Pigs are considered as ideal donors for xenotransplantation because they have many physiological and anatomical characteristics similar to human beings. However, antibody-mediated immunity, which includes both natural and induced antibody responses, is a major challenge for the success of pig-to-primate xenotransplantation. Various genetic modification methods help to tailor pigs to be appropriate donors for xenotransplantation. In this study, we applied transcription activator-like effector nuclease (TALEN) to knock out the porcine α-1, 3-galactosyltransferase gene GGTA1, which encodes Gal epitopes that induce hyperacute immune rejection in pig-to-human xenotransplantation. Meanwhile, human leukocyte antigen-G5 gene HLA-G5, which acts as an immunosuppressive factor, was co-transfected with TALEN into porcine fetal fibroblasts. The cell colonies of GGTA1 biallelic knockout with positive transgene for HLA-G5 were chosen as nuclear donors to generate genetic modified piglets through a single round of somatic cell nuclear transfer. As a result, we successfully obtained 20 modified piglets that were positive for GGTA1 knockout (GTKO) and half of them expressed the HLA-G5 protein. Gal epitopes on the cell membrane of GTKO/HLA-G5 piglets were completely absent. Western blotting and immunofluorescence showed that HLA-G5 was expressed in the modified piglets. Functionally, the fibroblasts from the GTKO/HLA-G5 piglets showed enhanced resistance to complement-mediated lysis ability compared with those from GTKO-only or wild-type pigs. These results indicate that the GTKO/HLA-G5 pigs could be a valuable donor model to facilitate laboratory studies and clinics for xenotransplantation.
Animals ; Animals, Genetically Modified ; Gene Knockout Techniques ; HLA Antigens ; Humans ; Nuclear Transfer Techniques ; Swine ; Transplantation, Heterologous

Animal models, particularly pigs, have come to play an important role in translational biomedical research. There have been many pig models with genetically modifications via somatic cell nuclear transfer (SCNT). However, because most transgenic pigs have been produced by random integration to date, the necessity for more exact gene-mutated models using recombinase based conditional gene expression like mice has been raised. Currently, advanced genome-editing technologies enable us to generate specific gene-deleted and -inserted pig models. In the future, the development of pig models with gene editing technologies could be a valuable resource for biomedical research.
Animals ; Gene Expression ; Gene Transfer Techniques* ; Mice ; Models, Animal ; Recombinases ; Swine

Drug development and preclinical trials are challenging processes and more than 80% to 90% of drug candidates fail to gain approval from the United States Food and Drug Administration. Predictive and efficient tools are required to discover high quality targets and increase the probability of success in the process of new drug development. One such solution to the challenges faced in the development of new drugs and combination therapies is the use of low-cost and experimentally manageable in vivo animal models. Since the 1980's, scientists have been able to genetically modify the mouse genome by removing or replacing a specific gene, which has improved the identification and validation of target genes of interest. Now genetically engineered mouse models (GEMMs) are widely used and have proved to be a powerful tool in drug discovery processes. This review particularly covers recent fascinating technologies for drug discovery and preclinical trials, targeted transgenesis and RNAi mouse, including application and combination of inducible system. Improvements in technologies and the development of new GEMMs are expected to guide future applications of these models to drug discovery and preclinical trials.
Animals ; Drug Discovery ; Gene Transfer Techniques ; Genome ; Mice* ; Models, Animal ; United States Food and Drug Administration

Gene therapy has been considered as a promising method for treatment of many diseases, such as acquired and genetic diseases. At present, there are two major vehicles for gene delivery including viral vectors and nonviral vectors. Viral vectors appear as high gene transfection efficiency, but some deficiencies such as inflammatory responses, recombination and mutagenesis have limited their use. On account of low pathogenicity, safety and cost-effectiveness, nonviral vectors have been attracted much attention. Cationic polymers are one of the nonviral vectors which have been widely studied. This review focuses on the structure of the cationic polymers and the interaction mechanism between the vector and DNA. We try to provide a framework for the future design and synthesis of nonviral vectors with high transfection efficiency and low toxicity for gene therapy.
Cations ; chemistry ; DNA ; genetics ; Gene Transfer Techniques ; Genetic Therapy ; methods ; Genetic Vectors ; genetics ; Polymers ; chemistry

Animals ; Gene Transfer Techniques ; Genetic Therapy ; methods ; Humans ; Kidney Diseases ; genetics ; therapy

OBJECTIVETo summarize the development of gene delivery vectors in peritoneal fibrosis research and discuss the feasibility and superiority of lentiviral vectors.

DATA SOURCESThe data in this article were collected from PubMed database with relevant English articles published from 1995 to 2011.

STUDY SELECTIONArticles regarding the gene therapy in peritoneal fibrosis research using non-viral vectors, adenoviral vectors, retroviral vectors, and lentiviral vectors were selected. Data were mainly extracted from 60 articles, which are listed in the reference section of this review.

RESULTSNon-viral vector-mediated gene delivery (including naked DNA for ex vivo, oligonucleotides, ultrasound- contrast agent mediated naked gene delivery, etc.) and viral vector-mediated gene delivery (including adenovirus, helper-dependant adenovirus, and retrovirus vectors) have been successfully applied both in the mechanistic investigation and the potential prevention and treatment of peritoneal fibrosis.

CONCLUSIONSPeritoneal fibrosis is a major complication of peritoneal dialysis (PD). Recently, the wide use of the gene delivery technique made it possible to access and further research peritoneal fibrosis. The use of lentiviral vector is expected to be widely used in PD research in the future due to its advantages in gene delivery.

Gene Transfer Techniques ; Genetic Engineering ; Genetic Vectors ; Humans ; Serum Albumin ; chemistry ; genetics

Currently, transgenic crops create huge economic, social and ecological benefits with the development of its commercial production. For China, the speed of development and commercialization of transgenic crops is a strategic issue for the sustainable agriculture development and the international competitiveness of our agricultural products. In this paper, we compared and analyzed the status of commercialization of transgenic crops in China and world-wide.
Agriculture ; methods ; trends ; China ; Crops, Agricultural ; genetics ; Gene Transfer Techniques ; trends ; Plants, Genetically Modified ; genetics

Cell reprogramming is a progress in which the memory of a mature cell is erased and then the cell develops novel phenotype and function; ultimately, the fate of the cell changes. Cell reprogramming usually occurs at genes expression levels that no genomic DNA sequence change will be involved. By changing the programs of the genetic expressions of cells in terms of space and time, cell reprogramming alters the differentiation of cells and thus produces the required cells. Further research on cells reprogramming will elucidate the mechanisms that govern the cell development, and thus provides more information of the sources of seed cells used for regeneration medicine. More cells differentiated from many terminally differentiated cells will be obtained, which is extremely important for the understanding of molecular differentiation and for the development of cell replacement therapy. This article summarizes the classification, influencing factors, approaches and latest advances of cells reprogramming.
Animals ; Cell Dedifferentiation ; genetics ; Cell Differentiation ; genetics ; Cellular Reprogramming ; Gene Expression ; Humans ; Nuclear Transfer Techniques

OBJECTIVESTo investigate the effect of ionizing radiation on liposome-mediated gene delivery and find out a way to improve gene transfection.

METHODSPrior to liposome transfection, HR-8348 cells were irradiated at doses of 0, 2, 4, 8 Gy selected according to the surviving fraction line of HR-8348 cells after different dosage of radiation. After 36 h of liposome transfection, green fluorocytes were counted. The transfection efficiency was figured out and compared with each other.

RESULTSThe transfection efficiency of liposome-mediated gene delivery was 21.32%, 62.17%, 68.00%, 77.78% at the dose of 0, 2, 4, 8 Gy respectively and the clinical dose (2 Gy) was as high as 62.17%. Combined radiation and liposome-mediated gene delivery achieved the approximate transfection efficiency of virus vector.

CONCLUSIONIonizing radiation can improve the transfection efficiency of liposome-mediated gene delivery markedly and it is expected to treat human malignancy with liposome-mediated gene delivery combined with radiation.