纳米生物技术基因治疗载体研究进展

基因治疗已在治疗多种人类重大疾病如遗传病、肿瘤等方面显示出良好的应用前景,但也面临着巨大的挑战,其中之一就是需要安全、高效、靶向的载体系统。纳米生物材料,如脂质体、聚丙交酯-乙交酯(PLGA),聚乳酸(PLA)等,由于具有良好的生物安全性、可方便有效地实现基因靶向性及高效表达和缓释,成为制备高效、靶向的基因治疗载体系统的良好介质,日益在基因治疗载体系统中受到广泛重视。本文综述了目前在基因治疗领域中常用的纳米载体的生物学特性,以及它们的最新研究进展。     

Gene Therapy and Arthritis

Inflammation Research -     

血友病的基因治疗

血友病是基因治疗临床实验最早获得成功的遗传性疾病.血友病不仅是单基因疾病治疗的最佳病种,因其清楚的遗传背景、完备的动物模型以及客观方便的观察指标,也成为检验基因治疗系统最为可信的模型.本文综述血友病基因治疗的代表性文献,对基因治疗血友病的进展、面临的困难以及可能的解决途径及其前景作一简要综述.     

Gene Therapy in Experimental Autoimmune Encephalomyelitis

Gene therapy traditionally has been associated with gene replacement, where exogenous recombinant DNA is introduced ex vivo into somatic cells that are then introduced back into the patient as a way to correct an inherited genetic defect. However, several novel gene therapy strategies for treating autoimmune diseases recently have emerged. Strategies involving the use of several types of DNA vaccines, the application of various viral vectors, and the use of diverse cellular vectors have shown promise in inhibiting autoimmune-mediated inflammation and repairing tissue damaged as a result of autoimmune attack. In the current review, we examine and discuss the development and proposed use of emerging gene therapy strategies for the treatment of autoimmune disease with specific emphasis on experimental autoimmune encephalomyelitis (EAE), an animal model widely used in multiple sclerosis (MS) research.     

逆转录病毒介导的基因治疗中的安全性检测

逆转录病毒介导的基因治疗中安全性的最大危险是产生有复制能力的逆转录病毒（RCR）。本实验对经3T3扩增的样品进行 S~+L~-分析、标记拯救分析和PCR扩增方法检测RCR。比较三种方法,标记拯救分析比S~+L~-分析结果容易判断,且PCR可以从10~5个无病毒基因的细胞中检测出一个带有病毒基因的细胞。3T3扩增可提高灵敏度约10倍。安全性是基因治疗首要考虑的问题,本方法为其提供了保证。     

Gene Therapy for Autoimmune Disorders

Although many autoimmune disorders do not have a strong genetic basis, their treatment may nevertheless be improved by gene therapies. Most strategies seek to transfer genes encoding immunomodulatory products that will alter host immune responses in a beneficial manner. Used in this fashion, genes serve as biological delivery vehicles for the products they encode. By this means gene therapy overcomes obstacles to the targeted delivery of proteins and RNA, and improves their efficacy while providing a longer duration of effect, and, potentially, greater safety. Additional genetic strategies include DNA vaccination and the ablation of selected tissues and cell populations. There is considerable evidence from animal studies that gene therapies work: examples include the treatment of experimental models of rheumatoid arthritis, multiple sclerosis, diabetes, and lupus. Pre-clinical success in treating animal models of rheumatoid arthritis has led to the first clinical trial of gene therapy for an autoimmune disease. In this Phase I study, a cDNA encoding the interleukin-1 receptor antagonist was transferred to the knuckle joints of patients with advanced rheumatoid arthritis. Two additional clinical trials are in progress. It is likely that gene therapy will provide effective new treatments for a wide range of autoimmune disorders.     

Gene Therapy for Cardiovascular Disease

The last decade has seen substantial advances in the developmentof gene therapy strategies and vector technology for the treatment of a diverse number of diseases, with a view to translating the successes observed in animal models into theclinic. Perhaps the overwhelming drive for the increase in vascular gene transfer studies is the current lack of successful long-term pharmacological treatments for complex cardiovascular diseases. The increase in cardiovascular disease to epidemic proportions has also led many to conclude that drug therapy may have reached a plateau in its efficacy and that gene therapy may represent a realistic solution to a long-term problem. Here, we discuss gene delivery approaches and target diseases.     

Gene Therapy for Cystic Fibrosis

Cystic Fibrosis (CF) is an autosomal recessive disorder due to mutations in the CF transmembrane conductance regulator (CFTR) gene that lead to defective ion transport in the conducting pulmonary airways and exocrine glands. Through a process that is not fully understood, CFTR defects predispose affected patients to chronic endobronchial infections with organisms such as Pseudomonas aeruginosa and Staphylococcus aureus. Following the discovery of the CFTR gene in 1989, CF became one of the primary targets for gene therapy research. Early enthusiasm surrounded the new field of gene therapy during most of the 1990s and it led academics and clinicians on a big effort to apply gene therapy for cystic fibrosis. Clinical studies have been pursued using recombinant adenovirus, recombinant adeno-associated virus, cationic liposomes, and cationic polymer vectors. Although to this date no dramatic therapeutic benefits have been observed, a lot of information has been gained from the pre-clinical and clinical studies that were performed. This learning curve has led to the optimization of vector technology and an appreciation of immune and mechanical barriers that have to be overcome for successful delivery.     

Gene Therapy for Infectious Diseases

Gene therapy is being investigated as an alternative treatment for a wide range of infectious diseases that are not amenable to standard clinical management. Approaches to gene therapy for infectious diseases can be divided into three broad categories: (i) gene therapies based on nucleic acid moieties, including antisense DNA or RNA, RNA decoys, and catalytic RNA moieties (ribozymes); (ii) protein approaches such as transdominant negative proteins and single-chain antibodies; and (iii) immunotherapeutic approaches involving genetic vaccines or pathogen-specific lymphocytes. It is further possible that combinations of the aforementioned approaches will be used simultaneously to inhibit multiple stages of the life cycle of the infectious agent.     

Gene Therapy for Brain Tumors

Gene therapy has opened new doors for treatment of neoplastic diseases. This new approach seems very attractive, especially for glioblastomas, since treatment of these brain tumors has failed using conventional therapy regimens. Many different modes of gene therapy for brain tumors have been tested in culture and in vivo. Many of these approaches are based on previously established anti-neoplastic principles, like prodrug activating enzymes, inhibition of tumor neovascularization, and enhancement of the normally weak anti-tumor immune response. Delivery of genes to tumor cells has been mediated by a number of viral and synthetic vectors. The most widely used paradigm is based on the activation of ganciclovir to a cytotoxic compound by a viral enzyme, thymidine kinase, which is expressed by tumor cells, after the gene has been introduced by a retroviral vector. This paradigm has proven to be a potent therapy with minimal side effects in several rodent brain tumor models, and has proceeded to phase 1 clinical trials. In this review, current gene therapy strategies and vector systems for treatment of brain tumors will be described and discussed in light of further developments needed to make this new treatment modality clinically efficacious.     

DMD启动子在基因治疗中作用的研究进展

假肥大型进行性肌营养不良(DMD)是一类X连锁隐性退行性肌肉萎缩病.目前,关于DMD基因外显子缺失,内含子断裂点以及所编码dystmphin蛋白的结构已经明确,这对DMD的临床诊断有很大价值;但对于基凶治疗来说,明确DMD基因启动子的顺式元件以及反式因子的结构及相互作用关系是十分重要的,这些元件的相互作用对于dystrophin蛋白的转录水平及表达起关键的调节作用;研究表明,人工合成的DMD肌启动子活性比生物体内DMD基因启动子活性高,找出启动子关键元件构建特异性高效启动子,将其应用于基因治疗,这是一条新的途径.     

脊柱融合的基因治疗

稳定的脊柱融合与相邻椎骨的融合有关，经典的脊柱融合手术采用剥离椎骨，自体髂骨植骨融合术，虽然应用自体髂骨植骨被认为是植骨融合的金标准，但是它常伴有并发症出现，基因治疗被认为是促进脊柱关节固定融合的新途径，研究表明在动物模型中应用腺病毒，脂质体搭载人骨形成蛋白（hBMP)基因族能促进脊柱融合，有关在动物模型中通过基因转染促进脊柱融合的研究，本文对此作简要介绍，弄清楚骨形成中基因的表达和开发出新的基因转染载体是目前研究的重点，相信在不远的将来，基因治疗脊柱融合能在临床中得到应用。     

Gene Therapy for Rheumatoid Arthritis

Rheumatoid arthritis (RA) was one of the earliest targets for gene therapy. Since the first clinical trial involving gene therapy in RA was initiated in 1996, eight clinical trials have been conducted assessing gene therapy in RA. Gene therapy has benefited from advances in biologics in terms of the increasing choice of novel, efficient targets to treat RA and also from the optimization of the delivery systems. Several strategies are possible; one of particular interest is local gene therapy directed to rheumatic joints, which avoids systemic vector diffusion. In this review, we discuss (i) gene therapeutic approaches that have been attempted for patients with RA, and (ii) novel strategies that are in development for delivery into patients. We analyze the advantages and disadvantages of the various approaches and how best to optimize them with regard to choosing the most promising vectors and strategies to allow for efficient, long-term, safe delivery of gene therapy in RA.     

线粒体病的基因治疗

线粒体病是一组因线粒体DNA缺失或突变而致氧化磷酸化及能量供应异常的疾病,目前该类疾病的治疗主要是支持治疗。然而由于线粒体结构和功能的特殊性,该疗效并不确切。因此,线粒体病的基因治疗显得越来越迫切和重要。目前,基因治疗的策略包括降低突变型mtDNA/野生型mtDNA的比例、错位表达、输入其他同源性基因以及利用限制性内切酶修复突变型mtDNA等。     

Reporting Adverse Events in Gene Therapy Studies

The reporting of adverse events occurring in gene therapy studies is currently under discussion. There are many agencies involved in the reporting of adverse events, often with reporting guidelines that are unique to each organisation. Guidelines differ according to the type of event (adverse event, adverse drug reaction, unexpected adverse drug reaction, serious adverse event and serious adverse drug reaction). While there is a move toward making guidelines more stringent in the US, there is concern that this will increase the number of reports of unrelated events, create confusion from a global perspective, and increase public concern needlessly.     

骨形成蛋白介导的基因治疗研究进展

基因治疗是指通过导入基因的功能片段改善机体生理状况或者治疗疾病.利用基因治疗可在骨缺损或骨折局部释放骨形成蛋白（bone morphogenetic proteins,BMP）,并且无需异体载体,方法包括体内法和离体法.BMP基因治疗可以促进骨和软骨形成、脊柱融合、颌面骨和牙齿修复、肌腱韧带形成,此外对椎间盘退变性疾病也可采用BMP基因治疗.总之BMP基因治疗方法经济有效,是有前景的治疗手段.     

基因治疗中的非病毒载体

添加、修复或替换基因从而达到直接排除病因是基因治疗的目的，也是用于治疗可遗传和获得性疾病的治疗方法。它包括目的基因、载体和靶细胞三个方面，其中载体在整个转染过程中起着关键的作用。非病毒载体是该研究领域的热点之一，虽然转染效率不如病毒载体，但其无毒、无免疫反应、性质可调且制备方便。本文主要就非病毒载体的转染机理及优化策略作一综述。