大气细颗粒物与流感病毒相互作用及致毒效应研究

Air pollution has serious direct effects on public health. Extremely polluted weather related to atmospheric fine particulate matters pollution, such as heavy haze and fog, has impacted China severely and frequently over the past few years. The surface of particulate matters could easily be adhered by inhalable microorganisms and viruses which are responsible for various allergies and respiratory diseases such as influenza. The atmospheric fine particulate matters may play a role in influenza occurrence and spread, which may have drawn widespread public concern.However, little is known about the relationship between atmospheric fine particles and epidemic influenza and how these fine particulate matters promote the viruses invading like influenza infection. In this proposal, we will collect particulate matter samples from Wuhan city and the surrounding region, the area with high humidity in South China. And we will analyze the essential components and influenza virus in the atmospheric fine particulate matters in collected samples. We will also study the effect of specific and definite fine particulate matters on influenza infection. Further, using primary alveolar macrophage and mouse model, we will attempt to study the synergistic toxicological effect of atmospheric fine particulate matters and simulative atmospheric fine particulate matters with influenza virus on cell apoptosis, inflammatory cytokines release, and mouse mortality, pulmonary infection, virus susceptibility, etc. The planning study will illuminate the mechanism of synergistic toxicological effect of atmospheric fine particulate matter and influenza virus. Also it will clarify the interaction between atmospheric fine particles and epidemic influenza, which will lay the foundation for researches of toxicological effect of heavy fog haze on the public health.

大气细颗粒物是大气污染物的重要组分之一，不仅影响气候和空气质量，而且严重危害人群健康。大气细颗粒物表面能吸附各种微生物如流感病毒，极易传播诱发流感等呼吸道疾病，造成大规模流行，引起公众的恐慌。然而，大气细颗粒物与流感病毒的相互作用关系以及颗粒物如何协同病毒感染机体的致病机制却并不清楚。因此，本项目结合我国南方大气雾霾湿度较高的特点，拟采集武汉市及周边雾霾发生时的大气细颗粒物与流感病毒混合物，分析颗粒物组分、颗粒物中流感病毒含量和分布以及颗粒物不同组分对流感病毒侵染能力的影响。以肺泡巨噬细胞和动物小鼠为实验模型，系统研究携带流感病毒的雾霾大气细颗粒物、人工模拟大气细颗粒物与流感病毒混合物对肺泡巨噬细胞引起细胞凋亡、诱导细胞炎症因子风暴以及对小鼠易感性、肺部炎症和病变等影响，深入解析雾霾发生时大气细颗粒物与流感病毒的相互作用关系和感染致病机制，为大气细颗粒物的毒理与健康效应研究奠定基础。

大气细颗粒物表面能吸附各种微生物如流感病毒，极易传播诱发流感等呼吸道疾病。该项目是大气环境研究领域关注的热点问题之一。本项目主要研究了大气细颗粒物协同促进流感病毒感染的机制。主要包括：雾霾发生时大气细颗粒物的收集及颗粒物成分分析及表征，雾霾收集物中颗粒物主要元素成分为硅、铜、铁、碳等。透射电镜成像表明微米级的颗粒物是由大量小粒径的颗粒物团聚而成，这些细小颗粒形成的团聚物极易包裹和携带微生物或病毒。进一步，研究了雾霾收集物中不同成分对流感病毒侵染能力的影响，结果表明，雾霾收集物中微细颗粒物本身即促进流感病毒感染宿主细胞，导致细胞凋亡；研究了大气细颗粒物与流感病毒感染肺癌细胞的致毒效应，包括大气细颗粒物对细胞凋亡的影响，以及通过荧光标记流感病毒，实时示踪颗粒物与流感病毒在细胞内的动态运动及分布规律。结果表明，大气细颗粒物本身不会引起细胞凋亡，却显著促进流感病毒感染宿主细胞，并导致细胞凋亡。深入研究其机制，发现大气细颗粒物极容易吸附于细胞表面，并与病毒配体相互作用，导致病毒更容易识别宿主细胞，显著增加病毒进入拷贝数。此外，颗粒物的摄入诱导宿主细胞早期内体酸化，更有利于流感病毒与细胞内体发生内膜融合，促进流感病毒的脱壳。病毒的脱壳加速了病毒对宿主细胞的有效感染，从而加速宿主细胞凋亡和坏死。针对流感病毒的脱壳过程，我们建立了量子点标记的流感病毒脱壳模型，实时动态示踪了单个流感病毒脱壳的动态过程。进一步，实时动态成像了流感病毒侵染宿主细胞过程中大气细颗粒物对流感病毒在细胞早期内体内融合的影响，结果表明，大气细颗粒物能增强流感病毒的进入和与细胞早期内体的融合。总之，大气细颗粒物可以增强流感病毒对机体的感染和致毒能力。该项目为大气细颗粒物的毒理与健康效应研究奠定基础，为雾霾后期人群流感爆发的防治提供重要参考。项目研究的部分结果已撰写成学术论文发表在PNAS, J Virol等杂志上。