Chemokine CCL2 Research Articles

Systemic IFN-I combined with topical TLR7/8 agonists promotes distant tumor suppression by c-Jun-dependent IL-12 expression in dendritic cells.

Dendritic cell (DC) activation by pattern recognition receptors like Toll-like-receptors (TLRs) is crucial for cancer immunotherapies. Here, we demonstrate the effectiveness of the TLR7/8 agonist imiquimod (IMQ) in treating both local tumors and distant metastases. Administered orally, IMQ activates plasmacytoid DCs (pDCs) to produce systemic type I interferons (IFN-I) required for TLR7/8 upregulation in DCs and macrophages, sensitizing them to topical IMQ treatment, which is essential for therapeutic efficacy. The mechanism involves c-Jun/AP-1 mediating TLR7/8 signaling in IFN-I-primed DCs, upregulating the pDC-recruiting chemokine CCL2 and the anti-angiogenic cytokine interleukin-12, which suppresses VEGF-A production leading to tumor necrosis and regression. Combining topical and systemic IMQ or IFN-I generates a CD8+ T cell-dependent response at metastatic sites, reinforced by PD-1 blockade, leading to long-lasting memory. Analysis of cohorts of patients with melanoma demonstrates DC-specific TLR7/8 upregulation by IFN-I, supporting the translational potential of combining systemic IFN-I and topical IMQ to improve immunotherapy of topically accessible tumors.

ERG mediates the differentiation of hepatic progenitor cells towards immunosuppressive PDGFRα+ cancer-associated fibroblasts during hepatocarcinogenesis

Cancer-associated fibroblasts (CAFs) play important roles in the occurrence and development of hepatocellular carcinoma (HCC) and are a key component of the immunosuppressive microenvironment. However, the origin of CAFs has not been fully elucidated. We employed single-cell sequencing technology to identify the dynamic changes in different subsets of fibroblasts at different time points in rat primary HCC model. Inflammation-associated CAFs (Pdgfrα+ CAFs) were subsequently identified, which demonstrated a significant correlation with the survival duration of HCC patients and a dual role in the tumour microenvironment (TME). On the one hand, they secrete the chemokines CCL3 and CXCL12, which recruit macrophages to the tumour site. On the other hand, they produce TGFβ, inducing the polarization of these macrophages towards an immunosuppressive phenotype. According to the in vitro and in vivo results, hepatic progenitor cells (HPCs) can aberrantly differentiate into PDGFRα+ CAFs upon stimulation with inflammatory cytokine. This differentiation is mediated by the activation of the MAPK signaling pathway and the downstream transcription factor ERG via the TLR4 receptor. Downregulating the expression of ERG in HPCs significantly reduces the number of PDGFRα+ CAFs and the infiltration of tumour-associated macrophages in HCC, thereby suppressing hepatocarcinogenesis. Collectively, our findings elucidate the distinct biological functions of PDGFRα+ cancer-associated fibroblasts (PDGFRα+ CAFs) within the TME. These insights contribute to our understanding of the mechanisms underlying the establishment of an immunosuppressive microenvironment in HCC, paving the way for the exploration of novel immunotherapeutic strategies tailored for HCC treatment.

Ultrasensitive detection of six sepsis-associated proteins in neonatal saliva

Sepsis is a life-threatening condition that affects millions of newborns every year. Current diagnostic practices require painful, often repetitive, blood collections to isolate and culture the causative microorganism. Definitive return of results can take up to 5 days, exposing newborns to potentially unnecessary antibiotics. Developing a more rapid, non-invasive assessment of infectious status based upon host immune response provides an alternative diagnostic approach to infection screening. However, additional blood collection for multiplex quantification of inflammatory biomarkers in neonates remains prohibitive. Alternatively, saliva may serve as an informative biofluid, though detection of biologically relevant proteins in saliva remains challenging, with analyte concentrations 100 to 1000 times lower compared to blood. To address this challenge, we developed a panel of six ultra-sensitive single-molecule array (Simoa) assays for inflammatory biomarkers known to be associated with neonatal sepsis: serum amyloid A1 (SAA1), lipopolysaccharide-binding protein (LBP), chemokines CCL20, CXCL6, CXCL12; and the adipokine resistin. When these assays were tested on 40 neonatal salivary samples, we found that CXCL6 and CCL20 were significantly elevated in infected and septic neonates compared to those uninfected. The small volumes of fluid used (~10 μL saliva) and limited concentrations of these analytes in saliva (pg/mL) underscore the importance of ultra-sensitive measurements in the development of non-invasive diagnostics and reinforces the value of neonatal saliva as a viable sample matrix for monitoring infection. We hypothesize these assays could be useful in future diagnostic tests to discriminate between infected and uninfected neonates.

Intra-tumoral sphingobacterium multivorum promotes triple-negative breast cancer progression by suppressing tumor immunosurveillance

BackgroundIntratumor-resident bacteria represent an integral component of the tumor microenvironment (TME). Microbial dysbiosis, which refers to an imbalance in the bacterial composition and bacterial metabolic activities, plays an important role in regulating breast cancer development and progression. However, the impact of specific intratumor-resident bacteria on tumor progression and their underlying mechanisms remain elusive.Methods16S rDNA gene sequencing was used to analyze the cancerous and paracancerous tissues from breast cancer patients. The mouse models of bearing 4T1 cell tumors were employed to assess the influence of bacterial colonization on tumor growth. Tissue infiltration of regulatory T (Treg) cells and CD8+ T cells was evaluated through immunohistochemistry and flow cytometric analysis. Comparative metabolite profiling in mice tumors was conducted using targeted metabolomics. Differential genes of tumor cells stimulated by bacteria were analyzed by transcriptomics and validated by qPCR assay.ResultsWe found that Sphingobacterium displayed high abundance in cancerous tissues. Intra-tumoral colonization of Sphingobacterium multivorum (S. multivorum) promoted tumor progression in 4T1 tumor-bearing mice. Moreover, S. multivorum diminished the therapeutic efficacy of αPD-1 mAb, which was associated with the increase of regulatory T cell (Treg) infiltration, and decrese of the CD8+ T cell infiltration. Targeted metabolomics revealed a conspicuous reduction of propionylcarnitine in tumors colonized by S. multivorum Furthermore, the combination of metabolite propionylcarnitine and S. multivorum shown to suppress tumor growth compared that in S. multivorum alone in vivo. Mechanistically, S. multivorum promoted the secretion of chemokines CCL20 and CXCL8 from tumor cells. CCL20 secreted into the TME facilitated the recruitment of Treg cells and reduced CD8+ T cell infiltration, thus promoting tumor immune escape.ConclusionsThis study reveals S. multivorum suppresses immune surveillance within the TME, thereby promoting breast cancer progression.

Carbonic anhydrase IX inhibition as a path to treat neuroblastoma.

Tumour hypoxia frequently presents a major challenge in the treatment of neuroblastoma (NBL). The neuroblastoma cells produce carbonic anhydrase IX (CA IX), an enzyme crucial for the survival of cancer cells in low-oxygen environments. We designed and synthesised a novel high-affinity inhibitor of CA IX. The highest to-date. The affinities were determined for all human catalytically active CA isozymes showing significant selectivity for CA IX over other isozymes. The inhibitor effect on neuroblastoma cancer cell growth was determined in vitro and in vivo via a mice xenograft model. The novel designed inhibitor effectively mitigated the acidification induced by CA IX and reduced spheroid growth under hypoxic conditions in the SK-N-AS cell line. It also diminished the secretion of pro-tumour chemokines IL-8 (CXCL2) and CCL2. When we combined this novel CA IX inhibitor with a compound that inhibits the chemokine receptor CCR2 protein activity, we observed a reduction in mouse tumour growth. The combined treatment also prompted tumours to exhibit adaptive resistance by producing higher levels of vascular endothelial growth factor receptors (VEGFR) and other compensatory signals. This research underscores the pivotal role of CA IX in cancer and the potential of a novel CA IX inhibitor-based combination intervention therapy for neuroblastoma treatment.

Trabectedin enhances the antitumor effects of IL-12 in triple-negative breast cancer.

Interleukin-12 (IL-12) is a potent NK cell-stimulating cytokine, but the presence of immunosuppressive myeloid cells such as myeloid-derived suppressor cells (MDSC) can inhibit IL 12-induced NK-cell cytotoxicity. Thus, we hypothesized that trabectedin, a myeloid cell-depleting agent, would improve the efficacy of IL-12 in triple-negative breast cancer (TNBC). In vitro treatment of healthy donor NK cells with trabectedin increased expression of the activation marker CD69 and mRNA expression of T BET (Tbx21), the cytotoxic ligands TRAIL (TNFSF10) and Fas ligand (FASLG) and the dendritic cell (DC)-recruiting chemokine lymphotactin (XCL1). The combination of IL-12 and trabectedin increased NK-cell cytotoxicity, activation and production of IFN-γ, TNF-α and granzyme B in the presence of human TNBC cells. Treatment of 4T1 and EMT6 tumor-bearing mice with IL-12 and trabectedin led to a significant reduction in tumor burden compared to single-agent controls, and the highest levels of plasma IFN-γ, intratumoral CD8+ T cells and conventional type 1 DC. MDSC and M2-like macrophages were significantly decreased with combination therapy. NK-cell depletion abrogated the effects of combination therapy, as did elimination of CD8+ T cells. NK-cell depletion led to lower levels of the NK cell-derived chemokine CCL5 and the DC-derived chemokine CXCL10, higher tumor burden, and decreased intratumoral CD8+ T cells. IL 12 and trabectedin also significantly enhanced the response of TNBC to anti-PD-L1 therapy. These data suggest that MDSC depletion augments the ability of IL-12-activated NK cells to drive the infiltration of DC and CD8+ T cells into TNBC for an antitumor effect.

HIFU-CCL19/21 Axis Enhances Dendritic Cell Vaccine Efficacy in the Tumor Microenvironment.

Effectively targeting treatment-resistant tumor cells, particularly cancer stem cells (CSCs) involved in tumor recurrence, remains a major challenge in immunotherapy. This study examines the potential of combining mechanical high-intensity focused ultrasound (M-HIFU) with dendritic cell (DC) vaccines to enhance immune responses against OLFM4-expressing tumors, a CSC marker linked to immune evasion and tumor growth. M-HIFU was applied to induce immunogenic cell death by mechanically disrupting tumor cells, releasing tumor-associated antigens and creating an immunostimulatory environment. DC vaccines loaded with OLFM4 were then administered to boost the immune response within this primed environment. The combination of M-HIFU and DC vaccine significantly inhibited tumor growth and metastasis, with enhanced T-cell activation and increased recruitment of immune cells due to elevated chemokines CCL19 and CCL21. This synergy promoted immune memory, reducing the likelihood of recurrence. M-HIFU effectively promotes the migration of DC vaccines through CCL19/21, presenting a promising approach for cancer treatment. Further studies are recommended to optimize this combination for clinical applications, with potential to improve patient outcomes in challenging cancer types.

Immunological Aspect of Septic Shock

Septic shock is clinically characterized by hypotension necessitating vasoactive support that fails to react to fluid resuscitation in patients with suspected or microbiologically confirmed infections leading to severe organ failure without an identified etiology. Predisposing factors for septic shock arises when the body’s reaction to an infection impairs tissue perfusion and oxygen utilization, resulting in end-organ malfunction and heightened mortality risk. The etiologies of septic shock differ between adults and children. The mechanisms contributing to the predisposition for severe sepsis are numerous: diminished complement levels, children’s exposure to outdoor environments or crowded settings, reduced protein levels, accelerated metabolic rates, heightened incidence of heart failure, prior antidotal or clinical exposure, and fluctuating rates of infections caused by pathogenic organisms. Endothelial dysfunction, a primary cause of septic shock, impairs microvascular perfusion and tissue oxygenation in sepsis. Septic shock is commonly linked to coagulation disorders and a heightened prevalence of venous thromboembolism. The principal phases of biomarkers in septic pathobiology encompass a pro-inflammatory and anti-inflammatory phase, along with cellular dysfunction. In summary, the cytokines and chemokines IL-1β, IL-6, IL-8, IL-18, and CCL2 possess considerable predictive significance for septic shock. The new personalized medicine that considers significant immunological indicators may result in more focused therapies in the future. The primary message of this immunological approach is that inflammation, which significantly contributes to the progression of septic shock, is an early occurrence in its pathogenesis.

Single-nucleus transcriptome profiling provides insights into the pathophysiology of adhesive arachnoiditis.

Adhesive arachnoiditis (AA) is a rare form of chronic degenerative pathology associated with persistent inflammation in the arachnoid matter of the spinal cord. Despite the existing knowledge, the detailed pathological mechanisms underlying AA are not fully understood. This study aimed to elucidate through comprehensive single nuclei RNA sequencing (snRNA-seq) to delineate the transcriptomic landscape of AA. From six arachnoid membrane samples, a total of 52,886 cells met the quality control standards for analysis. The main cell populations identified with specific gene markers were as follows: fibroblasts, glial cells, microglial cells, endothelial cells, mural cells, plasma cells, and T cells. Downstream analysis of fibroblasts, glial cells, and microglial cells was performed. Notably, fibroblast subsets 1 and 3 demonstrated a strong association with AA. Among them, subcluster 3 demonstrated elevated expression of genes COL1A1, COL3A1, and FN1, indicative of enhanced Wnt/β-catenin and extracellular matrix (ECM) synthesis pathways. Subcluster 3 was predicted to progressively transform into subcluster 1. In subcluster 1, there was a significant upregulation of genes such as BMP and ALPL, signaling enhanced activation of calcification-related pathways. This was highly relevant to end-stage arachnoid ossification formation. After being activated, microglial cells transformed into inflammatory disease-associated microglial cells and continued to express high levels of chemokines CCL2, CCL4, IL-1β, and other inflammatory factors NAMPT, INPP5D and NLRP3. This might be the main reason why AA recurrence is frequently observed in patients. These insights enhance our understanding of the pathological progression of AA and may contribute to the identification of novel therapeutic targets.

Prognostic Value of CXCL13, CCL11, and CCL20 Chemokines in Multiple Sclerosis.

Objective: The course of relapsing-remitting multiple sclerosis (RRMS) is highly variable and there is a lack of effective prognostic biomarkers. This study aimed to assess the potential prognostic value of the chemokines B lymphocyte chemoattractant molecule (CXCL13), eotaxin-1 (CCL11), and macrophage inflammatory protein 3-alpha (CCL20) in RRMS. Methods: Forty-two patients with MS were enrolled, along with 22 controls, 12 of the controls were idiopathic intracranial hypertension (IIH) patients, and 10 of the controls were other neurologic diseases (OND). Chemokine levels were measured using enzyme-linked immunosorbent assay (ELISA) in serum and cerebrospinal fluid (CSF) samples. Results: No significant differences were observed among the groups in serum levels of CXCL13, CCL11, and CCL20 (p = 0.509, p = 0.979, p = 0.169, respectively). CSF CXCL13 levels were significantly higher in the OND group (p = 0.016). A PATH analysis showed CSF CXCL13 was significantly associated with new T2 hyperintense lesions on brain magnetic resonance imaging (p < 0.001), and baseline serum CCL11 levels were associated with EDSS (p = 0.030), implying its potential role in indicating neurodegenerative processes and possible progression risk. Serum CCL20 correlated with EDSS (p = 0.002) and lesion burden (p < 0.001), reflecting disease severity. Conclusions: These findings suggest that CSF CXCL13 could serve as a useful biomarker for predicting active disease in RRMS, while follow-up serum CCL11 may assist in identifying progression. Although these chemokines are not specific to MS, higher levels may signal disease activity, severity, and transition to more progressive stages.

Tumor infiltration of inactive CD8 + T cells was associated with poor prognosis in Gastric Cancer.

Gastric cancer (GC) shows limited response to immune checkpoint inhibitors due to its complex tumor immune microenvironment (TIME). This study explores the functions of various immune cells in the complex TIME in GC. We assessed CD8 + T-cell infiltration of GC tissues by immunohistochemistry, and performed single-cell RNA sequencing (scRNA-seq) of tumor and normal tissues from 34 patients with GC. We categorized 157 GC patients into LOW, MID, and HIGH groups based on their CD8 + T-cell infiltration. Overall survival was notably lower for the HIGH and LOW groups compared with the MID group. Our scRNA-seq data analysis showed that CD8 + T-cell activity markers in the HIGH group were expressed at lower levels than in normal tissue, but the T-cell-attracting chemokine CCL5 was expressed at a higher level. Notably, CD8 + T-cells in the HIGH group displayed lower PD1 expression and higher CTLA4 expression. TCR repertoire analysis using only Epstein-Barr virus-negative cases showed that CD8 + T-cell receptor clonality was lower in the HIGH group than in the MID group. Furthermore, in the HIGH group, the antigen-presenting capacity of type 1 conventional dendritic cells was lower, the immunosuppressive capacity of myeloid-derived suppressor cells was higher, and the expression of CTLA4 in regulatory T-cells was higher. The present data suggest that the infiltration of inactive CD8 + T-cells with low clonality is induced by chemotaxis in the HIGH group, possibly leading to a poor prognosis for patients with GC.

Potent phytoceuticals cocktail exhibits anti-inflammatory and antioxidant activity on LPS-triggered RAW264.7 macrophages in vitro.

Chronic inflammatory conditions, which include respiratory diseases and other ailments, are characterized by persistent inflammation and oxidative stress, and represent a significant health burden, often inadequately managed by current therapies which include conventional inhaled bronchodilators and oral or inhaled corticosteroids in the case of respiratory disorders. The present study explores the potential of Vedicinals®9 Advanced, a polyherbal formulation, to mitigate LPS-induced inflammation and oxidative stress in RAW264.7 mouse macrophages. The cells were pre-treated with Vedicinals®9 Advanced, followed by exposure to LPS to induce an inflammatory response. Key experimental outcomes were assessed, including nitric oxide (NO) and reactive oxygen species (ROS) production, as well as the expression of inflammatory and oxidative stress-related genes and proteins. Vedicinals®9 Advanced significantly reduced LPS-induced NO and ROS production, indicating strong anti-inflammatory and antioxidant properties. Additionally, the formulation downregulated the LPS-upregulated mRNA expression of pro-inflammatory cytokines, such as TNF-α and CXCL1, and oxidative stress markers, including GSTP1 and NQO1. Furthermore, Vedicinals®9 Advanced downregulated the LPS-induced protein expression of the chemokines CCL2 and CCL6, the LPS co-receptor, CD14, and the pro-inflammatory cytokines G-CSF and IL-1β. These findings highlight the potential of Vedicinals®9 Advanced as a therapeutic option for managing CRDs and other inflammatory conditions. The formulation's ability to simultaneously target inflammation and oxidative stress suggests it may offer advantages over existing treatments, with potential for broader application in inflammatory diseases.

Characteristics of a CCL21-gene modified dendritic cell vaccine utilized for a clinical trial in non-small cell lung cancer.

The treatment of non-small cell lung cancer has made major strides with the use of immune checkpoint inhibitors, but there remains a significant need for therapies that can overcome immunotherapy resistance. Dendritic cell (DC) vaccines have been proposed as a therapy that can potentially enhance the antitumor immune response. We have embarked on a phase I clinical trial of a vaccine consisting of monocyte-derived DCs (moDCs) modified to express the chemokine CCL21 (CCL21-DC) given in combination with pembrolizumab. Here, we report a comprehensive characterization of this CCL21-DC vaccine and interrogate the effects of multiple factors in the manufacturing process. We show that the cellular makeup of the CCL21-DC vaccine is heterogeneous due to the presence of passenger lymphocytes at a proportion that is highly variable among patients. Single cell RNA sequencing of vaccines revealed further heterogeneity within the moDC compartment, with cells spanning a spectrum of DC phenotypes. Transduction with a CCL21-containing adenoviral vector augmented CCL21 secretion by moDCs but otherwise had a minimal effect on vaccine characteristics. A single freeze-thaw cycle for stored vaccines was associated with minor alterations to the DC phenotype, as was the use of healthy donors rather than patient autologous blood. Our results highlight important considerations for the production of DC vaccines and identify underexplored factors that may affect their efficacy and immunologic impact.

Pararamosis, a Neglected Tropical Disease Induced by Premolis semirufa Caterpillar Toxins: Investigating Their Effects on Synovial Cell Inflammation.

Pararamosis, also known as Pararama-associated phalangeal periarthritis, is a neglected tropical disease primarily affecting rubber tappers in the Amazon region. It is caused by contact with the urticating hairs of the Premolis semirufa moth caterpillar, which resides in rubber plantations. The condition is marked by the thickening of the articular synovial membrane and cartilage impairment, features associated with chronic synovitis. Given the significance of synovial inflammation in osteoarticular diseases, in this study, the role of synoviocytes and their interactions with macrophages and chondrocytes are examined when stimulated by Pararama toxins. Synoviocytes and macrophages treated with Pararama hair extract showed an increased production of cytokines IL-6, IL-1β, and TNF-α, indicating a direct effect on these cells. In cocultures, there was a significant rise in inflammation, with levels of IL-1β, IL-6, and chemokines CCL2, CCL5, and CXCL8 increasing up to seven times compared to monocultures. Additionally, matrix-degrading enzymes MMP-1 and MMP-3 were significantly elevated in cocultures. Chondrocytes exposed to the extract also produced IL-6, CCL2, and CCL5, and in cocultures with synoviocytes, there was a notable increase in IL-6, CCL5, and CXCL8, as well as a doubling of MMP-1 and MMP-3 levels. These findings underscore the critical role of cell crosstalk in the inflammatory and catabolic processes associated with pararamosis and demonstrate how Pararama hair extract can influence factors affecting cartilage health, providing valuable insights into this condition.

Discovery of Selective Cyclic d-Sulfopeptide Ligands of the Chemokine CCL22 via Mirror-Image mRNA Display with Genetic Reprogramming.

Chemokines are small proteins involved in recruiting leukocytes to sites of inflammation via interactions with specific cell surface receptors. CCL22 is a chemokine known to play a critical role in inflammatory diseases such as atopic dermatitis and asthma; inhibition of this chemokine therefore represents an attractive therapeutic strategy. Herein, we describe the discovery of cyclic d-sulfopeptide inhibitors of CCL22 identified through mirror-image mRNA display with genetic reprogramming. Chemical synthesis of mirror-image d-CCL22 enabled screening of a cyclic peptide library comprised of all l-amino acids, with reprogramming of l-sulfotyrosine to mimic the presence of this post-translational modification on native chemokine receptors. Enriched macrocyclic peptides were prepared in their mirror-image d-form and assessed for binding against native l-CCL22. The most potent ligand, a plasma-stable d-cyclic peptide bearing four d-sulfotyrosine residues, exhibited nanomolar affinity for CCL22, high selectivity over other chemokines, and nanomolar inhibition of CCL22 signaling through CCR4. This work highlights the vast potential of mirror-image mRNA display technology for discovering proteolytically stable d-peptide inhibitors of protein-protein interactions relevant across a range of therapeutic indications.

Identification of critical residues at the C-terminal tip of ACKR4 regulating chemokine internalization and βarrestin involvement

BackgroundAtypical chemokine receptors (ACKRs) play an important role in regulating the availability of chemokines and are responsible for the formation of chemokine gradients required for the directed migration of immune cells in health and disease. ACKR4 shapes gradients of the chemokines CCL19 and CCL21, which are essential for guiding leukocyte homing to lymphoid organs where they initiate an adaptive immune response against invading pathogens. How ACKRs internalize and scavenge chemokines on the molecular level remains poorly understood. Current state-of the art methods to study βarrestin recruitment, signaling and trafficking of ACKRs - and G-protein-coupled receptors in general - rely heavily on C-terminally tagged receptors with unknown consequences for receptor functions.MethodsFluorescently labelled CCL19 was used to quantify chemokine internalization by native and tagged receptors as assessed by flow cytometry and live cell confocal microscopy. Steady-state interaction and chemokine-driven recruitment of βarrestins was determined by NanoBiT bystander assays. βarrestin-dependency for CCL19 internalization was determined in wild-type versus βarrestin1/2-double deficient cell lines. Statistical significance was determined by unpaired t-test or one-way ANOVA with Dunnett’s or Tukey’s multiple comparison tests.ResultsAddition of a C-terminal tag selectively affected the function of ACKR4, but not other ACKRs. Fusing a short peptide tag or a fluorescent protein to ACKR4 significantly augmented its ability to internalize its cognate ligand CCL19. In comparison to native ACKR4, its C-terminal tagging provoked an elevated pre-association of βarrestins with the plasma membrane, yet a reduction in chemokine-driven βarrestin recruitment. Furthermore, the addition of a C-terminal tag led to a shift from a βarrestin-dependent towards a βarrestin-independent endocytosis pathway. Similar results on chemokine uptake and on βarrestin-dependency were obtained with ACKR4 variants, in which a putative class II PDZ-binding domain located at the C-terminal tip of the receptor was mutated.ConclusionThis study identifies that the integrity of the C-terminus of ACKR4 is critical for receptor function. The addition of a C-terminal tag to ACKR4 enhances chemokine uptake and alters the involvement of βarrestins in receptor trafficking.

Progesterone suppresses rhinovirus-induced airway inflammation by inhibiting neutrophil infiltration and extracellular traps formation

BackgroundThe process of NETosis is observed in a range of inflammatory conditions. Progesterone (P4) has been shown to alleviate inflammation caused by viral infections such as influenza and SARS-CoV-2. However, the precise molecular mechanisms responsible for this effect are not yet fully understood. Therefore, the present investigation aims to explore whether P4 can exert its anti-inflammatory properties by inhibiting NETosis and the related molecular pathways. MethodsAirway inflammation caused by rhinovirus serotype-1b (RV-1b) was induced in male BALB/c mice. The inflammation was assessed through histological examination and calculation of inflammatory cells present in the bronchoalveolar lavage fluid. Flow cytometry was used to analyze the inflammatory cells and NETotic neutrophils. Western blotting analysis was conducted to detect proteins associated with NETosis, inflammasome activation, and signaling. Furthermore, confocal microscopy was utilized to observe neutrophil extracellular trap (NET) structures in vivo tissues and in vitro neutrophils, neutrophil infiltration, and inflammasome formation. ResultsThe administration of P4 proved to be an effective treatment for reducing airway inflammation and the production of NETs caused by RV-1b infection. The infection triggered the activation of NLRP3 inflammasomes in neutrophils, which led to the maturation of IL-1β and subsequent activation of both the NF-κB and p38 signaling pathways. The activation of NF-κB signaling resulted in the secretion of downstream chemokines CCL3 and IL-6, which led to an increase in neutrophil infiltration into the lung airways. Moreover, the activation of p38 signaling led to the generation of reactive oxygen species, resulting in NETosis. However, the administration of P4 inhibited the activation of the NLRP3 inflammasome, which subsequently led to the deactivation of both the IL-1β-NF-κB and IL-1β-p38 axes. As a result, there was a reduction in neutrophil infiltration and NETosis. Furthermore, TGF-β-activated kinase 1 (TAK1) was identified as an intermediary enzyme. P4 inhibits both the NF-κB and IL-1β-p38 pathways by suppressing the activity of TAK1. ConclusionThe capacity of P4 to mitigate rhinovirus-induced airway inflammation is attributed to its ability to impede the infiltration of neutrophils and NETosis. As inflammation mediated by NETosis is widespread in diverse disorders, our findings propose that P4 could potentially function as a universal therapeutic agent in the management of such ailments.

Prognostic Value and Therapeutic Significance of CCL Chemokines in Gastric Cancer.

Gastric cancer is one of the most common malignant tumours of the gastrointestinal tract, which has a significant negative impact on human health. CCL chemokines play important roles in a variety of tumor microenvironments; nevertheless, gastric cancer has surprisingly limited associations with CCL chemokines. In our study, we comprehensively utilized bioinformatics analysis tools and databases such as cBioPortal, UALCAN, GEPIA, GeneMANIA, STRING, and TRRUST to clarify the clinical significance and biology function of CCL chemokines in gastric cancer. The mRNA expression levels of CCL1/3/4/5/7/8/14/15/18/20/21/22/26 were up-regulated, while the mRNA expression levels of CCL2/11/13/16/17/19/23/24/25/28 were down-regulated. The chemokine significantly associated with the pathological stage of gastric cancer is CCL2/11/19/21. In gastric cancer, the expression level of CCL chemokines was not associated with disease-free survival, but low expression of CCL14 was significantly associated with longer overall survival. Therein, associated with the regulation of CCL chemokines are only 10 transcription factors (RELA, NFKB1, STAT6, IRF3, REL, SPI1, STAT1, STAT3, JUN and SP1). The major biological process and functional enrichment of CCL chemokines are to induce cell-directed migration. These results may indicate that CCL chemokines may be immunotherapeutic targets and promising prognostic biomarkers for gastric cancer.

Evaluation of predictive performance of fetal urinary inflammatory markers of postnatal kidney function in fetuses with posterior urethral valves

Abstract Background There are proposed roles for inflammation in the development of congenital obstructive uropathy in the setting of posterior urethral valves (PUV). However, the value of inflammatory proteins as predictive markers of postnatal kidney function, key in the management of fetuses with PUV, has not been explored. We screened fetal urine of fetuses with PUV with a panel of inflammatory proteins to determine their predictive value of postnatal kidney function. Methods Twenty-five different chemokines and cytokines were measured using a multiplex immunoassay in fetal urine of 79 PUV patients from retrospective cohorts, separated in discovery (n = 52) and validation (n = 27). The candidate markers were also quantified in amniotic fluid samples obtained from 16 PUV and 25 other congenital anomalies of the kidney and the urinary tract pregnancies. The performance of validated candidate inflammatory proteins was compared to the previously published 12PUV fetal urine peptide signature. Results Fetal urine chemokines CCL2 (MCP-1), CXCL9 (MIG), and CCL4 (MIP-1β) were identified as predictive of postnatal kidney failure in fetuses with PUV from the discovery cohort. Their predictive potential was confirmed in the validation cohort (AUCs of 0.87, 0.81, and 0.86, respectively). The performance of these individual chemokines was lower than the previously published 12PUV fetal urine peptide signature. However, the combination of the three chemokines performed similarly to 12PUV. In contrast, these three chemokines were not predictive of outcome in amniotic fluid. Conclusions We identified chemokines in fetal urine of PUV pregnancies that, after external validation, could serve as predictive biomarkers of postnatal outcome and contribute to improve prenatal PUV management. Graphical Abstract

Ablation of CCL17-positive hippocampal neurons induces inflammation-dependent epilepsy.

Neuronal cell death and neuroinflammation are characteristic features of epilepsy, but it remains unclear whether neuronal cell death as such is causative for the development of epileptic seizures. To test this hypothesis, we established a novel mouse line permitting inducible ablation of pyramidal neurons by inserting simian diphtheria toxin (DT) receptor (DTR) cDNA into the Ccl17 locus. The chemokine CCL17 is expressed in pyramidal CA1 neurons in adult mice controlling microglial quiescence. Seizure activity in CCL17-DTR mice was analyzed by electroencephalographic recordings following treatment with DT for 3 consecutive days. Neuroinflammation and neuronal cell death were evaluated by (immuno)histochemistry. Pharmacological inhibition of TNFR1 signaling was achieved by treatment with XPro1595, a dominant-negative inhibitor of soluble tumor necrosis factor. Neuronal cell death was detectable7 days (d7) after the first DT injection in heterozygous CCL17-DTR mice. Spontaneous epileptic seizures were observed in the vast majority of mice, often with an initial peak at d6-9, followed by a period of reduced activity and a gradual increase during the 1-month observation period. Microglial reactivity was overt from d5 after DT administration not only in the CA1 region but also in the CA2/CA3 area, shortly followed by astrogliosis. Reactive microgliosis and astrogliosis persisted until d30 and, together with neuronal loss and stratum radiatum shrinkage, reflected important features of human hippocampal sclerosis. Granule cell dispersion was detectable only 3 months after DT treatment. Application of XPro1595 significantly reduced chronic seizure burden without affecting the development of hippocampal sclerosis. In conclusion, our data demonstrate that sterile pyramidal neuronal death is sufficient to cause epilepsy in the absence of other pathological processes. The CCL17-DTR mouse line may thus be a valuable model for further mechanistic studies on epilepsy and assessment of antiseizure medication.