IgT是近年来发现的硬骨鱼所特有的一种新型免疫球蛋白，在硬骨鱼黏膜免疫应答中发挥重要功能。目前对鱼类IgT研究多集中在基因克隆上，对其生化特性和黏膜免疫功能及基因结构、抗体库多样性等方面的研究还很不充分。因此，本课题以鲤鱼为研究对象，在前期克隆得到一种新型鲤鱼IgT基因的基础上，制备抗鲤鱼IgT单克隆抗体，利用免疫组学、流式细胞技术及免疫印迹技术等，对鲤鱼IgT生化特性、与细菌结合能力、IgT+ B细胞等进行分析研究。在此基础上，利用BAC文库筛选技术对IgT重链基因座结构进行研究，弄清重链V、D、J、C等基因的数目及排列方式，并利用高通量测序技术分析鲤鱼IgT抗体库的多样性，探讨鲤鱼IgT在黏膜免疫中是否发挥着类似于哺乳动物IgA那样专一性黏膜抗体的功能。本研究为深入了解脊椎动物免疫球蛋白的进化及鱼类黏膜免疫机制提供基础资料，同时，也为利用鱼类黏膜免疫应答特性进行疾病防治提供理论依据。

IgT is a new type of immunoglobulin reported in bony fish in recent years, which plays an important role in the mucosal immune response of fish. At present, most of the studies on IgT focused on gene cloning and identification, but its biochemical characteristics, mucosal immune mechanism, gene structure and diversity of antibody repertoire in mucosal immune tissues have not been well studied. Therefore, this project, based on a novel IgT gene previouslycloned and identified in common carp, intends to prepare anti-IgT monoclonal antibody and study the IgT biochemical characteristics, bacterial binding ability andI gT+ B cells using immune histochemistry, flow cytometry and western blotting. On this basis, IgT heavy chain locus will be investigated by screening bacterial artificial chromosome (BAC) library, to determine the number and arrangement of V, D, J and C genes in IgT heavy chain. Furthermore, high-throughput sequencing will be performed to analyze the diversity of IgT antibody repertoire in mucosal immune tissues and systemic immune tissues of common carp, and explore whether the fuction of this novel immunoglobulin IgT from carp in mucosal immunity is similar to that of mammalian mucosa specific antibody IgA.. This study provides basic information for further understanding the evolution of immunoglobulin in vertebrates and the mechanism of mucosal specific immunity of common carp, and suggests theoretical basis for the prevention and treatment of disease in fish through mucosal immune response.