title: Identification of two linear B-cell epitopes from West Nile virus NS1 by screening a phage-displayed random peptide library.
abstract: BACKGROUND
  The West Nile virus (WNV) nonstructural protein 1 (NS1) is an important antigenic protein that elicits protective antibody responses in animals and can be used for the serological diagnosis of WNV infection. Although previous work has demonstrated the vital role of WNV NS1-specific antibody responses, the specific epitopes in the NS1 have not been identified.
  
  
  RESULTS
  The present study describes the identification of two linear B-cell epitopes in WNV NS1 through screening a phage-displayed random 12-mer peptide library with two monoclonal antibodies (mAbs) 3C7 and 4D1 that directed against the NS1. The mAbs 3C7 and 4D1 recognized phages displaying peptides with the consensus motifs LTATTEK and VVDGPETKEC, respectively. Exact sequences of both motifs were found in the NS1 ((895)LTATTEK(901) and (925)VVDGPETKEC(934)). Further identification of the displayed B cell epitopes were conducted using a set of truncated peptides expressed as MBP fusion proteins. The data indicated that (896)TATTEK(901) and (925)VVDGPETKEC(934) are minimal determinants of the linear B cell epitopes recognized by the mAbs 3C7 and 4D1, respectively. Antibodies present in the serum of WNV-positive horses recognized the minimal linear epitopes in Western blot analysis, indicating that the two peptides are antigenic in horses during infection. Furthermore, we found that the epitope recognized by 3C7 is conserved only among WNV strains, whereas the epitope recognized by 4D1 is a common motif shared among WNV and other members of Japanese encephalitis virus (JEV) serocomplex.
  
  
  CONCLUSIONS
  We identified TATTEK and VVDGPETKEC as NS1-specific linear B-cell epitopes recognized by the mAbs 3C7 and 4D1, respectively. The knowledge and reagents generated in this study may have potential applications in differential diagnosis and the development of epitope-based marker vaccines against WNV and other viruses of JEV serocomplex.
authors: The Key Laboratory of Veterinary Public Health, Ministry of Agriculture, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 427 Maduan Street, Nangang District, Harbin 150001, PR China.
authors: En-Cheng
authors: EC
authors: Sun
authors: Jian-Nan
authors: JN
authors: Ma
authors: Ni-Hong
authors: NH
authors: Liu
authors: Tao
authors: T
authors: Yang
authors: Jing
authors: J
authors: Zhao
authors: Hong-Wei
authors: HW
authors: Geng
authors: Ling-Feng
authors: LF
authors: Wang
authors: Yong-Li
authors: YL
authors: Qin
authors: Zhi-Gao
authors: ZG
authors: Bu
authors: Yin-Hui
authors: YH
authors: Yang
authors: Ross A
authors: RA
authors: Lunt
authors: Lin-Fa
authors: LF
authors: Wang
authors: Dong-Lai
authors: DL
authors: Wu
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000302:isolation & purification; D000914:Antibodies, Viral / Q000097:blood; D015153:Blotting, Western; D018985:Epitopes, B-Lymphocyte / Q000235:genetics / Q000276:immunology*; D006734:Horse Diseases / Q000276:immunology; D006736:Horses; D008403:Mass Screening; D051379:Mice; D008807:Mice, Inbred BALB C; D019151:Peptide Library; D017361:Viral Nonstructural Proteins / Q000235:genetics / Q000276:immunology*; D014901:West Nile Fever / Q000276:immunology / Q000662:veterinary; D014902:West Nile virus / Q000235:genetics / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D018985:Epitopes, B-Lymphocyte; D019151:Peptide Library; D017361:Viral Nonstructural Proteins; C531936:nonstructural protein 1, West Nile virus