2007 Annual Report
Established a therapeutic application for a Toll-like receptor agonist in the treatment of Staphylococcus aureus-induced mastitis. Staphylococcus aureus (S. aureus) are one of the most prevalent bacteria to cause mastitis and intramammary infections caused by these bacteria are difficult to treat and can persist throughout the lifetime of the animal. We have demonstrated that bacterial lipopolysaccharide, which activates the host immune receptor Toll-like receptor-4, can reduce intramammary S. aureus bacterial concentrations by 10-fold. This finding provides evidence for the therapuetic application of Toll-like receptor-4 agonists to the treatment of mastitis and offers a new treatment option for the management of this disease. This accomplishment addresses “Component 2: Genetic and Biological Determinants of Disease Susceptibility; Problem Statement 2A: Mastitis” in the 2007-2012 National Program 103 Action Plan.
Developed and validated assays for measuring bovine neutrophil reactive oxygen species. Neutrophil-derived reactive oxygen species (ROS), which are released in response to infection, can cause injury to host tissues. Because there is a need for anti-inflammatory compounds that can minimize injury to the host without impairing the host’s ability to clear harmful bacterial pathogens, development of assays that can specifically measure bovine ROS are useful for screening and identifying novel compounds with such activity. We have now developed and validated assays that can discriminate between intracellular ROS that are critical to the control of infection and extracellular ROS that can damage host tissues. These assays provide a means for measuring key molecules critically involved in the innate immune response of the bovine mammary gland during mastitis. Further, these methods are currently being used to identify novel anti-inflammatory compounds. This accomplishment addresses “Component 2: Genetic and Biological Determinants of Disease Susceptibility; Problem Statement 2A: Mastitis” in the 2007-2012 National Program 103 Action Plan.
Completed an experiment demonstrating that in vivo treatment with xanthosine expands the mammary stem cell population in dairy heifers. Findings were presented at the national meeting of the ADSA/ASAS and provide a strong base for future research in this area. Increasing expansion of mammary stem cells has the potential to enhance proliferation and replacement of mammary epithelial cells. This strategy may provide a tool for increasing the replacement of cells damaged by mastitis and for increasing lactation efficiency. This accomplishment addresses “Component 2: Genetic and Biological Determinants of Disease Susceptibility; Problem Statement 2A: Mastitis” in the 2007-2012 National Program 103 Action Plan.
Burvenich, C., Bannerman, D.D., Lippolis, J.D., Peelman, L., Nonnecke, B.J., Kehrli, Jr., M.E., Paape, M.J. 2007. Cumulative physiological events influence the inflammatory response of the bovine udder to Escherichia coli infections during the transition period. Journal of Dairy Science. 90(E.Suppl.):E39-E54.
Kauf, A.C., Rosenbusch, R.F., Paape, M.J., Bannerman, D.D. 2007. Innate Immune Response to Intramammary Mycoplasma bovis Infection. Journal of Dairy Science. 90(7):3336-3348.
Kauf, A.C., Vinyard, B.T., Bannerman, D.D. 2007. Effect of intramammary infusion of bacterial lipopolysaccharide on experimentally induced staphylococcus aureus intramammary infection. Res. Vet. Sci. 82(1):39-46.
Kim, F., Pham, M., Luttrell, I., Bannerman, D.D., Tupper, J., Thaler, J., Hawn, T.R., Raines, E.W., Schwartz, M.W. 2007. Toll Like Receptor-4 Mediates Vascular Inflammation and Insulin Resistance in Diet-Induced Obesity. Circulation Research. 100(11):1589-1596.
Paape, M.J., Wiggans, G.R., Bannerman, D.D., Thomas, D.L., Sanders, A.H., Contreras, A., Moroni, P., Miller, R.H. 2007. Monitoring goat and sheep milk somatic cell counts. Small Ruminant Research. 68(1-2):114-125.
Rinaldi, M., Moroin, P., Leino, L., Paape, M.J., Bannerman, D.D. 2006. Effect of cis-urocanic acid on bovine neutrophil generation of reactive oxygen species. Journal of Dairy Science. 89(11):4188-4201.
Rinaldi, M., Moroni, P., Paape, M.J., Bannerman, D.D. 2007. Evaluation of assays for the measurement of bovine neutrophil reactive oxygen species. Vet.Immunol. Immunopathol. 115(1-2):107-125.
Sohn, E.J., Paape, M.J., Bannerman, D.D., Connor, E.E., Fetterer, R.H., Peters, R.R. 2007. Shedding of sCD14 by bovine neutrophils following activation with bacterial lipopolysaccharide results in down-regulation of IL-8. Vet. Res. 38(1):95-108.