Journal of Virology最新文献

{"title":"Spike protein derived from an apathogenic IBV strain confers attenuated phenotype to a nephropathogenic IBV strain.","authors":"James Kirk, Samantha Sives, Adam Rayment, Amber Tappin, Sam Jones, Jessica Miles, Chandana Tennakoon, Elizabeth Martin-Drew, Graham Freimanis, Harry Francis, Thomas P Peacock, Kate Sutton, Isobel Webb, Andrew D Davidson, Paul Britton, Erica Bickerton, Sarah Keep","doi":"10.1128/jvi.01103-26","DOIUrl":"10.1128/jvi.01103-26","url":null,"abstract":"<p><p>Infectious bronchitis virus (IBV), a <i>Gammacoronavirus</i>, causes the economically damaging disease of poultry, infectious bronchitis. Development of IBV live attenuated vaccines (LAVs) is dependent on the supply of embryonated hens' eggs and attenuation through serial passaging, upwards of 80 times. Vaccine development needs to keep pace with IBV evolution; an issue compounded as cross protection between individual IBV serotypes is unpredictable and often limited. Rational attenuation alongside the ability to propagate LAVs in cell culture offers significant advantages in terms of adaptability, cost, and speed. Most field IBV strains exhibit restricted <i>in vitro</i> tropism, being unable to replicate in primary or continuous cells without serial passage and adaptation. Beaudette, an attenuated IBV strain, is capable of replication in Vero cells, an ability conferred by the spike (S) glycoprotein. In this study, utilizing a recombinant IBV based on the nephropathogenic IBV strain D388, in which the S sequence is replaced with the equivalent sequence derived from Beaudette, we determine that the Beaudette spike can confer the ability to replicate in Vero cells and Beaudette's associated attenuated <i>in vivo</i> phenotype to a distantly related IBV strain. Assessment of infectious progeny and viral RNA <i>in vivo</i> suggests that attenuation was conferred by a tissue tropism-independent molecular mechanism. Analysis of innate immune responses revealed a lower intensity and less inflammatory profile. Our findings support the use of the Beaudette S protein as an avenue for the development of rationally attenuated, cell culture-propagated rIBV vaccines and identify the S protein as a contributor to nephropathogenicity.IMPORTANCEInfectious bronchitis virus (IBV), a <i>Gammacoronavirus</i> of chickens, causes significant economic losses worldwide. Current live attenuated vaccines (LAVs) are generated through extensive serial passage of virulent IBV strains in specific-pathogen-free (SPF) embryonated hen's eggs, upwards of 80 passages. This process is slow, dependent on the availability of SPF embryonated eggs, and the molecular basis of attenuation remains poorly understood. Development of rationally attenuated, cell-culture-based IBV vaccines would enable more rapid responses to emerging viral variants/strains. Using a recombinant IBV, we demonstrated the spike glycoprotein from the attenuated IBV strain Beaudette can confer attenuation and the ability to replicate in Vero cells to a distantly related virulent IBV strain. Attenuation was not linked to changes in tissue tropism but was associated with altered host responses. Our research provides new insights into IBV pathogenesis and presents an avenue for rational attenuation that can be exploited for future development of cell-based IBV vaccines.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0110326"},"PeriodicalIF":4.1,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148920137","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 35th Annual Meeting of the Society of Virology (GfV) in Heidelberg: uniting virology research across German-speaking countries.","authors":"Ralf Bartenschlager, Christian Sieben, Stephanie Pfaender, Daniel Sauter, Sandra Ciesek, Hans-Georg Kräusslich","doi":"10.1128/jvi.01100-26","DOIUrl":"10.1128/jvi.01100-26","url":null,"abstract":"<p><p>The Society of Virology (GfV) is a non-profit association and academic society dedicated to promoting virology across all disciplines in the German-speaking countries of Austria, Germany, and Switzerland. This mission is pursued through a variety of activities, most notably its annual meeting, which provides a stimulating environment-particularly for young scientists and students-to exchange ideas, establish new collaborations, and learn from leading virologists in an informal setting. This year, the GfV held its annual meeting in the picturesque city of Heidelberg, bringing together more than 1,000 participants. The program featured five plenary sessions with distinguished speakers presenting their latest research findings. Topics included virus evolution, the cell biology of viral infection, novel approaches to studying and preventing viral infections with a focus on innovative vaccine strategies, the use of imaging technologies to investigate virus-host interactions, and the development of potent antiviral therapies for chronic viral infections, illustrated by curative therapy of chronic hepatitis C and long-term prevention of HIV-1 infection. The plenary sessions were complemented by 21 parallel workshops covering all areas of virology, as well as several satellite sessions. Many of these were organized by the Young Society of Virology (jGfV), which is dedicated to promoting the next generation of virologists. This report summarizes the presentations delivered by the plenary speakers and provides a brief overview of the activities in the various sessions, including the prize-winning contributions presented at the meeting.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0110026"},"PeriodicalIF":4.1,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149017181","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":"Regulation and function of the HPV16 CircE7 RNA.","authors":"Eunice E Lee, Yihui Huang, Eleanor Dowell, Kaitlyn Walsh, Calvin Hosler, Austin Witt, Odera Ifeacho, Doreen Palsgrove, Andrew Day, Claire James, Richard C Wang","doi":"10.1128/jvi.01284-26","DOIUrl":"10.1128/jvi.01284-26","url":null,"abstract":"<p><p>High-risk human papillomaviruses (HPV), including HPV16, produce circular RNA that encompasses the E7 oncogene (circE7). CircE7 can be detected in HPV16-positive cells and tumors, is preferentially localized to the cytoplasm, is N⁶-methyladenosine (m⁶A)-modified, and can be translated into the E7 oncoprotein. Here, we explored the regulation and function of circE7. Mutation of m⁶A motifs flanking the backsplice junction revealed a single m⁶A motif to be essential for circE7 formation. Mutation of this m⁶A motif promoted linear splicing of the E6*I splice site (226^409), suggesting that linear and circular E7 splicing are inversely regulated. Additionally, mutation of an IRES-like motif in circE7 significantly decreased E7 protein expression, without having significant effects on circE7 RNA levels. Knockdown of YTHDC1, but not other m⁶A-binding proteins, decreased both circE7 RNA and protein expression. BaseScope ISH was used to confirm the expression of circE7 in head and neck squamous cell carcinoma cell lines and tumors. Using both qRT-PCR and BaseScope ISH, we found that serum and amino acid starvation significantly increased circE7. Finally, we generated an HPV16 genome with mutations in the circE7 m⁶A motif (Mut2). Stable transduction of primary keratinocytes with Mut2 confirmed the loss of circE7 and increased expression of E6*I. The Mut2 HPV16 genome exhibited significantly decreased viral replication but an increased ability to transform primary keratinocytes. Our studies reveal that the precise regulation of circE7 and E6*I by m⁶A is critical for the ability of HPV16 to infect and transform keratinocytes.IMPORTANCEHigh-risk human papillomaviruses (HPVs), such as HPV16, must carefully control how much E6 and E7 proteins they make. This study shows that HPV16 toggles a single chemical tag on the viral RNA (an m⁶A mark) to control the production of early region RNAs, including a circular RNA called circE7. The same site coordinately regulates splicing of the E6*I isoform. CircE7 uses m⁶A-binding proteins to control its production and a specific sequence to promote its translation. It is present in HPV-positive cancers and can respond to nutrient starvation. Regulation of circE7 through this m⁶A site also impacted viral replication and transformation capacity, indicating that this regulatory mechanism is critical for HPV biology.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0128426"},"PeriodicalIF":4.1,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148990576","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":"Mutations in the macrodomain 1 of nsp3 attenuate PEDV virulence <i>in vivo</i> without impairing <i>in vitro</i> replication.","authors":"Mingde Liu, Men Thi Hoai Duong, Thamonpan Laocharoensuk, Bikash Aryal, Anthony R Fehr, Lari Lehtiö, Qiuhong Wang","doi":"10.1128/jvi.01251-26","DOIUrl":"10.1128/jvi.01251-26","url":null,"abstract":"<p><p>The conserved macrodomain 1 (Mac1) within coronavirus nsp3 reverses ADP-ribosylation of proteins and contributes to viral virulence. While Mac1 has been characterized in several coronaviruses, its role in porcine epidemic diarrhea virus (PEDV) remains unknown. Since D445 and N462 are functionally important residues in several betacoronaviruses, we mutated the two residues in both the PEDV Mac1 recombinant protein and the infectious virus and analyzed them <i>in vitro</i> and <i>in vivo</i>. Sequence alignment revealed that N462 is highly conserved, whereas D445 is less conserved among porcine coronaviruses. The N462A mutation significantly impaired both ADP-ribose binding and hydrolysis activity of Mac1, whereas D445A had minimal effect. Compared with wild-type PEDV, both PEDV mutants (icPC22A-nsp3-D445A and icPC22A-nsp3-N462A) replicated efficiently as wild type in Vero, porcine kidney LLC-PK1, and porcine intestinal epithelial IPEC-J2 cells. Unexpectedly, both mutated viruses induced significantly lower levels of interferons in LLC-PK1 cells and IPEC-J2 cells, in contrast to previously characterized Mac1 mutants of SARS-CoV-2 and MHV-JHMV strain. Moreover, the icPC22A-nsp3-N462A virus showed significantly reduced sensitivity to IFN-β treatment in Vero cells. These results suggest that the PEDV Mac1 functions as an interferon inducer. In gnotobiotic neonatal piglets, icPC22A-nsp3-N462A showed reduced and delayed peak viral shedding and attenuated phenotype compared with wild-type PEDV. Collectively, this work provides the first <i>in vitro</i> and <i>in vivo</i> evidence that the conserved N462 residue in the PEDV Mac1 domain is critical for both ADP-ribose binding and hydrolysis, induces IFN production, and contributes to virulence. However, how these pathways are connected deserves further investigation.IMPORTANCECoronaviruses frequently emerge from wildlife reservoirs to infect humans and livestock, causing economically devastating epidemics/pandemics marked by severe respiratory or enteric diseases. Despite advances in vaccines and therapies, the risk of diverse coronaviruses remains a global concern. PEDV is an alphacoronavirus and causes fatal diarrhea in neonatal pigs, leading to recurring outbreaks and significant economic losses in the global swine industry. The Mac1 domain antagonizes host ADP-ribosylation and impacts pathogenesis in beta-coronaviruses, such as SARS-CoV, SARS-CoV-2, and mouse hepatitis virus (MHV). However, its role in porcine or enteric coronaviruses remains undefined. Our study revealed that PEDV Mac1 mutations decreased enzymatic function and interferon response. The latter differs from respiratory SARS-CoV and neurotropic MHV, suggesting that Mac1's functions adapt to different host or tissue environments. Our findings identify Mac1 N462 as a rational target for live attenuated vaccine design and highlight Mac1 as a potential target for antiviral therapeutics against PEDV.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0125126"},"PeriodicalIF":4.1,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148912533","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 organization and dynamics of viral factories.","authors":"Kathryn Steele Brittain, Leonardo Martins Delfino, Otavio Henrique Thiemann, Juliana R Cortines, Kristin N Parent","doi":"10.1128/jvi.00892-26","DOIUrl":"10.1128/jvi.00892-26","url":null,"abstract":"<p><p>Viral factories (VFs) are dynamic, virus-induced microcompartments that serve as centralized hubs in the host cell for viral genome replication, transcription, and virion assembly. These structures employ unique viral mechanisms for remodeling cellular architecture to create specialized replication organelles and improve the efficiency of viral propagation. VFs exhibit striking structural and functional diversity among RNA and DNA viruses, from reoviruses and poxviruses to the <i>Nucleocytoviricota</i> phylum. Some are enclosed by host-derived membranes, while others exist as biomolecular condensates from liquid-liquid phase separation. VFs recruit host lipids, cytoskeletal elements, and metabolic enzymes, effectively reprogramming the intracellular environment to favor viral replication. This review provides a comprehensive examination of the molecular composition, ultrastructure, and biogenesis of viral factories across a wide range of viral lineages and host systems. We describe membrane-bound and phase-separated VFs and the mechanisms by which they hijack host machinery to create these replication organelles and explore viral strategies to shield replication intermediates from host immune responses. Additional emphasis is placed on the complex VFs formed by giant viruses in the <i>Nucleocytoviricota</i>, whose ability to spatially compartmentalize replication and transcription, exclude ribosomes, and recruit host mitochondria and membranes blurs the line between viral and cellular organization. By integrating findings from cell biology and evolutionary virology, this review proposes that viral factories offer a conceptual framework for understanding virus-host coevolution and provides new insights into how their organization may have shaped the emergence of eukaryotic complexity.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0089226"},"PeriodicalIF":4.1,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148963526","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":"Structure-based comparison and functional verification reveal LEF-3 as a novel core gene of baculoviruses.","authors":"Hengrui Hu, Xinyu Zhang, Xinyu Tian, Jiang Li, Zhihong Hu, Manli Wang","doi":"10.1128/jvi.00230-26","DOIUrl":"10.1128/jvi.00230-26","url":null,"abstract":"","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0023026"},"PeriodicalIF":4.1,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149075179","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":"Erratum for Steigmann et al., \"Effects of immunoproteasome inhibition on acute respiratory infection with murine hepatitis virus strain 1\".","authors":"Jacob C Steigmann, Xiaofeng Zhou, Lauren N Suttenberg, Irha Salman, Zainab F Rehmathullah, Jason B Weinberg","doi":"10.1128/jvi.01370-26","DOIUrl":"10.1128/jvi.01370-26","url":null,"abstract":"","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0137026"},"PeriodicalIF":4.1,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148968988","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":"Insights into molecular mechanisms of poxvirus evolution and host range through studies of poxvirus inhibitors of protein kinase R.","authors":"Stefan Rothenburg, Dewi Megawati, Ryan Bruneau, Loubna Tazi","doi":"10.1128/jvi.01768-24","DOIUrl":"10.1128/jvi.01768-24","url":null,"abstract":"<p><p>Protein kinase R (PKR) acts both as a sensor for virus infections, by detecting double-stranded (ds) RNA, and as an antiviral effector by phosphorylating the alpha subunit of eukaryotic translation initiation factor 2 (eIF2). Consequently, viruses have evolved many mechanisms to evade this potent antiviral protein, which in turn led to the fast evolution of PKR. There is an emerging understanding that these molecular arms races have important implications for the virulence and host range of viruses, which was in part propelled by research on PKR and poxvirus PKR inhibitors. At least four direct PKR pathway inhibitors, which either prevent PKR activation, inhibit interaction with eIF2α, or reverse eIF2α phosphorylation, evolved independently in different poxvirus clades, while poxvirus decapping enzymes provide another mechanism to subdue PKR activation via the reduction of dsRNA formation. In addition to discussing the functions and distributions of poxvirus PKR pathway inhibitors, we focus on host species-specific PKR-inhibitor interactions and their consequences for virus host range and virulence, including differential NF-κB pathway activation. We further highlight how research with PKR inhibitor-deficient poxviruses led to seminal discoveries elucidating molecular mechanisms for virus evolution, including gene amplification and horizontal gene transfer.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0176824"},"PeriodicalIF":4.1,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149039573","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":"Development of rhesus macaque enteroids and enteroid-derived cell lines for enteric calicivirus infections.","authors":"Tibor Farkas, Zeinab R Aboezz, Mafruha Marjia, Jianrong Li","doi":"10.1128/jvi.00745-26","DOIUrl":"10.1128/jvi.00745-26","url":null,"abstract":"<p><p>Recoviruses (ReCV) serve as valuable surrogates for fastidious human noroviruses (HuNoV). Although HuNoVs can be propagated in small intestinal enteroids, this system has several limitations, including low replication efficiency and an inability to sustain continuous propagation for generating infectious virus stocks beyond certain strains, such as GII.3. In contrast, ReCVs can be efficiently propagated in conventional cell lines (e.g., LLC-MK2), which has significantly advanced understanding of their biological characteristics. As a result, ReCVs are widely used as HuNoV surrogates. However, a physiologically relevant ReCV propagation system that closely mimics HuNoV enteroid cultures has not yet been described. Here, we report the establishment of intestinal stem cell-derived rhesus macaque enteroid lines representing both the small intestine and colon, along with two enteroid-derived cell lines. We further characterize these systems and evaluate their susceptibility to infection with three diverse ReCV isolates. Both small intestine- and colon-derived enteroids, as well as their corresponding cell lines, supported robust ReCV infection. The enteroids contained all major intestinal cell types. The duodenum-derived cell line comprised enteroendocrine cells (chromogranin A) and absorptive enterocytes (villin), whereas the colon-derived cell line included enteroendocrine cells and goblet cells (MUC2). Importantly, both cell lines formed tight barriers (transepithelial electrical resistance [TEER] > 3,000 Ω·cm²), making them far superior to LLC-MK2 cells (TEER ~ 100 Ω·cm²) for studies of viral entry and pathogenesis. The rhesus enteroids and intestinal cell lines developed in this study will enable comparative studies of HuNoV and ReCV replication in a physiologically relevant system and may have direct applications for culturing HuNoVs.IMPORTANCEHuman intestinal stem cell-derived enteroids have enabled the propagation of human noroviruses; however, this system has several important limitations, including high cost, low replication efficiency, and (except for a recent report for GII.3 human norovirus) the inability to sustain continuous virus propagation for the generation of infectious virus stocks. As a result, research still relies on human norovirus-containing clinical samples as the primary virus source. Here, we developed host-specific rhesus macaque enteroid cultures and two enteroid-derived cell lines that support robust recovirus replication. Studying recovirus replication in rhesus enteroids may help overcome key limitations of the human norovirus enteroid cultures. Moreover, because both natural and experimental human norovirus infections have been described in rhesus macaques, the rhesus enteroids and enteroid-derived cell lines described in this study may be directly applicable to human norovirus cultivation.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0074526"},"PeriodicalIF":4.1,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149069859","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":"DEAD-box RNA helicase 21 interacts with the nucleocapsid protein and inhibits porcine deltacoronavirus infection through upregulation of interferon responses.","authors":"Nannan Zhang, Yanyan Xu, Yanying Chen, Mingyue Ma, Wenjie Lai, Shengwei Zhong, Gaofeng Cai, Ting Wang, Bin Li, Qi Peng, Hui Jiang","doi":"10.1128/jvi.01169-26","DOIUrl":"10.1128/jvi.01169-26","url":null,"abstract":"<p><p>DEAD-box RNA helicase 21 (DDX21), a conserved RNA helicase of the DEAD-box family, serves as a key regulator of multiple fundamental cellular processes, including RNA metabolism, ribosome biogenesis, transcriptional regulation, and genomic stability. Our previous work has demonstrated an interaction between DDX21 and the nucleocapsid (N) protein of porcine deltacoronavirus (PDCoV). However, the specific role of DDX21 during PDCoV infection remains largely elusive. In the present study, we show that overexpression of DDX21 significantly restricts PDCoV infection in PK15, IPEC-J2, and HeLa cells, whereas knockout of DDX21 markedly enhances PDCoV replication in HeLa cells. Mechanistically, we identified that the N-terminal domainNTD of PDCoV N binds to the 1-217 amino acid region of DDX21, thereby inducing the cytoplasmic redistribution of DDX21 from the nucleus. Furthermore, DDX21-mediated suppression of PDCoV replication coincides with elevated interferon-β (IFN-β) production and interferon-stimulated geneISG expression. Importantly, PDCoV infection significantly downregulates DDX21 expression to antagonize its antiviral function, and similar antagonistic effects are observed for the coronaviruses from different genera. Collectively, our findings demonstrate that DDX21 interacts with the nucleocapsid protein and correlates with altered interferon signaling during coronavirus infection, which provides novel insights into the development of strategies for the prevention and control of coronavirus infections.</p><p><strong>Importance: </strong>Porcine deltacoronavirus (PDCoV) is an emerging swine coronavirus that infects pigs of all ages and causes substantial economic losses to the global swine industry. DEAD-box RNA helicase 21 (DDX21) acts as a key regulator of multiple fundamental cellular processes. However, its regulatory mechanism underlying PDCoV infection remains largely unclear. In this study, we found that DDX21 significantly inhibits PDCoV replication <i>in vitro</i>. Conversely, PDCoV infection markedly downregulates DDX21 expression. Furthermore, we demonstrated that the N-terminal 1-217 amino acid domain of DDX21 specifically interacts with the N-terminal domain (NTD) of the PDCoV nucleocapsid (N) protein. This interaction facilitates the nuclear-to-cytoplasmic translocation of DDX21, which correlates with an elevated host immune response. The upregulated interferon signature coincides with suppressed PDCoV replication. In addition, DDX21 exhibits antiviral activity against multiple coronaviruses from different genera. Collectively, this study provides novel insights into host-coronavirus interaction mechanisms and identifies a candidate target for anti-CoV therapeutic development.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0116926"},"PeriodicalIF":4.1,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149081311","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}