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Development of Immunologic Assays to Measure Response in Horses Vaccinated with Xenogeneic Plasmid DNA Encoding Human Tyrosinase
Journal of Equine Veterinary Science (2012)
  • Luis M Lembcke, University of Tennessee - Knoxville
  • Stephen A Kania, University of Tennessee - Knoxville
  • James T Blackford, University of Tennessee - Knoxville
  • Dianne J Trent, University of Tennessee - Knoxville
  • Agricola Odoi, University of Tennessee, Knoxville
  • Deborah A Grosenbaugh
  • Darrilyn G Fraser
  • Timothy Leard
  • Jeffrey C Phillips, Lincoln Memorial University
Xenogeneic plasmid DNA constructs have been developed and optimized for immunotherapies targeting cancer in both humans and dogs. Specifically, plasmid vectors containing the tumor antigen tyrosinase have demonstrated immunoreactivity and clinical benefit in the treatment of melanocytic tumors in these species. Overexpression of tyrosinase has also been noted in equine melanocytic tumors, supporting its role as a valid tumor antigen in the horse. Vaccination with plasmid constructs containing tyrosinase may thus have translational immunoreactivity in the treatment of equine melanomas. Here, we describe a methodology that is highly sensitive and specific for the detection of both humoral and cell-mediated immunoreactivity against tyrosinase in equine patients. These antigen-specific immunoassays are used to measure the humoral and cell-mediated responses in a cohort of horses vaccinated with xenogeneic plasmid DNA encoding human tyrosinase. Serum humoral responses were measured using standard enzyme-linked immunosorbent assay technique against the full-length recombinant human tyrosinase protein. Peripheral blood mononuclear cells were collected from vaccinated horses and stimulated with tyrosinase-specific peptides. Cellmediated responses were then measured using a novel quantitative real-timepolymerase chain reaction technique to determine resultant interferon-g expression. All horses developed significantly positive humoral and cell-mediated immune responses compared with their individual prevaccination values. No adverse reactions or signs of autoimmunity were detected. Vaccination with xenogeneic plasmid DNA expressing tyrosinase appears to elicit tumor antigen-specific reactivity and should be evaluated in a larger cohort of horses with melanocytic tumors.
  • Immunologic Assays,
  • Melanoma,
  • Vaccine,
  • Immunotherapy,
  • Horse,
  • Equine,
  • Tyrosiase,
  • Immune Response
Publication Date
Spring April 12, 2012
Citation Information
Luis M Lembcke, Stephen A Kania, James T Blackford, Dianne J Trent, et al.. "Development of Immunologic Assays to Measure Response in Horses Vaccinated with Xenogeneic Plasmid DNA Encoding Human Tyrosinase" Journal of Equine Veterinary Science Vol. 32 (2012)
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