枯草芽孢杆菌表面展示虹彩病毒SGIV抗原蛋白及其诱导石斑鱼肠道黏膜免疫研究

新加坡石斑鱼虹彩病毒（SGIV）是石斑鱼等主要海水养殖鱼类的重要病毒性病原，危害极大。然而到目前为止，尚无便捷、有效且易于大规模应用的防控该病毒病爆发的疫苗。本项目拟在前期自主分离石斑鱼肠道益生菌等研究基础上开展口服疫苗研究，包括：1）通过构建工程菌将SGIV主要结构蛋白VP072、VP088及VP039展示到枯草芽孢杆菌表面，以口服疫苗形式免疫石斑鱼，确定口服疫苗的免疫保护力和保护期；2）探究口服疫苗免疫后，IgM和IgT及其阳性细胞在石斑鱼肠道黏膜免疫组织的分布、迁移、动态变化和生物学特性；3）研究口服疫苗在肠道内的分布、剂量、增殖规律及其对肠道微生态及黏膜免疫应答的调控。研究结果将有助于深层次揭示口服疫苗诱导的肠道黏膜免疫应答机制，为开发虹彩病毒口服疫苗提供理论依据。

Singapore grouper iridovirus (SGIV) is a major pathogen resulting in heavily economic losses to grouper aquaculture. However, up to now, there is no convenient, effective and large-scale vaccine to prevent and control the outbreak of the virus. This project plans to carry out the oral vaccine research on the basis of the early research on isolation of intestinal probiotics of grouper. The contents include: 1) To construct Bacillus subtilis which displayed the main capsid protein VP072, envelope proteins vp088 and vp039 of SGIV; Oral immunization of grouper and determine the host's immune protection effect and protection period. 2) To explore the distribution, migration, dynamic changes and biological characteristics of IgM, IGT and their positive cells in intestinal mucosa mmune tissues of grouper. 3) Effect of distribution, dose and proliferation of live vaccine on intestinal microecology and mucosal immune response. The research will help to clarify the mechanism of intestinal mucosal immune response induced by oral vaccine and provide theoretical basis for the development of oral iridovirus vaccine.