IL-31
which produced by activated Th2-type T cells. IL-31 signals through a receptor
composed of IL-31 receptor A and oncostatin M receptor. IL-31 activates STAT3
and possibly STAT1 and STAT5 through the IL31 heterodimeric receptor composed
of IL31RA and OSMR. IL-31 has also been identified as a major player in a
number of chronic inflammatory diseases, including atopic dermatitis. Patients
with atopic dermatitis, chronic spontaneous urticaria, allergic contact
dermatitis, prurigo nodularis, primary cutaneous lymphoma and mastocytosis
exhibit increased serum levels of IL-31 protein and elevated IL-31 mRNA in the
skin.