Ralph P, Nakoinz I, Diamond B, Yelton D
J Immunol. 1980 Nov;125(5):1885-8.
Antibody-dependent phagocytosis and lysis of sheep RBC by mouse peritoneal exudate cells were studied using IgG subclass fractions of sera prepared by protein A-Sepharose chromatography. Three IgG1, 3 IgG2a, 4 IgG2b, and 1 IgG3 hybridoma antibodies to RBC were also used. The results showed that some monoclonal IgG2a and IgG2b antibodies were more active than IgG1 or IgG3 preparations when normalized to hemagglutinating activity, but all IgG sources mediated both effector mechanisms. This is in accord with findings of strong Fc receptors on macrophages for the IgG2 isotypes and weaker binding by IgG1 and newly discovered IgG3 receptors. A monoclonal IgG2b with no hemagglutination titer showed normal cooperation with macrophages. In contrast, 2 hybridoma IgM were inactive in macrophage-mediated lysis and allowed only marginal ingestion. Similar results were obtained using several macrophage cell lines, mouse spleen and human peripheral blood mononuclear cells, showing that all these types of effector cells do not distinguish among (mouse) IgG subclasses in handling antibody-coated RBC.
利用蛋白A-琼脂糖凝胶层析法制备的血清IgG亚类组分，研究了小鼠腹腔渗出细胞对绵羊红细胞的抗体依赖性吞噬作用和裂解作用。还使用了三种针对红细胞的IgG1、三种IgG2a、四种IgG2b和一种IgG3杂交瘤抗体。结果显示，当以血凝活性标准化时，一些单克隆IgG2a和IgG2b抗体比IgG1或IgG3制剂更具活性，但所有IgG来源均介导两种效应机制。这与巨噬细胞上存在针对IgG2同种型的强Fc受体以及IgG1和新发现的IgG3受体结合较弱的研究结果一致。一种无血凝效价的单克隆IgG2b与巨噬细胞表现出正常的协同作用。相比之下，两种杂交瘤IgM在巨噬细胞介导的裂解中无活性，仅允许少量摄取。使用几种巨噬细胞系、小鼠脾脏和人外周血单个核细胞也获得了类似结果，表明所有这些类型的效应细胞在处理抗体包被的红细胞时不会区分（小鼠）IgG亚类。
