鸡β-半乳糖凝集素蛋白-1在新城疫病毒感染中的作用及其分子机制

新城疫病毒（NDV）是严重危害家禽养殖业的病原体，而宿主因子在NDV感染中的作用知之甚少。β-半乳糖凝集素蛋白-1（Galectin-1）是一种免疫调控分子，并能与病毒糖蛋白结合从而影响其感染细胞的进程，禽Galectin-1在病毒感染中的作用尚未有报道。本项目选择NDV感染后上调表达的chicken Galectin-1B（CG-1B）为研究对象，探索CG-1B在NDV感染中的作用机制。通过体外表达获得CG-1B，检测其对NDV血凝活性的影响。建立ELISA检测CG-1B与NDV之间的直接结合。通过蛋白相互作用筛选与CG-1B相互作用的NDV蛋白，利用反向遗传构建突变NDV，确定与CG-1B相互作用的位点。检测CG-1B对NDV复制的影响，揭示细胞外CG-1B在NDV吸附细胞进程中、细胞内CG-1B在NDV蛋白成熟运输进程中的作用，从而阐明CG-1B在NDV感染中的作用及其分子机制。

Newcastle disease virus (NDV) is an important pathogen which causes significant economic losses to the poultry industry, the contributions of host factors during the course of NDV infection remain largely unknown. Galectin-1 has been extensively reported as an important immune regulation factor, in recent years, it has become clear that galectin-1 could also bind the envelope glycoprotein of viruses to influence the process of virus infection. However, the roles of chicken Galectin-1 in the course of virus infection have not been reported. In this study, we explore the potential roles of chicken Galectin-1B（CG-1B）during NDV infection, which was up-regulated in NDV- infected chickens. The CG-1B recombinant protein will be expressed in vitro and purified, the impact of CG-1B on NDV hemagglutination activity will be further detected. An ELISA based method will be developed to demonstrate the direct binding between CG-1B and NDV virion. Furthermore, protein interaction methods would be applied to identify the NDV proteins which interact with CG-1B, mutant NDVs will be constructed through reverse genetics to determine the specific sites on NDV proteins that bind to CG-1B. The impacts of extracellular and intracellular CG-1B on NDV replication will be determined, and the mechanism of extracellular CG-1B in the course of NDV adsorption and intracellular CG-1B in the course of process and transport of NDV proteins would be further revealed, and then elucidates the biological roles of CG-1B during NDV infection and its molecular mechanisms.