Antiviral research最新文献

{"title":"Composition, three-dimensional structure and formation mechanism of the foot and mouth disease virus replication complexes","authors":"Bonan Lv ,&nbsp;Xingran Wang ,&nbsp;Ying Zhou ,&nbsp;Zihan Su ,&nbsp;Yidan Sun ,&nbsp;Yingying Yang ,&nbsp;Yang Lu ,&nbsp;Zishu Pan ,&nbsp;Xiao-Feng Tang ,&nbsp;Chao Shen","doi":"10.1016/j.antiviral.2025.106287","DOIUrl":"10.1016/j.antiviral.2025.106287","url":null,"abstract":"<div><div>Positive-sense RNA virus infections induce vesicle formation within host cells to support RNA replication. By extracting and purifying foot-and-mouth disease virus (FMDV) replication complexes and comparing host cells and replication complexes through targeted lipidomics and proteomics analyses, we found that FMDV enriches host cell proteins and polyunsaturated fatty acids in viral replication complexes (VRCs) to facilitate their formation. On the basis of these findings, we propose a model in which VRCs progress from single-membrane vesicles to multi-membrane vesicles (MMVs) during FMDV replication, a process that requires coordinated contributions of host cell proteins and organelle membranes derived from multiple organelles. Our study showed that, as infection advances, FMDV converts single-membrane vesicles (SMVs) into MMVs, which aggregate to expand the surface area of the replication platform and enhance replication efficiency. These membrane structures function in FMDV replication; the endoplasmic reticulum undergoes curling and folding to support VRC assembly. Additionally, some VRCs possess outward-facing openings that permit material exchange. These findings reveal unexpected similarities between FMDV and distantly related positive-strand RNA viruses, suggesting that shared host cellular pathways are exploited to construct membrane-bound replication factories.</div></div>","PeriodicalId":8259,"journal":{"name":"Antiviral research","volume":"244 ","pages":"Article 106287"},"PeriodicalIF":4.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145273387","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":"Repurposed doxepin targeting host AXL kinase to disrupt viral 2C-mediated immune evasion in Coxsackievirus B infection","authors":"Ran Yan ,&nbsp;Qiting Luo ,&nbsp;Xinyi Luo ,&nbsp;Xinrui Zhou ,&nbsp;Jiayi Diao ,&nbsp;Jiapeng Xu ,&nbsp;Wei Ye ,&nbsp;Kai Zheng ,&nbsp;Ge Liu ,&nbsp;Qinchang Zhu","doi":"10.1016/j.antiviral.2025.106307","DOIUrl":"10.1016/j.antiviral.2025.106307","url":null,"abstract":"<div><div>Coxsackievirus B (CVB) infections pose a significant clinical burden due to their association with severe diseases such as myocarditis and aseptic meningitis, and effective antiviral therapies remain an unmet medical need. Here, we investigated the potential of repurposing doxepin hydrochloride (DH), a tricyclic antidepressant, as an antiviral agent against CVB. Our in vitro and in vivo experiments demonstrated that DH significantly inhibits CVB replication. Mechanistically, we elucidated that DH targets the host AXL kinase, thereby inhibiting its phosphorylation of the viral 2C protein at tyrosine 162. This disruption of 2C phosphorylation abrogates CVB-induced suppression of the host IKKβ/NF-κB signaling pathway, leading to the restoration of innate immune responses and enhanced production of pro-inflammatory cytokines IL-1β and IL-6. Furthermore, our findings unveiled a novel immune evasion mechanism employed by CVB, wherein AXL kinase modulates viral replication by regulating host immune signaling. These results highlight AXL as a critical host factor in CVB infection and provide a strong rationale for considering DH as a potential host-targeted therapeutic strategy for CVB-associated diseases, particularly in the absence of specific antiviral agents.</div></div>","PeriodicalId":8259,"journal":{"name":"Antiviral research","volume":"244 ","pages":"Article 106307"},"PeriodicalIF":4.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145457510","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":"Lyophilization enables thermostable formulation of dengue virus-derived defective interfering particles","authors":"Min-Hsuan Lin ,&nbsp;Pramila Maniam ,&nbsp;Bing Tang ,&nbsp;David Harrich","doi":"10.1016/j.antiviral.2025.106308","DOIUrl":"10.1016/j.antiviral.2025.106308","url":null,"abstract":"<div><div>Defective interfering particles (DIPs), containing truncated defective viral genomes (DVGs), are natural byproducts of RNA virus replication with potent antiviral activity. We recently developed a virus-free, dengue virus (DENV)-based platform producing antiviral DIPs with DI290 DVG, termed DIP-DI290. In this study, we established a scalable purification and lyophilization workflow for creating thermostable DIP-DI290 formulations for long-term storage. DIP-DI290 particles were purified via tangential flow filtration and ceramic hydroxyapatite chromatography, then lyophilized and reconstituted for biological assessment. After three months of storage at −80 °C, 4 °C, or room temperature, reconstituted DIP-DI290 retained biological activity, significantly upregulating interferon-stimulated genes (ISGs) and suppressing DENV-2 replication. These findings demonstrate that lyophilization preserves DIP-DI290's antiviral efficacy across diverse storage conditions, supporting its development as a thermostable, field-deployable therapeutic platform for virus infections.</div></div>","PeriodicalId":8259,"journal":{"name":"Antiviral research","volume":"244 ","pages":"Article 106308"},"PeriodicalIF":4.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145487374","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 dual-reporter HCoV-OC43 for coronavirus biology and countermeasure development","authors":"Xiangxue Deng ,&nbsp;Jing Zou ,&nbsp;Zhenjie Liang ,&nbsp;Ping Ren ,&nbsp;Pei-Yong Shi ,&nbsp;Vineet D. Menachery ,&nbsp;Xuping Xie","doi":"10.1016/j.antiviral.2025.106306","DOIUrl":"10.1016/j.antiviral.2025.106306","url":null,"abstract":"<div><div>A reliable experimental system is essential for advancing coronavirus biology and expediting countermeasure development. In this study, we report the construction of an infectious clone of human coronavirus OC43 (HCoV-OC43) using an <em>in vitro</em> ligation strategy. The clone-derived virus faithfully recapitulates the replication characteristics of the parental isolate <em>in vitro</em>. Leveraging this platform, we have developed a dual-reporter virus, OC43-mNG-Nluc, by replacing the viral accessory gene ns2 with a gene cassette encoding both nanoluciferase and fluorescent protein mNeonGreen. This construct enables dual-mode detection via chemiluminescence and fluorescence within a single assay. OC43-mNG-Nluc maintains replication kinetics identical to wild-type HCoV-OC43 in standard immortalized cell lines but exhibits marked attenuation in primary human airway epithelial cultures, underscoring the critical role of ns2 in viral replication within physiologically relevant systems. The dual-reporter virus also demonstrates excellent genetic and phenotypic stability following fifteen passages <em>in vitro</em>. Furthermore, we validate the proof-of-concept utility of OC43-mNG-Nluc in high-throughput antiviral screening, showcasing its advantages in streamlining and facilitating hit identification, triaging, and prioritization. Collectively, this study provides valuable insights into HCoV-OC43 biology and introduces a versatile and robust tool for coronavirus research and therapeutic development.</div></div>","PeriodicalId":8259,"journal":{"name":"Antiviral research","volume":"244 ","pages":"Article 106306"},"PeriodicalIF":4.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145450157","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":"Ensitrelvir suppresses prolonged olfactory abnormalities derived from SARS-CoV-2 infection in hamsters","authors":"Ryoichi Tashima,&nbsp;Takayuki Kuroda,&nbsp;Haruaki Nobori,&nbsp;Satoshi Miyagawa,&nbsp;Takuya Yamane,&nbsp;Alice Shimba,&nbsp;Masaaki Nakashima,&nbsp;Keita Fukao","doi":"10.1016/j.antiviral.2025.106270","DOIUrl":"10.1016/j.antiviral.2025.106270","url":null,"abstract":"<div><div>Ensitrelvir, an oral severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) 3CL protease inhibitor, is reportedly effective in suppressing smell disorder onset, a post-coronavirus disease 2019 (COVID-19) condition symptom. However, the pathogenesis of post-COVID-19 condition symptoms and the mechanism underlying the onset-suppressive effect of ensitrelvir are not fully understood. Here, we explored a post-COVID-19 condition model in hamsters 1 month post-SARS-CoV-2 infection and showed that ensitrelvir treatment caused early recovery of body weight, viral RNA suppression, and sense of smell improvement. In the nasal turbinates, SARS-CoV-2 was associated with significantly increased inflammatory markers, many of which were suppressed by ensitrelvir. Significant positive correlations were observed between smell testing and many inflammation-related markers in the nasal turbinates. In conclusion, our study indicates that chronic inflammation may occur in the nasal turbinates over a long period post-SARS-CoV-2 infection, leading to smell disorder onset in a hamster model. Early ensitrelvir treatment post-infection suppressed inflammation in the nasal turbinates and prevented smell disorder onset.</div></div>","PeriodicalId":8259,"journal":{"name":"Antiviral research","volume":"243 ","pages":"Article 106270"},"PeriodicalIF":4.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144999576","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":"Small molecule direct-acting antivirals for treatment of mpox","authors":"E. Randall Lanier,&nbsp;Richard L. Mackman,&nbsp;Lee Ruggiero,&nbsp;James F. Demarest,&nbsp;John C. Pottage Jr.,&nbsp;INTREPID Alliance Scientific Working Group","doi":"10.1016/j.antiviral.2025.106285","DOIUrl":"10.1016/j.antiviral.2025.106285","url":null,"abstract":"<div><div>In 2022 and 2024, outbreaks of mpox disease caused by two different clades of MPXV resulted in the World Health Organization (WHO) declaring two public health emergencies of international concern (PHEIC). Different clades/subclades/lineages of MPXV can have substantially different pathogenicity and transmission characteristics. The recent rapid spread of mpox disease, evidence for evolution of MPXV during sustained human-human transmission, challenges associated with MPXV vaccination, and disappointing results from two Phase 3 trials of a promising antiviral (tecovirimat) highlight an urgent unmet need for mpox treatments. This review assesses the current landscape of small molecule direct acting antivirals (DAAs) for mpox in the context of potential pandemic threats from ORPVs. Despite many reports of compounds with antiviral activity against MPXV and other ORPVs in vitro, none have proven effective so far in controlled clinical human studies. To address this gap, tecovirimat is undergoing further testing in Phase 3 trials for mpox, as is a second small molecule DAA (brincidofovir), both approved by national regulatory agencies (e.g., U.S. FDA) for the treatment of smallpox based on efficacy in animal models. Additional DAAs for treatment of mpox are in early development, highlighting a major gap in medical countermeasures. Compound characteristics are identified that should increase the probability of clinical success and durability for mpox and improve the likelihood that they will also be effective against other ORPVs.</div></div>","PeriodicalId":8259,"journal":{"name":"Antiviral research","volume":"243 ","pages":"Article 106285"},"PeriodicalIF":4.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145211510","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":"Intranasal vaccine induces broad and long-lasting immunity against the hemagglutinin stem of group 2 influenza A viruses","authors":"Wanyue Zhang ,&nbsp;Jérémie Prévost ,&nbsp;Angela Sloan ,&nbsp;Levi Tamming ,&nbsp;Annabelle Pfeifle ,&nbsp;Caroline Gravel ,&nbsp;Sathya N. Thulasi Raman ,&nbsp;Gary Van Domselaar ,&nbsp;Michael J.W. Johnston ,&nbsp;Lisheng Wang ,&nbsp;Simon Sauve ,&nbsp;Michael Rosu-Myles ,&nbsp;Darwyn Kobasa ,&nbsp;Anh Tran ,&nbsp;Wangxue Chen ,&nbsp;Xu Zhang ,&nbsp;David Safronetz ,&nbsp;Xuguang Li","doi":"10.1016/j.antiviral.2025.106284","DOIUrl":"10.1016/j.antiviral.2025.106284","url":null,"abstract":"<div><div>Influenza A viruses are categorized into two phylogenetic groups (group 1 and group 2) based on the structure of their hemagglutinin (HA) protein. Within group 2, H3N2 poses a particular challenge due to its rapid evolution, limited vaccine efficacy, and association with more severe influenza seasons. Although T cell responses have been extensively studied in the context of vaccine-induced protection, HA stem (HA2)-specific T cell responses have been relatively understudied, especially those related to nasal immunity. To address this, we engineered an adenoviral vector vaccine (Ad-HA2) expressing a consensus hemagglutinin stem sequence, derived through bioinformatic analysis of all H3 strains. The vaccine conferred heterosubtypic protection against lethal challenges with either H3N2 or H7N9, both belonging to group 2 influenza A viruses, with protection lasting at least six months post-vaccination. Notably, the vaccine induced robust HA2-specific humoral and cell-mediated responses in the nasal-associated lymphoid tissue (NALT) of the upper respiratory tract, the first line of immune defense against inhaled pathogens. The vaccine also elicited significant levels of antibodies and T cell responses in the lower respiratory tract and pulmonary immune sites. Furthermore, circulating antibodies in the serum demonstrated effective antibody-dependent cellular cytotoxicity (ADCC) activity. Finally, using a peptide pool matrix screening approach combined with <em>in silico</em> verification, we identified an immunogenic C-terminus region of the HA2 consensus sequence that activated CD4⁺ and CD8⁺ T cells, which warrants further investigation. Collectively, these findings are informative for the design and evaluation of mucosal influenza vaccines targeting the hemagglutinin stem.</div></div>","PeriodicalId":8259,"journal":{"name":"Antiviral research","volume":"243 ","pages":"Article 106284"},"PeriodicalIF":4.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145181936","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":"Efficient eukaryotic expression and potent antiviral activity of a long-acting recombinant feline interferon-ω2-Fc fusion protein against major feline viruses","authors":"Yuwei Yang ,&nbsp;Hetao Song ,&nbsp;Ke Zhang ,&nbsp;Siyin Wang ,&nbsp;Ya Zhao ,&nbsp;Qiang Zhang ,&nbsp;Meilin Jin","doi":"10.1016/j.antiviral.2025.106272","DOIUrl":"10.1016/j.antiviral.2025.106272","url":null,"abstract":"<div><div>Feline interferon-ω2 (FeIFN-ω2) holds potential as a therapeutic agent against feline viral infections. However, its clinical application is limited by rapid clearance and suboptimal antiviral effectiveness. Thus, in this study, an Fc-fused construct, FeIFN-ω2-Fc, was engineered to improve antiviral potency and pharmacokinetic properties both <em>in vitro</em> and in vivo. Three recombinant constructs—native FeIFN-ω2, FeIFN-ω2-Dimer, and FeIFN-ω2-Fc—were expressed in Chinese Hamster Ovary cells. All showed strong antiviral activity (10^6.74–10^8.42 IU/mg) and effectively activated downstream interferon signaling. Functional assays, including 50 % tissue culture infectious dose assay, quantitative polymerase chain reaction, and immunofluorescence, confirmed their ability to inhibit feline calicivirus (FCV), feline herpesvirus type 1 (FHV-1), and feline parvovirus (FPV). Glycosylation analysis revealed two sites (S102 and T128) in the ω2 domain of FeIFN-ω2-Fc that contributed to its structural stability and functional enhancement. Among the three candidates, FeIFN-ω2-Fc demonstrated the best overall profile, with higher expression levels, simplified purification, and favorable pharmacokinetics. In animal models, it was well tolerated and significantly alleviated clinical symptoms, reduced viral loads, and preserved tissue integrity following FHV-1 infection. Pharmacokinetic studies showed a marked increase in plasma half-life, from 5.80 ± 1.75 h for the native protein to 34.05 ± 6.36 h for the Fc-fused form. Further extension to 40.55 ± 6.61 h was achieved by introducing YTE mutations (S250Y/S252T/T254E) within the Fc region. Based on these findings, a dosing regimen of 4 × 10⁵ IU/kg every other day is proposed, supporting FeIFN-ω2-Fc as a strong candidate for feline antiviral therapy.</div></div>","PeriodicalId":8259,"journal":{"name":"Antiviral research","volume":"243 ","pages":"Article 106272"},"PeriodicalIF":4.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005891","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":"Ubiquitinated hepatitis D antigen-induced CD8+ T-cell responses inhibit HDV replication in HDV-infected liver organoids","authors":"Leer Shen ,&nbsp;Luying Tian ,&nbsp;Qingxin Guo ,&nbsp;Rongli He ,&nbsp;Yi Zhang ,&nbsp;Siyuan Ma ,&nbsp;Weiwei Hu ,&nbsp;Jie Chen ,&nbsp;Soon Seng Ng ,&nbsp;Jinmei Chen ,&nbsp;Xiaohua Chen","doi":"10.1016/j.antiviral.2025.106266","DOIUrl":"10.1016/j.antiviral.2025.106266","url":null,"abstract":"<div><h3>Background</h3><div>Hepatitis D virus (HDV) infection is the most severe form of human viral hepatitis. A poor virus-specific CD8⁺T cell response may result in persistent HDV infection. We investigated anti-viral effect and mechanisms of ubiquitinated small hepatitis D antigen (Ub-S-HDAg) in HBV/HDV superinfected liver organoids.</div></div><div><h3>Methods</h3><div>Induced pluripotent stem cells were differentiated into hepatocyte-like cells and seeded onto inverted colloidal crystal scaffolds. A Ub-S-HDAg recombinant lentiviral plasmid was constructed and transduced into dendritic cells (DCs), which were then co-cultured with T cells. Cytokine levels secreted by CD8⁺T cells and their antiviral efficacy were evaluated, and transcriptomic sequencing was conducted to elucidate immunoregulatory mechanisms of Ub-S-HDAg.</div></div><div><h3>Results</h3><div>We successfully established a model that stably expressed HDV. Ub-S-HDAg significantly promoted DC maturation and reduced HDV RNA viral load and HDAg levels. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis and gene set enrichment analyses suggested that DCs transduced with Ub-S-HDAg promoted CD8⁺ T cell activation via Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway. JAK1, JAK2, STAT1, and STAT4 expressions in Ub-S-HDAg group increased and was blocked by JAK2 inhibitor AG490. Additionally, Ub-S-HDAg induced DC maturation-enhanced cytotoxic T lymphocyte responses and increased IFN-γ, IL-2, IL-12, and TNF-α secretion.</div></div><div><h3>Conclusion</h3><div>We successfully developed HBV/HDV superinfected liver organoids and suggest that Ub-S-HDAg facilitates DC maturation, inducing CD8⁺ T cell proliferation through the JAK/STAT signalling pathway, leading to a stronger antiviral immune response.</div></div>","PeriodicalId":8259,"journal":{"name":"Antiviral research","volume":"243 ","pages":"Article 106266"},"PeriodicalIF":4.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144989912","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":"Remarkable photodynamic activity of tetra-cationic porphyrins against Vaccinia virus and Monkeypox virus","authors":"Gilneia da Rosa ,&nbsp;Paulo Henrique Hümmelgen Silva ,&nbsp;José Valter Joaquim Silva Júnior ,&nbsp;Micheli Mainardi Pillat ,&nbsp;Bernardo Almeida Iglesias ,&nbsp;Rudi Weiblen ,&nbsp;Eduardo Furtado Flores","doi":"10.1016/j.antiviral.2025.106279","DOIUrl":"10.1016/j.antiviral.2025.106279","url":null,"abstract":"<div><div>In this context, we evaluated the photodynamic effects of four cationic tetra-(pyridyl)porphyrins against Vaccinia virus Western Reserve (VACV WR) and Monkeypox virus (MPXV). The porphyrins were initially analyzed for cytotoxicity to Vero cells by MTT assay and the maximal non-cytotoxic concentrations were used in virucidal assays. For virucidal assays, VACV-WR (107.5 TCID50/mL) and MPXV suspensions (106.97 TCID50/mL) were incubated with porphyrins, exposed (or not) to white light conditions at 45 min. Aliquots of virus suspensions were collected and quantitated, comparing the titers with those of virus suspensions not exposed to porphyrins and/or to light. Porphyrins <strong>4-PtTPyP</strong>, <strong>3-H₂TMeP</strong> and <strong>4-H₂TMeP</strong> exhibited light-dependent activity and completely inactivated VACV-WR and MPXV after 5, 30 and 45 min of light exposure, respectively. In contrast, derivative 3-PtTPyP inactivated the viruses even in the absence of white light exposure, a light-independent virucidal activity. Virucidal assays were performed in the presence/absence of ROS scavengers. Ascorbic acid (AA) was the only capable of completely inhibiting photodynamic inactivation by the three porphyrins. This indicates a type II photodynamic mechanism by singlet oxygen (¹O₂). These results demonstrated photodynamic inactivation of poxviruses by tetra-cationic porphyrins, supporting their potential use - especially <strong>4-PtTPyP</strong> – for virus inactivation in many applications. These results also pave the way for testing porphyrin in PDT of poxvirus-induced cutaneous lesions. In addition, our data validated the use of VACV as a <em>in vitro</em> model for targeted MPXV virucidal testing.</div></div>","PeriodicalId":8259,"journal":{"name":"Antiviral research","volume":"243 ","pages":"Article 106279"},"PeriodicalIF":4.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145004674","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}