TLR4活化树突状细胞调节中性粒细胞参与脓毒症发生发展的机制研究

项目名称： TLR4活化树突状细胞调节中性粒细胞参与脓毒症发生发展的机制研究

项目编号： No.81471841

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 医药、卫生

项目作者： 马涛

作者单位： 天津医科大学

项目金额： 80万元

中文摘要： TLR4与树突状细胞（DC）变化和脓毒症发生发展密切相关，但机制不详。我们发现，DC条件性TLR4敲除（DC TLR4 KO）小鼠盲肠结扎穿孔（CLP）术后，腹腔内中性粒细胞比例增加，细菌清除改善，而DC IL-10生成减少，提示，脓毒症中TLR4可能通过活化DC，生成IL-10，调节中性粒细胞趋化，影响细菌清除参与脓毒症病生理过程。为此，拟采用DC TLR4 KO、Flox、TLR4 KO和WT小鼠，检测CLP术后，DC数量、凋亡和功能等，及细菌清除、炎症反应和生存率等，揭示TLR4在DCs变化中的作用及病生理意义；检测腹腔内中性粒细胞数量、趋化和CXCR2表达等，结合转移输注和抗体清除，证实DC TLR4对中性粒细胞趋化的影响和效应；通过体内外实验，证实DC TLR4以IL-10依赖机制影响中性粒细胞趋化参与脓毒症发病；以深化对脓毒症病生理机制的认识，并为脓毒症治疗提供潜在作用靶点。

中文关键词： 脓毒症；树突状细胞；中性粒细胞；Toll样受体4

英文摘要： It has been accepted that there is close relationship among TLR4 signaling, Dendritic cells and sepsis, however, the underlying mechanisms is still elusive. We found that, after CLP procedure, bacterial clearance in DC TLR4 knockout mice improved significantly, simultaneously the percentages of neutrophils in the peritoneal cavity also incresed; whereas the IL-10 production by isolated DCs from these mice decreased significantly. The above data strongly indicate that, during sepsis, Dendritic cells activated by TLR4 may regulate the recruitment of neutrophils into inflammatory sites via the production of IL-10, then influence the pathiophysiology of sepsis.Therefore, in the present study, we will first investigate the numbers, function,apoptosis of Dendritic cells, and the effects on bacterial clearance, inflammatory response and survival by using DC TLR4 KO, Flox, TLR4 KO and WT mice; Secondly，we will analysis the numbers, chemotasis, and CXCR2 expression of neutrophils in peritoneal cavity, in combination with adoptive transfer and antibody depletion experiment; finally, we plan to demonstrate whether DCs regulate neutrophils recruitment via production of IL-10. The accomplishment of the present proposal will not only help us to make a better understanding of the pathophysiology of sepsis, but also provide possible targets for early intervention of sepsis.

英文关键词： Sepsis;Dendritic cells;Neutrophils;Toll like recptor 4