Search Results (2,558)

(1) Background: After HBV infection, viral transcripts and host RNA form a multi-layered interwoven regulatory network. However, a comprehensive map encompassing mRNA, miRNA, lncRNA, and circRNA is still lacking. This absence complicates the systematic explanation of the molecular mechanisms driving immune escape and metabolic reprogramming during the persistent infection stage. (2) Methods: In this study, we established a mouse model of chronic HBV infection and analyzed the differential expression of mRNA, miRNA, lncRNA, and circRNA through whole transcriptome sequencing (WTS). We constructed a competing endogenous RNA (ceRNA) network to systematically evaluate the overall impact of HBV on the host’s immune-metabolic pathways. (3) Results: RNA sequencing results indicated that HBV infection significantly up-regulated 194 mRNAs, 18 miRNAs, 184 lncRNAs, and 28 circRNAs, while down-regulating 42, 16, 122, and 31 corresponding transcripts, respectively. The differentially expressed genes were primarily enriched in pathways related to metabolism, immunity/inflammation, and signal transduction-ligand receptor interactions. Furthermore, the competitive endogenous RNA networks of lncRNA-miRNA-mRNA and circRNA-miRNA-mRNA constructed on this basis further identified miR-185-3p as a key core node. (4) Conclusions: In this study, based on whole transcriptome data, the gene expression profiles of rcccDNA/Ad-infected Alb-Cre transgenic mice (chronic HBV infection model) and normal Alb-Cre mice were systematically compared, and the core regulatory factor miR-185-3p of key differentially expressed genes was screened. The microRNA is expected to provide a new target for the precise treatment of chronic hepatitis B by targeted intervention of viral replication and high liver inflammation. Full article

The application of cryo-electron microscopy (cryo-EM) in membrane protein structural biology has catalyzed unprecedented advances in our understanding of fundamental biological processes and transformed drug discovery paradigms. This review briefly describes the biological achievements enabled using cryo-EM techniques, including single particle analysis (SPA), micro-electron diffraction (microED), and subtomogram averaging (STA), in elucidating the structures and functions of membrane proteins, ion channels, transporters, and viral glycoproteins. We highlight how these structural insights have revealed druggable sites, enabled structure-based drug design, and provided mechanistic understanding of disease processes. Key biological targets include G protein-coupled receptors (GPCRs), ion channels implicated in neurological disorders, respiratory chain complexes, viral entry machinery, and membrane transporters. The integration of cryo-EM with computational drug design has already yielded clinical candidates and approved therapeutics, marking a new era in membrane protein pharmacology. Full article

The emergence of SARS-CoV-2 and its rapid global spread underscores the urgent need for novel therapeutic strategies. This study investigates the antiviral potential of Allium sativum (garlic) extracts against SARS-CoV-2, focusing on disruption of the spike protein’s receptor-binding domain (RBD) interaction with angiotensin-converting enzyme 2 (ACE2), a critical step in viral entry. Two garlic cultivars (Tigre and Fermín) were processed via oven-drying or freeze-drying, followed by maceration with CH₂Cl₂/MeOH (1:1) and fractionation with liquid–liquid partition. ELISA immunoassays revealed that freeze-dried Tigre (TL) extracts had the highest inhibitory activity (42.16% at 0.1 µg/mL), with its aqueous fraction achieving 57.26% inhibition at 0.01 µg/mL. Chemical profiling via GC-MS found sulfur and other types of compounds. Molecular docking identified three garlic TL-derived aqueous fraction compounds with strong binding affinities (ΔG = −7.5 to −6.9 kcal/mol) to the RBD-ACE2 interface. Furthermore, ADME in silico analysis highlighted one of them (L17) as the main candidate, having high gastrointestinal absorption, blood–brain barrier permeability, and compliance with drug-likeness criteria. These findings underscore garlic-derived compounds as promising inhibitors of SARS-CoV-2 entry, calling for further preclinical validation. The study integrates experimental and computational approaches to advance natural product-based antiviral discovery, emphasizing the need for standardized formulations to address therapeutic variability across viral variants. Full article

Dendritic cells (DCs) are among the first immune cells to detect viral invasion and play a central role in initiating and shaping antiviral immune responses. Many innate and adaptive immune functions of DCs are regulated by cathepsins, proteolytic enzymes primarily found in acidic endolysosomal compartments. Different DC subsets exhibit distinct cathepsin expression patterns, influencing their functional capacities and interactions with viruses. In DCs, cathepsins contribute to virus sensing through innate receptors, regulate cytokine production and DC migration, and are essential for viral antigen degradation and loading onto MHC molecules for T-cell activation. Many viruses, however, have evolved mechanisms to alter cathepsin expression and activity, thereby subverting DC function and promoting their own persistence. Indeed, cathepsins can facilitate viral entry into DCs, promote viral replication, and support immune evasion strategies. In this review, we summarize recent advances in understanding the role of cathepsins in DC–virus interactions, emphasizing both how DCs exploit cathepsins to generate protective immune responses and how viruses manipulate cathepsin activity to their advantage. We particularly focus on clinically relevant viral pathogens, including HIV, influenza virus, hepatitis C virus, human cytomegalovirus, Ebola virus, and SARS-CoV-2, to illustrate the multifaceted influence of cathepsins on DC biology during viral infection. Full article

ZIKA virus (ZIKV) infections in human neonates and adults are associated with deleterious effects on brain cognition and neurological disorders. The mechanism(s) of ZIKV infection in neurons and associated neuronal antiviral responses are not fully understood. In this study, we determined the effects of ZIKV infectivity in human neuronal (SH-SY5Y) cells and mouse N2a cells/primary cultures of murine cortical neurons at early and late tested timepoints of infection. The human neuronal cells had higher ZIKV loads compared to the mouse N2a cells, but the viral loads in the murine cortical neurons were between the loads in these two in vitro cell lines. The murine cortical neurons were thought to be more permissive to ZIKV infection, but viral infection kinetics showed a declining trend like that observed in the mouse N2a cells. We noted that infectious extracellular vesicle (EV)-mediated ZIKV infection showed higher viral loads in the SH-SY5Y cells compared to direct infection with laboratory virus stocks. Similar results were obtained with ZIKV infectious EVs in the mouse N2a cells and cortical neurons. In addition, we noted that ZIKV infection significantly induced EV secretion from all three neuronal cells. Also, we found that ZIKV infection modulates the expression of type 1 interferons (IFNs) and entry receptors such as Tyro3, Axl, and MER-TK (TAM). Alongside the increased ZIKV loads in the SH-SY5Y cells, IFN-beta transcript levels and receptors Tyro3/MER-TK were upregulated at early timepoints of infection. Overall, the reduced ZIKV loads and decreasing IFN expression in the mouse neuronal cells suggested a unique murine cellular ability to restrict and limit viral replication. This could be one of the reasons for the unavailability of wild-type mouse models for ZIKV infection. Our data further shows that ZIKV may preferentially infect human rather than murine neuronal cells, and this could be the potential reason for microcephaly in newborns. Full article

The coronavirus disease 2019 (COVID-19) pandemic has revealed a close and multifaceted relationship between viral infection, systemic inflammation, and cardiovascular health. Among the cardiac complications of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), atrial fibrillation (AF)—especially new-onset atrial fibrillation (NOAF)—has emerged as a major determinant of disease severity and prognosis. Clinical studies and meta-analyses show that 5–10% of hospitalized COVID-19 patients develop AF, with markedly higher rates in critically ill individuals. Both pre-existing and NOAF are independently associated with increased risks of intensive care admission, mechanical ventilation, thromboembolic events, and mortality. The underlying mechanisms involve a combination of cytokine-mediated inflammation, endothelial dysfunction, microvascular injury, and dysregulation of the renin–angiotensin–aldosterone system (RAAS). Viral downregulation of angiotensin-converting enzyme 2 (ACE2) receptors contributes to myocardial fibrosis, while hypoxia, oxidative stress, and autonomic imbalance further promote electrical remodeling and arrhythmogenesis. Post-infectious studies indicate that atrial structural changes and autonomic dysfunction may persist for months, predisposing survivors to recurrent arrhythmias. Technological advances in telecardiology and digital medicine have provided new tools for early detection and long-term monitoring. Wearable electroencephalography (ECG) devices, implantable loop recorders (ILRs), and artificial intelligence (AI)-based diagnostic algorithms enable continuous rhythm surveillance and individualized management, improving outcomes in post-COVID patients. This review summarizes current evidence on the epidemiology, pathophysiology, clinical implications, and monitoring strategies of AF in COVID-19. It underscores the importance of integrating telemedicine and AI-assisted diagnostics into cardiovascular care to mitigate the long-term arrhythmic and systemic consequences of SARS-CoV-2 infection. Full article

HIV-induced apoptosis is a contradictory complicated phenomenon that occurs at the intersection of viral persistence and host defense. HIV primarily affects CD4 T cells during an infection, causing widespread immune cell death through both direct infection and indirect (bystander) mechanisms. This immunopathologic process is caused by viral proteins such as Tat, Nef, Env, and Vpr, which modify host signaling cascades such as the PI3K/Akt, p53, NF-κB, and mitochondrial pathways. Dysregulation of pro- and anti-apoptotic mediators, particularly Bax, Bcl-2, and caspase activation, which results in mitochondrial depolarization, oxidative stress, and cytochrome c release, exacerbates immune depletion. Although apoptosis serves as a host antiviral mechanism to limit viral replication and spread, HIV exploits it to evade immune surveillance and establish chronic infection. HIV pathogenesis, which includes lymphoid tissue destruction, microbial translocation, and persistent inflammation, is significantly influenced by apoptosis of both infected and bystander cells. Furthermore, alterations in death receptor signaling (Fas/FasL and TNF pathways) and mitochondrial dysfunction highlight the delicate balance between immune defense and viral manipulation. Despite considerable progress in antiretroviral therapy, immune restoration is still incomplete due to ongoing apoptotic loss and immune exhaustion. This review examines the biological mechanisms underlying HIV-induced apoptosis, evaluates the dual role of cell death in host defense versus viral persistence, and highlights novel therapeutic targets intended to restore immune homeostasis and reduce HIV-associated immunopathology. Full article

Chimeric antigen receptor (CAR) therapy represents a promising modality for treating cancer and autoimmune diseases, employing genetically engineered immune cells. Despite remarkable clinical outcomes, its broad implementation is constrained by significant challenges, including toxicity, limited specificity, and complexities associated with genetic material delivery. Biological nanoparticles, such as exosomes, virus-like particles, and biomimetic nanostructures, possess unique properties that can address these limitations. These nanoplatforms enable targeted delivery of genetic constructs, mitigate the risk of cytokine release syndrome, modulate CAR cell activity, and can function as biosensors. Furthermore, they facilitate non-viral, in vivo CAR cell engineering, streamlining the process compared to conventional ex vivo methods. The advancement of in vivo strategies underscores the critical need to overcome toxicity hurdles inherent to current CAR-T platforms. In this context, exosomes and biomimetic nanoparticles offer considerable potential due to their innate biocompatibility, programmability, and versatile cargo capacity for payloads like mRNA and circular RNA. This review comprehensively outlines contemporary genetic platforms for CAR expression and examines the opportunities presented by biological delivery vehicles. It focuses on recent achievements and revisits fundamental CAR principles through the lens of emerging technologies aimed at confronting persistent challenges in the field. Full article

Background/Objectives: Pregnant people with HIV (PWH) are more likely to experience systemic inflammation than pregnant people without HIV (PWoH), which may contribute to adverse outcomes in HIV-exposed uninfected (HEU) infants; however, the underlying mechanisms are not well studied. This study examined associations between maternal inflammatory markers during pregnancy and cord blood inflammatory markers and metabolomic signatures. Methods: Between 2011 and 2025, pregnant PWH and PWoH were enrolled at 24–28 weeks of gestational age. Maternal plasma was analyzed for inflammatory markers [interleukin (IL)-6, high-sensitivity C-reactive protein (hsCRP), soluble TNF-α receptor 1 (sTNFR1) and 2 (sTNFR2), soluble CD163 (sCD163), soluble CD14 (sCD14)]. At delivery, cord blood was collected for measurement of IL-6, TNF-α, IFN-γ, and IL-10 and for targeted metabolomics by ultra-performance liquid chromatography–mass spectrometry. Spearman correlation, linear regression, and weighted correlation network analysis (WGCNA) were used to evaluate associations, stratified by HIV exposure. Results: This study included 22 PWH and 47 PWoH and their infants. Among HEU infants, but not HUU infants, maternal IL-6 correlated with cord blood TNFα (r = 0.443, p < 0.05) and maternal sTNFR1 correlated with both cord blood TNFα (r = 0.617, p < 0.05) and IFNγ (r = −0.517, p < 0.05). WGCNA identified five metabolomic modules. In the HEU group, naternal sCD14 was positively associated with a metabolomic module characterized by lysophosphotidylecholines in the HEU group. Conclusions: We identified distinct patterns in the relationships between maternal inflammation and infant immune–metabolic profiles by HIV exposure status. These findings suggest that HIV infection, even with viral suppression, may alter the maternal–fetal inflammatory interface and influence early metabolic programming. Full article

Enterovirus A71 (EV-A71) is a critical global pathogen, primarily causing Hand-Foot-and-Mouth Disease (HFMD) but frequently leading to severe neurological complications, including fatal neurogenic pulmonary edema (PE). This review elucidates the complex interplay between viral pathogenesis and the host immune response. EV-A71 utilizes receptors like SCARB2 and PSGL-1 for entry, while its proteases (2A^pro, 3C^pro) efficiently evade innate immunity by cleaving key signaling adaptors (MAVS, TRIF), suppressing Type I IFN response. Critical to disease progression is the age-dependent vulnerability in infants and the subsequent shift toward immunopathology. Severe disease is driven by a systemic cytokine storm and T cell dysregulation, characterized by a loss of control from Treg cells and a profound Th17/Treg imbalance, resulting in high levels of pathogenic cytokines (e.g., IL-17A, IFN-γ). Clinical progression is predicted by specific biomarkers, including Treg depletion, monocyte exhaustion (PD-1/PD-L1), and suppressed regulatory signaling (low cAMP). These findings highlight that effective therapeutic strategies must target host-mediated damage through immunomodulation (e.g., by exploring interventions against key pathogenic axes like IL-6 and IL-1β) and call for the development of next-generation vaccines capable of eliciting balanced cellular immunity to prevent immunopathology. Full article

Background: Antigen format strongly influences the immunogenicity of gene-based vaccines. Full-length Spike is widely used in licensed COVID-19 vaccines, while truncated subunits such as S1 or the receptor-binding domain (RBD) may simplify vector design but risk reduced potency. We aimed to compare these antigen formats in an AAV9 delivery platform. Methods: BALB/c mice were immunized intramuscularly with recombinant AAV9 encoding full-length Spike, S1, or RBD at doses of 1 × 10¹⁰ or 1 × 10¹¹ viral genomes. Immune responses were assessed by serology, virus neutralization, T-cell profiling, and histopathology. Results: All constructs expressed antigen in vitro and in vivo. Only full-length Spike elicited robust neutralizing antibodies at both doses, with titers rising significantly by week 12. High-dose RBD induced neutralization in a minority of animals, whereas S1 failed to do so. Antigen-specific IgG responses scaled with insert length (Spike > S1 > RBD). Cellular immunity was dominated by CD8⁺ effector memory T cells, strongest in the Spike group, which also induced measurable CD4⁺ responses. Local transient myositis was observed at the injection site but resolved by week 24, with no systemic pathology. Conclusions: Full-length Spike outperforms truncated subunits in the AAV context, highlighting antigen structure as a critical factor for next-generation coronavirus vaccine design. Full article

The H3N8 low pathogenic avian influenza virus (LPAIV) exhibits broad host tropism, infecting diverse avian and mammalian species, raising concerns about its zoonotic potential. Following the emergence of human infections with H3N8 LPAIV in China, including a fatal case, we investigated the epidemiological and virological characteristics of this virus in Guangdong Province. In 2022, a serological survey revealed H3N8 seroprevalence rates of 10.85% in farmed chickens and 7.97% in ducks. We isolated three H3N8 viruses, designated as A/chicken/Qingyuan/22/2022 (H3N8); A/chicken/Qingyuan/31/2022 (H3N8); and A/chicken/Qingyuan/15/2022 (H3N8), and found that these chicken isolates, like the human isolate A/Changsha/1000/2022, share the same E190 residue. This residue can synergize with sites such as Q226 and G228 to enhance binding affinity for SAα-2,6-Gal. Additionally, they harbor the three amino acid residues N193, W222, and S227. Among these, N193 has the potential to form hydrogen bonds with α2-6-linked glycans, while W222 and S227 may alter the conformational flexibility of the 220-loop. These two effects collectively endow the H3N8 isolates with dual receptor-binding properties. These findings suggest a shift in receptor specificity, potentially facilitating viral adaptation to mammalian hosts. Characterization of viral genome detection dynamics, and histopathology in animal models further elucidated the viral infection dynamics. Our study provides critical insights into the evolutionary trajectory and zoonotic potential of the H3N8 LPAIV. Full article

The human immunodeficiency virus (HIV) remains a major global health challenge. A promising therapeutic strategy involves identifying human proteins capable of physically blocking viral entry by interacting with key components of the HIV attachment system. To address this challenge systematically, we developed a computational pipeline for prioritizing protein–protein interaction and applied it to identify host proteins interacting with the viral glycoprotein gp120 and cellular receptors (CD4, CCR5, CXCR4, CCR2). Our approach combined large-scale interaction modeling using AlphaFold 3 with a comprehensive comparative analysis framework. We screened a panel of 55 candidate human proteins selected through integrated bioinformatics analysis. The pipeline incorporated model confidence assessment, quantitative contact analysis, and normalization against reference interactions to generate a robust ranking of candidates. Key findings reveal several important patterns. Chemokine CCL27 uniquely demonstrated high binding potential to both CCR5 co-receptor and viral gp120, suggesting its potential for dual-blockade capability. Analysis of natural ligand interactions with chemokine receptors showed marked disparity: CC-chemokine family members exhibited significantly greater binding capacity for CCR5 and CCR2 receptors compared to CXC-family ligand interactions with CXCR4. This binding imbalance may potentially drive selective viral pressure and influence tropism evolution during disease progression. We also identified potential interactions between HIV entry components and neuropeptides including PNOC and NPY, as well as various membrane receptors beyond classical coreceptors. Furthermore, cluster analysis revealed clear separation between receptor-type and ligand-type interactors, supporting the biological plausibility of our predictions. While acknowledging limitations related to model refinement, this study provides a systematically ranked set of candidate targets for HIV therapeutic development. Beyond identifying specific HIV interaction candidates, this study establishes a generalizable computational pipeline for the prioritization of protein–protein interaction in pathogen-host systems, effectively bridging large-scale modeling. Full article

Aberrant activation of innate immunity promotes the development of pulmonary arterial hypertension (PAH); however, the role of pattern recognition by Toll-like receptors (TLRs) within the pulmonary vasculature remains unclear. To consolidate knowledge (as of June 2025) about TLRs and their interactions with viruses in PAH and to identify therapeutic implications. A narrative review of experimental and clinical studies investigating ten TLRs in the context of the pulmonary vascular microenvironment and viral infections. Activation of TLR1/2, TLR4, TLR5/6, TLR7/8, and TLR9 converges on the MyD88–NF-κB/IL-6 axis, thereby enhancing endothelial-mesenchymal transition, smooth muscle proliferation, oxidative stress, thrombosis, and maladaptive inflammation, ultimately increasing pulmonary vascular resistance. Conversely, TLR3, through TRIF–IFN-I, preserves endothelial integrity and inhibits vascular remodeling; its downregulation correlates with PAH severity, and poly (I:C) restitution has been shown to improve hemodynamics and right ventricular function. HIV-1, EBV, HCV, endogenous retrovirus K, and SARS-CoV-2 infections modulate TLR circuits, either amplifying pro-remodeling cascades or attenuating protective pathways. The “TLR rheostat” is shaped by polymorphisms, ligand biochemistry, compartmentalization, and biomechanical forces. The balance between MyD88-dependent signaling and the TRIF–IFN-I axis determines the trajectory of PAH. Prospective therapeutic strategies may include TLR3 agonists, MyD88/NF-κB inhibitors, modulation of IL-6, and combination approaches integrating antiviral therapy with targeted immunomodulation in a precision approach. Full article

Recent studies suggest that immune response to pathogens may vary depending on changes in hormone levels. Toll-like receptors (TLRs) are the key components of the innate immune system and play a crucial role in HIV infection. Given the significant genetic diversity of HIV-1, this study examined the effect of female sex hormones on the several TLR2, TLR4, and TLR9 expression in human peripheral blood mononuclear cells (PBLs) isolated from different female donors and infected with different variants of HIV-1 subtypes A6 and B. Thus, high doses of hormones upregulated the TLR2 and TLR9 expression in PBLs infected only with v1.A6, which also correlated with an increased viral load: by 3.8 times (p = 0.0033) when cells were treated with estradiol and by 4.4 times (p = 0.006) when treated with progesterone. Hormones did not modulate TLRs expression in the cells infected with subtype B, with the exception of one donor. In PBLs from this donor infected with the v1.B variant, hormones upregulated TLRs expression, which also correlated with the increased viral load (1.3-fold increase (p = 0.0036)). Hence, it was shown that gonadal steroids can play an important role in HIV-1 replication and immune response to a pathogen. Moreover, it was shown that different isolates of the same subtype may have distinct biological properties. The detected diversity in the TLRs expression in infected PBLs from different donors indicates that host genetics may also play an important role in HIV susceptibility. Full article