miRNAs介导的自噬抑制在类鼻疽杆菌感染免疫逃逸中的作用机制研究

类鼻疽杆菌(Bp)感染严重威胁公共卫生和国家南海战略。作为一种胞内病原菌，有效逃逸机体免疫清除是Bp感染与致病的前提；而自噬是机体清除胞内感染病原发挥天然免疫的重要手段，miRNAs介导的病原与宿主相互作用成为二者免疫博弈的重要战场。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miR-4458、miR-4667-5p、miR-4668-5p表达上调，自噬受抑，从而影响了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这些miRNAs，采用WB、激光共聚焦、电镜、流式、EMSA等技术，研究其抑制自噬的具体信号通路以及其转录表达调控，观察其影响清除Bp的能力，探讨"B. pseudomallei、microRNAs与自噬"的作用模式，以期阐明miRNAs介导的自噬抑制在Bp感染免疫逃逸中的作用机制，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 south china sea conflict. The intracellular bacterium B. pseudomallei can escape from the vacuole and replicate within the host-cell cytosol which causing multidrug resistant and complicating treatment. Autophagy has been identified as an effective innate immune response to control the B. pseudomallei by enhancing intracellular bacterium clearance. However, the mechanism by which B. pseudomallei infection persist is not clear. In this study, we showed that three novel miRNAs- - -miR-4458, miR-4667-5p and miR-4668-5p by using microarray assay are upregulated in response to B. pseudomallei infection. And the autophagy-mediated anti-B. pseudomallei response is inhibited. As a potential mechanistic explanation for this observation, we demonstrate that miR-4458, miR-4667-5p and miR-4668-5p directly target ATG10, which is the important protein involved in autophagy. Furthermore, we aim to clarify the mechanism of autophagy 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.