长链非编码RNA lnc-EV 在EV71感染手足口病天然免疫应答调控中的作用和机制研究

EV71-induced severe hand foot and mouth disease (HFMD) has highly disability and mortality rate for the reason of un-controlled inflammatory response in central nervous system, but the underlying innate immune mechanism is still unclear. Long non-coding RNAs are involved in many of physiological and pathological processes, however, there are little know between lncRNAs and EV71-infection. In our preliminary study, lnc-EV was significantly differently expressed in EV71-infected THP1-derived macrophages in high-throughput transcriptome microarray analysis. We further confirmed the expression of lnc-EV was up-regulated in THP1-derived macrophages infected with EV71. Lnc-EV silencing by specific siRNA could promote the production of cytokines induced by EV71, which indicate that lnc-EV may serve as a negative regulator in innate immune response. In the research, we will identify lnc-EV function in innate immunity against EV71 infection through investigating the influence of lnc-EV in regulation of cytokines and the innate immune signaling transduction. Systematic research will be performed to clarify lnc-EV target genes and protein interaction, uncovering the mechanism of lnc-EV in innate immune regulation. Furthermore, we will confirmed the expression of lnc-EV in clinical specimens of EV71-infected HFMD patients and healthy control, to reveal the relation of lnc-EV and EV71-infected severe HFMD. Our research will provide a new theoretical support for clinical diagnosis and treatment of EV71-infected HFMD.

EV71感染引起重症手足口病，患儿因炎症反应失调引起严重中枢神经系统并发症，致残率和死亡率高，而相关天然免疫调控机制并不清楚。lncRNA参与多种生理病理过程调节，而EV71感染相关lncRNA作用和机制目前鲜有报道。我们通过lncRNA芯片得到EV71感染巨噬细胞中lncRNA的表达谱，筛选并验证了lnc-EV表达显著上调，siRNA干扰lnc-EV表达能够促进巨噬细胞中EV71诱导的炎症因子产生，据此推测lnc-EV可能通过负向调控细胞因子产生参与EV71触发的天然免疫调控。本项目拟通过研究lnc-EV对细胞因子和天然免疫信号转导的影响，揭示其在天然免疫抵御EV71感染中的功能；通过系统研究lnc-EV靶基因和相互作用蛋白，阐明其调控天然免疫的机制；通过在EV71感染手足口病临床标本研究lnc-EV的表达，分析lnc-EV与EV71重症感染的相关性，为临床诊断、治疗提供新的理论支持。

肠道病毒71（EV71）是引起手足口病的主要病原体之一，能够触发细胞因子和趋化因子的过量产生，导致一系列的局部或系统性炎症反应甚至严重的中枢神经系统并发症，具有较高的致残率和死亡率，然而其相关的发病机理和调节机制目前并不清楚。lncRNA参与多种生理和病理过程的调节，而EV71感染相关lncRNA的作用和机制鲜有报道。通过lncRNA芯片检测EV71感染巨噬细胞中lncRNA的表达谱，筛选并验证了lnc-EV表达显著上调。通过siRNA靶向干扰lnc-EV的表达能抑制EV71诱导的细胞因子产生。EV71感染手足口病患者lnc-EV的表达水平与血清中IL-6、TNF-α和CCL3的浓度成正相关；EV71感染重症患者组lnc-EV的表达水平要显著高于轻症患者组。进一步机制研究发现，lnc-EV能够抑制TRIM2与MDA5相互作用，阻碍TRIM2对MDA5的K48位泛素化降解，促进下游NF-κB和MAPK天然免疫信号转导，促进炎症因子的产生。研究揭示了lnc-EV在天然免疫中的新功能，和EV71触发天然免疫反应新的调控机制，并进一步丰富了MDA5泛素化调节的机制，而lnc-EV也有望作为潜在干预靶标用于EV71炎症反应失调的干预和治疗。