Zhao Wan, Li Qiong, Sun Mengqi, Luo Lan, Zhang Xiaoming, Cui Feng
State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China.
PLoS Pathog. 2025 Jan 3;21(1):e1012789. doi: 10.1371/journal.ppat.1012789. eCollection 2025 Jan.
Virus-derived small interfering RNAs (vsiRNAs) have been widely recognized to play an antiviral immunity role. However, it is unclear whether vsiRNAs can also play a positive role in viral infection. Here, we characterized three highly abundant vsiRNAs mapped to the genomic termini of rice stripe virus (RSV), a negative-strand RNA virus transmitted by insect vectors. The three vsiRNAs shared 11 nucleotides due to the conservative genomic termini and were likely generated from viral terminal panhandle structure, depending on both Dicer1 and Dicer2 in insects. In addition to targeting viral RNAs in a miRNA-like manner, the three vsiRNAs coordinately downregulated the expression of DOPA decarboxylase, thereby suppressing the prophenoloxidase immune reaction in insect vectors. In vsiRNA-silenced transgenic rice, the viral titer significantly decreased, indicating that these vsiRNAs promote RSV replication in rice. This study elucidates a unique function of vsiRNAs derived from the conserved panhandle structure of negative-strand RNA viruses in enhancing viral infection.
病毒衍生的小干扰RNA（vsiRNA）已被广泛认为具有抗病毒免疫作用。然而，尚不清楚vsiRNA是否也能在病毒感染中发挥积极作用。在此，我们鉴定了三种高度丰富的vsiRNA，它们定位于水稻条纹病毒（RSV）的基因组末端，RSV是一种由昆虫载体传播的负链RNA病毒。由于保守的基因组末端，这三种vsiRNA共享11个核苷酸，并且可能源自病毒末端柄状结构，这取决于昆虫中的Dicer1和Dicer2。除了以类似miRNA的方式靶向病毒RNA外，这三种vsiRNA还协同下调多巴脱羧酶的表达，从而抑制昆虫载体中的酚氧化酶免疫反应。在vsiRNA沉默的转基因水稻中，病毒滴度显著降低，表明这些vsiRNA促进RSV在水稻中的复制。本研究阐明了源自负链RNA病毒保守柄状结构的vsiRNA在增强病毒感染方面的独特功能。
