Contact allergens induce CD8+ T cell-derived interleukin 10 that appears dispensable for regulation of contact hypersensitivity.

Interleukin 10 (IL-10) has been implied in the regulation of allergic contact dermatitis. Using transcriptional reporter mice we analyzed cellular sources of IL-10 during contact hypersensitivity (CHS) and identified IL-10 expressing CD8+ T cells in the skin that are antigen-specific, display PD-1, an effector memory phenotype, and IL-10 expression comparable to that of CD4+ T cells. However, in mice with a selective IL-10 deficiency in CD8+ T cells CHS responses were comparable to that of controls, even in the absence of CD4+ cells, suggesting that CD8+ T cell-derived IL-10 does not contribute significantly to the resolution of CHS responses.