Fine mapping epitope on Glycoprotein-Gn from Severe Fever with Thrombocytopenia Syndrome Virus

PLoS One. 2021 Mar 2;16(3):e0248005. doi: 10.1371/journal.pone.0248005. eCollection 2021.

Abstract

Severe Fever with Thrombocytopenia Syndrome Virus (SFTSV) was recently identified as a tick-borne pathogen that threat to human health. Since 2010, many countries including China, South Korea, and Japan have reported Human SFTS caused by SFTSV infection. The glycoprotein encoded by the SFTSV M gene is the major antigenic component on the viral surface, and responsible for the viral entry, which makes it an important viral antigen and a clinical diagnostic target. The present study aimed to map linear B cell epitopes (BCEs) on the N-terminal glycoprotein (Gn) from SFTSV strain WCH/97/HN/China/2011 using the modified biosynthetic peptide method. Five fine epitopes (E1, 196FSQSEFPD203; E2, 232GHSHKII238; E3, 256VCYKEGTGPC265; E4, 285FCKVAG290, and E5, 316SYGGM320) were identified using the rabbit antisera. Western blot analysis showed that all the five epitopes interacted with the positive serum of sheep that had been naturally infected with SFTSV. Three-dimensional structural modeling analysis showed that all identified BCEs were located on the surface of the SFTSV-Gn and contained flexible loops. The sequence alignment revealed high conservation of the identified BCEs among 13 SFTSV strains from different lineage. These mapped epitopes will escalate the understanding of the epitope distribution and pathogenic mechanism of SFTSV, and could provide a basis for the development of a SFTSV multi-epitope detection antigen.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chlorocebus aethiops
  • Epitope Mapping
  • Epitopes / immunology*
  • Glycoproteins / immunology*
  • Phlebovirus*
  • Severe Fever with Thrombocytopenia Syndrome / immunology*
  • Vero Cells

Substances

  • Epitopes
  • Glycoproteins

Grants and funding

This work was supported partly by grants from the National Natural Science Foundation of China (No. 81760365, 81690369 to S. R. S.), the Science Research Key Project of Xinjiang Education Department (No. XJEDU2019I002 to S. R. S.), and the Science and Technology Basic Work Program (No. 2013FY113500 to Y. J. Z) from the Ministry of Science and Technology of China, and funded by the Open Research Fund Program of the State Key Laboratory of Virology of China (No. 2015IOV003 to F. D.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.