Project description:Human moDC were treated with IFNβ and TNFα or the combination of both for either 1 h or 2.5 h in triplicate and profiled by gene expression microarray
Project description:Interferon (IFN) β and Tumor Necrosis Factor (TNF) α are key players in immunity against pathogens as well as in the development of autoinflammatory and autoimmune diseases. Accordingly, their molecular pathways have attracted much interest as therapeutic targets. Compelling evidence has shown that the antiviral and inflammatory transcriptional response induced by IFNβ is reprogrammed by crosstalk with TNFα. IFNβ typically induces interferon-stimulated genes by the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway leading to activation of the canonical ISGF3 transcriptional complex, composed of STAT1, STAT2 and IRF9. The signaling pathways engaged downstream of the combination of IFNβ and TNFα remain elusive, but previous observations suggested the existence of a response independent of STAT1. Here, using genome-wide transcriptional analysis by RNASeq, we observed a broad antiviral and immunoregulatory response initiated in the absence of STAT1 upon IFNβ and TNFα costimulation. Additional stratification of this transcriptional response with respect to the role of STAT2 and IRF9 revealed that they mediate the expression of a wide spectrum of genes. While a subset of genes was regulated by the concerted action of STAT2 and IRF9, other gene sets were independently regulated by STAT2 or IRF9. Collectively, our data supports a model in which STAT2 and IRF9 act through non-canonical parallel pathways to regulate distinct pool of genes in response to IFNβ and TNFα. This study provides novel insights into the molecular pathways leading to antiviral and immunoregulatory gene expression in conditions where elevated levels of both IFNβ and TNFα are present.
Project description:Type-I interferon signalling plays a critical role in immunity especially during viral infections. IFNAR1-deficent macrophages are highly resistant to Salmonella typhimurium (ST) infection and to the stimulation with LPS, poly I:C and TNFα. We have used microarray expression profiling on bone marrow derived macrophage cells as a discovery platform to identify genes that play a role in their resistance. Several genes were identified downregulated in IFNAR1-deficient macrophages compared to WT control sample. The Expression of identified genes will be quantified by qRT-PCR followed by knockdown of identified genes using si-RNA approach. The identified genes will help us to understand how IFNβ mediates susceptibility to bacterial infection in macrophages.
Project description:Among 830 TNFα-induced genes (at least 1.5 folds of upregulation in TNFα-treated TPC2-4 cells compared with control), the expression of 268 genes is significantly suppressed by JNKi treatment (TPC2-4 TNFα+JNKi/TPC2-4 TNFα, JNKi: JNK-IN-8, a kinase inhibitor specific for JNK (c-Jun N-terminal kinase) that inhibited phosphorylation of c-JUN)
Project description:Among 3,673 TNFα-induced gain of accessibility (at least 2 folds of upregulation in TNFα-treated TPC2-4 cells compared with control), and most of the gained peaks were significantly suppressed by JNKi treatment (TPC2-4 TNFα+JNKi/TPC2-4 TNFα, JNKi: JNK-IN-8, a kinase inhibitor specific for JNK (c-Jun N-terminal kinase) that inhibited phosphorylation of c-JUN)
Project description:Dendritic cells (DCs) are major antigen-presenting cells that play a key role in initiating and regulating innate and adaptive immune responses. DCs are critical mediators of tolerance and immunity. The functional properties of DCs changes with age. The purpose of this study was to define the age-associated molecular changes in DCs by gene array analysis using Affymatrix GeneChips. We identified up and down-regulated gene expression changes in DC from aged donors compared to young donors. Total 9 MoDC RNA samples from four young donors (20-27 years) and five aged donors (77-84 years) were analyzed using Affymetrix HG-U133A_2 Gene Arrays to compare differential gene expression changes in MoDC between aged and young groups
Project description:Mouse intestinal epithelial cells (IEC4.1 cells) were stimulated with TNFα (10 ng/ml) for 4h. The Agilent SurePrint G3 Mouse Gene Expression Microarray (G4852A) was used for the analysis, which provides full coverage of genes and transcripts with the most up-to-date content, including mRNAs and lincRNAs (http://www.chem.agilent.com/store/en_US/Prod-G4852A/G4852A). IEC4.1 cells were grown to 80% confluence for four groups: the siRNA control (Group A, cells treated with a non-specific scrambied siRNA control), the TNFα -stimulated (Group B, cells treated with the siRNA control plus TNFα stimulation), lincRNA-Cox2 siRNA (Group C, cells treated with an siRNA to lincRNA-Cox2), and lincRNA-Cox2 siRNA/ TNFα stimulated (Group D, cells treated with the lincNRA-Cox2 siRNA plus TNFα stimulation). Cells were treated with the siRNAs for 24h, followed by additional culture for 4h in the presence or absence of TNFα (10 ng/ml). Total RNAs were prepared with the RNeasy Mini kit (Qiagen) according to the manufacturer’s instruction (Ambion).
Project description:Cellular senescence is a key cell-fate program that leads to an essentially irreversible proliferative arrest in potentially damaged cells. Cytokine production and signaling play a significant role in senescence. Tumor necrosis factor-alpha (TNFα), an important pro-inflammatory cytokine secreted by some senescent cells, can induce senescence in mouse and human cells. However, downstream signaling pathways and key regulatory genes linking inflammation to senescence are not fully characterized. Using human umbilical vein endothelial cells (HUVECs) as a model, we show TNFα induces permanent growth arrest and increased senescence markers such as p21, p16, and senescence-associated β-galactosidase (SA-β-gal), accompanied by persistent DNA damage and ROS. By gene expression profiling and pathway analysis, we identify the crucial involvement of inflammatory networks, an interferon signature, and persistent activation of the Janus kinase (JAK) /signal transducer and activator of transcription (STAT) pathway in TNFα-mediated senescence. TNFα initiates a STAT-dependent autocrine loop leading to sustained inflammation, DNA damage, and expression of interferon response genes to lock cells into senescence. Further, we show STAT1/3 activation is necessary for cytokine and ROS production during TNFα-induced senescence. However, inhibition of STAT1/3 did not rescue cells from TNFα-mediated senescence. Rather, blockade of STAT activation accelerated senescence, suppressed genes that control the cell cycle, and modulated TNFα-induced senescence. Our findings suggest a positive feedback mechanism via a STAT pathway that sustains cytokine production and reveal a reciprocal regulatory role of JAK/STAT in TNFα-mediated senescence.