Production of Polyclonal Antibodies in Eggs

描述(摘自申请者的摘要)：Origen Treateutics致力于开发转基因鸡的药物产品。特别是，Ongen的使命是开发高亲和力的人类抗体。通过创造内源性重链和轻链免疫球蛋白(Ig)基因被“敲除”并与人类重链和轻链Ig基因重组的鸡。在进化方面，鸟类与哺乳动物有所不同，因此，鸡产生了针对哺乳动物保守抗原的高亲和力抗体。此外，鸡产生广泛的高滴度抗体，具有高亲和力和亲和力。通过敲除内源性LG基因座并以胚系形式插入人类基因座，可以从鸡的鸡蛋中分离出人的多克隆抗体。通过常规技术，可以从携带灭活的内源性Ig基因座的鸡的B细胞和具有胚系构型的人Ig基因座的B细胞中产生人源单抗。这些鸡将提供独特的途径，将人类多克隆抗体作为治疗剂。人类多克隆抗体是理想的，因为它们与靶抗原上的几个表位结合，使它们对细菌、真菌、病毒和毒素等复杂抗原非常有效。目前，人类多克隆抗体被用作各种疾病的抗感染剂，但来自人类捐赠者的商用免疫球蛋白制剂在滴度和对病原体的有效性方面存在差异，严重限制了它们的应用。尽管它们在治疗方面很有吸引力，但来自免疫来源的高滴度人类抗体是不可用的。Origen生产携带人类免疫球蛋白谱系的鸡的技术是基于使用鸡胚胎干细胞。本申请建议开发特异性删除鸡IgH和LGL链基因的方法。第一个目标是发展可靠的方法，用于转染和选择CES细胞，并显示转基因的种系传播。第二个目的是针对重链和轻链基因的J-片段，以防止内源基因的翻译。靶向正确的ES细胞将被注射到受体胚胎中，以产生生殖系嵌合体。将产生杂合的lgHKO和lgLKO禽类，并将其与携带人类IgH和LGL基因的禽类进行Ill期繁殖。在Ill阶段完成后，鸡将产生一种新型的治疗性蛋白质，为患有目前尚无治疗方法的急性疾病和需要特定、高滴度多克隆抗体的慢性疾病的患者提供高效的被动免疫。

DESCRIPTION (Adapted from the applicant's abstract): Origen Therapeutics is committed to developing pharmaceutical products in transgenic chickens. In particular, Ongen's mission is to develop high affinity human antibodies. by creating chickens in which the endogenous heavy and light chain immunoglobulin (Ig) genes are 'knocked-out' and reconstituted with the human heavy and light chain Ig genes. In evolutionary terms, birds have diverged from mammals and, therefore, the chicken produces high affinity antibodies against conserved mammalian antigens. In addition, chickens produce a wide repertoire of high titer antibodies that possess high affinity and avidity. By knocking out the endogenous lg loci and inserting the human loci in germline configuration, human polyclonal antibodies can be isolated from the chicken's egg. By conventional techniques, human monoclonal antibodies can be produced from B-cells derived from chickens carrying inactivated endogenous Ig loci and human Ig loci in germline configuration. These chickens will provide unique access to human polyclonal antibodies as therapeutic agents. Human poylclonal antibodies are desirable because they bind to several epitopes on the target antigen, making them highly effective against complex antigens such as bacteria, fungi, viruses and toxins. Currently, human polyclonal antibodies are used as anti-infectious agents against a variety of diseases but commercially available immunoglobulin preparations from human donors vary in their titer and effectiveness for pathogens, severely limiting their utilization. In spite of their attractiveness as therapeutics, high titer human antibodies from immunized sources are not available.Origen's technology for producing chickens carrying the human Ig repertoire is based on the use of chicken embryonic stem cells. This application proposes to develop methods to specifically delete the chicken IgH and lgL chain genes. The first aim is to develop robust methods for transfecting and selecting cES cells and to show germline transmission of a transgene. The second aim is to target the J-segments of the heavy and light chain loci to prevent translation of the endogenous genes. Correctly targeted ES cells will be injected into recipient embryos to produce germline chimeras. Heterozygous lgHKO and lgLKO birds will be produced and will be bred in phase Ill to birds carrying the human IgH and lgL genes. At the completion of phase Ill, chickens producing human Ig in response to antigen will yield a novel class of therapeutic proteins providing highly effective passive immunity to patients suffering from acute diseases for which therapy is not currently available and chronic diseases that require specific, high titer polvclonal antibodies.