SFTS phlebovirus promotes LC3-II accumulation and nonstructural protein of SFTS phlebovirus co-localizes with autophagy proteins

• Published in: Scientific reports 2018-03, Vol.8 (1), p.5287-11, Article 5287
• Main Authors: Sun, Yue, Liu, Miao-miao, Lei, Xiao-ying, Yu, Xue-jie
• Format: Article
• Language: English
• Subjects: 13/109; 13/89; 14; 14/19; 14/32; 59; 631/326; 631/326/596; 631/326/596/2553; 64; 82/1; Antiviral agents; Autophagy; Biodegradation; Hemorrhage; Hemorrhagic fever; Homeostasis; Humanities and Social Sciences; Infections; Localization; multidisciplinary; Phagocytosis; Protein structure; Proteins; Replication; Science; Science (multidisciplinary); Thrombocytopenia; Vero cells
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-018-23610-0

Autophagy is essential for eukaryotic cell homeostasis and can perform both anti-viral and pro-viral roles depending on the kinds of viruses, cell types and cell environment. Severe fever with thrombocytopenia syndrome phlebovirus (SFTSV) is a newly discovered tick-borne virus in the Phenuiviridae family that causes a severe hemorrhagic fever disease in East Asia. In this study we determined interactions between SFTSV and autophagy. Our results showed that LC3-II (microtubule associated protein 1 light chain 3-II) protein accumulated from 4 h to 24 h after SFTSV infection compared to mock-infected Vero cells, and the use of E64d and pepstatin A did not affect the expression of LC3-II protein, which indicated that the increased LC3-II may be the result of inhibition of autophagic degradation caused by SFTSV infection. However, knockdown of LC3B promotes SFTSV replication, which indicated a negative role of LC3B protein in SFTSV replication. We also detected co-localization of SFTSV non-structure (NSs) protein with LC3B, p62 and Lamp2b respectively in SFTSV infected Vero cells, which indicated the possibility of selective autophagy or chaperone-mediated autophagy involving in SFTSV infection. Our results indicated that SFTSV infection promotes LC3 accumulation and several proteins of the autophagy pathway co-localize with NSs protein during SFTSV infection.