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

Abulimiti Moming,Shen Shi,Jie Qiao,Zhihong Hu,Surong Sun,Xihong Yue,Bo Wang,Yujiang Zhang,Shu Shen,Fei Deng,Juntao Ding,Paulo Lee Ho

doi:10.1371/journal.pone.0248005

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.

Highlights

Severe Fever with Thrombocytopenia Syndrome Virus (SFTSV) is a human pathogen that causes Severe Fever with Thrombocytopenia Syndrome (SFTS), an emerging disease with high mortality rates up to 30% [1,2,3]
Since 2010, SFTSV is broadly disseminated in countries like China, South Korea, and Japan [4,5,6]
These Western blot and immunofluorescence assay (IFA) results suggest that r-SGn has efficient antigenicity and polyclonal antibody (pAb) α-SGn has an effective ability to recognize antigens

Summary

Introduction

Severe Fever with Thrombocytopenia Syndrome Virus (SFTSV) is a human pathogen that causes Severe Fever with Thrombocytopenia Syndrome (SFTS), an emerging disease with high mortality rates up to 30% [1,2,3]. Since 2010, SFTSV is broadly disseminated in countries like China, South Korea, and Japan [4,5,6]. The clinical symptoms of SFTSV infections include fever, thrombocytopenia, gastrointestinal disorder, and leukocytopenia [7]. SFTSV is a tickborne virus [8] and has infected many domestic animals, including goats, cattle, dogs, cats and chickens [9,10,11,12]. Humans could generally be infected through tick bites, direct contact with.

Methods

Results

Conclusion