Publication Date:
2012-04-12
Description:
Invariant natural killer T (iNKT) cells have the ability to rapidly secret cytokines in response to diverse stimuli, and therefore influence numerous immune reactions. Although IFN-γ and IL-4 are thought to dominate iNKT cytokine production, a distinct subset of iNKT cells, expressing RORγt and producing IL-17, has now been identified in both mice and humans. Although a role in pathogen and allergic responses has been assigned to the RORγt+ iNKT subset, factors controlling their development and function remain illusive. Here, we demonstrate that RORγt+ iNKT-cell differentiation obeys transforming growth factor-β (TGF-β) signaling control, different from that described for conventional iNKT cells. We reveal that TGF-β signaling, and particularly its SMAD4-dependent pathway, is required for both the survival of RORγt+ iNKT cells during their development and IL-17 production at the periphery. Moreover, constitutive TGF-β signaling in RORγt+ iNKT cells drives higher peripheral numbers and increased tissue distribution. Finally, we found that SMAD4-dependent TGF-β signaling is mandatory for the peripheral expansion of the RORγt+ iNKT cells responding to inflammatory signals. Thus, this work demonstrates that both the development and responsiveness of the newly described IL-17–producing iNKT cell subset is under the control of a dedicated TGF-β signaling pathway.
Print ISSN:
0006-4971
Electronic ISSN:
1528-0020
Topics:
Biology
,
Medicine
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