动物乳腺生物反应器的应用与展望

应用转基因技术生产乳腺生物反应器可以获得高效、安全、足量的人类重组蛋白、药用蛋白及其目的蛋白.本文概述了制备转基因动物过程中目的基因选择、载体构建等技术环节的研究现状;通过叙述乳腺生物反应器的原理和应用现状来分析乳腺生物反应器的优势及特点,为乳腺生物反应器的发展和应用奠定理论基础.     

动物乳腺生物反应器研究进展

利用转基因家畜的乳腺生产人类重组蛋白,可以高效获得安全、足量的药用蛋白。本在简要介绍乳腺生物反应器的基本原理及优越性的基础上,对其目的基因、表达载体和转基因技术在国内外的研究现状加以综述,着重探讨了体细胞核移植方法生产乳腺生物反应器的优越性及面临的技术问题。     

转基因技术在制备动物乳腺生物反应器中的应用和发展

利用乳腺生物反应器可以高效获得安全、足量的药用蛋白,在制药工业中具有广阔的应用前景。但是,目前采用的转基因技术由于其各自固有的局限性,未能使乳腺生物反应器的研究取得长足的进步。基因打靶技术和核移植技术的发展为乳腺生物反应器的开发注入了新的活力。本文综合近年来国内外文献,阐述了各种转基因技术的优点与缺陷,同时说明了构建“体细胞打靶-克隆技术体系”在制备大动物的乳腺生物反应器中的必要性。     

利用动物乳腺生物反应器生产药用蛋白

动物乳腺生物反应器是利用动物乳腺特异性启动子调控元件指导外源基因在乳腺中特异性表达,并从转基因动物奶液中获取重组蛋白。应用动物乳腺生物反应器生产药用蛋白具有生产方式简单,产量大,蛋白能进行翻译后修饰等优点,是具有广阔前景的生物医药产业。本文仅就动物乳腺生物反应器的建立、检测、目的蛋白的分离纯化以及存在的问题等作一综述。     

动物乳腺生物反应器的研究进展

利用转基因动物反应器生产药用蛋白是生物技术领域的一次革命,而通过动物乳腺是最好的渠道,药物蛋白可通过转基因动物的乳腺随乳汁分泌出来,产量高、易纯化,因此乳腺类似于一个制药工厂。国外已有多种蛋白通过乳朱反应器来制备,有些已进入临床研究阶段。本文主要介绍乳腺生物反应器的研究进展情况。     

转基因动物乳腺生物反应器相关技术及研究进展

转基因动物乳腺生产人类重组蛋白人血清白蛋白(h SA)、人纤维蛋白原(h FIB)、人蛋白C(h PC)、人凝血因子(h F-Ⅷ)和(h F-Ⅸ)等具有较高市场潜力,使其在医学领域获得广泛应用。对转基因动物乳腺生物反应器的优势、目的基因选择、载体构建、基因工程技术、重组蛋白在肿瘤治疗上的应用、当前困境和未来前景等方面进行较为全面的综述,以期能有助于转基因动物生物反应器的研究。此外较详细地探讨了利用CRISPR-Cas基因打靶技术生产高表达量的人类重组蛋白的可能性。     

药用蛋白质乳腺生物反应器的制作技术及新方法进展

用乳腺生物反应器生产人类珍稀的药用蛋白已经构成了现代生物技术的一个重要领域.与其他的生物工程方法比起来,用乳腺生物反应器生产人类珍稀的药用蛋白具有更多的优点.这一生物技术的实际应用依赖于基因的时空表达调控操作和可靠的转基因动物制作方法.综述了这一技术的优点,概括描述了了乳腺生物反应器表达载体的构建方法,及转基因动物的制作方法.讨论了这些方法的优缺点及技术改进的发展方向,特别是介绍了最近出现的、有研究和应用价值的用精原干细胞制作转基因动物的方法.     

转基因牲畜乳腺生物反应器的发展及应用

利用转基因牲畜乳腺生产人类重组蛋白方法能够获得高效、经济、安全、足量的药用蛋白.对转基因牲畜乳腺生物反应器的发展过程、制备技术、获得要素以及研究进展加以综述,并对其未来发展方向进行了展望.     

基因打靶技术在乳腺生物反应器中的应用

利用转基因动物的乳腺生产人类重组蛋白,可以获得安全而有效的药用蛋白.目前采用的转基因技术由于其固有的局限性,未能使乳腺生物反应器的研究取得长足的进步.基因打靶克服了随机整合的盲目性和危险性,是一种理想的修饰、改造生物遗传物质的方法.简述了制备乳腺生物反应器过程中靶细胞、基因打靶的策略、打靶位点及问题,并对其发展方向进行了小结及展望.     

乳腺生物反应器的研究现状和产业化前景

转基因动物乳腺生物反应器是伴随转基因动物技术而发展起来的一项高新生物技术。利用这项技术,我们可以从动物乳汁中源源不断地获取用于医疗或保健目的的有生物活性的基因产物。这是一种全新的蛋白质生产模式,它将成为许多国家的重要支柱产业之一。本文介绍了乳腺生物反应器的基本概念和基本原理;概述了制备过程中的目的基因选择、载体构建、转基因等技术环节的研究现状;分析了乳腺生物反应器的优势及存在的问题,并就其产业化前景进行了展望。     

Developing efficient strategies for the generation of transgenic cattle which produce biopharmaceuticals in milk

At the close of the millennium, a revolution in the treatment of disease is taking shape due to the emergence of new therapies based on human recombinant proteins. The ever-growing demand for such pharmaceutical proteins is an important driving force for the development of safe and large-scale production platforms. Since the efficacy of a human protein is generally dependent on both its amino acid composition as well as various post-translational modifications, many recombinant human proteins can only be obtained in a biologically active conformation when produced in mammalian cells. Hence, mammalian cell culture systems are often used for expression. However, this approach is generally known for limited production capacity and high costs. In contrast, the production of (human) recombinant proteins in milk of transgenic farm animals, particularly cattle, presents a safe alternative without the constraint of limited protein output. Moreover, compared to cell culture, production in milk is very cost-effective. Although transgenic farm animal technology was still in its infancy a decade ago, today it is on the verge of fulfilling its potential of providing therapeutic proteins that can not be produced otherwise in sufficient quantities or at affordable cost. Since 1989, we have been at the forefront of this development, as illustrated by the birth of Herman, the first transgenic bull. In this communication, we will present an overview of approaches we have taken over the years to generate transgenic founder animals and production herds. Our initial strategies were based on microinjection; at the time the only viable option to generate transgenic cattle. Recently, we have adopted a more powerful approach founded on the application of nuclear transfer. As we will illustrate, this strategy presents a breakthrough in the overall efficiency of generating transgenic animals, product consistency, and time of product development.     

制备动物乳腺生物反应器的问题和对策

动物乳腺是理想的用于生产复杂的生物活性蛋白的生物反应器。目前,显微注射仍然是制备大型转基因动物的主要方法,但外源基因整合效率低下和位置效应还需要解决。要解决这两个问题,人们探索了几种策略。尽管使用转染的体细胞和基因打靶的体细胞作为核移植的供体的动物克隆技术还在改善中,但是这一技术是有应用前景的转基因牲畜的方法。在转基因载体中使用LCR和MAR序列可显著提高表达水平和转基因效率。YAC、BAC作为理想的转基因载体可能因为它们能容纳基因座的所有元件。虽然这些技术和方法还存在不完善之处,但其发展将极大地提高动物乳腺生物反应器的整合率和表达水平。     

Genetic modification of animals in the next century

Since the initial demonstration in 1982 of profound phenotypic effects stemming from the expression of a single transgene, genetic engineering has revolutionized fundamental biological and biomedical research. The application of transgenic technology to farm animals has held the promise of being able to improve animal agriculture significantly and has resulted in a new industry, i.e., the successful expression of foreign proteins in the mammary gland for the pharmaceutical industry. Work over the last few years in model species (e.g., the mouse) and new technical developments such as cloning have now set the stage for the initial application of transgenic technology for the improvement of farm animals. Major limitations that remain are the lack understanding of which genes we should transfer in order to alter quantitative production traits usefully and the low efficiency of producting transgenic founders. Furthermore, more research is needed concerning the consequences and potential problems arising from the integration of transgenes into populations with varying genetic backgrounds. Recent advances suggest that within the first decade of the 21 st century the first transgenic animals will become available to the livestock industry, with acceptance depending upon their cost versus their potential economic benefit to the producers.     

DNA甲基化和组蛋白修饰在克隆动物发育过程中的作用

体细胞核移植在农业应用、生产疾病模型动物、转基因家畜或产生人胚胎干细胞来治疗人类的疾病方面有巨大的应用潜力。虽然已经成功克隆出多种哺乳动物,但该技术仍存在一些未解决的问题,包括产生克隆动物的效率低和克隆动物的异常等。异常的表观遗传重编程是克隆胚胎发育失败的一个重要因素。文章重点论述了DNA甲基化、组蛋白修饰及其与克隆胚胎发育的关系。了解表观遗传调控机制有助于解决核移植技术中存在的问题,有利于更好地应用这项技术。     

Transgenic farm animals - A critical analysis

The notion of directly introducing new genes or otherwise manipulating the genotype of an animal is conceptually straightforward and appealing from the standpoints of both speed and precision with which phenotypic changes can be made. Thus, it is little wonder that the imagination of many animal scientists has been captivated by the success others have achieved in introducing foreign genes into mice. Transgenic mice not only exhibit unique phenotypes, but they also pass those traits on to their progeny. However, before transgenic farm animals become a common component of the livestock industry, a number of formidable obstacles must be overcome. In this review we attempt to identify the critical issues that should be considered by both those currently working in the field and those scientists considering the feasibility of initiating a transgenic livestock project. The inefficiency of producing transgenic animals has been well documented. This does not constrain investigators using laboratory animal models, but it has a major impact on applying transgenic technology to farm animals. The molecular mechanisms of transgene integration have not been elucidated, and as a consequence it is difficult to design strategies to improve the efficiency of the process. In addition to the problems associated with integration of new genes, there are inefficiencies associated with collecting and culturing fertilized eggs as well as embryo transfer in farm animals. Transgenic farm animal studies are major logistical undertakings. Even in the face of these practical hindrances, some may be pressured by administrators to embrace this new technology. As powerful as the transgenic animal model system is, currently there are limits to the kinds of agricultural questions that can be addressed. Some uses are so appealing, however, that several commercial organizations have explored this technology. Within the next decade or two, it is likely that many of the technical hurdles will be overcome. Combining new techniques with a better understanding of the genetic control of physiological systems will make it possible to improve the characteristics of farm animals in highly imaginative ways.     

The contribution of farm animals to human health

Farm animals and their products have a longstanding and successful history of providing significant contributions to human nutrition, clothing, facilitation of labour, research, development and medicine and have thus been essential in improving life expectancy and human health. With the advent of transgenic technologies the potential of farm animals for improving human health is growing and many areas remain to be explored. Recent breakthroughs in reproductive technologies, such as somatic cloning and in vitro embryo production, and their merger with molecular genetic tools, will further advance progress in this field. Here, we have summarized the contribution of farm animals to human health, covering the production of antimicrobial peptides, dietary supplements or functional foods, animals used as disease models and the contribution of animals to solving urgent environmental problems and challenges in medicine such as the shortage of human cells, tissues and organs and therapeutic proteins. Some of these areas have already reached the level of preclinical testing or commercial application, others will be further advanced only when the genomes of the animals concerned have been sequenced and annotated. Provided the necessary precautions are being taken, the transmission of pathogens from animals to humans can be avoided to provide adequate security. Overall, the promising perspectives of farm animals and their products warrant further research and development in this field.     

Expression of eukaryotic recombinant proteins and deriving them from the milk of transgenic animals

Expression in milk of transgenic farm animals is one of the most effective ways to produce eukaryotic recombinant proteins. In this review, we discuss the problems of the appropriateness of selecting this expression system for the production of proteins and the development characteristics of appropriate production processes.     

提高转基因表达水平的策略

随着转基因相关技术的发展,转基因动物技术在许多方面得到了成功应用.但外源基因在体内的表达仍然难以预测,特别是大动物的转基因,由于制备效率低下,因而难以筛选出足够的高表达的阳性动物数.基因表达调控研究对提高外源基因在动物体内的表达水平提供了一些新手段,本就避免转基因的位置效应、控制外源基因在动物宿主基因组中的整合、提高转基因的表达效率、构建转基因载体和使用外源基因需要注意的问题等进行综述.