Search Results (395)

Porcine reproductive and respiratory syndrome virus (PRRSV), an enveloped single-stranded positive-sense RNA virus, poses a significant threat to global swine production. Despite the availability of modified live virus and inactivated vaccines, their limited efficacy and safety concerns highlight the urgent need for novel antiviral therapeutics. This study aimed to investigate the molecular mechanisms by which lycopene inhibits PRRSV replication. Initial assessments confirmed that lycopene did not adversely affect cellular viability, cell cycle progression, or apoptosis. Using fluorescence microscopy, flow cytometry, immunoblotting, quantitative real-time PCR (qRT-PCR), and viral titration assays, lycopene was shown to exhibit potent antiviral activity against PRRSV. Mechanistic studies revealed that lycopene suppresses reactive oxygen species (ROS) production, which is critical for PRRSV proliferation. Additionally, lycopene attenuated PRRSV-induced inflammatory responses, as demonstrated by immunoblotting, ELISA, and qRT-PCR assays. These findings suggest that lycopene inhibits PRRSV replication by modulating ROS levels and mitigating inflammation, offering a promising avenue for the development of antiviral therapeutics. This study provides new insights and strategies for combating PRRSV infections, emphasizing the potential of lycopene as a safe and effective antiviral agent. Full article

Saffron (Crocus sativus L.) is a vegetatively propagated crop of high economic and cultural value, potentially affected by viral infections that may impact its productivity. Despite Iran’s dominance in global saffron production, knowledge of its virome remains limited. In this study, we conducted the first nationwide virome survey of saffron in Iran employing a high-throughput sequencing (HTS) approach on pooled samples obtained from eleven provinces in Iran and one location in Afghanistan. Members of three virus families were detected—Potyviridae (Potyvirus), Solemoviridae (Polerovirus), and Geminiviridae (Mastrevirus)—as well as one satellite from the family Alphasatellitidae (Clecrusatellite). A novel Potyvirus, tentatively named saffron Iran virus (SaIRV) and detected in three provinces, shares less than 68% nucleotide identity with known Potyvirus species, thus meeting the ICTV criteria for designation as a new species. Genetic diversity analyses revealed substantial intrapopulation SNP variation but no clear geographical clustering. Among the two wild Crocus species sampled, only Crocus speciosus harbored turnip mosaic virus. Virome network and phylogenetic analyses confirmed widespread viral circulation likely driven by corm-mediated propagation. Our findings highlight the need for targeted certification programs and biological characterization of key viruses to mitigate potential impacts on saffron yield and quality. Full article

A virome survey of banana plantations and their surrounding plants was carried out at nation-wide level in Malawi using virion associated nucleic acids (VANA) high throughput sequencing (HTS) on pooled samples and appropriate alien controls. In total, 366 plants were sequenced, and 23 plant virus species were detected, three species on banana (275 plants) and 20 species in surrounding plants (91 plants). Two putative novel virus species; ginger tymo-like virus and pepper derived totivirus were detected and confirmed by RT-PCR on ginger and pepper. Nine known virus species and detected a host plant was identified for two of them. No viral exchange between banana and surrounding plants was observed. Results from the VANA protocol, applied to pooled banana samples, were compared with previous targeted PCR results obtained from individual banana samples. HTS test detected better BanMMV than IC-(RT)-PCR on individual samples (better inclusivity) but detected with much lower sensitivity BBTV and BSV species, often with less than 10 reads per sample. Detection of novel and known viruses and new host plants calls for strengthened sanitory and phytosanitory measures within and beyond banana production systems. Our research confirms that HTS sensitivity depends on sampling, pooling protocol and targeted virus species. Full article

Coronaviruses, particularly those classified as highly pathogenic species, pose a significant threat to global health. These viruses hijack host cellular membranes and proteins to facilitate their replication, primarily through the formation of replication organelles (ROs). However, the precise regulatory mechanisms underlying RO formation remain poorly understood. To elucidate these mechanisms, we conducted mass spectrometry analyses, identifying interactions between the host protein DnaJ homolog subfamily C member 11 (DNAJC11) and the SARS-CoV-2 nonstructural protein 3 (NSP3) protein. Notably, results showed that DNAJC11 depletion reduces SARS-CoV-2 infection, indicating possible positive regulatory involvement. But the ectopic expression of DNAJC11 did not lead to marked alterations in immune or inflammatory responses. DNAJC11 enhanced NSP3 expression stability through endogenous apoptosis pathways and facilitated its interaction with NSP4, thereby promoting the formation of double-membrane vesicles (DMVs). Knockdown of DNAJC11 reduced DMV number and size, accompanied by dysregulation of the endoplasmic reticulum and mitochondria. However, supplementation with DNAJC11 restored both DMV number and size. These findings provide novel insights into the role of DNAJC11 as a host factor that modulates DMV formation and supports SARS-CoV-2 replication by targeting the NSP3 protein. This study advances our understanding of the molecular interactions between host and viral components and highlights DNAJC11 as a potential target for antiviral interventions. Full article

Investigations of endogenous plant circular RNAs (circRNAs) in several plant species have revealed changes in their circular RNA profiles in response to biotic and abiotic stresses. Recently, circRNAs have emerged as critical regulators of gene expression. The destructive impacts on agriculture due to plant viral infections necessitate better discernment of the involvement of plant circRNAs during viral infection. However, few such studies have been conducted hitherto. Sobemoviruses cause great economic impacts on important crops such as rice, turnip, alfalfa, and wheat. Our current study investigates the dynamics of plant circRNA profiles in the host Arabidopsis thaliana (A. thaliana) during infections with the sobemoviruses Turnip rosette virus (TRoV) and Rice yellow mottle virus (RYMV), as well as the small circular satellite RNA of the Lucerne transient streak virus (scLTSV), focusing on circRNA dysregulation in the host plants and its potential implications in triggering plant cellular defense responses. Towards this, two rounds of deep sequencing were conducted on the RNA samples obtained from infected and uninfected plants followed by the analysis of circular RNA profiles using RNA-seq and extensive bioinformatic analyses. We identified 760 circRNAs, predominantly encoded in exonic regions and enriched in the chloroplast chromosome, suggesting them as key sites for circRNA generation during viral stress. Gene ontology (GO) analysis indicated that these circRNAs are mostly associated with plant development and protein binding, potentially influencing the expression of their host genes. Furthermore, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed photosynthesis as the most affected pathway. Interestingly, the non-coding exogenous scLTSV specifically induced several circRNAs, some of which contain open reading frames (ORFs) capable of encoding proteins. Our biochemical assays demonstrated that transgenic expression of scLTSV in A. thaliana enhanced resistance to TRoV, suggesting a novel strategy for improving plant viral resistance. Our results highlight the complexity of circRNA dynamics in plant–virus interactions and offer novel insights into potential circRNA-based strategies for enhancing plant disease resistance by modulating the differential expression of circRNAs. Full article

Porcine rotavirus (PoRV), a primary etiological agent of viral diarrhea in piglets, frequently co-infects with other enteric pathogens, exacerbating disease severity and causing substantial economic losses. Its genetic recombination capability enables cross-species transmission potential, posing public health risks. Globally, twelve G genotypes and thirteen P genotypes have been identified, with G9, G5, G3, and G4 emerging as predominant circulating strains. The limited cross-protective immunity between genotypes compromises vaccine efficacy, necessitating genotype surveillance to guide vaccine development. While conventional molecular assays demonstrate sensitivity, they lack rapid genotyping capacity and face technical limitations. To address this, we developed a novel diagnostic platform integrating reverse transcription recombinase-aided amplification (RT-RAA) with CRISPR–Cas12a. This system employs universal primers for the simultaneous amplification of G4/G5/G9 genotypes in a single reaction, coupled with sequence-specific CRISPR recognition, achieving genotyping within 50 min at 37 °C with 10⁰ copies/μL sensitivity. Clinical validation showed a high concordance with reverse transcription quantitative polymerase chain reaction (RT-qPCR). This advancement provides an efficient tool for rapid viral genotyping, vaccine compatibility evaluation, and optimized epidemic control strategies. Full article

Highly pathogenic avian influenza (HPAI) H5N1, particularly clade 2.3.4.4b, has demonstrated an unprecedented capacity for cross-species transmission, with recent reports confirming its presence in dairy cattle in the United States of America (USA) in 2024. This unexpected spillover challenges traditional understanding of the virus’s host range and raises serious public health and veterinary concerns. Infected cattle presented with clinical signs such as decreased milk production, thickened or discolored milk, respiratory issues, and lethargy. Pathological findings revealed inflammation of the mammary glands and the detection of a virus in nasal secretions and raw milk, suggesting a potential for both intra- and interspecies transmission. While the current risk of human-to-human transmission remains low, the detection of H5N1 in a human exposed to infected cattle highlights the need for heightened surveillance and protective measures. Moreover, the presence of infectious viruses in the food chain, particularly in unpasteurized milk, introduces a new dimension of zoonotic risk. This review synthesizes emerging evidence on the epidemiology, pathology, diagnostic findings, and zoonotic implications of HPAI H5N1 infection in cattle. It also highlights the importance of genomic surveillance, intersectoral collaboration, and One Health approaches in managing this evolving threat. As the virus continues to circulate and adapt across diverse hosts, including wild birds, domestic poultry, and now mammals, the potential for reassortment and emergence of novel strains remains a significant concern. Immediate actions to strengthen biosecurity, monitor viral evolution, and protect both animal and human populations are critical to mitigate the global risk posed by this expanding panzootic. Full article

Pseudorabies virus (PRV) can infect a wide range of animal species, including swine and rodents. Infection in pigs is associated with significant economic losses in the global pork industry and is characterized by acute, often fatal disease, as well as central nervous system (CNS) invasion, which leads to neurological manifestations. Although PRV replication has been extensively characterized in certain murine neuronal cell lines such as Neuro-2a, the mechanisms underlying PRV-induced neuroinflammatory injury and necroptosis remain largely unclear. In this study, Kunming mice and mouse astrocytes (C8-D1A) were infected with PRV-GXLB-2013 at different doses to evaluate neurological injury and inflammatory responses. Given that the NF-κB/MLKL signaling pathway was found to be activated during PRV infection, a selective MLKL inhibitor, necrosulfonamide (NSA), was applied to investigate the role of necroptosis in PRV-induced neuroinflammatory damage. Mice infected with higher viral doses showed increased mortality, severe neurological symptoms, elevated brain inflammation, and pathological changes. In C8-D1A cells, PRV infection significantly upregulated inflammatory cytokines and key components of the NF-κB/MLKL pathway. Importantly, NSA treatment markedly reduced these inflammatory responses, mitochondrial damage, and cellular necrosis. Collectively, these findings suggest that PRV infection triggers neuroinflammatory injury through the activation of necroptosis and the NF-κB/MLKL signaling pathway. This study provides novel mechanistic insights into PRV-induced neurological damage and highlights potential therapeutic targets for intervention. Full article

Highly pathogenic henipaviruses (Nipah and Hendra viruses) and parahenipaviruses (Langya virus) have demonstrated significant zoonotic potential. We aimed to identify Henipavirus or Parahenipavirus species in rodents and shrews in South Korea to underline the potential zoonotic transmission risk. Kidney and lung tissues from 285 rodents and shrews were screened for Henipavirus and Parahenipavirus using quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) targeting the Gamak virus and Daeryong virus (DARV) sequences. Based on the qRT-PCR results, 75 out of the 285 individuals tested positive, with the highest viral loads in the kidneys of Apodemus agrarius, Crocidura lasiura, and Crocidura shantungensis. A kidney sample from C. shantungensis that exhibited the lowest Ct value was further analyzed using PCR, Sanger sequencing, and metagenomic analysis, yielding a near-complete genome of a novel Parahenipavirus, designated Parahenipavirus_GH (PHNV-GH), which is phylogenetically related to DARV and Jingmen virus but exhibits distinct genomic features. Ixodes granulatus ticks were also identified on the host shrew. The identification of PHNV-GH in southern South Korea expands the known geographical distribution range of parahenipaviruses and highlights the ongoing risk of zoonotic transmission. Given the uncertain transmission dynamics and pathogenic potential of parahenipaviruses, comprehensive environmental surveillance and characterization of emerging parahenipaviruses are essential for preventing future outbreaks. Full article

Apple mosaic disease (AMD) is a widespread viral disease affecting apple-growing regions around the world. Recent studies have identified a novel ilarvirus, apple necrotic mosaic virus (ApNMV), as the major causal agent of AMD in China. However, the molecular mechanisms underlying AMD pathogenesis and the global gene expression changes during mosaic symptom development remain largely unknown. In this study, we performed transcriptome analysis to investigate apple gene responses to AMD. A total of 815 differentially expressed genes (DEGs) were identified in mosaic leaves compared to healthy controls, while 1050 DEGs were found between symptomless leaves (infected with ApNMV) and mosaic leaves. Functional enrichment analysis revealed that these DEGs were predominantly involved in carbohydrate metabolism, oxidation-reduction processes, secondary metabolite biosynthesis, and plant hormone signal transduction. Further biological assays demonstrated that the manifestation of mosaic symptoms in apple leaves was associated with reactive oxygen species (ROS) accumulation and downregulation of ROS-scavenging genes. Collectively, our findings provide new insights into the molecular basis of ApNMV-induced mosaic symptom development in apple and offer potential targets for the management of AMD. Full article

Pseudorabies virus (PRV) is a highly contagious pathogen in swine that can cross species barriers and infect other mammals, including humans. Given the potential for interspecies transmission and its threat to public health, understanding the molecular biology of PRV strains is essential for developing effective control measures and preparing for future pandemics. In this study, a novel PRV strain, PRV-HL-2021, was isolated from an outbreak in Heilongjiang Province, China. The viral genome was used to establish a reverse genetics system based on a fosmid library of the PRV-HL-2021 genome. This system facilitated the creation of recombinant PRV, including one expressing EGFP and another with deletions in the US9, gI, and gE genes. PRV-HL-2021 was found to be highly lethal to mice in vivo. The recombinant PRV strains, such as rPRV-US9-EGFP and rPRV-delgI/gE/US9, exhibited growth characteristics similar to the parental PRV-HL-2021 strain. The isolation and characterization of PRV-HL-2021 contribute to a better understanding of the genetic diversity of PRV strains. The developed reverse genetics system provides valuable tools for investigating viral functions, creating genetically modified PRV strains, and advancing the development of safer vaccines. These findings will enhance strategies for controlling PRV outbreaks and mitigating its impact on both animal and public health. Full article

The establishment and partial characterization of three continuous cell lines from European freshwater fish species are provided. The three new cell lines, designated NPL-3, AF-1, and PF-1, were created from larvae of northern pike (Esox lucius) and fin tissues of asp (Leuciscus aspius) and European perch (Perca fluviatilis) fin tissues, respectively. All three cell lines have been subcultured more than 90 times since their establishment. Cells were optimally maintained at 25 °C in M199 medium supplemented with 10% fetal bovine serum. The NPL-3 and AF-1 cells are susceptible to spring viraemia of carp virus, pike fry rhabdovirus, ictalurid herpesvirus 2, and European catfish virus, while in the PF-1 cells, only the latter two viruses were successfully propagated. These newly established cell lines could serve as diagnostic tools for the aforementioned economically important viral diseases. They might be effective appliances for isolating novel viruses from northern pike, asp, European perch, and other closely related fish species. Full article

Background: Birnaviruses infect a wide range of aquatic and terrestrial hosts, including several economically important fish species. This study aimed to isolate and characterize a novel birnavirus strain from mandarin fish (Siniperca chuatsi), a high-value freshwater species in Chinese aquaculture. Methods: A novel strain, designated mandarin fish birnavirus (MFBV), was isolated from diseased fish and propagated in SCK cells. The complete genome was determined using high-throughput sequencing and RACE. Viral replication kinetics, tissue distribution, and pathogenicity were assessed through in vitro infection, RT-qPCR, histopathology, and experimental challenges. In addition, disinfectant sensitivity and environmental stability were evaluated. Results: The MFBV genome comprises two segments (A: 3539 bp; B: 2719 bp), and phylogenetic analysis revealed close relatedness to largemouth bass birnavirus (LBBV) and Lates calcarifer birnavirus (LCBV). MFBV displayed rapid replication in SCK cells, completing a replication cycle in 8–10 h. In juvenile and fry fish, an experimental infection caused acute disease with cumulative mortality ranging from 41.8% to 83.6%, with fry showing higher susceptibility. Viral RNA was detected in multiple tissues (7.9 × 10⁶–7.9 × 10⁷ copies/μg RNA), and histopathological lesions were observed in the intestine, spleen, and kidney. MFBV was highly sensitive to glutaraldehyde (20 ppm), while other disinfectants showed reduced efficacy. Viral half-life ranged from 36.5 to 144.5 h at room temperature. Conclusions: These findings demonstrate that MFBV can induce acute systemic infection in mandarin fish. The results offer new insights into the genomic and biological features of birnaviruses, contributing to improved disease management and viral taxonomy. Full article

Bovine enteroviruses (BEVs) are emerging pathogens with poorly understood evolutionary dynamics and zoonotic potential. Here, we report the discovery of a novel recombinant BEV strain, HeN-2022, isolated from cattle in China. Genomic analysis revealed that HeN-2022 is a primary hybrid of BEV-E1 (VG527, Ireland) and BEV-E4 (GX1901, China), with recombination breakpoints in the VP1 gene and 5′ UTR. Divergence dating traced its origin to 1991, predating closely related strains. Experimental infection in sheep demonstrated asymptomatic viral shedding (peak at 5 dpi) and robust neutralizing antibody responses, highlighting the potential cross-species adaptability. These findings underscore recombination as a potential key driver of BEV evolution and emphasize the need for global surveillance to address emerging livestock pathogens. Full article

The role of ferroptosis—a novel iron-dependent programmed cell death pathway—in infectious spleen and kidney necrosis virus (ISKNV) infection remains poorly understood. Here, we demonstrate that ISKNV infection induces ferroptosis in CPB cells. Following ISKNV challenge, CPB cells exhibited hallmark morphological alterations including mitochondrial shrinkage, increased membrane density, and cristae reduction. Biochemical assays confirmed significant time-dependent elevations in ferroptosis markers: malondialdehyde (MDA, 1.7-fold), reactive oxygen species (ROS, 3.14-fold), and ferrous iron (Fe²⁺, 1.42-fold) compared to controls (p < 0.05). Mechanistic studies revealed that ISKNV downregulated glutathione peroxidase 4 (GPx4) while upregulating acyl-CoA synthetase long-chain family member 4 (ACSL4), as validated by quantitative real-time PCR (qRT-PCR) and immunoblotting. Ferroptosis induction with erastin enhanced ISKNV replication, whereas inhibition with liproxstatin-1 suppressed viral yield. These findings establish that ISKNV exploits ferroptosis to facilitate its replication, and pharmacological blockade of this pathway significantly suppresses viral propagation, providing a new strategy and intervention approach for controlling ISKNV infection. Full article