An inflammatory triangle in psoriasis: TNF, type I IFNs and IL-17

Psoriasis is a skin disease where various cytokines play a detrimental role, yet our understanding of the disease is still limited. TNF is a validated drug target in psoriasis and other autoimmune diseases, but its use is associated with side effects. Some paradoxical side effects of anti-TNF treatment are supposedly associated with type I IFNs, which are also implicated in the pathogenesis of psoriasis. Recently, the IL-23/IL-17 axis has been associated with psoriasis as well, and new drugs targeting this axis have already been developed. Findings suggest that these cytokines are interwoven. We discuss recent findings reinforcing the role of TNF, Type I IFNs and IL-17 in the pathogenesis of psoriasis and the apparent inflammatory interplay between these three cytokines.