Neutrophil Gene Research Articles

C5aR1-positive neutrophils promote breast cancer glycolysis through WTAP-dependent m6A methylation of ENO1

Neutrophils are significant compositions of solid tumors and exert distinct functions in different types of tumors. However, the precise role of neutrophils in the progression of breast cancer (BC) is presently unclear. In this study, by investigating the single-cell RNA sequencing data, we identify a new neutrophil subset, C5aR1-positive neutrophils, that correlates with tumor progression and poor survival for BC patients. Furthermore, it is discovered that C5aR1-positive neutrophils enhance BC cell glycolysis via upregulating ENO1 expression. Mechanically, C5aR1-positive neutrophil-secreted IL1β and TNFα cooperatively activate ERK1/2 signaling, which phosphorylates WTAP at serine341 and thereby stabilizes WTAP protein. The stabilization of WTAP further promotes RNA m6A methylation of ENO1, impacting the glycolytic activity of BC cells. Importantly, C5aR1-positive neutrophils also promote breast cancer growth in vivo, and this effect is abolished by WTAP silencing. In clinical BC samples, increased C5aR1-positive neutrophils correlate with elevated IL1β, TNFα, and ENO1 expression. A high co-expression of C5aR1-positive neutrophil gene signature and ENO1 predicts worse prognosis of BC patients compared with a low co-expression. Collectively, our study reveals a novel subset of C5aR1-positive neutrophils that induces breast cancer glycolysis via increasing ERK1/2-WTAP-dependent m6A methylation of ENO1. These findings support the potential for exploration of C5aR1-positive neutrophils as a therapeutic target in breast cancer.

Transient, flexible gene editing in zebrafish neutrophils and macrophages for determination of cell-autonomous functions.

ABSTRACTZebrafish are an important model for studying phagocyte function, but rigorous experimental systems to distinguish whether phagocyte-dependent effects are neutrophil or macrophage specific have been lacking. We have developed and validated transgenic lines that enable superior demonstration of cell-autonomous neutrophil and macrophage genetic requirements. We coupled well-characterized neutrophil- and macrophage-specific Gal4 driver lines with UAS:Cas9 transgenes for selective expression of Cas9 in either neutrophils or macrophages. Efficient gene editing, confirmed by both Sanger and next-generation sequencing, occurred in both lineages following microinjection of efficacious synthetic guide RNAs into zebrafish embryos. In proof-of-principle experiments, we demonstrated molecular and/or functional evidence of on-target gene editing for several genes (mCherry, lamin B receptor, trim33) in either neutrophils or macrophages as intended. These new UAS:Cas9 tools provide an improved resource for assessing individual contributions of neutrophil- and macrophage-expressed genes to the many physiological processes and diseases modelled in zebrafish. Furthermore, this gene-editing functionality can be exploited in any cell lineage for which a lineage-specific Gal4 driver is available.This article has an associated First Person interview with the first author of the paper.

A Comparative Study on Changes in Total and Differential Milk Cell Counts, Activity, and Expression of Milk Phagocytes of Healthy and Mastitic Indigenous Sahiwal Cows.

Milk somatic cell counts (SCCs) have been used as a gold standard to monitor mammary health as well as an indicator of raw milk quality. The present work was undertaken to compare the changes in the milk SCC, milk differential leukocyte counts (DLCs), phagocytic activity (PA) of milk neutrophils and macrophages (by nitroblue tetrazolium assay), extracellular trap formation (PicoGreen assay) and mRNA expression of various genes in milk neutrophils and macrophages (reverse transcription–polymerase chain reaction), and milk plasma cortisol concentration (enzyme-linked immunosorbent assay) in healthy, subclinical mastitis (SCM), and clinical mastitis (CM) cows. Milk was collected from healthy, SCM, and CM cows grouped based on their SCCs and California mastitis test with eight cows in each group. Milk SCC was estimated by SCC counter, and DLC was done after staining the milk slide under a microscope at 100×. Total SCCs in healthy, SCM, and CM cows were on an average of 128.30, 300.3, and 694.40 × 103 cells/mL, respectively. Milk DLCs indicated a lower percentage of macrophage and lymphocytes and a higher (p < 0.05) percentage of neutrophils in SCM and CM compared to healthy milk. The percentage of mature segmented neutrophils was lower, whereas immature band neutrophils were higher (p < 0.05) in the SCM and CM groups as compared to healthy cows. The viability, in vitro PA, and extracellular trap formation of neutrophils were lower (p < 0.05) in SCM and CM milk samples as compared to healthy samples. However, the PA of macrophage remained unchanged in all the studied groups. The relative mRNA expression of Toll-like receptors (TLR2, TLR4), myeloperoxidase, and interleukin 2α (IL-2α) receptor (CD25) were minimum in healthy samples and increased (p < 0.05) with the progress of mammary inflammation. However, CD44 decreased (p < 0.05), and CD62L remained unchanged in mastitis as compared to healthy cows. Plasma cortisol concentrations were higher (p < 0.05) in mastitis as compared to healthy cows and were negatively correlated with the number of milk macrophages and the functions of milk phagocytes. Estimation of total SCC, milk DLC, and activity of milk phagocytes is essential for effective control and prevention of incidence of mastitis in dairy cows.

Transcriptomics of type 2 diabetic and healthy human neutrophils

ObjectivesChronic inflammatory diseases, including diabetes and cardiovascular disease, are heterogeneous and often co-morbid, with increasing global prevalence. Uncontrolled type 2 diabetes (T2D) can result in severe inflammatory complications. As neutrophils are essential to normal and aberrant inflammation, we conducted RNA-seq transcriptomic analyses to investigate the association between neutrophil gene expression and T2D phenotype. As specialized pro-resolving lipid mediators (SPM) act to resolve inflammation, we further surveyed the impact of neutrophil receptor binding SPM resolvin E1 (RvE1) on isolated diabetic and healthy neutrophils.MethodsCell isolation and RNA-seq analysis of neutrophils from N = 11 T2D and N = 7 healthy individuals with available clinical data was conducted. Additionally, cultured neutrophils (N = 3 T2D, N = 3 healthy) were perturbed with increasing RvE1 doses (0 nM, 1 nM, 10 nM, or 100 nM) prior to RNA-seq. Data was evaluated through a bioinformatics pipeline including pathway analysis and post hoc false discovery rate (FDR)-correction.ResultsWe observed significant differential expression of 50 genes between T2D and healthy neutrophils (p < 0.05), including decreased T2D gene expression in inflammatory- and lipid-related genes SLC9A4, NECTIN2, and PLPP3 (p < 0.003). RvE1 treatment induced dose-dependent differential gene expression (uncorrected p < 0.05) across groups, including 59 healthy and 216 T2D neutrophil genes. Comparing T2D to healthy neutrophils, 1097 genes were differentially expressed across RvE1 doses, including two significant genes, LILRB5 and AKR1C1, involved in inflammation (p < 0.05).ConclusionsThe neutrophil transcriptomic database revealed novel chronic inflammatory- and lipid-related genes that were differentially expressed between T2D cells when compared to controls, and cells responded to RvE1 dose-dependently by gene expression changes. Unraveling the mechanisms regulating abnormalities in diabetic neutrophil responses could lead to better diagnostics and therapeutics targeting inflammation and inflammation resolution.

Sanguisorba parviflora (Maxim.) Takeda alleviates cyclophosphamide-induced leukopenia by regulating haematopoietic cell-specific protein 1-associated protein X-1 gene expression.

We have previously shown that the saponins of Sanguisorba parviflora (Maxim.) Takeda (Sp. T) relieved cyclophosphamide-induced myelosuppression in leukopenic mice. Haematopoietic cell-specific protein 1-associated protein X-1 (HAX-1) participated in the survival of neutrophils through the regulation of mitochondrial function. The aim of the present study was to comprehensively identify the role of HAX-1 in the mechanism of leukopenia alleviation by Sp.T. HAX-1gene and protein expression levels in peripheral blood neutrophils were examined using real-time quantitative reverse transcription-polymerase chain reaction, western blot and immunohistochemical assays. Neutrophil apoptosis was measured using flow cytometry. Mitochondrial function was determined via assessments of the reactive oxygen species (ROS) generation and mitochondrial membrane potential (ΔΨm) integrity levels. The HAX-1gene expression level in the peripheral blood neutrophils was significantly lower in patients with leukopenia than in healthy donors. The saponins of Sp.T induced HAX-1 expression and promoted myeloid progenitor cell (mEB8-ER cell) viability. HAX-1 overexpression reduced the production of ROS and maintained ΔΨm integrity. Cyclophosphamide-induced mitochondrial dysfunction and apoptosis could be abrogated by treatment with Sp.T or metformin. Our data suggest a mechanism through which Sp.T protects against chemotherapy-induced leukopenia by regulating HAX-1gene expression in a mitochondrial-dependent manner.

Involvement of Neutrophils in Metastatic Evolution of Pancreatic Neuroendocrine Tumors.

Simple SummaryThe neutrophil-to-lymphocytes (NLR) reflects the systemic inflammation. Based on a cohort of 144 patients treated for localized or metastatic well-differentiated pancreatic neuroendocrine tumors (pNET), we identified the NLR ≥ 4 to be associated with worse overall survival. Using MCP-Counter on a publicly available pNET RNA-sequencing dataset, we inferred the tumor microenvironment composition of 83 primary pNET and 30 liver metastasis. The neutrophils scores were statistically higher in liver metastasis relative to primary pancreatic tumors (p = 0.005). Gene set enrichment analysis further revealed activation of complement pathway signature in liver metastasis. Through combination of the neutrophil and complement pathway genes, we found that pNET can be classified into two clusters: Neu-Comp1 and Neu-Comp2. Notably, the Neu-Compt1 cluster was enriched in neutrophils and complement pathway signatures and was associated with liver metastasis. These data offer new insights into the role of inflammatory factors in the metastatic progression of the pNET.Well-differentiated pancreatic neuroendocrine tumors (pNET) have an unpredictable natural history. The identification of both blood and tumor immune features associated with patients’ outcomes remains limited. Herein, we evaluated the best prognostic value of the neutrophils-to-lymphocyte ratio (NLR) in a cohort of 144 pNETs. The NLR ≥ 4 was associated with worse overall survival in both univariate analysis (HR = 3.53, CI95% = 1.50–8.31, p = 0.004) and multivariate analysis (HR = 2.57, CI95% = 1.061–6.216, p = 0.036). The presence of synchronous liver metastasis was identified as a prognostic factor in multivariate analysis (HR = 3.35, CI95% = 1.411–7.973, p = 0.006). Interestingly, the absolute tumor-associated neutrophils count was higher in liver metastasis as compared to their paired primary tumor (p = 0.048). Deconvolution of immune cells from the transcriptome of 83 primary tumors and 30 liver metastases reveals enrichment for neutrophils in metastasis relative to primary tumors (p = 0.005), and this was associated with upregulation of the complement pathway (NES = 1.84, p < 0.0001). Combining neutrophils signature and complement pathway genes, unsupervised clustering identified two pNETs subgroups, namely Neu-Comp1 and Neu-Comp2. Characterized by neutrophils infiltration and activation of the complement pathway, Neu-Comp1 was highly enriched for metastatic liver samples as compared to Neu-Comp2 (p < 0.0001). These data suggest the possible link between liver metastasis, complement pathway activation, and neutrophils infiltration in well-differentiated pNET and open avenues for targeting complement pathways in these tumors.

The relationship between cytokine and neutrophil gene network distinguishes SARS-CoV-2-infected patients by sex and age.

The fact that the COVID-19 fatality rate varies by sex and age is poorly understood. Notably, the outcome of SARS-CoV-2 infections mostly depends on the control of cytokine storm and the increasingly recognized pathological role of uncontrolled neutrophil activation. Here, we used an integrative approach with publicly available RNA-Seq data sets of nasopharyngeal swabs and peripheral blood leukocytes from patients with SARS-CoV-2, according to sex and age. Female and young patients infected by SARS-CoV-2 exhibited a larger number of differentially expressed genes (DEGs) compared with male and elderly patients, indicating a stronger immune modulation. Among them, we found an association between upregulated cytokine/chemokine- and downregulated neutrophil-related DEGs. This was correlated with a closer relationship between female and young subjects, while the relationship between male and elderly patients was closer still. The association between these cytokine/chemokines and neutrophil DEGs is marked by a strongly correlated interferome network. Here, female patients exhibited reduced transcriptional levels of key proinflammatory/neutrophil-related genes, such as CXCL8 receptors (CXCR1 and CXCR2), IL-1β, S100A9, ITGAM, and DBNL, compared with male patients. These genes are well known to be protective against inflammatory damage. Therefore, our work suggests specific immune-regulatory pathways associated with sex and age of patients infected with SARS-CoV-2 and provides a possible association between inverse modulation of cytokine/chemokine and neutrophil transcriptional signatures.

Integrative profiling of chromatin accessibility and gene expression elucidate specific transcriptional network in porcine neutrophils

Abstract Pigs are an important component of global food security, and serve as a human biomedical model. Infectious diseases impact pig and human health and global food productivity. Components of the pig innate immune system, such as neutrophils, have not been fully described, and epigenetic mechanisms controlling gene expression remain unclear in pigs. We performed RNA- and assay for transposase-accessible chromatin (ATAC)-sequencing on two porcine neutrophil samples to characterize epigenetic regulation of gene expression in these differentiated cells. A deep neutrophil transcriptome detected expression of 10,974 genes. In comparison to previously reported RNA-seq data on eight sorted immune cell types from the same animals, we predicted 833 enriched (significantly higher and 2-fold higher than average across all other cell types) genes in neutrophils. The 833 gene list was significantly enriched for biological processes related to typical neutrophil functions using Gene Ontology and in comparison to human neutrophil RNA-seq data. ATAC-seq detected open chromatin (OP) regions from ~227 million total reads that identified on average 151,789 peaks located in intergenic (67%), intron (24%), promoter-TSS (6%), exon (3%) or TTS (1%) regions. OP regions whose signal is correlated with, and nearby to, genes with enriched neutrophil expression are being analyzed for sites predicted to be bound by transcription factors that could explain neutrophil-enriched expression patterns. The data reported here is the first integrative study of the epigenetics of porcine neutrophil gene expression and provide a valuable resource to elucidate neutrophil transcriptional regulatory networks.

P145 Computational analysis of neutrophil gene expression reveals activation signatures associated with DMARD refractory rheumatoid arthritis

Abstract Background/Aims Neutrophils contribute to disease pathology in inflammatory diseases including rheumatoid arthritis (RA). Activated RA neutrophils release ROS and proteases which damage joints, and produce neutrophil extracellular traps (NETs) that expose citrullinated nuclear proteins leading to the development of ACPA auto-antibodies. We previously described an altered gene expression signature in RA patients compared to healthy controls. This aim of this work was to use computational modelling of neutrophil transcriptomes to provide novel insight into the physiological factors controlling neutrophil phenotype in RA. Methods RNA from peripheral blood neutrophils (RA patients (DAS28&amp;gt;5.1, cohort 1 n = 23, cohort 2 n = 53), healthy controls (n = 11)) was sequenced using RNAseq. Reads were mapped to the human genome (hg38) using Tophat2 and read counts generated using featureCounts. Partial least squares discriminant analysis (PLS-DA) was carried out using mixOmics (with random sampling and ‘leave one out’ cross-validation). Gene expression network analysis was carried out using tmod, ARACNE2 and GALGO. Gene networks were visualised using Cytoscape. Functional annotation was carried out using Ingenuity Pathway Analysis (IPA) and DAVID. Results PLS-DA modelling discriminated RA and HC neutrophil transcriptomes with an F1 score of 98.2% +/- 1.6% over 5 repetitions using a model with 1 component. Blood transcriptional modular (tmod) enrichment analysis of gene expression in RA and HC neutrophils from cohort 1 identified the gene networks activated in RA and absent in HC as: myeloid cells activated via NFκB, innate antiviral response, type I interferon response, inflammasome receptors and cell signalling (FDR&amp;lt;0.05, AUC &amp;gt;0.8). Cell cycle and growth arrest was also considerably more enriched in RA compared to HC (RA AUC=0.82, HC AUC=0.57). Activation of type I interferon and inflammasome signalling pathways in cohort 1 was confirmed by IPA and correlated closely with data from a second cohort of RA patients (cohort 2). ARACNE2 identified five major gene modules activated in RA neutrophils (MI threshold 0.5, p &amp;lt; 10-20). IPA and DAVID predicted that Module 1 gene networks regulated amino acid, nucleic acid, carbohydrate and lipid metabolism as well as initiation of gene expression. Module M2 contained a network of genes regulated by integrins and cytokine receptors (e.g. IL-8, JAK/STAT, TNF/NFκB). Module 3 also contained genes activated by NFκB as well as by AMP-protein kinase. Module M4 genes were regulated by activation of type I interferon receptors and pattern recognition receptors (e.g. IRFs, STATs). Module M5 genes regulated amino acid metabolism. Multivariate modelling using GALGO identified genes that predict clinical characteristics, including genes involved in NFκB signalling, apoptosis and kinase activation which were associated with disease activity (DAS28), and cellular stress response genes and chromatin modification that was associated with raised inflammatory markers (ESR, CRP). Conclusion The results of the computational analyses are currently being validated experimentally. Disclosure M. Fresneda Alarcon: None. E. Caamano-Gutierrez: None. P. Antczak: None. R.J. Moots: None. H.L. Wright: Grants/research support; H.W. has received funding from Versus Arthritis and the Masonic Charitable Fund.

A robust and flexible CRISPR/Cas9-based system for neutrophil-specific gene inactivation in zebrafish.

CRISPR/Cas9-based tissue-specific knockout techniques are essential for probing the functions of genes in embryonic development and disease using zebrafish. However, the lack of capacity to perform gene-specific rescue or live imaging in the tissue-specific knockout background has limited the utility of this approach. Here, we report a robust and flexible gateway system for tissue-specific gene inactivation in neutrophils. Using a transgenic fish line with neutrophil-restricted expression of Cas9 and ubiquitous expression of single guide (sg)RNAs targeting rac2, specific disruption of the rac2 gene in neutrophils is achieved. Transient expression of sgRNAs targeting rac2 or cdk2 in the neutrophil-restricted Cas9 line also results in significantly decreased cell motility. Re-expressing sgRNA-resistant rac2 or cdk2 genes restores neutrophil motility in the corresponding knockout background. Moreover, active Rac and force-bearing F-actins localize to both the cell front and the contracting tail during neutrophil interstitial migration in an oscillating fashion that is disrupted when rac2 is knocked out. Together, our work provides a potent tool that can be used to advance the utility of zebrafish in identifying and characterizing gene functions in a tissue-specific manner.

NNOS induction and NOSIP interaction impact granulopoiesis and neutrophil differentiation by modulating nitric oxide generation

Nitric oxide (NO), a versatile free radical and a signalling molecule, plays an important role in the haematopoiesis, inflammation and infection. Impaired proliferation and differentiation of myeloid cells lead to malignancies and Hematopoietic deficiencies. This study was aimed to define the role of nNOS derived NO in neutrophil differentiation (in-vitro) and granulopoiesis (in-vivo) using multipronged approaches. The results obtained from nNOS over-expressing K562 cells revealed induction in C/EBPα derived neutrophil differentiation as evident by an increase in the expression of neutrophil specific cell surface markers, genes, transcription factors and functionality. nNOS mediated response also involved G-CSFR-STAT-3 axis during differentiation. Consistent increase in NO generation was observed during neutrophil differentiation of mice and human CD34+ HSPCs. Furthermore, granulopoiesis was abrogated in the nNOS inhibitor treated mice, depicting a decrease in the numbers of BM mature and progenitor neutrophils. Likewise, in vitro inhibition of nNOS in human CD34+ HSPCs indicated an indispensable role of nNOS in neutrophil differentiation. Expression of nNOS inhibitory protein, NOSIP was significantly and consistently decreased during the final stage of differentiation and was linked with the augmentation in NO release. Moreover, neutrophils from CML patients had more NOSIP and less NO generation as compared to the PMNs from healthy individuals. The present study thus indicates a critical role of nNOS, and its interaction with NOSIP during neutrophil differentiation. The study also highlights the importance of nNOS in the neutrophil progenitor proliferation and differentiation warranting investigations to assess its role in the haematopoiesis-related disorders.

Identifying the most influential gene expression profile in distinguishing ANCA-associated vasculitis from healthy controls

Previous gene expression analyses seeking genes specific to antineutrophil cytoplasmic antibody-associated vasculitis (AAV) have been limited due to crude cell separation and the use of microarrays. This study aims to identify AAV-specific gene expression profiles in a way that overcomes those limitations. Blood samples were collected from 26 AAV patients and 28 healthy controls (HCs). Neutrophils were isolated by negative selection, whereas 19 subsets of peripheral blood mononuclear cells were sorted by fluorescence assisted cell sorting. RNA-sequencing was then conducted for each sample, and iterative weighted gene correlation network analysis (iterativeWGCNA) and random forest were consecutively applied to identify the most influential gene module in distinguishing AAV from HCs. Correlations of the identified module with clinical parameters were evaluated, and the biological role was assessed with hub gene identification and pathway analysis. Particularly, the module's association with neutrophil extracellular trap formation, NETosis, was analyzed. Finally, the module's overlap with GWAS-identified autoimmune disease genes (GADGs) was assessed for validation. A neutrophil module (Neu_M20) was ranked top in the random forest analysis among 255 modules created by iterativeWGCNA. Neu_M20 correlated with disease activity and neutrophil counts but not with the presence of antineutrophil cytoplasmic antibody. The module comprised pro-inflammatory genes, including those related to NETosis, supported by experimental evidence. The genes in the module significantly overlapped GADGs. We identified the distinct group of pro-inflammatory genes in neutrophils, which characterize AAV. Further investigations are warranted to confirm our findings as they could serve as novel therapeutic targets.

Molecular and Cellular Biomarkers of COVID-19 Prognosis: Protocol for the Prospective Cohort TARGET Study.

BackgroundSince the beginning of the COVID-19 pandemic, the world’s attention has been focused on better understanding the relation between the human host and the SARS-CoV-2 virus, as its action has led to hundreds of thousands of deaths.ObjectiveIn this context, we decided to study certain consequences of the abundant cytokine release over the innate and adaptive immune systems, inflammation, and hemostasis, comparing mild and severe forms of COVID-19.MethodsTo accomplish these aims, we will analyze demographic characteristics, biochemical tests, immune biomarkers, leukocyte phenotyping, immunoglobulin profile, hormonal release (cortisol and prolactin), gene expression, thromboelastometry, neutralizing antibodies, metabolic profile, and neutrophil function (reactive oxygen species production, neutrophil extracellular trap production, phagocytosis, migration, gene expression, and proteomics). A total of 200 reverse transcription polymerase chain reaction–confirmed patients will be enrolled and divided into two groups: mild/moderate or severe/critical forms of COVID-19. Blood samples will be collected at different times: at inclusion and after 9 and 18 days, with an additional 3-day sample for severe patients. We believe that this information will provide more knowledge for future studies that will provide more robust and useful clinical information that may allow for better decisions at the front lines of health care.ResultsThe recruitment began in June 2020 and is still in progress. It is expected to continue until February 2021. Data analysis is scheduled to start after all data have been collected. The coagulation study branch is complete and is already in the analysis phase.ConclusionsThis study is original in terms of the different parameters analyzed in the same sample of patients with COVID-19. The project, which is currently in the data collection phase, was approved by the Brazilian Committee of Ethics in Human Research (CAAE 30846920.7.0000.0008).Trial RegistrationBrazilian Registry of Clinical Trials RBR-62zdkk; https://ensaiosclinicos.gov.br/rg/RBR-62zdkkInternational Registered Report Identifier (IRRID)DERR1-10.2196/24211

The effect of equine bone marrow-derived mesenchymal stem cells on the expression of apoptotic genes in neutrophils.

BackgroundBone marrow mesenchymal stem cells (BM‐MSCs), as multipotent cells with self‐renewal and plastic‐adherent properties, have immunomodulatory effects on immune cells, including neutrophils. These cells are in close proximity in bone marrow (BM) sinusoids with non‐multiplicative immature neutrophils. BM‐MSCs exert their immunomodulatory effects on adjacent cells both directly (cell‐to‐cell contact) and indirectly (secretion of soluble factors).ObjectivesThe aim of this study was to evaluate the effect of equine bone marrow mesenchymal stem cells (BM‐MSCs) on the expression of some pro‐ and anti‐apoptotic genes (p53, survivin and Bcl2) in neutrophils co‐cultured with BM‐MSCs.MethodsFor this purpose, peripheral blood neutrophils were isolated and separately co‐cultured for 12 hr with both BM‐MSCs and the BM‐MSCs΄ supernatant. Four groups were included: neutrophils with only culture media (as control), neutrophils co‐cultured with BM‐MScs, neutrophils cultured with BM‐MSCs’ supernatant and neutrophils cultured with lipopolysaccharide (LPS, as positive control). Then, the expression of mentioned genes (p53, survivin and Bcl2) was evaluated by quantitative polymerase chain reaction (qPCR).ResultsCompared with control neutrophils, in neutrophils co‐cultured with both BM‐MSCs and BM‐MSCs’ supernatant, the mRNA expression levels of p53, as pro‐apoptotic gene, and survivin and Bcl2, as anti‐apoptotic genes, were remarkably increased and decreased (p < .05), respectively.ConclusionsThese data revealed the notion that the direct contact of BM‐MSCs is not obligatory for their effects on the apoptotic status of neutrophils and they affect neutrophils via soluble secreted factors, which is promising for clinical implications in equine medicine.

Tumor-Infiltrating Neutrophils and Non-Classical Monocytes May Be Potential Therapeutic Targets for HER2negative Gastric Cancer.

Gastric cancer (GC) is the fourth most common cause of cancer-related death globally. The classification of advanced GC (AGC) according to molecular features has recently led to effective personalized cancer therapy for some patients. Specifically, AGC patients whose tumor cells express high levels of human epidermal growth factor receptor 2 (HER2) can now benefit from trastuzumab, a humanized monoclonal Ab that targets HER2. However, patients with HER2negative AGC receive limited clinical benefit from this treatment. To identify potential immune therapeutic targets in HER2negative AGC, we obtained 40 fresh AGC specimens immediately after surgical resections and subjected the CD45+ immune cells in the tumor microenvironment to multi-channel/multi-panel flow cytometry analysis. Here, we report that HER2 negativity associated with reduced overall survival (OS) and greater tumor infiltration with neutrophils and non-classical monocytes. The potential pro-tumoral activities of these cell types were confirmed by the fact that high expression of neutrophil or non-classical monocyte signature genes in the gastrointestinal tumors in The Cancer Genome Atlas, Genotype-Tissue Expression and Gene Expression Omnibus databases associated with worse OS on Kaplan-Meir plots relative to tumors with low expression of these signature genes. Moreover, advanced stage disease in the AGCs of our patients associated with greater tumor frequencies of neutrophils and non-classical monocytes than early stage disease. Thus, our study suggests that these 2 myeloid populations may serve as novel therapeutic targets for HER2negative AGC.

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We are very grateful for the interest in our manuscript describing synovial histology features that associate with patient reports of morning stiffness in rheumatoid arthritis(RA)1 . Pamuk et al. note that neutrophil gene and protein expression, as well as cell counts, fluctuate in the blood in a 24-hour circadian cycle and the circadian variation in neutrophil function may contribute to morning stiffness.

JAGN1 mutations in severe congenital neutropenia.

Severe congenital neutropenia (SCN) was first clinically described in 1956 by Swedish pediatrician Rolf Kostmann, who recognized that infants who suffered from severe bacterial infections with absolute neutrophil counts (ANC) persistently below 0.5 × 109/l represented an inherited genetic disorder.1 SCN is now known to be caused by mutations in at least 25 genes and has autosomal recessive (AR), autosomal dominant (AD) and X-linked forms.2 The most common cause is due to AD mutations in the neutrophil elastase gene, ELANE, while the original disease Kostmann described was found to be due to AR mutations in HAX1.3, 4 Many of the genes causing SCN appear to be involved in endoplasmic reticulum (ER) or mitochondrial function and their disruption is involved in increasing ER stress and enhancing neutrophil apoptosis. In this issue the paper by Khandagale et al.5 whole exome sequencing techniques were applied to 27 AR SCN patients and three were found to have homozygous mutations in jagunal homolog 1 (JAGN1) which was first described as a cause of SCN in 2014 by Boztug et al.6 Jagunal was originally described as being critical for oocyte development in Drosophila via its role in ER reorganization.7 This new study further enhances our knowledge of how JAGN1 mutations can lead to ER stress and intracellular calcium activation of calpain that leads to apoptosis of myeloid cells. The experiments reported here utilized patient neutrophils, human bone marrow and the HL-60 cell line (derived from a human acute promyelocytic leukemia) to demonstrate aberrant neutrophil granules and a predilection to higher cytosolic calcium upon stimulation and enhanced calpain-dependent apoptosis in the presence of the mutant JAGN1 which could be blocked by addition of a specific inhibitor (PD150606) or by silencing JAGN1. It is of note that knocking down JAGN1 with small interfering (si)-RNA did not affect susceptibility of HL-60 cells to cell death, suggesting a dominant pathophysiologic effect of patient mutant JAGN1 on a calpain-mediated process despite an autosomal recessive pattern of inheritance. Khandagale et al. have achieved a very important breakthrough in understanding how JAGN1 mutations promote a non-apoptotic, calpain-dependent form of cell death. The authors acknowledge that further work will be needed to fully understand this pathway. The mainstay of treatment for SCN has been filgrastim since its approval by the FDA in 1991.8 It is a recombinant human granulocyte-stimulating factor that must be injected. While improving quality of life and survival by enhancing numbers and function of neutrophils in most types of SCN, long-term use has been associated with patients being at increasing risk of clonal myeloid disorders and malignancies.9 Whether this is a direct toxicity or due to prolonged survival of the patients allowing evolution of malignant clones from the prolonged pathophysiologic stress from effects of the underlying mutation remains controversial. Other experimental treatments may be appropriate in carefully selected SCN patients such as small-molecule CXCR4 inhibitors such as plerixafor or mavorixafor for WHIM syndrome,10 empagliflozin for G6PT deficiency,11 and perhaps neutrophil elastase inhibitors such as alvelestat for ELANE mutations or JAGN1 inhibitors for mutant JAGN1. Bone marrow transplantation can cure SCN, but is limited by the availability of suitable donors, and is associated with the risk of graft-versus-host disease, infectious mortality and other complications which will be improved by utilizing more specific conditioning regimens.12 Donor availability has been made less of a concern since haploidentical transplant has become more common. Genetic correction of neutrophil gene defects has already been successfully undertaken13 and may be even more practical in the future. In AD SCN, recent evidence suggests deletion of the disease allele may be a simple and effective technique without need to specifically correct the gene defect. In the case of WHIM syndrome, evidence suggests that removal of one copy of CXCR4 enhances haematopoietic stem cell engraftment and survival without the need for conditioning.14 Similarly, editing and removal of ELANE may be curative in the future.15

Virulence of the Pathogen Porphyromonas gingivalis Is Controlled by the CRISPR-Cas Protein Cas3.

The CRISPR (clustered regularly interspaced short palindromic repeat)-Cas system is a unique genomic entity that provides prokaryotic cells with adaptive and heritable immunity. Initial studies identified CRISPRs as central elements used by bacteria to protect against foreign nucleic acids; however, emerging evidence points to CRISPR involvement in bacterial virulence. The present study aimed to identify the participation of one CRISPR-Cas protein, Cas3, in the virulence of the oral pathogen Porphyromonas gingivalis, an organism highly associated with periodontitis. Our results show that compared to the wild type, a mutant with a deletion of the Cas3 gene, an essential nuclease part of the class 1 type I CRISPR-Cas system, increased the virulence of P. gingivalis In vitro infection modeling revealed only mildly enhanced production of proinflammatory cytokines by THP-1 cells when infected with the mutant strain. Dual transcriptome sequencing (RNA-seq) analysis of infected THP-1 cells showed an increase in expression of genes associated with pathogenesis in response to Δcas3 mutant infection, with the target of Cas3 activities in neutrophil chemotaxis and gene silencing. The importance of cas3 in controlling virulence was corroborated in a Galleria mellonella infection model, where the presence of the Δcas3 mutant resulted in a statistically significant increase in mortality of G. mellonella A time-series analysis of transcription patterning during infection showed that G. mellonella elicited very different immune responses to the wild-type and the Δcas3 mutant strains and revealed a rearrangement of association in coexpression networks. Together, these observations show for the first time that Cas3 plays a significant role in regulating the virulence of P. gingivalis IMPORTANCE Porphyromonas gingivalis is a key pathogen of periodontitis, a polymicrobial disease characterized by a chronic inflammation that destroys the tissues supporting the teeth. Thus, understanding the virulence potential of P. gingivalis is essential to maintaining a healthy oral microbiome. In nonoral organisms, CRISPR-Cas systems have been shown to modulate a variety of microbial processes, including protection from exogenous nucleic acids, and, more recently, have been implicated in bacterial virulence. Previously, our clinical findings identified activation of the CRISPR-Cas system in patient samples at the transition to disease; however, the mechanism of contribution to disease remained unknown. The importance of the present study resides in that it is becoming increasingly clear that CRISPR-associated proteins have broader functions than initially thought and that those functions now include their role in the virulence of periodontal pathogens. Studying a P. gingivalis cas3 mutant, we demonstrate that at least one of the CRISPR-Cas systems is involved in the regulation of virulence during infection.

Distinct peripheral blood monocyte and neutrophil transcriptional programs following intracerebral hemorrhage and different etiologies of ischemic stroke

Understanding cell-specific transcriptome responses following intracerebral hemorrhage (ICH) and ischemic stroke (IS) will improve knowledge of the immune response to brain injury. Transcriptomic profiles of 141 samples from 48 subjects with ICH, different IS etiologies, and vascular risk factor controls were characterized using RNA-seq in isolated neutrophils, monocytes and whole blood. In both IS and ICH, monocyte genes were down-regulated, whereas neutrophil gene expression changes were generally up-regulated. The monocyte down-regulated response to ICH included innate, adaptive immune, dendritic, NK cell and atherosclerosis signaling. Neutrophil responses to ICH included tRNA charging, mitochondrial dysfunction, and ER stress pathways. Common monocyte and neutrophil responses to ICH included interferon signaling, neuroinflammation, death receptor signaling, and NFAT pathways. Suppressed monocyte responses to IS included interferon and dendritic cell maturation signaling, phagosome formation, and IL-15 signaling. Activated neutrophil responses to IS included oxidative phosphorylation, mTOR, BMP, growth factor signaling, and calpain proteases-mediated blood–brain barrier (BBB) dysfunction. Common monocyte and neutrophil responses to IS included JAK1, JAK3, STAT3, and thrombopoietin signaling. Cell-type and cause-specific approaches will assist the search for future IS and ICH biomarkers and treatments.

The Expression Profile of mRNA and tRNA Genes in Splenocytes and Neutrophils after In Vivo Delivery of Antitumor Short Hairpin RNA of Indoleamine 2,3- Dioxygenase.

RNA-based therapeutics are considered as novel treatments for human diseases. Our previous study demonstrated that treatment with short-hairpin RNA against Ido1 (IDO shRNA) suppresses tumor growth, detects Th1-bias immune responses, and elevates expression of tryptophan transfer RNA (tRNATrp) in total splenocytes. In addition, depletion of Ly6g+ neutrophils attenuates the effect of IDO shRNA. The aim of this study was to investigate the regulatory network and the expression profile of tRNAs and other non-coding RNAs in IDO shRNA-treated spleens. The total splenocytes and magnetic bead-enriched splenic neutrophils were collected from the lung tumor bearing mice, which were treated with IDO shRNA or scramble IDO shRNA, and the collected cells were subsequently subjected to RNA sequencing. The gene ontology analysis revealed the different enrichment pathways in total splenocytes and splenic neutrophils. Furthermore, the expression of tRNA genes was identified and validated. Six isoacceptors of tRNA, with different expression patterns between total splenocytes and splenic neutrophils, were observed. In summary, our findings not only revealed novel biological processes in IDO shRNA-treated total splenocytes and splenic neutrophils, but the identified tRNAs and other non-coding RNAs may contribute to developing a novel biomarker gene set for evaluating the clinical efficiency of RNA-based cancer immunotherapies.