The preparation and therapeutic roles of scFv-Fc antibody against Staphylococcus aureus infection to control bovine mastitis

Appl Microbiol Biotechnol. 2019 Feb;103(4):1703-1712. doi: 10.1007/s00253-018-9548-6. Epub 2019 Jan 3.

Abstract

Staphylococcus aureus-induced bovine mastitis causes significant losses to the dairy industry and available vaccines do not confer adequate protection. As a more attractive alternative, we propose the use of antibody (Ab) therapy. In our previous study, we constructed a bovine single-chain variable fragment (scFv) Ab phage display and successfully obtained scFvs that bound to S. aureus antigens with high affinity. Here, we describe a novel Ab against S. aureus (scFv-Fc Ab). To construct the scFv-Fc Ab, the scFv Ab was genetically fused to the Fc fragment of a bovine IgG1 Ab. Western blot analysis showed that the bovine scFvs-Fc Abs were successfully expressed with horseradish peroxidase-conjugated goat-anti-bovine IgG (Fc) Ab in Escherichia coli cells. The purified bovine scFvs-Fc Abs had good binding activity to S. aureus and effectively inhibited the bacterial growth in culture medium and bovine scFvs-Fc Abs enhanced phagocytosis of S. aureus by neutrophils isolated from peripheral blood in a dose-dependent manner. In the experiment of bovine scFvs-Fc Abs for the treatment of S. aureus-induced bovine mastitis, the total effective percentage reached 82% (9/11). These novel bovine scFvs-Fc Abs may be useful as therapeutic candidates for the prevention and treatment of S. aureus-induced bovine mastitis.

Keywords: Bovine mastitis; Fc; Phagocytosis; Single-chain variable region fragment (scFv); Staphylococcus aureus.

MeSH terms

  • Animals
  • Anti-Bacterial Agents / administration & dosage*
  • Cattle
  • Immunoglobulin Fc Fragments / administration & dosage*
  • Immunoglobulin Fc Fragments / genetics
  • Immunoglobulin Fc Fragments / isolation & purification
  • Mastitis, Bovine / drug therapy*
  • Recombinant Fusion Proteins / administration & dosage
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / isolation & purification
  • Single-Chain Antibodies / administration & dosage*
  • Single-Chain Antibodies / genetics
  • Single-Chain Antibodies / isolation & purification
  • Staphylococcal Infections / drug therapy
  • Staphylococcal Infections / veterinary*
  • Treatment Outcome

Substances

  • Anti-Bacterial Agents
  • Immunoglobulin Fc Fragments
  • Recombinant Fusion Proteins
  • Single-Chain Antibodies