猪红细胞表面抗原化学修饰后应用于异种输血的初步体外研究

Chemical modification of antigens on porcine red blood cells:the preliminary study on xenotransfusion

目的使化学修饰的猪红细胞(pRBC)呈现出与人红细胞(hRBC)相似的血清学特性,减弱或消除人体对pRBC的免疫排斥。方法采用双修饰法即rSα-GalE酶解法(100U/mL的rSα-GalE处理)修饰改造pRBC表面的Gal抗原,再用mPEG包裹法(3mmol/L的mPEG-BTC)修饰遮蔽pRBC的non-αGal表面抗原。结果修饰后的pRBC与人混合血浆的盐水交叉配血试验为阴性;修饰后pRBC的结构、功能等指标基本正常。结论经rSα-GalE和mPEG双修饰法修饰改造的pRBC呈现出与hRBC相似的血清学特性。

Objective Recent findings indicate that the serological and biochemical characteristics ot porcine erythrocytes share many similarities with human red blood cell （hRBC）. Scientists believed that humanized porcine red blood cells （pRBC） could be used as one alternative source for human blood transfusion, Methods In order to eliminate aGal antigen and non-aGal on the surface of pRBC, recombinant soybean α-Galactosidase （rSa-GalE） constructed by our lab was used to remove terminal αGal residues from aGal antigen, and mPEG-BTC was used to camouflage non-aGal xenoantigen on the surface of pRBC, Results The carbohydrate structures of aGal xenoantigen of pRBC treated with rSα-GalE were completely modified. The antigenic determinants of αGal and non-αGal xenoantigen on the surface of pRBC were successfully camouflaged through mPEG-BTC modification, But this modification needed higher concentration of mPEG-BTC which could cause slight structure damage, Considering this, with combination of αGal xenoantigen conversion by rSa-GalE and chemical camouflage of non-αGal xenoantigen with lower concentration of mPEG-BTC, the antigenic determinants of pRBC were attenuated and hemagglutination were diminished, Conclusion The morphology, structures, functions and deformability of pRBC modified with rSα-GalE, mPEG-BTC and rSα- GalE＋ mPEG-BTC were normal.