Variation in the Early Host-Pathogen Interaction of Bovine Macrophages with Divergent Mycobacterium bovis Strains in the United Kingdom
Date
2018-02-20
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Publisher
American Society for Microbiology
Abstract
Bovine tuberculosis has been an escalating animal health issue in the
United Kingdom since the 1980s, even though control policies have been in place
for over 60 years. The importance of the genetics of the etiological agent, Mycobacterium bovis, in the reemergence of the disease has been largely overlooked. We
compared the interaction between bovine monocyte-derived macrophages (bMDM)
and two M. bovis strains, AF2122/97 and G18, representing distinct genotypes currently circulating in the United Kingdom. These M. bovis strains exhibited differences
in survival and growth in bMDM. Although uptake was similar, the number of viable
intracellular AF2122/97 organisms increased rapidly, while G18 growth was constrained for the first 24 h. AF2122/97 infection induced a greater transcriptional response by bMDM than G18 infection with respect to the number of differentially expressed genes and the fold changes measured. AF2122/97 infection induced more
bMDM cell death, with characteristics of necrosis and apoptosis, more inflammasome
activation, and a greater type I interferon response than G18. In conclusion, the two
investigated M. bovis strains interact in significantly different ways with the host
macrophage. In contrast to the relatively silent infection by G18, AF2122/97 induces
greater signaling to attract other immune cells and induces host cell death, which
may promote secondary infections of naive macrophages. These differences may affect early events in the host-pathogen interaction, including granuloma development, which could in turn alter the progression of the disease. Therefore, the potential involvement of M. bovis genotypes in the reemergence of bovine tuberculosis in
the United Kingdom warrants further investigation.
Description
Publication history: Accepted - 8 December 2017; Published online - 20 December 2017.
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Article
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Keywords
Mycobacterium, cattle, host-pathogen interactions, macrophages
Citation
Jensen, K., Gallagher, I. J., Johnston, N., Welsh, M., Skuce, R., Williams, J. L. and Glass, E. J. (2018) ‘Variation in the Early Host-Pathogen Interaction of Bovine Macrophages with Divergent Mycobacterium bovis Strains in the United Kingdom’, Infection and Immunity. Edited by S. Ehrt, 86(3). doi: 10.1128/iai.00385-17.