脂噬在类鼻疽菌胞内持续性感染中的作用机制研究

摘要：类鼻疽菌(Bp)感染严重威胁公共卫生和国家安全。作为一种胞内病原菌，类鼻疽菌逃逸宿主免疫造成的持续性感染是其防治的关键。宿主脂质代谢和病原感染相互影响，在病原微生物感染致病中发挥重要作用。课题组前期通过芯片筛选和功能实验验证发现Bp感染后宿主细胞NR1D2表达上调，自噬受抑，脂质大量蓄积，并影响Bp的清除，但机制未明。本项目拟在Bp感染的细胞和动物模型中，通过真核转染上调或下调NR1D2，采用WB、激光共聚焦、电镜、流式、EMSA等技术，研究脂噬在类鼻疽菌持续性感染中的作用，探讨“B. pseudomallei、自噬与脂质代谢”三者关系，以期阐明NR1D2介导的自噬调节脂质代谢在Bp持续性感染中的机制，为寻找其有效的治疗药靶提供线索。

Burkholderia pseudomallei is the causative agent of melioidosis, which is a potential threat to public health and national security. The intracellular bacterium B. pseudomallei can escape from the vacuole and replicate within the host-cell cytosol which causing persistent infection and complicating treatment. The interaction of host lipid metabolism and pathogen infection plays an important role in the pathogenesis of pathogenic microorganisms. However, the mechanism by which B. pseudomallei infection persist is not clear. In this study, we showed that NR1D2 by using microarray assay are upregulated in response to B. pseudomallei infection. And the lipids accumulated in large quantities and the autophagy-mediated anti-B. pseudomallei response is inhibited. As a potential mechanistic explanation for this observation, we demonstrate up-regulate or down-regulate NR1D2 by eukaryotic transfection in Bp-infected cells and animal models, and use WB, LSCM, electron microscopy, flow and EMSA techniques to study the function in lipophagy in persistent intracellular infection of Burkholderia pseudomallei. Furthermore, we aim to clarify the mechanism of lipophagy inhibited by B. pseudomallei in vivo and in vitro, and search for new approaches to the treatment of B. pseudomallei infection to provide theoretical guidance.