Wolbachia提高埃及伊蚊活性氧抑制登革病毒传播的机制研究

Wolbachia induces the pathogen interference such as significant inhibition to dengue virus or even complete blocking of dengue virus transmission in Ae. aegypti, which reveals the prominent potential of Wolbachia-based mosquito control as an innovational strategy in field implementation. The understanding of Wolbachia induced antiviral mechanisms is crucial for better utilization of Wolbachia in mosquito vector control strategies. The applicant has demonstrated that Wolbachia induces reactive oxygen species (ROS) to activate Toll pathway contributing to dengue virus inhibition via up-regulation of antimicrobial peptides in Ae. aegypti. Furthermore, we have shown that Wolbachia induces intracellular ROS, mitochondrial ROS and ATP production in Ae. aegypti. These results indicate that Wolbachia might utilize host mitochondria to manipulate host energy metabolism and cause an overproduction of intracellular ROS. Hence, this grant proposal is aimed at elucidating the mechanism underlying the regulation of host energy metabolism, host energy storage and elevated host ROS production by Wolbachia. Moreover, this study will analyze the impact of intracellular and extracellular ROS on dengue virus life cycle as well as the role of Wolbachia elevated ROS in vector competence for dengue virus serotype-I to IV in Ae. aegypti. The outcome of this project could promote the better understanding of mechanism of Wolbachia induced inhibition of dengue virus transmission in Ae. aegypti. It is important for implementation of Wolbachia-based vector control strategies in prevention and control of arboviral diseases.

沃尔巴克氏体（Wolbachia）因调控媒介蚊宿主，实现显著抑制甚至完全阻断登革病毒传播，揭示其成为新型蚊媒控制技术的潜力和前景。深入理解沃尔巴克氏体介导的抗病毒机制，可更好的应用基于沃尔巴克氏体的蚊媒控制技术。申请人前期工作表明沃尔巴克氏体增高埃及伊蚊活性氧，而激活宿主免疫Toll通路，进而增高抗菌肽表达，抑制登革病毒。进一步发现，沃尔巴克氏体提高宿主细胞内活性氧及线粒体活性氧、ATP含量。提示沃尔巴克氏体可通过线粒体调控宿主能量代谢而增高宿主细胞内活性氧。本研究拟详细探明沃尔巴克氏体对埃及伊蚊能量代谢与存储的调控，阐明其增高宿主细胞内活性氧的机制。深入揭示细胞内和细胞外活性氧对登革病毒复制周期的影响，及探测沃尔巴克氏体增高活性氧对埃及伊蚊传播血清I至IV型登革病毒媒介效能的影响。这对阐明沃尔巴克氏体介导的抗登革病毒机制和应用沃尔巴克氏体预防控制虫媒疾病的传播具有重要的理论及实践意义。

沃尔巴克菌（Wolbachia）通过调控媒介蚊宿主使其表现出对病原体的显著抗性，因此显示其成为新型蚊媒控制策略的潜力和前景。深入理解沃尔巴克菌介导的抗病毒机制，有助于科学推广沃尔巴克菌在蚊媒控制技术的应用。为了进一步全面探明沃尔巴克菌如何激发宿主抗登革病毒感染的功能，本课题通过体内外实验证实沃尔巴克菌可通过调控埃及伊蚊线粒体呼吸链复合物I-V，提高线粒体数量及线粒体活性氧含量，进而提高胞内活性氧水平和埃及伊蚊体内总活性氧水平。活性氧水平的升高可激活宿主Toll通路，释放抗菌肽抵御登革病毒感染。并且，经高效液相色谱和荧光成像分析显示沃尔巴克菌通过调控埃及伊蚊宿主线粒体数量而提高宿主胞内ATP、ADP，以及胞外AMP的含量，影响宿主能量代谢和存储。通过功能实验发现感染沃尔巴克菌的埃及伊蚊WAag2细胞的胞内和胞外活性氧均能抑制登革病毒感染埃及伊蚊细胞。由此提示，沃尔巴克菌可同时利用细胞内和细胞外活性氧，协同作用抵御登革病毒的感染。本研究详细探明了沃尔巴克菌对埃及伊蚊能量代谢与存储的调控，阐明其增高宿主活性氧的机制。深入揭示细胞内和细胞外活性氧抑制登革病毒感染细胞的协同作用。这对全面理解沃尔巴克菌介导的抗登革病毒机制和应用沃尔巴克菌预防控制虫媒疾病的传播具有一定理论及实践意义。课题进展过程中，项目主持人入选省级人才项目3项，培养了博士研究生1名、硕士研究生6 名，指导了本科生科研训练9人，发表论文6 篇，参加国际会议交流2次。