Humanized endothelium in gene edited ETV2 null pig embryos as a platform for exogenic organ production and xenotransplantation. Sus scrofa

Whole organ transplantation remains limited by the scarcity of donor organs. Xenotransplantation, using the pig as a donor, may provide an unlimited number of transplantable organs for patients having chronic end-stage diseases. One of the challenges associated with xenotransplantation, however, is organ rejection initiated by donor endothelial cells. Therefore, we pursued a novel strategy, to generate pigs with humanized endothelial cells with the goal of providing a universal platform for exogenic organ production by reducing immunological rejection. We used gene editing and somatic cell nuclear transfer (SCNT) technologies to engineer ETV2 mutant porcine embryos, which lacked endothelial and hematopoietic lineages and were embryonically lethal. To rescue these ETV2 porcine mutants, we undertook complementation experiments using GFP-labeled wildtype porcine blastomeres. These derived chimeric embryos were viable and all hematoendothelial lineages were populated by the donor-derived cells. Using embryo complementation strategies together with hiPSCs, we demonstrate survival and proliferation of the chimeric embryos in vitro and the engraftment of hiPSCs and BCL2 overexpressing hiPSCs into the ETV2 mutant embryos in vivo.