Project description:To understand the differentiation program in monocyte/macrophage differentiation, we performed ChIP-seq for IRF8 and H3K4me1 together with gene expression profiling during IRF8-induced monocyte differentiation. Both promoter-proximal and -distal binding of IRF8 associated with induction of the genes especially those related to monocytes/macrophages and immunity. DNA motif analysis for cis-regulatory elements of indirect IRF8 target genes predicted KLF4, essential for Ly6C+ monocyte development, to be a downstream transcription factor regulating the indirect target gene expression. Introduction of KLF4 into an Irf8-/- myeloid progenitor cell line induced a subset of IRF8 target genes and partially induced monocyte/macrophage differentiation. Together, this study revealed the genome-wide behavior of IRF8 and the IRF8-KLF4 axis during monocyte differentiation. Gene expressions in monocyte-like cells differentiated by IRF8 or KLF4 were measured at day 4 after retroviral transductions to myeloid progenitor cell line, Tot2. Two independent experiments were performed.
Project description:To understand the differentiation program in monocyte/macrophage differentiation, we performed ChIP-seq for IRF8 and H3K4me1 together with gene expression profiling during IRF8-induced monocyte differentiation. Both promoter-proximal and -distal binding of IRF8 associated with induction of the genes especially those related to monocytes/macrophages and immunity. DNA motif analysis for cis-regulatory elements of indirect IRF8 target genes predicted KLF4, essential for Ly6C+ monocyte development, to be a downstream transcription factor regulating the indirect target gene expression. Introduction of KLF4 into an Irf8-/- myeloid progenitor cell line induced a subset of IRF8 target genes and partially induced monocyte/macrophage differentiation. Together, this study revealed the genome-wide behavior of IRF8 and the IRF8-KLF4 axis during monocyte differentiation.
Project description:The transcription factor (TF) interferon regulatory factor 8 (IRF8) controls both developmental and inflammatory stimulus-inducible genes in macrophages, but the mechanisms underlying these two different functions are largely unknown. One possibility is that these different roles are linked to the ability of IRF8 to bind alternative DNA sequences. We found that IRF8 is recruited to distinct sets of DNA consensus sequences before and after lipopolysaccharide (LPS) stimulation. In resting cells, IRF8 was mainly bound to composite sites together with the master regulator of myeloid development PU.1. Basal IRF8M-bM-^@M-^SPU.1 binding maintained the expression of a broad panel of genes essential for macrophage functions (such as microbial recognition and response to purines) and contributed to basal expression of many LPS-inducible genes. After LPS stimulation, increased expression of IRF8, other IRFs, and AP-1 family TFs enabled IRF8 binding to thousands of additional regions containing low-affinity multimerized IRF sites and composite IRFM-bM-^@M-^SAP-1 sites, which were not premarked by PU.1 and did not contribute to the basal IRF8 cistrome. While constitutively expressed IRF8-dependent genes contained only sites mediating basal IRF8/PU.1 recruitment, inducible IRF8-dependent genes contained variable combinations of constitutive and inducible sites. Overall, these data show at the genome scale how the same TF can be linked to constitutive and inducible gene regulation via distinct combinations of alternative DNA-binding sites. Chromatin immuno-precipitations of transcription factors IRF8, IRF1, PU.1, STAT1, STAT2 and of H3 lysine 27 acetylated followed by multiparallel sequencing, performed in bone marrow-derived macrophages from wild type (WT) and BXH2/TyJ mice. Cells were treated with lipopolysaccharide (LPS) for 2 or 4 hours, or interferon b (IFNb) for 30 or 60 minutes, 2 or 4 hours, or left unstimulated.
Project description:IThe transcription factor (TF) interferon regulatory factor 8 (IRF8) controls both developmental and inflammatory stimulus-inducible genes in macrophages, but the mechanisms underlying these two different functions are largely unknown. One possibility is that these different roles are linked to the ability of IRF8 to bind alternative DNA sequences. We found that IRF8 is recruited to distinct sets of DNA consensus sequences before and after lipopolysaccharide (LPS) stimulation. In resting cells, IRF8 was mainly bound to composite sites together with the master regulator of myeloid development PU.1. Basal IRF8M-bM-^@M-^SPU.1 binding maintained the expression of a broad panel of genes essential for macrophage functions (such as microbial recognition and response to purines) and contributed to basal expression of many LPS-inducible genes. After LPS stimulation, increased expression of IRF8, other IRFs, and AP-1 family TFs enabled IRF8 binding to thousands of additional regions containing low-affinity multimerized IRF sites and composite IRFM-bM-^@M-^SAP-1 sites, which were not premarked by PU.1 and did not contribute to the basal IRF8 cistrome. While constitutively expressed IRF8-dependent genes contained only sites mediating basal IRF8/PU.1 recruitment, inducible IRF8-dependent genes contained variable combinations of constitutive and inducible sites. Overall, these data show at the genome scale how the same TF can be linked to constitutive and inducible gene regulation via distinct combinations of alternative DNA-binding sites. Bone marrow cells isolated from C57BL/6 or BXH2/TyJ mice were plated in 10 cm plates in 5ml of BM-medium (high glucose DMEM supplemented with 20% low endotoxin fetal bovine serum, 30% L929-conditioned medium, 1% glutamine, 1%, Pen/Strep, 0.5% Sodium Pyruvate, 0.1% M-NM-2-mercaptoethanol). Cultures were fed with 2.5 ml of fresh medium every two days. Macrophages were subjected to different treatment (see individual samples for details). Total RNA was extracted from 5x106 cells using RNAeasy kit (Qiagen). Libraries were prepared from 1-2 M-BM-5g of RNA, after oligo-dT selection, using the TruSeq RNA sample preparation kit (Illumina).
Project description:Transposable elements (TE) have been shown to contrain functional transcription factor (TF) binding sites for long, but the extent to which TEs contribute TF binding sites is not well know. Here, we comprehensively mapped binding sites for 26 pairs of orthologous TFs, in two pairs of human and mouse cell lines (i.e., leukemia, and lymphoblast), along with epigenomic profiles representing DNA methylation and six histone modifications. We found that on average, 20% of TF binding sites were embedded in TEs. We further identified 710 TF-TE relationships in which certain TE subfamilies enriched for TF binidng sites. TE-derived TF binding peaks were also strongly associated with decreased DNA methylation and increased enhancer-associated histone marks. Most of the TE-derived TF binding sites were species-specific, but we also identified conserved binding sites. Additionally, 66% of TE-derived TF binding events were cell-type specific, associated with cell-type specific epigenetic landscape. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf To evaluate the contribution of transposable elements (TE) to transcription factor (TF) binding landscapes, we profiled ChIP-seq datasets for 26 TFs in two cell lines in human and mouse, generated by the ENCODE and MouseENCODE consortia. The epigenomic profiles were evaluated from six histone modification in each of the cell lines, also generated by the consortia. We added DNA methylation to the epigenomic profiles, using two complementary techniques, MeDIP-seq and MRE-seq. The mouse data related to this study are available through GSE57230: http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE57230
Project description:Transposable elements (TE) have been shown to contrain functional transcription factor (TF) binding sites for long, but the extent to which TEs contribute TF binding sites is not well know. Here, we comprehensively mapped binding sites for 26 pairs of orthologous TFs, in two pairs of human and mouse cell lines (i.e., leukemia, and lymphoblast), along with epigenomic profiles representing DNA methylation and six histone modifications. We found that on average, 20% of TF binding sites were embedded in TEs. We further identified 710 TF-TE relationships in which certain TE subfamilies enriched for TF binidng sites. TE-derived TF binding peaks were also strongly associated with decreased DNA methylation and increased enhancer-associated histone marks. Most of the TE-derived TF binding sites were species-specific, but we also identified conserved binding sites. Additionally, 66% of TE-derived TF binding events were cell-type specific, associated with cell-type specific epigenetic landscape. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf To evaluate the contribution of transposable elements (TE) to transcription factor (TF) binding landscapes, we profiled ChIP-seq datasets for 26 TFs in two cell lines in human and mouse, generated by the ENCODE and MouseENCODE consortia. The epigenomic profiles were evaluated from six histone modification in each of the cell lines, also generated by the consortia. We added DNA methylation to the epigenomic profiles, using two complementary techniques, MeDIP-seq and MRE-seq. The human data related to this study are available through GSE56774: http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE56774
Project description:The transcription factor (TF) interferon regulatory factor 8 (IRF8) controls both developmental and inflammatory stimulus-inducible genes in macrophages, but the mechanisms underlying these two different functions are largely unknown. One possibility is that these different roles are linked to the ability of IRF8 to bind alternative DNA sequences. We found that IRF8 is recruited to distinct sets of DNA consensus sequences before and after lipopolysaccharide (LPS) stimulation. In resting cells, IRF8 was mainly bound to composite sites together with the master regulator of myeloid development PU.1. Basal IRF8–PU.1 binding maintained the expression of a broad panel of genes essential for macrophage functions (such as microbial recognition and response to purines) and contributed to basal expression of many LPS-inducible genes. After LPS stimulation, increased expression of IRF8, other IRFs, and AP-1 family TFs enabled IRF8 binding to thousands of additional regions containing low-affinity multimerized IRF sites and composite IRF–AP-1 sites, which were not premarked by PU.1 and did not contribute to the basal IRF8 cistrome. While constitutively expressed IRF8-dependent genes contained only sites mediating basal IRF8/PU.1 recruitment, inducible IRF8-dependent genes contained variable combinations of constitutive and inducible sites. Overall, these data show at the genome scale how the same TF can be linked to constitutive and inducible gene regulation via distinct combinations of alternative DNA-binding sites.
Project description:IThe transcription factor (TF) interferon regulatory factor 8 (IRF8) controls both developmental and inflammatory stimulus-inducible genes in macrophages, but the mechanisms underlying these two different functions are largely unknown. One possibility is that these different roles are linked to the ability of IRF8 to bind alternative DNA sequences. We found that IRF8 is recruited to distinct sets of DNA consensus sequences before and after lipopolysaccharide (LPS) stimulation. In resting cells, IRF8 was mainly bound to composite sites together with the master regulator of myeloid development PU.1. Basal IRF8–PU.1 binding maintained the expression of a broad panel of genes essential for macrophage functions (such as microbial recognition and response to purines) and contributed to basal expression of many LPS-inducible genes. After LPS stimulation, increased expression of IRF8, other IRFs, and AP-1 family TFs enabled IRF8 binding to thousands of additional regions containing low-affinity multimerized IRF sites and composite IRF–AP-1 sites, which were not premarked by PU.1 and did not contribute to the basal IRF8 cistrome. While constitutively expressed IRF8-dependent genes contained only sites mediating basal IRF8/PU.1 recruitment, inducible IRF8-dependent genes contained variable combinations of constitutive and inducible sites. Overall, these data show at the genome scale how the same TF can be linked to constitutive and inducible gene regulation via distinct combinations of alternative DNA-binding sites.