IL-10-producing type 1 regulatory T cells and allergy.

As an important subset of regulatory T (Treg) cells, IL-10-producing type 1 regulatory T cells (Tr1), have some different features to thymic-derived naturally occurring CD4+CD25+Foxp3+ Treg cells(nTreg cells). Similar to nTreg cells, Tr1 also play important roles in the control of allergic inflammation in several ways. There is a fine balance between Tr1 and Th2 responses in healthy subjects. Skewing of allergic-specific effector T cells to a Tr1 phenotype appears to be a critical event in successful allergen-specific immunotherapy and glucocorticoids and beta2-agonists treatment. Tr1 suppress Th2 cells and effector cells of allergic inflammation, such as eosinophils, mast cells, basophils, through producing IL-10, and perhaps TGF-beta. Understanding of Tr1 may be helpful in developing new strategies for treatment of allergic diseases.