ROR?-expressing T regulatory cells restrain allergic skin inflammation.

ABSTRACT: Atopic dermatitis is an allergic inflammatory skin disease characterized by the production of the type 2 cytokines in the skin by type 2 innate lymphoid cells (ILC2s) and T helper 2 (TH2) cells, and tissue eosinophilia. Using two distinct mouse models of atopic dermatitis, we show that expression of retinoid-related orphan receptor ? (ROR?) in skin-resident T regulatory cells (Tregs) is important for restraining allergic skin inflammation. In both models, targeted deletion of ROR? in mouse Tregs led to exaggerated eosinophilia driven by interleukin-5 (IL-5) production by ILC2s and TH2 cells. Expression of ROR? in skin-resident Tregs suppressed IL-4 expression and enhanced expression of death receptor 3 (DR3), which is the receptor for tumor necrosis factor (TNF) family cytokine, TNF ligand-related molecule 1 (TL1A), which promotes Treg functions. DR3 is expressed on both ILC2s and skin-resident Tregs Upon deletion of ROR? in skin-resident Tregs, we found that Tregs were no longer able to sequester TL1A, resulting in enhanced ILC2 activation. We also documented higher expression of ROR? in skin-resident Tregs than in peripheral blood circulating Tregs in humans, suggesting that ROR? and the TL1A-DR3 circuit could be therapeutically targeted in atopic dermatitis.

SUBMITTER: Malhotra N 

PROVIDER: S-EPMC5912895 | biostudies-literature | 2018 Mar

REPOSITORIES: biostudies-literature