Department of Molecular and Comparative Pathobiology, Edward D, Miller Research Building, The Johns Hopkins University School of Medicine, 733 N Broadway, Baltimore, MD 21205, USA.
Retrovirology. 2013 Aug 29;10:95. doi: 10.1186/1742-4690-10-95.
Host cell microRNAs (miRNAs) have been shown to regulate the expression of both cellular and viral RNAs, in particular impacting both Hepatitis C Virus (HCV) and Human Immunodeficiency Virus (HIV). To investigate the role of miRNAs in regulating replication of the simian immunodeficiency virus (SIV) in macrophage lineage cells, we used primary macrophages to study targeting of SIV RNA by miRNAs. We examined whether specific host miRNAs directly target SIV RNA early in infection and might be induced via type I interferon pathways.
miRNA target prediction programs identified miRNA binding sites within SIV RNA. Predicted binding sites for miRs-29a, -29b, -9 and -146a were identified in the SIV Nef/U3 and R regions, and all four miRNAs decreased virus production and viral RNA expression in primary macrophages. To determine whether levels of these miRNAs were affected by SIV infection, IFNβ or TNFα treatments, miRNA RT-qPCR assays measured miRNA levels after infection or treatment of macrophages. SIV RNA levels as well as virus production was downregulated by direct targeting of the SIV Nef/U3 and R regions by four miRNAs. miRs-29a, -29b, -9 and -146a were induced in primary macrophages after SIV infection. Each of these miRNAs was regulated by innate immune signaling through TNFα and/or the type I IFN, IFNβ.
The effects on miRNAs caused by HIV/SIV infection are illustrated by changes in their cellular expression throughout the course of disease, and in different patient populations. Our data demonstrate that levels of primary transcripts and mature miRs-29a, -29b, -9 and -146a are modulated by SIV infection. We show that the SIV 3' UTR contains functional miRNA response elements (MREs) for all four miRNAs. Notably, these miRNAs regulate virus production and viral RNA levels in macrophages, the primary cells infected in the CNS that drive inflammation leading to HIV-associated neurocognitive disorders. This report may aid in identification miRNAs that target viral RNAs and HIV/SIV specifically, as well as in identification of miRNAs that may be targets of new therapies to treat HIV.
宿主细胞 microRNAs（miRNAs）已被证明可以调节细胞和病毒 RNA 的表达，特别是影响丙型肝炎病毒（HCV）和人类免疫缺陷病毒（HIV）。为了研究 miRNAs 在调节巨噬细胞谱系细胞中猴免疫缺陷病毒（SIV）复制中的作用，我们使用原代巨噬细胞研究了 miRNAs 对 SIV RNA 的靶向作用。我们研究了特定的宿主 miRNAs 是否在感染早期直接靶向 SIV RNA，并且是否可以通过 I 型干扰素途径诱导。
miRNA 靶标预测程序确定了 SIV RNA 中的 miRNA 结合位点。在 SIV Nef/U3 和 R 区鉴定了预测结合 miR-29a、-29b、-9 和 -146a 的位点，这四种 miRNA 均降低了原代巨噬细胞中的病毒产生和病毒 RNA 表达。为了确定这些 miRNA 的水平是否受 SIV 感染、IFNβ 或 TNFα 治疗的影响，miRNA RT-qPCR 测定在感染或巨噬细胞处理后测量了 miRNA 水平。SIV RNA 水平以及病毒产生通过 SIV Nef/U3 和 R 区的四种 miRNA 的直接靶向被下调。miR-29a、-29b、-9 和 -146a 在 SIV 感染后在原代巨噬细胞中被诱导。这些 miRNA 中的每一种都通过 TNFα 和/或 I 型 IFN IFNβ 调节先天免疫信号。
HIV/SIV 感染引起的 miRNA 变化说明了它们在疾病过程中的细胞表达以及不同患者群体中的变化。我们的数据表明，miR-29a、-29b、-9 和 -146a 的初级转录物和成熟物的水平受 SIV 感染的调节。我们表明，SIV 3'UTR 包含针对所有四种 miRNA 的功能性 miRNA 反应元件（MRE）。值得注意的是，这些 miRNA 调节巨噬细胞中的病毒产生和病毒 RNA 水平，巨噬细胞是中枢神经系统中感染的主要细胞，可引发导致 HIV 相关神经认知障碍的炎症。本报告可能有助于鉴定靶向病毒 RNA 和 HIV/SIV 的特定 miRNA，以及鉴定可能成为治疗 HIV 的新疗法的靶标的 miRNA。
