Kojima A, Hazeki K, Seya T
Department of Immunology, Center for Adult Diseases, Osaka, Japan.
Scand J Immunol. 1991 Jun;33(6):707-12. doi: 10.1111/j.1365-3083.1991.tb02544.x.
We have evaluated phagocytosis, C3-binding and cytotoxicity of human leukocytes simultaneously, using IgM-sensitized C3-fragment-bearing sheep erythrocytes (EAC3b, EAC3bi) as targets. In this method, 51Cr-labelled EAC3b or EAC3bi were added to human peripheral granulocytes anchored by fibronectin onto microtitre plate wells. The degrees of haemolysis, binding and ingestion of the target cells were estimated from the radioactivity released. We found that the granulocytes predominantly lysed EAC3bi but not EAC3b or EAC4b. EAC3bi lysis elicited from granulocytes was as effective as that from lymphocytes under the same assay conditions. However, one difference in the cytolysis of the two effector cells was that EAC3bi bound efficiently to all of the granulocytes similarly to EAC3b, whereas it bound to only 4% of the lymphocytes. The bound cells did not appear to be efficiently phagocytosed by the granulocytes. Blocking studies using antibodies suggested that C3bi receptors, CR3 and CR4, but not other C3-binding proteins, C3b/C4b receptor (CR1), membrane cofactor protein (MCP) or decay-accelerating factor (DAF), are involved in granulocyte-mediated haemolysis. We speculate that simultaneous stimulation of the C3bi receptors and the fibronectin receptor results in elicitation of cytotoxicity by granulocytes.
我们使用IgM致敏的携带C3片段的绵羊红细胞（EAC3b、EAC3bi）作为靶标，同时评估了人白细胞的吞噬作用、C3结合能力和细胞毒性。在该方法中，将51Cr标记的EAC3b或EAC3bi添加到通过纤连蛋白锚定在微量滴定板孔上的人外周血粒细胞中。根据释放的放射性估计靶细胞的溶血、结合和摄取程度。我们发现粒细胞主要裂解EAC3bi，而不裂解EAC3b或EAC4b。在相同的检测条件下，粒细胞引起的EAC3bi裂解与淋巴细胞引起的同样有效。然而，两种效应细胞在细胞溶解方面的一个差异是，EAC3bi与所有粒细胞的结合效率与EAC3b相似，而它仅与4%的淋巴细胞结合。结合的细胞似乎没有被粒细胞有效地吞噬。使用抗体的阻断研究表明，C3bi受体CR3和CR4，而非其他C3结合蛋白、C3b/C4b受体（CR1）、膜辅助蛋白（MCP）或衰变加速因子（DAF），参与粒细胞介导的溶血。我们推测，C3bi受体和纤连蛋白受体的同时刺激导致粒细胞引发细胞毒性。
