Fletcher A, Bryant J A, Gardner B, Judson P A, Spring F A, Parsons S F, Mallinson G, Anstee D J
Australian Red Cross Society, New South Wales Division, Blood Transfusion Service, Sydney.
Immunology. 1992 Mar;75(3):507-12.
CD59 is a widely expressed cell surface glycosylphosphatidylinositol (GPI)-linked glycoprotein which acts as an inhibitor of the assembly of the membrane attack complex of autologous complement. Four new monoclonal antibodies to CD59 (2/24, 1B2, BRIC 229, BRIC 257) are described. Competitive binding experiments using these antibodies, two known CD59 antibodies (MEM-43, YTH 53.1) and a previously described antibody LICR-LON-Fib75.1 demonstrated that all seven antibodies see related epitopes on human erythrocyte CD59. In common with other GPI-linked proteins, CD59 (as defined by antibody 2/24) was sensitive to treatment with phosphatidylinositol-specific phospholipase C (PI-PLC) on lymphocytes and monocytes but not on erythrocytes. Flow cytometric analysis using antibody 2/24 identified two populations (CD59 positive and CD59 deficient) of lymphocytes, monocytes and erythrocytes in peripheral blood from a patient with paroxysmal nocturnal haemoglobinuria (PNH). The abundance of CD59 on normal erythrocytes was determined as 21,000 copies/cell when radioiodinated BRIC 229 was used. Other CD59 antibodies gave values of 10,000 (IF5) and 15,000 (2/24) against the same target cells. Radioiodinated Fab fragments of BRIC 229 gave a value of 39,000 copies/cell. Erythrocytes from two individuals with a rare inherited deficiency of decay accelerating factor (DAF), known as the Inab phenotype, expressed normal levels of CD59.
CD59是一种广泛表达的细胞表面糖基磷脂酰肌醇（GPI）连接糖蛋白，可作为自身补体膜攻击复合物组装的抑制剂。本文描述了四种针对CD59的新型单克隆抗体（2/24、1B2、BRIC 229、BRIC 257）。使用这些抗体、两种已知的CD59抗体（MEM-43、YTH 53.1）和先前描述的抗体LICR-LON-Fib75.1进行的竞争性结合实验表明，所有七种抗体识别的是人类红细胞CD59上的相关表位。与其他GPI连接蛋白一样，CD59（由抗体2/24定义）对淋巴细胞和单核细胞用磷脂酰肌醇特异性磷脂酶C（PI-PLC）处理敏感，但对红细胞不敏感。使用抗体2/24进行的流式细胞术分析在一名阵发性夜间血红蛋白尿（PNH）患者的外周血中鉴定出淋巴细胞、单核细胞和红细胞的两个群体（CD59阳性和CD59缺陷）。当使用放射性碘化的BRIC 229时，正常红细胞上CD59的丰度测定为21,000个拷贝/细胞。针对相同靶细胞，其他CD59抗体给出的值为10,000（IF5）和15,000（2/24）。BRIC 229的放射性碘化Fab片段给出的值为39,000个拷贝/细胞。两名患有罕见遗传性衰变加速因子（DAF）缺乏症（称为Inab表型）的个体的红细胞表达正常水平的CD59。
