Search Results (1,888)

Toll-like receptors (TLRs) are essential pattern recognition receptors of the innate immune system and play critical roles in pathogen invasion in teleosts. In this study, we identified and characterized full-length open reading frames of three TLRs belonging to the TLR11 subfamily from Schizothorax prenanti, termed spTLR19 (2868 bp), spTLR20 (2835 bp), and spTLR21 (2946 bp), encoding 955, 944, and 981 amino acids, respectively. All three proteins exhibited the conserved domain architecture typical of TLRs, comprising a leucine-rich repeat (LRR) domain, a transmembrane region, and a Toll/IL-1 receptor (TIR) domain. Phylogenetic and homology analyses revealed that spTLR19 and spTLR20 clustered most closely with their homologues from Cyprinus carpio, while spTLR21 showed the highest similarity to Onychostoma macrolepis TLR21. Expression profiling showed that these TLRs were ubiquitously expressed across examined tissues, with relatively higher expression in immune-related tissues such as spleen and gills. Furthermore, challenge with Streptococcus agalactiae and Aeromonas veronii significantly up-regulated the expression of spTLR19, spTLR20, and spTLR21 in spleen, liver, and gills, suggesting their involvement in antibacterial immune responses. These findings enhance the functional understanding of the teleost TLR11 subfamily and provide a foundation for elucidating disease resistance and immune regulation in S. prenanti. Full article

Metabolic inflammation, a state of chronic low-grade inflammation linked to insulin resistance, plays a central role in the development of obesity-related conditions such as type 2 diabetes, non-alcoholic fatty liver disease (NAFLD), and cardiovascular disorders. In recent years, two molecules have gained significant prominence in this field, owing to their mechanistic involvement in metabolic inflammation and insulin resistance: fetuin-A (FetA), aliver-derived hepatokine, and chymase, a serine protease released from mast cells. Although they arise from distinct biological sources, they converge on overlapping inflammatory and metabolic pathways. FetA acts as an endogenous ligand for Toll-like receptor 4 (TLR4), activating nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling, driving proinflammatory cytokine release, and impairing insulin signaling. Chymase, on the other hand, generates angiotensin II and activates transforming growth factor-β (TGF-β), thereby promoting oxidative stress, fibrosis, and secondary metabolic dysfunction. This review proposes a conceptual dual-target framework in which FetA and chymase are considered complementary, rather than independent, mediators of metabolic inflammation. Importantly, this framework is not intended to supersede other established pathways implicated in metabolic inflammation, but rather to provide an integrative perspective that complements existing hepatokine and immune-centered models. Their convergence on NF-κB and TGF-β signaling pathways highlights shared mechanistic nodes within metabolic inflammation. Accordingly, the emphasis of this review is on mechanistic integration within metabolic inflammation, rather than on immediate therapeutic innovation or clinical translation. Full article

Background: Liver fibrosis drives mortality in chronic liver disease, with effective and approved targeted therapies being an urgent unmet medical need. Natural polysaccharides are promising multitarget candidates, but a critical appraisal of the preclinical evidence for their translatability is lacking. Objective: This review systematically synthesizes the evidence on the efficacy, mechanisms, and methodological quality of preclinical studies investigating the antifibrotic potential of natural polysaccharides. Methods: Six databases were searched (inception to February 2025) for studies in experimental liver fibrosis models. The review followed PRISMA guidelines. Risk of bias and reporting quality were assessed using the SYRCLE (Systematic Review Centre for Laboratory Animal Experimentation) and ARRIVE (Animal Research: Reporting of In Vivo Experiments) guidelines, respectively. Results: Eighty-eight studies on 44 polysaccharides were included. A major limitation was the predominant use of the carbon tetrachloride (CCl₄) rat model (54.5%). Despite this, polysaccharides showed consistent efficacy: collagen deposition was suppressed in 92.0% of studies, and serum alanine/aspartate aminotransferase (ALT/AST) were reduced in 100%. Mechanistically, inhibition of the transforming growth factor-beta (TGF-β)/Smad pathway (implicated in 60.2% of studies) and modulation of the toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB) pathway (15.9%) were the most common findings. However, methodological quality was low, with unclear allocation concealment (92.0%) and absent blinding (86.4%) being pervasive issues. Conclusions: This review confirms that natural polysaccharides consistently attenuate experimental fibrosis by modulating key pathways like TGF-β/Smad. Our key contribution is highlighting a critical disconnect: demonstrated efficacy is undermined by poor methodological rigor and the use of simplistic models. This gap represents a major barrier to clinical translation. Advancing these promising agents requires prioritizing chemical standardization, employing more relevant disease models, and adhering to rigorous reporting standards. Full article

Trained immunity (TRIM) enhances innate immune responses through epigenetic and metabolic reprogramming but may become maladaptive, contributing to chronic inflammation. In people living with HIV (PLWH), maladaptive TRIM has been proposed but remains insufficiently characterized. We examined inflammatory cytokine production in monocyte-derived macrophages (MDMs) obtained from PLWH and age-matched individuals without HIV infection. Baseline cytokine output and responses to stimulation of Toll-like receptors (TLR) were measured. We further examined whether TRIM influenced susceptibility to HIV infection in MDMs derived from monocytes exposed to extracellular vesicles carrying the HIV-1 Nef protein (Nef EVs). Baseline IL-6 production did not differ between unstimulated MDMs from PLWH and uninfected controls. Although sex-associated differences were initially observed, these effects were no longer significant after adjustment for infection duration. IL-6 responses following TLR2 and TLR7 stimulation, but not TLR4 stimulation, were significantly amplified in PLWH-derived MDMs, consistent with a trained phenotype. Similar trends were observed in sex-stratified analyses but did not reach statistical significance. The magnitude of unstimulated IL-6 production positively correlated with duration of HIV infection, suggesting cumulative TRIM imprinting over time. Despite heightened inflammatory responsiveness, TRIM did not reduce susceptibility to HIV infection in Nef EV-exposed MDMs, indicating functional maladaptation rather than protective priming. These findings provide evidence of maladaptive TRIM in PLWH, characterized by preserved basal cytokine output but exaggerated inflammatory responses to innate immune stimulation without antiviral benefit. The association with infection duration supports progressive innate immune reprogramming as a contributor to HIV-associated inflammation. No statistically significant differences in trained immune responses were observed between male and female PLWH after accounting for duration of infection. Further studies are needed to define the mechanisms underlying this maladaptation and its clinical consequences. Full article

Background: Colorectal cancer (CRC) remains a major clinical challenge, in part due to the limited efficacy of 5-fluorouracil (5-FU)-based chemotherapy, which is often compromised by the emergence of acquired resistance. Aronia berry extract (ABE), a phenolic-rich natural compound, has gained increasing attention for its anticancer and chemosensitizing properties. This study aimed to investigate whether ABE can overcome 5-FU resistance (5-FU-R) in CRC and to elucidate the molecular mechanisms underlying its therapeutic effects. Methods: We conducted a series of in vitro experiments using 5-FU-R CRC cell lines to evaluate the synergistic effects of combined ABE and 5-FU treatment. Genome-wide transcriptomic profiling was performed to identify key regulatory pathways associated with chemoresistance and to determine potential ABE-responsive targets. Findings were further validated using patient-derived 3D organoids (PDOs). Results: Co-treatment with ABE and 5-FU significantly reduced the effective concentration of 5-FU required to inhibit 5-FU-R CRC cells, yielding a Bliss synergy score greater than 10. The combination markedly suppressed cell viability, clonogenic potential, migration, and invasion. ABE also reduced cancer stemness, as evidenced by reduced CD44, Nanog, and Oct4 expression. Functional inhibition of Toll-like receptor 3 (TLR3) impaired spheroid growth, and PDO experiments corroborated these findings, demonstrating reduced organoid growth, diminished survival, and decreased NF-κB expression following ABE treatment. Conclusions: Our findings reveal that ABE effectively overcomes 5-FU resistance in CRC by targeting the TLR3/NF-κB signaling axis. This study highlights ABE as a safe, accessible, and promising adjunctive strategy to enhance therapeutic responses in 5-FU-resistant CRC. Full article

Background: Particulate matter (PM_2.5) inhalation induces pulmonary disorders through oxidative stress. Veratramine (VRT), a steroidal alkaloid derived from Veratrum species, exhibits protective pharmacological potential. Therefore, this study aims to investigate the protective effects of VRT against PM_2.5-induced oxidative injury and the underlying molecular mechanisms. Methods: In vitro experiments were conducted using pulmonary artery endothelial cells (HPAECs), which were exposed to PM_2.5 (25–100 μg/mL) ± VRT (2–50 μM) or Dexamethasone (DEX; 50 μM) for 24–48 h. Measurements included 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide viability, Lactate dehydrogenase ELISA, 2′,7′-dichlorodihydrofluorescein diacetate reactive oxygen species (ROS), superoxide dismutase/catalase kits, and Western blots (Bax, serum, and glucocorticoid-regulated kinase 1 (SGK1), microtubule-associated protein 1 light chain 3 (LC3), Toll-like receptor (TLR4), and mechanistic target of rapamycin (mTOR)). Results: PM_2.5 exposure reduced HPAEC viability in a dose- and time-dependent manner, likely due to increased lactate dehydrogenase leakage and intracellular ROS accumulation. Oxidative stress correlated with altered superoxide dismutase and catalase activities, with suppression of SGK1, a key factor in cell survival. VRT treatment enhanced cell viability, mitigated oxidative stress, and restored SGK1 expression. Moreover, VRT promoted mTOR phosphorylation and markedly suppressed PM_2.5-induced increases in TLR4, MyD88, and the autophagy markers LC3 II and Beclin 1. Conclusions: Collectively, these findings indicate that VRT protects against PM_2.5-induced pulmonary injury by modulating oxidative stress and the mTOR-associated autophagy pathway, highlighting its potential as a therapeutic candidate for PM_2.5-related respiratory disorders. Full article

Controlled local hyperthermia supports postoperative wound healing in liver surgery by stimulating metabolism, angiogenesis, and immune responses through the induction of heat shock proteins (HSPs) and modulation of Damage-Associated Molecular Patterns (DAMPs). This study evaluates the impact of thermal modulation on immune processes during abdominal wound repair, specifically analyzing the role of HSPs and immune activation pathways. A narrative review of the literature from 2010 to 2025 was conducted to summarize molecular mechanisms regarding temperature, HSP activation, cytokine expression, and DAMPs, excluding studies conducted solely in animal models. The results indicate that precise local hyperthermia in postoperative abdominal wounds activates HSPs as well as inflammasome and Toll-like receptor (TLR) pathways, modulating immune and cytokine responses depending on the type and depth of tissue injury. Consequently, such thermoimmunomodulation stabilizes immune cell functions, optimizes the balance between inflammation and regeneration, and minimizes the risk of postoperative complications to support effective wound healing. Full article

This study investigates the genomic basis of immune adaptation in the transparent glass catfish (Kv: Kryptopterus vitreolus), focusing on the loss of the Toll-like receptor 21 (TLR21) gene. Comparative genomic analysis with closely related non-transparent North African catfish (Cg: Clarias gariepinus) revealed 11 TLR genes in the latter, while only 8 TLR genes (KvTLR1, 2, 3, 5, 7, 9, 13, and 20) were retained in the glass catfish, with TLR21 specifically absent. Collinearity analysis confirmed that the genomic region containing TLR21 is conserved across eight siluriform species, with loss exclusively in the glass catfish, supporting its lineage-specific absence. Structural expansion was notable in KvTLR5, KvTLR7, and KvTLR20. Molecular docking indicated that binding stability between CpG oligonucleotides and TLR21 varies significantly, with CpG-B 1681 showing the strongest interaction, which highlights sequence-dependent ligand recognition. Interestingly, absence of the TLR1 gene in another transparent teleost, the X-ray tetra (Pristella maxillaris), suggests that transparent fishes may share an evolutionary trend of lineage-specific TLR gene loss. Together, these findings reveal a distinctive evolutionary trajectory in the innate immune receptor family of transparent fishes and provide new molecular insights into their adaptive immune strategies. These insights will benefit the academic community by improving comparative frameworks for fish innate immunity, and they may inform disease prevention and health management strategies in aquaculture and the ornamental fish trade. Full article

Recent studies have increasingly indicated that postoperative complications after esophagectomy are correlated with poor long-term prognoses, making it crucial to prevent such complications. Based on our studies, we believe that central to this issue is the finding that among esophageal cancer patients who experience postoperative complications and have poor long-term prognoses there is a high incidence of poor oral environments. Here we review the results of our basic and clinical research studies, as well as evidence from other institutions, on the oral environment of esophageal cancer patients and its association with the incidence of complications and long-term prognoses. We hope these findings, which suggest “improving the oral environment of esophageal cancer patients can reduce the incidence of postoperative complications and improve long-term prognoses”, will gain consensus and lead to safer esophageal cancer surgery. Full article

High Mobility Group ^{Box 1} (HMGB1) and S100 proteins are major ligands of Receptor for Advanced Glycation End-products (RAGE) and have causal roles in endometriosis lesions. Yet the AGE–RAGE pathway that unifies Advanced Glycation End-products (AGEs) with these ligands has not been assessed in endometriosis. In diabetes, atherosclerosis, and chronic kidney disease, AGE–RAGE links insulin resistance and oxidative stress to inflammation, fibrosis, and organ harm. Endometriosis shares key drivers of AGE accumulation, including insulin resistance, oxidative stress, and chronic inflammation. Endometriosis is also linked to higher vascular risk and arterial stiffness. We asked whether AGE–RAGE could bridge metabolic stress to pelvic lesions and systemic risk. We did a focused review of mechanisms and an evidence map of studies on AGEs, RAGE, or known RAGE ligands in endometriosis. We grouped findings as most consistent with a driver, amplifier, consequence, or parallel role. We included 29 studies across human samples, cell systems, and animal models. Few studies measured AGE adducts directly. Most work tracked RAGE ligands (mainly HMGB1 and S100 proteins) and downstream immune and angiogenic programs. Across models, this pattern fits best with a self-reinforcing loop after lesions form. RAGE expression often aligned with lesion remodeling, especially fibrosis. Blood and skin readouts of AGE burden were mixed and varied by cohort and sample type. A central gap is receptor proof. Many models point to shared Toll-like receptor 4 (TLR4)/ nuclear factor kappa B (NF-κB) signaling, but few test RAGE dependence. Overall, current evidence supports AGE–RAGE as a disease-amplifying loop involved in chronic inflammation and fibrosis rather than an initiating trigger. Its effects likely vary by stage and site. Priorities now include direct lesion AGE measurement, paired systemic–pelvic sampling over time, receptor-level studies, and trials testing diet or drug interventions against clear endpoints. Outcomes could include fibrosis, angiogenesis, immune state, pain, and oocyte and follicle function. Full article

Mucosal-associated invariant T (MAIT) cells exist in high numbers in the body and have a unique and highly conserved T cell receptor (TCR). They can be activated in a TCR-dependent manner by ligands presented on the monomorphic protein MHC class I-related protein 1 (MR1) which is found on many cell types, including professional antigen presenting cells (APCs) and epithelial cells. This has sparked interest in the potential to exploit the MR1-MAIT cell axis for the development of vaccines against infectious disease. Within this context an MR1 ligand, typically 5-(2-oxopropylideneamino)-d-ribitylaminouracil (5-OP-RU), is administered with or without a Toll-like receptor (TLR) ligand or cytokine in a pan vaccination approach that would prime the immune response to provide protection against a variety of bacterial and viral pathogens. This strategy has led to enhanced protection in murine models of Legionella longbeachae, Francisella tularensis, Klebsiella pneumoniae, Streptococcus pneumoniae and influenza infection. However, studies against Mycobacterium tuberculosis infection have proven less successful. The second vaccination approach involves pairing the MR1 ligand with more conventional antigens that could activate CD4⁺ and/or CD8⁺ T cells. This approach has been successful in murine models of cholera, influenza, and SARS-CoV-2, including in the context of subunit vaccines. However, there are several challenges when using MR1-MAIT cell-mediated vaccine adjuvants. These include the inherent instability of 5-OP-RU and the need for more advanced studies to better understand how the use of MR1 ligands would translate to applications in humans. This review will discuss these aspects and highlight the mechanistic studies that have been undertaken to understand how MAIT cells might elicit their effects within the context of MAIT cell-mediated vaccines for infectious disease. Full article

Conflicting data exist regarding the effect of intradetrusor BoNT/A on the incidence of urinary tract infections (UTIs) in patients with neurogenic detrusor overactivity (NDO), contrary to the increase in UTIs noted in patients with idiopathic OAB. Associations between UTIs, chronic inflammation, and bladder overactivity are acknowledged, albeit not fully understood. Chronic bladder inflammation is common in both NDO and OAB patients, and both animal and human studies suggest a beneficial effect of BoNT/A on both urinary and systemic levels of inflammatory markers. To explore whether intradetrusor BoNT/A injections affect the background for the incidence of UTIs in humans, we investigated in parallel the effect of intradetrusor BoNT/A on the incidence of UTIs and on the urine mRNA levels of urinary pathogen-detecting Toll-like receptors TLR2, TLR4, and TLR5 and of factors acting as intermediates of immune response and promoters of inflammatory reactions (IL1β, IL6, TNFα, and PGE₂). For this purpose, we recruited 22 patients with NDO-associated incontinence who received at least one bladder BoNT/A injection. Urine specimens for the study of UTIs were obtained before the procedure and at routine urodynamic follow-ups at 4–6 weeks, 6 and 12 months post-BoNT/A, and at clinical relapse, while urine specimens for the study of biomarkers were collected at the time of BoNT/A injection and at the abovementioned follow-ups thereafter. Urine specimens from 10 adult healthy volunteers with no OAB symptoms served as the control group in the biomarker study. The genes of interest in the urine were studied by RNA isolation, reverse transcription, and real-time PCR. The urine mRNAs of all biomarkers tested appeared to be upregulated in the patients’ samples compared with the controls, albeit only TLR2 and TLR5 mRNA increases were statistically significant. A progressive downregulation of TLR2, TLR5, IL1β, and IL6 urine mRNAs was noted at one and six months post-BoNT/A. TNFα and PGE₂ mRNAs showed a transient increase at one month post-BoNT/A followed by a dramatic drop at the six months’ follow-up. A similar trend for progressive decline was also noticed in the prevalence of both positive urine cultures and symptomatic UTIs in the same timepoints and additionally at 12 months post-treatment in patients who still benefited from the BoNT/A treatment. Upon clinical relapse, the mRNA levels of PGE₂, IL1β, and IL6 increased in parallel with an increase in the prevalence of UTIs, while the levels of TLRs and TNF-α did not follow the same trend. In summary, intradetrusor BoNT/A injections achieved significant decreases in the urine mRNA levels of pathogen-detecting TLRs, immune response, and inflammation mediator cytokines and PGE₂ in our cohort of patients with NDO-associated incontinence. In parallel, decreases were noted in both the incidence of symptomatic UTIs and rates of positive urine cultures. At the time of clinical relapse, the markers of inflammation and immune response, but not TLRs, were upregulated in parallel with the increased incidence of UTIs, suggesting that the studied genes PGE₂, IL1β, and IL6 could be further explored as potential biomarkers for inflammation/immune response and UTIs in the neurogenic population. Full article

Background/Objectives: While new vaccines are in development; one strategy to increase influenza vaccine coverage is to repurpose current influenza vaccines for intranasal delivery. Methods: To address this goal; mice were vaccinated intranasally with either a split inactivated virus vaccine (Fluzone) or a recombinant HA vaccine (Flublok) at one of two doses (1 μg high dose or 0.1 μg low dose). Both vaccines were adjuvanted with either a STING agonist; c-di-AMP (CDA); or a combination of a synthetic toll-like receptor (TLR) 4 and TLR7/8 agonist (TRAC478). Results: Mice vaccinated with either vaccine plus adjuvant had higher hemagglutination-inhibition titers than mice administered unadjuvanted vaccines. Mice vaccinated with either vaccine plus CDA had on average higher numbers of H3 and influenza B hemagglutinin (HA)-specific antibody-secreting cells (ASCs); whereas mice vaccinated with vaccine plus TRAC478 had on average higher number of H1 HA-specific ASCs. All vaccinated mice challenged with the H1N1 influenza virus were protected against both morbidity and mortality with no detectable virus in their lungs. Mice challenged with the H3N2 influenza virus all lost weight over the first 5 days of infection. Adding TRAC478 with either a high or low dose vaccine resulted in 80–100% survival following challenge. Almost all mice vaccinated with Flublok plus CDA died from H3N2 influenza virus challenged with ~2 logs higher viral lung titers than mice administered Flublok only or Flublok plus TRAC478. Conclusions: Overall; Fluzone and Flublok can effectively be used for intranasal vaccination. Full article

Viral RNA structure plays a critical regulatory role in viral replication, serving as a dual-purpose mechanism for encoding genetic information and controlling biological processes. However, these structural elements also serve as pathogen-associated molecular patterns (PAMPs), which are recognized by pattern recognition receptors (PRRs) of the host innate immune system. This review discusses the complex and poorly understood relationship between viral RNA structure and recognition of RNA by PRRs, specifically focusing on Toll-like receptor 3 (TLR3) and Retinoic acid-inducible gene I (RIG-I). While current interaction models rely upon data generated from use of synthetic ligands such as poly(I:C) or perfectly base-paired double-stranded RNA stems, this review highlights significant gaps in our understanding of how PRRs recognize naturally occurring viral RNAs that fold into highly complex three-dimensional structures. Furthermore, we explore how viral evolution and nucleotide variations, such as those observed in influenza viruses, can drastically alter local and distal RNA structure, potentially impacting immune detection. We conclude that moving beyond synthetic models to understand natural RNA structural dynamics is essential for elucidating the mechanisms of viral immune evasion and pathogenesis. Full article

Tylorrhynchus heterochaetus is an aquatic food with both edible and medicinal value in China. With a protein-rich body wall, it has strong potential for producing bioactive peptides. To explore its potential as a source of immunomodulatory peptides, in this study, flavor enzymes were selected as the optimal hydrolases, and the hydrolyzed products were subjected to ultrafiltration fractionation. The <3000 Da portion exhibited the most effective immune-stimulating activity in RAW 264.7 macrophages, enhancing phagocytosis and promoting the secretion of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and nitric oxide (NO) in a concentration dependent manner. Peptide omics analysis, combined with the activity and safety screened by bioinformatics, identified 43 candidate peptides. Molecular docking predicts that three novel peptides, LPWDPL, DDFVFLR and LPVGPLFN, exhibit strong binding affinity with toll-like receptor 4/myeloid differentiation factor-2 (TLR4/MD-2) receptors through hydrogen bonding and hydrophobic/π stacking interactions. Synthetic verification confirmed that these peptides were not only non-toxic to cells at concentrations ranging from 62.5 to 1000 µg/mL, but also effective in activating macrophages and stimulating the release of immune mediators. This study successfully identified the specific immunomodulatory peptides of the Tylorrhynchus heterochaetus, supporting its high-value utilization as a natural source of raw materials for immunomodulatory functional foods. Full article