Schirtzinger Erin E, Andrade Christy C, Devitt Nicholas, Ramaraj Thiruvarangan, Jacobi Jennifer L, Schilkey Faye, Hanley Kathryn A
Department of Biology, New Mexico State University, Las Cruces, NM, USA.
National Center for Genome Resources (NCGR), Santa Fe, NM, USA.
Virology. 2015 Feb;476:54-60. doi: 10.1016/j.virol.2014.11.019. Epub 2014 Dec 17.
RNA interference (RNAi) is the major defense of many arthropods against arthropod-borne RNA viruses (arboviruses), but the role of RNAi in vertebrate immunity to arboviruses is not clear. RNA viruses can trigger RNAi in vertebrate cells, but the vertebrate interferon response may obscure this interaction. We quantified virus-derived small RNAs (vRNAs) generated by mosquito (U4.4) cells and interferon-deficient (Vero) and interferon-competent (HuH-7) mammalian cells infected with a single isolate of mosquito-borne dengue virus. Mosquito cells produced significantly more vRNAs than mammalian cells, and mosquito cell vRNAs were derived from both the positive- and negative-sense dengue genomes whereas mammalian cell vRNAs were derived primarily from positive-sense genome. Mosquito cell vRNAs were predominantly 21 nucleotides in length whereas mammalian cell vRNAs were between 12 and 36 nucleotides with a modest peak at 24 nucleotides. Hot-spots, regions of the virus genome that generated a disproportionate number of vRNAs, overlapped among the cell lines.
RNA干扰（RNAi）是许多节肢动物抵御节肢动物传播的RNA病毒（虫媒病毒）的主要防御机制，但RNAi在脊椎动物对虫媒病毒免疫中的作用尚不清楚。RNA病毒可在脊椎动物细胞中触发RNAi，但脊椎动物的干扰素反应可能会掩盖这种相互作用。我们对感染单一分离株蚊媒登革病毒的蚊子（U4.4）细胞、缺乏干扰素的（Vero）和具有干扰素活性的（HuH-7）哺乳动物细胞产生的病毒衍生小RNA（vRNA）进行了定量。蚊子细胞产生的vRNA比哺乳动物细胞多得多，蚊子细胞的vRNA来自登革病毒基因组的正链和负链，而哺乳动物细胞的vRNA主要来自正链基因组。蚊子细胞的vRNA长度主要为21个核苷酸，而哺乳动物细胞的vRNA长度在12至36个核苷酸之间，在24个核苷酸处有一个适度的峰值。病毒基因组中产生不成比例数量vRNA的热点区域在细胞系之间重叠。
