de Almeida Lucia, Dorfleutner Andrea, Stehlik Christian
Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, USA.
Bio Protoc. 2016 Oct 5;6(19). doi: 10.21769/BioProtoc.1945.
Bacterial lipopolysaccharide (LPS) is present in the outer membrane of Gram-negative bacteria and functions as pathogen-associated molecular pattern (PAMP) (Whitfield and Trent, 2014). LPS therefore is a potent activator of inflammatory responses leading to cytokine release and neutrophils recruitment. The lipid A moiety of LPS activates the complex consisting of the LPS binding protein (LBP), CD14, MD-2 and Toll-like receptor 4 (TLR4) and the non-canonical inflammasome-linked caspases-4, 5 and 11, which in turn activate the canonical NLRP3 inflammasome (Shi ., 2014; Hagar ., 2013; Kayagaki ., 2013; Hoshino ., 1999; Poltorak, 1998; Nagai ., 2002; Park 2009; Ratsimandresy ., 2013). In particular, the cytokine interleukin (IL)-1β produced in response to inflammasome activation has a crucial role in neutrophil recruitment through promoting neutrophil adhesion and migration (McDonald ., 2010).This protocol allows studying of inflammatory response induced by LPS that affect neutrophil infiltration by tracking myeloperoxidase (MPO) activity (de Almeida ., 2015).
细菌脂多糖（LPS）存在于革兰氏阴性菌的外膜中，作为病原体相关分子模式（PAMP）发挥作用（惠特菲尔德和特伦特，2014年）。因此，LPS是炎症反应的有效激活剂，可导致细胞因子释放和中性粒细胞募集。LPS的脂质A部分激活由LPS结合蛋白（LBP）、CD14、MD-2和Toll样受体4（TLR4）以及非经典炎性小体相关的半胱天冬酶-4、5和11组成的复合物，进而激活经典的NLRP3炎性小体（施……，2014年；哈加尔……，2013年；加贺垣树……，2013年；星野……，1999年；波尔托拉克，1998年；永井……，2002年；帕克，2009年；拉齐曼德雷西……，2013年）。特别是，炎性小体激活后产生的细胞因子白细胞介素（IL）-1β通过促进中性粒细胞黏附和迁移，在中性粒细胞募集中起关键作用（麦克唐纳……，2010年）。本方案允许通过追踪髓过氧化物酶（MPO）活性来研究LPS诱导的影响中性粒细胞浸润的炎症反应（德阿尔梅达……，2015年）。
