Large-scale production of lentiviral vector in a closed system hollow fiber bioreactor

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Jonathan Sheu

Full Text Available Lentiviral vectors are widely used in the field of gene therapy as an effective method for permanent gene delivery. While current methods of producing small scale vector batches for research purposes depend largely on culture flasks, the emergence and popularity of lentiviral vectors in translational, preclinical and clinical research has demanded their production on a much larger scale, a task that can be difficult to manage with the numbers of producer cell culture flasks required for large volumes of vector. To generate a large scale, partially closed system method for the manufacturing of clinical grade lentiviral vector suitable for the generation of induced pluripotent stem cells (iPSCs, we developed a method employing a hollow fiber bioreactor traditionally used for cell expansion. We have demonstrated the growth, transfection, and vector-producing capability of 293T producer cells in this system. Vector particle RNA titers after subsequent vector concentration yielded values comparable to lentiviral iPSC induction vector batches produced using traditional culture methods in 225 cm2 flasks (T225s and in 10-layer cell factories (CF10s, while yielding a volume nearly 145 times larger than the yield from a T225 flask and nearly three times larger than the yield from a CF10. Employing a closed system hollow fiber bioreactor for vector production offers the possibility of manufacturing large quantities of gene therapy vector while minimizing reagent usage, equipment footprint, and open system manipulation.

Lentiviral Vectors for Cancer Immunotherapy and Clinical Applications

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David Escors

2013-07-01

Full Text Available The success of immunotherapy against infectious diseases has shown us the powerful potential that such a treatment offers, and substantial work has been done to apply this strategy in the fight against cancer. Cancer is however a fiercer opponent than pathogen-caused diseases due to natural tolerance towards tumour associated antigens and tumour-induced immunosuppression. Recent gene therapy clinical trials with viral vectors have shown clinical efficacy in the correction of genetic diseases, HIV and cancer. The first successful gene therapy clinical trials were carried out with onco(g-retroviral vectors but oncogenesis by insertional mutagenesis appeared as a serious complication. Lentiviral vectors have emerged as a potentially safer strategy, and recently the first clinical trial of patients with advanced leukemia using lentiviral vectors has proven successful. Additionally, therapeutic lentivectors have shown clinical efficacy for the treatment of HIV, X-linked adrenoleukodystrophy, and b-thalassaemia. This review aims at describing lentivectors and how they can be utilized to boost anti-tumour immune responses by manipulating the effector immune cells.

Lentiviral Vectors for Cancer Immunotherapy and Clinical Applications

Energy Technology Data Exchange (ETDEWEB)

Liechtenstein, Therese, E-mail: t.liechtenstein.12@ucl.ac.uk [University College London, 5 University Street, London, WC1E 6JF (United Kingdom); Perez-Janices, Noemi; Escors, David [University College London, 5 University Street, London, WC1E 6JF (United Kingdom); Navarrabiomed Fundacion Miguel Servet, 3 Irunlarrea St., Hospital Complex of Navarra, 31008 Pamplona, Navarra (Spain)

2013-07-02

The success of immunotherapy against infectious diseases has shown us the powerful potential that such a treatment offers, and substantial work has been done to apply this strategy in the fight against cancer. Cancer is however a fiercer opponent than pathogen-caused diseases due to natural tolerance towards tumour associated antigens and tumour-induced immunosuppression. Recent gene therapy clinical trials with viral vectors have shown clinical efficacy in the correction of genetic diseases, HIV and cancer. The first successful gene therapy clinical trials were carried out with onco(γ-)retroviral vectors but oncogenesis by insertional mutagenesis appeared as a serious complication. Lentiviral vectors have emerged as a potentially safer strategy, and recently the first clinical trial of patients with advanced leukemia using lentiviral vectors has proven successful. Additionally, therapeutic lentivectors have shown clinical efficacy for the treatment of HIV, X-linked adrenoleukodystrophy, and β-thalassaemia. This review aims at describing lentivectors and how they can be utilized to boost anti-tumour immune responses by manipulating the effector immune cells.

Lentiviral Vectors for Cancer Immunotherapy and Clinical Applications

International Nuclear Information System (INIS)

Liechtenstein, Therese; Perez-Janices, Noemi; Escors, David

2013-01-01

The success of immunotherapy against infectious diseases has shown us the powerful potential that such a treatment offers, and substantial work has been done to apply this strategy in the fight against cancer. Cancer is however a fiercer opponent than pathogen-caused diseases due to natural tolerance towards tumour associated antigens and tumour-induced immunosuppression. Recent gene therapy clinical trials with viral vectors have shown clinical efficacy in the correction of genetic diseases, HIV and cancer. The first successful gene therapy clinical trials were carried out with onco(γ-)retroviral vectors but oncogenesis by insertional mutagenesis appeared as a serious complication. Lentiviral vectors have emerged as a potentially safer strategy, and recently the first clinical trial of patients with advanced leukemia using lentiviral vectors has proven successful. Additionally, therapeutic lentivectors have shown clinical efficacy for the treatment of HIV, X-linked adrenoleukodystrophy, and β-thalassaemia. This review aims at describing lentivectors and how they can be utilized to boost anti-tumour immune responses by manipulating the effector immune cells

Lentiviral CRISPR/Cas9 vector mediated miR-21 gene editing inhibits the epithelial to mesenchymal transition in ovarian cancer cells.

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Huo, Wenying; Zhao, Guannan; Yin, Jinggang; Ouyang, Xuan; Wang, Yinan; Yang, Chuanhe; Wang, Baojing; Dong, Peixin; Wang, Zhixiang; Watari, Hidemichi; Chaum, Edward; Pfeffer, Lawrence M; Yue, Junming

2017-01-01

CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats) mediated genome editing is a powerful approach for loss of function studies. Here we report that lentiviral CRISPR/Cas9 vectors are highly efficient in introducing mutations in the precursor miRNA sequence, thus leading to the loss of miRNA expression and function. We constructed four different lentiviral CRISPR/Cas9 vectors that target different regions of the precursor miR-21 sequence and found that these lentiviral CRISPR/Cas9 miR-21 gRNA vectors induced mutations in the precursor sequences as shown by DNA surveyor mutation assay and Sanger sequencing. Two miR-21 lentiviral CRISPR/Cas9 gRNA vectors were selected to probe miR-21 function in ovarian cancer SKOV3 and OVCAR3 cell lines. Our data demonstrate that disruption of pre-miR-21 sequences leads to reduced cell proliferation, migration and invasion. Moreover, CRISPR/Cas9-mediated miR-21 gene editing sensitizes both SKOV3 and OVCAR3 cells to chemotherapeutic drug treatment. Disruption of miR-21 leads to the inhibition of epithelial to mesenchymal transition (EMT) in both SKOV3 and OVCAR3 cells as evidenced by the upregulation of epithelial cell marker E-cadherin and downregulation of mesenchymal marker genes, vimentin and Snai2. The miR-21 target genes PDCD4 and SPRY2 were upregulated in cells transduced with miR-21gRNAs compared to controls. Our study indicates that lentiviral CRISPR/Cas9-mediated miRNA gene editing is an effective approach to address miRNA function, and disruption of miR-21 inhibits EMT in ovarian cancer cells.

Multicistronic lentiviral vectors containing the FMDV 2A cleavage factor demonstrate robust expression of encoded genes at limiting MOI

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Margison Geoffrey P

2006-03-01

Full Text Available Abstract Background A number of gene therapy applications would benefit from vectors capable of expressing multiple genes. In this study we explored the feasibility and efficiency of expressing two or three transgenes in HIV-1 based lentiviral vector. Bicistronic and tricistronic self-inactivating lentiviral vectors were constructed employing the internal ribosomal entry site (IRES sequence of encephalomyocarditis virus (EMCV and/or foot-and-mouth disease virus (FMDV cleavage factor 2A. We employed enhanced green fluorescent protein (eGFP, O6-methylguanine-DNA-methyltransferase (MGMT, and homeobox transcription factor HOXB4 as model genes and their expression was detected by appropriate methods including fluorescence microscopy, flow cytometry, immunocytochemistry, biochemical assay, and western blotting. Results All the multigene vectors produced high titer virus and were able to simultaneously express two or three transgenes in transduced cells. However, the level of expression of individual transgenes varied depending on: the transgene itself; its position within the construct; the total number of transgenes expressed; the strategy used for multigene expression and the average copy number of pro-viral insertions. Notably, at limiting MOI, the expression of eGFP in a bicistronic vector based on 2A was ~4 times greater than that of an IRES based vector. Conclusion The small and efficient 2A sequence can be used alone or in combination with an IRES for the construction of multicistronic lentiviral vectors which can express encoded transgenes at functionally relevant levels in cells containing an average of one pro-viral insert.

Multigenic lentiviral vectors for combined and tissue-specific expression of miRNA- and protein-based antiangiogenic factors

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Anne Louise Askou

Full Text Available Lentivirus-based gene delivery vectors carrying multiple gene cassettes are powerful tools in gene transfer studies and gene therapy, allowing coexpression of multiple therapeutic factors and, if desired, fluorescent reporters. Current strategies to express transgenes and microRNA (miRNA clusters from a single vector have certain limitations that affect transgene expression levels and/or vector titers. In this study, we describe a novel vector design that facilitates combined expression of therapeutic RNA- and protein-based antiangiogenic factors as well as a fluorescent reporter from back-to-back RNApolII-driven expression cassettes. This configuration allows effective production of intron-embedded miRNAs that are released upon transduction of target cells. Exploiting such multigenic lentiviral vectors, we demonstrate robust miRNA-directed downregulation of vascular endothelial growth factor (VEGF expression, leading to reduced angiogenesis, and parallel impairment of angiogenic pathways by codelivering the gene encoding pigment epithelium-derived factor (PEDF. Notably, subretinal injections of lentiviral vectors reveal efficient retinal pigment epithelium-specific gene expression driven by the VMD2 promoter, verifying that multigenic lentiviral vectors can be produced with high titers sufficient for in vivo applications. Altogether, our results suggest the potential applicability of combined miRNA- and protein-encoding lentiviral vectors in antiangiogenic gene therapy, including new combination therapies for amelioration of age-related macular degeneration.

Lentiviral Vector-Mediated GFP/fluc gene introduction into primary mouse NK cells

International Nuclear Information System (INIS)

L, Thi Thanh Hoa; Tae, Seong Ho; Min, Jung Joon

2007-01-01

NK cell is a type of lymphocyte that has ability in defense against virus infection and some kinds of cancer diseases. Recently, using genetic engineering, studies about the roles and functions of NK cells have been developing. In this study, we used lentivirus-based vector encoding GFP/Fluc gene to transfer into primary mouse NK cells. This model is a tool in studying characteristics of NK cells. The lentivirus used in this study was a commercial one, named LentiM1.3-Fluc, encoding GFP and Flue reporter genes under the control of the murine cytomegalovirus (MCMV) promoter. LentiM1.3-Fluc was infected into freshly isolated mouse NK cells at 2 20 MOl by incubating or using spin infection. In the spin infection, we gently suspended NK cells in viral fluid, then centrifuged at 2000 rpm, 20 minutes at room temperature and incubated for 1 day. After 1 day, virus was discarded and NK cells were cultured in IL-2 with or without IL-12 supplemented media. Infected NK cells were monitored by using fluorescent microscope for GFP and IVIS machine for Fire-fly luciferase expression. The results showed that using spin infection had much effect on introducing lentiviral vector-mediated reporter gene into NK cells than the way without spin. Also, NK cells which were cultured in IL-2 and IL-12 added media expressed higher fluorescent and luminescent signals than those cultured in only IL-2 supplemented media. When these NK cells were injected subcutaneously in Balb/C mice, the imaging signal was observed transiently. Our study demonstrates that by using a simple method, mouse NK cells can be transfected by lentivirus. And this will be useful in studying biology and therapeutic potential of NK cells. However, we require developing alternative lentiviral vectors with different promoter for in vivo application

Efficient transduction of equine adipose-derived mesenchymal stem cells by VSV-G pseudotyped lentiviral vectors.

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Petersen, Gayle F; Hilbert, Bryan; Trope, Gareth; Kalle, Wouter; Strappe, Padraig

2014-12-01

Equine adipose-derived mesenchymal stem cells (EADMSC) provide a unique cell-based approach for treatment of a variety of equine musculoskeletal injuries, via regeneration of diseased or damaged tissue, or the secretion of immunomodulatory molecules. These capabilities can be further enhanced by genetic modification using lentiviral vectors, which provide a safe and efficient method of gene delivery. We investigated the suitability of lentiviral vector technology for gene delivery into EADMSC, using GFP expressing lentiviral vectors pseudotyped with the G glycoprotein from the vesicular stomatitis virus (V-GFP) or, for the first time, the baculovirus gp64 envelope protein (G-GFP). In this study, we produced similarly high titre V-GFP and G-GFP lentiviral vectors. Flow cytometric analysis showed efficient transduction using V-GFP; however G-GFP exhibited a poor ability to transduce EADMSC. Transduction resulted in sustained GFP expression over four passages, with minimal effects on cell viability and doubling time, and an unaltered chondrogenic differentiation potential. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of Vector Backbone and Pseudotype on Lentiviral Vector-mediated Gene Transfer: Studies in Infant ADA-Deficient Mice and Rhesus Monkeys

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Carbonaro Sarracino, Denise; Tarantal, Alice F; Lee, C Chang I.; Martinez, Michele; Jin, Xiangyang; Wang, Xiaoyan; Hardee, Cinnamon L; Geiger, Sabine; Kahl, Christoph A; Kohn, Donald B

2014-01-01

Systemic delivery of a lentiviral vector carrying a therapeutic gene represents a new treatment for monogenic disease. Previously, we have shown that transfer of the adenosine deaminase (ADA) cDNA in vivo rescues the lethal phenotype and reconstitutes immune function in ADA-deficient mice. In order to translate this approach to ADA-deficient severe combined immune deficiency patients, neonatal ADA-deficient mice and newborn rhesus monkeys were treated with species-matched and mismatched vectors and pseudotypes. We compared gene delivery by the HIV-1-based vector to murine γ-retroviral vectors pseudotyped with vesicular stomatitis virus-glycoprotein or murine retroviral envelopes in ADA-deficient mice. The vesicular stomatitis virus-glycoprotein pseudotyped lentiviral vectors had the highest titer and resulted in the highest vector copy number in multiple tissues, particularly liver and lung. In monkeys, HIV-1 or simian immunodeficiency virus vectors resulted in similar biodistribution in most tissues including bone marrow, spleen, liver, and lung. Simian immunodeficiency virus pseudotyped with the gibbon ape leukemia virus envelope produced 10- to 30-fold lower titers than the vesicular stomatitis virus-glycoprotein pseudotype, but had a similar tissue biodistribution and similar copy number in blood cells. The relative copy numbers achieved in mice and monkeys were similar when adjusted to the administered dose per kg. These results suggest that this approach can be scaled-up to clinical levels for treatment of ADA-deficient severe combined immune deficiency subjects with suboptimal hematopoietic stem cell transplantation options. PMID:24925206

Effects of vector backbone and pseudotype on lentiviral vector-mediated gene transfer: studies in infant ADA-deficient mice and rhesus monkeys.

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Carbonaro Sarracino, Denise; Tarantal, Alice F; Lee, C Chang I; Martinez, Michele; Jin, Xiangyang; Wang, Xiaoyan; Hardee, Cinnamon L; Geiger, Sabine; Kahl, Christoph A; Kohn, Donald B

2014-10-01

Systemic delivery of a lentiviral vector carrying a therapeutic gene represents a new treatment for monogenic disease. Previously, we have shown that transfer of the adenosine deaminase (ADA) cDNA in vivo rescues the lethal phenotype and reconstitutes immune function in ADA-deficient mice. In order to translate this approach to ADA-deficient severe combined immune deficiency patients, neonatal ADA-deficient mice and newborn rhesus monkeys were treated with species-matched and mismatched vectors and pseudotypes. We compared gene delivery by the HIV-1-based vector to murine γ-retroviral vectors pseudotyped with vesicular stomatitis virus-glycoprotein or murine retroviral envelopes in ADA-deficient mice. The vesicular stomatitis virus-glycoprotein pseudotyped lentiviral vectors had the highest titer and resulted in the highest vector copy number in multiple tissues, particularly liver and lung. In monkeys, HIV-1 or simian immunodeficiency virus vectors resulted in similar biodistribution in most tissues including bone marrow, spleen, liver, and lung. Simian immunodeficiency virus pseudotyped with the gibbon ape leukemia virus envelope produced 10- to 30-fold lower titers than the vesicular stomatitis virus-glycoprotein pseudotype, but had a similar tissue biodistribution and similar copy number in blood cells. The relative copy numbers achieved in mice and monkeys were similar when adjusted to the administered dose per kg. These results suggest that this approach can be scaled-up to clinical levels for treatment of ADA-deficient severe combined immune deficiency subjects with suboptimal hematopoietic stem cell transplantation options.

Production of lentiviral vectors

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Otto-Wilhelm Merten

2016-01-01

Full Text Available Lentiviral vectors (LV have seen considerably increase in use as gene therapy vectors for the treatment of acquired and inherited diseases. This review presents the state of the art of the production of these vectors with particular emphasis on their large-scale production for clinical purposes. In contrast to oncoretroviral vectors, which are produced using stable producer cell lines, clinical-grade LV are in most of the cases produced by transient transfection of 293 or 293T cells grown in cell factories. However, more recent developments, also, tend to use hollow fiber reactor, suspension culture processes, and the implementation of stable producer cell lines. As is customary for the biotech industry, rather sophisticated downstream processing protocols have been established to remove any undesirable process-derived contaminant, such as plasmid or host cell DNA or host cell proteins. This review compares published large-scale production and purification processes of LV and presents their process performances. Furthermore, developments in the domain of stable cell lines and their way to the use of production vehicles of clinical material will be presented.

Prolonged liver-specific transgene expression by a non-primate lentiviral vector

International Nuclear Information System (INIS)

Condiotti, Reba; Curran, Michael A.; Nolan, Garry P.; Giladi, Hilla; Ketzinel-Gilad, Mali; Gross, Eitan; Galun, Eithan

2004-01-01

Liver-directed gene therapy has the potential for treatment of numerous inherited diseases affecting metabolic functions. The aim of this study was to evaluate gene expression in hepatocytes using feline immunodeficiency virus-based lentiviral vectors, which may be potentially safer than those based on human immunodeficiency virus. In vitro studies revealed that gene expression was stable for up to 24 days post-transduction and integration into the host cell genome was suggested by Alu PCR and Southern blot analyses. Systemic in vivo administration of viral particles by the hydrodynamics method resulted in high levels of gene expression exclusively in the liver for over 7 months whereas injection of plasmid DNA by the same method led to transient expression levels. Our studies suggest that feline immunodeficiency-based lentiviral vectors specifically transduce liver cells and may be used as a novel vehicle of gene delivery for treatment of metabolic disease

Neuron-specific RNA interference using lentiviral vectors

DEFF Research Database (Denmark)

Nielsen, Troels Tolstrup; Marion, Ingrid van; Hasholt, Lis

2009-01-01

BACKGROUND: Viral vectors have been used in several different settings for the delivery of small hairpin (sh) RNAs. However, most vectors have utilized ubiquitously-expressing polymerase (pol) III promoters to drive expression of the hairpin as a result of the strict requirement for precise...... transcriptional initiation and termination. Recently, pol II promoters have been used to construct vectors for RNA interference (RNAi). By embedding the shRNA into a micro RNA-context (miRNA) the endogenous miRNA processing machinery is exploited to achieve the mature synthetic miRNA (smiRNA), thereby expanding...... the possible promoter choices and eventually allowing cell type specific down-regulation of target genes. METHODS: In the present study, we constructed lentiviral vectors expressing smiRNAs under the control of pol II promoters to knockdown gene expression in cell culture and in the brain. RESULTS: We...

Lentiviral vectors in cancer immunotherapy.

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Oldham, Robyn Aa; Berinstein, Elliot M; Medin, Jeffrey A

2015-01-01

Basic science advances in cancer immunotherapy have resulted in various treatments that have recently shown success in the clinic. Many of these therapies require the insertion of genes into cells to directly kill them or to redirect the host's cells to induce potent immune responses. Other analogous therapies work by modifying effector cells for improved targeting and enhanced killing of tumor cells. Initial studies done using γ-retroviruses were promising, but safety concerns centered on the potential for insertional mutagenesis have highlighted the desire to develop other options for gene delivery. Lentiviral vectors (LVs) have been identified as potentially more effective and safer alternative delivery vehicles. LVs are now in use in clinical trials for many different types of inherited and acquired disorders, including cancer. This review will discuss current knowledge of LVs and the applications of this viral vector-based delivery vehicle to cancer immunotherapy.

Integrase-Deficient Lentiviral Vector as an All-in-One Platform for Highly Efficient CRISPR/Cas9-Mediated Gene Editing

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Pavel I. Ortinski

2017-06-01

Full Text Available The CRISPR/Cas9 systems have revolutionized the field of genome editing by providing unprecedented control over gene sequences and gene expression in many species, including humans. Lentiviral vectors (LVs are one of the primary delivery platforms for the CRISPR/Cas9 system due to their ability to accommodate large DNA payloads and sustain robust expression in a wide range of dividing and non-dividing cells. However, long-term expression of LV-delivered Cas9/guide RNA may lead to undesirable off-target effects characterized by non-specific RNA-DNA interactions and off-target DNA cleavages. Integrase-deficient lentiviral vectors (IDLVs present an attractive means for delivery of CRISPR/Cas9 components because: (1 they are capable of transducing a broad range of cells and tissues, (2 have superior packaging capacity compared to other vectors (e.g., adeno-associated viral vectors, and (3 they are expressed transiently and demonstrate very weak integration capability. In this manuscript, we aimed to establish IDLVs as a means for safe and efficient delivery of CRISPR/Cas9. To this end, we developed an all-in-one vector cassette with increased production efficacy and demonstrated that CRISPR/Cas9 delivered by the improved IDLV vectors can mediate rapid and robust gene editing in human embryonic kidney (HEK293T cells and post-mitotic brain neurons in vivo, via transient expression and with higher gene-targeting specificity than the corresponding integrase-competent vectors.

A guide to approaching regulatory considerations for lentiviral-mediated gene therapies.

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White, Michael; Whittaker, Roger; Stoll, Elizabeth Ann

2017-06-12

Lentiviral vectors are increasingly the gene transfer tool of choice for gene or cell therapies, with multiple clinical investigations showing promise for this viral vector in terms of both safety and efficacy. The third-generation vector system is well-characterized, effectively delivers genetic material and maintains long-term stable expression in target cells, delivers larger amounts of genetic material than other methods, is non-pathogenic and does not cause an inflammatory response in the recipient. This report aims to help academic scientists and regulatory managers negotiate the governance framework to achieve successful translation of a lentiviral vector-based gene therapy. The focus is on European regulations, and how they are administered in the United Kingdom, although many of the principles will be similar for other regions including the United States. The report justifies the rationale for using third-generation lentiviral vectors to achieve gene delivery for in vivo and ex vivo applications; briefly summarises the extant regulatory guidance for gene therapies, categorised as advanced therapeutic medicinal products (ATMPs); provides guidance on specific regulatory issues regarding gene therapies; presents an overview of the key stakeholders to be approached when pursuing clinical trials authorization for an ATMP; and includes a brief catalogue of the documentation required to submit an application for regulatory approval of a new gene therapy.

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...

Lentiviral vector mediated modification of mesenchymal stem cells & enhanced survival in an in vitro model of ischaemia.

LENUS (Irish Health Repository)

McGinley, Lisa

2012-01-31

INTRODUCTION: A combination of gene and cell therapies has the potential to significantly enhance the therapeutic value of mesenchymal stem cells (MSCs). The development of efficient gene delivery methods is essential if MSCs are to be of benefit using such an approach. Achieving high levels of transgene expression for the required period of time, without adversely affecting cell viability and differentiation capacity, is crucial. In the present study, we investigate lentiviral vector-mediated genetic modification of rat bone-marrow derived MSCs and examine any functional effect of such genetic modification in an in vitro model of ischaemia. METHODS: Transduction efficiency and transgene persistence of second and third generation rHIV-1 based lentiviral vectors were tested using reporter gene constructs. Use of the rHIV-pWPT-EF1-alpha-GFP-W vector was optimised in terms of dose, toxicity, cell species, and storage. The in vivo condition of ischaemia was modelled in vitro by separation into its associated constituent parts i.e. hypoxia, serum and glucose deprivation, in which the effect of therapeutic gene over-expression on MSC survival was investigated. RESULTS: The second generation lentiviral vector rHIV-pWPT-EF1-alpha-GFP-W, was the most efficient and provided the most durable transgene expression of the vectors tested. Transduction with this vector did not adversely affect MSC morphology, viability or differentiation potential, and transgene expression levels were unaffected by cryopreservation of transduced cells. Over-expression of HSP70 resulted in enhanced MSC survival and increased resistance to apoptosis in conditions of hypoxia and ischaemia. MSC differentiation capacity was significantly reduced after oxygen deprivation, but was preserved with HSP70 over-expression. CONCLUSIONS: Collectively, these data validate the use of lentiviral vectors for efficient in vitro gene delivery to MSCs and suggest that lentiviral vector transduction can facilitate

Lentiviral vector mediated modification of mesenchymal stem cells & enhanced survival in an in vitro model of ischaemia

LENUS (Irish Health Repository)

McGinley, Lisa

2011-03-07

Abstract Introduction A combination of gene and cell therapies has the potential to significantly enhance the therapeutic value of mesenchymal stem cells (MSCs). The development of efficient gene delivery methods is essential if MSCs are to be of benefit using such an approach. Achieving high levels of transgene expression for the required period of time, without adversely affecting cell viability and differentiation capacity, is crucial. In the present study, we investigate lentiviral vector-mediated genetic modification of rat bone-marrow derived MSCs and examine any functional effect of such genetic modification in an in vitro model of ischaemia. Methods Transduction efficiency and transgene persistence of second and third generation rHIV-1 based lentiviral vectors were tested using reporter gene constructs. Use of the rHIV-pWPT-EF1-α-GFP-W vector was optimised in terms of dose, toxicity, cell species, and storage. The in vivo condition of ischaemia was modelled in vitro by separation into its associated constituent parts i.e. hypoxia, serum and glucose deprivation, in which the effect of therapeutic gene over-expression on MSC survival was investigated. Results The second generation lentiviral vector rHIV-pWPT-EF1-α-GFP-W, was the most efficient and provided the most durable transgene expression of the vectors tested. Transduction with this vector did not adversely affect MSC morphology, viability or differentiation potential, and transgene expression levels were unaffected by cryopreservation of transduced cells. Over-expression of HSP70 resulted in enhanced MSC survival and increased resistance to apoptosis in conditions of hypoxia and ischaemia. MSC differentiation capacity was significantly reduced after oxygen deprivation, but was preserved with HSP70 over-expression. Conclusions Collectively, these data validate the use of lentiviral vectors for efficient in vitro gene delivery to MSCs and suggest that lentiviral vector transduction can facilitate

Construction of lentiviral shRNA expression vector targeting ...

African Journals Online (AJOL)

DNA oligo was cloned into lentiviral expression vector, and then polymerase chain reaction (PCR) and sequencing analyses were conducted to verify the constructs. The verified vectors were co-transfected into 293FT cells that could produce lentiviral. shRNA lentiviruses from the selected constructs were propagated and ...

The New Self-Inactivating Lentiviral Vector for Thalassemia Gene Therapy Combining Two HPFH Activating Elements Corrects Human Thalassemic Hematopoietic Stem Cells

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Papanikolaou, Eleni; Georgomanoli, Maria; Stamateris, Evangelos; Panetsos, Fottes; Karagiorga, Markisia; Tsaftaridis, Panagiotis; Graphakos, Stelios

2012-01-01

Abstract To address how low titer, variable expression, and gene silencing affect gene therapy vectors for hemoglobinopathies, in a previous study we successfully used the HPFH (hereditary persistence of fetal hemoglobin)-2 enhancer in a series of oncoretroviral vectors. On the basis of these data, we generated a novel insulated self-inactivating (SIN) lentiviral vector, termed GGHI, carrying the Aγ-globin gene with the −117 HPFH point mutation and the HPFH-2 enhancer and exhibiting a pancellular pattern of Aγ-globin gene expression in MEL-585 clones. To assess the eventual clinical feasibility of this vector, GGHI was tested on CD34+ hematopoietic stem cells from nonmobilized peripheral blood or bone marrow from 20 patients with β-thalassemia. Our results show that GGHI increased the production of γ-globin by 32.9% as measured by high-performance liquid chromatography (p=0.001), with a mean vector copy number per cell of 1.1 and a mean transduction efficiency of 40.3%. Transduced populations also exhibited a lower rate of apoptosis and resulted in improvement of erythropoiesis with a higher percentage of orthochromatic erythroblasts. This is the first report of a locus control region (LCR)-free SIN insulated lentiviral vector that can be used to efficiently produce the anticipated therapeutic levels of γ-globin protein in the erythroid progeny of primary human thalassemic hematopoietic stem cells in vitro. PMID:21875313

Lentiviral hematopoietic cell gene therapy for X-linked adrenoleukodystrophy.

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Cartier, Nathalie; Hacein-Bey-Abina, Salima; Bartholomae, Cynthia C; Bougnères, Pierre; Schmidt, Manfred; Kalle, Christof Von; Fischer, Alain; Cavazzana-Calvo, Marina; Aubourg, Patrick

2012-01-01

X-linked adrenoleukodystrophy (X-ALD) is a severe genetic demyelinating disease caused by a deficiency in ALD protein, an adenosine triphosphate-binding cassette transporter encoded by the ABCD1 gene. When performed at an early stage of the disease, allogeneic hematopoietic stem cell transplantation (HCT) can arrest the progression of cerebral demyelinating lesions. To overcome the limitations of allogeneic HCT, hematopoietic stem cell (HSC) gene therapy strategy aiming to perform autologous transplantation of lentivirally corrected cells was developed. We demonstrated the preclinical feasibility of HSC gene therapy for ALD based on the correction of CD34+ cells from X-ALD patients using an HIV1-derived lentiviral vector. These results prompted us to initiate an HSC gene therapy trial in two X-ALD patients who had developed progressive cerebral demyelination, were candidates for allogeneic HCT, but had no HLA-matched donors or cord blood. Autologous CD34+ cells were purified from the peripheral blood after G-CSF stimulation, genetically corrected ex vivo with a lentiviral vector encoding wild-type ABCD1 cDNA, and then reinfused into the patients after they had received full myeloablative conditioning. Over 3 years of follow-up, the hematopoiesis remained polyclonal in the two patients treated with 7-14% of granulocytes, monocytes, and T and B lymphocytes expressing the lentivirally encoded ALD protein. There was no evidence of clonal dominance or skewing based on the retrieval of lentiviral insertion repertoire in different hematopoietic lineages by deep sequencing. Cerebral demyelination was arrested 14 and 16months, respectively, in the two treated patients, without further progression up to the last follow-up, a clinical outcome that is comparable to that observed after allogeneic HCT. Longer follow-up of these two treated patients and HSC gene therapy performed in additional ALD patients are however needed to evaluate the safety and efficacy of lentiviral HSC

UMG Lenti: novel lentiviral vectors for efficient transgene- and reporter gene expression in human early hematopoietic progenitors.

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Emanuela Chiarella

Full Text Available Lentiviral vectors are widely used to investigate the biological properties of regulatory proteins and/or of leukaemia-associated oncogenes by stably enforcing their expression in hematopoietic stem and progenitor cells. In these studies it is critical to be able to monitor and/or sort the infected cells, typically via fluorescent proteins encoded by the modified viral genome. The most popular strategy to ensure co-expression of transgene and reporter gene is to insert between these cDNAs an IRES element, thus generating bi-cistronic mRNAs whose transcription is driven by a single promoter. However, while the product of the gene located upstream of the IRES is generally abundantly expressed, the translation of the downstream cDNA (typically encoding the reporter protein is often inconsistent, which hinders the detection and the isolation of transduced cells. To overcome these limitations, we developed novel lentiviral dual-promoter vectors (named UMG-LV5 and -LV6 where transgene expression is driven by the potent UBC promoter and that of the reporter protein, EGFP, by the minimal regulatory element of the WASP gene. These vectors, harboring two distinct transgenes, were tested in a variety of human haematopoietic cell lines as well as in primary human CD34+ cells in comparison with the FUIGW vector that contains the expression cassette UBC-transgene-IRES-EGFP. In these experiments both UMG-LV5 and UMG-LV6 yielded moderately lower transgene expression than FUIGW, but dramatically higher levels of EGFP, thereby allowing the easy distinction between transduced and non-transduced cells. An additional construct was produced, in which the cDNA encoding the reporter protein is upstream, and the transgene downstream of the IRES sequence. This vector, named UMG-LV11, proved able to promote abundant expression of both transgene product and EGFP in all cells tested. The UMG-LVs represent therefore useful vectors for gene transfer-based studies in

UMG Lenti: novel lentiviral vectors for efficient transgene- and reporter gene expression in human early hematopoietic progenitors.

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Chiarella, Emanuela; Carrà, Giovanna; Scicchitano, Stefania; Codispoti, Bruna; Mega, Tiziana; Lupia, Michela; Pelaggi, Daniela; Marafioti, Maria G; Aloisio, Annamaria; Giordano, Marco; Nappo, Giovanna; Spoleti, Cristina B; Grillone, Teresa; Giovannone, Emilia D; Spina, Raffaella; Bernaudo, Francesca; Moore, Malcolm A S; Bond, Heather M; Mesuraca, Maria; Morrone, Giovanni

2014-01-01

Lentiviral vectors are widely used to investigate the biological properties of regulatory proteins and/or of leukaemia-associated oncogenes by stably enforcing their expression in hematopoietic stem and progenitor cells. In these studies it is critical to be able to monitor and/or sort the infected cells, typically via fluorescent proteins encoded by the modified viral genome. The most popular strategy to ensure co-expression of transgene and reporter gene is to insert between these cDNAs an IRES element, thus generating bi-cistronic mRNAs whose transcription is driven by a single promoter. However, while the product of the gene located upstream of the IRES is generally abundantly expressed, the translation of the downstream cDNA (typically encoding the reporter protein) is often inconsistent, which hinders the detection and the isolation of transduced cells. To overcome these limitations, we developed novel lentiviral dual-promoter vectors (named UMG-LV5 and -LV6) where transgene expression is driven by the potent UBC promoter and that of the reporter protein, EGFP, by the minimal regulatory element of the WASP gene. These vectors, harboring two distinct transgenes, were tested in a variety of human haematopoietic cell lines as well as in primary human CD34+ cells in comparison with the FUIGW vector that contains the expression cassette UBC-transgene-IRES-EGFP. In these experiments both UMG-LV5 and UMG-LV6 yielded moderately lower transgene expression than FUIGW, but dramatically higher levels of EGFP, thereby allowing the easy distinction between transduced and non-transduced cells. An additional construct was produced, in which the cDNA encoding the reporter protein is upstream, and the transgene downstream of the IRES sequence. This vector, named UMG-LV11, proved able to promote abundant expression of both transgene product and EGFP in all cells tested. The UMG-LVs represent therefore useful vectors for gene transfer-based studies in hematopoietic stem and

[Construction of recombinant lentiviral vector of Tie2-RNAi and its influence on malignant melanoma cells in vitro].

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Shan, Xiu-ying; Liu, Zhao-liang; Wang, Biao; Guo, Guo-xiang; Wang, Mei-shui; Zhuang, Fu-lian; Cai, Chuan-shu; Zhang, Ming-feng; Zhang, Yan-ding

2011-07-01

To construct lentivector carrying Tie2-Small interfering RNA (SiRNA), so as to study its influence on malignant melanoma cells. Recombinant plasmid pSilencer 1.0-U6-Tie2-siRNA and plasmid pNL-EGFP were digested with XbaI, ligated a target lentiviral transfer plasmid of pNL-EGFP-U6-Tie2-I or pNL-EGFP-U6-Tie2-II, and then the electrophoresis clones was sequenced. Plasmids of pNL-EGFP-U6-Tie2-I and pNL-EGFP-U6-Tie2-II were constructed and combined with pVSVG and pHelper, respectively, to constitute lentiviral vector system of three plasmids. The Lentiviral vector system was transfected into 293T cell to produce pNL-EGFP-U6-Tie2- I and pNL-EGFP-U6-Tie2-II lentivirus. Then the supernatant was collected to determine the titer. Malignant melanoma cells were infected by both lentiviruses and identified by Realtime RT-PCR to assess inhibitory efficiency. The recombinant lentiviral vectors of Tie2-RNAi were constructed successfully which were analyzed with restriction enzyme digestion and identified by sequencing. And the titer of lentiviral vector was 8.8 x 10(3)/ml, which was determined by 293T cell. The results of Realtime RT-PCR demonstrated that the lentiviral vectors of Tie2-RNAi could infect malignant melanoma cells and inhibit the expression of Tie2 genes in malignant melanoma cells (P0.05) between the two lentiviral vectors of Tie2-RNAi. Lentivector carrying Tie2-SiRNA can be constructed successfully and inhibit the expression of Tie2 gene in vitro significantly. The study will supply the theory basis for the further research on the inhibition of tumor growth in vivo.

Transduction of liver cells by lentiviral vectors: analysis in living animals by fluorescence imaging

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Pfeifer, A.; Kessler, T.; Yang, M.; Baranov, E.; Kootstra, N.; Cheresh, D. A.; Hoffman, R. M.; Verma, I. M.

2001-01-01

Viral vectors based on lentiviruses, such as the human immunodeficiency virus, are able to transduce a broad spectrum of nondividing cells in vivo. This ability of lentiviral vectors makes them an attractive vehicle for gene transfer into the liver. In order to determine the requirements for

Highly efficient retrograde gene transfer into motor neurons by a lentiviral vector pseudotyped with fusion glycoprotein.

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Miyabi Hirano

Full Text Available The development of gene therapy techniques to introduce transgenes that promote neuronal survival and protection provides effective therapeutic approaches for neurological and neurodegenerative diseases. Intramuscular injection of adenoviral and adeno-associated viral vectors, as well as lentiviral vectors pseudotyped with rabies virus glycoprotein (RV-G, permits gene delivery into motor neurons in animal models for motor neuron diseases. Recently, we developed a vector with highly efficient retrograde gene transfer (HiRet by pseudotyping a human immunodeficiency virus type 1 (HIV-1-based vector with fusion glycoprotein B type (FuG-B or a variant of FuG-B (FuG-B2, in which the cytoplasmic domain of RV-G was replaced by the corresponding part of vesicular stomatitis virus glycoprotein (VSV-G. We have also developed another vector showing neuron-specific retrograde gene transfer (NeuRet with fusion glycoprotein C type, in which the short C-terminal segment of the extracellular domain and transmembrane/cytoplasmic domains of RV-G was substituted with the corresponding regions of VSV-G. These two vectors afford the high efficiency of retrograde gene transfer into different neuronal populations in the brain. Here we investigated the efficiency of the HiRet (with FuG-B2 and NeuRet vectors for retrograde gene transfer into motor neurons in the spinal cord and hindbrain in mice after intramuscular injection and compared it with the efficiency of the RV-G pseudotype of the HIV-1-based vector. The main highlight of our results is that the HiRet vector shows the most efficient retrograde gene transfer into both spinal cord and hindbrain motor neurons, offering its promising use as a gene therapeutic approach for the treatment of motor neuron diseases.

Design of a titering assay for lentiviral vectors utilizing direct extraction of DNA from transduced cells in microtiter plates

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Michele E Murphy

2016-01-01

Full Text Available Using lentiviral vector products in clinical applications requires an accurate method for measuring transduction titer. For vectors lacking a marker gene, quantitative polymerase chain reaction is used to evaluate the number of vector DNA copies in transduced target cells, from which a transduction titer is calculated. Immune Design previously described an integration-deficient lentiviral vector pseudotyped with a modified Sindbis virus envelope for use in cancer immunotherapy (VP02, of the ZVex platform. Standard protocols for titering integration-competent lentiviral vectors employ commercial spin columns to purify vector DNA from transduced cells, but such columns are not optimized for isolation of extrachromosomal (nonintegrated DNA. Here, we describe a 96-well transduction titer assay in which DNA extraction is performed in situ in the transduction plate, yielding quantitative recovery of extrachromosomal DNA. Vector titers measured by this method were higher than when commercial spin columns were used for DNA isolation. Evaluation of the method's specificity, linear range, and precision demonstrate that it is suitable for use as a lot release assay to support clinical trials with VP02. Finally, the method is compatible with titering both integrating and nonintegrating lentiviral vectors, suggesting that it may be used to evaluate the transduction titer for any lentiviral vector.

Generation of a lentiviral vector producer cell clone for human Wiskott-Aldrich syndrome gene therapy

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Matthew M Wielgosz

Full Text Available We have developed a producer cell line that generates lentiviral vector particles of high titer. The vector encodes the Wiskott-Aldrich syndrome (WAS protein. An insulator element has been added to the long terminal repeats of the integrated vector to limit proto-oncogene activation. The vector provides high-level, stable expression of WAS protein in transduced murine and human hematopoietic cells. We have also developed a monoclonal antibody specific for intracellular WAS protein. This antibody has been used to monitor expression in blood and bone marrow cells after transfer into lineage negative bone marrow cells from WAS mice and in a WAS negative human B-cell line. Persistent expression of the transgene has been observed in transduced murine cells 12–20 weeks following transplantation. The producer cell line and the specific monoclonal antibody will facilitate the development of a clinical protocol for gene transfer into WAS protein deficient stem cells.

Tracking differentiating neural progenitors in pluripotent cultures using microRNA-regulated lentiviral vectors.

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Sachdeva, Rohit; Jönsson, Marie E; Nelander, Jenny; Kirkeby, Agnete; Guibentif, Carolina; Gentner, Bernhard; Naldini, Luigi; Björklund, Anders; Parmar, Malin; Jakobsson, Johan

2010-06-22

In this study, we have used a microRNA-regulated lentiviral reporter system to visualize and segregate differentiating neuronal cells in pluripotent cultures. Efficient suppression of transgene expression, specifically in undifferentiated pluripotent cells, was achieved by using a lentiviral vector expressing a fluorescent reporter gene regulated by microRNA-292. Using this strategy, it was possible to track progeny from murine ES, human ES cells, and induced pluripotent stem cells as they differentiated toward the neural lineage. In addition, this strategy was successfully used to FACS purify neuronal progenitors for molecular analysis and transplantation. FACS enrichment reduced tumor formation and increased survival of ES cell-derived neuronal progenitors after transplantation. The properties and versatility of the microRNA-regulated vectors allows broad use of these vectors in stem cell applications.

Lentiviral Vector Mediated Claudin1 Silencing Inhibits Epithelial to Mesenchymal Transition in Breast Cancer Cells

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Xianqi Zhao

2015-06-01

Full Text Available Breast cancer has a high incidence and mortality rate worldwide. Several viral vectors including lentiviral, adenoviral and adeno-associated viral vectors have been used in gene therapy for various forms of human cancer, and have shown promising effects in controlling tumor development. Claudin1 (CLDN1 is a member of the tetraspan transmembrane protein family that plays a major role in tight junctions and is associated with tumor metastasis. However, the role of CLDN1 in breast cancer is largely unexplored. In this study, we tested the therapeutic potential of silencing CLDN1 expression in two breast cancer (MDA-MB-231 and MCF7 cell lines using lentiviral vector mediated RNA interference. We found that a CLDN1 short hairpin (shRNA construct efficiently silenced CLDN1 expression in both breast cancer cell lines, and CLDN1 knockdown resulted in reduced cell proliferation, survival, migration and invasion. Furthermore, silencing CLDN1 inhibited epithelial to mesenchymal transition (EMT by upregulating the epithelial cell marker, E-cadherin, and downregulating mesenchymal markers, smooth muscle cell alpha-actin (SMA and Snai2. Our data demonstrated that lentiviral vector mediated CLDN1 RNA interference has great potential in breast cancer gene therapy by inhibiting EMT and controlling tumor cell growth.

Gene transfer to chicks using lentiviral vectors administered via the embryonic chorioallantoic membrane.

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Gideon Hen

Full Text Available The lack of affordable techniques for gene transfer in birds has inhibited the advancement of molecular studies in avian species. Here we demonstrate a new approach for introducing genes into chicken somatic tissues by administration of a lentiviral vector, derived from the feline immunodeficiency virus (FIV, into the chorioallantoic membrane (CAM of chick embryos on embryonic day 11. The FIV-derived vectors carried yellow fluorescent protein (YFP or recombinant alpha-melanocyte-stimulating hormone (α-MSH genes, driven by the cytomegalovirus (CMV promoter. Transgene expression, detected in chicks 2 days after hatch by quantitative real-time PCR, was mostly observed in the liver and spleen. Lower expression levels were also detected in the brain, kidney, heart and breast muscle. Immunofluorescence and flow cytometry analyses confirmed transgene expression in chick tissues at the protein level, demonstrating a transduction efficiency of ∼0.46% of liver cells. Integration of the viral vector into the chicken genome was demonstrated using genomic repetitive (CR1-PCR amplification. Viability and stability of the transduced cells was confirmed using terminal deoxynucleotidyl transferase (dUTP nick end labeling (TUNEL assay, immunostaining with anti-proliferating cell nuclear antigen (anti-PCNA, and detection of transgene expression 51 days post transduction. Our approach led to only 9% drop in hatching efficiency compared to non-injected embryos, and all of the hatched chicks expressed the transgenes. We suggest that the transduction efficiency of FIV vectors combined with the accessibility of the CAM vasculature as a delivery route comprise a new powerful and practical approach for gene delivery into somatic tissues of chickens. Most relevant is the efficient transduction of the liver, which specializes in the production and secretion of proteins, thereby providing an optimal target for prolonged study of secreted hormones and peptides.

Safe and Effective Gene Therapy for Murine Wiskott-Aldrich Syndrome Using an Insulated Lentiviral Vector

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Swati Singh

2017-03-01

Full Text Available Wiskott-Aldrich syndrome (WAS is a life-threatening immunodeficiency caused by mutations within the WAS gene. Viral gene therapy to restore WAS protein (WASp expression in hematopoietic cells of patients with WAS has the potential to improve outcomes relative to the current standard of care, allogeneic bone marrow transplantation. However, the development of viral vectors that are both safe and effective has been problematic. While use of viral transcriptional promoters may increase the risk of insertional mutagenesis, cellular promoters may not achieve WASp expression levels necessary for optimal therapeutic effect. Here we evaluate a self-inactivating (SIN lentiviral vector combining a chromatin insulator upstream of a viral MND (MPSV LTR, NCR deleted, dl587 PBS promoter driving WASp expression. Used as a gene therapeutic in Was−/− mice, this vector resulted in stable WASp+ cells in all hematopoietic lineages and rescue of T and B cell defects with a low number of viral integrations per cell, without evidence of insertional mutagenesis in serial bone marrow transplants. In a gene transfer experiment in non-human primates, the insulated MND promoter (driving GFP expression demonstrated long-term polyclonal engraftment of GFP+ cells. These observations demonstrate that the insulated MND promoter safely and efficiently reconstitutes clinically effective WASp expression and should be considered for future WAS therapy.

Robust Lentiviral Gene Delivery But Limited Transduction Capacity of Commonly Used Adeno-Associated Viral Serotypes in Xenotransplanted Human Skin.

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Jakobsen, Maria; Askou, Anne Louise; Stenderup, Karin; Rosada, Cecilia; Dagnæs-Hansen, Frederik; Jensen, Thomas G; Corydon, Thomas J; Mikkelsen, Jacob Giehm; Aagaard, Lars

2015-08-01

Skin is an easily accessible organ, and therapeutic gene transfer to skin remains an attractive alternative for the treatment of skin diseases. Although we have previously documented potent lentiviral gene delivery to human skin, vectors based on adeno-associated virus (AAV) rank among the most promising gene delivery tools for in vivo purposes. Thus, we compared the potential usefulness of various serotypes of recombinant AAV vectors and lentiviral vectors for gene transfer to human skin in a xenotransplanted mouse model. Vector constructs encoding firefly luciferase were packaged in AAV capsids of serotype 1, 2, 5, 6, 8, and 9 and separately administered by intradermal injection in human skin transplants. For all serotypes, live bioimaging demonstrated low levels of transgene expression in the human skin graft, and firefly luciferase expression was observed primarily in neighboring tissue outside of the graft. In contrast, gene delivery by intradermally injected lentiviral vectors was efficient and led to extensive and persistent firefly luciferase expression within the human skin graft only. The study demonstrates the limited capacity of single-stranded AAV vectors of six commonly used serotypes for gene delivery to human skin in vivo.

Ethical considerations in the use of lentiviral vectors for genetic transfer.

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Roy, I

2001-11-01

This chapter will outline the various concerns which have been raised in scientific, bioethics, and lay communities about the use of lentiviral vectors for purposes of gene therapy. Many of these concerns are ranged around gene therapy itself; others are concerns particular to using this sort of vector for genetic modification of human cells. These concerns are outlined within the chapter, and arguments are given in favor and against various approaches to these concerns. Lastly, it is noted throughout that at this stage of research into gene therapy, the most practical approach to these dilemmas is to maintain awareness of the ethical problems and provide information to those concerned with all aspects of the development of this set of technologies.

[Construction of the lentiviral expression vector for anti-p185(erbB2) mouse/human chimeric antibody].

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Liu, Fang; Li, Li; Zhang, Wei; Wang, Qi

2013-04-01

This research was to construct the lentiviral expression vector for anti- p185(erbB2) mouse/human chimeric antibody and to determine the expression of the chimeric antibody gene in 293T cells transfected with this vector. The genes (vL and vH) coding light and heavy chain of variable regions of anti-p185(erbB2) mAb and the constant regions of human IgG1 (kappa and gamma1) were cloned with PCR method. The target genes were assembled by three-primers PCR method to obtain the chimeric light chain (L) and the chimeric heavy chain (H). Both chains inserted into the down stream and upper stream of IRES gene of the plasmid pVAX1/IRES respectively. We digested the plasmid pVAX1/ H-IRES-L with endoenzyme and subcloned H-IRES-L into the lentiviral vector pWPI. The enzyme digestion and sequence analysis showed that the lentiviral expression vector pWPI/H-IRES-L was constructed correctly. Then, it was transfected into 293T cells and after 48h, GFP protein expression in 293T cells were detected by fluorescent microscope and the chimeric antibody expression was detected by RT-PCR and direct ELISA. The results showed that after 293T cells were transfected with recombination plasmid, both light and heavy chains of the chimeric antibody genes could express together. The chimeric antibody expressed could bind to p185(erbB2) specifically. This research may lay a sound foundation for further study of anti-p185(erbB2) engineered antibody.

Large-scale manufacture and characterization of a lentiviral vector produced for clinical ex vivo gene therapy application.

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Merten, Otto-Wilhelm; Charrier, Sabine; Laroudie, Nicolas; Fauchille, Sylvain; Dugué, Céline; Jenny, Christine; Audit, Muriel; Zanta-Boussif, Maria-Antonietta; Chautard, Hélène; Radrizzani, Marina; Vallanti, Giuliana; Naldini, Luigi; Noguiez-Hellin, Patricia; Galy, Anne

2011-03-01

From the perspective of a pilot clinical gene therapy trial for Wiskott-Aldrich syndrome (WAS), we implemented a process to produce a lentiviral vector under good manufacturing practices (GMP). The process is based on the transient transfection of 293T cells in Cell Factory stacks, scaled up to harvest 50 liters of viral stock per batch, followed by purification of the vesicular stomatitis virus glycoprotein-pseudotyped particles through several membrane-based and chromatographic steps. The process leads to a 200-fold volume concentration and an approximately 3-log reduction in protein and DNA contaminants. An average yield of 13% of infectious particles was obtained in six full-scale preparations. The final product contained low levels of contaminants such as simian virus 40 large T antigen or E1A sequences originating from producer cells. Titers as high as 2 × 10(9) infectious particles per milliliter were obtained, generating up to 6 × 10(11) infectious particles per batch. The purified WAS vector was biologically active, efficiently expressing the genetic insert in WAS protein-deficient B cell lines and transducing CD34(+) cells. The vector introduced 0.3-1 vector copy per cell on average in CD34(+) cells when used at the concentration of 10(8) infectious particles per milliliter, which is comparable to preclinical preparations. There was no evidence of cellular toxicity. These results show the implementation of large-scale GMP production, purification, and control of advanced HIV-1-derived lentiviral technology. Results obtained with the WAS vector provide the initial manufacturing and quality control benchmarking that should be helpful to further development and clinical applications.

Lentiviral gene ontology (LeGO) vectors equipped with novel drug-selectable fluorescent proteins: new building blocks for cell marking and multi-gene analysis.

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Weber, K; Mock, U; Petrowitz, B; Bartsch, U; Fehse, B

2010-04-01

Vector-encoded fluorescent proteins (FPs) facilitate unambiguous identification or sorting of gene-modified cells by fluorescence-activated cell sorting (FACS). Exploiting this feature, we have recently developed lentiviral gene ontology (LeGO) vectors (www.LentiGO-Vectors.de) for multi-gene analysis in different target cells. In this study, we extend the LeGO principle by introducing 10 different drug-selectable FPs created by fusing one of the five selection marker (protecting against blasticidin, hygromycin, neomycin, puromycin and zeocin) and one of the five FP genes (Cerulean, eGFP, Venus, dTomato and mCherry). All tested fusion proteins allowed both fluorescence-mediated detection and drug-mediated selection of LeGO-transduced cells. Newly generated codon-optimized hygromycin- and neomycin-resistance genes showed improved expression as compared with their ancestors. New LeGO constructs were produced at titers >10(6) per ml (for non-concentrated supernatants). We show efficient combinatorial marking and selection of various cells, including mesenchymal stem cells, simultaneously transduced with different LeGO constructs. Inclusion of the cytomegalovirus early enhancer/chicken beta-actin promoter into LeGO vectors facilitated robust transgene expression in and selection of neural stem cells and their differentiated progeny. We suppose that the new drug-selectable markers combining advantages of FACS and drug selection are well suited for numerous applications and vector systems. Their inclusion into LeGO vectors opens new possibilities for (stem) cell tracking and functional multi-gene analysis.

CCR5 Gene Disruption via Lentiviral Vectors Expressing Cas9 and Single Guided RNA Renders Cells Resistant to HIV-1 Infection

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Liu, Jingjing; Zhang, Di; Kimata, Jason T.; Zhou, Paul

2014-01-01

CCR5, a coreceptor for HIV-1 entry, is a major target for drug and genetic intervention against HIV-1. Genetic intervention strategies have knocked down CCR5 expression levels by shRNA or disrupted the CCR5 gene using zinc finger nucleases (ZFN) or Transcription activator-like effector nuclease (TALEN). In the present study, we silenced CCR5 via CRISPR associated protein 9 (Cas9) and single guided RNAs (sgRNAs). We constructed lentiviral vectors expressing Cas9 and CCR5 sgRNAs. We show that a single round transduction of lentiviral vectors expressing Cas9 and CCR5 sgRNAs into HIV-1 susceptible human CD4+ cells yields high frequencies of CCR5 gene disruption. CCR5 gene-disrupted cells are not only resistant to R5-tropic HIV-1, including transmitted/founder (T/F) HIV-1 isolates, but also have selective advantage over CCR5 gene-undisrupted cells during R5-tropic HIV-1 infection. Importantly, using T7 endonuclease I assay we did not detect genome mutations at potential off-target sites that are highly homologous to these CCR5 sgRNAs in stably transduced cells even at 84 days post transduction. Thus we conclude that silencing of CCR5 via Cas9 and CCR5-specific sgRNAs could be a viable alternative strategy for engineering resistance against HIV-1. PMID:25541967

A rapid and efficient branched DNA hybridization assay to titer lentiviral vectors.

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Nair, Ayyappan; Xie, Jinger; Joshi, Sarasijam; Harden, Paul; Davies, Joan; Hermiston, Terry

2008-11-01

A robust assay to titer lentiviral vectors is imperative to qualifying their use in drug discovery, target validation and clinical applications. In this study, a novel branched DNA based hybridization assay was developed to titer lentiviral vectors by quantifying viral RNA genome copy numbers from viral lysates without having to purify viral RNA, and this approach was compared with other non-functional (p24 protein ELISA and viral RT-qPCR) and a functional method (reporter gene expression) used commonly. The RT-qPCR method requires purification of viral RNA and the accuracy of titration therefore depends on the efficiency of purification; this requirement is ameliorated in the hybridization assay as RNA is measured directly in viral lysates. The present study indicates that the hybridization based titration assay performed on viral lysates was more accurate and has additional advantages of being rapid, robust and not dependent on transduction efficiency in different cell types.

Lentiviral vector-mediated genetic modification of human neural progenitor cells for ex vivo gene therapy.

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Capowski, Elizabeth E; Schneider, Bernard L; Ebert, Allison D; Seehus, Corey R; Szulc, Jolanta; Zufferey, Romain; Aebischer, Patrick; Svendsen, Clive N

2007-07-30

Human neural progenitor cells (hNPC) hold great potential as an ex vivo system for delivery of therapeutic proteins to the central nervous system. When cultured as aggregates, termed neurospheres, hNPC are capable of significant in vitro expansion. In the current study, we present a robust method for lentiviral vector-mediated gene delivery into hNPC that maintains the differentiation and proliferative properties of neurosphere cultures while minimizing the amount of viral vector used and controlling the number of insertion sites per population. This method results in long-term, stable expression even after differentiation of the hNPC to neurons and astrocytes and allows for generation of equivalent transgenic populations of hNPC. In addition, the in vitro analysis presented predicts the behavior of transgenic lines in vivo when transplanted into a rodent model of Parkinson's disease. The methods presented provide a powerful tool for assessing the impact of factors such as promoter systems or different transgenes on the therapeutic utility of these cells.

HIV-1 resistance conferred by siRNA cosuppression of CXCR4 and CCR5 coreceptors by a bispecific lentiviral vector

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Akkina Ramesh

2005-01-01

Full Text Available Abstract Background RNA interference (RNAi mediated by small interfering RNAs (siRNAs has proved to be a highly effective gene silencing mechanism with great potential for HIV/AIDS gene therapy. Previous work with siRNAs against cellular coreceptors CXCR4 and CCR5 had shown that down regulation of these surface molecules could prevent HIV-1 entry and confer viral resistance. Since monospecific siRNAs targeting individual coreceptors are inadequate in protecting against both T cell tropic (X4 and monocyte tropic (R5 viral strains simultaneously, bispecific constructs with dual specificity are required. For effective long range therapy, the bispecific constructs need to be stably transduced into HIV-1 target cells via integrating viral vectors. Results To achieve this goal, lentiviral vectors incorporating both CXCR4 and CCR5 siRNAs of short hairpin design were constructed. The CXCR4 siRNA was driven by a U6 promoter whereas the CCR5 siRNA was driven by an H1 promoter. A CMV promoter driven EGFP reporter gene is also incorporated in the bispecific construct. High efficiency transduction into coreceptor expressing Magi and Ghost cell lines with a concomitant down regulation of respective coreceptors was achieved with lentiviral vectors. When the siRNA expressing transduced cells were challenged with X4 and R5 tropic HIV-1, they demonstrated marked viral resistance. HIV-1 resistance was also observed in bispecific lentiviral vector transduced primary PBMCs. Conclusions Both CXCR4 and CCR5 coreceptors could be simultaneously targeted for down regulation by a single combinatorial lentiviral vector incorporating respective anti-coreceptor siRNAs. Stable down regulation of both the coreceptors protects cells against infection by both X4 and R5 tropic HIV-1. Stable down regulation of cellular molecules that aid in HIV-1 infection will be an effective strategy for long range HIV gene therapy.

Lentiviral Delivery of Proteins for Genome Engineering.

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Cai, Yujia; Mikkelsen, Jacob Giehm

2016-01-01

Viruses have evolved to traverse cellular barriers and travel to the nucleus by mechanisms that involve active transport through the cytoplasm and viral quirks to resist cellular restriction factors and innate immune responses. Virus-derived vector systems exploit the capacity of viruses to ferry genetic information into cells, and now - more than three decades after the discovery of HIV - lentiviral vectors based on HIV-1 have become instrumental in biomedical research and gene therapies that require genomic insertion of transgenes. By now, the efficacy of lentiviral gene delivery to stem cells, cells of the immune system including T cells, hepatic cells, and many other therapeutically relevant cell types is well established. Along with nucleic acids, HIV-1 virions carry the enzymatic tools that are essential for early steps of infection. Such capacity to package enzymes, even proteins of nonviral origin, has unveiled new ways of exploiting cellular intrusion of HIV-1. Based on early findings demonstrating the packaging of heterologous proteins into virus particles as part of the Gag and GagPol polypeptides, we have established lentiviral protein transduction for delivery of DNA transposases and designer nucleases. This strategy for delivering genome-engineering proteins facilitates high enzymatic activity within a short time frame and may potentially improve the safety of genome editing. Exploiting the full potential of lentiviral vectors, incorporation of foreign protein can be combined with the delivery of DNA transposons or a donor sequence for homology-directed repair in so-called 'all-in-one' lentiviral vectors. Here, we briefly describe intracellular restrictions that may affect lentiviral gene and protein delivery and review the current status of lentiviral particles as carriers of tool kits for genome engineering.

Characteristics of lentiviral vectors harboring the proximal promoter of the vav proto-oncogene: a weak and efficient promoter for gene therapy.

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Almarza, Elena; Río, Paula; Meza, Nestor W; Aldea, Montserrat; Agirre, Xabier; Guenechea, Guillermo; Segovia, José C; Bueren, Juan A

2007-08-01

Recent published data have shown the efficacy of gene therapy treatments of certain monogenic diseases. Risks of insertional oncogenesis, however, indicate the necessity of developing new vectors with weaker or cell-restricted promoters to minimize the trans-activation activity of integrated proviruses. We have inserted the proximal promoter of the vav proto-oncogene into self-inactivating lentiviral vectors (vav-LVs) and investigated the expression pattern and therapeutic efficacy of these vectors. Compared with other LVs frequently used in gene therapy, vav-LVs mediated a weak, though homogeneous and stable, expression in in vitro-cultured cells. Transplantation experiments using transduced mouse bone marrow and human CD34(+) cells confirmed the stable activity of the promoter in vivo. To investigate whether the weak activity of this promoter was compatible with a therapeutic effect, a LV expressing the Fanconi anemia A (FANCA) gene was constructed (vav-FANCA LV). Although this vector induced a low expression of FANCA, compared to the expression induced by a LV harboring the spleen focus-forming virus (SFFV) promoter, the two vectors corrected the phenotype of cells from a patient with FA-A with the same efficacy. We propose that self-inactivating vectors harboring weak promoters, such as the vav promoter, will improve the safety of gene therapy and will be of particular interest for the treatment of diseases where a high expression of the transgene is not required.

Lentiviral-Mediated Gene Therapy in Fanconi Anemia-A Mice Reveals Long-Term Engraftment and Continuous Turnover of Corrected HSCs.

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Molina-Estevez, F Javier; Nowrouzi, Ali; Lozano, M Luz; Galy, Anne; Charrier, Sabine; von Kalle, Christof; Guenechea, Guillermo; Bueren, Juan A; Schmidt, Manfred

2015-01-01

Fanconi anemia is a DNA repair-deficiency syndrome mainly characterized by cancer predisposition and bone marrow failure. Trying to restore the hematopoietic function in these patients, lentiviral vector-mediated gene therapy trials have recently been proposed. However, because no insertional oncogenesis studies have been conducted so far in DNA repair-deficiency syndromes such as Fanconi anemia, we have carried out a genome-wide screening of lentiviral insertion sites after the gene correction of Fanca(-/-) hematopoietic stem cells (HSCs), using LAM-PCR and 454-pyrosequencing. Our studies first demonstrated that transduction of Fanca(-/-) HSCs with a lentiviral vector designed for clinical application efficiently corrects the phenotype of Fanconi anemia repopulating cells without any sign of toxicity. The identification of more than 6,500 insertion sites in primary and secondary recipients showed a polyclonal pattern of reconstitution, as well as a continuous turnover of corrected Fanca(-/-) HSC clones, without evidences of selection towards specific common integration sites. Taken together our data show, for the first time in a DNA repair-deficiency syndrome, that lentiviral vector-mediated gene therapy efficiently corrects the phenotype of affected HSCs and promotes a healthy pattern of clonal turnover in vivo. These studies will have a particular impact in the development of new gene therapy trials in patients affected by DNA repair syndromes, particularly in Fanconi anemia.

Delivery of the Cre recombinase by a self-deleting lentiviral vector: efficient gene targeting in vivo

NARCIS (Netherlands)

Pfeifer, A.; Brandon, E. P.; Kootstra, N.; Gage, F. H.; Verma, I. M.

2001-01-01

The Cre recombinase (Cre) from bacteriophage P1 is an important tool for genetic engineering in mammalian cells. We constructed lentiviral vectors that efficiently deliver Cre in vitro and in vivo. Surprisingly, we found a significant reduction in proliferation and an accumulation in the G(2)/M

Engineering Cellular Resistance to HIV-1 Infection In Vivo Using a Dual Therapeutic Lentiviral Vector

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Bryan P Burke

2015-01-01

Full Text Available We described earlier a dual-combination anti-HIV type 1 (HIV-1 lentiviral vector (LVsh5/C46 that downregulates CCR5 expression of transduced cells via RNAi and inhibits HIV-1 fusion via cell surface expression of cell membrane-anchored C46 antiviral peptide. This combinatorial approach has two points of inhibition for R5-tropic HIV-1 and is also active against X4-tropic HIV-1. Here, we utilize the humanized bone marrow, liver, thymus (BLT mouse model to characterize the in vivo efficacy of LVsh5/C46 (Cal-1 vector to engineer cellular resistance to HIV-1 pathogenesis. Human CD34+ hematopoietic stem/progenitor cells (HSPC either nonmodified or transduced with LVsh5/C46 vector were transplanted to generate control and treatment groups, respectively. Control and experimental groups displayed similar engraftment and multilineage hematopoietic differentiation that included robust CD4+ T-cell development. Splenocytes isolated from the treatment group were resistant to both R5- and X4-tropic HIV-1 during ex vivo challenge experiments. Treatment group animals challenged with R5-tropic HIV-1 displayed significant protection of CD4+ T-cells and reduced viral load within peripheral blood and lymphoid tissues up to 14 weeks postinfection. Gene-marking and transgene expression were confirmed stable at 26 weeks post-transplantation. These data strongly support the use of LVsh5/C46 lentiviral vector in gene and cell therapeutic applications for inhibition of HIV-1 infection.

Staurosporine Increases Lentiviral Vector Transduction Efficiency of Human Hematopoietic Stem and Progenitor Cells

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Gretchen Lewis

2018-06-01

Full Text Available Lentiviral vector (LVV-mediated transduction of human CD34+ hematopoietic stem and progenitor cells (HSPCs holds tremendous promise for the treatment of monogenic hematological diseases. This approach requires the generation of a sufficient proportion of gene-modified cells. We identified staurosporine, a serine/threonine kinase inhibitor, as a small molecule that could be added to the transduction process to increase the proportion of genetically modified HSPCs by overcoming a LVV entry barrier. Staurosporine increased vector copy number (VCN approximately 2-fold when added to mobilized peripheral blood (mPB CD34+ cells prior to transduction. Limited staurosporine treatment did not affect viability of cells post-transduction, and there was no difference in in vitro colony formation compared to vehicle-treated cells. Xenotransplantation studies identified a statistically significant increase in VCN in engrafted human cells in mouse bone marrow at 4 months post-transplantation compared to vehicle-treated cells. Prostaglandin E2 (PGE2 is known to increase transduction efficiency of HSPCs through a different mechanism. Combining staurosporine and PGE2 resulted in further enhancement of transduction efficiency, particularly in short-term HSPCs. The combinatorial use of small molecules, such as staurosporine and PGE2, to enhance LVV transduction of human CD34+ cells is a promising method to improve transduction efficiency and subsequent potential therapeutic benefit of gene therapy drug products. Keywords: lentiviral, HSPC, transduction

Lentiviral Vector Design and Imaging Approaches to Visualize the Early Stages of Cellular Reprogramming

OpenAIRE

Warlich, Eva; Kuehle, Johannes; Cantz, Tobias; Brugman, Martijn H; Maetzig, Tobias; Galla, Melanie; Filipczyk, Adam A; Halle, Stephan; Klump, Hannes; Schöler, Hans R; Baum, Christopher; Schroeder, Timm; Schambach, Axel

2011-01-01

Induced pluripotent stem cells (iPSCs) can be derived from somatic cells by gene transfer of reprogramming transcription factors. Expression levels of these factors strongly influence the overall efficacy to form iPSC colonies, but additional contribution of stochastic cell-intrinsic factors has been proposed. Here, we present engineered color-coded lentiviral vectors in which codon-optimized reprogramming factors are co-expressed by a strong retroviral promoter that is rapidly silenced in iP...

Construction of a novel lentiviral vector carrying human B-domain ...

African Journals Online (AJOL)

USER

2010-03-29

Mar 29, 2010 ... Construction of the lentiviral expression vector. Both self-inactivating (SIN) ..... activated partial thromboplastin time. Figure 4. Expression of ... 1 entry to an endocytic pathway and suppresses both the requirement for Nef and ...

Resting lymphocyte transduction with measles virus glycoprotein pseudotyped lentiviral vectors relies on CD46 and SLAM

International Nuclear Information System (INIS)

Zhou Qi; Schneider, Irene C.; Gallet, Manuela; Kneissl, Sabrina; Buchholz, Christian J.

2011-01-01

The measles virus (MV) glycoproteins hemagglutinin (H) and fusion (F) were recently shown to mediate transduction of resting lymphocytes by lentiviral vectors. MV vaccine strains use CD46 or signaling lymphocyte activation molecule (SLAM) as receptor for cell entry. A panel of H protein mutants derived from vaccine strain or wild-type MVs that lost or gained CD46 or SLAM receptor usage were investigated for their ability to mediate gene transfer into unstimulated T lymphocytes. The results demonstrate that CD46 is sufficient for efficient vector particle association with unstimulated lymphocytes. For stable gene transfer into these cells, however, both MV receptors were found to be essential.

Prospects for Foamy Viral Vector Anti-HIV Gene Therapy

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Arun K. Nalla

2016-03-01

Full Text Available Stem cell gene therapy approaches for Human Immunodeficiency Virus (HIV infection have been explored in clinical trials and several anti-HIV genes delivered by retroviral vectors were shown to block HIV replication. However, gammaretroviral and lentiviral based retroviral vectors have limitations for delivery of anti-HIV genes into hematopoietic stem cells (HSC. Foamy virus vectors have several advantages including efficient delivery of transgenes into HSC in large animal models, and a potentially safer integration profile. This review focuses on novel anti-HIV transgenes and the potential of foamy virus vectors for HSC gene therapy of HIV.

Short-term cytotoxic effects and long-term instability of RNAi delivered using lentiviral vectors

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Kruithof Egbert KO

2004-08-01

Full Text Available Abstract Background RNA interference (RNAi can potently reduce target gene expression in mammalian cells and is in wide use for loss-of-function studies. Several recent reports have demonstrated that short double-stranded RNAs (dsRNAs, used to mediate RNAi, can also induce an interferon-based response resulting in changes in the expression of many interferon-responsive genes. Off-target gene silencing has also been described, bringing into question the validity of certain RNAi-based approaches for studying gene function. We have targeted the plasminogen activator inhibitor-2 (PAI-2 or SERPINB2 mRNA using lentiviral vectors for delivery of U6 promoter-driven PAI-2-targeted short hairpin RNA (shRNA expression. PAI-2 is reported to have anti-apoptotic activity, thus reduction of endogenous expression may be expected to make cells more sensitive to programmed cell death. Results As expected, we encountered a cytotoxic phenotype when targeting the PAI-2 mRNA with vector-derived shRNA. However, this predicted phenotype was a potent non-specific effect of shRNA expression, as functional overexpression of the target protein failed to rescue the phenotype. By decreasing the shRNA length or modifying its sequence we maintained PAI-2 silencing and reduced, but did not eliminate, cytotoxicity. ShRNA of 21 complementary nucleotides (21 mers or more increased expression of the oligoadenylate synthase-1 (OAS1 interferon-responsive gene. 19 mer shRNA had no effect on OAS1 expression but long-term selective pressure on cell growth was observed. By lowering lentiviral vector titre we were able to reduce both expression of shRNA and induction of OAS1, without a major impact on the efficacy of gene silencing. Conclusions Our data demonstrate a rapid cytotoxic effect of shRNAs expressed in human tumor cell lines. There appears to be a cut-off of 21 complementary nucleotides below which there is no interferon response while target gene silencing is maintained

Development of a replication-competent lentivirus assay for dendritic cell-targeting lentiviral vectors

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Daniel C Farley

Full Text Available It is a current regulatory requirement to demonstrate absence of detectable replication-competent lentivirus (RCL in lentiviral vector products prior to use in clinical trials. Immune Design previously described an HIV-1-based integration-deficient lentiviral vector for use in cancer immunotherapy (VP02. VP02 is enveloped with E1001, a modified Sindbis virus glycoprotein which targets dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN expressed on dendritic cells in vivo. Vector enveloped with E1001 does not transduce T-cell lines used in standard HIV-1-based RCL assays, making current RCL testing formats unsuitable for testing VP02. We therefore developed a novel assay to test for RCL in clinical lots of VP02. This assay, which utilizes a murine leukemia positive control virus and a 293F cell line expressing the E1001 receptor DC-SIGN, meets a series of evaluation criteria defined in collaboration with US regulatory authorities and demonstrates the ability of the assay format to amplify and detect a hypothetical RCL derived from VP02 vector components. This assay was qualified and used to test six independent GMP production lots of VP02, in which no RCL was detected. We propose that the evaluation criteria used to rationally design this novel method should be considered when developing an RCL assay for any lentiviral vector.

Production of germline transgenic prairie voles (Microtus ochrogaster) using lentiviral vectors.

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Donaldson, Zoe R; Yang, Shang-Hsun; Chan, Anthony W S; Young, Larry J

2009-12-01

The study of alternative model organisms has yielded tremendous insights into the regulation of behavioral and physiological traits not displayed by more widely used animal models, such as laboratory rats and mice. In particular, comparative approaches often exploit species ideally suited for investigating specific phenomenon. For instance, comparative studies of socially monogamous prairie voles and polygamous meadow voles have been instrumental toward gaining an understanding of the genetic and neurobiological basis of social bonding. However, laboratory studies of less commonly used organisms, such as prairie voles, have been limited by a lack of genetic tools, including the ability to manipulate the genome. Here, we show that lentiviral vector-mediated transgenesis is a rapid and efficient approach for creating germline transgenics in alternative laboratory rodents. Injection of a green fluorescent protein (GFP)-expressing lentiviral vector into the perivitelline space of 23 single-cell embryos yielded three live offspring (13 %), one of which (33%) contained germline integration of a GFP transgene driven by the human ubiquitin-C promoter. In comparison, transfer of 23 uninjected embryos yielded six live offspring (26%). Green fluorescent protein is present in all tissues examined and is expressed widely in the brain. The GFP transgene is heritable and stably expressed until at least the F(2) generation. This technology has the potential to allow investigation of specific gene candidates in prairie voles and provides a general protocol to pursue germline transgenic manipulation in many different rodent species.

Stable suppression of myostatin gene expression in goat fetal fibroblast cells by lentiviral vector-mediated RNAi.

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Patel, Utsav A; Patel, Amrutlal K; Joshi, Chaitanya G

2015-01-01

Myostatin (MSTN) is a secreted growth factor that negatively regulates skeletal muscle mass, and therefore, strategies to block myostatin-signaling pathway have been extensively pursued to increase the muscle mass in livestock. Here, we report a lentiviral vector-based delivery of shRNA to disrupt myostatin expression into goat fetal fibroblasts (GFFs) that were commonly used as karyoplast donors in somatic-cell nuclear transfer (SCNT) studies. Sh-RNA positive cells were screened by puromycin selection. Using real-time polymerase chain reaction (PCR), we demonstrated efficient knockdown of endogenous myostatin mRNA with 64% down-regulation in sh2 shRNA-treated GFF cells compared to GFF cells treated by control lentivirus without shRNA. Moreover, we have also demonstrated both the induction of interferon response and the expression of genes regulating myogenesis in GFF cells. The results indicate that myostatin-targeting siRNA produced endogenously could efficiently down-regulate myostatin expression. Therefore, targeted knockdown of the MSTN gene using lentivirus-mediated shRNA transgenics would facilitate customized cell engineering, allowing potential use in the establishment of stable cell lines to produce genetically engineered animals. © 2014 American Institute of Chemical Engineers.

Construction of a CD147 Lentiviral Expression Vector and Establishment of Its Stably Transfected A549 Cell Line

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Shaoxing YANG

2012-12-01

Full Text Available Background and objective CD147, a type of transmembrane glycoprotein embedded on the surface of tumor cells, can promote tumor invasion and metastasis. This aim of this study is to construct a CD147 lentiviral expression vector, establish its stably transfected A549 cell line, and observe the effect of CD147 on MMP-9 proliferation as well as on the invasive ability of human lung adenocarcinoma cells. Methods Full-length CD147 gene was amplified by real-time polymerase chain reaction (RT-PCR, inserted into a pEGFP vector to construct pEGFP-CD147 and pEGFP vectors, and then transfected into 293FT cells to precede the lentivirus equipment package. Subsequently, we collected the lentivirus venom to infect the A549 cells and establish a stable, overexpressed cell line named A549-CD147. The mRNA expression of MMP-9 was examined by RT-PCR. The proliferation and invasive ability of the human lung cancer cells before and after transfection were examined by the CCK-8 and Transwell methods. Results A CD147 lentiviral expression vector (pEGFP-CD147 was successfully constructed by restrictive enzyme digestion and plasmid sequencing. RT-PCR and Western blot analyses revealed increased mRNA and protein expression of CD147 gene in cells transfected with pEGFP-CD147 compared with the control groups. Therefore, the A549-CD147 cell line was successfully established through the experiment. The mRNA expression of MMP-9 also significantly increased after the upregulation of CD147 expression. Meanwhile, CCK-8 and Transwell assays indicated that the proliferation and invasive ability significantly increased in the A549-CD147 cells. Conclusion A lentiviral CD147 expression vector and its A549 cell line (A549-CD14 were successfully constructed. CD147 overexpression upregulated the protein expression of MMP-9, and strengthened the proliferation and invasive ability of human lung adenocarcinoma cells.

Phenotypic correction of von Willebrand disease type 3 blood-derived endothelial cells with lentiviral vectors expressing von Willebrand factor

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De Meyer, Simon F.; Vanhoorelbeke, Karen; Chuah, Marinee K.; Pareyn, Inge; Gillijns, Veerle; Hebbel, Robert P.; Collen, Désiré; Deckmyn, Hans; VandenDriessche, Thierry

2006-01-01

Von Willebrand disease (VWD) is an inherited bleeding disorder, caused by quantitative (type 1 and 3) or qualitative (type 2) defects in von Willebrand factor (VWF). Gene therapy is an appealing strategy for treatment of VWD because it is caused by a single gene defect and because VWF is secreted into the circulation, obviating the need for targeting specific organs or tissues. However, development of gene therapy for VWD has been hampered by the considerable length of the VWF cDNA (8.4 kb [kilobase]) and the inherent complexity of the VWF protein that requires extensive posttranslational processing. In this study, a gene-based approach for VWD was developed using lentiviral transduction of blood-outgrowth endothelial cells (BOECs) to express functional VWF. A lentiviral vector encoding complete human VWF was used to transduce BOECs isolated from type 3 VWD dogs resulting in high-transduction efficiencies (95.6% ± 2.2%). Transduced VWD BOECs efficiently expressed functional vector-encoded VWF (4.6 ± 0.4 U/24 hour per 106 cells), with normal binding to GPIbα and collagen and synthesis of a broad range of multimers resulting in phenotypic correction of these cells. These results indicate for the first time that gene therapy of type 3 VWD is feasible and that BOECs are attractive target cells for this purpose. PMID:16478886

An adeno-associated viral vector transduces the rat hypothalamus and amygdala more efficient than a lentiviral vector

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Vreugdenhil Erno

2010-07-01

Full Text Available Abstract Background This study compared the transduction efficiencies of an adeno-associated viral (AAV vector, which was pseudotyped with an AAV1 capsid and encoded the green fluorescent protein (GFP, with a lentiviral (LV vector, which was pseudotyped with a VSV-G envelop and encoded the discosoma red fluorescent protein (dsRed, to investigate which viral vector transduced the lateral hypothalamus or the amygdala more efficiently. The LV-dsRed and AAV1-GFP vector were mixed and injected into the lateral hypothalamus or into the amygdala of adult rats. The titers that were injected were 1 × 108 or 1 × 109 genomic copies of AAV1-GFP and 1 × 105 transducing units of LV-dsRed. Results Immunostaining for GFP and dsRed showed that AAV1-GFP transduced significantly more cells than LV-dsRed in both the lateral hypothalamus and the amygdala. In addition, the number of LV particles that were injected can not easily be increased, while the number of AAV1 particles can be increased easily with a factor 100 to 1000. Both viral vectors appear to predominantly transduce neurons. Conclusions This study showed that AAV1 vectors are better tools to overexpress or knockdown genes in the lateral hypothalamus and amygdala of adult rats, since more cells can be transduced with AAV1 than with LV vectors and the titer of AAV1 vectors can easily be increased to transduce the area of interest.

Lentiviral gene transfer regenerates hematopoietic stem cells in a mouse model for Mpl-deficient aplastic anemia.

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Heckl, Dirk; Wicke, Daniel C; Brugman, Martijn H; Meyer, Johann; Schambach, Axel; Büsche, Guntram; Ballmaier, Matthias; Baum, Christopher; Modlich, Ute

2011-04-07

Thpo/Mpl signaling plays an important role in the maintenance of hematopoietic stem cells (HSCs) in addition to its role in megakaryopoiesis. Patients with inactivating mutations in Mpl develop thrombocytopenia and aplastic anemia because of progressive loss of HSCs. Yet, it is unknown whether this loss of HSCs is an irreversible process. In this study, we used the Mpl knockout (Mpl(-/-)) mouse model and expressed Mpl from newly developed lentiviral vectors specifically in the physiologic Mpl target populations, namely, HSCs and megakaryocytes. After validating lineage-specific expression in vivo using lentiviral eGFP reporter vectors, we performed bone marrow transplantation of transduced Mpl(-/-) bone marrow cells into Mpl(-/-) mice. We show that restoration of Mpl expression from transcriptionally targeted vectors prevents lethal adverse reactions of ectopic Mpl expression, replenishes the HSC pool, restores stem cell properties, and corrects platelet production. In some mice, megakaryocyte counts were atypically high, accompanied by bone neo-formation and marrow fibrosis. Gene-corrected Mpl(-/-) cells had increased long-term repopulating potential, with a marked increase in lineage(-)Sca1(+)cKit(+) cells and early progenitor populations in reconstituted mice. Transcriptome analysis of lineage(-)Sca1(+)cKit(+) cells in Mpl-corrected mice showed functional adjustment of genes involved in HSC self-renewal.

Comparison of lentiviral and sleeping beauty mediated αβ T cell receptor gene transfer.

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Anne-Christine Field

Full Text Available Transfer of tumour antigen-specific receptors to T cells requires efficient delivery and integration of transgenes, and currently most clinical studies are using gamma retroviral or lentiviral systems. Whilst important proof-of-principle data has been generated for both chimeric antigen receptors and αβ T cell receptors, the current platforms are costly, time-consuming and relatively inflexible. Alternative, more cost-effective, Sleeping Beauty transposon-based plasmid systems could offer a pathway to accelerated clinical testing of a more diverse repertoire of recombinant high affinity T cell receptors. Nucleofection of hyperactive SB100X transposase-mediated stable transposition of an optimised murine-human chimeric T cell receptor specific for Wilm's tumour antigen from a Sleeping Beauty transposon plasmid. Whilst transfer efficiency was lower than that mediated by lentiviral transduction, cells could be readily enriched and expanded, and mediated effective target cells lysis in vitro and in vivo. Integration sites of transposed TCR genes in primary T cells were almost randomly distributed, contrasting the predilection of lentiviral vectors for transcriptionally active sites. The results support exploitation of the Sleeping Beauty plasmid based system as a flexible and adaptable platform for accelerated, early-phase assessment of T cell receptor gene therapies.

Direct gene transfer in the Gottingen minipig CNS using stereotaxic lentiviral microinjections

DEFF Research Database (Denmark)

GLUD, AN; Hedegaard, Claus; Nielsen, Mette Slot

2010-01-01

We aim to induce direct viral mediated gene transfer in the substantia nigra (SN) of the Gottingen minipig using MRI guided stereotaxic injections of lentiviral vectors encoding enhanced green fluorescent protein (EGFP). Nine female Gottingen minipigs were injected unilaterally into the SN with 6...... per 2.5 microliters lentivirus capable of transducing cells and mediating expression of recombinant EGFP. The animals were euthanized after four (n=3) or twenty weeks (n=6). Fresh brain tissue from three animals was used for PCR. The remaining six brains were cryo- or paraffin...

Efficient and sustained IGF-1 expression in the adipose tissue-derived stem cells mediated via a lentiviral vector.

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Chen, Ting; Huang, Dangsheng; Chen, Guanghui; Yang, Tingshu; Yi, Jun; Tian, Miao

2015-02-01

The adipose tissue-derived stem cells (ADSCs) represent a significant area of the cell therapy. Genetic modification of ADSCs may further improve their therapeutic potential. Here, we aimed to generate a lentiviral vector expressing insulin-like growth factor-I (IGF-1) and investigate the impact of IGF-1 transduction on the properties of cultured ADSCs. Isolated rat ADSCs were assessed by flow cytometric analysis. IGF-1 was cloned and inserted into the pLenO-DCE plasmid to acquire pLenO-DCE-IGF-1 plasmid. Lentivirus was enveloped with pRsv-REV, pMDlg-pRRE and pMD2G plasmids in 293T cells. The ADSCs were transfected with the vectors. And then IGF-1-induced anti-apoptosis was evaluated by annexin V-FITC. Besides, proliferation of cells was detected by MTT assay and EdU. Moreover, Akt phosphorylation was evaluated by Western blotting analysis. Stable expression of IGF-1 in ADSCs was confirmed. ADSCs were positive for CD90 and CD29, but negative for CD31, CD34 and CD45. The transduction of IGF-1 to the ADSCs caused a dramatic increase in P-Akt expression. Over-expression of IGF-1 in ADSCs could improve the paracine of IGF-1 in a time-dependent manner, but could not promote the proliferation of ADSCs. This study indicated that lentiviral vectors offered a promising mean of delivering IGF-1 to the ADSCs. Lentiviral-mediated over-expression of therapeutic IGF-1 gene in ADSCs could prolong the anti-apoptosis effect of IGF-1, which might be induced by the activation of the PI3K/Akt pathway. And our data would improve the efficacy of ADSC-based therapies.

Effective in vivo and ex vivo gene transfer to intestinal mucosa by VSV-G-pseudotyped lentiviral vectors

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Kasahara Noriyuki

2010-05-01

Full Text Available Abstract Background Gene transfer to the gastrointestinal (GI mucosa is a therapeutic strategy which could prove particularly advantageous for treatment of various hereditary and acquired intestinal disorders, including inflammatory bowel disease (IBD, GI infections, and cancer. Methods We evaluated vesicular stomatitis virus glycoprotein envelope (VSV-G-pseudotyped lentiviral vectors (LV for efficacy of gene transfer to both murine rectosigmoid colon in vivo and human colon explants ex vivo. LV encoding beta-galactosidase (LV-β-Gal or firefly-luciferase (LV-fLuc reporter genes were administered by intrarectal instillation in mice, or applied topically for ex vivo transduction of human colorectal explant tissues from normal individuals. Macroscopic and histological evaluations were performed to assess any tissue damage or inflammation. Transduction efficiency and systemic biodistribution were evaluated by real-time quantitative PCR. LV-fLuc expression was evaluated by ex vivo bioluminescence imaging. LV-β-Gal expression and identity of transduced cell types were examined by histochemical and immunofluorescence staining. Results Imaging studies showed positive fLuc signals in murine distal colon; β-Gal-positive cells were found in both murine and human intestinal tissue. In the murine model, β-Gal-positive epithelial and lamina propria cells were found to express cytokeratin, CD45, and CD4. LV-transduced β-Gal-positive cells were also seen in human colorectal explants, consisting mainly of CD45, CD4, and CD11c-positive cells confined to the LP. Conclusions We have demonstrated the feasibility of LV-mediated gene transfer into colonic mucosa. We also identified differential patterns of mucosal gene transfer dependent on whether murine or human tissue was used. Within the limitations of the study, the LV did not appear to induce mucosal damage and were not distributed beyond the distal colon.

A lentiviral vector with expression controlled by E2F-1: A potential tool for the study and treatment of proliferative diseases

International Nuclear Information System (INIS)

Strauss, Bryan E.; Patricio, Juliana Rotelli; Vieira de Carvalho, Anna Carolina; Bajgelman, Marcio C.

2006-01-01

We have constructed a lentiviral vector with expression limited to cells presenting active E2F-1 protein, a potential advantage for gene therapy of proliferative diseases. For the FE2FLW vector, the promoter region of the human E2F-1 gene was utilized to drive expression of luciferase cDNA, included as a reporter of viral expression. Primary, immortalized, and transformed cells were transduced with the FE2FLW vector and cell cycle alterations were induced with serum starvation/replacement, contact inhibition or drug treatment, revealing cell cycle-dependent changes in reporter activity. Forced E2F-1 expression, but not E2F-2 or E2F-3, increased reporter activity, indicating a major role for this factor in controlling expression from the FE2FLW virus. We show the utility of this vector as a reporter of E2F-1 and proliferation-dependent cellular alterations upon cytotoxic/cytostatic treatment, such as the introduction of tumor suppressor genes. We propose that the FE2FLW vector may be a starting point for the development of gene therapy strategies for proliferative diseases, such as cancer or restinosis

Genetic engineering of cell lines using lentiviral vectors to achieve antibody secretion following encapsulated implantation.

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Lathuilière, Aurélien; Bohrmann, Bernd; Kopetzki, Erhard; Schweitzer, Christoph; Jacobsen, Helmut; Moniatte, Marc; Aebischer, Patrick; Schneider, Bernard L

2014-01-01

The controlled delivery of antibodies by immunoisolated bioimplants containing genetically engineered cells is an attractive and safe approach for chronic treatments. To reach therapeutic antibody levels there is a need to generate renewable cell lines, which can long-term survive in macroencapsulation devices while maintaining high antibody specific productivity. Here we have developed a dual lentiviral vector strategy for the genetic engineering of cell lines compatible with macroencapsulation, using separate vectors encoding IgG light and heavy chains. We show that IgG expression level can be maximized as a function of vector dose and transgene ratio. This approach allows for the generation of stable populations of IgG-expressing C2C12 mouse myoblasts, and for the subsequent isolation of clones stably secreting high IgG levels. Moreover, we demonstrate that cell transduction using this lentiviral system leads to the production of a functional glycosylated antibody by myogenic cells. Subsequent implantation of antibody-secreting cells in a high-capacity macroencapsulation device enables continuous delivery of recombinant antibodies in the mouse subcutaneous tissue, leading to substantial levels of therapeutic IgG detectable in the plasma.

Transcriptional Enhancers Induce Insertional Gene Deregulation Independently From the Vector Type and Design

Science.gov (United States)

Maruggi, Giulietta; Porcellini, Simona; Facchini, Giulia; Perna, Serena K; Cattoglio, Claudia; Sartori, Daniela; Ambrosi, Alessandro; Schambach, Axel; Baum, Christopher; Bonini, Chiara; Bovolenta, Chiara; Mavilio, Fulvio; Recchia, Alessandra

2009-01-01

The integration characteristics of retroviral (RV) vectors increase the probability of interfering with the regulation of cellular genes, and account for a tangible risk of insertional mutagenesis in treated patients. To assess the potential genotoxic risk of conventional or self-inactivating (SIN) γ-RV and lentiviral (LV) vectors independently from the biological consequences of the insertion event, we developed a quantitative assay based on real-time reverse transcriptase—PCR on low-density arrays to evaluate alterations of gene expression in individual primary T-cell clones. We show that the Moloney leukemia virus long terminal repeat (LTR) enhancer has the strongest activity in both a γ-RV and a LV vector context, while an internal cellular promoter induces deregulation of gene expression less frequently, at a shorter range and to a lower extent in both vector types. Downregulation of gene expression was observed only in the context of LV vectors. This study indicates that insertional gene activation is determined by the characteristics of the transcriptional regulatory elements carried by the vector, and is largely independent from the vector type or design. PMID:19293778

Pretransplant mobilization with granulocyte colony-stimulating factor improves B-cell reconstitution by lentiviral vector gene therapy in SCID-X1 mice.

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Huston, Marshall W; Riegman, Adriaan R A; Yadak, Rana; van Helsdingen, Yvette; de Boer, Helen; van Til, Niek P; Wagemaker, Gerard

2014-10-01

Hematopoietic stem cell (HSC) gene therapy is a demonstrated effective treatment for X-linked severe combined immunodeficiency (SCID-X1), but B-cell reconstitution and function has been deficient in many of the gene therapy treated patients. Cytoreductive preconditioning is known to improve HSC engraftment, but in general it is not considered for SCID-X1 since the poor health of most of these patients at diagnosis and the risk of toxicity preclude the conditioning used in standard bone marrow stem cell transplantation. We hypothesized that mobilization of HSC by granulocyte colony-stimulating factor (G-CSF) should create temporary space in bone marrow niches to improve engraftment and thereby B-cell reconstitution. In the present pilot study supplementing our earlier preclinical evaluation (Huston et al., 2011), Il2rg(-/-) mice pretreated with G-CSF were transplanted with wild-type lineage negative (Lin(-)) cells or Il2rg(-/-) Lin(-) cells transduced with therapeutic IL2RG lentiviral vectors. Mice were monitored for reconstitution of lymphocyte populations, level of donor cell chimerism, and antibody responses as compared to 2 Gy total body irradiation (TBI), previously found effective in promoting B-cell reconstitution. The results demonstrate that G-CSF promotes B-cell reconstitution similar to low-dose TBI and provides proof of principle for an alternative approach to improve efficacy of gene therapy in SCID patients without adverse effects associated with cytoreductive conditioning.

Overexpression of thioredoxin in islets transduced by a lentiviral vector prolongs graft survival in autoimmune diabetic NOD mice

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Sytwu Huey-Kang

2009-08-01

Full Text Available Abstract Pancreatic islet transplantation is considered an appropriate treatment to achieve insulin independence in type I diabetic patients. However, islet isolation and transplantation-induced oxidative stress and autoimmune-mediated destruction are still the major obstacles to the long-term survival of graft islets in this potential therapy. To protect islet grafts from inflammatory damage and prolong their survival, we transduced islets with an antioxidative gene thioredoxin (TRX using a lentiviral vector before transplantation. We hypothesized that the overexpression of TRX in islets would prolong islet graft survival when transplanted into diabetic non-obese diabetic (NOD mice. Methods Islets were isolated from NOD mice and transduced with lentivirus carrying TRX (Lt-TRX or enhanced green fluorescence protein (Lt-eGFP, respectively. Transduced islets were transplanted under the left kidney capsule of female diabetic NOD mice, and blood glucose concentration was monitored daily after transplantation. The histology of the islet graft was assessed at the end of the study. The protective effect of TRX on islets was investigated. Results The lentiviral vector effectively transduced islets without altering the glucose-stimulating insulin-secretory function of islets. Overexpression of TRX in islets reduced hydrogen peroxide-induced cytotoxicity in vitro. After transplantation into diabetic NOD mice, euglycemia was maintained for significantly longer in Lt-TRX-transduced islets than in Lt-eGFP-transduced islets; the mean graft survival was 18 vs. 6.5 days (n = 9 and 10, respectively, p Conclusion We successfully transduced the TRX gene into islets and demonstrated that these genetically modified grafts are resistant to inflammatory insult and survived longer in diabetic recipients. Our results further support the concept that the reactive oxygen species (ROS scavenger and antiapoptotic functions of TRX are critical to islet survival after

Potent and reversible lentiviral vector restriction in murine induced pluripotent stem cells.

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Geis, Franziska K; Galla, Melanie; Hoffmann, Dirk; Kuehle, Johannes; Zychlinski, Daniela; Maetzig, Tobias; Schott, Juliane W; Schwarzer, Adrian; Goffinet, Christine; Goff, Stephen P; Schambach, Axel

2017-05-31

Retroviral vectors are derived from wild-type retroviruses, can be used to study retrovirus-host interactions and are effective tools in gene and cell therapy. However, numerous cell types are resistant or less permissive to retrovirus infection due to the presence of active defense mechanisms, or the absence of important cellular host co-factors. In contrast to multipotent stem cells, pluripotent stem cells (PSC) have potential to differentiate into all three germ layers. Much remains to be elucidated in the field of anti-viral immunity in stem cells, especially in PSC. In this study, we report that transduction with HIV-1-based, lentiviral vectors (LV) is impaired in murine PSC. Analyses of early retroviral events in induced pluripotent stem cells (iPSC) revealed that the restriction is independent of envelope choice and does not affect reverse transcription, but perturbs nuclear entry and proviral integration. Proteasomal inhibition by MG132 could not circumvent the restriction. However, prevention of cyclophilin A (CypA) binding to the HIV-1 capsid via use of either a CypA inhibitor (cyclosporine A) or CypA-independent capsid mutants improved transduction. In addition, application of higher vector doses also increased transduction. Our data revealed a CypA mediated restriction in iPSC, which was acquired during reprogramming, associated with pluripotency and relieved upon subsequent differentiation. We showed that murine PSC and iPSC are less susceptible to LV. The block observed in iPSC was CypA-dependent and resulted in reduced nuclear entry of viral DNA and proviral integration. Our study helps to improve transduction of murine pluripotent cells with HIV-1-based vectors and contributes to our understanding of retrovirus-host interactions in PSC.

Quantitative analysis of lentiviral transgene expression in mice over seven generations.

Science.gov (United States)

Wang, Yong; Song, Yong-tao; Liu, Qin; Liu, Cang'e; Wang, Lu-lu; Liu, Yu; Zhou, Xiao-yang; Wu, Jun; Wei, Hong

2010-10-01

Lentiviral transgenesis is now recognized as an extremely efficient and cost-effective method to produce transgenic animals. Transgenes delivered by lentiviral vectors exhibited inheritable expression in many species including those which are refractory to genetic modification such as non-human primates. However, epigenetic modification was frequently observed in lentiviral integrants, and transgene expression found to be inversely correlated with methylation density. Recent data showed that about one-third lentiviral integrants exhibited hypermethylation and low expression, but did not demonstrate whether those integrants with high expression could remain constant expression and hypomethylated during long term germline transmission. In this study, using lentiviral eGFP transgenic mice as the experimental animals, lentiviral eGFP expression levels and its integrant numbers in genome were quantitatively analyzed by fluorescent quantitative polymerase-chain reaction (FQ-PCR), using the house-keeping gene ribosomal protein S18 (Rps18) and the single copy gene fatty acid binding protein of the intestine (Fabpi) as the internal controls respectively. The methylation densities of the integrants were quantitatively analyzed by bisulfite sequencing. We found that the lentiviral integrants with high expression exhibited a relative constant expression level per integrant over at least seven generations. Besides, the individuals containing these integrants exhibited eGFP expression levels which were positively and almost linearly correlated with the integrant numbers in their genomes, suggesting that no remarkable position effect on transgene expression of the integrants analyzed was observed. In addition, over seven generations the methylation density of these integrants did not increase, but rather decreased remarkably, indicating that these high expressing integrants were not subjected to de novo methylation during at least seven generations of germline transmission. Taken

Comparison of Human Sodium/Iodide Symporter (hNIS) Gene Expressions between Lentiviral and Adenoviral Vectors in Rat Mesenchymal Stem Cells

Energy Technology Data Exchange (ETDEWEB)

Park, So Yeon; Lee, Won Woo; Kim, Hyun Joo; Chung, June Key; Kim, Sang Eun [Seoul National University College of Medicine, Seoul (Korea, Republic of); Kim, Sung Jin; Lee, Heui Ran [Medical Research Center, Seoul National University, Seoul (Korea, Republic of)

2008-10-15

Quantitative comparison of transgene expression within stem cells between lentivirus and adenovirusmediated delivery systems has not been reported. Here, we evaluated the human sodium iodide symporter (hNIS) gene expression in rat mesenchymal stem cell (rMSC) transduced by lentivirus or adenovirus, and compared the hNIS expression quantitatively between the two delivery systems. Lentiviral-mediated hNIS expressing rMSC (lenti-hNIS-rMSC) was constructed by cloning hNIS gene into pLenti6/UbC/V5-DEST (Invitrogen) to obtain pLenti-hNIS, transducing rMSC with the pLenti-hNIS, and selecting with blasticidin for 3 weeks. Recombinant adenovirus expressing hNIS gene (Rad-hNIS) was produced by homologous recombination and transduction efficiency of Rad-hNIS into rMSC evaluated by Rad-GFP was 19.1{+-}4.7%, 54.0{+-}6.4%, 85.7{+-}8.7%, and 98.4{+-}1.3% at MOI 1, 5, 20, and 100, respectively. The hNIS expressions in lenti-hNIS-rMSC or adeno-hNIS-rMSC were assessed by immunocytochemistry, western blot, and I-125 uptake. Immunocytochemistry and western blot analyses revealed that hNIS expressions in lenti-hNIS-rMSC were greater than those in adeno-hNIS-rMSC at MOI 20 but lower than at MOI 50. However in vitro I-125 uptake test demonstrated that iodide uptake in lenti-hNIS-rMSC (29,704{+-}6,659 picomole/10{sup 6} cells) was greater than that in adeno-hNIS-rMSC at MOI 100 (6,168{+-}2,134 picomole/10{sup 6} cells). Despite lower amount of expressed protein, hNIS function in rMSC was greater by lentivirus than by adenovirus mediated expression. Stem cell tracking using hNIS as a reporter gene should be conducted in consideration of relative vector efficiency for transgene expression.

Gene delivery to pancreatic exocrine cells in vivo and in vitro

Directory of Open Access Journals (Sweden)

Houbracken Isabelle

2012-10-01

Full Text Available Abstract Background Effective gene transfer to the pancreas or to pancreatic cells has remained elusive although it is essential for studies of genetic lineage tracing and modulation of gene expression. Different transduction methods and viral vectors were tested in vitro and in vivo, in rat and mouse pancreas. Results For in vitro transfection/transduction of rat exocrine cells lipofection reagents, adenoviral vectors, and Mokola- and VSV-G pseudotyped lentiviral vectors were used. For in vivo transduction of mouse and rat pancreas adenoviral vectors and VSV-G lentiviral vectors were injected into the parenchymal tissue. Both lipofection of rat exocrine cell cultures and transduction with Mokola pseudotyped lentiviral vectors were inefficient and resulted in less than 4% EGFP expressing cells. Adenoviral transduction was highly efficient but its usefulness for gene delivery to rat exocrine cells in vitro was hampered by a drastic increase in cell death. In vitro transduction of rat exocrine cells was most optimal with VSV-G pseudotyped lentiviral vectors, with stable transgene expression, no significant effect on cell survival and about 40% transduced cells. In vivo, pancreatic cells could not be transduced by intra-parenchymal administration of lentiviral vectors in mouse and rat pancreas. However, a high efficiency could be obtained by adenoviral vectors, resulting in transient transduction of mainly exocrine acinar cells. Injection in immune-deficient animals diminished leukocyte infiltration and prolonged transgene expression. Conclusions In summary, our study remarkably demonstrates that transduction of pancreatic exocrine cells requires lentiviral vectors in vitro but adenoviral vectors in vivo.

A nonintegrative lentiviral vector-based vaccine provides long-term sterile protection against malaria.

Directory of Open Access Journals (Sweden)

Frédéric Coutant

Full Text Available Trials testing the RTS,S candidate malaria vaccine and radiation-attenuated sporozoites (RAS have shown that protective immunity against malaria can be induced and that an effective vaccine is not out of reach. However, longer-term protection and higher protection rates are required to eradicate malaria from the endemic regions. It implies that there is still a need to explore new vaccine strategies. Lentiviral vectors are very potent at inducing strong immunological memory. However their integrative status challenges their safety profile. Eliminating the integration step obviates the risk of insertional oncogenesis. Providing they confer sterile immunity, nonintegrative lentiviral vectors (NILV hold promise as mass pediatric vaccine by meeting high safety standards. In this study, we have assessed the protective efficacy of NILV against malaria in a robust pre-clinical model. Mice were immunized with NILV encoding Plasmodium yoelii Circumsporozoite Protein (Py CSP and challenged with sporozoites one month later. In two independent protective efficacy studies, 50% (37.5-62.5 of the animals were fully protected (p = 0.0072 and p = 0.0008 respectively when compared to naive mice. The remaining mice with detectable parasitized red blood cells exhibited a prolonged patency and reduced parasitemia. Moreover, protection was long-lasting with 42.8% sterile protection six months after the last immunization (p = 0.0042. Post-challenge CD8+ T cells to CSP, in contrast to anti-CSP antibodies, were associated with protection (r = -0.6615 and p = 0.0004 between the frequency of IFN-g secreting specific T cells in spleen and parasitemia. However, while NILV and RAS immunizations elicited comparable immunity to CSP, only RAS conferred 100% of sterile protection. Given that a better protection can be anticipated from a multi-antigen vaccine and an optimized vector design, NILV appear as a promising malaria vaccine.

Packaging of HCV-RNA into lentiviral vector

International Nuclear Information System (INIS)

Caval, Vincent; Piver, Eric; Ivanyi-Nagy, Roland; Darlix, Jean-Luc; Pagès, Jean-Christophe

2011-01-01

Highlights: ► Description of HCV-RNA Core-D1 interactions. ► In vivo evaluation of the packaging of HCV genome. ► Determination of the role of the three basic sub-domains of D1. ► Heterologous system involving HIV-1 vector particles to mobilise HCV genome. ► Full length mobilisation of HCV genome and HCV-receptor-independent entry. -- Abstract: The advent of infectious molecular clones of Hepatitis C virus (HCV) has unlocked the understanding of HCV life cycle. However, packaging of the genomic RNA, which is crucial to generate infectious viral particles, remains poorly understood. Molecular interactions of the domain 1 (D1) of HCV Core protein and HCV RNA have been described in vitro. Since compaction of genetic information within HCV genome has hampered conventional mutational approach to study packaging in vivo, we developed a novel heterologous system to evaluate the interactions between HCV RNA and Core D1. For this, we took advantage of the recruitment of Vpr fusion-proteins into HIV-1 particles. By fusing HCV Core D1 to Vpr we were able to package and transfer a HCV subgenomic replicon into a HIV-1 based lentiviral vector. We next examined how deletion mutants of basic sub-domains of Core D1 influenced HCV RNA recruitment. The results emphasized the crucial role of the first and third basic regions of D1 in packaging. Interestingly, the system described here allowed us to mobilise full-length JFH1 genome in CD81 defective cells, which are normally refractory to HCV infection. This finding paves the way to an evaluation of the replication capability of HCV in various cell types.

HIV-derived vectors for gene therapy targeting dendritic cells.

Science.gov (United States)

Rossetti, Maura; Cavarelli, Mariangela; Gregori, Silvia; Scarlatti, Gabriella

2013-01-01

Human immunodeficiency virus type 1 (HIV-1)-derived lentiviral vectors (LV) have the potential to mediate stable therapeutic gene transfer. However, similarly to other viral vectors, their benefit is compromised by the induction of an immune response toward transgene-expressing cells that closely mimics antiviral immunity. LV share with the parental HIV the ability to activate dendritic cells (DC), while lack the peculiar ability of subverting DC functions, which is responsible for HIV immune escape. Understanding the interaction between LV and DC, with plasmacytoid and myeloid DC playing fundamental and distinct roles, has paved the way to novel approaches aimed at regulating transgene-specific immune responses. Thanks to the ability to target either DC subsets LV might be a powerful tool to induce immunity (i.e., gene therapy of cancer), cell death (i.e., in HIV/AIDS infection), or tolerance (i.e., gene therapy strategies for monogenic diseases). In this chapter, similarities and differences between the LV-mediated and HIV-mediated induction of immune responses, with specific focus on their interactions with DC, are discussed.

Preclinical correction of human Fanconi anemia complementation group A bone marrow cells using a safety-modified lentiviral vector.

Science.gov (United States)

Becker, P S; Taylor, J A; Trobridge, G D; Zhao, X; Beard, B C; Chien, S; Adair, J; Kohn, D B; Wagner, J E; Shimamura, A; Kiem, H-P

2010-10-01

One of the major hurdles for the development of gene therapy for Fanconi anemia (FA) is the increased sensitivity of FA stem cells to free radical-induced DNA damage during ex vivo culture and manipulation. To minimize this damage, we have developed a brief transduction procedure for lentivirus vector-mediated transduction of hematopoietic progenitor cells from patients with Fanconi anemia complementation group A (FANCA). The lentiviral vector FancA-sW contains the phosphoglycerate kinase promoter, the FANCA cDNA, and a synthetic, safety-modified woodchuck post transcriptional regulatory element (sW). Bone marrow mononuclear cells or purified CD34(+) cells from patients with FANCA were transduced in an overnight culture on recombinant fibronectin peptide CH-296, in low (5%) oxygen, with the reducing agent, N-acetyl-L-cysteine (NAC), and a combination of growth factors, granulocyte colony-stimulating factor (G-CSF), Flt3 ligand, stem cell factor, and thrombopoietin. Transduced cells plated in methylcellulose in hypoxia with NAC showed increased colony formation compared with 21% oxygen without NAC (Pgene-corrected cells in patients with FANCA.

Differentiation of Human Mesenchymal Stem Cells into Insulin Producing Cells by Using A Lentiviral Vector Carrying PDX1.

Science.gov (United States)

Allahverdi, Amir; Abroun, Saied; Jafarian, Arefeh; Soleimani, Masoud; Taghikhani, Mohammad; Eskandari, Fatemeh

2015-01-01

Type I diabetes is an immunologically-mediated devastation of insulin producing cells (IPCs) in the pancreatic islet. Stem cells that produce β-cells are a new promising tool. Adult stem cells such as mesenchymal stem cells (MSCs) are self renewing multi potent cells showing capabilities to differentiate into ectodermal, mesodermal and endodermal tissues. Pancreatic and duodenal homeobox factor 1 (PDX1) is a master regulator gene required for embryonic development of the pancreas and is crucial for normal pancreatic islets activities in adults. We induced the over-expression of the PDX1 gene in human bone marrow MSCs (BM-MSCs) by Lenti-PDX1 in order to generate IPCs. Next, we examine the ability of the cells by measuring insulin/c-peptide production and INSULIN and PDX1 gene expressions. After transduction, MSCs changed their morphology at day 5 and gradually differentiated into IPCs. INSULIN and PDX1 expressions were confirmed by real time polymerase chain reaction (RT-PCR) and immunostaining. IPC secreted insulin and C-peptide in the media that contained different glucose concentrations. MSCs differentiated into IPCs by genetic manipulation. Our result showed that lentiviral vectors could deliver PDX1 gene to MSCs and induce pancreatic differentiation.

Packaging of HCV-RNA into lentiviral vector

Energy Technology Data Exchange (ETDEWEB)

Caval, Vincent [INSERM U966, Universite Francois Rabelais de Tours, Faculte de Medecine, 10 Bd. Tonnelle, 37000 Tours (France); Piver, Eric [INSERM U966, Universite Francois Rabelais de Tours, Faculte de Medecine, 10 Bd. Tonnelle, 37000 Tours (France); Service de Biochimie et Biologie Moleculaire, CHRU de Tours (France); Ivanyi-Nagy, Roland; Darlix, Jean-Luc [LaboRetro, ENS-Lyon INSERM, U758, 46 Allee d' Italie, 69364 Lyon (France); Pages, Jean-Christophe, E-mail: jean-christophe.pages@univ-tours.fr [INSERM U966, Universite Francois Rabelais de Tours, Faculte de Medecine, 10 Bd. Tonnelle, 37000 Tours (France); Service de Biochimie et Biologie Moleculaire, CHRU de Tours (France)

2011-11-04

Highlights: Black-Right-Pointing-Pointer Description of HCV-RNA Core-D1 interactions. Black-Right-Pointing-Pointer In vivo evaluation of the packaging of HCV genome. Black-Right-Pointing-Pointer Determination of the role of the three basic sub-domains of D1. Black-Right-Pointing-Pointer Heterologous system involving HIV-1 vector particles to mobilise HCV genome. Black-Right-Pointing-Pointer Full length mobilisation of HCV genome and HCV-receptor-independent entry. -- Abstract: The advent of infectious molecular clones of Hepatitis C virus (HCV) has unlocked the understanding of HCV life cycle. However, packaging of the genomic RNA, which is crucial to generate infectious viral particles, remains poorly understood. Molecular interactions of the domain 1 (D1) of HCV Core protein and HCV RNA have been described in vitro. Since compaction of genetic information within HCV genome has hampered conventional mutational approach to study packaging in vivo, we developed a novel heterologous system to evaluate the interactions between HCV RNA and Core D1. For this, we took advantage of the recruitment of Vpr fusion-proteins into HIV-1 particles. By fusing HCV Core D1 to Vpr we were able to package and transfer a HCV subgenomic replicon into a HIV-1 based lentiviral vector. We next examined how deletion mutants of basic sub-domains of Core D1 influenced HCV RNA recruitment. The results emphasized the crucial role of the first and third basic regions of D1 in packaging. Interestingly, the system described here allowed us to mobilise full-length JFH1 genome in CD81 defective cells, which are normally refractory to HCV infection. This finding paves the way to an evaluation of the replication capability of HCV in various cell types.

Lentiviral vectors and protocols for creation of stable hESC lines for fluorescent tracking and drug resistance selection of cardiomyocytes.

Directory of Open Access Journals (Sweden)

Hiroko Kita-Matsuo

Full Text Available Developmental, physiological and tissue engineering studies critical to the development of successful myocardial regeneration therapies require new ways to effectively visualize and isolate large numbers of fluorescently labeled, functional cardiomyocytes.Here we describe methods for the clonal expansion of engineered hESCs and make available a suite of lentiviral vectors for that combine Blasticidin, Neomycin and Puromycin resistance based drug selection of pure populations of stem cells and cardiomyocytes with ubiquitous or lineage-specific promoters that direct expression of fluorescent proteins to visualize and track cardiomyocytes and their progenitors. The phospho-glycerate kinase (PGK promoter was used to ubiquitously direct expression of histone-2B fused eGFP and mCherry proteins to the nucleus to monitor DNA content and enable tracking of cell migration and lineage. Vectors with T/Brachyury and alpha-myosin heavy chain (alphaMHC promoters targeted fluorescent or drug-resistance proteins to early mesoderm and cardiomyocytes. The drug selection protocol yielded 96% pure cardiomyocytes that could be cultured for over 4 months. Puromycin-selected cardiomyocytes exhibited a gene expression profile similar to that of adult human cardiomyocytes and generated force and action potentials consistent with normal fetal cardiomyocytes, documenting these parameters in hESC-derived cardiomyocytes and validating that the selected cells retained normal differentiation and function.The protocols, vectors and gene expression data comprise tools to enhance cardiomyocyte production for large-scale applications.

Optimal construction and delivery of dual-functioning lentiviral vectors for type I collagen-suppressed chondrogenesis in synovium-derived mesenchymal stem cells.

Science.gov (United States)

Zhang, Feng; Yao, Yongchang; Zhou, Ruijie; Su, Kai; Citra, Fudiman; Wang, Dong-An

2011-06-01

This study aims to deliver both transforming growth factor β3 (TGF-β3) and shRNA targeting type I collagen (Col I) by optimal construction and application of various dual-functioning lentiviral vectors to induce Col I-suppressed chondrogenesis in synovium-derived mesenchymal stem cells (SMSCs). We constructed four lentiviral vectors (LV-1, LV-2, LV-3 and LV-4) with various arrangements of the two expression cassettes in different positions and orientations. Col I inhibition efficiency and chondrogenic markers were assessed with qPCR, ELISA and staining techniques. Among the four vectors, LV-1 has two distant and reversely oriented cassettes, LV-2 has two distant and same-oriented cassettes, LV-3 has two proximal and reversely oriented cassettes, and LV-4 has two proximal and same-oriented cassettes. Col I and chondrogenic markers, including type II collagen (Col II), aggrecan and glycosaminoglycan (GAG), were examined in SMSCs cultured in 3-D alginate hydrogel. All of the four vectors showed distinct effects in Col I level as well as diverse inductive efficiencies in upregulation of the cartilaginous markers. Based on real-time PCR results, LV-1 was optimal towards Col I-suppressed chondrogenesis. LV-1 vector is competent to promote Col I-suppressed chondrogenesis in SMSCs.

Lentiviral Delivery of a Vesicular Glutamate Transporter 1 (VGLUT1)-Targeting Short Hairpin RNA Vector Into the Mouse Hippocampus Impairs Cognition

NARCIS (Netherlands)

King, Madeleine V.; Kurian, Nisha; Qin, Si; Papadopoulou, Nektaria; Westerink, Ben H. C.; Cremers, Thomas I.; Epping-Jordan, Mark P.; Le Poul, Emmanuel; Ray, David E.; Fone, Kevin C. F.; Kendall, David A.; Marsden, Charles A.; Sharp, Tyson V.

Glutamate is the principle excitatory neurotransmitter in the mammalian brain, and dysregulation of glutamatergic neurotransmission is implicated in the pathophysiology of several psychiatric and neurological diseases. This study utilized novel lentiviral short hairpin RNA (shRNA) vectors to target

Comparison of Human Sodium/Iodide Symporter (hNIS) Gene Expressions between Lentiviral and Adenoviral Vectors in Rat Mesenchymal Stem Cells

International Nuclear Information System (INIS)

Park, So Yeon; Lee, Won Woo; Kim, Hyun Joo; Chung, June Key; Kim, Sang Eun; Kim, Sung Jin; Lee, Heui Ran

2008-01-01

Quantitative comparison of transgene expression within stem cells between lentivirus and adenovirusmediated delivery systems has not been reported. Here, we evaluated the human sodium iodide symporter (hNIS) gene expression in rat mesenchymal stem cell (rMSC) transduced by lentivirus or adenovirus, and compared the hNIS expression quantitatively between the two delivery systems. Lentiviral-mediated hNIS expressing rMSC (lenti-hNIS-rMSC) was constructed by cloning hNIS gene into pLenti6/UbC/V5-DEST (Invitrogen) to obtain pLenti-hNIS, transducing rMSC with the pLenti-hNIS, and selecting with blasticidin for 3 weeks. Recombinant adenovirus expressing hNIS gene (Rad-hNIS) was produced by homologous recombination and transduction efficiency of Rad-hNIS into rMSC evaluated by Rad-GFP was 19.1±4.7%, 54.0±6.4%, 85.7±8.7%, and 98.4±1.3% at MOI 1, 5, 20, and 100, respectively. The hNIS expressions in lenti-hNIS-rMSC or adeno-hNIS-rMSC were assessed by immunocytochemistry, western blot, and I-125 uptake. Immunocytochemistry and western blot analyses revealed that hNIS expressions in lenti-hNIS-rMSC were greater than those in adeno-hNIS-rMSC at MOI 20 but lower than at MOI 50. However in vitro I-125 uptake test demonstrated that iodide uptake in lenti-hNIS-rMSC (29,704±6,659 picomole/10 6 cells) was greater than that in adeno-hNIS-rMSC at MOI 100 (6,168±2,134 picomole/10 6 cells). Despite lower amount of expressed protein, hNIS function in rMSC was greater by lentivirus than by adenovirus mediated expression. Stem cell tracking using hNIS as a reporter gene should be conducted in consideration of relative vector efficiency for transgene expression

Targeted genome editing by lentiviral protein transduction of zinc-finger and TAL-effector nucleases.

Science.gov (United States)

Cai, Yujia; Bak, Rasmus O; Mikkelsen, Jacob Giehm

2014-04-24

Future therapeutic use of engineered site-directed nucleases, like zinc-finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs), relies on safe and effective means of delivering nucleases to cells. In this study, we adapt lentiviral vectors as carriers of designer nuclease proteins, providing efficient targeted gene disruption in vector-treated cell lines and primary cells. By co-packaging pairs of ZFN proteins with donor RNA in 'all-in-one' lentiviral particles, we co-deliver ZFN proteins and the donor template for homology-directed repair leading to targeted DNA insertion and gene correction. Comparative studies of ZFN activity in a predetermined target locus and a known nearby off-target locus demonstrate reduced off-target activity after ZFN protein transduction relative to conventional delivery approaches. Additionally, TALEN proteins are added to the repertoire of custom-designed nucleases that can be delivered by protein transduction. Altogether, our findings generate a new platform for genome engineering based on efficient and potentially safer delivery of programmable nucleases.DOI: http://dx.doi.org/10.7554/eLife.01911.001. Copyright © 2014, Cai et al.

Hybrid Lentivirus-transposon Vectors With a Random Integration Profile in Human Cells

DEFF Research Database (Denmark)

Staunstrup, Nicklas H; Moldt, Brian; Mátés, Lajos

2009-01-01

Gene delivery by human immunodeficiency virus type 1 (HIV-1)-based lentiviral vectors (LVs) is efficient, but genomic integration of the viral DNA is strongly biased toward transcriptionally active loci resulting in an increased risk of insertional mutagenesis in gene therapy protocols. Nonviral...... Sleeping Beauty (SB) transposon vectors have a significantly safer insertion profile, but efficient delivery into relevant cell/tissue types is a limitation. In an attempt to combine the favorable features of the two vector systems we established a novel hybrid vector technology based on SB transposase......-mediated insertion of lentiviral DNA circles generated during transduction of target cells with integrase (IN)-defective LVs (IDLVs). By construction of a lentivirus-transposon hybrid vector allowing transposition exclusively from circular viral DNA substrates, we demonstrate that SB transposase added in trans...

Current strides in AAV-derived vectors and SIN channels further ...

African Journals Online (AJOL)

A.S. Odiba

restored, hematopoietic stem cells has been used to terminate incurable blood ... gene and cell therapy approach are founded on either ex vivo gene incorporation into ..... generating integration-deficient lentiviral vectors (IDLV), which on.

Characterization of complete particles (VSV-G/SIN-GFP) and empty particles (VSV-G/EMPTY) in human immunodeficiency virus type 1-based lentiviral products for gene therapy: potential applications for improvement of product quality and safety.

Science.gov (United States)

Zhao, Yuan; Keating, Kenneth; Dolman, Carl; Thorpe, Robin

2008-05-01

Lentiviral vectors persist in the host and are therefore ideally suited for long-term gene therapy. To advance the use of lentiviral vectors in humans, improvement of their production, purification, and characterization has become increasingly important and challenging. In addition to cellular contaminants derived from packaging cells, empty particles without therapeutic function are the major impurities that compromise product safety and efficacy. Removal of empty particles is difficult because of their innate similarity in particle size and protein composition to the complete particles. We propose that comparison of the properties of lentiviral products with those of purposely expressed empty particles may reveal potential differences between empty and complete particles. For this, three forms of recombinant lentiviral samples, that is, recombinant vesicular stomatitis virus glycoprotein (VSV-G) proteins, empty particles (VSV-G/Empty), and complete particles (VSV-G/SIN-GFP) carrying viral RNA, were purified by size-exclusion chromatography (SEC). The SEC-purified samples were further analyzed by immunoblotting with six antibodies to examine viral and cellular proteins associated with the particles. This study has demonstrated, for the first time, important differences between VSV-G/Empty particles and complete VSV-G/SIN-GFP particles. Differences include the processing of Gag protein and the inclusion of cellular proteins in the particles. Our findings support the development of improved production, purification, and characterization methods for lentiviral products.

A multicolor panel of TALE-KRAB based transcriptional repressor vectors enabling knockdown of multiple gene targets.

Science.gov (United States)

Zhang, Zhonghui; Wu, Elise; Qian, Zhijian; Wu, Wen-Shu

2014-12-05

Stable and efficient knockdown of multiple gene targets is highly desirable for dissection of molecular pathways. Because it allows sequence-specific DNA binding, transcription activator-like effector (TALE) offers a new genetic perturbation technique that allows for gene-specific repression. Here, we constructed a multicolor lentiviral TALE-Kruppel-associated box (KRAB) expression vector platform that enables knockdown of multiple gene targets. This platform is fully compatible with the Golden Gate TALEN and TAL Effector Kit 2.0, a widely used and efficient method for TALE assembly. We showed that this multicolor TALE-KRAB vector system when combined together with bone marrow transplantation could quickly knock down c-kit and PU.1 genes in hematopoietic stem and progenitor cells of recipient mice. Furthermore, our data demonstrated that this platform simultaneously knocked down both c-Kit and PU.1 genes in the same primary cell populations. Together, our results suggest that this multicolor TALE-KRAB vector platform is a promising and versatile tool for knockdown of multiple gene targets and could greatly facilitate dissection of molecular pathways.

Inhibition of experimental lung metastasis by systemic lentiviral delivery of kallistatin

International Nuclear Information System (INIS)

Shiau, Ai-Li; Wu, Chao-Liang; Lee, Che-Hsin; Teo, Min-Li; Chen, Shin-Yao; Wang, Chrong-Reen; Hsieh, Jeng-Long; Chang, Meng-Ya; Chang, Chih-Jui; Chao, Julie; Chao, Lee

2010-01-01

Angiogenesis plays an important role in the development and progression of tumors. Kallistatin exerts anti-angiogenic and anti-inflammatory activities that may be effective in inhibiting tumor metastasis. We investigated the antitumor effect of lentivirus-mediated kallistatin gene transfer in a syngeneic murine tumor model. Lentiviral vector encoding kallistatin (LV-Kallistatin) was constructed. The expression of kallistatin was verified by enzyme-linked immunosorbent assay (ELISA), and the bioactivity of kallistatin was determined by using cell proliferation, migration, and invasion assays. In addition, antitumor effects of LV-Kallistatin were evaluated by the intravenous injection of virus into tumor-bearing mice. The conditioned medium from LV-Kallistatin-treated cells inhibited the migration and proliferation of endothelial cells. Meanwhile, it also reduced the migration and invasion of tumor cells. In the experimental lung metastatic model, tumor-bearing mice receiving LV-Kallistatin had lower tumor nodules and longer survival than those receiving control virus or saline. Moreover, the microvessel densities, the levels of vascular endothelial growth factor (VEGF), tumor necrosis factor (TNF)-α, and nuclear factor κB (NF-κB) transcriptional activity were reduced in the LV-Kallistatin-treated mice. Results of this study showed that systemic administration of lentiviral vectors encoding kallistatin inhibited the growth of metastatic tumor and prolonged the survival of tumor-bearing mice. These results suggest that gene therapy using lentiviruses carrying the kallistatin gene, which exerts anti-angiogenic and anti-inflammatory activities, represents a promising strategy for the treatment of lung cancer

Phenotypic correction of Fanconi anemia cells in the murine bone marrow after carrier cell mediated delivery of lentiviral vector.

Science.gov (United States)

Chakkaramakkil Verghese, Santhosh; Goloviznina, Natalya A; Kurre, Peter

2016-11-19

Fanconi anemia (FA) is an autosomal-recessive disorder associated with hematopoietic failure and it is a candidate for hematopoietic stem cell (HSC)-directed gene therapy. However, the characteristically reduced HSC numbers found in FA patients, their ineffective mobilization from the marrow, and re-oxygenation damage during ex vivo manipulation have precluded clinical success using conventional in vitro approaches. We previously demonstrated that lentiviral vector (LV) particles reversibly attach to the cell surface where they gain protection from serum complement neutralization. We reasoned that cellular delivery of LV to the bone marrow niche could avoid detrimental losses during FA HSC mobilization and in vitro modification. Here, we demonstrate that a VSV-G pseudotyped lentivector, carrying the FANCC transgene, can be transmitted from carrier to bystander cells. In cell culture and transplantation models of FA, we further demonstrate that LV carrier cells migrate along SDF-1α gradients and transfer vector particles that stably integrate and phenotypically correct the characteristic DNA alkylator sensitivity in murine and human FA-deficient target bystander cells. Altogether, we demonstrate that cellular homing mechanisms can be harnessed for the functional phenotype correction in murine FA hematopoietic cells.

Phenotypic correction of Fanconi anemia cells in the murine bone marrow after carrier cell mediated delivery of lentiviral vector

Directory of Open Access Journals (Sweden)

Santhosh Chakkaramakkil Verghese

2016-11-01

Full Text Available Abstract Fanconi anemia (FA is an autosomal-recessive disorder associated with hematopoietic failure and it is a candidate for hematopoietic stem cell (HSC-directed gene therapy. However, the characteristically reduced HSC numbers found in FA patients, their ineffective mobilization from the marrow, and re-oxygenation damage during ex vivo manipulation have precluded clinical success using conventional in vitro approaches. We previously demonstrated that lentiviral vector (LV particles reversibly attach to the cell surface where they gain protection from serum complement neutralization. We reasoned that cellular delivery of LV to the bone marrow niche could avoid detrimental losses during FA HSC mobilization and in vitro modification. Here, we demonstrate that a VSV-G pseudotyped lentivector, carrying the FANCC transgene, can be transmitted from carrier to bystander cells. In cell culture and transplantation models of FA, we further demonstrate that LV carrier cells migrate along SDF-1α gradients and transfer vector particles that stably integrate and phenotypically correct the characteristic DNA alkylator sensitivity in murine and human FA-deficient target bystander cells. Altogether, we demonstrate that cellular homing mechanisms can be harnessed for the functional phenotype correction in murine FA hematopoietic cells.

Measles virus envelope pseudotyped lentiviral vectors transduce quiescent human HSCs at an efficiency without precedent.

Science.gov (United States)

Lévy, Camille; Amirache, Fouzia; Girard-Gagnepain, Anais; Frecha, Cecilia; Roman-Rodríguez, Francisco J; Bernadin, Ornellie; Costa, Caroline; Nègre, Didier; Gutierrez-Guerrero, Alejandra; Vranckx, Lenard S; Clerc, Isabelle; Taylor, Naomi; Thielecke, Lars; Cornils, Kerstin; Bueren, Juan A; Rio, Paula; Gijsbers, Rik; Cosset, François-Loïc; Verhoeyen, Els

2017-10-24

Hematopoietic stem cell (HSC)-based gene therapy trials are now moving toward the use of lentiviral vectors (LVs) with success. However, one challenge in the field remains: efficient transduction of HSCs without compromising their stem cell potential. Here we showed that measles virus glycoprotein-displaying LVs (hemagglutinin and fusion protein LVs [H/F-LVs]) were capable of transducing 100% of early-acting cytokine-stimulated human CD34 + (hCD34 + ) progenitor cells upon a single application. Strikingly, these H/F-LVs also allowed transduction of up to 70% of nonstimulated quiescent hCD34 + cells, whereas conventional vesicular stomatitis virus G (VSV-G)-LVs reached 5% at the most with H/F-LV entry occurring exclusively through the CD46 complement receptor. Importantly, reconstitution of NOD/SCIDγc -/- (NSG) mice with H/F-LV transduced prestimulated or resting hCD34 + cells confirmed these high transduction levels in all myeloid and lymphoid lineages. Remarkably, for resting CD34 + cells, secondary recipients exhibited increasing transduction levels of up to 100%, emphasizing that H/F-LVs efficiently gene-marked HSCs in the resting state. Because H/F-LVs promoted ex vivo gene modification of minimally manipulated CD34 + progenitors that maintained stemness, we assessed their applicability in Fanconi anemia, a bone marrow (BM) failure with chromosomal fragility. Notably, only H/F-LVs efficiently gene-corrected minimally stimulated hCD34 + cells in unfractionated BM from these patients. These H/F-LVs improved HSC gene delivery in the absence of cytokine stimulation while maintaining their stem cell potential. Thus, H/F-LVs will facilitate future clinical applications requiring HSC gene modification, including BM failure syndromes, for which treatment has been very challenging up to now.

Construction of lentiviral shRNA expression vector targeting ...

African Journals Online (AJOL)

ajl yemi

2011-10-26

Oct 26, 2011 ... was then selected, while the titer of lentiviral packing PLD2-shRNA was 3.47 × 104 TU/ml and the virus was successfully ... MATERIALS AND METHODS .... such as: transfecting cells not only in mitotic active phase but also in ...

Immune modulation by genetic modification of dendritic cells with lentiviral vectors.

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Liechtenstein, Therese; Perez-Janices, Noemi; Bricogne, Christopher; Lanna, Alessio; Dufait, Inès; Goyvaerts, Cleo; Laranga, Roberta; Padella, Antonella; Arce, Frederick; Baratchian, Mehdi; Ramirez, Natalia; Lopez, Natalia; Kochan, Grazyna; Blanco-Luquin, Idoia; Guerrero-Setas, David; Breckpot, Karine; Escors, David

2013-09-01

Our work over the past eight years has focused on the use of HIV-1 lentiviral vectors (lentivectors) for the genetic modification of dendritic cells (DCs) to control their functions in immune modulation. DCs are key professional antigen presenting cells which regulate the activity of most effector immune cells, including T, B and NK cells. Their genetic modification provides the means for the development of targeted therapies towards cancer and autoimmune disease. We have been modulating with lentivectors the activity of intracellular signalling pathways and co-stimulation during antigen presentation to T cells, to fine-tune the type and strength of the immune response. In the course of our research, we have found unexpected results such as the surprising immunosuppressive role of anti-viral signalling pathways, and the close link between negative co-stimulation in the immunological synapse and T cell receptor trafficking. Here we review our major findings and put them into context with other published work. Copyright © 2013 Elsevier B.V. All rights reserved.

Efficient delivery of Cre-recombinase to neurons in vivo and stable transduction of neurons using adeno-associated and lentiviral vectors

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Sablitzky Fred

2004-01-01

Full Text Available Abstract Background Inactivating genes in vivo is an important technique for establishing their function in the adult nervous system. Unfortunately, conventional knockout mice may suffer from several limitations including embryonic or perinatal lethality and the compensatory regulation of other genes. One approach to producing conditional activation or inactivation of genes involves the use of Cre recombinase to remove loxP-flanked segments of DNA. We have studied the effects of delivering Cre to the hippocampus and neocortex of adult mice by injecting replication-deficient adeno-associated virus (AAV and lentiviral (LV vectors into discrete regions of the forebrain. Results Recombinant AAV-Cre, AAV-GFP (green fluorescent protein and LV-Cre-EGFP (enhanced GFP were made with the transgene controlled by the cytomegalovirus promoter. Infecting 293T cells in vitro with AAV-Cre and LV-Cre-EGFP resulted in transduction of most cells as shown by GFP fluorescence and Cre immunoreactivity. Injections of submicrolitre quantities of LV-Cre-EGFP and mixtures of AAV-Cre with AAV-GFP into the neocortex and hippocampus of adult Rosa26 reporter mice resulted in strong Cre and GFP expression in the dentate gyrus and moderate to strong labelling in specific regions of the hippocampus and in the neocortex, mainly in neurons. The pattern of expression of Cre and GFP obtained with AAV and LV vectors was very similar. X-gal staining showed that Cre-mediated recombination had occurred in neurons in the same regions of the brain, starting at 3 days post-injection. No obvious toxic effects of Cre expression were detected even after four weeks post-injection. Conclusion AAV and LV vectors are capable of delivering Cre to neurons in discrete regions of the adult mouse brain and producing recombination.

Inhibition of HIV-1 lentiviral particles infectivity by Gynostemma ...

African Journals Online (AJOL)

These claims motivated the study in which the inhibition of viral vector infectivity of HeLa cells was assessed flow cytometrically by measuring the expression of green fluorescent protein (GFP) transgene incorporated in the lentiviral vector construct. An infectious VSV-G-pseudotyped, human immunodeficiency virus type ...

Inhibition of experimental lung metastasis by systemic lentiviral delivery of kallistatin

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Chao Julie

2010-05-01

Full Text Available Abstract Background Angiogenesis plays an important role in the development and progression of tumors. Kallistatin exerts anti-angiogenic and anti-inflammatory activities that may be effective in inhibiting tumor metastasis. We investigated the antitumor effect of lentivirus-mediated kallistatin gene transfer in a syngeneic murine tumor model. Methods Lentiviral vector encoding kallistatin (LV-Kallistatin was constructed. The expression of kallistatin was verified by enzyme-linked immunosorbent assay (ELISA, and the bioactivity of kallistatin was determined by using cell proliferation, migration, and invasion assays. In addition, antitumor effects of LV-Kallistatin were evaluated by the intravenous injection of virus into tumor-bearing mice. Results The conditioned medium from LV-Kallistatin-treated cells inhibited the migration and proliferation of endothelial cells. Meanwhile, it also reduced the migration and invasion of tumor cells. In the experimental lung metastatic model, tumor-bearing mice receiving LV-Kallistatin had lower tumor nodules and longer survival than those receiving control virus or saline. Moreover, the microvessel densities, the levels of vascular endothelial growth factor (VEGF, tumor necrosis factor (TNF-α, and nuclear factor κB (NF-κB transcriptional activity were reduced in the LV-Kallistatin-treated mice. Conclusion Results of this study showed that systemic administration of lentiviral vectors encoding kallistatin inhibited the growth of metastatic tumor and prolonged the survival of tumor-bearing mice. These results suggest that gene therapy using lentiviruses carrying the kallistatin gene, which exerts anti-angiogenic and anti-inflammatory activities, represents a promising strategy for the treatment of lung cancer.

Rapid lentiviral transduction preserves the engraftment potential of Fanca(-/-) hematopoietic stem cells.

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Müller, Lars U W; Milsom, Michael D; Kim, Mi-Ok; Schambach, Axel; Schuesler, Todd; Williams, David A

2008-06-01

Fanconi anemia (FA) is a rare recessive syndrome, characterized by congenital anomalies, bone marrow failure, and predisposition to cancer. Two earlier clinical trials utilizing gamma-retroviral vectors for the transduction of autologous FA hematopoietic stem cells (HSCs) required extensive in vitro manipulation and failed to achieve detectable long-term engraftment of transduced HSCs. As a strategy for minimizing ex vivo manipulation, we investigated the use of a "rapid" lentiviral transduction protocol in a murine Fanca(-/-) model. Importantly, while this and most murine models of FA fail to completely mimic the human hematopoietic phenotype, we observed a high incidence of HSC transplant engraftment failure and low donor chimerism after conventional transduction (CT) of Fanca(-/-) donor cells. In contrast, rapid transduction (RT) of Fanca(-/-) HSCs preserved engraftment to the level achieved in wild-type cells, resulting in long-term multilineage engraftment of gene-modified cells. We also demonstrate the correction of the characteristic hypersensitivity of FA cells against the cross-linking agent mitomycin C (MMC), and provide evidence for the advantage of using pharmacoselection as a means of further increasing gene-modified cells after RT. Collectively, these data support the use of rapid lentiviral transduction for gene therapy in FA.

Simplified lentivirus vector production in protein-free media using polyethylenimine-mediated transfection.

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Kuroda, Hitoshi; Kutner, Robert H; Bazan, Nicolas G; Reiser, Jakob

2009-05-01

During the past 12 years, lentiviral vectors have emerged as valuable tools for transgene delivery because of their ability to transduce nondividing cells and their capacity to sustain long-term transgene expression. Despite significant progress, the production of high-titer high-quality lentiviral vectors is cumbersome and costly. The most commonly used method to produce lentiviral vectors involves transient transfection using calcium phosphate (CaP)-mediated precipitation of plasmid DNAs. However, inconsistencies in pH can cause significant batch-to-batch variations in lentiviral vector titers, making this method unreliable. This study describes optimized protocols for lentiviral vector production based on polyethylenimine (PEI)-mediated transfection, resulting in more consistent lentiviral vector stocks. To achieve this goal, simple production methods for high-titer lentiviral vector production involving transfection of HEK 293T cells immediately after plating were developed. Importantly, high titers were obtained with cell culture media lacking serum or other protein additives altogether. As a consequence, large-scale lentiviral vector stocks can now be generated with fewer batch-to-batch variations and at reduced costs and with less labor compared to the standard protocols.

Genetic modification of hematopoietic cells using retroviral and lentiviral vectors: safety considerations for vector design and delivery into target cells.

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Dropulic, Boro

2005-07-01

The recent development of leukemia in three patients following retroviral vector gene transfer in hematopoietic stem cells, resulting in the death of one patient, has raised safety concerns for the use of integrating gene transfer vectors for human gene therapy. This review discusses these serious adverse events from the perspective of whether restrictions on vector design and vector-modified target cells are warranted at this time. A case is made against presently establishing specific restrictions for vector design and transduced cells; rather, their safety should be ascertained by empiric evaluation in appropriate preclinical models on a case-by-case basis. Such preclinical data, coupled with proper informed patient consent and a risk-benefit ratio analysis, provide the best available prospective evaluation of gene transfer vectors prior to their translation into the clinic.

Sindbis Virus-Pseudotyped Lentiviral Vectors Carrying VEGFR2-Specific Nanobody for Potential Transductional Targeting of Tumor Vasculature.

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Ahani, Roshank; Roohvand, Farzin; Cohan, Reza Ahangari; Etemadzadeh, Mohammad Hossein; Mohajel, Nasir; Behdani, Mahdi; Shahosseini, Zahra; Madani, Navid; Azadmanesh, Kayhan

2016-11-01

Introduction of selectivity/specificity into viral-based gene delivery systems, such as lentiviral vectors (LVs), is crucial in their systemic administration for cancer gene therapy. The pivotal role of tumor-associated endothelial cells (TAECs) in tumor angiogenesis and overexpression of vascular endothelial growth factor receptor-2 (VEGFR2 or KDR) in TAECs makes them a potent target in cancer treatment. Herein, we report the development of VEGFR2-targeted LVs pseudotyped with chimeric sindbis virus E2 glycoprotein (cSVE2s). For this purpose, either sequence of a VEGFR2-specific nanobody or its natural ligand (VEGF 121 ) was inserted into the binding site of sindbis virus E2 glycoprotein. In silico modeling data suggested that the inserted targeting motifs were exposed in the context of cSVE2s. Western blot analysis of LVs indicated the incorporation of cSVE2s into viral particles. Capture ELISA demonstrated the specificity/functionality of the incorporated cSVE2s. Transduction of 293/KDR (expressing VEGFR2) or 293T cells (negative control) by constructed LVs followed by fluorescent microscopy and flow cytometric analyses indicated selective transduction of 293/KDR cells (30 %) by both targeting motifs compared to 293T control cells (1-2 %). These results implied similar targeting properties of VEGFR2-specific nanobody compared to the VEGF 121 and indicated the potential for transductional targeting of tumor vasculature by the nanobody displaying LVs.

Antibody-directed lentiviral gene transduction for live-cell monitoring and selection of human iPS and hES cells.

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Dai-tze Wu

Full Text Available The identification of stem cells within a mixed population of cells is a major hurdle for stem cell biology--in particular, in the identification of induced pluripotent stem (iPS cells during the reprogramming process. Based on the selective expression of stem cell surface markers, a method to specifically infect stem cells through antibody-conjugated lentiviral particles has been developed that can deliver both visual markers for live-cell imaging as well as selectable markers to enrich for iPS cells. Antibodies recognizing SSEA4 and CD24 mediated the selective infection of the iPS cells over the parental human fibroblasts, allowing for rapid expansion of these cells by puromycin selection. Adaptation of the vector allows for the selective marking of human embryonic stem (hES cells for their removal from a population of differentiated cells. This method has the benefit that it not only identifies stem cells, but that specific genes, including positive and negative selection markers, regulatory genes or miRNA can be delivered to the targeted stem cells. The ability to specifically target gene delivery to human pluripotent stem cells has broad applications in tissue engineering and stem cell therapies.

[Construction and expression of recombinant lentiviral vectors of AKT2,PDK1 and BAD].

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Zhu, Jing; Chen, Bo-Jiang; Huang, Na; Li, Wei-Min

2014-03-01

To construct human protein kinase B (ATK2), phosphoinositide-dependent kinase 1 (PDK1) and bcl-2-associated death protein (BAD) lentiviral expression vector, and to determine their expressions in 293T cells. Total RNA was extracted from lung cancer tissues. The full-length coding regions of human ATK2, BAD and PDK1 cDNA were amplified via RT-PCR using specific primers, subcloned into PGEM-Teasy and then sequenced for confirmation. The full-length coding sequence was cut out with a specific restriction enzyme digest and subclone into pCDF1-MCS2-EF1-copGFP. The plasmids were transfected into 293T cells using the calcium phosphate method. The over expression of AKT2, BAD and PDK1 were detected by Western blot. AKT2, PDK1 and BAD were subcloned into pCDF1-MCS2-EF1-copGFP, with an efficiency of transfection of 100%, 95%, and 90% respectively. The virus titers were 6.7 x 10(6) PFU/mL in the supernatant. After infection, the proteins of AKT2, PDK1 and BAD were detected by Western blot. The lentivial vector pCDF1-MCS2-EF1-copGFP containing AKT2, BAD and PDK1 were successfully constructed and expressed in 293T cells.

Simplified production and concentration of HIV-1-based lentiviral vectors using HYPERFlask vessels and anion exchange membrane chromatography

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Kutner, Robert H; Puthli, Sharon; Marino, Michael P; Reiser, Jakob

2009-01-01

Background During the past twelve years, lentiviral (LV) vectors have emerged as valuable tools for transgene delivery because of their ability to transduce nondividing cells and their capacity to sustain long-term transgene expression in target cells in vitro and in vivo. However, despite significant progress, the production and concentration of high-titer, high-quality LV vector stocks is still cumbersome and costly. Methods Here we present a simplified protocol for LV vector production on a laboratory scale using HYPERFlask vessels. HYPERFlask vessels are high-yield, high-performance flasks that utilize a multilayered gas permeable growth surface for efficient gas exchange, allowing convenient production of high-titer LV vectors. For subsequent concentration of LV vector stocks produced in this way, we describe a facile protocol involving Mustang Q anion exchange membrane chromatography. Results Our results show that unconcentrated LV vector stocks with titers in excess of 108 transduction units (TU) per ml were obtained using HYPERFlasks and that these titers were higher than those produced in parallel using regular 150-cm2 tissue culture dishes. We also show that up to 500 ml of an unconcentrated LV vector stock prepared using a HYPERFlask vessel could be concentrated using a single Mustang Q Acrodisc with a membrane volume of 0.18 ml. Up to 5.3 × 1010 TU were recovered from a single HYPERFlask vessel. Conclusion The protocol described here is easy to implement and should facilitate high-titer LV vector production for preclinical studies in animal models without the need for multiple tissue culture dishes and ultracentrifugation-based concentration protocols. PMID:19220915

Stable lentiviral transformation of CHO cells for the expression of the hemagglutinin H5 of avian influenza virus in suspension culture

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Alaín González Pose

2014-09-01

Full Text Available Avian influenza virus H5N1 has caused extensive damage worldwide among poultry and humans. Effective expression systems are needed for the production of viral proteins required for monitoring this devastating disease. The present study deals with the establishment of a stable expression system for the hemagglutinin H5 (HAH5 of avian influenza virus using CHO cells in suspension culture transduced with a recombinant lentiviral vector. The synthetic gene coding the HAH5 protein was inserted in a lentiviral vector with the aim of performing a stable transduction of CHO cells. After the selection of recombinant clones, the one with the highest expression level was adapted to suspension culture and the HAH5 protein was purified by immunoaffinity chromatography from the culture supernatant. There were no significant differences when this protein, purified or direct from the culture supernatant of CHO or SiHa cells, was utilized in an immunologic assay using positive and negative sera as reference. It was also demonstrated that the HAH5 protein in its purified form is able to bind anti-HAH5 antibodies generated with proper and non-proper folded proteins. The results demonstrate that the CHO cell line stably transduced with a lentiviral vector coding the sequence of the HAH5 protein and cultured in suspension can be a suitable expression system to obtain this protein for diagnostic purpose in a consistent and reliable manner.

Efficient in vivo gene transfer to xenotransplanted human skin by lentivirus-mediated, but not by AAV-directed, gene delivery

DEFF Research Database (Denmark)

Jakobsen, Maria Vad; Askou, Anne Louise; Dokkedahl, Karin Stenderup

skin graft, and firefly luciferase expression was observed primarily in neighboring tissue beneath or surrounding the graft. In contrast, gene delivery by intradermally injected lentiviral vectors was efficient and led to extensive and persistent firefly luciferase expression within the human skin...... graft only. The study demonstrates limited capacity of single-stranded AAV vectors of six commonly used serotypes for gene delivery to human skin in vivo....

Latent Membrane Protein 1 as a molecular adjuvant for single-cycle lentiviral vaccines

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Rahmberg Andrew R

2011-05-01

Full Text Available Abstract Background Molecular adjuvants are a promising method to enhance virus-specific immune responses and protect against HIV-1 infection. Immune activation by ligands for receptors such as CD40 can induce dendritic cell activation and maturation. Here we explore the incorporation of two CD40 mimics, Epstein Barr Virus gene LMP1 or an LMP1-CD40 chimera, into a strain of SIV that was engineered to be limited to a single cycle of infection. Results Full length LMP1 or the chimeric protein LMP1-CD40 was cloned into the nef-locus of single-cycle SIV. Human and Macaque monocyte derived macrophages and DC were infected with these viruses. Infected cells were analyzed for activation surface markers by flow cytometry. Cells were also analyzed for secretion of pro-inflammatory cytokines IL-1β, IL-6, IL-8, IL-12p70 and TNF by cytometric bead array. Conclusions Overall, single-cycle SIV expressing LMP1 and LMP1-CD40 produced a broad and potent TH1-biased immune response in human as well as rhesus macaque macrophages and DC when compared with control virus. Single-cycle SIV-LMP1 also enhanced antigen presentation by lentiviral vector vaccines, suggesting that LMP1-mediated immune activation may enhance lentiviral vector vaccines against HIV-1.

Gene therapy for Stargardt disease associated with ABCA4 gene.

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Han, Zongchao; Conley, Shannon M; Naash, Muna I

2014-01-01

Mutations in the photoreceptor-specific flippase ABCA4 lead to accumulation of the toxic bisretinoid A2E, resulting in atrophy of the retinal pigment epithelium (RPE) and death of the photoreceptor cells. Many blinding diseases are associated with these mutations including Stargardt's disease (STGD1), cone-rod dystrophy, retinitis pigmentosa (RP), and increased susceptibility to age-related macular degeneration. There are no curative treatments for any of these dsystrophies. While the monogenic nature of many of these conditions makes them amenable to treatment with gene therapy, the ABCA4 cDNA is 6.8 kb and is thus too large for the AAV vectors which have been most successful for other ocular genes. Here we review approaches to ABCA4 gene therapy including treatment with novel AAV vectors, lentiviral vectors, and non-viral compacted DNA nanoparticles. Lentiviral and compacted DNA nanoparticles in particular have a large capacity and have been successful in improving disease phenotypes in the Abca4 (-/-) murine model. Excitingly, two Phase I/IIa clinical trials are underway to treat patients with ABCA4-associated Startgardt's disease (STGD1). As a result of the development of these novel technologies, effective therapies for ABCA4-associated diseases may finally be within reach.

In Vivo Knockout of the Vegfa Gene by Lentiviral Delivery of CRISPR/Cas9 in Mouse Retinal Pigment Epithelium Cells

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Andreas Holmgaard

2017-12-01

Full Text Available Virus-based gene therapy by CRISPR/Cas9-mediated genome editing and knockout may provide a new option for treatment of inherited and acquired ocular diseases of the retina. In support of this notion, we show that Streptococcus pyogenes (Sp Cas9, delivered by lentiviral vectors (LVs, can be used in vivo to selectively ablate the vascular endothelial growth factor A (Vegfa gene in mice. By generating LVs encoding SpCas9 targeted to Vegfa, and in parallel the fluorescent eGFP marker protein, we demonstrate robust knockout of Vegfa that leads to a significant reduction of VEGFA protein in transduced cells. Three of the designed single-guide RNAs (sgRNAs induce in vitro indel formation at high frequencies (44%–93%. A single unilateral subretinal injection facilitates RPE-specific localization of the vector and disruption of Vegfa in isolated eGFP+ RPE cells obtained from mice five weeks after LV administration. Notably, sgRNA delivery results in the disruption of Vegfa with an in vivo indel formation efficacy of up to 84%. Sequencing of Vegfa-specific amplicons reveals formation of indels, including 4-bp deletions and 2-bp insertions. Taken together, our data demonstrate the capacity of lentivirus-delivered SpCas9 and sgRNAs as a developing therapeutic path in the treatment of ocular diseases, including age-related macular degeneration.

An optimized lentiviral vector system for conditional RNAi and efficient cloning of microRNA embedded short hairpin RNA libraries.

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Adams, Felix F; Heckl, Dirk; Hoffmann, Thomas; Talbot, Steven R; Kloos, Arnold; Thol, Felicitas; Heuser, Michael; Zuber, Johannes; Schambach, Axel; Schwarzer, Adrian

2017-09-01

RNA interference (RNAi) and CRISPR-Cas9-based screening systems have emerged as powerful and complementary tools to unravel genetic dependencies through systematic gain- and loss-of-function studies. In recent years, a series of technical advances helped to enhance the performance of virally delivered RNAi. For instance, the incorporation of short hairpin RNAs (shRNAs) into endogenous microRNA contexts (shRNAmiRs) allows the use of Tet-regulated promoters for synchronous onset of gene knockdown and precise interrogation of gene dosage effects. However, remaining challenges include lack of efficient cloning strategies, inconsistent knockdown potencies and leaky expression. Here, we present a simple, one-step cloning approach for rapid and efficient cloning of miR-30 shRNAmiR libraries. We combined a human miR-30 backbone retaining native flanking sequences with an optimized all-in-one lentiviral vector system for conditional RNAi to generate a versatile toolbox characterized by higher doxycycline sensitivity, reduced leakiness and enhanced titer. Furthermore, refinement of existing shRNA design rules resulted in substantially improved prediction of powerful shRNAs. Our approach was validated by accurate quantification of the knockdown potency of over 250 single shRNAmiRs. To facilitate access and use by the scientific community, an online tool was developed for the automated design of refined shRNA-coding oligonucleotides ready for cloning into our system. Copyright © 2017 Elsevier Ltd. All rights reserved.

Preclinical safety and efficacy of an anti–HIV-1 lentiviral vector containing a short hairpin RNA to CCR5 and the C46 fusion inhibitor

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Orit Wolstein

2014-01-01

Full Text Available Gene transfer has therapeutic potential for treating HIV-1 infection by generating cells that are resistant to the virus. We have engineered a novel self-inactivating lentiviral vector, LVsh5/C46, using two viral-entry inhibitors to block early steps of HIV-1 cycle. The LVsh5/C46 vector encodes a short hairpin RNA (shRNA for downregulation of CCR5, in combination with the HIV-1 fusion inhibitor, C46. We demonstrate here the effective delivery of LVsh5/C46 to human T cell lines, peripheral blood mononuclear cells, primary CD4+ T lymphocytes, and CD34+ hematopoietic stem/progenitor cells (HSPC. CCR5-targeted shRNA (sh5 and C46 peptide were stably expressed in the target cells and were able to effectively protect gene-modified cells against infection with CCR5- and CXCR4-tropic strains of HIV-1. LVsh5/C46 treatment was nontoxic as assessed by cell growth and viability, was noninflammatory, and had no adverse effect on HSPC differentiation. LVsh5/C46 could be produced at a scale sufficient for clinical development and resulted in active viral particles with very low mutagenic potential and the absence of replication-competent lentivirus. Based on these in vitro results, plus additional in vivo safety and efficacy data, LVsh5/C46 is now being tested in a phase 1/2 clinical trial for the treatment of HIV-1 disease.

Lentiviral vectors in neurodegenrative disorders - Aspects in gene therapy and disease models

DEFF Research Database (Denmark)

Nielsen, Troels Tolstrup

2009-01-01

Neurodegenerative disorders remain a complex group of diseases (i.e. Huntington's disease, HD) that are characterized by progressive loss of neurons resulting in movement disorders, cognitive decline, dementia and death. There is no cure for these diseases and treatment relies on symptomatic relief...... expression and escape transgene silencing during differentiation of neural stem cell lines. However, insulator vectors appeared to be impaired in functionality, which has importance for the future use of insulators in viral vectors. Finally, cell based models of HD was constructed to elucidate...

Differentiated neuroprogenitor cells incubated with human or canine adenovirus, or lentiviral vectors have distinct transcriptome profiles.

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Stefania Piersanti

Full Text Available Several studies have demonstrated the potential for vector-mediated gene transfer to the brain. Helper-dependent (HD human (HAd and canine (CAV-2 adenovirus, and VSV-G-pseudotyped self-inactivating HIV-1 vectors (LV effectively transduce human brain cells and their toxicity has been partly analysed. However, their effect on the brain homeostasis is far from fully defined, especially because of the complexity of the central nervous system (CNS. With the goal of dissecting the toxicogenomic signatures of the three vectors for human neurons, we transduced a bona fide human neuronal system with HD-HAd, HD-CAV-2 and LV. We analysed the transcriptional response of more than 47,000 transcripts using gene chips. Chip data showed that HD-CAV-2 and LV vectors activated the innate arm of the immune response, including Toll-like receptors and hyaluronan circuits. LV vector also induced an IFN response. Moreover, HD-CAV-2 and LV vectors affected DNA damage pathways--but in opposite directions--suggesting a differential response of the p53 and ATM pathways to the vector genomes. As a general response to the vectors, human neurons activated pro-survival genes and neuron morphogenesis, presumably with the goal of re-establishing homeostasis. These data are complementary to in vivo studies on brain vector toxicity and allow a better understanding of the impact of viral vectors on human neurons, and mechanistic approaches to improve the therapeutic impact of brain-directed gene transfer.

Comparison Between Several Integrase-defective Lentiviral Vectors Reveals Increased Integration of an HIV Vector Bearing a D167H Mutant

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Muhammad Qamar Saeed

2014-01-01

Full Text Available HIV-1 derived vectors are among the most efficient for gene transduction in mammalian tissues. As the parent virus, they carry out vector genome insertion into the host cell chromatin. Consequently, their preferential integration in transcribed genes raises several conceptual and safety issues. To address part of these questions, HIV-derived vectors have been engineered to be nonintegrating. This was mainly achieved by mutating HIV-1 integrase at functional hotspots of the enzyme enabling the development of streamlined nuclear DNA circles functional for transgene expression. Few integrase mutant vectors have been successfully tested so far for gene transfer. They are cleared with time in mitotic cells, but stable within nondividing retina cells or neurons. Here, we compared six HIV vectors carrying different integrases, either wild type or with different mutations (D64V, D167H, Q168A, K186Q+Q214L+Q216L, and RRK262-264AAH shown to modify integrase enzymatic activity, oligomerization, or interaction with key cellular cofactor of HIV DNA integration as LEDGF/p75 or TNPO3. We show that these mutations differently affect the transduction efficiency as well as rates and patterns of integration of HIV-derived vectors suggesting their different processing in the nucleus. Surprisingly and most interestingly, we report that an integrase carrying the D167H substitution improves vector transduction efficiency and integration in both HEK-293T and primary CD34+ cells.

In vivo knockdown of antisense non-coding mitochondrial RNAs by a lentiviral-encoded shRNA inhibits melanoma tumor growth and lung colonization.

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Varas-Godoy, Manuel; Lladser, Alvaro; Farfan, Nicole; Villota, Claudio; Villegas, Jaime; Tapia, Julio C; Burzio, Luis O; Burzio, Veronica A; Valenzuela, Pablo D T

2018-01-01

The family of non-coding mitochondrial RNAs (ncmtRNA) is differentially expressed according to proliferative status. Normal proliferating cells express sense (SncmtRNA) and antisense ncmtRNAs (ASncmtRNAs), whereas tumor cells express SncmtRNA and downregulate ASncmtRNAs. Knockdown of ASncmtRNAs with oligonucleotides induces apoptotic cell death of tumor cells, leaving normal cells unaffected, suggesting a potential application for developing a novel cancer therapy. In this study, we knocked down the ASncmtRNAs in melanoma cell lines with a lentiviral-encoded shRNA approach. Transduction with lentiviral constructs targeted to the ASncmtRNAs induced apoptosis in murine B16F10 and human A375 melanoma cells in vitro and significantly retarded B16F10 primary tumor growth in vivo. Moreover, the treatment drastically reduced the number of lung metastatic foci in a tail vein injection assay, compared to controls. These results provide additional proof of concept to the knockdown of ncmtRNAs for cancer therapy and validate lentiviral-shRNA vectors for gene therapy. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Efficient biotechnological approach for lentiviral transduction of induced pluripotent stem cells.

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Zare, Mehrak; Soleimani, Masoud; Mohammadian, Mozhdeh; Akbarzadeh, Abolfazl; Havasi, Parvaneh; Zarghami, Nosratollah

2016-01-01

Induced pluripotent stem (iPS) cells are generated from differentiated adult somatic cells by reprogramming them. Unlimited self-renewal, and the potential to differentiate into any cell type, make iPS cells very promising candidates for basic and clinical research. Furthermore, iPS cells can be genetically manipulated for use as therapeutic tools. DNA can be introduced into iPS cells, using lentiviral vectors, which represent a helpful choice for efficient transduction and stable integration of transgenes. In this study, we compare two methods of lentiviral transduction of iPS cells, namely, the suspension method and the hanging drop method. In contrast to the conventional suspension method, in the hanging drop method, embryoid body (EB) formation and transduction occur concurrently. The iPS cells were cultured to form EBs, and then transduced with lentiviruses, using the conventional suspension method and the hanging drop method, to express miR-128 and green fluorescent protein (GFP). The number of transduced cells were assessed by fluorescent microscopy and flow cytometry. MTT assay and real-time PCR were performed to determine the cell viability and transgene expression, respectively. Morphologically, GFP+ cells were more detectable in the hanging drop method, and this finding was quantified by flow cytometric analysis. According to the results of the MTT assay, cell viability was considerably higher in the hanging drop method, and real-time PCR represented a higher relative expression of miR-128 in the iPS cells introduced with lentiviruses in drops. Altogether, it seems that lentiviral transduction of challenging iPS cells using the hanging drop method offers a suitable and sufficient strategy in their gene transfer, with less toxicity than the conventional suspension method.

Historical Perspective on the Current Renaissance for Hematopoietic Stem Cell Gene Therapy.

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Kohn, Donald B

2017-10-01

Gene therapy using hematopoietic stem cells (HSC) has developed over the past 3 decades, with progressive improvements in the efficacy and safety. Autologous transplantation of HSC modified with murine gammaretroviral vectors first showed clinical benefits for patients with several primary immune deficiencies, but some of these patients suffered complications from vector-related genotoxicity. Lentiviral vectors have been used recently for gene addition to HSC and have yielded clinical benefits for primary immune deficiencies, metabolic diseases, and hemoglobinopathies, without vector-related complications. Gene editing using site-specific endonucleases is emerging as a promising technology for gene therapy and is moving into clinical trials. Copyright © 2017 Elsevier Inc. All rights reserved.

New World feline APOBEC3 potently controls inter-genus lentiviral transmission.

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Konno, Yoriyuki; Nagaoka, Shumpei; Kimura, Izumi; Yamamoto, Keisuke; Kagawa, Yumiko; Kumata, Ryuichi; Aso, Hirofumi; Ueda, Mahoko Takahashi; Nakagawa, So; Kobayashi, Tomoko; Koyanagi, Yoshio; Sato, Kei

2018-04-10

The apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3 (APOBEC3; A3) gene family appears only in mammalian genomes. Some A3 proteins can be incorporated into progeny virions and inhibit lentiviral replication. In turn, the lentiviral viral infectivity factor (Vif) counteracts the A3-mediated antiviral effect by degrading A3 proteins. Recent investigations have suggested that lentiviral vif genes evolved to combat mammalian APOBEC3 proteins, and have further proposed that the Vif-A3 interaction may help determine the co-evolutionary history of cross-species lentiviral transmission in mammals. Here we address the co-evolutionary relationship between two New World felids, the puma (Puma concolor) and the bobcat (Lynx rufus), and their lentiviruses, which are designated puma lentiviruses (PLVs). We demonstrate that PLV-A Vif counteracts the antiviral action of APOBEC3Z3 (A3Z3) of both puma and bobcat, whereas PLV-B Vif counteracts only puma A3Z3. The species specificity of PLV-B Vif is irrespective of the phylogenic relationships of feline species in the genera Puma, Lynx and Acinonyx. We reveal that the amino acid at position 178 in the puma and bobcat A3Z3 is exposed on the protein surface and determines the sensitivity to PLV-B Vif-mediated degradation. Moreover, although both the puma and bobcat A3Z3 genes are polymorphic, their sensitivity/resistance to PLV Vif-mediated degradation is conserved. To the best of our knowledge, this is the first study suggesting that the host A3 protein potently controls inter-genus lentiviral transmission. Our findings provide the first evidence suggesting that the co-evolutionary arms race between lentiviruses and mammals has occurred in the New World.

[Knockdown of dopamine receptor D2 upregulates the expression of adiogenic genes in mouse primary mesencephalic neurons].

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Ding, Jiaqi; Chen, Xiaoli; Lin, Jiaji; Zhu, Junling; Li, Zhuyi

2018-01-01

Objective To study the effects of dopamine receptor D2 (DRD2) on the adipogenesis genes in mouse primary mesencephalic neurons. Methods The lentiviral vectors which expressed specific shRNA targeting DRD2 were constructed to decrease DRD2 expression in mouse primary mesencephalic neurons. High throughput sequencing (HTS) analysis was used to investigate gene expression changes between the DRD2 knock-down group and the negative control group. Real-time quantitative PCR (qRT-PCR) and Western blot analysis were applied to verify the differently expressed genes. Fatty acids were measured by fatty acid detection kit. Results DRD2 expression was effectively down-regulated in mouse primary mesencephalic neurons by lentiviral vectors. HTS revealed adipogenesis genes were significantly up-regulated after DRD2 down-regulation, mainly including delta(14)-sterol reductase, acetyl-coenzyme A synthetase, insulin-induced gene 1 protein and especially stearoyl-coenzyme A desaturase 1 (SCD1, 4-fold upregulated). The qRT-PCR and Western blot analysis verified that SCD1 was upregulated 2.6 folds and 2 folds respectively by lentiviral DRD2-shRNA vectors. Moreover, the SCD1-related free fatty acids were significantly more increased than the negative control group. Conclusion DRD2 in primary mesencephalic neurons had a significant regulative effect on the adipogenesis genes. The up-regulation of SCD1 can accelerate the conversion of saturated fatty acids to monounsaturated fatty acids and prevent the damage of lipid toxicity to cells.

Lentiviral vectors containing mouse Csf1r control elements direct macrophage-restricted expression in multiple species of birds and mammals

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Clare Pridans

2014-01-01

Full Text Available The development of macrophages requires signaling through the lineage-restricted receptor Csf1r. Macrophage-restricted expression of transgenic reporters based upon Csf1r requires the highly conserved Fms-intronic regulatory element (FIRE. We have created a lentiviral construct containing mouse FIRE and promoter. The lentivirus is capable of directing macrophage-restricted reporter gene expression in mouse, rat, human, pig, cow, sheep, and even chicken. Rat bone marrow cells transduced with the lentivirus were capable of differentiating into macrophages expressing the reporter gene in vitro. Macrophage-restricted expression may be desirable for immunization or immune response modulation, and for gene therapy for lysosomal storage diseases and some immunodeficiencies. The small size of the Csf1r transcription control elements will allow the insertion of large “cargo” for applications in gene therapy and vaccine delivery.

Genetic modification of lymphocytes by retrovirus-based vectors.

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Suerth, Julia D; Schambach, Axel; Baum, Christopher

2012-10-01

The genetic modification of lymphocytes is an important topic in the emerging field of gene therapy. Many clinical trials targeting immunodeficiency syndromes or cancer have shown therapeutic benefit; further applications address inflammatory and infectious disorders. Retroviral vector development requires a detailed understanding of the interactions with the host. Most researchers have used simple gammaretroviral vectors to modify lymphocytes, either directly or via hematopoietic stem and progenitor cells. Lentiviral, spumaviral (foamyviral) and alpharetroviral vectors were designed to reduce the necessity for cell stimulation and to utilize potentially safer integration properties. Novel surface modifications (pseudotyping) and transgenes, built using synthetic components, expand the retroviral toolbox, altogether promising increased specificity and potency. Product consistency will be an important criterion for routine clinical use. Copyright © 2012. Published by Elsevier Ltd.

Lentiviral-mediated transfer of CDNF promotes nerve regeneration and functional recovery after sciatic nerve injury in adult rats

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Cheng, Lei; Liu, Yi; Zhao, Hua; Zhang, Wen; Guo, Ying-Jun; Nie, Lin, E-mail: chengleiyx@126.com

2013-10-18

Highlights: •CDNF was successfully transfected by a lentiviral vector into the distal sciatic nerve. •CDNF improved S-100, NF200 expression and nerve regeneration after sciatic injury. •CDNF improved the remyelination and thickness of the regenerated sciatic nerve. •CDNF improved gastrocnemius muscle weight and sciatic functional recovery. -- Abstract: Peripheral nerve injury is often followed by incomplete and unsatisfactory functional recovery and may be associated with sensory and motor impairment of the affected limb. Therefore, a novel method is needed to improve the speed of recovery and the final functional outcome after peripheral nerve injuries. This report investigates the effect of lentiviral-mediated transfer of conserved dopamine neurotrophic factor (CDNF) on regeneration of the rat peripheral nerve in a transection model in vivo. We observed notable overexpression of CDNF protein in the distal sciatic nerve after recombinant CDNF lentiviral vector application. We evaluated sciatic nerve regeneration after surgery using light and electron microscopy and the functional recovery using the sciatic functional index and target muscle weight. HE staining revealed better ordered structured in the CDNF-treated group at 8 weeks post-surgery. Quantitative analysis of immunohistochemistry of NF200 and S-100 in the CDNF group revealed significant improvement of axonal and Schwann cell regeneration compared with the control groups at 4 weeks and 8 weeks after injury. The thickness of the myelination around the axons in the CDNF group was significantly higher than in the control groups at 8 weeks post-surgery. The CDNF group displayed higher muscle weights and significantly increased sciatic nerve index values. Our findings suggest that CDNF gene therapy could provide durable and stable CDNF protein concentration and has the potential to enhance peripheral nerve regeneration, morphological and functional recovery following nerve injury, which suggests a

Lentiviral-mediated transfer of CDNF promotes nerve regeneration and functional recovery after sciatic nerve injury in adult rats

International Nuclear Information System (INIS)

Cheng, Lei; Liu, Yi; Zhao, Hua; Zhang, Wen; Guo, Ying-Jun; Nie, Lin

2013-01-01

Highlights: •CDNF was successfully transfected by a lentiviral vector into the distal sciatic nerve. •CDNF improved S-100, NF200 expression and nerve regeneration after sciatic injury. •CDNF improved the remyelination and thickness of the regenerated sciatic nerve. •CDNF improved gastrocnemius muscle weight and sciatic functional recovery. -- Abstract: Peripheral nerve injury is often followed by incomplete and unsatisfactory functional recovery and may be associated with sensory and motor impairment of the affected limb. Therefore, a novel method is needed to improve the speed of recovery and the final functional outcome after peripheral nerve injuries. This report investigates the effect of lentiviral-mediated transfer of conserved dopamine neurotrophic factor (CDNF) on regeneration of the rat peripheral nerve in a transection model in vivo. We observed notable overexpression of CDNF protein in the distal sciatic nerve after recombinant CDNF lentiviral vector application. We evaluated sciatic nerve regeneration after surgery using light and electron microscopy and the functional recovery using the sciatic functional index and target muscle weight. HE staining revealed better ordered structured in the CDNF-treated group at 8 weeks post-surgery. Quantitative analysis of immunohistochemistry of NF200 and S-100 in the CDNF group revealed significant improvement of axonal and Schwann cell regeneration compared with the control groups at 4 weeks and 8 weeks after injury. The thickness of the myelination around the axons in the CDNF group was significantly higher than in the control groups at 8 weeks post-surgery. The CDNF group displayed higher muscle weights and significantly increased sciatic nerve index values. Our findings suggest that CDNF gene therapy could provide durable and stable CDNF protein concentration and has the potential to enhance peripheral nerve regeneration, morphological and functional recovery following nerve injury, which suggests a

Comparison of human sodium iodide symporter (hNIS) gene expression between lentiviral and adenoviral vectors in rat mesenchymal stem cell

International Nuclear Information System (INIS)

Park, So Yeon; Lee, Won Woo; Kim, Sung Jin; Lee, Heui Ran; Kim, Hyun Joo; Chung, June Key; Kim, Sang Eun

2007-01-01

Quantitative comparison of transgene expression within stem cells between lentivirus and adenovirus-mediated delivery systems has not been done. Here, we evaluated the human sodium iodide symporter (hNIS) gene expression in rat mesenchymal stem cell (rMSC) transduced by lentivirus or adenovirus, and compared the hNIS expression quantitatively between the two delivery systems. Lentiviral-mediated stably hNIS expressing rMSC (lenti-hNIS-rMSC) was constructed by cloning the hNIS gene into pLenti6/UbC/V5-DEST (Invitrogen) to obtain pLenti-hNIS, transducing rMSC with the pLenti-hNIS, and selecting with blasticidin for 3 weeks. Recombinant adenovirus expressing hNIS gene (Rad-hNIS) was produced by homologous recombination and Rad-hNIS transduced rMSC (adeno-hNIS-rMSC) was evaluated for the hNIS expression 48 hours post infection at MOI 1, 5, 20, 50, and 100. The hNIS expression in lenti-hNIS-rMSC or adeno-hNIS-rMSC was assessed by immunocytochemistry, western blot, and I-125 uptake. Immunocytochemistry using mono-clonal anti-hNIS antibody revealed that intensity of hNIS immunoreactivity in lenti-hNIS-rMSC was greater than that in adeno-hNIS-rMSC at MOl 20 but lower than that at MOl 50. Western blot analysis also showed that lenti-hNIS-rMSC was intermediate between adeno-hNIS-rMSCs at MOl 20 and 50 in hNIS expression. However in vitro I-125 uptake test demonstrated that iodide uptake in lenti-hNIS-rMSC (297046659 picomole/106 cells) was greater than that in adeno-hNIS-rMSC at MOI 100 (61682134 picomole/106 cells). These results suggest that lentivirus mediated hNIS expression is greater in terms of hNIS function but lower in terms of hNIS protein amount than adenovirus mediated hNIS expression 48 hours post infection. Stem cell tracking using hNIS as a reporter gene should be conducted in consideration of relative viral efficiency of transgene expression

[Construction of lentiviral mediated CyPA siRNA and its functions in non-small cell lung cancer].

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FENG, Yan-ming; WU, Yi-ming; TU, Xin-ming; XU, Zheng-shun; WU, Wei-dong

2010-02-01

To construct a lentiviral-vector-mediated CyPA small interference RNA (siRNA) and study its function in non-small cell lung cancer. First, four target sequences were selected according to CyPA mRNA sequence, the complementary DNA contained both sense and antisense oligonucleotides were designed, synthesized and cloned into the pGCL-GFP vector, which contained U6 promoter and green fluorescent protein (GFP). The resulting lentiviral vector containing CyPA shRNA was named Lv-shCyPA, and it was confirmed by PCR and sequencing. Next, it was cotransfected by Lipofectamine 2000 along with pHelper1.0 and pHelper 2.0 into 293T cells to package lentivirus particles. At the same time, the packed virus infected non-small cell lung cancer cell (A549), the level of CyPA protein at 5 d after infection was detected by Western Blot to screen the target of CyPA. A549 were infected with Lv-shCyPA and grown as xenografts in severe combined immunodeficient mice. Cell cycle and apoptosis were measured by FCM. It was confirmed by PCR and DNA sequencing that lentiviral-vector-mediated CyPA siRNA (Lv-shCyPA) producing CyPA shRNA was constructed successfully. The titer of concentrated virus were 1 x 10(7) TU/ml. Flow cytometric analysis demonstrated G2-M phase (11.40% +/- 0.68%) was decreased relatively in A549/LvshCyPA compared with control groups (14.52% +/- 1.19%) (Ppathways may lead to new targeted therapies for non-small cell lung cancer.

A quasi-lentiviral green fluorescent protein reporter exhibits nuclear export features of late human immunodeficiency virus type 1 transcripts

International Nuclear Information System (INIS)

Graf, Marcus; Ludwig, Christine; Kehlenbeck, Sylvia; Jungert, Kerstin; Wagner, Ralf

2006-01-01

We have previously shown that Rev-dependent expression of HIV-1 Gag from CMV immediate early promoter critically depends on the AU-rich codon bias of the gag gene. Here, we demonstrate that adaptation of the green fluorescent protein (GFP) reporter gene to HIV codon bias is sufficient to turn this hivGFP RNA into a quasi-lentiviral message following the rules of late lentiviral gene expression. Accordingly, GFP expression was significantly decreased in transfected cells strictly correlating with reduced RNA levels. In the presence of the HIV 5' major splice donor, the hivGFP RNAs were stabilized in the nucleus and efficiently exported to the cytoplasm following fusion of the 3' Rev-responsive element (RRE) and coexpression of HIV-1 Rev. This Rev-dependent translocation was specifically inhibited by leptomycin B suggesting export via the CRM1-dependent pathway used by late lentiviral transcripts. In conclusion, this quasi-lentiviral reporter system may provide a new platform for developing sensitive Rev screening assays

CD133-targeted Gene Transfer Into Long-term Repopulating Hematopoietic Stem Cells

NARCIS (Netherlands)

Brendel, Christian; Goebel, Benjamin; Daniela, Abriss; Brugman, Martijn; Kneissl, Sabrina; Schwaeble, Joachim; Kaufmann, Kerstin B.; Mueller-Kuller, Uta; Kunkel, Hana; Chen-Wichmann, Linping; Abel, Tobias; Serve, Hubert; Bystrykh, Leonid; Buchholz, Christian J.; Grez, Manuel

Gene therapy for hematological disorders relies on the genetic modification of CD34(+) cells, a heterogeneous cell population containing about 0.01% long-term repopulating cells. Here, we show that the lentiviral vector CD133-LV, which uses a surface marker on human primitive hematopoietic stem

Progresses towards safe and efficient gene therapy vectors.

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Chira, Sergiu; Jackson, Carlo S; Oprea, Iulian; Ozturk, Ferhat; Pepper, Michael S; Diaconu, Iulia; Braicu, Cornelia; Raduly, Lajos-Zsolt; Calin, George A; Berindan-Neagoe, Ioana

2015-10-13

The emergence of genetic engineering at the beginning of the 1970's opened the era of biomedical technologies, which aims to improve human health using genetic manipulation techniques in a clinical context. Gene therapy represents an innovating and appealing strategy for treatment of human diseases, which utilizes vehicles or vectors for delivering therapeutic genes into the patients' body. However, a few past unsuccessful events that negatively marked the beginning of gene therapy resulted in the need for further studies regarding the design and biology of gene therapy vectors, so that this innovating treatment approach can successfully move from bench to bedside. In this paper, we review 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. At the end of the manuscript, we summarized the main advantages and disadvantages of common gene therapy vectors and we discuss possible future directions for potential therapeutic vectors.

The evolution of heart gene delivery vectors

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Wasala, Nalinda B.; Shin, Jin-Hong; Duan, Dongsheng

2012-01-01

Gene therapy holds promise for treating numerous heart diseases. A key premise for the success of cardiac gene therapy is the development of powerful gene transfer vehicles that can achieve highly efficient and persistent gene transfer specifically in the heart. Other features of an ideal vector include negligible toxicity, minimal immunogenicity and easy manufacturing. Rapid progress in the fields of molecular biology and virology has offered great opportunities to engineer various genetic materials for heart gene delivery. Several nonviral vectors (e.g. naked plasmids, plasmid lipid/polymer complexes and oligonucleotides) have been tested. Commonly used viral vectors include lentivirus, adenovirus and adeno-associated virus. Among these, adeno-associated virus has shown many attractive features for pre-clinical experimentation in animal models of heart diseases. We review the history and evolution of these vectors for heart gene transfer. PMID:21837689

AAV Vectorization of DSB-mediated Gene Editing Technologies.

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Moser, Rachel J; Hirsch, Matthew L

2016-01-01

Recent work both at the bench and the bedside demonstrate zinc-finger nucleases (ZFNs), CRISPR/Cas9, and other programmable site-specific endonuclease technologies are being successfully utilized within and alongside AAV vectors to induce therapeutically relevant levels of directed gene editing within the human chromosome. Studies from past decades acknowledge that AAV vector genomes are enhanced substrates for homology-directed repair in the presence or absence of targeted DNA damage within the host genome. Additionally, AAV vectors are currently the most efficient format for in vivo gene delivery with no vector related complications in >100 clinical trials for diverse diseases. At the same time, advancements in the design of custom-engineered site-specific endonucleases and the utilization of elucidated endonuclease formats have resulted in efficient and facile genetic engineering for basic science and for clinical therapies. AAV vectors and gene editing technologies are an obvious marriage, using AAV for the delivery of repair substrate and/or a gene encoding a designer endonuclease; however, while efficient delivery and enhanced gene targeting by vector genomes are advantageous, other attributes of AAV vectors are less desirable for gene editing technologies. This review summarizes the various roles that AAV vectors play in gene editing technologies and provides insight into its trending applications for the treatment of genetic diseases.

Downregulation of mouse CCR3 by lentiviral shRNA inhibits proliferation and induces apoptosis of mouse eosinophils.

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Zhu, Xin-Hua; Liao, Bing; Xu, Yi; Liu, Ke; Huang, Yun; Huang, Quan-Long; Liu, Yue-Hui

2017-02-01

RNA interference has been considered as an effective gene silencing method in basic and preclinical investigations. The aims of the present study were to construct a lentiviral vector expressing a short hairpin RNA (shRNA) targeting the murine CC chemokine receptor 3 (mCCR3), and to investigate its effects on the proliferation and apoptosis of mouse eosinophils. A recombinant lentiviral vector expressing four fragments of mouse CCR3 shRNA (pLVX‑mCCR3‑1+2+3+4‑shRNA) was constructed using subcloning techniques. This novel lentivirus was then packaged into 293T cells by co‑transduction with plasmids, including Baculo p35, pCMV R8.2 and VSV. The interference effects of the vector were verified using polymerase chain reaction (PCR) and western blot analyses. The effects of the interference on the proliferation and apoptosis of mouse eosinophils were investigated using 3‑(4,5‑dimethylthiazol‑2‑yl)‑5‑(3‑carboxymethoxyphenyl)‑2‑(4‑sulfophenyl)‑2H‑tetrazolium and terminal deoxynucleotidyl transferase dUTP nick end labeling methods, respectively. The results of the PCR and western blot analyses confirmed that the novel recombinant vector, pLVX‑mCCR3‑1+2+3+4‑shRNA, had high efficiency in inhibiting the mRNA and protein expression levels of mCCR3 in mouse eosinophils. The downregulation of mCCR3 significantly inhibited proliferation of the eosinophils. Furthermore, the present study found that the downregulation of mCCR3 significantly promoted apoptosis of the eosinophils. Therefore, the downregulation of mCCR3 led to the inhibition of proliferation and induction of apoptosis in mouse eosinophils. The predominant characteristics of allergic rhinitis are eosinophil infiltration and release of inflammatory mediators, which appear in a variety of clinical manifestations. The results of the present study indicate that mCCR3 silencing may serve as a putative approach for the treatment of allergic rhinitis.

CLEC4M慢病毒载体的构建及其在K562细胞中的表达

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WANG Yuanyuan

2014-06-01

Full Text Available ObjectiveTo construct the lentiviral vector encoding CLEC4M and prepare K-562 cells with stable overexpression of CLEC4M. MethodsThe gene sequence of normal CLEC4M was cloned by RT-PCR and then inserted into GV166 vector to construct GV166-CLEC4M lentiviral expression vector, and then lentiviral packaging was performed by transfection of 293T cells. The obtained lentiviral liquid was used to infect human leukemia cell line K-562. Real-time PCR and Western blot were used to detect the overexpression of CLEC4M in K-562 cells. ResultsSequencing showed that the recombinant lentiviral expression plasmid GV166-CLEC4M was successfully constructed. Lentiviruses could efficiently infect K-562 cells, according to real-time PCR. CLEC4M was successfully over-expressed in K-562 cells at mRNA and protein levels. ConclusionThe construction of lentiviral vector encoding CLEC4M lays a foundation for further study of CLEC4M gene involved in HCV entry into host cells.

[Experimental study on human periodontal ligament cells transfected with human amelogenin gene].

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Yu, Guang; Shu, Rong; Sun, Ying; Cheng, Lan; Song, Zhong-Chen; Zhang, Xiu-Li

2008-02-01

To construct the recombinant lentiviral vector of human amelogenin gene, infect human periodontal ligament cells with the recombinant lentivirus, and evaluate the feasibility of applying modified PDLCs as seeds for a further periodontal reconstruction. The mature peptide of hAm cDNA was cloned and linked into the vector plasmid, the recombinant plasmid FUAmW was confirmed by double enzyme digestion and sequence analysis. Recombinant lentivirus was prepared from 293T cells by polytheylenimine (PEI)-mediated transient cotransfection. The hPDLCs and 293T cells were infected with the generated lentivirus. The infection efficiency was analysed by detection of green fluorescence protein (GFP) with fluorescent microscope and flow cytometer 72 hours later. The expression of hAm gene was detected by reverse transcription polymerase chain reaction (RT-PCR). The sequence of inserted fragment in recombinant plasmid was identical to the hAm sequence reported in Genebank. Green fluorescence was visible under fluorescent microscope, FCM assay showed that positive percentage was 69.46% and 33.99% in 293T and hPDLCs, respectively. The targeted gene was obtained in the experimental groups by RT-PCR. The recombinan lentiviral vector of hAm gene is constructed successfully and it could be transfected into cultured hPDLCs. hAm gene and seed cells may be used for further study in the fields periodontal tissue engineering. Supported by National Natural Science Foundation of China (Grant No. 30672315).

Modified montmorillonite as vector for gene delivery.

Science.gov (United States)

Lin, Feng-Huei; Chen, Chia-Hao; Cheng, Winston T K; Kuo, Tzang-Fu

2006-06-01

Currently, gene delivery systems can be divided into two parts: viral or non-viral vectors. In general, viral vectors have a higher efficiency on gene delivery. However, they may sometimes provoke mutagenesis and carcinogenesis once re-activating in human body. Lots of non-viral vectors have been developed that tried to solve the problems happened on viral vectors. Unfortunately, most of non-viral vectors showed relatively lower transfection rate. The aim of this study is to develop a non-viral vector for gene delivery system. Montmorillonite (MMT) is one of clay minerals that consist of hydrated aluminum with Si-O tetrahedrons on the bottom of the layer and Al-O(OH)2 octahedrons on the top. The inter-layer space is about 12 A. The room is not enough to accommodate DNA for gene delivery. In the study, the cationic hexadecyltrimethylammonium (HDTMA) will be intercalated into the interlayer of MMT as a layer expander to expand the layer space for DNA accommodation. The optimal condition for the preparation of DNA-HDTMA-MMT is as follows: 1 mg of 1.5CEC HDTMA-MMT was prepared under pH value of 10.7 and with soaking time for 2 h. The DNA molecules can be protected from nuclease degradation, which can be proven by the electrophoresis analysis. DNA was successfully transfected into the nucleus of human dermal fibroblast and expressed enhanced green fluorescent protein (EGFP) gene with green fluorescence emission. The HDTMA-MMT has a great potential as a vector for gene delivery in the future.

Assessment of Integration-defective HIV-1 and EIAV Vectors In Vitro and In Vivo

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Scott Ellis

2012-01-01

Full Text Available The interest in integrase-defective lentiviral vectors (IDLVs stems from their potential advantage of large cloning capacity and broad cell tropism while avoiding the possibility of insertional mutagenesis. Here, we directly compared the transducing potential of IDLVs based on the equine infectious anemia virus (EIAV to the more commonly described HIV-1 IDLVs. IDLVs were constructed by introducing equivalent single/triple mutations into the integrase catalytic triad. We show that both the single and the triple mutant HIV-1 IDLVs transduce the PC12 cells, but not the C2C12 cells, with similar efficiency to their parental HIV-1 vector. In contrast, the single and triple EIAV IDLVs did not efficiently transduce either differentiated cell line. Moreover, this HIV-1 IDLV-mediated expression was independent of any residual integration activity because reporter expression was lost when cell cycling was restored. Four weeks following stereotactic administration into adult rat brains, only the single HIV-1 IDLV mutant displayed a comparable transduction profile to the parental HIV-1 vector. In contrast, neither EIAV IDLV mutants showed significant reporter gene expression. This work indicates that the transducing potential of IDLVs appears to depend not only on the choice of integrase mutation and type of target cell, but also on the nature of the lentiviral vector.

Targeted cancer gene therapy : the flexibility of adenoviral gene therapy vectors

NARCIS (Netherlands)

Rots, MG; Curiel, DT; Gerritsen, WR; Haisma, HJ

2003-01-01

Recombinant adenoviral vectors are promising reagents for therapeutic interventions in humans, including gene therapy for biologically complex diseases like cancer and cardiovascular diseases. In this regard, the major advantage of adenoviral vectors is their superior in vivo gene transfer

Identifying Cancer Driver Genes Using Replication-Incompetent Retroviral Vectors

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Victor M. Bii

2016-10-01

Full Text Available Identifying novel genes that drive tumor metastasis and drug resistance has significant potential to improve patient outcomes. High-throughput sequencing approaches have identified cancer genes, but distinguishing driver genes from passengers remains challenging. Insertional mutagenesis screens using replication-incompetent retroviral vectors have emerged as a powerful tool to identify cancer genes. Unlike replicating retroviruses and transposons, replication-incompetent retroviral vectors lack additional mutagenesis events that can complicate the identification of driver mutations from passenger mutations. They can also be used for almost any human cancer due to the broad tropism of the vectors. Replication-incompetent retroviral vectors have the ability to dysregulate nearby cancer genes via several mechanisms including enhancer-mediated activation of gene promoters. The integrated provirus acts as a unique molecular tag for nearby candidate driver genes which can be rapidly identified using well established methods that utilize next generation sequencing and bioinformatics programs. Recently, retroviral vector screens have been used to efficiently identify candidate driver genes in prostate, breast, liver and pancreatic cancers. Validated driver genes can be potential therapeutic targets and biomarkers. In this review, we describe the emergence of retroviral insertional mutagenesis screens using replication-incompetent retroviral vectors as a novel tool to identify cancer driver genes in different cancer types.

Gene Therapy Approaches to Hemoglobinopathies.

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Ferrari, Giuliana; Cavazzana, Marina; Mavilio, Fulvio

2017-10-01

Gene therapy for hemoglobinopathies is currently based on transplantation of autologous hematopoietic stem cells genetically modified with a lentiviral vector expressing a globin gene under the control of globin transcriptional regulatory elements. Preclinical and early clinical studies showed the safety and potential efficacy of this therapeutic approach as well as the hurdles still limiting its general application. In addition, for both beta-thalassemia and sickle cell disease, an altered bone marrow microenvironment reduces the efficiency of stem cell harvesting as well as engraftment. These hurdles need be addressed for gene therapy for hemoglobinopathies to become a clinical reality. Copyright © 2017 Elsevier Inc. All rights reserved.

A designated centre for people with disabilities operated by COPE Foundation, Cork

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McGinley, Lisa

2011-03-07

Abstract Introduction A combination of gene and cell therapies has the potential to significantly enhance the therapeutic value of mesenchymal stem cells (MSCs). The development of efficient gene delivery methods is essential if MSCs are to be of benefit using such an approach. Achieving high levels of transgene expression for the required period of time, without adversely affecting cell viability and differentiation capacity, is crucial. In the present study, we investigate lentiviral vector-mediated genetic modification of rat bone-marrow derived MSCs and examine any functional effect of such genetic modification in an in vitro model of ischaemia. Methods Transduction efficiency and transgene persistence of second and third generation rHIV-1 based lentiviral vectors were tested using reporter gene constructs. Use of the rHIV-pWPT-EF1-α-GFP-W vector was optimised in terms of dose, toxicity, cell species, and storage. The in vivo condition of ischaemia was modelled in vitro by separation into its associated constituent parts i.e. hypoxia, serum and glucose deprivation, in which the effect of therapeutic gene over-expression on MSC survival was investigated. Results The second generation lentiviral vector rHIV-pWPT-EF1-α-GFP-W, was the most efficient and provided the most durable transgene expression of the vectors tested. Transduction with this vector did not adversely affect MSC morphology, viability or differentiation potential, and transgene expression levels were unaffected by cryopreservation of transduced cells. Over-expression of HSP70 resulted in enhanced MSC survival and increased resistance to apoptosis in conditions of hypoxia and ischaemia. MSC differentiation capacity was significantly reduced after oxygen deprivation, but was preserved with HSP70 over-expression. Conclusions Collectively, these data validate the use of lentiviral vectors for efficient in vitro gene delivery to MSCs and suggest that lentiviral vector transduction can facilitate

Towards a clinically relevant lentiviral transduction protocol for primary human CD34 hematopoietic stem/progenitor cells.

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Michelle Millington

2009-07-01

Full Text Available Hematopoietic stem cells (HSC, in particular mobilized peripheral blood stem cells, represent an attractive target for cell and gene therapy. Efficient gene delivery into these target cells without compromising self-renewal and multi-potency is crucial for the success of gene therapy. We investigated factors involved in the ex vivo transduction of CD34(+ HSCs in order to develop a clinically relevant transduction protocol for gene delivery. Specifically sought was a protocol that allows for efficient transduction with minimal ex vivo manipulation without serum or other reagents of animal origin.Using commercially available G-CSF mobilized peripheral blood (PB CD34(+ cells as the most clinically relevant target, we systematically examined factors including the use of serum, cytokine combinations, pre-stimulation time, multiplicity of infection (MOI, transduction duration and the use of spinoculation and/or retronectin. A self-inactivating lentiviral vector (SIN-LV carrying enhanced green fluorescent protein (GFP was used as the gene delivery vehicle. HSCs were monitored for transduction efficiency, surface marker expression and cellular function. We were able to demonstrate that efficient gene transduction can be achieved with minimal ex vivo manipulation while maintaining the cellular function of transduced HSCs without serum or other reagents of animal origin.This study helps to better define factors relevant towards developing a standard clinical protocol for the delivery of SIN-LV into CD34(+ cells.

Hybrid lentivirus-phiC31-int-NLS vector allows site-specific recombination in murine and human cells but induces DNA damage.

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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.

[Construction of BAD Lentivirus Vector and Its Effect on Proliferation in A549 Cell Lines].

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Huang, Na; He, Yan-qi; Zhu, Jing; Li, Wei-min

2015-05-01

To construct the recombinant lentivirus expressing vector BAD (Bcl-2-associated death protein) gene and to study its effect on A549 cell proliferation. The BAD gene was amplified from plasmid pAV-MCMV-BAD-GFP by PCR. The purified BAD gene fragment was inserted into a lentivirus vector (pLVX-IRES-ZsGreen 1), and the insertion was identified by PCR, restriction endonuclease analysis and DNA sequencing. A549 cells were then transfected with the packaged recombinant lentivirus, and resistant cell clones were selected with flow cytometry. The expression of BAD in A549 cell lines stably transduction with a lentivirus was examined using Western blot. The effect of BAD overexpression on proliferation of A549 cells was evaluated by using CCK-8 kit. Restriction enzyme digestion and DNA sequencing showed that the full-length BAD gene (507 bp) had been successfully subcloned into the lentiviral vector to result in the recombinant vector pLVX-IRES-ZsGreen 1. Monoclonal cell lines BAD-A549 was produced after transfection with the recombinant lentivirus and selected with flow cytometry. Stable expression of BAD protein was verified by Western blot. In vitro, the OD value in BAD group was significantly lower than that of control groups from 120-144 h (PBAD gene had been successfully generated. In vitro, BAD overexpression significantly inhibited A549 cells proliferation.

Chromosome preference of disease genes and vectorization for the prediction of non-coding disease genes.

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Peng, Hui; Lan, Chaowang; Liu, Yuansheng; Liu, Tao; Blumenstein, Michael; Li, Jinyan

2017-10-03

Disease-related protein-coding genes have been widely studied, but disease-related non-coding genes remain largely unknown. This work introduces a new vector to represent diseases, and applies the newly vectorized data for a positive-unlabeled learning algorithm to predict and rank disease-related long non-coding RNA (lncRNA) genes. This novel vector representation for diseases consists of two sub-vectors, one is composed of 45 elements, characterizing the information entropies of the disease genes distribution over 45 chromosome substructures. This idea is supported by our observation that some substructures (e.g., the chromosome 6 p-arm) are highly preferred by disease-related protein coding genes, while some (e.g., the 21 p-arm) are not favored at all. The second sub-vector is 30-dimensional, characterizing the distribution of disease gene enriched KEGG pathways in comparison with our manually created pathway groups. The second sub-vector complements with the first one to differentiate between various diseases. Our prediction method outperforms the state-of-the-art methods on benchmark datasets for prioritizing disease related lncRNA genes. The method also works well when only the sequence information of an lncRNA gene is known, or even when a given disease has no currently recognized long non-coding genes.

Therapeutic hemoglobin levels after gene transfer in β-thalassemia mice and in hematopoietic cells of β-thalassemia and sickle cells disease patients.

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Laura Breda

Full Text Available Preclinical and clinical studies demonstrate the feasibility of treating β-thalassemia and Sickle Cell Disease (SCD by lentiviral-mediated transfer of the human β-globin gene. However, previous studies have not addressed whether the ability of lentiviral vectors to increase hemoglobin synthesis might vary in different patients.We generated lentiviral vectors carrying the human β-globin gene with and without an ankyrin insulator and compared their ability to induce hemoglobin synthesis in vitro and in thalassemic mice. We found that insertion of an ankyrin insulator leads to higher, potentially therapeutic levels of human β-globin through a novel mechanism that links the rate of transcription of the transgenic β-globin mRNA during erythroid differentiation with polysomal binding and efficient translation, as reported here for the first time. We also established a preclinical assay to test the ability of this novel vector to synthesize adult hemoglobin in erythroid precursors and in CD34(+ cells isolated from patients affected by β-thalassemia and SCD. Among the thalassemic patients, we identified a subset of specimens in which hemoglobin production can be achieved using fewer copies of the vector integrated than in others. In SCD specimens the treatment with AnkT9W ameliorates erythropoiesis by increasing adult hemoglobin (Hb A and concurrently reducing the sickling tetramer (Hb S.Our results suggest two major findings. First, we discovered that for the purpose of expressing the β-globin gene the ankyrin element is particularly suitable. Second, our analysis of a large group of specimens from β-thalassemic and SCD patients indicates that clinical trials could benefit from a simple test to predict the relationship between the number of vector copies integrated and the total amount of hemoglobin produced in the erythroid cells of prospective patients. This approach would provide vital information to select the best candidates for these

Efficient Transduction of Feline Neural Progenitor Cells for Delivery of Glial Cell Line-Derived Neurotrophic Factor Using a Feline Immunodeficiency Virus-Based Lentiviral Construct

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X. Joann You

2011-01-01

Full Text Available Work has shown that stem cell transplantation can rescue or replace neurons in models of retinal degenerative disease. Neural progenitor cells (NPCs modified to overexpress neurotrophic factors are one means of providing sustained delivery of therapeutic gene products in vivo. To develop a nonrodent animal model of this therapeutic strategy, we previously derived NPCs from the fetal cat brain (cNPCs. Here we use bicistronic feline lentiviral vectors to transduce cNPCs with glial cell-derived neurotrophic factor (GDNF together with a GFP reporter gene. Transduction efficacy is assessed, together with transgene expression level and stability during induction of cellular differentiation, together with the influence of GDNF transduction on growth and gene expression profile. We show that GDNF overexpressing cNPCs expand in vitro, coexpress GFP, and secrete high levels of GDNF protein—before and after differentiation—all qualities advantageous for use as a cell-based approach in feline models of neural degenerative disease.

Enrichment of human hematopoietic stem/progenitor cells facilitates transduction for stem cell gene therapy.

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Baldwin, Kismet; Urbinati, Fabrizia; Romero, Zulema; Campo-Fernandez, Beatriz; Kaufman, Michael L; Cooper, Aaron R; Masiuk, Katelyn; Hollis, Roger P; Kohn, Donald B

2015-05-01

Autologous hematopoietic stem cell (HSC) gene therapy for sickle cell disease has the potential to treat this illness without the major immunological complications associated with allogeneic transplantation. However, transduction efficiency by β-globin lentiviral vectors using CD34-enriched cell populations is suboptimal and large vector production batches may be needed for clinical trials. Transducing a cell population more enriched for HSC could greatly reduce vector needs and, potentially, increase transduction efficiency. CD34(+) /CD38(-) cells, comprising ∼1%-3% of all CD34(+) cells, were isolated from healthy cord blood CD34(+) cells by fluorescence-activated cell sorting and transduced with a lentiviral vector expressing an antisickling form of beta-globin (CCL-β(AS3) -FB). Isolated CD34(+) /CD38(-) cells were able to generate progeny over an extended period of long-term culture (LTC) compared to the CD34(+) cells and required up to 40-fold less vector for transduction compared to bulk CD34(+) preparations containing an equivalent number of CD34(+) /CD38(-) cells. Transduction of isolated CD34(+) /CD38(-) cells was comparable to CD34(+) cells measured by quantitative PCR at day 14 with reduced vector needs, and average vector copy/cell remained higher over time for LTC initiated from CD34(+) /38(-) cells. Following in vitro erythroid differentiation, HBBAS3 mRNA expression was similar in cultures derived from CD34(+) /CD38(-) cells or unfractionated CD34(+) cells. In vivo studies showed equivalent engraftment of transduced CD34(+) /CD38(-) cells when transplanted in competition with 100-fold more CD34(+) /CD38(+) cells. This work provides initial evidence for the beneficial effects from isolating human CD34(+) /CD38(-) cells to use significantly less vector and potentially improve transduction for HSC gene therapy. © 2015 AlphaMed Press.

Simian virus 40 vectors for pulmonary gene therapy

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Oppenheim Ariella

2007-10-01

Full Text Available Abstract Background Sepsis remains the leading cause of death in critically ill patients. One of the primary organs affected by sepsis is the lung, presenting as the Acute Respiratory Distress Syndrome (ARDS. Organ damage in sepsis involves an alteration in gene expression, making gene transfer a potential therapeutic modality. This work examines the feasibility of applying simian virus 40 (SV40 vectors for pulmonary gene therapy. Methods Sepsis-induced ARDS was established by cecal ligation double puncture (2CLP. SV40 vectors carrying the luciferase reporter gene (SV/luc were administered intratracheally immediately after sepsis induction. Sham operated (SO as well as 2CLP rats given intratracheal PBS or adenovirus expressing luciferase served as controls. Luc transduction was evaluated by in vivo light detection, immunoassay and luciferase mRNA detection by RT-PCR in tissue harvested from septic rats. Vector abundance and distribution into alveolar cells was evaluated using immunostaining for the SV40 VP1 capsid protein as well as by double staining for VP1 and for the surfactant protein C (proSP-C. Immunostaining for T-lymphocytes was used to evaluate the cellular immune response induced by the vector. Results Luc expression measured by in vivo light detection correlated with immunoassay from lung tissue harvested from the same rats. Moreover, our results showed vector presence in type II alveolar cells. The vector did not induce significant cellular immune response. Conclusion In the present study we have demonstrated efficient uptake and expression of an SV40 vector in the lungs of animals with sepsis-induced ARDS. These vectors appear to be capable of in vivo transduction of alveolar type II cells and may thus become a future therapeutic tool.

Intrapulmonary Versus Nasal Transduction of Murine Airways With GP64-pseudotyped Viral Vectors

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Mayumi Oakland

2013-01-01

Full Text Available Persistent viral vector-mediated transgene expression in the airways requires delivery to cells with progenitor capacity and avoidance of immune responses. Previously, we observed that GP64-pseudotyped feline immunodeficiency virus (FIV-mediated gene transfer was more efficient in the nasal airways than the large airways of the murine lung. We hypothesized that in vivo gene transfer was limited by immunological and physiological barriers in the murine intrapulmonary airways. Here, we systematically investigate multiple potential barriers to lentiviral gene transfer in the airways of mice. We show that GP64-FIV vector transduced primary cultures of well-differentiated murine nasal epithelia with greater efficiency than primary cultures of murine tracheal epithelia. We further demonstrate that neutrophils, type I interferon (IFN responses, as well as T and B lymphocytes are not the major factors limiting the transduction of murine conducting airways. In addition, we observed better transduction of GP64-pseudotyped vesicular stomatitis virus (VSV in the nasal epithelia compared with the intrapulmonary airways in mice. VSVG glycoprotein pseudotyped VSV transduced intrapulmonary epithelia with similar efficiency as nasal epithelia. Our results suggest that the differential transduction efficiency of nasal versus intrapulmonary airways by FIV vector is not a result of immunological barriers or surface area, but rather differential expression of cellular factors specific for FIV vector transduction.

A sight on the current nanoparticle-based gene delivery vectors

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Dizaj, Solmaz Maleki; Jafari, Samira; Khosroushahi, Ahmad Yari

2014-05-01

Nowadays, gene delivery for therapeutic objects is considered one of the most promising strategies to cure both the genetic and acquired diseases of human. The design of efficient gene delivery vectors possessing the high transfection efficiencies and low cytotoxicity is considered the major challenge for delivering a target gene to specific tissues or cells. On this base, the investigations on non-viral gene vectors with the ability to overcome physiological barriers are increasing. Among the non-viral vectors, nanoparticles showed remarkable properties regarding gene delivery such as the ability to target the specific tissue or cells, protect target gene against nuclease degradation, improve DNA stability, and increase the transformation efficiency or safety. This review attempts to represent a current nanoparticle based on its lipid, polymer, hybrid, and inorganic properties. Among them, hybrids, as efficient vectors, are utilized in gene delivery in terms of materials (synthetic or natural), design, and in vitro/ in vivo transformation efficiency.

Striatal modulation of BDNF expression using microRNA124a-expressing lentiviral vectors impairs ethanol-induced conditioned-place preference and voluntary alcohol consumption.

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Bahi, Amine; Dreyer, Jean-Luc

2013-07-01

Alcohol abuse is a major health, economic and social concern in modern societies, but the exact molecular mechanisms underlying ethanol addiction remain elusive. Recent findings show that small non-coding microRNA (miRNA) signaling contributes to complex behavioral disorders including drug addiction. However, the role of miRNAs in ethanol-induced conditioned-place preference (CPP) and voluntary alcohol consumption has not yet been directly addressed. Here, we assessed the expression profile of miR124a in the dorsal striatum of rats upon ethanol intake. The results show that miR124a was downregulated in the dorso-lateral striatum (DLS) following alcohol drinking. Then, we identified brain-derived neurotrophic factor (BDNF) as a direct target of miR124a. In fact, BDNF mRNA was upregulated following ethanol drinking. We used lentiviral vector (LV) gene transfer technology to further address the role of miR124a and its direct target BDNF in ethanol-induced CPP and alcohol consumption. Results reveal that stereotaxic injection of LV-miR124a in the DLS enhances ethanol-induced CPP as well as voluntary alcohol consumption in a two-bottle choice drinking paradigm. Moreover, miR124a-silencer (LV-siR124a) as well as LV-BDNF infusion in the DLS attenuates ethanol-induced CPP as well as voluntary alcohol consumption. Importantly, LV-miR124a, LV-siR124a and LV-BDNF have no effect on saccharin and quinine intake. Our findings indicate that striatal miR124a and BDNF signaling have crucial roles in alcohol consumption and ethanol conditioned reward. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Current status of gene therapy for motor neuron disease

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Xingkai An; Rong Peng; Shanshan Zhao

2006-01-01

OBJECTIVE: Although the etiology and pathogenesis of motor neuron disease is still unknown, there are many hypotheses on motor neuron mitochondrion, cytoskeleton structure and functional injuries. Thus, gene therapy of motor neuron disease has become a hot topic to apply in viral vector, gene delivery and basic gene techniques.DATA SOURCES: The related articles published between January 2000 and October 2006 were searched in Medline database and ISl database by computer using the keywords "motor neuron disease, gene therapy", and the language is limited to English. Meanwhile, the related references of review were also searched by handiwork. STUDY SELECTION: Original articles and referred articles in review were chosen after first hearing, then the full text which had new ideas were found, and when refer to the similar study in the recent years were considered first.DATA EXTRACTION: Among the 92 related articles, 40 ones were accepted, and 52 were excluded because of repetitive study or reviews.DATA SYNTHESIS: The viral vectors of gene therapy for motor neuron disease include adenoviral, adeno-associated viral vectors, herpes simplex virus type 1 vectors and lentiviral vectors. The delivery of them can be achieved by direct injection into the brain, or by remote delivery after injection vectors into muscle or peripheral nerves, or by ex vivo gene transfer. The viral vectors of gene therapy for motor neuron disease have been successfully developed, but the gene delivery of them is hampered by some difficulties. The RNA interference and neuroprotection are the main technologies for gene-based therapy in motor neuron disease. CONCLUSION : The RNA interference for motor neuron disease has succeeded in animal models, and the neuroprotection also does. But, there are still a lot of questions for gene therapy in the clinical treatment of motor neuron disease.

PCR-based detection of gene transfer vectors: application to gene doping surveillance.

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Perez, Irene C; Le Guiner, Caroline; Ni, Weiyi; Lyles, Jennifer; Moullier, Philippe; Snyder, Richard O

2013-12-01

Athletes who illicitly use drugs to enhance their athletic performance are at risk of being banned from sports competitions. Consequently, some athletes may seek new doping methods that they expect to be capable of circumventing detection. With advances in gene transfer vector design and therapeutic gene transfer, and demonstrations of safety and therapeutic benefit in humans, there is an increased probability of the pursuit of gene doping by athletes. In anticipation of the potential for gene doping, assays have been established to directly detect complementary DNA of genes that are top candidates for use in doping, as well as vector control elements. The development of molecular assays that are capable of exposing gene doping in sports can serve as a deterrent and may also identify athletes who have illicitly used gene transfer for performance enhancement. PCR-based methods to detect foreign DNA with high reliability, sensitivity, and specificity include TaqMan real-time PCR, nested PCR, and internal threshold control PCR.

Over-expression of brain-derived neurotrophic factor in mesenchymal stem cells transfected with recombinant lentivirus BDNF gene.

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Zhang, X; Zhu, J; Zhang, K; Liu, T; Zhang, Z

2016-12-30

This study was aimed at investigating the expression of brain-derived neurotrophic factor (BDNF) in mesenchymal stem cells (MSCs) modified with recombinant lentivirus bearing BDNF gene. Lentivirus vectors bearing BDNF gene were constructed. MSCs were isolated from rats and cultured. The lentiviral vectors containing BDNF gene were transfected into the MSCs, and BDNF gene and protein expressions were monitored with enhanced green fluorescent protein (EGFP). RT-PCR and Western blot were used to measure gene and protein expressions, respectibvely in MSCs, MSCs-EGFP and MSCs-EGFP-BDNF groups. Green fluorescence assay confirmed successful transfection of BDNF gene recombinant lentivirus into MSCs. RT-PCR and Western blot revealed that BDNF gene and protein expressions in the MSCs-EGFP-BDNF group were significantly higher than that in MSCs group and MSCs-EGFP group. There were no statistically significant differences in gene expression between MSCs and MSCs-EGFP groups. MSCs can over-express BDNF when transfected with recombinant lentivirus bearing BDNF gene.

VISPA2: a scalable pipeline for high-throughput identification and annotation of vector integration sites.

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Spinozzi, Giulio; Calabria, Andrea; Brasca, Stefano; Beretta, Stefano; Merelli, Ivan; Milanesi, Luciano; Montini, Eugenio

2017-11-25

Bioinformatics tools designed to identify lentiviral or retroviral vector insertion sites in the genome of host cells are used to address the safety and long-term efficacy of hematopoietic stem cell gene therapy applications and to study the clonal dynamics of hematopoietic reconstitution. The increasing number of gene therapy clinical trials combined with the increasing amount of Next Generation Sequencing data, aimed at identifying integration sites, require both highly accurate and efficient computational software able to correctly process "big data" in a reasonable computational time. Here we present VISPA2 (Vector Integration Site Parallel Analysis, version 2), the latest optimized computational pipeline for integration site identification and analysis with the following features: (1) the sequence analysis for the integration site processing is fully compliant with paired-end reads and includes a sequence quality filter before and after the alignment on the target genome; (2) an heuristic algorithm to reduce false positive integration sites at nucleotide level to reduce the impact of Polymerase Chain Reaction or trimming/alignment artifacts; (3) a classification and annotation module for integration sites; (4) a user friendly web interface as researcher front-end to perform integration site analyses without computational skills; (5) the time speedup of all steps through parallelization (Hadoop free). We tested VISPA2 performances using simulated and real datasets of lentiviral vector integration sites, previously obtained from patients enrolled in a hematopoietic stem cell gene therapy clinical trial and compared the results with other preexisting tools for integration site analysis. On the computational side, VISPA2 showed a > 6-fold speedup and improved precision and recall metrics (1 and 0.97 respectively) compared to previously developed computational pipelines. These performances indicate that VISPA2 is a fast, reliable and user-friendly tool for

Targeting of human interleukin-12B by small hairpin RNAs in xenografted psoriatic skin

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Jakobsen Maria

2011-02-01

Full Text Available Abstract Background Psoriasis is a chronic inflammatory skin disorder that shows as erythematous and scaly lesions. The pathogenesis of psoriasis is driven by a dysregulation of the immune system which leads to an altered cytokine production. Proinflammatory cytokines that are up-regulated in psoriasis include tumor necrosis factor alpha (TNFα, interleukin-12 (IL-12, and IL-23 for which monoclonal antibodies have already been approved for clinical use. We have previously documented the therapeutic applicability of targeting TNFα mRNA for RNA interference-mediated down-regulation by anti-TNFα small hairpin RNAs (shRNAs delivered by lentiviral vectors to xenografted psoriatic skin. The present report aims at targeting mRNA encoding the shared p40 subunit (IL-12B of IL-12 and IL-23 by cellular transduction with lentiviral vectors encoding anti-IL12B shRNAs. Methods Effective anti-IL12B shRNAs are identified among a panel of shRNAs by potency measurements in cultured cells. The efficiency and persistency of lentiviral gene delivery to xenografted human skin are investigated by bioluminescence analysis of skin treated with lentiviral vectors encoding the luciferase gene. shRNA-expressing lentiviral vectors are intradermally injected in xenografted psoriatic skin and the effects of the treatment evaluated by clinical psoriasis scoring, by measurements of epidermal thickness, and IL-12B mRNA levels. Results Potent and persistent transgene expression following a single intradermal injection of lentiviral vectors in xenografted human skin is reported. Stable IL-12B mRNA knockdown and reduced epidermal thickness are achieved three weeks after treatment of xenografted psoriatic skin with lentivirus-encoded anti-IL12B shRNAs. These findings mimick the results obtained with anti-TNFα shRNAs but, in contrast to anti-TNFα treatment, anti-IL12B shRNAs do not ameliorate the psoriatic phenotype as evaluated by semi-quantitative clinical scoring and by

Graphene materials as 2D non-viral gene transfer vector platforms.

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Vincent, M; de Lázaro, I; Kostarelos, K

2017-03-01

Advances in genomics and gene therapy could offer solutions to many diseases that remain incurable today, however, one of the critical reasons halting clinical progress is due to the difficulty in designing efficient and safe delivery vectors for the appropriate genetic cargo. Safety and large-scale production concerns counter-balance the high gene transfer efficiency achieved with viral vectors, while non-viral strategies have yet to become sufficiently efficient. The extraordinary physicochemical, optical and photothermal properties of graphene-based materials (GBMs) could offer two-dimensional components for the design of nucleic acid carrier systems. We discuss here such properties and their implications for the optimization of gene delivery. While the design of such vectors is still in its infancy, we provide here an exhaustive and up-to-date analysis of the studies that have explored GBMs as gene transfer vectors, focusing on the functionalization strategies followed to improve vector performance and on the biological effects attained.

Self-focusing therapeutic gene delivery with intelligent gene vector swarms: intra-swarm signalling through receptor transgene expression in targeted cells.

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Tolmachov, Oleg E

2015-01-01

Gene delivery in vivo that is tightly focused on the intended target cells is essential to maximize the benefits of gene therapy and to reduce unwanted side-effects. Cell surface markers are immediately available for probing by therapeutic gene vectors and are often used to direct gene transfer with these vectors to specific target cell populations. However, it is not unusual for the choice of available extra-cellular markers to be too scarce to provide a reliable definition of the desired therapeutically relevant set of target cells. Therefore, interrogation of intra-cellular determinants of cell-specificity, such as tissue-specific transcription factors, can be vital in order to provide detailed cell-guiding information to gene vector particles. An important improvement in cell-specific gene delivery can be achieved through auto-buildup in vector homing efficiency using intelligent 'self-focusing' of swarms of vector particles on target cells. Vector self-focusing was previously suggested to rely on the release of diffusible chemo-attractants after a successful target-specific hit by 'scout' vector particles. I hypothesize that intelligent self-focusing behaviour of swarms of cell-targeted therapeutic gene vectors can be accomplished without the employment of difficult-to-use diffusible chemo-attractants, instead relying on the intra-swarm signalling through cells expressing a non-diffusible extra-cellular receptor for the gene vectors. In the proposed model, cell-guiding information is gathered by the 'scout' gene vector particles, which: (1) attach to a variety of cells via a weakly binding (low affinity) receptor; (2) successfully facilitate gene transfer into these cells; (3) query intra-cellular determinants of cell-specificity with their transgene expression control elements and (4) direct the cell-specific biosynthesis of a vector-encoded strongly binding (high affinity) cell-surface receptor. Free members of the vector swarm loaded with therapeutic cargo

Breeding of transgenic cattle for human coagulation factor IX by a combination of lentiviral system and cloning.

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Monzani, P S; Sangalli, J R; De Bem, T H C; Bressan, F F; Fantinato-Neto, P; Pimentel, J R V; Birgel-Junior, E H; Fontes, A M; Covas, D T; Meirelles, F V

2013-02-28

Recombinant coagulation factor IX must be produced in mammalian cells because FIX synthesis involves translational modifications. Human cell culture-based expression of human coagulation factor IX (hFIX) is expensive, and large-scale production capacity is limited. Transgenic animals may greatly increase the yield of therapeutic proteins and reduce costs. In this study, we used a lentiviral system to obtain transgenic cells and somatic cell nuclear transfer (SCNT) to produce transgenic animals. Lentiviral vectors carrying hFIX driven by 3 bovine β-casein promoters were constructed. Bovine epithelial mammary cells were transduced by lentivirus, selected with blasticidin, plated on extracellular matrix, and induced by lactogenic hormones; promoter activity was evaluated by quantitative PCR. Transcriptional activity of the 5.335-kb promoter was 6-fold higher than the 3.392- and 4.279-kb promoters, which did not significantly differ. Transgenic bovine fibroblasts were transduced with lentivirus carrying the 5.335-kb promoter and used as donor cells for SCNT. Cloned transgenic embryo production yielded development rates of 28.4%, similar to previous reports on cloned non-transgenic embryos. The embryos were transferred to recipient cows (N = 21) and 2 births of cloned transgenic cattle were obtained. These results suggest combination of the lentiviral system and cloning may be a good strategy for production of transgenic cattle.

An adenovirus vector incorporating carbohydrate binding domains utilizes glycans for gene transfer.

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Julius W Kim

Full Text Available Vectors based on human adenovirus serotype 5 (HAdV-5 continue to show promise as delivery vehicles for cancer gene therapy. Nevertheless, it has become clear that therapeutic benefit is directly linked to tumor-specific vector localization, highlighting the need for tumor-targeted gene delivery. Aberrant glycosylation of cell surface glycoproteins and glycolipids is a central feature of malignant transformation, and tumor-associated glycoforms are recognized as cancer biomarkers. On this basis, we hypothesized that cancer-specific cell-surface glycans could be the basis of a novel paradigm in HAdV-5-based vector targeting.As a first step toward this goal, we constructed a novel HAdV-5 vector encoding a unique chimeric fiber protein that contains the tandem carbohydrate binding domains of the fiber protein of the NADC-1 strain of porcine adenovirus type 4 (PAdV-4. This glycan-targeted vector displays augmented CAR-independent gene transfer in cells with low CAR expression. Further, we show that gene transfer is markedly decreased in cells with genetic glycosylation defects and by inhibitors of glycosylation in normal cells.These data provide the initial proof-of-concept for HAdV-5 vector-mediated gene delivery based on the presence of cell-surface carbohydrates. Further development of this new targeting paradigm could provide targeted gene delivery based on vector recognition of disease-specific glycan biomarkers.

Manufacture of Third-Generation Lentivirus for Preclinical Use, with Process Development Considerations for Translation to Good Manufacturing Practice.

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Gándara, Carolina; Affleck, Valerie; Stoll, Elizabeth Ann

2018-02-01

Lentiviral vectors are used in laboratories around the world for in vivo and ex vivo delivery of gene therapies, and increasingly clinical investigation as well as preclinical applications. The third-generation lentiviral vector system has many advantages, including high packaging capacity, stable gene expression in both dividing and post-mitotic cells, and low immunogenicity in the recipient organism. Yet, the manufacture of these vectors is challenging, especially at high titers required for direct use in vivo, and further challenges are presented by the process of translating preclinical gene therapies toward manufacture of products for clinical investigation. The goals of this paper are to report the protocol for manufacturing high-titer third-generation lentivirus for preclinical testing and to provide detailed information on considerations for translating preclinical viral vector manufacture toward scaled-up platforms and processes in order to make gene therapies under Good Manufacturing Practice that are suitable for clinical trials.

Hobo-like transposable elements as non-drosophilid gene vectors

International Nuclear Information System (INIS)

O'Brochta, D.A.; Warren, W.D.; Saville, K.J.; Whyard, S.; Mende, H.A.; Pinkerton, A.C.; Coates, C.J.; Atkinson, P.W.

1998-01-01

Using genetic and physical methods we discovered short-inverted repeat type transposable elements in non-drosophilid insects including, Bactorcera tryoni, Musca domestica, Musca vetustissima and Lucilia cuprina. These elements are related to hobo, Ac and Tam3. The Hermes element from M domestica is 2749 bp in length and has terminal inverted repeats and a transposase coding region very similar to those in hobo. Hermes is functional in M Domestic and can act as a gene vector in this species. When Hermes is introduced into D. melanogaster it is hyperactive, relative to existing vector systems used in this species. Hermes will be useful as a gene vector. (author)

A novel binary T-vector with the GFP reporter gene for promoter characterization.

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Shu-Ye Jiang

Full Text Available Several strategies have been developed to clone PCR fragments into desired vectors. However, most of commercially available T-vectors are not binary vectors and cannot be directly used for Agrobacterium-mediated plant genetic transformation. In this study, a novel binary T-vector was constructed by integrating two AhdI restriction sites into the backbone vector pCAMBIA 1300. The T-vector also contains a GFP reporter gene and thus, can be used to analyze promoter activity by monitoring the reporter gene. On the other hand, identification and characterization of various promoters not only benefit the functional annotation of their genes but also provide alternative candidates to be used to drive interesting genes for plant genetic improvement by transgenesis. More than 1,000 putative pollen-specific rice genes have been identified in a genome-wide level. Among them, 67 highly expressed genes were further characterized. One of the pollen-specific genes LOC_Os10g35930 was further surveyed in its expression patterns with more details by quantitative real-time reverse-transcription PCR (qRT-PCR analysis. Finally, its promoter activity was further investigated by analyzing transgenic rice plants carrying the promoter::GFP cassette, which was constructed from the newly developed T-vector. The reporter GFP gene expression in these transgenic plants showed that the promoter was active only in mature but not in germinated pollens.

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

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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

Targeted, homology-driven gene insertion in stem cells by ZFN-loaded 'all-in-one' lentiviral vectors

DEFF Research Database (Denmark)

Cai, Yujia; Laustsen, Anders; Zhou, Yan

2016-01-01

-driven mechanism into safe loci. This insertion mechanism is driven by time-restricted exposure of treated cells to ZFNs. We show targeted gene integration in human stem cells, including CD34+ hematopoietic progenitors and induced pluripotent stem cells (iPSCs). Notably, targeted insertions are identified in 89......% of transduced iPSCs. Our findings demonstrate the applicability of nuclease-loaded 'all-in-one' IDLVs for site-directed gene insertion in stem cell based gene therapies....

Comparative genomic analysis of Drosophila melanogaster and vector mosquito developmental genes.

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Susanta K Behura

Full Text Available Genome sequencing projects have presented the opportunity for analysis of developmental genes in three vector mosquito species: Aedes aegypti, Culex quinquefasciatus, and Anopheles gambiae. A comparative genomic analysis of developmental genes in Drosophila melanogaster and these three important vectors of human disease was performed in this investigation. While the study was comprehensive, special emphasis centered on genes that 1 are components of developmental signaling pathways, 2 regulate fundamental developmental processes, 3 are critical for the development of tissues of vector importance, 4 function in developmental processes known to have diverged within insects, and 5 encode microRNAs (miRNAs that regulate developmental transcripts in Drosophila. While most fruit fly developmental genes are conserved in the three vector mosquito species, several genes known to be critical for Drosophila development were not identified in one or more mosquito genomes. In other cases, mosquito lineage-specific gene gains with respect to D. melanogaster were noted. Sequence analyses also revealed that numerous repetitive sequences are a common structural feature of Drosophila and mosquito developmental genes. Finally, analysis of predicted miRNA binding sites in fruit fly and mosquito developmental genes suggests that the repertoire of developmental genes targeted by miRNAs is species-specific. The results of this study provide insight into the evolution of developmental genes and processes in dipterans and other arthropods, serve as a resource for those pursuing analysis of mosquito development, and will promote the design and refinement of functional analysis experiments.

In situ preparation of magnetic nonviral gene vectors and magnetofection in vitro

International Nuclear Information System (INIS)

Shi Yunfeng; Pang Yan; Su Yue; Zhu Xinyuan; Yan Deyue; Zhou Linzhu; Xiao Wangchuan; Wang Xiaoliang; Gu Hongchen; Wang Ruibin; Li Huiqin; Zhu Bangshang

2010-01-01

Magnetic nonviral gene vectors were in situ prepared in the presence of ferrous salts and hyperbranched poly(ethylenimine)s (HPEI) with different molecular weights. HPEI, one of the most promising nonviral vectors, was not only utilized as the nanoreactor and stabilizer to prepare magnetic nanoparticles, but also skillfully used as a base supplier to avoid introducing alkali hydroxide or ammonia. Magnetic nonviral gene vectors with various magnetite contents and saturation magnetizations were obtained by changing the weight ratio of HPEI to FeSO 4 ·7H 2 O and the molecular weight of HPEI. MTT assays suggested that the resulting magnetite/HPEI gene vectors had lower cytotoxicity compared with pure HPEI. The magnetite/HPEI nonviral gene vectors were used for magnetofection. It was found that the luciferase expression level mediated by magnetite/HPEI in COS-7 cells under a magnetic gradient field was approximately 13-fold greater than that of standard HPEI transfection.

Sleeping Beauty-baculovirus hybrid vectors for long-term gene expression in the eye.

Science.gov (United States)

Turunen, Tytteli Anni Kaarina; Laakkonen, Johanna Päivikki; Alasaarela, Laura; Airenne, Kari Juhani; Ylä-Herttuala, Seppo

2014-01-01

A baculovirus vector is capable of efficiently transducing many nondiving and diving cell types. However, the potential of baculovirus is restricted for many gene delivery applications as a result of the transient gene expression that it mediates. The plasmid-based Sleeping Beauty (SB) transposon system integrates transgenes into target cell genome efficiently with a genomic integration pattern that is generally considered safer than the integration of many other integrating vectors; yet efficient delivery of therapeutic genes into cells of target tissues in vivo is a major challenge for nonviral gene therapy. In the present study, SB was introduced into baculovirus to obtain novel hybrid vectors that would combine the best features of the two vector systems (i.e. effective gene delivery and efficient integration into the genome), thus circumventing the major limitations of these vectors. We constructed and optimized SB-baculovirus hybrid vectors that bear either SB100x transposase or SB transposon in the forward or reverse orientations with respect to the viral backbone The functionality of the novel hybrid vectors was investigated in cell cultures and in a proof-of-concept study in the mouse eye. The hybrid vectors showed high and sustained transgene expression that remained stable and demonstrated no signs of decline during the 2 months follow-up in vitro. These results were verified in the mouse eye where persistent transgene expression was detected two months after intravitreal injection. Our results confirm that (i) SB-baculovirus hybrid vectors mediate long-term gene expression in vitro and in vivo, and (ii) the hybrid vectors are potential new tools for the treatment of ocular diseases. Copyright © 2014 John Wiley & Sons, Ltd.

Malaria Prevention by New Technology: Vectored Delivery of Antibody Genes

Science.gov (United States)

2017-10-01

AWARD NUMBER: W81XWH-15-1-0401 TITLE: Malaria Prevention by New Technology : Vectored Delivery of Antibody Genes PRINCIPAL INVESTIGATOR: Gary...CONTRACT NUMBER Malaria Prevention by New Technology : Vectored Delivery of Antibody Genes 5b. GRANT NUMBER W81XWH-15-1-0401 5c. PROGRAM ELEMENT...whole animals. Using a specific technology originally applied to expression of HIV antibodies, we demonstrated that mice can be protected from

Scalable Electrophysiological Investigation of iPS Cell-Derived Cardiomyocytes Obtained by a Lentiviral Purification Strategy

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Stephanie Friedrichs

2015-01-01

Full Text Available Disease-specific induced pluripotent stem (iPS cells can be generated from patients and differentiated into functional cardiomyocytes for characterization of the disease and for drug screening. In order to obtain pure cardiomyocytes for automated electrophysiological investigation, we here report a novel non-clonal purification strategy by using lentiviral gene transfer of a puromycin resistance gene under the control of a cardiac-specific promoter. We have applied this method to our previous reported wild-type and long QT syndrome 3 (LQTS 3-specific mouse iPS cells and obtained a pure cardiomyocyte population. These cells were investigated by action potential analysis with manual and automatic planar patch clamp technologies, as well as by recording extracellular field potentials using a microelectrode array system. Action potentials and field potentials showed the characteristic prolongation at low heart rates in LQTS 3-specific, but not in wild-type iPS cell-derived cardiomyocytes. Hence, LQTS 3-specific cardiomyocytes can be purified from iPS cells with a lentiviral strategy, maintain the hallmarks of the LQTS 3 disease and can be used for automated electrophysiological characterization and drug screening.

An efficient marker-free vector for clean gene transfer into plants ...

African Journals Online (AJOL)

A marker-free vector, pBINMF, for clean gene transfer was constructed based on the binary vector pBINPLUS. Vector pBINMF, carrying only a multiple cloning site (MCS) between the left and the right T-DNA border, was suitable to directly generate marker-free transgenic plants (MFTPs) without any vector sequences ...

Elimination of contaminating cap genes in AAV vector virions reduces immune responses and improves transgene expression in a canine gene therapy model.

Science.gov (United States)

Wang, Z; Halbert, C L; Lee, D; Butts, T; Tapscott, S J; Storb, R; Miller, A D

2014-04-01

Animal and human gene therapy studies utilizing AAV vectors have shown that immune responses to AAV capsid proteins can severely limit transgene expression. The main source of capsid antigen is that associated with the AAV vectors, which can be reduced by stringent vector purification. A second source of AAV capsid proteins is that expressed from cap genes aberrantly packaged into AAV virions during vector production. This antigen source can be eliminated by the use of a cap gene that is too large to be incorporated into an AAV capsid, such as a cap gene containing a large intron (captron gene). Here, we investigated the effects of elimination of cap gene transfer and of vector purification by CsCl gradient centrifugation on AAV vector immunogenicity and expression following intramuscular injection in dogs. We found that both approaches reduced vector immunogenicity and that combining the two produced the lowest immune responses and highest transgene expression. This combined approach enabled the use of a relatively mild immunosuppressive regimen to promote robust micro-dystrophin gene expression in Duchenne muscular dystrophy-affected dogs. Our study shows the importance of minimizing AAV cap gene impurities and indicates that this improvement in AAV vector production may benefit human applications.

Radiochemotherapy of hepatocarcinoma via lentivirus-mediated transfer of human sodium iodide symporter gene and herpes simplex virus thymidine kinase gene

Energy Technology Data Exchange (ETDEWEB)

Chen Libo, E-mail: libochen888@hotmail.com [Department of Nuclear Medicine, Shanghai Sixth People' s Hospital, Shanghai Jiao Tong University, Shanghai 200233 (China); Guo Guoying [Xinyuan Institute of Medicine and Biotechnology, School of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Liu Tianjing; Guo Lihe [Division of Biochemistry and Cell Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China); Zhu Ruisen [Department of Nuclear Medicine, Shanghai Sixth People' s Hospital, Shanghai Jiao Tong University, Shanghai 200233 (China)

2011-07-15

Herpes simplex virus thymidine kinase (HSV-TK) gene/ganciclovir (GCV) system has been widely used as a traditional gene therapy modality, and the sodium/iodide symporter gene (NIS) has been found to be a novel therapeutic gene. Since the therapeutic effects of radioiodine therapy or prodrug chemotherapy on cancers following NIS or HSV-TK gene transfer need to be enhanced, this study was designed to investigate the feasibility of radiochemotherapy for hepatocarcinoma via coexpression of NIS gene and HSV-TK gene. Methods: HepG2 cells were stably transfected with NIS, TK and GFP gene via recombinant lentiviral vector and named HepG2/NTG. Gene expression was examined by reverse transcriptase polymerase chain reaction, fluorescence imaging and iodide uptake. The therapeutic effects were assessed by MTT assay and clonogenic assay. Results: HepG2/NTG cells concentrated {sup 125}I{sup -} up to 76-fold higher than the wild-type cells within 20 min, and the efflux happened with a T{sub 1/2eff} of less than 10 min. The iodide uptake in HepG2/NTG cells was specifically inhibited by sodium perchlorate. Dose-dependent toxicity to HepG2/NTG cells by either GCV or {sup 131}I was revealed by clonogenic assay and MTT assay, respectively. The survival rate of HepG2/NTG cells decreased to 49.7%{+-}2.5%, 43.4%{+-}2.8% and 8.6%{+-}1.2% after exposure to {sup 131}I, GCV and combined therapy, respectively. Conclusion: We demonstrate that radiochemotherapy of hepatocarcinoma via lentiviral-mediated coexpression of NIS gene and HSV-TK gene leads to stronger killing effect than single treatment, and in vivo studies are needed to verify these findings.

Radiochemotherapy of hepatocarcinoma via lentivirus-mediated transfer of human sodium iodide symporter gene and herpes simplex virus thymidine kinase gene

International Nuclear Information System (INIS)

Chen Libo; Guo Guoying; Liu Tianjing; Guo Lihe; Zhu Ruisen

2011-01-01

Herpes simplex virus thymidine kinase (HSV-TK) gene/ganciclovir (GCV) system has been widely used as a traditional gene therapy modality, and the sodium/iodide symporter gene (NIS) has been found to be a novel therapeutic gene. Since the therapeutic effects of radioiodine therapy or prodrug chemotherapy on cancers following NIS or HSV-TK gene transfer need to be enhanced, this study was designed to investigate the feasibility of radiochemotherapy for hepatocarcinoma via coexpression of NIS gene and HSV-TK gene. Methods: HepG2 cells were stably transfected with NIS, TK and GFP gene via recombinant lentiviral vector and named HepG2/NTG. Gene expression was examined by reverse transcriptase polymerase chain reaction, fluorescence imaging and iodide uptake. The therapeutic effects were assessed by MTT assay and clonogenic assay. Results: HepG2/NTG cells concentrated 125 I - up to 76-fold higher than the wild-type cells within 20 min, and the efflux happened with a T 1/2eff of less than 10 min. The iodide uptake in HepG2/NTG cells was specifically inhibited by sodium perchlorate. Dose-dependent toxicity to HepG2/NTG cells by either GCV or 131 I was revealed by clonogenic assay and MTT assay, respectively. The survival rate of HepG2/NTG cells decreased to 49.7%±2.5%, 43.4%±2.8% and 8.6%±1.2% after exposure to 131 I, GCV and combined therapy, respectively. Conclusion: We demonstrate that radiochemotherapy of hepatocarcinoma via lentiviral-mediated coexpression of NIS gene and HSV-TK gene leads to stronger killing effect than single treatment, and in vivo studies are needed to verify these findings.

Reporter gene expression in fish following cutaneous infection with pantropic retroviral vectors.

Science.gov (United States)

Paul, T A; Burns, J C; Shike, H; Getchell, R; Bowser, P R; Whitlock, K E; Casey, J W

2001-06-01

A central issue in gene delivery systems is choosing promoters that will direct defined and sustainable levels of gene expression. Pantropic retroviral vectors provide a means to insert genes into either somatic or germline cells. In this study, we focused on somatic cell infection by evaluating the activity of 3 promoters inserted by vectors into fish cell lines and fish skin using pantropic retroviruses. In bluegill and zebrafish cell lines, the highest levels of luciferase expression were observed from the 5' murine leukemia virus long terminal repeat of the retroviral vector. The Rous sarcoma virus long terminal repeat and cytomegalovirus early promoter, as internal promoters, generated lower levels of luciferase. Luciferase reporter vectors infected zebrafish skin, as measured by the presence of viral DNA, and expressed luciferase. We infected developing walleye dermal sarcomas with retroviral vectors to provide an environment with enhanced cell proliferation, a condition necessary for integration of the provirus into the host genome. We demonstrated a 4-fold to 7-fold increase in luciferase gene expression in tumor tissue over infections in normal walleye skin.

Glycoprotein is enough for sindbis virus-derived DNA vector to express heterogenous genes

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Fu Juanjuan

2011-07-01

Full Text Available Abstract To investigate the necessity and potential application of structural genes for expressing heterogenous genes from Sindbis virus-derived vector, the DNA-based expression vector pVaXJ was constructed by placing the recombinant genome of sindbis-like virus XJ-160 under the control of the human cytomegalovirus (CMV promoter of the plasmid pVAX1, in which viral structural genes were replaced by a polylinker cassette to allow for insertion of heterologous genes. The defect helper plasmids pVaE or pVaC were developed by cloning the gene of glycoprotein E3E26KE1 or capsid protein of XJ-160 virus into pVAX1, respectively. The report gene cassette pVaXJ-EGFP or pV-Gluc expressing enhanced green fluorescence protein (EGFP or Gaussia luciferase (G.luc were constructed by cloning EGFP or G.luc gene into pVaXJ. EGFP or G.luc was expressed in the BHK-21 cells co-transfected with report gene cassettes and pVaE at levels that were comparable to those produced by report gene cassettes, pVaC and pVaE and were much higher than the levels produced by report gene cassette and pVaC, suggesting that glycoprotein is enough for Sindbis virus-derived DNA vector to express heterogenous genes in host cells. The method of gene expression from Sindbis virus-based DNA vector only co-transfected with envelop E gene increase the conveniency and the utility of alphavirus-based vector systems in general.

Efficient gene transfer into nondividing cells by adeno-associated virus-based vectors.

Science.gov (United States)

Podsakoff, G; Wong, K K; Chatterjee, S

1994-09-01

Gene transfer vectors based on adeno-associated virus (AAV) are emerging as highly promising for use in human gene therapy by virtue of their characteristics of wide host range, high transduction efficiencies, and lack of cytopathogenicity. To better define the biology of AAV-mediated gene transfer, we tested the ability of an AAV vector to efficiently introduce transgenes into nonproliferating cell populations. Cells were induced into a nonproliferative state by treatment with the DNA synthesis inhibitors fluorodeoxyuridine and aphidicolin or by contact inhibition induced by confluence and serum starvation. Cells in logarithmic growth or DNA synthesis arrest were transduced with vCWR:beta gal, an AAV-based vector encoding beta-galactosidase under Rous sarcoma virus long terminal repeat promoter control. Under each condition tested, vCWR:beta Gal expression in nondividing cells was at least equivalent to that in actively proliferating cells, suggesting that mechanisms for virus attachment, nuclear transport, virion uncoating, and perhaps some limited second-strand synthesis of AAV vectors were present in nondividing cells. Southern hybridization analysis of vector sequences from cells transduced while in DNA synthetic arrest and expanded after release of the block confirmed ultimate integration of the vector genome into cellular chromosomal DNA. These findings may provide the basis for the use of AAV-based vectors for gene transfer into quiescent cell populations such as totipotent hematopoietic stem cells.

Preparation and characterization of magnetic gene vectors for targeting gene delivery

Energy Technology Data Exchange (ETDEWEB)

Zheng, S.W.; Liu, G. [College of Chemistry, Chemical Engineering and Materials Science and Key Laboratory of Organic Synthesis of Jiangsu Province, Soochow University, SIP, Suzhou 215123 (China); Hong, R.Y., E-mail: rhong@suda.edu.cn [College of Chemistry, Chemical Engineering and Materials Science and Key Laboratory of Organic Synthesis of Jiangsu Province, Soochow University, SIP, Suzhou 215123 (China); State Key Laboratory of Multi-phase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100080 (China); Li, H.Z. [State Key Laboratory of Multi-phase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100080 (China); Li, Y.G., E-mail: ilguoliang@sohu.com [Department of radiology, the First Affiliated Hospital of Soochow University, Suzhou 215007 (China); Wei, D.G., E-mail: dougwei@deas.harvard.edu [Center for Nanoscale Systems, School of Engineering and Applied Science, Harvard University, 11 Oxford Street, Cambridge, MA 02139 (United States)

2012-10-15

Highlights: Black-Right-Pointing-Pointer PEI is ideal candidate polymer for the design of gene delivery systems. Black-Right-Pointing-Pointer PEI-CMD-MNPs exhibited a typical superparamagnetic behavior. Black-Right-Pointing-Pointer PEI-CMD-MNPs were well stable over the entire range of pH and NaCl concentration. Black-Right-Pointing-Pointer DNA-PEI-CMD-MNPs transfected cells by a magnet have higher transfection efficiency and gene expression efficiency. - Abstract: The PEI-CMD-MNPs were successfully prepared by the surface modification of magnetic Fe{sub 3}O{sub 4} nanoparticles with carboxymethyl dextran (CMD) and polyethyleneimine (PEI). The PEI-CMD-MNPs polyplexes exhibited a typical superparamagnetic behavior and were well stable over the entire range of pH and NaCl concentration. These PEI-CMD-MNPs were used as magnetic gene vectors for targeting gene delivery. The prepared MNPs at different surface modification stages were characterized using Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), field emissions canning electron microscopy (FE-SEM), powder X-ray diffraction (XRD) and dynamic laser light scattering (DLS) analysis. The magnetic properties were studied by vibrating sample magnetometer (VSM). To evaluate the performance of the magnetic nanoparticles as gene transfer vector, the PEI-CMD-MNPs were used to delivery green fluorescent protein (GFP) gene into BHK21 cells. The expression of GFP gene was detected by fluorescence microscope. DNA-PEI-CMD-MNPs polyplexes absorbed by the cells were also monitored by Magnetic resonance imaging (MRI). The transfection efficiency and gene expression efficiency of that transfected with a magnet were much higher than that of standard transfection.

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.

Three gene expression vector sets for concurrently expressing multiple genes in Saccharomyces cerevisiae.

Science.gov (United States)

Ishii, Jun; Kondo, Takashi; Makino, Harumi; Ogura, Akira; Matsuda, Fumio; Kondo, Akihiko

2014-05-01

Yeast has the potential to be used in bulk-scale fermentative production of fuels and chemicals due to its tolerance for low pH and robustness for autolysis. However, expression of multiple external genes in one host yeast strain is considerably labor-intensive due to the lack of polycistronic transcription. To promote the metabolic engineering of yeast, we generated systematic and convenient genetic engineering tools to express multiple genes in Saccharomyces cerevisiae. We constructed a series of multi-copy and integration vector sets for concurrently expressing two or three genes in S. cerevisiae by embedding three classical promoters. The comparative expression capabilities of the constructed vectors were monitored with green fluorescent protein, and the concurrent expression of genes was monitored with three different fluorescent proteins. Our multiple gene expression tool will be helpful to the advanced construction of genetically engineered yeast strains in a variety of research fields other than metabolic engineering. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Long-term preservation of retinal function in the RCS rat model of retinitis pigmentosa following lentivirus-mediated gene therapy.

Science.gov (United States)

Tschernutter, M; Schlichtenbrede, F C; Howe, S; Balaggan, K S; Munro, P M; Bainbridge, J W B; Thrasher, A J; Smith, A J; Ali, R R

2005-04-01

The Royal College of Surgeons (RCS) rat is a well-characterized model of autosomal recessive retinitis pigmentosa (RP) due to a defect in the retinal pigment epithelium (RPE). It is homozygous for a null mutation in the gene encoding , a receptor tyrosine kinase found in RPE cells, that is required for phagocytosis of shed photoreceptor outer segments. The absence of Mertk results in accumulation of outer segment debris. This subsequently leads to progressive loss of photoreceptor cells. In order to evaluate the efficacy of lentiviral-mediated gene replacement therapy in the RCS rat, we produced recombinant VSV-G pseudotyped HIV-1-based lentiviruses containing a murine Mertk cDNA driven by a spleen focus forming virus (SFFV) promoter. The vector was subretinally injected into the right eye of 10-day-old RCS rats; the left eye was left untreated as an internal control. Here, we present a detailed assessment of the duration and extent of the morphological rescue and the resulting functional benefits. We examined animals at various time points over a period of 7 months by light and electron microscopy, and electroretinography. We observed correction of the phagocytic defect, slowing of photoreceptor cell loss and preservation of retinal function for up to 7 months. This study demonstrates the potential of gene therapy approaches for the treatment of retinal degenerations caused by defects specific to the RPE and supports the use of lentiviral vectors for the treatment of such disorders.

Altering the selection capabilities of common cloning vectors via restriction enzyme mediated gene disruption

Science.gov (United States)

2013-01-01

Background The cloning of gene sequences forms the basis for many molecular biological studies. One important step in the cloning process is the isolation of bacterial transformants carrying vector DNA. This involves a vector-encoded selectable marker gene, which in most cases, confers resistance to an antibiotic. However, there are a number of circumstances in which a different selectable marker is required or may be preferable. Such situations can include restrictions to host strain choice, two phase cloning experiments and mutagenesis experiments, issues that result in additional unnecessary cloning steps, in which the DNA needs to be subcloned into a vector with a suitable selectable marker. Results We have used restriction enzyme mediated gene disruption to modify the selectable marker gene of a given vector by cloning a different selectable marker gene into the original marker present in that vector. Cloning a new selectable marker into a pre-existing marker was found to change the selection phenotype conferred by that vector, which we were able to demonstrate using multiple commonly used vectors and multiple resistance markers. This methodology was also successfully applied not only to cloning vectors, but also to expression vectors while keeping the expression characteristics of the vector unaltered. Conclusions Changing the selectable marker of a given vector has a number of advantages and applications. This rapid and efficient method could be used for co-expression of recombinant proteins, optimisation of two phase cloning procedures, as well as multiple genetic manipulations within the same host strain without the need to remove a pre-existing selectable marker in a previously genetically modified strain. PMID:23497512

Generation of X-CGD cells for vector evaluation from healthy donor CD34+ HSCs by shRNA-mediated knock down of gp91phox

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Christian Brendel

2014-01-01

Full Text Available Innovative approaches for the treatment of rare inherited diseases are hampered by limited availability of patient derived samples for preclinical research. This also applies for the evaluation of novel vector systems for the gene therapy of monogenic hematological diseases like X-linked chronic granulomatous disease (X-CGD, a severe primary immunodeficiency caused by mutations in the gp91phox subunit of the phagocytic NADPH oxidase. Since current gene therapy protocols involve ex vivo gene modification of autologous CD34+ hematopoietic stem cells (HSC, the ideal preclinical model should simulate faithfully this procedure. However, the low availability of patient-derived CD34+ cells limits the feasibility of this approach. Here, we describe a straightforward experimental strategy that circumvents this limitation. The knock down of gp91phox expression upon lentiviral delivery of shRNAs into CD34+ cells from healthy donors generates sufficient amounts of X-CGD CD34+ cells which subsequently can be used for the evaluation of novel gene therapeutic strategies using a codon-optimized gp91phox transgene. We have used this strategy to test the potential of a novel gene therapy vector for X-CGD.

Gene Transfer of Brain-derived Neurotrophic Factor (BDNF) Prevents Neurodegeneration Triggered by FXN Deficiency.

Science.gov (United States)

Katsu-Jiménez, Yurika; Loría, Frida; Corona, Juan Carlos; Díaz-Nido, Javier

2016-05-01

Friedreich's ataxia is a predominantly neurodegenerative disease caused by recessive mutations that produce a deficiency of frataxin (FXN). Here, we have used a herpesviral amplicon vector carrying a gene encoding for brain-derived neurotrophic factor (BDNF) to drive its overexpression in neuronal cells and test for its effect on FXN-deficient neurons both in culture and in the mouse cerebellum in vivo. Gene transfer of BDNF to primary cultures of mouse neurons prevents the apoptosis which is triggered by the knockdown of FXN gene expression. This neuroprotective effect of BDNF is also observed in vivo in a viral vector-based knockdown mouse cerebellar model. The injection of a lentiviral vector carrying a minigene encoding for a FXN-specific short hairpin ribonucleic acid (shRNA) into the mouse cerebellar cortex triggers a FXN deficit which is accompanied by significant apoptosis of granule neurons as well as loss of calbindin in Purkinje cells. These pathological changes are accompanied by a loss of motor coordination of mice as assayed by the rota-rod test. Coinjection of a herpesviral vector encoding for BDNF efficiently prevents both the development of cerebellar neuropathology and the ataxic phenotype. These data demonstrate the potential therapeutic usefulness of neurotrophins like BDNF to protect FXN-deficient neurons from degeneration.

A Foxtail mosaic virus Vector for Virus-Induced Gene Silencing in Maize.

Science.gov (United States)

Mei, Yu; Zhang, Chunquan; Kernodle, Bliss M; Hill, John H; Whitham, Steven A

2016-06-01

Plant viruses have been widely used as vectors for foreign gene expression and virus-induced gene silencing (VIGS). A limited number of viruses have been developed into viral vectors for the purposes of gene expression or VIGS in monocotyledonous plants, and among these, the tripartite viruses Brome mosaic virus and Cucumber mosaic virus have been shown to induce VIGS in maize (Zea mays). We describe here a new DNA-based VIGS system derived from Foxtail mosaic virus (FoMV), a monopartite virus that is able to establish systemic infection and silencing of endogenous maize genes homologous to gene fragments inserted into the FoMV genome. To demonstrate VIGS applications of this FoMV vector system, four genes, phytoene desaturase (functions in carotenoid biosynthesis), lesion mimic22 (encodes a key enzyme of the porphyrin pathway), iojap (functions in plastid development), and brown midrib3 (caffeic acid O-methyltransferase), were silenced and characterized in the sweet corn line Golden × Bantam. Furthermore, we demonstrate that the FoMV infectious clone establishes systemic infection in maize inbred lines, sorghum (Sorghum bicolor), and green foxtail (Setaria viridis), indicating the potential wide applications of this viral vector system for functional genomics studies in maize and other monocots. © 2016 American Society of Plant Biologists. All Rights Reserved.

Efficient gene transfer into nondividing cells by adeno-associated virus-based vectors.

OpenAIRE

Podsakoff, G; Wong, K K; Chatterjee, S

1994-01-01

Gene transfer vectors based on adeno-associated virus (AAV) are emerging as highly promising for use in human gene therapy by virtue of their characteristics of wide host range, high transduction efficiencies, and lack of cytopathogenicity. To better define the biology of AAV-mediated gene transfer, we tested the ability of an AAV vector to efficiently introduce transgenes into nonproliferating cell populations. Cells were induced into a nonproliferative state by treatment with the DNA synthe...

Effects of FVIII immunity on hepatocyte and hematopoietic stem cell–directed gene therapy of murine hemophilia A

Science.gov (United States)

Lytle, Allison M; Brown, Harrison C; Paik, Na Yoon; Knight, Kristopher A; Wright, J Fraser; Spencer, H Trent; Doering, Christopher B

2016-01-01

Immune responses to coagulation factors VIII (FVIII) and IX (FIX) represent primary obstacles to hemophilia treatment. Previously, we showed that hematopoietic stem cell (HSC) retroviral gene therapy induces immune nonresponsiveness to FVIII in both naive and preimmunized murine hemophilia A settings. Liver-directed adeno-associated viral (AAV)-FIX vector gene transfer achieved similar results in preclinical hemophilia B models. However, as clinical immune responses to FVIII and FIX differ, we investigated the ability of liver-directed AAV-FVIII gene therapy to affect FVIII immunity in hemophilia A mice. Both FVIII naive and preimmunized mice were administered recombinant AAV8 encoding a liver-directed bioengineered FVIII expression cassette. Naive animals receiving high or mid-doses subsequently achieved near normal FVIII activity levels. However, challenge with adjuvant-free recombinant FVIII induced loss of FVIII activity and anti-FVIII antibodies in mid-dose, but not high-dose AAV or HSC lentiviral (LV) vector gene therapy cohorts. Furthermore, unlike what was shown previously for FIX gene transfer, AAV-FVIII administration to hemophilia A inhibitor mice conferred no effect on anti-FVIII antibody or inhibitory titers. These data suggest that functional differences exist in the immune modulation achieved to FVIII or FIX in hemophilia mice by gene therapy approaches incorporating liver-directed AAV vectors or HSC-directed LV. PMID:26909355

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.

Gene editing in hematopoietic stem cells: a potential therapeutic approach for Fanconi anemia

International Nuclear Information System (INIS)

Diez Cabezas, B.

2015-01-01

Gene therapy nowadays constitutes a safe and efficient treatment for a number of monogenic diseases affecting the hematopoietic system. Risks of insertional mutagenesis derived from the use of integrative vectors cannot, however, be completely excluded. Therefore, gene targeting has been proposed as a safer alternative, since the insertion of the herapeutic gene is driven to a specific locus in the genome. Gene targeting approaches are based on the use of specific nucleases which generate double strand breaks (DSBs) in a specific site of the genome,markedly enhancing the efficacy of homologous recombination (HR) with donor constructs harboring the gene of interest flanked by the corresponding homology arms. In this study we have optimized the conditions to target human lymphoblastic cell lines (LCLs) and also hematopoietic stem cells (HSCs) from healthy donors, with the final aim of correcting by gene editing the hematopoietic progenitor cells from Fanconi anemia subtype A (FA-A) patients. In particular, we have established a robust method to target both LCLs and HSCs in a safe harbor site in the genome, the AAVS1 locus. Our approach is based on the transduction of these cells with integrase-defective lentiviral vectors carrying a donor with the gene of interest, followed by the nucleofection of these cells with zinc finger nucleases used as mRNA. Using a control donor vector carrying the GFP reporter gene we have obtained, on average, 9.43% gene targeting efficiency in cord blood CD34+ cells from healthy donors. Moreover, we confirmed that gene targeting was also efficient in HSCs with long term and multipotent repopulation capacity, as demonstrated by transplants into immunodeficient mice. To improve the gene targeting efficiency, we investigated the feasibility of using gold nanoparticles, which were shown to improve the transduction efficiency of integrase-defective and competent lentiviral vectors in HSCs. This increment, however, did not lead to a higher gene

Gene editing in hematopoietic stem cells: a potential therapeutic approach for Fanconi anemia

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Diez Cabezas, B.

2015-07-01

Gene therapy nowadays constitutes a safe and efficient treatment for a number of monogenic diseases affecting the hematopoietic system. Risks of insertional mutagenesis derived from the use of integrative vectors cannot, however, be completely excluded. Therefore, gene targeting has been proposed as a safer alternative, since the insertion of the herapeutic gene is driven to a specific locus in the genome. Gene targeting approaches are based on the use of specific nucleases which generate double strand breaks (DSBs) in a specific site of the genome,markedly enhancing the efficacy of homologous recombination (HR) with donor constructs harboring the gene of interest flanked by the corresponding homology arms. In this study we have optimized the conditions to target human lymphoblastic cell lines (LCLs) and also hematopoietic stem cells (HSCs) from healthy donors, with the final aim of correcting by gene editing the hematopoietic progenitor cells from Fanconi anemia subtype A (FA-A) patients. In particular, we have established a robust method to target both LCLs and HSCs in a safe harbor site in the genome, the AAVS1 locus. Our approach is based on the transduction of these cells with integrase-defective lentiviral vectors carrying a donor with the gene of interest, followed by the nucleofection of these cells with zinc finger nucleases used as mRNA. Using a control donor vector carrying the GFP reporter gene we have obtained, on average, 9.43% gene targeting efficiency in cord blood CD34+ cells from healthy donors. Moreover, we confirmed that gene targeting was also efficient in HSCs with long term and multipotent repopulation capacity, as demonstrated by transplants into immunodeficient mice. To improve the gene targeting efficiency, we investigated the feasibility of using gold nanoparticles, which were shown to improve the transduction efficiency of integrase-defective and competent lentiviral vectors in HSCs. This increment, however, did not lead to a higher gene

A novel co-crystal structure affords the design of gain-of-function lentiviral integrase mutants in the presence of modified PSIP1/LEDGF/p75.

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Stephen Hare

2009-01-01

Full Text Available Lens epithelium derived growth factor (LEDGF, also known as PC4 and SFRS1 interacting protein 1 (PSIP1 and transcriptional co-activator p75, is the cellular binding partner of lentiviral integrase (IN proteins. LEDGF accounts for the characteristic propensity of Lentivirus to integrate within active transcription units and is required for efficient viral replication. We now present a crystal structure containing the N-terminal and catalytic core domains (NTD and CCD of HIV-2 IN in complex with the IN binding domain (IBD of LEDGF. The structure extends the known IN-LEDGF interface, elucidating primarily charge-charge interactions between the NTD of IN and the IBD. A constellation of acidic residues on the NTD is characteristic of lentiviral INs, and mutations of the positively charged residues on the IBD severely affect interaction with all lentiviral INs tested. We show that the novel NTD-IBD contacts are critical for stimulation of concerted lentiviral DNA integration by LEDGF in vitro and for its function during the early steps of HIV-1 replication. Furthermore, the new structural details enabled us to engineer a mutant of HIV-1 IN that primarily functions only when presented with a complementary LEDGF mutant. These findings provide structural basis for the high affinity lentiviral IN-LEDGF interaction and pave the way for development of LEDGF-based targeting technologies for gene therapy.

Progress in developing cationic vectors for non-viral systemic gene therapy against cancer.

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Morille, Marie; Passirani, Catherine; Vonarbourg, Arnaud; Clavreul, Anne; Benoit, Jean-Pierre

2008-01-01

Initially, gene therapy was viewed as an approach for treating hereditary diseases, but its potential role in the treatment of acquired diseases such as cancer is now widely recognized. The understanding of the molecular mechanisms involved in cancer and the development of nucleic acid delivery systems are two concepts that have led to this development. Systemic gene delivery systems are needed for therapeutic application to cells inaccessible by percutaneous injection and for multi-located tumor sites, i.e. metastases. Non-viral vectors based on the use of cationic lipids or polymers appear to have promising potential, given the problems of safety encountered with viral vectors. Using these non-viral vectors, the current challenge is to obtain a similarly effective transfection to viral ones. Based on the advantages and disadvantages of existing vectors and on the hurdles encountered with these carriers, the aim of this review is to describe the "perfect vector" for systemic gene therapy against cancer.

Tailored HIV-1 vectors for genetic modification of primary human dendritic cells and monocytes.

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Durand, Stéphanie; Nguyen, Xuan-Nhi; Turpin, Jocelyn; Cordeil, Stephanie; Nazaret, Nicolas; Croze, Séverine; Mahieux, Renaud; Lachuer, Joël; Legras-Lachuer, Catherine; Cimarelli, Andrea

2013-01-01

Monocyte-derived dendritic cells (MDDCs) play a key role in the regulation of the immune system and are the target of numerous gene therapy applications. The genetic modification of MDDCs is possible with human immunodeficiency virus type 1 (HIV-1)-derived lentiviral vectors (LVs) but requires high viral doses to bypass their natural resistance to viral infection, and this in turn affects their physiological properties. To date, a single viral protein is able to counter this restrictive phenotype, Vpx, a protein derived from members of the HIV-2/simian immunodeficiency virus SM lineage that counters at least two restriction factors present in myeloid cells. By tagging Vpx with a short heterologous membrane-targeting domain, we have obtained HIV-1 LVs incorporating high levels of this protein (HIV-1-Src-Vpx). These vectors efficiently transduce differentiated MDDCs and monocytes either as previously purified populations or as populations within unsorted peripheral blood mononuclear cells (PBMCs). In addition, these vectors can be efficiently pseudotyped with receptor-specific envelopes, further restricting their cellular tropism almost uniquely to MDDCs. Compared to conventional HIV-1 LVs, these novel vectors allow for an efficient genetic modification of MDDCs and, more importantly, do not cause their maturation or affect their survival, which are unwanted side effects of the transduction process. This study describes HIV-1-Src-Vpx LVs as a novel potent tool for the genetic modification of differentiated MDDCs and of circulating monocyte precursors with strong potential for a wide range of gene therapy applications.

Evaluation of Lentiviral-Mediated Expression of Sodium Iodide Symporter in Anaplastic Thyroid Cancer and the Efficacy of In Vivo Imaging and Therapy

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Chien-Chih Ke

2011-01-01

Full Text Available Anaplastic thyroid carcinoma (ATC is one of the most deadly cancers. With intensive multimodalities of treatment, the survival remains low. ATC is not sensitive to 131I therapy due to loss of sodium iodide symporter (NIS gene expression. We have previously generated a stable human NIS-expressing ATC cell line, ARO, and the ability of iodide accumulation was restored. To make NIS-mediated gene therapy more applicable, this study aimed to establish a lentiviral system for transferring hNIS gene to cells and to evaluate the efficacy of in vitro and in vivo radioiodide accumulation for imaging and therapy. Lentivirus containing hNIS cDNA were produced to transduce ARO cells which do not concentrate iodide. Gene expression, cell function, radioiodide imaging and treatment were evaluated in vitro and in vivo. Results showed that the transduced cells were restored to express hNIS and accumulated higher amount of radioiodide than parental cells. Therapeutic dose of 131I effectively inhibited the tumor growth derived from transduced cells as compared to saline-treated mice. Our results suggest that the lentiviral system efficiently transferred and expressed hNIS gene in ATC cells. The transduced cells showed a promising result of tumor imaging and therapy.

Development of a gene silencing DNA vector derived from a broad host range geminivirus

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Hancock Leandria C

2009-07-01

Full Text Available Abstract Background Gene silencing is proving to be a powerful tool for genetic, developmental, and physiological analyses. The use of viral induced gene silencing (VIGS offers advantages to transgenic approaches as it can be potentially applied to non-model systems for which transgenic techniques are not readily available. However, many VIGS vectors are derived from Gemini viruses that have limited host ranges. We present a new, unipartite vector that is derived from a curtovirus that has a broad host range and will be amenable to use in many non-model systems. Results The construction of a gene silencing vector derived from the geminivirus Beet curly top virus (BCTV, named pWSRi, is reported. Two versions of the vector have been developed to allow application by biolistic techniques or by agro-infiltration. We demonstrate its ability to silence nuclear genes including ribulose bisphosphate carboxylase small subunit (rbcS, transketolase, the sulfur allele of magnesium chelatase (ChlI, and two homeotic transcription factors in spinach or tomato by generating gene-specific knock-down phenotypes. Onset of phenotypes occurred 3 to 12 weeks post-inoculation, depending on the target gene, in organs that developed after the application. The vector lacks movement genes and we found no evidence for significant spread from the site of inoculation. However, viral amplification in inoculated tissue was detected and is necessary for systemic silencing, suggesting that signals generated from active viral replicons are efficiently transported within the plant. Conclusion The unique properties of the pWSRi vector, the ability to silence genes in meristem tissue, the separation of virus and silencing phenotypes, and the broad natural host range of BCTV, suggest that it will have wide utility.

Neonatal Gene Therapy for Hemophilia B by a Novel Adenovirus Vector Showing Reduced Leaky Expression of Viral Genes.

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Iizuka, Shunsuke; Sakurai, Fuminori; Tachibana, Masashi; Ohashi, Kazuo; Mizuguchi, Hiroyuki

2017-09-15

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.

Cloning and Expression Vector Construction of Glutamate Decarboxylase Gene from Lactobacillus Plantarum

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B Arabpour

2016-06-01

Full Text Available BACKGROUND AND OBJECTIVE: Gamma-aminobutyric acid (GABA is a four-carbon non-protein amino acid used in the treatment of hypertension, diabetes, inflammation, and depression. GABA is synthesized by glutamic acid decarboxylase (GAD enzyme in many organisms, including bacteria. Therefore, cloning of this enzyme is essential to the optimization of GABA production. This study aimed to clone and construct the expression vector of GAD gene from Lactobacillus plantarum PTCC 1058 bacterium. METHODS: In this experimental study, we investigated the morphological, biochemical, genetic and 16s rDNA sequencing of L. plantarum PTCC 1058 strain. Genomic DNA of the bacterium was isolated and amplified using the GAD gene via polymerase chain reaction (PCR. Afterwards, the gene was inserted into the pJET1.2/blunt cloning vector and subcloned in vector pET32a. Plasmid pET32a-gad expression vector was transformed in Escherichia coli BL21 strain, and protein expression was assessed using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE. FINDINGS: Morphological, biochemical and genetic analyses of 16s rDNA sequencing indicated that the studied substrain was of the L. plantarum strain. In addition, results of nucleotide sequencing of the fragmented segment via PCR showed the presence of GAD gene. Results of colony PCR and SDS-PAGE analysis confirmed the accuracy of the cloning and gene expression of the recombinant Escherichia coli BL21 strain. CONCLUSION: According to the results of this study, cloning of GAD gene from L. plantarum PTCC 1058 was successful. These cloned genes could grow rapidly in prokaryotic and eukaryotic systems and be used in cost-effective culture media and even non-recyclable waste.

Effects of FVIII immunity on hepatocyte and hematopoietic stem cell–directed gene therapy of murine hemophilia A

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Allison M Lytle

2016-01-01

Full Text Available Immune responses to coagulation factors VIII (FVIII and IX (FIX represent primary obstacles to hemophilia treatment. Previously, we showed that hematopoietic stem cell (HSC retroviral gene therapy induces immune nonresponsiveness to FVIII in both naive and preimmunized murine hemophilia A settings. Liver-directed adeno-associated viral (AAV-FIX vector gene transfer achieved similar results in preclinical hemophilia B models. However, as clinical immune responses to FVIII and FIX differ, we investigated the ability of liver-directed AAV-FVIII gene therapy to affect FVIII immunity in hemophilia A mice. Both FVIII naive and preimmunized mice were administered recombinant AAV8 encoding a liver-directed bioengineered FVIII expression cassette. Naive animals receiving high or mid-doses subsequently achieved near normal FVIII activity levels. However, challenge with adjuvant-free recombinant FVIII induced loss of FVIII activity and anti-FVIII antibodies in mid-dose, but not high-dose AAV or HSC lentiviral (LV vector gene therapy cohorts. Furthermore, unlike what was shown previously for FIX gene transfer, AAV-FVIII administration to hemophilia A inhibitor mice conferred no effect on anti-FVIII antibody or inhibitory titers. These data suggest that functional differences exist in the immune modulation achieved to FVIII or FIX in hemophilia mice by gene therapy approaches incorporating liver-directed AAV vectors or HSC-directed LV.

Targeted Knock-Down of miR21 Primary Transcripts Using snoMEN Vectors Induces Apoptosis in Human Cancer Cell Lines.

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Motoharu Ono

Full Text Available We have previously reported an antisense technology, 'snoMEN vectors', for targeted knock-down of protein coding mRNAs using human snoRNAs manipulated to contain short regions of sequence complementarity with the mRNA target. Here we characterise the use of snoMEN vectors to target the knock-down of micro RNA primary transcripts. We document the specific knock-down of miR21 in HeLa cells using plasmid vectors expressing miR21-targeted snoMEN RNAs and show this induces apoptosis. Knock-down is dependent on the presence of complementary sequences in the snoMEN vector and the induction of apoptosis can be suppressed by over-expression of miR21. Furthermore, we have also developed lentiviral vectors for delivery of snoMEN RNAs and show this increases the efficiency of vector transduction in many human cell lines that are difficult to transfect with plasmid vectors. Transduction of lentiviral vectors expressing snoMEN targeted to pri-miR21 induces apoptosis in human lung adenocarcinoma cells, which express high levels of miR21, but not in human primary cells. We show that snoMEN-mediated suppression of miRNA expression is prevented by siRNA knock-down of Ago2, but not by knock-down of Ago1 or Upf1. snoMEN RNAs colocalise with Ago2 in cell nuclei and nucleoli and can be co-immunoprecipitated from nuclear extracts by antibodies specific for Ago2.

Targeted Knock-Down of miR21 Primary Transcripts Using snoMEN Vectors Induces Apoptosis in Human Cancer Cell Lines.

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Ono, Motoharu; Yamada, Kayo; Avolio, Fabio; Afzal, Vackar; Bensaddek, Dalila; Lamond, Angus I

2015-01-01

We have previously reported an antisense technology, 'snoMEN vectors', for targeted knock-down of protein coding mRNAs using human snoRNAs manipulated to contain short regions of sequence complementarity with the mRNA target. Here we characterise the use of snoMEN vectors to target the knock-down of micro RNA primary transcripts. We document the specific knock-down of miR21 in HeLa cells using plasmid vectors expressing miR21-targeted snoMEN RNAs and show this induces apoptosis. Knock-down is dependent on the presence of complementary sequences in the snoMEN vector and the induction of apoptosis can be suppressed by over-expression of miR21. Furthermore, we have also developed lentiviral vectors for delivery of snoMEN RNAs and show this increases the efficiency of vector transduction in many human cell lines that are difficult to transfect with plasmid vectors. Transduction of lentiviral vectors expressing snoMEN targeted to pri-miR21 induces apoptosis in human lung adenocarcinoma cells, which express high levels of miR21, but not in human primary cells. We show that snoMEN-mediated suppression of miRNA expression is prevented by siRNA knock-down of Ago2, but not by knock-down of Ago1 or Upf1. snoMEN RNAs colocalise with Ago2 in cell nuclei and nucleoli and can be co-immunoprecipitated from nuclear extracts by antibodies specific for Ago2.

Gene Therapy with Helper-Dependent Adenoviral Vectors: Current Advances and Future Perspectives

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Philip Ng

2010-09-01

Full Text Available Recombinant Adenoviral vectors represent one of the best gene transfer platforms due to their ability to efficiently transduce a wide range of quiescent and proliferating cell types from various tissues and species. The activation of an adaptive immune response against the transduced cells is one of the major drawbacks of first generation Adenovirus vectors and has been overcome by the latest generation of recombinant Adenovirus, the Helper-Dependent Adenoviral (HDAd vectors. HDAds have innovative features including the complete absence of viral coding sequences and the ability to mediate high level transgene expression with negligible chronic toxicity. This review summarizes the many aspects of HDAd biology and structure with a major focus on in vivo gene therapy application and with an emphasis on the unsolved issues that these vectors still presents toward clinical application.

Construction and applications of exon-trapping gene-targeting vectors with a novel strategy for negative selection.

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Saito, Shinta; Ura, Kiyoe; Kodama, Miho; Adachi, Noritaka

2015-06-30

Targeted gene modification by homologous recombination provides a powerful tool for studying gene function in cells and animals. In higher eukaryotes, non-homologous integration of targeting vectors occurs several orders of magnitude more frequently than does targeted integration, making the gene-targeting technology highly inefficient. For this reason, negative-selection strategies have been employed to reduce the number of drug-resistant clones associated with non-homologous vector integration, particularly when artificial nucleases to introduce a DNA break at the target site are unavailable or undesirable. As such, an exon-trap strategy using a promoterless drug-resistance marker gene provides an effective way to counterselect non-homologous integrants. However, constructing exon-trapping targeting vectors has been a time-consuming and complicated process. By virtue of highly efficient att-mediated recombination, we successfully developed a simple and rapid method to construct plasmid-based vectors that allow for exon-trapping gene targeting. These exon-trap vectors were useful in obtaining correctly targeted clones in mouse embryonic stem cells and human HT1080 cells. Most importantly, with the use of a conditionally cytotoxic gene, we further developed a novel strategy for negative selection, thereby enhancing the efficiency of counterselection for non-homologous integration of exon-trap vectors. Our methods will greatly facilitate exon-trapping gene-targeting technologies in mammalian cells, particularly when combined with the novel negative selection strategy.

Stable gene transfer of CCR5 and CXCR4 siRNAs by sleeping beauty transposon system to confer HIV-1 resistance

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Akkina Ramesh

2008-07-01

Full Text Available Abstract Background Thus far gene therapy strategies for HIV/AIDS have used either conventional retroviral vectors or lentiviral vectors for gene transfer. Although highly efficient, their use poses a certain degree of risk in terms of viral mediated oncogenesis. Sleeping Beauty (SB transposon system offers a non-viral method of gene transfer to avoid this possible risk. With respect to conferring HIV resistance, stable knock down of HIV-1 coreceptors CCR5 and CXCR4 by the use of lentiviral vector delivered siRNAs has proved to be a promising strategy to protect cells from HIV-1 infection. In the current studies our aim is to evaluate the utility of SB system for stable gene transfer of CCR5 and CXCR4 siRNA genes to derive HIV resistant cells as a first step towards using this system for gene therapy. Results Two well characterized siRNAs against the HIV-1 coreceptors CCR5 and CXCR4 were chosen based on their previous efficacy for the SB transposon gene delivery. The siRNA transgenes were incorporated individually into a modified SB transfer plasmid containing a FACS sortable red fluorescence protein (RFP reporter and a drug selectable neomycin resistance gene. Gene transfer was achieved by co-delivery with a construct expressing a hyperactive transposase (HSB5 into the GHOST-R3/X4/R5 cell line, which expresses the major HIV receptor CD4 and and the co-receptors CCR5 and CXCR4. SB constructs expressing CCR5 or CXCR4 siRNAs were also transfected into MAGI-CCR5 or MAGI-CXCR4 cell lines, respectively. Near complete downregulation of CCR5 and CXCR4 surface expression was observed in transfected cells. During viral challenge with X4-tropic (NL4.3 or R5-tropic (BaL HIV-1 strains, the respective transposed cells showed marked viral resistance. Conclusion SB transposon system can be used to deliver siRNA genes for stable gene transfer. The siRNA genes against HIV-1 coreceptors CCR5 and CXCR4 are able to downregulate the respective cell surface proteins

A new system for parallel drug screening against multiple-resistant HIV mutants based on lentiviral self-inactivating (SIN vectors and multi-colour analyses

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Prokofjeva Maria M

2013-01-01

Full Text Available Abstract Background Despite progress in the development of combined antiretroviral therapies (cART, HIV infection remains a significant challenge for human health. Current problems of cART include multi-drug-resistant virus variants, long-term toxicity and enormous treatment costs. Therefore, the identification of novel effective drugs is urgently needed. Methods We developed a straightforward screening approach for simultaneously evaluating the sensitivity of multiple HIV gag-pol mutants to antiviral drugs in one assay. Our technique is based on multi-colour lentiviral self-inactivating (SIN LeGO vector technology. Results We demonstrated the successful use of this approach for screening compounds against up to four HIV gag-pol variants (wild-type and three mutants simultaneously. Importantly, the technique was adapted to Biosafety Level 1 conditions by utilising ecotropic pseudotypes. This allowed upscaling to a large-scale screening protocol exploited by pharmaceutical companies in a successful proof-of-concept experiment. Conclusions The technology developed here facilitates fast screening for anti-HIV activity of individual agents from large compound libraries. Although drugs targeting gag-pol variants were used here, our approach permits screening compounds that target several different, key cellular and viral functions of the HIV life-cycle. The modular principle of the method also allows the easy exchange of various mutations in HIV sequences. In conclusion, the methodology presented here provides a valuable new approach for the identification of novel anti-HIV drugs.

CNS-restricted Transduction and CRISPR/Cas9-mediated Gene Deletion with an Engineered AAV Vector

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Giridhar Murlidharan

2016-01-01

Full Text Available Gene therapy using recombinant adeno-associated viral (AAV vectors is emerging as a promising approach to treat central nervous system disorders such as Spinal muscular atrophy, Batten, Parkinson and Alzheimer disease amongst others. A critical remaining challenge for central nervous system-targeted gene therapy, silencing or gene editing is to limit potential vector dose-related toxicity in off-target cells and organs. Here, we characterize a lab-derived AAV chimeric (AAV2g9, which displays favorable central nervous system attributes derived from both parental counterparts, AAV2 and AAV9. This synthetic AAV strain displays preferential, robust, and widespread neuronal transduction within the brain and decreased glial tropism. Importantly, we observed minimal systemic leakage, decreased sequestration and gene transfer in off-target organs with AAV2g9, when administered into the cerebrospinal fluid. A single intracranial injection of AAV2g9 vectors encoding guide RNAs targeting the schizophrenia risk gene MIR137 (encoding MIR137 in CRISPR/Cas9 knockin mice resulted in brain-specific gene deletion with no detectable events in the liver. This engineered AAV vector is a promising platform for treating neurological disorders through gene therapy, silencing or editing modalities.

A Foxtail mosaic virus Vector for Virus-Induced Gene Silencing in Maize1[OPEN

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Mei, Yu; Kernodle, Bliss M.; Hill, John H.

2016-01-01

Plant viruses have been widely used as vectors for foreign gene expression and virus-induced gene silencing (VIGS). A limited number of viruses have been developed into viral vectors for the purposes of gene expression or VIGS in monocotyledonous plants, and among these, the tripartite viruses Brome mosaic virus and Cucumber mosaic virus have been shown to induce VIGS in maize (Zea mays). We describe here a new DNA-based VIGS system derived from Foxtail mosaic virus (FoMV), a monopartite virus that is able to establish systemic infection and silencing of endogenous maize genes homologous to gene fragments inserted into the FoMV genome. To demonstrate VIGS applications of this FoMV vector system, four genes, phytoene desaturase (functions in carotenoid biosynthesis), lesion mimic22 (encodes a key enzyme of the porphyrin pathway), iojap (functions in plastid development), and brown midrib3 (caffeic acid O-methyltransferase), were silenced and characterized in the sweet corn line Golden × Bantam. Furthermore, we demonstrate that the FoMV infectious clone establishes systemic infection in maize inbred lines, sorghum (Sorghum bicolor), and green foxtail (Setaria viridis), indicating the potential wide applications of this viral vector system for functional genomics studies in maize and other monocots. PMID:27208311

In Vitro Generation of IL-35-expressing Human Wharton's Jelly-derived Mesenchymal Stem Cells Using Lentiviral Vector.

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Amari, Afshin; Ebtekar, Massoumeh; Moazzeni, Seyed Mohammad; Soleimani, Masoud; Mohammadi Amirabad, Leila; Tahoori, Mohammad Taher; Massumi, Mohammad

2015-08-01

Human Wharton's Jelly-derived Mesenchymal Stem Cells (hWJ-MSCs) are easily available cells without transplant rejection problems or ethical concerns compared to bone-marrow-derived MSCs for prospective clinical applications. These cells display immunosuppressive properties and may be able to play an important role in autoimmune disorders. Regulatory T-cells (Treg) are important to prevent autoimmune disease development. Interleukin 35 (IL-35) induces the proliferation of Treg cell populations and reduces the activity of T helper 17 (Th17) and T helper 1 (Th1) cells, which play a central role in initiation of inflammation and autoimmune disease. Recent studies identified IL-35 as a new inhibitory cytokine required for the suppressive function of Treg cells. We created IL-35-producing hWJ-MSCs as a good vehicle for reduction of inflammation and autoimmune diseases. We isolated hWJ-MSCs based on explant culture. HWJ-MSCs were transduced at MOI=50 (Multiplicity of Infection) with lentiviral particles harboring murine Interleukin 35 (mIL-35). Expression of IL-35 in hWJ-MSCs was quantified by an IL-35 ELISA kit. IL-35 bioactivity was analyzed by inhibiting the proliferation of mouse splenocytes using CFSE cell proliferation kit. Frequency of CD4+CD25+CD127 low/neg Foxp3+ Treg cells was measured by flow cytometry. There was an up to 85% GFP positive transduction rate, and the cells successfully released a high level of mIL-35 protein (750 ng/ml). IL-35 managed to inhibit CD4+ T cell proliferation with PHA, and improved the frequency of Treg cells. Our data suggest that transduced hWJ-MSCs overexpressing IL-35 may provide a useful approach for basic research on gene therapy for autoimmune disorders.

Novel approaches to models of Alzheimer's disease pathology for drug screening and development.

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Shaughnessy, Laura; Chamblin, Beth; McMahon, Lori; Nair, Ayyappan; Thomas, Mary Beth; Wakefield, John; Koentgen, Frank; Ramabhadran, Ram

2004-01-01

Development of therapeutics for Alzheimer's disease (AD) requires appropriate cell culture models that reflect the errant biochemical pathways and animal models that reflect the pathological hallmarks of the disease as well as the clinical manifestations. In the past two decades AD research has benefited significantly from the use of genetically engineered cell lines expressing components of the amyloid-generating pathway, as well as from the study of transgenic mice that develop the pathological hallmarks of the disease, mainly neuritic plaques. The choice of certain cell types and the choice of mouse as the model organism have been mandated by the feasibility of introduction and expression of foreign genes into these model systems. We describe a universal and efficient gene-delivery system, using lentiviral vectors, that permits the development of relevant cell biological systems using neuronal cells, including primary neurons and animal models in mammalian species best suited for the study of AD. In addition, lentiviral gene delivery provides avenues for creation of novel models by direct and prolonged expression of genes in the brain in any vertebrate animal. TranzVector is a lentiviral vector optimized for efficiency and safety that delivers genes to cells in culture, in tissue explants, and in live animals regardless of the dividing or differentiated status of the cells. Genes can also be delivered efficiently to fertilized single-cell-stage embryos of a wide range of mammalian species, broadening the range of the model organism (from rats to nonhuman primates) for the study of disease mechanism as well as for development of therapeutics. Copyright 2004 Humana Press Inc.

Genetic stability of gene targeted immunoglobulin loci. I. Heavy chain isotype exchange induced by a universal gene replacement vector.

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Kardinal, C; Selmayr, M; Mocikat, R

1996-11-01

Gene targeting at the immunoglobulin loci of B cells is an efficient tool for studying immunoglobulin expression or generating chimeric antibodies. We have shown that vector integration induced by human immunoglobulin G1 (IgG1) insertion vectors results in subsequent vector excision mediated by the duplicated target sequence, whereas replacement events which could be induced by the same constructs remain stable. We could demonstrate that the distribution of the vector homology strongly influences the genetic stability obtained. To this end we developed a novel type of a heavy chain replacement vector making use of the heavy chain class switch recombination sequence. Despite the presence of a two-sided homology this construct is universally applicable irrespective of the constant gene region utilized by the B cell. In comparison to an integration vector the frequency of stable incorporation was strongly increased, but we still observed vector excision, although at a markedly reduced rate. The latter events even occurred with circular constructs. Linearization of the construct at various sites and the comparison with an integration vector that carries the identical homology sequence, but differs in the distribution of homology, revealed the following features of homologous recombination of immunoglobulin genes: (i) the integration frequency is only determined by the length of the homology flank where the cross-over takes place; (ii) a 5' flank that does not meet the minimum requirement of homology length cannot be complemented by a sufficient 3' flank; (iii) free vector ends play a role for integration as well as for replacement targeting; (iv) truncating recombination events are suppressed in the presence of two flanks. Furthermore, we show that the switch region that was used as 3' flank is non-functional in an inverted orientation.

Detection of Replication Competent Lentivirus Using a qPCR Assay for VSV-G

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Lindsey M. Skrdlant

2018-03-01

Full Text Available Lentiviral vectors are a common tool used to introduce new and corrected genes into cell therapy products for treatment of human diseases. Although lentiviral vectors are ideal for delivery and stable integration of genes of interest into the host cell genome, they potentially pose risks to human health, such as integration-mediated transformation and generation of a replication competent lentivirus (RCL capable of infecting non-target cells. In consideration of the latter risk, all cell-based products modified by lentiviral vectors and intended for patient use must be tested for RCL prior to treatment of the patient. Current Food and Drug Administration (FDA guidelines recommend use of cell-based assays to this end, which can take up to 6 weeks for results. However, qPCR-based assays are a quick alternative for rapid assessment of RCL in products intended for fresh infusion. We describe here the development and qualification of a qPCR assay based on detection of envelope gene sequences (vesicular stomatitis virus G glycoprotein [VSV-G] for RCL in accordance with Minimum Information for Publication of Quantitative Real-Time PCR Experiments (MIQE guidelines. Our results demonstrate the sensitivity, linearity, specificity, and reproducibility of detection of VSV-G sequences, with a low false-positive rate. These procedures are currently being used in our phase 1 clinical investigations.

Analyzing the Genotoxicity of Retroviral Vectors in Hematopoietic Cell Gene Therapy

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Luca Biasco

2018-03-01

Full Text Available Retroviral vectors, including those derived from gammaretroviruses and lentiviruses, have found their way into the clinical arena and demonstrated remarkable efficacy for the treatment of immunodeficiencies, leukodystrophies, and globinopathies. Despite these successes, gene therapy unfortunately also has had to face severe adverse events in the form of leukemias and myelodysplastic syndromes, related to the semi-random vector integration into the host cell genome that caused deregulation of neighboring proto-oncogenes. Although improvements in vector design clearly lowered the risk of this insertional mutagenesis, analysis of potential genotoxicity and the consequences of vector integration remain important parameters for basic and translational research and most importantly for the clinic. Here, we review current assays to analyze biodistribution and genotoxicity in the pre-clinical setting and describe tools to monitor vector integration sites in vector-treated patients as a biosafety readout.

Preliminary studies on gene therapy with TGF β1 antisense gene/liposome complexes and adenovirus transfer vector in RPF rats

International Nuclear Information System (INIS)

Liu Chunjie; Wang Dewen; Zhang Zhaoshan; Gao Yabing; Xiong Chengqi; Long Jianyin; Wang Huixin; Peng Ruiyun; Cui Xuemei

2001-01-01

Objective: To observed the efficiency of gene therapy with TGF β1 antisense gene/liposome complexes and adenovirus transfer vector in RPF rats. Methods: TGFβ1 sense and antisense gene expression vectors and adenovirus transfer vector were introduced into rat bronchus by way of intratracheal instillation. Results: At day 1.5 after TGFβ1 sense and antisense gene transfer, PCR amplification using neo gene-specific primer from lung tissue DNA was all positive. After day 5.5, 67% (2/3) of lung tissue DNA was positive. RNA dot blot hybridization indicated that TGFβ1 mRNA content of lung tissue transfected with pMAMneo-antiTGFβ1 gene decreased. Detection of lung hydroxyproline (Hyp) content after day 35 of gene transfer showed that even in lung of rats received pMAMneo-AntiTGFβ1 lipid complexes it raised remarkably (P 9 pfu/ml were instilled into bronchus at 0.5 ml per rat. After day 2 day 6, the lung tissues of all six rats (three per each group )expressed the transfected luciferase gene by luminometer. Conclusion: Cationic lipid-mediated TGFβ1 antisense gene therapy was a simple and easy method. It can slow down the course of pathogenesis of lung fibrosis. Replication-deficient recombinant adenovirus-mediated gene therapy of lung diseases is a good and efficient method

Gene therapy for human glioblastoma using neurotropic JC virus-like particles as a gene delivery vector.

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Chao, Chun-Nun; Yang, Yu-Hsuan; Wu, Mu-Sheng; Chou, Ming-Chieh; Fang, Chiung-Yao; Lin, Mien-Chun; Tai, Chien-Kuo; Shen, Cheng-Huang; Chen, Pei-Lain; Chang, Deching; Wang, Meilin

2018-02-02

Glioblastoma multiforme (GBM), the most common malignant brain tumor, has a short period of survival even with recent multimodality treatment. The neurotropic JC polyomavirus (JCPyV) infects glial cells and oligodendrocytes and causes fatal progressive multifocal leukoencephalopathy in patients with AIDS. In this study, a possible gene therapy strategy for GBM using JCPyV virus-like particles (VLPs) as a gene delivery vector was investigated. We found that JCPyV VLPs were able to deliver the GFP reporter gene into tumor cells (U87-MG) for expression. In an orthotopic xenograft model, nude mice implanted with U87 cells expressing the near-infrared fluorescent protein and then treated by intratumoral injection of JCPyV VLPs carrying the thymidine kinase suicide gene, combined with ganciclovir administration, exhibited significantly prolonged survival and less tumor fluorescence during the experiment compared with controls. Furthermore, JCPyV VLPs were able to protect and deliver a suicide gene to distal subcutaneously implanted U87 cells in nude mice via blood circulation and inhibit tumor growth. These findings show that metastatic brain tumors can be targeted by JCPyV VLPs carrying a therapeutic gene, thus demonstrating the potential of JCPyV VLPs to serve as a gene therapy vector for the far highly treatment-refractory GBM.

Fetal muscle gene transfer is not enhanced by an RGD capsid modification to high-capacity adenoviral vectors.

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Bilbao, R; Reay, D P; Hughes, T; Biermann, V; Volpers, C; Goldberg, L; Bergelson, J; Kochanek, S; Clemens, P R

2003-10-01

High levels of alpha(v) integrin expression by fetal muscle suggested that vector re-targeting to integrins could enhance adenoviral vector-mediated transduction, thereby increasing safety and efficacy of muscle gene transfer in utero. High-capacity adenoviral (HC-Ad) vectors modified by an Arg-Gly-Asp (RGD) peptide motif in the HI loop of the adenoviral fiber (RGD-HC-Ad) have demonstrated efficient gene transfer through binding to alpha(v) integrins. To test integrin targeting of HC-Ad vectors for fetal muscle gene transfer, we compared unmodified and RGD-modified HC-Ad vectors. In vivo, unmodified HC-Ad vector transduced fetal mouse muscle with four-fold higher efficiency compared to RGD-HC-Ad vector. Confirming that the difference was due to muscle cell autonomous factors and not mechanical barriers, transduction of primary myogenic cells isolated from murine fetal muscle in vitro demonstrated a three-fold better transduction by HC-Ad vector than by RGD-HC-Ad vector. We hypothesized that the high expression level of coxsackievirus and adenovirus receptor (CAR), demonstrated in fetal muscle cells both in vitro and in vivo, was the crucial variable influencing the relative transduction efficiencies of HC-Ad and RGD-HC-Ad vectors. To explore this further, we studied transduction by HC-Ad and RGD-HC-Ad vectors in paired cell lines that expressed alpha(v) integrins and differed only by the presence or absence of CAR expression. The results increase our understanding of factors that will be important for retargeting HC-Ad vectors to enhance gene transfer to fetal muscle.

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.

Proviral HIV-genome-wide and pol-gene specific Zinc Finger Nucleases: Usability for targeted HIV gene therapy

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Wayengera Misaki

2011-07-01

Full Text Available Abstract Background Infection with HIV, which culminates in the establishment of a latent proviral reservoir, presents formidable challenges for ultimate cure. Building on the hypothesis that ex-vivo or even in-vivo abolition or disruption of HIV-gene/genome-action by target mutagenesis or excision can irreversibly abrogate HIV's innate fitness to replicate and survive, we previously identified the isoschizomeric bacteria restriction enzymes (REases AcsI and ApoI as potent cleavers of the HIV-pol gene (11 and 9 times in HIV-1 and 2, respectively. However, both enzymes, along with others found to cleave across the entire HIV-1 genome, slice (SX at palindromic sequences that are prevalent within the human genome and thereby pose the risk of host genome toxicity. A long-term goal in the field of R-M enzymatic therapeutics has thus been to generate synthetic restriction endonucleases with longer recognition sites limited in specificity to HIV. We aimed (i to assemble and construct zinc finger arrays and nucleases (ZFN with either proviral-HIV-pol gene or proviral-HIV-1 whole-genome specificity respectively, and (ii to advance a model for pre-clinically testing lentiviral vectors (LV that deliver and transduce either ZFN genotype. Methods and Results First, we computationally generated the consensus sequences of (a 114 dsDNA-binding zinc finger (Zif arrays (ZFAs or ZifHIV-pol and (b two zinc-finger nucleases (ZFNs which, unlike the AcsI and ApoI homeodomains, possess specificity to >18 base-pair sequences uniquely present within the HIV-pol gene (ZifHIV-polFN. Another 15 ZFNs targeting >18 bp sequences within the complete HIV-1 proviral genome were constructed (ZifHIV-1FN. Second, a model for constructing lentiviral vectors (LVs that deliver and transduce a diploid copy of either ZifHIV-polFN or ZifHIV-1FN chimeric genes (termed LV- 2xZifHIV-polFN and LV- 2xZifHIV-1FN, respectively is proposed. Third, two preclinical models for controlled testing of

Proviral HIV-genome-wide and pol-gene specific zinc finger nucleases: usability for targeted HIV gene therapy.

Science.gov (United States)

Wayengera, Misaki

2011-07-22

Infection with HIV, which culminates in the establishment of a latent proviral reservoir, presents formidable challenges for ultimate cure. Building on the hypothesis that ex-vivo or even in-vivo abolition or disruption of HIV-gene/genome-action by target mutagenesis or excision can irreversibly abrogate HIV's innate fitness to replicate and survive, we previously identified the isoschizomeric bacteria restriction enzymes (REases) AcsI and ApoI as potent cleavers of the HIV-pol gene (11 and 9 times in HIV-1 and 2, respectively). However, both enzymes, along with others found to cleave across the entire HIV-1 genome, slice (SX) at palindromic sequences that are prevalent within the human genome and thereby pose the risk of host genome toxicity. A long-term goal in the field of R-M enzymatic therapeutics has thus been to generate synthetic restriction endonucleases with longer recognition sites limited in specificity to HIV. We aimed (i) to assemble and construct zinc finger arrays and nucleases (ZFN) with either proviral-HIV-pol gene or proviral-HIV-1 whole-genome specificity respectively, and (ii) to advance a model for pre-clinically testing lentiviral vectors (LV) that deliver and transduce either ZFN genotype. First, we computationally generated the consensus sequences of (a) 114 dsDNA-binding zinc finger (Zif) arrays (ZFAs or ZifHIV-pol) and (b) two zinc-finger nucleases (ZFNs) which, unlike the AcsI and ApoI homeodomains, possess specificity to >18 base-pair sequences uniquely present within the HIV-pol gene (ZifHIV-polFN). Another 15 ZFNs targeting >18 bp sequences within the complete HIV-1 proviral genome were constructed (ZifHIV-1FN). Second, a model for constructing lentiviral vectors (LVs) that deliver and transduce a diploid copy of either ZifHIV-polFN or ZifHIV-1FN chimeric genes (termed LV- 2xZifHIV-polFN and LV- 2xZifHIV-1FN, respectively) is proposed. Third, two preclinical models for controlled testing of the safety and efficacy of either of these

African Journal of Biotechnology - Vol 9, No 13 (2010)

African Journals Online (AJOL)

Inheritance of fresh seed dormancy in Spanish-type peanut (Arachis ... Construction of a novel lentiviral vector carrying human B-domain-deleted factor VIII gene ... Studies on hemorrhagic pneumonia in Moschus sifanicus · EMAIL FREE FULL ...

Targeted gene therapy and cell reprogramming in Fanconi anemia

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Rio, Paula; Baños, Rocio; Lombardo, Angelo; Quintana-Bustamante, Oscar; Alvarez, Lara; Garate, Zita; Genovese, Pietro; Almarza, Elena; Valeri, Antonio; Díez, Begoña; Navarro, Susana; Torres, Yaima; Trujillo, Juan P; Murillas, Rodolfo; Segovia, Jose C; Samper, Enrique; Surralles, Jordi; Gregory, Philip D; Holmes, Michael C; Naldini, Luigi; Bueren, Juan A

2014-01-01

Gene targeting is progressively becoming a realistic therapeutic alternative in clinics. It is unknown, however, whether this technology will be suitable for the treatment of DNA repair deficiency syndromes such as Fanconi anemia (FA), with defects in homology-directed DNA repair. In this study, we used zinc finger nucleases and integrase-defective lentiviral vectors to demonstrate for the first time that FANCA can be efficiently and specifically targeted into the AAVS1 safe harbor locus in fibroblasts from FA-A patients. Strikingly, up to 40% of FA fibroblasts showed gene targeting 42 days after gene editing. Given the low number of hematopoietic precursors in the bone marrow of FA patients, gene-edited FA fibroblasts were then reprogrammed and re-differentiated toward the hematopoietic lineage. Analyses of gene-edited FA-iPSCs confirmed the specific integration of FANCA in the AAVS1 locus in all tested clones. Moreover, the hematopoietic differentiation of these iPSCs efficiently generated disease-free hematopoietic progenitors. Taken together, our results demonstrate for the first time the feasibility of correcting the phenotype of a DNA repair deficiency syndrome using gene-targeting and cell reprogramming strategies. PMID:24859981

Bacteria as vectors for gene therapy of cancer.

LENUS (Irish Health Repository)

Baban, Chwanrow K

2012-01-31

Anti-cancer therapy faces major challenges, particularly in terms of specificity of treatment. The ideal therapy would eradicate tumor cells selectively with minimum side effects on normal tissue. Gene or cell therapies have emerged as realistic prospects for the treatment of cancer, and involve the delivery of genetic information to a tumor to facilitate the production of therapeutic proteins. However, there is still much to be done before an efficient and safe gene medicine is achieved, primarily developing the means of targeting genes to tumors safely and efficiently. An emerging family of vectors involves bacteria of various genera. It has been shown that bacteria are naturally capable of homing to tumors when systemically administered resulting in high levels of replication locally. Furthermore, invasive species can deliver heterologous genes intra-cellularly for tumor cell expression. Here, we review the use of bacteria as vehicles for gene therapy of cancer, detailing the mechanisms of action and successes at preclinical and clinical levels.

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

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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.

Gene Therapy in Fanconi Anemia: A Matter of Time, Safety and Gene Transfer Tool Efficiency.

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Verhoeyen, Els; Roman-Rodriguez, Francisco Jose; Cosset, Francois-Loic; Levy, Camille; Rio, Paula

2017-01-01

Fanconi anemia (FA) is a rare genetic syndrome characterized by progressive marrow failure. Gene therapy by infusion of FA-corrected autologous hematopoietic stem cells (HSCs) may offer a potential cure since it is a monogenetic disease with mutations in the FANC genes, coding for DNA repair enzymes [1]. However, the collection of hCD34+-cells in FA patients implies particular challenges because of the reduced numbers of progenitor cells present in their bone marrow (BM) [2] or mobilized peripheral blood [3-5]. In addition, the FA genetic defect fragilizes the HSCs [6]. These particular features might explain why the first clinical trials using murine leukemia virus derived retroviral vectors conducted for FA failed to show engraftment of corrected cells. The gene therapy field is now moving towards the use of lentiviral vectors (LVs) evidenced by recent succesful clinical trials for the treatment of patients suffering from adrenoleukodystrophy (ALD) [7], β-thalassemia [8], metachromatic leukodystrophy [9] and Wiskott-Aldrich syndrome [10]. LV trials for X-linked severe combined immunodificiency and Fanconi anemia (FA) defects were recently initiated [11, 12]. Fifteen years of preclinical studies using different FA mouse models and in vitro research allowed us to find the weak points in the in vitro culture and transduction conditions, which most probably led to the initial failure of FA HSC gene therapy. In this review, we will focus on the different obstacles, unique to FA gene therapy, and how they have been overcome through the development of optimized protocols for FA HSC culture and transduction and the engineering of new gene transfer tools for FA HSCs. These combined advances in the field hopefully will allow the correction of the FA hematological defect in the near future. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Lentiviral-Mediated Transgene Expression Can Potentiate Intestinal Mesenchymal-Epithelial Signaling

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Kohn Aimee

2009-01-01

Full Text Available Abstract Mesenchymal-epithelial signaling is essential for the development of many organs and is often disrupted in disease. In this study, we demonstrate the use of lentiviral-mediated transgene delivery as an effective approach for ectopic transgene expression and an alternative to generation of transgenic animals. One benefit to this approach is that it can be used independently or in conjunction with established transgenic or knockout animals for studying modulation of mesenchymal-epithelial interactions. To display the power of this approach, we explored ectopic expression of a Wnt ligand in the mouse intestinal mesenchyme and demonstrate its functional influence on the adjacent epithelium. Our findings highlight the efficient use of lentiviral-mediated transgene expression for modulating mesenchymal-epithelial interactions in vivo.

Lentiviral-Mediated Transgene Expression Can Potentiate Intestinal Mesenchymal-Epithelial Signaling

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Dismuke Adria D

2009-07-01

Full Text Available Abstract Mesenchymal-epithelial signaling is essential for the development of many organs and is often disrupted in disease. In this study, we demonstrate the use of lentiviral-mediated transgene delivery as an effective approach for ectopic transgene expression and an alternative to generation of transgenic animals. One benefit to this approach is that it can be used independently or in conjunction with established transgenic or knockout animals for studying modulation of mesenchymal-epithelial interactions. To display the power of this approach, we explored ectopic expression of a Wnt ligand in the mouse intestinal mesenchyme and demonstrate its functional influence on the adjacent epithelium. Our findings highlight the efficient use of lentiviral-mediated transgene expression for modulating mesenchymal-epithelial interactions in vivo.

Gene Therapy Vectors with Enhanced Transfection Based on Hydrogels Modified with Affinity Peptides

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Shepard, Jaclyn A.; Wesson, Paul J.; Wang, Christine E.; Stevans, Alyson C.; Holland, Samantha J.; Shikanov, Ariella; Grzybowski, Bartosz A.; Shea, Lonnie D.

2011-01-01

Regenerative strategies for damaged tissue aim to present biochemical cues that recruit and direct progenitor cell migration and differentiation. Hydrogels capable of localized gene delivery are being developed to provide a support for tissue growth, and as a versatile method to induce the expression of inductive proteins; however, the duration, level, and localization of expression isoften insufficient for regeneration. We thus investigated the modification of hydrogels with affinity peptides to enhance vector retention and increase transfection within the matrix. PEG hydrogels were modified with lysine-based repeats (K4, K8), which retained approximately 25% more vector than control peptides. Transfection increased 5- to 15-fold with K8 and K4 respectively, over the RDG control peptide. K8- and K4-modified hydrogels bound similar quantities of vector, yet the vector dissociation rate was reduced for K8, suggesting excessive binding that limited transfection. These hydrogels were subsequently applied to an in vitro co-culture model to induce NGF expression and promote neurite outgrowth. K4-modified hydrogels promoted maximal neurite outgrowth, likely due to retention of both the vector and the NGF. Thus, hydrogels modified with affinity peptides enhanced vector retention and increased gene delivery, and these hydrogels may provide a versatile scaffold for numerous regenerative medicine applications. PMID:21514659

Generation of healthy mice from gene-corrected disease-specific induced pluripotent stem cells.

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Guangming Wu

2011-07-01

Full Text Available Using the murine model of tyrosinemia type 1 (fumarylacetoacetate hydrolase [FAH] deficiency; FAH⁻/⁻ mice as a paradigm for orphan disorders, such as hereditary metabolic liver diseases, we evaluated fibroblast-derived FAH⁻/⁻-induced pluripotent stem cells (iPS cells as targets for gene correction in combination with the tetraploid embryo complementation method. First, after characterizing the FAH⁻/⁻ iPS cell lines, we aggregated FAH⁻/⁻-iPS cells with tetraploid embryos and obtained entirely FAH⁻/⁻-iPS cell-derived mice that were viable and exhibited the phenotype of the founding FAH⁻/⁻ mice. Then, we transduced FAH cDNA into the FAH⁻/⁻-iPS cells using a third-generation lentiviral vector to generate gene-corrected iPS cells. We could not detect any chromosomal alterations in these cells by high-resolution array CGH analysis, and after their aggregation with tetraploid embryos, we obtained fully iPS cell-derived healthy mice with an astonishing high efficiency for full-term development of up to 63.3%. The gene correction was validated functionally by the long-term survival and expansion of FAH-positive cells of these mice after withdrawal of the rescuing drug NTBC (2-(2-nitro-4-fluoromethylbenzoyl-1,3-cyclohexanedione. Furthermore, our results demonstrate that both a liver-specific promoter (transthyretin, TTR-driven FAH transgene and a strong viral promoter (from spleen focus-forming virus, SFFV-driven FAH transgene rescued the FAH-deficiency phenotypes in the mice derived from the respective gene-corrected iPS cells. In conclusion, our data demonstrate that a lentiviral gene repair strategy does not abrogate the full pluripotent potential of fibroblast-derived iPS cells, and genetic manipulation of iPS cells in combination with tetraploid embryo aggregation provides a practical and rapid approach to evaluate the efficacy of gene correction of human diseases in mouse models.

PGMA-Based Cationic Nanoparticles with Polyhydric Iodine Units for Advanced Gene Vectors.

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Sun, Yue; Hu, Hao; Yu, Bingran; Xu, Fu-Jian

2016-11-16

It is crucial for successful gene delivery to develop safe, effective, and multifunctional polycations. Iodine-based small molecules are widely used as contrast agents for CT imaging. Herein, a series of star-like poly(glycidyl methacrylate) (PGMA)-based cationic vectors (II-PGEA/II) with abundant flanking polyhydric iodine units are prepared for multifunctional gene delivery systems. The proposed II-PGEA/II star vector is composed of one iohexol intermediate (II) core and five ethanolamine (EA) and II-difunctionalized PGMA arms. The amphipathic II-PGEA/II vectors readily self-assemble into well-defined cationic nanoparticles, where massive hydroxyl groups can establish a hydration shell to stabilize the nanoparticles. The II introduction improves cell viabilities of polycations. Moreover, by controlling the suitable amount of introduced II units, the resultant II-PGEA/II nanoparticles can produce fairly good transfection performances in different cell lines. Particularly, the II-PGEA/II nanoparticles induce much better in vitro CT imaging abilities in tumor cells than iohexol (one commonly used commercial CT contrast agent). The present design of amphipathic PGMA-based nanoparticles with CT contrast agents would provide useful information for the development of new multifunctional gene delivery systems.

Multicomponent nanoparticles as nonviral vectors for the treatment of Fabry disease by gene therapy

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Ruiz de Garibay AP

2012-10-01

Full Text Available Aritz Pérez Ruiz de Garibay, Diego Delgado, Ana del Pozo-Rodríguez, María Ángeles Solinís, Alicia Rodríguez GascónPharmacokinetics, Nanotechnology and Gene Therapy Group, Pharmacy Faculty, University of the Basque Country UPV/EHU, Vitoria-Gasteiz, SpainPurpose: Gene-mediated enzyme replacement is a reasonable and highly promising approach for the treatment of Fabry disease (FD. The objective of the present study was to demonstrate the potential applications of solid lipid nanoparticle (SLN-based nonviral vectors for the treatment of FD.Methods: SLNs containing the pR-M10-αGal A plasmid that encodes the α-Galactosidase A (α-Gal A enzyme were prepared and their in vitro transfection efficacy was studied in Hep G2 cells. We also studied the cellular uptake of the vectors and the intracellular disposition of the plasmid.Results: The enzymatic activity of the cells treated with the vectors increased significantly relative to the untreated cells, regardless of the formulation assayed. When the SLNs were prepared with protamine or dextran and protamine, the activity of the α-Gal A enzyme by the transfected Hep G2 cells increased up to 12-fold compared to that of untreated cells.Conclusion: With this work we have revealed in Hep G2 cells the ability of a multicomponent system based on SLNs to act as efficient nonviral vectors to potentially correct low α-Gal A activity levels in FD with gene therapy.Keywords: solid lipid nanoparticles, Fabry disease, nonviral vectors, gene therapy

Construction and identification of double-gene co-expression vector with radiation-inducible human TRAIL and endostatin

International Nuclear Information System (INIS)

Li Yanbo; Guo Caixia; Gong Pingsheng; Liu Yang; Liangshuo; Wang Hongfang; Wang Jianfeng; Gong Shouliang

2010-01-01

Objective: To construct a recombinant plasmid pshuttle-Egr1-shTRAIL-shES containing tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and endostatin double genes. Methods: The secretary endostatin gene (shES) fragment was amplified from the pMD19T-endostatin vector by PCR. The shES gene was ligated to pMD19Tand sequenced. Finally, using the gene recombinant technique, the recombinant plasmid pshuttle-Egr1- shTRAIL-shES with radiation-inducible Egr1 promoter, secretary TRAIL and endostatin double-gene was constructed. Results: The sequence of the shES gene was in concordance with that anticipated indicating shES gene was acquired successfully.Moreover, the results acquired by PCR and restrictive digestion identification of the recombinant plasmid pshuttle-Egr1-shTRAIL-shES and all the vectors refered to its construction confirmed that pshuttle-Egr1-shTRAIL-shES was constructed correctly. Conclusion: The radiation-inducible double-gene co-expression vector pshuttle-Egr1-shTRAIL-shES is constructed successfully, which would set the experimental foundation for further study on the anti-tumor effect of TRAIL and endostatin double-gene-radiotherapy and its related mechanisms. (authors)

Genetically engineering adenoviral vectors for gene therapy.

Science.gov (United States)

Coughlan, Lynda

2014-01-01

Adenoviral (Ad) vectors are commonly used for various gene therapy applications. Significant advances in the genetic engineering of Ad vectors in recent years has highlighted their potential for the treatment of metastatic disease. There are several methods to genetically modify the Ad genome to incorporate retargeting peptides which will redirect the natural tropism of the viruses, including homologous recombination in bacteria or yeast. However, homologous recombination in yeast is highly efficient and can be achieved without the need for extensive cloning strategies. In addition, the method does not rely on the presence of unique restriction sites within the Ad genome and the reagents required for this method are widely available and inexpensive. Large plasmids containing the entire adenoviral genome (~36 kbp) can be modified within Saccharomyces cerevisiae yeast and genomes easily rescued in Escherichia coli hosts for analysis or amplification. A method for two-step homologous recombination in yeast is described in this chapter.

'Molecular switch' vectors for hypoxia- and radiation-mediated gene therapy of cancer

International Nuclear Information System (INIS)

Greco, O.; Marples, B.; Joiner, M.C.; Scott, S.D.

2003-01-01

Intratumoral areas of low oxygen concentration are known to be refractive to radiotherapy treatment. However, this physiological condition can be exploited for selective cancer gene therapy. We have developed a series of synthetic promoters selectively responsive to both hypoxia and ionizing radiation (IR). These promoters contain hypoxia regulatory elements (HREs) from the erythropoietin (Epo), the phosphoglycerate kinase1(PGK1) and vascular endothelial growth factor (VEGF) genes, and/or IR-responsive CArG elements from the Early Growth Response 1 (Egr1) gene. The HRE and CArG promoters were able to regulate expression of reporter and suicide genes in human tumor cells, following corresponding stimulation with hypoxia (0.1% O2) or X-irradiation (5Gy) [Greco et al, 2002, Gene Therapy 9:1403]. Furthermore, the chimeric HRE + CArG promoters could be activated by these stimuli independently or even more significantly when given in combination, with the Epo HRE/CArG promoter proving to be the most responsive and robust. In order to amplify and maintain transgene expression even following withdrawal of the triggering stimuli, we have developed a 'molecular switch' system [Scott et al, 2000, Gene Therapy 7:1121]. This 'switch' system has now been engineered as a single vector molecule, containing HRE and CArG promoters. This new series of HRE/CArG switch vectors have been tested in a herpes simplex thymidine kinase (HSVtk)/ganciclovir (GCV) suicide gene assay. Results indicate that a) higher and more selective tumor cell kill is achieved with the switch when compared with the HRE and CArG promoters directly driving HSVtk expression and b) the Epo HRE/CArG switch vectors appear to function as efficiently as the strong constitutive cytomegalovirus (CMV) promoter construct

Adeno-associated viral vectors as agents for gene delivery : application in disorders and trauma of the central nervous system

NARCIS (Netherlands)

Ruitenberg, Marc J; Eggers, Ruben; Boer, Gerard J; Verhaagen, J.

2002-01-01

The use of viral vectors as agents for gene delivery provides a direct approach to manipulate gene expression in the mammalian central nervous system (CNS). The present article describes in detail the methodology for the injection of viral vectors, in particular adeno-associated virus (AAV) vectors,

[Antiapoptotic Effect of the Leukemia Associated Gene MLAA-34 in HeLa Cells].

Science.gov (United States)

Zhang, Peng-Yu; Zhao, Xuan; Zhang, Wen-Juan; Zhang, Wang-Gang; Chen, Yin-Xia

2016-04-01

To study the antiapoptotic effect of leukemia-associated gene MLAA-34 in HeLa cells. The MLAA-34 recombinant lentiviral expression vector was constructed, and the stably transfected HeLa cell line with high expression of MLAA-34 was set up; As(2)O(3) was used to induce apoptosis; the MTT assay, colony formation test and flow cytometry were used to detect the ability of cell proliferation, colong formation, apoptosis and cell cycle changes respectively. After treatment with As(2)O(3), the survival rate of HeLa cells with MLAA-34 overexpression was significantly higher than that of the control cells, and the colony formation ability of MLAA-34 significantly increased, and the high expression of MLAA-34 gene significantly decreased the apoptosis rate of HeLa cells, and decreased the proportion of G(2)/M phase cells. The leukemia-associated gene MLAA-34 has been comfirmed to show antiapoptotic effect in HeLa cells which are induced by As(2)O(3).

Targeted Adenoviral Vector Demonstrates Enhanced Efficacy for In Vivo Gene Therapy of Uterine Leiomyoma.

Science.gov (United States)

Abdelaziz, Mohamed; Sherif, Lotfy; ElKhiary, Mostafa; Nair, Sanjeeta; Shalaby, Shahinaz; Mohamed, Sara; Eziba, Noura; El-Lakany, Mohamed; Curiel, David; Ismail, Nahed; Diamond, Michael P; Al-Hendy, Ayman

2016-04-01

Gene therapy is a potentially effective non-surgical approach for the treatment of uterine leiomyoma. We demonstrated that targeted adenovirus vector, Ad-SSTR-RGD-TK/GCV, was highly effective in selectively inducing apoptosis and inhibiting proliferation of human leiomyoma cells in vitro while sparing normal myometrial cells. An in-vivo study, to compare efficacy and safety of modified adenovirus vector Ad-SSTR-RGD-TK/GCV versus untargeted vector for treatment of leiomyoma. Female nude mice were implanted with rat leiomyoma cells subcutaneously. Then mice were randomized into three groups. Group 1 received Ad-LacZ (marker gene), Group 2 received untargeted Ad-TK, and Group 3 received the targeted Ad-SSTR-RGD-TK. Tumors were measured weekly for 4 weeks. Then mice were sacrificed and tissue samples were collected. Evaluation of markers of apoptosis, proliferation, extracellular matrix, and angiogenesis was performed using Western Blot & Immunohistochemistry. Statistical analysis was done using ANOVA. Dissemination of adenovirus was assessed by PCR. In comparison with the untargeted vector, the targeted adenoviral vector significantly shrank leiomyoma size (P leiomyoma lesions with both targeted and untargeted adenovirus. Targeted adenovirus, effectively reduces tumor size in leiomyoma without dissemination to other organs. Further evaluation of this localized targeted strategy for gene therapy is needed in appropriate preclinical humanoid animal models in preparation for a future pilot human trial. © The Author(s) 2016.

Oviduct-Specific Expression of Human Neutrophil Defensin 4 in Lentivirally Generated Transgenic Chickens

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Liu, Tongxin; Wu, Hanyu; Cao, Dainan; Li, Qingyuan; Zhang, Yaqiong; Li, Ning; Hu, Xiaoxiang

2015-01-01

The expression of oviduct-specific recombinant proteins in transgenic chickens is a promising technology for the production of therapeutic biologics in eggs. In this study, we constructed a lentiviral vector encoding an expression cassette for human neutrophil defensin 4 (HNP4), a compound that displays high activity against Escherichia coli, and produced transgenic chickens that expressed the recombinant HNP4 protein in egg whites. After the antimicrobial activity of the recombinant HNP4 protein was tested at the cellular level, a 2.8-kb ovalbumin promoter was used to drive HNP4 expression specifically in oviduct tissues. From 669 injected eggs, 218 chickens were successfully hatched. Ten G0 roosters, with semens identified as positive for the transgene, were mated with wild-type hens to generate G1 chickens. From 1,274 total offspring, fifteen G1 transgenic chickens were positive for the transgene, which was confirmed by PCR and Southern blotting. The results of the Southern blotting and genome walking indicated that a single copy of the HNP4 gene was integrated into chromosomes 1, 2, 3, 4, 6 and 24 of the chickens. As expected, HNP4 expression was restricted to the oviduct tissues, and the levels of both transcriptional and translational HNP4 expression varied greatly in transgenic chickens with different transgene insertion sites. The amount of HNP4 protein expressed in the eggs of G1 and G2 heterozygous transgenic chickens ranged from 1.65 μg/ml to 10.18 μg/ml. These results indicated that the production of transgenic chickens that expressed HNP4 protein in egg whites was successful. PMID:26020529

Suppression of human breast tumors in NOD/SCID mice by CD44 shRNA gene therapy combined with doxorubicin treatment

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Pham PV

2012-05-01

Full Text Available Phuc Van Pham1, Ngoc Bich Vu1, Thuy Thanh Duong1, Tam Thanh Nguyen1, Nhung Hai Truong1, Nhan Lu Chinh Phan1, Tue Gia Vuong1, Viet Quoc Pham1, Hoang Minh Nguyen1, Kha The Nguyen1, Nhung Thi Nguyen1, Khue Gia Nguyen1, Lam Tan Khat1, Dong Van Le2, Kiet Dinh Truong1, Ngoc Kim Phan11Laboratory of Stem Cell Research and Application, University of Science, Vietnam National University, HCM City, 2Military Medical University, Ha Noi, VietnamBackground: Breast cancer stem cells with a CD44+CD24- phenotype are the origin of breast tumors. Strong CD44 expression in this population indicates its important role in maintaining the stem cell phenotype. Previous studies show that CD44 down-regulation causes CD44+CD24- breast cancer stem cells to differentiate into non-stem cells that are sensitive to antitumor drugs and lose many characteristics of the original cells. In this study, we determined tumor suppression in non-obese severe combined immunodeficiency mice using CD44 shRNA therapy combined with doxorubicin treatment.Methods: Tumor-bearing non-obese severe combined immunodeficiency mice were established by injection of CD44+CD24- cells. To track CD44+CD24- cells, green fluorescence protein was stably transduced using a lentiviral vector prior to injection into mice. The amount of CD44 shRNA lentiviral vector used for transduction was based on CD44 down-regulation by in vitro CD44 shRNA transduction. Mice were treated with direct injection of CD44 shRNA lentiviral vector into tumors followed by doxorubicin administration after 48 hours. The effect was evaluated by changes in the size and weight of tumors compared with that of the control.Results: The combination of CD44 down-regulation and doxorubicin strongly suppressed tumor growth with significant differences in tumor sizes and weights compared with that of CD44 down-regulation or doxorubicin treatment alone. In the combination of CD44 down-regulation and doxorubicin group, the tumor weight was

Transient gene transfer to neurons and glia : analysis of adenoviral vector performance in the CNS and PNS

NARCIS (Netherlands)

Hermens, W.T.J.M.C.; Giger, Roman J; Holtmaat, Anthony J D G; Dijkhuizen, Paul A; Houweling, D A; Verhaagen, J

In this paper a detailed protocol is presented for neuroscientists planning to start work on first generation recombinant adenoviral vectors as gene transfer agents for the nervous system. The performance of a prototype adenoviral vector encoding the bacterial lacZ gene as a reporter was studied,

High Efficiency Gene Correction in Hematopoietic Cells by Donor-Template-Free CRISPR/Cas9 Genome Editing

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Duran Sürün

2018-03-01

Full Text Available The CRISPR/Cas9 prokaryotic adaptive immune system and its swift repurposing for genome editing enables modification of any prespecified genomic sequence with unprecedented accuracy and efficiency, including targeted gene repair. We used the CRISPR/Cas9 system for targeted repair of patient-specific point mutations in the Cytochrome b-245 heavy chain gene (CYBB, whose inactivation causes chronic granulomatous disease (XCGD—a life-threatening immunodeficiency disorder characterized by the inability of neutrophils and macrophages to produce microbicidal reactive oxygen species (ROS. We show that frameshift mutations can be effectively repaired in hematopoietic cells by non-integrating lentiviral vectors carrying RNA-guided Cas9 endonucleases (RGNs. Because about 25% of most inherited blood disorders are caused by frameshift mutations, our results suggest that up to a quarter of all patients suffering from monogenic blood disorders could benefit from gene therapy employing personalized, donor template-free RGNs.

Suppression of leaky expression of adenovirus genes by insertion of microRNA-targeted sequences in the replication-incompetent adenovirus vector genome

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Kahori Shimizu

2014-01-01

Full Text Available Leaky expression of adenovirus (Ad genes occurs following transduction with a conventional replication-incompetent Ad vector, leading to an induction of cellular immunity against Ad proteins and Ad protein-induced toxicity, especially in the late phase following administration. To suppress the leaky expression of Ad genes, we developed novel Ad vectors by incorporating four tandem copies of sequences with perfect complementarity to miR-122a or miR-142-3p into the 3′-untranslated region (UTR of the E2A, E4, or pIX gene, which were mainly expressed from the Ad vector genome after transduction. These Ad vectors easily grew to high titers comparable to those of a conventional Ad vector in conventional 293 cells. The leaky expression of these Ad genes in mouse organs was significantly suppressed by 2- to 100-fold, compared with a conventional Ad vector, by insertion of the miRNA-targeted sequences. Notably, the Ad vector carrying the miR-122a–targeted sequences into the 3′-UTR of the E4 gene expressed higher and longer-term transgene expression and more than 20-fold lower levels of all the Ad early and late genes examined in the liver than a conventional Ad vector. miR-122a–mediated suppression of the E4 gene expression in the liver significantly reduced the hepatotoxicity which an Ad vector causes via both adaptive and non-adaptive immune responses.

Lentiviral-mediated Targeted NF-κB Blockade in Dorsal Spinal Cord Glia Attenuates Sciatic Nerve Injury-induced Neuropathic Pain in the Rat.

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Meunier, Alice; Latrémolière, Alban; Dominguez, Elisa; Mauborgne, Annie; Philippe, Stéphanie; Hamon, Michel; Mallet, Jacques; Benoliel, Jean-Jacques; Pohl, Michel

2007-04-01

Neuropathic pain developing after peripheral nerve injury is associated with altered neuronal and glial cell functions in the spinal cord. Activated glia produces algogenic mediators, exacerbating pain. Among the different intracellular pathways possibly involved in the modified glial function, the nuclear factor κB (NF-κB) system is of particular interest, as numerous genes encoding inflammation- and pain-related molecules are controlled by this transcription factor. NF-κB is a pleiotropic factor also involved in central nervous system homeostasy. To study its role in chronic pain, it is thus essential to inhibit the NF-κB pathway selectively in activated spinal glial cells. Here, we show that when restricted to spinal cord and targeted to glial cells, lentiviral vector-mediated delivery of NF-κB super- repressor IκBα resulted in an inhibition of the NF-κB pathway activated in the rat spinal cord after sciatic nerve injury (chronic constriction injury, CCI). Concomitantly, IκBα overproduction prevented the enhanced expression of interleukin-6 and of inducible nitric oxide synthase associated with chronic constriction injury and resulted in prolonged antihyperalgesic and antiallodynic effects. These data show that targeted blockade of NF-κB activity in spinal glia efficiently alleviates pain behavior in CCI rats, demonstrating the active participation of the glial NF-κB pathway in the development of neuropathic pain after peripheral nerve injury. Copyright © 2007 The American Society of Gene Therapy. Published by Elsevier Inc. All rights reserved.

Genetic modification of adeno-associated viral vector type 2 capsid enhances gene transfer efficiency in polarized human airway epithelial cells.

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White, April F; Mazur, Marina; Sorscher, Eric J; Zinn, Kurt R; Ponnazhagan, Selvarangan

2008-12-01

Cystic fibrosis (CF) is a common genetic disease characterized by defects in the expression of the CF transmembrane conductance regulator (CFTR) gene. Gene therapy offers better hope for the treatment of CF. Adeno-associated viral (AAV) vectors are capable of stable expression with low immunogenicity. Despite their potential in CF gene therapy, gene transfer efficiency by AAV is limited because of pathophysiological barriers in these patients. Although a few AAV serotypes have shown better transduction compared with the AAV2-based vectors, gene transfer efficiency in human airway epithelium has still not reached therapeutic levels. To engineer better AAV vectors for enhanced gene delivery in human airway epithelium, we developed and characterized mutant AAV vectors by genetic capsid modification, modeling the well-characterized AAV2 serotype. We genetically incorporated putative high-affinity peptide ligands to human airway epithelium on the GH loop region of AAV2 capsid protein. Six independent mutant AAV were constructed, containing peptide ligands previously reported to bind with high affinity for known and unknown receptors on human airway epithelial cells. The vectors were tested on nonairway cells and nonpolarized and polarized human airway epithelial cells for enhanced infectivity. One of the mutant vectors, with the peptide sequence THALWHT, not only showed the highest transduction in undifferentiated human airway epithelial cells but also indicated significant transduction in polarized cells. Interestingly, this modified vector was also able to infect cells independently of the heparan sulfate proteoglycan receptor. Incorporation of this ligand on other AAV serotypes, which have shown improved gene transfer efficiency in the human airway epithelium, may enhance the application of AAV vectors in CF gene therapy.

In Vitro Generation of Vascular Wall-Resident Multipotent Stem Cells of Mesenchymal Nature from Murine Induced Pluripotent Stem Cells

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Jennifer Steens

2017-04-01

Full Text Available Summary: The vascular wall (VW serves as a niche for mesenchymal stem cells (MSCs. In general, tissue-specific stem cells differentiate mainly to the tissue type from which they derive, indicating that there is a certain code or priming within the cells as determined by the tissue of origin. Here we report the in vitro generation of VW-typical MSCs from induced pluripotent stem cells (iPSCs, based on a VW-MSC-specific gene code. Using a lentiviral vector expressing the so-called Yamanaka factors, we reprogrammed tail dermal fibroblasts from transgenic mice containing the GFP gene integrated into the Nestin-locus (NEST-iPSCs to facilitate lineage tracing after subsequent MSC differentiation. A lentiviral vector expressing a small set of recently identified human VW-MSC-specific HOX genes then induced MSC differentiation. This direct programming approach successfully mediated the generation of VW-typical MSCs with classical MSC characteristics, both in vitro and in vivo. : In this article, Klein and colleagues show that iPSCs generated from skin fibroblasts of transgenic mice carrying a GFP gene under the control of the endogenous Nestin promoter to facilitate lineage tracing (NEST-iPSCs can be directly programmed toward mouse vascular wall-typical multipotent mesenchymal stem cells (VW-MSC by ectopic lentiviral expression of a previously defined VW-MSC-specific HOX code. Keywords: vascular wall-derived mesenchymal stem cells, HOX gene, induced pluripotent stem cells, direct programming, nestin

Targeted gene therapy and cell reprogramming in Fanconi anemia.

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Rio, Paula; Baños, Rocio; Lombardo, Angelo; Quintana-Bustamante, Oscar; Alvarez, Lara; Garate, Zita; Genovese, Pietro; Almarza, Elena; Valeri, Antonio; Díez, Begoña; Navarro, Susana; Torres, Yaima; Trujillo, Juan P; Murillas, Rodolfo; Segovia, Jose C; Samper, Enrique; Surralles, Jordi; Gregory, Philip D; Holmes, Michael C; Naldini, Luigi; Bueren, Juan A

2014-06-01

Gene targeting is progressively becoming a realistic therapeutic alternative in clinics. It is unknown, however, whether this technology will be suitable for the treatment of DNA repair deficiency syndromes such as Fanconi anemia (FA), with defects in homology-directed DNA repair. In this study, we used zinc finger nucleases and integrase-defective lentiviral vectors to demonstrate for the first time that FANCA can be efficiently and specifically targeted into the AAVS1 safe harbor locus in fibroblasts from FA-A patients. Strikingly, up to 40% of FA fibroblasts showed gene targeting 42 days after gene editing. Given the low number of hematopoietic precursors in the bone marrow of FA patients, gene-edited FA fibroblasts were then reprogrammed and re-differentiated toward the hematopoietic lineage. Analyses of gene-edited FA-iPSCs confirmed the specific integration of FANCA in the AAVS1 locus in all tested clones. Moreover, the hematopoietic differentiation of these iPSCs efficiently generated disease-free hematopoietic progenitors. Taken together, our results demonstrate for the first time the feasibility of correcting the phenotype of a DNA repair deficiency syndrome using gene-targeting and cell reprogramming strategies. © 2014 The Authors. Published under the terms of the CC BY 4.0 license.

Microfluidic Transduction Harnesses Mass Transport Principles to Enhance Gene Transfer Efficiency.

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Tran, Reginald; Myers, David R; Denning, Gabriela; Shields, Jordan E; Lytle, Allison M; Alrowais, Hommood; Qiu, Yongzhi; Sakurai, Yumiko; Li, William C; Brand, Oliver; Le Doux, Joseph M; Spencer, H Trent; Doering, Christopher B; Lam, Wilbur A

2017-10-04

Ex vivo gene therapy using lentiviral vectors (LVs) is a proven approach to treat and potentially cure many hematologic disorders and malignancies but remains stymied by cumbersome, cost-prohibitive, and scale-limited production processes that cannot meet the demands of current clinical protocols for widespread clinical utilization. However, limitations in LV manufacture coupled with inefficient transduction protocols requiring significant excess amounts of vector currently limit widespread implementation. Herein, we describe a microfluidic, mass transport-based approach that overcomes the diffusion limitations of current transduction platforms to enhance LV gene transfer kinetics and efficiency. This novel ex vivo LV transduction platform is flexible in design, easy to use, scalable, and compatible with standard cell transduction reagents and LV preparations. Using hematopoietic cell lines, primary human T cells, primary hematopoietic stem and progenitor cells (HSPCs) of both murine (Sca-1 + ) and human (CD34 + ) origin, microfluidic transduction using clinically processed LVs occurs up to 5-fold faster and requires as little as one-twentieth of LV. As an in vivo validation of the microfluidic-based transduction technology, HSPC gene therapy was performed in hemophilia A mice using limiting amounts of LV. Compared to the standard static well-based transduction protocols, only animals transplanted with microfluidic-transduced cells displayed clotting levels restored to normal. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Enhanced genetic modification of adult growth factor mobilized peripheral blood hematopoietic stem and progenitor cells with rapamycin.

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Li, Lijing; Torres-Coronado, Mónica; Gu, Angel; Rao, Anitha; Gardner, Agnes M; Epps, Elizabeth W; Gonzalez, Nancy; Tran, Chy-Anh; Wu, Xiwei; Wang, Jin-Hui; DiGiusto, David L

2014-10-01

Genetic modification of adult human hematopoietic stem and progenitor cells (HSPCs) with lentiviral vectors leads to long-term gene expression in the progeny of the HSPCs and has been used to successfully treat several monogenic diseases. In some cases, the gene-modified cells have a selective growth advantage over nonmodified cells and eventually are the dominant engrafted population. However, in disease indications for which the gene-modified cells do not have a selective advantage, optimizing transduction of HSPC is paramount to successful stem cell-based gene therapy. We demonstrate here that transduction of adult CD34+ HSPCs with lentiviral vectors in the presence of rapamycin, a widely used mTORC1 inhibitor, results in an approximately threefold increase in stable gene marking with minimal effects on HSPC growth and differentiation. Using this approach, we have demonstrated that we can enhance the frequency of gene-modified HSPCs that give rise to clonogenic progeny in vitro without excessive increases in the number of vector copies per cell or changes in integration pattern. The genetic marking of HSPCs and expression of transgenes is durable, and transplantation of gene-modified HSPCs into immunodeficient mice results in high levels of gene marking of the lymphoid and myeloid progeny in vivo. The prior safe clinical history of rapamycin in other applications supports the use of this compound to generate gene-modified autologous HSPCs for our HIV gene therapy clinical trials. ©AlphaMed Press.

Adenoviral vector-mediated gene transfer and neurotransplantation : possibilities and limitations in grafting of the fetal rat suprachiasmatic nucleus

NARCIS (Netherlands)

van Esseveldt, K E; Liu, R.; Hermens, W.T.J.M.C.; Verhaagen, J; Boer, G J

Several studies have reported on the use of primary neural cells transduced by adenoviral vectors as donor cells in neurotransplantation. In the present investigation, we examined whether adenoviral vector-mediated gene transfer could be used to introduce and express a foreign gene in solid neural

Recombinant vectors construction for cellobiohydrolase encoding gene constitutive expression

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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.

Cloning vector

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Guilfoyle, Richard A.; Smith, Lloyd M.

1994-01-01

A vector comprising a filamentous phage sequence containing a first copy of filamentous phage gene X and other sequences necessary for the phage to propagate is disclosed. The vector also contains a second copy of filamentous phage gene X downstream from a promoter capable of promoting transcription in a bacterial host. In a preferred form of the present invention, the filamentous phage is M13 and the vector additionally includes a restriction endonuclease site located in such a manner as to substantially inactivate the second gene X when a DNA sequence is inserted into the restriction site.

Cloning vector

Science.gov (United States)

Guilfoyle, R.A.; Smith, L.M.

1994-12-27

A vector comprising a filamentous phage sequence containing a first copy of filamentous phage gene X and other sequences necessary for the phage to propagate is disclosed. The vector also contains a second copy of filamentous phage gene X downstream from a promoter capable of promoting transcription in a bacterial host. In a preferred form of the present invention, the filamentous phage is M13 and the vector additionally includes a restriction endonuclease site located in such a manner as to substantially inactivate the second gene X when a DNA sequence is inserted into the restriction site. 2 figures.

Combined application of neutrophin-3 gene and neural stem cells is ameliorative to delay of denervated skeletal muscular atrophy after tibial nerve transection in rats.

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Lin, Sen; Xu, Jianguang; Hu, Shaonan; Xu, Lei; Zhang, Changqing; Wang, Yang; Gu, Yudong

2011-01-01

Examination of the therapeutic efficacy of neural stem cells (NSCs) has recently become the focus of much investigation. In this study we present an insight of the effects of combined application with neurotrophin-3 (NT-3) and NSCs that derived from rat embryo spinal cord on delaying denervated skeletal muscular atrophy after tibial nerve was severed. NT-3 gene was amplified by PCR and subcloned into lentiviral vector pWPXL-MOD to construct a lentiviral expression vector pWPXL-MOD-NT-3. A positive clone expressing NT-3 (named NSCs-NT-3) was obtained and used for differentiation in vitro and transplantation. Sixty adult rats, whose tibial nerves were sectioned, were divided into two groups: one grafted with NSCs-NT-3 (experimental group, n = 30) and the other with NSCs transfected by pWPXL-MOD (control group, n = 30). The cell survival and differentiation, NT-3 gene expression, and effect of delaying denervated skeletal muscular atrophy were examined through immunohistostaining, RT-PCR, Western blot, electrophysiological analysis, and mean cross-sectional area (CSA) of gastrocnemius, respectively. The results show that the NT-3 gene, which is comprised of 777 bp, was cloned and significantly different expression were detected between NSCs and NSCs-NT-3 in vitro. Quantitative analysis of the choline acetyltransferase (ChAT) immunopositive cells revealed a significant increase in experimental group compared to the control group 4 weeks after implantation (p ChAT immunopositive cells were detected near the engrafted region only in experimental group. Furthermore, the effect in delaying denervated skeletal muscular atrophy is indicated in the EMG examination and mean CSA of gastrocnemius. These findings suggest that the neural stem cells expressing NT-3 endogenously would be a better graft candidate for the delay of denervated skeletal muscular atrophy.

MR molecular imaging of tumours using ferritin heavy chain reporter gene expression mediated by the hTERT promoter

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Yang, Yan [Third Military Medical University, Department of Radiology, XinQiao Hospital, ChongQing (China); The First Affiliated Hospital of ChengDu Medical College, Department of Radiology, ChengDu (China); Gong, Ming-fu; Yang, Hua; Zhang, Song; Wang, Guang-xian; Su, Tong-sheng; Wen, Li; Zhang, Dong [Third Military Medical University, Department of Radiology, XinQiao Hospital, ChongQing (China)

2016-11-15

Using the human telomerase reverse transcriptase (hTERT) promoter and the modified ferritin heavy chain (Fth) reporter gene, reporter gene expression for MRI was examined in telomerase positive and negative tumour cells and xenografts. Activity of the reporter gene expression vector Lenti-hTERT-Fth1-3FLAG-Puro was compared to constitutive CMV-driven expression and to the untransfected parental control in five tumour cell lines: A549, SKOV3, 293T, U2OS and HPDLF. In vitro, transfected cells were evaluated for FLAG-tagged protein expression, iron accumulation and transverse relaxation. In vivo, tumours transduced by lentiviral vector injection were imaged using T2*WI. Changes in tumour signal intensity were validated by histology. Only telomerase positive tumour cells expressed FLAG-tagged Fth and displayed an increase in R2* above the parental control, with a corresponding change in T2*WI. In addition, only telomerase positive tumours, transduced by injection of the reporter gene expression construct, exhibited a change in signal intensity on T2*WI. Tumour histology verified the expression of FLAG-tagged Fth and iron accumulation in telomerase positive tissue. Reporter gene expression for MRI, using the Fth reporter and the hTERT promoter, may be a useful strategy for the non-invasive diagnosis of many types of cancer. (orig.)

A novel and efficient gene transfer strategy reduces glial reactivity and improves neuronal survival and axonal growth in vitro.

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Mathieu Desclaux

Full Text Available BACKGROUND: The lack of axonal regeneration in the central nervous system is attributed among other factors to the formation of a glial scar. This cellular structure is mainly composed of reactive astrocytes that overexpress two intermediate filament proteins, the glial fibrillary acidic protein (GFAP and vimentin. Indeed, in vitro, astrocytes lacking GFAP or both GFAP and vimentin were shown to be the substrate for increased neuronal plasticity. Moreover, double knockout mice lacking both GFAP and vimentin presented lower levels of glial reactivity in vivo, significant axonal regrowth and improved functional recovery in comparison with wild-type mice after spinal cord hemisection. From these results, our objective was to develop a novel therapeutic strategy for axonal regeneration, based on the targeted suppression of astroglial reactivity and scarring by lentiviral-mediated RNA-interference (RNAi. METHODS AND FINDINGS: In this study, we constructed two lentiviral vectors, Lv-shGFAP and Lv-shVIM, which allow efficient and stable RNAi-mediated silencing of endogenous GFAP or vimentin in vitro. In cultured cortical and spinal reactive astrocytes, the use of these vectors resulted in a specific, stable and highly significant decrease in the corresponding protein levels. In a second model -- scratched primary cultured astrocytes -- Lv-shGFAP, alone or associated with Lv-shVIM, decreased astrocytic reactivity and glial scarring. Finally, in a heterotopic coculture model, cortical neurons displayed higher survival rates and increased neurite growth when cultured with astrocytes in which GFAP and vimentin had been invalidated by lentiviral-mediated RNAi. CONCLUSIONS: Lentiviral-mediated knockdown of GFAP and vimentin in astrocytes show that GFAP is a key target for modulating reactive gliosis and monitoring neuron/glia interactions. Thus, manipulation of reactive astrocytes with the Lv-shGFAP vector constitutes a promising therapeutic strategy for

A novel and efficient gene transfer strategy reduces glial reactivity and improves neuronal survival and axonal growth in vitro.

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Desclaux, Mathieu; Teigell, Marisa; Amar, Lahouari; Vogel, Roland; Gimenez Y Ribotta, Minerva; Privat, Alain; Mallet, Jacques

2009-07-14

The lack of axonal regeneration in the central nervous system is attributed among other factors to the formation of a glial scar. This cellular structure is mainly composed of reactive astrocytes that overexpress two intermediate filament proteins, the glial fibrillary acidic protein (GFAP) and vimentin. Indeed, in vitro, astrocytes lacking GFAP or both GFAP and vimentin were shown to be the substrate for increased neuronal plasticity. Moreover, double knockout mice lacking both GFAP and vimentin presented lower levels of glial reactivity in vivo, significant axonal regrowth and improved functional recovery in comparison with wild-type mice after spinal cord hemisection. From these results, our objective was to develop a novel therapeutic strategy for axonal regeneration, based on the targeted suppression of astroglial reactivity and scarring by lentiviral-mediated RNA-interference (RNAi). In this study, we constructed two lentiviral vectors, Lv-shGFAP and Lv-shVIM, which allow efficient and stable RNAi-mediated silencing of endogenous GFAP or vimentin in vitro. In cultured cortical and spinal reactive astrocytes, the use of these vectors resulted in a specific, stable and highly significant decrease in the corresponding protein levels. In a second model -- scratched primary cultured astrocytes -- Lv-shGFAP, alone or associated with Lv-shVIM, decreased astrocytic reactivity and glial scarring. Finally, in a heterotopic coculture model, cortical neurons displayed higher survival rates and increased neurite growth when cultured with astrocytes in which GFAP and vimentin had been invalidated by lentiviral-mediated RNAi. Lentiviral-mediated knockdown of GFAP and vimentin in astrocytes show that GFAP is a key target for modulating reactive gliosis and monitoring neuron/glia interactions. Thus, manipulation of reactive astrocytes with the Lv-shGFAP vector constitutes a promising therapeutic strategy for increasing glial permissiveness and permitting axonal regeneration

Efficient adenoviral vector directed expression of a foreign gene to neurons and sustentacular cells in the mouse olfactory neuroepithelium

NARCIS (Netherlands)

Gispen, W.H.; Holtmaat, A.J.G.D.; Hermens, W.T.J.M.C.; Oestreicher, A.B.; Kaplitt, M.G.; Verhaagen, J.

1996-01-01

Replication deficient recombinant adenoviral vectors are efficient gene transfer agents for postmitotic cells, including neurons and glial cells. In this paper we have examined the effectiveness of adenoviral vector-mediated gene transfer to the olfactory epithelium of adult mice. We show that

Efficient adenoviral vector-directed expression of a foreign gene to neurons and sustentacular cells in the mouse olfactory neuroepithelium

NARCIS (Netherlands)

Holtmaat, Anthony J D G; Hermens, W.T.J.M.C.; Oestreicher, A B; Gispen, Willem Hendrik; Kaplitt, M G; Verhaagen, J

1996-01-01

Replication deficient recombinant adenoviral vectors are efficient gene transfer agents for postmitotic cells, including neurons and glial cells. In this paper we have examined the effectiveness of adenoviral vector-mediated gene transfer to the olfactory epithelium of adult mice. We show that

Highly efficient transduction of human plasmacytoid dendritic cells without phenotypic and functional maturation

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Plumas Joel

2009-01-01

Full Text Available Abstract Background Gene modified dendritic cells (DC are able to modulate DC functions and induce therapeutic immunity or tolerance in an antigen-specific manner. Among the different DC subsets, plasmacytoid DC (pDC are well known for their ability to recognize and respond to a variety of viruses by secreting high levels of type I interferon. Methods We analyzed here, the transduction efficiency of a pDC cell line, GEN2.2, and of pDC derived from CD34+ progenitors, using lentiviral vectors (LV pseudotyped with different envelope glycoproteins such as the vesicular stomatitis virus envelope (VSVG, the gibbon ape leukaemia virus envelope (GaLV or the feline endogenous virus envelope (RD114. At the same time, we evaluated transgene expression (E-GFP reporter gene under the control of different promoters. Results We found that efficient gene transfer into pDC can be achieved with VSVG-pseudotyped lentiviral vectors (LV under the control of phoshoglycerate kinase (PGK and elongation factor-1 (EF1α promoters (28% to 90% of E-GFP+ cells, respectively in the absence of phenotypic and functional maturation. Surprisingly, promoters (desmin or synthetic C5–12 described as muscle-specific and which drive gene expression in single strand AAV vectors in gene therapy protocols were very highly active in pDC using VSVG-LV. Conclusion Taken together, our results indicate that LV vectors can serve to design pDC-based vaccines in humans, and they are also useful in vitro to evaluate the immunogenicity of the vector preparations, and the specificity and safety of given promoters used in gene therapy protocols.

Efficient Gene Delivery to Pig Airway Epithelia and Submucosal Glands Using Helper-Dependent Adenoviral Vectors

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Huibi Cao

2013-01-01

Full Text Available Airway gene delivery is a promising strategy to treat patients with life-threatening lung diseases such as cystic fibrosis (CF. However, this strategy has to be evaluated in large animal preclinical studies in order to translate it to human applications. Because of anatomic and physiological similarities between the human and pig lungs, we utilized pig as a large animal model to examine the safety and efficiency of airway gene delivery with helper-dependent adenoviral vectors. Helper-dependent vectors carrying human CFTR or reporter gene LacZ were aerosolized intratracheally into pigs under bronchoscopic guidance. We found that the LacZ reporter and hCFTR transgene products were efficiently expressed in lung airway epithelial cells. The transgene vectors with this delivery can also reach to submucosal glands. Moreover, the hCFTR transgene protein localized to the apical membrane of both ciliated and nonciliated epithelial cells, mirroring the location of wild-type CF transmembrane conductance regulator (CFTR. Aerosol delivery procedure was well tolerated by pigs without showing systemic toxicity based on the limited number of pigs tested. These results provide important insights into developing clinical strategies for human CF lung gene therapy.

[Construction and Function Verification of a Novel Shuttle Vector Containing a Marker Gene Self-deletion System].

Science.gov (United States)

Li, Lili; Wang, Zhan; Zhou, Yubai; Zhang, Fang; Shen, Sisi; Li, Zelin; Zeng, Yi

2015-09-01

For rapid and accurate screening of recombinant modified vaccinia virus Ankara (rMVA) that satisfied the quality standards of clinical trials, a novel shuttle vector that can delete the marker gene automatically during virus propagation was construted: pZL-EGFP. To construct the pZL-EGFP, the original shuttle vector pSC11 was modified by replacing the LacZ marker gene with enhanced green fluorescent protein (EGFP) and then inserting homologous sequences of TKL into the flank regions of EGFP. Baby hamster kidney (BHK)-21 cells were cotransfected with pZL-EGFP and MVA, and underwent ten passages and one plaque screening to obtain the EGFP-free rMVA carrying the exogenous gene. Resulting rMVA was tested by polymerase chain reaction and western blotting to verify pZL-EGFP function. A novel shuttle vector pZL-EGFP containing an EGFP marker gene which could be deleted automatically was constructed. This gene deletion had no effect on the activities of rMVA, and the exogenous gene could be expressed stably. These results suggest that rMVA can be packaged efficiently by homologous recombination between pZL-EGFP and MVA in BHK-21 cells, and that the carried EGFP gene can be removed automatically by intramolecular homologous recombination during virus passage. Meanwhile, the gene deletion had no influence on the activities of rMVA and the expression of exogenous target gene. This study lays a solid foundation for the future research.

Design and application of cationic amphiphilic β-cyclodextrin derivatives as gene delivery vectors

Science.gov (United States)

Wan, Ning; Huan, Meng-Lei; Ma, Xi-Xi; Jing, Zi-Wei; Zhang, Ya-Xuan; Li, Chen; Zhou, Si-Yuan; Zhang, Bang-Le

2017-11-01

The nano self-assembly profiles of amphiphilic gene delivery vectors could improve the density of local cationic head groups to promote their DNA condensation capability and enhance the interaction between cell membrane and hydrophobic tails, thus increasing cellular uptake and gene transfection. In this paper, two series of cationic amphiphilic β-cyclodextrin (β-CD) derivatives were designed and synthesized by using 6-mono-OTs-β-CD (1) as the precursor to construct amphiphilic gene vectors with different building blocks in a selective and controlled manner. The effect of different type and degree of cationic head groups on transfection and the endocytic mechanism of β-CD derivatives/DNA nanocomplexes were also investigated. The results demonstrated that the designed β-cyclodextrin derivatives were able to compact DNA to form stable nanocomplexes and exhibited low cytotoxicity. Among them, PEI-1 with PEI head group showed enhanced transfection activity, significantly higher than commercially available agent PEI25000 especially in the presence of serum, showing potential application prospects in clinical trials. Moreover, the endocytic uptake mechanism involved in the gene transfection of PEI-1 was mainly through caveolae-mediated endocytosis, which could avoid the lysosomal degradation of loaded gene, and had great importance for improving gene transfection activity.

Gene transfer in rodents and primates as a new tool for modeling diseases in animals and assessing functions by in vivo imaging

Energy Technology Data Exchange (ETDEWEB)

Deglon, N. [Atomic Energy Commission (CEA), Dept. of Medical Research and MIRCen Program, 91 - Orsay (France)

2006-07-01

The identification of disease-causing genes in familial forms of neuro-degenerative disorders and the development of genetic models closely replicating human CNS pathologies have drastically changed our understanding of the molecular events leading to neuronal cell death. If these achievements open new opportunities of therapeutic interventions efficient delivery systems taking into account the specificity of the central nervous system are required to administer therapeutic candidates. In addition, there is a need to develop 1) genetic models in large animals that replicate late stages of the diseases and 2) imaging techniques suitable for longitudinal, quantitative and non-invasive evaluation of disease progression and the evaluation of new therapeutic strategies. Over the last few years, we have investigated the potential of lentiviral vectors as tool to model and treat CNS disorders. The use of lentiviral vectors to create animal model of these pathologies holds various advantages compared to classical transgenic approaches. Viral vectors are versatile, highly flexible tools to perform in vivo studies. Multiple genetic models can be created in a short period of time. High transduction efficiencies as well as robust and sustained trans-gene expression lead to the rapid appearance of functional and behavioral abnormalities and severe neuro-degeneration. Targeted injections in different brain areas can be used to investigate the regional specificity of the neuro-pathology and eliminate potential side effects associated with a widespread over-expression of the trans-gene. Finally, models can be established in different mammalian species including non-human primates, thereby providing an opportunity to assess complex behavioral changes and perform longitudinal follow-up of neuro-pathological alterations by imaging. We have demonstrated the proof of principle of this approach for Huntington's disease. We have shown that the intratriatal injection of lentiviral

Gene transfer in rodents and primates as a new tool for modeling diseases in animals and assessing functions by in vivo imaging

International Nuclear Information System (INIS)

Deglon, N.

2006-01-01

The identification of disease-causing genes in familial forms of neuro-degenerative disorders and the development of genetic models closely replicating human CNS pathologies have drastically changed our understanding of the molecular events leading to neuronal cell death. If these achievements open new opportunities of therapeutic interventions efficient delivery systems taking into account the specificity of the central nervous system are required to administer therapeutic candidates. In addition, there is a need to develop 1) genetic models in large animals that replicate late stages of the diseases and 2) imaging techniques suitable for longitudinal, quantitative and non-invasive evaluation of disease progression and the evaluation of new therapeutic strategies. Over the last few years, we have investigated the potential of lentiviral vectors as tool to model and treat CNS disorders. The use of lentiviral vectors to create animal model of these pathologies holds various advantages compared to classical transgenic approaches. Viral vectors are versatile, highly flexible tools to perform in vivo studies. Multiple genetic models can be created in a short period of time. High transduction efficiencies as well as robust and sustained trans-gene expression lead to the rapid appearance of functional and behavioral abnormalities and severe neuro-degeneration. Targeted injections in different brain areas can be used to investigate the regional specificity of the neuro-pathology and eliminate potential side effects associated with a widespread over-expression of the trans-gene. Finally, models can be established in different mammalian species including non-human primates, thereby providing an opportunity to assess complex behavioral changes and perform longitudinal follow-up of neuro-pathological alterations by imaging. We have demonstrated the proof of principle of this approach for Huntington's disease. We have shown that the intratriatal injection of lentiviral vector

Construction of a recombinant viral vector containing part of the nucleocapsid protein gene of newcastle disease virus

Energy Technology Data Exchange (ETDEWEB)

Bader, D.E.

1995-09-01

This report describes the procedures used to clone a 673 base pair gene fragment of the major nucleocapsid protein gene of Newcastle disease virus into a viral vector molecule for the purpose of maintaining a stable, long-term, renewable source of this target sequence for gene probe studies. The gene fragment was prepared by reverse-transcription polymerase chain reaction of Newcastle disease virus RNA and was cloned into the viral DNA vector Ml3mp18 RF to produce a recombinant DNA molecule. The cloned fragment was shown to be present in the recombinant clones based on (i) clonal selection on indicator plates; (ii) restriction enzyme analysis; (iii) gene probe analysis and (iv) nested PCR amplification.

In Vitro Generation of Vascular Wall-Resident Multipotent Stem Cells of Mesenchymal Nature from Murine Induced Pluripotent Stem Cells.

Science.gov (United States)

Steens, Jennifer; Zuk, Melanie; Benchellal, Mohamed; Bornemann, Lea; Teichweyde, Nadine; Hess, Julia; Unger, Kristian; Görgens, André; Klump, Hannes; Klein, Diana

2017-04-11

The vascular wall (VW) serves as a niche for mesenchymal stem cells (MSCs). In general, tissue-specific stem cells differentiate mainly to the tissue type from which they derive, indicating that there is a certain code or priming within the cells as determined by the tissue of origin. Here we report the in vitro generation of VW-typical MSCs from induced pluripotent stem cells (iPSCs), based on a VW-MSC-specific gene code. Using a lentiviral vector expressing the so-called Yamanaka factors, we reprogrammed tail dermal fibroblasts from transgenic mice containing the GFP gene integrated into the Nestin-locus (NEST-iPSCs) to facilitate lineage tracing after subsequent MSC differentiation. A lentiviral vector expressing a small set of recently identified human VW-MSC-specific HOX genes then induced MSC differentiation. This direct programming approach successfully mediated the generation of VW-typical MSCs with classical MSC characteristics, both in vitro and in vivo. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Correction of mutant Fanconi anemia gene by homologous recombination in human hematopoietic cells using adeno-associated virus vector.

Science.gov (United States)

Paiboonsukwong, Kittiphong; Ohbayashi, Fumi; Shiiba, Haruka; Aizawa, Emi; Yamashita, Takayuki; Mitani, Kohnosuke

2009-11-01

Adeno-associated virus (AAV) vectors have been shown to correct a variety of mutations in human cells by homologous recombination (HR) at high rates, which can overcome insertional mutagenesis and transgene silencing, two of the major hurdles in conventional gene addition therapy of inherited diseases. We examined an ability of AAV vectors to repair a mutation in human hematopoietic cells by HR. We infected a human B-lymphoblastoid cell line (BCL) derived from a normal subject with an AAV, which disrupts the hypoxanthine phosphoribosyl transferase1 (HPRT1) locus, to measure the frequency of AAV-mediated HR in BCL cells. We subsequently constructed an AAV vector encoding the normal sequences from the Fanconi anemia group A (FANCA) locus to correct a mutation in the gene in BCL derived from a FANCA patient. Under optimal conditions, approximately 50% of BCL cells were transduced with an AAV serotype 2 (AAV-2) vector. In FANCA BCL cells, up to 0.016% of infected cells were gene-corrected by HR. AAV-mediated restoration of normal genotypic and phenotypic characteristics in FANCA-mutant cells was confirmed at the DNA, protein and functional levels. The results obtained in the present study indicate that AAV vectors may be applicable for gene correction therapy of inherited hematopoietic disorders.

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

Efficient gene delivery to primary human retinal pigment epithelial cells: The innate and acquired properties of vectors.

Science.gov (United States)

Tasharrofi, Nooshin; Kouhkan, Fatemeh; Soleimani, Masoud; Soheili, Zahra-Soheila; Atyabi, Fatemeh; Akbari Javar, Hamid; Abedin Dorkoosh, Farid

2017-02-25

The purpose of this study is designing non-viral gene delivery vectors for transfection of the primary human retinal pigment epithelial cells (RPE). In the design process of gene delivery vectors, considering physicochemical properties of vectors alone does not seem to be enough since they interact with constituents of the surrounding environment and hence gain new characteristics. Moreover, due to these interactions, their cargo can be released untimely or undergo degradation before reaching to the target cells. Further, the characteristics of cells itself can also influence the transfection efficacy. For example, the non-dividing property of RPE cells can impede the transfection efficiency which in most studies was ignored by using immortal cell lines. In this study, vectors with different characteristics differing in mixing orders of pDNA, PEI polymer, and PLGA/PEI or PLGA nanoparticles were prepared and characterized. Then, their characteristics and efficacy in gene delivery to RPE cells in the presence of vitreous or fetal bovine serum (FBS) were evaluated. All formulations showed no cytotoxicity and were able to protect pDNA from premature release and degradation in extracellular media. Also, the adsorption of vitreous or serum proteins onto the surface of vectors changed their properties and hence cellular uptake and transfection efficacy. Copyright © 2016 Elsevier B.V. All rights reserved.

MicroRNA-143 Downregulates Interleukin-13 Receptor Alpha1 in Human Mast Cells

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Jianqiu Cheng

2013-08-01

Full Text Available MicroRNA-143 (miR-143 was found to be downregulated in allergic rhinitis, and bioinformatics analysis predicted that IL-13Rα1 was a target gene of miR-143. To understand the molecular mechanisms of miR-143 involved in the pathogenesis of allergic inflammation, recombinant miR-143 plasmid vectors were constructed, and human mast cell-1(HMC-1 cells which play a central role in the allergic response were used for study. The plasmids were transfected into HMC-1 cells using a lentiviral vector. Expression of IL-13Rα1 mRNA was then detected by reverse transcriptase polymerase chain reaction (RT-PCR and Western Blotting. The miR-143 lentiviral vector was successfully stably transfected in HMC-1 cells for target gene expression. Compared to the control, the target gene IL-13Rα1 was less expressed in HMC-1 transfected with miR-143 as determined by RT-PCR and Western Blotting (p < 0.05; this difference in expression was statistically significant and the inhibition efficiency was 71%. It indicates that miR-143 directly targets IL-13Rα1 and suppresses IL-13Rα1 expression in HMC-1 cells. Therefore, miR-143 may be associated with allergic reaction in human mast cells.

Recombinant human parvovirus B19 vectors: erythroid cell-specific delivery and expression of transduced genes.

Science.gov (United States)

Ponnazhagan, S; Weigel, K A; Raikwar, S P; Mukherjee, P; Yoder, M C; Srivastava, A

1998-06-01

A novel packaging strategy combining the salient features of two human parvoviruses, namely the pathogenic parvovirus B19 and the nonpathogenic adeno-associated virus type 2 (AAV), was developed to achieve erythroid cell-specific delivery as well as expression of the transduced gene. The development of such a chimeric vector system was accomplished by packaging heterologous DNA sequences cloned within the inverted terminal repeats of AAV and subsequently packaging the DNA inside the capsid structure of B19 virus. Recombinant B19 virus particles were assembled, as evidenced by electron microscopy as well as DNA slot blot analyses. The hybrid vector failed to transduce nonerythroid human cells, such as 293 cells, as expected. However, MB-02 cells, a human megakaryocytic leukemia cell line which can be infected by B19 virus following erythroid differentiation with erythropoietin (N. C. Munshi, S. Z. Zhou, M. J. Woody, D. A. Morgan, and A. Srivastava, J. Virol. 67:562-566, 1993) but lacks the putative receptor for AAV (S. Ponnazhagan, X.-S. Wang, M. J. Woody, F. Luo, L. Y. Kang, M. L. Nallari, N. C. Munshi, S. Z. Zhou, and A. Srivastava, J. Gen. Virol. 77:1111-1122, 1996), were readily transduced by this vector. The hybrid vector was also found to specifically target the erythroid population in primary human bone marrow cells as well as more immature hematopoietic progenitor cells following erythroid differentiation, as evidenced by selective expression of the transduced gene in these target cells. Preincubation with anticapsid antibodies against B19 virus, but not anticapsid antibodies against AAV, inhibited transduction of primary human erythroid cells. The efficiency of transduction of primary human erythroid cells by the recombinant B19 virus vector was significantly higher than that by the recombinant AAV vector. Further development of the AAV-B19 virus hybrid vector system should prove beneficial in gene therapy protocols aimed at the correction of inherited and

Recombinant Human Parvovirus B19 Vectors: Erythroid Cell-Specific Delivery and Expression of Transduced Genes

Science.gov (United States)

Ponnazhagan, Selvarangan; Weigel, Kirsten A.; Raikwar, Sudhanshu P.; Mukherjee, Pinku; Yoder, Mervin C.; Srivastava, Arun

1998-01-01

A novel packaging strategy combining the salient features of two human parvoviruses, namely the pathogenic parvovirus B19 and the nonpathogenic adeno-associated virus type 2 (AAV), was developed to achieve erythroid cell-specific delivery as well as expression of the transduced gene. The development of such a chimeric vector system was accomplished by packaging heterologous DNA sequences cloned within the inverted terminal repeats of AAV and subsequently packaging the DNA inside the capsid structure of B19 virus. Recombinant B19 virus particles were assembled, as evidenced by electron microscopy as well as DNA slot blot analyses. The hybrid vector failed to transduce nonerythroid human cells, such as 293 cells, as expected. However, MB-02 cells, a human megakaryocytic leukemia cell line which can be infected by B19 virus following erythroid differentiation with erythropoietin (N. C. Munshi, S. Z. Zhou, M. J. Woody, D. A. Morgan, and A. Srivastava, J. Virol. 67:562–566, 1993) but lacks the putative receptor for AAV (S. Ponnazhagan, X.-S. Wang, M. J. Woody, F. Luo, L. Y. Kang, M. L. Nallari, N. C. Munshi, S. Z. Zhou, and A. Srivastava, J. Gen. Virol. 77:1111–1122, 1996), were readily transduced by this vector. The hybrid vector was also found to specifically target the erythroid population in primary human bone marrow cells as well as more immature hematopoietic progenitor cells following erythroid differentiation, as evidenced by selective expression of the transduced gene in these target cells. Preincubation with anticapsid antibodies against B19 virus, but not anticapsid antibodies against AAV, inhibited transduction of primary human erythroid cells. The efficiency of transduction of primary human erythroid cells by the recombinant B19 virus vector was significantly higher than that by the recombinant AAV vector. Further development of the AAV-B19 virus hybrid vector system should prove beneficial in gene therapy protocols aimed at the correction of inherited

Novel redox nanomedicine improves gene expression of polyion complex vector

Directory of Open Access Journals (Sweden)

Kazuko Toh, Toru Yoshitomi, Yutaka Ikeda and Yukio Nagasaki

2011-01-01

Full Text Available Gene therapy has generated worldwide attention as a new medical technology. While non-viral gene vectors are promising candidates as gene carriers, they have several issues such as toxicity and low transfection efficiency. We have hypothesized that the generation of reactive oxygen species (ROS affects gene expression in polyplex supported gene delivery systems. The effect of ROS on the gene expression of polyplex was evaluated using a nitroxide radical-containing nanoparticle (RNP as an ROS scavenger. When polyethyleneimine (PEI/pGL3 or PEI alone was added to the HeLa cells, ROS levels increased significantly. In contrast, when (PEI/pGL3 or PEI was added with RNP, the ROS levels were suppressed. The luciferase expression was increased by the treatment with RNP in a dose-dependent manner and the cellular uptake of pDNA was also increased. Inflammatory cytokines play an important role in ROS generation in vivo. In particular, tumor necrosis factor (TNF-α caused intracellular ROS generation in HeLa cells and decreased gene expression. RNP treatment suppressed ROS production even in the presence of TNF-α and increased gene expression. This anti-inflammatory property of RNP suggests that it may be used as an effective adjuvant for non-viral gene delivery systems.

Development of new USER-based cloning vectors for multiple genes expression in Saccharomyces cerevisiae

DEFF Research Database (Denmark)

Kildegaard, Kanchana Rueksomtawin; Jensen, Niels Bjerg; Maury, Jerome

2013-01-01

auxotrophic and dominant markers for convenience of use. Our vector set also contains both integrating and multicopy vectors for stability of protein expression and high expression level. We will make the new vector system available to the yeast community and provide a comprehensive protocol for cloning...... the production strain with the proper phenotype and product yield. However, the sequential number of metabolic engineering is time-consuming. Furthermore, the number of available selectable markers is also limiting the number of genetic modifications. To overcome these limitations, we have developed a new set...... of shuttle vectors for convenience of use for high-throughput cloning and selectable marker recycling. The new USER-based cloning vectors consist of a unique USER site and a CRE-loxP-mediated marker recycling system. The USER site allows insertion of genes of interest along with a bidirectional promoter...

Hypoxia-inducible bidirectional shRNA expression vector delivery using PEI/chitosan-TBA copolymers for colorectal Cancer gene therapy.

Science.gov (United States)

Javan, Bita; Atyabi, Fatemeh; Shahbazi, Majid

2018-04-12

This investigation was conducted to construct a hypoxia/colorectal dual-specific bidirectional short hairpin RNA (shRNA) expression vector and to transfect it into the colon cancer cell line HT-29 with PEI/chitosan-TBA nanoparticles for the simultaneous knock down of β-catenin and Bcl-2 under hypoxia. To construct a pRNA-bipHRE-CEA vector, the carcinoma embryonic antigen (CEA) promoter designed in two directions and the vascular endothelial growth factor (VEGF) enhancer were inserted between two promoters for hypoxic cancer specific gene expression. To confirm the therapeutic effect of the dual-specific vector, β-catenin and Bcl-2 shRNAs were inserted downstream of each promoter. The physicochemical properties, the cytotoxicity, and the transfection efficiency of these PEI/chitosan-TBA nanoparticles were investigated. In addition, the antitumor effects of the designed vector on the expression of β-catenin and Bcl-2, cell cycle distribution, and apoptosis were investigated in vitro. The silencing effect of the hypoxia-response shRNA expression vector was relatively low (18%-25%) under normoxia, whereas it was significantly increased to approximately 50%-60% in the HT-29 cell line. Moreover, the cancer cells showed significant G0/G1 arrest and increased apoptosis due to gene silencing under hypoxia. Furthermore, MTS assay, fluorescence microscopy images, and flow cytometry analyses confirmed that the PEI/chitosan-TBA blend system provided effective transfection with low cytotoxicity. This novel hypoxia-responsive shRNA expression vector may be useful for RNA interference (RNAi)-based cancer gene therapy in hypoxic colorectal tumors. Moreover, the PEI/chitosan-TBA copolymer might be a promising gene carrier for use in gene transfer in vivo. Copyright © 2017. Published by Elsevier Inc.

Episomal Nonviral Gene Therapy Vectors Slow Progression of Atherosclerosis in a Model of Familial Hypercholesterolemia

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Alastair G Kerr

2016-01-01

Full Text Available Familial hypercholesterolemia (FH is a life-threatening genetic disorder characterized by elevated levels of plasma low-density lipoprotein cholesterol (LDL-cholesterol. Current attempts at gene therapy for FH have been limited by the use of strong heterologous promoters which lack genomic DNA elements essential for regulated expression. Here, we have combined a minigene vector expressing the human LDLR cDNA from a 10 kb native human LDLR locus genomic DNA promoter element, with an efficient miRNA targeting 3-hydroxy-3-methylgutaryl-coenzyme A reductase (Hmgcr, to further enhance LDLR expression. We show that the combined vector suppresses endogenous Hmgcr transcripts in vivo, leading to an increase in LDLR transgene expression. In a diet-induced Ldlr-/- mouse model of FH, we show that administration of the combined vector reduces atherogenic plasma lipids by ≃32%. Finally, we demonstrate that our episomal nonviral vectors are able to reduce atherosclerosis by ≃40% after 12 weeks in vivo. Taken together, the vector system we describe exploits the normal cellular regulation of the LDLR to provide prolonged expression of LDLR through targeted knockdown of Hmgcr. This novel gene therapy system could act alone, or in synergy with current therapies that modulate intracellular cholesterol, such as statins, greatly enhancing its therapeutic application for FH.

Lentiviral-mediated targeted NF-kappaB blockade in dorsal spinal cord glia attenuates sciatic nerve injury-induced neuropathic pain in the rat.

Science.gov (United States)

Meunier, Alice; Latrémolière, Alban; Dominguez, Elisa; Mauborgne, Annie; Philippe, Stéphanie; Hamon, Michel; Mallet, Jacques; Benoliel, Jean-Jacques; Pohl, Michel

2007-04-01

Neuropathic pain developing after peripheral nerve injury is associated with altered neuronal and glial cell functions in the spinal cord. Activated glia produces algogenic mediators, exacerbating pain. Among the different intracellular pathways possibly involved in the modified glial function, the nuclear factor kappaB (NF-kappaB) system is of particular interest, as numerous genes encoding inflammation- and pain-related molecules are controlled by this transcription factor. NF-kappaB is a pleiotropic factor also involved in central nervous system homeostasy. To study its role in chronic pain, it is thus essential to inhibit the NF-kappaB pathway selectively in activated spinal glial cells. Here, we show that when restricted to spinal cord and targeted to glial cells, lentiviral vector-mediated delivery of NF-kappaB super- repressor IkappaBalpha resulted in an inhibition of the NF-kappaB pathway activated in the rat spinal cord after sciatic nerve injury (chronic constriction injury, CCI). Concomitantly, IkappaBalpha overproduction prevented the enhanced expression of interleukin-6 and of inducible nitric oxide synthase associated with chronic constriction injury and resulted in prolonged antihyperalgesic and antiallodynic effects. These data show that targeted blockade of NF-kappaB activity in spinal glia efficiently alleviates pain behavior in CCI rats, demonstrating the active participation of the glial NF-kappaB pathway in the development of neuropathic pain after peripheral nerve injury.

Cloning of synthetic gene including antigens against Urinary Tract Infections in pET28a+ vector

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Zohreh Haghri

2017-12-01

Full Text Available There are many different bacterial infections in the world that patients are suffering from and research teams are trying to find suitable ways to prevent and treat them. Urinary Tract Infections (UTIs are most important infections in the world , and they are more common among women because vaginal cavity is near to urethral opening. The aim of this study is cloning of synthetic gene include antigens against UTIs in pET28a+ vector. Antibiotic resistant has been increasing because of antibiotic overuse recently, so It shows the necessity of developing a vaccine against these infections. There for, it will be imperative to develop a vaccine instead of antibiotics. This infection causes by many organisms, most important of which are Uropathogenic Escherichia coli (UPEC, Proteus mirabilis and Klebsiella pneumoniae Uropathogenic Escherichia .coli is the most important microorganism that causes these infections more than other bacteria, so in developing a vaccine it is the most important one, that have to be considered. The synthetic Gene which was designed against these three bacteria including antigens which are important and common to cause these infections. This gene has involved 1293bp. It was ordered to Gene Ray Biotechnology. Primers were designed by Gene Runner. Gene and pET28a+ vector was checked by SnappGene. Synthetic gene was multiplied by PCR and cloned in pET28a+ vector. Construct was transformed into E. coli TOP10.The clone was confirmed by PCR, Digestion. This data indicates that this gene can be expressed and it might be a vaccine candidate to protect people from these infections in the future.

“Marker of Self” CD47 on lentiviral vectors decreases macrophage-mediated clearance and increases delivery to SIRPA-expressing lung carcinoma tumors

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Nisha G Sosale

2016-01-01

Full Text Available Lentiviruses infect many cell types and are now widely used for gene delivery in vitro, but in vivo uptake of these foreign vectors by macrophages is a limitation. Lentivectors are produced here from packaging cells that overexpress “Marker of Self” CD47, which inhibits macrophage uptake of cells when prophagocytic factors are also displayed. Single particle analyses show “hCD47-Lenti” display properly oriented human-CD47 for interactions with the macrophage's inhibitory receptor SIRPA. Macrophages derived from human and NOD/SCID/Il2rg−/− (NSG mice show a SIRPA-dependent decrease in transduction, i.e., transgene expression, by hCD47-Lenti compared to control Lenti. Consistent with known “Self” signaling pathways, macrophage transduction by control Lenti is decreased by drug inhibition of Myosin-II to the same levels as hCD47-Lenti. In contrast, human lung carcinoma cells express SIRPA and use it to enhance transduction by hCD47-Lenti- as illustrated by more efficient gene deletion using CRISPR/Cas9. Intravenous injection of hCD47-Lenti into NSG mice shows hCD47 prolongs circulation, unless a blocking anti-SIRPA is preinjected. In vivo transduction of spleen and liver macrophages also decreases for hCD47-Lenti while transduction of lung carcinoma xenografts increases. hCD47 could be useful when macrophage uptake is limiting on other viral vectors that are emerging in cancer treatments (e.g., Measles glycoprotein-pseudotyped lentivectors and also in targeting various SIRPA-expressing tumors such as glioblastomas.

Transient foreign gene expression in chloroplasts of cultured tobacco cells after biolistic delivery of chloroplast vectors.

OpenAIRE

Daniell, H; Vivekananda, J; Nielsen, B L; Ye, G N; Tewari, K K; Sanford, J C

1990-01-01

Expression of chloramphenicol acetyltransferase (cat) by suitable vectors in chloroplasts of cultured tobacco cells, delivered by high-velocity microprojectiles, is reported here. Several chloroplast expression vectors containing bacterial cat genes, placed under the control of either psbA promoter region from pea (pHD series) or rbcL promoter region from maize (pAC series) have been used in this study. In addition, chloroplast expression vectors containing replicon fragments from pea, tobacc...

CRISPR/Cas9 delivery with one single adenoviral vector devoid of all viral genes.

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Ehrke-Schulz, Eric; Schiwon, Maren; Leitner, Theo; Dávid, Stephan; Bergmann, Thorsten; Liu, Jing; Ehrhardt, Anja

2017-12-07

The Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas9 system revolutionized the field of gene editing but viral delivery of the CRISPR/Cas9 system has not been fully explored. Here we adapted clinically relevant high-capacity adenoviral vectors (HCAdV) devoid of all viral genes for the delivery of the CRISPR/Cas9 machinery using a single viral vector. We present a platform enabling fast transfer of the Cas9 gene and gRNA expression units into the HCAdV genome including the option to choose between constitutive or inducible Cas9 expression and gRNA multiplexing. Efficacy and versatility of this pipeline was exemplified by producing different CRISPR/Cas9-HCAdV targeting the human papillomavirus (HPV) 18 oncogene E6, the dystrophin gene causing Duchenne muscular dystrophy (DMD) and the HIV co-receptor C-C chemokine receptor type 5 (CCR5). All CRISPR/Cas9-HCAdV proved to be efficient to deliver the respective CRISPR/Cas9 expression units and to introduce the desired DNA double strand breaks at their intended target sites in immortalized and primary cells.

A genome-wide analysis of lentivector integration sites using targeted sequence capture and next generation sequencing technology.

Science.gov (United States)

Ustek, Duran; Sirma, Sema; Gumus, Ergun; Arikan, Muzaffer; Cakiris, Aris; Abaci, Neslihan; Mathew, Jaicy; Emrence, Zeliha; Azakli, Hulya; Cosan, Fulya; Cakar, Atilla; Parlak, Mahmut; Kursun, Olcay

2012-10-01

One application of next-generation sequencing (NGS) is the targeted resequencing of interested genes which has not been used in viral integration site analysis of gene therapy applications. Here, we combined targeted sequence capture array and next generation sequencing to address the whole genome profiling of viral integration sites. Human 293T and K562 cells were transduced with a HIV-1 derived vector. A custom made DNA probe sets targeted pLVTHM vector used to capture lentiviral vector/human genome junctions. The captured DNA was sequenced using GS FLX platform. Seven thousand four hundred and eighty four human genome sequences flanking the long terminal repeats (LTR) of pLVTHM fragment sequences matched with an identity of at least 98% and minimum 50 bp criteria in both cells. In total, 203 unique integration sites were identified. The integrations in both cell lines were totally distant from the CpG islands and from the transcription start sites and preferentially located in introns. A comparison between the two cell lines showed that the lentiviral-transduced DNA does not have the same preferred regions in the two different cell lines. Copyright © 2012 Elsevier B.V. All rights reserved.

Partial Correction of Psoriasis upon Genetic Knock-Down of Human TNF-α by Lentivirus-Encoded shRNAs in a Xenograft Mouse Model

DEFF Research Database (Denmark)

Jakobsen, Maria; Stenderup, Karin; Rosada, Cecilia

samples treated with irrelevant shRNAs, were selected and cloned into lentiviral vectors. The lentiviral vectors expressing TNF- shRNAs were used to transduce HEK-293 cells and verify vector-derived knock-down of stable TNF- expression in vitro. The most efficient TNF- -directed shRNA, which in cell lines...

Virus-induced gene silencing in diverse maize lines using the Brome Mosaic virus-based silencing vector

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Virus-induced gene silencing (VIGS) is a widely used tool for gene function studies in many plant species, though its use in monocots has been limited. Using a Brome mosaic virus (BMV) vector designed to silence the maize phytoene desaturase gene, a genetically diverse set of maize inbred lines was ...

Low-Dose Gene Therapy for Murine PKU Using Episomal Naked DNA Vectors Expressing PAH from Its Endogenous Liver Promoter

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Hiu Man Grisch-Chan

2017-06-01

Full Text Available Limited duration of transgene expression, insertional mutagenesis, and size limitations for transgene cassettes pose challenges and risk factors for many gene therapy vectors. Here, we report on physiological expression of liver phenylalanine hydroxylase (PAH by delivery of naked DNA/minicircle (MC-based vectors for correction of homozygous enu2 mice, a model of human phenylketonuria (PKU. Because MC vectors lack a defined size limit, we constructed a MC vector expressing a codon-optimized murine Pah cDNA that includes a truncated intron and is under the transcriptional control of a 3.6-kb native Pah promoter/enhancer sequence. This vector, delivered via hydrodynamic injection, yielded therapeutic liver PAH activity and sustained correction of blood phenylalanine comparable to viral or synthetic liver promoters. Therapeutic efficacy was seen with vector copy numbers of 95% loss of vector genomes and PAH activity in liver, demonstrating that MC vectors had not integrated into the liver genome. In conclusion, MC vectors, which do not have a defined size-limitation, offer a favorable safety profile for hepatic gene therapy due to their non-integration in combination with native promoters.

Construction of novel shuttle expression vectors for gene expression in Bacillus subtilis and Bacillus pumilus.

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Shao, Huanhuan; Cao, Qinghua; Zhao, Hongyan; Tan, Xuemei; Feng, Hong

2015-01-01

A native plasmid (pSU01) was detected by genome sequencing of Bacillus subtilis strain S1-4. Two pSU01-based shuttle expression vectors pSU02-AP and pSU03-AP were constructed enabling stable replication in B. subtilis WB600. These vectors contained the reporter gene aprE, encoding an alkaline protease from Bacillus pumilus BA06. The expression vector pSU03-AP only possessed the minimal replication elements (rep, SSO, DSO) and exhibited more stability on structure, suggesting that the rest of the genes in pSU01 (ORF1, ORF2, mob, hsp) were unessential for the structural stability of plasmid in B. subtilis. In addition, recombinant production of the alkaline protease was achieved more efficiently with pSU03-AP whose copy number was estimated to be more than 100 per chromosome. Furthermore, pSU03-AP could also be used to transform and replicate in B. pumilus BA06 under selective pressure. In conclusion, pSU03-AP is expected to be a useful tool for gene expression in Bacillus subtilis and B. pumilus.

Have we found an optimal insertion site in a Newcastle disease virus vector to express a foreign gene for vaccine and gene therapy purposes?

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Using reverse genetics technology, many strains of Newcastle disease virus (NDV) have been developed as vectors to express foreign genes for vaccine and gene therapy purposes. The foreign gene is usually inserted into a non-coding region of the NDV genome as an independent transcription unit. Eval...

Dual delivery systems based on polyamine analog BENSpm as prodrug and gene delivery vectors

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Zhu, Yu

Combination drug and gene therapy shows promise in cancer treatment. However, the success of such strategy requires careful selection of the therapeutic agents, as well as development of efficient delivery vectors. BENSpm (N 1, N11-bisethylnorspermine), a polyamine analogue targeting the intracellular polyamine pathway, draws our special attention because of the following reasons: (1) polyamine pathway is frequently dysregulated in cancer; (2) BENSpm exhibits multiple functions to interfere with the polyamine pathway, such as to up-regulate polyamine metabolism enzymes and down-regulate polyamine biosynthesis enzymes. Therefore BENSpm depletes all natural polyamines and leads to apoptosis and cell growth inhibition in a wide range of cancers; (3) preclinical studies proved that BENSpm can act synergistically with various chemotherapy agents, making it a promising candidate in combination therapy; (4) multiple positive charges in BENSpm enable it as a suitable building block for cationic polymers, which can be further applied to gene delivery. In this dissertation, our goal was to design dual-function delivery vector based on BENSpm that can function as a gene delivery vector and, after intracellular degradation, as an active anticancer agent targeting dysregulated polyamine metabolism. We first demonstrated strong synergism between BENSpm and a potential therapeutic gene product TRAIL. Strong synergism was obtained in both estrogen-dependent MCF-7 breast cancer cells and triple-negative MDA-MB-231 breast cancer cells. Significant dose reduction of TRAIL in combination with BENSpm in MDA-MB-231 cells, together with the fact that BENSpm rendered MCF-7 cells more sensitive to TRAIL treatment verified our rationale of designing BENSpm-based delivery platform. This was expected to be beneficial for overcoming drug resistance in chemotherapy, as well as boosting the therapeutic effect of therapeutic genes. We first designed a lipid-based BENSpm dual vector (Lipo

Widespread and highly persistent gene transfer to the CNS by retrovirus vector in utero: implication for gene therapy to Krabbe disease.

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Shen, Jin-Song; Meng, Xing-Li; Yokoo, Takashi; Sakurai, Ken; Watabe, Kazuhiko; Ohashi, Toya; Eto, Yoshikatsu

2005-05-01

Brain-directed prenatal gene therapy may benefit some lysosomal storage diseases that affect the central nervous system (CNS) before birth. Our previous study showed that intrauterine introduction of recombinant adenoviruses into cerebral ventricles results in efficient gene transfer to the CNS in the mouse. However, transgene expression decreased with time due to the non-integrative property of adenoviral vectors. In this study, in order to obtain permanent gene transduction, we investigated the feasibility of retrovirus-mediated in utero gene transduction. Concentrated retrovirus encoding the LacZ gene was injected into the cerebral ventricles of the embryos of normal and twitcher mice (a murine model of Krabbe disease) at embryonic day 12. The distribution and maintenance of the transgene expression in the recipient brain were analyzed histochemically, biochemically and by the quantitative polymerase chain reaction method pre- and postnatally. Efficient and highly persistent gene transduction to the brain was achieved both in normal and the twitcher mouse. Transduced neurons, astrocytes and oligodendrocytes were distributed throughout the brain. The transduced LacZ gene, its transcript and protein expression in the brain were maintained for 14 months without decrement. In addition, gene transduction to multiple tissues other than the brain was also detected at low levels. This study suggests that brain-directed in utero gene transfer using retrovirus vector may be beneficial to the treatment of lysosomal storage diseases with severe brain damage early in life, such as Krabbe disease. Copyright (c) 2005 John Wiley & Sons, Ltd.

Ex Vivo Gene Therapy Using Human Mesenchymal Stem Cells to Deliver Growth Factors in the Skeletal Muscle of a Familial ALS Rat Model.

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Suzuki, Masatoshi; Svendsen, Clive N

2016-01-01

Therapeutic protein and molecule delivery to target sites by transplanted human stem cells holds great promise for ex vivo gene therapy. Our group has demonstrated the therapeutic benefits of ex vivo gene therapy targeting the skeletal muscles in a transgenic rat model of familial amyotrophic lateral sclerosis (ALS). We used human mesenchymal stem cells (hMSCs) and genetically modified them to release neuroprotective growth factors such as glial cell line-derived neurotrophic factor (GDNF) and vascular endothelial growth factor (VEGF). Intramuscular growth factor delivery via hMSCs can enhance neuromuscular innervation and motor neuron survival in a rat model of ALS (SOD1(G93A) transgenic rats). Here, we describe the protocol of ex vivo delivery of growth factors via lentiviral vector-mediated genetic modification of hMSCs and hMSC transplantation into the skeletal muscle of a familial ALS rat model.

An efficient deletion mutant packaging system for defective herpes simplex virus vectors: Potential applications to human gene therapy and neuronal physiology

International Nuclear Information System (INIS)

Geller, A.I.; Keyomarsi, K.; Bryan, J.; Pardee, A.B.

1990-01-01

The authors have previously described a defective herpes simplex virus (HSV-1) vector system that permits that introduction of virtually any gene into nonmitotic cells. pHSVlac, the prototype vector, stably expresses Escherichia coli β-galactosidase from a constitutive promoter in many human cell lines, in cultured rat neurons from throughout the nervous system, and in cells in the adult rat brain. HSV-1 vectors expressing other genes may prove useful for studying neuronal physiology or performing human gene therapy for neurological diseases, such as Parkinson disease or brain tumors. A HSV-1 temperature-sensitive (ts) mutant, ts K, has been used as helper virus; ts mutants revert to wild type. In contrast, HSV-1 deletion mutants essentially cannot revert to wild type; therefore, use of a deletion mutant as helper virus might permit human gene therapy with HSV-1 vectors. They now report an efficient packaging system for HSV-1 VECTORS USING A DELETION MUTANT, d30EBA, as helper virus; virus is grown on the complementing cell line M64A. pHSVlac virus prepared using the deletion mutant packaging system stably expresses β-galactosidase in cultured rat sympathetic neurons and glia. Both D30EBA and ts K contain a mutation in the IE3 gene of HSV-1 strain 17 and have the same phenotype; therefore, changing the helper virus from ts K to D30EBA does not alter the host range or other properties of the HSV-1 vector system

[Construction of the eukaryotic recombinant vector and expression of the outer membrane protein LipL32 gene from Leptospira serovar Lai].

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Huang, Bi; Bao, Lang; Zhong, Qi; Shang, Zheng-ling; Zhang, Hui-dong; Zhang, Ying

2008-02-01

To construct the eukaryotic experssion vector of LipL32 gene from Leptospira serovar Lai and express the recombinant plasmid in COS-7 cell. The LipL32 gene was amplified from Leptospira strain 017 genomic DNA by PCR and cloned into pcDNA3.1, through restriction nuclease enzyme digestion. Then the recombinant plasmid was transformed into E.coli DH5alpha. After identified by nuclease digestion, PCR and sequencing analysis, the recombinant vector was transfected into COS-7 cell with lipsome. The expression of the target gene was detected by RT-PCR and Western blot. The eukaryotic experssion vector pcDNA3.1-LipL32 was successfully constructed and stably expressed in COS-7 cell. The eukaryotic recombinant vector of outer membrane protein LipL32 gene from Leptospira serovar Lai can be expressed in mammalian cell, which provides an experimental basis for the application of the Leptospira DNA vaccine.

Engineering and Validation of a Vector for Concomitant Expression of Rare Transfer RNA (tRNA and HIV-1 nef Genes in Escherichia coli.

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Siti Aisyah Mualif

Full Text Available Relative ease in handling and manipulation of Escherichia coli strains make them primary candidate to express proteins heterologously. Overexpression of heterologous genes that contain codons infrequently used by E. coli is related with difficulties such as mRNA instability, early termination of transcription and/or translation, deletions and/or misincorporation, and cell growth inhibition. These codon bias -associated problems are addressed by co-expressing ColE1-compatible, rare tRNA expressing helper plasmids. However, this approach has inadequacies, which we have addressed by engineering an expression vector that concomitantly expresses the heterologous protein of interest, and rare tRNA genes in E. coli. The expression vector contains three (argU, ileY, leuW rare tRNA genes and a useful multiple cloning site for easy in-frame cloning. To maintain the overall size of the parental plasmid vector, the rare tRNA genes replaced the non-essential DNA segments in the vector. The cloned gene is expressed under the control of T7 promoter and resulting recombinant protein has a C-terminal 6His tag for IMAC-mediated purification. We have evaluated the usefulness of this expression vector by expressing three HIV-1 genes namely HIV-1 p27 (nef, HIV-1 p24 (ca, and HIV-1 vif in NiCo21(DE3 E.coli and demonstrated the advantages of using expression vector that concomitantly expresses rare tRNA and heterologous genes.

Efficient Ex Vivo Engineering and Expansion of Highly Purified Human Hematopoietic Stem and Progenitor Cell Populations for Gene Therapy.

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Zonari, Erika; Desantis, Giacomo; Petrillo, Carolina; Boccalatte, Francesco E; Lidonnici, Maria Rosa; Kajaste-Rudnitski, Anna; Aiuti, Alessandro; Ferrari, Giuliana; Naldini, Luigi; Gentner, Bernhard

2017-04-11

Ex vivo gene therapy based on CD34 + hematopoietic stem cells (HSCs) has shown promising results in clinical trials, but genetic engineering to high levels and in large scale remains challenging. We devised a sorting strategy that captures more than 90% of HSC activity in less than 10% of mobilized peripheral blood (mPB) CD34 + cells, and modeled a transplantation protocol based on highly purified, genetically engineered HSCs co-infused with uncultured progenitor cells. Prostaglandin E 2 stimulation allowed near-complete transduction of HSCs with lentiviral vectors during a culture time of less than 38 hr, mitigating the negative impact of standard culture on progenitor cell function. Exploiting the pyrimidoindole derivative UM171, we show that transduced mPB CD34 + CD38 - cells with repopulating potential could be expanded ex vivo. Implementing these findings in clinical gene therapy protocols will improve the efficacy, safety, and sustainability of gene therapy and generate new opportunities in the field of gene editing. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Lentivector Integration Sites in Ependymal Cells From a Model of Metachromatic Leukodystrophy: Non-B DNA as a New Factor Influencing Integration

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McAllister, Robert G; Liu, Jiahui; Woods, Matthew W; Tom, Sean K; Rupar, C Anthony; Barr, Stephen D

2014-01-01

The blood–brain barrier controls the passage of molecules from the blood into the central nervous system (CNS) and is a major challenge for treatment of neurological diseases. Metachromatic leukodystrophy is a neurodegenerative lysosomal storage disease caused by loss of arylsulfatase A (ARSA) activity. Gene therapy via intraventricular injection of a lentiviral vector is a potential approach to rapidly and permanently deliver therapeutic levels of ARSA to the CNS. We present the distribution of integration sites of a lentiviral vector encoding human ARSA (LV-ARSA) in murine brain choroid plexus and ependymal cells, administered via a single intracranial injection into the CNS. LV-ARSA did not exhibit a strong preference for integration in or near actively transcribed genes, but exhibited a strong preference for integration in or near satellite DNA. We identified several genomic hotspots for LV-ARSA integration and identified a consensus target site sequence characterized by two G-quadruplex-forming motifs flanking the integration site. In addition, our analysis identified several other non-B DNA motifs as new factors that potentially influence lentivirus integration, including human immunodeficiency virus type-1 in human cells. Together, our data demonstrate a clinically favorable integration site profile in the murine brain and identify non-B DNA as a potential new host factor that influences lentiviral integration in murine and human cells. PMID:25158091

Tropism-Modification Strategies for Targeted Gene Delivery Using Adenoviral Vectors

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Andrew H. Baker

2010-10-01

Full Text Available Achieving high efficiency, targeted gene delivery with adenoviral vectors is a long-standing goal in the field of clinical gene therapy. To achieve this, platform vectors must combine efficient retargeting strategies with detargeting modifications to ablate native receptor binding (i.e. CAR/integrins/heparan sulfate proteoglycans and “bridging” interactions. “Bridging” interactions refer to coagulation factor binding, namely coagulation factor X (FX, which bridges hepatocyte transduction in vivo through engagement with surface expressed heparan sulfate proteoglycans (HSPGs. These interactions can contribute to the off-target sequestration of Ad5 in the liver and its characteristic dose-limiting hepatotoxicity, thereby significantly limiting the in vivo targeting efficiency and clinical potential of Ad5-based therapeutics. To date, various approaches to retargeting adenoviruses (Ad have been described. These include genetic modification strategies to incorporate peptide ligands (within fiber knob domain, fiber shaft, penton base, pIX or hexon, pseudotyping of capsid proteins to include whole fiber substitutions or fiber knob chimeras, pseudotyping with non-human Ad species or with capsid proteins derived from other viral families, hexon hypervariable region (HVR substitutions and adapter-based conjugation/crosslinking of scFv, growth factors or monoclonal antibodies directed against surface-expressed target antigens. In order to maximize retargeting, strategies which permit detargeting from undesirable interactions between the Ad capsid and components of the circulatory system (e.g. coagulation factors, erythrocytes, pre-existing neutralizing antibodies, can be employed simultaneously. Detargeting can be achieved by genetic ablation of native receptor-binding determinants, ablation of “bridging interactions” such as those which occur between the hexon of Ad5 and coagulation factor X (FX, or alternatively, through the use of polymer

Longevity of rAAV vector and plasmid DNA in blood after intramuscular injection in nonhuman primates: implications for gene doping.

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Ni, W; Le Guiner, C; Gernoux, G; Penaud-Budloo, M; Moullier, P; Snyder, R O

2011-07-01

Legitimate uses of gene transfer technology can benefit from sensitive detection methods to determine vector biodistribution in pre-clinical studies and in human clinical trials, and similar methods can detect illegitimate gene transfer to provide sports-governing bodies with the ability to maintain fairness. Real-time PCR assays were developed to detect a performance-enhancing transgene (erythropoietin, EPO) and backbone sequences in the presence of endogenous cellular sequences. In addition to developing real-time PCR assays, the steps involved in DNA extraction, storage and transport were investigated. By real-time PCR, the vector transgene is distinguishable from the genomic DNA sequence because of the absence of introns, and the vector backbone can be identified by heterologous gene expression control elements. After performance of the assays was optimized, cynomolgus macaques received a single dose by intramuscular (IM) injection of plasmid DNA, a recombinant adeno-associated viral vector serotype 1 (rAAV1) or a rAAV8 vector expressing cynomolgus macaque EPO. Macaques received a high plasmid dose intended to achieve a significant, but not life-threatening, increase in hematocrit. rAAV vectors were used at low doses to achieve a small increase in hematocrit and to determine the limit of sensitivity for detecting rAAV sequences by single-step PCR. DNA extracted from white blood cells (WBCs) was tested to determine whether WBCs can be collaterally transfected by plasmid or transduced by rAAV vectors in this context, and can be used as a surrogate marker for gene doping. We demonstrate that IM injection of a conventional plasmid and rAAV vectors results in the presence of DNA that can be detected at high levels in blood before rapid elimination, and that rAAV genomes can persist for several months in WBCs.

Mesenchymal stem cell-based NK4 gene therapy in nude mice bearing gastric cancer xenografts

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Zhu Y

2014-12-01

Full Text Available Yin Zhu,1,* Ming Cheng,2,* Zhen Yang,3 Chun-Yan Zeng,3 Jiang Chen,3 Yong Xie,3 Shi-Wen Luo,3 Kun-He Zhang,3 Shu-Feng Zhou,4 Nong-Hua Lu1,31Department of Gastroenterology, 2Department of Orthopedics, 3Institute of Digestive Disease, The First Affiliated Hospital of Nanchang University, Jiangxi, People’s Republic of China; 4Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA*These authors contributed equally to this workAbstract: Mesenchymal stem cells (MSCs have been recognized as promising delivery vehicles for gene therapy of tumors. Gastric cancer is the third leading cause of worldwide cancer mortality, and novel treatment modalities are urgently needed. NK4 is an antagonist of hepatocyte growth factor receptors (Met which are often aberrantly activated in gastric cancer and thus represent a useful candidate for targeted therapies. This study investigated MSC-delivered NK4 gene therapy in nude mice bearing gastric cancer xenografts. MSCs were transduced with lentiviral vectors carrying NK4 complementary DNA or enhanced green fluorescent protein (GFP. Such transduction did not change the phenotype of MSCs. Gastric cancer xenografts were established in BALB/C nude mice, and the mice were treated with phosphate-buffered saline (PBS, MSCs-GFP, Lenti-NK4, or MSCs-NK4. The tropism of MSCs toward gastric cancer cells was determined by an in vitro migration assay using MKN45 cells, GES-1 cells and human fibroblasts and their presence in tumor xenografts. Tumor growth, tumor cell apoptosis and intratumoral microvessel density of tumor tissue were measured in nude mice bearing gastric cancer xenografts treated with PBS, MSCs-GFP, Lenti-NK4, or MSCs-NK4 via tail vein injection. The results showed that MSCs migrated preferably to gastric cancer cells in vitro. Systemic MSCs-NK4 injection significantly suppressed the growth of gastric cancer xenografts. MSCs-NK4 migrated and accumulated in tumor

BDNF gene delivery within and beyond templated agarose multi-channel guidance scaffolds enhances peripheral nerve regeneration

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Gao, Mingyong; Lu, Paul; Lynam, Dan; Bednark, Bridget; Campana, W. Marie; Sakamoto, Jeff; Tuszynski, Mark

2016-12-01

Objective. We combined implantation of multi-channel templated agarose scaffolds with growth factor gene delivery to examine whether this combinatorial treatment can enhance peripheral axonal regeneration through long sciatic nerve gaps. Approach. 15 mm long scaffolds were templated into highly organized, strictly linear channels, mimicking the linear organization of natural nerves into fascicles of related function. Scaffolds were filled with syngeneic bone marrow stromal cells (MSCs) secreting the growth factor brain derived neurotrophic factor (BDNF), and lentiviral vectors expressing BDNF were injected into the sciatic nerve segment distal to the scaffold implantation site. Main results. Twelve weeks after injury, scaffolds supported highly linear regeneration of host axons across the 15 mm lesion gap. The incorporation of BDNF-secreting cells into scaffolds significantly increased axonal regeneration, and additional injection of viral vectors expressing BDNF into the distal segment of the transected nerve significantly enhanced axonal regeneration beyond the lesion. Significance. Combinatorial treatment with multichannel bioengineered scaffolds and distal growth factor delivery significantly improves peripheral nerve repair, rivaling the gold standard of autografts.

Direct lentiviral-cyclooxygenase 2 application to the tendon-bone interface promotes osteointegration and enhances return of the pull-out tensile strength of the tendon graft in a rat model of biceps tenodesis.

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Charles H Rundle

Full Text Available This study sought to determine if direct application of the lentiviral (LV-cyclooxygenase 2 (COX2 vector to the tendon-bone interface would promote osteointegration of the tendon graft in a rat model of biceps tenodesis. The LV-COX2 gene transfer strategy was chosen for investigation because a similar COX2 gene transfer strategy promoted bony bridging of the fracture gap during bone repair, which involves similar histologic transitions that occur in osteointegration. Briefly, a 1.14-mm diameter tunnel was drilled in the mid-groove of the humerus of adult Fischer 344 rats. The LV-COX2 or βgal control vector was applied directly into the bone tunnel and onto the end of the tendon graft, which was then pulled into the bone tunnel. A poly-L-lactide pin was press-fitted into the tunnel as interference fixation. Animals were sacrificed at 3, 5, or 8 weeks for histology analysis of osteointegration. The LV-COX2 gene transfer strategy enhanced neo-chondrogenesis at the tendon-bone interface but with only marginal effect on de novo bone formation. The tendon-bone interface of the LV-COX2-treated tenodesis showed the well-defined tendon-to-fibrocartilage-to-bone histologic transitions that are indicative of osteointegration of the tendon graft. The LV-COX2 in vivo gene transfer strategy also significantly enhanced angiogenesis at the tendon-bone interface. To determine if the increased osteointegration was translated into an improved pull-out mechanical strength property, the pull-out tensile strength of the LV-COX2-treated tendon grafts was determined with a pull-out mechanical testing assay. The LV-COX2 strategy yielded a significant improvement in the return of the pull-out strength of the tendon graft after 8 weeks. In conclusion, the COX2-based in vivo gene transfer strategy enhanced angiogenesis, osteointegration and improved return of the pull-out strength of the tendon graft. Thus, this strategy has great potential to be developed into an

Generation of a Vero-Based Packaging Cell Line to Produce SV40 Gene Delivery Vectors for Use in Clinical Gene Therapy Studies

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Miguel G. Toscano

2017-09-01

Full Text Available Replication-defective (RD recombinant simian virus 40 (SV40-based gene delivery vectors hold a great potential for clinical applications because of their presumed non-immunogenicity and capacity to induce immune tolerance to the transgene products in humans. However, the clinical use of SV40 vectors has been hampered by the lack of a packaging cell line that produces replication-competent (RC free SV40 particles in the vector production process. To solve this problem, we have adapted the current SV40 vector genome used for the production of vector particles and generated a novel Vero-based packaging cell line named SuperVero that exclusively expresses the SV40 large T antigen. SuperVero cells produce similar numbers of SV40 vector particles compared to the currently used packaging cell lines, albeit in the absence of contaminating RC SV40 particles. Our unique SV40 vector platform named SVac paves the way to clinically test a whole new generation of SV40-based therapeutics for a broad range of important diseases.

TALEN-Based Gene Disruption in the Dengue Vector Aedes aegypti

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Aryan, Azadeh; Anderson, Michelle A. E.; Myles, Kevin M.; Adelman, Zach N.

2013-01-01

In addition to its role as the primary vector for dengue viruses, Aedes aegypti has a long history as a genetic model organism for other bloodfeeding mosquitoes, due to its ease of colonization, maintenance and reproductive productivity. Though its genome has been sequenced, functional characterization of many Ae. aegypti genes, pathways and behaviors has been slow. TALE nucleases (TALENs) have been used with great success in a number of organisms to generate site-specific DNA lesions. We evaluated the ability of a TALEN pair to target the Ae. aegypti kmo gene, whose protein product is essential in the production of eye pigmentation. Following injection into pre-blastoderm embryos, 20–40% of fertile survivors produced kmo alleles that failed to complement an existing khw mutation. Most of these individuals produced more than 20% white-eyed progeny, with some producing up to 75%. Mutant alleles were associated with lesions of 1–7 bp specifically at the selected target site. White-eyed individuals could also be recovered following a blind intercross of G1 progeny, yielding several new white-eyed strains in the genetic background of the sequenced Liverpool strain. We conclude that TALENs are highly active in the Ae. aegypti germline, and have the potential to transform how reverse genetic experiments are performed in this important disease vector. PMID:23555893

TALEN-based gene disruption in the dengue vector Aedes aegypti.

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Azadeh Aryan

Full Text Available In addition to its role as the primary vector for dengue viruses, Aedes aegypti has a long history as a genetic model organism for other bloodfeeding mosquitoes, due to its ease of colonization, maintenance and reproductive productivity. Though its genome has been sequenced, functional characterization of many Ae. aegypti genes, pathways and behaviors has been slow. TALE nucleases (TALENs have been used with great success in a number of organisms to generate site-specific DNA lesions. We evaluated the ability of a TALEN pair to target the Ae. aegypti kmo gene, whose protein product is essential in the production of eye pigmentation. Following injection into pre-blastoderm embryos, 20-40% of fertile survivors produced kmo alleles that failed to complement an existing kh(w mutation. Most of these individuals produced more than 20% white-eyed progeny, with some producing up to 75%. Mutant alleles were associated with lesions of 1-7 bp specifically at the selected target site. White-eyed individuals could also be recovered following a blind intercross of G1 progeny, yielding several new white-eyed strains in the genetic background of the sequenced Liverpool strain. We conclude that TALENs are highly active in the Ae. aegypti germline, and have the potential to transform how reverse genetic experiments are performed in this important disease vector.

TALEN-based gene disruption in the dengue vector Aedes aegypti.

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Aryan, Azadeh; Anderson, Michelle A E; Myles, Kevin M; Adelman, Zach N

2013-01-01

In addition to its role as the primary vector for dengue viruses, Aedes aegypti has a long history as a genetic model organism for other bloodfeeding mosquitoes, due to its ease of colonization, maintenance and reproductive productivity. Though its genome has been sequenced, functional characterization of many Ae. aegypti genes, pathways and behaviors has been slow. TALE nucleases (TALENs) have been used with great success in a number of organisms to generate site-specific DNA lesions. We evaluated the ability of a TALEN pair to target the Ae. aegypti kmo gene, whose protein product is essential in the production of eye pigmentation. Following injection into pre-blastoderm embryos, 20-40% of fertile survivors produced kmo alleles that failed to complement an existing kh(w) mutation. Most of these individuals produced more than 20% white-eyed progeny, with some producing up to 75%. Mutant alleles were associated with lesions of 1-7 bp specifically at the selected target site. White-eyed individuals could also be recovered following a blind intercross of G1 progeny, yielding several new white-eyed strains in the genetic background of the sequenced Liverpool strain. We conclude that TALENs are highly active in the Ae. aegypti germline, and have the potential to transform how reverse genetic experiments are performed in this important disease vector.

TimesVector: a vectorized clustering approach to the analysis of time series transcriptome data from multiple phenotypes.

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Jung, Inuk; Jo, Kyuri; Kang, Hyejin; Ahn, Hongryul; Yu, Youngjae; Kim, Sun

2017-12-01

Identifying biologically meaningful gene expression patterns from time series gene expression data is important to understand the underlying biological mechanisms. To identify significantly perturbed gene sets between different phenotypes, analysis of time series transcriptome data requires consideration of time and sample dimensions. Thus, the analysis of such time series data seeks to search gene sets that exhibit similar or different expression patterns between two or more sample conditions, constituting the three-dimensional data, i.e. gene-time-condition. Computational complexity for analyzing such data is very high, compared to the already difficult NP-hard two dimensional biclustering algorithms. Because of this challenge, traditional time series clustering algorithms are designed to capture co-expressed genes with similar expression pattern in two sample conditions. We present a triclustering algorithm, TimesVector, specifically designed for clustering three-dimensional time series data to capture distinctively similar or different gene expression patterns between two or more sample conditions. TimesVector identifies clusters with distinctive expression patterns in three steps: (i) dimension reduction and clustering of time-condition concatenated vectors, (ii) post-processing clusters for detecting similar and distinct expression patterns and (iii) rescuing genes from unclassified clusters. Using four sets of time series gene expression data, generated by both microarray and high throughput sequencing platforms, we demonstrated that TimesVector successfully detected biologically meaningful clusters of high quality. TimesVector improved the clustering quality compared to existing triclustering tools and only TimesVector detected clusters with differential expression patterns across conditions successfully. The TimesVector software is available at http://biohealth.snu.ac.kr/software/TimesVector/. sunkim.bioinfo@snu.ac.kr. Supplementary data are available at

Large-scale chondroitin sulfate proteoglycan digestion with chondroitinase gene therapy leads to reduced pathology and modulates macrophage phenotype following spinal cord contusion injury

NARCIS (Netherlands)

Bartus, Katalin; James, Nicholas D; Didangelos, Athanasios; Bosch, Karen D; Verhaagen, J.; Yáñez-Muñoz, Rafael J; Rogers, John H; Schneider, Bernard L; Muir, Elizabeth M; Bradbury, Elizabeth J

2014-01-01

Chondroitin sulfate proteoglycans (CSPGs) inhibit repair following spinal cord injury. Here we use mammalian-compatible engineered chondroitinase ABC (ChABC) delivered via lentiviral vector (LV-ChABC) to explore the consequences of large-scale CSPG digestion for spinal cord repair. We demonstrate

Development of a multiple-gene-loading method by combining multi-integration system-equipped mouse artificial chromosome vector and CRISPR-Cas9.

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Kazuhisa Honma

Full Text Available Mouse artificial chromosome (MAC vectors have several advantages as gene delivery vectors, such as stable and independent maintenance in host cells without integration, transferability from donor cells to recipient cells via microcell-mediated chromosome transfer (MMCT, and the potential for loading a megabase-sized DNA fragment. Previously, a MAC containing a multi-integrase platform (MI-MAC was developed to facilitate the transfer of multiple genes into desired cells. Although the MI system can theoretically hold five gene-loading vectors (GLVs, there are a limited number of drugs available for the selection of multiple-GLV integration. To overcome this issue, we attempted to knock out and reuse drug resistance genes (DRGs using the CRISPR-Cas9 system. In this study, we developed new methods for multiple-GLV integration. As a proof of concept, we introduced five GLVs in the MI-MAC by these methods, in which each GLV contained a gene encoding a fluorescent or luminescent protein (EGFP, mCherry, BFP, Eluc, and Cluc. Genes of interest (GOI on the MI-MAC were expressed stably and functionally without silencing in the host cells. Furthermore, the MI-MAC carrying five GLVs was transferred to other cells by MMCT, and the resultant recipient cells exhibited all five fluorescence/luminescence signals. Thus, the MI-MAC was successfully used as a multiple-GLV integration vector using the CRISPR-Cas9 system. The MI-MAC employing these methods may resolve bottlenecks in developing multiple-gene humanized models, multiple-gene monitoring models, disease models, reprogramming, and inducible gene expression systems.

Vector for IS element entrapment and functional characterization based on turning on expression of distal promoterless genes.

Science.gov (United States)

Szeverényi, I; Hodel, A; Arber, W; Olasz, F

1996-09-26

We constructed and characterized a novel trap vector for rapid isolation of insertion sequences. The strategy used for the isolation of IS elements is based on the ability of many IS elements to turn on the expression of otherwise silent genes distal to some sites of insertion. The simple transposition of an IS element can sometimes cause the constitutive expression of promoterless antibiotic resistance genes resulting in selectable phenotypes. The trap vector pAW1326 is based on a pBR322 replicon, it carries ampicillin and streptomycin resistance genes, and also silenced genes that confer chloramphenicol and kanamycin resistance once activated. The trap vector pAW1326 proved to be efficient and 85 percent of all isolated mutations were insertions. The majority of IS elements resident in the studied Escherichia coli strains tested became trapped, namely IS2, IS3, IS5, IS150, IS186 and Tn1000. We also encountered an insertion sequence, called IS10L/R-2, which is a hybrid of the two IS variants IS10L and IS10R. IS10L/R-2 is absent from most E. coli strains, but it is detectable in some strains such as JM109 which had been submitted to Tn10 mutagenesis. The distribution of the insertion sequences within the trap region was not random. Rather, the integration of chromosomal mobile genetic elements into the offered target sequence occurred in element-specific clusters. This is explained both by the target specificity and by the specific requirements for the activation of gene transcription by the DNA rearrangement. The employed trap vector pAW1326 proved to be useful for the isolation of mobile genetic elements, for a demonstration of their transposition activity as well as for the further characterization of some of the functional parameters of transposition.

Efficient gene transfer into lymphoma cells using adenoviral vectors combined with lipofection.

Science.gov (United States)

Buttgereit, P; Weineck, S; Röpke, G; Märten, A; Brand, K; Heinicke, T; Caselmann, W H; Huhn, D; Schmidt-Wolf, I G

2000-08-01

Tumor cells, such as lymphoma cells, are possible targets for gene therapy. In general, gene therapeutic approaches require efficient gene transfer to host cells and sufficient transgene expression. However, lymphoma cells previously have been demonstrated to be resistant to most of the currently available gene transfer methods. The aim of this study was to analyze various methods for transfection of lymphoma cells and to improve the efficiency of gene delivery. In accordance with previously published reports, lymphoma cells were demonstrated to be resistant to lipofection and electroporation. In contrast, we present an improved adenoviral protocol leading to highly efficient gene transfer to lymphoma cell lines derived from B cells as well as primary lymphoma cells being achieved with an adenoviral vector system encoding the beta-galactosidase protein. At a multiplicity of infection of 200, up to 100% of Daudi cells and Raji cells and 70% of OCI-Ly8-LAM53 cells could be transfected. Even at high adenoviral concentrations, no marked toxicity was observed, and the growth characteristics of the lymphoma cell lines were not impaired. The transfection rates in primary cells derived from six patients with non-Hodgkin's lymphoma were 30-65%, respectively. Transfection efficiency could be further increased by addition of cationic liposomes to adenoviral gene transfer. Furthermore, we examined the expression of the Coxsackie-adenoviral receptor (CAR) and the integrin receptors on the lymphoma cell surface. Flow cytometric analysis showed that 88% of Daudi cells, 69% of Raji cells, and 6% of OCI-Ly8-LAM53 cells expressed CAR on the cell surface. According to our data, adenoviral infection of lymphoma cells seems to be mediated by CAR. In contrast, integrin receptors are unlikely to play a major role, because lymphoma cells were negative for alphavbeta3-integrins and negative for alphavbeta5-integrins. In conclusion, this study demonstrates that B-lymphoma cell lines and

[Selection and construction of cell line stably expressing survivin gene in lower level through eukaryotic plasmid vector of shRNA].

Science.gov (United States)

Wang, Wen-Xia; Sun, Shan-Zhen; Song, Ying

2008-06-01

To construct a short hairpin RNA(shRNA) interference expression plasmid vector of survivin gene, transfect tongue squamous cell carcinoma line Tca8113 which expressed survivin gene in a high level, and choose the cells whose survivin gene were suppressed significantly. Two pairs of oligonucleotide sequences specific for survivin gene were designed and synthesized, and cloned into pSilencer-2.1U6-neo plasmid. The recombinant plasmids (named PS1 and PS2) were amplified in Ecoli. DH5alpha was identified by restriction digestion, PCR and sequencing. The vectors were transfected into Tca8113 cells with lipofectamine 2000. After selection with G418, the stable cell clones were attained. Survivn expression was assayed with real-time quantitative PCR and Western blotting. SAS8.0 software package was used for Student t test. Two vectors were constructed successfully and stable cell clones with PS1 or PS2 plasmid were obtained. As compared with those of control, survivin expression of transfected cell with PS1 or PS2 in mRNA level was significantly suppressed (P<0.05). In protein level, only those of transfected cell with PS2 was significantly suppressed (P<0.01). The shRNA interference expression plasmid vectors of survivin gene are successfully constructed, and Tca8113 cells which express survivin gene in a stable lower level are attained, which enable us to carry out further research on gene therapy of oral squamous cell carcinoma. Supported by National Natural Science Foundation of China (Grant No.30572056).

Polybrene inhibits human mesenchymal stem cell proliferation during lentiviral transduction.

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Paul Lin

Full Text Available Human mesenchymal stem cells (hMSCs can be engineered to express specific genes, either for their use in cell-based therapies or to track them in vivo over long periods of time. To obtain long-term expression of these genes, a lentivirus- or retrovirus-mediated cell transduction is often used. However, given that the efficiency with these viruses is typically low in primary cells, additives such as polybrene are always used for efficient viral transduction. Unfortunately, as presented here, exposure to polybrene alone at commonly used concentratons (1-8 µg/mL negatively impacts hMSC proliferation in a dose-dependent manner as measured by CyQUANT, EdU incorporation, and cell cycle analysis. This inhibition of proliferation was observable in culture even 3 weeks after exposure. Culturing the cells in the presence of FGF-2, a potent mitogen, did not abrogate this negative effect of polybrene. In fact, the normally sharp increase in hMSC proliferation that occurs during the first days of exposure to FGF-2 was absent at 4 µg/mL or higher concentrations of polybrene. Similarly, the effect of stimulating cell proliferation under simulated hypoxic conditions was also decreased when cells were exposed to polybrene, though overall proliferation rates were higher. The negative influence of polybrene was, however, reduced when the cells were exposed to polybrene for a shorter period of time (6 hr vs 24 hr. Thus, careful evaluation should be done when using polybrene to aid in lentiviral transduction of human MSCs or other primary cells, especially when cell number is critical.

[New strategy for RNA vectorization in mammalian cells. Use of a peptide vector].

Science.gov (United States)

Vidal, P; Morris, M C; Chaloin, L; Heitz, F; Divita, G

1997-04-01

A major barrier for gene delivery is the low permeability of nucleic acids to cellular membranes. The development of antisenses and gene therapy has focused mainly on improving methods of oligonucleotide or gene delivery to the cell. In this report we described a new strategy for RNA cell delivery, based on a short single peptide. This peptide vector is derived from both the fusion domain of the gp41 protein of HIV and the nuclear localization sequence of the SV40 large T antigen. This peptide vector localizes rapidly to the cytoplasm then to the nucleus of human fibroblasts (HS-68) within a few minutes and exhibits a high affinity for a single-stranded mRNA encoding the p66 subunit of the HIV-1 reverse transcriptase (in a 100 nM range). The peptide/RNA complex formation involves mainly electrostatic interactions between the basic residues of the peptide and the charges on the phosphate group of the RNA. In the presence of the peptide-vector fluorescently-labelled mRNA is delivered into the cytoplasm of mammalian cells (HS68 human fibroblasts) in less than 1 h with a relatively high efficiency (80%). This new concept based on a peptide-derived vector offers several advantages compared to other compounds commonly used in gene delivery. This vector is highly soluble and exhibits no cytotoxicity at the concentrations used for optimal gene delivery. This result clearly supports the fact that this peptide vector is a powerful tool and that it can be used widely, as much for laboratory research as for new applications and development in gene and/or antisense therapy.

Perinatal systemic gene delivery using adeno-associated viral vectors

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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.

Protection against California 2002 NDV strain afforded by adenovirus vectored vaccine expressing Fusion or Hemagglutination-neuraminidase genes

Science.gov (United States)

Vectored vaccines expressing the combination of the hemagglutinin-neuraminidase (HN) and fusion (F) genes generally have better clinical protection against Newcastle disease virus (NDV) than when either the F and HN genes are expressed alone. Interestingly, the protection induced by F is usually bet...

Lentviral-mediated RNAi to inhibit target gene expression of the porcine integrin αv subunit, the FMDV receptor, and against FMDV infection in PK-15 cells

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Lin Tong

2011-09-01

Full Text Available Abstract Background shRNA targeting the integrin αv subunit, which is the foot-and-mouth disease virus (FMDV receptor, plays a key role in virus attachment to susceptible cells. We constructed a RNAi lentiviral vector, iαv pLenti6/BLOCK -iT™, which expressed siRNA targeting the FMDV receptor, the porcine integrin αv subunit, on PK-15 cells. We also produced a lentiviral stock, established an iαv-PK-15 cell line, evaluated the gene silencing efficiency of mRNA using real-time qRT-PCR, integrand αv expression by indirect immunofluorescence assay (IIF and cell enzyme linked immunosorbent assays (cell ELISA, and investigated the in vivo inhibitory effect of shRNA on FMDV replication in PK-15 cells. Results Our results indicated successful establishment of the iαv U6 RNAi entry vector and the iαv pLenti6/BLOCK -iT expression vector. The functional titer of obtained virus was 1.0 × 106 TU/mL. To compare with the control and mock group, the iαv-PK-15 group αv mRNA expression rate in group was reduced by 89.5%, whilst IIF and cell ELISA clearly indicated suppression in the experimental group. Thus, iαv-PK-15 cells could reduce virus growth by more than three-fold and there was a > 99% reduction in virus titer when cells were challenged with 102 TCID50 of FMDV. Conclusions Iαv-PK-15 cells were demonstrated as a cell model for anti-FMDV potency testing, and this study suggests that shRNA could be a viable therapeutic approach for controlling the severity of FMD infection and spread.

A PCR-Based Method to Construct Lentiviral Vector Expressing Double Tough Decoy for miRNA Inhibition.

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Huiling Qiu

Full Text Available DNA vector-encoded Tough Decoy (TuD miRNA inhibitor is attracting increased attention due to its high efficiency in miRNA suppression. The current methods used to construct TuD vectors are based on synthesizing long oligonucleotides (~90 mer, which have been costly and problematic because of mutations during synthesis. In this study, we report a PCR-based method for the generation of double Tough Decoy (dTuD vector in which only two sets of shorter oligonucleotides (< 60 mer were used. Different approaches were employed to test the inhibitory potency of dTuDs. We demonstrated that dTuD is the most efficient method in miRNA inhibition in vitro and in vivo. Using this method, a mini dTuD library against 88 human miRNAs was constructed and used for a high-throughput screening (HTS of AP-1 pathway-related miRNAs. Seven miRNAs (miR-18b-5p, -101-3p, -148b-3p, -130b-3p, -186-3p, -187-3p and -1324 were identified as candidates involved in AP-1 pathway regulation. This novel method allows for an accurate and cost-effective generation of dTuD miRNA inhibitor, providing a powerful tool for efficient miRNA suppression in vitro and in vivo.

Tissue-specific expression of silkmoth chorion genes in vivo using Bombyx mori nuclear polyhedrosis virus as a transducing vector.

Science.gov (United States)

Iatrou, K; Meidinger, R G

1990-01-01

A pair of silkmoth chorion chromosomal genes, HcA.12-HcB.12, was inserted into a baculovirus transfer vector, pBmp2, derived from the nuclear polyhedrosis virus of Bombyx mori. This vector, which permits the insertion of foreign genetic material in the vicinity of a mutationally inactivated polyhedrin gene, was used to acquire the corresponding recombinant virus. Injection of mutant silkmoth pupae that lack all Hc chorion genes with the recombinant virus resulted in the infection of all internal organs including follicular tissue. Analysis of RNA from infected tissues has demonstrated that the two chorion genes present in the viral genome are correctly transcribed under the control of their own promoter in follicular cells, the tissue in which chorion genes are normally expressed. The chorion primary transcripts are also correctly processed in the infected follicular cells and yield mature mRNAs indistinguishable from authentic chorion mRNAs present in wild-type follicles. These results demonstrate that recombinant nuclear polyhedrosis viruses can be used as transducing vectors for introducing genetic material of host origin into the cells of the organism and that the transduced genes are transiently expressed in a tissue-specific manner under the control of their resident regulatory sequences. Thus we show the in vivo expression of cloned genes under cellular promoter control in an insect other than Drosophila melanogaster. The approach should be applicable to all insect systems that are subject to nuclear polyhedrosis virus infection. Images PMID:2187186

Apple latent spherical virus vectors for reliable and effective virus-induced gene silencing among a broad range of plants including tobacco, tomato, Arabidopsis thaliana, cucurbits, and legumes

International Nuclear Information System (INIS)

Igarashi, Aki; Yamagata, Kousuke; Sugai, Tomokazu; Takahashi, Yukari; Sugawara, Emiko; Tamura, Akihiro; Yaegashi, Hajime; Yamagishi, Noriko; Takahashi, Tsubasa; Isogai, Masamichi; Takahashi, Hideki; Yoshikawa, Nobuyuki

2009-01-01

Apple latent spherical virus (ALSV) vectors were evaluated for virus-induced gene silencing (VIGS) of endogenous genes among a broad range of plant species. ALSV vectors carrying partial sequences of a subunit of magnesium chelatase (SU) and phytoene desaturase (PDS) genes induced highly uniform knockout phenotypes typical of SU and PDS inhibition on model plants such as tobacco and Arabidopsis thaliana, and economically important crops such as tomato, legume, and cucurbit species. The silencing phenotypes persisted throughout plant growth in these plants. In addition, ALSV vectors could be successfully used to silence a meristem gene, proliferating cell nuclear antigen and disease resistant N gene in tobacco and RCY1 gene in A. thaliana. As ALSV infects most host plants symptomlessly and effectively induces stable VIGS for long periods, the ALSV vector is a valuable tool to determine the functions of interested genes among a broad range of plant species.

The feasibility of using a baculovirus vector to deliver the sodium-iodide symporter gene as a reporter

Energy Technology Data Exchange (ETDEWEB)

Zhou Xiang; Li Biao; Wang Jun; Yin Hongyan [Department of Nuclear Medicine, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025 (China); Zhang Yifan [Department of Nuclear Medicine, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025 (China)], E-mail: zhangyifan1992@yahoo.com.cn

2010-04-15

Purpose: To evaluate the efficiency of baculovirus vectors in transducing FTC-133 cells and to examine the feasibility of using baculovirus vectors for the delivery of the sodium-iodide symporter (NIS) gene as a reporter through co-transduction to monitor the expression of the target gene. Method: Two recombinant baculoviruses were constructed to express NIS and green fluorescent protein (GFP) respectively. FTC-133, 8050C, SW1116, A549 cells, were infected with Bac-GFP. The infection efficiency of Bac-GFP and the intensity of fluorescence, in either the presence or absence of sodium butyrate, were monitored by flow cytometry. The iodine uptake by FTC-133 cells infected with Bac-NIS was measured using a {gamma} counter. FTC-133 cells were infected with a mixture of equal amounts of Bac-NIS and Bac-GFP at different setting of multiplicity of infection (MOI). The changes of GFP fluorescence intensity and iodine uptake were monitored 24 h after infection in the coinfected cells. Results: We have successfully constructed recombinant baculoviruses carrying NIS and GFP under the control of the cytomegalovirus IE-1 promoter. We found that transduced efficiency of baculovirus in 8505C, SW1116, A549 cells are low in absence of sodium butyrate. Yet Bac-GFP infects FTC-133 cells at a high efficiency, 77.67%, 85.57% and 93.23% with MOI of 100, 200 and 400, respectively. The fluorescence intensity of the Bac-GFP infected tumor cells correlated positively with the MOI of the virus. Sodium butyrate induction increased both the infection efficiency and the fluorescence intensity, but increase of infection efficiency was insignificant in FTC-133 cells. Reporter gene (GFP) expression in FTC-133 is stable within 7 days after infection. The radioactivity incorporated by the tumor cells infected with Bac-NIS correlated positively with the MOI of Bac-NIS as well. In tumor cells co-infected with Bac-NIS and Bac-GFP, the amount of radioactivity incorporated significantly correlated with

Construction of Double Right-Border Binary Vector Carrying Non-Host Gene Rxol Resistant to Bacterial Leaf Streak of Rice

Institute of Scientific and Technical Information of China (English)

Xu Mei-rong; XIA Zhi-hui; ZHAI Wen-xue; XU Jian-long; ZHOU Yong-li; LI Zhi-kang

2008-01-01

Rxol cloned from maize is a non-host gene resistant to bacterial leaf streak of rice. pCAMBIA1305-1 with Rxol was digested with Sca Ⅰ and NgoM Ⅳ and the double right-border binary vector pMNDRBBin6 was digested with Hpa Ⅰ and Xma Ⅰ.pMNDRBBin6 carrying the gene Rxol was acquired by ligation of blunt-end and cohesive end. The results of PCR, restriction enzyme analysis and sequencing indicated that the Rxol gene had been cloned into pMNDRBBin6. This double right-border binary vector,named as pMNDRBBin6-Rxol, will play a role in breeding marker-free plants resistant to bacterial leaf streak of rice by genetic transformation.

A novel system for simultaneous or sequential integration of multiple gene-loading vectors into a defined site of a human artificial chromosome.

Science.gov (United States)

Suzuki, Teruhiko; Kazuki, Yasuhiro; Oshimura, Mitsuo; Hara, Takahiko

2014-01-01

Human artificial chromosomes (HACs) are gene-delivery vectors suitable for introducing large DNA fragments into mammalian cells. Although a HAC theoretically incorporates multiple gene expression cassettes of unlimited DNA size, its application has been limited because the conventional gene-loading system accepts only one gene-loading vector (GLV) into a HAC. We report a novel method for the simultaneous or sequential integration of multiple GLVs into a HAC vector (designated as the SIM system) via combined usage of Cre, FLP, Bxb1, and φC31 recombinase/integrase. As a proof of principle, we first attempted simultaneous integration of three GLVs encoding EGFP, Venus, and TdTomato into a gene-loading site of a HAC in CHO cells. These cells successfully expressed all three fluorescent proteins. Furthermore, microcell-mediated transfer of HACs enabled the expression of those fluorescent proteins in recipient cells. We next demonstrated that GLVs could be introduced into a HAC one-by-one via reciprocal usage of recombinase/integrase. Lastly, we introduced a fourth GLV into a HAC after simultaneous integration of three GLVs by FLP-mediated DNA recombination. The SIM system expands the applicability of HAC vectors and is useful for various biomedical studies, including cell reprogramming.

A novel system for simultaneous or sequential integration of multiple gene-loading vectors into a defined site of a human artificial chromosome.

Directory of Open Access Journals (Sweden)

Teruhiko Suzuki

Full Text Available Human artificial chromosomes (HACs are gene-delivery vectors suitable for introducing large DNA fragments into mammalian cells. Although a HAC theoretically incorporates multiple gene expression cassettes of unlimited DNA size, its application has been limited because the conventional gene-loading system accepts only one gene-loading vector (GLV into a HAC. We report a novel method for the simultaneous or sequential integration of multiple GLVs into a HAC vector (designated as the SIM system via combined usage of Cre, FLP, Bxb1, and φC31 recombinase/integrase. As a proof of principle, we first attempted simultaneous integration of three GLVs encoding EGFP, Venus, and TdTomato into a gene-loading site of a HAC in CHO cells. These cells successfully expressed all three fluorescent proteins. Furthermore, microcell-mediated transfer of HACs enabled the expression of those fluorescent proteins in recipient cells. We next demonstrated that GLVs could be introduced into a HAC one-by-one via reciprocal usage of recombinase/integrase. Lastly, we introduced a fourth GLV into a HAC after simultaneous integration of three GLVs by FLP-mediated DNA recombination. The SIM system expands the applicability of HAC vectors and is useful for various biomedical studies, including cell reprogramming.

A compact dual promoter adeno-associated viral vector for efficient delivery of two genes to dorsal root ganglion neurons

NARCIS (Netherlands)

Fagoe, N D; Eggers, R; Verhaagen, J; Mason, M R J

Adeno-associated viral (AAV) vectors based on serotype 5 are an efficient means to target dorsal root ganglia (DRG) to study gene function in the primary sensory neurons of the peripheral nervous system. In this study, we have developed a compact AAV dual promoter vector composed of the

Expression profile of genes during resistance reversal in a temephos selected strain of the dengue vector, Aedes aegypti.

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Clare Strode

Full Text Available BACKGROUND: The mosquito Aedes aegypti is one of the most important disease vectors because it transmits two major arboviruses, dengue and yellow fever, which cause significant global morbidity and mortality. Chemical insecticides form the cornerstone of vector control. The organophosphate temephos a larvicide recommended by WHO for controlling Ae. aegypti, however, resistance to this compound has been reported in many countries, including Brazil. METHODOLOGY/PRINCIPAL FINDINGS: The aim of this study was to identify genes implicated in metabolic resistance in an Ae. aegypti temephos resistant strain, named RecR, through microarray analysis. We utilized a custom 'Ae. aegypti detox chip' and validated microarray data through RT-PCR comparing susceptible and resistant individuals. In addition, we analyzed gene expression in 4(th instar larvae from a reversed susceptible strain (RecRev, exposed and unexposed to temephos. The results obtained revealed a set of 13 and 6 genes significantly over expressed in resistant adult mosquitoes and larvae, respectively. One of these genes, the cytochrome P450 CYP6N12, was up-regulated in both stages. RT-PCR confirmed the microarray results and, additionally, showed no difference in gene expression between temephos exposed and unexposed RecRev mosquitoes. This suggested that the differences in the transcript profiles among the strains are heritable due to a selection process and are not caused by immediate insecticide exposure. Reversal of temephos resistance was demonstrated and, importantly, there was a positive correlation between a decrease in the resistance ratio and an accompanying decrease in the expression levels of previously over expressed genes. Some of the genes identified here have also been implicated in metabolic resistance in other mosquito species and insecticide resistant populations of Ae. aegypti. CONCLUSIONS/SIGNIFICANCE: The identification of gene expression signatures associated to

Synthetic biology and occupational risk.

Science.gov (United States)

Howard, John; Murashov, Vladimir; Schulte, Paul

2017-03-01

Synthetic biology is an emerging interdisciplinary field of biotechnology that involves applying the principles of engineering and chemical design to biological systems. Biosafety professionals have done an excellent job in addressing research laboratory safety as synthetic biology and gene editing have emerged from the larger field of biotechnology. Despite these efforts, risks posed by synthetic biology are of increasing concern as research procedures scale up to industrial processes in the larger bioeconomy. A greater number and variety of workers will be exposed to commercial synthetic biology risks in the future, including risks to a variety of workers from the use of lentiviral vectors as gene transfer devices. There is a need to review and enhance current protection measures in the field of synthetic biology, whether in experimental laboratories where new advances are being researched, in health care settings where treatments using viral vectors as gene delivery systems are increasingly being used, or in the industrial bioeconomy. Enhanced worker protection measures should include increased injury and illness surveillance of the synthetic biology workforce; proactive risk assessment and management of synthetic biology products; research on the relative effectiveness of extrinsic and intrinsic biocontainment methods; specific safety guidance for synthetic biology industrial processes; determination of appropriate medical mitigation measures for lentiviral vector exposure incidents; and greater awareness and involvement in synthetic biology safety by the general occupational safety and health community as well as by government occupational safety and health research and regulatory agencies.

Chitosan-Graft-Polyethylenimine/DNA Nanoparticles as Novel Non-Viral Gene Delivery Vectors Targeting Osteoarthritis

Science.gov (United States)

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. PMID:24392152

Polydnaviruses of Parasitic Wasps: Domestication of Viruses To Act as Gene Delivery Vectors

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Michael R. Strand

2012-01-01

Full Text Available Symbiosis is a common phenomenon in which associated organisms can cooperate in ways that increase their ability to survive, reproduce, or utilize hostile environments. Here, we discuss polydnavirus symbionts of parasitic wasps. These viruses are novel in two ways: (1 they have become non-autonomous domesticated entities that cannot replicate outside of wasps; and (2 they function as a delivery vector of genes that ensure successful parasitism of host insects that wasps parasitize. In this review we discuss how these novelties may have arisen, which genes are potentially involved, and what the consequences have been for genome evolution.

Lentiviral transgenesis in mice via a simple method of viral concentration.

Science.gov (United States)

Cheng, Pei-Hsun; Chang, Yu-Fan; Mao, Su-Han; Lin, Hsiu-Lien; Chen, Chuan-Mu; Yang, Shang-Hsun

2016-10-01

Transgenic animals are important in vivo models for biological research. However, low transgenic rates are commonly reported in the literature. Lentiviral transgenesis is a promising method that has greater efficiency with regard to generating transgenic animals, although the transgenic rate of this approach is highly dependent on different transgenes and concentrated lentiviruses. In this study, we modified a method to concentrate lentiviruses using a table centrifuge, commonly available in most laboratories, and carried out analysis of the transgenic efficiency in mice. Based on 26 individual constructs and 627 live pups, we found that the overall transgenic rate was more than 30%, which is higher than obtained with pronuclear microinjection. In addition, we did not find any significant differences in transgenic efficiency when the size of inserts was less than 5000 bp. These results not only show that our modified method can successfully generate transgenic mice but also suggest that this approach could be generally applied to different constructs when the size of inserts is less than 5000 bp. It is anticipated that the results of this study can help encourage the wider laboratory use of lentiviral transgenesis in mice. Copyright © 2016 Elsevier Inc. All rights reserved.

Efficient four fragment cloning for the construction of vectors for targeted gene replacement in filamentous fungi

DEFF Research Database (Denmark)

Frandsen, Rasmus John Normand; Andersson, Jens A.; Kristensen, Matilde Bylov

2008-01-01

Background: The rapid increase in whole genome fungal sequence information allows large scale functional analyses of target genes. Efficient transformation methods to obtain site-directed gene replacement, targeted over-expression by promoter replacement, in-frame epitope tagging or fusion...... of coding sequences with fluorescent markers such as GFP are essential for this process. Construction of vectors for these experiments depends on the directional cloning of two homologous recombination sequences on each side of a selection marker gene. Results: Here, we present a USER Friendly cloning based...

Advances in Viral Vector-Based TRAIL Gene Therapy for Cancer

International Nuclear Information System (INIS)

Norian, Lyse A.; James, Britnie R.; Griffith, Thomas S.

2011-01-01

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

High Level of Perforin Expression Is Required for Effective Correction of Hemophagocytic Lymphohistiocytosis

OpenAIRE

Tiwari, Swati; Hontz, Adrianne; Terrell, Catherine E.; Arumugam, Paritha; Carmo, Marlene; Risma, Kimberly; Jordan, Michael; Malik, Punam

2016-01-01

Perforin-1 mutations result in a potentially fatal hemophagocytic lymphohistiocytosis (HLH) with heightened immune activation, hypercytokinemia, pancytopenia, and end-organ damage. At present, hematopoietic stem cell (HSC) transplantation is curative, but limited by donor availability and associated mortality, making gene therapy an attractive alternative approach for HLH. We reported that perforin expression driven by cellular promoters in lentiviral (LV) vectors resulted in significant, alb...

Circumventing antivector immunity: potential use of nonhuman adenoviral vectors.

Science.gov (United States)

Lopez-Gordo, Estrella; Podgorski, Iva I; Downes, Nicholas; Alemany, Ramon

2014-04-01

Adenoviruses are efficient gene delivery vectors based on their ability to transduce a wide variety of cell types and drive high-level transient transgene expression. While there have been advances in modifying human adenoviral (HAdV) vectors to increase their safety profile, there are still pitfalls that need to be further addressed. Preexisting humoral and cellular immunity against common HAdV serotypes limits the efficacy of gene transfer and duration of transgene expression. As an alternative, nonhuman AdV (NHAdV) vectors can circumvent neutralizing antibodies against HAdVs in immunized mice and monkeys and in human sera, suggesting that NHAdV vectors could circumvent preexisting humoral immunity against HAdVs in a clinical setting. Consequently, there has been an increased interest in developing NHAdV vectors for gene delivery in humans. In this review, we outline the recent advances and limitations of HAdV vectors for gene therapy and describe examples of NHAdV vectors focusing on their immunogenicity, tropism, and potential as effective gene therapy vehicles.

Construction and characterization in vitro of a bicistronic retroviral vector coding endostatin and interleukin-2 for use in gene therapy

International Nuclear Information System (INIS)

Calvo, Fernanda Bernardes

2009-01-01

Gene therapy has been used in preclinical studies and clinical trials in order to alleviate or cure a disease. Retroviral vectors are a tool for gene transfer is widely used. Bicistronic vectors are an attractive alternative for treatment of complex diseases. A variety of options exists to simultaneously express two genes in genetically modified cells. The most common approach relies on bicistronic vectors in which the genes are linked to each other by an internal ribosome entry site allowing co-translational expression of both cistrons. Endostatin, the C-terminal fragment of collagen XVIII, is a potent angiogenesis inhibitor. At present, ES has been widely used in anti-angiogenic in a variety of experimental tumor models, and clinical trials to test it as an anti-tumor agent are already under way. Immunotherapy has been used as adjuvant treatment for tumors and has been used in several preclinical studies and clinical trials. The objective of this project was to construct and characterize 'in vitro' an IRES-based bicistronic retroviral vector encoding endostatin and interleukin-2. The construction of the vector was performed in three stages, the final construction was analyzed by restriction analysis and sequencing. Packaging cells were prepared. The endostatin and interleukin-2 levels were determined by Dot blot. Monocistronic and bicistronic mRNA expression were analyzed by real time RT-PCR. Bicistronic vector showed high levels of virus trites, ranging from 4.20x10 5 to 1.53x10 6 UFC/ml. Secreted levels of endostatin and interleukin-2 ranged from 1.08 to 2.08μg/10 6 cells.24h and 0.66 - 0.89μg/10 6 cells.24h, respectively. The mRNA expression of ES in the NIH3T3 clone pLend-IRES-IL2SN was 2 times higher than the level presented by the NIH3T3 clone pLendSN. The endostatin promoted inhibition (40%) of endothelial cell proliferation. Interleukin-2 promoted a proliferation of 10.6% lymphocytes CD4 and 8.9% of CD8. We conclude that the IRES bicistronic vector

Three-dimensional tumor spheroids for in vitro analysis of bacteria as gene delivery vectors in tumor therapy.

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Osswald, Annika; Sun, Zhongke; Grimm, Verena; Ampem, Grace; Riegel, Karin; Westendorf, Astrid M; Sommergruber, Wolfgang; Otte, Kerstin; Dürre, Peter; Riedel, Christian U

2015-12-12

Several studies in animal models demonstrated that obligate and facultative anaerobic bacteria of the genera Bifidobacterium, Salmonella, or Clostridium specifically colonize solid tumors. Consequently, these and other bacteria are discussed as live vectors to deliver therapeutic genes to inhibit tumor growth. Therapeutic approaches for cancer treatment using anaerobic bacteria have been investigated in different mouse models. In the present study, solid three-dimensional (3D) multicellular tumor spheroids (MCTS) of the colorectal adenocarcinoma cell line HT-29 were generated and tested for their potential to study prodrug-converting enzyme therapies using bacterial vectors in vitro. HT-29 MCTS resembled solid tumors displaying all relevant features with an outer zone of proliferating cells and hypoxic and apoptotic regions in the core. Upon incubation with HT-29 MCTS, Bifidobacterium bifidum S17 and Salmonella typhimurium YB1 selectively localized, survived and replicated in hypoxic areas inside MCTS. Furthermore, spores of the obligate anaerobe Clostridium sporogenes germinated in these hypoxic areas. To further evaluate the potential of MCTS to investigate therapeutic approaches using bacteria as gene delivery vectors, recombinant bifidobacteria expressing prodrug-converting enzymes were used. Expression of a secreted cytosine deaminase in combination with 5-fluorocytosine had no effect on growth of MCTS due to an intrinsic resistance of HT-29 cells to 5-fluorouracil, i.e. the converted drug. However, a combination of the prodrug CB1954 and a strain expressing a secreted chromate reductase effectively inhibited MCTS growth. Collectively, the presented results indicate that MCTS are a suitable and reliable model to investigate live bacteria as gene delivery vectors for cancer therapy in vitro.

Gateway binary vectors with the bialaphos resistance gene, bar, as a selection marker for plant transformation.

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Nakamura, Shinya; Mano, Shoji; Tanaka, Yuji; Ohnishi, Masato; Nakamori, Chihiro; Araki, Masami; Niwa, Tomoko; Nishimura, Mikio; Kaminaka, Hironori; Nakagawa, Tsuyoshi; Sato, Yutaka; Ishiguro, Sumie

2010-01-01

We constructed two series of Gateway binary vectors, pGWBs and R4pGWBs, possessing the bialaphos resistance gene (bar) as a selection marker for plant transformation. The reporters and tags employed in this system are sGFP, GUS, LUC, EYFP, ECFP, G3GFP, mRFP, TagRFP, 6xHis, FLAG, 3xHA, 4xMyc, 10xMyc, GST, T7 and TAP. Selection of Arabidopsis transformants with BASTA was successfully carried out using both plate-grown and soil-grown seedlings. Transformed rice calli and suspension-cultured tobacco cells were selected on plates containing BASTA or glufosinate-ammonium. These vectors are compatible with existing pGWB and R4pGWB vectors carrying kanamycin and hygromycin B resistance.

Analysis of the role of homology arms in gene-targeting vectors in human cells.

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Ayako Ishii

Full Text Available Random integration of targeting vectors into the genome is the primary obstacle in human somatic cell gene targeting. Non-homologous end-joining (NHEJ, a major pathway for repairing DNA double-strand breaks, is thought to be responsible for most random integration events; however, absence of DNA ligase IV (LIG4, the critical NHEJ ligase, does not significantly reduce random integration frequency of targeting vector in human cells, indicating robust integration events occurring via a LIG4-independent mechanism. To gain insights into the mechanism and robustness of LIG4-independent random integration, we employed various types of targeting vectors to examine their integration frequencies in LIG4-proficient and deficient human cell lines. We find that the integration frequency of targeting vector correlates well with the length of homology arms and with the amount of repetitive DNA sequences, especially SINEs, present in the arms. This correlation was prominent in LIG4-deficient cells, but was also seen in LIG4-proficient cells, thus providing evidence that LIG4-independent random integration occurs frequently even when NHEJ is functionally normal. Our results collectively suggest that random integration frequency of conventional targeting vectors is substantially influenced by homology arms, which typically harbor repetitive DNA sequences that serve to facilitate LIG4-independent random integration in human cells, regardless of the presence or absence of functional NHEJ.

RNA-seq analyses of blood-induced changes in gene expression in the mosquito vector species, Aedes aegypti

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Olson Ken E

2011-01-01

Full Text Available Abstract Background Hematophagy is a common trait of insect vectors of disease. Extensive genome-wide transcriptional changes occur in mosquitoes after blood meals, and these are related to digestive and reproductive processes, among others. Studies of these changes are expected to reveal molecular targets for novel vector control and pathogen transmission-blocking strategies. The mosquito Aedes aegypti (Diptera, Culicidae, a vector of Dengue viruses, Yellow Fever Virus (YFV and Chikungunya virus (CV, is the subject of this study to look at genome-wide changes in gene expression following a blood meal. Results Transcriptional changes that follow a blood meal in Ae. aegypti females were explored using RNA-seq technology. Over 30% of more than 18,000 investigated transcripts accumulate differentially in mosquitoes at five hours after a blood meal when compared to those fed only on sugar. Forty transcripts accumulate only in blood-fed mosquitoes. The list of regulated transcripts correlates with an enhancement of digestive activity and a suppression of environmental stimuli perception and innate immunity. The alignment of more than 65 million high-quality short reads to the Ae. aegypti reference genome permitted the refinement of the current annotation of transcript boundaries, as well as the discovery of novel transcripts, exons and splicing variants. Cis-regulatory elements (CRE and cis-regulatory modules (CRM enriched significantly at the 5'end flanking sequences of blood meal-regulated genes were identified. Conclusions This study provides the first global view of the changes in transcript accumulation elicited by a blood meal in Ae. aegypti females. This information permitted the identification of classes of potentially co-regulated genes and a description of biochemical and physiological events that occur immediately after blood feeding. The data presented here serve as a basis for novel vector control and pathogen transmission

Construction and expression of secreting type human TRAIL gene vector mediated by hypoxia/radiation double sensitive promoter

International Nuclear Information System (INIS)

Yang Yanming; Jia Xiaojing; Qu Yaqin; Li Yanbo

2009-01-01

Objective: To construct secreting type human TRAIL (shTRAIL) gene vector pcDNA3.1-HRE/Egr1-shTRAIL mediated by hypoxia/radiation double sensitive promoter, and observe the effect of hypoxia and radiation on shTRAIL. Methods: HRE upper and lower strands were gotten by chemical synthesis, double strands HRE was gotten by PCR; pMD19T-Egr1 was digested by Sac I and Hind III, then Egr1 was obtained, pshuttle-shTRAIL was digested by Kpn I and BamH I, then shTRAIL was obtained; HRE/Egr1 double sensitive promoter mediated shTRAIL expression vector pcDNA3.1-HRE/Egr1-shTRAIL was constructed by gene recombination technique, it was identified correctly by enzyme digestion, PCR and sequencing. A549 cells were divided into normal, hypoxia (0.1%), irradiation (6 Gy) and hypoxia + irradiation groups. Results: After enzyme digestion by BamH I and Sma I, the fragments which lengths were 1284 bp and 4 998 bp, 2 292 bp and 3 990 bp were obtained; the vector was amplified by PCR with Egr1 and shTRAIL primer, the products which lengthens were 469 bp and 820 bp were obtained; pcDNA3.1-HRE/Egr1-shTRAIL was sequenced, the result was same to designed, this demonstrated that the construction was right. The vectors were transfected into A549 cells of adenocarcinoma of lung, the expression levels of shTRAIL mRNA and protein were increased after treated with hypoxia and radiation, it had statistically significant differences compared with normal group (P<0.05), and when they were combinated, the effect was more obvious. Conclusion: Secreting type human TRAIL gene vector pcDNA3.1-HRE/Egr1-shTRAIL mediated by hypoxia/radiation double sensitive promoter is constructed successfully, and hypoxia and radiation could increase the expression of TRAIL, and they have synergetic effect. (authors)

Feline Immunodeficiency Virus Cross-Species Transmission: Implications for Emergence of New Lentiviral Infections.

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Lee, Justin; Malmberg, Jennifer L; Wood, Britta A; Hladky, Sahaja; Troyer, Ryan; Roelke, Melody; Cunningham, Mark; McBride, Roy; Vickers, Winston; Boyce, Walter; Boydston, Erin; Serieys, Laurel; Riley, Seth; Crooks, Kevin; VandeWoude, Sue

2017-03-01

Owing to a complex history of host-parasite coevolution, lentiviruses exhibit a high degree of species specificity. Given the well-documented viral archeology of human immunodeficiency virus (HIV) emergence following human exposures to simian immunodeficiency virus (SIV), an understanding of processes that promote successful cross-species lentiviral transmissions is highly relevant. We previously reported natural cross-species transmission of a subtype of feline immunodeficiency virus, puma lentivirus A (PLVA), between bobcats ( Lynx rufus ) and mountain lions ( Puma concolor ) for a small number of animals in California and Florida. In this study, we investigate host-specific selection pressures, within-host viral fitness, and inter- versus intraspecies transmission patterns among a larger collection of PLV isolates from free-ranging bobcats and mountain lions. Analyses of proviral and viral RNA levels demonstrate that PLVA fitness is severely restricted in mountain lions compared to that in bobcats. We document evidence of diversifying selection in three of six PLVA genomes from mountain lions, but we did not detect selection among 20 PLVA isolates from bobcats. These findings support the hypothesis that PLVA is a bobcat-adapted virus which is less fit in mountain lions and under intense selection pressure in the novel host. Ancestral reconstruction of transmission events reveals that intraspecific PLVA transmission has occurred among panthers ( Puma concolor coryi ) in Florida following the initial cross-species infection from bobcats. In contrast, interspecific transmission from bobcats to mountain lions predominates in California. These findings document outcomes of cross-species lentiviral transmission events among felids that compare to the emergence of HIV from nonhuman primates. IMPORTANCE Cross-species transmission episodes can be singular, dead-end events or can result in viral replication and spread in the new species. The factors that determine which

Enhanced p53 gene transfer to human ovarian cancer cells using the cationic nonviral vector, DDC.

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Kim, Chong-Kook; Choi, Eun-Jeong; Choi, Sung-Hee; Park, Jeong-Sook; Haider, Khawaja Hasnain; Ahn, Woong Shick

2003-08-01

Previously we have formulated a new cationic liposome, DDC, composed of dioleoyltrimethylamino propane (DOTAP), 1,2-dioeoyl-3-phosphophatidylethanolamine (DOPE), and cholesterol (Chol), and it efficiently delivered plasmid DNA into ovarian cancer cells. Mutations in the p53 tumor suppressor gene are the most common molecular genetic abnormalities to be described in ovarian cancer. However, there has been so far no report of nonviral vector-mediated p53 gene deliveries in ovarian cancer. In this study, wild-type p53 DNA was transfected into the ovarian cancer cells, using the DDC as a nonviral vector and the expression and activity of p53 gene were evaluated both in vitro and in vivo. DDC liposomes were prepared by mixing DOTAP:DOPE:Chol in a 1:0.7:0.3 molar ratio using the extrusion method. Plasmid DNA (pp53-EGFP) and DDC complexes were transfected into ovarian carcinoma cells (OVCAR-3 cells) and gene expression was determined by reverse transcription-polymerase chain reaction and Western blot analysis. The cellular growth inhibition and apoptosis of DDC-mediated p53 transfection were assessed by trypan blue exclusion assay and annexin-V staining, respectively. The OVCAR-3 cells treated with DDC/pp53-EGFP complexes were inoculated into female balb/c nude mice and tumor growth was observed. The transfection of liposome-complexed p53 gene resulted in a high level of wild-type p53 mRNA and protein expressions in OVCAR-3 cells. In vitro cell growth assay showed growth inhibition of cancer cells transfected with DDC/pp53-EGFP complexes compared with the control cells. The reestablishment of wild-type p53 function in ovarian cancer cells restored the apoptotic pathway. Following the inoculation of DDC/pp53-EGFP complexes, the volumes of tumors in nude mice were significantly reduced more than 60% compared to the control group. The DDC-mediated p53 DNA delivery may have the potential for clinical application as nonviral vector-mediated ovarian cancer therapy due to its

Transient foreign gene expression in chloroplasts of cultured tobacco cells after biolistic delivery of chloroplast vectors.

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Daniell, H; Vivekananda, J; Nielsen, B L; Ye, G N; Tewari, K K; Sanford, J C

1990-01-01

Expression of chloramphenicol acetyltransferase (cat) by suitable vectors in chloroplasts of cultured tobacco cells, delivered by high-velocity microprojectiles, is reported here. Several chloroplast expression vectors containing bacterial cat genes, placed under the control of either psbA promoter region from pea (pHD series) or rbcL promoter region from maize (pAC series) have been used in this study. In addition, chloroplast expression vectors containing replicon fragments from pea, tobacco, or maize chloroplast DNA have also been tested for efficiency and duration of cat expression in chloroplasts of tobacco cells. Cultured NT1 tobacco cells collected on filter papers were bombarded with tungsten particles coated with pUC118 (negative control), 35S-CAT (nuclear expression vector), pHD312 (repliconless chloroplast expression vector), and pHD407, pACp18, and pACp19 (chloroplast expression vectors with replicon). Sonic extracts of cells bombarded with pUC118 showed no detectable cat activity in the autoradiograms. Nuclear expression of cat reached two-thirds of the maximal 48 hr after bombardment and the maximal at 72 hr. Cells bombarded with chloroplast expression vectors showed a low level of expression until 48 hr of incubation. A dramatic increase in the expression of cat was observed 24 hr after the addition of fresh medium to cultured cells in samples bombarded with pHD407; the repliconless vector pHD312 showed about 50% of this maximal activity. The expression of nuclear cat and the repliconless chloroplast vector decreased after 72 hr, but a high level of chloroplast cat expression was maintained in cells bombarded with pHD407. Organelle-specific expression of cat in appropriate compartments was checked by introducing various plasmid constructions into tobacco protoplasts by electroporation. Although the nuclear expression vector 35S-CAT showed expression of cat, no activity was observed with any chloroplast vectors.

A cryptic promoter in potato virus X vector interrupted plasmid construction

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Schultz Ronald D

2007-03-01

Full Text Available Abstract Background Potato virus X has been developed into an expression vector for plants. It is widely used to express foreign genes. In molecular manipulation, the foreign genes need to be sub-cloned into the vector. The constructed plasmid needs to be amplified. Usually, during amplification stage, the foreign genes are not expressed. However, if the foreign gene is expressed, the construction work could be interrupted. Two different viral genes were sub-cloned into the vector, but only one foreign gene was successfully sub-cloned. The other foreign gene, canine parvovirus type 2 (CPV-2 VP1 could not be sub-cloned into the vector and amplified without mutation (frame shift mutation. Results A cryptic promoter in the PVX vector was discovered with RT-PCR. The promoter activity was studied with Northern blots and Real-time RT-PCR. Conclusion It is important to recognize the homologous promoter sequences in the vector when a virus is developed as an expression vector. During the plasmid amplification stage, an unexpected expression of the CPV-2 VP1 gene (not in the target plants, but in E. coli can interrupt the downstream work.

Properties of a herpes simplex virus multiple immediate-early gene-deleted recombinant as a vaccine vector

International Nuclear Information System (INIS)

Watanabe, Daisuke; Brockman, Mark A.; Ndung'u, Thumbi; Mathews, Lydia; Lucas, William T.; Murphy, Cynthia G.; Felber, Barbara K.; Pavlakis, George N.; Deluca, Neal A.; Knipe, David M.

2007-01-01

Herpes simplex virus (HSV) recombinants induce durable immune responses in rhesus macaques and mice and have induced partial protection in rhesus macaques against mucosal challenge with virulent simian immunodeficiency virus (SIV). In this study, we evaluated the properties of a new generation HSV vaccine vector, an HSV-1 multiple immediate-early (IE) gene deletion mutant virus, d106, which contains deletions in the ICP4, ICP27, ICP22, and ICP47 genes. Because several of the HSV IE genes have been implicated in immune evasion, inactivation of the genes encoding these proteins was expected to result in enhanced immunogenicity. The d106 virus expresses few HSV gene products and shows minimal cytopathic effect in cultured cells. When d106 was inoculated into mice, viral DNA accumulated at high levels in draining lymph nodes, consistent with an ability to transduce dendritic cells and activate their maturation and movement to lymph nodes. A d106 recombinant expressing Escherichia coli β-galactosidase induced durable β-gal-specific IgG and CD8 + T cell responses in naive and HSV-immune mice. Finally, d106-based recombinants have been constructed that express simian immunodeficiency virus (SIV) gag, env, or a rev-tat-nef fusion protein for several days in cultured cells. Thus, d106 shows many of the properties desirable in a vaccine vector: limited expression of HSV gene products and cytopathogenicity, high level expression of transgenes, ability to induce durable immune responses, and an ability to transduce dendritic cells and induce their maturation and migration to lymph nodes

IGF-1 Gene Transfer to Human Synovial MSCs Promotes Their Chondrogenic Differentiation Potential without Induction of the Hypertrophic Phenotype

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Yasutoshi Ikeda

2017-01-01

Full Text Available Mesenchymal stem cell- (MSC- based therapy is a promising treatment for cartilage. However, repair tissue in general fails to regenerate an original hyaline-like tissue. In this study, we focused on increasing the expression levels for insulin-like growth factor-1 (IGF-1 to improve repair tissue quality. The IGF-1 gene was introduced into human synovial MSCs with a lentiviral vector and examined the levels of gene expression and morphological status of MSCs under chondrogenic differentiation condition using pellet cultures. The size of the pellets derived from IGF-1-MSCs were significantly larger than those of the control group. The abundance of glycosaminoglycan (GAG was also significantly higher in the IGF-1-MSC group. The histology of the IGF-1-induced pellets demonstrated similarities to hyaline cartilage without exhibiting features of a hypertrophic chondrocyte phenotype. Expression levels for the Col2A1 gene and protein were significantly higher in the IGF-1 pellets than in the control pellets, but expression levels for Col10, MMP-13, ALP, and Osterix were not higher. Thus, IGF-1 gene transfer to human synovial MSCs led to an improved chondrogenic differentiation capacity without the detectable induction of a hypertrophic or osteogenic phenotype.

Gene therapy with adeno-associated virus vector 5-human factor IX in adults with hemophilia B

DEFF Research Database (Denmark)

Miesbach, Wolfgang; Meijer, Karina; Coppens, Michiel

2018-01-01

Hemophilia B gene therapy aims to ameliorate bleeding risk and provide endogenous factor IX (FIX) activity/synthesis through a single treatment, eliminating the requirement for FIX concentrate. AMT-060 combines an adeno-associated virus-5 (AAV5) vector with a liver-specific promoter driving expre...

Reduced expression of brain-enriched microRNAs in glioblastomas permits targeted regulation of a cell death gene.

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Rebecca L Skalsky

Full Text Available Glioblastoma is a highly aggressive malignant tumor involving glial cells in the human brain. We used high-throughput sequencing to comprehensively profile the small RNAs expressed in glioblastoma and non-tumor brain tissues. MicroRNAs (miRNAs made up the large majority of small RNAs, and we identified over 400 different cellular pre-miRNAs. No known viral miRNAs were detected in any of the samples analyzed. Cluster analysis revealed several miRNAs that were significantly down-regulated in glioblastomas, including miR-128, miR-124, miR-7, miR-139, miR-95, and miR-873. Post-transcriptional editing was observed for several miRNAs, including the miR-376 family, miR-411, miR-381, and miR-379. Using the deep sequencing information, we designed a lentiviral vector expressing a cell suicide gene, the herpes simplex virus thymidine kinase (HSV-TK gene, under the regulation of a miRNA, miR-128, that was found to be enriched in non-tumor brain tissue yet down-regulated in glioblastomas, Glioblastoma cells transduced with this vector were selectively killed when cultured in the presence of ganciclovir. Using an in vitro model to recapitulate expression of brain-enriched miRNAs, we demonstrated that neuronally differentiated SH-SY5Y cells transduced with the miRNA-regulated HSV-TK vector are protected from killing by expression of endogenous miR-128. Together, these results provide an in-depth analysis of miRNA dysregulation in glioblastoma and demonstrate the potential utility of these data in the design of miRNA-regulated therapies for the treatment of brain cancers.

The Role of Skp2 in the Prostate Tumorigenesis Following Rb and p53 Loss

Science.gov (United States)

2015-12-01

Cancer center seminar, departmental weekly working in progress and journal club give me opportunities to developmental presentation skills and group...Einstein Gene therapy Core, lentivirus vectors expressing p27, p53, or shRNAs from Einstein shRNA Core facility. Lentiviral helper constructs were...inhibitors. We further show that GC B cells and T cells use different mechanisms to regulate their p27 protein levels, and propose a T helper cell

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

Stable replication of the EBNA1/OriP-mediated baculovirus vector and its application to anti-HCV gene therapy

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Chang Myint OO

2009-10-01

Full Text Available Abstract Background Hepatitis C virus (HCV is one of the main causes of liver-related morbidity and mortality. Although combined interferon-α-ribavirin therapy is effective for about 50% of the patients with HCV, better therapies are needed and preventative vaccines have yet to be developed. Short-hairpin RNAs (shRNAs inhibit gene expression by RNA interference. The application of transient shRNA expression is limited, however, due to the inability of the shRNA to replicate in mammalian cells and its inefficient transduction. The duration of transgene (shRNA expression in mammalian cells can be significantly extended using baculovirus-based shRNA-expressing vectors that contain the latent viral protein Epstein-Barr nuclear antigen 1 (EBNA1 and the origin of latent viral DNA replication (OriP sequences. These recombinant vectors contain compatible promoters and are highly effective for infecting primary hepatocyte and hepatoma cell lines, making them very useful tools for studies of hepatitis B and hepatitis C viruses. Here, we report the use of these baculovirus-based vector-derived shRNAs to inhibit core-protein expression in full-length hepatitis C virus (HCV replicon cells. Results We constructed a long-term transgene shRNA expression vector that contains the EBV EBNA1 and OriP sequences. We also designed baculovirus vector-mediated shRNAs against the highly conserved core-protein region of HCV. HCV core protein expression was inhibited by the EBNA1/OriP baculovirus vector for at least 14 days, which was considerably longer than the 3 days of inhibition produced by the wild-type baculovirus vector. Conclusion These findings indicate that we successfully constructed a long-term transgene (shRNA expression vector (Ac-EP-shRNA452 using the EBNA1/OriP system, which was propagated in Escherichia coli and converted into mammalian cells. The potential anti-HCV activity of the long-term transgene (shRNA expression vector was evaluated with the view

NYVAC vector modified by C7L viral gene insertion improves T cell immune responses and effectiveness against leishmaniasis.

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Sánchez-Sampedro, L; Mejías-Pérez, E; S Sorzano, Carlos Óscar; Nájera, J L; Esteban, M

2016-07-15

The NYVAC poxvirus vector is used as vaccine candidate for HIV and other diseases, although there is only limited experimental information on its immunogenicity and effectiveness for use against human pathogens. Here we defined the selective advantage of NYVAC vectors in a mouse model by comparing the immune responses and protection induced by vectors that express the LACK (Leishmania-activated C-kinase antigen), alone or with insertion of the viral host range gene C7L that allows the virus to replicate in human cells. Using DNA prime/virus boost protocols, we show that replication-competent NYVAC-LACK that expresses C7L (NYVAC-LACK-C7L) induced higher-magnitude polyfunctional CD8(+) and CD4(+) primary adaptive and effector memory T cell responses (IFNγ, TNFα, IL-2, CD107a) to LACK antigen than non-replicating NYVAC-LACK. Compared to NYVAC-LACK, the NYVAC-LACK-C7L-induced CD8(+) T cell population also showed higher proliferation when stimulated with LACK antigen. After a challenge by subcutaneous Leishmania major metacyclic promastigotes, NYVAC-LACK-C7L-vaccinated mouse groups showed greater protection than the NYVAC-LACK-vaccinated group. Our results indicate that the type and potency of immune responses induced by LACK-expressing NYVAC vectors is improved by insertion of the C7L gene, and that a replication-competent vector as a vaccine renders greater protection against a human pathogen than a non-replicating vector. Copyright © 2016 Elsevier B.V. All rights reserved.

Molecular Characterization of Heterologous HIV-1gp120 Gene Expression Disruption in Mycobacterium bovis BCG Host Strain: A Critical Issue for Engineering Mycobacterial Based-Vaccine Vectors

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Joseph, Joan; Fernández-Lloris, Raquel; Pezzat, Elías; Saubi, Narcís; Cardona, Pere-Joan; Mothe, Beatriz; Gatell, Josep Maria

2010-01-01

Mycobacterium bovis Bacillus Calmette-Guérin (BCG) as a live vector of recombinant bacterial vaccine is a promising system to be used. In this study, we evaluate the disrupted expression of heterologous HIV-1gp120 gene in BCG Pasteur host strain using replicative vectors pMV261 and pJH222. pJH222 carries a lysine complementing gene in BCG lysine auxotrophs. The HIV-1 gp120 gene expression was regulated by BCG hsp60 promoter (in plasmid pMV261) and Mycobacteria spp. α-antigen promoter (in plasmid pJH222). Among 14 rBCG:HIV-1gp120 (pMV261) colonies screened, 12 showed a partial deletion and two showed a complete deletion. However, deletion was not observed in all 10 rBCG:HIV-1gp120 (pJH222) colonies screened. In this study, we demonstrated that E. coli/Mycobacterial expression vectors bearing a weak promoter and lysine complementing gene in a recombinant lysine auxotroph of BCG could prevent genetic rearrangements and disruption of HIV 1gp120 gene expression, a key issue for engineering Mycobacterial based vaccine vectors. PMID:20617151

Molecular Characterization of Heterologous HIV-1gp120 Gene Expression Disruption in Mycobacterium bovis BCG Host Strain: A Critical Issue for Engineering Mycobacterial Based-Vaccine Vectors

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Joan Joseph

2010-01-01

Full Text Available Mycobacterium bovis Bacillus Calmette-Guérin (BCG as a live vector of recombinant bacterial vaccine is a promising system to be used. In this study, we evaluate the disrupted expression of heterologous HIV-1gp120 gene in BCG Pasteur host strain using replicative vectors pMV261 and pJH222. pJH222 carries a lysine complementing gene in BCG lysine auxotrophs. The HIV-1 gp120 gene expression was regulated by BCG hsp60 promoter (in plasmid pMV261 and Mycobacteria spp. α-antigen promoter (in plasmid pJH222. Among 14 rBCG:HIV-1gp120 (pMV261 colonies screened, 12 showed a partial deletion and two showed a complete deletion. However, deletion was not observed in all 10 rBCG:HIV-1gp120 (pJH222 colonies screened. In this study, we demonstrated that E. coli/Mycobacterial expression vectors bearing a weak promoter and lysine complementing gene in a recombinant lysine auxotroph of BCG could prevent genetic rearrangements and disruption of HIV 1gp120 gene expression, a key issue for engineering Mycobacterial based vaccine vectors.

Vectors for Inhaled Gene Therapy in Lung Cancer. Application for Nano Oncology and Safety of Bio Nanotechnology

Science.gov (United States)

Zarogouldis, Paul; Karamanos, Nikos K.; Porpodis, Konstantinos; Domvri, Kalliopi; Huang, Haidong; Hohenforst-Schimdt, Wolfgang; Goldberg, Eugene P.; Zarogoulidis, Konstantinos

2012-01-01

Novel aerosol therapeutic modalities have been investigated for lung cancer. Inhaled gene therapy has presented safety and effectiveness previously in cystic fibrosis. However, safety concerns have been raised regarding the safety of non-viral vectors for inhaled gene therapy in lung cancer, and therefore small steps have been made towards this multifunctional treatment modality. During the last decade, numerous new nanocomplexes have been created and investigated as a safe gene delivery nano-vehicle. These formulations are multifunctional; they can be used as either local therapy or carrier for an effective inhaled gene therapy for lung cancer. Herein, we present current and future perspectives of nanocomplexes for inhaled gene therapy treatment in lung cancer. PMID:23109824

Clonal Dominance With Retroviral Vector Insertions Near the ANGPT1 and ANGPT2 Genes in a Human Xenotransplant Mouse Model

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Reinhard Haemmerle

2014-01-01

Full Text Available Insertional leukemogenesis represents the major risk factor of hematopoietic stem cell (HSC based gene therapy utilizing integrating viral vectors. To develop a pre-clinical model for the evaluation of vector-related genotoxicity directly in the relevant human target cells, cord blood CD34+ HSCs were transplanted into immunodeficient NOD.SCID.IL2rg−/− (NSG mice after transduction with an LTR-driven gammaretroviral vector (GV. Furthermore, we specifically investigated the effect of prolonged in vitro culture in the presence of cytokines recently described to promote HSC expansion or maintenance. Clonality of human hematopoiesis in NSG mice was assessed by high throughput insertion site analyses and validated by insertion site-specific PCR depicting a GV typical integration profile with insertion sites resembling to 25% those of clinical studies. No overrepresentation of integrations in the vicinity of cancer-related genes was observed, however, several dominant clones were identified including two clones harboring integrations in the ANGPT1 and near the ANGPT2 genes associated with deregulated ANGPT1- and ANGPT2-mRNA levels. While these data underscore the potential value of the NSG model, our studies also identified short-comings such as overall low numbers of engrafted HSCs, limited in vivo observation time, and the challenges of in-depth insertion site analyses by low contribution of gene modified hematopoiesis.

An episomal vector-based CRISPR/Cas9 system for highly efficient gene knockout in human pluripotent stem cells.

Science.gov (United States)

Xie, Yifang; Wang, Daqi; Lan, Feng; Wei, Gang; Ni, Ting; Chai, Renjie; Liu, Dong; Hu, Shijun; Li, Mingqing; Li, Dajin; Wang, Hongyan; Wang, Yongming

2017-05-24

Human pluripotent stem cells (hPSCs) represent a unique opportunity for understanding the molecular mechanisms underlying complex traits and diseases. CRISPR/Cas9 is a powerful tool to introduce genetic mutations into the hPSCs for loss-of-function studies. Here, we developed an episomal vector-based CRISPR/Cas9 system, which we called epiCRISPR, for highly efficient gene knockout in hPSCs. The epiCRISPR system enables generation of up to 100% Insertion/Deletion (indel) rates. In addition, the epiCRISPR system enables efficient double-gene knockout and genomic deletion. To minimize off-target cleavage, we combined the episomal vector technology with double-nicking strategy and recent developed high fidelity Cas9. Thus the epiCRISPR system offers a highly efficient platform for genetic analysis in hPSCs.

hTERT gene immortalized human adipose-derived stem cells and its multiple differentiations: a preliminary investigation.

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Wang, L; Song, K; Qu, X; Wang, H; Zhu, H; Xu, X; Zhang, M; Tang, Y; Yang, X

2013-03-01

Human adipose-derived adult stem cells (hADSCs) can express human telomerase reverse transcriptase phenotypes under an appropriate culture condition. Because adipose tissue is abundant and easily accessible, hADSCs offer a promising source of stem cells for tissue engineering application and other cell-based therapies. However, the shortage of cells number and the difficulty to proliferate, known as the "Hayflick limit" in vitro, limit their further clinical application. Here, hADSCs were transfected with human telomerase reverse transcriptase (hTERT) gene by the lentiviral vector to prolong the lifespan of stem cells and even immortalize them. Following to this, the cellular properties and functionalities of the transfected cell lines were assayed. The results demonstrated that hADSCs had been successfully transfected with hTERT gene (hTERT-ADSCs). Then, hTERT-ADSCs were initially selected by G418 and subsequently expanded over 20 passages in vitro. Moreover, the qualitative and quantitative differentiation criteria for 20 passages of hTERT-ADSCs also demonstrated that hTERT-ADSCs could differentiate into osteogenesis, chondrogenesis, and adipogenesis phenotypes in lineage-specific differentiation media. These findings confirmed that this transfection could prolong the lifespan of hADSCs.

Dual AAV Vectors for Stargardt Disease.

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Trapani, Ivana

2018-01-01

Stargardt disease (STGD1), due to mutations in the large ABCA4 gene, is the most common inherited macular degeneration in humans. Attempts at developing gene therapy approaches for treatment of STGD1 are currently ongoing. Among all the vectors available for gene therapy of inherited retinal diseases, those based on adeno-associated viruses (AAV) are the most promising given the efficacy shown in various animal models and their excellent safety profile in humans, as confirmed in many ongoing clinical trials. However, one of the main obstacles for the use of AAV is their limited effective packaging capacity of about 5 kb. Taking advantage of the AAV genome's ability to concatemerize , others and we have recently developed dual AAV vectors to overcome this limit. We tested dual AAV vectors for ABCA4 delivery, and found that they transduce efficiently both mouse and pig photoreceptors , and rescue the Abca4-/- mouse retinal phenotype, indicating their potential for gene therapy of STGD1. This chapter details how we designed dual AAV vectors for the delivery of the ABCA4 gene and describes the techniques that can be explored to evaluate dual AAV transduction efficiency in vitro and in the retina, and their efficacy in the mouse model of STGD1.

Gene discovery for the bark beetle-vectored fungal tree pathogen Grosmannia clavigera

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Robertson Gordon

2010-10-01

Full Text Available Abstract Background Grosmannia clavigera is a bark beetle-vectored fungal pathogen of pines that causes wood discoloration and may kill trees by disrupting nutrient and water transport. Trees respond to attacks from beetles and associated fungi by releasing terpenoid and phenolic defense compounds. It is unclear which genes are important for G. clavigera's ability to overcome antifungal pine terpenoids and phenolics. Results We constructed seven cDNA libraries from eight G. clavigera isolates grown under various culture conditions, and Sanger sequenced the 5' and 3' ends of 25,000 cDNA clones, resulting in 44,288 high quality ESTs. The assembled dataset of unique transcripts (unigenes consists of 6,265 contigs and 2,459 singletons that mapped to 6,467 locations on the G. clavigera reference genome, representing ~70% of the predicted G. clavigera genes. Although only 54% of the unigenes matched characterized proteins at the NCBI database, this dataset extensively covers major metabolic pathways, cellular processes, and genes necessary for response to environmental stimuli and genetic information processing. Furthermore, we identified genes expressed in spores prior to germination, and genes involved in response to treatment with lodgepole pine phloem extract (LPPE. Conclusions We provide a comprehensively annotated EST dataset for G. clavigera that represents a rich resource for gene characterization in this and other ophiostomatoid fungi. Genes expressed in response to LPPE treatment are indicative of fungal oxidative stress response. We identified two clusters of potentially functionally related genes responsive to LPPE treatment. Furthermore, we report a simple method for identifying contig misassemblies in de novo assembled EST collections caused by gene overlap on the genome.

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

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