Magnadottir Bergljot, Gudmundsdottir Sigridur, Gudmundsdottir Bjarnheidur K, Helgason Sigurdur
Institute for Experimental Pathology, University of Iceland, Keldur v. Vesturlandsveg, IS-112 Reykjavik, Iceland.
Comp Biochem Physiol B Biochem Mol Biol. 2009 Nov;154(3):309-16. doi: 10.1016/j.cbpb.2009.07.005. Epub 2009 Jul 22.
Natural antibodies are present in the serum of vertebrates regardless of antigenic stimulation. Characteristic activity is commonly detected against haptenated proteins, single stranded DNA and thyroglobulin. Natural antibodies are believed to provide an instant protection against pathogens of a broad specificity and to participate in homeostasis. Cod is a poor antibody responder but shows a relatively high level of natural antibodies against haptenated proteins. In this project the specificity, activity and affinity of natural antibodies was studied in different groups of cod and the effects of age/size, environmental temperature, immunisation and infection examined. Antigen driven selection of natural antibodies was also studied in one group of cod. The results demonstrated a broad and yet characteristic specificity, primarily directed against haptenated proteins and possible food antigens. The antibody activity increased with increasing age and at higher temperature whereas immunostimulation by immunisation or infection resulted in variable response. The affinity index of natural antibodies of cod generally did not correlate with changes in the antibody activity but it was in the same range as the affinity index of acquired cod antibodies and that of some mammalian monoclonal acquired antibodies. Analysis of antigen driven antibody selection showed that the natural antibody repertoire of individual cod was heterogeneous with respect to its affinity for haptenated protein.
天然抗体存在于脊椎动物的血清中，与抗原刺激无关。通常可检测到针对半抗原化蛋白、单链DNA和甲状腺球蛋白的特征性活性。天然抗体被认为可提供针对多种特异性病原体的即时保护，并参与体内稳态。鳕鱼是一种较差的抗体应答者，但对半抗原化蛋白显示出相对较高水平的天然抗体。在本项目中，研究了不同鳕鱼群体中天然抗体的特异性、活性和亲和力，并考察了年龄/大小、环境温度、免疫接种和感染的影响。还在一组鳕鱼中研究了天然抗体的抗原驱动选择。结果表明，天然抗体具有广泛且独特的特异性，主要针对半抗原化蛋白和可能的食物抗原。抗体活性随年龄增长和温度升高而增加，而免疫接种或感染引起的免疫刺激导致反应各异。鳕鱼天然抗体的亲和力指数通常与抗体活性的变化无关，但与获得性鳕鱼抗体以及一些哺乳动物单克隆获得性抗体的亲和力指数处于同一范围。对抗原驱动的抗体选择分析表明，个体鳕鱼的天然抗体库在对半抗原化蛋白的亲和力方面是异质的。
