[Objective]Tembusu virus(TMUV)disease is an important infectious disease in waterfowl.In previous studies,we found that in the early stages of TMUV infection in ducks,the viral copy number of group 2 TMUV in organs such as the liver,kidney,and brain were significantly higher than those of group 3 TMUV.The study aimed to explore whether group 2 TMUV NS proteins had different effects on the innate immune response of ducks compared with group 3 TMUV.[Method]Taking the group 2 TMUV-JM strain and the group 3 TMUV-GX strain as research subjects,we constructed the eukaryotic expression plasmids of NS proteins of the two strains and compared the effects of the NS proteins on the RIG-I-induced activity of the IFN-β(Type I)promoter by a dual-Luciferase reporter system.With the eukaryotic expression plasmids of the constructed recombinant chimeric NS1 proteins,we investigated the interaction region between NS1 and the key molecules of RIG-I signaling pathway by confocal laser scanning microscopy,co-IP and Western Blotting.By using the reverse genetic system,we constructed NS1 recombinant chimeric TMUV to clarify the inhibitory effect of NS1 on the IFN-β in DEF cells with TMUV infection.[Result]The study results showed that TMUV-JM NS1 could inhibit RIG-I-induced activation of the IFN-β promoter,while TMUV-GX NS1 did not exhibit the inhibitory activity.Further studies revealed that the TMUV-JM NS1 inhibited the expression of type I IFN via targeting TBK1,and the NS1 255-352 aa was the functional region of the inhibitory effect.It was found that TMUV-JM NS1 did not interact with TBK1 directly,but reduced the phosphorylation level of TBK1 indirectly,thereby suppressed the expression of type I IFN.[Conclusion]Based on the study results,we found that the group 2 TMUV NS1 has activity in inhibiting the RIG-I signaling pathway,identified the key activity region and targeted molecule of its inhibitory pathway,and clarified that group 2 TMUV NS1 affected duck type I IFN production by indirectly inhibiting the phosphorylation of TBK1.
关键词
坦布苏病毒/非结构蛋白/RIG-I信号通路/I型干扰素/TBK1磷酸化
Key words
Tembusu virus/non-structural protein/RIG-I signaling pathway/type I interferon/TBK1 phosphorylation
维普
万方数据