Journal of Virology最新文献

{"title":"Herpes simplex virus 1 envelope glycoprotein C shields glycoprotein D to protect virions from entry-blocking antibodies.","authors":"McKenna A Hull, Suzanne M Pritchard, Anthony V Nicola","doi":"10.1128/jvi.00090-25","DOIUrl":"10.1128/jvi.00090-25","url":null,"abstract":"<p><p>Herpes simplex virus 1 (HSV-1) gD interaction with the host cell receptor nectin-1 triggers the membrane fusion cascade during viral entry. Potent neutralizing antibodies to gD prevent receptor-binding or prevent gD interaction with gH/gL critical for fusion. HSV has many strategies to evade host immune responses. We investigated the ability of virion envelope gC to protect envelope gD from antibody neutralization. HSV-1 lacking gC was more sensitive to neutralization by anti-gD monoclonal antibodies than a wild-type rescuant virus. gD in the HSV-1 gC-null viral envelope had enhanced reactivity to anti-gD antibodies compared to wild type. Soluble nectin-1 bound similar to HSV-1 particles regardless of the presence of gC in the envelope. However, entry of HSV-1 ΔgC was more sensitive to inhibition by soluble nectin-1 receptor. The viral membrane protein composition of HSV-1 ΔgC is equivalent to that of wild type, suggesting that the lack of gC is responsible for the increased reactivity of gD-specific antibodies and the consequent increased susceptibility to neutralization by those antibodies. Together, the results suggest that gC in the HSV-1 envelope shields both receptor-binding domains and gH/gL-interacting domains of gD from neutralizing antibodies, facilitating HSV cell entry.IMPORTANCEHSV-1 causes lifelong infections. There is no vaccine and no cure. Understanding HSV immune evasion strategies is an important goal. HSV-1 gC is a multi-functional envelope glycoprotein. This study suggests that virion gC physically shields neighboring gD from antibodies, including neutralizing monoclonal antibodies. This mechanism may allow HSV to escape immune detection, promoting HSV infection in the host.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0009025"},"PeriodicalIF":4.0,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143710427","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":"Coordination of the host Vps4-Vta1 complex and the viral core protein Ac93 facilitates entry of Autographa californica multiple nucleopolyhedrovirus budded virions.","authors":"Xiaorong Yue, Ning Ji, Yixiang Ma, Qianlong Yu, Lisha Bai, Zhaofei Li","doi":"10.1128/jvi.02182-24","DOIUrl":"https://doi.org/10.1128/jvi.02182-24","url":null,"abstract":"<p><p>The endosomal sorting complex required for transport (ESCRT) is a protein machine mediating membrane scission. In intraluminal vesicle (ILV) formation, ESCRT-0 targets cargoes and recruits ESCRT-I/-II to create membrane invagination, whereas ESCRT-III coordinates with the AAA ATPase Vps4 and its cofactor Vta1 to catalyze the membrane fission. Recently, ESCRT-I/-III and Vps4 were found to be involved in the entry of the baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV). However, the necessity of other ESCRT components and the interplay of viral proteins and ESCRTs in regulating the virus entry remain elusive. Here, we identified ESCRT-0 (Hse1 and Vps27), ESCRT-II (Vps22, Vps25, and Vps36), and Vta1 of <i>Spodoptera frugiperda</i>. RNAi depletion of Vta1 but not the components of ESCRT-0 or ESCRT-II in Sf9 cells significantly reduced budded virus (BV) production. Quantitative PCR together with confocal microscopy analyses indicated that Vta1 was required for internalization and endosomal trafficking of BV. In the late phase of infection, although Vps4 and Vta1 were both distributed to the nucleus and at the plasma membrane, depletion of Vta1 did not affect BV release. Further analysis revealed that 7 of 14 BV envelope proteins (Ac75, Ac93, E25, F-like, P33, P48, and vUbiquitin) interacted with Vps4 and Vta1. Intriguingly, Ac93 adopted a similar mode as ESCRT-III proteins to interact with the microtubule-interacting and transport (MIT) domains of Vps4 and Vta1 via its C-terminal MIT-interacting motifs (MIM1), and the interactions were necessary for BV internalization. Together, our studies highlight the coordination of Vps4-Vta1 and Ac93, and probably other BV envelope proteins, in facilitating entry of AcMNPV.IMPORTANCEThe endosomal sorting complex required for transport (ESCRT) system is involved in the entry of diverse DNA and RNA viruses. However, the interplay of viral proteins and ESCRTs in promoting virus endocytosis remains largely unknown. Here, we found that the ESCRT early acting factors ESCRT-0/-II were not necessary for infectious budded virus (BV) production of Autographa californica multiple nucleopolyhedrovirus (AcMNPV). In contrast, the Vps4 cofactor Vta1 was required for entry but not egress of BV. Several core or essential BV envelope proteins were identified to interact with Vps4 and Vta1. Among them, Ac93 plays a central role in connecting other viral proteins and mimics ESCRT-III proteins to interact with Vps4-Vta1, facilitating entry of BV virions. These studies provide evidence for the coordination of viral proteins and ESCRTs in regulating entry of large enveloped DNA viruses.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0218224"},"PeriodicalIF":4.0,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143710474","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":"Early 2022 breakthrough infection sera from India target the conserved cryptic class 5 epitope to counteract immune escape by SARS-CoV-2 variants.","authors":"Indrani Das Jana, Kawkab Kanjo, Subhanita Roy, Munmun Bhasin, Shatarupa Bhattacharya, Indranath Banerjee, Subhasis Jana, Arjun Chatterjee, Alok Kumar Chakrabarti, Suman Chakraborty, Budhaditya Mukherjee, Raghavan Varadarajan, Arindam Mondal","doi":"10.1128/jvi.00051-25","DOIUrl":"https://doi.org/10.1128/jvi.00051-25","url":null,"abstract":"<p><p>During the coronavirus disease 2019 (COVID-19) pandemic, the vast majority of epitope mapping studies have focused on sera from mRNA-vaccinated populations from high-income countries. In contrast, here, we report an analysis of 164 serum samples isolated from patients with breakthrough infection in India during early 2022 who received two doses of the ChAdOx viral vector vaccine. Sera were screened for neutralization breadth against wild-type (WT), Kappa, Delta, and Omicron BA.1 viruses. Three sera with the highest neutralization breadth and potency were selected for epitope mapping, using charged scanning mutagenesis coupled with yeast surface display and next-generation sequencing. The mapped sera primarily targeted the recently identified class 5 cryptic epitope and, to a lesser extent, the class 1 and class 4 epitopes. The class 5 epitope is completely conserved across all severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants and for most sarbecoviruses. Based on these observations, an additional 26 sera were characterized, and all showed a broad neutralizing activity, including against XBB.1.5. This is in contrast with the results obtained with the sera from individuals receiving multiple doses of original and updated mRNA vaccines, where impaired neutralization of XBB and later variants of concern (VOCs) were observed. Our study demonstrates that two doses of the ChAdOx vaccine in a highly exposed population were sufficient to drive substantial neutralization breadth against emerging and upcoming variants of concern. These data highlight the important role of hybrid immunity in conferring broad protection and inform future vaccine strategies to protect against rapidly mutating viruses.</p><p><strong>Importance: </strong>Worldwide implementation of coronavirus disease 2019 (COVID-19) vaccines and the parallel emergence of newer severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants have shaped the humoral immune response in a population-specific manner. While characterizing this immune response is important for monitoring disease progression at the population level, it is also imperative for developing effective countermeasures in the form of novel vaccines and therapeutics. India has implemented the world's second largest COVID-19 vaccination drive and encountered a large number of post-vaccination \"breakthrough\" infections. From a cohort of patients with breakthrough infection, we identified individuals whose sera showed broadly neutralizing immunity against different SARS-CoV-2 variants. Interestingly, these sera primarily target a novel cryptic epitope, which was not identified in previous population-level studies conducted in Western countries. This rare cryptic epitope remains conserved across all SARS-CoV-2 variants, including recently emerged ones and for the SARS-like coronaviruses that may cause future outbreaks, thus representing a potential target for future vaccines.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0005125"},"PeriodicalIF":4.0,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143710423","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":"Role of glycosylation mutations at the N-terminal domain of SARS-CoV-2 XEC variant in immune evasion, cell-cell fusion, and spike stability.","authors":"Pei Li, Julia N Faraone, Cheng Chih Hsu, Michelle Chamblee, Yajie Liu, Yi-Min Zheng, Yan Xu, Claire Carlin, Jeffrey C Horowitz, Rama K Mallampalli, Linda J Saif, Eugene M Oltz, Daniel Jones, Jianrong Li, Richard J Gumina, Joseph S Bednash, Kai Xu, Shan-Lu Liu","doi":"10.1128/jvi.00242-25","DOIUrl":"10.1128/jvi.00242-25","url":null,"abstract":"<p><p>Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to evolve, producing new variants that drive global coronavirus disease 2019 surges. XEC, a recombinant of KS.1.1 and KP.3.3, contains T22N and F59S mutations in the spike protein's N-terminal domain (NTD). The T22N mutation, similar to the DelS31 mutation in KP.3.1.1, introduces a potential N-linked glycosylation site in XEC. In this study, we examined the neutralizing antibody (nAb) response and mutation effects in sera from bivalent-vaccinated healthcare workers, BA.2.86/JN.1 wave-infected patients, and XBB.1.5 monovalent-vaccinated hamsters, assessing responses to XEC alongside D614G, JN.1, KP.3, and KP.3.1.1. XEC demonstrated significantly reduced neutralization titers across all cohorts, largely due to the F59S mutation. Notably, removal of glycosylation sites in XEC and KP.3.1.1 substantially restored nAb titers. Antigenic cartography analysis revealed XEC to be more antigenically distinct from its common ancestral BA.2.86/JN.1 compared to KP.3.1.1, with the F59S mutation as a determining factor. Similar to KP.3.1.1, XEC showed reduced cell-cell fusion relative to its parental KP.3, a change attributed to the T22N glycosylation. We also observed reduced S1 shedding for XEC and KP.3.1.1, which was reversed by ablation of T22N and DelS31 glycosylation mutations, respectively. Molecular modeling suggests that T22N and F59S mutations of XEC alter hydrophobic interactions with adjacent spike protein residues, impacting both conformational stability and neutralization. Overall, our findings underscore the pivotal role of NTD mutations in shaping SARS-CoV-2 spike biology and immune escape mechanisms.IMPORTANCEThe continuous evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to the emergence of novel variants with enhanced immune evasion properties, posing challenges for current vaccination strategies. This study identifies key N-terminal domain (NTD) mutations, particularly T22N and F59S in the recent XEC variant, which significantly impacts antigenicity, neutralization, and spike protein stability. The introduction of an N-linked glycosylation site through T22N, along with the antigenic shift driven by F59S, highlights how subtle mutations can drastically alter viral immune recognition. By demonstrating that glycosylation site removal restores neutralization sensitivity, this work provides crucial insights into the molecular mechanisms governing antibody escape. Additionally, the observed effects on spike protein shedding and cell-cell fusion contribute to a broader understanding of variant fitness and transmissibility. These findings emphasize the importance of monitoring NTD mutations in emerging SARS-CoV-2 lineages and support the need for adaptive vaccine designs to counteract ongoing viral evolution.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0024225"},"PeriodicalIF":4.0,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143709842","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 I177L induces host inflammatory responses by facilitating the TRAF6-TAK1 axis and NLRP3 inflammasome assembly.","authors":"Pan-Xue Wu, Wen-Ping Yang, Tao Feng, Jing Zhang, Guo-Qiang Zhu, Xu-Guang Du, Yi Ru, Yao-Feng Zhao, Sen Wu, Dan Li, Hai-Xue Zheng","doi":"10.1128/jvi.02080-24","DOIUrl":"https://doi.org/10.1128/jvi.02080-24","url":null,"abstract":"<p><p>African swine fever virus (ASFV) is the pathogen of African swine fever (ASF), and its infection causes a lethal disease in pigs, with severe pathological lesions. These changes indicate excessive inflammatory responses in infected pigs, which is the main cause of death, but the ASFV proteins worked in this physiological process and the mechanisms underlying ASFV-induced inflammation remain unclear. Here, we identify that viral I177L works in these inflammatory responses. Mechanistically, I177L facilitates TRAF6 ubiquitination that enhances its binding to TAK1, which promotes TAK1 ubiquitination and phosphorylation. These processes depend on the E3 ubiquitin ligase activity of TRAF6. The upregulation of I177L to TRAF6-TAK1 interaction and TAK1 activation is responsible for I177L's activated effect on the NF-κB signaling pathway. Additionally, I177L promotes assembly of the NLRP3 inflammasome and ASC oligomerization, thus leading to the activation of the NLRP3 inflammasome and the production and secretion of mature IL-1β. TAK1 inhibition efficiently reverses ASFV-activated NF-κB signaling and inflammatory responses and suppresses ASFV replication. Furthermore, I177L-deficient ASFV induces milder inflammatory responses in pigs compared with parental ASFV, which still protects pigs against ASFV challenge. The finding confirms ASFV I177L as an important proinflammatory protein <i>in vitro</i> and <i>in vivo</i> and reveals a key mechanism underlying ASFV-mediated inflammatory responses for the first time, which enriches our knowledge of the complex ASFV, thus benefiting our understanding of the interplay between ASFV infection and the host's inflammatory responses.IMPORTANCEAfrican swine fever (ASF) is a devastating viral disease in pigs, and excessive inflammatory responses induced by ASFV mainly cause death. Thus, the study of the proinflammatory virulent proteins and the detailed mechanisms are important to ASF control. Here, I177L was demonstrated to be an essential protein in ASFV-mediated inflammation, which performs by simultaneously activating the NF-κB signaling and the NLRP3 inflammasome. The finding elucidates the molecular mechanism underlying ASFV-activated inflammatory responses for the first time. It provides a theoretical foundation for reducing the high mortality caused by excessive inflammation and opens new avenues for small-molecule drug development and vaccine design targeting ASFV.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0208024"},"PeriodicalIF":4.0,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143710468","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":"Abortive PDCoV infection triggers Wnt/β-catenin pathway activation, enhancing intestinal stem cell self-renewal and promoting chicken resistance.","authors":"Shuai Zhang, Yanan Cao, Yanjie Huang, Xueli Zhang, Chunxiao Mou, Tao Qin, Zhenhai Chen, Wenbin Bao","doi":"10.1128/jvi.00137-25","DOIUrl":"https://doi.org/10.1128/jvi.00137-25","url":null,"abstract":"<p><p>Porcine deltacoronavirus (PDCoV) is an emerging coronavirus causing economic losses to swine industries worldwide. PDCoV can infect chickens under laboratory conditions, usually with no symptoms or mild symptoms, and may cause outbreaks in backyard poultry and wildfowl, posing a potential risk of significant economic loss to the commercial poultry industry. However, the reasons for such a subdued reaction after infection are not known. Here, using chicken intestinal organoid monolayers, we found that although PDCoV infects them nearly as well as porcine intestinal organoid monolayers, infection did not result in detectable amounts of progeny virus. In <i>ex vivo</i> and <i>in vivo</i> experiments using chickens, PDCoV infection failed to initiate interferon and inflammatory responses. Additionally, infection did not result in a disrupted intestinal barrier nor a reduced number of goblet cells and mucus secretion, as in pigs. In fact, the number of goblet cells increased as did the secreted mucus, thereby providing an enhanced protective barrier. <i>Ex vivo</i> PDCoV infection in chicken triggered activation of the Wnt/β-catenin pathway with the upregulation of Wnt/β-catenin pathway genes (<i>Wnt3a</i>, <i>Lrp5</i>, <i>β-catenin</i>, and <i>TCF4</i>) and Wnt target genes (<i>Lgr5</i>, <i>cyclin D1</i>, and <i>C-myc</i>). This activation stimulates the self-renewal of intestinal stem cells (ISCs), accelerating ISC-mediated epithelial regeneration by significant up-regulation of <i>PCNA</i> (transiently amplifying cells), <i>BMI1</i> (ISCs), and <i>Lyz</i> (Paneth cells). Our data demonstrate that abortive infection of PDCoV in chicken cells activates the Wnt/β-catenin pathway, which facilitates the self-renewal and proliferation of ISCs, contributing to chickens' resistance to PDCoV infection.IMPORTANCEThe intestinal epithelium is the main target of PDCoV infection and serves as a physical barrier against pathogens. Additionally, ISCs are charged with tissue repair after injury, and promoting rapid self-renewal of intestinal epithelium will help to re-establish the physical barrier and maintain intestinal health. We found that PDCoV infection in chicken intestinal organoid monolayers resulted in abortive infection and failed to produce infectious virions, disrupt the intestinal barrier, reduce the number of goblet cells and mucus secretion, and induce innate immunity, but rather increased goblet cell numbers and mucus secretion. Abortive PDCoV infection activated the Wnt/β-catenin pathway, enhancing ISC renewal and accelerating the renewal and replenishment of shed PDCoV-infected intestinal epithelial cells, thereby enhancing chicken resistance to PDCoV infection. This study provides novel insights into the mechanisms underlying the mild or asymptomatic response to PDCoV infection in chickens, which is critical for understanding the virus's potential risks to the poultry industry.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0013725"},"PeriodicalIF":4.0,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143710465","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":"Addition of a short HIV-1 fusion-inhibitory peptide to PRO 140 antibody dramatically increases its antiviral breadth and potency.","authors":"Hongxia Yan, Yue Gao, Yuanmei Zhu, Huihui Chong, Yani Gong, Yue Chen, Li Li, Bin Su, Yuxian He","doi":"10.1128/jvi.02018-24","DOIUrl":"https://doi.org/10.1128/jvi.02018-24","url":null,"abstract":"<p><p>PRO 140, a humanized anti-HIV monoclonal antibody targeting the cell coreceptor CCR5, is currently under clinical trials, but it only affects CCR5-tropic viruses. In this study, we have engineered two tandem fusion proteins (2P23-PRO140SC and 2P23-PRO140-Fc) with bifunctional activity by adding short fusion-inhibitory peptide 2P23 to the single-chain fragment variable (scFv) of PRO 140 (PRO140SC) with or without the Fc domain of human IgG4. We first demonstrated that 2P23-PRO140SC and 2P23-PRO140-Fc could efficiently bind to the cell membranes through CCR5 anchoring, which did not affect the expression level of CCR5 on the cell surface. We then verified that the addition of 2P23 peptide to PRO140SC enabled a very potent activity against CXCR4-tropic HIV-1 isolates. As expected, the bispecific fusion proteins exhibited highly potent activities in inhibiting divergent HIV-1 subtypes and viral mutants that were resistant to the fusion inhibitors 2P23 and T20, and they displayed relatively low <i>in vitro</i> cytotoxicity. Furthermore, both the fusion proteins had robust <i>in vivo</i> anti-HIV activities in rats, with 2P23-PRO140-Fc much better than 2P23-PRO140SC. In conclusion, our studies have provided bispecific HIV-1 inhibitors that overcome the drawbacks of PRO 140 antibody and offered novel tools for studying the mechanisms of HIV-1 infection.IMPORTANCEGiven that HIV-1 evolves with high variability and drug resistance, the development of novel antivirals is important. CCR5-directed antibody PRO 140 is currently under clinical trials, but it only inhibits CCR5-tropic HIV-1 isolates. The designed fusion proteins by adding a minimum fusion-inhibitory peptide to PRO 140 enable dramatically increased activities in inhibiting both CCR5-tropic and CXCR4-tropic viruses, thus offering novel antiviral agents with a bispecific functionality that can overcome the drawbacks of PRO 140 antibody.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0201824"},"PeriodicalIF":4.0,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143700858","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 retinoblastoma protein contributes to maintaining the stability of HPV E7 in cervical cancer cells.","authors":"Ifeoluwa Gbala, Nezka Kavcic, Lawrence Banks","doi":"10.1128/jvi.02203-24","DOIUrl":"https://doi.org/10.1128/jvi.02203-24","url":null,"abstract":"<p><p>High-risk human papillomaviruses (HR HPV)-16 and -18, and other closely related subtypes, are associated with at least 90% of human cervical cancers. Cervical cancers and derived cell lines continuously express high levels of the HPV oncoprotein E7, known to degrade the tumor suppressor retinoblastoma protein (pRB). This E7-pRB interaction is important for the maintenance and progression of malignancy. In the case of HPV E6, substrate recognition has been reported to play an important role in stabilizing the viral oncoprotein; however, such regulation of E7 has so far not been investigated. Using biochemical, immunostaining, and clonogenic assays, we describe an intriguing role for pRB in the stabilization of E7 oncoprotein in HPV-positive cervical-cancer-derived cell lines. The knockdown of pRB expression by RNA interference results in a significant decrease in the levels of E7 protein in CaSki, SiHa, HeLa, and C-4 I cells. We show that pRB knockdown regulates HPV E7 at the transcription and protein levels, and significantly reduces the half-life of E7 protein by at least twofold in SiHa and HeLa cells. We also demonstrate that the destabilization of E7 caused by pRB knockdown results in significant inhibition of cell proliferation and colony formation of HPV-16 and -18 E7-positive SiHa and HeLa cells. Furthermore, the expression of wild-type pRB in pRB-depleted cells significantly restored E7 levels. Therefore, we propose that pRB, in addition to being a degradation target for HPV E7, is crucial for its stabilization.IMPORTANCEThe human papillomavirus (HPV) viral proteins E6 and E7 cooperatively contribute to tumorigenesis by disrupting cellular targets. These oncoproteins are degraded via the proteasome pathway; however, they are continuously expressed in cervical cancer cell lines. The retinoblastoma protein, pRB, is a degradation target of high-risk (HR) HPV E7 oncoprotein. Several studies have shown that the binding of E7 to pRB is important for its E7-mediated inactivation and demonstrated how pRB protein levels respond to the presence and absence of E7. However, the modulatory role of pRB on E7 protein levels has so far not been reported. Here, we report a novel regulatory relationship between E7 and pRB. We found that the continuous expression of pRB is critical for E7 stabilization. We demonstrate that this pRB-related E7 destabilization occurs in part through enhanced protein turnover. Thus, our findings provide new insights into the importance of the E7-pRB interaction in driving tumorigenesis.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0220324"},"PeriodicalIF":4.0,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143700918","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":"Human long noncoding RNA <i>VILMIR</i> is induced by major respiratory viral infections and modulates the host interferon response.","authors":"Kristen John, Ian Huntress, Ethan Smith, Hsuan Chou, Tammy S Tollison, Sergio Covarrubias, Elisa Crisci, Susan Carpenter, Xinxia Peng","doi":"10.1128/jvi.00141-25","DOIUrl":"10.1128/jvi.00141-25","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Long noncoding RNAs (lncRNAs) are a newer class of noncoding transcripts identified as key regulators of biological processes. Here, we aimed to identify novel lncRNA targets that play critical roles in major human respiratory viral infections by systematically mining large-scale transcriptomic data sets. Using bulk RNA-sequencing (RNA-seq) analysis, we identified a previously uncharacterized lncRNA, named virus-inducible lncRNA modulator of interferon response (&lt;i&gt;VILMIR&lt;/i&gt;), that was consistently upregulated after &lt;i&gt;in vitro&lt;/i&gt; influenza infection across multiple human epithelial cell lines and influenza A virus subtypes. &lt;i&gt;VILMIR&lt;/i&gt; was also upregulated after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and respiratory syncytial virus (RSV) infections &lt;i&gt;in vitro&lt;/i&gt;. We experimentally confirmed the response of &lt;i&gt;VILMIR&lt;/i&gt; to influenza infection and interferon-beta (IFN-β) treatment in the A549 human epithelial cell line and found the expression of &lt;i&gt;VILMIR&lt;/i&gt; was robustly induced by IFN-β treatment in a dose- and time-specific manner. Single-cell RNA-seq analysis of bronchoalveolar lavage fluid samples from coronavirus disease 2019 (COVID-19) patients uncovered that &lt;i&gt;VILMIR&lt;/i&gt; was upregulated across various cell types, including at least five immune cells. The upregulation of &lt;i&gt;VILMIR&lt;/i&gt; in immune cells was further confirmed in the human T cell and monocyte cell lines, SUP-T1 and THP-1, after IFN-β treatment. Finally, we found that knockdown of &lt;i&gt;VILMIR&lt;/i&gt; expression reduced the magnitude of host transcriptional responses to both IFN-β treatment and influenza A virus infection in A549 cells. Together, our results show that &lt;i&gt;VILMIR&lt;/i&gt; is a novel interferon-stimulated gene (ISG) that regulates the host interferon response and may be a potential therapeutic target for human respiratory viral infections upon further mechanistic investigation.IMPORTANCEIdentifying host factors that regulate the immune response to human respiratory viral infection is critical to developing new therapeutics. Human long noncoding RNAs (lncRNAs) have been found to play key regulatory roles during biological processes; however, the majority of lncRNA functions within the host antiviral response remain unknown. In this study, we identified that a previously uncharacterized lncRNA, virus-inducible lncRNA modulator of interferon response (&lt;i&gt;VILMIR&lt;/i&gt;), is upregulated after major respiratory viral infections including influenza, severe acute respiratory syndrome coronavirus 2, and respiratory syncytial virus. We demonstrated that &lt;i&gt;VILMIR&lt;/i&gt; is an interferon-stimulated gene that is upregulated after interferon-beta (IFN-β) in several human cell types. We also found that knockdown of &lt;i&gt;VILMIR&lt;/i&gt; reduced the magnitude of host transcriptional responses to IFN-β treatment and influenza A infection in human epithelial cells. Our results reveal that &lt;i&gt;VILMIR&lt;/i&gt; regulates the host interferon response and may present a new therapeut","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0014125"},"PeriodicalIF":4.0,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143700874","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":"HSV-1 infection induces a downstream shift of the +1 nucleosome.","authors":"Elena Weiß, Adam W Whisnant, Thomas Hennig, Lara Djakovic, Lars Dölken, Caroline C Friedel","doi":"10.1128/jvi.02086-24","DOIUrl":"https://doi.org/10.1128/jvi.02086-24","url":null,"abstract":"<p><p>Herpes simplex virus 1 (HSV-1) infection induces a loss of host transcriptional activity and widespread disruption of host transcription termination, which leads to an induction of open chromatin downstream of genes. In this study, we show that lytic HSV-1 infection also leads to an extension of chromatin accessibility at promoters into downstream regions. This is most prominent for highly expressed genes and independent of the HSV-1 proteins ICP0, ICP22, ICP27, and <i>vhs</i>. ChIPmentation of the noncanonical histone variant H2A.Z, which is strongly enriched at +1 and -1 nucleosomes, indicated that these chromatin accessibility changes are linked to a downstream shift of +1 nucleosomes. In yeast, downstream shifts of +1 nucleosomes are induced by RNA polymerase II (Pol II) degradation. Accordingly, irreversible depletion of Pol II from genes in human cells using α-amanitin altered +1 nucleosome positioning similar to lytic HSV-1 infection. Consequently, treatment with phosphonoacetic acid and knockout of ICP4, which both prevent viral DNA replication and alleviate the loss of Pol II from host genes, largely abolished the downstream extension of accessible chromatin in HSV-1 infection. In the absence of viral genomes, doxycycline-induced expression of ICP27, which redirects Pol II from gene bodies into intergenic regions by disrupting transcription termination, induced an attenuated effect that was further enhanced by co-expression of ICP22. In summary, our study provides strong evidence that HSV-1-induced depletion of Pol II from the host genome leads to a downstream shift of +1 nucleosomes at host promoters.IMPORTANCELytic herpes simplex virus 1 (HSV-1) infection leads to a profound host transcription shutoff. Loss of RNA polymerase II (Pol II) in yeast has previously been shown to relax +1 nucleosome positioning to more thermodynamically favorable sites downstream of transcription start sites. Here, we show that a similar phenomenon is likely at play in lytic HSV-1 infection. Sequencing of accessible chromatin revealed a widening of nucleosome-free regions at host promoters into downstream regions. By mapping genome-wide positions of the noncanonical histone variant H2A.Z enriched at +1 and -1 nucleosomes, we demonstrate a downstream shift of +1 nucleosomes for most cellular genes in lytic HSV-1 infection. As chemical depletion of Pol II from genes also leads to a downstream shift of +1 nucleosomes in human cells, changes in chromatin architecture at promoters in HSV-1 infection are likely a consequence of HSV-1-induced loss of Pol II activity from the host genome.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0208624"},"PeriodicalIF":4.0,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143700868","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}