RNF144B/SYK调控THP-1分化的巨噬细胞中TLR4信号通路的作用机制研究

Committed differentiation of leukemia cells is the ideal treatment strategy for leukemia. We has set up the experimental system for conducting leukemia cells differentiation into macrophage, but it remains to be answered whether these leukemia derived macrophages possess comparable functions with normal cells, and even the molecular mechanisms by which they may play a role. After a combination of gene expression variance detection, bioinformatics analysis, target gene prediction and functional assay, we find that RNF144B responds dynamically to LPS stimulation in leukemia-derived macrophages and RNF144B expression is positively correlated with that of SYK. Since SYK is reported to mediate endocytosis of TLR4, and facilitate TRIF dependent TLR4 signaling, we hypothesize that “RNF144B regulates TLR4 mediated innate immune responses by SYK”. The expected research findings will reveal whether RNF144B could regulate TLR4 mediated innate immune responses by SKY in leukemia derived macrophages for the first time both home and abroad; innovate and enrich the theory for the committed differentiation and immunocompetence of leukemia derived macrophages. The findings will also provide us with the theoretical basis for evaluation of both terminal differentiation revulsant screening and target intervention therapy, and be of great importance for theoretical and academic research.

白血病定向诱导分化是肿瘤治疗最为理想的模式。我们成功建立了白血病细胞定向分化为巨噬细胞的模型，但这些白血病来源的巨噬细胞是否具有正常细胞的功能，以及发挥功能的分子机制等都没有明确的答案。通过差异基因检测、生物信息学分析、靶基因预测和功能学验证等预实验发现白血病分化的巨噬细胞中RNF144B能够响应LPS刺激，而且RNF144B和SYK具有较强的共表达关系。因为SYK介导了TLR4的内吞并促进了TRIF依赖的信号通路，所以提出“RNF144B通过SYK参与调控TLR4介导的固有性免疫反应信号通路”的假说。预期研究结果的取得，将率先在国内外揭示白血病细胞来源的巨噬细胞是否存在着RNF144B通过SYK来调控TLR4介导的固有性免疫反应，创新和丰富单核细胞定向分化和发挥免疫活性的新理论。也为新型终末分化诱导剂筛选和靶向干预治疗效应的评估提供理论依据，具有重要的理论和学术研究价值。

固有性免疫反应必须受到精准的调控才能够阻止持续的炎症反应并有效的保护有机体免受损害。我们的研究发现RNF144B能够动态的响应LPS刺激并能够负向调控LPS所诱导的炎症反应。机制研究表明RNF144B通过自身的IBR结构域与TBK1的SDD结构域结合。这种结合能够抑制TBK1的磷酸化以及K63链接的多聚泛素化修饰，进而导致IRF3的磷酸化水平降低以及I型干扰素的表达下降从而发挥炎症抑制作用。小干扰RNA介导的RNF144B的表达下调提高了LPS诱导条件下IRF3的转录活性，并促进了I型干扰素的产生。我们的研究确认了RNF144B与TBK1的结合足以抑制TBK1介导的炎症反应的活化并揭示了RNF144B在固有性免疫反应调控中的作用功能。