Journal of Virology最新文献

{"title":"Correction for Lv et al., \"Differential antigenic imprinting effects between influenza H1N1 hemagglutinin and neuraminidase in a mouse model\".","authors":"Huibin Lv, Qi Wen Teo, Chang-Chun D Lee, Weiwen Liang, Danbi Choi, Kevin J Mao, Madison R Ardagh, Akshita B Gopal, Arjun Mehta, Matt Szlembarski, Roberto Bruzzone, Ian A Wilson, Nicholas C Wu, Chris K P Mok","doi":"10.1128/jvi.00783-25","DOIUrl":"https://doi.org/10.1128/jvi.00783-25","url":null,"abstract":"","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0078325"},"PeriodicalIF":4.0,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144275147","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":"African swine fever virus infection enhances CD14-dependent phagocytosis of porcine alveolar macrophages to promote bacterial uptake and apoptotic body-mediated viral transmission.","authors":"Fengyang Shi, Zhen Xu, Peng Gao, Yajin Qu, Xinna Ge, Yongning Zhang, Jun Han, Xin Guo, Lei Zhou, Hanchun Yang","doi":"10.1128/jvi.00690-25","DOIUrl":"https://doi.org/10.1128/jvi.00690-25","url":null,"abstract":"<p><p>African swine fever virus (ASFV) is an economically devastating pathogen that can cause fatal infections in both domestic pigs and wild boar, with monocytes and macrophages as its target cells. For macrophages, phagocytosis is a fundamental and crucial process, which is usually suppressed by the virus, impeding pathogen clearance and antigen presentation. However, it was unexpectedly found that ASFV infection enhances the phagocytic ability of primary porcine alveolar macrophages (PAMs), as evaluated using an EGFP-labeled bacterial phagocytosis model. The phagocytic processes, including cell migration, bacterial adhesion, pseudopod extension, and pattern recognition receptor (PRR) expression, in ASFV-infected PAMs were systematically investigated. In addition, the upregulated PRRs were knocked down to analyze their role in enhanced phagocytosis. CD14, a receptor of LPS and phospholipid, was identified as being upregulated by ASFV, leading to enhanced bacterial uptake. Further exploration revealed that ASFV's genomic nucleic acid in infected PAMs activates the cGAS/STING/NF-κB pathway to increase CD14 expression. Meanwhile, the free ASFV nucleic acid released from infected PAMs can also activate CD14 expression in bystander PAMs via the TLR9 pathway, facilitating ASFV transmission via apoptotic bodies (ApoBDs). Moreover, the boosted bacterial phagocytosis in the early stages of ASFV infection potentially creates a more inflamed environment with more intense cytokine production. Here, it reveals a critical mechanism by which ASFV enhances CD14-dependent bacterial uptake in PAMs via the cGAS/STING/NF-κB and TLR9 pathways, promoting viral transmission through ApoBDs and amplifying inflammatory responses to bacterial co-infections, providing vital insights into ASFV pathogenesis and host immune manipulation.IMPORTANCEPorcine alveolar macrophages (PAMs) are the target cells of African swine fever virus (ASFV), but how ASFV impacts their phagocytic function is less known. Here, it was discovered that the nucleic acids of ASFV can enhance the expression of CD14, a receptor of LPS and phospholipid, in infected PAMs via the cGAS/STING/NF-κB pathway, or in bystander PAMs via the TLR9 pathway. Consequently, enhanced CD14 expression facilitates the uptake of bacteria and apoptotic bodies (ApoBDs), promoting the inflammatory response and ASFV cell-to-cell transmission. It provides new insights into the innate immunity response following ASFV infection and the transmission of ASFV.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0069025"},"PeriodicalIF":4.0,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144275231","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":"Direct pharmacological AMPK activation inhibits mucosal SARS-CoV-2 infection by reducing lipid metabolism, restoring autophagy flux and the type I IFN response.","authors":"Andrea Cottignies-Calamarte, Flora Marteau, Feifan He, Sandrine Belouzard, Jean Dubuisson, Daniela Tudor, Benoit Viollet, Morgane Bomsel","doi":"10.1128/jvi.00394-25","DOIUrl":"https://doi.org/10.1128/jvi.00394-25","url":null,"abstract":"<p><p>AMP-activated protein kinase (AMPK) plays a central role in regulating cell energy balance. When activated, AMPK suppresses energy-consuming pathways, such as lipid and protein synthesis, while increasing nutrient availability through the activation of autophagy. These pathways downstream of AMPK activation contribute to SARS-CoV-2 infection, which hijacks autophagy and accumulates lipid droplets in viral factories to support viral replication. Here, we assessed the antiviral activity of the direct pan-AMPK allosteric activator MK-8722 <i>in vitro</i>. MK-8722 efficiently inhibited infection of Alpha and Omicron SARS-CoV-2 variants in Vero76 and human bronchial epithelial Calu-3 cells at micromolar concentration. This inhibition relied on restoring the autophagic flux, which redirected newly synthesized viral proteins for degradation, and reduced lipid metabolism, which affected viral factories. Furthermore, MK-8722 treatment increased the type I interferon (IFN-I) response. Post-infection treatment with MK-8722 was enough to inhibit efficient viral replication and restore the IFN-I response. Finally, MK-8722 treatment did not alter the SARS-CoV-2-specific CD8⁺ T cell response mounted upon Spike vaccination. Overall, by activating AMPK, MK-8722 acts as an effective antiviral against SARS-CoV-2 infection, even when applied post-exposure, paving the way for preclinical tests aimed at inhibiting viral replication and improving patients' symptoms.</p><p><strong>Importance: </strong>Coronavirus disease 2019, caused by SARS-CoV-2 infection, has led to severe acute respiratory syndrome with very high mortality. Despite available vaccines and public health measures, new SARS-CoV-2 variants emerge with increased transmissibility requiring the development of novel therapeutic strategies. Recently, the AMP-activated protein kinase (AMPK), a cellular energy sensor, has emerged as a potential broad-spectrum antiviral target, as AMPK can modulate the intracellular environment in turn impeding viral replication. This study aims to evaluate the potential of pharmacological activation of AMPK to inhibit SARS-CoV-2 infection and replication. Our findings demonstrate that AMPK activation induces significant alterations in host cellular lipid metabolism that disrupt viral factories essential for SARS-CoV-2 replication. Furthermore, by enhancing autophagy, a process crucial for the degradation and clearance of viral particles, AMPK activation facilitates the elimination of the virus. Therefore, targeting AMPK signaling pathways could offer a promising therapeutic approach for the treatment of SARS-CoV-2 infections.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0039425"},"PeriodicalIF":4.0,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144275148","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":"Convergent evolution in nucleocapsid facilitated SARS-CoV-2 adaptation for human infection.","authors":"Kumari G Lokugamage, Yiyang Zhou, R Elias Alvarado, Jessica A Plante, Yani Ahearn, Jennifer Chen, Leah Estes, William Meyers, Jakob Nilsson, Andrew L Routh, David H Walker, Vineet D Menachery, Bryan A Johnson","doi":"10.1128/jvi.02091-24","DOIUrl":"https://doi.org/10.1128/jvi.02091-24","url":null,"abstract":"<p><p>During the early stages of the COVID-19 pandemic, several SARS-CoV-2 variants of concern (VOCs) independently acquired mutations in the highly variable 203-205 amino acid region of the nucleocapsid (N) protein including R203K + G204R (found in the Alpha, Gamma, and Omicron variants), R203M (in Delta), and T205I (in Beta). In previous research, we demonstrated that the R203K + G204R mutation significantly enhances SARS-CoV-2 N phosphorylation, which subsequently increases viral fitness and pathogenesis. In this study, we investigated the effects of the R203M and T205I mutations on SARS-CoV-2 infection. Using reverse genetics, we introduced these mutations into the early pandemic Washington-1 (WA-1) strain and observed that both the R203M and T205I mutants enhanced replication and viral fitness. However, unlike the R203K + G204R mutant, the R203M and T205I mutants caused only moderate changes in lung pathology. Notably, each mutation-R203K + G204R, R203M, and T205I-induced distinct patterns of N phosphorylation, which likely contribute to the observed phenotypic differences between the mutants. Interestingly, when bat cells expressing human ACE2 were infected with these mutants, we observed a reduction, rather than an enhancement, in both SARS-CoV-2 replication and N phosphorylation. Collectively, our findings suggest that the R203K + G204R, R203M, and T205I mutations are a result of convergent evolution and reflect how SARS-CoV-2 has adapted for human infection.IMPORTANCEAfter its emergence, SARS-CoV-2 rapidly adapted to human infection, acquiring numerous mutations across its genome. Many of these mutations remain uncharacterized. This study examines a mutational hotspot among SARS-CoV-2 variants: residues 203-205 of the nucleocapsid (N) protein. We demonstrate that three unique mutations identified in this region among variants of concern enhance infection in human cells and animal models while eliciting distinct patterns of N protein phosphorylation. Intriguingly, these same mutations reduce both N protein phosphorylation and viral replication in bat cells. These findings suggest that each mutation represents independent adaptation by variants of concern for human infection. Importantly, this study underscores the critical role of these mutations in facilitating the expansion of SARS-CoV-2 into human populations and highlights the potential for similar mutations to drive future zoonotic coronavirus outbreaks.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0209124"},"PeriodicalIF":4.0,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144275145","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":"High antigen burden drives CD8+ T cell dysfunction in a mouse model of chronic hepatitis B virus infection.","authors":"Catherine Rexhouse, Jacob T Bailey, Safiehkhatoon Moshkani, Jesse L Cimino, Michael D Robek","doi":"10.1128/jvi.00711-25","DOIUrl":"https://doi.org/10.1128/jvi.00711-25","url":null,"abstract":"<p><p>Chronic hepatitis B virus (HBV) infection is characterized by dysfunctional HBV-specific CD8+ T cell responses that contribute to viral persistence. Understanding the mechanisms behind this dysfunction is necessary to develop effective immunotherapies. Here, we used the adeno-associated virus (AAV)-HBV mouse model of HBV replication to investigate the development of CD8+ T cell dysfunction during chronic HBV infection. Unlike naïve mice, AAV-HBV mice with intermediate to high viral antigen levels failed to respond to therapeutic immunization against HBV antigens, indicating that failure to initially induce HBV-specific CD8+ T cell responses cannot account for the entirety of the observed CD8+ T cell dysfunction. Similarly, mice challenged with a high dose of AAV-HBV could not control antigenemia despite initially functional CD8+ T cell responses generated by immunization. These mice exhibited rapid CD8+ T cell functional impairment, marked by reduced cytokine production and increased expression of the inhibitory receptor PD-1. In contrast, mice challenged with a lower dose of AAV-HBV effectively controlled viral antigens and maintained CD8+ T cell function. Combination treatment with therapeutic immunization and antibody-mediated PD-1 and CTLA-4 blockade partially reduced HBsAg levels in mice with intermediate but not higher antigen burdens. These findings indicate that during chronic HBV infection, high antigen expression is an important factor driving a CD8+ T cell dysfunction that cannot be easily reversed and may limit the efficacy of some immunotherapeutic approaches.IMPORTANCEDespite available preventative vaccines, chronic hepatitis B virus (HBV) infection remains a major cause of liver disease worldwide, with no adequate cure. Challenges in developing effective immunotherapies include our incomplete understanding of immune dysfunction mechanisms and limited representative animal models. Here, we further characterized CD8+ T cell dysfunction mechanisms in the AAV-HBV mouse model, which shares some immunological features with human chronic HBV infection (CHB). We observed that high but not low antigen levels induced CD8+ T cell dysfunction marked by elevated PD-1 expression and led to viral persistence, despite HBsAg clearance. Additionally, responsiveness to combination immunotherapies was influenced by antigen levels at the time of treatment. This work illustrates the interplay between antigen load, immune checkpoints, and immune tolerance during CHB and may offer insights into potential strategies for enhancing HBV-specific immune responses to promote a functional cure.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0071125"},"PeriodicalIF":4.0,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144275151","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":"Engineering a recombination-resistant live attenuated vaccine candidate with suppressed interferon antagonists for PEDV.","authors":"Mingde Liu, Bikash Aryal, Xiaoyu Niu, Qiuhong Wang","doi":"10.1128/jvi.00451-25","DOIUrl":"https://doi.org/10.1128/jvi.00451-25","url":null,"abstract":"<p><p>Porcine epidemic diarrhea virus (PEDV) is a deadly coronavirus (CoV) for neonatal piglets, and no effective vaccine is available. Live attenuated vaccines (LAVs) show promise, but risks of recombination and reversion to virulence hinder their application. For LAV development, we previously engineered a recombination-resistant PEDV mutant RMT by rewiring the transcriptional regulatory sequence (TRS)-core sequences (TRS-CSs). Because TRS is critical for CoV replication, the incompatibility between wild-type TRS-CS and the rewired TRS-CS should disrupt the structural and accessory protein-encoding mRNA transcription from a recombinant PEDV genome, preventing the production of progeny infectious viruses. However, the RMT contained a 189-nt insertion upstream of the E gene TRS-CS and a missing guanine in the N gene TRS-CS. Here, we generated RMTv1 via correcting these mutations and removing the EGFP gene in RMT. Using the RMTv1 as a backbone, we generated a series of PEDV mutants carrying one or two attenuating mutations of non-structural protein 1 (nsp1), nsp15, and nsp16. Their replication efficiency, sensitivity to interferons (IFNs), induction of IFNs, and genetic stability were tested in Vero and/or LLC-PK1 cells. We selected RMTv1 and RMTv1-nsp1 + nsp15 for the pathogenesis studies in neonatal gnotobiotic pigs and tested the immunogenicity of RMTv1-nsp1 + nsp15. The RMTv1-nsp1 + nsp15 was further attenuated, causing no pig mortality, compared with RMTv1. All the pigs infected with RMTv1-nsp1 + nsp15 were protected from severe diarrhea and death post-challenge with virulent PEDV at 21 days post-inoculation, whereas 50% of mock-challenged piglets died. These findings establish RMTv1-nsp1 + nsp15 as a promising PEDV LAV candidate and can be further evaluated.IMPORTANCEPEDV continues to cause devastating economic losses in the global swine industry. Exposing pregnant sows to feedback materials from infected pigs is still one of the main methods used to control PEDV outbreaks in U.S. swine farms but carries the risk of transmitting other pathogens. Effective and safe vaccines are desperately needed to replace the feedback materials but are still not available. We revised the recombination-resistant vaccine backbone and combined it with targeted attenuation mutations in viral IFN antagonists to generate six PEDV mutants. Among them, the RMTv1-nsp1 + nsp15 had significant advancements in safety and protective efficacy in neonatal piglets, demonstrating its vaccine potential to control PEDV outbreaks and improve swine health globally. By addressing key challenges in LAV development, including risks of reversion to virulence and generation of new variants via recombination, this work establishes a robust foundation for PEDV vaccine strategies and potentially inspires the development of vaccines against other emerging coronaviruses.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0045125"},"PeriodicalIF":4.0,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144275149","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":"Correction for Gurda et al., \"Mapping a Neutralizing Epitope onto the Capsid of Adeno-Associated Virus Serotype 8\".","authors":"Brittney L Gurda, Christina Raupp, Ruth Popa-Wagner, Matthias Naumer, Norman H Olson, Robert Ng, Robert McKenna, Timothy S Baker, Jürgen A Kleinschmidt, Mavis Agbandje-McKenna","doi":"10.1128/jvi.00792-25","DOIUrl":"https://doi.org/10.1128/jvi.00792-25","url":null,"abstract":"","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0079225"},"PeriodicalIF":4.0,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144275146","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":"Replication-deficient whole-virus vaccines against cytomegalovirus induce protective immunity in a guinea pig congenital infection model.","authors":"Mark R Schleiss, Claudia Fernández-Alarcón, Craig J Bierle, Adam P Geballe, Alexey Badillo-Guzman, Christine E Tanna, Kanokpan Tsriwong, Mark Blackstad, Jian Ben Wang, Michael A McVoy","doi":"10.1128/jvi.00207-25","DOIUrl":"https://doi.org/10.1128/jvi.00207-25","url":null,"abstract":"<p><p>Vaccines are needed to prevent congenital human cytomegalovirus (HCMV) infections. This study used the guinea pig cytomegalovirus (GPCMV) model to examine replication-deficient whole-virus vaccines for protection against maternal viremia and congenital CMV infection. Two recombinant GPCMVs, GP51-DD and GP52-DD, were engineered with destabilization domains fused to the essential viral late proteins GP51 and GP52. These viruses, predicted to replicate in the presence of the synthetic ligand Shield-1 but not in its absence, were evaluated for Shield-1 dependence <i>in vitro</i> and for safety, immunogenicity, and efficacy in the GPCMV model. GP52-DD was profoundly Shield-1-dependent, producing no detectable infectious progeny in its absence. In contrast, the replication of GP51-DD was delayed in the absence of Shield-1 but reached similar peak titers with or without the compound. GPCMV-seronegative guinea pigs received two subcutaneous injections of phosphate-buffered saline, GP51-DD, GP52-DD, or wild-type GPCMV (WT-GPCMV). DNAemia attributable to vaccination was noted in 10/10 (100%) of WT-GPCMV-immunized animals but in only 10/28 animals (36%) immunized with DD vaccines (<i>P</i> < 0.001). GPCMV-specific ELISA and interferon-gamma ELISpot responses were similar in all vaccinated groups. When immunized animals were bred and challenged during pregnancy with virulent GPCMV, DNAemia was detected in all sham-immunized controls and in 44% of GP52-DD-immunized dams (at significantly reduced levels) but was absent in dams immunized with GP51-DD or WT-GPCMV. Immunization with GP52-DD, GP51-DD, or WT-GPCMV significantly reduced congenital GPCMV transmission compared to placebo (protective efficacies of 89, 94, and 100%, respectively). Thus, replication-impaired GP51-DD and replication-deficient GP52-DD vaccines were comparable to WT-GPCMV in immunogenicity and protective efficacy.IMPORTANCECongenital HCMV infections could potentially be prevented by a vaccine, but most vaccines that have advanced in clinical trials have been modestly effective, at best. Subunit HCMV vaccines chiefly target envelope glycoproteins, but none has proven effective at engendering durable protective immunity. A vaccine that confers immune responses to a broader repertoire of immunogens than a subunit vaccine, such as a whole-virus, live-attenuated vaccine, could confer improved protection. However, there are safety concerns for live-attenuated HCMV vaccines. Using the GPCMV model of congenital infection, this study demonstrates that two replication-impaired whole virus vaccines, though attenuated in animals, are highly immunogenic and induce preconception immunity that protects against maternal viremia and fetal infection after wild-type GPCMV challenge during pregnancy.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0020725"},"PeriodicalIF":4.0,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144266528","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":"IFIT3 RNA-binding activity promotes influenza A virus infection and translation efficiency.","authors":"Owen M Sullivan, Daniel J Nesbitt, Grace A Schaack, Elizabeth M Feltman, Thomas Nipper, Supasek Kongsomros, Sevilla G Reed, Sarah L Nelson, Cason R King, Evgenia Shishkova, Joshua J Coon, Andrew Mehle","doi":"10.1128/jvi.00286-25","DOIUrl":"10.1128/jvi.00286-25","url":null,"abstract":"<p><p>Host cells produce a vast network of antiviral factors in response to viral infection. The interferon-induced proteins with tetratricopeptide repeats (IFITs) are important effectors of a broad-spectrum antiviral response. In contrast to their canonical roles, we previously identified IFIT2 and IFIT3 as pro-viral host factors during influenza A virus (IAV) infection. During IAV infection, IFIT2 binds and enhances translation of AU-rich cellular mRNAs, including many IFN-stimulated gene products, establishing a model for its broad antiviral activity. However, IFIT2 also binds viral mRNAs and enhances their translation, resulting in increased viral replication. The ability of IFIT3 to bind RNA and whether this is important for its function was not known. Here, we validate direct interactions between IFIT3 and RNA using electrophoretic mobility shift assays. RNA-binding site identification experiments then identified an RNA-binding surface composed of residues conserved in IFIT3 orthologs and IFIT2 paralogs. Mutation of the RNA-binding site reduced the ability of IFIT3 to promote IAV gene expression and translation efficiency compared to wild-type IFIT3. The functional units of IFIT2 and IFIT3 are homo- and heterodimers; however, the RNA-binding surfaces are located near the dimerization interface. Using co-immunoprecipitation, we showed that mutations to these sites do not affect dimerization. Together, these data establish the link between IFIT3 RNA binding and its ability to modulate translation of viral mRNAs during IAV infection.IMPORTANCEInfluenza A viruses (IAVs) cause considerable morbidity and mortality through sporadic pandemics as well as annual epidemics. Zoonotic IAV strains pose an additional risk of spillover into a naive human population where prior immunity may have minimal effect. In this case, the first line of defense in the host is the innate immune response. Interferon-stimulated genes (ISGs) produce a suite of proteins that are front-line effectors of innate immune responses. While ISGs are typically considered antiviral, new research has revealed an emerging trend where viruses co-opt ISGs for pro-viral function. Here, we determine how the ISG IFIT3 is used by IAV as a pro-viral factor, advancing our understanding of IFIT3 function generally and specifically in the context of IAV infection.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0028625"},"PeriodicalIF":4.0,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144266527","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":"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}