Evaluating the cytokine profile of the WC1 + γδ T cell subset in the ileum of cattle with the subclinical and clinical forms of MAP infection.

In the present study, we evaluated expression of IFN-γ, IL-17, TNF-α, IL-10 and TGF-β by mucosal cells, including WC1 ⁺ γδ T cells, in ileal tissues taken from non-infected cattle and cattle naturally infected with Mycobacterium avium subsp paratuberculosis (MAP). Infected cattle were either in the subclinical or clinical stage of infection. We hypothesized that the cytokine profile of the WC1 ⁺ γδ T cell subset would be different between subclinical and clinical cattle. Our data indicate a significant increase in the numbers of WC1 ⁺ γδ T cells expressing IL-10 in clinical cattle compared to subclinical and non-infected cattle. We observed a significant increase in TGF-β expression by non-WC1 ⁺ cells in clinically infected cattle. Expression of IFN-γ, IL-17 and TNF-α in mucosal cells, including the WC1 ⁺ γδ T cell subset, was identified in all examined groups. However, our data indicate that the stage of infection did not significantly influence expression of these proinflammatory cytokines. This study demonstrates changes in the cytokine mRNA expression profile of mucosal cells in the ileum, and specifically WC1 ⁺ γδ T cells, as cattle progress to the clinical disease. The change is characterized by an increase in expression of anti-inflammatory cytokines.
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