Gene transcription studies have identified dual roles for the
cytokines IL-17A and
IL-22 in
bovine tuberculosis, where they show potential as both predictors of
vaccine success and correlates of
infection. To allow for a detailed investigation of the cell populations responsible for production of these
cytokines, we have utilised a novel bovine
IL-22 specific recombinant antibody for flow cytometry. Bovine
tuberculin (PPDB) induced greater
IL-22 and
IL-17A production in Mycobacterium bovis (M. bovis)-infected cattle compared to non-infected controls, while PWM-induced
cytokine levels were similar between the two groups. In M. bovis-infected animals, PPDB specific
IL-22 and
IL-17A responses were observed in both CD4+ T cell and γδ T cell populations. Although both
cytokines were detected in both cell types, IL-22/IL-17A double producers were rare and confined mainly to the γδ T cell population. These results support previous gene transcription studies and extend the observation of increased
IL-22 and
IL-17A responses in M. bovis-infected animals to the level of
protein production. We were also able to characterise the cell populations responsible for these disease-related
cytokine responses. The data generated can be used to further our understanding of the immunopathology of
bovine tuberculosis and to produce more sensitive and specific immune-diagnostic
reagents.