Journal of Innate Immunity最新文献

Introduction: Synovial natural killer (NK) cells contribute to inflammation in arthritis by secreting cytokines and modulating synovial fibroblast activation. The aim of this study was to describe systemic versus local inflammatory changes of NK cell subsets as well as their physical cell-cell interactions in arthritis patients.

Methods: Spectral flow cytometry was used to compare paired peripheral blood (PB) and synovial fluid (SF) immune cells from patients with active inflammatory arthritis and healthy controls. Physical cell-cell interactions within tissues were studied by applying a recently developed cellular interaction mapping framework.

Results: Our paired approach revealed significant local enrichment of immature and activated NK cells in SF, characterized by elevated markers of early differentiation, immune-checkpoint regulation, and tissue-residency, highlighting tightly controlled immune activation at inflamed sites. Single-cell analysis confirmed heterogeneity within SF-NK cells, suggesting multiple co-existing activation states and developmental stages. PB-NK cells from patients differed profoundly compared to healthy controls, showing less immature NK cell subsets and an enrichment of mature, pro-inflammatory subsets indicative of systemic immune activation. Cellular interaction mapping revealed mainly NK/neutrophil interactions of patients' NK cells, while interactions with B-cells, T-cells, or monocytes were negligible. T-cells also displayed profound local and systemic alterations. Cellular interaction mapping revealed that next to NK/neutrophil interactions, interactions between B-cells with monocytes and T-cells with neutrophils characterize joint inflammation.

Conclusion: This paired high-dimensional analysis revealed systemic and local alterations in NK cell subsets shaped by co-existing developmental stages and immune regulatory mechanisms. Cellular interaction mapping indicated that neutrophils are a main interaction-partner of NK cells in inflamed joints.

Introduction: The complement system's alternative pathway relies on factor H (FH) for immune homeostasis. Next to FH, a group of highly similar proteins was described known as the FH-related (FHR) proteins. The FH protein family includes FH, factor H-like protein 1, and five FHR proteins (FHR-1 to -5). The exact function of the FHRs is still unknown, necessitating further research. However, the lack of highly specific assays has hindered studying their role in health and disease. This study aimed to develop novel ELISAs for reliably and specifically quantifying levels of the FHRs in human blood.

Methods: Novel FHR-specific antibodies were generated. Positive hybridoma clones were taken to monoclonality, verified for target specificity via ELISA and Western blot, and antibody pairs were selected for further ELISA development. During development, ELISAs were characterized and validated for specificity, stability, accuracy, and reproducibility, among others.

Results: Monoclonal antibodies specific for FHR-2, -3, -4, or -5 were generated. Using these antibodies, four ELISAs were developed capable of quantifying FHR levels in an accurate and robust manner. Each assay showed high target specificity, good analyte recovery and strong reproducibility between replicates, test runs, and test laboratories.

Conclusions: These assays enable specific and accurate quantification of FHR-2, -3, -4, and -5 in human blood. They facilitate large-scale screening of patient cohorts in a standardized manner and contribute to understanding the role of the FHRs in health and disease.

Introduction: This study investigated the role of FCGR3A in pediatric inflammatory bowel disease (IBD) through integrated transcriptomic analysis and experimental validation, aiming to provide new mechanistic insights and therapeutic strategies.

Methods: Transcriptomic datasets of pediatric IBD were obtained from the Gene Expression Omnibus database, and differentially expressed genes (DEGs) were identified. Weighted gene co-expression network analysis (WGCNA) was applied to screen disease-related modules, followed by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses of overlapping DEGs. Hub genes were determined using protein-protein interaction networks, least absolute shrinkage and selection operator regression, and random forest algorithms. Their expression was verified by meta-analysis across multiple datasets, and diagnostic value was assessed using receiver operating characteristic (ROC) curves. The relationship between hub genes and immune infiltration was further explored. Functional assays included lipopolysaccharide (LPS)-stimulated intestinal epithelial and THP-1 macrophage models, as well as a dextran sulfate sodium (DSS)-induced murine colitis model.

Results: WGCNA revealed 370 module genes associated with pediatric IBD, enriched in inflammatory pathways. Seven candidate genes were identified, among which FCGR3A showed a strong association with pediatric IBD. Immune infiltration analysis demonstrated that FCGR3A expression correlated with M1 macrophage enrichment. In vitro, FCGR3A was upregulated in LPS-induced epithelial cells, and its knockdown inhibited M1 macrophage polarization. In vivo, FCGR3A was highly expressed in DSS-induced murine colitis, promoting M1 polarization and disease progression. ROC analysis indicated strong predictive value (AUC = 0.968).

Conclusion: FCGR3A may serve as a pivotal regulator in pediatric IBD by driving M1 macrophage polarization, representing a promising biomarker and potential therapeutic target.

Introduction: Qilian Jiechang Ning (QJN), a traditional Chinese herbal formula, has demonstrated potential therapeutic effects in the treatment of ulcerative colitis (UC). This study aims to investigate the mechanism of QJN in the outer membrane vesicles (OMVs) of Segatella copri (S. copri)-induced colon epithelial cells and UC mice.

Methods: Transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA) were utilized to assess the morphology and size of OMVs. Inflammation markers and tight junction protein levels in HCoEpiCs induced by OMVs were monitored using ELISA and western blot. QJN was administered to intervene in HCoEpiCs treated with S. copri OMVs. Additionally, trinitrobenzene sulfonic acid (TNBS)-induced mouse models were conducted to evaluate the therapeutic effects of QJN on UC.

Results: S. copri OMVs treated with QJN demonstrated a significant reduction in particle size, protein concentration, and LPS content. In HCoEpiCs, QJN effectively decreased the expression of inflammation-inducing cytokines (IL-1β, IL-18, IL-6, TNF-α) and proinflammatory proteins (GSDMD-N, NLRP3, ASC, cleaved Caspase-1, cleaved Caspase-4) triggered by S. copri OMVs, while enhancing the expression of tight junction proteins (ZO-1 and Occludin). In the UC mouse models, QJN significantly reduced the Disease Activity Index (DAI), improved colon length, lowered LPS levels, ameliorated colonic tissue damage, and inhibited Caspase-1- and Caspase-11-dependent inflammatory responses.

Conclusion: QJN can alleviate S. copri-OMV-induced inflammatory response in colonic epithelial cells and reduce symptoms of UC in mouse models by modulating the Caspase-1 and Caspase-11 pathways.

Introduction: Toll-like receptor 9 (TLR9) is primarily expressed in human dendritic and B cells and recognizes double-stranded DNA motifs from pathogens to initiate an inflammatory response. Recent studies have revealed TLR9s' involvement beyond its conventional role in the immune response, notably during the tumorigenesis of various cancers such as head and neck, cervical, and ovarian cancers.

Methods: In this study patient biopsies of breast cancer tumors and normal breast epithelium were analyzed by immunohistochemistry to examine TLR9 expression. The study also investigated downregulation in transformed breast cancer cell lines compared to untransformed breast epithelial cells by analyzing gene or protein expression, including TLR9, IL-6, CCL2, CXCL1, and GM-CSF. MDA-MB-361 cells were engineered to express exogenous TLR9, and the effects on colony growth and senescence were assessed using colony formation assays, senescence staining, cytokine analysis, and flow cytometry.

Results: TLR9 levels in breast cancer tumors were significantly reduced compared to normal breast tissue epithelium. This downregulation was also observed in several transformed breast cancer cell lines compared to untransformed breast epithelial cell lines. Furthermore, MDA-MB-361 breast cancer cells expressing exogenous TLR9 exhibited reduced colony growth and an increase in the senescence marker IL-6, pro-inflammatory cytokine CCL2, CXCL1 chemokine; and growth factor GM-CSF.

Conclusion: These findings support TLR9's regulatory role in mitigating breast cancer and highlight its critical connection between the innate immunity and tumor cell growth.

Introduction: SARS-CoV-2's continued global health impact underscores the importance of ongoing pathogenesis research. Insights into the host's first line of defense against severe COVID-19 identify actionable biomarkers, informing disease management or therapeutics. Yet, the innate immune response, including cytokines, chemokines, adenosine deaminases (ADAs) and Toll-like receptors (TLRs), relevant to COVID-19 remain incompletely characterized.

Methods: Peripheral blood was longitudinally collected between May 2020 and March 2021 from COVID-19 hospitalized adults (N = 79) and healthy controls (HCs) (N = 14; not tested, assumed COVID-negative, no viral exposure or symptoms). Heparinized blood was fractionated for plasma cryopreservation and in vitro whole blood TLR-stimulation employing TLR-3, -4, and -7/8 agonists. Post-stimulation culture supernatants were analyzed using multiplex and enzymatic assays.

Results: Upon hospitalization, plasma concentrations of IFNγ, IL-6, CXCL10, and ADAs were significantly upregulated compared to convalescent time points and HCs. Participants with fatal COVID-19 exhibited higher IL-27, CXCL10, and ADAs concentrations upon admission. Plasma cytokines, chemokines, and ADAs were positively correlated and associated with distinct temporal patterns. TLR-stimulated cell cultures from patients produced reduced IFNα2, IFNγ, IL-12p40, and IL-12p70 compared to HCs or later time points.

Conclusion: Higher plasma concentrations of IL-27, CXCL10, and ADAs at admission were associated with severe COVID-19 and mortality. Reduced TLR-mediated IFNα2, IFNγ, and IL-12p70 production suggests COVID dampens Th1-polarizing innate immune responses, providing insight into immunological sequelae of SARS-CoV-2 infection.

Background: The incidence of intestinal diseases is increasing every year, placing a heavy burden on the world's health and economy. The interaction of immune, microbial, and environmental factors leading to chronic inflammation and immune dysfunction has gradually become a focus of research on the pathogenesis of intestinal diseases. Among them, type 3 innate lymphoid cells (ILC3s) have attracted much attention due to their unique features.

Summary: This paper has been carefully reviewed to provide a comprehensive overview of the roles of ILC3s in maintaining the homeostasis of intestinal flora. Initially, the effects of various intestinal microbiota, including bacteria, fungi, viruses, and pathogenic bacteria, on the function of ILC3s were introduced in detail. Subsequently, it summarizes how ILC3 imbalance disrupts the intestinal barrier and leads to digestive diseases, including infectious diseases, colorectal cancer, inflammatory bowel disease, and irritable bowel syndrome.

Key messages: By reviewing the role of ILC3s in maintaining the homeostasis of the intestinal flora and the current research status of ILC3s imbalance disrupting the intestinal barrier and leading to digestive tract diseases, this review provides potential immunotherapy targets for the future and offers a basis for the construction of future animal models and the conduct of clinical trials.

Background: As sentinel cells of innate immunity, macrophages exhibit microenvironment-driven functional plasticity critical for immune regulation and tissue homeostasis, yet maladaptive metabolic reprogramming-induced polarization dysregulation exacerbates disease progression by manifesting immune dysfunction.

Summary: This review systematically deciphers the metabolic signatures governing macrophage polarization - spanning amino acid metabolism, glycolytic flux, lipid dynamics, and iron homeostasis - while dissecting how pathological microenvironments (encompassing tumor niches, atherosclerotic plaques, and obese adipose tissue) co-opt these pathways to drive pathogenesis. Crucially, this analysis demonstrates that cellular metabolism dictates macrophage phenotypic/functional states across disease contexts, with comprehensive decoding of their metabolic networks emerging as imperative for developing next-generation immunotherapies.

Key messages: Therapeutically, pathogenic polarization may be reversed through strategic interventions targeting metabolite-sensing receptors, pharmacologically blocking metabolic checkpoints, and reprogramming core metabolic modalities to restore immunoregulatory competence.

Background: Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic inflammatory disease of the urinary bladder, characterized by chronic pain, increased urinary frequency, urgency, and nocturia. Currently, no therapeutic option consistently provides long-term relief for all IC/BPS patients, likely due to the largely unknown mechanisms underlying the disease's development and progression. IC/BPS is considered a multifactorial disorder with a complex pathobiology that ultimately leads to unresolved inflammation, bladder dysfunction, and pain.

Summary: Recent research has highlighted chronic inflammation and oxidative stress, resulting from either increased production of reactive oxygen species or their inadequate elimination, as a significant feature of IC/BPS. The frequent co-occurrence of IC/BPS with other chronic diseases characterized by prolonged oxidative stress and subtle chronic inflammation, such as autoimmune diseases, chronic psychological stress, fibromyalgia, and irritable bowel syndrome, suggests a common underlying pathogenic pathway.

Key messages: In this review, we summarize key findings suggesting that oxidative stress and chronic inflammation play a part in the onset and progression of IC/BPS. We explore how oxidative stress contributes to IC/BPS through various mechanisms, including damage to bladder urothelial cells and mitochondria, the activation of innate immune signaling pathways, which together create a self-perpetuating cycle of inflammation. Additionally, we discuss potential therapeutic options and novel drug candidates with anti-inflammatory and antioxidant properties, which could modulate regulatory pathways involved in disease development and provide long-term efficacy in IC/BPS.