Journal of Virology最新文献

{"title":"Effect of host telomerase inhibition on human cytomegalovirus.","authors":"Chloe M Cavanaugh, Cora N Betsinger, Nicole Katchur, Sherry Zhang, Karen Yang, Maciej Nogalski, Ileana M Cristea, Daniel Notterman","doi":"10.1128/jvi.01578-24","DOIUrl":"https://doi.org/10.1128/jvi.01578-24","url":null,"abstract":"<p><p>Treatment options remain limited for human cytomegalovirus (HCMV). Host telomerase has been implicated in the pathogenesis and oncogenesis of multiple herpesviruses, most recently including HCMV. In this study, we investigated the effect of telomerase inhibition on HCMV replication, as well as the mechanism of the interaction between HCMV and host telomerase <i>in vitro</i>. We found that lytic HCMV infection increases host telomerase activity, at least in part, through modulation of hTERT expression during earlier phases of the HCMV replication cycle. We found telomerase inhibition strongly reduced viral titer for two HCMV strains in a dose-specific manner. Both post-translational pharmaceutical telomerase inhibition and siRNA-mediated knockdown of hTERT reduce HCMV yield. Telomerase inhibition results in both reduction of viral gene and protein expression across the HCMV replication cycle, and suppressed viral genome replication and viral infectivity, suggesting interference with at least early steps of the HCMV viral life cycle. Altogether, our findings indicate telomerase plays an important, perhaps non-canonical role in lytic HCMV infection which includes the support of viral replication and infectivity.</p><p><strong>Importance: </strong>Human cytomegalovirus (HCMV) seroprevalence and morbidity in immunocompromised patients and neonates infected <i>in utero</i> remain high globally. Host telomerase has been implicated in the success of multiple infection-induced pathologies, including the success of both lytic infection and oncogenesis in certain herpesviruses. The results of this study suggest a similar biologically important role for host telomerase in lytic HCMV infection. Furthermore, these results may provide the potential for a novel, adjunctive anti-viral treatment for HCMV infection as well as insight into the viral products likely to be involved with HCMV regulation of telomerase.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0157824"},"PeriodicalIF":4.0,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143189658","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 Japanese encephalitis virus NS1 protein concentrates ER membranes in a cytoskeleton-independent manner to facilitate viral replication.","authors":"Shengda Xie, Xinxin Lin, Qing Yang, Miaolei Shi, Xingmiao Yang, Ziyu Cao, Ruibing Cao","doi":"10.1128/jvi.02113-24","DOIUrl":"https://doi.org/10.1128/jvi.02113-24","url":null,"abstract":"<p><p>Orthoflaviviruses remodel the endoplasmic reticulum (ER) network to construct replication organelles (ROs) for RNA replication. In this study, we demonstrate that the Japanese encephalitis virus (JEV) NS1 protein concentrates ER membranes in the perinuclear region, which provides a substantial membrane source for viral replication. Subsequently, the virus forms main replication organelles within this membrane-concentrated area to facilitate efficient replication. This process relies on the ER localization signal, glycosylation, dimerization, and membrane-binding sites of the NS1 protein. In conclusion, our study highlights the role of the NS1 protein in the formation of the ROs by JEV, providing new insights into orthoflavivirus replication.IMPORTANCEOrthoflaviviruses use the endoplasmic reticulum (ER) membranes for replication by forming invaginations to assemble the replication organelles. Here, we found that Japanese encephalitis virus (JEV) utilizes the NS1 protein to concentrate a significant number of ER membranes in the perinuclear area, thereby providing a membrane source for viral replication and facilitating the formation of main replication organelles (MROs). This process depends on the ER localization signals of NS1, as well as its glycosylation, dimerization, and membrane-binding sites, but not on the cytoskeleton. In summary, our study highlights how NS1 remodels ER membranes to facilitate the formation of MROs for JEV, thereby accelerating viral replication.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0211324"},"PeriodicalIF":4.0,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143188879","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":"Biophysical and structural insights into AAV genome ejection.","authors":"Keely Gliwa, Joshua Hull, Austin Kansol, Victoria Zembruski, Renuk Lakshmanan, Mario Mietzsch, Paul Chipman, Antonette Bennett, Robert McKenna","doi":"10.1128/jvi.00899-24","DOIUrl":"https://doi.org/10.1128/jvi.00899-24","url":null,"abstract":"<p><p>Recombinant adeno-associated virus (rAAV) is comprised of non-enveloped capsids that can package a therapeutic transgene and are currently being developed and utilized as gene therapy vectors. The therapeutic efficiency of rAAV is dependent on successful cytoplasmic trafficking and transgene delivery to the nucleus. It is hypothesized that an increased understanding of the effects of the cellular environment and biophysical properties of the capsid as it traffics to the nucleus could provide insight to improve vector efficiency. The AAV capsid is exposed to increasing [H⁺] during endo-lysosomal trafficking. Exposure to low pH facilitates the externalization of the viral protein 1 unique region (VP1u). This VP1u contains a phospholipase A2 domain required for endosomal escape and nuclear localization signals that facilitate nuclear targeting and entry. The viral genome is released either after total capsid disassembly or via a concerted DNA ejection mechanism in the nucleus. This study presents the characterization of genome ejection (GE) for two diverse serotypes, AAV2 and AAV5, using temperature. The temperature required to disassemble the virus capsid (T_M) is significantly higher than the temperature required to expose the transgene (T_E) for both serotypes. This was verified by quantitative PCR (qPCR) and transmission electron microscopy. Additionally, the absence of VP1/VP2 in the capsids and a decrease in pH increase the temperature of GE. Furthermore, cryo-electron microscopy structures of the AAV5 capsid pre- and post-GE reveal dynamics at the twofold, threefold, and fivefold regions of the capsid interior consistent with a concerted egress of the viral genome.IMPORTANCEThe development of recombinant adeno-associated virus (rAAV) capsids has grown rapidly in recent years, with five of the eight established therapeutics gaining approval in the past 2 years alone. Clinical progression with AAV2 and AAV5 represents a growing need to further characterize the molecular biology of these viruses. The goal of AAV-based gene therapy is to treat monogenic disorders with a vector-delivered transgene to provide wild-type protein function. A better understanding of the dynamics and conditions enabling transgene release may improve therapeutic efficiency. In addition to their clinical importance, AAV2 and 5 were chosen in this study for their diverse antigenic and biophysical properties compared to more closely related serotypes. Characterization of a shared genome ejection process may imply a conserved mechanism for all rAAV therapies.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0089924"},"PeriodicalIF":4.0,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143189648","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":"Longitudinal changes in the transcriptionally active and intact HIV reservoir after starting ART during acute infection.","authors":"Julie Janssens, Adam Wedrychowski, Sun Jin Kim, Cordelia Isbell, Rebecca Hoh, Satish K Pillai, Timothy J Henrich, Steven G Deeks, Nadia R Roan, Sulggi A Lee, Steven A Yukl","doi":"10.1128/jvi.01431-24","DOIUrl":"https://doi.org/10.1128/jvi.01431-24","url":null,"abstract":"<p><p>Even in antiretroviral therapy (ART)-suppressed human immunodeficiency virus (HIV)-infected individuals, there are heterogeneous populations of HIV-expressing cells exhibiting variable degrees of progression through blocks to HIV transcriptional initiation, elongation, completion, and splicing. These HIV-transcribing cells likely contribute to HIV-associated immune activation and inflammation as well as the viral rebound that occurs after stopping ART. However, it is unclear whether the blocks to HIV transcription are present before ART and how the timing and duration of ART may affect the clearance of cells expressing HIV transcripts that differ in their processivity and/or presence of mutations. To investigate these questions, we quantified different types of HIV transcripts and the corresponding HIV DNA regions/proviruses in longitudinal blood samples obtained before ART initiation (T1) and after 6 months (T2) and 1 year (T3) of ART in 16 individuals who initiated ART during acute HIV infection. Before ART, the pattern of HIV transcripts suggested blocks to elongation and splicing, and only ~10% of intact proviruses were transcribing intact HIV RNA. During the first 6 months of ART, we detected progressively greater reductions in initiated, 5'-elongated, mid-transcribed, completed, and multiply spliced HIV transcripts. Completed HIV RNA decayed faster than initiated or 5'-elongated HIV RNA, and intact HIV RNA tended to decay faster than defective HIV RNA. HIV DNA and RNA levels at T1-T3 correlated inversely with baseline CD4+ T-cell counts. Our findings suggest the existence of immune responses that act selectively to reduce HIV transcriptional completion and/or preferentially kill cells making completed or intact HIV RNA.IMPORTANCEEven in virologically suppressed HIV-infected individuals, expression of viral products from both intact and defective proviruses may contribute to HIV-associated immune activation and inflammation, which are thought to underlie the organ damage that persists despite suppressive ART. We investigated how the timing of ART initiation and the duration of ART affect the heterogeneous populations of HIV-transcribing cells, including a detailed characterization of the different HIV transcripts produced before ART and the rate at which they decay after ART initiation during acute HIV infection. Even during untreated infection, most cells (~90%) have blocks at some stage of transcription. Furthermore, different HIV transcripts decline at different rates on ART, with the fastest decay of cells making completed and intact HIV RNA. Our results suggest that intrinsic or extrinsic immune responses act selectively to either reduce particular stages of HIV transcription or cause selective killing of cells making particular HIV transcripts.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0143124"},"PeriodicalIF":4.0,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143189662","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":"Usutu virus-induced meningoencephalitis in immunocompetent mice is characterized by the recruitment of mononuclear cells and a proinflammatory T helper 1 response.","authors":"Rebeca Froes Rocha, Laís D Coimbra, Marina A Fontoura, Guilherme Ribeiro, Giuliana Eboli Sotorilli, Giovanni F Gomes, Alexandre Borin, Jaqueline Felipe, Emily Slowikowski, Wilias Silva Santos Greison, Thiago M Cunha, Pedro Elias Marques, Pedro M M Vieira, Rafael Elias Marques","doi":"10.1128/jvi.01724-24","DOIUrl":"https://doi.org/10.1128/jvi.01724-24","url":null,"abstract":"<p><p>Usutu virus (USUV) is an arbovirus and has emerged as a potential cause of encephalitis in humans and other vertebrates. The increasing detection of USUV in mosquitoes and birds across Africa and Central Europe, along with the lack of specific treatments or vaccines for many encephalitic orthoflaviviruses, underscores the need for focused research. In this study, we developed a USUV infection model in immunocompetent C57BL/6 mice (8-12 weeks old) to characterize disease development and associated inflammatory mechanisms. Mice were intracranially infected with 10⁴ PFU of USUV, leading to neurological symptoms such as hunched posture, paralysis, conjunctivitis, and eventual death by day 6 post-infection. Meningeal cell infiltration and microglia activation were most prevalent in mouse brains; however, neuronal loss was not observed at the peak of the disease, which coincided with increased viral load and leukocyte infiltration. The immune response in the brain was marked by the systematic recruitment and activation of macrophages, neutrophils, and T lymphocytes. A noticeable shift was seen in CD4+ T cells toward T helper 1 (Th1) polarization, which corroborates a massive increase in the expression of Th1-associated cytokines and chemokines at the peak of infection, indicative of an augmented proinflammatory state. Additionally, a rise in regulatory T cells was observed, peaking on day 6 post-infection. These findings highlight the dynamic nature of the host response to USUV infection, enhance our understanding of the disease pathogenesis, and address the scarcity of immunocompetent experimental models for the investigation of neglected emerging flaviviruses.IMPORTANCEMosquito-borne viruses, including USUV, are maintained in nature through complex cycles involving arthropod vectors and vertebrate hosts. A comprehensive understanding of USUV biology and host-pathogen interactions is crucial for developing effective treatments, which necessitates reliable experimental models (G. J. Sips, J. Wilschut, and J. M. Smit, Rev Med Virol 22:69-87, 2012, https://doi.org/10.1002/rmv.712; T. C. Pierson and M. S. Diamond, Nat Microbiol 5:796-812, 2020, https://doi.org/10.1038/s41564-020-0714-0). The establishment of a USUV infection model in immunocompetent adult mice brings new perspectives on the inflammatory component of viral encephalitis, which is difficult to study in mice lacking antiviral interferon responses. Moreover, USUV is an emerging viral disease lacking therapeutic and preventive measures. The interplay of USUV pathogenesis and the host's immune response indicates that lymphocytes and monocytes participate in USUV infection in this model and could be explored in search of treatments targeting immunopathogenic processes triggered by infection.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0172424"},"PeriodicalIF":4.0,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143189001","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":"Class B scavenger receptor resists WSSV replication by recognizing the viral lipid molecule and promoting phagocytosis.","authors":"Yi-Heng Huang, Xin-Lu Guo, Meng-Ke Shan, Gui-Wen Yang, Hui-Ting Yang","doi":"10.1128/jvi.01700-24","DOIUrl":"https://doi.org/10.1128/jvi.01700-24","url":null,"abstract":"<p><p>Class B scavenger receptors (SRBs) have been well-studied in bacteria-induced immune responses in invertebrates. However, the status of SRB-defending viruses remains unclear. In this study, we identified a scavenger receptor in <i>Procambarus clarkii</i> (crayfish), which is homologous to mammalian SRBs, and designated it as <i>Pc</i>SRB. The expression of <i>Pc</i>SRB was upregulated after the WSSV challenge. The survival rate of crayfish was decreased, but the WSSV copy number increased after <i>Pc</i>SRB knockdown during virus invasion. In addition, <i>Pc</i>SRB bound to WSSV. Furthermore, we detected how <i>Pc</i>SRB interacted with WSSV, and we found that <i>Pc</i>SRB could bind to cholesta-3,5-diene, (CD3,5), a novel WSSV lipid ligand, rather than dibutyl phthalate (DBP). Besides, <i>Pc</i>SRB could bind to VP19, VP26, and VP28, rather than VP24. Mutant-binding experiments demonstrated that the hydrophobic domain (130-180 aa) of <i>Pc</i>SRB is important for recognizing WSSV. Furthermore, <i>Pc</i>SRB might promote lysosomal eliminating function to degrade WSSV. Altogether, we identified a new mechanism for scavenger receptor recognition and resistance to WSSV.IMPORTANCE<i>Pc</i>SRB could bind to WSSV directly. <i>Pc</i>SRB could interact with WSSV via binding to lipid molecule CD3,5 and viral envelope proteins. <i>Pc</i>SRB could influence lysosomal activation.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0170024"},"PeriodicalIF":4.0,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143189651","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":"RAF1 promotes successful human cytomegalovirus replication and is regulated by AMPK-mediated phosphorylation during infection.","authors":"Diana M Dunn, Ludia J Pack, Joshua C Munger","doi":"10.1128/jvi.01866-24","DOIUrl":"10.1128/jvi.01866-24","url":null,"abstract":"<p><p>RAF1 is a key player in growth factor receptor signaling, which has been linked to multiple viral infections, including human cytomegalovirus (HCMV) infection. Although HCMV remains latent in most individuals, it can cause acute infection in immunocompromised populations, such as transplant recipients, neonates, and cancer patients. Current treatments are suboptimal, highlighting the need for novel therapies. Multiple points in the growth factor signaling pathway are important for HCMV infection, but the relationship between HCMV and RAF1, a component of the mitogen-activated protein kinase (MAPK) cascade, is not well understood. The AMP-activated protein kinase (AMPK) is a known regulator of RAF1, and AMPK activity is induced by HCMV infection, which is important for productive HCMV replication. Our data indicate that HCMV infection induces AMPK-specific changes in RAF1 protein phosphorylation, including increasing phosphorylation at RAF1-Ser621, a known AMPK phospho-site, which results in increased binding to the 14-3-3 scaffolding protein, an important aspect of RAF1 protein activation. Inhibition of RAF1, either pharmacologically or via shRNA or CRISPR-mediated targeting, inhibits viral replication and spread in both fibroblasts and epithelial cells. Collectively, our data indicate that HCMV infection and AMPK activation modulate RAF1 activity, which is important for viral replication.</p><p><strong>Importance: </strong>Human cytomegalovirus (HCMV) infection is a widespread infection impacting approximately 60-90% of the global population. Although latent in healthy individuals, acute infection in immunocompromised populations, such as neonates, transplant recipients, and cancer patients, can result in retinal and gastrointestinal problems, hearing loss, and even death. Current antivirals are suboptimal due to the development of viral resistance or toxicity in patients, highlighting the need for novel treatments. Our research suggests a new potential target, RAF1, which is a regulator of cellular growth and proliferation. We find that RAF1 is phosphorylated by AMP-activated protein kinase, and that inhibition of RAF1 negatively impacts viral infection. Furthermore, drugs currently used to treat certain cancers also inhibit RAF1 and may have an additional anti-HCMV therapeutic effect in HCMV-susceptible cancer patients.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0186624"},"PeriodicalIF":4.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143189714","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":"YTHDF1 and YTHDC1 m⁶A reader proteins regulate HTLV-1 <i>tax</i> and <i>hbz</i> activity.","authors":"Emily M King, Amanda Midkiff, Karsyn McClain, Sanggu Kim, Amanda R Panfil","doi":"10.1128/jvi.02063-24","DOIUrl":"https://doi.org/10.1128/jvi.02063-24","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Human T-cell leukemia virus type 1 (HTLV-1) is a retrovirus responsible for adult T-cell leukemia/lymphoma (ATLL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), a progressive neurodegenerative disease. Regulation of viral gene expression plays a key role in viral persistence and pathogenesis. However, the molecular mechanisms underlying this fine-tuned regulation remain poorly understood. Little is known regarding RNA chemical modifications of HTLV-1 RNA and how these affect viral biology and disease development. Post-transcriptional chemical modification of RNA is common in eukaryotes, with N&lt;sup&gt;6&lt;/sup&gt;-methyladenosine (m&lt;sup&gt;6&lt;/sup&gt;A) being the most prevalent. In this study, we investigated the role of m&lt;sup&gt;6&lt;/sup&gt;A RNA modifications on HTLV-1 gene expression. Using MeRIP-Seq, we mapped the sites of m&lt;sup&gt;6&lt;/sup&gt;A modification to the 3' end of the viral genome. We found HTLV-1 RNA, as well as viral oncogene transcripts &lt;i&gt;tax&lt;/i&gt; and &lt;i&gt;hbz&lt;/i&gt;, contained m&lt;sup&gt;6&lt;/sup&gt;A modifications. m&lt;sup&gt;6&lt;/sup&gt;A-depletion in HTLV-1-transformed cells decreased sense-derived viral genes (&lt;i&gt;Tax, Gag,&lt;/i&gt; and &lt;i&gt;Env&lt;/i&gt;) and increased antisense-derived &lt;i&gt;Hbz&lt;/i&gt; expression. &lt;i&gt;Tax&lt;/i&gt; and &lt;i&gt;hbz&lt;/i&gt; transcripts were bound by reader proteins YTHDF1 and YTHDC1 in a panel of HTLV-1 T-cell lines. Using expression vectors and shRNA-mediated knockdown, we found that YTHDF1 had opposing effects on viral gene expression, decreasing sense-derived viral genes and increasing antisense-derived &lt;i&gt;Hbz&lt;/i&gt;. Upon further study, the YTHDF1 effects on &lt;i&gt;tax&lt;/i&gt; abundance were dependent on &lt;i&gt;tax&lt;/i&gt; m&lt;sup&gt;6&lt;/sup&gt;A deposition. The nuclear m&lt;sup&gt;6&lt;/sup&gt;A reader protein YTHDC1 affected the abundance of both sense- and antisense-derived viral transcripts and specifically enhanced the nuclear export of &lt;i&gt;tax&lt;/i&gt; transcript. Collectively, our results demonstrate global m&lt;sup&gt;6&lt;/sup&gt;A levels and m&lt;sup&gt;6&lt;/sup&gt;A reader proteins YTHDF1 and YTHDC1 regulate HTLV-1 gene expression.IMPORTANCEHuman T-cell leukemia virus type 1 (HTLV-1) persistence and pathogenesis are controlled through tight regulation of viral gene expression. The fate of RNA can be controlled by epigenetic modifications that impact gene expression without altering the DNA sequence. Our study details the impact of N6-methyladenosine (m&lt;sup&gt;6&lt;/sup&gt;A) RNA chemical modifications on HTLV-1 gene expression. We found that reductions in global m&lt;sup&gt;6&lt;/sup&gt;A levels affected viral gene expression, decreasing &lt;i&gt;Tax&lt;/i&gt; and other sense-derived viral genes, whereas increasing the antisense-derived &lt;i&gt;Hbz&lt;/i&gt;. Our results suggest the oncogenic viral transcripts, &lt;i&gt;tax&lt;/i&gt; and &lt;i&gt;hbz&lt;/i&gt;, are m&lt;sup&gt;6&lt;/sup&gt;A-modified in cells. We found that these viral RNA modifications are interpreted by reader proteins YTHDF1 and YTHDC1, which dictate the fate of the viral RNA. Understanding HTLV-1 RNA chemical modifications offers potential insights into novel therapeutic strategies for HTLV-1-associated disease","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0206324"},"PeriodicalIF":4.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143189005","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":"Conventional and antibody-enhanced DENV infection of human macrophages induces differential immunotranscriptomic profiles.","authors":"Céline S C Hardy, Adam D Wegman, Mitchell J Waldran, Gary C Chan, Adam T Waickman","doi":"10.1128/jvi.01962-24","DOIUrl":"https://doi.org/10.1128/jvi.01962-24","url":null,"abstract":"<p><p>Dengue virus (DENV) is a mosquito-borne flavivirus which coexists as four genetically and immunologically distinct serotypes (DENV-1 to -4). In secondary heterologous DENV infection, pre-existing immunity is believed to contribute to severe disease through antibody-dependent enhancement (ADE). Although the elevated pathology observed in ADE conditions has been described, the cell-intrinsic mechanisms governing this process remain unclear. Using single-cell RNA sequencing (scRNAseq), we investigated the transcriptomic profiles of human monocyte-derived macrophages infected by DENV-2 in ADE compared to conventional infection conditions. Unsupervised analysis of scRNAseq data enabled the identification of two distinct cell populations in a heterogeneous cell culture, likely representing infected and bystander/uninfected cells. Differential gene expression and ingenuity pathway analyses revealed a number of significantly upregulated and downregulated genes and gene networks between cells infected by ADE compared to conventional infection. Specifically, these pathways indicated mechanisms such as suppressed interferon signaling and inflammatory chemokine transcription in cells infected via ADE. Further analysis revealed that transcriptomic changes were independent of viral RNA within infected cells, suggesting that the observed changes are reflective of cell-intrinsic responses and not simply a function of per-cell viral burden. The interpreted \"bystander\" cell population also demonstrated distinct profiles in ADE conditions, indicating an immunologically activated phenotype enriched for the expression of gene networks involved with protein translation, cytokine production, and antigen presentation. Together, these findings support the concept that DENV infection via ADE induces a qualitatively different transcriptomic response in infected cells, contributing to our understanding of ADE as a mechanistic driver of disease and pathogenesis.IMPORTANCEDengue virus (DENV) is a mosquito-borne human pathogen with a significant and growing global health burden. Although correlates of severe dengue disease are poorly understood, pre-existing immunity to DENV has been associated with severe disease risk and known to contribute to an alternative route of viral entry termed antibody-dependent enhancement (ADE). Using single-cell RNA sequencing, we identified distinct transcriptomic processes involved in antibody-mediated DENV entry compared to conventional receptor-mediated entry. These data provide meaningful insight into the discrete processes contributing to DENV pathogenesis in ADE conditions.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0196224"},"PeriodicalIF":4.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143189655","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":"Single-cell transcriptomics reveals a compartmentalized antiviral interferon response in the nasal epithelium of mice.","authors":"Xuefei Wang, Meng Dong, Xinchao Wu, Daniel Schnepf, Julia Thiel, Wenfei Sun, Christian Wolfrum, Sisi Li, Wenfei Jin, Peter Staeheli, Liang Ye","doi":"10.1128/jvi.01413-24","DOIUrl":"https://doi.org/10.1128/jvi.01413-24","url":null,"abstract":"<p><p>Type III interferons (IFNs) primarily act on epithelial cells and protect against virus infection of the mucosa, whereas type I IFNs act more systemically. To date, it has been unknown which epithelial subtypes in the upper airways, the primary site for initial infection for most respiratory viruses, primarily rely on type III IFN or type I IFNs for antiviral protection. To address this question, we performed a single-cell transcriptomics analysis of the epithelial IFN-mediated response focusing on the upper airways of mice. This work identified nine distinct cell types derived from the olfactory epithelium and thirteen distinct cell types from the respiratory epithelium. Interestingly, type I IFNs induced a stronger antiviral transcriptional response than type III IFN in respiratory epithelial cells, whereas in olfactory epithelial cells, including sustentacular (SUS) and Bowman's gland cells (BGC), type III IFN was more dominant compared to type I IFN. SUS and BGC, which provide structural support and maintain the integrity of olfactory sensory neurons, were highly susceptible to infection with a mouse-adapted variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 MA20) but were protected against infection if the animals were prophylactically treated with type III IFN. These findings demonstrate a high degree of cell type heterogeneity in terms of interferon-mediated antiviral responses and reveal a potent role for type III IFNs in protecting the olfactory epithelium.IMPORTANCESARS-CoV-2 infects SUS and BGC in the olfactory epithelium, causing an impairment of structural support and integrity of olfactory sensory neurons that can result in severe olfactory dysfunctions. We observed an unexpected compartmentalization of the IFN-mediated transcriptional response within the airway epithelium, and we found that olfactory epithelial cells preferentially respond to type III IFN, which resulted in robust antiviral protection of SUS and BGC. Given the proximity of the olfactory epithelium to the central nervous system, we hypothesize that evolution favored a type III IFN-biased antiviral immune response in this tissue to limit inflammatory responses in the brain. Cell type-specific antiviral responses in the upper airways, triggered by the different types of IFNs, should be investigated in more detail and carefully taken into consideration during the development of IFN-based antivirals for clinical use.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0141324"},"PeriodicalIF":4.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143189717","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}