miR-146a facilitates replication of dengue virus by dampening interferon induction by targeting TRAF6

• Published in: The Journal of infection Vol. 67; no. 4; pp. 329 - 341
• Main Authors: Wu, Siyu, He, Li, Li, Yuye, Wang, Tinglong, Feng, Lianqiang, Jiang, Lifang, Zhang, Ping, Huang, Xi
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01.10.2013; Elsevier
• Subjects: Biological and medical sciences; Blotting, Northern; Blotting, Western; Cells, Cultured; Dengue virus; Dengue Virus - immunology; Dengue Virus - physiology; Enzyme-Linked Immunosorbent Assay; Gene Expression Profiling; General aspects; Humans; Infectious Disease; Interferon; Interferon-beta - biosynthesis; Interferon-beta - immunology; Medical sciences; MicroRNA; MicroRNAs - genetics; MicroRNAs - metabolism; Monocytes - immunology; Monocytes - virology; Real-Time Polymerase Chain Reaction; Replication; TNF Receptor-Associated Factor 6 - antagonists & inhibitors; TNF Receptor-Associated Factor 6 - metabolism; TRAF6; Virus Replication; Replication; Interferon; MicroRNA; Dengue virus; TRAF6; Virus; Infection; Dengue group virus; Cytokine; Flaviviridae; Flavivirus
• ISSN: 0163-4453; 1532-2742
• DOI: 10.1016/j.jinf.2013.05.003

Summary Objectives To investigate the role of miR-146a in dengue virus (DENV) replication. Methods Expression levels of miR-146a were measured by real-time PCR and Northern blot. Role of miR-146a was tested by overexpression and inhibition assays. Real-time PCR and 50% tissue culture infective dose (TCID50) assays were used to detect RNA levels and extracellular yields of DENV respectively. Interferon (IFN) levels induced by DENV infection were measured by real-time PCR and ELISA respectively. IFN-β neutralization and RNAi were used to test the involvement of IFN-β in the effects of miR-146a. TNFR-associated factor 6 (TRAF6) level was measured by Western-blot. Results miR-146a expression was significantly increased in primary human monocytes and THP-1 cells upon DENV infection. Overexpression of miR-146a increased DENV2 replication, while inhibition of miR-146a decreased the viral replication. miR-146a impaired the IFN production and the DENV2 replication suppressed by miR-146a inhibition was partially restored by neutralization of IFN-β or depletion of interferon receptor (IFNAR) 1 or 2. Furthermore, miR-146a targets TRAF6 and overexpression of TRAF6 reversed the effects of miR-146a on IFN-β induction and viral replication. Conclusions DENV infection significantly induced the expression of miR-146a, which facilitated viral replication by targeting TRAF6 and dampening IFN-β production.