Identification and characterization of a virus-specific continuous B-cell epitope on the PrM/M protein of Japanese Encephalitis Virus: potential application in the detection of antibodies to distinguish Japanese Encephalitis Virus infection from West Nile Virus and Dengue Virus infections.
BACKGROUND
Differential diagnose of Japanese encephalitis virus (JEV) infection from other flavivirus especially West Nile virus (WNV) and Dengue virus (DV) infection was greatly hindered for the serological cross-reactive. Virus specific epitopes could benefit for developing JEV specific antibodies detection methods. To identify the JEV specific epitopes, we fully mapped and characterized the continuous B-cell epitope of the PrM/M protein of JEV.


RESULTS
To map the epitopes on the PrM/M protein, we designed a set of 20 partially overlapping fragments spanning the whole PrM, fused them with GST, and expressed them in an expression vector. Linear epitope M14 (105VNKKEAWLDSTKATRY120) was detected by enzyme-linked immunosorbent assay (ELISA). By removing amino acid residues individually from the carboxy and amino terminal of peptide M14, we confirmed that the minimal unit of the linear epitope of PrM/M was M14-13 (108KEAWLDSTKAT118). This epitope was highly conserved across different JEV strains. Moreover, this epitope did not cross-react with WNV-positive and DENV-positive sera.


CONCLUSIONS
Epitope M14-13 was a JEV specific lineal B-cell epitpe. The results may provide a useful basis for the development of epitope-based virus specific diagnostic clinical techniques.
Hua
Rong-Hong
RH
State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, PR China.
Chen
Na-Sha
NS
Qin
Cheng-Feng
CF
Deng
Yong-Qiang
YQ
Ge
Jin-Ying
JY
Wang
Xi-Jun
XJ
Qiao
Zu-Jian
ZJ
Chen
Wei-Ye
WY
Wen
Zhi-Yuan
ZY
Liu
Wen-Xin
WX
Hu
Sen
S
Bu
Zhi-Gao
ZG
D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology; D017124:Conserved Sequence; D006224:Cricetinae; D003715:Dengue / Q000175:diagnosis*; D003716:Dengue Virus / Q000276:immunology; D003937:Diagnosis, Differential; D004664:Encephalitis Virus, Japanese / Q000276:immunology*; D004672:Encephalitis, Japanese / Q000175:diagnosis*; D018604:Epitope Mapping; D018985:Epitopes, B-Lymphocyte / Q000276:immunology*; D006801:Humans; D012680:Sensitivity and Specificity; D014759:Viral Envelope Proteins / Q000276:immunology*; D014901:West Nile Fever / Q000175:diagnosis*; D014902:West Nile virus / Q000276:immunology
D000914:Antibodies, Viral; D018985:Epitopes, B-Lymphocyte; D014759:Viral Envelope Proteins; C074932:prM protein, Flavivirus