Ninomiya H
Division of Hematology, University of Tsukuba.
Rinsho Ketsueki. 1994 Apr;35(4):352-7.
Glycosyl phosphatidylinositol (GPI)-anchored membrane proteins are deficient in the blood cells affected by paroxysmal nocturnal hemoglobinuria (PNH). The relation of the deficiencies of CD59 and CD14 with the clinical features of PNH are reported. CD59 binds to complement components C8 and C9 derived from human sera and inhibits the C5b-9-mediated hemolysis in a species-selective manner. The CD59-binding sites were revealed to be localized in the alpha subunit of C8 and in the "b" domain of C9 (thrombin fragment). The deficiency of CD59 in PNH is causatively related to the hemolytic features in PNH. A monocyte differentiation antigen, CD14, is deficient in the affected PNH monocytes. CD14 is reported to be one of the receptors to lipopolysaccharide (LPS). LPS-binding to the monocytes were revealed to be mediated through CD14 on monocytes. Enhancement of LPS-binding to monocytes by the presence of serum was not seen to PNH-affected monocytes. PNH-affected monocytes showed impaired TNF-alpha production in response to LPS. The deficiency of CD14 indicates the abnormality in PNH-affected monocytes, however, its significance in the clinical features of PNH is to be clarified.
糖基磷脂酰肌醇（GPI）锚定膜蛋白在阵发性夜间血红蛋白尿（PNH）所累及的血细胞中缺乏。本文报道了CD59和CD14缺乏与PNH临床特征的关系。CD59与人血清来源的补体成分C8和C9结合，并以种属选择性方式抑制C5b-9介导的溶血。已发现CD59结合位点位于C8的α亚基和C9（凝血酶片段）的“b”结构域。PNH中CD59的缺乏与PNH的溶血特征存在因果关系。一种单核细胞分化抗原CD14在受累的PNH单核细胞中缺乏。据报道，CD14是脂多糖（LPS）的受体之一。已发现LPS与单核细胞的结合是通过单核细胞上的CD14介导的。在PNH受累的单核细胞中未观察到血清存在时LPS与单核细胞结合的增强。PNH受累的单核细胞对LPS刺激的肿瘤坏死因子-α（TNF-α）产生受损。CD14的缺乏表明PNH受累单核细胞存在异常，然而，其在PNH临床特征中的意义尚待阐明。
