Natural killer cells in psoriasis.

Psoriasis is one of the most common immune-mediated disorders. There is evidence that it is mediated by Th1 and, more recently, Th17 cells. The cytokine pattern, particularly the dominance of TNF-α, implicates the innate immune system in psoriasis pathogenesis. Of the many components of the innate immune system known to be involved in psoriatic lesions, natural killer and natural killer T cells appear to have a unique role. We review the evidence supporting a role for natural killer cells in psoriasis.