Development of the new strategy in ABO blood group incompatible transplantation

ABO血型不合的实体器官移植的主要障碍是急性体液排斥反应，导致移植物功能障碍。与ABO血型不合相关的体液排斥反应，移植是由与供体器官内皮细胞结合的抗供者A/B血型抗体触发的。我们试图开发新的中和血型抗原的方法来克服ABO血型不合的移植，这些方法是通过(1)RNA干扰或(2)糖苷酶进行的。(1)首先，为ABO血型基因创建小干扰RNA。将该小干扰RNA导入表达A、B抗原的肿瘤细胞系SW620、LoVo和SW48，实时定量RT-PCR检测到ABO血型基因的信使RNA减少了70-80%。α-N-乙酰半乳糖苷酶不能完全降解A型血型抗原。另一方面，用α-半乳糖苷酶降解B抗原，将B组红细胞转化为B组红细胞，用流式细胞仪进行检测。将与α-半乳糖苷酶反应的AB组红细胞转化为A组红细胞。用α-半乳糖苷酶将含有A、B抗原的癌细胞株SW48转化为只含有A抗原的细胞，成功地用糖苷酶中和了B血型抗原。

The major barrier to ABO-incompatible solid organ transplantation is the acute humoral rejection, leading to graft dysfunction. Humoral rejection associated with ABO-incompatible, transplantation is triggered by antidonor blood group A/B antibodies that bind to the endothelium of the donor's organ.We tried to develop the new methods of neutralizing the blood group antigen to overcome ABO-incompatible transplantation, which were performed by (1) RNA interference or (2) glycosidases.(1) Firstly, small interference RNA for the ABO blood group gene was created. When the cancer cell lines SW620, LoVo, and SW48 which express A or B antigen were transfected with the small interference RNA, the messenger RNA of the ABO blood group gene were reduced by 70-80%, detected by real time RT-PCR. However, expression of the ABO blood group antigen was not suppressed by small interference RNA, detected by flow cytometry and westernblotting.(2) Blood group A antigen was not completely degraded by α-N-acetylgalactosaminidase. On the other hand, B antigen was degraded by α-galactosidase, and group B RBCs were converted to group B RBCs, which were detected by flow cytometry. The group AB RBCs reacted with α-galactosidase were converted to group A RBCs. The cancer cell line SW48 which have A and B antigens were also converted to the cells with only A antigens by α-galactosidase.We succeeded in neutralizing the blood group B antigen by glycosidase.