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"Meng, Chunchun"
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Inhibition of anti-viral stress granule formation by coronavirus endoribonuclease nsp15 ensures efficient virus replication
2021
Cytoplasmic stress granules (SGs) are generally triggered by stress-induced translation arrest for storing mRNAs. Recently, it has been shown that SGs exert anti-viral functions due to their involvement in protein synthesis shut off and recruitment of innate immune signaling intermediates. The largest RNA viruses, coronaviruses, impose great threat to public safety and animal health; however, the significance of SGs in coronavirus infection is largely unknown. Infectious Bronchitis Virus (IBV) is the first identified coronavirus in 1930s and has been prevalent in poultry farm for many years. In this study, we provided evidence that IBV overcomes the host antiviral response by inhibiting SGs formation via the virus-encoded endoribonuclease nsp15. By immunofluorescence analysis, we observed that IBV infection not only did not trigger SGs formation in approximately 80% of the infected cells, but also impaired the formation of SGs triggered by heat shock, sodium arsenite, or NaCl stimuli. We further demonstrated that the intrinsic endoribonuclease activity of nsp15 was responsible for the interference of SGs formation. In fact, nsp15-defective recombinant IBV (rIBV-nsp15-H238A) greatly induced the formation of SGs, along with accumulation of dsRNA and activation of PKR, whereas wild type IBV failed to do so. Consequently, infection with rIBV-nsp15-H238A strongly triggered transcription of IFN-β which in turn greatly affected rIBV-nsp15-H238A replication. Further analysis showed that SGs function as an antiviral hub, as demonstrated by the attenuated IRF3-IFN response and increased production of IBV in SG-defective cells. Additional evidence includes the aggregation of pattern recognition receptors (PRRs) and signaling intermediates to the IBV-induced SGs. Collectively, our data demonstrate that the endoribonuclease nsp15 of IBV interferes with the formation of antiviral hub SGs by regulating the accumulation of viral dsRNA and by antagonizing the activation of PKR, eventually ensuring productive virus replication. We further demonstrated that nsp15s from PEDV, TGEV, SARS-CoV, and SARS-CoV-2 harbor the conserved function to interfere with the formation of chemically-induced SGs. Thus, we speculate that coronaviruses employ similar nsp15-mediated mechanisms to antagonize the host anti-viral SGs formation to ensure efficient virus replication.
Journal Article
Unlocking the secrets of Feline calicivirus: advances in structural and nonstructural proteins and its role as a key model for other Caliciviruses
2025
Feline calicivirus
(FCV) is a highly contagious pathogen responsible for respiratory infections, lingual ulceration, oral ulcers and systemic diseases in cats, posing a significant risk to feline family worldwide. Virus enters via nasal oral and conjunctival routes. Oropharynx is primary site of replication, induces epithelial necrosis. After recovery from acute disease most cats clear virus within 30 days. Some lifelong carriers via colonization of tonsillar and other tissues. Understanding the structural and nonstructural proteins of FCV is essential to know viral replication process, its pathogenesis and interaction with host immune system. This manuscript outlines the recent progress made on the characterization of FCV proteins with respect to their involvement in viral assembly, entry, immune evasion, and replication. Although structural proteins such as capsid have received most attention regarding viral attachment and host specificity, but nonstructural proteins are emerging as key players in influencing host cell activities and viral RNA synthesis. This review highlights the requirement for advanced structural research methods, large-scale antiviral screening, and thorough investigations into FCV-host interactions. These studies will not only enable us fully understand FCV, but also promote the progress of more universally applicable virological research and drug development.
Graphical abstract
Journal Article
Newcastle Disease virus infection activates PI3K/Akt/mTOR and p38 MAPK/Mnk1 pathways to benefit viral mRNA translation via interaction of the viral NP protein and host eIF4E
by
Song, Cuiping
,
Liu, Weiwei
,
Yu, Shengqing
in
1-Phosphatidylinositol 3-kinase
,
AKT protein
,
Antibodies
2020
Newcastle disease virus (NDV), a member of the Paramyxoviridae family, can activate PKR/eIF2α signaling cascade to shutoff host and facilitate viral mRNA translation during infection, however, the mechanism remains unclear. In this study, we revealed that NDV infection up-regulated host cap-dependent translation machinery by activating PI3K/Akt/mTOR and p38 MAPK/Mnk1 pathways. In addition, NDV infection induced p38 MAPK/Mnk1 signaling participated 4E-BP1 hyperphosphorylation for efficient viral protein synthesis when mTOR signaling is inhibited. Furthermore, NDV NP protein was found to be important for selective cap-dependent translation of viral mRNAs through binding to eIF4E during NDV infection. Taken together, NDV infection activated multiple signaling pathways for selective viral protein synthesis in infected cells, via interaction between viral NP protein and host translation machinery. Our results may help to design novel targets for therapeutic intervention against NDV infection and to understand the NDV anti-oncolytic mechanism.
Journal Article
Pathogenicity and immunogenicity of gI/gE/TK-gene-deleted Felid herpesvirus 1 variants in cats
2023
Background
Felid herpesvirus 1
(FHV-1) is a major pathogenic agent of upper respiratory tract infections and eye damage in felines worldwide. Current FHV-1 vaccines offer limited protection of short duration, and therefore, do not reduce the development of clinical signs or the latency of FHV-1.
Methods
To address these shortcomings, we constructed FHV ∆gIgE-eGFP, FHV ∆TK mCherry, and FHV ∆gIgE/TK eGFP-mCherry deletion mutants (ΔgI/gE, ΔTK, and ΔgIgE/TK, respectively) using the clustered regularly interspaced palindromic repeats (CRISPR)/CRISP-associated protein 9 (Cas9) system (CRISPR/Cas9), which showed safety and immunogenicity in vitro. We evaluated the safety and efficacy of the deletion mutants administered with intranasal (IN) and IN + subcutaneous (SC) vaccination protocols. Cats in the vaccination group were vaccinated twice at a 4-week interval, and all cats were challenged with infection 3 weeks after the last vaccination. The cats were assessed for clinical signs, nasal shedding, and virus-neutralizing antibodies (VN), and with postmortem histological testing.
Results
Vaccination with the gI/gE-deleted and gI/gE/TK-deleted mutants was safe and resulted in significantly lower clinical disease scores, fewer pathological changes, and less nasal virus shedding after infection. All three mutants induced virus-neutralizing antibodies after immunization.
Conclusions
In conclusion, this study demonstrates the advantages of FHV-1 deletion mutants in preventing FHV-1 infection in cats.
Journal Article
Recent Advances on the Positively-Charged Nanofiltration Membranes for Mg2+/Li+ Separation Through Interfacial Polymerization
2025
The rapid development of the global energy industry has driven an escalating worldwide demand for lithium resources. As a major lithium source, salt lake brines contain abundant divalent ions that hinder efficient lithium extraction. Compared with conventional lithium recovery technologies, nanofiltration membranes emerge as an energy-efficient and environmentally friendly alternative. Over the past decade, interfacial polymerization has been widely adopted to fabricate nanofiltration membranes for lithium–magnesium separation, with studies confirming the superior performance of positively charged membranes in distinguishing monovalent and divalent cations. This review systematically summarizes recent advancements in positively charged nanofiltration membranes synthesized via interfacial polymerization for lithium–magnesium separation, categorizing the design strategies into five distinct approaches. The correlations between intrinsic membrane structural characteristics and separation performance are critically analyzed. Furthermore, current challenges and future research directions are discussed to provide new perspectives for developing high-performance positively charged composite nanofiltration membranes. This work aims to inspire innovative designs and accelerate the practical implementation of nanofiltration technology in lithium extraction from salt lake brines.
Journal Article
ATM-mediated DNA double-strand break response facilitated oncolytic Newcastle disease virus replication and promoted syncytium formation in tumor cells
by
Song, Cuiping
,
Yang, Zengqi
,
Sun, Yingjie
in
A549 Cells
,
Acid Anhydride Hydrolases - genetics
,
Acid Anhydride Hydrolases - metabolism
2020
Deoxyribonucleic acid (DNA) damage response (DDR) is the fundamental cellular response for maintaining genomic integrity and suppressing tumorigenesis. The activation of ataxia telangiectasia-mutated (ATM) kinase is central to DNA double-strand break (DSB) for maintaining host-genome integrity in mammalian cells. Oncolytic Newcastle disease virus (NDV) can selectively replicate in tumor cells; however, its influence on the genome integrity of tumor cells is not well-elucidated. Here, we found that membrane fusion and NDV infection triggered DSBs in tumor cells. The late replication and membrane fusion of NDV mechanistically activated the ATM-mediated DSB pathway via the ATM-Chk2 axis, as evidenced by the hallmarks of DSBs, i.e., auto-phosphorylated ATM and phosphorylated H2AX and Chk2. Immunofluorescence data showed that multifaceted ATM-controlled phosphorylation markedly induced the formation of pan-nuclear punctum foci in response to NDV infection and F-HN co-expression. Specific drug-inhibitory experiments on ATM kinase activity further suggested that ATM-mediated DSBs facilitated NDV replication and membrane fusion. We confirmed that the Mre11-RAD50-NBS1 (MRN) complex sensed the DSB signal activation triggered by NDV infection and membrane fusion. The pharmacological inhibition of MRN activity also significantly inhibited intracellular and extracellular NDV replication and syncytia formation. Collectively, these data identified for the first time a direct link between the membrane fusion induced by virus infection and DDR pathways, thereby providing new insights into the efficient replication of oncolytic NDV in tumor cells.
Journal Article
Evaluating the Reconstructed All-Weather Land Surface Temperature for Urban Heat Island Analysis
2024
With the continuous improvement of urbanization levels in the Lhasa area, the urban heat island effect (UHI) has seriously affected the ecological environment of the region. However, the satellite-based thermal infrared land surface temperature (LST), commonly used for UHI research, is affected by cloudy weather, resulting in a lack of continuous spatial and temporal information. In this study, focusing on the Lhasa region, we combine simulated LST data obtained by the Weather Research and Forecasting (WRF) model with remote sensing-based LST data to reconstruct the all-weather LST for March, June, September, and December of 2020 at a resolution of 0.01° while using the Moderate-Resolution Imaging Spectroradiometer (MODIS) LST as a reference (in terms of accuracy). Subsequently, based on the reconstructed LST, an analysis of the UHI was conducted to obtain the spatiotemporal distribution of UHI in the Lhasa region under all-weather LST conditions. The results demonstrate that the reconstructed LST effectively captures the expected spatial distribution characteristics with high accuracy, with an average root mean square error of 2.20 K, an average mean absolute error of 1.51 K, and a correlation coefficient consistently higher than 0.9. Additionally, the heat island effect in the Lhasa region is primarily observed during the spring and winter seasons, with the heat island intensity remaining relatively stable in winter. The results of this study provide a new reference method for the reconstruction of all-weather LST, thereby improving the research accuracy of urban thermal environment from the perspective of foundational data. Additionally, it offers a theoretical basis for the governance of UHI in the Lhasa region.
Journal Article
A novel feline herpesvirus vector subunit FCV VP1 and FPV VP2 vaccine protects cats against FHV-1 and FPV challenge and induces serum neutralizing antibody responses against FCV
2025
Vaccines targeting feline parvovirus (FPV), feline calicivirus (FCV), and feline herpesvirus type 1 (FHV-1) are considered core vaccines and are widely recommended for feline immunoprophylaxis. Currently, trivalent feline vaccines used in clinical settings are primarily based on inactivated or modified live attenuated formulations. Among these pathogens, FHV-1 has demonstrated notable potential as a viral vector due to its large genome and immunogenic profile, making it an attractive platform for multivalent vaccine development. In this study, we developed a novel trivalent live attenuated vaccine candidate by engineering FHV-1 as a viral vector to co-express immunogenic proteins from FPV and FCV. Using homologous recombination and CRISPR/Cas9-mediated genome editing, we constructed the recombinant strain FHV ΔgI/gE/TK-FCV VP1-FPV VP2, which expresses FCV VP1 and FPV VP2. Expression of these proteins was confirmed by Western blot and immunofluorescence assay (IFA), and the recombinant virus remained genetically stable during in vitro passaging. Immunization with this construct induced robust virus-neutralizing antibody responses and conferred protective immunity against both FHV-1 and FPV. These findings underscore the feasibility of using FHV-1 as a multivalent viral vector and provide a promising foundation for next-generation feline vaccines.
Journal Article
Assessments of future climate extremes in China by using high-resolution PRECIS 2.0 simulations
2021
Based on bias-corrected future projections from the Providing REgional Climates for Impacts Studies (PRECIS) regional climate model under both RCP4.5 and 8.5 scenarios over China, extreme climatic events at the middle and end of the twenty-first century are investigated in this paper. The model performance of PRECIS is validated using comparisons with observations and HadGEM2-ES projections, and the bias correction adds fidelity to the projections of basic climate variables and extreme climate events. In the future, our single-realisation estimates show that the number of frost days is projected to decrease and days with tropical nights are projected to increase. Including northeast China, Sichuan Basin, middle and lower reaches of Yangtze River and south China, the number of consecutive dry days will increase from our single-realisation estimates, which will exhibit a spatial distribution almost similar to that of consecutive wet days in the coming decades. Although precipitation indices associated with duration will increase, a simple precipitation index depicting the intensity of extreme events will decrease over east and south China in the future from our single-realisation projections. Daily rainfall above 50 mm, which is usually regarded as a rainstorm event, is predicted to increase under the RCP4.5 scenario over most of China from our single-realisation estimates; while the same change pattern will occur in southernmost China, similarly spatially distributed for the RCP8.5 scenario, the number of rainstorm will first increase in the middle of the twenty-first century and then slow at the end of the twenty-first century in the Yangtze River region. In conclusion, our single-realisation estimates indicate that the persistence of extreme precipitation will increase with time, but the change of extreme precipitation intensity is not significant in the future. The comparison of climatic extreme events under the RCP4.5 scenario with those under the RCP8.5 scenario shows that extreme climate events will be enhanced under the higher emissions scenario; hence, reductions in greenhouse gas emissions will help alleviate climate change effects in the future.
Journal Article
Development of a TaqMan One-Step Quantitative PCR Assay for the Simultaneous Detection of Novel Goose Parvovirus and Novel Duck Reovirus
2025
The novel goose parvovirus (NGPV) and the novel duck reovirus (NDRV) are pathogens that can substantially affect the growth and development of ducklings, causing considerable economic losses to duck farms. Therefore, a timely, rapid, accurate, and high-throughput diagnosis and identification of viral infections are critical for preventing the spread of epidemics. In this study, a TaqMan probe-based duplex one-step RT-qPCR was established for the simultaneous detection and qualitative and quantitative identification of the two viruses. It demonstrated greater sensitivity than conventional PCR, detecting as low as 2.42 copies/μL of NGPV genome and 70.1 copies/μL of NDRV genome. Additionally, it exhibited remarkable specificity, responding exclusively to the nucleic acids of target pathogens. It also demonstrated excellent reproducibility and availability, particularly in clinical settings, with a coinfection detection rate of 13.3%, contributing to the development of NGPV- and NDRV-testing technologies.
Journal Article