The increased protection and pathology in Mycobacterium tuberculosis-infected IL-27R-deficient mice is mediated by IL-17A

Einleitung: The IL-12 cytokine family member IL-27 has a broad inhibitory effect on Th1, Th2 and Th17 immune responses. With regard to Mycobacterium tuberculosis (Mtb) infection, we have previously shown that mice lacking the IL-27 receptor (IL-27R) have lower bacterial burdens in comparison to wildtype mice. However, IL-27R deficiency was associated with an accelerated death and an enhanced granulomatous response. Because IL-27R-deficient mice exhibit significantly increased numbers of IL-17A-secreting Th17 cells in their lungs, we analyzed whether the increased protection and/or pathology in the absence of IL-…