Parker C J, Stone O L, Bernshaw N J
Department of Medicine, University of Utah Medical Center, Salt Lake City.
J Immunol. 1989 Jan 1;142(1):208-16.
When whole serum C is activated by cobra venom factor complexes (CoFBb), paroxysmal nocturnal hemoglobinuria (PNH) III E (the most C-sensitive type) are hemolyzed, but normal and PNH II E (the intermediately sensitive type) are not. Previous studies have shown that after exposure to CoFBb and serum, PNH III E bind relatively large amounts of the trimolecular C complex, C5b67, whereas normal and PNH II E bind virtually none. In the studies reported herein, we have observed that when normal and PNH III E are incubated with isolated C5, C6, and 125I-C7 in the presence CoFBb, the normal E bind more C5b-7 than the PNH cells. When C7-deficient serum is included in the reaction mixture, however, the PNH E are once again observed to bind much greater amounts of C5b-7. These observations suggest that plasma and membrane factors act in concert to restrict the assembly of the trimolecular C5b-7 complex on human E. PNH III E appear to be deficient in the membrane component of this inhibitory system.
当全血清C被眼镜蛇毒因子复合物（CoFBb）激活时，阵发性夜间血红蛋白尿（PNH）III E型（对C最敏感的类型）会发生溶血，但正常细胞和PNH II E型（中度敏感类型）则不会。先前的研究表明，在暴露于CoFBb和血清后，PNH III E型会结合相对大量的三分子C复合物C5b67，而正常细胞和PNH II E型几乎不结合。在本文报道的研究中，我们观察到，当正常细胞和PNH III E型在CoFBb存在的情况下与分离的C5、C6和125I-C7一起孵育时，正常E型细胞比PNH细胞结合更多的C5b-7。然而，当反应混合物中包含C7缺陷血清时，再次观察到PNH E型细胞结合大量更多的C5b-7。这些观察结果表明，血浆和膜因子共同作用以限制三分子C5b-7复合物在人红细胞上的组装。PNH III E型细胞似乎在这种抑制系统的膜成分上存在缺陷。
