DC activated via dectin‐1 convert Treg into IL‐17 producers

F Osorio, S LeibundGut‐Landmann… - European journal of …, 2008 - Wiley Online Library
F Osorio, S LeibundGut‐Landmann, M Lochner, K Lahl, T Sparwasser, G Eberl…
European journal of immunology, 2008Wiley Online Library
Th cells producing IL‐17 play a pro‐inflammatory role at mucosal surfaces. Treg at the same
sites dampen inflammation and prevent immunopathology. Th cells producing IL‐17 (Th17)
and Treg are thought to be distinct populations defined by expression of the transcription
factors ROR‐γt and Foxp3, respectively. Here, we show that mouse CD25+ Foxp3+ Treg can
be converted into a hybrid T‐cell population characterized by the expression of Foxp3 and
ROR‐γt and the production of IL‐17. Conversion was observed upon coculture with DC …
Abstract
Th cells producing IL‐17 play a pro‐inflammatory role at mucosal surfaces. Treg at the same sites dampen inflammation and prevent immunopathology. Th cells producing IL‐17 (Th17) and Treg are thought to be distinct populations defined by expression of the transcription factors ROR‐γt and Foxp3, respectively. Here, we show that mouse CD25+Foxp3+ Treg can be converted into a hybrid T‐cell population characterized by the expression of Foxp3 and ROR‐γt and the production of IL‐17. Conversion was observed upon coculture with DC selectively activated via dectin‐1, a C‐type lectin receptor involved in fungal recognition, and depended on IL‐23 produced by DC. Within the Foxp3+ population, only Foxp3+ROR‐γt+ T cells but not Foxp3+ROR‐γt–T cells become Foxp3+IL‐17+ T cells. These results indicate that some Foxp3+ T cells can produce IL‐17 while retaining Foxp3 expression and suggest that Treg could play an unexpected pro‐inflammatory role in some settings.
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