Neutrophil Maturity in Cancer

Effect of MisMatch repair deficiency on metastasis occurrence in a syngeneic mouse model

Mismatch repair deficiency leads to high mutation rates and microsatellite instability (MSI-H), associated with immune infiltration and responsiveness to immunotherapies. In early stages, MSI-H tumors generally have a better prognosis and lower metastatic potential than microsatellite-stable (MSS) tumors, especially in colorectal cancer. However, in advanced stages, MSI-H tumors lose this survival advantage for reasons that remain unclear. We developed a syngeneic mouse model of MSI cancer by knocking out the MMR gene Msh2 in the metastatic 4T1 breast cancer cell line. This model mirrored genomic features of MSI-H cancers and showed reduction in metastatic incidence compared to their MSS counterparts. In MSI-H tumors, we observed an enrichment of immune gene-signatures that negatively correlated with metastasis incidence. A hybrid epithelial-mesenchymal signature, related to aggressiveness was detected only in metastatic MSI-H tumors. Interestingly, we identified immature myeloid cells at primary and metastatic sites in MSI-H tumor-bearing mice, suggesting that MMR deficiency elicits specific immune responses beyond T-cell activation.

The prognostic value of pretreatment neutrophil-lymphocyte ratio and platelet-lymphocyte ratio in patients with esophageal cancer undergoing immunotherapy: a systematic review and meta-analysis

Background

Esophageal cancer (EC) is associated with a high morbidity and mortality rate. Immunotherapy has demonstrated effective antitumor activity in patients with EC, making it imperative to investigate easily accessible prognostic factors. Consequently, we conducted a meta-analysis to explore the prognostic significance of neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) in EC patients treated with immunotherapy.

Methods

The literature search was conducted across three databases: PubMed, Embase, and Web of Science. The primary deadline for literature retrieval was July 2024. Hazard ratio (HR) with a 95% confidence interval (CI) was utilized to assess the association between NLR or PLR and overall survival (OS) as well as progression-free survival (PFS). Statistical analysis was performed using Review Manager version 5.4 and STATA version 15.0.

Results

The meta-analysis included a total of 16 studies involving 1,481 patients. The results indicated a significant correlation between high pretreatment NLR and poor PFS (HR=1.76, 95%CI:1.38-2.25, p<0.001) as well as poor OS (HR=2.61,95%CI:1.86-3.67, p<0.001). Subgroup analyses based on tumor stage revealed that the association between elevated NLR and poor PFS was only observed in advanced EC patients. Regarding PLR, an increased PLR was found to be indicative of inferior PFS (HR=1.44, 95%CI: 1.20-1.72, p<0.001) and OS (HR=1.72,95%CI:1.08-2.74, p=0.020). However, the sensitivity analyses suggested that the observed increase in PLR lack robustness in terms of its impact on inferior OS.

Conclusion

Elevated NLR and PLR are associated with inferior PFS and OS in EC patients receiving immunotherapy. These findings suggest that NLR and PLR levels hold promise as prognostic biomarkers in clinical practice, offering valuable guidance for personalized immunotherapy strategies.

Systematic Review Registration

PROSPERO https://www.crd.york.ac.uk/prospero/, identifier CRD42024596737.

Sex-dependent modulation of caerulein-induced acute pancreatitis in C57BL/6J mice

Acute pancreatitis (AP) is a life-threatening condition, with a higher mortality rate in men than women and in which estrogens might play a protective role. This study aimed to investigate sex-dependent differences in a mouse model of caerulein-induced AP. Thirty-six C57BL/6J mice (19 females and 17 males) were treated intraperitoneally with phosphate-buffered saline or caerulein, and sacrificed 12 hours, 2 days, or 7 days after the last injection. Blood was collected for amylase, lipase, and glucose determination. Severity and extent of inflammation, apoptosis, and acinar to ductal metaplasia (ADM) in pancreatic tissue were scored histologically and total macrophages, major histocompatibility complex (MHC)-II+ cells, M2 macrophages, T and B cells, neutrophils, apoptosis, and ADM were marked immunohistochemically and quantified by digital image analysis. Serum amylase had a peak at 12 hours, without differences between the sexes. In females, pancreatitis reached a peak at 12 hours with a fast recovery while, in males, the peak was delayed to day 2 with residual apoptosis still present. Macrophages were the main inflammatory cell population, followed by T cells, B cells and neutrophils, without differences between sexes. In males, CD206+ cells and apoptosis were higher at both days 2 and 7, and cytokeratin-19+ (CK19+) ADM was higher at day 7 compared with females. The results of this study revealed a faster onset and resolution of caerulein-induced AP in female mice compared with male mice, supporting a sex-dependent modulation of acute pancreatitis.

Activated neutrophils: A next generation cellular immunotherapy

Cell therapies are at the forefront of novel therapeutics. Neutrophils, despite being the most populous immune cells in human blood circulation, are not considered a viable option for cellular therapies because of their short lifespan and poor understanding of their role in the pathophysiology of various diseases. In inflammatory conditions, neutrophils exhibit an activated phenotype. Activation brings about significant changes to neutrophil biology such as increased lifespan, inflammatory cytokine secretion, and enhanced effector functions. Activated neutrophils also possess the potential to stimulate the downstream immune response and are described as essential effectors in the immune response to tumors. This makes activated neutrophils an interesting candidate for cell therapies. Here, we review the biology of activated neutrophils in detail. We discuss the different ways neutrophils can be activated and the effect they have on other immune cells for stimulation of downstream immune response. We review the conditions where activated neutrophil therapy can be therapeutically beneficial and discuss the challenges associated with their eventual translation. Overall, this review summarizes the current state of understanding of neutrophil-based immunotherapies and their clinical potential.

Cryoablation of primary breast cancer tumors induces a systemic abscopal effect altering TIME (Tumor Immune Microenvironment) in distant tumors

Introduction

Despite recent advances, triple-negative breast cancer (TNBC) patients remain at high risk for recurrence and metastasis, which creates the need for innovative therapeutic approaches to improve patient outcomes. Cryoablation is a promising, less invasive alternative to surgical resection, capable of inducing tumor necrosis via freeze/thaw cycles. Necrotic cell death results in increased inflammatory signals and release of preserved tumor antigens, which have the potential to boost the local and systemic anti-tumor immune response. Thus, compared to surgery, cryoablation enhances the activation of T cells leading to an improved abscopal effect, defined as the occurrence of a systemic response after local treatment. We previously showed with a bilateral-tumor mouse model of TNBC that cryoablation of the primary tumor leads to increased infiltration of distant (abscopal) tumors by tumor infiltrating lymphocytes (TILs) and decreased rates of recurrence and metastasis. However, the early drivers of the cryoablation generated abscopal effect are still unknown and knowledge of the mechanism could provide insight into improving the anti-tumor immune response through pharmacologic immune modulation in addition to cryoablation.

Methods

One million 4T1-12B-luciferase expressing cells were transplanted into the mammary fat pad of BALB/c mice. Two weeks later, left (primary) tumors were either resected or cryoablated. A week after the procedure, right (abscopal) and left tumors, along with spleen, tumor-draining lymph node and blood were collected and processed for flow cytometry and/or RNA-sequencing and immunofluorescence.

Results

Here we show that cryoablation of mouse mammary carcinomas results in smaller abscopal tumors that harbor increased frequencies of anti-tumor cells [such as natural killer (NK) cells], accompanied by a systemic increase in the frequency of migratory conventional type 1 dendritic cells (cDC1; CD103+ XCR1+), compared to resection. The changes in cell frequencies are mirrored by the immune gene signature of the abscopal tumors, with cryoablation inducing genes involved with NK cell activation and leukocyte-mediated toxicity, including IL11ra1 and Pfr1.

Conclusions

These results better define the early mechanisms through which cryoablation improves tumor elimination, which is mediated by enhanced frequencies of anti-tumoral cells such as NK and cDC1s at the abscopal tumor and in the spleen of mice treated with cryoablation, respectively.

A key regulator of tumor-associated neutrophils: the CXCR2 chemokine receptor

In recent years, with the advance of research, the role of tumor-associated neutrophils (TANs) in tumors has become a research hotspot. As important effector cells in the innate immune system, neutrophils play a key role in the immune and inflammatory responses of the body. As the first line of defense against bacterial and fungal infections, neutrophils have the ability to kill invading pathogens. In the pathological state of malignant tumors, the phenotype of neutrophils is altered and has an important regulatory function in tumor development. The C-X-C motif chemokine receptor 2(CXCR2) is a key molecule that mediates the migration and aggregation signaling pathway of immune cells, especially neutrophils. This review focuses on the regulation of CXCR2 on TANs in the process of tumorigenesis and development, and emphasizes the application significance of CXCR2 inhibitors in blocking the migration of TANs to tumors.

Multifaceted Aspects of Dysfunctional Myelopoiesis in Cancer and Therapeutic Perspectives with Focus on HCC

Myelopoiesis provides for the formation and continued renewal of cells belonging primarily to the innate immune system. It is a highly plastic process that secures the response to external and internal stimuli to face acute and changing needs. Infections and chronic diseases including cancer can modulate it by producing several factors, impacting proliferation and differentiation programs. While the lymphocytic compartment has attracted major attention due to the role of adaptive immunity in anticancer immune response, in recent years, research has found convincing evidence that confirms the importance of innate immunity and the key function played by emergency myelopoiesis. Due to cancer's ability to manipulate myelopoiesis to its own advantage, the purpose of this review is to outline myelopoiesis processes within the tumor microenvironment and suggest possible therapeutic lines of research to restore the physiological functioning of the host's immune system, with a special outlook on hepatocellular carcinoma (HCC).

Optimized full-spectrum flow cytometry panel for deep immunophenotyping of murine lungs

The lung immune system consists of both resident and circulating immune cells that communicate intricately. The immune system is activated by exposure to bacteria and viruses, when cancer initiates in the lung (primary lung cancer), or when metastases of other cancer types, including breast cancer, spread to and develop in the lung (secondary lung cancer). Thus, in these pathological situations, a comprehensive and quantitative assessment of changes in the lung immune system is of paramount importance for understanding mechanisms of infectious diseases, lung cancer, and metastasis but also for developing efficacious treatments. Unfortunately, lung tissue exhibits high autofluorescence, and this high background signal makes high-parameter flow cytometry analysis complicated. Here, we provide an optimized 30-parameter antibody panel for the analysis of all major immune cell types and states in normal and metastatic murine lungs using spectral flow cytometry.

Immune Checkpoint Inhibitor Score Predicts Survival Benefit of Immunotherapy in Patients with Non-small Cell Lung Cancer

BACKGROUND

The use of immune checkpoint inhibitors (ICIs) in patients with advanced lung cancer is increasing. Despite ongoing studies to predict the efficacy of ICIs, its use in clinical practice remains difficult. Thus, we aimed to discover a predictive marker by analyzing blood cell characteristics and developing a scoring system for patients treated with ICIs.

METHODS

This was a prospective multicenter study in patients with advanced nonsmall cell lung cancer (NSCLC) who received ICIs as second-line treatment from June 2021 to November 2022. Blood cell parameters in routine blood samples were evaluated using an automated hematology analyzer. Immune checkpoint inhibitor score (IChIS) was calculated as the sum of neutrophil count score and immature granulocyte score.

RESULTS

A total of 143 patients from four institutions were included. The treatment response was as follows: partial response, 8.4%; stable disease, 37.1%; and progressive disease, 44.8%. Median progression-free survival and overall survival after ICI treatment was 3.0 and 8.3 months, respectively. Median progression-free survival in patients with an IChIS of 0 was 4.0 months, which was significantly longer than 1.9 months in patients with an IChIS of 1 and 1.0 month in those with an IChIS of 2 (p=0.001). The median overall survival in patients with an IChIS of 0 was 10.2 months, which was significantly longer than 6.8 and 1.8 months in patients with an IChIS of 1 and 2, respectively (p<0.001).

CONCLUSION

Baseline IChIS could be a potential biomarker for predicting survival benefit of immunotherapy in NSCLC.

The FLARE Score and Circulating Neutrophils in Patients with Cancer and COVID-19 Disease

PURPOSE

Inflammation and neutrophils play a central role in both COVID-19 disease and cancer. We aimed to assess the impact of pre-existing tumor-related inflammation on COVID-19 outcomes in patients with cancer and to elucidate the role of circulating neutrophil subpopulations.

METHODS

We conducted a multicenter retrospective analysis of 524 patients with cancer and SARS-CoV-2 infection, assessing the relationship between clinical outcomes and circulating inflammatory biomarkers collected before and during COVID-19 infection. Additionally, a single-center prospective cohort study provided data for an exploratory analysis, assessing the immunophenotype of circulating neutrophils and inflammatory cytokines. The primary endpoints were 30-day mortality and the severity of COVID-19 disease.

RESULTS

Prior to COVID-19, 25% of patients with cancer exhibited elevated dNLR, which increased to 55% at the time of COVID-19 diagnosis. We developed the FLARE score, incorporating both tumor- and infection-induced inflammation, which categorized patients into four prognostic groups. The poor prognostic group had a 30-day mortality rate of 68%, significantly higher than the 23% in the favorable group (p < 0.0001). This score proved to be an independent predictor of early mortality. This prospective analysis revealed a shift towards immature forms of neutrophils and higher IL-6 levels in patients with cancer and severe COVID-19 infection.

CONCLUSIONS

A pre-existing tumor-induced pro-inflammatory state significantly impacts COVID-19 outcomes in patients with cancer. The FLARE score, derived from circulating inflammatory markers, emerges as an easy-to-use, globally accessible, effective tool for clinicians to identify patients with cancer at heightened risk of severe COVID-19 complications and early mortality who might benefit most from immediate and intensive treatment strategies. Furthermore, our findings underscore the significance of immature neutrophils in the progression of COVID-19 in patients with cancer, advocating for further investigation into how these cells contribute to both cancer and COVID-19 disease.

Neutrophil-like Monocytes Increase in Patients with Colon Cancer and Induce Dysfunctional TIGIT+ NK Cells

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous family of immune cells including granulocytic (CD14neg/CD15+/HLA-DRneg) and monocytic subtypes (CD14+/CD15neg/HLA-DRneg). In the present study, we found a population of monocytes expressing the granulocyte marker CD15 that significantly increased in both peripheral blood (PB) and tumoral tissues of patients with colorectal cancer (CRC). Further phenotypical analysis confirmed the granulocytic-like features of this monocyte subpopulation that is associated with an increase in granulocyte-monocyte precursors (GMPs) in the PB of these patients (pts). Mechanistically, this granulocyte-like monocyte population suppressed NK cell activity by inducing TIGIT and engaging NKp30. Accordingly, an increased frequency of TIGIT+ NK cells with impaired functions was found in both the PB and tumoral tissue of CRC pts. Collectively, we provided new mechanistic explanations for tumor immune escape occurring in CRC by showing the increase in this new kind of MDSC, in both PB and CRC tissue, which is able to significantly impair the effector functions of NK cells, thereby representing a potential therapeutic target for cancer immunotherapy.

Neutrophils in Ocular Diseases

Neutrophils, traditionally viewed as first responders to infection or tissue damage, exhibit dynamic and diverse roles in ocular health and disease. This review elaborates on previous findings that showed how neutrophils contribute to ocular diseases. In ocular infections, neutrophils play a pivotal role in host defense by orchestrating inflammatory responses to combat pathogens. Furthermore, in optic nerve neuropathies and retinal degenerative diseases like age-related macular degeneration (AMD) and diabetic retinopathy (DR), neutrophils are implicated in neuroinflammation and tissue damage owing to their ability to undergo neutrophil extracellular trap formation (NETosis) and secretion of inflammatory molecules. Targeting neutrophil-dependent processes holds promise as a therapeutic strategy, offering potential avenues for intervention in ocular infections, cancers, and retinal degenerative diseases. Understanding the multifaceted roles of neutrophils in ocular diseases is crucial for developing targeted therapies to improve patient outcomes.

Comparative immune profiling of pancreatic ductal adenocarcinoma progression among South African patients

BACKGROUND

Pancreatic Ductal Adenocarcinoma (PDAC) is an aggressive cancer characterized by an immunosuppressive microenvironment. Patients from specific ethnicities and population groups have poorer prognoses than others. Therefore, a better understanding of the immune landscape in such groups is necessary for disease elucidation, predicting patient outcomes and therapeutic targeting. This study investigated the expression of circulating key immune cell markers in South African PDAC patients of African ancestry.

METHODS

Blood samples were obtained from a total of 6 healthy volunteers (HC), 6 Chronic Pancreatitis (CP) and 34 PDAC patients consisting of 22 resectable (RPC), 8 locally advanced (LAPC) and 4 metastatic (MPC). Real-time Quantitative Polymerase Chain reactions (RT-qPCR), Metabolomics, Enzyme-Linked Immunosorbent Assay (ELISA), Reactive Oxygen Species (ROS), and Immunophenotyping assays were conducted. Statistical analysis was conducted in R (v 4.3.2). Additional analysis of single-cell RNA data from 20 patients (16 PDAC and 4 controls) was conducted to interrogate the distribution of T-cell and Natural Killer cell populations.

RESULTS

Granulocyte and neutrophil levels were significantly elevated while lymphocytes decreased with PDAC severity. The total percentages of CD3 T-cell subpopulations (helper and double negative T-cells) decreased when compared to HC. Although both NK (p = 0.014) and NKT (p < 0.001) cell levels increased as the disease progressed, their subsets: NK CD56dimCD16- (p = 0.024) and NKTs CD56+ (p = 0.008) cell levels reduced significantly. Of note is the negative association of NK CD56dimCD16- (p < 0.001) cell levels with survival time. The gene expression analyses showed no statistically significant correlation when comparing the PDAC groups with the controls. The inflammatory status of PDAC was assessed by ROS levels of serum which were elevated in CP (p = 0.025), (RPC (p = 0.003) and LAPC (p = 0.008)) while no significant change was observed in MPC, compared to the HC group. ROS was shown to be positively correlated with GlycA (R = 0.45, p = 0.0096). Single-cell analyses showed a significant difference in the ratio of NKT cells per total cell counts in LAPC (p < 0.001) and MPC (p < 0.001) groups compared with HC, confirming observations in our sample group.

CONCLUSION

The expression of these immune cell markers observed in this pilot study provides insight into their potential roles in tumour progression in the patient group and suggests their potential utility in the development of immunotherapeutic strategies.

Neutrophil in the suppressed immune microenvironment: Critical prognostic factor for lung adenocarcinoma patients with KEAP1 mutation

Purpose

It is still unclear whether KEAP1 mutation is detrimental to immunotherapy of lung adenocarcinoma (LUAD) patients, we try to analyse the exact changes in the TME in LUAD patients with KEAP1 mutations and to identify key factors influencing prognosis.

Experimental design

A total of 1,029 patients with lung squamous carcinoma (LUSC) or LUAD with data obtained from The Cancer Genome Atlas were included in this study. The TME and OS of patients with LUAD stratified by mutant versus wild-type KEAP1 status were comprehensively measured. Moreover, we classified LUAD patients with KEAP1 mutations into three subtypes, by unsupervised consensus clustering. We further analysed the TME, OS, commutated genes and metabolic pathways of different subgroups. A total of 40 LUAD patients underwent immunotherapy were collected and classified into mutant KEAP1 group and wild-type KEAP1 group. We also conducted immunohistochemical staining in KEAP1-MT groups.

Result

Suppressed TME was observed not only in LUAD patients but also in LUSC patients. LUAD patients with mutant KEAP1 underwent immunotherapy had worse PFS than wild-type KEAP1. Unsupervised consensus clustering analysis suggested that the three subtypes of patients exhibited different densities of neutrophil infiltration and had different OS results: cluster 2 patients had significantly higher levels of neutrophils had significantly worse prognoses than those of patients in clusters 1 and 3 and patients with wild-type KEAP1. Univariate and multivariate Cox analyses proved that a high density of neutrophils was significantly associated with worse OS and immunohistochemical staining proved that shorter PFS showed high density of neutrophils.

Conclusion

KEAP1 mutation significantly suppresses the tumour immune microenvironment in LUAD patients. LUAD patients with mutant KEAP1 underwent immunotherapy had worse PFS than with wild-type KEAP1. Neutrophils may play an important role in the prognosis of LUAD patients with KEAP1 mutations and may provide a promising therapeutic target.

Comparative transcriptomics coupled to developmental grading via transgenic zebrafish reporter strains identifies conserved features in neutrophil maturation

Neutrophils are evolutionarily conserved innate immune cells playing pivotal roles in host defense. Zebrafish models have contributed substantially to our understanding of neutrophil functions but similarities to human neutrophil maturation have not been systematically characterized, which limits their applicability to studying human disease. Here we show, by generating and analysing transgenic zebrafish strains representing distinct neutrophil differentiation stages, a high-resolution transcriptional profile of neutrophil maturation. We link gene expression at each stage to characteristic transcription factors, including C/ebp-β, which is important for late neutrophil maturation. Cross-species comparison of zebrafish, mouse, and human samples confirms high molecular similarity of immature stages and discriminates zebrafish-specific from pan-species gene signatures. Applying the pan-species neutrophil maturation signature to RNA-sequencing data from human neuroblastoma patients reveals association between metastatic tumor cell infiltration in the bone marrow and an overall increase in mature neutrophils. Our detailed neutrophil maturation atlas thus provides a valuable resource for studying neutrophil function at different stages across species in health and disease.

Identification of neutrophil-related genes and development of a prognostic model for cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma is a prevalent gastrointestinal tumor with limited effective early diagnostic methods. The role of neutrophils in the context of cholangiocarcinoma remains largely unexplored.

METHODS

A comprehensive analysis was performed on a cohort of cholangiocarcinoma samples (TCGA-CHOL) from the TCGA database to investigate the relationship between cholangiocarcinoma and neutrophils. Methodologies included single-sample gene set enrichment analysis (ssGSEA), differential expression analysis, weighted gene co-expression network analysis (WGCNA) and gene set enrichment analysis (GSEA).

RESULTS

The study identified a significant decrease of neutrophils in cholangiocarcinoma via ssGSEA. WGCNA and differential expression analysis led to the identification of a neutrophil-related gene module comprised of 1059 genes. Cluster 1, showing a higher proportion of neutrophils, was linked to better survival outcomes. GSEA disclosed downregulation of complement, inflammatory response and interferon response pathways in Cluster 2, hinting at possible cholangiocarcinoma development triggers. A notable upregulation of PD1, PD-L1 and CTLA4 was observed in Cluster 1, suggesting potential benefits from immunotherapy. A prognostic model was developed based on clinical data and expression levels of three prognostic genes (SOWAHD, TNFAIP8 and EBF3) showing satisfactory discrimination, calibration and clinical benefits. An overexpression of TNFAIP8 in cholangiocarcinoma cells was found, with its knockdown significantly inhibiting cell proliferation and migration.

CONCLUSIONS

This study elucidates a neutrophil-related gene module and prognostic genes, offering insights into the role of neutrophils in cholangiocarcinoma development and progression. It also introduces a clinical prediction model for enhanced prognosis assessment. These findings may lay the groundwork for the development of innovative therapeutic strategies in cholangiocarcinoma treatment.

Nasopharyngeal neutrophilic-retention signatures could predict disease progression in early SARS-CoV-2 infection

The nasopharynx is the initial site of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, and neutrophils play a critical role in preventing viral transmission into the lower airways or lungs during the early phases of infection. However, neutrophil dynamics, functional signatures, and predictive roles in the nasopharynx of coronavirus disease 2019 (COVID-19) patients have not yet been elucidated. In this study, we carried out RNA sequencing of nasopharyngeal swabs from a cohort of COVID-19 patients with mild, moderate, severe outcomes and healthy donors as controls. Over 32.7% of the differentially expressed genes associated with COVID-19 severity were neutrophil-related, including those involved in migration, neutrophil extracellular traps formation, and inflammasome activation. Multicohort single-cell RNA sequencing analysis further confirmed these findings and identified a population of neutrophils expressing Vacuolar-type ATPase (V-ATPase) and the chemokine receptor CXCR4 in the nasopharynx. This population of neutrophils preferentially expressed pro-inflammatory genes relevant to phagosomal maturation as well as local reactive oxygen species and reactive nitrogen species production in the nasopharynx of patients with severe outcomes. A four-gene panel defined as a neutrophil signature associated with COVID-19 progression (NSAP) was identified as an early diagnostic predictor of severe COVID-19, which potentially distinguished severe patients from mild cases with influenza, respiratory syncytial virus, dengue virus, or hepatitis B virus infection. NSAP is mainly expressed on CXCR4high neutrophils and exhibits a significant association with the cell fraction of this neutrophil population. This study highlights novel potential therapeutic targets or diagnostic tools for predicting patients at a higher risk of severe outcomes.

Immunosuppressive low-density neutrophils in the blood of cancer patients display a mature phenotype

The presence of human neutrophils in the tumor microenvironment is strongly correlated to poor overall survival. Most previous studies have focused on the immunosuppressive capacities of low-density neutrophils (LDN), also referred to as granulocytic myeloid-derived suppressor cells, which are elevated in number in the blood of many cancer patients. We observed two types of LDN in the blood of lung cancer and ovarian carcinoma patients: CD45high LDN, which suppressed T-cell proliferation and displayed mature morphology, and CD45low LDN, which were immature and non-suppressive. We simultaneously evaluated the classical normal-density neutrophils (NDN) and, when available, tumor-associated neutrophils. We observed that NDN from cancer patients suppressed T-cell proliferation, and NDN from healthy donors did not, despite few transcriptomic differences. Hence, the immunosuppression mediated by neutrophils in the blood of cancer patients is not dependent on the cells' density but rather on their maturity.

Neutrophils as potential therapeutic targets for breast cancer

Breast cancer (BC) remains the foremost cause of cancer mortality globally, with neutrophils playing a critical role in its pathogenesis. As an essential tumor microenvironment (TME) component, neutrophils are emerging as pivotal factors in BC progression. Growing evidence has proved that neutrophils play a Janus- role in BC by polarizing into the anti-tumor (N1) or pro-tumor (N2) phenotype. Clinical trials are evaluating neutrophil-targeted therapies, including Reparixin (NCT02370238) and Tigatuzumab (NCT01307891); however, their clinical efficacy remains suboptimal. This review summarizes the evidence regarding the close relationship between neutrophils and BC, emphasizing the critical roles of neutrophils in regulating metabolic and immune pathways. Additionally, we summarize the existing therapeutic approaches that target neutrophils, highlighting the challenges, and affirming the rationale for continuing to explore neutrophils as a viable therapeutic target in BC management.

Glycoproteome remodeling and organelle-specific N-glycosylation accompany neutrophil granulopoiesis

Neutrophils store microbicidal glycoproteins in cytosolic granules to fight intruding pathogens, but their granule distribution and formation mechanism(s) during granulopoiesis remain unmapped. Herein, we comprehensively profile the neutrophil N-glycoproteome with spatiotemporal resolution by analyzing four key types of intracellular organelles isolated from blood-derived neutrophils and during their maturation from bone marrow-derived progenitors using a glycomics-guided glycoproteomics approach. Interestingly, the organelles of resting neutrophils exhibited distinctive glycophenotypes including, most strikingly, highly truncated N-glycans low in α2,6-sialylation and Lewis fucosylation decorating a diverse set of microbicidal proteins (e.g., myeloperoxidase, azurocidin, neutrophil elastase) in the azurophilic granules. Excitingly, proteomics and transcriptomics data from discrete myeloid progenitor stages revealed that profound glycoproteome remodeling underpins the promyelocytic-to-metamyelocyte transition and that the glycophenotypic differences are driven primarily by dynamic changes in protein expression and less by changes within the glycosylation machinery. Notable exceptions were the oligosaccharyltransferase subunits responsible for initiation of N-glycoprotein biosynthesis that were strongly expressed in early myeloid progenitors correlating with relatively high levels of glycosylation of the microbicidal proteins in the azurophilic granules. Our study provides spatiotemporal insights into the complex neutrophil N-glycoproteome featuring intriguing organelle-specific N-glycosylation patterns formed by dynamic glycoproteome remodeling during the early maturation stages of the myeloid progenitors.

The molecular basis of tumor metastasis and current approaches to decode targeted migration-promoting events in pediatric neuroblastoma

Cell motility is a crucial biological process that plays a critical role in the development of multicellular organisms and is essential for tissue formation and regeneration. However, uncontrolled cell motility can lead to the development of various diseases, including neoplasms. In this review, we discuss recent advances in the discovery of regulatory mechanisms underlying the metastatic spread of neuroblastoma, a solid pediatric tumor that originates in the embryonic migratory cells of the neural crest. The highly motile phenotype of metastatic neuroblastoma cells requires targeting of intracellular and extracellular processes, that, if affected, would be helpful for the treatment of high-risk patients with neuroblastoma, for whom current therapies remain inadequate. Development of new potentially migration-inhibiting compounds and standardized preclinical approaches for the selection of anti-metastatic drugs in neuroblastoma will also be discussed.

Low-density granulocytes display immature cells with enhanced NET formation in people living with HIV

While the protective role of neutrophil extracellular traps (NETs) in limiting human immunodeficiency virus (HIV) spread to susceptible cells has been documented, there is comparatively little insight into whether NET formation is harmful in people living with HIV (PLWH). To gain insight into neutrophil dysregulation and the pathological role of NETs in HIV, we examined expressions of NET-associated markers [cell-free DNA (cfDNA) and citrullinated histone H3 (CitH3)] in the plasmas from a cohort of the Hawaii Aging with HIV-cardiovascular and HIV-seronegative (HIV-) individuals. In a subset of participants, circulating low-density granulocyte (LDG) levels and their maturation and activation status were analyzed via flow cytometry. We demonstrated higher plasma levels of CitH3 in PLWH compared to HIV- individuals. LDGs from PLWH had heightened CD66b, but reduced CD16 expression. The percentages and counts of CD10+ LDGs were significantly decreased in PLWH. In addition, the CD16Lo LDG subsets were enriched in PLWH, compared to HIV- group, indicating that immature LDGs are increased in PLWH. Moreover, LDGs from PLWH exhibited significantly higher NET forming capacity. In summary, our study presents evidence that LDGs from PLWH on ART display an immature and altered phenotype with increased NET formation. Among PLWH, plasma NET levels as well as LDG parameters correlated with blood markers for inflammation and coagulation, suggesting that neutrophil activation and NETs may exert proinflammatory and coagulation effects. Our data provide insights into the pathologic role of LDGs at least in part mediated through NET formation in PLWH.

The double-edged role of neutrophil heterogeneity in inflammatory diseases and cancers

Neutrophils are important immune cells act as the body's first line of defense against infection and respond to diverse inflammatory cues. Many studies have demonstrated that neutrophils display plasticity in inflammatory diseases and cancers. Clarifying the role of neutrophil heterogeneity in inflammatory diseases and cancers will contribute to the development of novel treatment strategies. In this review, we have presented a review on the development of the understanding on neutrophil heterogeneity from the traditional perspective and a high-resolution viewpoint. A growing body of evidence has confirmed the double-edged role of neutrophils in inflammatory diseases and tumors. This may be due to a lack of precise understanding of the role of specific neutrophil subsets in the disease. Thus, elucidating specific neutrophil subsets involved in diseases would benefit the development of precision medicine. Thusly, we have summarized the relevance and actions of neutrophil heterogeneity in inflammatory diseases and cancers comprehensively. Meanwhile, we also discussed the potential intervention strategy for neutrophils. This review is intended to deepen our understanding of neutrophil heterogeneity in inflammatory diseases and cancers, while hold promise for precise treatment of neutrophil-related diseases.

c-Met Mediated Cytokine Network Promotes Brain Metastasis of Breast Cancer by Remodeling Neutrophil Activities

The brain is one of the most common metastatic sites among breast cancer patients, especially in those who have Her2-positive or triple-negative tumors. The brain microenvironment has been considered immune privileged, and the exact mechanisms of how immune cells in the brain microenvironment contribute to brain metastasis remain elusive. In this study, we found that neutrophils are recruited and influenced by c-Met high brain metastatic cells in the metastatic sites, and depletion of neutrophils significantly suppressed brain metastasis in animal models. Overexpression of c-Met in tumor cells enhances the secretion of a group of cytokines, including CXCL1/2, G-CSF, and GM-CSF, which play critical roles in neutrophil attraction, granulopoiesis, and homeostasis. Meanwhile, our transcriptomic analysis demonstrated that conditioned media from c-Met high cells significantly induced the secretion of lipocalin 2 (LCN2) from neutrophils, which in turn promotes the self-renewal of cancer stem cells. Our study unveiled the molecular and pathogenic mechanisms of how crosstalk between innate immune cells and tumor cells facilitates tumor progression in the brain, which provides novel therapeutic targets for treating brain metastasis.

NETworking with cancer: The bidirectional interplay between cancer and neutrophil extracellular traps

Neutrophils are major effectors and regulators of the immune system. They play critical roles not only in the eradication of pathogens but also in cancer initiation and progression. Conversely, the presence of cancer affects neutrophil activity, maturation, and lifespan. By promoting or repressing key neutrophil functions, cancer cells co-opt neutrophil biology to their advantage. This co-opting includes hijacking one of neutrophils' most striking pathogen defense mechanisms: the formation of neutrophil extracellular traps (NETs). NETs are web-like filamentous extracellular structures of DNA, histones, and cytotoxic granule-derived proteins. Here, we discuss the bidirectional interplay by which cancer stimulates NET formation, and NETs in turn support disease progression. We review how vascular dysfunction and thrombosis caused by neutrophils and NETs underlie an elevated risk of death from cardiovascular events in cancer patients. Finally, we propose therapeutic strategies that may be effective in targeting NETs in the clinical setting.

Alpha-galactosylceramide as adjuvant induces protective cell-mediated immunity against Leishmania mexicana infection in vaccinated BALB/c mice

Adjuvants represent a promising strategy to improve vaccine effectiveness against infectious diseases such as leishmaniasis. Vaccination with the invariant natural killer T cell ligand α-galactosylceramide (αGalCer) has been used successfully as adjuvant, generating a Th1-biased immunomodulation. This glycolipid enhances experimental vaccination platforms against intracellular parasites including Plasmodium yoelii and Mycobacterium tuberculosis. In the present study, we assessed the protective immunity induced by a single-dose intraperitoneal injection of αGalCer (2 μg) co-administrated with a lysate antigen of amastigotes (100 μg) against Leishmania mexicana infection in BALB/c mice. The prophylactic vaccination led to 5.0-fold reduction of parasite load at the infection site, compared to non-vaccinated mice. A predominant pro-inflammatory response was observed in challenged vaccinated mice, represented by a 1.9 and 2.8-fold-increase of IL-1β and IFN-γ producing cells, respectively, in the lesions, and by 23.7-fold-increase of IFN-γ production in supernatants of restimulated splenocytes, all compared to control groups. The co-administration of αGalCer also stimulated the maturation of splenic dendritic cells and modulated a Th1-skewed immune response, with high amounts of IFN-γ production in serum. Furthermore, peritoneal cells of αGalCer-immunized mice exhibited an elevated expression of Ly6G and MHCII. These findings indicate that αGalCer improves protection against cutaneous leishmaniasis, supporting evidence for its potential use as adjuvant in Leishmania-vaccines.

New Therapeutics for HCC: Does Tumor Immune Microenvironment Matter?

The incidence of liver cancer is continuously rising where hepatocellular carcinoma (HCC) remains the most common form of liver cancer accounting for approximately 80-90% of the cases. HCC is strongly prejudiced by the tumor microenvironment and being an inflammation-associated condition, the contribution of various immune mechanisms is critical in its development, progression, and metastasis. The tumor immune microenvironment is initially inflammatory which is subsequently replenished by the immunosuppressive cells contributing to tumor immune escape. Regardless of substantial advancement in systemic therapy, HCC has poor prognosis and outcomes attributed to the drug resistance, recurrence, and its metastatic behavior. Therefore, currently, new immunotherapeutic strategies are extensively targeted in preclinical and clinical settings in order to elicit robust HCC-specific immune responses and appear to be quite effective, extending current treatment alternatives. Understanding the complex interplay between the tumor and the immune cells and its microenvironment will provide new insights into designing novel immunotherapeutics to overcome existing treatment hurdles. In this review, we have provided a recent update on immunological mechanisms associated with HCC and discussed potential advancement in immunotherapies for HCC treatment.

Gestationally dependent immune organization at the maternal-fetal interface

The immune system and placenta have a dynamic relationship across gestation to accommodate fetal growth and development. High-resolution characterization of this maternal-fetal interface is necessary to better understand the immunology of pregnancy and its complications. We developed a single-cell framework to simultaneously immuno-phenotype circulating, endovascular, and tissue-resident cells at the maternal-fetal interface throughout gestation, discriminating maternal and fetal contributions. Our data reveal distinct immune profiles across the endovascular and tissue compartments with tractable dynamics throughout gestation that respond to a systemic immune challenge in a gestationally dependent manner. We uncover a significant role for the innate immune system where phagocytes and neutrophils drive temporal organization of the placenta through remarkably diverse populations, including PD-L1⁺ subsets having compartmental and early gestational bias. Our approach and accompanying datasets provide a resource for additional investigations into gestational immunology and evoke a more significant role for the innate immune system in establishing the microenvironment of early pregnancy.

Loss of Cxcr2 in Myeloid Cells Promotes Tumour Progression and T Cell Infiltration in Invasive Bladder Cancer

BACKGROUND

CXCR2 is a chemokine receptor expressed in myeloid cells, including neutrophils and macrophages. Pharmacological inhibition of CXCR2 has been shown to sensitize tumours to immune checkpoint inhibitor immunotherapies in some cancer types.

OBJECTIVE

To investigate the effects of CXCR2 loss in regulation of tumour-infiltrating myeloid cells and their relationship to lymphocytes during bladder tumorigenesis.

METHODS

Urothelial pathogenesis and immune contexture was investigated in an OH-BBN model of invasive bladder cancer with Cxcr2 deleted in myeloid cells (LysMCre Cxcr2 flox/flox ). CXCR2 gene alterations and expression in human muscle invasive bladder cancer were analysed in The Cancer Genome Atlas.

RESULTS

Urothelial tumour pathogenesis was significantly increased upon Cxcr2 deletion compared to wildtype mice. This was associated with a suppression of myeloid cell infiltration in Cxcr2-deleted bladders shortly after the carcinogen induction. Interestingly, following a transient increase of macrophages at the outset of tumour formation, an increase in T cell infiltration was observed in Cxcr2-deleted tumours. The increased tumour burden in the Cxcr2-deleted bladder was largely independent of T cells and the status of immune suppression. The Cxcr2-deleted mouse model reflected the low CXCR2 mRNA range in human bladder cancer, which showed poor overall survival.

CONCLUSIONS

In contrast to previous reports of increased CXCR2 signalling associated with disease progression and poor prognosis, CXCR2 was protective against bladder cancer during tumour initiation. This is likely due to a suppression of acute inflammation. The strategy for sensitizing checkpoint immunotherapy by CXCR2 inhibition in bladder cancer may benefit from an examination of immune suppressive status.

The Role of Neutrophils in Oncolytic Orf Virus-Mediated Cancer Immunotherapy

Neutrophils are innate leukocytes with diverse effector functions that allow them to respond to pathogens rapidly. Accumulating evidence has highlighted these cells’ complex roles in the host’s response to viral infections and tumor progression. Oncolytic virotherapy is emerging as a promising treatment modality in the armamentarium of cancer therapeutics. Oncolytic viruses preferentially kill cancer cells and stimulate tumor-associated inflammation, resulting in tumor regression. Assessing the activity of individual effector cell subsets following oncolytic virotherapy is important in identifying their contribution to antitumor immunity. In this study, we investigated the role of neutrophils in oncolytic Orf-virus-mediated immunotherapy in a murine model of pulmonary melanoma metastases. The systemic administration of the Orf virus stimulated a dramatic increase in the number of leukocytes in circulation and within the tumor microenvironment, most of which were neutrophils. Analysis of tumor-burdened lungs shortly after therapy revealed significant numbers of phenotypically immature neutrophils, with the enhanced expression of molecules affiliated with activation, migration, and cytotoxicity. Neutrophils stimulated by Orf virus therapy were directly tumoricidal through tumor necrosis factor-α-mediated effects and were required for optimal antitumor efficacy following Orf virus therapy. Taken together, these data reveal neutrophils as a crucial innate effector to consider when investigating oncolytic virotherapy.

A tumor microenvironment gene set–Based prognostic signature for non-small-cell lung cancer

Background: The tumor microenvironment (TME) is involved in the development and progression of lung carcinomas. A deeper understanding of TME landscape would offer insight into prognostic biomarkers and potential therapeutic targets investigation. To this end, we aimed to identify the TME components of lung cancer and develop a prognostic signature to predict overall survival (OS).

Methods: Expression data was retrieved from The Cancer Genome Atlas (TCGA) database and differentially expressed TME-related genes were calculated between tumor and normal tissues. Then nonnegative matrix factorization (NMF) clustering was used to identify two distinct subtypes.

Results: Our analysis yielded a gene panel consisting of seven TME-related genes as candidate signature set. With this panel, our model showed that the high-risk group experienced a shorter survival time. This model was further validated by an independent cohort with data from Gene Expression Omnibus (GEO) database (GSE50081 and GSE13213). Additionally, we integrated the clinical factors and risk score to construct a nomogram for predicting prognosis. Our data suggested less immune cells infiltration but more fibroblasts were found in tumor tissues derived from patients at high-risk and those patients exhibited a worse immunotherapy response.

Conclusion: The signature set proposed in this work could be an effective model for estimating OS in lung cancer patients. Hopefully analysis of the TME could have the potential to provide novel diagnostic, prognostic and therapeutic opportunities.

CAR T Cell Therapy in Hematological Malignancies: Implications of the Tumor Microenvironment and Biomarkers on Efficacy and Toxicity

Chimeric antigen receptor (CAR) T cell therapy has ushered in a new era in cancer treatment. Remarkable outcomes have been demonstrated in patients with previously untreatable relapsed/refractory hematological malignancies. However, optimizing efficacy and reducing the risk of toxicities have posed major challenges, limiting the success of this therapy. The tumor microenvironment (TME) plays an important role in CAR T cell therapy’s effectiveness and the risk of toxicities. Increasing research studies have also identified various biomarkers that can predict its effectiveness and risk of toxicities. In this review, we discuss the various aspects of the TME and biomarkers that have been implicated thus far and discuss the role of creating scoring systems that can aid in further refining clinical applications of CAR T cell therapy and establishing a safe and efficacious personalised medicine for individuals.

The 'Danse Macabre'-Neutrophils the Interactive Partner Affecting Oral Cancer Outcomes

Over the past few decades, tremendous advances in the prevention, diagnosis, and treatment of cancer have taken place. However for head and neck cancers, including oral cancer, the overall survival rate is below 50% and they remain the seventh most common malignancy worldwide. These cancers are, commonly, aggressive, genetically complex, and difficult to treat and the delay, which often occurs between early recognition of symptoms and diagnosis, and the start of treatment of these cancers, is associated with poor prognosis. Cancer development and progression occurs in concert with alterations in the surrounding stroma, with the immune system being an essential element in this process. Despite neutrophils having major roles in the pathology of many diseases, they were thought to have little impact on cancer development and progression. Recent studies are now challenging this notion and placing neutrophils as central interactive players with other immune and tumor cells in affecting cancer pathology. This review focuses on how neutrophils and their sub-phenotypes, N1, N2, and myeloid-derived suppressor cells, both directly and indirectly affect the anti-tumor and pro-tumor immune responses. Emphasis is placed on what is currently known about the interaction of neutrophils with myeloid innate immune cells (such as dendritic cells and macrophages), innate lymphoid cells, natural killer cells, and fibroblasts to affect the tumor microenvironment and progression of oral cancer. A better understanding of this dialog will allow for improved therapeutics that concurrently target several components of the tumor microenvironment, increasing the possibility of constructive and positive outcomes for oral cancer patients. For this review, PubMed, Web of Science, and Google Scholar were searched for manuscripts using keywords and combinations thereof of "oral cancer, OSCC, neutrophils, TANs, MDSC, immune cells, head and neck cancer, and tumor microenvironment" with a focus on publications from 2018 to 2021.

Dual-Targeted Lipid Nanotherapeutic Boost for Chemo-Immunotherapy of Cancer

Chemo-immunotherapy is a combination of "standard-of-care" chemotherapy with immunotherapy and it is considered the most advanced therapeutic modality for various types of cancers. However, many cancer patients still poorly respond to current regimen of chemo-immunotherapy and suggest nanotherapeutics as a boosting agent. Recently, heme oxygenase-1 (HO1) is shown to act as an immunotherapeutic molecule in tumor myeloid cells, in addition to general chemoresistance function in cancer cells suggesting that HO1-targeted therapeutics can become a novel, optimal strategy for boosting chemo-immunotherapy in the clinic. Currently the available HO1-inhibitors demonstrate serious adverse effects in clinical use. Herein, tumor myeloid cell- and cancer cell-dual targeted HO1-inhibiting lipid nanotherapeutic boost (T-iLNTB) is developed using RNAi-loaded lipid nanoparticles. T-iLNTB-mediated HO1-inhibition sensitizes cancer cells to "standard-of-care" chemotherapeutics by increasing immunogenic cell death, and directly reprograms tumor myeloid cells with distinguished phenotype. Furthermore, tumor myeloid cell reprogramming by T-iLNTB induces CD8⁺ cytotoxic T cell recruitment, which drives "Cold-to-Hot" transition and correlates with improved responsiveness to immune checkpoint inhibitor in combination therapy. Finally, ex vivo study proves that HO1-inhibition directly affects tumor macrophage differentiation. This study demonstrates the potential of T-iLNTB as a novel therapeutic modality for boosting chemo-immunotherapy.

Neutrophils as potential therapeutic targets in hepatocellular carcinoma

The success of atezolizumab plus bevacizumab treatment contributed to a shift in systemic therapies for hepatocellular carcinoma (HCC) towards combinations that include cancer immunotherapeutic agents. Thus far, the principal focus of cancer immunotherapy has been on interrupting immune checkpoints that suppress antitumour lymphocytes. As well as lymphocytes, the HCC environment includes numerous other immune cell types, among which neutrophils are emerging as an important contributor to the pathogenesis of HCC. A growing body of evidence supports neutrophils as key mediators of the immunosuppressive environment in which some cancers develop, as well as drivers of tumour progression. If neutrophils have a similar role in HCC, approaches that target or manipulate neutrophils might have therapeutic benefits, potentially including sensitization of tumours to conventional immunotherapy. Several neutrophil-directed therapies for patients with HCC (and other cancers) are now entering clinical trials. This Review outlines the evidence in support of neutrophils as drivers of HCC and details their mechanistic roles in development, progression and metastasis, highlighting the reasons that neutrophils are well worth investigating despite the challenges associated with studying them. Neutrophil-modulating anticancer therapies entering clinical trials are also summarized.

NETosis and Neutrophil Extracellular Traps in COVID-19: Immunothrombosis and Beyond

Infection with SARS-CoV-2, the causative agent of the Coronavirus disease 2019 (COVID-19) pandemic, causes respiratory problems and multifaceted organ dysfunction. A crucial mechanism of COVID-19 immunopathy is the recruitment and activation of neutrophils at the infection site, which also predicts disease severity and poor outcomes. The release of neutrophil extracellular traps (NETs), occurring during a regulated form of neutrophil cell death known as NETosis, is a key effector function that mediates harmful effects caused by neutrophils. Abundant NETosis and NET generation have been observed in the neutrophils of many COVID-19 patients, leading to unfavorable coagulopathy and immunothrombosis. Moreover, excessive NETosis and NET generation are now more widely recognized as mediators of additional pathophysiological abnormalities following SARS-CoV-2 infection. In this minireview, we introduce subtypes of NET-producing neutrophils (e.g., low-density granulocytes) and explain the biological importance of NETs and the protein cargos of NETs in COVID-19. In addition, we discuss the mechanisms by which SARS-CoV-2 causes NETosis by upregulating viral processes (e.g., viral entry and replication) as well as host pro-NET mechanisms (e.g., proinflammatory mediator release, platelet activation, and autoantibody production). Furthermore, we provide an update of the main findings of NETosis and NETs in immunothrombosis and other COVID-19-related disorders, such as aberrant immunity, neurological disorders, and post COVID-19 syndromes including lung fibrosis, neurological disorder, tumor progression, and deteriorated chronic illness. Finally, we address potential prospective COVID-19 treatment strategies that target dysregulated NETosis and NET formation via inhibition of NETosis and promotion of NET degradation, respectively.

Preoperative Breast Immune Prognostic Index as Prognostic Factor Predicts the Clinical Outcomes of Breast Cancer Patients Receiving Neoadjuvant Chemotherapy

Objective

This study aims at investigating the potential prognostic significance of the breast immune prognostic index (BIPI) in breast cancer patients who received neoadjuvant chemotherapy (NACT).

Methods

The optimal cutoff value was calculated through the receiver operating characteristic curve (ROC). The correlations between BIPI and clinicopathologic characteristics were determined by the chi-square test or Fisher’s exact test. The Kaplan–Meier method was used to estimate the survival probability, and the log-rank test was used to analyze the differences in the survival probability among patients. The univariate and multivariate Cox proportional hazard regression model was used to screen the independent prognostic factors. A prognostic nomogram for disease-free survival (DFS) and overall survival (OS) was built on the basis of the multivariate analyses. Furthermore, the calibration curve and decision curve analysis (DCA) were used to assess the predictive performance of the nomogram.

Results

All enrolled patients were split into three subgroups based on the BIPI score. The mean DFS and OS of the BIPI score 0 group and BIPI score 1 group were significantly longer than those of the BIPI score 2 group (42.02 vs. 38.61 vs. 26.01 months, 77.61 vs. 71.83 vs. 53.15 months; p < 0.05). Univariate and multivariate analyses indicated that BIPI was an independent prognostic factor for patients’ DFS and OS (DFS, hazard ratio (HR): 6.720, 95% confidence interval (CI): 1.629–27.717; OS, HR: 8.006, 95% CI: 1.638–39.119). A nomogram with a C-index of 0.873 (95% CI: 0.779–0.966) and 0.801 (95% CI: 0.702–0.901) had a favorable performance for predicting DFS and OS survival rates for clinical use by combining immune scores with other clinical features. The calibration curves at 1-, 3-, and 5-year survival suggested a good consistency between the predicted and actual DFS and OS probability. The DCA demonstrated that the constructed nomogram had better clinical predictive usefulness than only BIPI in predictive clinical applications of 5-year DFS and OS prognostic assessments.

Conclusions

The patients with low BIPI score have better prognoses and longer DFS and OS. Furthermore, the BIPI-based nomogram may serve as a convenient prognostic tool for breast cancer and help in clinical decision-making.

A curious case of cyclin‐dependent kinases in neutrophils

Neutrophils are terminally differentiated, short-lived white blood cells critical for innate immunity. Although cyclin-dependent kinases (CDKs) are typically related to cell cycle progression, increasing evidence has shown that they regulate essential functions of neutrophils. This review highlights the roles of CDKs and their partners, cyclins, in neutrophils, outside of cell cycle regulation. CDK1-10 and several cyclins are expressed in neutrophils, albeit at different levels. Observed phenotypes associated with specific inhibition or genetic loss of CDK2 indicate its role in modulating neutrophil migration. CDK4 and 6 regulate neutrophil extracellular traps (NETs) formation, while CDK5 regulates neutrophil degranulation. CDK7 and 9 are critical in neutrophil apoptosis, contributing to inflammation resolution. In addition to the CDKs that regulate mature neutrophil functions, cyclins are essential in hematopoiesis and granulopoiesis. The pivotal roles of CDKs in neutrophils present an untapped potential in targeting CDKs for treating neutrophil-dominant inflammatory diseases and understanding the regulation of the neutrophil life cycle.

The downregulation of type I IFN signaling in G-MDSCs under tumor conditions promotes their development towards an immunosuppressive phenotype

Tumors modify myeloid cell differentiation and induce an immunosuppressive microenvironment. Granulocytic myeloid-derived suppressor cells (G-MDSCs), the main subgroup of myeloid-derived suppressor cells (MDSCs), are immature myeloid cells (IMCs) with immunosuppressive activity and exist in tumor-bearing hosts. The reason why these cells diverge from a normal differentiation pathway and are shaped into immunosuppressive cells remains unclear. Here, we reported that the increase of granulocyte colony-stimulating factor (G-CSF) in mouse serum with tumor progression encouraged G-MDSCs to obtain immunosuppressive traits in peripheral blood through the PI3K-Akt/mTOR pathway. Importantly, we found that downregulation of type I interferon (IFN-I) signaling in G-MDSCs was a prerequisite for their immunosuppressive effects. Suppressor of cytokine signaling (SOCS1), the action of which is dependent on IFN-I signaling, inhibited the activation of the PI3K-Akt/mTOR pathway by directly interacting with Akt, indicating that the differentiation of immunosuppressive G-MDSCs involves a transition from immune activation to immune tolerance. Our study suggests that increasing IFN-I signaling in G-MDSCs may be a strategy for reprograming immunosuppressive myelopoiesis and slowing tumor progression.

Uncoupled biological and chronological aging of neutrophils in cancer promotes tumor progression

Background

Beyond their fundamental role in homeostasis and host defense, neutrophilic granulocytes (neutrophils) are increasingly recognized to contribute to the pathogenesis of malignant tumors. Recently, aging of mature neutrophils in the systemic circulation has been identified to be critical for these immune cells to properly unfold their homeostatic and anti-infectious functional properties. The role of neutrophil aging in cancer remains largely obscure.

Methods

Employing advanced in vivo microscopy techniques in different animal models of cancer as well as utilizing pulse-labeling and cell transfer approaches, various ex vivo/in vitro assays, and human data, we sought to define the functional relevance of neutrophil aging in cancer.

Results

Here, we show that signals released during early tumor growth accelerate biological aging of circulating neutrophils, hence uncoupling biological from chronological aging of these immune cells. This facilitates the accumulation of highly reactive neutrophils in malignant lesions and endows them with potent protumorigenic functions, thus promoting tumor progression. Counteracting uncoupled biological aging of circulating neutrophils by blocking the chemokine receptor CXCR2 effectively suppressed tumor growth.

Conclusions

Our data uncover a self-sustaining mechanism of malignant neoplasms in fostering protumorigenic phenotypic and functional changes in circulating neutrophils. Interference with this aberrant process might therefore provide a novel, already pharmacologically targetable strategy for cancer immunotherapy.

Versatile neutrophil functions in cancer

Neutrophils have historically been considered a singular, terminally-differentiated cell population, replete with pre-formed granules, poised to react quickly, aggressively, and somewhat non-specifically in the face of a microbial challenge or tissue injury. However, in recent years, neutrophil biologists have started revisiting this simplistic conception. Many studies have identified complexities in neutrophil biology, and these findings have led the field to redefine neutrophil heterogeneity from multiple angles including their development and maturation, their tissue location, and their ability to respond to various (pathological) stimuli. In this review, we discuss the importance of this reassessment within the context of cancer. Experimental evidence supports that neutrophil behavior is diverse, context-dependent, and manipulable; cutting-edge technologies have enabled the identification of neutrophil heterogeneity with high resolution and in an unbiased manner, revealing what may be critical underpinnings of these diverse behaviors, and enabling sophisticated computational assessments of specific programs and interactions. We are coming ever closer to delineating a holistic picture of neutrophil heterogeneity and how it may interplay with cancer stage, tumor microenvironment, and therapy. All of this together paints a promising picture when considering how clinical practice may harness the heterogeneity of these cells, for biomarkers or therapeutic approaches, leveraging what we are learning about these powerful and plentiful immune effectors.

Electrochemical measuring of reactive oxygen species levels in the blood to detect ratio of high-density neutrophils, suitable to alarm presence of cancer in suspicious cases

Here for the first time, a real-time electrochemical assay on unprocessed blood was designed to detect the presence of cancer in patients. The system has been based on the recently approved pathway, which indicates that the abundance of immature and mature low-density neutrophils (LDNs) with reduced ROS production in peripheral blood is increased with the presence of active cancer tumors. Reduced ROS/H₂O₂ released from LDNs play the main role in determining the ROS/H₂O₂ levels of peripheral blood. In contrast, HDNs with increased levels of released ROS/H₂O₂ have higher concentrations than LDNs in normal cases. Hence, the reduced level of ROS species in peripheral blood recorded by our carbon nanostructure decorated sensor in less than 30 seconds showed a great pre-warning about the presence of non-treated cancer in patients with suspicious mass who have been sent for further evaluations.

Relevance of Neutrophil Neprilysin in Heart Failure

Significant expression of neprilysin (NEP) is found on neutrophils, which present the transmembrane integer form of the enzyme. This study aimed to investigate the relationship of neutrophil transmembrane neprilysin (mNEP) with disease severity, adverse remodeling, and outcome in HFrEF. In total, 228 HFrEF, 30 HFpEF patients, and 43 controls were enrolled. Neutrophil mNEP was measured by flow-cytometry. NEP activity in plasma and blood cells was determined for a subset of HFrEF patients using mass-spectrometry. Heart failure (HF) was characterized by reduced neutrophil mNEP compared to controls (p < 0.01). NEP activity on peripheral blood cells was almost 4-fold higher compared to plasma NEP activity (p = 0.031) and correlated with neutrophil mNEP (p = 0.006). Lower neutrophil mNEP was associated with increasing disease severity and markers of adverse remodeling. Higher neutrophil mNEP was associated with reduced risk for mortality, total cardiovascular hospitalizations, and the composite endpoint of both (p < 0.01 for all). This is the first report describing a significant role of neutrophil mNEP in HFrEF. The biological relevance of neutrophil mNEP and exact effects of angiotensin-converting-enzyme inhibitors (ARNi) at the neutrophil site have to be determined. However, the results may suggest early initiation of ARNi already in less severe HF disease, where effects of NEP inhibition may be more pronounced.

Pre-metastatic Niche Formation by Neutrophils in Different Organs

Metastasis is a multistep process requiring tumor cell detachment from the primary tumor and migration to secondary target organs through the lymphatic or blood circulatory systems. In certain cancers, specific organs are predisposed to metastases. Metastatic homing to distant organs is orchestrated by the formation of supportive metastatic microenvironment in such organs, called pre-metastatic niche. Formation of pre-metastatic niche depends on the primary tumor-mediated recruitment of bone marrow-derived myeloid cells, including neutrophils. The contribution of neutrophils to the formation of the pre-metastatic niche is recently getting growing attention. Of note, these cells can either stimulate or inhibit metastatic seeding, depending on the activation of these cells. Here, we concentrate on pro-metastatic functions of neutrophils and the mechanisms involved in this process. Pro-tumor neutrophils support the formation of pre-metastatic niche, attract tumor cells, and directly stimulate proliferation of these cells. Moreover, immunosuppressive neutrophils, also called granulocytic MDSC, promote metastatic progression by the inhibition of antitumor T-cells. Altogether, neutrophil pro-tumor properties significantly affect metastatic spread in the host. Here, we provide an up-to-date overview of roles neutrophils play in the regulation of metastatic processes in different organs.

Innate Neutrophil Memory Dynamics in Disease Pathogenesis

Neutrophils, the most abundant leukocytes in circulation and the first responders to infection and inflammation, closely modulate both acute and chronic inflammatory processes. Resting neutrophils constantly patrol vasculature and migrate to tissues when challenges occur. When infection and/or inflammation recede, tissue neutrophils will be subsequently cleaned up by macrophages which collectively contribute to the resolution of inflammation. While most studies focus on the anti-microbial function of neutrophils including phagocytosis, degranulation, and neutrophil extracellular traps (NETs) formation, recent research highlighted additional contributions of neutrophils beyond simply controlling infectious agents. Neutrophils with resolving characteristics may alter the activities of neighboring cells and facilitate inflammation resolution, modulate long-term macrophage and adaptive immune responses, therefore having important impacts on host pathophysiology. The focus of this chapter is to provide an updated assessment of recent progress in the emerging field of neutrophil programming and memory in the context of both acute and chronic diseases.

Landscape of Bone Marrow Metastasis in Human Neuroblastoma Unraveled by Transcriptomics and Deep Multiplex Imaging

While the bone marrow attracts tumor cells in many solid cancers leading to poor outcome in affected patients, comprehensive analyses of bone marrow metastases have not been performed on a single-cell level. We here set out to capture tumor heterogeneity and unravel microenvironmental changes in neuroblastoma, a solid cancer with bone marrow involvement. To this end, we employed a multi-omics data mining approach to define a multiplex imaging panel and developed DeepFLEX, a pipeline for subsequent multiplex image analysis, whereby we constructed a single-cell atlas of over 35,000 disseminated tumor cells (DTCs) and cells of their microenvironment in the metastatic bone marrow niche. Further, we independently profiled the transcriptome of a cohort of 38 patients with and without bone marrow metastasis. Our results revealed vast diversity among DTCs and suggest that FAIM2 can act as a complementary marker to capture DTC heterogeneity. Importantly, we demonstrate that malignant bone marrow infiltration is associated with an inflammatory response and at the same time the presence of immuno-suppressive cell types, most prominently an immature neutrophil/granulocytic myeloid-derived suppressor-like cell type. The presented findings indicate that metastatic tumor cells shape the bone marrow microenvironment, warranting deeper investigations of spatio-temporal dynamics at the single-cell level and their clinical relevance.

Perioperative change in neutrophil count predicts worse survival in esophageal squamous cell carcinoma

Aims: This study aimed to investigate the relationship between perioperative change in neutrophil count and survival of patients with esophageal squamous cell carcinoma. Method: Neutrophil change (Nc) (where Nc = post-surgery neutrophil count - pre-surgery neutrophil count) was counted according to data within 1 week before surgery and 2 weeks after surgery. Patients were divided into two groups, Nc ≥2.60 and Nc <2.60, according to the median of Nc. Results: Multivariate analysis revealed that Nc ≥2.60 was an independent prognostic marker for overall survival. Subgroup analysis suggested that the overall survival of male patients, patients aged ≤60 years, patients without vessel invasion and patients without nerve infiltration was dramatically worse for those with Nc <2.60. Conclusion: Perioperative change in neutrophil count predicts worse survival in esophageal squamous cell carcinoma after surgery.

Comparative Expression Analysis of Innate Immune Markers and Phagocytic Activity in Peripheral Blood of Dogs with Mammary Tumors

Canine innate immune system role in cancer prevention and progression remains poorly understood. It has been revealed that innate immune cells could play a dual role in cancer immunology promoting or inhibiting tumor development and growth. Current immunotherapies target mainly the adaptive anti-tumor response and that may be a reason why they remain ineffective in a majority of patients. It is important to acquire detailed knowledge about innate immune mechanisms to broaden the diagnostic and therapeutic options and employ innate immune cells in anti-cancer therapies. In the present study, 21 female dogs of different breeds and types of spontaneous mammary tumors were investigated. The study aimed to find simple and cheap markers that can be used for preliminary diagnosis, prior to the surgical resection of the tumor. The differences in innate immune cell quantity and function were investigated between female dogs with malignant mammary tumors of epithelial and mesenchymal origin. Flow cytometry was used to evaluate the percentages of CD5+ lymphocytes including CD5low lymphocytes, CD11b integrin expression on leukocytes, phagocytosis, and oxidative burst. The number of CD11b lymphocytes was increased in tumors with epithelial origin compared to the control group. No significant differences were found between the percentages of phagocytic cells neither for granulocytes nor for monocytes. However, the phagocytes of canine patients with tumors of epithelial origin showed increased phagocytosis compared to the control group. The percentages of granulocytes that produced reactive oxygen species (ROS) in response to E.coli and PMA were not altered in patients with malignant tumors compared to control. A statistically significant difference between the number of ROS produced by the single granulocyte was demonstrated only between the group of bitches with epithelial tumors and the control group in case of E. coli stimulation. The obtained results suggest that some innate immune cells may be involved in anti-tumor immune mechanisms and have the potential to be supportive diagnostic markers in canine mammary tumors.

Exploring the longitudinal glioma microenvironment landscape uncovers reprogrammed pro-tumorigenic neutrophils in the bone marrow

Recent multi-omics studies show different immune tumor microenvironment (TME) compositions in glioblastoma (GBM). However, temporal comprehensive knowledge of the TME from initiation of the disease remains sparse. We use Cre recombinase (Cre)-inducible lentiviral murine GBM models to compare the cellular evolution of the immune TME in tumors initiated from different oncogenic drivers. We show that neutrophils infiltrate early during tumor progression primarily in the mesenchymal GBM model. Depleting neutrophils in vivo at the onset of disease accelerates tumor growth and reduces the median overall survival time of mice. We show that, as a tumor progresses, bone marrow-derived neutrophils are skewed toward a phenotype associated with pro-tumorigenic processes. Our findings suggest that GBM can remotely regulate systemic myeloid differentiation in the bone marrow to generate neutrophils pre-committed to a tumor-supportive phenotype. This work reveals plasticity in the systemic immune host microenvironment, suggesting an additional point of intervention in GBM treatment.

Neutrophil Extracellular Trapping Role in Cancer, Metastases, and Cancer-Related Thrombosis: a Narrative Review of the Current Evidence Base

Purpose of Review

Neutrophil extracellular trap (NET) formation is a newly discovered, reactive oxygen species-dependent regulated process, whereby neutrophils degranulate and extrude genetic material, after engulfing various infectious or neoplastic antigens, culminating in a measurable serologic footprint. Recent research has highlighted the involvement of NETs in cancer and cancer-related pathologies. We review the role of NET formation in cancer biology, prognosis and potential therapeutic modulators.

Recent Findings

Elevated NET levels are associated with cancer metastasis and may be modified by some anaesthetic-analgesic techniques during tumour resection surgery. It promotes tumour cell migration, angiogenesis and hypercoagulability. Although there are potential anti-NET formation therapeutics available, their role has not been formally assessed in cancer patients.

Summary

Limited available evidence suggests an association between elevated NET expression and cancer metastasis, but its validity as a prognostic indicator for cancer-related outcomes is inconclusive. Further observational and interventional studies are warranted to comprehend the potential prognostic and therapeutic role of NETs in cancer.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11912-021-01103-0.