Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, Fujian, PR China.
State Key Laboratory of Large Yellow Croaker Breeding, Ningde, Fujian, 352000, PR China.
Fish Shellfish Immunol. 2020 Feb;97:564-570. doi: 10.1016/j.fsi.2019.12.084. Epub 2019 Dec 28.
Aryl hydrocarbon receptor (AhR), a ligand-dependent transcriptional factor that responds to environmental chemicals, has been recently found to be closely associated with immune response in mammals. Pseudomonas plecoglossicida (P. plecoglossicida) is a temperature-dependent bacterial pathogen of visceral white spot disease in fish. Using dual RNA-seq, we previously evaluated the expression levels of ahr1a, ahr1b, ahr2 and cyp1a in the spleen of Epinephelus coioides at different time points after infection with P. plecoglossicida. In the present study, the expression levels of ahr1a, ahr1b, ahr2 and cyp1a in different organs of E. coioides and Danio rerio showed similar trends after being infected by P. plecoglossicida. It also was noted that liver, intestine, spleen, and heart were the most obviously affected organs, and ahr2 particularly showed a dramatically increase in the spleen. Subsequently, macrophages of E. coioides were isolated, and then infected by P. plecoglossicida, followed by quantitative reverse transcription polymerase chain reaction (qRT-PCR) assay, which revealed that the expression level of ahr1a in macrophages was significantly down-regulated, while expression levels of ahr1b, ahr2 and cyp1a were noticeably up-regulated. Eventually, it was noted that ahr1b and ahr2 were knocked-down in macrophages, and intracellular survival rate and immune escape rate of P. plecoglossicida were markedly improved. Taken together, ahr1a, ahr1b, ahr2 and cyp1a participate in the immune response to P. plecoglossicida in different organs of fish, while ahr1b and ahr2 may play pivotal roles in the immune response of spleen and macrophages.
芳香烃受体（AhR）是一种配体依赖性转录因子，对环境化学物质有反应，最近发现它与哺乳动物的免疫反应密切相关。荧光假单胞菌（P. plecoglossicida）是鱼类内脏白点病的一种温度依赖性细菌病原体。我们之前使用双 RNA-seq 评估了感染 P. plecoglossicida 后不同时间点石斑鱼脾脏中 ahr1a、ahr1b、ahr2 和 cyp1a 的表达水平。在本研究中，感染 P. plecoglossicida 后，不同器官中 E. coioides 和 D. rerio 的 ahr1a、ahr1b、ahr2 和 cyp1a 的表达水平表现出相似的趋势。还注意到肝脏、肠道、脾脏和心脏是受影响最明显的器官，ahr2 在脾脏中表现出明显增加。随后，分离出石斑鱼巨噬细胞，然后用 P. plecoglossicida 感染，随后进行定量逆转录聚合酶链反应（qRT-PCR）检测，结果显示巨噬细胞中 ahr1a 的表达水平显著下调，而 ahr1b、ahr2 和 cyp1a 的表达水平明显上调。最后，发现巨噬细胞中 ahr1b 和 ahr2 被敲低，荧光假单胞菌的细胞内存活率和免疫逃逸率明显提高。总之，ahr1a、ahr1b、ahr2 和 cyp1a 参与鱼类不同器官对 P. plecoglossicida 的免疫反应，而 ahr1b 和 ahr2 可能在脾脏和巨噬细胞的免疫反应中发挥关键作用。
