Mochida K, Lou Y H, Hara A, Yamauchi K
Department of Biology, Faculty of Fisheries, Hokkaido University, Hakodate, Japan.
Immunology. 1994 Dec;83(4):675-80.
Teleost fish are able to produce IgM class antibody, as are other vertebrates. When the teleost fish Oreochromis niloticus was immunized with bovine serum albumin (BSA), it produced antibody to BSA with an average avidity of 7.4 x 10(8)/M. Thus, dissociation of antigen-antibody complexes only occurred at conditions of < pH 2.5, > pH 11, > 4M NaI or > 4M urea, demonstrating high stability of the complex. Western blot analyses further showed the high specificity of the antibody to BSA. In contrast to mammals, when the fish was challenged with multiple protein antigens, it produced antibody only to the major component but not to others. The antibody generated to a specific antigen accounted for up to 1.1% of whole serum protein or 7.0% of whole immunoglobulin. We conclude (1) the systemic antibody response in teleost fish may be an 'all or nothing' response, which is different from that in mammals; (2) the quality (specificity and affinity) of the antibody produced is similar to that of mammals. The findings not only reveal a quite different strategy of immune response in fish, but also raise the possibility of technical application.
硬骨鱼能够产生IgM类抗体，其他脊椎动物也能。当用牛血清白蛋白（BSA）免疫硬骨鱼尼罗罗非鱼时，它产生了针对BSA的抗体，平均亲和力为7.4×10⁸/M。因此，抗原-抗体复合物仅在pH<2.5、pH>11、NaI>4M或尿素>4M的条件下才会解离，这表明复合物具有很高的稳定性。蛋白质印迹分析进一步表明该抗体对BSA具有高度特异性。与哺乳动物不同，当用多种蛋白质抗原攻击该鱼时，它只产生针对主要成分的抗体，而不产生针对其他成分的抗体。针对特定抗原产生的抗体占全血清蛋白的1.1%或全免疫球蛋白的7.0%。我们得出结论：（1）硬骨鱼的全身性抗体反应可能是一种“全或无”的反应，这与哺乳动物不同；（2）所产生抗体的质量（特异性和亲和力）与哺乳动物相似。这些发现不仅揭示了鱼类免疫反应的一种截然不同的策略，也提高了技术应用的可能性。
