Project description:The mass spectrometry data describes the phosphorylation of a transcription factor known as interferon regulatory factor 9 (IRF9), under IFNbeta-induced or non-induced conditions. IRF9 is involved in the transcriptional regulation of hundreds of interferon-stimulated genes as part of the innate immune response.
Project description:Wild type HIV-1 can infect macrophages to establish productive infection without triggering innate immune receptors or type 1 interferon responses that would otherwise restrict virus propagation. We found that HIV-1 capsid mutants that disrupt capsid interactions with two host factors CPSF6 and cyclophillin A do not replicate in macrophages because they do trigger interferon responses. Genome-wide transcriptional profiling was used to compare the repertoire of interferon stimulated genes induced by these capsid mutants after 24Êh with stimulation of macrophages with interferon-beta or with the RNA analogue Poly IC.
Project description:Innate immune responses induce hundreds of interferon-stimulated genes (ISGs), many of which play an important role in antiviral immunity. Viperin, a member of the radical SAM superfamily of enzymes, is the product of one such ISG and it restricts the replication of a broad spectrum of DNA and RNA viruses. However, a general mechanism that explains all the roles proposed for viperin in the innate immune response remains to be defined. Here we report a previously unknown antiviral mechanism, in which viperin represses translation of viral RNA. We show that viperin interacts with the translation machinery and, primarily through its radical SAM enzymatic activity, inhibits global translation during the interferon response by activating the eIF2 pathway. In cell based-infection assays, viperin inhibits viral protein synthesis and viral replication of Zika virus and Kunjin virus. This study illustrates the importance of translational repression in the antiviral response and identifies viperin as a central translational regulator in innate immunity.
Project description:Transcriptome profiles for innate and adaptive immune stimuli important for host response against mycobacteria. Human monocyte-derived macrophages were stimulated with TLR2/1 ligand and interferon-g, stimuli present during innate and adaptive immune responses, respectively.
Project description:B2_Mm2 acts as a STAT1 binding site and interferon inducible enhancer of the nearbby interferon-stimulated gene Dicer1 during an innate immune response (IFNG stimulated). J774 knockouts deficient of B2_Mm2 were also found to have downregulated expression of Serpina3f and Serpina3g, indicating that B2_Mm2 acts as an enhancer on these nearby genes likely due to its capability as a CTCF-binding site.
Project description:B2_Mm2 acts as a STAT1 binding site and interferon inducible enhancer of the nearbby interferon-stimulated gene Dicer1 during an innate immune response (IFNG stimulated). J774 knockouts deficient of B2_Mm2 were also found to have downregulated expression of Serpina3f and Serpina3g, indicating that B2_Mm2 acts as an enhancer on these nearby genes likely due to its capability as a CTCF-binding site.
Project description:The innate immune system is a two-edged sword; it is absolutely required for host defense against infection, but if left uncontrolled can trigger a plethora of inflammatory diseases. Here we used systems biology approaches to predict and validate a gene regulatory network involving a dynamic interplay between the transcription factors NF-κB, C/EBPδ, and ATF3 that controls inflammatory responses. We mathematically modeled transcriptional regulation of Il6 and Cebpd genes and experimentally validated the prediction that the combination of an initiator (NF-κB), an amplifier (C/EBPδ) and an attenuator (ATF3) forms a regulatory circuit that discriminates between transient and persistent Toll-like receptor 4-induced signals. Our results suggest a mechanism that enables the innate immune system to detect the duration of infection and to respond appropriately. Experiment Overall Design: Bone marrow-derived macrophages stimulated with LPS for 0, 20, 40, 60, 80, 120, 240 and 360 minutes.
Project description:Peste des petits ruminants virus (PPRV) infection causes highly contagious and severe disease in domestic and wild ruminants. It is widely reported that PRRV infection causes considerable innate immunosuppression in its host and promotes viral replication. However, how does the host rescue the innate immune response to counteract this immunosuppression during viral replication is poorly understood. The goat fetal fibroblasts (GFFs) have been commonly used as host-original cells to investigate the pathogenesis of PPRV. To explore the mechanisms of how host counteracts PPRV-mediated innate immunosuppression, a high-throughput quantitation proteomic approach (iTRAQ in conjunction with LC-MS/MS) was used to investigate the proteome landscape of GFFs in response to PPRV infection. Eventually, the proteomic analysis gained 497 up-regulated proteins and 358 down-regulated proteins (PPRV-infected cells versus mock-infected cells). The complement and coagulation cascades, protein digestion and absorption, and cytokine-cytokine receptor interaction pathways were significantly regulated in response to PPRV infection. ErmineJ analysis of the differentially expressed proteins (DEPs) identified the significantly enriched GO categories for response to interferon-gamma and positive regulation of ERK1 and ERK2 cascade. In addition, many immune related proteins, such as interferon gamma, 2'-5'-oligoadenylate synthase-like protein, toll-like receptor 9, toll-like receptor 6, NOD1, plasminogen activator inhibitor 1, and Wnt-5a were significantly upregulated. This suggested that the innate immune response was triggered during PPRV infection in GFFs. We subsequently identified that the E3 ubiquitin ligase FANCL was critically involved in regulation of the innate immune response during PPRV infection. FANCL inhibited PPRV infection by enhancing type I interferon (IFN) and interferon-stimulated genes (ISGs) expression. Further study indicated that FANCL induced type I IFN production by promoting TBK1 phosphorylation, and therefore impairing PPRV-mediated immunosuppression and revealing an antiviral function against PPRV.
Project description:The study shows that RLRs drive distinct immune gene activation and polarization of the immune response. In our data, the RLR-dependent, WNV-induced immune response polarization overshadows the classical drivers of viral innate immune responses, interferon I (IFN) and IFN-stimulated genes, thus underscoring the importance of innate immune activation for channeling the adaptive immune system into specific effector pathways
Project description:Recognition of pathogen-derived foreign nucleic acids is central to innate immune defense. This requires discrimination between structurally highly similar self and nonself nucleic acids to avoid aberrant inflammatory responses as in the autoinflammatory disorder Aicardi-Goutires syndrome (AGS). How vast amounts of self RNA are shielded from immune recognition to prevent autoinflammation is not fully understood. Here we show that SAM domain and HD domain-containing protein 1 (SAMHD1), one of the AGS-causing genes, functions as a single-stranded RNA (ssRNA) 3«exonuclease, the lack of which causes cellular RNA accumulation. Increased ssRNA in cells leads to dissolution of RNA-protein condensates, which sequester immunogenic double-stranded RNA (dsRNA). Release of sequestered dsRNA from condensates triggers activation of antiviral type I interferon via retinoic acid-inducible gene I-like receptors. Our results establish SAMHD1 as a key regulator of cellular RNA homeostasis and demonstrate that buffering of immunogenic self RNA by condensates regulates innate immune responses.