体外转运红细胞囊泡的GPI锚定蛋白CD59保护阵发性睡眠性血红蛋白尿症红细胞<英文>

Protection of Paroxysmal Nocturnal Hemoglobinuria Erythrocytes by Transferring of GPI-Anchored Protein CD59 from Vesicles of Erythrocytes In Vitro

阵发性睡眠性血红蛋白尿症(PNH)是一种后天获得性克隆溶血疾病,由于血细胞膜上缺乏具有调节蛋白补体的GPI-锚定蛋白如CD59和CD55等,所以对补体敏感,易产生溶血。红细胞存储或ATP耗空时有囊泡释放,经免疫印迹试验证明囊泡中富含CD59。应用免疫亲和层析柱分离PNH CD59^-红细胞,然后与红细胞囊泡保温,保温后分别测定PNH CD59^-细胞表面CD59含量和溶血度。用流式细胞仪测定CD59,结果发现保温后CD59含量增加;用蛇毒因子溶血试验测得溶血度有显著下降。体外实验证明囊泡上的CD59可以转运到PNH CD59^-红细胞上,并具有抑制补体溶血的功能,使PNH CD59^-红细胞在受补体攻击时不易溶血。

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hemolytic disease characterized by sensitivity of erythrocytes to complement owing to deficiency of glycosylphosphatidylinositol (GPI)- anchored complement regulatory proteins, such as CD55 and CD59. Vesicles released from normal erythrocytes under storage or ATP depleted, are rich in CD59. PNH CD59- cells wwere separated by immuno-affinity column bound with monoclonal antibody CD59, and then incubated with normal erythrocyte vesicles. The content of CD59 and hemolysis of PNH CD59- cells were detected by flow cytometric analysis and cobra venom factor hemolytic test respectively. The fluorescence intensity of PNH CD59- cells was increased and the hemolysis was sighnificantly decreased. It seems that CD59 protein molecules might transfer from normal erythrocyte vesicles to PNH CD59- cells and retain the complement regulatory function. CD59-erythrocytes could be rendered less liable to hemolyze during complement attack.