Search Results (372)

Background/Objectives: Aseptic loosening (AL) is among the most common causes of late failure following total hip arthroplasty (THA), often necessitating complex revision surgery. Current diagnostic tools, mainly based on clinical and radiological findings, are primarily able to identify advanced changes of periprosthetic osteolysis (PPOL). Therefore, early detection of AL remains a challenge. Circulating microRNAs (miRNAs) have emerged as promising, minimally invasive biomarkers in musculoskeletal disorders. This study investigates the expression of inflammation-related miRNAs let-7i-5p, let-7e-5p, miR-15a-5p, miR-30a-3p and miR-130a-3p in patients with confirmed AL after THA to evaluate their potential role in AL. Methods: AL patients undergoing revision were compared with asymptomatic post-THA individuals and controls with degenerative osteoarthritis. Preoperative, peripheral blood samples were collected; total RNA was extracted; and quantitative real-time PCR (qRT-PCR) was performed to quantify miRNA expression. The relative expression of miRNAs was calculated using the 2–ΔΔCt method after proper normalization of Ct values. Statistical analysis assessed differences between groups. Results: The under investigation miRNAs exhibited distinct expression patterns. Several targets demonstrated significant downregulation in AL patients, suggesting a potential link to inflammatory and osteolytic pathways like Toll-like receptor 4 (TLR4)–Nuclear Factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling, NLRP3 inflammasome activation and macrophage polarization. Conclusions: The observed alterations in circulating miRNAs support their capability as biomarkers for early detection of AL following THA. Larger cohorts could facilitate translation into routine clinical diagnostics. Full article

Background/Objectives: Preclinical and clinical evidence supports a chaperone-based vaccination platform for cancer immunotherapy. The objective of this study is to interrogate the next generation of chaperone-based immune modulator, termed Flagrp170, which was constructed by fusing a defined NF-κB-activating microbial sequence with a large stress protein with a superior antigen-holding/presenting property in the setting of antigen-targeted cancer vaccination. Methods: Bone marrow-derived dendritic cells were treated with Flagrp170 protein or an unmodified parental chaperone molecule (i.e., Grp170), followed by an analysis of DC activation and DC-mediated T cell priming using both in vitro and in vivo models. Antitumor vaccine responses in mice receiving tumor antigens (e.g., gp100, Her2/neu) complexed with Flagrp170 or Grp170 were examined through multiple immune assays. The potential use of a Flagrp170-based chaperone vaccine to sensitize tumors to anti-PD-1 therapy was also evaluated. Results: Flagrp170 not only retains the intrinsic ability of the parent chaperone to facilitate antigen cross-presentation, but also acquires a unique capacity to stimulate DCs efficiently through the engagement of TLR5-NF-κB signaling. This chimeric chaperone shows superior activity compared to the unmodified parental molecule, resulting in enhanced DC activation and T cell priming. Vaccination with Flagrp170 complexed to tumor antigens induces a robust T cell response against primary tumors and metastases, a process critically dependent on CD8⁺ DCs. Additionally, the Flagrp170 chaperone vaccine can efficiently generate and expand tumor-reactive T cells. The consequent remodeling of the tumor microenvironment towards a Th1/Tc1 dominant immune phenotype significantly potentiates cancer responsiveness to anti-PD1 therapy. Conclusions: Given the safety and T cell stimulation profiles of the chaperone–antigen complex vaccine already established in our recent clinical trial, this new generation of chaperone cargo, capable of delivering both antigenic targets and pathogen-associated immunoactivating signals simultaneously, represents a promising strategy to potentially improve the low response rates in patients receiving immune checkpoint inhibitors. Full article

Vaccine adjuvants play a crucial role in the field of vaccinology, yet they remain one of the least developed and poorly characterized components of modern biomedical research. The limited availability of clinically approved adjuvants highlights the urgent need for new molecules with well-defined mechanisms and improved safety profiles. Hemocyanins, large copper-containing metalloglycoproteins found in mollusks, represent a unique class of natural immunomodulators. Hemocyanins serve as carrier proteins that help generate antibodies against peptides and hapten molecules. They also function as non-specific protein-based adjuvants (PBAs) in both experimental human and veterinary vaccines. Their mannose-rich N-glycans allow for multivalent binding to innate immune receptors, including C-type lectin receptors (e.g., MR, DC-SIGN) and Toll-like receptor 4 (TLR4), thereby activating both MyD88- and TRIF-dependent signaling pathways. Hemocyanins consistently favor Th1-skewed immune responses, which is a key characteristic of their adjuvant potential. Remarkably, their conformational stability supports slow intracellular degradation and facilitates dual routing through MHC-II and MHC-I pathways, thereby enhancing both CD4+ and CD8+ T-cell responses. Several hemocyanins are currently being utilized in biomedical research, including Keyhole limpet hemocyanin (KLH) from Megathura crenulata, along with those from other gastropods such as Concholepas concholepas (CCH), Fissurella latimarginata (FLH), Rapana venosa (RvH), and Helix pomatia (HpH), all of which display strong immunomodulatory properties, making them promising candidates as adjuvants for next-generation vaccines against infectious diseases and therapeutic immunotherapies for cancer. However, their structural complexity has posed challenges for their recombinant production, thus limiting their availability from natural sources. This reliance introduces variability, scalability issues, and challenges related to regulatory compliance. Future research should focus on defining the hemocyanin immunopeptidome and isolating minimal peptides that retain their adjuvant activity. Harnessing advances in structural biology, immunology, and machine learning will be critical in transforming hemocyanins into safe, reproducible, and versatile immunomodulators. This review highlights recent progress in understanding how hemocyanins modulate mammalian immunity through their unique structural features and highlights their potential implications as potent PBAs for vaccine development and other biomedical applications. By addressing the urgent need for novel immunostimulatory platforms, hemocyanins could significantly advance vaccine design and immunotherapy approaches. Full article

Vaccines have emerged as one of the most effective biomedical strategies for the eradication of diseases. However, a significant limitation remains in their ability to induce comprehensive humoral and cellular immune responses. Recently, nanoparticles (NPs) have been advanced as a novel vaccine delivery approach to address reduced immunogenicity. Several nanoparticle-based agents have now been approved for human use, and NP-based formulations have shown remarkable potential to enhance immunogenicity and stability, supporting targeted delivery and controlled release either through co-encapsulation of adjuvants such as Toll-like receptor (TLR) agonists or the inherent immune-stimulatory properties of NP materials in minimizing cytotoxicity. Despite these advances, there remains a pressing need for vaccines capable of addressing complex and multifactorial diseases such as neurological disorders and cancer. Nanotechnology could be a viable solution to this challenge. The use of lipid-based NPs, particularly those encapsulating mRNA, has garnered attention for its adaptability in vaccine delivery. Current studies indicate that NP composition, surface charge and size may play a crucial role in modulating biodistribution, delivering immune-stimulatory molecules, targeting antigens and trafficking antigen-presenting cells (APCs), which enhance immune responses across mucosal and systemic tissues. This review highlights recent advancements in NP-based vaccines and delivery systems, and adjuvants for cancer and neurological disorders. The review also covers an overview of NP-based and alternative delivery systems, focusing on the mechanisms and innovations related to NP-based systems for immunotherapeutic applications in cancer and neurological disorders. Full article

Tenascin-C (TNC) is a complex extracellular matrix (ECM) protein that plays a critical role in regulating cellular adhesion, motility, proliferation, and inflammation through its interaction with Toll-like receptor 4 (TLR4) and other receptors. The upregulation of TNC is associated with inflammatory responses, autoimmune disorders, and neoplastic conditions during both physiological and pathological tissue remodeling. In the central nervous system (CNS), TNC contributes to neuroinflammatory processes by modulating the function of immune cells and the secretion of pro-inflammatory mediators, thereby playing a pivotal role in the initiation and progression of neuroinflammatory diseases. TNC is expressed in astrocytes, neural progenitor cells, and various neuronal populations within both developing and mature CNS regions. It regulates neuronal migration and axonal guidance during neurogenesis, facilitating synaptic plasticity and CNS regeneration. Furthermore, TNC enhances neuroplasticity through interactions with receptor families, such as integrins, to establish the molecular connections necessary for cell communication and signal transduction. This review investigates the mechanistic properties of TNC, focusing on its spatiotemporal expression, molecular interactions with receptors, and its role in neurological disorders, in addition to its modulatory capacity in neuroplastic processes. Additionally, this review delves into recent research advancements with respect to neuroinflammation involving TNC, along with therapeutic strategies targeting TNC. Full article

Alzheimer’s disease (AD) has been studied extensively and is characterized by plaques deposited throughout the brain. Plaques are made of beta-amyloid (Aβ) peptides which have undergone fibrillogenesis to form insoluble Aβ fibrils (fAβ) that are neurotoxic. Receptor for Advanced Glycation End end products (RAGE), toll-like receptors (TLRs) 2 and 4, and co-receptor CD14 recognize negatively charged binding regions on fAβ to activate microglia and release proinflammatory cytokines. In this study, we used two experimentally resolved fAβ structures (type I and II) isolated from AD brain tissue to elucidate binding patterns of fAβ with RAGE, TLR2, TLR4, and CD14 and investigated whether binding was affected by fibril structure or system pH. Receptors TLR2 and RAGE formed tight complexes with both type I and II fibrils, while TLR4 showed selectivity for type I. CD14 binding was less tight and selective for type II. Binding was pH dependent for CD14, TLR4, and RAGE but not TLR2. We explored the effects of familial mutations on fibril structure to determine whether mutants of type I or II structures are feasible. Finally, we investigated whether mutations affected binding interactions of fAβ with proteins. The Arctic (Glu22Gly), Dutch (Glu22Gln), and Iowa (Asp23Asn) mutations showed similar effects on binding affinity. Italian (Glu22Lys) mutations abrogated binding, whereas type I and II fibrils with Flemish (Ala21Gly) mutations were not shown to be feasible. Results highlight the adaptability of immune receptors in recognizing damaging molecules, with fibril structure and pH being the main recognition determinants predicated on disease progression. In silico mutations showed that aggregates similar to type I and II structures were plausible for some familial mutations. Full article

Bioactive glycopeptides, commonly present in natural foods, exhibit notable immunomodulatory and neuroprotective effects. However, naturally occurring low-molecular-weight glycopeptides have rarely been reported, and their structural and functional properties remain insufficiently explored. In this study, a low-molecular-weight glycopeptide complex (GLP-P) was isolated from kefir. The structure of GLP-P was characterized via molecular weight (Mw) determination, monosaccharide and amino acid composition analysis, Fourier transform infrared spectroscopy, methylation analysis, and nuclear magnetic resonance spectroscopy. GLP-P had a molecular weight of 1192 Da and mainly consisted of four monosaccharides (glucose 64.7%, galactose 34.4%, and others 2.0%) and eight amino acids (asparagine 30.89 ± 0.01 μg/mg, threonine 8.71 ± 0.04 μg/mg, serine 9.5 ±0.08 μg/mg and others.). The primary chain structure of GLP-P contained β-D-Galp-(1→4)-β-D-Glcp-(1→4)-α/β-D-Glcp linkages, including both α- and β-D-Glcp isomers. Notably, the HMBC spectrum of GLP-P exhibits putative O-glycosylation characteristics. Functionally, GLP-P significantly reduced IL-6 and TNF-α expression while enhancing IL-10 in LPS-stimulated RAW264.7 macrophages. These effects were associated with inhibition of the TLR4/NF-κB pathway. These findings suggest that low-molecular-weight GLP-P has shown potential efficacy in the treatment of inflammation in vitro. These results provide a theoretical basis for kefir glycopeptide development of functional foods and as an adjuvant therapeutic agent for inflammation-related disorders in the future. Full article

In modern livestock, the demand for sperm sex selection technologies is high, as the ability to deliberately produce offspring of a specific sex offers significant economic advantages. Traditionally, sperm sorting is performed using Fluorescence-Activated Cell Sorting. However, the flow cytometric method is expensive, technically complex, and associated with reduced sperm viability. An alternative promising method involves the use of Toll-like TLR7/8 receptors for the selective binding of spermatozoa of a particular sex. It was discovered previously that the activation of TLR7/8 by its ligand(s) selectively inhibits the motility of X-bearing sperm without affecting the motility of Y-bearing sperm. The swim-up technique, which separates sperm based on sex chromosome type by isolating fractions enriched in either X- or Y-bearing gametes due to differences in their motility, can be used with this method. Sperm sex sorting via the TLR7/8 activation is cheap, technically non-complex, and does not affect sperm viability negatively. The goal of this review is to provide an overview of the TLR7/8-dependent sperm sorting method. Further, we discuss why the method of sperm sorting via TLR7/8 activation is successfully implemented in some animal species (such as murine, caprine, ovine, and bovine) but fails in others, like swine and canine. Full article

Epilepsy is one of the most prevalent and disabling neurological disorders, affecting approximately one percent of the population. Due to the complex pathophysiology underlying drug-resistant epilepsy, nearly one-third of patients with epilepsy do not benefit from current treatments. Neuroinflammation is one of the most well-studied pathways in epileptogenesis, and inflammatory mediators play a crucial role in this process. The IL-1β/IL-1R1/IL-1Ra and HMGB1/TLR4 pathways play significant roles in epileptogenesis in both animal and human studies. Interventional investigations on the IL-1β/IL-1R1/IL-1Ra and HMGB1/TLR4 pathways showed antiseizure effects, suggesting that these pathways could be therapeutic targets for epilepsy. However, related targeted treatments are limited in clinical practice. In this work, we evaluated the advances of the IL-1β/IL-1R1/IL-1Ra and HMGB1/TLR4 pathways in epileptogenesis, as well as clinical trials or interventional investigations of current medications or substances targeting these pathways. To facilitate clinical translation, we highlighted the gap between research advancements and clinical practice and presented several strategies for closing the gap to fulfill the urgent requirements of patients with epilepsy. Full article

Periodontitis has been associated with adverse pregnancy outcomes, but the effect of oral pathogens on placental tissue and local immunity remains unclear. In this study, we investigated the response of human placental explants (HPEs) to lysates of Porphyromonas (P.) gingivalis, a keystone periodontal pathogen. Exposure to P. gingivalis induced significant histological damage and extracellular matrix degradation in placental tissue. The lysate activated the canonical NF-κB pathway, as demonstrated by increased phosphorylation of IκBα, particularly in the trophoblast. This activation was predominantly mediated by Toll-like receptor 2 (TLR-2), with partial contribution from TLR-4. Notably, TLR-2 protein levels decreased upon stimulation, while soluble (s) TLR-2 was markedly elevated in culture supernatants, suggesting receptor cleavage as a regulatory mechanism. P. gingivalis also triggered a robust proinflammatory cytokine secretion, including IL-1β, IL-6, IL-8, and TNF-α, with variable dependence on TLR-2 and TLR-4 signaling. These findings reveal that P. gingivalis components elicit a complex innate immune response in the placenta, driven by TLR-mediated NF-κB activation and modulated by sTLR-2. This study provides mechanistic insight into how periodontitis may contribute to placental inflammation and highlights potential pathways linking maternal oral health to pregnancy complications. Full article

Bacteroides fragilis, a prominent commensal of the human gut microbiota, plays a vital role in immune system regulation through its capsular polysaccharide A (PSA), which requires a glycolipid anchor structurally reminiscent of lipid A. While canonical Escherichia coli lipid A acts as a potent TLR4 agonist contributing to septic shock and inflammatory disorders, certain B. fragilis-derived glycolipids demonstrate antagonistic effects, offering potential as anti-inflammatory agents. In this study, we report the synthesis and preliminary computational evaluation of a library of glycolipids inspired by B. fragilis lipid A. Three lipid As, including a tetra-acylated 1-phosphoryl lipid A analog (Tetra C-1), were synthesized and assessed using molecular docking simulations targeting the human TLR4/MD-2 complex. Docking results reveal that Tetra C-1 exhibits more favorable antagonist binding characteristics compared to the well-studied TLR4 antagonist Eritoran. This work highlights a microbiota-informed strategy for the development of novel TLR4 antagonists, potentially enabling targeted modulation of innate immunity for therapeutic applications in inflammatory diseases and as vaccine adjuvants. Full article

The bacterial flagellum plays a crucial role in pathogenesis. However, the mechanism by which the flagellum interferes with host energy metabolism remains unclear. In this study, we confirmed that deletion of the fliC gene resulted in a 30% reduction in the virulence of Pseudomonas plecoglossicida against the large yellow croaker (Larimichthys crocea). Compared to the wild-type strain (WT) infection group, the ΔfliC infection group exhibited a 29.54% decrease in the number of vacuolar degeneration hepatocytes and a 50.83% higher liver glycogen content. Furthermore, infection led to decreased mitochondrial complex V activity, a reduced NAD+/NADH ratio, lower levels of reduced glutathione (GSH), and increased lipid peroxide levels; however, these metabolic perturbations were significantly ameliorated in the ΔfliC group compared to the WT group. Proteomic analysis revealed that the dysregulation of the complement cascade and core carbon metabolic pathways observed in the WT infection group liver was significantly alleviated in the ΔfliC infection group. Additionally, in the ΔfliC infection group, pro-inflammatory genes (such as Tlr5, Tnfα, and Il1β) were downregulated, while lipid metabolism-related genes (such as Acox1, Cpt1a, and Pparα) were upregulated, suggesting the suppression of the Tlr5/NF-κB immune signaling axis and enhanced fatty acid β-oxidation. Collectively, fliC may mediate the disruption of host glucose and lipid metabolism homeostasis through a Tlr5-triggered immunometabolic regulatory axis. In conclusion, this study demonstrates that bacterial flagella modulate host energy metabolism, expanding our understanding of flagellum-mediated pathogenesis. Full article

Background/Objectives: Pyrogens, fever-inducing substances from biological or environmental sources, are recognized by Toll-like receptors (TLRs) predominantly expressed by human monocytes and represent a critical quality attribute (CQA) for pharmaceutical safety. The rabbit pyrogen test (RPT), widely used for pyrogen assessment, suffers from high variability, limited accuracy, and poor reproducibility, particularly for vaccines containing inherent pyrogens such as outer membrane protein complex (OMPC)-based vaccines. Existing in vitro alternatives using peripheral blood mononuclear cells (PBMCs) are challenged by donor-to-donor variability and the operational complexity of ELISA readouts. To support the 3Rs (Refinement, Reduction, Replacement) and provide a more reliable quality control (QC) method, we developed a reporter cell–based monocyte activation test (MAT) suitable for release testing. Methods: We screened human monocytic reporter cell lines engineered with NFκB-responsive promoter elements driving a luminescent reporter. Reporter cells were treated with diverse endotoxin and non-endotoxin pyrogens and luminescence was quantified after stimulation. Selected THP-1-derived reporter cells were used to develop an MAT for OMPC. Assay performance was evaluated following validation guidelines: linearity, accuracy, precision, analytical range (relative to a reference lot), and robustness under deliberate parameter variations. Results: The THP-1 reporter cells could detect a wide range of pyrogens via simple luminescence readouts. For OMPC testing, the MAT demonstrated strong linearity (R² ≥ 0.99), accuracy with relative bias within ±10.3%, and high precision (overall %RSD ≤ 6.9%) across the 25–300% range. Deliberate variations in assay parameters did not materially affect performance, indicating robustness appropriate for routine release testing. Conclusions: The implementation of reporter cell-based MAT assays enhances consistency, reliability, and efficiency in evaluating the pyrogenicity and safety of drug products, supporting global initiatives to minimize animal testing while ensuring regulatory compliance. Full article

Ultraviolet B (UVB) radiation triggers DNA damage and immune suppression, establishing conditions favorable for skin carcinogenesis. Previous studies have shown that a downstream adaptor for Toll-like receptors (TLRs), myeloid differentiation primary response 88 (MyD88), plays a role in UVB-induced DNA damage and immunosuppression. However, specific mechanisms for the effects on dendritic cells and T cells remain poorly understood. The objective of this study is to determine the role of MyD88 and TIR-domain-containing adaptor inducing interferon-β (TRIF), another key TLR downstream adaptor, in UVB-induced suppression of dendritic cell activity and T cell function. MyD88−/−, Trif−/−, and wild-type (WT) mice were evaluated for UVB-induced effects on dendritic cell, T cells, and contact hypersensitivity responses in skin. MyD88−/− mice exhibited significant resistance to UVB-induced immune suppression, compared to Trif−/− mice and wild-type controls. The MyD88 deficiency significantly reduced UVB-induced Treg cells that were CD4⁺CD25⁺Foxp3⁺ and produced interleukin (IL)-10. Moreover, it significantly inhibited the UVB-induced suppression of IL-12/IL-23 producing CD11c⁺ dendritic cells. Further experiments confirmed that MyD88 conditional knockout (MyD88fl/flXCD11c.Cre) mice were protected against UVB-induced immune suppression. Dendritic cells from MyD88 genomic or conditional knockout mice were resistant to UVB-induced reduction of major histocompatibility complex (MHC) class II antigens. These findings show that MyD88 plays a key role in UVB-induced immune suppression. The deficiency in the MyD88 gene inhibits UVB-induced suppression of CD11c+ dendritic cell (DC) activity and reduces UVB-induced development of Treg cells. Our studies demonstrate a new mechanism for MyD88-mediated regulation of UVB-induced immune suppression. Full article

Curcumin, the principal bioactive compound derived from turmeric, possesses a wide range of therapeutic properties such as anti-inflammatory, antioxidant, and wound-healing properties. Recent studies suggest that curcumin may alleviate HMGB1-mediated inflammation in ovarian cells. However, its role in modulating dysfunction in HMGB1-driven ovarian granulosa cells (OGCs) remains to be elucidated. In the present study, curcumin suppresses the HMGB1-induced overexpression of toll-like receptor 2 (TLR2) and ovulation-related factors such as EGFR, VEGF, STAR, and TIMP1/2 genes. Additionally, the elevated levels of TLR2, TLR1, TLR6, and phospho-NF-κB p65 proteins were significantly inhibited by curcumin. Further mechanistic analysis reveals that the interaction between HMGB1 and the TLR1-TLR2/TLR6 complex, as well as phospho-NF-κB p65, was restrained. This resulted in the suppression of the pro-inflammatory cytokine IL-6 production and the alleviation of the HMGB1-induced inflammation response in OGCs. Collectively, our findings demonstrate that curcumin modulates the upregulation of ovulation-related genes and pro-inflammatory cytokines in OGCs by inhibiting the TLR2-NF-κB pathway, providing a mechanistic basis for its potential application as a therapeutic agent against OGC inflammation. Full article