The murine liver is a potential target organ for IL-19, IL-20 and IL-24: Type I Interferons and LPS regulate the expression of IL-20R2

Background/Aims: The biological functions of the recently discovered IL-10-related cytokines IL-19, IL-20, IL-22, IL-24 and their receptors IL-20R1, IL-20R2 and IL-22R are not clear. Therefore, the expression of these cytokines and their receptors in the hepatic acute phase response to LPS was analysed. Type I interferons have important immunomodulatory functions in bacterial infections. We investigated if they influence release and organ-specific expression of TNF, IL-6 and IL-10 and the responsiveness of liver to IL-10 related cytokines during the reaction to LPS in vivo. Methods: B6 and congenic IFNAR(-/-) mice were intraperitoneally injected with 5 mg/kg LPS. Systemic release of cytokines was quantified by ELISA. Organ-specific expression of cytokines and their receptors was evaluated by (semi quantitative or quantitative) RT-PCR. Results: The cytokines IL-19, IL-22 and the IL-20R2 receptor subunit are up-regulated by LPS in the liver of normal mice. IFN alpha/beta enhance the secretion and expression of IL-6 and IL-10 during the response to LPS, but also the up-regulation of IL-20R2 expression. Conclusions: We show that the liver is a potential target for IL-19, IL-20 and IL-24. During an LPS response, IFN alpha/beta influence cytokine secretion and expression and possibly the response to IL-19 and IL-24. (c) 2006 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.