病毒感染过程中青鳉irf2基因过表达的双面性

为了探究干扰素调节因子2 (interferon regulatory factor,IRF2)如何通过调控干扰素(IFN)表达影响鱼类的免疫,实验从青鳉中克隆了irf2 (Olirf2),发现该基因在青鳉各个组织中均有表达;将构建的真核表达载体pTol2/CMV-IRF2/IE1-pr转染到胖头鱥肌肉细胞系(FHM)后,发现瞬时过表达Olirf2能够显著促进鲤春病毒血症病毒(spring viremia of carp virus,SVCV)的复制,并抑制抗病毒相关基因mx1、ifn和irf3的表达。进一步通过双荧光素报告系统发现,Olirf2能够显著抑制NF-κB和ISRE的活性,说明Olirf2可能通过抑制细胞的天然免疫应答进而促进病毒的增殖。然而持续过表达Olirf2则增强了细胞的抗病毒能力,同时促进干扰素相关基因mx1、ifn和irf3的表达。因此,Olirf2基于表达的持续时间不同而具有抗病毒或者促病毒的双面效果。实验通过研究Olirf2在抗病毒信号通路中发挥的作用,为通过基因编辑或者转基因手段来构建抗病毒的鱼类提供了理论基础。

Dual characters of overexpressed Medaka (Oryzias latipes) interferon regulatory factor 2 gene during virus infection

Interferon (IFN)-mediated antiviral signaling pathway is a very important part of fish innate immune response, and interferon regulatory factor 2 (IRF2) can affect fish immunity by regulating the expression of IFN. Therefore, this experiment studied the role of medaka irf2 (Olirf2) in the antiviral signal pathway, which may provide a theoretical basis for antiviral fish through gene editing or genetic modification. In this study, the Olirf2 was cloned, and RNA expression was detected in adult tissues. Moreover, the plasmid pTol2/CMV-IRF2/IE1-pr was constructed by cloning the coding sequence of Olirf2 for eukaryotic expression. In fish cell line FHM, transient expression of Olirf2 promoted the replication of spring viremia of carp virus (SVCV) and reduced the expression of mx1, ifn and irf3 significantly. Further studies by luciferase reporter assay showed that Olirf2 inhibited promoter activities of SVCV-induced NF-κB and ISRE, indicating that Olirf2 may promote the replication of SVCV by inhibiting cellular innate immune response. However, constant overexpression of Olirf2 enhanced the antiviral ability in FHM and increased the expression levels of mx1, ifn and irf3. Therefore, the current research suggested that the Olirf2 has double effect to regulate the antiviral effect based on the duration of expression.