Journal of Innate Immunity最新文献

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.

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.

Introduction: Diabetic cardiomyopathy (DCM) is a common complication of diabetes characterized by chronic low-grade inflammation. Exercise has been recognized as an effective intervention for DCM; however, its underlying mechanisms remain incompletely understood.

Methods: Pyroptosis regulation by exercise was examined using DCM and HFD mouse models. In vitro, H9C2 cardiomyocytes were exposed to high glucose or palmitic acid to mimic diabetic condition. The AMPK agonist AICAR was applied to H9C2 cells to reproduce the molecular effects of exercise. WB and caspase-1 activity assays analyzed protein expression and inflammasome activation. Cell death was assessed by cell viability, LDH release, and microscopy.

Results: Exercise attenuated pyroptosis in DCM, prevented the upregulation of P2X4 and PANX1, inhibited NLRP3 activation, and reduced GSDMD and IL-1β cleavage in DCM mouse hearts, without altering P2X7 levels. In HFD-fed obese mice, exercise suppressed P2X4 expression, which correlated with NLRP3 activation, whereas P2X7 remained elevated. In vitro, high glucose alone did not induce significant H9C2 cell death or upregulate P2X4/P2X7 expression, whereas palmitic acid promoted concentration-dependent increases in P2X4 and NLRP3 expression, caspase-1 activity, and necrosis. Exercise and AICAR share a common mechanism in inhibiting NLRP3 inflammasome activation through P2X4, while AICAR exhibits a partial effect on P2X7 compared with exercise.

Conclusion: These findings highlight P2X4 as a critical mediator of NLRP3-driven pyroptosis in the diabetic heart. Exercise ameliorates myocardial inflammation in DCM and appears to act primarily through suppressing P2X4, providing new insight into its cardioprotective mechanisms and suggesting P2X4 as a potential therapeutic target.

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.

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.

Introduction: Macrophages abundantly express liver X receptors (LXRs), which are ligand-dependent transcription factors and sensors of several cholesterol metabolites. In response to agonists, LXRs promote the expression of key lipid homeostasis regulators. Cross talk between LXRs and inflammatory signals exists in a cell type- and gene-specific manner. A common feature in the macrophage response to inflammatory mediators is the induction of CCAAT/enhancer-binding protein beta (C/EBPβ), a master transcriptional regulator and lineage-determining transcription factor in monocytes/macrophages.

Methods: Quantitative real-time PCR in control and C/EBPβ-deficient macrophages was used to explore the role of C/EBPβ in the cross talk between inflammatory mediators and the macrophage response to pharmacological LXR activation. The functional interaction between C/EBPβ and LXRs on selected genomic regions was further characterized by chromatin-immunoprecipitation (ChIP) and gene reporter studies.

Results: Whereas inflammatory signaling repressed several LXR-regulated genes involved in lipid metabolism, these effects were conserved after deletion of C/EBPβ. In contrast, inflammatory mediators and LXRs synergistically induced the expression of the multifunctional protein CD38 in a C/EBPβ-dependent manner. C/EBPβ and LXRs bound to several regions with enhancer activity upstream and within the mouse Cd38 gene and their functional cooperation in macrophages required intact binding sites for LXR and C/EBPβ.

Conclusion: This study reveals positive cross talk between C/EBPβ and LXRs during the macrophage inflammatory response, which selectively impacts CD38 expression.