Search Results (113)

Mouse models for “definitive” polyomavirus nephropathy with lytic viral replication and end-organ disease (PyVN) do not exist. We aimed at defining a PyVN model in Black-Swiss mice (n = 126) by injecting newborn animals with murine polyomavirus (strain A2; 1 × 10⁵ plaque forming units) that led in all mice to a productive intrarenal infection with genetically stable, episomal MuPyV lacking latency. Animals were monitored and morphologic, immunohistochemical, molecular, genetic, and immunological analyses were conducted. Results: Within 3–6 weeks peak PyVN developed characterized by acute tubular injury, lytic replication in up to 14% of tubules (mainly collecting ducts/distal nephrons), high viral gene coverage (up to 3589 viral DNA reads/cell equivalent) and RNA expression (up to 9317 VP1-RNA reads/10⁷ RNA reads), inflammation, DNAemia, and-uria. MuPyV doubling times were high early post-infection (urine: 0.17 day–1.61 day) followed by steady slow viral clearance post day 28 (urine, half-life: 9.90 days). By 54 weeks PyVN had morphologically cleared (no chronic tissue injury) with only qPCR evidence of residual MuPyV in 17% of kidneys/mice. Infection induced an IgM/IgG response (peak plasma IgG titer at 7–30 weeks 1:20,480; low IgG titers in 92% of mice at end of follow-up after one year). During infection, episomal MuPyV remained genetically stable, without significant alterations that could have modified the course of PyVN. The mouse model resembles “definitive” PyVN in humans. It is suited for research on the pathogenesis of PyVN including virally induced tubular injury and immunologic interactions. It facilitates in vivo studies of therapeutic interventions aimed at blocking lytic intrarenalPyV replication. Full article

Background/Objectives: Peri-implantitis is a chronic inflammatory condition affecting tissues surrounding dental implants and is characterized by progressive marginal bone loss that can ultimately lead to implant failure. Reduced vascularization and impaired immune clearance in peri-implant tissues contribute to persistent inflammation and limited therapeutic efficacy. MicroRNAs (miRNAs), particularly miR-21, have emerged as key regulators of inflammatory responses and bone remodeling. The objective of this study was to develop a bioactive dental implant coating capable of locally delivering miR-21 to modulate inflammation and promote peri-implant tissue regeneration, thereby preventing peri-implantitis. Methods: Cationic nanoparticles were synthesized using lecithin and low-molecular-weight polyethylenimine (PEI) as a non-viral delivery system for miR-21. Lecithin was employed to enhance biocompatibility, while PEI functionalization provided a positive surface charge to improve miRNA complexation and cellular uptake. The resulting lecithin–PEI nanoparticles (LEC–PEI NPs) were incorporated into a chitosan-based coating and applied to titanium implant surfaces to obtain a sustained miR-21–releasing system (miR21-implant). Transfection efficiency and biological activity were evaluated in human periodontal ligament fibroblasts (hPDLFs) and compared with a commercial transfection reagent (Lipofectamine). Release kinetics and long-term activity of miR-21 from the coating were also assessed. Results: MiR-21-loaded LEC–PEI nanoparticles demonstrated significantly higher transfection efficiency than Lipofectamine and retained marked biological activity in hPDLFs relevant to peri-implantitis prevention. The chitosan-based nanoparticle coating enabled controlled and sustained miR-21 release over time, supporting prolonged modulation of inflammatory and osteogenic signaling pathways involved in peri-implant tissue homeostasis. Conclusions: The miR21-implant system, based on lecithin–PEI nanoparticles incorporated into a chitosan coating, represents a promising therapeutic strategy for peri-implantitis prevention. By enabling sustained local delivery of miR-21, this approach has the potential to preserve peri-implant bone architecture, modulate chronic inflammation, and enhance the osseointegration of titanium dental implants. Full article

Hepatitis B virus (HBV) persists in infected hepatocytes through covalently closed circular DNA (cccDNA), a stable episomal form that serves as the transcriptional template for viral replication. Accurate and sensitive quantification of intrahepatic cccDNA is crucial for evaluating antiviral therapies, particularly those targeting a functional cure. Here, we report the development of a novel, cccDNA-specific detection system combining recombinase polymerase amplification (RPA) with CRISPR/Cas12a-based fluorescence detection. We designed and validated CRISPR RNAs (crRNAs) targeting HBV cccDNA-specific regions conserved across genotypes A–D. Reaction conditions for both RPA and Cas12a detection were optimized to enhance sensitivity, specificity, and accuracy. The system reliably detected as few as 10 copies of cccDNA-containing plasmid per reaction and showed no cross-reactivity with non-cccDNA forms in serum or plasma, indicating assay specificity. When applied to liver tissue samples from 10 HBV-infected and 6 non-HBV patients, the RPA-CRISPR/Cas12a assay exhibited a high sensitivity (90%) and a strong correlation with qPCR results (R² = 0.9155), confirming its accuracy. In the conclusion, the RPA-CRISPR/Cas12a system provides a robust, cost-effective, and scalable platform for sensitive and specific quantification of intrahepatic HBV cccDNA. This method holds promises for research and high-throughput therapeutic screening applications targeting cccDNA clearance. Full article

Alphaviruses have historically been viewed as acute, self-limiting pathogens. However, growing evidence shows that viral RNA and antigens can persist in vertebrate hosts long after the resolution of acute infection, a phenomenon known as viral persistence. Viral persistence reflects a dynamic interplay between viral replication—including shifts from lytic to non-lytic infection—and host defenses, which together establish cellular and tissue niches that enable evasion of immune-mediated clearance. Within vertebrate hosts, alphaviruses exhibit broad tissue tropism, infecting diverse cell types that may differentially support long-term persistence. Emerging evidence suggests that viral persistence arises through three interconnected processes: (i) selective infection of specific cellular niches, (ii) reprogramming of host cellular pathways, and (iii) modulation of immune responses. Yet, the extent to which viral or host determinants shape this balance, and how persistence contributes to chronic disease, remains unresolved. Here, we synthesize current in vitro and in vivo evidence of alphavirus persistence in vertebrate hosts and discuss potential mechanisms by which alphaviruses establish and maintain persistent infection beyond the acute phase. We further underscore critical gaps in current knowledge and outline future research avenues essential for elucidating the mechanisms underlying alphavirus pathogenesis. Full article

Despite substantial progress in medical care, acute myocarditis remains a life-threatening disorder with a sudden onset, often unexpectedly complicating a simple and common upper respiratory tract infection. In most cases, myocarditis is triggered by viral infections (over 80%), with an estimated incidence of 10–106 per 100,000 annually. The clinical course may worsen in cases of mixed etiology, where a primary viral infection is complicated by secondary bacterial pathogens, leading to prolonged inflammation and an increased risk of progression to chronic active myocarditis or dilated cardiomyopathy. We present a case report illustrating the clinical problem of acute myocarditis progression into a chronic active form. A central element of host defense is the inflammasome—an intracellular complex that activates pyroptosis and cytokine release (IL-1β, IL-18). While these processes help combat pathogens, their persistent activation may sustain inflammation and trigger heart failure and cardiac fibrosis, eventually leading to dilated cardiomyopathy. In this review, we summarize the current understanding of inflammasome pathways and their dual clinical role in myocarditis: they are essential for controlling acute infection but may become harmful when overactivated, contributing to chronic myocardial injury. Additionally, we discuss both novel and established therapeutic strategies targeting inflammatory and anti-fibrotic mechanisms, including IL-1 receptor blockers (anakinra, canakinumab), NOD-like receptor protein 3 (NLRP3) inhibitors (colchicine, MCC950, dapansutrile, INF200), NF-κB inhibitors, and angiotensin receptor-neprilysin inhibitors (ARNI), as well as microRNAs. Our aim is to emphasize the clinical importance of early identification of patients at risk of transitioning from acute to chronic inflammation, elucidate the role of inflammasomes, and present emerging therapies that may improve outcomes by balancing effective pathogen clearance with limitation of chronic cardiac damage. Full article

Dengue virus remains a major global health threat due to the lack of a safe and broadly effective vaccine. Traditional antibody-based vaccines often show limited protection and can exacerbate disease severity in individuals without prior exposure. A new generation of T-cell epitope-based vaccines offers a promising and safer approach by activating the cellular arm of the immune system to complement antibody responses. Instead of targeting only surface structural proteins, these vaccines focus on highly conserved peptide regions within non-structural proteins, particularly NS3 and NS5, that are shared across all four dengue virus serotypes. Peptides such as DTTPFGQQR, KPGTSGSPI, and MYFHRRDLRL have been identified as potent immunogenic targets capable of inducing strong cytotoxic and helper T-cell responses, promoting viral clearance and long-term immune memory. Advanced immunoinformatic enables precise prediction and selection of epitopes with high binding affinity to human leukocyte antigens and broad cross-serotype conservation. These peptides can be integrated into next-generation vaccine delivery systems, including messenger RNA and nanoparticle platforms, which enhance antigen presentation, improve molecular stability, and reduce the risk of antibody-dependent disease enhancement. Together, this integrative design represents a rational path toward a safer, cross-protective, and durable dengue vaccine that closely mimics the balanced cellular and humoral immunity observed after natural infection, offering renewed hope for effective global dengue prevention. Full article

Chronic hepatitis B (CHB) remains a major global health challenge, largely due to the persistence of covalently closed circular DNA (cccDNA) and impaired host immunity. Interferon-α (IFN-α), a key antiviral cytokine, not only directly restricts HBV replication but also orchestrates innate and adaptive immune responses. This review summarizes current advances in IFN-α-mediated immune regulation, highlighting its effects across diverse immune cell populations. Evidence indicates that IFN-α can reprogram immune responses to promote viral clearance, although clinical efficacy is limited by modest response rates and adverse effects. Recent progress in cytokine engineering, subtype research, and rational combination strategies—including nucleo(s/t)ide analogs, RNA interference therapeutics, antisense oligonucleotides, therapeutic vaccines, and beyond—has expanded opportunities to improve treatment outcomes. While challenges remain, these advances lay the foundation for optimizing IFN-α–based interventions and highlight IFN-α as a key driver for innovative therapies aimed at achieving a functional cure of chronic hepatitis B. Full article

Background: Porcine reproductive and respiratory syndrome virus (PRRSV) causes significant economic losses for the global swine industry. Gilt immunization using modified live virus (MLV) vaccines is crucial for herd stability, but it is complicated by frequent mixed infections of PRRSV strains on farm. This study monitored the administration of tylvalosin during a PRRSV-2 MLV (TJM) immunization program, focusing on viral dynamics and immune responses in gilts naturally exposed to co-circulating classical (GD240101) and highly pathogenic like (HP-PRRSV-like, GD240102) PRRSV strains. Methods: The animal study was approved by the Laboratory Animal Ethical Committee of China Agricultural University. One hundred gilts were randomized into control and tylvalosin groups (n = 50/group). All received the TJM MLV vaccination. The tylvalosin group received tylvalosin tartrate premix cyclically in-feed for three cycles. Serum and saliva samples were collected periodically. PRRSV RNA (RT-qPCR) and specific antibodies (ELISA) were assessed. Viral population dynamics (relative abundance, mutation, recombination of TJM, GD240101, and GD240102) were monitored via next-generation sequencing (NGS) on a pooled PRRSV-positive sample. Results: In this field trial where tylvalosin was used, a shorter duration of PRRSV viremia and saliva shedding was observed to compare with controls. NGS analysis showed accelerated vaccine strain (TJM) clearance in the tylvalosin group (by week 3 vs. week 9 in control). Field strain dynamics were also altered, showing a faster decline in the tylvalosin group. Antibody response uniformity was altered, with lower coefficient of variation (CV) for PRRSV and CSFV observed following tylvalosin usage. Conclusions: In gilts receiving tylvalosin for the management of bacterial pathogens during a PRRSV MLV immunization program, it was associated with accelerated viral clearance and enhanced systemic immune response uniformity under mixed-infection field conditions. NGS provides invaluable data for dissecting these complex viral dynamics. Crucially, these findings describe a biological drug–host–virus interaction and should not be interpreted as an endorsement for the prophylactic use of antimicrobials. In alignment with global antimicrobial stewardship principles, tylvalosin should be reserved for the therapeutic treatment of diagnosed bacterial diseases to mitigate the risk of promoting resistance. Full article

Background: Herpes simplex virus (HSV) is a neurotropic virus that can be categorized into two serotypes: HSV-1 and HSV-2. HSV-1 causes symptoms such as herpes labialis, herpetic keratitis, genital ulcers, and encephalitis, and primarily establishes latent infection in the trigeminal ganglion. The complexity of membrane fusion mechanisms and potential infection in nerves allow HSV to easily evade recognition and clearance by host immune cells. Therefore, developing a vaccine that can prevent both primary and reactivated HSV-1 infection is critical. Currently, no preventive or therapeutic HSV-1 vaccines have been approved for marketing. Methods: In this study, we utilized the gC, gD, and gE proteins of HSV-1, which are associated with viral fusion and immune escape, to design a trivalent antigen vaccine that is capable of inducing a cellular immune response. Two formulations of the vaccine are available: a subunit vaccine incorporating oligodeoxynucleotides with CpG motifs (CpG ODNs) and QS-21 as adjuvants, as well as an mRNA vaccine. Mice were immunized via intramuscular injection to evaluate and compare the immunological responses and protective efficacy of the two vaccines. Results: After the challenge, the viral load in the tissues of both vaccine groups was significantly lower than that in the positive control group, indicating that both vaccines were able to control viral proliferation in the tissues. Conclusions: The findings indicated that both mRNA and subunit vaccines were capable of eliciting comparable humoral and cellular immune responses. Full article

Ankylosing spondylitis (AS) displays wide inter-patient variability that is not accounted for by HLA-B27 alone, suggesting that additional immune and metabolic modifiers contribute to disease severity. Using a genetically matched design, we profiled peripheral blood mononuclear cells from two brother pairs discordant for AS severity and one healthy brother pair. Strand-specific RNA-seq was analyzed with a family-blocked DESeq2 model, while untargeted metabolites were quantified using gas chromatography–mass spectrometry (GC-MS) and liquid chromatography–mass spectrometry (LC-MS). Differential features were defined as follows: differentially expressed genes (DEGs) (|log₂FC| ≥ 1 and FDR < 0.05) and metabolites (VIP > 1, FC ≥ 1.2, and BH-adjusted p < 0.05). Pathway enrichment was performed with KEGG and Gene Ontology (GO). A total of 325 genes were differentially expressed. Type I interferon and neutrophil granule transcripts (e.g., IFI44L, ISG15, S100A8/A9) were markedly up-regulated, whereas mitochondrial β-oxidation genes (ACADM, CPT1A, ACOT12) were repressed. Metabolomics revealed 110 discriminant features, including 25 MS/MS-annotated metabolites. Primary bile acid intermediates were depleted, whereas oxidized fatty acid derivatives such as 12-Z-octadecadienal and palmitic amide accumulated. Spearman correlation identified two antagonistic modules (i) interferon/neutrophil genes linked to pro-oxidative lipids and (ii) lipid catabolism genes linked to bile acid species that persisted when severe and mild siblings were compared directly. Enrichment mapping associated these modules with viral defense, neutrophil degranulation, fatty acid β-oxidation, and bile acid biosynthesis pathways. This sibling-paired peripheral blood mononuclear cell (PBMC) dual-omics study delineates an interferon-driven lipid–bile acid axis that tracks AS severity, supporting composite PBMC-based biomarkers for future prospective validation and highlighting mitochondrial lipid clearance and bile acid homeostasis as potential therapeutic targets. Full article

The gut microbiome plays a key role in immune regulation. Young children experience rapid microbiome development, yet data on its alteration during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection remain limited. This study aimed to characterize gut microbiome changes and immune-related pathway alterations in young children with coronavirus disease 2019 (COVID-19). Eighteen children under 2 years old with confirmed SARS-CoV-2 infection and seven healthy controls were enrolled between December 2021 and June 2022. Stool samples were analyzed using 16S rRNA gene sequencing. In children with COVID-19, the gut microbiome exhibited an increase in Bacteroidota and Bacillota, whereas Actinomycetota and Pseudomonadota were reduced, with higher abundances of Bifidobacterium, Escherichia, and Streptococcus and lower abundances of Faecalibacterium, Clostridium, and Ruminococcus compared with healthy controls. Children with COVID-19 exhibited reduced alpha diversity, indicating microbial dysbiosis, and significant differences in beta diversity compared with healthy controls. Predictive functional analysis revealed downregulation of key immune-related pathways, such as interleukin-17, NOD-like receptor, and Toll-like signaling, which may impact mucosal immunity and viral clearance in children with COVID-19. SARS-CoV-2 infection in early childhood is associated with gut dysbiosis and the suppression of key immune pathways. These findings highlight the potential long-term impact of early-life microbial disruptions on immune development. Full article

Multidrug resistance (MDR) remains a formidable barrier to successful cancer treatment, driven by mechanisms such as efflux pump overexpression, enhanced DNA repair, evasion of apoptosis and the protective characteristics of the tumour microenvironment. Nanoparticle-based delivery systems have emerged as promising platforms capable of addressing these challenges by enhancing intracellular drug accumulation, enabling targeted delivery and facilitating stimuli-responsive and controlled release. This review provides a comprehensive overview of the molecular and cellular mechanisms underlying MDR and critically examines recent advances in nanoparticle strategies developed to overcome it. Various nanoparticle designs are analysed in terms of their structural and functional features, including surface modifications, active targeting ligands and responsiveness to tumour-specific cues. Particular emphasis is placed on the co-delivery of chemotherapeutic agents with gene regulators, such as siRNA, and the use of nanoparticles to deliver CRISPR/Cas9 gene editing tools as a means of re-sensitising resistant cancer cells. While significant progress has been made in preclinical settings, challenges such as tumour heterogeneity, limited clinical translation and immune clearance remain. Future directions include the integration of precision nanomedicine, scalable manufacturing and non-viral genome editing platforms. Collectively, nanoparticle-based drug delivery systems offer a multifaceted approach to combat MDR and hold great promise for improving therapeutic outcomes in resistant cancers. Full article

Viruses use a range of sophisticated strategies to evade detection by cytotoxic T-lymphocytes (CTLs) within host cells. Beyond elaborating dedicated viral proteins that disrupt the MHC class I antigen-presentation machinery, some viruses possess intrinsic, cis-acting genome-encoded elements that interfere with antigen processing and display. These protein features, including G-quadruplex motifs, repetitive peptide sequences, and rare-codon usage, counterintuitively limit production of proteins critical to virus survival, particularly during latency. By slowing viral protein synthesis, these features reduce antigen production and proteosomal degradation, ultimately limiting the generation of peptides for MHC I presentation. These built-in evasion tactics enable viruses to remain “invisible” to CTLs during latency. While these primary sequence intrinsic immune evasion (PSI) mechanisms are well-described in select herpesviruses, emerging evidence suggests that they may also play a critical role in RNA viruses. How these proteins are made, rather than what they functionally target, determines their immune evasion properties. Understanding PSI mechanisms could rationally inform the design of engineered viral antigens with altered or removed evasion elements to restore antigen CTL priming and activation. Such vaccine strategies have the potential to enhance immune recognition, improve clearance of chronically infected cells, and contribute to the treatment of persistent viral infections and virus-associated cancers. Full article

Neuropathic pain is a significant global clinical issue that poses substantial challenges to both public health and the economy due to its complex underlying mechanisms. It has emerged as a serious health concern worldwide. Recent studies involving dorsal root ganglion (DRG) stimulation have provided strong evidence supporting its effectiveness in alleviating chronic pain and its potential for sustaining long-term pain relief. In addition to that, there has been ongoing research with clinical evidence relating to the role of small non-coding ribonucleic acids known as microRNAs in regulating gene expressions affecting pain signals. The signal pathway involves alterations in neuronal excitation, synaptic transmission, dysregulated signaling, and subsequent pro-inflammatory response activation and pain development. When microRNAs are dysregulated in the dorsal root ganglia neurons, they polarize macrophages from anti-inflammatory M2 to inflammatory M1 macrophages causing pain signal generation. By reversing this polarization, a therapeutic activity can be induced. However, the direct delivery of these nucleotides has been challenging due to limitations such as rapid clearance, degradation, and reduction in half-life. Therefore, safe and efficient carrier vehicles are fundamental for microRNA delivery. Here, we present a comprehensive analysis of miRNA-based nano-systems for chronic neuropathic pain, focusing on their impact in dorsal root ganglia. This review provides a critical evaluation of various delivery platforms, including viral, polymeric, lipid-based, and inorganic nanocarriers, emphasizing their therapeutic potential as well as their limitations in the treatment of chronic neuropathic pain. Innovative strategies such as hybrid nanocarriers and stimulus-responsive systems are also proposed to enhance the prospects for clinical translation. Serving as a roadmap for future research, this review aims to guide the development and optimization of miRNA-based therapies for effective and sustained neuropathic pain management. Full article

Epstein–Barr virus (EBV), a double-stranded DNA virus, is implicated in nasopharyngeal carcinoma (NPC), with particularly high incidence in regions such as southern China and Hong Kong. Although NPC is typically treated with radio- and chemotherapy, outcomes remain poor for advanced-stage diagnoses, highlighting the need for targeted therapies. This study explores the potential of CRISPR/CRISPR-associated protein 13 (Cas13) technology to target essential EBV RNA in NPC cells. Previous research demonstrated that CRISPR/Cas9 could partially reduce EBV load, but suppression was incomplete. Here, the combination of CRISPR/Cas13 with CRISPR/Cas9 shows enhanced viral clearance. Long-term EBNA1 suppression via CRISPR/Cas13 reduced the EBV genome, improved CRISPR/Cas9 effectiveness, and identified suitable AAV serotypes for delivery. Furthermore, cotreatment increased NPC cell sensitivity to 5-fluorouracil and cisplatin. These findings underscore the potential of CRISPR/Cas13 as an anti-EBV therapeutic approach, effectively targeting latent EBV transcripts and complementing existing treatments. The study suggests a promising new direction for developing anti-EBV strategies, potentially benefiting therapies for NPC and other EBV-associated malignancies. Full article