A New Perspective on IL-17 Producing Cell Infiltration in Atopic Dermatitis: Role of CCL20 Production Observed in an in vitro Scratched Keratinocyte Model

Abstract

Recent studies have demonstrated a Th2 cytokine-prone inflammation in the lesional skin of atopic dermatitis. The lesional infiltration of IL-17-producing immune cells is also evident, but the implication of their infiltration remains elusive in AD. Using an in vitro scratched keratinocyte model, we investigated the effects of "scratch" on the CCL20 production, which is a cardinal chemokine for CCR6+IL-17-producing cells. We found that the scratch injury selectively upregulated the CCL20 production from an in vitro keratinocyte sheets. Notably, IL-4 and IL-13 did not affect the scratch-induced CCL20 production. These results suggest that the infiltration of IL-17-producing cells may be attributable to scratch-induced CCL20 production, but not to the Th2-prone milieu.