Description
L-19 and IL-20 are mainly produced by activated monocytes, IL-24 is produced by Th2 cells, monocytes, and melanocytic cells, and IL-22 and IL-26 are primarily produced by activated T cells. Like IL- 10, these class II cytokines signal through heterodimeric receptors. Overexpression of IL-20 in transgenic mice causes neonatal death as well as skin abnormalities, including aberrant epidermal differentiation. IL-20 selectively enhances multipotential hematopoietic progenitors in vitro and in vivo. IL-20 is preferentially expressed in monocytes18 and induces STAT 3 activation through binding to 2 types of IL-20 receptor (R) complexes, either IL- 20R1/IL-20R2 or IL-22R1/IL- 20R2