Journal of Virology最新文献

{"title":"Monotherapy with antibody 1C3 partially protects Ebola virus-exposed macaques.","authors":"Gabriella Worwa, Carl W Davis, Sarah E Klim, Jacquelyn Turcinovic, Krystle N Agans, Viktoriya Borisevich, Joan B Geisbert, Robert W Cross, Anya Crane, Michael R Holbrook, Mariano Sanchez-Lockhart, Jeffrey R Kugelman, Juan A Patino Galindo, Thomas W Geisbert, Rafi Ahmed, Jens H Kuhn, Erica Ollmann Saphire, Gustavo Palacios, Ian Crozier","doi":"10.1128/jvi.00296-25","DOIUrl":"https://doi.org/10.1128/jvi.00296-25","url":null,"abstract":"<p><p>A cocktail of human monoclonal antibodies 1C3 and 1C11 previously protected macaques from a lethal exposure to either Ebola virus (EBOV) or Sudan virus (SUDV). 1C3 is of particular interest because its paratope strongly binds with unique stoichiometry to the glycoprotein head of several orthoebolaviruses, resulting in neutralization of EBOV and SUDV. Therefore, we evaluated the protective activity of 1C3 as a standalone therapeutic in macaques exposed to either EBOV or SUDV. Two doses of 1C3 monotherapy, administered 4 and 7 days post-exposure, did not protect SUDV-exposed macaques and partially protected EBOV-exposed macaques. Notably, in a macaque that succumbed to EBOV infection, we identified two mutually exclusive escape mutations that emerged immediately after the first dose and resulted in two amino acid changes at the 1C3 binding site. We also detected a subconsensus treatment-emergent mutation likely affecting the 1C3 binding site in all three deceased SUDV-exposed macaques. Our findings highlight combination treatment with 1C11 as critical for protection, particularly against SUDV, and <i>in vivo</i> activity of unpartnered 1C3 as susceptible to rapid EBOV and SUDV escape under therapeutic pressure.</p><p><strong>Importance: </strong>A cocktail of human monoclonal antibodies 1C3 and 1C11 previously protected macaques exposed to a lethal dose of either Ebola virus (EBOV) or Sudan virus (SUDV). Since the unique binding characteristics of 1C3 are of particular interest, we evaluated its protective activity as monotherapy in macaques exposed to either EBOV or SUDV. Two doses of 1C3 alone did not protect SUDV-exposed macaques and only partially protected EBOV-exposed macaques. Importantly, failure to protect was associated with the rapid emergence of previously <i>in vitro</i>-identified escape mutations at the 1C3 binding site, highlighting the importance of its use in combination with 1C11 for protection against fatal disease outcome and avoiding rapid EBOV and SUDV escape. Findings have broader implications for the wise use of combination-based monoclonal antibody therapeutics to improve outcomes and prevent resistance in filovirid diseases.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0029625"},"PeriodicalIF":4.0,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144258371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Immunogenicity of NSDV GP38 and the role of furin in GP38 proteolytic processing.","authors":"Caroline Bost, Filipe Tomaz, Luna C Schmacke, Sven Reiche, Nabil G Seidah, Torsten Steinmetzer, Martin H Groschup, Axel Karger, Sandra Diederich, Kerstin Fischer","doi":"10.1128/jvi.00537-25","DOIUrl":"https://doi.org/10.1128/jvi.00537-25","url":null,"abstract":"<p><p>Nairobi sheep disease virus (NSDV) is a tick-borne orthonairovirus, which is genetically related to Crimean-Congo hemorrhagic fever virus (CCHFV), and causes severe hemorrhagic gastroenteritis in infected sheep. CCHFV GP38, a cleavage product of the CCHFV glycoprotein precursor (GPC), has recently attracted attention: not only has GP38 been reported to elicit detectable anti-GP38 antibodies in CCHFV-infected patients, but anti-GP38 antibodies have also been shown to protect mice from lethal CCHFV challenge. While proteolytic cleavage of CCHFV GP38 has been described to involve the proprotein convertases furin and subtilisin/kexin-isozyme-1 (SKI-1), little is known about the processing of NSDV GPC, or the occurrence and immunogenicity of NSDV GP38 in infected sheep. Here, we provide the first evidence for the presence and immunogenicity of NSDV GP38 in infected sheep demonstrating seroconversion by the detection of anti-GP38 antibodies over the course of infection. To further characterize GPC processing <i>in vitro</i>, we investigated the impact of furin overexpression and the effect of a furin inhibitor on NSDV glycoprotein expression, cleavage, and viral infectivity. While virus infectivity remained unaffected, our results suggest that other proteases besides furin may play a role in the proteolytic processing of NSDV GPC at a cleavage site that remains to be explored. Taken together, our findings highlight the immunogenicity of NSDV GP38 in sheep and warrant further research into the similarities and differences in proteolytic cleavage between the glycoproteins of NSDV and other orthonairoviruses, such as CCHFV.</p><p><strong>Importance: </strong>Nairobi sheep disease virus (NSDV) is a zoonotic orthonairovirus causing severe and often fatal hemorrhagic gastroenteritis in small ruminants. Its genetic relationship to human-pathogenic Crimean-Congo hemorrhagic fever virus (CCHFV) and striking similarities in the clinical picture between CCHFV-infected patients and NSDV-infected ruminants have led to the idea that NSDV could serve as a model organism to study CCHFV pathogenesis. However, knowledge on NSDV-host interactions has been limited. While CCHFV GP38 has recently attracted attention as vaccine candidate and possible virulence factor, the occurrence and role of putative GP38 in other orthonairoviruses has been unclear. This study provides first evidence for the presence and immunogenicity of NSDV GP38 in infected sheep. Furthermore, our data indicate that other proteases besides furin may be involved in the proteolytic cleavage of NSDV GPC. Future studies are needed to determine the proteases involved and to investigate the possible functional role of GP38 in NSDV pathogenesis.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0053725"},"PeriodicalIF":4.0,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144258370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The furin cleavage site is required for pathogenesis, but not transmission, of SARS-CoV-2.","authors":"Angelica L Morgan, Michelle N Vu, Yiyang Zhou, Kumari G Lokugamage, William M Meyers, R Elias Alvarado, Yani Ahearn, Leah K Estes, Jessica A Plante, Bryan A Johnson, Mehul S Suthar, David H Walker, Ken S Plante, Vineet D Menachery","doi":"10.1128/jvi.00467-25","DOIUrl":"10.1128/jvi.00467-25","url":null,"abstract":"<p><p>The SARS-CoV-2 spike, key to viral entry, has two features that differentiate it from other sarbecoviruses: the presence of a furin cleavage site (FCS; PRRAR sequence) and an extended S1/S2 loop characterized by an upstream QTQTN amino acid motif. Our prior works show that shortening the S1/S2 loop by deleting either the FCS (ΔPRRA) or an upstream sequence (ΔQTQTN) ablates spike processing, alters host protease usage, and attenuates infection <i>in vitro</i> and <i>in vivo</i>. With the importance of the loop length established, we evaluated the impact of disrupting the FCS while preserving the S1/S2 loop length. Using reverse genetics, we generated a SARS-CoV-2 mutant that disrupts the FCS (PQQAR) but maintains its extended S1/S2 loop. The SARS-CoV-2 PQQAR mutant has reduced replication, decreased spike processing, and attenuated disease <i>in vivo</i> compared to wild-type SARS-CoV-2. These data, similar to those from the FCS deletion mutant, indicate that loss of the furin cleavage site attenuates SARS-CoV-2 pathogenesis. Importantly, we subsequently found that the PQQAR mutant can be transmitted in the direct contact hamster model despite lacking an intact FCS. However, competition transmission showed that the mutant was attenuated compared to WT SARS-CoV-2. Together, the data suggest that the FCS is required for SARS-CoV-2 pathogenesis but is not strictly required for viral transmission.</p><p><strong>Importance: </strong>The presence of the furin cleavage site (FCS) within the spike protein of SARS-CoV-2 distinguishes it from other sarbecoviruses found in nature. While prior works have deleted the FCS, these mutant viruses also shortened the S1/S2 loop, which is known to be important for pathogenesis. This study defines the importance of the FCS in the context of the extended SARS-CoV-2 S1/S2 loop. The study finds that the FCS disruption mutant is attenuated <i>in vitro</i> and <i>in vivo</i>. Disruption of the FCS reduces spike processing and changes the usage of the host protease TMPRSS2. Importantly, while not strictly required, the FCS plays a role in SARS-CoV-2 transmission efficiency. Overall, the manuscript demonstrates the importance of the furin cleavage site for SARS-CoV-2 infection, pathogenesis, and transmission.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0046725"},"PeriodicalIF":4.0,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144258372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-term serial passaging of SARS-CoV-2 reveals signatures of convergent evolution.","authors":"Charles S P Foster, Gregory J Walker, Tyra Jean, Maureen Wong, Levent Brassil, Sonia R Isaacs, Yonghui Lyu, Stuart Turville, Anthony Kelleher, William D Rawlinson","doi":"10.1128/jvi.00363-25","DOIUrl":"https://doi.org/10.1128/jvi.00363-25","url":null,"abstract":"<p><p>Understanding viral evolutionary dynamics is crucial to pandemic responses, prediction of virus adaptation over time, and virus surveillance for public health strategies. Whole-genome sequencing (WGS) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has enabled fine-grained studies of virus evolution in the human population. Serial passaging <i>in vitro</i> offers a complementary controlled environment to investigate the emergence and persistence of genetic variants that may confer selective advantage. In this study, nine virus lineages, including four \"variants of concern\" and three former \"variants under investigation,\" were sampled over ≥33 serial passages (range 33-100) in Vero E6 cells. WGS was used to examine virus evolutionary dynamics and identify key mutations with implications for fitness and/or transmissibility. Viruses accumulated mutations regularly during serial passaging. Many low-frequency variants were lost, but others became fixed, suggesting either <i>in vitro</i> benefits or at least a lack of deleterious effect. Mutations arose convergently both across passage lines and when compared with contemporaneous SARS-CoV-2 clinical sequences. These mutations included some that are hypothesized to drive lineage success through host immune evasion (e.g., S:A67V, S:H655Y). The appearance of these mutations <i>in vitro</i> suggested key mutations can arise convergently even in the absence of a multicellular host immune response through mechanisms other than immune-driven mutation. Such mutations may provide other benefits to the viruses <i>in vitro</i>, or arise stochastically. Our quantitative investigation into SARS-CoV-2 evolutionary dynamics spans the greatest number of serial passages to date and will inform measures to reduce the effects of SARS-CoV-2 infection on the human population.IMPORTANCEThe ongoing evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains a challenge for long-term public health efforts to minimize the effects of coronavirus disease 2019. Whole-genome sequencing of outbreak cases has enabled global contact tracing efforts and the identification of mutations of concern within the virus' genome. However, complementary approaches are necessary to inform our understanding of virus evolution and clinical outcomes. Here, we charted the evolution of the virus within a controlled cell culture environment, focusing on nine different virus lineages. Our approach demonstrates how SARS-CoV-2 continues to evolve readily <i>in vitro</i>, with changes mirroring those seen in outbreak cases globally. Findings of the study are important for (i) investigating the mechanisms of how mutations arise, (ii) predicting the future evolutionary trajectory of SARS-CoV-2, and (iii) informing treatment and prevention design.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0036325"},"PeriodicalIF":4.0,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144248528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kaposi's sarcoma-associated herpesvirus ORF61 protein sequesters APOBEC3B in filamentous aggregates.","authors":"Laura-Marie Luoto, Enrico Caragliano, Carola Schneider, Rudolph Reimer, Wolfram Brune","doi":"10.1128/jvi.00789-25","DOIUrl":"https://doi.org/10.1128/jvi.00789-25","url":null,"abstract":"<p><p>Herpesviruses are large DNA viruses that encode homologs of cellular enzymes. The viral ribonucleotide reductase, which consists of large R1 and small R2 subunits, is required for deoxyribonucleotide synthesis. However, herpesviruses have repurposed the R1 subunit for additional non-canonical functions in virus-host interaction and immune evasion. Here, we investigated the R1 proteins of Kaposi's sarcoma-associated herpesvirus (KSHV) and murine gammaherpesvirus 68 (MHV-68), two γ-herpesviruses of the genus <i>Rhadinovirus</i>. We show that the ORF61-encoded viral R1 proteins form elongated cytoplasmic condensates in infected cells, which structurally differ from the previously described R1 condensates of other herpesviruses. Fluorescently labeled ORF61 condensates exhibited the properties of solid aggregates, as determined by fluorescence recovery after photobleaching (FRAP). Correlative light and electron microscopy (CLEM) showed that ORF61 aggregates consist of filamentous bundles. The KSHV ORF61 protein interacted with the cellular cytosine deaminase APOBEC3B in infected cells and translocated it from the nucleus, the site of viral DNA replication, to the cytoplasmic aggregates. Aggregate formation and relocalization of APOBEC3B depended on a conserved Induced Protein Aggregation Motif (IPAM) in the C-terminal part of ORF61. A KSHV ORF61 IPAM mutant was vulnerable to APOBEC3B-mediated deamination and replicated to reduced titers. In contrast, MHV-68 ORF61 did not relocalize human or murine APOBEC3 proteins, suggesting that it engages different target proteins. The results show that rhadinovirus ORF61 proteins form elongated filamentous aggregates in infected cells to sequester and inactivate target proteins, such as APOBEC3B.IMPORTANCEHerpesviruses are large DNA viruses that encode enzymes similar to those in host cells. The R1 subunit of their ribonucleotide reductase is important for DNA synthesis and plays additional roles in immune evasion and virus-host interactions. This study focused on the R1 protein ORF61 of two γ-herpesviruses of the genus <i>Rhadinovirus</i>: KSHV and MHV-68. Unlike their homologs in other herpesviruses, KSHV and MHV-68 R1 proteins form cytoplasmic aggregates consisting of filamentous bundles in infected cells. KSHV ORF61 depletes the mutagenic cellular enzyme APOBEC3B from the nucleus, the site of viral DNA replication, and sequesters it in cytoplasmic aggregates, thereby protecting the viral genome from APOBEC3B-mediated mutations. This process relies on a specific conserved motif in ORF61. However, the MHV-68 ORF61 protein does not redistribute APOBEC3 proteins, suggesting that it binds different targets. These findings reveal how rhadinoviruses use filamentous ORF61 aggregates to manipulate host antiviral defenses.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0078925"},"PeriodicalIF":4.0,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144225798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inherited chromosomally integrated human herpesvirus 6: regional variation in prevalence, association with angina, and identification of ancestral viral lineages in two large UK studies.","authors":"Michael L Wood, Adam J Bell, Robin Young, Christopher Brownlie, Nick Orr, Archie Campbell, Jenna Nichols, Konstantinos Papageorgiou, Annette Lake, Nicolas M Suarez, Katherine Smollett, Natasha Jesudason, Salvatore Camiolo, Sreenu Vattipally, Joseph Hughes, Kirby Brown, Leah M Hunter, Euan Shaw, Skye Storrie, Rithu Paul Stansilaus, Eillis Sweeney, Tingyi Zhu, Angie Fawkes, Lee Murphy, William Tyne, Philip Howard, Michael E Jones, Katarzyna Tomczyk, Anne Richmond, James F Wilson, Duncan A Clark, Christian Delles, Nicola Royle, Shona M Kerr, Ana da Silva Filipe, Andrew J Davison, Alex McConnachie, Anthony J Swerdlow, Caroline Hayward, Ruth F Jarrett","doi":"10.1128/jvi.02160-24","DOIUrl":"https://doi.org/10.1128/jvi.02160-24","url":null,"abstract":"<p><p>Tens of millions of people worldwide have inherited chromosomally integrated human herpesvirus 6 (iciHHV-6), yet we know little about the consequences. iciHHV-6-positive individuals inherit the genome of HHV-6A or HHV-6B in the germline, and viral genomes are therefore present in every nucleated cell. To investigate the epidemiology of iciHHV-6 in the UK, almost 32,000 individuals were screened from two volunteer research studies: the family-based Generation Scotland: Scottish Family Health Study (GS:SFHS) and the Breakthrough Generations Study (BGS). iciHHV-6 prevalence in GS:SFHS was, to our knowledge, higher than that in other large studies at 2.74% (647/23,637), with an iciHHV-6B prevalence of 2.55%. Scottish participants were more likely to be iciHHV-6B-positive than English (<i>P</i> < 0.001), and the BGS results suggested a north-south gradient of iciHHV-6B prevalence in mainland Britain. Disease association analysis confirmed the previously reported association with angina, with an odds ratio of 1.91 (95% confidence interval, 1.29, 2.82) following adjustment for known risk factors, providing compelling evidence that iciHHV-6 contributes to the risk of a common symptom. <i>De novo</i> integrations were not detected within GS:SFHS pedigrees; rather, our findings indicated that three viral lineages accounted for over 95% of iciHHV-6A-positive samples, and six viral lineages accounted for 90% of iciHHV-6B-positive samples in GS:SFHS. This study demonstrates that iciHHV-6 is common in the UK, shows significant regional heterogeneity in prevalence, is not entirely harmless, and is largely derived from a relatively small number of ancestral viral lineages.IMPORTANCEHuman herpesvirus 6 (HHV-6) has the unusual ability to integrate into the host chromosome telomeres. Most of the world's population is infected by HHV-6 in early childhood, but around 1% inherit the virus as a chromosomally integrated viral genome-referred to as inherited chromosomally integrated HHV-6 (iciHHV-6). Little is known about the consequences of iciHHV-6, which has the potential to cause disease through various mechanisms. Here, we have used large cohorts to study iciHHV-6 prevalence, lineages, and phenotypic associations. We replicate a previously reported association between iciHHV-6 and angina, suggesting that iciHHV-6 is not entirely benign. We show significant variation in iciHHV-6 prevalence within the UK with almost 3% of Scottish people carrying iciHHV-6. In the first detailed analysis of viral lineages at the population level, we show that 90% of iciHHV-6 is explained by nine ancestral viral lineages. These results have important implications for future disease association analyses.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0216024"},"PeriodicalIF":4.0,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144225797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid reconstruction of infectious bronchitis virus expressing fluorescent protein from its nsp2 gene based on transformation-associated recombination platform.","authors":"Yingfei Li, Linqing Duan, Lihua Tang, Min Huang, Ye Zhao, Guozhong Zhang, Jing Zhao","doi":"10.1128/jvi.00535-25","DOIUrl":"https://doi.org/10.1128/jvi.00535-25","url":null,"abstract":"<p><p>Traditional reverse genetics strategies for large-genome RNA viruses are hindered by multiple technical bottlenecks, including dependence on specific restriction enzyme sites, cumbersome multi-step cloning, and genetic instability of oversized DNA in bacterial systems. Herein, we established a universal reverse genetics platform for infectious bronchitis virus (IBV) through systematic optimization of the transformation-associated recombination (TAR) technology. By dividing the IBV genome into seven overlapping fragments and employing <i>Saccharomyces cerevisiae</i> for seamless assembly, we obtained a stable full-length genome clone with an efficiency exceeding 95%. Optimizing cultivation temperature and selecting appropriate <i>Escherichia coli</i> strains were key improvements that minimized mutagenesis during bacterial replication, ensuring fidelity of the constructs. The rescued QX-type IBV strain replicated and induced pathogenicity in chicken embryos comparably to clinical isolates, while retaining engineered markers without additional mutations. The platform's feasibility was further confirmed by successfully rescuing the Mass-type IBV strain, demonstrating its broad applicability. Notably, we pioneeringly rescued a reporter virus expressing the mNeonGreen fluorescent protein, linked via the porcine teschovirus 1 2A proteolytic cleavage site, immediately upstream of the IBV nsp2 gene. This design enabled autonomous separation of the reporter from viral polyproteins without the deletion of any viral gene. The recombinant virus stably maintained this insertion for at least 10 passages, marking the nsp2 site as a flexible locus for foreign gene accommodation in IBV. This study not only establishes a universal TAR-based reverse genetics platform for gamma-coronaviruses but also provides a powerful tool for visualization-based high-throughput antiviral drug screening.</p><p><strong>Importance: </strong>Traditional reverse genetics systems for infectious bronchitis virus (IBV) are often hindered by assembly difficulties <i>in vitro</i> and viral genome instability during bacterial propagation. Here, we developed a transformation-associated recombination-based platform for seamless IBV genome assembly and rapid virus rescue within 12 days. Additionally, we identified a novel foreign gene insertion site between the 5' UTR and nsp2 in the viral genome, enabling stable fluorescent protein expression without deleting any viral genes, ensuring that virus replication is not affected. This system provides a powerful tool for tracking IBV infection, studying viral tropism, and screening antivirals, thereby advancing coronavirus research and poultry disease control.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0053525"},"PeriodicalIF":4.0,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144225799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heat shock protein 90 chaperone activity is required for hepatitis A virus replication.","authors":"You Li, Xin Zheng, Ling Xie, Maryna Kapustina, Takayoshi Shirasaki, Bryan Yonish, Xian Chen, Asuka Hirai-Yuki, Noriyo Nagata, Ryosuke Suzuki, Masanori Isogawa, Matthew R Vogt, Masamichi Muramatsu, Stanley M Lemon","doi":"10.1128/jvi.00502-25","DOIUrl":"https://doi.org/10.1128/jvi.00502-25","url":null,"abstract":"<p><p>HSP90 heat shock chaperones are essential for maintaining cellular proteostasis, as well as the ATP-dependent folding and functional maturation of many viral proteins. As a result, inhibitors of HSP90 have broad antiviral activity, disrupting replication of many viruses at concentrations below those causing cytotoxicity. Among the <i>Picornaviridae</i>, HSP90 inhibitors block replication of multiple <i>Enterovirus</i>, <i>Aphthovirus,</i> and <i>Cardiovirus</i> species, in some cases, by preventing post-translational processing and assembly of P1 capsid proteins. Hepatitis A virus (HAV), classified within the genus <i>Hepatovirus</i>, has been suggested to be an exception among picornaviruses and to replicate independently of HSP90, possibly because its slow translational kinetics could facilitate co-translational folding and assembly of its capsid proteins. However, we show here that HAV replication is highly dependent upon HSP90, both in human hepatocyte-derived cell lines, in which the 50% inhibitory concentration of geldanamycin was 8.7-11.8 nM, and <i>in vivo</i> in <i>Ifnar1^-/-</i> mice. Label-free proteomics experiments suggested that HSP90 interacts with capsid proteins or their precursors and may thus facilitate the folding and assembly of capsid proteins, as it does for enteroviruses and aphthoviruses. By contrast, there was no evidence for HSP90 interacting with any nonstructural protein, and HSP90 inhibitors did not impair 3C^pro proteolytic activity. Despite this, and in contrast to previous studies of enteroviruses and aphthoviruses, geldanamycin potently inhibited replication of a subgenomic HAV replicon. We conclude that HAV is no exception from the HSP90-dependent nature of other picornaviruses and indeed is more dependent on HSP90 than other picornaviruses for amplification of its genome.IMPORTANCEHepatitis A virus (HAV), a common cause of acute infectious hepatitis, has been reported to differ from other picornaviruses in not requiring heat shock protein HSP90 for efficient replication. However, we show here that productive HAV infection is highly dependent on HSP90 and that HAV replication is potently blocked both in cell culture and <i>in vivo</i> in the murine liver by chemical inhibitors of HSP90. Such inhibitors also disrupt the replication of a subgenomic HAV RNA replicon, indicating that HSP90 is required for the assembly of functional replication organelles. This highlights a key difference from other picornaviruses for which HSP90 is required primarily, if not exclusively, for the maturation of the P1 capsid proteins.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0050225"},"PeriodicalIF":4.0,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144225796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trim7 does not have a role in the restriction of murine norovirus infection <i>in vivo</i>.","authors":"Mridula Annaswamy Srinivas, Linley R Pierce, Mikayla C Olson, Shelly J Roberston, Gail L Sturdevant, Sonja M Best, Robert C Orchard","doi":"10.1128/jvi.00816-25","DOIUrl":"10.1128/jvi.00816-25","url":null,"abstract":"<p><p>Trim7 is an E3 ubiquitin ligase that was recently identified as a central regulator of host-viral interactions with both pro-viral and anti-viral activity in cell culture. As an inhibitor, Trim7 overexpression ubiquitinates viral proteins by recognizing C-terminal glutamines that are hallmarks of 3C-like protease cleavage events. Here, we sought to determine the physiological impact of Trim7 in resolving murine norovirus (MNV) infection of mice, as MNV is potently inhibited by Trim7 <i>in vitro</i>. Utilizing two independently derived Trim7-deficient mouse lines, we found no changes in the viral burden or tissue distribution of MNV in both an acute and persistent model of infection. Additionally, no changes in cytokine responses were observed after acute MNV infection of Trim7-deficient mice. Furthermore, removal of potentially confounding innate immune responses such as STING and STAT1 did not reveal any role for Trim7 in regulating MNV replication. Taken together, our data fail to find a physiological role for Trim7 in regulating MNV infection outcomes in mice and serve as a caution for defining Trim7 as a broad-acting antiviral.IMPORTANCEIntrinsic antiviral molecules that restrict viral replication are important drivers of viral evolution and viral tropism. Recently, Trim7 was shown to provide cell-intrinsic protection against RNA viruses, including murine norovirus. Biochemically, Trim7 recognizes the cleavage product of viral proteases, suggesting a novel and broad mechanism to restrict viral replication. Here, we tested whether Trim7 had a physiological role in restricting murine norovirus replication in mice. Unexpectedly, we found no impact of viral replication or innate immune responses during murine norovirus infection. Our findings urge caution in defining Trim7 as a broad antiviral factor in the absence of <i>in vivo</i> evidence.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0081625"},"PeriodicalIF":4.0,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144216284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A group of segmented viruses contains genome segments sharing homology with multiple viral taxa.","authors":"Huang Huang, Zhongmei Zhang, Xidan Pang, Qing Tang, Xueqiong Xiao, Jiasen Cheng, Yanping Fu, Yang Lin, Tao Chen, Bo Li, Lei Zhang, Daohong Jiang, Jiatao Xie","doi":"10.1128/jvi.00332-25","DOIUrl":"https://doi.org/10.1128/jvi.00332-25","url":null,"abstract":"<p><p>The discovery of diverse segmented RNA viruses through metatranscriptomics has enabled researchers to trace their evolutionary trajectories. However, this effort has been hindered by the limited availability of complete genome sequences and the low similarity of novel viral segments. In this study, we characterized Fusarium asiaticum vivivirus 1 (FaVvV1), a +ssRNA mycovirus with 10 monocistronic RNA segments (S1 to S10, encoding VP1 to VP10), present in the phytopathogenic fungus <i>Fusarium asiaticum</i>. VP1 and VP2 exhibit homology with replication proteins of martellivirals, while VP3 and VP5 share similarities with the nuclear inclusion protein a and the cylindrical inclusion helicase of potyvirids, respectively. FaVvV1 forms rod-shaped virions, with VP8 functioning as a structural protein resembling the helical capsid of potyvirids and closterovirids. To explore the conservation and evolution of viviviruses, we mined 23 public Sequence Read Archive (SRA) datasets, identifying 29 vivivirus-related viruses (vivivirids) comprising 186 viral segments. VP1 (methyltransferase and RdRP domain), VP2 (methyltransferase and superfamily 1 helicase domain), VP3 (chymotrypsin-type serine protease domain), VP5 (superfamily 2 helicase domain), and VP8 (helical capsid) were identified as conserved hallmark proteins of viviviruses. Phylogenetic and structural analyses suggest that multiple genome segmentations and gene/domain duplications were involved in the evolution of vivivirids. VP3, VP5, and VP8 might share a common ancestor with potyvirids. These findings highlight the intricate evolutionary mechanisms underlying segmented virus diversity and adaptation.</p><p><strong>Importance: </strong>Metaviromics has greatly expanded our understanding of viral diversity, including segmented or multipartite RNA viruses with genomes composed of multiple segments. However, virome analyses often fail to detect genomic segments beyond the RdRP, likely due to their low similarity to known viruses. We characterized a group of segmented, potentially multipartite, +ssRNA viruses, with Fusarium asiaticum vivivirus 1 as a representative; most of these viruses likely infect fungi. Through structural and evolutionary analysis of the five core segments of viviviruses, our findings highlight key aspects of vivivirus evolution, including genome segmentation, gene and domain duplications, and segments with multiple evolutionary origins.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0033225"},"PeriodicalIF":4.0,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144216264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}