Search Results (468)

The induction of type I interferon (IFN) via intracellular nucleic acid sensors may be useful in preventing viral infections. However, little is known about the effect of natural plant materials on sensor responses. We previously found that cardamom (Elettaria cardamomum (L.) Maton) seed extract (CSWE) enhanced type I IFN expression and prevented influenza virus infection. In this study, we investigated the effect of CSWE on type I IFN responses using intracellular nucleic acid sensor molecules. Human lung epithelial A549 cells were treated with CSWE and transfected with poly(dA:dT) or poly(I:C) using lipofection. CSWE and 1,8-cineole, the major CSWE components, dose-dependently induced type I IFNs and IFN-stimulated genes in both poly(dA:dT)- and poly(I:C)-transfected A549 cells. The type I IFN-enhancing effect of CSWE was dependent on the stimulator of interferon genes (STING), whereas the effect of 1,8-cineole was independent of STING and mediated by the down-regulation of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-inducible poly-ADP-ribose polymerase expression. Our study suggests that CSWE has the potential to act as a beneficial antiviral agent by enhancing homeostatic type I IFN production. Full article

Vaccination is the most effective method to counteract infectious diseases in farmed fish. It secures aquaculture production and safeguards the wild stock and aquatic ecosystem from catastrophic contagious diseases. In vaccine development, recombinant subunit vaccines are favorable candidates since they can be economically produced in large quantities without growing many pathogens, as in inactivated or attenuated vaccine production. However, recombinant subunit vaccines are often weak or deficient in immunogenicity, resulting in inadequate defenses against infections. Technologies that can increase the immunogenicity of recombinant subunit vaccines are in desperate need. Enhanced green fluorescence protein (EGFP) has a low antigenicity and is susceptible to folding changes and losing fluorescence after fusing with other proteins. Using these valuable features of EGFP, we comprehend two amphipathic alpha-helical peptides, AH1 and AH3, derived from Hepatitis C virus and Influenza A virus, respectively, that can induce high immune responses of their fused EGFP in fish without affecting their folding. AH3-EGFP has the most elevated cell binding, significantly 62% and 36% higher than EGFP and AH1-EGFP, respectively. Immunizations with AH1-EGFP or AH3-EGFP significantly induced higher anti-EGFP antibody levels 300–500-fold higher than EGFP immunization after the boost injection in rainbow trout. Our results suggest that AH1 and AH3 effectively increase the immunogenicity of EGFP without influencing its structure. Further validation of their value in other recombinant proteins is necessary to demonstrate their broader utility in enhancing the immunogenicity of subunit vaccines. We also suggest that EGFP and its variants are promising candidates for initially screening proper immunogenicity-enhancing peptides or proteins to advance recombinant subunit vaccine development. Full article

Schizophrenia is a challenging multifactorial neuropsychiatric disease that involves interactions between genetic susceptibility and environmental insults. Increasing evidence implicates viral infections as significant environmental contributors, particularly during sensitive neurodevelopmental periods. This review synthesises current findings on the viral hypothesis of schizophrenia, encompassing a wide array of neurotropic viruses, including influenza viruses, herpesviruses (HSV-1 and 2, CMV, VZV, EBV, HHV-6 and 8), hepatitis B and C viruses, HIV, HERVs, HTLV, Zika virus, BoDV, coronaviruses (including SARS-CoV-2), and others. These pathogens can contribute to schizophrenia through mechanisms such as direct microinvasion, persistent central nervous system infection, immune-mediated neuroinflammation, molecular mimicry, and the disturbance of the blood–brain barrier. Prenatal exposure to viral infections can trigger maternal immune activation, resulting in cytokine-mediated alterations in the neurological development of the foetus that persist into adulthood. Genetic studies highlight the role of immune-related loci, including major histocompatibility complex polymorphisms, in modulating susceptibility to infection and neurodevelopmental outcomes. Clinical data also support the “mild encephalitis” hypothesis, suggesting that a subset of schizophrenia cases involve low-grade chronic neuroinflammation. Although antipsychotics have some immunomodulatory effects, adjunctive anti-inflammatory therapies show promise, particularly in treatment-resistant cases. Despite compelling associations, pathogen-specific links remain inconsistent, emphasising the need for longitudinal studies and integrative approaches such as viromics to unravel causal relationships. This review supports a “multi-hit” model in which viral infections interfere with hereditary and immunological susceptibilities, enhancing schizophrenia risk. Elucidating these virus–immune–brain interactions may facilitate the discovery of biomarkers, targeted prevention, and novel therapeutic strategies for schizophrenia. Full article

Surveillance of swine influenza A virus (swIAV) traditionally focuses on respiratory matrices, yet emerging evidence suggests that fecal shedding and secondary environmental contamination may also contribute to viral dissemination. In this study, we collected and analyzed nasal, rectal, environmental, milk, and colostrum samples from naturally infected pigs in a commercial farm in Minas Gerais, Brazil. IAV RNA was detected in 25% of samples, including 42% from asymptomatic animals, with nasal swabs showing higher detection rates (30%) than rectal swabs (20%), though rectal Ct values were consistently higher, indicative of lower viral loads. We successfully isolated viable viruses from feces and effluent samples. Whole-genome sequencing revealed co-circulation of enzootic pH1N1 clade #2 (HA) and pN1 clade #4 (NA), alongside human-origin H3N2 sequences clustering within clade 3C.2a1b.2a.2a.1, and N2 segments related to pre-3C human lineages from 2001 to 2002. Phylogenetic and p-distance analyses support both recent reverse zoonosis and historical transmission events. Detection of complete HA/NA sequences from rectal swabs and treated effluent further emphasizes the surveillance value of non-respiratory matrices. The integration of respiratory and fecal/environmental sampling appears important to achieve more comprehensive IAV monitoring in swine herds and may have significant implications for One Health strategies in Brazil and beyond. Full article

Background/Objectives: Since the World Health Organization (WHO) recommended HIV self-testing as an alternative to traditional facility-based testing in 2016, it has been increasingly adopted worldwide. This study aimed to evaluate the performance of the ConfiSign HIV Self-Test (GenBody Inc., Republic of Korea), a newly developed blood-based immunochromatographic assay for the qualitative detection of total antibodies (IgG and IgM) against HIV-1/HIV-2. Methods: The evaluation included four components: (1) retrospective analysis of 1400 archived serum samples (400 HIV-positive and 1000 HIV-negative samples), (2) prospective self-testing by 335 participants (112 HIV-positive participants and 223 individuals with an unknown HIV status, including healthy volunteers), (3) assessment using seroconversion panels and diverse HIV subtypes, and (4) analytical specificity testing for cross-reactivity and interference. The Elecsys HIV combi PT and Alinity I HIV Ag/Ab Combo assays were used as reference assays. Results: In retrospective testing, the ConfiSign HIV Self-Test achieved a positive percent agreement (PPA) of 100%, a negative percent agreement (NPA) of 99.2%, and a Cohen’s kappa value of 0.986, showing excellent agreement with the reference assays. In the prospective study, the test showed 100% sensitivity and specificity, with a low invalid result rate of 1.8%. All HIV-positive samples, including those with low signal-to-cutoff (S/Co) values in the Alinity I assay, were correctly identified. The test also reliably detected early seroconversion samples and accurately identified a broad range of HIV-1 subtypes (A, B, C, D, F, G, CRF01_AE, CRF02_AG, and group O) as well as HIV-2. No cross-reactivity or interference was observed with samples that were positive for hepatitis viruses, cytomegalovirus, Epstein–Barr virus, varicella zoster virus, influenza, HTLV-1, HTLV-2, or malaria. Conclusions: The ConfiSign HIV Self-Test demonstrated excellent sensitivity, specificity, and robustness across diverse clinical samples, supporting its reliability and practicality as a self-testing option for HIV-1/2 antibody detection. Full article

Avian influenza virus (AIV) remains a persistent threat to both the poultry industry and human health. Among the AIV subtypes posing public health threats, H7N9 AIV is responsible for five epidemic waves of human infection in China. Here, a detection system based on a mouse model was established, which can simultaneously and quantitatively analyze the dynamic changes in the viral genomic RNA (vRNA), complementary RNA (cRNA), and messenger RNA (mRNA) of H7N9 AIV by using reverse transcription primers with tag sequences to reverse transcribe the three species of RNAs into corresponding cDNA templates, which are then absolutely quantified using the TaqMan quantitative PCR method. This system specifically targets the PB2 and NA genes and, for the first time, enables a spatiotemporal analysis of all three viral RNA species within an animal model. Our results revealed that H7N9 AIV exhibits characteristic replication kinetics, with all three species of viral RNAs showing a rapid increase followed by a certain degree of decline. This system offers a powerful tool for us to further advance our understanding of the replication dynamics of AIV in mice. Full article

Polyphenols are structurally diverse plant metabolites that have attracted significant interest. Their compositions are versatile, depending on their structures, including the number of rings in the polyphenol composition. Based on these attributes, polyphenols can be classified as flavanols, anthocyanins, flavones, phenolic acids, stilbenes, and lignans. Polyphenols mainly possess inhibition of viral replication, interference with viral protein synthesis, and modulation of immune responses, providing significant antiviral effects against several viruses, including herpes simplex virus, hepatitis C virus, and influenza. They are crucial for medical compounds in diverse, versatile treatments, namely in diabetes, cardiovascular disorders, cancer, and neurodegenerative problems. Plants are the primary source of bioactive molecules, which are valued for their anti-inflammatory, antioxidant, anticancer, and antiviral activities. Especially, polyphenols are extracted as the most abundant bioactive compounds of plants. Moreover, viral infections are one of the major factors in illnesses and diseases, along with bacteria and fungi. Numerous in vitro and in vivo studies report antiviral activity against SARS-CoV-2, Mayaro virus, dengue virus, herpesvirus, and influenza A virus, though clinical validation remains limited. Additionally, inhibition of viral entry, interference with viral replication, modulation of host immune response, and direct virucidal effects were examined. Full article

Highly pathogenic avian influenza (HPAI) H5N1 continues to pose a major threat to animal and public health. Since its emergence, clade 2.3.4.4b has become the dominant global lineage, associated with widespread outbreaks in Europe. This study aimed to characterise the H5N1 strains detected in backyard chickens in Serbia and investigate their phylogenetic and phylogeographic relationships with historical and currently circulating strains in Serbia and the broader region. Samples collected in 2024 were tested by qRT-PCR, and positive samples were propagated in MDCK cells. Whole genome sequencing of isolated virus was performed using the MinION Mk1C platform (ONT, Oxford, UK). Bayesian phylogenetic and phylogeographic analyses were conducted using BEAST X and SPREAD3 v.9.6. The results revealed three independent introductions of H5N1 into Serbia between 2020 and 2024. The spatiotemporal diffusion patterns confirmed both north–south and west–east viral spread from Northern and Central Europe into the Balkans. Additionally, Serbia was identified as a critical transit and divergence point in the regional transmission network, highlighting its role in the spread of H5N1 between Western and Eastern Europe. These findings underscore the importance of continued genomic surveillance in both domestic and wild bird populations to better understand and reduce HPAI spread. Full article

Viruses encode ion channel proteins called viroporins to assist in infection and immune evasion. The alphavirus 6K protein is classified as a member of the viroporin family of proteins. Several studies have characterized the role of 6K in alphavirus budding and infection since its discovery in the late 1970s. In this review, we summarize 6K research and discuss some unanswered questions regarding 6K biology. We highlight the similarities and differences between 6K and viroporins of clinically relevant viruses—influenza A virus, HIV-1, hepatitis C virus, and SARS-CoV-2—and address their importance as therapeutic targets. The sensitivity of these viroporins to common inhibitors and their ability to functionally complement each other underscore their potential as targets for broad-spectrum antiviral therapies. Full article

This study explored the distribution and genetic characteristics of respiratory pathogens in outpatients with acute respiratory infections (ARIs) in Yangon, Myanmar, during the 2023 rainy season. Among 267 patients who tested negative for influenza, RSV, and SARS-CoV-2 using rapid diagnostic tests, 84.6% were positive for at least one pathogen according to a multiplex polymerase chain reaction (PCR) assay, the BioFire^® FilmArray^® Respiratory Panel 2.1. The most common viruses detected were rhinovirus/enterovirus (RV/EV) at 37.8%, respiratory syncytial virus (RSV) at 22.4%, and human metapneumovirus (hMPV) at 10.0%. These pathogens co-circulated mainly from July to September, with RV/EV consistently predominant. Symptom comparison among RV/EV-, RSV-, and hMPV-infected patients showed similar clinical features, though fever was more common in hMPV cases. Among RV/EV-positive patients, 59.3% had single infections, while 40.7% experienced co-infections, especially with RSV and adenovirus. Genotyping identified 28 types from five species, primarily RV-A and RV-C, which were genetically diverse. One EV-D68 case was also found, emphasizing its potential risk. This study underscores the genetic diversity and clinical impact of RV/EV and stresses the importance of ongoing molecular surveillance in Myanmar’s post-COVID-19 context to inform effective public health responses. Full article

Previously, we developed a porcine bronchial epithelial cell line designated as PBE cells and demonstrated that this cell line possesses functional Toll-like receptor 3 (TLR3), triggering the expressions of interferons (IFNs), antiviral factors, and inflammatory cytokines after its stimulation with the synthetic double-stranded ARN poly(I:C). In this work, we aimed to further characterize the PBE cell line as a reliable in vitro model for investigating swine influenza virus (SIV) infection and immunity. We evaluated the capacity of two SIV subtypes, H1N1 and H3N2, to replicate and induce cytopathic effects in PBE cells and to modulate the expressions of IFNs, antiviral factors, inflammatory cytokines, and negative regulators of the TLR signaling. We demonstrated that PBE cells are susceptible to both H1N1 and H3N2. SIV infected PBE cells inducing notable cytopathic effects as shown by the alteration of transepithelial electrical resistance (TEER) and cilia. Both SIV subtypes replicated in PBE cells in similar proportion and altered TEER values in comparable magnitudes. However, SIV H3N2 induced higher alterations of cilia than H1N1. SIV infection induced changes in all the immune factors evaluated in PBE cells. We detected quantitative differences when the subtypes H1N1 and H3N2 were compared. The fold expression changes of IFN-β, Mx1, Mx2, IFITM1, OAS1, OAS2, and OASL were higher in PBE cells infected with H3N2 than in cells challenged with H1N1. In addition, although both subtypes stimulated IL-8 expression, only the H3N2 induced IL-6 in infected PBE cells. SIV H1N1 and H3N2 also upregulated the expressions of the negative regulators A20, BCL-3, and MKP-1, while only H1N1 increased SIGIRR and Tollip. Immortalized respiratory cell lines from pigs can be useful in vitro systems for the study of viral infections and immune responses. These studies are of importance in the context of influenza infections not only for the agricultural field because pigs are natural hosts of these viruses but also because these animals serve as intermediate reservoirs of viruses that can threaten humans’ health. We demonstrated here that the PBE cell line can be a useful in vitro model to study SIV infection and immunity. Full article

Cyanohydrin synthesis, as the simplest preparative method for introducing a carboxyl group into a piperidine molecule, has been used to obtain potentially biologically active piperidinecarboxylic acids, which have alkyl and arylalkyl radicals at the nitrogen atom of the piperidine ring. Hydrochlorides of cyclopropanecarboxylic acid esters based on piperidinecarboxylic acids, as well as hydrochlorides of fluorobenzoic acid esters of N-substituted piperidines, have been synthesized. The purpose of this study was to search for antiviral drugs among new piperidine derivatives. The structure of the synthesized compounds was studied by NMR methods, including COSY (¹H-¹H), HMQC (¹H-¹³C) and HMBC (¹H-¹³C) techniques. The values of chemical shifts, multiplicities, and integrated intensities of ¹H and ¹³C signals in one-dimensional NMR spectra were determined. The results of COSY (¹H-¹H), HMQC (¹H-¹³C), and HMBC (¹H-¹³C) revealed homo- and heteronuclear interactions, confirming the structure of the studied compounds. The antiviral and cytotoxic activities of the synthesized compounds were studied. The antiviral activity in vitro was determined according to the therapeutic regimen against the influenza A/Swine/Iowa/30 (H1N1) virus on the MDCK cell model. The cytotoxicity of the studied substances in vitro was assessed using the MTT test. Based on the results of the antiviral activity against the influenza A virus, it can be concluded that all substances are effective against the influenza A/H1N1 virus compared to the commercial preparations Tamiflu and Rimantadine. Full article

Background/Objectives:H5N1 influenza viruses are spreading worldwide and threaten global public health. Preparedness is necessary to mitigate the worst-case scenario should an H5N1 influenza pandemic occur and justify the development of vaccines against circulating H5N1 viruses of concern. Methods: The production and characterization of egg-based split and inactivated H5Nx of three distinct monovalent antigens from clades 2.3.4.4b, 2.3.2.1c, and 2.3.4 were performed at an industrial scale. These antigens were formulated and their immune responses, when combined or not with IB160 squalene-based oil-in-water emulsion adjuvant in a rat model, were evaluated in a one- or two-dose immunization schedule. IgG antibodies, hemagglutination inhibitions, and microneutralization titers were measured for vaccine-induced immunity and cross-reactivity. Results: Three monovalent vaccines from clades 2.3.4.4b, 2.3.2.1c, and 2.3.4 were produced at an industrial scale and characterized. The immune responses against the monovalent vaccines showed a clade-specific antibody response and the need to combine with IB160 adjuvant for a required immune response. Conclusions: Considering the candidate vaccine viruses (CVVs) with the testing potency reagents available and that the antibody response obtained against the CVVs produced was clade-specific, IDCDC RG-71A is the indicated CVV for the predominant currently circulating H5N1 influenza virus of clade 2.3.4.4b and must be combined with adjuvant to induce a higher and efficacious immune response in a two-dose immunization protocol. Full article

The avian influenza virus, particularly the highly pathogenic H5N1 subtype, represents a significant public health threat due to its interspecies transmission potential and growing resistance to current antiviral therapies. To address this, the identification of novel and effective neuraminidase (NA) inhibitors is critical. In this study, an integrated in silico strategy was employed, beginning with the generation of an energy-optimized pharmacophore model (e-pharmacophore, ADDN) based on the reference inhibitor Zanamivir. A virtual screening of 47,781 natural compounds from the PubChem database was performed, followed by molecular docking validated through an enrichment assay. Promising hits were further evaluated via ADMET predictions, density functional theory (DFT) calculations to assess chemical reactivity, and molecular dynamics (MD) simulations to examine the stability of the ligand–protein complexes. Three lead compounds (C1: CID 102209473, C2: CID 85692821, and C3: CID 45379525) demonstrated strong binding affinity toward NA. Their ADMET profiles predicted favorable bioavailability and low toxicity. The DFT analyses indicated suitable chemical reactivity, particularly for C2 and C3. The MD simulations confirmed the structural stability of all three ligand–NA complexes, supported by robust and complementary intermolecular interactions. In contrast, Zanamivir exhibited limited hydrophobic interactions, compromising its binding stability within the active site. These findings offer a rational foundation for further experimental validation and the development of next-generation NA inhibitors derived from natural sources. Full article

Background: Self-administered orally dissolving films (ODFs) encapsulating inactivated influenza vaccines represent an effective strategy for stimulating mucosal immunity. While this vaccination method offers several advantages over conventional influenza vaccines, a comparative efficacy study remains lacking. Methods: Female BALB/c mice were immunized with inactivated A/PR/8/34 (H1N1) either via orogastric inoculation or through the oral mucosal delivery using pullulan and trehalose-based ODF vaccines. Each group received equivalent antigen doses across three immunizations. Humoral responses and antibody functionality were assessed using sera collected post-immunization. After lethal viral challenge, other immunological and virological parameters were determined in corresponding tissues. Body weight and survival were monitored over a 14-day period after challenge. Results: ODF vaccination elicited significantly higher virus-specific IgA levels, HAI titers, and neutralizing antibody activity than oral gavage. After the viral challenge, ODF-immunized mice exhibited stronger IgG and IgA responses in respiratory tissues, increased antibody-secreting cells in lungs and spleen, and elevated germinal center B cells and CD8⁺ T cell responses. Both vaccination methods reduced lung pro-inflammatory cytokines and provided full protection against lethal challenge; however, the ODF group showed lower cytokine levels, better weight maintenance, and reduced viral loads. Conclusions: ODF vaccination elicits more robust systemic and mucosal immune responses than oral vaccination and may serve as a promising alternative method of influenza vaccine delivery. Full article