Identification of a novel Haemophilus parasuis-specific B cell epitope using monoclonal antibody against the OppA protein

PLoS One. 2014 Jan 9;9(1):e84516. doi: 10.1371/journal.pone.0084516. eCollection 2014.

Abstract

Monoclonal antibody (MAb) 1B3 against Haemophilus parasuis (H. parasuis) was generated by fusing SP2/0 murine myeloma cells and spleen cells from BALB/c mice immunized with the whole-bacterial-cell suspension of H. parasuis HS80 (serotype 5). The MAb 1B3 showed strong reactivity with 15 serotype reference strains of H. parasuis using Dot blot and Western blot analysis. Immunoprecipitation and protein spectral analysis indicated that MAb 1B3 recognized by Oligopeptide permease A (OppA) belongs to the ATP binding cassette transporter family. In addition, a linear B-cell epitope recognized by MAb 1B3 was identified by the screening of a phage-displayed 12-mer random peptide library. Sequence analysis showed that MAb 1B3 was recognized by phages-displaying peptides with the consensus motif KTPSEXR (X means variable amino acids). Its amino acid sequence matched (469)KTPAEAR(475) of H. parasuis OppA protein. A series of progressively truncated peptides were synthesized to define the minimal region that was required for MAb 1B3 binding. The epitope was highly conserved in OppA protein sequences from the isolated H. parasuis strains, which was confirmed by alignment analysis. Furthermore, the minimal linear epitope was highly specific among 75 different bacterial strains as shown in sequence alignments. These results indicated MAb 1B3 might be potentially used to develop serological diagnostic tools for H. parasuis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antibodies, Monoclonal / immunology*
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / immunology*
  • Carrier Proteins / chemistry
  • Carrier Proteins / immunology*
  • Epitopes, B-Lymphocyte / chemistry
  • Epitopes, B-Lymphocyte / immunology*
  • Female
  • Haemophilus parasuis / immunology*
  • Haemophilus parasuis / isolation & purification
  • Lipoproteins / chemistry
  • Lipoproteins / immunology*
  • Mice
  • Mice, Inbred BALB C
  • Molecular Sequence Data
  • Sequence Homology, Nucleic Acid
  • Species Specificity

Substances

  • Antibodies, Monoclonal
  • Bacterial Proteins
  • Carrier Proteins
  • Epitopes, B-Lymphocyte
  • Lipoproteins
  • oligopeptide-binding protein, bacteria

Grants and funding

This study was supported by Special Fund for Agro-scientific Research in the Public Interest (201203056). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.