Search Results (20,254)

Background/Objectives: Hepatocellular carcinoma (HCC) remains a leading cause of global cancer mortality, with increasing incidence and persistently poor survival. Hepatitis C virus (HCV) is a major risk factor for HCC, and while the advent of direct-acting antivirals (DAAs) has significantly altered HCV-related hepatocellular cancer (HCC-HCV) risk, the global burden remains substantial. With the World Health Organization (WHO) aiming to reduce hepatitis-related deaths by 2030, we set out to evaluate global HCC-HCV trends from 1990 to 2021, stratified by sex, WHO region, and sociodemographic index (SDI), using data from the Global Burden of Disease (GBD) 2021 study. Methods: We analyzed age-standardized incidence (ASI), deaths, and disability-adjusted life years (DALYs) due to HCV-HCC from 1990 to 2021 using GBD 2021 data. Trends were stratified by WHO region, sociodemographic index (SDI), and sex. Joinpoint regression modeling was used to identify statistically significant temporal inflection points and calculate the annual percent change (APC) in unique time segments and average annual percent change (AAPC) over the entire study period (1990 to 2021). Results: Globally, deaths and DALYs attributable to HCV-HCC increased over the study period while ASI declined modestly. The region of the Americas exhibited the highest AAPC in all three metrics, potentially driven by an aging HCV-infected population, rising comorbidities (e.g., obesity, diabetes), and improved case detection. Nevertheless, on a global level, high-SDI regions showed the most favorable trends, particularly after 2016, likely reflecting the earlier adoption of DAAs and a differential success of WHO goals. Lower-SDI regions continued to exhibit increasing burden. Notably, ASI began to rise again between 2019 and 2021, suggesting an ongoing need to critically evaluate and restructure our approach to reducing HCV and HCV-HCC. Conclusions: Our findings underscore the urgent need for equity-driven, region-specific strategies to achieve better control of this highly morbid disease. Full article

Plant viruses have been traditionally considered pathogens restricted to plant hosts. However, recent studies have shown that some plant viruses can infect and replicate in filamentous fungi and oomycetes, suggesting that their host range is broader than previously thought, and that their ecological interactions are more complex. In this study, we investigated the ability of the well-characterized positive-sense RNA plant virus Tobacco mosaic virus (TMV) to replicate in four major phytopathogenic fungi from different taxonomic groups: Botrytis cinerea, Fusarium oxysporum f. sp. lycopersici, Verticillium dahliae, and Monilinia fructicola. Using a recombinant TMV-based vector expressing a green fluorescent protein (TMV-GFP-1056) as reporter, we demonstrated that TMV can enter, replicate, and persist within the mycelia of B. cinerea and V. dahliae—at least through the first subculture. However, it cannot replicate in F. oxysporum f. sp. lycopersici and M. fructicola. RNA interference (RNAi) is a conserved eukaryotic epigenetic mechanism that provides an efficient defence against viruses. We explored the role of RNAi in the interaction between TMV and the mycelia of V. dahliae and B. cinerea. Our results revealed a strong induction of the Dicer-like 1 and Argonaute 1 genes, which are key compounds of the RNA silencing pathway. This RNAi-based response impaired TMV-GFP replication in both fungi. Notably, despite viral replication and RNAi activation, the virulence of V. dahliae and B. cinerea on their respective host plants remained unaffected. These findings reinforce the emerging recognition of cross-kingdom virus transmission and interactions, which likely play a crucial role in pathogen ecology and viral evolution. Understanding these virus–fungus interactions not only sheds light on RNAi interference silencing mechanisms but also suggests that plant viruses like TMV could serve as simple and effective tools for functional genomic studies in fungi, such as in V. dahliae and B. cinerea. Full article

We aimed to explore SARS-CoV-2 evolution during in vitro neutralisation using next generation sequencing, and to determine whether sera from individuals immunised with two doses of the Pfizer-BioNTech vaccine (BNT162b2) were as effective at neutralising the variant of concern (VOC) Delta (B.1.617.2) compared to the earlier lineages Beta (B.1.351) and wild-type (A.2.2) virus. Using a live-virus SARS-CoV-2 neutralisation assay in Vero E6 cells, we determined neutralising antibody titres (nAbT) against three SARS-CoV-2 strains (wild type, Beta, and Delta) in 14 participants (vaccine-naïve (n = 2) and post-second dose of BNT162b2 vaccination (n = 12)), median age 45 years [IQR 29–65]; the median time after the second dose was 21 days [IQR 19–28]. The determination of nAbT was based on cytopathic effect (CPE) and in-house quantitative reverse transcriptase real-time quantitative polymerase chain reaction (RT-qPCR) to confirm SARS-CoV-2 replication. A total of 110 representative samples including inoculum, neutralisation breakpoints at 72 h, and negative and positive controls underwent genome sequencing. By integrating live-virus neutralisation assays with deep sequencing, we characterised both functional antibody responses and accompanying viral genetic changes. There was a reduction in nAbT observed against the Delta and Beta VOC compared with wild type, 4.4-fold (p ≤ 0.0006) and 2.3-fold (p = 0.0140), respectively. Neutralising antibodies were not detected in one vaccinated immunosuppressed participant and the vaccine-naïve participants (n = 2). The highest nAbT against the SARS-CoV-2 variants investigated was obtained from a participant who was vaccinated following SARS-CoV-2 infection 12 months prior. Limited consensus level mutations occurred in the various SARS-CoV-2 lineage genomes during in vitro neutralisation; however, consistent minority allele frequency variants (MFV) were detected in the SARS-CoV-2 polypeptide, spike (S), and membrane protein. Findings from countries with high COVID-19 incidence may not be applicable to low-incidence settings such as Australia; as seen in our cohort, nAbT may be significantly higher in vaccine recipients previously infected with SARS-CoV-2. Monitoring viral evolution is critical to evaluate the impact of novel SARS-CoV-2 variants on vaccine effectiveness, as mutational profiles in the sub-consensus genome could indicate increases in transmissibility and virulence or suggest the development of antiviral resistance. Full article

Tomato brown rugose fruit virus (ToBRFV) has been causing severe agricultural damage worldwide since its recent discovery. While related to tobacco mosaic virus, its properties and infection mechanisms are poorly understood. To uncover their structure and nanomechanics, we carried out atomic force microscopy (AFM) measurements on individual ToBRFV particles. The virions are rod-shaped with a height and width of 9 and 30 nm, respectively. Length is widely distributed (5–1000 nm), with a mode at 30 nm. ToBRFV rods displayed a 22.4 nm axial periodicity related to structural units. Force spectroscopy revealed a Young’s modulus of 8.7 MPa, a spring constant of 0.25 N/m, and a rupture force of 1.7 nN. In the force curves a step was seen at a height of 3.3 nm, which is related to virion wall thickness. Wall thickness was also estimated by predicting coat protein structure with AlphaFold, yielding a protein with a length of 7.3 nm. Accordingly, the structural element of ToBRFv is a right circular cylinder with an equal height and diameter of ~22 nm and a wall thickness between 3.3 and 7.3 nm. Thus, at least four to nine serially linked units are required to encapsidate a single, helically organized RNA genome. Fragmentation of ToBRFV into these cylindrical structural units may result in a facilitated release of the genome and thus efficient infection. Full article

This narrative review explains the history of anaphylactic or hypersensitivity reactions, their connection to the cardiovascular system, and Kounis syndrome, which is linked to hypersensitivity. Additional subjects discussed include immunoglobulin E and serum tryptase, common pathways of allergic and nonallergic cardiovascular events, current perspectives on Kounis syndrome, allergic myocardial infarction, allergic angina, and the impact of COVID-19 and its vaccination on Kounis syndrome. Kounis syndrome is a distinct kind of acute vascular disease that affects the coronary, cerebral, mesenteric, peripheral, and venous systems. Kounis syndrome is currently used to describe coronary symptoms linked to disorders involving mast cell activation and inflammatory cell interactions, such as those involving T-lymphocytes and macrophages, which further induce allergic, hypersensitive, anaphylactic, or anaphylactic insults. Platelet activating factor, histamine, neutral proteases like tryptase and chymase, arachidonic acid products, and a range of cytokines and chemokines released during the activation process are among the inflammatory mediators that cause it. Proinflammatory cytokines are primarily produced by mast cells in COVID-19 infections. Mast cell-derived proteases and eosinophil-associated mediators are also more prevalent in the lung tissues and sera of COVID-19 patients. As a modern global threat to civilization, COVID-19 is linked to chemical patterns that can activate mast cells; therefore, allergic stimuli are usually the reason. Virus-associated molecular patterns can activate mast cells, but allergic triggers are typically the cause. By activating SARS-CoV-2 and other toll-like receptors, a variety of proinflammatory mediators, including IL-6 and IL-1β, are released, potentially contributing to the pathology of COVID-19. Full article

Hepatitis B virus (HBV) remains a major global health challenge, with over 296 million people chronically infected worldwide. Despite the availability of antiviral therapies, a functional cure is rarely achieved, highlighting the need for novel therapeutic strategies. RNA 5-methylcytosine (m⁵C) is a pivotal epitranscriptomic mark implicated in RNA stability, transport, and translation. Emerging evidence shows that m⁵C is conserved within HBV RNA and plays critical roles in the viral life cycle. This review provides a comprehensive overview of the molecular mechanisms governing m⁵C deposition and recognition, summarizes recent advances in m⁵C biology, and highlights the emerging role of epitranscriptomic m⁵C regulation in HBV infection. We discuss the identification of HBV-specific m⁵C sites, the functions of key regulatory enzymes, and their interplay in viral RNA stabilization and evasion of innate immune responses. Interplay between m⁵C and other RNA modifications—particularly N6-methyladenosine (m⁶A)—is examined alongside virus-specific m⁵C regulation in EV71, HIV, HCV, EBV, and SARS-CoV-2. Potential links between m⁵C dysregulation and HBV-induced hepatocarcinogenesis are outlined, and emerging therapeutic strategies targeting the m⁵C machinery are highlighted. Together, these insights position the epitranscriptomic landscape as a promising avenue for innovative antiviral strategies. Full article

Influenza A virus pandemics pose a persistent global health threat, and emerging antiviral resistance underscores the critical importance of developing novel broad-spectrum therapeutic agents. Building on licorice’s (Glycyrrhiza spp.) historical use in traditional Chinese medicine for respiratory infections—as documented in the Chinese Guidelines for Diagnosis and Treatment of Influenza—and its demonstrated anti-SARS-CoV-2 activity, we identified licoflavone B as a potent anti-influenza agent, bridging ethnopharmacological knowledge with mechanistic validation. In this study, we identified licoflavone B, a natural flavonoid derived from licorice (Glycyrrhiza spp.), as a potent inhibitor of diverse influenza viruses, including multiple influenza A subtypes and type B virus. Mechanistic studies revealed that licoflavone B selectively targets the viral RNA-dependent RNA polymerase (RdRp), effectively suppressing viral replication. The compound exhibits a favorable selectivity index (SI = 14.9–29.9), indicating a promising therapeutic window. Molecular docking simulations identified potential binding interactions between licoflavone B and regions of the RdRp complex, which were further validated by dose-dependent inhibition of viral nucleoprotein (NP) and polymerase subunit PB2 expression in Western blot and immunofluorescence assays. In addition, licoflavone B maintained broad-spectrum antiviral activity against multiple influenza strains, including H1N1 (A/Puerto Rico/8/34), H3N2 (A/Darwin/9/2021), and a clinical influenza B isolate (B/Beijing/ZYY-B18/2018). These findings position licoflavone B as a promising lead compound for developing next-generation, broad-spectrum antiviral therapies against influenza and potentially other viruses. Full article

Background: Respiratory syncytial virus (RSV) bronchiolitis remains a leading cause of hospitalization in infants, particularly those with risk factors such as prematurity or chronic diseases. Nirsevimab, a long-acting monoclonal antibody, has recently been approved for RSV prevention. However, parental acceptance of this novel immunoprophylaxis is crucial for effective implementation. The aim of this study was to investigate parental acceptance of nirsevimab prophylaxis for RSV among eligible neonates in Emilia-Romagna, Italy, and to identify factors influencing decision making. Methods: A prospective, multicenter observational study enrolled 1042 parents of neonates eligible for nirsevimab prophylaxis according to regional criteria. Parents completed a semi-structured questionnaire during pre-immunization counseling, exploring knowledge, attitudes, perceived risks, information sources, and willingness to accept prophylaxis. Statistical analysis assessed associations between parental characteristics and acceptance rates. Results: Among the 1042 respondents, 87.0% (n = 907) expressed willingness to administer nirsevimab to their child, while 2.2% (n = 23) refused and 8.8% (n = 92) were undecided. Higher acceptance was significantly associated with awareness of RSV risks (72.1% vs. 41.7%, p < 0.01), belief in nirsevimab’s high efficacy (46.2% vs. 18.3%, p < 0.01), and lower concern over side effects (10.6% vs. 27.8%, p < 0.01). Trust in primary care pediatricians and the healthcare system was also notably higher among accepting parents (p < 0.001). Willingness to pay declined with a hypothetical EUR 250 cost but remained higher among the acceptance group (71.0% vs. 50.4%, p < 0.001). Conclusions: Parental acceptance of nirsevimab in Emilia-Romagna was high, though significant gaps in knowledge and concerns about safety persist. Targeted educational strategies that clarify the nature, efficacy, and safety of nirsevimab—alongside maintaining cost-free access—are essential to support the successful implementation of RSV prophylaxis programs. Full article

Mayaro virus (MAYV) is an alphavirus transmitted by mosquito vectors. Among the three MAYV genotypes (D, L, and N), genotype D has the broadest geographical distribution in Latin America and the Caribbean. The virus can be transmitted by the Aedes, Anopheles, and Haemagogus mosquitoes. To explore the potential expansion of MAYV across the Atlantic Ocean, we compared MAYV (D) infection kinetics in Floridian Aedes aegypti with New World (Anopheles albimanus) and Old World (Anopheles gambiae) anophelines. The MAYV infection of both An. albimanus and An. gambiae was rapid, resulting in a higher dissemination rate than Ae. aegypti. We detected MAYV in saliva from An. albimanus (16.6% transmission rate) as early as 2 days post-infection (dpi), increasing to 60% after 7 dpi, a phenomenon that has not been described (2 dpi) to date for mosquitoes. We observed similar increases in the MAYV infection of the ovaries and noted marked differences in fecundity for each species tested. Although the MAYV infection in An. gambiae was rapid, mosquito lifespan was significantly reduced as compared with both Ae. aegypti and An. albimanus. We discuss the implications of our observations on the MAYV transmission risk in Africa by An. gambiae and in the Caribbean and Central America by An. albimanus. Full article

Rift Valley Fever Virus (RVFV) is an arbovirus that predominantly affects sheep, goats, and cattle, causing epizootics in livestock and epidemics in humans. Infection in pregnant livestock leads to high abortion rates and neonatal mortality. In humans, RVFV usually causes a self-limiting febrile illness, but severe forms can develop, such as hepatitis, hemorrhage, encephalitis, and death. In addition, the association between RVFV infection during pregnancy and miscarriages or stillbirths has been documented. RVFV is transmitted by a range of mosquito species, and, due to the diffusion of these insects, the virus has spread in several world regions, making possible the risk of a public health emergency. Nevertheless, research remains limited and cellular pathology is still poorly characterized. This work aimed to fill some knowledge gaps on the comprehension of RVFV pathogenesis. For this purpose, transmission electron microscopy (TEM) was used to analyze cellular modifications associated with RVFV morphogenesis in four human cell lines (HuH-7, LAN-5, A549, and HTR-8/SVneo) derived from liver, brain, lung, and placenta. Our results showed that all four cell lines are permissive to RVFV infection and highlighted differences in the cytopathogenesis associated with the cell type. These findings could have important implications in understanding disease mechanisms and developing antiviral strategies. Full article

Rice planthoppers are the most destructive pests of rice production and the vectors of rice viruses. Fenmezoditiaz as a novel mesoionic insecticide is used for rice planthopper management by targeting the insect’s neural nicotinic acetylcholine receptor. This study aimed to evaluate the effects of fenmezoditiaz on the acquisition, propagation, and transmission of southern rice black-streaked dwarf virus (SRBSDV) by the white-backed planthopper, Sogatella furcifera (Hemiptera: Delphacida). The results revealed that sublethal concentrations of fenmezoditiaz significantly impaired SRBSDV acquisition and viral replication in S. furcifera. Fenmezoditiaz-treated viruliferous S. furcifera exhibited a lower transmission efficiency of SRBSDV to un-infected rice seedlings. Electrical penetration graph (EPG) recordings revealed prolonged non-probing (NP), salivary secretion (N2/N3), and xylem feeding (N5) durations, alongside shortened phloem contact behavior (N4a/N4b), of fenmezoditiaz-treated individuals, indicating disrupted feeding behaviors, which are critical for reducing viral infection. By reducing viral titers and interfering with phloem ingestion, fenmezoditiaz significantly suppresses SRBSDV transmission. These findings revealed fenmezoditiaz’s dual role in pest control and viral transmission blockage, providing a foundation for incorporation into integrated management of vector-borne plant viruses. Full article

Children with COVID-19 typically experience milder symptoms and lower hospitalization rates, though severe cases do occur. Understanding age-related immune responses is crucial for future preparedness. We characterized immune response dynamics to SARS-CoV-2 in 145 samples from 119 pediatric patients (<18 years) with confirmed infection, assessed at four distinct time points: <14 days, 14 days–3 months, 3–6 months, and 6–12 months post-infection. At infection, patients presented increased activated T-cells, higher levels of exhaustion (i.e., PD-1⁺), lower numbers of unswitched memory B-cells, and increased antibody-secreting cells (ASCs). Both humoral and cellular anti-SARS-CoV-2 responses increased over time (all patients showed measurable responses in the last assessment). Asymptomatic/mildly symptomatic patients (58.6%) showed increased specific cellular responses from infection onwards, along with enriched memory B-cell subsets (but not ASCs), and distinct T-cell activation profiles. Children with severe disease were younger, predominantly boys, displayed altered T/B-cell ratios, and reduced PHA responses when infected. Compared to adolescents, younger children showed lower antibody titers and weaker cellular responses to SARS-CoV-2, possibly underlining the higher prevalence of severe manifestations in younger children. Our study illustrates important age-, gender-, and disease severity-dependent variations in immune responses to SARS-CoV-2, which can be helpful in improving patient management and immunization strategies adjusted to age groups. Full article

Pseudorabies virus (PRV), a highly pathogenic alphaherpesvirus, poses a potential threat to public health and safety due to its broad host range and risk of cross-species transmission. Viruses have evolved multiple strategies to exploit host factors for entry into and survival in host cells. Drebrin is an actin-binding protein that restricts rotavirus entry by inhibiting dynamin-mediated endocytosis. However, its role and mechanism in DNA virus infection, particularly in herpesviruses, remain unexplored. In this study, we investigated the role of Drebrin in PRV infection using pharmacological inhibition (BTP−2) and CRISPR-Cas9-mediated gene knockout. Both the Drebrin inhibitor BTP−2 and gene knockout significantly suppressed PRV replication. Intriguingly, Drebrin exhibited stage-specific effects on the viral life cycle: its inhibition enhanced viral internalization during early infection but impaired viral replication at later stages, suggesting that Drebrin plays a complex role in the regulation of PRV infection. PRV infection partially disrupted actin stress fibers and caused an increase in cell size. Drebrin knockout also altered the host-cell morphology, reduced the cell surface area, and induced actin cytoskeleton rearrangement, which was further modulated in PRV-infected cells. In summary, our data demonstrate that Drebrin functions as a critical host factor governing the entire PRV life cycle by regulating actin cytoskeleton reorganization. Full article

Objectives: The aim of the present study was to better understand the antibody concentrations in healthcare workers (HCWs) from a hospital in Mexico City with a high density of COVID-19 patients. Methods: Up to 243 HCWs were recruited in 2020 and 2022 and were sorted into three groups: hybrid immunity (HI, natural infection plus vaccination), vaccine-induced immunity (VI), and unvaccinated but RT-qPCR negative at the beginning of the pandemic (UV). Peripheral blood and nasopharyngeal swab samples were obtained; additionally, saliva samples were obtained from the UV group. The titers of IgG, IgM, and IgA against the SARS-CoV-2 receptor-binding domain (RBD) and nucleocapsid (NCP) proteins were assessed using an in-house ELISA, and positivity to the virus was determined via RT-qPCR. Results: Most HI and VI participants were positive for serum anti-RBD IgG (92.8% and 100%, respectively), while 26.6% (for HI) and 19% (for VI) were positive for anti-NCP IgG. Regarding serum anti-RBD IgA, the VI and HI groups had positive rates of 87.3% and 66%, respectively. In contrast, the UV group showed a rate of 5.7% but the positivity for IgA in saliva was higher (52% for RBD and 35% for NCP). In addition, the highest antibody titers were obtained for anti-RBD IgG and IgA in the HI and VI groups, respectively. In saliva, the IgA antibody titer was higher for the RBD antigen (1:1280). Conclusions: These results strengthen our understanding of antibody concentrations in HCWs during two critical years of the pandemic in a general hospital with many COVID-19 patients. Full article

Deoxyshikonin (DS) is a derivative of shikonin, the main compound present in Lithospermi radi, the root of Lithospermum erythrorhizon Siebold and Zucc. In this study, we investigated the antiviral effects of DS using Influenza A/PR8/34, which expresses green fluorescent protein (GFP) as well as wild-type PR8/34 H1N1 Influenza A virus (IAV). Fluorescence microscopy and flow cytometry results showed that DS from 1.25 to 5 µM significantly and dose-dependently inhibited PR8-GFP IAV infection. A plaque assay confirmed the inhibitory effect of DS against H1N1 IAV infection. Consistently, immunofluorescence results showed that DS suppresses IAV protein expression. Time-of-drug-addition and hemagglutination inhibition assays revealed that DS exhibits anti-influenza virus efficacy by blocking the viral attachment and penetration into the cells and has a direct virus-eradication effect in the early stages of infection. However, DS did not repress neuraminidase activity. Our findings suggest that DS could be used not only to protect against the early stages of IAV infection, but also to treat influenza virus infections in combination with NA inhibitors. Full article