Production of Polyclonal Antibodies in Eggs

描述（改编自申请人的摘要）：Origen Therapeutics致力于在转基因鸡中开发药物产品。 特别是，Ongen的使命是开发高亲和力的人类抗体。通过产生内源性重链和轻链免疫球蛋白（IG）基因被“敲除”并用人重链和轻链IG基因重建的鸡。 在进化方面，鸟类已经从哺乳动物中分化出来，因此，鸡产生针对保守的哺乳动物抗原的高亲和力抗体。 此外，鸡产生具有高亲和力和亲合力的广泛的高滴度抗体库。 通过敲除内源性lg基因座并将人基因座插入种系构型，可以从鸡蛋中分离人多克隆抗体。 通过常规技术，人单克隆抗体可以从源自携带灭活的内源性IG基因座和种系构型的人IG基因座的鸡的B细胞产生。 这些鸡将提供获得人多克隆抗体作为治疗剂的独特途径。 人多克隆抗体是理想的，因为它们结合靶抗原上的几个表位，使它们对复杂抗原如细菌、真菌、病毒和毒素高度有效。 目前，人多克隆抗体被用作针对多种疾病的抗感染剂，但来自人供体的市售免疫球蛋白制剂在其效价和对病原体的有效性方面不同，严重限制了其利用。Origen生产携带人IG库的鸡的技术是基于使用鸡胚胎干细胞。 本申请提出开发特异性缺失鸡IgH和IgL链基因的方法。 第一个目标是开发用于分离和选择cES细胞的稳健方法，并显示转基因的种系传递。 第二个目的是靶向重链和轻链基因座的J区段以防止内源基因的翻译。将正确靶向的ES细胞注射到受体胚胎中以产生生殖系嵌合体。 将产生杂合IgHKO和IgLKO鸟，并在III期培育成携带人IgH和IgL基因的鸟。 在III期完成时，产生人IG以响应抗原的鸡将产生一类新的治疗性蛋白质，其为患有目前无法获得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.