Immune and protective effects of recombinant multi-epitopes vaccine against infectious spleen and kidney necrosis virus in pearl gentian grouper (♀Epinephelus fuscoguttatus × ♂Epinephelus lanceolatus).

Identification of the biological properties of three novel lytic bacteriophages capable of infecting Bacillus anthracis: Novel members of the class Caudoviricetes.

RNA 5-methylcytosine (m5C) plays an undefined role in plant antiviral defense. Here, we reveal that the wheat methyltransferase NOP2/Sun RNA methyltransferase 2 (TaNSUN2) is an RNA m5C methyltransferase recruited by eukaryotic elongation factor 1-alpha (TaeEF1A) into Chinese wheat mosaic virus (CWMV) replication complexes (VRCs). TaNSUN2 promotes the m5C modification of CWMV RNAs to stabilize them and enhance their translational efficiency. Moreover, m5C modification in RNA 3′ untranslated region strengthens both TaeEF1A binding, promoting viral replication, and viral coat protein interaction, facilitating viral assembly. A major allele of TaNSUN2 prevents its interaction with TaeEF1A and hinders its entry into the VRCs to suppress m5C modification of viral RNAs. TaNSUN2 knockout enhances wheat resistance to CWMV and increases the weight and size of wheat grains. Our findings provide mechanistic insights into the function of RNA modifications in plant virus infection and a valuable genetic resource for future wheat breeding projects.

Cypoviruses are insect-specific, double-stranded RNA viruses belonging to the genus Cypovirus within the family Spinareoviridae. Cypoviruses primarily infect insects of the orders Lepidoptera, Diptera, and Hymenoptera. These viruses replicate in midgut epithelial cells, forming polyhedrin-based occlusion bodies. Cypovirus genomes typically consist of 10-16 linear double-stranded RNA (dsRNA) segments that encodes distinct viral proteins; however, the number of genomic segments may vary among species. Each genomic segment encodes a functionally specialized distinct viral protein, with high intra-species conservation but notable divergence between species, reflecting genomic plasticity and evolutionary divergence. This review presents a comprehensive comparative genomic analysis of representative Cypovirus species, focusing on segment-wise assignments. Segment 1 universally encodes the major capsid protein, while segment 2 encodes the RNA-dependent RNA polymerase (RdRP) and segment 3 encodes the minor capsid protein. Segments 4 and 5 typically encode enzymes with methyltransferase and guanylyl transferase, which are essential for RNA capping. Segments 6 to 8 encodes for other structural or accessory proteins. Segment 9 frequently encodes a non-structural protein and segment 10 consistently encodes structural polyhedrin protein. Conserved protein domains and sequence motifs are identified across cypovirus genomic segments. Analysis of nonsynonymous to synonymous substitutions (Ka/Ks ratios) reveals evidence of both purifying and positive selection in viral genomic segments. Phylogenetic analysis demonstrates lineage diversification and species-specific clustering. Genotypic and phenotypic variability among viral strains correlates with host insect species, co-infection and geographic isolation, whereas functional convergence in protein roles is observed across species. This study consolidates electrophoretic migration patterns and genomic demarcation criteria for Cypovirus species into a practical reference framework that enables rapid species identification without the need for complete genome sequencing. The current review provides structural, genomic, and evolutionary insights that collectively advance the current understanding of cypovirus biology and diversity.

Innovative MgCl2 -mediated two-step precipitation-dissolution strategy for efficient purification of Porcine Circovirus Type 2 capsid protein and self-assembly of virus-like particles.

Bluetongue (BT) is a WOAH-notifiable economically important disease of ruminants caused by Bluetongue virus (BTV), transmitted by Culicoides spp. biting midges. Over the past two years, Italy has experienced a marked re-emergence of BT, with thousands of outbreaks reported due to the simultaneous circulation of several BTV strains belonging to serotypes 3, 4, and 8. Moreover, in September 2025, BTV-5 was detected in Sardinia, marking its first occurrence in Europe. Following the first identification by Whole Genome Sequencing, the development of a reliable real-time RT-qPCR-based assay capable of typing the novel BTV-5 ITA 2025 strain was essential, as currently available molecular typing methods targeting BTV segment 2, which encodes the outer capsid protein VP2, are unable to detect this newly emerging strain. Therefore, in this study we developed, optimised, and validated a real-time RT-PCR assay for the detection and typing of BTV-5 ITA 2025 in field samples. The assay is characterised by high sensitivity and specificity, as well as good reproducibility, and can be effectively applied for BTV-5 ITA 2025 diagnosis in the current epidemiological context, supporting surveillance and control strategies.

The HIV-1 capsid is a fullerene cone composed of hexameric and pentameric capsid proteins (CA) that packages the viral genome and mediates nuclear entry. Lenacapavir (LEN), a potent molecular long-acting inhibitor developed by Gilead, disrupts capsid morphogenesis by binding a phenylalanine-glycine (FG) pocket at the interface between adjacent CA subunits. Interestingly, cellular polyanion inositol hexakisphosphate (IP6) promotes conical capsid assembly by coordinating the central pore, which is allosterically coupled to the FG pocket. Because LEN and IP6 engage overlapping structural elements, they can compete to influence the capsid assembly pathway and outcomes. Using coarse-grained molecular simulations, we show that LEN accelerates hexamer formation while suppressing pentamer incorporation, yielding malformed, multilayered, and incomplete capsids. Simulations incorporating a ribonucleoprotein model further reveal that LEN-treated capsids often fail to encapsulate RNA, indicating impaired maturation. Our calculations confirm that LEN impairs the formation of high-curvature CA lattice regions necessary for closure, supporting a model of off-pathway assembly as a mechanism of viral inhibition. These findings define the core mechanism by which a small-molecule inhibitor disrupts the much larger-scale HIV-1 morphogenesis and underscore general principles for targeting self-assembling multi-protein complexes.

Cultivation of passion fruit (Passiflora edulis) is significantly impacted by East Asian Passiflora virus (EAPV). This study investigates the antiviral potential of the natural flavonoid dihydromyricetin (DHM) in targeting the EAPV coat protein (CP). Molecular docking analyses revealed that DHM exhibits a strong affinity for EAPV-CP, a finding corroborated by microscale thermophoresis (KD = 3.48 ± 2.18 μM). In vivo experiments demonstrated that DHM treatment resulted in a reduction of CP transcription by up to 16-fold in tobacco leaves and 2-fold in passion fruit leaves after 18 days. Transcriptomic analysis indicated that DHM application significantly modified host gene expression, particularly through the upregulation of differentially expressed genes associated with flavonoid biosynthesis and plant defense signaling pathways. Metabolomic profiling revealed an enrichment of flavonoid-related metabolites. Furthermore, an integrative analysis identified three gene modules that exhibited strong correlations with flavonoid metabolism. These findings suggest that DHM inhibits EAPV by targeting the viral coat protein and enhancing the host-derived flavonoid-induced resistance. Consequently, DHM emerges as a novel and sustainable antiviral agent for managing Potyvirus infections in agricultural crops.

Integrative bioinformatics approach to the mRNA vaccine development for the human papillomavirus using the capsid protein.

Insights into red sea bream iridovirus pathogenesis: Unveiling host-pathogen interactions using membrane yeast two-hybrid and molecular dynamics.

Production and characterization of norovirus virus-like particles vaccine candidates in a genetically modified Ogataea minuta system.

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is an antibody-mediated inflammatory disorder of the central nervous system, which is characterized by demyelination targeting the optic nerve, brain, and spinal cord. The etiology of MOGAD still remains to be elucidated. Here we performed a retrospective study comparing virus antibody levels of monophasic MOGAD patients to relapsing-remitting multiple sclerosis patients (RRMS) and healthy controls (HCs). We enrolled 19 patients with monophasic MOGAD (F:M 13:6, mean 41 years) and 30 patients with RRMS (F:M 21:9, mean 41 years) referred to the Department of Neurology at Rigshospitalet Glostrup, Denmark. Moreover, 15 HCs (F:M 8:7, mean 43 years) were included. Patients and HCs were matched according to age and gender when possible. Antibody levels to Epstein-Barr virus (EBV) Epstein-Barr nuclear antigen (EBNA)1, human herpes virus (HHV) 6A polymerase processivity factor, John Cunningham virus (JCV) major capsid protein 1, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein and cytomegalovirus (CMV) phosphoprotein 52 were measured by enzyme-linked immunosorbent assay. No differences in antibody levels to HHV6, CMV, and JCV proteins were observed between MOGAD patients and HCs. Similarly, no significant differences in antibody levels to SARS-CoV-2, HHV6, CMV, and JCV were found between MOGAD patients and RRMS patients. However, RRMS patients presented with significantly increased EBV EBNA1 IgG levels in when compared to MOGAD patients and HCs. Our findings suggest that development of MOGAD is neither associated with SARS-CoV-2, HHV6, CMV nor JCV alone. Furthermore, results presented indicate that EBV serology is different in MOGAD patients compared to RRMS, confirming a role of EBV in the development of MS and suggesting that the etiology of MOGAD is different from MS.

Human adenoviruses (HAdVs) are enjoying a renaissance in interest for the development of cancer therapies following the approval of Adstiladrin (Ferring Pharmaceuticals) for the treatment of bladder cancer, strong phase 3 data from CG Oncology's cretostimogene grenadenorepvec, and many other products in late-stage clinical development. Most therapeutic oncolytic HAdV (oHAdV)-based vectors are engineered to enhance their natural selectivity for human cancer cells and/or to alter their capsid proteins to bias their tropism toward cancer tissues. Furthermore, modern therapeutic oHAdV-based vectors often include transgenes encoding potent immunotherapies. These transgenes have the potential to overcome the relatively modest efficacy that has been observed for non-transgene-bearing viruses, which rely on direct oncolysis of virally infected tumor cells. These modifications, and the highly complex interactions that occur between oHAdVs and the host, make it particularly challenging to develop relevant animal models to investigate acute toxicity, immunity, efficacy, and pharmacodynamics for pre-clinical development of these agents. Here, the experimental options for pre-clinical evaluation of therapeutic oHAdV-based vectors for cancer therapy are reviewed, with a focus on Ad serotype 5 (Ad5), the most common serotype for therapeutic oHAdV-based vector development.

The fusion of newly formed early endosomal vesicles after endocytosis is a crucial step in viral infection. It facilitates the transition of many viruses from viral internalization to downstream intracellular trafficking within the endosomal network, ultimately enabling their delivery to intracellular replication sites. Despite its significance, the molecular mechanisms regulating the fusion of these vesicles remain poorly understood. In this study, we show that Rabankyrin-5, a Rab5 effector, is essential for the fusion of human papillomavirus (HPV)-carrying early endosomes during viral entry. Additionally, Rabankyrin-5 acts as a dynein adaptor, directly binding both the HPV minor capsid protein L2 and the dynein motor complex to link virus-carrying early endosomes to the dynein transport machinery, thereby promoting virus movement along microtubules. These dual functions enable the coordinated integration of endosomal fusion with microtubule-based transport during the early stages of viral entry.

Largemouth bass virus (LMBV), a member of the Ranavirus genus within the Iridoviridae family, is a significant pathogen causing high mortality and substantial economic losses in largemouth bass aquaculture. Therefore, developing effective antiviral agents against this viral infection is crucial for the largemouth bass aquaculture industry. Quercetin, a widely utilised flavonoid known for its therapeutic and prophylactic properties, was investigated for its antiviral efficacy against LMBV and underlying mechanisms in this study. The results demonstrated that quercetin significantly inhibited LMBV propagation invitro and invivo, and was effective in both prevention and treatment stages. Specifically, quercetin at 6.25 μg/mL suppressed LMBV (major capsid protein) MCP gene transcription by up to 92.09%, with the post-infection treatment achieving 99.33% inhibition invitro. Mechanistic studies revealed that quercetin reduces LMBV infectivity by disrupting viral internalisation and replication, while also potentiating cellular immune responses mediated by the IFN system. Invivo experiments further confirmed that quercetin treatment reduced viral transcription in the liver, spleen and kidney by 97.49%, 47.45% and 98.42%, respectively, at 48 h post-infection and significantly enhanced the survival rate of infected juveniles. In conclusion, quercetin demonstrated potent antiviral activity against LMBV and might serve as a promising, eco-friendly antiviral agent.

Precise packaging of diverse cargo within self-assembling protein cages of defined size and shape is essential for many biotechnological applications, yet cellular expression offers limited control over loading. Here, we developed an in vitro cargo-directed reconstitution system of a split, artificial nucleocapsid (spNC-4). Two spNC-4 capsid protein subunits were prepared independently and assembled with cargos cooperatively. As an authentic cargo, a nucleocapsid mRNA is packaged into a 30 nm-spheric nucleocapsid in vitro, closely matching to spNC-4 expressed in cells. In this system, a diverse range of cargos are encapsulated, including noncognate RNA, RNA-positively supercharged fluorescent protein complex, and linear double-stranded DNA. Moreover, by packaging 30 nm-spherical or rod-shaped DNA origamis as templates, the nucleocapsid morphology was altered to an enlarged 60 nm-spherical structure or rod-shaped structure. The developed system accepts versatile composition and programmable control over the artificial nucleocapsid architecture, creating a general platform for enzyme nanoreactors, targeted delivery, and vaccine development.

Potato virus X (PVX) and potato virus Y (PVY) are major pathogens that threaten seed potato quality and yield. To improve the efficiency of field screening, we developed monovalent PVX, monovalent PVY, and bivalent PVX/PVY nanozyme strips using Fe3O4 nanozymes as labels in a double-antibody sandwich lateral flow immunochromatographic assay. Western blot analysis demonstrated that four monoclonal antibodies (PVX 2, PVX 6, PVY 2, and PVY 5) specifically recognized their corresponding viral coat proteins. Specificity testing showed that the nanozyme strips reacted only with the target viruses and did not cross-react with other common potato viruses, including Potato virus A (PVA), Potato virus M (PVM), Potato virus S (PVS), and Potato leafroll virus (PLRV). The PVX nanozyme strip detected PVX-positive extracts diluted up to 103-fold, the PVY nanozyme strip up to 104-fold, and the bivalent strip detected PVX/PVY co-infected samples diluted up to 103-fold. In addition, detection results by strips from 12 samples of plantlets in vitro were fully consistent with RT-PCR. These nanozyme strips provide rapid, simple, specific, and sensitive methods that can be stored at ambient temperature, enabling field surveys, warehouse screening, and on-site testing and supporting early detection of potato virus diseases.

Infectious diseases have become a major challenge in global tilapia aquaculture. This study investigated disease outbreaks affecting red hybrid tilapia (Oreochromis spp.) by collecting 80 pooled samples from 36 farms between 2022 and 2024. Although the majority of samples tested positive for tilapia lake virus (TiLV), infectious spleen and kidney necrosis virus (ISKNV) was detected in 10% of the cases, specifically in fry and fingerlings originating from river-based cage systems. All the ISKNV-positive cases involved coinfections with TiLV, bacteria, and ectoparasites. Megalocytes with basophilic intracytoplasmic inclusion bodies were detected along with hemosiderin deposits in the anterior kidneys and spleens of the ISKNV-positive fish. ISKNV was confirmed by PCR and insitu hybridization. The virus was successfully isolated in red hybrid tilapia brain (RHTiB) cells, showing cytopathic effects within 2-5 days postinfection. Phylogenetic analysis of the major capsid protein gene clustered the Thai isolate within ISKNV Clade 1, related to other Asian strains. Our findings highlight the need to include ISKNV in routine diagnostic surveillance and the importance of implementing integrated health management strategies focused on the early life stages of fish in intensive tilapia production systems.

Hepatitis E virus (HEV) is a major zoonotic pathogen, and pigs are an important reservoir. Serology for anti-HEV antibodies poorly reflects active infection, while reverse transcription polymerase chain reaction (RT-PCR) is sensitive but not always feasible for large-scale surveillance. This study aimed to develop an immunoglobulin Y (IgY)-based sandwich enzyme-linked immunosorbent assay (ELISA) for direct detection of HEV antigen (HEV-Ag). An antigenic epitope from the HEV open reading frame 2 capsid protein was identified in silico, synthesized, and used to immunize laying hens; IgY was purified from egg yolk and characterized by sodium dodecyl sulfate–polyacrylamide gel electrophoresis. An in-house sandwich ELISA was subsequently developed using the anti-HEV IgY antibodies. Its diagnostic performance was evaluated against RT-PCR using 350 field-collected pig serum samples and compared with commercial anti-HEV IgG and IgM ELISA kits. Immunization yielded high-purity IgY antibodies, with antigen-specific antibody kinetics showing a significant increase in specific immunoreactivity from week 4 onward and peak sensitivity at weeks 6–8 post-immunization. The anti-HEV IgY showed high specificity, with no cross-reactivity observed against a heterologous antigen (HBsAg). The optimized sandwich ELISA detected HEV-Ag with a sensitivity of 95.4% and a specificity of 100% relative to RT-PCR. The prevalence of HEV-Ag was 17.7% (62/350), which was not significantly different from RT-PCR (18.6%, 65/350; p=0.250). In contrast, commercial IgG and IgM ELISAs showed high seroprevalence rates (34.9% and 28.3%, respectively) but exhibited significant discrepancies with RT-PCR (p<0.0001), indicating limited utility for identifying active infection. Overall, the developed IgY-based sandwich ELISA demonstrated high diagnostic performance for detecting active HEV infection. This assay represents a viable alternative to RT-PCR for large-scale surveillance, particularly in resource-constrained settings, and may contribute to improved control of zoonotic HEV transmission.

Foot-and-mouth disease virus (FMDV) is a highly contagious pathogen of cloven-hoofed livestock. Recombination is one of the mechanisms that contribute to genetic diversity of FMDV and facilitate the generation of new viral lineages, or recombinant forms. While the general patterns of recombination in FMDV are well-known, the temporal dynamics of this process remain unexplored. This study systematically analyzed recombination across 1485 publicly available complete genome sequences of FMDV, collected from 1934 to 2024. In addition to the well-known general recombination pattern with hotspots on the borders of the genome region that encodes capsid proteins VP2-VP3-VP1, we identified serotype-specific recombination patterns. A significant temporal signal required to analyze temporal dynamics was found in serotypes A, Asia1, O, and SAT1 in the VP2-VP3-VP1 genome region. To assess the lifetimes of FMDV recombinant forms, we compared these time-scaled phylogenetic trees with phylogenies for other genomic regions exchanged by recombination events. The median lifetimes of FMDV recombinant forms ranged from 2 to 18 years, depending on the serotype and the nonstructural genomic region involved in recombination. These timescales are comparable to human (+)RNA viruses, such as enteroviruses and caliciviruses. In distinct serotypes, recombination could be more frequent on the 5' or 3' border of the capsid-encoding genome region, without a uniform pattern.