牛UK株轮状病毒拮抗Ⅰ型IFN信号转导通路机制的研究

Rotaviruses are the single most important cause of severe diarrheal disease in infants and immature animals worldwide, resulting in high percentage of morbidity and mortality annually and responsible for heavy social burden in humans and economy loss in animal industries. Rotaviruses have gained multiple mechanisms to convert or antagonize host innate immune defense system, including gamma-interferon. Bovine-human reassortant oral, attenuated rotavirus vaccine based on bovine RV strain has been tested in some developing countries, however, the efficacy of vaccine is significantly lower than that in industrialized countries. Moreover, some cases that the infants and children developed severe diarrhea due to administration of rotavirus reassortant vaccine, were widely reported recently and the subjects require the emergency care. The mechanisms that how rotaviruses vaccines are attenuated and pathological changes due to rotavirus infection remain unknown. To help develop novel and efficacious vaccines and/or therapeutic reagents to protect against rotavirus diseases, it is urgent and necessary to study how rotaviruses antagonize innate immune defense systems. This study aims at overhauling mechanisms how bovine rotavirus UK strain, i.e. mother strain in UK-based pentavalent reassortant vaccine, converts IFN-β signal transduction by immunofluorescence assay, small interfere RNA (siRNA), co-immune precipitation(Co-IP) and real-time PCR methods and be in an attempt to understand how bovine rotavirus employs immune escape, carries on pathological process and to help design therapeutic medicine and efficacious vaccine.

轮状病毒（Rotavirus, RV）性胃肠炎是婴幼儿及多种幼龄动物的一种急性传染病，发病率和死亡率高，给人类健康和畜牧业发展造成极大危害。当前牛-人基因重配等疫苗在发展中国家的免疫效力和安全性差强人意，疫苗致弱以及RV致病机制研究还不深入。针对病毒免疫逃避的研究有助于深入探讨RV的致病机制、开发新型疫苗及治疗性制剂。本项目以RV免疫逃避为出发点，通过免疫荧光、siRNA、Co-IP、Real-time PCR等方法，研究细胞内模式识别受体分子在抗RV信号转导中的作用、毒力决定因子NSP1蛋白拮抗IFN-β信号转导通路上的靶位点和作用方式，研究NSP1蛋白与宿主细胞间的相互作用并定位其功能区域。旨在探讨疫苗母本株牛RV拮抗宿主Ⅰ型IFN信号转导通路，在分子水平上阐明牛RV免疫逃避的详细机制。本研究预期结果将利于深入探讨RV致病机制，为疫苗设计、治疗性药物的开发、疫苗安全效力分析提供新策略。

轮状病毒（Rotavirus, RV）性胃肠炎是婴幼儿及多种幼龄动物的一种急性传染病，发病率和死亡率高，给人类健康和畜牧业发展造成极大危害。当前牛-人基因重配等疫苗在发展中国家的免疫效力和安全性差强人意，疫苗致弱以及RV致病机制研究还不深入。针对病毒免疫逃避的研究有助于深入探讨RV的致病机制、开发新型疫苗及治疗性制剂。本项目以RV免疫逃避为出发点，通过免疫荧光、siRNA、Co-IP、Real-time PCR等方法，研究细胞内模式识别受体分子在抗RV信号转导中的作用、毒力决定因子NSP1蛋白拮抗IFN-β信号转导通路上的靶位点和作用方式，研究NSP1蛋白与宿主细胞间的相互作用并定位其功能区域。通过本课题的研究，我们发现轮状病毒可以通过RIG-I通路来抑制宿主细胞的先天性免疫应答，有助于病毒的复制和增殖。同时发现UK株轮状病毒NSP1可以通过蛋白酶体依赖的机制降解干扰素调节因子(IRF)3，进而进一步抑制IFN的信号转导和宿主细胞的先天性免疫应答；缺失NSP1 C基段IRF结合结构域后，NSP1降级IRF3的能力将丧失。UK株轮状病毒NSP1不通过降解β-TrcP来抑制IFN的信号转导。上述结果将为轮状病毒的药物设计提供靶点。