T helper 17 (Th17) cells play an important role in mucosal host defense through production of the signature cytokines IL-17 and IL-22. Prostaglandin E2 (PGE2) has been shown to enhance IL-17 production by mature Th17 cells. However, when present during Th17 cell differentiation, we found that PGE2 inhibited the transcription factor IRF4 and suppressed production of IL-17 but not IL-22. We show that IRF4 was required for IL-17 expression but inhibited IL-22 expression, highlighting the potential for discordant regulation of these two cytokines in Th17 cells.
The pathogenic fungus Cryptococcus neoformans produces PGE2, and we found that it uses PGE2- and IRF4-dependent mechanisms to specifically inhibit induction of IL-17 during Th17 cell differentiation.
Blockade of host PGE2 during infection led to increased IL-17 production from CD4(+) T cells and increased survival of mice.
These findings suggest that host- or pathogen-derived PGE2 can act directly on Th17 cells during differentiation to inhibit IL-17-dependent antimicrobial responses.
2012-04-23
Eng.
Bacterial Pathogenesis Unit, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Immunity. 2012 Apr;36(4):668-79
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