Journal of General Virology最新文献

{"title":"ICTV Virus Taxonomy Profile: <i>Adnaviria</i> 2025.","authors":"Mart Krupovic, Fengbin Wang, Virginija Cvirkaite-Krupovic, Jens H Kuhn, Valerian V Dolja, David Prangishvili, Edward H Egelman, Eugene V Koonin","doi":"10.1099/jgv.0.002091","DOIUrl":"10.1099/jgv.0.002091","url":null,"abstract":"<p><p>Viruses assigned to the realm <i>Adnaviria</i> have linear, dsDNA genomes in which the DNA is structured in the A-form rather than the usual B-form. Virions are flexible or rigid filaments, with or without envelopes. Adnavirians share homologous major capsid proteins (MCPs) with a distinct <i>α</i>-helical structural fold not observed in other known viruses. The MCPs form homodimeric or heterodimeric capsomers that wrap around and condense the genomic dsDNA into helically symmetrical virions. Adnavirians infect hyperthermophilic, thermoacidophilic and methanotrophic archaea. This is a summary of the International Committee on Taxonomy of Viruses Report on the realm <i>Adnaviria</i>, which is available at ictv.global/report/adnaviria.</p>","PeriodicalId":15880,"journal":{"name":"Journal of General Virology","volume":"106 3","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143730323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>Bacilladnaviridae</i>: refined taxonomy and new insights into the biology and evolution of diatom-infecting DNA viruses.","authors":"Arvind Varsani, Joy M Custer, Ilaria N Cobb, Ciara Harding, Courtney L Collins, Crystal Suazo, Joshua Schreck, Rafaela S Fontenele, Daisy Stainton, Anisha Dayaram, Sharyn Goldstein, Darius Kazlauskas, Simona Kraberger, Mart Krupovic","doi":"10.1099/jgv.0.002084","DOIUrl":"10.1099/jgv.0.002084","url":null,"abstract":"<p><p>Bacilladnaviruses are single-stranded DNA viruses that infect diatoms that, so far, have been primarily identified in marine organisms and environments. Using a viral metagenomics approach, we discovered 13 novel bacilladnaviruses originating from samples of mud-flat snail (<i>Amphibola crenata</i>; <i>n</i>=3 genomes) and benthic sediments (<i>n</i>=10 genomes) collected from the Avon-Heathcote Estuary in New Zealand. Comparative genomics and phylogenetic analysis of the new bacilladnavirus sequences in the context of the previously classified members of the family helped refine and further expand the <i>Bacilladnaviridae</i> taxonomy. Here, based on the replication-associated protein phylogeny and pairwise identities, we established 4 new genera - <i>Aberdnavirus</i>, <i>Keisodnavirus</i>, <i>Puahadnavirus</i> and <i>Seawadnavirus</i> - and 13 new species within the family. Comparison of the bacilladnavirus capsid protein sequences suggests that the positively charged N-terminal region (R-arm) is required for encapsidation of the larger genomes, whereas the smaller bacilladnavirus genomes can be packaged in the absence of the R-arm subdomain. Furthermore, analysis of the bacilladnavirus genomes revealed that members of three genera encode a highly derived variant of a phospholipase A1, which is predicted to be involved in the lysis of the infected diatoms and/or facilitates the entry of the virions into the host cells. Collectively, our results allow refining of the taxonomy of bacilladnaviruses and provide new insights into the biology and evolution of this understudied group of diatom viruses.</p>","PeriodicalId":15880,"journal":{"name":"Journal of General Virology","volume":"106 3","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11903649/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143615646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterisation of the virome of <i>Culicoides brevitarsis</i> Kieffer (Diptera: Ceratopogonidae)<i>,</i> a vector of bluetongue virus in Australia.","authors":"Stephen R Sharpe, Mukund Madhav, Melissa J Klein, Kim R Blasdell, Prasad N Paradkar, Stacey E Lynch, Debbie Eagles, Adam J López-Denman, Khandaker Asif Ahmed","doi":"10.1099/jgv.0.002076","DOIUrl":"10.1099/jgv.0.002076","url":null,"abstract":"<p><p><i>Culicoides</i> spp., a common biting midge genus, are haematophagous insects that can transmit pathogens to humans and other animals. Some species transmit arboviruses, including bluetongue virus, epizootic haemorrhagic disease virus, African horse sickness virus and Schmallenberg virus to vertebrates, which can be detrimental to livestock and wild animals. <i>Culicoides</i> spp. can also have a diversity of insect-specific viruses (ISVs) that can only be transmitted between insects and others related to known arboviruses. For <i>Culicoides brevitarsis</i> and other <i>Culicoides</i> spp. in Australia, the virome is largely unexplored. We used high-throughput sequencing to characterise the virome of <i>C. brevitarsis</i> collected from Casino, New South Wales, Australia. For virus detection, the total RNA was extracted from pools of <i>C. brevitarsis</i> followed by rRNA depletion and Illumina short-read-based RNA sequencing. The reads were quality-checked, filtered and assembled into contigs, compared with the non-redundant protein and conserved domain databases for viral detection and genome organisation, respectively. The phylogenetic analysis was used to further characterise the viruses. We detected new virus diversity including ten viruses belonging to eight different families with complete or near-complete coding regions. Seven of these were novel virus species belonging to the families: <i>Chuviridae</i>, <i>Orthomyxoviridae</i>, <i>Peribunyaviridae</i>, <i>Qinviridae</i>, <i>Rhabdoviridae</i> and <i>Solemoviridae</i>. In addition, the novel <i>Peribunyaviridae</i> virus should also be considered part of a new genus. Whilst most of the detected viruses grouped into families with viruses that can infect insects, animals or both, the novel species of <i>Solemoviridae</i> was closely related to an economically important plant pathogen, the sugarcane yellow leaf virus. Our quantitative PCR-based screening confirmed the absence of any <i>Wolbachia</i> endosymbiont within the collected samples. Furthermore, we detected fragments of three more virus families known to infect fungi and plants. The detection of potential arboviruses and ISVs in <i>Culicoides</i> spp. is important in understanding virus epidemiology.</p>","PeriodicalId":15880,"journal":{"name":"Journal of General Virology","volume":"106 2","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11842880/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143458242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Utility of hypervariable region in hepatitis E virus for genetic evolution analysis and epidemiological studies.","authors":"Dong-Hwi Kim, Da-Yoon Kim, Jae-Hyeong Kim, Kyu-Beom Lim, Andrew Y Cho, Joong-Bok Lee, Seung-Yong Park, Chang-Seon Song, Sang-Won Lee, Dong-Hun Lee, Do-Geun Kim, In-Soo Choi","doi":"10.1099/jgv.0.002080","DOIUrl":"10.1099/jgv.0.002080","url":null,"abstract":"<p><p>Clinical and experimental studies have advanced our understanding of hepatitis E virus (HEV) infection; however, translating the findings to improve prevention and clinical outcomes remains challenging. Phylogenetic analyses of HEV show inconsistencies due to variations in the nucleotide regions studied. This study examined specific HEV regions to facilitate comprehensive molecular and phylogenetic analyses by examining the complete genome and commonly studied partial genome regions. We compared topological similarities between phylogenetic trees and evaluated evolutionary divergence using base substitutions and pairwise distances. The hypervariable region (HVR) showed the closest topology (Robinson-Foulds, Jaccard Robinson-Foulds and clustering information) to the complete genome and a higher mutation rate, resulting in longer branch lengths and clearer genotypic distinctions. Pairwise analysis revealed greater intra- and intergenotypic diversity in the HVR than in other regions. The higher base substitution rate and longer branch lengths of HVR suggest its key role in genotype evolution. Classifying HEV using HVR instead of the other partial genomic regions can reveal subtypes that more accurately reflect the genetic characteristics of HEV. Future research could focus on HVRs to better compare clinical symptoms and genetic features of HEV.</p>","PeriodicalId":15880,"journal":{"name":"Journal of General Virology","volume":"106 2","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143399299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genomic analysis reveals low genetic diversity and no continuous reintroduction of piscine myocarditis virus in farmed Atlantic salmon in the Faroe Islands.","authors":"Maria Marjunardóttir Dahl, Petra Elisabeth Petersen, Debes Hammershaimb Christiansen","doi":"10.1099/jgv.0.002068","DOIUrl":"10.1099/jgv.0.002068","url":null,"abstract":"<p><p>Piscine myocarditis virus (PMCV) is the causative agent of cardiomyopathy syndrome (CMS), a significant disease in farmed Atlantic salmon (<i>Salmo salar</i> L.). Although an increasing number of CMS outbreaks have been recorded in the Faroe Islands since the reemergence of CMS in 2013, overall PMCV genetic diversity, transmission pathways and evolutionary trajectories remain elusive. Here, we present a fast amplicon-based whole-genome sequencing method of PMCV directly from field samples and disclose 48 novel genomes, adding to the single genome currently available. Phylogenetic analysis revealed that genomes with a broad spatiotemporal representation of Faroese farmed salmon formed a homogenous monophyletic cluster compared to Norwegian and Irish PMCV genomes. Homogeneity of the Faroese genomes was substantiated with principal component analyses, where no spatiotemporal clustering of genotypes was found, nor any clustering based on roe or smolt origin. One genome from a returning wild salmon differed considerably from all the rest and formed an outgroup. All three ORFs exhibited signs of purifying selection, although ORF3 displayed a comparatively lower degree of selective constraint. Furthermore, no virulence-determining amino acid substitutions were identified in the Faroese genomes as no association was found between CMS cases and specific amino acid substitutions or motifs. Our data suggest that PMCV was introduced into the Faroe Islands from Norway, where brood fish is known to be infected. However, despite a steadily increasing import of Norwegian roe, our results show no continuous reintroduction of persisting PMCV strains to Faroese farmed salmon.</p>","PeriodicalId":15880,"journal":{"name":"Journal of General Virology","volume":"106 2","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11822202/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143399296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prohibitin of swine antagonizes SADS-CoV replication and virus-induced apoptosis.","authors":"Jingya Xu, Cheng Li, Tuoxin Huang, Ling Zhou, Xiaoya Zhao, Yuan Sun, Jingyun Ma","doi":"10.1099/jgv.0.002073","DOIUrl":"10.1099/jgv.0.002073","url":null,"abstract":"<p><p>Swine acute diarrhoea syndrome coronavirus (SADS-CoV) is an enveloped, single-stranded positive-sense RNA virus that causes acute diarrhoea and death in piglets, resulting in significant economic losses to the pig farming industry. Studying the interaction patterns between SADS-CoV and host proteins can provide guidance for the development of antiviral drugs. In previous work, we identified 289 host proteins interacting with the SADS-CoV M protein through glutathione S-transferase pull down combined with LC-MS/MS. Here, we focus on prohibitin (PHB), which is associated with the stability of mitochondrial function in cells, and demonstrate that there is a physical interaction and cellular co-localization relationship between the SADS-CoV M protein and PHB protein. Additionally, SADS-CoV-mediated infection has a strong correlation with PHB expression, and regulating PHB expression dose-dependently antagonizes SADS-CoV replication. Moreover, we discovered that PHB has an antagonistic effect on apoptosis induced by SADS-CoV infection. Overall, this work helps to elucidate the role of the PHB protein in the SADS-CoV life cycle, providing a potential target for antiviral research.</p>","PeriodicalId":15880,"journal":{"name":"Journal of General Virology","volume":"106 2","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143391076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Examining the feasibility of replacing ORF3a with fluorescent genes to construct SARS-CoV-2 reporter viruses.","authors":"Isobel Webb, Maximillian Erdmann, Rachel Milligan, Megan Savage, David A Matthews, Andrew D Davidson","doi":"10.1099/jgv.0.002072","DOIUrl":"10.1099/jgv.0.002072","url":null,"abstract":"<p><p>The SARS-CoV-2 genome encodes at least nine accessory proteins, including innate immune antagonist and putative viroporin ORF3a. ORF3a plays a role in many stages of the viral replication cycle, including immune modulation. We constructed two recombinant (r)SARS-CoV-2 viruses in which the ORF3a gene was replaced with mScarlet (mS) or mNeonGreen (mNG), denoted as rSARS-CoV-2-Δ3a-mS and rSARS-CoV-2-Δ3a-mNG, respectively. rSARS-CoV-2-Δ3a-mNG generated a fluorescent signal after infection in both A549-ACE-2-TMPRSS2 (AAT) and Vero-E6-TMPRSS2 (VTN) cells, unlike rSARS-CoV-2-Δ3a-mS. rSARS-CoV-2-Δ3a-mS mS protein could be detected immunologically in VTN but not AAT cells, indicating the expression of a non-fluorescent mS protein. The analysis of the viral transcriptomes in infected AAT cells by nanopore direct RNA sequencing (dRNAseq) revealed that the level of mS transcript was below the limit of detection in AAT cells. rSARS-CoV-2-Δ3a-mNG virus was found to be genetically stable in AAT and VTN cells, but rSARS-CoV-2-Δ3a-mS acquired partial deletions of the mS gene during sequential passaging in VTN cells, creating the virus rSARS-CoV-2-Δ3a-ΔmS. The mS deletion in VTN cells removes the chromophore coding sequence, and this may explain the presence of a non-fluorescent mS protein detected in VTN cells. The rSARS-CoV-2-Δ3a-mNG, rSARS-CoV-2-Δ3a-mS and rSARS-CoV-2-Δ3a-ΔmS viruses all replicated to a lower titre and produced smaller plaques than the parental rSARS-CoV-2-S-D614G. Interestingly, the rSARS-CoV-2-Δ3a-ΔmS virus produced higher virus titres and larger plaque sizes than rSARS-CoV-2-Δ3a-mS. This suggested that both the insertion of mS coding sequence and the deletion of ORF3a coding sequence contributed to attenuation. In comparison with rSARS-CoV-2, the rSARS-CoV-2-Δ3a-mS and rSARS-CoV-2-Δ3a-mNG viruses showed increased sensitivity to pre-treatment of cells with IFN-α but did not exhibit a dose-dependent increase in replication in the presence of the Janus kinase-signal transducer and activator of transcription signalling pathway inhibitor, ruxolitinib. In conclusion, the replacement of the ORF3a coding sequence with those of fluorescent reporter proteins attenuated the replication of SARS-CoV-2 and its ability to effectively evade the innate immune response <i>in vitro</i>.</p>","PeriodicalId":15880,"journal":{"name":"Journal of General Virology","volume":"106 2","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11822206/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143399294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Targeting pseudoknots with Cas13b inhibits porcine epidemic diarrhoea virus replication.","authors":"Hee-Jeong Han, Daseuli Yu, Jeonghye Yu, Jihye Kim, Won Do Heo, Dongseob Tark, Sang-Min Kang","doi":"10.1099/jgv.0.002071","DOIUrl":"10.1099/jgv.0.002071","url":null,"abstract":"<p><p>Clustered regularly interspaced short palindromic repeats-associated protein 13 (CRISPR-Cas13), an RNA editing technology, has shown potential in combating RNA viruses by degrading viral RNA within mammalian cells. In this study, we demonstrate the effective inhibition of porcine epidemic diarrhoea virus (PEDV) replication and spread using CRISPR-Cas13. We analysed the sequence similarity of the pseudoknot region between PEDV and severe acute respiratory syndrome coronavirus 2, both belonging to the <i>Coronaviridae</i> family, as well as the similarity of the RNA-dependent RNA polymerase (RdRp) gene region among three different strains of the PED virus. Based on this analysis, we synthesized three CRISPR RNAs (crRNAs) targeting the pseudoknot region and the nonpseudoknot region, each for comparison. In cells treated with crRNA #3 targeting the pseudoknot region, <i>RdRp</i> gene expression decreased by 95%, membrane (<i>M</i>) gene expression by 89% and infectious PEDV titre within the cells reduced by over 95%. Additionally, PED viral nucleocapsid (<i>N</i>) and M protein expression levels decreased by 83 and 98%, respectively. The optimal concentration for high antiviral efficacy without cytotoxicity was determined. Treating cells with 1.5 µg of Cas13b mRNA and 0.5 µg of crRNA resulted in no cytotoxicity while achieving over 95% inhibition of PEDV replication. The Cas13b mRNA therapeutics approach was validated as significantly more effective through a comparative study with merafloxacin, a drug targeting the pseudoknot region of the viral genome. Our results indicate that the pseudoknot region plays a crucial role in the degradation of the PEDV genome through the CRISPR-Cas13 system. Therefore, targeting Cas13b to the pseudoknot offers a promising new approach for treating coronavirus infections.</p>","PeriodicalId":15880,"journal":{"name":"Journal of General Virology","volume":"106 2","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11793167/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143189395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative syncytia formation dynamics of coronavirus MHV-A59 and pneumovirus hRSV A2 and incorporation into improved kinetic virus replication models.","authors":"Emily H Landwehr, Lyla R Vivian, George G Papadeas, Ethan J White, Jayden M Doster, Nicholas R Brenner, Kara M Selesky, Cora A Zilinski, Angelena M Donovan, Stefania M Farha, Lindsay Lewellyn, Dia C Beachboard, Scott Kaschner, Christopher C Stobart","doi":"10.1099/jgv.0.002078","DOIUrl":"10.1099/jgv.0.002078","url":null,"abstract":"<p><p>Replication models have been developed to describe the replication dynamics of a variety of viruses to better understand the kinetics and key contributing factors affecting infectivity and spread. However, accurate representations of the dynamics of virus replication observed <i>in vitro</i> and <i>in vivo</i> are often limited due to the failure of these models to account for both environmental influences, such as temperature, and the variety of possible mechanisms employed by viruses to spread. Several major families of viruses including paramyxoviruses, pneumoviruses and coronaviruses, induce and use the formation of syncytia, large multinucleated cell masses formed through fusion of cells, to aid in spread to neighbouring susceptible cells. In this study, we evaluate and compare both the dynamics and roles of temperature and syncytia formation on the replication of two different fusogenic viruses <i>in vitro</i>: human respiratory syncytial virus (hRSV) and a murine coronavirus, mouse hepatitis virus (MHV). Thermal stability, replication kinetics and both the rates and dynamics of syncytia formation were evaluated for hRSV and MHV. These data were then incorporated into a novel and improved replication model for each of the two viruses, which provides new insights into the contributions of both temperature and syncytia formation in the replication of fusogenic viruses.</p>","PeriodicalId":15880,"journal":{"name":"Journal of General Virology","volume":"106 2","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143408486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The EMCV protein 2B* is required for efficient cell lysis via both caspase-3-dependent and -independent pathways during infection.","authors":"Samantha K Nguyen, Edward Long, James R Edgar, Andrew E Firth, Hazel Stewart","doi":"10.1099/jgv.0.002075","DOIUrl":"10.1099/jgv.0.002075","url":null,"abstract":"<p><p>2B* is a poorly characterized protein encoded by an overlapping ORF in the genome of encephalomyocarditis virus (EMCV). We have previously found 2B* to have a role in innate immune antagonism; however, this role is distinct from an earlier described phenotype whereby 2B*KO viruses exhibit extremely small plaques compared to WT. Here, we report that the small plaque phenotype is recapitulated by novel EMCV mutant viruses harbouring mutations across the C-terminal domain of 2B*, confirming a functional role of 2B* in promoting viral spread. We found that 2B*KO EMCV displays impaired extracellular virus titres compared to WT EMCV, despite producing a similar number of infectious particles overall. This correlates with a reduction in cell lysis and lower levels of caspase-3 cleavage occurring during infection. Further investigation using caspase inhibitors and knockout cells revealed that WT EMCV can utilize both caspase-3-dependent and caspase-3-independent pathways to achieve cell lysis, the former of which is likely to be GSDME-mediated pyroptosis. 2B* increases the efficiency of both lytic pathways through an as-yet-undefined mechanism. This work reveals 2B*, a protein only found in EMCV, to be a key regulator of multiple lytic cell death pathways, leading to enhanced rates of virus release. This explains the rapid cell death observed during WT EMCV infection and the small plaque phenotype seen in both 2B*KO and previously described 2B* mutant viruses.</p>","PeriodicalId":15880,"journal":{"name":"Journal of General Virology","volume":"106 2","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11811419/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143391077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}