Inhibition of inflammatory gene transcription by IL-10 is associated with rapid suppression of LPS-induced enhancer activation [stat3_ChIP]

IL-10 limits the magnitude of inflammatory gene expression following microbial stimuli and is essential to prevent inflammatory disease, however, the molecular basis for IL-10 mediated inhibition remains elusive. Using a genome-wide approach we demonstrate that inhibition of transcription is the primary mechanism for IL-10-mediated suppression in LPS-stimulated macrophages, and that inhibited genes can be divided into two clusters. Genes in the first cluster are inhibited only if IL-10 is included early in the course of LPS stimulation and is strongly enriched for interferon-inducible genes. Genes in the second cluster can be rapidly suppressed by IL-10 even after transcription is initiated, and this is associated with suppression of LPS-induced enhancer activation. Interestingly, the ability of IL-10 to rapidly suppress active transcription exhibits a delay following LPS stimulation. Thus, a key pathway for IL-10 mediated suppression involves rapid inhibition of enhancer function during the secondary phase of the response to LPS. Overall design: Murine bone marrow derived macrophage pools were stimulated with IL-10 for 30 min, LPS for 195 min, or LPS for 195 min with the adddition of IL-10 for the last 30 min. ChIP-Seq performed for STAT3