Xenotransplantation

Abstract

Xenotransplantation has the potential to alleviate the critical shortage of organs for transplantation in humans. However, multiple barriers exist to the broad clinical application of xenotransplantation, including immunologically mediated graft rejection of xenogeneic tissues, metabolic or molecular incompatibilities between donor organs and humans, ethical concerns, and the risk of infections that may be transmitted from donor species to humans. Pigs are a promising donor species for xenotransplantation. However, when pig organs are transplanted into primates, hyperacute rejection, acute humoral xenograft rejection, acute cellular xenograft rejection, and chronic xenograft rejection develop. In addition, thrombotic microangiopathy with coagulation dysregulation occurs in xenografts. In order to overcome these xenograft injuries, transgenic pigs with human complement regulatory proteins, ‘anticoagulants,’ ‘antithrombotic’ genes, and knockout for the α1,3-galactosyltransferase gene have been produced. In this article, we discuss the current status and recent progress achieved in the field of xenotransplantation.