Analysis of TF binding sites and histone modification in IRF8-induced monocyte differentiation
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ABSTRACT: Chromatins were prepared from myeloid progenitor cell line Tot2 cells transduced with retrovirus for control MSCV or MSCV-IRF8. Chromatin immunoprecipitation (ChIP) was carried out by using anti-IRF8 antibody, anti-PU.1 antibody or anti-histone H3K4me1 antibody. ChIP-Seq peaks were identified using the FindPeaks tool in the HOMER package or SICER with input DNA tags as background distribution. Potential IRF8-direct target genes were identified based on ChIP-Seq and the alteration of expression by IRF8-induction. Examination of 2 transcription factor occupancy and 1 histone modifications in myeloid progenitor cells and monocyte-like cells differetiated by IRF8 expression
Project description:The transcription factor IRF8 is a critical regulator of plasmacytoid dendritic cell (pDC) and classical dendritic cell (cDC) development in both mouse and man. Yet the downstream molecular targets that regulate DC homeostasis and development are largely unknown. A recent study using gene expression analysis of IRF8-deficient myeloid and lymphoid progenitors identified the Myc paralog Mycl1 as a potential transcriptional target of IRF8. We report here that Mycl1 is a mediator of DC homeostasis at steady state and during inflammation, and its expression is regulated by IRF8 in multiple DC lineages. We have further validated these observations with ChIP-Seq of IRF8 binding to the Mycl1 locus. Notably, IRF8 binding to Mycl1 locus is independent of an interaction with the AP1 factor, BATF3. Additionally, our genome-wide survey of IRF8 binding identified both EICE and AICE motifs. Examination of IRF8 binding in dendritic cells
Project description:Upon antigen recognition B cells undertake a bifurcated response in which some cells rapidly differentiate into plasmablasts while others undergo affinity maturation in germinal centers (GC). We uncover a double negative feedback loop between interferon regulatory factors IRF4 and IRF8, which regulates the initial bifurcation of activated B cells as well as the GC response. IRF8 dampens BCR signaling, facilitates antigen specific interaction with helper T cells, and promotes selection of high affinity clones while antagonizing IRF4 driven plasmablast differentiation. Genomic analysis reveals concentration dependent action of IRF4 and IRF8 in regulating distinctive gene expression programs. Stochastic modeling suggests that the double negative feedback is sufficient to initiate bifurcating B cell developmental trajectories. Naïve B cells were isolated from Irf8+/+ (wild type, WT) mice spleen and activated in vitro with 10μg/ml LPS (Sigma). CD138hi IgMhi (IRF4hi*) cells and CD138lo IgMlo (IRF8hi*) cells were sorted by flow cytometry at 72 hours. Total RNA was prepared by using Rneasy Mini kit (Qiagen) and sequenced with Illumina HiSeq2500. Alignment was performed with Taphat2, and transcript abundance quantification using Cuffdiff function from Cufflinks. GC B cells were sorted from CD19cre/+ Irf8+/+ (Ctrl) or CD19cre/+ Irf8flox/flox (Irf8 cKO) mice on dpi 13 post NP-KLH immunization. Total RNA was prepared by using Rneasy Mini kit (Qiagen) and amplified with with Ovation RNA-Seq System v2 (NuGEN). The data were analyzed by Wardrobe. More details are provided in the manuscript.
Project description:The transcription factors Batf3 and IRF8 are required for development of CD8α+ conventional dendritic cells (cDCs), but the basis for their actions was unclear. Here, we identify two novel Zbtb46+ progenitors that separately generate CD8α+ and CD4+ cDCs and arise directly from the common DC progenitor (CDP). Irf8 expression in the CDP depends on prior PU.1-dependent autoactivation, and specification of pre-CD8 DC progenitors requires IRF8 but not Batf3. However, upon pre-CD8 DC specification, Irf8 autoactivation becomes Batf3-dependent at a CD8α+ cDC-specific enhancer containing multiple AP1-IRF composite elements (AICEs) within the Irf8 superenhancer. CDPs from Batf3-/- mice that specify toward pre-CD8 DCs fail to complete CD8α+ cDC development due to decay of Irf8 autoactivation, and divert to the CD4+ cDC lineage. Examination of histone modifications (H3K27ac and H3K4me1) and 2 transcription factors (Batf3 and Irf8) and the p300 co-factor binding in 3 different dendritic cell subsets
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:A) Chromatins were prepared from Cdx2-inducible ES cells cultured for 48 - 60 hours in the Dox+ and Dox- conditions. Chromatin immunoprecipitation (ChIP) was carried out by using anti-FLAG M2 affinity gel. ChIP product was tested by Western blotting using anti-FLAG antibody. Nuclear extract from ES cells cultured for 48 - 60 hours in Dox+ and Dox- condition was used for the Western blot. B) CDX2 ChIP-Seq peaks in the Hoxa7 gene region. UCSC Mouse Mm9 browser view of Hoxa7 gene locus after mapping CDX2 ChIP-Seq tags locations in the wiggle format. CDX2 ChIP-Seq peaks are shown in red color. C) Cdx2 ChIP-Seq result was verified by qPCR. Target genes were indicated in (G). Primers flanking a promoter region of Hbb-b1 and Pou5f1 as well as a gene desert region in chromosome 3 were used as negative controls. Primers flanking of Actb gene promoter were used for normalization. The relative enrichment of CDX2 binding was indicated as fold change. (D) CDX2-binding motifs identified with CisFinder using 200 bp sequences centered at ChIP sites. (F) Potential CDX2-direct target genes based on ChIP-Seq and the alteration of expression by Cdx2-overexpression. (G) Identification of CDX2 target genes by combining information on binding sites with gene expression response to Cdx2 over-expression Chromatin IP against CDX2-Flag fusion protein. MC1 ES cells were genetically modified for ROSA26 locus to have Tet-Off expression cassette for C-terminal FLAG tagged Cdx2. The peaks are obtained from the Eland Multi Alignment file. The number of tags in peaks was compared with the number of tags in the control sample for the same region corrected by the total coverage of tags. See supplemental file of the paper for details.
Project description:IRF8, a transcriptional factor, has the heightened expression in germinal center(GC) B cell and GC-origin B cell lymphoma. To identify IRF8 direct targets in GC B cells, ChIP-chip ananlysis was done in three different GC-origin diffuse large B cell lymphoma cell lines. IRF8-negative cell lines, MMS1, was also used as a negatvie control. IRF8 ChIP in three different cell lines (ODH1, VAL and LY1:high level of IRF8) and in one negative control cell lines (MMS1:negatvie for IRF8). Total four different samples. One sample per a set of two arrays (promoter1 and promoter2).
Project description:IRF8, a transcriptional factor, has the heightened expression in germinal center(GC) B cell and GC-origin B cell lymphoma. To identify IRF8 direct targets in GC B cells, ChIP-chip ananlysis was done in three different GC-origin diffuse large B cell lymphoma cell lines. IRF8-negative cell lines, MPC11, was also used as a negatvie control. IRF8 ChIP in three different cell lines (NFS201, NFS202 and NFS205:high level of IRF8) and in one negative control cell lines(MPC11:negatvie for IRF8). Total four different samples. One sample per a set of two arrays (promoter1 and promoter2).
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:This SuperSeries is composed of the following subset Series: GSE30357: Chip-chip from human diffuse large B cell lymphoma cell lines with IRF8 GSE30358: Mouse B cell lymphoma cell lines:IRF8 knockdown cells vs. Control GSE30519: Chip-chip from mouse diffuse large B cell lymphoma cell lines with IRF8 GSE30520: Chip-chip from mouse diffuse large B cell lymphoma cell lines with PU.1 Refer to individual Series