Interferon-stimulated genes (ISGs) act in concert to provide a tight barrier against viruses. Recent studies have shed light on the contribution of individual ISG effectors to the antiviral state, ...but most have examined those acting on early, intracellular stages of the viral life cycle. Here, we applied an image-based screen to identify ISGs inhibiting late stages of influenza A virus (IAV) infection. We unraveled a directly antiviral function for the gene SERPINE1, encoding plasminogen activator inhibitor 1 (PAI-1). By targeting extracellular airway proteases, PAI-1 inhibits IAV glycoprotein cleavage, thereby reducing infectivity of progeny viruses. This was biologically relevant for IAV restriction in vivo. Further, partial PAI-1 deficiency, attributable to a polymorphism in human SERPINE1, conferred increased susceptibility to IAV in vitro. Together, our findings reveal that manipulating the extracellular environment to inhibit the last step in a virus life cycle is an important mechanism of the antiviral response.
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•SERPINE1/PAI-1 was identified as an unconventional ISG that acts extracellularly•PAI-1 inhibits influenza A virus (IAV) spread by inhibiting glycoprotein cleavage•Endogenous PAI-1 blocks IAV spread in human and murine cells, ex vivo and in vivo•PAI-1 potentially inhibits other viruses requiring extracellular maturation
Plasminogen activator inhibitor (PAI-1) blocks surface glycoprotein maturation of influenza A virus, thus reducing virus spread in the airways and revealing that the innate immune system, driven by type I IFN, uses modulation of the extracellular environment to inhibit viruses.
Mouse models of acute and chronic hepacivirus infection Billerbeck, Eva; Wolfisberg, Raphael; Fahnøe, Ulrik ...
Science (American Association for the Advancement of Science),
07/2017, Letnik:
357, Številka:
6347
Journal Article
Recenzirano
Odprti dostop
An estimated 71 million people worldwide are infected with hepatitis C virus (HCV). The lack of small-animal models has impeded studies of antiviral immune mechanisms. Here we show that an ...HCV-related hepacivirus discovered in Norway rats can establish high-titer hepatotropic infections in laboratory mice with immunological features resembling those seen in human viral hepatitis. Whereas immune-compromised mice developed persistent infection, immune-competent mice cleared the virus within 3 to 5 weeks. Acute clearance was T cell dependent and associated with liver injury. Transient depletion of CD4⁺ T cells before infection resulted in chronic infection, characterized by high levels of intrahepatic regulatory T cells and expression of inhibitory molecules on intrahepatic CD8⁺ T cells. Natural killer cells controlled early infection but were not essential for viral clearance. This model may provide mechanistic insights into hepatic antiviral immunity, a prerequisite for the development of HCV vaccines.
Control of both tissue architecture and scale is a fundamental translational roadblock in tissue engineering. An experimental framework that enables investigation into how architecture and scaling ...may be coupled is needed. We fabricated a structurally organized engineered tissue unit that expanded in response to regenerative cues after implantation into mice with liver injury. Specifically, we found that tissues containing patterned human primary hepatocytes, endothelial cells, and stromal cells in a degradable hydrogel expanded more than 50-fold over the course of 11 weeks in mice with injured livers. There was a concomitant increase in graft function as indicated by the production of multiple human liver proteins. Histologically, we observed the emergence of characteristic liver stereotypical microstructures mediated by coordinated growth of hepatocytes in close juxtaposition with a perfused vasculature. We demonstrated the utility of this system for probing the impact of multicellular geometric architecture on tissue expansion in response to liver injury. This approach is a hybrid strategy that harnesses both biology and engineering to more efficiently deploy a limited cell mass after implantation.
In most exposed individuals, hepatitis C virus (HCV) establishes a chronic infection; this long-term infection in turn contributes to the development of liver diseases such as cirrhosis and ...hepatocellular carcinoma. The role of antibodies directed against HCV in disease progression is poorly understood. Neutralizing antibodies (nAbs) can prevent HCV infection in vitro and in animal models. However, the effects of nAbs on an established HCV infection are unclear. We demonstrate that three broadly nAbs-AR3A, AR3B, and AR4A-delivered with adeno-associated viral vectors can confer protection against viral challenge in humanized mice. Furthermore, we provide evidence that nAbs can abrogate an ongoing HCV infection in primary hepatocyte cultures and in a human liver chimeric mouse model. These results showcase a therapeutic approach to interfere with HCV infection by exploiting a previously unappreciated need for HCV to continuously infect new hepatocytes to sustain a chronic infection.
Adeno-associated viral (AAV) vectors are currently being tested in multiple clinical trials for liver-directed gene transfer to treat the bleeding disorders hemophilia A and B and metabolic ...disorders. The optimal viral capsid for transduction of human hepatocytes has been under active investigation, but results across various models are inconsistent. We tested in vivo transduction in “humanized” mice. Methods to quantitate percent AAV transduced human and murine hepatocytes in chimeric livers were optimized using flow cytometry and confocal microscopy with image analysis. Distinct transduction efficiencies were noted following peripheral vein administration of a self-complementary vector expressing a gfp reporter gene. An engineered AAV3 capsid with two amino acid changes, S663V+T492V (AAV3-ST), showed best efficiency for human hepatocytes (~3-times, ~8-times, and ~80-times higher than for AAV9, AAV8, and AAV5, respectively). AAV5, 8, and 9 were more efficient in transducing murine than human hepatocytes. AAV8 yielded the highest transduction rate of murine hepatocytes, which was 19-times higher than that for human hepatocytes. In summary, our data show substantial differences among AAV serotypes in transduction of human and mouse hepatocytes, are the first to report on AAV5 in humanized mice, and support the use of AAV3-based vectors for human liver gene transfer.
p-Cresyl sulfate (PCS) is a risk factor of cardiovascular disease in patients with chronic kidney disease. Here we tested whether serum PCS levels were related to the rate and evolution of carotid ...atherosclerosis in hemodialysis patients and identified a potential mechanism. A total of 200 hemodialysis patients were categorized as with or without carotid atherosclerotic plaque and followed for 5 years. Serum PCS levels were found to be higher in patients with than without carotid atherosclerotic plaque and positively correlated with increased total plaque area during follow-up. Multiple logistic regression and mixed effects model analyses showed that serum PCS levels were independently associated with the incidence and progression of carotid atherosclerotic plaque. PCS induced inflammatory factor and adhesion molecule expression in endothelial cells and macrophages. In addition, PCS triggered monocyte-endothelial cell interaction in vitro and in vivo through increased production of reactive oxygen species. Compared with controls, increase of PCS levels produced by gavage promoted atherogenesis in 5/6-nephrectomized apoE−/− mice; a process attenuated by NADPH oxidase inhibitors. Thus, increased serum PCS levels are associated with the occurrence and progression of carotid atherosclerosis in hemodialysis patients and promote atherogenesis through increased reactive oxygen species production.
BackgroundThe role of microsatellite instability in the progression of endometrial cancer, a common cancer in women, has obtained increasing attentions in recent years. However, there are few studies ...regarding the association of microsatellite instability with clinicopathologic features and prognosis in patients with endometrial cancer.ObjectiveTo investigate the microsatellite instability and its clinical significance in patients with endometrial carcinoma.MethodsA total of 248 endometrial cancer patients who underwent surgery in Shiyan People's Hospital Affiliated to Hubei University of Medicine from January 2015 to December 2020 were selected. Their cancer tissue specimens were collected to detect the expression of MLH1, MSH2, MSH6 and PMS2 by immunohistochemistry. Relations of microsatellite instability with clinicopathologic features and prognosis were analyzed.ResultsThe rates of lost expression of MLH1, MSH2, MSH6 and PMS2 were 32.6% (78/239) , 22.2% (53/239) , 2.9% (7/239) and 65.7% (157/239) , respec
The host responds to virus infection by activating type I interferon (IFN) signaling leading to expression of IFN-stimulated genes (ISGs). Dysregulation of the IFN response results in inflammatory ...diseases and chronic infections. In this study, we demonstrate that IFN regulatory factor 2 (IRF2), an ISG and a negative regulator of IFN signaling, influences alphavirus neuroinvasion and pathogenesis. A Sindbis virus strain that in wild-type (WT) mice only causes disease when injected into the brain leads to lethal encephalitis in Irf2
mice after peripheral inoculation. Irf2
mice fail to control virus replication and recruit immune infiltrates into the brain. Reduced B cells and virus-specific IgG are observed in the Irf2
mouse brains despite the presence of peripheral neutralizing antibodies, suggesting a defect in B cell trafficking to the central nervous system (CNS). B cell-deficient μMT mice are significantly more susceptible to viral infection, yet WT B cells and serum are unable to rescue the Irf2
mice. Collectively, our data demonstrate that proper localization of B cells and local production of antibodies in the CNS are required for protection. The work advances our understanding of host mechanisms that affect viral neuroinvasion and their contribution to immunity against CNS infections.
Summary
Differentiation of CD4+ T cells into type 1 or type 2 subsets is mediated by the expression of the opposing lineage defining transcription factors T‐bet and GATA‐3. However, the existence of ...GATA‐3+ T‐bet+ CD4+ T cells in mice suggests functional plasticity of these subsets. Little is known about type 1 and type 2 plasticity of human T‐cell subsets in vivo. Here, we show that in the xenogeneic environment of humanized mice, which lacks a functional immune‐regulatory network, human CD4+ and, notably, CD8+ T cells preferentially differentiate into interleukin (IL)‐4+ GATA‐3+ and IL‐4+ interferon‐γ+ GATA‐3+ T‐bet+ subsets. Treatment with recombinant human IL‐12 or expansion of IL‐12‐producing human dendritic cells in vivo reverted this phenotype and led to the down‐regulation of GATA‐3 expression. These changes also correlated with improved antiviral immune responses in humanized mice. In conclusion, our study shows the capacity of human CD4+ and CD8+ T cells for stable co‐expression of GATA‐3 and T‐bet in humanized mice and reveals a critical role for IL‐12 in regulating this phenotype.
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