Induction of immunotolerance using non-myeloablating stem cell transtplantation in swine model of small intestinal transplantation

近10年来，小肠移植后的存活率逐渐提高。然而，急性和慢性排斥反应的发生率仍然很高，有时还会发生晚期移植物丢失。为了克服免疫障碍，需要诱导耐受。非清髓干细胞移植已被引入作为白血病的治疗工具。在活体相关器官移植中，这种方法可以诱导供者特异性耐受。在干细胞移植诱导耐受后，同一供者的小肠移植可以在没有免疫抑制的情况下被接受。我们已经开始利用小型猪的小肠移植模型来建立这种方法。第一年，我们建立了小型猪的小肠移植手术技术。回肠移植采用带蒂回肠移植。各肠系膜上血管的切断点均为腹主干和门静脉的根部。移植血管与主动脉吻合，移植静脉与下腔静脉端侧吻合，第二年开始非清髓干细胞移植。取自髂骨的骨髓细胞。然而，干细胞移植所需的细胞数量还不够。然后我们开始用两根针冲洗骨髓。在此之后，细胞数量增加。在第三年，小型猪，SLA建立的同源克隆，不能由动物养殖场供应。特别是，SLA 1不匹配的组合现在是不可能的。我们提出了可以建立非清髓原胆固醇的化疗原胆固醇。

Survival rate after Small intestinal transplantation has been improved gradually in recent 10 years. However, incidence of acute as well as chronic rejection is still high, and late graft loss is sometimes happen. In order to overcome immunological obstacles, induction of tolerance is called for.Non-myeloablating stem cell transplantation has been introduced as treatment tool for leukemia. In living-related organ transplantation, donor specific tolerance can be induced by this method. After tolerance induction by stem cell transplantation, small intestinal graft from the same donor can be accepted without immunosuppression. We have starting to establish this method using mini-swine model of small intestinal transplantation.In the first year, operion technique of small intestinal transplantation, using miniature swine was established. Ileal graft was harvested with pedicle. Cutting site of each superior mesenteric vessel was radix of celiac trunks and portal vein. Then graft was anastosed to Aorta and graft vein was anastomosed to IVC by end-to-side fashion.In the second year, non-myeloablating stem cell transplantation was started. Bone marrow cells were harvested from iliac bone. However the number of cells were not enough for tstem cell transplantation. Then we started irrigation of bone marrow, using two needle. After that the number of cells were increased. The numbers were identified by CD34 immunostaining.In the third year, miniature swine, SLA established syngenic chrone, cannot be supplied by animal farm. Especially, combination of SLA 1 mismatch is impossible now. We have proposed the protochol of chemotherapy which can establish the non-myelloablating protochol.