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Sample records for recombinant viral vector

  1. Retroviral Vectors for Analysis of Viral Mutagenesis and Recombination

    Directory of Open Access Journals (Sweden)

    Jonathan M.O. Rawson

    2014-09-01

    Full Text Available Retrovirus population diversity within infected hosts is commonly high due in part to elevated rates of replication, mutation, and recombination. This high genetic diversity often complicates the development of effective diagnostics, vaccines, and antiviral drugs. This review highlights the diverse vectors and approaches that have been used to examine mutation and recombination in retroviruses. Retroviral vectors for these purposes can broadly be divided into two categories: those that utilize reporter genes as mutation or recombination targets and those that utilize viral genes as targets of mutation or recombination. Reporter gene vectors greatly facilitate the detection, quantification, and characterization of mutants and/or recombinants, but may not fully recapitulate the patterns of mutagenesis or recombination observed in native viral gene sequences. In contrast, the detection of mutations or recombination events directly in viral genes is more biologically relevant but also typically more challenging and inefficient. We will highlight the advantages and disadvantages of the various vectors and approaches used as well as propose ways in which they could be improved.

  2. Retroviral vectors for analysis of viral mutagenesis and recombination.

    Science.gov (United States)

    Rawson, Jonathan M O; Mansky, Louis M

    2014-09-24

    Retrovirus population diversity within infected hosts is commonly high due in part to elevated rates of replication, mutation, and recombination. This high genetic diversity often complicates the development of effective diagnostics, vaccines, and antiviral drugs. This review highlights the diverse vectors and approaches that have been used to examine mutation and recombination in retroviruses. Retroviral vectors for these purposes can broadly be divided into two categories: those that utilize reporter genes as mutation or recombination targets and those that utilize viral genes as targets of mutation or recombination. Reporter gene vectors greatly facilitate the detection, quantification, and characterization of mutants and/or recombinants, but may not fully recapitulate the patterns of mutagenesis or recombination observed in native viral gene sequences. In contrast, the detection of mutations or recombination events directly in viral genes is more biologically relevant but also typically more challenging and inefficient. We will highlight the advantages and disadvantages of the various vectors and approaches used as well as propose ways in which they could be improved.

  3. Production and titering of recombinant adeno-associated viral vectors.

    Science.gov (United States)

    McClure, Christina; Cole, Katy L H; Wulff, Peer; Klugmann, Matthias; Murray, Andrew J

    2011-11-27

    In recent years recombinant adeno-associated viral vectors (AAV) have become increasingly valuable for in vivo studies in animals, and are also currently being tested in human clinical trials. Wild-type AAV is a non-pathogenic member of the parvoviridae family and inherently replication-deficient. The broad transduction profile, low immune response as well as the strong and persistent transgene expression achieved with these vectors has made them a popular and versatile tool for in vitro and in vivo gene delivery. rAAVs can be easily and cheaply produced in the laboratory and, based on their favourable safety profile, are generally given a low safety classification. Here, we describe a method for the production and titering of chimeric rAAVs containing the capsid proteins of both AAV1 and AAV2. The use of these so-called chimeric vectors combines the benefits of both parental serotypes such as high titres stocks (AAV1) and purification by affinity chromatography (AAV2). These AAV serotypes are the best studied of all AAV serotypes, and individually have a broad infectivity pattern. The chimeric vectors described here should have the infectious properties of AAV1 and AAV2 and can thus be expected to infect a large range of tissues, including neurons, skeletal muscle, pancreas, kidney among others. The method described here uses heparin column purification, a method believed to give a higher viral titer and cleaner viral preparation than other purification methods, such as centrifugation through a caesium chloride gradient. Additionally, we describe how these vectors can be quickly and easily titered to give accurate reading of the number of infectious particles produced.

  4. Construction of recombinant adeno-associated viral vectors in human neurenergen-3 gene

    Institute of Scientific and Technical Information of China (English)

    Xiangli Wang; Haili Wang; Baojie Mi

    2007-01-01

    BACKGROUND: Research of transgene brings hope for gene therapy of various diseases; in addition, some projects have been tested in clinic. Recently, the focus has been to find an ideal vehicle and a suitable therapeutic gene.OBJECTIVE: To explore an effective way to construct recombinant adeno-associated viral vectors expression in human neurnnergen-3 gene. DESIGN: Gene directed cloning.SETTING: Central Laboratory of Northern China Coal Medical College.MATERIALS: DH5a competent bacillus coli strain was provided by Capital Medical University; pCDNA3-NT-3 by professor Chen from Bengbu Medical College; pAAV-Laze, pAAV-Helper, pAAV-RC and pAAV-MCS plasmids by Capital Medical University; HEK293 cells by Cell Center of Basic Medical College of Tongji Medical University.METHODS: NT-3 genes which were selected from pCDNA3-NT-3 plasmids were cloned in pAAV-MCS to form a recombinant adeno-associated viral plasmid (pAAV-NT-3). pAAV-NT-3, pAAV-RC, pAAV-LacZ and pHelper plasmids were extracted, purified and subjected to enzyme-shearing evaluation. In addition, pAAV-NT-3 and pAAV-LacZ were cotransfected with pHelper and pAAV-RC, respectively into AVV-293 cells with DNA mediated by calcium superphosphate transfection gene; and then, AVV-293 cells were packed into recombinant adeno-associated viral rAAV-NT-3 and rAAV-LacZ. After collection of viral particles, rAAV-LacZ viral stock solution was diluted based on ratio of 10:1 and the mixture was used to infect HT1080 cells. X-gal stain was used to measure virus liter.MAIN OUTCOME MEASURES: Size of targeted gene fragments, validity of vehicle construction and virus liter.RESULTS: Targeted gene NT-3 was successfully inserted into the relative vehicle pAAV and pAAV-NT-3 was correctly recongnized by enzyme-shearing evaluation. Enzyme-shearing electrophoresis demonstrated that pAAV-NT-3, pAAV-RC, pAAV-LacZ and pHelper plasmids were successfully extracted and purified.β-galactoside staining in situ indicated that LacZ genes were

  5. Current good manufacturing practice production of an oncolytic recombinant vesicular stomatitis viral vector for cancer treatment.

    Science.gov (United States)

    Ausubel, L J; Meseck, M; Derecho, I; Lopez, P; Knoblauch, C; McMahon, R; Anderson, J; Dunphy, N; Quezada, V; Khan, R; Huang, P; Dang, W; Luo, M; Hsu, D; Woo, S L C; Couture, L

    2011-04-01

    Vesicular stomatitis virus (VSV) is an oncolytic virus currently being investigated as a promising tool to treat cancer because of its ability to selectively replicate in cancer cells. To enhance the oncolytic property of the nonpathologic laboratory strain of VSV, we generated a recombinant vector [rVSV(MΔ51)-M3] expressing murine gammaherpesvirus M3, a secreted viral chemokine-binding protein that binds to a broad range of mammalian chemokines with high affinity. As previously reported, when rVSV(MΔ51)-M3 was used in an orthotopic model of hepatocellular carcinoma (HCC) in rats, it suppressed inflammatory cell migration to the virus-infected tumor site, which allowed for enhanced intratumoral virus replication leading to increased tumor necrosis and substantially prolonged survival. These encouraging results led to the development of this vector for clinical translation in patients with HCC. However, a scalable current Good Manufacturing Practice (cGMP)-compliant manufacturing process has not been described for this vector. To produce the quantities of high-titer virus required for clinical trials, a process that is amenable to GMP manufacturing and scale-up was developed. We describe here a large-scale (50-liter) vector production process capable of achieving crude titers on the order of 10(9) plaque-forming units (PFU)/ml under cGMP. This process was used to generate a master virus seed stock and a clinical lot of the clinical trial agent under cGMP with an infectious viral titer of approximately 2 × 10(10) PFU/ml (total yield, 1 × 10(13) PFU). The lot has passed all U.S. Food and Drug Administration-mandated release testing and will be used in a phase 1 clinical translational trial in patients with advanced HCC.

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

    NARCIS (Netherlands)

    Vidovic, D; Gijsbers, R; Quiles Jimenez, A; Dooley, J; Van Den Haute, C; Van der Perren, A; Liston, A; Baekelandt, V; Debyser, Z; Carlon, MS

    2015-01-01

    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

  7. Development of Recombinant Vaccine Using Herpesvirus of Turkey (Hvt as Vector for Several Viral Diseases in Poultry Industry

    Directory of Open Access Journals (Sweden)

    Risza Hartawan

    2011-03-01

    Full Text Available Herpesvirus of turkey (HVT has been utilised as live vaccine against Marek’s disease in poultry industry world-wide for many years. However, the potency of HVT is not limited on the Marek’s disease only. Along with rapid development of recombinant technique, the potency of HVT can be broaden for other diseases. As naturally apathogenic virus, HVT is a suitable candidate as vector vaccine to express important antigens of viral pathogens. Several researches have been dedicated to design HVT recombinant vaccine by inserting gene of important virus, such as Marek’s disease virus (MDV, immuno bursal disease virus (IBDV, Newcastle disease virus (NDV and Avian Influenza virus (AIV. Therefore, the future recombinant of HVT has been expected to be better in performance along with the improvement of recombinant technique.

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

    Science.gov (United States)

    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.

  9. Recombinant adeno-associated viral (rAAV) vectors mediate efficient gene transduction in cultured neonatal and adult microglia.

    Science.gov (United States)

    Su, Wei; Kang, John; Sopher, Bryce; Gillespie, James; Aloi, Macarena S; Odom, Guy L; Hopkins, Stephanie; Case, Amanda; Wang, David B; Chamberlain, Jeffrey S; Garden, Gwenn A

    2016-01-01

    Microglia are a specialized population of myeloid cells that mediate CNS innate immune responses. Efforts to identify the cellular and molecular mechanisms that regulate microglia behaviors have been hampered by the lack of effective tools for manipulating gene expression. Cultured microglia are refractory to most chemical and electrical transfection methods, yielding little or no gene delivery and causing toxicity and/or inflammatory activation. Recombinant adeno-associated viral (rAAVs) vectors are non-enveloped, single-stranded DNA vectors commonly used to transduce many primary cell types and tissues. In this study, we evaluated the feasibility and efficiency of utilizing rAAV serotype 2 (rAAV2) to modulate gene expression in cultured microglia. rAAV2 yields high transduction and causes minimal toxicity or inflammatory response in both neonatal and adult microglia. To demonstrate that rAAV transduction can induce functional protein expression, we used rAAV2 expressing Cre recombinase to successfully excise a LoxP-flanked miR155 gene in cultured microglia. We further evaluated rAAV serotypes 5, 6, 8, and 9, and observed that all efficiently transduced cultured microglia to varying degrees of success and caused little or no alteration in inflammatory gene expression. These results provide strong encouragement for the application of rAAV-mediated gene expression in microglia for mechanistic and therapeutic purposes. Neonatal microglia are functionally distinct from adult microglia, although the majority of in vitro studies utilize rodent neonatal microglia cultures because of difficulties of culturing adult cells. In addition, cultured microglia are refractory to most methods for modifying gene expression. Here, we developed a novel protocol for culturing adult microglia and evaluated the feasibility and efficiency of utilizing Recombinant Adeno-Associated Virus (rAAV) to modulate gene expression in cultured microglia.

  10. Use of DNA and recombinant canarypox viral (ALVAC) vectors for equine herpes virus vaccination.

    Science.gov (United States)

    Minke, J M; Fischer, L; Baudu, Ph; Guigal, P M; Sindle, T; Mumford, J A; Audonnet, J C

    2006-05-15

    In this study, experimental canarypox virus (ALVAC) and plasmid DNA recombinant vaccines expressing the gB, gC and gD glycoproteins of EHV-1 were assessed for their ability to protect conventional ponies against a respiratory challenge with EHV-1. In addition, potential means of enhancing serological responses in horses to ALVAC and DNA vaccination were explored. These included co-administration of the antigen with conventional adjuvants, complexation with DMRIE-DOPE and co-expression of the antigen along with equine GM-CSF. Groups of EHV primed ponies were vaccinated twice intra-muscularly with one dose of the appropriate test vaccine at an interval of 5 weeks. Two to 3 weeks after the second vaccination, ponies were infected intra-nasally with the virulent Ab4 strain of EHV-1 after which they were observed clinically and sampled for virological investigations. The results demonstrated that DNA and ALVAC vaccination markedly reduced virus excretion after challenge in terms of duration and magnitude, but failed to protect against cell-associated viremia. Noteworthy was the almost complete absence of virus excretion in the group of ponies vaccinated with ALVAC-EHV in the presence of Carbopol adjuvant or DNA plasmid formulated with aluminium phosphate. The administration of the DNA vaccine in the presence of GM-CSF and formulated in DMRIE-DOPE and of the ALVAC vaccine in the presence of Carbopol adjuvant significantly improved virus neutralising antibody responses to EHV-1. These findings indicate that DNA and ALVAC vaccination is a promising approach for the immunological control of EHV-1 infection, but that more research is needed to identify the immunodominant protective antigens of EHV-1 and their interaction with the equine immune system.

  11. Integration-free reprogramming of human somatic cells to induced pluripotent stem cells (iPSCs) without viral vectors, recombinant DNA, and genetic modification.

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    Heng, Boon Chin; Fussenegger, Martin

    2014-01-01

    Stem cells are envisaged to be integral components of multicellular systems engineered for therapeutic applications. The reprogramming of somatic cells to induced pluripotent stem cells (iPSCs) via recombinant expression of a limited number of transcription factors, which was first achieved by Yamanaka and colleagues in 2007, heralded a major breakthrough in the stem cell field. Since then, there has been rapid progress in the field of iPSC generation, including the identification of various small molecules that can enhance reprogramming efficiency and reduce the number of different transcription factors required for reprogramming. Nevertheless, the major obstacles facing clinical applications of iPSCs are safety concerns associated with the use of viral vectors and recombinant DNA for expressing the appropriate transcription factors during reprogramming. In particular, permanent genetic modifications to newly reprogrammed iPSCs have to be avoided in order to meet stringent safety requirements for clinical therapy. These safety challenges can be overcome by new technology platforms that enable cellular reprogramming to iPSCs without the need to utilize either recombinant DNA or viral vectors. The use of recombinant cell-penetrating peptides and direct transfection of synthetic mRNA encoding appropriate transcription factors have both been shown to successfully reprogram somatic cells to iPSCs. It has also been shown more recently that the direct transfection of certain miRNA species can reprogram somatic cells to pluripotency without the need for any of the transcription factors commonly utilized for iPSC generation. This chapter describes protocols for iPSC generation with these new techniques, which would obviate the use of recombinant DNA and viral vectors in cellular reprogramming, thus avoiding permanent genetic modification to the reprogrammed cells.

  12. Phase 2 clinical trial of a recombinant adeno-associated viral vector expressing α1-antitrypsin: interim results.

    LENUS (Irish Health Repository)

    Flotte, Terence R

    2011-10-01

    Recombinant adeno-associated virus (rAAV) vectors offer promise for the gene therapy of α(1)-antitrypsin (AAT) deficiency. In our prior trial, an rAAV vector expressing human AAT (rAAV1-CB-hAAT) provided sustained, vector-derived AAT expression for >1 year. In the current phase 2 clinical trial, this same vector, produced by a herpes simplex virus complementation method, was administered to nine AAT-deficient individuals by intramuscular injection at doses of 6.0×10(11), 1.9×10(12), and 6.0×10(12) vector genomes\\/kg (n=3 subjects\\/dose). Vector-derived expression of normal (M-type) AAT in serum was dose dependent, peaked on day 30, and persisted for at least 90 days. Vector administration was well tolerated, with only mild injection site reactions and no serious adverse events. Serum creatine kinase was transiently elevated on day 30 in five of six subjects in the two higher dose groups and normalized by day 45. As expected, all subjects developed anti-AAV antibodies and interferon-γ enzyme-linked immunospot responses to AAV peptides, and no subjects developed antibodies to AAT. One subject in the mid-dose group developed T cell responses to a single AAT peptide unassociated with any clinical effects. Muscle biopsies obtained on day 90 showed strong immunostaining for AAT and moderate to marked inflammatory cell infiltrates composed primarily of CD3-reactive T lymphocytes that were primarily of the CD8(+) subtype. These results support the feasibility and safety of AAV gene therapy for AAT deficiency, and indicate that serum levels of vector-derived normal human AAT >20 μg\\/ml can be achieved. However, further improvements in the design or delivery of rAAV-AAT vectors will be required to achieve therapeutic target serum AAT concentrations.

  13. HIV-1重组病毒载体疫苗研究进展%Development of HIV-1 recombinant viral vector vaccines

    Institute of Scientific and Technical Information of China (English)

    吴海波; 郭潮潭; 吴南屏

    2010-01-01

    研制有效的疫苗是预防和控制HIV-1的理想途径.重组活病毒载体疫苗能诱导广泛的细胞和体液免疫应答,并在临床试验中展现出良好的应用前景,已成为当前HIV-1疫苗研究的一个热点.此文就近年来针对HIV-1的各种重组病毒载体疫苗研究进展作了综述.%Developing effective vaccine is the ideal way to prevent and control HIV-1. Recombinant live viral vector vaccine can induce a wide range of cellular and humoral immune response, and shows a good prospect in clinical trials. Therefore, it becomes focus of HIV-1 vaccine research. In this paper, the research advance of HIV-1 recombinant viral vector vaccines in recent years is reviewed.

  14. Recombinant viruses as vaccines against viral diseases

    Directory of Open Access Journals (Sweden)

    A.P.D. Souza

    2005-04-01

    Full Text Available Vaccine approaches to infectious diseases are widely applied and appreciated. Amongst them, vectors based on recombinant viruses have shown great promise and play an important role in the development of new vaccines. Many viruses have been investigated for their ability to express proteins from foreign pathogens and induce specific immunological responses against these antigens in vivo. Generally, gene-based vaccines can stimulate potent humoral and cellular immune responses and viral vectors might be an effective strategy for both the delivery of antigen-encoding genes and the facilitation and enhancement of antigen presentation. In order to be utilized as a vaccine carrier, the ideal viral vector should be safe and enable efficient presentation of required pathogen-specific antigens to the immune system. It should also exhibit low intrinsic immunogenicity to allow for its re-administration in order to boost relevant specific immune responses. Furthermore, the vector system must meet criteria that enable its production on a large-scale basis. Several viral vaccine vectors have thus emerged to date, all of them having relative advantages and limits depending on the proposed application, and thus far none of them have proven to be ideal vaccine carriers. In this review we describe the potential, as well as some of the foreseeable obstacles associated with viral vaccine vectors and their use in preventive medicine.

  15. Recombinant viral-vectored vaccines expressing Plasmodium chabaudi AS apical membrane antigen 1: mechanisms of vaccine-induced blood-stage protection.

    Science.gov (United States)

    Biswas, Sumi; Spencer, Alexandra J; Forbes, Emily K; Gilbert, Sarah C; Holder, Anthony A; Hill, Adrian V S; Draper, Simon J

    2012-05-15

    Apical membrane Ag 1 (AMA1) is one of the leading candidate Ags for inclusion in a subunit vaccine against blood-stage malaria. However, the efficacy of Ab-inducing recombinant AMA1 protein vaccines in phase IIa/b clinical trials remains disappointing. In this article, we describe the development of recombinant human adenovirus serotype 5 and modified vaccinia virus Ankara vectors encoding AMA1 from the Plasmodium chabaudi chabaudi strain AS. These vectors, when used in a heterologous prime-boost regimen in BALB/c mice, are capable of inducing strong transgene-specific humoral and cellular immune responses. We show that this vaccination regimen is protective against a nonlethal P. chabaudi chabaudi strain AS blood-stage challenge, resulting in reduced peak parasitemias. The role of vaccine-induced, AMA1-specific Abs and T cells in mediating the antiparasite effect was investigated by in vivo depletion of CD4(+) T cells and adoptive-transfer studies into naive and immunodeficient mice. Depletion of CD4(+) T cells led to a loss of vaccine-induced protection. Adoptive-transfer studies confirmed that efficacy is mediated by both CD4(+) T cells and Abs functioning in the context of an intact immune system. Unlike previous studies, these results confirm that Ag-specific CD4(+) T cells, induced by a clinically relevant vaccine-delivery platform, can make a significant contribution to vaccine blood-stage efficacy in the P. chabaudi model. Given that cell-mediated immunity may also contribute to parasite control in human malaria, these data support the clinical development of viral-vectored vaccines that induce both T cell and Abs against Plasmodium falciparum blood-stage malaria Ags like AMA1.

  16. Preparation of a recombinant adeno-associated viral vector with a mutation of human factor IX in large scale and its expression in vitro and in vivo

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A series of adeno-associated viral vectors conraining a mutation of human factor IX (hFIXR338A) with different regulation elements were constructed and used to transduce cell lines. The plasmids and the stable transduction cell clones with high expression level of hFIXR338Awere obtained by selecting and optimizing, and then, the recombinant adeno-associated viral vector with hFIXR338Awas prepared via novel rHSV/AAV hybrid virus packaging system on a large scale, which contained the capsid protein genes. A method for producing rAAV-hFIXR338A viral stocks on a large scale and higher fiter was established,which can be used for industrial purpose. The titer of rAAV-hFIXR338A was more than 1.25x1012 particle/mL, and then, a mammalian cell line, C2C12 and the factor IXknock-out mice were transfected with the rAAV-hFIXR338Ain vitro and in vivo. The results show that the high-level expression of rAAV-hFIXR338A was achieved in cell line and hemophilia B mice. It reached at (2551.32±92.14) ng@ (106cells)-1 @ (24 h)-1 in C2C12 cell in vitro and had a peak concentration of 463.28 ng/mL in mice treated with rAAV-hFIX R338A, which was as high as the expression of rAAV-hFIX -wt (2565.76±64.36) ng@ (106 cells)-1@ (24 h)-1 in C2C12 and 453.92 ng/mL in the mice treated with rAAV-hFIX-wt) in vitro and in vivo, there is no any difference between two groups, but the clotting activity of hFIXR338A is about 2.46times higher than that of hFIX-wt. It was first reported that a mutation of human factor IX was used into gene therapy research for hemophilia B, meanwhile, a novel packaging system, rAAV/HSV was used for preparation of rAAV-hFIX R338A on a large scale, which laid the foundation of industrial production for applying rAAV viral stocks to gene therapy clinical trial for hemophilia B mediated with rAAV-hFIX.``

  17. Characterization of cognitive deficits in rats overexpressing human alpha-synuclein in the ventral tegmental area and medial septum using recombinant adeno-associated viral vectors.

    Directory of Open Access Journals (Sweden)

    Hélène Hall

    Full Text Available 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.

  18. Methods of treating Parkinson's disease using viral vectors

    Science.gov (United States)

    Bankiewicz, Krystof; Cunningham, Janet

    2016-11-15

    Methods of delivering viral vectors, particularly recombinant adeno-associated virus (rAAV) virions, to the central nervous system (CNS) using convection enhanced delivery (CED) are provided. The rAAV virions include a nucleic acid sequence encoding a therapeutic polypeptide. The methods can be used for treating CNS disorders such as for treating Parkinson's Disease.

  19. [Kunjin virus replicon--a novel viral vector].

    Science.gov (United States)

    Li, Shihua; Li, Xiaofeng; Qin, E'de; Qin, Chengfeng

    2011-02-01

    Viral replicon is a kind of self-replicating viral RNA sourced from viral genome, which contains viral non-structural genes that are critical for viral genome replication with structural proteins deleted or replaced by foreign genes. Kunjin virus is a member of the Flavivirida family, Flavivirus genus, and Kunjin virus replicon is the first and the clearly defined flavivirus replicon. Kunjun virus replicon has been regarded as an excellent viral vector on account of its high expression, lower cytotoxicity and genetic stability. These unique characteristics of kunjin virus replicons make them suitable for the study of viral genome replication, recombinant proteins production, vaccine development and gene therapy. In this article, recent progress in the development, properties and applications of kunjin virus replicon system was briefly reviewed.

  20. Vaxvec: The first web-based recombinant vaccine vector database and its data analysis.

    Science.gov (United States)

    Deng, Shunzhou; Martin, Carly; Patil, Rasika; Zhu, Felix; Zhao, Bin; Xiang, Zuoshuang; He, Yongqun

    2015-11-27

    A recombinant vector vaccine uses an attenuated virus, bacterium, or parasite as the carrier to express a heterologous antigen(s). Many recombinant vaccine vectors and related vaccines have been developed and extensively investigated. To compare and better understand recombinant vectors and vaccines, we have generated Vaxvec (http://www.violinet.org/vaxvec), the first web-based database that stores various recombinant vaccine vectors and those experimentally verified vaccines that use these vectors. Vaxvec has now included 59 vaccine vectors that have been used in 196 recombinant vector vaccines against 66 pathogens and cancers. These vectors are classified to 41 viral vectors, 15 bacterial vectors, 1 parasitic vector, and 1 fungal vector. The most commonly used viral vaccine vectors are double-stranded DNA viruses, including herpesviruses, adenoviruses, and poxviruses. For example, Vaxvec includes 63 poxvirus-based recombinant vaccines for over 20 pathogens and cancers. Vaxvec collects 30 recombinant vector influenza vaccines that use 17 recombinant vectors and were experimentally tested in 7 animal models. In addition, over 60 protective antigens used in recombinant vector vaccines are annotated and analyzed. User-friendly web-interfaces are available for querying various data in Vaxvec. To support data exchange, the information of vaccine vectors, vaccines, and related information is stored in the Vaccine Ontology (VO). Vaxvec is a timely and vital source of vaccine vector database and facilitates efficient vaccine vector research and development.

  1. Construction, production, and purification of recombinant adenovirus vectors.

    Science.gov (United States)

    Miravet, Susana; Ontiveros, Maria; Piedra, Jose; Penalva, Cristina; Monfar, Mercè; Chillón, Miguel

    2014-01-01

    Recombinant adenoviruses provide a versatile system for gene expression studies and therapeutic applications. In this chapter, a standard procedure for their generation and small-scale production is described. Homologous recombination in E. coli between shuttle plasmids and full-length adenovirus backbones (E1-deleted) is used for the generation of recombinant adenoviral vectors genomes. The adenovirus genomes are then analyzed to confirm their identity and integrity, and further linearized and transfected to generate a recombinant adenoviral vector in permissive human cells. These vectors are then purified by two sequential CsCl gradient centrifugations and subjected to a chromatography step in order to eliminate the CsCl and exchange buffers. Finally, the viral stock is characterized through the quantification of its viral particle content and its infectivity.

  2. Virally vectored vaccine delivery: medical needs, mechanisms, advantages and challenges.

    Science.gov (United States)

    Pinschewer, Daniel D

    2017-08-14

    Vaccines represent one of the most successful chapters in the history of medicine. Over the past decades, the advent of recombinant cDNA technology has enabled the biomedical community to genetically engineer viruses for vaccine delivery purposes. As a starting point, this review evaluates the unmet medical needs, which drive scientists and industry to exploit such fundamentally new technology for human vaccination. The author discusses the molecular functioning, production and safety profile of replication-competent and -deficient viral vector systems, representing two fundamentally distinct classes of "genetic vaccines". Building upon this knowledge, he dissects the immunological mechanisms rendering immune responses to viral vectors qualitatively and quantitatively distinct from those elicited by non-live vaccination approaches. These mechanisms comprise (1) the vectors' innate immune recognition by the host cell, (2) potent priming of CD8+ cytotoxic T cells as a result of dendritic cell targeting and endogenous protein synthesis, (3) conformational antigen display for protective antibody induction as well as (4) prolonged availability of substantial quantities of antigen. Deduced from these features, preferential indications for virally vectored vaccines are discussed, taking into consideration specific medical needs as well as risk-benefit assessments of replicating vector systems. The limitations and challenges in virally vectored vaccination must also be given careful consideration. Pre-existing and vaccination-induced anti-vector immunity can interfere with vaccine immunogenicity and prime-boost vaccination, respectively. Additionally, the requirement for eukaryotic production systems imposes technological as well as regulatory hurdles. Existing strategies to overcome these challenges are outlined. With the recent licensure of the first virally vectored vaccine this review seems timely to herald the introduction of virally vectored vaccines into daily

  3. Methods of treating Parkinson's disease using viral vectors

    Science.gov (United States)

    Bankiewicz, Krys; Cunningham, Janet

    2012-11-13

    Methods of delivering viral vectors, particularly recombinant AAV virions, to the central nervous system (CNS) are provided for the treatment of CNS disorders, particularly those disorders which involve the neurotransmitter dopamine. The methods entail providing rAAV virions that comprise a transgene encoding aromatic amino acid decarboxylase (AADC) and administering the virions to the brain of a mammal using a non-manual pump.

  4. Gene therapy for hemophilia B mediated by recombinant adeno-associated viral vector with hFIXR338A, a high catalytic activity mutation of human coagulation factor IX

    Institute of Scientific and Technical Information of China (English)

    陆华中; 陈立; 王红卫; 伍志坚; 吴小兵; 王学峰; 王鸿利; 卢大儒; 邱信芳; 薛京伦

    2001-01-01

    A mutant human factor IX with arginine at 338 residual changed to alanine (hFIXR338A) by site-directed mutagenesis was introduced into AAV vectors, and a recombinant adeno-associ- ated viral vector containing hFIXR338A, prepared by rHSV/AAV hybrid helper virus system, was directly introduced to the hind leg muscle of factor IX knock out mice. The expression and the biological activity of human factor IX mutant, hFIXR338A, and the immune response against it in the treated mice were assayed and detected. The results showed that (i) the high-level expression of human factor IX mutant protein, hFIXR338A, has been detected in rAAV-hFIXR338A treated hemophilia B mice and lasted more than 15 weeks; (ii) the clotting activity of hFIXR338A in plasma is 34.2%± 5.23%, which is remarkably higher than that of (14.27% ± 3.4%) of wild type hFIX treated mice in the activated partial thromboplastin assay; (iii) immune response against factor IX R338A was absent, with no factor IX mutant protein (hFIXR338A) inhibitors development in the treated mice; and (iv) no local or systemic side-effects and toxicity associated with the gene transfer were found. It demonstrated the potential use of treating hemophilia B by recombinant adeno-associated viral vectors with mutant hFIXR338A gene, an alternative strategy for hemophilia B gene therapy to wild-type human factor IX.

  5. Viral Vectors for in Vivo Gene Transfer

    Science.gov (United States)

    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. [Development of viral vectors and the application for viral entry mechanisms].

    Science.gov (United States)

    Tani, Hideki

    2011-06-01

    Virus is identified as one of the obligate intracellular parasites, which only amplify in cells of specific living things. Viral vectors, which are developed by utilizing these properties, are available in the various fields such as basic research of medical biology or application of gene therapy. Our research group has studied development of viral vectors using properties of baculovirus or vesicular stomatitis virus (VSV). Due to the development of new baculoviral vectors for mammalian cells, it is possible to be more efficient transduction of foreign gene in mammalian cells and animals. Furthermore, pseudotype or recombinant VSV possessing the envelope proteins of hepatitis C virus, Japanese encephalitis virus or baculovirus were constructed, and characteristics of the envelope proteins or entry mechanisms of these viruses were analyzed.

  7. Immunogenicity of viral vector, prime-boost SIV vaccine regimens in infant rhesus macaques: attenuated vesicular stomatitis virus (VSV) and modified vaccinia Ankara (MVA) recombinant SIV vaccines compared to live-attenuated SIV.

    Science.gov (United States)

    Van Rompay, Koen K A; Abel, Kristina; Earl, Patricia; Kozlowski, Pamela A; Easlick, Juliet; Moore, Joseph; Buonocore-Buzzelli, Linda; Schmidt, Kimberli A; Wilson, Robert L; Simon, Ian; Moss, Bernard; Rose, Nina; Rose, John; Marthas, Marta L

    2010-02-10

    In a previously developed infant macaque model mimicking HIV infection by breast-feeding, we demonstrated that intramuscular immunization with recombinant poxvirus vaccines expressing simian immunodeficiency virus (SIV) structural proteins provided partial protection against infection following oral inoculation with virulent SIV. In an attempt to further increase systemic but also local antiviral immune responses at the site of viral entry, we tested the immunogenicity of different orally administered, replicating vaccines. One group of newborn macaques received an oral prime immunization with a recombinant vesicular stomatitis virus expressing SIVmac239 gag, pol and env (VSV-SIVgpe), followed 2 weeks later by an intramuscular boost immunization with MVA-SIV. Another group received two immunizations with live-attenuated SIVmac1A11, administered each time both orally and intravenously. Control animals received mock immunizations or non-SIV VSV and MVA control vectors. Analysis of SIV-specific immune responses in blood and lymphoid tissues at 4 weeks of age demonstrated that both vaccine regimens induced systemic antibody responses and both systemic and local cell-mediated immune responses. The safety and immunogenicity of the VSV-SIVgpe+MVA-SIV immunization regimen described in this report provide the scientific incentive to explore the efficacy of this vaccine regimen against virulent SIV exposure in the infant macaque model.

  8. Mucosal immunization with recombinant adenoviral vectors expressing murine gammaherpesvirus-68 genes M2 and M3 can reduce latent viral load

    DEFF Research Database (Denmark)

    Hoegh-Petersen, Mette; Thomsen, Allan R; Christensen, Jan P

    2009-01-01

    of the gammaherpesvirinae speaks against using a similar approach in humans. DNA immunization with plasmids encoding the MHV-68 genes M2 or M3 caused a reduction in either acute or early latent viral load, respectively, but neither immunization had an effect at times later than 14 days post-infection. Adenovirus......-based vaccines are substantially more immunogenic than DNA vaccines and can be applied to induce mucosal immunity. Here we show that a significant reduction of the late viral load in the spleens, at 60 days post-infection, was achieved when immunizing mice both intranasally and subcutaneously with adenoviral...

  9. Viral vector-based prime-boost immunization regimens : a possible involvement of T-cell competition

    NARCIS (Netherlands)

    de Mare, A.; Lambeck, A. J. A.; Regts, J.; van Dam, G. M.; Nijman, H. W.; Snippe, H.; Wilschut, J.; Daemen, T.

    2008-01-01

    Vaccination with recombinant viral vectors may be impeded by preexisting vector-specific immunity or by vector-specific immunity induced during the priming immunization. It is assumed that virus-neutralizing antibodies represent the principal effector mechanism of vector-specific immunity, while kil

  10. Gene therapy for hemophilia B mediated by recombinant adeno-associated viral vector with hFIXR338A, a high catalytic activity mutation of human coagulation factor IX

    Institute of Scientific and Technical Information of China (English)

    LU; Huazhong; (

    2001-01-01

    [1]Chang, J., Jin, J., Lollar, P. et al., Changing residue 338 in human factor IX from arginine to alanine causes an increase in catalytic activity, J. Bio. Chem., 1998, 273 (20): 12089-12094.[2]Lai, L., Chen, L., Zhou, H. et al., Clinical phenotype and genetic stability of factor IX gene knock out mice, J. Fudan Uni., 1999, 38 (4): 435-438.[3]Wu, Z. J., Wu, X. B., Hou, Y. D., Generation of a recombinant herps simplex virus which can provide packaging function for recombinant adeno-associated virus, Chinese Sci. Bull., 1999, 44 (8): 715-719.[4]Snyder, R. O., Miao, C. H., Patijn, G. A. et al., Persistent and therapeutic concentrations of human factor IX in mice after hepatic gene transfer of recombinant AAV vectors, Nat. Genet., 1997, 16 (3): 270-276.[5]Lai, L. H., Chen, L., Wang, J. M. et al., Skeletal muscle-specific expression of human blood coagulation factor IX rescues factor IX deficiency mouse by AAV-mediated gene transfer, Science in China, Ser. C, 1999, 42 (6): 628-634.[6]Snyder, R. O., Miao, C., Meuse, L. et al., Correction of hemophilia B in canine and murine models using recombinant adeno-associated viral vectors, Nat. Med., 1999, 5 (1): 64-70.[7]Kung, S. H., Hagstrom, J. N., Cass, D. et al., Human factor IX corrects the bleeding diathesis of mice with hemophilia B, Blood, 1998, 91(3): 784-790.[8]Hirt, B., Selective extraction of polyoma DNA from infected mouse cell culture, J. Mol. Biol., 1967, 26: 365-369.[9]Sambrook, J., Fritsch, E., Maniatis, T., Molecular Cloning: A Laboratory Manual, New York: Cold Spring Harbor Laboratory Press, 1989, 6, 20-21.[10]Chao, H., Samulski, R. J., Bellinger, D. A. et al., Persistent expression of canine factor IX in hemophilia B canines, Gene Ther., 1999, 6: 1695-1704.[11]Kaufman, R. J., Advances toward gene therapy for hemophilia at the millennium, Hum. Gene Ther., 1999, 10 (13): 2091-2107.[12]Lu, D. R., Zhou, J. M., Zheng, B. et al., Stage I clinical trial of gene

  11. Replicon RNA Viral Vectors as Vaccines

    Science.gov (United States)

    Lundstrom, Kenneth

    2016-01-01

    Single-stranded RNA viruses of both positive and negative polarity have been used as vectors for vaccine development. In this context, alphaviruses, flaviviruses, measles virus and rhabdoviruses have been engineered for expression of surface protein genes and antigens. Administration of replicon RNA vectors has resulted in strong immune responses and generation of neutralizing antibodies in various animal models. Immunization of mice, chicken, pigs and primates with virus-like particles, naked RNA or layered DNA/RNA plasmids has provided protection against challenges with lethal doses of infectious agents and administered tumor cells. Both prophylactic and therapeutic efficacy has been achieved in cancer immunotherapy. Moreover, recombinant particles and replicon RNAs have been encapsulated by liposomes to improve delivery and targeting. Replicon RNA vectors have also been subjected to clinical trials. Overall, immunization with self-replicating RNA viruses provides high transient expression levels of antigens resulting in generation of neutralizing antibody responses and protection against lethal challenges under safe conditions. PMID:27827980

  12. Advances in Non-Viral DNA Vectors for Gene Therapy

    Directory of Open Access Journals (Sweden)

    Cinnamon L. Hardee

    2017-02-01

    Full Text Available Uses of viral vectors have thus far eclipsed uses of non-viral vectors for gene therapy delivery in the clinic. Viral vectors, however, have certain issues involving genome integration, the inability to be delivered repeatedly, and possible host rejection. Fortunately, development of non-viral DNA vectors has progressed steadily, especially in plasmid vector length reduction, now allowing these tools to fill in specifically where viral or other non-viral vectors may not be the best options. In this review, we examine the improvements made to non-viral DNA gene therapy vectors, highlight opportunities for their further development, address therapeutic needs for which their use is the logical choice, and discuss their future expansion into the clinic

  13. Advances in Non-Viral DNA Vectors for Gene Therapy

    Science.gov (United States)

    Hardee, Cinnamon L.; Arévalo-Soliz, Lirio Milenka; Hornstein, Benjamin D.; Zechiedrich, Lynn

    2017-01-01

    Uses of viral vectors have thus far eclipsed uses of non-viral vectors for gene therapy delivery in the clinic. Viral vectors, however, have certain issues involving genome integration, the inability to be delivered repeatedly, and possible host rejection. Fortunately, development of non-viral DNA vectors has progressed steadily, especially in plasmid vector length reduction, now allowing these tools to fill in specifically where viral or other non-viral vectors may not be the best options. In this review, we examine the improvements made to non-viral DNA gene therapy vectors, highlight opportunities for their further development, address therapeutic needs for which their use is the logical choice, and discuss their future expansion into the clinic. PMID:28208635

  14. Biosafety of recombinant adeno-associated virus vectors.

    Science.gov (United States)

    Dismuke, David J; Tenenbaum, Liliane; Samulski, R Jude

    2013-12-01

    It is hoped that the use of gene transfer technology to treat both monogenetic and acquired diseases may soon become a common therapy option in medicine. For gene therapy to achieve this objective, any gene delivery method will have to meet several criteria, including ease of manufacturing, efficient gene transfer to target tissue, long-term gene expression to alleviate the disease, and most importantly safety in patients. Viral vectors are an attractive choice for use in gene therapy protocols due to their relative efficiency in gene delivery. Since there is inherent risk in using viruses, investigators in the gene therapy community have devoted extensive efforts toward reengineering viral vectors for enhance safety. Here we review the approaches and technologies that are being evaluated for the use of recombinant vectors based upon adeno-associated virus (AAV) in the treatment of a variety of human diseases. AAV is currently the only known human DNA virus that is non-pathogenic and AAV-based vectors are classified as Risk Group 1 agents for all laboratory and animal studies carried out in the US. Although its apparent safety in natural infection and animals appears well documented, we examine the accumulated knowledge on the biology and vectorology of AAV, lessons learned from gene therapy clinical trials, and how this information is impacting current vector design and manufacturing with an overall emphasis on biosafety.

  15. Viral vectors for targeting the canine retina: a review.

    Science.gov (United States)

    Petersen-Jones, Simon M

    2012-09-01

    Clinical trials are currently underway using gene therapy to treat retinal disease such as Leber congenital amaurosis (LCA). Viral vectors that have been utilized to target retinal cells include adenoviruses, lentiviruses, and recombinant adeno-associated viruses (rAAV). Of the three classes, rAAV vectors show the greatest promise for retinal gene therapy. Recent developments in virus technology such as the development of hybrid and capsid mutant rAAV vectors mean that specific retinal cells can be targeted and faster stronger transgene expression is now possible compared to that achieved with the first generation of vectors. Gene therapy trials in dogs have been very important in the development of therapy for RPE65 LCA which is currently in phase I/II clinical trials in humans. Recent successes in using gene therapy to treat canine achromatopsia, X-linked progressive retinal atrophy (PRA) and the more severe rapid degenerations such as rod-cone dysplasia type 3 may lead also to the translation to human clinical trials. Dogs have played and continue to play an important role as animal models for proof-of-concept studies of retinal gene therapy. As modifications and improvements in gene therapy protocols are made from experience gathered from human clinical trials perhaps gene therapy for the treatment of canine clinical patients will become available to veterinary ophthalmologists. © 2012 American College of Veterinary Ophthalmologists.

  16. Methods of treating Parkinson's disease using viral vectors

    Energy Technology Data Exchange (ETDEWEB)

    Bankiewicz, Krystof; Cunningham, Janet

    2016-11-15

    Methods of delivering viral vectors, particularly recombinant adeno-associated virus (rAAV) virions, to the central nervous system (CNS) using convection enhanced delivery (CED) are provided. The rAAV virions include a nucleic acid sequence encoding a therapeutic polypeptide. The methods can be used for treating CNS disorders such as for treating Parkinson's Disease.

  17. Intracranial Injection of Adeno-associated Viral Vectors

    OpenAIRE

    Lowery, Rebecca L.; Ania K Majewska

    2010-01-01

    Intracranial injection of viral vectors engineered to express a fluorescent protein is a versatile labeling technique for visualization of specific subsets of cells in different brain regions both in vivo and in brain sections. Unlike the injection of fluorescent dyes, viral labeling offers targeting of individual cell types and is less expensive and time consuming than establishing transgenic mouse lines. In this technique, an adeno-associated viral (AAV) vector is injected intracranially us...

  18. Development of non-defective recombinant densovirus vectors for microRNA delivery in the invasive vector mosquito, Aedes albopictus

    Science.gov (United States)

    Liu, Peiwen; Li, Xiaocong; Gu, Jinbao; Dong, Yunqiao; Liu, Yan; Santhosh, Puthiyakunnon; Chen, Xiaoguang

    2016-01-01

    We previously reported that mosquito densoviruses (MDVs) are potential vectors for delivering foreign nucleic acids into mosquito cells. However, considering existing expression strategies, recombinant viruses would inevitably become replication-defective viruses and lose their ability for secondary transmission. The packaging limitations of the virion represent a barrier for the development of MDVs for viral paratransgenesis or as high-efficiency bioinsecticides. Herein, we report the development of a non-defective recombinant Aedes aegypti densovirus (AaeDV) miRNA expression system, mediated by an artificial intron, using an intronic miRNA expression strategy. We demonstrated that this recombinant vector could be used to overexpress endogenous miRNAs or to decrease endogenous miRNAs by generating antisense sponges to explore the biological functions of miRNAs. In addition, the vector could express antisense-miRNAs to induce efficient gene silencing in vivo and in vitro. The recombinant virus effectively self-replicated and retained its secondary transmission ability, similar to the wild-type virus. The recombinant virus was also genetically stable. This study demonstrated the first construction of a non-defective recombinant MDV miRNA expression system, which represents a tool for the functional analysis of mosquito genes and lays the foundation for the application of viral paratransgenesis for dengue virus control. PMID:26879823

  19. Development of non-defective recombinant densovirus vectors for microRNA delivery in the invasive vector mosquito, Aedes albopictus.

    Science.gov (United States)

    Liu, Peiwen; Li, Xiaocong; Gu, Jinbao; Dong, Yunqiao; Liu, Yan; Santhosh, Puthiyakunnon; Chen, Xiaoguang

    2016-02-16

    We previously reported that mosquito densoviruses (MDVs) are potential vectors for delivering foreign nucleic acids into mosquito cells. However, considering existing expression strategies, recombinant viruses would inevitably become replication-defective viruses and lose their ability for secondary transmission. The packaging limitations of the virion represent a barrier for the development of MDVs for viral paratransgenesis or as high-efficiency bioinsecticides. Herein, we report the development of a non-defective recombinant Aedes aegypti densovirus (AaeDV) miRNA expression system, mediated by an artificial intron, using an intronic miRNA expression strategy. We demonstrated that this recombinant vector could be used to overexpress endogenous miRNAs or to decrease endogenous miRNAs by generating antisense sponges to explore the biological functions of miRNAs. In addition, the vector could express antisense-miRNAs to induce efficient gene silencing in vivo and in vitro. The recombinant virus effectively self-replicated and retained its secondary transmission ability, similar to the wild-type virus. The recombinant virus was also genetically stable. This study demonstrated the first construction of a non-defective recombinant MDV miRNA expression system, which represents a tool for the functional analysis of mosquito genes and lays the foundation for the application of viral paratransgenesis for dengue virus control.

  20. High density recombinant AAV particles are competent vectors for in vivo transduction

    Science.gov (United States)

    Recombinant adeno-associated viral (rAAV) vectors have recently achieved clinical successes in human gene therapy. However, the commonly observed heavier particles found in AAV preparations have traditionally been ignored due to its low in vitro infectivity. In this study, we systemically compared t...

  1. Gene therapy for haemophilia...yes, but...with non-viral vectors?

    Science.gov (United States)

    Liras, A; Olmedillas, S

    2009-05-01

    High-purity plasma-derived and recombinant factors are currently safe and efficient treatment for haemophilia. The mid-term future of haemophilia treatment will involve the use of modified recombinant factors to achieve advantages such as decreased immunogenicity in inhibitor formation and enhanced efficacy as a result of their longer half-life. In the long-term, gene therapy and cell therapy strategies will have to be considered. Achievements in cell therapy to date have been using embryonic stem cells and hepatic sinusoidal endothelial cells. Current gene therapy strategies for haemophilia are based on gene transfer using adeno-associated viruses and non-viral vectors. Gene therapy for haemophilia is justified because it is a chronic disease and because a very regular factor infusion is required that may involve fatal risks and because it is very expensive. Haemophilia is a very good candidate for use of gene therapy protocols because it is a monogenic disease, and even low expression is able to achieve reversion from a severe to a moderate phenotype. The current trends in haemophilia using adeno-associated viral vectors are safe but also involve immunogenicity problems. The other alternatives are non-viral vectors. There have been in recent years relevant advances in non-viral transfection that raise hope for considering this possibility. Several research groups are opting for this experimental alternative. An expression over 5%, representing a moderate phenotype, for a few months with a high safety, regarding vector, transfected cells, and implantation procedure, would already be a great success. This may represent an intermediate protocol in which the expression levels and times obtained are lower and shorter respectively as compared to viral vectors, but which provide a potential greater patient safety. This may more readily win acceptance among both patients and haematologists because fatal events in the past due to HIV/HCV infection may constrain the

  2. Influence of HEK293 metabolism on the production of viral vectors and vaccine.

    Science.gov (United States)

    Petiot, Emma; Cuperlovic-Culf, Miroslava; Shen, Chun Fang; Kamen, Amine

    2015-11-01

    Mammalian cell cultures are increasingly used for the production of complex biopharmaceuticals including viral vectors and vaccines. HEK293 is the predominant cell line used for the transient expression of recombinant proteins and a well-established system for the production of viral vectors. Understanding metabolic requirements for high productivity in HEK293 cells remains an important area of investigation. Many authors have presented approaches for increased productivity through optimization of cellular metabolism from two distinct perspectives. One is a non-targeted approach, which is directed to improving feeding strategies by addition of exhausted or critical substrates and eventually removal of toxic metabolites. Alternatively, a targeted approach has attempted to identify specific targets for optimization through better understanding of the cellular metabolism under different operating conditions. This review will present both approaches and their successes with regards to improvement of viral production in HEK293 cells outlining the key relations between HEK293 cell metabolism and viral vector productivity. Also, we will summarize the current knowledge on HEK293 metabolism indicating remaining issues to address and problems to resolve to maximize the productivity of viral vectors in HEK293 cells.

  3. Non viral vectors in gene therapy- an overview.

    Science.gov (United States)

    Ramamoorth, Murali; 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".

  4. Expression of Hepatitis B Virus Surface Antigen Gene in Cultured Cells by Using Recombinant Plasmid Vectors

    OpenAIRE

    Siddiqui, Aleem

    1983-01-01

    By using a new host-vector system, expression of the gene coding for hepatitis B surface antigen has been studied. A subgenomic fragment of cloned hepatitis B viral DNA was inserted into the plasmid vector pSV010. Transfection of COS cells with the recombinant plasmid vector containing hepatitis sequences leads to the synthesis of hepatitis B surface antigen, which is released in the culture medium in the form of 22-nm particles similar to those found in the sera of hepatitis carriers.

  5. Plant viral vectors based on tobamoviruses.

    Science.gov (United States)

    Yusibov, V; Shivprasad, S; Turpen, T H; Dawson, W; Koprowski, H

    1999-01-01

    The potential of plant virus-based transient expression vectors is substantial. One objective is the production of large quantities of foreign peptides or proteins. At least one commercial group (Biosource Technologies) is producing large quantities of product in the field, has built factories to process truck-loads of material and soon expects to market virus-generated products. In the laboratory, large amounts of protein have been produced for structural or biochemical analyses. An important aspect of producing large amounts of a protein or peptide is to make the product easily purifiable. This has been done by attaching peptides or proteins to easily purified units such as virion particles or by exporting proteins to the apoplast so that purification begins with a highly enriched product. For plant molecular biology, virus-based vectors have been useful in identifying previously unknown genes by overexpression or silencing or by expression in different genotypes. Also, foreign peptides fused to virions are being used as immunogens for development of antisera for experimental use or as injected or edible vaccines for medical use. As with liposomes and microcapsules, plant cells and plant viruses are also expected to provide natural protection for the passage of antigen through the gastrointestinal tract. Perhaps the greatest advantage of plant virus-based transient expression vectors is their host, plants. For the production of large amounts of commercial products, plants are one of the most economical and productive sources of biomass. They also present the advantages of lack of contamination with animal pathogens, relative ease of genetic manipulation and the presence eukaryotic protein modification machinery.

  6. A comparative study on the immunotherapeutic efficacy of recombinant Semliki Forest virus and adenovirus vector systems in a murine model for cervical cancer

    NARCIS (Netherlands)

    Riezebos-Brilman, A.; Walczak, M.; Regts, J.; Rots, Mg; Kamps, G.; Dontje, B.; Haisma, Hy; Wilschut, J.; Daemen, T.

    2007-01-01

    Currently, various therapeutic strategies are being explored as a potential means to immunize against metastatic malignant cells or even primary tumours. Using recombinant viral vectors systems or protein-based immunization approaches, we are developing immunotherapeutic strategies against cervical

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

    Science.gov (United States)

    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…

  8. Recombinant adenovirus vectors with knobless fibers for targeted gene transfer

    NARCIS (Netherlands)

    van Beusechem, VW; van Rijswijk, ALCT; van Es, HHG; Haisma, HJ; Pinedo, HM; Gerritsen, WR

    2000-01-01

    Adenoviral vector systems for gene therapy can be much improved by targeting vectors to specific cell types. This requires both the complete ablation of native adenovirus tropism and the introduction of a novel binding affinity in the viral capsid. We reasoned that these requirements could be fulfil

  9. Viral vectors for gene transfer: current status of gene therapeutics.

    Science.gov (United States)

    Heilbronn, Regine; Weger, Stefan

    2010-01-01

    Gene therapy for the correction of inherited or acquired disease has gained increasing importance in recent years. Successful treatment of children suffering from severe combined immunodeficiency (SCID) was achieved using retrovirus vectors for gene transfer. Encouraging improvements of vision were reported in a genetic eye disorder (LCA) leading to early childhood blindness. Adeno-associated virus (AAV) vectors were used for gene transfer in these trials. This chapter gives an overview of the design and delivery of viral vectors for the transport of a therapeutic gene into a target cell or tissue. The construction and production of retrovirus, lentivirus, and AAV vectors are covered. The focus is on production methods suitable for biopharmaceutical upscaling and for downstream processing. Quality control measures and biological safety considerations for the use of vectors in clinical trials are discussed.

  10. Fusion Wheat Histone H4 Protein Increases Transfection Efficiency of Non-viral DNA Vector

    Institute of Scientific and Technical Information of China (English)

    WANG Chun-yan; ZHANG Yu-jing

    2011-01-01

    The lack of efficient and non-toxic gene delivery, preferably with non-viral DNA vectors, is generally regarded as a major limitation for gene therapy. In this study, a wheat histone H4 gene was cloned from Triticum aestivum, sequenced, modified and expressed in E. coli. The wheat histone H4 gene and reconstructed H4TL gene encoded wheat histone H4 and a recombinant protein of 141 amino acids with an approximate molecular weight of 15500. Gel electrophoresis mobility shift assays demonstrated that the purified protein had high affinity for DNA.Most significantly, the complex of plasmid pEGFP/Cl with H4TL was transfected with increased efficiency into MCF-7, HO8910, LNCap, A549 and HeLa cells in vitro. These results demonstrate that the targeting of non-viral vectors to tumor-specific receptors provides a cheap, simple and highly efficient tool for gene delivery.

  11. Construction and expression of recombined human AFP eukaryotic expression vector

    Institute of Scientific and Technical Information of China (English)

    Li-Wang Zhang; Yang-Lin Pan; Stephen M Festein; Jun Ren; Liang Zhang; Hong-Mei Zhang; Bin Jin; Bo-Rong Pan; Xiao-Ming Si; Yan-Jun Zhang; Zhong-Hua Wang

    2003-01-01

    AIM: To construct a recombined human AFP eukaryotic expression vector for the purpose of gene therapy and target therapy of hepatocellular carcinoma (HCC).METHODS: The full length AFP-cDNA of prokaryotic vector was digested, and subcloned to the multi-clony sites of the eukaryotic vector. The constructed vector was confirmed by enzymes digestion and electrophoresis, and the product expressed was detected by electrochemiluminescence and immunofluorescence methods.RESULTS: The full length AFP-cDNA successfully cloned to the eukaryotic vector through electrophoresis, 0.9723 IU/ml AFP antigen was detected in the supernatant of AFPCHO by electrochemiluminescence method. Compared with the control groups, the differences were significant (P<0.05).AFP antigen molecule was observed in the plasma of AFPCHO by immunofluorescence staining.CONCLUSION: The recombined human AFP eukaryotic expression vector can express in CHO cell line. It provides experimental data for gene therapy and target therapy of hepatocellular carcinoma.

  12. Safety and immunogenicity of myxoma virus as a new viral vector for small ruminants.

    Science.gov (United States)

    Pignolet, Béatrice; Boullier, Séverine; Gelfi, Jacqueline; Bozzetti, Marjorie; Russo, Pierre; Foulon, Eliane; Meyer, Gilles; Delverdier, Maxence; Foucras, Gilles; Bertagnoli, Stéphane

    2008-06-01

    Myxoma virus (MYXV), a leporide-specific poxvirus, represents an attractive candidate for the generation of safe and non-replicative vaccine vectors for other species. With the aim of developing new recombinant vaccines for ruminants, we evaluated the safety and the immunogenicity of recombinant MYXV in sheep. In vitro studies indicated that ovine primary fibroblasts were not permissive for MYXV and that infection of ovine peripheral blood mononuclear cells occurred at a low rate. Although non-specific activation significantly improved the susceptibility of lymphocytes, MYXV infection remained abortive. Histological and immunohistochemical examination at the inoculation sites revealed the development of an inflammatory process and allowed the detection of sparse infected cells in the dermis. In addition, inoculated sheep developed an antibody response directed against MYXV and the product of the transgene. Overall, these results provide the first line of evidence on the potential of MYXV as a viral vector for ruminants.

  13. Herpes simplex virus type 1-derived recombinant and amplicon vectors.

    Science.gov (United States)

    Fraefel, Cornel; Marconi, Peggy; Epstein, Alberto L

    2011-01-01

    Herpes simplex virus type 1 (HSV-1) is a human pathogen whose lifestyle is based on a long-term dual interaction with the infected host, being able to establish both lytic and latent infections. The virus genome is a 153 kbp double-stranded DNA molecule encoding more than 80 genes. The interest of HSV-1 as gene transfer vector stems from its ability to infect many different cell types, both quiescent and proliferating cells, the very high packaging capacity of the virus capsid, the outstanding neurotropic adaptations that this virus has evolved, and the fact that it never integrates into the cellular chromosomes, thus avoiding the risk of insertional mutagenesis. Two types of vectors can be derived from HSV-1, recombinant vectors and amplicon vectors, and different methodologies have been developed to prepare large stocks of each type of vector. This chapter summarizes (1) the two approaches most commonly used to prepare recombinant vectors through homologous recombination, either in eukaryotic cells or in bacteria, and (2) the two methodologies currently used to generate helper-free amplicon vectors, either using a bacterial artificial chromosome (BAC)-based approach or a Cre/loxP site-specific recombination strategy.

  14. Recombinant protein-based viral disease diagnostics in veterinary medicine.

    Science.gov (United States)

    Balamurugan, Vinayagamurthy; Venkatesan, Gnanavel; Sen, Arnab; Annamalai, Lakshmanan; Bhanuprakash, Veerakyathappa; Singh, Raj Kumar

    2010-09-01

    Identification of pathogens or antibody response to pathogens in human and animals modulates the treatment strategies for naive population and subsequent infections. Diseases can be controlled and even eradicated based on the epidemiology and effective prophylaxis, which often depends on development of efficient diagnostics. In addition, combating newly emerging diseases in human as well as animal healthcare is challenging and is dependent on developing safe and efficient diagnostics. Detection of antibodies directed against specific antigens has been the method of choice for documenting prior infection. Other than zoonosis, development of inexpensive vaccines and diagnostics is a unique problem in animal healthcare. The advent of recombinant DNA technology and its application in the biotechnology industry has revolutionized animal healthcare. The use of recombinant DNA technology in animal disease diagnosis has improved the rapidity, specificity and sensitivity of various diagnostic assays. This is because of the absence of host cellular proteins in the recombinant derived antigen preparations that dramatically decrease the rate of false-positive reactions. Various recombinant products are used for disease diagnosis in veterinary medicine and this article discusses recombinant-based viral disease diagnostics currently used for detection of pathogens in livestock and poultry.

  15. Rewiring carotenoid biosynthesis in plants using a viral vector

    Science.gov (United States)

    Majer, Eszter; Llorente, Briardo; Rodríguez-Concepción, Manuel; Daròs, José-Antonio

    2017-01-01

    Plants can be engineered to sustainably produce compounds of nutritional, industrial or pharmaceutical relevance. This is, however, a challenging task as extensive regulation of biosynthetic pathways often hampers major metabolic changes. Here we describe the use of a viral vector derived from Tobacco etch virus to express a whole heterologous metabolic pathway that produces the health-promoting carotenoid lycopene in tobacco tissues. The pathway consisted in three enzymes from the soil bacteria Pantoea ananatis. Lycopene is present at undetectable levels in chloroplasts of non-infected leaves. In tissues infected with the viral vector, however, lycopene comprised approximately 10% of the total carotenoid content. Our research further showed that plant viruses that express P. ananatis phytoene synthase (crtB), one of the three enzymes of the heterologous pathway, trigger an accumulation of endogenous carotenoids, which together with a reduction in chlorophylls eventually result in a bright yellow pigmentation of infected tissues in various host-virus combinations. So, besides illustrating the potential of viral vectors for engineering complex metabolic pathways, we also show a yellow carotenoid-based reporter that can be used to visually track infection dynamics of plant viruses either alone or in combination with other visual markers. PMID:28139696

  16. Construction and Expression of Human PTEN Tumor Suppressor Gene Recombinant Adenovirus Vector

    Institute of Scientific and Technical Information of China (English)

    CHEN Qingyong; WANG Chunyou; CHEN Daoda; CHEN Jianying; JIANG Chunfang; ZHENG Hai

    2006-01-01

    The recombinant defective adenovirus vector carrying human PTEN tumor suppres sor gene was constructed by using AdEasy-1 system and its expression was detected in human breast cancer cell line MDA-MB-468. Human PTEN cDNA was cloned into adenovirus shuttle plasmid pAdTrack-CMV to generate a recombinant plasmid pAdTrack-CMV-PTEN, then homologeous recombination was carried out in the E. coli BJ5183 by contransforming linearized shuttle vector with adenovirus backbone plasmid pAdEasy-1. The newly recombined defective adenovirus vector AdPTEN containing green fluorescent protein (GFP) was packaged and propagated in 293 cells. After being purified by cesium chloride gradient centrifugation, the adenovirus was transfected into human breast cancer cell line MDA-MB-468 in vitro. The expression of PTEN mRNA and protein in infected human breast cancer cell line MDA-MB-468 was detected by RT-PCR and Western blot respectively. The recombinant defective adenovirus vector carrying PTEN gene was constructed successfully. The viral titer of purified adenovirus was 2.5×1010 pfu/mL, and about 70 % breast cancer cells were infected with Ad PTEN when multiplicity of infection (MOI) reached 50. The exogenous PTEN mRNA and protein were expressed in MDA-MB-468 cells infected with Ad-PTEN by RT-PCR and Western blot. The recombinant defective adenovirus vector of PTEN gene was constructed successfully using AdEasy-1 system rapidly, which paved a sound foundation for gene study of breast cancer.

  17. Transgene expression in Penaeus monodon cells: evaluation of recombinant baculoviral vectors with shrimp specific hybrid promoters.

    Science.gov (United States)

    Puthumana, Jayesh; Philip, Rosamma; Bright Singh, I S

    2016-08-01

    It has been realized that shrimp cell immortalization may not be accomplished without in vitro transformation by expressing immortalizing gene in cells. In this process, efficiency of transgene expression is confined to the ability of vectors to transmit gene of interests to the genome. Over the years, unavailability of such vectors has been hampering application of such a strategy in shrimp cells. We report the use of recombinant baculovirus mediated transduction using hybrid promoter system for transgene expression in lymphoid cells of Penaeus monodon. Two recombinant baculovirus vectors with shrimp viral promoters (WSSV-Ie1 and IHHNV-P2) were constructed (BacIe1-GFP and BacP2-GFP) and green fluorescent protein (GFP) used as the transgene. The GFP expression in cells under the control of hybrid promoters, PH-Ie1 or PH-P2, were analyzed and confirmed in shrimp cells. The results indicate that the recombinant baculovirus with shrimp specific viral promoters (hybrid) can be employed for delivery of foreign genes to shrimp cells for in vitro transformation.

  18. A viral protease relocalizes in the presence of the vector to promote vector performance

    Science.gov (United States)

    Bak, Aurélie; Cheung, Andrea L.; Yang, Chunling; Whitham, Steven A.; Casteel, Clare L.

    2017-01-01

    Vector-borne pathogens influence host characteristics relevant to host–vector contact, increasing pathogen transmission and survival. Previously, we demonstrated that infection with Turnip mosaic virus, a member of one of the largest families of plant-infecting viruses, increases vector attraction and reproduction on infected hosts. These changes were due to a single viral protein, NIa-Pro. Here we show that NIa-Pro responds to the presence of the aphid vector during infection by relocalizing to the vacuole. Remarkably, vacuolar localization is required for NIa-Pro's ability to enhance aphid reproduction on host plants, vacuole localization disappears when aphids are removed, and this phenomenon occurs for another potyvirus, Potato virus Y, suggesting a conserved role for the protein in vector–host interactions. Taken together, these results suggest that potyviruses dynamically respond to the presence of their vectors, promoting insect performance and transmission only when needed. PMID:28205516

  19. Adeno-associated viral vector serotypes 1 and 5 targeted to the neonatal rat and pig striatum induce widespread transgene expression in the forebrain

    DEFF Research Database (Denmark)

    Kornum, Birgitte R; Stott, Simon R W; Mattsson, Bengt

    2010-01-01

    Viral vector-mediated gene transfer has emerged as a powerful means to target transgene expression in the central nervous system. Here we characterized the efficacy of serotypes 1 and 5 recombinant adeno-associated virus (rAAV) vectors encoding green fluorescent protein (GFP) after stereotaxic....... Our results show that striatal delivery of rAAV5 vectors in the neonatal brain represents a useful tool to express genes of interest both in the basal ganglia and the neocortex. Furthermore, we apply, for the first time, viral vector-mediated gene transfer to the pig brain providing the opportunity...

  20. Non-viral vectors for gene-based therapy.

    Science.gov (United States)

    Yin, Hao; Kanasty, Rosemary L; Eltoukhy, Ahmed A; Vegas, Arturo J; Dorkin, J Robert; Anderson, Daniel G

    2014-08-01

    Gene-based therapy is the intentional modulation of gene expression in specific cells to treat pathological conditions. This modulation is accomplished by introducing exogenous nucleic acids such as DNA, mRNA, small interfering RNA (siRNA), microRNA (miRNA) or antisense oligonucleotides. Given the large size and the negative charge of these macromolecules, their delivery is typically mediated by carriers or vectors. In this Review, we introduce the biological barriers to gene delivery in vivo and discuss recent advances in material sciences, nanotechnology and nucleic acid chemistry that have yielded promising non-viral delivery systems, some of which are currently undergoing testing in clinical trials. The diversity of these systems highlights the recent progress of gene-based therapy using non-viral approaches.

  1. Production of recombinant snakehead rhabdovirus: the NV protein is not required for viral replication.

    Science.gov (United States)

    Johnson, M C; Simon, B E; Kim, C H; Leong, J A

    2000-03-01

    Snakehead rhabdovirus (SHRV) affects warm water fish in Southeast Asia and belongs to the genus Novirhabdovirus by virtue of its nonvirion gene (NV). Because SHRV grows best at temperatures between 28 and 31 degrees C, we were able to use the T7 expression system to produce viable recombinant SHRV from a cloned cDNA copy of the viral genome. Expression of a positive-strand RNA copy of the 11, 550-nucleotide SHRV genome along with the viral nucleocapsid (N), phosphoprotein (P), and polymerase (L) proteins resulted in the generation of infectious SHRV in cells preinfected with a vaccinia virus vector for T7 polymerase expression. Recombinant virus production was verified by detection of a unique restriction site engineered into the SHRV genome between the NV and L genes. Since we were now able to begin examining the function of the NV gene, we constructed a recombinant virus containing a nonsense mutation located 22 codons into the coding sequence of the NV protein. The NV knockout virus was produced at a concentration as high as that of wild-type virus in cultured fish cells, and the resulting virions appeared to be identical to the wild-type virions in electron micrographs. These initial studies suggest that NV has no critical function in SHRV replication in cultured fish cells.

  2. Recombination-ready Sindbis replicon expression vectors for transgene expression

    Directory of Open Access Journals (Sweden)

    Olson Ken E

    2007-10-01

    Full Text Available Abstract Background Sindbis viruses have been widely used as tools to study gene function in cells. Despite the utility of these systems, the construction and production of alphavirus replicons is time consuming and inefficient due to potential additional restriction sites within the insert region and lack of directionality for insert ligation. In this report, we present a system useful for producing recombinant Sindbis replicons that uses lambda phage recombination technology to rapidly and specifically construct replicon expression plasmids that contain insert regions in the desired orientation. Results Recombination of the gene of interest with the replicon plasmid resulted in nearly 100% recombinants, each of which contained a correctly orientated insert. Replicons were easily produced in cell culture and packaged into pseudo-infectious viral particles. Insect and mammalian cells infected with pseudo-infectious viral particles expressed various transgenes at high levels. Finally, inserts from persistently replicating replicon RNA were easily isolated and recombined back into entry plasmids for sequencing and subsequent analysis. Conclusion Replication-ready replicon expression plasmids make the use of alphavirus replicons fast and easy as compared to traditional replicon production methods. This system represents a significant step forward in the utility and ease of use of alphavirus replicons in the study of gene function.

  3. Semliki Forest Virus: a viral vector with multiple applications.

    Directory of Open Access Journals (Sweden)

    Luis Felipe Henao

    2009-11-01

    Full Text Available Se han utilizado los alfavirus como vectores de expresión, entre estos se encuentra el Semliki Forest virus (SFV, que es un virus envuelto, el cual, además de replicarse en el citoplasma, tiene la propiedad de expresar por separado las proteínas estructurales de las no estructurales, permitiendo un mayor control de la expresión. Los vectores derivados del SFV pueden tener una gama amplia de aplicaciones. Se pueden obtener altos títulos virales para la expresión eficiente de proteínas en diferentes líneas celulares. Pueden infectar un espectro amplio de células de mamíferos, así como de tejidos. Son prometedores para ser usados en la terapia génica como vehículos para el envío de genes específicos in vivo o in vitro, tanto en la terapia contra el cáncer como en la neuronal, especialmente cuando sólo sea necesaria una expresión a corto plazo. Sus aplicaciones en la producción de vacunas profilácticas o terapéuticas, es otro aspecto estudiado; se ha demostrado la generación de respuestas inmunes importantes contra diferentes enfermedades virales y tumorales. El desarrollo de nuevos vectores no citopáticos, de otros regulados por temperatura, así como también de otros con replicación persistente; permitirán la prolongación de la expresión. Debido a estas nuevas ventajas y a las ya conocidas, gradualmente se podrían ampliar los usos para los vectores derivados del SFV a medida que se controlen sus efectos no deseados.

  4. Coordinated function of cellular DEAD-box helicases in suppression of viral RNA recombination and maintenance of viral genome integrity.

    Directory of Open Access Journals (Sweden)

    Chingkai Chuang

    2015-02-01

    Full Text Available The intricate interactions between viruses and hosts include an evolutionary arms race and adaptation that is facilitated by the ability of RNA viruses to evolve rapidly due to high frequency mutations and genetic RNA recombination. In this paper, we show evidence that the co-opted cellular DDX3-like Ded1 DEAD-box helicase suppresses tombusviral RNA recombination in yeast model host, and the orthologous RH20 helicase functions in a similar way in plants. In vitro replication and recombination assays confirm the direct role of the ATPase function of Ded1p in suppression of viral recombination. We also present data supporting a role for Ded1 in facilitating the switch from minus- to plus-strand synthesis. Interestingly, another co-opted cellular helicase, the eIF4AIII-like AtRH2, enhances TBSV recombination in the absence of Ded1/RH20, suggesting that the coordinated actions of these helicases control viral RNA recombination events. Altogether, these helicases are the first co-opted cellular factors in the viral replicase complex that directly affect viral RNA recombination. Ded1 helicase seems to be a key factor maintaining viral genome integrity by promoting the replication of viral RNAs with correct termini, but inhibiting the replication of defective RNAs lacking correct 5' end sequences. Altogether, a co-opted cellular DEAD-box helicase facilitates the maintenance of full-length viral genome and suppresses viral recombination, thus limiting the appearance of defective viral RNAs during replication.

  5. Development of Viral Vectors for Gene Therapy for Chronic Pain

    Directory of Open Access Journals (Sweden)

    Yu Huang

    2011-01-01

    Full Text Available Chronic pain is a major health concern that affects millions of people. There are no adequate long-term therapies for chronic pain sufferers, leading to significant cost for both society and the individual. The most commonly used therapy for chronic pain is the application of opioid analgesics and nonsteroidal anti-inflammatory drugs, but these drugs can lead to addiction and may cause side effects. Further studies of the mechanisms of chronic pain have opened the way for development of new treatment strategies, one of which is gene therapy. The key to gene therapy is selecting safe and highly efficient gene delivery systems that can deliver therapeutic genes to overexpress or suppress relevant targets in specific cell types. Here we review several promising viral vectors that could be applied in gene transfer for the treatment of chronic pain and further discuss the possible mechanisms of genes of interest that could be delivered with viral vectors for the treatment of chronic pain.

  6. Neuropeptide Y Y1 receptor hippocampal overexpression via viral vectors is associated with modest anxiolytic-like and proconvulsant effects in mice

    DEFF Research Database (Denmark)

    Olesen, Mikkel V; Christiansen, Søren Hofman Oliveira; Gøtzsche, Casper René

    2012-01-01

    Abstract Neuropeptide Y (NPY) exerts anxiolytic- and antidepressant-like effects in rodents that appear to be mediated via Y1 receptors. Gene therapy using recombinant viral vectors to induce overexpression of NPY in the hippocampus or amygdala has previously been shown to confer anxiolytic......-like effect in rodents. The present study explored an alternative and more specific approach: overexpression of Y1 receptors. Using a recombinant adeno-associated viral vector (rAAV) encoding the Y1 gene (rAAV-Y1), we, for the first time, induced overexpression of functional transgene Y1 receptors...

  7. Construction of human artificial chromosome vectors by recombineering.

    Science.gov (United States)

    Kotzamanis, George; Cheung, Wing; Abdulrazzak, Hassan; Perez-Luz, Sara; Howe, Steven; Cooke, Howard; Huxley, Clare

    2005-05-23

    Human artificial chromosomes (HACs) can be formed de novo by transfection of large fragments of cloned alphoid DNA into human HT1080 cells in tissue culture. In order to generate HACs carrying a gene of interest, one can either co-transfect the alphoid DNA and the gene of interest, or one can clone both into a single vector prior to transfection. Here we describe linking approximately 70 kb of alphoid DNA onto a 156-kb BAC carrying the human HPRT gene using Red homologous recombination in the EL350 Escherichia coli host [Lee et al., Genomics 73 (2001) 56-65]. A selectable marker and EGFP marker were then added by loxP/Cre recombination using the arabinose inducible cre gene in the EL350 bacteria. The final construct generates minichromosomes in HT1080 cells and the HPRT gene is expressed. The retrofitting vector can be used to add the approximately 70 kb of alphoid DNA to any BAC carrying a gene of interest to generate a HAC vector. The method can also be used to link any unrelated BAC or PAC insert onto another BAC clone. The EL350 bacteria are an excellent host for building up complex vectors by a combination of homologous and loxP/Cre recombination.

  8. Evolving lessons on nanomaterial-coated viral vectors for local and systemic gene therapy.

    Science.gov (United States)

    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.

  9. Chikungunya Virus Vaccines: Viral Vector-Based Approaches.

    Science.gov (United States)

    Ramsauer, Katrin; Tangy, Frédéric

    2016-12-15

    In 2013, a major chikungunya virus (CHIKV) epidemic reached the Americas. In the past 2 years, >1.7 million people have been infected. In light of the current epidemic, with millions of people in North and South America at risk, efforts to rapidly develop effective vaccines have increased. Here, we focus on CHIKV vaccines that use viral-vector technologies. This group of vaccine candidates shares an ability to potently induce humoral and cellular immune responses by use of highly attenuated and safe vaccine backbones. So far, well-described vectors such as modified vaccinia virus Ankara, complex adenovirus, vesicular stomatitis virus, alphavirus-based chimeras, and measles vaccine Schwarz strain (MV/Schw) have been described as potential vaccines. We summarize here the recent data on these experimental vaccines, with a focus on the preclinical and clinical activities on the MV/Schw-based candidate, which is the first CHIKV-vectored vaccine that has completed a clinical trial. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  10. Characterization of recombinant Raccoonpox Vaccine Vectors in Chickens

    Science.gov (United States)

    Hwa, S.-H.; Iams, K.P.; Hall, J.S.; Kingstad, B.A.; Osorio, J.E.

    2010-01-01

    Raccoonpox virus (RCN) has been used as a recombinant vector against several mammalian pathogens but has not been tested in birds. The replication of RCN in chick embryo fibroblasts (CEFs) and chickens was studied with the use of highly pathogenic avian influenza virus H5N1 hemagglutinin (HA) as a model antigen and luciferase (luc) as a reporter gene. Although RCN replicated to low levels in CEFs, it efficiently expressed recombinant proteins and, in vivo, elicited anti-HA immunoglobulin yolk (IgY) antibody responses comparable to inactivated influenza virus. Biophotonic in vivo imaging of 1-wk-old chicks with RCN-luc showed strong expression of the luc reporter gene lasting up to 3 days postinfection. These studies demonstrate the potential of RCN as a vaccine vector for avian influenza and other poultry pathogens. ?? American Association of Avian Pathologists 2010.

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

    Science.gov (United States)

    High, Katherine A.; Anguela, Xavier M.

    2016-01-01

    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

  12. Generation and characterization of NV gene-knockout recombinant viral hemorrhagic septicemia virus (VHSV) genotype IVa.

    Science.gov (United States)

    Kim, Min Sun; Kim, Dong Soo; Kim, Ki Hong

    2011-11-03

    A recombinant viral hemorrhagic septicemia virus (rVHSV-deltaNV-EGFP) containing the enhanced green fluorescent protein (EGFP) gene instead of the NV gene was produced using the reverse-genetics method. For use as a positive control, another recombinant virus (rVHSV-wild) was also generated, which had an identical nucleotide sequence to the wild-type VHSV genome except for a few artificially replaced nucleotides. The rVHSVs were rescued using a system controlled by T7 RNA polymerase supplied by a retroviral vector. Generation of rVHSV-deltaNV-EGFP and rVHSV-wild was confirmed by sequencing of RT-PCR products, and rescue of infectious rVHSVs was confirmed by observation of plaque formation. Replication efficiency of rVHSV-wild was distinctly lower than that of wild-type VHSV, suggesting that the artificially replaced nucleotides, especially when immediately preceding the G or NV gene start codons, might affect the replication of the virus. Replication of rVHSV-deltaNV-EGFP was slightly lower than that of rVHSV-wild when epithelioma papulosum cyprini cells were infected with multiplicity of infection (MOI) 1.0, but much lower when cells were infected with MOI 0.00001. These results suggest that the NV gene plays an important role in VHSV replication through interactions with host-cell responses, and the lower replication ability of rVHSV-wild compared to wild-type VHSV might be caused by replaced nucleotides just before the NV gene open reading frame (ORF) rather than the G gene ORF. In olive flounder Paralichthys olivaceus, rVHSV-wild produced slower-progressing mortalities than wild-type VHSV, whereas rVHSV-deltaNV-EGFP pathogenesis was highly attenuated. These results suggest that the NV protein of VHSV may play an important role not only in viral replication but also in viral pathogenesis.

  13. Combination recombinant simian or chimpanzee adenoviral vectors for vaccine development.

    Science.gov (United States)

    Cheng, Cheng; Wang, Lingshu; Ko, Sung-Youl; Kong, Wing-Pui; Schmidt, Stephen D; Gall, Jason G D; Colloca, Stefano; Seder, Robert A; Mascola, John R; Nabel, Gary J

    2015-12-16

    Recombinant adenoviral vector (rAd)-based vaccines are currently being developed for several infectious diseases and cancer therapy, but pre-existing seroprevalence to such vectors may prevent their use in broad human populations. In this study, we investigated the potential of low seroprevalence non-human primate rAd vectors to stimulate cellular and humoral responses using HIV/SIV Env glycoprotein (gp) as the representative antigen. Mice were immunized with novel simian or chimpanzee rAd (rSAV or rChAd) vectors encoding HIV gp or SIV gp by single immunization or in heterologous prime/boost combinations (DNA/rAd; rAd/rAd; rAd/NYVAC or rAd/rLCM), and adaptive immunity was assessed. Among the rSAV and rChAd tested, rSAV16 or rChAd3 vector alone generated the most potent immune responses. The DNA/rSAV regimen also generated immune responses similar to the DNA/rAd5 regimen. rChAd63/rChAd3 and rChAd3 /NYVAC induced similar or even higher levels of CD4+ and CD8+ T-cell and IgG responses as compared to rAd28/rAd5, one of the most potent combinations of human rAds. The optimized vaccine regimen stimulated improved cellular immune responses and neutralizing antibodies against HIV compared to the DNA/rAd5 regimen. Based on these results, this type of novel rAd vector and its prime/boost combination regimens represent promising candidates for vaccine development.

  14. Viral Hybrid Vectors for Somatic Integration - Are They the Better Solution?

    Directory of Open Access Journals (Sweden)

    Anja Ehrhardt

    2009-12-01

    Full Text Available The turbulent history of clinical trials in viral gene therapy has taught us important lessons about vector design and safety issues. Much effort was spent on analyzing genotoxicity after somatic integration of therapeutic DNA into the host genome. Based on these findings major improvements in vector design including the development of viral hybrid vectors for somatic integration have been achieved. This review provides a state-of-the-art overview of available hybrid vectors utilizing viruses for high transduction efficiencies in concert with various integration machineries for random and targeted integration patterns. It discusses advantages but also limitations of each vector system.

  15. [Innate immune mechanisms against recombinant adeno-associated virus vectors--a review].

    Science.gov (United States)

    Diao, Yong; Xu, Ruian

    2012-05-04

    Recombinant adeno-associated virus (rAAV) is one of the most commonly used vectors for gene therapy. Despite the promising safety profile demonstrated in preclinical trials, the clinic efficacy of using rAAV was hampered by undesired response from the immune system. It is important to understand the mechanisms that lead to the induction of immune response against rAAV. Although a crucial role for innate immunity is shaping adaptive immune responses, the innate immune to rAAV was ignored in the past. Till now, at least three human cell types (dendritic cells, macrophages and endothelial cells) were discovered to be involved in sensing rAAV infection. The engagement of TLR9 by rAAV vector genomes triggers the activation of NF-kappaB signaling cascades, leading to the induction of pro-inflammatory cytokine genes. The viral capsid components are detected by TLR2, and this leads to the production of type I interferon mediated by interferon regulatory factors (IRFs) pathway. Self-complementary rAAV vectors induced higher TLR9 dependent innate immune response than single stranded rAAV. This review highlights the recent findings regarding the innate immune responses to rAAV vectors, the signaling pathways involved, and the impacts of innate immunity on the adaptive immune response to rAAV and its transgene expression.

  16. Gene transfer to the nonhuman primate retina with recombinant feline immunodeficiency virus vectors.

    Science.gov (United States)

    Lotery, Andrew J; Derksen, Todd A; Russell, Stephen R; Mullins, Robert F; Sauter, Sybille; Affatigato, Louisa M; Stone, Edwin M; Davidson, Beverly L

    2002-04-10

    We hypothesize that recombinant feline immunodeficiency viral (rFIV) vectors may be useful for gene transfer to the nonhuman primate retina. We performed vitrectomies and subretinal injections in the right eyes of 11 cynomolgus monkeys. Vesicular stomatitis virus glycoprotein-pseudotyped rFIV that expressed the Escherichia coli beta-galactosidase gene was injected into eight eyes. Sham vehicle or lactose buffer injections were also performed in two of these eight study eyes. rFIV pseudotyped with an amphotropic envelope was used in two eyes, and in one animal injections of lactose buffer only were given. After surgery the animals were clinically evaluated by retinal photography and electroretinography. beta-Galactosidase expression was evaluated, at a final end point, in histological sections. We found photoreceptor and Müller cells to have the greatest transgene expression. Focal inflammatory responses localized to the injection site were seen histologically in all eyes. No difference in transduction efficiency was seen between injections near the macula and more peripheral injections. Visual function as assessed by electroretinography was not significantly affected by vector or vehicle injections. We conclude that rFIV vectors administered beneath the retina can transduce a variety of retinal cells in the nonhuman primate retina. rFIV vectors have therapeutic potential and could be exploited to develop gene therapy for the human eye.

  17. Use of recombinant adenovirus vectored consensus IFN-α to avert severe arenavirus infection.

    Directory of Open Access Journals (Sweden)

    Brian B Gowen

    Full Text Available Several arenaviruses can cause viral hemorrhagic fever, a severe disease with case-fatality rates in hospitalized individuals ranging from 15-30%. Because of limited prophylaxis and treatment options, new medical countermeasures are needed for these viruses classified by the National Institutes of Allergy and Infectious Diseases (NIAID as top priority biodefense Category A pathogens. Recombinant consensus interferon alpha (cIFN-α is a licensed protein with broad clinical appeal. However, while cIFN-α has great therapeutic value, its utility for biodefense applications is hindered by its short in vivo half-life, mode and frequency of administration, and costly production. To address these limitations, we describe the use of DEF201, a replication-deficient adenovirus vector that drives the expression of cIFN-α, for pre- and post-exposure prophylaxis of acute arenaviral infection modeled in hamsters. Intranasal administration of DEF201 24 h prior to challenge with Pichindé virus (PICV was highly effective at protecting animals from mortality and preventing viral replication and liver-associated disease. A significant protective effect was still observed with a single dosing of DEF201 given two weeks prior to PICV challenge. DEF201 was also efficacious when administered as a treatment 24 to 48 h post-virus exposure. The protective effect of DEF201 was largely attributed to the expression of cIFN-α, as dosing with a control empty vector adenovirus did not protect hamsters from lethal PICV challenge. Effective countermeasures that are highly stable, easily administered, and elicit long lasting protective immunity are much needed for arena and other viral infections. The DEF201 technology has the potential to address all of these issues and may serve as a broad-spectrum antiviral to enhance host defense against a number of viral pathogens.

  18. Single vector system for efficient N-myristoylation of recombinant proteins in E. coli.

    Directory of Open Access Journals (Sweden)

    Julian M Glück

    Full Text Available BACKGROUND: N-myristoylation is a crucial covalent modification of numerous eukaryotic and viral proteins that is catalyzed by N-myristoyltransferase (NMT. Prokaryotes are lacking endogenous NMT activity. Recombinant production of N-myristoylated proteins in E. coli cells can be achieved by coexpression of heterologous NMT with the target protein. In the past, dual plasmid systems were used for this purpose. METHODOLOGY/PRINCIPAL FINDINGS: Here we describe a single vector system for efficient coexpression of substrate and enzyme suitable for production of co- or posttranslationally modified proteins. The approach was validated using the HIV-1 Nef protein as an example. A simple and efficient protocol for production of highly pure and completely N-myristoylated Nef is presented. The yield is about 20 mg myristoylated Nef per liter growth medium. CONCLUSIONS/SIGNIFICANCE: The single vector strategy allows diverse modifications of target proteins recombinantly coexpressed in E. coli with heterologous enzymes. The method is generally applicable and provides large amounts of quantitatively processed target protein that are sufficient for comprehensive biophysical and structural studies.

  19. Generation of Cell Lines to Complement Adenovirus Vectors using Recombination-Mediated Cassette Exchange

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    Farley Daniel C

    2010-12-01

    Full Text Available Abstract Background Adenovirus serotype 5 (Ad5 has many favourable characteristics for development as a gene therapy vector. However, the utility of current Ad5 vectors is limited by transient transgene expression, toxicity and immunogenicity. The most promising form of vector is the high capacity type, which is deleted for all viral genes. However, these vectors can only be produced to relatively low titres and with the aid of helper virus. Therefore a continuing challenge is the generation of more effective Ad5 vectors that can still be grown to high titres. Our approach is to generate complementing cell lines to support the growth of Ad5 vectors with novel late gene deficiencies. Results We have used LoxP/Cre recombination mediated cassette exchange (RMCE to generate cell lines expressing Ad5 proteins encoded by the L4 region of the genome, the products of which play a pivotal role in the expression of Ad5 structural proteins. A panel of LoxP parent 293 cell lines was generated, each containing a GFP expression cassette under the control of a tetracycline-regulated promoter inserted at a random genome location; the cassette also contained a LoxP site between the promoter and GFP sequence. Clones displayed a variety of patterns of regulation, stability and level of GFP expression. Clone A1 was identified as a suitable parent for creation of inducible cell lines because of the tight inducibility and stability of its GFP expression. Using LoxP-targeted, Cre recombinase-mediated insertion of an L4 cassette to displace GFP from the regulated promoter in this parent clone, cell line A1-L4 was generated. This cell line expressed L4 100K, 22K and 33K proteins at levels sufficient to complement L4-33K mutant and L4-deleted viruses. Conclusions RMCE provides a method for rapid generation of Ad5 complementing cell lines from a pre-selected parental cell line, chosen for its desirable transgene expression characteristics. Parent cell lines can be

  20. Viral replication is enhanced by an HIV-1 intersubtype recombination-derived Vpu protein

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    Salomón Horacio

    2010-10-01

    Full Text Available Abstract Background Multiple HIV-1 intersubtype recombinants have been identified in human populations. Previous studies from our lab group have shown that the epidemic in Argentina is characterized by the high prevalence of a circulating recombinant form, CRF12_BF, and many related BF recombinant forms. In these genomic structures a recombination breakpoint frequently involved the vpu coding region. Due to the scarce knowledge of Vpu participation in the virion release process and its impact on pathogenesis and of the functional capacities of intersubtype recombinant Vpu proteins, the aim of this work was to perform a comparative analysis on virion release capacity and relative replication capacity among viral variants harboring either a BF recombinant Vpu or a subtype B Vpu. Results Our results showed that BF recombinant Vpu was associated to an increased viral particles production when compared to WT B variant in tetherin-expressing cell lines. This observation was tested in the context of a competition assay between the above mentioned variants. The results showed that the replication of the BF Vpu-harboring variant was more efficient in cell cultures than subtype B, reaching a higher frequency in the viral population in a short period of time. Conclusion This study showed that as a result of intersubtype recombination, a structurally re-organized HIV-1 Vpu has an improved in vitro capacity of enhancing viral replication, and provides evidence of the changes occurring in this protein function that could play an important role in the successful spread of intersubtype recombinant variants.

  1. STUDY OF MUTAGENICITY OF VIRAL VECTOR IN TUMOR GENETHERAPY

    Institute of Scientific and Technical Information of China (English)

    李贺书; 李殿俊; 刘旭; 李大林

    2002-01-01

    Objective: To observe the mutagenicity of retrovirus and adenovirus as transgenic vectors to evaluate the safety of transgenic tumor cells as tumor vaccines. Methods: Cells were cultured together with the virus. Then DNA and supernatant were tested for mutagenicity by means of genetic toxicological laboratory technique. Results: The results indicated that DNA and supernatant of transgenic cells had no mutagenicity through both in vivo and in vitro tests. Conclusion: The modified virus had no mutagenicity as a transgenic vector.

  2. Ultrasound enhances the transfection of plasmid DNA by non-viral vectors.

    Science.gov (United States)

    Hosseinkhani, Hossein; Aoyama, Teruyoshi; Ogawa, Osamu; Tabata, Yasuhiko

    2003-04-01

    Increasing attention has been paid to technology used for the delivery of genetic materials into cells for gene therapy and the generation of genetically engineered cells. So far, viral vectors have been mainly used because of their inherently high transfection efficiency of gene. However, there are some problems to be resolved for the clinical applications, such as the pathogenicity and immunogenicity of viral vectors themselves. Therefore, many research trials with non-viral vectors have been performed to enhance their efficiency to a level comparable to the viral vector. Two directions of these trials exist: material improvement of non-viral vectors and their combination with various external physical stimuli. This paper reviews the latter research trials, with special attention paid to the enhancement of gene expression by ultrasound (US). The expression level of plasmid DNA by various cationized polymers and liposomes is promoted by US irradiation in vitro as well as in vivo. This US-enhanced expression of plasmid DNA will be discussed to emphasize the technical feasibility of US in gene therapy and biotechnology.

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

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    Kaoru Hida

    Full Text Available 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.

  4. Vaccines for viral and parasitic diseases produced with baculovirus vectors

    NARCIS (Netherlands)

    Oers, van M.M.

    2006-01-01

    The baculovirus¿insect cell expression system is an approved system for the production of viral antigens with vaccine potential for humans and animals and has been used for production of subunit vaccines against parasitic diseases as well. Many candidate subunit vaccines have been expressed in this

  5. Preclinical assessment of viral vectored and protein vaccines targeting the Duffy-binding protein region II of Plasmodium vivax

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    Simone C de Cassan

    2015-07-01

    Full Text Available Malaria vaccine development has largely focused on Plasmodium falciparum; however a reawakening to the importance of P. vivax has spurred efforts to develop vaccines against this difficult to treat and at times severe form of relapsing malaria, which constitutes a significant proportion of human malaria cases worldwide. The almost complete dependence of P. vivax red blood cell invasion on the interaction of the P. vivax Duffy-binding protein region II (PvDBP_RII with the human Duffy antigen receptor for chemokines (DARC, makes this antigen an attractive vaccine candidate against blood-stage P. vivax. Here, we generated both preclinical and clinically-compatible adenoviral and poxviral vectored vaccine candidates expressing the Salvador I allele of PvDBP_RII – including human adenovirus serotype 5 (HAdV5, chimpanzee adenovirus serotype 63 (ChAd63 and modified vaccinia virus Ankara (MVA vectors. We report on the antibody and T cell immunogenicity of these vaccines in mice or rabbits, either used alone in a viral vectored prime-boost regime, or in ‘mixed-modality’ adenovirus prime – protein-in-adjuvant boost regimes (using a recombinant protein PvDBP_RII protein antigen formulated in Montanide®ISA720 or Abisco®100 adjuvants. Antibodies induced by these regimes were found to bind to native parasite antigen from P. vivax infected Thai patients and were capable of inhibiting the binding of PvDBP_RII to its receptor DARC using an in vitro binding inhibition assay. In recent years, recombinant ChAd63 and MVA vectors have been quickly translated into human clinical trials for numerous antigens from P. falciparum as well as a growing number of other pathogens. The vectors reported here are immunogenic in small animals, elicit antibodies against PvDBP_RII and have recently entered clinical trials which will provide the first assessment of the safety and immunogenicity of the PvDBP_RII antigen in humans.

  6. Generation of Recombinant Viral Hemorrhagic Septicemia Virus (rVHSV) Expressing Two Foreign Proteins and Effect of Lengthened Viral Genome on Viral Growth and In Vivo Virulence.

    Science.gov (United States)

    Kim, Min Sun; Lee, Su Jin; Kim, Dong Soo; Kim, Ki Hong

    2016-04-01

    In this study, a new recombinant VHSV (rVHSV-Arfp-Bgfp) was generated by insertion of a red fluorescent protein (RFP) gene between N and P genes, a green fluorescent protein (GFP) gene between P and M genes of VHSV genome, the expression of each heterologous gene in infected cells, and effects of the lengthened recombinant VHSV's genome on the replication ability and in vivo virulence to olive flounder (Paralichthys olivaceus) fingerlings were compared with previously generated rVHSVs (rVHSV-wild, rVHSV-Arfp, and rVHSV-Brfp). The expression of RFP and GFP in cells infected with rVHSV-Arfp-Bgfp was verified through fluorescent microscopy and FACS analysis. In the viral growth analysis, rVHSV-Arfp and rVHSV-Brfp showed significantly lower viral titers than rVHSV-wild, and the replication of rVHSV-Arfp-Bgfp was significantly decreased compared to that of even rVHSV-Arfp or rVHSV-Brfp. These results suggest that the genome length is a critical factor for the determination of rVHSVs replication efficiency. In the in vivo virulence experiment, the cumulative mortalities of olive flounder fingerlings infected with each rVHSV were inversely proportional to the length of the viral genome, suggesting that decreased viral growth rate due to the lengthened viral genome is accompanied with the decrease of in vivo virulence of rVHSVs. Recombinant viruses expressing multiple foreign antigens can be used for the development of combined vaccines. However, as the present rVHSV-Arfp-Bgfp still possesses an ability to kill hosts (although very weakened), researches on the producing more attenuated viruses or propagation-deficient replicon particles are needed to solve safety-related problems.

  7. Retroviral vectors for homologous recombination provide efficient cloning and expression in mammalian cells.

    Science.gov (United States)

    Kobayashi, Eiji; Kishi, Hiroyuki; Ozawa, Tatsuhiko; Horii, Masae; Hamana, Hiroshi; Nagai, Terumi; Muraguchi, Atsushi

    2014-02-14

    Homologous recombination technologies enable high-throughput cloning and the seamless insertion of any DNA fragment into expression vectors. Additionally, retroviral vectors offer a fast and efficient method for transducing and expressing genes in mammalian cells, including lymphocytes. However, homologous recombination cannot be used to insert DNA fragments into retroviral vectors; retroviral vectors contain two homologous regions, the 5'- and 3'-long terminal repeats, between which homologous recombination occurs preferentially. In this study, we have modified a retroviral vector to enable the cloning of DNA fragments through homologous recombination. To this end, we inserted a bacterial selection marker in a region adjacent to the gene insertion site. We used the modified retroviral vector and homologous recombination to clone T-cell receptors (TCRs) from single Epstein Barr virus-specific human T cells in a high-throughput and comprehensive manner and to efficiently evaluate their function by transducing the TCRs into a murine T-cell line through retroviral infection. In conclusion, the modified retroviral vectors, in combination with the homologous recombination method, are powerful tools for the high-throughput cloning of cDNAs and their efficient functional analysis. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Recombination and population mosaic of a multifunctional viral gene, adeno-associated virus cap.

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    Yasuhiro Takeuchi

    Full Text Available Homologous recombination is a dominant force in evolution and results in genetic mosaics. To detect evidence of recombination events and assess the biological significance of genetic mosaics, genome sequences for various viral populations of reasonably large size are now available in the GenBank. We studied a multi-functional viral gene, the adeno-associated virus (AAV cap gene, which codes for three capsid proteins, VP1, VP2 and VP3. VP1-3 share a common C-terminal domain corresponding to VP3, which forms the viral core structure, while the VP1 unique N-terminal part contains an enzymatic domain with phospholipase A2 activity. Our recombinant detection program (RecI revealed five novel recombination events, four of which have their cross-over points in the N-terminal, VP1 and VP2 unique region. Comparison of phylogenetic trees for different cap gene regions confirmed discordant phylogenies for the recombinant sequences. Furthermore, differences in the phylogenetic tree structures for the VP1 unique (VP1u region and the rest of cap highlighted the mosaic nature of cap gene in the AAV population: two dominant forms of VP1u sequences were identified and these forms are linked to diverse sequences in the rest of cap gene. This observation together with the finding of frequent recombination in the VP1 and 2 unique regions suggests that this region is a recombination hot spot. Recombination events in this region preserve protein blocks of distinctive functions and contribute to convergence in VP1u and divergence of the rest of cap. Additionally the possible biological significance of two dominant VP1u forms is inferred.

  9. The Use of Viral Vectors in Gene Transfer Therapy

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    A. Dziaková

    2016-05-01

    Full Text Available Gene therapy is strategy based on using genes as pharmaceuticals. Gene therapy is a treatment that involves altering the genes inside body's cells to stop disease. Genes contain DNA- the code controlling body form and function. Genes that do not work properly can cause disease. Gene therapy replaces a faulty gene or adds a new gene in an attempt to cure disease or improve the ability of the body to fight disease. Gene therapy holds promise for treating a wide range of diseases, including cancer, cystic fibrosis, heart disease, diabetes, hemophilia and AIDS. Various types of genetic material are used in gene therapy; double-stranded DNA (dsDNA, single-stranded DNA (ssDNA, plasmid DNA and antisense oligodeoxynucleotides (ASON. The success of gene therapy depends on assuring the entrance of the therapeutic gene to targeted cells without any form of biodegradation. Commonly used vectors in gene therapy are: adenoviruses (400 clinical studies; 23.8%, retroviruses (344 clinical studies; 20.5%, unenveloped/plasmid DNA (304 clinical studies, 17.7%, adeno-associated viruses (75 clinical studies; 4.5% and others. In this paper, we have reviewed the major gene delivery vectors and recent improvements made in their design meant to overcome the issues that commonly arise with the use of gene therapy vectors.

  10. Incorporating double copies of a chromatin insulator into lentiviral vectors results in less viral integrants

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    Rosenqvist Nina

    2009-02-01

    Full Text Available Abstract Background Lentiviral vectors hold great promise as gene transfer vectors in gene therapeutic settings. However, problems related to the risk of insertional mutagenesis, transgene silencing and positional effects have stalled the use of such vectors in the clinic. Chromatin insulators are boundary elements that can prevent enhancer-promoter interactions, if placed between these elements, and protect transgene cassettes from silencing and positional effects. It has been suggested that insulators can improve the safety and performance of lentiviral vectors. Therefore insulators have been incorporated into lentiviral vectors in order to enhance their safety profile and improve transgene expression. Commonly such insulator vectors are produced at lower titers than control vectors thus limiting their potential use. Results In this study we cloned in tandem copies of the chicken β-globin insulator (cHS4 on both sides of the transgene cassette in order to enhance the insulating effect. Our insulator vectors were produced at significantly lower titers compared to control vectors, and we show that this reduction in titer is due to a block during the transduction process that appears after reverse transcription but before integration of the viral DNA. This non-integrated viral DNA could be detected by PCR and, importantly, prevented efficient transduction of target cells. Conclusion These results have importance for the future use of insulator sequences in lentiviral vectors and might limit the use of insulators in vectors for in vivo use. Therefore, a careful analysis of the optimal design must be performed before insulators are included into clinical lentiviral vectors.

  11. Tubular structure induced by a plant virus facilitates viral spread in its vector insect.

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    Qian Chen

    Full Text Available Rice dwarf virus (RDV replicates in and is transmitted by a leafhopper vector in a persistent-propagative manner. Previous cytopathologic and genetic data revealed that tubular structures, constructed by the nonstructural viral protein Pns10, contain viral particles and are directly involved in the intercellular spread of RDV among cultured leafhopper cells. Here, we demonstrated that RDV exploited these virus-containing tubules to move along actin-based microvilli of the epithelial cells and muscle fibers of visceral muscle tissues in the alimentary canal, facilitating the spread of virus in the body of its insect vector leafhoppers. In cultured leafhopper cells, the knockdown of Pns10 expression due to RNA interference (RNAi induced by synthesized dsRNA from Pns10 gene strongly inhibited tubule formation and prevented the spread of virus among insect vector cells. RNAi induced after ingestion of dsRNA from Pns10 gene strongly inhibited formation of tubules, preventing intercellular spread and transmission of the virus by the leafhopper. All these results, for the first time, show that a persistent-propagative virus exploits virus-containing tubules composed of a nonstructural viral protein to traffic along actin-based cellular protrusions, facilitating the intercellular spread of the virus in the vector insect. The RNAi strategy and the insect vector cell culture provide useful tools to investigate the molecular mechanisms enabling efficient transmission of persistent-propagative plant viruses by vector insects.

  12. Constructing recombinant replication-defective adenoviral vectors that express glucose transporter-1 through in vitro ligation

    Institute of Scientific and Technical Information of China (English)

    Fangcheng Li; Junliang Li; Ranyi Liu; Xinke Xu; Kaichang Yuan; Zhonghua Wu

    2008-01-01

    BACKGROUND: We constructed a homologous recombination bacterial method based on the pAdEasy system, a widely used system, for generating recombinant adenoviral vectors that express glucose transporter-1 (GLUT1) in rats.OBJECTIVE: This study was designed to investigate the feasibility of generating recombinant replication-defective adenoviral vectors that express GLUT1 in rats by in vitro ligation based on the Adeno-XTM system. DESIGN: An in vitro cell-based experiment. SETTING: This study was performed at the Linbaixin Medical Research Center of the Second Hospital Affiliated to Sun Yat-sen University and Central Laboratory for Prevention and Treatment of Tumor, Sun Yat-sen University between January and August 2004. MATERIALS: Male, adult, Sprague Dawley rats were used to extract total RNA from brain tissue. E. coli DH5?and human embryonic kidney 293 cells (HEK293 cells) used in the present study were cryo-preserved by the Second Hospital Affiliated to Sun Yat-sen University. Rabbit anti-rat GLUT1 polyclonal antibody (Chemicon, U.S.A.) and primers (Shanghai Boya Bioengineering Co., Ltd) were also used. METHODS: E1/E3-deleted replication-defective adenoviral vectors were used. Using in vitro ligation, the target gene was first sub-cloned into a shuttle vector plasmid to obtain the fragment containing target gene expression cassettes by enzyme digestion. Subsequently, the fragment was co-transformed with linearized adenoviral backbone vector into the E. coli strain. The recombinant adenoviral plasmid was transfected into HEK293 cells to assembly recombinant adenoviral vectors with replication capabilities. The procedure was repeated several times for recombinant adenoviral vectors amplification. MAIN OUTCOME MEASURES: Efficiency of recombinant adenoviral vectors to express the target gene was measured by gene and protein expression through polymerase chain reaction and Western Blot assays, respectively.RESULTS: Results demonstrated that recombinant adenoviral

  13. Evaluation of the immune response elicited by vaccination with viral vectors encoding FMDV capsid proteins and boosted with inactivated virus.

    Science.gov (United States)

    Romanutti, Carina; D'Antuono, Alejandra; Palacios, Carlos; Quattrocchi, Valeria; Zamorano, Patricia; La Torre, Jose; Mattion, Nora

    2013-08-30

    The aim of the present study was to assess the effect of introducing a priming step with replication-defective viral vectors encoding the capsid proteins of FMDV, followed by a boost with killed virus vaccines, using a suitable BALB/c mice model. Additionally, the immune response to other combined vector immunization regimens was studied. For this purpose, we analyzed different prime-boost immunizations with recombinant adenovirus (Ad), herpesvirus amplicons (Hs) and/or killed virus (KV) vaccines. The highest antibody titers were found in the group that received two doses of adjuvanted KV (Pviral vectors induced a shift of the cytokine balance toward a Th1 type immune response regardless of the delivery system used for boosting. The highest IgG1 titer was induced by two doses of adjuvanted KV (P=0.0002) and the highest IgG2a titer corresponded to the group primed with Ad and boosted with KV (P=0.01). Re-stimulation of all groups of mice with 0.5 μg of inactivated virus five months later resulted in a fast increase of antibody titers in all the groups tested. After virus stimulation, antibody titers in the groups that received KV alone or Ad prime-KV boost, were indistinguishable (P=0.800). Protection from challenge was similar (75%) in the groups of animals that received Ad prime-Hs boost or Ad prime-KV boost, or two doses of oil-adjuvanted KV. The data presented in this study suggest that sequential immunization with viral vectors-based vaccines combined with protein-based vaccines have the potential to enhance the quality of the immune response against FMDV. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Role of RNase MRP in viral RNA degradation and RNA recombination.

    Science.gov (United States)

    Jaag, Hannah M; Lu, Qiasheng; Schmitt, Mark E; Nagy, Peter D

    2011-01-01

    RNA degradation, together with RNA synthesis, controls the steady-state level of viral RNAs in infected cells. The endoribonucleolytic cleavage of viral RNA is important not only for viral RNA degradation but for RNA recombination as well, due to the participation of some RNA degradation products in the RNA recombination process. To identify host endoribonucleases involved in degradation of Tomato bushy stunt virus (TBSV) in a Saccharomyces cerevisiae model host, we tested eight known endoribonucleases. Here we report that downregulation of SNM1, encoding a component of the RNase MRP, and a temperature-sensitive mutation in the NME1 gene, coding for the RNA component of RNase MRP, lead to reduced production of the endoribonucleolytically cleaved TBSV RNA in yeast. We also show that the highly purified yeast RNase MRP cleaves the TBSV RNA in vitro, resulting in TBSV RNA degradation products similar in size to those observed in yeast cells. Knocking down the NME1 homolog in Nicotiana benthamiana also led to decreased production of the cleaved TBSV RNA, suggesting that in plants, RNase MRP is involved in TBSV RNA degradation. Altogether, this work suggests a role for the host endoribonuclease RNase MRP in viral RNA degradation and recombination.

  15. Viral vector vaccines expressing nucleoprotein and phosphoprotein genes of avian bornaviruses ameliorate homologous challenge infections in cockatiels and common canaries.

    Science.gov (United States)

    Olbert, Marita; Römer-Oberdörfer, Angela; Herden, Christiane; Malberg, Sara; Runge, Solveig; Staeheli, Peter; Rubbenstroth, Dennis

    2016-11-10

    Avian bornaviruses are causative agents of proventricular dilatation disease (PDD), an often fatal disease of parrots and related species (order Psittaciformes) which is widely distributed in captive psittacine populations and may affect endangered species. Here, we established a vaccination strategy employing two different well described viral vectors, namely recombinant Newcastle disease virus (NDV) and modified vaccinia virus Ankara (MVA) that were engineered to express the phosphoprotein and nucleoprotein genes of two avian bornaviruses, parrot bornavirus 4 (PaBV-4) and canary bornavirus 2 (CnBV-2). When combined in a heterologous prime/boost vaccination regime, NDV and MVA vaccine viruses established self-limiting infections and induced a bornavirus-specific humoral immune response in cockatiels (Nymphicus hollandicus) and common canaries (Serinus canaria forma domestica). After challenge infection with a homologous bornavirus, shedding of bornavirus RNA and viral loads in tissue samples were significantly reduced in immunized birds, indicating that vaccination markedly delayed the course of infection. However, cockatiels still developed signs of PDD if the vaccine failed to prevent viral persistence. Our work demonstrates that avian bornavirus infections can be repressed by vaccine-induced immunity. It represents a first crucial step towards a protective vaccination strategy to combat PDD in psittacine birds.

  16. Recombination of replicon and helper RNAs and the emergence of propagation-competent vectors upon Sindbis virus vector production.

    Science.gov (United States)

    Hyvärinen, Anna; Yongabi, Felicitas; Mäkinen, Kimmo; Wahlfors, Jarmo; Pellinen, Riikka

    2013-08-01

    Sindbis vectors have shown remarkable antitumor efficacy and tumor-targeting capacity in animal models and hold promise for cancer therapy. Different packaging systems are used to produce propagation-incompetent Sindbis vectors. However, the vectors produced using either DH-BB single helper RNA or split helper RNA can spread in permissive cell cultures. We investigated the mechanisms of vector spreading and show, here, that recombination occurs between the replicon and DH-BB helper RNA, leading to formation of the full-length virus genome. Split helper RNA may not completely prevent wild-type reversion, although the frequency is greatly reduced. Contrary to propagation of Sindbis DH-BB vectors, Sindbis split helper vectors were frequently able to spread without cytopathic effect (CPE), a feature that was linked to wild-type reversion. Our results support the hypothesis that the non-cytopathic local spreading constantly observed with Sindbis split helper vector results from unspecific packaging of helper RNAs into vector particles and co-infection with particles containing replicon and helper RNAs. Several malignant cell lines with defective interferon responses were found to be permissive for non-cytopathic spreading of the Sindbis split helper vector. Interferon-α suppressed the spreading providing a possible option to control the vector.

  17. An epidermal growth factor motif from Del1 protein increases the efficiency of in vivo gene transfer with a non-viral vector.

    Science.gov (United States)

    Mamiya, Atsushi; Kitano, Hisataka; Takao, Kyoichi; Kokubun, Shinichiro; Komiya, Masamichi; Hidai, Chiaki

    2013-06-01

    Increasing the efficiency of gene transfer using non-viral vectors, which have the potential to be safe and economical, would improve upon available options for gene therapy. We previously reported that the third EGF motif of the extracellular matrix protein Del1 (E3) increases the transfection efficiency of non-viral vector methods. Here, we asked if E3 could increase the in vivo transfection efficiency of a polyplex-based approach. To test this, cDNA encoding a heat-stable alkaline phosphatase (AP) was first injected intravenously into mice along with recombinant E3. After 24 h, exogenous AP activity in serum was measured. We found that the introduction of E3 resulted in 50 % more AP activity as compared to the control. We next tested transfection into a tumour explant of SCCKN cells, an oral carcinoma-derived cell line. To do this, a cDNA encoding yellow fluorescent protein was locally injected into a tumour explant, followed by local injection of recombinant E3. Use of E3 increased the number of transfected cells to 2.5 times that of the control. Histochemical staining revealed that E3-induced apoptosis in a tumour explant. The data suggest that E3 might be a useful tool for cancer gene therapy using non-viral vectors.

  18. Adeno-associated viral vector-induced overexpression of neuropeptide Y Y2 receptors in the hippocampus suppresses seizures

    DEFF Research Database (Denmark)

    Woldbye, David Paul Drucker; Ängehagen, Mikael; Gøtzsche, Casper René;

    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 predominantly mediated by Y2 receptors, which, together with neuropeptide Y, are upregulated after seizures as a compensatory mechanism. To explore whether such upregulation could prevent seizures, we overexpressed Y2 receptors in the hippocampus using...... and neuropeptide Y had a more pronounced seizure-suppressant effect. These results demonstrate that overexpression of Y2 receptors (alone or in combination with neuropeptide Y) could be an alternative strategy for epilepsy treatment....

  19. Potentiation of anthrax vaccines using protective antigen-expressing viral replicon vectors.

    Science.gov (United States)

    Wang, Hai-Chao; An, Huai-Jie; Yu, Yun-Zhou; Xu, Qing

    2015-02-01

    DNA vaccines require improvement for human use because they are generally weak stimulators of the immune system in humans. The efficacy of DNA vaccines can be improved using a viral replicon as vector to administer antigen of pathogen. In this study, we comprehensively evaluated the conventional non-viral DNA, viral replicon DNA or viral replicon particles (VRP) vaccines encoding different forms of anthrax protective antigen (PA) for specific immunity and protective potency against anthrax. Our current results clearly suggested that these viral replicon DNA or VRP vaccines derived from Semliki Forest virus (SFV) induced stronger PA-specific immune responses than the conventional non-viral DNA vaccines when encoding the same antigen forms, which resulted in potent protection against challenge with the Bacillus anthracis strain A16R. Additionally, the naked PA-expressing SFV replicon DNA or VRP vaccines without the need for high doses or demanding particular delivery regimens elicited robust immune responses and afforded completely protective potencies, which indicated the potential of the SFV replicon as vector of anthrax vaccines for use in clinical application. Therefore, our results suggest that these PA-expressing SFV replicon DNA or VRP vaccines may be suitable as candidate vaccines against anthrax. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Episomal maintenance of S/MAR-containing non-viral vectors for RPE-based diseases.

    Science.gov (United States)

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

    2014-01-01

    The efficacy of non-viral genetic therapies has historically been limited by transient gene expression and vector loss. Scaffold matrix attachment regions (S/MARs) have been shown to augment transcription, promote episomal maintenance, and provide insulator-like function to DNA in in vitro and in vivo systems. Here we explore the ability of S/MAR elements to mediate these effects in retinal pigment epithelial (RPE) cells with the eventual goal of improving the persistence of expression of our non-viral gene delivery tools. We engineered an RPE-specific reporter vector with or without an S/MAR immediately downstream of the eGFP expression cassette. We show that the S/MAR vector is maintained as an episome for up to 1 year. Experiments in which rhodamine-labeled DNA was delivered to the subretinal space of mice show better persistence of the S/MAR-containing vector in the RPE than the non-S/MAR vector. These results suggest that inclusion of the S/MAR region promotes episomal maintenance of plasmid DNA in the RPE after subretinal delivery and that inclusion of this DNA element may be beneficial for non-viral ocular gene transfer.

  1. Construction and expression of SET gene and siRNA recombinant adenovirus vectors

    Institute of Scientific and Technical Information of China (English)

    Xu Bo-qun; Lu Pin-hong; Li Ying; Xue Kai; Li Mei; Ma Xiang; Diao Fei-yan; Cui Yu-gui; Liu Jia-yin

    2010-01-01

    Objective: To construct SET gene recombinant adenovirus vector and SET gene small interfering RNA (SiRNA) recombinant adenovirus vector for over-expression or knock-down of SET levels.Methods: The cDNA sequence of SET was cloned by reverse transcriptive polymerase chain reaction (RT-PCR) and the SET gene fragment was subcloned into adenovirus shuttle plasmid pAdTrack-CMV to construct the shuttle plasmid pAdTrack-SET. The shuttle plasmid pAdtrack-SET was transformed into BJ5183 cells with the adenoviral backbone pAdEasy-1 to obtain the homologous recombinant Ad-CMV-SET and the recombinant Ad-CMV-SET was packaged and amplified in the AD293 cells. The expression of SET in AD293 cells was detected by Western blot. In addition, we constructed SET gene SiRNA recombinant adenovirus vector (Ad-H1-SiRNA/SET) and its efficacy of knockdown of SET protein was detected in infected GC-2spd(ts) cells by Western blot. Results: The recombinant adenovirus vectors, both SET gene recombinant adenovirus vector Ad-CMV-SET and SET gene SiRNA recombinant adenovirus vector Ad-H1-SiRNA/SET, were proven to be constructed successfully by the evidence of endonulease digestion and sequencing. AD293 cells infected with either recombinant adenovirus vector of Ad-CMV-SET or Ad-H1-SiRNA/SET were observed to express GFP. The expression of SET protein was up-regulated significantly in AD293 cells infected with SET gene recombinant adenovirus vector. On the contrast, SET protein was significantly down-regulated in the GC-2spd(ts) cells infected with Ad-H1-SiRNA/SET (P<0.05) and the knockdown efficiency was approximately 50%-70%. Conclusion: The recombinant adenovirus vector Ad-CMV-SET and Ad-H1-SiRNA/SET were successfully constructed and effectively expressed in germ cells and somatic cells. It provides an experimental tool for further study of SET gene in the physiological and pathophysiological mechanism of reproduction-related diseases.

  2. Extended minus-strand DNA as template for R-U5-mediated second-strand transfer in recombinational rescue of primer binding site-modified retroviral vectors

    DEFF Research Database (Denmark)

    Mikkelsen, J G; Lund, Anders Henrik; Dybkaer, K

    1998-01-01

    We have previously demonstrated recombinational rescue of primer binding site (PBS)-impaired Akv murine leukemia virus-based vectors involving initial priming on endogenous viral sequences and template switching during cDNA synthesis to obtain PBS complementarity in second-strand transfer...... of reverse transcription (Mikkelsen et al., J. Virol. 70:1439-1447, 1996). By use of the same forced recombination system, we have now found recombinant proviruses of different structures, suggesting that PBS knockout vectors may be rescued through initial priming on endogenous virus RNA, read......-through of the mutated PBS during minus-strand synthesis, and subsequent second-strand transfer mediated by the R-U5 complementarity of the plus strand and the extended minus-strand DNA acceptor template. Mechanisms for R-U5-mediated second-strand transfer and its possible role in retrovirus replication and evolution...

  3. A simplified purification protocol for recombinant adeno-associated virus vectors

    Directory of Open Access Journals (Sweden)

    Mark Potter

    2014-01-01

    Full Text Available We describe a new rapid, low cost, and scalable method for purification of various recombinant adeno-associated viruses (rAAVs from the lysates of producer cells of either mammalian or insect origin. The method takes advantage of two general biochemical properties of all characterized AAV serotypes: (i low isoelectric point of a capsid and (ii relative biological stability of the viral particle in the acidic environment. A simple and rapid clarification of cell lysate toremove the bulk of proteins and DNA is accomplished by utilizing inexpensive off-the-shelf reagents such as sodium citrate and citric acid. After the low-speed centrifugation step, the supernatant is subjected to cation exchange chromatography via sulfopropyl (SP column. The eluted virus may then be further concentrated by either centrifugal spin devices or tangential flow filtration yielding material of high titer and Good Manufacturing Practice (GMP grade biochemical purity. The protocol is validated for rAAV serotypes 2, 8, and 9. The described method makes rAAV vector technology readily available for the low budget research laboratories and could be easily adapted for a large scale GMP production format.

  4. Perinatal systemic gene delivery using adeno-associated viral vectors

    Directory of Open Access Journals (Sweden)

    Rajvinder eKarda

    2014-11-01

    Full Text Available Neurodegenerative monogenic diseases can also affect a broad range of tissues and organs throughout the body. An effective treatment would require a systemic approach. The intravenous administration of novel therapies is ideal but is hampered by the inability of such drugs to cross the blood-brain barrier and precludes efficacy in the central nervous system. A number of these early lethal intractable diseases also present devastating irreversible pathology at birth or soon after. Therefore, any therapy would ideally be administered during the perinatal period to prevent, stop or ameliorate disease progression. The concept of perinatal gene therapy has moved a step further towards being a feasible approach to treating such disorders. This has primarily been driven by the recent discoveries that particular serotypes of adeno-associated virus (AAV gene delivery vectors have the ability to cross the blood-brain barrier following intravenous administration. Furthermore, this has been safely demonstrated in perinatal mice and non-human primates. This review focuses on the progress made in using AAV to achieve systemic transduction and what this means for developing perinatal gene therapy for early lethal neurodegenerative diseases.

  5. A molecular toolbox for rapid generation of viral vectors to up- or down-regulate in vivo neuronal gene expression

    Directory of Open Access Journals (Sweden)

    Melanie D. White

    2011-07-01

    Full Text Available 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 miR. We show that AAV assembled to express HCN1 miR produces efficacious and specific in vivo knockdown of HCN1 channels. Comparison of in vivo viral transduction using HCN1 miR 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.

  6. Protection against myxomatosis and rabbit viral hemorrhagic disease with recombinant myxoma viruses expressing rabbit hemorrhagic disease virus capsid protein.

    OpenAIRE

    Bertagnoli, Stéphane; Gelfi, Jacqueline; Le Gall, Ghislaine; Boilletot, Eric; Vautherot, Jean-François; Rasschaert, Denis; Laurent, Sylvie; Petit, Frédérique; Boucraut-Baralon, Corine; Milon, Alain

    1996-01-01

    Two myxoma virus-rabbit hemorrhagic disease virus (RHDV) recombinant viruses were constructed with the SG33 strain of myxoma virus to protect rabbits against myxomatosis and rabbit viral hemorrhagic disease. These recombinant viruses expressed the RHDV capsid protein (VP60). The recombinant protein, which is 60 kDa in size, was antigenic, as revealed by its reaction in immunoprecipitation with antibodies raised against RHDV. Both recombinant viruses induced high levels of RHDV- and myxoma vir...

  7. [Construction and characterization of a novel recombinant retroviral vector expressing mouse T-bet].

    Science.gov (United States)

    Zhang, Xuejie; Zhang, Jianhua; Zhang, Wei; Guo, Jie; Zhou, Xuyu

    2014-10-01

    In order to study T-bet function in mouse cells, a novel retroviral vector expressing mouse T-bet and reporter gene Thy1.1 was constructed. Retrovirus particles were then produced by transfection of the recombinant retroviral plasmid into a packaging cell line Platinum-E. The recombinant retrovirus played considerable infection ability. T-bet expression was then identified by FACS after infection of CD4+ primary T cells from T-bet knockout mouse with recombinant retrovirus. To determine if exogenous expressing T-bet has normal function, we checked the expression level of T-bet target gene, Ifng. IFN-y expression was upregulated in the T-bet knockout T cells infected with recombinant retrovirus. In conclusion, we successfully constructed an effective mouse T-bet recombinant retroviral vector.

  8. Rapid high-yield expression of full-size IgG antibodies in plants coinfected with noncompeting viral vectors

    OpenAIRE

    Giritch, Anatoli; Marillonnet, Sylvestre; Engler, Carola; van Eldik, Gerben; Botterman, Johan; Klimyuk, Victor; Gleba, Yuri

    2006-01-01

    Plant viral vectors allow expression of heterologous proteins at high yields, but so far, they have been unable to express heterooligomeric proteins efficiently. We describe here a rapid and indefinitely scalable process for high-level expression of functional full-size mAbs of the IgG class in plants. The process relies on synchronous coinfection and coreplication of two viral vectors, each expressing a separate antibody chain. The two vectors are derived from two different plant viruses tha...

  9. Evaluation of a rapamycin-regulated serotype 2 adeno-associated viral vector in macaque parotid glands

    Science.gov (United States)

    Zheng, Changyu; Voutetakis, Antonis; Metzger, Mark; Wainer, Sandra; Cotrim, Ana P.; Eckhaus, Michael A.; Rivera, Victor M.; Clackson, Tim; Chiorini, John A.; Donahue, Robert E.; Dunbar, Cynthia E.; Baum, Bruce J.

    2009-01-01

    OBJECTIVES Salivary glands are useful target organs for local and systemic gene therapeutics. For such applications, the regulation of transgene expression is important. Previous studies by us in murine submandibular glands showed that a rapamycin transcriptional regulation system in a single serotype 2, adeno-associated viral (AAV2) vector was effective for this purpose. The present study evaluated if such a vector was similarly useful in rhesus macaque parotid glands. METHODS A recombinant AAV2 vector (AAV-TF-RhEpo-2.3w), encoding rhesus erythropoietin (RhEpo) and a rapamycin-inducible promoter, was constructed. The vector was administered to macaques at either of two doses (1.5×1011 [low dose] or 1.5×1012 [high dose] vector genomes) via cannulation of Stensen’s duct. Animals were followed for 12–14 weeks and treated at intervals with rapamycin (0.1 or 0.5 mg/kg) to induce gene expression. Serum chemistry, hematology and RhEpo levels were measured at interval. RESULTS AAV-TF-RhEpo-2.3w administration led to low levels of rapamycin-inducible RhEpo expression in the serum of most macaques. In five animals no significant changes were seen in serum chemistry and hematology values over the study. One macaque, however, developed pneumonia, became anemic and subsequently required euthanasia. After the onset of anemia, a single administration of rapamycin led to significant RhEpo production in this animal. CONCLUSION Administration of AAV-TF-RhEpo-2.3w to macaque parotid glands was generally safe, but led only to low levels of serum RhEpo in healthy animals following rapamycin treatment. PMID:20374510

  10. Effects of recombinant retroviral vector mediated human insulin like growth factor-1 gene transfection on skeletal muscle growth in rat

    Institute of Scientific and Technical Information of China (English)

    RONG Shu-Ling; LU Yong-Xin; LIAO Yu-Hua; WANG Xiao-Lin; GUO He-Ping; CHANG Chao; GAO Yan-Zhang; MI Shao-Hua; Wan Jian-Ping

    2006-01-01

    Background This study transferred a recombinant gene encoding human insulin like growth factor-1 (hIGF-1)into modified primary skeletal myoblasts with a retroviral vector (pLgXSN) and determined whether the hIGF-1 promoted growth of skeletal muscle in rat.Methods hIGF-lcDNA was amplified in vitro from normal human liver cells by using RT-PCR and cloned into plasmid vector pLgXSN. The recombinant vector pLghIGF-1SN and control vector pLgGFPSN were transfected into packaging cell PT67 and G418 was used to select positive colony. Myoblasts were infected with a high titre viral supernatant and transduction efficiency was evaluated as GFP expression. The expression of hIGF-1 mRNA in myoblasts was investigated by immunocytochemistry and RT-PCR. MTT assays detected the growth of myoblasts in vitro. Myoblasts transduced with pLghIGF-1SN were injected into hind limb muscles of 10-12 week male SD rats. Formed tissues were harvested 4 weeks later. Myocyte diameter, mean weight of hind limb and body were measured to evaluate the skeletal muscle growth.Results Recombinant retroviral plasmid vector pLghIGF-1SN was constructed successfully. The titre of the packaged recombinant retrovirus was 1 × 106 cfu/ml. The transfection rate of PT67 cells reached 100% after G418 screening. hIGF-1 expression was positive in myoblast-IGF-1. The proliferation rate of myoblast-IGF-1 in vitro was higher than GFP-myoblast or myoblast (P< 0.05). The mean weights of hind limb and body of rats injected myoblast-IGF-1 were higher than those of the rats injected with myoblast-GFP or myoblast (P< 0.05). Myocyte diameter had a significant increase in IGF-1 group compared to GFP group and myoblast group (P< 0.05).Conclusions The transfection of the human IGF- 1 gene mediated by a retroviral vector can promote the growth of skeletal muscle in rats. Genetically modified primary skeletal myoblasts provide a possibly effective approach to treat some skeletal muscle diseases.

  11. Production of Recombinant Vector Containing the Coding Sequence of Human Hepcidin

    Directory of Open Access Journals (Sweden)

    Keyhanvar, N.

    2013-01-01

    Full Text Available Background and objective: Hepcidin is a cystein-rich antimicrobial peptide,which is secreted by the liver. It fights against wide spectrum of bacteria, virusesand fungi and it is a major regulator of iron homeostasis. Today, scientists havemade many efforts on the production of hepcidin. Baculovirus expression systemis one of the best eukaryotic expression systems for production of recombinanthepcidin and production of the recombinant vector is one of the most importantsteps in this expression system.Material & Methods: First, the total RNA was separated from HepG2 cell lineas a source of hepcidin expression. Then, after synthesis of total cDNA, humanhepcidin sequence was amplified, using specific primers by PCR method. Next,hepcidin sequence was cloned into pTZ57R/T vector. After digestion ofrecombinant vector using ECoRI and BamHI restriction enzymes, recombinantpFastBac HT B vector containing human hepcidin cDNA was produced.Results: Coding sequence of human hepcidin is correctly cloned into pTZ57R/Tvector and sub cloning into pFastBac HT B vector is performed successfully. Thepresence of a clear band near 274 bp resulted from PCR amplification andrestriction enzyme are the confirmation of the cloning of human hepcidin.Conclusion: According to our knowledge, the present study is the first work thatfocuses on recombinant vector containing coding sequence of human prohepcidin.This recombinant vector can be used for human hepcidin production.Keywords: Vector; Hepcidin; Iron

  12. New Viral Vector for Superproduction of Epitopes of Vaccine Proteins in Plants

    Science.gov (United States)

    Tyulkina, L.G.; Skurat, E.V.; Frolova, O.Yu.; Komarova, T.V.; Karger, E.M.; Atabekov, I.G.

    2011-01-01

    The novel viral vectors PVX-CP AltMV and PVXdt-CP AltMV are superexpressors of the capsid protein (CP). These viral vectors were constructed on the basis of the potato virus X (PVX) genome andAlternantheramosaic virus (AltMV) CP gene. The expression, based on the hybrid viral vectors, is genetically safe, since the systemic transport and formation of infective viral particles are blocked. CP AltMV can self-assemble into virus-like particles (VLPs) in the absence of genomic RNA. The vectors can be used for the presentation of foreign peptides (including epitopes of human pathogens) on the surface of the VLP. The N-terminal extracellular domain (M2e) of the influenza virus A M2 protein and its truncated variant (ΔM2e) were used as model heterologous peptides for the construction of the chimeric CP AltMV. Chimeric CP AltMV retains its ability to self-assemble into VLP. The epitopes of the M2 influenza virus protein were not eliminated during the process of accumulation, polymerization and purification of chimeric VLP AltMV, providing evidence of the stability of chimeric VLP with C-terminal heterologous epitopes. It appears that VLP produced by the vectors PVX-CP AltMV and PVXdt-CP AltMV can be used in the field of biotechnology for the presentation of the epitopes of vaccine proteins on their surfaces. The chimeric VLP AltMV with the presented foreign epitopes can be used as candidate vaccines. PMID:22649706

  13. Viral vector-based reversible neuronal inactivation and behavioral manipulation in the macaque monkey

    Directory of Open Access Journals (Sweden)

    Kristina Juliane Nielsen

    2012-06-01

    Full Text Available Viral vectors are promising tools for the dissection of neural circuits. In principle, they can manipulate neurons at a level of specificity not otherwise achievable. While many studies have used viral vector-based approaches in the rodent brain, only a few have employed this technique in the non-human primate, despite the importance of this animal model for neuroscience research. Here, we report for the first time that a viral vector-based approach can be used to manipulate a monkey’s behavior in a task. For this purpose, we used the allatostatin receptor/allatostatin (AlstR/AL system, which has previously been shown to allow inactivation of neurons in vivo. The AlstR was expressed in neurons in monkey V1 by injection of an AAV1 vector. Two monkeys were trained in a detection task, in which they had to make a saccade to a faint peripheral target. Injection of AL caused a retinotopic deficit in the detection task in one monkey. Specifically, the monkey showed marked impairment for detection targets placed at the visual field location represented at the virus injection site, but not for targets shown elsewhere. We confirmed that these deficits indeed were due to the interaction of AlstR and AL by injecting saline, or AL at a V1 location without AlstR expression. Post-mortem histology confirmed AlstR expression in this monkey. We failed to replicate the behavioral results in a second monkey, as AL injection did not impair the second monkey’s performance in the detection task. However, post-mortem histology revealed a very low level of AlstR expression in this monkey. Our results demonstrate that viral vector-based approaches can produce effects strong enough to influence a monkey’s performance in a behavioral task, supporting the further development of this approach for studying how neuronal circuits control complex behaviors in non-human primates.

  14. Development of recombinant antigen array for simultaneous detection of viral antibodies.

    Directory of Open Access Journals (Sweden)

    Yi Liu

    Full Text Available Protein microarrays have been developed to study antibody reactivity against a large number of antigens, demonstrating extensive perspective for clinical application. We developed a viral antigen array by spotting four recombinant antigens and synthetic peptide, including glycoprotein G of herpes simplex virus (HSV type 1 and 2, phosphoprotein 150 of cytomegalovirus (CMV, Rubella virus (RV core plus glycoprotein E1 and E2 as well as a E1 peptide with the optimal concentrations on activated glass slides to simultaneously detect IgG and IgM against HSV1, HSV2, CMV and RV in clinical specimens of sera and cerebrospinal fluids (CSFs. The positive reference sera were initially used to measure the sensitivity and specificity of the array with the optimal conditions. Then clinical specimens of 144 sera and 93 CSFs were tested for IgG and IgM antibodies directed against HSV1, HSV2, CMV and RV by the antigen array. Specificity of the antigen array for viral antibodies detection was satisfying compared to commercial ELISA kits but sensitivity of the array varied relying on quality and antigenic epitopes of the spotting antigens. In short, the recombinant antigen array has potential to simultaneous detect multiple viral antibodies using minute amount (3 µl of samples, which holds the particularly advantage to detect viral antibodies in clinical CSFs being suspicious of neonatal meningitis and encephalitis.

  15. Nonreplicative RNA Recombination of an Animal Plus-Strand RNA Virus in the Absence of Efficient Translation of Viral Proteins

    Science.gov (United States)

    Kleine Büning, Maximiliane; Meyer, Denise; Austermann-Busch, Sophia; Roman-Sosa, Gleyder; Rümenapf, Tillmann

    2017-01-01

    RNA recombination is a major driving force for the evolution of RNA viruses and is significantly implicated in the adaptation of viruses to new hosts, changes of virulence, as well as in the emergence of new viruses including drug-resistant and escape mutants. However, the molecular details of recombination in animal RNA viruses are only poorly understood. In order to determine whether viral RNA recombination depends on translation of viral proteins, a nonreplicative recombination system was established which is based on cotransfection of cells with synthetic bovine viral diarrhea virus (family Flaviviridae) RNA genome fragments either lacking the internal ribosome entry site required for cap-independent translation or lacking almost the complete polyprotein coding region. The emergence of a number of recombinant viruses demonstrated that IRES-mediated translation of viral proteins is dispensable for efficient recombination and suggests that RNA recombination can occur in the absence of viral proteins. Analyses of 58 independently emerged viruses led to the detection of recombinant genomes with duplications, deletions and insertions in the 5′ terminal region of the open reading frame, leading to enlarged core fusion proteins detectable by Western blot analysis. This demonstrates a remarkable flexibility of the pestivirus core protein. Further experiments with capped and uncapped genome fragments containing a luciferase gene for monitoring the level of protein translation revealed that even a ∼1,000-fold enhancement of translation of viral proteins did not increase the frequency of RNA recombination. Taken together, this study highlights that nonreplicative RNA recombination does not require translation of viral proteins. PMID:28338950

  16. Direct facile screening of recombinant DNA vector constructs.

    Science.gov (United States)

    Winnard, Paul T; Challa, Rushi; Bhujwalla, Zaver M; Raman, Venu

    2014-04-01

    Direct efficient facile screening of bacterial transformants with the goal of selecting, retrieving, and using recombinant DNA is exemplified by simple visual-based colorimetric inspections or fluorescent protein-based assays. We describe pRedScript, which introduces the constitutive expression of a very bright red fluorescent protein into transformants. On agar plates, red colonies are simply visualized in ambient white light in stark contrast to recombinant transformants that are white. In addition, the bright red fluorescence of the reporter protein can also be harnessed as a sensitive signal for screening bacterial promoters during the development of optimized fermentation conditions.

  17. Construction and identification of recombination expression vector Ksp-Cadherin-Gpx1-Klk1

    Institute of Scientific and Technical Information of China (English)

    解立怡; 薛武军; 项和立; 麻孙凯

    2008-01-01

    Objective To construct and identify the Gpx1-Klk1 vector which contains kidney-specific promoter (Ksp-cadherin). Methods Through PCR amplification, the human Gpx1, Klk1, and Ksp-cadherin cDNA were obtained by taking Gpx1 cDNA, Klk1 cDNA, and Ksp-cadherin BAC as templates. After being testified, the PCR products were inserted into the expressive vector pIRES-EGFP step-by-step to produce a recombinant vector Ksp-cadherin-Gpx1-Klk1. This vector was examined by restriction enzyme digestion and sequence analysis...

  18. The proteasomal Rpn11 metalloprotease suppresses tombusvirus RNA recombination and promotes viral replication via facilitating assembly of the viral replicase complex.

    Science.gov (United States)

    Prasanth, K Reddisiva; Barajas, Daniel; Nagy, Peter D

    2015-03-01

    RNA viruses co-opt a large number of cellular proteins that affect virus replication and, in some cases, viral genetic recombination. RNA recombination helps viruses in an evolutionary arms race with the host's antiviral responses and adaptation of viruses to new hosts. Tombusviruses and a yeast model host are used to identify cellular factors affecting RNA virus replication and RNA recombination. In this study, we have examined the role of the conserved Rpn11p metalloprotease subunit of the proteasome, which couples deubiquitination and degradation of proteasome substrates, in tombusvirus replication and recombination in Saccharomyces cerevisiae and plants. Depletion or mutations of Rpn11p lead to the rapid formation of viral RNA recombinants in combination with reduced levels of viral RNA replication in yeast or in vitro based on cell extracts. Rpn11p interacts with the viral replication proteins and is recruited to the viral replicase complex (VRC). Analysis of the multifunctional Rpn11p has revealed that the primary role of Rpn11p is to act as a "matchmaker" that brings the viral p92(pol) replication protein and the DDX3-like Ded1p/RH20 DEAD box helicases into VRCs. Overexpression of Ded1p can complement the defect observed in rpn11 mutant yeast by reducing TBSV recombination. This suggests that Rpn11p can suppress tombusvirus recombination via facilitating the recruitment of the cellular Ded1p helicase, which is a strong suppressor of viral recombination, into VRCs. Overall, this work demonstrates that the co-opted Rpn11p, which is involved in the assembly of the functional proteasome, also functions in the proper assembly of the tombusvirus VRCs. RNA viruses evolve rapidly due to genetic changes based on mutations and RNA recombination. Viral genetic recombination helps viruses in an evolutionary arms race with the host's antiviral responses and facilitates adaptation of viruses to new hosts. Cellular factors affect viral RNA recombination, although the role

  19. Efficient Transient Expression of Recombinant Proteins in Plants by the Novel pEff Vector Based on the Genome of Potato Virus X

    Science.gov (United States)

    Mardanova, Eugenia S.; Blokhina, Elena A.; Tsybalova, Liudmila M.; Peyret, Hadrien; Lomonossoff, George P.; Ravin, Nikolai V.

    2017-01-01

    Agroinfiltration of plant leaves with binary vectors carrying a gene of interest within a plant viral vector is a rapid and efficient method for protein production in plants. Previously, we constructed a self-replicating vector, pA7248AMV, based on the genetic elements of potato virus X (PVX), and have shown that this vector can be used for the expression of recombinant proteins in Nicotiana benthamiana. However, this vector is almost 18 kb long and therefore not convenient for genetic manipulation. Furthermore, for efficient expression of the target protein it should be co-agroinfiltrated with an additional binary vector expressing a suppressor of post-transcriptional gene silencing. Here, we improved this expression system by creating the novel pEff vector. Its backbone is about 5 kb shorter than the original vector and it contains an expression cassette for the silencing suppressor, P24, from grapevine leafroll-associated virus-2 alongside PVX genetic elements, thus eliminating the need of co-agroinfiltration. The pEff vector provides green fluorescent protein expression levels of up to 30% of total soluble protein. The novel vector was used for expression of the influenza vaccine candidate, M2eHBc, consisting of an extracellular domain of influenza virus M2 protein (M2e) fused to hepatitis B core antigen. Using the pEff system, M2eHBc was expressed to 5–10% of total soluble protein, several times higher than with original pA7248AMV vector. Plant-produced M2eHBc formed virus-like particles in vivo, as required for its use as a vaccine. The new self-replicating pEff vector could be used for fast and efficient production of various recombinant proteins in plants. PMID:28293244

  20. Semliki Forest Virus: un vector viral con múltiples aplicaciones

    OpenAIRE

    2007-01-01

    Se han utilizado los alfavirus como vectores de expresión, entre estos se encuentra el Semliki Forest virus (SFV), que es un virus envuelto, el cual, además de replicarse en el citoplasma, tiene la propiedad de expresar por separado las proteínas estructurales de las no estructurales, permitiendo un mayor control de la expresión. Los vectores derivados del SFV pueden tener una gama amplia de aplicaciones. Se pueden obtener altos títulos virales para la expresión eficiente de proteínas en dife...

  1. A nano particle vector comprised of poly lactic-co-glycolic acid and monophosphoryl lipid A and recombinant Mycobacterium avium subsp paratuberculosis peptides stimulate a pro-immune profile in bovine macrophages

    Science.gov (United States)

    Current research and development of antigens for vaccination often center on purified recombinant proteins, viral vectored subunits, and synthetic peptides, most of which suffer from poor immunogenicity and are subject to degradation. For these reasons, efficient delivery systems and potent immunost...

  2. Adeno-Associated Viral Vectors Transduce Mature Human Adipocytes in Three-Dimensional Slice Cultures.

    Science.gov (United States)

    Kallendrusch, Sonja; Schopow, Nikolas; Stadler, Sonja C; Büning, Hildegard; Hacker, Ulrich T

    2016-10-01

    Adipose tissue plays a pivotal role, both in the regulation of energy homeostasis and as an endocrine organ. Consequently, adipose tissue dysfunction is closely related to insulin resistance, morbid obesity, and metabolic syndrome. To study molecular mechanisms and to develop novel therapeutic strategies, techniques are required to genetically modify mature adipocytes. Here, we report on adeno-associated viral (AAV) vectors as a versatile tool to transduce human mature adipocytes in organotypic three-dimensional tissue cultures.

  3. Heterologous viral expression systems in fosmid vectors increase the functional analysis potential of metagenomic libraries

    OpenAIRE

    2013-01-01

    The extraordinary potential of metagenomic functional analyses to identify activities of interest present in uncultured microorganisms has been limited by reduced gene expression in surrogate hosts. We have developed vectors and specialized E. coli strains as improved metagenomic DNA heterologous expression systems, taking advantage of viral components that prevent transcription termination at metagenomic terminators. One of the systems uses the phage T7 RNA-polymerase to drive metagenomic ge...

  4. A comparative analysis of constitutive promoters located in adeno-associated viral vectors.

    Directory of Open Access Journals (Sweden)

    Lkhagvasuren Damdindorj

    Full Text Available The properties of constitutive promoters within adeno-associated viral (AAV vectors have not yet been fully characterized. In this study, AAV vectors, in which enhanced GFP expression was directed by one of the six constitutive promoters (human β-actin, human elongation factor-1α, chicken β-actin combined with cytomegalovirus early enhancer, cytomegalovirus (CMV, simian virus 40, and herpes simplex virus thymidine kinase, were constructed and introduced into the HCT116, DLD-1, HT-1080, and MCF-10A cell lines. Quantification of GFP signals in infected cells demonstrated that the CMV promoter produced the highest GFP expression in the six promoters and maintained relatively high GFP expression for up to eight weeks after infection of HCT116, DLD-1, and HT-1080. Exogenous human CDKN2A gene expression was also introduced into DLD-1 and MCF-10A in a similar pattern by using AAV vectors bearing the human β-actin and the CMV promoters. The six constitutive promoters were subsequently placed upstream of the neomycin resistance gene within AAV vectors, and HCT116, DLD-1, and HT-1080 were infected with the resulting vectors. Of the six promoters, the CMV promoter produced the largest number of G418-resistant colonies in all three cell lines. Because AAV vectors have been frequently used as a platform to construct targeting vectors that permit gene editing in human cell lines, we lastly infected the three cell lines with AAV-based targeting vectors against the human PIGA gene in which one of the six promoters regulate the neomycin resistance gene. This assay revealed that the CMV promoter led to the lowest PIGA gene targeting efficiency in the investigated promoters. These results provide a clue to the identification of constitutive promoters suitable to express exogenous genes with AAV vectors, as well as those helpful to conduct efficient gene targeting using AAV-based targeting vectors in human cell lines.

  5. Carbohydrate-Based Ice Recrystallization Inhibitors Increase Infectivity and Thermostability of Viral Vectors

    Science.gov (United States)

    Ghobadloo, Shahrokh M.; Balcerzak, Anna K.; Gargaun, Ana; Muharemagic, Darija; Mironov, Gleb G.; Capicciotti, Chantelle J.; Briard, Jennie G.; Ben, Robert N.; Berezovski, Maxim V.

    2014-07-01

    The inability of vaccines to retain sufficient thermostability has been an obstacle to global vaccination programs. To address this major limitation, we utilized carbohydrate-based ice recrystallization inhibitors (IRIs) to eliminate the cold chain and stabilize the potency of Vaccinia virus (VV), Vesicular Stomatitis virus (VSV) and Herpes virus-1 (HSV-1). The impact of these IRIs was tested on the potency of the viral vectors using a plaque forming unit assay following room temperature storage, cryopreservation with successive freeze-thaw cycles and lyophilization. Viral potency after storage with all three conditions demonstrated that N-octyl-gluconamide (NOGlc) recovered the infectivity of shelf stored VV, 5.6 Log10 PFU mL-1 during 40 days, and HSV-1, 2.7 Log10 PFU mL-1 during 9 days. Carbon-linked antifreeze glycoprotein analogue ornithine-glycine-glycine-galactose (OGG-Gal) increases the recovery of VV and VSV more than 1 Log10 PFU mL-1 after 10 freeze-thaw cycles. In VSV, cryostorage with OGG-Gal maintains high infectivity and reduces temperature-induced aggregation of viral particles by 2 times that of the control. In total, OGG-Gal and NOGlc preserve virus potency during cryostorage. Remarkably, NOGlc has potential to eliminate the cold chain and permit room temperature storage of viral vectors.

  6. Carbohydrate-based ice recrystallization inhibitors increase infectivity and thermostability of viral vectors.

    Science.gov (United States)

    Ghobadloo, Shahrokh M; Balcerzak, Anna K; Gargaun, Ana; Muharemagic, Darija; Mironov, Gleb G; Capicciotti, Chantelle J; Briard, Jennie G; Ben, Robert N; Berezovski, Maxim V

    2014-07-31

    The inability of vaccines to retain sufficient thermostability has been an obstacle to global vaccination programs. To address this major limitation, we utilized carbohydrate-based ice recrystallization inhibitors (IRIs) to eliminate the cold chain and stabilize the potency of Vaccinia virus (VV), Vesicular Stomatitis virus (VSV) and Herpes virus-1 (HSV-1). The impact of these IRIs was tested on the potency of the viral vectors using a plaque forming unit assay following room temperature storage, cryopreservation with successive freeze-thaw cycles and lyophilization. Viral potency after storage with all three conditions demonstrated that N-octyl-gluconamide (NOGlc) recovered the infectivity of shelf stored VV, 5.6 Log₁₀ PFU mL(-1) during 40 days, and HSV-1, 2.7 Log₁₀ PFU mL(-1) during 9 days. Carbon-linked antifreeze glycoprotein analogue ornithine-glycine-glycine-galactose (OGG-Gal) increases the recovery of VV and VSV more than 1 Log₁₀ PFU mL(-1) after 10 freeze-thaw cycles. In VSV, cryostorage with OGG-Gal maintains high infectivity and reduces temperature-induced aggregation of viral particles by 2 times that of the control. In total, OGG-Gal and NOGlc preserve virus potency during cryostorage. Remarkably, NOGlc has potential to eliminate the cold chain and permit room temperature storage of viral vectors.

  7. Viral vectors for cystic fibrosis gene therapy: What does the future hold?

    Directory of Open Access Journals (Sweden)

    Uta Griesenbach

    2010-12-01

    Full Text Available Uta Griesenbach1, Makoto Inoue2, Mamoru Hasegawa2, Eric WFW Alton11Department of Gene Therapy, Imperial College London, UK; The UK Cystic Fibrosis Gene Therapy Consortium; 2DNAVEC Corporation, Tsukuba, JapanAbstract: Gene transfer to the airway epithelium has been more difficult than originally anticipated, largely because of significant extra- and intracellular barriers in the lung. In general, viral vectors are more adapted to overcoming these barriers than nonviral gene transfer agents and are, therefore, more efficient in transferring genes into recipient cells. Viral vectors derived from adenovirus, adeno-associated virus, and Sendai virus, which all have a natural tropism for the airway epithelium, have been evaluated for cystic fibrosis (CF gene therapy. Although these vectors transduce airway epithelial cells efficiently, gene expression is transient and repeated administration is inefficient. They are, therefore, unlikely to be suitable for CF gene therapy. More recently, lentiviruses (LV have been assessed for lung gene transfer. In contrast to retroviruses, they transduce nondividing cells and randomly integrate into the genome. However, LVs do not have a natural tropism for the lung, and a significant amount of effort has been put into pseudotyping these vectors with proteins suitable for airway gene transfer. Several studies have shown that LV-mediated transduction leads to persistent gene expression (for the lifetime of the animal in the airways and, importantly, repeated administration is feasible. Thus, appropriately pseudotyped LV vectors are promising candidates for CF gene therapy. Here, we will review preclinical and clinical research related to viral CF gene therapy.Keywords: cystic fibrosis, gene therapy, adenovirus, AAV, lentivirus, Sendai virus

  8. Immunogenicity of the recombinant adenovirus type 5 vector with type 35 fiber containing HIV-1 gag gene

    Institute of Scientific and Technical Information of China (English)

    XIN LEI LIU; SHUNAG QING YU; XIA FENG; XIAO LI WANG; HONG MEI LIU; XIAO MEI ZHANG; HONG XIA LI; LING ZHOU; YI ZENG

    2006-01-01

    The immune efficiency of a recombinant adenovirus type 5 with type 35 fiber containing HIV-1 gag gene (rAd5/F35-mod.gag) was investigated in BALB/c mice, in which the rAd5/F35-mod. gag was firstly identified with PCR, then transfected to 293 cells and the in vitro expression level of Gag protein was determined by Western blotting and indirect immuno-fluorescent assay. Mice were immunized with intramuscular injections of rAd5/F35-mod. gag, rAd5-mod. gag or DNA and were boosted after 3 weeks.To test the effect of pre-existing anti-viral immunity on immunization, mice were also injected with Ad5-GFP vector and then immunized 4 and 7 weeks later with Ad5/F35-mod. gag vector. The P24-specific IgG antibody in sera of immunized mice was determined by ELISA and the specific cytotoxic T lymphocyte (CTL) response was assayed by intracellular cytokine staining. It was demonstrated that the rAd5/F35-mod. gag vector could express efficiently the HIV Gag protein in 293 cells in vitro and induce strong HIVspecific immune responses in vivo. The strongest CTL and serum IgG response occurred when mice were immunized twice with injection of rAd5/F35 alone, but the anti-Ad5 antibody after primary infection with adenovirus could inhibit the specific immune responses induced by rAd5/F35 vector. It is concluded that single immunization with recombinant adenovirus rAd5/F35-mod. gag can induce specific CTL and serum IgG antibody responses in mice, but the immunogenicity of rAd5/F35 is comparably weaker than that of rAd5.

  9. Widespread recombination, reassortment, and transmission of unbalanced compound viral genotypes in natural arenavirus infections.

    Science.gov (United States)

    Stenglein, Mark D; Jacobson, Elliott R; Chang, Li-Wen; Sanders, Chris; Hawkins, Michelle G; Guzman, David S-M; Drazenovich, Tracy; Dunker, Freeland; Kamaka, Elizabeth K; Fisher, Debbie; Reavill, Drury R; Meola, Linda F; Levens, Gregory; DeRisi, Joseph L

    2015-05-01

    Arenaviruses are one of the largest families of human hemorrhagic fever viruses and are known to infect both mammals and snakes. Arenaviruses package a large (L) and small (S) genome segment in their virions. For segmented RNA viruses like these, novel genotypes can be generated through mutation, recombination, and reassortment. Although it is believed that an ancient recombination event led to the emergence of a new lineage of mammalian arenaviruses, neither recombination nor reassortment has been definitively documented in natural arenavirus infections. Here, we used metagenomic sequencing to survey the viral diversity present in captive arenavirus-infected snakes. From 48 infected animals, we determined the complete or near complete sequence of 210 genome segments that grouped into 23 L and 11 S genotypes. The majority of snakes were multiply infected, with up to 4 distinct S and 11 distinct L segment genotypes in individual animals. This S/L imbalance was typical: in all cases intrahost L segment genotypes outnumbered S genotypes, and a particular S segment genotype dominated in individual animals and at a population level. We corroborated sequencing results by qRT-PCR and virus isolation, and isolates replicated as ensembles in culture. Numerous instances of recombination and reassortment were detected, including recombinant segments with unusual organizations featuring 2 intergenic regions and superfluous content, which were capable of stable replication and transmission despite their atypical structures. Overall, this represents intrahost diversity of an extent and form that goes well beyond what has been observed for arenaviruses or for viruses in general. This diversity can be plausibly attributed to the captive intermingling of sub-clinically infected wild-caught snakes. Thus, beyond providing a unique opportunity to study arenavirus evolution and adaptation, these findings allow the investigation of unintended anthropogenic impacts on viral ecology

  10. Widespread recombination, reassortment, and transmission of unbalanced compound viral genotypes in natural arenavirus infections.

    Directory of Open Access Journals (Sweden)

    Mark D Stenglein

    2015-05-01

    Full Text Available Arenaviruses are one of the largest families of human hemorrhagic fever viruses and are known to infect both mammals and snakes. Arenaviruses package a large (L and small (S genome segment in their virions. For segmented RNA viruses like these, novel genotypes can be generated through mutation, recombination, and reassortment. Although it is believed that an ancient recombination event led to the emergence of a new lineage of mammalian arenaviruses, neither recombination nor reassortment has been definitively documented in natural arenavirus infections. Here, we used metagenomic sequencing to survey the viral diversity present in captive arenavirus-infected snakes. From 48 infected animals, we determined the complete or near complete sequence of 210 genome segments that grouped into 23 L and 11 S genotypes. The majority of snakes were multiply infected, with up to 4 distinct S and 11 distinct L segment genotypes in individual animals. This S/L imbalance was typical: in all cases intrahost L segment genotypes outnumbered S genotypes, and a particular S segment genotype dominated in individual animals and at a population level. We corroborated sequencing results by qRT-PCR and virus isolation, and isolates replicated as ensembles in culture. Numerous instances of recombination and reassortment were detected, including recombinant segments with unusual organizations featuring 2 intergenic regions and superfluous content, which were capable of stable replication and transmission despite their atypical structures. Overall, this represents intrahost diversity of an extent and form that goes well beyond what has been observed for arenaviruses or for viruses in general. This diversity can be plausibly attributed to the captive intermingling of sub-clinically infected wild-caught snakes. Thus, beyond providing a unique opportunity to study arenavirus evolution and adaptation, these findings allow the investigation of unintended anthropogenic impacts on

  11. Mucosal vaccination with heterologous viral vectored vaccine targeting subdominant SIV accessory antigens strongly inhibits early viral replication

    DEFF Research Database (Denmark)

    Xu, Huanbin; Andersson, Anne-Marie Carola; Ragonnaud, Emeline

    2017-01-01

    Conventional HIV T cell vaccine strategies have not been successful in containing acute peak viremia, nor in providing long-term control. We immunized rhesus macaques intramuscularly and rectally using a heterologous adenovirus vectored SIV vaccine regimen encoding normally weakly immunogenic tat......, vif, rev and vpr antigens fused to the MHC class II associated invariant chain. Immunizations induced broad T cell responses in all vaccinees. Following up to 10 repeated low-dose intrarectal challenges, vaccinees suppressed early viral replication (P=0.01) and prevented the peak viremia in 5....../6 animals. Despite consistently undetectable viremia in 2 out of 6 vaccinees, all animals showed evidence of infection induced immune responses indicating that infection had taken place. Vaccinees, with and without detectable viremia better preserved their rectal CD4+ T cell population and had reduced...

  12. Molecular genetics of DNA viruses: recombinant virus technology.

    Science.gov (United States)

    Neuhierl, Bernhard; Delecluse, Henri-Jacques

    2005-01-01

    Recombinant viral genomes cloned onto BAC vectors can be subjected to extensive molecular genetic analysis in the context of E. coli. Thus, the recombinant virus technology exploits the power of prokaryotic genetics to introduce all kinds of mutations into the recombinant genome. All available techniques are based on homologous recombination between a targeting vector carrying the mutated version of the gene of interest and the recombinant virus. After modification, the mutant viral genome is stably introduced into eukaryotic cells permissive for viral lytic replication. In these cells, mutant viral genomes can be packaged into infectious particles to evaluate the effect of these mutations in the context of the complete genome.

  13. Herpes simplex virus type 1 (HSV-1)-derived recombinant vectors for gene transfer and gene therapy.

    Science.gov (United States)

    Marconi, Peggy; Fraefel, Cornel; Epstein, Alberto L

    2015-01-01

    Herpes simplex virus type 1 (HSV-1 ) is a human pathogen whose lifestyle is based on a long-term dual interaction with the infected host, being able to establish both lytic and latent infections. The virus genome is a 153-kilobase pair (kbp) double-stranded DNA molecule encoding more than 80 genes. The interest of HSV-1 as gene transfer vector stems from its ability to infect many different cell types, both quiescent and proliferating cells, the very high packaging capacity of the virus capsid, the outstanding neurotropic adaptations that this virus has evolved, and the fact that it never integrates into the cellular chromosomes, thus avoiding the risk of insertional mutagenesis. Two types of vectors can be derived from HSV-1, recombinant vectors and amplicon vectors, and different methodologies have been developed to prepare large stocks of each type of vector. This chapter summarizes the approach most commonly used to prepare recombinant HSV-1 vectors through homologous recombination, either in eukaryotic cells or in bacteria.

  14. Construction of pPIC9 Recombinant Vector Containing Human Stem Cell Factor

    Directory of Open Access Journals (Sweden)

    Behrooz Farhadi

    2013-08-01

    Full Text Available Purpose: Various cytokine regulates hematopoesis; they promote number of stages in stem cells biology such as proliferation, differentiation and endurance. Biological effects of SCF, as a hematopoietic cytokine; is triggered by binding to its ligand c-kit. Potential therapeutic applications of SCF include hematopoietic stem cell mobilization, exvivo stem/progenitor cell expansion, gene therapy, and immunotherapy. In this study we tried to construct of pPIC9 recombinant vector containing human SCF. Methods: hSCF cDNA was amplified by PCR and both hSCF cDNA and pPIC9 as yeast expression vector (shuttle vector digested by EcoR I and Xho I restriction enzymes. Subsequent the digestion reaction, ligation reaction was carried out. In order to verifying of pPIC9 recombinant vector containing hSCF, PCR and sequence analysis was performed. Results: The construction of recombinant expression vector of pPIC9 containing hSCF cDNA was confirmed by sequencing method successfully. Conclusion: rhSCF/pPIC9 vector can be transformed into the Picha pastoris yeast as a eukaryotic host in order to produce human SCF at industrial scale.

  15. Disruption of vector transmission by a plant-expressed viral glycoprotein.

    Science.gov (United States)

    Montero-Astúa, Mauricio; Rotenberg, Dorith; Leach-Kieffaber, Alexandria; Schneweis, Brandi A; Park, Sunghun; Park, Jungeun K; German, Thomas L; Whitfield, Anna E

    2014-03-01

    Vector-borne viruses are a threat to human, animal, and plant health worldwide, requiring the development of novel strategies for their control. Tomato spotted wilt virus (TSWV) is one of the 10 most economically significant plant viruses and, together with other tospoviruses, is a threat to global food security. TSWV is transmitted by thrips, including the western flower thrips, Frankliniella occidentalis. Previously, we demonstrated that the TSWV glycoprotein GN binds to thrips vector midguts. We report here the development of transgenic plants that interfere with TSWV acquisition and transmission by the insect vector. Tomato plants expressing GN-S protein supported virus accumulation and symptom expression comparable with nontransgenic plants. However, virus titers in larval insects exposed to the infected transgenic plants were three-log lower than insects exposed to infected nontransgenic control plants. The negative effect of the GN-S transgenics on insect virus titers persisted to adulthood, as shown by four-log lower virus titers in adults and an average reduction of 87% in transmission efficiencies. These results demonstrate that an initial reduction in virus infection of the insect can result in a significant decrease in virus titer and transmission over the lifespan of the vector, supportive of a dose-dependent relationship in the virus-vector interaction. These findings demonstrate that plant expression of a viral protein can be an effective way to block virus transmission by insect vectors.

  16. A preferred region for recombinational patch repair in the 5' untranslated region of primer binding site-impaired murine leukemia virus vectors

    DEFF Research Database (Denmark)

    Mikkelsen, J G; Lund, Anders Henrik; Kristensen, K D;

    1996-01-01

    with that of the wild-type vector. Thirty-two of 60 transduced proviruses analyzed harbored a primer binding site sequence matching a glutamine tRNA primer. Sequence analysis of the regions flanking the glutamine tRNA primer binding site revealed a distinct pattern of nucleotide differences from the Akv-based vector...... at or around the glutamine tRNA primer binding site. We propose that the forced recombination of primer binding site mutants involves initial priming on endogenous viral sequences and requires template switching during minus-strand synthesis in the region between the neo gene and the mutated primer binding......, suggesting the involvement of a specific endogenous virus-like sequence in patch repair rescue of the primer binding site mutants. The putative recombination partner RNA was found in virions from psi-2 cells as detected by analysis of glutamine tRNA-initiated cDNA and by sequence analysis of regions...

  17. Viral and vector zoonotic exploitation of a homo-sociome memetic complex.

    Science.gov (United States)

    Rupprecht, C E; Burgess, G W

    2015-05-01

    As most newly characterized emerging infectious diseases are considered to be zoonotic, a modern pre-eminence ascribed within this classification lies clearly within the viral taxonomic realm. In particular, RNA viruses deserve special concern given their documented impact on conservation biology, veterinary medicine and public health, with an unprecedented ability to promote an evolutionary host-pathogen arms race from the ultimate infection and immunity perspective. However, besides the requisite molecular/gross anatomical and physiological bases for infectious diseases to transmit from one host to another, both viral pathogens and their reservoirs/vectors exploit a complex anthropological, cultural, historical, psychological and social suite that specifically defines the phylodynamics within Homo sapiens, unlike any other species. Some of these variables include the ecological benefits of living in groups, decisions on hunting and foraging behaviours and dietary preferences, myths and religious doctrines, health economics, travel destinations, population planning, political decisions on agricultural product bans and many others, in a homo-sociome memetic complex. Taken to an extreme, such complexities elucidate the underpinnings of explanations as to why certain viral zoonoses reside in neglected people, places and things, whereas others are chosen selectively and prioritized for active mitigation. Canine-transmitted rabies serves as one prime example of how a neglected viral zoonosis may transition to greater attention on the basis of renewed advocacy, social media, local champions and vested international community engagement. In contrast, certain bat-associated and arboviral diseases suffer from basic ignorance and perpetuated misunderstanding of fundamental reservoir and vector ecology tenets, translated into failed control policies that only exacerbate the underlying environmental conditions of concern. Beyond applied biomedical knowledge, epidemiological

  18. Recombinant vesicular stomatitis virus vector mediates postexposure protection against Sudan Ebola hemorrhagic fever in nonhuman primates.

    Science.gov (United States)

    Geisbert, Thomas W; Daddario-DiCaprio, Kathleen M; Williams, Kinola J N; Geisbert, Joan B; Leung, Anders; Feldmann, Friederike; Hensley, Lisa E; Feldmann, Heinz; Jones, Steven M

    2008-06-01

    Recombinant vesicular stomatitis virus (VSV) vectors expressing homologous filoviral glycoproteins can completely protect rhesus monkeys against Marburg virus when administered after exposure and can partially protect macaques after challenge with Zaire ebolavirus. Here, we administered a VSV vector expressing the Sudan ebolavirus (SEBOV) glycoprotein to four rhesus macaques shortly after exposure to SEBOV. All four animals survived SEBOV challenge, while a control animal that received a nonspecific vector developed fulminant SEBOV hemorrhagic fever and succumbed. This is the first demonstration of complete postexposure protection against an Ebola virus in nonhuman primates and provides further evidence that postexposure vaccination may have utility in treating exposures to filoviruses.

  19. Construction and characterization of calreticulin-HBsAg fusion gene recombinant adenovirus expression vector

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    AIM: To generate recombinant adenoviral vector con-taining calreticulin (CRT)-hepatitis B surface antigen (HBsAg) fusion gene for developing a safe, effective and HBsAg-specific therapeutic vaccine.METHODS: CRT and HBsAg gene were fused using polymerase chain reaction (PCR), endonuclease diges-tion and ligation methods. The fusion gene was cloned into pENTR/D-TOPO transfer vector after the base pairs of DNA (CACC) sequence was added to the 5′ end. Adenoviral expression vector containing CRT-HBsAg fusion gen...

  20. Canine Enteric Coronaviruses: Emerging Viral Pathogens with Distinct Recombinant Spike Proteins

    Directory of Open Access Journals (Sweden)

    Beth N. Licitra

    2014-08-01

    Full Text Available Canine enteric coronavirus (CCoV is an alphacoronavirus infecting dogs that is closely related to enteric coronaviruses of cats and pigs. While CCoV has traditionally caused mild gastro-intestinal clinical signs, there are increasing reports of lethal CCoV infections in dogs, with evidence of both gastrointestinal and systemic viral dissemination. Consequently, CCoV is now considered to be an emerging infectious disease of dogs. In addition to the two known serotypes of CCoV, novel recombinant variants of CCoV have been found containing spike protein N-terminal domains (NTDs that are closely related to those of feline and porcine strains. The increase in disease severity in dogs and the emergence of novel CCoVs can be attributed to the high level of recombination within the spike gene that can occur during infection by more than one CCoV type in the same host.

  1. Viral meningitis epidemics and a single, recent, recombinant and anthroponotic origin of swine vesicular disease virus

    DEFF Research Database (Denmark)

    Bruhn, Christian Anders Wathne; Nielsen, Sandra Cathrine Abel; Samaniego Castruita, Jose Alfredo;

    2015-01-01

    BACKGROUND AND OBJECTIVES: Swine vesicular disease virus (SVDV) is a close relative of the human Enterovirus B serotype, coxsackievirus B5. As the etiological agent of a significant emergent veterinary disease, several studies have attempted to explain its origin. However, several key questions r...... stating that SVDV originated through co-infection, recombination, and a single anthroponotic event, during large viral meningitis epidemics around 1960/1961 involving the ancestral serotypes. The exact geographical origin of SVDV may remain untestable due to historical aspects....

  2. pEPito: a significantly improved non-viral episomal expression vector for mammalian cells

    Directory of Open Access Journals (Sweden)

    Ogris Manfred

    2010-03-01

    Full Text Available Abstract Background The episomal replication of the prototype vector pEPI-1 depends on a transcription unit starting from the constitutively expressed Cytomegalovirus immediate early promoter (CMV-IEP and directed into a 2000 bp long matrix attachment region sequence (MARS derived from the human β-interferon gene. The original pEPI-1 vector contains two mammalian transcription units and a total of 305 CpG islands, which are located predominantly within the vector elements necessary for bacterial propagation and known to be counterproductive for persistent long-term transgene expression. Results Here, we report the development of a novel vector pEPito, which is derived from the pEPI-1 plasmid replicon but has considerably improved efficacy both in vitro and in vivo. The pEPito vector is significantly reduced in size, contains only one transcription unit and 60% less CpG motives in comparison to pEPI-1. It exhibits major advantages compared to the original pEPI-1 plasmid, including higher transgene expression levels and increased colony-forming efficiencies in vitro, as well as more persistent transgene expression profiles in vivo. The performance of pEPito-based vectors was further improved by replacing the CMV-IEP with the human CMV enhancer/human elongation factor 1 alpha promoter (hCMV/EF1P element that is known to be less affected by epigenetic silencing events. Conclusions The novel vector pEPito can be considered suitable as an improved vector for biotechnological applications in vitro and for non-viral gene delivery in vivo.

  3. Recombinant Ag85B vaccine by taking advantage of characteristics of human parainfluenza type 2 virus vector showed Mycobacteria-specific immune responses by intranasal immunization.

    Science.gov (United States)

    Watanabe, Kenta; Matsubara, Akihiro; Kawano, Mitsuo; Mizuno, Satoru; Okamura, Tomotaka; Tsujimura, Yusuke; Inada, Hiroyasu; Nosaka, Tetsuya; Matsuo, Kazuhiro; Yasutomi, Yasuhiro

    2014-03-26

    Viral vectors are promising vaccine candidates for eliciting suitable Ag-specific immune response. Since Mycobacterium tuberculosis (Mtb) normally enters hosts via the mucosal surface of the lung, the best defense against Mtb is mucosal vaccines that are capable of inducing both systemic and mucosal immunity. Although Mycobacterium bovis bacille Calmette-Guérin is the only licensed tuberculosis (TB) vaccine, its efficacy against adult pulmonary forms of TB is variable. In this study, we assessed the effectiveness of a novel mucosal TB vaccine using recombinant human parainfluenza type 2 virus (rhPIV2) as a vaccine vector in BALB/c mice. Replication-incompetent rhPIV2 (M gene-eliminated) expressing Ag85B (rhPIV2-Ag85B) was constructed by reverse genetics technology. Intranasal administration of rhPIV2-Ag85B induced Mtb-specific immune responses, and the vaccinated mice showed a substantial reduction in the number of CFU of Mtb in lungs and spleens. Unlike other viral vaccine vectors, the immune responses against Ag85B induced by rhPIV2-Ag85B immunization had an advantage over that against the viral vector. In addition, it was revealed that rhPIV2-Ag85B in itself has an adjuvant activity through the retinoic acid-inducible gene I receptor. These findings provide further evidence for the possibility of rhPIV2-Ag85B as a novel TB vaccine.

  4. Subcloning plus insertion (SPI)--a novel recombineering method for the rapid construction of gene targeting vectors.

    Science.gov (United States)

    Reddy, Thimma R; Kelsall, Emma J; Fevat, Léna M S; Munson, Sarah E; Cowley, Shaun M

    2015-01-08

    Gene targeting refers to the precise modification of a genetic locus using homologous recombination. The generation of novel cell lines and transgenic mouse models using this method necessitates the construction of a 'targeting' vector, which contains homologous DNA sequences to the target gene, and has for many years been a limiting step in the process. Vector construction can be performed in vivo in Escherichia coli cells using homologous recombination mediated by phage recombinases using a technique termed recombineering. Recombineering is the preferred technique to subclone the long homology sequences (>4 kb) and various targeting elements including selection markers that are required to mediate efficient allelic exchange between a targeting vector and its cognate genomic locus. Typical recombineering protocols follow an iterative scheme of step-wise integration of the targeting elements and require intermediate purification and transformation steps. Here, we present a novel recombineering methodology of vector assembly using a multiplex approach. Plasmid gap repair is performed by the simultaneous capture of genomic sequence from mouse Bacterial Artificial Chromosome libraries and the insertion of dual bacterial and mammalian selection markers. This subcloning plus insertion method is highly efficient and yields a majority of correct recombinants. We present data for the construction of different types of conditional gene knockout, or knock-in, vectors and BAC reporter vectors that have been constructed using this method. SPI vector construction greatly extends the repertoire of the recombineering toolbox and provides a simple, rapid and cost-effective method of constructing these highly complex vectors.

  5. Recombinant vectors construction for cellobiohydrolase encoding gene constitutive expression

    Directory of Open Access Journals (Sweden)

    Leontina GURGU

    2012-12-01

    Full Text Available Cellobiohydrolases (EC 3.2.1.91 are important exo enzymes involved in cellulose hydrolysis alongside endoglucanases (EC 3.2.1.4 and β-glucosidases (EC 3.2.1.21. Heterologous cellobiohydrolase gene expression under constitutive promoter control using Saccharomyces cerevisiae as host system is of great importance for a successful SSF process. From this point of view, the main objective of the work was to use Yeplac181 expression vector as a recipient for cellobiohdrolase - cbhB encoding gene expression under the control of the actin promoter, in Saccharomyces cerevisiae. Two hybridvectors, YEplac-Actp and YEplac-Actp-CbhB, were generated usingEscherichia coli XLI Blue for the cloning experiments. Constitutive cbhB gene expression was checked by proteine gel electrophoresis (SDS-PAGE after insertion of these constructs into Saccharomyces cerevisiae.

  6. Protection against myxomatosis and rabbit viral hemorrhagic disease with recombinant myxoma viruses expressing rabbit hemorrhagic disease virus capsid protein.

    Science.gov (United States)

    Bertagnoli, S; Gelfi, J; Le Gall, G; Boilletot, E; Vautherot, J F; Rasschaert, D; Laurent, S; Petit, F; Boucraut-Baralon, C; Milon, A

    1996-08-01

    Two myxoma virus-rabbit hemorrhagic disease virus (RHDV) recombinant viruses were constructed with the SG33 strain of myxoma virus to protect rabbits against myxomatosis and rabbit viral hemorrhagic disease. These recombinant viruses expressed the RHDV capsid protein (VP60). The recombinant protein, which is 60 kDa in size, was antigenic, as revealed by its reaction in immunoprecipitation with antibodies raised against RHDV. Both recombinant viruses induced high levels of RHDV- and myxoma virus-specific antibodies in rabbits after immunization. Inoculations by the intradermal route protected animals against virulent RHDV and myxoma virus challenges.

  7. Surface immobilization of hexa-histidine-tagged adeno-associated viral vectors for localized gene delivery.

    Science.gov (United States)

    Jang, J-H; Koerber, J T; Gujraty, K; Bethi, S R; Kane, R S; Schaffer, D V

    2010-11-01

    Adeno-associated viral (AAV) vectors, which are undergoing broad exploration in clinical trials, have significant promise for therapeutic gene delivery because of their safety and delivery efficiency. Gene delivery technologies capable of mediating localized gene expression may further enhance the potential of AAV in a variety of therapeutic applications by reducing spread outside a target region, which may thereby reduce off-target side effects. We have genetically engineered an AAV variant capable of binding to surfaces with high affinity through a hexa-histidine metal-binding interaction. This immobilized AAV vector system mediates high-efficiency delivery to cells that contact the surface and thus may have promise for localized gene delivery, which may aid numerous applications of AAV delivery to gene therapy.

  8. Adeno-associated viral vector transduction of human mesenchymal stem cells

    DEFF Research Database (Denmark)

    Stender, Stefan; Murphy, Mary; O'Brien, Tim

    2007-01-01

    Mesenchymal stem cells (MSCs) have received considerable attention in the emerging field of regenerative medicine. One aspect of MSC research focuses on genetically modifying the cells with the aim of enhancing their regenerative potential. Adeno-associated virus (AAV) holds promise as a vector...... in human MSCs and to assess whether AAV transduction affects MSC multipotentiality. The results indicated that human MSCs could indeed be transiently transduced in vitro by the AAV2 vector with efficiencies of up to 65%. The percentage of GFP-positive cells peaked at 4 days post-transduction and declined...... rapidly towards 0% after day 8. The level of transgene expression in the GFP-positive population increased 4-fold over a 10,000 fold viral dose increase. This dose-response contrasted with the 200-fold increase observed in similarly transduced 293-cells, indicating a relatively restricted transgene...

  9. Serological Assays Based on Recombinant Viral Proteins for the Diagnosis of Arenavirus Hemorrhagic Fevers

    Directory of Open Access Journals (Sweden)

    Masayuki Saijo

    2012-10-01

    Full Text Available The family Arenaviridae, genus Arenavirus, consists of two phylogenetically independent groups: Old World (OW and New World (NW complexes. The Lassa and Lujo viruses in the OW complex and the Guanarito, Junin, Machupo, Sabia, and Chapare viruses in the NW complex cause viral hemorrhagic fever (VHF in humans, leading to serious public health concerns. These viruses are also considered potential bioterrorism agents. Therefore, it is of great importance to detect these pathogens rapidly and specifically in order to minimize the risk and scale of arenavirus outbreaks. However, these arenaviruses are classified as BSL-4 pathogens, thus making it difficult to develop diagnostic techniques for these virus infections in institutes without BSL-4 facilities. To overcome these difficulties, antibody detection systems in the form of an enzyme-linked immunosorbent assay (ELISA and an indirect immunofluorescence assay were developed using recombinant nucleoproteins (rNPs derived from these viruses. Furthermore, several antigen-detection assays were developed. For example, novel monoclonal antibodies (mAbs to the rNPs of Lassa and Junin viruses were generated. Sandwich antigen-capture (Ag-capture ELISAs using these mAbs as capture antibodies were developed and confirmed to be sensitive and specific for detecting the respective arenavirus NPs. These rNP-based assays were proposed to be useful not only for an etiological diagnosis of VHFs, but also for seroepidemiological studies on VHFs. We recently developed arenavirus neutralization assays using vesicular stomatitis virus (VSV-based pseudotypes bearing arenavirus recombinant glycoproteins. The goal of this article is to review the recent advances in developing laboratory diagnostic assays based on recombinant viral proteins for the diagnosis of VHFs and epidemiological studies on the VHFs caused by arenaviruses.

  10. Serological assays based on recombinant viral proteins for the diagnosis of arenavirus hemorrhagic fevers.

    Science.gov (United States)

    Fukushi, Shuetsu; Tani, Hideki; Yoshikawa, Tomoki; Saijo, Masayuki; Morikawa, Shigeru

    2012-10-12

    The family Arenaviridae, genus Arenavirus, consists of two phylogenetically independent groups: Old World (OW) and New World (NW) complexes. The Lassa and Lujo viruses in the OW complex and the Guanarito, Junin, Machupo, Sabia, and Chapare viruses in the NW complex cause viral hemorrhagic fever (VHF) in humans, leading to serious public health concerns. These viruses are also considered potential bioterrorism agents. Therefore, it is of great importance to detect these pathogens rapidly and specifically in order to minimize the risk and scale of arenavirus outbreaks. However, these arenaviruses are classified as BSL-4 pathogens, thus making it difficult to develop diagnostic techniques for these virus infections in institutes without BSL-4 facilities. To overcome these difficulties, antibody detection systems in the form of an enzyme-linked immunosorbent assay (ELISA) and an indirect immunofluorescence assay were developed using recombinant nucleoproteins (rNPs) derived from these viruses. Furthermore, several antigen-detection assays were developed. For example, novel monoclonal antibodies (mAbs) to the rNPs of Lassa and Junin viruses were generated. Sandwich antigen-capture (Ag-capture) ELISAs using these mAbs as capture antibodies were developed and confirmed to be sensitive and specific for detecting the respective arenavirus NPs. These rNP-based assays were proposed to be useful not only for an etiological diagnosis of VHFs, but also for seroepidemiological studies on VHFs. We recently developed arenavirus neutralization assays using vesicular stomatitis virus (VSV)-based pseudotypes bearing arenavirus recombinant glycoproteins. The goal of this article is to review the recent advances in developing laboratory diagnostic assays based on recombinant viral proteins for the diagnosis of VHFs and epidemiological studies on the VHFs caused by arenaviruses.

  11. Viral vector vaccines protect cockatiels from inflammatory lesions after heterologous parrot bornavirus 2 challenge infection.

    Science.gov (United States)

    Runge, Solveig; Olbert, Marita; Herden, Christiane; Malberg, Sara; Römer-Oberdörfer, Angela; Staeheli, Peter; Rubbenstroth, Dennis

    2017-01-23

    Avian bornaviruses are causative agents of proventricular dilatation disease (PDD), a chronic neurologic and often fatal disorder of psittacines including endangered species. To date no causative therapy or immunoprophylaxis is available. Our previous work has shown that viral vector vaccines can delay the course of homologous bornavirus challenge infections but failed to protect against PDD when persistent infection was not prevented. The goal of this study was to refine our avian bornavirus vaccination and infection model to better represent natural bornavirus infections in order to achieve full protection against a heterologous challenge infection. We observed that parrot bornavirus 2 (PaBV-2) readily infected cockatiels (Nymphicus hollandicus) by combined intramuscular and subcutaneous injection with as little as 10(2.7)foci-forming units (ffu) per bird, whereas a 500-fold higher dose of the same virus administered via peroral and oculonasal route did not result in persistent infection. These results indicated that experimental bornavirus challenge infections with this virus should be performed via the parenteral route. Prime-boost vaccination of cockatiels with Newcastle disease virus (NDV) and modified vaccinia virus Ankara (MVA) vectors expressing the nucleoprotein and phosphoprotein genes of PaBV-4 substantially blocked bornavirus replication following parenteral challenge infection with 10(3.5)ffu of heterologous PaBV-2. Only two out of six vaccinated birds had very low viral levels detectable in a few organs. As a consequence, only one vaccinated bird developed mild PDD-associated microscopic lesions, while mock-vaccinated controls were not protected against PaBV-2 infection and inflammation. Our results demonstrate that NDV and MVA vector vaccines can protect against invasive heterologous bornavirus challenge infections and subsequent PDD. These vector vaccines represent a promising tool to combat avian bornaviruses in psittacine populations. Copyright

  12. Semliki Forest Virus: un vector viral con múltiples aplicaciones

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    Luis Felipe Henao

    2007-06-01

    Full Text Available Se han utilizado los alfavirus como vectores de expresión, entre estos se encuentra el Semliki Forest virus (SFV, que es un virus envuelto, el cual, además de replicarse en el citoplasma, tiene la propiedad de expresar por separado las proteínas estructurales de las no estructurales, permitiendo un mayor control de la expresión. Los vectores derivados del SFV pueden tener una gama amplia de aplicaciones. Se pueden obtener altos títulos virales para la expresión eficiente de proteínas en diferentes líneas celulares. Pueden infectar un espectro amplio de células de mamíferos, así como de tejidos. Son prometedores para ser usados en la terapia génica como vehículos para el envío de genes específicos in vivo o in vitro, tanto en la terapia contra el cáncer como en la neuronal, especialmente cuando sólo sea necesaria una expresión a corto plazo. Sus aplicaciones en la producción de vacunas profilácticas o terapéuticas, es otro aspecto estudiado; se ha demostrado la generación de respuestas inmunes importantes contra diferentes enfermedades virales y tumorales. El desarrollo de nuevos vectores no citopáticos, de otros regulados por temperatura, así como también de otros con replicación persistente; permitirán la prolongación de la expresión. Debido a estas nuevas ventajas y a las ya conocidas, gradualmente se podrían ampliar los usos para los vectores derivados del SFV a medida que se controlen sus efectos no deseados.

  13. Molecular Imaging of Biological Gene Delivery Vehicles for Targeted Cancer Therapy: Beyond Viral Vectors

    Energy Technology Data Exchange (ETDEWEB)

    Min, Jung Joon; Nguyen, Vu H. [Chonnam National University Medical School, Gwangju (Korea, Republic of); Gambhir, Sanjiv S. [Stanford University, California(United States)

    2010-04-15

    Cancer persists as one of the most devastating diseases in the world. Problems including metastasis and tumor resistance to chemotherapy and radiotherapy have seriously limited the therapeutic effects of present clinical treatments. To overcome these limitations, cancer gene therapy has been developed over the last two decades for a broad spectrum of applications, from gene replacement and knockdown to vaccination, each with different requirements for gene delivery. So far, a number of genes and delivery vectors have been investigated, and significant progress has been made with several gene therapy modalities in clinical trials. Viral vectors and synthetic liposomes have emerged as the vehicles of choice for many applications. However, both have limitations and risks that restrict gene therapy applications, including the complexity of production, limited packaging capacity, and unfavorable immunological features. While continuing to improve these vectors, it is important to investigate other options, particularly nonarrival biological agents such as bacteria, bacteriophages, and bacteria-like particles. Recently, many molecular imaging techniques for safe, repeated, and high-resolution in vivo imaging of gene expression have been employed to assess vector-mediated gene expression in living subjects. In this review, molecular imaging techniques for monitoring biological gene delivery vehicles are described, and the specific use of these methods at different steps is illustrated. Linking molecular imaging to gene therapy will eventually help to develop novel gene delivery vehicles for preclinical study and support the development of future human applications.

  14. CONSTRUCTION, EXPRESSION AND BIOLOGICAL ASSESSMENT OF BPI23-Fcγ 1 RECOMBINANT PROTEIN PROKARYOTIC EXPRESSION VECTOR

    Institute of Scientific and Technical Information of China (English)

    安云庆; 管远志; 柯岩; 杨贵贞

    2002-01-01

    Objective. To construct pBV-BPI600-Fcγ 1700 recombinant expression vector, to transform it into Escherichia coli DH5α , and to induce the expression of BPI23-Fcγ 1 anti-bacterial recombinant protein. Methods. Genes coding for BPI23 and Fcγ 1 were amplified by RT-PCR from mRNA extracted from HL-60 cell and normal human leukocytes; recombinant cloning vector and recombinant expression vector were then constructed. pBV-BPI600-Fcγ 1700 recombinant expression vector was transformed into the competent Escherichia coli DH5α and BPI23-Fcγ 1 recombinant protein was expressed by a temperature-induced method. Results. (1) Expected amplified products BPI600bp and Fcγ 1700bp were obtained by RT-PCR method. (2) pUC18-BPI180, pUC18-BPI420 and pUC18-Fcγ 1700 recombinant cloning vectors were successfully constructed, and sequences were identical with the reported ones. (3) pBV-BPI600-Fcγ 1700 recombinant expression vector was successfully constructed, and the enzyme digestion analysis showed an expected result. (4) The expression level of BPI23-Fcγ 1 recombinant protein accounted for 20% of total bacterial proteins. (5) The renatured BPI23-Fcγ 1 recombinant protein showed bacteriocidal activity and biological function of complement fixation, and opsonization. Conclusion. pBV-BPI600-Fcγ 1700 recombinant expression vector was successfully constructed, and BPI23-Fcγ 1 recombinant protein with double biological activity of BPI and IgGFc was expressed in Escherichia coli.

  15. CONSTRUCTION,EXPRESSION AND BIOLOGICAL ASSESSMENT OF BPI23—Fcγ1 RECOMBINANT PROTEIN PROKARYOTIC EXPRESSION VECTOR

    Institute of Scientific and Technical Information of China (English)

    安云庆; 管远志; 等

    2002-01-01

    Objective:To construct pBV-BPI600-Fcγ1700 recombinant expression vector,to transform it into Escherichia coli DH5α,and to induce the expression of BPI23-Fcγ1 anti-bacterial recombinant protein.Methods:Genes coding for BPI23 and Fcγ1 were amplified by RT-PCR from mRNA extracted from Hl-60 cell and normal human leukocytes;recombinant cloning vector and recombinant expression vector were then constructed.pBV-BPI600-Fcγ1700 recombinant expression vector was transformed into the competent Escherichia coli DH5α and BPI23-Fcγ1 recombinant protein was expressed by a temperature-induced method.Results:(1)Expected amplified products BPI600bp and Fcγ1700bp were obtained by RT-PCR method.(2)pUC18-BPI180,pUC18-BPI420 and pUC18-Fcγ1700 recombinant cloning vectors were successfully constructed, and sequences were identical with the reported ones.(3)pBV-BPI600-Fcγ1700 recombinant expression vector was successfully constructed,and the enzyme digestion analysis showed an expected result.(4)The expression level of BPI23-Fcγ1 recombinant protein accounted for 20% of total bacterial proteins.(5)The renatured BPI23-Fcγ1 recombinant protein showed bacteriocidal activity and biological function of complement fixation,and opsonization.Conclusion:pBV-BPI600-Fcγ1700 recombinant expression vector was successfully constructed,and BPI23-Fcγ1 recombinant protein with double biological activity of BPI and IgGFc was expressed in Escherichia coli.

  16. Strategies to generate high-titer, high-potency recombinant AAV3 serotype vectors

    Directory of Open Access Journals (Sweden)

    Chen Ling

    2016-01-01

    Full Text Available Although recombinant adeno-associated virus serotype 3 (AAV3 vectors were largely ignored previously, owing to their poor transduction efficiency in most cells and tissues examined, our initial observation of the selective tropism of AAV3 serotype vectors for human liver cancer cell lines and primary human hepatocytes has led to renewed interest in this serotype. AAV3 vectors and their variants have recently proven to be extremely efficient in targeting human and nonhuman primate hepatocytes in vitro as well as in vivo. In the present studies, we wished to evaluate the relative contributions of the cis-acting inverted terminal repeats (ITRs from AAV3 (ITR3, as well as the trans-acting Rep proteins from AAV3 (Rep3 in the AAV3 vector production and transduction. To this end, we utilized two helper plasmids: pAAVr2c3, which carries rep2 and cap3 genes, and pAAVr3c3, which carries rep3 and cap3 genes. The combined use of AAV3 ITRs, AAV3 Rep proteins, and AAV3 capsids led to the production of recombinant vectors, AAV3-Rep3/ITR3, with up to approximately two to fourfold higher titers than AAV3-Rep2/ITR2 vectors produced using AAV2 ITRs, AAV2 Rep proteins, and AAV3 capsids. We also observed that the transduction efficiency of Rep3/ITR3 AAV3 vectors was approximately fourfold higher than that of Rep2/ITR2 AAV3 vectors in human hepatocellular carcinoma cell lines in vitro. The transduction efficiency of Rep3/ITR3 vectors was increased by ∼10-fold, when AAV3 capsids containing mutations in two surface-exposed residues (serine 663 and threonine 492 were used to generate a S663V+T492V double-mutant AAV3 vector. The Rep3/ITR3 AAV3 vectors also transduced human liver tumors in vivo approximately twofold more efficiently than those generated with Rep2/ITR2. Our data suggest that the transduction efficiency of AAV3 vectors can be significantly improved both using homologous Rep proteins and ITRs as well as by capsid optimization. Thus, the combined use of

  17. 昆津病毒复制子——一种新型病毒载体%Kunjin virus replicon——a novel viral Vector

    Institute of Scientific and Technical Information of China (English)

    李世华; 李晓峰; 秦鄂德; 秦成峰

    2011-01-01

    Viral replicon is a kind of self-replicating viral RNA sourced from viral genome, which contains viral non-structural genes that are critical for viral genome replication with structural proteins deleted or replaced by foreign genes. Kunjin virus is a member of the Flavivirida family, Flavivirus genus, and Kunjin virus replicon is the first and the clearly defined flavivirus replicon. Kunjun virus replicon has been regarded as an excellent viral vector on account of its high expression, lower cytotoxicity and genetic stability. These unique characteristics of kunjin virus replicons make them suitable for the study of viral genome replication, recombinant proteins production, vaccine development and gene therapy. In this article, recent progress in the development, properties and applications of kunjin virus replicon system was briefly reviewed.%病毒复制子(Replicon)是指来源于病毒基因组的能够自主复制的RNA分子,保留了病毒非结构蛋白基因,而结构蛋白基因缺失或由外源基因替代.昆津病毒(Kunjun virus)为黄病毒科黄病毒属成员,其复制子具有表达效率高、细胞毒性低、遗传稳定等特点,在病毒基因组复制调控机制、外源蛋白表达、新型疫苗和基因治疗等领域得到了广泛应用.以下就昆津病毒复制子系统的构建,特性及应用方面的研究进展作一综述.

  18. Murine leukemia virus-derived retroviral vector has differential integration patterns in human cell lines used to produce recombinant factor VIII

    Directory of Open Access Journals (Sweden)

    Marcela Cristina Correa de Freitas

    2014-06-01

    Full Text Available OBJECTIVE: Nowadays recombinant factor VIII is produced in murine cells including in Chinese hamster ovary (CHO and baby hamster kidney cells (BHK. Previous studies, using the murine leukemia virus-derived retroviral vector pMFG-FVIII-P140K, modified two recombinant human cell lines, HepG2 and Hek293 to produce recombinant factor VIII. In order to characterize these cells, the present study aimed to analyze the integration pattern of retroviral vector pMFG-FVIII-P140K.METHODS: This study used ligation-mediated polymerase chain reaction to locate the site of viral vector integration by sequencing polymerase chain reaction products. The sequences were compared to genomic databases to characterize respective clones.RESULTS: The retroviral vector presented different and non-random profiles of integration between cells lines. A preference of integration for chromosomes 19, 17 and 11 was observed for HepG2FVIIIdB/P140K and chromosome 9 for Hek293FVIIIdB/P140K. In genomic regions such as CpG islands and transcription factor binding sites, there was no difference in the integration profiles for both cell lines. Integration in intronic regions of encoding protein genes (RefSeq genes was also observed in both cell lines. Twenty percent of integrations occurred at fragile sites in the genome of the HepG2 cell line and 17% in Hek293.CONCLUSION: The results suggest that the cell type can affect the profile of chromosomal integration of the retroviral vector used; these differences may interfere in the level of expression of recombinant proteins.

  19. The use of an adeno-associated viral vector for efficient bicistronic expression of two genes in the central nervous system.

    Science.gov (United States)

    Hutson, Thomas Haynes; Kathe, Claudia; Menezes, Sean Christopher; Rooney, Marie-Claire; Bueler, Hansruedi; Moon, Lawrence David Falcon

    2014-01-01

    Recombinant adeno-associated viral (AAV) vectors are one of the most promising therapeutic delivery systems for gene therapy to the central nervous system (CNS). Preclinical testing of novel gene therapies requires the careful design and production of AAV vectors and their successful application in a model of CNS injury. One major limitation of AAV vectors is their limited packaging capacity (genes (e.g., from two promoters) difficult. An internal ribosomal entry site has been used to express two genes: However, the second transgene is often expressed at lower levels than the first. In addition to this, achieving high levels of transduction in the CNS can be challenging. In this chapter we describe the cloning of a bicistronic AAV vector that uses the foot-and-mouth disease virus 2A sequence to efficiently express two genes from a single promoter. Bicistronic expression of a therapeutic gene and a reporter gene is desirable so that the axons from transduced neurons can be tracked and, after CNS injury, the amount of axonal sprouting or regeneration quantified. We go on to describe how to perform a pyramidotomy model of CNS injury and the injection of AAV vectors into the sensorimotor cortex to provide efficient transduction and bicistronic gene expression in cortical neurons such that transduced axons are detectable in the dorsal columns of the spinal cord.

  20. Rainbow trout surviving infections of viral haemorrhagic septicemia virus (VHSV) show lasting antibodies to recombinant G protein fragments

    DEFF Research Database (Denmark)

    Encinas, P.; Gomez-Casado, E.; Grandes, Fregeneda

    2011-01-01

    Rainbow trout antibodies (Abs) binding to recombinant fragments (frgs) derived from the protein G of the viral haemorrhagic septicemia virus (VHSV)-07.71 strain, could be detected by ELISA (frg-ELISA) in sera from trout surviving laboratory-controlled infections. Abs were detected not only by using...... infections. The viral frgs approach might also be used with other fish species and/or viruses....

  1. Recombinant covalently closed circular hepatitis B virus DNA induces prolonged viral persistence in immunocompetent mice.

    Science.gov (United States)

    Qi, Zhihua; Li, Gaiyun; Hu, Hao; Yang, Chunhui; Zhang, Xiaoming; Leng, Qibin; Xie, Youhua; Yu, Demin; Zhang, Xinxin; Gao, Yueqiu; Lan, Ke; Deng, Qiang

    2014-07-01

    It remains crucial to develop a laboratory model for studying hepatitis B virus (HBV) chronic infection. We hereby produced a recombinant covalently closed circular DNA (rcccDNA) in view of the key role of cccDNA in HBV persistence. A loxP-chimeric intron was engineered into a monomeric HBV genome in a precursor plasmid (prcccDNA), which was excised using Cre/loxP-mediated DNA recombination into a 3.3-kb rcccDNA in the nuclei of hepatocytes. The chimeric intron was spliced from RNA transcripts without interrupting the HBV life cycle. In cultured hepatoma cells, cotransfection of prcccDNA and pCMV-Cre (encoding Cre recombinase) resulted in accumulation of nuclear rcccDNA that was heat stable and epigenetically organized as a minichromosome. A mouse model of HBV infection was developed by hydrodynamic injection of prcccDNA. In the presence of Cre recombinase, rcccDNA was induced in the mouse liver with effective viral replication and expression, triggering a compromised T-cell response against HBV. Significant T-cell hyporesponsiveness occurred in mice receiving 4 μg prcccDNA, resulting in prolonged HBV antigenemia for up to 9 weeks. Persistent liver injury was observed as elevated alanine transaminase activity in serum and sustained inflammatory infiltration in the liver. Although a T-cell dysfunction was induced similarly, mice injected with a plasmid containing a linear HBV replicon showed rapid viral clearance within 2 weeks. Collectively, our study provides an innovative approach for producing a cccDNA surrogate that established HBV persistence in immunocompetent mice. It also represents a useful model system in vitro and in vivo for evaluating antiviral treatments against HBV cccDNA. Importance: (i) Unlike plasmids that contain a linear HBV replicon, rcccDNA established HBV persistence with sustained liver injury in immunocompetent mice. This method could be a prototype for developing a mouse model of chronic HBV infection. (ii) An exogenous intron was

  2. The development of an efficient multipurpose bean pod mottle virus viral vector set for foreign gene expression and RNA silencing.

    Science.gov (United States)

    Zhang, Chunquan; Bradshaw, Jeffrey D; Whitham, Steven A; Hill, John H

    2010-05-01

    Plant viral vectors are valuable tools for heterologous gene expression, and because of virus-induced gene silencing (VIGS), they also have important applications as reverse genetics tools for gene function studies. Viral vectors are especially useful for plants such as soybean (Glycine max) that are recalcitrant to transformation. Previously, two generations of bean pod mottle virus (BPMV; genus Comovirus) vectors have been developed for overexpressing and silencing genes in soybean. However, the design of the previous vectors imposes constraints that limit their utility. For example, VIGS target sequences must be expressed as fusion proteins in the same reading frame as the viral polyprotein. This requirement limits the design of VIGS target sequences to open reading frames. Furthermore, expression of multiple genes or simultaneous silencing of one gene and expression of another was not possible. To overcome these and other issues, a new BPMV-based vector system was developed to facilitate a variety of applications for gene function studies in soybean as well as in common bean (Phaseolus vulgaris). These vectors are designed for simultaneous expression of multiple foreign genes, insertion of noncoding/antisense sequences, and simultaneous expression and silencing. The simultaneous expression of green fluorescent protein and silencing of phytoene desaturase shows that marker gene-assisted silencing is feasible. These results demonstrate the utility of this BPMV vector set for a wide range of applications in soybean and common bean, and they have implications for improvement of other plant virus-based vector systems.

  3. Establishment of a Bovine Herpesvirus 4 based vector expressing a secreted form of the Bovine Viral Diarrhoea Virus structural glycoprotein E2 for immunization purposes

    Directory of Open Access Journals (Sweden)

    Donofrio Gaetano

    2007-10-01

    Full Text Available Abstract Background The biological characteristics of BoHV-4 make it a good candidate as a gene delivery vector for vaccination purposes. These characteristics include little or no pathogenicity, unlikely oncogenicity, the capability to accommodate large amounts of foreign genetic material, the ability to infect several cell types from different animal species, and the ability to maintain transgene expression in both undifferentiated and differentiated cells. Results A recombinant bovine herpesvirus 4 (BoHV-4CMV-IgKE2-14ΔTK expressing an enhanced secreted form of the bovine viral diarrhea virus (BVDV structural glycoprotein E2 (gE2-14, obtained by the removal of the putative transmembrane domain and addition of a 14 amino acids peptide at its carboxyl terminal and an immunoglobulin K signal peptide to the amino terminal, was successfully constructed using a Recombineering (recombination -mediated genetic engineering approach on BoHV-4 cloned as bacterial artificial chromosome. The galactokinase – based recombineering system was modified by the introduction of a kanamycin expression cassette and a kanamycin selection step that allowed a significant reduction of the untargeted background clones. BoHV-4CMV-IgKE2-14ΔTK infected cell lines highly expressed gE2-14, which maintained native antigenic properties in a serum neutralization inhibition test. When rabbits and sheep were immunized with BoHV-4CMV-IgKE2-14ΔTK, high levels of serum neutralized antibodies against BVDV were generated. Conclusion This work highlights the engineerization of BoHV-4 genome as a vector for vaccine purposes and may provide the basis for BVDV vaccination exploiting the BoHV-4- based vector that delivers an improved secreted version of the BVDV structural glycoprotein E2.

  4. Efficient generation of rat induced pluripotent stem cells using a non-viral inducible vector.

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    Claudia Merkl

    Full Text Available Current methods of generating rat induced pluripotent stem cells are based on viral transduction of pluripotency inducing genes (Oct4, Sox2, c-myc and Klf4 into somatic cells. These activate endogenous pluripotency genes and reprogram the identity of the cell to an undifferentiated state. Epigenetic silencing of exogenous genes has to occur to allow normal iPS cell differentiation. To gain more control over the expression of exogenous reprogramming factors, we used a novel doxycycline-inducible plasmid vector encoding Oct4, Sox2, c-Myc and Klf4. To ensure efficient and controlled generation of iPS cells by plasmid transfection we equipped the reprogramming vector with a bacteriophage φC31 attB site and used a φC31 integrase expression vector to enhance vector integration. A series of doxycycline-independent rat iPS cell lines were established. These were characterized by immunocytochemical detection of Oct4, SSEA1 and SSEA4, alkaline phosphatase staining, methylation analysis of the endogenous Oct4 promoter and RT-PCR analysis of endogenous rat pluripotency genes. We also determined the number of vector integrations and the extent to which reprogramming factor gene expression was controlled. Protocols were developed to generate embryoid bodies and rat iPS cells demonstrated as pluripotent by generating derivatives of all three embryonic germ layers in vitro, and teratoma formation in vivo. All data suggest that our rat iPS cells, generated by plasmid based reprogramming, are similar to rat ES cells. Methods of DNA transfection, protein transduction and feeder-free monolayer culture of rat iPS cells were established to enable future applications.

  5. Cooler temperatures destabilize RNA interference and increase susceptibility of disease vector mosquitoes to viral infection.

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    Zach N Adelman

    Full Text Available BACKGROUND: The impact of global climate change on the transmission dynamics of infectious diseases is the subject of extensive debate. The transmission of mosquito-borne viral diseases is particularly complex, with climatic variables directly affecting many parameters associated with the prevalence of disease vectors. While evidence shows that warmer temperatures often decrease the extrinsic incubation period of an arthropod-borne virus (arbovirus, exposure to cooler temperatures often predisposes disease vector mosquitoes to higher infection rates. RNA interference (RNAi pathways are essential to antiviral immunity in the mosquito; however, few experiments have explored the effects of temperature on the RNAi machinery. METHODOLOGY/PRINCIPAL FINDINGS: We utilized transgenic "sensor" strains of Aedes aegypti to examine the role of temperature on RNA silencing. These "sensor" strains express EGFP only when RNAi is inhibited; for example, after knockdown of the effector proteins Dicer-2 (DCR-2 or Argonaute-2 (AGO-2. We observed an increase in EGFP expression in transgenic sensor mosquitoes reared at 18°C as compared with 28°C. Changes in expression were dependent on the presence of an inverted repeat with homology to a portion of the EGFP sequence, as transgenic strains lacking this sequence, the double stranded RNA (dsRNA trigger for RNAi, showed no change in EGFP expression when reared at 18°C. Sequencing small RNAs in sensor mosquitoes reared at low temperature revealed normal processing of dsRNA substrates, suggesting the observed deficiency in RNAi occurs downstream of DCR-2. Rearing at cooler temperatures also predisposed mosquitoes to higher levels of infection with both chikungunya and yellow fever viruses. CONCLUSIONS/SIGNIFICANCE: This data suggest that microclimates, such as those present in mosquito breeding sites, as well as more general climactic variables may influence the dynamics of mosquito-borne viral diseases by affecting

  6. Viral vector-mediated selective and reversible blockade of the pathway for visual orienting in mice

    Directory of Open Access Journals (Sweden)

    Tadashi eIsa

    2013-10-01

    Full Text Available Recently, by using a combination of two viral vectors, we developed a technique for pathway-selective and reversible synaptic transmission blockade, and successfully induced a behavioral deficit of dexterous hand movements in macaque monkeys by affecting a population of spinal interneurons. To explore the capacity of this technique to work in other pathways and species, and to obtain fundamental methodological information, we tried to block the crossed tecto-reticular pathway, which is known to control orienting responses to visual targets, in mice. A neuron-specific retrograde gene transfer vector with the gene encoding enhanced tetanus neurotoxin (eTeNT tagged with enhanced green fluorescent protein (EGFP under the control of a tetracycline responsive element was injected into the left medial pontine reticular formation. 7–17 days later, an adeno-associated viral vector with a highly efficient Tet-ON sequence, rtTAV16, was injected into the right superior colliculus. 5–9 weeks later, the daily administration of doxycycline (Dox was initiated. Visual orienting responses toward the left side were impaired 1 - 4 days after Dox administration. Anti-GFP immunohistochemistry revealed that a number of neurons in the intermediate and deep layers of the right superior colliculus were positively stained, indicating eTeNT expression. After the termination of Dox administration, the anti-GFP staining returned to the baseline level within 28 days. A second round of Dox administration, starting from 28 days after the termination of the first Dox administration, resulted in the reappearance of the behavioral impairment. These findings showed that pathway-selective and reversible blockade of synaptic transmission causes behavioral effects also in rodents, and that the crossed tecto-reticular pathway surely controls visual orienting behaviors.

  7. Transgene optimization, immunogenicity and in vitro efficacy of viral vectored vaccines expressing two alleles of Plasmodium falciparum AMA1.

    Directory of Open Access Journals (Sweden)

    Sumi Biswas

    Full Text Available BACKGROUND: Apical membrane antigen 1 (AMA1 is a leading candidate vaccine antigen against blood-stage malaria, although to date numerous clinical trials using mainly protein-in-adjuvant vaccines have shown limited success. Here we describe the pre-clinical development and optimization of recombinant human and simian adenoviral (AdHu5 and ChAd63 and orthopoxviral (MVA vectors encoding transgene inserts for Plasmodium falciparum AMA1 (PfAMA1. METHODOLOGY/PRINCIPAL FINDINGS: AdHu5-MVA prime-boost vaccination in mice and rabbits using these vectors encoding the 3D7 allele of PfAMA1 induced cellular immune responses as well as high-titer antibodies that showed growth inhibitory activity (GIA against the homologous but not heterologous parasite strains. In an effort to overcome the issues of PfAMA1 antigenic polymorphism and pre-existing immunity to AdHu5, a simian adenoviral (ChAd63 vector and MVA encoding two alleles of PfAMA1 were developed. This antigen, composed of the 3D7 and FVO alleles of PfAMA1 fused in tandem and with expression driven by a single promoter, was optimized for antigen secretion and transmembrane expression. These bi-allelic PfAMA1 vaccines, when administered to mice and rabbits, demonstrated comparable immunogenicity to the mono-allelic vaccines and purified serum IgG now showed GIA against the two divergent strains of P. falciparum encoded in the vaccine. CD8(+ and CD4(+ T cell responses against epitopes that were both common and unique to the two alleles of PfAMA1 were also measured in mice. CONCLUSIONS/SIGNIFICANCE: Optimized transgene inserts encoding two divergent alleles of the same antigen can be successfully inserted into adeno- and pox-viral vaccine vectors. Adenovirus-MVA immunization leads to the induction of T cell responses common to both alleles, as well as functional antibody responses that are effective against both of the encoded strains of P. falciparum in vitro. These data support the further clinical

  8. Construction and characterization of a recombinant human adenovirus vector expressing bone morphogenetic protein 2

    OpenAIRE

    Zhang, Zheng; WANG, GUOXIAN; Li, Chen; Liu, Danping

    2013-01-01

    The aim of this study was to construct and characterize a novel recombinant human adenovirus vector expressing bone morphogenetic protein 2 (BMP2) and green fluorescent protein (GFP). The BMP2 gene in the plasmid pcDNA3-BMP2 was sequenced and the restriction enzyme recognition sites were analyzed. Following mutagenesis using polymerase chain reaction (PCR), the gene sequence after the translation termination codon was removed and new restriction sites were added. The mutated BMP2 gene (BMP2+ ...

  9. THE ROLE OF RECOMBINANT Rb GENE ADENOVIRUS VECTOR IN THE GROWTH OF LUNG ADENOCARCINOMA CELLS

    Institute of Scientific and Technical Information of China (English)

    Li Jian; Jiang Lei; Xia Yongjing; Li Hongxia; Hu Yajun; Hu Shixue; Xu Hongji

    1998-01-01

    Objective:To study the role of the most extensively studied tumor suppressor gene, retinoblastoma (Rb) gene,on the growth of lung adenocarcinoma cell line GLC-82 and explore a gene therapy approach for lung adenocarcinoma. Methods: The recombinant Rb gene adenovirus vector was constructed, the control virus which carries LacZ gene was producted by the same method. Infection effects were detected by biochemical staining of β-gal and immunohistochemical analysis of Rb protein. The Rb cDNA of infected cells were determined by PCR. The cell growth rate and cell cycle were observed by cell-counting and flow cytometry. Results: The constructed recombinant adenovirus vector could infect effectively the cells with high level expression of Rb cDNA and Rb protein. The transfection of wild-type Rb gene could suppress GLC-82 cell proliferation and decrease the cellular DNA synthesis. Conclusions: These results showed the possibility of using recombinant Rb gene adenovirus vector in the gene therapy of cancer to inhibit the growth of cancer.

  10. Regulation of U6 Promoter Activity by Transcriptional Interference in Viral Vector-Based RNAi

    Institute of Scientific and Technical Information of China (English)

    Linghu Nie; Meghna Das Thakur; Yumei Wang; Qin Su; Yongliang Zhao; Yunfeng Feng

    2010-01-01

    The direct negative impact of the transcriptional activity of one component on the second one in c/s is referred to as transcriptional interference (TI).U6 is a type Ⅲ RNA polymerase Ⅲ promoter commonly used for driving small hairpin RNA (shRNA) expression in vector-based RNAi.In the design and construction of viral vectors,multiple transcription units may be arranged in close proximity in a space-limited vector.Determining if U6 promoter activity can be affected by TI is critical for the expression of target shRNA in gene therapy or loss-of-function studies.In this research,we designed and implemented a modified retroviral system where shRNA and exogenous gene expressions were driven by two independent transcriptional units.We arranged U6 promoter driving.shRNA expression and UbiC promoter in two promoter arrangements.In primary macrophages,we found U6 promoter activity was inhibited by UbiC promoter when in the divergent arrangement but not in tandem.In contrast,PKG promoter had no such negative impact.Instead of enhancing U6 promoter activity,CMV enhancer had significant negative impact on U6 promoter activity in the presence of UbiC promoter.Our results indicate that U6 promoter activity can be affected by TI in a proximal promoter-specific and arrangement-dependent manner.

  11. Magnetically enhanced adeno-associated viral vector delivery for human neural stem cell infection.

    Science.gov (United States)

    Kim, Eunmi; Oh, Ji-Seon; Ahn, Ik-Sung; Park, Kook In; Jang, Jae-Hyung

    2011-11-01

    Gene therapy technology is a powerful tool to elucidate the molecular cues that precisely regulate stem cell fates, but developing safe vehicles or mechanisms that are capable of delivering genes to stem cells with high efficiency remains a challenge. In this study, we developed a magnetically guided adeno-associated virus (AAV) delivery system for gene delivery to human neural stem cells (hNSCs). Magnetically guided AAV delivery resulted in rapid accumulation of vectors on target cells followed by forced penetration of the vectors across the plasma membrane, ultimately leading to fast and efficient cellular transduction. To combine AAV vectors with the magnetically guided delivery, AAV was genetically modified to display hexa-histidine (6xHis) on the physically exposed loop of the AAV2 capsid (6xHis AAV), which interacted with nickel ions chelated on NTA-biotin conjugated to streptavidin-coated superparamagnetic iron oxide nanoparticles (NiStNPs). NiStNP-mediated 6xHis AAV delivery under magnetic fields led to significantly enhanced cellular transduction in a non-permissive cell type (i.e., hNSCs). In addition, this delivery method reduced the viral exposure times required to induce a high level of transduction by as much as to 2-10 min of hNSC infection, thus demonstrating the great potential of magnetically guided AAV delivery for numerous gene therapy and stem cell applications.

  12. Chikungunya viral fitness measures within the vector and subsequent transmission potential.

    Directory of Open Access Journals (Sweden)

    Rebecca C Christofferson

    Full Text Available Given the recent emergence of chikungunya in the Americas, the accuracy of forecasting and prediction of chikungunya transmission potential in the U.S. requires urgent assessment. The La Reunion-associated sub-lineage of chikungunya (with a valine substitution in the envelope protein was shown to increase viral fitness in the secondary vector, Ae. albopictus. Subsequently, a majority of experimental and modeling efforts focused on this combination of a sub-lineage of the East-Central-South African genotype (ECSA-V-Ae. albopictus, despite the Asian genotype being the etiologic agent of recent chikungunya outbreaks world-wide. We explore a collection of data to investigate relative transmission efficiencies of the three major genotypes/sub-lineages of chikungunya and found difference in the extrinsic incubation periods to be largely overstated. However, there is strong evidence supporting the role of Ae. albopictus in the expansion of chikungunya that our R0 calculations cannot attribute to fitness increases in one vector over another. This suggests other ecological factors associated with the Ae. albopictus-ECSA-V cycle may drive transmission intensity differences. With the apparent bias in literature, however, we are less prepared to evaluate transmission where Ae. aegypti plays a significant role. Holistic investigations of CHIKV transmission cycle(s will allow for more complete assessment of transmission risk in areas affected by either or both competent vectors.

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

    Science.gov (United States)

    Wang, Dan; Zhong, Li; Nahid, M Abu; Gao, Guangping

    2014-03-01

    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. 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. 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.

  14. Recombinant vesicular stomatitis virus vaccine vectors expressing filovirus glycoproteins lack neurovirulence in nonhuman primates.

    Directory of Open Access Journals (Sweden)

    Chad E Mire

    Full Text Available The filoviruses, Marburg virus and Ebola virus, cause severe hemorrhagic fever with high mortality in humans and nonhuman primates. Among the most promising filovirus vaccines under development is a system based on recombinant vesicular stomatitis virus (rVSV that expresses an individual filovirus glycoprotein (GP in place of the VSV glycoprotein (G. The main concern with all replication-competent vaccines, including the rVSV filovirus GP vectors, is their safety. To address this concern, we performed a neurovirulence study using 21 cynomolgus macaques where the vaccines were administered intrathalamically. Seven animals received a rVSV vector expressing the Zaire ebolavirus (ZEBOV GP; seven animals received a rVSV vector expressing the Lake Victoria marburgvirus (MARV GP; three animals received rVSV-wild type (wt vector, and four animals received vehicle control. Two of three animals given rVSV-wt showed severe neurological symptoms whereas animals receiving vehicle control, rVSV-ZEBOV-GP, or rVSV-MARV-GP did not develop these symptoms. Histological analysis revealed major lesions in neural tissues of all three rVSV-wt animals; however, no significant lesions were observed in any animals from the filovirus vaccine or vehicle control groups. These data strongly suggest that rVSV filovirus GP vaccine vectors lack the neurovirulence properties associated with the rVSV-wt parent vector and support their further development as a vaccine platform for human use.

  15. Construction of Rat Calcineurin A α cDNA Recombinant Adenovirus Vector and Its Identification

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Rat calcineurin (CaN) A α isoform (Ppp3ca) cDNA recombinant adenovirus vector was constructed in order to explore the effect of CaN on the myocardium apoptosis induced by ischemiareperfusion injury. Total RNA was isolated from the heart of the adult Wistar rat, and Ppp3ca CDS segment of approximate 1.59 kb size was amplified by reverse transcriptional PCR method. Ppp3ca cDNA segment was cloned into pMD18-T Simple vector for sequencing, and the right clone was named T-Ppp3ca. Ppp3ca cDNA segment obtained from T-Ppp3ca was ligated with pShuttle2-IRES-EGFP to construct a recombinant plasmid pShuttle2-Ppp3ca-IRES-EGFP. Ppp3ca-IRES-EG-FP expression cassette containing CMV, Ppp3ca-IRES-EGFP and SV40 polyA DNA fragment (3.97 kb) obtained from pShuttle2-Ppp3ca-IRES-EGFP was connected with pAdeno-X backbone sequence to construct a recombinant plasmid pAdeno-Ppp3ca. After being identified by PCR and enzyme digestion, recombinant plasmid pAdeno-Ppp3ca was packaged in HEK293 cells. Supernatant of adenovirus from HEK293 cells was collected after a visible cytopathic effect (CPE) appeared.The DNA of the recombinant adenovirus was extracted with the standard method. The presence of the recombinant adenovirus was verified by PCR. The results showed that sequencing results veri fied that the PCR product of Ppp3ca gene was identical to GenBank. Agarose electrophoresis showed the bands of recombined plasmid pAdeno-Ppp3ca and the recombinant adenovirus identified by enzyme digestion and PCR were in the right range corresponding with expectation. It was concluded that the recombinant adenovirus carrying rat calcineurin A α (Ppp3ca) cDNA as well as a report gene-enhancer green fluorescent protein gene was successfully constructed in this experiment.

  16. Recombination between Poliovirus and Coxsackie A Viruses of Species C: A Model of Viral Genetic Plasticity and Emergence

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    Francis Delpeyroux

    2011-08-01

    Full Text Available Genetic recombination in RNA viruses was discovered many years ago for poliovirus (PV, an enterovirus of the Picornaviridae family, and studied using PV or other picornaviruses as models. Recently, recombination was shown to be a general phenomenon between different types of enteroviruses of the same species. In particular, the interest for this mechanism of genetic plasticity was renewed with the emergence of pathogenic recombinant circulating vaccine-derived polioviruses (cVDPVs, which were implicated in poliomyelitis outbreaks in several regions of the world with insufficient vaccination coverage. Most of these cVDPVs had mosaic genomes constituted of mutated poliovaccine capsid sequences and part or all of the non-structural sequences from other human enteroviruses of species C (HEV-C, in particular coxsackie A viruses. A study in Madagascar showed that recombinant cVDPVs had been co-circulating in a small population of children with many different HEV-C types. This viral ecosystem showed a surprising and extensive biodiversity associated to several types and recombinant genotypes, indicating that intertypic genetic recombination was not only a mechanism of evolution for HEV-C, but an usual mode of genetic plasticity shaping viral diversity. Results suggested that recombination may be, in conjunction with mutations, implicated in the phenotypic diversity of enterovirus strains and in the emergence of new pathogenic strains. Nevertheless, little is known about the rules and mechanisms which govern genetic exchanges between HEV-C types, as well as about the importance of intertypic recombination in generating phenotypic variation. This review summarizes our current knowledge of the mechanisms of evolution of PV, in particular recombination events leading to the emergence of recombinant cVDPVs.

  17. Recombination between poliovirus and coxsackie A viruses of species C: a model of viral genetic plasticity and emergence.

    Science.gov (United States)

    Combelas, Nicolas; Holmblat, Barbara; Joffret, Marie-Line; Colbère-Garapin, Florence; Delpeyroux, Francis

    2011-08-01

    Genetic recombination in RNA viruses was discovered many years ago for poliovirus (PV), an enterovirus of the Picornaviridae family, and studied using PV or other picornaviruses as models. Recently, recombination was shown to be a general phenomenon between different types of enteroviruses of the same species. In particular, the interest for this mechanism of genetic plasticity was renewed with the emergence of pathogenic recombinant circulating vaccine-derived polioviruses (cVDPVs), which were implicated in poliomyelitis outbreaks in several regions of the world with insufficient vaccination coverage. Most of these cVDPVs had mosaic genomes constituted of mutated poliovaccine capsid sequences and part or all of the non-structural sequences from other human enteroviruses of species C (HEV-C), in particular coxsackie A viruses. A study in Madagascar showed that recombinant cVDPVs had been co-circulating in a small population of children with many different HEV-C types. This viral ecosystem showed a surprising and extensive biodiversity associated to several types and recombinant genotypes, indicating that intertypic genetic recombination was not only a mechanism of evolution for HEV-C, but an usual mode of genetic plasticity shaping viral diversity. Results suggested that recombination may be, in conjunction with mutations, implicated in the phenotypic diversity of enterovirus strains and in the emergence of new pathogenic strains. Nevertheless, little is known about the rules and mechanisms which govern genetic exchanges between HEV-C types, as well as about the importance of intertypic recombination in generating phenotypic variation. This review summarizes our current knowledge of the mechanisms of evolution of PV, in particular recombination events leading to the emergence of recombinant cVDPVs.

  18. Measurement of recombination frequencies between two homologous DNA segments embedded in a YAC vector.

    Science.gov (United States)

    Yasui, H; Kurosawa, Y

    1993-07-15

    We measured the frequencies of recombination in a yeast host between two homologous segments of DNA that had been inserted with the same polarity in a yeast artificial chromosome (YAC) vector. Three kinds of YAC clones were constructed in which the gene encoding neomycin(Nm) resistance was sandwiched between two homologous segments of DNA, such as the IS3 elements of Escherichia coli or human Alu sequences. Frequencies of homologous recombination in yeast were measured in terms of loss of resistance to Nm. In the case of IS3 fragments, homologous recombination between them did occur at a relatively high frequency (5 x 10(-4). In contrast, recombination between two Alu sequences did not occur at a detectable level during a 30-day incubation. Thus, the frequency was less than 10(-5). These results indicate that the Alu sequences do not sufficiently promote the frequency of recombination between two homologous fragments in yeast as to induce rearrangements of DNA in a substantial fraction of YAC clones in libraries.

  19. Heterologous viral expression systems in fosmid vectors increase the functional analysis potential of metagenomic libraries.

    Science.gov (United States)

    Terrón-González, L; Medina, C; Limón-Mortés, M C; Santero, E

    2013-01-01

    The extraordinary potential of metagenomic functional analyses to identify activities of interest present in uncultured microorganisms has been limited by reduced gene expression in surrogate hosts. We have developed vectors and specialized E. coli strains as improved metagenomic DNA heterologous expression systems, taking advantage of viral components that prevent transcription termination at metagenomic terminators. One of the systems uses the phage T7 RNA-polymerase to drive metagenomic gene expression, while the other approach uses the lambda phage transcription anti-termination protein N to limit transcription termination. A metagenomic library was constructed and functionally screened to identify genes conferring carbenicillin resistance to E. coli. The use of these enhanced expression systems resulted in a 6-fold increase in the frequency of carbenicillin resistant clones. Subcloning and sequence analysis showed that, besides β-lactamases, efflux pumps are not only able contribute to carbenicillin resistance but may in fact be sufficient by themselves to convey carbenicillin resistance.

  20. Activities of wildtype and mutant p53 in suppression of homologous recombination as measured by a retroviral vector system

    Energy Technology Data Exchange (ETDEWEB)

    Lu Xiongbin; Lozano, Guillermina; Donehower, Lawrence A

    2003-01-28

    DNA repair of double strand breaks, interstrand DNA cross-links, and other types of DNA damage utilizes the processes of homologous recombination and non-homologous end joining to repair the damage. Aberrant homologous recombination is likely to be responsible for a significant fraction of chromosomal deletions, duplications, and translocations that are observed in cancer cells. To facilitate measurement of homologous recombination frequencies in normal cells, mutant cells, and cancer cells, we have developed a high titer retroviral vector containing tandem repeats of mutant versions of a GFP-Zeocin resistance fusion gene and an intact neomycin resistance marker. Recombination between the tandem repeats regenerates a functional GFP-Zeo{sup R} marker that can be easily scored. This retroviral vector was used to assess homologous recombination frequencies in human cancer cells and rodent fibroblasts with differing dosages of wild type or mutant p53. Absence of wild type p53 stimulated spontaneous and ionizing radiation-induced homologous recombination, confirming previous studies. Moreover, p53{sup +/-} mouse fibroblasts show elevated levels of homologous recombination compared to their p53{sup +/+} counterparts following retroviral vector infection, indicating that p53 is haploinsufficient for suppression of homologous recombination. Transfection of vector-containing p53 null Saos-2 cells with various human cancer-associated p53 mutants revealed that these altered p53 proteins retain some recombination suppression function despite being totally inactive for transcriptional transactivation. The retroviral vector utilized in these studies may be useful in performing recombination assays on a wide array of cell types, including those not readily transfected by normal vectors.

  1. Activities of wildtype and mutant p53 in suppression of homologous recombination as measured by a retroviral vector system.

    Science.gov (United States)

    Lu, Xiongbin; Lozano, Guillermina; Donehower, Lawrence A

    2003-01-28

    DNA repair of double strand breaks, interstrand DNA cross-links, and other types of DNA damage utilizes the processes of homologous recombination and non-homologous end joining to repair the damage. Aberrant homologous recombination is likely to be responsible for a significant fraction of chromosomal deletions, duplications, and translocations that are observed in cancer cells. To facilitate measurement of homologous recombination frequencies in normal cells, mutant cells, and cancer cells, we have developed a high titer retroviral vector containing tandem repeats of mutant versions of a GFP-Zeocin resistance fusion gene and an intact neomycin resistance marker. Recombination between the tandem repeats regenerates a functional GFP-Zeo(R) marker that can be easily scored. This retroviral vector was used to assess homologous recombination frequencies in human cancer cells and rodent fibroblasts with differing dosages of wild type or mutant p53. Absence of wild type p53 stimulated spontaneous and ionizing radiation-induced homologous recombination, confirming previous studies. Moreover, p53(+/-) mouse fibroblasts show elevated levels of homologous recombination compared to their p53(+/+) counterparts following retroviral vector infection, indicating that p53 is haploinsufficient for suppression of homologous recombination. Transfection of vector-containing p53 null Saos-2 cells with various human cancer-associated p53 mutants revealed that these altered p53 proteins retain some recombination suppression function despite being totally inactive for transcriptional transactivation. The retroviral vector utilized in these studies may be useful in performing recombination assays on a wide array of cell types, including those not readily transfected by normal vectors.

  2. Expression and In Silico Analysis of the Recombinant Bovine Papillomavirus E6 Protein as a Model for Viral Oncoproteins Studies

    Directory of Open Access Journals (Sweden)

    J. Mazzuchelli-de-Souza

    2013-01-01

    Full Text Available Bovine papillomaviruses (BPVs are recognized as the causal agents of economical relevant diseases in cattle, associated with the development of tumors in skin and mucosa. The oncogenesis process is mainly associated with different viral oncoprotein expressions, which are involved in cell transformation. The expression and characterization of recombinant viral oncoproteins represent an attractive strategy to obtain biotechnological products as antibodies and potential vaccines, Thus, the aim of this work was to clone and express the BPV-1 and BPV-2 E6 recombinant proteins and perform in silico analysis in order to develop a strategy for the systematic study of other papillomaviruses oncoproteins. The results demonstrated that BPV-1 and BPV-2 E6 recombinant proteins were expressed and purified from bacterial system as well as its in silico analysis was performed in order to explore and predict biological characteristics of these proteins.

  3. IONP-PLL: a novel non-viral vector for efficient gene delivery.

    Science.gov (United States)

    Xiang, Juan-Juan; Tang, Jing-Qun; Zhu, Shi-Guo; Nie, Xin-Min; Lu, Hong-Bin; Shen, Shou-Rong; Li, Xiao-Ling; Tang, Ke; Zhou, Ming; Li, Gui-Yuan

    2003-09-01

    Non-viral methods of gene delivery have been an attractive alternative to virus-based gene therapy. However, the vectors that are currently available have drawbacks limiting their therapeutic application. We have developed a self-assembled non-viral gene carrier, poly-L-lysine modified iron oxide nanoparticles (IONP-PLL), which is formed by modifying poly-L-lysine to the surface of iron oxide nanoparticles. The ability of IONP-PLL to bind DNA was determined by ratio-dependent retardation of DNA in the agarose gel and co-sedimentation assay. In vitro cytotoxic effects were quantified by MTT assay. The transfection efficiency in vitro was evaluated by delivering exogenous DNA to different cell lines using IONP-PLL. Intravenous injection of IONP-PLL/DNA complexes into mice was evaluated as a gene delivery system for gene therapy. The PGL2-control gene encoding firefly luciferase and the EGFP-C2 gene encoding green fluorescent protein were used as marker genes. IONP-PLL could bind and protect DNA. In contrast to PLL and cationic liposomes, IONP-PLL described here was less cytotoxic in a broad range of concentrations. In the current study, we have demonstrated that IONP-PLL can deliver exogenous gene to cells in vitro and in vivo. After intravenous injection, IONP-PLL transferred reporter gene EGFP-C2 to lung, brain, spleen and kidney. Furthermore, we have demonstrated that IONP-PLL transferred exogenous DNA across the blood-brain barrier to the glial cells and neuron of brain. IONP-PLL, a low-toxicity vector, appears to have potential for fundamental research and genetic therapy in vitro and in vivo, especially for gene therapy of CNS disease. Copyright 2003 John Wiley & Sons, Ltd.

  4. Chitosan-graft-polyethylenimine/DNA nanoparticles as novel non-viral gene delivery vectors targeting osteoarthritis.

    Science.gov (United States)

    Lu, Huading; Dai, Yuhu; Lv, Lulu; Zhao, Huiqing

    2014-01-01

    The development of safe and efficient gene carriers is the key to the clinical success of gene therapy. The present study was designed to develop and evaluate the chitosan-graft-polyethylenimine (CP)/DNA nanoparticles as novel non-viral gene vectors for gene therapy of osteoarthritis. The CP/DNA nanoparticles were produced through a complex coacervation of the cationic polymers with pEGFP after grafting chitosan (CS) with a low molecular weight (Mw) PEI (Mw = 1.8 kDa). Particle size and zeta potential were related to the weight ratio of CP:DNA, where decreases in nanoparticle size and increases in surface charge were observed as CP content increased. The buffering capacity of CP was significantly greater than that of CS. The transfection efficiency of CP/DNA nanoparticles was similar with that of the Lipofectamine™ 2000, and significantly higher than that of CS/DNA and PEI (25 kDa)/DNA nanoparticles. The transfection efficiency of the CP/DNA nanoparticles was dependent on the weight ratio of CP:DNA (w/w). The average cell viability after the treatment with CP/DNA nanoparticles was over 90% in both chondrocytes and synoviocytes, which was much higher than that of PEI (25 kDa)/DNA nanoparticles. The CP copolymers efficiently carried the pDNA inside chondrocytes and synoviocytes, and the pDNA was detected entering into nucleus. These results suggest that CP/DNA nanoparticles with improved transfection efficiency and low cytotoxicity might be a safe and efficient non-viral vector for gene delivery to both chondrocytes and synoviocytes.

  5. Enhancement of Mucosal Immunogenicity of Viral Vectored Vaccines by the NKT Cell Agonist Alpha-Galactosylceramide as Adjuvant

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    Shailbala Singh

    2014-10-01

    Full Text Available Gene-based vaccination strategies, specifically viral vectors encoding vaccine immunogens are effective at priming strong immune responses. Mucosal routes offer practical advantages for vaccination by ease of needle-free administration, and immunogen delivery at readily accessible oral/nasal sites to efficiently induce immunity at distant gut and genital tissues. However, since mucosal tissues are inherently tolerant for induction of immune responses, incorporation of adjuvants for optimal mucosal vaccination strategies is important. We report here the effectiveness of alpha-galactosylceramide (α-GalCer, a synthetic glycolipid agonist of natural killer T (NKT cells, as an adjuvant for enhancing immunogenicity of vaccine antigens delivered using viral vectors by mucosal routes in murine and nonhuman primate models. Significant improvement in adaptive immune responses in systemic and mucosal tissues was observed by including α-GalCer adjuvant for intranasal immunization of mice with vesicular stomatitis virus vector encoding the model antigen ovalbumin and adenoviral vectors expressing HIV env and Gag antigens. Activation of NKT cells in systemic and mucosal tissues along with significant increases in adaptive immune responses were observed in rhesus macaques immunized by intranasal and sublingual routes with protein or adenovirus vectored antigens when combined with α-GalCer adjuvant. These results support the utility of α-GalCer adjuvant for enhancing immunogenicity of mucosal vaccines delivered using viral vectors.

  6. Internalization of novel non-viral vector TAT-streptavidin into human cells

    Directory of Open Access Journals (Sweden)

    Kulomaa Markku S

    2007-01-01

    Full Text Available Abstract Background The cell-penetrating peptide derived from the Human immunodeficiency virus-1 transactivator protein Tat possesses the capacity to promote the effective uptake of various cargo molecules across the plasma membrane in vitro and in vivo. The objective of this study was to characterize the uptake and delivery mechanisms of a novel streptavidin fusion construct, TAT47–57-streptavidin (TAT-SA, 60 kD. SA represents a potentially useful TAT-fusion partner due to its ability to perform as a versatile intracellular delivery vector for a wide array of biotinylated molecules or cargoes. Results By confocal and immunoelectron microscopy the majority of internalized TAT-SA was shown to accumulate in perinuclear vesicles in both cancer and non-cancer cell lines. The uptake studies in living cells with various fluorescent endocytic markers and inhibiting agents suggested that TAT-SA is internalized into cells efficiently, using both clathrin-mediated endocytosis and lipid-raft-mediated macropinocytosis. When endosomal release of TAT-SA was enhanced through the incorporation of a biotinylated, pH-responsive polymer poly(propylacrylic acid (PPAA, nuclear localization of TAT-SA and TAT-SA bound to biotin was markedly improved. Additionally, no significant cytotoxicity was detected in the TAT-SA constructs. Conclusion This study demonstrates that TAT-SA-PPAA is a potential non-viral vector to be utilized in protein therapeutics to deliver biotinylated molecules both into cytoplasm and nucleus of human cells.

  7. [Aspirin-PEI-beta-CyD as a novel non-viral vector for gene transfer].

    Science.gov (United States)

    Wang, Zhong-Ren; Chen, Dan; Zhou, Jun; Tang, Gu-Ping

    2009-01-01

    To develop a novel non-viral gene delivery vector based on PEI-beta-CyD as backbone modified with aspirin, and to identify its physicochemical characters. 1, 1-carbonyldiimidazole (CDI) was used to bind aspirin onto PEI-beta-CyD to form PEI-beta-CyD-ASP. (1)H-NMR, FT-IR, UV and XRD were used to confirm the polymer structure. The ability of condensation was demonstrated by gel retardation assay. MTT assay was used to test the cell viability in B16, Hela and A293 cell lines. Transfection efficiency of the polymer was tested in B16 cells. The structure of PEI-beta-CyD-ASP was confirmed by (1)H-NMR, FT-IR, UV and XRD, which efficiently condensed plasmid DNA at the N/P ratio of 4. The copolymer showed low cytotoxicity and high transfection efficiency in B16 cells. The synthesized aspirin-PEI-beta-CyD might be a potential gene delivery vector.

  8. Neuropathological and behavioral consequences of adeno-associated viral vector-mediated continuous intrastriatal neurotrophin delivery in a focal ischemia model in rats.

    Science.gov (United States)

    Andsberg, Gunnar; Kokaia, Zaal; Klein, Ronald L; Muzyczka, Nicholas; Lindvall, Olle; Mandel, Ronald J

    2002-03-01

    Nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) were continuously delivered to the striatum at biologically active levels via recombinant adeno-associated viral (rAAV) gene transfer 4-5 weeks prior to 30 min of middle cerebral artery occlusion (MCAO). The magnitude of the deficits in a battery of behavioral tests designed to assess striatal function was highly correlated to the extent of ischemic damage determined by unbiased stereological estimations of striatal neuron numbers. The delivery of neurotrophins lead to mild functional improvements in the ischemia-induced motor impairments assessed 3-5 weeks after the insult, in agreement with a small but significant increase of the survival of dorsolateral striatal neurons. Detailed phenotypic analysis demonstrated that the parvalbumin-containing interneurons were spared to a greater extent by the neurotrophin treatment as compared to the projection neurons, which agreed with the specificity for interneuron transduction by the rAAV vector. These data show the advantage of the never previously performed combination of precise quantification of the ischemia-induced neuropathology along with detailed behavioural analysis for assessing neuroprotection after stroke. We observe that intrastriatal delivery of NGF and BDNF using a viral vector system can mitigate, albeit only moderately, neuronal death following stroke, which leads to detectable functional sparing.

  9. A simple vector system to improve performance and utilisation of recombinant antibodies

    Directory of Open Access Journals (Sweden)

    Vincent Karen J

    2006-12-01

    Full Text Available Abstract Background Isolation of recombinant antibody fragments from antibody libraries is well established using technologies such as phage display. Phage display vectors are ideal for efficient display of antibody fragments on the surface of bacteriophage particles. However, they are often inefficient for expression of soluble antibody fragments, and sub-cloning of selected antibody populations into dedicated soluble antibody fragment expression vectors can enhance expression. Results We have developed a simple vector system for expression, dimerisation and detection of recombinant antibody fragments in the form of single chain Fvs (scFvs. Expression is driven by the T7 RNA polymerase promoter in conjunction with the inducible lysogen strain BL21 (DE3. The system is compatible with a simple auto-induction culture system for scFv production. As an alternative to periplasmic expression, expression directly in the cytoplasm of a mutant strain with a more oxidising cytoplasmic environment (Origami 2™ (DE3 was investigated and found to be inferior to periplasmic expression in BL21 (DE3 cells. The effect on yield and binding activity of fusing scFvs to the N terminus of maltose binding protein (a solubility enhancing partner, bacterial alkaline phosphatase (a naturally dimeric enzymatic reporter molecule, or the addition of a free C-terminal cysteine was determined. Fusion of scFvs to the N-terminus of maltose binding protein increased scFv yield but binding activity of the scFv was compromised. In contrast, fusion to the N-terminus of bacterial alkaline phosphatase led to an improved performance. Alkaline phosphatase provides a convenient tag allowing direct enzymatic detection of scFv fusions within crude extracts without the need for secondary reagents. Alkaline phosphatase also drives dimerisation of the scFv leading to an improvement in performance compared to monovalent constructs. This is illustrated by ELISA, western blot and

  10. Complete Correction of Hemophilia A with Adeno-Associated Viral Vectors Containing a Full-Size Expression Cassette

    OpenAIRE

    Lu, Hui; Chen, Lingxia; Wang, Jinhui; Huack, Bernd; Sarkar, Rita; Zhou, Shangzhen; Xu, Ray; Ding, Qiulan; Wang, Xuefeng; Wang, HongLi; Xiao, Weidong

    2008-01-01

    Hemophilia A is caused by a deficiency in the factor VIII (FVIII) gene. Constrained by limited packaging capacity, even the 4.3-kb B domain-deleted FVIII remained a challenge for delivery by a single adeno-associated viral (AAV) vector. Studies have shown that up to a 6.6-kb vector sequence may be packaged into AAV virions, which suggested an alternative strategy for hemophilia A gene therapy. To explore the usefulness of AAV vectors carrying an oversized FVIII gene, we constructed the AAV-FV...

  11. Genetics and Genomics of Cotton Leaf Curl Disease, Its Viral Causal Agents and Whitefly Vector: A Way Forward to Sustain Cotton Fiber Security

    Directory of Open Access Journals (Sweden)

    Mehboob-ur- Rahman

    2017-07-01

    Full Text Available Cotton leaf curl disease (CLCuD after its first epidemic in 1912 in Nigeria, has spread to different cotton growing countries including United States, Pakistan, India, and China. The disease is of viral origin—transmitted by the whitefly Bemisia tabaci, which is difficult to control because of the prevalence of multiple virulent viral strains or related species. The problem is further complicated as the CLCuD causing virus complex has a higher recombination rate. The availability of alternate host crops like tomato, okra, etc., and practicing mixed type farming system have further exaggerated the situation by adding synergy to the evolution of new viral strains and vectors. Efforts to control this disease using host plant resistance remained successful using two gene based-resistance that was broken by the evolution of new resistance breaking strain called Burewala virus. Development of transgenic cotton using both pathogen and non-pathogenic derived approaches are in progress. In future, screening for new forms of host resistance, use of DNA markers for the rapid incorporation of resistance into adapted cultivars overlaid with transgenics and using genome editing by CRISPR/Cas system would be instrumental in adding multiple layers of defense to control the disease—thus cotton fiber production will be sustained.

  12. Genetics and Genomics of Cotton Leaf Curl Disease, Its Viral Causal Agents and Whitefly Vector: A Way Forward to Sustain Cotton Fiber Security.

    Science.gov (United States)

    Rahman, Mehboob-Ur-; Khan, Ali Q; Rahmat, Zainab; Iqbal, Muhammad A; Zafar, Yusuf

    2017-01-01

    Cotton leaf curl disease (CLCuD) after its first epidemic in 1912 in Nigeria, has spread to different cotton growing countries including United States, Pakistan, India, and China. The disease is of viral origin-transmitted by the whitefly Bemisia tabaci, which is difficult to control because of the prevalence of multiple virulent viral strains or related species. The problem is further complicated as the CLCuD causing virus complex has a higher recombination rate. The availability of alternate host crops like tomato, okra, etc., and practicing mixed type farming system have further exaggerated the situation by adding synergy to the evolution of new viral strains and vectors. Efforts to control this disease using host plant resistance remained successful using two gene based-resistance that was broken by the evolution of new resistance breaking strain called Burewala virus. Development of transgenic cotton using both pathogen and non-pathogenic derived approaches are in progress. In future, screening for new forms of host resistance, use of DNA markers for the rapid incorporation of resistance into adapted cultivars overlaid with transgenics and using genome editing by CRISPR/Cas system would be instrumental in adding multiple layers of defense to control the disease-thus cotton fiber production will be sustained.

  13. The specific transmission of Grapevine fanleaf virus by its nematode vector Xiphinema index is solely determined by the viral coat protein.

    Science.gov (United States)

    Andret-Link, Peggy; Schmitt-Keichinger, Corinne; Demangeat, Gérard; Komar, Véronique; Fuchs, Marc

    2004-03-01

    The viral determinants involved in the specific transmission of Grapevine fanleaf virus (GFLV) by its nematode vector Xiphinema index are located within the 513 C-terminal residues of the RNA2-encoded polyprotein, that is, the 9 C-terminal amino acids of the movement protein (2BMP) and contiguous 504 amino acids of the coat protein (2CCP) [Virology 291 (2001) 161]. To further delineate the viral determinants responsible for the specific spread, the four amino acids that are different within the 9 C-terminal 2BMP residues between GFLV and Arabis mosaic virus (ArMV), another nepovirus which is transmitted by Xiphinema diversicaudatum but not by X. index, were subjected to mutational analysis. Of the recombinant viruses derived from transcripts of GFLV RNA1 and RNA2 mutants that systemically infected herbaceous host plants, all with the 2CCP of GFLV were transmitted by X. index unlike none with the 2CCP of ArMV, regardless of the mutations within the 2BMP C-terminus. These results demonstrate that the coat protein is the sole viral determinant for the specific spread of GFLV by X. index.

  14. Developing a potentially immunologically inert tetracycline-regulatable viral vector for gene therapy in the peripheral nerve

    NARCIS (Netherlands)

    Hoyng, S A; Gnavi, S; de Winter, F; Eggers, R; Ozawa, T; Zaldumbide, A; Hoeben, R C; Malessy, M J A; Verhaagen, J

    2014-01-01

    Viral vector-mediated gene transfer of neurotrophic factors is an emerging and promising strategy to promote the regeneration of injured peripheral nerves. Unfortunately, the chronic exposure to neurotrophic factors results in local trapping of regenerating axons or other unwanted side effects. Ther

  15. A universal vector for high-efficiency multi-fragment recombineering of BACs and knock-in constructs.

    Science.gov (United States)

    Dolt, Karamjit Singh; Lawrence, Melanie L; Miller-Hodges, Eve; Slight, Joan; Thornburn, Anna; Devenney, Paul S; Hohenstein, Peter

    2013-01-01

    There is an increasing need for more efficient generation of transgenic constructs. Here we present a universal multi-site Gateway vector for use in recombineering reactions. Using transgenic mouse models, we show its use for the generation of BAC transgenics and targeting vectors. The modular nature of the vector allows for rapid modification of constructs to generate different versions of the same construct. As such it will help streamline the generation of series of related transgenic models.

  16. Priming Cross-Protective Bovine Viral Diarrhea Virus-Specific Immunity Using Live-Vectored Mosaic Antigens

    Science.gov (United States)

    Fang, Xin; Waghela, Suryakant D.; Bray, Jocelyn; Njongmeta, Leo M.; Herring, Andy; Abdelsalam, Karim W.; Chase, Christopher; Mwangi, Waithaka

    2017-01-01

    live vector in cattle, we showed that recombinant human adenovirus-5 was cleared within one week following intradermal inoculation. PMID:28099492

  17. Construction and immunogenicity of the recombinant Lactobacillus acidophilus pMG36e-E0-LA-5 of bovine viral diarrhea virus.

    Science.gov (United States)

    Zhao, Yuelan; Jiang, Lufeng; Liu, Teng; Wang, Min; Cao, Wenbo; Bao, Yongzhan; Qin, Jianhua

    2015-12-01

    Bovine viral diarrhea/mucosal disease (BVD/MD) is an infectious disease of cattle with a worldwide distribution, creating a substantial economic impact. It is caused by bovine viral diarrhea virus (BVDV). This research was conducted to construct the recombinant Lactobacillus acidophilus (L. acidophilus) pMG36e-E0-LA-5 of BVDV E0 gene and to test its immunogenicity and protective efficacy against BVDV infection in the mice model. The BVDV E0 gene was sub-cloned into the expression vector and then transformed into the L. acidophilus LA-5 strain by electroporation. The recombinant L. acidophilus pMG36e-E0-LA-5 was confirmed by the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting. The mice were immunized orally with the recombinant L. acidophilus pMG36e-E0-LA-5. The serum IgG antibody and fecal sIgA antibody responses, expression levels of interleukin (IL)-12 (IL-12) and interferon gamma (IFN-γ) were detected respectively. On the 7th day after the last-immunization, the mice were inoculated with BVDV to evaluate the protective efficiency of the recombinant L. acidophilus pMG36e-E0-LA-5. The results showed that the expressed products protein E0 in the L. acidophilus LA-5 resulted in single band of 27kDa by SDS-PAGE and its strong reactivity with BVDV antibody was confirmed by Western blotting. The IgG and sIgA antibodies responses, IL-12 and IFN-γ expression levels in the vaccinated mice with recombinant L. acidophilus pMG36e-E0-LA-5 were significantly higher than those in the control mice. The protective rate of the vaccinated mice against BVDV increased significantly, and a 90.00% protection rate in virulent challenge was observed. These results indicated that the recombinant L. acidophilus pMG36e-E0-LA-5 strain was successfully constructed and it could effectively improve the immune response in mice and might provide protection against BVDV.

  18. Production of Recombinant Cholera Toxin B Subunit in Nicotiana benthamiana Using GENEWARE® Tobacco Mosaic Virus Vector.

    Science.gov (United States)

    Moore, Lauren; Hamorsky, Krystal; Matoba, Nobuyuki

    2016-01-01

    Here, we describe a method to produce a recombinant cholera toxin B subunit in Nicotiana benthamiana plants (CTBp) using the GENEWARE(®) tobacco mosaic virus vector system. Infectious transcripts of the vector RNA are generated in vitro and inoculated on N. benthamiana seedlings. After 11 days, CTBp is extracted in a simple tris buffer at room temperature. No protease inhibitor is required. The leaf homogenate is treated with mild heat and a pH shift to selectively precipitate host-derived proteins. CTBp is purified to >95 % homogeneity by two-step chromatography using immobilized metal affinity and ceramic hydroxyapatite resins. This procedure yields on average 400 mg of low-endotoxin CTBp from 1 kg of fresh leaf material.

  19. Heterologous prime-boost-boost immunisation of Chinese cynomolgus macaques using DNA and recombinant poxvirus vectors expressing HIV-1 virus-like particles

    Directory of Open Access Journals (Sweden)

    Anson Donald S

    2011-09-01

    Full Text Available Abstract Background There is renewed interest in the development of poxvirus vector-based HIV vaccines due to the protective effect observed with repeated recombinant canarypox priming with gp120 boosting in the recent Thai placebo-controlled trial. This study sought to investigate whether a heterologous prime-boost-boost vaccine regimen in Chinese cynomolgus macaques with a DNA vaccine and recombinant poxviral vectors expressing HIV virus-like particles bearing envelopes derived from the most prevalent clades circulating in sub-Saharan Africa, focused the antibody response to shared neutralising epitopes. Methods Three Chinese cynomolgus macaques were immunised via intramuscular injections using a regimen composed of a prime with two DNA vaccines expressing clade A Env/clade B Gag followed by boosting with recombinant fowlpox virus expressing HIV-1 clade D Gag, Env and cholera toxin B subunit followed by the final boost with recombinant modified vaccinia virus Ankara expressing HIV-1 clade C Env, Gag and human complement protein C3d. We measured the macaque serum antibody responses by ELISA, enumerated T cell responses by IFN-γ ELISpot and assessed seroneutralisation of HIV-1 using the TZM-bl β-galactosidase assay with primary isolates of HIV-1. Results This study shows that large and complex synthetic DNA sequences can be successfully cloned in a single step into two poxvirus vectors: MVA and FPV and the recombinant poxviruses could be grown to high titres. The vaccine candidates showed appropriate expression of recombinant proteins with the formation of authentic HIV virus-like particles seen on transmission electron microscopy. In addition the b12 epitope was shown to be held in common by the vaccine candidates using confocal immunofluorescent microscopy. The vaccine candidates were safely administered to Chinese cynomolgus macaques which elicited modest T cell responses at the end of the study but only one out of the three macaques

  20. Clustered Integrin Ligands as a Novel Approach for the Targeting of Non-Viral Vectors

    Science.gov (United States)

    Ng, Quinn Kwan Tai

    Gene transfer or gene delivery is described as the process in which foreign DNA is introduced into cells. Over the years, gene delivery has gained the attention of many researchers and has been developed as powerful tools for use in biotechnology and medicine. With the completion of the Human Genome Project, such advances in technology allowed for the identification of diseases ranging from hereditary disorders to acquired ones (cancer) which were thought to be incurable. Gene therapy provides the means necessary to treat or eliminate genetic diseases from its origin, unlike traditional medicine which only treat symptoms. With ongoing clinical trials for gene therapy increasing, the greatest difficulty still lies in developing safe systems which can target cells of interest to provide efficient delivery. Nature, over millions of years of evolution, has provided an example of one of the most efficient delivery systems: viruses. Although the use of viruses for gene delivery has been well studied, the safety issues involving immunogenicity, insertional mutagenesis, high cost, and poor reproducibility has provided problems for their clinical application. From understanding viruses, we gain insight to designing new systems for non-viral gene delivery. One of these techniques utilized by adenoviruses is the clustering of ligands on its surface through the use of a protein called a penton base. Through the use of nanotechnology we can mimic this basic concept in non-viral gene delivery systems. This dissertation research is focused on developing and applying a novel system for displaying the integrin binding ligand (RGD) in a constrained manner to form a clustered integrin ligand binding platform to be used to enhance the targeting and efficiency of non-viral gene delivery vectors. Peptide mixed monolayer protected gold nanoparticles provides a suitable surface for ligand clustering. A relationship between the peptide ratios in the reaction solution used to form these

  1. A viral vectored prime-boost immunization regime targeting the malaria Pfs25 antigen induces transmission-blocking activity.

    Directory of Open Access Journals (Sweden)

    Anna L Goodman

    Full Text Available The ookinete surface protein Pfs25 is a macrogamete-to-ookinete/ookinete stage antigen of Plasmodium falciparum, capable of exerting high-level anti-malarial transmission-blocking activity following immunization with recombinant protein-in-adjuvant formulations. Here, this antigen was expressed in recombinant chimpanzee adenovirus 63 (ChAd63, human adenovirus serotype 5 (AdHu5 and modified vaccinia virus Ankara (MVA viral vectored vaccines. Two immunizations were administered to mice in a heterologous prime-boost regime. Immunization of mice with AdHu5 Pfs25 at week 0 and MVA Pfs25 at week 10 (Ad-MVA Pfs25 resulted in high anti-Pfs25 IgG titers, consisting of predominantly isotypes IgG1 and IgG2a. A single priming immunization with ChAd63 Pfs25 was as effective as AdHu5 Pfs25 with respect to ELISA titers at 8 weeks post-immunization. Sera from Ad-MVA Pfs25 immunized mice inhibited the transmission of P. falciparum to the mosquito both ex vivo and in vivo. In a standard membrane-feeding assay using NF54 strain P. falciparum, oocyst intensity in Anopheles stephensi mosquitoes was significantly reduced in an IgG concentration-dependent manner when compared to control feeds (96% reduction of intensity, 78% reduction in prevalence at a 1 in 5 dilution of sera. In addition, an in vivo transmission-blocking effect was also demonstrated by direct feeding of immunized mice infected with Pfs25DR3, a chimeric P. berghei line expressing Pfs25 in place of endogenous Pbs25. In this assay the density of Pfs25DR3 oocysts was significantly reduced when mosquitoes were fed on vaccinated as compared to control mice (67% reduction of intensity, 28% reduction in prevalence and specific IgG titer correlated with efficacy. These data confirm the utility of the adenovirus-MVA vaccine platform for the induction of antibodies with transmission-blocking activity, and support the continued development of this alternative approach to transmission-blocking malaria subunit

  2. Antigen Gene Transfer to Human Plasmacytoid Dendritic Cells Using Recombinant Adenovirus and Vaccinia Virus Vectors

    Directory of Open Access Journals (Sweden)

    Hetty J. Bontkes

    2005-01-01

    Full Text Available Recombinant adenoviruses (RAd and recombinant vaccinia viruses (RVV expressing tumour-associated antigens (TAA are used as anti-tumour vaccines. It is important that these vaccines deliver the TAA to dendritic cells (DC for the induction of a strong immune response. Infection of myeloid DC (MDC with RAd alone is relatively inefficient but CD40 retargeting significantly increases transduction efficiency and DC maturation. Infection with RVV is efficient without DC maturation. Plasmacytoid dendritic cells (PDC play a role in the innate immune response to viral infections through the secretion of IFNα but may also play a role in specific T-cell induction. The aim of our study was to investigate whether PDC are better targets for RAd and RVV based vaccines. RAd alone hardly infected PDC (2% while CD40 retargeting did not improve transduction efficiency, but it did increase PDC maturation (25% CD83 positive cells. Accordingly, specific CTL activation by RAd infected PDC was limited (the number of IFNγ producing CTL was reduced by 75% compared to stimulation with peptide loaded PDC. RVV infected PDC specifically stimulated CTL but PDC were not activated. These Results indicate that PDC are not ideal targets for RAd and RVV based vaccines. However, PDC induced specific CTL activation after pulsing with recombinant protein, indicating that PDC can also cross-present antigens released from surrounding infected cells.

  3. Immune responses to rAAV6: The influence of canine parvovirus vaccination and neonatal administration of viral vector

    Directory of Open Access Journals (Sweden)

    Andrea L H Arnett

    2011-11-01

    Full Text Available Recombinant adeno-associated viral (rAAV vectors promote long-term gene transfer in many animal species. Significant effort has focused on the evaluation of rAAV delivery and the immune response in both murine and canine models of neuromuscular disease. However, canines provided for research purposes are routinely vaccinated against canine parvovirus (CPV. rAAV and CPV possess significant homology and are both parvoviruses. Thus, any immune response generated to CPV vaccination has the potential to cross-react with rAAV vectors. In this study, we investigated the immune response to rAAV6 delivery in a cohort of CPV-vaccinated canines and evaluated multiple vaccination regimens in a mouse model of CPV-vaccination. We show that CPV-vaccination stimulates production of neutralizing antibodies with minimal cross-reactivity to rAAV6. In addition, no significant differences were observed in the magnitude of the rAAV6-directed immune response between CPV-vaccinated animals and controls. Moreover, CPV-vaccination did not inhibit rAAV6-mediated transduction. We also evaluated the immune response to early rAAV6-vaccination in neonatal mice. The influence of maternal hormones and cytokines leads to a relatively permissive state in the neonate. We hypothesized that immaturity of the immune system would permit induction of tolerance to rAAV6 when delivered during the neonatal period. Mice were vaccinated with rAAV6 at 1 or 5 days of age, and subsequently challenged with rAAV6 exposure during adulthood via two sequential IM injections, one month apart. All vaccinated animals generated a significant neutralizing antibody response to rAAV6-vaccination that was enhanced following IM injection in adulthood. Taken together, these data demonstrate that the immune response raised against rAAV6 is distinct from that which is elicited by the standard parvoviral vaccines and is sufficient to prevent stable tolerization in neonatal mice.

  4. Green fluorescent protein retroviral vectors: low titer and high recombination frequency suggest a selective disadvantage.

    Science.gov (United States)

    Hanazono, Y; Yu, J M; Dunbar, C E; Emmons, R V

    1997-07-20

    Green fluorescent protein (GFP) has been used as a reporter molecule for gene expression because it fluoresces green after blue-light excitation. Inclusion of this gene in a vector could allow rapid, nontoxic selection of successfully transduced cells. However, many attempts by our laboratory to isolate stable retroviral producer cell clones secreting biologically active vectors containing either the highly fluorescent S65T-GFP mutant or humanized GFP have failed. Vector plasmids containing various forms of GFP and the neomycin resistance gene were transfected into three different packaging cell lines and fluorescence was observed for several days, but stable clones selected with G418 no longer fluoresced. Using confocal microscopy, the brightest cells were observed to contract and die within a matter of days. RNA slot-blot analysis of retroviral producer supernatants showed no viral production from the GFP plasmid-transfected clones, although all clones derived after transfection with an identical retroviral construct not containing GFP produced virus. Genomic Southern analysis of the GFP-transduced clones showed a much higher probability of rearrangement of the priviral sequences than in the control non-GFP clones. Overall, 18/34 S65T-GFP clones and 17/33 humanized-GFP clones had rearrangements, whereas 2/15 control non-GFP clones had rearrangements. Hence, producer cells expressing high levels of these GFP genes seem to be selected against, with stable clones undergoing major rearrangements or other mutations that both abrogate GFP expression and prevent vector production. These observations indicate that GFP may not be an appropriate reporter gene for gene transfer applications in our vector/packaging system.

  5. Alteration of viral lipid composition by expression of the phospholipid floppase ABCB4 reduces HIV vector infectivity

    Directory of Open Access Journals (Sweden)

    van Til Niek P

    2008-02-01

    Full Text Available Abstract Background The presence of cholesterol in the Human Immunodeficiency Virus (HIV lipid envelop is important for viral function as cholesterol depleted viral particles show reduced infectivity. However, it is less well established whether other viral membrane lipids are also important for HIV infection. The ABCB4 protein is a phosphatidyl choline (PC floppase that mediates transport of PC from the inner to the outer membrane leaflet. This property enabled us to modulate the lipid composition of HIV vectors and study the effects on membrane composition and infection efficiency. Results Virus generated in the presence of ABCB4 was enriched in PC and cholesterol but contained less sphingomyelin (SM. Viral titers were reduced 5.9 fold. These effects were not observed with an inactive ABCB4 mutant. The presence of the ABC transport inhibitor verapamil abolished the effect of ABCB4 expression on viral titers. The ABCB4 mediated reduction in infectivity was caused by changes in the viral particles and not by components co purified with the virus because virus made in the presence of ABCB4 did not inhibit virus made without ABCB4 in a competition assay. Incorporation of the envelope protein was not affected by the expression of ABCB4. The inhibitory effect of ABCB4 was independent of the viral envelope as the effect was observed with two different envelope proteins. Conclusion Our data indicate that increasing the PC content of HIV particles reduces infectivity.

  6. Stability of Retroviral Vectors Against Ultracentrifugation Is Determined by the Viral Internal Core and Envelope Proteins Used for Pseudotyping.

    Science.gov (United States)

    Kim, Soo-Hyun; Lim, Kwang-Il

    2017-05-31

    Retroviral and lentiviral vectors are mostly pseudotyped and often purified and concentrated via ultracentrifugation. In this study, we quantified and compared the stabilities of retroviral [murine leukemia virus (MLV)-based] and lentiviral [human immunodeficiency virus (HIV)-1-based] vectors pseudotyped with relatively mechanically stable envelope proteins, vesicular stomatitis virus glycoproteins (VSVGs), and the influenza virus WSN strain envelope proteins against ultracentrifugation. Lentiviral genomic and functional particles were more stable than the corresponding retroviral particles against ultracentrifugation when pseudotyped with VSVGs. However, both retroviral and lentiviral particles were unstable when pseudotyped with the influenza virus WSN strain envelope proteins. Therefore, the stabilities of pseudotyped retroviral and lentiviral vectors against ultracentrifugation process are a function of not only the type of envelope proteins, but also the type of viral internal core (MLV or HIV-1 core). In addition, the fraction of functional viral particles among genomic viral particles greatly varied at times during packaging, depending on the type of envelope proteins used for pseudotyping and the viral internal core.

  7. A recombinant avian leukosis virus subgroup j for directly monitoring viral infection and the selection of neutralizing antibodies.

    Directory of Open Access Journals (Sweden)

    Qi Wang

    Full Text Available Avian leukosis virus subgroup J (ALV-J has induced serious clinical outbreaks and has become a serious infectious disease of chickens in China. We describe here the creation of a recombinant ALV-J tagged with the enhanced green fluorescent protein (named rHPRS-103EGFP. We successfully utilize the rHPRS-103EGFP to visualize viral infection and for development of a simplified serum-neutralization test.

  8. A recombinant avian leukosis virus subgroup j for directly monitoring viral infection and the selection of neutralizing antibodies.

    Science.gov (United States)

    Wang, Qi; Li, Xiaofei; Ji, Xiaolin; Wang, Jingfei; Shen, Nan; Gao, Yulong; Qi, Xiaole; Wang, Yongqiang; Gao, Honglei; Zhang, Shide; Wang, Xiaomei

    2014-01-01

    Avian leukosis virus subgroup J (ALV-J) has induced serious clinical outbreaks and has become a serious infectious disease of chickens in China. We describe here the creation of a recombinant ALV-J tagged with the enhanced green fluorescent protein (named rHPRS-103EGFP). We successfully utilize the rHPRS-103EGFP to visualize viral infection and for development of a simplified serum-neutralization test.

  9. Expression of VP7, a Bluetongue virus group specific antigen by viral vectors: analysis of the induced immune responses and evaluation of protective potential in sheep.

    Directory of Open Access Journals (Sweden)

    Coraline Bouet-Cararo

    Full Text Available Bluetongue virus (BTV is an economically important Orbivirus transmitted by biting midges to domestic and wild ruminants. The need for new vaccines has been highlighted by the occurrence of repeated outbreaks caused by different BTV serotypes since 1998. The major group-reactive antigen of BTV, VP7, is conserved in the 26 serotypes described so far, and its role in the induction of protective immunity has been proposed. Viral-based vectors as antigen delivery systems display considerable promise as veterinary vaccine candidates. In this paper we have evaluated the capacity of the BTV-2 serotype VP7 core protein expressed by either a non-replicative canine adenovirus type 2 (Cav-VP7 R0 or a leporipoxvirus (SG33-VP7, to induce immune responses in sheep. Humoral responses were elicited against VP7 in almost all animals that received the recombinant vectors. Both Cav-VP7 R0 and SG33-VP7 stimulated an antigen-specific CD4+ response and Cav-VP7 R0 stimulated substantial proliferation of antigen-specific CD8+ lymphocytes. Encouraged by the results obtained with the Cav-VP7 R0 vaccine vector, immunized animals were challenged with either the homologous BTV-2 or the heterologous BTV-8 serotype and viral burden in plasma was followed by real-time RT-PCR. The immune responses triggered by Cav-VP7 R0 were insufficient to afford protective immunity against BTV infection, despite partial protection obtained against homologous challenge. This work underscores the need to further characterize the role of BTV proteins in cross-protective immunity.

  10. Expression of VP7, a Bluetongue Virus Group Specific Antigen by Viral Vectors: Analysis of the Induced Immune Responses and Evaluation of Protective Potential in Sheep

    Science.gov (United States)

    Bouet-Cararo, Coraline; Contreras, Vanessa; Caruso, Agathe; Top, Sokunthea; Szelechowski, Marion; Bergeron, Corinne; Viarouge, Cyril; Desprat, Alexandra; Relmy, Anthony; Guibert, Jean-Michel; Dubois, Eric; Thiery, Richard; Bréard, Emmanuel; Bertagnoli, Stephane; Richardson, Jennifer; Foucras, Gilles; Meyer, Gilles; Schwartz-Cornil, Isabelle; Zientara, Stephan; Klonjkowski, Bernard

    2014-01-01

    Bluetongue virus (BTV) is an economically important Orbivirus transmitted by biting midges to domestic and wild ruminants. The need for new vaccines has been highlighted by the occurrence of repeated outbreaks caused by different BTV serotypes since 1998. The major group-reactive antigen of BTV, VP7, is conserved in the 26 serotypes described so far, and its role in the induction of protective immunity has been proposed. Viral-based vectors as antigen delivery systems display considerable promise as veterinary vaccine candidates. In this paper we have evaluated the capacity of the BTV-2 serotype VP7 core protein expressed by either a non-replicative canine adenovirus type 2 (Cav-VP7 R0) or a leporipoxvirus (SG33-VP7), to induce immune responses in sheep. Humoral responses were elicited against VP7 in almost all animals that received the recombinant vectors. Both Cav-VP7 R0 and SG33-VP7 stimulated an antigen-specific CD4+ response and Cav-VP7 R0 stimulated substantial proliferation of antigen-specific CD8+ lymphocytes. Encouraged by the results obtained with the Cav-VP7 R0 vaccine vector, immunized animals were challenged with either the homologous BTV-2 or the heterologous BTV-8 serotype and viral burden in plasma was followed by real-time RT-PCR. The immune responses triggered by Cav-VP7 R0 were insufficient to afford protective immunity against BTV infection, despite partial protection obtained against homologous challenge. This work underscores the need to further characterize the role of BTV proteins in cross-protective immunity. PMID:25364822

  11. Recombinant antigens from Phlebotomus perniciosus saliva as markers of canine exposure to visceral leishmaniases vector.

    Directory of Open Access Journals (Sweden)

    Jan Drahota

    Full Text Available BACKGROUND: Phlebotomus perniciosus is the main vector in the western Mediterranean area of the protozoan parasite Leishmania infantum, the causative agent of canine and human visceral leishmaniases. Infected dogs serve as a reservoir of the disease, and therefore measuring the exposure of dogs to sand fly bites is important for estimating the risk of L. infantum transmission. In bitten hosts, sand fly saliva elicits a specific antibody response that reflects the intensity of sand fly exposure. As screening of specific anti-saliva antibodies is limited by the availability of salivary gland homogenates, utilization of recombinant salivary proteins is a promising alternative. In this manuscript we show for the first time the use of recombinant salivary proteins as a functional tool for detecting P. perniciosus bites in dogs. METHODOLOGY/PRINCIPAL FINDINGS: The reactivity of six bacterially-expressed recombinant salivary proteins of P. perniciosus, yellow-related protein rSP03B, apyrases rSP01B and rSP01, antigen 5-related rSP07, ParSP25-like protein rSP08 and D7-related protein rSP04, were tested with sera of mice and dogs experimentally bitten by this sand fly using immunoblots and ELISA. In the immunoblots, both mice and canine sera gave positive reactions with yellow-related protein, both apyrases and ParSP25-like protein. A similar reaction for recombinant salivary proteins was observed by ELISA, with the reactivity of yellow-related protein and apyrases significantly correlated with the antibody response of mice and dogs against the whole salivary gland homogenate. CONCLUSIONS/SIGNIFICANCE: Three recombinant salivary antigens of P. perniciosus, yellow-related protein rSP03B and the apyrases rSP01B and rSP01, were identified as the best candidates for evaluating the exposure of mice and dogs to P. perniciosus bites. Utilization of these proteins, or their combination, would be beneficial for screening canine sera in endemic areas of visceral

  12. The emerging role of viral vectors as vehicles for DMD gene editing.

    Science.gov (United States)

    Maggio, Ignazio; Chen, Xiaoyu; Gonçalves, Manuel A F V

    2016-05-23

    Duchenne muscular dystrophy (DMD) is a genetic disorder caused by mutations in the dystrophin-encoding DMD gene. The DMD gene, spanning over 2.4 megabases along the short arm of the X chromosome (Xp21.2), is the largest genetic locus known in the human genome. The size of DMD, combined with the complexity of the DMD phenotype and the extent of the affected tissues, begs for the development of novel, ideally complementary, therapeutic approaches. Genome editing based on the delivery of sequence-specific programmable nucleases into dystrophin-defective cells has recently enriched the portfolio of potential therapies under investigation. Experiments involving different programmable nuclease platforms and target cell types have established that the application of genome-editing principles to the targeted manipulation of defective DMD loci can result in the rescue of dystrophin protein synthesis in gene-edited cells. Looking towards translation into the clinic, these proof-of-principle experiments have been swiftly followed by the conversion of well-established viral vector systems into delivery agents for DMD editing. These gene-editing tools consist of zinc-finger nucleases (ZFNs), engineered homing endoculeases (HEs), transcription activator-like effector nucleases (TALENs), and RNA-guided nucleases (RGNs) based on clustered, regularly interspaced, short palindromic repeats (CRISPR)-Cas9 systems. Here, we succinctly review these fast-paced developments and technologies, highlighting their relative merits and potential bottlenecks, when used as part of in vivo and ex vivo gene-editing strategies.

  13. Polyethylenimine: A versatile, multifunctional non-viral vector for nucleic acid delivery.

    Science.gov (United States)

    Pandey, Abhijeet P; Sawant, Krutika K

    2016-11-01

    Polyethylenimine (PEI) has recently been widely studied for the design of nucleic acid delivery vehicles. Gene delivery using PEI involves condensation of DNA into compact particles, uptake into the cells, release from the endosomal compartment into the cytoplasm, and uptake of the DNA into the nucleus. PEIs being positively charged, linear or branched polymers are able to form nanoscale complexes with small RNAs, leading to RNA protection, cellular delivery, and intracellular release. This review highlights the important properties of various PEIs with regard to their use for nucleic acid delivery. Brief discussion on cellular uptake mechanism of non-viral vector is included to understand its utility for gene delivery. Applications of modified PEI for increased efficacy, altered pharmacokinetic properties; improved biocompatibility and targeted delivery have also been discussed. An overview of simulation studies which can help in understanding the underlying complexation mechanism has also been included. The review provides a brief discussion about clinical trials and patents related to nucleic acid delivery using PEI based systems.

  14. Enzyme-synthesized Poly(amine-co-esters) as Non-viral Vectors for Gene Delivery

    Science.gov (United States)

    Liu, Jie; Jiang, Zhaozhong; Zhou, Jiangbing; Zhang, Shengmin; Saltzman, W. Mark

    2010-01-01

    A family of biodegradable poly(amine-co-esters) was synthesized in one step via enzymatic copolymerization of diesters with amino-substituted diols. Diesters of length C4–C12 (i.e., from succinate to dodecanedioate) were successfully copolymerized with diethanolamines with either an alkyl (methyl, ethyl, n-butyl, t-butyl) or an aryl (phenyl) substituent on the nitrogen. Upon protonation at slightly acidic conditions, these poly(amine-co-esters) readily turned to cationic polyelectrolytes, which were capable of condensing with polyanionic DNA to form nanometer-sized polyplexes. In vitro screening with pLucDNA revealed that two of the copolymers, poly(N-methyldiethyleneamine sebacate) (PMSC) and poly(N-ethyldiethyleneamine sebacate) (PESC), possessed comparable or higher transfection efficiencies compared to Lipofectamine 2000. PMSC/pLucDNA and PESC/pLucDNA nanoparticles had desirable particle sizes (40–70 nm) for cellular uptake and were capable of functioning as proton sponges to facilitate endosomal escape after cellular uptake. These polyplex nanoparticles exhibited extremely low cytotoxicity. Furthermore, in vivo gene transfection experiments revealed that PMSC is a substantially more effective gene carrier than PEI in delivering pLucDNAto cells in tumors in mice. All these properties suggest that poly(amine-co-esters) are promising non-viral vectors for safe and efficient DNA delivery in gene therapy. PMID:21171165

  15. Advances in Viral Vector-Based TRAIL Gene Therapy for Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Norian, Lyse A. [Department of Urology, University of Iowa Carver College of Medicine, Iowa City, IA 52242 (United States); James, Britnie R. [Interdisciplinary Graduate Program in Immunology, University of Iowa Carver College of Medicine, Iowa City, IA 52242 (United States); Griffith, Thomas S., E-mail: thomas-griffith@uiowa.edu [Department of Urology, University of Iowa Carver College of Medicine, Iowa City, IA 52242 (United States); Interdisciplinary Graduate Program in Immunology, University of Iowa Carver College of Medicine, Iowa City, IA 52242 (United States)

    2011-02-10

    Numerous biologic approaches are being investigated as anti-cancer therapies in an attempt to induce tumor regression while circumventing the toxic side effects associated with standard chemo- or radiotherapies. Among these, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has shown particular promise in pre-clinical and early clinical trials, due to its preferential ability to induce apoptotic cell death in cancer cells and its minimal toxicity. One limitation of TRAIL use is the fact that many tumor types display an inherent resistance to TRAIL-induced apoptosis. To circumvent this problem, researchers have explored a number of strategies to optimize TRAIL delivery and to improve its efficacy via co-administration with other anti-cancer agents. In this review, we will focus on TRAIL-based gene therapy approaches for the treatment of malignancies. We will discuss the main viral vectors that are being used for TRAIL gene therapy and the strategies that are currently being attempted to improve the efficacy of TRAIL as an anti-cancer therapeutic.

  16. Polyethylenimine functionalized magnetic nanoparticles as a potential non-viral vector for gene delivery.

    Science.gov (United States)

    Zhou, Yangbo; Tang, Zhaomin; Shi, Chunli; Shi, Shuai; Qian, Zhiyong; Zhou, Shaobing

    2012-11-01

    Polyethylenimine (PEI) functionalized magnetic nanoparticles were synthesized as a potential non-viral vector for gene delivery. The nanoparticles could provide the magnetic-targeting, and the cationic polymer PEI could condense DNA and avoid in vitro barriers. The magnetic nanoparticles were characterized by Fourier transform infrared spectroscopy, X-ray powder diffraction, dynamic light scattering measurements, transmission electron microscopy, vibrating sample magnetometer and atomic force microscopy. Agarose gel electrophoresis was used to asses DNA binding and perform a DNase I protection assay. The Alamar blue assay was used to evaluate negative effects on the metabolic activity of cells incubated with PEI modified magnetic nanoparticles and their complexes with DNA both in the presence or absence of an external magnetic field. Flow cytometry and fluorescent microscopy were also performed to investigate the transfection efficiency of the DNA-loaded magnetic nanoparticles in A549 and B16-F10 tumor cells with (+M) or without (-M) the magnetic field. The in vitro transfection efficiency of magnetic nanoparticles was improved obviously in a permanent magnetic field. Therefore, the magnetic nanoparticles show considerable potential as nanocarriers for gene delivery.

  17. Library selection and directed evolution approaches to engineering targeted viral vectors.

    Science.gov (United States)

    Jang, Jae-Hyung; Lim, Kwang-il; Schaffer, David V

    2007-10-15

    Gene therapy, to delivery of genetic material to a patient for therapeutic benefit, has significant promise for translating basic knowledge of disease mechanism into biomedical treatments. The clinical development of the field has been slowed, however, by the need for improvements in the properties and capabilities of gene delivery vehicles. Vehicles based on viruses offer the potential for efficient gene delivery, but because viruses did not evolve to serve human therapeutic needs, many of their properties require significant improvement, including their safety, efficiency, and capacity for targeted gene delivery. Since viruses are highly complex biological entities, engineering such properties at the molecular level can be challenging. However, there has been significant progress in developing approaches that mimic the mechanisms by which viruses arose in the first place. In particular, library-based selection, the generation of one diverse genetic library and selection for new properties, and directed evolution, based on the multiple rounds of library generation and selection for iterative improvement of function, have strong potential in engineering novel properties into these complex biomolecular assemblies. This review will discuss progress in the application of peptide display, library selection, and directed evolution technologies toward engineering vectors based on retrovirus, adeno-associated virus, and adenovirus that are capable of targeted delivery to specific cell types. In addition to creating biomedically useful products, these approaches have future potential to yield novel insights into viral structure-function relationships. Copyright 2007 Wiley Periodicals, Inc.

  18. Functional polycarbonates and their self-assemblies as promising non-viral vectors.

    Science.gov (United States)

    Seow, Wei Yang; Yang, Yi Yan

    2009-10-01

    Polycarbonates are promising biomaterials due to their biocompatibility, degradability and low toxicity. In this study, a series of COOH-functionalized polycarbonates was synthesized via an organocatalytic ring opening polymerization pathway under mild conditions. The polymers displayed a range of molecular weights (M(w): 3.1, 5.5 and 9.7 kDa) and were very narrowly distributed (polydispersity index: 1.07, 1.07 and 1.15 respectively). Aliphatic amines with different chain lengths (triethylenetetramine, tetraethylenepentamine or pentaethylenehexamine) were then conjugated onto the polycarbonate backbone using DIC/NHS chemistry. These amine-functionalized polycarbonates could form nanoparticles upon simple dissolution in water and had CMC values ranging from 22 to 45 mg/L. It was found that a longer amine chain resulted in greater buffering capacity, more positive zeta potential and smaller hydrodynamic size of the polymeric nanoparticles. Results from gel retardation assays indicated that the polymers were able to condense DNA. In-vitro studies further demonstrated that selected amine-functionalized polycarbonates could mediate efficient luciferase expression in HEK293, HepG2 and 4T1 cell lines at levels that were comparable, or even superior, to the polyethylenimine (PEI) standard. Importantly, minimal cytotoxicty was induced in the cells. These functional polycarbonates therefore have the potential to be a useful non-viral vector for gene therapy.

  19. Zn(II)-dipicolylamine-based metallo-lipids as novel non-viral gene vectors.

    Science.gov (United States)

    Su, Rong-Chuan; Liu, Qiang; Yi, Wen-Jing; Zhao, Zhi-Gang

    2017-08-01

    In this study, a series of Zn(II)-dipicolylamine (Zn-DPA) based cationic lipids bearing different hydrophobic tails (long chains, α-tocopherol, cholesterol or diosgenin) were synthesized. Structure-activity relationship (SAR) of these lipids was studied in detail by investigating the effects of several structural aspects including the type of hydrophobic tails, the chain length and saturation degree. In addition, several assays were used to study their interactions with plasmid DNA, and results reveal that these lipids could condense DNA into nanosized particles with appropriate size and zeta-potentials. MTT-based cell viability assays showed that lipoplexes 5 had low cytotoxicity. The in vitro gene transfection studies showed the hydrophobic tails clearly affected the TE, and hexadecanol-containing lipid 5b gives the best TE, which was 2.2 times higher than bPEI 25k in the presence of 10% serum. The results not only demonstrate that these lipids might be promising non-viral gene vectors, but also afford us clues for further optimization of lipidic gene delivery materials.

  20. Novel viral vectors utilizing intron splice-switching to activate genome rescue, expression and replication in targeted cells

    Directory of Open Access Journals (Sweden)

    El Andaloussi Samir

    2011-05-01

    Full Text Available Abstract Background The outcome of virus infection depends from the precise coordination of viral gene expression and genome replication. The ability to control and regulate these processes is therefore important for analysis of infection process. Viruses are also useful tools in bio- and gene technology; they can efficiently kill cancer cells and trigger immune responses to tumors. However, the methods for constructing tissue- or cell-type specific viruses typically suffer from low target-cell specificity and a high risk of reversion. Therefore novel and universal methods of regulation of viral infection are also important for therapeutic application of virus-based systems. Methods Aberrantly spliced introns were introduced into crucial gene-expression units of adenovirus vector and alphavirus DNA/RNA layered vectors and their effects on the viral gene expression, replication and/or the release of infectious genomes were studied in cell culture. Transfection of the cells with splice-switching oligonucleotides was used to correct the introduced functional defect(s. Results It was demonstrated that viral gene expression, replication and/or the release of infectious genomes can be blocked by the introduction of aberrantly spliced introns. The insertion of such an intron into an adenovirus vector reduced the expression of the targeted gene more than fifty-fold. A similar insertion into an alphavirus DNA/RNA layered vector had a less dramatic effect; here, only the release of the infectious transcript was suppressed but not the subsequent replication and spread of the virus. However the insertion of two aberrantly spliced introns resulted in an over one hundred-fold reduction in the infectivity of the DNA/RNA layered vector. Furthermore, in both systems the observed effects could be reverted by the delivery of splice-switching oligonucleotide(s, which corrected the splicing defects. Conclusions Splice-switch technology, originally developed for

  1. A novel and highly efficient production system for recombinant adeno-associated virus vector

    Institute of Scientific and Technical Information of China (English)

    WU; Zhijian(伍志坚); WU; Xiaobing(吴小兵); CAO; Hui(曹晖); DONG; Xiaoyan(董小岩); WANG; Hong(王宏); HOU; Yunde(侯云德)

    2002-01-01

    Recombinant adeno-associated virus(rAAV) has proven to be a promising gene delivery vector for human gene therapy. However, its application has been limited by difficulty in obtaining enough quantities of high-titer vector stocks. In this paper, a novel and highly efficient production system for rAAV is described. A recombinant herpes simplex virus type 1(rHSV-1) designated HSV1-rc/△UL2, which expressed adeno-associated virus type2(AAV-2) Rep and Cap proteins, was constructed previously. The data confirmed that its functions were to support rAAV replication and packaging, and the generated rAAV was infectious. Meanwhile, an rAAV proviral cell line designated BHK/SG2, which carried the green fluorescent protein(GFP) gene expression cassette, was established by transfecting BHK-21 cells with rAAV vector plasmid pSNAV-2-GFP. Infecting BHK/SG2 with HSV1-rc/△UL2 at an MOI of 0.1 resulted in the optimal yields of rAAV, reaching 250 transducing unit(TU) or 4.28×104 particles per cell. Therefore, compared with the conventional transfection method, the yield of rAAV using this "one proviral cell line, one helper virus" strategy was increased by two orders of magnitude. Large-scale production of rAAV can be easily achieved using this strategy and might meet the demands for clinical trials of rAAV-mediated gene therapy.

  2. Expression of IMP1 enhances production of murine leukemia virus vector by facilitating viral genomic RNA packaging.

    Directory of Open Access Journals (Sweden)

    Yun Mai

    Full Text Available Murine leukemia virus (MLV-based retroviral vector is widely used for gene transfer. Efficient packaging of the genomic RNA is critical for production of high-titer virus. Here, we report that expression of the insulin-like growth factor II mRNA binding protein 1 (IMP1 enhanced the production of infectious MLV vector. Overexpression of IMP1 increased the stability of viral genomic RNA in virus producer cells and packaging of the RNA into progeny virus in a dose-dependent manner. Downregulation of IMP1 in virus producer cells resulted in reduced production of the retroviral vector. These results indicate that IMP1 plays a role in regulating the packaging of MLV genomic RNA and can be used for improving production of retroviral vectors.

  3. Expression of IMP1 enhances production of murine leukemia virus vector by facilitating viral genomic RNA packaging.

    Science.gov (United States)

    Mai, Yun; Gao, Guangxia

    2010-12-29

    Murine leukemia virus (MLV)-based retroviral vector is widely used for gene transfer. Efficient packaging of the genomic RNA is critical for production of high-titer virus. Here, we report that expression of the insulin-like growth factor II mRNA binding protein 1 (IMP1) enhanced the production of infectious MLV vector. Overexpression of IMP1 increased the stability of viral genomic RNA in virus producer cells and packaging of the RNA into progeny virus in a dose-dependent manner. Downregulation of IMP1 in virus producer cells resulted in reduced production of the retroviral vector. These results indicate that IMP1 plays a role in regulating the packaging of MLV genomic RNA and can be used for improving production of retroviral vectors.

  4. A viral vector expressing hypoxia-inducible factor 1 alpha inhibits hippocampal neuronal apoptosis

    Institute of Scientific and Technical Information of China (English)

    Xiqing Chai; Weina Kong; Lingyun Liu; Wenguo Yu; Zhenqing Zhang; Yimin Sun

    2014-01-01

    Hypoxia-inducible factor 1 (HIF-1) attenuates amyloid-beta protein neurotoxicity and decreases apoptosis induced by oxidative stress or hypoxia in cortical neurons. In this study, we construct-ed a recombinant adeno-associated virus (rAAV) vector expressing the human HIF-1αgene (rAAV-HIF-1α), and tested the assumption that rAAV-HIF-1αrepresses hippocampal neuronal apoptosis induced by amyloid-beta protein. Our results conifrmed that rAAV-HIF-1αsigniifcant-ly reduces apoptosis induced by amyloid-beta protein in primary cultured hippocampal neurons. Direct intracerebral rAAV-HIF-1αadministration also induced robust and prolonged HIF-1αproduction in rat hippocampus. Single rAAV-HIF-1αadministration resulted in decreased apoptosis of hippocampal neurons in an Alzheimer’s disease rat model established by intrace-rebroventricular injection of aggregated amyloid-beta protein (25-35). Our in vitro and in vivo ifndings demonstrate that HIF-1 has potential for attenuating hippocampal neuronal apoptosis induced by amyloid-beta protein, and provides experimental support for treatment of neurode-generative diseases using gene therapy.

  5. Effect of recombinant adenovirus vector mediated human interleukin-24 gene transfection on pancreatic carcinoma growth

    Institute of Scientific and Technical Information of China (English)

    PAN Xin-ting; ZHU Qing-yun; LI De-chun; YANG Ji-cheng; ZHANG Zi-xiang; ZHU Xing-guo; ZHAO Hua

    2008-01-01

    Background Pancreatic cancer is a highly malignant tumor affecting an ever increasing number of patients with a mean 5-year survival rate below 4%. Therefore, gene therapy for cancer has become a potential novel therapeutic modality. In this study we sought to determine the inhibitory effects of adenovirus-mediated human interleukin-24 (AdhlL-24) on pancreatic cancer.Methods Human interleukin-24 gene was cloned into replication-defective adenovirus specific for patu8988 tumor cells by virus recombination technology. Reverse transcription-polymerase chain reaction and Western blotting analysis were used to determine the expression of human interleukin-24 mRNA in patu8988 cells in vitro. Induction of apoptosis by overexpression of human interleukin-24 in patu8988 cells was determined by flow cytometry. In vivo efficacy of adenoviral delivery of human interleukin-24 was assessed in nude mice (n=10 for each group) bearing patu8988 pancreatic cancer cell lines by determining inhibition of tumor growth, endothelial growth factor and CD34 expression, and intratumoral microvessel density (MVD).Results The recombinant adenovirus vector AdVGFP/IL-24 was constructed with a packaged recombinant retrovirus titer of 1.0x1010 pfu/ml and successfully expressed of both mRNA and protein in patu8988 cells. The AdVGFP/IL-24 induced apoptosis of patu8988 tumor cells in vitro and significantly inhibited tumor growth in vivo (P <0.05). The intratumoral MVD decreased significantly in the treated tumors (P <0.05).Conclusion The recombinant adenovirus AdGFP/IL-24 can effectively express biologically active human interleukin-24, which results in inhibition of pancreatic cancer growth.

  6. Rapid high-yield expression of full-size IgG antibodies in plants coinfected with noncompeting viral vectors.

    Science.gov (United States)

    Giritch, Anatoli; Marillonnet, Sylvestre; Engler, Carola; van Eldik, Gerben; Botterman, Johan; Klimyuk, Victor; Gleba, Yuri

    2006-10-03

    Plant viral vectors allow expression of heterologous proteins at high yields, but so far, they have been unable to express heterooligomeric proteins efficiently. We describe here a rapid and indefinitely scalable process for high-level expression of functional full-size mAbs of the IgG class in plants. The process relies on synchronous coinfection and coreplication of two viral vectors, each expressing a separate antibody chain. The two vectors are derived from two different plant viruses that were found to be noncompeting. Unlike vectors derived from the same virus, noncompeting vectors effectively coexpress the heavy and light chains in the same cell throughout the plant body, resulting in yields of up to 0.5 g of assembled mAbs per kg of fresh-leaf biomass. This technology allows production of gram quantities of mAbs for research purposes in just several days, and the same protocol can be used on an industrial scale in situations requiring rapid response, such as pandemic or terrorism events.

  7. Effects of recombinant adenoviral vector containing IRE1α gene on proliferation and apoptosis of ATDC5 stem cells

    Directory of Open Access Journals (Sweden)

    Xiang-zhu LI

    2013-09-01

    Full Text Available Objective To construct the recombinant adenoviral vector containing human IRE1α (type I transmembrane protein kinase/endoribonucleasegene, and investigate its effects on proliferation and apoptosis of ATDC5 stem cells. Methods  By using pAdEasyTM adenovirus vector system, the recombinant shuttle vectors of IRE1α full-length gene(pAdTrack-IRE1αand RNase+Kinasedomain(pAdTrack-R+Kwere constructed, and then transferred with pAdEasy-1 to generate recombinant adenovirus plasmid pAd-IRE1α and pAd-R+K by electroporation method. Subsequently, the plasmids were transfected into HEK-293 cells to pack and amplify the recombinant adenovirus Ad-IRE1α and Ad-R+K. The expression of recombinant adenovirus was detected by PCR. The ATDC5 cells wereinfected in vitro by recombinant adenovirus Ad-IRE1α and Ad-R+K, the infection efficiency of green fluorescent protein(GFPwas observed, and the influence of Ad-IRE1α and Ad-R+K on the proliferation and apoptosis of ATDC5 cells under endoplasmic reticulum stress(ERS or non-ERS was detected by flow cytometry(FCM. Results Restriction endonuclease digestion analysis and PCR indicated that the recombinant adenovirus vector Ad-IRE1α andAd-R+K was successfully constructed. FCM detection showed that under ERS conditions, the G1 phasedcreased and S phase increased in ATDC5 cells after transfected by Ad-IRE1α and Ad-R+K, meanwhile the apoptosis rate increased significantly(P<0.05. Conclusion Infection of recombinant adenovirus containing IRE1α gene may promote the proliferation and apoptosis of ATDC5cells.

  8. Mucosal vaccination with heterologous viral vectored vaccine targeting subdominant SIV accessory antigens strongly inhibits early viral replication

    DEFF Research Database (Denmark)

    Xu, Huanbin; Andersson, Anne-Marie; Ragonnaud, Emeline

    2017-01-01

    Conventional HIV T cell vaccine strategies have not been successful in containing acute peak viremia, nor in providing long-term control. We immunized rhesus macaques intramuscularly and rectally using a heterologous adenovirus vectored SIV vaccine regimen encoding normally weakly immunogenic tat...

  9. Is passive transmission of non-viral vectors through artificial insemination of sperm-DNA mixtures sufficient for chicken transgenesis?

    OpenAIRE

    CHAPARIAN, Shahram; ABDULAHNEJAD, Ahad; RASHIDI, Farzad; Toghyani, Majid; Gheisari, Abbasali; Eghbalsaied, Shahin

    2016-01-01

    DNA uptake in the post-acrosomal region of the spermatozoa takes place exclusively in immotile spermatozoa that are naturally unable to fertilize eggs. The present study aimed to assess whether passive transmission of non-viral vectors to the surrounding areas of chicken embryos could be an alternate mechanism in chicken sperm-mediated gene transfer. First, the presence of nucleases in rooster seminal plasma was evaluated. Semen ejaculates from five roosters were centrifuged and the supernata...

  10. The yellow fever 17D vaccine virus: molecular basis of viral attenuation and its use as an expression vector

    Directory of Open Access Journals (Sweden)

    Galler R.

    1997-01-01

    Full Text Available The yellow fever (YF virus is the prototype flavivirus. The use of molecular techniques has unraveled the basic mechanisms of viral genome structure and expression. Recent trends in flavivirus research include the use of infectious clone technology with which it is possible to recover virus from cloned cDNA. Using this technique, mutations can be introduced at any point of the viral genome and their resulting effect on virus phenotype can be assessed. This approach has opened new possibilities to study several biological viral features with special emphasis on the issue of virulence/attenuation of the YF virus. The feasibility of using YF virus 17D vaccine strain, for which infectious cDNA is available, as a vector for the expression of heterologous antigens is reviewed

  11. Presencia de rotavirus durante un proceso de compostaje. Abonos como vectores de contaminación viral

    Directory of Open Access Journals (Sweden)

    María Mercedes Martínez

    2009-12-01

    Full Text Available Rotavirus presence in a waste composting process. Organic fertilizers as vehicles for viral contamination. Objective. To show thepresence of rotavirus in different stages of a composting process: matrices used as raw material, mixture to be composted and the finalproduct. Materials and methods. Immunochromatography, ELISA and RT-PCR were used for viral detection. Results. Rotavirus wasfound in the first composting step, no virus was found in the second step, and some inhibitory substances were found in the third step thatposed difficulties in interpreting the PCR results and therefore providing a concluding result on rotavirus presence in the final product.Conclusions. Organic fertilizers can be vectors of human pathogenic viruses; therefore quality control tests must be implemented to avoidfurther viral dissemination. There are inhibitory substances present in organic fertilizers capable of interfering with the detection tests.

  12. Diseño y construcción de vectores de transferencia para la obtención de virus vaccinia Ankara modificado (MVA recombinantes Design and construction of transfer vectors in order to obtain recombinant modified vaccinia virus Ankara (MVA

    Directory of Open Access Journals (Sweden)

    M. F. Ferrer

    2007-09-01

    Full Text Available El virus vaccinia Ankara modificado (MVA constituye un buen candidato para el desarrollo de vectores virales de expresión no replicativos porque no replica en la mayoría de las células de mamíferos. Para la producción de MVA recombinantes es fundamental disponer de vectores de transferencia que, por recombinación homóloga con el genoma viral, permitan introducir los genes de interés en regiones no esenciales para la replicación in vitro. En este trabajo se diseñaron y obtuvieron los vectores de transferencia denominados VT-MHA y VT-MTK que portan las regiones correspondientes a las posiciones 1-303 y 608-948 del gen MVA165R y 1-244 y 325-534 del gen MVA086R, respectivamente, las que flanquean un sitio de clonado múltiple para la inserción de los genes foráneos. En dichos vectores se clonaron los casetes para la expresión de los genes lac Z o uid A, y la actividad de las enzimas marcadoras b-galactosidasa y b-glucuronidasa se confirmó in situ. Además, utilizando el vector denominado VT-MTK-GUS, se obtuvieron y aislaron MVA recombinantes puros que portan y expresan el gen uid A. Los resultados obtenidos constituyen las herramientas básicas para establecer la metodología de obtención de MVA recombinantes, con el propósito de desarrollar localmente vectores virales no replicativos candidatos a vacunas.Modified Vaccinia virus Ankara (MVA constitutes a good candidate for the development of non-replicative expression viral vectors because it does not replicate in most of mammalian cells. It is essential, for the production of recombinant MVA, the availability of transfer vectors which allow the introduction of desired genes into non-essential regions for in vitro viral replication, by homologous recombination with the viral genome. In the present work, the transfer vectors named VT-MHA and VT-MTK were designed and obtained. They carried genomic regions corresponding to 1- 303 and 608-948 positions of the MVA165R gene and 1-244 and

  13. A novel multi-antigen virally vectored vaccine against Mycobacterium avium subspecies paratuberculosis.

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    Tim J Bull

    Full Text Available BACKGROUND: Mycobacterium avium subspecies paratuberculosis causes systemic infection and chronic intestinal inflammation in many species including primates. Humans are exposed through milk and from sources of environmental contamination. Hitherto, the only vaccines available against Mycobacterium avium subspecies paratuberculosis have been limited to veterinary use and comprised attenuated or killed organisms. METHODS: We developed a vaccine comprising a fusion construct designated HAV, containing components of two secreted and two cell surface Mycobacterium avium subspecies paratuberculosis proteins. HAV was transformed into DNA, human Adenovirus 5 (Ad5 and Modified Vaccinia Ankara (MVA delivery vectors. Full length expression of the predicted 95 kDa fusion protein was confirmed. PRINCIPAL FINDINGS: Vaccination of naïve and Mycobacterium avium subspecies paratuberculosis infected C57BL/6 mice using DNA-prime/MVA-boost or Ad5-prime/MVA-boost protocols was highly immunogenic resulting in significant IFN-gamma ELISPOT responses by splenocytes against recombinant vaccine antigens and a range of HAV specific peptides. This included strong recognition of a T-cell epitope GFAEINPIA located near the C-terminus of the fusion protein. Antibody responses to recombinant vaccine antigens and HAV specific peptides but not GFAEINPIA, also occurred. No immune recognition of vaccine antigens occurred in any sham vaccinated Mycobacterium avium subspecies paratuberculosis infected mice. Vaccination using either protocol significantly attenuated pre-existing Mycobacterium avium subspecies paratuberculosis infection measured by qPCR in spleen and liver and the Ad5-prime/MVA-boost protocol also conferred some protection against subsequent challenge. No adverse effects of vaccination occurred in any of the mice. CONCLUSIONS/SIGNIFICANCE: A range of modern veterinary and clinical vaccines for the treatment and prevention of disease caused by Mycobacterium avium

  14. NIH oversight of human gene transfer research involving retroviral, lentiviral, and adeno-associated virus vectors and the role of the NIH recombinant DNA advisory committee.

    Science.gov (United States)

    O'Reilly, Marina; Shipp, Allan; Rosenthal, Eugene; Jambou, Robert; Shih, Tom; Montgomery, Maureen; Gargiulo, Linda; Patterson, Amy; Corrigan-Curay, Jacqueline

    2012-01-01

    In response to public and scientific concerns regarding human gene transfer research, the National Institutes of Health (NIH) developed a transparent oversight system that extends to human gene transfer protocols that are either conducted with NIH funding or conducted at institutions that receive NIH funding for recombinant DNA research. The NIH Recombinant DNA Advisory Committee (RAC) has been the primary advisory body to NIH regarding the conduct of this research. Human gene transfer research proposals that are subject to the NIH Guidelines for Research Involving Recombinant DNA Molecules (NIH Guidelines) must be submitted to the NIH Office of Biotechnology Activities (OBA), and protocols that raise novel scientific, safety, medical, ethical, or social issues are publicly discussed at the RAC's quarterly public meetings. OBA also convenes gene transfer safety symposia and policy conferences to provide a public forum for scientific experts to discuss emerging issues in the field. This transparent system of review promotes the rapid exchange of important scientific information and dissemination of data. The goal is to optimize the conduct of individual research protocols and to advance gene transfer research generally. This process has fostered the development of retroviral, lentiviral, and adeno-associated viral vector mediated gene delivery.

  15. Use of homologous recombination in yeast to create chimeric bovine viral diarrhea virus cDNA clones

    Directory of Open Access Journals (Sweden)

    Sandra Arenhart

    Full Text Available Abstract The open reading frame of a Brazilian bovine viral diarrhea virus (BVDV strain, IBSP4ncp, was recombined with the untranslated regions of the reference NADL strain by homologous recombination in Saccharomyces cerevisiae, resulting in chimeric full-length cDNA clones of BVDV (chi-NADL/IBSP4ncp#2 and chi-NADL/IBSP4ncp#3. The recombinant clones were successfully recovered, resulting in viable viruses, having the kinetics of replication, focus size, and morphology similar to those of the parental virus, IBSP4ncp. In addition, the chimeric viruses remained stable for at least 10 passages in cell culture, maintaining their replication efficiency unaltered. Nucleotide sequencing revealed a few point mutations; nevertheless, the phenotype of the rescued viruses was nearly identical to that of the parental virus in all experiments. Thus, genetic stability of the chimeric clones and their phenotypic similarity to the parental virus confirm the ability of the yeast-based homologous recombination to maintain characteristics of the parental virus from which the recombinant viruses were derived. The data also support possible use of the yeast system for the manipulation of the BVDV genome.

  16. Use of homologous recombination in yeast to create chimeric bovine viral diarrhea virus cDNA clones.

    Science.gov (United States)

    Arenhart, Sandra; Silva, José Valter Joaquim; Flores, Eduardo Furtado; Weiblen, Rudi; Gil, Laura Helena Vega Gonzales

    The open reading frame of a Brazilian bovine viral diarrhea virus (BVDV) strain, IBSP4ncp, was recombined with the untranslated regions of the reference NADL strain by homologous recombination in Saccharomyces cerevisiae, resulting in chimeric full-length cDNA clones of BVDV (chi-NADL/IBSP4ncp#2 and chi-NADL/IBSP4ncp#3). The recombinant clones were successfully recovered, resulting in viable viruses, having the kinetics of replication, focus size, and morphology similar to those of the parental virus, IBSP4ncp. In addition, the chimeric viruses remained stable for at least 10 passages in cell culture, maintaining their replication efficiency unaltered. Nucleotide sequencing revealed a few point mutations; nevertheless, the phenotype of the rescued viruses was nearly identical to that of the parental virus in all experiments. Thus, genetic stability of the chimeric clones and their phenotypic similarity to the parental virus confirm the ability of the yeast-based homologous recombination to maintain characteristics of the parental virus from which the recombinant viruses were derived. The data also support possible use of the yeast system for the manipulation of the BVDV genome. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  17. Activation of the cellular unfolded protein response by recombinant adeno-associated virus vectors.

    Directory of Open Access Journals (Sweden)

    Balaji Balakrishnan

    Full Text Available The unfolded protein response (UPR is a stress-induced cyto-protective mechanism elicited towards an influx of large amount of proteins in the endoplasmic reticulum (ER. In the present study, we evaluated if AAV manipulates the UPR pathways during its infection. We first examined the role of the three major UPR axes, namely, endoribonuclease inositol-requiring enzyme-1 (IRE1α, activating transcription factor 6 (ATF6 and PKR-like ER kinase (PERK in AAV infected cells. Total RNA from mock or AAV infected HeLa cells were used to determine the levels of 8 different ER-stress responsive transcripts from these pathways. We observed a significant up-regulation of IRE1α (up to 11 fold and PERK (up to 8 fold genes 12-48 hours after infection with self-complementary (scAAV2 but less prominent with single-stranded (ssAAV2 vectors. Further studies demonstrated that scAAV1 and scAAV6 also induce cellular UPR in vitro, with AAV1 vectors activating the PERK pathway (3 fold while AAV6 vectors induced a significant increase on all the three major UPR pathways [6-16 fold]. These data suggest that the type and strength of UPR activation is dependent on the viral capsid. We then examined if transient inhibition of UPR pathways by RNA interference has an effect on AAV transduction. siRNA mediated silencing of PERK and IRE1α had a modest effect on AAV2 and AAV6 mediated gene expression (∼1.5-2 fold in vitro. Furthermore, hepatic gene transfer of scAAV2 vectors in vivo, strongly elevated IRE1α and PERK pathways (2 and 3.5 fold, respectively. However, when animals were pre-treated with a pharmacological UPR inhibitor (metformin during scAAV2 gene transfer, the UPR signalling and its subsequent inflammatory response was attenuated concomitant to a modest 2.8 fold increase in transgene expression. Collectively, these data suggest that AAV vectors activate the cellular UPR pathways and their selective inhibition may be beneficial during AAV mediated gene transfer.

  18. Complete correction of hemophilia A with adeno-associated viral vectors containing a full-size expression cassette.

    Science.gov (United States)

    Lu, Hui; Chen, Lingxia; Wang, Jinhui; Huack, Bernd; Sarkar, Rita; Zhou, Shangzhen; Xu, Ray; Ding, Qiulan; Wang, Xuefeng; Wang, Hongli; Xiao, Weidong

    2008-06-01

    Hemophilia A is caused by a deficiency in the factor VIII (FVIII) gene. Constrained by limited packaging capacity, even the 4.3-kb B domain-deleted FVIII remained a challenge for delivery by a single adeno-associated viral (AAV) vector. Studies have shown that up to a 6.6-kb vector sequence may be packaged into AAV virions, which suggested an alternative strategy for hemophilia A gene therapy. To explore the usefulness of AAV vectors carrying an oversized FVIII gene, we constructed the AAV-FVIII vector under the control of a beta-actin promoter with a cytomegalovirus enhancer (CB) and a bovine growth hormone (bGH) poly(A) sequence. The CB promoter plus bGH signal was shown to be 3- to 5-fold more potent than the mini-transthyretin (TTR) promoter with a synthetic poly(A) sequence for directing FVIII expression in the liver. Despite the 5.75-kb genome size of pAAV-CB-FVIII, sufficient AAV vectors were produced for in vivo testing. Approximately 3- to 5-fold more FVIII secretion was observed in animals receiving AAV-CB-FVIII vectors than in those receiving standard-sized AAV-TTR-FVIII vectors. Both the activated partial thromboplastin time assay and the whole blood thromboelastographic analysis confirmed that AAV-FVIII vectors fully corrected the bleeding phenotype of hemophilia mice. These results suggest that AAV vectors with an oversized genome should be useful for not only hemophilia A gene therapy but also other diseases with large cDNA such as muscular dystrophy and cystic fibrosis.

  19. Gene therapy for allergic rhinitis with recombinant adenovirus vector containing CTLA4Ig in mice

    Institute of Scientific and Technical Information of China (English)

    朱瑾; 吴军; 陈希炜; 易绍萱; 罗高兴; 贺伟峰

    2003-01-01

    Objective: To examine the role of recombinant adenovirus vector containing CTLA4Ig gene(Ad-CTLA4Ig) in the treatment of induced allergic rhinitis in mice.Methods: Allergic rhinitis was induced by sensitizing and challenging with ovalbumin(OVA).Ad-CTLA4Ig was intraperitoneally injected 30 min before OVA challenge.Adenovirus vector without inserted CTLA4Ig cDNA served as the control.The symptoms and morphological changes of nasal mucosa of each group were observed, and the serum levels of IgE against OVA were detected with ELISA.Results: There were no obvious symptoms and pathological changes in Ad-CTLA4Ig treated group, in which the serum OVA-specific IgE levels were significantly lower than that in control groups(P< 0.05).Conclusion: Ad-CTLA4Ig prevents and treats allergic rhinitis of mice,implying the possibility of the usage of Ad-CTLA4Ig against allergic rhinitis in clinic in future.

  20. Peripheral transvenular delivery of adeno-associated viral vectors to skeletal muscle as a novel therapy for hemophilia B

    Science.gov (United States)

    Arruda, Valder R.; Stedman, Hansell H.; Haurigot, Virginia; Buchlis, George; Baila, Stefano; Favaro, Patricia; Chen, Yifeng; Franck, Helen G.; Zhou, Shangzhen; Wright, J. Fraser; Couto, Linda B.; Jiang, Haiyan; Pierce, Glenn F.; Bellinger, Dwight A.; Mingozzi, Federico; Nichols, Timothy C.

    2010-01-01

    Muscle represents an important tissue target for adeno-associated viral (AAV) vector-mediated gene transfer of the factor IX (FIX) gene in hemophilia B (HB) subjects with advanced liver disease. Previous studies of direct intramuscular administration of an AAV-FIX vector in humans showed limited efficacy. Here we adapted an intravascular delivery system of AAV vectors encoding the FIX transgene to skeletal muscle of HB dogs. The procedure, performed under transient immunosuppression (IS), resulted in widespread transduction of muscle and sustained, dose-dependent therapeutic levels of canine FIX transgene up to 10-fold higher than those obtained by intramuscular delivery. Correction of bleeding time correlated clinically with a dramatic reduction of spontaneous bleeding episodes. None of the dogs (n = 14) receiving the AAV vector under transient IS developed inhibitory antibodies to canine FIX; transient inhibitor was detected after vector delivery without IS. The use of AAV serotypes with high tropism for muscle and low susceptibility to anti-AAV2 antibodies allowed for efficient vector administration in naive dogs and in the presence of low- but not high-titer anti-AAV2 antibodies. Collectively, these results demonstrate the feasibility of this approach for treatment of HB and highlight the importance of IS to prevent immune responses to the FIX transgene product. PMID:20335222

  1. Peripheral transvenular delivery of adeno-associated viral vectors to skeletal muscle as a novel therapy for hemophilia B.

    Science.gov (United States)

    Arruda, Valder R; Stedman, Hansell H; Haurigot, Virginia; Buchlis, George; Baila, Stefano; Favaro, Patricia; Chen, Yifeng; Franck, Helen G; Zhou, Shangzhen; Wright, J Fraser; Couto, Linda B; Jiang, Haiyan; Pierce, Glenn F; Bellinger, Dwight A; Mingozzi, Federico; Nichols, Timothy C; High, Katherine A

    2010-06-10

    Muscle represents an important tissue target for adeno-associated viral (AAV) vector-mediated gene transfer of the factor IX (FIX) gene in hemophilia B (HB) subjects with advanced liver disease. Previous studies of direct intramuscular administration of an AAV-FIX vector in humans showed limited efficacy. Here we adapted an intravascular delivery system of AAV vectors encoding the FIX transgene to skeletal muscle of HB dogs. The procedure, performed under transient immunosuppression (IS), resulted in widespread transduction of muscle and sustained, dose-dependent therapeutic levels of canine FIX transgene up to 10-fold higher than those obtained by intramuscular delivery. Correction of bleeding time correlated clinically with a dramatic reduction of spontaneous bleeding episodes. None of the dogs (n = 14) receiving the AAV vector under transient IS developed inhibitory antibodies to canine FIX; transient inhibitor was detected after vector delivery without IS. The use of AAV serotypes with high tropism for muscle and low susceptibility to anti-AAV2 antibodies allowed for efficient vector administration in naive dogs and in the presence of low- but not high-titer anti-AAV2 antibodies. Collectively, these results demonstrate the feasibility of this approach for treatment of HB and highlight the importance of IS to prevent immune responses to the FIX transgene product.

  2. Construction of a recombinant adenovirus Vector of human papillomavirus type 16 L1_E7c

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Human papillomaviruses are closely associated with human cervical cancer, especially HPV types 16 and 18. At present, HPV can not be produced in large quantity; it also has tumorgenicity and these properties of HPV have seriously hampered the development of HPV vaccine. HPV type 16 L1 proteins can assembled into virus-like particles (VLP), which are morphologically identical to the nature virion. In order to develop the recombinant adenovirus vectors of HPV, we constructed a recombinant adenovirus shuttle plasmid pCA14 L1-E7c. Methods: Human papillomavirus type 16 L1 open reading frame without terminator codon (TAA) (5559- 7152) and E7c (682- 855) were amplified using PCR. The L1 and E7c fragments were inserted into pGEM-T easy vectors by T- A strategy, named pTAL1 and pTAE7c. pTAL1 was cut with Hind III and BglII, the pTAE7c with BamHI and ClaI. The L1 DNA fragment, E7c and pBluesscript SK were ligated together using T4 DNA ligase. pBSL1-E7c and pBSL1-E7c was digested with Hind III and Xhol. The L1-E7c fragment was inserted into adenovirus shuttle plasmids pCAl4, named pCAl4L1-E7c. DNA sequence results indicated that The L1-E7c DNA fragment can encode the HPV16L1-E7 fusion protein correctly. Results: The L1 and E7c DNA fragments were amplified by PCR and recombinant plasmid pTAL1, pTAE7c, pBSL1-E7c and pCA14L1-E7c were constructed correctly. The pCAl4L1-E7c can be used in the further research work, cotransfected the 293 cell with the parent adenovirus pBHG10. Conclusion: Our results indicated that we have constructed a HPV16L1-E7 fusion DNA fragments and the adenovirus shuttle plasmids pCALl-E7c for the further research.

  3. Incorporating double copies of a chromatin insulator into lentiviral vectors results in less viral integrants

    DEFF Research Database (Denmark)

    Nielsen, Troels T; Jakobsson, Johan; Rosenqvist, Nina;

    2009-01-01

    BACKGROUND: Lentiviral vectors hold great promise as gene transfer vectors in gene therapeutic settings. However, problems related to the risk of insertional mutagenesis, transgene silencing and positional effects have stalled the use of such vectors in the clinic. Chromatin insulators are boundary...

  4. Constructionof the recombinant adenovirus vectors of CALB2 gene and small interfering RNA, and application in testicular Leydig cells

    Institute of Scientific and Technical Information of China (English)

    Luo Jian; Wang Jing; Liu Shan; Sun Xue-ping; Gao Chao; Gao Li; Yang Xiao-yu; Liu Jia-yin; Cui Yu-gui

    2011-01-01

    Objective:To construct the recombinant adenovirus vectors of calretinin (CALB2) gene and small interfering RNA (siRNA),for over-expression or knock-down of CALB2,as the basis of functional investigation of CALB2 in testicular Leydig cells.Methods:The cDNA sequence of CALB2 was cloned by the reverse transcriptive polymerase chain reaction (RT-PCR).A CALB2 gene fragment was sub-cloned into adenovirus shuttle plasmid pAdTrack-CMV to construct the shuttle plasmid pAdTrack-CALB2.Then it was transformed into BJ5183 cells with the adenoviral backbone pAdEasy-1 to obtain the homologous recombinant AdCMV-CALB2.The recombinant AdCMV-CALB2 was further packaged and amplificated in AD293 cells.The expression of CALB2 protein in AD293 cells was detected by Western blotting.CALB2 protein was over-expressed in mouse Leydig cell line (MLTC-1 cells) by the constructed AdCMVCALB2.CALB2 gene siRNA recombinant adenovirus vector (Ad-H1-siRNA/CALB2 was also constructed simultaneously.Its efficacy was detected in AD293 cells by Western blotting.Results:The CALB2 gene recombinant adenovirus vector AdCMV-CALB2 and the CALB2 gene siRNA recombinant adenovirus vector Ad-H1-siRNA/CALB2 were constructed successfully by endonulease digestion and sequencing.AD293 cells infected with AdCMV-CALB2 or Ad-H1-SiRNA/CALB2 significantly expressed GFP protein.The expression of CALB2 protein was significantly up-regulated in AD293 cells infected with AdCMV-CALB2 plasmids,while the expression of CALB2 protein was down-regulated by 60% in the CALB2 cells infected with Ad-H1SiRNA/CALB2.MLTC-1 cells did not markedly express CALLB2 protein,while MLTC-1 cells infected with AdCMV-CALB2 expressed CALB2 protein at a high level.Conclusions:The recombinant adenovirus vectors of AdCMV-CALB2 and Ad-H1-SiRNA/CALB2 were successfully constructed.Both vectors effectively expressed in AD293.CALB2 protein was over-expressed in the cultured MLTC-1 cells by AdCMV-CALB2.These vectors of CALB2 gene and Leydig cell line are

  5. A new method for rapidly generating gene-targeting vectors by engineering BACs through homologous recombination in bacteria.

    Science.gov (United States)

    Cotta-de-Almeida, Vinicius; Schonhoff, Susan; Shibata, Tomoyuki; Leiter, Andrew; Snapper, Scott B

    2003-09-01

    Generating knockout mice is still an expensive and highly time-consuming process. Target construct generation, the first labor-intensive step in this process, requires the manipulation of large fragments of DNA and numerous, and often cumbersome, cloning steps. Here we show the development of a rapid approach for generating targeting constructs that capitalizes on efficient homologous recombination between linear DNA fragments and circular plasmids in Escherichia coli ("recombineering"), the availability of bacterial artificial chromosomes (BACs), and the accessibility of the sequence of the mouse genome. Employing recombineering, we demonstrate with only 1-2 template plasmids, short homologies (40-50bp) between donor and target DNA, and one subcloning step that we can efficiently manipulate BACs in situ to generate a complicated targeting vector. This procedure avoids the need to construct or screen genomic libraries and permits the generation of most standard, conditional, or knock-in targeting vectors, often within two weeks.

  6. Recombinant viral-vectored vaccines for the control of avian influenza in poultry

    Science.gov (United States)

    Vaccination is a commonly used tool for the control of both low pathogenic and highly pathogenic avian influenza viruses. Traditionally inactivated adjuvanted vaccines made from a low pathogenic field strain has been used for vaccination, but advances in molecular biology has allowed a number of di...

  7. Tumor-Specific Targeting With Modified Sindbis Viral Vectors: Evaluation with Optical Imaging and Positron Emission Tomography In Vivo

    Science.gov (United States)

    Stelter, Lars; Tseng, Jen-Chieh; Torosjan, Armen; Levin, Brandi; Longo, Valerie A.; Pillarsetty, Nagavarakishore; Zanzonico, Pat; Meruelo, Daniel; Daniel, Steven M.

    2015-01-01

    Purpose Sindbis virus (SINV) infect tumor cells specifically and systemically throughout the body. Sindbis vectors are capable of expressing high levels of transduced suicide genes and thus efficiently produce enzymes for prodrug conversion in infected tumor cells. The ability to monitor suicide gene expression levels and viral load in patients, after administration of the vectors, would significantly enhance this tumor-specific therapeutic option. Procedures The tumor specificity of SINV is mediated by the 67-kDa laminin receptor (LR). We probed different cancer cell lines for their LR expression and, to determine the specific role of LR-expression in the infection cycle, used different molecular imaging strategies, such as bioluminescence, fluorescence molecular tomography, and positron emission tomography, to evaluate SINV-mediated infection in vitro and in vivo. Results All cancer cell lines showed a marked expression of LR. The infection rates of the SINV particles, however, differed significantly among the cell lines. Conclusion We used novel molecular imaging techniques to visualize vector delivery to different neoplatic cells. SINV infection rates proofed to be not solely dependent on cellular LR expression. Further studies need to evaluate the herein discussed ways of cellular infection and viral replication. PMID:22847302

  8. Construction of the recombinant vector carrying herpes simplex virus thymidine kinase and cytokine genes expressed in cell line Tca8113

    Institute of Scientific and Technical Information of China (English)

    JI Guang-hui; ZOU Jing-zhi; QU Le; YUE Ying; KUAI Jian-ke

    2004-01-01

    Objective: To construct expression vector containing fusion genes of herpes simplex virus thymidine kinase(Hsv-tk), Interleukin-2(IL-2) with internal ribosome entry sites(IRES), and to assess their expression in cell lineTca8113. Methods: IL-2 cDNA was obtained by reverse transcription. Hsv-tk, IL-2 and IRES genes were amplified by PCR. The purified amplification products were inserted into pGEM-T-Easy, and transformed into E. coli JM109. The purified recombinant plasmids were identified by restriction endonucleases. The recombinant plasmids were digested and pEGFPN3 were linearized, DNA fragments of Hsv-tk, IRES and IL-2 were ligated into linearized pEGFP-N3, and then transferred into E. coli JM109. The recombinant tk-IL-2 genes were cloned separately and introduced into the expression vector pEGFPN3 containing GFP. The recombinant vectors were identified by their restriction sites through PCR. The plasmids pEGFP-TI was also transfected into Tca8113 cells by calcium phosphate method for the expression of fusion proteins. Fusion genes expressing vector PL(TI)SN was generated by the fusion of HSV-tk, IRES and IL-2 with the use of DNA recombination technology. The recombinant retroviruses were transferred into Tca8113 cells by lipofectamine. The positive clones were obtained after G418 selection and named Tca/TI respectively. Results: The pEGFP-TI pasmid was identified respectively by restriction endonucleases, and their fragment sizes were 1 120 bp and 450 bp. The pEGFP-TI pasmid as templates were amplified respectively by PCR, and their PCR products were 1 120 bp and 450 bp. The pEGFP-TI vectors were used to transfect Tca8113 cell, and the cells with fluorescence accounted for 60 % of the total amount. Conclusion: pFGFP- tk- IRES- IL-2 expressing vector is easy to assess the expression of tk-IRES-IL-2-GFP fusion protein localization in transfected cells. The successful construction of expressing vector containing fusion genes of Hsv-tk, IRES and IL-2 may be

  9. Bioresorbable microporous stents deliver recombinant adenovirus gene transfer vectors to the arterial wall.

    Science.gov (United States)

    Ye, Y W; Landau, C; Willard, J E; Rajasubramanian, G; Moskowitz, A; Aziz, S; Meidell, R S; Eberhart, R C

    1998-01-01

    The use of intravascular stents as an adjunct for percutaneous transluminal revascularization is limited by two principal factors, acute thrombosis and neointimal proliferation, resulting in restenosis. To overcome these limitations, we have investigated the potential of microporous bioresorbable polymer stents formed from poly(L-lactic acid) (PLLA)/poly(epsilon-caprolactone) (PCL) blends to function both to provide mechanical support and as reservoirs for local delivery of therapeutic molecules and particles to the vessel wall. Tubular PLLA/PCL stents were fabricated by the flotation-precipitation method, and helical stents were produced by a casting/winding technique. Hybrid structures in which a tubular sheath is deposited on a helical skeleton were also generated. Using a two-stage solvent swelling technique, polyethylene oxide has been incorporated into these stents to improve hydrophilicity and water uptake, and to facilitate the ability of these devices to function as drug carriers. Stents modified in this manner retain axial and radial mechanical strength sufficient to stabilize the vessel wall against elastic recoil caused by vasoconstrictive and mechanical forces. Because of the potential of direct gene transfer into the vessel wall to ameliorate thrombosis and neointimal proliferation, we have investigated the capacity of these polymer stents to function in the delivery of recombinant adenovirus vectors to the vessel wall. In vitro, virus stock was observed to readily absorb into, and elute from these devices in an infectious form, with suitable kinetics. Successful gene transfer and expression has been demonstrated following implantation of polymer stents impregnated with a recombinant adenovirus carrying a nuclear-localizing betaGal reporter gene into rabbit carotid arteries. These studies suggest that surface-modified polymer stents may ultimately be useful adjunctive devices for both mechanical support and gene transfer during percutaneous

  10. Replication-competent infectious hepatitis B virus vectors carrying substantially sized transgenes by redesigned viral polymerase translation.

    Directory of Open Access Journals (Sweden)

    Zihua Wang

    Full Text Available Viral vectors are engineered virus variants able to deliver nonviral genetic information into cells, usually by the same routes as the parental viruses. For several virus families, replication-competent vectors carrying reporter genes have become invaluable tools for easy and quantitative monitoring of replication and infection, and thus also for identifying antivirals and virus susceptible cells. For hepatitis B virus (HBV, a small enveloped DNA virus causing B-type hepatitis, such vectors are not available because insertions into its tiny 3.2 kb genome almost inevitably affect essential replication elements. HBV replicates by reverse transcription of the pregenomic (pg RNA which is also required as bicistronic mRNA for the capsid (core protein and the reverse transcriptase (Pol; their open reading frames (ORFs overlap by some 150 basepairs. Translation of the downstream Pol ORF does not involve a conventional internal ribosome entry site (IRES. We reasoned that duplicating the overlap region and providing artificial IRES control for translation of both Pol and an in-between inserted transgene might yield a functional tricistronic pgRNA, without interfering with envelope protein expression. As IRESs we used a 22 nucleotide element termed Rbm3 IRES to minimize genome size increase. Model plasmids confirmed its activity even in tricistronic arrangements. Analogous plasmids for complete HBV genomes carrying 399 bp and 720 bp transgenes for blasticidin resistance (BsdR and humanized Renilla green fluorescent protein (hrGFP produced core and envelope proteins like wild-type HBV; while the hrGFP vector replicated poorly, the BsdR vector generated around 40% as much replicative DNA as wild-type HBV. Both vectors, however, formed enveloped virions which were infectious for HBV-susceptible HepaRG cells. Because numerous reporter and effector genes with sizes of around 500 bp or less are available, the new HBV vectors should become highly useful tools to

  11. Copackaging of multiple adeno-associated viral vectors in a single production step.

    Science.gov (United States)

    Doerfler, Phillip A; Byrne, Barry J; Clément, Nathalie

    2014-10-01

    Limiting factors in large preclinical and clinical studies utilizing adeno-associated virus (AAV) for gene therapy are focused on the restrictive packaging capacity, the overall yields, and the versatility of the production methods for single AAV vector production. Furthermore, applications where multiple vectors are needed to provide long expression cassettes, whether because of long cDNA sequences or the need of different regulatory elements, require that each vector be packaged and characterized separately, directly affecting labor and cost associated with such manufacturing strategies. To overcome these limitations, we propose a novel method of vector production that allows for the packaging of multiple expression cassettes in a single transfection step. Here we combined two expression cassettes in predetermined ratios before transfection and empirically demonstrate that the output vector recapitulates the predicted ratios. Titration by quantitative polymerase chain reaction of AAV vector genome copies using shared or unique genetic elements allowed for delineation of the individual vector contribution to the total preparation that showed the predicted differential packaging outcomes. By copackaging green fluorescent protein (GFP) and mCherry constructs, we demonstrate that both vector genome and infectious titers reiterated the ratios utilized to produce the constructs by transfection. Copackaged therapeutic constructs that only differ in transcriptional elements produced a heterogeneous vector population of both constructs in the predefined ratios. This study shows feasibility and reproducibility of a method that allows for two constructs, differing in either transgene or transcription elements, to be efficiently copackaged and characterized simultaneously, reducing cost of manufacturing and release testing.

  12. Kunjin virus replicons: an RNA-based, non-cytopathic viral vector system for protein production, vaccine and gene therapy applications

    NARCIS (Netherlands)

    Pijlman, G.P.; Suhrbier, A.; Khromykh, A.A.

    2006-01-01

    The application of viral vectors for gene expression and delivery is rapidly evolving, with several entering clinical trials. However, a number of issues, including safety, gene expression levels, cell selectivity and antivector immunity, are driving the search for new vector systems. A number of re

  13. Adeno-associated viral vector serotypes 1 and 5 targeted to the neonatal rat and pig striatum induce widespread transgene expression in the forebrain

    DEFF Research Database (Denmark)

    Kornum, Birgitte R; Stott, Simon R W; Mattsson, Bengt;

    2010-01-01

    . Our results show that striatal delivery of rAAV5 vectors in the neonatal brain represents a useful tool to express genes of interest both in the basal ganglia and the neocortex. Furthermore, we apply, for the first time, viral vector-mediated gene transfer to the pig brain providing the opportunity...

  14. Advances in research on non-viral vectors for gene delivery%非病毒基因递送载体的研究进展

    Institute of Scientific and Technical Information of China (English)

    胡星

    2012-01-01

    目前,基因药物的递送成为药学研究的热点,基因递送载体主要包括病毒载体和非病毒载体.非病毒基因载体的毒性低,生物相容性好,转染效率高,具有潜在的临床应用价值.本文就靶向递送基因载体、多功能基因载体、同时载基因与化疗药物的载体、智能基因载体和脂质体等非病毒基因递送载体的研究进展做一综述.%Currently,the delivery of gene drugs has become the hot point of pharmaceutical research. Viral and non-viral vectors are the two major vehicles for gene delivery. Non-viral vectors have the advantages of low toxicity,good biocompatibility and high efficiency of transfection, showing great potential for clinical use. Advances in research on non-viral vectors, such as targeting gene vectors, multifunctional gene vectors, intelligent gene vectors, gene vectors which simultaneously carry chemo-therapeutic drugs, and liposome gene vectors are reviewed in this paper.

  15. Recombinant Listeria monocytogenes as a Live Vaccine Vehicle for the Induction of Protective Anti-Viral Cell-Mediated Immunity

    Science.gov (United States)

    Shen, Hao; Slifka, Mark K.; Matloubian, Mehrdad; Jensen, Eric R.; Ahmed, Rafi; Miller, Jeff F.

    1995-04-01

    Listeria monocytogenes (LM) is a Gram-positive bacterium that is able to enter host cells, escape from the endocytic vesicle, multiply within the cytoplasm, and spread directly from cell to cell without encountering the extracellular milieu. The ability of LM to gain access to the host cell cytosol allows proteins secreted by the bacterium to efficiently enter the pathway for major histocompatibility complex class I antigen processing and presentation. We have established a genetic system for expression and secretion of foreign antigens by recombinant strains, based on stable site-specific integration of expression cassettes into the LM genome. The ability of LM recombinants to induce protective immunity against a heterologous pathogen was demonstrated with lymphocytic choriomeningitis virus (LCMV). LM strains expressing the entire LCMV nucleoprotein or an H-2L^d-restricted nucleoprotein epitope (aa 118-126) were constructed. Immunization of mice with LM vaccine strains conferred protection against challenge with virulent strains of LCMV that otherwise establish chronic infection in naive adult mice. In vivo depletion of CD8^+ T cells from vaccinated mice abrogated their ability to clear viral infection, showing that protective anti-viral immunity was due to CD8^+ T cells.

  16. Modification of a viral satellite DNA-based gene silencing vector and its application to leaf or flower color change in Petunia hybrida

    Institute of Scientific and Technical Information of China (English)

    TAO Xiaorong; QIAN Yajuan; ZHOU Xueping

    2006-01-01

    Virus-induced gene silencing offers a powerful reverse-genetic tool for the study of gene function in plants. We have previously reported effective gene silencing of plant genes using a viral satellite DNA associated with Tomato yellow leaf curl China virus (TYLCCNV). In this study, we further modified the viral satellite DNA-based vector. The modified vector can induce sulfu (Su) gene silencing as effective as the original vector in Nicotiana benthamiana plants, but the new system simplifies procedures for construction of vector derivative. Furthermore, a fragment of petunia Su or chalcone synthase (CHS) endogenous gene was inserted into the modified vector. When petunia plants were agro- inoculated with the modified vector carrying a Su or CHS gene, the Su silenced plants started to appear yellowing in veins of systemically infected upper leaves two weeks after agroinoculation, while the CHS silenced plants started to show flower color change one month after agroinoculation and later single-color flowers became mosaic.

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

    Science.gov (United States)

    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.

  18. Combined immunity of DNA vector and recombinant vaccinia virus expressing Gag proteins of equine infectious anemia virus

    Institute of Scientific and Technical Information of China (English)

    DAI Chunming; ZHANG Xiaoyan; WANG Shuhui; LIU Ying; DUAN Danli; SHEN Rongxian; SHAO Yiming

    2004-01-01

    In order to develop a new vaccine candidate for equine infectious anemia virus (EIAV), gag gene of Chinese donkey leukocyte attenuated strain (EIAV DLV) and its parental virulent strain (EIAV LN) were inserted respectively into the TK region of the Tiantan strain (VV) of vaccinia virus by homologous recombination and the positive clone was confirmed by blue plaque assay. Protein expression was examined by Western blot. Prime and prime-boost procedures were used to immunize mice with two DNA vectors and two recombinant vaccinia viruses expressing EIAV Gag proteins. The results showed that the specific lysis of CTL responses in the DNA+rVV groups was stronger than those in the DNA groups, amounting to 31%. Although the levels of specific antibodies were not significantly different, we could conclude that the recombinant vaccinia virus could boost the cellular responses following DNA vector priming. There was no detectable difference between the immune responses induced by DLV and LN Gag proteins. This data demonstrates that the combined immunity of DNA vector and recombinant vaccinia virus expressing EIAV gag proteins, utilizing the prime-boost procedure, can drive immunized mice to produce powerful cellular responses. These results lay an important foundation for the development of a new EIAV genetic engineering vaccine.

  19. Recombinant alphaviruses as vectors for anti-tumour and anti-microbial immunotherapy

    NARCIS (Netherlands)

    Riezebos-Brilman, A; de Mare, A; Bungener, L; Huckriede, A; Wischut, J; Daemen, T

    2006-01-01

    Background: Vectors derived from alphaviruses are gaining interest for their high transfection potency and strong immunogenicity. Objectives: After a brief introduction on alphaviruses and their vectors, an overview is given on current preclinical immunotherapy studies using vector systems based on

  20. Expression of human clotting factor Ⅸ mediated by recombinant lentiviral vector in cultured cells and hemophilia B mice

    Institute of Scientific and Technical Information of China (English)

    ZHU Huanzhang; CHEN Xiaoguang; LI Feng; GONG Juli; XUE Jinglun

    2003-01-01

    To explore the expression of human clotting factor Ⅸ (hFⅨ) cDNA in vitro and the feasibility of gene therapy for hemophilia B mice mediated by recombinant lentiviral vector, a recombinant hFⅨ lentiviral vector driven by ubiquitin-C promoter, FUXW, and by ABP liver specific promoter, FAXW, was constructed respectively. Recombinant lentivirus was harvested from 293T cells by calcium phosphate-mediated transient cotransfection of three plasmids (transgene vector, CMVΔR8.2, VSV-G). hFⅨ expression was detected in supernatant of 293T, BHK and L-02 cells infected with FUXW virus, whereas higher expression of hFⅨ levels (630 ng/106 cells/48 h) was detected only in L-02 cells infected with FAXW virus. Serum hFⅨ antigen was detected in all hemophilia B mice treated with FAXW virus by tail vein injection, an efficiency level of hFⅨ was observed (45 ng/mL, approximately 1% of normal human levels), the expression lasted for more than 60 d. The results indicated that HIV-based lentiviral vectors offer a promising approach to the gene therapy of hemophilia B.

  1. A set of vectors for introduction of antibiotic resistance genes by in vitro Cre-mediated recombination

    Directory of Open Access Journals (Sweden)

    Vassetzky Yegor S

    2008-12-01

    Full Text Available Abstract Background Introduction of new antibiotic resistance genes in the plasmids of interest is a frequent task in molecular cloning practice. Classical approaches involving digestion with restriction endonucleases and ligation are time-consuming. Findings We have created a set of insertion vectors (pINS carrying genes that provide resistance to various antibiotics (puromycin, blasticidin and G418 and containing a loxP site. Each vector (pINS-Puro, pINS-Blast or pINS-Neo contains either a chloramphenicol or a kanamycin resistance gene and is unable to replicate in most E. coli strains as it contains a conditional R6Kγ replication origin. Introduction of the antibiotic resistance genes into the vector of interest is achieved by Cre-mediated recombination between the replication-incompetent pINS and a replication-competent target vector. The recombination mix is then transformed into E. coli and selected by the resistance marker (kanamycin or chloramphenicol present in pINS, which allows to recover the recombinant plasmids with 100% efficiency. Conclusion Here we propose a simple strategy that allows to introduce various antibiotic-resistance genes into any plasmid containing a replication origin, an ampicillin resistance gene and a loxP site.

  2. A sensitive and rapid assay for homologous recombination in mosquito cells: impact of vector topology and implications for gene targeting

    Directory of Open Access Journals (Sweden)

    Zhao Yuguang

    2001-12-01

    Full Text Available Abstract Background Recent progress in insect transgenesis has been dramatic but existing transposon-based approaches are constrained by position effects and potential instability. Gene targeting would bring a number of benefits, however progress requires a better understanding of the mechanisms involved. Much can be learned in vitro since extrachromosomal recombination occurs at high frequency, facilitating the study of multiple events and the impact of structural changes among the recombining molecules. We have investigated homologous recombination in mosquito cells through restoration of luciferase activity from deleted substrates. The implications of this work for the construction of insect gene targeting vectors are discussed. Results We show that linear targeting vectors are significantly more efficient than circular ones and that recombination is stimulated by introducing double-strand breaks into, or near, the region of homology. Single-strand annealing represents a very efficient pathway but may not be feasible for targeting unbroken chromosomes. Using circular plasmids to mimic chromosomal targets, one-sided invasion appears to be the predominant pathway for homologous recombination. Non-homologous end joining reactions also occur and may be utilised in gene targeting if double-strand breaks are first introduced into the target site. Conclusions We describe a rapid, sensitive assay for extrachromosomal homologous recombination in mosquito cells. Variations in substrate topology suggest that single-strand annealing and one-sided invasion represent the predominant pathways, although non-homologous end joining reactions also occur. One-sided invasion of circular chromosomal mimics by linear vectors might therefore be used in vitro to investigate the design and efficiency of gene targeting strategies.

  3. Improving the safety of viral DNA vaccines: development of vectors containing both 5' and 3' homologous regulatory sequences from non-viral origin.

    Science.gov (United States)

    Martinez-Lopez, A; Encinas, P; García-Valtanen, P; Gomez-Casado, E; Coll, J M; Estepa, A

    2013-04-01

    Although some DNA vaccines have proved to be very efficient in field trials, their authorisation still remains limited to a few countries. This is in part due to safety issues because most of them contain viral regulatory sequences to driving the expression of the encoded antigen. This is the case of the only DNA vaccine against a fish rhabdovirus (a negative ssRNA virus), authorised in Canada, despite the important economic losses that these viruses cause to aquaculture all over the world. In an attempt to solve this problem and using as a model a non-authorised, but efficient DNA vaccine against the fish rhabdovirus, viral haemorrhagic septicaemia virus (VHSV), we developed a plasmid construction containing regulatory sequences exclusively from fish origin. The result was an "all-fish vector", named pJAC-G, containing 5' and 3' regulatory sequences of β-acting genes from carp and zebrafish, respectively. In vitro and in vivo, pJAC-G drove a successful expression of the VHSV glycoprotein G (G), the only antigen of the virus conferring in vivo protection. Furthermore, and by means of in vitro fusion assays, it was confirmed that G protein expressed from pJAC-G was fully functional. Altogether, these results suggest that DNA vaccines containing host-homologous gene regulatory sequences might be useful for developing safer DNA vaccines, while they also might be useful for basic studies.

  4. Intradermal delivery of recombinant vaccinia virus vector DIs induces gut-mucosal immunity.

    Science.gov (United States)

    Yoshino, N; Kanekiyo, M; Hagiwara, Y; Okamura, T; Someya, K; Matsuo, K; Ami, Y; Sato, S; Yamamoto, N; Honda, M

    2010-08-01

    Antigen-specific mucosal immunity is generally induced by the stimulation of inductive mucosal sites. In this study, we found that the replication-deficient vaccinia virus vector, DIs, generates antigen-specific mucosal immunity and systemic responses. Following intradermal injection of recombinant DIs expressing simian immunodeficiency virus gag (rDIsSIVgag), we observed increased levels of SIV p27-specific IgA and IgG antibodies in faecal extracts and plasma samples, and antibody-forming cells in the intestinal mucosa and spleen of C57BL/6 mice. Antibodies against p27 were not detected in nasal washes, saliva, and vaginal washes. The enhanced mucosal and systemic immunity persisted for 1 year of observation. Induction of Gag-specific IFN-gamma spot-forming CD8(+) T cells in the spleen, small intestinal intraepithelial lymphocytes, and submandibular lymph nodes was observed in the intradermally injected mice. Heat-inactivated rDIsSIVgag rarely induced antigen-specific humoral and T-helper immunity. Moreover, rDIsSIVgag was detected in MHC class II IA antigen-positive (IA(+)) cells at the injection site. Consequently, intradermal delivery of rDIs effectively induces antigen-specific humoral and cellular immunity in gut-mucosal tissues of mice. Our data suggest that intradermal injection of an rDIs vaccine may be useful against mucosally transmitted pathogens.

  5. Characterization of Recombinant Thermococcus kodakaraensis (KOD) DNA Polymerases Produced Using Silkworm-Baculovirus Expression Vector System

    KAUST Repository

    Yamashita, Mami

    2017-05-08

    The KOD DNA polymerase from Thermococcus kodakarensis (Tkod-Pol) has been preferred for PCR due to its rapid elongation rate, extreme thermostability and outstanding fidelity. Here in this study, we utilized silkworm-baculovirus expression vector system (silkworm-BEVS) to express the recombinant Tkod-Pol (rKOD) with N-terminal (rKOD-N) or C-terminal (rKOD-C) tandem fusion tags. By using BEVS, we produced functional rKODs with satisfactory yields, about 1.1 mg/larva for rKOD-N and 0.25 mg/larva for rKOD-C, respectively. Interestingly, we found that rKOD-C shows higher thermostability at 95 °C than that of rKOD-N, while that rKOD-N is significantly unstable after exposing to long period of heat-shock. We also assessed the polymerase activity as well as the fidelity of purified rKODs under various conditions. Compared with commercially available rKOD, which is expressed in E. coli expression system, rKOD-C exhibited almost the same PCR performance as the commercial rKOD did, while rKOD-N did lower performance. Taken together, our results suggested that silkworm-BEVS can be used to express and purify efficient rKOD in a commercial way.

  6. Alternative purification method for recombinant measles viral nucleoprotein expressed in insect cells by ion-exchange chromatography.

    Science.gov (United States)

    Lee, Han Saem; Kim, You-Jin; Yang, Jeongsun; Yoon, Hee Sook; Kim, Seung Tae; Kim, Kisoon

    2014-03-01

    Recombinant measles virus nucleoproteins (rMeV N) and fusion (F) proteins were characterized as major antigenic proteins expressed in insect cells mediated by recombinant baculoviruses (rBVs). Band intensities were analyzed by Western blotting to recognize IgG and IgM antibodies against the rMeV N and F proteins in human sera and cerebrospinal fluids (CSFs) from patients with measles infections. Positive results from the blots using the rMeV N were consistent with the results of enzyme-linked immunosorbent assays (ELISAs) in which whole viral proteins were used as antigens. Human sera and CSFs reacted more strongly with the rMeV N than with the rMeV F proteins prepared in an identical expression system. For efficient and reliable purification, ion-exchange chromatography using Source Q anion resin was applied, and high-purity rMeV N protein was harvested. To characterize the similarity with the native viral protein to purified N protein, structural mimicry of purified recombinant proteins with intact rMeV N was shown through transmission electron microscopy, and the truncation and the phosphorylation status of the expressed protein were analyzed. These results suggest that the rMeV N purified by ion-exchange chromatography has features similar to those of naïve N including a self-assembled structure, phosphorylation and antigenic function. Thus, these expression and purification methods can be applied to the large-scale production of the rMeV N, which is essential for the development of new diagnostic tools and vaccines for acute and chronic MeV infections.

  7. Effects of NV gene knock-out recombinant viral hemorrhagic septicemia virus (VHSV) on Mx gene expression in Epithelioma papulosum cyprini (EPC) cells and olive flounder (Paralichthys olivaceus).

    Science.gov (United States)

    Kim, Min Sun; Kim, Ki Hong

    2012-03-01

    To determine whether the NV gene of viral hemorrhagic septicemia virus (VHSV) is related to the type I interferon response of hosts, expression of Mx gene in Epithelioma papulosum cyprini (EPC) cells and in olive flounder (Paralichthys olivaceus) in response to infection with either wild-type VHSV or recombinant VHSVs (rVHSV-ΔNV-EGFP and rVHSV-wild) was investigated. A reporter vector was constructed for measuring Mx gene expression using olive flounder Mx promoter, in which the reporter Metridia luciferase was designed to be excreted to culture medium to facilitate measurement. The highest increase of luciferase activity was detected from supernatant of cells infected with rVHSV-ΔNV-EGFP. In contrast cells infected with wild-type VHSV showed a slight increase of the luciferase activity. Interestingly, cells infected with rVHSV-wild that has artificially changed nucleotides just before and after the NV gene ORF, also showed highly increased luciferase activity, but the increased amplitude was lower than that by rVHSV-ΔNV-EGFP. These results strongly suggest that the NV protein of VHSV plays an important role in suppressing interferon response in host cells, which provides a condition for the viruses to efficiently proliferate in host cells. In an in vivo experiment, the Mx gene expression in olive flounder challenged with the rVHSV-ΔNV-EGFP was clearly higher than fish challenged with rVHSV-wild or wild-type VHSV, suggesting that lacking of the NV gene in the genome of rVHSV-ΔNV-EGFP brought to strong interferon response that subsequently inhibit viral replication in fish.

  8. Development of next generation adeno-associated viral vectors capable of selective tropism and efficient gene delivery.

    Science.gov (United States)

    Zhang, Chuanling; Yao, Tianzhuo; Zheng, Yongxiang; Li, Zhongjun; Zhang, Qiang; Zhang, Lihe; Zhou, Demin

    2016-02-01

    Virus-based nanoparticles have shown promise as vehicles for delivering therapeutic genes. However, the rational design of viral vectors that enable selective tropism towards particular types of cells and tissues remains challenging. Here, we explored structural-functional relationships of the adeno-associated virus 2 (AAV2) vector by expanding its genetic code during production. As a proof-of-principle, an azide moiety was strategically displayed on the vector capsid as a bioorthogonal chemical reporter. Upon bioorthogonal conjugation of AAV2 with fluorophores and cyclic arginyl-glycyl-aspartic acid ligands at certain modifiable sites, we characterized in vitro and in vivo AAV2 movement and enhanced tropism selectivity towards integrin-expressing tumor cells. Targeting AAV2 vectors resulted in selective killing of U87 glioblastoma cells and derived xenografts via the herpes simplex virus suicide gene thymidine kinase, with the potency of ganciclovir being increased by 25-fold. Our results demonstrated successful rational modification of AAV2 as a targeting delivery vehicle, establishing a facile platform for precision engineering of virus-based nanoparticles in basic research and therapeutic applications.

  9. Gene therapy for pathological scar with hepatocyte growth factor mediated by recombinant adenovirus vector

    Institute of Scientific and Technical Information of China (English)

    哈小琴; 苑宾; 李元敏; 劳妙芬; 吴祖泽

    2003-01-01

    A complementary DNA (cDNA) encoding human hepatocyte growth factor wasintroduced into a replication-defective type 5 adenovirus (lacking E1, E3 domains) vector by homologous recombination of intracellular plasmid DNA, thus a recombinant vector containing HGF (Ad-HGF) was obtained. Ad-HGF and Ad-GFP (adenovirus vector carrying green fluorescence protein gene) were expanded in 293 cells and purified by cesium chloride gradient centrifugation for large-scale preparation, then were infected to the primarily cultured scar fibroblast of rabbit ear to observe the transfer efficiency and expression level of HGF in vitro. To evaluate the effect of Ad-HGF on established scar Ad-HGF solution was injected into excessively formed scar, which bears some clinical and histologic similarities tohuman hypertrophic scars. The results showed that: (i) the transfer efficiency was 36.8%±14.1% on day 3 in primarily cultured scar fibroblasts treated with Ad-GFP and lasted more than 20 d; (ii) high-level expression of HGF protein was detected by means of ELISA in supernatant of scar fibroblasts treated with Ad-HGF,the amount of expression was 76 ng/4.0×105 cells on day 3; (iii) on day 32 after a single intradermal injection of Ad-HGF at different doses (8.6×109 pfu, 8.6×108 pfu, 8.6×107 pfu, 8.6×106 pfu) per scar, most of the scars in the former two dose groups were dramatically flattened, some were even similar to that ofthe normal skin. The value of HI (hypertrophic index) showed that there was a therapeutic effect of Ad-HGF on scars at the dose of 109 pfu and 108 pfu. Whereasno therapeutic effects were seen at lower dose (107 pfu and 106 pfu of Ad-HGF) groups. In addition, clusters of hair were observed to different extent on healed wound treated with Ad-HGF. Histopathologic examination revealed that in most healed wounds of Ad-HGF treated group, the dermal layer was thinner, the amount of fibrous tissue was much fewer, and hair follicles growth and sebaceous glands were observed

  10. Vectores

    OpenAIRE

    2016-01-01

    Documento que contiene la explicación sobre las temáticas de Sistemas coordenados, Cantidades vectoriales y escalares, Algunas propiedades de los vectores, Componentes de un vector y vectores unitarios

  11. A concept of eliminating nonhomologous recombination for scalable and safe AAV vector generation for human gene therapy.

    Science.gov (United States)

    Dong, Biao; Moore, Andrea R; Dai, Jihong; Roberts, Sean; Chu, Kirk; Kapranov, Philipp; Moss, Bernard; Xiao, Weidong

    2013-07-01

    Scalable and efficient production of high-quality recombinant adeno-associated virus (rAAV) for gene therapy remains a challenge despite recent clinical successes. We developed a new strategy for scalable and efficient rAAV production by sequestering the AAV helper genes and the rAAV vector DNA in two different subcellular compartments, made possible by using cytoplasmic vaccinia virus as a carrier for the AAV helper genes. For the first time, the contamination of replication-competent AAV particles (rcAAV) can be completely eliminated in theory by avoiding ubiquitous nonhomologous recombination. Vector DNA can be integrated into the host genomes or delivered by a nuclear targeting vector such as adenovirus. In suspension HeLa cells, the achieved vector yield per cell is similar to that from traditional triple-plasmid transfection method. The rcAAV contamination was undetectable at the limit of our assay. Furthermore, this new concept can be used not only for production of rAAV, but also for other DNA vectors.

  12. Transgene optimization, immunogenicity and in vitro efficacy of viral vectored vaccines expressing two alleles of Plasmodium falciparum AMA1.

    OpenAIRE

    Sumi Biswas; Dicks, Matthew D. J.; Carole A Long; Remarque, Edmond J; Loredana Siani; Stefano Colloca; Cottingham, Matthew G; Holder, Anthony A.; Gilbert, Sarah C.; Hill, Adrian V.S.; Draper, Simon J

    2011-01-01

    BACKGROUND: Apical membrane antigen 1 (AMA1) is a leading candidate vaccine antigen against blood-stage malaria, although to date numerous clinical trials using mainly protein-in-adjuvant vaccines have shown limited success. Here we describe the pre-clinical development and optimization of recombinant human and simian adenoviral (AdHu5 and ChAd63) and orthopoxviral (MVA) vectors encoding transgene inserts for Plasmodium falciparum AMA1 (PfAMA1). METHODOLOGY/PRINCIPAL FINDINGS: AdHu5-MVA prime...

  13. Safety considerations in vector development.

    Science.gov (United States)

    Kappes, J C; Wu, X

    2001-11-01

    The inadvertent production of replication competent retrovirus (RCR) constitutes the principal safety concern for the use of lentiviral vectors in human clinical protocols. Because of limitations in animal models to evaluate lentiviral vectors for their potential to recombine and induce disease, the vector design itself should ensure against the emergence of RCR in vivo. Issues related to RCR generation and one approach to dealing with this problem are discussed in this chapter. To assess the risk of generating RCR, a highly sensitive biological assay was developed to specifically detect vector recombination in transduced cells. Analysis of lentiviral vector stocks has shown that recombination occurs during reverse transcription in primary target cells. Rejoining of viral protein-coding sequences of the packaging construct and cis-acting sequences of the vector was demonstrated to generate env-minus recombinants (LTR-gag-pol-LTR). Mobilization of recombinant lentiviral genomes was also demonstrated but was dependent on pseudotyping of the vector core with an exogenous envelope protein. 5' sequence analysis has demonstrated that recombinants consist of U3, R, U5, and the psi packaging signal joined with an open gag coding region. Analysis of the 3' end has mapped the point of vector recombination to the poly(A) tract of the packaging construct's mRNA. The state-of-the-art third generation packaging construct and SIN vector also have been shown to generate env-minus proviral recombinants capable of mobilizing retroviral DNA when pseudotyped with an exogenous envelope protein. A new class of HIV-based vector (trans-vector) was recently developed that splits the gag-pol component of the packaging construct into two parts: one that expresses Gag/Gag-Pro and another that expresses Pol (RT and IN) fused with Vpr. Unlike other lentiviral vectors, the trans-vector has not been shown to form recombinants capable of DNA mobilization. These results indicate the trans-vector

  14. Successful disabling of the 5' UTR of HCV using adeno-associated viral vectors to deliver modular multimeric primary microRNA mimics.

    Science.gov (United States)

    Bourhill, Tarryn; Arbuthnot, Patrick; Ely, Abdullah

    2016-09-01

    Chronic hepatitis C virus (HCV) infection is a major health concern and is strongly associated with cirrhosis, hepatocellular carcinoma and liver-related mortality. The HCV genome is the template for both protein translation and viral replication and, being RNA, is amenable to direct genetic silencing by RNA interference (RNAi). HCV is a highly mutable virus and is capable of escaping RNAi-mediated silencing. This has highlighted the importance of developing RNAi-based therapy that simultaneously targets multiple regions of the HCV genome. To develop a multi-targeting RNAi activator, a novel approach for the generation of anti-HCV gene therapy was investigated. Five artificial primary miRNA (pri-miR) were each designed to mimic the naturally occurring monomeric pri-miR-31. Potent knockdown of an HCV reporter was seen with four of the five constructs and were processed according to the intended design. The design of the individual pri-miR mimics enabled the modular assembly into multimeric mimics of any possible conformation. Consequently the four potent pri-miR mimics were used to generate polycistronic cassettes, which showed impressive silencing of an HCV target. To further their application as a gene therapy, recombinant adeno-associated viral (rAAV) vectors that express the polycistronic pri-miR mimics were generated. All AAV-delivered anti-HCV pri-miR mimics significantly knocked down the expression of an HCV target and showed inhibition of HCV replicon replication. Here we describe a protocol for the generation of therapeutic rAAVs that express modular polycistronic pri-miR cassettes allowing for rapid alteration and generation of tailored therapeutic constructs against HCV.

  15. Development and use of an efficient DNA-based viral gene silencing vector for soybean.

    Science.gov (United States)

    Zhang, Chunquan; Yang, Chunling; Whitham, Steven A; Hill, John H

    2009-02-01

    Virus-induced gene silencing (VIGS) is increasingly being used as a reverse genetics tool to study functions of specific plant genes. It is especially useful for plants, such as soybean, that are recalcitrant to transformation. Previously, Bean pod mottle virus (BPMV) was shown to be an effective VIGS vector for soybean. However, the reported BPMV vector requires in vitro RNA transcription and inoculation, which is not reliable or amenable to high-throughput applications. To increase the efficiency of the BPMV vector for soybean functional genomics, a DNA-based version was developed. Reported here is the construction of a Cauliflower mosaic virus 35S promoter-driven BPMV vector that is efficient for the study of soybean gene function. The selection of a mild rather than a severe BPMV strain greatly reduced the symptom interference caused by virus infection. The DNA-based BPMV vector was used to silence soybean homologues of genes involved in plant defense, translation, and the cytoskeleton in shoots and in roots. VIGS of the Actin gene resulted in reduced numbers of Soybean mosaic virus infection foci. The results demonstrate the utility of this new vector as an efficient tool for a wide range of applications for soybean functional genomics.

  16. RDNA cloning vector pVE1, deletion and hybrid mutants and recombinant derivatives thereof products and processes

    Energy Technology Data Exchange (ETDEWEB)

    MacNeil, T.; Gibbons, P.H.

    1987-10-27

    This patent describes novel plasmid pVE1, deletion mutants thereof, recombinant derivatives thereof, which is the same as the genome or nucleic acid of such plasmids and derivatives of such genome, which are useful as recombinant DNA cloning vectors into host organisms, such as bacteria, for example, Streptomyces avermitilis. Portions of such plasmid genome are additionally useful as adjuncts in recombinant DNA cloning procedures, for examples: 1. to permit the maintenance of cloned DNA in the host, either in an integrated state or as an autonomous element; 2. to serve as promoters for increasing expression of endogenous or foreign genes wherein the promoters are ligated to such genes or otherwise serve as promoters; and 3. to serve as regulatory elements for achieving control over endogenous and foreign gene expression. As cloning vectors, pVE1 its deletion mutants, and other derivatives serve for the amplification and transfer of DNA sequences (genes) coding for useful functions. Such modified cloning vectors are introduced into the recipient organism by conjugation or transformation; wherein the hybrid DNA functions in an integrated mode and/or in plasmid mode.

  17. A vector system for ABC transporter-mediated secretion and purification of recombinant proteins in Pseudomonas species.

    Science.gov (United States)

    Ryu, Jaewook; Lee, Ukjin; Park, Jiye; Yoo, Do-Hyun; Ahn, Jung Hoon

    2015-03-01

    Pseudomonas fluorescens is an efficient platform for recombinant protein production. P. fluorescens has an ABC transporter secreting endogenous thermostable lipase (TliA) and protease, which can be exploited to transport recombinant proteins across the cell membrane. In this study, the expression vector pDART was constructed by inserting tliDEF, genes encoding the ABC transporter, along with the construct of the lipase ABC transporter recognition domain (LARD), into pDSK519, a widely used shuttle vector. When the gene for the target protein was inserted into the vector, the C-terminally fused LARD allowed it to be secreted through the ABC transporter into the extracellular medium. After secretion of the fused target protein, the LARD containing a hydrophobic C terminus enabled its purification through hydrophobic interaction chromatography (HIC) using a methyl-Sepharose column. Alkaline phosphatase (AP) and green fluorescent protein (GFP) were used to validate the expression, export, and purification of target proteins by the pDART system. Both proteins were secreted into the extracellular medium in P. fluorescens. In particular, AP was secreted in several Pseudomonas species with its enzymatic activity in extracellular media. Furthermore, purification of the target protein using HIC yielded some degree of AP and GFP purification, where AP was purified to almost a single product. The pDART system will provide greater convenience for the secretory production and purification of recombinant proteins in Gram-negative bacteria, such as Pseudomonas species.

  18. Targeted Genome Editing by Recombinant Adeno-Associated Virus (rAAV) Vectors for Generating Genetically Modified Pigs

    Institute of Scientific and Technical Information of China (English)

    Yonglun Luo; Emil Kofod-Olsen; Rikke Christensen; Charlotte Brandt S(φ)rensen; Lars Bolund

    2012-01-01

    Recombinant adeno-associated virus (rAAV) vectors have been extensively used for experimental gene therapy of inherited human diseases.Several advantages,such as simple vector construction,high targeting frequency by homologous recombination,and applicability to many cell types,make rAAV an attractive approach for targeted genome editing.Combined with cloning by somatic cell nuclear transfer (SCNT),this technology has recently been successfully adapted to generate gene-targeted pigs as models for cystic fibrosis,hereditary tyrosinemia type 1,and breast cancer.This review summarizes the development of rAAV for targeted genome editing in mammalian cells and provides strategies for enhancing the rAAV-mediated targeting frequency by homologous recombination.We discuss current development and application of the rAAV vectors for targeted genome editing in porcine primary fibroblasts,which are subsequently used as donor cells for SCNT to generate cloned genetically designed pigs and provide positive perspectives for the generation of gene-targeted pigs with rAAV in the future.

  19. Construction of Antibacterial Peptide CecropinB Eukaryotic Recombinant Vector and Its Expression in Dairy Goat Mammary Gland Epithelial Cells

    Institute of Scientific and Technical Information of China (English)

    GAO Xuejun; TONG Huili; YIN Deyun; ZHANG Li

    2008-01-01

    To investigate the expression of antibacterial peptide CecropinB eDNA in dairy goat mammary gland epithelial cells, the CecropinB gene was eloned and was inserted into a eukaryotic vector pECFP-Cl to construct the recombinant plasmid pECFP-B by genetic engineering technique. Recombinant plasmid pECFP-B was transfected into dairy goat mammary gland epithelial to detect the bactericidal activity of CeeropinB. The expression of CecropinB was also detected. The result of RT-PCR demonstrated CecropinB gene was expressed in transfeeted cells. CecropinB recombinant plasmid DNA was injected into udders and CecropinB was expressed in mammary gland, exhibiting bactericidal activity to Staphylococcus aureus in vivo experiments.

  20. RNA viral vectors for improved Agrobacterium-mediated transient expression of heterologous proteins in Nicotiana benthamiana cell suspensions and hairy roots

    Directory of Open Access Journals (Sweden)

    Larsen Jeffrey S

    2012-05-01

    Full Text Available Abstract Background Plant cell suspensions and hairy root cultures represent scalable protein expression platforms. Low protein product titers have thus far limited the application of transient protein expression in these hosts. The objective of this work was to overcome this limitation by harnessing A. tumefaciens to deliver replicating and non-replicating RNA viral vectors in plant tissue co-cultures. Results Replicating vectors derived from Potato virus X (PVX and Tobacco rattle virus (TRV were modified to contain the reporter gene β-glucuronidase (GUS with a plant intron to prevent bacterial expression. In cell suspensions, a minimal PVX vector retaining only the viral RNA polymerase gene yielded 6.6-fold more GUS than an analogous full-length PVX vector. Transient co-expression of the minimal PVX vector with P19 of Tomato bushy stunt virus or HC-Pro of Tobacco etch virus to suppress post-transcriptional gene silencing increased GUS expression by 44 and 83%, respectively. A non-replicating vector containing a leader sequence from Cowpea mosaic virus (CPMV-HT modified for enhanced translation led to 70% higher transient GUS expression than a control treatment. In hairy roots, a TRV vector capable of systemic movement increased GUS accumulation by 150-fold relative to the analogous PVX vector. Histochemical staining for GUS in TRV-infected hairy roots revealed the capacity for achieving even higher productivity per unit biomass. Conclusions For the first time, replicating PVX vectors and a non-replicating CPMV-HT vector were successfully applied toward transient heterologous protein expression in cell suspensions. A replicating TRV vector achieved transient GUS expression levels in hairy roots more than an order of magnitude higher than the highest level previously reported with a viral vector delivered by A. tumefaciens.

  1. RNA viral vectors for improved Agrobacterium-mediated transient expression of heterologous proteins in Nicotiana benthamiana cell suspensions and hairy roots

    Science.gov (United States)

    2012-01-01

    Background Plant cell suspensions and hairy root cultures represent scalable protein expression platforms. Low protein product titers have thus far limited the application of transient protein expression in these hosts. The objective of this work was to overcome this limitation by harnessing A. tumefaciens to deliver replicating and non-replicating RNA viral vectors in plant tissue co-cultures. Results Replicating vectors derived from Potato virus X (PVX) and Tobacco rattle virus (TRV) were modified to contain the reporter gene β-glucuronidase (GUS) with a plant intron to prevent bacterial expression. In cell suspensions, a minimal PVX vector retaining only the viral RNA polymerase gene yielded 6.6-fold more GUS than an analogous full-length PVX vector. Transient co-expression of the minimal PVX vector with P19 of Tomato bushy stunt virus or HC-Pro of Tobacco etch virus to suppress post-transcriptional gene silencing increased GUS expression by 44 and 83%, respectively. A non-replicating vector containing a leader sequence from Cowpea mosaic virus (CPMV-HT) modified for enhanced translation led to 70% higher transient GUS expression than a control treatment. In hairy roots, a TRV vector capable of systemic movement increased GUS accumulation by 150-fold relative to the analogous PVX vector. Histochemical staining for GUS in TRV-infected hairy roots revealed the capacity for achieving even higher productivity per unit biomass. Conclusions For the first time, replicating PVX vectors and a non-replicating CPMV-HT vector were successfully applied toward transient heterologous protein expression in cell suspensions. A replicating TRV vector achieved transient GUS expression levels in hairy roots more than an order of magnitude higher than the highest level previously reported with a viral vector delivered by A. tumefaciens. PMID:22559055

  2. Design and construction of improved new vectors for Zymomonas mobilis recombinants.

    Science.gov (United States)

    Dong, Hong-Wei; Bao, Jie; Ryu, Dewey D Y; Zhong, Jian-Jiang

    2011-07-01

    Zymomonas mobilis is a very important gram-negative bacterium having a potential application to simultaneous co-production of biofuel and other high value-added products through biorefinery process technology development. Up to now, pLOI193 has been used as the plasmid of choice for Z. mobilis strains. However, its application has been limited due to its relatively low transformation efficiency, a large plasmid size (13.4 kb), and limited choice of cloning sites for gene manipulations. Some of these limitations can be overcome by the newly designed and constructed plasmid pHW20a, which provides significantly higher transformation efficiency (about two orders of magnitude greater), better stability (for at least 120 generation times), and an ease of gene manipulations. The pHW20a contains three complete cis-acting genes (repA, repB, and repC) encoding the Rep proteins for primosome formation. It has the origin of replication (oriV) to ensure replication in gram-negative bacteria, two mob genes that enhances transformation efficiency, a screening marker (lacZα), expanded multiple cloning sites (MCS) that enables easy gene manipulation, and the tetracycline resistance gene (tc(r) ). The utility of screening marker, lacZα with MCS, was confirmed by the blue-white screening test. Several examples of applications of gene expression in Z. mobilis ZM4 have been demonstrated in this article by using several new pHW20a-derived plasmids and expressing the homologous genes (gfo and ppc) and the heterologous genes (bglA, mdh, and fdh1). The results show that pHW20a is a very useful new vector for construction of new Z. mobilis recombinant strains that will enable simultaneous co-production of biofuel and high value added products.

  3. Preclinical characterization of a recombinant adeno-associated virus type 1-pseudotyped vector demonstrates dose-dependent injection site inflammation and dissemination of vector genomes to distant sites.

    Science.gov (United States)

    Flotte, Terence R; Conlon, Thomas J; Poirier, Amy; Campbell-Thompson, Martha; Byrne, Barry J

    2007-03-01

    To translate the potential advantages of recombinant adeno-associated virus type 1 (rAAV1) vectors into a clinical application for muscle-directed gene therapy for alpha1 -antitrypsin (AAT) deficiency, we performed safety studies in 170 C57BL/6 mice and 26 New Zealand White rabbits. A mouse toxicology study included 8 cohorts of 10 mice each (5 per sex). Mice were killed either 21 or 90 days after intramuscular injection of doses ranging up to 1x10(13)vector genomes (VG), equivalent to 4 x 10(14)VG/kg. A mouse biodistribution study was performed in 5 cohorts of 10 mice, receiving intramuscular injections at the same doses; as well as in a lower dose cohort (3 x 10(8) VG; equivalent to 1.2 x 10(10)VG/kg); and in 4 other cohorts (excluding the vehicle control) injected with identical doses intravenously. Finally, biodistribution was examined in rabbits, with serial collection of blood and semen, as well as terminal tissue collection. Two significant findings were present, both of which were dose dependent. First, inflammatory cell infiltrates were detected at the site of injection 21, 60, or 90 days after intramuscular injection of 1 x 10(13)VG. This was not associated with loss of transgene expression. Second, vector DNA sequences were detected in most animals, levels being highest with the highest doses and earliest time points. Vector DNA was also present in liver, spleen, kidneys, and a number of other organs, including the gonads of animals receiving the highest dose. Likewise, vector DNA was present in the semen of male rabbits at higher doses. The copy number of vector DNA in the blood and semen declined over time throughout the study. These two dose-dependent findings have served to guide to the design of a phase 1 human trial of rAAV1-AAT.

  4. Curative effect of transplantation of mesenchymal stem cells transfected with recombinant lentiviral vectors carrying brain-derived neurotrophic factor gene on intracerebral hemorrhage in rats

    Institute of Scientific and Technical Information of China (English)

    任瑞芳

    2013-01-01

    Objective To observe the curative effect of transplantation of mesenchymal stem cells(MSCs) transfected with recombinant lentiviral vectors carrying brain-derived neurotrophic factor(BDNF) gene on intracerebral

  5. Non-essential viral proteins of orbiviruses are essential for vector-borne spread by midges

    Science.gov (United States)

    Members of the Reoviridae family are non-enveloped multi-layered viruses with a double stranded RNA genome consisting of 9-12 genome segments. The Orbivirus genus contains vector borne virus species with 10 genome segments such as bluetongue virus (BTV) with about 30 serotypes, and African horse sic...

  6. Viral vector-mediated gene transfer in fundamental and applied cardiovascular research

    NARCIS (Netherlands)

    Swildens, Jim

    2012-01-01

    To treat various cardiac diseases, modification of gene expression for the purpose of increased or decreased expression of a particular gene, is regarded as a potential therapy. As a vehicle to introduce the gene of choice into the heart cell, virus vectors have given the most promising results. Thi

  7. An MRI-visible non-viral vector for targeted Bcl-2 siRNA delivery to neuroblastoma

    Directory of Open Access Journals (Sweden)

    Shen M

    2012-07-01

    Full Text Available Min Shen,1,* Faming Gong,3,* Pengfei Pang,1,* Kangshun Zhu,1 Xiaochun Meng,1 Chun Wu,1 Jin Wang,1 Hong Shan,1,2 Xintao Shuai3,41Molecular Imaging Lab, Department of Radiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China; 2Institute of Intervention Radiology, Sun Yat-sen University, Guangzhou, China; 3PCFM Lab of Ministry of Education, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou, China; 4Center of Biomedical Engineering, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China*These authors contributed equally to this workAbstract: Polyethylene glycol-grafted polyethylenimine (PEG-g-PEI which was functionalized with a neuroblastoma cell-specific ligand, the GD2 single chain antibody (scAbGD2, was synthesized in order to effectively deliver Bcl-2 siRNA into neuroblastoma cells. This polymer was complexed first with superparamagnetic iron oxide nanoparticle (SPION to get a MRI-visible targeted non-viral vector (scAbGD2-PEG-g-PEI-SPION and then with Bcl-2 siRNA to form nanoparticles showing low cytotoxicity. The targeting capacity of scAbGD2-PEG-g-PEI-SPION was successfully verified in vivo and in vitro by magnetic resonance imaging. The single chain antibody encoded targeted polyplex was more effective in transferring Bcl-2 siRNA than the nontargeting one in SK-N-SH cells, a human neuroblastoma cell line, resulting in a 46.34% inhibition in the expression of Bcl-2 mRNA. Consequently, a high level of cell apoptosis up to 50.76% and a significant suppression of tumor growth were achieved, which indicates that scAbGD2-PEG-g-PEI-SPION is a promising magnetic resonance imaging-visible non-viral vector for targeted neuroblastoma siRNA therapy and diagnosis.Keywords: tumor targeting, GD2, non-viral vector, Bcl-2 small interfering RNA, magnetic resonance imaging

  8. Risk Assessment of Synergism and Recombination on the Transgenic Plants Containing Viral Movement Protein and Replicase Genes

    Institute of Scientific and Technical Information of China (English)

    NIU Yan-bing; LI Gui-xin; WEN Rui; ZHOU Xue-ping

    2003-01-01

    The transgenic tobacco plants transformed with movement protein gene of Tomato mosaic virus (ToMV) or Tobacco mosaic virus (TMV) and partial replicase gene of Cucumber mosaic virus (CMV) P1 isolate (CMV-P1), were inoculated with Potato virus X, Potato virus Y, TMV and CMV isolate RB (CMVRB), respectively. Symptom observation showed there were no symptom differences in transgenic tobacco plants as compared with those in non-transgenic tobacco plants. ELISA also illustrated that the virus concentrations in the transgenic plants were similar to those in non-transgenic plants, indicating that no synergism is found in these plants. The transgenic tobacco plants expressing movement protein gene of ToMV or partial replicase gene of CMV-P1 were inoculated with TMV and CMV-RB, respectively. The local or systemic infected leaves were then used for elucidation of the possible virus recombination in transgenic plants with biological infectivity test, ELISA and immuno-capture RT-PCR. Within 16 months, no recombination was found between transformed genes and inoculated virus genomes. The research provides fundamental data for understanding of the possible risk of the transgenic plants expressing viral sequences.

  9. Oral immunization of olive flounder (Paralichthys olivaceus) with recombinant live viral hemorrhagic septicemia virus (VHSV) induces protection against VHSV infection.

    Science.gov (United States)

    Kim, Min Sun; Kim, Dong Soo; Kim, Ki Hong

    2011-08-01

    A recombinant viral hemorrhagic septicemia virus (rVHSV-ΔNV-EGFP) that has enhanced green fluorescent protein (EGFP) gene instead of NV gene was previously generated using reverse genetics technology. In this study, potential of the rVHSV-ΔNV-EGFP to be used as a live oral vaccine candidate was assessed. The presence of the recombinant virus in internal organs of orally administered olive flounder (Paralichthys olivaceus) was analyzed by semi-quantitative RT-PCR. Although the recombinant VHSV-specific band was detected only when the number of PCR cycle was increased to 35, the band was detected from internal organs, such as kidney, spleen, and liver of fish that were reared at either 15 °C or 20 °C till even 20 days, suggesting that a few orally administered rVHSV-ΔNV-EGFP might be transported to internal organs, and might keep weak replication ability in the organs. VHSV-neutralizing activity was induced by oral immunization of olive flounder with the NV gene knock-out recombinant VHSV not only in skin and intestinal mucus but also in serum, suggesting that mucosal and systemic adaptive immune responses were elicited by oral immunization. In challenge experiment, groups of fish immunized with 10⁴, 10⁵, and 2 × 10⁵ PFU of rVHSV-ΔNV-EGFP/fish showed 25%, 50%, and 70% of relative percent survival (RPS), respectively. The RPSs were elevated to 60%, 75%, and 90% by a boost immunization in fish boost immunized with 10⁴, 10⁵, and 2 × 10⁵ PFU of rVHSV-ΔNV-EGFP, respectively. The cumulative mortality of fish in the control groups was 100%. Conclusionly, the present results demonstrate that the NV gene knock-out recombinant VHSV administered orally to olive flounder can induce dose- and boosting-dependent VHSV-neutralizing antibody in mucus and serum, and can provide a high protection in olive flounder against a virulent VHSV challenge.

  10. Characterization of Adeno-Associated Viral Vector-Mediated Human Factor VIII Gene Therapy in Hemophilia A Mice.

    Science.gov (United States)

    Greig, Jenny A; Wang, Qiang; Reicherter, Amanda L; Chen, Shu-Jen; Hanlon, Alexandra L; Tipper, Christopher H; Clark, K Reed; Wadsworth, Samuel; Wang, Lili; Wilson, James M

    2017-05-01

    Adeno-associated viral (AAV) vectors are promising vehicles for hemophilia gene therapy, with favorable clinical trial data seen in the treatment of hemophilia B. In an effort to optimize the expression of human coagulation factor VIII (hFVIII) for the treatment of hemophilia A, an extensive study was performed with numerous combinations of liver-specific promoter and enhancer elements with a codon-optimized hFVIII transgene. After generating 42 variants of three reduced-size promoters and three small enhancers, transgene cassettes were packaged within a single AAV capsid, AAVrh10, to eliminate performance differences due to the capsid type. Each hFVIII vector was administered to FVIII knockout (KO) mice at a dose of 10(10) genome copies (GC) per mouse. Criteria for distinguishing the performance of the different enhancer/promoter combinations were established prior to the initiation of the studies. These criteria included prominently the level of hFVIII activity (0.12-2.12 IU/mL) and the pattern of development of anti-hFVIII antibodies. In order to evaluate the impact of capsid on hFVIII expression and antibody formation, one of the enhancer and promoter combinations that exhibited high hFVIII immunogenicity was evaluated using AAV8, AAV9, AAVrh10, AAVhu37, and AAVrh64R1 capsids. The capsids subdivided into two groups: those that generated anti-hFVIII antibodies in ≤20% of mice (AAV8 and AAV9), and those that generated anti-hFVIII antibodies in >20% of mice (AAVrh10, AAVhu37, and AAVrh64R1). The results of this study, which entailed extensive vector optimization and in vivo testing, demonstrate the significant impact that transcriptional control elements and capsid can have on vector performance.

  11. Viral Delivery of dsRNA for Control of Insect Agricultural Pests and Vectors of Human Disease: Prospects and Challenges

    Science.gov (United States)

    Kolliopoulou, Anna; Taning, Clauvis N. T.; Smagghe, Guy; Swevers, Luc

    2017-01-01

    RNAi is applied as a new and safe method for pest control in agriculture but efficiency and specificity of delivery of dsRNA trigger remains a critical issue. Various agents have been proposed to augment dsRNA delivery, such as engineered micro-organisms and synthetic nanoparticles, but the use of viruses has received relatively little attention. Here we present a critical view of the potential of the use of recombinant viruses for efficient and specific delivery of dsRNA. First of all, it requires the availability of plasmid-based reverse genetics systems for virus production, of which an overview is presented. For RNA viruses, their application seems to be straightforward since dsRNA is produced as an intermediate molecule during viral replication, but DNA viruses also have potential through the production of RNA hairpins after transcription. However, application of recombinant virus for dsRNA delivery may not be straightforward in many cases, since viruses can encode RNAi suppressors, and virus-induced silencing effects can be determined by the properties of the encoded RNAi suppressor. An alternative is virus-like particles that retain the efficiency and specificity determinants of natural virions but have encapsidated non-replicating RNA. Finally, the use of viruses raises important safety issues which need to be addressed before application can proceed. PMID:28659820

  12. Targeting of breast metastases using a viral gene vector with tumour-selective transcription.

    LENUS (Irish Health Repository)

    Rajendran, Simon

    2012-01-31

    BACKGROUND: Adeno-associated virus (AAV) vectors have significant potential as gene delivery vectors for cancer gene therapy. However, broad AAV2 tissue tropism results in nonspecific gene expression. MATERIALS AND METHODS: We investigated use of the C-X-C chemokine receptor type 4 (CXCR4) promoter to restrict AAV expression to tumour cells, in subcutaneous MCF-7 xenograft mouse models of breast cancer and in patient samples, using bioluminescent imaging and flow cytometric analysis. RESULTS: Higher transgene expression levels were observed in subcutaneous MCF-7 tumours relative to normal tissue (muscle) using the CXCR4 promoter, unlike a ubiquitously expressing Cytomegalovirus promoter construct, with preferential AAVCXCR4 expression in epithelial tumour and CXCR4-positive cells. Transgene expression following intravenously administered AAVCXCR4 in a model of liver metastasis was detected specifically in livers of tumour bearing mice. Ex vivo analysis using patient samples also demonstrated higher AAVCXCR4 expression in tumour compared with normal liver tissue. CONCLUSION: This study demonstrates for the first time, the potential for systemic administration of AAV2 vector for tumour-selective gene therapy.

  13. Is passive transmission of non-viral vectors through artificial insemination of sperm-DNA mixtures sufficient for chicken transgenesis?

    Science.gov (United States)

    Chaparian, Shahram; Abdulahnejad, Ahad; Rashidi, Farzad; Toghyani, Majid; Gheisari, Abbasali; Eghbalsaied, Shahin

    2016-06-17

    DNA uptake in the post-acrosomal region of the spermatozoa takes place exclusively in immotile spermatozoa that are naturally unable to fertilize eggs. The present study aimed to assess whether passive transmission of non-viral vectors to the surrounding areas of chicken embryos could be an alternate mechanism in chicken sperm-mediated gene transfer. First, the presence of nucleases in rooster seminal plasma was evaluated. Semen ejaculates from five roosters were centrifuged and the supernatant was incubated with pBL2 for 1 h. A robust nuclease cocktail was detected in the rooster semen. To overcome these nucleases, plasmid-TransIT combinations were incubated with semen for 1 h. Incubation of exogenous DNA in the lipoplex structure could considerably bypass the semen nuclease effect. Then, intravaginal insemination of 1 × 10(9) sperm mixed with lipoplexes (40 µg pBL2:40 µl TransIT) was carried out in 15 virgin hens. Neither the epithelial tissue from the inseminated female reproductive tracts nor the produced embryos following artificial insemination showed the transgene. To remove any bias in the transgene transmission possibility, the plasmid-TransIT admixture was directly injected in close vicinity of the embryos in newly laid eggs. Nonetheless, none of the produced fetuses or chicks carried the transgene. In conclusion, the results of the present study revealed a nuclease admixture in rooster seminal plasma, and passive/active transmission of the non-viral vector into close vicinity of the chicken embryo was inefficient for producing transgenic chicks.

  14. Viral glycoprotein-mediated cell fusion assays using vaccinia virus vectors.

    Science.gov (United States)

    Bossart, Katharine N; Broder, Christopher C

    2004-01-01

    The vaccinia virus-based expression of viral envelope glycoprotein genes-derived from enveloped viruses that infect their respective host cells through a pH-independent mechanism of membrane fusion-has been a powerful tool in helping to characterize these important attachment and fusion proteins. The cellular expression of these viral envelope glycoproteins has allowed for the measurement of membrane fusion events using cell-cell fusion or syncytia formation. This method has been enhanced by the addition of a reporter-gene system to the vaccinia virus-based cell-cell fusion assay. This improvement has provided a high-throughput and quantitative aspect to this assay, which can serve as a surrogate for virus entry and is therefore ideally suited in the characterization of numerous enveloped viruses, including biological safety level-4 (BSL-4) agents. This chapter will detail the methods of the vaccinia virus-based reporter-gene fusion assay and how it may be used to characterize the fusion mediated by the BSL-4-classified Hendra and Nipah viruses.

  15. Vectors

    DEFF Research Database (Denmark)

    Boeriis, Morten; van Leeuwen, Theo

    2017-01-01

    This article revisits the concept of vectors, which, in Kress and van Leeuwen’s Reading Images (2006), plays a crucial role in distinguishing between ‘narrative’, action-oriented processes and ‘conceptual’, state-oriented processes. The use of this concept in image analysis has usually focused...... on the most salient vectors, and this works well, but many images contain a plethora of vectors, which makes their structure quite different from the linguistic transitivity structures with which Kress and van Leeuwen have compared ‘narrative’ images. It can also be asked whether facial expression vectors...... should be taken into account in discussing ‘reactions’, which Kress and van Leeuwen link only to eyeline vectors. Finally, the question can be raised as to whether actions are always realized by vectors. Drawing on a re-reading of Rudolf Arnheim’s account of vectors, these issues are outlined...

  16. Increased recombinant protein production owing to expanded opportunities for vector integration in high chromosome number Chinese hamster ovary cells.

    Science.gov (United States)

    Yamano, Noriko; Takahashi, Mai; Ali Haghparast, Seyed Mohammad; Onitsuka, Masayoshi; Kumamoto, Toshitaka; Frank, Jana; Omasa, Takeshi

    2016-08-01

    Chromosomal instability is a characteristic of Chinese hamster ovary (CHO) cells. Cultures of these cells gradually develop heterogeneity even if established from a single cell clone. We isolated cells containing different numbers of chromosomes from a CHO-DG44-based human granulocyte-macrophage colony stimulating factor (hGM-CSF)-producing cell line and found that high chromosome number cells showed higher hGM-CSF productivity. Therefore, we focused on the relationship between chromosome aneuploidy of CHO cells and high recombinant protein-producing cell lines. Distribution and stability of chromosomes were examined in CHO-DG44 cells, and two cell lines expressing different numbers of chromosomes were isolated from the original CHO-DG44 cell line to investigate the effect of aneuploid cells on recombinant protein production. Both cell lines were stably transfected with a vector that expresses immunoglobulin G3 (IgG3), and specific antibody production rates were compared. Cells containing more than 30 chromosomes had higher specific antibody production rates than those with normal chromosome number. Single cell analysis of enhanced green fluorescent protein (Egfp)-gene transfected cells revealed that increased GFP expression was relative to the number of gene integration sites rather than the difference in chromosome numbers or vector locations. Our results suggest that CHO cells with high numbers of chromosomes contain more sites for vector integration, a characteristic that could be advantageous in biopharmaceutical production.

  17. THE EFFECTS OF CRUDE RECOMBINANT VIRAL PROTEIN VACCINES AGAINST GROUPER SLEEPY DISEASE IRIDOVIRUS (GSDIV ON HUMPBACK GROUPER (Cromileptes altivelis

    Directory of Open Access Journals (Sweden)

    Ketut Mahardika

    2015-12-01

    Full Text Available Infection of Megalocytivirus cause serious mass mortality in marine fish in South East Asian countries. The aim of this study was to produce recombinant of GSDIV capsid protein and its protection to humpback grouper Cromileptes altivelis against grouper sleepy disease iridovirus (GSDIV. A major capsid protein (MCP was selected for use as a crude subunit vaccines. This gene target (MCP was inserted to the protein expression system vector of pET SUMO and cloned in cells bacteria Escherichia coli strain BL-21. The MCP was succeded to be induced using 1 mM of IPTG. Results of protein analysis using MALDI TOF-TOF indicated that the MCP has measurement of 49.566 kDa with PI index of 6.00, and contained 453 amino acids. BLAST homology analysis exhibited that the amino acid sequence of the MCP showed high similarity with MCP of Red Sea Bream Iridovirus (RSIV. E. coli expressing MCP protein was inactivated using 0.03% formalin overnight and washed using PBS. The inactivated E. coli as a crude subunit vaccine was then injected intramuscularly to humpback grouper juveniles. Subsequently, the juveniles were challenged tested with GSDIV. The juveniles vaccinated with the MCP recombinant bacteria showed significantly higher survival rates than control those vaccinated with PBS. Thus, the MCP fusion protein is considered as a potential vaccine against GSDIV infections in grouper.

  18. Viral vectors for gene modification of plants as chem/bio sensors.

    Energy Technology Data Exchange (ETDEWEB)

    Manginell, Monica; Harper, Jason C.; Arango, Dulce C.; Brozik, Susan Marie; Dolan, Patricia L.

    2006-11-01

    Chemical or biological sensors that are specific, sensitive, and robust allowing intelligence gathering for verification of nuclear non-proliferation treaty compliance and detouring production of weapons of mass destruction are sorely needed. Although much progress has been made in the area of biosensors, improvements in sensor lifetime, robustness, and device packaging are required before these devices become widely used. Current chemical and biological detection and identification techniques require less-than-covert sample collection followed by transport to a laboratory for analysis. In addition to being expensive and time consuming, results can often be inconclusive due to compromised sample integrity during collection and transport. We report here a demonstration of a plant based sensor technology which utilizes mature and seedling plants as chemical sensors. One can envision genetically modifying native plants at a site of interest that can report the presence of specific toxins or chemicals. In this one year project we used a developed inducible expression system to show the feasibility of plant sensors. The vector was designed as a safe, non-infectious vector which could be used to invade, replicate, and introduce foreign genes into mature host plants that then allow the plant to sense chem/bio agents. The genes introduced through the vector included a reporter gene that encodes for green fluorescent protein (GFP) and a gene that encodes for a mammalian receptor that recognizes a chemical agent. Specifically, GFP was induced by the presence of 17-{beta}-Estradiol (estrogen). Detection of fluorescence indicated the presence of the target chemical agent. Since the sensor is a plant, costly device packaging development or manufacturing of the sensor were not required. Additionally, the biological recognition and reporting elements are maintained in a living, natural environment and therefore do not suffer from lifetime disadvantages typical of most biosensing

  19. WNV infection - an emergent vector borne viral infection in Serbia: Current situation

    Directory of Open Access Journals (Sweden)

    Petrović Tamaš

    2015-01-01

    Full Text Available West Nile virus (WNV is a neurovirulent mosquito-borne Flavivirus with zoonotic potential. Virus is maintained in nature in an enzootic transmission cycle between avian hosts and mosquito vectors, but occasionally infects other vertebrates. The infection in horses and humans can be asymptomatic or it can have different clinical manifestations ranging from light febrile diseases to fatal meningoencephalitis. Recently, the number, frequency and severity of outbreaks with neurological consequences for birds, humans and horses have increased dramatically throughout central and south Europe, including Serbia, posing a serious veterinary and public health problem. The emergency of WNV infections in Serbia is described through the current epidemiology situation based on recent data on the incidence of WNV infection among virus natural hosts and vectors; sentinel (horses and other animal species, and in human population. The results of the WNV serology studies conducted on horse blood samples collected in different occasions during the last six years, and the results of the serology studies conducted among other animal species like pigs, wild boars, roe deer and dogs in Serbia are presented and discussed. Also, the results of the first studies on WNV presence in mosquito vectors and in wild birds as virus natural hosts in Serbia are presented and analyzed. In addition, the data on the WNV serology studies conducted in human population in Serbia in the last few years, and the existing data of WNV outbreaks in 2012 and 2013 are included. Regarding the existing knowledge on WNV epidemiology situation, the crucial role of veterinary service in early detection of WNV presence and ongoing national program of WNV surveillance in sentinel animals, mosquitoes and wild birds are discussed.

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

    Science.gov (United States)

    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.

  1. Increased cellular immune responses and CD4+ T-cell proliferation correlate with reduced plasma viral load in SIV challenged recombinant simian varicella virus - simian immunodeficiency virus (rSVV-SIV vaccinated rhesus macaques

    Directory of Open Access Journals (Sweden)

    Pahar Bapi

    2012-08-01

    Full Text Available Abstract Background An effective AIDS vaccine remains one of the highest priorities in HIV-research. Our recent study showed that vaccination of rhesus macaques with recombinant simian varicella virus (rSVV vector – simian immunodeficiency virus (SIV envelope and gag genes, induced neutralizing antibodies and cellular immune responses to SIV and also significantly reduced plasma viral loads following intravenous pathogenic challenge with SIVMAC251/CX1. Findings The purpose of this study was to define cellular immunological correlates of protection in rSVV-SIV vaccinated and SIV challenged animals. Immunofluorescent staining and multifunctional assessment of SIV-specific T-cell responses were evaluated in both Experimental and Control vaccinated animal groups. Significant increases in the proliferating CD4+ T-cell population and polyfunctional T-cell responses were observed in all Experimental-vaccinated animals compared with the Control-vaccinated animals. Conclusions Increased CD4+ T-cell proliferation was significantly and inversely correlated with plasma viral load. Increased SIV-specific polyfunctional cytokine responses and increased proliferation of CD4+ T-cell may be crucial to control plasma viral loads in vaccinated and SIVMAC251/CX1 challenged macaques.

  2. Agrobacterium-mediated transformation of maize (Zea mays) with Cre-lox site specific recombination cassettes in BIBAC vectors.

    Science.gov (United States)

    Vega, Juan M; Yu, Weichang; Han, Fangpu; Kato, Akio; Peters, Eric M; Zhang, Zhanyuan J; Birchler, James A

    2008-04-01

    The Cre/loxP site-specific recombination system has been applied in various plant species including maize (Zea mays) for marker gene removal, gene targeting, and functional genomics. A BIBAC vector system was adapted for maize transformation with a large fragment of genetic material including a herbicide resistance marker gene, a 30 kb yeast genomic fragment as a marker for fluorescence in situ hybridization (FISH), and a 35S-lox-cre recombination cassette. Seventy-five transgenic lines were generated from Agrobacterium-mediated transformation of a maize Hi II line with multiple B chromosomes. Eighty-four inserts have been localized among all 10 A chromosome pairs by FISH using the yeast DNA probe together with a karyotyping cocktail. No inserts were found on the B chromosomes; thus a bias against the B chromosomes by the Agrobacterium-mediated transformation was revealed. The expression of a cre gene was confirmed in 68 of the 75 transgenic lines by a reporter construct for cre/lox mediated recombination. The placement of the cre/lox site-specific recombination system in many locations in the maize genome will be valuable materials for gene targeting and chromosome engineering.

  3. Adeno-associated viral vector serotype 5 poorly transduces liver in rat models.

    Directory of Open Access Journals (Sweden)

    Paula S Montenegro-Miranda

    Full Text Available Preclinical studies in mice and non-human primates showed that AAV serotype 5 provides efficient liver transduction and as such seems a promising vector for liver directed gene therapy. An advantage of AAV5 compared to serotype 8 already shown to provide efficient correction in a phase 1 trial in patients suffering from hemophilia B, is its lower seroprevalence in the general population. Our goal is liver directed gene therapy for Crigler-Najjar syndrome type I, inherited severe unconjugated hyperbilirubinemia caused by UGT1A1 deficiency. In a relevant animal model, the Gunn rat, we compared the efficacy of AAV 5 and 8 to that of AAV1 previously shown to be effective. Ferrying a construct driving hepatocyte specific expression of UGT1A1, both AAV8 and AAV1 provided an efficient correction of hyperbilirubinemia. In contrast to these two and to other animal models AAV5 failed to provide any correction. To clarify whether this unexpected finding was due to the rat model used or due to a problem with AAV5, the efficacy of this serotype was compared in a mouse and two additional rat strains. Administration of an AAV5 vector expressing luciferase under the control of a liver specific promoter confirmed that this serotype poorly performed in rat liver, rendering it not suitable for proof of concept studies in this species.

  4. Activation of cytotoxic and regulatory functions of NK cells by Sindbis viral vectors.

    Directory of Open Access Journals (Sweden)

    Tomer Granot

    Full Text Available Oncolytic viruses (OVs represent a relatively novel anti-cancer modality. Like other new cancer treatments, effective OV therapy will likely require combination with conventional treatments. In order to design combinatorial treatments that work well together, a greater scrutiny of the mechanisms behind the individual treatments is needed. Sindbis virus (SV based vectors have previously been shown to target and kill tumors in xenograft, syngeneic, and spontaneous mouse models. However, the effect of SV treatment on the immune system has not yet been studied. Here we used a variety of methods, including FACS analysis, cytotoxicity assays, cell depletion, imaging of tumor growth, cytokine blockade, and survival experiments, to study how SV therapy affects Natural Killer (NK cell function in SCID mice bearing human ovarian carcinoma tumors. Surprisingly, we found that SV anti-cancer efficacy is largely NK cell-dependent. Furthermore, the enhanced therapeutic effect previously observed from Sin/IL12 vectors, which carry the gene for interleukin 12, is also NK cell dependent, but works through a separate IFNγ-dependent mechanism, which also induces the activation of peritoneal macrophages. These results demonstrate the multimodular nature of SV therapy, and open up new possibilities for potential synergistic or additive combinatorial therapies with other treatments.

  5. (13) C-metabolic flux analysis of human adenovirus infection: Implications for viral vector production.

    Science.gov (United States)

    Carinhas, Nuno; Koshkin, Alexey; Pais, Daniel A M; Alves, Paula M; Teixeira, Ana P

    2017-01-01

    Adenoviruses are human pathogens increasingly used as gene therapy and vaccination vectors. However, their impact on cell metabolism is poorly characterized. We performed carbon labeling experiments with [1,2-(13) C]glucose or [U-(13) C]glutamine to evaluate metabolic alterations in the amniocyte-derived, E1-transformed 1G3 cell line during production of a human adenovirus type 5 vector (AdV5). Nonstationary (13) C-metabolic flux analysis revealed increased fluxes of glycolysis (17%) and markedly PPP (over fourfold) and cytosolic AcCoA formation (nearly twofold) following infection of growing cells. Interestingly, infection of growth-arrested cells increased overall carbon flow even more, including glutamine anaplerosis and TCA cycle activity (both over 1.5-fold), but was unable to stimulate the PPP and was associated with a steep drop in AdV5 replication (almost 80%). Our results underscore the importance of nucleic and fatty acid biosynthesis for adenovirus replication. Overall, we portray a metabolic blueprint of human adenovirus infection, highlighting similarities with other viruses and cancer, and suggest strategies to improve AdV5 production. Biotechnol. Bioeng. 2017;114: 195-207. © 2016 Wiley Periodicals, Inc.

  6. [Construction of a recombined adenovirus vector carrying pri-miR-21 gene and research on it's target gene TLR4].

    Science.gov (United States)

    Zhao, Jing; Xu, Guang-xian; Jia, Wei; Dong, Hui; Zhang, Yi-lin; Zhao, Zhi-jun; Wei, Jun

    2012-02-01

    To construct the recombined adenovirus vector carrying pri-miR-21 gene, which can express mature miR-21 efficiently, and to study the interaction of miR- 21 with its target gene TLR4. Using healthy mouse's gDNA as template, the primary miR-21 coding sequence was amplified by PCR and cloned into a shuttle vector pAdTrack-CMV. Constructed plasmid was sequenced and linearized for homologous recombination with pAdEasy-1 vector in BJ5183 bacteria. The recombined adenovirus vector carrying pri-miR-21 gene was used to challenge HeLa cell. The candidate target gene of miR-21 was determined by miRNA analysis databases. The expression level of TLR4 protein was detected by western blotting. Through the PCR, restriction enzyme digestion, DNA sequencing and expression of GFP, recombinant adenoviral vector pri-miR-21 gene was constructed successfully. Bioinformatic analysis suggested a few possible binding sites between miR-21 and TLR4. Results showed that miR-21 down-regulated TLR4 at protein levels. The recombinant adenoviral vector containing pri- miR-21 was successfully constructed. miR-21 gene interfered with the expression of TLR4 target gene.

  7. Oxygen vectors used for S-adenosylmethionine production in recombinant Pichia pastoris with sorbitol as supplemental carbon source.

    Science.gov (United States)

    Zhang, Jian-Guo; Wang, Xue-Dong; Zhang, Ji-Ning; Wei, Dong-Zhi

    2008-04-01

    In order to increase the yield of S-adenosylmethionine (SAM) in recombinant Pichia pastoris, a strategy of adding oxygen vectors and supplemental carbon sources was described. Three organic solutions were used as oxygen vectors for SAM accumulation at different concentrations and addition times. Firstly, n-hexane (0.5%) or n-heptane (1.0%) was added after 72 h of cultivation to improve SAM production. Carbon metabolism was scarce during the induction phase because of low methanol concentration. Secondly, sorbitol (1.2%), selected from three candidates (glycerol, lactic acid, and sorbitol), was used as the supplemental carbon source. The yield of SAM was improved significantly (53.26%) at 1.0%n-heptane added at 72 h (48 h induction), 1.2% sorbitol added at 72, 96, and 120 h of cultivation and 1.0% methanol added every 24 h during cultivation.

  8. Rainbow trout surviving infections of viral haemorrhagic septicemia virus (VHSV) show lasting antibodies to recombinant G protein fragments.

    Science.gov (United States)

    Encinas, P; Gomez-Casado, E; Fregeneda-Grandes; Olesen, N J; Lorenzen, N; Estepa, A; Coll, J M

    2011-03-01

    Rainbow trout antibodies (Abs) binding to recombinant fragments (frgs) derived from the protein G of the viral haemorrhagic septicemia virus (VHSV)-07.71 strain, could be detected by ELISA (frg-ELISA) in sera from trout surviving laboratory-controlled infections. Abs were detected not only by using sera from trout infected with the homologous VHSV isolate but also with the VHSV-DK-201433 heterologous isolate, which had 13 amino acid changes. Sera from healthy trout and/or from trout surviving infectious haematopoietic necrosis virus (IHNV) infection, were used to calculate cut-off absorbances to differentiate negative from positive sera. Specific anti-VHSV Abs could then be detected by using any of the following frgs: frg11 (56-110), frg15 (65-250), frg16 (252-450) or G21-465. While high correlations were found among the ELISA values obtained with the different frgs, no correlations between any frg-ELISA and complement-dependent 50% plaque neutralization test (PNT) titres could be demonstrated. Between 4 and 10 weeks after VHSV infection, more trout sera were detected as positives by using heterologous frg-ELISA rather than homologous PNT. Furthermore, the percentage of positive sera detected by frg11-ELISA increased with time after infection to reach 100%, while those detected by complement-dependent PNT decreased to 29.4%, thus confirming that the lack of neutralizing Abs does not mean the lack of any anti-VHSV Abs in survivor trout sera. Preliminary results with sera from field samples suggest that further refinements of the frg-ELISA could allow detection of anti-VHSV trout Abs in natural outbreaks caused by different heterologous VHSV isolates. The homologous frg-ELISA method could be useful to follow G immunization attempts during vaccine development and/or to best understand the fish Ab response during VHSV infections. The viral frgs approach might also be used with other fish species and/or viruses.

  9. Development of a sandwich Dot-ELISA for detecting bovine viral diarrhea virus antigen with E2 recombinant protein

    Institute of Scientific and Technical Information of China (English)

    Yuelan ZHAO; Yuzhu ZUO; Lei ZHANG; Jinghui FAN; Hanchun YANG; Jianhua QIN

    2009-01-01

    The IgG antibodies of rabbit anti-E2 protein of the bovine viral diarrhea virus were prepared by a general method from high efficiency serum immunized by E2 recombinant protein antigen expressed in E. coli prokaryotic expression system and were labeled to make enzymelabeled antibody with the method of NaIO4. A sandwich Dot enzyme-linked immunosorbent assay (Dot-ELISA) for the detection of BVDV was developed. The optimal reaction conditions of Dot-ELISAwere determined. The results show that optimal coating antibody was 300 μg·mL-1, the working concentration of HRP-labeled antibody was 1:50. The optimal blocking reagent and time were 5% bovine serum and 45 rain. The minimum detection of the content of antigen reached 1.35μg·mL-1. Compared with the routine IDEXX ELISA test kit with the whole virus, its specificity, sensitivity and coincidence rate were 90.48%, 96.55% and 95.24%, respectively. Compared with the sandwich Dot-ELISA with the negative staining electron microscope and RT-PCR, the coincidence rates were 90.9% and 93.1%, respectively. In addition, Bovine viral diarrhea virus (BVDV) antigen of 178 samples collected from cow farms in the Hebei Province, China, were detected by the developed Dot-ELISA and the IDEXX BVDV antigen Test Kit simultaneously, BVDV antigen positive rate was 39.89%-41.01%. The result of detecting clinical samples demonstrated that the established method showed its specificity, sensitivity and repeatability, whereas the results were easily interpreted without an ELISA reader.

  10. "Bronchial Artery Delivery of Viral Vectors for Gene delivery in Cystic Fibrosis; Superior to Airway Delivery?"

    Directory of Open Access Journals (Sweden)

    Coutelle Charles C

    2002-04-01

    Full Text Available Abstract Background Attempts at gene therapy for the pulmonary manifestations of Cystic Fibrosis have relied mainly on airway delivery. However the efficiency of gene transfer and expression in the airway epithelia has not reached therapeutic levels. Access to epithelial cells is not homogenous for a number of reasons and the submucosal glands cannot be reached via the airways. Presentation We propose to inject gene delivery vectors directly into bronchial arteries combined with pre-delivery of vascular endothelial growth factor to increase vascular endothelial permeability and post-delivery flow reduction by balloon occlusion. Thus it may be possible to reach mucous secreting cells of the bronchial luminal epithelium and the submucosal glands in an increased and homogenous fashion. Testing This combination of techniques to the best of our knowledge has not previously been investigated, and may enable us to overcome some of the current limitations to gene therapy for Cystic Fibrosis.

  11. Highly-Immunogenic Virally-Vectored T-cell Vaccines Cannot Overcome Subversion of the T-cell Response by HCV during Chronic Infection.

    Science.gov (United States)

    Swadling, Leo; Halliday, John; Kelly, Christabel; Brown, Anthony; Capone, Stefania; Ansari, M Azim; Bonsall, David; Richardson, Rachel; Hartnell, Felicity; Collier, Jane; Ammendola, Virginia; Del Sorbo, Mariarosaria; Von Delft, Annette; Traboni, Cinzia; Hill, Adrian V S; Colloca, Stefano; Nicosia, Alfredo; Cortese, Riccardo; Klenerman, Paul; Folgori, Antonella; Barnes, Eleanor

    2016-08-02

    An effective therapeutic vaccine for the treatment of chronic hepatitis C virus (HCV) infection, as an adjunct to newly developed directly-acting antivirals (DAA), or for the prevention of reinfection, would significantly reduce the global burden of disease associated with chronic HCV infection. A recombinant chimpanzee adenoviral (ChAd3) vector and a modified vaccinia Ankara (MVA), encoding the non-structural proteins of HCV (NSmut), used in a heterologous prime/boost regimen induced multi-specific, high-magnitude, durable HCV-specific CD4+ and CD8+ T-cell responses in healthy volunteers, and was more immunogenic than a heterologous Ad regimen. We now assess the immunogenicity of this vaccine regimen in HCV infected patients (including patients with a low viral load suppressed with interferon/ribavirin therapy), determine T-cell cross-reactivity to endogenous virus, and compare immunogenicity with that observed previously in both healthy volunteers and in HCV infected patients vaccinated with the heterologous Ad regimen. Vaccination of HCV infected patients with ChAd3-NSmut/MVA-NSmut was well tolerated. Vaccine-induced HCV-specific T-cell responses were detected in 8/12 patients; however, CD4+ T-cell responses were rarely detected, and the overall magnitude of HCV-specific T-cell responses was markedly reduced when compared to vaccinated healthy volunteers. Furthermore, HCV-specific cells had a distinct partially-functional phenotype (lower expression of activation markers, granzyme B, and TNFα production, weaker in vitro proliferation, and higher Tim3 expression, with comparable Tbet and Eomes expression) compared to healthy volunteers. Robust anti-vector T-cells and antibodies were induced, showing that there is no global defect in immunity. The level of viremia at the time of vaccination did not correlate with the magnitude of the vaccine-induced T-cell response. Full-length, next-generation sequencing of the circulating virus demonstrated that T-cells were

  12. Highly-Immunogenic Virally-Vectored T-cell Vaccines Cannot Overcome Subversion of the T-cell Response by HCV during Chronic Infection

    Directory of Open Access Journals (Sweden)

    Leo Swadling

    2016-08-01

    Full Text Available An effective therapeutic vaccine for the treatment of chronic hepatitis C virus (HCV infection, as an adjunct to newly developed directly-acting antivirals (DAA, or for the prevention of reinfection, would significantly reduce the global burden of disease associated with chronic HCV infection. A recombinant chimpanzee adenoviral (ChAd3 vector and a modified vaccinia Ankara (MVA, encoding the non-structural proteins of HCV (NSmut, used in a heterologous prime/boost regimen induced multi-specific, high-magnitude, durable HCV-specific CD4+ and CD8+ T-cell responses in healthy volunteers, and was more immunogenic than a heterologous Ad regimen. We now assess the immunogenicity of this vaccine regimen in HCV infected patients (including patients with a low viral load suppressed with interferon/ribavirin therapy, determine T-cell cross-reactivity to endogenous virus, and compare immunogenicity with that observed previously in both healthy volunteers and in HCV infected patients vaccinated with the heterologous Ad regimen. Vaccination of HCV infected patients with ChAd3-NSmut/MVA-NSmut was well tolerated. Vaccine-induced HCV-specific T-cell responses were detected in 8/12 patients; however, CD4+ T-cell responses were rarely detected, and the overall magnitude of HCV-specific T-cell responses was markedly reduced when compared to vaccinated healthy volunteers. Furthermore, HCV-specific cells had a distinct partially-functional phenotype (lower expression of activation markers, granzyme B, and TNFα production, weaker in vitro proliferation, and higher Tim3 expression, with comparable Tbet and Eomes expression compared to healthy volunteers. Robust anti-vector T-cells and antibodies were induced, showing that there is no global defect in immunity. The level of viremia at the time of vaccination did not correlate with the magnitude of the vaccine-induced T-cell response. Full-length, next-generation sequencing of the circulating virus demonstrated that T

  13. Highly-Immunogenic Virally-Vectored T-cell Vaccines Cannot Overcome Subversion of the T-cell Response by HCV during Chronic Infection

    Science.gov (United States)

    Swadling, Leo; Halliday, John; Kelly, Christabel; Brown, Anthony; Capone, Stefania; Ansari, M. Azim; Bonsall, David; Richardson, Rachel; Hartnell, Felicity; Collier, Jane; Ammendola, Virginia; Del Sorbo, Mariarosaria; Von Delft, Annette; Traboni, Cinzia; Hill, Adrian V. S.; Colloca, Stefano; Nicosia, Alfredo; Cortese, Riccardo; Klenerman, Paul; Folgori, Antonella; Barnes, Eleanor

    2016-01-01

    An effective therapeutic vaccine for the treatment of chronic hepatitis C virus (HCV) infection, as an adjunct to newly developed directly-acting antivirals (DAA), or for the prevention of reinfection, would significantly reduce the global burden of disease associated with chronic HCV infection. A recombinant chimpanzee adenoviral (ChAd3) vector and a modified vaccinia Ankara (MVA), encoding the non-structural proteins of HCV (NSmut), used in a heterologous prime/boost regimen induced multi-specific, high-magnitude, durable HCV-specific CD4+ and CD8+ T-cell responses in healthy volunteers, and was more immunogenic than a heterologous Ad regimen. We now assess the immunogenicity of this vaccine regimen in HCV infected patients (including patients with a low viral load suppressed with interferon/ribavirin therapy), determine T-cell cross-reactivity to endogenous virus, and compare immunogenicity with that observed previously in both healthy volunteers and in HCV infected patients vaccinated with the heterologous Ad regimen. Vaccination of HCV infected patients with ChAd3-NSmut/MVA-NSmut was well tolerated. Vaccine-induced HCV-specific T-cell responses were detected in 8/12 patients; however, CD4+ T-cell responses were rarely detected, and the overall magnitude of HCV-specific T-cell responses was markedly reduced when compared to vaccinated healthy volunteers. Furthermore, HCV-specific cells had a distinct partially-functional phenotype (lower expression of activation markers, granzyme B, and TNFα production, weaker in vitro proliferation, and higher Tim3 expression, with comparable Tbet and Eomes expression) compared to healthy volunteers. Robust anti-vector T-cells and antibodies were induced, showing that there is no global defect in immunity. The level of viremia at the time of vaccination did not correlate with the magnitude of the vaccine-induced T-cell response. Full-length, next-generation sequencing of the circulating virus demonstrated that T-cells were

  14. Establishment of human sperm-specific voltage-dependent anion channel 3 recombinant vector for the production of a male contraceptive vaccine

    Directory of Open Access Journals (Sweden)

    Asmarinah Asmarinah

    2012-05-01

    Full Text Available Background: The aim of this study was to construct a recombinant vector of human sperm specific VDAC3 gene for production of VDAC3 antibody, which is potential as male contraception vaccine.Methods: Target fragment sequence of VDAC3 gene was obtained through amplification of human sperm VDAC3 cDNA with primers covering exon 5 to exon 8. Its PCR product in size of 435 bp was cloned to the pET101/D-TOPO expression vector (5753 bp. E. coli bacteria were transformed with this vector. Cloning of VDAC3 fragment gene to the vector was confirmed by the using of XbaI restriction enzyme and PCR colony method with primers covering exons 5-8 of the human VDAC3 gene.Results: Alignment analysis of amplified fragment covering exon 5 to exon 8 of VDAC3 gene showed 94% homology to human VDAC3 gene from databank. After cloning to the expression vector and transformation to E. coli competent cells, twelve colonies could grow in culture media. Gel electrophoresis of sliced VDAC3 recombinant vector showed a single band in the size of 6181 bp in 8 colonies. After application of PCR colony and amplicon sequencing, the result showed a single band in the size of 435 bp and fragment sequence with 94% identity to human VDAC3 gene.Conclusion: The construction of human sperm specific VDAC3 gene recombinant vector was established in this study. In the future, this recombinant vector will be used to produce VDAC3 antibody for the development of a male contraception vaccine. (Med J Indones. 2012;21:61-5Keywords: Contraception, recombinant vector, sperm, VDAC3

  15. Recombinant E2 glycoprotein of bovine viral diarrhea virus induces a solid humoral neutralizing immune response but fails to confer total protection in cattle

    Directory of Open Access Journals (Sweden)

    S. Chimeno Zoth

    2007-06-01

    Full Text Available Two recombinant baculoviruses were produced in order to obtain a bovine viral diarrhea virus (BVDV immunogen: AcNPV/E2 expressing E2 glycoprotein, and AcNPV/E0E1E2 expressing the polyprotein region coding for the three structural proteins of BVDV (E0, E1, and E2. Mice were immunized with Sf9 cells infected with the recombinant baculoviruses in a water in oil formulation and the production of neutralizing antibodies was evaluated. Since E2 elicited higher neutralizing antibody titers than E0-E1-E2 polyprotein, it was selected to immunize cattle. Calves received two doses of recombinant E2 vaccine and were challenged with homologous BVDV 37 days later. The recombinant immunogen induced neutralizing titers which showed a mean value of 1.5 ± 0.27 on the day of challenge and reached a top value of 3.36 ± 0.36, 47 days later (84 days post-vaccination. On the other hand, sera from animals which received mock-infected Sf9 cells did not show neutralizing activity until 25 days post-challenge (62 days post-vaccination, suggesting that these antibodies were produced as a consequence of BVDV challenge. Even when no total protection was observed in cattle, in vitro viral neutralization assays revealed that the recombinant immunogen was able to induce neutralizing antibody synthesis against the homologous strain as well as against heterologous strains in a very efficient way.

  16. A Low Protein Binding Cationic Poly(2-oxazoline) as Non-Viral Vector

    KAUST Repository

    He, Zhijian

    2015-04-02

    © 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. Developing safe and efficient non-viral gene delivery systems remains a major challenge. We present a new cationic poly(2-oxazoline) (CPOx) block copolymer for gene therapy that was synthesized by sequential polymerization of non-ionic 2-methyl-2-oxazoline and a new 2-oxazoline monomer, 2-(N-methyl, N-Boc-amino)-methyl-2-oxazoline, followed by deprotection of the pendant secondary amine groups. Upon mixing with plasmid DNA (pDNA), CPOx forms small (diameter ≈80 nm) and narrowly dispersed polyplexes (PDI <0.2), which are stable upon dilution in saline and against thermal challenge. These polyplexes exhibited low plasma protein binding and very low cytotoxicity in vitro compared to the polyplexes of pDNA and poly(ethylene glycol)-b-poly(L-lysine) (PEG-b-PLL). CPOx/pDNA polyplexes at N/P = 5 bound considerably less plasma protein compared to polyplexes of PEG-b-PLL at the same N/P ratio. This is a unique aspect of the developed polyplexes emphasizing their potential for systemic delivery in vivo. The transfection efficiency of the polyplexes in B16 murine melanoma cells was low after 4 h, but increased significantly for 10 h exposure time, indicative of slow internalization of polyplexes. Addition of Pluronic P85 boosted the transfection using CPOx/pDNA polyplexes considerably. The low protein binding of CPOx/pDNA polyplexes is particularly interesting for the future development of targeted gene delivery.

  17. Incorporation of a lambda phage recombination system and EGFP detection to simplify mutagenesis of Herpes simplex virus bacterial artificial chromosomes

    Directory of Open Access Journals (Sweden)

    Weir Jerry P

    2007-05-01

    Full Text Available Abstract Background Targeted mutagenesis of the herpesvirus genomes has been facilitated by the use of bacterial artificial chromosome (BAC technology. Such modified genomes have potential uses in understanding viral pathogenesis, gene identification and characterization, and the development of new viral vectors and vaccines. We have previously described the construction of a herpes simplex virus 2 (HSV-2 BAC and the use of an allele replacement strategy to construct HSV-2 recombinants. While the BAC mutagenesis procedure is a powerful method to generate HSV-2 recombinants, particularly in the absence of selective marker in eukaryotic culture, the mutagenesis procedure is still difficult and cumbersome. Results Here we describe the incorporation of a phage lambda recombination system into an allele replacement vector. This strategy enables any DNA fragment containing the phage attL recombination sites to be efficiently inserted into the attR sites of the allele replacement vector using phage lambda clonase. We also describe how the incorporation of EGFP into the allele replacement vector can facilitate the selection of the desired cross-over recombinant BACs when the allele replacement reaction is a viral gene deletion. Finally, we incorporate the lambda phage recombination sites directly into an HSV-2 BAC vector for direct recombination of gene cassettes using the phage lambda clonase-driven recombination reaction. Conclusion Together, these improvements to the techniques of HSV BAC mutagenesis will facilitate the construction of recombinant herpes simplex viruses and viral vectors.

  18. Assessment of virally vectored autoimmunity as a biocontrol strategy for cane toads.

    Directory of Open Access Journals (Sweden)

    Jackie A Pallister

    Full Text Available BACKGROUND: The cane toad, Bufo (Chaunus marinus, is one of the most notorious vertebrate pests introduced into Australia over the last 200 years and, so far, efforts to identify a naturally occurring B. marinus-specific pathogen for use as a biological control agent have been unsuccessful. We explored an alternative approach that entailed genetically modifying a pathogen with broad host specificity so that it no longer caused disease, but carried a gene to disrupt the cane toad life cycle in a species specific manner. METHODOLOGY/PRINCIPAL FINDINGS: The adult beta globin gene was selected as the model gene for proof of concept of autoimmunity as a biocontrol method for cane toads. A previous report showed injection of bullfrog tadpoles with adult beta globin resulted in an alteration in the form of beta globin expressed in metamorphs as well as reduced survival. In B. marinus we established for the first time that the switch from tadpole to adult globin exists. The effect of injecting B. marinus tadpoles with purified recombinant adult globin protein was then assessed using behavioural (swim speed in tadpoles and jump length in metamorphs, developmental (time to metamorphosis, weight and length at various developmental stages, protein profile of adult globin and genetic (adult globin mRNA levels measures. However, we were unable to detect any differences between treated and control animals. Further, globin delivery using Bohle iridovirus, an Australian ranavirus isolate belonging to the Iridovirus family, did not reduce the survival of metamorphs or alter the form of beta globin expressed in metamorphs. CONCLUSIONS/SIGNIFICANCE: While we were able to show for the first time that the switch from tadpole to adult globin does occur in B. marinus, we were not able to induce autoimmunity and disrupt metamorphosis. The short development time of B. marinus tadpoles may preclude this approach.

  19. CONSTRUCTION AND IDENTIFICATION OF THE RECOMBINANT OF THE AAV VECTOR AND HUMAN INTERFERON-GAMMA

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    To construct and identify further a recombinant of Adeno-associated virus and interferon-gamma for gene therapy, the full-length IFN-γcDNA containing signal peptide was amplified by PCR, and then cloned into the pUC18. After screening, the fragment from the positive clone was then subcloned into pwpl9. After the correct recombinant was identified by digestion with SacI and BamHI, it was transfected into lympho- cyte cell line H9 mediated by calcium phosphate, and the expression of IFN-γ was detected by RT-PCR and ELISA. The result showed that the IFN-y were expressed in the H9 cells transfected with pwp/IFN-y. The so constructed recombinant plasmid pwpl9/IFN-y containing the full-length IFN-y gene was expressed in mam- malian cells.

  20. Efficiency for Gene Silencing Induction in Nicotiana Species by a Viral Satellite DNA Vector

    Institute of Scientific and Technical Information of China (English)

    You-Ping Xu; Lu-Ping Zheng; Qiu-Fang Xu; Chang-Chun Wang; Xue-Ping Zhou; Zu-Jian Wu; Xin-Zhong Cai

    2007-01-01

    Virus-induced gene silencing (VIGS) is a useful technique for rapid plant gene function analysis.We recently reported a new VIGS vector modified from Tomato yellow leaf curl China virus (TYLCCNV) DNAβ (DNAm β).In this study we compared In detail DNAmβ-induced gene silencing in four Nicotiana species including N.benthamiana, N.glutinosa, N.tabacum and N.paniculata.We found that DNAmβ-induced gene silencing in the four species was distinct in developing dynamics, tissue specificity, efficiency, and constancy in the plant life span.It was most efficient in N.benthamiana, where development of VIGS was most rapid, without tissue specificity and nearly 100% efficient.DNAmβ-induced gene silencing in N.Glutinosa was also efficient despite being slightly less than in N.benthamiana.It initially occurred in veins, later was scattered to mesophyll, finally led to complete silencing in whole leaves.In both species, VIGS constantly expressed until the plants died.However, DNAmβ-mediated VIGS in the other two Nicotiana species, N.tabacum and N.paniculata, was significantly less efficient.It was strictly limited within the veins of the silenced leaves, and constantly occurred only over 3-4 weeks.The upper leaves that emerged later stopped showing the silencing phenotype, DNAm β-induced gene silencing in N.benthamiana and N.glutinosa was not significantly influenced by the growth stage when the plants were agro-inoculated,and was not sensitive to high growth temperature up to 32℃, Our results indicate that this system has great potential as a versatile VIGS system for routine functional analysis of genes in some Nicotiana species.

  1. [Construction of recombinant human nerve growth factor (rh-β-NGF) eukaryotic vector and its expression in HEK293 cells].

    Science.gov (United States)

    Li, Jingchuan; Xue, Bofu; Yuan, Yuan; Ma, Mo; Zhu, Lin; Milburn, Rebecca; Le, Li; Hu, Peizhen; Ye, Jing

    2015-03-01

    Human nerve growth factor (NGF) is a nerve cell growth regulation factor, which can provide nutrition for the neurons and promote the neurites outgrowth. In order to produce large-scale recombinant human nerve growth factor (rh-beta-NGF), we constructed a plasmid vector, which can stably express the rh-beta-NGF in the HEK293 cell lines. First, the plasmid of pCMV-beta-NGF-IRES-dhfr was constructed and transformed into HEK293 cells. Then MTX pressurized filter and limiting dilution methods were used to obtain monoclonal HEK293 cell lines. After stepwise reducing serum in culture media, the cells eventually adapted to serum-free medium and secreted rh-beta-NGF. SDS-PAGE analysis revealed that the expression product owned a molecular weight of about 13 kDa and a purity of more than 50%. The peptide mapping sequencing analysis demonstrated the sequences of rh-beta-NGF matched with the theoretical ones. Later we purified this protein by ion exchange and molecular sieve chromatograph. Finally, our experimental results exhibited that the recombinant cell lines can stably express rh-beta-NGF with a high efficiency of more than 20 pg/cell x day. In addition, this protein could successfully induce differentiation of PC12 cells. In summary, our recombinant HEK293 cells can express bio-active rh-beta-NGF with great efficiency and stability, which supply a valid basis to large-scale production of rh-beta-NGF.

  2. Recombinant AAV Vectors for Enhanced Expression of Authentic IgG.

    Directory of Open Access Journals (Sweden)

    Sebastian P Fuchs

    Full Text Available Adeno-associated virus (AAV has become a vector of choice for the treatment of a variety of genetic diseases that require safe and long-term delivery of a missing protein. Muscle-directed gene transfer for delivery of protective antibodies against AIDS viruses and other pathogens has been used experimentally in mice and monkeys. Here we examined a number of variations to AAV vector design for the ability to produce authentic immunoglobulin G (IgG molecules. Expression of rhesus IgG from a single single-stranded AAV (ssAAV vector (one vector approach was compared to expression from two self-complementary AAV (scAAV vectors, one for heavy chain and one for light chain (two vector approach. Both the one vector and the two vector approaches yielded considerable levels of expressed full-length IgG. A number of modifications to the ssAAV expression system were then examined for their ability to increase the efficiency of IgG expression. Inclusion of a furin cleavage sequence with a linker peptide just upstream of the 2A self-cleaving sequence from foot-and-mouth disease virus (F2A increased IgG expression approximately 2 fold. Inclusion of these sequences also helped to ensure a proper sequence at the C-terminal end of the heavy chain. Inclusion of the post-transcriptional regulatory element from woodchuck hepatitis virus (WPRE further increased IgG expression 1.5-2.0 fold. IgG1 versions of the two rhesus IgGs that were examined consistently expressed better than the IgG2 forms. In contrast to what has been reported for AAV2-mediated expression of other proteins, introduction of capsid mutations Y445F and Y731F did not increase ssAAV1-mediated expression of IgG as determined by transduction experiments in cell culture. Our findings provide a rational basis for AAV vector design for expression of authentic IgG.

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

    Science.gov (United States)

    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. © 2014 Wiley Periodicals, Inc.

  4. Study on cellular internalization of poly(vinyldiaminotriazine)-based hydrosen bonding type non-viral trans-gene vector

    Institute of Scientific and Technical Information of China (English)

    YE GuiXiang; CAO ZhiQiang; LIN Lin; CHEN DaYong; LIU WenGuang

    2008-01-01

    Previously we successfully prepared poly(vinyldiaminotriazine)(PVDT)-based non-viral vectors which complexed plasmid DNA via hydrogen bonding with adenine-thymine base pairs. In this report, surface charges and complex sizes of this system were further examined. The results showed that PVDT-based polymer could cover surface charges of DNA resulting in slightly negative or neutral complexes. It was also found that the complex sizes were governed by two events: the aggregation induced by the instability of neutral particles, and more compact complexes produced by PVDT-based polymers. In the study of cellular uptake, chlorpromazine and filipin III were used to inhibit clathrin- and caveolae-mediated endocytosis, respectively. We found that PVDT-based systems were transported into cells via a non-clathrin, non-caveolae mediated endocytosis. This special process was studied by temperature inhibition and kinetics assays. It was revealed that such a pathway was characterized by (i) a more energy dependent process and (ii) a much slow transfection-effective internalization.

  5. Viral vector-mediated downregulation of RhoA increases survival and axonal regeneration of retinal ganglion cells

    Directory of Open Access Journals (Sweden)

    Jan Christoph Koch

    2014-09-01

    Full Text Available The Rho/ROCK pathway is a promising therapeutic target in neurodegenerative and neurotraumatic diseases. Pharmacological inhibition of various pathway members has been shown to promote neuronal regeneration and survival. However, because pharmacological inhibitors are inherently limited in their specificity, shRNA-mediated approaches can add more information on the function of each single kinase involved. Thus, we generated adeno-associated viral vectors (AAV to specifically downregulate RhoA via shRNA. We found that specific knockdown of RhoA promoted neurite outgrowth of retinal ganglion cells (RGC grown on the inhibitory substrate CSPG as well as neurite regeneration of primary midbrain neurons after scratch lesion. In the rat optic nerve crush model in vivo, downregulation of RhoA significantly enhanced axonal regeneration compared to control. Moreover, survival of RGCs transduced with AAV expressing RhoA-shRNA was substantially increased at two weeks after optic nerve axotomy.Compared to previous data using pharmacological inhibitors to target RhoA, its upstream regulator Nogo or its main downstream target ROCK2, the specific effects of RhoA downregulation shown here were more pronounced in regard to promoting RGC survival while the stimulatory effects on neurite outgrowth were rather moderate. Taken together, we show here that specific knockdown of RhoA substantially increases neuronal survival after optic nerve axotomy and modestly increases neurite outgrowth in vitro and axonal regeneration after optic nerve crush.

  6. An influenza viral vector Brucella abortus vaccine induces good cross-protection against Brucella melitensis infection in pregnant heifers.

    Science.gov (United States)

    Tabynov, Kaissar; Ryskeldinova, Sholpan; Sansyzbay, Abylai

    2015-07-17

    Brucella melitensis can be transmitted and cause disease in cattle herds as a result of inadequate management of mixed livestock farms. Ideally, vaccines against Brucella abortus for cattle should also provide cross-protection against B. melitensis. Previously we created a novel influenza viral vector B. abortus (Flu-BA) vaccine expressing the Brucella ribosomal proteins L7/L12 or Omp16. This study demonstrated Flu-BA vaccine with adjuvant Montanide Gel01 provided 100% protection against abortion in vaccinated pregnant heifers and good cross-protection of the heifers and their calves or fetuses (90-100%) after challenge with B. melitensis 16M; the level of protection provided by Flu-BA was comparable to the commercial vaccine B. abortus S19. In terms of the index of infection and colonization of Brucella in tissues, both vaccines demonstrated significant (P=0.02 to P<0.0001) protection against B. melitensis 16M infection compared to the negative control group (PBS+Montanide Gel01). Thus, we conclude the Flu-BA vaccine provides cross-protection against B. melitensis infection in pregnant heifers.

  7. Single-step cloning-screening method: a new tool for developing and studying high-titer viral vector producer cells.

    Science.gov (United States)

    Rodrigues, A F; Formas-Oliveira, A S; Guerreiro, M R; Tomás, H A; Alves, P M; Coroadinha, A S

    2015-09-01

    This article describes a novel method merging the cloning of viral vector producer cells with vector titer screening, allowing for screening 200-500 clones in 2 weeks. It makes use of a GFP separated into two fragments, S10 and S11 (Split GFP), fluorescing only upon transcomplementation. Producer cells carrying a S11 viral transgene are cloned in 96-well plates and co-cultured with target cells stably expressing S10. During the period of clone expansion, S11 viruses infect S10 target cells reconstituting the GFP signal. Transcomplemented fluorescence data provide direct estimation of the clone's productivity and can be analyzed in terms of density distribution, offering valuable information on the average productivity of the cell population and allowing the identification of high-producing clones. The method was validated by establishing a retrovirus producer from a nude cell line, in <3 months, inserting three vector constructs without clone selection or screening in between. Clones producing up to 10(8) infectious particles per ml were obtained, delivering optimal ratios of infectious-to-total particles (1 to 5). The method was additionally used to evaluate the production performance of HEK 293 and HEK 293T cell lines demonstrating that the latter sustains increased titers. Finally, it was used to study genetic manipulation of glutathione metabolism in retrovirus production showing that changing cell metabolism steers higher vector expression with titer increases of more than one order of magnitude.This method is a valuable tool not only for cell line development but also for genetic manipulation of viral vector and/or producer cells contributing to advancing the field of viral gene therapy.

  8. Forced recombination of psi-modified murine leukaemia virus-based vectors with murine leukaemia-like and VL30 murine endogenous retroviruses

    DEFF Research Database (Denmark)

    Mikkelsen, J G; Lund, Anders Henrik; Duch, M;

    1999-01-01

    -impaired Akv-MLV-derived vectors, we here examine putative genetic interactions between vector RNAs and copackaged endogenous retroviral RNAs of the murine leukaemia virus (MLV) and VL30 retroelement families. We show (i) that MLV recombination is not blocked by nonhomology within the 5' untranslated region...... harbouring the supposed RNA dimer-forming cis -elements and (ii) that copackaged retroviral RNAs can recombine despite pronounced sequence dissimilarity at the cross-over site(s) and within parts of the genome involved in RNA dimerization, encapsidation and strand transferring during reverse transcription....... We note that recombination-based rescue of primer binding site knock-out retroviral vectors may constitute a sensitive assay to register putative genetic interactions involving endogenous retroviral RNAs present in cells of various species....

  9. Shuttle vectors for cloning recombinant DNA in Escherichia coli and Streptomyces griseofuscus C581.

    OpenAIRE

    Larson, J L; Hershberger, C L

    1984-01-01

    The replicon of the Streptomyces plasmid SCP2 was located on a 5.9-kilobase EcoRI-SalI restriction fragment. The SCP2 replicon was combined with Escherichia coli plasmid pBR322 and genes specifying neomycin resistance and thiostrepton resistance in streptomycetes to construct shuttle vectors that are useful for cloning in E. coli and streptomycetes.

  10. Role of regulatory T-cells in immunization strategies involving a recombinant alphavirus vector system

    NARCIS (Netherlands)

    Walczak, Mateusz; Regts, Joke; van Oosterhout, Antoon J. M.; Boon, Louis; Wilschut, Jan; Nijman, Hans W.; Daemen, Toos

    2011-01-01

    Background: Regulatory T-cells (Treg) hamper immune responses elicited by cancer vaccines. Therefore, depletion of Treg is being used to improve the outcome of vaccinations. Methods: We studied whether an alphavirus vector-based immunotherapeutic vaccine changes the number and/or activity of Treg an

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

    Science.gov (United States)

    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.

  12. Safety and Efficacy of Subretinal Readministration of a Viral Vector in Large Animals to Treat Congenital Blindness

    Science.gov (United States)

    Amado, Defne; Mingozzi, Federico; Hui, Daniel; Bennicelli, Jeannette L.; Wei, Zhangyong; Chen, Yifeng; Bote, Erin; Grant, Rebecca L.; Golden, Jeffrey A.; Narfstrom, Kristina; Syed, Nasreen A.; Orlin, Stephen E.; High, Katherine A.; Maguire, Albert M.; Bennett, Jean

    2014-01-01

    Leber’s congenital amaurosis (LCA) is a group of severe inherited retinal degenerations that are symptomatic in infancy and lead to total blindness in adulthood. Recent clinical trials using recombinant adeno-associated virus serotype 2 (rAAV2) successfully reversed blindness in patients with LCA caused by RPE65 mutations after one subretinal injection. However, it was unclear whether treatment of the second eye in the same manner would be safe and efficacious, given the potential for a complicating immune response after the first injection. Here, we evaluated the immunological and functional consequences of readministration of rAAV2-hRPE65v2 to the contralateral eye using large animal models. Neither RPE65-mutant (affected; RPE65−/−) nor unaffected animals developed antibodies against the transgene product, but all developed neutralizing antibodies against the AAV2 capsid in sera and intraocular fluid after subretinal injection. Cell-mediated immune responses were benign, with only 1 of 10 animals in the study developing a persistent T cell immune response to AAV2, a response that was mediated by CD4+ T cells. Sequential bilateral injection caused minimal inflammation and improved visual function in affected animals. Thus, subretinal readministration of rAAV2 in animals is safe and effective, even in the setting of preexisting immunity to the vector, a parameter that has been used to exclude patients from gene therapy trials. PMID:20374996

  13. Limited efficacy of topical recombinant feline interferon-omega for treatment of cats with acute upper respiratory viral disease.

    Science.gov (United States)

    Ballin, Anne C; Schulz, Bianka; Helps, Christopher; Sauter-Louis, Carola; Mueller, Ralf S; Hartmann, Katrin

    2014-12-01

    Despite a lack of controlled studies confirming its efficacy, recombinant feline interferon-omega (rfeIFN-ω) is used in the treatment of feline upper respiratory tract disease (FURTD), which is usually caused by feline calicivirus (FCV) or feline herpesvirus-1 (FHV-1). The aims of the present study were to investigate whether administration of rfeIFN-ω improves clinical signs in cats with acute FURTD and whether this treatment reduces shedding of FCV. Thirty-seven cats affected with acute FURTD were recruited into a prospective, randomised, placebo-controlled, double-blinded clinical trial. The presence of FCV and/or FHV-1 was determined by performing quantitative polymerase chain reaction (qPCR) on oropharyngeal and conjunctival swabs. Cats were randomly assigned to treatment groups, receiving either placebo or rfeIFN-ω (2.5 MU/kg) subcutaneously, followed by 0.5 MU topically at 8-h intervals via the conjunctiva, intranasally, and orally for 21 days. All cats received additional treatment with antibiotics, expectorants, and inhalation of nebulised physiological saline with camomile. Clinical signs and FCV shedding were evaluated over 42 days. All cats demonstrated improvement in clinical signs during the course of the study, with no significant difference in any of the assessed variables when comparing the two groups. FCV copy numbers decreased more rapidly in cats receiving rfeIFN-ω. Treatment with rfeIFN-ω was not effective in ameliorating clinical signs of acute viral FURTD compared to placebo, but might accelerate a reduction in FCV load in infected cats.

  14. An efficient viral vector for functional genomic studies of Prunus fruit trees and its induced resistance to Plum pox virus via silencing of a host factor gene.

    Science.gov (United States)

    Cui, Hongguang; Wang, Aiming

    2017-03-01

    RNA silencing is a powerful technology for molecular characterization of gene functions in plants. A commonly used approach to the induction of RNA silencing is through genetic transformation. A potent alternative is to use a modified viral vector for virus-induced gene silencing (VIGS) to degrade RNA molecules sharing similar nucleotide sequence. Unfortunately, genomic studies in many allogamous woody perennials such as peach are severely hindered because they have a long juvenile period and are recalcitrant to genetic transformation. Here, we report the development of a viral vector derived from Prunus necrotic ringspot virus (PNRSV), a widespread fruit tree virus that is endemic in all Prunus fruit production countries and regions in the world. We show that the modified PNRSV vector, harbouring the sense-orientated target gene sequence of 100-200 bp in length in genomic RNA3, could efficiently trigger the silencing of a transgene or an endogenous gene in the model plant Nicotiana benthamiana. We further demonstrate that the PNRSV-based vector could be manipulated to silence endogenous genes in peach such as eukaryotic translation initiation factor 4E isoform (eIF(iso)4E), a host factor of many potyviruses including Plum pox virus (PPV). Moreover, the eIF(iso)4E-knocked down peach plants were resistant to PPV. This work opens a potential avenue for the control of virus diseases in perennial trees via viral vector-mediated silencing of host factors, and the PNRSV vector may serve as a powerful molecular tool for functional genomic studies of Prunus fruit trees.

  15. Bioengineered coagulation factor VIII enables long-term correction of murine hemophilia A following liver-directed adeno-associated viral vector delivery

    Directory of Open Access Journals (Sweden)

    Harrison C Brown

    2014-01-01

    Full Text Available Clinical data support the feasibility and safety of adeno-associated viral (AAV vectors in gene therapy applications. Despite several clinical trials of AAV-based gene transfer for hemophilia B, a unique set of obstacles impede the development of a similar approach for hemophilia A. These include (i the size of the factor VIII (fVIII transgene, (ii humoral immune responses to fVIII, (iii inefficient biosynthesis of human fVIII, and (iv AAV vector immunity. Through bioengineering approaches, a novel fVIII molecule, designated ET3, was developed and shown to improve biosynthetic efficiency 10- to 100-fold. In this study, the utility of ET3 was assessed in the context of liver-directed, AAV-mediated gene transfer into hemophilia A mice. Due to the large size of the expression cassette, AAV-ET3 genomes packaged into viral particles as partial genome fragments. Despite this potential limitation, a single peripheral vein administration of AAV-ET3 into immune-competent hemophilia A mice resulted in correction of the fVIII deficiency at lower vector doses than previously reported for similarly oversized AAV-fVIII vectors. Therefore, ET3 appears to improve vector potency and mitigate at least one of the critical barriers to AAV-based clinical gene therapy for hemophilia A.

  16. A novel recombinant adeno-associated virus vector packaging system with HSV-1 amplicon providing helper functions

    Institute of Scientific and Technical Information of China (English)

    舒跃龙; 吴小兵; 杨天忠; 贡惠宇; 侯云德; 颜子颖

    1999-01-01

    A novel packaging system for producing recombinant adeno-associated virus (rAAV) vector was described. Instead of the conventional method for rAAV production by two-plasmid co-transfection followed by superinfection with adenovirus 5, an HSV-1 amplicon system expressing AAV-2 rep and cap genes from their native promoters was used to provide complete helper functions for rAAV replicating and packaging. This HSV-1 ampticon stock consisted of two kinds of infectious HSV-1 virions, a replicating-defective HSV-1 amplicon pseudovirus harboring multi-copies of AAV-2 rep and cap gene and a temperature-sensitive HSV-1 mutant strain ts-KOS. High-titer rAAV was generated with this new packaging system. This packaging system gives a simple and scaleable process for rAAV production.

  17. An efficient viral vector for functional genomic studies of Prunus fruit trees and its induced resistance to Plum pox virus via silencing of a host factor gene

    OpenAIRE

    Cui, Hongguang; Wang, Aiming

    2016-01-01

    Summary RNA silencing is a powerful technology for molecular characterization of gene functions in plants. A commonly used approach to the induction of RNA silencing is through genetic transformation. A potent alternative is to use a modified viral vector for virus?induced gene silencing (VIGS) to degrade RNA molecules sharing similar nucleotide sequence. Unfortunately, genomic studies in many allogamous woody perennials such as peach are severely hindered because they have a long juvenile pe...

  18. Construction and expression of recombinant prokaryotic vector PGEX-4T-1-BC006151 correlated with multidrug resistant of lung adenocarcinoma

    Directory of Open Access Journals (Sweden)

    Xuejun LI

    2008-06-01

    Full Text Available Background and objective The drug resistance to chemotherapeutics is one of the important causes of low survival rate of lung cancer patients. Our previous study has demonstrated that BC006151 is a gene correlated with multidrug resistance of adenocarcinoma of lung. The aim of this study is to clone the BC006151 gene, and to construct recombinant prokaryotic vector PGEX-4T-1-BC006151, and to express it in E. coli BL21. Methods The primer was designed with restriction endonuclease position, then amplified BC006151 by RT-PCR, cleaved BC006151 cDNA and PGEX-4T-1 by BamH and EcoR I. linked it with PGEX-4T-1. Then the two fragments were linked by T4DNA. The post-linked vector was transformed into E. coli. DH5 and then expressed. Transformed the recombinant plasmids containing the correct clone into E. coli BL21 and protein was highly effective expressed. The production of GST fusion protein was identifisd by SDS-PAGE and Western-Blotting. Results The sequence of BC006151 was amplified and identified with that published in GenBank. The prokaryotic expression plasmid PGEX-4T-1-BC006151 was constructed successfully. And a new fusion protein with relative molecular mass of 13 KD was highly effectively expressed in E. coli. Conclusion The BC006151 gene correlated with multidrug resistance of lung adenocarcinoma is successfully cloned and expressed, which is helpful for the preparation of monoclonal and polyclonal antibodies.

  19. Stable Expression of Lentiviral Antigens by Quality-Controlled Recombinant Mycobacterium bovis BCG Vectors.

    Science.gov (United States)

    Hart, Bryan E; Asrican, Rose; Lim, So-Yon; Sixsmith, Jaimie D; Lukose, Regy; Souther, Sommer J R; Rayasam, Swati D G; Saelens, Joseph W; Chen, Ching-Ju; Seay, Sarah A; Berney-Meyer, Linda; Magtanong, Leslie; Vermeul, Kim; Pajanirassa, Priyadharshini; Jimenez, Amanda E; Ng, Tony W; Tobin, David M; Porcelli, Steven A; Larsen, Michelle H; Schmitz, Joern E; Haynes, Barton F; Jacobs, William R; Lee, Sunhee; Frothingham, Richard

    2015-07-01

    The well-established safety profile of the tuberculosis vaccine strain, Mycobacterium bovis bacille Calmette-Guérin (BCG), makes it an attractive vehicle for heterologous expression of antigens from clinically relevant pathogens. However, successful generation of recombinant BCG strains possessing consistent insert expression has encountered challenges in stability. Here, we describe a method for the development of large recombinant BCG accession lots which stably express the lentiviral antigens, human immunodeficiency virus (HIV) gp120 and simian immunodeficiency virus (SIV) Gag, using selectable leucine auxotrophic complementation. Successful establishment of vaccine stability stems from stringent quality control criteria which not only screen for highly stable complemented BCG ΔleuCD transformants but also thoroughly characterize postproduction quality. These parameters include consistent production of correctly sized antigen, retention of sequence-pure plasmid DNA, freeze-thaw recovery, enumeration of CFU, and assessment of cellular aggregates. Importantly, these quality assurance procedures were indicative of overall vaccine stability, were predictive for successful antigen expression in subsequent passaging both in vitro and in vivo, and correlated with induction of immune responses in murine models. This study has yielded a quality-controlled BCG ΔleuCD vaccine expressing HIV gp120 that retained stable full-length expression after 10(24)-fold amplification in vitro and following 60 days of growth in mice. A second vaccine lot expressed full-length SIV Gag for >10(68)-fold amplification in vitro and induced potent antigen-specific T cell populations in vaccinated mice. Production of large, well-defined recombinant BCG ΔleuCD lots can allow confidence that vaccine materials for immunogenicity and protection studies are not negatively affected by instability or differences between freshly grown production batches.

  20. In vitro activation and enzyme kinetic analysis of recombinant midgut serine proteases from the Dengue vector mosquito Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Isoe Jun

    2011-08-01

    Full Text Available Abstract Background The major Dengue virus vector Aedes aegypti requires nutrients obtained from blood meal proteins to complete the gonotrophic cycle. Although bioinformatic analyses of Ae. aegypti midgut serine proteases have provided evolutionary insights, very little is known about the biochemical activity of these digestive enzymes. Results We used peptide specific antibodies to show that midgut serine proteases are expressed as zymogen precursors, which are cleaved to the mature form after blood feeding. Since midgut protein levels are insufficient to purify active proteases directly from blood fed mosquitoes, we engineered recombinant proteins encoding a heterologous enterokinase cleavage site to permit generation of the bona fide mature form of four midgut serine proteases (AaET, AaLT, AaSPVI, AaSPVII for enzyme kinetic analysis. Cleavage of the chromogenic trypsin substrate BApNA showed that AaET has a catalytic efficiency (kcat/KM that is ~30 times higher than bovine trypsin, and ~2-3 times higher than AaSPVI and AaSPVII, however, AaLT does not cleave BApNA. To measure the enzyme activities of the mosquito midgut proteases using natural substrates, we developed a quantitative cleavage assay based on cleavage of albumin and hemoglobin proteins. These studies revealed that the recombinant AaLT enzyme was indeed catalytically active, and cleaved albumin and hemoglobin with equivalent efficiency to that of AaET, AaSPVI, and AaSPVII. Structural modeling of the AaLT and AaSPVI mature forms indicated that AaLT is most similar to serine collagenases, whereas AaSPVI appears to be a classic trypsin. Conclusions These data show that in vitro activation of recombinant serine proteases containing a heterologous enterokinase cleavage site can be used to investigate enzyme kinetics and substrate cleavage properties of biologically important mosquito proteases.

  1. Further development of a recombinant feline herpesvirus type 1 vector expressing feline calicivirus immunogenic antigen.

    Science.gov (United States)

    Yokoyama, N; Fujita, K; Damiani, A; Sato, E; Kurosawa, K; Miyazawa, T; Ishiguro, S; Mochizuki, M; Maeda, K; Mikami, T

    1998-06-01

    We previously reported the attenuation of thymidine kinase (TK) deficient mutant (C7301dlTK) of feline herpesvirus type 1 (FHV-1) in cats and the construction of a recombinant FHV-1 (C7301dlTK-Cap) inserted a precursor capsid gene of feline calcivirus (FCV) into the TK deletion locus of the C7301dlTK. In this study, we constructed a further improved recombinant FHV-1 (dlTK(gCp)-Cap) carrying a putative FHV-1 gC promoter sequence upstream of the FCV precursor capsid gene of the C7301dlTK-Cap. Growth kinetics of the dlTK(gCp)-Cap in cell cultures was similar to those of C7301dlTK and C7301dlTK-Cap. A strong expression of FCV immunogenic antigen by dlTK(gCp)-Cap was confirmed by indirect immunofluorescence and enzyme-linked immunosorbent assays. In addition, one vaccination with dlTK(gCp)-Cap protected cats more effective against subsequent virulent FCV challenge than that with C7301dlTK-Cap.

  2. Enhanced expression of HIV and SIV vaccine antigens in the structural gene region of live attenuated rubella viral vectors and their incorporation into virions.

    Science.gov (United States)

    Virnik, Konstantin; Ni, Yisheng; Berkower, Ira

    2013-04-19

    Despite the urgent need for an HIV vaccine, its development has been hindered by virus variability, weak immunogenicity of conserved epitopes, and limited durability of the immune response. For other viruses, difficulties with immunogenicity were overcome by developing live attenuated vaccine strains. However, there is no reliable method of attenuation for HIV, and an attenuated strain would risk reversion to wild type. We have developed rubella viral vectors, based on the live attenuated vaccine strain RA27/3, which are capable of expressing important HIV and SIV vaccine antigens. The rubella vaccine strain has demonstrated safety, immunogenicity, and long lasting protection in millions of children. Rubella vectors combine the growth and immunogenicity of live rubella vaccine with the antigenicity of HIV or SIV inserts. This is the first report showing that live attenuated rubella vectors can stably express HIV and SIV vaccine antigens at an insertion site located within the structural gene region. Unlike the Not I site described previously, the new site accommodates a broader range of vaccine antigens without interfering with essential viral functions. In addition, antigens expressed at the structural site were controlled by the strong subgenomic promoter, resulting in higher levels and longer duration of antigen expression. The inserts were expressed as part of the structural polyprotein, processed to free antigen, and incorporated into rubella virions. The rubella vaccine strain readily infects rhesus macaques, and these animals will be the model of choice for testing vector growth in vivo and immunogenicity.

  3. Recombinant Newcastle disease virus (NDV) with inserted gene coding for GM-CSF as a new vector for cancer immunogene therapy

    NARCIS (Netherlands)

    Janke, M.; Peeters, B.P.H.; Leeuw, de O.S.; Moormann, R.J.M.; Arnold, A.; Fournier, P.; Schirrmacher, V.

    2007-01-01

    This is the first report describing recombinant (rec) Newcastle disease virus (NDV) as vector for gene therapy of cancer. The gene encoding granulocyte/macrophage colony-stimulating factor (GM-CSF) was inserted as an additional transcription unit at two different positions into the NDV genome. The r

  4. Recombinant hybrid infectious hematopoietic necrosis virus (IHNV) carrying viral haemorrhagic septicaemia virus (VHSV) G or NV genes show different virulence properities

    DEFF Research Database (Denmark)

    Einer-Jensen, Katja; Biacchesi, S.; Stegmann, Anders

    Viral haemorrhagic septicaemia virus (VHSV) is the economically most important viral disease in European rainbow trout farming. The virus was introduced to fresh water farms in the 1950ies from a reservoir of VHSV in the marine environment. Isolates from wild marine fish and fresh water farms....... By a reverse genetics approach using the related novirrhabdovirus infectious hematopoietic necrosis virus (IHNV) as basis, four hybrid IHNV-VHSV variants were generated. These chimeric variants included substitution of the IHNV glyco(G) or nonstrutrual (Nv) protein with the corresponding G or Nv-protein from...... or fresh water VHSV. Recombinant IHNV gained higher virulence following substitution of the homologous G gene with the VHSV G gene, while the opposite was the case following substitution of the Nv gene. These findings suggest that higher virulence of VHSV compared to IHNV might be related to the G protein...

  5. Using double-stranded RNA to prevent in vitro and in vivo viral infections by recombinant baculovirus.

    Science.gov (United States)

    Valdes, Victor Julian; Sampieri, Alicia; Sepulveda, Jorge; Vaca, Luis

    2003-05-23

    Introduction of double-stranded RNA (dsRNA) into a wide variety of cells and organisms results in post-transcriptional depletion of the homologue endogenous mRNA. This well-preserved phenomenon known as RNA interference (RNAi) is present in evolutionarily diverse organisms such as plants, fungi, insects, metazoans, and mammals. Because the identification of the targeted mRNA by the RNAi machinery depends upon Watson-Crick base-pairing interactions, RNAi can be exquisitely specific. We took advantage of this powerful and flexible technique to demonstrate that selective silencing of genes essential for viral propagation prevents in vitro and in vivo viral infection. Using the baculovirus Autographa californica, a rapidly replicating and highly cytolytic double-stranded DNA virus that infects many different insect species, we show for the first time that introduction of dsRNA from gp64 and ie1, two genes essential for baculovirus propagation, results in prevention of viral infection in vitro and in vivo. This is the first report demonstrating the use of RNAi to inhibit a viral infection in animals. This inhibition was specific, because dsRNA from the polyhedrin promoter (used as control) or unrelated dsRNAs did not affect the time course of viral infection. The most relevant consequences from the present study are: 1) RNAi offers a rapid and efficient way to interfere with viral genes to assess the role of specific proteins in viral function and 2) using RNAi to interfere with viral genes essential for cell infection may provide a powerful therapeutic tool for the treatment of viral infections.

  6. Safety and Biodistribution Evaluation in Cynomolgus Macaques of rAAV2tYF-PR1.7-hCNGB3, a Recombinant AAV Vector for Treatment of Achromatopsia.

    Science.gov (United States)

    Ye, Guo-jie; Budzynski, Ewa; Sonnentag, Peter; Nork, T Michael; Miller, Paul E; Sharma, Alok K; Ver Hoeve, James N; Smith, Leia M; Arndt, Tara; Calcedo, Roberto; Gaskin, Chantelle; Robinson, Paulette M; Knop, David R; Hauswirth, William W; Chulay, Jeffrey D

    2016-03-01

    Applied Genetic Technologies Corporation (AGTC) is developing rAAV2tYF-PR1.7-hCNGB3, a recombinant adeno-associated viral (rAAV) vector expressing the human CNGB3 gene, for treatment of achromatopsia, an inherited retinal disorder characterized by markedly reduced visual acuity, extreme light sensitivity, and absence of color discrimination. We report here results of a study evaluating the safety and biodistribution of rAAV2tYF-PR1.7-hCNGB3 in cynomolgus macaques. Three groups of animals (n = 2 males and 2 females per group) received a subretinal injection in one eye of 300 μl containing either vehicle or rAAV2tYF-PR1.7-hCNGB3 at one of two concentrations (4 × 10(11) or 4 × 10(12) vector genomes/ml) and were evaluated over a 3-month period before being euthanized. Administration of rAAV2tYF-PR1.7-hCNGB3 was associated with a dose-related anterior and posterior segment inflammatory response that was greater than that observed in eyes injected with the vehicle control. Most manifestations of inflammation improved over time except that vitreous cells persisted in vector-treated eyes until the end of the study. One animal in the lower vector dose group was euthanized on study day 5, based on a clinical diagnosis of endophthalmitis. There were no test article-related effects on intraocular pressure, visual evoked potential responses, hematology or clinical chemistry parameters, or gross necropsy observations. Histopathological examination demonstrated minimal mononuclear infiltrates in all vector-injected eyes. Serum anti-AAV antibodies developed in all vector-injected animals. No animals developed antibodies to CNGB3. 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-PR1.7-hCNGB3 in clinical studies in patients with achromatopsia caused by CNGB3 mutations.

  7. Gene targeting with retroviral vectors

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, J.; Bernstein, A. (Toronto Univ., ON (Canada))

    1989-04-01

    The authors have designed and constructed integration-defective retroviral vectors to explore their potential for gene targeting in mammalian cells. Two nonoverlapping deletion mutants of the bacterial neomycin resistance (neo) gene were used to detect homologous recombination events between viral and chromosomal sequences. Stable neo gene correction events were selected at a frequency of approximately 1 G418/sup r/ cell per 3 x 10/sup 6/ infected cells. Analysis of the functional neo gene in independent targeted cell clones indicated that unintegrated retroviral linear DNA recombined with the target by gene conversion for variable distances into regions of nonhomology. In addition, transient neo gene correction events which were associated with the complete loss of the chromosomal target sequences were observed. These results demonstrated that retroviral vectors can recombine with homologous chromosomal sequences in rodent and human cells.

  8. Precocious flowering of juvenile citrus induced by a viral vector based on Citrus leaf blotch virus: a new tool for genetics and breeding.

    Science.gov (United States)

    Velázquez, Karelia; Agüero, Jesús; Vives, María C; Aleza, Pablo; Pina, José A; Moreno, Pedro; Navarro, Luis; Guerri, José

    2016-10-01

    The long juvenile period of citrus trees (often more than 6 years) has hindered genetic improvement by traditional breeding methods and genetic studies. In this work, we have developed a biotechnology tool to promote transition from the vegetative to the reproductive phase in juvenile citrus plants by expression of the Arabidopsis thaliana or citrus FLOWERING LOCUS T (FT) genes using a Citrus leaf blotch virus-based vector (clbvINpr-AtFT and clbvINpr-CiFT, respectively). Citrus plants of different genotypes graft inoculated with either of these vectors started flowering within 4-6 months, with no alteration of the plant architecture, leaf, flower or fruit morphology in comparison with noninoculated adult plants. The vector did not integrate in or recombine with the plant genome nor was it pollen or vector transmissible, albeit seed transmission at low rate was detected. The clbvINpr-AtFT is very stable, and flowering was observed over a period of at least 5 years. Precocious flowering of juvenile citrus plants after vector infection provides a helpful and safe tool to dramatically speed up genetic studies and breeding programmes. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  9. Self-assembled BolA-like amphiphilic peptides as viral-mimetic gene vectors for cancer cell targeted gene delivery.

    Science.gov (United States)

    Chen, Jing-Xiao; Xu, Xiao-Ding; Yang, Shuo; Yang, Juan; Zhuo, Ren-Xi; Zhang, Xian-Zheng

    2013-01-01

    In this study, two types of BolA-like amphiphilic peptides with dual ligands comprising a tumor-targeting moiety of RGD sequence and a cell-penetrating moiety of R8 sequence are designed and synthesized as gene vectors. The BolA-structural peptide carriers can self-assemble into spherical nanoparticles with a hydrophilic core and shell, which are similar to the viral capsid and can bind plasmid DNA in an aqueous medium to form viral-mimetic complexes. It is found that the BolA-like dual ligands system exhibits significantly enhanced gene expression in both HeLa and 293T cell lines, as compared with poly(ethylenimine) PEI. These BolA-like amphiphilic peptides are promising in clinical trials of gene therapy. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Different HIV pox viral vector-based vaccines and adjuvants can induce unique antigen presenting cells that modulate CD8 T cell avidity.

    Science.gov (United States)

    Trivedi, Shubhanshi; Jackson, Ronald J; Ranasinghe, Charani

    2014-11-01

    The lung-derived dendritic cell (LDC) recruitment following intranasal (i.n.) vaccination of different poxviral vector-based vaccines/adjuvants were evaluated to decipher how these factors influenced CD8(+) T cell avidity. Compared to the standard i.n. recombinant fowlpox virus (FPV)-HIV vaccination, the FPV-HIV IL-13Rα2 or IL-4Rα antagonist adjuvanted vaccines that induced higher avidity CD8(+) T cells, also recruited significantly elevated MHCII(+) CD11c(+) CD11b(+) CD103(-) CD64(-) MAR-1(-) conventional DC (cDCs) to the lung mucosae (hierarchy: IL-4R antagonist>IL-13Rα2>unadjuvanted). In contrast, elevated CD11b(-) CD103(+) LDCs were detected in animals that received recombinant HIV vaccinia virus (rVV) or Modified Vaccinia Ankara virus (MVA) vector-based vaccines. Adoptive transfer studies indicated that CD11b(-) CD103(+) LDCs significantly dampened HIV-specific CD8(+) T cell avidity compared to CD11b(+) CD103(-) LDCs. Collectively; our observations revealed that rFPV vector prime and transient inhibition of IL-4/IL-13 at the vaccination site favoured the recruitment of unique LDCs, associated with the induction of high quality immunity.

  11. Self-entanglement of long linear DNA vectors using transient non-B-DNA attachment points: a new concept for improvement of non-viral therapeutic gene delivery.

    Science.gov (United States)

    Tolmachov, Oleg E

    2012-05-01

    The cell-specific and long-term expression of therapeutic transgenes often requires a full array of native gene control elements including distal enhancers, regulatory introns and chromatin organisation sequences. The delivery of such extended gene expression modules to human cells can be accomplished with non-viral high-molecular-weight DNA vectors, in particular with several classes of linear DNA vectors. All high-molecular-weight DNA vectors are susceptible to damage by shear stress, and while for some of the vectors the harmful impact of shear stress can be minimised through the transformation of the vectors to compact topological configurations by supercoiling and/or knotting, linear DNA vectors with terminal loops or covalently attached terminal proteins cannot be self-compacted in this way. In this case, the only available self-compacting option is self-entangling, which can be defined as the folding of single DNA molecules into a configuration with mutual restriction of molecular motion by the individual segments of bent DNA. A negatively charged phosphate backbone makes DNA self-repulsive, so it is reasonable to assume that a certain number of 'sticky points' dispersed within DNA could facilitate the entangling by bringing DNA segments into proximity and by interfering with the DNA slipping away from the entanglement. I propose that the spontaneous entanglement of vector DNA can be enhanced by the interlacing of the DNA with sites capable of mutual transient attachment through the formation of non-B-DNA forms, such as interacting cruciform structures, inter-segment triplexes, slipped-strand DNA, left-handed duplexes (Z-forms) or G-quadruplexes. It is expected that the non-B-DNA based entanglement of the linear DNA vectors would consist of the initial transient and co-operative non-B-DNA mediated binding events followed by tight self-ensnarement of the vector DNA. Once in the nucleoplasm of the target human cells, the DNA can be disentangled by type II

  12. A fragmented adeno-associated viral dual vector strategy for treatment of diseases caused by mutations in large genes leads to expression of hybrid transcripts

    Science.gov (United States)

    McClements, Michelle E.; Charbel Issa, Peter; Blouin, Véronique; MacLaren, Robert E.

    2017-01-01

    Objective Dual vector AAV systems are being utilised to enable gene therapy for disorders in which the disease gene is too large to fit into a single capsid. Fragmented adeno-associated viral (fAAV) vectors containing single inverted terminal repeat truncated transgenes have been considered as one such gene replacement strategy. Here we aim to add to the current understanding of the molecular mechanisms employed by fAAV dual vector systems. Methods Oversized (>8kb) transgene constructs containing ABCA4 coding sequence were packaged as truncated fragments <5kb in size into various AAV serotypes. In vitro transductions with these fAAV vector preparations were conducted with mRNA and protein expression products assessed by way of RT-PCR, qPCR and western blot techniques. Results Transductions with fAAV vector preparations yielded ABCA4 mRNA, but did not generate detectable levels of protein. Sequencing of the transcript population revealed the presence of full length ABCA4 CDS with additional hybrid ABCA4 variants, indicating truncated transgenes without regions of overlap were joining and forming stable hybrid transgenes. In contrast, an ABCA4 overlapping dual vector system (OV) with a defined complementary region generated only full length mRNA transcripts plus detectable ABCA4 protein. Conclusion Despite previous success shown with the fAAV approach, the lack of repeatability and identification of stable hybrid transcripts capable of protein production suggests there is more refinement required before considering this approach in a clinical setting. PMID:28239514

  13. Postexposure Protection Against Marburg Haemorrhagic Fever with Recombinant Vesicular Stomatitis Virus Vectors in Non-Human Primates: An Efficacy Assessment

    Science.gov (United States)

    2006-04-29

    virus (MARV). We aimed to test the effi cacy of a replication -competent vaccine based on attenuated recombinant vesicular stomatitis virus (rVSV...including vaccines based on recombinant adenoviruses12,13 and recombinant alphaviruses .8 We previously described the generation and assessment of a live...such as Marburg virus (MARV). We aimed to test the efficacy of a replication -competent vaccine based on attenuated recombinant vesicular stomatitis

  14. Generation of recombinant bacillus Calmette-Guérin and Mycobacterium smegmatis expressing BfpA and intimin as vaccine vectors against enteropathogenic Escherichia coli.

    Science.gov (United States)

    Vasconcellos, Halyka Luzorio Franzotti; Scaramuzzi, Karina; Nascimento, Ivan Pereira; Da Costa Ferreira, Jorge M; Abe, Cecilia M; Piazza, Roxane M F; Kipnis, Andre; Dias da Silva, Wilmar

    2012-09-07

    Enteropathogenic Escherichia coli (EPEC) is an important cause of diarrhea in children. EPEC adheres to the intestinal epithelium and causes attaching and effacing (A/E) lesions. Recombinant Mycobacterium smegmatis (Smeg) and Mycobacterium bovis BCG strains were constructed to express either BfpA or intimin. The entire bfpA gene and a portion of the intimin gene were amplified by PCR from EPEC genomic DNA and inserted into the pMIP12 vector at the BamHI/KpnI sites. The pMIP_bfpA and pMIP_intimin vectors were introduced separately into Smeg and BCG. Recombinant clones were selected based on kanamycin resistance and designated rSmeg_pMIP_(bfpA or intimin) and rBCG_pMIP_(bfpA or intimin). The expression of bfpA and intimin was detected by Immunoblotting using polyclonal anti-BfpA and anti-intimin antibodies. The immunogenicity of these proteins was assessed in C57BL/6 mice by assaying the feces and serum for the presence of anti-BfpA and anti-intimin IgA and IgG antibodies. TNF-α and INF-γ were produced in vitro by spleen cells from mice immunized with recombinant BfpA, whereas TNF-γ was produced in mice immunized with recombinant intimin. The adhesion of EPEC (E2348/69) to HEp-2 target cells was blocked by IgA or IgG antibodies from mice immunized with recombinant BfpA or intimin but not by antibodies from non-immunized mice. Immunogenic non-infectious vectors containing relevant EPEC virulence genes may be promising vaccine candidates.

  15. High-level recombinant protein production in CHO cells using an adenoviral vector and the cumate gene-switch.

    Science.gov (United States)

    Gaillet, Bruno; Gilbert, Rénald; Amziani, Rachid; Guilbault, Claire; Gadoury, Christine; Caron, Antoine W; Mullick, Alaka; Garnier, Alain; Massie, Bernard

    2007-01-01

    To facilitate and accelerate the production of eukaryotic proteins with correct post-translational modifications, we have developed a protein production system based on the transduction of Chinese hamster ovary (CHO) cells using adenovirus vectors (AdVs). We have engineered a CHO cell line (CHO-cTA) that stably expresses the transactivator (cTA) of our newly developed cumate gene-switch transcription system. This cell line is adapted to suspension culture and can grow in serum-free and protein-free medium. To increase the transduction level of AdVs, we have also generated a cell line (CHO-cTA-CAR) that expresses additional amounts of the coxackievirus and adenovirus receptor (CAR) on its surface. Recombinant protein production was tested using an AdV carrying the secreted alkaline phosphatase (SEAP) under the control of the CR5 promoter, which is strongly and specifically activated by binding to cTA. The SEAP expression was linked to the expression of the green fluorescent protein (GFP) through an internal ribosome entry site (IRES) to facilitate titration of the AdV. We monitored SEAP expression on a daily basis for 9 days after transduction of CHO-cTA and CHO-cTA-CAR using different quantities of AdVs at 37 and 30 degrees C. Incubation at the latter temperature increased the production of SEAP at least 10-fold, and the presence of CAR increased the transduction level of the AdV. Maximum SEAP production (63 mg/L) was achieved at 6-7 days post-infection at 30 degrees C by transducing CHO-cTA-CAR with 500 infectious particles/cell. Because numerous AdVs can now be generated within a few weeks and large-scale production of AdVs is now a routine procedure, this system could be used to produce rapidly milligram quantities of a battery of recombinant proteins as well as for large-scale protein production.

  16. Oral vaccination with a recombinant Salmonella vaccine vector provokes systemic HIV-1 subtype C Gag-specific CD4+ Th1 and Th2 cell immune responses in mice

    Directory of Open Access Journals (Sweden)

    Williamson Anna-Lise

    2009-06-01

    Full Text Available Abstract Background Recombinant Salmonella vaccine vectors may potentially be used to induce specific CD4+ T cell responses against foreign viral antigens. Such immune responses are required features of vaccines against pathogens such as human immunodeficiency virus type 1 (HIV-1. The aim of this study was to investigate the induction of systemic HIV-1-specific CD4+ T helper (Th responses in mice after oral immunization with a live attenuated Salmonella vaccine vector that expressed HIV-1 subtype C Gag. Groups of BALB/c mice were vaccinated orally three times (4 weeks apart with this recombinant Salmonella. At sacrifice, 28 days after the last immunization, systemic CD4+ Th1 and Th2 cytokine responses were evaluated by enzyme-linked immunospot assay and cytometric bead array. HIV-1 Gag-specific IgG1 and IgG2a humoral responses in the serum were determined by enzyme-linked immunosorbent assay. Results Mice vaccinated with the recombinant Salmonella elicited both HIV-1-specific Th1 (interferon-gamma (IFN-γ and tumour necrosis factor-alpha (TNF-α and Th2 (interleukin-4 (IL-4 and interleukin-5 (IL-5 cytokine responses. The vaccine induced 70 (IFN-γ spot-forming units (SFUs/10e6 splenocytes and 238 IL-4 SFUs/10e6 splenocytes. Splenocytes from vaccinated mice also produced high levels of Th1 and Th2 cytokines upon stimulation with a Gag CD4 peptide. The levels of IFN-γ, TNF-α, IL-4 and IL-5 were 7.5-, 29.1-, 26.2- and 89.3-fold above the background, respectively. Both HIV-1 Gag-specific IgG1 and IgG2a antibodies were detected in the sera of vaccinated mice. Conclusion The study highlights the potential of orally-delivered attenuated Salmonella as mucosal vaccine vectors for HIV-1 Subtype C Gag to induce Gag-specific CD4+ Th1 and Th2 cellular immune responses and antibodies which may be important characteristics required for protection against HIV-1 infection.

  17. Immunogenicity and protective efficacy of recombinant Modified Vaccinia virus Ankara candidate vaccines delivering West Nile virus envelope antigens

    NARCIS (Netherlands)

    Volz, Asisa; Lim, Stephanie; Kaserer, Martina; Pijlman, Gorben P.

    2016-01-01

    West Nile virus (WNV) cycles between insects and wild birds, and is transmitted via mosquito vectors to horses and humans, potentially causing severe neuroinvasive disease. Modified Vaccinia virus Ankara (MVA) is an advanced viral vector for developing new recombinant vaccines against infectious

  18. Immunogenicity and protective efficacy of recombinant Modified Vaccinia virus Ankara candidate vaccines delivering West Nile virus envelope antigens

    NARCIS (Netherlands)

    Volz, Asisa; Lim, Stephanie; Kaserer, Martina; Pijlman, Gorben P.

    2016-01-01

    West Nile virus (WNV) cycles between insects and wild birds, and is transmitted via mosquito vectors to horses and humans, potentially causing severe neuroinvasive disease. Modified Vaccinia virus Ankara (MVA) is an advanced viral vector for developing new recombinant vaccines against infectious

  19. Protective immunization of horses with a recombinant canarypox virus vectored vaccine co-expressing genes encoding the outer capsid proteins of African horse sickness virus.

    Science.gov (United States)

    Guthrie, Alan J; Quan, Melvyn; Lourens, Carina W; Audonnet, Jean-Christophe; Minke, Jules M; Yao, Jiansheng; He, Ling; Nordgren, Robert; Gardner, Ian A; Maclachlan, N James

    2009-07-16

    We describe the development and preliminary characterization of a recombinant canarypox virus vectored (ALVAC) vaccine for protective immunization of equids against African horse sickness virus (AHSV) infection. Horses (n=8) immunized with either of two concentrations of recombinant canarypox virus vector (ALVAC-AHSV) co-expressing synthetic genes encoding the outer capsid proteins (VP2 and VP5) of AHSV serotype 4 (AHSV-4) developed variable titres (horse immunized with a commercial recombinant canarypox virus vectored vaccine expressing the haemagglutinin genes of two equine influenza H3N8 viruses was seronegative to AHSV and following infection with virulent AHSV-4 developed pyrexia, thrombocytopenia and marked oedema of the supraorbital fossae typical of the "dikkop" or cardiac form of African horse sickness. AHSV was detected by virus isolation and quantitative reverse transcriptase polymerase chain reaction in the blood of the control horse from 8 days onwards after challenge infection whereas AHSV was not detected at any time in the blood of the ALVAC-AHSV vaccinated horses. The control horse seroconverted to AHSV by 2 weeks after challenge infection as determined by both virus neutralization and ELISA assays, whereas six of eight of the ALVAC-AHSV vaccinated horses did not seroconvert by either assay following challenge infection with virulent AHSV-4. These data confirm that the ALVAC-AHSV vaccine will be useful for the protective immunization of equids against African horse sickness, and avoids many of the problems inherent to live-attenuated AHSV vaccines.

  20. Foamy viral vector integration sites in SCID-repopulating cells after MGMTP140K-mediated in vivo selection.

    Science.gov (United States)

    Olszko, M E; Adair, J E; Linde, I; Rae, D T; Trobridge, P; Hocum, J D; Rawlings, D J; Kiem, H-P; Trobridge, G D

    2015-07-01

    Foamy virus (FV) vectors are promising for hematopoietic stem cell (HSC) gene therapy but preclinical data on the clonal composition of FV vector-transduced human repopulating cells is needed. Human CD34(+) human cord blood cells were transduced with an FV vector encoding a methylguanine methyltransferase (MGMT)P140K transgene, transplanted into immunodeficient NOD/SCID IL2Rγ(null) mice, and selected in vivo for gene-modified cells. The retroviral insertion site profile of repopulating clones was examined using modified genomic sequencing PCR. We observed polyclonal repopulation with no evidence of clonal dominance even with the use of a strong internal spleen focus forming virus promoter known to be genotoxic. Our data supports the use of FV vectors with MGMTP140K for HSC gene therapy but also suggests additional safety features should be developed and evaluated.

  1. In vitro construction of a recombinant human embryonic brain-derived neurotrophin-4 gene and pEGFP-N1 vector

    Institute of Scientific and Technical Information of China (English)

    Jintao Li; Qi Yan; Xingbao Zhu; Dan Xu; Tinghua Wang; Huatang Zhang; Jia Liu

    2009-01-01

    BACKGROUND: Neurotrophin-4 (NT-4) can promote neuronal growth, development, differentiation, maturation, and survival. NT-4 can also improve recovery and regeneration of injured neurons, but cannot pass through the blood-brain barrier, which limits its activity in the central nervous system. Delivering NT-4 into the central nervous system via cells or vectors may have therapeutic benefit.OBJECTIVE: To construct a recombinant vector with a human embryonic brain-derived NT-4 gene and pEGFP-N1.DESIGN, TIME AND SETTING: Neural genetic engineering experiment. The study was performed at the Neuroscience Institute of Kunming Medical College between October 2007 and March 2008.MATERIALS: The pEGFP-N1 plasmid vector was provided by Kunming Institute of Zoology, Chinese Academy of Sciences; embryonic brain tissues were provided by the First Affiliated Hospital of Kunming Medical College. TRIzol RNA extraction Kit was purchased from Sigma (USA), One Step RNA PCR Kit (AMV) etc. were from Takara (Dalian, China).METHODS: Total RNA was extracted from human embryonic brain tissues using Trizol. The agarose gel electrophoresis showed two bands: 18 S and 28 S, which were essential subunits of total RNA. The human NT-4 DNA was obtained via RT-PCR and inserted into the pEGFP-N1 vector using ligation and transformation reaction.MAIN OUTCOME MEASURES: The sequencing results of the DNA in the recombinant of NT-4-pEGFP-N1.RESULTS: The NT-4-pEGFP-N1 vector was sequence-verified and showed the expected molecular weight.CONCLUSION: The recombinant of NT-4-pEGFP-N1 was constructed successfully in vitro.

  2. [The vaccines based on the replicon of the venezuelan equine encephalomyelitis virus against viral hemorrhagic fevers].

    Science.gov (United States)

    Petrov, A A; Plekhanova, T M; Sidorova, O N; Borisevich, S V; Makhlay, A A

    2015-01-01

    The status of the various recombinant DNA and RNA-derived candidate vaccines, as well as the Venezuelan equine encephalomyelitis virus (VEEV) replicon vaccine system against extremely hazardous viral hemorrhagic fevers, were reviewed. The VEEV-based replication-incompetent vectors offer attractive features in terms of safety, high expression levels of the heterologous viral antigen, tropism to dendritic cells, robust immune responses, protection efficacy, low potential for pre-existing anti-vector immunity and possibility of engineering multivalent vaccines were tested. These features of the VEEV replicon system hold much promise for the development of new generation vaccine candidates against viral hemorrhagic fevers.

  3. Surface Modification of Biomimetic PLGA-(ASP-PEG) Matrix with RGD-Containing Peptide: a New Non-Viral Vector for Gene Transfer and Tissue Engineering

    Institute of Scientific and Technical Information of China (English)

    GUO Xiaodong; SONG Yulin; ZHENG Qixin; YANG Shuhua; SHAO Zengwu; WU Yongchao; HAO Jie; QUAN Daping

    2006-01-01

    RGD-containing peptide (K16-GRGDSPC), characterized as non-viral gene vectors, was fabricated to modify the surface of PLGA-[ASP-PEG] matrix, which offered the foundation for gene transfer with porous matrix of gene activated later. Peptide was synthesized and matrix was executed into chips A,B and chip C. Chip C was regarded as control. Chips A and B were reacted with cross-linker. Then chip A was reacted with peptide. MS and HPLC were used to detect the MW and purity of peptide. Sulphur, existing on the surface of biomaterials, was detected by XPS. The purity of un-reacted peptide in residual solution was detected by a spectrophotometer. HPLC shows that the peptide purity was 94%-95%, and MS shows that the MW was 2 741.3307. XPS reveals that the binding energy of sulphur was 164 eV and the ratio of carbon to sulphur (C/S) was 99.746∶0.1014 in reacted chip A. The binding energy of sulphur in reacted chip B was 164 eV and 162 eV, C/S was 99.574∶0.4255, and there was no sulphur in chip C. Peptide was manufactured and linked to the surface of biomimetic and 3-D matrix, which offered the possibilities for gene transfer and tissue engineering with this new kind of non-viral gene vector.

  4. In vitro effect of p21WAF-1/CIP1 gene on growth of human glioma cells mediated by EGFR targeted non-viral vector GE7 system

    Institute of Scientific and Technical Information of China (English)

    陈永新; 许秀兰; 张光霁; 王韦; 金海英; 卢亦成; 朱诚; 顾健人

    2003-01-01

    Objective: To construct the EGFR targeted non-viral vector GE7 system and explore the in vitro effect of p21WAF-1/CIP1 gene on growth of human glioma cells mediated by the GE7 system. Methods: The EGFR targeted non-viral vector GE7 gene delivery system was constructed. The malignant human glioma cell line U251MG was transfected in vitro with β-galactosidase gene(reporter gene) and p21WAF-1/CIP1 gene (therapeutic gene) using the GE7 system. By means of X-gal staining, MTS and FACS, the transfection efficiency of exogenous gene and apoptosis rate of tumor cells were examined. The expression of p21WAF-1/CIP1 gene in transfected U251MG cell was examined by immunohistochemistry staining. Results: The highest transfer rate of exogenous gene was 70%. After transfection with p21WAF-1/CIP1 gene, the expression of WAF-1 increased remarkably and steadily; the growth of U251MG cells were inhibited evidently. FACS examination showed G1 arrest. The average apoptosis rate was 25.2%. Conclusion: GE7 system has the ability to transfer exogenous gene to targeted cells efficiently, and expression of p21WAF-1/CIP1 gene can induce apoptosis of glioma cell and inhibit its growth.

  5. Overcoming inefficient secretion of recombinant VEGF-C in baculovirus expression vector system by simple purification of the protein from cell lysate.

    Science.gov (United States)

    Klaus, Tomasz; Kulesza, Małgorzata; Bzowska, Monika; Wyroba, Barbara; Kilarski, Witold W; Bereta, Joanna

    2015-06-01

    The first reports about successfully expressed recombinant proteins with the use of a baculovirus vector were published over 30years ago. Despite the long time of refining this expression system, early problems with the production of baculovirus-derived secretory proteins are still not satisfactorily solved. The high expression level driven by baculoviral promoters often does not result in the desired yield of secreted recombinant proteins, which frequently accumulate inside insect cells and are only partially processed. During our attempts to produce vascular endothelial growth factor C (VEGF-C) with the use of a baculovirus vector we also faced an inefficient secretion of the recombinant protein to culture medium. We were not able to improve the outcome and obtain an acceptable concentration of VEGF-C in the medium by changing the culture conditions or utilizing different signal peptides. However, as a significant amount of native VEGF-C was detected inside the baculovirus-infected cells, we developed a simple method to purify recombinant, glycosylated VEGF-C from a lysate of the cells. The presented results indicate that the lack of a secretory protein in the insect cell culture medium after baculovirus infection does not necessarily signify failure in the production of the protein. As demonstrated by us and contrary to generally accepted views, the lysate of baculovirus-infected cells may constitute a valuable source of the biologically active, secretory protein.

  6. Vaccination against Very Virulent Infectious Bursal Disease Virus Using Recombinant T4 Bacteriophage Displaying Viral Protein VP2

    Institute of Scientific and Technical Information of China (English)

    Yong-Chang CAO; Quan-Cheng SHI; Jing-Yun MA; Qing-Mei XIE; Ying-Zuo BI

    2005-01-01

    In order to develop a desirable inexpensive, effective and safe vaccine against the very virulent infectious bursal disease virus (vvIBDV), we tried to take advantage of the emerging T4 bacteriophage surface protein display system. The major immunogen protein VP2 from the vvIBDV strain HK46 was fused to the nonessential T4 phage surface capsid protein, a small outer capsid (SOC) protein, resulting in the 49 kDa SOC-VP2 fusion protein, which was verified by sodium dodecylsulfate polyacrylamide gel electrophoresis and Western blot. Immunoelectromicroscopy showed that the recombinant VP2 protein was successfully displayed on the surface of the T4 phage. The recombinant VP2 protein is antigenic and showed reactivities to various monoclonal antibodies (mAbs) against IBDV, whereas the wild-type phage T4 could not react to any mAb. In addition, the recombinant VP2 protein is immunogenic and elicited specific antibodies in immunized specific pathogen free (SPF) chickens. More significantly, immunization of SPF chickens with the recombinant T4-VP2 phage protected them from infection by the vvIBDV strain HK46. When challenged with the vvIBDV strain HK46 at a dose of 100 of 50% lethal dose (LD50) per chicken 4 weeks after the booster was given, the group vaccinated with the T4-VP2 recombinant phage showed no clinical signs of disease or death, wh ereas the unvaccinated group and the group vaccinated with the wild-type T4phage exhibited 100% clinical signs of disease and bursal damages, and 30%-40% mortality. Collectively,the data herein showed that the T4-displayed VP2 protein might be an inexpensive, effective and safe vaccine candidate against vvIBDV.

  7. The impact of AAV capsid-specific T cell responses on design and outcome of clinical gene transfer trials with recombinant AAV vectors - an evolving controversy.

    Science.gov (United States)

    Ertl, Hildegund Cj; High, Katherine A

    2017-01-02

    Recombinant adenovirus-associated (rAAV) vectors due to their ease of construction, wide tissue tropism and lack of pathogenicity remain at the forefront for long-term gene replacement therapy. In spite of very encouraging pre-clinical results, clinical trials were initially unsuccessful; expression of the rAAV vector-delivered therapeutic protein was transient. Loss of expression was linked to an expansion of AAV capsid-specific T cell responses, leading to the hypothesis that rAAV vectors recall pre-existing memory T cells that had been induced by natural infections with AAV together with a helper virus. Although this was hotly debated at first, AAV capsid-specific T cell responses were observed in several gene transfer trials that used high doses of rAAV vectors. Subsequent trials designed to circumvent these T cell responses through the use of immunosuppressive drugs, rAAV vectors based on rare serotypes or modified to allow for therapeutic levels of the transgene product at low, non-immunogenic vector doses are now successful in correcting debilitating diseases.

  8. Combining viral vectored and protein-in-adjuvant vaccines against the blood-stage malaria antigen AMA1: report on a phase 1a clinical trial.

    Science.gov (United States)

    Hodgson, Susanne H; Choudhary, Prateek; Elias, Sean C; Milne, Kathryn H; Rampling, Thomas W; Biswas, Sumi; Poulton, Ian D; Miura, Kazutoyo; Douglas, Alexander D; Alanine, Daniel Gw; Illingworth, Joseph J; de Cassan, Simone C; Zhu, Daming; Nicosia, Alfredo; Long, Carole A; Moyle, Sarah; Berrie, Eleanor; Lawrie, Alison M; Wu, Yimin; Ellis, Ruth D; Hill, Adrian V S; Draper, Simon J

    2014-12-01

    The development of effective vaccines against difficult disease targets will require the identification of new subunit vaccination strategies that can induce and maintain effective immune responses in humans. Here we report on a phase 1a clinical trial using the AMA1 antigen from the blood-stage Plasmodium falciparum malaria parasite delivered either as recombinant protein formulated with Alhydrogel adjuvant with and without CPG 7909, or using recombinant vectored vaccines--chimpanzee adenovirus ChAd63 and the orthopoxvirus MVA. A variety of promising "mixed-modality" regimens were tested. All volunteers were primed with ChAd63, and then subsequently boosted with MVA and/or protein-in-adjuvant using either an 8- or 16-week prime-boost interval. We report on the safety of these regimens, as well as the T cell, B cell, and serum antibody responses. Notably, IgG antibody responses primed by ChAd63 were comparably boosted by AMA1 protein vaccine, irrespective of whether CPG 7909 was included in the Alhydrogel adjuvant. The ability to improve the potency of a relatively weak aluminium-based adjuvant in humans, by previously priming with an adenoviral vaccine vector encoding the same antigen, thus offers a novel vaccination strategy for difficult or neglected disease targets when access to more potent adjuvants is not possible.

  9. Viral recombination blurs taxonomic lines: examination of single-stranded DNA viruses in a wastewater treatment plant

    Directory of Open Access Journals (Sweden)

    Victoria M. Pearson

    2016-10-01

    Full Text Available Understanding the structure and dynamics of microbial communities, especially those of economic concern, is of paramount importance to maintaining healthy and efficient microbial communities at agricultural sites and large industrial cultures, including bioprocessors. Wastewater treatment plants are large bioprocessors which receive water from multiple sources, becoming reservoirs for the collection of many viral families that infect a broad range of hosts. To examine this complex collection of viruses, full-length genomes of circular ssDNA viruses were isolated from a wastewater treatment facility using a combination of sucrose-gradient size selection and rolling-circle amplification and sequenced on an Illumina MiSeq. Single-stranded DNA viruses are among the least understood groups of microbial pathogens due to genomic biases and culturing difficulties, particularly compared to the larger, more often studied dsDNA viruses. However, the group contains several notable well-studied examples, including agricultural pathogens which infect both livestock and crops (Circoviridae and Geminiviridae, and model organisms for genetics and evolution studies (Microviridae. Examination of the collected viral DNA provided evidence for 83 unique genotypic groupings, which were genetically dissimilar to known viral types and exhibited broad diversity within the community. Furthermore, although these genomes express similarities to known viral families, such as Circoviridae, Geminiviridae, and Microviridae, many are so divergent that they may represent new taxonomic groups. This study demonstrated the efficacy of the protocol for separating bacteria and large viruses from the sought after ssDNA viruses and the ability to use this protocol to obtain an in-depth analysis of the diversity within this group.

  10. Non-viral S/MAR vectors replicate episomally in vivo when provided with a selective advantage.

    Science.gov (United States)

    Wong, S P; Argyros, O; Coutelle, C; Harbottle, R P

    2011-01-01

    The ideal gene therapy vector should enable persistent expression without the limitations of safety and reproducibility. We previously reported that a prototype plasmid vector, containing a scaffold matrix attachment region (S/MAR) domain and the luciferase reporter gene, showed transgene expression for at least 6 months following a single administration to MF1 mice. Following partial hepatectomy of the animals, however, we found no detectable vector replication and subsequent propagation in vivo. To overcome this drawback, we have now developed an in vivo liver selection strategy by which liver cells transfected with an S/MAR plasmid are provided with a survival advantage over non-transfected cells. This allows an enrichment of vectors that are capable of replicating and establishing themselves as extra-chromosomal entities in the liver. Accordingly, a novel S/MAR plasmid encoding the Bcl-2 gene was constructed; Bcl-2 expression confers resistance against apoptosis-mediated challenges by the Fas-activating antibody Jo2. Following hydrodynamic delivery to the livers of mice and frequent Jo2 administrations, we demonstrate that this Bcl-luciferase S/MAR plasmid is indeed capable of providing sustained luciferase reporter gene expression for over 3 months and that this plasmid replicates as an episomal entity in vivo. These results provide proof-of-principle that S/MAR vectors are capable of preventing transgene silencing, are resistant to integration and are able to confer mitotic stability in vivo when provided with a selective advantage.

  11. Research and development of cancer-targeting vectors: An exploration on oncotropism and oncosuppression of autonomous parvoviruses

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Autonomous parvoviruses are single-stranded DNA viruses with a genome size of about 5 kb. They are characterized by their oncotropism and oncosuppression to the hosts. After infection the viral genes are not integrated into the chromosome of host cells. Autonomous parvoviruses could be used as potential vectors carrying heterologous therapeutic genes for the construction of recombinant autonomous parvoviruses. The specific advantages of these viral vectors to cancer gene therapy are discussed.

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

    Science.gov (United States)

    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

  13. [Recombination and identification of sense and antisence CyclinD1 eukaryotic expression vectors and the effects of the vectors on the proliferation of airway smooth muscle cell in asthmatic rats].

    Science.gov (United States)

    Qiao, Li-Fen; Xu, Yong-Jian; Liu, Xian-Sheng; Xie, Jun-Gang; Du, Chun-Ling; Zhang, Jian; Ni, Wang; Chen, Shi-Xin

    2008-03-01

    This study is to investigate the expression of CyclinD1 in asthmatic rats and construct expression plasmids of sense and antisense CyclinD1 gene and transfect them to asthmatic airway smooth muscle cell to study the effects of CyclinD1 on the proliferation of airway smooth muscle cells in asthmatic rats. CyclinD1 cDNA was obtained by RT-PCR of total RNA extracted from the airway smooth muscle in asthmatic rats. The sequence was inserted into eukaryotic expression vector pcDNA3.1 (+) to recombinate the sense and antisense pcDNA3.1-CyclinD1 eukaryotic expression vector. The two recombinations and vector were then separately transfected into airway smooth muscle cell in asthmatic rats by using liposome. The expression level of CyclinD1 was certificated by Western blotting analysis. The proliferations of ASMCs isolated from asthmatic rats were examined with cell cycle analysis, MTT colorimetric assay and proliferating cell nuclear antigen (PCNA) immunocytochemical staining. Results showed (1) Compared with control group, the content of CyclinD1 was significantly increased; (2) It was comformed by restriction endonucleasa digestion and DNA sequence analysis that the expression plasmid of sense and antisense CyclinD1 were successfully recombinated. There was significant change of CyclinD1 expression between vector and sense CyclinD1 transfected cells, and the expression level of CyclinD1 in ASMC transfected with antisense CyclinD1 was lower than that in vector transfected cells (P <0.01); (3) In the asthmatic groups, compared with the vecter group, the percentage of S + G2M phase, absorbance A value of MTT and the expression rate of PCNA protein in ASMC transfected with pcDNA3. 1-CyclinD1 vector significantly increased. The values decreased remarkably in the pcDNA3,1-as CyclinD1 group. Statistical analysis revealed that there were significant differences in these indicators of cell proliferation in three groups (P <0.01). In the normal groups, statistical analysis

  14. The use of non-viral gene vectors for bioactive poly-(D,L-lactide implant surfaces in bone tissue engineering

    Directory of Open Access Journals (Sweden)

    AK Reckhenrich

    2012-06-01

    Full Text Available The application of scaffolds in bone tissue engineering often comes along with side effects such as poor integrity, low regeneration rates of bone tissue with inadequate functionality, and, in case of non-degradable implants, the necessity of a second removal surgery after therapy. In this study, we coated a bioresorbable FDA-approved poly-(ε-caprolactone-scaffold for bone regeneration with a poly-(D,L-lactide layer containing copolymer-protected gene vectors to locally provide bone morphogenetic protein-2 (BMP-2. Results show that the presence of such gene vectors did not affect the distribution and attachment of seeded cells on gene-activated surfaces. BMP-2 was released into cell culture supernatants and furthermore detected in homogenised scaffolds. Increased amounts of osteoblastic markers, such as osteocalcin, osteopontin and the activity of alkaline phosphatase, in gene-activated scaffolds in vitro suggest a transdifferentiation of myoblastic C2C12 cells into the osteoblastic phenotype. With this study we present a new technology to bioactivate implant surfaces with non-viral gene vectors. This tool allows the stimulation of tissue regeneration by a local release of therapeutic proteins in vivo.

  15. Mal de Río Cuarto Virus Infection Triggers the Production of Distinctive Viral-Derived siRNA Profiles in Wheat and Its Planthopper Vector

    Directory of Open Access Journals (Sweden)

    Luis A. de Haro

    2017-05-01

    Full Text Available Plant reoviruses are able to multiply in gramineae plants and delphacid vectors encountering different defense strategies with unique features. This study aims to comparatively assess alterations of small RNA (sRNA populations in both hosts upon virus infection. For this purpose, we characterized the sRNA profiles of wheat and planthopper vectors infected by Mal de Río Cuarto virus (MRCV, Fijivirus, Reoviridae and quantified virus genome segments by quantitative reverse transcription PCR We provide evidence that plant and insect silencing machineries differentially recognize the viral genome, thus giving rise to distinct profiles of virus-derived small interfering RNAs (vsiRNAs. In plants, most of the virus genome segments were targeted preferentially within their upstream sequences and vsiRNAs mapped with higher density to the smaller genome segments than to the medium or larger ones. This tendency, however, was not observed in insects. In both hosts, vsiRNAs were equally derived from sense and antisense RNA strands and the differences in vsiRNAs accumulation did not correlate with mRNAs accumulation. We also established that the piwi-interacting RNA (piRNA pathway was active in the delphacid vector but, contrary to what is observed in virus-infected mosquitoes, virus-specific piRNAs were not detected. This work contributes to the understanding of the silencing response in insect and plant hosts.

  16. Delivery of recombinant alphavirus into hippocampal slice tissue culture.

    Science.gov (United States)

    Lundstrom, Kenneth

    2012-08-01

    The alphaviruses Semliki Forest virus (SFV) and Sindbis virus (SIN) have been used frequently as expression vectors in vitro and in vivo. Usually, these systems consist of replication-deficient vectors that require a helper vector for packaging of recombinant particles. Replication-proficient vectors have also been engineered. Alphaviral vectors can be used as nucleic-acid-based vectors (DNA and RNA) or infectious particles. High-titer viral production is achieved in alphaviruses facilitates studies in mammalian and nonmammalian cell lines, primary cells in culture, and in vivo. The strong preference for expression in neuronal cells has made alphaviruses particularly useful in neurobiological studies. Unfortunately, their strong cytotoxic effect on host cells, relatively short-term transient expression patterns, and the reasonably high cost of viral production remain drawbacks. However, novel mutant alphaviruses have shown reduced cytotoxicity and prolonged expression. This protocol describes gene delivery of recombinant alphavirus to hippocampal slice cultures. Organotypic slices are covered by a layer of glial cells that impedes the penetration of viral particles to the neurons. Thus, viral particles should be injected manually into the extracellular space of the tissue.

  17. Optimizing viral and non-viral gene transfer methods for genetic modification of porcine mesenchymal stem cells

    DEFF Research Database (Denmark)

    Stiehler, Maik; Duch, Mogens R.; Mygind, Tina

    2006-01-01

    -old Danish landrace pigs by Ficoll step gradient separation and polystyrene adherence technique. Vectors expressing enhanced green fluorescent protein (eGFP) and human bone morphogenetic protein-2 (BMP-2) were transferred to the cells by different non-viral methods and by use of recombinant adeno...... viral and non-viral ex vivo gene delivery systems with respect to gene transfer efficiency, maintenance of transgene expression, and safety issues using primary porcine MSCs as target cells. MATERIALS AND METHODS: MSCs were purified from bone marrow aspirates from the proximal tibiae of four 3-month...... were evaluated by realtime quantitative RT-PCR and histochemical detection of alkaline phosphatase activity, respectively. RESULTS: Non-viral gene delivery methods resulted in transient eGFP expression by less than 2% of the cells. Using high titer rAAV-based vector up to 90% of the cells were...

  18. Prokaryotic expression of recombinant nucleoprotein of viral hemorrhagic septicemia virus (VHSV)%鱼类病毒性出血性败血症病毒核蛋白基因的原核表达

    Institute of Scientific and Technical Information of China (English)

    杜娟; 兰文升; 刘荭; 郑晓聪; 陈孝煊

    2012-01-01

    通过逆转录聚合酶链式反应(RT-PCR)获得编码病毒性出血性败血症病毒(Viral hemorrhagic septicemia virus,VHSV)核蛋白基因,将其克隆至原核表达载体pET28a,并在E.coli BL21(DE3)中得到表达,用SDS-PAGE与Western-blot对表达产物进行鉴定.结果表明,通过RT-PCR扩增获得长度为1 221 bp核蛋白基因片段,诱导表达重组质粒pET28a-N,经SDS-PAGE检测,IPTG终浓度为1 mmol/L时,诱导5h蛋白表达量最高,获得的目的蛋白大小与N蛋白的预测分子质量一致,约为48 ku.诱导后的菌液进行超声波破碎后,将沉淀和上清分别用于SDS-PAGE电泳,结果表明目的蛋白主要以包涵体的形式存在.表达蛋白经过复性、纯化,得到了较高纯度的可溶性蛋白.经Western-blot检测表明,该表达产物能被羊抗VHSV阳性血清特异性识别.%Viral hemorrhagic septicemia virus (VHSV) ,the etiologic agent of viral hemorrhagic sep-ticemia in salmonid,caused great loss in aquaculture industry. Nucleoprotein is an important protein for activation of host immunological reaction. The nucleoprotein gene of VHSV was amplified by reverse transcription-polymerase chain reaction (RT-PCR) ,and cloned into pET28a vector. The recombinant E. Coli BL21 (DE3) containing pET28a-N was induced and the expressed protein was detected by SDS-PAGE and Western-blot. The nucleoprotein gene fragment was 1 221 bp in length. The 48 ku target protein was expressed successfully after induced by 1 mmol/L IPTG at 5 hours. But the protein was mainly in the form of inclusion bodies after SDS-PAGE detection. The inclusion bodies was refolded with 8 mol/L urea,and diluted in 0. 01 mol/L PBS (pH = 9. 0). Western-blot analysis showed that the expressed production can be identified specifically by the goat anti-VHSV positive serum.

  19. Development of prophylactic recombinant HPV58-attenuated Shigeila live vector vaccine and evaluation of its protective efficacy and immunogenicity in the guinea pig keratoconjunctivitis model

    Institute of Scientific and Technical Information of China (English)

    Wensheng Li; Hongli Liu; Xiaofeng Yang; Jin Zheng; Yili Wang; Lusheng Si

    2009-01-01

    To develop a prophylactic recombinant HPV58L1-attenuated Shigella live vector vaccine and evaluate its protective efficacy and immunogenicity in the guinea pig keratoconjunctivitis model, the HPV58L1 gene was cloned into vector pUCmt, and then subcloned into the suicide vector pCVD442. The recombinant plasmid pCVD442-HPV58L1 was introduced into attenuated Shigella (sf301:△virG) with the helper plasmid PRK2013 by filter mating. The positive colonies were harvested and confirmed by polymerase chain reaction. The expression of the HPV58L1 protein with a molecu-lar weight of 60 kDa was confirmed by western blot. The ability of the interested protein to self-assemble into virus-like particles was identified by transmission electron microscope, and murine erythrocyte hemagglu-tination assay. The guinea pig keratoconjunctivitis model was used to evaluate the protective efficacy and immunogenicity of the vaccine. Animal experiments showed that there was no keratoconjunctivitis occurred in the immunized group (HPV58-attenuated Shigella), and the serum levels of anti-HPV58L1-IgG and -IgA were obviously increased (P0.05). Enzyme-linked immunosorbent spot assay showed that HPV58L1-specific IgA-antibody-secreting cells (ASC) and IgG-ASC of spleen and lymph nodes were also obviously increased (P<0.01). In this study, a recombi-nant HPV58L1-attenuated Shigella live vector vaccine was successfully constructed, and it could induce strong humoral immune responses in the immunized animals, and induce protective antibody production.

  20. A high-copy T7 Escherichia coli expression vector for the production of recombinant proteins with a minimal N-terminal His-tagged fusion peptide

    Directory of Open Access Journals (Sweden)

    Ramos C.R.R.

    2004-01-01

    Full Text Available We report here the construction of a vector derived from pET3-His and pRSET plasmids for the expression and purification of recombinant proteins in Escherichia coli based on T7 phage RNA polymerase. The resulting pAE plasmid combined the advantages of both vectors: small size (pRSET, expression of a short 6XHis tag at N-terminus (pET3-His and a high copy number of plasmid (pRSET. The small size of the vector (2.8 kb and the high copy number/cell (200-250 copies facilitate the subcloning and sequencing procedures when compared to the pET system (pET3-His, 4.6 kb and 40-50 copies and also result in high level expression of recombinant proteins (20 mg purified protein/liter of culture. In addition, the vector pAE enables the expression of a fusion protein with a minimal amino-terminal hexa-histidine affinity tag (a tag of 9 amino acids using XhoI restriction enzyme for the 5'cloning site as in the case of pET3-His plasmid and in contrast to proteins expressed by pRSET plasmids (a tag of 36 amino acids using BamHI restriction enzyme for the 5'cloning site. Thus, although proteins expressed by pRSET plasmids also have a hexa-histidine tag, the fusion peptide is much longer and may represent a problem for some recombinant proteins.

  1. An induced hypersensitive-like response limits expression of foreign peptides via a recombinant TMV-based vector in a susceptible tobacco.

    Science.gov (United States)

    Li, Mangmang; Li, Ping; Song, Rentao; Xu, Zhengkai

    2010-11-29

    By using tobacco mosaic virus (TMV)-based vectors, foreign epitopes of the VP1 protein from food-and-month disease virus (FMDV) could be fused near to the C-terminus of the TMV coat protein (CP) and expressed at high levels in susceptible tobacco plants. Previously, we have shown that the recombinant TMV vaccines displaying FMDV VP1 epitopes could generate protection in guinea pigs and swine against the FMDV challenge. Recently, some recombinant TMV, such as TMVFN20 that contains an epitope FN20 from the FMDV VP1, were found to induce local necrotic lesions (LNL) on the inoculated leaves of a susceptible tobacco, Nicotiana tabacum Samsun nn. This hypersensitive-like response (HLR) blocked amplification of recombinant TMVFN20 in tobacco and limited the utility of recombinant TMV vaccines against FMDV. Here we investigate the molecular mechanism of the HLR in the susceptible Samsun nn. Histochemical staining analyses show that these LNL are similar to those induced in a resistant tobacco Samsun NN inoculated with wild type (wt) TMV. The recombinant CP subunits are specifically related to the HLR. Interestingly, this HLR in Samsun nn (lacking the N/N'-gene) was able to be induced by the recombinant TMV at both 25°C and 33°C, whereas the hypersensitive response (HR) in the resistant tobacco plants induced by wt TMV through the N/N'-gene pathways only at a permissive temperature (below 30°C). Furthermore, we reported for the first time that some of defense response (DR)-related genes in tobacco were transcriptionally upregulated during HLR. Unlike HR, HLR is induced in the susceptible tobacco through N/N'-gene independent pathways. Induction of the HLR is associated with the expression of the recombinant CP subunits and upregulation of the DR-related genes.

  2. Generation of a vector system facilitating cloning of DMBT1 variants and recombinant expression of functional full-length DMBT1

    DEFF Research Database (Denmark)

    End, Caroline; Lyer, Stefan; Renner, Marcus

    2005-01-01

    Deleted in malignant brain tumours 1 (DMBT1) codes for a approximately 340kDa glycoprotein with highly repetitive scavenger receptor cysteine-rich (SRCR) domains. DMBT1 was implicated in cancer, defence against viral and bacterial infections, and differentiation of epithelial cells. Recombinant...... yields, and protein preparations which may substantially vary due to differential processing and genetic polymorphism, all of which impedes functional research on DMBT1. Cloning of DMBT1 cDNAs is hampered because of the size and the 13 highly homologous SRCR exons. In this study, we report on the setup...

  3. Recombinant nucleocapsid-like particles from dengue-2 virus induce protective CD4+ and CD8+ cells against viral encephalitis in mice.

    Science.gov (United States)

    Gil, Lázaro; López, Carlos; Lazo, Laura; Valdés, Iris; Marcos, Ernesto; Alonso, Ruby; Gambe, Ailyn; Martín, Jorge; Romero, Yaremis; Guzmán, María G; Guillén, Gerardo; Hermida, Lisset

    2009-10-01

    Virus-like particles are a highly effective type of subunit vaccine that mimics the overall structure of virus particles without containing infectious genetic material. In this work, a particulate form of the recombinant capsid protein from dengue-2 was evaluated in mice to determine the level of protection against viral challenge and to measure the antigen-induced cell-mediated immunity (CMI). The nucleocapsid-like particles (NLPs) adjuvanted with alum did not induce antiviral antibodies. However, splenocytes from the immunized animals secreted high levels of IFN-gamma upon virus stimulation, and a significant protection rate was achieved after challenge with lethal dengue-2 virus. Finally, both IFN-gamma secretion and protection against viral encephalitis were demonstrated to be dependent on CD4(+) and CD8(+) cells. This study provides new evidences regarding the protective role of the CMI in the mouse model without the induction of neutralizing antibodies. Further studies in non-human primates or humanized mice should be carried out to elucidate the usefulness of the NLPs as a potential vaccine candidate against dengue disease.

  4. Adeno-Associated Viral Vectors Serotype 8 for Cell-Specific Delivery of Therapeutic Genes in the Central Nervous System

    Science.gov (United States)

    Pignataro, Diego; Sucunza, Diego; Vanrell, Lucia; Lopez-Franco, Esperanza; Dopeso-Reyes, Iria G.; Vales, Africa; Hommel, Mirja; Rico, Alberto J.; Lanciego, Jose L.; Gonzalez-Aseguinolaza, Gloria

    2017-01-01

    Adeno-associated viruses (AAVs) have become highly promising tools for research and clinical applications in the central nervous system (CNS). However, specific delivery of genes to the cell type of interest is essential for the success of gene therapy and therefore a correct selection of the promoter plays a very important role. Here, AAV8 vectors carrying enhanced green fluorescent protein (eGFP) as reporter gene under the transcriptional control of different CNS-specific promoters were used and compared with a strong ubiquitous promoter. Since one of the main limitations of AAV-mediated gene delivery lies in its restricted cloning capacity, we focused our work on small-sized promoters. We tested the transduction efficacy and specificity of each vector after stereotactic injection into the mouse striatum. Three glia-specific AAV vectors were generated using two truncated forms of the human promoter for glial fibrillar acidic protein (GFAP) as well as a truncated form of the murine GFAP promoter. All three vectors resulted in predominantly glial expression; however we also observed eGFP expression in other cell-types such as oligodendrocytes, but never in neurons. In addition, robust and neuron-specific eGFP expression was observed using the minimal promoters for the neural protein BM88 and the neuronal nicotinic receptor β2 (CHRNB2). In summary, we developed a set of AAV vectors designed for specific expression in cells of the CNS using minimal promoters to drive gene expression when the size of the therapeutic gene matters. PMID:28239341

  5. Tobacco mosaic virus infection results in an increase in recombination frequency and resistance to viral, bacterial, and fungal pathogens in the progeny of infected tobacco plants.

    Science.gov (United States)

    Kathiria, Palak; Sidler, Corinne; Golubov, Andrey; Kalischuk, Melanie; Kawchuk, Lawrence M; Kovalchuk, Igor

    2010-08-01

    Our previous experiments showed that infection of tobacco (Nicotiana tabacum) plants with Tobacco mosaic virus (TMV) leads to an increase in homologous recombination frequency (HRF). The progeny of infected plants also had an increased rate of rearrangements in resistance gene-like loci. Here, we report that tobacco plants infected with TMV exhibited an increase in HRF in two consecutive generations. Analysis of global genome methylation showed the hypermethylated genome in both generations of plants, whereas analysis of methylation via 5-methyl cytosine antibodies demonstrated both hypomethylation and hypermethylation. Analysis of the response of the progeny of infected plants to TMV, Pseudomonas syringae, or Phytophthora nicotianae revealed a significant delay in symptom development. Infection of these plants with TMV or P. syringae showed higher levels of induction of PATHOGENESIS-RELATED GENE1 gene expression and higher levels of callose deposition. Our experiments suggest that viral infection triggers specific changes in progeny that promote higher levels of HRF at the transgene and higher resistance to stress as compared with the progeny of unstressed plants. However, data reported in these studies do not establish evidence of a link between recombination frequency and stress resistance.

  6. Antitumor effects of murine bone marrow-derived dendritic cells infected with xenogeneic livin alpha recombinant adenoviral vectors against Lewis lung carcinoma.

    Science.gov (United States)

    Xie, Junping; Xiong, Liang; Tao, Xiaonan; Li, Xiao; Su, Yuan; Hou, Xiaohua; Shi, Huanzhong

    2010-06-01

    Transduction with recombinant, replication-defective adenoviral (rAd) vectors encoding a transgene is an efficient method for gene transfer into dendritic cells (DCs). Livin is a member of the inhibitor of apoptosis protein family. Lung cancer and many other tumors express livin at high levels; whereas, normal fully differentiated cells generally do not. Therefore, livin represents a tumor-specific target for cancer vaccine therapy. Self proteins like livin may not stimulate potent antitumor immune responses due to central immunologic tolerance. Small variations in protein sequence that may exist between homologous proteins of different species can break tolerance to the native antigen. To study immunogenicity of a xenogeneic livin protein, we constructed an recombinant adenoviral vectors containing the human livin alpha genes (rAd-hlivin alpha) and vaccinated C57BL/6 mice with mouse bone marrow dendritic cells (BMDCs) transfected with rAd-hlivin alpha gave rise to potent livin-specific cytotoxic T lymphocyte (CTL) capable of lysing Lewis lung carcinoma (LLC) cells. Moreover, vaccination of mice with rAd-hlivin alpha-transduced DCs (rAd-hlivin alpha DCs) induced a potent protective and therapeutic anti-tumor immunity to LLC in a subcutaneous model along with prolonged survival compared to mice vaccinated with control recombinant adenovirus-transduced DCs(rAd-c DCs) or DCs alone. Therefore, xenogeneic differences between human and murine sequences might be exploited to develop immunogenic tumor vaccines. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

  7. [Construction of eukaryotic recombinant vector and expression in COS7 cell of LipL32-HlyX fusion gene from Leptospira serovar Lai].

    Science.gov (United States)

    Huang, Bi; Bao, Lang; Zhong, Qi; Zhang, Huidong; Zhang, Ying

    2009-04-01

    This study was conducted to construct eukaryotic recombinant vector of LipL32-HlyX fusion gene from Leptospira serovar Lai and express it in mammalian cell. Both of LipL32 gene and HlyX gene were amplified from Leptospira strain O17 genomic DNA by PCR. Then with the two genes as template, LipL32-HlyX fusion gene was obtained by SOE PCR (gene splicing by overlap extension PCR). The fusion gene was then cloned into pcDNA3.1 by restriction nuclease digestion. Having been transformed into E. coli DH5alpha, the recombiant plasmid was identified by restriction nuclease digestion, PCR analysis and sequencing. The recombinant plasmid was then transfected into COS7 cell whose expression was detected by RT-PCR and Western blotting analysis. RT-PCR amplified a fragment about 2000 bp and Western blotting analysis found a specific band about 75 KD which was consistent with the expected fusion protein size. In conclusion, the successful construction of eukaryotic recombinant vector containing LipL32-HlyX fusion gene and the effective expression in mammalian have laid a foundation for the application of Leptospira DNA vaccine.

  8. Retroviral Vector Biosafety: Lessons from Sheep

    Directory of Open Access Journals (Sweden)

    Van den Broeke Anne

    2003-01-01

    Full Text Available The safety of retroviral-based systems and the possible transmission of replication-competent virus to patients is a major concern associated with using retroviral vectors for gene therapy. While much effort has been put into the design of safe retroviral production methods and effective in vitro monitoring assays, there is little data evaluating the risks resulting from retroviral vector instability at post-transduction stages especially following in vivo gene delivery. Here, we briefly describe and discuss our observations in an in vivo experimental model based on the inoculation of retroviral vector-transduced tumor cells in sheep. Our data indicates that the in vivo generation of mosaic viruses is a dynamic process and that virus variants, generated by retroviral vector-mediated recombination, may be stored and persist in infected individuals prior to selection at the level of replication. Recombination may not only restore essential viral functions or provide selective advantages in a changing environment but also reestablish or enhance the pathogenic potential of the particular virus undergoing recombination. These observations in sheep break new ground in our understanding of how retroviral vectors may have an impact on the course of a preestablished disease or reactivate dormant or endogenous viruses. The in vivo aspects of vector stability raise important biosafety issues for the future development of safe retroviral vector-based gene therapy.

  9. Non-viral gene delivery strategies for gene therapy: a "ménage à trois" among nucleic acids, materials, and the biological environment. Stimuli-responsive gene delivery vectors

    Science.gov (United States)

    Pezzoli, Daniele; Candiani, Gabriele

    2013-03-01

    Gene delivery is the science of transferring genetic material into cells by means of a vector to alter cellular function or structure at a molecular level. In this context, a number of nucleic acid-based drugs have been proposed and experimented so far and, as they act on distinct steps along the gene transcription-translation pathway, specific delivery strategies are required to elicit the desired outcome. Cationic lipids and polymers, collectively known as non-viral delivery systems, have thus made their breakthrough in basic and medical research. Albeit they are promising alternatives to viral vectors, their therapeutic application is still rather limited as high transfection efficiencies are normally associated to adverse cytotoxic side effects. In this scenario, drawing inspiration from processes naturally occurring in vivo, major strides forward have been made in the development of more effective materials for gene delivery applications. Specifically, smart vectors sensitive to a variety of physiological stimuli such as cell enzymes, redox status, and pH are substantially changing the landscape of gene delivery by helping to overcome some of the systemic and intracellular barriers that viral vectors naturally evade. Herein, after summarizing the state-of-the-art information regarding the use of nucleic acids as drugs, we review the main bottlenecks still limiting the overall effectiveness of non-viral gene delivery systems. Finally, we provide a critical outline of emerging stimuli-responsive strategies and discuss challenges still existing on the road toward conceiving more efficient and safer multifunctional vectors.

  10. Dynamic properties of the Sulfolobus CRISPR/Cas and CRISPR/Cmr systems when challenged with vector-borne viral and plasmid genes and protospacers

    DEFF Research Database (Denmark)

    Guðbergsdóttir, Sóley Ruth; Deng, Ling; Chen, Zhengjun

    2011-01-01

    The adaptive immune CRISPR/Cas and CRISPR/Cmr systems of the crenarchaeal thermoacidophile Sulfolobus were challenged by a variety of viral and plasmid genes, and protospacers preceded by different dinucleotide motifs. The genes and protospacers were constructed to carry sequences matching...... individual spacers of CRISPR loci, and a range of mismatches were introduced. Constructs were cloned into vectors carrying pyrE/pyrF genes and transformed into uracil auxotrophic hosts derived from Sulfolobus solfataricus P2 or Sulfolobus islandicus REY15A. Most constructs, including those carrying different...... protospacer mismatches, yielded few viable transformants. These were shown to carry either partial deletions of CRISPR loci, covering a broad spectrum of sizes and including the matching spacer, or deletions of whole CRISPR/Cas modules. The deletions occurred independently of whether genes or protospacers...

  11. Neonatal Gene Therapy for Hemophilia B by a Novel Adenovirus Vector Showing Reduced Leaky Expression of Viral Genes

    Directory of Open Access Journals (Sweden)

    Shunsuke Iizuka

    2017-09-01

    Full Text Available Gene therapy during neonatal and infant stages is a promising approach for hemophilia B, a congenital disorder caused by deficiency of blood coagulation factor IX (FIX. An adenovirus (Ad vector has high potential for use in neonatal or infant gene therapy for hemophilia B due to its superior transduction properties; however, leaky expression of Ad genes often reduces the transduction efficiencies by Ad protein-mediated tissue damage. Here, we used a novel Ad vector, Ad-E4-122aT, which exhibits a reduction in the leaky expression of Ad genes in liver, in gene therapy studies for neonatal hemophilia B mice. Ad-E4-122aT exhibited significantly higher transduction efficiencies than a conventional Ad vector in neonatal mice. In neonatal hemophilia B mice, a single neonatal injection of Ad-E4-122aT expressing human FIX (hFIX (Ad-E4-122aT-AHAFIX maintained more than 6% of the normal plasma hFIX activity levels for approximately 100 days. Sequential administration of Ad-E4-122aT-AHAFIX resulted in more than 100% of the plasma hFIX activity levels for more than 100 days and rescued the bleeding phenotypes of hemophilia B mice. In addition, immunotolerance to hFIX was induced by Ad-E4-122aT-AHAFIX administration in neonatal hemophilia B mice. These results indicated that Ad-E4-122aT is a promising gene delivery vector for neonatal or infant gene therapy for hemophilia B.

  12. Protective vaccination against infectious bursal disease virus with whole recombinant Kluyveromyces lactis yeast expressing the viral VP2 subunit.

    Directory of Open Access Journals (Sweden)

    Marina Arnold

    Full Text Available Here we report on vaccination approaches against infectious bursal disease (IBD of poultry that were performed with complete yeast of the species Kluyveromyces lactis (K. lactis. Employing a genetic system that enables the rapid production of stably transfected recombinant K. lactis, we generated yeast strains that expressed defined quantities of the virus capsid forming protein VP2 of infectious bursal disease virus (IBDV. Both, subcutaneous as well as oral vaccination regiments with the heat-inactivated but otherwise untreated yeast induced IBDV-neutralizing antibodies in mice and chickens. A full protection against a subsequent IBDV infection was achieved by subcutaneous inoculation of only milligram amounts of yeast per chicken. Oral vaccination also generated protection: while mortality was observed in control animals after virus challenge, none of the vaccinees died and ca. one-tenth were protected as indicated by the absence of lesions in the bursa of Fabricius. Recombinant K. lactis was thus indicated as a potent tool for the induction of a protective immune response by different applications. Subcutaneously applied K. lactis that expresses the IBDV VP2 was shown to function as an efficacious anti-IBD subunit vaccine.

  13. Improving Mycobacterium bovis bacillus Calmette-Guerin as a vaccine delivery vector for viral antigens by incorporation of glycolipid activators of NKT cells.

    Directory of Open Access Journals (Sweden)

    Manjunatha M Venkataswamy

    Full Text Available Recombinant Mycobacterium bovis bacillus Calmette-Guèrin (rBCG has been explored as a vector for vaccines against HIV because of its ability to induce long lasting humoral and cell mediated immune responses. To maximize the potential for rBCG vaccines to induce effective immunity against HIV, various strategies are being employed to improve its ability to prime CD8+ T cells, which play an important role in the control of HIV infections. In this study we adopted a previously described approach of incorporating glycolipids that activate CD1d-restricted natural killer T (NKT cells to enhance priming of CD8+ T cells by rBCG strains expressing an SIV Gag antigen (rBCG-SIV gag. We found that the incorporation of the synthetic NKT activating glycolipid α-galactosylceramide (α-GC into rBCG-SIV gag significantly enhanced CD8+ T cell responses against an immunodominant Gag epitope, compared to responses primed by unmodified rBCG-SIV gag. The abilities of structural analogues of α-GC to enhance CD8+ T cell responses to rBCG were compared in both wild type and partially humanized mice that express human CD1d molecules in place of mouse CD1d. These studies identified an α-GC analogue known as 7DW8-5, which has previously been used successfully as an adjuvant in non-human primates, as a promising compound for enhancing immunogenicity of antigens delivered by rBCG.vectors. Our findings support the incorporation of synthetic glycolipid activators of NKT cells as a novel approach to enhance the immunogenicity of rBCG-vectored antigens for induction of CD8+ T cell responses. The glycolipid adjuvant 7DW8-5 may be a promising candidate for advancing to non-human primate and human clinical studies for the development of HIV vaccines based on rBCG vectors.

  14. Improving Mycobacterium bovis Bacillus Calmette-Guèrin as a Vaccine Delivery Vector for Viral Antigens by Incorporation of Glycolipid Activators of NKT Cells

    Science.gov (United States)

    Kharkwal, Shalu S.; Carreño, Leandro J.; Johnson, Alison J.; Kunnath-Velayudhan, Shajo; Liu, Zheng; Bittman, Robert; Jervis, Peter J.; Cox, Liam R.; Besra, Gurdyal S.; Wen, Xiangshu; Yuan, Weiming; Tsuji, Moriya; Li, Xiangming; Ho, David D.; Chan, John; Lee, Sunhee; Frothingham, Richard; Haynes, Barton F.; Panas, Michael W.; Gillard, Geoffrey O.; Sixsmith, Jaimie D.; Korioth-Schmitz, Birgit; Schmitz, Joern E.; Larsen, Michelle H.; Jacobs, William R.; Porcelli, Steven A.

    2014-01-01

    Recombinant Mycobacterium bovis bacillus Calmette-Guèrin (rBCG) has been explored as a vector for vaccines against HIV because of its ability to induce long lasting humoral and cell mediated immune responses. To maximize the potential for rBCG vaccines to induce effective immunity against HIV, various strategies are being employed to improve its ability to prime CD8+ T cells, which play an important role in the control of HIV infections. In this study we adopted a previously described approach of incorporating glycolipids that activate CD1d-restricted natural killer T (NKT) cells to enhance priming of CD8+ T cells by rBCG strains expressing an SIV Gag antigen (rBCG-SIV gag). We found that the incorporation of the synthetic NKT activating glycolipid α-galactosylceramide (α-GC) into rBCG-SIV gag significantly enhanced CD8+ T cell responses against an immunodominant Gag epitope, compared to responses primed by unmodified rBCG-SIV gag. The abilities of structural analogues of α-GC to enhance CD8+ T cell responses to rBCG were compared in both wild type and partially humanized mice that express human CD1d molecules in place of mouse CD1d. These studies identified an α-GC analogue known as 7DW8-5, which has previously been used successfully as an adjuvant in non-human primates, as a promising compound for enhancing immunogenicity of antigens delivered by rBCG.vectors. Our findings support the incorporation of synthetic glycolipid activators of NKT cells as a novel approach to enhance the immunogenicity of rBCG-vectored antigens for induction of CD8+ T cell responses. The glycolipid adjuvant 7DW8-5 may be a promising candidate for advancing to non-human primate and human clinical studies for the development of HIV vaccines based on rBCG vectors. PMID:25255287

  15. Synthesis, and Characterization, and Evaluation of Cellular Effects of the FOL-PEG-g-PEI-GAL Nanoparticles as a Potential Non-Viral Vector for Gene Delivery

    Directory of Open Access Journals (Sweden)

    S. Ghiamkazemi

    2010-01-01

    Full Text Available In this manuscript, we synthesized the potential non viral vector for gene delivery with proper transfection efficiency and low cytotoxicity. Polyethylenimine (PEI is a well-known cationic polymer which has high positive surface charge for condensing plasmid DNA. However; it is highly cytotoxic in many cell lines because of the high surface charge, non-biodegradability and non-biocompatibility. To enhance PEI biodegradability, the graft copolymer “PEG-g-PEI” was synthesized. To target cancer liver cells, two targeting ligands folic acid and galactose (lactobionic acid which are over expressed on human hepatocyte carcinoma were attached to graft copolymer and “FOL-PEG-g-PEI-GAL” copolymer was synthesized. Composition of this grafted copolymer was characterized using 1H-NMR and FTIR spectra. The molecular weight and zeta potential of this copolymer was compared to PEI. The particle size and zeta potential of FOL-PEG-g-PEI-GAL/DNA complexes at various N/P ratio were measured using dynamic light scattering (DLS. Cytotoxicity of the copolymer was also studied in cultured HepG2 human hepatoblastoma cell line. The FOL-PEG-g-PEI-GAL/DNA complexes at various N/P ratios exhibited no cytotoxicity in HepG2 cell line compared to PEI 25K as a control. The novel copolymer showed enhanced biodegradability in physiological conditions in compared with PEI and targeted cultured HepG2 cells. More importantly, significant transfection efficiency was exhibited in cancer liver cells. Together, our results showed that “FOL-PEG-g-PEI-GAL” nanoparticals could be considered as a useful non-viral vector for targeted gene delivery.

  16. 新型人骨形成蛋白2逆转录病毒载体的构建及活性检测%Construction and identification of recombinant retroviral vector expressing BMP2 gene

    Institute of Scientific and Technical Information of China (English)

    段有文; 赤人杰; 陈晓春; 关景玉; 白宏治; 常洪涛

    2008-01-01

    目的 构建表达重组人骨形成蛋白2(BMP2)基因的重组逆转录病毒,对其在成骨细胞中的生物学作用进行探讨.方法 克隆BMP2基因,与pDNR-CMV连接构成pDNR-CMV-BMP2,然后将重组质粒pDNR-CMV-BMP2和逆转录病毒质粒pLP-LNCX以loxP位点进行同源重组,构成逆转录病毒载体pLP-LNCX-BMP2,转染包装细胞PT67进行病毒包装,NIH3T3细胞测定病毒滴度;将逆转录病毒感染人成骨细胞,噻唑蓝(MTT)法检测细胞生长变化,Western blot检测BMP2蛋白表达.结果 重组逆转录病毒载体pLP-LNCX-BMP2经鉴定连接正确;病毒载体pLP-LNCX-BMP2转染PT67后,上清液中病毒滴度可达到5×108pfu;MTT检测见逆转录病毒组与对照组比,48和72h细胞抑制率(5.1%比5.3%,8.5%比8.3%)差异无统计学意义(P>0.05),转染48 h后Westernblot可见BMP2蛋白高表达.结论 成功构建了BMP2逆转录病毒,为BMP2基因治疗及其功能研究提供了有效的手段.%Objective To construct recombinant retrovirus expressing human bone morphogenefic protein-2 gene ( BMP2 ) and investigate its biological function in osteoblasts. Methods BMP2 gene was amplified and reconstructed with pDNR-CMV into pDNR-CMV-BMP2 plasmid. Recombinant plasmid pD-NR-CMV-BMP2 and retroviral plasmid pLP-LNCX were recombinated homologously in loxP sites into pLP-LNCX-BMP2 plasmid transferred into packing cell line PT67. The viral titer was tested by NIH3T3 cells.Human osteoblasts were transfected with retrovirus. By using MTT assay, the changes in cell growth were measured. The expression of BMP2 protein was detected by Western blot. Results Recombinant retrovirus vector pLP-LNCX-BMP2 was constructed successfully. After transfection of pLP-LNCX-BMP2 into PT67,viral titer in the supernatant was up to 5 × 108 pfu. The cell growth inhibition rate at 48 and 72 h had no significant difference between retrovirus group and control group (5.1% vs 5.3% ,8.5% vs 8.3% ,P >0.05). After transfection for 48 h, the expression of

  17. Genetic diversity and drug resistance among newly diagnosed and antiretroviral treatment-naive HIV-infected individuals in western Yunnan: a hot area of viral recombination in China

    Science.gov (United States)

    2012-01-01

    Background The emergence of an HIV-1 epidemic in China was first recognized in Dehong, western Yunnan. Due to its geographic location, Dehong contributed greatly in bridging HIV-1 epidemics in Southeast Asia and China through drug trafficking and injection drug use; and also extensively to the HIV genetic diversity in Yunnan and China. We attempt to monitor HIV-1 in this area by studying the HIV-1 genetic distribution and transmitted drug resistance (TDR) in various at-risk populations. Methods Blood samples from a total of 320 newly HIV-1 diagnosed individuals, who were antiretroviral therapy (ART)-naive, were collected from January 2009 to December 2010 in 2 counties in Dehong. HIV-1 subtypes and pol gene drug resistance (DR) mutations were genotyped. Results Among 299 pol sequences successfully genotyped (93.4%), subtype C accounted for 43.1% (n=129), unique recombinant forms (URFs) for 18.4% (n=55), CRF01_AE for 17.7% (n=54), B for 10.7% (n=32), CRF08_BC for 8.4% (n=25) and CRF07_BC for 1.7% (n=5). Subtype distribution in patients infected by different transmission routes varied. In contract to the previous finding of CRF01_AE predominance in 2002-2006, subtype C predominated in both injecting drug users (IDUs) and heterosexually transmitted populations in this study. Furthermore, we found a high level of BC, CRF01_AE/C and CRF01_AE/B/C recombinants suggesting the presence of active viral recombination in the area. TDR associated mutations were identified in 4.3% (n=13) individuals. A total of 1.3% of DR were related to protease inhibitors (PIs), including I85IV, M46I and L90M; 0.3% to nucleoside reverse transcriptase inhibitors (NRTIs), including M184I; and 2.7% to non-nucleoside reverse transcriptase inhibitors (NNRTIs), including K103N/S, Y181C, K101E and G190A. Conclusion Our work revealed diverse HIV-1 subtype distributions and intersubtype recombinations. We also identified a low but significant TDR mutation rate among ART-naive patients. These findings

  18. Development of a plant viral-vector-based gene expression assay for the screening of yeast cytochrome p450 monooxygenases.

    Science.gov (United States)

    Hanley, Kathleen; Nguyen, Long V; Khan, Faizah; Pogue, Gregory P; Vojdani, Fakhrieh; Panda, Sanjay; Pinot, Franck; Oriedo, Vincent B; Rasochova, Lada; Subramanian, Mani; Miller, Barbara; White, Earl L

    2003-02-01

    Development of a gene discovery tool for heterologously expressed cytochrome P450 monooxygenases has been inherently difficult. The activity assays are labor-intensive and not amenable to parallel screening. Additionally, biochemical confirmation requires coexpression of a homologous P450 reductase or complementary heterologous activity. Plant virus gene expression systems have been utilized for a diverse group of organisms. In this study we describe a method using an RNA vector expression system to phenotypically screen for cytochrome P450-dependent fatty acid omega-hydroxylase activity. Yarrowia lipolytica CYP52 gene family members involved in n-alkane assimilation were amplified from genomic DNA, cloned into a plant virus gene expression vector, and used as a model system for determining heterologous expression. Plants infected with virus vectors expressing the yeast CYP52 genes (YlALK1-YlALK7) showed a distinct necrotic lesion phenotype on inoculated plant leaves. No phenotype was detected on negative control constructs. YlALK3-, YlALK5-, and YlALK7-inoculated plants all catalyzed the terminal hydroxylation of lauric acid as confirmed using thin-layer and gas chromatography/mass spectrometry methods. The plant-based cytochrome P450 phenotypic screen was tested on an n-alkane-induced Yarrowia lipolytica plant virus expression library. A subset of 1,025 random library clones, including YlALK1-YlALK7 constructs, were tested on plants. All YlALK gene constructs scored positive in the randomized screen. Following nucleotide sequencing of the clones that scored positive using a phenotypic screen, approximately 5% were deemed appropriate for further biochemical analysis. This report illustrates the utility of a plant-based system for expression of heterologous cytochrome P450 monooxygenases and for the assignment of gene function.

  19. Novel oligodendroglial alpha synuclein viral vector models of multiple system atrophy: studies in rodents and nonhuman primates.

    Science.gov (United States)

    Mandel, Ronald J; Marmion, David J; Kirik, Deniz; Chu, Yaping; Heindel, Clifford; McCown, Thomas; Gray, Steven J; Kordower, Jeffrey H

    2017-06-16

    Multiple system atrophy (MSA) is a horrible and unrelenting neurodegenerative disorder with an uncertain etiology and pathophysiology. MSA is a unique proteinopathy in which alpha-synuclein (α-syn) accumulates preferentially in oligodendroglia rather than neurons. Glial cytoplasmic inclusions (GCIs) of α-syn are thought to elicit changes in oligodendrocyte function, such as reduced neurotrophic support and demyelination, leading to neurodegeneration. To date, only a murine model using one of three promoters exist to study this disease. We sought to develop novel rat and nonhuman primate (NHP) models of MSA by overexpressing α-syn in oligodendroglia using a novel oligotrophic adeno-associated virus (AAV) vector, Olig001. To establish tropism, rats received intrastriatal injections of Olig001 expressing GFP. Histological analysis showed widespread expression of GFP throughout the striatum and corpus callosum with >95% of GFP+ cells co-localizing with oligodendroglia and little to no expression in neurons or astrocytes. We next tested the efficacy of this vector in rhesus macaques with intrastriatal injections of Olig001 expressing GFP. As in rats, we observed a large number of GFP+ cells in gray matter and white matter tracts of the striatum and the corpus callosum, with 90-94% of GFP+ cells co-localizing with an oligodendroglial marker. To evaluate the potential of our vector to elicit MSA-like pathology in NHPs, we injected rhesus macaques intrastriatally with Olig001 expressing the α-syn transgene. Histological analysis 3-months after injection demonstrated widespread α-syn expression throughout the striatum as determined by LB509 and phosphorylated serine-129 α-syn immunoreactivity, all of which displayed as tropism similar to that seen with GFP. As in MSA, Olig001-α-syn GCIs in our model were resistant to proteinase K digestion and caused microglial activation. Critically, demyelination was observed in the white matter tracts of the corpus callosum and

  20. Differential effects on kidney and liver growth of a non-viral hGH-expression vector in hypophysectomized mice

    DEFF Research Database (Denmark)

    Khamaisi, M.; Søndergaard, M.; Segev, Y.

    2007-01-01

    Non-viral gene transfer was investigated as a potential modality for the treatment of growth hormone deficiency (GHD) using hypophysectomized (Hx) mice as a model. Hx mice were injected with a control plasmid or a plasmid containing the human (h) GH gene driven by a ubiquitin promoter, or left......GH. Following a single hydrodynamic administration of a plasmid DNA containing the hGH gene, a sustained elevation of the circulating hGH level was observed throughout the entire observation period, with a concomitant normalization of circulating IGF-I and IGF-binding protein 3 (IGFBP-3). In addition......, longitudinal growth was corrected by normalizing tibia length, tail length, and body weight gain. Interestingly, kidney weights were only partly normalized, whereas kidney glomerular volume and liver weights were fully normalized. Kidney and liver IGF-I protein content was reduced in the Hx mice...

  1. Method for Dual Viral Vector Mediated CRISPR-Cas9 Gene Disruption in Primary Human Endothelial Cells

    Science.gov (United States)

    Gong, Haixia; Liu, Menglin; Klomp, Jeff; Merrill, Bradley J.; Rehman, Jalees; Malik, Asrar B.

    2017-01-01

    Human endothelial cells (ECs) are widely used to study mechanisms of angiogenesis, inflammation, and endothelial permeability. Targeted gene disruption induced by Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-CRISPR-Associated Protein 9 (Cas9) nuclease gene editing is potentially an important tool for definitively establishing the functional roles of individual genes in ECs. We showed that co-delivery of adenovirus encoding EGFP-tagged Cas9 and lentivirus encoding a single guide RNA (sgRNA) in primary human lung microvascular ECs (HLMVECs) disrupted the expression of the Tie2 gene and protein. Tie2 disruption increased basal endothelial permeability and prevented permeability recovery following injury induced by the inflammatory stimulus thrombin. Thus, gene deletion via viral co-delivery of CRISPR-Cas9 in primary human ECs provides a novel platform to investigate signaling mechanisms of normal and perturbed EC function without the need for clonal expansion. PMID:28198371

  2. Non-viral generation of marmoset monkey iPS cells by a six-factor-in-one-vector approach.

    Directory of Open Access Journals (Sweden)

    Katharina Debowski

    Full Text Available Groundbreaking studies showed that differentiated somatic cells of mouse and human origin could be reverted to a stable pluripotent state by the ectopic expression of only four proteins. The resulting pluripotent cells, called induced pluripotent stem (iPS cells, could be an alternative to embryonic stem cells, which are under continuous ethical debate. Hence, iPS cell-derived functional cells such as neurons may become the key for an effective treatment of currently incurable degenerative diseases. However, besides the requirement of efficacy testing of the therapy also its long-term safety needs to be carefully evaluated in settings mirroring the clinical situation in an optimal way. In this context, we chose the long-lived common marmoset monkey (Callithrix jacchus as a non-human primate species to generate iPS cells. The marmoset monkey is frequently used in biomedical research and is gaining more and more preclinical relevance due to the increasing number of disease models. Here, we describe, to our knowledge, the first-time generation of marmoset monkey iPS cells from postnatal skin fibroblasts by non-viral means. We used the transposon-based, fully reversible piggyback system. We cloned the marmoset monkey reprogramming factors and established robust and reproducible reprogramming protocols with a six-factor-in-one-construct approach. We generated six individual iPS cell lines and characterized them in comparison with marmoset monkey embryonic stem cells. The generated iPS cells are morphologically indistinguishable from marmoset ES cells. The iPS cells are fully reprogrammed as demonstrated by differentiation assays, pluripotency marker expression and transcriptome analysis. They are stable for numerous passages (more than 80 and exhibit euploidy. In summary, we have established efficient non-viral reprogramming protocols for the derivation of stable marmoset monkey iPS cells, which can be used to develop and test cell replacement

  3. Non-viral generation of marmoset monkey iPS cells by a six-factor-in-one-vector approach.

    Science.gov (United States)

    Debowski, Katharina; Warthemann, Rita; Lentes, Jana; Salinas-Riester, Gabriela; Dressel, Ralf; Langenstroth, Daniel; Gromoll, Jörg; Sasaki, Erika; Behr, Rüdiger

    2015-01-01

    Groundbreaking studies showed that differentiated somatic cells of mouse and human origin could be reverted to a stable pluripotent state by the ectopic expression of only four proteins. The resulting pluripotent cells, called induced pluripotent stem (iPS) cells, could be an alternative to embryonic stem cells, which are under continuous ethical debate. Hence, iPS cell-derived functional cells such as neurons may become the key for an effective treatment of currently incurable degenerative diseases. However, besides the requirement of efficacy testing of the therapy also its long-term safety needs to be carefully evaluated in settings mirroring the clinical situation in an optimal way. In this context, we chose the long-lived common marmoset monkey (Callithrix jacchus) as a non-human primate species to generate iPS cells. The marmoset monkey is frequently used in biomedical research and is gaining more and more preclinical relevance due to the increasing number of disease models. Here, we describe, to our knowledge, the first-time generation of marmoset monkey iPS cells from postnatal skin fibroblasts by non-viral means. We used the transposon-based, fully reversible piggyback system. We cloned the marmoset monkey reprogramming factors and established robust and reproducible reprogramming protocols with a six-factor-in-one-construct approach. We generated six individual iPS cell lines and characterized them in comparison with marmoset monkey embryonic stem cells. The generated iPS cells are morphologically indistinguishable from marmoset ES cells. The iPS cells are fully reprogrammed as demonstrated by differentiation assays, pluripotency marker expression and transcriptome analysis. They are stable for numerous passages (more than 80) and exhibit euploidy. In summary, we have established efficient non-viral reprogramming protocols for the derivation of stable marmoset monkey iPS cells, which can be used to develop and test cell replacement therapies in

  4. Oral Delivery of a Novel Recombinant Streptococcus mitis Vector Elicits Robust Vaccine Antigen-Specific Oral Mucosal and Systemic Antibody Responses and T Cell Tolerance.

    Directory of Open Access Journals (Sweden)

    Emily Xie

    Full Text Available The pioneer human oral commensal bacterium Streptococcus mitis has unique biologic features that make it an attractive mucosal vaccine or therapeutic delivery vector. S. mitis is safe as a natural persistent colonizer of the mouth, throat and nasopharynx and the oral commensal bacterium is capable of inducing mucosal antibody responses. A recombinant S. mitis (rS. mitis that stably expresses HIV envelope protein was generated and tested in the germ-free mouse model to evaluate the potential usefulness of this vector as a mucosal vaccine against HIV. Oral vaccination led to the efficient and persistent bacterial colonization of the mouth and the induction of both salivary and systemic antibody responses. Interestingly, persistently colonized animals developed antigen-specific systemic T cell tolerance. Based on these findings we propose the use of rS. mitis vaccine vector for the induction of mucosal antibodies that will prevent the penetration of the mucosa by pathogens such as HIV. Moreover, the first demonstration of rS. mitis having the ability to elicit T cell tolerance suggest the potential use of rS. mitis as an immunotherapeutic vector to treat inflammatory, allergic and autoimmune diseases.

  5. Enhancement of heterologous gene expression in Flammulina velutipes using polycistronic vectors containing a viral 2A cleavage sequence.

    Directory of Open Access Journals (Sweden)

    Yu-Ju Lin

    Full Text Available Agrobacterium tumefaciens-mediated transformation for edible mushrooms has been previously established. However, the enhancement of heterologous protein production and the expression of multi-target genes remains a challenge. In this study, heterologous protein expression in the enoki mushroom Flammulina velutipes was notably enhanced using 2A peptide-mediated cleavage to co-express multiple copies of single gene. The polycistronic expression vectors were constructed by connecting multi copies of the enhanced green fluorescent protein (egfp gene using 2A peptides derived from porcine teschovirus-1. The P2A peptides properly self-cleaved as shown by the formation of the transformants with antibiotic resistant capacity and exciting green fluorescence levels after introducing the vectors into F. velutipes mycelia. The results of western blot analysis, epifluorescent microscopy and EGFP production showed that heterologous protein expression in F. velutipes using the polycistronic strategy increased proportionally as the gene copy number increased from one to three copies. In contrast, much lower EGFP levels were detected in the F. velutipes transformants harboring four copies of the egfp gene due to mRNA instability. The polycistronic strategy using 2A peptide-mediated cleavage developed in this study can not only be used to express single gene in multiple copies, but also to express multiple genes in a single reading frame. It is a promising strategy for the application of mushroom molecular pharming.

  6. Enhancement of heterologous gene expression in Flammulina velutipes using polycistronic vectors containing a viral 2A cleavage sequence.

    Science.gov (United States)

    Lin, Yu-Ju; Huang, Li-Hsin; Huang, Ching-Tsan

    2013-01-01

    Agrobacterium tumefaciens-mediated transformation for edible mushrooms has been previously established. However, the enhancement of heterologous protein production and the expression of multi-target genes remains a challenge. In this study, heterologous protein expression in the enoki mushroom Flammulina velutipes was notably enhanced using 2A peptide-mediated cleavage to co-express multiple copies of single gene. The polycistronic expression vectors were constructed by connecting multi copies of the enhanced green fluorescent protein (egfp) gene using 2A peptides derived from porcine teschovirus-1. The P2A peptides properly self-cleaved as shown by the formation of the transformants with antibiotic resistant capacity and exciting green fluorescence levels after introducing the vectors into F. velutipes mycelia. The results of western blot analysis, epifluorescent microscopy and EGFP production showed that heterologous protein expression in F. velutipes using the polycistronic strategy increased proportionally as the gene copy number increased from one to three copies. In contrast, much lower EGFP levels were detected in the F. velutipes transformants harboring four copies of the egfp gene due to mRNA instability. The polycistronic strategy using 2A peptide-mediated cleavage developed in this study can not only be used to express single gene in multiple copies, but also to express multiple genes in a single reading frame. It is a promising strategy for the application of mushroom molecular pharming.

  7. International network for capacity building for the control of emerging viral vector-borne zoonotic diseases: ARBO-ZOONET.

    Science.gov (United States)

    Ahmed, J; Bouloy, M; Ergonul, O; Fooks, Ar; Paweska, J; Chevalier, V; Drosten, C; Moormann, R; Tordo, N; Vatansever, Z; Calistri, P; Estrada-Pena, A; Mirazimi, A; Unger, H; Yin, H; Seitzer, U

    2009-03-26

    Arboviruses are arthropod-borne viruses, which include West Nile fever virus (WNFV), a mosquito-borne virus, Rift Valley fever virus (RVFV), a mosquito-borne virus, and Crimean-Congo haemorrhagic fever virus (CCHFV), a tick-borne virus. These arthropod-borne viruses can cause disease in different domestic and wild animals and in humans, posing a threat to public health because of their epidemic and zoonotic potential. In recent decades, the geographical distribution of these diseases has expanded. Outbreaks of WNF have already occurred in Europe, especially in the Mediterranean basin. Moreover, CCHF is endemic in many European countries and serious outbreaks have occurred, particularly in the Balkans, Turkey and Southern Federal Districts of Russia. In 2000, RVF was reported for the first time outside the African continent, with cases being confirmed in Saudi Arabia and Yemen. This spread was probably caused by ruminant trade and highlights that there is a threat of expansion of the virus into other parts of Asia and Europe. In the light of global warming and globalisation of trade and travel, public interest in emerging zoonotic diseases has increased. This is especially evident regarding the geographical spread of vector-borne diseases. A multi-disciplinary approach is now imperative, and groups need to collaborate in an integrated manner that includes vector control, vaccination programmes, improved therapy strategies, diagnostic tools and surveillance, public awareness, capacity building and improvement of infrastructure in endemic regions.

  8. Dry-Coated Live Viral Vector Vaccines Delivered by Nanopatch Microprojections Retain Long-Term Thermostability and Induce Transgene-Specific T Cell Responses in Mice

    Science.gov (United States)

    Pearson, Frances E.; McNeilly, Celia L.; Crichton, Michael L.; Primiero, Clare A.; Yukiko, Sally R.; Fernando, Germain J. P.; Chen, Xianfeng; Gilbert, Sarah C.; Hill, Adrian V. S.; Kendall, Mark A. F.

    2013-01-01

    The disadvantages of needle-based immunisation motivate the development of simple, low cost, needle-free alternatives. Vaccine delivery to cutaneous environments rich in specialised antigen-presenting cells using microprojection patches has practical and immunological advantages over conventional needle delivery. Additionally, stable coating of vaccine onto microprojections removes logistical obstacles presented by the strict requirement for cold-chain storage and distribution of liquid vaccine, or lyophilised vaccine plus diluent. These attributes make these technologies particularly suitable for delivery of vaccines against diseases such as malaria, which exerts its worst effects in countries with poorly-resourced healthcare systems. Live viral vectors including adenoviruses and poxviruses encoding exogenous antigens have shown significant clinical promise as vaccines, due to their ability to generate high numbers of antigen-specific T cells. Here, the simian adenovirus serotype 63 and the poxvirus modified vaccinia Ankara – two vectors under evaluation for the delivery of malaria antigens to humans – were formulated for coating onto Nanopatch microprojections and applied to murine skin. Co-formulation with the stabilising disaccharides trehalose and sucrose protected virions during the dry-coating process. Transgene-specific CD8+ T cell responses following Nanopatch delivery of both vectors were similar to intradermal injection controls after a single immunisation (despite a much lower delivered dose), though MVA boosting of pre-primed responses with Nanopatch was found to be less effective than the ID route. Importantly, disaccharide-stabilised ChAd63 could be stored for 10 weeks at 37°C with less than 1 log10 loss of viability, and retained single-dose immunogenicity after storage. These data support the further development of microprojection patches for the deployment of live vaccines in hot climates. PMID:23874462

  9. Dry-coated live viral vector vaccines delivered by nanopatch microprojections retain long-term thermostability and induce transgene-specific T cell responses in mice.

    Directory of Open Access Journals (Sweden)

    Frances E Pearson

    Full Text Available The disadvantages of needle-based immunisation motivate the development of simple, low cost, needle-free alternatives. Vaccine delivery to cutaneous environments rich in specialised antigen-presenting cells using microprojection patches has practical and immunological advantages over conventional needle delivery. Additionally, stable coating of vaccine onto microprojections removes logistical obstacles presented by the strict requirement for cold-chain storage and distribution of liquid vaccine, or lyophilised vaccine plus diluent. These attributes make these technologies particularly suitable for delivery of vaccines against diseases such as malaria, which exerts its worst effects in countries with poorly-resourced healthcare systems. Live viral vectors including adenoviruses and poxviruses encoding exogenous antigens have shown significant clinical promise as vaccines, due to their ability to generate high numbers of antigen-specific T cells. Here, the simian adenovirus serotype 63 and the poxvirus modified vaccinia Ankara--two vectors under evaluation for the delivery of malaria antigens to humans--were formulated for coating onto Nanopatch microprojections and applied to murine skin. Co-formulation with the stabilising disaccharides trehalose and sucrose protected virions during the dry-coating process. Transgene-specific CD8(+ T cell responses following Nanopatch delivery of both vectors were similar to intradermal injection controls after a single immunisation (despite a much lower delivered dose, though MVA boosting of pre-primed responses with Nanopatch was found to be less effective than the ID route. Importantly, disaccharide-stabilised ChAd63 could be stored for 10 weeks at 37°C with less than 1 log10 loss of viability, and retained single-dose immunogenicity after storage. These data support the further development of microprojection patches for the deployment of live vaccines in hot climates.

  10. Dry-coated live viral vector vaccines delivered by nanopatch microprojections retain long-term thermostability and induce transgene-specific T cell responses in mice.

    Science.gov (United States)

    Pearson, Frances E; McNeilly, Celia L; Crichton, Michael L; Primiero, Clare A; Yukiko, Sally R; Fernando, Germain J P; Chen, Xianfeng; Gilbert, Sarah C; Hill, Adrian V S; Kendall, Mark A F

    2013-01-01

    The disadvantages of needle-based immunisation motivate the development of simple, low cost, needle-free alternatives. Vaccine delivery to cutaneous environments rich in specialised antigen-presenting cells using microprojection patches has practical and immunological advantages over conventional needle delivery. Additionally, stable coating of vaccine onto microprojections removes logistical obstacles presented by the strict requirement for cold-chain storage and distribution of liquid vaccine, or lyophilised vaccine plus diluent. These attributes make these technologies particularly suitable for delivery of vaccines against diseases such as malaria, which exerts its worst effects in countries with poorly-resourced healthcare systems. Live viral vectors including adenoviruses and poxviruses encoding exogenous antigens have shown significant clinical promise as vaccines, due to their ability to generate high numbers of antigen-specific T cells. Here, the simian adenovirus serotype 63 and the poxvirus modified vaccinia Ankara--two vectors under evaluation for the delivery of malaria antigens to humans--were formulated for coating onto Nanopatch microprojections and applied to murine skin. Co-formulation with the stabilising disaccharides trehalose and sucrose protected virions during the dry-coating process. Transgene-specific CD8(+) T cell responses following Nanopatch delivery of both vectors were similar to intradermal injection controls after a single immunisation (despite a much lower delivered dose), though MVA boosting of pre-primed responses with Nanopatch was found to be less effective than the ID route. Importantly, disaccharide-stabilised ChAd63 could be stored for 10 weeks at 37°C with less than 1 log10 loss of viability, and retained single-dose immunogenicity after storage. These data support the further development of microprojection patches for the deployment of live vaccines in hot climates.

  11. A set of vectors for introduction of antibiotic resistance genes by in vitro Cre-mediated recombination

    OpenAIRE

    Vassetzky Yegor S; Dmitriev Petr V

    2008-01-01

    Abstract Background Introduction of new antibiotic resistance genes in the plasmids of interest is a frequent task in molecular cloning practice. Classical approaches involving digestion with restriction endonucleases and ligation are time-consuming. Findings We have created a set of insertion vectors (pINS) carrying genes that provide resistance to various antibiotics (puromycin, blasticidin and G418) and containing a loxP site. Each vector (pINS-Puro, pINS-Blast or pINS-Neo) contains either...

  12. In vivo administration of recombinant alphavirus into rodents.

    Science.gov (United States)

    Lundstrom, Kenneth

    2012-08-01

    The alphaviruses Semliki Forest virus (SFV) and Sindbis virus (SIN) have been used frequently as expression vectors in vitro and in vivo. Usually, these systems consist of replication-deficient vectors that require a helper vector for packaging of recombinant particles. Replication-proficient vectors have also been engineered. Alphaviral vectors can be used as nucleic-acid-based vectors (DNA and RNA) or infectious particles. High-titer viral production is achieved in alphaviruses facilitates studies in mammalian and nonmammalian cell lines, primary cells in culture, and in vivo. The strong preference for expression in neuronal cells has made alphaviruses particularly useful in neurobiological studies. Unfortunately, their strong cytotoxic effect on host cells, relatively short-term transient expression patterns, and the reasonably high cost of viral production remain drawbacks. However, novel mutant alphaviruses have shown reduced cytotoxicity and prolonged expression. This protocol describes stereotactic microinjection of recombinant alphavirus into rodents. Administration can be performed without any purification or concentration of viral stocks. However, filter-sterilization is recommended to ensure that cell debris or other contaminants are not present.

  13. Priming T-cell responses with recombinant measles vaccine vector in a heterologous prime-boost setting in non-human primates.

    Science.gov (United States)

    Bolton, Diane L; Santra, Sampa; Swett-Tapia, Cindy; Custers, Jerome; Song, Kaimei; Balachandran, Harikrishnan; Mach, Linh; Naim, Hussein; Kozlowski, Pamela A; Lifton, Michelle; Goudsmit, Jaap; Letvin, Norman; Roederer, Mario; Radošević, Katarina

    2012-09-07

    Licensed live attenuated virus vaccines capable of expressing transgenes from other pathogens have the potential to reduce the number of childhood immunizations by eliciting robust immunity to multiple pathogens simultaneously. Recombinant attenuated measles virus (rMV) derived from the Edmonston Zagreb vaccine strain was engineered to express simian immunodeficiency virus (SIV) Gag protein for the purpose of evaluating the immunogenicity of rMV as a vaccine vector in rhesus macaques. rMV-Gag immunization alone elicited robust measles-specific humoral and cellular responses, but failed to elicit transgene (Gag)-specific immune responses, following aerosol or intratracheal/intramuscular delivery. However, when administered as a priming vaccine to a heterologous boost with recombinant adenovirus serotype 5 expressing the same transgene, rMV-Gag significantly enhanced Gag-specific T lymphocyte responses following rAd5 immunization. Gag-specific humoral responses were not enhanced, however, which may be due to either the transgene or the vector. Cellular response priming by rMV against the transgene was highly effective even when using a suboptimal dose of rAd5 for the boost. These data demonstrate feasibility of using rMV as a priming component of heterologous prime-boost vaccine regimens for pathogens requiring strong cellular responses.

  14. Recombinant protein expression in Nicotiana.

    Science.gov (United States)

    Matoba, Nobuyuki; Davis, Keith R; Palmer, Kenneth E

    2011-01-01

    Recombinant protein pharmaceuticals are now widely used in treatment of chronic diseases, and several recombinant protein subunit vaccines are approved for human and veterinary use. With growing demand for complex protein pharmaceuticals, such as monoclonal antibodies, manufacturing capacity is becoming limited. There is increasing need for safe, scalable, and economical alternatives to mammalian cell culture-based manufacturing systems, which require substantial capital investment for new manufacturing facilities. Since a seminal paper reporting immunoglobulin expression in transgenic plants was published in 1989, there have been many technological advances in plant expression systems to the present time where production of proteins in leaf tissues of nonfood crops such as Nicotiana species is considered a viable alternative. In particular, transient expression systems derived from recombinant plant viral vectors offer opportunities for rapid expression screening, construct optimization, and expression scale-up. Extraction of recombinant proteins from Nicotiana leaf tissues can be achieved by collection of secreted protein fractions, or from a total protein extract after grinding the leaves with buffer. After separation from solids, the major purification challenge is contamination with elements of the photosynthetic complex, which can be solved by application of a variety of facile and proven strategies. In conclusion, the technologies required for safe, efficient, scalable manufacture of recombinant proteins in Nicotiana leaf tissues have matured to the point where several products have already been tested in phase I clinical trials and will soon be followed by a rich pipeline of recombinant vaccines, microbicides, and therapeutic proteins.

  15. Efficacy of vaccination with recombinant vaccinia and fowlpox vectors expressing NY-ESO-1 antigen in ovarian cancer and melanoma patients.

    Science.gov (United States)

    Odunsi, Kunle; Matsuzaki, Junko; Karbach, Julia; Neumann, Antje; Mhawech-Fauceglia, Paulette; Miller, Austin; Beck, Amy; Morrison, Carl D; Ritter, Gerd; Godoy, Heidi; Lele, Shashikant; duPont, Nefertiti; Edwards, Robert; Shrikant, Protul; Old, Lloyd J; Gnjatic, Sacha; Jäger, Elke

    2012-04-10

    Recombinant poxviruses (vaccinia and fowlpox) expressing tumor-associated antigens are currently being evaluated in clinical trials as cancer vaccines to induce tumor-specific immune responses that will improve clinical outcome. To test whether a diversified prime and boost regimen targeting NY-ESO-1 will result in clinical benefit, we conducted two parallel phase II clinical trials of recombinant vaccinia-NY-ESO-1 (rV-NY-ESO-1), followed by booster vaccinations with recombinant fowlpox-NY-ESO-1 (rF-NY-ESO-1) in 25 melanoma and 22 epithelial ovarian cancer (EOC) patients with advanced disease who were at high risk for recurrence/progression. Integrated NY-ESO-1-specific antibody and CD4(+) and CD8(+) T cells were induced in a high proportion of melanoma and EOC patients. In melanoma patients, objective response rate [complete and partial response (CR+PR)] was 14%, mixed response was 5%, and disease stabilization was 52%, amounting to a clinical benefit rate (CBR) of 72% in melanoma patients. The median PFS in the melanoma patients was 9 mo (range, 0-84 mo) and the median OS was 48 mo (range, 3-106 mo). In EOC patients, the median PFS was 21 mo (95% CI, 16-29 mo), and median OS was 48 mo (CI, not estimable). CD8(+) T cells derived from vaccinated patients were shown to lyse NY-ESO-1-expressing tumor targets. These data provide preliminary evidence of clinically meaningful benefit for diversified prime and boost recombinant pox-viral-based vaccines in melanoma and ovarian cancer and support further evaluation of this approach in these patient populations.

  16. Protective efficacy of a single immunization with capripoxvirus-vectored recombinant peste des petits ruminants vaccines in presence of pre-existing immunity.

    Science.gov (United States)

    Caufour, Philippe; Rufael, Tesfaye; Lamien, Charles Euloge; Lancelot, Renaud; Kidane, Menbere; Awel, Dino; Sertse, Tefera; Kwiatek, Olivier; Libeau, Geneviève; Sahle, Mesfin; Diallo, Adama; Albina, Emmanuel

    2014-06-24

    Sheeppox, goatpox and peste des petits ruminants (PPR) are highly contagious ruminant diseases widely distributed in Africa, the Middle East and Asia. Capripoxvirus (CPV)-vectored recombinant PPR vaccines (rCPV-PPR vaccines), which have been developed and shown to protect against both Capripox (CP) and PPR, would be critical tools in the control of these important diseases. In most parts of the world, these disease distributions overlap each other leaving concerns about the potential impact that pre-existing immunity against either disease may have on the protective efficacy of these bivalent rCPV-PPR vaccines. Currently, this question has not been indisputably addressed. Therefore, we undertook this study, under experimental conditions designed for the context of mass vaccination campaigns of small ruminants, using the two CPV recombinants (Kenya sheep-1 (KS-1) strain-based constructs) developed previously in our laboratory. Pre-existing immunity was first induced by immunization either with an attenuated CPV vaccine strain (KS-1) or the attenuated PPRV vaccine strain (Nigeria 75/1) and animals were thereafter inoculated once subcutaneously with a mixture of CPV recombinants expressing either the hemagglutinin (H) or the fusion (F) protein gene of PPRV (10(3) TCID50/animal of each). Finally, these animals were challenged with a virulent CPV strain followed by a virulent PPRV strain 3 weeks later. Our study demonstrated full protection against CP for vaccinated animals with prior exposure to PPRV and a partial protection against PPR for vaccinated animals with prior exposure to CPV. The latter animals exhibited a mild clinical form of PPR and did not show any post-challenge anamnestic neutralizing antibody response against PPRV. The implications of these results are discussed herein and suggestions made for future research regarding the development of CPV-vectored vaccines. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Recombinant Vaccinia Virus is an Effective and Non-perturbing Vector for Human Dendritic Cells Transfected with Epstein-Barr Virus Latent Membrane Protein 2A

    Institute of Scientific and Technical Information of China (English)

    许继军; 姚堃; 彭光勇; 谢芳艺; 丁传林; 朱建中; 秦健

    2002-01-01

    ObjectiveTo study the effects of dendritic cells (DC) transfected with recombinant vaccinia virus encoding Epstein-Barr virus (EBV) latent membrane protein 2A(LMP2A) gene,and to provide evidence for further investigation on the therapeutic vaccines against EBV-associated malignancies.MethodsMature DC were transfected with EBV-LMP2A recombinant vaccinia virus (rVV-LMP2A).Before and after the transfection,the expression of surface antigens on mature DC including CD1a,CD83,CD40,CD80,HLA-DR was measured by fluorescence activated cell sorter (FACS) and the function of DC to stimulate allogeneic T cells proliferation was measured by mixed leukocyte reactions (MLR).ResultsLMP2A protein was highly expressed (66.1%) in DC after the transfection of rVV-LMP2A.No significant changes in the primary surface antigens expression and in the MLR were detected during the transfection.Transfected DC still had strong potential in stimulating the proliferation of allogeneic T cells.ConclusionRecombinant vaccinia virus was an effective and non-perturbing vector to mediate the transfection of LMP2A into DC.The functions of mature DC were not affected significantly by the transfection of Vac-LMP2A.This study could provide evidence for the further immunotherapy of EBV-associated malignancies,e.g.nasopharyngeal carcinoma (NPC).``

  18. Recombinant Vaccinia Virus is an Effective and Non—perturbing Vector for Human Dendritic Cells Transfected with Epstein—Barr Virus Latent Membrane Protein 2A

    Institute of Scientific and Technical Information of China (English)

    许继军; 姚Kun; 等

    2002-01-01

    Objective To study the effects of dendritic cells(DC) transfected with recombinant vaccinia virus encoding Epstein-Barr virus(EBV) latent membrane protein 2A(LMP2A) gene,and to provide evidence for further investigation on the therapeutic uaccines against EBV-associated malignancies.Methods Mature DC were transfected with EVB-LMP2A recombinant vaccinia virus(rVV-LMP2A).Before and after the transfection,the expression of surface antigens on mature DC including CD1a,CD83,CD40,CD80,HLA-DR was measured by fluorescence activated cell sorter(FACS) and the function of DC to stimulate allogeneic T cells proliferation was measured by mixed leukocyte reactions(MLR).Results LMP2A protein was highly expressed (66.1%) in DC after the transfection of rVV-LMP2A.No significant changes in the primary surface antigens expression and in the MLR were detected during the transfection.Transfected DC still had strong potential in stimulating the proliferation of allogeneic T cells.Conclusion Recombinant vaccinia virus was an effective and non-perturbing vector to mediate the transfection of LMP2A into DC.The functions of mature DC were not affected significantly by the transfection of Vac-LMP2A.This study could provide evidence for the further immunotherapy of EBV-associated malignancies,e.g.nasopharyngeal carcinoma(NPC).

  19. Recombinant expression of placental growth factor in baculovirus expression system

    Directory of Open Access Journals (Sweden)

    Narges Arbabi

    2016-12-01

    Full Text Available Background: Angiogenesis or formation of new blood vessels is the most important factor in physiological and pathological conditions. Human Placental growth factor (hPLGF protein in is one of the most important proteins which stimulate angiogenesis. Baculovirus expression system has been used successfully to over express eukaryotic proteins in insect cells. This system uses a very strong viral promoter, AcNPV polyhedrin, for high level of protein expression. Methods: hPLGF gene cloned in pFastBac-HT vector and transformed in DH10Bac.The recombinant bacmid was extracted and used in SF9 insect cells and transfected by cellfectin method. Target protein expression was confirmed with Western blot. Results: Transferring of the recombinant vector into Bacmid was successful and the PLGF gene sequence was confirmed. PLGF and recombinant protein expression by Western blotting was confirmed. Conclusion: Baculovirus protein expression system expresses PLGF strongly and recombinant protein can be used in different tests.

  20. Selective optical control of synaptic transmission in the subcortical visual pathway by activation of viral vector-expressed halorhodopsin.

    Directory of Open Access Journals (Sweden)

    Katsuyuki Kaneda

    Full Text Available The superficial layer of the superior colliculus (sSC receives visual inputs via two different pathways: from the retina and the primary visual cortex. However, the functional significance of each input for the operation of the sSC circuit remains to be identified. As a first step toward understanding the functional role of each of these inputs, we developed an optogenetic method to specifically suppress the synaptic transmission in the retino-tectal pathway. We introduced enhanced halorhodopsin (eNpHR, a yellow light-sensitive, membrane-targeting chloride pump, into mouse retinal ganglion cells (RGCs by intravitreously injecting an adeno-associated virus serotype-2 vector carrying the CMV-eNpHR-EYFP construct. Several weeks after the injection, whole-cell recordings made from sSC neurons in slice preparations revealed that yellow laser illumination of the eNpHR-expressing retino-tectal axons, putatively synapsing onto the recorded cells, effectively inhibited EPSCs evoked by electrical stimulation of the optic nerve layer. We also showed that sSC spike activities elicited by visual stimulation were significantly reduced by laser illumination of the sSC in anesthetized mice. These results indicate that photo-activation of eNpHR expressed in RGC axons enables selective blockade of retino-tectal synaptic transmission. The method established here can most likely be applied to a variety of brain regions for studying the function of individual inputs to these regions.

  1. Targeted CNS delivery using human MiniPromoters and demonstrated compatibility with adeno-associated viral vectors

    Directory of Open Access Journals (Sweden)

    Charles N de Leeuw

    2014-01-01

    Full Text Available Critical for human gene therapy is the availability of small promoters tools to drive gene expression in a highly specific and reproducible manner. We tackled this challenge by developing human DNA MiniPromoters (MiniPs using computational biology and phylogenetic conservation. MiniPs were tested in mouse as single-copy knock-ins at the Hprt locus on the X chromosome and evaluated for lacZ reporter expression in central nervous system (CNS and non–CNS tissue. Eighteen novel MiniPs driving expression in mouse brain were identified, 2 MiniPs for driving pan-neuronal expression and 17 MiniPs for the mouse eye. Key areas of therapeutic interest were represented in this set: the cerebral cortex, embryonic hypothalamus, spinal cord, bipolar and ganglion cells of the retina, and skeletal muscle. We also demonstrated that three retinal ganglion cell MiniPs exhibit similar cell type specificity when delivered via adeno-associated virus vectors intravitreally. We conclude that our methodology and characterization has resulted in desirable expression characteristics that are intrinsic to the MiniPromoter, not dictated by copy-number effects or genomic location, and results in constructs predisposed to success in adeno-associated virus. These MiniPs are immediately applicable for preclinical studies toward gene therapy in humans and are publicly available to facilitate basic and clinical research, and human gene therapy.

  2. Targeted CNS delivery using human MiniPromoters and demonstrated compatibility with adeno-associated viral vectors

    Science.gov (United States)

    de Leeuw, Charles N; Dyka, Frank M; Boye, Sanford L; Laprise, Stéphanie; Zhou, Michelle; Chou, Alice Y; Borretta, Lisa; McInerny, Simone C; Banks, Kathleen G; Portales-Casamar, Elodie; Swanson, Magdalena I; D’Souza, Cletus A; Boye, Shannon E; Jones, Steven JM; Holt, Robert A; Goldowitz, Daniel; Hauswirth, William W; Wasserman, Wyeth W; Simpson, Elizabeth M

    2014-01-01

    Critical for human gene therapy is the availability of small promoters tools to drive gene expression in a highly specific and reproducible manner. We tackled this challenge by developing human DNA MiniPromoters (MiniPs) using computational biology and phylogenetic conservation. MiniPs were tested in mouse as single-copy knock-ins at the Hprt locus on the X chromosome and evaluated for lacZ reporter expression in central nervous system (CNS) and non–CNS tissue. Eighteen novel MiniPs driving expression in mouse brain were identified, 2 MiniPs for driving pan-neuronal expression and 17 MiniPs for the mouse eye. Key areas of therapeutic interest were represented in this set: the cerebral cortex, embryonic hypothalamus, spinal cord, bipolar and ganglion cells of the retina, and skeletal muscle. We also demonstrated that three retinal ganglion cell MiniPs exhibit similar cell type specificity when delivered via adeno-associated virus vectors intravitreally. We conclude that our methodology and characterization has resulted in desirable expression characteristics that are intrinsic to the MiniPromoter, not dictated by copy-number effects or genomic location, and results in constructs predisposed to success in adeno-associated virus. These MiniPs are immediately applicable for preclinical studies toward gene therapy in humans and are publicly available to facilitate basic and clinical research, and human gene therapy. PMID:24761428

  3. Joint capsule treatment with enkephalin-encoding HSV-1 recombinant vector reduces inflammatory damage and behavioural sequelae in rat CFA monoarthritis.

    Science.gov (United States)

    Lu, Ying; McNearney, Terry A; Wilson, Steven P; Yeomans, David C; Westlund, Karin N

    2008-03-01

    This study assessed enkephalin expression induced by intra-articular application of recombinant, enkephalin-encoding herpes virus (HSV-1) and the impact of expression on nociceptive behaviours and synovial lining inflammation in arthritic rats. Replication-conditional HSV-1 recombinant vectors with cDNA encoding preproenkephalin (HSV-ENK), or control transgene beta-galactosidase cDNA (HSV-beta-gal; control) were injected into knee joints with complete Freund's adjuvant (CFA). Joint temperatures, circumferences and nociceptive behaviours were monitored on days 0, 7, 14 and 21 post CFA and vector treatments. Lumbar (L4-6) dorsal root ganglia (DRG) and spinal cords were immunostained for met-enkephalin (met-ENK), beta-gal, HSV-1 proteins and Fos. Joint tissues were immunostained for met-ENK, HSV-1 proteins, and inflammatory mediators Regulated on Activation, Normal T-cell Expressed and Secreted (RANTES) and cyclo-oxygenase-2, or stained with haematoxylin and eosin for histopathology. Compared to exuberant synovial hypertrophy and inflammatory cell infiltration seen in arthritic rats treated with CFA only or CFA and HSV-beta-gal, the CFA- and HSV-ENK-treated arthritic rats had: (i) striking preservation of synovial membrane cytoarchitecture with minimal inflammatory cell infiltrates; (ii) significantly improved nociceptive behavioural responses to mechanical and thermal stimuli; (iii) normalized Fos staining in lumbar dorsal horn; and (iv) significantly increased met-ENK staining in ipsilateral synovial tissue, lumbar DRG and spinal cord. The HSV-1 and transgene product expression were confined to ipsilateral lumbar DRG (HSV-1, met-ENK, beta-gal). Only transgene product (met-ENK and beta-gal) was seen in lumbar spinal cord sections. Targeted delivery of enkephalin-encoding HSV-1 vector generated safe, sustained opioid-induced analgesia with protective anti-inflammatory blunting in rat inflammatory arthritis.

  4. Novel recombinant binary vectors harbouring Basta (bar) gene as a plant selectable marker for genetic transformation of plants.

    Science.gov (United States)

    Nada, Reham M

    2016-04-01

    Genetic transformation is one of the most widely used technique in crop improvement. However, most of the binary vectors used in this technique, especially cloning based, contain antibiotic genes as selection marker that raise serious consumer and environmental concerns; moreover, they could be transferred to non-target hosts with deleterious effects. Therefore, the goal of this study was reconstruction of the widely used pBI121 binary vector by substituting the harmful antibiotic selection marker gene with a less-harmful selection marker, Basta (herbicide resistance gene). The generated vectors were designated as pBI121NB and pBI121CB, in which Basta gene was expressed under the control of Nos or CaMV 35S promoter, respectively. The successful integration of the new inserts into both the vectors was confirmed by PCR, restriction digestion and sequencing. Both these vectors were used in transforming Arabidopsis, Egyptian wheat and barley varieties using LBA4404 and GV3101 Agrobacterium strains. The surfactant Tween-20 resulted in an efficient transformation and the number of Arabidopsis transformants was about 6-9 %. Soaked seeds of wheat and barley were transformed with Agrobacterium to introduce the bacteria to the growing shoot apices. The percentage of transgenic lines was around 16-17 and 14-15 % for wheat and barley, respectively. The quantitative studies presented in this work showed that both LBA4404 and GV3101 strains were suitable for transforming Egyptian wheat and barley.

  5. Analysis of particle content of recombinant adeno-associated virus serotype 8 vectors by ion-exchange chromatography.

    Science.gov (United States)

    Lock, Martin; Alvira, Mauricio R; Wilson, James M

    2012-02-01

    Advances in adeno-associated virus (AAV)-mediated gene therapy have brought the possibility of commercial manufacturing of AAV vectors one step closer. To realize this prospect, a parallel effort with the goal of ever-increasing sophistication for AAV vector production technology and supporting assays will be required. Among the important release assays for a clinical gene therapy product, those monitoring potentially hazardous contaminants are most critical for patient safety. A prominent contaminant in many AAV vector preparations is vector particles lacking a genome, which can substantially increase the dose of AAV capsid proteins and lead to possible unwanted immunological consequences. Current methods to determine empty particle content suffer from inconsistency, are adversely affected by contaminants, or are not applicable to all serotypes. Here we describe the development of an ion-exchange chromatography-based assay that permits the rapid separation and relative quantification of AAV8 empty and full vector particles through the application of shallow gradients and a strong anion-exchange monolith chromatography medium.

  6. A Comparison of Target Gene Silencing using Synthetically Modified siRNA and shRNA That Express Recombinant Lentiviral Vectors.

    Science.gov (United States)

    Spirin, P V; Baskaran, D; Rubtsov, P M; Zenkova, M A; Vlassov, V V; Chernolovskaya, E L; Prassolov, V S

    2009-07-01

    RNA-interference is an effective natural mechanism of post-transcriptional modulation of gene expression. RNA-interference mechanism exist as in high eukaryotes both animals and plants as well in lower eukaryotes and viruses. RNA-interference is now used as a powerful tool in study of functional gene activity and many essential for fundamental biology results was obtained with this approach. Also it's widely believed that RNA-interference could be used in working out of new therapeutic medicine against malignant, infectious and hereditary diseases. One of the main problems of these developments is search of effective methods of siRNA transfer into the target cells. At present time for these purpose different sorts of transfect ions or viral transduction are used. At present article the results of comparison of inhibition of expression of oncogene AML-ET O by synthetic siRNA and by recombinant lentiviruses coding for corresponding shRNA are presented.

  7. Viral vector mediated continuous expression of interleukin-10 in DRG alleviates pain in type 1 diabetic animals.

    Science.gov (United States)

    Thakur, Vikram; Gonzalez, Mayra; Pennington, Kristen; Chattopadhyay, Munmun

    2016-04-01

    Painful diabetic neuropathy is a common and difficult to treat complication of diabetes. A growing body of evidence implicates the role of inflammatory mediators in the damage to the peripheral axons and in the pathogenesis of neuropathic pain. Increased expression of pro-inflammatory cytokines such as interleukin (IL)-1β and tumor necrosis factor (TNF)-α in the peripheral nervous system suggests the possibility of change in pain perception in diabetes. In this study we investigated that continuous delivery of IL10 in the nerve fibers achieved by HSV vector mediated transduction of dorsal root ganglion (DRG) in animals with Type 1 diabetes, blocks the nociceptive and stress responses in the DRG neurons by reducing IL1β expression along with inhibition of phosphorylation of p38 MAPK (mitogen-activated protein kinase) and protein kinase C (PKC). The continuous expression of IL10 also alters Toll like receptor (TLR)-4 expression in the DRG with increased expression of heat shock protein (HSP)-70 in conjunction with the reduction of pain. Taken together, this study suggests that macrophage activation in the peripheral nervous system may be involved in the pathogenesis of pain in Type 1 diabetes and therapeutic benefits of HSV mediated local expression of IL10 in the DRG with the reduction of a number of proinflammatory cytokines, subsequently inhibits the development of painful neuropathy along with a decrease in stress associated markers in the DRG. This basic and preclinical study provides an important evidence for a novel treatment strategy that could lead to a clinical trial for what is currently a treatment resistant complication of diabetes. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. A sensitive, support-vector-machine method for the detection of horizontal gene transfers in viral, archaeal and bacterial genomes.

    Science.gov (United States)

    Tsirigos, Aristotelis; Rigoutsos, Isidore

    2005-01-01

    In earlier work, we introduced and discussed a generalized computational framework for identifying horizontal transfers. This framework relied on a gene's nucleotide composition, obviated the need for knowledge of codon boundaries and database searches, and was shown to perform very well across a wide range of archaeal and bacterial genomes when compared with previously published approaches, such as Codon Adaptation Index and C + G content. Nonetheless, two considerations remained outstanding: we wanted to further increase the sensitivity of detecting horizontal transfers and also to be able to apply the method to increasingly smaller genomes. In the discussion that follows, we present such a method, Wn-SVM, and show that it exhibits a very significant improvement in sensitivity compared with earlier approaches. Wn-SVM uses a one-class support-vector machine and can learn using rather small training sets. This property makes Wn-SVM particularly suitable for studying small-size genomes, similar to those of viruses, as well as the typically larger archaeal and bacterial genomes. We show experimentally that the new method results in a superior performance across a wide range of organisms and that it improves even upon our own earlier method by an average of 10% across all examined genomes. As a small-genome case study, we analyze the genome of the human cytomegalovirus and demonstrate that Wn-SVM correctly identifies regions that are known to be conserved and prototypical of all beta-herpesvirinae, regions that are known to have been acquired horizontally from the human host and, finally, regions that had not up to now been suspected to be horizontally transferred. Atypical region predictions for many eukaryotic viruses, including the alpha-, beta- and gamma-herpesvirinae, and 123 archaeal and bacterial genomes, have been made available online at http://cbcsrv.watson.ibm.com/HGT_SVM/.

  9. Persistence of non-viral vector mediated RPE65 expression: case for viability as a gene transfer therapy for RPE-based diseases.

    Science.gov (United States)

    Koirala, Adarsha; Conley, Shannon M; Makkia, Rasha; Liu, Zhao; Cooper, Mark J; Sparrow, Janet R; Naash, Muna I

    2013-12-28

    Mutations in the retinal pigment epithelium (RPE) gene RPE65 are associated with multiple blinding diseases including Leber's Congenital Amaurosis (LCA). Our goal has been to develop persistent, effective non-viral genetic therapies to treat this condition. Using precisely engineered DNA vectors and high capacity compacted DNA nanoparticles (NP), we previously demonstrated that both plasmid and NP forms of VMD2-hRPE65-S/MAR improved the disease phenotypes in an rpe65(-/-) model of LCA up to 6 months post-injection (PI), however the duration of this treatment efficacy was not established. Here, we test the ability of these vectors to sustain gene expression and phenotypic improvement for the life of the animal. NPs or naked DNA were subretinally injected in rpe65(-/-) mice at postnatal day (P) 16 and evaluated at 15 months PI. Quantitative real-time PCR (qRT-PCR) and immunofluorescence were performed at PI-15 months and demonstrated appreciable expression of transferred RPE65 (levels were 32% of wild-type [WT] for NPs and 44% of WT for naked DNA). No reduction in expression at the message level was observed from PI-6 month data. Spectral electroretinography (ERG) demonstrated significant improvement in cone ERG amplitudes in treated versus uninjected animals. Most importantly, we also observed reduced fundus autofluorescence in the eyes injected with NP and naked DNA compared to uninjected counterparts. Consistent with these observations, biochemical studies showed a reduction in the accumulation of toxic retinyl esters in treated mice, suggesting that the transferred hRPE65 was functional. These critical results indicate that both NP and uncompacted plasmid VMD2-hRPE65-S/MAR can mediate persistent, long-term improvement in an RPE-associated disease phenotype, and suggest that DNA NPs, which are non-toxic and have a large payload capacity, expand the treatment repertoire available for ocular gene therapy. © 2013.

  10. Ocular and systemic safety of a recombinant AAV8 vector for X-linked retinoschisis gene therapy: GLP studies in rabbits and Rs1-KO mice

    Directory of Open Access Journals (Sweden)

    Dario Marangoni

    2016-01-01

    Full Text Available X-linked retinoschisis (XLRS is a retinal disease caused by mutations in the gene encoding the protein retinoschisin (RS1 and is one of the most common causes of macular degeneration in young men. Our therapeutic approach for XLRS is based on the administration of AAV8-scRS/IRBPhRS, an adeno-associated viral vector coding the human RS1 protein, via the intravitreal (IVT route. Two Good Laboratory Practice studies, a 9-month study in New Zealand White rabbits (n = 124 injected with AAV8-scRS/IRBPhRS at doses of 2E9, 2E10, 2E11, and 1.5E12 vector genomes/eye (vg/eye, and a 6-month study in Rs1-KO mice (n = 162 dosed with 2E9 and 2E10 vg/eye of the same vector were conducted to assess ocular and systemic safety. A self-resolving, dose-dependent vitreal inflammation was the main ocular finding, and except for a single rabbit dosed with 1.5E12 vg/eye, which showed a retinal detachment, no other ocular adverse event was reported. Systemic toxicity was not identified in either species. Biodistribution analysis in Rs1-KO mice detected spread of vector genome in extraocular tissues, but no evidence of organ or tissues damage was found. These studies indicate that IVT administration of AAV8-scRS/IRBPhRS is safe and well tolerated and support its advancement into a phase 1/2a clinical trial for XLRS.

  11. Evaluation of the Protective Efficacy of Recombinant Vesicular Stomatitis Virus Vectors Against Marburg Hemorrhagic Fever in Nonhuman Primate Models

    Science.gov (United States)

    2007-01-19

    therefore raises questions regarding its vaccine efficiency ( Brandt , Kim et al. 1969; Schulick, Vassalli et al. 1997; Piedra, Poveda et al. 1998...fever in non-human primates. Nature 424, 681-4 (2003). 11. Brandt , C.D. et al. Infections in 18,000 infants and children in a controlled study of...viral progeny ( Gerhard W 2001), and cell-cell transmission of viruses (Pantaleo, Demarest et al. 1995; Burioni, Williamson et al. 1994) have been

  12. Biodegradable Nanoparticles of mPEG-PLGA-PLL Triblock Copolymers as Novel Non-Viral Vectors for Improving siRNA Delivery and Gene Silencing

    Directory of Open Access Journals (Sweden)

    Qiu-Sheng Shi

    2012-01-01

    Full Text Available Degradation of mRNA by RNA interference is one of the most powerful and specific mechanisms for gene silencing. However, insufficient cellular uptake and poor stability have limited its usefulness. Here, we report efficient delivery of siRNA via the use of biodegradable nanoparticles (NPs made from monomethoxypoly(ethylene glycol-poly(lactic-co-glycolic acid-poly-l-lysine (mPEG-PLGA-PLL triblock copolymers. Various physicochemical properties of mPEG-PLGA-PLL NPs, including morphology, size, surface charge, siRNA encapsulation efficiency, and in vitro release profile of siRNA from NPs, were characterized by scanning electron microscope, particle size and zeta potential analyzer, and high performance liquid chromatography. The levels of siRNA uptake and targeted gene inhibition were detected in human lung cancer SPC-A1-GFP cells stably expressing green fluorescent protein. Examination of the cultured SPC-A1-GFP cells with fluorescent microscope and flow cytometry showed NPs loading Cy3-labeled siRNA had much higher intracellular siRNA delivery efficiencies than siRNA alone and Lipofectamine-siRNA complexes. The gene silencing efficiency of mPEG-PLGA-PLL NPs was higher than that of commercially available transfecting agent Lipofectamine while showing no cytotoxicity. Thus, the current study demonstrates that biodegradable NPs of mPEG-PLGA-PLL triblock copolymers can be potentially applied as novel non-viral vectors for improving siRNA delivery and gene silencing.

  13. Biodegradable nanoparticles of mPEG-PLGA-PLL triblock copolymers as novel non-viral vectors for improving siRNA delivery and gene silencing.

    Science.gov (United States)

    Du, Jing; Sun, Ying; Shi, Qiu-Sheng; Liu, Pei-Feng; Zhu, Ming-Jie; Wang, Chun-Hui; Du, Lian-Fang; Duan, You-Rong

    2012-01-01

    Degradation of mRNA by RNA interference is one of the most powerful and specific mechanisms for gene silencing. However, insufficient cellular uptake and poor stability have limited its usefulness. Here, we report efficient delivery of siRNA via the use of biodegradable nanoparticles (NPs) made from monomethoxypoly(ethylene glycol)-poly(lactic-co-glycolic acid)-poly-l-lysine (mPEG-PLGA-PLL) triblock copolymers. Various physicochemical properties of mPEG-PLGA-PLL NPs, including morphology, size, surface charge, siRNA encapsulation efficiency, and in vitro release profile of siRNA from NPs, were characterized by scanning electron microscope, particle size and zeta potential analyzer, and high performance liquid chromatography. The levels of siRNA uptake and targeted gene inhibition were detected in human lung cancer SPC-A1-GFP cells stably expressing green fluorescent protein. Examination of the cultured SPC-A1-GFP cells with fluorescent microscope and flow cytometry showed NPs loading Cy3-labeled siRNA had much higher intracellular siRNA delivery efficiencies than siRNA alone and Lipofectamine-siRNA complexes. The gene silencing efficiency of mPEG-PLGA-PLL NPs was higher than that of commercially available transfecting agent Lipofectamine while showing no cytotoxicity. Thus, the current study demonstrates that biodegradable NPs of mPEG-PLGA-PLL triblock copolymers can be potentially applied as novel non-viral vectors for improving siRNA delivery and gene silencing.

  14. Quantitative analysis of axon bouton distribution of subthalamic nucleus neurons in the rat by single neuron visualization with a viral vector.

    Science.gov (United States)

    Koshimizu, Yoshinori; Fujiyama, Fumino; Nakamura, Kouichi C; Furuta, Takahiro; Kaneko, Takeshi

    2013-06-15

    The subthalamic nucleus (STN) of the basal ganglia plays a key role in motor control, and STN efferents are known to mainly target the external segment of the globus pallidus (GPe), entopeduncular nucleus (Ep), and substantia nigra (SN) with some axon collaterals to the other regions. However, it remains to be clarified how each STN neuron projects axon fibers and collaterals to those target nuclei of the STN. Here we visualized the whole axonal arborization of single STN neurons in the rat brain by using a viral vector expressing membrane-targeted green fluorescent protein, and examined the distribution of axon boutons in those target nuclei. The vast majority (8-9) of 10 reconstructed STN neurons projected to the GPe, SN, caudate-putamen (CPu), and Ep, which received, on average ± SD, 457 ± 425, 400 ± 347, 126 ± 143, and 106 ± 100 axon boutons per STN neuron, respectively. Furthermore, the density of axon boutons in the GPe was highest among these nuclei. Although these target nuclei were divided into calbindin-rich and -poor portions, STN projection showed no exclusive preference for those portions. Since STN neurons mainly projected not only to the GPe, SN, and Ep but also to the CPu, the subthalamostriatal projection might serve as a positive feedback path for the striato-GPe-subthalamic disinhibitory pathway, or work as another route of cortical inputs to the striatum through the corticosubthalamostriatal disynaptic excitatory pathway.

  15. Isolation of bluetongue virus serotype 1 from Culicoides vector captured in livestock farms and sequence analysis of the viral genome segment-2.

    Science.gov (United States)

    Dadawala, A I; Biswas, S K; Rehman, W; Chand, K; De, A; Mathapati, B S; Kumar, P; Chauhan, H C; Chandel, B S; Mondal, B

    2012-08-01

    Bluetongue virus serotype-1 (BTV-1) was isolated from Culicoides oxystoma vectors captured on livestock farms in two places of Gujarat, India. The viruses were isolated on BHK-21 cells, which produced characteristic BTV-related cytopathic effects between 24 and 48 h post-infection. Virus antigen was demonstrated in infected cells at different passage by a BTV-specific sandwich ELISA. Further, polyacrylamide gel electrophoresis and silver staining of viral genomic RNA revealed ten double-stranded RNA segments characteristic of BTV. Serotype of the isolates was identified by virus neutralization and PCR coupled with sequencing. The isolates were designated as SKN-7 and SKN-8 and their genome segment-2 (VP2) were sequenced. Phylogenetic analyses revealed very close relationship between them although they are not identical. SKN-8 showed closer relationship with a recently isolated BTV-1 from goat. Bluetongue virus was earlier isolated from Culicoides in adjacent state more than 20 years ago, although the serotype of the virus was not determined.

  16. Different cortical projections from three subdivisions of the rat lateral posterior thalamic nucleus: a single-neuron tracing study with viral vectors.

    Science.gov (United States)

    Nakamura, Hisashi; Hioki, Hiroyuki; Furuta, Takahiro; Kaneko, Takeshi

    2015-05-01

    The lateral posterior thalamic nucleus (LP) is one of the components of the extrageniculate pathway in the rat visual system, and is cytoarchitecturally divided into three subdivisions--lateral (LPl), rostromedial (LPrm), and caudomedial (LPcm) portions. To clarify the differences in the dendritic fields and axonal arborisations among the three subdivisions, we applied a single-neuron labeling technique with viral vectors to LP neurons. The proximal dendrites of LPl neurons were more numerous than those of LPrm and LPcm neurons, and LPrm neurons tended to have wider dendritic fields than LPl neurons. We then analysed the axonal arborisations of LP neurons by reconstructing the axon fibers in the cortex. The LPl, LPrm and LPcm were different from one another in terms of the projection targets--the main target cortical regions of LPl and LPrm neurons were the secondary and primary visual areas, whereas those of LPcm neurons were the postrhinal and temporal association areas. Furthermore, the principal target cortical layers of LPl neurons in the visual areas were middle layers, but that of LPrm neurons was layer 1. This indicates that LPl and LPrm neurons can be categorised into the core and matrix types of thalamic neurons, respectively, in the visual areas. In addition, LPl neurons formed multiple axonal clusters within the visual areas, whereas the fibers of LPrm neurons were widely and diffusely distributed. It is therefore presumed that these two types of neurons play different roles in visual information processing by dual thalamocortical innervation of the visual areas.

  17. TMV-Gate vectors: gateway compatible tobacco mosaic virus based expression vectors for functional analysis of proteins.

    Science.gov (United States)

    Kagale, Sateesh; Uzuhashi, Shihomi; Wigness, Merek; Bender, Tricia; Yang, Wen; Borhan, M Hossein; Rozwadowski, Kevin

    2012-01-01

    Plant viral expression vectors are advantageous for high-throughput functional characterization studies of genes due to their capability for rapid, high-level transient expression of proteins. We have constructed a series of tobacco mosaic virus (TMV) based vectors that are compatible with Gateway technology to enable rapid assembly of expression constructs and exploitation of ORFeome collections. In addition to the potential of producing recombinant protein at grams per kilogram FW of leaf tissue, these vectors facilitate either N- or C-terminal fusions to a broad series of epitope tag(s) and fluorescent proteins. We demonstrate the utility of these vectors in affinity purification, immunodetection and subcellular localisation studies. We also apply the vectors to characterize protein-protein interactions and demonstrate their utility in screening plant pathogen effectors. Given its broad utility in defining protein properties, this vector series will serve as a useful resource to expedite gene characterization efforts.

  18. Silencing of hepatitis C virus replication by a non-viral vector based on solid lipid nanoparticles containing a shRNA targeted to the internal ribosome entry site (IRES).

    Science.gov (United States)

    Torrecilla, Josune; Del Pozo-Rodríguez, Ana; Solinís, María Ángeles; Apaolaza, Paola S; Berzal-Herranz, Beatriz; Romero-López, Cristina; Berzal-Herranz, Alfredo; Rodríguez-Gascón, Alicia

    2016-10-01

    Gene silencing mediated by RNAi has gained increasing interest as an alternative for the treatment of infectious diseases such as refractory hepatitis C virus (HCV) infection. In this work we have designed and evaluated a non-viral vector based on solid lipid nanoparticles (SLN) bearing hyaluronic acid, protamine and a short hairpin RNA (shRNA74) targeted to the Internal Ribosome Entry Site (IRES) of the HCV. The vector was able to inhibit the expression of the HCV IRES in Huh-7 cells, with the inhibition level dependent on the shRNA74 to SLN ratio and on the shRNA74 dose added to the culture cells. The nanocarrier was also able to inhibit the replication in human hepatoma cells supporting a subgenomic HCV replicon (Huh-7 NS3-3'). The vector was quickly and efficiently internalized by the cells, and endocytosis was the most productive uptake mechanism for silencing. Clathrin-mediated endocytosis and to a lesser extent caveolae/lipid raft-mediated endocytosis were identified as endocytic mechanisms involved in the cell uptake. Internalization via the CD44 receptor was also involved, although this entry route seems to be less productive for silencing than endocytosis. The vector did not induce either hemolysis or agglutination of red cells in vitro, which was indicative of good biocompatibility. In summary, we have shown for the first time the ability of a non-viral SLN-based vector to silence a HCV replicon.

  19. A pilot study comparing the development of EIAV Env-specific antibodies induced by DNA/recombinant vaccinia-vectored vaccines and an attenuated Chinese EIAV vaccine.

    Science.gov (United States)

    Meng, Qinglai; Lin, Yuezhi; Ma, Jian; Ma, Yan; Zhao, Liping; Li, Shenwei; Yang, Kai; Zhou, Jianhua; Shen, Rongxian; Zhang, Xiaoyan; Shao, Yiming

    2012-12-01

    Data from successful attenuated lentiviral vaccine studies indicate that fully mature Env-specific antibodies characterized by high titer, high avidity, and the predominant recognition of conformational epitopes are associated with protective efficacy. Although vaccination with a DNA prime/recombinant vaccinia-vectored vaccine boost strategy has been found to be effective in some trials with non-human primate/simian/human immunodeficiency virus (SHIV) models, it remains unclear whether this vaccination strategy could elicit mature equine infectious anemia virus (EIAV) Env-specific antibodies, thus protecting vaccinated horses against EIAV infection. Therefore, in this pilot study we vaccinated horses using a strategy based on DNA prime/recombinant Tiantan vaccinia (rTTV)-vectored vaccines encoding EIAV env and gag genes, and observed the development of Env-specific antibodies, neutralizing antibodies, and p26-specific antibodies. Vaccination with DNA induced low titer, low avidity, and the predominant recognition of linear epitopes by Env-specific antibodies, which was enhanced by boosting vaccinations with rTTV vaccines. However, the maturation levels of Env-specific antibodies induced by the DNA/rTTV vaccines were significantly lower than those induced by the attenuated vaccine EIAV(FDDV). Additionally, DNA/rTTV vaccines did not elicit broadly neutralizing antibodies. After challenge with a virulent EIAV strain, all of the vaccinees and control horses died from EIAV disease. These data indicate that the regimen of DNA prime/rTTV vaccine boost did not induce mature Env-specific antibodies, which might have contributed to immune protection failure.

  20. Enhanced immunity against classical swine fever in pigs induced by prime-boost immunization using an alphavirus replicon-vectored DNA vaccine and a recombinant adenovirus.

    Science.gov (United States)

    Sun, Yuan; Li, Na; Li, Hong-Yu; Li, Miao; Qiu, Hua-Ji

    2010-09-15

    Classical swine fever (CSF) - caused by the classical swine fever virus (CSFV) - is a fatal disease of pigs that is responsible for extensive losses to the swine industry worldwide. We had demonstrated previously that a prime-boost vaccination strategy using an alphavirus (Semliki Forest virus, SFV) replicon-vectored DNA vaccine (pSFV1CS-E2) and a recombinant adenovirus (rAdV-E2) expressing the E2 glycoprotein of CSFV induced enhanced immune responses in a mouse model. In this study, we evaluated further the efficacy of the heterologous prime-boost immunization approach in pigs, the natural host of CSFV. The results showed that the pigs (n=5) receiving pSFV1CS-E2/rAdV-E2 heterologous prime-boost immunization developed significantly higher titers of CSFV-specific neutralizing antibodies and comparable CD4(+) and CD8(+) T-cell proliferation, compared to the pigs receiving double immunizations with rAdV-E2 alone. When challenged with virulent CSFV Shimen strain, the pigs of the heterologous prime-boost group did not show clinical symptoms or viremia, which were observed in one of the 5 pigs immunized with rAdV-E2 alone and all the 5 control pigs immunized with an empty adenovirus. The results demonstrate that the heterologous DNA prime and recombinant adenovirus boost strategy can induce solid protective immunity.

  1. Canine Recombinant Adenovirus Vector Induces an Immunogenicity-Related Gene Expression Profile in Skin-Migrated CD11b+ -Type DCs

    Science.gov (United States)

    Jouneau, Luc; Bourge, Mickael; Bouet-Cararo, Coraline; Bonneau, Michel; Zientara, Stephan; Klonjkowski, Bernard; Schwartz-Cornil, Isabelle

    2012-01-01

    Gene expression profiling of the blood cell response induced early after vaccination has previously been demonstrated to predict the immunogenicity of vaccines. In this study, we evaluated whether the analysis of the gene expression profile of skin-migrated dendritic cells (DCs) could be informative for the in vitro prediction of immunogenicity of vaccine, using canine adenovirus serotype 2 (CAV2) as vaccine vector. CAV2 has been shown to induce immunity to transgenes in several species including sheep and is an interesting alternative to human adenovirus-based vectors, based on the safety records of the parental strain in dogs and the lack of pre-existing immunity in non-host species. Skin-migrated DCs were collected from pseudo-afferent lymph in sheep. Both the CD11b+ -type and CD103+ -type skin-migrated DCs were transduced by CAV2. An analysis of the global gene response to CAV2 in the two skin DC subsets showed that the gene response in CD11b+ -type DCs was far higher and broader than in the CD103+ -type DCs. A newly released integrative analytic tool from Ingenuity systems revealed that the CAV2-modulated genes in the CD11b+ -type DCs clustered in several activated immunogenicity-related functions, such as immune response, immune cell trafficking and inflammation. Thus gene profiling in skin-migrated DC in vitro indicates that the CD11b+ DC type is more responsive to CAV2 than the CD103+ DC type, and provides valuable information to help in evaluating and possibly improving viral vector vaccine effectiveness. PMID:23300693

  2. Canine recombinant adenovirus vector induces an immunogenicity-related gene expression profile in skin-migrated CD11b⁺ -type DCs.

    Directory of Open Access Journals (Sweden)

    Vanessa Contreras

    Full Text Available Gene expression profiling of the blood cell response induced early after vaccination has previously been demonstrated to predict the immunogenicity of vaccines. In this study, we evaluated whether the analysis of the gene expression profile of skin-migrated dendritic cells (DCs could be informative for the in vitro prediction of immunogenicity of vaccine, using canine adenovirus serotype 2 (CAV2 as vaccine vector. CAV2 has been shown to induce immunity to transgenes in several species including sheep and is an interesting alternative to human adenovirus-based vectors, based on the safety records of the parental strain in dogs and the lack of pre-existing immunity in non-host species. Skin-migrated DCs were collected from pseudo-afferent lymph in sheep. Both the CD11b(+ -type and CD103(+ -type skin-migrated DCs were transduced by CAV2. An analysis of the global gene response to CAV2 in the two skin DC subsets showed that the gene response in CD11b(+ -type DCs was far higher and broader than in the CD103(+ -type DCs. A newly released integrative analytic tool from Ingenuity systems revealed that the CAV2-modulated genes in the CD11b(+ -type DCs clustered in several activated immunogenicity-related functions, such as immune response, immune cell trafficking and inflammation. Thus gene profiling in skin-migrated DC in vitro indicates that the CD11b(+ DC type is more responsive to CAV2 than the CD103(+ DC type, and provides valuable information to help in evaluating and possibly improving viral vector vaccine effectiveness.

  3. Immunogenicity of next-generation HPV vaccines in non-human primates: Measles-vectored HPV vaccine versus Pichia pastoris recombinant protein vaccine.

    Science.gov (United States)

    Gupta, Gaurav; Giannino, Viviana; Rishi, Narayan; Glueck, Reinhard

    2016-09-07

    Human papillomavirus (HPV) infection is the most common sexually transmitted disease worldwide. HPVs are oncogenic small double-stranded DNA viruses that are the primary causal agent of cervical cancer and other types of cancers, including in the anus, oropharynx, vagina, vulva, and penis. Prophylactic vaccination against HPV is an attractive strategy for preventing cervical cancer and some other types of cancers. However, there are few safe and effective vaccines against HPV infections. Current first-generation commercial HPV vaccines are expensive to produce and deliver. The goal of this study was to develop an alternate potent HPV recombinant L1-based vaccines by producing HPV virus-like particles into a vaccine that is currently used worldwide. Live attenuated measles virus (MV) vaccines have a well-established safety and efficacy record, and recombinant MV (rMV) produced by reverse genetics may be useful for generating candidate HPV vaccines to meet the needs of the developing world. We studied in non-human primate rMV-vectored HPV vaccine in parallel with a classical alum adjuvant recombinant HPV16L1 and 18L1 protein vaccine produced in Pichia pastoris. A combined prime-boost approach using both vaccines was evaluated, as well as immune interference due to pre-existing immunity against the MV. The humoral immune response induced by the MV, Pichia-expressed vaccine, and their combination as priming and boosting approaches was found to elicit HPV16L1 and 18L1 specific total IgG and neutralizing antibody titres. Pre-existing antibodies against measles did not prevent the immune response against HPV16L1 and 18L1.

  4. Comparative Immunization in BALB/c Mice with Recombinant Replication-Defective Adenovirus Vector and DNA Plasmid Expressing a SARS-CoV Nucleocapsid Protein Gene

    Institute of Scientific and Technical Information of China (English)

    Chunling Ma; Kun Yao; Feng Zhou; Minsheng Zhu

    2006-01-01

    In order to investigate immunogenicity in the induction of humoral and cellular immune responses, severe acute respiratory syndrome associated coronavirus (SARS-CoV)-N gene recombinant replication-defective adenoviral vector, rAd-N, was generated and immunized BALB/c mice in a pcDNA3.1-N prime-rAd-N boost regimen. After humoral and cellular immune response detection, different levels of SARS-CoV N protein specific antibodies and interferon-γ (IFN-γ) secretion are shown compared to controls. The humoral immune response was induced more effectively by the DNA priming and recombinant adenovirus boosting regimen. There is a significant difference between heterogeneous and homologous vaccinations. The heterogeneous combinations were all higher than those of the homologous combinations in the induction of anti-N antibody response. Among the three heterogeneous combinations, pcDNA3.1-N/pcDNA3.1-N/pcDNA3.1-N/rAd-N induced the strongest antibody response. In the induction of IFN-γ production, the homologous combination of rAd-N/rAd-N/rAd-N/rAd- N was significantly stronger than that of pcDNA3.1-N/pcDNA3. 1-N/pcDNA3.1-N/pcDNA3.1-N, but was relatively weaker than the heterogeneous combination of pcDAN3.1-N/pcDAN3.1-N/pcDAN3.1-N/rAd-N. This combination was a most efficient immunization regimen in induction of SARS-CoV-N-specific (IFN-γ) secretion just as the antibody response. These results suggest that DNA immunization followed by recombinant adenovirus boosting could be used as a potential SARS-CoV vaccine.

  5. Chromatography purification of canine adenoviral vectors.

    Science.gov (United States)

    Segura, María Mercedes; Puig, Meritxell; Monfar, Mercè; Chillón, Miguel

    2012-06-01

    Canine adenovirus vectors (CAV2) are currently being evaluated for gene therapy, oncolytic virotherapy, and as vectors for recombinant vaccines. Despite the need for increasing volumes of purified CAV2 preparations for preclinical and clinical testing, their purification still relies on the use of conventional, scale-limited CsCl ultracentrifugation techniques. A complete downstream processing strategy for CAV2 vectors based on membrane filtration and chromatography is reported here. Microfiltration and ultra/diafiltration are selected for clarification and concentration of crude viral stocks containing both intracellular and extracellular CAV2 particles. A DNase digestion step is introduced between ultrafiltration and diafiltration operations. At these early stages, concentration of vector stocks with good recovery of viral particles (above 80%) and removal of a substantial amount of protein and nucleic acid contaminants is achieved. The ability of various chromatography techniques to isolate CAV2 particles was evaluated. Hydrophobic interaction chromatography using a Fractogel propyl tentacle resin was selected as a first chromatography step, because it allows removal of the bulk of contaminating proteins with high CAV2 yields (88%). An anion-exchange chromatography step using monolithic supports is further introduced to remove the remaining contaminants with good recovery of CAV2 particles (58-69%). The main CAV2 viral structural components are visualized in purified preparations by electrophoresis analyses. Purified vector stocks contained intact icosahedral viral particles, low contamination with empty viral capsids (10%), and an acceptable total-to-infectious particle ratio (below 30). The downstream processing strategy that was developed allows preparation of large volumes of high-quality CAV2 stocks.

  6. Hybrid lentivirus-phiC31-int-NLS vector allows site-specific recombination in murine and human cells but induces DNA damage.

    Directory of Open Access Journals (Sweden)

    Nicolas Grandchamp

    Full Text Available Gene transfer allows transient or permanent genetic modifications of cells for experimental or therapeutic purposes. Gene delivery by HIV-derived lentiviral vector (LV is highly effective but the risk of insertional mutagenesis is important and the random/uncontrollable integration of the DNA vector can deregulate the cell transcriptional activity. Non Integrative Lentiviral Vectors (NILVs solve this issue in non-dividing cells, but they do not allow long term expression in dividing cells. In this context, obtaining stable expression while avoiding the problems inherent to unpredictable DNA vector integration requires the ability to control the integration site. One possibility is to use the integrase of phage phiC31 (phiC31-int which catalyzes efficient site-specific recombination between the attP site in the phage genome and the chromosomal attB site of its Streptomyces host. Previous studies showed that phiC31-int is active in many eukaryotic cells, such as murine or human cells, and directs the integration of a DNA substrate into pseudo attP sites (pattP which are homologous to the native attP site. In this study, we combined the efficiency of NILV for gene delivery and the specificity of phiC31-int for DNA substrate integration to engineer a hybrid tool for gene transfer with the aim of allowing long term expression in dividing and non-dividing cells preventing genotoxicity. We demonstrated the feasibility to target NILV integration in human and murine pattP sites with a dual NILV vectors system: one which delivers phiC31-int, the other which constitute the substrate containing an attB site in its DNA sequence. These promising results are however alleviated by the occurrence of significant DNA damages. Further improvements are thus required to prevent chromosomal rearrangements for a therapeutic use of the system. However, its use as a tool for experimental applications such as transgenesis is already applicable.

  7. Recombinant MVA vaccines: dispelling the myths.

    Science.gov (United States)

    Cottingham, Matthew G; Carroll, Miles W

    2013-09-06

    Diseases such as HIV/AIDS, tuberculosis, malaria and cancer are prime targets for prophylactic or therapeutic vaccination, but have proven partially or wholly resistant to traditional approaches to vaccine design. New vaccines based on recombinant viral vectors expressing a foreign antigen are under intense development for these and other indications. One of the most advanced and most promising vectors is the attenuated, non-replicating poxvirus MVA (modified vaccinia virus Ankara), a safer derivative of the uniquely successful smallpox vaccine. Despite the ability of recombinant MVA to induce potent humoral and cellular immune responses against transgenic antigen in humans, especially when used as the latter element of a heterologous prime-boost regimen, doubts are occasionally expressed about the ultimate feasibility of this approach. In this review, five common misconceptions over recombinant MVA are discussed, and evidence is cited to show that recombinant MVA is at least sufficiently genetically stable, manufacturable, safe, and immunogenic (even in the face of prior anti-vector immunity) to warrant reasonable hope over the feasibility of large-scale deployment, should useful levels of protection against target pathogens, or therapeutic benefit for cancer, be demonstrated in efficacy trials.

  8. Exclusive and common targets of neostriatofugal projections of rat striosome neurons: a single neuron-tracing study using a viral vector.

    Science.gov (United States)

    Fujiyama, Fumino; Sohn, Jaerin; Nakano, Takashi; Furuta, Takahiro; Nakamura, Kouichi C; Matsuda, Wakoto; Kaneko, Takeshi

    2011-02-01

    The rat neostriatum has a mosaic organization composed of striosome/patch compartments embedded in a more extensive matrix compartment, which are distinguished from each other by the input-output organization as well as by the expression of many molecular markers. The matrix compartment gives rise to the dual γ-aminobutyric acid (GABA)ergic striatofugal systems, i.e. direct and indirect pathway neurons, whereas the striosome compartment is considered to involve direct pathway neurons alone. Although the whole axonal arborization of matrix striatofugal neurons has been examined in vivo by intracellular staining, that of striosome neurons has never been studied at the single neuron level. In the present study, the axonal arborizations of single striosome projection neurons in rat neostriatum were visualized in their entirety using a viral vector expressing membrane-targeted green fluorescent protein, and compared with that of matrix projection neurons. We found that not only matrix but also striosome compartments contained direct and indirect pathway neurons. Furthermore, only striatonigral neurons in the striosome compartment projected directly to the substantia nigra pars compacta (SNc), although they sent a substantial number of axon collaterals to the globus pallidus, entopeduncular nucleus and/or substantia nigra pars reticulata. These results suggest that striosome neurons play a more important role in the formation of reward-related signals of SNc dopaminergic neurons than do matrix neurons. Together with data from previous studies in the reinforcement learning theory, our results suggest that these direct and indirect striosome-SNc pathways together with nigrostriatal dopaminergic neurons may help striosome neurons to acquire the state-value function.

  9. First evaluation of an influenza viral vector based Brucella abortus vaccine in sheep and goats: Assessment of safety, immunogenicity and protective efficacy against Brucella melitensis infection.

    Science.gov (United States)

    Tabynov, Kaissar; Yespembetov, Bolat; Matikhan, Nurali; Ryskeldinova, Sholpan; Zinina, Nadezhda; Kydyrbayev, Zhailaubay; Assanzhanova, Nurika; Tabynov, Kairat; Renukaradhya, Gourapura J; Mukhitdinova, Gulnara; Sansyzbay, Abylai

    2016-12-25

    Previously we developed and evaluated a candidate influenza viral vector based Brucella abortus vaccine (Flu-BA) administered with a potent adjuvant Montanide Gel01 in cattle, which was found safe and highly effective. This study was aimed to establish a proof-of-concept of the efficacy of Flu-BA vaccine formulation in sheep and goats. We vaccinated sheep and goats with Flu-BA vaccine and as a positive control vaccinated a group of animals with a commercial B. melitensis Rev.1 vaccine. Clinically, both Flu-BA and Rev.1 vaccines were found safe. Serological analysis showed the animals received Flu-BA vaccine did not induce antibody response against Brucella Omp16 and L7/L12 proteins during the period of our study (56days post-initial vaccination, PIV). But observed significant antigen-specific T cell response indicated by increased lymphocyte stimulation index and enhanced secretion of IFN-γ at day 56 PIV in Flu-BA group. The Flu-BA vaccinated animals completely protected 57.1% of sheep and 42.9% of goats against B. melitensis 16M challenge. The severity of brucellosis in terms of infection index and colonization of Brucella in tissues was significantly lower in the Flu-BA group compared to negative control animals group. Nevertheless, positive control commercial Rev.1 vaccine provided strong antigen-specific T cell immunity and protection against B. melitensis 16M infection. We conclude that the Flu-BA vaccine induces a significant antigen-specific T-cell response and provides complete protection in approximately 50% of sheep and goats against B. melitensis 16M infection. Further investigations are needed to improve the efficacy of Flu-BA and explore its practical application in small ruminants.

  10. Hexon-modified recombinant E1-deleted adenoviral vectors as bivalent vaccine carriers for Coxsackievirus A16 and Enterovirus 71.

    Science.gov (United States)

    Zhang, Chao; Yang, Yong; Chi, Yudan; Yin, Jieyun; Yan, Lijun; Ku, Zhiqiang; Liu, Qingwei; Huang, Zhong; Zhou, Dongming

    2015-09-22

    Hand, foot and mouth disease (HFMD) is a major public health concern in Asia; more efficient vaccines against HFMD are urgently required. Adenoviral (Ad) capsids have been used widely for the presentation of foreign antigens to induce specific immune responses in the host. Here, we describe a novel bivalent vaccine for HFMD based on the hexon-modified, E1-deleted chimpanzee adenovirus serotype 68 (AdC68). The novel vaccine candidate was generated by incorporating the neutralising epitope of Coxsackievirus A16 (CA16), PEP71, into hypervariable region 1 (HVR1), and a shortened neutralising epitope of Enterovirus 71 (EV71), sSP70, into HVR2 of the AdC68 hexon. In order to enhance the immunogenicity of EV71, VP1 of EV71 was cloned into the E1-region of the AdC68 vectors. The results demonstrated that these two epitopes