Chen Jing, Shi Xibao, Zhang Xiaozhuan, Wang Li, Luo Jun, Xing Guangxu, Deng Ruiguang, Yang Hong, Li Jinting, Wang Aiping, Zhang Gaiping
College of Animal Science and Veterinary Medicine, Jilin University, Changchun 130062, China.
Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China.
Viruses. 2015 Oct 23;7(10):5539-52. doi: 10.3390/v7102893.
Porcine reproductive and respiratory syndrome virus (PRRSV) infection strongly modulates the host's immune response. The RNA silencing pathway is an intracellular innate response to viral infections. However, it is unknown whether PRRSV interacts with cellular RNA silencing to facilitate the viral infection. Here, we report for the first time the interaction between PRRSV and RNA silencing in both the porcine macrophages and African green monkey kidney cell line (MARC-145) cell line, which were derived from African green monkey kidney cells and highly permissive for PRRSV infection. Our data demonstrated that PRRSV suppressed RNA silencing induced by short-hairpin (sh) RNA, double-strand (ds) RNA and microRNA (miRNA) and downregulated the expression of argonaute protein-2 (Ago-2), which is a key protein of the RNA silencing pathway in animal cells. Further, exogenous introduction of siRNA and shRNA downregulated Dicer or Ago-2 proteins of the cellular RNA silencing apparatus in MARC-145 cells and porcine macrophages, which, in turn, increased the viral replication and titers. The viral non-structure protein 1α (nsp-1α) and nsp11 of PRRSV were identified as the suppressors for cellular RNA silencing (RSSs) to downregulate the Ago-2 protein. Our results identify that PRRSV, through its nsp proteins, suppresses the cellular RNA silencing apparatus in favor of viral infection and supports a co-evolutionary process of the virus and the cellular RNA silencing process.
猪繁殖与呼吸综合征病毒（PRRSV）感染会强烈调节宿主的免疫反应。RNA沉默途径是细胞对病毒感染的一种先天性细胞内反应。然而，PRRSV是否与细胞RNA沉默相互作用以促进病毒感染尚不清楚。在此，我们首次报道了PRRSV与RNA沉默在猪巨噬细胞和源自非洲绿猴肾细胞且对PRRSV感染高度敏感的非洲绿猴肾细胞系（MARC - 145）细胞系中的相互作用。我们的数据表明，PRRSV抑制了由短发夹（sh）RNA、双链（ds）RNA和微小RNA（miRNA）诱导的RNA沉默，并下调了动物细胞RNA沉默途径的关键蛋白——AGO2蛋白的表达。此外，在MARC - 145细胞和猪巨噬细胞中外源导入小干扰RNA（siRNA）和短发夹RNA（shRNA）会下调细胞RNA沉默装置中的Dicer或AGO2蛋白，这反过来又增加了病毒的复制和滴度。PRRSV的病毒非结构蛋白1α（nsp - 1α）和nsp11被鉴定为细胞RNA沉默（RSS）的抑制剂，可下调AGO2蛋白。我们的结果表明，PRRSV通过其nsp蛋白抑制细胞RNA沉默装置以利于病毒感染，并支持病毒与细胞RNA沉默过程的共同进化过程。
