Cations ; Genetic Vectors ; Polymers

Somatic gene therapy based on nonviral and viral vectors is an attractive approach for treatment of human diseases. It has developed from preliminary animal experiments to clinical trials. Vectors and target genes used in gene therapy are mainly focused on viral, nonviral vector and single target gene or monogene and each vector system has a series of advantages and limitations. However, the application of gene therapy to human disease is currently hampered by potential hazards of methods of gene delivery, the relatively low efficiency and intracellular stability of target gene. Safety, efficacy and stability are three problems that people often met and also three principles that people should be followed in gene therapy.
Genetic Therapy ; adverse effects ; Genetic Vectors ; Humans

OBJECTIVETo construct a eukaryotic vector which could express bone morphogenetic protein-7 (bmp-7) in MC3T3-E1.

METHODSBone morphogenetic protein-7 gene was obtained by RT-PCR from human embryo kidney. And after sequencing and electrophoresis the obtained aim DNA fragment was inserted into eukaryotic expression plasmid pcDNA3.1 (+) by using restricted endonuclease and ligase. The DNA sequence of the newly-constructed plamids was proved right by the gene technic company. And then the new plasmids containing right sequence aim gene were transfected into MC3T3-E1 cells by Lipofectamine 2000. 72 h after transfecting, RT-PCR was performed to show the transfected cells containing the aim gene, and the whole protein of the transfected cells were gathered and used as samples in the next Western blot to test the expression of bmp-7 gene.

RESULTSDNA sequencing indicated the sequence of the obtained bmp-7 was identical to the reported ones in GeneBank. The electrophoretic map of the products of RT-PCR and restriction enzyme digestion played another evidence that the newly-constructed plasmids were bmp-7/pcDNA3.1(+). The results of Western blot showed that the transfected cells could express BMP-7.

CONCLUSIONThe construction of a eukaryotic vector which could express BMP-7 in MC3T3-E1 was successful.

OBJECTIVETo establish the expression and purification route for the gene encoding human amelongenin (AMG) mature peptide in Escherichia coli (E. coli).

METHODSRecombined plasmid pGEX-4T-1/AMG was identified by double endonuclease digestion electrophoretogram and DNA sequence analysis. The recombined plasmid was transformed to E. coli BL21. The inducing time, isopropyl-beta-D-thiogalactopyranoside (IPTG) concentration and inducing temperature were optimized for the express system. Under the optimized condition, the target fusing protein in superatant, periplasm, plasm and inclusion body was analyzed separately. A great amount of target fusing protein was found in the dissoluble protein. AMG fusing protein was purified by the GSTrapFF affinity column.

RESULTSDouble endonuclease digestion electrophoretogram and DNA sequence analysis were done to identify the recombined vector pGEX-4T-1/AMG. The results were consistent with the anticipation. The optimum inducing time was 14.5 hours. The optimum IPTG concentration was 1.0 mmol/L. The optimum inducing temperature was 20 degrees C. Under this condition, the target protein was expressed to a maximum. Plentiful target protein was expressed in plasm and inclusion body under the optimized condition. A mount of plasm protein was obtained and purified by the GSTrapFF affinity column. The purified liquid was collected and analyzed by SDS-polyacrylamide gel electrophoresis (SDS-PACE). The protein electrophoresis map showed that AMG fusing protein was purified successfully. After twice elution, high pure fusing protein was obtained.

CONCLUSIONpGEX-4T-1/AMG system is used successfully to express human AMG fusing protein.

Dependovirus ; genetics ; Genetic Therapy ; Genetic Vectors ; Humans ; Liver Diseases ; therapy

The development of the genetic transformation systems in extremely halophilic Archaea was reviewed in this paper. Included are the screening of selectable markers for resistance to antibiotics, the development of gene cloning and expression vectors, and the modifications of the host organisms.
Archaea ; genetics ; Cloning, Molecular ; Genetic Vectors ; Transformation, Genetic

Gene therapy has been considered as one of the optimal treatments. Although, at the beginning of this century, a series of unexpected side effects brought gene therapy into depression, the improved lentiviral vectors, which characterised by high efficiency transfection, stable expression in target cells and good biosafety, have been applied in clinical trials in recent years and acquired a certain clinical improvements. Nowadays gene therapy becomes an eye-catching field. This review discusses the gene therapy how blocked by lentiviral vectors, the high efficiency and biosafety of lentiviral vectors, the improvement of lentiviral vector preparation and so on.
Animals ; Genetic Therapy ; Genetic Vectors ; Humans ; Lentivirus ; genetics ; Transfection

Gene therapy is a rapidly developing field. The most widely used technique for foreign gene transfer is lentiviral-mediated gene therapy. Lentiviral vector has been developed from the first generation to the third generation in terms of safety. The preparation of lentiviruses with high titer remains difficult. In this study, a Fibra-Cel sheet carrier was used as an HEK293T cell carrier matrix, and several sterile cell culture spinners were combined and cultured on a roller bottle machine to scale up the adherent cells. The virus titer was maximized by screening the factors to optimize the lentivirus titer in the third-generation lentivirus packaging process one by one. Fibra-Cel sheet vector was successfully used as the matrix of HEK293T cell adhesion to culture adherent cells at large scale. The optimal conditions for large-scale preparation of the third-generation lentivirus by bottle roller were screened and three batches of lentiviruses were produced on pilot scale. The production time of lentivirus was shortened from 120 hours to 54 hours from plasmid transfection to virus collection; in terms of cost, a rolling bottle machine was used instead of a bioreactor, leading to lower cost and no need for repeated sterilization during the whole process. The safe, effective and low-cost operation of successful production will provide a technical base for the large-scale preparation of lentivirus and thus lay a firm foundation for its clinical application.
Genetic Vectors ; HEK293 Cells ; Humans ; Lentivirus ; Transduction, Genetic ; Transfection

Immunotherapy is becoming an effective and less invasive strategy that can be applied to the treatment of various malignancies. Lentiviral vectors (LVs) have shown great potential in immunotherapy as they can stably integrate relatively large foreign DNA, and effectively transduce dividing and non-dividing cells. Clinical application needs high quality LVs, and therefore strict quality control of the final products is necessary to ensure their purity, efficacy and safety. The quantitative detection of LVs is among the key parts of product development and quality control. In this paper, the existing methods for quantitative detection of LVs are summarized, including fluorescence activated cell sorter (FACS), P24 enzyme-linked immuno sorbent assay (P24 ELISA), real-time fluorescence quantitative polymerase chain reaction (RT-qPCR), nanoparticle tracking analysis (NTA), tunable resistive pulse sensing(TRPS) and virus counter(VC).Their advantages and disadvantages are listed, and future development and challenges are discussed.
Genetic Vectors/genetics* ; Humans ; Immunotherapy ; Lentivirus/genetics* ; Neoplasms ; Transduction, Genetic

Viruses are powerful tools for the study of modern neurosciences. Most of the research on the connection and function of neurons were done by using recombinant viruses, among which neurotropic herpesvirus is one of the most important tools. With the continuous development of genetic engineering and molecular biology techniques, several recombinant neurophilic herpesviruses have been engineered into different viral tools for neuroscience research. This review describes and discusses several common and widely used neurophilic herpesviruses as nerve conduction tracers, viral vectors for neurological diseases, and lytic viruses for neuro-oncology applications, which provides a reference for further exploring the function of neurophilic herpesviruses.
Herpesviridae/genetics* ; Neurosciences ; Genetic Vectors/genetics* ; Genetic Engineering ; Neurons