Critical role of the interleukin-23/T-helper 17 cell axis in the pathogenesis of psoriasis.

Psoriasis is an inflammatory disease with dynamic interactions between the immune system and the skin. Recent studies have demonstrated that the interleukin (IL)-23/T-helper (Th)17 cell axis plays an important role in the pathogenesis of psoriasis. Here, the biology and function of Th17 cells as well as the crucial role of IL-23 in the context of the Th17 cell-dependent chronic inflammation in psoriatic skins are reviewed. Recent study about the role of the IL-23/Th17 axis in the pathogenesis of psoriasis-like lesions in K5.Stat3C transgenic mice is also discussed. This model mouse for psoriasis not only verifies the therapeutic efficacies of biologics that specifically target the IL-23/Th17 axis, but also clarifies the pathogenesis of psoriasis.