Project description:Sle2c1 is an NZM2410-derived lupus susceptibility locus that induces an expansion of the B1a cell compartment. B1a cells have a repertoire enriched for autoreactivity, and an expansion of this B cell subset occurs in several mouse models of lupus. Here we showed that expression of Sle2c1 enhances NZB cellular phenotypes that have been associated with autoimmune pathogenesis. A combination of genetic mapping and candidate gene analysis presents Cdkn2c, a gene encoding for cyclin kinase inhibitor p18INK4c (p18), as the top candidate gene for inducing the Slec2c1 associated expansion of B1a cells. A novel SNP in the Cdkn2c promoter is associated with a significantly reduced Cdkn2c expression in the splenic B cells and B1a cells from Sle2c1-carrying mice, which leads to defective G1 cell cycle arrest in splenic B cells and increased proliferation of Pc B1a cells. As cell cycle is differentially regulated in B1a and B2 cells, these results suggest that Cdkn2c play a critical role in B1a cell self renewal, and that its impaired expression leads to an accumulation of these cells with high autoreactive potential. Total RNA from peritoneal cavity B cells (B1a) and splenic B cells (Bs) was isolated, with 4 biological replicates each. Gene expression data from C57BL/6 mice were compared with data from B6.Sle2c1 mice.
Project description:Mouse peritoneal B1a cells were classified into two groups based upon the expression level of PC1. One is PC1 high group and the other is PC1 low. To evaluate gene expression patterns that distinguished PC1 high expressing B1a cells from PC1 low expressing B1a cells, we used Affymetrix GeneChipM-BM-. Mouse gene 1.0 ST Array. FACS-sorted PC1 high and low cells from individual mouse were used for RNA extraction and Affyarray hybridization. There were six independent biological replications in each group - six cases of PC1 high cells and six cases of PC1 low cells.
Project description:Gene expression profiling of murine irf4-/- and irf4+/+ splenic B cells identifies genes regulated by the transcription factor IRF4 in CD40+IL-4 activated mature B cells. B cells from 12-week old irf4-/- and irf4+/+ littermate mice were isolated by magnetic depletion of non-B cells from splenic mononuclear cells and cultures with mitogens in vitro. RNA was isolated. Labeled cRNA was hybridized to microarrays and genes specifically expressed in irf4-/- vs. irf4+/+ samples.
Project description:We report the characterization of a recurrent somatic mutation c.295T>C (p.C99R) in the Interferon Regulatory Factor 4 (IRF4) gene in human lymphoma in the α3-recognition helix of the IRF4 DNA-binding domain. IRF4-C99R fundamentally alters IRF4 DNA-binding, combining loss-of-binding at canonical IRF motifs and neomorph gain-of-binding at canonical and non-canonical IRF composite elements (CEs). IRF4-C99R thoroughly modifies IRF4 function, blocking IRF4-dependent plasma cell induction, and specifically up-regulating lymphoma-specific genes in a degenerate Activator Protein-1 (AP-1)-IRF-CE (AICE)-dependent manner.
Project description:Gene expression profiling of murine irf4-/- and irf4+/+ splenic B cells identifies genes regulated by the transcription factor IRF4 in quiescent mature B cells. B cells from 12-week old irf4-/- and irf4+/+ littermate mice were isolated by magnetic depletion of non-B cells from splenic mononuclear cells. RNA was isolated. Labeled cRNA was hybridized to microarrays and genes specifically expressed in irf4-/- vs. irf4+/+ samples.
Project description:Three ALCL cell lines DEL, FEPD and K299 were induced with an IRF4-specific shRNA for up to 96 hours. The three ALCL cell lines DEL, FEPD and K299 were induced with an IRF4-specific shRNA for four durations and compared with the corresponding not-induced control.
Project description:Amyloidogenic peptides are therapeutic in EAE, reducing systemic levels of IL6, TNF, and INFg. The fibrils are bound and endocytosed in peritoneal MFs and B1a cells. Differential gene expression was used to further understand the process. Groups of three female C57BL/6 mice were injected with 10ug of Tau 623-628, Amylin 28-33, LPS, or PBS. 30-40 minutes post injection, the peritoneal cavity was lavaged, CD11b high (MFs) and CD5+CD19+ (B1a lymphocytes) were purified by flow cytometry directly into Trizol. RNA was extracted from the aqueous phase using the Qiagen RNeasy microkits. RNA quality was assessed using the Agilent 2100 bioanalyzer and the RNA 6000 nano reagents kit. One color microarray, Agilent-028005 SurePrint G3 Mouse GE 8x60K Microarray, was performed at the human immune monitoring center. All samples were processed and run at the same time.
Project description:Interferon regulatory factor 4 (IRF4) is a master transcription factor required for the maturation of germinal center B cells that eventually develop into antibody secreting plasma cells and memory B cells. IRF4-deficient mice exhibit a profound reduction in serum immunoglobulin levels. In spite of wealth of the information relating to IRF4 and B cell biology, little is known about the intricate molecular details of the role of this transcription factor during B cell development. We therefore examined the genome-wide targets of IRF4 by ChIP-chip analysis in GC derived BL2 Burkittâs lymphoma cells. ChIP studies were further supplemented by whole genome expression analysis after shRNA-mediated knockdown of IRF4. Our study revealed that IRF4 regulates expression of genes important for a) BCR signaling b) antigen processing and presentation by MHC. In addition we found that IRF4 possibly in some way involved to regulate LTA, LTB and CXCR5 those involved in immune system development, particularly light zone development related genes such as FDC clustering regulating and IL21R and IL10 who are involved in B cell development.. On the other hand, IRF4 suppressesd genes in the oxidative phosphorylation pathway. Our findings illuminate hitherto unexplored roles of IRF4 in GC B cell development. BL2 Burkitt's lymphoma-derived B cells were infected with lentivirus expressing shRNA for IRF4 or control, and total RNA was subjected to Illumina BeadsExpression Arrays analysis.
Project description:To identify IRF4 transcription factor binding on chromatin at 5' regulatory regions of genes in myeloma cell line models. Keywords: binding site identification design Formaldehyde cross-linked, sonicated chromatin is prepared from cell lines Kms12 (test) and Ly19 (control). Chromatin immunoprecipated with anti-IRF4 antibody is labeled with Cy5 and co-hybridized on Agilent Human Promoter Set arrays with chromatin immunoprecipated with normal sera labeled with Cy3 . Two biological replicates were performed for the Kms12 and Ly19 experiments.
Project description:We demonstrate that transcription factor IRF4 is induced in a T cell receptor (TCR) affinity-dependent manner and functions as a dose-dependent regulator of the metabolic function of activated T cells. IRF4 regulates the expression of key molecules required for aerobic glycolysis of effector T cells, and is essential for clonal expansion and maintenance of effector function of antigen-specific CD8+ T cells. Examination of binding sites of transcription factor IRF4 in mouse CD8+ T cells.