Non-Human Primate Models for Human Xenotransplantation

描述（由申请人提供）：使用猪作为人体移植的器官供体代表了对终末期疾病患者可用器官日益短缺的解决方案。然而，野生型猪器官被预先存在的针对1-D-半乳糖基-（1->3）-1-D-半乳糖苷（gal 11，3gal）碳水化合物的天然抗体超急性排斥，所述碳水化合物在猪细胞上表达而在人类中不存在。来自gal基因敲除猪的器官已经被培育成潜在的供体，但最近几个实验室的研究表明，尽管这些器官不会发生超急性排斥反应，但它们仍然会在六个月内被排斥。急性体液排斥反应（AHXR）和血栓形成有助于这些移植物的死亡。已显示在移植有gal敲除供体器官的非人灵长类动物中诱导抗非gal异种抗体，但尚未确定这些抗体的特异性、来源和结构。目前可用的免疫抑制药物在预防AHXR方面无效。需要进一步的研究，以确定为什么发生急性体液异种移植排斥反应，并确定一种手段，以防止it. Our具体的目标提出了一个详细的和系统的研究异种抗体的起源和结合特异性，仍然拒绝在非人灵长类动物移植基因修饰器官的基因操作的异种移植。这项工作将提供信息，缺乏但必要的设计一个成功的方法来防止异种移植排斥反应。我们计划在我们的研究中检查的实验样品已经在gal敲除背景下繁殖，并且具有额外的转基因如CD 39以防止血栓形成。我们将进一步确定是否抗独特型抗体，确定B细胞产生异种抗体将防止AHXR在体内。这项资助提案将扩展我们在上一个资助期的工作，在上一个资助期，我们定义了编码非人灵长类动物野生型猪器官异种抗体的免疫球蛋白基因的结构，并鉴定了一种抗独特型抗体，该抗体具有定义产生异种抗体的B细胞的能力。 公共卫生相关性：使用专门培育的猪作为人体移植（异种移植）的器官供体，可以为许多可能因等待而死亡的患者提供器官。在移植物被抗体排斥之前，这些器官的功能持续了三到六个月。这项研究将确定编码这些抗体的基因，并将测试预防这种抗体反应的新方法。

DESCRIPTION (provided by applicant): The use of pigs as organ donors for human transplantation represents a solution to the escalating shortage of organs that are available for patients with end-stage diseases. Wild type pig organs are hyperacutely rejected, however, by pre-existing natural antibodies directed at the 1-D-galactosyl-(1->3)-1-D-galactoside (gal 11,3gal) carbohydrate, which is expressed on pig, cells and absent in humans. Organs derived from gal knockout pigs have been bred as potential donors, but recent studies from several laboratories have shown that although these organs do not undergo hyperacute rejection, they are still rejected within six months. Acute humoral rejection (AHXR) and thrombosis contribute to the demise of these grafts. Anti-non-gal xenoantibodies have been shown to be induced in non-human primates transplanted with gal knockout donor organs, but the specificity, origin and structure of these antibodies has not been determined. Currently available immunosuppressive drugs are ineffective in preventing AHXR. Additional research is needed to determine why acute humoral xenograft rejection occurs, and to define a means to prevent it. Our specific aims propose a detailed and systematic study on the origin and binding specificity of xenoantibodies that still reject genetically-manipulated xenografts in non-human primates transplanted with genetically-modified organs. This work would provide information that is lacking but necessary for the design of a successful approach to preventing xenograft rejection. The experimental samples that we plan to examine in our study have been bred on a gal knockout background and have additional transgenes such as CD39 to prevent thrombosis. We will further determine whether an anti-idiotypic antibody that identifies B cells producing xenoantibodies will prevent AHXR in vivo. This grant proposal will extend our work in the previous grant period in which we defined the structure of immunoglobulin genes encoding xenoantibodies to wild type pig organs in non-human primates and have identified an anti-idiotypic antibody with the ability to define B cells producing xenoantibodes. PUBLIC HEALTH RELEVANCE: The use of specifically bred pigs as organ donors for human transplantation (xenotransplantation) could provide organs for the many patients who may otherwise die waiting. These organs function for three to six months before the grafts are rejected by antibodies. This study will identify the genes that encode these antibodies and will test novel ways to prevent this antibody response.