Research

IL-19

The cytokine IL-19 is a member of the IL-10 family that includes IL-20, IL-22 (IL-TIF), IL-24 (MDA-7), and IL-26 (AK155). Among IL-10 family, IL-19 binds a receptor that is formed by a heterodimer of IL-20 receptor1 (IL-20R1) and 2 (IL-20R2). Binding of IL-19 to its receptor complex activates the signal transducers and activators of transcription (STAT) pathways, notably, STAT1 and STAT3. Recent studies have shown that IL-19 is produced by keratinocytes, epithelial cells, macrophages, and B-cells. Little is known about the exact biological role of IL-19 in the immunological regulation, however, although there is an increasing body of data demonstrating that IL-19 is associated with the development of Th2 responses including asthma and the pathogenesis of psoriasis.

My group studies the immunological function of Interleukin-19. We have used IL-19 gene knockout mice using the VelociGene approach. Thus, I showed that IL-19-deficient mice are more susceptible to experimental acute colitis induced by dextran sulfate sodium (DSS), and this increased susceptibility is correlated with the accumulation of macrophages and the increased production of IFNgamma, IL-1beta, IL-6, IL-12, TNF-alpha and KC. By the in vitro clture, we elucidated cytokine productions of IL-1beta, IL-6, IL-12, and TNF-alpha in IL-19-deficient macrophages were enhanced on stimulation of LPS. Thus, IL-19 has roles in mucosal protection and acute inflammation in the colon.