DDX19 inhibits RLR/IRF3 mediated type I interferon signaling of black carp Mylopharyngodon piceus by restricting IRF3 from entering nucleus
DDX19 inhibits RLR/IRF3 mediated type I interferon signaling of black carp Mylopharyngodon piceus by restricting IRF3 from entering nucleus
复制标题
DOI：
10.1016/j.aquaculture.2022.738087
复制
发表时间：
2022-03-06
期刊：
影响因子：
4.5
通讯作者：
Feng，Hao
中科院分区：
文献类型：
--
作者：
Liu，Yankai;Xiao，Jun;Feng，Hao
DExD/H-box解旋酶家族成员是检测病毒核酸的重要受体。据报道，哺乳动物DExD/H-box RNA解旋酶19 （DDX19）是I型干扰素（IFN）的负调节因子。然而，硬骨鱼DDX19在先天免疫应答中的作用仍不清楚。本研究对黑鱼DDX19同源基因（bcDDX19）进行了克隆和鉴定。bcDDX19的开放阅读框（ORF）由1440个核苷酸组成，编码479个氨基酸。在免疫印迹实验中，bcDDX19迁移约54 kDa，并通过免疫荧光染色鉴定为胞质蛋白。qPCR结果显示，在脂多糖（LPS）、Poly （I:C）、鲤鱼病毒（SVCV）春季病毒血症或草鱼呼肠孤病毒（GCRV）刺激下，bcDDX19在宿主细胞中的转录水平升高。在报告的实验中，bcDDX19抑制bcIRF3-，但不抑制bcirf7介导的bcIFNa和DrIFNφ1启动子的转录活性。共免疫沉淀试验发现bcDDX19与bcIRF3相互作用，而不与bcIRF7相互作用。根据斑块分析结果显示，bcDDX19抑制了bcIRF3-而不是bcirf7诱导的EPC细胞的抗病毒活性。敲低bcDDX19可使宿主细胞bcIFNa、bcMx1和bcViperin mRNA水平升高，增强对SVCV的抗病毒能力。此外，当bcIRF3与bcDDX19共表达时，其核易位受到抑制。这些结果表明，bcDDX19通过限制IRF3进入细胞核，负调控RLR/IRF3介导的先天免疫激活中的I型IFN信号。
Members of DExD/H-box helicase family are important receptors for detecting viral nucleic acids. Mammalian DExD/H-box RNA helicase 19 (DDX19) has been reported to play as a negative regulator of type I interferon (IFN). However, the role of teleost DDX19 during the innate immune response is still obscure. In this study, the DDX19 homolog of black carp (bcDDX19) has been cloned and characterized. The open reading frame (ORF) of bcDDX19 consists of 1440 nucleotides and encodes contains 479 amino acids. bcDDX19 migrates around 54 kDa in immunoblotting assay and is identified as a cytosolic protein by immunofluorescence staining. The qPCR results show that the transcription of bcDDX19 in host cells rises in response to Lipopolysaccharide (LPS), Poly (I:C), spring viremia of carp virus (SVCV) or grass carp reovirus (GCRV) stimulation. In the report assay, bcDDX19 suppressed bcIRF3-, but not bcIRF7-mediated transcription activities of bcIFNa and DrIFNφ1 promoter. Co-immunoprecipitation assays identify that bcDDX19 interacts with bcIRF3 but not bcIRF7. According, plaque assay results demonstrate that bcDDX19 dampens bcIRF3- but not bcIRF7-induced antiviral activity of EPC cells. Knockdown of bcDDX19 offers host cells the increase of mRNA levels of bcIFNa, bcMx1 and bcViperin, and the improved antiviral ability against SVCV. In addition, the nuclear translocation of bcIRF3 is dampened when co-expressed with bcDDX19. All of these findings demonstrate that bcDDX19 negatively regulates RLR/IRF3 mediated type I IFN signaling in the innate immune activation through restricting IRF3 from entering nucleus.