| Title |
Immune parameters and vaccine efficacy in Mycobacterium avium subspecies paratuberculosis experimentally infected sheep |
| Author(s) |
Begg D*,
Griffin JFT.
|
| Institution(s) |
Disease Research laboratory, Dept. of Microbiology and Immunology, University of Otago, New Zealand; * Present address Farm Animal Health Group, Faculty of Veterinary Science, University of Sydney, Australia
|
| Source |
Eighth International Colloquium on Paratuberculosis
|
| Section |
2:
Immunology, pathology and pathogenesis
|
| Presentation |
Poster
|
| Abstract |
Johne's disease in ruminants is caused by the pathogenic bacterium Mycobacterium avium subsp. paratuberculosis (Map). Currently available Map commercial vaccines protect against clinical disease but not infection. Using an experimental model of ovine Johne's disease this study examined the proprietary Johne's vaccine Neoparasec™ and an Aqueous formulation of Map 316F (AquaVax). Detailed immunological examinations including lymphocyte transformation assays, FACS analysis, IFN-γ and antibody detection from blood and gut associated lymphoid tissues was carried out on animals after vaccination and challenge with virulent Map to identify markers of protective immunity. Neoparasec™ vaccination provided significant protection against disease while AquaVax did not. Diseased animals had different immune responses from different gut lymphatic tissues which correlated with the histopathology observed. Immune animals had stronger cell-mediated responses and altered proportions of CD4+, CD8+, CD25+ and B cells in blood, spleen and the gut lymphatics, than diseased animals.
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