The preparation and therapeutic roles of scFv-Fc antibody against Staphylococcus aureus infection to control bovine mastitis
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.
KeywordsBovine mastitis Staphylococcus aureus Single-chain variable region fragment (scFv) Fc Phagocytosis
This study was supported by the National Key Research and Development Program of China (Grant Number: 2018YFD0501600).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
This study was conducted in accordance with all applicable international, national, and institutional guidelines for the care and use of animals.
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