Cell fusing agent virus and dengue virus mutually interact in Aedes aegypti cell lines

• Published in: Scientific reports Vol. 7; no. 1; pp. 6935 - 8
• Main Authors: Zhang, Guangmei, Asad, Sultan, Khromykh, Alexander A., Asgari, Sassan
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 31.07.2017; Nature Publishing Group; Nature Portfolio
• Subjects: 631/326/596/1413; 631/326/596/2557; Aedes - cytology; Aedes - virology; Aedes aegypti; Animals; Aquatic insects; Cell culture; Cell Line; Cell lines; Cercopithecus aethiops; Dengue - virology; Dengue fever; Dengue Virus - isolation & purification; Dengue Virus - pathogenicity; Disease transmission; Double-stranded RNA; Endocytosis; Endoribonucleases - metabolism; Fever; Flavivirus - classification; Flavivirus - isolation & purification; Flavivirus - pathogenicity; Humanities and Social Sciences; Infections; Mosquitoes; multidisciplinary; pH effects; Phylogeny; Replication; Ribonuclease; RNA Interference; RNA viruses; RNA-mediated interference; Science; Science (multidisciplinary); Vector-borne diseases; Vero Cells; Vertebrates; Viral Nonstructural Proteins - genetics; Virus Replication; Viruses; West Nile virus
• DOI: 10.1038/s41598-017-07279-5
• ISSN: 2045-2322

The genus Flavivirus contains more than 70 single-stranded, positive-sense arthropod-borne RNA viruses. Some flaviviruses are particularly medically important to humans and other vertebrates including dengue virus (DENV), West Nile virus, and yellow fever virus. These viruses are transmitted to vertebrates by mosquitoes and other arthropod species. Mosquitoes are also infected by insect-specific flaviviruses (ISFs) that do not appear to be infective to vertebrates. Cell fusing agent virus (CFAV) was the first described ISF, which was discovered in an Aedes aegypti cell culture. We found that while CFAV infection could be significantly reduced by application of RNAi against the NS5 gene, removal of the treatment led to quick restoration of CFAV replication. Interestingly, we found that CFAV infection significantly enhanced replication of DENV, and vice versa, DENV infection significantly enhanced replication of CFAV in mosquito cells. We have shown that CFAV infection leads to increase in the expression of ribonuclease kappa (RNASEK), which is known to promote infection of viruses that rely on endocytosis and pH-dependent entry. Knockdown of RNASEK by dsRNA resulted in reduced DENV replication. Thus, increased expression of RNASEK induced by CFAV is likely to contribute to enhanced DENV replication in CFAV-infected cells.