Production of Polyclonal Antibodies in Eggs

描述（改编自申请人摘要）：Origen Therapeutics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。通过创造鸡，将内源性重链和轻链免疫球蛋白（Ig）基因“敲除”，并用人类重链和轻链Ig基因重组。从进化的角度来看，鸟类已经与哺乳动物分道扬镳，因此，鸡对保守的哺乳动物抗原产生高亲和力的抗体。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基因座并将人基因座插入种系结构，可以从鸡蛋中分离出人多克隆抗体。通过传统的技术，人单克隆抗体可以从鸡的b细胞中产生，b细胞携带灭活的内源性Ig基因座和人种系Ig基因座。这些鸡将提供独特的途径获得人多克隆抗体作为治疗剂。人多克隆抗体是理想的，因为它们与目标抗原上的几个表位结合，使它们对复杂抗原如细菌、真菌、病毒和毒素非常有效。目前，人多克隆抗体被用作抗多种疾病的抗感染剂，但市售的人供体免疫球蛋白制剂的滴度和对病原体的有效性各不相同，严重限制了它们的使用。尽管它们作为治疗手段很有吸引力，但免疫来源的高滴度人抗体是不可用的。Origen公司生产携带人类免疫球蛋白的鸡的技术是基于使用鸡胚胎干细胞。本申请旨在开发鸡的IgH和lgL链基因特异性删除方法。第一个目标是开发可靠的方法来转染和选择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位点的j段来阻止内源基因的翻译。正确靶向的胚胎干细胞将被注射到受体胚胎中，以产生种系嵌合体。将生产杂合子lgHKO和lgLKO鸟类，并将在第二阶段与携带人类IgH和lgL基因的鸟类交配。在ii期完成后，鸡对抗原产生人Ig反应，将产生一类新的治疗性蛋白质，为患有目前无法治疗的急性疾病和需要特异性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.