Search Results (117)

Alternating glycopolymers bearing periodically arranged pendant carbohydrate residues were synthesized by reversible addition–fragmentation chain transfer (RAFT) copolymerization of maltose-containing vinyl ether (MalVE) and ethyl maleimide (EtMI). The resulting trithiocarbonate-terminated polymers were subsequently converted into thiol-terminated glycopolymers through post-polymerization end-group transformation. These structurally well-defined alternating glycopolymers were immobilized onto gold nanoparticles (AuNPs) via Au–S interactions to construct glycopolymer-functionalized glycointerfaces. Surface functionalization of the AuNPs was confirmed by an increase in hydrodynamic diameter from approximately 42 to 59 nm after polymer immobilization. The resulting glycopolymer-functionalized AuNPs exhibited concentration-dependent lectin-mediated aggregation behavior in the presence of concanavalin A, accompanied by characteristic red shifts and broadening of the localized surface plasmon resonance (LSPR) band arising from multivalent carbohydrate–lectin interactions at the nanoparticle interface. Although the apparent association constants obtained for free alternating glycopolymers using fluorescently labeled lectin cannot be directly compared with those obtained from LSPR-based aggregation assays of AuNP-immobilized glycopolymers, the values increased from the order of 10⁵ L mol⁻¹ in solution to the order of 10⁷ L mol⁻¹ at the nanoparticle interface. This trend suggests that immobilization onto AuNPs enhances multivalent carbohydrate–lectin interactions through multivalent presentation of the glycopolymer chains at the nanoparticle interface. As a control experiment, peanut agglutinin (PNA), which does not recognize maltose residues, was added to the glycopolymer-functionalized AuNPs. No significant LSPR shift or spectral broadening was observed, indicating that nanoparticle aggregation was not induced by nonspecific lectin addition but arose from specific interactions between maltose residues and Con A. Quantitative analysis suggested that polymer chain length may influence the aggregation behavior. These results demonstrate that alternating glycopolymers provide a useful platform for constructing sequence-regulated glycointerfaces and for investigating multivalent biomolecular interactions at nanoparticle surfaces. Full article

Background: The newly synthesized palladium(II) complex [Pd(L1)Cl]Cl (where L1 = N²,N⁶-bis(5-methylhthiazol-2-yl)pyridine-2,6-dicarboxamide) has demonstrated significant in vitro antitumor activity. In this study, the effects of this complex on the immune response and its antimicrobial potential were evaluated. Methods: Splenocytes isolated from mice were treated with lipopolysaccharide (LPS)/Concanavalin A (ConA) along with the Pd(II) complex. The concentrations of IFN-γ, IL-17, IL-4, TNF-α, IL-1β, and IL-10 were measured using commercial ELISA kits. The antimicrobial effect was tested against reference strains of Gram-positive and Gram-negative bacteria, as well as yeast. The Minimal Inhibitory Concentration (MIC) was determined via the broth microdilution method, followed by the determination of Minimal Bactericidal/Fungicidal concentrations (MBC/MFC). Results: The Pd(II) complex induced an increase in the concentration of all tested cytokines compared to untreated cells. Co-treatment with Pd(II) complex and LPS significantly increased the levels of IFN-γ, IL-1β, and IL-17 compared to the LPS-only-stimulated group. Co-treatment with ConA and the Pd(II) complex resulted in a significant increase in TNF-α and IL-17 levels, whereas a significant decrease was observed in the concentrations of IL-10, IL-4, and IFN-γ compared to the ConA-only-stimulated group. The tested complex showed weak to moderate antimicrobial activity, Gram-positive bacteria showed better susceptibility to the examined complex compared to Gram-negative. Conclusions: Results of the study indicate that the Pd(II) complex exhibits a significant immunomodulatory effect on splenocytes, alongside weak to moderate antimicrobial activity. Full article

As the human population continues to grow, the demand for pork increases, and the management of infectious diseases in swine from a One Health standpoint is becoming more important than ever. To prevent antimicrobial use as much as possible, the search continues for alternative substances that can aid in mitigating oxidative stress and inflammation, which are cornerstones of infectious disease. In this study, we stimulated porcine peripheral mononuclear blood cells (pPBMCs) with either bacterial lipopolysaccharides (LPS) of different origin (Salmonella Typhimurium, Salmonella Enteritidis and E. coli), or the plant lectins concanavalin A (ConA) and phytohemagglutinin (PHA) to create an in vitro inflammatory model. Quercetin, a flavonoid with well documented positive effects, was used with the aim of decreasing oxidative stress and the production of the inflammatory cytokines IL-6 and IL-8. Oxidative stress was successfully induced in the pPBMCs by all stimulants (except for S. Enteritidis LPS), along with IL-6 production (except for E. coli LPS); IL-8 production was only induced by treatment with LPS. While quercetin had an antioxidant effect on the pPBMCs, it did not reduce IL-6 or IL-8 levels under the conditions tested and even had a pro-inflammatory effect by increasing IL-8 production when combined with LPS. To gain a deeper understanding of the immunomodulatory effects of quercetin on pPBMCs, further studies should be conducted to measure the production of additional pro- and anti-inflammatory cytokines, including TNF-α, IL-10, and IL-1β. Full article

Background/Objectives: Immune-mediated hepatitis, including autoimmune hepatitis, remains a formidable clinical challenge characterized by the rapid destruction of the liver parenchyma. While whey proteins are well-regarded for their anti-inflammatory properties, goat whey possesses a distinct bioactive profile, offering superior digestibility and reduced allergenicity compared to their bovine counterparts. This study investigated the hepatoprotective potential and underlying immunological mechanisms of lyophilized goat whey (LGW) in a Concanavalin A (ConA)-induced model of acute hepatitis. Methods: BALB/c and C57BL/6 mice were administered LGW orally (1 g/kg/day) for five consecutive days prior to a ConA challenge. Liver injury was quantified via serum transaminase levels and histopathological evaluation. The cytokine profiles and the phenotype of liver mononuclear cells (MNCs) were analyzed using ELISA and flow cytometry, respectively. Results: LGW pretreatment significantly attenuated ConA-induced hepatitis in both mouse strains, markedly reducing serum transaminase levels and preserving hepatic architecture. Mechanistically, LGW triggered a fundamental shift in the hepatic immune microenvironment by suppressing the pro-inflammatory Th1/Th17 axis (evidenced by decreased IFN-γ and IL-17) while concurrently upregulating the anti-inflammatory cytokine IL-10. Furthermore, LGW induced a tolerogenic phenotype in hepatic dendritic cells (CD11c⁺CD206⁺), which directly correlated with a significant expansion of regulatory T cells (Tregs). This strain-independent protection suggests that LGW modulates fundamental, early-stage immune signaling pathways within the liver. Conclusions: Our findings demonstrate that LGW exerts potent hepatoprotection by effectively reprogramming the hepatic immune microenvironment toward a tolerogenic state. These results position LGW as a promising, safe, and effective functional food candidate for the prevention and adjunct management of immune-mediated inflammatory liver diseases. Full article

Chronic liver damage usually results in a pathological state of excessive deposition of extracellular matrix that is known as liver fibrosis. This study was designed to examine the potential preventive effect of the pentahydroxyglucosyl flavone, gossypin (GPN), against concanavalin A (Con A)-induced liver fibrosis in BALB/c albino mice. Methods: Liver fibrosis was induced by intravenous (IV) injection of Con A (10 mg/kg) once weekly for 4 weeks. GPN (10 and 20 mg/kg) was administered orally three times weekly for 4 weeks. At the end of the experiment, serum and liver tissue were obtained and used for different biochemical, histological, histochemical and molecular assessments. GPN (10 and 20 mg/kg) considerably ameliorated liver fibrosis induced by Con A. A marked decrease in serum levels of ALT, AST and LDH was observed upon GPN treatment, confirmed by histopathological analysis by H&E. GPN markedly reduced collagen deposition as confirmed by MT staining, reduced hepatic levels of Col-1 and TGF-β as well as inhibited α-SMA immunostaining. The hepatic oxidative stress biomarker, MDA, was markedly reduced, whereas hepatic antioxidant defense, TAC, was significantly enhanced. Furthermore, GPN effectively enhanced gene and protein expression of SIRT3. GPN downregulated hepatic proinflammatory biomarkers, NF-κB and TNF-α. Additionally, GPN caused a noticeable increase in the hepatic levels and expression of PI3K and Akt. GPN effectively attenuated Con A-induced liver fibrosis via reducing liver damage and collagen deposition majorly by lessening inflammation, oxidative stress and fibrosis. GPN modulated SIRT3, NF-κB/TNF-α and PI3K/Akt pathways. Full article

Glycosylation plays a critical role in maintaining cardiac structure and function, yet its modulation during aging and hypertrophic cardiomyopathy (HCM) in feline hearts remains uncharacterized. This study provides a systematic analysis of lectin-binding patterns in feline myocardium across different age groups and disease states. Post-mortem feline hearts (n = 64), classified by age (newborn to senior) and diagnostic status (healthy vs. HCM-affected), were evaluated using tissue microarrays stained with five plant-derived lectins—Concanavalin A (ConA), Wheat Germ Agglutinin (WGA), RCA (Ricinus communis Agglutinin I), Tomato (Lycopersicon esculentum Agglutinin), and Griffonia (Bandeiraea) simplicifolia Lectin I (BS)—alongside Draq5 nuclear counterstaining. Lectin histochemistry revealed distinct, region-specific glycosylation patterns, with notable remodelling in both aged and HCM-affected hearts. These glycan alterations reflect underlying molecular and structural changes associated with cardiac aging and pathology. Although lectin histochemistry has been used to examine cardiac glycosylation in species such as mice, rats, zebrafish, and humans, comparable data for felines have been lacking, even if domestic cat represents a spontaneous model for human HCM. This study provides the first essential step in characterizing the feline cardiac glycosylation. The observed shifts in lectin-binding profiles reveal specific remodelling associated with aging and HCM in cats. These results provide a foundation for future studies assessing the utility of glycan motifs as potential post-mortem markers of disease progression in felines. Full article

Objectives: Canavalia gladiata (Jacq.) DC. (C. gladiata) has been used in traditional medicine to treat suppurative inflammatory conditions. Its antibacterial activity against oral pathogens and potential use as a non-alcoholic mouthwash have also been reported. This study aimed to elucidate the biological activity of Con A from C. gladiata, evaluate nitric oxide (NO) production induced by Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), and as-sess its potential association with periodontal inflammation. Methods: In this study, a 0.5 M NaCl extract of C. gladiata (CGE_Na) was prepared, and its protein content was quantified. The Concanavalin A equivalent (Con Aeq.) of CGE_Na was determined via a hemagglutination assay, and its effect on NO production was evaluated in RAW 264.7 macrophages stimulated with lipopolysaccharide (LPS-A.a.) derived from A. actinomycetemcomitans. LPS was extracted from six A. actinomycetemcomitans strains and used to induce inflammatory activation. Result: CGE_Na treatment significantly inhibited LPS-induced NO production at concentrations below 6.25 μg/mL without cytotoxic effects, suggesting an anti-inflammatory potential associated with lectin-like components. Conclusions: These results suggest that C. gladiata extract suppresses LPS-A.a.-mediated macrophage activation. Further studies are required to determine whether Con A specifically mediates this response and to evaluate its therapeutic relevance in the context of periodontal inflammation. Full article

Sea urchin eggs are surrounded by a network of extracellular matrix, consisting of the jelly coat (JC) and vitelline layer (VL). While the voluminous JC evokes acrosomal reaction in the approaching sperm, the tight VL ensheathing the plasma membrane of the subjacent microvilli is known to be the subcellular site where ‘sperm receptors’ reside. In this study, we have examined the roles of JC and VL at fertilization in a combinatorial approach utilizing two different pretreatments of the eggs: (i) incubation with dithiothreitol (DTT) in alkaline seawater to remove JC and VL, (ii) masking the egg extracellular matrix with a carbohydrate-binding protein concanavalin A (Con A). Surprisingly, the results showed that the DTT-denuded eggs still engulfed sperm at fertilization, even more effectively than intact eggs, as multiple sperm entered. On the other hand, Con A appeared to interfere with sperm entry in a dose-dependent manner and to delay the onset of the Ca²⁺ wave in intact eggs after the cortical Ca²⁺ release, representing sperm–egg fusion. This prolonged time lag in triggering the Ca²⁺ wave at fertilization was associated with compromised dynamics of the subplasmalemmal actin filaments in Con A-pretreated eggs. By using Alexa Fluor 633 Con A and BPA-C8-Cy3, respectively, we also report unprecedented fluorescent labeling of the egg JC and the spontaneous ‘acrosomal protrusion’ on the head of Paracentrotus lividus sperm diluted in natural seawater. Combined with electron microscopy observations of intact and denuded eggs, our results suggest that the glycoconjugate on the egg surface contributes to the fertilization signal transduction, affecting the Ca²⁺ wave via actin cytoskeletal changes and sperm entry. Full article

This presented study depicts the synthesis of three novel carbazole–thiazole conjugates, thoroughly investigating their spectroscopic properties as well as evaluating their biological activity as tyrosinase inhibitors. Additionally, we investigated the possibility of using Concanavalin A (ConA) complexes with dyes from a theoretical point of view, developing a promising protein-based strategy of delivery of dyes to the target cells. The tyrosinase inhibition assay showed that compounds K1 and K3 demonstrated higher activity than the kojic acid with IC₅₀ values of 46 and 59 mM, respectively. Among the tested compounds, carbazole K3 exhibits the most pronounced nonlinear optical response due to its high electronic flexibility, strong solvatochromism, large excited-state dipole moments, and efficient intramolecular charge transfer. Additionally, all investigated carbazoles demonstrate high ability to form stable supramolecular complexes with ConA, which was confirmed using molecular docking studies. It was found experimentally and theoretically that the compound K3 has the best biophysical parameters, making it a promising candidate for potential diagnostic applications. Full article

Autoimmune hepatitis (AIH) is linked to an increased risk of hepatocellular carcinoma (HCC). However, the precise connection between the two remains unclear. GPR81, a G-protein-coupled receptor located on the membranes of various cell types, plays a role in numerous physiological processes. We established an AIH animal model and activated GPR81 using the agonist 3,5-dihydroxybenzoic acid (3,5-DHBA). Additionally, the effect of GPR81 inhibition on tumor and immune cell dynamics was examined using the HepG2, Hep3B, and Hepa1-6 cell lines with the antagonist 3-hydroxybutyric acid (3-OBA). Our results demonstrated that 3,5-DHBA treatment reduced T cell and pro-inflammatory cytokine secretion, while MDSC secretion increased, inhibiting Concanavalin A (Con A)-induced AIH. The inhibition of GPR81 by 3-OBA suppressed HCC cell proliferation and invasion, reduced tumor volume and weight, and downregulated PD-L1 expression. Furthermore, CTL and DC activity in the spleen and tumors increased, while MDSC activity decreased. This study confirms that GPR81 plays an important role in both inflammation and tumorigenesis, suggesting that GPR81 may serve as a bridge in the transformation of inflammation into cancer. Modulating GPR81 activity may provide a novel therapeutic strategy for hepatitis and cancer. Full article

Due to rising antibiotic resistance, it is necessary to develop alternative ways to combat pathogenic bacteria. One alternative is photodynamic antibacterial chemotherapy (PACT). This work presents the conjugation of the photosensitizer Rose Bengal (RB) to lectins to improve its efficacy against Gram-positive and Gram-negative bacteria. Two lectins, concanavalin A (ConA) and wheat germ agglutinin (WGA), were covalently linked to RB. Spectroscopic and chromatographic data confirmed successful conjugation. Microscopic examination demonstrated that both lectins agglutinate cells of Gram-positive S. aureus, including clinical multidrug-resistant MRSA strains, and Gram-negative E. coli, P. aeruginosa, and S. paratyphi B, although ConA showed a more pronounced reaction. Photodynamic assays showed that ConA-RB achieved complete eradication of S. aureus at significantly lower concentrations and light doses than free RB or WGA-RB. ConA-RB also exhibited higher efficacy against Gram-negative bacteria compared to free RB at lower concentrations and shorter illumination periods. WGA-RB was less effective, showing preferential activity against S. aureus. Our findings suggest that lectin–RB conjugates offer a promising approach for selective antibacterial treatment under illumination. Full article

Background: Ten new sesquiterpenes, including eight eremophilane-type sesquiterpenes (1–8) and two compounds (9–10) with a cyclopentane ring, representing an undescribed subtype of sesquiterpene, along with a new abietane-type diterpenoid (11), were isolated and identified from a deep-sea-derived fungus: Eutypella sp. Methods: Their structures were elucidated on the basis of various spectroscopic analyses, mainly including nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectrometry (HRESIMS) data, ¹³C NMR calculations with DP4+ probability analyses, electronic circular dichroism (ECD) calculations, and single-crystal X-ray diffraction experiments. Results: Furthermore, compound 11 exhibited potent immunosuppressive activity with IC₅₀ values of 8.99 ± 1.08 μM in a lipopolysaccharide (LPS) model and 5.39 ± 0.20 μM in a concanavalin A (ConA) model. Full article

The accurate detection and quantification of pathogenic bacteria is crucial for ensuring public health. In this work, we propose a sensitive and selective sandwich electrochemical sensor for detecting Escherichia coli O157:H7 (E. coli O157:H7). The sensor employs a dual-recognition strategy that combines a bacteria-imprinted polymer (BIP) and concanavalin A (ConA). The BIP is formed in situ on the electrode surface as the capture probe, while gold nanoparticles co-functionalized with ConA and the electroactive molecule 6-(ferrocenyl)hexanethiol (Au@Fc-ConA) serve as the signaling probe. When E. coli O157:H7 is present, the bacteria are selectively captured by the BIP. The captured bacteria interact with Au@Fc-ConA through ConA’s sugar-binding properties, triggering Fc oxidation and generating a current proportional to the bacterial concentration. The sensor exhibits a linear detection range of 10¹–10⁵ CFU mL⁻¹ and a low detection limit of 10 CFU mL⁻¹. Additionally, it demonstrates high sensitivity in complex milk samples, detecting E. coli O157:H7 at concentrations as low as 10 CFU mL⁻¹, with recoveries ranging from 94.16% to 110.6%. Even in the presence of a 100-fold higher concentration of E. coli O6, the sensor effectively distinguishes E. coli O157:H7 from it. Moreover, it exhibits high reproducibility with a relative standard deviation of 2%. This study proposes a unique dual recognition strategy that combines simplicity and high performance. This method enables the selective detection of E. coli O157:H7 in real samples, providing a promising tool for food safety monitoring. Full article

Gagam-palmultang (PMT), a traditional Korean herbal formula, has been used to treat various conditions; however, its immunomodulatory potential remains unclear. Our objective was to assess the immunomodulatory effects of PMT in an immunosuppression mouse model. In vitro, we assessed interleukin (IL)-10 production in concanavalin A (Con A)-stimulated mouse splenocytes using real-time polymerase chain reaction and enzyme-linked immunosorbent assays. In vivo, C57BL/6 mice were intraperitoneally administered cyclophosphamide (CPA) to induce immunosuppression, followed by the oral administration of PMT (100 or 200 mg/kg) once daily for 14 days to evaluate its effects on T lymphocyte activation and immune function restoration. Immune function was evaluated via flow cytometric analysis of CD4⁺ and CD8⁺ T cells, thymus index measurements, thymic histopathology, and hematological analysis of white blood cell, monocyte, lymphocyte, neutrophil, and eosinophil counts. PMT significantly increased IL-10 production in Con A-stimulated splenocytes. In immunosuppressed mice, PMT restored the thymus index, improved thymic histopathology, and enhanced hematological parameters. Flow cytometry showed a significant increase in CD3e⁺CD4⁺ and CD3e⁺CD8⁺ T lymphocytes, and histological evaluation revealed increased CD3⁺ lymphocytes in the thymus. These findings suggest that PMT enhances T lymphocyte activation and restores immune homeostasis under immunosuppressive conditions, demonstrating its potential as a herbal immunomodulatory agent. Full article

Interferon-γ (IFN-γ), a member of the Type II IFN family, is a crucial cytokine in the immune system and serves as an important indicator of immune response. Intracellular cytokine staining (ICS) is a technique used to analyze the production of cytokines within individual cells, and it has a wide range of applications in the fields of immunological monitoring, vaccine trials, and the study of infectious diseases. This study aimed to prepare monoclonal antibodies against duck IFN-γ protein and to establish an ICS protocol for detecting the duck IFN-γ protein. The duIFN-γ-His or duIFN-γ-Fc gene was cloned into the pEE12.4 expression vector and expressed as a recombinant protein of size 20.2 KDa or 54.9 KDa in 293F cells. The purified recombinant proteins were inoculated into BALB/c mice to generate splenic lymphocytes capable of secreting anti-duIFN-γ antibodies, and hybridoma cells were obtained after fusion with SP2/0 cells. A new hybridoma cell line named 24H4, which stably secreted IgG3 κ subtype antibody against duck IFN-γ, was established. This monoclonal antibody (mAb) was identified by Western blot to recognize duck IFN-γ antibodies, and the indirect ELISA results showed that its ability to recognize IFN-γ protein reached 0.001 μg/mL. The established ICS method was used to stain PBMCs after Concanavalin A (ConA) stimulation, and duck IFN-γ protein was successfully detected by flow cytometry, indicating that the ICS method was successful. In this study, we provide a crucial tool for subsequent research on duck cellular immune responses by using the monoclonal antibody 24H4. Full article