摘 要
禽流感病毒跨种传播是威胁公共卫生安全的重要问题，其分子机制尚未完全阐明。本研究旨在揭示禽流感病毒突破宿主屏障的关键分子基础，为防控策略提供理论依据。研究采用多组学整合分析策略，结合深度测序、结构生物学和功能验证实验，系统解析了H5N1、H7N9等亚型禽流感病毒的跨种传播特征。通过比较不同宿主来源的病毒株，发现HA蛋白受体结合域的关键氨基酸位点突变显著影响病毒与人类呼吸道受体的亲和力。进一步研究表明，PB2蛋白E627K突变可增强病毒在哺乳动物细胞中的复制能力，而NS1蛋白的PDZ结构域缺失则降低了病毒的致病性。利用冷冻电镜技术首次解析了H7N9病毒聚合酶复合物的高分辨率三维结构，揭示了其适应哺乳动物宿主的分子基础。此外，通过构建嵌合病毒模型，证实了内部基因片段的重配对病毒跨种传播能力具有重要调控作用。研究还发现宿主因子ANP32A的多态性与病毒跨种传播效率密切相关。这些发现不仅深化了对禽流感病毒跨种传播分子机制的认识，还为新型抗病毒药物设计和疫苗开发提供了重要靶点。
关键词：禽流感病毒，跨种传播，分子机制，HA蛋白，PB2蛋白
Abstract
Inter-species transmission of avian influenza virus is an important problem threatening public health security, and its molecular mechanism has not been fully elucidated. This study aims to reveal the key molecular basis of avian influenza virus to break through the host barrier and provide theoretical basis for prevention and control strategies. In this study, the cross-species transmission characteristics of H5N1, H7N9 and other subtypes of avian influenza viruses were systematically analyzed using multi-omics integration analysis strategy, combined with deep sequencing, structural biology and functional verification experiments. By comparing virus strains of different host origin, it was found that the mutation of key amino acid sites in the HA protein receptor binding domain significantly affected the affinity of virus to human respiratory tract receptors. Further studies showed that PB2 protein E627K mutation enhanced viral replication in mammalian cells, while NS1 protein PDZ domain deletion reduced viral pathogenicity. The high-resolution three-dimensional structure of the polymerase complex of H7N9 virus was analyzed by cryo-electron microscopy for the first time, revealing the molecular basis of its adaptation to mammalian hosts. In addition, by constructing a chimeric virus model, it was confirmed that the inter-species transmissibility of rematched viruses with internal gene fragments plays an important role in regulation. It was also found that the polymorphism of host factor ANP32A was closely related to the efficiency of cross-species transmission of the virus. These findings not only deepen the understanding of the molecular mechanism of inter-species transmission of avian influenza virus, but also provide an important target for novel antiviral drug design and vaccine development.
Key words: Avian influenza virus, cross-species transmission, molecular mechanism, HA protein, PB2 protein
目 录
1 绪论 1
1.1 禽流感病毒跨种传播的研究背景 1
1.2 禽流感病毒跨种传播的公共卫生意义 1
1.3 禽流感病毒跨种传播研究现状综述 1
2 禽流感病毒受体结合特性研究 2
2.1 禽源与人源受体差异分析 2
2.2 HA蛋白受体结合域关键位点鉴定 3
2.3 受体结合特异性与宿主范围的关系 3
2.4 受体结合特性进化分析 4
3 禽流感病毒聚合酶适应性研究 4
3.1 PB2蛋白E627K突变的功能验证 4
3.2 聚合酶复合体与宿主因子互作机制 5
3.3 RNA聚合酶活性与宿主适应性的关系 6
3.4 聚合酶适应性突变的分子基础 6
4 禽流感病毒跨种传播的分子屏障研究 7
4.1 NS1蛋白在宿主适应中的作用机制 7
4.2 M基因对病毒复制效率的影响 8
4.3 NP蛋白核定位信号的功能解析 8
4.4 跨种传播相关基因的协同进化分析 9
5 结论 9
参考文献 11
致谢 12
