【作者】 王渠龙；

【导师】 邵健忠； 项黎新；

【作者基本信息】 浙江大学 ， 细胞生物学， 2010， 硕士

【摘要】 1966年发现了一种可抑制巨噬单核细胞移动的细胞因子,正式命名为巨噬细胞移动抑制因子(macrophage migration inhibitory factor,MIF),它是最早被鉴定的细胞因子之一。经过近几十年的研究发现,MIF是对发育、先天性免疫等发挥重要作用的多功能细胞因子,MIF被认为是调节其他炎症因子释放的炎症反应调控点。本文通过建立Aeromonas hydrophila引起的斑马鱼败血症模型,研究了MIF在细菌性败血症中的生物学功能。结果显示细菌感染后MIF含量迅速上升,而额外注射重组MIF会加剧败血症,当用抗MIF抗体处理后则能够明显缓解败血症,表明过量的MIF是有害的。我们的研究发现细菌感染诱导MIF,TLR5a,TLR5b,TLR9,TLR20a,IL-1β和TNF-α的产生,这些因子的相互关系研究证明细菌感染后MIF被释放出来,诱导TLR5a,TLR5b,TLR9,TLR20a的表达,大量的TLR受体使鱼体保持一种对细菌高敏感的状态,TLR受体识别并结合病原体相关分子模式(PAMPs),激活炎症信号通路,诱导大量炎症因子,而过量的炎症因子引起剧烈炎症反应,甚至导致鱼体休克。同时,我们用Tetraodon的MIF在斑马鱼上的功能研究与斑马鱼MIF的结果相似,显示出鱼类中MIF功能的保守性。对鱼类MIF的功能研究不仅丰富了鱼类免疫学知识,而且有助于深入了解MIF的分子进化及其在炎症反应中的作用。该研究还能为基于MIF治疗的临床研究和药物筛选提供一种新的鱼类模型。更多还原

【Abstract】 Over the last decades, MIF has emerged to be a multi-functional cytokine that played pivotal roles in variety of biological activities, especially in innate immunity, MIF was believed to be critical in the control of inflammatory responses ’set point’ by regulating the release of other pro-inflammatory cytokines. In the present study, by establishment of A.hydrophila mediated zebrafish sepsis model, we investigated the functions of MIF in the bacterial sepsis. The result showed that MIF was up-regulated after bacterial infection, and a bolus of recombinant MIF could exacerbate sepsis induced by this infection, neutralization of the MIF activity with anti-MIF antibody could protect fish from septic shock, confirming the harmful effect of an excessive amount of MIF. Our study showed that MIF, TLR5a, TLR5b, TLR9, TLR20a, IL-1βand TNF-αwas induced after infection with A.hydrophila, the research of the relationship between those during sepsis demonstrated that MIF was released after bacterial infection, which induced the expressions of TLR5a, TLR5b, TLR9, TLR20a, these abundant of TLRs made the body in the state of highly sensitive to the bacterial, TLRs recognized the molecules called pathogen-associated molecular patterns(PAMPs) of the bacteria, activating the cascade of the inflammatory pathway, resulting in releasing of inflammatory factors such as IL-1βand TNF-α, and if overdose of which will causing septic shock. The results using Tetraodon MIF in zebrafish were nearly the same of that using zebrafish MIF in zebrafish, confirming the conservatism of MIF between fishes. We hope that our functional characterization of MIF in fish will not only enrich the knowledge of fish immunology, but will also contribute to a better cross-species understanding of the evolutionary history of the MIF family and MIF-mediated regulatory roles in inflammatory immunity. We also hope that it will provide an opportunity to develop a novel fish model for clinical investigations and medical applications of MIF based therapies更多还原