Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/22/2015
Publication Date: 1/22/2015
Citation: Palmer, M.V., Waters, W.R., Thacker, T.C. 2015. In situ cytokine expression in pulmonary granulomas of cattle experimentally infected by aerosolized Mycobacterium bovis [abstract]. In Proceedings of the Keystone Symposium; Granulomas in Infectious and Non-infectious Diseases, January 22-27, 2015, Santa Fe, New Mexico. p. 141.
Technical Abstract: Mycobacterium bovis is the cause of tuberculosis in most animal species, including cattle and is a serious zoonotic pathogen. In humans, M. bovis infection can result in disease clinically indistinguishable from that caused by Mycobacterium tuberculosis, the cause of most tuberculosis in humans. Regardless of host, the typical lesion induced by M. bovis or M. tuberculosis is the tuberculoid granuloma. Tuberculoid granulomas are dynamic structures reflecting the interface of host and pathogen and; therefore, pass through various morphological stages, categorized as stages I through IV. Using a novel in situ hybridization assay, mRNA expression of various cytokines and chemokines were examined qualitatively and quantitatively using image analysis. In experimentally infected cattle, pulmonary granulomas were examined approximately 150 days after aerosol exposure to M. bovis. Expression of mRNA for IFN-gammma, IL-17A, TNF-alpha, IL-10, CXCL9 and CXCL10 did not differ between granulomas of different stages. However, relative expression of the various cytokines was characteristic of a Th1 response with high TNF-alpha, intermediate IFN-gamma and low IL-10 expression. Expression of the chemokines CXCL9 and CXCL10 was high, suggestive of granulomas actively involved in T-cell chemotaxis.