去除αGal抗原的猪红细胞输入猕猴体内的初步研究

Transfusion ofα-galactosidase treated porcine red blood cells to rhesus monkey

目的探讨经α-半乳糖苷酶(AGL)去除了αGal抗原的猪红细胞输注给灵长类动物的可能性。方法使用AGL体外去除猪红细胞表面的αGal抗原,应用流式细胞术和配血试验检测修饰效果:用FITC标记此红细胞,将AGL酶解的pRBCs与未酶解的pRBCs分别输注给使用免疫抑制剂(眼镜蛇毒因子及地塞米松)预注射的猕猴;流式细胞仪检测计算输注红细胞在猕猴体内的存活率,同时检测受试猕猴的血生化及尿液指标。结果AGL有效清除了猪红细胞表面的αGal抗原,使其与猕猴血清的凝集反应减弱。未酶解的pRBCs在猕猴体内存活<0.5h。AGL酶解后的猪红细胞输注后2h在猕猴体内有29%存活,8h猕猴体内仍可检测到荧光标记的pRBCs。结论AGL能有效清除猪细胞表面的αGal抗原,减弱HAR,延长异种移植物的存活时间。

Objective： To investigate the possibility of transfusing alpha-galactosidase-treated pig red blood cells （pRBCs） to rhesus monkeys. Methods： pRBCs were treated in vitro with recombinant alpha-galactosidase （rc-AGL）. The effect of the treatment was measured by flow cytometry and cross-matching pRBC and rhesus monkey sera. The red blood cells were labeled by FITC in vitro before transfusion. The survival rates of alpha-galactosidase-treated pRBCs and unmodified pRBCs were measured by flow cytometry. Rhesus monkeys were treated with immunosuppressants （cobra venom factor and Dexamethasone） before transfusion. Blood and urine biochemical analysis of transfusion receipts were measuredo Results： AGL could effectively remove α-Gal xenoantigen on pRBC membrane and reduce the hemagglutination. Flow cytometry data showed that the survival time of unmodified pRBCs was less than 30 minutes and the survival rate of AGL-treated pRBCs was 29% at 2h after transfusion. The modified pRBCs were detectable in rhesus monkey blood at 8h after transfusion. Conclusion： These results suggest that the transfusion of AGL-treated pRBCs could prevent the hyperacute rejection mediated by natural antibodies and prolong the survival time of xenograft.