Neutrophil Expression Research Articles

Effects of water extract of the spleen-brain-related mineral drug Shehanshi on mouse sleep

ObjectiveTo investigate the effects of water extract of the spleen-brain-related mineral drug Shehanshi on mouse sleep. MethodsShehanshi water extract was subjected to component analysis via X-ray photoelectron spectroscopy. Then, the effects of low-dose (50 mg kg-1) and high-dose (100 mg kg-1) Shehanshi water extract on mouse sleep were evaluated through behavioral tests such as pentobarbital sodium subthreshold and above-threshold sleep experiments and autonomic activity experiments. Furthermore, transcriptome sequencing and nontarget metabolomics analysis were performed on the spleen and brain tissues of the mice. ResultsThe Shehanshi water extract contains a total of 30 elements and can reduce sleep latency, increase sleep time, and increase the sleep rate of mice. In the open field experiment, the movement distance of the mice decreased, and the central residence time and rest time increased. Immunoinfiltration analysis and immunohistochemical verification of spleen tissue showed that compared with those in the control group, the immune abundance of neutrophils in the administration groups increased (P < 0.05). Transcriptome data analysis revealed that the Atp1b2 gene was located at the intersection of the spleen and brain and was positively correlated with neutrophil expression but negatively correlated with the expression of the metabolite oleic acid in brain tissue. Immunohistochemical results showed that Atp2a3 protein expression decreased and Plcg1 protein expression increased in the high-dose group, and the difference was statistically significant (P < 0.05). The Atp1b2 protein level in the spleen tissue was positively correlated with that in the brain tissue of the mice (R = 0.829, P = 0.038). Western blotting revealed that Atp1b2 protein levels in the brain and spleen increased significantly in the high-dose group (P < 0.05). ConclusionThe mechanism by which Shehanshi water extract influences sleep may be associated with the expression of genes related to the spleen-brain axis and calcium signaling pathways in brain tissues.

Selective deletion of interleukin-1 alpha in microglia does not modify acute outcome but regulates neurorepair processes after experimental ischemic stroke.

Inflammation is a key contributor to stroke pathogenesis and exacerbates brain damage leading to poor outcome. Interleukin-1 (IL-1) is an important regulator of post-stroke inflammation, and blocking its actions is beneficial in pre-clinical stroke models and safe in the clinical setting. However, the distinct roles of the two major IL-1 receptor type 1 agonists, IL-1α and IL-1β, and the specific role of IL-1α in ischemic stroke remain largely unknown. Here we show that IL-1α and IL-1β have different spatio-temporal expression profiles in the brain after experimental stroke, with early microglial IL-1α expression (4 h) and delayed IL-1β expression in infiltrated neutrophils and a small microglial subset (24-72 h). We examined for the first time the specific role of microglial-derived IL-1α in experimental permanent and transient ischemic stroke through microglial-specific tamoxifen-inducible Cre-loxP-mediated recombination. Microglial IL-1α deletion did not influence acute brain damage, cerebral blood flow, IL-1β expression, neutrophil infiltration, microglial nor endothelial activation after ischemic stroke. However, microglial IL-1α knock out (KO) mice showed reduced peri-infarct vessel density and reactive astrogliosis at 14 days post-stroke, alongside long-term impaired functional recovery. Our study identifies for the first time a critical role for microglial IL-1α on neurorepair and functional recovery after stroke, highlighting the importance of targeting specific IL-1 mechanisms in brain injury to develop more effective therapies.

The role of tumor-associated neutrophils in early luminal HER2-negative breast cancer progression

BACKGROUND: Luminal HER2-negative breast cancer is the most common type of tumor in women diagnosed with early-stage breast cancer. Stromal cells and immune cells in tumor microenvironment have been reported to play a significant role in cancer prognosis. The prognostic role of tumor-associated neutrophils in early breast cancer remains mostly unclear. AIM: To study predictive role tumor-associated neutrophils in early luminal HER2-negative breast cancer. MATERIALS AND METHODS: The dataset consisted of 60 patients with early luminal HER2-negative breast cancer treated in S.P. Botkin City Clinical Hospital (Moscow, Russia). We first estimated basic morphological signs: tumor size, tumor grade (by Nottingham Histologic Score), tumor-infiltrating lymphocytes, lymphovascular invasion, hormonal receptors status, proliferative index, regional lymph nodes status. The expression of intratumoral neutrophils was studied using immunohistochemistry with CD15. RESULTS: High tumor-associated neutrophils concentration was correlated with tumor size, high grade tumors, proliferative index, tumor-infiltrating lymphocytes, lymphovascular invasion and positive regional lymph nodes. CONCLUSION: Tumor-associated neutrophils predicted a worse prognosis in early luminal HER2-negative breast cancer.

Leishmania infantum infection modulates messenger RNA, microRNA and long non-coding RNA expression in human neutrophils in vitro.

In the Americas, L. infantum (syn. chagasi) is the main cause of human visceral leishmaniasis. The role of neutrophils as part of the innate response to Leishmania spp. infection is dubious and varies according to the species causing the infection. Global expression of coding RNAs, microRNAs and long non-coding RNAs changes as part of the immune response against pathogens. Changes in mRNA and non-coding RNA expression resulting from infection by Leishmania spp. are widely studied in macrophages, but scarce in neutrophils, the first cell to encounter the trypanosomatid, especially following infection by L. infantum. Herein, we aimed to understand the expression patterns of coding and non-coding transcripts during acute in vitro infection of human neutrophils by L. infantum. We isolated neutrophils from whole blood of healthy male donors (n = 5) and split into groups: 1) infected with L. infantum (MOI = 5:1), and 2) uninfected controls. After 3 hours of exposure of infected group to promastigotes of L. infantum, followed by 17 hours of incubation, total RNA was extracted and total RNA-Seq and miRNA microarray were performed. A total of 212 genes were differentially expressed in neutrophils following RNA-Seq analysis (log2(FC)±0.58, FDR≤0.05). In vitro infection with L. infantum upregulated the expression of 197 and reduced the expression of 92 miRNAs in human neutrophils (FC±2, FDR≤0.01). Lastly, 5 downregulated genes were classified as lncRNA, and of the 10 upregulated genes, there was only 1 lncRNA. Further bioinformatic analysis indicated that changes in the transcriptome and microtranscriptome of neutrophils, following in vitro infection with L. infantum, may impair phagocytosis, apoptosis and decrease nitric oxide production. Our work sheds light on several mechanisms used by L. infantum to control neutrophil-mediated immune response and identifies several targets for future functional studies, aiming at the development of preventive or curative treatments for this prevalent zoonosis.

Comprehensive genomic and transcriptomic profiling of pulmonary nodules in synchronous multiple primary lung cancer.

e20022 Background: Synchronous Multiple Primary Lung Cancer (sMPLC) exhibits distinct histopathological characteristics among pulmonary nodules. However, a comprehensive understanding of the somatic mutation landscape and transcriptome heterogeneity is lacking. Therefore, our study aims to meticulously investigate genomic distinctions among multiple pulmonary nodules within individual patients. Methods: We performed targeted sequencing on tumor specimens and conducted bulk RNA transcriptome analysis on 53 multiple nodules originating from 26 lung cancer patients. The multiple nodules from the same patient was determined as major nodule and minor nodule. Additionally, the tumor tissues underwent histopathological evaluation through H&amp;E staining, complemented by a comprehensive series of immunohistochemistry (IHC) analyses to detect protein expression. The detected protein markers encompassed PD-L1, Ki67, and others. Results: For the 53 nodule samples from 26 MPLCs patients, EGFR was the mostly mutated genes, and the TP53 mutation frequency demonstrated notably different between major and minor nodules. Furthermore, pathway enrichment analysis based on the differentially expressed genes (DEGs) between major and minor nodules revealed the significantly active cell cycle and p53 pathways in the major nodules. Additionally, both major and minor nodules demonstrated mostly similar immune microenvironment and PD-L1 protein expression, and a significantly higher expression of Ki67. A noteworthy suppression was observed in the immune microenvironment in nodules, revealed by the expression of macrophage, neutrophils, and NK cells. Furthermore, minor nodules exhibited a modestly elevated expression of macrophages compared to major nodules. Additionally, among the significantly up-regulated cell cycle related genes in the major nodules when compared with minor nodules, CCNE1 mRNA expression demonstrated significant correlation with poor prognosis in the lung cancer. Conclusions: This study validated molecular distinctions between samples from major and minor nodules in patients with sMPLC at both genomic and transcriptomic levels. The major nodules exhibited heightened activity in tumor cell proliferation pathways and demonstrated malignancy-related biological characteristics, which correlated with pathological assessment results.

#1766 Mincle receptor in macrophage and neutrophil contributes to the unresolved inflammation during the transition from AKI to CKD

Abstract Background and Aims Recent studies have demonstrated a strong association between acute kidney injury (AKI) and chronic kidney disease (CKD). Unresolved inflammation may contribute to the AKI-to-CKD transition. As a transmembrane pattern recognition receptor, Mincle (macrophage-inducible C-type lectin, Clec4e) was previously reported to be critical in the early immune response after AKI. However, the impact of Mincle on the chronic transition from AKI remains poorly understood. Method We performed single-cell RNA sequencing (scRNA-seq) with the clinically relevant unilateral ischemia-reperfusion (UIR) murine model of AKI at days 1, 3, 14 and 28 after injury. Potential effects and mechanism of Mincle on renal inflammation and fibrosis were further validated in vivo utilizing Mincle knockout mice. Results Single-cell transcriptome analysis showed predominant Mincle expression in macrophages and neutrophils during the AKI-to-CKD transition. For both cell types, Mincle was significantly upregulated on day 1 after AKI which decreased gradually in later stages, and exhibited a secondary peak at day 14. Flow cytometry confirmed the increased infiltration of Mincle-positive macrophages and neutrophils post-UIR. Next, we identified distinct subclusters of Minclehigh neutrophils and Minclehigh macrophages, both displaying time-dependent influx with dual peaks on day 1 and day 14 and significant pro-inflammatory and pro-fibrotic phenotypes as indicated by functional gene scoring. Spatial transcriptomics data showed a pronounced expression of Mincle at the outer medulla in the kidney similar to myeloid cells, possibly correlating with fibrotic areas represented by α-SMA patterns. To further elucidate the mechanisms underlying AKI-to-CKD transition mediated by Mincle-expressing macrophages and neutrophils, we identified 54 common genes from the up-regulated genes of these two cell subsets, which were involved in immune-inflammatory responses and extracellular matrix synthesis. Importantly, TNF-α was revealed as a pivotal hub gene and strongly associated with Mincle in these two Mincle-expressing subclusters. Correspondingly, a prominent increase in TNF-α expression primarily in macrophages and neutrophils on days 1 and 14 was confirmed, displaying consistent patterns with Mincle expression. Meanwhile, significant TNF-α reduction specifically in macrophages and neutrophils on day 14 was observed in Mincle knockout mice. Remarkably, Mincle-deficient mice showed improved renal pathology and reduced extracellular matrix deposition, accompanied by notable mRNA down-regulation of pro-inflammatory factors (TNF-α, IL-1β, Ccl2) and fibrosis associated factors (TGF-β, α-SMA, COL1A1) as well as decreased immune cells infiltration. Conclusion Together, the present findings have unveiled combined persistence of Minclehigh neutrophils and macrophages during AKI-to-CKD transition, contributing to unresolved inflammation followed by fibrosis via TNF-α as a central pro-inflammatory cytokine. Targeting Mincle may offer a novel therapeutic strategy for preventing the transition from AKI to CKD.

The interaction of Pu.1 and cMyb in zebrafish neutrophil development.

Granulopoiesis is a highly ordered and precisely regulated process in which hematopoietic-related transcription factors play crucial roles. These transcription factors form complex regulatory networks through interactions with their co-factors or with each other, and anomalies in these networks can lead to the onset of leukemia. While the structures and functions of dozens of transcription factors involved in this process have been extensively studied, research on the regulatory relationships between these factors remains relatively limited. PU.1 and cMYB participate in multiple stages of neutrophil development, and their abnormalities are often associated with hematologic disorders. However, the regulatory relationship between these factors in vivo and their mode of interaction remain unclear. In this study, zebrafish models with cMyb overexpression (cmybhyper) and Pu.1 deficiency (pu.1G242D/G242D) were utilized to systematically investigate the interaction between Pu.1 and cMyb during granulopoiesis through whole-mount in situ hybridization, qRT-PCR, fluorescence reporting systems, and rescue experiments. The results showed a significant increase in cmyb expression in neutrophils of the pu.1G242D/G242D mutant, while there was no apparent change in pu.1 expression in cmybhyper. Further experiments involving injection of morpholino (MO) to decrease cmyb expression in pu.1G242D/G242D mutants, followed by SB and BrdU staining to assess neutrophil quantity and proliferation, revealed that reducing cmyb expression could rescue the abnormal proliferation phenotype of neutrophils in the pu.1G242D/G242D mutant. These findings suggest that Pu.1 negatively regulates the expression of cMyb during neutrophil development. Finally, through the construction of multi-site mutation plasmids and a fluorescent reporter system, confirmed that Pu.1 directly binds to the +72 bp site in the cmyb promoter, exerting negative regulation on its expression. In conclusion, this study delineates that Pu.1 participates in neutrophil development by regulating cmyb expression. This provides new insights into the regulatory relationship between these two factors and their roles in diseases.

Alterations in the immune landscape characterized by inflammatory activation and immune escape within 12 h after trauma

BackgroundTrauma is statistically a significant cause of mortality among patients across countries. Nevertheless, the precise correlation between genetic diagnostic markers and the intricate mechanism of trauma remains indistinct. MethodsOur study exclusively centered on trauma patients and selected three trauma-related datasets from the Gene Expression Omnibus (GEO) database, all of which had blood samples collected within post-traumatic 12 h. Differential gene screening, the WGCNA and Cytoscape software were employed to analyze the two datasets, with a particular emphasis on the top 100 genes selected based on MCC algorithm scores. A logistic diagnostic model was constructed by analyzing the intersection genes in the third dataset, leading to the identification of diagnostic biomarkers with high efficiency. The global immune landscape of these patients was extensively investigated using a multidimensional approach. Meanwhile, the underlying pathological and physiological mechanisms associated with early trauma status are summarized by integrating existing literature. ResultsOut of these two GEO datasets, 21 overlapping genes were identified and incorporated into in the logistic diagnostic model constructed in the GSE36809 dataset. A panel of 9 genes was uncovered as a diagnostic biomarker, and their expression and correlation were subsequently verified. Additionally, by virtue of various algorithms, the findings revealed an upregulation of neutrophil expression and a downregulation of CD8+ T cell expression, indicating characteristic early trauma-induced inflammation activation and immune suppression. The correlation observed between the feature genes and immune cells serves to validate the exceptional diagnostic capability of these 9 genes in identifying trauma status and their promising potential for patients who could benefit from targeted immune interventions. Drawing from these findings, the discussion section offers insights into the underlying pathological and physiological mechanisms at play. ConclusionOur research has discovered a novel diagnostic biomarker and unveiled its association with post-traumatic immune alterations. This breakthrough enables accurate and timely diagnosis of early trauma, facilitating the implementation of appropriate healthcare interventions.

Identification of fibronectin type III domain containing 3B as a potential prognostic and therapeutic target for pancreatic cancer: a preliminary analysis

BackgroundFibronectin type III domain containing 3B (FNDC3B), a member of the fibronectin type III domain-containing protein family, has been indicated in various malignancies. However, the precise role of FNDC3B in the progression of pancreatic cancer (PC) still remains to be elucidated.MethodsIn this study, we integrated data from the National Center for Biotechnology Information, the Cancer Genome Atlas, Genotype-Tissue Expression database, and Gene Expression Omnibus datasets to analyze FNDC3B expression and its association with various clinicopathological parameters. Subsequently, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes, along with Gene Set Enrichment Analysis (GSEA), single sample Gene Set Enrichment Analysis (ssGSEA) and estimate analysis were recruited to delve into the biological function and immune infiltration based on FNDC3B expression. Additionally, the prognostic estimation was conducted using Cox analysis and Kaplan–Meier analysis. Subsequently, a nomogram was constructed according to the result of Cox analysis to enhance the prognostic ability of FNDC3B. Finally, the preliminary biological function of FNDC3B in PC cells was explored.ResultsThe study demonstrated a significantly higher expression of FNDC3B in tumor tissues compared to normal pancreatic tissues, and this expression was significantly associated with various clinicopathological parameters. GSEA revealed the involvement of FNDC3B in biological processes and signaling pathways related to integrin signaling pathway and cell adhesion. Additionally, ssGSEA analysis indicated a positive correlation between FNDC3B expression and infiltration of Th2 cells and neutrophils, while showing a negative correlation with plasmacytoid dendritic cells and Th17 cells infiltration. Kaplan–Meier analysis further supported that high FNDC3B expression in PC patients was linked to shorter overall survival, disease-specific survival, and progression-free interval. However, although univariate analysis demonstrated a significant correlation between FNDC3B expression and prognosis in PC patients, this association did not hold true in multivariate analysis. Finally, our findings highlight the crucial role of FNDC3B expression in regulating proliferation, migration, and invasion abilities of PC cells.ConclusionDespite limitations, the findings of this study underscored the potential of FNDC3B as a prognostic biomarker and its pivotal role in driving the progression of PC, particularly in orchestrating immune responses.

Role of Lipocalin-2 in N1/N2 Neutrophil Polarization After Stroke.

Neutrophils and Lipocalin-2 (LCN2) play pivotal roles in cerebral ischemiareperfusion (I/R) injury. However, their contribution is not fully clarified. This study aimed to explore the role of LCN2 and its association with neutrophil polarization in I/R injury. A mouse model of middle cerebral artery occlusion (MCAO) was used to induce cerebral ischemia. LCN2mAb was administered 1 h and Anti-Ly6G was administered for 3d before MCAO. The role of LCN2 in the polarity transition of neutrophils was explored using an in vitro HL-60 cell model. LCN2mAb pretreatment had neuroprotective effects in mice. The expression of Ly6G was not significantly different, but the expression of N2 neutrophils was increased. In the in vitro study, LCN2mAb-treated N1-HL-60 cells induced N2-HL-60 polarization. LCN2 may affect the prognosis of ischemic stroke by mediating neutrophil polarization.

Verification of the expression trend and interaction prediction of innate immune cells and immune-checkpoint molecules in the process of oral mucosal carcinogenesis.

This study aimed to explore the expression trends of innate immune cells and immune-checkpoint molecules validated by data calculation in the process of oral mucosal carcinogenesis, as well as to explore methods of suppressing oral mucosal carcinogenesis based on immunotherapy by predicting their interactions. Me-thods 1) The cancer genome atlas (TCGA) database comprehensively scores immune cells and immune-checkpoint molecules in the process of oral mucosal carcinogenesis and screens out intrinsic immune cells and immune-checkpoint molecules that interfere with tumor immune escape. 2) Clinical patient blood routine data were collected for the statistical analysis of peripheral blood immune cells during the progression of oral mucosal carcinogenesis. Immune cells in peripheral blood that may affect the progression of oral mucosal carcinogenesis were screened. 3) Immunohistochemical staining was performed on intrinsic immune cells and immune-checkpoint molecules validated based on data calculation in various stages of oral mucosal carcinogenesis. 4) Special staining was used to identify innate immune cells in various stages of oral mucosal carcinogenesis based on data-calculation verification. 5) Survival analysis was conducted on intrinsic immune cells and immune-checkpoint molecules validated based on data calculation during the process of oral mucosal carcinogenesis. The association of intrinsic immune cells and immune-checkpoint molecules with the prognosis of oral squamous cell carcinoma was verified. The expression of monocytes and neutrophils increased during the process of oral mucosal carcinogenesis. The expression of eosinophils showed a single peak trend of up and down. The expression of mast cells decreased. In the process of oral mucosal carcinogenesis, the expression of the immune-checkpoint molecules cytotoxic T-lymphocyte-associated protein 4 (CTLA4) and programmed cell death-ligand (PD-L1) increased. The expression trends of monocytes, neutrophils, and eosinophils were positively correlated with those of CTLA4 and PD-L1 immune-checkpoint molecules. The expression trend of mast cells was negatively correlated with the expression of CTLA4 and PD-L1. Monocytes, neutrophils, and eosinophils may promote tumor immune escape mediated by CTLA4 and/or PD-L1, thereby accelerating the progression of oral mucosal carcinogenesis. Mast cells may inhibit tumor immune escape mediated by CTLA4 and/or PD-L1, delaying the progression of oral mucosal carcinogenesis. Therefore, interference with specific immune cells in innate immunity can regulate the expression of CTLA4 and/or PD-L1 to a certain extent, inhibit tumor immune escape, and delay the progression of oral mucosal carcinogenesis.

Drug Repurposing of ACT001 to Discover Novel Promising Sulfide Prodrugs with Improved Safety and Potent Activity for Neutrophil-Mediated Antifungal Immunotherapy.

Neutrophil-mediated immunotherapy is a promising strategy for treating Candida albicans infection due to its potential in dealing with drug-resistant events. Our previous study found that ACT001 exhibited good antifungal immunotherapeutic activity by inhibiting PD-L1 expression in neutrophils, but its strong cytotoxicity and high BBB permeability hindered its antifungal application. To address these deficiencies, a series of novel sulfide derivatives were designed and synthesized based on a slow-release prodrug strategy. Among these derivatives, compound 16 exhibited stronger inhibition of PD-L1 expression, less cytotoxicity to neutrophils, and lower BBB permeability than ACT001. Compound 16 also significantly enhanced neutrophil-mediated antifungal immunity in C. albicans infected mice, with acceptable pharmacokinetic properties and good oral safety. Moreover, pharmacological mechanism studies demonstrated that ACT001 and compound 16 reduced PD-L1 expression in neutrophils by directly targeting STAT3. Briefly, this study provided a novel prototype compound 16 which exhibited great potential in neutrophil-mediated antifungal immunotherapy.

Wiskott-Aldrich syndrome protein expression in female WAS carriers: A flow cytometry study from North India.

Wiskott-Aldrich syndrome (WAS) is a rare X-linked inborn error of immunity characterized by microthrombocytopenia, infections, eczema, and increased predisposition to develop autoimmunity and malignancy. Flow cytometric assay for determining WAS protein (WASp) is a rapid and cost-effective tool for detecting patients. However, very few studies described WASp expression in female carriers. Most WAS carriers are clinically asymptomatic. Active screening of female family members helps identify female carriers, distinguish de novo mutations, and to select appropriate donor prior to curative stem cell transplantation. This study was undertaken to evaluate the diagnostic capability of flow cytometry-based WASp expression in peripheral blood cells to identify carriers and compare WASp expression in different blood cell lineages. Female patients, heterozygous for WAS gene, were enrolled in this study conducted at Pediatric Allergy Immunology Unit, Advanced Pediatric Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India. Flow cytometric assessment of WASp expression in lymphocytes, monocytes, and neutrophils was carried out and compared with healthy control and affected patients. The results were expressed in delta (Δ) median fluorescence intensity (MFI) as well as stain index (SI), which is the ratio of ΔMFI of patient and ΔMFI of control. Thirteen mothers and two sisters of genetically confirmed WAS patients were enrolled in the study. All enrolled females were clinically asymptomatic and did not have microthrombocytopenia. Low WASp expression (SI<1) was seen in lymphocytes and monocytes in 10 (66.6%) carriers. Females with variants in proximal exons (exons 1 and 2) were found to have lesser expression than those with distal (exons 3-12) variants. Flow cytometry is a rapid, easily available, cost-effective tool for WASp estimation. Lymphocytes followed by monocytes are the best cell lineages for WASp estimation in carrier females. However, genetic testing remains the gold standard, as carrier females with variants in distal exons may have normal WASp expression.

Abstract 1518: Understanding the role of VISTA in regulating T cells function and the therapeutic potential of blocking VISTA in triple negative breast cancer

Abstract Immune checkpoint inhibitors (ICIs) targeting immune modulatory molecules have been widely used and have shown therapeutic efficacy in treating multiple malignancies in the last decade. However, in triple-negative breast cancer (TNBC), only around 5 % of patients showed a durable response to ICIs. While the response rates were increased up to 10% by combining ICIs with conventional chemotherapy, the majority of the patients did not respond to the treatment. Thus, there is a need to improve our understanding of the mechanism underlying unequal response to ICIs in TNBC and develop/discover new treatments to improve patient outcomes. The lack of response to ICIs has been attributed to the increased infiltration of immunosuppressive cells (including MDSCs, neutrophils and TAMs), as well as the presence of additional immune checkpoint receptors/ligands that may further suppress cytotoxic T cells (CD8+ T cells) in the tumor microenvironment (TME). V-domain Ig suppressor of T-cell activation (VISTA) is one of the immune checkpoint molecules attracting increasing attention in the context of anti-tumor immunity due to its broad expression across various cancer types and increased expression upon development of immune checkpoint resistance. However, the role of VISTA in the anti-tumor immune response and its therapeutic potential in TNBC remains unclear. In our study, we observed that VISTA is expressed in TNBC patients, with higher expression in neutrophils and macrophages. In the Py230 murine breast cancer model, VISTA expression increased upon paclitaxel (PTX), anti-PD-L1 and paclitaxel combined with anti-PD-L1 treatment compared to the control group, suggesting its potential role as a resistance mechanism in further inhibiting T cells. In the Py230 model, VISTA blockade increased the infiltration and activation of CD8+ T cells, as evidenced by the higher number of CD8+ T cells, increased CD69+CD8+ T cells, and Granzyme B production, indicating that VISTA blockade improved CD8+ T cells mediated anti-tumor immunity. To functionally test the role of VISTA, we stimulated CD8+ T cells and co-cultured them with naïve macrophages or tumor educated macrophages in the presence or absence of VISTA blocking antibody. Tumor-educated macrophages showed increased immunosuppressive activity which is abrogated with VISTA blockade. Moreover, we found that the immunosuppressive effect of macrophages on T cell activation needs direct cell interaction between VISTA on macrophages and T cells. In conclusion, this study shows the mechanism of action of VISTA in the regulation of T cells mediated anti-tumor immune response, and provides the rationale for blocking VISTA in TNBC. Citation Format: Maidinaimu Abudula, Yuliana Astuti, Meirion Raymant, Teifion Luckett, Patrick Freeman, Michael Schmid, Ainhoa Mielgo Iza. Understanding the role of VISTA in regulating T cells function and the therapeutic potential of blocking VISTA in triple negative breast cancer [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 1518.

Abstract 3679: Development and validation of prognostic signatures comprising neutrophil-specific long non-coding RNAs (LncRNAs) for predicting survival in urothelial carcinoma

Abstract Background: Tumor-associated neutrophils profoundly influence the tumor immune microenvironment (TME), impacting urothelial carcinoma (UC) progression, metastasis, and survival. Long non-coding RNAs (lncRNAs) have emerged as critical players in cancer biology. Recognizing neutrophils as influential contributors to tumor biology, our study aimed to explore neutrophil-specific lncRNAs and evaluate their prognostic significance in UC. Methods: In the GSE24890 dataset, 46 lncRNAs were identified with elevated expression in neutrophils compared to other immune cells, thus designating them as neutrophil-specific lncRNAs. To establish a tailored prognostic model, the TCGA BLCA dataset served as the internal training set. Candidate lncRNAs underwent filtration and selection through univariate Cox regression analysis, followed by the construction of a risk score employing LASSO and multivariate Cox regression algorithms. We used IMVigor210 dataset as external validation for this lncRNA model. Results: Ten lncRNAs exhibiting correlation with overall survival (OS) were initially identified through univariate Cox regression. Following LASSO regression and subsequent multivariate Cox regression analysis, a refined set of 9 lncRNAs was selected to construct the risk model, represented by the formula: Risk score = (-0.096 × FAM13A-AS1 expression level) + (0.157 × FAM27C expression level) + (-0.294 × HCG27 expression level) + (-0.037 × HOTAIRM1 expression level) + (-0.137 × LINC-PINT expression level) + (-0.279 × LINC00612 expression level) + (-0.058 × LINC00967 expression level) + (0.187 × LINC01018 expression level) + (-0.288 × LINC01138 expression level). Kaplan-Meier survival analysis of the BLCA cohort revealed that patients in the high-risk group experienced significantly worse OS compared to those in the low-risk group (p &amp;lt; 0.001). The area under the curve (AUC) values at 1, 3, and 5 years were 0.66, 0.67, and 0.66, respectively. In the multivariate Cox regression model, the risk score remained an independent prognostic factor (p &amp;lt; 0.001; HR 2.5; 95% CI 1.91-3.30). The validity of the risk score was further confirmed in the IMVigor210 dataset, demonstrating discriminative predictive ability for OS between high- and low-risk groups (p = 0.027). Conclusions: This study underscores the interplay between neutrophils and lncRNAs in UC. Neutrophil-related lncRNAs identified may serve as promising therapeutic targets and prognostic markers for UC. Citation Format: Harvey Yu-Li Su, Chang-Ting Lin, Shih-Yu Huang, Yi-Hua Chen, Chung-Wen Kuo. Development and validation of prognostic signatures comprising neutrophil-specific long non-coding RNAs (LncRNAs) for predicting survival in urothelial carcinoma [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 3679.

Association between the Reduced Expression of RECK and Neutrophilic Inflammation in Chronic Obstructive Pulmonary Disease

Introduction: Reversion-inducing cysteine-rich protein with Kazal motifs (RECK), a recently discovered inhibitor of matrix metalloproteinase (MMP). There is a large number of chronic obstructive pulmonary disease (COPD) patients worldwide; however, the role of RECK on COPD has not been studied. This study explored the expression of RECK in COPD patients and its effect on neutrophil function to provide a new scientific basis for the prevention and treatment of COPD. Method: Fifty patients with acute exacerbation of COPD and fifty healthy controls were enrolled in the study. RECK was detected in lung tissue, sputum, and plasma of subjects as well as in BEAS-2B cells stimulated with cigarette smoke extract (CSE) by immunohistochemistry, ELISA, and qRT-PCR. Meanwhile, lung function (FEV1%pred) and inflammatory cytokines (IL-6 and IL-8) were examined, and correlation analysis was performed with RECK expression. The effect of RECK on proliferation, apoptosis, migration, and inflammatory cytokines and its potential mechanism was further quantified by neutrophil stimulated with recombinant human RECK protein (rhRECK) combined with CSE using CCK8, flow cytometry, Transwell assay, qRT-PCR, ELISA, and Western analysis. Results: RECK was mainly expressed on airway epithelial cells in normal lung tissue and was significantly diminished in COPD patients. The levels of RECK in sputum and plasma were also significantly decreased in COPD patients. Pearson correlation analysis showed that RECK level in plasma was positively correlated with FEV1%pred (r = 0.458, p < 0.001) and negatively correlated with IL-6 and IL-8 (r = −0.386, −0.437; p = 0.006, 0.002) in COPD patients. The expression of RECK was decreased in BEAS-2B stimulated with CSE. The migration, inflammation, and MMP-9 expression of neutrophils were promoted by CSE, while inhibited by rhRECK. Conclusion: RECK is low expressed in COPD patients and negatively correlated with inflammation. It may inhibit the inflammation and migration of neutrophils by downregulating MMP-9.

Dysfunctional neutrophil type 1 interferon responses in preschool children with recurrent wheezing and IL-4–mediated aeroallergen sensitization

BackgroundThe innate mechanisms associated with viral exacerbations in preschool children with recurrent wheezing are not understood. ObjectiveWe assessed differential gene expression in blood neutrophils from preschool children with recurrent wheezing, stratified by aeroallergen sensitization, at baseline and after exposure to polyinosinic-polycytidylic acid (poly(I:C)). We also examined whether poly(I:C)-stimulated blood neutrophils influenced airway epithelial gene expression. MethodsBlood neutrophils were purified and cultured overnight with poly(I:C) and underwent next-generation sequencing with Reactome pathway analysis. Primary human small airway epithelial cells were treated with poly(I:C)-treated neutrophil culture supernatants and were analyzed for Type 1 interferon gene expression with a targeted array. Symptoms and exacerbations were assessed in participants over 12 months. Results436 genes were differently expressed in neutrophils from children with versus without aeroallergen sensitization at baseline, with significant downregulation of Type 1 interferons. These Type 1 interferons were significantly upregulated in sensitized children after poly(I:C) stimulation. Confirmatory experiments demonstrated similar upregulation of Type 1 interferons in IL-4 treated neutrophils stimulated with poly(I:C). Poly(I:C)-treated neutrophil supernatants from children with aeroallergen sensitization also induced a Type 1 interferon response in epithelial cells. Children with aeroallergen sensitization also had higher symptom scores during exacerbations and these symptom differences persisted for three days after prednisolone treatment. ConclusionsType 1 interferon responses are dysregulated in preschool children with aeroallergen sensitization, which is in turn associated with exacerbation severity. Given the importance of Type 1 interferon signaling in viral resolution, additional studies of neutrophil Type 1 interferon responses are needed in this population.

The Effect of Cytokine Adsorption on Leukocyte and Platelet Activation after Extracorporeal Cardiopulmonary Resuscitation.

Post-cardiac arrest syndrome (PCAS) is a frequent complication following successful cardiopulmonary resuscitation and correlates with poor outcome. PCAS is characterized by an excessive inflammatory response to whole-body ischemia and reperfusion. Cytokine adsorption was suggested as an adjunctive treatment option for the removal of cytokines from the patients' blood to restore the physiological equilibrium of pro- and anti-inflammatory activity and thus mitigate hemodynamic instability and end-organ complications. To better understand the cellular effects of cytokine adsorption in patients receiving extracorporeal cardiopulmonary resuscitation (ECPR) after in- and out-of-hospital cardiac arrest, we compared the activation status of neutrophils, monocytes, and platelets as well as the formation of platelet-leukocyte complexes in intravenous whole blood samples from an exploratory subgroup (n = 24) from the randomized CYTER study. At 48 hours after initiation of ECPR, flow cytometry analyses did neither reveal significant differences in neutrophil (CD11b, CD66b, L-selectin, and PSGL-1) and monocyte (CD11b, L-selectin, and PSGL-1) surface molecule expression nor in circulating platelet-monocyte complexes between patients receiving cytokine adsorption and those without. Data did not show a relevant effect of cytokine adsorption on neutrophil and monocyte activation during the first 48 hours after initiation of ECPR.

Fc-gamma receptor expression and cytokine responses to intravenous human immunoglobulin in whole blood from non-pregnant and pregnant women and newborns.

Intravenous immunoglobulin (IVIG) can suppress the inflammatory response in adults, but its role in pregnant women and newborns is poorly studied. While the adult immune system is considered mature, it is immature in neonates and suppressed in pregnancy. Since the immune response differs in these 3 groups, the use of IVIG could differentially modulate the immune response. We aimed to explore the effect of IVIG on myeloid blood cells from non-pregnant women, pregnant women and newborns. Whole blood from healthy donors was incubated with lipopolysaccharide (LPS) and/or IVIG. After 0 h, 24 h and 48 h of culture, Fc-gamma receptor (CD16, CD32 and CD64) expression, monocyte and neutrophil bacterial phagocytosis, and cytokine and chemokine concentrations were determined in the supernatant. The baseline expression of monocyte CD16 was higher in newborns than in adult women, but the expression of CD32 and CD64 was similar between groups. Furthermore, LPS and IVIG stimulation, together or separately, did not change Fc-gamma receptor expression in monocytes or neutrophils and did not modify their phagocytosis capacity. On the other hand, IVIG did not downregulate the proinflammatory cytokine response induced by LPS in any group. Interestingly, IVIG induced a strong interleukin 8 (IL-8) response in neonates but not in non-pregnant or pregnant women. Our results show that IVIG did not induce changes in Fc-gamma receptor expression, phagocytic ability, or the cytokine response to LPS in blood cells from neonates, non-pregnant or pregnant women. However, IVIG induced a strong IL-8 response in neonates that could improve immunity.

C5aR2 Deficiency Lessens C5aR1 Distribution and Expression in Neutrophils and Macrophages.

As another receptor for complement activation product C5a, C5aR2 has been paid much attention these years. Although controversial and complex, its specific signals or roles in modulating the classic receptor C5aR1 have been investigated and gradually revealed. The hypothesis of the heterodimer of C5aR1 and C5aR2 has also been suggested and observed under extremely high C5a concentrations. In this article, we tried to investigate whether C5aR2 would affect C5aR1 expression under normal or inflammatory conditions in WT and C5ar2 -/- mice of C57BL/6 background. We focused on the innate immune cells-neutrophils and macrophages. The mRNA levels of C5ar1 in normal kidney, liver, and the mRNA or protein levels of naïve-bone marrow and peripheral blood leukocytes and peritoneal Mφs were comparable between WT and C5ar2 -/- mice, indicating the technique of C5aR2 knockout did not affect the transcription of its neighboring gene C5aR1. However, the mean fluorescence intensity of surface C5aR1 on naïve circulating C5ar2 -/- neutrophils detected by FACS was reduced, which might be due to the reduced internalization of C5aR1 on C5ar2 -/- neutrophils. In the peritonitis model induced by i.p. injection of thioglycollate, more neutrophils were raised after 10 hr in C5ar2 -/- peritoneal cavity, indicating the antagonism of C5aR2 on C5aR1 signal in neutrophil chemotaxis. After 3 days of thioglycollate injection, the mainly infiltrating macrophages were comparable between WT and C5ar2 -/- mice, but the C5ar1 mRNA and surface or total C5aR1 protein expression were both reduced in C5ar2 -/- macrophages, combined with our previous study of reduced chemokines and cytokines expression in C5ar2 -/- peritoneal macrophages, indicating that C5aR2 in macrophages may cooperate with C5aR1 inflammatory signals. Our article found C5aR2 deficiency lessened C5aR1 distribution and expression in neutrophils and macrophages with different functions, indicating C5aR2 might function differently in different cells.