半滑舌鳎IgT在皮肤粘膜中的抗菌作用和机制研究

半滑舌鳎是我国特有的海水养殖珍贵品种。近年来皮肤溃疡病频繁暴发，成为限制产业发展的首要问题。皮肤粘膜组织是阻止病原进入体内的第一道防线，从皮肤中寻找抗病关键基因是一种非常有效的策略。IgT是一种新型的、硬骨鱼类特有的免疫球蛋白。目前对IgT的研究仅限于游动性鱼类，且局限于肠粘膜免疫。本项目拟在率先破译半滑舌鳎IgT和pIgR基因的基础上，开展以下研究：1）解析半滑舌鳎皮肤粘膜中IgT的蛋白结构、转运模式和表达特性，明确IgT+淋巴细胞的发育过程及在皮肤中的定位和活化特征；2）利用基因组编辑和RNA干扰等技术构建个体模型和细胞模型，检测皮肤粘膜IgT的抗菌作用及抗菌相关基因的表达模式，分析IgT对补体信号通路等抗病相关信号通路的调控作用。本项目的研究成果将阐明半滑舌鳎IgT在皮肤粘膜中的免疫功能和信号调控通路，能够为鱼类皮肤疾病的防控、抗病品系的选育和疫苗的研发提供新的实验依据。

Half-smooth tongue sole (Cynoglossus semilaevis) is one of the endemic flatfish in China. However, cultured half-smooth tongue sole has been severely threatened by the skin ulceration disease, which became the main trouble in aquaculture. Skin is the main mucosal surface and the first immune barrier, so it is an effective strategy to find key genes for disease resistance from the skin. IgT is a new and special Ig isotype in teleost, however, the research limited in movable teleost and their intestinal mucosal immunity. Based on firstly decoding the gene sequences of IgT and pIgR, we will conduct the systematic research on the underlying list: 1) Identification of the characteristics of IgT in protein structure, the transport motif of IgT from skin to mucosa, and the expression profiles under normal and bacterial infected conditions. 2) Exploration the function of IgT on killing of antigen, and activating of anti-pathogen pathway both in animal and cell models, which will be constructed by genome edit and RNAi. Our project will explain the important function and signal pathway of IgT in the skin mucosal immunity of benthic fish (half-smooth tongue sole), and provide theoretical basis and technical supports for skin ulceration disease prevention, resistance breeding, and vaccine development in aquaculture.