are all feasible end points in these dogs. This review compares the preclinical studies of AAV vectors used to treat dogs with hemophilia B with the results obtained in subsequent human clinical trials using muscle- and liver-based approaches. PMID:25675273

  6. Non-viral adeno-associated virus-based platform for stable expression of antibody combination therapeutics.

    PubMed

    Wilmes, Gwendolyn M; Carey, Kimberly L; Hicks, Stuart W; Russell, Hugh H; Stevenson, Jesse A; Kocjan, Paulina; Lutz, Stephen R; Quesenberry, Rachel S; Shulga-Morskoy, Sergey V; Lewis, Megan E; Clark, Ethan; Medik, Violetta; Cooper, Anthony B; Reczek, Elizabeth E

    2014-01-01

    Antibody combination therapeutics (ACTs) are polyvalent biopharmaceuticals that are uniquely suited for the control of complex diseases, including antibiotic resistant infectious diseases, autoimmune disorders and cancers. However, ACTs also represent a distinct manufacturing challenge because the independent manufacture and subsequent mixing of monoclonal antibodies quickly becomes cost prohibitive as more complex mixtures are envisioned. We have developed a virus-free recombinant protein expression platform based on adeno-associated viral (AAV) elements that is capable of rapid and consistent production of complex antibody mixtures in a single batch format. Using both multiplexed immunoassays and cation exchange (CIEX) chromatography, cell culture supernatants generated using our system were assessed for stability of expression and ratios of the component antibodies over time. Cultures expressing combinations of three to ten antibodies maintained consistent expression levels and stable ratios of component antibodies for at least 60 days. Cultures showed remarkable reproducibility following cell banking, and AAV-based cultures showed higher stability and productivity than non-AAV based cultures. Therefore, this non-viral AAV-based expression platform represents a predictable, reproducible, quick and cost effective method to manufacture or quickly produce for preclinical testing recombinant antibody combination therapies and other recombinant protein mixtures. PMID:24758837

  7. Non-viral adeno-associated virus-based platform for stable expression of antibody combination therapeutics

    PubMed Central

    Wilmes, Gwendolyn M; Carey, Kimberly L; Hicks, Stuart W; Russell, Hugh H; Stevenson, Jesse A; Kocjan, Paulina; Lutz, Stephen R; Quesenberry, Rachel S; Shulga-Morskoy, Sergey V; Lewis, Megan E; Clark, Ethan; Medik, Violetta; Cooper, Anthony B; Reczek, Elizabeth E

    2014-01-01

    Antibody combination therapeutics (ACTs) are polyvalent biopharmaceuticals that are uniquely suited for the control of complex diseases, including antibiotic resistant infectious diseases, autoimmune disorders and cancers. However, ACTs also represent a distinct manufacturing challenge because the independent manufacture and subsequent mixing of monoclonal antibodies quickly becomes cost prohibitive as more complex mixtures are envisioned. We have developed a virus-free recombinant protein expression platform based on adeno-associated viral (AAV) elements that is capable of rapid and consistent production of complex antibody mixtures in a single batch format. Using both multiplexed immunoassays and cation exchange (CIEX) chromatography, cell culture supernatants generated using our system were assessed for stability of expression and ratios of the component antibodies over time. Cultures expressing combinations of three to ten antibodies maintained consistent expression levels and stable ratios of component antibodies for at least 60 days. Cultures showed remarkable reproducibility following cell banking, and AAV-based cultures showed higher stability and productivity than non-AAV based cultures. Therefore, this non-viral AAV-based expression platform represents a predictable, reproducible, quick and cost effective method to manufacture or quickly produce for preclinical testing recombinant antibody combination therapies and other recombinant protein mixtures. PMID:24758837

  8. The impact of minimally oversized adeno-associated viral vectors encoding human factor VIII on vector potency in vivo

    PubMed Central

    Kyostio-Moore, Sirkka; Berthelette, Patricia; Piraino, Susan; Sookdeo, Cathleen; Nambiar, Bindu; Jackson, Robert; Burnham, Brenda; O’Riordan, Catherine R; Cheng, Seng H; Armentano, Donna

    2016-01-01

    Recombinant adeno-associated viral (rAAV) vectors containing oversized genomes provide transgene expression despite low efficiency packaging of complete genomes. Here, we characterized the properties of oversized rAAV2/8 vectors (up to 5.4 kb) encoding human factor VIII (FVIII) under the transcriptional control of three liver promoters. All vectors provided sustained production of active FVIII in mice for 7 months and contained comparable levels of vector genomes and complete expression cassettes in liver. Therefore, for the 5.4 kb genome size range, a strong expression cassette was more important for FVIII production than the vector genome size. To evaluate the potency of slightly oversized vectors, a 5.1 kb AAVrh8R/FVIII vector was compared to a 4.6 kb (wild-type size) vector with an identical expression cassette (but containing a smaller C1-domain deleted FVIII) for 3 months in mice. The 5.1 kb vector had twofold to threefold lower levels of plasma FVIII protein and liver vector genomes than that obtained with the 4.6 kb vector. Vector genomes for both vectors persisted equally and existed primarily as high molecular weight concatemeric circular forms in liver. Taken together, these results indicate that the slightly oversized vectors containing heterogeneously packaged vector genomes generated a functional transgene product but exhibited a twofold to threefold lower in vivo potency. PMID:26958574

  9. Developing immunologically inert adeno-associated virus (AAV) vectors for gene therapy: possibilities and limitations.

    PubMed

    Selot, Ruchita S; Hareendran, Sangeetha; Jayandharan, Giridhara R

    2014-01-01

    Gene therapy has become a clinical reality as demonstrated by remarkable benefits seen in Phase I/II clinical trials for hemophilia B, lipoprotein lipase deficiency and Leber's congenital amarousis. The choice of, and the improved understanding in vector characteristics have contributed significantly to this success. The adeno-associated virus (AAV) vectors used in these trials have been long known to be relatively safe and efficacious. However, certain factors, most notably host immunity to the vector, prevent their widespread use. In patients who have pre-existing antibodies to AAV, these vectors will be rapidly cleared. Administration of a relatively high initial dose of vector to achieve and sustain a higher margin of therapeutic benefit is limited by concerns of vector dose-dependent T cell response. Frequent vector administration necessitated by the non-integrating nature of the virus is difficult due to the variable, yet significant host immunological memory. Thus generation of AAV vectors that are immunologically inert is pivotal for the long-term success with this promising vector system. Several strategies, that aim targeted disruption of antigenic sites or those that chemically modify the vectors have been proposed for host immune evasion. While these approaches have been successful in the pre-clinical model systems, this continues to be a field of intense experimentation and constant improvisation due to limited information available on vector immunology or data from human studies. This review forms a comprehensive report on current strategies available to generate immunologically inert AAV vectors and their potential in mediating longterm gene transfer. PMID:24678652

  10. Genetic Manipulation of Brown Fat Via Oral Administration of an Engineered Recombinant Adeno-associated Viral Serotype Vector.

    PubMed

    Huang, Wei; McMurphy, Travis; Liu, Xianglan; Wang, Chuansong; Cao, Lei

    2016-06-01

    Recombinant adeno-associated virus (rAAV) vectors are attractive vehicles for gene therapy. Gene delivery to the adipose tissue using naturally occurring AAV serotypes is less successful compared to liver and muscle. Here, we demonstrate that oral administration of an engineered serotype Rec2 led to preferential transduction of brown fat with absence of transduction in the gastrointestinal track. Among the six natural and engineered serotypes being compared, Rec2 was the most efficient serotype achieving high level transduction at a dose 1~2 orders lower than reported doses for systemic administration. Overexpressing vascular endothelial growth factor (VEGF) in brown fat via oral administration of Rec2-VEGF vector increased the brown fat mass and enhanced thermogenesis. In contrast, knockdown VEGF in brown fat of VEGF (loxP) mice via Rec2-Cre vector hampered cold response and decreased brown fat mass. Oral administration of Rec2 vector provides a novel tool to genetically manipulate brown fat for research and therapeutic applications. PMID:26857843

  11. Systemic Trans-splicing adeno-associated viral delivery efficiently transduces the heart of adult mdx mouse, a model for duchenne muscular dystrophy.

    PubMed

    Ghosh, Arkasubhra; Yue, Yongping; Shin, Jin-Hong; Duan, Dongsheng

    2009-11-01

    Trans-splicing adeno-associated viral (tsAAV) vectors hold great promise for delivering large therapeutic genes. One potential application is in the treatment of Duchenne muscular dystrophy (DMD). In this case, it is necessary to transduce whole body muscle. We demonstrated body-wide AAV-9 tsAAV transduction in normal neonatal mice. However, it was not clear whether such an approach would work in diseased mice. In this study we delivered the AAV-9 alkaline phosphatase (AP) tsAAV vector (3 x 10(12) vector genome particles per vector per mouse, tail vein injection) to 2-month-old mdx mice, the most widely used DMD model. Four months later, we observed widespread AP expression in the heart. It reached the same level as we have seen in normal neonatal puppy. Interestingly, myocardial transduction correlated with beta-myosin heavy chain expression but not with LamR, the putative AAV-9 receptor. AP expression was also detected in various skeletal muscles but at levels much lower than in normal newborn mice. Despite the existing inflammatory milieu, we did not see any appreciable increase in CD4(+) and CD8(+) T cells and macrophages in striated muscles after systemic tsAAV infection. In summary, our results have paved the way for tsAAV-mediated gene therapy for Duchenne cardiomyopathy. PMID:19627234

  12. Tissue-Specific Expression of Herpes Simplex Virus Thymidine Kinase Gene Delivered by Adeno-Associated Virus Inhibits the Growth of Human Hepatocellular Carcinoma in Athymic Mice

    NASA Astrophysics Data System (ADS)

    Su, Hua; Lu, Ronghua; Chang, Judy C.; Kan, Yuet Wai

    1997-12-01

    About 70% of hepatocellular carcinomas are known to express α -fetoprotein, which is normally expressed in fetal but not in adult livers. To induce herpes simplex virus-thymidine kinase expression in these cancer cells, we constructed an adeno-associated viral vector containing the HSV-TK gene under the control of the α -fetoprotein enhancer and albumin promoter. We previously demonstrated in vitro that although this vector can transduce a variety of human cells, only transduced AFP and albumin-expressing hepatocellular carcinoma cell lines were sensitive to killing by ganciclovir (GCV). In the present study, we explored the effect of this vector on hepatocellular carcinoma cells in vivo. Subcutaneous tumors generated in nude mice by implanting hepatocellular carcinoma cells previously transduced with this vector shrank dramatically after treatment with GCV. Bystander effect was also observed on the tumors generated by mixing transduced and untransduced cells. To test whether the tumor cells can be transduced by the virus in vivo, we injected the recombinant adeno-associated virus into tumors generated by untransduced hepatocarcinoma cell line. Tumor growth were retarded after treatment with GCV. These experiments demonstrate the feasibility of in vivo transduction of tumor cell with rAAV.

  13. Differential Type I Interferon-dependent Transgene Silencing of Helper-dependent Adenoviral vs. Adeno-associated Viral Vectors In Vivo

    PubMed Central

    Suzuki, Masataka; Bertin, Terry K; Rogers, Geoffrey L; Cela, Racel G; Zolotukhin, Irene; Palmer, Donna J; Ng, Philip; Herzog, Roland W; Lee, Brendan

    2013-01-01

    We previously dissected the components of the innate immune response to Helper-dependent adenoviral vectors (HDAds) using genetic models, and demonstrated that multiple pattern recognition receptor signaling pathways contribute to this host response to HDAds in vivo. Based on analysis of cytokine expression profiles, type I interferon (IFN) mRNA is induced in host mouse livers at 1 hour post-injection. This type I IFN signaling amplifies cytokine expression in liver independent of the nature of vector DNA sequences after 3 hours post-injection. This type I IFN signaling in response to HDAds administration contributes to transcriptional silencing of both HDAd prokaryotic and eukaryotic DNA in liver. This silencing occurs early and is mediated by epigenetic modification as shown by in vivo chromatin immunoprecipitation (ChIP) with anti-histone deacetylase (HDAC) and promyelocytic leukemia protein (PML). In contrast, self-complementary adeno-associated viral vectors (scAAVs) showed significantly lower induction of type I IFN mRNA in liver compared to HDAds at both early and late time points. These results show that the type I IFN signaling dependent transgene silencing differs between AAV and HDAd vectors after liver-directed gene transfer. PMID:23319058

  14. Targeted Modifications in Adeno-Associated Virus Serotype 8 Capsid Improves Its Hepatic Gene Transfer Efficiency In Vivo

    PubMed Central

    Sen, Dwaipayan; Gadkari, Rupali A; Sudha, Govindarajan; Gabriel, Nishanth; Kumar, Yesupatham Sathish; Selot, Ruchita; Samuel, Rekha; Rajalingam, Sumathi; Ramya, V.; Nair, Sukesh C.; Srinivasan, Narayanaswamy; Srivastava, Alok

    2013-01-01

    Abstract Recombinant adeno-associated virus vectors based on serotype 8 (AAV8) have shown significant promise for liver-directed gene therapy. However, to overcome the vector dose dependent immunotoxicity seen with AAV8 vectors, it is important to develop better AAV8 vectors that provide enhanced gene expression at significantly low vector doses. Since it is known that AAV vectors during intracellular trafficking are targeted for destruction in the cytoplasm by the host–cellular kinase/ubiquitination/proteasomal machinery, we modified specific serine/threonine kinase or ubiquitination targets on the AAV8 capsid to augment its transduction efficiency. Point mutations at specific serine (S)/threonine (T)/lysine (K) residues were introduced in the AAV8 capsid at the positions equivalent to that of the effective AAV2 mutants, generated successfully earlier. Extensive structure analysis was carried out subsequently to evaluate the structural equivalence between the two serotypes. scAAV8 vectors with the wild-type (WT) and each one of the S/T→Alanine (A) or K-Arginine (R) mutant capsids were evaluated for their liver transduction efficiency in C57BL/6 mice in vivo. Two of the AAV8-S→A mutants (S279A and S671A), and a K137R mutant vector, demonstrated significantly higher enhanced green fluorescent protein (EGFP) transcript levels (∼9- to 46-fold) in the liver compared to animals that received WT-AAV8 vectors alone. The best performing AAV8 mutant (K137R) vector also had significantly reduced ubiquitination of the viral capsid, reduced activation of markers of innate immune response, and a concomitant two-fold reduction in the levels of neutralizing antibody formation in comparison to WT-AAV8 vectors. Vector biodistribution studies revealed that the K137R mutant had a significantly higher and preferential transduction of the liver (106 vs. 7.7 vector copies/mouse diploid genome) when compared to WT-AAV8 vectors. To further study the utility of the K137R-AAV8

  15. Adeno-Associated Virus at 50: A Golden Anniversary of Discovery, Research, and Gene Therapy Success—A Personal Perspective

    PubMed Central

    Hastie, Eric

    2015-01-01

    Abstract Fifty years after the discovery of adeno-associated virus (AAV) and more than 30 years after the first gene transfer experiment was conducted, dozens of gene therapy clinical trials are in progress, one vector is approved for use in Europe, and breakthroughs in virus modification and disease modeling are paving the way for a revolution in the treatment of rare diseases, cancer, as well as HIV. This review will provide a historical perspective on the progression of AAV for gene therapy from discovery to the clinic, focusing on contributions from the Samulski lab regarding basic science and cloning of AAV, optimized large-scale production of vectors, preclinical large animal studies and safety data, vector modifications for improved efficacy, and successful clinical applications. PMID:25807962

  16. Characterization of Wild-Type Adeno-Associated Virus Type 2-Like Particles Generated during Recombinant Viral Vector Production and Strategies for Their Elimination

    PubMed Central

    Wang, Xu-Shan; Khuntirat, Benjawan; Qing, Keyun; Ponnazhagan, Selvarangan; Kube, Dagmar M.; Zhou, Shangzhen; Dwarki, Varavani J.; Srivastava, Arun

    1998-01-01

    The pSub201-pAAV/Ad plasmid cotransfection system was developed to eliminate homologous recombination which leads to generation of the wild-type (wt) adeno-associated virus type 2 (AAV) during recombinant vector production. The extent of contamination with wt AAV has been documented to range between 0.01 and 10%. However, the precise mechanism of generation of the contaminating wt AAV remains unclear. To characterize the wt AAV genomes, recombinant viral stocks were used to infect human 293 cells in the presence of adenovirus. Southern blot analyses of viral replicative DNA intermediates revealed that the contaminating AAV genomes were not authentic wt but rather wt AAV-like sequences derived from recombination between (i) AAV inverted terminal repeats (ITRs) in the recombinant plasmid and (ii) AAV sequences in the helper plasmid. Replicative AAV DNA fragments, isolated following amplification through four successive rounds of amplification in adenovirus-infected 293 cells, were molecularly cloned and subjected to nucleotide sequencing to identify the recombinant junctions. Following sequence analyses of 31 different ends of AAV-like genomes derived from two different recombinant vector stocks, we observed that all recombination events involved 10 nucleotides in the AAV D sequence distal to viral hairpin structures. We have recently documented that the first 10 nucleotides in the D sequence proximal to the AAV hairpin structures are essential for successful replication and encapsidation of the viral genome (X.-S. Wang et al., J. Virol. 71:3077–3082, 1997), and it was noteworthy that in each recombinant junction sequenced, the same 10 nucleotides were retained. We also observed that adenovirus ITRs in the helper plasmid were involved in illegitimate recombination with AAV ITRs, deletions of which significantly reduced the extent of wt AAV-like particles. Furthermore, the combined use of recombinant AAV plasmids lacking the distal 10 nucleotides in the D sequence

  17. X-Linked Inhibitor of Apoptosis Protein-Mediated Attenuation of Apoptosis, Using a Novel Cardiac-Enhanced Adeno-Associated Viral Vector

    PubMed Central

    Piacentino III, Valentino; Milano, Carmelo A.; Bolanos, Michael; Schroder, Jacob; Messina, Emily; Cockrell, Adam S.; Jones, Edward; Krol, Ava; Bursac, Nenad; Mao, Lan; Devi, Gayathri R.; Samulski, R. Jude

    2012-01-01

    Abstract Successful amelioration of cardiac dysfunction and heart failure through gene therapy approaches will require a transgene effective at attenuating myocardial injury, and subsequent remodeling, using an efficient and safe delivery vehicle. Our laboratory has established a well-curated, high-quality repository of human myocardial tissues that we use as a discovery engine to identify putative therapeutic transgene targets, as well as to better understand the molecular basis of human heart failure. By using this rare resource we were able to examine age- and sex-matched left ventricular samples from (1) end-stage failing human hearts and (2) nonfailing human hearts and were able to identify the X-linked inhibitor of apoptosis protein (XIAP) as a novel target for treating cardiac dysfunction. We demonstrate that XIAP is diminished in failing human hearts, indicating that this potent inhibitor of apoptosis may be central in protecting the human heart from cellular injury culminating in heart failure. Efforts to ameliorate heart failure through delivery of XIAP compelled the design of a novel adeno-associated viral (AAV) vector, termed SASTG, that achieves highly efficient transduction in mouse heart and in cultured neonatal rat cardiomyocytes. Increased XIAP expression achieved with the SASTG vector inhibits caspase-3/7 activity in neonatal cardiomyocytes after induction of apoptosis through three common cardiac stresses: protein kinase C-γ inhibition, hypoxia, or β-adrenergic receptor agonist. These studies demonstrate the potential benefit of XIAP to correct heart failure after highly efficient delivery to the heart with the rationally designed SASTG AAV vector. PMID:22339372

  18. Long-Term Rescue of Retinal Structure and Function by Rhodopsin RNA Replacement with a Single Adeno-Associated Viral Vector in P23H RHO Transgenic Mice

    PubMed Central

    Mao, Haoyu; Gorbatyuk, Marina S.; Rossmiller, Brian; Hauswirth, William W.

    2012-01-01

    Abstract Many mutations in the human rhodopsin gene (RHO) cause autosomal dominant retinitis pigmentosa (ADRP). Our previous studies with a P23H (proline-23 substituted by histidine) RHO transgenic mouse model of ADRP demonstrated significant improvement of retinal function and preservation of retinal structure after transfer of wild-type rhodopsin by AAV. In this study we demonstrate long-term rescue of retinal structure and function by a single virus expressing both RHO replacement cDNA and small interfering RNA (siRNA) to digest mouse Rho and human P23H RHO mRNA. This combination should prevent overexpression of rhodopsin, which can be deleterious to photoreceptors. On the basis of the electroretinogram (ERG) response, degeneration of retinal function was arrested at 2 months postinjection, and the response was maintained at this level until termination at 9 months. Preservation of the ERG response in P23H RHO mice reflected survival of photoreceptors: both the outer nuclear layer (ONL) and outer segments of photoreceptor cells maintained the same thickness as in nontransgenic mice, whereas the control injected P23H eyes exhibited severe thinning of the ONL and outer segments. These findings suggest that delivery of both a modified cDNA and an siRNA by a single adeno-associated viral vector provided long-term rescue of ADRP in this model. Because the siRNA targets human as well as mouse rhodopsin mRNAs, the combination vector may be useful for the treatment of human disease. PMID:22289036

  19. Adeno-Associated Virus (AAV) Mediated Dystrophin Gene Transfer Studies and Exon Skipping Strategies for Duchenne Muscular Dystrophy (DMD).

    PubMed

    Kawecka, Klaudia; Theodoulides, Michael; Hasoglu, Yalin; Jarmin, Susan; Kymalainen, Hanna; Le-Heron, Anita; Popplewell, Linda; Malerba, Alberto; Dickson, George; Athanasopoulos, Takis

    2015-01-01

    Duchenne muscular dystrophy (DMD), an X-linked inherited musclewasting disease primarily affecting young boys with prevalence of between1:3,500- 1:5,000, is a rare genetic disease caused by defects in the gene for dystrophin. Dystrophin protein is critical to the stability of myofibers in skeletal and cardiac muscle. There is currently no cure available to ameliorate DMD and/or its patho-physiology. A number of therapeutic strategies including molecular-based therapeutics that replace or correct the missing or nonfunctional dystrophin protein have been devised to correct the patho-physiological consequences induced by dystrophin absence. We will review the current in vivo experimentation status (including preclinical models and clinical trials) for two of these approaches, namely: 1) Adeno-associated virus (AAV) mediated (micro) dystrophin gene augmentation/ supplementation and 2) Antisense oligonucleotide (AON)-mediated exon skipping strategies. PMID:26159373

  20. Determination of Anti-Adeno-Associated Viral Vector Neutralizing Antibodies in Patients With Heart Failure in the Cardiovascular Foundation of Colombia (ANVIAS): Study Protocol

    PubMed Central

    Prada, Carlos E; Lopez, Marcos; Castillo, Victor; Echeverria, Luis Eduardo; Serrano, Norma

    2016-01-01

    Background Recent progress in the pathophysiology of heart failure (HF) has led to the development of new therapeutic options such as gene therapy and the use of adeno-associated viral (AAV) vectors. Despite the promising results in early clinical trials of gene therapy for HF, various obstacles have been faced, such as the presence of neutralizing antibodies (NAbs) against the capsid vectors. NAb activity limits vector transduction levels and therefore diminishes the final therapeutic response. Recent studies evaluating the prevalence of NAbs in various populations found considerable geographic variability for each AAV serotype. However, the levels of NAbs in Latin American populations are unknown, becoming a limiting factor to conducting AAV vector therapeutic trials in this population. Objective The goal of this study is to determine for the first time, the prevalence of anti-AAV NAbs for the serotypes 1, 2, and 9 in HF patients from the city of Bucaramanga, Colombia, using the in vitro transduction inhibition assay. Methods We will conduct a cross-sectional study with patients who periodically attend the HF clinic of the Cardiovascular Foundation of Colombia and healthy volunteers matched for age and sex. For all participants, we will evaluate the NAb levels against serotypes AAV1, AAV2, and AAV9. We will determine NAb levels using the in vitro transduction inhibition assay. In addition, participants will answer a survey to evaluate their epidemiological and socioeconomic variables. Participation in the study will be voluntary and all participants will sign an informed consent document before any intervention. Results The project is in the first phase: elaboration of case report forms and the informed consent form, and design of the recruitment strategy. Patient recruitment is expected to begin in the spring of 2016. We expect to have preliminary results, including the titer of the viral vectors, multiplicity of infections that we will use for each serotype

  1. Adeno-associated virus: fit to serve.

    PubMed

    Zinn, Eric; Vandenberghe, Luk H

    2014-10-01

    Adeno-associated virus (AAV) is a helper-dependent parvovirus which has not been linked with human disease. This aspect, in combination with its broad cell and tissue tropism, and limited viral host response has made it an attractive vector system for gene therapy. The viral protein capsid, the primary interface with the host, is the main determinant for these phenotypes, is highly variable, and is most subject to pressures during replication. Here, we explore the evolutionary path of AAV and other parvoviruses in respect to these phenotypes, as well as directed evolution and engineering strategies that have exploited the lessons learned from natural selection in order to address remaining limitations of AAV as a therapeutic gene transfer platform. PMID:25128609

  2. Supraspinal gene transfer by intrathecal adeno-associated virus serotype 5.

    PubMed

    Schuster, Daniel J; Belur, Lalitha R; Riedl, Maureen S; Schnell, Stephen A; Podetz-Pedersen, Kelly M; Kitto, Kelley F; McIvor, R Scott; Vulchanova, Lucy; Fairbanks, Carolyn A

    2014-01-01

    We report the pattern of transgene expression across brain regions after intrathecal delivery of adeno-associated virus serotype 5 (AAV5). Labeling in hindbrain appeared to be primarily neuronal, and was detected in sensory nuclei of medulla, pontine nuclei, and all layers of cerebellar cortex. Expression in midbrain was minimal, and generally limited to isolated neurons and astrocytes in the cerebral peduncles. GFP immunoreactivity (-ir) in thalamus was most prominent in medial geniculate nucleus, and otherwise limited to posterior nuclei of the dorsal and lateral margins. Labeling was also observed in neurons and astrocytes of the hippocampal formation and amygdaloid complex. In the hippocampal formation, GFP-ir was found in neuronal cell bodies of the rostral ventral portion, but was largely restricted to fiber-like staining in the molecular layer of dentate gyrus and stratum lacunosum-moleculare of the rostral dorsal region. GFP-ir was seen in neurons and astroglia throughout caudal cortex, whereas in rostral regions of neocortex it was limited to isolated neurons and non-neuronal cells. Labeling was also present in olfactory bulb. These results demonstrate that intrathecal delivery of AAV5 vector leads to transgene expression in discrete CNS regions throughout the rostro-caudal extent of the neuraxis. A caudal-to-rostral gradient of decreasing GFP-ir was present in choroid plexus and Purkinje cells, suggesting that spread of virus through cerebrospinal fluid plays a role in the resulting transduction pattern. Other factors contributing to the observed expression pattern likely include variations in cell-surface receptors and inter-parenchymal space. PMID:25147505

  3. BTK gene targeting by homologous recombination using a helper-dependent adenovirus/adeno-associated virus hybrid vector.

    PubMed

    Yamamoto, H; Ishimura, M; Ochiai, M; Takada, H; Kusuhara, K; Nakatsu, Y; Tsuzuki, T; Mitani, K; Hara, T

    2016-02-01

    X-linked agammaglobulinemia (XLA) is one of the most common humoral immunodeficiencies, which is caused by mutations in Bruton's tyrosine kinase (BTK) gene. To examine the possibility of using gene therapy for XLA, we constructed a helper-dependent adenovirus/adeno-associated virus BTK targeting vector (HD-Ad.AAV BTK vector) composed of a genomic sequence containing BTK exons 6-19 and a green fluorescence protein-hygromycin cassette driven by a cytomegalovirus promoter. We first used NALM-6, a human male pre-B acute lymphoblastic leukemia cell line, as a recipient to measure the efficiency of gene targeting by homologous recombination. We identified 10 clones with the homologous recombination of the BTK gene among 107 hygromycin-resistant stable clones isolated from two independent experiments. We next used cord blood CD34⁺ cells as the recipient cells for the gene targeting. We isolated colonies grown in medium containing cytokines and hygromycin. We found that the targeting of the BTK gene occurred in four of the 755 hygromycin-resistant colonies. Importantly, the gene targeting was also observed in CD19⁺ lymphoid progenitor cells that were differentiated from the homologous recombinant CD34⁺ cells during growth in selection media. Our study shows the potential for the BTK gene therapy using the HD-Ad.AAV BTK vector via homologous recombination in hematopoietic stem cells. PMID:26280081

  4. Light-Activated Nuclear Translocation of Adeno-Associated Virus Nanoparticles Using Phytochrome B for Enhanced, Tunable, and Spatially Programmable Gene Delivery.

    PubMed

    Gomez, Eric J; Gerhardt, Karl; Judd, Justin; Tabor, Jeffrey J; Suh, Junghae

    2016-01-26

    Gene delivery vectors that are activated by external stimuli may allow improved control over the location and the degree of gene expression in target populations of cells. Light is an attractive stimulus because it does not cross-react with cellular signaling networks, has negligible toxicity, is noninvasive, and can be applied in space and time with unparalleled precision. We used the previously engineered red (R)/far-red (FR) light-switchable protein phytochrome B (PhyB) and its R light dependent interaction partner phytochrome interacting factor 6 (PIF6) from Arabidopsis thaliana to engineer an adeno-associated virus (AAV) platform whose gene delivery efficiency is controlled by light. Upon exposure to R light, AAV engineered to display PIF6 motifs on the capsid bind to PhyB tagged with a nuclear localization sequence (NLS), resulting in significantly increased translocation of viruses into the host cell nucleus and overall gene delivery efficiency. By modulating the ratio of R to FR light, the gene delivery efficiency can be tuned to as little as 35% or over 600% of the unengineered AAV. We also demonstrate spatial control of gene delivery using projected patterns of codelivered R and FR light. Overall, our successful use of light-switchable proteins in virus capsid engineering extends these important optogenetic tools into the adjacent realm of nucleic acid delivery and enables enhanced, tunable, and spatially controllable regulation of viral gene delivery. Our current light-triggered viral gene delivery prototype may be broadly useful for genetic manipulation of cells ex vivo or in vivo in transgenic model organisms, with the ultimate prospect of achieving dose- and site-specific gene expression profiles for either therapeutic (e.g., regenerative medicine) or fundamental discovery research efforts. PMID:26618393

  5. Adeno-associated virus mediated gene transfer of Shepherdin inhibits gallbladder carcinoma growth in vitro and in vivo.

    PubMed

    Zhu, Aijun; Ren, Yu; Wang, Ning; Jin, Qiuyue; Zhang, Dongchang; Yang, Guangxiao; Wang, Quanying

    2015-11-01

    Gene therapy, a significantly crucial strategy for treatment of malignancies, has been gradually accepted in recent years. However, this therapeutic approach has being facing great challenges concerning problems which include complicated development of cancer with multiple gene control, effective target shortage, low efficiency of gene transferring and safety of the vector delivery system. Shepherdin, a novel peptidomimetic molecule designed from Lys-79 to Leu-87 of survivin, has been identified as a tumor suppressor with the function that can not only competitively interfere with the interaction between survivin and Hsp90 (heat shock protein-90) leading to the degradation of survivin to anti-tumor, but also competitively target the ATP-dependent binding pocket of Hsp90 resulting in the dysfunction of Hsp90 chaperone to cell apoptosis via a mitochondrial dependent or independent pathway. In the present study, we designed and constructed a recombinant Adeno-associated virus (rAAV) loading fusion gene NT4-TAT-6His-Shepherdin. The expression of Shepherdin in gallbladder carcinoma (GBC) cells was detected and its strong inhibitory effects against GBC growth were evaluated after AAV mediated gene transfer of Shepherdin into GBC cells and xenograft tumors. MTT assay and flow cytometric analysis demonstrated that rAAV containing Shepherdin gene could significantly inhibit the growth of GBC and this effect was closely associated with apoptosis. These results indicated that rAAV-NT4-TAT-6His-Shepherdin may be considered a novel therapeutic strategy in the gene therapy for gallbladder carcinoma. PMID:26143116

  6. Regulation of adeno-associated virus gene expression in 293 cells: control of mRNA abundance and translation

    SciTech Connect

    Trempe, J.P.; Carter, B.J.

    1988-01-01

    The authors studied the effects of the adeno-associated virus (AAV) rep gene on the control of gene expression from the AAV p/sub 40/ promoter in 293 cells in the absence of an adenovirus coinfection. AAV vectors containing the chloramphenicol acetyltransferase (cat) gene were used to measure the levels of cat expression and steady-state mRNA from p/sub 40/. When the rep gene was present in cis or in trans, cat expression from p/sub 40/ was decreased 3- to 10-fold, but there was a 2- to 10-fold increase in the level of p/sub 40/ mRNA. Conversely, cat expression increased and the p/sub 40/ mRNA level decreased in the absence of the rep gene. Both wild-type and carboxyl-terminal truncated Rep proteins were capable of eliciting both effects. These data suggest two roles for the pleiotropic AAV rep gene: as a translational inhibitor and as a positive regulator of p/sub 40/ mRNA levels. They also provide additional evidence for a cis-acting negative regulatory region which decreases RNA from the AAV p/sub 5/ promoter in a fashion independent of rep.

  7. [Adeno-associated virus mediated T-bet gene transfer into SGC-7901 cell to regulate IFN-gamma production].

    PubMed

    Qiu, Gufeng; Wang, Suoying; Wang, Shengjun; Shao, Qixiang; Ma, Jie; Yang, Ming; Xu, Xiaopeng; Mao, Chaoming; Su, Zhaoliang; Huang, Xinxiang; Xu, Huaxi

    2009-06-01

    In order to investigate the effect of T-bet on malignant cells, we selected SGC-7901, a kind of human gastric carcinoma cell line, and used gene clone technique and adeno-associated virus (AAV) packing technology, thus obtaining a recombinant rAAV-eGFP-T-bet and T-bet gene-transfected SGC-7901 cells. Then the function of T-bet gene-infected SGC-7901 cells was researched by detecting the levels of IFN-gamma and T-bet production. The results showed: (1) It was verified that rAAV-T-bet's packing was completed; (2) After SGC-7901 cells was transfected by rAAV-eGFP-T-bet, a green fluorescence was found in about 30%-40% SGC-7901s, and the gene of 1670 bp (T-bet) and 388 bp (IFN-gamma) were generated from SGC-7901s cells; (3) The proteins of IFN-gamma and T-bet secreted by SGC-7901 cells were also detected. These reveal that SGC-7901 cell is efficiently infected by rAAV encoding T-bet, which can induce transfected cells to secret IFN-gamma. It may be useful in the researches on cancer immune therapy of transfecting T-bet gene. PMID:19634682

  8. Binding of adeno-associated virus type 5 to 2,3-linked sialic acid is required for gene transfer.

    PubMed

    Walters, R W; Yi, S M; Keshavjee, S; Brown, K E; Welsh, M J; Chiorini, J A; Zabner, J

    2001-06-01

    Recombinant adeno-associated viruses (AAV) are promising gene therapy vectors. Whereas AAV serotype 2-mediated gene transfer to muscle has partially replaced factor IX deficiency in hemophilia patients, its ability to mediate gene transfer to the lungs for cystic fibrosis is hindered by lack of apical receptors. However, AAV serotype 5 infects human airway epithelia from the lumenal surface. We found that in contrast to AAV2, the apical membrane of airway epithelia contains abundant high affinity receptors for AAV5. Binding and gene transfer with AAV5 was abolished by genetic or enzymatic removal of sialic acid from the cell surface. Furthermore, binding and gene transfer to airway epithelia was competed by lectins that specifically bind 2,3-linked sialic acid. These observations suggest that 2,3-linked sialic acid is either a receptor for AAV5 or it is a necessary component of a receptor complex. Further elucidation of the receptor for this virus should enhance understanding of parvovirus biology and expand the therapeutic targets for AAV vectors. PMID:11262413

  9. Impact of Pre-Existing Immunity on Gene Transfer to Nonhuman Primate Liver with Adeno-Associated Virus 8 Vectors

    PubMed Central

    Wang, Lili; Calcedo, Roberto; Bell, Peter; Lin, Jianping; Grant, Rebecca L; Siegel, Don L

    2011-01-01

    Abstract Vectors based on the primate-derived adeno-associated virus serotype 8 (AAV8) are being evaluated in preclinical and clinical models. Natural infections with related AAVs activate memory B cells that produce antibodies capable of modulating the efficacy and safety of the vector. We have evaluated the biology of AAV8 gene transfer in macaque liver, with a focus on assessing the impact of pre-existing humoral immunity. Twenty-one macaques with various levels of AAV neutralizing antibody (NAb) were injected intravenously with AAV8 vector expressing green fluorescent protein. Pre-existing antibody titers in excess of 1:10 substantially diminished hepatocyte transduction that, in the absence of NAbs, was highly efficient. Vector-specific NAb diminished liver deposition of genomes and unexpectedly increased genome distribution to the spleen. The majority of animals showed high-level and stable sequestration of vector capsid protein by follicular dendritic cells of splenic germinal centers. These studies illustrate how natural immunity to a virus that is related to a vector can impact the efficacy and potential safety of in vivo gene therapy. We propose to use the in vitro transduction inhibition assay to evaluate research subjects before gene therapy and to preclude from systemic AAV8 trials those that have titers in excess of 1:10. PMID:21476868

  10. Adeno-associated virus vector-mediated minidystrophin gene therapy improves dystrophic muscle contractile function in mdx mice.

    PubMed

    Watchko, Jon; O'Day, Terry; Wang, Bing; Zhou, Liqiao; Tang, Ying; Li, Juan; Xiao, Xiao

    2002-08-10

    Duchenne muscular dystrophy (DMD) is the most common disabling and lethal genetic muscle disorder, afflicting 1 of every 3500 males. Patients with DMD experience progressive muscle degeneration and weakness and succumb to respiratory or cardiac failure by their early twenties. No treatment is currently available for DMD. Mutations in the dystrophin gene result in lack of a functional dystrophin protein in striated muscle, which induces instability in the muscle cell membrane leading to persistent muscle injury after contraction. We have previously created novel minidystrophin genes and demonstrated that adeno-associated virus (AAV)-mediated intramuscular delivery of the minigenes effectively ameliorated mdx dystrophic histopathology and led to normal cell membrane integrity for more than 1 year. In this paper, we investigated whether AAV-minidystrophin could also improve mdx muscle contractile function. Two-month-old adult male mdx mice, with established muscular dystrophy, were given a single-dose injection of an AAV-minidystrophin vector in the tibialis anterior (TA) muscle of one leg, with the untreated contralateral leg used as a control. The treated TA muscle showed both (1) a significant increase in isometric force generation and (2) a significant increase in resistance to lengthening activation-induced muscle force decrements. We conclude that AAV-minidystrophin gene treatment is effective in improving mdx muscle contractile function. PMID:12215266

  11. Rescue of skeletal muscles of gamma-sarcoglycan-deficient mice with adeno-associated virus-mediated gene transfer.

    PubMed

    Cordier, L; Hack, A A; Scott, M O; Barton-Davis, E R; Gao, G; Wilson, J M; McNally, E M; Sweeney, H L

    2000-02-01

    In humans, a subset of cases of Limb-girdle muscular dystrophy (LGMD) arise from mutations in the genes encoding one of the sarcoglycan (alpha, beta, gamma, or delta) subunits of the dystrophin-glycoprotein complex. While adeno-associated virus (AAV) is a potential gene therapy vector for these dystrophies, it is unclear if AAV can be used if a diseased muscle is undergoing rapid degeneration and necrosis. The skeletal muscles of mice lacking gamma-sarcoglycan (gsg-/- mice) differ from the animal models that have been evaluated to date in that the severity of the skeletal muscle pathology is much greater and more representative of that of humans with muscular dystrophy. Following direct muscle injection of a recombinant AAV [in which human gamma-sarcoglycan expression is driven by a truncated muscle creatine kinase (MCK) promoter/enhancer], we observed significant numbers of muscle fibers expressing gamma-sarcoglycan and an overall improvement of the histologic pattern of dystrophy. However, these results could be achieved only if injections into the muscle were prior to the development of significant fibrosis in the muscle. The results presented in this report show promise for AAV gene therapy for LGMD, but underscore the need for intervention early in the time course of the disease process. PMID:10933922

  12. Adeno-associated virus 9 mediated FKRP gene therapy restores functional glycosylation of α-dystroglycan and improves muscle functions.

    PubMed

    Xu, Lei; Lu, Pei Juan; Wang, Chi-Hsien; Keramaris, Elizabeth; Qiao, Chunping; Xiao, Bin; Blake, Derek J; Xiao, Xiao; Lu, Qi Long

    2013-10-01

    Mutations in the FKRP gene are associated with a wide range of muscular dystrophies from mild limb-girdle muscular dystrophy (LGMD) 2I to severe Walker-Warburg syndrome and muscle-eye-brain disease. The characteristic biochemical feature of these diseases is the hypoglycosylation of α-dystroglycan (α-DG). Currently there is no effective treatment available. In this study, we examined the adeno-associated virus serotype 9 vector (AAV9)-mediated gene therapy in the FKRP mutant mouse model with a proline to leucine missense mutation (P448L). Our results showed that intraperitoneal administration of AAV9-FKRP resulted in systemic FKRP expression in all striated muscles examined with the highest levels in cardiac muscle. Consistent with our previous observations, FKRP protein is localized in the Golgi apparatus in myofibers. Expression of FKRP consequently restored functional glycosylation of α-DG in the skeletal and cardiac muscles. Significant improvement in dystrophic pathology, serum creatine kinase levels and muscle function was observed. Only limited FKRP transgene expression was detected in kidney and liver with no detectable toxicity. Our results provided evidence for the utility of AAV-mediated gene replacement therapy for FKRP-related muscular dystrophies. PMID:23817215

  13. Partial correction of the CFTR-dependent ABPA mouse model with recombinant adeno-associated virus gene transfer of truncated CFTR gene.

    PubMed

    Mueller, Christian; Torrez, Daniel; Braag, Sofia; Martino, Ashley; Clarke, Tracy; Campbell-Thompson, Martha; Flotte, Terence R

    2008-01-01

    Recently, we have developed a model of airway inflammation in a CFTR knockout mouse utilizing Aspergillus fumigatus crude protein extract (Af-cpe) to mimic allergic bronchopulmonary aspergillosis (ABPA) 1, an unusual IgE-mediated hypersensitivity syndrome seen in up to 15% of cystic fibrosis (CF) patients and rarely elsewhere. We hypothesized that replacement of CFTR via targeted gene delivery to airway epithelium would correct aberrant epithelial cytokine signaling and ameliorate the ABPA phenotype in CFTR-deficient (CFTR 489X - /-, FABP-hCFTR + / +) mice. CFTR knockout mice underwent intra-tracheal (IT) delivery of recombinant adeno-associated virus serotype 5 (rAAV5Delta-264CFTR) or rAAV5-GFP at 2.58 x 10(12) viral genomes/mouse. All mice were then sensitized with two serial injections (200 microg) of crude Af antigen via the intra-peritoneal (IP) route. Untreated mice were sensitized without virus exposure. Challenges were performed 2 weeks after final sensitization, using a 0.25% solution containing Aspergillus fumigatus crude protein extract delivered by inhalation on three consecutive days. The rAAV5Delta-264CFTR-treated mice had lower total serum IgE levels (172513 ng/ml +/- 1312) than rAAV5-GFP controls (26 892 ng/ml +/- 3715) (p = 0.037) and non-treated, sensitized controls (24 816 +/- 4219 ng/ml). Serum IgG1 levels also were lower in mice receiving the CFTR vector. Interestingly, splenocytes from rAAV5Delta-264CFTR-treated mice secreted less IL-13, INFg, TNFa, RANTES and GM-CSF after ConA stimulation. Gene therapy with rAAV5Delta-264CFTR attenuated the hyper-IgE response in this reproducible CF mouse model of ABPA, with systemic effects also evident in the cytokine response of stimulated splenocytes. PMID:18023072

  14. Comparative Analysis of Cesium Chloride- and Iodixanol-Based Purification of Recombinant Adeno-Associated Viral Vectors for Preclinical Applications.

    PubMed

    Strobel, Benjamin; Miller, Felix D; Rist, Wolfgang; Lamla, Thorsten

    2015-08-01

    Cesium chloride (CsCl)- and iodixanol-based density gradients represent the core step in most protocols for serotype-independent adeno-associated virus (AAV) purification established to date. However, despite controversial reports about the purity and bioactivity of AAV vectors derived from each of these protocols, systematic comparisons of state-of-the-art variants of these methods are sparse. To define exact conditions for such a comparison, we first fractionated both gradients to analyze the distribution of intact, bioactive AAVs and contaminants, respectively. Moreover, we tested four different polishing methods (ultrafiltration, size-exclusion chromatography, hollow-fiber tangential flow filtration, and polyethylene glycol precipitation) implemented after the iodixanol gradient for their ability to deplete iodixanol and protein contaminations. Last, we conducted a side-by-side comparison of the CsCl and iodixanol/ultrafiltration protocol. Our results demonstrate that iodixanol-purified AAV preparations show higher vector purity but harbor more (∼20%) empty particles as compared with CsCl-purified vectors (<1%). Using mass spectrometry, we analyzed prominent protein impurities in the AAV vector product, thereby identifying known and new, possibly AAV-interacting proteins as major contaminants. Thus, our study not only provides a helpful guide for the many laboratories entering the AAV field, but also builds a basis for further investigation of cellular processes involved in AAV vector assembly and trafficking. PMID:26222983

  15. Comparative Analysis of Cesium Chloride- and Iodixanol-Based Purification of Recombinant Adeno-Associated Viral Vectors for Preclinical Applications

    PubMed Central

    Strobel, Benjamin; Miller, Felix D.; Rist, Wolfgang; Lamla, Thorsten

    2015-01-01

    Cesium chloride (CsCl)- and iodixanol-based density gradients represent the core step in most protocols for serotype-independent adeno-associated virus (AAV) purification established to date. However, despite controversial reports about the purity and bioactivity of AAV vectors derived from each of these protocols, systematic comparisons of state-of-the-art variants of these methods are sparse. To define exact conditions for such a comparison, we first fractionated both gradients to analyze the distribution of intact, bioactive AAVs and contaminants, respectively. Moreover, we tested four different polishing methods (ultrafiltration, size-exclusion chromatography, hollow-fiber tangential flow filtration, and polyethylene glycol precipitation) implemented after the iodixanol gradient for their ability to deplete iodixanol and protein contaminations. Last, we conducted a side-by-side comparison of the CsCl and iodixanol/ultrafiltration protocol. Our results demonstrate that iodixanol-purified AAV preparations show higher vector purity but harbor more (∼20%) empty particles as compared with CsCl-purified vectors (<1%). Using mass spectrometry, we analyzed prominent protein impurities in the AAV vector product, thereby identifying known and new, possibly AAV-interacting proteins as major contaminants. Thus, our study not only provides a helpful guide for the many laboratories entering the AAV field, but also builds a basis for further investigation of cellular processes involved in AAV vector assembly and trafficking. PMID:26222983

  16. ENHANCED GENE DELIVERY IN PORCINE VASCULATURE TISSUE FOLLOWING INCORPORATION OF ADENO-ASSOCIATED VIRUS NANOPARTICLES INTO POROUS SILICON MICROPARTICLES

    PubMed Central

    McConnell, Kellie I.; Rhudy, Jessica; Yokoi, Kenji; Gu, Jianhua; Mack, Aaron; Suh, Junghae; La Francesca, Saverio; Sakamoto, Jason; Serda, Rita E.

    2014-01-01

    There is an unmet clinical need to increase lung transplant successes, patient satisfaction and to improve mortality rates. We offer the development of a nanovector-based solution that will reduce the incidence of lung ischemic reperfusion injury (IRI) leading to graft organ failure through the successful ex vivo treatment of the lung prior to transplantation. The innovation is in the integrated application of our novel porous silicon (pSi) microparticles carrying adeno-associated virus (AAV) nanoparticles, and the use of our ex vivo lung perfusion/ventilation system for the modulation of pro-inflammatory cytokines initiated by ischemic pulmonary conditions prior to organ transplant that often lead to complications. Gene delivery of anti-inflammatory agents to combat the inflammatory cascade may be a promising approach to prevent IRI following lung transplantation. The rationale for the device is that the microparticle will deliver a large payload of virus to cells and serve to protect the AAV from immune recognition. The microparticle-nanoparticle hybrid device was tested both in vitro on cell monolayers and ex vivo using either porcine venous tissue or a pig lung transplantation model, which recapitulates pulmonary IRI that occurs clinically post-transplantation. Remarkably, loading AAV vectors into pSi microparticles increases gene delivery to otherwise non-permissive endothelial cells. PMID:25180449

  17. Biochemical Correction of Very Long–chain Acyl-CoA Dehydrogenase Deficiency Following Adeno-associated Virus Gene Therapy

    PubMed Central

    Merritt, J. Lawrence; Nguyen, Tien; Daniels, Jan; Matern, Dietrich; Schowalter, David B.

    2009-01-01

    We report the development of a gene replacement strategy for very long–chain acyl-CoA dehydrogenase (VLCAD) deficiency. VLCAD is a mitochondrial enzyme involved in fatty acid β-oxidation, a key step in energy production during times of fasting or stress. Deficiency of VLCAD classically presents as hepatic dysfunction, hypoglycemia, cardiomyopathy, rhabdomyolysis, and/or sudden death. While dietary therapy for VLCAD deficiency has proven beneficial in preventing some symptoms, a risk of metabolic catastrophic decompensation remains throughout life during times of increased energy demand. We designed a recombinant adeno-associated virus (AAV) expressing the human VLCAD gene (AAV8-hVLCAD). To demonstrate its in vivo activity, AAV8-hVLCAD was administered via the tail vein to VLCAD-knockout mice. A reduction in accumulated serum long-chain acylcarnitines and increased fasting tolerance judged on blood glucose concentrations were observed as of 11 days postinjections through >100 days. Western analysis of liver, skeletal muscle, and heart extracts using PEP1 anti-hVLCAD antibody revealed short-term hVLCAD expression in the liver and muscle and longer-term expression in heart. This demonstrates the ability of human VLCAD to correct the biochemical phenotype of VLCAD-deficient mice. PMID:19156135

  18. A shortened adeno-associated virus expression cassette for CFTR gene transfer to cystic fibrosis airway epithelia.

    PubMed

    Ostedgaard, Lynda S; Rokhlina, Tatiana; Karp, Philip H; Lashmit, Philip; Afione, Sandra; Schmidt, Michael; Zabner, Joseph; Stinski, Mark F; Chiorini, Jay A; Welsh, Michael J

    2005-02-22

    Adeno-associated viruses (AAVs) such as AAV5 that transduce airway epithelia from the apical surface are attractive vectors for gene transfer in cystic fibrosis (CF). However, their utility in CF has been limited because packaging of the insert becomes inefficient when its length exceeds approximately 4,900-5,000 bp. To partially circumvent this size constraint, we previously developed a CF transmembrane conductance regulator (CFTR) transgene that deleted a portion of the R domain (CFTRDeltaR). In this study, we focused on shortening the other elements in the AAV expression cassette. We found that portions of the CMV immediate/early (CMVie) enhancer/promoter could be deleted without abolishing activity. We also tested various intervening sequences, poly(A) signals, and an intron to develop an expression cassette that meets the size restrictions imposed by AAV. We then packaged these shortened elements with the CFTRDeltaR transgene into AAV5 and applied them to the apical surface of differentiated CF airway epithelia. Two to 4 weeks later, the AAV5 vectors partially corrected the CF Cl(-) transport defect. These results demonstrate that a single AAV vector can complement the CF defect in differentiated airway epithelia and thereby further the development of effective CF gene transfer. PMID:15703296

  19. A shortened adeno-associated virus expression cassette for CFTR gene transfer to cystic fibrosis airway epithelia

    PubMed Central

    Ostedgaard, Lynda S.; Rokhlina, Tatiana; Karp, Philip H.; Lashmit, Philip; Afione, Sandra; Schmidt, Michael; Zabner, Joseph; Stinski, Mark F.; Chiorini, Jay A.; Welsh, Michael J.

    2005-01-01

    Adeno-associated viruses (AAVs) such as AAV5 that transduce airway epithelia from the apical surface are attractive vectors for gene transfer in cystic fibrosis (CF). However, their utility in CF has been limited because packaging of the insert becomes inefficient when its length exceeds ≈4,900–5,000 bp. To partially circumvent this size constraint, we previously developed a CF transmembrane conductance regulator (CFTR) transgene that deleted a portion of the R domain (CFTRΔR). In this study, we focused on shortening the other elements in the AAV expression cassette. We found that portions of the CMV immediate/early (CMVie) enhancer/promoter could be deleted without abolishing activity. We also tested various intervening sequences, poly(A) signals, and an intron to develop an expression cassette that meets the size restrictions imposed by AAV. We then packaged these shortened elements with the CFTRΔR transgene into AAV5 and applied them to the apical surface of differentiated CF airway epithelia. Two to 4 weeks later, the AAV5 vectors partially corrected the CF Cl– transport defect. These results demonstrate that a single AAV vector can complement the CF defect in differentiated airway epithelia and thereby further the development of effective CF gene transfer. PMID:15703296

  20. A next step in adeno-associated virus-mediated gene therapy for neurological diseases: regulation and targeting

    PubMed Central

    Chtarto, Abdelwahed; Bockstael, Olivier; Tshibangu, Terence; Dewitte, Olivier; Levivier, Marc; Tenenbaum, Liliane

    2013-01-01

    Recombinant adeno-associated virus (rAAV) vectors mediating long term transgene expression are excellent gene therapy tools for chronic neurological diseases. While rAAV2 was the first serotype tested in the clinics, more efficient vectors derived from the rh10 serotype are currently being evaluated and other serotypes are likely to be tested in the near future. In addition, aside from the currently used stereotaxy-guided intraparenchymal delivery, new techniques for global brain transduction (by intravenous or intra-cerebrospinal injections) are very promising. Various strategies for therapeutic gene delivery to the central nervous system have been explored in human clinical trials in the past decade. Canavan disease, a genetic disease caused by an enzymatic deficiency, was the first to be approved. Three gene transfer paradigms for Parkinson's disease have been explored: converting L-dopa into dopamine through AADC gene delivery in the putamen; synthesizing GABA through GAD gene delivery in the overactive subthalamic nucleus and providing neurotrophic support through neurturin gene delivery in the nigro-striatal pathway. These pioneer clinical trials demonstrated the safety and tolerability of rAAV delivery in the human brain at moderate doses. Therapeutic effects however, were modest, emphasizing the need for higher doses of the therapeutic transgene product which could be achieved using more efficient vectors or expression cassettes. This will require re-addressing pharmacological aspects, with attention to which cases require either localized and cell-type specific expression or efficient brain-wide transgene expression, and when it is necessary to modulate or terminate the administration of transgene product. The ongoing development of targeted and regulated rAAV vectors is described. PMID:23331189

  1. Mutants at the 2-Fold Interface of Adeno-associated Virus Type 2 (AAV2) Structural Proteins Suggest a Role in Viral Transcription for AAV Capsids

    PubMed Central

    Aydemir, Fikret; Salganik, Maxim; Resztak, Justyna; Singh, Jasbir; Bennett, Antonette; Agbandje-McKenna, Mavis

    2016-01-01

    ABSTRACT We previously reported that an amino acid substitution, Y704A, near the 2-fold interface of adeno-associated virus (AAV) was defective for transcription of the packaged genome (M. Salganik, F. Aydemir, H. J. Nam, R. McKenna, M. Agbandje-McKenna, and N. Muzyczka, J Virol 88:1071–1079, 2013, doi: http://dx.doi.org/10.1128/JVI.02093-13). In this report, we have characterized the defect in 6 additional capsid mutants located in a region ∼30 Å in diameter on the surface of the AAV type 2 (AAV2) capsid near the 2-fold interface. These mutants, which are highly conserved among primate serotypes, displayed a severe defect (3 to 6 logs) in infectivity. All of the mutants accumulated significant levels of uncoated DNA in the nucleus, but none of the mutants were able to accumulate significant amounts of genomic mRNA postinfection. In addition, wild-type (wt) capsids that were bound to the conformational antibody A20, which is known to bind the capsid surface in the region of the mutants, were also defective for transcription. In all cases, the mutant virus particles, as well as the antibody-bound wild-type capsids, were able to enter the cell, travel to the nucleus, uncoat, and synthesize a second strand but were unable to transcribe their genomes. Taken together, the phenotype of these mutants provides compelling evidence that the AAV capsid plays a role in the transcription of its genome, and the mutants map this functional region on the surface of the capsid near the 2-fold interface. This appears to be the first example of a viral structural protein that is also involved in the transcription of the viral genome that it delivers to the nucleus. IMPORTANCE Many viruses package enzymes within their capsids that assist in expressing their genomes postinfection, e.g., retroviruses. A number of nonenveloped viruses, including AAV, carry proteases that are needed for capsid maturation or for capsid modification during infection. We describe here what appears to

  2. TrkB gene therapy by adeno-associated virus enhances recovery after cervical spinal cord injury.

    PubMed

    Martínez-Gálvez, Gabriel; Zambrano, Juan M; Diaz Soto, Juan C; Zhan, Wen-Zhi; Gransee, Heather M; Sieck, Gary C; Mantilla, Carlos B

    2016-02-01

    Unilateral cervical spinal cord hemisection at C2 (C2SH) interrupts descending bulbospinal inputs to phrenic motoneurons, paralyzing the diaphragm muscle. Recovery after C2SH is enhanced by brain derived neurotrophic factor (BDNF) signaling via the tropomyosin-related kinase subtype B (TrkB) receptor in phrenic motoneurons. The role for gene therapy using adeno-associated virus (AAV)-mediated delivery of TrkB to phrenic motoneurons is not known. The present study determined the therapeutic efficacy of intrapleural delivery of AAV7 encoding for full-length TrkB (AAV-TrkB) to phrenic motoneurons 3 days post-C2SH. Diaphragm EMG was recorded chronically in male rats (n=26) up to 21 days post-C2SH. Absent ipsilateral diaphragm EMG activity was verified 3 days post-C2SH. A greater proportion of animals displayed recovery of ipsilateral diaphragm EMG activity during eupnea by 14 and 21 days post-SH after AAV-TrkB (10/15) compared to AAV-GFP treatment (2/11; p=0.031). Diaphragm EMG amplitude increased over time post-C2SH (p<0.001), and by 14 days post-C2SH, AAV-TrkB treated animals displaying recovery achieved 48% of the pre-injury values compared to 27% in AAV-GFP treated animals. Phrenic motoneuron mRNA expression of glutamatergic AMPA and NMDA receptors revealed a significant, positive correlation (r(2)=0.82), with increased motoneuron NMDA expression evident in animals treated with AAV-TrkB and that displayed recovery after C2SH. Overall, gene therapy using intrapleural delivery of AAV-TrkB to phrenic motoneurons is sufficient to promote recovery of diaphragm activity, adding a novel potential intervention that can be administered after upper cervical spinal cord injury to improve impaired respiratory function. PMID:26607912

  3. Liver-Specific Allergen Gene Transfer by Adeno-Associated Virus Suppresses Allergic Airway Inflammation in Mice.

    PubMed

    Chan, Cheng-Chi; Lai, Chin-Wen; Wu, Chia-Jen; Chen, Li-Chen; Tao, Mi-Hua; Kuo, Ming-Ling

    2016-08-01

    Allergic airway inflammation driven by T helper 2 (Th2)-type immunity is characterized by airway hyperresponsiveness, eosinophilic infiltration, and elevated IgE production. Various novel strategies for managing asthma have been explored, such as DNA vaccines, T-cell peptides, and allergen-specific immunotherapy. A principal goal of most immunotherapeutic approaches is active and long-term allergen-specific tolerance. Liver-specific gene transfer using adeno-associated virus (AAV) has been shown to favorably induce tolerogenic responses to therapeutic products in various experimental models. AAV8 has strong liver tropism and induces immune tolerance in mice. The present study aimed to determine whether hepatocyte-specific allergen expression by pseudotyped AAV2/8 alleviates asthmatic symptoms in ovalbumin (OVA)-sensitized mice. Mice were intravenously injected with AAV2/8 vector carrying membrane-bound OVA transgene under transcriptional control of a hepatocyte-specific alpha 1 antitrypsin promoter (AAV2/8-OVA) and then sensitized with OVA. AAV2/8-OVA specifically transduced the OVA transgene in the liver. Airway hyperresponsiveness, eosinophilia, mucus hypersecretion, and Th2 cytokines were significantly suppressed in both the lungs and secondary lymphoid organs of asthmatic mice infected with AAV2/8-OVA. Significant reduction of OVA-specific antibodies was detected in the bronchoalveolar lavage fluid from AAV2/8-OVA-treated mice. Moreover, AAV2/8-OVA treatment prominently promoted the expression of Foxp3, IL-10, and TGF-β in the liver. Enhanced Foxp3 expression was also detected in the lungs of asthmatic mice after AAV2/8-OVA treatment. Taken together, these results suggest that the induction of immune tolerance by hepatic AAV gene transfer may be beneficial for modulating allergic asthma. PMID:27178525

  4. Early, sustained efficacy of adeno-associated virus vector-mediated gene therapy in glycogen storage disease type Ia.

    PubMed

    Koeberl, D D; Sun, B D; Damodaran, T V; Brown, T; Millington, D S; Benjamin, D K; Bird, A; Schneider, A; Hillman, S; Jackson, M; Beaty, R M; Chen, Y T

    2006-09-01

    The deficiency of glucose-6-phosphatase (G6Pase) underlies life-threatening hypoglycemia and growth retardation in glycogen storage disease type Ia (GSD-Ia). An adeno-associated virus (AAV) vector encoding G6Pase was pseudotyped as AAV8 and administered to 2-week-old GSD-Ia mice (n = 9). Median survival was prolonged to 7 months following vector administration, in contrast to untreated GSD-Ia mice that survived for only 2 weeks. Although GSD-Ia mice were initially growth-retarded, treated mice increased fourfold in weight to normal size. Blood glucose was partially corrected by 2 weeks following treatment, whereas blood cholesterol normalized. Glucose-6-phosphatase activity was partially corrected to 25% of the normal level at 7 months of age in treated mice, and blood glucose during fasting remained lower in treated, affected mice than in normal mice. Glycogen storage was partially corrected in the liver by 2 weeks following treatment, but reaccumulated to pre-treatment levels by 7 months old (m.o.). Vector genome DNA decreased between 3 days and 3 weeks in the liver following vector administration, mainly through the loss of single-stranded genomes; however, double-stranded vector genomes were more stable. Although CD8+ lymphocytic infiltrates were present in the liver, partial biochemical correction was sustained at 7 m.o. The development of efficacious AAV vector-mediated gene therapy could significantly reduce the impact of long-term complications in GSD-Ia, including hypoglycemia, hyperlipidemia and growth failure. PMID:16672983

  5. Restriction Factors Against Recombinant Adeno-associated Virus Vectormediated Gene Transfer in Dystrophin-deficient Muscles.

    PubMed

    Dupont, Jean-Baptiste

    2016-01-01

    Despite the unprecedented beneficial effects of rAAV gene therapy in animal models of Duchenne muscular dystrophy (DMD), the need to inject large amounts of vector in vivo to improve phenotype raises obvious biosafety concerns. While rAAV vectors generally exhibit a good safety profile, specific pathological phenotypes such as those observed in dystrophin-deficient muscles may promote immunotoxic/genotoxic effects. Increasing the therapeutic index of rAAV in DMD muscles by reducing the effective dose could be a pivotal means of ensuring efficient clinical translation. This requires a comprehensive understanding of the rAAV transduction process, which is almost always studied in non-pathological tissues or in vitro. In this review, we focus on the molecular fate of rAAV after injection, and how the individual stages of transduction could be affected in the context of DMD. PMID:27121109

  6. Longitudinal follow-up and characterization of a robust rat model for Parkinson's disease based on overexpression of alpha-synuclein with adeno-associated viral vectors.

    PubMed

    Van der Perren, Anke; Toelen, Jaan; Casteels, Cindy; Macchi, Francesca; Van Rompuy, Anne-Sophie; Sarre, Sophie; Casadei, Nicolas; Nuber, Silke; Himmelreich, Uwe; Osorio Garcia, Maria Isabel; Michotte, Yvette; D'Hooge, Rudi; Bormans, Guy; Van Laere, Koen; Gijsbers, Rik; Van den Haute, Chris; Debyser, Zeger; Baekelandt, Veerle

    2015-03-01

    Testing of new therapeutic strategies for Parkinson's disease (PD) is currently hampered by the lack of relevant and reproducible animal models. Here, we developed a robust rat model for PD by injection of adeno-associated viral vectors (rAAV2/7) encoding α-synuclein into the substantia nigra, resulting in reproducible nigrostriatal pathology and behavioral deficits in a 4-week time period. Progressive dopaminergic dysfunction was corroborated by histopathologic and biochemical analysis, motor behavior testing and in vivo microdialysis. L-DOPA treatment was found to reverse the behavioral phenotype. Non-invasive positron emission tomography imaging and magnetic resonance spectroscopy allowed longitudinal monitoring of neurodegeneration. In addition, insoluble α-synuclein aggregates were formed in this model. This α-synuclein rat model shows improved face and predictive validity, and therefore offers the possibility to reliably test novel therapeutics. Furthermore, it will be of great value for further research into the molecular pathogenesis of PD and the importance of α-synuclein aggregation in the disease process. PMID:25599874

  7. Incorporation of Adeno-Associated Virus in a Calcium Phosphate Coprecipitate Improves Gene Transfer to Airway Epithelia In Vitro and In Vivo

    PubMed Central

    Walters, Robert W.; Duan, Dongsheng; Engelhardt, John F.; Welsh, Michael J.

    2000-01-01

    Adeno-associated virus (AAV) is inefficient at infecting differentiated airway epithelia because of a lack of receptors at the apical surface. We hypothesized that incorporation of AAV in a calcium phosphate coprecipitate would circumvent this barrier. Interestingly, coprecipitation of AAV type 2 improved gene transfer to differentiated human airway epithelia in vitro and to the mouse lung in vivo. These results suggest that delivery of AAV as a CaPi coprecipitate may significantly enhance its utility for gene transfer to the airway epithelia in vivo. PMID:10590145

  8. Pulmonary Targeting of Adeno-associated Viral Vectors by Next-generation Sequencing-guided Screening of Random Capsid Displayed Peptide Libraries.

    PubMed

    Körbelin, Jakob; Sieber, Timo; Michelfelder, Stefan; Lunding, Lars; Spies, Elmar; Hunger, Agnes; Alawi, Malik; Rapti, Kleopatra; Indenbirken, Daniela; Müller, Oliver J; Pasqualini, Renata; Arap, Wadih; Kleinschmidt, Jürgen A; Trepel, Martin

    2016-06-01

    Vectors mediating strong, durable, and tissue-specific transgene expression are mandatory for safe and effective gene therapy. In settings requiring systemic vector administration, the availability of suited vectors is extremely limited. Here, we present a strategy to select vectors with true specificity for a target tissue from random peptide libraries displayed on adeno-associated virus (AAV) by screening the library under circulation conditions in a murine model. Guiding the in vivo screening by next-generation sequencing, we were able to monitor the selection kinetics and to determine the right time point to discontinue the screening process. The establishment of different rating scores enabled us to identify the most specifically enriched AAV capsid candidates. As proof of concept, a capsid variant was selected that specifically and very efficiently delivers genes to the endothelium of the pulmonary vasculature after intravenous administration. This technical approach of selecting target-specific vectors in vivo is applicable to any given tissue of interest and therefore has broad implications in translational research and medicine. PMID:27018516

  9. Characterization of Cognitive Deficits in Rats Overexpressing Human Alpha-Synuclein in the Ventral Tegmental Area and Medial Septum Using Recombinant Adeno-Associated Viral Vectors

    PubMed Central

    Hall, Hélène; Jewett, Michael; Landeck, Natalie; Nilsson, Nathalie; Schagerlöf, Ulrika; Leanza, Giampiero; Kirik, Deniz

    2013-01-01

    Intraneuronal inclusions containing alpha-synuclein (a-syn) constitute one of the pathological hallmarks of Parkinson's disease (PD) and are accompanied by severe neurodegeneration of A9 dopaminergic neurons located in the substantia nigra. Although to a lesser extent, A10 dopaminergic neurons are also affected. Neurodegeneration of other neuronal populations, such as the cholinergic, serotonergic and noradrenergic cell groups, has also been documented in PD patients. Studies in human post-mortem PD brains and in rodent models suggest that deficits in cholinergic and dopaminergic systems may be associated with the cognitive impairment seen in this disease. Here, we investigated the consequences of targeted overexpression of a-syn in the mesocorticolimbic dopaminergic and septohippocampal cholinergic pathways. Rats were injected with recombinant adeno-associated viral vectors encoding for either human wild-type a-syn or green fluorescent protein (GFP) in the ventral tegmental area and the medial septum/vertical limb of the diagonal band of Broca, two regions rich in dopaminergic and cholinergic neurons, respectively. Histopathological analysis showed widespread insoluble a-syn positive inclusions in all major projections areas of the targeted nuclei, including the hippocampus, neocortex, nucleus accumbens and anteromedial striatum. In addition, the rats overexpressing human a-syn displayed an abnormal locomotor response to apomorphine injection and exhibited spatial learning and memory deficits in the Morris water maze task, in the absence of obvious spontaneous locomotor impairment. As losses in dopaminergic and cholinergic immunoreactivity in both the GFP and a-syn expressing animals were mild-to-moderate and did not differ from each other, the behavioral impairments seen in the a-syn overexpressing animals appear to be determined by the long term persisting neuropathology in the surviving neurons rather than by neurodegeneration. PMID:23705016

  10. Absolute determination of single-stranded and self-complementary adeno-associated viral vector genome titers by droplet digital PCR.

    PubMed

    Lock, Martin; Alvira, Mauricio R; Chen, Shu-Jen; Wilson, James M

    2014-04-01

    Accurate titration of adeno-associated viral (AAV) vector genome copies is critical for ensuring correct and reproducible dosing in both preclinical and clinical settings. Quantitative PCR (qPCR) is the current method of choice for titrating AAV genomes because of the simplicity, accuracy, and robustness of the assay. However, issues with qPCR-based determination of self-complementary AAV vector genome titers, due to primer-probe exclusion through genome self-annealing or through packaging of prematurely terminated defective interfering (DI) genomes, have been reported. Alternative qPCR, gel-based, or Southern blotting titering methods have been designed to overcome these issues but may represent a backward step from standard qPCR methods in terms of simplicity, robustness, and precision. Droplet digital PCR (ddPCR) is a new PCR technique that directly quantifies DNA copies with an unparalleled degree of precision and without the need for a standard curve or for a high degree of amplification efficiency; all properties that lend themselves to the accurate quantification of both single-stranded and self-complementary AAV genomes. Here we compare a ddPCR-based AAV genome titer assay with a standard and an optimized qPCR assay for the titration of both single-stranded and self-complementary AAV genomes. We demonstrate absolute quantification of single-stranded AAV vector genomes by ddPCR with up to 4-fold increases in titer over a standard qPCR titration but with equivalent readout to an optimized qPCR assay. In the case of self-complementary vectors, ddPCR titers were on average 5-, 1.9-, and 2.3-fold higher than those determined by standard qPCR, optimized qPCR, and agarose gel assays, respectively. Droplet digital PCR-based genome titering was superior to qPCR in terms of both intra- and interassay precision and is more resistant to PCR inhibitors, a desirable feature for in-process monitoring of early-stage vector production and for vector genome biodistribution

  11. Correction of multiple striated muscles in murine Pompe disease through adeno-associated virus-mediated gene therapy.

    PubMed

    Sun, Baodong; Young, Sarah P; Li, Ping; Di, Chunhui; Brown, Talmage; Salva, Maja Z; Li, Songtao; Bird, Andrew; Yan, Zhen; Auten, Richard; Hauschka, Stephen D; Koeberl, Dwight D

    2008-08-01

    Glycogen storage disease type II (Pompe disease; MIM 232300) stems from the deficiency of acid alpha-glucosidase (GAA; acid maltase; EC 3.2.1.20), which primarily involves cardiac and skeletal muscles. An adeno-associated virus 2/8 (AAV2/8) vector containing the muscle creatine kinase (MCK) (CK1) reduced glycogen content by approximately 50% in the heart and quadriceps in GAA-knockout (GAA-KO) mice; furthermore, an AAV2/8 vector containing the hybrid alpha-myosin heavy chain enhancer-/MCK enhancer-promoter (MHCK7) cassette reduced glycogen content by >95% in heart and >75% in the diaphragm and quadriceps. Transduction with an AAV2/8 vector was higher in the quadriceps than in the gastrocnemius. An AAV2/9 vector containing the MHCK7 cassette corrected GAA deficiency in the distal hindlimb, and glycogen accumulations were substantially cleared by human GAA (hGAA) expression therein; however, the analogous AAV2/7 vector achieved much lower efficacy. Administration of the MHCK7-containing vectors significantly increased striated muscle function as assessed by increased Rotarod times at 18 weeks after injection, whereas the CK1-containing vector did not increase Rotarod performance. Importantly, type IIb myofibers in the extensor digitalis longus (EDL) were transduced, thereby correcting a myofiber type that is unresponsive to enzyme replacement therapy. In summary, AAV8 and AAV9-pseudotyped vectors containing the MHCK7 regulatory cassette achieved enhanced efficacy in Pompe disease mice. PMID:18560415

  12. Correction of Multiple Striated Muscles in Murine Pompe Disease Through Adeno-associated Virus-Mediated Gene Therapy

    PubMed Central

    Sun, Baodong; Young, Sarah P.; Li, Ping; Di, Chunhui; Brown, Talmage; Salva, Maia Z.; Li, Songtao; Bird, Andrew; Yan, Zhen; Auten, Richard; Hauschka, Stephen D.; Koeberl, Dwight D.

    2009-01-01

    Glycogen storage disease type II (GSD-II; Pompe disease; MIM 232300) stems from the deficiency of acid-α-glucosidase (GAA; acid maltase; EC 3.2.1.20), which primarily involves cardiac and skeletal muscles. We hypothesized that systemic administration of an adeno-associated virus (AAV) vector containing a muscle specific regulatory cassette could drive efficacious transgene expression in GAA-knockout (GAA-KO) mice. AAV2/8 vectors containing the muscle creatine kinase (CK1) or hybrid α-myosin heavy chain enhancer-/muscle creatine kinase enhancer-promoter (MHCK7) cassettes were compared. The CK1 reduced glycogen content by approximately 50% in the heart and quadriceps, in comparison to untreated GAA-KO mice, whereas the MHCK7 containing vector reduced glycogen content even further: >95% in heart and >75% in the diaphragm and quadriceps. Administration of the MHCK7-containing vector significantly increased striated muscle function as assessed by increased Rotarod times at 18 weeks post-injection, whereas the CK1-containing vector did not increase Rotarod performance. Transduction efficiency was evaluated with an AAV2/8 vector in which MHCK7 drives alkaline-phosphatase, revealing that many more myofibers were transduced in the quadriceps than in the gastrocnemius. An AAV2/9 vector containing the MHCK7 cassette corrected GAA deficiency in the skeletal muscles of the distal limb, including the gastrocnemius, extensor digitalis longus, and soleus; furthermore, glycogen accumulations were substantially cleared by hGAA expression therein. Importantly, type IIb myofibers in the extensor digitalis longus were transduced, thereby correcting a myofiber type that is unresponsive to enzyme replacement therapy. In summary, AAV8 and AAV9-pseudotyped vectors containing the MHCK7 regulatory cassette achieved enhanced efficacy in Pompe disease mice. PMID:18560415

  13. Recombinant adeno-associated virus-mediated gene transfer for the potential therapy of adenosine deaminase-deficient severe combined immune deficiency.

    PubMed

    Silver, Jared N; Elder, Melissa; Conlon, Thomas; Cruz, Pedro; Wright, Amy J; Srivastava, Arun; Flotte, Terence R

    2011-08-01

    Severe combined immune deficiency due to adenosine deaminase (ADA) deficiency is a rare, potentially fatal pediatric disease, which results from mutations within the ADA gene, leading to metabolic abnormalities and ultimately profound immunologic and nonimmunologic defects. In this study, recombinant adeno-associated virus (rAAV) vectors based on serotypes 1 and 9 were used to deliver a secretory version of the human ADA (hADA) gene to various tissues to promote immune reconstitution following enzyme expression in a mouse model of ADA deficiency. Here, we report that a single-stranded rAAV vector, pTR2-CB-Igκ-hADA, (1) facilitated successful gene delivery to multiple tissues, including heart, skeletal muscle, and kidney, (2) promoted ectopic expression of hADA, and (3) allowed enhanced serum-based enzyme activity over time. Moreover, the rAAV-hADA vector packaged in serotype 9 capsid drove partial, prolonged, and progressive immune reconstitution in ADA-deficient mice. Overview Summary Gene therapies for severe combined immune deficiency due to adenosine deaminase (ADA) deficiency (ADA-SCID) over two decades have exclusively involved retroviral vectors targeted to lymphocytes and hematopoietic progenitor cells. These groundbreaking gene therapies represented an unprecedented revolution in clinical medicine but in most cases did not fully correct the immune deficiency and came with the potential risk of insertional mutagenesis. Alternatively, recombinant adeno-associated virus (rAAV) vectors have gained attention as valuable tools for gene transfer, having demonstrated no pathogenicity in humans, minimal immunogenicity, long-term efficacy, ease of administration, and broad tissue tropism (Muzyczka, 1992 ; Flotte et al., 1993 ; Kessler et al., 1996 ; McCown et al., 1996 ; Lipkowitz et al., 1999 ; Marshall, 2001 ; Chen et al., 2003 ; Conlon and Flotte, 2004 ; Griffey et al., 2005 ; Pacak et al., 2006 ; Stone et al., 2008 ; Liu et al., 2009 ; Choi et al., 2010

  14. Adeno-associated virus type 2 rep gene-mediated inhibition of basal gene expression of human immunodeficiency virus type 1 involves its negative regulatory functions.

    PubMed Central

    Oelze, I; Rittner, K; Sczakiel, G

    1994-01-01

    Adeno-associated virus type 2 (AAV-2), a human parvovirus which is apathogenic in adults, inhibits replication and gene expression of human immunodeficiency virus type 1 (HIV-1) in human cells. The rep gene of AAV-2, which was shown earlier to be sufficient for this negative interference, also down-regulated the expression of heterologous sequences driven by the long terminal repeat (LTR) of HIV-1. This effect was observed in the absence of the HIV-1 transactivator Tat, i.e., at basal levels of LTR-driven transcription. In this work, we studied the involvement of functional subsequences of the HIV-1 LTR in rep-mediated inhibition in the absence of Tat. Mutated LTRs driving an indicator gene (cat) were cointroduced into human SW480 cells together with rep alone or with double-stranded DNA fragments or RNA containing sequences of the HIV-1 LTR. The results indicate that rep strongly enhances the function of negative regulatory elements of the LTR. In addition, the experiments revealed a transcribed sequence element located within the TAR-coding sequence termed AHHH (AAV-HIV homology element derived from HIV-1) which is involved in rep-mediated inhibition. The AHHH element is also involved in down-regulation of basal expression levels in the absence of rep, suggesting that AHHH also contributes to negative regulatory functions of the LTR of HIV-1. In contrast, positive regulatory elements of the HIV-1 LTR such as the NF kappa B and SP1 binding sites have no significant influence on the rep-mediated inhibition. Images PMID:8289357

  15. Developmental stage determines efficiency of gene transfer to muscle satellite cells by in utero delivery of adeno-associated virus vector serotype 2/9.

    PubMed

    Stitelman, David H; Brazelton, Tim; Bora, Archana; Traas, Jeremy; Merianos, Demetri; Limberis, Maria; Davey, Marcus; Flake, Alan W

    2014-01-01

    Efficient gene transfer to muscle stem cells (satellite cells) has not been achieved despite broad transduction of skeletal muscle by systemically administered adeno-associated virus serotype 2/9 (AAV-9) in mice. We hypothesized that cellular migration during fetal development would make satellite cells accessible for gene transfer following in utero intravascular injection. We injected AAV-9 encoding green fluorescent protein (GFP) marker gene into the vascular space of mice ranging in ages from post-coital day 12 (E12) to postnatal day 1 (P1). Satellite cell transduction was examined using: immunohistochemistry and confocal microscopy, satellite cell migration assay, myofiber isolation and FACS analysis. GFP positive myofibers were detected in all mature skeletal muscle groups and up to 100% of the myofibers were transduced. We saw gestational variation in cardiac and skeletal muscle expression. E16 injection resulted in 27.7 ± 10.0% expression in satellite cells, which coincides with the timing of satellite cell migration, and poor satellite cell expression before and after satellite cell migration (E12 and P1). Our results demonstrate that efficient gene expression is achieved in differentiated myofibers and satellite cells after injection of AAV-9 in utero. These findings support the potential of prenatal gene transfer for muscle based treatment strategies. PMID:26015979

  16. Construction and gene expression analysis of a single-stranded DNA minivector based on an inverted terminal repeat of adeno-associated virus.

    PubMed

    Ping, Han; Liu, Xiaomei; Zhu, Dongqin; Li, Taiming; Zhang, Chun

    2015-04-01

    The plasmid vectors currently used for nonviral gene transfer have the disadvantage of carrying a bacterial backbone and an antibiotic resistance gene, which may cause side effects. The adeno-associated virus (AAV) genome is a linear single-stranded DNA (ssDNA) molecule with palindromic inverted terminal repeat (ITR) sequences forming double-stranded DNA (dsDNA) hairpin (HP) structures at each end. Based on the AAV genome, we constructed an AAV-ITR ssDNA minivector that consists of a GFP expression cassette flanked by both ITR sequences of 125 nucleotides. The minivectors were produced by digestion of the parental plasmids followed by denaturation. The self-complementary inverted T-shaped HP structure of the minivector was automatically formed. The HEK 293T cells were transfected with the AAV-ITR ssDNA minivector, plasmid, and dsDNA expression cassette. The results showed that AAV-ITR ssDNA minivector had relatively low gene expression efficiency in vitro. However, we found that the GFP expression efficiency of the D sequence-deleted AAV-ITR ssDNA minivector was significantly increased and was similar to those obtained with the plasmid and dsDNA expression cassette. Our data suggest that the AAV-ITR ssDNA minivector may be a new type of gene expression vector for gene therapy besides the virus and plasmid. PMID:25555376

  17. Ex vivo intracoronary gene transfer of adeno-associated virus 2 leads to superior transduction over serotypes 8 and 9 in rat heart transplants.

    PubMed

    Raissadati, Alireza; Jokinen, Janne J; Syrjälä, Simo O; Keränen, Mikko A I; Krebs, Rainer; Tuuminen, Raimo; Arnaudova, Ralica; Rouvinen, Eeva; Anisimov, Andrey; Soronen, Jarkko; Pajusola, Katri; Alitalo, Kari; Nykänen, Antti I; Lemström, Karl

    2013-11-01

    Heart transplant gene therapy requires vectors with long-lasting gene expression, high cardiotropism, and minimal pathological effects. Here, we examined transduction properties of ex vivo intracoronary delivery of adeno-associated virus (AAV) serotype 2, 8, and 9 in rat syngenic and allogenic heart transplants. Adult Dark Agouti (DA) rat hearts were intracoronarily perfused ex vivo with AAV2, AAV8, or AAV9 encoding firefly luciferase and transplanted heterotopically into the abdomen of syngenic DA or allogenic Wistar-Furth (WF) recipients. Serial in vivo bioluminescent imaging of syngraft and allograft recipients was performed for 6 months and 4 weeks, respectively. Grafts were removed for PCR-, RT-PCR, and luminometer analysis. In vivo bioluminescent imaging of recipients showed that AAV9 induced a prominent and stable luciferase activity in the abdomen, when compared with AAV2 and AAV8. However, ex vivo analyses revealed that intracoronary perfusion with AAV2 resulted in the highest heart transplant transduction levels in syngrafts and allografts. Ex vivo intracoronary delivery of AAV2 resulted in efficient transgene expression in heart transplants, whereas intracoronary AAV9 escapes into adjacent tissues. In terms of cardiac transduction, these results suggest AAV2 as a potential vector for gene therapy in preclinical heart transplants studies, and highlight the importance of delivery route in gene transfer studies. PMID:24102821

  18. Production of CFTR-null and CFTR-ΔF508 heterozygous pigs by adeno-associated virus–mediated gene targeting and somatic cell nuclear transfer

    PubMed Central

    Rogers, Christopher S.; Hao, Yanhong; Rokhlina, Tatiana; Samuel, Melissa; Stoltz, David A.; Li, Yuhong; Petroff, Elena; Vermeer, Daniel W.; Kabel, Amanda C.; Yan, Ziying; Spate, Lee; Wax, David; Murphy, Clifton N.; Rieke, August; Whitworth, Kristin; Linville, Michael L.; Korte, Scott W.; Engelhardt, John F.; Welsh, Michael J.; Prather, Randall S.

    2008-01-01

    Progress toward understanding the pathogenesis of cystic fibrosis (CF) and developing effective therapies has been hampered by lack of a relevant animal model. CF mice fail to develop the lung and pancreatic disease that cause most of the morbidity and mortality in patients with CF. Pigs may be better animals than mice in which to model human genetic diseases because their anatomy, biochemistry, physiology, size, and genetics are more similar to those of humans. However, to date, gene-targeted mammalian models of human genetic disease have not been reported for any species other than mice. Here we describe the first steps toward the generation of a pig model of CF. We used recombinant adeno-associated virus (rAAV) vectors to deliver genetic constructs targeting the CF transmembrane conductance receptor (CFTR) gene to pig fetal fibroblasts. We generated cells with the CFTR gene either disrupted or containing the most common CF-associated mutation (ΔF508). These cells were used as nuclear donors for somatic cell nuclear transfer to porcine oocytes. We thereby generated heterozygote male piglets with each mutation. These pigs should be of value in producing new models of CF. In addition, because gene-modified mice often fail to replicate human diseases, this approach could be used to generate models of other human genetic diseases in species other than mice. PMID:18324337

  19. Production of CFTR-null and CFTR-DeltaF508 heterozygous pigs by adeno-associated virus-mediated gene targeting and somatic cell nuclear transfer.

    PubMed

    Rogers, Christopher S; Hao, Yanhong; Rokhlina, Tatiana; Samuel, Melissa; Stoltz, David A; Li, Yuhong; Petroff, Elena; Vermeer, Daniel W; Kabel, Amanda C; Yan, Ziying; Spate, Lee; Wax, David; Murphy, Clifton N; Rieke, August; Whitworth, Kristin; Linville, Michael L; Korte, Scott W; Engelhardt, John F; Welsh, Michael J; Prather, Randall S

    2008-04-01

    Progress toward understanding the pathogenesis of cystic fibrosis (CF) and developing effective therapies has been hampered by lack of a relevant animal model. CF mice fail to develop the lung and pancreatic disease that cause most of the morbidity and mortality in patients with CF. Pigs may be better animals than mice in which to model human genetic diseases because their anatomy, biochemistry, physiology, size, and genetics are more similar to those of humans. However, to date, gene-targeted mammalian models of human genetic disease have not been reported for any species other than mice. Here we describe the first steps toward the generation of a pig model of CF. We used recombinant adeno-associated virus (rAAV) vectors to deliver genetic constructs targeting the CF transmembrane conductance receptor (CFTR) gene to pig fetal fibroblasts. We generated cells with the CFTR gene either disrupted or containing the most common CF-associated mutation (DeltaF508). These cells were used as nuclear donors for somatic cell nuclear transfer to porcine oocytes. We thereby generated heterozygote male piglets with each mutation. These pigs should be of value in producing new models of CF. In addition, because gene-modified mice often fail to replicate human diseases, this approach could be used to generate models of other human genetic diseases in species other than mice. PMID:18324337

  20. Delivery of the 7-dehydrocholesterol reductase gene to the central nervous system using adeno-associated virus vector in a mouse model of Smith-Lemli-Opitz Syndrome

    PubMed Central

    Pasta, Saloni; Akhile, Omoye; Tabron, Dorothy; Ting, Flora; Shackleton, Cedric; Watson, Gordon

    2015-01-01

    Smith Lemli Opitz syndrome (SLOS) is an inherited malformation and mental retardation metabolic disorder with no cure. Mutations in the last enzyme of the cholesterol biosynthetic pathway, 7-dehydrocholesterol reductase (DHCR7), lead to cholesterol insufficiency and accumulation of its dehyrdocholesterol precursors, and contribute to its pathogenesis. The central nervous system (CNS) constitutes a major pathophysiological component of this disorder and remains unamenable to dietary cholesterol therapy due to the impenetrability of the blood brain barrier (BBB). The goal of this study was to restore sterol homeostasis in the CNS. To bypass the BBB, gene therapy using an adeno-associated virus (AAV-8) vector carrying a functional copy of the DHCR7 gene was administered by intrathecal (IT) injection directly into the cerebrospinal fluid of newborn mice. Two months post-treatment, vector DNA and DHCR7 expression was observed in the brain and a corresponding improvement of sterol levels seen in the brain and spinal cord. Interestingly, sterol levels in the peripheral nervous system also showed a similar improvement. This study shows that IT gene therapy can have a positive biochemical effect on sterol homeostasis in the central and peripheral nervous systems in a SLOS animal model. A single dose delivered three days after birth had a sustained effect into adulthood, eight weeks post-treatment. These observations pave the way for further studies to understand the effect of biochemical improvement of sterol levels on neuronal function, to provide a greater understanding of neuronal cholesterol homeostasis, and to develop potential therapies. PMID:26347274

  1. Preclinical safety evaluation of recombinant adeno-associated virus 2 vector encoding human tumor necrosis factor receptor-immunoglobulin Fc fusion gene.

    PubMed

    Zhou, Xiaobing; Shen, Lianzhong; Liu, Li; Wang, Chao; Qi, Weihong; Zhao, Aizhi; Wu, Xiaobing; Li, Bo

    2016-03-01

    Recombinant adeno-associated virus (rAAV) 2 vector gene therapy offers promise for the healing of Rheumatoid arthritis. To support the clinical development of the candidate gene therapeutic product in China, a comprehensive preclinical safety assessment of rAAV2 encoding human TNF receptor-immunoglobulin Fc fusion gene (rAAV2/human TNFR:Fc), were conducted in 3 species of experimental animals. No abnormal findings were observed in mice following single intravenous administration with test article. Compared with the control group, no differences in mean body weight, food consumption in rats and monkeys following the repeated intraarticular administration with rAAV2/human TNFR:Fc. There were also no significant adverse effects due to treatment noted by clinical chemistry, hematology and pathology assessments. After intraarticular administration with rAAV2/human TNFR:Fc, the vector DNA initially distributed to spleen, lymph nodes, and joint synovium. The vector DNA cleared rapidly as it could be detected mainly at the site of injection by 91 d post-administration (182 d for monkey). Taken together, localized delivery of rAAV2/human TNFR:Fc showed no significant toxicity in mice, rats, and monkeys, which support the planned clinical evaluation of this product. PMID:26837862

  2. Adeno-associated virus 2-mediated antiangiogenic cancer gene therapy: long-term efficacy of a vector encoding angiostatin and endostatin over vectors encoding a single factor.

    PubMed

    Ponnazhagan, Selvarangan; Mahendra, Gandham; Kumar, Sanjay; Shaw, Denise R; Stockard, Cecil R; Grizzle, William E; Meleth, Sreelatha

    2004-03-01

    Angiogenesis is characteristic of solid tumor growth and a surrogate marker for metastasis in many human cancers. Inhibition of tumor angiogenesis using antiangiogenic drugs and gene transfer approaches has suggested the potential of this form of therapy in controlling tumor growth. However, for long-term tumor-free survival by antiangiogenic therapy, the factors controlling tumor neovasculature need to be systemically maintained at stable therapeutic levels. Here we show sustained expression of the antiangiogenic factors angiostatin and endostatin as secretory proteins by recombinant adeno-associated virus 2 (rAAV)-mediated gene transfer. Both vectors provided significant protective efficacy in a mouse tumor xenograft model. Stable transgene persistence and systemic levels of both angiostatin and endostatin were confirmed by in situ hybridization of the vector-injected tissues and by serum ELISA measurements, respectively. Whereas treatment with rAAV containing either endostatin or angiostatin alone resulted in moderate to significant protection, the combination of endostatin and angiostatin gene transfer from a single vector resulted in a complete protection. These data suggest that AAV-mediated long-term expression of both endostatin and angiostatin may have clinical utility against recurrence of cancers after primary therapies and may represent rational adjuvant therapies in combination with radiation or chemotherapy. PMID:14996740

  3. HoxD10 gene delivery using adenovirus/adeno-associate hybrid virus inhibits the proliferation and tumorigenicity of GH4 pituitary lactotrope tumor cells

    SciTech Connect

    Cho, Mi Ae; Yashar, Parham; Kim, Suk Kyoung; Noh, Taewoong; Gillam, Mary P.; Lee, Eun Jig Jameson, J. Larry

    2008-07-04

    Prolactinoma is one of the most common types of pituitary adenoma. It has been reported that a variety of growth factors and cytokines regulating cell growth and angiogenesis play an important role in the growth of prolactinoma. HoxD10 has been shown to impair endothelial cell migration, block angiogenesis, and maintain a differentiated phenotype of cells. We investigated whether HoxD10 gene delivery could inhibit the growth of prolactinoma. Rat GH4 lactotrope tumor cells were infected with adenovirus/adeno-associated virus (Ad/AAV) hybrid vectors carrying the mouse HoxD10 gene (Hyb-HoxD10) or the {beta}-galactosidase gene (Hyb-Gal). Hyb-HoxD10 expression inhibited GH4 cell proliferation in vitro. The expression of FGF-2 and cyclin D2 was inhibited in GH4 cells infected with Hyb-HoxD10. GH4 cells transduced with Hyb-HoxD10 did not form tumors in nude mice. These results indicate that the delivery of HoxD10 could potentially inhibit the growth of PRL-secreting tumors. This approach may be a useful tool for targeted therapy of prolactinoma and other neoplasms.

  4. Human α7 Integrin Gene (ITGA7) Delivered by Adeno-Associated Virus Extends Survival of Severely Affected Dystrophin/Utrophin-Deficient Mice.

    PubMed

    Heller, Kristin N; Montgomery, Chrystal L; Shontz, Kimberly M; Clark, K Reed; Mendell, Jerry R; Rodino-Klapac, Louise R

    2015-10-01

    Duchenne muscular dystrophy (DMD) is caused by mutations in the DMD gene. It is the most common, severe childhood form of muscular dystrophy. We investigated an alternative to dystrophin replacement by overexpressing ITGA7 using adeno-associated virus (AAV) delivery. ITGA7 is a laminin receptor in skeletal muscle that, like the dystrophin-glycoprotein complex, links the extracellular matrix to the internal actin cytoskeleton. ITGA7 is expressed in DMD patients and overexpression does not elicit an immune response to the transgene. We delivered rAAVrh.74.MCK.ITGA7 systemically at 5-7 days of age to the mdx/utrn(-/-) mouse deficient for dystrophin and utrophin, a severe mouse model of DMD. At 8 weeks postinjection, widespread expression of ITGA7 was observed at the sarcolemma of multiple muscle groups following gene transfer. The increased expression of ITGA7 significantly extended longevity and reduced common features of the mdx/utrn(-/-) mouse, including kyphosis. Overexpression of α7 expression protected against loss of force following contraction-induced damage and increased specific force in the diaphragm and EDL muscles 8 weeks after gene transfer. Taken together, these results further support the use of α7 integrin as a potential therapy for DMD. PMID:26076707

  5. Silencing of T lymphocytes by antigen-driven programmed death in recombinant adeno-associated virus vector–mediated gene therapy

    PubMed Central

    Velazquez, Victoria M.; Bowen, David G.

    2009-01-01

    Recombinant adeno-associated virus (rAAV) vectors are considered promising for human gene replacement because they facilitate stable expression of therapeutic proteins in transduced tissues. Whether the success of gene therapy will be influenced by cellular immune responses targeting transgene-encoded proteins that are potentially immunogenic is unknown. Here we characterized CD8+ T-cell activity against β-galactosidase and enhanced green fluorescent protein, model antigens containing major histocompatibility complex (MHC) class I epitopes that are constitutively produced in murine skeletal muscle after rAAV vector transduction. Antigen-specific CD8+ T cells were detected in the spleen and liver of mice within 7 days of muscle transduction. CD8+ T-cell frequencies in these organs were stable, and effector functions were intact for months despite ongoing antigen production in muscle. CD8+ T cells also infiltrated transduced muscle, where frequencies were at least 5-fold higher than in untransduced spleen and liver. Significantly, the majority of antigen-specific CD8+ T cells in vector-transduced muscle were not functional. Loss of function in the muscle was associated with programmed death of the effector cells. Stable gene expression therefore depended on selective death of CD8+ T cells at the site of antigen production, an effective mechanism for subverting immunity that is also potentially reversible. PMID:18566327

  6. Recombinant adeno-associated virus (rAAV)-mediated expression of a human gamma-globin gene in human progenitor-derived erythroid cells.

    PubMed Central

    Miller, J L; Donahue, R E; Sellers, S E; Samulski, R J; Young, N S; Nienhuis, A W

    1994-01-01

    Effective gene therapy for the severe hemoglobin (Hb) disorders, sickle-cell anemia and thalassemia, will require an efficient method to transfer, integrate, and express a globin gene in primary erythroid cells. To evaluate recombinant adeno-associated virus (rAAV) for this purpose, we constructed a rAAV vector encoding a human gamma-globin gene (pJM24/vHS432A gamma). Its 4725-nucleotide genome consists of two 180-bp AAV inverted terminal repeats flanking the core elements of hypersensitive sites 2, 3, and 4 from the locus control region of the beta-globin gene cluster, linked to a mutationally marked A gamma-globin gene (A gamma) containing native promoter and RNA processing signals. CD34+ human hematopoietic cells were exposed to rAAV particles at a multiplicity of infection of 500-1000 and cultured in semisolid medium containing several cytokines. A reverse transcriptase polymerase chain reaction assay distinguished mRNA signals derived from transduced and endogenous human gamma-globin genes. Twenty to 40% of human erythroid burst-forming unit-derived colonies expressed the rAAV-transduced A gamma-globin gene at levels 4-71% that of the endogenous gamma-globin genes. The HbF content of pooled control colonies was 26%, whereas HbF was 40% of the total in pooled colonies derived from rAAV transduced progenitors. These data establish that rAAV containing elements from the locus control region linked to a gamma-globin gene are capable of transferring and expressing that gene in primary human hematopoietic cells resulting in a substantial increase in HbF content. Images PMID:7524085

  7. The Rep78 gene product of adeno-associated virus (AAV) self-associates to form a hexameric complex in the presence of AAV ori sequences.

    PubMed Central

    Smith, R H; Spano, A J; Kotin, R M

    1997-01-01

    The Rep78 and Rep68 proteins of adeno-associated virus (AAV) are replication initiator proteins that bind the viral replicative-form origin of replication, nick the origin in a site- and strand-specific fashion, and mediate vectorial unwinding of the DNA duplex via an ATP-dependent helicase activity, thus initiating a strand displacement mechanism of viral DNA replication. Genetic and biochemical studies have identified Rep mutants that demonstrate a trans-dominant negative phenotype in vitro and in vivo, suggesting the possibility that multimerization of Rep is essential for certain replicative functions. In this study, we have investigated the ability of the largest of the Rep proteins, Rep78, to self-associate in vitro and in vivo. Self-association of Rep78 in vivo was demonstrated through the use of a mammalian two-hybrid system. Rep-Rep protein interaction was confirmed in vitro through coimmunoprecipitation experiments with a bacterially expressed maltose-binding protein-Rep78 fusion protein in combination with [35S]methionine-labeled Rep78 synthesized in a coupled in vitro transcription-translation system. Mapping studies with N- and C-terminal truncation mutant forms of Rep indicate that amino acid sequences required for maximal self-association occur between residues 164 and 484. Site-directed mutagenesis identified two essential motifs within this 321-amino-acid region: (i) a putative alpha-helix bearing a 3,4-hydrophobic heptad repeat reminiscent of those found in coiled-coil domains and (ii) a previously recognized nucleoside triphosphate-binding motif. Deletion of either of these regions from the full-length polypeptide resulted in severe impairment of Rep-Rep interaction. In addition, gel filtration chromatography and protein cross-linking experiments indicated that Rep78 forms a hexameric complex in the presence of AAV ori sequences. PMID:9151837

  8. Adeno-associated Virus as a Mammalian DNA Vector

    PubMed Central

    SALGANIK, MAX; HIRSCH, MATTHEW L.; SAMULSKI, RICHARD JUDE

    2015-01-01

    In the nearly five decades since its accidental discovery, adeno-associated virus (AAV) has emerged as a highly versatile vector system for both research and clinical applications. A broad range of natural serotypes, as well as an increasing number of capsid variants, has combined to produce a repertoire of vectors with different tissue tropisms, immunogenic profiles and transduction efficiencies. The story of AAV is one of continued progress and surprising discoveries in a viral system that, at first glance, is deceptively simple. This apparent simplicity has enabled the advancement of AAV into the clinic, where despite some challenges it has provided hope for patients and a promising new tool for physicians. Although a great deal of work remains to be done, both in studying the basic biology of AAV and in optimizing its clinical application, AAV vectors are currently the safest and most efficient platform for gene transfer in mammalian cells. PMID:26350320

  9. OneBac: Platform for Scalable and High-Titer Production of Adeno-Associated Virus Serotype 1–12 Vectors for Gene Therapy

    PubMed Central

    Mietzsch, Mario; Grasse, Sabrina; Zurawski, Catherine; Weger, Stefan; Bennett, Antonette; Agbandje-McKenna, Mavis; Muzyczka, Nicholas; Zolotukhin, Sergei

    2014-01-01

    Abstract Scalable and genetically stable recombinant adeno-associated virus (rAAV) production systems combined with facile adaptability for an extended repertoire of AAV serotypes are required to keep pace with the rapidly increasing clinical demand. For scalable high-titer production of the full range of rAAV serotypes 1–12, we developed OneBac, consisting of stable insect Sf9 cell lines harboring silent copies of AAV1–12 rep and cap genes induced upon infection with a single baculovirus that also carries the rAAV genome. rAAV burst sizes reach up to 5×105 benzonase-resistant, highly infectious genomic particles per cell, exceeding typical yields of current rAAV production systems. In contrast to recombinant rep/cap baculovirus strains currently employed for large-scale rAAV production, the Sf9rep/cap cell lines are genetically stable, leading to undiminished rAAV burst sizes over serial passages. Thus, OneBac combines full AAV serotype options with the capacity for stable scale-up production, the current bottleneck for the transition of AAV from gene therapy trials to routine clinical treatment. PMID:24299301

  10. A Novel Gene Expression Control System and Its Use in Stable, High-Titer 293 Cell-Based Adeno-Associated Virus Packaging Cell Lines

    PubMed Central

    Qiao, Chunping; Wang, Bing; Zhu, Xiaodong; Li, Juan; Xiao, Xiao

    2002-01-01

    Previous attempts to establish 293cell-based stable and high-titer adeno-associated virus (AAV) packaging cell lines were unsuccessful, primarily due to adenovirus E1-activated Rep gene expression, which exerts cytostatic and cytotoxic effects on the host cells. Control of the two large AAV Rep proteins (Rep78/68) was insufficient to eliminate the adverse effects, because of the leaky expression of the two small Rep proteins (Rep52/40). However, it was unsuccessful to control Rep52/40 gene expression since its promoter is located within the coding sequence of Rep78/68. To tightly regulate all four Rep proteins by using their own promoters, we have developed a novel gene control paradigm termed “dual splicing switch,” which disrupts all four Rep genes by inserting into their shared coding region an intron that harbors transcription termination sequences flanked the LoxP sites. As a result, the structure and activities of the Rep gene promoters, both p5 and p19, are not affected; however, all of the Rep transcripts are prematurely terminated and the genes were inactivated. Removal of the terminator by Cre protein reactivates the transcription of all four Rep proteins derived from their own promoters. This switch system was initially tested in the lacZ gene and a 600-fold induction of β-galactosidase activity was observed. Using the dual splicing switch strategy, we have subsequently established a number of AAV packaging cell lines from 293 cells, which showed a normal growth rate, high stability, and more importantly, high yields of AAV vectors. Such a gene control paradigm is also useful for other viruses, e.g., autonomous parvoviruses. Finally, the high-titer 293-based AAV packaging cell lines should greatly reduce the risk of wild-type adenovirus contamination and provide a scalable AAV vector production method for both preclinical and clinical studies. PMID:12438627

  11. A Rapid, Cost-Effective Method to Prepare Recombinant Adeno-Associated Virus for Efficient Gene Transfer to the Developing Mouse Inner Ear.

    PubMed

    Gomes, Michelle M; Wang, Lingyan; Jiang, Han; Kahl, Christoph A; Brigande, John V

    2016-01-01

    There is keen interest to define gene therapies aimed at restoration of auditory and vestibular function in the diseased or damaged mammalian inner ear. A persistent limitation of regenerative medical strategies that seek to correct or modify gene expression in the sensory epithelia of the inner ear involves efficacious delivery of a therapeutic genetic construct. Our approach is to define methodologies that enable fetal gene transfer to the developing mammalian inner ear in an effort to correct defective gene expression during formation of the sensory epithelia or during early postnatal life. Conceptually, the goal is to atraumatically introduce the genetic construct into the otocyst-staged mouse inner ear and transfect otic progenitors that give rise to sensory hair cells and supporting cells. Our long-term goal is to define therapeutic interventions for congenital deafness and balance disorders with the expectation that the approach may also be exploited for therapeutic intervention postnatally.In the inaugural volume of this series, we introduced electroporation-mediated gene transfer to the developing mouse inner ear that encompassed our mouse survival surgery and transuterine microinjection protocols (Brigande et al., Methods Mol Biol 493:125-139, 2009). In this chapter, we first briefly update our use of sodium pentobarbital anesthesia, our preferred anesthetic for mouse ventral laparotomy, in light of its rapidly escalating cost. Next, we define a rapid, cost-effective method to produce recombinant adeno-associated virus (rAAV) for efficient gene transfer to the developing mouse inner ear. Our immediate goal is to provide a genetic toolkit that will permit the definition and validation of gene therapies in mouse models of human deafness and balance disorders. PMID:27259920

  12. Factors Influencing Adeno-Associated Virus-Mediated Gene Transfer to Human Cystic Fibrosis Airway Epithelial Cells: Comparison with Adenovirus Vectors

    PubMed Central

    Teramoto, S.; Bartlett, J. S.; McCarty, D.; Xiao, X.; Samulski, R. J.; Boucher, R. C.

    1998-01-01

    Adeno-associated virus (AAV) vectors appear promising for use in gene therapy in cystic fibrosis (CF) patients, yet many features of AAV-mediated gene transfer to airway epithelial cells are not well understood. We compared the transduction efficiencies of AAV vectors and adenovirus (Ad) vectors in immortalized cell lines from CF patients and in nasal epithelial primary cultures from normal humans and CF patients. Similar dose-dependent relationships between the vector multiplicities of infection and the efficiencies of lacZ gene transfer were observed. However, levels of transduction for both Ad and recombinant AAV (rAAV) were significantly lower in the airway epithelial cell than in the control cell lines HeLa and HEK 293. Transduction efficiencies differed among cultured epithelial cell types, with poorly differentiated cells transducing more efficiently than well-differentiated cells. A time-dependent increase in gene expression was observed after infection for both vectors. For Ad, but not for AAV, this increase was dependent on prolonged incubation of cells with the vector. Furthermore, for rAAV (but not for rAd), the delay in maximal transduction could be abrogated by wild-type Ad helper infection. Thus, although helper virus is not required for maximal transduction, it increases the kinetics by which this is achieved. Expression of Ad E4 open reading frame 6 or addition of either hydroxyurea or camptothecin resulted in increased AAV transduction, as previously demonstrated for nonairway cells (albeit to lower final levels), suggesting that second-strand synthesis may not be the sole cause of inefficient transduction. Finally, the efficiency of AAV-mediated ex vivo gene transfer to lung cells was similar to that previously described for Ad vectors in that transduction was limited to regions of epithelial injury and preferentially targeted basal-like cells. These studies address the primary factors influencing rAAV infection of human airway cells and should

  13. Factors influencing adeno-associated virus-mediated gene transfer to human cystic fibrosis airway epithelial cells: comparison with adenovirus vectors.

    PubMed

    Teramoto, S; Bartlett, J S; McCarty, D; Xiao, X; Samulski, R J; Boucher, R C

    1998-11-01

    Adeno-associated virus (AAV) vectors appear promising for use in gene therapy in cystic fibrosis (CF) patients, yet many features of AAV-mediated gene transfer to airway epithelial cells are not well understood. We compared the transduction efficiencies of AAV vectors and adenovirus (Ad) vectors in immortalized cell lines from CF patients and in nasal epithelial primary cultures from normal humans and CF patients. Similar dose-dependent relationships between the vector multiplicities of infection and the efficiencies of lacZ gene transfer were observed. However, levels of transduction for both Ad and recombinant AAV (rAAV) were significantly lower in the airway epithelial cell than in the control cell lines HeLa and HEK 293. Transduction efficiencies differed among cultured epithelial cell types, with poorly differentiated cells transducing more efficiently than well-differentiated cells. A time-dependent increase in gene expression was observed after infection for both vectors. For Ad, but not for AAV, this increase was dependent on prolonged incubation of cells with the vector. Furthermore, for rAAV (but not for rAd), the delay in maximal transduction could be abrogated by wild-type Ad helper infection. Thus, although helper virus is not required for maximal transduction, it increases the kinetics by which this is achieved. Expression of Ad E4 open reading frame 6 or addition of either hydroxyurea or camptothecin resulted in increased AAV transduction, as previously demonstrated for nonairway cells (albeit to lower final levels), suggesting that second-strand synthesis may not be the sole cause of inefficient transduction. Finally, the efficiency of AAV-mediated ex vivo gene transfer to lung cells was similar to that previously described for Ad vectors in that transduction was limited to regions of epithelial injury and preferentially targeted basal-like cells. These studies address the primary factors influencing rAAV infection of human airway cells and should

  14. An Adenovirus Type 5 Mutant with the Preterminal Protein Gene Deleted Efficiently Provides Helper Functions for the Production of Recombinant Adeno-Associated Virus

    PubMed Central

    Maxwell, Ian H.; Maxwell, Francoise; Schaack, Jerome

    1998-01-01

    Production of recombinant adeno-associated virus (rAAV) requires helper functions that have routinely been provided by infection of the producer cells with adenovirus. Complete removal and/or inactivation of progeny adenovirus, present in such rAAV preparations, presents significant difficulty. Here, we report that an adenovirus type 5 (Ad5) mutant with the preterminal protein (pTP) gene deleted can provide helper function for the growth of rAAV. At high multiplicity, Ad5dl308ΔpTP was as efficient as the phenotypically wild-type Ad5dl309 in permitting growth of rAAV. Use of Ad5dl308ΔpTP, which is incapable of replication in the absence of complementation for pTP, as a helper avoids the need to remove contaminating adenovirus infectious activity by heat inactivation or by purification. Comparison of the transducing ability of rAAV generated with either Ad5dl308ΔpTP or Ad5dl309 as a helper demonstrated that the heat inactivation protocol generally used does not remove all of the helper Ad5dl309 function. PMID:9733887

  15. Hydrodynamic Limb Vein Injection of Adeno-Associated Virus Serotype 8 Vector Carrying Canine Myostatin Propeptide Gene into Normal Dogs Enhances Muscle Growth

    PubMed Central

    Qiao, Chunping; Li, Juan; Zheng, Hui; Bogan, Janet; Li, Jianbin; Yuan, Zhenhua; Zhang, Cheng; Bogan, Dan; Kornegay, Joe

    2009-01-01

    Abstract Inhibition or blockade of myostatin, a negative growth factor of skeletal muscle, enhances muscle growth and therefore is considered a promising strategy for the treatment of muscle-wasting diseases such as the muscular dystrophies. Previously, we showed that myostatin blockade in both normal and dystrophin-deficient mdx mice by systemic delivery of the myostatin propeptide (MPRO) gene by an adeno-associated virus serotype 8 (AAV8) vector could enhance muscle growth and ameliorate dystrophic lesions. Here, we further investigate whether the muscle growth effect of myostatin blockade can be achieved in dogs by gene transfer. First, we cloned the canine MPRO gene, packaged it in the AAV8 vector, and showed robust muscle-enhancing effects after systemic delivery into neonatal mice. This vector was then further tested in two 3-month-old normal dogs (weighing 9.7 and 6.3 kg). The vector was delivered to one limb by hydrodynamic vein injection, and the contralateral limb served as a control. The delivery procedure was safe, without discernible adverse effects. AAV vector DNA and MPRO gene expression were detected by quantitative polymerase chain reaction, Western blotting, and immunofluorescence staining of muscle biopsies. Overexpression of MPRO resulted in enhanced muscle growth without a cytotoxic T lymphocytic immune response, as evidenced by larger myofibers in multiple muscles, increased muscle volume determined by magnetic resonance imaging, and the lack of CD4+ and CD8+ T cell infiltration in the vector-injected limbs. Our preliminary study thus supports further investigation of this therapeutic strategy in the dystrophin-deficient golden retriever muscular dystrophy dog model. PMID:18828709

  16. Intracerebral adeno-associated virus gene delivery of apolipoprotein E2 markedly reduces brain amyloid pathology in Alzheimer's disease mouse models.

    PubMed

    Zhao, Lingzhi; Gottesdiener, Andrew J; Parmar, Mayur; Li, Mingjie; Kaminsky, Stephen M; Chiuchiolo, Maria J; Sondhi, Dolan; Sullivan, Patrick M; Holtzman, David M; Crystal, Ronald G; Paul, Steven M

    2016-08-01

    The common apolipoprotein E alleles (ε4, ε3, and ε2) are important genetic risk factors for late-onset Alzheimer's disease, with the ε4 allele increasing risk and reducing the age of onset and the ε2 allele decreasing risk and markedly delaying the age of onset. Preclinical and clinical studies have shown that apolipoprotein E (APOE) genotype also predicts the timing and amount of brain amyloid-β (Aβ) peptide deposition and amyloid burden (ε4 >ε3 >ε2). Using several administration protocols, we now report that direct intracerebral adeno-associated virus (AAV)-mediated delivery of APOE2 markedly reduces brain soluble (including oligomeric) and insoluble Aβ levels as well as amyloid burden in 2 mouse models of brain amyloidosis whose pathology is dependent on either the expression of murine Apoe or more importantly on human APOE4. The efficacy of APOE2 to reduce brain Aβ burden in either model, however, was highly dependent on brain APOE2 levels and the amount of pre-existing Aβ and amyloid deposition. We further demonstrate that a widespread reduction of brain Aβ burden can be achieved through a single injection of vector via intrathalamic delivery of AAV expressing APOE2 gene. Our results demonstrate that AAV gene delivery of APOE2 using an AAV vector rescues the detrimental effects of APOE4 on brain amyloid pathology and may represent a viable therapeutic approach for treating or preventing Alzheimer's disease especially if sufficient brain APOE2 levels can be achieved early in the course of the disease. PMID:27318144

  17. A human parvovirus, adeno-associated virus, as a eucaryotic vector: Transient expression and encapsidation of the procaryotic gene for chloramphenicol acetyltransferase

    SciTech Connect

    Tratschin, J.D.; West, M.H.P.; Sandbank, T.; Carter, B.J.

    1984-10-01

    The authors have used the defective human parvovirus adeno-associated virus (AAV) as a novel eurocaryotic vector (parvector) for the expression of a foreign gene in human cells. The recombinant, pAV2, contains the AAV genome in a pBR322-derived bacterial plasmid. When pAV2 is transfected into human cells together with helper adenovirus particles, the AAV genome is rescued from the recombinant plasmid and replicated to produce infectious AAV particles at high efficiency. To create a vector, we inserted a procaryotic sequence coding for chloramphenicol acetyltransferase (CAT) into derivatives of pAV2 following either of the AAV promoters p/sub 40/ (pAVHiCAT) and p/sub 19/ (pAVBcCAT). When transfected into human 293 cells or HeLa cells, pAVHiCAT expressed CAT activity in the absence of adenovirus. In the presence of adenovirus, this vector produced increased amounts of CAT activity and the recombinant AAV-CAT genome was replicated. In 293 cells, pAVBcCAT expressed a similar amount of CAT activity in the absence or presence of adenovirus and the recombinant AAV-CAT genome was not replicated. In HeLa cells, pAVBcCAT expressed low levels of CAT activity, but this level was elevated by coinfection with adenovirus particles or by cotransfection with a plasmid which expressed the adenovirus early region 1A (E1A) product. The E1A product is a transcriptional activator and is expressed in 293 cells. Thus, expression from two AAV promoters is differentially regulated: expression from p/sub 19/ is increased by E1A, whereas p/sub 40/ yields high levels of constitutive expression in the absence of E1A. Both AAV vectors were packaged into AAV particles by complementation with wild-type AAV and yielded CAT activity when subsequently infected into cells in the presence of adenovirus.

  18. Wnt11 Gene Therapy with Adeno-associated Virus 9 Improves Recovery from Myocardial Infarction by Modulating the Inflammatory Response

    PubMed Central

    Morishita, Yoshihiro; Kobayashi, Koichi; Klyachko, Ekaterina; Jujo, Kentaro; Maeda, Kengo; Losordo, Douglas W.; Murohara, Toyoaki

    2016-01-01

    Acute myocardial infarction induces activation of the acute phase response and infiltration of leukocytes to the infarcted area. Moreover, myocardium that is remote from ischemic area also becomes inflamed. Inflammatory reaction clears dead cells and matrix debris, while prolongation or expansion of the inflammatory response results in dysfunction following myocardial infarction. Wnt glycolipoproteins are best characterized as regulators of embryonic development. Recently several reports suggest that they also contribute to the inflammatory response in adult animals. However, the effects of Wnt proteins on myocardial infarction have not been explored. Here we show that Wnt11 expression leads to significant improvements of survival and cardiac function by suppressing infiltration of multiple kinds of inflammatory cells in infarcted heart. Wnt11 protein suppresses gene expression of inflammatory cytokines through the modulation of NF-κB in vitro. These results reveal a novel function of Wnt11 in the regulation of inflammatory response and provide a rationale for the use of Wnt11 to manipulate human diseases that are mediated by inflammation. PMID:26882996

  19. Inexpensive, serotype-independent protocol for native and bioengineered recombinant adeno-associated virus purification

    PubMed Central

    Arden, Erik; Metzger, Joseph M.

    2016-01-01

    Recombinant adeno-associated virus (AAV) is a valuable and often used gene therapy vector. With increased demand for highly purified virus comes the need for a standardized purification procedure that is applicable across many serotypes and includes bioengineered viruses. Currently cesium chloride banding or affinity chromatography are the predominate forms of purification. These approaches expose the final purified virus to toxic contaminants or are highly capsid dependent and may require significant optimization to isolate purified AAV. These methods may also limit crude viral lysate processing volume resulting in a significant loss of viral titer. To circumvent these issues, we have developed an AAV purification protocol independent of toxic compounds, supernatant volume and capsid moiety. This purification method standardizes virus purification across native serotype and bioengineered mosaic capsids. PMID:27294171

  20. Adeno-associated virus rep protein synthesis during productive infection

    SciTech Connect

    Redemann, B.E.; Mendelson, E.; Carter, B.J.

    1989-02-01

    Adeno-associated virus (AAV) Rep proteins mediate viral DNA replication and can regulate expression from AAV genes. The authors studied the kinetics of synthesis of the four Rep proteins, Rep78, Rep68, Rep52, and Rep40, during infection of human 293 or KB cells with AAV and helper adenovirus by in vivo labeling with (/sup 35/S)methionine, immunoprecipitation, and immunoblotting analyses. Rep78 and Rep52 were readily detected concomitantly with detection of viral monomer duplex DNA replicating about 10 to 12 h after infection, and Rep68 and Rep40 were detected 2 h later. Rep78 and Rep52 were more abundant than Rep68 and Rep40 owing to a higher synthesis rate throughout the infectious cycle. In some experiments, very low levels of Rep78 could be detected as early as 4 h after infection. The synthesis rates of Rep proteins were maximal between 14 and 24 h and then decreased later after infection. Isotopic pulse-chase experiments showed that each of the Rep proteins was synthesized independently and was stable for at least 15 h. A slower-migrating, modified form of Rep78 was identified late after infection. AAV capsid protein synthesis was detected at 10 to 12 h after infection and also exhibited synthesis kinetics similar to those of the Rep proteins. AAV DNA replication showed at least two clearly defined stages. Bulk duplex replicating DNA accumulation began around 10 to 12 h and reached a maximum level at about 20 h when Rep and capsid protein synthesis was maximal. Progeny single-stranded DNA accumulation began about 12 to 13 h, but most of this DNA accumulated after 24 h when Rep and capsid protein synthesis had decreased.

  1. The recombinant adeno-associated virus vector (rAAV2)-mediated apolipoprotein B mRNA-specific hammerhead ribozyme: a self-complementary AAV2 vector improves the gene expression

    PubMed Central

    Zhong, Shumei; Sun, Shihua; Teng, Ba-Bie

    2004-01-01

    Background In humans, overproduction of apolipoprotein B (apoB) is positively associated with premature coronary artery diseases. To reduce the levels of apoB mRNA, we have designed an apoB mRNA-specific hammerhead ribozyme targeted at nucleotide sequences GUA6679 (RB15) mediated by adenovirus, which efficiently cleaves and decreases apoB mRNA by 80% in mouse liver and attenuates the hyperlipidemic condition. In the current study, we used an adeno-associated virus vector, serotype 2 (AAV2) and a self-complementary AAV2 vector (scAAV2) to demonstrate the effect of long-term tissue-specific gene expression of RB15 on the regulation apoB mRNA in vivo. Methods We constructed a hammerhead ribozyme RB15 driven by a liver-specific transthyretin (TTR) promoter using an AAV2 vector (rAAV2-TTR-RB15). HepG2 cells and hyperlipidemic mice deficient in both the low density lipoprotein receptor and the apoB mRNA editing enzyme genes (LDLR-/-Apobec1-/-; LDb) were transduced with rAAV2-TTR-RB15 and a control vector rAAV-TTR-RB15-mutant (inactive ribozyme). The effects of ribozyme RB15 on apoB metabolism and atherosclerosis development were determined in LDb mice at 5-month after transduction. A self-complementary AAV2 vector expressing ribozyme RB15 (scAAV2-TTR-RB15) was also engineered and used to transduce HepG2 cells. Studies were designed to compare the gene expression efficiency between rAAV2-TTR-RB15 and scAAV2-TTR-RB15. Results The effect of ribozyme RB15 RNA on reducing apoB mRNA levels in HepG2 cells was observed only on day-7 after rAAV2-TTR-RB15 transduction. And, at 5-month after rAAV2-TTR-RB15 treatment, the apoB mRNA levels in LDb mice were significantly decreased by 43%, compared to LDb mice treated with control vector rAAV2-TTR-RB15-mutant. Moreover, both the rAAV2-TTR-RB15 viral DNA and ribozyme RB15 RNA were still detectable in mice livers at 5-month after treatment. However, this rAAV2-TTR-RB15 vector mediated a prolonged but low level of ribozyme RB15 gene

  2. Production, purification, crystallization and preliminary X-ray structural studies of adeno-associated virus serotype 5

    SciTech Connect

    DiMattia, Michael; Govindasamy, Lakshmanan; Levy, Hazel C.; Gurda-Whitaker, Brittney; Kalina, Amy; Kohlbrenner, Erik; Chiorini, John A.; McKenna, Robert; Muzyczka, Nicholas; Zolotukhin, Sergei; Agbandje-McKenna, Mavis

    2005-10-01

    The production, purification, crystallization and preliminary crystallographic analysis of empty adeno-associated virus serotype 5 capsids are reported. Adeno-associated virus serotype 5 (AAV5) is under development for gene-therapy applications for the treatment of cystic fibrosis. To elucidate the structural features of AAV5 that control its enhanced transduction of the apical surface of airway epithelia compared with other AAV serotypes, X-ray crystallographic studies of the viral capsid have been initiated. The production, purification, crystallization and preliminary crystallographic analysis of empty AAV5 viral capsids are reported. The crystals diffract X-rays to beyond 3.2 Å resolution using synchrotron radiation and belong to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 264.7, b = 447.9, c = 629.7 Å. There is one complete T = 1 viral capsid per asymmetric unit. The orientation and position of the viral capsid in the asymmetric unit have been determined by rotation and translation functions, respectively, and the AAV5 structure determination is in progress.

  3. Viral vectors and delivery strategies for CNS gene therapy

    PubMed Central

    Gray, Steven J; Woodard, Kenton T; Samulski, R Jude

    2015-01-01

    This review aims to provide a broad overview of the targets, challenges and potential for gene therapy in the CNS, citing specific examples. There are a broad range of therapeutic targets, with very different requirements for a suitable viral vector. By utilizing different vector tropisms, novel routes of administration and engineered promoter control, transgenes can be targeted to specific therapeutic applications. Viral vectors have proven efficacious in preclinical models for several disease applications, spurring several clinical trials. While the field has pushed the limits of existing adeno-associated virus-based vectors, a next generation of vectors based on rational engineering of viral capsids should expand the application of gene therapy to be more effective in specific therapeutic applications. PMID:22833965

  4. Prevalence of Anti–Adeno-Associated Virus Serotype 8 Neutralizing Antibodies and Arylsulfatase B Cross-Reactive Immunologic Material in Mucopolysaccharidosis VI Patient Candidates for a Gene Therapy Trial

    PubMed Central

    Ferla, Rita; Claudiani, Pamela; Savarese, Marco; Kozarsky, Karen; Parini, Rossella; Scarpa, Maurizio; Donati, Maria Alice; Sorge, Giovanni; Hopwood, John J.; Parenti, Giancarlo; Fecarotta, Simona; Nigro, Vincenzo; Sivri, Hatice Serap; Van Der Ploeg, Ans; Andria, Generoso; Brunetti-Pierri, Nicola

    2015-01-01

    Abstract Recombinant vectors based on adeno-associated virus serotype 8 (AAV8) have been successfully used in the clinic and hold great promise for liver-directed gene therapy. Preexisting immunity against AAV8 or the development of antibodies against the therapeutic transgene product might negatively affect the outcomes of gene therapy. In the prospect of an AAV8-mediated, liver-directed gene therapy clinical trial for mucopolysaccharidosis VI (MPS VI), a lysosomal storage disorder caused by arylsulfatase B (ARSB) deficiency, we investigated in a multiethnic cohort of MPS VI patients the prevalence of neutralizing antibodies (Nab) to AAV8 and the presence of ARSB cross-reactive immunologic material (CRIM), which will either affect the efficacy of gene transfer or the duration of phenotypic correction. Thirty-six MPS VI subjects included in the study harbored 45 (62.5%) missense, 13 (18%) nonsense, 9 (12.5%) frameshift (2 insertions and 7 deletions), and 5 (7%) splicing ARSB mutations. The detection of ARSB protein in 24 patients out of 34 (71%) was predicted by the type of mutations. Preexisting Nab to AAV8 were undetectable in 19/33 (58%) analyzed patients. Twelve out of 31 patients (39%) tested were both negative for Nab to AAV8 and CRIM-positive. In conclusion, this study allows estimating the number of MPS VI patients eligible for a gene therapy trial by intravenous injections of AAV8. PMID:25654180

  5. Modular adeno-associated virus (rAAV) vectors used for cellular virus-directed enzyme prodrug therapy.

    PubMed

    Hagen, Sven; Baumann, Tobias; Wagner, Hanna J; Morath, Volker; Kaufmann, Beate; Fischer, Adrian; Bergmann, Stefan; Schindler, Patrick; Arndt, Katja M; Müller, Kristian M

    2014-01-01

    The pre-clinical and clinical development of viral vehicles for gene transfer increased in recent years, and a recombinant adeno-associated virus (rAAV) drug took center stage upon approval in the European Union. However, lack of standardization, inefficient purification methods and complicated retargeting limit general usability. We address these obstacles by fusing rAAV-2 capsids with two modular targeting molecules (DARPin or Affibody) specific for a cancer cell-surface marker (EGFR) while simultaneously including an affinity tag (His-tag) in a surface-exposed loop. Equipping these particles with genes coding for prodrug converting enzymes (thymidine kinase or cytosine deaminase) we demonstrate tumor marker specific transduction and prodrug-dependent apoptosis of cancer cells. Coding terminal and loop modifications in one gene enabled specific and scalable purification. Our genetic parts for viral production adhere to a standardized cloning strategy facilitating rapid prototyping of virus directed enzyme prodrug therapy (VDEPT). PMID:24457557

  6. Recombinant adeno-associated virus type 2-mediated gene delivery into the Rpe65-/- knockout mouse eye results in limited rescue

    PubMed Central

    Lai, Chooi-May; Yu, Meaghan JT; Brankov, Meliha; Barnett, Nigel L; Zhou, Xiaohuai; Redmond, T Michael; Narfstrom, Kristina; Rakoczy, P Elizabeth

    2004-01-01

    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

  7. Adeno-associated virus mediated SOD gene therapy protects the retinal ganglion cells from chronic intraocular pressure elevation induced injury via attenuating oxidative stress and improving mitochondrial dysfunction in a rat model

    PubMed Central

    Jiang, Wenmin; Tang, Luosheng; Zeng, Jun; Chen, Baihua

    2016-01-01

    Purpose: This study aimed to determine whether chronic intraocular pressure (IOP) elevation induces retinal oxidative stress and alters mitochondrial morphology and function of retinal ganglion cells (RGC) and to explore the effects of AAV-SOD2 gene therapy on the RGC survival and mitochondrial dysfunction. Methods: Chronic experimental glaucoma was induced unilaterally in adult male Sprague-Dawley rats by laser burns at trabecular meshwork and episcleral veins 2 times with an interval of one week. One eye of each rat was intravitreally pretreated with recombinant adeno-associated virus expressing SOD2 (AAV-SOD2) or recombinant AAV expressing GFP (AAV-GFP) 21 days before glaucoma induction. RGCs counting, morphometric analysis of retina and optic nerve, and detection of activities of retinal SOD2 and catalase, MDA, mitochondrial morphology, mitochondrial dynamin protein OPA1 and DRP-1 expressions were conducted at 4, 8, 12 and 24 weeks. Results: Severe RGC loss, degeneration of optic nerve, reduced thickness of RGC layer and nerve fiber layer, significant decrease in total SOD and catalase activities, mitochondrial dysfunction and increased MDA were observed at 4, 8, 12 and 24 weeks after glaucoma. Pretreatment with AAV-SOD2 significantly reduced MDA and attenuated the damage to RGCs through a mitochondria-related pathway. Conclusion: AAV mediated pre-treatment with SOD2 is able to attenuate oxidative stress and improve mitochondrial dysfunction of RGC and optic nerve secondary to glaucoma. Thus, SOD2 may be used to prevent the retinal RGCs from glaucoma, which provides a promising strategy for glaucoma therapy. PMID:27158370

  8. Viral and nonviral delivery systems for gene delivery.

    PubMed

    Nayerossadat, Nouri; Maedeh, Talebi; Ali, Palizban Abas

    2012-01-01

    Gene therapy is the process of introducing foreign genomic materials into host cells to elicit a therapeutic benefit. Although initially the main focus of gene therapy was on special genetic disorders, now diverse diseases with different patterns of inheritance and acquired diseases are targets of gene therapy. There are 2 major categories of gene therapy, including germline gene therapy and somatic gene therapy. Although germline gene therapy may have great potential, because it is currently ethically forbidden, it cannot be used; however, to date human gene therapy has been limited to somatic cells. Although numerous viral and nonviral gene delivery systems have been developed in the last 3 decades, no delivery system has been designed that can be applied in gene therapy of all kinds of cell types in vitro and in vivo with no limitation and side effects. In this review we explain about the history of gene therapy, all types of gene delivery systems for germline (nuclei, egg cells, embryonic stem cells, pronuclear, microinjection, sperm cells) and somatic cells by viral [retroviral, adenoviral, adeno association, helper-dependent adenoviral systems, hybrid adenoviral systems, herpes simplex, pox virus, lentivirus, Epstein-Barr virus)] and nonviral systems (physical: Naked DNA, DNA bombardant, electroporation, hydrodynamic, ultrasound, magnetofection) and (chemical: Cationic lipids, different cationic polymers, lipid polymers). In addition to the above-mentioned, advantages, disadvantages, and practical use of each system are discussed. PMID:23210086

  9. Adeno-associated virus type 2 binding study on model heparan sulfate surface

    NASA Astrophysics Data System (ADS)

    Negishi, Atsuko; Liu, Jian; McCarty, Douglas; Samulski, Jude; Superfine, Richard

    2003-11-01

    Understanding the mechanisms involved in virus infections is useful in its application in areas such as gene therapy, drug development and delivery, and biosensors. In collaboration with UNC Gene Therapy Center and School of Pharmacy, we are specifically looking at the interaction between human parvovirus adeno-associated virus type 2 (AAV2), a potential viral vector, and heparan sulfate proteoglycan (HSPG), a known cell surface receptor for AAV2. Recent development in glycobiology has shown that some protein-polysaccharide binding is sugar sequence dependent. Heparan sulfate (HS) is a polysaccharide chain of sulfated iduronic/glucuronic and sulfate glucosamine residues and can be differentiated into sequence specific structures by enzymes. These enzymatic modifications, known as heparan sulfate sulfotransferase modified modifications, have been shown to change the biological nature of heparan sulfate such as specific binding to proteins and viruses. For understanding HS-assisted viral infection mechanisms, we are interested in investigating the binding affinity and stability of AAV to different HS structures. We have developed a model heparan sulfate surface in which AAV adsorption studies are done and analyzed using the atomic force microscope (AFM). In addition, a miniArray assay has been created to facilitate to this study. Adsorption studies are done in 4 white LED wells with approximately 3 mm2 reaction areas which minimize sample use and waste.

  10. Adeno-associated virus serotype 8 ApoA-I gene transfer reduces progression of atherosclerosis in ApoE-KO mice: comparison of intramuscular and intravenous administration.

    PubMed

    Cimmino, Giovanni; Giannarelli, Chiara; Chen, Wei; Alique, Matilde; Santos-Gallego, Carlos G; Fuster, Valentin; Hajjar, Roger J; Walsh, Christopher E; Badimon, Juan J

    2011-03-01

    Apolipoprotein A-I (ApoA-I)/high-density lipoprotein (HDL)-raising treatments are effective antiatherosclerotic strategies. We have compared the antiatherogenic effects of human ApoA-I (hApoA-I) overexpression by intraportal and intramuscular gene transfer in atherosclerotic ApoE-knockout mice. Atherosclerotic lesions were induced by atherogenic diet. After atherosclerosis induction, a group of animals was killed and served as atherosclerosis baseline-control group. The remaining animals were randomized into the following groups: (1) atherosclerosis-progression-control, (2) intraportal/vector administration, and (3) intramuscular/vector administration. Aortas and hearts were processed for atherosclerotic quantification by en face Sudan IV and Oil Red-O, respectively. Liver and muscle specimens were processed for protein/gene expression analysis. A sustained increase in hApoA-I/HDL plasma levels was observed in both transduced groups. hApoA-I overexpression abolished plaque progression versus progression-control group. hApoA-I overexpression significantly reduced lesion macrophage, feature indicative of plaque stabilization. Scavenger receptor class-B type I (SR-BI), but not ATP-binding cassette, sub-family A (ABCA), member 1 (ABCA-1), was significantly upregulated in treated groups versus progression-controls. The results of this study show a similar effect of hApoA-I/HDL overexpression on plaque progression/stabilization by 2 different routes of administration. Our results showing similar effects using either intramuscular administration and intraportal route of administration may have significant clinical implications, given the reduced medical risk to patient and cost of intramuscular injections. PMID:21164355

  11. Identification of the heparin binding site on adeno-associated virus serotype 3B (AAV-3B)

    SciTech Connect

    Lerch, Thomas F.; Chapman, Michael S.

    2012-05-24

    Adeno-associated virus is a promising vector for gene therapy. In the current study, the binding site on AAV serotype 3B for the heparan sulfate proteoglycan (HSPG) receptor has been characterized. X-ray diffraction identified a disaccharide binding site at the most positively charged region on the virus surface. The contributions of basic amino acids at this and other sites were characterized using site-directed mutagenesis. Both heparin and cell binding are correlated to positive charge at the disaccharide binding site, and transduction is significantly decreased in AAV-3B vectors mutated at this site to reduce heparin binding. While the receptor attachment sites of AAV-3B and AAV-2 are both in the general vicinity of the viral spikes, the exact amino acids that participate in electrostatic interactions are distinct. Diversity in the mechanisms of cell attachment by AAV serotypes will be an important consideration for the rational design of improved gene therapy vectors.

  12. Identification of the heparin binding site on adeno-associated virus serotype 3B (AAV-3B)

    SciTech Connect

    Lerch, Thomas F.; Chapman, Michael S.

    2012-02-05

    Adeno-associated virus is a promising vector for gene therapy. In the current study, the binding site on AAV serotype 3B for the heparan sulfate proteoglycan (HSPG) receptor has been characterized. X-ray diffraction identified a disaccharide binding site at the most positively charged region on the virus surface. The contributions of basic amino acids at this and other sites were characterized using site-directed mutagenesis. Both heparin and cell binding are correlated to positive charge at the disaccharide binding site, and transduction is significantly decreased in AAV-3B vectors mutated at this site to reduce heparin binding. While the receptor attachment sites of AAV-3B and AAV-2 are both in the general vicinity of the viral spikes, the exact amino acids that participate in electrostatic interactions are distinct. Diversity in the mechanisms of cell attachment by AAV serotypes will be an important consideration for the rational design of improved gene therapy vectors.

  13. Comparative analysis of cytotoxic T lymphocyte response induced by dendritic cells pulsed with recombinant adeno-associated virus carrying α-fetoprotein gene or cancer cell lysate.

    PubMed

    Zhou, Jun; Ma, Ping; Li, Jun; Song, Wei

    2015-04-01

    Hepatocellular carcinoma (HCC) is one of the most common and difficult to treat types of cancer worldwide. Antigen‑targeted immunotherapy has the potential to be a novel and effective adjuvant for use in HCC. In the present study, recombinant adeno‑associated virus carrying the α‑fetoprotein gene (rAAV/AFP) and cancer cell lysates were used to pulse antigen‑presenting dendritic cells (DCs) in order to stimulate a cytotoxic T lymphocyte (CTL) response against HCC. rAAV/AFP‑pulsed and cancer cell lysate‑pulsed DCs resulted in a mature DC phenotype with high expression of major histocompatibility complex (MHC) class I, MHC class II, CD80, CD83 and CD86 molecules. However, rAAV/AFP‑pulsed DCs exhibited superiority over cancer cell lysate‑pulsed DCs in terms of stimulating proliferation of T cells, activating T cells to secret interferon‑γ (IFN‑γ) and inducing an AFP‑specific MHC class I‑restricted CTL response. The current data suggest that pulsing of DCs using rAAV/AFP is more effective than the cancer cell lysate‑pulsing technique, and that this technique may be used for the development of immunotherapy in AFP‑positive HCC. PMID:25484119

  14. Site-specific integration of adeno-associated virus involves partial duplication of the target locus

    PubMed Central

    Henckaerts, Els; Dutheil, Nathalie; Zeltner, Nadja; Kattman, Steven; Kohlbrenner, Erik; Ward, Peter; Clément, Nathalie; Rebollo, Patricia; Kennedy, Marion; Keller, Gordon M.; Linden, R. Michael

    2009-01-01

    A variety of viruses establish latency by integrating their genome into the host genome. The integration event generally occurs in a nonspecific manner, precluding the prediction of functional consequences from resulting disruptions of affected host genes. The nonpathogenic adeno-associated virus (AAV) is unique in its ability to stably integrate in a site-specific manner into the human MBS85 gene. To gain a better understanding of the integration mechanism and the consequences of MBS85 disruption, we analyzed the molecular structure of AAV integrants in various latently infected human cell lines. Our study led to the observation that AAV integration causes an extensive but partial duplication of the target gene. Intriguingly, the molecular organization of the integrant leaves the possibility that a functional copy of the disrupted target gene could potentially be preserved despite the resulting rearrangements. A latently infected, Mbs85-targeted mouse ES cell line was generated to study the functional consequences of the observed duplication-based integration mechanism. AAV-modified ES cell lines continued to self-renew, maintained their multilineage differentiation potential and contributed successfully to mouse development when injected into blastocysts. Thus, our study reveals a viral strategy for targeted genome addition with the apparent absence of functional consequences. PMID:19372372

  15. Viral Vectors for Gene Delivery to the Central Nervous System

    PubMed Central

    Lentz, Thomas B.; Gray, Steven J.; Samulski, R. Jude

    2011-01-01

    The potential benefits of gene therapy for neurological diseases such as Parkinson’s, Amyotrophic Lateral Sclerosis (ALS), Epilepsy, and Alzheimer’s are enormous. Even a delay in the onset of severe symptoms would be invaluable to patients suffering from these and other diseases. Significant effort has been placed in developing vectors capable of delivering therapeutic genes to the CNS in order to treat neurological disorders. At the forefront of potential vectors, viral systems have evolved to efficiently deliver their genetic material to a cell. The biology of different viruses offers unique solutions to the challenges of gene therapy, such as cell targeting, transgene expression and vector production. It is important to consider the natural biology of a vector when deciding whether it will be the most effective for a specific therapeutic function. In this review, we outline desired features of the ideal vector for gene delivery to the CNS and discuss how well available viral vectors compare to this model. Adeno-associated virus, retrovirus, adenovirus and herpesvirus vectors are covered. Focus is placed on features of the natural biology that have made these viruses effective tools for gene delivery with emphasis on their application in the CNS. Our goal is to provide insight into features of the optimal vector and which viral vectors can provide these features. PMID:22001604

  16. Employing a Gain-of-Function Factor IX Variant R338L to Advance the Efficacy and Safety of Hemophilia B Human Gene Therapy: Preclinical Evaluation Supporting an Ongoing Adeno-Associated Virus Clinical Trial

    PubMed Central

    Sun, Junjiang; Gui, Tong; Hu, Genlin; Hannah, William B.; Wichlan, David G.; Wu, Zhijian; Grieger, Joshua C.; Li, Chengwen; Suwanmanee, Thipparat; Stafford, Darrel W.; Booth, Carmen J.; Samulski, Jade J.; Kafri, Tal; McPhee, Scott W.J.

    2015-01-01

    Abstract Vector capsid dose-dependent inflammation of transduced liver has limited the ability of adeno-associated virus (AAV) factor IX (FIX) gene therapy vectors to reliably convert severe to mild hemophilia B in human clinical trials. These trials also identified the need to understand AAV neutralizing antibodies and empty AAV capsids regarding their impact on clinical success. To address these safety concerns, we have used a scalable manufacturing process to produce GMP-grade AAV8 expressing the FIXR338L gain-of-function variant with minimal (<10%) empty capsid and have performed comprehensive dose–response, biodistribution, and safety evaluations in clinically relevant hemophilia models. The scAAV8.FIXR338L vector produced greater than 6-fold increased FIX specific activity compared with wild-type FIX and demonstrated linear dose responses from doses that produced 2–500% FIX activity, associated with dose-dependent hemostasis in a tail transection bleeding challenge. More importantly, using a bleeding model that closely mimics the clinical morbidity of hemophilic arthropathy, mice that received the scAAV8.FIXR338L vector developed minimal histopathological findings of synovitis after hemarthrosis, when compared with mice that received identical doses of wild-type FIX vector. Hemostatically normal mice (n=20) and hemophilic mice (n=88) developed no FIX antibodies after peripheral intravenous vector delivery. No CD8+ T cell liver infiltrates were observed, despite the marked tropism of scAAV8.FIXR338L for the liver in a comprehensive biodistribution evaluation (n=60 animals). With respect to the role of empty capsids, we demonstrated that in vivo FIXR338L expression was not influenced by the presence of empty AAV particles, either in the presence or absence of various titers of AAV8-neutralizing antibodies. Necropsy of FIX–/– mice 8–10 months after vector delivery revealed no microvascular or macrovascular thrombosis in mice expressing FIXR338L (plasma

  17. Employing a gain-of-function factor IX variant R338L to advance the efficacy and safety of hemophilia B human gene therapy: preclinical evaluation supporting an ongoing adeno-associated virus clinical trial.

    PubMed

    Monahan, Paul E; Sun, Junjiang; Gui, Tong; Hu, Genlin; Hannah, William B; Wichlan, David G; Wu, Zhijian; Grieger, Joshua C; Li, Chengwen; Suwanmanee, Thipparat; Stafford, Darrel W; Booth, Carmen J; Samulski, Jade J; Kafri, Tal; McPhee, Scott W J; Samulski, R Jude

    2015-02-01

    Vector capsid dose-dependent inflammation of transduced liver has limited the ability of adeno-associated virus (AAV) factor IX (FIX) gene therapy vectors to reliably convert severe to mild hemophilia B in human clinical trials. These trials also identified the need to understand AAV neutralizing antibodies and empty AAV capsids regarding their impact on clinical success. To address these safety concerns, we have used a scalable manufacturing process to produce GMP-grade AAV8 expressing the FIXR338L gain-of-function variant with minimal (<10%) empty capsid and have performed comprehensive dose-response, biodistribution, and safety evaluations in clinically relevant hemophilia models. The scAAV8.FIXR338L vector produced greater than 6-fold increased FIX specific activity compared with wild-type FIX and demonstrated linear dose responses from doses that produced 2-500% FIX activity, associated with dose-dependent hemostasis in a tail transection bleeding challenge. More importantly, using a bleeding model that closely mimics the clinical morbidity of hemophilic arthropathy, mice that received the scAAV8.FIXR338L vector developed minimal histopathological findings of synovitis after hemarthrosis, when compared with mice that received identical doses of wild-type FIX vector. Hemostatically normal mice (n=20) and hemophilic mice (n=88) developed no FIX antibodies after peripheral intravenous vector delivery. No CD8(+) T cell liver infiltrates were observed, despite the marked tropism of scAAV8.FIXR338L for the liver in a comprehensive biodistribution evaluation (n=60 animals). With respect to the role of empty capsids, we demonstrated that in vivo FIXR338L expression was not influenced by the presence of empty AAV particles, either in the presence or absence of various titers of AAV8-neutralizing antibodies. Necropsy of FIX(-/-) mice 8-10 months after vector delivery revealed no microvascular or macrovascular thrombosis in mice expressing FIXR338L (plasma FIX activity

  18. Identification of a Functionally Relevant Adeno-Associated Virus Rep68 Oligomeric Interface

    PubMed Central

    Bardelli, Martino; Zárate-Pérez, Francisco; Agúndez, Leticia; Linden, R. Michael

    2016-01-01

    ABSTRACT The life cycle of the human parvovirus adeno-associated virus (AAV) is orchestrated by four Rep proteins. The large Rep proteins, Rep78 and Rep68, are remarkably multifunctional and display a range of biochemical activities, including DNA binding, nicking, and unwinding. Functionally, Rep78 and Rep68 are involved in transcriptional regulation, DNA replication, and genomic integration. Structurally, the Rep proteins share an AAA+ domain characteristic of superfamily 3 helicases, with the large Rep proteins additionally containing an N-terminal origin-binding domain (OBD) that specifically binds and nicks DNA. The combination of these domains, coupled with dynamic oligomerization properties, is the basis for the remarkable multifunctionality displayed by Rep68 and Rep78 during the AAV life cycle. In this report, we describe an oligomeric interface formed by Rep68 and demonstrate how disruption of this interface has drastic effects on both the oligomerization and functionality of the Rep proteins. Our results support a role for the four-helix bundle in the helicase domain of Rep68 as a bona fide oligomerization domain (OD). We have identified key residues in the OD that are critical for the stabilization of the Rep68-Rep68 interface; mutation of these key residues disrupts the enzymatic activities of Rep68, including DNA binding and nicking, and compromises viral DNA replication and transcriptional regulation of the viral promoters. Taken together, our data contribute to our understanding of the dynamic and substrate-responsive Rep78/68 oligomerization that is instrumental in the regulation of the DNA transitions that take place during the AAV life cycle. IMPORTANCE The limited genome size of small viruses has driven the evolution of highly multifunctional proteins that integrate different domains and enzymatic activities within a single polypeptide. The Rep68 protein from adeno-associated virus (AAV) combines a DNA binding and endonuclease domain with a

  19. Adeno-associated Virus-mediated Rescue of Neonatal Lethality in Argininosuccinate Synthetase-deficient Mice

    PubMed Central

    Kok, Cindy Y; Cunningham, Sharon C; Carpenter, Kevin H; Dane, Allison P; Siew, Susan M; Logan, Grant J; Kuchel, Philip W; Alexander, Ian E

    2013-01-01

    Viral vectors based on adeno-associated virus (AAV) are showing exciting promise in gene therapy trials targeting the adult liver. A major challenge in extending this promise to the pediatric liver is the loss of episomal vector genomes that accompanies hepatocellular proliferation during liver growth. Hence maintenance of sufficient transgene expression will be critical for success in infants and children. We therefore set out to explore the therapeutic efficacy and durability of liver-targeted gene transfer in the challenging context of a neonatal lethal urea cycle defect, using the argininosuccinate synthetase deficient mouse. Lethal neonatal hyperammonemia was prevented by prenatal and early postnatal vector delivery; however, hyperammonemia subsequently recurred limiting survival to no more than 33 days despite vector readministration. Antivector antibodies acquired in milk from vector-exposed dams were subsequently shown to be blocking vector readministration, and were avoided by crossfostering vector-treated pups to vector-naive dams. In the absence of passively acquired antivector antibodies, vector redelivery proved efficacious with mice surviving to adulthood without recurrence of significant hyperammonemia. These data demonstrate the potential of AAV vectors in the developing liver, showing that vector readministration can be used to counter growth-associated loss of transgene expression provided the challenge of antivector humoral immunity is addressed. PMID:23817206

  20. Super-resolution imaging of nuclear import of adeno-associated virus in live cells.

    PubMed

    Kelich, Joseph M; Ma, Jiong; Dong, Biao; Wang, Qizhao; Chin, Mario; Magura, Connor M; Xiao, Weidong; Yang, Weidong

    2015-01-01

    Adeno-associated virus (AAV) has been developed as a promising human gene therapy vector. Particularly, recombinant AAV vector (rAAV) achieves its transduction of host cells by crossing at least three physiological barriers including plasma membrane, endosomal membrane, and nuclear envelope (NE). So far, the AAV transduction mechanism has not been explored thoroughly at the single viral particle level. In this study, we employed high-speed super-resolution single-point edge-excitation sub-diffraction (SPEED) microscopy to map the events of single rAAV2 particles infecting live human cells with an unprecedented spatiotemporal resolution of 9-12 nm and 2-20 ms. Data reveal that rAAV2 particles are imported through nuclear pore complexes (NPCs) rather than nuclear membrane budding into the nucleus. Moreover, approximately 17% of the rAAV2 molecules starting from the cytoplasm successfully transverse the NPCs to reach the nucleoplasm, revealing that the NPCs act as a strict selective step for AAV delivery. This study lastly suggests a new pathway to improve AAV vectors for human gene therapy. PMID:26665132

  1. Super-resolution imaging of nuclear import of adeno-associated virus in live cells

    PubMed Central

    Kelich, Joseph M; Ma, Jiong; Dong, Biao; Wang, Qizhao; Chin, Mario; Magura, Connor M; Xiao, Weidong; Yang, Weidong

    2015-01-01

    Adeno-associated virus (AAV) has been developed as a promising human gene therapy vector. Particularly, recombinant AAV vector (rAAV) achieves its transduction of host cells by crossing at least three physiological barriers including plasma membrane, endosomal membrane, and nuclear envelope (NE). So far, the AAV transduction mechanism has not been explored thoroughly at the single viral particle level. In this study, we employed high-speed super-resolution single-point edge-excitation sub-diffraction (SPEED) microscopy to map the events of single rAAV2 particles infecting live human cells with an unprecedented spatiotemporal resolution of 9–12 nm and 2–20 ms. Data reveal that rAAV2 particles are imported through nuclear pore complexes (NPCs) rather than nuclear membrane budding into the nucleus. Moreover, approximately 17% of the rAAV2 molecules starting from the cytoplasm successfully transverse the NPCs to reach the nucleoplasm, revealing that the NPCs act as a strict selective step for AAV delivery. This study lastly suggests a new pathway to improve AAV vectors for human gene therapy. PMID:26665132

  2. Ultrasound Targeted Microbubble Destruction Stimulates Cellular Endocytosis in Facilitation of Adeno-Associated Virus Delivery

    PubMed Central

    Jin, Li-Fang; Li, Fan; Wang, Hui-Ping; Wei, Fang; Qin, Peng; Du, Lian-Fang

    2013-01-01

    The generally accepted mechanism for ultrasound targeted microbubble destruction (UTMD) to enhance drug and gene delivery is through sonoporation. However, passive uptake of adeno-associated virus (AAV) into cells following sonoporation does not adequately explain observations of enhanced transduction by UTMD. This study investigated alternative mechanisms of UTMD enhancement in AAV delivery. UTMD significantly enhanced transduction efficiency of AAV in a dose-dependent manner. UTMD stimulated a persistent uptake of AAV into the cytoplasm and nucleus. This phenomenon occurred over several hours, suggesting that some viral particles are endocytosed by cells rather than exclusively passing through pores created by sonoporation. Additionally, UTMD enhanced clathrin expression and accumulation at the plasma membrane suggesting greater clathrin-mediated endocytosis following UTMD. Transmission electron microscopy (TEM) revealed that UTMD stimulated formation of clathrin-coated pits (CPs) and uncoated pits (nCPs). Furthermore, inhibition of clathrin-mediated endocytosis partially blocked the enhancement of AAV uptake following UTMD. The results of this study implicate endocytosis as a mechanism that contributes to UTMD-enhanced AAV delivery. PMID:23652832

  3. Analysis of mutations in adeno-associated virus Rep protein in vivo and in vitro.

    PubMed Central

    McCarty, D M; Ni, T H; Muzyczka, N

    1992-01-01

    The adeno-associated virus (AAV) Rep protein is required for both viral DNA replication and transactivation of the AAV promoters. Here we report the effects of mutations in the rep gene on transcription and replication in vivo and terminal repeat binding and terminal resolution site (trs) endonuclease activities in vitro. In all, we examined 10 in-frame deletions and 14 amino acid substitution mutations at eight positions. The point mutations were targeted to regions that are highly conserved among the parvovirus nonstructural proteins and include the extended ATPase domain of the AAV Rep protein. The mutations identify at least two noncontiguous regions of Rep which are essential for terminal repeat binding (amino acids 134 to 242 and amino acids 415 to 490). Mutations in either region render the protein inactive for both DNA replication and transactivation. In addition, mutations within a putative ATPase region also cause defects in replication and transactivation in vivo as well as in the ATP-dependent trs endonuclease activity in vitro. These results suggest that Rep transactivates via a novel mechanism which may require both DNA binding and an enzymatic activity, namely, ATPase or DNA helicase activity. Images PMID:1318396

  4. Antitumor effect and biological pathways of a recombinant adeno-associated virus as a human renal cell carcinoma suppressor.

    PubMed

    Chen, Jie; Ruan, Xiyun; Wang, Shaomei; Zhang, Bin; Liu, Bo; Sun, Zeqiang; Liu, Qingyong

    2014-11-01

    The aims of this work are to study the antitumor effect of the adeno-associated virus on the xenografted tumors of chick embryo chorioallantoic membrane and predict potential genes and biological pathways which are associated with renal cell carcinoma. The adeno-associated virus NT4-TAT-6 × His-VHLbeta was constructed and identified. Then, chick embryos with xenografted tumor were divided into three groups and respectively inoculated with rAAV/NT4-TAT-6 × His-VHLbeta (group A), empty virus (group B), and phosphate-buffered saline (group C, the control subject). Antitumor effect in each group was investigated by means of immunofluorescence observation. Genes interacted with von Hippel-Lindau were screened by Search Tool for the Retrieval of Interacting Genes/Proteins database, while pathway analysis were performed based on Kyoto Encyclopedia of Genes and Genomes. The growth of xenografted tumors inoculated with recombinant adeno-associated virus was slower than the control subjects. The tumor volumes of group A showed significant difference compared with group B and group C (P < 0.05). Growth of xenografted tumors which administered with the recombinant adeno-associated virus was inhibited. Among the protein-protein interaction network, TCEB2, HIF1A, TCEB1, CUL2, RBX1, and PHF17 were hub genes which might be involved in the development of renal cell carcinoma. The most significant signaling pathway was renal cell carcinoma. In this paper, we constructed and identified the recombinant adeno-associated virus NT4-TAT-6 × His-VHLbeta and studied the antitumor effect of the adeno-associated virus on xenografted tumors of chicken embryo chorioallantoic membrane. In addition, genes in the protein-protein interaction network which are associated with renal cell carcinoma were revealed and the biological pathway of renal cell carcinoma was identified. Our results provide a gene-therapeutic agent for the treatment of human renal cell carcinoma. PMID:25091575

  5. Differential Cellular Tropism of Lentivirus and Adeno-Associated Virus in the Brain of Cynomolgus Monkey

    PubMed Central

    An, Heeyoung; Cho, Doo-Wan; Lee, Seung Eun; Yang, Young-Su

    2016-01-01

    Many researchers are using viruses to deliver genes of interest into the brains of laboratory animals. However, certain target brain cells are not easily infected by viruses. Moreover, the differential tropism of different viruses in monkey brain is not well established. We investigated the cellular tropism of lentivirus and adeno-associated virus (AAV) toward neuron and glia in the brain of cynomolgus monkeys (Macaca fascularis). Lentivirus and AAV were injected into putamen of the monkey brain. One month after injection, monkeys were sacrificed, and then the presence of viral infection by expression of reporter fluorescence proteins was examined. Tissues were sectioned and stained with NeuN and GFAP antibodies for identifying neuronal cells or astrocytes, respectively, and viral reporter GFP-expressing cells were counted. We found that while lentivirus infected mostly astrocytes, AAV infected neurons at a higher rate than astrocytes. Moreover, astrocytes showed reactiveness when cells were infected by virus, likely due to virus-mediated neuroinflammation. The Sholl analysis was done to compare the hypertrophy of infected and uninfected astrocytes by virus. The lentivirus infected astrocytes showed negligible hypertrophy whereas AAV infected astrocytes showed significant changes in morphology, compared to uninfected astrocytes. In the brain of cynomolgus monkey, lentivirus shows tropism for astrocytes over neurons without much reactivity in astrocytes, whereas AAV shows tropism for neurons over glial cells with a significant reactivity in astrocytes. We conclude that AAV is best-suited for gene delivery to neurons, whereas lentivirus is the best choice for gene delivery to astrocytes in the brain of cynomolgus monkeys. PMID:26924933

  6. Production, Purification, Crystallization and Preliminary X-ray Structural Studies of Adeno-Associated Virus Serotype 5

    SciTech Connect

    DiMattia,M.; Govindasamy, L.; Levy, H.; Whitaker-Gurda, B.; Kohlbrenner, E.; Chiorini, J.; McKenna, R.; Muzyczka, N.; Zolotukhin, S.; Agbandje-McKenna, M.

    2005-01-01

    Adeno-associated virus serotype 5 (AAV5) is under development for gene-therapy applications for the treatment of cystic fibrosis. To elucidate the structural features of AAV5 that control its enhanced transduction of the apical surface of airway epithelia compared with other AAV serotypes, X-ray crystallographic studies of the viral capsid have been initiated. The production, purification, crystallization and preliminary crystallographic analysis of empty AAV5 viral capsids are reported. The crystals diffract X-rays to beyond 3.2 Angstroms resolution using synchrotron radiation and belong to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 264.7, b = 447.9, c = 629.7 Angstroms. There is one complete T = 1 viral capsid per asymmetric unit. The orientation and position of the viral capsid in the asymmetric unit have been determined by rotation and translation functions, respectively, and the AAV5 structure determination is in progress.

  7. In silico reconstruction of the viral evolutionary lineage yields a potent gene therapy vector

    PubMed Central

    Zinn, Eric; Pacouret, Simon; Khaychuk, Vadim; Turunen, Heikki T.; Carvalho, Livia S.; Andres-Mateos, Eva; Shah, Samiksha; Shelke, Rajani; Maurer, Anna C.; Plovie, Eva; Xiao, Ru; Vandenberghe, Luk H.

    2015-01-01

    SUMMARY Adeno-associated viral vectors (AAV) have emerged as a gene delivery platform with demonstrated safety and efficacy in a handful of clinical trials for monogenic disorders. However, limitations of the current generation vectors often prevent broader application of AAV gene therapy. Efforts to engineer AAV have been hampered by a limited understanding of the structure-function relationship of the complex multimeric icosahedral architecture of the particle. To develop additional reagents pertinent to further our insight into AAV, we inferred evolutionary intermediates of the viral capsid using ancestral sequence reconstruction. In silico derived sequences were synthesized de novo and characterized for biological properties relevant to clinical applications. This effort led to the generation of 9 functional putative ancestral AAVs and the identification of Anc80, the predicted ancestor of the widely studied AAV serotypes 1, 2, 8 and 9 as a highly potent in vivo gene therapy vector for targeting liver, muscle, and retina. PMID:26235624

  8. Rational plasmid design and bioprocess optimization to enhance recombinant adeno-associated virus (AAV) productivity in mammalian cells.

    PubMed

    Emmerling, Verena V; Pegel, Antje; Milian, Ernest G; Venereo-Sanchez, Alina; Kunz, Marion; Wegele, Jessica; Kamen, Amine A; Kochanek, Stefan; Hoerer, Markus

    2016-02-01

    Viral vectors used for gene and oncolytic therapy belong to the most promising biological products for future therapeutics. Clinical success of recombinant adeno-associated virus (rAAV) based therapies raises considerable demand for viral vectors, which cannot be met by current manufacturing strategies. Addressing existing bottlenecks, we improved a plasmid system termed rep/cap split packaging and designed a minimal plasmid encoding adenoviral helper function. Plasmid modifications led to a 12-fold increase in rAAV vector titers compared to the widely used pDG standard system. Evaluation of different production approaches revealed superiority of processes based on anchorage- and serum-dependent HEK293T cells, exhibiting about 15-fold higher specific and volumetric productivity compared to well-established suspension cells cultivated in serum-free medium. As for most other viral vectors, classical stirred-tank bioreactor production is thus still not capable of providing drug product of sufficient amount. We show that manufacturing strategies employing classical surface-providing culture systems can be successfully transferred to the new fully-controlled, single-use bioreactor system Integrity(TM) iCELLis(TM) . In summary, we demonstrate substantial bioprocess optimizations leading to more efficient and scalable production processes suggesting a promising way for flexible large-scale rAAV manufacturing. PMID:26284700

  9. Structure of neurotropic adeno-associated virus AAVrh.8.

    PubMed

    Halder, Sujata; Van Vliet, Kim; Smith, J Kennon; Duong, Thao Thi Phuong; McKenna, Robert; Wilson, James M; Agbandje-McKenna, Mavis

    2015-10-01

    Adeno-associated virus rhesus isolate 8 (AAVrh.8) is a leading vector for the treatment of neurological diseases due to its efficient transduction of neuronal cells and reduced peripheral tissue tropism. Toward identification of the capsid determinants for these properties, the structure of AAVrh.8 was determined by X-ray crystallography to 3.5 Å resolution and compared to those of other AAV isolates. The capsid viral protein (VP) structure consists of an αA helix and an eight-stranded anti-parallel β-barrel core conserved in parvoviruses, and large insertion loop regions between the β-strands form the capsid surface topology. The AAVrh.8 capsid exhibits the surface topology conserved in all AAVs: depressions at the icosahedral twofold axis and surrounding the cylindrical channel at the fivefold axis, and three protrusions around the threefold axis. A structural comparison to serotypes AAV2, AAV8, and AAV9, to which AAVrh.8 shares ∼ 84%, ∼ 91%, and ∼ 87% VP sequence identity, respectively, revealed differences in the surface loops known to affect receptor binding, transduction efficiency, and antigenicity. Consistent with this observation, biochemical assays showed that AAVrh.8 is unable to bind heparin and does not cross-react with conformational monoclonal antibodies and human donor serum directed against the other AAVs compared. This structure of AAVrh.8 thus identified capsid surface differences which can serve as template regions for rational design of vectors with enhanced transduction for specific tissues and escape pre-existing antibody recognition. These features are essential for the creation of an AAV vector toolkit that is amenable to personalized disease treatment. PMID:26334681

  10. An essential receptor for adeno-associated virus infection.

    PubMed

    Pillay, S; Meyer, N L; Puschnik, A S; Davulcu, O; Diep, J; Ishikawa, Y; Jae, L T; Wosen, J E; Nagamine, C M; Chapman, M S; Carette, J E

    2016-02-01

    Adeno-associated virus (AAV) vectors are currently the leading candidates for virus-based gene therapies because of their broad tissue tropism, non-pathogenic nature and low immunogenicity. They have been successfully used in clinical trials to treat hereditary diseases such as haemophilia B (ref. 2), and have been approved for treatment of lipoprotein lipase deficiency in Europe. Considerable efforts have been made to engineer AAV variants with novel and biomedically valuable cell tropisms to allow efficacious systemic administration, yet basic aspects of AAV cellular entry are still poorly understood. In particular, the protein receptor(s) required for AAV entry after cell attachment remains unknown. Here we use an unbiased genetic screen to identify proteins essential for AAV serotype 2 (AAV2) infection in a haploid human cell line. The most significantly enriched gene of the screen encodes a previously uncharacterized type I transmembrane protein, KIAA0319L (denoted hereafter as AAV receptor (AAVR)). We characterize AAVR as a protein capable of rapid endocytosis from the plasma membrane and trafficking to the trans-Golgi network. We show that AAVR directly binds to AAV2 particles, and that anti-AAVR antibodies efficiently block AAV2 infection. Moreover, genetic ablation of AAVR renders a wide range of mammalian cell types highly resistant to AAV2 infection. Notably, AAVR serves as a critical host factor for all tested AAV serotypes. The importance of AAVR for in vivo gene delivery is further highlighted by the robust resistance of Aavr(-/-) (also known as Au040320(-/-) and Kiaa0319l(-/-)) mice to AAV infection. Collectively, our data indicate that AAVR is a universal receptor involved in AAV infection. PMID:26814968

  11. Cloning and characterization of a bovine adeno-associated virus.

    PubMed

    Schmidt, Michael; Katano, Hisako; Bossis, Ioannis; Chiorini, John A

    2004-06-01

    To better understand the relationship between primate adeno-associated viruses (AAVs) and those of other mammals, we have cloned and sequenced the genome of an AAV found as a contaminant in two isolates of bovine adenovirus that was reported to be serologically distinct from primate AAVs. The bovine AAV (BAAV) genome has 4,693 bp, and its organization is similar to that of other AAV isolates. The left-hand open reading frame (ORF) and both inverted terminal repeats (ITRs) have the highest homology with the rep ORF and ITRs of AAV serotype 5 (AAV-5) (89 and 96%, respectively). However, the right-hand ORF was only 55% identical to the AAV-5 capsid ORF; it had the highest homology with the capsid ORF of AAV-4 (76%). By comparing the BAAV cap sequence with a model of an AAV-4 capsid, we mapped the regions of BAAV VP1 that are divergent from AAV-4. These regions are located on the outside of the capsid and are partially located in exposed loops. BAAV was not neutralized by antisera raised against recombinant AAV-2, AAV-4, or AAV-5, and it demonstrated a unique cell tropism profile in four human cancer cell lines, suggesting that BAAV might have transduction activity distinct from that of other isolates. A murine model of salivary gland gene transfer was used to evaluate the in vivo performance of recombinant BAAV. Recombinant BAAV-mediated gene transfer was 11 times more efficient than that with AAV-2. Overall, these data suggest that vectors based on BAAV could be useful for gene transfer applications. PMID:15163744

  12. Syntaxin 5-Dependent Retrograde Transport to the trans-Golgi Network Is Required for Adeno-Associated Virus Transduction

    PubMed Central

    Nonnenmacher, Mathieu E.; Cintrat, Jean-Christophe; Gillet, Daniel

    2014-01-01

    ABSTRACT Intracellular transport of recombinant adeno-associated virus (AAV) is still incompletely understood. In particular, the trafficking steps preceding the release of incoming AAV particles from the endosomal system into the cytoplasm, allowing subsequent nuclear import and the initiation of gene expression, remain to be elucidated fully. Others and we previously showed that a significant proportion of viral particles are transported to the Golgi apparatus and that Golgi apparatus disruption caused by the drug brefeldin A efficiently blocks AAV serotype 2 (AAV2) transduction. However, because brefeldin A is known to exert pleiotropic effects on the entire endosomal system, the functional relevance of transport to the Golgi apparatus for AAV transduction remains to be established definitively. Here, we show that AAV2 trafficking toward the trans-Golgi network (TGN) and the Golgi apparatus correlates with transduction efficiency and relies on a nonclassical retrograde transport pathway that is independent of the retromer complex, late endosomes, and recycling endosomes. AAV2 transduction is unaffected by the knockdown of syntaxins 6 and 16, which are two major effectors in the retrograde transport of both exogenous and endogenous cargo. On the other hand, inhibition of syntaxin 5 function by small interfering RNA silencing or treatment with cyclized Retro-2 strongly decreases AAV2 transduction and transport to the Golgi apparatus. This inhibition of transduction is observed with several AAV serotypes and a number of primary and immortalized cells. Together, our data strongly suggest that syntaxin 5-mediated retrograde transport to the Golgi apparatus is a broadly conserved feature of AAV trafficking that appears to be independent of the identity of the receptors used for viral attachment. IMPORTANCE Gene therapy constitutes a promising approach for the treatment of life-threatening conditions refractory to any other form of remedy. Adeno-associated virus (AAV

  13. Current gene therapy using viral vectors for chronic pain.

    PubMed

    Guedon, Jean-Marc G; Wu, Shaogen; Zheng, Xuexing; Churchill, Caroline C; Glorioso, Joseph C; Liu, Ching-Hang; Liu, Shue; Vulchanova, Lucy; Bekker, Alex; Tao, Yuan-Xiang; Kinchington, Paul R; Goins, William F; Fairbanks, Carolyn A; Hao, Shuanglin

    2015-01-01

    The complexity of chronic pain and the challenges of pharmacotherapy highlight the importance of development of new approaches to pain management. Gene therapy approaches may be complementary to pharmacotherapy for several advantages. Gene therapy strategies may target specific chronic pain mechanisms in a tissue-specific manner. The present collection of articles features distinct gene therapy approaches targeting specific mechanisms identified as important in the specific pain conditions. Dr. Fairbanks group describes commonly used gene therapeutics (herpes simplex viral vector (HSV) and adeno-associated viral vector (AAV)), and addresses biodistribution and potential neurotoxicity in pre-clinical models of vector delivery. Dr. Tao group addresses that downregulation of a voltage-gated potassium channel (Kv1.2) contributes to the maintenance of neuropathic pain. Alleviation of chronic pain through restoring Kv1.2 expression in sensory neurons is presented in this review. Drs Goins and Kinchington group describes a strategy to use the replication defective HSV vector to deliver two different gene products (enkephalin and TNF soluble receptor) for the treatment of post-herpetic neuralgia. Dr. Hao group addresses the observation that the pro-inflammatory cytokines are an important shared mechanism underlying both neuropathic pain and the development of opioid analgesic tolerance and withdrawal. The use of gene therapy strategies to enhance expression of the anti-pro-inflammatory cytokines is summarized. Development of multiple gene therapy strategies may have the benefit of targeting specific pathologies associated with distinct chronic pain conditions (by Guest Editors, Drs. C. Fairbanks and S. Hao). PMID:25962909

  14. Safe and bodywide muscle transduction in young adult Duchenne muscular dystrophy dogs with adeno-associated virus.

    PubMed

    Yue, Yongping; Pan, Xiufang; Hakim, Chady H; Kodippili, Kasun; Zhang, Keqing; Shin, Jin-Hong; Yang, Hsiao T; McDonald, Thomas; Duan, Dongsheng

    2015-10-15

    The ultimate goal of muscular dystrophy gene therapy is to treat all muscles in the body. Global gene delivery was demonstrated in dystrophic mice more than a decade ago using adeno-associated virus (AAV). However, translation to affected large mammals has been challenging. The only reported attempt was performed in newborn Duchenne muscular dystrophy (DMD) dogs. Unfortunately, AAV injection resulted in growth delay, muscle atrophy and contracture. Here we report safe and bodywide AAV delivery in juvenile DMD dogs. Three ∼2-m-old affected dogs received intravenous injection of a tyrosine-engineered AAV-9 reporter or micro-dystrophin (μDys) vector at the doses of 1.92-6.24 × 10(14) viral genome particles/kg under transient or sustained immune suppression. DMD dogs tolerated injection well and their growth was not altered. Hematology and blood biochemistry were unremarkable. No adverse reactions were observed. Widespread muscle transduction was seen in skeletal muscle, the diaphragm and heart for at least 4 months (the end of the study). Nominal expression was detected in internal organs. Improvement in muscle histology was observed in μDys-treated dogs. In summary, systemic AAV gene transfer is safe and efficient in young adult dystrophic large mammals. This may translate to bodywide gene therapy in pediatric patients in the future. PMID:26264580

  15. In Silico Reconstruction of the Viral Evolutionary Lineage Yields a Potent Gene Therapy Vector.

    PubMed

    Zinn, Eric; Pacouret, Simon; Khaychuk, Vadim; Turunen, Heikki T; Carvalho, Livia S; Andres-Mateos, Eva; Shah, Samiksha; Shelke, Rajani; Maurer, Anna C; Plovie, Eva; Xiao, Ru; Vandenberghe, Luk H

    2015-08-11

    Adeno-associated virus (AAV) vectors have emerged as a gene-delivery platform with demonstrated safety and efficacy in a handful of clinical trials for monogenic disorders. However, limitations of the current generation vectors often prevent broader application of AAV gene therapy. Efforts to engineer AAV vectors have been hampered by a limited understanding of the structure-function relationship of the complex multimeric icosahedral architecture of the particle. To develop additional reagents pertinent to further our insight into AAVs, we inferred evolutionary intermediates of the viral capsid using ancestral sequence reconstruction. In-silico-derived sequences were synthesized de novo and characterized for biological properties relevant to clinical applications. This effort led to the generation of nine functional putative ancestral AAVs and the identification of Anc80, the predicted ancestor of the widely studied AAV serotypes 1, 2, 8, and 9, as a highly potent in vivo gene therapy vector for targeting liver, muscle, and retina. PMID:26235624

  16. Stereotaxic Injection of a Viral Vector for Conditional Gene Manipulation in the Mouse Spinal Cord

    PubMed Central

    Inquimbert, Perrine; Moll, Martin; Kohno, Tatsuro; Scholz, Joachim

    2013-01-01

    Intraparenchymal injection of a viral vector enables conditional gene manipulation in distinct populations of neurons or particular regions of the central nervous system. We demonstrate a stereotaxic injection technique that allows targeted gene expression or silencing in the dorsal horn of the mouse spinal cord. The surgical procedure is brief. It requires laminectomy of a single vertebra, providing for quick recovery of the animal and unimpaired motility of the spine. Controlled injection of a small vector suspension volume at low speed and use of a microsyringe with beveled glass cannula minimize the tissue lesion. The local immune response to the vector depends on the intrinsic properties of the virus employed; in our experience, it is minor and short-lived when a recombinant adeno-associated virus is used. A reporter gene such as enhanced green fluorescent protein facilitates monitoring spatial distribution of the vector, and the efficacy and cellular specificity of the transfection. PMID:23542888

  17. Adeno-associated virus-2 and its primary cellular receptor-Cryo-EM structure of a heparin complex

    SciTech Connect

    O'Donnell, Jason; Taylor, Kenneth A.; Chapman, Michael S.

    2009-03-15

    Adeno-associated virus serotype 2 (AAV-2) is a leading candidate vector for gene therapy. Cell entry starts with attachment to a primary receptor, Heparan Sulfate Proteoglycan (HSPG) before binding to a co-receptor. Here, cryo-electron microscopy provides direct visualization of the virus-HSPG interactions. Single particle analysis was performed on AAV-2 complexed with a 17 kDa heparin fragment at 8.3 A resolution. Heparin density covers the shoulder of spikes surrounding viral 3-fold symmetry axes. Previously implicated, positively charged residues R{sub 448/585}, R{sub 451/588} and R{sub 350/487} from another subunit cluster at the center of the heparin footprint. The footprint is much more extensive than apparent through mutagenesis, including R{sub 347/484}, K{sub 395/532} and K{sub 390/527} that are more conserved, but whose roles have been controversial. It also includes much of a region proposed as a co-receptor site, because prior studies had not revealed heparin interactions. Heparin density bridges over the viral 3-fold axes, indicating multi-valent attachment to symmetry-related binding sites.

  18. Structural Studies of Adeno-Associated Virus Serotype 8 Capsid Transitions Associated with Endosomal Trafficking

    SciTech Connect

    Nam, Hyun-Joo; Gurda, Brittney L.; McKenna, Robert; Potter, Mark; Byrne, Barry; Salganik, Maxim; Muzyczka, Nicholas; Agbandje-McKenna, Mavis

    2012-09-17

    The single-stranded DNA (ssDNA) parvoviruses enter host cells through receptor-mediated endocytosis, and infection depends on processing in the early to late endosome as well as in the lysosome prior to nuclear entry for replication. However, the mechanisms of capsid endosomal processing, including the effects of low pH, are poorly understood. To gain insight into the structural transitions required for this essential step in infection, the crystal structures of empty and green fluorescent protein (GFP) gene-packaged adeno-associated virus serotype 8 (AAV8) have been determined at pH values of 6.0, 5.5, and 4.0 and then at pH 7.5 after incubation at pH 4.0, mimicking the conditions encountered during endocytic trafficking. While the capsid viral protein (VP) topologies of all the structures were similar, significant amino acid side chain conformational rearrangements were observed on (i) the interior surface of the capsid under the icosahedral 3-fold axis near ordered nucleic acid density that was lost concomitant with the conformational change as pH was reduced and (ii) the exterior capsid surface close to the icosahedral 2-fold depression. The 3-fold change is consistent with DNA release from an ordering interaction on the inside surface of the capsid at low pH values and suggests transitions that likely trigger the capsid for genome uncoating. The surface change results in disruption of VP-VP interface interactions and a decrease in buried surface area between VP monomers. This disruption points to capsid destabilization which may (i) release VP1 amino acids for its phospholipase A2 function for endosomal escape and nuclear localization signals for nuclear targeting and (ii) trigger genome uncoating.

  19. Common gene therapy viral vectors do not efficiently penetrate sputum from cystic fibrosis patients.

    PubMed

    Hida, Kaoru; Lai, Samuel K; Suk, Jung Soo; Won, Sang Y; Boyle, Michael P; Hanes, Justin

    2011-01-01

    Norwalk virus and human papilloma virus, two viruses that infect humans at mucosal surfaces, have been found capable of rapidly penetrating human mucus secretions. Viral vectors for gene therapy of Cystic Fibrosis (CF) must similarly penetrate purulent lung airway mucus (sputum) to deliver DNA to airway epithelial cells. However, surprisingly little is known about the rates at which gene delivery vehicles penetrate sputum, including viral vectors used in clinical trials for CF gene therapy. We find that sputum spontaneously expectorated by CF patients efficiently traps two viral vectors commonly used in CF gene therapy trials, adenovirus (d∼80 nm) and adeno-associated virus (AAV serotype 5; d∼20 nm), leading to average effective diffusivities that are ∼3,000-fold and 12,000-fold slower than their theoretical speeds in water, respectively. Both viral vectors are slowed by adhesion, as engineered muco-inert nanoparticles with diameters as large as 200 nm penetrate the same sputum samples at rates only ∼40-fold reduced compared to in pure water. A limited fraction of AAV exhibit sufficiently fast mobility to penetrate physiologically thick sputum layers, likely because of the lower viscous drag and smaller surface area for adhesion to sputum constituents. Nevertheless, poor penetration of CF sputum is likely a major contributor to the ineffectiveness of viral vector based gene therapy in the lungs of CF patients observed to date. PMID:21637751

  20. Rapid, scalable, and low-cost purification of recombinant adeno-associated virus produced by baculovirus expression vector system

    PubMed Central

    Buclez, Pierre-Olivier; Dias Florencio, Gabriella; Relizani, Karima; Beley, Cyriaque; Garcia, Luis; Benchaouir, Rachid

    2016-01-01

    Recombinant adeno-associated viruses (rAAV) are largely used for gene transfer in research, preclinical developments, and clinical trials. Their broad in vivo biodistribution and long-term efficacy in postmitotic tissues make them good candidates for numerous gene transfer applications. Upstream processes able to produce large amounts of rAAV were developed, particularly those using baculovirus expression vector system. In parallel, downstream processes present a large panel of purification methods, often including multiple and time consuming steps. Here, we show that simple tangential flow filtration, coupled with an optimized iodixanol-based isopycnic density gradient, is sufficient to purify several liters of crude lysate produced by baculovirus expression vector system in only one working day, leading to high titers and good purity of rAAV products. Moreover, we show that the viral vectors retain their in vitro and in vivo functionalities. Our results demonstrate that simple, rapid, and relatively low-cost methods can easily be implemented for obtaining a high-quality grade of gene therapy products based on rAAV technology. PMID:27226971

  1. Highly Divergent Integration Profile of Adeno-Associated Virus Serotype 5 Revealed by High-Throughput Sequencing

    PubMed Central

    Janovitz, Tyler; Oliveira, Thiago; Sadelain, Michel

    2014-01-01

    ABSTRACT Adeno-associated virus serotype 5 (AAV-5) is a human parvovirus that infects a high percentage of the population. It is the most divergent AAV, the DNA sequence cleaved by the viral endonuclease is distinct from all other described serotypes and, uniquely, AAV-5 does not cross-complement the replication of other serotypes. In contrast to the well-characterized integration of AAV-2, no published studies have investigated the genomic integration of AAV-5. In this study, we analyzed more than 660,000 AAV-5 integration junctions using high-throughput integrant capture sequencing of infected human cells. The integration activity of AAV-5 was 99.7% distinct from AAV-2 and favored intronic sequences. Genome-wide integration was highly correlated with viral replication protein binding and endonuclease sites, and a 39-bp consensus integration motif was revealed that included these features. Algorithmic scanning identified 126 AAV-5 hot spots, the largest of which encompassed 3.3% of all integration events. The unique aspects of AAV-5 integration may provide novel tools for biotechnology and gene therapy. IMPORTANCE Viral integration into the host genome is an important aspect of virus host cell biology. Genomic integration studies of the small single-stranded AAVs have largely focused on site preferential integration of AAV-2, which depends on the viral replication protein (Rep). We have now established the first genome wide integration profile of the highly divergent AAV-5 serotype. Using integrant capture sequencing, more than 600,000 AAV-5 integration junctions in human cells were analyzed. AAV-5 integration hot spots were 99.7% distinct from AAV-2. Integration favored intronic sequences, occurred on all chromosomes, and integration hot spot distribution was correlated with human genomic GAGC repeats and transcriptional activity. These features support expansion of AAV-5 based vectors for gene transfer considerations. PMID:24335317

  2. Restoration of hearing in the VGLUT3 knockout mouse using virally mediated gene therapy.

    PubMed

    Akil, Omar; Seal, Rebecca P; Burke, Kevin; Wang, Chuansong; Alemi, Aurash; During, Matthew; Edwards, Robert H; Lustig, Lawrence R

    2012-07-26

    Mice lacking the vesicular glutamate transporter-3 (VGLUT3) are congenitally deaf due to loss of glutamate release at the inner hair cell afferent synapse. Cochlear delivery of VGLUT3 using adeno-associated virus type 1 (AAV1) leads to transgene expression in only inner hair cells (IHCs), despite broader viral uptake. Within 2 weeks of AAV1-VGLUT3 delivery, auditory brainstem response (ABR) thresholds normalize, along with partial rescue of the startle response. Lastly, we demonstrate partial reversal of the morphologic changes seen within the afferent IHC ribbon synapse. These findings represent a successful restoration of hearing by gene replacement in mice, which is a significant advance toward gene therapy of human deafness. PMID:22841313

  3. Intracerebroventricular delivery of self-complementary adeno-associated virus serotype 9 to the adult rat brain.

    PubMed

    Donsante, A; McEachin, Z; Riley, J; Leung, C H; Kanz, L; O'Connor, D M; Boulis, N M

    2016-05-01

    Gene therapy for the central nervous system is poised to become a powerful treatment for numerous neurological disorders. Adeno-associated viral vectors based on serotype 9 (AAV9) have proven themselves to be strong candidates for delivering gene-based therapies throughout the brain and spinal cord when administered intravenously, intrathecally, intracisternally, and intracerebroventricularly (i.c.v.). Previous studies of i.c.v.-delivered self-complimentary AAV9 have been performed in neonatal mice with delivery of a single dose. However, before clinical trials can be considered, more information is required about the dose-response relationship for transduction efficiency in adult animals. In the current study, three doses of self-complementary AAV9 were administered to adult rats. High levels of transduction were observed in the hippocampus, cerebellum and cerebral cortex, and transduction increased with increasing dosage. Both neurons and astrocytes were transduced. There was no evidence of astrocytosis at the doses tested. Preliminary results from pigs receiving i.c.v. self-complementary AAV9 are also presented. The results of this study will serve to inform dosing studies in large animal models before clinical testing. PMID:26824881

  4. Human Adeno-Associated Virus Type 5 Is Only Distantly Related to Other Known Primate Helper-Dependent Parvoviruses

    PubMed Central

    Bantel-Schaal, Ursula; Delius, Hajo; Schmidt, Rainer; zur Hausen, Harald

    1999-01-01

    We have characterized 95% (4,404 nucleotides) of the genome of adeno-associated virus type 5 (AAV5), including part of the terminal repeats and the terminal resolution site. Our results show that AAV5 is different from all other described AAV serotypes at the nucleotide level and at the amino acid level. The sequence homology to AAV2, AAV3B, AAV4, and AAV6 at the nucleotide level is only between 54 and 56%. The positive strand contains two large open reading frames (ORFs). The left ORF encodes the nonstructural (Rep) proteins, and the right ORF encodes the structural (Cap) proteins. At the amino acid level the identities with the capsid proteins of other AAVs range between 51 and 59%, with a high degree of heterogeneity in regions which are considered to be on the exterior surface of the viral capsid. The overall identity for the nonstructural Rep proteins at the amino acid level is 54.4%. It is lowest at the C-terminal 128 amino acids (10%). There are only two instead of the common three putative Zn fingers in the Rep proteins. The Cap protein data suggest differences in capsid surfaces and raise the possibility of a host range distinct from those of other parvoviruses. This may have important implications for AAV vectors used in gene therapy. PMID:9882294

  5. Intracellular route and biological activity of exogenously delivered Rep proteins from the adeno-associated virus type 2

    SciTech Connect

    Awedikian, Rafi; Francois, Achille; Guilbaud, Mickael; Moullier, Philippe; Salvetti, Anna . E-mail: anna.salvetti@univ-nantes.fr

    2005-05-10

    The two large Rep proteins, Rep78 and Rep68, from the adeno-associated virus type 2 (AAV-2) are required for AAV-2 DNA replication, site-specific integration, and for the regulation of viral gene expression. The study of their activities is dependent on the ability to deliver these proteins to the cells in a time and dose-dependent manner. We evaluated the ability of a protein transduction domain (PTD) derived from the human immunodeficiency virus 1 (HIV-1) TAT protein to drive the cellular internalization of exogenously delivered PTD-fused Rep68 proteins. This analysis unexpectedly revealed that recombinant Rep68 alone, in the absence of any PTD, could be endocytosed by the cells. Rep68 as the chimeric TAT-Rep68 proteins were internalized through endocytosis in clathrin-coated vesicles and retained in late endosomes/lysosomes with no detectable nuclear localization. In the presence of adenovirus, the Rep proteins could translocate into the nucleus where they displayed a biological activity. These findings support recent reports on the mechanism of entry of TAT-fused proteins and also revealed a new property of Rep68.

  6. Vector Design Tour de Force: Integrating Combinatorial and Rational Approaches to Derive Novel Adeno-associated Virus Variants

    PubMed Central

    Marsic, Damien; Govindasamy, Lakshmanan; Currlin, Seth; Markusic, David M; Tseng, Yu-Shan; Herzog, Roland W; Agbandje-McKenna, Mavis; Zolotukhin, Sergei

    2014-01-01

    Methodologies to improve existing adeno-associated virus (AAV) vectors for gene therapy include either rational approaches or directed evolution to derive capsid variants characterized by superior transduction efficiencies in targeted tissues. Here, we integrated both approaches in one unified design strategy of “virtual family shuffling” to derive a combinatorial capsid library whereby only variable regions on the surface of the capsid are modified. Individual sublibraries were first assembled in order to preselect compatible amino acid residues within restricted surface-exposed regions to minimize the generation of dead-end variants. Subsequently, the successful families were interbred to derive a combined library of ~8 × 105 complexity. Next-generation sequencing of the packaged viral DNA revealed capsid surface areas susceptible to directed evolution, thus providing guidance for future designs. We demonstrated the utility of the library by deriving an AAV2-based vector characterized by a 20-fold higher transduction efficiency in murine liver, now equivalent to that of AAV8. PMID:25048217

  7. Vector design Tour de Force: integrating combinatorial and rational approaches to derive novel adeno-associated virus variants.

    PubMed

    Marsic, Damien; Govindasamy, Lakshmanan; Currlin, Seth; Markusic, David M; Tseng, Yu-Shan; Herzog, Roland W; Agbandje-McKenna, Mavis; Zolotukhin, Sergei

    2014-11-01

    Methodologies to improve existing adeno-associated virus (AAV) vectors for gene therapy include either rational approaches or directed evolution to derive capsid variants characterized by superior transduction efficiencies in targeted tissues. Here, we integrated both approaches in one unified design strategy of "virtual family shuffling" to derive a combinatorial capsid library whereby only variable regions on the surface of the capsid are modified. Individual sublibraries were first assembled in order to preselect compatible amino acid residues within restricted surface-exposed regions to minimize the generation of dead-end variants. Subsequently, the successful families were interbred to derive a combined library of ~8 × 10(5) complexity. Next-generation sequencing of the packaged viral DNA revealed capsid surface areas susceptible to directed evolution, thus providing guidance for future designs. We demonstrated the utility of the library by deriving an AAV2-based vector characterized by a 20-fold higher transduction efficiency in murine liver, now equivalent to that of AAV8. PMID:25048217

  8. Adeno-associated-virus-mediated transduction of the mammary gland enables sustained production of recombinant proteins in milk

    PubMed Central

    Wagner, Stefan; Thresher, Rosemary; Bland, Ross; Laible, Götz

    2015-01-01

    Biopharming for the production of recombinant pharmaceutical proteins in the mammary gland of transgenic animals is an attractive but laborious alternative compared to mammalian cell fermentation. The disadvantage of the lengthy process of genetically modifying an entire animal could be circumvented with somatic transduction of only the mammary epithelium with recombinant, replication-defective viruses. While other viral vectors offer very limited scope for this approach, vectors based on adeno-associated virus (AAV) appear to be ideal candidates because AAV is helper-dependent, does not induce a strong immune response and has no association with disease. Here, we sought to test the suitability of recombinant AAV (rAAV) for biopharming. Using reporter genes, we showed that injected rAAV efficiently transduced mouse mammary cells. When rAAV encoding human myelin basic protein (hMBP) was injected into the mammary glands of mice and rabbits, this resulted in the expression of readily detectable protein levels of up to 0.5 g/L in the milk. Furthermore we demonstrated that production of hMBP persisted over extended periods and that protein expression could be renewed in a subsequent lactation by re-injection of rAAV into a previously injected mouse gland. PMID:26463440

  9. Adeno-associated-virus-mediated transduction of the mammary gland enables sustained production of recombinant proteins in milk.

    PubMed

    Wagner, Stefan; Thresher, Rosemary; Bland, Ross; Laible, Götz

    2015-01-01

    Biopharming for the production of recombinant pharmaceutical proteins in the mammary gland of transgenic animals is an attractive but laborious alternative compared to mammalian cell fermentation. The disadvantage of the lengthy process of genetically modifying an entire animal could be circumvented with somatic transduction of only the mammary epithelium with recombinant, replication-defective viruses. While other viral vectors offer very limited scope for this approach, vectors based on adeno-associated virus (AAV) appear to be ideal candidates because AAV is helper-dependent, does not induce a strong immune response and has no association with disease. Here, we sought to test the suitability of recombinant AAV (rAAV) for biopharming. Using reporter genes, we showed that injected rAAV efficiently transduced mouse mammary cells. When rAAV encoding human myelin basic protein (hMBP) was injected into the mammary glands of mice and rabbits, this resulted in the expression of readily detectable protein levels of up to 0.5 g/L in the milk. Furthermore we demonstrated that production of hMBP persisted over extended periods and that protein expression could be renewed in a subsequent lactation by re-injection of rAAV into a previously injected mouse gland. PMID:26463440

  10. A review of therapeutic prospects of non-viral gene therapy in the retinal pigment epithelium

    PubMed Central

    Koirala, Adarsha; Conley, Shannon M.; Naash, Muna I.

    2013-01-01

    Ocular gene therapy has been extensively explored in recent years as a therapeutic avenue to target diseases of the cornea, retina and retinal pigment epithelium (RPE). Adeno-associated virus (AAV)-mediated gene therapy has shown promise in several RPE clinical trials but AAVs have limited payload capacity and potential immunogenicity. Traditionally however, non-viral alternatives have been plagued by low transfection efficiency, short-term expression and low expression levels. Recently, these drawbacks have begun to be overcome by the use of specialty carriers such as polylysine, liposomes, or polyethyleneimines, and by inclusion of suitable DNA elements to enhance gene expression and longevity. Recent advancements in the field have yielded non-viral vectors that have favorable safety profiles, lack immunogenicity, exhibit long-term elevated gene expression, and show efficient transfection in the retina and RPE, making them poised to transition to clinical applications. Here we discuss the advancements in nanotechnology and vector engineering that have improved the prospects for clinical application of non-viral gene therapy in the RPE. PMID:23796578

  11. Adeno-associated virus type 2 enhances goose parvovirus replication in embryonated goose eggs

    SciTech Connect

    Malkinson, Mertyn . E-mail: malkins@agri.huji.ac.il; Winocour, Ernest . E-mail: ernest.winocour@weizmann.ac.il

    2005-06-05

    The autonomous goose parvovirus (GPV) and the human helper-dependent adeno-associated virus type 2 (AAV2) share a high degree of homology. To determine if this evolutionary relationship has a biological impact, we studied viral replication in human 293 cells and in embryonated goose eggs coinfected with both viruses. Similar experiments were performed with the minute virus of mice (MVM), an autonomous murine parvovirus with less homology to AAV2. In human 293 cells, both GPV and MVM augmented AAV2 replication. In contrast, AAV2 markedly enhanced GPV replication in embryonated goose eggs under conditions where a similar effect was not observed with MVM. AAV2 did not replicate in embryonated goose eggs and AAV2 inactivated by UV-irradiation also enhanced GPV replication. To our knowledge, this is the first report that a human helper-dependent member of the Parvoviridae can provide helper activity for an autonomous parvovirus in a natural host.

  12. High-accuracy biodistribution analysis of adeno-associated virus variants by double barcode sequencing

    PubMed Central

    Marsic, Damien; Méndez-Gómez, Héctor R; Zolotukhin, Sergei

    2015-01-01

    Biodistribution analysis is a key step in the evaluation of adeno-associated virus (AAV) capsid variants, whether natural isolates or produced by rational design or directed evolution. Indeed, when screening candidate vectors, accurate knowledge about which tissues are infected and how efficiently is essential. We describe the design, validation, and application of a new vector, pTR-UF50-BC, encoding a bioluminescent protein, a fluorescent protein and a DNA barcode, which can be used to visualize localization of transduction at the organism, organ, tissue, or cellular levels. In addition, by linking capsid variants to different barcoded versions of the vector and amplifying the barcode region from various tissue samples using barcoded primers, biodistribution of viral genomes can be analyzed with high accuracy and efficiency. PMID:26793739

  13. Glycan binding avidity determines the systemic fate of adeno-associated virus type 9.

    PubMed

    Shen, Shen; Bryant, Kelli D; Sun, Junjiang; Brown, Sarah M; Troupes, Andrew; Pulicherla, Nagesh; Asokan, Aravind

    2012-10-01

    Glycans are key determinants of host range and transmissibility in several pathogens. In the case of adeno-associated viruses (AAV), different carbohydrates serve as cellular receptors in vitro; however, their contributions in vivo are less clear. A particularly interesting example is adeno-associated virus serotype 9 (AAV9), which displays systemic tropism in mice despite low endogenous levels of its primary receptor (galactose) in murine tissues. To understand this further, we studied the effect of modulating glycan binding avidity on the systemic fate of AAV9 in mice. Intravenous administration of recombinant sialidase increased tissue levels of terminally galactosylated glycans in several murine tissues. These conditions altered the systemic tropism of AAV9 into a hepatotropic phenotype, characterized by markedly increased sequestration within the liver sinusoidal endothelium and Kupffer cells. In contrast, an AAV9 mutant with decreased glycan binding avidity displayed a liver-detargeted phenotype. Altering glycan binding avidity also profoundly affected AAV9 persistence in blood circulation. Our results support the notion that high glycan receptor binding avidity appears to impart increased liver tropism, while decreased avidity favors systemic spread of AAV vectors. These findings may not only help predict species-specific differences in tropism for AAV9 on the basis of tissue glycosylation profiles, but also provide a general approach to tailor AAV vectors for systemic or hepatic gene transfer by reengineering capsid-glycan interactions. PMID:22787229

  14. Recombinant Adeno-Associated Virus Utilizes Cell-Specific Infectious Entry Mechanisms

    PubMed Central

    Weinberg, Marc S.; Nicolson, Sarah; Bhatt, Aadra P.; McLendon, Michael; Li, Chengwen

    2014-01-01

    ABSTRACT Understanding the entry and trafficking mechanism(s) of recombinant adeno-associated virus (rAAV) into host cells can lead to evolution in capsid and vector design and delivery methods, resulting in enhanced transduction and therapeutic gene expression. Variability of findings regarding the early entry pathway of rAAV supports the possibility that rAAV, like other viruses, can utilize more than one infectious entry pathway. We tested whether inhibition of macropinocytosis impacted rAAV transduction of HeLa cells compared to hepatocellular carcinoma cell lines. We found that macropinocytosis inhibitor cytochalasin D blocked rAAV transduction of HeLa cells (>2-fold) but enhanced (10-fold) transduction in HepG2 and Huh7 lines. Similar results were obtained with another macropinocytosis inhibitor, 5-(N-ethyl-N-isopropyl) amiloride (EIPA). The augmented transduction was due to neither viral binding nor promoter activity, affected multiple rAAV serotypes (rAAV2, rAAV2-R585E, and rAAV8), and influenced single-stranded and self-complementary virions to comparable extents. Follow-up studies using CDC42 inhibitor ML141 and p21-activated kinase 1 (PAK1) siRNA knockdown also resulted in enhanced HepG2 transduction. Microscopy revealed that macropinocytosis inhibition correlated with expedited nuclear entry of the rAAV virions into HepG2 cells. Enhancement of hepatocellular rAAV transduction extended to the mouse liver in vivo (4-fold enhancement) but inversely blocked heart tissue transduction (13-fold). This evidence of host cell-specific rAAV entry pathways confers a potent means for controlling and enhancing vector delivery and could help unify the divergent accounts of rAAV cellular entry mechanisms. IMPORTANCE There is a recognized need for improved rAAV vector targeting strategies that result in delivery of fewer total particles, averting untoward toxicity and/or an immune response against the vector. A critical step in rAAV transduction is entry and early

  15. Synthetic scaffold coating with adeno-associated virus encoding BMP2 to promote endogenous bone repair.

    PubMed

    Dupont, Kenneth M; Boerckel, Joel D; Stevens, Hazel Y; Diab, Tamim; Kolambkar, Yash M; Takahata, Masahiko; Schwarz, Edward M; Guldberg, Robert E

    2012-03-01

    Biomaterial scaffolds functionalized to stimulate endogenous repair mechanisms via the incorporation of osteogenic cues offer a potential alternative to bone grafting for the treatment of large bone defects. We first quantified the ability of a self-complementary adeno-associated viral vector encoding bone morphogenetic protein 2 (scAAV2.5-BMP2) to enhance human stem cell osteogenic differentiation in vitro. In two-dimensional culture, scAAV2.5-BMP2-transduced human mesenchymal stem cells (hMSCs) displayed significant increases in BMP2 production and alkaline phosphatase activity compared with controls. hMSCs and human amniotic-fluid-derived stem cells (hAFS cells) seeded on scAAV2.5-BMP2-coated three-dimensional porous polymer Poly(ε-caprolactone) (PCL) scaffolds also displayed significant increases in BMP2 production compared with controls during 12 weeks of culture, although only hMSC-seeded scaffolds displayed significantly increased mineral formation. PCL scaffolds coated with scAAV2.5-BMP2 were implanted into critically sized immunocompromised rat femoral defects, both with or without pre-seeding of hMSCs, representing ex vivo and in vivo gene therapy treatments, respectively. After 12 weeks, defects treated with acellular scAAV2.5-BMP2-coated scaffolds displayed increased bony bridging and had significantly higher bone ingrowth and mechanical properties compared with controls, whereas defects treated with scAAV2.5-BMP2 scaffolds pre-seeded with hMSCs failed to display significant differences relative to controls. When pooled, defect treatment with scAAV2.5-BMP2-coated scaffolds, both with or without inclusion of pre-seeded hMSCs, led to significant increases in defect mineral formation at all time points and increased mechanical properties compared with controls. This study thus presents a novel acellular bone-graft-free endogenous repair therapy for orthotopic tissue-engineered bone regeneration. PMID:21695398

  16. Role of cellular FKBP52 protein in intracellular trafficking of recombinant adeno-associated virus 2 vectors

    SciTech Connect

    Zhao Weihong; Wu Jianqing ||; Zhong Li; Chen Linyuan; Weigel-Kelley, Kirsten A. |; Qing Keyun; Larsen, Steven H.; Shou Weinian; Warrington, Kenneth H. |; Srivastava, Arun |. E-mail: asrivastava@gtc.ufl.edu

    2006-09-30

    We have reported that tyrosine-phosphorylated forms of a cellular protein, FKBP52, inhibit the second-strand DNA synthesis of adeno-associated virus 2 (AAV), leading to inefficient transgene expression from recombinant AAV vectors. To further explore the role of FKBP52 in AAV-mediated transduction, we established murine embryo fibroblasts (MEFs) cultures from FKBP52 wild-type (WT), heterozygous (HE), and knockout (KO) mice. Conventional AAV vectors failed to transduce WT MEFs efficiently, and the transduction efficiency was not significantly increased in HE or KO MEFs. AAV vectors failed to traffic efficiently to the nucleus in these cells. Treatment with hydroxyurea (HU) increased the transduction efficiency of conventional AAV vectors by {approx}25-fold in WT MEFs, but only by {approx}4-fold in KO MEFs. The use of self-complementary AAV (scAAV) vectors, which bypass the requirement of viral second-strand DNA synthesis, revealed that HU treatment increased the transduction efficiency {approx}23-fold in WT MEFs, but only {approx}4-fold in KO MEFs, indicating that the lack of HU treatment-mediated increase in KO MEFs was not due to failure of AAV to undergo viral second-strand DNA synthesis. Following HU treatment, {approx}59% of AAV genomes were present in the nuclear fraction from WT MEFs, but only {approx}28% in KO MEFs, indicating that the pathway by which HU treatment mediates nuclear transport of AAV was impaired in KO MEFs. When KO MEFs were stably transfected with an FKBP52 expression plasmid, HU treatment-mediated increase in the transduction efficiency was restored in these cells, which correlated directly with improved intracellular trafficking. Intact AAV particles were also shown to interact with FKBP52 as well as with dynein, a known cellular protein involved in AAV trafficking. These studies suggest that FKBP52, being a cellular chaperone protein, facilitates intracellular trafficking of AAV, which has implications in the optimal use of recombinant

  17. Long-Term Robust Myocardial Transduction of the Dog Heart from a Peripheral Vein by Adeno-Associated Virus Serotype-8

    PubMed Central

    Pan, Xiufang; Yue, Yongping; Zhang, Keqing; Lostal, William; Shin, Jin-Hong

    2013-01-01

    Abstract Molecular intervention using noninvasive myocardial gene transfer holds great promise for treating heart diseases. Robust cardiac transduction from peripheral vein injection has been achieved in rodents using adeno-associated virus (AAV) serotype-9 (AAV-9). However, a similar approach has failed to transduce the heart in dogs, a commonly used large animal model for heart diseases. To develop an effective noninvasive method to deliver exogenous genes to the dog heart, we employed an AAV-8 vector that expresses human placental alkaline phosphatase reporter gene under the transcriptional regulation of the Rous sarcoma virus promoter. Vectors were delivered to three neonatal dogs at the doses of 1.35×1014, 7.14×1014, and 9.06×1014 viral genome particles/kg body weight via the jugular vein. Transduction efficiency and overall safety were evaluated at 1.5, 2.5, and 12 months postinjection. AAV delivery was well tolerated and dog growth was normal. Blood chemistry and internal organ histology were unremarkable. Widespread skeletal muscle transduction was observed in all dogs without T-cell infiltration. Encouragingly, whole heart myocardial transduction was achieved in two dogs that received higher doses and cardiac expression lasted for at least 1 year. In summary, peripheral vein AAV-8 injection may represent a simple heart gene transfer method in large mammals. Further optimization of this gene delivery strategy may open the door for a readily applicable gene therapy method to treat many heart diseases. PMID:23551085

  18. Quantitative 3D Tracing of Gene-delivery Viral Vectors in Human Cells and Animal Tissues

    PubMed Central

    Xiao, Ping-Jie; Li, Chengwen; Neumann, Aaron; Samulski, R Jude

    2012-01-01

    Trafficking through a variety of cellular structures and organelles is essential for the interaction between gene-delivery vectors (i.e., adeno-associated virus (AAV) and liposomes) and host cells/tissues. Here, we present a method of computer-assisted quantitative 3D biodistribution microscopy that samples the whole population of fluorescently-labeled vectors and document their trafficking routes. Using AAV as a working model, we first experimentally defined numerical parameters for the singularity of Cy5-labeled particles by combining confocal microscopy and atomic force microscopy (AFM). We then developed a robust approach that integrates single-particle fluorescence imaging with 3D deconvolution and isosurface rendering to quantitate viral distribution and trafficking in human cells as well as animal tissues at the single-particle level. Using this quantitative method, we uncovered an as yet uncharacterized rate-limiting step during viral cell entry, while delineating nuclear accumulation of virions during the first 8 hours postinfection. Further, our studies revealed for the first time that following intramuscular injection, AAV spread progressively across muscle tissues through endomysium between myofibers instead of traversing through target cells. Such 3D resolution and quantitative dissection of vector–host interactions at the subcellular level should significantly improve our ability to resolve trafficking mechanisms of gene-delivery particles and facilitate the development of enhanced viral vectors. PMID:22108857

  19. Immobilization of FLAG-Tagged Recombinant Adeno-Associated Virus 2 onto Tissue Engineering Scaffolds for the Improvement of Transgene Delivery in Cell Transplants

    PubMed Central

    Shi, Wen-Jie; Bai, Xue-Jia; Jia, Shu-Qin; Zhang, Chen-Guang; Ding, Wei

    2015-01-01

    The technology of virus-based genetic modification in tissue engineering has provided the opportunity to produce more flexible and versatile biomaterials for transplantation. Localizing the transgene expression with increased efficiency is critical for tissue engineering as well as a challenge for virus-based gene delivery. In this study, we tagged the VP2 protein of type 2 adeno-associated virus (AAV) with a 3×FLAG plasmid at the N-terminus and packaged a FLAG-tagged recombinant AAV2 chimeric mutant. The mutant AAVs were immobilized onto the tissue engineering scaffolds with crosslinked anti-FLAG antibodies by N-succinimidyl-3-(2-pyridyldithiol) propionate (SPDP). Cultured cells were seeded to scaffolds to form 3D transplants, and then tested for viral transduction both in vitro and in vivo. The results showed that our FLAG-tagged AAV2 exerted similar transduction efficiency compared with the wild type AAV2 when infected cultured cells. Following immobilization onto the scaffolds of PLGA or gelatin sponge with anti-FLAG antibodies, the viral mediated transgene expression was significantly improved and more localized. Our data demonstrated that the mutation of AAV capsid targeted for antibody-based immobilization could be a practical approach for more efficient and precise transgene delivery. It was also suggested that the immobilization of AAV might have attractive potentials in applications of tissue engineering involving the targeted gene manipulation in 3D tissue cultures. PMID:26035716

  20. Adeno-associated virus-mediated expression of β-hexosaminidase prevents neuronal loss in the Sandhoff mouse brain.

    PubMed

    Sargeant, Timothy J; Wang, Susan; Bradley, Josephine; Smith, Nicolas J C; Raha, Animesh A; McNair, Rosamund; Ziegler, Robin J; Cheng, Seng H; Cox, Timothy M; Cachón-González, Maria Begoña

    2011-11-15

    Sandhoff disease, a GM2 gangliosidosis caused by a deficiency in β-hexosaminidase, is characterized by progressive neurodegeneration. Although loss of neurons in association with lysosomal storage of glycosphingolipids occurs in patients with this disease, the molecular pathways that lead to the accompanying neurological defects are unclear. Using an authentic murine model of GM2 gangliosidosis, we examined the pattern of neuronal loss in the central nervous system and investigated the effects of gene transfer using recombinant adeno-associated viral vectors expressing β-hexosaminidase subunits (rAAV2/1-Hex). In 4-month-old Sandhoff mice with neurological deficits, cells staining positively for the apoptotic signature in the TUNEL reaction were found in the ventroposterior medial and ventroposterior lateral (VPM/VPL) nuclei of the thalamus. There was progressive loss of neuronal density in this region with age. Comparable loss of neuronal density was identified in the lateral vestibular nucleus of the brainstem and a small but statistically significant loss was present in the ventral spinal cord. Loss of neurons was not detected in other regions that were analysed. Administration of rAAV2/1-Hex into the brain of Sandhoff mice prevented the decline in neuronal density in the VPM/VPL. Preservation of neurons in the VPM/VPL was variable at the humane endpoint in treated animals, but correlated directly with increased lifespan. Loss of neurons was localized to only a few regions in the Sandhoff brain and was prevented by rAAV-mediated transfer of β-hexosaminidase gene function at considerable distances from the site of vector administration. PMID:21852247

  1. Cloning of adeno-associated virus type 4 (AAV4) and generation of recombinant AAV4 particles.

    PubMed Central

    Chiorini, J A; Yang, L; Liu, Y; Safer, B; Kotin, R M

    1997-01-01

    We have cloned and characterized the full-length genome of adeno-associated virus type 4 (AAV4). The genome of AAV4 is 4,767 nucleotides in length and contains an expanded p5 promoter region compared to AAV2 and AAV3. Within the inverted terminal repeat (ITR), several base changes were identified with respect to AAV2. However, these changes did not affect the ability of this region to fold into a hairpin structure. Within the ITR, the terminal resolution site and Rep binding sites were conserved; however, the Rep binding site was expanded from three GAGC repeats to four. The Rep gene product of AAV4 shows greater than 90% homology to the Rep products of serotypes 2 and 3, with none of the changes occurring in regions which had previously been shown to affect the known functions of Rep68 or Rep78. Most of the differences in the capsid proteins lie in regions which are thought to be on the exterior surface of the viral capsid. It is these unique regions which are most likely to be responsible for the lack of cross-reacting antibodies and the altered tissue tropism compared to AAV2. The results of our studies, performed with a recombinant version of AAV4 carrying a lacZ reporter gene, suggest that AAV4 can transduce human, monkey, and rat cells. Furthermore, comparison of transduction efficiencies in a number of cell lines, competition cotransduction experiments, and the effect of trypsin on transduction efficiency all suggest that the cellular receptor for AAV4 is distinct from that of AAV2. PMID:9261407

  2. Transduction of rat pancreatic islets with pseudotyped adeno-associated virus vectors

    PubMed Central

    Craig, Anthony T; Gavrilova, Oksana; Dwyer, Nancy K; Jou, William; Pack, Stephanie; Liu, Eric; Pechhold, Klaus; Schmidt, Michael; McAlister, Victor J; Chiorini, John A; Blanchette-Mackie, E Joan; Harlan, David M; Owens, Roland A

    2009-01-01

    Background Pancreatic islet transplantation is a promising treatment for type I diabetes mellitus, but current immunosuppressive strategies do not consistently provide long-term survival of transplanted islets. We are therefore investigating the use of adeno-associated viruses (AAVs) as gene therapy vectors to transduce rat islets with immunosuppressive genes prior to transplantation into diabetic mice. Results We compared the transduction efficiency of AAV2 vectors with an AAV2 capsid (AAV2/2) to AAV2 vectors pseudotyped with AAV5 (AAV2/5), AAV8 (AAV2/8) or bovine adeno-associated virus (BAAV) capsids, or an AAV2 capsid with an insertion of the low density lipoprotein receptor ligand from apolipoprotein E (AAV2apoE), on cultured islets, in the presence of helper adenovirus infection to speed expression of a GFP transgene. Confocal microscopy and flow cytometry were used. The AAV2/5 vector was superior to AAV2/2 and AAV2/8 in rat islets. Flow cytometry indicated AAV2/5-mediated gene expression in approximately 9% of rat islet cells and almost 12% of insulin-positive cells. The AAV2/8 vector had a higher dependence on the helper virus multiplicity of infection than the AAV 2/5 vector. In addition, the BAAV and AAV2apoE vectors were superior to AAV2/2 for transducing rat islets. Rat islets (300 per mouse) transduced with an AAV2/5 vector harboring the immunosuppressive transgene, tgfβ1, retain the ability to correct hyperglycemia when transplanted into immune-deficient diabetic mice. Conclusion AAV2/5 vectors may therefore be useful for pre-treating donor islets prior to transplantation. PMID:19450275

  3. Adeno-associated virus expresses transgenes in hair follicles and epidermis.

    PubMed

    Hengge, U R; Mirmohammadsadegh, A

    2000-09-01

    Adeno-associated virus (AAV) vectors are nonpathogenic, integrating DNA vectors capable of transducing dividing and nondividing cells with the potential of long-term expression. Evaluating this interesting vector system in the skin for the first time, we found that an AAV vector containing the lacZ gene (AAVlacZ) led to the expression of beta-galactosidase for more than 6 weeks following in vivo injection. Interestingly, expression was present not only in dividing and postmitotic epidermal keratinocytes but also in hair follicle epithelial cells and eccrine sweat glands. However, expression upon readministration was limited. Functional studies in swine using human erythropoietin were hampered by immunogenicity. Thus, AAV seems to be the only vector to date that efficiently targets hair follicle epithelial cells. It may also be useful when longer term expression in keratinocytes than that achievable by direct injection of plasmid DNA is desired. PMID:10985948

  4. Crystallization and preliminary X-ray structural studies of adeno-associated virus serotype 6

    PubMed Central

    Xie, Qing; Ongley, Heather M.; Hare, Joan; Chapman, Michael S.

    2008-01-01

    Adeno-associated viruses are being developed as vectors for gene therapy and have been used in a number of clinical trials. Vectors to date have been based on the type species AAV-2, the structure of which was published in 2002. There is growing interest in modulating the cellular tropism and immune neutralization of AAV-2 with variants inspired by the properties of other serotypes. Towards the determination of a structure for AAV type 6, this paper reports the high-yield production, purification, crystallization and preliminary diffraction studies of infectious AAV-6 virions. The crystals diffracted to 3.2 Å resolution using synchrotron radiation. The most promising crystal form belonged to space group R3 and appeared to be suitable for initial structure determination. PMID:18997346

  5. Phase I/II Trial of Adeno-Associated Virus–Mediated Alpha-Glucosidase Gene Therapy to the Diaphragm for Chronic Respiratory Failure in Pompe Disease: Initial Safety and Ventilatory Outcomes

    PubMed Central

    Smith, Barbara K.; Collins, Shelley W.; Conlon, Thomas J.; Mah, Cathryn S.; Lawson, Lee Ann; Martin, Anatole D.; Fuller, David D.; Cleaver, Brian D.; Clément, Nathalie; Phillips, Dawn; Islam, Saleem; Dobjia, Nicole

    2013-01-01

    Abstract Pompe disease is an inherited neuromuscular disease caused by deficiency of lysosomal acid alpha-glucosidase (GAA) leading to glycogen accumulation in muscle and motoneurons. Cardiopulmonary failure in infancy leads to early mortality, and GAA enzyme replacement therapy (ERT) results in improved survival, reduction of cardiac hypertrophy, and developmental gains. However, many children have progressive ventilatory insufficiency and need additional support. Preclinical work shows that gene transfer restores phrenic neural activity and corrects ventilatory deficits. Here we present 180-day safety and ventilatory outcomes for five ventilator-dependent children in a phase I/II clinical trial of AAV-mediated GAA gene therapy (rAAV1-hGAA) following intradiaphragmatic delivery. We assessed whether rAAV1-hGAA results in acceptable safety outcomes and detectable functional changes, using general safety measures, immunological studies, and pulmonary functional testing. All subjects required chronic, full-time mechanical ventilation because of respiratory failure that was unresponsive to both ERT and preoperative muscle-conditioning exercises. After receiving a dose of either 1×1012 vg (n=3) or 5×1012 vg (n=2) of rAAV1-hGAA, the subjects' unassisted tidal volume was significantly larger (median [interquartile range] 28.8% increase [15.2–35.2], p<0.05). Further, most patients tolerated appreciably longer periods of unassisted breathing (425% increase [103–851], p=0.08). Gene transfer did not improve maximal inspiratory pressure. Expected levels of circulating antibodies and no T-cell-mediated immune responses to the vector (capsids) were observed. One subject demonstrated a slight increase in anti-GAA antibody that was not considered clinically significant. These results indicate that rAAV1-hGAA was safe and may lead to modest improvements in volitional ventilatory performance measures. Evaluation of the next five patients will determine whether earlier

  6. Ultracentrifugation-free chromatography-mediated large-scale purification of recombinant adeno-associated virus serotype 1 (rAAV1)

    PubMed Central

    Tomono, Taro; Hirai, Yukihiko; Okada, Hironori; Adachi, Kumi; Ishii, Akiko; Shimada, Takashi; Onodera, Masafumi; Tamaoka, Akira; Okada, Takashi

    2016-01-01

    Recombinant adeno-associated virus (rAAV) is an attractive tool for gene transfer and shows potential for use in human gene therapies. The current methods for the production and purification of rAAV from the transfected cell lysate are mainly based on cesium chloride and iodixanol density ultracentrifugation, although those are not scalable. Meanwhile, chromatography-based systems are more scalable. Therefore, in this study, we developed a novel method for the production and purification of rAAV serotype 1 (rAAV1) from serum-free culture supernatant based on ion-exchange and gel-filtration chromatography to obtain highly purified products with an ultracentrifugation-free technique towards Good Manufacturing Practice (GMP) production. The purified rAAV1 displayed three clear and sharp bands (VP1, VP2, and VP3) following sodium dodecyl sulfate–polyacrylamide gel electrophoresis, and more than 90% of rAAV1 particles contained fully packaged viral genomes according to negative-stain electron micrographic analysis. Consequently, the resultant genomic titer of the purified rAAV1 was 3.63 × 1013 v.g./ml (the total titer was 4.17 × 1013 v.g.) from the 4 × 109 HEK293 cells. This novel chromatography-based method will facilitate scale-up of manufacturing for clinical applications in gene therapy. PMID:26913289

  7. Ultracentrifugation-free chromatography-mediated large-scale purification of recombinant adeno-associated virus serotype 1 (rAAV1).

    PubMed

    Tomono, Taro; Hirai, Yukihiko; Okada, Hironori; Adachi, Kumi; Ishii, Akiko; Shimada, Takashi; Onodera, Masafumi; Tamaoka, Akira; Okada, Takashi

    2016-01-01

    Recombinant adeno-associated virus (rAAV) is an attractive tool for gene transfer and shows potential for use in human gene therapies. The current methods for the production and purification of rAAV from the transfected cell lysate are mainly based on cesium chloride and iodixanol density ultracentrifugation, although those are not scalable. Meanwhile, chromatography-based systems are more scalable. Therefore, in this study, we developed a novel method for the production and purification of rAAV serotype 1 (rAAV1) from serum-free culture supernatant based on ion-exchange and gel-filtration chromatography to obtain highly purified products with an ultracentrifugation-free technique towards Good Manufacturing Practice (GMP) production. The purified rAAV1 displayed three clear and sharp bands (VP1, VP2, and VP3) following sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and more than 90% of rAAV1 particles contained fully packaged viral genomes according to negative-stain electron micrographic analysis. Consequently, the resultant genomic titer of the purified rAAV1 was 3.63 × 10(13) v.g./ml (the total titer was 4.17 × 10(13) v.g.) from the 4 × 10(9) HEK293 cells. This novel chromatography-based method will facilitate scale-up of manufacturing for clinical applications in gene therapy. PMID:26913289

  8. Viral Expression Cassette Elements to Enhance Transgene Target Specificity and Expression in Gene Therapy

    PubMed Central

    Powell, Sara Kathleen; Rivera-Soto, Ricardo; Gray, Steven James

    2015-01-01

    Over the last five years, the number of clinical trials involving AAV (adeno-associated virus) and lentiviral vectors continue to increase by about 150 trials each year. For continued success, AAV and lentiviral expression cassettes need to be designed to meet each disease's specific needs. This review discusses how viral vector expression cassettes can be engineered with elements to enhance target specificity and increase transgene expression. The key differences relating to target specificity between ubiquitous and tissue-specific promoters are discussed, as well as how endogenous miRNAs and their target sequences have been used to restrict transgene expression. Specifically, relevant studies indicating how cis-acting elements such as introns, WPRE, polyadenylation signals, and the CMV enhancer are highlighted to show their utility for enhancing transgene expression in gene therapy applications. All discussion bears in mind that expression cassettes have space constraints. In conclusion, this review can serve as a menu of vector genome design elements and their cost in terms of space to thoughtfully engineer viral vectors for gene therapy. PMID:25636961

  9. Postentry Processing of Recombinant Adeno-Associated Virus Type 1 and Transduction of the Ferret Lung Are Altered by a Factor in Airway Secretions

    PubMed Central

    Yan, Ziying; Sun, Xingshen; Evans, Idil A.; Tyler, Scott R.; Song, Yi; Liu, Xiaoming; Sui, Hongshu

    2013-01-01

    Abstract We recently created a cystic fibrosis ferret model that acquires neonatal lung infection. To develop lung gene therapies for this model, we evaluated recombinant adeno-associated virus (rAAV)-mediated gene transfer to the neonatal ferret lung. Unlike in vitro ferret airway epithelial (FAE) cells, in vivo infection of the ferret lung with rAAV1 required proteasome inhibitors to achieve efficient airway transduction. We hypothesized that differences in transduction between these two systems were because of an in vivo secreted factor that alter the transduction biology of rAAV1. Indeed, treatment of rAAV1 with ferret airway secretory fluid (ASF) strongly inhibited rAAV1, but not rAAV2, transduction of primary FAE and HeLa cells. Properties of the ASF inhibitory factor included a strong affinity for the AAV1 capsid, heat-stability, negative charge, and sensitivity to endoproteinase Glu-C. ASF-treated rAAV1 dramatically inhibited apical transduction of FAE ALI cultures (512-fold), while only reducing viral entry by 55-fold, suggesting that postentry processing of virus was influenced by the inhibitor factor. Proteasome inhibitors rescued transduction in the presence of ASF (∼1600-fold) without effecting virus internalization, while proteasome inhibitors only enhanced transduction 45-fold in the absence of ASF. These findings demonstrate that a factor in lung secretions can influence intracellular processing of rAAV1 in a proteasome-dependent fashion. PMID:23948055

  10. Mutational analysis of the adeno-associated virus type 2 Rep68 protein helicase motifs.

    PubMed

    Walker, S L; Wonderling, R S; Owens, R A

    1997-09-01

    The adeno-associated virus type 2 (AAV) Rep78 and Rep68 proteins are required for viral replication. These proteins are encoded by unspliced and spliced transcripts, respectively, from the p5 promoter of AAV and therefore have overlapping amino acid sequences. The Rep78 and Rep68 proteins share a variety of activities including endonuclease, helicase, and ATPase activities and the ability to bind AAV hairpin DNA. The part of the amino acid sequence which is identical in Rep78 and Rep68 contains consensus helicase motifs that are conserved among the parvovirus replication proteins. In the present study, we mutated highly conserved amino acids within these helicase motifs. The mutant proteins were synthesized as maltose binding protein-Rep68 fusions in Escherichia coli cells and affinity purified on amylose resin. The fusion proteins were assayed in vitro, and their activities were directly compared to those of the fusion protein MBP-Rep68 delta, which contains most of the amino acid sequences common to Rep78 and Rep68 and was demonstrated previously to have all of the in vitro activities of wild-type Rep78 and Rep68. Our analysis showed that almost all mutations in the putative helicase motifs severely reduced or abolished helicase activity in vitro. Most mutants also had ATPase activity less than one-eighth of the wild-type levels and lacked endonuclease activity. PMID:9261429

  11. Adeno-Associated Virus 2-Mediated Hepatocellular Carcinoma is Very Rare in Korean Patients

    PubMed Central

    Park, Kyoung-Jin; Lee, Jongan; Park, June-Hee; Joh, Jae-Won; Kwon, Choon Hyuck David

    2016-01-01

    Background The incidence and etiology of hepatocellular carcinoma (HCC) vary widely according to race and geographic regions. The insertional mutagenesis of adeno-associated virus 2 (AAV2) has recently been considered a new viral etiology of HCC. The aim of this study was to investigate the frequency and clinical characteristics of AAV2 in Korean patients with HCC. Methods A total of 289 unrelated Korean patients with HCC, including 159 Hepatitis-B-related cases, 16 Hepatitis-C-related cases, and 114 viral serology-negative cases, who underwent surgery at the Samsung Medical Center in Korea from 2009 to 2014 were enrolled in this study. The presence of AAV2 in fresh-frozen tumor tissues was investigated by DNA PCR and Sanger sequencing. The clinical and pathological characteristics of AAV2-associated HCC in these patients were compared with previous findings in French patients. Results The AAV2 detection rate in Korean patients (2/289) was very low compared with that in French patients (11/193). Similar to the French patients, the Korean patients with AAV2-related HCC showed no signs of liver cirrhosis. The Korean patients were younger than the French patients with the same AAV2-associated HCC; the ages at diagnosis of the two Korean patients were 47 and 39 yr, while the median age of the 11 French patients was 55 yr (range 43-90 yr). Conclusions AAV2-associated HCC was very rare in Korean patients with HCC. Despite a limited number of cases, this study is the first to report the clinical characteristics of Korean patients with AAV2-associated HCC. These findings suggest epidemiologic differences in viral hepatocarcinogenesis between Korean and European patients. PMID:27374713

  12. Adeno-associated virus-mediated delivery of antiangiogenic factors as an antitumor strategy.

    PubMed

    Nguyen, J T; Wu, P; Clouse, M E; Hlatky, L; Terwilliger, E F

    1998-12-15

    Antiangiogenic tumor therapies have recently attracted intense interest for their broad-spectrum action, low toxicity, and, in the case of direct endothelial targeting, an absence of drug resistance. To promote tumor regression and to maintain dormancy, antiangiogenic agents need to be chronically administered. Gene therapy offers a potential way to achieve sustained therapeutic release of potent antiangiogenic substances. As a step toward this goal, we have generated recombinant adeno-associated virus (rAAV) vectors that carry genes coding for angiostatin, endostatin, and an antisense mRNA species against vascular endothelial growth factor (VEGF). These rAAVs efficiently transduced three human tumor cell lines tested. Transduction with an rAAV-encoding antisense VEGF mRNA inhibited the production of endogenous tumor cell VEGF. Conditioned media from cells transduced with this rAAV or with rAAV-expressing endostatin or angiostatin inhibited capillary endothelial cell proliferation in vitro. Antiangiogenic rAAVs may offer a novel gene therapy approach to undermining tumor neovascularization and cancer progression. PMID:9865720

  13. Neutralizing antibodies against adeno-associated virus examined prospectively in pediatric patients with hemophilia.

    PubMed

    Li, C; Narkbunnam, N; Samulski, R J; Asokan, A; Hu, G; Jacobson, L J; Manco-Johnson, M J; Monahan, P E

    2012-03-01

    Recombinant adeno-associated virus (rAAV) is a promising gene delivery vector and has recently been used in patients with hemophilia. One limitation of AAV application is that most humans have experienced wild-type AAV serotype 2 exposure, which frequently generates neutralizing antibodies (NAbs) that may inhibit rAAV2 vector transduction. Employing alternative serotypes of rAAV vectors may circumvent this problem. We investigated the development of NAbs in early childhood by examining sera gathered prospectively from 62 children with hemophilia A, participating in a multi-institutional hemophilia clinical trial (the Joint Outcome Study). Clinical applications in hemophilia therapy have been suggested for serotypes AAV2, AAV5 and AAV8, therefore NAbs against these serotypes were serially assayed over a median follow-up of 4 years. NAbs prevalence increased during early childhood for all serotypes. NAbs against AAV2 (43.5%) were observed more frequently and at higher titers compared with both AAV5 (25.8%) and AAV8 (22.6%). NAbs against AAV5 or AAV8 were rarely observed in the absence of co-prevalent and higher titer AAV2 NAbs, suggesting that NAbs to AAV5 and AAV8 were detected following AAV2 exposure due to partial cross-reactivity of AAV2-directed NAbs. The results may guide rational design of clinical trials using alternative AAV serotypes and suggest that younger patients who are given AAV gene therapy will benefit from the lower prevalence of NAbs. PMID:21697954

  14. Efficacy of an adeno-associated virus 8-pseudotyped vector in glycogen storage disease type II.

    PubMed

    Sun, Baodong; Zhang, Haoyue; Franco, Luis M; Young, Sarah P; Schneider, Ayn; Bird, Andrew; Amalfitano, Andrea; Chen, Y-T; Koeberl, Dwight D

    2005-01-01

    Glycogen storage disease type II (GSD-II; Pompe disease) causes death in infancy from cardiorespiratory failure. The underlying deficiency of acid alpha-glucosidase (GAA; acid maltase) can be corrected by liver-targeted gene therapy in GSD-II, if secretion of GAA is accompanied by receptor-mediated uptake in cardiac and skeletal muscle. An adeno-associated virus (AAV) vector encoding human (h) GAA was pseudotyped as AAV8 (AAV2/8) and injected intravenously into immunodeficient GSD-II mice. High levels of hGAA were maintained in plasma for 24 weeks following AAV2/8 vector administration. A marked increase in vector copy number in the liver was demonstrated for the AAV2/8 vector compared to the analogous AAV2/2 vector. GAA deficiency in the heart and skeletal muscle was corrected with the AAV2/8 vector in male GSD-II mice, consistent with receptor-mediated uptake of hGAA. Male GSD-II mice demonstrated complete correction of glycogen storage in heart and diaphragm with the AAV2/8 vector, while female GSD-II mice had correction only in the heart. A biomarker for GSD-II was reduced in both sexes following AAV2/8 vector administration. Therefore, GAA production with an AAV2/8 vector in a depot organ, the liver, generated evidence for efficacious gene therapy in a mouse model for GSD-II. PMID:15585406

  15. Recombinant Adeno-Associated Virus Serotype 6 Efficiently Transduces Primary Human Melanocytes

    PubMed Central

    Verdon, Daniel; Chen, Jennifer; Taylor, John A.; Dunbar, P. Rod

    2013-01-01

    The study of melanocyte biology is important to understand their role in health and disease. However, current methods of gene transfer into melanocytes are limited by safety or efficacy. Recombinant adeno-associated virus (rAAV) has been extensively investigated as a gene therapy vector, is safe and is associated with persistent transgene expression without genome integration. There are twelve serotypes and many capsid variants of rAAV. However, a comparative study to determine which rAAV is most efficient at transducing primary human melanocytes has not been conducted. We therefore sought to determine the optimum rAAV variant for use in the in vitro transduction of primary human melanocytes, which could also be informative to future in vivo studies. We have screened eight variants of rAAV for their ability to transduce primary human melanocytes and identified rAAV6 as the optimal serotype, transducing 7–78% of cells. No increase in transduction was seen with rAAV6 tyrosine capsid mutants. The number of cells expressing the transgene peaked at 6–12 days post-infection, and transduced cells were still detectable at day 28. Therefore rAAV6 should be considered as a non-integrating vector for the transduction of primary human melanocytes. PMID:23646140

  16. Adeno-associated virus Rep-mediated targeting of integrase-defective retroviral vector DNA circles into human chromosome 19

    SciTech Connect

    Huang, Shuohao; Kawabe, Yoshinori; Ito, Akira; Kamihira, Masamichi

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer Adeno-associated virus (AAV) is capable of targeted integration in human cells. Black-Right-Pointing-Pointer Integrase-defective retroviral vector (IDRV) enables a circular DNA delivery. Black-Right-Pointing-Pointer A targeted integration system of IDRV DNA using the AAV integration mechanism. Black-Right-Pointing-Pointer Targeted IDRV integration ameliorates the safety concerns for retroviral vectors. -- Abstract: Retroviral vectors have been employed in clinical trials for gene therapy owing to their relative large packaging capacity, alterable cell tropism, and chromosomal integration for stable transgene expression. However, uncontrollable integrations of transgenes are likely to cause safety issues, such as insertional mutagenesis. A targeted transgene integration system for retroviral vectors, therefore, is a straightforward way to address the insertional mutagenesis issue. Adeno-associated virus (AAV) is the only known virus capable of targeted integration in human cells. In the presence of AAV Rep proteins, plasmids possessing the p5 integration efficiency element (p5IEE) can be integrated into the AAV integration site (AAVS1) in the human genome. In this report, we describe a system that can target the circular DNA derived from non-integrating retroviral vectors to the AAVS1 site by utilizing the Rep/p5IEE integration mechanism. Our results showed that after G418 selection 30% of collected clones had retroviral DNA targeted at the AAVS1 site.

  17. Structure of adeno-associated virus-2 in complex with neutralizing monoclonal antibody A20

    SciTech Connect

    McCraw, Dustin M.; O'Donnell, Jason K.; Taylor, Kenneth A.; Stagg, Scott M.; Chapman, Michael S.

    2012-09-15

    The use of adeno-associated virus (AAV) as a gene therapy vector is limited by the host neutralizing immune response. The cryo-electron microscopy (EM) structure at 8.5 A resolution is determined for a complex of AAV-2 with the Fab' fragment of monoclonal antibody (MAb) A20, the most extensively characterized AAV MAb. The binding footprint is determined through fitting the cryo-EM reconstruction with a homology model following sequencing of the variable domain, and provides a structural basis for integrating diverse prior epitope mappings. The footprint extends from the previously implicated plateau to the side of the spike, and into the conserved canyon, covering a larger area than anticipated. Comparison with structures of binding and non-binding serotypes indicates that recognition depends on a combination of subtle serotype-specific features. Separation of the neutralizing epitope from the heparan sulfate cell attachment site encourages attempts to develop immune-resistant vectors that can still bind to target cells.

  18. Human Treg responses allow sustained recombinant adeno-associated virus–mediated transgene expression

    PubMed Central

    Mueller, Christian; Chulay, Jeffrey D.; Trapnell, Bruce C.; Humphries, Margaret; Carey, Brenna; Sandhaus, Robert A.; McElvaney, Noel G.; Messina, Louis; Tang, Qiushi; Rouhani, Farshid N.; Campbell-Thompson, Martha; Fu, Ann Dongtao; Yachnis, Anthony; Knop, David R.; Ye, Guo-jie; Brantly, Mark; Calcedo, Roberto; Somanathan, Suryanarayan; Richman, Lee P.; Vonderheide, Robert H.; Hulme, Maigan A.; Brusko, Todd M.; Wilson, James M.; Flotte, Terence R.

    2013-01-01

    Recombinant adeno-associated virus (rAAV) vectors have shown promise for the treatment of several diseases; however, immune-mediated elimination of transduced cells has been suggested to limit and account for a loss of efficacy. To determine whether rAAV vector expression can persist long term, we administered rAAV vectors expressing normal, M-type α-1 antitrypsin (M-AAT) to AAT-deficient subjects at various doses by multiple i.m. injections. M-specific AAT expression was observed in all subjects in a dose-dependent manner and was sustained for more than 1 year in the absence of immune suppression. Muscle biopsies at 1 year had sustained AAT expression and a reduction of inflammatory cells compared with 3 month biopsies. Deep sequencing of the TCR Vβ region from muscle biopsies demonstrated a limited number of T cell clones that emerged at 3 months after vector administration and persisted for 1 year. In situ immunophenotyping revealed a substantial Treg population in muscle biopsy samples containing AAT-expressing myofibers. Approximately 10% of all T cells in muscle were natural Tregs, which were activated in response to AAV capsid. These results suggest that i.m. delivery of rAAV type 1–AAT (rAAV1-AAT) induces a T regulatory response that allows ongoing transgene expression and indicates that immunomodulatory treatments may not be necessary for rAAV-mediated gene therapy. PMID:24231351

  19. Self-Complementary Adeno-Associated Virus Vectors Improve Transduction Efficiency of Corneal Endothelial Cells

    PubMed Central

    Gruenert, Anja K.; Czugala, Marta; Mueller, Chris; Schmeer, Marco; Schleef, Martin; Kruse, Friedrich E.; Fuchsluger, Thomas A.

    2016-01-01

    Transplantation of a donor cornea to restore vision is the most frequently performed transplantation in the world. Corneal endothelial cells (CEC) are crucial for the outcome of a graft as they maintain corneal transparency and avoid graft failure due to corneal opaqueness. Given the characteristic of being a monolayer and in direct contact with culture medium during cultivation in eye banks, CEC are specifically suitable for gene therapeutic approaches prior to transplantation. Recombinant adeno-associated virus 2 (rAAV2) vectors represent a promising tool for gene therapy of CEC. However, high vector titers are needed to achieve sufficient gene expression. One of the rate-limiting steps for transgene expression is the conversion of single-stranded (ss-) DNA vector genome into double-stranded (ds-) DNA. This step can be bypassed by using self-complementary (sc-) AAV2 vectors. Aim of this study was to compare for the first time transduction efficiencies of ss- and scAAV2 vectors in CEC. For this purpose AAV2 vectors containing enhanced green fluorescent protein (GFP) as transgene were used. Both in CEC and in donor corneas, transduction with scAAV2 resulted in significantly higher transgene expression compared to ssAAV2. The difference in transduction efficiency decreased with increasing vector titer. In most cases, only half the vector titer of scAAV2 was required for equal or higher gene expression rates than those of ssAAV2. In human donor corneas, GFP expression was 64.7±11.3% (scAAV) and 38.0±8.6% (ssAAV) (p<0.001), respectively. Furthermore, transduced cells maintained their viability and showed regular morphology. Working together with regulatory authorities, a translation of AAV2 vector-mediated gene therapy to achieve a temporary protection of corneal allografts during cultivation and transplantation could therefore become more realistic. PMID:27023329

  20. Oligomeric Properties of Adeno-Associated Virus Rep68 Reflect Its Multifunctionality

    PubMed Central

    Zarate-Perez, Francisco; Mansilla-Soto, Jorge; Bardelli, Martino; Burgner, John W.; Villamil-Jarauta, Maria; Kekilli, Demet; Samso, Monserrat

    2013-01-01

    The adeno-associated virus (AAV) encodes four regulatory proteins called Rep. The large AAV Rep proteins Rep68 and Rep78 are essential factors required in almost every step of the viral life cycle. Structurally, they share two domains: a modified version of the AAA+ domain that characterizes the SF3 family of helicases and an N-terminal domain that binds DNA specifically. The combination of these two domains imparts extraordinary multifunctionality to work as initiators of DNA replication and regulators of transcription, in addition to their essential role during site-specific integration. Although most members of the SF3 family form hexameric rings in vitro, the oligomeric nature of Rep68 is unclear due to its propensity to aggregate in solution. We report here a comprehensive study to determine the oligomeric character of Rep68 using a combination of methods that includes sedimentation velocity ultracentrifugation, electron microscopy, and hydrodynamic modeling. We have determined that residue Cys151 induces Rep68 to aggregate in vitro. We show that Rep68 displays a concentration-dependent dynamic oligomeric behavior characterized by the presence of two populations: one with monomers and dimers in slow equilibrium and a second one consisting of a mixture of multiple-ring structures of seven and eight members. The presence of either ATP or ADP induces formation of larger complexes formed by the stacking of multiple rings. Taken together, our results support the idea of a Rep68 molecule that exhibits the flexible oligomeric behavior needed to perform the wide range of functions occurring during the AAV life cycle. PMID:23152528

  1. Structural Insight into the Unique Properties of Adeno-Associated Virus Serotype 9

    PubMed Central

    DiMattia, Michael A.; Nam, Hyun-Joo; Van Vliet, Kim; Mitchell, Matthew; Bennett, Antonette; Gurda, Brittney L.; McKenna, Robert; Olson, Norman H.; Sinkovits, Robert S.; Potter, Mark; Byrne, Barry J.; Aslanidi, George; Zolotukhin, Sergei; Muzyczka, Nicholas; Baker, Timothy S.

    2012-01-01

    Adeno-associated virus serotype 9 (AAV9) has enhanced capsid-associated tropism for cardiac muscle and the ability to cross the blood-brain barrier compared to other AAV serotypes. To help identify the structural features facilitating these properties, we have used cryo-electron microscopy (cryo-EM) and three-dimensional image reconstruction (cryo-reconstruction) and X-ray crystallography to determine the structure of the AAV9 capsid at 9.7- and 2.8-Å resolutions, respectively. The AAV9 capsid exhibits the surface topology conserved in all AAVs: depressions at each icosahedral two-fold symmetry axis and surrounding each five-fold axis, three separate protrusions surrounding each three-fold axis, and a channel at each five-fold axis. The AAV9 viral protein (VP) has a conserved core structure, consisting of an eight-stranded, β-barrel motif and the αA helix, which are present in all parvovirus structures. The AAV9 VP differs in nine variable surface regions (VR-I to -IX) compared to AAV4, but at only three (VR-I, VR-II, and VR-IV) compared to AAV2 and AAV8. VR-I differences modify the raised region of the capsid surface between the two-fold and five-fold depressions. The VR-IV difference produces smaller three-fold protrusions in AAV9 that are less “pointed” than AAV2 and AAV8. Significantly, residues in the AAV9 VRs have been identified as important determinants of cellular tropism and transduction and dictate its antigenic diversity from AAV2. Hence, the AAV9 VRs likely confer the unique infection phenotypes of this serotype. PMID:22496238

  2. Comparative evaluation of viral, nonviral and physical methods of gene delivery to normal and transformed lung epithelial cells.

    PubMed

    Gilbert, Jennifer L; Purcell, James; Strappe, Padraig; McCabe, Matthew; O'Brien, Timothy; O'Dea, Shirley

    2008-09-01

    Few studies have directly compared the efficiencies of gene delivery methods that target normal lung cells versus lung tumor cells. We report the first study directly comparing the efficiency and toxicity of viral [adeno-associated virus (AAV2, 5, 6) and lentivirus], nonviral (Effectene, SuperFect and Lipofectamine 2000) and physical [particle-mediated gene transfer (PMGT)] methods of gene delivery in normal mouse lung cells and in mouse adenocarcinoma cells. Lentivirus pseudotyped with the vesicular stomatitis virus glycoprotein was the most efficient gene transfer method for normal mouse airway epithelial cells [25.95 (+/-3.57) %] whereas AAV6 was most efficient for MLE-12 adenocarcinoma cells [68.2 (+/-3.2) %]. PMGT was more efficient in normal mouse airway epithelial cells than AAV5, Lipofectamine 2000 and SuperFect. AAV5 displayed the lowest transfection efficiency at less than 10% in both cell types. PMGT was the only method that resulted in significant toxicity. In summary, for all of the gene delivery methods examined here, lung tumor cells were transfected more easily than normal lung cells. Lipofectamine 2000 is potentially highly selective for lung tumor cells whereas AAV6 and lentivirus vesicular stomatitis virus glycoprotein may be useful for gene delivery strategies that require targeting of both normal and tumor cells. PMID:18690089

  3. Identification and Characterization of Nuclear and Nucleolar Localization Signals in the Adeno-Associated Virus Serotype 2 Assembly-Activating Protein

    PubMed Central

    Earley, Lauriel F.; Kawano, Yasuhiro; Adachi, Kei; Sun, Xiao-Xin; Dai, Mu-Shui

    2014-01-01

    ABSTRACT Assembly-activating protein (AAP) of adeno-associated virus serotype 2 (AAV2) is a nucleolar-localizing protein that plays a critical role in transporting the viral capsid VP3 protein to the nucleolus for assembly. Here, we identify and characterize AAV2 AAP (AAP2) nuclear (NLS) and nucleolar (NoLS) localization signals near the carboxy-terminal region of AAP2 (amino acid positions 144 to 184) (AAP2144–184). This region contains five basic-amino-acid-rich (BR) clusters, KSKRSRR (AAP2BR1), RRR (AAP2BR2), RFR (AAP2BR3), RSTSSR (AAP2BR4), and RRIK (AAP2BR5), from the amino terminus to the carboxy terminus. We created 30 AAP2BR mutants by arginine/lysine-to-alanine mutagenesis or deletion of AAP2BRs and 8 and 1 green fluorescent protein (GFP)-AAP2BR and β-galactosidase–AAP2BR fusion proteins, respectively, and analyzed their intracellular localization in HeLa cells by immunofluorescence microscopy. The results showed that AAP2144–184 has redundant multipartite NLSs and that any combinations of 4 AAP2BRs, but not 3 or less, can constitute a functional NLS-NoLS; AAP2BR1 and AAP2BR2 play the most influential role for nuclear localization, but either one of the two AAP2BRs is dispensable if all 4 of the other AAP2BRs are present, resulting in 3 different, overlapping NLS motifs; and the NoLS is shared redundantly among the five AAP2BRs and functions in a context-dependent manner. AAP2BR mutations not only resulted in aberrant intracellular localization, but also attenuated AAP2 protein expression to various degrees, and both of these abnormalities have a significant negative impact on capsid production. Thus, this study reveals the organization of the intermingling NLSs and NoLSs in AAP2 and provides insights into their functional roles in capsid assembly. IMPORTANCE Adeno-associated virus (AAV) has become a popular and successful vector for in vivo gene therapy; however, its biology has yet to be fully understood. In this regard, the recent discovery of

  4. Determination of anti-adeno-associated virus vector neutralizing antibody titer with an in vitro reporter system.

    PubMed

    Meliani, Amine; Leborgne, Christian; Triffault, Sabrina; Jeanson-Leh, Laurence; Veron, Philippe; Mingozzi, Federico

    2015-04-01

    Adeno-associated virus (AAV) vectors are a platform of choice for in vivo gene transfer applications. However, neutralizing antibodies (NAb) to AAV can be found in humans and some animal species as a result of exposure to the wild-type virus, and high-titer NAb develop following AAV vector administration. In some conditions, anti-AAV NAb can block transduction with AAV vectors even when present at low titers, thus requiring prescreening before vector administration. Here we describe an improved in vitro, cell-based assay for the determination of NAb titer in serum or plasma samples. The assay is easy to setup and sensitive and, depending on the purpose, can be validated to support clinical development of gene therapy products based on AAV vectors. PMID:25819687

  5. Stimulation of cerebral angiogenesis by gene delivery.

    PubMed

    Tang, Yaohui; Li, Yaning; Lin, Xiaojie; Miao, Peng; Wang, Yongting; Yang, Guo-Yuan

    2014-01-01

    Angiogenesis, an important process for long term neurological recovery, could be induced by ischemic brain injury. In this chapter, we describe a system to deliver adeno-associated viral (AAV) vector-mediated gene therapy for ischemic stroke. This includes the methods to construct, produce, and purify an AAV vector expressing target gene and an approach to quantify the number of microvessels and capillary density with synchrotron radiation angiography (SRA) imaging. PMID:24510875

  6. A novel polyethyleneimine-coated adeno-associated virus-like particle formulation for efficient siRNA delivery in breast cancer therapy: preparation and in vitro analysis

    PubMed Central

    Shao, Wei; Paul, Arghya; Abbasi, Sana; Chahal, Parminder S; Mena, Jimmy A; Montes, Johnny; Kamen, Amine; Prakash, Satya

    2012-01-01

    Background Systemic delivery of small interfering RNA (siRNA) is limited by its poor stability and limited cell-penetrating properties. To overcome these limitations, we designed an efficient siRNA delivery system using polyethyleneimine-coated virus-like particles derived from adeno-associated virus type 2 (PEI-AAV2-VLPs). Methods AAV2-VLPs were produced in insect cells by infection with a baculovirus vector containing three AAV2 capsid genes. Using this method, we generated well dispersed AAV2-VLPs with an average diameter of 20 nm, similar to that of the wild-type AAV2 capsid. The nanoparticles were subsequently purified by chromatography and three viral capsid proteins were confirmed by Western blot. The negatively charged AAV2-VLPs were surface-coated with PEI to develop cationic nanoparticles, and the formulation was used for efficient siRNA delivery under optimized transfection conditions. Results PEI-AAV2-VLPs were able to condense siRNA and to protect it from degradation by nucleases, as confirmed by gel electrophoresis. siRNA delivery mediated by PEI-AAV2-VLPs resulted in a high transfection rate in MCF-7 breast cancer cells with no significant cytotoxicity. A cell death assay also confirmed the efficacy and functionality of this novel siRNA formulation towards MCF-7 cancer cells, in which more than 60% of cell death was induced within 72 hours of transfection. Conclusion The present study explores the potential of virus-like particles as a new approach for gene delivery and confirms its potential for breast cancer therapy. PMID:22619514

  7. Expressing Transgenes That Exceed the Packaging Capacity of Adeno-Associated Virus Capsids.

    PubMed

    Chamberlain, Kyle; Riyad, Jalish Mahmud; Weber, Thomas

    2016-02-01

    Recombinant adeno-associated virus vectors (rAAV) are being explored as gene delivery vehicles for the treatment of various inherited and acquired disorders. rAAVs are attractive vectors for several reasons: wild-type AAVs are nonpathogenic, and rAAVs can trigger long-term transgene expression even in the absence of genome integration-at least in postmitotic tissues. Moreover, rAAVs have a low immunogenic profile, and the various AAV serotypes and variants display broad but distinct tropisms. One limitation of rAAVs is that their genome-packaging capacity is only ∼5 kb. For most applications this is not of major concern because the median human protein size is 375 amino acids. Excluding the ITRs, for a protein of typical length, this allows the incorporation of ∼3.5 kb of DNA for the promoter, polyadenylation sequence, and other regulatory elements into a single AAV vector. Nonetheless, for certain diseases the packaging limit of AAV does not allow the delivery of a full-length therapeutic protein by a single AAV vector. Hence, approaches to overcome this limitation have become an important area of research for AAV gene therapy. Among the most promising approaches to overcome the limitation imposed by the packaging capacity of AAV is the use of dual-vector approaches, whereby a transgene is split across two separate AAV vectors. Coinfection of a cell with these two rAAVs will then-through a variety of mechanisms-result in the transcription of an assembled mRNA that could not be encoded by a single AAV vector because of the DNA packaging limits of AAV. The main purpose of this review is to assess the current literature with respect to dual-AAV-vector design, to highlight the effectiveness of the different methodologies and to briefly discuss future areas of research to improve the efficiency of dual-AAV-vector transduction. PMID:26757051

  8. My Life with Adeno-Associated Virus: A Long Time Spent Studying a Short Genome

    PubMed Central

    2013-01-01

    My 45 years of studying the molecular biology of adeno-associated virus are recounted. Additional activities as a mentor, department chair, and medical school administrator are described, as are my activities in the public sphere, which involved national issues related to science policy and medical education. PMID:23781880

  9. Induction of differentiation-associated changes in established human cells by infection with adeno-associated virus type 2.

    PubMed Central

    Klein-Bauernschmitt, P; zur Hausen, H; Schlehofer, J R

    1992-01-01

    The nonpathogenic human defective parvovirus adeno-associated virus (AAV) type 2 induced differentiation-associated antigens in cells of the human leukemia cell line HL60 (CD 67), as well as in two different lines of immortalized human keratinocytes, HaCaT and HPK Ia cells (involucrin and cytokeratin 10). Simultaneously, expression of the c-myc and c-myb oncogenes and the retinoblastoma gene was down regulated whereas c-fos expression increased in infected cells. These data point to the potential of AAV to induce functions related to the differentiation pathway in different types of human cells. This phenomenon may be involved in the reported oncosuppressive properties of AAV infections. Images PMID:1318400

  10. Lipofection of Purified Adeno-Associated Virus Rep68 Protein: toward a Chromosome-Targeting Nonviral Particle

    PubMed Central

    Lamartina, Stefania; Roscilli, Giuseppe; Rinaudo, Daniela; Delmastro, Paola; Toniatti, Carlo

    1998-01-01

    Adeno-associated virus (AAV) integrates very efficiently into a specific site (AAVS1) of human chromosome 19. Two elements of the AAV genome are sufficient: the inverted terminal repeats (ITRs) and the Rep78 or Rep68 protein. The incorporation of the AAV integration machinery in nonviral delivery systems is of great interest for gene therapy. We demonstrate that purified recombinant Rep68 protein is functionally active when directly delivered into human cells by using the polycationic liposome Lipofectamine, promoting the rescue-replication of a codelivered ITR-flanked cassette in adenovirus-infected cells and its site-specific integration in noninfected cells. The sequencing of cloned virus-host DNA junctions confirmed that lipofected Rep68 protein triggers site-specific integration at the same sites in chromosome 19 already characterized in cells latently infected with AAV. PMID:9696870

  11. Enhanced Transgene Expression from Recombinant Single-Stranded D-Sequence-Substituted Adeno-Associated Virus Vectors in Human Cell Lines In Vitro and in Murine Hepatocytes In Vivo

    PubMed Central

    Wang, Yuan; Lu, Yuan; Wang, Lina; Jayandharan, Giridhara R.; Aslanidi, George V.; Li, Baozheng; Cheng, Binbin; Ma, Wenqin; Lentz, Thomas; Ling, Changquan; Xiao, Xiao; Samulski, R. Jude; Muzyczka, Nicholas

    2014-01-01

    ABSTRACT We have previously reported that the removal of a 20-nucleotide sequence, termed the D sequence, from both ends of the inverted terminal repeats (ITRs) in the adeno-associated virus serotype 2 (AAV2) genome significantly impairs rescue, replication, and encapsidation of the viral genomes (X. S. Wang, S. Ponnazhagan, and A. Srivastava, J Mol Biol 250:573–580, 1995; X. S. Wang, S. Ponnazhagan, and A. Srivastava, J Virol 70:1668–1677, 1996). Here we describe that replacement of only one D sequence in either ITR restores each of these functions, but DNA strands of only single polarity are encapsidated in mature progeny virions. Since most commonly used recombinant AAV vectors contain a single-stranded DNA (ssDNA), which is transcriptionally inactive, efficient transgene expression from AAV vectors is dependent upon viral second-strand DNA synthesis. We have also identified a transcription suppressor sequence in one of the D sequences, which shares homology with the binding site for the cellular NF-κB-repressing factor (NRF). The removal of this D sequence from, and replacement with a sequence containing putative binding sites for transcription factors in, single-stranded AAV (ssAAV) vectors significantly augments transgene expression both in human cell lines in vitro and in murine hepatocytes in vivo. The development of these genome-modified ssAAV vectors has implications not only for the basic biology of AAV but also for the optimal use of these vectors in human gene therapy. IMPORTANCE The results of the studies described here not only have provided novel insights into some of the critical steps in the life cycle of a human virus, the adeno-associated virus (AAV), that causes no known disease but have also led to the development of novel recombinant AAV vectors which are more efficient in allowing increased levels of gene expression. Thus, these studies have significant implications for the potential use of these novel AAV vectors in human gene therapy

  12. In vitro and ex vivo delivery of short hairpin RNAs for control of hepatitis C viral transcript expression.

    PubMed

    Lonze, Bonnie E; Holzer, Horatio T; Knabel, Matthew K; Locke, Jayme E; DiCamillo, Gregory A; Karhadkar, Sunil S; Montgomery, Robert A; Sun, Zhaoli; Warren, Daniel S; Cameron, Andrew M

    2012-04-01

    Recurrent hepatitis C virus (HCV) infection is the most common cause of graft loss and patient death after transplantation for HCV cirrhosis. Transplant surgeons have access to uninfected explanted livers before transplantation and an opportunity to deliver RNA interference-based protective gene therapy to uninfected grafts. Conserved HCV sequences were used to design short interfering RNAs and test their ability to knockdown HCV transcript expression in an in vitro model, both by transfection and when delivered via an adeno-associated viral vector. In a rodent model of liver transplantation, portal venous perfusion of explanted grafts with an adeno-associated viral vector before transplantation produced detectable short hairpin RNA transcript expression after transplantation. The ability to deliver anti-HCV short hairpin RNAs to uninfected livers before transplantation and subsequent exposure to HCV offers hope for the possibility of preventing the currently inevitable subsequent infection of liver grafts with HCV. PMID:22508787

  13. Mapping the Structural Determinants Responsible for Enhanced T Cell Activation to the Immunogenic Adeno-Associated Virus Capsid from Isolate Rhesus 32.33

    PubMed Central

    Mays, Lauren E.; Wang, Lili; Tenney, Rebeca; Bell, Peter; Nam, Hyun-Joo; Lin, Jianping; Gurda, Brittney; Van Vliet, Kim; Mikals, Kyle; Agbandje-McKenna, Mavis

    2013-01-01

    Avoiding activation of immunity to vector-encoded proteins is critical to the safe and effective use of adeno-associated viral (AAV) vectors for gene therapy. While commonly used serotypes, such as AAV serotypes 1, 2, 7, 8, and 9, are often associated with minimal and/or dysfunctional CD8+ T cell responses in mice, the threshold for immune activation appears to be lower in higher-order species. We have modeled this discrepancy within the mouse by identifying two capsid variants with differential immune activation profiles: AAV serotype 8 (AAV8) and a hybrid between natural rhesus isolates AAVrh32 and AAVrh33 (AAVrh32.33). Here, we aimed to characterize the structural determinants of the AAVrh32.33 capsid that augment cellular immunity to vector-encoded proteins or those of AAV8 that may induce tolerance. We hypothesized that the structural domain responsible for differential immune activation could be mapped to surface-exposed regions of the capsid, such as hypervariable regions (HVRs) I to IX of VP3. To test this, a series of hybrid AAV capsids was constructed by swapping domains between AAV8 and AAVrh32.33. By comparing their ability to generate transgene-specific T cells in vivo versus the stability of transgene expression in the muscle, we confirmed that the functional domain lies within the VP3 portion of the capsid. Our studies were able to exclude the regions of VP3 which are not sufficient for augmenting the cellular immune response, notably, HVRs I, II, and V. We have also identified HVR IV as a region of interest in conferring the efficiency and stability of muscle transduction to AAVrh32.33. PMID:23720715

  14. Non-viral gene-activated matrices

    PubMed Central

    Tierney, Erica G.; Duffy, Garry P.; Cryan, Sally-Ann; Curtin, Caroline M.; O’Brien, Fergal J.

    2013-01-01

    In the context of producing enhanced therapeutics for regenerative medicine, our laboratory develops gene-activated matrices (GAMs) using non-viral gene therapy (GT) in combination with collagen-based scaffolds engineered specifically for tissue repair. Non-viral vectors have been referred to as a minority pursuit in GT but considering the concerns associated with viral vectors and as transient gene expression is such a key consideration, further research is clearly warranted for tissue engineering (TE) applications. Mesenchymal stem cells (MSCs) are well regarded for their capability in bone regeneration but as primary cells, they are difficult to transfect. We have recently optimised the non-viral vector, polyethyleneimine (PEI), to achieve high transfection efficiencies in MSCs. Subsequently, a series of PEI-based GAMs were developed using collagen, collagen-glycosaminoglycan and collagen-nanohydroxyapatite (collagen-nHa) scaffolds whereby transgene expression was detected up to 21 d with the collagen-nHa scaffold providing the most prolonged expression. Moreover, all PEI-based GAMs contained a low plasmid DNA dose of 2 µg which is far below doses often required in previous GAMs. Having successfully developed these GAMs, the ephrinB2 gene has recently been incorporated to produce a novel therapeutic GAM for bone repair. Herein, we discuss our recent investigations in the development and application of non-viral GAMs. PMID:23538777

  15. Protection from the toxicity of diisopropylfluorophosphate by adeno-associated virus expressing acetylcholinesterase

    SciTech Connect

    Li Bin; Duysen, Ellen G.; Poluektova, Larisa Y.; Murrin, L. Charles . E-mail: cmurrin@unmc.edu; Lockridge, Oksana . E-mail: olockrid@unmc.edu

    2006-07-15

    Organophosphorus esters (OP) are highly toxic chemicals used as pesticides and nerve agents. Their acute toxicity is attributed to inhibition of acetylcholinesterase (AChE, EC 3.1.1.7) in nerve synapses. Our goal was to find a new therapeutic for protection against OP toxicity. We used a gene therapy vector, adeno-associated virus serotype 2 (AAV-2), to deliver murine AChE to AChE-/- mice that have no endogenous AChE activity. The vector encoded the most abundant form of AChE: exons 2, 3, 4, and 6. Two-day old animals, with an immature immune system, were injected. AChE delivered intravenously was expressed up to 5 months in plasma, liver, heart, and lung, at 5-15% of the level in untreated wild-type mice. A few mice formed antibodies, but antibodies did not block AChE activity. The plasma AChE was a mixture of dimers and tetramers. AChE delivered intramuscularly had 40-fold higher activity levels than in wild-type muscle. None of the AChE was collagen-tailed. No retrograde transport through the motor neurons to the central nervous system was detected. AChE delivered intrastriatally assembled into tetramers. In brain, the AAV-2 vector transduced neurons, but not astrocytes and microglia. Vector-treated AChE-/- mice lived longer than saline-treated controls. AChE-/- mice were protected from diisopropylfluorophosphate-induced respiratory failure when the vector was delivered intravenously, but not intrastriatally. Since vector-treated animals had no AChE activity in diaphragm muscle, protection from respiratory failure came from AChE in other tissues. We conclude that AChE scavenged OP and in this way protected the activity of butyrylcholinesterase (BChE, EC 3.1.1.8) in motor endplates.

  16. Electron Microscopy Analysis of a Disaccharide Analog complex Reveals Receptor Interactions of Adeno-Associated Virus

    PubMed Central

    Xie, Qing; Spilman, Michael; Meyer, Nancy L.; Lerch, Thomas F.; Stagg, Scott M.; Chapman, Michael S.

    2013-01-01

    Mechanistic studies of macromolecular complexes often feature x-ray structures of complexes with bound ligands. The attachment of Adeno-Associated Virus (AAV) to cell surface glycosaminoglycans (GAGs) is an example that has not proven amenable to crystallography, because the binding of GAG analogs disrupts lattice contacts. The interactions of AAV with GAGs are of interest in mediating the cell specificity of AAV-based gene therapy vectors. Previous electron microscopy led to differing conclusions on the exact binding site and the existence of large ligand-induced conformational changes in the virus. Conformational changes are expected during cell entry, but it has remained unclear whether the electron microscopy provided evidence of their induction by GAG-binding. Taking advantage of automated data collection, careful processing and new methods of structure refinement, the structure of AAV-DJ complexed with sucrose octasulfate is determined by electron microscopy difference map analysis to 4.8 Å resolution. At this higher resolution, individual sulfate groups are discernible, providing a stereochemical validation of map interpretation, and highlighting interactions with two surface arginines that have been implicated in genetic studies. Conformational changes induced by the SOS are modest and limited to the loop most directly interacting with the ligand. While the resolution attainable will depend on sample order and other factors, there are an increasing number of macromolecular complexes that can be studied by cryo-electron microscopy at resolutions beyond 5 Å, for which the approaches used here could be used to characterize the binding of inhibitors and other small molecule effectors when crystallography is not tractable. PMID:24036405

  17. In vivo model of adeno-associated virus vector persistence and rescue.

    PubMed Central

    Afione, S A; Conrad, C K; Kearns, W G; Chunduru, S; Adams, R; Reynolds, T C; Guggino, W B; Cutting, G R; Carter, B J; Flotte, T R

    1996-01-01

    Gene therapy vectors based on human DNA viruses could be mobilized or rescued from individuals who are subsequently infected with the corresponding wild-type (wt) helper viruses. This phenomenon has been effectively modeled in vitro with both adenovirus (Ad) and adeno-associated virus (AAV) vectors but has not previously been studied in vivo. In the current study, we have developed an in vivo model to study the interactions of a recombinant AAV vector (AAV-CFTR) with wt AAV type 2 (AAV2) and a host range mutant Ad (Ad2HR405) for which monkey cells are permissive (D.E.Brough, S.A.Rice, S.Sell, and D.F.Klessig, J. Virol. 55:206-212, 1985). AAV-CFTR was administered to the respiratory epithelium of the nose or lung of rhesus macaques. Primary cells were harvested from the infusion site at time points up to 3 months after vector administration to confirm vector DNA persistence. Vector DNA was present in episomal form and could be rescued in vitro only by addition of wt AAV2 and Ad. In in vivo rescue studies, vector was administered before or after wt-AAV2 and Ad2HR405 infection, and the shedding of AAV-CFTR was examined. Ad2HR405 and wt-AAV2 infections were established in the nose with concomitant administration. wt-AAV2 replication occurred in the lung when virus was administered directly at a high titer to the lower respiratory tract. AAV-CFTR vector rescue was also observed in the latter setting. Although these studies were performed with small numbers of animals within each group, it appears that AAV-CFTR DNA persists in the primate respiratory tract and that this model may be useful for studies of recombinant AAV vector rescue. PMID:8627804

  18. Cyclodextrins in non-viral gene delivery.

    PubMed

    Lai, Wing-Fu

    2014-01-01

    Cyclodextrins (CDs) are naturally occurring cyclic oligosaccharides. They consist of (α-1,4)-linked glucose units, and possess a basket-shaped topology with an "inner-outer" amphiphilic character. Over the years, substantial efforts have been undertaken to investigate the possible use of CDs in drug delivery and controlled drug release, yet the potential of CDs in gene delivery has received comparatively less discussion in the literature. In this article, we will first discuss the properties of CDs for gene delivery, followed by a synopsis of the use of CDs in development and modification of non-viral gene carriers. Finally, areas that are noteworthy in CD-based gene delivery will be highlighted for future research. Due to the application prospects of CDs, it is anticipated that CDs will continue to emerge as an important tool for vector development, and will play significant roles in facilitating non-viral gene delivery in the forthcoming decades. PMID:24103652

  19. A Molecular Toolbox for Rapid Generation of Viral Vectors to Up- or Down-Regulate Neuronal Gene Expression in vivo

    PubMed Central

    White, Melanie D.; Milne, Ruth V. J.; Nolan, Matthew F.

    2011-01-01

    We introduce a molecular toolbox for manipulation of neuronal gene expression in vivo. The toolbox includes promoters, ion channels, optogenetic tools, fluorescent proteins, and intronic artificial microRNAs. The components are easily assembled into adeno-associated virus (AAV) or lentivirus vectors using recombination cloning. We demonstrate assembly of toolbox components into lentivirus and AAV vectors and use these vectors for in vivo expression of inwardly rectifying potassium channels (Kir2.1, Kir3.1, and Kir3.2) and an artificial microRNA targeted against the ion channel HCN1 (HCN1 miRNA). We show that AAV assembled to express HCN1 miRNA produces efficacious and specific in vivo knockdown of HCN1 channels. Comparison of in vivo viral transduction using HCN1 miRNA with mice containing a germ line deletion of HCN1 reveals similar physiological phenotypes in cerebellar Purkinje cells. The easy assembly and re-usability of the toolbox components, together with the ability to up- or down-regulate neuronal gene expression in vivo, may be useful for applications in many areas of neuroscience. PMID:21772812

  20. Treatment of congenital neurotransmitter deficiencies by intracerebral ventricular injection of an adeno-associated virus serotype 9 vector.

    PubMed

    Lee, Ni-Chung; Chien, Yin-Hsiu; Hu, Min-Hsiu; Liu, Wen-Shin; Chen, Pin-Wen; Wang, Wei-Hua; Tzen, Kai-Yuan; Byrne, Barry J; Hwu, Wuh-Liang

    2014-03-01

    Dopamine and serotonin are produced by distinct groups of neurons in the brain, and gene therapies other than direct injection have not been attempted to correct congenital deficiencies in such neurotransmitters. In this study, we performed gene therapy to treat knock-in mice with dopamine and serotonin deficiencies caused by a mutation in the aromatic L-amino acid decarboxylase (AADC) gene (Ddc(KI) mice). Intracerebral ventricular injection of neonatal mice with an adeno-associated virus (AAV) serotype 9 (AAV9) vector expressing the human AADC gene (AAV9-hAADC) resulted in widespread AADC expression in the brain. Without treatment, 4-week-old Ddc(KI) mice exhibited whole-brain homogenate dopamine and serotonin levels of 25% and 15% of normal, respectively. After gene therapy, the levels rose to 100% and 40% of normal, respectively. The gene therapy improved the growth rate and survival of Ddc(KI) mice and normalized their hindlimb clasping and cardiovascular dysfunctions. The behavioral abnormalities of the Ddc(KI) mice were partially corrected, and the treated Ddc(KI) mice were slightly more active than normal mice. No immune reactions resulted from the treatment. Therefore, a congenital neurotransmitter deficiency can be treated safely through inducing widespread expression of the deficient gene in neonatal mice. PMID:24251946

  1. Replication of adeno-associated virus in cells irradiated with UV light at 254 nm.

    PubMed Central

    Yakobson, B; Hrynko, T A; Peak, M J; Winocour, E

    1989-01-01

    Irradiation of simian virus 40 (ori mutant)-transformed Chinese hamster embryo cells (OD4 line) with UV light induced a cellular capacity which supported a full cycle of helper-independent adeno-associated virus replication. Monochromatic UV light at 254 nm was about 1,000-fold more effective than UV light at 313 nm, indicating that cellular nucleic acid is the primary chromophore in the UV-induced process leading to permissiveness for adeno-associated virus replication. The UV irradiation and the infection could be separated for up to 12 h without substantial loss of permissiveness. During this time interval, the induction process was partly sensitive to cycloheximide, suggesting a requirement for de novo protein synthesis. Images PMID:2536816

  2. Heat-shock Treatment-mediated Increase in Transduction by Recombinant Adeno-associated Virus 2 Vectors Is Independent of the Cellular Heat-shock Protein 90*

    PubMed Central

    Zhong, Li; Qing, Keyun; Si, Yue; Chen, Linyuan; Tan, Mengqun; Srivastava, Arun

    2007-01-01

    Recombinant adeno-associated virus 2 (AAV) vectors transduction efficiency varies greatly in different cell types. We have described that a cellular protein, FKBP52, in its phosphorylated form interacts with the D-sequence in the viral inverted terminal repeat, inhibits viral second strand DNA synthesis, and limits transgene expression. Here we investigated the role of cellular heat-shock protein 90 (HSP90) in AAV transduction because FKBP52 forms a complex with HSP90, and because heat-shock treatment augments AAV transduction efficiency. Heat-shock treatment of HeLa cells resulted in tyrosine dephosphorylation of FKBP52, led to stabilization of the FKBP52-HSP90 complex, and resulted in ∼6-fold increase in AAV transduction. However, when HeLa cells were pre-treated with tyrphostin 23, a specific inhibitor of cellular epidermal growth factor receptor tyrosine kinase, which phosphorylates FKBP52 at tyrosine residues, heat-shock treatment resulted in a further 18-fold increase in AAV transduction. HSP90 was shown to be a part of the FKBP52-AAV D-sequence complex, but HSP90 by itself did not bind to the D-sequence. Geldanamycin treatment, which disrupts the HSP90-FKBP52 complex, resulted in >22-fold increase in AAV transduction in heat-shock-treated cells compared with heat shock alone. Deliberate overexpression of the human HSP90 gene resulted in a significant decrease in AAV-mediated transduction in tyrphostin 23-treated cells, whereas down-modulation of HSP90 levels led to a decrease in HSP90-FKBP52-AAV D-sequence complex formation, resulting in a significant increase in AAV transduction following pre-treatment with tyrphostin 23. These studies suggest that the observed increase in AAV transduction efficiency following heat-shock treatment is unlikely to be mediated by HSP90 alone and that increased levels of HSP90, in the absence of heat shock, facilitate binding of FKBP52 to the AAV D-sequence, thereby leading to inhibition of AAV-mediated transgene expression

  3. Novel Vector Design and Hexosaminidase Variant Enabling Self-Complementary Adeno-Associated Virus for the Treatment of Tay-Sachs Disease.

    PubMed

    Karumuthil-Melethil, Subha; Nagabhushan Kalburgi, Sahana; Thompson, Patrick; Tropak, Michael; Kaytor, Michael D; Keimel, John G; Mark, Brian L; Mahuran, Don; Walia, Jagdeep S; Gray, Steven J

    2016-07-01

    GM2 gangliosidosis is a family of three genetic neurodegenerative disorders caused by the accumulation of GM2 ganglioside (GM2) in neuronal tissue. Two of these are due to the deficiency of the heterodimeric (α-β), "A" isoenzyme of lysosomal β-hexosaminidase (HexA). Mutations in the α-subunit (encoded by HEXA) lead to Tay-Sachs disease (TSD), whereas mutations in the β-subunit (encoded by HEXB) lead to Sandhoff disease (SD). The third form results from a deficiency of the GM2 activator protein (GM2AP), a substrate-specific cofactor for HexA. In their infantile, acute forms, these diseases rapidly progress with mental and psychomotor deterioration resulting in death by approximately 4 years of age. After gene transfer that overexpresses one of the deficient subunits, the amount of HexA heterodimer formed would empirically be limited by the availability of the other endogenous Hex subunit. The present study used a new variant of the human HexA α-subunit, μ, incorporating critical sequences from the β-subunit that produce a stable homodimer (HexM) and promote functional interactions with the GM2AP- GM2 complex. We report the design of a compact adeno-associated viral (AAV) genome using a synthetic promoter-intron combination to allow self-complementary (sc) packaging of the HEXM gene. Also, a previously published capsid mutant, AAV9.47, was used to deliver the gene to brain and spinal cord while having restricted biodistribution to the liver. The novel capsid and cassette design combination was characterized in vivo in TSD mice for its ability to efficiently transduce cells in the central nervous system when delivered intravenously in both adult and neonatal mice. This study demonstrates that the modified HexM is capable of degrading long-standing GM2 storage in mice, and it further demonstrates the potential of this novel scAAV vector design to facilitate widespread distribution of the HEXM gene or potentially other similar-sized genes to the nervous system

  4. Recombinant adeno-associated virus vector: use for transgene expression and anterograde tract tracing in the CNS

    PubMed Central

    Chamberlin, Nancy L.; Du, Bin; de Lacalle, Sonsoles; Saper, Clifford B.

    2016-01-01

    We used a recombinant adeno-associated virus vector (AAV) to deliver a foreign gene, green fluorescent protein (GFP), into mature neurons in adult rat CNS in vivo. Microinjections of AAV as small as 50 nl transduced hundreds of neurons at the injection site. There was virtually no retrograde transport as fewer than one neuron per brain was found distant from the injection site that exhibited GFP immunoreactivity. The gene product, GFP, filled the entire neuronal cytoplasmic compartment; GFP immunoreactivity was robust in cell bodies, axons, and nerve terminals. There was no tissue damage at the injection sites or pathogenicity indicated by changes in astrocytic or microglial markers. There was no inflammatory response as judged by leukocytic invasion. Gene expression in transduced cells was robust and apparently permanent: there was no evidence of phenotypic reversion up to 12 weeks following infection. AAV is an excellent vector for introducing foreign genes into mature CNS neurons. Not only might it be an ideal vehicle for gene therapy, but also the GFP-containing AAV presents a new strategy for tracing long axonal pathways in the CNS, which is difficult with current tracers (PHAL, biotinylated dextrans). PMID:9630611

  5. Viral Vectors for in Vivo Gene Transfer

    NASA Astrophysics Data System (ADS)

    Thévenot, E.; Dufour, N.; Déglon, N.

    The transfer of DNA into the nucleus of a eukaryotic cell (gene transfer) is a central theme of modern biology. The transfer is said to be somatic when it refers to non-germline organs of a developed individual, and germline when it concerns gametes or the fertilised egg of an animal, with the aim of transmitting the relevant genetic modification to its descendents [1]. The efficient introduction of genetic material into a somatic or germline cell and the control of its expression over time have led to major advances in understanding how genes work in vivo, i.e., in living organisms (functional genomics), but also to the development of innovative therapeutic methods (gene therapy). The efficiency of gene transfer is conditioned by the vehicle used, called the vector. Desirable features for a vector are as follows: Easy to produce high titer stocks of the vector in a reproducible way. Absence of toxicity related to transduction (transfer of genetic material into the target cell, and its expression there) and no immune reaction of the organism against the vector and/or therapeutic protein. Stability in the expression of the relevant gene over time, and the possibility of regulation, e.g., to control expression of the therapeutic protein on the physiological level, or to end expression at the end of treatment. Transduction of quiescent cells should be as efficient as transduction of dividing cells. Vectors currently used fall into two categories: non-viral and viral vectors. In non-viral vectors, the DNA is complexed with polymers, lipids, or cationic detergents (described in Chap. 3). These vectors have a low risk of toxicity and immune reaction. However, they are less efficient in vivo than viral vectors when it comes to the number of cells transduced and long-term transgene expression. (Naked DNA transfer or electroporation is rather inefficient in the organism. This type of gene transfer will not be discussed here, and the interested reader is referred to the

  6. Producing Recombinant Adeno-Associated Virus in Foster Cells: Overcoming Production Limitations Using a Baculovirus–Insect Cell Expression Strategy

    PubMed Central

    Virag, Tamas; Cecchini, Sylvain

    2009-01-01

    Abstract Establishing pharmacological parameters, such as efficacy, routes of administration, and toxicity, for recombinant adeno-associated virus (rAAV) vectors is a prerequisite for gaining acceptance for clinical applications. In fact, even a therapeutic window, that is, the dose range between therapeutic efficacy and toxicity, has yet to be determined for rAAV in vivo. Multiphase clinical trials investigating the safety and efficacy of recombinant AAV-based therapeutics will require unprecedented vector production capacity to meet the needs of preclinical toxicology studies, and the progressive clinical protocol phases of safety/dose escalation (phase I), efficacy (phase II), and high-enrollment, multicenter evaluations (phase III). Methods of rAAV production capable of supporting such trials must be scalable, robust, and efficient. We have taken advantage of the ease of scalability of nonadherent cell culture techniques coupled with the inherent efficiency of viral infection to develop an rAAV production method based on recombinant baculovirus-mediated expression of AAV components in insect-derived suspension cells. PMID:19604040

  7. Optimization of Recombinant Adeno-Associated Virus-Mediated Expression for Large Transgenes, Using a Synthetic Promoter and Tandem Array Enhancers.

    PubMed

    Yan, Ziying; Sun, Xingshen; Feng, Zehua; Li, Guiying; Fisher, John T; Stewart, Zoe A; Engelhardt, John F

    2015-06-01

    The packaging capacity of recombinant adeno-associated viral (rAAV) vectors limits the size of the promoter that can be used to express the 4.43-kb cystic fibrosis transmembrane conductance regulator (CFTR) cDNA. To circumvent this limitation, we screened a set of 100-mer synthetic enhancer elements, composed of ten 10-bp repeats, for their ability to augment CFTR transgene expression from a short 83-bp synthetic promoter in the context of an rAAV vector designed for use in the cystic fibrosis (CF) ferret model. Our initial studies assessing transcriptional activity in monolayer (nonpolarized) cultures of human airway cell lines and primary ferret airway cells revealed that three of these synthetic enhancers (F1, F5, and F10) significantly promoted transcription of a luciferase transgene in the context of plasmid transfection. Further analysis in polarized cultures of human and ferret airway epithelia at an air-liquid interface (ALI), as well as in the ferret airway in vivo, demonstrated that the F5 enhancer produced the highest level of transgene expression in the context of an AAV vector. Furthermore, we demonstrated that increasing the size of the viral genome from 4.94 to 5.04 kb did not significantly affect particle yield of the vectors, but dramatically reduced the functionality of rAAV-CFTR vectors because of small terminal deletions that extended into the CFTR expression cassette of the 5.04-kb oversized genome. Because rAAV-CFTR vectors greater than 5 kb in size are dramatically impaired with respect to vector efficacy, we used a shortened ferret CFTR minigene with a 159-bp deletion in the R domain to construct an rAAV vector (AV2/2.F5tg83-fCFTRΔR). This vector yielded an ∼17-fold increase in expression of CFTR and significantly improved Cl(-) currents in CF ALI cultures. Our study has identified a small enhancer/promoter combination that may have broad usefulness for rAAV-mediated CF gene therapy to the airway. PMID:25763813

  8. The use of a viral 2A sequence for the simultaneous over-expression of both the vgf gene and enhanced green fluorescent protein (eGFP) in vitro and in vivo

    PubMed Central

    Lewis, Jo E.; Brameld, John M.; Hill, Phil; Barrett, Perry; Ebling, Francis J.P.; Jethwa, Preeti H.

    2015-01-01

    Introduction The viral 2A sequence has become an attractive alternative to the traditional internal ribosomal entry site (IRES) for simultaneous over-expression of two genes and in combination with recombinant adeno-associated viruses (rAAV) has been used to manipulate gene expression in vitro. New method To develop a rAAV construct in combination with the viral 2A sequence to allow long-term over-expression of the vgf gene and fluorescent marker gene for tracking of the transfected neurones in vivo. Results Transient transfection of the AAV plasmid containing the vgf gene, viral 2A sequence and eGFP into SH-SY5Y cells resulted in eGFP fluorescence comparable to a commercially available reporter construct. This increase in fluorescent cells was accompanied by an increase in VGF mRNA expression. Infusion of the rAAV vector containing the vgf gene, viral 2A sequence and eGFP resulted in eGFP fluorescence in the hypothalamus of both mice and Siberian hamsters, 32 weeks post infusion. In situ hybridisation confirmed that the location of VGF mRNA expression in the hypothalamus corresponded to the eGFP pattern of fluorescence. Comparison with old method The viral 2A sequence is much smaller than the traditional IRES and therefore allowed over-expression of the vgf gene with fluorescent tracking without compromising viral capacity. Conclusion The use of the viral 2A sequence in the AAV plasmid allowed the simultaneous expression of both genes in vitro. When used in combination with rAAV it resulted in long-term over-expression of both genes at equivalent locations in the hypothalamus of both Siberian hamsters and mice, without any adverse effects. PMID:26300182

  9. Viral Vector-Based Modeling of Neurodegenerative Disorders: Parkinson's Disease.

    PubMed

    Fischer, D Luke; Gombash, Sara E; Kemp, Christopher J; Manfredsson, Fredric P; Polinski, Nicole K; Duffy, Megan F; Sortwell, Caryl E

    2016-01-01

    Gene therapy methods are increasingly used to model Parkinson's disease (PD) in animals in an effort to test experimental therapeutics within a more relevant context to disease pathophysiology and neuropathology. We have detailed several criteria that are critical or advantageous to accurately modeling PD in a murine model or in a nonhuman primate. Using these criteria, we then evaluate approaches made to model PD using viral vectors to date, including both adeno-associated viruses and lentiviruses. Lastly, we comment on the consideration of aging as a critical factor for modeling PD. PMID:26611600

  10. Drawing a high-resolution functional map of adeno-associated virus capsid by massively parallel sequencing

    PubMed Central

    Adachi, Kei; Enoki, Tatsuji; Kawano, Yasuhiro; Veraz, Michael; Nakai, Hiroyuki

    2014-01-01

    Adeno-associated virus (AAV) capsid engineering is an emerging approach to advance gene therapy. However, a systematic analysis on how each capsid amino acid contributes to multiple functions remains challenging. Here we show proof-of-principle and successful application of a novel approach, termed AAV Barcode-Seq, that allows us to characterize phenotypes of hundreds of different AAV strains in a high-throughput manner and therefore overcomes technical difficulties in the systematic analysis. In this approach, we generate DNA barcode-tagged AAV libraries and determine a spectrum of phenotypes of each AAV strain by Illumina barcode sequencing. By applying this method to AAV capsid mutant libraries tagged with DNA barcodes, we can draw a high-resolution map of AAV capsid amino acids important for the structural integrity and functions including receptor binding, tropism, neutralization and blood clearance. Thus, Barcode-Seq provides a new tool to generate a valuable resource for virus and gene therapy research. PMID:24435020

  11. Long-Term Sex-Biased Correction of Circulating Propionic Acidemia Disease Markers by Adeno-Associated Virus Vectors

    PubMed Central

    Guenzel, Adam J.; Collard, Renata; Kraus, Jan P.; Matern, Dietrich

    2015-01-01

    Abstract Propionic academia (PA) occurs because of mutations in the PCCA or PCCB genes encoding the two subunits of propionyl-CoA carboxylase, a pivotal enzyme in the breakdown of certain amino acids and odd-chain fatty acids. There is no cure for PA, but dietary protein restriction and liver transplantation can attenuate its symptoms. We show here that a single intravenous injection of adeno-associated virus 2/8 (AAV8) or AAVrh10 expressing PCCA into PA hypomorphic mice decreased systemic propionylcarnitine and methyl citrate for up to 1.5 years. However, long-term phenotypic correction was always better in male mice. AAV-mediated PCCA expression was similar in most tissues in males and females at early time points and differed only in the liver. Over 1.5 years, luciferase and PCCA expression remained elevated in cardiac tissue for both sexes. In contrast, transgene expression in the liver and skeletal muscles of female, but not male, mice waned—suggesting that these tissues were major sinks for systemic phenotypic correction. These data indicate that single systemic intravenous therapy by AAV vectors can mediate long-term phenotype correction for PA. However, tissue-specific loss of expression in females reduces efficacy when compared with males. Whether similar sex-biased AAV effects occur in human gene therapy remains to be determined. PMID:25654275

  12. Long-term sex-biased correction of circulating propionic acidemia disease markers by adeno-associated virus vectors.

    PubMed

    Guenzel, Adam J; Collard, Renata; Kraus, Jan P; Matern, Dietrich; Barry, Michael A

    2015-03-01

    Propionic academia (PA) occurs because of mutations in the PCCA or PCCB genes encoding the two subunits of propionyl-CoA carboxylase, a pivotal enzyme in the breakdown of certain amino acids and odd-chain fatty acids. There is no cure for PA, but dietary protein restriction and liver transplantation can attenuate its symptoms. We show here that a single intravenous injection of adeno-associated virus 2/8 (AAV8) or AAVrh10 expressing PCCA into PA hypomorphic mice decreased systemic propionylcarnitine and methyl citrate for up to 1.5 years. However, long-term phenotypic correction was always better in male mice. AAV-mediated PCCA expression was similar in most tissues in males and females at early time points and differed only in the liver. Over 1.5 years, luciferase and PCCA expression remained elevated in cardiac tissue for both sexes. In contrast, transgene expression in the liver and skeletal muscles of female, but not male, mice waned—suggesting that these tissues were major sinks for systemic phenotypic correction. These data indicate that single systemic intravenous therapy by AAV vectors can mediate long-term phenotype correction for PA. However, tissue-specific loss of expression in females reduces efficacy when compared with males. Whether similar sex-biased AAV effects occur in human gene therapy remains to be determined. PMID:25654275

  13. Simple downstream process based on detergent treatment improves yield and in vivo transduction efficacy of adeno-associated virus vectors

    PubMed Central

    Dias Florencio, Gabriella; Precigout, Guillaume; Beley, Cyriaque; Buclez, Pierre-Olivier; Garcia, Luis; Benchaouir, Rachid

    2015-01-01

    Recombinant adeno-associated viruses (rAAV) are promising candidates for gene therapy approaches. The last two decades were particularly fruitful in terms of processes applied in the production and purification of this type of gene transfer vectors. This rapid technological evolution led to better yields and higher levels of vector purity. Recently, some reports showed that rAAV produced by transient tri-transfection method in adherent human embryonic kidney 293 cells can be harvested directly from supernatant, leading to easier and faster purification compared to classical virus extraction from cell pellets. Here, we compare these approaches with new vector recovery method using small quantity of detergent at the initial clarification step to treat the whole transfected cell culture. Coupled with tangential flow filtration and iodixanol-based isopycnic density gradient, this new method significantly increases rAAV yields and conserves high vector purity. Moreover, this approach leads to the reduction of the total process duration. Finally, the vectors maintain their functionality, showing unexpected higher in vitro and in vivo transduction efficacies. This new development in rAAV downstream process once more demonstrates the great capacity of these vectors to easily accommodate to large panel of methods, able to furthermore ameliorate their safety, functionality, and scalability. PMID:26207258

  14. Thymosin Beta-4 Recombinant Adeno-associated Virus Enhances Human Nucleus Pulposus Cell Proliferation and Reduces Cell Apoptosis and Senescence

    PubMed Central

    Wang, Yuan-Yi; Zhu, Qing-San; Wang, Yi-Wei; Yin, Ruo-Feng

    2015-01-01

    Background: Thymosin beta-4 (TB-4) is considered key roles in tissue development, maintenance and pathological processes. The study aimed to prove TB-4 positive biological function on nucleus pulposus (NP) cell apoptosis and slowing the process of cell aging while increasing the cell proliferation. Methods: TB-4 recombinant adeno-associated virus (AAV) was constructed and induced to human NP cells. Cell of same group were cultured without gene modification as controlled group. Proliferation capacity and cell apoptosis were observed during 6 passages of the cells. Morphology and expression of the TB-4 gene were documented as parameter of cell activity during cell passage. Results: NP cells with TB-4 transfection has normal TB-4 expression and exocytosis. NP cells with TB-4 transfection performed significantly higher cell activity than that at the control group in each generation. TB-4 recombinant AAV-transfected human NP cells also show slower cell aging, lower cell apoptosis and higher cell proliferation than control group. Conclusions: TB-4 can prevent NP cell apoptosis, slow NP cell aging and promote NP cell proliferation. AAV transfection technique was able to highly and stably express TB-4 in human NP cells, which may provide a new pathway for innovation in the treatment of intervertebral disc degenerative diseases. PMID:26021512

  15. Recombinant Adeno-Associated Virus Vector Genomes Take the Form of Long-Lived, Transcriptionally Competent Episomes in Human Muscle.

    PubMed

    Schnepp, Bruce C; Chulay, Jeffrey D; Ye, Guo-Jie; Flotte, Terence R; Trapnell, Bruce C; Johnson, Philip R

    2016-01-01

    Gene augmentation therapy as a strategy to treat alpha-1 antitrypsin (AAT) deficiency has reached phase 2 clinical testing in humans. Sustained serum levels of AAT have been observed beyond one year after intramuscular administration of a recombinant adeno-associated virus (rAAV) vector expressing the AAT gene. In this study, sequential muscle biopsies obtained at 3 and 12 months after vector injection were examined for the presence of rAAV vector genomes. Each biopsy sample contained readily detectable vector DNA, the majority of which existed as double-stranded supercoiled and open circular episomes. Episomes persisted through 12 months, although at slightly lower levels than observed at 3 months. There was a clear dose response when comparing the low- and mid-vector-dose groups to the high-dose group. The highest absolute copy numbers were found in a high-dose subject, and serum AAT levels at 12 months confirmed that the high-dose group also had the highest sustained serum AAT levels. Sequence analysis revealed that the vast majority of episomes contained double-D inverted terminal repeats ranging from fully intact to severely deleted. Molecular clones of vector genomes derived directly from the biopsies were transcriptionally active, potentially identifying them as the source of serum AAT in the trial subjects. PMID:26650966

  16. Viral vectors: from virology to transgene expression

    PubMed Central

    Bouard, D; Alazard-Dany, N; Cosset, F-L

    2009-01-01

    In the late 1970s, it was predicted that gene therapy would be applied to humans within a decade. However, despite some success, gene therapy has still not become a routine practise in medicine. In this review, we will examine the problems, both experimental and clinical, associated with the use of viral material for transgenic insertion. We shall also discuss the development of viral vectors involving the most important vector types derived from retroviruses, adenoviruses, herpes simplex viruses and adeno-associated viruses. This article is part of a themed section on Vector Design and Drug Delivery. For a list of all articles in this section see the end of this paper, or visit: http://www3.interscience.wiley.com/journal/121548564/issueyear?year=2009 PMID:18776913

  17. Avian Adeno-Associated Virus Vector Efficiently Transduces Neurons in the Embryonic and Post-Embryonic Chicken Brain

    PubMed Central

    Matsui, Ryosuke; Tanabe, Yasuto; Watanabe, Dai

    2012-01-01

    The domestic chicken is an attractive model system to explore the development and function of brain circuits. Electroporation-mediated and retrovirus (including lentivirus) vector-mediated gene transfer techniques have been widely used to introduce genetic material into chicken cells. However, it is still challenging to efficiently transduce chicken postmitotic neurons without harming the cells. To overcome this problem, we searched for a virus vector suitable for gene transfer into chicken neurons, and report here a novel recombinant virus vector derived from avian adeno-associated virus (A3V). A3V vector efficiently transduces neuronal cells, but not non-neuronal cells in the brain. A single A3V injection into a postembryonic chick brain allows gene expression selectively in neuronal cells within 24 hrs. Such rapid and neuron-specific gene transduction raises the possibility that A3V vector can be utilized for studies of memory formation in filial imprinting, which occurs during the early postnatal days. A3V injection into the neural tube near the ear vesicle at early embryonic stage resulted in persistent and robust gene expression until E20.5 in the auditory brainstem. We further devised an A3V-mediated tetracycline (Tet) dependent gene expression system as a tool for studying the auditory circuit, consisting of the nucleus magnocellularis (NM) and nucleus laminaris (NL), that primarily computes interaural time differences (ITDs). Using this Tet system, we can transduce NM neurons without affecting NL neurons. Thus, the A3V technology complements current gene transfer techniques in chicken studies and will contribute to better understanding of the functional organization of neural circuits. PMID:23144948

  18. Transduction of folate receptor cDNA into cervical carcinoma cells using recombinant adeno-associated virions delays cell proliferation in vitro and in vivo.

    PubMed Central

    Sun, X L; Murphy, B R; Li, Q J; Gullapalli, S; Mackins, J; Jayaram, H N; Srivastava, A; Antony, A C

    1995-01-01

    Although folate receptors (FRs) mediate folate uptake into cells, the independent role of FRs in cell proliferation remains unclear. We tested the hypothesis that transduction of FR cDNA in sense or antisense orientation using recombinant adeno-associated virus modulated FR expression and altered proliferation of cervical carcinoma cells (which constitutively overexpress FR genes). We determined that the integration of recombinant adeno-associated virions was not site specific. When compared with untransduced cells, sense and antisense FR cDNA-transduced cells exhibited an increase and decrease in FR mRNA and FR expression on the cell surface, respectively. However, when compared with antisense FR cDNA-transduced and untransduced cells, sense FR cDNA-transduced cells exhibited statistically significant (a) increased in total FRs, (b) smaller colonies, (c) lowered cell proliferation in vitro, and (d) less tumor volume with dramatic prolongation of tumor doubling times (225.6 h vs. 96 h) after transplantation into nude mice. Finally, (f) using single cell-derived transduced clones, an inverse relationship between cell proliferation and FR expression was established (r = 0.90, P < 0.001). Thus, transduction of sense/antisense FR cDNA into cervical carcinoma cells modulated expression of FRs and had an impact on cell proliferation in vitro and in vivo. Images PMID:7657824

  19. Modification of some biological properties of HeLa cells containing adeno-associated virus DNA integrated into chromosome 17.

    PubMed Central

    Walz, C; Schlehofer, J R

    1992-01-01

    Parvoviruses are known to interfere with cellular transformation and carcinogenesis. Since infecting adeno-associated virus (AAV) frequently integrates its DNA into the cellular genome, we analyzed whether this integration influences the transformed phenotype of the human tumor cell line HeLa. Analysis of three independent HeLa cell clones with integrated AAV DNA (HA-3x, HA-16, and HA-28) revealed the following phenotypic changes of these cells: (i) reduced growth rate, (ii) increased serum requirement, (iii) reduced capacity for colony formation in soft agar, (iv) reduced cloning efficiency on plastic, (v) elevated sensitivity to genotoxic agents (N-methyl-N'-nitro-N-nitrosoguanidine, 7,12-dimethylbenz[a]anthracene, human tumor necrosis factor alpha, UV irradiation [256 nm], and heat [42 degrees C]), and (vi) reduced sensitivity to the cytolytic effect of parvovirus H-1. Reduced growth rate and enhanced sensitivity to gamma irradiation were also observed in vivo when tumors from AAV DNA-containing HeLa cells were transplanted into nude mice. This alteration of the biological properties of HeLa cells was independent of the number of AAV genomes integrated, the physical structure of integrated AAV DNA, and the transcription of AAV genes. Integration of AAV DNA was found to occur preferentially on the long arm of chromosome 17 in the three HeLa cell clones analyzed. These findings demonstrate that genomic integration of AAV DNA can alter the biological properties of human tumor cells. Images PMID:1313913

  20. High-Resolution Labeling and Functional Manipulation of Specific Neuron Types in Mouse Brain by Cre-Activated Viral Gene Expression

    PubMed Central

    Kuhlman, Sandra J.; Huang, Z. Josh

    2008-01-01

    We describe a method that combines Cre-recombinase knockin mice and viral-mediated gene transfer to genetically label and functionally manipulate specific neuron types in the mouse brain. We engineered adeno-associated viruses (AAVs) that express GFP, dsRedExpress, or channelrhodopsin (ChR2) upon Cre/loxP recombination-mediated removal of a transcription-translation STOP cassette. Fluorescent labeling was sufficient to visualize neuronal structures with synaptic resolution in vivo, and ChR2 expression allowed light activation of neuronal spiking. The structural dynamics of a specific class of neocortical neuron, the parvalbumin-containing (Pv) fast-spiking GABAergic interneuron, was monitored over the course of a week. We found that although the majority of Pv axonal boutons were stable in young adults, bouton additions and subtractions on axonal shafts were readily observed at a rate of 10.10% and 9.47%, respectively, over 7 days. Our results indicate that Pv inhibitory circuits maintain the potential for structural re-wiring in post-adolescent cortex. With the generation of an increasing number of Cre knockin mice and because viral transfection can be delivered to defined brain regions at defined developmental stages, this strategy represents a general method to systematically visualize the structure and manipulate the function of different cell types in the mouse brain. PMID:18414675

  1. Inhibition and promotion of tumor growth with adeno-associated virus carcinoembryonic antigen vaccine and Toll-like receptor agonists.

    PubMed

    Triozzi, P L; Aldrich, W; Ponnazhagan, S

    2011-12-01

    Carcinoembryonic antigen (CEA) is a cancer vaccines' target. Several features of recombinant adeno-associated virus (rAAV) are attractive for vaccine applications. Combining other viral vector vaccines with Toll-like receptor (TLR) agonists enhances antitumor immunity. Wild-type and CEA transgenic (Tg) mice were immunized with rAAV-expressing CEA, the TLR9 agonist, oligodinucleotide (ODN)1826 and the TLR7 agonist, imiquimod. Mice were challenged with MC38 colon tumor cells and MC38 cells expressing CEA. rAAV-CEA immunization combined with ODN1826 or imiquimod enhanced CEA-specific T-helper 1 immunity and protected against tumor challenge in wild-type but not in CEA-Tg mice. In contrast, immunization with rAAV-CEA in CEA-Tg mice could abrogate the antitumor effects of ODN1826 and promote tumor growth. Compared to wild-type, CEA-Tg mice were characterized by a greater myeloid suppressor cell and T-helper 2 response to TLR agonists and to syngeneic tumors. Depleting PDCA1(+) plasmacytoid dendritic cells and Gr1(+) myeloid cells increased anti-CEA immune responses in CEA-Tg mice to rAAV-CEA-ODN1826 immunization, whereas depleting CD25(+) T cells did not. There are differences in the response of wild-type and CEA-Tg mice to rAAV-CEA, TLR agonists and syngeneic tumor. In CEA-Tg mice, tumor growth can be promoted with rAAV-CEA and TLR agonists. Dendritic and myeloid cells play a regulatory role. PMID:21869824

  2. Frequency and Spectrum of Genomic Integration of Recombinant Adeno-Associated Virus Serotype 8 Vector in Neonatal Mouse Liver▿

    PubMed Central

    Inagaki, Katsuya; Piao, Chuncheng; Kotchey, Nicole M.; Wu, Xiaolin; Nakai, Hiroyuki

    2008-01-01

    Neonatal injection of recombinant adeno-associated virus serotype 8 (rAAV8) vectors results in widespread transduction in multiple organs and therefore holds promise in neonatal gene therapy. On the other hand, insertional mutagenesis causing liver cancer has been implicated in rAAV-mediated neonatal gene transfer. Here, to better understand rAAV integration in neonatal livers, we investigated the frequency and spectrum of genomic integration of rAAV8 vectors in the liver following intraperitoneal injection of 2.0 × 1011 vector genomes at birth. This dose was sufficient to transduce a majority of hepatocytes in the neonatal period. In the first approach, we injected mice with a β-galactosidase-expressing vector at birth and quantified rAAV integration events by taking advantage of liver regeneration in a chronic hepatitis animal model and following partial hepatectomy. In the second approach, we performed a new, quantitative rAAV vector genome rescue assay by which we identified rAAV integration sites and quantified integrations. As a result, we find that at least ∼0.05% of hepatocytes contained rAAV integration, while the average copy number of integrated double-stranded vector genome per cell in the liver was ∼0.2, suggesting concatemer integration. Twenty-three of 34 integrations (68%) occurred in genes, but none of them were near the mir-341 locus, the common rAAV integration site found in mouse hepatocellular carcinoma. Thus, rAAV8 vector integration occurs preferentially in genes at a frequency of 1 in approximately 103 hepatocytes when a majority of hepatocytes are once transduced in the neonatal period. Further studies are warranted to elucidate the relationship between vector dose and integration frequency or spectrum. PMID:18614641

  3. Effects of Adeno-Associated Virus Serotype and Tissue-Specific Expression on Circulating Biomarkers of Propionic Acidemia

    PubMed Central

    Guenzel, Adam J.; Hillestad, Matthew L.; Matern, Dietrich

    2014-01-01

    Abstract Propionic acidemia (PA) is an autosomal recessive inborn error of metabolism caused by deficiency of propionyl-CoA carboxylase (PCC). This enzyme is composed of six PCCA and six PCCB subunits and mediates a critical step in catabolism of odd chain fatty acids and certain amino acids. Current treatment options for PA are limited to stringent dietary restriction of protein consumption and some patients undergo elective liver transplantation. We previously generated a hypomorphic model of PA, designated Pcca−/−(A138T), with 2% of wild-type enzyme activity that mimics many aspects of the human disease. In this study, we used the differing tissue tropisms of adeno-associated virus (AAV) to probe the ability of liver or muscle-directed gene therapy to treat systemic aspects of this disease that affects many cell types. Systemic therapy with muscle-biased AAV1, liver-biased AAV8, and broadly tropic AAVrh10 mediated significant biochemical corrections in circulating propionylcarnitine (C3) and methyl citrate by all vectors. The innate tissue bias of AAV1 and AAV8 gene expression was made more specific by the use of muscle-specific muscle creatine kinase (specifically MCK6) and hepatocyte-specific transthyretin (TTR) promoters, respectively. Under these targeted conditions, both vectors mediated significant long-term correction of circulating metabolites, demonstrating that correction of muscle and likely other tissue types in addition to liver is necessary to fully correct pathology caused by PA. Liver-specific AAV8-TTR-PCCA mediated better correction than AAV1-MCK-PCCA. These data suggest that targeted gene therapy may be a viable alternative to liver transplantation for PA. They also demonstrate the effects of tissue-specific and broad gene therapy on a cell autonomous systemic genetic disease. PMID:25046265

  4. Effects of adeno-associated virus serotype and tissue-specific expression on circulating biomarkers of propionic acidemia.

    PubMed

    Guenzel, Adam J; Hillestad, Matthew L; Matern, Dietrich; Barry, Michael A

    2014-09-01

    Propionic acidemia (PA) is an autosomal recessive inborn error of metabolism caused by deficiency of propionyl-CoA carboxylase (PCC). This enzyme is composed of six PCCA and six PCCB subunits and mediates a critical step in catabolism of odd chain fatty acids and certain amino acids. Current treatment options for PA are limited to stringent dietary restriction of protein consumption and some patients undergo elective liver transplantation. We previously generated a hypomorphic model of PA, designated Pcca(-/-)(A138T), with 2% of wild-type enzyme activity that mimics many aspects of the human disease. In this study, we used the differing tissue tropisms of adeno-associated virus (AAV) to probe the ability of liver or muscle-directed gene therapy to treat systemic aspects of this disease that affects many cell types. Systemic therapy with muscle-biased AAV1, liver-biased AAV8, and broadly tropic AAVrh10 mediated significant biochemical corrections in circulating propionylcarnitine (C3) and methyl citrate by all vectors. The innate tissue bias of AAV1 and AAV8 gene expression was made more specific by the use of muscle-specific muscle creatine kinase (specifically MCK6) and hepatocyte-specific transthyretin (TTR) promoters, respectively. Under these targeted conditions, both vectors mediated significant long-term correction of circulating metabolites, demonstrating that correction of muscle and likely other tissue types in addition to liver is necessary to fully correct pathology caused by PA. Liver-specific AAV8-TTR-PCCA mediated better correction than AAV1-MCK-PCCA. These data suggest that targeted gene therapy may be a viable alternative to liver transplantation for PA. They also demonstrate the effects of tissue-specific and broad gene therapy on a cell autonomous systemic genetic disease. PMID:25046265

  5. Virally mediated Kcnq1 gene replacement therapy in the immature scala media restores hearing in a mouse model of human Jervell and Lange-Nielsen deafness syndrome

    PubMed Central

    Chang, Qing; Wang, Jianjun; Li, Qi; Kim, Yeunjung; Zhou, Binfei; Wang, Yunfeng; Li, Huawei; Lin, Xi

    2015-01-01

    Mutations in the potassium channel subunit KCNQ1 cause the human severe congenital deafness Jervell and Lange-Nielsen (JLN) syndrome. We applied a gene therapy approach in a mouse model of JLN syndrome (Kcnq1−/− mice) to prevent the development of deafness in the adult stage. A modified adeno-associated virus construct carrying a Kcnq1 expression cassette was injected postnatally (P0–P2) into the endolymph, which resulted in Kcnq1 expression in most cochlear marginal cells where native Kcnq1 is exclusively expressed. We also found that extensive ectopic virally mediated Kcnq1 transgene expression did not affect normal cochlear functions. Examination of cochlear morphology showed that the collapse of the Reissner’s membrane and degeneration of hair cells (HCs) and cells in the spiral ganglia were corrected in Kcnq1−/− mice. Electrophysiological tests showed normal endocochlear potential in treated ears. In addition, auditory brainstem responses showed significant hearing preservation in the injected ears, ranging from 20 dB improvement to complete correction of the deafness phenotype. Our results demonstrate the first successful gene therapy treatment for gene defects specifically affecting the function of the stria vascularis, which is a major site affected by genetic mutations in inherited hearing loss. PMID:26084842

  6. Virally mediated Kcnq1 gene replacement therapy in the immature scala media restores hearing in a mouse model of human Jervell and Lange-Nielsen deafness syndrome.

    PubMed

    Chang, Qing; Wang, Jianjun; Li, Qi; Kim, Yeunjung; Zhou, Binfei; Wang, Yunfeng; Li, Huawei; Lin, Xi

    2015-08-01

    Mutations in the potassium channel subunit KCNQ1 cause the human severe congenital deafness Jervell and Lange-Nielsen (JLN) syndrome. We applied a gene therapy approach in a mouse model of JLN syndrome (Kcnq1(-/-) mice) to prevent the development of deafness in the adult stage. A modified adeno-associated virus construct carrying a Kcnq1 expression cassette was injected postnatally (P0-P2) into the endolymph, which resulted in Kcnq1 expression in most cochlear marginal cells where native Kcnq1 is exclusively expressed. We also found that extensive ectopic virally mediated Kcnq1 transgene expression did not affect normal cochlear functions. Examination of cochlear morphology showed that the collapse of the Reissner's membrane and degeneration of hair cells (HCs) and cells in the spiral ganglia were corrected in Kcnq1(-/-) mice. Electrophysiological tests showed normal endocochlear potential in treated ears. In addition, auditory brainstem responses showed significant hearing preservation in the injected ears, ranging from 20 dB improvement to complete correction of the deafness phenotype. Our results demonstrate the first successful gene therapy treatment for gene defects specifically affecting the function of the stria vascularis, which is a major site affected by genetic mutations in inherited hearing loss. PMID:26084842

  7. Adeno-associated virus sensitizes HeLa cell tumors to gamma rays.

    PubMed Central

    Walz, C; Schlehofer, J R; Flentje, M; Rudat, V; zur Hausen, H

    1992-01-01

    Infection with the helper virus-dependent human parvovirus adeno-associated virus (AAV) is known to interfere with cellular transformation in vitro and oncogenesis in vivo. Here we report on sensitization to gamma irradiation by AAV infection of cells in culture and of tumors established from HeLa cells grafted into immunodeficient (nude) mice: infection of HeLa cells with AAV type 2 enhanced cell killing and reduced plating efficiency after irradiation compared with uninfected cells. Similarly, HeLa cell tumors in nude mice displayed a reduced growth rate and were more sensitive to gamma irradiation when the animals were infected with AAV type 2 prior to or after tumor cell inoculation. Since no pathogenicity is known for AAV, the ability of this virus to render radiotherapy of human tumor cells more efficient may up open novel approaches in cancer treatment. Images PMID:1323717

  8. Biophysical and Ultrastructural Characterization of Adeno-Associated Virus Capsid Uncoating and Genome Release

    PubMed Central

    Horowitz, Eric D.; Rahman, K. Shefaet; Bower, Brian D.; Dismuke, David J.; Falvo, Michael R.; Griffith, Jack D.

    2013-01-01

    We describe biophysical and ultrastructural differences in genome release from adeno-associated virus (AAV) capsids packaging wild-type DNA, recombinant single-stranded DNA (ssDNA), or dimeric, self-complementary DNA (scDNA) genomes. Atomic force microscopy and electron microscopy (EM) revealed that AAV particles release packaged genomes and undergo marked changes in capsid morphology upon heating in physiological buffer (pH 7.2). When different AAV capsids packaging ss/scDNA varying in length from 72 to 123% of wild-type DNA (3.4 to 5.8 kb) were incrementally heated, the proportion of uncoated AAV capsids decreased with genome length as observed by EM. Genome release was further characterized by a fluorimetric assay, which demonstrated that acidic pH and high osmotic pressure suppress genome release from AAV particles. In addition, fluorimetric analysis corroborated an inverse correlation between packaged genome length and the temperature needed to induce uncoating. Surprisingly, scAAV vectors required significantly higher temperatures to uncoat than their ssDNA-packaging counterparts. However, externalization of VP1 N termini appears to be unaffected by packaged genome length or self-complementarity. Further analysis by tungsten-shadowing EM revealed striking differences in the morphologies of ssDNA and scDNA genomes upon release from intact capsids. Computational modeling and molecular dynamics simulations suggest that the unusual thermal stability of scAAV vectors might arise from partial base pairing and optimal organization of packaged scDNA. Our work further defines the biophysical mechanisms underlying adeno-associated virus uncoating and genome release. PMID:23269804

  9. Biodistribution of adeno-associated virus serotype 9 (AAV9) vector after intrathecal and intravenous delivery in mouse

    PubMed Central

    Schuster, Daniel J.; Dykstra, Jaclyn A.; Riedl, Maureen S.; Kitto, Kelley F.; Belur, Lalitha R.; McIvor, R. Scott; Elde, Robert P.; Fairbanks, Carolyn A.; Vulchanova, Lucy

    2014-01-01

    Adeno-associated virus serotype 9 (AAV9)-mediated gene transfer has been reported in central nervous system (CNS) and peripheral tissues. The current study compared the pattern of expression of Green Fluorescent Protein (GFP) across the mouse CNS and selected peripheral tissues after intrathecal (i.t.) or intravenous (i.v.) delivery of equivalent doses of single-stranded AAV9 vector. After i.t. delivery, GFP immunoreactivity (-ir) was observed in spinal neurons, primary afferent fibers and corresponding primary sensory neurons at all spinal levels. Robust transduction was seen in small and large dorsal root ganglion (DRG) neurons as well as trigeminal and vagal primary afferent neurons. Transduction efficiency in sensory ganglia was substantially lower in i.v. treated mice. In brain, i.v. delivery yielded GFP-immunoreactivity (-ir) primarily in spinal trigeminal tract, pituitary, and scattered isolated neurons and astrocytes. In contrast, after i.t. delivery, GFP-ir was widespread throughout CNS, with greater intensity and more abundant neuropil-like staining at 6 weeks compared to 3 weeks. Brain regions with prominent GFP-ir included cranial nerve nuclei, ventral pons, cerebellar cortex, hippocampus, pituitary, choroid plexus, and selected nuclei of midbrain, thalamus and hypothalamus. In cortex, GFP-ir was associated with blood vessels, and was seen in both neurons and astrocytes. In the periphery, GFP-ir in colon and ileum was present in the enteric nervous system in both i.v. and i.t. treated mice. Liver and adrenal cortex, but not adrenal medulla, also showed abundant GFP-ir after both routes of delivery. In summary, i.t. delivery yielded higher transduction efficiency in sensory neurons and the CNS. The observation of comparable gene transfer to peripheral tissues using the two routes indicates that a component of i.t. delivered vector is redistributed from the subarachnoid space to the systemic circulation. PMID:24959122

  10. Biodistribution of adeno-associated virus serotype 9 (AAV9) vector after intrathecal and intravenous delivery in mouse.

    PubMed

    Schuster, Daniel J; Dykstra, Jaclyn A; Riedl, Maureen S; Kitto, Kelley F; Belur, Lalitha R; McIvor, R Scott; Elde, Robert P; Fairbanks, Carolyn A; Vulchanova, Lucy

    2014-01-01

    Adeno-associated virus serotype 9 (AAV9)-mediated gene transfer has been reported in central nervous system (CNS) and peripheral tissues. The current study compared the pattern of expression of Green Fluorescent Protein (GFP) across the mouse CNS and selected peripheral tissues after intrathecal (i.t.) or intravenous (i.v.) delivery of equivalent doses of single-stranded AAV9 vector. After i.t. delivery, GFP immunoreactivity (-ir) was observed in spinal neurons, primary afferent fibers and corresponding primary sensory neurons at all spinal levels. Robust transduction was seen in small and large dorsal root ganglion (DRG) neurons as well as trigeminal and vagal primary afferent neurons. Transduction efficiency in sensory ganglia was substantially lower in i.v. treated mice. In brain, i.v. delivery yielded GFP-immunoreactivity (-ir) primarily in spinal trigeminal tract, pituitary, and scattered isolated neurons and astrocytes. In contrast, after i.t. delivery, GFP-ir was widespread throughout CNS, with greater intensity and more abundant neuropil-like staining at 6 weeks compared to 3 weeks. Brain regions with prominent GFP-ir included cranial nerve nuclei, ventral pons, cerebellar cortex, hippocampus, pituitary, choroid plexus, and selected nuclei of midbrain, thalamus and hypothalamus. In cortex, GFP-ir was associated with blood vessels, and was seen in both neurons and astrocytes. In the periphery, GFP-ir in colon and ileum was present in the enteric nervous system in both i.v. and i.t. treated mice. Liver and adrenal cortex, but not adrenal medulla, also showed abundant GFP-ir after both routes of delivery. In summary, i.t. delivery yielded higher transduction efficiency in sensory neurons and the CNS. The observation of comparable gene transfer to peripheral tissues using the two routes indicates that a component of i.t. delivered vector is redistributed from the subarachnoid space to the systemic circulation. PMID:24959122

  11. Recombinant adeno-associated virus-mediated global anterograde delivery of glial cell line-derived neurotrophic factor to the spinal cord: comparison of rubrospinal and corticospinal tracts in the rat.

    PubMed

    Foust, Kevin D; Flotte, Terence R; Reier, Paul J; Mandel, Ronald J

    2008-01-01

    Amyotrophic lateral sclerosis (ALS) is characterized by progressive loss of spinal lower motoneurons. Gene delivery is a promising strategy to deliver therapeutic molecules to these vulnerable cells. However, definition of an optimal route of delivery capable of accessing neurons over a considerable extent of the neuraxis represents a significant logistical problem. Intramuscular vector injections are not ideal as this approach would involve hundreds of injections to completely treat an ALS patient and also would be dependent on retrograde transport of the viral platform of choice. Alternatively, upper motoneurons could deliver trophic factors over considerable distances by anterograde transport after a relatively localized intracerebral injection. To test this approach, the present study was designed to compare the corticospinal (CST) and rubrospinal (RST) tracts for their ability to transport recombinant adeno-associated virus serotype 5 (rAAV5)-derived green fluorescent protein (GFP) or glial cell line-derived neurotrophic factor (GDNF) to the spinal cord. Unilateral injections of rAAV5-GFP into the red nucleus (RN) or motor cortex of normal rats produced GFP-positive fibers in the appropriate descending tracts extending to the lumbar spinal cord. For both tracts, GFP-positive axonal projections into the spinal gray matter were consistently observed. GDNF immunohistochemistry demonstrated that confirmed RN injections resulted in GDNF-positive fibers projecting into spinal gray matter as seen in the GFP group. In contrast, confirmed cortical rAAV5-GDNF injections resulted in less evident staining in spinal cord. Spinal cord GDNF levels were elevated at distances up to 72 mm from the injection sites, and confirmed that RST-related GDNF transport to spinal cord surpassed CST-associated delivery. PMID:18072858

  12. Comprehensive Small RNA-Seq of Adeno-Associated Virus (AAV)-Infected Human Cells Detects Patterns of Novel, Non-Coding AAV RNAs in the Absence of Cellular miRNA Regulation.

    PubMed

    Stutika, Catrin; Mietzsch, Mario; Gogol-Döring, Andreas; Weger, Stefan; Sohn, Madlen; Chen, Wei; Heilbronn, Regine

    2016-01-01

    Most DNA viruses express small regulatory RNAs, which interfere with viral or cellular gene expression. For adeno-associated virus (AAV), a small ssDNA virus with a complex biphasic life cycle miRNAs or other small regulatory RNAs have not yet been described. This is the first comprehensive Illumina-based RNA-Seq analysis of small RNAs expressed by AAV alone or upon co-infection with helper adenovirus or HSV. Several hotspots of AAV-specific small RNAs were detected mostly close to or within the AAV-ITR and apparently transcribed from the newly identified anti-p5 promoter. An additional small RNA hotspot was located downstream of the p40 promoter, from where transcription of non-coding RNAs associated with the inhibition of adenovirus replication were recently described. Parallel detection of known Ad and HSV miRNAs indirectly validated the newly identified small AAV RNA species. The predominant small RNAs were analyzed on Northern blots and by human argonaute protein-mediated co-immunoprecipitation. None of the small AAV RNAs showed characteristics of bona fide miRNAs, but characteristics of alternative RNA processing indicative of differentially regulated AAV promoter-associated small RNAs. Furthermore, the AAV-induced regulation of cellular miRNA levels was analyzed at different time points post infection. In contrast to other virus groups AAV infection had virtually no effect on the expression of cellular miRNA, which underscores the long-established concept that wild-type AAV infection is apathogenic. PMID:27611072

  13. Adeno-Associated Virus-Mediated Correction of a Canine Model of Glycogen Storage Disease Type Ia

    PubMed Central

    Weinstein, David A.; Correia, Catherine E.; Conlon, Thomas; Specht, Andrew; Verstegen, John; Onclin-Verstegen, Karine; Campbell-Thompson, Martha; Dhaliwal, Gurmeet; Mirian, Layla; Cossette, Holly; Falk, Darin J.; Germain, Sean; Clement, Nathalie; Porvasnik, Stacy; Fiske, Laurie; Struck, Maggie; Ramirez, Harvey E.; Jordan, Juan; Andrutis, Karl; Chou, Janice Y.; Byrne, Barry J.

    2010-01-01

    Abstract Glycogen storage disease type Ia (GSDIa; von Gierke disease; MIM 232200) is caused by a deficiency in glucose-6-phosphatase-α. Patients with GSDIa are unable to maintain glucose homeostasis and suffer from severe hypoglycemia, hepatomegaly, hyperlipidemia, hyperuricemia, and lactic acidosis. The canine model of GSDIa is naturally occurring and recapitulates almost all aspects of the human form of disease. We investigated the potential of recombinant adeno-associated virus (rAAV) vector-based therapy to treat the canine model of GSDIa. After delivery of a therapeutic rAAV2/8 vector to a 1-day-old GSDIa dog, improvement was noted as early as 2 weeks posttreatment. Correction was transient, however, and by 2 months posttreatment the rAAV2/8-treated dog could no longer sustain normal blood glucose levels after 1 hr of fasting. The same animal was then dosed with a therapeutic rAAV2/1 vector delivered via the portal vein. Two months after rAAV2/1 dosing, both blood glucose and lactate levels were normal at 4 hr postfasting. With more prolonged fasting, the dog still maintained near-normal glucose concentrations, but lactate levels were elevated by 9 hr, indicating that partial correction was achieved. Dietary glucose supplementation was discontinued starting 1 month after rAAV2/1 delivery and the dog continues to thrive with minimal laboratory abnormalities at 23 months of age (18 months after rAAV2/1 treatment). These results demonstrate that delivery of rAAV vectors can mediate significant correction of the GSDIa phenotype and that gene transfer may be a promising alternative therapy for this disease and other genetic diseases of the liver. PMID:20163245

  14. Laser-evoked synaptic transmission in cultured hippocampal neurons expressing Channelrhodopsin-2 delivered by adeno-associated virus

    PubMed Central

    Wang, Jennifer; Hasan, Mazahir T.; Seung, H. Sebastian

    2009-01-01

    We present a method for studying synaptic transmission in mass cultures of dissociated hippocampal neurons based on patch clamp recording combined with laser stimulation of neurons expressing Channelrhodopsin-2 (ChR2). Our goal was to use the high spatial resolution of laser illumination to come as close as possible to the ideal of identifying monosynaptically coupled pairs of neurons, which is conventionally done using microisland rather than mass cultures. Using recombinant adeno-associated virus (rAAV) to deliver the ChR2 gene, we focused on the time period between 14 and 20 days in vitro, during which expression levels are high, and spontaneous bursting activity has not yet started. Stimulation by wide-field illumination is sufficient to make the majority of ChR2-expressing neurons spike. Stimulation with a laser spot at least 10 μm in diameter also produces action potentials, but in a reduced fraction of neurons. We studied synaptic transmission by voltage-clamping a neuron with low expression of ChR2 and scanning a 40 μm laser spot at surrounding locations. Responses were observed to stimulation at a subset of locations in the culture, indicating spatial localization of stimulation. Pharmacological means were used to identify responses that were synaptic. Many responses were of smaller amplitude than those typically found in microisland cultures. We were unable to find an entirely reliable criterion for distinguishing between monosynaptic and polysynaptic responses. However, we propose that postsynaptic currents with small amplitudes, simple shapes, and latencies not much greater than 8 msec are reasonable candidates for monosynaptic interactions. PMID:19560489

  15. Interferon-stimulated genes: roles in viral pathogenesis

    PubMed Central

    Schoggins, John W.

    2014-01-01

    Interferon-stimulated genes (ISGs) are critical for controlling virus infections. As new antiviral ISGs continue to be identified and characterized, their roles in viral pathogenesis are also being explored in more detail. Our current understanding of how ISGs impact viral pathogenesis comes largely from studies in knockout mice, with isolated examples from human clinical data. This review outlines recent developments on the contributions of various ISGs to viral disease outcomes in vivo. PMID:24713352

  16. Engineering Biomaterial Systems to Enhance Viral Vector Gene Delivery

    PubMed Central

    Jang, Jae-Hyung; Schaffer, David V; Shea, Lonnie D

    2011-01-01

    Integrating viral gene delivery with engineered biomaterials is a promising strategy to overcome a number of challenges associated with virus-mediated gene delivery, including inefficient delivery to specific cell types, limited tropism, spread of vectors to distant sites, and immune responses. Viral vectors can be combined with biomaterials either through encapsulation within the material or immobilization onto a material surface. Subsequent biomaterial-based delivery can increase the vector's residence time within the target site, thereby potentially providing localized delivery, enhancing transduction, and extending the duration of gene expression. Alternatively, physical or chemical modification of viral vectors with biomaterials can be employed to modulate the tropism of viruses or reduce inflammatory and immune responses, both of which may benefit transduction. This review describes strategies to promote viral gene delivery technologies using biomaterials, potentially providing opportunities for numerous applications of gene therapy to inherited or acquired disorders, infectious disease, and regenerative medicine. PMID:21629221

  17. Adeno-Associated Virus-Like Particles as New Carriers for B-Cell Vaccines: Testing Immunogenicity and Safety in BALB/c Mice

    PubMed Central

    Manzano-Szalai, Krisztina; Thell, Kathrin; Willensdorfer, Anna; Weghofer, Margit; Pfanzagl, Beatrix; Singer, Josef; Ritter, Mirko; Stremnitzer, Caroline; Flaschberger, Ingo; Michaelis, Uwe

    2014-01-01

    Abstract Adeno-associated viruses (AAVs) are established vectors for gene therapy of different human diseases. AAVs are assembled of 60 capsomers, which can be genetically modified, allowing high-density display of short peptide sequences at their surface. The aim of our study was to evaluate the immunogenicity and safety of an adeno-associated virus-like particle (AAVLP)-displayed B-cell peptide epitope taking ovalbumin (OVA) as a model antigen or allergen from egg, respectively. An OVA-derived B-cell epitope was expressed as fusion protein with the AAV-2 capsid protein of VP3 (AAVLP-OVA) and for control, with the nonrelated peptide TP18 (AAVLP-TP18). Cellular internalization studies revealed an impaired uptake of AAVLP-OVA by mouse BMDC, macrophages, and human HeLa cells. Nevertheless, BALB/c mice immunized subcutaneously with AAVLP-OVA formed similarly high titers of OVA-specific IgG1 compared to mice immunized with the native OVA. The extent of the immune response was independent whether aluminum hydroxide or water in oil emulsion was used as adjuvant. Furthermore, in mice immunized with native OVA, high OVA-specific IgE levels were observed, which permitted OVA-specific mast-cell degranulation in a β-hexosaminidase release assay, whereas immunizations with AAVLP-OVA rendered background IgE levels only. Accordingly, OVA-immunized mice, but not AAVLP-OVA immunized mice, displayed an anaphylactic reaction with a significant drop of body temperature upon intravenous OVA challenge. From this mouse model, we conclude that AAVLPs that display B-cell epitope peptides on their surface are suitable vaccine candidates, especially in the field of allergy. PMID:25247267

  18. Use of a three-dimensional humanized liver model for the study of viral gene vectors.

    PubMed

    Wagner, Anke; Röhrs, Viola; Materne, Eva-Maria; Hiller, Thomas; Kedzierski, Radoslaw; Fechner, Henry; Lauster, Roland; Kurreck, Jens

    2015-10-20

    Reconstituted three-dimensional (3D) liver models obtained by engrafting hepatic cells into an extracellular matrix (ECM) are valuable tools to study tissue regeneration, drug action and toxicology ex vivo. The aim of the present study was to establish a system for the functional investigation of a viral vector in a 3D liver model composed of human HepG2 cells on a rat ECM. An adeno-associated viral (AAV) vector expressing the Emerald green fluorescent protein (EmGFP) and a short hairpin RNA (shRNA) directed against human cyclophilin b (hCycB) was injected into the portal vein of 3D liver models. Application of the vector did not exert toxic effects, as shown by analysis of metabolic parameters. Six days after transduction, fluorescence microscopy analysis of EmGFP production revealed widespread distribution of the AAV vectors. After optimization of the recellularization and transduction conditions, averages of 55 and 90 internalized vector genomes per cell in two replicates of the liver model were achieved, as determined by quantitative PCR analysis. Functionality of the AAV vector was confirmed by efficient shRNA-mediated knockdown of hCycB by 70-90%. Our study provides a proof-of-concept that a recellularized biological ECM provides a valuable model to study viral vectors ex vivo. PMID:26356676

  19. Effects of Adeno-Associated Virus DNA Hairpin Structure on Recombination‡

    PubMed Central

    Choi, Vivian W.; Samulski, R. Jude; McCarty, Douglas M.

    2005-01-01

    Hairpin DNA ends are evolutionarily conserved intermediates in DNA recombination. The hairpin structures present on the ends of the adeno-associated virus (AAV) genome are substrates for recombination that give rise to persistent circular and concatemeric DNA episomes through intramolecular and intermolecular recombination, respectively. We have developed circularization-dependent and orientation-specific self-complementary AAV (scAAV) vectors as a reporter system to examine recombination events involving distinct hairpin structures, i.e., closed versus open hairpins. The results suggest that intramolecular recombination (circularization) is far more efficient than intermolecular recombination (concatemerization). Among all possible combinations of terminal repeats (TRs) involved in intermolecular recombination, the closed-closed TR structures are twice as efficient as the open-open TR substrates for recombination. In addition, both intramolecular recombination and intermolecular recombination exhibit the common dependency on specific DNA polymerases and topoisomerases. The circularization-dependent and orientation-specific scAAV vectors can serve as an efficient and controlled system for the delivery of DNA structures that mimic mammalian recombination intermediates and should be useful in assaying recombination in different experimental settings as well as elucidating the molecular mechanism of recombinant AAV genome persistence. PMID:15890919

  20. Prevalence and genetic diversity of adeno-associated viruses in bats from China.

    PubMed

    Li, Yan; Ge, Xingyi; Hon, Chung-Chau; Zhang, Huajun; Zhou, Peng; Zhang, Yunzhi; Wu, Yi; Wang, Lin-Fa; Shi, Zhengli

    2010-10-01

    Bats are increasingly being recognized as important natural reservoirs of different viruses. Adeno-associated viruses (AAVs) are widely distributed in primates and their distribution in bats is unknown. In this study, a total of 370 faecal swab samples from 19 bat species were collected from various provinces of China and examined for the presence of AAVs. The mean prevalence rate was 22.4% (83 positives out of 370 samples), ranging from 10 to 38.9% among different bat species. The genome sequence spanning the entire rep-cap ORFs was determined from one chosen AAV-positive sample (designated BtAAV-YNM). Phylogenetic analysis of the entire rep-cap ORF coding sequences suggested that BtAAV-YNM is relatively distant to known primate AAVs, but phylogenetically closer to porcine AAV strain Po3. Further analysis of the partial cap ORF sequences of bat AAV samples (n=49) revealed a remarkably large genetic diversity, with an average pairwise nucleotide identity of only 84.3%. Co-presence of multiple distinctive genotypes of bat AAV within an individual sample was also observed. These results demonstrated that diverse AAVs might be widely distributed in bat populations. PMID:20573859

  1. Protection against henipavirus infection by use of recombinant adeno-associated virus-vector vaccines.

    PubMed

    Ploquin, Aurélie; Szécsi, Judit; Mathieu, Cyrille; Guillaume, Vanessa; Barateau, Véronique; Ong, Kien Chai; Wong, Kum Thong; Cosset, François-Loïc; Horvat, Branka; Salvetti, Anna

    2013-02-01

    Nipah virus (NiV) and Hendra virus (HeV) are closely related, recently emerged paramyxoviruses that are capable of causing considerable morbidity and mortality in several mammalian species, including humans. Henipavirus-specific vaccines are still commercially unavailable, and development of novel antiviral strategies to prevent lethal infections due to henipaviruses is highly desirable. Here we describe the development of adeno-associated virus (AAV) vaccines expressing the NiV G protein. Characterization of these vaccines in mice demonstrated that a single intramuscular AAV injection was sufficient to induce a potent and long-lasting antibody response. Translational studies in hamsters further demonstrated that all vaccinated animals were protected against lethal challenge with NiV. In addition, this vaccine induced a cross-protective immune response that was able to protect 50% of the animals against a challenge by HeV. This study presents a new efficient vaccination strategy against henipaviruses and opens novel perspectives on the use of AAV vectors as vaccines against emergent diseases. PMID:23175762

  2. Functional analysis of the putative integrin recognition motif on adeno-associated virus 9.

    PubMed

    Shen, Shen; Berry, Garrett E; Castellanos Rivera, Ruth M; Cheung, Roland Y; Troupes, Andrew N; Brown, Sarah M; Kafri, Tal; Asokan, Aravind

    2015-01-16

    Adeno-associated viruses (AAVs) display a highly conserved NGR motif on the capsid surface. Earlier studies have established this tripeptide motif as being essential for integrin-mediated uptake of recombinant AAV serotype 2 (AAV2) in cultured cells. However, functional attributes of this putative integrin recognition motif in other recombinant AAV serotypes displaying systemic transduction in vivo remain unknown. In this study, we dissect the biology of an integrin domain capsid mutant derived from the human isolate AAV9 in mice. The AAV9/NGA mutant shows decreased systemic transduction in mice. This defective phenotype was accompanied by rapid clearance of mutant virions from the blood circulation and nonspecific sequestration by the spleen. Transient vascular hyperpermeability, induced by histamine coinjection, exacerbated AAV9/NGA uptake by the spleen but not the liver. However, such treatment did not affect AAV9 virions, suggesting a potential entry/post-entry defect for the mutant in different tissues. Further characterization revealed modestly decreased cell surface binding but a more pronounced defect in the cellular entry of mutant virions. These findings were corroborated by the observation that blocking multiple integrins adversely affected recombinant AAV9 transduction in different cell types, albeit with variable efficiencies. From a structural perspective, we observed that the integrin recognition motif is located in close proximity to the galactose binding footprint on AAV9 capsids and postulate that this feature could influence cell surface attachment, cellular uptake at the tissue level, and systemic clearance by the reticuloendothelial system. PMID:25404742

  3. A Precise Chemical Strategy To Alter the Receptor Specificity of the Adeno-Associated Virus.

    PubMed

    Kelemen, Rachel E; Mukherjee, Raja; Cao, Xiaofu; Erickson, Sarah B; Zheng, Yunan; Chatterjee, Abhishek

    2016-08-26

    The ability to target the adeno-associated virus (AAV) to specific types of cells, by altering the cell-surface receptor it binds, is desirable to generate safe and efficient therapeutic vectors. Chemical attachment of receptor-targeting agents onto the AAV capsid holds potential to alter its tropism, but is limited by the lack of site specificity of available conjugation strategies. The development of an AAV production platform is reported that enables incorporation of unnatural amino acids (UAAs) into specific sites on the virus capsid. Incorporation of an azido-UAA enabled site-specific attachment of a cyclic-RGD peptide onto the capsid, retargeting the virus to the αv β3 integrin receptors, which are overexpressed in tumor vasculature. Retargeting ability was site-dependent, underscoring the importance of achieving site-selective capsid modification. This work provides a general chemical approach to introduce various receptor binding agents onto the AAV capsid with site selectivity to generate optimized vectors with engineered infectivity. PMID:27483453

  4. Non Viral Vectors in Gene Therapy- An Overview

    PubMed Central

    Narvekar, Aparna

    2015-01-01

    Non-viral vectors are simple in theory but complex in practice. Apart from intra cellular and extracellular barriers, number of other challenges also needs to be overcome in order to increase the effectiveness of non-viral gene transfer. These barriers are categorized as production, formulation and storage. No one-size-fits-all solution to gene delivery, which is why in spite of various developments in liposome, polymer formulation and optimization, new compounds are constantly being proposed and investigated. In this review, we will see in detail about various types of non-viral vectors highlighting promising development and recent advances that had improved the non-viral gene transfer efficiency of translating from “Bench to bedside”. PMID:25738007

  5. Adeno-Associated Virus-Mediated Overexpression of LARGE Rescues α-Dystroglycan Function in Dystrophic Mice with Mutations in the Fukutin-Related Protein

    PubMed Central

    Vannoy, Charles H.; Xu, Lei; Keramaris, Elizabeth; Lu, Pei; Xiao, Xiao

    2014-01-01

    Abstract Multiple genes (e.g., POMT1, POMT2, POMGnT1, ISPD, GTDC2, B3GALNT2, FKTN, FKRP, and LARGE) are known to be involved in the glycosylation pathway of α-dystroglycan (α-DG). Mutations of these genes result in muscular dystrophies with wide phenotypic variability. Abnormal glycosylation of α-DG with decreased extracellular ligand binding activity is a common biochemical feature of these genetic diseases. While it is known that LARGE overexpression can compensate for defects in a few aforementioned genes, it is unclear whether it can also rescue defects in FKRP function. We examined adeno-associated virus (AAV)-mediated LARGE or FKRP overexpression in two dystrophic mouse models with loss-of-function mutations: (1) Largemyd (LARGE gene) and (2) FKRPP448L (FKRP gene). The results agree with previous findings that overexpression of LARGE can ameliorate the dystrophic phenotypes of Largemyd mice. In addition, LARGE overexpression in the FKRPP448L mice effectively generated functional glycosylation (hyperglycosylation) of α-DG and improved dystrophic pathologies in treated muscles. Conversely, FKRP transgene overexpression failed to rescue the defect in glycosylation and improve the phenotypes of the Largemyd mice. Our findings suggest that AAV-mediated LARGE gene therapy may still be a viable therapeutic strategy for dystroglycanopathies with FKRP deficiency. PMID:24635668

  6. A 110-kDa nuclear shuttle protein, nucleolin, specifically binds to adeno-associated virus type 2 (AAV-2) capsid.

    PubMed

    Qiu, J; Brown, K E

    1999-05-10

    A 110-kDa protein was copurified with adeno-associated virus type 2 (AAV-2) virions after CsCl density gradient isopycnic centrifugation. Amino acid sequence of peptides derived from this protein after tryptic digestion, monoclonal antibody production, and Western blot analysis showed that the copurified protein was the major nucleolar phosphoprotein, human nucleolin. Virus overlay assays demonstrated that AAV-2 capsid specifically bound to the human nucleolin, and immunoprecipitation studies confirmed the in vitro binding of nucleolin and intact AAV-2 capsids but not denatured viral proteins. Double-immunofluorescence staining of infected cells showed that AAV capsid and nucleolin were colocalized in both cytoplasm and nucleus. In addition, when cytoplasmic and nuclear fractions were extracted from AAV-infected KB cells at different time points postinfection, immunoprecipitation data and Western blotting showed that AAV capsid formation and nucleolin interact specifically and share their subcellular localization in infected cells. With the known functions of nucleolin in the synthesis of rRNA and ribosome assembly, binding to single-stranded DNA, and acting as a shuttle between cytoplasm and nucleolus, our data showing that AAV-2 capsid binds specifically to nucleolin both in vitro and in vivo suggest a key role of nucleolin in AAV-2 replication, particularly in capsid assembly. PMID:10329548

  7. Directed Evolution of a Novel Adeno-associated Virus (AAV) Vector That Crosses the Seizure-compromised Blood–Brain Barrier (BBB)

    PubMed Central

    Gray, Steven J; Blake, Bonita L; Criswell, Hugh E; Nicolson, Sarah C; Samulski, R Jude; McCown, Thomas J

    2009-01-01

    DNA shuffling and directed evolution were employed to develop a novel adeno-associated virus (AAV) vector capable of crossing the seizure-compromised blood–brain barrier (BBB) and transducing cells in the brain. Capsid DNA from AAV serotypes 1–6, 8, and 9 were shuffled and recombined to create a library of chimeric AAVs. One day after kainic acid–induced limbic seizure activity in rats, the virus library was infused intravenously (i.v.), and 3 days later, neuron-rich cells were mechanically dissociated from seizure-sensitive brain sites, collected and viral DNA extracted. After three cycles of selection, green fluorescent protein (GFP)–packaged clones were administered directly into brain or i.v. 1 day after kainic acid–induced seizures. Several clones that were effective after intracranial administration did not transduce brain cells after the i.v. administration. However, two clones (32 and 83) transduced the cells after direct brain infusion and after i.v. administration transduced the cells that were localized to the piriform cortex and ventral hippocampus, areas exhibiting a seizure-compromised BBB. No transduction occurred in areas devoid of BBB compromise. Only one parental serotype (AAV8) exhibited a similar expression profile, but the biodistribution of 32 and 83 diverged dramatically from this parental serotype. Thus, novel AAV vectors have been created that can selectively cross the seizure-compromised BBB and transduce cells. PMID:20040913

  8. Molecular detection of adeno-associated virus in cases of spontaneous and intentional human abortion.

    PubMed

    Pereira, Christiane Curi; de Freitas, Luciana Bueno; de Vargas, Paulo Roberto Merçon; de Azevedo, Maria Luiza Borges; do Nascimento, Jussara Pereira; Spano, Liliana Cruz

    2010-10-01

    Pregnancy failure is a common event and often of unknown cause. Some viruses are thought to cause abortions including the adeno-associated viruses (AAV), viruses which are regarded as being without any definitive association to any human disease. This study investigated AAV infection in 81 human abortions, both spontaneous and intentional that occurred up to the 23rd week of gestation. Nucleic acid of AAV-2, 3, and 5 types from 118 decidual and chorionic tissues, collected from the patients in this study, was amplified by nested-PCR. In situ hybridization (ISH) was developed with a digoxigenin-labeled AAV probe in paraffin embedded tissues from the AAV positive cases. AAV was observed in 28.4% (23/81) of the cases, of which, 78.3% (18/23) were in the decidua and 21.7% (5/23) in the extravillous trophoblast, the chorionic plate, or chorionic villi fragments. AAV-2, the only type detected, occurred in 32.3% (22/68) and in 7.7% (1/13) of the spontaneous and intentional abortions, respectively. ISH revealed AAV in the decidua, chorionic tissue or chorionic plate and extravillous trophoblast. The detection of only AAV-2 type indicates that it is the most frequent in the population studied and/or shows tissue tropism. The presence of AAV in decidual or trophoblastic cells in cases of abortion, as observed by ISH, implies that the virus could jeopardize the pregnancy. The significant predominance in spontaneous cases suggests possibly a causal association between AAV and abortion. PMID:20827766

  9. A retrograde adeno-associated virus for collecting ribosome-bound mRNA from anatomically defined projection neurons

    PubMed Central

    Cook-Snyder, Denise R.; Jones, Alexander; Reijmers, Leon G.

    2015-01-01

    The brain contains a large variety of projection neurons with different functional properties. The functional properties of projection neurons arise from their connectivity with other neurons and their molecular composition. We describe a novel tool for obtaining the gene expression profiles of projection neurons that are anatomically defined by the location of their soma and axon terminals. Our tool utilizes adeno-associated virus serotype 9 (AAV9), which we found to retrogradely transduce projection neurons after injection at the site of the axon terminals. We used AAV9 to express Enhanced Green Fluorescent Protein (EGFP)-tagged ribosomal protein L10a (EGFP-L10a), which enables the immunoprecipitation of EGFP-tagged ribosomes and associated mRNA with a method known as Translating Ribosome Affinity Purification (TRAP). To achieve high expression of the EGFP-L10a protein in projection neurons, we placed its expression under control of a 1.3 kb alpha-calcium/calmodulin-dependent protein kinase II (Camk2a) promoter. We injected the AAV9-Camk2a-TRAP virus in either the hippocampus or the bed nucleus of the stria terminalis (BNST) of the mouse brain. In both brain regions the 1.3 kb Camk2a promoter did not confer complete cell-type specificity around the site of injection, as EGFP-L10a expression was observed in Camk2a-expressing neurons as well as in neuronal and non-neuronal cells that did not express Camk2a. In contrast, cell-type specific expression was observed in Camk2a-positive projection neurons that were retrogradely transduced by AAV9-Camk2a-TRAP. Injection of AAV9-Camk2a-TRAP into the BNST enabled the use of TRAP to collect ribosome-bound mRNA from basal amygdala projection neurons that innervate the BNST. AAV9-Camk2a-TRAP provides a single-virus system that can be used for the molecular profiling of anatomically defined projection neurons in mice and other mammalian model organisms. In addition, AAV9-Camk2a-TRAP may enable the discovery of protein synthesis

  10. Recombinant adeno-associated virus expressing human papillomavirus type 16 E7 peptide DNA fused with heat shock protein DNA as a potential vaccine for cervical cancer.

    PubMed

    Liu, D W; Tsao, Y P; Kung, J T; Ding, Y A; Sytwu, H K; Xiao, X; Chen, S L

    2000-03-01

    In this study, we explore a potential vaccine for human papillomavirus (HPV)-induced tumors, using heat shock protein as an adjuvant, a peptide vaccine for safety, and adeno-associated virus (AAV) as a gene delivery vector. The tumor vaccine was devised by constructing a chimeric gene which contained HPV type 16 E7 cytotoxic T-lymphocyte (CTL) epitope DNA (M. C. Feltkamp, H. L. Smits, M. P. Vierboom, R. P. Minnaar, B. M. de Jongh, J. W. Drijfhout, J. ter Schegget, C. J. Melief, and W. M. Kast, Eur. J. Immunol. 23:2242-2249, 1993) fused with the heat shock protein gene as a tumor vaccine delivered via AAV. Our results demonstrate that this vaccine can eliminate tumor cells in syngeneic animals and induce CD4- and CD8-dependent CTL activity in vitro. Moreover, studies with knockout mice with distinct T-cell deficiencies confirm that CTL-induced tumor protection is CD4 and CD8 dependent. Taken together, the evidence indicates that this chimeric gene delivered by AAV has potential as a cervical cancer vaccine. PMID:10684306

  11. Viral mediated gene transfer to sprouting blood vessels during angiogenesis.

    PubMed

    Alian, Akram; Eldor, Amiram; Falk, Haya; Panet, Amos

    2002-08-01

    Several experimental systems have been applied to investigate the development of new blood vessels. Angiogenesis can be followed ex-vivo by culturing explants of rat aorta 'rings' in biomatrix gels. This angiogenesis system was modified for the study of viral vector mediated gene transfer, using adenovirus, vaccinia- and retroviral vectors. Two modifications were introduced to the model in order to facilitate efficient viral mediated gene transfer, (i) placing the aorta ring on top of a thin layer of collagen such that the angiogenic tissue will be accessible to the viral vector; and (ii) infection of the aorta rings prior to embedding them into the collagen matrix. While adenovirus and vaccinia vectors infected efficiently the aorta rings they induced cell death. Subsequent gene transfer experiments were, therefore, carried with retroviral vectors containing vascular endothelial growth factor (VEGF) and the beta-interferon (IFN) genes. Overexpression of VEGF enhanced significantly microvessel sprouting, while overexpression of IFN-beta induced an antiviral effect. The experimental system described in this study can facilitate the application of other viral vectors to the study of genes that may regulate the complex angiogenic process and thereby open new avenues for vascular gene therapy. PMID:12176137

  12. Viral Vectors for Gene Therapy: Current State and Clinical Perspectives.

    PubMed

    Lukashev, A N; Zamyatnin, A A

    2016-07-01

    Gene therapy is the straightforward approach for the application of recent advances in molecular biology into clinical practice. One of the major obstacles in the development of gene therapy is the delivery of the effector to and into the target cell. Unfortunately, most methods commonly used in laboratory practice are poorly suited for clinical use. Viral vectors are one of the most promising methods for gene therapy delivery. Millions of years of evolution of viruses have resulted in the development of various molecular mechanisms for entry into cells, long-term survival within cells, and activation, inhibition, or modification of the host defense mechanisms at all levels. The relatively simple organization of viruses, small genome size, and evolutionary plasticity allow modifying them to create effective instruments for gene therapy approaches. This review summarizes the latest trends in the development of gene therapy, in particular, various aspects and prospects of the development of clinical products based on viral delivery systems. PMID:27449616

  13. 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.

    PubMed

    Weber, Michel; Rabinowitz, Joseph; Provost, Nathalie; Conrath, Hervé; Folliot, Sébastien; Briot, Delphine; Chérel, Yan; Chenuaud, Pierre; Samulski, Jude; Moullier, Philippe; Rolling, Fabienne

    2003-06-01

    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. PMID:12788651

  14. Impurity of recombinant adeno-associated virus type 2 affects the transduction characteristics following subretinal injection in the rat.

    PubMed

    Shen, Wei-Yong; Lai, Yvonne K Y; Lai, Chooi-May; Rakoczy, P Elizabeth

    2004-02-01

    We recently reported that different purification methods of recombinant adeno-associated virus type 2 (rAAV2) affect the transduction characteristics following subretinal injection. In this study, we examined the roles of contaminant proteins from the HEK-293 cells and helper adenovirus, inactivation of helper adenovirus and cell stress induced by DNA-damaging agents in rAAV-mediated retinal transduction. Our results showed that contaminating factors/proteins resulting from the helper E1 deleted adenovirus are possibly responsible for efficient RPE transduction. Future studies of these factors will undoubtedly lead to development of new therapeutic approaches to PR- and RPE-specific retinal diseases. PMID:14659960

  15. Advances in Gene Delivery Systems

    PubMed Central

    Kamimura, Kenya; Suda, Takeshi; Zhang, Guisheng; Liu, Dexi

    2011-01-01

    The transfer of genes into cells, both in vitro and in vivo, is critical for studying gene function and conducting gene therapy. Methods that utilize viral and nonviral vectors, as well as physical approaches, have been explored. Viral vector-mediated gene transfer employs replication-deficient viruses such as retro-virus, adenovirus, adeno-associated virus and herpes simplex virus. A major advantage of viral vectors is their high gene delivery efficiency. The nonviral vectors developed so far include cationic liposomes, cationic polymers, synthetic peptides and naturally occurring compounds. These nonviral vectors appear to be highly effective in gene delivery to cultured cells in vitro but are significantly less effective in vivo. Physical methods utilize mechanical pressure, electric shock or hydrodynamic force to transiently permeate the cell membrane to transfer DNA into target cells. They are simpler than viral- and nonviral-based systems and highly effective for localized gene delivery. The past decade has seen significant efforts to establish the most desirable method for safe, effective and target-specific gene delivery, and good progress has been made. The objectives of this review are to (i) explain the rationale for the design of viral, nonviral and physical methods for gene delivery; (ii) provide a summary on recent advances in gene transfer technology; (iii) discuss advantages and disadvantages of each of the most commonly used gene delivery methods; and (iv) provide future perspectives. PMID:22200988

  16. High-efficiency transduction and specific expression of ChR2opt for optogenetic manipulation of primary cortical neurons mediated by recombinant adeno-associated viruses.

    PubMed

    Jin, Lei; Lange, Wienke; Kempmann, Annika; Maybeck, Vanessa; Günther, Anne; Gruteser, Nadine; Baumann, Arnd; Offenhäusser, Andreas

    2016-09-10

    In recent years, optogenetic approaches have significantly advanced the experimental repertoire of cellular and functional neuroscience. Yet, precise and reliable methods for specific expression of optogenetic tools remain challenging. In this work, we studied the transduction efficiency of seven different adeno-associated virus (AAV) serotypes in primary cortical neurons and revealed recombinant (r) AAV6 to be the most efficient for constructs under control of the cytomegalovirus (CMV) promoter. To further specify expression of the transgene, we exchanged the CMV promoter for the human synapsin (hSyn) promoter. In primary cortical-glial mixed cultures transduced with hSyn promoter-containing rAAVs, expression of ChR2opt (a Channelrhodopsin-2 variant) was limited to neurons. In these neurons action potentials could be reliably elicited upon laser stimulation (473nm). The use of rAAV serotype alone to restrict expression to neurons results in a lower transduction efficiency than the use of a broader transducing serotype with specificity conferred via a restrictive promoter. Cells transduced with the hSyn driven gene expression were able to elicit action potentials with more spatially and temporally accurate illumination than neurons electrofected with the CMV driven construct. The hSyn promoter is particularly suited to use in AAVs due to its small size. These results demonstrate that rAAVs are versatile tools to mediate specific and efficient transduction as well as functional and stable expression of transgenes in primary cortical neurons. PMID:27416794

  17. Short-lived recombinant adeno-associated virus transgene expression in dystrophic muscle is associated with oxidative damage to transgene mRNA

    PubMed Central

    Dupont, Jean-Baptiste; Tournaire, Benoit; Georger, Christophe; Marolleau, Béatrice; Jeanson-Leh, Laurence; Ledevin, Mireille; Lindenbaum, Pierre; Lecomte, Emilie; Cogné, Benjamin; Dubreil, Laurence; Larcher, Thibaut; Gjata, Bernard; Van Wittenberghe, Laetitia; Le Guiner, Caroline; Penaud-Budloo, Magalie; Snyder, Richard O; Moullier, Philippe; Léger, Adrien

    2015-01-01

    Preclinical gene therapy strategies using recombinant adeno-associated virus (AAV) vectors in animal models of Duchenne muscular dystrophy have shown dramatic phenotype improvements, but long-lasting efficacy remains questionable. It is believed that in dystrophic muscles, transgene persistence is hampered, notably by the progressive loss of therapeutic vector genomes resulting from muscle fibers degeneration. Intracellular metabolic perturbations resulting from dystrophin deficiency could also be additional factors impacting on rAAV genomes and transgene mRNA molecular fate. In this study, we showed that rAAV genome loss is not the only cause of reduced transgene mRNA level and we assessed the contribution of transcriptional and post-transcriptional factors. We ruled out the implication of transgene silencing by epigenetic mechanisms and demonstrated that rAAV inhibition occurred mostly at the post-transcriptional level. Since Duchenne muscular dystrophy (DMD) physiopathology involves an elevated oxidative stress, we hypothesized that in dystrophic muscles, transgene mRNA could be damaged by oxidative stress. In the mouse and dog dystrophic models, we found that rAAV-derived mRNA oxidation was increased. Interestingly, when a high expression level of a therapeutic transgene is achieved, oxidation is less pronounced. These findings provide new insights into rAAV transductions in dystrophic muscles, which ultimately may help in the design of more effective clinical trials. PMID:26029721

  18. A scalable method for the production of high-titer and high-quality adeno-associated type 9 vectors using the HSV platform

    PubMed Central

    Adamson-Small, Laura; Potter, Mark; Falk, Darin J; Cleaver, Brian; Byrne, Barry J; Clément, Nathalie

    2016-01-01

    Recombinant adeno-associated vectors based on serotype 9 (rAAV9) have demonstrated highly effective gene transfer in multiple animal models of muscular dystrophies and other neurological indications. Current limitations in vector production and purification have hampered widespread implementation of clinical candidate vectors, particularly when systemic administration is considered. In this study, we describe a complete herpes simplex virus (HSV)-based production and purification process capable of generating greater than 1 × 1014 rAAV9 vector genomes per 10-layer CellSTACK of HEK 293 producer cells, or greater than 1 × 105 vector genome per cell, in a final, fully purified product. This represents a 5- to 10-fold increase over transfection-based methods. In addition, rAAV vectors produced by this method demonstrated improved biological characteristics when compared to transfection-based production, including increased infectivity as shown by higher transducing unit-to-vector genome ratios and decreased total capsid protein amounts, shown by lower empty-to-full ratios. Together, this data establishes a significant improvement in both rAAV9 yields and vector quality. Further, the method can be readily adapted to large-scale good laboratory practice (GLP) and good manufacturing practice (GMP) production of rAAV9 vectors to enable preclinical and clinical studies and provide a platform to build on toward late-phases and commercial production. PMID:27222839

  19. Combined macroscopic and microscopic detection of viral genes in tissues

    SciTech Connect

    Haase, A.T.; Gantz, D.; Blum, H.; Stowring, L.; Ventura, P.; Geballe, A.; Moyer, B.; Brahic, M.

    1985-01-15

    A hybridization technique has been devised for detecting and quantitating viral genes in tissues that combines macroscopic and microscopic analyses in the same section. The method is based on dual labeling virus-specific probes with /sup 125/I and /sup 35/S to generate signals that can be detected both with X-ray films and nuclear track emulsions. The regions of increased hybridization evident in the X-ray film serve as a guide to the portion of the section that warrants microscopic examination. Detection of viral RNA in tissues with Visna virus and viral DNA with hepatitis B virus are illustrated, and potential applications of this technique in virology and other disciplines are discussed.

  20. Development of Viral Vectors for Use in Cardiovascular Gene Therapy

    PubMed Central

    Williams, Paul D.; Ranjzad, Parisa; Kakar, Salik J.; Kingston, Paul A.

    2010-01-01

    Cardiovascular disease represents the most common cause of mortality in the developed world but, despite two decades of promising pre-clinical research and numerous clinical trials, cardiovascular gene transfer has so far failed to demonstrate convincing benefits in the clinical setting. In this review we discuss the various targets which may be suitable for cardiovascular gene therapy and the viral vectors which have to date shown the most potential for clinical use. We conclude with a summary of the current state of clinical cardiovascular gene therapy and the key trials which are ongoing. PMID:21994642

  1. Enhanced efficacy of combination therapy with adeno-associated virus-delivered pigment epithelium-derived factor and cisplatin in a mouse model of Lewis lung carcinoma

    PubMed Central

    HE, SHA-SHA; WU, QIN-JIE; GONG, CHANG YANG; LUO, SHUN-TAO; ZHANG, SHUANG; LI, MENG; LU, LIAN; WEI, YU-QUAN; YANG, LI

    2014-01-01

    Pigment epithelium-derived factor (PEDF) is a potent inhibitor of angiogenesis, and the antitumor effect of adeno-associated virus (AAV)-mediated PEDF expression has been demonstrated in a range of animal models. The combined treatment of low-dose chemotherapy and gene therapy inhibits the growth of solid tumors more effectively than current traditional therapies or gene therapy alone. In the present study, the effect of treatment with an AAV2 vector harboring the human PEDF (hPEDF) gene in combination with low-dose cisplatin on the growth of Lewis lung carcinoma (LLC) in mice was assessed. LLC cells were infected with AAV-enhanced green fluorescent protein (EGFP) in the presence or absence of cisplatin, and then the effect of cisplatin on AAV-mediated gene expression was evaluated by image and flow cytometric analysis. Tumor growth, survival time, vascular endothelial growth factor (VEGF) expression, microvessel density (MVD) and apoptotic index were analyzed in C57BL/6 mice treated with AAV-hPEDF, cisplatin or cisplatin plus AAV-hPEDF. The results of the present study provide evidence that cisplatin treatment is able to enhance AAV-mediated gene expression in LLC cells. In addition, the combined treatment of cisplatin plus AAV-hPEDF markedly prolonged the survival time of the mice and inhibited tumor growth, resulting in significant suppression of tumor angiogenesis and induction of tumor apoptosis in vivo, and also protected against cisplatin-related toxicity. These findings suggest that combination of AAV-hPEDF and cisplatin has potential as a novel therapeutic strategy for lung cancer. PMID:24714917

  2. Gene transfer into hematopoietic progenitor and stem cells: progress and problems.

    PubMed

    Dunbar, C E; Emmons, R V

    1994-11-01

    Gene transfer to hematopoietic cells for the purpose of "gene therapy" is a new and rapidly developing field with clinical trials in progress. A fundamental goal of research in this field is the incorporation of exogenous genes into the chromosomes of the most primitive hematopoietic progenitor cells--stem cells. Recombinantly engineered retroviral vectors are the best characterized and are currently the only vector type in clinical trials directed at the hematopoietic system. High efficiency gene transfer and expression in murine stem cells and their progeny is now routine, but in larger animal models such as dogs or primates and preliminary clinical trials, gene transfer has been less successful. Problems such as retroviral efficiency, gene expression, insertional mutagenesis and helper virus contamination are being addressed. A promising new vector, the adeno-associated virus (AAV), has shown promise and may allow production of high titer, stable, recombinant virions without helper contamination and with potentially better safety parameters. However, the technology for AAV gene transfer is currently underdeveloped, and issues related to the reproducible production of vectors must be addressed. Other non-viral vector systems are being explored, but little data are available on applications to hematopoietic cells. Better preclinical models are needed to study gene targeting and expression in human cells. An overview of recombinant retroviral and adeno-associated viral vector production, preclinical data and preliminary clinical data will be given, and problems needing to be addressed at all stages of development before broad clinical utility can be achieved will be discussed. PMID:7881358

  3. Diversity of viral photosystem-I psaA genes

    PubMed Central

    Hevroni, Gur; Enav, Hagay; Rohwer, Forest; Béjà, Oded

    2015-01-01

    Marine photosynthesis is one of the major contributors to the global carbon cycle and the world's oxygen supply. This process is largely driven by cyanobacteria, namely Synechococcus and Prochlorococcus. Genes encoding photosystem-II (PSII) reaction center proteins are found in many cyanophage genomes, and are expressed during the infection of their hosts. On the basis of metagenomics, cyanophage photosystem-I (PSI) gene cassettes were recently discovered with two gene arrangements psaJF→C→A→B→K→E→D and psaD→C→A→B. It was suggested that the horizontal transfer of PSII and PSI genes is increasing phage fitness. To better understand their diversity, we designed degenerate primers to cover a wide diversity of organisms, and using PCR we targeted the psaC→A arrangement, which is unique to cyanophages cassettes. We examined viral concentrates from four islands in the Pacific Ocean and found samples containing the psaC→A arrangement. Analyses of the amplified viral psaA gene revealed six subgroups varying in their level of similarity and %G+C content, suggesting that the diversity of cyanophage PSI genes is greater than originally thought. PMID:25535938

  4. Viral load, gene expression and mapping of viral integration sites in HPV16-associated HNSCC cell lines.

    PubMed

    Olthof, Nadine C; Huebbers, Christian U; Kolligs, Jutta; Henfling, Mieke; Ramaekers, Frans C S; Cornet, Iris; van Lent-Albrechts, Josefa A; Stegmann, Alexander P A; Silling, Steffi; Wieland, Ulrike; Carey, Thomas E; Walline, Heather M; Gollin, Susanne M; Hoffmann, Thomas K; de Winter, Johan; Kremer, Bernd; Klussmann, Jens P; Speel, Ernst-Jan M

    2015-03-01

    HPV-related HNSCC generally have a better prognosis than HPV-negative HNSCC. However, a subgroup of HPV-positive tumors with poor prognosis has been recognized, particularly related to smoking, EGFR overexpression and chromosomal instability. Viral integration into the host genome might contribute to carcinogenesis, as is shown for cervical carcinomas. Therefore, all HPV16-positive HNSCC cell lines currently available have been carefully analyzed for viral and host genome parameters. The viral integration status, viral load, viral gene expression and the presence of aneusomies was evaluated in the cell lines UD-SCC-2, UM-SCC-047, UM-SCC-104, UPCI:SCC090, UPCI:SCC152, UPCI:SCC154 and 93VU147T. HPV integration was examined using FISH, APOT-PCR and DIPS-PCR. Viral load and the expression of the viral genes E2, E6 and E7 were determined via quantitative PCR. All cell lines showed integration-specific staining patterns and signals indicating transcriptional activity using FISH. APOT- and DIPS-PCR identified integration-derived fusion products in six cell lines and only episomal products for UM-SCC-104. Despite the observed differences in viral load and the number of viral integration sites, this did not relate to the identified viral oncogene expression. Furthermore, cell lines exhibited EGFR expression and aneusomy (except UPCI:SCC154). In conclusion, all HPV16-positive HNSCC cell lines showed integrated and/or episomal viral DNA that is transcriptionally active, although viral oncogene expression was independent of viral copy number and the number of viral integration sites. Because these cell lines also contain EGFR expression and aneusomy, which are parameters of poor prognosis, they should be considered suitable model systems for the development of new antiviral therapies. PMID:25082736

  5. A single injection of recombinant adeno-associated virus into the lumbar cistern delivers transgene expression throughout the whole spinal cord

    PubMed Central

    Guo, Yansu; Wang, Dan; Qiao, Tao; Yang, Chunxing; Su, Qin; Gao, Guangping; Xu, Zuoshang

    2015-01-01

    The lack of methods to deliver transgene expression in spinal cord has hampered investigation of gene function and therapeutic targets for spinal cord diseases. Here we report that a single intrathecal injection of recombinant adeno-associated virus rhesus-10 (rAAVrh10) into the lumbar cistern led to transgene expression in sixty to ninety percent of the cells in the spinal cord. The transgene was expressed in all cell types, including neurons, glia, ependymal cells and endothelial cells. Additionally, the transgene was expressed in some brain areas up to the frontal cortex and the olfactory bulb. The rAAV was distributed predominantly in the spinal cord, where its genome copy was over ten times that of the peripheral organs. Compared with intravenous injection, another method for rAAV delivery to the broad CNS, the intrathecal injection reduced the dosage of rAAV required to achieve similar or higher levels of transgene expression in the CNS by ∼100 fold. Finally, the transduced areas were colocalized with the perivascular spaces of Virchow-Robin, from which the rAAV spreads further into the CNS parenchyma, thus suggesting that rAAV penetrated the CNS parenchyma through this pathway. Taken together, we have defined a fast and efficient method to deliver widespread transgene expression in mature spinal cord in mice. This method can be applied to stably overexpress or silence gene expression in the spinal cord to investigate gene functions in mammalian CNS. Additionally, this method can be applied to validate therapeutic targets for spinal cord diseases. PMID:26050084

  6. Herpes Simplex Virus Type 1/Adeno-Associated Virus rep+ Hybrid Amplicon Vector Improves the Stability of Transgene Expression in Human Cells by Site-Specific Integration

    PubMed Central

    Wang, Y.; Camp, S. M.; Niwano, M.; Shen, X.; Bakowska, J. C.; Breakefield, X. O.; Allen, P. D.

    2002-01-01

    Herpes simplex virus type 1 (HSV-1) amplicon vectors are promising gene delivery tools, but their utility in gene therapy has been impeded to some extent by their inability to achieve stable transgene expression. In this study, we examined the possibility of improving transduction stability in cultured human cells via site-specific genomic integration mediated by adeno-associated virus (AAV) Rep and inverted terminal repeats (ITRs). A rep− HSV/AAV hybrid amplicon vector was made by inserting a transgene cassette flanked with AAV ITRs into an HSV-1 amplicon backbone, and a rep+ HSV/AAV hybrid amplicon was made by inserting rep68/78 outside the rep− vector 3′ AAV ITR sequence. Both vectors also had a pair of loxP sites flanking the ITRs. The resulting hybrid amplicon vectors were successfully packaged and compared to a standard amplicon vector for stable transduction frequency (STF) in human 293 and Gli36 cell lines and primary myoblasts. The rep+, but not the rep−, hybrid vector improved STF in all three types of cells; 84% of Gli36 and 40% of 293 stable clones transduced by the rep+ hybrid vector integrated the transgene into the AAVS1 site. Due to the difficulty in expanding primary myoblasts, we did not assess site-specific integration in these cells. A strategy to attempt further improvement of STF by “deconcatenating” the hybrid amplicon DNA via Cre-loxP recombination was tested, but it did not increase STF. These data demonstrate that introducing the integrating elements of AAV into HSV-1 amplicon vectors can significantly improve their ability to achieve stable gene transduction by conferring the AAV-like capability of site-specific genomic integration in dividing cells. PMID:12072515

  7. Adeno-Associated Virus Mediated Delivery of An Engineered Protein that Combines the Complement Inhibitory Properties of CD46, CD55 and CD59

    PubMed Central

    Leaderer, Derek; Cashman, Siobhan M.; Kumar-Singh, Rajendra

    2015-01-01

    Background A variety of disorders are associated with the activation of complement. CD46, CD55 and CD59 are the major membrane associated regulators of complement on human cells. Previously, we have found that independent expression of CD55, CD46 or CD59 through gene transfer protects murine tissues against human complement mediated attack. Herein we investigated the potential of combining the complement regulatory properties of CD46, CD55 and CD59 into single gene products expressed from an adeno-associated virus (AAV) vector in a soluble non-membrane anchored form. Methods Minigenes encoding the complement regulatory domains from CD46, CD55 and CD59 (SACT) or CD55 and CD59 (DTAC) were cloned into an AAV vector. The specific regulatory activity of each component of SACT and DTAC was measured in vitro. The recombinant AAV vectors were injected into the peritoneum of mice and the efficacy of the transgene products for being able to protect murine liver vasculature against human complement, specifically the membrane attack complex (MAC) was measured. Results SACT and DTAC exhibited properties similar to CD46, CD55 and CD59 or CD55 and CD59 respectively in vitro. AAV mediated delivery of SACT or DTAC protected murine liver vasculature from human MAC deposition by 63.2% and 56.7% respectively. Conclusions When delivered to mice in vivo via an AAV vector, SACT and DTAC are capable of limiting human complement mediated damage. SACT and DTAC merit further study as potential therapies for complement mediated disorders when delivered via a gene therapy approach. PMID:25917932

  8. Efficient retrograde transport of adeno-associated virus type 8 to spinal cord and dorsal root ganglion after vector delivery in muscle.

    PubMed

    Zheng, Hui; Qiao, Chunping; Wang, Chi-Hsien; Li, Juan; Li, Jianbin; Yuan, Zhenhua; Zhang, Cheng; Xiao, Xiao

    2010-01-01

    The peripheral nervous system (PNS), including peripheral nerves and dorsal root ganglion (DRG), is involved in numerous neurological disorders, such as peripheral neuropathies (diabetic neuropathy, chronic pain, etc.) and demyelination diseases (multiple sclerosis, congenital muscular dystrophy, Charcot-Marie-Tooth disease, etc.). Effective clinical interventions for those diseases are very limited. Gene therapy represents a novel therapeutic strategy for the PNS diseases, especially with simply and minimally invasive delivery methods. Previously, we have shown that adeno-associated virus type 8 (AAV8) can efficiently transduce muscles body wide by a simple intraperitoneal injection in neonatal mice. In this study, we investigated the capacity of AAV8 in transducing PNS in neonatal mice by intraperitoneal injection and also in adult mice by intramuscular injection. Efficient and long-term gene transfer was found in the white matter of the spinal cord, DRG neurons, and peripheral nerves in both groups, treated either as neonates or as adults, particularly neonates. In the adult mice injected with AAV8 in tibialis anterior and gastrocnemius muscles in one of the hind legs, more neurons were transduced in the lower part of the spinal cord than in the upper part; the DRG neurons were transduced more on the vector-injected side than in the contralateral uninjected side. Few cells in the gray matter of the spinal cord were transduced regardless of the delivery methods and age of the mice. These results support the mechanism of vector retrograde transport and suggest that AAV8 crosses blood-nerve barrier poorly. Our finding should have important implications in gene therapy for peripheral neurological disorders. PMID:19719401

  9. The Threefold Protrusions of Adeno-Associated Virus Type 8 Are Involved in Cell Surface Targeting as Well as Postattachment Processing

    PubMed Central

    Raupp, Christina; Naumer, Matthias; Müller, Oliver J.; Gurda, Brittney L.; Agbandje-McKenna, Mavis

    2012-01-01

    Adeno-associated virus (AAV) has attracted considerable interest as a vector for gene therapy owing its lack of pathogenicity and the wealth of available serotypes with distinct tissue tropisms. One of the most promising isolates for vector development, based on its superior gene transfer efficiency to the liver in small animals compared to AAV type 2 (AAV2), is AAV8. Comparison of the in vivo gene transduction of rAAV2 and rAAV8 in mice showed that single amino acid exchanges in the 3-fold protrusions of AAV8 in the surface loops comprised of residues 581 to 584 and 589 to 592 to the corresponding amino acids of AAV2 and vice versa had a strong influence on transduction efficiency and tissue tropism. Surprisingly, not only did conversion of AAV8 to AAV2 cap sequences increase the transduction efficiency and change tissue tropism but so did the reciprocal conversion of AAV2 to AAV8. Insertion of new peptide motifs at position 590 in AAV8 also enabled retargeting of AAV8 capsids to specific tissues, suggesting that these sequences can interact with receptors on the cell surface. However, a neutralizing monoclonal antibody that binds to amino acids 588QQNTA592 of AAV8 does not prevent cell binding and virus uptake, indicating that this region is not necessary for receptor binding but rather that the antibody interferes with an essential step of postattachment processing in which the 3-fold protrusion is also involved. This study supports a multifunctional role of the 3-fold region of AAV capsids in the infection process. PMID:22718833

  10. A Single Injection of Recombinant Adeno-Associated Virus into the Lumbar Cistern Delivers Transgene Expression Throughout the Whole Spinal Cord.

    PubMed

    Guo, Yansu; Wang, Dan; Qiao, Tao; Yang, Chunxing; Su, Qin; Gao, Guangping; Xu, Zuoshang

    2016-07-01

    The lack of methods to deliver transgene expression in spinal cord has hampered investigation of gene function and therapeutic targets for spinal cord diseases. Here, we report that a single intrathecal injection of recombinant adeno-associated virus rhesus-10 (rAAVrh10) into the lumbar cistern led to transgene expression in 60 to 90 % of the cells in the spinal cord. The transgene was expressed in all cell types, including neurons, glia, ependymal cells, and endothelial cells. Additionally, the transgene was expressed in some brain areas up to the frontal cortex and the olfactory bulb. The rAAV was distributed predominantly in the spinal cord, where its genome copy was over ten times that of the peripheral organs. Compared with intravenous injection, another method for rAAV delivery to the broad central nervous system (CNS), the intrathecal injection reduced the dosage of rAAV required to achieve similar or higher levels of transgene expression in the CNS by ~100-fold. Finally, the transduced areas were co-localized with the perivascular spaces of Virchow-Robin, from which the rAAV spreads further into the CNS parenchyma, thus suggesting that rAAV penetrated the CNS parenchyma through this pathway. Taken together, we have defined a fast and efficient method to deliver widespread transgene expression in mature spinal cord in mice. This method can be applied to stably overexpress or silence gene expression in the spinal cord to investigate gene functions in mammalian CNS. Additionally, this method can be applied to validate therapeutic targets for spinal cord diseases. PMID:26050084

  11. Improved osteogenic vector for non-viral gene therapy.

    PubMed

    Hacobian, A R; Posa-Markaryan, K; Sperger, S; Stainer, M; Hercher, D; Feichtinger, G A; Schuh, C M; Redl, H

    2016-01-01

    Therapeutic compensation of deficient bone regeneration is a challenging task and a topic of on-going search for novel treatment strategies. One promising approach for improvement involves non-viral gene delivery using the bone morphogenetic protein-2 (BMP-2) gene to provide transient, local and sustained expression of the growth factor. However, since efficiency of non-viral gene delivery is low, this study focused on the improvement of a BMP-2 gene expression system, aiming for compensation of poor transfection efficiency. First, the native BMP-2 gene sequence was modified by codon optimisation and altered by inserting a highly truncated artificial intron (96 bp). Transfection of multiple cell lines and rat adipose-derived mesenchymal stem cells with plasmids harbouring the improved BMP-2 sequence led to a several fold increased expression rate and subsequent osteogenic differentiation. Additionally, comparing expression kinetics of elongation factor 1 alpha (EF1α) promoter with a state of the art CMV promoter revealed significantly higher BMP-2 expression when under the influence of the EF1α promoter. Results obtained by quantification of bone markers as well as osteogenic assays showed reduced sensitivity to promoter silencing effects of the EF1α promoter in rat adipose-derived mesenchymal stem cells. Finally, screening of several protein secretion signals using either luciferase or BMP-2 as reporter protein revealed no superior candidates for potential replacement of the native BMP-2 secretion signal. Taken together, by enhancing the exogenous BMP-2 expression system, low transfection efficiencies in therapeutic applications can be compensated, making safe non-viral systems even more suitable for tissue regeneration approaches. PMID:26995192

  12. Adeno-Associated Virus Type 5 Utilizes Alternative Translation Initiation To Encode a Small Rep40-Like Protein▿

    PubMed Central

    Farris, K. David; Pintel, David J.

    2010-01-01

    Alternative splicing of adeno-associated virus type 2 (AAV2) P19-generated pre-mRNAs generates the small Rep proteins Rep52 and Rep40, which differ in their carboxyl termini. Both proteins are required for optimal packaging of AAV2 genomes. AAV5 Rep-encoding P19-generated transcripts are primarily polyadenylated within the central intron and not efficiently spliced; however, surprisingly, AAV5 was found to generate high levels of a Rep40-like protein. The AAV5 Rep40-like protein was generated by internal initiation and has the same C terminus as Rep52. Although precluded from using alternative splicing to generate multiple Rep isoforms, AAV5 ensures the production of a Rep40-like protein by utilizing a novel internal translation initiation event. PMID:19889770

  13. Productive life cycle of adeno-associated virus serotype 2 in the complete absence of a conventional polyadenylation signal.

    PubMed

    Wang, Lina; Yin, Zifei; Wang, Yuan; Lu, Yuan; Zhang, Daniel; Srivastava, Arun; Ling, Changquan; Aslanidi, George V; Ling, Chen

    2015-09-01

    We showed that WT adeno-associated virus serotype 2 (AAV2) genome devoid of a conventional polyadenylation [poly(A)] signal underwent complete genome replication, encapsidation and progeny virion production in the presence of adenovirus. The infectivity of the progeny virion was also retained. Using recombinant AAV2 vectors devoid of a human growth hormone poly(A) signal, we also demonstrated that a subset of mRNA transcripts contained the inverted terminal repeat (ITR) sequence at the 3' end, which we designated ITR in RNA (ITRR). Furthermore, AAV replication (Rep) proteins were able to interact with the ITRR. Taken together, our studies suggest a new function of the AAV2 ITR as an RNA element to mediate transgene expression from poly(A)-deleted mRNA. PMID:26297494

  14. Productive life cycle of adeno-associated virus serotype 2 in the complete absence of a conventional polyadenylation signal

    PubMed Central

    Wang, Lina; Yin, Zifei; Wang, Yuan; Lu, Yuan; Zhang, Daniel; Srivastava, Arun; Ling, Changquan

    2015-01-01

    We showed that WT adeno-associated virus serotype 2 (AAV2) genome devoid of a conventional polyadenylation [poly(A)] signal underwent complete genome replication, encapsidation and progeny virion production in the presence of adenovirus. The infectivity of the progeny virion was also retained. Using recombinant AAV2 vectors devoid of a human growth hormone poly(A) signal, we also demonstrated that a subset of mRNA transcripts contained the inverted terminal repeat (ITR) sequence at the 3′ end, which we designated ITR in RNA (ITRR). Furthermore, AAV replication (Rep) proteins were able to interact with the ITRR. Taken together, our studies suggest a new function of the AAV2 ITR as an RNA element to mediate transgene expression from poly(A)-deleted mRNA. PMID:26297494

  15. Integrin alphaVbeta5 is not involved in adeno-associated virus type 2 (AAV2) infection.

    PubMed

    Qiu, J; Brown, K E

    1999-11-25

    alphaVbeta5 integrin was recently proposed as a coreceptor for adeno-associated virus type 2 (AAV2) infection (Summerford et al., 1999, Nat. Med. 5, 78-82), based mainly on the direct binding of AAV2 to denatured beta5 by virus overlay assay. In studies using purified natural or recombinant human integrin alphaVbeta5 we were unable to demonstrate AAV2 binding, either by virus overlay or by liquid binding assay. Furthermore, neither purified integrin alphaVbeta5, nor RGD peptides, nor functional blocking monoclonal antibody blocked rAAV2 transduction. These data strongly suggest that integrin alphaVbeta5 is not involved in AAV2 infection. PMID:10562505

  16. Baculoviruses deficient in ie1 gene function abrogate viral gene expression in transduced mammalian cells

    SciTech Connect

    Efrose, Rodica; Swevers, Luc; Iatrou, Kostas

    2010-10-25

    One of the newest niches for baculoviruses-based technologies is their use as vectors for mammalian cell transduction and gene therapy applications. However, an outstanding safety issue related to such use is the residual expression of viral genes in infected mammalian cells. Here we show that infectious baculoviruses lacking the major transcriptional regulator, IE1, can be produced in insect host cells stably transformed with IE1 expression constructs lacking targets of homologous recombination that could promote the generation of wt-like revertants. Such ie1-deficient baculoviruses are unable to direct viral gene transcription to any appreciable degree and do not replicate in normal insect host cells. Most importantly, the residual viral gene expression, which occurs in mammalian cells infected with wt baculoviruses is reduced 10 to 100 fold in cells infected with ie1-deficient baculoviruses. Thus, ie1-deficient baculoviruses offer enhanced safety features to baculovirus-based vector systems destined for use in gene therapy applications.

  17. Enhancement of Recombinant Adeno-Associated Virus Type 2-Mediated Transgene Expression in a Lung Epithelial Cell Line by Inhibition of the Epidermal Growth Factor Receptor

    PubMed Central

    Smith, Andrew D.; Collaco, Roy F.; Trempe, James P.

    2003-01-01

    Recombinant adeno-associated viruses (rAAVs) have attracted considerable interest as gene delivery systems because they show long-term expression in vivo and transduce numerous cell types. Limitations to successful gene transduction from rAAVs have prompted investigations of a variety of treatments to enhance transgene expression from rAAV vectors. Tyrphostin-1, an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, dramatically enhances rAAV transgene expression. Elegant studies have demonstrated that a single-strand D-sequence-binding protein (ssDBP) is phosphorylated by EGFR and binds to the D sequence element in the AAV terminal repeat (TR). Binding of the Tyr-phosphorylated ssDBP prevents conversion of single-stranded vector DNA to a double-strand conformation. We observed dramatic increases in transgene expression in lung epithelial cells (IB3) with tyrphostin treatment. Gel shift analysis of ssDBP revealed that its DNA binding characteristics were unchanged after tyrphostin treatment or adenovirus infection. Tyrphostin stimulated rAAV transgene expression to a greater extent than adenovirus coinfection. Southern hybridizations revealed that the vector DNA remained in the single-strand conformation in tyrphostin-treated cells but double-stranded replicative form monomer DNA was most abundant in adenovirus-infected cells. Northern analyses revealed that tyrphostin treatment enhanced mRNA accumulation more than in adenovirus-infected cultures even though replicative form DNA was undetectable. Analysis of the JNK, ERK, and p38K mitogen-activated protein kinase pathways revealed that tyrphostin treatment stimulated the activity of JNK and p38K. Our data suggest that tyrphostin-induced alteration of stress response pathways results in dramatic enhancement of transcription on linear vector DNA templates in the IB3 cell line. These results expand the downstream targets of the EGFR in regulating rAAV transduction. PMID:12743297

  18. An siRNA Screen Identifies the U2 snRNP Spliceosome as a Host Restriction Factor for Recombinant Adeno-associated Viruses

    PubMed Central

    Schreiber, Claire A.; Sakuma, Toshie; Izumiya, Yoshihiro; Holditch, Sara J.; Hickey, Raymond D.; Bressin, Robert K.; Basu, Upamanyu; Koide, Kazunori; Asokan, Aravind; Ikeda, Yasuhiro

    2015-01-01

    Adeno-associated viruses (AAV) have evolved to exploit the dynamic reorganization of host cell machinery during co-infection by adenoviruses and other helper viruses. In the absence of helper viruses, host factors such as the proteasome and DNA damage response machinery have been shown to effectively inhibit AAV transduction by restricting processes ranging from nuclear entry to second-strand DNA synthesis. To identify host factors that might affect other key steps in AAV infection, we screened an siRNA library that revealed several candidate genes including the PHD finger-like domain protein 5A (PHF5A), a U2 snRNP-associated protein. Disruption of PHF5A expression selectively enhanced transgene expression from AAV by increasing transcript levels and appears to influence a step after second-strand synthesis in a serotype and cell type-independent manner. Genetic disruption of U2 snRNP and associated proteins, such as SF3B1 and U2AF1, also increased expression from AAV vector, suggesting the critical role of U2 snRNP spliceosome complex in this host-mediated restriction. Notably, adenoviral co-infection and U2 snRNP inhibition appeared to target a common pathway in increasing expression from AAV vectors. Moreover, pharmacological inhibition of U2 snRNP by meayamycin B, a potent SF3B1 inhibitor, substantially enhanced AAV vector transduction of clinically relevant cell types. Further analysis suggested that U2 snRNP proteins suppress AAV vector transgene expression through direct recognition of intact AAV capsids. In summary, we identify U2 snRNP and associated splicing factors, which are known to be affected during adenoviral infection, as novel host restriction factors that effectively limit AAV transgene expression. Concurrently, we postulate that pharmacological/genetic manipulation of components of the spliceosomal machinery might enable more effective gene transfer modalities with recombinant AAV vectors. PMID:26244496

  19. Adeno-Associated Virus Serotype 1 (AAV1)- and AAV5-Antibody Complex Structures Reveal Evolutionary Commonalities in Parvovirus Antigenic Reactivity

    PubMed Central

    Tseng, Yu-Shan; Gurda, Brittney L.; Chipman, Paul; McKenna, Robert; Afione, Sandra; Chiorini, John A.; Muzyczka, Nicholas; Olson, Norman H.; Baker, Timothy S.; Kleinschmidt, Jürgen

    2014-01-01

    ABSTRACT The clinical utility of the adeno-associated virus (AAV) gene delivery system has been validated by the regulatory approval of an AAV serotype 1 (AAV1) vector for the treatment of lipoprotein lipase deficiency. However, neutralization from preexisting antibodies is detrimental to AAV transduction efficiency. Hence, mapping of AAV antigenic sites and engineering of neutralization-escaping vectors are important for improving clinical efficacy. We report the structures of four AAV-monoclonal antibody fragment complexes, AAV1-ADK1a, AAV1-ADK1b, AAV5-ADK5a, and AAV5-ADK5b, determined by cryo-electron microscopy and image reconstruction to a resolution of ∼11 to 12 Å. Pseudoatomic modeling mapped the ADK1a epitope to the protrusions surrounding the icosahedral 3-fold axis and the ADK1b and ADK5a epitopes, which overlap, to the wall between depressions at the 2- and 5-fold axes (2/5-fold wall), and the ADK5b epitope spans both the 5-fold axis-facing wall of the 3-fold protrusion and portions of the 2/5-fold wall of the capsid. Combined with the six antigenic sites previously elucidated for different AAV serotypes through structural approaches, including AAV1 and AAV5, this study identified two common AAV epitopes: one on the 3-fold protrusions and one on the 2/5-fold wall. These epitopes coincide with regions with the highest sequence and structure diversity between AAV serotypes and correspond to regions determining receptor recognition and transduction phenotypes. Significantly, these locations overlap the two dominant epitopes reported for autonomous parvoviruses. Thus, rather than the amino acid sequence alone, the antigenic sites of parvoviruses appear to be dictated by structural features evolved to enable specific infectious functions. IMPORTANCE The adeno-associated viruses (AAVs) are promising vectors for in vivo therapeutic gene delivery, with more than 20 years of intense research now realized in a number of successful human clinical trials that

  20. Recombinant adeno-associated virus-mediated high-efficiency, transient expression of the murine cationic amino acid transporter (ecotropic retroviral receptor) permits stable transduction of human HeLa cells by ecotropic retroviral vectors.

    PubMed Central

    Bertran, J; Miller, J L; Yang, Y; Fenimore-Justman, A; Rueda, F; Vanin, E F; Nienhuis, A W

    1996-01-01

    Adeno-associated virus has a broad host range, is nonpathogenic, and integrates into a preferred location on chromosome 19, features that have fostered development of recombinant adeno-associated viruses (rAAV) as gene transfer vectors for therapeutic applications. We have used an rAAV to transfer and express the murine cationic amino acid transporter which functions as the ecotropic retroviral receptor, thereby rendering human cells conditionally susceptible to infection by an ecotropic retroviral vector. The proportion of human HeLa cells expressing the receptor at 60 h varied as a function of the multiplicity of infection (MOI) with the rAAV. Cells expressing the ecotropic receptor were efficiently transduced with an ecotropic retroviral vector encoding a nucleus-localized form of beta-galactosidase. Cells coexpressing the ecotropic receptor and nucleus-localized beta-galactosidase were isolated by fluorescence-activated cell sorting, and cell lines were recovered by cloning at limiting dilution. After growth in culture, all clones contained the retroviral vector genome, but fewer than 10% (3 of 47) contained the rAAV genome and continued to express the ecotropic receptor. The ecotropic receptor coding sequences in the rAAV genome were under the control of a tetracycline-modulated promoter. In the presence of tetracycline, receptor expression was low and the proportion of cells transduced by the ecotropic retroviral vector was decreased. Modulation of receptor expression was achieved with both an episomal and an integrated form of the rAAV genome. These data establish that functional gene expression from an rAAV genome can occur transiently without genome integration. PMID:8794313

  1. Infection of primary cells by adeno-associated virus type 2 results in a modulation of cell cycle-regulating proteins.

    PubMed Central

    Hermanns, J; Schulze, A; Jansen-Db1urr, P; Kleinschmidt, J A; Schmidt, R; zur Hausen, H

    1997-01-01

    It has been demonstrated that infection of primary human cells with adeno-associated viruses (AAV) leads to a decrease in cellular proliferation and to growth arrest. We analyzed the molecular basis of this phenomenon and observed that infection with AAV type 2 (AAV2) had an effect on several factors engaged in the control of the mammalian cell cycle. In particular, all of the pRB family members, pRB, p107, and p130, which are involved in G1 cell cycle checkpoint control, were affected. After infection, a shift from hyper- to hypophosphorylated forms was observed. Cyclins A and B1, which are required for G1/S transition and progression into mitosis, respectively, were downregulated at the transcriptional level as well as at the protein level, whereas the G1 cyclins D1 and E remained unaffected. In addition, the steady-state levels of cyclin-dependent kinases CDK1 and CDK2 and of transcription factor E2F-1 were diminished. Of all the factors known to be involved in phosphorylation of pRB family proteins, only the CDK inhibitor p21WAF1 exhibited a response to AAV2 infection. p21WAF1 mRNA was quickly and progressively upregulated in a p53-independent manner over at least 72 h. Consistent with the increased p21WAF1 protein levels, cyclin E- and cyclin A-dependent kinase activities declined to low levels and E2F-p130-cyclin-CDK2 complexes were disrupted. From these data, we conclude that the major effect of AAV2 infection on primary human fibroblasts appears to be upregulation of p21WAF1 gene expression and thus cell cycle arrest by the suppression of pRB family protein phosphorylation. PMID:9223493

  2. Deficiency in MyD88 Signaling Results in Decreased Antibody Responses to an Adeno-Associated Virus Vector in Murine Pompe Disease

    PubMed Central

    Zhang, Ping; Luo, Xiaoyan; Bird, Andrew; Li, Songtao

    2012-01-01

    Abstract We have previously shown that antibody and T cell responses limit the efficacy of an adeno-associated virus (AAV) pseudotype 8 (2/8) vector containing the universally active cytomegalovirus enhancer/chicken β-actin regulatory cassette (AAV2/8-CBhGAA) in treating murine Pompe disease. However, the innate immune responses to AAV2/8-CBhGAA are largely unknown. In this study, we investigated acute immune responses to AAV2/8-CBhGAA and the role of MyD88/TRIF signaling pathway in shaping adaptive immune responses to this vector. We showed here that a small and transient increase in CXCL-1 and IL-1β expression in livers of acid-α-glucosidase knockout (GAAKO) mice 6 h following injection with AAV2/8-CBhGAA. There was a robust antibody response to GAA in wild-type mice injected with this vector. In contrast, the anti-GAA IgG1 response was diminished in MyD88KO mice, and showed a trend toward a decrease in TRIFKO mice. In addition, the vector genome and GAA activity were significantly higher in MyD88KO livers compared with wild-type livers, suggesting reduced cytotoxic T cell responses. Importantly, elevated CD4+ T cells were detected by immunohistochemistry in MyD88KO livers. When adoptively transferred to wild-type mice, these CD4+ T cells have an ability to suppress antibody responses against AAV2/8-CBhGAA and to prevent further immunization against rhGAA. Our study suggests that the MyD88 deficiency leads to the suppression of deleterious immune responses to AAV2/8-CBhGAA, which has implications for gene therapy in Pompe disease. PMID:23514839

  3. Deficiency in MyD88 Signaling Results in Decreased Antibody Responses to an Adeno-Associated Virus Vector in Murine Pompe Disease.

    PubMed

    Zhang, Ping; Luo, Xiaoyan; Bird, Andrew; Li, Songtao; Koeberl, Dwight D

    2012-06-01

    We have previously shown that antibody and T cell responses limit the efficacy of an adeno-associated virus (AAV) pseudotype 8 (2/8) vector containing the universally active cytomegalovirus enhancer/chicken β-actin regulatory cassette (AAV2/8-CBhGAA) in treating murine Pompe disease. However, the innate immune responses to AAV2/8-CBhGAA are largely unknown. In this study, we investigated acute immune responses to AAV2/8-CBhGAA and the role of MyD88/TRIF signaling pathway in shaping adaptive immune responses to this vector. We showed here that a small and transient increase in CXCL-1 and IL-1β expression in livers of acid-α-glucosidase knockout (GAAKO) mice 6 h following injection with AAV2/8-CBhGAA. There was a robust antibody response to GAA in wild-type mice injected with this vector. In contrast, the anti-GAA IgG1 response was diminished in MyD88KO mice, and showed a trend toward a decrease in TRIFKO mice. In addition, the vector genome and GAA activity were significantly higher in MyD88KO livers compared with wild-type livers, suggesting reduced cytotoxic T cell responses. Importantly, elevated CD4(+) T cells were detected by immunohistochemistry in MyD88KO livers. When adoptively transferred to wild-type mice, these CD4(+) T cells have an ability to suppress antibody responses against AAV2/8-CBhGAA and to prevent further immunization against rhGAA. Our study suggests that the MyD88 deficiency leads to the suppression of deleterious immune responses to AAV2/8-CBhGAA, which has implications for gene therapy in Pompe disease. PMID:23514839

  4. Novel Caprine Adeno-Associated Virus (AAV) Capsid (AAV-Go.1) Is Closely Related to the Primate AAV-5 and Has Unique Tropism and Neutralization Properties

    PubMed Central

    Arbetman, Alejandra E.; Lochrie, Michael; Zhou, Shangzhen; Wellman, Jennifer; Scallan, Ciaran; Doroudchi, Mohammad M.; Randlev, Britta; Patarroyo-White, Susannah; Liu, Tongyao; Smith, Peter; Lehmkuhl, Howard; Hobbs, Lea Ann; Pierce, Glenn F.; Colosi, Peter

    2005-01-01

    Preexisting humoral immunity to adeno-associated virus (AAV) vectors may limit their clinical utility in gene delivery. We describe a novel caprine AAV (AAV-Go.1) capsid with unique biological properties. AAV-Go.1 capsid was cloned from goat-derived adenovirus preparations. Surprisingly, AAV-Go.1 capsid was 94% identical to the human AAV-5, with differences predicted to be largely on the surface and on or under the spike-like protrusions. In an in vitro neutralization assay using human immunoglobulin G (IgG) (intravenous immune globulin [IVIG]), AAV-Go.1 had higher resistance than AAV-5 (100-fold) and resistance similar to that of AAV-4 or AAV-8. In an in vivo model, SCID mice were pretreated with IVIG to generate normal human IgG plasma levels prior to the administration of AAV human factor IX vectors. Protein expression after intramuscular administration of AAV-Go.1 was unaffected in IVIG-pretreated mice, while it was reduced 5- and 10-fold after administration of AAV-1 and AAV-8, respectively. In contrast, protein expression after intravenous administration of AAV-Go.1 was reduced 7.1-fold, similar to the 3.8-fold reduction observed after AAV-8administration in IVIG-pretreated mice, and protein expression was essentially extinguished after AAV-2 administration in mice pretreated with much less IVIG (15-fold). AAV-Go.1 vectors also demonstrated a marked tropism for lung when administered intravenously in SCID mice. The pulmonary tropism and high neutralization resistance to human preexisting antibodies suggest novel therapeutic uses for AAV-Go.1 vectors, including targeting diseases such as cystic fibrosis. Nonprimate sources of AAVs may be useful to identify additional capsids with distinct tropisms and high resistance to neutralization by human preexisting antibodies. PMID:16306595

  5. Cell-Type-Specific Characteristics Modulate the Transduction Efficiency of Adeno-Associated Virus Type 2 and Restrain Infection of Endothelial Cells

    PubMed Central

    Pajusola, Katri; Gruchala, Marcin; Joch, Hana; Lüscher, Thomas F.; Ylä-Herttuala, Seppo; Büeler, Hansruedi

    2002-01-01

    Adeno-associated viruses (AAVs) are promising vectors for various gene therapy applications due to their long-lasting transgene expression and wide spectrum of target cells. Recently, however, it has become apparent that there are considerable differences in the efficiencies of transduction of different cell types by AAVs. Here, we analyzed the efficiencies of transduction and the transport mechanisms of AAV type 2 (AAV-2) in different cell types, emphasizing endothelial cells. Expression analyses in both cultured cells and the rabbit carotid artery assay showed a remarkably low level of endothelial cell transduction in comparison to the highly permissive cell types. The study of the endosomal pathways of AAV-2 with fluorescently labeled virus showed clear targeting of the Golgi area in permissive cell lines, but this phenomenon was absent in the endothelial cell line EAhy-926. On the other hand, the response to the block of endosomal acidification by bafilomycin A1 also showed differences among the permissive cell types. We also analyzed the effect of proteasome inhibitors on endothelial cells, but their impact on the primary cells and in vivo was not significant. On the contrary, analysis of the expression pattern of heparan sulfate proteoglycans (HSPGs), the primary receptors of AAV-2, revealed massive deposits of HSPG in the extracellular matrix of endothelial cells. The matrix-associated receptors may therefore compete for virus binding and reduce transduction in endothelial cells. Accordingly, in endothelial cells detached from their matrix, AAV-2 transduction was significantly increased. Altogether, these results point to a more complex cell-type-specific mode of transduction of AAV-2 than previously appreciated. PMID:12388714

  6. Cell-type-specific characteristics modulate the transduction efficiency of adeno-associated virus type 2 and restrain infection of endothelial cells.

    PubMed

    Pajusola, Katri; Gruchala, Marcin; Joch, Hana; Lüscher, Thomas F; Ylä-Herttuala, Seppo; Büeler, Hansruedi

    2002-11-01

    Adeno-associated viruses (AAVs) are promising vectors for various gene therapy applications due to their long-lasting transgene expression and wide spectrum of target cells. Recently, however, it has become apparent that there are considerable differences in the efficiencies of transduction of different cell types by AAVs. Here, we analyzed the efficiencies of transduction and the transport mechanisms of AAV type 2 (AAV-2) in different cell types, emphasizing endothelial cells. Expression analyses in both cultured cells and the rabbit carotid artery assay showed a remarkably low level of endothelial cell transduction in comparison to the highly permissive cell types. The study of the endosomal pathways of AAV-2 with fluorescently labeled virus showed clear targeting of the Golgi area in permissive cell lines, but this phenomenon was absent in the endothelial cell line EAhy-926. On the other hand, the response to the block of endosomal acidification by bafilomycin A1 also showed differences among the permissive cell types. We also analyzed the effect of proteasome inhibitors on endothelial cells, but their impact on the primary cells and in vivo was not significant. On the contrary, analysis of the expression pattern of heparan sulfate proteoglycans (HSPGs), the primary receptors of AAV-2, revealed massive deposits of HSPG in the extracellular matrix of endothelial cells. The matrix-associated receptors may therefore compete for virus binding and reduce transduction in endothelial cells. Accordingly, in endothelial cells detached from their matrix, AAV-2 transduction was significantly increased. Altogether, these results point to a more complex cell-type-specific mode of transduction of AAV-2 than previously appreciated. PMID:12388714

  7. A novel 165-base-pair terminal repeat sequence is the sole cis requirement for the adeno-associated virus life cycle.

    PubMed

    Xiao, X; Xiao, W; Li, J; Samulski, R J

    1997-02-01

    Adeno-associated virus (AAV) replication is dependent on two copies of a 145-bp inverted terminal repeat (ITR) that flank the AAV genome. This is the primary cis-acting element required for productive infection and the generation of recombinant AAV (rAAV) vectors. We have engineered a plasmid (pDD-2) containing only 165 bp of AAV sequence: two copies of the D element, a unique sequence adjacent to the AAV nicking site, flanking a single ITR. When assayed in vivo, this modified hairpin was sufficient for the replication of the plasmid vector when Rep and adenovirus (Ad) helper functions were supplied in trans. pDD-2 replication intermediates were characteristic of the AAV replication scheme in which linear monomer, dimer, and other higher-molecular-weight replicative intermediates are generated. Compared to infectious AAV clones for replication, the modified hairpin vector replicated more efficiently independent of size. Further analysis demonstrated conversion of the input circular plasmid to a linear substrate with AAV terminal repeat elements at either end as an initial step for replication. This conversion was independent of both Rep and Ad helper genes, suggesting the role of host factors in the production of these molecules. The generation of these substrates suggested resolution of the modified terminal repeat through a Holliday-like structure rather than replication as a mechanism for rescue. Production of replicative intermediates via this plasmid substrate were competent not only for AAV DNA replication but also for encapsidation, infection, integration, and subsequent rescue from the chromosome when superinfected with Ad and wild-type AAV. These studies demonstrate that this novel 165-bp ITR substrate is sufficient in cis for the AAV life cycle and should provide a valuable reagent for further dissecting the cis sequences involved in AAV replication, packaging, and integration. In addition, this novel plasmid vector can be used as a substrate for both r

  8. Gene Delivery of a Viral Anti-Inflammatory Protein to Combat Ocular Inflammation

    PubMed Central

    Ildefonso, Cristhian J.; Jaime, Henrique; Rahman, Masmudur M.; Li, Qiuhong; Boye, Shannon E.; Hauswirth, William W.; Lucas, Alexandra R.; McFadden, Grant

    2015-01-01

    Abstract Inflammation of the retina is a contributing factor in ocular diseases such as uveitis, diabetic retinopathy, and age-related macular degeneration (AMD). The M013 immunomodulatory protein from myxoma virus has been shown to interfere with the proinflammatory signaling pathways involving both the NLRP3 inflammasome and NF-κB. We have developed and characterized an adeno-associated viral (AAV) vector that delivers a secretable and cell-penetrating form of the M013 protein (TatM013). The expressed TatM013 protein was secreted and blocked the endotoxin-induced secretion of interleukin (IL)-1β in monocyte-derived cells and the reactive aldehyde-induced secretion of IL-1β in retinal pigment epithelium cells. The local anti-inflammatory effects of AAV-delivered TatM013 were evaluated in an endotoxin-induced uveitis (EIU) mouse model after intravitreal injection of mice with an AAV2-based vector carrying either TatM013 fused to a secreted green fluorescent protein (GFP) tag (sGFP-TatM013) or GFP. Expression of the sGFP-TatM013 transgene was demonstrated by fluorescence funduscopy in living mice. In EIU, the number of infiltrating cells and the concentration of IL-1β in the vitreous body were significantly lower in the eyes injected with AAV-sGFP-TatM013 compared with the eyes injected with control AAV-GFP. These results suggest that a virus-derived inhibitor of the innate immune response, when delivered via AAV, could be a generalized therapy for various inflammatory diseases of the eye. PMID:25420215

  9. Strategies for targeting primate neural circuits with viral vectors.

    PubMed

    El-Shamayleh, Yasmine; Ni, Amy M; Horwitz, Gregory D

    2016-07-01

    Understanding how the brain works requires understanding how different types of neurons contribute to circuit function and organism behavior. Progress on this front has been accelerated by optogenetics and chemogenetics, which provide an unprecedented level of control over distinct neuronal types in small animals. In primates, however, targeting specific types of neurons with these tools remains challenging. In this review, we discuss existing and emerging strategies for directing genetic manipulations to targeted neurons in the adult primate central nervous system. We review the literature on viral vectors for gene delivery to neurons, focusing on adeno-associated viral vectors and lentiviral vectors, their tropism for different cell types, and prospects for new variants with improved efficacy and selectivity. We discuss two projection targeting approaches for probing neural circuits: anterograde projection targeting and retrograde transport of viral vectors. We conclude with an analysis of cell type-specific promoters and other nucleotide sequences that can be used in viral vectors to target neuronal types at the transcriptional level. PMID:27052579

  10. Control of adenovirus early gene expression: Posttranscriptional control mediated by both viral and cellular gene products

    SciTech Connect

    Katze, M.G.; Persson, H.; Philipson, L.

    1981-09-01

    An adenovirus type 5 host range mutant (hr-1) located in region E1A and phenotypically defective in expressing viral messenger ribonucleic acid (RNA) from other early regions was analyzed for accumulation of viral RNA in the presence of protein synthesis inhibitors. Nuclear RNA was transcribed from all early regions at the same rate, regardless of whether the drug was present or absent. As expected, low or undetectable levels of RNA were found in the cytoplasm of hr-1-infected cells compared with the wild-type adenovirus type 5 in the absence of drug. When anisomycin was added 30 min before hr-1 infection, cytoplasmic RNA was abundant from early regions E3 and E4 when assayed by filter hybridization. In accordance, early regions E3 and E4 viral messenger RNA species were detected by the S1 endonuclease mapping technique only in hr-1-infected cells that were treated with the drug. Similar results were obtained by in vitro translation studies. Together, these results suggest that this adenovirus type 5 mutant lacks a viral gene product necessary for accumulation of viral messenger RNA, but not for transcription. It is proposed that a cellular gene product serves as a negative regulator of viral messenger RNA accumulation at the posttranscriptional level.

  11. Clinical Applications Involving CNS Gene Transfer

    PubMed Central

    Kantor, Boris; McCown, Thomas; Leone, Paola; Gray, Steven J.

    2015-01-01

    Diseases of the central nervous system (CNS) have traditionally been the most difficult to treat by traditional pharmacological methods, due mostly to the blood–brain barrier and the difficulties associated with repeated drug administration targeting the CNS. Viral vector gene transfer represents a way to permanently provide a therapeutic protein within the nervous system after a single administration, whether this be a gene replacement strategy for an inherited disorder or a disease-modifying protein for a disease such as Parkinson's. Gene therapy approaches for CNS disorders has evolved considerably over the last two decades. Although a breakthrough treatment has remained elusive, current strategies are now considerably safer and potentially much more effective. This chapter will explore the past, current, and future status of CNS gene therapy, focusing on clinical trials utilizing adeno-associated virus and lentiviral vectors. PMID:25311921

  12. Gene therapy for CNS diseases - Krabbe disease.

    PubMed

    Rafi, Mohammad A

    2016-01-01

    This is a brief report of the 19th Annual Meeting of the American Society of Gene and Cell Therapy that took place from May 4th through May 7th, 2016 in Washington, DC, USA. While the meeting provided many symposiums, lectures, and scientific sessions this report mainly focuses on one of the sessions on the "Gene Therapy for central nervous system (CNS) Diseases" and specifically on the "Gene Therapy for the globoid cell leukodystrophy or Krabbe disease. Two presentations focused on this subject utilizing two animal models of this disease: mice and dog models. Different serotypes of adeno-associate viral vectors (AAV) alone or in combination with bone marrow transplantations were used in these research projects. The Meeting of the ASGCT reflected continuous growth in the fields of gene and cell therapy and brighter forecast for efficient treatment options for variety of human diseases. PMID:27525222

  13. Gene expression in primate liver during viral hemorrhagic fever

    PubMed Central

    Djavani, Mahmoud; Crasta, Oswald R; Zhang, Yan; Zapata, Juan Carlos; Sobral, Bruno; Lechner, Melissa G; Bryant, Joseph; Davis, Harry; Salvato, Maria S

    2009-01-01

    Background Rhesus macaques infected with lymphocytic choriomeningitis virus (LCMV) provide a model for human Lassa fever. Disease begins with flu-like symptoms and progresses rapidly with fatal consequences. Previously, we profiled the blood transcriptome of LCMV-infected monkeys (M. Djavani et al J. Virol. 2007) showing distinct pre-viremic and viremic stages that discriminated virulent from benign infections. In the present study, changes in liver gene expression from macaques infected with virulent LCMV-WE were compared to gene expression in uninfected monkeys as well as to monkeys that were infected but not diseased. Results Based on a functional pathway analysis of differentially expressed genes, virulent LCMV-WE had a broader effect on liver cell function than did infection with non-virulent LCMV-Armstrong. During the first few days after infection, LCMV altered expression of genes associated with energy production, including fatty acid and glucose metabolism. The transcriptome profile resembled that of an organism in starvation: mRNA for acetyl-CoA carboxylase, a key enzyme of fatty acid synthesis was reduced while genes for enzymes in gluconeogenesis were up-regulated. Expression was also altered for genes associated with complement and coagulation cascades, and with signaling pathways involving STAT1 and TGF-β. Conclusion Most of the 4500 differentially expressed transcripts represented a general response to both virulent and mild infections. However, approximately 250 of these transcripts had significantly different expression in virulent infections as compared to mild infections, with approximately 30 of these being differentially regulated during the pre-viremic stage of infection. The genes that are expressed early and differently in mild and virulent disease are potential biomarkers for prognosis and triage of acute viral disease. PMID:19216742

  14. Effective gene therapy in an authentic model of Tay-Sachs-related diseases.

    PubMed

    Cachón-González, M Begoña; Wang, Susan Z; Lynch, Andrew; Ziegler, Robin; Cheng, Seng H; Cox, Timothy M

    2006-07-01

    Tay-Sachs disease is a prototypic neurodegenerative disease. Lysosomal storage of GM2 ganglioside in Tay-Sachs and the related disorder, Sandhoff disease, is caused by deficiency of beta-hexosaminidase A, a heterodimeric protein. Tay-Sachs-related diseases (GM2 gangliosidoses) are incurable, but gene therapy has the potential for widespread correction of the underlying lysosomal defect by means of the secretion-recapture cellular pathway for enzymatic complementation. Sandhoff mice, lacking the beta-subunit of hexosaminidase, manifest many signs of classical human Tay-Sachs disease and, with an acute course, die before 20 weeks of age. We treated Sandhoff mice by stereotaxic intracranial inoculation of recombinant adeno-associated viral vectors encoding the complementing human beta-hexosaminidase alpha and beta subunit genes and elements, including an HIV tat sequence, to enhance protein expression and distribution. Animals survived for >1 year with sustained, widespread, and abundant enzyme delivery in the nervous system. Onset of the disease was delayed with preservation of motor function; inflammation and GM2 ganglioside storage in the brain and spinal cord was reduced. Gene delivery of beta-hexosaminidase A by using adeno-associated viral vectors has realistic potential for treating the human Tay-Sachs-related diseases. PMID:16801539

  15. Hydrostatic Isolated Limb Perfusion with Adeno-associated Virus Vectors Enhances Correction of Skeletal Muscle in Pompe Disease

    PubMed Central

    Sun, Baodong; Li, Songtao; Bird, Andrew; Koeberl, Dwight D.

    2010-01-01

    Glycogen storage disease type II (GSD-II; Pompe disease; MIM 232300) stems from the inherited deficiency of acid-α-glucosidase (GAA; acid maltase; EC 3.2.1.20), which primarily involves cardiac and skeletal muscles. We hypothesized that hydrostatic isolated limb perfusion (ILP) administration of an adeno-associated virus (AAV) vector containing a muscle specific promoter could achieve relatively higher transgene expression in the hindlimb muscles of GAA-knockout (GAA-KO) mice, in comparison with intravenous (IV) administration. ILP adminstration of AAV2/8 vectors encoding alkaline phosphatase or human GAA transduced skeletal muscles of the hindlimb widely, despite the relatively low number of vector particles administered (1×1011), and IV administration of an equivalent vector dose failed to transduce skeletal muscle detectably. Similarly, ILP administration of fewer vector particles of the AAV2/9 vector encoding human GAA (3×1010) transduced skeletal muscles of the hindlimb widely and significantly reduced glycogen content to, in comparison with IV administration. The only advantage for IV administration was moderately high level transduction of cardiac muscle, which demonstrated compellingly that ILP administration sequestered vector particles within the perfused limb. Reduction of glycogen storage in the extensor digitorum longus demonstrated the potential advantage of ILP-mediated delivery of AAV vectors in Pompe disease, because type II myofibers are resistant to enzyme replacement therapy. Thus, ILP will enhance AAV transduction of multiple skeletal muscles while reducing the required dosages in terms of vector particle numbers. PMID:20686508

  16. Rep-mediated nicking of the adeno-associated virus origin requires two biochemical activities, DNA helicase activity and transesterification.

    PubMed

    Brister, J R; Muzyczka, N

    1999-11-01

    The single-stranded adeno-associated virus (AAV) genome is flanked by terminal hairpinned origins of DNA replication (terminal repeats [TRs]) that are nicked at the terminal resolution site (trs) by the AAV Rep protein in an ATP-dependent, site-specific manner. Here we determine the minimal trs sequence necessary for Rep cleavage, 3'-CCGGT/TG-5', and show that this 7-base core sequence is required only on the nicked strand. We also identify a potential stem-loop structure at the trs. Interestingly, Rep nicking on a TR substrate that fixes this trs stem-loop in the extruded form no longer requires ATP. This suggests that ATP-dependent Rep helicase activity is necessary to unwind the duplex trs and extrude the stem-loop structure, prior to the ATP-independent Rep transesterification reaction. The extrusion of origin stem-loop structures prior to nicking appears to be a general mechanism shared by plant and animal viruses and bacterial plasmids. In the case of AAV, this mechanism of TR nicking would provide a possible regulatory function. PMID:10516041

  17. Impact of Preexisting Vector Immunity on the Efficacy of Adeno-Associated Virus-Based HIV-1 Gag Vaccines

    PubMed Central

    Lin, Jianping; Calcedo, Roberto; Vandenberghe, Luk H.; Figueredo, Joanita M.

    2008-01-01

    Abstract Vectors based on primate-derived adeno-associated virus (AAV) are being considered in the development of genetic vaccines against a number of diseases including infection with HIV-1. Preexisting immunity to the vaccine carrier as a result of natural infections could potentially compromise vaccine efficacy. This study evaluates the impact of neutralizing antibodies against AAV capsids on the ability of HIV-1 Gag-expressing vectors to elicit transgene-specific T and B cell responses. Mice were passively transferred with pooled human immunoglobulin at various doses to simulate human antivector humoral immunity. Vectors based on serotype 2, which were evaluated in the clinic, were compared with those created from the novel monkey isolates AAV7 and AAV8. Inhibition of AAV2-directed Gag responses occurred at doses of human immunoglobulin 10- to 20-fold less than was required to inhibit immunogenicity of AAV7 and AAV8 vectors. Cynomolgus macaques were screened for preexisting immunity to AAV7 and AAV8 and sera from individual animals were passively transferred into mice that were analyzed for AAV vaccine efficacy. There was a correlation between the level of preexisting capsid neutralizing titers and diminution of vaccine efficacy; sera from a number of animals with no detectable neutralizing antibodies showed partial vaccine inhibition, suggesting that the in vitro assay is less sensitive than the in vivo passive transfer assay for detecting neutralizing antibodies to AAV. PMID:18549307

  18. Recombinant adeno-associated virus type 2 replication and packaging is entirely supported by a herpes simplex virus type 1 amplicon expressing Rep and Cap.

    PubMed Central

    Conway, J E; Zolotukhin, S; Muzyczka, N; Hayward, G S; Byrne, B J

    1997-01-01

    Recombinant adeno-associated virus (AAV) type 2 (rAAV) vectors have recently been shown to have great utility as gene transfer agents both in vitro and in vivo. One of the problems associated with the use of rAAV vectors has been the difficulty of large-scale vector production. Low-efficiency plasmid transfection of the rAAV vector and complementing AAV type 2 (AAV-2) functions (rep and cap) followed by superinfection with adenovirus has been the standard approach to rAAV production. The objectives of this study were to demonstrate the ability of a recombinant herpes simplex virus type 1 (HSV-1) amplicon expressing AAV-2 Rep and Cap to support replication and packaging of rAAV vectors. HSV-1 amplicon vectors were constructed which contain the AAV-2 rep and cap genes under control of their native promoters (p5, p19, and p40). An HSV-1 amplicon vector, HSV-RC/KOS or HSV-RC/d27, was generated by supplying helper functions with either wild-type HSV-1 (KOS strain) or the ICP27-deleted mutant of HSV-1, d27-1, respectively. Replication of the amplicon stocks is not inhibited by the presence of AAV-2 Rep proteins, which highlights important differences between HSV-1 and adenovirus replication and the mechanism of providing helper function for productive AAV infection. Coinfection of rAAV and HSV-RC/KOS resulted in the replication and amplification of rAAV genomes. Similarly, rescue and replication of rAAV genomes occurred when rAAV vector plasmids were transfected into cells followed by HSV-RC/KOS infection and when two rAAV proviral cell lines were infected with HSV-RC/KOS or HSV-RC/d27. Production of infectious rAAV by rescue from two rAAV proviral cell lines has also been achieved with HSV-RC/KOS and HSV-RC/d27. The particle titer of rAAV produced with HSV-RC/d27 is equal to that achieved by supplying rep and cap by transfection followed by adenovirus superinfection. Importantly, no detectable wild-type AAV-2 is generated with this approach. These results demonstrate

  19. A Genetic Approach to Promoter Recognition during Trans Induction of Viral Gene Expression

    NASA Astrophysics Data System (ADS)

    Coen, Donald M.; Weinheimer, Steven P.; McKnight, Steven L.

    1986-10-01

    Viral infection of mammalian cells entails the regulated induction of viral gene expression. The induction of many viral genes, including the herpes simplex virus gene encoding thymidine kinase (tk), depends on viral regulatory proteins that act in trans. Because recognition of the tk promoter by cellular transcription factors is well understood, its trans induction by viral regulatory proteins may serve as a useful model for the regulation of eukaryotic gene expression. A comprehensive set of mutations was therefore introduced into the chromosome of herpes simplex virus at the tk promoter to directly analyze the effects of promoter mutations on tk transcription. The promoter domains required for efficient tk expression under conditions of trans induction corresponded to those important for recognition by cellular transcription factors. Thus, trans induction of tk expression may be catalyzed initially by the interaction of viral regulatory proteins with cellular transcription factors.

  20. AAV Vectors for Cardiac Gene Transfer: Experimental Tools and Clinical Opportunities

    PubMed Central

    Pacak, Christina A; Byrne, Barry J

    2011-01-01

    Since the first demonstration of in vivo gene transfer into myocardium there have been a series of advancements that have driven the evolution of cardiac gene delivery from an experimental tool into a therapy currently at the threshold of becoming a viable clinical option. Innovative methods have been established to address practical challenges related to tissue-type specificity, choice of delivery vehicle, potency of the delivered material, and delivery route. Most importantly for therapeutic purposes, these strategies are being thoroughly tested to ensure safety of the delivery system and the delivered genetic material. This review focuses on the development of recombinant adeno-associated virus (rAAV) as one of the most valuable cardiac gene transfer agents available today. Various forms of rAAV have been used to deliver “pre-event” cardiac protection and to temper the severity of hypertrophy, cardiac ischemia, or infarct size. Adeno-associated virus (AAV) vectors have also been functional delivery tools for cardiac gene expression knockdown studies and successfully improving the cardiac aspects of several metabolic and neuromuscular diseases. Viral capsid manipulations along with the development of tissue-specific and regulated promoters have greatly increased the utility of rAAV-mediated gene transfer. Important clinical studies are currently underway to evaluate AAV-based cardiac gene delivery in humans. PMID:21792180

  1. Gene expression regulation in retinal pigment epithelial cells induced by viral RNA and viral/bacterial DNA

    PubMed Central

    Brosig, Anton; Kuhrt, Heidrun; Wiedemann, Peter; Kohen, Leon; Bringmann, Andreas

    2015-01-01

    Purpose The pathogenesis of age-related macular degeneration (AMD) is associated with systemic and local inflammation. Various studies suggested that viral or bacterial infection may aggravate retinal inflammation in the aged retina. We compared the effects of synthetic viral RNA (poly(I:C)) and viral/bacterial DNA (CpG-ODN) on the expression of genes known to be involved in the development of AMD in retinal pigment epithelial (RPE) cells. Methods Cultured human RPE cells were stimulated with poly(I:C; 500 µg/ml) or CpG-ODN (500 nM). Alterations in gene expression and protein secretion were determined with real-time RT–PCR and ELISA, respectively. Phosphorylation of signal transduction molecules was revealed by western blotting. Results Poly(I:C) induced gene expression of the pattern recognition receptor TLR3, transcription factors (HIF-1α, p65/NF-κB), the angiogenic factor bFGF, inflammatory factors (IL-1β, IL-6, TNFα, MCP-1, MIP-2), and complement factors (C5, C9, CFB). Poly(I:C) also induced phosphorylation of ERK1/2 and p38 MAPK proteins, and the secretion of bFGF and TNFα from the cells. CpG-ODN induced moderate gene expression of transcription factors (p65/NF-κB, NFAT5) and complement factors (C5, C9), while it had no effect on the expression of various TLR, angiogenic factor, and inflammatory factor genes. The activities of various signal transduction pathways and transcription factors were differentially involved in mediating the poly(I:C)-induced transcriptional activation of distinct genes. Conclusions The widespread effects of viral RNA, and the restricted effects of viral/bacterial DNA, on the gene expression pattern of RPE cells may suggest that viral RNA rather than viral/bacterial DNA induces physiologic alterations of RPE cells, which may aggravate inflammation in the aged retina. The data also suggest that selective inhibition of distinct signal transduction pathways or individual transcription factors may not be effective to inhibit

  2. Three Year Follow-Up after Unilateral Subretinal Delivery of Adeno-Associated Virus in Patients with Leber Congenital Amaurosis Type 2

    PubMed Central

    Testa, Francesco; Maguire, Albert M; Rossi, Settimio; Pierce, Eric A; Melillo, Paolo; Marshall, Kathleen; Banfi, Sandro; Surace, Enrico M.; Sun, Junwei; Acerra, Carmela; Wright, J. Fraser; Wellman, Jennifer; High, Katherine A; Auricchio, Alberto; Bennett, Jean; Simonelli, Francesca

    2012-01-01

    Objective The aim of the current study is to show the clinical data of long-term (3 year) follow-up of five patients affected by Leber Congenital Amaurosis type 2 (LCA2) treated with a single unilateral injection of AAV2-hRPE65v2. Design clinical trial Participants five LCA2 patients with RPE65 gene mutations Methods After informed consent and confirmation of trial eligibility criteria, the eye with worse visual function was selected for subretinal delivery of Adeno-Associated Virus (AAV2-hRPE65v2). Subjects were evaluated before and after surgery at designated follow-up visits (1, 2, 3, 14, 30, 60, 90, 180, 270, 365 days, 1.5 years and 3 years) by complete ophthalmic examination. Efficacy for each subject was monitored with best corrected visual acuity, kinetic visual field, nystagmus testing and pupillary light reflex. Main Outcome Measures best corrected visual acuity, kinetic visual field, nystagmus testing and pupillary light reflex. Results The data showed a statistically significant improvement of best corrected visual acuity between baseline and 3 years after treatment in the treated eye (p<0.001). In all patients we observed an enlargement of the areas of visual field, which remained stable till 3 years post injection (average values: baseline 1058 deg2 vs 3 years post treatment: 4630 deg2) and a reduction of the nystagmus frequency compared to baseline at the 3 year time-point. Furthermore, a statistically significant difference was observed in the pupillary constriction of the treated eye (p<0.05) compared to the untreated eye in three patients at 1 and 3-year time-points. No patients suffered serious adverse events related to the vector in the 3 year post-injection period. Conclusions The long-term follow-up data (3 years) on the 5-patient Italian cohort involved in the LCA2 gene therapy clinical trial clearly showed a stability of improvement in visual and retinal function that had been achieved a few months after treatment. Longitudinal data analysis

  3. Retinal transduction profiles by high-capacity viral vectors

    PubMed Central

    Puppo, Agostina; Cesi, Giulia; Marrocco, Elena; Piccolo, Pasquale; Jacca, Sarah; Shayakhmetov, Dmitry M.; Parks, Robin J.; Davidson, Beverly L.; Colloca, Stefano; Brunetti-Pierri, Nicola; Ng, Philip; Donofrio, Gaetano; Auricchio, Alberto

    2014-01-01

    Retinal gene therapy with adeno-associated viral (AAV) vectors is safe and effective in humans. However, the limited cargo capacity of AAV prevents their use for therapy of those inherited retinopathies (IRs) due to mutations in large (>5kb) genes. Viral vectors derived from Adenovirus (Ad), Lentivirus (LV) and Herpesvirus (HV) can package large DNA sequences but do not target efficiently retinal photoreceptors (PRs) where the majority of genes responsible for IRs are expressed. Here, we have evaluated the mouse retinal transduction profiles of vectors derived from 16 different Ad serotypes, 7 LV pseudotypes, and from a bovine HV. Most of the vectors tested transduced efficiently the retinal pigment epithelium (RPE). We found that LV-GP64 tends to transduce more PRs than the canonical LV-VSVG albeit this was restricted to a narrow region. We observed more extensive PR transduction with HdAd1, 2 and 5/F35++ than with LV, although none of them outperformed the canonical HdAd5 or matched the extension of PR transduction achieved with AAV2/8. PMID:24989814

  4. Applying horizontal gene transfer phenomena to enhance non-viral gene therapy

    PubMed Central

    Elmer, Jacob J.; Christensen, Matthew D.; Rege, Kaushal

    2014-01-01

    Horizontal gene transfer (HGT) is widespread amongst prokaryotes, but eukaryotes tend to be far less promiscuous with their genetic information. However, several examples of HGT from pathogens into eukaryotic cells have been discovered and mimicked to improve non-viral gene delivery techniques. For example, several viral proteins and DNA sequences have been used to significantly increase cytoplasmic and nuclear gene delivery. Plant genetic engineering is routinely performed with the pathogenic bacterium Agrobacterium tumefaciens and similar pathogens (e.g. Bartonella henselae) may also be able to transform human cells. Intracellular parasites like Trypanosoma cruzi may also provide new insights into overcoming cellular barriers to gene delivery. Finally, intercellular nucleic acid transfer between host cells will also be briefly discussed. This article will review the unique characteristics of several different viruses and microbes and discuss how their traits have been successfully applied to improve non-viral gene delivery techniques. Consequently, pathogenic traits that originally caused diseases may eventually be used to treat many genetic diseases. PMID:23994344

  5. Evolving lessons on nanomaterial-coated viral vectors for local and systemic gene therapy.

    PubMed

    Kasala, Dayananda; Yoon, A-Rum; Hong, Jinwoo; Kim, Sung Wan; Yun, Chae-Ok

    2016-07-01

    Viral vectors are promising gene carriers for cancer therapy. However, virus-mediated gene therapies have demonstrated insufficient therapeutic efficacy in clinical trials due to rapid dissemination to nontarget tissues and to the immunogenicity of viral vectors, resulting in poor retention at the disease locus and induction of adverse inflammatory responses in patients. Further, the limited tropism of viral vectors prevents efficient gene delivery to target tissues. In this regard, modification of the viral surface with nanomaterials is a promising strategy to augment vector accumulation at the target tissue, circumvent the host immune response, and avoid nonspecific interactions with the reticuloendothelial system or serum complement. In the present review, we discuss various chemical modification strategies to enhance the therapeutic efficacy of viral vectors delivered either locally or systemically. We conclude by highlighting the salient features of various nanomaterial-coated viral vectors and their prospects and directions for future research. PMID:27348247

  6. Persistence, localization, and external control of transgene expression after single injection of adeno-associated virus into injured joints.

    PubMed

    Lee, Hannah H; O'Malley, Michael J; Friel, Nicole A; Payne, Karin A; Qiao, Chunping; Xiao, Xiao; Chu, Constance R

    2013-04-01

    A single intra-articular injection of adeno-associated virus (AAV) results in stable and controllable transgene expression in normal rat knees. Because undamaged joints are unlikely to require treatment, the study of AAV delivery in joint injury models is crucial to potential therapeutic applications. This study tests the hypotheses that persistent and controllable AAV-transgene expression are (1) highly localized to the cartilage when AAV is injected postinjury and (2) localized to the intra-articular soft tissues when AAV is injected preinjury. Two AAV injection time points, postinjury and preinjury, were investigated in osteochondral defect and anterior cruciate ligament transection models of joint injury. Rats injected with AAV tetracycline response element (TRE)-luciferase received oral doxycycline for 7 days. Luciferase expression was evaluated longitudinally for 6 months. Transgene expression was persistent and controllable with oral doxycycline for 6 months in all groups. However, the location of transgene expression was different: postinjury AAV-injected knees had luciferase expression highly localized to the cartilage, while preinjury AAV-injected knees had more widespread signal from intra-articular soft tissues. The differential transgene localization between preinjury and postinjury injection can be used to optimize treatment strategies. Highly localized postinjury injection appears advantageous for treatments targeting repair cells. The more generalized and controllable reservoir of transgene expression following AAV injection before anterior cruciate ligament transection (ACLT) suggests an intriguing concept for prophylactic delivery of joint protective factors to individuals at high risk for early osteoarthritis (OA). Successful external control of intra-articular transgene expression provides an added margin of safety for these potential clinical applications. PMID:23496155

  7. A new genetic vaccine platform based on an adeno-associated virus isolated from a rhesus macaque.

    PubMed

    Lin, Jianping; Calcedo, Roberto; Vandenberghe, Luk H; Bell, Peter; Somanathan, Suryanarayan; Wilson, James M

    2009-12-01

    We created a hybrid adeno-associated virus (AAV) from two related rhesus macaque isolates, called AAVrh32.33, and evaluated it as a vaccine carrier for human immunodeficiency virus type 1 (HIV-1) and type A influenza virus antigens. The goal was to overcome the limitations of vaccines based on other AAVs, which generate dysfunctional T-cell responses and are inhibited by antibodies found in human sera. Injection of a Gag-expressing AAVrh32.33 vector into mice resulted in a high-quality CD8(+) T-cell response. The resulting Gag-specific T cells express multiple cytokines at high levels, including interleukin-2, with many having memory phenotypes; a subsequent boost with an adenovirus vector yielded a brisk expansion of Gag-specific T cells. A priming dose of AAVrh32.33 led to high levels of Gag antibodies, which exceed levels found after injection of adenovirus vectors. Importantly, passive transfer of pooled human immunoglobulin into mice does not interfere with the efficacy of AAVrh32.33 expressing nucleoproteins from influenza virus, as measured by protection to a lethal dose of influenza virus, which is consistent with the very low seroprevalence to this virus in humans. Studies of macaques with vectors expressing gp140 from HIV-1 (i.e., with AAVrh32.33 as the prime and simian adenovirus type 24 as the boost) demonstrated results similar to those for mice with high-level and high-quality CD8(+) T-cell responses to gp140 and high-titered neutralizing antibodies to homologous HIV-1. The biology of this novel AAV hybrid suggests that it should be a preferred genetic vaccine carrier, capable of generating robust T- and B-cell responses. PMID:19812149

  8. Hepatorenal correction in murine glycogen storage disease type I with a double-stranded adeno-associated virus vector.

    PubMed

    Luo, Xiaoyan; Hall, Gentzon; Li, Songtao; Bird, Andrew; Lavin, Peter J; Winn, Michelle P; Kemper, Alex R; Brown, Talmage T; Koeberl, Dwight D

    2011-11-01

    Glycogen storage disease type Ia (GSD-Ia) is caused by the deficiency of glucose-6-phosphatase (G6Pase). Long-term complications of GSD-Ia include life-threatening hypoglycemia and proteinuria progressing to renal failure. A double-stranded (ds) adeno-associated virus serotype 2 (AAV2) vector encoding human G6Pase was pseudotyped with four serotypes, AAV2, AAV7, AAV8, and AAV9, and we evaluated efficacy in 12-day-old G6pase (-/-) mice. Hypoglycemia during fasting (plasma glucose <100 mg/dl) was prevented for >6 months by the dsAAV2/7, dsAAV2/8, and dsAAV2/9 vectors. Prolonged fasting for 8 hours revealed normalization of blood glucose following dsAAV2/9 vector administration at the higher dose. The glycogen content of kidney was reduced by >65% with both the dsAAV2/7 and dsAAV2/9 vectors, and renal glycogen content was stably reduced between 7 and 12 months of age for the dsAAV2/9 vector-treated mice. Every vector-treated group had significantly reduced glycogen content in the liver, in comparison with untreated G6pase (-/-) mice. G6Pase was expressed in many renal epithelial cells of with the dsAAV2/9 vector for up to 12 months. Albuminuria and renal fibrosis were reduced by the dsAAV2/9 vector. Hepatorenal correction in G6pase (-/-) mice demonstrates the potential of AAV vectors for the correction of inherited diseases of metabolism. PMID:21730973

  9. Hepatorenal Correction in Murine Glycogen Storage Disease Type I With a Double-stranded Adeno-associated Virus Vector

    PubMed Central

    Luo, Xiaoyan; Hall, Gentzon; Li, Songtao; Bird, Andrew; Lavin, Peter J; Winn, Michelle P; Kemper, Alex R; Brown, Talmage T; Koeberl, Dwight D

    2011-01-01

    Glycogen storage disease type Ia (GSD-Ia) is caused by the deficiency of glucose-6-phosphatase (G6Pase). Long-term complications of GSD-Ia include life-threatening hypoglycemia and proteinuria progressing to renal failure. A double-stranded (ds) adeno-associated virus serotype 2 (AAV2) vector encoding human G6Pase was pseudotyped with four serotypes, AAV2, AAV7, AAV8, and AAV9, and we evaluated efficacy in 12-day-old G6pase (−/−) mice. Hypoglycemia during fasting (plasma glucose <100 mg/dl) was prevented for >6 months by the dsAAV2/7, dsAAV2/8, and dsAAV2/9 vectors. Prolonged fasting for 8 hours revealed normalization of blood glucose following dsAAV2/9 vector administration at the higher dose. The glycogen content of kidney was reduced by >65% with both the dsAAV2/7 and dsAAV2/9 vectors, and renal glycogen content was stably reduced between 7 and 12 months of age for the dsAAV2/9 vector-treated mice. Every vector-treated group had significantly reduced glycogen content in the liver, in comparison with untreated G6pase (−/−) mice. G6Pase was expressed in many renal epithelial cells of with the dsAAV2/9 vector for up to 12 months. Albuminuria and renal fibrosis were reduced by the dsAAV2/9 vector. Hepatorenal correction in G6pase (−/−) mice demonstrates the potential of AAV vectors for the correction of inherited diseases of metabolism. PMID:21730973

  10. Hydrostatic isolated limb perfusion with adeno-associated virus vectors enhances correction of skeletal muscle in Pompe disease.

    PubMed

    Sun, B; Li, S; Bird, A; Koeberl, D D

    2010-12-01

    Glycogen storage disease type II (Pompe disease; MIM 232300) stems from the inherited deficiency of acid-α-glucosidase (GAA; acid maltase; EC 3.2.1.20), which primarily involves cardiac and skeletal muscles. We hypothesized that hydrostatic isolated limb perfusion (ILP) administration of an adeno-associated virus (AAV) vector containing a muscle-specific promoter could achieve relatively higher transgene expression in the hindlimb muscles of GAA-knockout (GAA-KO) mice, in comparison with intravenous (IV) administration. ILP administration of AAV2/8 vectors encoding alkaline phosphatase or human GAA-transduced skeletal muscles of the hindlimb widely, despite the relatively low number of vector particles administered (1 × 10¹¹), and IV administration of an equivalent vector dose failed to transduce skeletal muscle detectably. Similarly, ILP administration of fewer vector particles of the AAV2/9 vector encoding human GAA (3 × 10¹⁰) transduced skeletal muscles of the hindlimb widely and significantly reduced glycogen content to, in comparison with IV administration. The only advantage for IV administration was moderately high-level transduction of cardiac muscle, which demonstrated compellingly that ILP administration sequestered vector particles within the perfused limb. Reduction of glycogen storage in the extensor digitorum longus demonstrated the potential advantage of ILP-mediated delivery of AAV vectors in Pompe disease, because type II myofibers are resistant to enzyme replacement therapy. Thus, ILP will enhance AAV transduction of multiple skeletal muscles while reducing the required dosages in terms of vector particle numbers. PMID:20686508

  11. Long-Term Efficacy Following Readministration of an Adeno-Associated Virus Vector in Dogs with Glycogen Storage Disease Type Ia

    PubMed Central

    Demaster, Amanda; Luo, Xiaoyan; Curtis, Sarah; Williams, Kyha D.; Landau, Dustin J.; Drake, Elizabeth J.; Kozink, Daniel M.; Bird, Andrew; Crane, Bayley; Sun, Francis; Pinto, Carlos R.; Brown, Talmage T.; Kemper, Alex R.

    2012-01-01

    Abstract Glycogen storage disease type Ia (GSD-Ia) is the inherited deficiency of glucose-6-phosphatase (G6Pase), primarily found in liver and kidney, which causes life-threatening hypoglycemia. Dogs with GSD-Ia were treated with double-stranded adeno-associated virus (AAV) vectors encoding human G6Pase. Administration of an AAV9 pseudotyped (AAV2/9) vector to seven consecutive GSD-Ia neonates prevented hypoglycemia during fasting for up to 8 hr; however, efficacy eventually waned between 2 and 30 months of age, and readministration of a new pseudotype was eventually required to maintain control of hypoglycemia. Three of these dogs succumbed to acute hypoglycemia between 7 and 9 weeks of age; however, this demise could have been prevented by earlier readministration an AAV vector, as demonstrated by successful prevention of mortality of three dogs treated earlier in life. Over the course of this study, six out of nine dogs survived after readministration of an AAV vector. Of these, each dog required readministration on average every 9 months. However, two were not retreated until >34 months of age, while one with preexisting antibodies was re-treated three times in 10 months. Glycogen content was normalized in the liver following vector administration, and G6Pase activity was increased in the liver of vector-treated dogs in comparison with GSD-Ia dogs that received only with dietary treatment. G6Pase activity reached approximately 40% of normal in two female dogs following AAV2/9 vector administration. Elevated aspartate transaminase in absence of inflammation indicated that hepatocellular turnover in the liver might drive the loss of vector genomes. Survival was prolonged for up to 60 months in dogs treated by readministration, and all dogs treated by readministration continue to thrive despite the demonstrated risk for recurrent hypoglycemia and mortality from waning efficacy of the AAV2/9 vector. These preclinical data support the further translation of AAV

  12. Long-term efficacy following readministration of an adeno-associated virus vector in dogs with glycogen storage disease type Ia.

    PubMed

    Demaster, Amanda; Luo, Xiaoyan; Curtis, Sarah; Williams, Kyha D; Landau, Dustin J; Drake, Elizabeth J; Kozink, Daniel M; Bird, Andrew; Crane, Bayley; Sun, Francis; Pinto, Carlos R; Brown, Talmage T; Kemper, Alex R; Koeberl, Dwight D

    2012-04-01

    Glycogen storage disease type Ia (GSD-Ia) is the inherited deficiency of glucose-6-phosphatase (G6Pase), primarily found in liver and kidney, which causes life-threatening hypoglycemia. Dogs with GSD-Ia were treated with double-stranded adeno-associated virus (AAV) vectors encoding human G6Pase. Administration of an AAV9 pseudotyped (AAV2/9) vector to seven consecutive GSD-Ia neonates prevented hypoglycemia during fasting for up to 8 hr; however, efficacy eventually waned between 2 and 30 months of age, and readministration of a new pseudotype was eventually required to maintain control of hypoglycemia. Three of these dogs succumbed to acute hypoglycemia between 7 and 9 weeks of age; however, this demise could have been prevented by earlier readministration an AAV vector, as demonstrated by successful prevention of mortality of three dogs treated earlier in life. Over the course of this study, six out of nine dogs survived after readministration of an AAV vector. Of these, each dog required readministration on average every 9 months. However, two were not retreated until >34 months of age, while one with preexisting antibodies was re-treated three times in 10 months. Glycogen content was normalized in the liver following vector administration, and G6Pase activity was increased in the liver of vector-treated dogs in comparison with GSD-Ia dogs that received only with dietary treatment. G6Pase activity reached approximately 40% of normal in two female dogs following AAV2/9 vector administration. Elevated aspartate transaminase in absence of inflammation indicated that hepatocellular turnover in the liver might drive the loss of vector genomes. Survival was prolonged for up to 60 months in dogs treated by readministration, and all dogs treated by readministration continue to thrive despite the demonstrated risk for recurrent hypoglycemia and mortality from waning efficacy of the AAV2/9 vector. These preclinical data support the further translation of AAV vector

  13. MicroRNA-regulated viral vectors for gene therapy.

    PubMed

    Geisler, Anja; Fechner, Henry

    2016-05-20

    Safe and effective gene therapy approaches require targeted tissue-specific transfer of a therapeutic transgene. Besides traditional approaches, such as transcriptional and transductional targeting, microRNA-dependent post-transcriptional suppression of transgene expression has been emerging as powerful new technology to increase the specificity of vector-mediated transgene expression. MicroRNAs are small non-coding RNAs and often expressed in a tissue-, lineage-, activation- or differentiation-specific pattern. They typically regulate gene expression by binding to imperfectly complementary sequences in the 3' untranslated region (UTR) of the mRNA. To control exogenous transgene expression, tandem repeats of artificial microRNA target sites are usually incorporated into the 3' UTR of the transgene expression cassette, leading to subsequent degradation of transgene mRNA in cells expressing the corresponding microRNA. This targeting strategy, first shown for lentiviral vectors in antigen presenting cells, has now been used for tissue-specific expression of vector-encoded therapeutic transgenes, to reduce immune response against the transgene, to control virus tropism for oncolytic virotherapy, to increase safety of live attenuated virus vaccines and to identify and select cell subsets for pluripotent stem cell therapies, respectively. This review provides an introduction into the technical mechanism underlying microRNA-regulation, highlights new developments in this field and gives an overview of applications of microRNA-regulated viral vectors for cardiac, suicide gene cancer and hematopoietic stem cell therapy, as well as for treatment of neurological and eye diseases. PMID:27226955

  14. MicroRNA-regulated viral vectors for gene therapy

    PubMed Central

    Geisler, Anja; Fechner, Henry

    2016-01-01

    Safe and effective gene therapy approaches require targeted tissue-specific transfer of a therapeutic transgene. Besides traditional approaches, such as transcriptional and transductional targeting, microRNA-dependent post-transcriptional suppression of transgene expression has been emerging as powerful new technology to increase the specificity of vector-mediated transgene expression. MicroRNAs are small non-coding RNAs and often expressed in a tissue-, lineage-, activation- or differentiation-specific pattern. They typically regulate gene expression by binding to imperfectly complementary sequences in the 3’ untranslated region (UTR) of the mRNA. To control exogenous transgene expression, tandem repeats of artificial microRNA target sites are usually incorporated into the 3’ UTR of the transgene expression cassette, leading to subsequent degradation of transgene mRNA in cells expressing the corresponding microRNA. This targeting strategy, first shown for lentiviral vectors in antigen presenting cells, has now been used for tissue-specific expression of vector-encoded therapeutic transgenes, to reduce immune response against the transgene, to control virus tropism for oncolytic virotherapy, to increase safety of live attenuated virus vaccines and to identify and select cell subsets for pluripotent stem cell therapies, respectively. This review provides an introduction into the technical mechanism underlying microRNA-regulation, highlights new developments in this field and gives an overview of applications of microRNA-regulated viral vectors for cardiac, suicide gene cancer and hematopoietic stem cell therapy, as well as for treatment of neurological and eye diseases. PMID:27226955

  15. Gene therapy for CNS diseases – Krabbe disease

    PubMed Central

    Rafi, Mohammad A.

    2016-01-01

    Summary This is a brief report of the 19th Annual Meeting of the American Society of Gene and Cell Therapy that took place from May 4th through May 7th, 2016 in Washington, DC, USA. While the meeting provided many symposiums, lectures, and scientific sessions this report mainly focuses on one of the sessions on the "Gene Therapy for central nervous system (CNS) Diseases" and specifically on the "Gene Therapy for the globoid cell leukodystrophy or Krabbe disease. Two presentations focused on this subject utilizing two animal models of this disease: mice and dog models. Different serotypes of adeno-associate viral vectors (AAV) alone or in combination with bone marrow transplantations were used in these research projects. The Meeting of the ASGCT reflected continuous growth in the fields of gene and cell therapy and brighter forecast for efficient treatment options for variety of human diseases. PMID:27525222

  16. Vector platforms for gene therapy of inherited retinopathies

    PubMed Central

    Trapani, Ivana; Puppo, Agostina; Auricchio, Alberto

    2014-01-01

    Inherited retinopathies (IR) are common untreatable blinding conditions. Most of them are inherited as monogenic disorders, due to mutations in genes expressed in retinal photoreceptors (PR) and in retinal pigment epithelium (RPE). The retina’s compatibility with gene transfer has made transduction of different retinal cell layers in small and large animal models via viral and non-viral vectors possible. The ongoing identification of novel viruses as well as modifications of existing ones based either on rational design or directed evolution have generated vector variants with improved transduction properties. Dozens of promising proofs of concept have been obtained in IR animal models with both viral and non-viral vectors, and some of them have been relayed to clinical trials. To date, recombinant vectors based on the adeno-associated virus (AAV) represent the most promising tool for retinal gene therapy, given their ability to efficiently deliver therapeutic genes to both PR and RPE and their excellent safety and efficacy profiles in humans. However, AAVs’ limited cargo capacity has prevented application of the viral vector to treatments requiring transfer of genes with a coding sequence larger than 5 kb. Vectors with larger capacity, i.e. nanoparticles, adenoviral and lentiviral vectors are being exploited for gene transfer to the retina in animal models and, more recently, in humans. This review focuses on the available platforms for retinal gene therapy to fight inherited blindness, highlights their main strengths and examines the efforts to overcome some of their limitations. PMID:25124745

  17. Global Analysis of Mouse Polyomavirus Infection Reveals Dynamic Regulation of Viral and Host Gene Expression and Promiscuous Viral RNA Editing

    PubMed Central

    Garren, Seth B.; Kondaveeti, Yuvabharath; Duff, Michael O.; Carmichael, Gordon G.

    2015-01-01

    Mouse polyomavirus (MPyV) lytically infects mouse cells, transforms rat cells in culture, and is highly oncogenic in rodents. We have used deep sequencing to follow MPyV infection of mouse NIH3T6 cells at various times after infection and analyzed both the viral and cellular transcriptomes. Alignment of sequencing reads to the viral genome illustrated the transcriptional profile of the early-to-late switch with both early-strand and late-strand RNAs being transcribed at all time points. A number of novel insights into viral gene expression emerged from these studies, including the demonstration of widespread RNA editing of viral transcripts at late times in infection. By late times in infection, 359 host genes were seen to be significantly upregulated and 857 were downregulated. Gene ontology analysis indicated transcripts involved in translation, metabolism, RNA processing, DNA methylation, and protein turnover were upregulated while transcripts involved in extracellular adhesion, cytoskeleton, zinc finger binding, SH3 domain, and GTPase activation were downregulated. The levels of a number of long noncoding RNAs were also altered. The long noncoding RNA MALAT1, which is involved in splicing speckles and used as a marker in many late-stage cancers, was noticeably downregulated, while several other abundant noncoding RNAs were strongly upregulated. We discuss these results in light of what is currently known about the MPyV life cycle and its effects on host cell growth and metabolism. PMID:26407100

  18. Minimal Ureagenesis is Necessary for Survival in the Murine Model of Hyperargininemia Treated by AAV-based Gene Therapy

    PubMed Central

    Hu, Chuhong; Tai, Denise S.; Park, Hana; Cantero-Nieto, Gloria; Chan, Emily; Yudkoff, Marc; Cederbaum, Stephen D.; Lipshutz, Gerald S.

    2014-01-01

    Hyperammonemia is less severe in arginase 1 deficiency compared with other urea cycle defects. Affected patients manifest hyperargininemia and infrequent episodes of hyperammonemia. Patients typically suffer from neurological impairment with cortical and pyramidal tract deterioration, spasticity, loss of ambulation, seizures, and intellectual disability; death is less common than with other urea cycle disorders. In a mouse model of arginase I deficiency, the onset of symptoms begins with weight loss and gait instability which progresses to development of tail tremor with seizure-like activity; death typically occurs at about two weeks of life. Adeno-associated viral vector gene replacement strategies result in long-term survival of mice with this disorder. With neonatal administration of vector, the viral copy number in the liver greatly declines with hepatocyte proliferation in the first 5 weeks of life. While the animals do survive, it is not known from a functional standpoint how well the urea cycle is functioning in the adult animals that receive adeno-associated virus. In these studies we administered [1-13C] acetate to both littermate controls and adeno-associated virus-treated arginase 1 knockout animals and examined flux through the urea cycle. Circulating ammonia levels were mildly elevated in treated animals. Arginine and glutamine also had perturbations. Assessment thirty minutes after acetate administration demonstrated that ureagenesis was present in the treated knockout liver at levels as low at 3.3% of control animals. These studies demonstrate that only minimal levels of hepatic arginase activity are necessary for survival and ureagenesis in arginase deficient mice and that this level of activity results in control of circulating ammonia. These results may have implications for potential therapy in humans with arginase deficiency. PMID:25474440

  19. Kinetics of the establishment of HIV-1 viral interference and comprehensive analysis of the contribution of viral genes.

    PubMed

    Remion, Azaria; Delord, Marc; Hance, Allan J; Saragosti, Sentob; Mammano, Fabrizio

    2016-01-01

    Viral interference defines the reduced susceptibility of an infected cell to reinfection. For HIV-1, both receptor-dependent and independent pathways were described. The relative importance of different receptor-independent pathways has not been addressed. We have used reporter viruses to quantify the percentage of single- and double-infected cells, as a function of the delay between the two infections. For co-infection experiments, the frequency of double infected cells was higher than expected for independent events. By delaying the second infection, this frequency progressively diminished, resulting in significant interference after 18h. Interference measured here was largely receptor-independent. By individually deleting viral genes or expressing them in isolation, we demonstrate that the viral protein Rev plays a dominant role, while other viral proteins contributes to optimal interference. Our study defines the kinetics of early HIV-1 interference, describing the transition from higher susceptibility to double-infection to viral interference, and identifies Rev as its dominant effector. PMID:26499042

  20. Gene Expression Signatures Diagnose Influenza and Other Symptomatic Respiratory Viral Infection in Humans

    PubMed Central

    Zaas, Aimee K.; Chen, Minhua; Varkey, Jay; Veldman, Timothy; Hero, Alfred O.; Lucas, Joseph; Huang, Yongsheng; Turner, Ronald; Gilbert, Anthony; Lambkin-Williams, Robert; Øien, N. Christine; Nicholson, Bradly; Kingsmore, Stephen; Carin, Lawrence; Woods, Christopher W.; Ginsburg, Geoffrey S.

    2010-01-01

    Summary Acute respiratory infections (ARI) are a common reason for seeking medical attention and the threat of pandemic influenza will likely add to these numbers. Using human viral challenge studies with live rhinovirus, respiratory syncytial virus, and influenza A, we developed peripheral blood gene expression signatures that distinguish individuals with symptomatic ARI from uninfected individuals with > 95% accuracy. We validated this “acute respiratory viral” signature - encompassing genes with a known role in host defense against viral infections - across each viral challenge. We also validated the signature in an independently acquired dataset for influenza A and classified infected individuals from healthy controls with 100% accuracy. In the same dataset, we could also distinguish viral from bacterial ARIs (93% accuracy). These results demonstrate that ARIs induce changes in human peripheral blood gene expression that can be used to diagnose a viral etiology of respiratory infection and triage symptomatic individuals. PMID:19664979

  1. Gene therapy in epilepsy

    PubMed Central

    Riban, Véronique; Fitzsimons, Helen L.; During, Matthew J.

    2009-01-01

    SUMMARY Results from animal models suggest gene therapy is a promising new approach for the treatment of epilepsy. Several candidate genes such as neuropeptide Y and galanin have been demonstrated in preclinical studies to have a positive effect on seizure activity. For a successful gene therapy-based treatment, efficient delivery of a transgene to target neurons is also essential. To this end, advances have been made in the areas of cell transplantation and in the development of recombinant viral vectors for gene delivery. Recombinant adeno-associated viral (rAAV) vectors in particular show promise for gene therapy of neurological disorders due to their neuronal tropism, lack of toxicity, and stable persistence in neurons, which results in robust, long-term expression of the transgene. rAAV vectors have been recently used in phase I clinical trials of Parkinson’s disease with an excellent safety profile. Prior to commencement of phase I trials for gene therapy of epilepsy, further preclinical studies are ongoing including evaluation of the therapeutic benefit in chronicmodels of epileptogenesis, as well as assessment of safety intoxicological studies. PMID:18717707

  2. Calcium-ion-modulated ceramic hydroxyapatite resin for the scalable purification of recombinant Adeno-Associated Virus serotype 9.

    PubMed

    Qu, Weihong; Wang, Mingxi; Wu, Yaqing; Lv, Yinghui; Wang, Qizhao; Xu, Ruian

    2015-05-15

    Column chromatography has been widely used as a scalable purification strategy for recombinant adeno-associated virus (rAAV) vectors. The rAAV1, 2, 4, 5, 6, 8 and 9 serotypes could be separated using affinity resins, ion exchange resins or other types of resins. Apatite resin has displayed outstanding performance in protein purification in the past 10 years, and ceramic hydroxyapatite (CHT) chromatography resin with a polyethylene glycol (PEG) modulation has recently been used for rAAV1 and rAAV9 vectors. This study reports the use of CHT chromatography modulated by calcium ions instead of PEG for rAAV9 purification. Calcium-ion-containing buffers effectively improve the inclusion of CHT as a capture resin, the resin-binding capacity and the yield. The optimum calcium ion concentration is 30ppm, and the optimum pH is 7.0. A frontal analysis indicated that the binding capacity of CHT at 2ml/min reaches 65.1mg total protein per ml of resin. A previously developed purification strategy consists of CHT followed by ANX anion exchange chromatography. The vector yield of this approach is approximately 70%, and a software analysis indicated a vector purity exceeding 98%. The residual host cell (HEK293) protein contents are 24.75±2.32ng and 67.21±2.10ng, and the Benzonase residue contents are 1.55±0.10pg and 1.95±0.16ng per 10(13) vector genome copies (G.C.) separated by CHT/ANX and CsCl. In addition, CHT/ANX yields 798.44±50.10pg of plasmid DNA and 2.17±0.11ng of HEK293 DNA, while CsCl purification yields 840.27±76.14pg of plasmid DNA and 2.43±0.19 of HEK293 DNA. The two methods produce vectors with similar in vitro and in vivo potencies. The results indicated that the CHT/ANX method is suitable for the scalable purification of the rAAV9 vector. PMID:25841202

  3. Adeno-Associated Virus Capsid Proteins May Play a Role in Transcription and Second-Strand Synthesis of Recombinant Genomes

    PubMed Central

    Salganik, Maxim; Aydemir, Fikret; Nam, Hyun-Joo; McKenna, Robert; Agbandje-McKenna, Mavis

    2014-01-01

    A group of four interacting amino acids in adeno-associated virus type 8 (AAV8) called the pH quartet has been shown to undergo a structural change when subjected to acidic pH comparable to that seen in endosomal compartments. We examined the phenotypes of mutants with mutations in these amino acids as well as several nearby residues in the background of AAV2. We found that three of the mutations in this region (Y704A, E562A, and E564A) produce normal titers of mature capsids but are extremely defective for transduction (>107-fold). The remaining mutants were also defective for transduction, but the defect in these mutants (E563A, E561A, H526A, and R389A) is not as severe (3- to 22-fold). Two other mutants (Y700A and Y730A) were found to be defective for virus assembly. One of the extremely defective mutants (Y704A) was found to enter the cell, traffic to the nucleus, and uncoat its DNA nearly as efficiently as the wild type. This suggested that some step after nuclear entry and uncoating was defective. To see if the extremely defective mutants were impaired in second-strand synthesis, the Y704A, E562A, and E564A mutants containing self-complementary DNA were compared with virus containing single-stranded genomes. Two of the mutants (Y704A and E564A) showed 1-log and 3-log improvements in infectivity, respectively, while the third mutant (E562A) showed no change. This suggested that inhibition of second-strand synthesis was responsible for some but not most of the defect in these mutants. Comparison of Y704A mRNA synthesis with that of the wild-type capsid showed that accumulation of steady-state mRNA in the Y704A mutant was reduced 450-fold, even though equal genome numbers were uncoated. Our experiments have identified a novel capsid function. They suggest that AAV capsids may play a role in the initiation of both second-strand synthesis and transcription of the input genome. PMID:24198419

  4. Coupled Transcriptome and Proteome Analysis of Human Lymphotropic Tumor Viruses: Insights on the Detection and Discovery of Viral Genes

    SciTech Connect

    Dresang, Lindsay R.; Teuton, Jeremy R.; Feng, Huichen; Jacobs, Jon M.; Camp, David G.; Purvine, Samuel O.; Gritsenko, Marina A.; Li, Zhihua; Smith, Richard D.; Sugden, Bill; Moore, Patrick S.; Chang, Yuan

    2011-12-20

    Kaposi's sarcoma-associated herpesvirus (KSHV) and Epstein-Barr virus (EBV) are related human tumor viruses that cause primary effusion lymphomas (PEL) and Burkitt's lymphomas (BL), respectively. Viral genes expressed in naturally-infected cancer cells contribute to disease pathogenesis; knowing which viral genes are expressed is critical in understanding how these viruses cause cancer. To evaluate the expression of viral genes, we used high-resolution separation and mass spectrometry coupled with custom tiling arrays to align the viral proteomes and transcriptomes of three PEL and two BL cell lines under latent and lytic culture conditions. Results The majority of viral genes were efficiently detected at the transcript and/or protein level on manipulating the viral life cycle. Overall the correlation of expressed viral proteins and transcripts was highly complementary in both validating and providing orthogonal data with latent/lytic viral gene expression. Our approach also identified novel viral genes in both KSHV and EBV, and extends viral genome annotation. Several previously uncharacterized genes were validated at both transcript and protein levels. Conclusions This systems biology approach coupling proteome and transcriptome measurements provides a comprehensive view of viral gene expression that could not have been attained using each methodology independently. Detection of viral proteins in combination with viral transcripts is a potentially powerful method for establishing virus-disease relationships.

  5. Adeno-Associated Virus Type 2 Rep68 Can Bind to Consensus Rep-Binding Sites on the Herpes Simplex Virus 1 Genome

    PubMed Central

    Seyffert, Michael; Glauser, Daniel L.; Tobler, Kurt; Georgiev, Oleg; Vogel, Rebecca; Vogt, Bernd; Agúndez, Leticia; Linden, Michael; Büning, Hildegard; Ackermann, Mathias

    2015-01-01

    Adeno-associated virus type 2 is known to inhibit replication of herpes simplex virus 1 (HSV-1). This activity has been linked to the helicase- and DNA-binding domains of the Rep68/Rep78 proteins. Here, we show that Rep68 can bind to consensus Rep-binding sites on the HSV-1 genome and that the Rep helicase activity can inhibit replication of any DNA if binding is facilitated. Therefore, we hypothesize that inhibition of HSV-1 replication involves direct binding of Rep68/Rep78 to the HSV-1 genome. PMID:26292324

  6. Adeno-Associated Virus Type 2 Wild-Type and Vector-Mediated Genomic Integration Profiles of Human Diploid Fibroblasts Analyzed by Third-Generation PacBio DNA Sequencing

    PubMed Central

    Hüser, Daniela; Gogol-Döring, Andreas; Chen, Wei

    2014-01-01

    ABSTRACT Genome-wide analysis of adeno-associated virus (AAV) type 2 integration in HeLa cells has shown that wild-type AAV integrates at numerous genomic sites, including AAVS1 on chromosome 19q13.42. Multiple GAGY/C repeats, resembling consensus AAV Rep-binding sites are preferred, whereas rep-deficient AAV vectors (rAAV) regularly show a random integration profile. This study is the first study to analyze wild-type AAV integration in diploid human fibroblasts. Applying high-throughput third-generation PacBio-based DNA sequencing, integration profiles of wild-type AAV and rAAV are compared side by side. Bioinformatic analysis reveals that both wild-type AAV and rAAV prefer open chromatin regions. Although genomic features of AAV integration largely reproduce previous findings, the pattern of integration hot spots differs from that described in HeLa cells before. DNase-Seq data for human fibroblasts and for HeLa cells reveal variant chromatin accessibility at preferred AAV integration hot spots that correlates with variant hot spot preferences. DNase-Seq patterns of these sites in human tissues, including liver, muscle, heart, brain, skin, and embryonic stem cells further underline variant chromatin accessibility. In summary, AAV integration is dependent on cell-type-specific, variant chromatin accessibility leading to random integration profiles for rAAV, whereas wild-type AAV integration sites cluster near GAGY/C repeats. IMPORTANCE Adeno-associated virus type 2 (AAV) is assumed to establish latency by chromosomal integration of its DNA. This is the first genome-wide analysis of wild-type AAV2 integration in diploid human cells and the first to compare wild-type to recombinant AAV vector integration side by side under identical experimental conditions. Major determinants of wild-type AAV integration represent open chromatin regions with accessible consensus AAV Rep-binding sites. The variant chromatin accessibility of different human tissues or cell types will

  7. Adeno-associated virus (AAV) Rep proteins mediate complex formation between AAV DNA and its integration site in human DNA.

    PubMed Central

    Weitzman, M D; Kyöstiö, S R; Kotin, R M; Owens, R A

    1994-01-01

    AAV is unique among eukaryotic viruses in the ability of its DNA to integrate preferentially into a specific region of the human genome. Understanding AAV integration may aid in developing gene therapy systems with predictable integration sites. Using a gel mobility-shift assay, we have identified a DNA sequence within the AAV integration locus on human chromosome 19 which is specifically bound by the AAV Rep78 and Rep68 proteins. This Rep recognition sequence is a GCTC repeating motif very similar to sequences within the inverted terminal repeats of the AAV genome which are also bound by Rep78 and Rep68. Cloned oligonucleotides containing the recognition sequence can direct specific binding by Rep proteins. Binding assays with mutant Rep proteins show that the amino-terminal portion of Rep78 and Rep68 can direct binding to either the AAV terminal repeat hairpin DNA or chromosome 19. This human genomic DNA can be complexed with AAV DNA by Rep proteins as demonstrated by a dual-label (32P/biotin) assay. These results suggest a role for Rep in targeting viral integration. Images PMID:8016070

  8. Herpesvirus-dependent amplification and inversion of cell-associated viral thymidine kinase gene flanked by viral a sequences and linked to an origin of viral DNA replication.

    PubMed Central

    Mocarski, E S; Roizman, B

    1982-01-01

    The genome of herpes simplex virus 1 or 2 consists of two components, L and S, which invert relative to each other during infection. As a result, viral DNA consists of four equimolar populations of molecules differing solely in the relative orientations of the L and S components. Previous studies have shown that the a sequences, located in the same orientation at the genomic termini and in inverted orientation at the L-S junction, play a key role in the inversion of L and S components. In this report we describe a virus-dependent system designed to allow identification of the viral genes capable of acting in trans to invert DNA flanked by inverted copies of a sequences. In this system, cells are converted to the thymidine kinase-positive phenotype with a chimeric plasmid carrying the thymidine kinase gene flanked by inverted copies of the a sequence and linked to an origin of viral DNA replication derived from the S component. The DNA introduced into the cells is retained and propagated in its original sequence arrangement as head-to-tail concatemers. Infection of these cells with herpes simplex virus 1 or 2 results in as much as 100-fold amplification of the plasmid sequences and inversion of the DNA flanked by copies of the a sequence. In infected cells, the amplified resident DNA accumulates in head-to-tail concatemers and no rearrangement other than the inversions could be detected. These results suggest that the a sequence-dependent inversions required trans-acting viral gene products. Images PMID:6291055

  9. Hybrid nonviral/viral vector systems for improved piggyBac DNA transposon in vivo delivery.

    PubMed

    Cooney, Ashley L; Singh, Brajesh K; Sinn, Patrick L

    2015-04-01

    The DNA transposon piggyBac is a potential therapeutic agent for multiple genetic diseases such as cystic fibrosis (CF). Recombinant piggyBac transposon and transposase are typically codelivered by plasmid transfection; however, plasmid delivery is inefficient in somatic cells in vivo and is a barrier to the therapeutic application of transposon-based vector systems. Here, we investigate the potential for hybrid piggyBac/viral vectors to transduce cells and support transposase-mediated genomic integration of the transposon. We tested both adenovirus (Ad) and adeno-associated virus (AAV) as transposon delivery vehicles. An Ad vector expressing hyperactive insect piggyBac transposase (iPB7) was codelivered. We show transposase-dependent transposition activity and mapped integrations in mammalian cells in vitro and in vivo from each viral vector platform. We also demonstrate efficient and persistent transgene expression following nasal delivery of piggyBac/viral vectors to mice. Furthermore, using piggyBac/Ad expressing Cystic Fibrosis transmembrane Conductance Regulator (CFTR), we show persistent correction of chloride current in well-differentiated primary cultures of human airway epithelial cells derived from CF patients. Combining the emerging technologies of DNA transposon-based vectors with well-studied adenoviral and AAV delivery provides new tools for in vivo gene transfer and presents an exciting opportunity to increase the delivery efficiency for therapeutic genes such as CFTR. PMID:25557623

  10. A viral satellite DNA vector-induced transcriptional gene silencing via DNA methylation of gene promoter in Nicotiana benthamiana.

    PubMed

    Ju, Zheng; Wang, Lei; Cao, Dongyan; Zuo, Jinhua; Zhu, Hongliang; Fu, Daqi; Luo, Yunbo; Zhu, Benzhong

    2016-09-01

    Virus-induced gene silencing (VIGS) has been widely used for plant functional genomics study at the post-transcriptional level using various DNA or RNA viral vectors. However, while virus-induced transcriptional gene silencing (VITGS) via DNA methylation of gene promoter was achieved using several plant RNA viral vectors, it has not yet been done using a satellite DNA viral vector. In this study, a viral satellite DNA associated with tomato yellow leaf curl China virus (TYLCCNV), which has been modified as a VIGS vector in previous research, was developed as a VITGS vector. Firstly, the viral satellite DNA VIGS vector was further optimized to a more convenient p1.7A+2mβ vector with high silencing efficiency of the phytoene desaturase (PDS) gene in Nicotiana benthamiana plants. Secondly, the constructed VITGS vector (TYLCCNV:35S), which carried a portion of the cauliflower mosaic virus 35S promoter, could successfully induce heritable transcriptional gene silencing (TGS) of the green fluorescent protein (GFP) gene in the 35S-GFP transgenic N. benthamiana line 16c plants. Moreover, bisulfite sequencing results revealed higher methylated cytosine residues at CG, CHG and CHH sites of the 35S promoter sequence in TYLCCNV:35S-inoculated plants than in TYLCCNV-inoculated line 16c plants (control). Overall, these results demonstrated that the viral satellite DNA vector could be used as an effective VITGS vector to study DNA methylation in plant genomes. PMID:27422476

  11. Intracranial delivery of interleukin-17A via adeno-associated virus fails to induce physical and learning disabilities and neuroinflammation in mice but improves glucose metabolism through AKT signaling pathway.

    PubMed

    Yang, Junling; Kou, Jinghong; Lim, Jeong-Eun; Lalonde, Robert; Fukuchi, Ken-Ichiro

    2016-03-01

    Interleukin-17A (IL-17A) is generally considered as one of the pathogenic factors involved in multiple sclerosis (MS). Indirect evidence for this is that IL-17A-producing T helper 17 (Th17) cells preferentially accumulate in lesions of MS and experimental autoimmune encephalomyelitis (EAE). However, a direct involvement of IL-17A in MS pathogenesis is still an open question. In this study, we overexpressed IL-17A in the brains of mice (IL-17A-in-Brain mice) via recombinant adeno-associated virus serotype 5 (rAAV5)-mediated gene delivery. In spite of high levels of IL-17A expression in the brain and blood, IL-17A-in-Brain mice exhibit no inflammatory responses and no abnormalities in motor coordination and spatial orientation. Unexpectedly, IL-17A-in-Brain mice show decreases in body weight and adipose tissue mass and an improvement in glucose tolerance and insulin sensitivity. IL-17A enhances glucose uptake in PC12 cells by activation of AKT. Our results provide direct evidence for the first time that IL-17A overexpression in the central nervous system does not cause physical and learning disabilities and neuroinflammation and suggest that IL-17A may regulate glucose metabolism through the AKT signaling pathway. PMID:26562537

  12. Gene Expression Profiles Link Respiratory Viral Infection, Platelet Response to Aspirin, and Acute Myocardial Infarction

    PubMed Central

    Cyr, Derek D.; Lucas, Joseph E.; Zaas, Aimee K.; Woods, Christopher W.; Newby, L. Kristin; Kraus, William E.; Ginsburg, Geoffrey S.

    2015-01-01

    Background Influenza infection is associated with myocardial infarction (MI), suggesting that respiratory viral infection may induce biologic pathways that contribute to MI. We tested the hypotheses that 1) a validated blood gene expression signature of respiratory viral infection (viral GES) was associated with MI and 2) respiratory viral exposure changes levels of a validated platelet gene expression signature (platelet GES) of platelet function in response to aspirin that is associated with MI. Methods A previously defined viral GES was projected into blood RNA data from 594 patients undergoing elective cardiac catheterization and used to classify patients as having evidence of viral infection or not and tested for association with acute MI using logistic regression. A previously defined platelet GES was projected into blood RNA data from 81 healthy subjects before and after exposure to four respiratory viruses: Respiratory Syncytial Virus (RSV) (n=20), Human Rhinovirus (HRV) (n=20), Influenza A virus subtype H1N1 (H1N1) (n=24), Influenza A Virus subtype H3N2 (H3N2) (n=17). We tested for the change in platelet GES with viral exposure using linear mixed-effects regression and by symptom status. Results In the catheterization cohort, 32 patients had evidence of viral infection based upon the viral GES, of which 25% (8/32) had MI versus 12.2% (69/567) among those without evidence of viral infection (OR 2.3; CI [1.03-5.5], p=0.04). In the infection cohorts, only H1N1 exposure increased platelet GES over time (time course p-value = 1e-04). Conclusions A viral GES of non-specific, respiratory viral infection was associated with acute MI; 18% of the top 49 genes in the viral GES are involved with hemostasis and/or platelet aggregation. Separately, H1N1 exposure, but not exposure to other respiratory viruses, increased a platelet GES previously shown to be associated with MI. Together, these results highlight specific genes and pathways that link viral infection

  13. Non-viral gene delivery regulated by stiffness of cell adhesion substrates

    NASA Astrophysics Data System (ADS)

    Kong, Hyun Joon; Liu, Jodi; Riddle, Kathryn; Matsumoto, Takuya; Leach, Kent; Mooney, David J.

    2005-06-01

    Non-viral gene vectors are commonly used for gene therapy owing to safety concerns with viral vectors. However, non-viral vectors are plagued by low levels of gene transfection and cellular expression. Current efforts to improve the efficiency of non-viral gene delivery are focused on manipulations of the delivery vector, whereas the influence of the cellular environment in DNA uptake is often ignored. The mechanical properties (for example, rigidity) of the substrate to which a cell adheres have been found to mediate many aspects of cell function including proliferation, migration and differentiation, and this suggests that the mechanics of the adhesion substrate may regulate a cell's ability to uptake exogeneous signalling molecules. In this report, we present a critical role for the rigidity of the cell adhesion substrate on the level of gene transfer and expression. The mechanism relates to material control over cell proliferation, and was investigated using a fluorescent resonance energy transfer (FRET) technique. This study provides a new material-based control point for non-viral gene therapy.

  14. Limbal Approach-Subretinal Injection of Viral Vectors for Gene Therapy in Mice Retinal Pigment Epithelium.

    PubMed

    Park, Sung Wook; Kim, Jin Hyoung; Park, Woo Jin; Kim, Jeong Hun

    2015-01-01

    The eye is a small and enclosed organ which makes it an ideal target for gene therapy. Recently various strategies have been applied to gene therapy in retinopathies using non-viral and viral gene delivery to the retina and retinal pigment epithelium (RPE). Subretinal injection is the best approach to deliver viral vectors directly to RPE cells. Before the clinical trial of a gene therapy, it is inevitable to validate the efficacy of the therapy in animal models of various retinopathies. Thus, subretinal injection in mice becomes a fundamental technique for an ocular gene therapy. In this protocol, we provide the easy and replicable technique for subretinal injection of viral vectors to experimental mice. This technique is modified from the intravitreal injection, which is widely used technique in ophthalmology clinics. The representative results of RPE/choroid/scleral complex flat-mount will help to understand the efficacy of this technique and adjust the volume and titer of viral vectors for the extent of gene transduction. PMID:26274541

  15. The Epstein-Barr Virus BDLF4 Gene Is Required for Efficient Expression of Viral Late Lytic Genes

    PubMed Central

    Watanabe, Takahiro; Narita, Yohei; Yoshida, Masahiro; Sato, Yoshitaka; Goshima, Fumi; Kimura, Hiroshi

    2015-01-01

    Epstein-Barr virus (EBV) is a gammaherpesvirus, associated with infectious mononucleosis and various types of malignancy. We focused here on the BDLF4 gene of EBV and identified it as a lytic gene, expressed with early kinetics. Viral late gene expression of the BDLF4 knockout strain was severely restricted; this could be restored by an exogenous supply of BDLF4. These results indicate that BDLF4 is important for the EBV lytic replication cycle, especially in late gene expression. PMID:26202235

  16. Comparison of Efficacy of the Disease-Specific LOX1- and Constitutive Cytomegalovirus-Promoters in Expressing Interleukin 10 through Adeno-Associated Virus 2/8 Delivery in Atherosclerotic Mice

    PubMed Central

    Zhu, Hongqing; Cao, Maohua; Mirandola, Leonardo; Figueroa, Jose A.; Cobos, Everardo; Chiriva-Internati, Maurizio; Hermonat, Paul L.

    2014-01-01

    The development of gene therapy vectors for treating diseases of the cardiovascular system continues at a steady pace. Moreover, in the field of gene therapy the utility of “disease-specific promoters” has strong appeal. Many therapeutic genes, including transforming growth factor beta 1 or interleukin 10, are associated to adverse effects. The use of a disease-specific promoter might minimize toxicity. The lectin-like oxidized low density lipoprotein receptor 1 is a marker of cardiovascular disease and a potential therapeutic target. The lectin-like oxidized low density lipoprotein receptor 1 is known to be up-regulated early during disease onset in a number of cell types at the sites where the disease will be clinically evident. In this study an adeno-associated virus-2 DNA vector (AAV2) using the AAV8 capsid, and containing the full length The lectin-like oxidized low density lipoprotein receptor 1 promoter, was generated and assayed for its ability to express human interleukin 10 in low density lipoprotein receptor knockout mice on high cholesterol diet. The cytomegalovirus early promoter was used for comparison in a similarly structured vector. The two promoters were found to have equal efficacy in reducing atherogenesis as measured by aortic systolic blood velocity, aortic cross sectional area, and aortic wall thickness. This is the first head-to-head comparison of a constitutive with a disease-specific promoter in a therapeutic context. These data strongly suggest that the use of a disease-specific promoter is appropriate for therapeutic gene delivery. PMID:24736312

  17. The role of viral and host genes in corneal infection with herpes simplex virus type 1.

    PubMed

    Brandt, Curtis R

    2005-05-01

    Herpes simplex virus infection of the eye is the leading cause of blindness due to infection in the US despite the availability of several antiviral drugs. Studies with animal models have shown that three factors, innate host resistance, the host adaptive immune response, and the strain of virus interact to determine whether an infection is asymptomatic or proceeds to the development of blinding keratitis (HSK). Of these, the role of adaptive immunity has received the most attention. This work has clearly shown that stromal keratitis is an immunopathological disease, most likely due to the induction of a delayed type hypersensitivity response. Substantially less is known about the role of specific host genes in resistance to HSK. The fact that different strains of virus display different disease phenotypes indicates that viral 'virulence' genes are critical. Of the 80 plus HSV genes, few have been formally tested for their role in HSV keratitis. Most studies of virulence genes to date have focused on a single gene or protein and large changes in disease phenotypes are usually measured. Large changes in the ability to cause disease are likely to reduce the fitness of the virus, thus such studies, although useful, do not mimic the natural situation. Viral gene products are known to interact with each other, and with host proteins and these interactions are critical in determining the outcome of infection. In reality, the 'constellation' of genes encoded by each particular strain is critical, and how this constellation of genes works together and with host proteins determines the outcome of an infection. The goal of this review is to discuss the current state of knowledge regarding the role of host and viral genes in HSV keratitis. The roles of specific genes that have been shown to influence keratitis are discussed. Recent data showing that different viral genes cooperate to influence disease severity and confirming that the constellation of genes within a particular

  18. Comprehensive analysis of HPV16 integration in OSCC reveals no significant impact of physical status on viral oncogene and virally disrupted human gene expression.

    PubMed

    Olthof, Nadine C; Speel, Ernst-Jan M; Kolligs, Jutta; Haesevoets, Annick; Henfling, Mieke; Ramaekers, Frans C S; Preuss, Simon F; Drebber, Uta; Wieland, Ulrike; Silling, Steffi; Lam, Wan L; Vucic, Emily A; Kremer, Bernd; Klussmann, Jens-P; Huebbers, Christian U

    2014-01-01

    Infection with high-risk human papillomavirus (HPV) type 16 is an independent risk factor for the development of oropharyngeal squamous cell carcinomas (OSCC). However, it is unclear whether viral integration is an essential hallmark in the carcinogenic process of OSCC and whether HPV integration correlates with the level of viral gene transcription and influences the expression of disrupted host genes. We analyzed 75 patients with OSCC. HPV16-positivity was proven by p16(INK4A) immunohistochemistry, PCR and FISH. Viral integration was examined using DIPS- as well as APOT-PCR. Viral E2, E6 and E7 gene expression levels were quantified by quantitative reverse transcriptase (RT-q)PCR. Expression levels of 7 human genes disrupted by the virus were extracted from mRNA expression profiling data of 32 OSCCs. Viral copy numbers were assessed by qPCR in 73 tumors. We identified 37 HPV16-human fusion products indicating viral integration in 29 (39%) OSCC. In the remaining tumors (61%) only episome-derived PCR products were detected. When comparing OSCC with or without an integration-derived fusion product, we did not find significant differences in the mean RNA expression of viral genes E2, E6 and E7 or the viral copy numbers per cell, nor did the RNA expression of the HPV-disrupted genes differ from either group of OSCC. In conclusion, our data do not support the hypothesis that integration affects the levels of viral and/or HPV-disrupted human gene transcripts. Thus constitutive, rather than a high level, of expression of oncogene transcripts appears to be required in HPV-related OSCC. PMID:24586376

  19. In vitro evaluation of mitochondrial dysfunction and treatment with adeno-associated virus vector in fibroblasts from Doberman Pinschers with dilated cardiomyopathy and a pyruvate dehydrogenase kinase 4 mutation.

    PubMed

    Sosa, Ivan; Estrada, Amara H; Winter, Brandy D; Erger, Kirsten E; Conlon, Thomas J

    2016-02-01

    OBJECTIVE To compare mitochondrial oxygen consumption rate (OCR) of fibroblasts from Doberman Pinschers with and without dilated cardiomyopathy (DCM) and mutation of the gene for pyruvate dehydrogenase kinase isozyme 4 (PDK4) and to evaluate in vitro whether treatment with adeno-associated virus (AAV) vector (ie, gene therapy) would alter metabolic efficiency. ANIMALS 10 Doberman Pinschers screened for DCM and PDK4 mutation. PROCEDURES Fibroblasts were harvested from skin biopsy specimens obtained from Doberman Pinschers, and dogs were classified as without DCM or PDK4 mutation (n = 3) or with occult DCM and heterozygous (4) or homozygous (3) for PDK4 mutation. Fibroblasts were or were not treated with tyrosine mutant AAV type 2 vector containing PDK4 at multiplicities of infection of 1,000. Mitochondrial OCR was measured to evaluate mitochondrial metabolism. The OCR was compared among dog groups and between untreated and treated fibroblasts within groups. RESULTS Mean ± SD basal OCR of fibroblasts from heterozygous (74 ± 8 pmol of O2/min) and homozygous (58 ± 12 pmol of O2/min) dogs was significantly lower than that for dogs without PDK4 mutation (115 ± 9 pmol of O2/min). After AAV transduction, OCR did not increase significantly in any group (mutation-free group, 121 ± 26 pmol of O2/min; heterozygous group, 88 ± 6 pmol of O2/min; homozygous group, 59 ± 3 pmol of O2/min). CONCLUSIONS AND CLINICAL RELEVANCE Mitochondrial function was altered in skin fibroblasts of Doberman Pinschers with DCM and PDK4 mutation. Change in mitochondrial function after in vitro gene therapy at the multiplicities of infection used in this study was not significant. (Am J Vet Res 2016;77:156-161). PMID:27027709

  20. Challenges and Prospects for Alpha-1 Antitrypsin Deficiency Gene Therapy.

    PubMed

    Wozniak, Joanna; Wandtke, Tomasz; Kopinski, Piotr; Chorostowska-Wynimko, Joanna

    2015-11-01

    Alpha-1 antitrypsin (AAT) is a protease inhibitor belonging to the serpin family. A number of identified mutations in the SERPINA1 gene encoding this protein result in alpha-1 antitrypsin deficiency (AATD). A decrease in AAT serum concentration or reduced biological activity causes considerable risk of chronic respiratory and liver disorders. As a monogenic disease, AATD appears to be an attractive target for gene therapy, particularly for patients with pulmonary dysfunction, where augmentation of functional AAT levels in plasma might slow down respiratory disease development. The short AAT coding sequence and its activity in the extracellular matrix would enable an increase in systemic serum AAT production by cellular secretion. In vitro and in vivo experimental AAT gene transfer with gamma-retroviral, lentiviral, adenoviral, and adeno-associated viral (AAV) vectors has resulted in enhanced AAT serum levels and a promising safety profile. Human clinical trials using intramuscular viral transfer with AAV1 and AAV2 vectors of the AAT gene demonstrated its safety, but did not achieve a protective level of AAT >11 μM in serum. This review provides an in-depth critical analysis of current progress in AATD gene therapy based on viral gene transfer. The factors affecting transgene expression levels, such as site of administration, dose and type of vector, and activity of the immune system, are discussed further as crucial variables for optimizing the clinical effectiveness of gene therapy in AATD subjects. PMID:26413996

  1. Functional Annotation of Cotesia congregata Bracovirus: Identification of Viral Genes Expressed in Parasitized Host Immune Tissues

    PubMed Central

    Thézé, Julien; Cambier, Sébastien; Poulain, Julie; Da Silva, Corinne; Bézier, Annie; Musset, Karine; Moreau, Sébastien J. M.; Drezen, Jean-Michel

    2014-01-01

    ABSTRACT Bracoviruses (BVs) from the Polydnaviridae family are symbiotic viruses used as biological weapons by parasitoid wasps to manipulate lepidopteran host physiology and induce parasitism success. BV particles are produced by wasp ovaries and injected along with the eggs into the caterpillar host body, where viral gene expression is necessary for wasp development. Recent sequencing of the proviral genome of Cotesia congregata BV (CcBV) identified 222 predicted virulence genes present on 35 proviral segments integrated into the wasp genome. To date, the expressions of only a few selected candidate virulence genes have been studied in the caterpillar host, and we lacked a global vision of viral gene expression. In this study, a large-scale transcriptomic analysis by 454 sequencing of two immune tissues (fat body and hemocytes) of parasitized Manduca sexta caterpillar hosts allowed the detection of expression of 88 CcBV genes expressed 24 h after the onset of parasitism. We linked the expression profiles of these genes to several factors, showing that different regulatory mechanisms control viral gene expression in the host. These factors include the presence of signal peptides in encoded proteins, diversification of promoter regions, and, more surprisingly, gene position on the proviral genome. Indeed, most genes for which expression could be detected are localized in particular proviral regions globally producing higher numbers of circles. Moreover, this polydnavirus (PDV) transcriptomic analysis also reveals that a majority of CcBV genes possess at least one intron and an arthropod transcription start site, consistent with an insect origin of these virulence genes. IMPORTANCE Bracoviruses (BVs) are symbiotic polydnaviruses used by parasitoid wasps to manipulate lepidopteran host physiology, ensuring wasp offspring survival. To date, the expressions of only a few selected candidate BV virulence genes have been studied in caterpillar hosts. We performed a large

  2. A knot polymer mediated non-viral gene transfection for skin cells.

    PubMed

    Cutlar, Lara; Gao, Yongsheng; Aied, Ahmed; Greiser, Udo; Murauer, Eva Maria; Zhou, Dezhong; Wang, Wenxin

    2016-01-01

    A knot polymer, poly[bis(2-acryloyl)oxyethyl disulphide-co-2-(dimethylamino) ethyl methacrylate] (DSP), was synthesized, optimized and evaluated as a non-viral vector for gene transfection for skin cells, keratinocytes. With recessive dystrophic epidermolysis bullosa keratinocytes (RDEBK-TA4), the DSP exhibited high transfection efficacy with both Gaussia luciferase marker DNA and the full length COL7A1 transcript encoding the therapeutic type VII collagen protein (C7). The effective restoration of C7 in C7 null-RDEB skin cells indicates that DSP is promising for non-viral gene therapy of recessive dystrophic epidermolysis bullosa (RDEB). PMID:26369723

  3. Promoter structures and differential responses to viral and non-viral inducers of chicken melanoma differentiation-associated gene 5.

    PubMed

    Zhang, Wen-Xin; Zuo, Er-Wei; He, Ying; Chen, Dong-Yang; Long, Xie; Chen, Mei-Juan; Li, Ting-Ting; Yang, Xiao-Gan; Xu, Hui-Yan; Lu, Sheng-Sheng; Zhang, Ming; Lu, Ke-Huan; Lu, Yang-Qing

    2016-08-01

    Melanoma differentiation-associated gene 5 (MDA5) is a member of the retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs) family and plays a pivotal role in the anti-viral innate immune response. As RIG-I is absent in chickens, MDA5 is hypothesized to be important in detecting viral nucleic acids in the cytoplasm. However, the molecular mechanism of the regulation of chicken MDA5 (chMDA5) expression has yet to be fully elucidated. With this in mind, a ∼2.5kb chMDA5 gene promoter region was examined and PCR amplified to assess its role in immune response. A chMDA5 promoter reporter plasmid (piggybac-MDA5-DsRed) was constructed and transfected into DF-1 cells to establish a Piggybac-MDA5-DsRed cell line. The MDA5 promoter activity was extremely low under basal condition, but was dramatically increased when cells were stimulated with polyinosinic: polycytidylic acid (poly I:C), interferon beta (IFN-β) or Infectious Bursal Disease Virus (IBDV). The DsRed mRNA level represented the promoter activity and was remarkably increased, which matched the expression of endogenous MDA5. However, Infectious Bronchitis Virus (IBV) and Newcastle disease virus (NDV) failed to increase the MDA5 promoter activity and the expression of endogenous MDA5. The results indicated that the promoter and the Piggybac-MDA5-DsRed cell line could be utilized to determine whether a ligand regulates MDA5 expression. For the first time, this study provides a tool for testing chMDA5 expression and regulation. PMID:27327127

  4. Discovery of Cationic Polymers for Non-viral Gene Delivery using Combinatorial Approaches

    PubMed Central

    Barua, Sutapa; Ramos, James; Potta, Thrimoorthy; Taylor, David; Huang, Huang-Chiao; Montanez, Gabriela; Rege, Kaushal

    2015-01-01

    Gene therapy is an attractive treatment option for diseases of genetic origin, including several cancers and cardiovascular diseases. While viruses are effective vectors for delivering exogenous genes to cells, concerns related to insertional mutagenesis, immunogenicity, lack of tropism, decay and high production costs necessitate the discovery of non-viral methods. Significant efforts have been focused on cationic polymers as non-viral alternatives for gene delivery. Recent studies have employed combinatorial syntheses and parallel screening methods for enhancing the efficacy of gene delivery, biocompatibility of the delivery vehicle, and overcoming cellular level barriers as they relate to polymer-mediated transgene uptake, transport, transcription, and expression. This review summarizes and discusses recent advances in combinatorial syntheses and parallel screening of cationic polymer libraries for the discovery of efficient and safe gene delivery systems. PMID:21843141

  5. Manipulating gene expression in projection-specific neuronal populations using combinatorial viral approaches

    PubMed Central

    Gore, Bryan B.; Soden, Marta E.; Zweifel, Larry S.

    2013-01-01

    The mammalian brain contains tremendous structural and genetic complexity that is vital for its function. The elucidation of gene expression profiles in the brain, coupled with the development of large-scale connectivity maps and emerging viral vector-based approaches for target-selective gene manipulation, now allow for detailed dissection of gene-circuit interfaces. This protocol details how to perform combinatorial viral injections to manipulate gene expression in subsets of neurons interconnecting two brain regions. This method utilizes stereotaxic injection of a retrograde transducing CAV2-Cre virus into one brain region, combined with injection of a locally transducing Cre-dependent AAV virus into another brain region. This technique is widely applicable to the genetic dissection of neural circuitry, as it enables selective expression of candidate genes, dominant-negatives, fluorescent reporters, or genetic tools within heterogeneous populations of neurons based upon their projection targets. PMID:25429312

  6. Phosphorylation of Measles Virus Nucleoprotein Affects Viral Growth by Changing Gene Expression and Genomic RNA Stability

    PubMed Central

    Sugai, Akihiro; Sato, Hiroki; Yoneda, Misako

    2013-01-01

    The measles virus (MV) nucleoprotein associates with the viral RNA genome to form the N-RNA complex, providing a template for viral RNA synthesis. In our previous study, major phosphorylation sites of the nucleoprotein were identified as S479 and S510. However, the functions of these phosphorylation sites have not been clarified. In this study, we rescued recombinant MVs (rMVs) whose phosphorylation sites in the nucleoprotein were substituted (rMV-S479A, rMV-S510A, and rMV-S479A/S510A) by reverse genetics and used them in subsequent analyses. In a one-step growth experiment, rMVs showed rapid growth kinetics compared with wild-type MV, although the peak titer of the wild-type MV was the same as or slightly higher than those of the rMVs. Time course analysis of nucleoprotein accumulation also revealed that viral gene expression of rMV was enhanced during the early phase of infection. These findings suggest that nucleoprotein phosphorylation has an important role in controlling viral growth rate through the regulation of viral gene expression. Conversely, multistep growth curves revealed that nucleoprotein-phosphorylation intensity inversely correlated with viral titer at the plateau phase. Additionally, the phosphorylation intensity of the wild-type nucleoprotein in infected cells was significantly reduced through nucleoprotein-phosphoprotein binding. Excessive nucleoprotein-phosphorylation resulted in lower stability against RNase and faster turnover of viral genomic RNA. These results suggest that nucleoprotein-phosphorylation is also involved in viral genomic RNA stability. PMID:23966404

  7. Hepatitis B Virus X and Regulation of Viral Gene Expression.

    PubMed

    Slagle, Betty L; Bouchard, Michael J

    2016-03-01

    The efficient replication of hepatitis B virus (HBV) requires the HBV regulatory hepatitis B virus X (HBx) protein. The exact contributions of HBx are not fully understood, in part because of the limitations of the assays used for its study. When HBV replication is driven from a plasmid DNA, the contribution of HBx is modest. However, there is an absolute requirement for HBx in assays that recapitulate the infectious virus life cycle. There is much evidence that HBx can contribute directly to HBV replication by acting on viral promoters embedded within protein coding sequences. In addition, HBx may also contribute indirectly by modulating cellular pathways to benefit virus replication. Understanding the mechanism(s) of HBx action during virus replication may provide insight into novel ways to disrupt chronic HBV replication. PMID:26747833

  8. Herpesvirus Late Gene Expression: A Viral-Specific Pre-initiation Complex Is Key

    PubMed Central

    Gruffat, Henri; Marchione, Roberta; Manet, Evelyne

    2016-01-01

    During their productive cycle, herpesviruses exhibit a strictly regulated temporal cascade of gene expression that can be divided into three general stages: immediate-early (IE), early (E), and late (L). This expression program is the result of a complex interplay between viral and cellular factors at both the transcriptional and post-transcriptional levels, as well as structural differences within the promoter architecture for each of the three gene classes. Since the cellular enzyme RNA polymerase II (RNAP-II) is responsible for the transcription of herpesvirus genes, most viral promoters contain DNA motifs that are common with those of cellular genes, although promoter complexity decreases from immediate-early to late genes. Immediate-early and early promoters contain numerous cellular and viral cis-regulating sequences upstream of a TATA box, whereas late promoters differ significantly in that they lack cis-acting sequences upstream of the transcription start site (TSS). Moreover, in the case of the β- and γ-herpesviruses, a TATT box motif is frequently found in the position where the consensus TATA box of eukaryotic promoters usually localizes. The mechanisms of transcriptional regulation of the late viral gene promoters appear to be different between α-herpesviruses and the two other herpesvirus subfamilies (β and γ). In this review, we will compare the mechanisms of late gene transcriptional regulation between HSV-1, for which the viral IE transcription factors – especially ICP4 – play an essential role, and the two other subfamilies of herpesviruses, with a particular emphasis on EBV, which has recently been found to code for its own specific TATT-binding protein. PMID:27375590

  9. Viral vector tropism for supporting cells in the developing murine cochlea.

    PubMed

    Sheffield, Abraham M; Gubbels, Samuel P; Hildebrand, Michael S; Newton, Stephen S; Chiorini, John A; Di Pasquale, Giovanni; Smith, Richard J H

    2011-07-01

    Gene-based therapeutics are being developed as novel treatments for genetic hearing loss. One roadblock to effective gene therapy is the identification of vectors which will safely deliver therapeutics to targeted cells. The cellular heterogeneity that exists within the cochlea makes viral tropism a vital consideration for effective inner ear gene therapy. There are compelling reasons to identify a viral vector with tropism for organ of Corti supporting cells. Supporting cells are the primary expression site of connexin 26 gap junction proteins that are mutated in the most common form of congenital genetic deafness (DFNB1). Supporting cells are also primary targets for inducing hair cell regeneration. Since many genetic forms of deafness are congenital it is necessary to administer gene transfer-based therapeutics prior to the onset of significant hearing loss. We have used transuterine microinjection of the fetal murine otocyst to investigate viral tropism in the developing inner ear. For the first time we have characterized viral tropism for supporting cells following in utero delivery to their progenitors. We report the inner ear tropism and potential ototoxicity of three previously untested vectors: early-generation adenovirus (Ad5.CMV.GFP), advanced-generation adenovirus (Adf.11D) and bovine adeno-associated virus (BAAV.CMV.GFP). Adenovirus showed robust tropism for organ of Corti supporting cells throughout the cochlea but induced increased ABR thresholds indicating ototoxicity. BAAV also showed tropism for organ of Corti supporting cells, with preferential transduction toward the cochlear apex. Additionally, BAAV readily transduced spiral ganglion neurons. Importantly, the BAAV-injected ears exhibited normal hearing at 5 weeks of age when compared to non-injected ears. Our results support the use of BAAV for safe and efficient targeting of supporting cell progenitors in the developing murine inner ear. PMID:21530627

  10. Cotton Leaf Curl Multan Virus-Derived Viral Small RNAs Can Target Cotton Genes to Promote Viral Infection.

    PubMed

    Wang, Jinyan; Tang, Yafei; Yang, Yuwen; Ma, Na; Ling, Xitie; Kan, Jialiang; He, Zifu; Zhang, Baolong

    2016-01-01

    RNA silencing is a conserved mechanism in plants that targets viruses. Viral small RNAs (vsiRNAs) can be generated from viral double-stranded RNA replicative intermediates within the infected host, or from host RNA-dependent RNA polymerases activity on viral templates. The abundance and profile of vsiRNAs in viral infections have been reported previously. However, the involvement of vsiRNAs during infection of the Geminiviridae family member cotton leaf curl virus (CLCuD), which causes significant economic losses in cotton growing regions, remains largely uncharacterized. Cotton leaf curl Multan virus (CLCuMuV) associated with a betasatellite called Cotton leaf curl Multan betasatellite (CLCuMuB) is a major constraint to cotton production in South Asia and is now established in Southern China. In this study, we obtained the profiles of vsiRNAs from CLCuMV and CLCuMB in infected upland cotton (Gossypium hirsutum) plants by deep sequencing. Our data showed that vsiRNA that were derived almost equally from sense and antisense CLCuD DNA strands accumulated preferentially as 21- and 22-nucleotide (nt) small RNA population and had a cytosine bias at the 5'-terminus. Polarity distribution revealed that vsiRNAs were almost continuously present along the CLCuD genome and hotspots of sense and antisense strands were mainly distributed in the Rep proteins region of CLCuMuV and in the C1 protein of CLCuMuB. In addition, hundreds of host transcripts targeted by vsiRNAs were predicted, many of which encode transcription factors associated with biotic and abiotic stresses. Quantitative real-time polymerase chain reaction analysis of selected potential vsiRNA targets showed that some targets were significantly down-regulated in CLCuD-infected cotton plants. We also verified the potential function of vsiRNA targets that may be involved in CLCuD infection by virus-induced gene silencing (VIGS) and 5'-rapid amplification of cDNA end (5'-RACE). Here, we provide the first report on vsi

  11. Cotton Leaf Curl Multan Virus-Derived Viral Small RNAs Can Target Cotton Genes to Promote Viral Infection

    PubMed Central

    Wang, Jinyan; Tang, Yafei; Yang, Yuwen; Ma, Na; Ling, Xitie; Kan, Jialiang; He, Zifu; Zhang, Baolong

    2016-01-01

    RNA silencing is a conserved mechanism in plants that targets viruses. Viral small RNAs (vsiRNAs) can be generated from viral double-stranded RNA replicative intermediates within the infected host, or from host RNA-dependent RNA polymerases activity on viral templates. The abundance and profile of vsiRNAs in viral infections have been reported previously. However, the involvement of vsiRNAs during infection of the Geminiviridae family member cotton leaf curl virus (CLCuD), which causes significant economic losses in cotton growing regions, remains largely uncharacterized. Cotton leaf curl Multan virus (CLCuMuV) associated with a betasatellite called Cotton leaf curl Multan betasatellite (CLCuMuB) is a major constraint to cotton production in South Asia and is now established in Southern China. In this study, we obtained the profiles of vsiRNAs from CLCuMV and CLCuMB in infected upland cotton (Gossypium hirsutum) plants by deep sequencing. Our data showed that vsiRNA that were derived almost equally from sense and antisense CLCuD DNA strands accumulated preferentially as 21- and 22-nucleotide (nt) small RNA population and had a cytosine bias at the 5′-terminus. Polarity distribution revealed that vsiRNAs were almost continuously present along the CLCuD genome and hotspots of sense and antisense strands were mainly distributed in the Rep proteins region of CLCuMuV and in the C1 protein of CLCuMuB. In addition, hundreds of host transcripts targeted by vsiRNAs were predicted, many of which encode transcription factors associated with biotic and abiotic stresses. Quantitative real-time polymerase chain reaction analysis of selected potential vsiRNA targets showed that some targets were significantly down-regulated in CLCuD-infected cotton plants. We also verified the potential function of vsiRNA targets that may be involved in CLCuD infection by virus-induced gene silencing (VIGS) and 5′-rapid amplification of cDNA end (5′-RACE). Here, we provide the first report

  12. Control of Rta expression critically determines transcription of viral and cellular genes following gammaherpesvirus infection.

    PubMed

    Hair, James R; Lyons, Paul A; Smith, Kenneth G C; Efstathiou, Stacey

    2007-06-01

    The replication and transcriptional activator (Rta), encoded by ORF50 of gammaherpesviruses, initiates the lytic cycle of gene expression; therefore understanding the impact of Rta on viral and cellular gene expression is key to elucidating the transcriptional events governing productive infection and reactivation from latency. To this end, the impact of altering Rta transcription on viral and cellular gene expression was studied in the context of a whole virus infection. Recombinant murine gammaherpesvirus (MHV)-68 engineered to overexpress Rta greatly accelerated expression of specific lytic cycle ORFs, but repressed transcription of the major latency gene, ORF73. Increased expression of Rta accelerated the dysregulation in transcription of specific cellular genes when compared with cells infected with wild-type and revertant viruses. A subset of cellular genes was dysregulated only in cells infected with Rta-overexpressing virus, and never in those infected with non-overexpressing viruses. These data highlight the critical role of Rta abundance in governing viral and cellular gene transcription, and demonstrate the importance of understanding how the relative expression of ORF50 during the virus life cycle impacts on these processes. PMID:17485528

  13. Control of Rta expression critically determines transcription of viral and cellular genes following gammaherpesvirus infection

    PubMed Central

    Hair, James R.; Lyons, Paul A.; Smith, Kenneth G. C.; Efstathiou, Stacey

    2007-01-01

    The replication and transcriptional activator (Rta), encoded by ORF50 of gammaherpesviruses, initiates the lytic cycle of gene expression; therefore understanding the impact of Rta on viral and cellular gene expression is key to elucidating the transcriptional events governing productive infection and reactivation from latency. To this end, the impact of altering Rta transcription on viral and cellular gene expression was studied in the context of a whole virus infection. Recombinant murine gammaherpesvirus (MHV)-68 engineered to overexpress Rta greatly accelerated expression of specific lytic cycle ORFs, but repressed transcription of the major latency gene, ORF73. Increased expression of Rta accelerated the dysregulation in transcription of specific cellular genes when compared with cells infected with wild-type and revertant viruses. A subset of cellular genes was dysregulated only in cells infected with Rta-overexpressing virus, and never in those infected with non-overexpressing viruses. These data highlight the critical role of Rta abundance in governing viral and cellular gene transcription, and demonstrate the importance of understanding how the relative expression of ORF50 during the virus life cycle impacts on these processes. PMID:17485528

  14. Progress in the development of lipopolyplexes as efficient non-viral gene delivery systems.

    PubMed

    Rezaee, Mehdi; Oskuee, Reza Kazemi; Nassirli, Hooriyeh; Malaekeh-Nikouei, Bizhan

    2016-08-28

    Efficient gene therapy is mainly dependent on the gene transfer capability of gene delivery vectors. Non-viral vectors have become the research interest of many researchers because these vectors are safer than viral vectors. Acquiring the advantages of both polyplexes and lipoplexes, the lipopolyplex (LPP) is a ternary nanocomplex composed of cationic liposome, polycation, and nucleic acid. Considering the polycationic component, ternary complexes (LPPs) are divided into cationic polymer-based LPPs and cationic peptide-based LPPs. Considering the capability of rational design, LPP is an interesting field of research to design a more potent nucleic acid carrier. With the promising transfection activity and safety observed in the LPPs, many researchers have formulated various types of lipids and polycations to achieve an efficient and safe carrier for gene therapy. Here we provide a review on the designed LPPs for efficient delivery of different nucleic acids such as plasmid DNA, siRNA, shRNA, and DNA vaccines. PMID:27317365

  15. Aggregation of AcMNPV LEF-10 and Its Impact on Viral Late Gene Expression

    PubMed Central

    Xu, Xiaodong; Zhou, Xinyu; Nan, Hao; Zhao, Yu; Bai, Yu; Ou, Yanmei; Chen, Hongying

    2016-01-01

    The Autographa californica multiple nucleopolyhedrovirus (AcMNPV) late expression factor gene lef-10 has been identified to be required for viral late gene expression by transient expression assay. Our previous work has shown that the gene product LEF-10 can form very stable high-molecular-weight complexes, but the structure and function of the protein remain unknown. In this study, we demonstrated that LEF-10 was essential for the replication of AcMNPV, and its truncated fragment containing amino acid residues 1 to 48 were sufficient to support the virus survival. Our data also suggested that the LEF-10 could spontaneously aggregate to form punctate spots in virus infected Sf9 cells at low frequency, and the aggregation of the protein could be induced by LEF-10 over-expression. When the protein aggregated to form punctate spots, soluble LEF-10 proteins were depleted and this could result in the down-regulation of viral late gene expression. PMID:27152613

  16. Antitumor activity and inhibitory effects on cancer stem cell-like properties of Adeno-associated virus (AAV) -mediated Bmi-1 interference driven by Bmi-1 promoter for gastric cancer

    PubMed Central

    Wang, Xiaofeng; Liu, Xinyang; Huang, Mingzhu; Gan, Lu; Cheng, Yufan; Li, Jin

    2016-01-01

    Bmi-1 is aberrantly activated in various cancers and plays a vital role in maintaining the self-renewal of stem cells. Our previous research revealed that Bmi-1 was overexpressed in gastric cancer (GC) and it's overexpression was an independent negative prognostic factor, suggesting it can be a therapeutic target. The main purpose of this investigation was to explore the antitumor activity of Bmi-1 interference driven by its own promoter (Ad-Bmi-1i) for GC. In this study, we used adenoviral vector to deliver Bmi-1 shRNA driven by its own promoter to treat GC. Our results revealed that Ad-Bmi-1i could selectively silence Bmi-1 in GC cells which overexpress Bmi-1 and suppress the malignant phenotypes and stem-like properties of GC cells in vitro and in vivo. Moreover, direct injection of Ad-Bmi-1i into xenografts suppressed tumor growth and destroyed cancer cells in vivo. Ad-Bmi-1i inhibited the proliferation of GC cells mainly via inducing senescence in vitro, but it suppressed tumor through inducing senescence and apoptosis, and inhibiting angiogenesis in vivo. Bmi-1 knockdown by Ad-Bmi-1i downregulated VEGF via inhibiting AKT activity. These results suggest that Ad-Bmi-1i not only inhibits tumor growth and stem cell-like phenotype by inducing cellular senescence directly, but also has an indirect anti-tumor activity by anti-angiogenesis effects via regulating PTEN/AKT/VEGF pathway. Transfer of gene interference guided by its own promoter by an adeno-associated virus (AAV) vector might be a potent antitumor approach for cancer therapy. PMID:27009837

  17. Benefits of Recombinant Adeno-Associated Virus (rAAV)-Mediated Insulinlike Growth Factor I (IGF-I) Overexpression for the Long-Term Reconstruction of Human Osteoarthritic Cartilage by Modulation of the IGF-I Axis

    PubMed Central

    Weimer, Anja; Madry, Henning; Venkatesan, Jagadeesh K; Schmitt, Gertrud; Frisch, Janina; Wezel, Anna; Jung, Jochen; Kohn, Dieter; Terwilliger, Ernest F; Trippel, Stephen B; Cucchiarini, Magali

    2012-01-01

    Administration of therapeutic genes to human osteoarthritic (OA) cartilage is a potential approach to generate effective, durable treatments against this slow, progressive disorder. Here, we tested the ability of recombinant adeno-associated virus (rAAV)-mediated overexpression of human insulinlike growth factor (hIGF)-I to reproduce an original surface in human OA cartilage in light of the pleiotropic activities of the factor. We examined the proliferative, survival and anabolic effects of the rAAV-hIGF-I treatment in primary human normal and OA chondrocytes in vitro and in explant cultures in situ compared with control (reporter) vector delivery. Efficient, prolonged IGF-I secretion via rAAV stimulated the biological activities of OA chondrocytes in all the systems evaluated over extended periods of time, especially in situ, where it allowed for the long-term reconstruction of OA cartilage (at least for 90 d). Remarkably, production of high, stable amounts of IGF-I in OA cartilage using rAAV advantageously modulated the expression of central effectors of the IGF-I axis by downregulating IGF-I inhibitors (IGF binding protein [IGFBP]-3 and IGFBP4) while up-regulating key potentiators (IGFBP5, the IGF-I receptor and downstream mitogen-activated protein kinase/extracellular signal–regulated kinase 1/2 [MAPK/ERK-1/2] and phosphatidylinisitol-3/Akt [PI3K/Akt] signal transduction pathways), probably explaining the enhanced responsiveness of OA cartilage to IGF-I treatment. These findings show the benefits of directly providing an IGF-I sequence to articular cartilage via rAAV for the future treatment of human osteoarthritis. PMID:22160392

  18. Identification of a herpes simplex virus function that represses late gene expression from parental viral genomes.

    PubMed Central

    Godowski, P J; Knipe, D M

    1985-01-01

    The expression of herpes simplex virus gamma 2 (late) genes is inhibited before the onset of viral DNA replication. We report that the block in the expression of certain gamma 2 genes is relieved, at least in part, by defects in the beta ICP8 protein. We have examined the expression of the gamma 2 gene encoding glycoprotein C (gC) in cells infected with a temperature-sensitive ICP8 mutant. Under conditions in which viral DNA replication is inhibited, cells infected with the ICP8 mutant overproduce the gC family of mRNAs relative to the level observed in cells infected with a wild-type virus. The gC mRNA synthesized in cells infected with the ICP8 mutant virus is correctly initiated and spliced and is translated with the same relative efficiency as in cells infected with a replicating wild-type virus. These results suggest that ICP8 is involved in the negative regulation of gamma 2 genes expressed from parental viral genomes. The level of gC expression was greatest in cells infected with a replicating wild-type virus. These data suggest that DNA replication and genome amplification are not absolute requirements for gamma 2 gene expression but may facilitate full-level expression of these genes. Images PMID:2991561

  19. Virally-expressed connexin26 restores gap junction function in the cochlea of conditional Gjb2 knockout mice

    PubMed Central

    Yu, Qing; Wang, Yunfeng; Chang, Qing; Wang, Jianjun; Gong, Shushen; Li, Huawei; Lin, Xi

    2013-01-01

    Mutations in GJB2, which codes for the gap junction protein connexin26, are the most common causes of human nonsyndromic hereditary deafness. We inoculated modified adeno-associated viral vectors into the scala media of early postnatal conditional Gjb2 knockout mice to drive exogenous connexin26 expression. We found extensive virally-expressed connexin26 in cells lining the scala media, and intercellular gap junction network was re-established in the organ of Corti of mutant mouse cochlea. Widespread ectopic connexin26 expression neither formed ectopic gap junctions nor affected normal hearing thresholds in wild type mice, suggesting that autonomous cellular mechanisms regulate proper membrane trafficking of exogenously-expressed connexin26 and govern the functional manifestation of them. Functional recovery of gap-junction-mediated coupling among the supporting cells was observed. We found that both cell death in the organ of Corti and degeneration of spiral ganglion neurons in the cochlea of mutant mice were substantially reduced, although auditory brainstem responses did not show significant hearing improvement. This is the first report demonstrating that virally-mediated gene therapy restored extensive gap junction intercellular network among cochlear non-sensory cells in vivo. Such a treatment performed at early postnatal stages resulted in a partial rescue of disease phenotypes in the cochlea of the mutant mice. PMID:24225640

  20. Drosophila germline invasion by the endogenous retrovirus gypsy: involvement of the viral env gene.

    PubMed

    Pelisson, A; Mejlumian, L; Robert, V; Terzian, C; Bucheton, A

    2002-10-01

    The endogenous retrovirus gypsy is expressed at high levels in mutant flamenco female flies. Gypsy viral particles extracted from such flies can infect naive flamenco individuals raised in the presence of these extracts mixed into their food. This results in the integration of new proviruses into the germline genome. These proviruses can then increase their copy number by (1) expression in the flamenco female somatic cells, (2) transfer into the oocyte and (3) integration into the genome of the progeny. Surprisingly, unlike the infection observed in the feeding experiments, this strategy of endogenous proviral multiplication does not seem to involve the expression of the viral env gene. PMID:12225916

  1. Extensive Gene Remodeling in the Viral World: New Evidence for Nongradual Evolution in the Mobilome Network

    PubMed Central

    Jachiet, Pierre-Alain; Colson, Philippe; Lopez, Philippe; Bapteste, Eric

    2014-01-01

    Complex nongradual evolutionary processes such as gene remodeling are difficult to model, to visualize, and to investigate systematically. Despite these challenges, the creation of composite (or mosaic) genes by combination of genetic segments from unrelated gene families was established as an important adaptive phenomena in eukaryotic genomes. In contrast, almost no general studies have been conducted to quantify composite genes in viruses. Although viral genome mosaicism has been well-described, the extent of gene mosaicism and its rules of emergence remain largely unexplored. Applying methods from graph theory to inclusive similarity networks, and using data from more than 3,000 complete viral genomes, we provide the first demonstration that composite genes in viruses are 1) functionally biased, 2) involved in key aspects of the arm race between cells and viruses, and 3) can be classified into two distinct types of composite genes in all viral classes. Beyond the quantification of the widespread recombination of genes among different viruses of the same class, we also report a striking sharing of genetic information between viruses of different classes and with different nucleic acid types. This latter discovery provides novel evidence for the existence of a large and complex mobilome network, which appears partly bound by the sharing of genetic information and by the formation of composite genes between mobile entities with different genetic material. Considering that there are around 10E31 viruses on the planet, gene remodeling appears as a hugely significant way of generating and moving novel sequences between different kinds of organisms on Earth. PMID:25104113

  2. Interaction between ORF24 and ORF34 in the Kaposi's Sarcoma-Associated Herpesvirus Late Gene Transcription Factor Complex Is Essential for Viral Late Gene Expression

    PubMed Central

    Davis, Zoe H.; Hesser, Charles R.; Park, Jimin

    2015-01-01

    Transcription of herpesviral late genes is stimulated after the onset of viral DNA replication but otherwise restricted. Late gene expression in gammaherpesviruses requires the coordination of six early viral proteins, termed viral transactivation factors (vTFs). Here, we mapped the organization of this protein complex for Kaposi's sarcoma-associated herpesvirus. Disruption of this complex via point mutation of the interaction interface between the open reading frame 24 (ORF24) and ORF34 vTFs ablated both late gene expression and viral replication. PMID:26468530

  3. Viral-mediated Ntf3 overexpression disrupts innervation and hearing in nondeafened guinea pig cochleae

    PubMed Central

    Lee, Min Young; Kurioka, Takaomi; Nelson, Megan M; Prieskorn, Diane M; Swiderski, Donald L; Takada, Yohei; Beyer, Lisa A; Raphael, Yehoash

    2016-01-01

    Synaptopathy in the cochlea occurs when the connection between inner hair cells and the auditory nerve is disrupted, leading to impaired hearing and nerve degeneration. Experiments using transgenic mice have shown that overexpression of NT3 by supporting cells repairs synaptopathy caused by overstimulation. To accomplish such therapy in the clinical setting, it would be necessary to activate the neurotrophin receptor on auditory neurons by other means. Here we test the outcome of NT3 overexpression using viral-mediated gene transfer into the perilymph versus the endolymph of the normal guinea pig cochlea. We inoculated two different Ntf3 viral vectors, adenovirus (Adv) or adeno-associated virus (AAV) into the perilymph, to facilitate transgene expression in the mesothelial cells and cochlear duct epithelium, respectively. We assessed outcomes by comparing Auditory brainstem response (ABR) thresholds prior to that at baseline to thresholds at 1 and 3 weeks after inoculation, and then performed histologic evaluation of hair cells, nerve endings, and synaptic ribbons. We observed hearing threshold shifts as well as disorganization of peripheral nerve endings and disruption of synaptic connections between inner hair cells and peripheral nerve endings with both vectors. The data suggest that elevation of NT3 levels in the cochlear fluids can disrupt innervation and degrade hearing. PMID:27525291

  4. Viral-mediated Ntf3 overexpression disrupts innervation and hearing in nondeafened guinea pig cochleae.

    PubMed

    Lee, Min Young; Kurioka, Takaomi; Nelson, Megan M; Prieskorn, Diane M; Swiderski, Donald L; Takada, Yohei; Beyer, Lisa A; Raphael, Yehoash

    2016-01-01

    Synaptopathy in the cochlea occurs when the connection between inner hair cells and the auditory nerve is disrupted, leading to impaired hearing and nerve degeneration. Experiments using transgenic mice have shown that overexpression of NT3 by supporting cells repairs synaptopathy caused by overstimulation. To accomplish such therapy in the clinical setting, it would be necessary to activate the neurotrophin receptor on auditory neurons by other means. Here we test the outcome of NT3 overexpression using viral-mediated gene transfer into the perilymph versus the endolymph of the normal guinea pig cochlea. We inoculated two different Ntf3 viral vectors, adenovirus (Adv) or adeno-associated virus (AAV) into the perilymph, to facilitate transgene expression in the mesothelial cells and cochlear duct epithelium, respectively. We assessed outcomes by comparing Auditory brainstem response (ABR) thresholds prior to that at baseline to thresholds at 1 and 3 weeks after inoculation, and then performed histologic evaluation of hair cells, nerve endings, and synaptic ribbons. We observed hearing threshold shifts as well as disorganization of peripheral nerve endings and disruption of synaptic connections between inner hair cells and peripheral nerve endings with both vectors. The data suggest that elevation of NT3 levels in the cochlear fluids can disrupt innervation and degrade hearing. PMID:27525291

  5. [Non-viral gene therapy approach for regenerative recovery of skin wounds in mammals].

    PubMed

    Efremov, A M; Dukhovlinov, I V; Dizhe, E B; Burov, S V; Leko, M V; Akif'ev, B N; Mogilenko, D A; Ivanov, I A; Perevozchikov, A P; Orlov, S V

    2010-01-01

    The rate and character of skin tissue regeneration after wounds, burns and other traumas depend on the cell proliferation within damaged area. Acceleration of healing by stimulation of cell proliferation and extracellular matrix synthesis is one of the most important tasks of modern medicine. There are gene therapy approaches to wound treatment consisting in the transfer of genes encoding mitogenic growth factors to wound area. The most important step in the development of gene therapy approaches is the design of gene delivery tools. In spite of high efficacy of viral vectors, the non-viral means have some preferences (low toxicity, low immunogenity, safety and the absence of backside effects). Among non-viral gene delivery tools, molecular conjugates are the most popular because of their efficacy, simplicity, and the capacity to the targeted gene transfer. In the present work we have developed two molecular conjugates--NLS-TSF7 and NLS-TSF12 consisting of the modified signal of nuclear localization of T-antigen of SV40 virus (cationic part) and the peptide ligands of mammalian transferrin receptor (ligand part). These conjugates bind to plasmid DNA with formation of polyelectrolytic complexes and are capable to deliver plasmid DNA into cells expressing transferrin receptors by receptor-mediated endocytosis. Transfer of the expression vector of luciferase gene in the complex with molecular conjugate NLS-TSF7 to murine surface tissues led to about 100 fold increasing of luciferase activity in comparison with the transfer of free expression vector. Treatment of slash wounds in mice with the complexes of expression vector of synthetic human gene encoding insulin-like growth factor 1 with molecular conjugates NLS-TSF7 led to acceleration of healing in comparison with mice treated with free expression vector. The results obtained confirm the high efficiency of the developed regenerative gene therapy approach for the treatment of damaged skin tissues in mammals. PMID

  6. Peripheral challenge with a viral mimic upregulates expression of the complement genes in the hippocampus.

    PubMed

    Michalovicz, Lindsay T; Lally, Brent; Konat, Gregory W

    2015-08-15

    Peripheral challenge with a viral mimetic, polyinosinic-polycytidylic acid (PIC) induces hippocampal hyperexcitability in mice. Here, we characterized this hippocampal response through a whole genome transcriptome analysis. Intraperitoneal injection of PIC resulted in temporal dysregulation of 625 genes in the hippocampus, indicating an extensive genetic reprogramming. The bioinformatics analysis of these genes revealed the complement pathway to be the most significantly activated. The gene encoding complement factor B (CfB) exhibited the highest response, and its upregulation was commensurate with the development of hyperexcitability. Collectively, these results suggest that the induction of hippocampal hyperexcitability may be mediated by the alternative complement cascades. PMID:26198930

  7. Analysis of adeno-associated virus (AAV) wild-type and mutant Rep proteins for their abilities to negatively regulate AAV p5 and p19 mRNA levels.

    PubMed Central

    Kyöstiö, S R; Owens, R A; Weitzman, M D; Antoni, B A; Chejanovsky, N; Carter, B J

    1994-01-01

    The rep gene of adeno-associated virus type 2 (AAV) encodes four overlapping Rep proteins that are involved in gene regulation and replication of the virus. We studied here the regulation of mRNA transcribed from the AAV p5 and p19 promoters, using transient expression in human 293 cells followed by Northern (RNA) blot analysis of the mRNA. The p5 transcript encodes the larger Rep proteins, Rep78 and Rep68, while the p19 transcript encodes the smaller proteins, Rep52 and Rep40. A plasmid (pNTC3) containing the entire AAV genome with an amber mutation in the rep gene accumulated higher levels of p5 and p19 mRNA than a plasmid containing the wild-type AAV genome. Addition of increasing amounts of the wild-type rep gene in trans from a heterologous promoter inhibited p5 and p19 mRNA accumulation from pNTC3, indicating that the levels of both transcripts were decreased by the Rep proteins. Cotransfections with plasmids producing individual wild-type Rep proteins in trans showed that p5 and p19 mRNA accumulation was inhibited 5- to 10-fold by Rep78 and Rep68 and 2- to 3-fold by Rep52 and Rep40. Analysis of carboxyl-terminal truncation mutants of Rep78 showed that the ability of Rep78 to decrease p5 and p19 mRNA levels was lost when 159 or more amino acids were deleted. Rep78 and Rep68 mutants deleted for the methionine at residue 225 showed decreased abilities to down-regulate both p5 and p19 transcript levels, while mutants containing a substitution of glycine for the methionine resembled the wild-type Rep78. A Rep78 protein with a mutation in the putative nucleoside triphosphate binding site inhibited expression from p5 but not from p19, suggesting that the regulation of p5 transcript levels by Rep78 and Rep68 differs from that of p19. A deletion analysis of AAV cis sequences revealed that an intact terminal repeat was not required for negative regulation of p5 and p19 transcript levels and that the regulation of p19 mRNA levels by Rep78 did not require the presence

  8. A brain microvasculature endothelial cell-specific viral vector with the potential to treat neurovascular and neurological diseases.

    PubMed

    Körbelin, Jakob; Dogbevia, Godwin; Michelfelder, Stefan; Ridder, Dirk A; Hunger, Agnes; Wenzel, Jan; Seismann, Henning; Lampe, Melanie; Bannach, Jacqueline; Pasparakis, Manolis; Kleinschmidt, Jürgen A; Schwaninger, Markus; Trepel, Martin

    2016-01-01

    Gene therapy critically relies on vectors that combine high transduction efficiency with a high degree of target specificity and that can be administered through a safe intravenous route. The lack of suitable vectors, especially for gene therapy of brain disorders, represents a major obstacle. Therefore, we applied an in vivo screening system of random ligand libraries displayed on adeno-associated viral capsids to select brain-targeted vectors for the treatment of neurovascular diseases. We identified a capsid variant showing an unprecedented degree of specificity and long-lasting transduction efficiency for brain microvasculature endothelial cells as the primary target of selection. A therapeutic vector based on this selected viral capsid was used to markedly attenuate the severe cerebrovascular pathology of mice with incontinentia pigmenti after a single intravenous injection. Furthermore, the versatility of this selection system will make it possible to select ligands for additional in vivo targets without requiring previous identification of potential target-specific receptors. PMID:27137490

  9. Gene expression analysis during acute hepatitis C virus infection associates dendritic cell activation with viral clearance.

    PubMed

    Zabaleta, Aintzane; Riezu-Boj, Jose-Ignacio; Larrea, Esther; Villanueva, Lorea; Lasarte, Juan Jose; Guruceaga, Elizabeth; Fisicaro, Paola; Ezzikouri, Sayeh; Missale, Gabriele; Ferrari, Carlo; Benjelloun, Soumaya; Prieto, Jesús; Sarobe, Pablo

    2016-05-01

    Viral clearance during acute hepatitis C virus (HCV) infection is associated with the induction of potent antiviral T-cell responses. Since dendritic cells (DC) are essential in the activation of primary T-cell responses, gene expression was analyzed in DC from patients during acute HCV infection. By using microarrays, gene expression was compared in resting and activated peripheral blood plasmacytoid (pDC) and myeloid (mDC) DC from acute HCV resolving patients (AR) and from patients who become chronically infected (ANR), as well as in healthy individuals (CTRL) and chronically-infected patients (CHR). For pDC, a high number of upregulated genes was found in AR patients, irrespective of DC stimulation. However, for mDC, most evident differences were detected after DC stimulation, again corresponding to upregulated genes in AR patients. Divergent behavior of ANR was also observed when analyzing DC from CTRL and CHR, with ANR patients clustering again apart from these groups. These differences corresponded to metabolism-associated genes and genes belonging to pathways relevant for DC activation and cytokine responses. Thus, upregulation of relevant genes in DC during acute HCV infection may determine viral clearance, suggesting that dysfunctional DC may be responsible for the lack of efficient T-cell responses which lead to chronic HCV infection. PMID:26447929

  10. Expression of a cellular gene cloned in herpes simplex virus: rabbit beta-globin is regulated as an early viral gene in infected fibroblasts.

    PubMed Central

    Smiley, J R; Smibert, C; Everett, R D

    1987-01-01

    We constructed nondefective herpes simplex virus type 1 recombinants bearing the intact rabbit beta-globin gene inserted into the viral gene for thymidine kinase to study the expression of a cellular gene when it is present in the viral genome during lytic viral infections. The globin promoter was activated to high levels during productive infection of Vero cells, giving rise to properly spliced and processed cytoplasmic globin transcripts. Expression of globin RNA occurred with early kinetics, was not affected by blocking viral DNA replication, and was strongly inhibited by preventing viral immediate-early protein synthesis with cycloheximide. These results support the hypothesis that temporal control of herpes simplex virus early gene expression is accomplished by mechanisms that are not restricted to viral promoters. In addition, these data show that a cellular transcript can be correctly processed and can accumulate to high levels during viral infection; this indicates that the mechanisms of virally induced shutoff of host RNA accumulation and degradation of host mRNAs do not depend on sequence-specific differentiation between host and viral RNAs. These findings also suggest that herpesviruses have considerable potential as high-capacity gene transfer vectors for a variety of applications. Images PMID:3037101

  11. Recombinant adeno-associated virus-delivered anginex inhibits angiogenesis and growth of HUVECs by regulating the Akt, JNK and NF-κB signaling pathways.

    PubMed

    Ma, Ke; Wang, Chuying; Geng, Qianqian; Fan, Yangwei; Ning, Jing; Yang, Haixia; Dong, Xuyuan; Dong, Danfeng; Guo, Yuyan; Wei, Xin; Li, Enxiao; Wu, Yinying

    2016-06-01

    Anginex is an artificial synthetic small molecule β-sheet-forming peptide shown to have anti-angiogenesis and antitumor effects in various solid tumors. However, its molecular mechanism remains largely unclear and efficient delivery methods for anginex remains to be developed. We report on the development of recombinant adeno-associated virus (rAAV2)-delivered anginex and the underlying mechanism of anti-angiogenesis and antitumor effects of anginex. We have successfully developed the rAAV2 vector to efficiently express anginex (rAAV2‑anginex). Transduction of rAAV2-anginex significantly induced apoptosis, and inhibited the proliferation, migration, invasion and tube formation of human umbilical vein endothelial cells in vitro. Western blot analysis revealed that rAAV2‑anginex inhibited the phosphorylation of Akt, while inducing the phosphorylation of JNK and activation of the NF-κB signaling pathway. In an in vivo CAM assay and xenograft model of SKOV3, rAAV2-anginex significantly reduced microvessel density (MVD) and vascular endothelial growth factor 165 (VEGF165), as demonstrated by immunohistochemistry analysis. Importantly, rAAV2-anginex inhibited tumor growth in an ovarian cancer SKOV3 cell nude mouse xenograft model. Our results suggest that rAAV2-anginex may inhibit tumor angiogenesis and growth through regulating Akt, JNK and NF-κB signaling pathways. PMID:27035232

  12. Selective Cleavage of AAVS1 Substrates by the Adeno-Associated Virus Type 2 Rep68 Protein Is Dependent on Topological and Sequence Constraints

    PubMed Central

    Lamartina, Stefania; Ciliberto, Gennaro; Toniatti, Carlo

    2000-01-01

    The adeno-associated virus type 2 (AAV-2) Rep78 and Rep68 proteins are required for replication of the virus as well as its site-specific integration into a unique site, called AAVS1, of human chromosome 19. Rep78 and Rep68 initiate replication by binding to a Rep binding site (RBS) contained in the AAV-2 inverted terminal repeats (ITRs) and then specifically nicking at a nearby site called the terminal resolution site (trs). Similarly, Rep78 and Rep68 are postulated to trigger the integration process by binding and nicking RBS and trs homologues present in AAVS1. However, Rep78 and Rep68 cleave in vitro AAVS1 duplex-linear substrates much less efficiently than hairpinned ITRs. In this study, we show that the AAV-2 Rep68 endonuclease activity is affected by the topology of the substrates in that it efficiently cleaves in vitro in a site- and strand-specific manner the AAVS1 trs only if this sequence is in a supercoiled (SC) conformation. DNA sequence mutagenesis in the context of SC templates allowed us to elucidate for the first time the AAVS1 trs sequence and position requirements for Rep68-mediated cleavage. Interestingly, Rep68 did not cleave SC templates containing RBS from other sites of the human genome. These findings have intriguing implications for AAV-2 site-specific integration in vivo. PMID:10982325

  13. Adeno-associated virus type 2 rep protein inhibits human papillomavirus type 16 E2 recruitment of the transcriptional coactivator p300.

    PubMed

    Marcello, A; Massimi, P; Banks, L; Giacca, M

    2000-10-01

    Infection by human adeno-associated virus type 2 (AAV2) is a possible protective factor in the development of cervical carcinomas associated with human papillomaviruses (HPV). The replicative proteins of AAV2 (Rep) have been implicated in the inhibition of papillomavirus replication and transforming activities, although the molecular events underlying these effects are poorly understood. We observed that each of the four forms of AAV2 Rep inhibited the E1- and E2-driven replication of oncogenic HPV type 16 (HPV16). Rep40, corresponding to the C-terminal domain of all Rep proteins, inhibited both HPV DNA replication and HPV16 E2-mediated transactivation. Rep40 specifically bound the N-terminal transactivation domain of HPV16 E2 both in vitro and in vivo. This interaction was found to specifically disrupt the binding of E2 to the cellular transcriptional coactivator p300. Accordingly, the inhibitory effect of Rep on HPV16 E2 transactivation was rescued by the overexpression of p300. These data indicate a novel role of Rep in the down-regulation of papillomaviruses through inhibition of complex formation between the HPV16 E2 transcriptional activator and its cellular coactivator, p300. PMID:10982355

  14. Natural and genetically engineered viral agents for oncolysis and gene therapy of human cancers.

    PubMed

    Sinkovics, Joseph G; Horvath, Joseph C

    2008-12-01

    Based on personal acquaintances and experience dating back to the early 1950s, the senior author reviews the history of viral therapy of cancer. He points out the difficulties encountered in the treatment of human cancers, as opposed by the highly successful viral therapy of experimentally maintained tumors in laboratory animals, especially that of ascites carcinomas in mice. A detailed account of viral therapy of human tumors with naturally oncolytic viruses follows, emphasizing the first clinical trials with viral oncolysates. The discrepancy between the high success rates, culminating in cures, in the treatment of tumors of laboratory animals, and the moderate results, such as stabilizations of disease, partial responses, very rare complete remissions, and frequent relapses with virally treated human tumors is recognized. The preclinical laboratory testing against established human tumor cell lines that were maintained in tissue cultures for decades, and against human tumors extricated from their natural habitat and grown in xenografts, may not yield valid results predictive of the viral therapy applied against human tumors growing in their natural environment, the human host. Since the recent discovery of the oncosuppressive efficacy of bacteriophages, the colon could be regarded as the battlefield, where incipient tumor cells and bacteriophages vie for dominance. The inner environment of the colon will be the teaching ground providing new knowledge on the value of the anti-tumor efficacy of phage-induced innate anti-tumor immune reactions. Genetically engineered oncolytic viruses are reviewed next. The molecular biology of viral oncolysis is explained in details. Elaborate efforts are presented to elucidate how gene product proteins of oncolytic viruses switch off the oncogenic cascades of cancer cells. The facts strongly support the conclusion that viral therapy of human cancers will remain in the front lines of modern cancer therapeutics. It may be a

  15. Transposon-based vector systems for gene therapy clinical trials: challenges and considerations.

    PubMed

    Meir, Yaa-Jyuhn James; Wu, Sareina Chiung-Yuan

    2011-01-01

    Much progress has been made in gene therapy, but significant challenges remain. One is development of a range of different tools that can be used for different therapeutic purposes. Another is site-specific gene targeting for safe and faithful therapeutic gene expression. Viruses have long been considered the most promising tools for human gene therapy. However, fatal side effects associated with viral vectors have hampered their clinical application. DNA transposons, widely utilized for decades as genetic tools in plants and insects, are now emerging as viable vectors for gene therapy. In this article, we will give a brief review of the adverse effects associated with virus-based gene therapy followed by a glimpse of the adeno-associated virus vector system, which is currently the most promising viral vector for gene therapy. The development of DNA transposon-based gene delivery systems and the advantages and limits of the most commonly used DNA transposon systems, Sleeping Beauty, Tol2, and piggyBac, will be extensively discussed Finally, we will focus on the most promising transposon system for gene therapy, piggyBac. Challenges and considerations for advancing piggyBac for therapeutic application will be critically addressed. PMID:22196059

  16. Non-viral gene delivery for local and controlled DNA release.

    PubMed

    Trentin, Diana; Hubbell, Jeffrey; Hall, Heike

    2005-01-20

    Non-viral DNA delivery systems show important advantages vs. viral systems that are usually associated with an immunological response and safety risks. In this study, disulfide cross-linked peptide-DNA condensates were investigated for local gene delivery. Two different 21 amino acid peptides were designed to have a DNA binding sequence in combination with a transglutaminase substrate site or a nuclear localization site. The peptides were used in different ratios to each other to form stable cross-linked DNA-peptide condensates with a mean diameter of 164 nm and a size distribution from 43 to 204 nm. Such aggregates showed similar stability compared to condensates formed between DNA and high molecular weight poly-L-lysine (PLL). Peptide-DNA condensates were covalently immobilized into fibrin matrices by the activity of factor XIII and were used for gene delivery in vitro. After internalization, reduction of the cross-linked peptide-DNA condensates yielded increased transfection efficiencies into different cell types cultured in 2D sandwich assays, and comparable values for HUVECs cultured in a 3D fibrin matrix, as compared to PLL-DNA condensates. Cell viability 24 h after transfection remained above 95%. The target was to develop a transfection system based on small peptides that can be covalently cross-linked into fibrin-matrices where DNA-release takes place upon cellular degradation of the matrix. This approach provides an interesting tool in non-viral gene delivery. PMID:15653151

  17. Ionic α-Helical Polypeptides towards Non-Viral Gene Delivery

    PubMed Central

    Zhang, Rujing; Song, Ziyuan; Yin, Lichen; Zheng, Nan; Tang, Haoyu; Lu, Hua; Gabrielson, Nathan P.; Lin, Yao; Kim, Kyung; Cheng, Jianjun

    2014-01-01

    The advent of polymeric materials has significantly promoted the development and rapid growth of various technologies in biomedical applications, such as tissue engineering and controlled drug and gene delivery. Water-soluble polypeptides bearing functional side chains and adopting stable secondary structures are a new class of functional polymeric materials of potentially broad applications in medicine and biotechnology. In this article, we summarize our recent effort on the design and synthesis of the water-soluble α-helical ionic polypeptides originally developed in our laboratory and highlight their applications in cell membrane penetration and non-viral gene/siRNA delivery. PMID:25377262

  18. Regulation of viral gene expression by the herpes simplex virus 1UL24 protein (HSV-1UL24 inhibits accumulation of viral transcripts).

    PubMed

    Sanabria-Solano, Carolina; Gonzalez, Carmen Elena; Richerioux, Nicolas; Bertrand, Luc; Dridi, Slimane; Griffiths, Anthony; Langelier, Yves; Pearson, Angela

    2016-08-01

    UL24 is conserved among all Herpesviridae. In herpes simplex virus 1 (HSV-1), UL24 mutations lead to reduced viral titers both in cell culture and in vivo, and reduced pathogenicity. The human cytomegalovirus ortholog of UL24 has a gene regulatory function; however, it is not known whether other UL24 orthologs also affect gene expression. We discovered that in co-transfection experiments, expression of UL24 correlated with a reduction in the expression of several viral proteins and transcripts. Substitution mutations targeting conserved residues in UL24 impaired this function. Reduced transcript levels did not appear attributable to changes in mRNA stability. The UL24 ortholog of Herpes B virus exhibited a similar activity. An HSV-1 mutant that does not express UL24 produced more viral R1 and R2 transcripts than the wild type or rescue virus relative to the amount of viral DNA. These results reveal a new role for HSV-1UL24 in regulating viral mRNA accumulation. PMID:27214229

  19. Anti-metastatic effects of viral and non-viral mediated Nk4 delivery to tumours.

    PubMed

    Buhles, Alexandra; Collins, Sara A; van Pijkeren, Jan P; Rajendran, Simon; Miles, Michelle; O'Sullivan, Gerald C; O'Hanlon, Deirdre M; Tangney, Mark

    2009-01-01

    The most common cause of death of cancer sufferers is through the occurrence of metastases. The metastatic behaviour of tumour cells is regulated by extracellular growth factors such as hepatocyte growth factor (HGF), a ligand for the c-Met receptor tyrosine kinase, and aberrant expression/activation of the c-Met receptor is closely associated with metastatic progression. Nk4 (also known as Interleukin (IL)32b) is a competitive antagonist of the HGF c-Met system and inhibits c-Met signalling and tumour metastasis. Nk4 has an additional anti-angiogenic activity independent of its HGF-antagonist function. Angiogenesis-inhibitory as well as cancer-specific apoptosis inducing effects make the Nk4 sequence an attractive candidate for gene therapy of cancer. This study investigates the inhibition of tumour metastasis by gene therapy mediated production of Nk4 by the primary tumour. Optimal delivery of anti-cancer genes is vital in order to achieve the highest therapeutic responses. Non-viral plasmid delivery methods have the advantage of safety and ease of production, providing immediate transgene expression, albeit short-lived in most tumours. Sustained presence of anti-angiogenic molecules is preferable with anti-angiogenic therapies, and the long-term expression mediated by Adeno-associated Virus (AAV) might represent a more appropriate delivery in this respect. However, the incubation time required by AAV vectors to reach appropriate gene expression levels hampers efficacy in many fast-growing murine tumour models. Here, we describe murine trials assessing the effects of Nk4 on the spontaneously metastatic Lewis Lung Carcinoma (LLC) model when delivered to primary tumour via plasmid lipofection or AAV2 vector. Intratumoural AAV-Nk4 administration produced the highest therapeutic response with significant reduction in both primary tumour growth and incidence of lung metastases. Plasmid-mediated therapy also significantly reduced metastatic growth, but with moderate

  20. Additive effects of HLA alleles and innate immune genes determine viral outcome in HCV infection

    PubMed Central

    Fitzmaurice, Karen; Hurst, Jacob; Dring, Megan; Rauch, Andri; McLaren, Paul J; Günthard, Huldrych F; Gardiner, Clair; Klenerman, Paul

    2015-01-01

    Background Chronic HCV infection is a leading cause of liver-related morbidity globally. The innate and adaptive immune responses are thought to be important in determining viral outcomes. Polymorphisms associated with the IFNL3 (IL28B) gene are strongly associated with spontaneous clearance and treatment outcomes. Objective This study investigates the importance of HLA genes in the context of genetic variation associated with the innate immune genes IFNL3 and KIR2DS3. Design We assess the collective influence of HLA and innate immune genes on viral outcomes in an Irish cohort of women (n=319) who had been infected from a single source as well as a more heterogeneous cohort (Swiss Cohort, n=461). In the Irish cohort, a number of HLA alleles are associated with different outcomes, and the impact of IFNL3-linked polymorphisms is profound. Results Logistic regression was performed on data from the Irish cohort, and indicates that the HLA-A*03 (OR 0.36 (0.15 to 0.89), p=0.027) -B*27 (OR 0.12 (0.03 to 0.45), p=<0.001), -DRB1*01:01 (OR 0.2 (0.07 to 0.61), p=0.005), -DRB1*04:01 (OR 0.31 (0.12 to 0.85, p=0.02) and the CC IFNL3 rs12979860 genotypes (OR 0.1 (0.04 to 0.23), p<0.001) are significantly associated with viral clearance. Furthermore, DQB1*02:01 (OR 4.2 (2.04 to 8.66), p=0.008), KIR2DS3 (OR 4.36 (1.62 to 11.74), p=0.004) and the rs12979860 IFNL3 ‘T’ allele are associated with chronic infection. This study finds no interactive effect between IFNL3 and these Class I and II alleles in relation to viral clearance. There is a clear additive effect, however. Data from the Swiss cohort also confirms independent and additive effects of HLA Class I, II and IFNL3 genes in their prediction of viral outcome. Conclusions This data supports a critical role for the adaptive immune response in the control of HCV in concert with the innate immune response. PMID:24996883

  1. Inactivation of the Human Cytomegalovirus US20 Gene Hampers Productive Viral Replication in Endothelial Cells

    PubMed Central

    Cavaletto, Noemi; Luganini, Anna

    2015-01-01

    ABSTRACT The human cytomegalovirus (HCMV) US12 gene family includes a group of 10 contiguous genes (US12 to US21) encoding predicted seven-transmembrane-domain (7TMD) proteins that are nonessential for replication within cultured fibroblasts. Nevertheless, inactivation of some US12 family members affects virus replication in other cell types; e.g., deletion of US16 or US18 abrogates virus growth in endothelial and epithelial cells or in human gingival tissue, respectively, suggesting a role for some US12 proteins in HCMV cell tropism. Here, we provide evidence that another member, US20, impacts the ability of a clinical strain of HCMV to replicate in endothelial cells. Through the use of recombinant HCMV encoding tagged versions of the US20 protein, we investigated the expression pattern, localization, and topology of the US20-encoded protein (pUS20). We show that pUS20 is expressed as a partially glycosylated 7TMD protein which accumulates late in infection in endoplasmic reticulum-derived peripheral structures localized outside the cytoplasmic virus assembly compartment (cVAC). US20-deficient mutants generated in the TR clinical strain of HCMV exhibited major growth defects in different types of endothelial cells, whereas they replicated normally in fibroblasts and epithelial cells. While the attachment and entry phases in endothelial cells were not significantly affected by the absence of US20 protein, US20-null viruses failed to replicate viral DNA and express representative E and L mRNAs and proteins. Taken together, these results indicate that US20 sustains the HCMV replication cycle at a stage subsequent to entry but prior to E gene expression and viral DNA synthesis in endothelial cells. IMPORTANCE Human cytomegalovirus (HCMV) is a major pathogen in newborns and immunocompromised individuals. A hallmark of HCMV pathogenesis is its ability to productively replicate in an exceptionally broad range of target cells, including endothelial cells, which represent

  2. Progress in gene and cell therapy for cystic fibrosis lung disease.

    PubMed

    Griesenbach, Uta; Alton, Eric W F W

    2012-01-01

    Although the development of gene therapy for cystic fibrosis (CF) was high priority for many groups in academia and industry in the first 10 to 15 years after cloning the gene, more recently active research into CF gene therapy is only being performed by a small number of committed, mainly academic, groups. However, despite the waning enthusiasm, which is largely due to the realisation that gene transfer into lungs is more difficult than originally thought and the fact that meaningful clinical trials are expensive and difficult to perform, gene therapy continues to hold promise for the treatment of CF lung disease. Problems related to repeat administration of adenovirus and adeno-associated virus-based vectors led to a focus on non-viral vectors in clinical trials. The UK CF Gene Therapy Consortium is currently running the only active gene therapy programme, aimed at assessing if repeated administration of a non-viral gene transfer agent can improve CF lung disease. However, the recent suggestion that lentiviral vectors may be able to evade the immune system and, thereby, allow for repeat administration and long lasting expression opens new doors for the use of viral vectors in the context of CF gene therapy. In addition, early pre-clinical studies have recently been initiated to address cell therapy-based approaches for CF. This involves systemic and topical administration of a variety of stem/progenitor cells, as well as first attempts as producing a tissue-engineered lung. Recent studies in viral and non-viral vector developments, as well as cell therapy will be discussed and an update on clinical gene therapy studies will be provided here. PMID:22229571

  3. Correction of glycogen storage disease type II by an adeno-associated virus vector containing a muscle-specific promoter.

    PubMed

    Sun, Baodong; Zhang, Haoyue; Franco, Luis M; Brown, Talmage; Bird, Andrew; Schneider, Ayn; Koeberl, Dwight D

    2005-06-01

    Glycogen storage disease type II (Pompe disease) causes death in infancy from cardiorespiratory failure due to acid alpha-glucosidase (GAA; acid maltase) deficiency. An AAV2 vector pseudotyped as AAV6 (AAV2/6 vector) transiently expressed high-level human GAA in GAA-knockout (GAA-KO) mice without reducing glycogen storage; however, in immunodeficient GAA-KO/SCID mice the AAV2/6 vector expressed high-level GAA and reduced the glycogen content of the injected muscle for 24 weeks. A CD4+/CD8+ lymphocytic infiltrate was observed in response to the AAV2/6 vector in immunocompetent GAA-KO mice. When a muscle-specific creatine kinase promoter was substituted for the CB promoter (AAV-MCKhGAApA), that AAV2/6 vector expressed high-level GAA and reduced glycogen content in immunocompetent GAA-KO mice. Muscle-restricted expression of hGAA provoked only a humoral (not cellular) immune response. Intravenous administration of a high number of particles of AAV-MCKhGAApA as AAV2/7 reduced the glycogen content of the heart and skeletal muscle and corrected individual myofibers in immunocompetent GAA-KO mice 24 weeks postinjection. In summary, persistent correction of muscle glycogen content was achieved with an AAV vector containing a muscle-specific promoter in GAA-KO mice, and this approach should be considered for muscle-targeted gene therapy in Pompe disease. PMID:15922959

  4. Expression of Epstein-Barr virus genes in different cell types after microinjection of viral DNA.

    PubMed Central

    Graessmann, A; Wolf, H; Bornkamm, G W

    1980-01-01

    Gene expression of Epstein-Barr virus (EBV) was studied after microinjection of viral DNA into different types of cells. Raji TK- cells, known to express viral gene functions after superinfection with the EBV-P3HR-1 virus strain, were attached to plastic dishes by using anti-lymphocyte IgG, phytohemagglutinin, or concanavalin A as a ligand. It was difficult to inject DNA into the small and fragile Raji cells. After formation of polykaryons by cell fusion, microinjection became more efficient. At 24 hr after injection of P3HR-1 virus DNA, 90-100% of the injected cells expressed the early antigen complex as observed by immunofluorescence staining; 70-80% of the cells simultaneously incorported [3H]thymidine, indicating that thymidine kinase is expressed after injection of viral DNA. Additionally, synthesis of the virus capsid antigen was demonstrated in 20-30% of the recipient Raji cells. Human diploid fibroblasts, African green monkey kidney cells, and rat fibroblasts, which do not represent natural target cells for EBV, could also be induced to synthesis of early antigen complex by injection of P3HR-1 virus DNA. Images PMID:6244558

  5. Tyrosine-phosphorylation of AAV2 vectors and its consequences on viral intracellular trafficking and transgene expression

    SciTech Connect

    Zhong Li; Li Baozheng; Jayandharan, Giridhararao; Mah, Cathryn S.; Govindasamy, Lakshmanan; Agbandje-McKenna, Mavis; Herzog, Roland W.

    2008-11-25

    We have documented that epidermal growth factor receptor protein tyrosine kinase (EGFR-PTK) signaling negatively affects intracellular trafficking and transduction efficiency of recombinant adeno-associated virus 2 (AAV2) vectors. Specifically, inhibition of EGFR-PTK signaling leads to decreased ubiquitination of AAV2 capsid proteins, which in turn, facilitates viral nuclear transport by limiting proteasome-mediated degradation of AAV2 vectors. In the present studies, we observed that AAV capsids can indeed be phosphorylated at tyrosine residues by EGFR-PTK in in vitro phosphorylation assays and that phosphorylated AAV capsids retain their structural integrity. However, although phosphorylated AAV vectors enter cells as efficiently as their unphosphorylated counterparts, their transduction efficiency is significantly reduced. This reduction is not due to impaired viral second-strand DNA synthesis since transduction efficiency of both single-stranded AAV (ssAAV) and self-complementary AAV (scAAV) vectors is decreased by {approx} 68% and {approx} 74%, respectively. We also observed that intracellular trafficking of tyrosine-phosphorylated AAV vectors from cytoplasm to nucleus is significantly decreased, which results from ubiquitination of AAV capsids followed by proteasome-mediated degradation, although downstream consequences of capsid ubiquitination may also be affected by tyrosine-phosphorylation. These studies provide new insights into the role of tyrosine-phosphorylation of AAV capsids in various steps in the virus life cycle, which has implications in the optimal use of recombinant AAV vectors in human gene therapy.

  6. Non-viral gene delivery strategies for cancer therapy, tissue engineering and regenerative medicine

    NASA Astrophysics Data System (ADS)

    Bhise, Nupura S.

    Gene therapy involves the delivery of deoxyribonucleic acid (DNA) into cells to override or replace a malfunctioning gene for treating debilitating genetic diseases, including cancer and neurodegenerative diseases. In addition to its use as a therapeutic, it can also serve as a technology to enable regenerative medicine strategies. The central challenge of the gene therapy research arena is developing a safe and effective delivery agent. Since viral vectors have critical immunogenic and tumorogenic safety issues that limit their clinical use, recent efforts have focused on developing non-viral biomaterial based delivery vectors. Cationic polymers are an attractive class of gene delivery vectors due to their structural versatility, ease of synthesis, biodegradability, ability to self-complex into nanoparticles with negatively charged DNA, capacity to carry large cargo, cellular uptake and endosomal escape capacity. In this thesis, we hypothesized that developing a biomaterial library of poly(betaamino esters) (PBAE), a newer class of cationic polymers consisting of biodegradable ester groups, would allow investigating vector design parameters and formulating effective non-viral gene delivery strategies for cancer drug delivery, tissue engineering and stem cell engineering. Consequently, a high-throughput transfection assay was developed to screen the PBAE-based nanoparticles in hard to transfect fibroblast cell lines. To gain mechanistic insights into the nanoparticle formulation process, biophysical properties of the vectors were characterized in terms of molecular weight (MW), nanoparticle size, zeta potential and plasmid per particle count. We report a novel assay developed for quantifying the plasmid per nanoparticle count and studying its implications for co-delivery of multiple genes. The MW of the polymers ranged from 10 kDa to 100 kDa, nanoparticle size was about 150 run, zeta potential was about 30 mV in sodium acetate buffer (25 mM, pH 5) and 30 to 100

  7. ZCURVE_V: a new self-training system for recognizing protein-coding genes in viral and phage genomes

    PubMed Central

    Guo, Feng-Biao; Zhang, Chun-Ting

    2006-01-01

    Background It necessary to use highly accurate and statistics-based systems for viral and phage genome annotations. The GeneMark systems for gene-finding in virus and phage genomes suffer from some basic drawbacks. This paper puts forward an alternative approach for viral and phage gene-finding to improve the quality of annotations, particularly for newly sequenced genomes. Results The new system ZCURVE_V has been run for 979 viral and 212 phage genomes, respectively, and satisfactory results are obtained. To have a fair comparison with the currently available software of similar function, GeneMark, a total of 30 viral genomes that have not been annotated by GeneMark are selected to be tested. Consequently, the average specificity of both systems is well matched, however the average sensitivity of ZCURVE_V for smaller viral genomes (< 100 kb), which constitute the main parts of viral genomes sequenced so far, is higher than that of GeneMark. Additionally, for the genome of Amsacta moorei entomopoxvirus, probably with the lowest genomic GC content among the sequenced organisms, the accuracy of ZCURVE_V is much better than that of GeneMark, because the later predicts hundreds of false-positive genes. ZCURVE_V is also used to analyze well-studied genomes, such as HIV-1, HBV and SARS-CoV. Accordingly, the performance of ZCURVE_V is generally better than that of GeneMark. Finally, ZCURVE_V may be downloaded and run locally, particularly facilitating its utilization, whereas GeneMark is not downloadable. Based on the above comparison, it is suggested that ZCURVE_V may serve as a preferred gene-finding tool for viral and phage genomes newly sequenced. However, it is also shown that the joint application of both systems, ZCURVE_V and GeneMark, leads to better gene-finding results. The system ZCURVE_V is freely available at: . Conclusion ZCURVE_V may serve as a preferred gene-finding tool used for viral and phage genomes, especially for anonymous viral and phage genomes

  8. Introduction to Viral Vectors and Other Delivery Methods for Gene Therapy of the Nervous System.

    PubMed

    Manfredsson, Fredric P

    2016-01-01

    The use of gene therapy in neuroscience research has become common place in many laboratories across the world. However, contrary to common belief, the practical application of viral or non-viral gene therapy is not as straightforward as it may seem. All too often investigators see their experiments fail due to low-quality third-party vectors or due to a lack of knowledge regarding the proper use of these tools. For example, researchers often find themselves performing experiments using the wrong methodology (e.g., using the wrong type of vector or mishandling the vector to the point where the efficacy is significantly reduced) resulting in experiments that potentially fail to accurately answer a hypothesis, or the generation of irreproducible data. Thus, it is important for investigators that seek to utilize gene therapy approaches to gain a basic understanding of how to apply this technology. This includes understanding how to appropriately design and execute an experiment, understanding various delivery vehicles (e.g., what virus to use), delivery methods (e.g., systemic versus intracranial injections), what expression system to use, and the time course involved with a particular expression system. This chapter is intended to present an overview of this fundamental knowledge, providing the researcher with a decision tree upon which to build their gene therapy experiment. PMID:26611575

  9. Statistical modelling of the formulation variables in non-viral gene delivery systems.

    PubMed

    Birchall, J C; Waterworth, C A; Luscombe, C; Parkins, D A; Gumbleton, M

    2001-06-01

    Traditionally, optimisation of a gene delivery formulation utilises a study design that involves altering only one formulation variable at any one time whilst keeping the other variables constant. As gene delivery formulations become more complex, e.g. to include multiple cellular and sub-cellular targeting elements, there will be an increasing requirement to generate and analyse data more efficiently and allow examination of the interaction between variables. This study aims to demonstrate the utility of multifactorial design, specifically a Central Composite Design, in modelling the responses size, zeta potential and in vitro transfection efficiency of some prototypic non-viral gene delivery vectors. i.e. cationic liposome-pDNA complexes, and extending the application of the design strategy to more complex vectors, i.e. tri-component lipid:polycation:DNA (LPD). The modelled predictions of how the above responses change as a function of formulation show consistency with an extensive literature base of data obtained using more traditional approaches, and highlight the robustness and utility of the Central Composite Design in examining key formulation variables in non-viral gene delivery systems. The approach should be further developed to maximise the predictive impact of data across the full range of pharmaceutical sciences. PMID:11697203

  10. Safety and Biodistribution Evaluation in Cynomolgus Macaques of rAAV2tYF-CB-hRS1, a Recombinant Adeno-Associated Virus Vector Expressing Retinoschisin

    PubMed Central

    Ye, Guo-Jie; Budzynski, Ewa; Sonnentag, Peter; Miller, Paul E.; Sharma, Alok K.; Ver Hoeve, James N.; Howard, Kellie; Knop, David R.; Neuringer, Martha; McGill, Trevor; Stoddard, Jonathan; Chulay, Jeffrey D.

    2015-01-01

    Applied Genetic Technologies Corporation is developing rAAV2tYF-CB-hRS1, a recombinant adeno-associated virus (rAAV) vector for treatment of X-linked retinoschisis (XLRS), an inherited retinal disease characterized by splitting (schisis) of retinal layers causing poor vision. We report here results of a study evaluating the safety and biodistribution of rAAV2tYF-CB-hRS1 in normal cynomolgus macaques. Three groups of male animals (n = 6 per group) received an intravitreal injection in one eye of either vehicle, or rAAV2tYF-CB-hRS1 at one of two dose levels (4 × 1010 or 4 × 1011 vg/eye). Half the animals were sacrificed after 14 days and the others after 91 or 115 days. The intravitreal injection procedure was well tolerated in all groups. Serial ophthalmic examinations demonstrated a dose-related anterior and posterior segment inflammatory response that improved over time. There were no test article-related effects on intraocular pressure, electroretinography, visual evoked potential, hematology, coagulation, clinical chemistry, or gross necropsy observations. Histopathological examination demonstrated minimal or moderate mononuclear infiltrates in 6 of 12 vector-injected eyes. Immunohistochemical staining showed RS1 labeling of the ganglion cell layer at the foveal slope in vector-injected eyes at both dose levels. Serum anti-AAV antibodies were detected in 4 of 6 vector-injected animals at the day 15 sacrifice and all vector-injected animals at later time points. No animals developed antibodies to RS1. Biodistribution studies demonstrated high levels of vector DNA in the injected eye but minimal or no vector DNA in any other tissue. These results support the use of rAAV2tYF-CB-hRS1 in clinical studies in patients with XLRS. PMID:26390090

  11. Recombinant adeno-associated virus serotype 9 with p65 ribozyme protects H9c2 cells from oxidative stress through inhibiting NF-κB signaling pathway

    PubMed Central

    SUN, Zhan; MA, Yi-Tong; CHEN, Bang-Dang; LIU, Fen

    2014-01-01

    Background Oxidative stress is a major mechanism underlying the pathogenesis of cardiovascular disease. It can trigger inflammatory cascades which are primarily mediated via nuclear factor-κB (NF-κB). The NF-κB transcription factor family includes several subunits (p50, p52, p65, c-Rel, and Rel B) that respond to myocardial ischemia. It has been proved that persistent myocyte NF-κB p65 activation in heart failure exacerbates cardiac remodeling. Mechods A recombinant adeno-associated virus serotype 9 carrying enhanced green fluorescent protein and anti-NF-κB p65 ribozyme (AAV9-R65-CMV-eGFP) was constructed. The cells were assessed by MTT assay, Annexin V–propidium iodide dual staining to study apoptosis. The expression of P65 and P50 were assessed by Western blot to investigate the underlying molecular mechanisms. Results After stimulation with H2O2 for 6 h, H9c2 cells viability decreased significantly, a large fraction of cells underwent apoptosis. We observed a rescue of H9c2 cells from H2O2-induced apoptosis in pretreatment with AAV9-R65-CMV-eGFP. Moreover, AAV9-R65-CMV-eGFP decreased H2O2-induced P65 expression. Conclusions AAV9-R65-CMV-eGFP protects H9c2 cells from oxidative stress induced apoptosis through down-regulation of P65 expression. These observations indicate that AAV9-R65-CMV-eGFP has the potential to exert cardioprotective effects against oxidative stress, which might be of great importance to clinical efficacy for cardiovascular disease. PMID:25593580

  12. The effect of recombinant adeno-associated virus-adiponectin (rAAV2/1-Acrp30) on glycolipid dysmetabolism and liver morphology in diabetic rats.

    PubMed

    Long, Wen; Hui Ju, Zhong; Fan, Zhang; Jing, Wang; Qiong, Li

    2014-09-15

    Adiponectin is an adipocytokine derived from adipocytes with insulin resistance-improving and anti-inflammatory activities. The level of Adiponectin is decreased in obesity, insulin resistance and Type 2 diabetes mellitus. The administration of recombinant adiponectin has been shown to improve hyperglycemia and insulin resistance in diabetic mice. Therefore, we investigated the effects of recombinant adeno-associated virus-adiponectin (rAAV2/1-Acrp30) on the glycolipid profile and liver morphology in streptozotocin-induced diabetic rats. Animals were fed a high-fat/high-glucose diet for 4weeks and diabetes induced by intraperitoneal administration of streptozotocin. The animals were divided randomly into four groups: diabetes control group, rAAV2/1-Acrp30 treatment group, vacuity virus group, and normal control group. Compared with diabetic rats and those in the vacuity virus group, animals treated with rAAV2/1-Acrp30 exhibited significantly lower values for glycaemic and lipidic profiles, and significantly higher levels of HDL. Although APN expression increased in the liver tissue, serum levels were not significantly increased. However, the rAAV2/1-Acrp30 treated animals showed amelioration of hepatic disease, accompanied by marked reduction in the expression of NF-κBp65 and IκBα. The results suggest that rAAV2/1-Acrp30 ameliorates glycolipid dysmetabolism and hepatic disease in streptozotocin-induced diabetic rats. These observations indicate that the function of rAAV2/1-Acrp30 is mediated by downregulated expression of NF-κBp65 and IκBα. PMID:25019654

  13. [Establishment of hepatitis B virus (HBV) chronic infection mouse model by in vivo transduction with a recombinant adeno-associated virus 8 carrying 1. 3 copies of HBV genome (rAAN8-1. 3HBV)].

    PubMed

    Dong, Xiao-Yan; Yu, Chi-Jie; Wang, Gang; Tian, Wen-Hong; Lu, Yue; Zhang, Feng-Wei; Wang, Wen; Wang, Yue; Tan, Wen-Jie; Wu, Xiao-Bing

    2010-11-01

    In this report, we developed a HBV infection model in C57BL/6 mouse line by in vivo injection of a recombinant adeno-associated virus 8 vector carrying 1. 3 copies of HBV genome (ayw subtype) (rAAV8-1. 3HBV). We firstly prepared and purified the rAAV8-1. 3HBV and then injected it into three C57BL/6 mice with the dose of 2 x 10e11vg, respectively. HBsAg and HBeAg were assayed in sera collected at different time points post injection. Ten weeks post injection, the three mice were sacrificed and blood and liver tissue were taken for assay. Copies of HBV DNA were detected by real time PCR and the way of HBV DNA replication was identified by PCR. Subsequently, detection of HBV antigen by immunohistochemistry and pathology analysis of liver tissue of mice were performed. The results suggested that expression of HBsAg and HBeAg lasted for at least 10 weeks in mice sera. Among mice injected with rAAV8-1. 3HBV, HBsAg levels were showed an 'increasing-decreasing-increasing' pattern (the lowest level at the 4th week post injection), while HBeAg levels were kept high and relatively stable. HBV DNA copies were 4.2 x 10(3), 3.6 x 10(3), 2.5 x 10(3) copies/mL in sera and 8.0 x 10(6), 5.7 x 10(6), 2.6 x 10(6) copies/g in hepatic tissues of three mice, respectively. We found that the linear 1. 3HBV DNA in the rAAV8-1. 3HBV could self form into circular HBV genome and replicate in livers of HBV transfected mice. HBsAg and HBcAg were both positive in liver tissue of mice injected with rAAV8-1. 3HBV and no obvious pathological characters were found in liver of mice injected with rAAV8-1. 3HBV. In conclusion, we successfully developed a HBV chronic infection model in C57BL/6 mouse line by in vivo transduction with the recombinant virus rAAV8-1. 3HBV, in which HBV genes could be continuously expressed and replicated over 10 weeks, and paved a way for further characterization of the human chronic hepatitis B virus infection and evaluation of vaccine and anti-HBV agents. PMID:21344744

  14. Production of Recombinant Adeno-associated Virus Vectors Using Suspension HEK293 Cells and Continuous Harvest of Vector From the Culture Media for GMP FIX and FLT1 Clinical Vector.

    PubMed

    Grieger, Joshua C; Soltys, Stephen M; Samulski, Richard Jude

    2016-02-01

    Adeno-associated virus (AAV) has shown great promise as a gene therapy vector in multiple aspects of preclinical and clinical applications. Many developments including new serotypes as well as self-complementary vectors are now entering the clinic. With these ongoing vector developments, continued effort has been focused on scalable manufacturing processes that can efficiently generate high-titer, highly pure, and potent quantities of rAAV vectors. Utilizing the relatively simple and efficient transfection system of HEK293 cells as a starting point, we have successfully adapted an adherent HEK293 cell line from a qualified clinical master cell bank to grow in animal component-free suspension conditions in shaker flasks and WAVE bioreactors that allows for rapid and scalable rAAV production. Using the triple transfection method, the suspension HEK293 cell line generates greater than 1 × 10(5) vector genome containing particles (vg)/cell or greater than 1 × 10(14) vg/l of cell culture when harvested 48 hours post-transfection. To achieve these yields, a number of variables were optimized such as selection of a compatible serum-free suspension media that supports both growth and transfection, selection of a transfection reagent, transfection conditions and cell density. A universal purification strategy, based on ion exchange chromatography methods, was also developed that results in high-purity vector preps of AAV serotypes 1-6, 8, 9 and various chimeric capsids tested. This user-friendly process can be completed within 1 week, results in high full to empty particle ratios (>90% full particles), provides postpurification yields (>1 × 10(13) vg/l) and purity suitable for clinical applications and is universal with respect to all serotypes and chimeric particles. To date, this scalable manufacturing technology has been utilized to manufacture GMP phase 1 clinical AAV vectors for retinal neovascularization (AAV2), Hemophilia B (scAAV8), giant axonal

  15. Peripherally restricted acute phase response to a viral mimic alters hippocampal gene expression.

    PubMed

    Michalovicz, Lindsay T; Konat, Gregory W

    2014-03-01

    We have previously shown that peripherally restricted acute phase response (APR) elicited by intraperitoneal (i.p.) injection of a viral mimic, polyinosinic-polycytidylic acid (PIC), renders the brain hypersusceptible to excitotoxic insult as seen from profoundly exacerbated kainic acid (KA)-induced seizures. In the present study, we found that this hypersusceptibility was protracted for up to 72 h. RT-PCR profiling of hippocampal gene expression revealed rapid upregulation of 23 genes encoding cytokines, chemokines and chemokine receptors generally within 6 h after PIC challenge. The expression of most of these genes decreased by 24 h. However, two chemokine genes, i.e., Ccl19 and Cxcl13 genes, as well as two chemokine receptor genes, Ccr1 and Ccr7, remained upregulated for 72 h suggesting their possible involvement in the induction and sustenance of seizure hypersusceptibility. Also, 12 genes encoding proteins related to glutamatergic and GABAergic neurotransmission featured initial upregulation or downregulation followed by gradual normalization. The upregulation of the Gabrr3 gene remained upregulated at 72 h, congruent with its plausible role in the hypersusceptible phenotype. Moreover, the expression of ten microRNAs (miRs) was rapidly affected by PIC challenge, but their levels generally exhibited oscillating profiles over the time course of seizure hypersusceptibility. These results indicate that protracted seizure susceptibility following peripheral APR is associated with a robust polygenic response in the hippocampus. PMID:24363211

  16. CONVECTION-ENHANCED DELIVERY AND SYSTEMIC MANNITOL INCREASE GENE PRODUCT DISTRIBUTION OF AAV VECTORS 5, 8, AND 9 AND INCREASE GENE PRODUCT IN THE ADULT MOUSE BRAIN

    PubMed Central

    Carty, Nikisha; Lee, Daniel; Dickey, Chad; Ceballos-Diaz, Carolina; Jansen-West, Karen; Golde, Todd E.; Gordon, Marcia N.; Morgan, Dave; Nash, Kevin

    2010-01-01

    The use of recombinant adeno-associated viral (rAAV) vectors as a means of gene delivery to the central nervous system has emerged as a potentially viable method for the treatment of several types of degenerative brain diseases. However, a limitation of typical intracranial injections into the adult brain parenchyma is the relatively restricted distribution of the delivered gene to large brain regions such as the cortex, presumably due to confined dispersion of the injected particles. Optimizing the administration techniques to maximize gene distribution and gene expression is an important step in developing gene therapy studies. Here, we have found additive increases in distribution when 3 methods to increase brain distribution of rAAV were combined. The convection enhanced delivery (CED) method with the step-design cannula was used to deliver rAAV vector serotypes 5, 8 and 9 encoding GFP into the hippocampus of the mouse brain. While the CED method improved distribution of all 3 serotypes, the combination of rAAV9 and CED was particularly effective. Systemic mannitol administration, which reduces intracranial pressure, also further expanded distribution of GFP expression, in particular, increased expression on the contralateral hippocampi. These data suggest that combining advanced injection techniques with newer rAAV serotypes greatly improves viral vector distribution, which could have significant benefits for implementation of gene therapy strategies. PMID:20951738

  17. Hairpin RNA Targeting Multiple Viral Genes Confers Strong Resistance to Rice Black-Streaked Dwarf Virus

    PubMed Central

    Wang, Fangquan; Li, Wenqi; Zhu, Jinyan; Fan, Fangjun; Wang, Jun; Zhong, Weigong; Wang, Ming-Bo; Liu, Qing; Zhu, Qian-Hao; Zhou, Tong; Lan, Ying; Zhou, Yijun; Yang, Jie

    2016-01-01

    Rice black-streaked dwarf virus (RBSDV) belongs to the genus Fijivirus in the family of Reoviridae and causes severe yield loss in rice-producing areas in Asia. RNA silencing, as a natural defence mechanism against plant viruses, has been successfully exploited for engineering virus resistance in plants, including rice. In this study, we generated transgenic rice lines harbouring a hairpin RNA (hpRNA) construct targeting four RBSDV genes, S1, S2, S6 and S10, encoding the RNA-dependent RNA polymerase, the putative core protein, the RNA silencing suppressor and the outer capsid protein, respectively. Both field nursery and artificial inoculation assays of three generations of the transgenic lines showed that they had strong resistance to RBSDV infection. The RBSDV resistance in the segregating transgenic populations correlated perfectly with the presence of the hpRNA transgene. Furthermore, the hpRNA transgene was expressed in the highly resistant transgenic lines, giving rise to abundant levels of 21–24 nt small interfering RNA (siRNA). By small RNA deep sequencing, the RBSDV-resistant transgenic lines detected siRNAs from all four viral gene sequences in the hpRNA transgene, indicating that the whole chimeric fusion sequence can be efficiently processed by Dicer into siRNAs. Taken together, our results suggest that long hpRNA targeting multiple viral genes can be used to generate stable and durable virus resistance in rice, as well as other plant species. PMID:27187354

  18. Cholesterol derived cationic lipids as potential non-viral gene delivery vectors and their serum compatibility.

    PubMed

    Ju, Jia; Huan, Meng-Lei; Wan, Ning; Hou, Yi-Lin; Ma, Xi-Xi; Jia, Yi-Yang; Li, Chen; Zhou, Si-Yuan; Zhang, Bang-Le

    2016-05-15

    Cholesterol derivatives M1-M6 as synthetic cationic lipids were designed and the biological evaluation of the cationic liposomes based on them as non-viral gene delivery vectors were described. Plasmid pEGFP-N1, used as model gene, was transferred into 293T cells by cationic liposomes formed with M1-M6 and transfection efficiency and GFP expression were tested. Cationic liposomes prepared with cationic lipids M1-M6 exhibited good transfection activity, and the transfection activity was parallel (M2 and M4) or superior (M1 and M6) to that of DC-Chol derived from the same backbone. Among them, the transfection efficiency of cationic lipid M6 was parallel to that of the commercially available Lipofectamine2000. The optimal formulation of M1 and M6 were found to be at a mol ratio of 1:0.5 for cationic lipid/DOPE, and at a N/P charge mol ratio of 3:1 for liposome/DNA. Under optimized conditions, the efficiency of M1 and M6 is greater than that of all the tested commercial liposomes DC-Chol and Lipofectamine2000, even in the presence of serum. The results indicated that M1 and M6 exhibited low cytotoxicity, good serum compatibility and efficient transfection performance, having the potential of being excellent non-viral vectors for gene delivery. PMID:27072908

  19. Hairpin RNA Targeting Multiple Viral Genes Confers Strong Resistance to Rice Black-Streaked Dwarf Virus.

    PubMed

    Wang, Fangquan; Li, Wenqi; Zhu, Jinyan; Fan, Fangjun; Wang, Jun; Zhong, Weigong; Wang, Ming-Bo; Liu, Qing; Zhu, Qian-Hao; Zhou, Tong; Lan, Ying; Zhou, Yijun; Yang, Jie

    2016-01-01

    Rice black-streaked dwarf virus (RBSDV) belongs to the genus Fijivirus in the family of Reoviridae and causes severe yield loss in rice-producing areas in Asia. RNA silencing, as a natural defence mechanism against plant viruses, has been successfully exploited for engineering virus resistance in plants, including rice. In this study, we generated transgenic rice lines harbouring a hairpin RNA (hpRNA) construct targeting four RBSDV genes, S1, S2, S6 and S10, encoding the RNA-dependent RNA polymerase, the putative core protein, the RNA silencing suppressor and the outer capsid protein, respectively. Both field nursery and artificial inoculation assays of three generations of the transgenic lines showed that they had strong resistance to RBSDV infection. The RBSDV resistance in the segregating transgenic populations correlated perfectly with the presence of the hpRNA transgene. Furthermore, the hpRNA transgene was expressed in the highly resistant transgenic lines, giving rise to abundant levels of 21-24 nt small interfering RNA (siRNA). By small RNA deep sequencing, the RBSDV-resistant transgenic lines detected siRNAs from all four viral gene sequences in the hpRNA transgene, indicating that the whole chimeric fusion sequence can be efficiently processed by Dicer into siRNAs. Taken together, our results suggest that long hpRNA targeting multiple viral genes can be used to generate stable and durable virus resistance in rice, as well as other plant species. PMID:27187354

  20. HAVCR1 Gene Haplotypes and Infection by Different Viral Hepatitis C Virus Genotypes

    PubMed Central

    Abad-Molina, Cristina; Garcia-Lozano, José-Raúl; Montes-Cano, Marco-Antonio; Torres-Cornejo, Almudena; Torrecillas, Fuensanta; Aguilar-Reina, José; Romero-Gómez, Manuel; López-Cortés, Luis-Fernando; Núñez-Roldan, Antonio

    2012-01-01

    The hepatitis A virus cellular receptor 1 (HAVCR1) gene is highly polymorphic, and several variants have been associated with susceptibility to allergic and autoimmune diseases. The HAVCR1 gene region was identified as a candidate for hepatitis C virus (HCV) natural clearance in a genotyping study of selected immune response genes in both European-American and African-American populations. The aim of the present study was to explore the influence of HAVCR1 in the outcome of HCV infection in the Spanish population. Three cohorts, consisting of 354 subjects with persistent HCV infection (285 with persistent HCV monoinfection and 69 with natural clearance), 182 coinfected HIV/HCV patients, and 320 controls, were included. Samples were genotyped in several polymorphic positions, insertion/deletion variants in exon 4 and tag single nucleotide polymorphisms (SNPs), in order to define previously described HAVCR1 haplotypes (haplotypes A to D). No statistically significant differences were observed with spontaneous resolution of infection or with viral clearance after treatment. Nevertheless, different rates of infection by viral genotypes (G's) were observed among the HAVCR1 haplotypes. Individuals bearing haplotype C had the highest viral G1 infection rate when compared to individuals bearing other haplotypes (75.82% versus 57.72%, respectively; corrected P value [Pc], 3.2 × 10−4; odds ratio [OR], 2.30; 95% confidence interval [CI], 1.51 to 3.47). Thus, HAVCR1 could be involved in susceptibility or resistance to infection by a particular HCV genotype. PMID:22190394

  1. Deep sequencing of the viral phoH gene reveals temporal variation, depth-specific composition, and persistent dominance of the same viral phoH genes in the Sargasso Sea.

    PubMed

    Goldsmith, Dawn B; Parsons, Rachel J; Beyene, Damitu; Salamon, Peter; Breitbart, Mya

    2015-01-01

    Deep sequencing of the viral phoH gene, a host-derived auxiliary metabolic gene, was used to track viral diversity throughout the water column at the Bermuda Atlantic Time-series Study (BATS) site in the summer (September) and winter (March) of three years. Viral phoH sequences reveal differences in the viral communities throughout a depth profile and between seasons in the same year. Variation was also detected between the same seasons in subsequent years, though these differences were not as great as the summer/winter distinctions. Over 3,600 phoH operational taxonomic units (OTUs; 97% sequence identity) were identified. Despite high richness, most phoH sequences belong to a few large, common OTUs whereas the majority of the OTUs are small and rare. While many OTUs make sporadic appearances at just a few times or depths, a small number of OTUs dominate the community throughout the seasons, depths, and years. PMID:26157645

  2. Deep sequencing of the viral phoH gene reveals temporal variation, depth-specific composition, and persistent dominance of the same viral phoH genes in the Sargasso Sea

    PubMed Central

    Goldsmith, Dawn B.; Parsons, Rachel J.; Beyene, Damitu; Salamon, Peter

    2015-01-01

    Deep sequencing of the viral phoH gene, a host-derived auxiliary metabolic gene, was used to track viral diversity throughout the water column at the Bermuda Atlantic Time-series Study (BATS) site in the summer (September) and winter (March) of three years. Viral phoH sequences reveal differences in the viral communities throughout a depth profile and between seasons in the same year. Variation was also detected between the same seasons in subsequent years, though these differences were not as great as the summer/winter distinctions. Over 3,600 phoH operational taxonomic units (OTUs; 97% sequence identity) were identified. Despite high richness, most phoH sequences belong to a few large, common OTUs whereas the majority of the OTUs are small and rare. While many OTUs make sporadic appearances at just a few times or depths, a small number of OTUs dominate the community throughout the seasons, depths, and years. PMID:26157645

  3. Temperature-sensitive vaccinia virus mutants identify a gene with an essential role in viral replication.

    PubMed Central

    Rempel, R E; Anderson, M K; Evans, E; Traktman, P

    1990-01-01

    Vaccinia virus mutants ts2 and ts25, members of the same complementation group, exhibit a temperature-dependent arrest at the stage of viral DNA replication. The lesions responsible for the mutant phenotypes have been localized to the far left region of the HindIII B genomic fragment by marker rescue studies. Hybrid selection analyses established that the DNA fragments positive for rescue represented the first open reading frame of the HindIII B fragment and encoded a 30-kilodalton protein. The gene is expressed early after infection as a rightwardly transcribed 1-kilobase-pair mRNA whose coordinates were determined by S1 nuclease mapping. To further the phenotypic analysis of the mutants, the accumulation of viral DNA sequences during permissive and nonpermissive infections was quantitated. The extent of the DNA- phenotype was shown to vary in different cell types. In mouse L cells at either high or low multiplicity of infection, nonpermissive DNA synthesis was less than 5% of that seen in permissive infections. This severe defect was mirrored by correspondingly low viral yields. In infections of BSC40 monkey cells, however, the deficiencies in both DNA synthesis and virus production were far less severe. For one mutant (ts2), the temperature sensitivity in BSC40 cells varied inversely with the multiplicity of infection. Images PMID:2296077

  4. Minicircle microporation-based non-viral gene delivery improved the targeting of mesenchymal stem cells to an injury site.

    PubMed

    Mun, Ji-Young; Shin, Keun Koo; Kwon, Ohsuk; Lim, Yong Taik; Oh, Doo-Byoung

    2016-09-01

    Genetic engineering approaches to improve the therapeutic potential of mesenchymal stem cells (MSCs) have been made by viral and non-viral gene delivery methods. Viral methods have severe limitations in clinical application because of potential oncogenic, pathogenic, and immunogenic risks, while non-viral methods have suffered from low transfection efficiency and transient weak expression as MSCs are hard-to-transfect cells. In this study, minicircle, which is a minimal expression vector free of bacterial sequences, was employed for MSC transfection as a non-viral gene delivery method. The conventional cationic liposome method was not effective for MSC transfection as it resulted in very low transfection efficiency (less than 5%). Microporation, a new electroporation method, greatly improved the transfection efficiency of minicircles by up to 66% in MSCs without any significant loss of cell viability. Furthermore, minicircle microporation generated much stronger and prolonged transgene expression compared with plasmid microporation. When MSCs microporated with minicircle harboring firefly luciferase gene were subcutaneously injected to mice, the bioluminescence continued for more than a week, whereas the bioluminescence of the MSCs induced by plasmid microporation rapidly decreased and disappeared in mice within three days. By minicircle microporation as a non-viral gene delivery, MSCs engineered to overexpress CXCR4 showed greatly increased homing ability toward an injury site as confirmed through in vivo bioluminescence imaging in mice. In summary, the engineering of MSCs through minicircle microporation is expected to enhance the therapeutic potential of MSCs in clinical applications. PMID:27315214

  5. Differentially expressed genes after viral haemorrhagic septicaemia virus infection in olive flounder (Paralichthys olivaceus).

    PubMed

    Hwang, Jee Youn; Kwon, Mun-Gyeong; Seo, Jung Soo; Do, Jung Wan; Park, Myoung-Ae; Jung, Sung-Hee; Ahn, Sang Jung

    2016-09-25

    A strain of viral haemorrhagic septicaemia virus (VHSV) was isolated from cultured olive flounder (Paralichthys olivaceus) during epizootics in South Korean. This strain showed high mortality to olive flounder in in vivo challenge experiment. The complete genomic RNA sequences were determined and phylogenetic analysis of the amino acid sequences of glycoprotein revealed that this isolate was grouped into genotype IVa of genus Novirhabdovirus. Expression profile of genes in olive flounder was analyzed at day 1 and day3 after infection with this VHSV isolate by using cDNA microarray containing olive flounder 13K cDNA clones. Microarray analysis revealed 785 up-regulated genes and 641 down-regulated genes by at least two-fold in virus-infected fish compared to healthy control groups. Among 785 up-regulated genes, we identified seven immune response-associated genes, including the interferon (IFN)-induced 56-kDa protein (IFI56), suppressor of cytokine signaling 1 (SOCS1), interleukin 8 (IL-8), cluster of differentiation 83 (CD83), α-globin (HBA), VHSV-induced protein-6 (VHSV6), and cluster of differentiation antigen 9 (CD9). Our results confirm previous reports that even virulent strain of VHSV induces expression of genes involved in protective immunity against VHSV. PMID:27599933