IL-10 inhibits miR-155 induction by Toll-like receptors.

Abstract

IL-10 is a potent anti-inflammatory cytokine that is crucial for down-regulating pro-inflammatory genes which are induced by Toll-like Receptor (TLR) signalling. In this study we have examined whether modulation of micro-RNAs play a role in the inhibitory effect of IL-10 on TLR4 signalling. Analysing miRNAs known to be induced by TLR4, we found that IL-10 could inhibit the expression of miR-155 in response to LPS, but had no effect on miR-21 or miR-146a. IL-10 inhibited miR-155 transcription from the BIC gene in a STAT3 dependent manner. This inhibitory effect of IL-10 on miR-155 led to an increase in the expression of the miR-155 target gene, SHIP1. This is the first example of IL-10 playing a role in miRNA function and suggests that through its inhibitory effect on miR-155, IL-10 has the ability to promote anti-inflammatory gene expression.