title: Identification of three novel B-cell epitopes of VMH protein from Vibrio mimicus by screening a phage display peptide library.
abstract: Vibrio mimicus is the causative agent of ascites disease in fish. The heat-labile hemolytic toxin designated VMH is an immunoprotective antigen of V. mimicus. However, its epitopes have not been well characterized. Here, a commercially available phage displayed 12-mer peptide library was used to screen epitopes of VMH protein using polyclonal rabbit anti-rVMH protein antibodies, and then five positive phage clones were identified by sandwich and competitive ELISA. Sequences analysis showed that the motif of DPTLL displayed on phage clone 15 and the consensus motif of SLDDDST displayed on the clone 4/11 corresponded to the residues 134-138 and 238-244 of VMH protein, respectively, and the synthetic motif peptides could also be recognized by anti-rVMH-HD antibody in peptide-ELISA. Thus, both motifs DPTLL and SLDDDST were identified as minimal linear B-cell epitopes of VMH protein. Although no similarity was found between VMH protein and the consensus motif of ADGLVPR displayed on the clone 2/6, the synthetic peptide ADGLVPR could absorb anti-rVMH-HD antibody and inhibit the antibody binding to rVMH protein in enhanced chemoluminescence Western blotting, whereas irrelevant control peptide did not affect the antibody binding with rVMH. These results revealed that the peptide ADGLVPR was a mimotope of VMH protein. Taken together, three novel B-cell epitopes of VMH protein were identified, which provide a foundation for developing epitope-based vaccine against V. mimicus infection in fish.
authors.affiliation: College of Animal Science and Technology, Anhui Agricultural University, Hefei, 230036, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Xiao
authors.affiliation: College of Animal Science and Technology, Anhui Agricultural University, Hefei, 230036, China.
authors.forename: Ji
authors.initials: J
authors.lastname: Cao
authors.affiliation: College of Animal Science and Technology, Anhui Agricultural University, Hefei, 230036, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Zhou
authors.affiliation: College of Animal Science and Technology, Anhui Agricultural University, Hefei, 230036, China.
authors.forename: Shu-Quan
authors.initials: SQ
authors.lastname: Ding
authors.affiliation: College of Animal Science and Technology, Anhui Agricultural University, Hefei, 230036, China.
authors.forename: Ling-Yan
authors.initials: LY
authors.lastname: Kong
authors.affiliation: College of Animal Science and Technology, Anhui Agricultural University, Hefei, 230036, China. Electronic address: lijinnian2000@163.com.
authors.forename: Jin-Nian
authors.initials: JN
authors.lastname: Li
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000907:Antibodies, Bacterial; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology*; D001428:Bacterial Vaccines / Q000235:genetics / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D018985:Epitopes, B-Lymphocyte / Q000235:genetics / Q000276:immunology*; D005393:Fish Diseases / Q000276:immunology / Q000382:microbiology; D005399:Fishes; D006460:Hemolysin Proteins / Q000235:genetics / Q000276:immunology*; D019151:Peptide Library; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology; D014735:Vibrio Infections / Q000276:immunology / Q000382:microbiology / Q000662:veterinary; D044164:Vibrio mimicus / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity
chemical_list: D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D001428:Bacterial Vaccines; D018985:Epitopes, B-Lymphocyte; D006460:Hemolysin Proteins; D019151:Peptide Library; D011993:Recombinant Fusion Proteins; C105588:VmhA protein, Vibrio mimicus
keywords: ECL-Western blotting; Epitopes; Phage display; VMH protein; Vibrio mimicus