IL-19, IL-20 and IL-24: potential therapeutic targets for autoimmune diseases.

IL-19, IL-20 and IL-24 are members of the IL-10 family of cytokines, the human IL-19, IL-20 and IL-24 genes are all located on the q32 region of chromosome 1, and the three cytokines also share a common receptor IL-20R1/IL-20R2 heterodimer. These cytokines due to the similarity and shared receptor usage, are quite overlapping in function. Recently, the available evidence has indicated that interaction of these cytokines with their receptors might exhibit pro-inflammatory effects on autoimmune diseases, particularly psoriasis and rheumatoid arthritis. Since an imbalance between anti- and pro-inflammatory cytokines contribute to the development of autoimune diseases, these cytokines may be implicated in the pathogenesis of autoimmunity. In this paper, we concisely discuss the biological features of IL-19, IL-20 and IL-24, and focus on their potential roles in autoimmune diseases. Hopefully the information obtained will lead to a better understanding of the pathogenesis and development of novel therapeutic strategies for autoimmune diseases.