基于流感风热证小鼠模型探讨“温邪上受，首先犯肺”的鼻黏膜免疫TLR3/TRIF信号机制

Influenza is a major respiratory infectious disease which severely threatens the public health and has a high degree of morbidity and infectivity. Nasal mucosal immune system plays an important role in resisting and treating influenza. A consensus has been reached on the use of the theory of Warm Disease to guide the prevention and treatment of influenza."Warm pathogens attack the upper of the body，the lungs are invaded first" is a high summary of the law of the initial transmission of most respiratory diseases. It is similar to the pathogenesis of influenza virus infection in the human body, while it is not clear about its biological mechanism. Consequently, based on the classical influenza mice model, ①the studies simulate the invasion of the wind-heat pathogen and influenza virus and establish the combination model of influenza and wind-heat syndrome in mice. The model will be comprehensively evaluated by animal signs, tissue pathology, the viral load and the effect of drugs’ counterevidence. ② Guided by the pathogenesis of Weifen syndrome, the model is taken as the carrier to observe the biological mechanism of the TLR3/TRIF signaling pathway by the dynamic changes of cytokines related to the pathway at different time points. ③The YinQiao Powder, which is the representative prescription to cure the Wind-heat syndrome of Weifen syndrome, is chosen to verify the model and provide the evidence about the hypothesis. It is also useful to explain how the YinQiao Powder play a role in anti-viral.

流行性感冒是发病率高、传染性强，严重危害国民健康的呼吸系统传染性疾病，鼻黏膜局部免疫在抵御和治疗流感中发挥重要作用。运用温病学理论指导流感防治已达成共识，“温邪上受，首先犯肺”是温病学对多数呼吸系统传染性疾病早期传变规律的高度概括，与流感病毒感染人体的发病机制类似，但其生物学机制尚不清楚。本项目拟在经典的流感小鼠模型基础上：①模拟“风热刺激与流感病毒”从口鼻侵入，建立流感风热证小鼠病证结合模型。从动物体征、组织病理和病毒载量等客观指标及药物反证疗效对模型进行综合评价。②以该模型为载体，“温邪上受”初期邪在卫分的病机为指导，从鼻黏膜免疫TLR3/TRIF信号通路入手，观察“温邪上受"后不同时间点该通路相关细胞因子的动态变化，阐释其生物学基础。③选用风热犯卫证代表方银翘散对该模型进行干预验证，为“温邪上受，首先犯肺”的鼻黏膜免疫机制和银翘散的抗病毒作用机制提供依据。

流行性感冒是发病率高、传染性强，严重危害国民健康的呼吸系统传染性疾病，鼻黏膜局部免疫在抵御和治疗流感中发挥重要作用。本项目在温病学经典病因病机理论“温邪上受，首先犯肺”指导下，建立了流感风热证小鼠模型，并从TLR3/TRIF信号通路入手阐明了“温邪上受，首先犯肺”的可能生物学机制。研究内容包括：①建立了流感风热证小鼠模型，并从小鼠一般生命体征、血常规、肺指数、组织病理、病毒载量及方药反证等多角度予以评价；②以流感风热证小鼠模型为载体，观察模型小鼠在造模后第3、第5天一般生命体征、血常规、肺指数、组织病理、病毒载量及TLR3/TRIF信号通路相关因子的动态变化情况。研究结果显示，造模后第3天，小鼠出现不同程度的竖毛、拱背、发抖与扎堆现象，体温、体重下降，饮水量增加，炎性细胞计数升高，肺指数增高，鼻黏膜病理出现炎症表现，病毒载量升高，TLR3/TRIF信号通路相关因子表达增加。以上指标在第5天均呈明显上升趋势，且呈现“由鼻及肺”的病理变化趋势。③银翘散干预模型后，可以改善模型小鼠的一般生命体征、血常规、肺指数、组织病理炎症反应，降低鼻黏膜、肺组织病毒载量及TLR3/TRIF信号通路因子表达水平，有确切的抗病毒作用，在改善一般生命体征、血常规，降低肺指数及组织病理炎症反应、病毒载量及细胞因子表达等方面优于奥斯他维。综上所述，本研究以流感风热证小鼠模型为研究载体，初步阐明了“温邪上受，首先犯肺”的生物学机制，为中医药防治流感以及祖国医学病因病机的现代生物学机制研究提供了实验室依据。