背景:Viperin,也称为含S-腺苷-甲硫氨酸结构域的自由基蛋白2(RSAD2),是一种干扰素诱导蛋白,参与针对多种病毒的先天免疫反应。在哺乳动物中,Viperin通过将三磷酸胞苷(CTP)酶促转化为其抗病毒类似物ddhCTP以及通过与参与先天免疫信号传导和病毒在其生命周期中利用的代谢途径的宿主蛋白相互作用来发挥其抗病毒功能。然而,Viperin如何调节鱼类的抗病毒反应仍然是未知的。
结果:为此,我们开发了一种黑头小鱼(Pimephalespromelas)克隆细胞系,其中独特的viperin基因已被CRISPR/Cas9基因组编辑敲除。为了破译鱼类Viperin对抗病毒反应的贡献及其在先天免疫反应范围之外的调节作用,我们对Viperin-/-和野生型细胞系进行了比较RNA-seq分析,这些细胞系在用重组头小牛I型干扰素刺激后.
结论:我们的结果表明,Viperin对典型的I型IFN不产生正反馈,而是通过下调特定的促炎基因和上调NF-κB途径的阻遏因子而充当炎症反应的负调节因子。它似乎也在调节代谢过程中发挥作用,包括一种碳代谢,骨形成,细胞外基质组织和细胞粘附。
BACKGROUND: Viperin, also known as radical S-adenosyl-methionine domain containing protein 2 (RSAD2), is an interferon-inducible protein that is involved in the innate immune response against a wide array of viruses. In mammals, Viperin exerts its antiviral function through enzymatic conversion of cytidine triphosphate (CTP) into its antiviral analog ddhCTP as well as through interactions with host proteins involved in innate immune signaling and in metabolic pathways exploited by viruses during their life cycle. However, how Viperin modulates the antiviral response in fish remains largely unknown.
RESULTS: For this purpose, we developed a fathead minnow (Pimephales promelas) clonal cell line in which the unique viperin gene has been knocked out by CRISPR/Cas9 genome-editing. In order to decipher the contribution of fish Viperin to the antiviral response and its regulatory role beyond the scope of the innate immune response, we performed a comparative RNA-seq analysis of viperin-/- and wildtype cell lines upon stimulation with recombinant fathead minnow type I interferon.
CONCLUSIONS: Our results revealed that Viperin does not exert positive feedback on the canonical type I IFN but acts as a negative regulator of the inflammatory response by downregulating specific pro-inflammatory genes and upregulating repressors of the NF-κB pathway. It also appeared to play a role in regulating metabolic processes, including one carbon metabolism, bone formation, extracellular matrix organization and cell adhesion.