白介素36α在脓毒血症中的免疫保护作用及机制研究

发布时间：2018-02-26 15:21

本文关键词： 白细胞介素36α 脓毒血症宿主应答巨噬细胞　出处：《重庆医科大学》2017年硕士论文　论文类型：学位论文

【摘要】：背景脓毒血症是由感染引起的全身炎症反应综合征,这种由感染引起的宿主应答调节紊乱最终会导致器官功能的紊乱,严重威胁生命。脓毒血症的死亡率很高,且目前临床对脓毒血症缺乏有效的治疗措施。近年来的研究数据提示,白细胞介素-1(Interleukin-1,IL-1)家族的新成员白细胞介素36α(Interleukin-36α,IL-36α)在炎症疾病的病理机制中占有重要地位,但其在脓毒血症中对宿主应答的作用尚未得知。方法用盲肠结扎穿刺(CLP)的方法构建脓毒血症模型,诱导多细菌感染的脓毒血症,以研究IL-36α在脓毒血症中对宿主应答的影响;用定量PCR和ELISA检测IL-36α在小鼠体内的表达量;通过进行生存率试验和细菌载量的测定,来衡量IL-36α在脓毒血症中的保护或损伤作用;取小鼠肺、肝、脾、肾组织做组织切片并做HE染色,分析组织内的炎性改变,通过TUNEL实验评判细胞凋亡程度;用流式细胞术和瑞士-吉姆萨染色来分析腹腔灌洗液中有核细胞的数量及种类;提取腹腔巨噬细胞及骨髓中性粒细胞进行体外实验,检测IL-36α对小鼠巨噬细胞和中性粒细胞的功能的影响,取细胞上清测定IL-36α对炎症细胞因子表达的影响。结果IL-36α在脓毒血症中的表达显著上调。IL-36α处理过的CLP重症脓毒血症模型小鼠的死亡率降低。与PBS对照组小鼠相比,IL-36α处理组小鼠表现出更有效的细菌清除能力,组织炎症程度被抑制,器官损伤更轻,且免疫细胞凋亡减少。IL-36α在脓毒血症中还可能具有治疗价值,这在使用IL-36α抗体的实验中也得到了证实,特异性地封闭体内IL-36α导致在轻度脓毒血症中小鼠的死亡率增加。除此之外,我们还发现IL-36α增强了巨噬细胞对细菌的吞噬和杀伤,从而使得局部和全身的细菌清除能力增强。更重要的是,在构建脓毒血症模型之前耗尽小鼠体内巨噬细胞,IL-36α的这种保护作用就消失了。结论我们的结果表明IL-36α在宿主对脓毒血症的防御应答中发挥了重要的保护作用,并提示IL-36α对脓毒血症具有潜在的治疗效果。
[Abstract]:Background sepsis is a systemic inflammatory response syndrome caused by infection. The host response regulation disorder caused by infection can eventually lead to organ dysfunction, which is a serious threat to life. The mortality rate of sepsis is very high. Recent studies indicate that interleukin-36 伪 (IL-36 伪), a new member of the Interleukin-36 伪 (IL-36 伪) family, plays an important role in the pathological mechanism of inflammatory diseases. Methods the sepsis model was established by cecal ligation and puncture to induce sepsis caused by bacterial infection, in order to study the effect of IL-36 伪 on host response in sepsis. Quantitative PCR and ELISA were used to detect the expression of IL-36 伪 in mice. Survival test and bacterial load were used to evaluate the protective or injury effect of IL-36 伪 in sepsis. Renal tissue sections and HE staining were used to analyze the inflammatory changes in the tissues and the degree of apoptosis was evaluated by TUNEL assay, and the number and types of nucleated cells in peritoneal lavage fluid were analyzed by flow cytometry and Swiss Gimsa staining. Peritoneal macrophages and bone marrow neutrophils were extracted to investigate the effects of IL-36 伪 on the function of mouse macrophages and neutrophils. The effect of IL-36 伪 on the expression of inflammatory cytokines was measured by supernatant. Results the expression of IL-36 伪 in sepsis was significantly up-regulated. The mortality of CLP model mice treated with IL-36 伪 was decreased. Compared with the control group of PBS mice, the mortality of IL-36 伪 was significantly decreased. The mice in the treatment group showed more effective bacterial clearance. Tissue inflammation is inhibited, organ damage is lighter, and reduced apoptosis of immune cells. IL-36 伪 may also have therapeutic value in sepsis, which has also been confirmed in the use of IL-36 伪 antibody. Specific blocking of IL-36 伪 in vivo leads to an increase in mortality in mice with mild sepsis. In addition, we found that IL-36 伪 enhanced phagocytosis and killing of bacteria by macrophages. Which increases the ability to remove bacteria locally and throughout the body. More importantly, The protective effect of IL-36 伪 on macrophage in mice was disappeared before the model of sepsis was established. Conclusion our results suggest that IL-36 伪 plays an important protective role in the host's defense against sepsis. The results suggest that IL-36 伪 has potential therapeutic effect on sepsis.
【学位授予单位】：重庆医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R459.7

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