Search Results (2,192)

It is estimated that nearly all individuals have been infected with herpesviruses, with herpes simplex virus type 1 (HSV-1) representing the most prevalent virus. In most cases, HSV-1 causes non-life-threatening skin damage in adults. However, in patients with compromised immune systems, it can cause serious diseases, including death. The situation is further complicated by the emergence of strains that are resistant to both traditional and novel antiviral drugs. It is, therefore, imperative that new methods of combating HSV-1 and other herpesviruses be developed without delay. CRISPR/Cas systems may prove an effective means of controlling herpesvirus infections. This review presents the current understanding of the underlying molecular mechanisms of HSV-1 infection and discusses four potential applications of CRISPR/Cas systems in the fight against HSV-1 infections. These include the search for viral and cellular genes that may serve as effective targets, the optimization of anti-HSV-1 activity of CRISPR/Cas systems in vivo, the development of CRISPR/Cas-based HSV-1 diagnostics, and the validation of HSV-1 drug resistance mutations. Full article

The beneficial effect of milk kefir on respiratory heath has been previously demonstrated; however, water kefir and kefiran in the context of respiratory viral infections have not been investigated. Water kefir and kefiran could be alternatives to milk kefir for their application in persons with lactose intolerance or milk allergy and could be incorporated into vegan diets. Using mice models, this work demonstrated that the oral administration of water kefir or kefiran can modulate the respiratory Toll-like receptor (TLR3)-mediated innate antiviral immunity and improve the resistance to respiratory syncytial virus (RSV) infection. The treatment of mice with water kefir or kefiran for 6 days improved the production of interferons (IFN-β and IFN-γ) and antiviral factors (Mx2, OAS1, RNAseL, and IFITM3) in the respiratory tract after the activation of the TLR3 signaling pathway, differentially modulated the balance of pro- and anti-inflammatory cytokines, reduced RSV replication, and diminished lung tissue damage. Maintaining a proper balance between anti-inflammatory and pro-inflammatory mediators is vital for ensuring an effective and safe antiviral immune response, and the results of this work show that water kefir and kefiran would help to maintain that balance promoting a controlled inflammatory response that defends against infection while minimizing tissue damage. Full article

Coinfections by multiple pathogens, including viruses and bacteria, have severely impacted tilapia aquaculture globally. This study evaluated the impacts of dietary supplementation on red hybrid tilapia (Oreochromis spp.) coinfected with Tilapia lake virus (TiLV) and Aeromonas hydrophila. Fish were divided into three groups: a control group on a normal diet, and two experimental groups received diets supplemented with strategy A, an organic acid blend combined with a lyso-phospholipid-based digestive enhancer, and strategy B, an organic acid blend combined with natural immunostimulants and nutrients. Following exposure to both pathogens, the fish supplemented with strategies A and B showed lower cumulative mortality rates of 50.0% and 41.7%, respectively, compared to 76.3% in the control group. Notably, fish fed with strategy B-supplemented diet displayed a stronger immune response, with a lower expression of il-8, mx, and rsad2, and showed less pathological changes in the liver, spleen, and intestines, suggesting enhanced resistance to coinfection. In contrast, fish receiving strategy A did not exhibit significant changes in the immune-related gene expression or pathogen load, but demonstrate less pathological alterations, indicating intestinal protection. These findings highlight the potential of feed additives, particularly strategy B, to reduce the impact of virus-bacterial coinfections and improve outcomes in tilapia farming. Full article

This study investigates the settling preferences and feeding behavior of the Bemisia tabaci whitefly on six cassava cultivars using electrical penetration graph techniques. Six distinct electrical penetration graph waveforms—non-probing, stylet pathway, phloem salivation, phloem ingestion, intracellular puncture, and xylem feeding—were identified and analyzed. Significant differences in the frequency and duration of these waveforms were observed among the cassava cultivars. The whiteflies spent the majority of their time in the non-probing phase, particularly on the Huaybong 80, Kasetsart 50, Rayong 9, and Rayong 72 cultivars. CMR-89 cultivar exhibited higher total probe durations in the phloem salivation and ingestion waveforms, suggesting a greater potential for transmission of the Sri Lankan cassava mosaic virus. The study also examined trichome density and size across the cassava cultivars, revealing that CMR-89 had the highest density and small trichomes, while Huaybong 80 had the lowest density. Trichome characteristics significantly impacted whitefly behavior: larger trichomes were negatively correlated with whitefly settling, whereas higher trichome density was positively correlated with longer settling durations. These findings indicate that trichome-based resistance mechanisms are crucial in whitefly deterrence. Overall, the results suggest that cultivars with lower trichome density and larger trichomes are more resistant to whitefly infestation and subsequent Sri Lankan cassava mosaic virus transmission. These insights are valuable for cassava breeding programs focused on enhancing pest resistance, highlighting the importance of trichome characteristics in developing more resilient cassava varieties. Full article

Swine influenza A viruses (IAVsw) are important causes of disease in pigs but also constitute a public health risk. IAVsw strains show remarkable differences in pathogenicity. We aimed to generate airway organoids from the porcine lower respiratory tract and use these to establish well-differentiated airway epithelial cell (WD-AEC) cultures grown at an air–liquid interface (ALI) for in vitro screening of IAVsw strain virulence. Epithelial cells were isolated from bronchus tissue of juvenile pigs, and airway organoids were cultured in an extracellular matrix in a culture medium containing human growth factors. Single-cell suspensions of these 3D organoids were seeded on Transwell filters and differentiated at ALI to form a pseudostratified epithelium containing ciliated cells, mucus-producing cells and tight junctions. Inoculation with a low dose of IAVsw in a low volume inoculum resulted in virus replication without requiring the addition of trypsin, and was quantified by the detection of viral genome loads in apical washes. Interestingly, inoculation of an H3N2 strain known to cause severe disease in pigs induced a greater reduction in trans-epithelial resistance and more damage to tight junctions than H1N2 or H1N1 strains associated with mild disease in pigs. We conclude that the porcine WD-AEC model is useful in assessing the virulence of IAVsw strains. Full article

Which patients should be monitored for coinfections or should receive empirical antibiotic treatment, in patients with an acute viral respiratory infection, is largely unknown. We evaluated the prevalence, characteristics, outcomes of coinfected patients, and risk factors associated with a coinfection among patients with an acute viral infection. A retrospective, single-center study recruited consecutive patients from October 2022 to March 2023 presenting to the emergency department with signs of a respiratory tract infection. Patients were screened for respiratory viruses and bacterial/fungal secondary infections according to local standard procedures. Outcomes included severe disease, in-hospital complications, all-cause in-hospital and ICU-related mortality, time to death, time to discharge, and time to coinfection. The analysis included 652 patients. A viral infection and a secondary bacterial/fungal infection were detected in 39.1% and 40% of cases. Compared with the rest of the cohort, coinfected patients had more frequently severe disease (88.3%, p < 0.001; 51% in patients with SARS-CoV-2) and higher in-hospital mortality (16.5%, p = 0.010). Nephropathy (OR 3.649, p = 0.007), absence of COVID-19 vaccination (OR 0.160, p < 0.001), SARS-CoV-2 infection (OR 2.390, p = 0.017), and lower blood pressure at admission (OR 0.980, p = 0.007) were independent risk factors for coinfection. Multidrug-resistant pathogens were detected in 30.8% of all coinfections. Patients with a viral infection are at high risk of bacterial coinfections, which carry a significant morbidity and mortality burden. Full article

The growing risk of contracting viral infections due to high-density populations and ecological disruptions, such as climate change and increased population mobility, has highlighted the necessity for effective antiviral treatment and preventive measures against Dengue virus (DENV), Chikungunya virus (CHIKV), and Zika virus (ZIKV). Recently, there has been increasing attention on the use of probiotics as a potential antiviral option to reduce virus infections. The present study aimed to assess the immunomodulatory effects of heat-killed Lactococcus lactis strain plasma (LC-Plasma) on peripheral blood mononuclear cells (PBMCs) and its subsequent antiviral response against DENV, CHIKV, and ZIKV. To evaluate the immunomodulatory effects of LC-Plasma on PBMCs isolated from healthy individuals, PBMCs were cultured at a density of 2 × 10⁵ cells/well and stimulated with 10 µg/mL of LC-Plasma. LC-plasma-stimulated PBMCs demonstrated elevated interferon-alpha (IFN-α) production and cluster of differentiation 86 (CD86) and human leukocyte antigen-DR isotype (HLA-DR) upregulation, potentially linked to plasmacytoid dendritic cell (pDC) activation. The replication of DENV, CHIKV, and ZIKV was dose-dependently inhibited when Huh-7 cells were stimulated with LC-Plasma-stimulated PBMC supernatant (LCP Sup). IFN-stimulated gene (ISG) expression, including IFN-stimulated gene 15 (ISG15), IFN-stimulated exonuclease gene 20 (ISG20), IFN-induced transmembrane protein 1 (IFITM-1), myxovirus resistance protein A (MxA), and radical S-adenosyl methionine domain-containing protein 2 (RSAD2), was significantly upregulated in LCP Sup-stimulated Huh-7 cells. Findings from this study indicate that LC-Plasma has the potential to induce IFN-α production, leading to an enhancement in the expression of ISGs and contributing to a broad-spectrum antiviral response. Thus, LC-Plasma may serve as a rational adjunctive treatment to ameliorate viral diseases, warranting future clinical trials. Full article

The molecular mechanisms of plant responses to phytophagous insect eggs are poorly understood, despite their importance in insect–plant interactions. This study investigates the plant defense mechanisms triggered by the eggs of whitefly Bemisia tabaci, a globally significant agricultural pest. A transcriptome comparison of tobacco plants with and without eggs revealed that whitefly eggs may activate the response of defense-related genes, including those involved in the salicylic acid (SA) signaling pathway. SA levels are induced by eggs, resulting in a reduction in egg hatching, which suggests that SA plays a key role in plant resistance to whitefly eggs. Employing Agrobacterium-mediated transient expression, virus-induced gene silencing assays, DNA–protein interaction studies, and bioassays, we elucidate the regulatory mechanisms involved. Pathogenesis-related proteins NtPR1-L1 and NtPR5-L2, downstream of the SA pathway, also affect whitefly egg hatching. The SA-regulated transcription factor NtWRKY70a directly binds to the NtPR1-L1 promoter, enhancing its expression. Moreover, NtPR1-L1 promotes callose deposition, which may impede the eggs’ access to water and nutrients. This study establishes the SA-WRKY70-PR-callose axis as a key mechanism linking plant responses and defenses against whitefly eggs, providing new insights into the molecular interactions between plants and insect eggs. Full article

Background/Objectives: Sorafenib and lenvatinib are tyrosine kinase inhibitors used in hepatocellular carcinoma (HCC) treatment. This study investigates how hepatitis B virus (HBV) infection affects their efficacy in HepG2 hepatoma cells. Methods: HepG2 and HBV-infected HepG2/2215 cells were treated with varying concentrations of both drugs. The cell viability, cell cycle gene expression, cycle progression, and phosphorylation levels of ERK and AKT were analyzed. Results: The HBV-infected cells showed significant alterations in their cell cycle gene expressions, with an 80-fold increase in CCND2 expression and a higher proportion of cells in the G2/M phase, indicating enhanced proliferation. While both drugs decreased HepG2 cell viability in a concentration-dependent manner, HBV infection conferred resistance, as evidenced by the increased viable cells in the HepG2/2215 cultures. Sorafenib and lenvatinib decreased key cyclin and cyclin-dependent kinase expressions in uninfected cells, with less effect on the HBV-infected cells. Both drugs lowered the pERK and pAKT levels in the HepG2 cells. In the HBV-infected cells, sorafenib reduced the pERK and pAKT levels to a lesser extent. However, treatment with lenvatinib elevated the levels of pERK and pAKT. Conclusions: In conclusion, HBV infection increases resistance to both sorafenib and lenvatinib in hepatoma cells by influencing the cell cycle regulatory genes and critical signaling pathways. However, the resistance mechanisms likely differ between the two medications. Full article

Chitosan is a natural biopolymer that is industrially produced from chitin via deacetylation. Due to its unique properties and a plethora of biological activities, chitosan has found application in diverse areas from biomedicine to agriculture and the food sector. Chitosan is regarded as a biosafe, biodegradable, and biocompatible compound that was demonstrated to stimulate plant growth and to induce a general plant defense response, enhancing plant resistance to various pathogens, including bacteria, fungi, nematodes, and viruses. Here, we focus on chitosan application as an antiviral agent for plant protection. We review both the pioneer studies and recent research that report the effect of plant treatment with chitosan and its derivatives on viral infection. Special attention is paid to aspects that affect the biological activity of chitosan: polymer length and, correspondingly, its molecular weight; concentration; deacetylation degree and charge; application protocol; and experimental set-up. Thus, we compare the reported effects of various forms and derivatives of chitosan as well as chitosan-based nanomaterials, focusing on the putative mechanisms underlying chitosan-induced plant resistance to plant viruses. Full article

In agriculture, new and sustainable strategies are increasingly demanded to integrate the traditional management of viral diseases based on the use of virus-free propagation materials and resistant or tolerant cultivars and on the control of insect vectors. Among the possible Integrated Pest Management (IPM) approaches, organic biostimulants have shown promising results in enhancing plant tolerance to virus infections by improving plant fitness and productivity and modulating metabolic functions. In this study, the combination of two organic biostimulants, Alert D-Max and Resil EVO Q, composed of seaweed and alfalfa extracts, enzymatic hydrolysates, and micronized zeolite, was applied on the leaves and roots of zucchini squashes, both healthy and infected by zucchini yellow mosaic virus (ZYMV). Four applications were scheduled based on ZYMV inoculation timing, and plant vegetative and reproductive parameters were recorded along with the virus titre and symptom severity. The modulation of the expression of specific genes potentially involved in pattern-triggered immunity (PTI), systemic acquired resistance (SAR), and oxidative stress defence pathways was also investigated. Besides increasing the general fitness of the healthy plants, the biostimulants significantly improved the production of flowers and fruits of the infected plants, with a potential positive impact on their productivity. The repeated biostimulant applications also led to a one-tenth reduction in ZYMV titre over time and induced a progressive slowdown of symptom severity. Genes associated with SAR and PTI were up-regulated after biostimulant applications, suggesting the biostimulant-based priming of plant defence mechanisms. Due to the observed beneficial effects, the tested biostimulant mix can be an effective component of the IPM of cucurbit crops, acting as a sustainable practice for enhancing plant fitness and tolerance to potyviruses. Full article

The agricultural sector is facing unprecedented challenges as a result of climate change. As temperatures continue to rise and weather patterns shift, the dynamics of plant–virus interactions are significantly altered, requiring innovative solutions to ensure global food security. This review article examines the relationship between climate change and the prevalence and severity of cucumber viral diseases, their impact on cucumber yield and quality, and the subsequent economic implications, focusing on critical pathogens such as cucumber mosaic virus (CMV), cucumber leaf spot virus (CLSV), or cucumber vein yellowing virus (CVYV). It also aims to provide a comprehensive overview of the current state of knowledge and identify critical areas for future research and development in response to climate change. The review examines potential solutions to address these challenges. These include exploring the development of virus-resistant cucumber varieties and the use of RNA-based technologies for virus control. Full article

The electrical penetration graph (EPG) technique is of great significance in elucidating the mechanisms of virus transmission by piercing-sucking insects and crop resistance to these insects. The traditional method of manually processing EPG signals encounters the drawbacks of inefficiency and subjectivity. This study investigated the data augmentation and automatic identification of various EPG signals, including A, B, C, PD, E1, E2, and G, which correspond to distinct behaviors exhibited by the Asian citrus psyllid. Specifically, a data augmentation method based on an improved deep convolutional generative adversarial network (DCGAN) was proposed to address the challenge of insufficient E1 waveforms. A multi-criteria evaluation framework was constructed, leveraging maximum mean discrepancy (MMD) to evaluate the similarity between the generated and real data, and singular value decomposition (SVD) was incorporated to optimize the training iterations of DCGAN and ensure data diversity. Four models, convolutional neural network (CNN), K-nearest neighbors (KNN), decision tree (DT), and support vector machine (SVM), were established based on DCGAN to classify the EPG waveforms. The results showed that the parameter-optimized DCGAN strategy significantly improved the model accuracies by 5.8%, 6.9%, 7.1%, and 7.9% for DT, SVM, KNN, and CNN, respectively. Notably, DCGAN-CNN effectively addressed the skewed distribution of EPG waveforms, achieving an optimal classification accuracy of 94.13%. The multi-criteria optimized DCGAN-CNN model proposed in this study enables reliable augmentation and precise automatic identification of EPG waveforms, holding significant practical implications for understanding psyllid behavior and controlling citrus huanglongbing. Full article

Parasitic plants represent a significant challenge in global agriculture, with Broomrape (Orobanche/Phelipanche spp.) being a notable example of a holoparasitic species that targets the roots of host plants. This study employed comparative transcriptomics to investigate the mechanisms underlying the parasitism of P. aegyptiaca on melon, focusing on both resistant and susceptible interactions. The findings indicate that the critical phase of P. aegyptiaca parasitism occurs during the post-attachment stage. It is suggested that peptidases may play a role in the development of invasive cells, while cell wall-degrading enzymes (CWDEs) are likely involved in cell wall modification and degradation, and transferases, elicitors, and effectors may play a role in immune regulation. In this study, 25 tobacco rattle virus (TRV) recombinant vectors were successfully constructed and functionally validated using a host-induced gene silencing assay to explore the functions of candidate-secreted effector proteins. The results revealed that silencing Cluster-107894.0, Cluster-11592.0, and Cluster-12482.0 significantly decreased the parasitism rate of P. aegyptiaca on Nicotiana benthamiana. Notably, Cluster-107849.0 encodes a cellulase with hydrolase activity, Cluster-11592.0 encodes a periodic-dependent kinase inhibitor with phosphoprotein activity, and Cluster-12482.0 encodes a glucan 1,3-β-glucosidase with hydrolase activity. These findings potentially offer a novel theoretical framework and justification for understanding host–parasite plant interactions, and suggest new avenues for developing crop varieties resistant to parasitic infestation. Full article

Viral diversity and disease progression in chronic infections, and particularly how quasispecies structure affects antiviral treatment, remain key unresolved issues. Previous studies show that advanced liver fibrosis in long-term viral infections is linked to higher rates of antiviral treatment failures. Additionally, treatment failure is associated with high quasispecies fitness, which indicates greater viral diversity and adaptability. As a result, resistant variants may emerge, reducing retreatment effectiveness and increasing the chances of viral relapse. Additionally, using a mutagenic agent in monotherapy can accelerate virus evolution towards a flat-like quasispecies structure. This study examines 19 chronic HCV patients who failed direct-acting antiviral (DAA) treatments, using NGS to analyze quasispecies structure in relation to fibrosis as a marker of infection duration. Results show that HCV evolves towards a flat-like quasispecies structure over time, leading also to advanced liver damage (fibrosis F3 and F4/cirrhosis). Based on our findings and previous research, we propose that the flat-like fitness quasispecies structure is the final stage of any quasispecies in chronic infections unless eradicated. The longer the infection persists, the lower the chances of achieving a cure. Interestingly, this finding may also be applicable to other chronic infection and drug resistance in cancer. Full article