miR-927 has pro-viral effects during acute and persistent infection with dengue virus type 2 in C6/36 mosquito cells

• Published in: Journal of general virology 2020-08, Vol.101 (8), p.825-839
• Main Authors: Avila-Bonilla, Rodolfo Gamaliel, Yocupicio-Monroy, Martha, Marchat, Laurence A, Pérez-Ishiwara, David Guillermo, Cerecedo-Mercado, Doris Atenea, Del Ángel, Rosa María, Salas-Benito, Juan Santiago
• Format: Article
• Language: English
• Subjects: Aedes - genetics; Aedes - virology; Animals; Cell Line; Communicable Diseases - genetics; Communicable Diseases - virology; Dengue - virology; Dengue Virus - genetics; Genome, Viral - genetics; Luciferases - genetics; MicroRNAs - genetics; Virus Replication - genetics
• ISSN: 0022-1317; 1465-2099
• DOI: 10.1099/jgv.0.001441

Dengue virus (DENV) is an important flavivirus that is transmitted to humans by mosquitoes, where it can establish a persistent infection underlying vertical and horizontal transmission. However, the exact mechanism of persistent DENV infection is not well understood. Recently miR-927 was found to be upregulated in C6/36-HT cells at 57 weeks of persistent infection (C6-L57), suggesting its participation during this type of infection. The aim of this study was to determine the role of miR-927 during infection with DENV type 2. The results indicate an overexpression of miR-927 in C6-L57 cells and acutely infected cells according to the time of infection and the m.o.i. used. The downregulation of miR-927 in C6-L57 cells results in a reduction of both viral titre and viral genome copy number. The overexpression of miR-927 in C6-L40 and C6/36 cells infected at an m.o.i. of 0.1 causes an increase in both viral titre and viral genome copy number, suggesting a pro-viral activity of miR-927. prediction analysis reveals target mRNAs for miR-927 are implicated in post-translational modifications (SUMO), translation factors (eIF-2B), the innate immune system (NKIRAS), exocytosis (EXOC-2), endocytosis (APM1) and the cytoskeleton (FLN). The expression levels of FLN were the most affected by both miR-927 overexpression and inhibition, and FLN was determined to be a direct target of miR-927 by a dual-luciferase gene reporter assay. FLN has been associated with the regulation of the Toll pathway and either overexpression or downregulation of miR-927 resulted in expression changes of antimicrobial peptides (Cecropins A and G, and Defensin D) involved in the Toll pathway response.