Lnc-ISG20 Inhibits Influenza A Virus Replication by Enhancing ISG20 Expression
Lnc-ISG20 Inhibits Influenza A Virus Replication by Enhancing ISG20 Expression
复制标题
Lnc-ISG20 通过增强 ISG20 表达来抑制甲型流感病毒复制。
DOI：
10.1128/jvi.00539-18
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发表时间：
2018-08-01
影响因子：
5.4
通讯作者：
Ye, Xin
中科院分区：
文献类型：
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作者：
Chai, Wenjia;Li, Jing;Ye, Xin
长非编码 RNA (lncRNA) 参与细胞过程的许多方面，包括抗病毒免疫反应。为了鉴定甲型流感病毒（IAV）相关的lncRNA，我们进行了RNA深度测序，以比较有或没有IAV感染的A549和HEK293T细胞中lncRNA的概况。我们鉴定了一种 IAV 上调的 lncRNA，命名为 lnc-ISG20，因为它与 ISG20 共享大部分序列。我们发现lnc-ISG20是一个与ISG20类似的干扰素刺激基因。 lnc-ISG20的过表达抑制IAV复制，而lnc-ISG20敲低有利于病毒复制，表明lnc-ISG20抑制IAV复制。进一步的研究表明，在聚（I.C）和仙台病毒诱导的A549细胞中，lnc-ISG20的过表达可增强ISG20蛋白水平，而lnc-ISG20的敲低可降低ISG20蛋白水平。我们证明 lnc-ISG20 以 ISG20 依赖性方式抑制 IAV 复制。由于lnc-ISG20不影响ISG20的mRNA水平，我们推测lnc-ISG20可能作为内源RNA与ISG20竞争以增强其翻译。事实上，我们发现 microRNA 326 (miR-326) 是 ISG20 和 lnc-ISG20 的共同 microRNA，它靶向 ISG20 mRNA 的 3' 非翻译区以抑制其翻译。我们证实lnc-ISG20可以结合miR-326，这反过来又减少了miR-326与ISG20 mRNA结合的量。总之，我们发现 IAV 上调的 lnc-ISG20 是一种新型干扰素刺激基因，通过增强 ISG20 表达来抑制 IAV 复制。我们证明lnc-ISG20作为竞争性内源RNA结合miR-326以减少其对ISG20翻译的抑制。我们的结果揭示了 lnc-ISG20 抑制 IAV 复制的机制。重要性 甲型流感病毒的复制受宿主因素调节。然而，lncRNA 调节 IAV 感染的机制尚不清楚。我们发现lnc-ISG20在IAV感染期间上调，并且也是干扰素刺激的基因。我们证明lnc-ISG20可以增强ISG20的表达，从而抑制IAV复制。我们的研究表明，lnc-ISG20 作为竞争性内源 RNA 发挥作用，与 miR-326 结合并降低其对 ISG20 的抑制作用。综上所述，我们的研究结果揭示了 lnc-ISG20 负向调节 IAV 复制的机制细节。这些发现表明lncISG20在宿主抗病毒免疫反应中发挥着重要作用。
Long noncoding RNAs (lncRNAs) are involved in many aspects of cellular processes, including the antiviral immune response. To identify influenza A virus (IAV)-related lncRNAs, we performed RNA deep sequencing to compare the profiles of lncRNAs in A549 and HEK293T cells with or without IAV infection. We identified an IAV-upregulated lncRNA named lnc-ISG20 because it shares most of its sequence with ISG20. We found that lnc-ISG20 is an interferon-stimulated gene similar to ISG20. Overexpression of lnc-ISG20 inhibited IAV replication, while lnc-ISG20 knockdown favored viral replication, suggesting that lnc-ISG20 is inhibitory to IAV replication. Further study indicated that overexpression of lnc-ISG20 enhances ISG20 protein levels, while knockdown of lnc-ISG20 reduces ISG20 protein levels in A549 cells induced with poly(I.C) and Sendai virus. We demonstrated that lnc-ISG20 inhibits IAV replication in an ISG20-dependent manner. As lnc-ISG20 did not affect the mRNA level of ISG20, we postulated that lnc-ISG20 may function as endogenous RNA competing with ISG20 to enhance its translation. Indeed, we identified that microRNA 326 (miR-326) is a mutual microRNA for both ISG20 and lnc-ISG20 that targets the 3' untranslated region of ISG20 mRNA to inhibit its translation. We confirmed that lnc-ISG20 can bind miR-326, which in turn decreased the amount of miR-326 bound to ISG20 mRNA. In conclusion, we identified that the IAV-upregulated lnc-ISG20 is a novel interferon-stimulated gene that elicits its inhibitory effect on IAV replication by enhancing ISG20 expression. We demonstrated that lnc-ISG20 functions as a competitive endogenous RNA to bind miR-326 to reduce its inhibition of ISG20 translation. Our results revealed the mechanism by which lnc-ISG20 inhibits IAV replication. IMPORTANCE The replication of influenza A virus is regulated by host factors. However, the mechanisms by which lncRNAs regulate IAV infection are not well understood. We identified that lnc-ISG20 is upregulated during IAV infection and is also an interferon-stimulated gene. We demonstrated that lnc-ISG20 can enhance ISG20 expression, which in turn inhibits IAV replication. Our studies indicate that lnc-ISG20 functions as a competing endogenous RNA that binds miR-326 and reduces its inhibitory effect on ISG20. Taken together, our findings reveal the mechanistic details of lnc-ISG20 negatively regulating IAV replication. These findings indicate that lncISG20 plays an important role during the host antiviral immune response.