Skin dendritic cells (DCs) are divided into several subsets with distinctive functions. This study shows a previously unappreciated role of dermal CD11b-type Langerin(-) DCs in maintaining immunological self-tolerance after UVB exposure. After UVB exposure, dermal CD11b-type Langerin(-) DCs upregulated surface CD86 expression, induced proliferation of Foxp3(+) regulatory T (Treg) cells without exogenous Ags, and upregulated a set of genes associated with immunological tolerance. This Treg-expansion activity was significantly hampered by CD80/CD86 blockade in vivo. These results indicate that CD11b-type Langerin(-) DCs from the UVB-exposed skin are specialized to expand Treg cells in the skin, which suppress autoimmunity.
- Journal Article