DEVELOPMENT OF HYBRID HUMAN/PIG LIVER XENOGRAFTS

由于人类器官捐赠者的严重短缺，大多数肝移植候选人从未接受过器官移植。目前，每年大约进行4000例肝移植。超过11,000名高优先级候选人正在等待移植。据估计，如果器官可用，每年有多达5万人可以从肝脏移植中受益。猪肝移植可以解决这一不足，但严重的排斥反应和功能异常的问题阻碍了其应用。这项提案将开发初步技术，以生产重新填充人类肝细胞的猪肝移植。然后，肝脏会产生适当的人类蛋白质。该项目将使用Gala Design LLC开发的一种新的高效卵母细胞转基因方法来生产基因工程猪。该提案中使用的其他方法包括细胞移植、分子生物学和免疫组织化学技术。这项技术将为那些没有人类捐赠者的人提供肝脏移植。当与其他地方发展的代孕耐受相结合时，受者对免疫抑制的需求将显著减少，以防止排斥反应。除了移植，这种混合移植物将用于毒理学研究，并作为病毒性肝炎研究的模型。拟议的商业应用：用人类肝细胞重新填充的杂交猪肝将为没有人类供体的受者提供功能性异种肝移植。嵌合体猪对于研究病毒性肝炎等人类疾病以及作为评估人类肝细胞损伤的毒理学系统将具有额外的价值。该系统可以作为一种经济有效的生物反应器来扩增人肝细胞用于细胞移植。

Because of a severe shortage of human organ donors, most candidates for a liver transplant never receive one. Currently, approximately 4000 liver transplants are performed annually. Over 11,000 high priority candidates are waiting for a transplant. It has been estimated that as many as 50,000 could benefit from a liver transplant each year, if the organs were available. Pig liver xenografts could resolve the shortage, but the problems of severe rejection and abnormal function preclude their use. This proposal will develop initial technology to produce pig liver xenografts repopulated with human hepatocytes. The livers would then produce the appropriate human proteins. The program will produce genetically engineered pigs using a new efficient method for transfecting oocytes, developed by Gala Design LLC. Other methods used in this proposal include cellular transplants, molecular biology and immunohistochemistry techniques. The technology would provide liver grafts for those without human donors. When combined with surrogate tolerogenesis, developed elsewhere, the recipients would have a significantly decreased need for immune suppression to prevent rejection. In addition to transplantation, the hybrid grafts would be useful for toxicology studies and as a model for the study of viral hepatitis. PROPOSED COMMERCIAL APPLICATION: Hybrid pig livers repopulated with human hepatocytes would provide functional liver xenografts for recipients without human donors. Chimeric pigs would be additionally valuable for the study of human diseases such as viral hepatitis and as a toxicology system for assessing injury to human hepatocytes. The system could be used as a cost effective bioreactor to expand human hepatocytes for cell transplants.