Profiling immune responses in dairy calves experimentally infected with Mycobacterium avium subsp. paratuberculosis (Map)
Date
2013-09-25
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Abstract
Johne’s disease (JD) is a debilitating chronic enteritis in ruminants caused by Mycobacterium avium subsp. paratuberculosis (Map). JD causes substantial losses to the dairy industry due to reduced milk production, fertility rates and increased culling. The control of JD is complicated by the difficult diagnosis of the disease in its early stages and low sensitivity of the current diagnostics. As Map eventually survives in the host tissue despite of aggressive immune response, our aim was to profile early Map - induced immune responses in dairy calves infected with a high or low dose of Map for a 6-month period. The circulating T-lymphocytes were profiled by their phenotypic markers and signature cytokines. Regulatory T cell markers (Foxp3, IL-10 and TGF-β) were all upregulated during the first 2 months after infection, and a shift to Th1 response with robust IFN-γ production was observed, which lasted until the end of the study. Th2 response (IL-4) was very weak during the course of this study. Upregulation of CCR9 after 6 months of infection was also observed. In conclusion, regulatory T cell response that occurs early after Map exposure is vigorous and infective dose dependent but short lived; it is then replaced by a strong Th1 response and interferon-gamma production, characteristic of subclinical JD.
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Immunology
Citation
Khalil, Y. (2013). Profiling immune responses in dairy calves experimentally infected with Mycobacterium avium subsp. paratuberculosis (Map) (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/27450