Bi Dekun, Gao Yunhang, Chu Qing, Cui Junxia, Xu Tianjun
Laboratory of Fish Biogenetics & Immune Evolution, College of Marine Science, Zhejiang Ocean University, Zhoushan, 316022, China.
Laboratory of Fish Biogenetics & Immune Evolution, College of Marine Science, Zhejiang Ocean University, Zhoushan, 316022, China.
Dev Comp Immunol. 2017 Nov;76:238-246. doi: 10.1016/j.dci.2017.06.012. Epub 2017 Jun 24.
The innate immune system is the first line for organisms defense against microbial infection, and NOD-like receptors (NLRs) protein family is an important member of innate immunity effector molecules. It has been proved that NLRs are located in the endochylema and can senses of microbial products. NOD1 is one of the representatives of this family, it has been proved that in mammals, NOD1 can distinguish a specific muropeptide (G-d-glutamyl-meso-diaminopimelic acid, iE-DAP) which was derived from bacterial peptidoglycans. However, the NOD-mediated intracellular recognition of microorganisms remains largely uncharacterized in teleost fishes. In this study, we use miiuy croaker (Miichthys miiuy) as a model to determine NOD1 can response to the infection of Gram-negative bacteria and it is the receptor that can recognize of iE-DAP by LRRs domain, it can activate the NF-κB signaling pathway through recruit RIP2 to induce inflammatory response in teleost fishes. Results showed that NOD1 can recognize the components of Gram-negative bacteria and activate inflammatory response to resistance of bacterial infection. Our study can improve the knowledge on immune system of fishes and provide a theoretical basis for the study of prevention and treatment of fish diseases.
天然免疫系统是生物体抵御微生物感染的第一道防线，而NOD样受体（NLRs）蛋白家族是天然免疫效应分子的重要成员。已证实NLRs位于胞浆内，能够感知微生物产物。NOD1是该家族的代表之一，已证实在哺乳动物中，NOD1能够识别一种源自细菌肽聚糖的特定胞壁肽（γ - D - 谷氨酰 - 内消旋二氨基庚二酸，iE - DAP）。然而，在硬骨鱼类中，NOD介导的对微生物的细胞内识别在很大程度上仍未得到充分研究。在本研究中，我们以真鲷（Miichthys miiuy）为模型，确定NOD1能够对革兰氏阴性菌感染作出反应，并且它是通过富含亮氨酸重复序列（LRRs）结构域识别iE - DAP的受体，它能够通过招募RIP2激活NF - κB信号通路，从而在硬骨鱼类中诱导炎症反应。结果表明，NOD1能够识别革兰氏阴性菌的成分并激活炎症反应以抵抗细菌感染。我们的研究能够增进对鱼类免疫系统的了解，并为鱼类疾病防治研究提供理论依据。
