Key Laboratory for Sustainable Utilization of Marine Fisheries Resources, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, 106 Nanjing Road, Qingdao 266071, China.
Fish Shellfish Immunol. 2012 Oct;33(4):1033-41. doi: 10.1016/j.fsi.2012.06.033. Epub 2012 Jul 13.
NLRs are a large family of intracellular pathogen recognition receptors (PRRs) that recognize pathogen associated molecular patterns (PAMPs). In the previous study, the identification of NLRs subfamily A (NODs) and gene expression was carried out in channel catfish (Ictalurus punctatus). However, the gene expression profiles of channel catfish NODs (NOD1, NOD2, NLRC3, NLRC5 and NLRX1) after infection with various bacteria and virus are still unclear. In this study, expression of five NODs genes was analyzed by quantitative real-time PCR method. In healthy catfish tissues, all tested NODs genes were found to be ubiquitously expressed. After infection with Edwardsiella tarda, Aeromonas hydrophila, Streptococcus iniae, or channel catfish hemorrhage reovirus (CCRV), expression of NOD1, NOD2, NLRC3, NLRC5 showed a significant up-regulation in the intestine, liver and head kidney, whereas down-regulation was observed in the spleen after infection with A. hydrophila and CCRV. Expression of NLRX1 gene was up-regulated in the intestine, liver and head kidney, while obviously decreased in the spleen after infection with four pathogens. Among four different pathogens, S. iniae largely up-regulated NODs mRNAs, while CCRV only slightly enhanced NODs gene expression. Among four immune-related tissues, the order for NODs up-regulation was liver, head kidney, intestine, and spleen after infection with various pathogens. All data suggest NODs are involved in the immune responses of channel catfish against the intracellular bacterial and virus pathogens in tissue-specific and pathogen-specific manners, and provide the evidence for exploring the precise immune-related molecular mechanism of NODs in channel catfish.
NLRs 是一类能够识别病原体相关分子模式（PAMPs）的胞内病原体识别受体（PRRs）大家族。在之前的研究中，已经在斑点叉尾鮰（Ictalurus punctatus）中鉴定了 NLRs 亚家族 A（NODs）和基因表达。然而，在感染各种细菌和病毒后，斑点叉尾鮰 NODs（NOD1、NOD2、NLRC3、NLRC5 和 NLRX1）的基因表达谱仍不清楚。在本研究中，采用定量实时 PCR 方法分析了这 5 个 NOD 基因的表达情况。在健康的斑点叉尾鮰组织中，所有被检测到的 NOD 基因均广泛表达。在感染迟钝爱德华氏菌、嗜水气单胞菌、链球菌和斑点叉尾鮰出血性肠病毒（CCRV）后，NOD1、NOD2、NLRC3、NLRC5 的表达在肠、肝和头肾中显著上调，而在感染嗜水气单胞菌和 CCRV 后，脾脏中的表达下调。NLRX1 基因的表达在肠、肝和头肾中上调，而在感染四种病原体后，脾脏中的表达明显下降。在四种不同的病原体中，链球菌大量上调 NODs mRNAs 的表达，而 CCRV 仅轻微增强 NODs 基因的表达。在四种免疫相关组织中，感染各种病原体后 NODs 的上调顺序为肝、头肾、肠和脾。所有数据表明，NODs 参与了斑点叉尾鮰对组织特异性和病原体特异性的胞内细菌和病毒病原体的免疫反应，为探索斑点叉尾鮰 NODs 精确的免疫相关分子机制提供了证据。
