Project description:Human fetal γ-globin gene is developmentally silenced around the birth, and reactivation of γ-globin gene in adulthood sheds new light on ameliorating symptoms of hemoglobin disorders, such as sickle cell disease (SCD) and β-thalassemias. However, the precise regulation process of γ-globin remains incompletely understood. Here, we found that a new protein directly interacted with SOX6 and exerted a significant repression effect on the expression of γ-globin gene in erythroid cells. Further studies have demonstrated that it bound directly to γ-globin gene promoter via octamer binding motif, which in turn suppressed the transcriptional activity of γ-globin gene promoter. Thus, these data indicate that this new protein acts as a novel transcriptional repressor in the regulation of γ-globin gene expression through direct promoter binding, implying a potential alternative therapeutic target for the treatment of SCD and β-thalassemias.
Project description:We investigated the roles of IRF-3 and IRF-7 in innate antiviral immunity against dengue virus (DENV). Double-deficient Irf-3-/-7-/- mice infected with the DENV2 strain S221 possessed 1,000-150,000 fold higher levels of viral RNA than wild-type and single-deficient mice 24 hours after infection; however, they remained resistant to lethal infection. IFN-α/β was induced similarly in wild-type and Irf-3-/- mice post DENV infection, whereas in the Irf-7-/- and Irf-3-/-7-/- mice, significantly low levels of IFN-α/β expression was observed within 24 hours post-infection. IFN-stimulated gene (ISG) induction was also delayed in Irf-3-/-7-/- mice relative to wild-type and single-deficient mice. In particular, Cxcl10 and Ifnα2 were rapidly induced independently of both IRF-3 and IRF-7 in the Irf-3-/-7-/- mice with DENV infection. Higher levels of serum IFN-γ, IL-6, CXCL10, IL-8, IL-12 p70, and TNF were also observed in Irf-3-/-7-/- mice 24 hours after infection, at which time point viral titers peaked and started to be cleared. Antibody-mediated blockade experiments revealed that IFN-γ, CXCL10, and CXCR3 function to restrict DENV replication in Irf-3-/-7-/- mice. Additionally, the ISGs Cxcl10, Ifit1, Ifit3, and Mx2 can be induced via an IRF-3- and IRF-7-independent pathway that does not involve IFN-γ signaling for protection against DENV. Collectively, these results demonstrate that IRF-3 and IRF-7 are redundant, albeit IRF-7 plays a more important role than IRF-3 in inducing the initial IFN-α/β response; only the combined actions of IRF-3 and IRF-7 are necessary for efficient control of early DENV infection; and the late, IRF-3- and IRF-7-independent pathway contributes to anti-DENV immunity. To identify the antiviral genes that are controlled by IRF-3 and IRF-7 signaling during DENV infection, we examined a panel of ISG expression in the spleens of wild-type, Irf-3-/-, Irf-7-/- and Irf-3-/-7-/- mice at 12 or 24 hours after DENV infection using a quantitative PCR array kit. The fold changes in expression of 55 genes from infected mice were normalized to that of strain-matched naïve mice.
Project description:Pre-stimulation of MDMs with LPS (signals via MyD88 and TRIF dependent pathways) and PolyI:C (signals via a TRIF dependent pathway) leads to a reduced viral infection. In contrast, pre-stimulation with P3C (signals via MyD88 dependent pathway) does not lead to a reduced viral infection. This microarray was performed to find genes that are specifically upregulated in LPS and PolyI:C stimulated MDMs but not P3C stimulated MDMs. So to give us leads into the mechanism involved in the reduction of viral infection. MDMs of four different donors were stimulated for 4h with mock, LPS, PolyI:C or P3C. RNA was isolated and gene expression of these cells was assessed. Gene expression of LPS, PolyI:C and P3C stimulated MDMs was compared to mock.
Project description:<p>Hepatitis B virus (HBV) infection is a major risk factor for hepatocellular carcinoma (HCC). In this study we sequenced the whole genome (~80X) and transcriptome of tumor and non-tumor samples from four HCC patients and identified over two hundred HBV integration sites. We found significant clonal expansion of HBV-integrated hepatocytes specifically in the tumor samples. We observed a diverse collection of genomic perturbations near viral integration sites, including gene disruption, viral promoter-driven human transcription, viral-human transcript fusion and DNA copy number alteration. We also sequenced one patient at ultra-high coverage (~240X) to build the most comprehensive HBV-integration landscape yet attempted. Our data suggest that the viral integration significantly expands carcinogenic opportunities in HBV-infected individuals.</p>
Project description:Pre-stimulation of MDMs with LPS (signals via MyD88 and TRIF dependent pathways) and PolyI:C (signals via a TRIF dependent pathway) leads to a reduced viral infection. In contrast, pre-stimulation with P3C (signals via MyD88 dependent pathway) does not lead to a reduced viral infection. This microarray was performed to find genes that are specifically upregulated in LPS and PolyI:C stimulated MDMs but not P3C stimulated MDMs. So to give us leads into the mechanism involved in the reduction of viral infection.
Project description:Transcriptional profiling of HeLa cells comparing control untreated HeLa cells with IFN-gamma-treated HeLa cells To infect host cells, many viruses use small cellular compartments, called endosomes, for entry, and the thiol/disulfide interchange in viral envelope glycoproteins (Envs) is crucial for infection. By screening cysteine-reacting chemicals, we found a compound, 4,4’-dithiopyridine, which is active at acidic pH, efficiently restricts retrovirus vector infection. We thus hypothesized that some products of endosome-localized, interferon-stimulated genes (ISGs) exhibit anti-viral activity by inhibiting thiol/disulfide interchange in viral Envs. Among the hundreds of ISGs, gamma-interferon (IFN)-inducible lysosomal thiolreductase (GILT) is the only molecule that resides in the endosomes/lysosomes and digests the S-S bonds of proteins under acidic conditions. We now report that GILT significantly inhibits the replication of retroviruses, including HIV-1 and MLV, by restricting both the early and late phases of their life cycles. Using the VSV-G pseudotyped HIV-1 model, we found that GILT digests the S-S bonds of viral Env proteins. GILT also inhibits HIV-1 viral release by digesting the S-S bond of CD63, an endosome-localized molecule reportedly involved in HIV-1 particle release. The effect of -IFN on HIV-1 is limited, although GILT induced by gamma-IFN is supposed to have anti-HIV-1 activity. We found that while gamma-IFN effectively inhibits MLV replication through GILT, the gamma-IFN signaling is remarkably inhibited by the HIV-1 Env protein, but not the MLV Env protein. These findings suggest that GILT functions as an anti-viral host factor induced by gamma-IFN, however, HIV-1 may have evolved to inhibit gamma-IFN signaling by the Env protein.
Project description:Objective: Curing hepatitis B requires the complete elimination of covalently closed circular DNA (cccDNA). Interferon (IFN)-γ is produced by cytotoxic T lymphocytes and has noncytolytic antiviral potential; however, elimination of cccDNA could not be achieved. To enhance the regulatory effect of IFN-γ, we comprehensively analyzed the host factors that associated with cccDNA amplification and IFN-γ effects using the in vitro HBV infection system that exhibits various transcription levels. Design: Primary human hepatocytes were infected with HBV using genomic plasmids carrying the basic core promoter 1762/1764 and/or the precore 1896 mutation and treated with IFN-γ, IFN-α, and entecavir. Comprehensive expression analysis and functional studies were performed to analyze the host factors related to the cccDNA regulation using RNA microarray and siRNA analysis. Results: HBV infection system accurately reproduced the HBV life cycle and exhibited various transcription levels. Microarray analysis revealed that 53 genes increased depending on the cccDNA levels. Of 53 genes, the expression of IFN-induced protein 44-like (IFI44L) was the most upregulated by IFN-γ and IFN-α but not entecavir, and associated with the anti-viral effects of IFN-γ. siRNA analysis revealed that IFI44L negatively regulates the innate immune response and IFN-γ function to suppress HBV transcription and propagation by inhibiting the activation of NF-κB and STAT1 pathways.
Project description:Interferon-gamma (IFN-gamma) is a key cytokine in response to viral or intracellular bacterial infection in mammals. While a number of enhancers are described to promote IFN-gamma responses, no silencers for the Ifng gene have been identified. By examining H3K4me1 histone modification in naïve CD4+ T cells within Ifng locus, we identified an unrecognized silencer (CNS–28) that is responsible for restraining Ifng expression. Mechanistic study further demonstrates that CNS–28 maintains Ifng silence by diminishing enhancer-promoter interactions within Ifng locus in a T-bet independent manner. Functionally, CNS–28 restrains Ifng transcription in Th1, Tc1, and NK cells during both innate and adaptive immune responses. Moreover, CNS–28 deficiency resulted in repressed type 2 responses due to elevated IFN-gamma expression, shifting Th1 and Th2 paradigm. Thus, CNS–28 activity ensures immune cell quiescence by cooperating with other regulatory cis elements within the Ifng gene locus to minimize autoimmunity.
Project description:116,958 single-cell transcriptomes from samples of peripheral blood mononuclear cells (PBMCs) from five CVID patients at three distinct stages of the SARS-CoV-2 infection: 1) baseline, before viral infection, 2) progression, during viral infection, and 3) convalescence, once the viral infection had been resolved and the patient was PCR negative. CVID patients were under regular immunoglobulin replacement therapy and displayed only mild symptoms during SARS-CoV-2 infection.