Journal of Virology最新文献

{"title":"Perturbation of <i>de novo</i> lipogenesis hinders MERS-CoV assembly and release, but not the biogenesis of viral replication organelles.","authors":"M Soultsioti, A W M de Jong, N Blomberg, A Tas, M Giera, E J Snijder, M Bárcena","doi":"10.1128/jvi.02282-24","DOIUrl":"10.1128/jvi.02282-24","url":null,"abstract":"<p><p>Coronaviruses hijack host cell metabolic pathways and resources to support their replication. They induce extensive host endomembrane remodeling to generate viral replication organelles and exploit host membranes for assembly and budding of their enveloped progeny virions. Because of the overall significance of host membranes, we sought to gain insight into the role of host factors involved in lipid metabolism in cells infected with Middle East respiratory syndrome coronavirus (MERS-CoV). We employed a single-cycle infection approach in combination with pharmacological inhibitors, biochemical assays, lipidomics, and light and electron microscopy. Pharmacological inhibition of acetyl-CoA carboxylase (ACC) and fatty acid synthase (FASN), key host factors in <i>de novo</i> fatty acid biosynthesis, led to pronounced inhibition of MERS-CoV particle release. Inhibition of ACC led to a profound metabolic switch in Huh7 cells, altering their lipidomic profile and inducing lipolysis. However, despite the extensive changes induced by the ACC inhibitor, the biogenesis of viral replication organelles remained unaffected. Instead, ACC inhibition appeared to affect the trafficking and post-translational modifications of the MERS-CoV envelope proteins. Electron microscopy revealed an accumulation of nucleocapsids in early budding stages, indicating that MERS-CoV assembly is adversely impacted by ACC inhibition. Notably, inhibition of palmitoylation resulted in similar effects, while supplementation of exogenous palmitic acid reversed the compound's inhibitory effects, possibly reflecting a crucial need for palmitoylation of the MERS-CoV spike and envelope proteins for their role in virus particle assembly.IMPORTANCEMiddle East respiratory syndrome coronavirus (MERS-CoV) is the etiological agent of a zoonotic respiratory disease of limited transmissibility between humans. However, MERS-CoV is still considered a high-priority pathogen and is closely monitored by WHO due to its high lethality rate of around 35% of laboratory-confirmed infections. Like other positive-strand RNA viruses, MERS-CoV relies on the host cell's endomembranes to support various stages of its replication cycle. However, in spite of this general reliance of MERS-CoV replication on host cell lipid metabolism, mechanistic insights are still very limited. In our study, we show that pharmacological inhibition of acetyl-CoA carboxylase (ACC), a key enzyme in the host cell's fatty acid biosynthesis pathway, significantly disrupts MERS-CoV particle assembly without exerting a negative effect on the biogenesis of viral replication organelles. Furthermore, our study highlights the potential of ACC as a target for the development of host-directed antiviral therapeutics against coronaviruses.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0228224"},"PeriodicalIF":4.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11915874/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143458552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intraductal infection with H5N1 clade 2.3.4.4b influenza virus.","authors":"Ericka Kirkpatrick Roubidoux, Victoria Meliopoulos, Brandi Livingston, Pamela H Brigleb, Stacey Schultz-Cherry","doi":"10.1128/jvi.01927-24","DOIUrl":"10.1128/jvi.01927-24","url":null,"abstract":"","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0192724"},"PeriodicalIF":4.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11915852/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143065591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","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":"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":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11915859/pdf/","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":"OA","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":"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":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11915860/pdf/","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":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diversities of African swine fever virus host-virus dynamics revealed by single-cell profiling.","authors":"Xiaoyang Zhao, Yanyan Zhang, Hanying Jia, Lin Lv, Md Asif Ahsan, Xudong Fu, Rongliang Hu, Zhiqiang Shen, Ning Shen","doi":"10.1128/jvi.02035-24","DOIUrl":"10.1128/jvi.02035-24","url":null,"abstract":"<p><p>African swine fever virus (ASFV) causes epidemics with high mortality; however, effective vaccines and therapies remain missing. Here, we depict a temporal single-cell landscape of primary porcine alveolar macrophages (PAMs) exposed to three different virulent ASFV strains <i>in vitro</i>. We found that attenuated and low-virulence ASFV strains tend to exhibit higher viral loads than highly virulent strain, which may result from upregulated RNA polymerase subunit genes expression. On the host side, our study highlights the IRF7-mediated positive feedback loop to the activation of the interferon signaling pathway in cells exposed to attenuated and low virulent ASFV strains. Moreover, we unraveled the PAMs populations marked by expressions of the <i>IFI16</i> and <i>CD163</i>, respectively, which produce high levels of interferon-stimulated genes (ISGs) and IL18 to regulate the host response to different virulent ASFV strains. Collectively, our data provide insights into the complex host-virus interactions with various ASFV strain infections, which may shed light on the development of effective antiviral strategies.IMPORTANCEThere is still no available research on the temporal transcriptional profile of host cells exposed to different virulent ASFV strains at the single-cell level. Here, we first profiled the temporal viral and host transcriptomes in PAMs exposed to high virulent, attenuated virulent, and low virulent ASFV strains. Our analysis revealed that attenuated and low-virulence ASFV strains tend to exhibit higher viral loads than highly virulent strains, which may result from upregulated RNA polymerase subunit genes expression. We also found a positive feedback loop of the interferon signaling pathway mediated through IRF7 and identified the populations of PAMs marked by <i>IFI6</i> and <i>CD163</i>, respectively, which produce high levels of ISGs and <i>IL18</i> to regulate host response to different virulent ASFV strains. Our study delineated a comprehensive single-cell landscape of host-virus dynamics across ASFV strains with different virulences and would provide an important resource for future research.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0203524"},"PeriodicalIF":4.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11917525/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143391125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A capsidless (+)RNA yadokarivirus hosted by a dsRNA virus is infectious as particles, cDNA, and dsRNA.","authors":"Muhammad Fadli, Sakae Hisano, Guy Novoa, José R Castón, Hideki Kondo, Nobuhiro Suzuki","doi":"10.1128/jvi.02166-24","DOIUrl":"10.1128/jvi.02166-24","url":null,"abstract":"<p><p>Capsidless yadokariviruses (members of the order <i>Yadokarivirales</i>) with (+)RNA genomes divert the capsid of their partner icosahedral double-stranded RNA (dsRNA) viruses in different families of the order <i>Ghabrivirales</i> into the replication site. A yadokarivirus, AfSV2, has been reported from a German strain of the ascomycete fungus <i>Aspergillus foetidus</i> coinfected by two dsRNA viruses, a victorivirus (AfSV1<i>,</i> family <i>Pseudototiviridae</i>) and an alternavirus (AfFV, family <i>Alternaviridae</i>). Here, we identified AfSV1 as the partner of AfSV2 in a Japanese <i>A. foetidus</i> strain after showing the infectiousness of AfSV2 in three forms: virus particles (heterocapsid), transforming full-length complementary DNA (cDNA), and purified replicated form (RF) dsRNA that is believed to be inactive as a translational template. Virion transfection of virus-free <i>A. foetidus</i> protoplasts resulted in the generation of two strains infected either by AfSV1 alone or by both AfSV1 and AfSV2. Transformants with AfSV2 full-length cDNA launched AfSV2 infection only in the presence of AfSV1, but not those with AfSV2 RNA-directed RNA polymerase mutant cDNA. The purified fractions containing AfSV2 RF dsRNA also launched infection when transfected into protoplasts infected by AfSV1. Treatment with dsRNA-specific RNase III, but not with proteinase K, S1 nuclease, or DNase I, abolished the infectivity of AfSV2 RF dsRNA. Furthermore, we confirmed the infectiousness of gel-purified AfSV2 RF dsRNA in the presence of AfSV1. Taken together, our results show the unique infectious entity of AfSV2 and the expansion of yadokarivirus partners in the family <i>Pseudototiviridae</i> and provide interesting evolutionary insights.IMPORTANCEThe viral phylum <i>Pisuviricota</i> accommodates members with both double-stranded RNA (dsRNA) and (+)RNA genomes. Some members of the second group display peculiar virus lifestyles. These include (+)RNA yadkariviruses, which are capsidless and highjack the capsid of their partner dsRNA viruses in the order <i>Ghabrivirales</i> of a different phylum <i>Duplornaviricota</i>. We identified the partner dsRNA virus (AfSV1, a victorivirus) of a yadokarivirus (AfSV2) from the ascomycete <i>Aspergillus foetidus</i>. AfSV2 is infectious in the presence of AfSV1 in three forms: purified particles, transforming full-length complementary DNA, and, surprisingly, the purified replicative form dsRNA. These combined results expand yadokarivirus partner viruses to the family <i>Pseudototiviridae</i> and provide evidence for AfSV2 as a unique infectious entity as well as interesting evolutionary insights.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0216624"},"PeriodicalIF":4.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11915832/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143408640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Changes in the dynamic characteristics of G-protein can alter the immune-protection efficacy of rabies virus vaccine.","authors":"Chang-Xu Chen, Xi Wang, Wen Su, Yuan Tian, Yu Gao, Dong-Lan Liu, Hong Xiang, Bo-Chuan Liu, Jin-Li Shi, Yang Zhang, Dong Shen, Wen-Zhi He, Li Yang, Chao Hong, Fan Wu, Lei-Tai Shi, Yi-Na Cun, Jian Zhou","doi":"10.1128/jvi.01954-24","DOIUrl":"10.1128/jvi.01954-24","url":null,"abstract":"<p><p>The efficacy of the G-protein is influenced by N-linked glycosylation, which serves as the sole immunogen of the rabies virus vaccine. However, achieving satisfactory immune-protection efficacy remains challenging, owing to the heterogeneous glycosylation of G-proteins. Within molecular dynamics, examining the impact of N-glycan heterogeneity on the structural characteristics of G-proteins provides insights into the relationship between antigens and the efficacy of rabies virus vaccines. Glycosylation is regulated by host cells. In rabies virus cultured in Vero cells (VRV), all N-glycosylation sites of the G-protein underwent modification. In contrast, rabies virus G-protein cultured in KMB17 cells (human diploid cell vaccine [HDCV]) was only modified by N-glycans at amino acid positions 247 and 319. Furthermore, treatment of VRV with de-glycosylation significantly improved its immune-protective efficacy, whereas de-glycosylation did not alter the immune-protective efficacy of HDCV. To support the impact of glycosylation on VRV efficacy, the structures and dynamics of G-proteins were analyzed using GROMACS. Specifically, the hydrophobicity, flexibility, and radius of gyration of the G-protein trimer in VRV were significantly altered by excessive hydrogen bonds formed by the three-branched hybrid glycan at the aa 319 site. These changes increase the instability of the G-protein trimer and may lead to a decrease in vaccine protective efficacy. Ultimately, we determined that N-glycan heterogeneity affects the immune-protection effect of antigen proteins by altering their dynamic characteristics, enhancing our understanding of the correlation between antigen structural characteristics and efficacy.</p><p><strong>Importance: </strong>N-glycosylation of rabies virus glycoprotein dynamically regulates protein folding, stability, and antigenicity. Therefore, regulation of N-glycan modification is key to improving vaccine stability and protective efficacy. How the type and modification sites of N-glycans affect the protective efficacy of rabies vaccines remains unclear. Our research indicates that there are differences in the protective efficacy of rabies virus G-proteins modified with different N-glycans. Moreover, the modification of the three-branched hybrid glycan at the aa 319 site of G-protein significantly altered the hydrophobicity, flexibility, and radius, and increased its trimeric antigen instability through molecular dynamics demonstrations. These findings update the current understanding of the impact of glycans on vaccine antigenicity and develop a system to evaluate the stability of antigen glycoproteins based on molecular dynamics.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0195424"},"PeriodicalIF":4.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11915851/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143468128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diversifying T-cell responses: safeguarding against pandemic influenza with mosaic nucleoprotein.","authors":"Hongtae Park, Brock Kingstad-Bakke, Thomas Cleven, Myunghwan Jung, Yoshihiro Kawaoka, M Suresh","doi":"10.1128/jvi.00867-24","DOIUrl":"10.1128/jvi.00867-24","url":null,"abstract":"<p><p>Pre-existing T-cell responses have been linked to reduced disease severity and better clinical outcomes during the 2009 influenza pandemic and the recent COVID-19 pandemic. We hypothesized that diversifying T-cell responses, particularly targeting conserved viral proteins such as the influenza A virus (IAV) nucleoprotein (NP), could protect against both epidemic and pandemic IAV strains. To test this, we created a mosaic nucleoprotein (MNP) by synthesizing a sequence that maximized the representation of 9-mer epitopes from 7422 NP sequences across human, swine, and avian IAVs. Notably, the MNP sequence showed high homology with the NP of the H5N1 strain affecting dairy cows in the ongoing outbreak. Mucosal immunization with the adjuvanted MNP vaccine induced robust CD8 and CD4 T-cell responses against both known immunodominant and <i>in silico</i> predicted subdominant epitopes. MNP-vaccinated mice challenged with epidemic H1N1 and H3N2 strains, which shared immunodominant CD8 and/or CD4 T-cell epitopes, showed a significant (~4 log) reduction in lung viral load. Importantly, MNP-vaccinated mice challenged with a pandemic H1N1 strain lacking shared immunodominant CD8 or CD4 epitopes exhibited a superior reduction in lung viral load, linked to T-cell responses targeting subdominant epitopes present in both the MNP and pandemic strain NP. These results suggest that a diversified T-cell response induced by the MNP vaccine could provide broad protection against severe disease from both current and emerging IAV strains.</p><p><strong>Importance: </strong>The World Health Organization (WHO) estimates that seasonal influenza causes 3-5 million cases of severe illness annually. The influenza virus frequently undergoes genetic changes through antigenic drift and antigenic shift, resulting in annual epidemics and occasional pandemics. Consequently, a major public health objective is to develop a universal influenza vaccine that offers broad protection against both current and pandemic influenza A strains. In this study, we designed a nucleoprotein (NP) antigen (termed mosaic NP) comprising antigenic regions found in thousands of influenza viruses, aiming to use it as a vaccine to induce broad anti-influenza T-cell responses. Our findings indicate that the mosaic NP vaccine provided significant protection against seasonal H1N1 and H3N2, as well as the pandemic H1N1 strain, demonstrating its effectiveness across various influenza subtypes. These findings suggest that the mosaic NP is a potential universal influenza vaccine antigen, capable of protecting against diverse strains of influenza viruses.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0086724"},"PeriodicalIF":4.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11915837/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143080624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"HSV-1 virions and related particles: biogenesis and implications in the infection.","authors":"Maria Kalamvoki","doi":"10.1128/jvi.01076-24","DOIUrl":"10.1128/jvi.01076-24","url":null,"abstract":"<p><p>Virion formation and egress are sophisticated processes that rely on the spatial and temporal organization of host cell membranes and the manipulation of host machineries involved in protein sorting, membrane bending, fusion, and fission. These processes result in the formation of infectious virions, defective particles, and various vesicle-like structures. In herpes simplex virus 1 (HSV-1) infections, virions and capsid-less particles, known as light (L)-particles, are formed. HSV-1 infection also stimulates the release of particles that resemble extracellular vesicles (EVs). In productively infected cells, most EVs are generated through the CD63 tetraspanin biogenesis pathway and lack viral components. A smaller subset of EVs, generated through the endosomal sorting complexes required for transport (ESCRT) pathway, contains both viral and host factors. Viral mechanisms tightly regulate EV biogenesis, including the inhibition of autophagy-a process critical for increased production of CD63+ EVs during HSV-1 infection. Mutant viruses that fail to suppress autophagy instead promote microvesicle production from the plasma membrane. Additionally, the viral protein ICP0 (Infected Cell Protein 0) enhances EV biogenesis during HSV-1 infection. The different types of particles can be separated by density gradients due to their distinct biophysical properties. L-particles and ESCRT+ EVs display a pro-viral role, supporting viral replication, whereas CD63+ EVs exhibit antiviral effects. Overall, these studies highlight that HSV-1 infection yields numerous and diverse particles, with their type and composition shaped by the ability of the virus to evade host responses. These particles likely shape the infectious microenvironment and determine disease outcomes.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0107624"},"PeriodicalIF":4.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11915793/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143080631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling suggests SARS-CoV-2 rebound after nirmatrelvir-ritonavir treatment is driven by target cell preservation coupled with incomplete viral clearance.","authors":"Tin Phan, Ruy M Ribeiro, Gregory E Edelstein, Julie Boucau, Rockib Uddin, Caitlin Marino, May Y Liew, Mamadou Barry, Manish C Choudhary, Dessie Tien, Karry Su, Zahra Reynolds, Yijia Li, Shruti Sagar, Tammy D Vyas, Yumeko Kawano, Jeffrey A Sparks, Sarah P Hammond, Zachary Wallace, Jatin M Vyas, Jonathan Z Li, Mark J Siedner, Amy K Barczak, Jacob E Lemieux, Alan S Perelson","doi":"10.1128/jvi.01623-24","DOIUrl":"10.1128/jvi.01623-24","url":null,"abstract":"<p><p>In a subset of SARS-CoV-2-infected individuals treated with the antiviral nirmatrelvir-ritonavir, the virus rebounds following treatment. The mechanisms driving this rebound are not well understood. We used a mathematical model to describe the longitudinal viral load dynamics of 51 individuals treated with nirmatrelvir-ritonavir, 20 of whom rebounded. Target cell preservation, either by a robust innate immune response or initiation of N-R near the time of symptom onset, coupled with incomplete viral clearance, appears to be the main factor leading to viral rebound. Moreover, the occurrence of viral rebound is likely influenced by the time of treatment initiation relative to the progression of the infection, with earlier treatments leading to a higher chance of rebound. A comparison with an untreated cohort suggests that early treatments with nirmatrelvir-ritonavir may be associated with a delay in the onset of an adaptive immune response. Nevertheless, our model demonstrates that extending the course of nirmatrelvir-ritonavir treatment to a 10-day regimen may greatly diminish the chance of rebound in people with mild-to-moderate COVID-19 and who are at high risk of progression to severe disease. Altogether, our results suggest that in some individuals, a standard 5-day course of nirmatrelvir-ritonavir starting around the time of symptom onset may not completely eliminate the virus. Thus, after treatment ends, the virus can rebound if an effective adaptive immune response has not fully developed. These findings on the role of target cell preservation and incomplete viral clearance also offer a possible explanation for viral rebounds following other antiviral treatments for SARS-CoV-2.</p><p><strong>Importance: </strong>Nirmatrelvir-ritonavir is an effective treatment for SARS-CoV-2. In a subset of individuals treated with nirmatrelvir-ritonavir, the initial reduction in viral load is followed by viral rebound once treatment is stopped. We show that the timing of treatment initiation with nirmatrelvir-ritonavir may influence the risk of viral rebound. Nirmatrelvir-ritonavir stops viral growth and preserves target cells but may not lead to full clearance of the virus. Thus, once treatment ends, if an effective adaptive immune response has not adequately developed, the remaining virus can lead to rebound. Our results provide insights into the mechanisms of rebound and can help develop better treatment strategies to minimize this possibility.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0162324"},"PeriodicalIF":4.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11915799/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143189671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}