Search Results (665)

Kynurenic acid (KYNA), a tryptophan metabolite, possesses immunomodulatory properties, although the molecular mechanism of this action has not yet been resolved. In the present study, the effects of KYNA on the secretion of selected cytokines and chemokines by macrophages derived from the human THP-1 cell line are investigated. Furthermore, the involvement of the aryl hydrocarbon receptor (AhR) and the G protein-coupled receptor 35 (GPR35) in mediating the effects of KYNA was examined. In lipopolysaccharide (LPS)-stimulated THP-1-derived macrophages, KYNA significantly reduced IL-6 and CCL-2, but increased IL-10 and M-CSF levels. AhR antagonist CH-223191 reduced the KYNA influence on IL-6, CCL-2, and M-CSF production, while the GPR35 antagonist, ML-145, blocked KYNA-induced IL-10 production. Furthermore, it was shown that THP-1 derived macrophages were capable of synthesizing and releasing KYNA and that its production was increased in the presence of LPS. These findings suggest that THP-1-derived macrophages are a source of KYNA and that KYNA modulates inflammatory responses predominantly through AhR and GPR35 receptors. Our study provides further evidence for the involvement of macrophages in immunomodulatory processes that are dependent on AhR and GPR35 receptors, as well as the potential role of KYNA in these phenomena. Full article

Human coronaviruses are a group of viruses that continue to threaten human health. In this study, we investigated the antiviral activity of 4-hydroxychalcone (4HCH), a chalcone derivative, against human coronavirus HCoV-OC43. We found that 4HCH significantly inhibited the cytopathic effect, reduced viral protein and RNA levels in infected cells, and increased the survival rate of HCoV-OC43-infected suckling mice. Mechanistically, 4HCH targets the early stages of viral infection by binding to the epidermal growth factor receptor (EGFR) and inhibiting the EGFR/AKT/ERK1/2 signaling pathway, thereby suppressing viral replication. Additionally, 4HCH significantly reduced the production of pro-inflammatory cytokines and chemokines in both HCoV-OC43-infected RD cells and a suckling mouse model. Our findings demonstrate that 4HCH exhibits potent antiviral activity both in vitro and in vivo, suggesting its potential as a therapeutic agent against human coronaviruses. This study highlights EGFR as a promising host target for antiviral drug development and positions 4HCH as a candidate for further investigation in the treatment of coronavirus infections. Full article

Estrogen-related receptor γ (ERRγ) has been reported to regulate various inflammation-related diseases. Herein, we attempted to evaluate the effects of DN200434 as a modulator for ERRγ in mice with atopic dermatitis (AD). Levels of mRNA and protein expression for ERRγ were evaluated in normal and DNCB-induced AD-diagnosed skin. The effects of DN200434 on the chemokines, inflammatory cytokines, and AKT/MAPK/NFκB pathway signaling were investigated in TNF-α/IFN-γ-treated HaCaT cells. DNCB-induced AD mice received DN200434 intraperitoneally for 10 days. Epidermal thickness at the dorsal aspect of the inflamed skin, spleen index, serum IgE levels, and proinflammatory cytokine levels in the skin lesions were measured. Histopathological evaluations, including assessments of epidermal hyperplasia, dermal inflammation, hyperkeratosis, folliculitis, and mast cell counts, were performed to confirm diagnostic features. Significant elevations in ERRγ expression at the RNA and protein levels were observed in DNCB-induced AD lesions. DN200434 suppressed chemokine and inflammatory cytokine expression and inhibited the elevated phosphorylation levels of AKT, ERK, p38, and NFκB in TNF-α/IFN-γ-treated HaCaT cells. Treatment with DN200434 alleviated DNCB-induced AD symptoms. The histopathological score and levels of infiltrated mast cells were also markedly lower in DN200434-treated AD mice than in vehicle-treated AD mice. Consistently, DN200434 reduced the serum IgE level and mRNA expression of TNFα and IL-6 in AD-diagnosed lesions. Collectively, our findings indicated the feasibility of ERRγ as a therapeutic target for the regulation of AD and that DN200434 can be a useful therapeutic agent in treating AD. Full article

IgG antibodies, signaling via the inhibitory receptor, FcγRIIb, are potent inhibitors of IgE-mediated mast cell activation. We have previously reported that in addition to blocking mast cell degranulation, inhibitory IgG signals shut down a proinflammatory transcriptional program in which mast cells produce cytokines and chemokines known to drive type 2 tissue inflammation. To determine whether such effects of allergen-specific IgG can modulate allergic inflammation in vivo, we examined the airways of mice sensitized to ovalbumin (OVA) by intraperitoneal injection and then challenged with intranasal OVA. Pretreatment with allergen-specific IgG significantly reduced the recruitment of inflammatory cells, including macrophages and eosinophils, into the lungs of OVA-sensitized mice. The bronchoalveolar lavage fluid of OVA-challenged mice contained elevated levels of chemokine ligands (CCL2 and CCL24) and interleukin-5, a response that was markedly blunted in animals receiving allergen-specific IgG. IgG-treated animals exhibited attenuated allergen-induced production of IgE, IL-4, and IL-13, along with impaired OVA-induced goblet cell hyperplasia and Muc5ac expression and suppressed airway hyperresponsiveness, consistent with a shift away from a Th2 response. Using mice with a lineage-specific deletion of FcγRIIb, we demonstrated that each of these protective effects of IgG was dependent upon the expression of this receptor on mast cells. Overall, our findings establish that allergen-specific IgG can reduce allergen-driven airway inflammation and airway hyperresponsiveness and point to a mechanistic basis for the therapeutic benefit of aeroallergen-specific IgG therapy. Full article

This review summarizes the available evidence on hyaluronic acid’s (HA’s) role in immune response. HA is one of many components in the extracellular matrix that transmits signals from the extracellular microenvironment to cellular effector systems in immune cells. The final effect of these interactions depends on the type of cells and receptors used and the size of HA particles. HA’s activation of intracellular signaling pathways leads to an immune response involving the release of pro- or anti-inflammatory cytokines and chemokines. These play a crucial role in defense mechanisms, such as protecting against pathogens and tissue healing after injuries. HA, as a signaling particle, is also involved in the intensification of the cytokine storm during COVID-19. Multifold increases in HA content in the lungs and the strength of its impact on the immune system define an “HA storm”. The molecular mechanisms involved in inflammation and initiation, including the promotion of cancer, also begin in the microenvironment, and hyaluronic acid is a key element. In this paper, we focus on intra- and intercellular signaling pathways using HA participation rather than injection preparation based on HA use for esthetic treatment. Full article

Kazakh mares have drawn significant attention for their outstanding lactation traits. Lactation, a complex physiological activity, is modulated by multiple factors. This study utilized high-throughput sequencing to conduct whole-transcriptome sequencing analysis on the mammary gland tissue of eight Kazakh mares, of which four were pregnant and four were non-pregnant, to systematically reveal the molecular regulatory mechanisms. The results showed differential expression in 2136 mRNAs, 180 lncRNAs, 104 miRNAs, and 1162 circRNAs. Gene ontology functional annotation indicates that these differentially expressed genes are involved in multiple key biological processes, such as the cellular process (BP), metabolic process, and biological regulation. Kyoto Encyclopedia of Genes and Genomes analysis suggests that the differentially expressed genes are significantly enriched in essential pathways such as cytokine–cytokine receptor interaction, the chemokine signaling pathway, and the PI3K-Akt signaling pathway. Additionally, this study constructed a competing endogenous RNA (ceRNA) regulatory network based on the differentially expressed genes (|log₂FC| > 1, FDR < 0.05), offering a novel perspective for revealing the functional regulation of the mammary gland. This study compared genomic differences in mammary gland tissue of pregnant and non-pregnant Kazakh mares and identified candidate genes that are closely related to lactation regulation. It found that various genes, such as PIK3CG, IL7R, and SOD2, play central regulatory roles in activating mammary gland functions. These findings provide theoretical support for explaining the molecular mechanisms underlying the mammary gland development of Kazakh mares. Full article

Compelling evidence has demonstrated a bidirectional relationship between Sjögren’s syndrome (SS) and periodontitis (PD). Nevertheless, the underlying mechanisms driving their co-occurrence remain unclear, highlighting the need for finding the hub gene. This study sought to examine the common genes and any connections between SS and PD. Differently expressed genes (DEGs) were analyzed by means of gene set enrichment analysis (GSEA), weighted gene co-expression network analysis (WGCNA), and least absolute shrinkage and selection operator (LASSO) methods. The test and validation sets were used to depict the receiver operating characteristic (ROC) curves. The immune cell infiltration was performed via the cell-type identification by estimating relative subsets of RNA transcripts (CIBERSORT) methodology. The relationships between immune infiltrating cells and the common gene were examined. Ninety-five common genes with similar expression trends were obtained after DEGs analysis, which were enriched in cytokine—cytokine receptor interaction, chemokine signaling pathway, proteasome, intestinal immune network for IgA production, and cytosolic DNA sensing pathway. Thirty-nine common genes were obtained after WGCNA. Sixteen shared genes of DEGs analysis and WGCNA were incorporated into the LASSO model to obtain the unique shared gene, C-C motif chemokine receptor 1 (CCR1), which overexpressed and owned predictable ROC curves in test and validation sets. The examination of immune cell infiltration underscored its crucial roles in the disturbance of immune homeostasis and the emergence of pathogenic circumstances with the simultaneous occurrence of SS and PD. CCR1 overexpresses and serves as a critical pathogenic hub linking SS and PD, which may play a role through immune cell infiltration. Full article

Fungi are ubiquitous organisms that are capable of transient or persistent colonization in humans. Their polymorphic nature and complex host–mycobiome interactions remain incompletely understood. Emerging evidence highlights the role of resident fungi in modulating immune responses and adapting to host changes, which can trigger a shift from commensalism to parasitism, particularly in immunocompromised individuals. This study evaluated the effects of two major β-glucans—zymosan and curdlan—on the expression of pattern recognition receptors (Dectin1, Dectin2, TLR2, TLR4) in human peripheral blood mononuclear cells (PBMCs). It also examined their impact on reactive oxygen species (ROS) production, cytokine/chemokine gene expression, and antioxidant enzyme expression. Both β-glucans significantly increased the mRNA levels of all tested receptors and enhanced ROS generation. Curdlan downregulated key antioxidant enzymes (SOD1, CAT, GPX1), while zymosan markedly upregulated SOD1. These findings demonstrate that the β-glucans zymosan and curdlan have a substantial influence on PBMC reactivity and oxidative stress responses. Further studies are needed to deepen our understanding of host–fungal interactions and their implications in health and disease. Full article

Chemokines are low-molecular-weight peptides classified as cytokines with chemotactic properties. The chemokine CXCL13 and its receptor CXCR5 play a significant role in cardiac remodeling, and their expression is markedly increased in experimental models of heart failure. Increased CXCL13 activity is associated with the expression of fibromodulin, a proteoglycan that binds and cross-links collagen fibers. The stressed heart undergoes intensive remodeling, including fibrosis. In our experiment, we investigated the effect of the most commonly used triple immunosuppressive regimens on the expression of the CXCR5 receptor, the chemokine CXCL13, and fibromodulin in rat heart tissue. For this purpose, we used Western blot analysis and ELISA. The study was started on 36 rats divided into 6 groups, which received drugs for a period of 6 months. Our results suggest that the chronic use of calcineurin inhibitors in combination with mycophenolate mofetil is a significant stress factor for the heart, leading to abnormal remodeling of the extracellular matrix. The use of rapamycin may alleviate the negative effects of immunosuppressive therapy on the heart. Our results are consistent with the results of our previous studies and provide a basis for further work aimed at understanding the pathophysiology of the development of changes in the heart with individual immunosuppressive regimens. Full article

Kawasaki disease (KD) is a systematic inflammatory condition that results in vasculitis and possible progression to the development of coronary artery lesions if left untreated. Disease pathogenesis is not fully understood, and diagnosis is based on clinical symptoms, with limited reliability considering that KD progression is time sensitive. This is further complicated by the shared clinical characteristics with other febrile diseases. Early diagnosis and prompt treatment start are associated with good prognosis in most patients. However, up to 20% of patients are resistant to available therapeutic agents and would benefit from alternative regimens. Therefore, identification of biomarkers that can provide insights on disease pathogenesis are necessary to enable early diagnosis and initiation of treatment, as well as to predict treatment responses. To this end, immunophenotyping, most commonly by flow cytometry, has been crucial in identifying central factors in KD pathogenesis. The available literature on such factors is vast and may include contradictory findings. Therefore, we aimed to summarize the available literature of the last decade on the immunophenotype of KD, focusing on biomarkers associated with disease pathogenesis and those associated with treatment response. Our review highlights the role of cells of both the innate and adaptive immune system in disease pathogenesis, as well as the role of various secreted and cell surface proteins, including inflammatory cytokines, chemokines, complement receptors, and chemoattractants both in KD pathogenesis and in treatment response. Full article

The spore-forming probiotic Bacillus coagulans JBI-YZ6.3 interacts with the gut epithelium via its secreted metabolites as well as its cell walls, engaging pattern-recognition receptors on the epithelium. We evaluated its effects on human T84 gut epithelial cells using in vitro co-cultures, comparing metabolically active germinated spores to the isolated metabolite fraction and cell wall fraction under unstressed versus inflamed conditions. Germinated spores affected epithelial communication via chemokines interleukin-8, interferon gamma-induced protein-10, and macrophage inflammatory protein-1 alpha and beta after 2 and 24 h of co-culture. Non-linear dose responses confirmed that bacterial density affected the epigenetic state of the epithelial cells. In contrast, the cell wall fraction increased cytokine and chemokine levels under both normal and inflamed conditions, demonstrating that the intact bacterium had anti-inflammatory properties, regulating pro-inflammatory signals from its cell walls. During recovery from mechanical wounding, germinated spores accelerated healing, both in the absence and presence of LPS-induced inflammation; both the metabolite and cell wall fractions contributed to this effect. The release of zonulin, a regulator of tight junction integrity, was reduced by germinated spores after 2 h. These findings suggest that B. coagulans JBI-YZ6.3 modulates epithelial chemokine signaling, supports barrier integrity, and enhances epithelial resilience, highlighting its potential as an efficacious multi-faceted probiotic for gut health. Full article

Toll-like receptors (TLRs) comprise an evolutionarily conserved family of pattern recognition receptors that detect microbial-associated molecular patterns and endogenous danger signals to orchestrate innate immune responses. While traditionally positioned at the frontline of host defense, accumulating evidence suggests that TLRs are at the nexus of immuno-metabolic regulation and central nervous system (CNS) homeostasis. They regulate a wide range of immune and non-immune functions, such as cytokine and chemokine signaling, and play key roles in modulating synaptic plasticity, neurogenesis, and neuronal survival. However, alterations in TLR signaling can drive a sustained pro-inflammatory state, mitochondrial dysfunction, and oxidative stress, which are highly associated with the disruption of emotional and cognitive functions and the pathogenesis of psychiatric disorders. In this review, we integrate findings from molecular to organismal levels to illustrate the diverse roles of TLRs in regulating emotion, cognition, metabolic balance, and gut–brain interactions. We also explore emerging molecular targets with the potential to guide the development of more effective therapeutic interventions. Full article

Background: SARS-CoV-2 immunity is understudied in cancer patients. Here, we monitored natural/vaccine-induced SARS-CoV-2 immunity in patients with head and neck cancer (HNC) stratified as vaccinated (mRNA/adenovirus-based vaccines), convalescent, and hybrid immunity. Methods: Plasma/PBMC samples were collected from 49 patients with HNC and 14 non-oncologic controls recruited between August 2021 and March 2022. Longitudinal follow-up was performed on 25 HNC patients. Plasma antibodies (Abs) against Spike (S1/S2), receptor-binding domain (RBD), and nucleocapsid (NC) of IgG/IgA isotypes and 25 cytokines/chemokines were quantified using MILLIPLEX^® technology. The frequency, phenotype, and isotype of circulating SARS-CoV-2-specific B-cells were studied by flow cytometry using RBD tetramers (Tet⁺⁺). The proliferation of B-cells and CD4+ and CD8+ T-cells in response to Spike/NC peptides was monitored by a carboxyfluorescein succinimidyl ester (CFSE) assay. Results: Plasma SARS-CoV-2 S1/S2/RBD IgG/IgA Abs were detected in all HNC participants at enrollment median time since immunization (TSI) 117 days at levels similar to controls and were significantly higher in convalescent/hybrid versus vaccinated. NC IgG/IgA Abs were only detected after infection. The frequency of Tet++ B-cells, enriched in the CD27+ memory phenotype and IgG/IgA isotype, positively correlated with plasma levels of RBD IgG/IgA Abs and Spike-specific CD4+ T-cell proliferation, regardless of the immunization status and TSI. Spike/NC-specific B-cell proliferation reached the highest levels in convalescent HNC and was positively correlated with NC IgG Abs, but not with the frequency of Tet++ B-cells. Finally, Tet++ B-cell frequencies remained stable between the two subsequent visits (median TSI: 117 versus 341 days), indicating their ability to persist for a relatively long time. Conclusions: This study monitored SARS-CoV-2 humoral/cellular immunity in an HNC cohort relative to non-oncologic participants and demonstrates that SARS-CoV-2-specific B-cells persist beyond 11 months post-immunization. These findings have implications for the management of HNC in the context of SARS-CoV-2 infection and other viral infections. Full article

Canine chronic enteropathy (CE) is a gastrointestinal disorder characterized by persistent or recurrent digestive symptoms lasting more than three weeks. It shares similarities with human inflammatory bowel disease but its immunopathogenesis remains poorly characterized in dogs. The aim of this study was to characterize the local and systemic immune profile of dogs with CE by assessing cytokine and chemokine expression in serum and intestinal tissue, as well as the mRNA expression of immune-related receptors such as integrins, chemokine receptors, and cytokines. Duodenal biopsies and blood samples were collected from five dogs diagnosed with a CE and five healthy controls. Serum concentrations of cytokines and chemokines were determined by multiplex ELISA, and mRNA expression in the intestinal mucosa was analyzed by quantitative PCR. Dogs with a CE showed increased expression of pro-inflammatory cytokines, including TNF-α and IFN-γ, and increased concentrations of chemokines such as CXCL10 and CCL2 in both serum and tissue samples. Increased mRNA expression of the chemokine receptor CCR9 and the adhesion molecule MAdCAM-1 were also observed in intestinal samples. These findings provide new insights into the immune response involved in CE and may aid the development of future diagnostic biomarkers and targeted therapies for canine chronic enteropathies. Full article

Background/Objectives: Neurofibromatosis type 1 (NF1) is a prevalent inherited disorder, with approximately 50% of affected individuals developing plexiform neurofibromas (PNFs), which can progress to highly aggressive malignant peripheral nerve sheath tumors (MPNSTs). While selumetinib is FDA-approved for PNFs, its efficacy in MPNSTs is limited and associated with dose-limiting toxicities. NF1 deficiency drives tumorigenesis and alters immune dynamics via RAS hyperactivation. Given the substantial macrophage infiltration in NF1 lesions and its association with disease progression, we hypothesized that targeting tumor-promoting immune cells with the retinoid X receptor (RXR) agonist MSU-42011 could be an alternative therapeutic strategy, as it has shown promise in KRAS-driven cancers by decreasing pERK levels and reducing tumor-promoting immune cells. Methods: We examined the effects of MSU-42011 and selumetinib, alone and in combination, on NF1-deficient cells and in a syngeneic MPNST model. Results: In vivo, the combination of MSU-42011 and selumetinib significantly reduced tumor growth, pERK levels, and tumor-promoting macrophages and increased activated CD8⁺ T cells in syngeneic MPNST models. In NF1-deficient cells, MSU-42011 or selumetinib reduced pERK levels, with combination treatment achieving greater reductions. Conditioned media (CM) from NF1-deficient cells increased the protein and mRNA levels of several cytokines and chemokines in human THP1 cells and bone marrow-derived macrophages (BMDMs). MSU-42011 and selumetinib, alone or in combination, partially reversed this induction. Conclusions: These findings suggest RXR agonists may have therapeutic potential against NF1, and their combination with MEK inhibitors could represent a promising strategy for NF1-associated tumors. Further studies are needed to validate these results and assess their translational relevance. Full article