Bakács T, Ringwald G, Tusnády G, Végh Z, Klein E
Dept. Immunol., National Institute of Oncology, Budapest, Hungary.
J Clin Lab Immunol. 1990 Aug;32(4):167-75.
Lysis of group A and B erythrocytes by human complement was studied using 9 anti-A (IgM) and 10 anti-B (IgM) monoclonal antibodies in direct and cold target competition 51Cr-release assays. The relative concentration of membrane-bound immunoglobulins was detected by indirect immunofluorescence in flow cytometric analysis. The number of binding sites/cell and affinity of the monoclonal antibodies was measured in ELISA assays. Complete haemolysis was obtained at 2 micrograms.ml-1 antibody concentrations with the majority of reagents when only a small proportion of the antibody binding sites were occupied. The influence of membrane-bound antibody on complement binding was examined by the complement consumption capacity of sensitized erythrocytes at supra-haemolytic antibody concentration. We found that complement consumption correlated with the amount of membrane-bound immunoglobulins. To obtain equal level of target and competitor cell lysis group B erythrocytes had to be equipped with higher amounts of antibodies than group A erythrocytes. The different lytic activity of IgM anti-A and anti-B monoclonal antibodies could not be accounted for merely by differences in their surface density.
利用9种抗A（IgM）和10种抗B（IgM）单克隆抗体，通过直接和冷靶竞争51Cr释放试验研究了人补体对A组和B组红细胞的溶解作用。通过流式细胞术分析中的间接免疫荧光检测膜结合免疫球蛋白的相对浓度。在ELISA试验中测量单克隆抗体的结合位点/细胞数量和亲和力。当仅一小部分抗体结合位点被占据时，大多数试剂在抗体浓度为2微克/毫升时可实现完全溶血。通过超溶血抗体浓度下致敏红细胞的补体消耗能力，研究了膜结合抗体对补体结合的影响。我们发现补体消耗与膜结合免疫球蛋白的量相关。为了获得相同水平的靶细胞和竞争细胞溶解，B组红细胞必须比A组红细胞配备更多的抗体。IgM抗A和抗B单克隆抗体的不同溶解活性不能仅仅用它们的表面密度差异来解释。
