Fine mapping epitope on glycoprotein-Gn from Crimean-Congo hemorrhagic fever virus

Glycoprotein (GP) is a major antigen of Crimean-Congo hemorrhagic fever virus (CCHFV), and binds to its receptor on the host cell and induces protective immunity in the host. The aim of this study is to identify all linear B cell epitopes (BCEs) on the N-terminal glycoprotein (Gn) of CCHFV using a modified overlapping peptide biosynthesis method. The eight fine BCEs (Gn-E1a, (543)RTQLV(547); E1b, (EIH555)-E-553; E1c, (IHEDSY559)-I-554; E1d, (557)DSYG(560); E2, (615)CKQGFC(620); E3a, (657)GDILVD(662); E3b, (662)DCSGGQQH(669), and E4, (678)LGCPNVPL(685)) were identified using the rabbit antisera, which all were recognized by serum from IgG-positive sheep CCHFV-infected naturally in Western blotting. The multiple sequence alignment (MSA) revealed high conservation of the identified BCEs among ten CCHFV strains from different areas. These mapped epitopes of the CCHFV Gn would provide a basis for further the elucidation of CCHFV pathogenesis, and the development of CCHFV multi-epitope vaccines and detection reagents.