Project description:Transcriptional response to virus infection in mice lacking type I and type III signaling The transcriptional response to virus infection is thought to be predominantly induced by interferon (IFN) signaling. Here we demonstrate that, in the absence of IFN signaling, an IFN-like transcriptome is still maintained. This transcriptional activity is mediated from IFN-stimulated response elements (ISREs) that bind to both the IFN stimulated gene factor 3 (ISGF3) as well as to IFN response factor 7 (IRF7). Through a combination of both in vitro biochemistry and in vivo transcriptional profiling, we have dissected what constitutes IRF-specific, ISGF3-specific, or universal ISREs. Taken together, the data presented here suggests that IRF7 can induce an IFN-like transcriptome in the absence of type-I or -III signaling and therefore provides a level of redundancy to cells to ensure the induction of the antiviral state. Mouse: Infections were performed in triplicate and lungs from each condition were pooled for total RNA isolation. Human: Analysis of IRF7 transcriptome in U3A cell line was performed in duplicates.
Project description:Transcriptional response to virus infection in mice lacking type I and type III signaling The transcriptional response to virus infection is thought to be predominantly induced by interferon (IFN) signaling. Here we demonstrate that, in the absence of IFN signaling, an IFN-like transcriptome is still maintained. This transcriptional activity is mediated from IFN-stimulated response elements (ISREs) that bind to both the IFN stimulated gene factor 3 (ISGF3) as well as to IFN response factor 7 (IRF7). Through a combination of both in vitro biochemistry and in vivo transcriptional profiling, we have dissected what constitutes IRF-specific, ISGF3-specific, or universal ISREs. Taken together, the data presented here suggests that IRF7 can induce an IFN-like transcriptome in the absence of type-I or -III signaling and therefore provides a level of redundancy to cells to ensure the induction of the antiviral state.
Project description:The transcriptional response to virus infection is thought to be predominantly induced by interferon (IFN) signaling. Here we demonstrate that, in the absence of IFN signaling, an IFN-like transcriptome is still maintained. This transcriptional activity is mediated from IFN-stimulated response elements (ISREs) that bind to both the IFN-stimulated gene factor 3 (ISGF3) as well as to IFN response factor 7 (IRF7). Through a combination of both in vitro biochemistry and in vivo transcriptional profiling, we have dissected what constitutes IRF-specific, ISGF3-specific, or universal ISREs. Taken together, the data presented here suggest that IRF7 can induce an IFN-like transcriptome in the absence of type-I or -III signaling and therefore provides a level of redundancy to cells to ensure the induction of the antiviral state.
Project description:In this work, we aimed at studying the impact of microRNAs on antiviral responses, using inducible deletion of one or two copies of Dicer1 (in Dicer-floxed x EsrCRE+ MEFs). Unexpectedly, we discovered that Cre-ERT activation by hydroxytamoxifen (OHT) alone, independent of Dicer1 deletion, had a strong impact on antiviral responses. These microarrays were performed on SV40 immortalized Dicer1 fl/fl EsrCRE+ MEFs, Dicer1 fl/wt EsrCRE+ MEFs, 96 h after initial OHT treatment, and SV40 immortalized Dicer1 wt/wt EsrCRE+ MEFs, Dicer1 wt/wt EsrCRE-neg MEFs (Wild Type MEFs), 48 h after initial OHT treatment. These analyses revealed the strong induction of several antiviral genes (Rsad2, Cxcl10...), following Cre-ERT activation. SV40 immortalized mouse embryonic fibroblasts from various genotypes were stimulated 24h with 500nM hydroxytamoxifen, and further expanded for 24 or 72h. Each sample was analyzed on Agilent-028005 SurePrint G3 Mouse GE 8x60K Microarray Each sample is in simplicate - no biological replicates; sample 1-4 were processed/analyzed on a different microarray slide to 5-8 (different day/operator)
Project description:In this work, we aimed at studying the impact of microRNAs on antiviral responses, using inducible deletion of one or two copies of Dicer1 (in Dicer-floxed x EsrCRE+ MEFs). Unexpectedly, we discovered that Cre-ERT activation by hydroxytamoxifen (OHT) alone, independent of Dicer1 deletion, had a strong impact on antiviral responses. These microarrays were performed on SV40 immortalized Dicer1 fl/fl EsrCRE+ MEFs, Dicer1 fl/wt EsrCRE+ MEFs, 96 h after initial OHT treatment, and SV40 immortalized Dicer1 wt/wt EsrCRE+ MEFs, Dicer1 wt/wt EsrCRE-neg MEFs (Wild Type MEFs), 48 h after initial OHT treatment. These analyses revealed the strong induction of several antiviral genes (Rsad2, Cxcl10...), following Cre-ERT activation.
Project description:Upon recognition of aberrantly located DNA, the innate immune sensor cGAS activates STING/IRF-3-driven antiviral responses. Here we characterized the ability of a specific variant of the cGAS-encoding gene MB21D1, rs610913, to alter cGAS-mediated DNA sensing and viral infection. rs610913 is a frequent G>T polymorphism resulting in a P261H exchange in the cGAS protein. Data from the International Collaboration for the Genomics of HIV suggested that rs610913 nominally associates with HIV-1 acquisition in vivo. Molecular modeling of cGAS(P261H) hinted towards the possibility for an additional binding site for a potential cellular co-factor in cGAS dimers. However, cGAS(WT) or cGAS(P261H)-reconstituted THP-1 cGAS KO cells shared steady-state expression of interferon-stimulated genes (ISGs), as opposed to cells expressing the enzymatically inactive cGAS(G212A/S213A). Accordingly, cGAS(WT) and cGAS(P261H) cells were less susceptible to lentiviral transduction and infection with HIV-1, HSV-1, and Chikungunya virus as compared to cGAS KO- or cGAS(G212A/S213A) cells. Upon DNA challenge, innate immune activation appeared to be mildly reduced upon expression of cGAS(P261H) compared to cGAS(WT). Finally, DNA challenge of PBMCs from donors homozygously expressing rs610913 provoked a trend towards a slightly reduced type I IFN response as compared to PBMCs from GG donors. Taken together, the steady-state activity of cGAS maintains a base-line antiviral state rendering cells more refractory to ISG-sensitive viral infections. rs610913 failed to grossly differ phenotypically from the wild-type gene, suggesting that cGAS(P261H) and wild-type cGAS share a similar ability to sense viral infections in vivo.
Project description:Genetic Redundancy of GATA Factors in Extraembryonic Trophoblast Lineage Ensures Progression of both Pre and Postimplantation Mammalian Development
Project description:GATA transcription factors are implicated in establishing cell fate during mammalian development. In early mammalian embryos, GATA3 is selectively expressed in the extraembryonic trophoblast lineage and regulates gene expression to promote trophoblast fate. However, trophoblast-specific GATA3 function is dispensable for early mammalian development. Here, using dual conditional knockout mice, we show that genetic redundancy of GATA3 with paralog GATA2 in trophoblast progenitors ensures the successful progression of both pre and postimplantation mammalian development. Stage-specific gene deletion in trophoblasts reveals that loss of both GATA genes, but not either one alone, leads to embryonic lethality prior to the onset of their expression within the embryo proper. Using ChIP-seq and RNA-seq analyses, we define the global targets of GATA2/GATA3 and show that they directly regulate a large number of common genes to orchestrate stem vs. differentiated trophoblast fate. Also, in trophoblast progenitors GATA factors directly regulate BMP4, Nodal and Wnt signaling components that promote embryonic-extraembryonic signaling cross-talk, essential for the development of the embryo proper. Our study provides genetic evidence that impairment of trophoblast-specific GATA2/GATA3 function could lead to early pregnancy failure.