Notch信号调控TLR信号的靶点筛选及其在抗感染免疫中的作用

TLR signal-triggered immune response play important role in resistant of pathogen in the body. Notch signaling is a highly conserved pathway determining cell fate including cell growth, differentiation, and survival. Recent evidences suggest that Notch signaling modulate TLR-mediated inflammatory response, and our previous study also showed Notch signaling suppressed TLR4-triggered inflammatory responses by inhibiting ERK1/2- NF-kB signal pathway. However, the detailed underlying molecular mechanism, the cross-talk and direct target between Notch signaling and TLR signal was unclear. This study firstly screen the Notch-related gene in TLRs signaling pathway by gene microarray and mass spectrometry techniques; Subsequently， detect the binding of NICD with potential target gene ，spatial location and regulatory mechanism. Finally, we further investigated the role of molecular mechanism in TLR signal mediated anti-infection immunity. Our preliminary findings showed that the cross-talk between Notch signaling and TLRs signal was not converged on ERK1/2, suggesting that other molecule was involved in the regulatory mechanism. This study will explore a regualtory moleculer mechanism of TLR signal by Notch signaling , enrich the regulatory mechanism of Notch in inflammation response , and provide a new therapeutic target for clinical inflammation.

TLR信号激发的免疫应答在机体抵抗病原体中发挥了重要的作用。Notch信号是一高度保守的信号途径，在细胞的生长、分化和存活过程中发挥中作用。研究表明Notch信号可调控TLR介导的炎症反应，我们以往研究发现Notch信号抑制ERK-NF-kB负向调控TLR4触发的炎性细胞因子分泌，但对于分子调控机制、直接靶点、及其在抗感染免疫中的作用不清楚。本课题首先通过基因芯片和质谱分析筛选出TLR通路中与Notch相关的基因；其次，检测筛选基因与Notch分子结合及Notch对筛选蛋白的调控机制；最后，探讨此分子机制在Notch调控TLR信号介导的抗感染免疫中的作用。初步研究发现Notch信号对TLR信号的调控机制不在ERK分子，可能涉及其他分子。本项目的完成将揭示Notch信号对TLR信号调控的分子机制，丰富Notch调控炎症的机制，为临床炎症的防治提供新靶点。

TLR信号激发的免疫应答在机体抵抗病原体中发挥了重要的作用。Notch信号是一高度保守的信号途径，在细胞的生长、分化和存活过程中发挥中作用。本研究主要研究Notch信号对病原体感染的调控和调控机制（靶点筛选和验证）。我们发现病毒刺激( HSV和VSV)刺激腹腔巨噬细胞，Notch信号活化相关的分子（Notch1-4，Notch的配体：DLL1-4，Jaggerd1和2）明显上调，这提示在病毒刺激下，Notc1h信号活化，参与病毒反应调控。Notch表达缺失可显著下调poly I:C、HSV、VSV和SEV诱导的IFN-的分泌。Notch1表达缺失并不影响HSV和VSV触发的信号通路（MAPK（ERK1/2、p38和JNK1/2）以及IRF3的磷酸化，但可增强IRF3介导的转录。基因芯片分析发现，Notch1表达缺失的巨噬细胞中，ZFP64和JMJD3表达明显下调，其中对于ZFP64在调控天然免疫的相关研究已发表于SCI论文（ J. Biol. Chem. 2013, 288:24600-24608）。我们进一步研究了JMJD3对IFN-的调控机制，发现干扰JMJD3的表达可抑制病毒触发的IFN-的产生。对于Notch1 如何调控JMJD3的表达，我们发现VSV刺激下，p300可以被募集到JMJD3 DNA 启动子区，Notch1缺失的巨噬细胞中，JMJD3 启动子区的p300募集的明显降低。因此，我们认为cleaved Notch1结合p300,促进p300介导的JMJD3的乙酰化，继而促进JMJD3的表达。