Interleukin-19 as an immunoregulatory cytokine.

IL-19 is a type of anti-inflammatory cytokine. Since the receptor for IL-19 is common to IL-20 and IL-24, it is important to clarify the role of each of the three. If three different cytokines bind to the same receptor, these three may have been produced to complement the other two. However perhaps it is unlikely. Recently, the existence of a novel receptor for IL-19 was suggested. The distinction between the three roles still makes sense. On the other hand, because T cells do not produce IL-19, their role in acquired immunity is limited or indirect. It has been reported that IL-19 causes inflammation in some diseases but is not an anti-inflammatory effect. In this review, we introduce the current role of IL-19 in each disease. In addition, we will describe the molecular mechanism of IL-19 and its development for prevention. IL-19 was previously considered an anti-inflammatory cytokine, but we would like to propose what we call an immunoregulatory cytokine.