Antiviral research最新文献

{"title":"Suppression of herpes simplex virus type 1 replication by Pin1 inhibitors: insights from H-77 and novel compounds","authors":"Abeer Mohamed Abdelfattah Elsayed ,&nbsp;Miuko Kurose ,&nbsp;Akifumi Higashiura ,&nbsp;Akima Yamamoto ,&nbsp;Toshihito Nomura ,&nbsp;Takashi Irie ,&nbsp;Masaya Fukushi ,&nbsp;Jeffrey Encinas ,&nbsp;Hisanaka Ito ,&nbsp;Takayoshi Okabe ,&nbsp;Tomoichiro Asano ,&nbsp;Takemasa Sakaguchi","doi":"10.1016/j.antiviral.2025.106244","DOIUrl":"10.1016/j.antiviral.2025.106244","url":null,"abstract":"<div><div>Herpes simplex virus type 1 (HSV-1) infection is widespread globally, necessitating the development of new therapeutic approaches. Previous studies have demonstrated that peptidyl-prolyl cis/trans isomerase Pin1 is essential for the replication of cytomegalovirus, a member of the herpesvirus family. Our research demonstrated that Pin1 knockdown significantly suppressed HSV-1 replication. Furthermore, we found that our Pin1 inhibitor H-77, along with four novel Pin1 inhibitors, also inhibited HSV-1 replication. The 50 % effective concentration (EC₅₀) of H-77 against HSV-1 replication in VeroE6 cells was 0.75 μM. In HSV-1-infected cells treated with H-77, expression levels of the immediate early viral protein ICP0 and late viral proteins VP5 and glycoprotein C (gC) were significantly reduced, indicating suppression of viral protein expression. Immunofluorescence staining revealed that in H-77-treated cells, viral proteins including VP5 were confined within the nucleus by an intact nuclear lamina. Transmission electron microscopy analysis demonstrated that H-77-treated cells exhibited markedly fewer extracellular viral particles, with nucleocapsid nuclear egress being inhibited. These results demonstrate that H-77 suppresses HSV-1 replication through dual mechanisms: inhibition of viral protein synthesis and blockade of nucleocapsid nuclear egress. These findings indicate that Pin1 represents a promising therapeutic target for HSV-1 inhibition, warranting further development of Pin1 inhibitors as anti-HSV-1 agents.</div></div>","PeriodicalId":8259,"journal":{"name":"Antiviral research","volume":"241 ","pages":"Article 106244"},"PeriodicalIF":4.5,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144714524","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":"Cerebrospinal fluid concentrations, viral suppression and biomarkers with long-acting cabotegravir and rilpivirine intramuscular injections","authors":"Aylin Yilmaz ,&nbsp;Amedeo De Nicolò ,&nbsp;Antonio D'Avolio ,&nbsp;Magnus Gisslén","doi":"10.1016/j.antiviral.2025.106243","DOIUrl":"10.1016/j.antiviral.2025.106243","url":null,"abstract":"<div><div>Our aim was to determine cerebrospinal fluid (CSF) and plasma concentrations of cabotegravir and rilpivirine (CAB/RPV) when administered as long-acting (LA) intramuscular injections every four (Q4W) or eight (Q8W) weeks, and to study the effect on viral suppression and CSF biomarkers of inflammation and neuronal injury. We included six adults with HIV receiving LA CAB/RPV Q4W or Q8W. CSF and plasma concentrations of CAB/RPV (15 samples) were analyzed by UHPLC-MS/MS. We also measured CSF and plasma HIV RNA, CSF and serum neopterin, CSF and serum β2-microglubulin, IgG index, albumin ratio, and CSF NfL. Median (range) total plasma cabotegravir concentrations were 1375 (963–2422) ng/mL, and in CSF 3.48 (1.47–7.60 ng/mL). For rilpivirine, concentrations were 93 (40–157) ng/mL and 1.21 (0.55–1.67) ng/mL, respectively. All participants hade CSF and plasma HIV RNA &lt;20 copies/mL on every occasion. There were no significant changes in any of the CSF biomarkers in participants after switching to LA CAB/RPV. The combination of LA CAB/RPV can achieve therapeutic CSF concentrations throughout the dosing intervals and may suppress HIV replication in the CNS. No significant changes in CSF biomarkers of inflammation or neuronal injury were observed, indicating a neutral CNS effect.</div></div>","PeriodicalId":8259,"journal":{"name":"Antiviral research","volume":"241 ","pages":"Article 106243"},"PeriodicalIF":4.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144717347","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":"Functional characteristics of plitidepsin as an antiviral treatment against monkeypox virus infection","authors":"Guillermo Albericio ,&nbsp;Daniel Rodríguez-Martín ,&nbsp;Pablo Avilés ,&nbsp;Carmen Cuevas ,&nbsp;María J. Guillén-Navarro ,&nbsp;María A. Noriega ,&nbsp;Sara Flores ,&nbsp;Pedro J. Sánchez-Cordón ,&nbsp;David Astorgano ,&nbsp;Patricia Pérez ,&nbsp;Mariano Esteban ,&nbsp;Juan García-Arriaza","doi":"10.1016/j.antiviral.2025.106238","DOIUrl":"10.1016/j.antiviral.2025.106238","url":null,"abstract":"<div><div>Monkeypox virus (MPXV), closely related to variola virus, causes mpox, a zoonotic disease traditionally endemic to Central Africa. However, recent outbreaks have increased human transmission of MPXV clades. In 2022, global MPXV spread was linked to clade IIb, whereas in 2024, the more pathogenic clade Ib became predominant. These trends raised concerns about sustained human transmission, prompting the WHO to declare mpox a Public Health Emergency of International Concern. Despite the availability of smallpox vaccines, their protective efficacy against mpox remains limited. Additionally, the limited efficacy of current smallpox antivirals, such as Tecovirimat and Brincidofovir, alongside growing concerns about the emergency of tecovirimat resistance mutants, underscores the need for new therapeutic options. Given these challenges, novel antiviral strategies with different mechanisms of action are urgently needed to control MPXV outbreaks. Plitidepsin, a cyclodepsipeptide drug initially approved for cancer treatment, has demonstrated potent antiviral activity against multiple viruses by targeting eukaryotic elongation factor 1 alpha (eEF1A). Here, we have evaluated the antiviral activity of plitidepsin against MPXV infection. In cultured cells, plitidepsin exhibited strong antiviral effects, with a favorable therapeutic index and low cytotoxicity. In CAST/EiJ mice, a highly susceptible MPXV model, plitidepsin significantly reduced viral replication in the lungs. Additionally, treated mice displayed a marked reduction in inflammatory lung lesions and proinflammatory cytokines, suggesting immunomodulatory effects. These findings indicate plitidepsin as a promising candidate for mpox treatment. Further studies are needed to explore its potential as a standalone or combination therapy, supporting clinical evaluation for mpox treatment.</div></div>","PeriodicalId":8259,"journal":{"name":"Antiviral research","volume":"241 ","pages":"Article 106238"},"PeriodicalIF":4.5,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144658230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-throughput split-GFP antiviral screening assay against fusogenic paramyxoviruses","authors":"Laura Vandemaele ,&nbsp;Thibault Francken ,&nbsp;Joost Schepers ,&nbsp;Winston Chiu ,&nbsp;Niels Cremers ,&nbsp;Hugo Klaassen ,&nbsp;Charlène Marcadet ,&nbsp;Lorena Sanchez Felipe ,&nbsp;Arnaud Marchand ,&nbsp;Patrick Chaltin ,&nbsp;Pieter Leyssen ,&nbsp;Johan Neyts ,&nbsp;Manon Laporte","doi":"10.1016/j.antiviral.2025.106242","DOIUrl":"10.1016/j.antiviral.2025.106242","url":null,"abstract":"<div><div>The paramyxovirus family includes important pathogens such as measles and mumps viruses, as well as emerging pathogens with pandemic potential such as Nipah virus. Despite the threat to public health and the frequent identification of novel paramyxoviruses, no antiviral drugs are currently available. A hallmark of most paramyxoviruses is the induction of cell-cell fusion leading to syncytia formation. To facilitate antiviral drug discovery, we leveraged this trait and established a high-throughput split-green fluorescent protein (GFP) antiviral screening assay suitable for high-content imaging through the quantification of virus-induced GFP⁺ syncytia. The assay was validated with well-known broad-spectrum antiviral compounds against representative members of five different <em>Paramyxovirinae</em> genera. Using this split-GFP assay, a small-molecule repurposing library of approximately 3000 compounds was screened against recombinant Cedar virus (CedV), a nonpathogenic henipavirus. Two molecules were identified: Cathepsin Inhibitor 1 with henipavirus-specific activity and PF-543 with pan-paramyxovirus activity. Both molecules inhibit viral replication by blocking cell-cell fusion. The split-GFP assay presented here will enable the development of extensive drug discovery initiatives aimed at identifying much-needed pan-henipavirus/paramyxovirus inhibitors.</div></div>","PeriodicalId":8259,"journal":{"name":"Antiviral research","volume":"241 ","pages":"Article 106242"},"PeriodicalIF":4.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144697462","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":"Cholesterol 25-hydroxylase inhibits Newcastle disease virus replication by its architectural damage and blocking HN protein","authors":"Satyendu Nandy,&nbsp;Siddharth Neog,&nbsp;Sachin Kumar","doi":"10.1016/j.antiviral.2025.106239","DOIUrl":"10.1016/j.antiviral.2025.106239","url":null,"abstract":"<div><div>Cholesterol 25-hydroxylase (CH25H) is a membrane-bound endoplasmic reticulum protein that converts cholesterol into 25-hydroxycholesterol (25HC). Recent studies showed that CH25H is an interferon-stimulated gene (ISG) that helps fight various viruses and has broad antiviral effects. However, the role of chicken CH25H (chCH25H) in controlling Newcastle disease virus (NDV) infection and replication remains unexplored. This study examined the impact of chCH25H on NDV infection in chicken embryo fibroblast cells. The results showed that cells try to upregulate the chCH25H expression temporally upon viral infection. Moreover, the overexpression of chCH25H reduced NDV infection in cells while reducing endogenous chCH25H levels increased its replication. Additionally, treating cells and viruses with 25HC, an active metabolic intermediate of chCH25H, significantly reduced NDV replication by blocking the virus from entering cells while causing significant structural damage to the virus architecture. In addition, <em>in ovo</em> results also exhibited that the eggs treated with lipopolysaccharides (LPS), a positive regulator of chCH25H and 25HC, resulted in extensive viral reduction. These findings indicate that chCH25H and 25HC are against NDV replication in chicken fibroblast cells.</div></div>","PeriodicalId":8259,"journal":{"name":"Antiviral research","volume":"241 ","pages":"Article 106239"},"PeriodicalIF":4.5,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144673836","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":"Decreased CD4+ T cell counts drive aberrant B cell repertoire alterations in people living with HIV","authors":"Lina Huang ,&nbsp;Xiangyu Zhang ,&nbsp;Yu Shi ,&nbsp;Rishen Liang ,&nbsp;Qianqian Chen ,&nbsp;Jing Yang ,&nbsp;Xiaoni Zhang ,&nbsp;Anning Fang ,&nbsp;Qian Zhang ,&nbsp;Chengchao Ding ,&nbsp;Jiabin Wu ,&nbsp;Jianjun Wu ,&nbsp;Yong Gao","doi":"10.1016/j.antiviral.2025.106236","DOIUrl":"10.1016/j.antiviral.2025.106236","url":null,"abstract":"<div><div>Understanding the evolution of broadly neutralizing antibody (bNAb) activity in people living with HIV is crucial for vaccine design and immunization strategies. It has been proposed that antibody cross-reactive activity is associated with lower CD4⁺ T cell counts during people living with HIV, but the underlying mechanisms remain unclear. To further explore the correlation between antibody reactivity and CD4⁺ T cell counts, we recruited people living with HIV with varying CD4⁺ T cell counts: (i) CD4⁺ T cell ≤50 cells/μL, (ii) 50 cells/μL &lt; CD4⁺ T cell ≤200 cells/μL, (iii) 200 cells/μL &lt; CD4⁺ T cell ≤500 cells/μL, (iv) 500 cells/μL &lt; CD4⁺ T cell. We assessed the antigen-specific antibodies in serum using SOSIP.664 trimers from four different subtypes. Immune repertoire sequencing was used to characterize the B cell receptor (BCR) repertoire of these individuals. The evaluation of antigen-specific antibodies with different SOSIP.664 trimers showed enhanced reactivity in individuals with low CD4⁺ T cell counts compared to those with high/normal CD4⁺ T cell counts. Analysis of antibody gene repertoires through BCR high throughput sequencing revealed an increased proportion of IgG with heavy chain complementarity-determining region 3 (CDRH3) loops exceeding 20 amino acids in individuals with CD4⁺ T cell counts below 50 cells/μL. Notably, the IGHV1-46 and IGHV4-34 germlines, which are suggestive of most polyreactive B cells, were preferentially used in individuals with low CD4⁺ T cell counts. These results suggest that limited engagement of CD4⁺ T cells could facilitate the survival of aberrant B cell repertoire with long CDRH3 regions.</div></div>","PeriodicalId":8259,"journal":{"name":"Antiviral research","volume":"241 ","pages":"Article 106236"},"PeriodicalIF":4.5,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144607247","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":"Mode of antiviral action of the galactose-specific lectin, AJLec, on the Junin virus propagation","authors":"Shuzo Urata ,&nbsp;Meion Lee ,&nbsp;Tomoko Tsuruta ,&nbsp;Reo Igarashi ,&nbsp;Kohsuke Takeda ,&nbsp;Hideaki Unno","doi":"10.1016/j.antiviral.2025.106189","DOIUrl":"10.1016/j.antiviral.2025.106189","url":null,"abstract":"<div><div>Junin virus (JUNV), a member of <em>Arenaviridae</em>, is the causative agent of Argentine hemorrhagic fever (AHF). Available AHF treatments are limited; therefore, development of effective and safe treatments is required. Thus, in this study, novel lectins were examined for anti-JUNV activity. To evaluate JUNV propagation, a recombinant Junin virus vaccine strain (r3Candid #1/ZsGreen) containing the ZsGreen gene as a marker in the viral genome was used. The anti-JUNV effects of four types of marine organism-derived lectins collected in Japan, including the Nagasaki Prefecture, were examined. AJLec, which was extracted from the Sea Anemone <em>Anthopleura japonica</em>, reduced the number of infected cells and viral production. Infection and infection-surrogate assays revealed that incubation of AJLec with viruses and cells before infection, and maintaining it during infection, was required to exhibit full antiviral activity. Moreover, the anti-JUNV activity of AJLec was suppressed by the addition of lactose; hence, the anti-JUNV activity of AJLec was a result of its galactose recognition. This indicates the importance of galactose on the surface of the Junin virion and the cell membrane for entry into cells. Overall, these results provide new insights into the anti-JUNV activity of AJLec. Particularly, the potential of lectins as new antiviral agents that inhibit pathogenic arenavirus replication and propagation is promising.</div></div>","PeriodicalId":8259,"journal":{"name":"Antiviral research","volume":"240 ","pages":"Article 106189"},"PeriodicalIF":4.5,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144092722","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":"A monoclonal antibody targeting conserved regions of pre-fusion protein cross-neutralizes Nipah and Hendra virus variants","authors":"Tao Li ,&nbsp;Hua Xu ,&nbsp;Mengyi Zhang ,&nbsp;Jianhui Nie ,&nbsp;Binfan Liao ,&nbsp;Jingshu Xie ,&nbsp;Yinan Jiang ,&nbsp;Yawen Liu ,&nbsp;Pingju Ge ,&nbsp;Chunhui Zhao ,&nbsp;Ziqi Sun ,&nbsp;Yunbo Bai ,&nbsp;Maoling Tang ,&nbsp;Xiaodong Su ,&nbsp;Youchun Wang ,&nbsp;Weijin Huang","doi":"10.1016/j.antiviral.2025.106215","DOIUrl":"10.1016/j.antiviral.2025.106215","url":null,"abstract":"<div><div>Nipah virus (NiV) and Hendra virus (HeV) have an extremely high case fatality, leading to hundreds of deaths in several countries around the globe. Belonging to the same genus Henipavirus (HNV), the two species have a high degree of sequence similarity, resulting in cross-neutralizing immunity under favorable conditions. Here, we obtained ten anti-NiV-F monoclonal antibodies using hybridoma technology, and verified that these antibodies had potent neutralizing activities against epidemic NiV strains from different regions using a pseudovirus assay, and the neutralizing concentration reached the nanogram per milliliter level. Moreover, two of the antibodies, NiF03-3C9 and NiF03-2F6, were found to have cross-neutralizing activity against HeV, which was even stronger than that against NiV. Epitope competition analysis revealed two classes of epitopes for these antibodies. Cryo-electron microscopy showed that NiF03-3C9 binds to lateral residues of the prefusion F protein trimer, highly conserved in both Nipah and Hendra. The protective potency of the antibodies was also validated using in vivo pseudovirus infection models of Nipah and Hendra viruses. The mAbs developed in this study and their conserved cross-neutralizing epitopes elucidated by structural analysis may contribute to the control of highly pathogenic HNV outbreaks.</div></div>","PeriodicalId":8259,"journal":{"name":"Antiviral research","volume":"240 ","pages":"Article 106215"},"PeriodicalIF":4.5,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144336025","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":"Immunostimulatory effects of multiple short-hairpin RNAs enhance foot-and-mouth disease vaccine-induced humoral immunity","authors":"Aro Kim,&nbsp;Ji-Hyeon Hwang,&nbsp;Gyeongmin Lee,&nbsp;Jong-Hyeon Park,&nbsp;Min Ja Lee,&nbsp;Su-Mi Kim","doi":"10.1016/j.antiviral.2025.106202","DOIUrl":"10.1016/j.antiviral.2025.106202","url":null,"abstract":"<div><div>Small interfering RNAs are typically used to block gene expression via the sequence-specific degradation of mRNA. We previously developed a recombinant adenovirus expressing three short hairpin RNAs, targeting foot-and-mouth disease virus (FMDV) driven by the U6 promoter (Ad-3siRNA). These exhibited rapid antiviral effects against FMDV. Herein, we investigated the immunostimulatory effects of Ad-3siRNA in combination with an FMD inactivated vaccine. Ad-3siRNA induced various cytokines, including type I interferon, and upregulated interferon-stimulated genes in swine cells. Using the combination of Ad-3siRNA and a foot-and-mouth disease (FMD) inactivated vaccine, we observed enhanced protection efficacy until 1 week post-vaccination and enhanced neutralizing antibody levels from 1 week post-vaccination in mice. Furthermore, humoral immunity was significantly enhanced in pigs injected with a vaccine and a combination of Ad-3siRNA for 7 weeks post-vaccination. Ad-3siRNA induced various cytokines, such as IFN-α, IFN-γ, IL-12, IL-6, IL-15 and IL-18, in mice. In conclusion, we demonstrated that Ad-3siRNA, a novel immunostimulatory RNA delivered by a human adenoviral vector, could enhance protection and humoral immunity in combination with an FMD-inactivated vaccine. Exploring the applications of Ad-3siRNAs against other viral diseases and further detailed mechanistic studies are warranted.</div></div>","PeriodicalId":8259,"journal":{"name":"Antiviral research","volume":"240 ","pages":"Article 106202"},"PeriodicalIF":4.5,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144180748","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":"Identifying hypaphorine as a novel antiviral compound against dengue virus","authors":"Shengchen Bai ,&nbsp;Huiru Liang ,&nbsp;Weihao Jiang ,&nbsp;Limei Xu ,&nbsp;Bin Liu ,&nbsp;Tengfei Zhou ,&nbsp;Baoying Chen ,&nbsp;Ruochen Xu ,&nbsp;Zhijun Bai ,&nbsp;Min Liu","doi":"10.1016/j.antiviral.2025.106220","DOIUrl":"10.1016/j.antiviral.2025.106220","url":null,"abstract":"<div><div>Approximately 390 million individuals globally are infected with dengue virus annually. Notably, no specific therapeutic strategy has been clinically approved for dengue fever to date. In this study, molecular docking screening against the methyltransferase (MTase) domain of the dengue virus (DENV) NS5 protein unveiled hypaphorine as a high-affinity ligand, with calculated binding energies of −6.657 kcal/mol (DENV2) and −6.663 kcal/mol (DENV3). This computational prediction was subsequently validated via cellular thermal shift assay (CETSA) and surface plasmon resonance imaging (SPRi), collectively demonstrating direct target engagement with a dissociation constant (KD) of 2.19 × 10⁻⁹ M. Functional characterization revealed that hypaphorine exhibited concentration-dependent inhibition of MTase enzymatic activity (IC₅₀ = 29.9 μM). In antiviral assays, hypaphorine displayed dose-dependent suppression of viral replication in both BHK-21 (IC₅₀ = 18.85 μM) and Huh-7 cells (IC₅₀ = 15.7 μM), while maintaining low cytotoxicity (CC₅₀ = 605.8 μM and 617.3 μM, respectively). Time-course analyses indicated maximal antiviral efficacy when hypaphorine was administered either pre- or post-infection (&lt;24 hpi), which is consistent with the role of MTase in viral RNA capping during successive rounds of virus replication. The reduction in viral titer was found to correlate with MTase inhibition, thereby establishing a clear structure-activity relationship. These findings systematically characterize hypaphorine as a first-in-class natural MTase inhibitor, highlighting the utility of structure-guided approaches in anti-flaviviral drug discovery.</div></div>","PeriodicalId":8259,"journal":{"name":"Antiviral research","volume":"240 ","pages":"Article 106220"},"PeriodicalIF":4.5,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144480346","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}