bims-mevinf 2025-06-22 papers

J Neuroinflammation. 2025 Jun 14. 22(1): 157

Changes in metabolite profiles in the cerebrospinal fluid and in human neuronal cells upon tick-borne encephalitis virus infection.

Satoshi Suyama, Sally Boxall, Benjamin Grace, Andrea Fořtová, Martina Pychova, Lenka Krbkova, Rupasri Mandal, David Wishart, Diane E Griffin, Daniel Růžek, Niluka Goonawardane.

BACKGROUND: Tick-borne encephalitis virus (TBEV) is a significant threat to human health. The virus causes potentially fatal disease of the central nervous system (CNS), for which no treatments are available. TBEV infected individuals display a wide spectrum of neuronal disease, the determinants of which are undefined. Changes to host metabolism and virus-induced immunity have been postulated to contribute to the neuronal damage observed in infected individuals. In this study, we evaluated the cytokine, chemokine, and metabolic alterations in the cerebrospinal fluid (CSF) of symptomatic patients infected with TBEV presenting with meningitis or encephalitis. Our aim was to investigate the host immune and metabolic responses associated with specific TBEV infectious outcomes.
METHODS: CSF samples of patients with meningitis (n = 27) or encephalitis (n = 25) were obtained upon consent from individuals hospitalised with confirmed TBEV infection in Brno. CSF from uninfected control patients was also collected for comparison (n = 12). A multiplex bead-based system was used to measure the levels of pro-inflammatory cytokines and chemokines. Untargeted metabolomics followed by bioinformatics and integrative omics were used to profile the levels of metabolites in the CSF. Human motor neurons (hMNs) were differentiated from induced pluripotent stem cells (iPSCs) and infected with the highly pathogenic TBEV-Hypr strain to profile the role(s) of identified metabolites during the virus lifecycle. Virus infection was quantified via plaque assay.
RESULTS: Significant differences in proinflammatory cytokines (IFN-α2, TSLP, IL-1α, IL-1β, GM-CSF, IL-12p40, IL-15, and IL-18) and chemokines (IL-8, CCL20, and CXCL11) were detected between neurological-TBEV and control patients. A total of 32 CSF metabolites differed in TBE patients with meningitis and encephalitis. CSF S-Adenosylmethionine (SAM), Fructose 1,6-bisphosphate (FBP1) and Phosphoenolpyruvic acid (PEP) levels were 2.4-fold (range ≥ 2.3-≥3.2) higher in encephalitis patients compared to the meningitis group. CSF urocanic acid levels were significantly lower in patients with encephalitis compared to those with meningitis (p = 0.012209). Follow-up analyses showed fluctuations in the levels of O-phosphoethanolamine, succinic acid, and L-proline in the encephalitis group, and pyruvic acid in the meningitis group. TBEV-infection of hMNs increased the production of SAM, FBP1 and PEP in a time-dependent manner. Depletion of the metabolites with characterised pharmacological inhibitors led to a concentration-dependent attenuation of virus growth, validating the identified changes as key mediators of TBEV infection.
CONCLUSIONS: Our findings reveal that the neurological disease outcome of TBEV infection is associated with specific and dynamic metabolic signatures in the cerebrospinal fluid. We describe a new in vitro model for in-depth studies of TBEV-induced neuropathogenesis, in which the depletion of identified metabolites limits virus infection. Collectively, this reveals new biomarkers that can differentiate and predict TBEV-associated neurological disease. Additionally, we have identified novel therapeutic targets with the potential to significantly improve patient outcomes and deepen our understanding of TBEV pathogenesis.

Keywords: Cerebrospinal fluid; Chemokines; Human motor neurons; Metabolomics; Neuroinflammation; Pro-inflammatory cytokines; Tick-borne encephalitis virus

DOI: https://doi.org/10.1186/s12974-025-03478-4

Poult Sci. 2025 Jun 10. pii: S0032-5791(25)00665-0. [Epub ahead of print]104(9): 105421

Genome-wide CRISPR/Cas9 screen identifies host factors for Newcastle disease virus replication.

Jianxia Tian, Ying Wang, Zijie Zhou, Yuzhen Li, Chuanyu Chang, Fanxing Meng, Weiwei Shi, Hanlue Li, Weifan Wang, Qiaolin Wei, Haijin Liu, Zengqi Yang, Sa Xiao.

Viruses rely strictly on host factors to determine their susceptibility. Newcastle disease virus (NDV), an avian pathogen, can infect a wide range of avian, mammalian and human cell lines. However, NDV can only infect certain mammals and humans, and it does not cause disease in mammals or mice. A comprehensive identification of NDV-susceptible host genes that promote NDV infection is lacking. Here, we performed a mouse genome-wide CRISPR knockout (GeCKO) screening in murine fibroblast L929 cells infected with NDV. Fifty host genes were highly enriched in the screening. Using a viral minigenome assay and gene overexpression as well as single guide RNA (sgRNA) knockout, one of the genes was shown to predominantly promote viral replication. This gene is the solute carrier family 35 member A1 (SLC35A1), which is a cytidine monophosphate (CMP)-Sia transporter involved in the synthesis of sialic acid (SA). Knockout of SLC35A1 in L929 cells decreased the expression of the NDV receptors α2,3-SA and α2,6-SA on the cell surface, resulting in significant reductions in viral adsorption, internalization and replication. Furthermore, the knockout of a six-residue stretch, 82LGSPKE87, of SLC35A1 in cells specifically reduced the expression of the α2,6-SA receptor but not the α2,3-SA receptor, which decreased viral adsorption and replication. The reconstitution of SLC35A1 in the knockout cells completely recovered the α2,3-SA receptor, partially recovered the α2,6-SA receptor and almost completely recovered viral replication. In chicken fibroblast DF-1 cells, siRNA-mediated knockdown of chicken SLC35A1 reduced the expression levels of both the α2,6-SA and α2,3-SA receptors, decreasing viral replication. Our research indicated that SLC35A1 is a key host factor that promotes NDV replication. The CRISPR/Cas9 system can be used to identify essential host factors for the replication of intracellular pathogens. This study provides valuable insights into host susceptibility to NDV.

Keywords: GeCKO; Newcastle disease virus; SLC35A1; Sialic acids

DOI: https://doi.org/10.1016/j.psj.2025.105421

Signal Transduct Target Ther. 2025 Jun 15. 10(1): 191

Purine nucleoside phosphorylase dominates Influenza A virus replication and host hyperinflammation through purine salvage.

Influenza A virus (IAV) poses a significant threat to human health. The outcome of IAV results from the viral-host interaction, with the underlying molecular mechanisms largely unknown. By integrating the plasma proteomics data of the IAV-infected patients into the viral-inflammation protein-protein interaction (VI-PPI) network created in this study, purine nucleoside phosphorylase (PNP), the critical enzyme in purine salvage, was identified as a potential hub gene that connected the different stages of IAV infection. Extended survival rates and reduced pulmonary inflammatory lesions were observed in alveolar epithelial cell (AEC)-specific PNP conditional knockout mice upon H1N1 infection. Mechanistically, PB1-F2 of IAV was revealed as a novel viral transcriptional factor to bind to the TATA box of PNP promoter, leading to enhanced purine salvage in H1N1-challenged AECs. The activation of PNP-mediated purine salvage was verified in IAV-infected patients and A549 cells. PNP knockdown elicited a purine metabolic shift from augmented salvage pathway to de novo synthesis, constraining both viral infection and pro-inflammatory signaling through APRT-AICAR-AMPK activation. Moreover, durdihydroartemisinin (DHA), predicted by VI-PPI as a novel PNP inhibitor, exerted beneficial effects on the survival and weight gain of H1N1-challenged mice via its direct binding to PNP. To reveal for the first time, we found that PNP, activated by IAV, plays a hub role within H1N1-host interaction, simultaneously modulating viral replication and hyperinflammation through purine salvage. Our study sheds new light on a "two-for-one" strategy by targeting purine salvage in combating IAV-related pathology, suggesting PNP as a potential novel anti-influenza host target.

DOI: https://doi.org/10.1038/s41392-025-02272-1

Emerg Microbes Infect. 2025 Jun 19. 2522877

Monkeypox Virus Induces Ferroptosis to Facilitate Viral Replication and Promotes Inflammatory Responses.

Xia Chuai, Yuping Wang, Chen Wang, Tianxi Ye, Xiaofan Shen, Jinge Zhou, Kaiyue Zhang, Baoxin Zhao, Yan Wu, Wujian Li, Zhigang Cai, Sandra Chiu.

Ferroptosis is an iron-dependent form of programmed cell death, which is characterized by iron overload and accumulation of lipid peroxidation. As a newly identified type of cell death, its involvement in poxvirus infection and pathogenesis remains unclear. Since MPXV shares biological and pathogenic similarities with other poxviruses, such as vaccinia virus (VACV), we used VACV-infected cell and mouse models to demonstrate that VACV infection induces ferroptosis both in vitro and in vivo. Inhibition of ferroptosis significantly reduce virus replication and alleviates the inflammatory response. Additionally, we observed that VACV infection upregulates prostaglandin-endoperoxide synthase 2 (PTGS2), which contributes to virus-triggered ferroptosis and inflammation. This study identifies a novel form of cell death triggered by poxvirus infection, shedding light on host-pathogen interactions and offering a potential therapeutic target for MPXV and other Orthopoxviruses.

Keywords: PTGS2; ferroptosis; inflammatory responses; virus replication; ：MPXV

DOI: https://doi.org/10.1080/22221751.2025.2522877

Cell Mol Life Sci. 2025 Jun 19. 82(1): 241

Hypoxia-inducible factor 2 triggers the production of highly infectious native-like hepatitis C virus particles.

Mathilde Couteaudier, Mona Nivard, Jade Cochard, Fabrizio Mammano, Philippe Roingeard, Hugues de Rocquigny, Philippe Chouteau.

We recently developed an original HCV-permissive cell culture model based on both partial differentiation and physiological oxygen pressure (Hypo-Diff cells) that produces highly infectious lipid-rich and native-like HCV-lipoviroparticles (LVPs). Here, we explored the precise role of physiological hypoxia and related specific transcription factors, hypoxia-inducible factors 1α and 2α (HIF-1α and HIF-2α) to better understand the mechanism governing viral morphogenesis. Knocking-down HIF-2α specifically reduced both the number and size of neutral lipid-rich droplets in Huh7.5 Hypo-Diff cells, suggesting a central role for HIF-2 in controlling lipid metabolism under physiological hypoxia. In HCV-infected siHIF-2α Hypo-Diff cells, both HCV replication and the specific infectious viral efficacy of progeny viruses were significantly impaired. Interestingly, the ectopic expression of a mutated form of the HIF-2α protein, stabilized in normoxia, both increased the number and size of neutral lipid-rich droplets and restored the production of highly infectious HCV viruses in the absence of cell differentiation. Finally, by iodixanol fractionation of supernatants to determine the mean buoyant density of infectious HCV LVPs, we established that HIF-2α is exclusively responsible for producing highly lipidated and broadly infectious HCV-LVPs by Hypo-Diff cells. These findings thus clearly establish the central role of physiological hypoxia, and notably HIF-2, in the production of highly infectious lipid-rich native-like HCV particles. Since physiological hypoxia is a shared characteristic in mammalian tissues, we propose to reconsider the role of natural oxygen tension and especially the role of HIF-2 in the life cycle of other lipid-associated viruses, whether hepatotropic or not.

Keywords: Cell culture model; HCV; HIF-2; Hypoxia; Lipid droplets; Morphogenesis and infectivity

DOI: https://doi.org/10.1007/s00018-025-05739-0