title: Fine level epitope mapping and conservation analysis of two novel linear B-cell epitopes of the avian infectious bronchitis coronavirus nucleocapsid protein.
abstract: The nucleocapsid (N) protein of the infectious bronchitis virus (IBV) may play an essential role in the replication and translation of viral RNA. The N protein can also induce high titers of cross-reactive antibodies and cell-mediated immunity, which protects chickens from acute infection. In this study, we generated two monoclonal antibodies (mAbs), designated as 6D10 and 4F10, which were directed against the N protein of IBV using the whole viral particles as immunogens. Both of the mAbs do not cross react with Newcastle disease virus (NDV), infectious laryngotracheitis virus (ILTV) and subtype H9 avian influenza virus (AIV). After screening a phage display peptide library and peptide scanning, we identified two linear B-cell epitopes that were recognized by the mAbs 6D10 and 4F10, which corresponded to the amino acid sequences (242)FGPRTK(247) and (195)DLIARAAKI(203), respectively, in the IBV N protein. Alignments of amino acid sequences from a large number of IBV isolates indicated that the two epitopes, especially (242)FGPRTK(247), were well conserved among IBV strains. This conclusion was further confirmed by the relationships of 18 heterologous sequences to the 2 mAbs. The novel mAbs and the epitopes identified will be useful for developing diagnostic assays for IBV infections.
authors.affiliation: Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150001, People's Republic of China.
authors.forename: Zongxi
authors.initials: Z
authors.lastname: Han
authors.forename: Fei
authors.initials: F
authors.lastname: Zhao
authors.forename: Yuhao
authors.initials: Y
authors.lastname: Shao
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Liu
authors.forename: Xiangang
authors.initials: X
authors.lastname: Kong
authors.forename: Yang
authors.initials: Y
authors.lastname: Song
authors.forename: Shengwang
authors.initials: S
authors.lastname: Liu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000914:Antibodies, Viral / Q000276:immunology; D002642:Chick Embryo; D003429:Cross Reactions; D018604:Epitope Mapping; D018985:Epitopes, B-Lymphocyte / Q000737:chemistry / Q000276:immunology*; D001351:Infectious bronchitis virus / Q000145:classification / Q000235:genetics / Q000276:immunology*; D008969:Molecular Sequence Data; D019590:Nucleocapsid Proteins / Q000235:genetics / Q000276:immunology*; D019151:Peptide Library; D010455:Peptides / Q000737:chemistry / Q000276:immunology; D010802:Phylogeny; D016415:Sequence Alignment
chemical_list: D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D018985:Epitopes, B-Lymphocyte; D019590:Nucleocapsid Proteins; D019151:Peptide Library; D010455:Peptides