Interaction Of Neutrophils Research Articles

Factor XIII-A Transglutaminase Contributes to Neutrophil Extracellular Trap (NET)-mediated Fibrin(ogen) Network Formation and Crosslinking.

Neutrophil extracellular traps can contribute to thrombosis via stabilization of fibrin network, which is normally conducted by plasma transglutaminase, Factor XIII-A as part of coagulation cascade. The possible presence and activity of FXIII-A in neutrophils or during NETosis are unknown. Here, we investigated potential presence of FXIII-A in neutrophils and participation in NET-fibrin(ogen) interaction in vitro. METHODS: Data mining of human and mouse F13A1/F13a1 mRNA expression in whole-body scRNA sequence atlases was conducted. F13a1 mRNA and protein expression was assessed in isolated mouse bone marrow neutrophils. NETosis was induced using 12-phorbol 13-myristate acetate (PMA), and the transglutaminase activity was assessed with 5-(biotinamido)pentylamine incorporation to plasma fibronectin and a fluorescence-fibrin(ogen)-based activity assay using ATTO488-Cadaverine. Externalization of FXIII-A and its interaction with neutrophil extracellular trap (NET) markers, namely, decondensed DNA, CitH3, and MPO, were examined with immunofluorescence microscopy. NET-fibrin(ogen) interaction was investigated with and without serum and/or transglutaminase inhibitor, NC9. Effect of soluble fibrinogen and fibrin(ogen) network on NETosis was also assessed. Data mining of RNAseq atlases showed F13A1/F13a1 expression in adipose tissue, blood, and bone marrow neutrophils. mRNA expression and protein production were confirmed in isolated neutrophils where expression was comparable to that of macrophages and monocytes. FXIII-A was externalized and active as a transglutaminase and colocalized with NET markers during NETosis. FXIII-A transglutaminase activity promoted NET-fibrin(ogen) interaction and entrapment of neutrophils within fibrin(ogen) matrix. Soluble fibrinogen or fibrin(ogen) network did not induce NETosis. This study identifies neutrophils as a source of FXIII-A and suggests its role in stabilizing NET-fibrin(ogen) matrix structures.

From Cell Interactions to Bedside Practice: Complete Blood Count-Derived Biomarkers with Diagnostic and Prognostic Potential in Venous Thromboembolism.

Venous thromboembolism (VTE), encompassing deep vein thrombosis and pulmonary embolism, is a significant burden on health and economic systems worldwide. Improved VTE management calls for the integration of biomarkers into diagnostic algorithms and scoring systems for risk assessment, possible complications, and mortality. This literature review discusses novel biomarkers with potential diagnostic and prognostic value in personalized VTE management. The pathophysiology of thrombosis starts with cell interactions in the vascular environment and continues with more complex, recently discussed processes such as immunothrombosis and thromboinflammation. Their clinical applicability is in the use of complete blood count (CBC)-derived immuno-inflammatory indices as attractive, readily available biomarkers that reflect pro-thrombotic states. Indices such as the neutrophil-to-lymphocyte ratio (NLR = neutrophil count divided by lymphocyte count), platelet-to-lymphocyte ratio (PLR = platelet count divided by lymphocyte count), and systemic immune-inflammation index (SII = NLR multiplied by platelet count) have demonstrated predictive value for thromboembolic events. Nevertheless, confounding data regarding cutoffs that may be implemented in clinical practice limit their applicability. This literature review aims to investigate neutrophil and platelet interactions as key drivers of immunothrombosis and thromboinflammation while summarizing the relevant research on the corresponding CBC-derived biomarkers, as well as their potential utility in day-to-day clinical practice.

Integrating single-cell RNA-seq and bulk RNA-seq to construct a neutrophil prognostic model for predicting prognosis and immune response in oral squamous cell carcinoma

BackgroundOral squamous cell carcinoma (OSCC) is an aggressive malignancy with poor prognosis. Neutrophil infiltration has been associated with unfavorable outcomes in OSCC, but the underlying molecular mechanisms remain unclear.MethodsThis study integrated single-cell transcriptomics (scRNA-seq) with bulk RNA-seq data to analyze neutrophil infiltration patterns in OSCC and identify key gene modules using weighted gene co-expression network analysis (hdWGCNA). A prognostic model was developed based on univariate and Lasso-Cox regression analyses, stratifying patients into high- and low-risk groups. Immune landscape and drug sensitivity analyses were conducted to explore group-specific differences. Additionally, Mendelian randomization analysis was employed to identify genes causally related to OSCC progression.ResultsSeveral key pathways associated with neutrophil interactions in OSCC progression were identified, leading to the construction of a prognostic model based on significant module genes. The model demonstrated strong predictive performance in distinguishing survival rates between high- and low-risk groups. Immune landscape analysis revealed significant differences in cell infiltration patterns and TIDE scores between the groups. Drug sensitivity analysis highlighted differences in drug responsiveness between high- and low-risk groups.ConclusionThis study elucidates the critical role of neutrophils and their associated gene modules in OSCC progression. The prognostic model provides a novel reference for patient stratification and targeted therapy. These findings offer potential new targets for OSCC diagnosis, prognosis, and immunotherapy.

Decreased neutrophils are associated with reduced risk of Type 2 Diabetes Incidence: Results from the CORDIOPREV study.

Numerous studies have reported an association between neutrophils and T2DM, although this relationship remains unclear. This study aims to investigate the interaction of neutrophils and a dietary intervention on T2DM incidence after 60 months of follow-up. A comprehensive analysis was conducted on the framework of the CORDIOPREV study, which included 462 patients without T2DM at the beginning of the study. They were randomly assigned to either a Mediterranean or a low-fat diet, of whom 107 developed T2DM. Absolute neutrophil counts and other related-ratio, were measured. Kaplan-Meier curves showed that the lowest tertile of basal neutrophils was associated with a reduced likelihood of T2DM incidence when compared to the middle [HR=0.499 (95%CI, 0.287-0.866)] and the highest tertiles [HR=0.442 (95%CI, 0.255-0.768)] in overall population, after adjusting for clinical variables. This association only remained significant in patients who follow a Mediterranean diet when compared the lowest to the middle [HR=0.423 (95% CI, 0.213-0.842)] and the highest tertiles [HR=0.371 (95% CI, 0.182-0.762)]. The predictive capacity yielded an AUC of 0.711 (95%CI: 0.652-0.769), being neutrophils the most important variable in the in the model. Decrease in neutrophils over the 60 months were associated with increased insulin sensitivity index (ISI) (R=-0.31; p=0.019), particularly in patients who followed the Mediterranean diet. These findings suggest that monitoring neutrophils can help prevent the development of T2DM, as a reduction in neutrophil counts could be associated with improved insulin sensitivity. Following a Mediterranean diet might be a potential strategy to reduce the incidence of T2DM by lowering neutrophil levels. Further research is necessary to gain a deeper understanding regarding this mechanism.

Assessing the Effects of Surgical Irrigation Solutions on Human Neutrophil Interactions with Nascent Staphylococcus aureus Biofilms.

Staphylococcus aureus (S. aureus) is the leading cause of surgical site infections (SSIs) and is capable of biofilm growth on implanted foreign devices. The use of surgical irrigation solutions has become a common strategy to combat bacterial contamination events that occur during surgery. Despite their antimicrobial activity, SSI rates remain consistent, suggesting that low-level contamination persists. In these cases, circulating neutrophils must traffic from the blood to contamination sites to aid in bacterial clearance. The influence of irrigation solutions on neutrophils' ability to engage with bacteria has not been explored. The effects of three commonly used irrigation solutions: Xperience (sodium lauryl sulfate), Irrisept (chlorhexidine gluconate), and Betadine® (povidone-iodine) on nascent S. aureus biofilms alone and in the presence of human neutrophils were assessed at manufactured and diluted concentrations. All three solutions, at a 10% dilution, inhibited bacterial growth as demonstrated by culture assays and confocal video microscopy of bacterial aggregate formation. The effects of 10% dilutions of each of these solutions on neutrophil membrane integrity (by flow cytometry and propidium iodide staining) and motility (by confocal video microscopy of neutrophil track length) were investigated with differing outcomes for each irrigation solution. At this concentration only Irrisept preserved neutrophil membrane integrity and motility. Together, this study examines an overlooked aspect of surgical irrigation solutions by investigating their impact on innate immunity and highlights the feasibility of formulations wherein solution effectiveness is complemented by neutrophil function to reduce risks of infection.

The lipid-metabolism enzyme ECI2 reduces neutrophil extracellular traps formation for colorectal cancer suppression

Abnormalities in ether lipid metabolism as well as the formation of neutrophil extracellular traps have recently been recognized as detrimental factors affecting tumorigenesis and progression. However, the role of abnormal ether lipid metabolism in colorectal cancer (CRC) evolution has not been reported. Here we show that the lipid metabolism-related gene enoyl-CoA δ-isomerase 2 (ECI2) plays a tumor-suppressor role in CRC and is negatively associated with poor prognosis in CRC patients. We mechanistically demonstrate that ECI2 reduces ether lipid-mediated Interleukin 8 (IL-8) expression leading to decreased neutrophil recruitment and neutrophil extracellular traps formation for colorectal cancer suppression. In particular, ECI2 inhibits ether lipid production in CRC cells by inhibiting the peroxisomal localization of alkylglycerone phosphate synthase (AGPS), the rate-limiting enzyme for ether lipid synthesis. These findings not only deepen our understanding of the role of metabolic reprogramming and neutrophil interactions in the progression of CRC, but also provide ideas for identifying potential diagnostic markers and therapeutic targets for CRC.

Deciphering the immune-metabolic nexus in sepsis: a single-cell sequencing analysis of neutrophil heterogeneity and risk stratification.

Metabolic dysregulation following sepsis can significantly compromise patient prognosis by altering immune-inflammatory responses. Despite its clinical relevance, the exact mechanisms of this perturbation are not yet fully understood. Single-cell RNA sequencing (scRNA-seq) was utilized to map the immune cell landscape and its association with metabolic pathways during sepsis. This study employed cell-cell interaction and phenotype profiling from scRNA-seq data, along with pseudotime trajectory analysis, to investigate neutrophil differentiation and heterogeneity. By integrating scRNA-seq with Weighted Gene Co-expression Network Analysis (WGCNA) and machine learning techniques, key genes were identified. These genes were used to develop and validate a risk score model and nomogram, with their efficacy confirmed through Receiver Operating Characteristic (ROC) curve analysis. The model's practicality was further reinforced through enrichment and immune characteristic studies based on the risk score and in vivo validation of a critical gene associated with sepsis. The complex immune landscape and neutrophil roles in metabolic disturbances during sepsis were elucidated by our in-depth scRNA-seq analysis. Pronounced neutrophil interactions with diverse cell types were revealed in the analysis of intercellular communication, highlighting pathways that differentiate between proximal and core regions within atherosclerotic plaques. Insight into the evolution of neutrophil subpopulations and their differentiation within the plaque milieu was provided by pseudotime trajectory mappings. Diagnostic markers were identified with the assistance of machine learning, resulting in the discovery of PIM1, HIST1H1C, and IGSF6. The identification of these markers culminated in the development of the risk score model, which demonstrated remarkable precision in sepsis prognosis. The model's capability to categorize patient profiles based on immune characteristics was confirmed, particularly in identifying individuals at high risk with suppressed immune cell activity and inflammatory responses. The role of PIM1 in modulating the immune-inflammatory response during sepsis was further confirmed through experimental validation, suggesting its potential as a therapeutic target. The understanding of sepsis immunopathology is improved by this research, and new avenues are opened for novel prognostic and therapeutic approaches.

The Multifaceted Role of Neutrophils in NSCLC in the Era of Immune Checkpoint Inhibitors.

Lung cancer is the most common cause of cancer-related death in both males and females in the U.S. and non-small-cell lung cancer (NSCLC) accounts for 85%. Although the use of first- or second-line immune checkpoint inhibitors (ICIs) exhibits remarkable clinical benefits, resistance to ICIs develops over time and dampens the efficacy of ICIs in patients. Tumor-associated neutrophils (TANs) have an important role in modulating the tumor microenvironment (TME) and tumor immune response. The major challenge in the field is to characterize the TANs in NSCLC TME and understand the link between TAN-related immunosuppression with ICI treatment response. In this review, we summarize the current studies of neutrophil interaction with malignant cells, T-cells, and other components in the TME. Ongoing clinical trials are aimed at utilizing reagents that have putative effects on tumor-associated neutrophils, in combination with ICI. Elevated neutrophil populations and neutrophil-associated factors could be potential therapeutic targets to enhance anti-PD1 treatment in NSCLC.

Use of artificial intelligence–based digital pathology to predict outcomes for immune checkpoint inhibitor therapy in advanced gastro-esophageal cancer.

4013 Background: Accurate prediction of response and survival outcomes with anti-PD-1/PD-L1 immune checkpoint inhibition (ICI) remains a significant challenge in gastro-esophageal cancers. In this study, we use an artificial intelligence (AI)-based single-cell analysis of digitized whole-slide H&E images (WSIs) to predict objective response and survival benefit of ICI in two independent cohorts of gastro-esophageal cancer patients. Methods: WSIs were obtained from 82 ICI-treated advanced gastroesophageal cancer patients (gastric, esophageal, and gastro-esophageal junction adenocarcinoma and squamous cell carcinoma) at Stanford University for discovery, and 189 ICI-treated advanced gastric adenocarcinoma patients at Southern Medical University for external validation. Deep learning models were deployed for automated tumor area detection and segmentation of cell nuclei within WSIs. We developed a fully automated cell annotation approach by leveraging multiplex immunofluorescence and trained a deep learning model to classify nuclei into four cell types from H&E (tumor cells, lymphocytes, neutrophils, and macrophages). A total of 66 features were computed to quantify cell composition and cell-cell interactions within the tumor microenvironment. Treatment outcomes were assessed using progression-free survival (PFS) and best objective response per the Response Evaluation Criteria in Solid Tumors (v1.1), with statistical significance reported at the 95% confidence level. Results: In the training cohort, a spatial feature characterizing lymphocyte and neutrophil interaction had the strongest association with PFS (hazard ratio = 0.44, 95% CI 0.24-0.79, P = 0.0046). In the validation cohort, the spatial biomarker positive population had significantly improved PFS compared to the spatial biomarker negative population (hazard ratio = 0.41, 95% CI 0.27-0.61, P < 0.0001; median time to event: 19 months vs 9 months). For predicting objective response in the validation cohort, a multivariate model combining the spatial features achieved AUROC = 0.81 compared to AUROC = 0.65 for PD-L1 CPS (P = 0.0014), while combining the multivariate model with PD-L1 CPS achieved AUROC = 0.84. Conclusions: A single-cell computational pathology approachidentifies spatial biomarkers with predictive utility for determining ICI treatment outcomes in advanced gastro-esophageal cancer. Further validation of these findings is being pursued in additional cohorts.

ATP and Formyl Peptides Facilitate Chemoattractant Leukotriene-B4 Synthesis and Drive Calcium Fluxes, Which May Contribute to Neutrophil Swarming at Sites of Cell Damage and Pathogens Invasion.

Here, we demonstrate that human neutrophil interaction with the bacterium Salmonella typhimurium fuels leukotriene B4 synthesis induced by the chemoattractant fMLP. In this work, we found that extracellular ATP (eATP), the amount of which increases sharply during tissue damage, can effectively regulate fMLP-induced leukotriene B4 synthesis. The vector of influence strongly depends on the particular stage of sequential stimulation of neutrophils by bacteria and on the stage at which fMLP purinergic signaling occurs. Activation of 5-lipoxygenase (5-LOX), key enzyme of leukotriene biosynthesis, depends on an increase in the cytosolic concentration of Ca2+. We demonstrate that eATP treatment prior to fMLP, by markedly reducing the amplitude of the fMLP-induced Ca2+ transient jump, inhibits leukotriene synthesis. At the same time, when added with or shortly after fMLP, eATP effectively potentiates arachidonic acid metabolism, including by Ca2+ fluxes stimulation. Flufenamic acid, glibenclamide, and calmodulin antagonist R24571, all of which block calcium signaling in different ways, all suppressed 5-LOX product synthesis in our experimental model, indicating the dominance of calcium-mediated mechanisms in eATP regulatory potential. Investigation into the adhesive properties of neutrophils revealed the formation of cell clusters when adding fMLP to neutrophils exposed to the bacterium Salmonella typhimurium. eATP added simultaneously with fMLP supported neutrophil polarization and clustering. A cell-derived chemoattractant such as leukotriene B4 plays a crucial role in the recruitment of additional neutrophils to the foci of tissue damage or pathogen invasion, and eATP, through the dynamics of changes in [Ca2+]i, plays an important decisive role in fMLP-induced leukotrienes synthesis during neutrophil interactions with the bacterium Salmonella typhimurium.

Neutrophil extracellular traps extrusion from neutrophils stably adhered to ICAM-1 by lipoteichoic acid stimulation

The effect of neutrophil extracellular traps (NETs) on promoting intravascular microthrombi formation and exacerbating the severity of sepsis in patients has gained extensive attention. However, in sepsis, the mechanisms and key signaling molecules mediating NET formation during direct interactions of endothelial cells and neutrophils still need further explored. Herein, we utilized lipoteichoic acid (LTA), a component shared by Gram-positive bacteria, to induce NET extrusion from neutrophils firmly adhered to the glass slides coated with intercellular adhesion molecule-1(ICAM-1). We also used Sytox green to label NET-DNA and Flou-4 AM as the intracellular Ca 2+ signaling indicator to observe the NET formation and fluctuation of Ca 2+ signaling. Our results illustrated that LTA was able to induce NET release from neutrophils firmly attached to ICAM-1-coated glass slides, and the process was time-dependent. In addition, our study indicated that LTA-induced NET release by neutrophils stably adhered to ICAM-1 depended on Ca 2+ signaling but not intracellular reactive oxygen species (ROS). This study reveals NET formation mediated by direct interactions between endothelial ICAM-1 and neutrophils under LTA stimulation and key signaling molecules involved, providing the theoretical basis for medicine development and clinical treatment for related diseases.

Blimp-1 and c-Maf regulate immune gene networks to protect against distinct pathways of pathobiont-induced colitis

Intestinal immune responses to microbes are controlled by the cytokine IL-10 to avoid immune pathology. Here, we use single-cell RNA sequencing of colon lamina propria leukocytes (LPLs) along with RNA-seq and ATAC-seq of purified CD4+ T cells to show that the transcription factors Blimp-1 (encoded by Prdm1) and c-Maf co-dominantly regulate Il10 while negatively regulating proinflammatory cytokines in effector T cells. Double-deficient Prdm1fl/flMaffl/flCd4Cre mice infected with Helicobacter hepaticus developed severe colitis with an increase in TH1/NK/ILC1 effector genes in LPLs, while Prdm1fl/flCd4Cre and Maffl/flCd4Cre mice exhibited moderate pathology and a less-marked type 1 effector response. LPLs from infected Maffl/flCd4Cre mice had increased type 17 responses with increased Il17a and Il22 expression and an increase in granulocytes and myeloid cell numbers, resulting in increased T cell–myeloid–neutrophil interactions. Genes over-expressed in human inflammatory bowel disease showed differential expression in LPLs from infected mice in the absence of Prdm1 or Maf, revealing potential mechanisms of human disease.

Abstract 271: The effects of B-cell acute lymphoblastic leukemia cells on the adipose tissue microenvironment

Abstract Obesity increases the risk of developing many cancers, including breast, colon, kidney, and acute lymphoblastic leukemia (ALL). We have previously shown that ALL cells are recruited to migrate into adipose tissue, where they are protected from chemotherapy. In vitro, ALL cells induce significant changes in adipocytes which may contribute to these protective effects. However, how ALL cells affect the complex cell populations found in adipose tissue in vivo remains unknown. We therefore conducted single-cell RNA sequencing (scRNAseq) of the non-adipocyte stromal vascular fraction (SVF) from adipose tissue in obese mice with and without implanted syngeneic BCR-ABL positive ALL. Differential expression analysis was performed on individual SVF cell types to compare ALL vs. control adipose tissue and pathway enrichment analysis was used in identifying altered molecular processes between conditions. SVF from leukemic mice showed substantial differences in gene expression compared to control mice, suggesting that the ALL potentially induces changes in the microenvironment. Some of the largest differences were found in adipose tissue macrophages, and pathway enrichment analysis identified neutrophil recruitment and regulation as one of the top ten pathways upregulated in adipose macrophages from leukemic mice (4.10 fold enrichment, p<1 × 10-17 by Fisher’s exact test). Selected macrophage genes of interest in this pathway included CYBB (Cytochrome B-245 Beta), a neutrophil interaction gene that has been associated with macrophage infiltration in gastric cancer, was expressed 2.28 log2-fold higher in macrophages from leukemic compared to nonleukemic mice (p<1 × 10−99 by Wilcoxon test). ITGAL (Integrin subunit alpha L), which has been shown to be involved in neutrophil recruitment and implicated in cancer cell growth and transformation was expressed 2.85 log2-fold higher in macrophages from leukemic mice (p<1 × 10−99). Interestingly, adipose from leukemic mice showed a population of neutrophils (1.9% of SVF cells), while neutrophils were largely absent in adipose from nonleukemic mice (<0.1% of SVF cells), which is consistent with macrophage involvement in neutrophil recruitment. Our findings highlight the importance of adipose tissue in the leukemia microenvironment and show that ALL cells can influence this microenvironment in complex ways. Further work will confirm and investigate these cell-cell interactions, potentially improving our understanding of how adipose tissue contributes to cancer mortality. Citation Format: Jia Tan, Michael Cohen, Jessica Ding, In Sook Ahn, Xia Yang, Steven D. Mittelman. The effects of B-cell acute lymphoblastic leukemia cells on the adipose tissue microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 271.

Neutrophils in cancer: dual roles through intercellular interactions.

Neutrophils, the most abundant immune cells in human blood, play crucial and diverse roles in tumor development. In the tumor microenvironment (TME), cancer cells regulate the recruitment and behaviors of neutrophils, transforming some of them into a pro-tumor phenotype. Pro-tumor neutrophils interact with cancer cells in various ways to promote cancer initiation, growth, and metastasis, while anti-tumor neutrophils interact with cancer cells to induce senescence and death. Neutrophils can also interact with other cells in TME, including T cells, macrophages, stromal cells, etc. to exert anti- or pro-tumor functions. In this review, we will analyze the anti- and pro-tumor intercellular interactions mediated by neutrophils, with a focus on generalizing the mechanisms underlying the interaction of neutrophils with tumor cells and T cells. Furthermore, we will provide an overview of cancer treatment strategies targeting neutrophil-mediated cellular interactions.

Neutrophil Extracellular DNA Traps in Response to Infection or Inflammation, and the Roles of Platelet Interactions.

Neutrophils present the host's first line of defense against bacterial infections. These immune effector cells are mobilized rapidly to destroy invading pathogens by (a) reactive oxygen species (ROS)-mediated oxidative bursts and (b) via phagocytosis. In addition, their antimicrobial service is capped via a distinct cell death mechanism, by the release of their own decondensed nuclear DNA, supplemented with a variety of embedded proteins and enzymes. The extracellular DNA meshwork ensnares the pathogenic bacteria and neutralizes them. Such neutrophil extracellular DNA traps (NETs) have the potential to trigger a hemostatic response to pathogenic infections. The web-like chromatin serves as a prothrombotic scaffold for platelet adhesion and activation. What is less obvious is that platelets can also be involved during the initial release of NETs, forming heterotypic interactions with neutrophils and facilitating their responses to pathogens. Together, the platelet and neutrophil responses can effectively localize an infection until it is cleared. However, not all microbial infections are easily cleared. Certain pathogenic organisms may trigger dysregulated platelet-neutrophil interactions, with a potential to subsequently propagate thromboinflammatory processes. These may also include the release of some NETs. Therefore, in order to make rational intervention easier, further elucidation of platelet, neutrophil, and pathogen interactions is still needed.

Impact of Micafungin on Candida auris β-glucan Masking and Neutrophil Interactions.

Invasive fungal pathogen Candida auris has become a public health threat causing outbreaks of high mortality infections. Drug resistance often limits treatment options. For Candida albicans, subinhibitory concentrations of echinocandins unmask immunostimulatory β-glucan, augmenting immunity. Here we analyze the impact of echinocandin treatment of C. auris on β-glucan exposure and human neutrophil interactions. We show subinhibitory concentrations lead to minimal glucan unmasking and only subtle influences on neutrophil functions for the isolates belonging to circulating clades. The data suggest that echinocandin treatment will not largely alter phagocytic responses. Glucan masking pathways appear to differ between C. auris and C. albicans.

Cover Image

The cover image is based on the Original Article Single‐cell sequencing identifies inflammation‐promoting fibroblast–neutrophil interaction in peri‐implantitis by Jia‐ji Mo etal., https://doi.org/10.1111/jcpe.13912.image

The link between neutrophils, NETs, and NLRP3 inflammasomes: The dual effect of CD177 and its therapeutic potential in acute respiratory distress syndrome/acute lung injury.

Neutrophils are important inflammatory effector cells that protect against foreign invasion but also cause self-harm. Numerous neutrophils infiltrate the lungs in acute respiratory distress syndrome/acute lung injury (ARDS/ALI) patients. However, the exact impact of neutrophil infiltration on ARDS's onset and progression remains unclear. To investigate this, we analyzed two ARDS-related datasets from the Gene Expression Omnibus public database and discovered an association between CD177, a neutrophil-specific surface protein, and ARDS progression. We used quantitative flow cytometry to assess CD177+ neutrophils in the peripheral blood of clinical ARDS patients vs healthy controls, finding a significant increase in CD177+ neutrophils percentage among total neutrophils in ARDS patients. This finding was further confirmed in ALI mouse models. Subsequent animal experiments showed that anti-CD177 effectively reduces pulmonary edema, neutrophil infiltration, and inflammatory cytokine release, along with a decrease in reactive oxygen species (ROS) and myeloperoxidase (MPO) levels. We also established an in vitro co-culture system to mimic neutrophil and lung epithelial cell interactions. In the anti-CD177 group, we observed decreased expression of NLRP3, caspase 1, peptidyl arginine deiminase (PAD4), MPO, and ROS, along with a reduction in certain inflammatory cytokines. These results indicate a crucial role for the CD177 gene in ARDS's development and progression. Inhibiting CD177 may help mitigate excessive activation of NLRP3 inflammasomes, ROS, and neutrophil extracellular traps (NETs), thus alleviating ARDS.

Биохимические и иммунологические аспекты патофизиологии острого респираторного дистресс-синдрома

Aim of the study. To analyze publications of scientific studies devoted to the study of biochemical and immunological aspects of the pathophysiology of acute respiratory distress syndrome. Material and methods. An analysis of 54 sources was conducted. The search for articles was carried out in the abstract databases Scopus and Web of Science, as well as in the search engines PubMed, eLIBRARY.RU and Google Scholar, from 2000 to December 2023. Conclusions. The immunological aspect of the pathophysiology of acute respiratory distress syndrome is characterized by the activation of the innate immune system and antigen-presenting cells, which contributes to the initiation of the immune response. In turn, neutrophils release cytotoxic molecules, active oxygen metabolites, bioactive lipids and proinflammatory cytokines and trigger an inflammatory cascade. Cytotoxic molecules cause tissue necrosis, initiate apoptosis and autophagy, which maintains and enhances inflammatory reactions and lung injury, as well as the formation of a vicious circle. Damage to vascular endothelial cells initiates coagulation, promoting the activation of platelets and procoagulant cascades, which leads to the formation of microthrombi in the pulmonary microcirculatory network and fibrin deposition in the intraalveolar and interstitial compartments. The interaction of platelets and neutrophils at the site of endothelial injury is considered a humoral regulatory process. Uncontrolled immunothrombosis can cause concomitant tissue damage and contribute to organ dysfunction.

Ly6G+ Neutrophils and Interleukin-17 Are Essential in Protection against Rodent Malaria Caused by Plasmodium berghei ANKA.

Neutrophils are essential in combating invading pathogens such as Plasmodium parasites, but the participation of their subpopulations and mechanisms in resistance to parasite infection are not fully understood. Our study identified a marked increase in Ly6G+ neutrophils in response to P. berghei ANKA infection. Depletion of these cells rendered mice more susceptible to infection. Elevated interleukin-17 (IL-17) levels, which increased the Ly6G+ neutrophil population, were also found to contribute to this protective effect. IL-17 depletion led to reduced neutrophil numbers and increased susceptibility. Furthermore, dihydroartemisinin (DHA) treatment enhanced neutrophil-mediated immune responses through up-regulation of CD18 and CXCR4 factors. These findings revealed key mechanisms of neutrophil and IL-17 interactions in malaria protection and highlighted DHA's potential to promote neutrophil function in combating malaria.