Brink M F, Bishop M D, Pieper F R
Infigen Inc., Deforest, Wisconsin 53532, USA.
Theriogenology. 2000 Jan 1;53(1):139-48. doi: 10.1016/s0093-691x(99)00247-2.
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.
在千年之交，由于基于人类重组蛋白的新疗法的出现，疾病治疗领域正在发生一场革命。对这类药用蛋白不断增长的需求是安全且大规模生产平台发展的重要驱动力。由于人类蛋白质的功效通常取决于其氨基酸组成以及各种翻译后修饰，许多重组人类蛋白质只有在哺乳动物细胞中产生时才能以生物活性构象获得。因此，哺乳动物细胞培养系统常被用于表达。然而，这种方法通常以生产能力有限和成本高而闻名。相比之下，在转基因农场动物，特别是牛的乳汁中生产（人类）重组蛋白，提供了一种安全的替代方法，且不受蛋白质产量有限的限制。此外，与细胞培养相比，乳汁生产极具成本效益。尽管转基因农场动物技术在十年前还处于起步阶段，但如今它即将发挥其潜力，提供那些无法以其他方式足量生产或无法以可承受成本生产的治疗性蛋白质。自1989年以来，我们一直处于这一发展的前沿，第一头转基因公牛赫尔曼的诞生就是例证。在本通讯中，我们将概述多年来我们用于培育转基因奠基动物和生产畜群的方法。我们最初的策略基于显微注射，这在当时是培育转基因牛的唯一可行选择。最近，我们采用了一种更强大的方法，即基于核移植的应用。正如我们将说明的，这种策略在培育转基因动物的整体效率、产品一致性和产品开发时间方面带来了突破。
