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

Sci Rep. 2018 Mar 27;8(1):5287. doi: 10.1038/s41598-018-23610-0.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autophagy
  • Chlorocebus aethiops
  • Host-Pathogen Interactions
  • Humans
  • Mice, Inbred BALB C
  • Microtubule-Associated Proteins / analysis
  • Microtubule-Associated Proteins / metabolism*
  • Phlebotomus Fever / metabolism*
  • Phlebotomus Fever / pathology
  • Phlebovirus / physiology*
  • Vero Cells
  • Viral Nonstructural Proteins / analysis
  • Viral Nonstructural Proteins / metabolism*
  • Virus Replication

Substances

  • Microtubule-Associated Proteins
  • Viral Nonstructural Proteins

Supplementary concepts

  • SFTS phlebovirus