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Misra N, Wines TF, Knopp CL, Hermann R, Bond L, Mitchell B, McGuire MA, Tinker JK. Immunogenicity of a Staphylococcus aureus-cholera toxin A 2/B vaccine for bovine mastitis. Vaccine 2018; 36:3513-3521. [PMID: 29739718 DOI: 10.1016/j.vaccine.2018.04.067] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 04/09/2018] [Accepted: 04/22/2018] [Indexed: 01/10/2023]
Abstract
Staphylococcus aureus causes a chronic, contagious disease of the udder, or mastitis, in dairy cows. This infection is often refractory to antibiotic treatment, and has a significant economic impact on milk production worldwide. An effective vaccine to prevent S. aureus mastitis would improve animal health, reduce antibiotic dependence and inform human vaccine approaches. The iron-regulated surface determinant A (IsdA) and clumping factor A (ClfA) are conserved S. aureus extracellular-matrix adhesins and target vaccine antigens. Here we report the results of two bovine immunogenicity trials using purified IsdA and ClfA-cholera toxin A2/B chimeras (IsdA-CTA2/B and ClfA-CTA2/B). Cows were intranasally inoculated with IsdA-CTA2/B + ClfA-CTA2/B at dry off and followed for 70 days. Trial 1 utilized three groups with one or two booster doses at a total concentration of 600 or 900 μg. Trial 2 utilized two groups with one booster at a total concentration of 1200 μg. Humoral immune responses in serum and milk were examined by ELISA. Responses in serum were significant between groups and provide evidence of antigen-specific IgG induction after vaccination in both trials. Cellular proliferation was detected by flow cytometry using antigen-stimulated PBMCs from day 60 of Trial 2 and revealed an increase in CD4+ T cells from vaccinated cows. IsdA and ClfA stimulation induced IL-4 expression, but not IFN-γ or IL-17, in PBMCs from day 60 as determined by cytokine expression analysis. Opsonophagocytosis of S. aureus confirmed the functional in vitro activity of anti-IsdA antibodies from Trial 2 serum and milk. The vaccine was well tolerated and safe, and results support the potential of mucosally-delivered CTA2/B chimeras to protect cows from mastitis caused by S. aureus.
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Affiliation(s)
- N Misra
- Biomolecular Ph.D. Program, Boise State University, Boise, ID, USA
| | - T F Wines
- Department of Biological Sciences, Boise State University, Boise, ID, USA
| | - C L Knopp
- Department of Biological Sciences, Boise State University, Boise, ID, USA
| | - R Hermann
- Department of Biological Sciences, Boise State University, Boise, ID, USA; Biomolecular Ph.D. Program, Boise State University, Boise, ID, USA
| | - L Bond
- Biomolecular Research Center, Boise State University, Boise, ID, USA
| | - B Mitchell
- DairyTeam Nutrition and Veterinary Consulting, Boise, ID, USA
| | - M A McGuire
- Department of Animal and Veterinary Science, University of Idaho, Moscow, ID, USA
| | - J K Tinker
- Department of Biological Sciences, Boise State University, Boise, ID, USA; Biomolecular Ph.D. Program, Boise State University, Boise, ID, USA.
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