Search results for "Viral vector"
showing 10 items of 57 documents
Pharmacodynamic approach to study the gene transfer process employing non-viral vectors
2000
Abstract In the present work we set out to apply pharmacodynamic concepts derived from dose–response curves (Potency and Efficacy) to characterize the gene transfer efficiency of a vector:DNA complex. We employed two widely used vectors, the cationic lipid DOTAP (N,N,N-trimethyl 1-2-3-bis (1-oxo-9-octa-decenyl)oxy-(Z,Z)-1-propanaminium methyl sulfate) and the cationic polymer PEI (polyethylenimine, 800 kDa) to transfect several constructions of the green fluorescent protein cDNA. The analysis of dose–response curves indicated that in all cases the goodness-of-fit was > 0.99. Potency is a measure that provides information on gene activity per amount of DNA. Efficacy is a measure of maximum g…
Direct conversion of human fibroblast to hepatocytes using a single inducible polycistronic vector
2019
Abstract Background Human fibroblasts can be reprogrammed into induced hepatocyte-like cells through the expression of a set of transcription factors. Although the generation of induced hepatocyte-like cells by HNF4A, HNF1A, and FOXA3 expression has proven to be a robust experimental strategy, using multiple lentivirus results in a highly variable heterogeneous population. Methods We designed and implemented a novel approach based on the delivery of reprogramming factors and green fluorescent protein in a single doxycycline-inducible lentiviral vector using 2A self-cleaving peptides. Results Fibroblasts infected with the lentiviral vector can be amplified in basic fibroblast culture media i…
Complete tumor prevention by engineered tumor cell vaccines employing nonviral vectors.
2004
We report that 100% mice survival after tumor challenge is achieved with cytokine-engineered cells employing nonviral lipoplexes and without using viral vectors. We describe this effect with cytokine-secreting tumor cell vaccines, based on cell clones or fresh transfected cells. Tumor cells were transfected with murine granulocyte-macrophage colony-stimulating factor (GM-CSF) or IL-4 plasmids employing the cationic lipid DOTAP, were irradiated (150 Gy) and kept frozen until use. The transfection efficacy was analyzed by qRT-PCR and flow cytometry. Vaccination induced potent antitumor rejection, resulting in 100% mice survival. Furthermore, the antitumor immunity was long lasting, since a tw…
HIF-1α and Pro-Inflammatory Signaling Improves the Immunomodulatory Activity of MSC-Derived Extracellular Vesicles
2021
Despite the strong evidence for the immunomodulatory activity of mesenchymal stromal cells (MSCs), clinical trials have so far failed to clearly show benefit, likely reflecting methodological shortcomings and lack of standardization. MSC-mediated tissue repair is commonly believed to occur in a paracrine manner, and it has been stated that extracellular vesicles (EVs) secreted by MSCs (EVMSC) are able to recapitulate the immunosuppressive properties of parental cells. As a next step, clinical trials to corroborate preclinical studies should be performed. However, effective dose in large mammals, including humans, is quite high and EVs industrial production is hindered by the proliferative s…
Transmissible gastroenteritis virus (TGEV)-based vectors with engineered murine tropism express the rotavirus VP7 protein and immunize mice against r…
2011
A coronavirus vector based on the genome of the porcine transmissible gastroenteritis virus (TGEV) expressing the rotavirus VP7 protein was constructed to immunize and protect against rotavirus infections in a murine model. The tropism of this TGEV-derived vector was modified by replacing the spike S protein with the homologous protein from mouse hepatitis virus (MHV). The rotavirus gene encoding the VP7 protein was cloned into the coronavirus cDNA. BALB/c and STAT1-deficient mice were inoculated with the recombinant viral vector rTGEVS-MHV-VP7, which replicates in the intestine and spreads to other organs such as liver, spleen and lungs. TGEV-specific antibodies were detected in all the in…
Gold Nanoparticle-Assisted Virus Formation by Means of the Delivery of an Oncolytic Adenovirus Genome
2020
[EN] Oncolytic adenoviruses are a therapeutic alternative to treat cancer based on their ability to replicate selectively in tumor cells. However, their use is limited mainly by the neutralizing antibody (Nab) immune response that prevents repeated dosing. An alternative to facilitate the DNA access to the tumor even in the presence of anti-viral Nabs could be gold nanoparticles able to transfer DNA molecules. However, the ability of these nanoparticles to carry large DNA molecules, such as an oncolytic adenovirus genome, has not been studied. In this work, gold nanoparticles were functionalized with different amounts of polyethylenimine to transfer in a safe and efficient manner a large on…
Vascular Endothelial Growth Factor Gene Therapy Promotes Nerve Regeneration in a Sciatic Nerve Graft Model in Rats
2014
: Incomplete nerve regeneration after injuries to the peripheral nervous system remains a significant problem in clinical routine and raises the need for supportive strategies. In this study we examined the effect of VEGF-gene therapy on nerve recovery after an auto-graft implantation in a 2 cm sciatic nerve defect model in 18 rats, using an adenoviral vector encoding for VEGF165 (AdCMV.VEGF 165 ) for gene transduction. Functional recovery was assessed weekly by gait analyses of the rats’ hind limbs. Morphometric evaluation including histology, axon counts, motor neuron counts and corrosion casting was carried out 18 weeks post-op. VEGF-treated animals contained a higher proportion of large…
Improved Regeneration of Autologous Nerve Transplants by Means of VEGF-Gene Therapy
2009
The impact of the Vascular Endothelial Growth Factor (VEGF) on the angiogenic cascade is proven. Recently its neuroprotective effect after peripheral nerve injuries on α-motoneurons in the spinal cord was shown. Experiments on α-motoneurons demonstrated a decreased sensitivity to ischemia under VEGF-therapy. Aim of the study was to elucidate the effect of a localized VEGF-gene-therapy using an adenoviral vector construct in the model of a peripheral nerve defect in the rat treated with an autologous nerve transplant.
Nanocomplexes for gene therapy of respiratory diseases: Targeting and overcoming the mucus barrier
2015
Gene therapy, i.e. the delivery and expression of therapeutic genes, holds great promise for congenital and acquired respiratory diseases. Non-viral vectors are less toxic and immunogenic than viral vectors, although they are characterized by lower efficiency. However, they have to overcome many barriers, including inflammatory and immune mediators and cells. The respiratory and airway epithelial cells, the main target of these vectors, are coated with a layer of mucus, which hampers the effective reaching of gene therapy vectors carrying either plasmid DNA or small interfering RNA. This barrier is thicker in many lung diseases, such as cystic fibrosis. This review summarizes the most impor…
Specific Binding of Baculoviruses Displaying gp64 Fusion Proteins to Mammalian Cells
2001
Viral vectors displaying specific ligand binding moieties have raised an increasing interest in the area of targeted gene therapy. In this report, we describe baculovirus vectors displaying either a functional single chain antibody fragment (scFv) specific for the carcinoembryonic antigen (CEA) or the synthetic IgG binding domains (ZZ) derived from protein A of Staphylococcus aureus. In addition, the vectors were engineered to incorporate a reporter gene encoding the enhanced green fluorescent protein (EGFP) under the transcriptional regulation of the cytomegalovirus (CMV) IE promoter. Display of the targeting moieties on the viral surface was achieved through fusion to the N-terminus of gp…