Search Results (421)

DNA connects the domains of genetic regulation and environmental interactions and plays a crucial role in neural development and cognitive function. The complex roles of genetic and epigenetic processes in brain development, synaptic plasticity, and higher-order cognitive abilities were reviewed in this study. Neural progenitors are formed and differentiated according to genetic instructions, whereas epigenetic changes, such as DNA methylation, dynamically control gene expression in response to external stimuli. These processes shape behavior and cognitive resilience by influencing neural identity, synaptic efficiency, and adaptation. This review also examines how DNA damage and repair mechanisms affect the integrity of neurons, which are essential for memory and learning. It also emphasizes how genetic predispositions and environmental factors interact to determine a person’s susceptibility to neurodegenerative disorders, such as Parkinson’s and Alzheimer’s diseases. Developments in gene-editing technologies, such as CRISPR, and non-viral delivery techniques provide encouraging treatment avenues for neurodegenerative disorders. This review highlights the fundamental role of DNA in coordinating the intricate interactions between molecular and environmental factors that underlie brain function and diseases. Full article

The rabies virus (RABV) phosphoprotein (P protein) has multiple functions, including acting as the essential non-catalytic cofactor of the viral polymerase (L protein) for genome replication and transcription; the principal viral antagonist of the interferon (IFN)-mediated innate immune response; and the chaperone for the viral nucleoprotein (N protein). Although P protein is known to undergo phosphorylation by cellular kinases, the location and functions of the phosphorylation sites remains poorly defined. Here, we report the identification by mass-spectrometry (MS) of residues of P protein that are modified by phosphorylation in mammalian cells, including several novel sites. Analysis of P protein with phospho-mimetic and phospho-inhibitory mutations of three novel residues/clusters that were commonly identified by MS (Ser48, Ser183/187, Ser217/219/220) indicate that phosphorylation at each of these sites does not have a major influence on nuclear trafficking or antagonistic functions toward IFN signalling pathways. However, phosphorylation of Ser48 in the N-terminus of P protein impaired function in transcription/replication and in the formation of replication structures that contain complexes of P and N proteins, suggestive of altered interactions of these proteins. The crystal structure of P protein containing the S48E phospho-mimetic mutation indicates that Ser48 phosphorylation facilitates the binding of residues 41–52 of P protein into the RNA-binding groove of non-RNA-bound N protein (N⁰), primarily through the formation of a salt bridge with Arg434 of N protein. These data indicate that Ser48 modification regulates the cycling of P-N⁰ chaperone complexes that deliver N protein to RNA to enable transcription/replication, such that enhanced interaction due to S48E phospho-mimetic mutation reduces N protein delivery to the RNA, inhibiting subsequent transcription/replication processes. These data are, to our knowledge, the first to implicate phosphorylation of RABV P protein in conserved replication functions of the P gene. Full article

Porcine reproductive and respiratory syndrome virus remains one of the most economically significant pathogens in swine production, with PRRSV-2 being the dominant variant in the United States. While lineage classification has traditionally relied on ORF5 sequencing, recent studies suggest that this single-gene approach may overlook key evolutionary events such as recombination. In this study, we performed whole-genome sequencing and phylogenetic analysis of seven PRRSV-2 isolates collected in the U.S. between 2006 and 2024. Using reference-guided assembly, lineage assignment, and recombination detection with RDP5 and SIMplot, we identified discordant phylogenetic placements between ORF5 and whole genomes in four of the seven isolates. These discordances were explained by multiple recombination events affecting different genomic regions, particularly ORF2–ORF7. In contrast, three isolates showed phylogenetic concordance and no strong evidence of recombination. Our findings demonstrate that recombination plays a significant role in shaping PRRSV-2 evolution and highlight the limitations of ORF5-based lineage classification. Whole-genome surveillance is therefore essential to accurately track viral diversity, detect recombinant strains, and inform control strategies. This work underscores the need for a broader adoption of full-genome analysis in routine PRRSV surveillance and research. Full article

Viral infections and their vector dynamics pose a major threat to potatoes (Solanum tuberosum L.) worldwide, urgently needing an integrated understanding of the molecular and ecological interactions in this tripartite system. This review describes the major potato viruses, namely potato virus Y (PVY), the potato leafroll virus (PLRV), and potato virus X (PVX), with an emphasis on their infection and replication strategies in plants, as well as their movement within them. It also discusses plant responses to these viruses by uncovering RNA silencing, resistance (R) genes, and hormonal signaling. The complex dynamics of virus–vector interactions are discussed, considering the modes of transmission-persistent, non-persistent and semi-persistent—the role of viral proteins such as HC-Pro in determining vector specificity and adaptations in vectors that facilitate virus dissemination. This article discusses how vectors select potato plants, with an emphasis on the role played by plant-excreted volatiles and vector-applied saliva in plant defense. It also discusses host genes that contribute to vector resistance. This review provides an overview of the interactions between potato plants, viruses, and vectors and shows how viruses influence plant–vector interactions, the molecular pathways shared, and the altered gene expression profiles due to these interactions. The review offers an integrated perspective essential for developing sustainable and precise control strategies against potato viral pathogens under changing climatic conditions. Full article

The global impact of the COVID-19 crisis has underscored the need for novel therapeutic candidates capable of efficiently targeting essential viral proteins. Existing therapeutic strategies continue to encounter limitations such as reduced efficacy against emerging variants, safety concerns, and suboptimal pharmacodynamics, which emphasize the potential of natural-origin compounds as supportive agents with immunomodulatory, anti-inflammatory, and antioxidant benefits. The present study significantly advances prior molecular docking research through comprehensive virtual screening of structurally related analogs derived from antiviral phytochemicals. These compounds were evaluated specifically against the SARS-CoV-2 main protease (3CLpro) and papain-like protease (PLpro). Utilizing chemical similarity algorithms via the ChEMBL database, over 600 candidate molecules were retrieved and subjected to automated docking, interaction pattern analysis, and comprehensive ADMET profiling. Several analogs showed enhanced binding scores relative to their parent scaffolds, with CHEMBL1720210 (a shogaol-derived analog) demonstrating strong interaction with PLpro (−9.34 kcal/mol), and CHEMBL1495225 (a 6-gingerol derivative) showing high affinity for 3CLpro (−8.04 kcal/mol). Molecular interaction analysis revealed that CHEMBL1720210 forms hydrogen bonds with key PLpro residues including GLY163, LEU162, GLN269, TYR265, and TYR273, complemented by hydrophobic interactions with TYR268 and PRO248. CHEMBL1495225 establishes multiple hydrogen bonds with the 3CLpro residues ASP197, ARG131, TYR239, LEU272, and GLY195, along with hydrophobic contacts with LEU287. Gene expression predictions via DIGEP-Pred indicated that the top-ranked compounds could influence biological pathways linked to inflammation and oxidative stress, processes implicated in COVID-19’s pathology. Notably, CHEMBL4069090 emerged as a lead compound with favorable drug-likeness and predicted binding to PLpro. Overall, the applied in silico framework facilitated the rational prioritization of bioactive analogs with promising pharmacological profiles, supporting their advancement toward experimental validation and therapeutic exploration against SARS-CoV-2. Full article

Tomato yellow leaf curl virus (TYLCV) is a highly destructive pathogen of global tomato crops. The open reading frame (ORF) of TYLCV V2 contains two initiation codons (ATG1/V2-1 and ATG2/V2-2), producing distinct protein isoforms. Using custom antibodies, we confirmed V2-1 and V2-2 expression in infected Nicotiana benthamiana and tomato plants. Deletion mutants revealed their specialized roles: V2-1 was indispensable for viral replication and systemic spread—its loss severely reduced pathogenicity and genome accumulation. V2-2 acted as an auxiliary factor, and its deletion attenuated symptoms but kept the virus infection. Host-specific effects were observed—V2-1 deletion led to lower viral DNA/coat protein levels in N. benthamiana than in tomato, suggesting host-dependent regulation. Mutant viruses declined progressively in tomato, indicating host defense clearance. Heterologous co-expression of both isoforms via potato virus X induced systemic necrosis in N. benthamiana, demonstrating functional synergy between isoforms. Both initiation codons were essential for V2-mediated suppression of transcriptional gene silencing (TGS) and post-transcriptional gene silencing (PTGS). This study uncovers the mechanistic divergence of V2 isoforms in TYLCV infection, highlighting their collaborative roles in virulence and host manipulation. The findings advance understanding of geminivirus coding complexity and offer potential targets for resistance strategies. Full article

Tomato leaf curl New Delhi virus (ToLCNDV) is among the most prevalent and widely distributed begomovirus infecting chili pepper (Capsicum annuum) and tomato in the Indian subcontinent. In this study, a guide RNA (gRNA) sequence-CRISPR-Cas9 approach was used to target and cleave two essential coding regions in the begomovirus genome. The gRNAs were designed to target conserved regions of the ToLCNDV replication-associated protein (rep) gene or ORF AC1, and/or the coat protein (cp) gene or AV1 ORF, respectively. Based on an alignment of 346 representative ToLCNDV genome sequences, all predicted single nucleotide polymorphisms off-target sites were identified and eliminated as potential gRNA targets. Based on the remaining genome regions, four candidate gRNAs were designed and used to build gRNA-Cas9 duplexed constructs, e.g., containing two gRNAs cloned in tandem, in different combinations (1–4). Two contained two gRNAs that targeted the coat protein gene (cp; AV1 ORF), while the other two constructs targeted both the cp and replication-associated protein gene (rep; AC1 ORF). These constructs were evaluated for the potential to suppress ToLCNDV infection in Nicotiana benthamiana plants in a transient expression-transfection assay. Among the plants inoculated with the duplexed gRNA construct designed to cleave ToLCNDV-AV1 or AC1-specific nucleotides, the construct designed to target both the cp (293–993 nt) and rep (1561–2324) showed the greatest reduction in virus accumulation, based on real-time quantitative PCR amplification, and attenuated disease symptoms, compared to plants inoculated with the DNA-A component alone or mock-inoculated, e.g., with buffer. The results demonstrate the potential for gRNA-mediated suppression of ToLCNDV infection in plants by targeting at least two viral coding regions, underscoring the great potential of CRISPR-Cas-mediated abatement of begomovirus infection in numerous crop species. Full article

Over the past decade, diseases associated with fowl adenoviruses (FAdVs) have exhibited a new epidemic trend worldwide. The presence of numerous FAdVs serotypes, combined with the virus’s broad host range, positions it as a significant pathogen in the poultry industry. In the current context of intensive poultry production and global trade, co-infections involving multiple FAdVs serotypes, as well as co-infections with FAdVs alongside infectious bursal disease or infectious anemia virus, may occur within the same region or even on the same farm. The frequency of these outbreaks complicates the prevention and control of FAdVs. Therefore, the development of effective, targeted vaccines is essential for providing technical support in the management of FAdVs epidemics. Ongoing vaccine research aims to improve vaccine efficacy and address the challenges posed by emerging FAdVs outbreaks. This review focuses on vaccines developed and studied worldwide for various serotypes of FAdVs in the past decade. It encompasses inactivated vaccines, live attenuated vaccines, e.g., host-adapted attenuated vaccines and gene deletion vaccines, viral vector vaccines, and subunit vaccines (including VLP proteins and chimeric proteins). The current limitations and future development directions of FAdVs vaccine development are also proposed to provide a reference for new-generation vaccines and innovative vaccination strategies against FAdVs, as well as for the rapid development of highly effective vaccines. Full article

Background and Clinical Significance: Herein, we describe the clinical case of a 17-year-old patient with psychotic disorder secondary to cerebral venous thrombosis due to primary thrombophilia, which was related to protein S deficiency and a heterozygous MTHFR gene mutation with the p.Ala222Val variant. Case presentation: A 17-year-old female, with no history of previous illnesses, was admitted to the emergency service department due to a psychotic break. Psychiatric evaluation detected disorganized thought, euphoria, ideas that were fleeting and loosely associated, psychomotor excitement, and deviant judgment. On the fifth day, an inflammatory process in the parotid gland was detected, pointing out a probable viral meningoencephalitis, prompting antiviral and antimicrobial treatment. One week after antiviral and steroidal anti-inflammatory treatments, the symptoms’ improvement was minimal, which led to further neurological workup. MRI venography revealed a filling defect in the transverse sinus, consistent with cerebral venous thrombosis. Consequently, anticoagulation treatment with enoxaparin was initiated. The patient’s behavior improved, revealing that the encephalopathic symptoms were secondary to thrombosis of the venous sinus. Hematological studies indicated the cause of the venous sinus thrombosis was a primary thrombophilia caused by a heterozygous MTHFR mutation variant p.Ala222Val and a 35% decrease in plasmatic protein S. Conclusions: This case highlights the possible relationship between psychiatric and thrombotic disorders, suggesting that both the MTHFR mutation and protein S deficiency could lead to psychotic disorders. Early detection of thrombotic risk factors in early-onset psychiatric disorders is essential for the comprehensive management of patients. Full article

Background: Human herpesviruses are double-stranded DNA viruses of which eight types have been identified at present. Herpesvirus infection comprises an active lytic phase and a lifelong latency phase with the possibility of reactivation. These infections are highly prevalent worldwide and can lead to a broad spectrum of clinical manifestations, ranging from mild symptoms to severe disease, particularly in immunocompromised individuals. Clustered regularly interspaced palindromic repeats (CRISPR)-based therapy is an interesting alternative to current antiviral drugs, which fail to cure latent infections and are increasingly challenged by viral resistance. Objective: This scoping review aimed to summarize the current state of CRISPR-based antiviral strategies against herpesvirus infections, highlighting the underlying mechanisms, study design and outcomes, and challenges for clinical implementation. Design: A literature search was conducted in the databases PubMed and Web of Science, using both a general and an individual approach for each herpesvirus. Results: This scoping review identified five main mechanisms of CRISPR-based antiviral therapy against herpesvirus infections in vitro and/or in vivo. First, CRISPR systems can inhibit the active lytic replication cycle upon targeting viral lytic genes or host genes. Second, CRISPR technologies can remove latent viral genomes from infected cells by targeting viral genes essential for latency maintenance or destabilizing the viral genome. Third, reactivation of multiple latent herpesvirus infections can be inhibited by CRISPR-Cas-mediated editing of lytic viral genes, preventing a flare-up of clinical symptoms and reducing the risk of viral transmission. Fourth, CRISPR systems can purposefully induce viral reactivation to enhance recognition by the host immune system or improve the efficacy of existing antiviral therapies. Fifth, CRISPR technology can be applied to develop or enhance the efficiency of cellular immunotherapy. Conclusions: Multiple studies demonstrate the potential of CRISPR-based antiviral strategies to target herpesvirus infections through various mechanisms in vitro and in vivo. However, aspects regarding the delivery and biosafety of CRISPR systems, along with the time window for treatment, require further investigation before broad clinical implementation can be realized. Full article

The mammalian immune system, including key components such as toll-like receptors (TLRs), lymphocytes, and cytokines, plays a vital role in defending against diseases. In dogs, genetic polymorphisms and epigenetic regulation of immune-related genes contribute to breed-specific differences in susceptibility or resistance to infectious, autoimmune, and inflammatory diseases. Cytokines, essential for immune cell differentiation and activation, exhibit variable expression among breeds due to genetic factors like single-nucleotide polymorphisms (SNPs) and miRNA regulation. This variability influences immune responses not only to infections but also to chronic inflammatory conditions and cancer, providing insights for improved diagnosis, treatment, and breeding. Selective breeding has further shaped diverse immune phenotypes across breeds, especially through genetic variations in the major histocompatibility complex (MHC) region, which affect vulnerability to immune-mediated and immunodeficiency disorders. Recent studies emphasize the role of specific miRNAs in modulating immune responses during parasitic and viral infections, opening new avenues for precision veterinary medicine and immunotherapy. This review highlights the genetic and epigenetic regulation of immune genes in dogs and explores their potential applications in advancing veterinary diagnostics, therapeutics, and breeding strategies to enhance canine health. Full article

The Highly Pathogenic Avian Influenza Virus (HPAIV) H5 clade 2.3.4.4b has caused severe outbreaks in domestic and wild birds worldwide since its emergence in 2014, and especially since 2020, with outbreaks in Europe and North America. The introduction of the virus into South America was reported for the first time in Colombia in October 2022, followed by outbreaks in other South American countries affecting poultry, wild birds, mammals, and humans. In this study, a phylogenetic and mutation analysis of the hemagglutinin (HA) gene of HPAIV H5N1 2.3.4.4b viruses isolated in South America was performed to analyze its evolution and its transmission and zoonotic potential. The analysis shows an increase in the viral effective population size between April and June 2022, which was followed by multiple outbreaks of HPAIV H5N1 clade 2.3.4.4b in South America. Moreover, the virus variants evolved from a recent common ancestor estimated to have existed in June 2017. The mean rate of evolution of the HA gene was 6.95 × 10⁻³ substitutions per site per year, and the sequence analysis of HA identified a mutation (D171N) located at antibody binding sites and viral oligomerization interfaces, with implications for immune response evasion and new host species infection. Additionally, viral strains from South America share the substitutions L104M, T156A, P181S, and V210A, compared to the vaccine strain A/chicken/Ghana/AVL763/2021. Understanding the dynamics of viral evolution and transmission is essential for effective prevention strategies to mitigate future outbreaks. Full article

In the baculovirus expression system, recombinant viruses generated via bacmids often exhibit reduced expression and genetic stability of target genes during serial passages. This instability is thought to arise from the proximity of non-essential exogenous genes to the target gene insertion site. This study investigated the impact of the target gene insertion locus on its expression and stability within the recombinant viral genome. In addition to the conventional polyhedrin (polh) locus, we evaluated four additional loci located distal to the non-essential exogenous genes. Among them, the ODV-e56 and ChiA/v-cath loci maintained target gene expression and genetic stability more effectively than the polh and p10 loci, even after ten consecutive undiluted viral passages. Notably, essential or functionally important viral genes were located near the ODV-e56 and ChiA/v-cath loci, whereas such genes were absent near the p10 locus. These findings suggest that enhanced stability and expression are associated with the proximity to essential viral genes. Therefore, the strategic selection of target gene insertion sites in close proximity to essential viral elements, rather than simply avoiding non-essential exogenous regions, represents a promising strategy to enhance recombinant protein production in baculovirus expression systems. Full article

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for COVID-19, remains a major global health threat. The virus enters host cells by binding to the angiotensin-converting enzyme 2 (ACE2) receptor. Several small-molecule antiviral drugs, including molnupiravir, favipiravir, remdesivir, and nirmatrelvir have been shown to inhibit SARS-CoV-2 replication and are approved for treating SARS-CoV-2 infections. Nirmatrelvir inhibits the viral main protease (M^pro), a key enzyme for processing polyproteins in viral replication. In contrast, molnupiravir, favipiravir, and remdesivir are prodrugs that target RNA-dependent RNA polymerase (RdRp), which is crucial for genome replication and subgenomic RNA production. However, undergoing extensive metabolism profoundly impacts their therapeutic effects. Carboxylesterases (CES) are a family of enzymes that play an essential role in the metabolism of many drugs, especially prodrugs that require activation through hydrolysis. Molnupiravir is activated by carboxylesterase-2 (CES2), while remdesivir is hydrolytically activated by CES1 but inhibits CES2. Nirmatrelvir and remdesivir are oxidized by the same cytochrome P450 (CYP) enzyme. Additionally, various transporters are involved in the uptake or efflux of these drugs and/or their metabolites. It is well established that drug-metabolizing enzymes and transporters are differentially expressed depending on the cell type, and these genes exhibit significant polymorphisms. In this review, we examine how CES-related cellular and genetic factors influence the therapeutic activities of these widely used COVID-19 medications. This article highlights implications for improving product design, targeted inhibition, and personalized medicine by exploring genetic variations and their impact on drug metabolism and efficacy. Full article

Background: African Swine Fever (ASF) is a viral hemorrhagic disease characterized by diverse clinical and pathological manifestations depending on the virulence of isolates/strains and the immunological status of pigs. The use of modified live viruses (MLVs) is currently the most common approach in developing vaccines against ASF. However, despite the availability of dozens of MLV candidates that meet basic safety and efficacy criteria—such as the absence of severe clinical signs and survival after challenge with a virulent strain—no broadly accepted vaccine has yet been developed. Here, we propose viremia testing as an essential criterion for evaluating candidate ASF vaccines, with levels exceeding 10⁴ HAD₅₀/TCID₅₀ and lasting longer than 21–28 days post vaccination considered unfavorable indicators. Methods: We analyzed ASF MLV vaccines obtained through the deletion of one, two, or more genes, focusing on viremia kinetics after vaccination and challenge with virulent ASFV strains. Post mortem data were used to assess viral persistence in organs. Results: Most MLV candidates, especially those with single-gene deletions, demonstrated relatively high viremia levels after vaccination and challenge. Viral persistence was frequently detected in organs upon necropsy. MLVs with an additional EP402R gene deletion showed low viremia after vaccination but high levels after challenge. Nevertheless, several candidates with favorable viremia profiles were identified, including those obtained via targeted deletions or serial passaging in cell cultures. Conclusions: Incorporating viremia assessment as a primary screening criterion can significantly narrow down the selection of promising MLV candidates and help accelerate the development of effective emergency vaccines for use in ASF-affected regions. Full article