Margni R A, Perdigón G, Abatángelo C, Gentile T, Binaghi R A
Immunology. 1980 Nov;41(3):681-6.
Complement fixing capacity, antibody-dependent cell cytotoxicity and in vivo opsonic function of rabbit anti-DNP precipitating and co-precipitating antibodies were analysed. Precipitating antibody activated the complement system, but co-precipitating antibody did not. Both antibody preparations behaved similarly in antibody-dependent cytotoxicity reactions. When chicken erythrocytes were employed as target cells, both antibodies were inactive with homologous (rabbit) lymphocytes as effector cells but were active with heterologous lymphoid effector cells (human, guinea-pig). Clearance of antigen from the blood of mice was accelerated following injection of an optimal dose of precipitating antibody but co-precipitating antibody was ineffective even at different doses. Competition between precipitating and co-precipitating antibodies in complement fixation and antigen elimination following interaction with antigen successively or at the same time was investigated. In these tests, both antibodies competed with antigen by mass but not by affinity. The possibility exists that co-precipitating antibody has one high and one low affinity binding site and thus acts as an univalent blocking antibody and is therefore not able to form active complexes with antigen. The possible role of co-precipitating antibody in some humoral and cellular immune mechanisms is discussed.
分析了兔抗二硝基苯沉淀抗体和共沉淀抗体的补体结合能力、抗体依赖性细胞毒性及体内调理功能。沉淀抗体激活补体系统，但共沉淀抗体未激活。两种抗体制剂在抗体依赖性细胞毒性反应中的表现相似。当用鸡红细胞作为靶细胞时，两种抗体对同源（兔）淋巴细胞作为效应细胞均无活性，但对异源淋巴效应细胞（人、豚鼠）有活性。注射最佳剂量的沉淀抗体后，小鼠血液中抗原的清除加速，但共沉淀抗体即使在不同剂量下也无效。研究了沉淀抗体和共沉淀抗体在与抗原先后或同时相互作用后在补体结合和抗原清除中的竞争情况。在这些试验中，两种抗体均按质量而非亲和力与抗原竞争。存在这样一种可能性，即共沉淀抗体具有一个高亲和力结合位点和一个低亲和力结合位点，因此作为单价阻断抗体，故而不能与抗原形成活性复合物。文中讨论了共沉淀抗体在某些体液和细胞免疫机制中的可能作用。
