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1.
    
BACKGROUND: Injection of DNA encoding exogenic proteins into muscle tissue combined with electroporation often results in a transient increase of the encoded protein concentration in the muscle and the blood. The reduction is normally due to an immune response against the exogenic protein but other factors may also be involved. How various electroporation parameters affect the concentration kinetics of syngenic and exogenic proteins is studied in relation to immune response and muscle damage after electroporation-mediated DNA transfer to muscle. METHODS: Electroporation was applied to mouse quadriceps and rat tibialis anterior muscles after injection of DNA encoding either secreted alkaline phosphatase (SEAP), beta-galactosidase (beta-gal), luciferase or a mouse IgG molecule. Protein concentrations in blood or muscle and antibody responses were measured for a period up to 3 months. Tissue inflammation and muscle cell damage were studied on muscle cross-sections and assessed by measuring the concentrations of creatine phosphokinase (CPK) in blood. RESULTS: Mice with the highest SEAP concentration in blood at day 7 also had the highest rate of decrease afterwards, the strongest antibody responses against SEAP and the highest acute levels of CPK in blood. DNA-transfected muscle fibers were significantly reduced in number from days 7 to 14. Mononuclear cells surrounded the reporter gene expressing muscle fibers, thus indicating a cellular immune response. When using DNA encoding a syngenic protein the protein concentration in blood was relatively stabile over a 3-month period, but showed different kinetics for various electroporation parameters. CONCLUSIONS: Our findings suggest that the optimal electroporation parameters for DNA vaccination may be different from the optimal parameters for long-term expression of genes encoding syngenic proteins.  相似文献   

2.
用电击孔(electroporation)转染方法已成功地使化学合成的红细胞生成素(EPO)基因在猿猴肾细胞(COS-7)中表达。对转染条件、表达质粒(pSVL-EPO)DNA含量及转染后不同时间表达产率的观察和研究表明:电击孔缓冲液及相应电压的选择与表达产率有关,且表达质粒DNA量在50~100μg,转染细胞存活率在50%左右时,表达效果好。在转染后24h,便可在细胞上清液中测到EPO活性,48~72h达高峰,EPO活性可达9.7U/ml。  相似文献   

3.
    
BACKGROUND: Application of electrical pulses after DNA injection into muscle increases expression of the encoded genes, and is shown to improve antigen-specific immune responses when used for DNA vaccination. In addition, electroporation causes tissue injury and inflammatory reactions. Together with immune stimulatory motifs in the injected DNA these factors may potentiate the immune response by acting as adjuvants for the antigen. Here, we have examined the role of these factors in promoting the efficiency of DNA vaccination. METHODS: We injected a plasmid DNA vector containing the gene Ag85B from M. tuberculosis into mouse quadriceps muscles followed by electroporation. Ag85B was under control of a Tet-responsive promoter, and was expressed either immediately or up to 28 days later by administrating doxycycline to the mice. Delayed expression was combined with injection of non-coding DNA or saline with or without electroporation to examine the ability of these factors to enhance the Ag85B-specific antibody response in the blood and cellular responses in the spleen. Blood samples were analysed with ELISA, while the number of Ag85B-specific IFN-gamma- and IL-4-producing spleenocytes was analysed with ELISpot. RESULTS: Delaying Ag85B expression by 5 or 28 days caused lower anti-Ag85B-specific IgG2a levels. In contrast, the IgG1 antibody response was not significantly affected. Injection of non-coding DNA followed by electroporation moderately increased the IgG2a response. Delaying the Ag85B expression by 28 days reduced the average number of Ag85B-specific IFN-gamma-producing spleenocytes by over 60%. No significant change in the number of IL-4-producing Ag85B-specific spleenocytes was observed. CONCLUSIONS: These results suggest that DNA and electroporation per se may act as good adjuvants in promoting efficient Th1-directed responses during DNA vaccination.  相似文献   

4.
    
Electroporation, as an established nonviral technology for breaching cell membrane, has been accepted for the delivery of nucleic acids. Despite satisfactory delivery efficiencies have been achieved on multiple cell kinds by simply exhausting all possible electrical parameters, electroporation is still inefficient, or even invalid, for various kinds of cells. This is largely due to the lack of comprehensive understanding of cell responses to electrical stimulation at biological aspect. Moreover, a systematically investigation of protein variation of electroporated cells is also required for biosafety evaluation before clinically applying electroporation. By employing quantitative proteomic analysis, the biological mechanism of electroporation is explored from the molecular level. The results reveal that electrical stimulations widely influence many biological processes including nucleic acid stabilization, protein synthesis, cytoskeleton dynamic, inflammation, and cell apoptosis. It is found that several antivirus‐related processes appeared in the enrichment results. Moreover, SAMD9, a broad spectrum antiviral and antitumor factor, is dramatically downregulated on easy‐to‐transfect cells while electroporation can not alter SAMD9 expression on hard‐to‐transfect cells, hinting that electroporation, a pure physical treatment, can induce antivirus‐like defensive responses and the altering of SAMD9 can be used to predict the effectiveness of electroporation on transfecting specific kinds of cells.  相似文献   

5.
The transient transfection of transgenes into oligodendrocytes offers an important tool for studying the function of proteins during myelin formation. Currently established procedures, however, have generally resulted in low survival rates and low levels of uptake of the transgene into primary oligodendrocyte progenitors. We describe an electroporation method which yields transient transfection of oligodendrocyte progenitors of up to 10–15% of the surviving cells, and provides approximately 104 surviving, transfected cells per electroporation reaction. In recent applications transgene expression persisted as the transfected progenitors progressed through subsequent stages of the oligodendrocyte lineage. This technique is expected to facilitate the study of the function of key proteins and lipids during the development of primary cultured oligodendrocytes.  相似文献   

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7.
    
Selective and reversible permeabilization of the cell wall permeability barrier is the focus for many biotechnological applications. In this article, the basic principles for reversible membrane permeabilization, based on biological, chemical, and physical methods are reviewed. Emphasis is given to electroporation (electropermeabilization) which tends to be the most popular method for membrane permeabilization and for introduction of foreign molecules into the cells. The applications of this method in industrial processes as well as the critical factors and parameters which affect the success of this approach are discussed. The different strategies developed throughout the years for increased transformation efficiencies of the industrially important amino acid-overproducing bacterium Corynebacterium glutamicum, are also summarized.  相似文献   

8.
    
When a cell's transmembrane potential is increased from a physiological one to more than 370 mV, the transmembrane current increases more than hundredfold within a millisecond. This is due to the formation of conductive pores in the membrane. We construct a model in which we conceive of pore formation as a voltage sensitive chemical reaction. The model predicts the logarithm of the pore formation rate to increase proportionally to the square of the voltage. We measure currents through frog muscle cell membranes under 8 ms pulses of up to 440 mV. The experimental data appear consistent with the model.  相似文献   

9.
介绍了磁性纳米颗粒介导基因转染的最新研究进展,面临的主要问题以及将来的发展方向。  相似文献   

10.
    
The pancreas is considered an important gene therapy target because the organ is the site of several high burden diseases, including diabetes mellitus, cystic fibrosis, and pancreatic cancer. We aimed to develop an efficient in vivo gene delivery system using non-viral DNA. Direct intra-parenchymal injection of a solution containing circular plasmid pmaxGFP DNA was performed on adult anesthetized ICR female mice. The injection site was sandwiched with a pair of tweezer-type electrode disks, and electroporated using a square-pulse generator. Green fluorescent protein (GFP) expression within the injected pancreatic portion was observed one day after gene delivery. GFP expression reduced to baseline within a week of transfection. Application of voltages over 40 V resulted in tissue damage during electroporation. We demonstrate that electroporation is effective for safe and efficient transfection of pancreatic cells. This novel gene delivery method to the pancreatic parenchyma may find application in gene therapy strategies for pancreatic diseases and in investigation of specific gene function in situ.  相似文献   

11.
阳离子脂质体的转染机制及转染效率影响因素   总被引:3,自引:0,他引:3       下载免费PDF全文
阳离子脂质体是一种非常具有发展前景的基因载体。简要介绍了阳离子脂质体的结构特点;着重讨论了阳离子脂质体作为基因载体时介导基因转移的机制以及在转染过程中对基因转染效率产生影响的主要因素。  相似文献   

12.
The current status of electromanipulation, that is, electrofusion and electroporation, of plant protoplasts is reviewed. Parameters for electromanipulation as well as their practical implications are discussed. Some comparisons with the use of polyethylene glycol are made and the advantages of electromanipulation are considered.  相似文献   

13.
    
Skin development is tightly temporally coordinated with its sensory innervation, which consists of the peripheral branches of the dorsal root ganglion (DRG) axons. Various studies suggest that the skin produces a long-range attractant for the sensory axons. However, the exact identity of the guidance cue(s) remains unclear. To reveal the detailed molecular mechanism that controls DRG axon guidance and targeting, manipulation of specific skin layers at specific time points are required. To test a variety of attractants that can be expressed in specific skin layers at specific timepoints, we combined in utero electroporation with the Tol2 transposon system to induce long-term transgene expression in the developing mouse skin, including in the highly proliferative epidermal stem cells (basal layer) and their descendants (spinous and granular layer cells). The plasmid solution was injected as close to the hindpaw plantar surface as possible. Immediately, electric pulses were passed through the embryo to transduce the plasmid DNA into hindpaw skin cells. Balancing outcome measurements including: embryo survival, transfection efficiency, and the efficiency of transgene integration into host cells, we found that IUE was best performed on E13.5, and using an electroporation voltage of 34V. After immunostaining embryonic and early postnatal skin tissue sections for keratinocyte and sensory axon markers, we observe the growth of axons into skin epidermal layers including areas expressing EGFP. Therefore, this method is useful for studying the interaction between axon growth and epidermal cell division/differentiation.  相似文献   

14.
A non-viral transfection method for oral mucosal cells was investigated using a modified transfection method and five commercial transfection reagents. The CellFECTINTM gave the highest expression of a transfected gene. When the mucosal cells were transfected with 0.3 ng DNA/cell, the transfection efficiency was optimal, and the production of a reporter protein increased up to ten times higher than those with the other transfection reagents.  相似文献   

15.
糖尿病基因治疗的新进展   总被引:3,自引:2,他引:1       下载免费PDF全文
目前,糖尿病的基因治疗主要分为替代基因治疗、免疫基因治疗和调节基因治疗三部分.近年来,随着人们对糖尿病本质的深层次揭示和现代分子生物学手段的发展,糖尿病基因治疗的内容不断增加.如:对K细胞的新认识,发现了胰腺十二指肠同源异形盒基因1(PDX-1)的新价值及单链胰岛素类似物基因的构建成功等.另外,还利用各种方法来提高转染效率,增加安全性.如使用腺病毒(HD)载体,应用电穿孔法(electroporation)等.  相似文献   

16.
    
We describe the use of direct injection of circular plasmid DNA and subsequent in vivo electroporation (EP) for efficient gene delivery to the ovarian cells, including follicular cells and oocytes of mice. When Trypan blue (TB) was injected into the central portion of an ovary by a glass micropipette, rapid dispersion of TB to each preantral and antral follicle was observed. Injections of lacZ-expressing plasmid DNA and subsequent in vivo EP resulted in transfection of follicles with efficiencies ranging from 8-60%, together with cells in the thecal portion of the ovary. Of the lacZ-positive follicles, some oocytes were also positive for lacZ activity. These findings suggest that a solution introduced inside the ovary is rapidly dispersed to each follicle. With this technique, we expect great progress in genetic engineering in murine ovary.  相似文献   

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18.
目的:建立可表达随机12肽库的逆转录病毒表达系统。方法:体外合成编码随机12肽的DNA片段;在最优化的实验参数和反应条件下将DNA片段克隆入带有EGFP标记的逆转录病毒载体后分批次电击转化大肠杆菌,合并转化所得菌液即为可表达随机12肽库的逆转录病毒原始载体库;半固体扩增法扩增该原始载体库,提取质粒并转染GP2-293包装细胞,在EGFP表达最强的时间点收集细胞培养上清,即为可表达随机12肽库的逆转录病毒库。结果:可表达随机12肽库的逆转录病毒原始载体库的库容量为3.14×10^6cfu;扩增后的逆转录病毒载体库滴度为5.2×109cfu/mL,库容量为2.34×1011cfu;转染了已扩增的载体库质粒后的GP2-293包装细胞可以成功地表达随机12肽库。结论:建立了可表达随机12肽库的逆转录病毒表达系统,为抗病毒寡肽的筛选以及进一步的深入研究奠定了良好的基础。  相似文献   

19.
脂质体法和电穿孔法转染哺乳动物细胞研究   总被引:3,自引:0,他引:3       下载免费PDF全文
用脂质体法和电穿孔法分别转染Cos-7,Vero和Namalwa细胞.发现脂质体法在转染效率和操作方便方面比电穿孔法优越,而电穿孔法对细胞种类的适用性方面似乎比脂质体法广. 结果表明,电穿孔法能转染Cos-7,Namalwa和Vero细胞,而用脂质体法只能转染Cos-7和Vero细胞.  相似文献   

20.
无机纳米粒子作为基因载体的研究进展   总被引:2,自引:0,他引:2  
李新新  侯森  冯喜增 《生命科学》2008,20(3):402-407
转染是将具生物功能的核酸转移、运送到细胞内,并使其在细胞内维持生物功能的过程。作为现代生物化学和分子生物学中的一种主要技术手段,转染对于基因治疗有重要的意义。无机纳米粒子作为基因载体受到人们日益广泛的关注,其具有易于制备,可进行多样化的表面修饰等多种优势。本文将概述无机纳米粒子作为基因载体的现状及其对基因表达的影响。  相似文献   

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