“…In addition, recent therapeutic success with other biologics seems to have revealed the pivotal role of the TNF-α/interleukin (IL)-23/IL-17 axis in the pathogenesis of psoriasis (Figure). The initial trigger of psoriasis is thought to be the activation of plasmacytoid dendritic cells (DCs) being stimulated by complexes of host DNA and the antimicrobial peptide LL-37 (cathelicidin), which are produced by keratinocytes after minor injuries (8, 13-15). Activated plasmacytoid DCs and damaged keratinocytes produce interferon (IFN)-α and TNF-α, which results in the further production of TNF-α, IL-12 and IL-23 by plasmacytoids and recruited inflammatory DCs (8, 14, 15) (Figure).…”