title: Identification of a conserved B-cell epitope on reticuloendotheliosis virus envelope protein by screening a phage-displayed random peptide library.
abstract: BACKGROUND
  The gp90 protein of avian reticuloendotheliosis-associated virus (REV-A) is an important envelope glycoprotein, which is responsible for inducing protective antibody immune responses in animals. B-cell epitopes on the gp90 protein of REV have not been well studied and reported.
  
  
  RESULTS
  This study describes the identification of a linear B-cell epitope on the gp90 protein by screening a phage-displayed 12-mer random peptide library with the neutralizing monoclonal antibody (mAb) A9E8 directed against the gp90. The mAb A9E8 recognized phages displaying peptides with the consensus motif SVQYHPL. Amino acid sequence of the motif exactly matched (213)SVQYHPL(219) of the gp90. Further identification of the displayed B cell epitope was conducted using a set of truncated peptides expressed as GST fusion proteins and the Western blot results indicated that (213)SVQYHPL(219) was the minimal determinant of the linear B cell epitope recognized by the mAb A9E8. Moreover, an eight amino acid peptide SVQYHPLA was proven to be the minimal unit of the epitope with the maximal binding activity to mAb A9E8. The REV-A-positive chicken serum reacted with the minimal linear epitopes in Western blot, revealing the importance of the eight amino acids of the epitope in antibody-epitope binding activity. Furthermore, we found that the epitope is a common motif shared among REV-A and other members of REV group.
  
  
  CONCLUSIONS
  We identified (213)SVQYHPL(219) as a gp90-specific linear B-cell epitope recognized by the neutralizing mAb A9E8. The results in this study may have potential applications in development of diagnostic techniques and epitope-based marker vaccines against REV-A and other viruses of the REV group.
authors.affiliation: Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, The Chinese Academy of Agricultural Sciences, Harbin, P. R. China.
authors.forename: Mei
authors.initials: M
authors.lastname: Xue
authors.forename: Xingming
authors.initials: X
authors.lastname: Shi
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
authors.forename: Hongyu
authors.initials: H
authors.lastname: Cui
authors.forename: Shunlei
authors.initials: S
authors.lastname: Hu
authors.forename: Hongbo
authors.initials: H
authors.lastname: Gao
authors.forename: Xianlan
authors.initials: X
authors.lastname: Cui
authors.forename: Yun-Feng
authors.initials: YF
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral / Q000097:blood / Q000235:genetics / Q000276:immunology; D001435:Bacteriophages / Q000235:genetics / Q000276:immunology; D018604:Epitope Mapping; D018985:Epitopes, B-Lymphocyte / Q000235:genetics / Q000276:immunology; D006801:Humans; D019151:Peptide Library; D010455:Peptides / Q000235:genetics / Q000276:immunology; D001356:Reticuloendotheliosis virus / Q000235:genetics / Q000276:immunology; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification
chemical_list: D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D018985:Epitopes, B-Lymphocyte; D019151:Peptide Library; D010455:Peptides; D014759:Viral Envelope Proteins