Peptidoglycan, not endotoxin, is the key mediator of cytokine gene expression induced in rainbow trout macrophages by crude LPS
Peptidoglycan, not endotoxin, is the key mediator of cytokine gene expression induced in rainbow trout macrophages by crude LPS
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DOI：
10.1016/j.molimm.2010.02.009
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发表时间：
2010-04-01
影响因子：
3.6
通讯作者：
Goetz, Frederick W.
中科院分区：
文献类型：
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作者：
MacKenzie, Simon A.;Roher, Nerea;Goetz, Frederick W.
在虹鱼巨噬细胞中，苯酚提取的脂多糖(LPS)制剂可刺激促炎细胞因子基因的表达，而超纯的LPS制剂则不起作用。粗制的脂多糖制剂可能含有许多污染物，包括肽多聚糖(PGN)、核酸和脂蛋白。因此，在当前的研究中，我们分别测试了虹鱼(Oncorhynchus MykISS)巨噬细胞上的潜在污染性病原体相关分子模式(PAMPs)，以确定哪些PAMP可以诱导促炎细胞因子的表达。我们发现，来自革兰氏阴性菌(Escherichia coli0111：B4和K12)的PGN是IL-1β和IL-6基因表达的有效诱导剂，与粗脂多糖相当或更强。革兰氏阳性菌的PGN、DNA、RNA和脂磷壁酸为弱刺激性，脂蛋白A、脂蛋白(Pam3CSK4)和超纯脂多糖无刺激性。更重要的是，经溶菌酶处理的粗脂多糖降解PGNS的活性显著降低，刺激IL-1β和IL-6基因表达的活性显著降低，表明粗脂多糖中的PGNS参与了大量的促炎活性。最后，我们发现PGN治疗诱导COX-2的表达，以及随后合成和释放炎症过程的重要介质前列腺素E-2(PGE(2))。大肠杆菌PGNS本身对鲑鱼巨噬细胞的强烈刺激作用表明，鲑鱼对革兰氏阴性菌的识别是通过细菌壁上的PGNS实现的，这表明负责无脊椎动物(如果蝇)细菌识别的系统在一些脊椎动物中也可能是保守的。(C)2010爱思唯尔有限公司。保留所有权利。
In rainbow trout macrophages, phenol-extracted lipopolysaccharide (LPS) preparations stimulate proinflammatory cytokine gene expression but ultrapure preparations of LPS are inactive. Crude LPS preparations could potentially have a number of contaminants including peptidoglycans (PGNs), nucleic acids and lipoproteins. Thus, in the current study we individually tested potentially contaminating pathogen associated molecular patterns (PAMPs) on rainbow trout (Oncorhynchus mykiss) macrophages to determine which ones could induce proinflammatory cytokine expression. We found that PGNs derived from Gram-negative bacteria (Escherichia coli 0111:B4 and K12), are potent inducers of IL-1 beta and IL-6 gene expression and were equal to, or more potent than, crude LPS. On the other hand, PGNs of Gram-positive bacteria, DNA, RNA and lipoteichoic acid were weak stimulators, and lipid A, lipoprotein (Pam3CSK4) and ultrapure LPS were nonstimulatory. More importantly, crude LPS treated with lysozyme to degrade PGNs, exhibited greatly reduced activity in stimulating IL-1 beta and IL-6 gene expression, indicating that PGNs in the crude LPS are responsible for a significant amount of the proinflammatory activity. Finally, we showed that PGN treatment induces expression of COX-2 and the subsequent synthesis and release of prostaglandin E-2 (PGE(2)), an important mediator of inflammatory processes. The strong stimulatory effect of E. coli PGNs by themselves on trout macrophages suggests that the recognition of Gram-negative bacteria in trout is through PGNs in the bacterial wall, and indicates that the systems responsible for bacterial recognition in invertebrates (e.g., Drosophila) may also be conserved in some vertebrates. (C) 2010 Elsevier Ltd. All rights reserved.