Bcl6 and NFkB cistromes mediate opposing reulation of the innate immune response

Here, using ChIP-seq, we define the NF-?B cistrome which is comprised of 31,070 cis-acting binding sites responsive to LPS-induced signaling. In addition, we demonstrate that the transcriptional repressor B-cell lymphoma 6 (Bcl-6) regulates nearly a third of the Tlr4-regulated transcriptome and that 90% of the Bcl-6 cistrome is collapsed following Tlr4 activation. Bcl-6 deficient macrophages are acutely hypersensitive to lipopolysaccharide (LPS) and, using comparative ChIP-seq analyses, we find that the Bcl-6 and NF-?B cistromes intersect, within nucleosomal distance, at nearly half of Bcl-6 binding sites in stimulated macrophages to promote opposing epigenetic modifications of the local chromatin. These results reveal a genomic strategy for controlling the innate immune response in which repressive and inductive cistromes establish a dynamic balance between macrophage quiescence and activation via epigenetically marked cis-regulatory elements. keywords: Genome-wide location analysis Overall design: Identification of BCL6 and NFkB binding sites in unstimulated and LPS-stimulated primary bone-marrow derived macrophages.