Understanding the Multifaceted Role of Neutrophils in Cancer and Autoimmune Diseases

Calculated Tumor-Associated Neutrophils Are Associated with the Tumor−Stroma Ratio and Predict a Poor Prognosis in Advanced Gastric Cancer

The tumor-associated neutrophils (TANs) value and tumor—stroma ratio (TSR) are promising prognostic parameters in the tumor microenvironment. We aimed to evaluate the prognostic role and relationship of TANs and TSR in gastric cancer. Our study comprised 157 patients who underwent gastrectomy for advanced gastric cancer. TANs were assessed by immunohistochemical staining (CD15 and CD66b) and were analyzed with an image analyzer. TANs have been known to have different functional subpopulations of N1 (anti-tumor) and N2 (pro-tumor). We developed “calculated TANs with pro-tumor function (cN2; CD15 minus CD66b)”. The TSR was evaluated using hematoxylin and eosin staining. High-grade CD15-positive, cN2 in the tumor center, and TSR were significantly related to poor disease-free survival (DFS). TSR and cN2 were independent prognostic factors for DFS (hazard ratio (HR) = 2.614; p = 0.001, HR = 3.976; p = 0.002) and cN2 in the tumor center showed a positive correlation with TSR (R = 0.179, p = 0.025). While CD66b stained both N1 and N2, CD15 detected most of N2. Combining both markers revealed a novel cN2, which was an independent marker of poor prognosis. The transformation from N1 to N2 predominantly occurred in the tumor center, and was associated with TSR.

Neutrophil Extracellular Traps in Cancer Therapy Resistance

Neutrophils and their products are increasingly recognized to have a key influence on cancer progression and response to therapy. Their involvement has been shown in nearly every aspect of cancer pathophysiology with growing evidence now supporting their role in resistance to a variety of cancer therapies. Recently, the role of neutrophils in cancer progression and therapy resistance has been further complicated with the discovery of neutrophil extracellular traps (NETs). NETs are web-like structures of chromatin decorated with a variety of microbicidal proteins. They are released by neutrophils in a process called NETosis. NET-dependent mechanisms of cancer pathology are beginning to be appreciated, particularly with respect to tumor response to chemo-, immuno-, and radiation therapy. Several studies support the functional role of NETs in cancer therapy resistance, involving T-cell exhaustion, drug detoxification, angiogenesis, the epithelial-to-mesenchymal transition, and extracellular matrix remodeling mechanisms, among others. Given this, new and promising data suggests NETs provide a microenvironment conducive to limited therapeutic response across a variety of neoplasms. As such, this paper aims to give a comprehensive overview of evidence on NETs in cancer therapy resistance with a focus on clinical applicability.

Low-Density Granulocytes in Immune-Mediated Inflammatory Diseases

Low-density granulocytes (LDGs), a distinct subset of neutrophils that colocalize with peripheral blood mononuclear cells after density gradient centrifugation, have been observed in many immune-mediated diseases. LDGs are considered highly proinflammatory because of enhanced spontaneous formation of neutrophil extracellular traps, endothelial toxicity, and cytokine production. Concomitantly, increased numbers of LDGs are associated with the severity of many immune-mediated inflammatory diseases. Recent studies, with the help of advanced transcriptomic technologies, demonstrated that LDGs were a mixed cell population composed of immature subset and mature subset, and these two subsets showed different pathogenic features. In this review, we summarize the current knowledge on the composition, origin, and pathogenic properties of LDGs in several immune-mediated inflammatory diseases and discuss potential medical interventions targeting LDGs.

Neutrophils, Cancer and Thrombosis: The New Bermuda Triangle in Cancer Research

Spontaneous venous thrombosis is often the first clinical sign of cancer, and it is linked to a worsened survival rate. Traditionally, tumor-cell induced platelet activation has been the main actor studied in cancer-associated-thrombosis. However, platelet involvement alone does not seem to be sufficient to explain this heightened pro-thrombotic state. Neutrophils are emerging as key players in both thrombus generation and cancer progression. Neutrophils can impact thrombosis through the release of pro-inflammatory cytokines and expression of molecules like P-selectin and Tissue Factor (TF) on their membrane and on neutrophil-derived microvesicles. Their role in cancer progression is evidenced by the fact that patients with high blood-neutrophil counts have a worsened prognosis. Tumors can attract neutrophils to the cancer site via pro-inflammatory cytokine secretions and induce a switch to pro-tumoral (or N2) neutrophils, which support metastatic spread and have an immunosuppressive role. They can also expel their nuclear contents to entrap pathogens forming Neutrophil Extracellular Traps (NETs) and can also capture coagulation factors, enhancing the thrombus formation. These NETs are also known to have pro-tumoral effects by supporting the metastatic process. Here, we strived to do a comprehensive literature review of the role of neutrophils as drivers of both cancer-associated thrombosis (CAT) and cancer progression.

The Predictive Role of NLR, d-NLR, MLR, and SIRI in COVID-19 Mortality

(1) Background: Since its discovery, COVID-19 has caused more than 256 million cases, with a cumulative death toll of more than 5.1 million, worldwide. Early identification of patients at high risk of mortality is of great importance in saving the lives of COVID-19 patients. The study aims to assess the utility of various inflammatory markers in predicting mortality among hospitalized patients with COVID-19. (2) Methods: A retrospective observational study was conducted among 108 patients with laboratory-confirmed COVID-19 hospitalized between 1 May 2021 and 31 October 2021 at Municipal Emergency Clinical Hospital of Timisoara, Romania. Blood cell counts at admission were used to obtain NLR, dNLR, MLR, PLR, SII, and SIRI. The association of inflammatory index and mortality was assessed via Kaplan–Maier curves univariate Cox regression and binominal logistic regression. (3) Results: The median age was 63.31 ± 14.83, the rate of in-hospital death being 15.7%. The optimal cutoff for NLR, dNLR, MLR, and SIRI was 9.1, 9.6, 0.69, and 2.2. AUC for PLR and SII had no statistically significant discriminatory value. The binary logistic regression identified elevated NLR (aOR = 4.14), dNLR (aOR = 14.09), and MLR (aOR = 3.29), as independent factors for poor clinical outcome of COVID-19. (4) Conclusions: NLR, dNLR, MLR have significant predictive value in COVID-19 mortality.

Polymorphonuclear Neutrophils and Tumors: Friend or Foe?

Tumor microenvironment (TME) is a dynamic network that apart from tumor cells includes also cells of the immune system, e.g., neutrophils, which are recruited from blood circulation. In TME, neutrophils are strongly implicated in the direct and indirect interactions with tumor cells or other immune cells, and they play roles in both preventing and/or facilitating tumor progression and metastasis. The dual role of neutrophils is determined by their high plasticity and heterogeneity. Analogous to the macrophages, neutrophils can express antitumoral (N1) and protumoral (N2) phenotypes which differ substantially in morphology and function. N1 phenotype characterizes with a high cytotoxic and proinflammatory activities, while N2 phenotype with immunosuppressive and prometastatic properties. The antitumoral effect of neutrophils includes for example the production of reactive oxygen species or proapoptotic molecules. The protumoral action of neutrophils relies on releasing of proangiogenic and prometastatic mediators, immunosuppressive factors, as well as on direct helping tumor cells in extravasation process. This chapter summarizes the heterogeneity of neutrophils in TME, as well as their dual role on tumor cells.

Transcriptional Profiling of Mouse Eosinophils Identifies Distinct Gene Signatures Following Cellular Activation

Eosinophils are multifunctional, evolutionary conserved leukocytes that are involved in a plethora of responses ranging from regulation of tissue homeostasis to host defense and cancer. Eosinophils have been studied mostly in the context of Type 2 inflammatory responses such as those found in allergy. Nonetheless, it is now evident that they participate in Type 1 inflammatory responses and can respond to Type 1 cytokines such as IFN-γ. Recent data suggest that the pleotropic roles of eosinophils are due to heterogeneous responses to environmental cues. Despite this, the activation profile of eosinophils, in response to various stimuli is yet to be defined. To better understand the transcriptional spectrum of eosinophil activation, we exposed eosinophils to Type 1 (e.g. IFN-γ, E. coli) vs. Type 2 (e.g. IL-4) conditions and subjected them to global RNA sequencing. Our analyses show that IL-4, IFN-γ, E. coli and IFN-γ in the presence of E. coli (IFN-γ/E. coli)-stimulated eosinophils acquire distinct transcriptional profiles, which polarize them towards what we termed Type 1 and Type 2 eosinophils. Bioinformatics analyses using Gene Ontology based on biological processes revealed that different stimuli induced distinct pathways in eosinophils. These pathways were confirmed using functional assays by assessing cytokine/chemokine release (i.e. CXCL9, CCL24, TNF-α and IL-6) from eosinophils following activation. In addition, analysis of cell surface markers highlighted CD101 and CD274 as potential cell surface markers that distinguish between Type 1 and Type 2 eosinophils, respectively. Finally, the transcriptome signature of Type 1 eosinophils resembled that of eosinophils that were obtained from mice with experimental colitis whereas the transcriptome signature of Type 2 eosinophils resembled that of eosinophils from experimental asthma. Our data demonstrate that eosinophils are polarized to distinct “Type 1” and “Type 2” phenotypes following distinct stimulations. These findings provide fundamental knowledge regarding the heterogeneity of eosinophils and support the presence of transcriptional differences between Type 1 and Type 2 cells that are likely reflected by their pleotropic activities in diverse disease settings.

Association between serum low-density neutrophils and acute-onset and recurrent Guillain-Barré syndrome

BACKGROUND AND AIM

Guillain-Barré syndrome (GBS) is one of the most common causes of acute flaccid paralysis. A timely assessment of this disease condition and its treatments are of vital importance to patients diagnosed with GBS. The purpose of this study is to investigate the variation trend of neutrophils along with disease courses and assess the prognostic value of serum low-density neutrophils (LDNs) in the acute-onset and recurrence of GBS.

METHODS

A total of 176 GBS patients were recruited. Patients were evaluated with Medical Research Council (MRC) sum score and the Hughes Functional Grading Scale score upon admission. Peripheral blood samples were collected for routine testing. Flow cytometry analysis was performed to identify LDNs. All patients were followed up to collect disease condition data.

RESULTS

The total neutrophil ratios and counts were significantly higher in patients with acute-onset GBS compared to healthy controls (HCs). These counts/ratios decreased during remission and re-elevated in recurrent GBS patients. However, no correlation was observed between the total neutrophil counts/ratios and the MRC sum score. The LDNs collected from different GBS courses were identified using flow cytometry. The counts and ratios were significantly higher in acute-onset GBS and recurrent GBS compared to HCs and patients in remission. The LDN counts/ratios displayed a negative correlation with the MRC sum scores in acute-onset GBS and recurrent GBS.

CONCLUSION

Our findings suggest that LDN counts/ratios are positively correlated with the acute-onset and recurrence of GBS and its severity. Therefore, LDNs might serve as an accessible prognostic indicator for disease progression monitoring.

Anti-PD-1 Therapy with Adjuvant Ablative Fractional Laser Improves Anti-Tumor Response in Basal Cell Carcinomas

Simple Summary

In some mouse models, ablative fractional laser (AFL) enhances the efficacy of anti-programmed cell death1 therapy (aPD-1), which was recently approved for basal cell carcinoma (BCC). In this explorative study, we aimed to assess locally applied AFL as an adjuvant to systemic aPD-1 treatment in a clinically relevant BCC model. BCC-carrying mice received aPD-1 alone, AFL alone, aPD-1+AFL, or no treatment. Both aPD-1 and AFL alone significantly increased survival time relative to the untreated controls, while aPD-1 that had been complemented with AFL further promoted survival and improved tumor clearance and growth rates. The BCCs were poorly immune infiltrated, but aPD-1 with adjuvant AFL and AFL alone induced substantial immune cell infiltration in tumors and increased the levels of relevant immune cell subtypes. Thus, the anti-tumor response that was generated by aPD-1 with adjuvant AFL may potentially be promoted by increased immune activity in tumors. In conclusion, the use of a local AFL adjuvant to systemic aPD-1 therapy could hold substantial promise for BCC treatment.

Abstract

The efficacy of anti-programmedcelldeath1therapy (aPD-1), which was recently approved for basal cell carcinoma (BCC) treatment, can be enhanced by adjuvant ablative fractional laser (AFL) in syngeneic murine tumor models. In this explorative study, we aimed to assess locally applied AFL as an adjuvant to systemic aPD-1 treatment in a clinically relevant autochthonous BCC model. BCC tumors (n = 72) were induced in Ptch1^+/−K14-CreER2p53^fl/fl-mice (n = 34), and the mice subsequently received aPD-1 alone, AFL alone, aPD-1+AFL, or no treatment. The outcome measures included mouse survival time, tumor clearance, tumor growth rates, and tumor immune infiltration. Both aPD-1 and AFL alone significantly increased survival time relative to untreated controls (31 d and 34.5 d, respectively vs. 14 d, p = 0.0348–0.0392). Complementing aPD-1 with AFL further promoted survival (60 d, p = 0.0198 vs. aPD-1) and improved tumor clearance and growth rates. The BCCs were poorly immune infiltrated, but aPD-1 with adjuvant AFL and AFL alone induced substantial immune cell infiltration in the tumors. Similar to AFL alone, combined aPD-1 and AFL increased neutrophil counts (4-fold, p = 0.0242), the proportion of MHCII-positive neutrophils (p = 0.0121), and concordantly, CD4⁺ and CD8⁺ T-cell infiltration (p = 0.0061–0.0242). These descriptive results suggest that the anti-tumor response that is generated by aPD-1 with adjuvant AFL is potentially promoted by increased neutrophil and T-cell engraftment in tumors. In conclusion, local AFL shows substantial promise as an adjuvant to systemic aPD-1 therapy in a clinically relevant preclinical BCC model.

The Functional Role of IgA in the IgM/IgA-Enriched Immunoglobulin Preparation Trimodulin

In comparison to human immunoglobulin (Ig) G, antibodies of IgA class are not well investigated. In line with this, the functional role of the IgA component in IgM/IgA-enriched immunoglobulin preparations is also largely unknown. In recent years, powerful anti-pathogenic and immunomodulatory properties of human serum IgA especially on neutrophil function were unraveled. Therefore, the aim of our work is to investigate functional aspects of the trimodulin IgA component, a new plasma-derived polyvalent immunoglobulin preparation containing ~56% IgG, ~23% IgM and ~21% IgA. The functional role of IgA was investigated by analyzing the interaction of IgA with FcαRI, comparing trimodulin with standard intravenous IgG (IVIG) preparation and investigating Fc receptor (FcR)-dependent functions by excluding IgM-mediated effects. Trimodulin demonstrated potent immunomodulatory, as well as anti-pathogenic effects in our neutrophil model (neutrophil-like HL-60 cells). The IgA component of trimodulin was shown to induce a strong FcαRI-dependent inhibitory immunoreceptor tyrosine-based activation motif (ITAMi) signaling, counteract lipopolysaccharide-induced inflammation and mediate phagocytosis of Staphylococcus aureus. The fine-tuned balance between immunomodulatory and anti-pathogenic effects of trimodulin were shown to be dose-dependent. Summarized, our data demonstrate the functional role of IgA in trimodulin, highlighting the importance of this immunoglobulin class in immunoglobulin therapy.

Guidelines for the use of flow cytometry and cell sorting in immunological studies (third edition)

The third edition of Flow Cytometry Guidelines provides the key aspects to consider when performing flow cytometry experiments and includes comprehensive sections describing phenotypes and functional assays of all major human and murine immune cell subsets. Notably, the Guidelines contain helpful tables highlighting phenotypes and key differences between human and murine cells. Another useful feature of this edition is the flow cytometry analysis of clinical samples with examples of flow cytometry applications in the context of autoimmune diseases, cancers as well as acute and chronic infectious diseases. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid. All sections are written and peer-reviewed by leading flow cytometry experts and immunologists, making this edition an essential and state-of-the-art handbook for basic and clinical researchers.

Circulating low density neutrophils of breast cancer patients are associated with their worse prognosis due to the impairment of T cell responses

Neutrophils are prominent immune components of tumors, having either anti-tumor (N1) or pro-tumor activity (N2). Circulating neutrophils, divided into high density neutrophils (HDN) and low density neutrophils (LDN), functionally mirror those N1 and N2 cells, respectively. LDN are rare in non-pathological conditions, but frequent in cancer, exhibiting a pro-tumor phenotype. These findings have been mainly demonstrated in animal models, thus proper validation in humans is still imperative. Here, we observed that LDN were increased in the blood of breast cancer (BC) patients, particularly with metastatic disease. Within the population of non-metastatic patients, LDN were more prevalent in patients with poor response to neoadjuvant chemotherapy than patients with a good response. The higher incidence of LDN in BC patients with severe disease or resistance to treatment can be explained by their pro-tumor/immunosuppressive characteristics. Moreover, the percentage of LDN in BC patients’ blood was negatively correlated with activated cytotoxic T lymphocytes and positively correlated with immunosuppressive regulatory T cells. The ability of LDN to spoil anti-tumor immune responses was further demonstrated ex vivo. Hence, this study reveals the potential of LDN as a biomarker of BC response to treatment and opens new avenues for developing new immunotherapies.

The Role of the Innate Immune System in Cancer Dormancy and Relapse

Metastatic spread and recurrence are intimately linked to therapy failure, which remains an overarching clinical challenge for patients with cancer. Cancer cells often disseminate early in the disease process and can remain dormant for years or decades before re-emerging as metastatic disease, often after successful treatment. The interactions of dormant cancer cells and their metastatic niche, comprised of various stromal and immune cells, can determine the length of time that cancer cells remain dormant, as well as when they reactivate. New studies are defining how innate immune cells in the primary tumor may be corrupted to help facilitate many aspects of dissemination and re-emergence from a dormant state. Although the scientific literature has partially shed light on the drivers of immune escape in cancer, the specific mechanisms regulating metastasis and dormancy in the context of anti-tumor immunity are still mostly unknown. This review follows the journey of metastatic cells from dissemination to dormancy and the onset of metastatic outgrowth and recurrent tumor development, with emphasis on the role of the innate immune system. To this end, further research identifying how immune cells interact with cancer cells at each step of cancer progression will pave the way for new therapies that target the reactivation of dormant cancer cells into recurrent, metastatic cancers.

Breast cancer resistance mechanisms: challenges to immunotherapy

PURPOSE

The clinical implementation of immunotherapy has profoundly transformed cancer treatment. Targeting the immune system to mount anti-tumor responses can elicit a systemically durable response. Employing immune checkpoint blockade (ICB) has suppressed tumor growth and vastly improved patient overall and progression-free survival in several cancer types, most notably melanoma and non-small cell lung carcinoma. Despite widescale clinical success, ICB response is heterogeneously efficacious across tumor types. Many cancers, including breast cancer, are frequently refractory to ICB. In this review, we will discuss the challenges facing immunotherapy success and address the underlying mechanisms responsible for primary and acquired breast cancer resistance to immunotherapy.

FINDINGS

Even in initially ICB-responsive tumors, many acquire resistance due to tumor-specific alterations, loss of tumor-specific antigens, and extrinsic mechanisms that reshape the immune landscape within the tumor microenvironment (TME). The tumor immune interaction circumvents the benefits of immunotherapy; tumors rewire the tumor-suppressive functions of activated immune cells within their stroma to propagate tumor growth and progression.

CONCLUSIONS

The breast cancer immune TME is complex and the mechanisms driving resistance to ICB are multifaceted. Continued study in both preclinical models and clinical trials should help elucidate these mechanisms so they can be targeted to benefit more breast cancer patients.

Metabolic Rewiring in the Tumor Microenvironment to Support Immunotherapy: A Focus on Neutrophils, Polymorphonuclear Myeloid-Derived Suppressor Cells and Natural Killer Cells

Leukocytes often undergo rapid changes in cell phenotype, for example, from a resting to an activated state, which places significant metabolic demands on the cell. These rapid changes in metabolic demand need to be tightly regulated to support immune cell effector functions during the initiation and downregulation of an immune response. Prospects for implementing cancer immunotherapy also rest on the idea of optimizing the metabolic profile of immune cell effectors. Here, we examine this issue by focusing on neutrophils and NK cells as cells of increasing interest in cancer immunology and tumor immunometabolism, because they can be targeted or, in the case of NK, used as effectors in immunotherapy. In addition, neutrophils and NK cells have been shown to functionally interact. In the case of neutrophils, we also extended our interest to polymorphonuclear MDSC (PMN-MDSCs), since the granulocytic subset of MDSCs share many phenotypes and are functionally similar to pro-tumor neutrophils. Finally, we reviewed relevant strategies to target tumor metabolism, focusing on neutrophils and NK cells.

Control of innate immune response by biomaterial surface topography, energy, and stiffness

As the focus of implantable biomaterials has shifted from bioinert implants to bioactive designs, recent research has highlighted the complex interactions between cell physiologic systems and material properties, particularly physical cues. From the cells known to interact with implanted biomaterials, the response of the immune system has been a critical target of study recently. Here, we review studies characterizing the response of innate immune cells to various material cues, particularly of those at the surface of implanted materials.The innate immune system consists of cell types with various roles in inflammation. Neutrophils and macrophages serve both phagocytic and signaling roles, especially early in the inflammatory phase of biomaterial implantation. These cell types ultimately dictate the outcome of implants as chronic inflammation, fibrosis, or integration. Other cell types like dendritic cells, mast cells, natural killer cells, and innate lymphoid cells may also serve an immunomodulatory role in the biomaterial context. This review highlights recent advances in our understanding of the role of innate immunity in the response to implantable biomaterials as well as key mechanobiological findings in innate immune cells underpinning these advances. STATEMENT OF SIGNIFICANCE: This review highlights recent advances in the understanding of the role of innate immunity in the response to implantable biomaterials, especially in neutrophils and macrophages, as well as key mechanobiological findings in innate immune cells underpinning these advances. Here we discuss how physicochemical properties of biomaterials control innate immune cell behavior.

Estrogen markedly reduces circulating low-density neutrophils and enhances pro-tumoral gene expression in neutrophil of tumour-bearing mice

Background

Neutrophils are important for immune surveillance of tumour cells. Neutrophils may also be epigenetically programmed in the tumour microenvironment to promote tumour progression. In addition to the commonly known high-density neutrophils (HDN) based on their separation on density gradient, recent studies have reported the presence of high levels of low-density neutrophils (LDN) in tumour-bearing mice and cancer patients. We reported previously that estrogen promotes the growth of estrogen receptor α-negative mammary tumours in mice undergoing mammary involution through stimulating pro-tumoral activities of neutrophils in the mammary tissue.

Methods

Female BALB/cAnNTac mice at 7–8 weeks old were mated and bilateral ovariectomy was performed 2 days post-partum. At 24 h after forced-weaning of pups to induce mammary involution, post-partum female mice were injected with either E2V, or vehicle control on alternative days for 2-weeks. On 48 h post-weaning, treated female mice were inoculated subcutaneously with 4 T1-Luc2 cells into the 9th abdominal mammary gland. Age-matched nulliparous female was treated similarly. Animals were euthanized on day 14 post-tumour inoculation for analysis. To evaluate the short-term effect of estrogen, post-partum females were treated with only one dose of E2V on day 12 post-tumour inoculation.

Results

Estrogen treatment for 2-weeks reduces the number of blood LDN by more than 10-fold in tumour-bearing nulliparous and involuting mice, whilst it had no significant effect on blood HDN. The effect on tumour-bearing mice is associated with reduced number of mitotic neutrophils in the bone marrow and increased apoptosis in blood neutrophils. Since estrogen enhanced tumour growth in involuting mice, but not in nulliparous mice, we assessed the effect of estrogen on the gene expression associated with pro-tumoral activities of neutrophils. Whilst 48 h treatment with estrogen had no effect, 2-weeks treatment significantly increased the expression of Arg1, Il1b and Tgfb1 in both HDN and LDN of involuting mice. In contrast, estrogen increased the expression of Arg1 and Ccl5 in HDN and LDN of nulliparous mice.

Conclusions

Prolonged estrogenic stimulation in tumour-bearing mice markedly hampered tumour-associated increase of LDN plausibly by inhibiting their output from the bone marrow and by shortening their life span. Estrogen also alters the gene expression in neutrophils that is not seen in tumour-free mice. The results imply that estrogen may significantly influence the tumour-modulating activity of blood neutrophils.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08751-2.

Cooperation Between Cancer and Fibroblasts in Vascular Mimicry and N2-Type Neutrophil Recruitment via Notch2-Jagged1 Interaction in Lung Cancer

Background

Angiogenesis is required for tumor development and metastasis, which is a major part in a pro-tumor microenvironment. Vascular mimicry (VM) is a process in which cancer cells, rather than endothelia, create an alternative perfusion system to support the tumor progression.

Objectives

To validate the role of VM and to develop a strategy to inhibit angiogenesis in lung cancer.

Methods

In this study, we utilized lung cancer samples to verify the existence of VM and conducted several experimental methods to elucidate the molecular pathways.

Results

H1299 and CL1-0 lung cancer cells were unable to form capillary-like structures. VM formation was induced by cancer-associated fibroblast (CAFs) in both in vitro and in vivo experiments. Notch2–Jagged1 cell–cell contact between cancer cells and CAFs contributes to the formation of VM networks, supported by Notch intracellular domain (NICD) 2 nuclear translocation and N2ICD target gene upregulated in lung cancer cells mixed with CAFs. The polarization of tumor-promoting N2-type neutrophil was increased by VM networks consisting of CAF and cancer cells. The intravasation of cancer cells and N2-type neutrophils were increased because of the loose junctions of VM. Disruption of cancer cell–CAF connections by a γ‐secretase inhibitor enforced the anticancer effect of anti‐vascular endothelial growth factor antibodies in a mouse model.

Conclusion

This study provides the first evidence that CAFs induce lung cancer to create vascular-like networks. These findings suggest a therapeutic opportunity for improving antiangiogenesis therapy in lung cancer.

The Enigma of Low-Density Granulocytes in Humans: Complexities in the Characterization and Function of LDGs during Disease

Low-density granulocytes (LDGs) have been characterized as important immune cells during healthy and disease states in humans, including microbial infections, cancer, and autoimmune dysfunction. However, the classification of this cell type is similar to other immune cells (e.g., neutrophils, myeloid-derived suppressor cells) and ambiguous functional standards have rendered LDG identification and isolation daunting. Furthermore, most research involving LDGs has mainly focused on adult cells and subjects, leaving increased uncertainty surrounding younger populations, especially in vulnerable neonatal groups where LDG numbers are elevated. This review aims to bring together the current research in the field of LDG biology in the context of immunity to disease, with a focus on infection. In addition, we propose to highlight the gaps in the field that, if filled, could improve upon isolation techniques and functional characterizations for LDGs separate from neutrophils and myeloid-derived suppressor cells (MDSCs). This will not only enhance understanding of LDGs during disease processes and how they differ from other cell types but will also aid in the interpretation of comparative studies and results with the potential to inform development of novel therapeutics to improve disease states in patients.

Predicting disease progression in advanced non-small cell lung cancer with circulating neutrophil-derived and platelet-derived microparticles

BACKGROUND

Microparticles (MPs) are extracellular vesicles that are associated with cancer development and progression. Advanced non-small cell lung cancer (NSCLC) still shows disease progression after multiple lines of treatment. Therefore, the objective of this study was to explore the correlation between circulating MPs and disease progression in advanced NSCLC, and to find a new method for concise and rapid determination of disease progression.

METHODS

Patients with advanced NSCLC admitted to hospital between October 2019 and October 2020 were included and divided into objective remission (OR) and progressive disease (PD) groups. The morphology of MPs was observed using transmission electron microscopy. The circulating total MPs, neutrophil MPs (NMPs), and platelet MPs (PMPs) before and after treatment were detected by flow cytometry, and a predictive model for disease progression in advanced NSCLC was developed.

RESULTS

Eighty-six patients were included; 60 in the OR group and 26 in the PD group. There was no significant difference in total MPs, NMPs, or PMPs at baseline between the two groups. After treatment, total MPs, NMPs, and PMPs were significantly higher in the PD than those in the OR group. Multivariate regression analysis showed that post-treatment NMPs≥160 events/μL(OR,3.748;95%CI,1.147-12.253,p = 0.029), PMPs≥80 events/μL(OR,10.968;95%CI,2.973-40.462,p < 0.0001) and neutrophil/lymphocyte ratio (NLR) ≥3.3 (OR,4.929;95%CI,1.483-16.375,p = 0.009) were independently associated with progression of advanced NSCLC. Post-treatment NMPs and PMPs combined with NLR were used to build a predictive model for progression of advanced NSCLC. The area under the curve was 0.825 (95%CI,0.715-0.934, p < 0.0001), optimal cut-off value was 16, sensitivity was 80.8%, and specificity was 88.3%.

CONCLUSION

NMPs and PMPs are associated with progression of advanced NSCLC. The predictive model for progression of advanced NSCLC, established combining NMPs, PMPs, and NLR, can screen out 80.8% of patients with PD. This is helpful for real-time accurate, concise and rapid assessment of disease progression and timely adjustment of drug therapy.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR1800020223 . Registered 20 December 2018, http://www.chictr.org.cn/index.aspx .

Neutrophil in the Pancreatic Tumor Microenvironment

Pancreatic ductal adenocarcinoma (PDAC) is a malignancy with a poor prognosis and low survival rates. PDAC is characterized by a fibroinflammatory tumor microenvironment enriched by abundant fibroblasts and a variety of immune cells, contributing to its aggressiveness. Neutrophils are essential infiltrating immune cells in the PDAC microenvironment. Recent studies have identified several cellular mechanisms by which neutrophils are recruited to tumor lesion and promote tumorigenesis. This review summarizes the current understanding of the interplay between neutrophils, tumor cells, and other components in the PDAC tumor microenvironment. The prognosis and therapeutic implications of neutrophils in PDAC are also discussed.

Combined Inhibition of SHP2 and CXCR1/2 Promotes Anti-Tumor T Cell Response in NSCLC

SHP2 inhibitors (SHP2i) alone and in various combinations are being tested in multiple tumors with over-activation of the RAS/ERK pathway. SHP2 plays critical roles in normal cell signaling; hence, SHP2is could influence the tumor microenvironment. We found that SHP2i treatment depleted alveolar and M2-like macrophages, induced tumor-intrinsic CCL5/CXCL10 secretion and promoted B and T lymphocyte infiltration in Kras- and Egfr-mutant non-small cell lung cancer (NSCLC). However, treatment also increased intratumor gMDSCs via tumor-intrinsic, NF-kB-dependent production of CXCR2 ligands. Other RAS/ERK pathway inhibitors also induced CXCR2 ligands and gMDSC influx in mice, and CXCR2 ligands were induced in tumors from patients on KRASG12C-inhibitor trials. Combined SHP2(SHP099)/CXCR1/2(SX682) inhibition depleted a specific cluster of S100a8/9high gMDSCs, generated Klrg1+ CD8+ effector T cells with a strong cytotoxic phenotype but expressing the checkpoint receptor NKG2A, and enhanced survival in Kras- and Egfr-mutant models. Our results argue for testing RAS/ERK pathway/CXCR1/2/NKG2A inhibitor combinations in NSCLC patients.

Immunomodulation: Immunoglobulin Preparations Suppress Hyperinflammation in a COVID-19 Model via FcγRIIA and FcαRI

The rapid spread of SARS-CoV-2 has induced a global pandemic. Severe forms of COVID-19 are characterized by dysregulated immune response and "cytokine storm". The role of IgG and IgM antibodies in COVID-19 pathology is reasonably well studied, whereas IgA is neglected. To improve clinical outcome of patients, immune modulatory drugs appear to be beneficial. Such drugs include intravenous immunoglobulin preparations, which were successfully tested in severe COVID-19 patients. Here we established a versatile in vitro model to study inflammatory as well as anti-inflammatory processes by therapeutic human immunoglobulins. We dissect the inflammatory activation on neutrophil-like HL60 cells, using an immune complex consisting of latex beads coated with spike protein of SARS-CoV-2 and opsonized with specific immunoglobulins from convalescent plasma. Our data clarifies the role of Fc-receptor-dependent phagocytosis via IgA-FcαRI and IgG-FcγR for COVID-19 disease followed by cytokine release. We show that COVID-19 associated inflammation could be reduced by addition of human immunoglobulin preparations (IVIG and trimodulin), while trimodulin elicits stronger immune modulation by more powerful ITAMi signaling. Besides IgG, the IgA component of trimodulin in particular, is of functional relevance for immune modulation in this assay setup, highlighting the need to study IgA mediated immune response.

Emerging and multifaceted role of neutrophils in lung cancer

It has long been recognized that cigarette smoking is a shared risk factor for lung cancer and the debilitating lung disease, chronic obstructive pulmonary disease (COPD). As the severity of COPD increases, so does the risk for developing lung cancer, independently of pack years smoked. Neutrophilic inflammation increases with COPD severity and anti-inflammatories such as non-steroidal anti-inflammatory drugs (NSAIDs) can modulate neutrophil function and cancer risk. This review discusses the biology of tumour associated neutrophils (TANs) in lung cancer, which increase in density with tumour progression, particularly in smokers with non-small cell lung cancer (NSCLC). It is now increasingly recognized that neutrophils are responsive to the tumour microenvironment (TME) and polarize into distinct phenotypes that operate in an anti- (N1) or pro-tumorigenic (N2) manner. Intriguingly, the emergence of the pro-tumorigenic N2 phenotype increases with tumour growth, to suggest that cancer cells and the surrounding stroma can re-educate neutrophils. The neutrophil itself is a potent source of reactive oxygen species (ROS), arginase, proteases and cytokines that paradoxically can exert a potent immunosuppressive effect on lymphocytes including cytotoxic T cells (CTLs). Indeed, the neutrophil to lymphocyte ratio (NLR) is a systemic biomarker that is elevated in lung cancer patients and prognostic for poor survival outcomes. Herein, we review the molecular mechanisms by which neutrophil derived mediators can suppress CTL function. Selective therapeutic strategies designed to suppress pathogenic neutrophils in NSCLC may cooperate with immune checkpoint inhibitors (ICI) to increase CTL killing of cancer cells in the TME.

Immune Responses against Disseminated Tumor Cells

Most cancer-related deaths are a consequence of metastases, a series of linear events, notably the invasion-metastasis cascade. The current understanding of cancer immune surveillance derives from studies in primary tumors, but disseminated cancer cells acquire mutations and, in some cases, appear to progress independently after spreading from primary sites. An early step in this process is micrometastatic dissemination. As such, the equilibrium between the immune system and disseminated cancer cells controls the fate of the cancer. Immune checkpoint inhibitors (ICIs) exhibit significant clinical activity in patients, but the efficacy of ICIs depends on both the tumor and its microenvironment. Data often suggest that disseminated cancer cells are not adequately targeted by the immune system. In this review, we summarize the main basic findings of immune responses against disseminated tumor cells and their organ-specific characteristics. Such studies may provide new directions for cancer immune therapy.

Dynamic roles of neutrophils in post-stroke neuroinflammation

Clinical trials involving the blockage of peripheral inflammatory leukocyte recruitment into the brain have puzzlingly led to either no significant improvement in stroke outcome, or even worsened outcomes and increased mortality, prompting a re-evaluation of our understanding into the neuroinflammatory processes after stroke. Whilst traditionally understood as simple effectors of the innate immune system, emerging research in vascular disease biology has redefined the neutrophil as a specialized and highly specific cell type with dynamic functional capacity. Indeed, emerging experimental evidence indicates that neutrophils display diverse roles in the acute stages of ischemic stroke with the ability to elicit both pro-inflammatory and anti-inflammatory effects. Currently, there is some uncertainty as to whether neutrophil diversity is beneficial or harmful in stroke as their interactions with the resident cells of the brain, such as microglia and neurons, would potentially elicit heterogeneous outcomes. Current treatments for patients with stroke aim to remove the vascular blockage and to restore blood flow, but there are currently no drug treatments for managing the loss of functional brain tissue nor restoration of microglial and neuronal damage. If these hypothesized wound-healing functions of neutrophils can be validated in a stroke setting, promoting the recruitment of this type of neutrophils into the injured brain tissue may form a promising therapeutic target for the majority of stroke patients currently without treatment. In this review, we will provide an update on recent research that has explored neutrophil heterogeneity in the neuroinflammatory cascade after ischemic stroke.

Liver-specific T regulatory type-1 cells program local neutrophils to suppress hepatic autoimmunity via CRAMP

Neutrophils with immunoregulatory properties, also referred to as type-2 neutrophils (N2), myeloid-derived suppressor cells (MDSCs), or tumor-associated neutrophils (TANs), comprise a heterogeneous subset of cells that arise from unknown precursors in response to poorly understood cues. Here, we find that, in several models of liver autoimmunity, pharmacologically induced, autoantigen-specific T regulatory type-1 (TR1) cells and TR1-cell-induced B regulatory (Breg) cells use five immunoregulatory cytokines to coordinately recruit neutrophils into the liver and program their transcriptome to generate regulatory neutrophils. The liver-associated neutrophils from the treated mice, unlike their circulating counterparts or the liver neutrophils of sick mice lacking antigen-specific TR1 cells, are proliferative, can transfer disease protection to immunocompromised hosts engrafted with pathogenic effectors, and blunt antigen-presentation and local autoimmune responses via cathelin-related anti-microbial peptide (CRAMP), a cathelicidin, in a CRAMP-receptor-dependent manner. These results, thus, identify antigen-specific regulatory T cells as drivers of tissue-restricted regulatory neutrophil formation and CRAMP as an effector of regulatory neutrophil-mediated immunoregulation.

Neutrophil-lymphocyte ratio as a marker for disability and activity in multiple sclerosis

BACKGROUND

There is limited data regarding the association of Neutrophil-lymphocyte ratio (NLR) inflammatory marker with multiple sclerosis (MS) disability and activity.

OBJECTIVE

The aim of the present study was to evaluate validity of NLR as an inflammatory marker for MS disability and activity.

METHODS

A case-control study including 140 MS patients and 140 age, sex and body mass index matched healthy controls was performed. All participants were subjected to detailed history taking, complete general and neurological examination, laboratory and radiological investigations. Assessment of disease disability was performed using Expanded Disability Status Scale.

RESULTS

The NLR levels was significantly higher in MS patients compared to the controls and in patients with relapse compared to remission. Logistic regression analyses showed that NLR was significantly associated with disease disability (odds ratio (OR): 2.568; confidence interval (CI): 1.377 - 4.788; P: 0.003) and activity (OR: 3.603; CI: 2.086 - 6.226; P: 0.02). The cutoff value for the NLR to predict MS disability and activity was 3.12.

CONCLUSION

NLR was significantly increased in MS patients compared to controls. The significant association of NLR with MS disability and activity suggest that it could be utilized as a simple, rapid and inexpensive inflammatory marker.

Influence of PTPN22 Allotypes on Innate and Adaptive Immune Function in Health and Disease

Protein tyrosine phosphatase, non-receptor type 22 (PTPN22) regulates a panoply of leukocyte signaling pathways. A single nucleotide polymorphism (SNP) in PTPN22, rs2476601, is associated with increased risk of Type 1 Diabetes (T1D) and other autoimmune diseases. Over the past decade PTPN22 has been studied intensely in T cell receptor (TCR) and B cell receptor (BCR) signaling. However, the effect of the minor allele on PTPN22 function in TCR signaling is controversial with some reports concluding it has enhanced function and blunts TCR signaling and others reporting it has reduced function and increases TCR signaling. More recently, the core function of PTPN22 as well as functional derangements imparted by the autoimmunity-associated variant allele of PTPN22 have been examined in monocytes, macrophages, dendritic cells, and neutrophils. In this review we will discuss the known functions of PTPN22 in human cells, and we will elaborate on how autoimmunity-associated variants influence these functions across the panoply of immune cells that express PTPN22. Further, we consider currently unresolved questions that require clarification on the role of PTPN22 in immune cell function.

The longitudinal relationship between immune cell profiles and frailty in patients with breast cancer receiving chemotherapy

BACKGROUND

Frailty is associated with an increased risk of chemotherapy toxicity. Cellular markers of inflammation can help identify patients with frailty characteristics. However, the role of cellular markers of inflammation in identifying patients at risk of developing chemotherapy-induced frailty and their clinical utility are not fully understood.

METHODS

This study was a secondary analysis of a large nationwide cohort study of women with stage I-IIIC breast cancer (n = 581, mean age 53.4; range 22-81). Measures were completed pre-chemotherapy (T1), post-chemotherapy (T2), and 6 months post-chemotherapy (T3). Frailty was assessed at all three time points using a modified Fried score consisting of four self-reported measures (weakness, exhaustion, physical activity, and walking speed; 0-4, 1 point for each). Immune cell counts as well as neutrophil to lymphocyte ratio (NLR) and lymphocyte to monocyte ratio (LMR) were obtained at T1 and T2 time points. Separate linear regressions were used to evaluate the associations of (1) cell counts at T1 with frailty at T1, T2, and T3 and (2) change in cell counts (T2-T1) with frailty at T2 and T3. We controlled for relevant covariates and frailty at the T1 time point.

RESULTS

From T1 to T2, the mean frailty score increased (1.3 vs 2.0; p < 0.01) and returned to T1 levels by the T3 time point (1.3 vs 1.3; p = 0.85). At the T1 time point, there was a positive association between cellular markers of inflammation and frailty: WBC (β = 0.04; p < 0.05), neutrophils (β = 0.04; p < 0.05), and NLR (β = 0.04; p < 0.01). From T1 to T2, a greater increase in cellular markers of inflammation was associated with frailty at T2 (WBC: β = 0.02, p < 0.05; neutrophils: β = 0.03, p < 0.05; NLR: β = 0.03; p < 0.01). These associations remained significant after controlling for the receipt of growth factors with chemotherapy and the time between when laboratory data was provided and the start or end of chemotherapy.

CONCLUSIONS

In patients with breast cancer undergoing chemotherapy, cellular markers of inflammation are associated with frailty. Immune cell counts may help clinicians identify patients at risk of frailty during chemotherapy.

TRIAL REGISTRATION

ClinicalTrials.gov , NCT01382082.

Predictive value of the neutrophil to lymphocyte ratio for disease deterioration and serious adverse outcomes in patients with COVID-19: a prospective cohort study

BACKGROUND

Early identification of patients who are at high risk of poor clinical outcomes is of great importance in saving the lives of patients with novel coronavirus disease 2019 (COVID-19) in the context of limited medical resources.

OBJECTIVE

To evaluate the value of the neutrophil to lymphocyte ratio (NLR), calculated at hospital admission and in isolation, for the prediction of the subsequent presence of disease progression and serious clinical outcomes (e.g., shock, death).

METHODS

We designed a prospective cohort study of 352 hospitalized patients with COVID-19 between January 9 and February 26, 2020, in Yichang City, Hubei Province. Patients with an NLR equal to or higher than the cutoff value derived from the receiver operating characteristic curve method were classified as the exposed group. The primary outcome was disease deterioration, defined as an increase of the clinical disease severity classification during hospitalization (e.g., moderate to severe/critical; severe to critical). The secondary outcomes were shock and death during the treatment.

RESULTS

During the follow-up period, 51 (14.5%) patients' conditions deteriorated, 15 patients (4.3%) had complicated septic shock, and 15 patients (4.3%) died. The NLR was higher in patients with deterioration than in those without deterioration (median: 5.33 vs. 2.14, P < 0.001), and higher in patients with serious clinical outcomes than in those without serious clinical outcomes (shock vs. no shock: 6.19 vs. 2.25, P < 0.001; death vs. survival: 7.19 vs. 2.25, P < 0.001). The NLR measured at hospital admission had high value in predicting subsequent disease deterioration, shock and death (all the areas under the curve > 0.80). The sensitivity of an NLR ≥ 2.6937 for predicting subsequent disease deterioration, shock and death was 82.0% (95% confidence interval, 69.0 to 91.0), 93.3% (68.0 to 100), and 92.9% (66.0 to 100), and the corresponding negative predictive values were 95.7% (93.0 to 99.2), 99.5% (98.6 to 100) and 99.5% (98.6 to 100), respectively.

CONCLUSIONS

The NLR measured at admission and in isolation can be used to effectively predict the subsequent presence of disease deterioration and serious clinical outcomes in patients with COVID-19.

Modulation of immune-inflammatory responses through surface modifications of biomaterials to promote bone healing and regeneration

Control of inflammation is indispensable for optimal oral wound healing and tissue regeneration. Several biomaterials have been used to enhance the regenerative outcomes; however, the biomaterial implantation can ensure an immune-inflammatory response. The interface between the cells and the biomaterial surface plays a critical role in determining the success of soft and hard tissue regeneration. The initial inflammatory response upon biomaterial implantation helps in tissue repair and regeneration, however, persistant inflammation impairs the wound healing response. The cells interact with the biomaterials through extracellular matrix proteins leading to protein adsorption followed by recruitment, attachment, migration, and proliferation of several immune-inflammatory cells. Physical nanotopography of biomaterials, such as surface proteins, roughness, and porosity, is crucial for driving cellular attachment and migration. Similarly, modification of scaffold surface chemistry by adapting hydrophilicity, surface charge, surface coatings, can down-regulate the initiation of pro-inflammatory cascades. Besides, functionalization of scaffold surfaces with active biological molecules can down-regulate pro-inflammatory and pro-resorptive mediators' release as well as actively up-regulate anti-inflammatory markers. This review encompasses various strategies for the optimization of physical, chemical, and biological properties of biomaterial and the underlying mechanisms to modulate the immune-inflammatory response, thereby, promoting the tissue integration and subsequent soft and hard tissue regeneration potential of the administered biomaterial.

Tumor-Derived Extracellular Vesicles and the Immune System-Lessons From Immune-Competent Mouse-Tumor Models

Tumor-derived extracellular vesicles (TEVs) are important regulators of the immune response in cancer; however, most research so far has been carried out using cell culture systems. Immune-competent murine tumor models currently provide the best platform to assess proposed roles of TEVs using in vivo animal models and therefore are important for examining interactions between TEVs and the immune system. In this review, we present the current knowledge on TEVs using in vivo tumor-bearing animal models, with a focus on the role of TEVs in mediating crosstalk between tumor cells and both adaptive and innate immune cells. In particular, we address the question how animal models can clarify the reported heterogeneity of TEV effects in both anti-tumor responses and evasion of immune surveillance. The potential of TEVs in mediating direct antigen-presenting functions supports their potential as cancer vaccine therapeutics, therefore, we provide an overview of key findings of TEV trials that have the potential as novel immunotherapies, and shed light on challenges in the path toward the first in-human trials. We also highlight the important updates on the methods that continue to enhance the rigor and reproducibility of EV studies, particularly in functional animal models.

Interleukin-8 Receptor 2 (IL-8R2)-Deficient Mice Are More Resistant to Pulmonary Coccidioidomycosis than Control Mice

The pathology of human coccidioidomycosis is granulomatous inflammation with many neutrophils surrounding ruptured spherules, but the chemotactic pathways that draw neutrophils into the infected tissues are not known. We previously showed that formalin-killed spherules (FKS) stimulate mouse macrophages to secret macrophage inflammatory protein 2 (MIP-2), which suggested that CXC ELR+ chemokines might be involved in neutrophil recruitment in vivo To test that hypothesis, we intranasally infected interleukin-8R2 (IL-8R2) (Cxcr2)-deficient mice on a BALB/c background with Coccidioides immitis RS. IL-8R2-deficient mice had fewer neutrophils in infected lungs than controls, but unexpectedly the IL-8R2-deficient mice had fewer organisms in their lungs than the control mice. Infected IL-8R2-deficient mouse lungs had higher expression of genes associated with lymphocyte activation, including the Th1 and Th17-related cytokines Ifnγ and Il17a and the transcription factors Stat1 and Rorc Additionally, bronchial alveolar lavage fluid from infected IL-8R2-deficient mice contained more IL-17A and interferon-γ (IFN-γ). We postulate that neutrophils in the lung directly or indirectly interfere with the development of a protective Th1/Th17 immune response to C. immitis at the site of infection.

Single-cell RNA-Seq revealed profound immune alteration in the peripheral blood of patients with bacterial infection

OBJECTIVES

Bacterial infection remains one of the greatest threats to human health. However, how human hosts respond to bacterial infection has not been thoroughly understood. Better understanding of this response will improve human health.

METHODS

Here, we conducted an investigation on host response to bacterial infection using unperturbed clinical samples and single-cell RNA-Seq (scRNA-Seq) technology. To evaluate immune alteration upon bacterial infection in scRNA-Seq data of peripheral blood mononuclear cells (PBMCs), we developed a barcode analytical framework named PBMCode.

RESULTS

Using this PBMCode framework, we revealed profound immune alteration in peripheral blood under bacterial infection, including the emergence of natural killer T (NKT) cell cluster, reduction of B cell population, and considerable changes in T cells and monocytes. In addition, we also observed a large quantity of low-density neutrophils.

CONCLUSIONS

Our investigation on single cells provided unprecedented details in the alteration of both cell population and cell state under bacterial infection. These findings may be relevant to clinical decisions. The complexity of host response to bacterial infection revealed by scRNA-Seq deserves further attention in future studies.

GJA1 is a Prognostic Biomarker and Correlated with Immune Infiltrates in Colorectal Cancer

Purpose

Previous studies found that gap junction alpha-1 protein (GJA1) was a potent tumor suppressor in colorectal cancer (CRC). We designed the present study to evaluate the clinical importance and molecular mechanisms of GJA1 in CRC.

Methods

Clinical and transcriptomic data from TCGA and GEO datasets were retrospectively collected. CRC patients were divided into two subgroups according to the expression level of GJA1 mRNA. Difference between survival time and response to neoadjuvant chemotherapy was then evaluated. Functional assays including wound-healing assay, transwell invasion assay and flow cytometry assay were performed to investigate the effects of GJA1 on invasive ability and response to chemotherapy drugs of CRC cells. Moreover, we explored the mechanisms of GJA1 by which it regulates CRC malignant phenotypes.

Results

The expression level of GJA1 was significantly higher in normal tissue than cancer tissue, indicating a tumor suppressive role of GJA1 in CRC. Patients with higher expression of GJA1 showed better prognosis than those with low GJA1 expression level. Consistently, overexpression of GJA1 suppressed the invasive ability of CRC cells while enhancing the sensitivity of CRC cells to oxaliplatin-induced apoptosis. Mechanically, we found that GJA1 suppressed the epithelial mesenchymal transition process. Moreover, GJA1 could modulating infiltrating levels of several immune cells in the tumor microenvironment.

Conclusion

These findings suggested that GJA1 was correlated with prognosis and immune infiltrating levels of CD8+ T cells, macrophages, neutrophils, and DCs in CRC. In addition, GJA1 expression contributes to regulation of tumor-associated macrophages (TAMs) and tumor infiltrating neutrophils (TINs) in CRC. These findings suggest that GJA1 is a promising biomarker for determining prognosis and immune infiltration in colorectal cancer.

Stabilization of Human Whole Blood Samples for Multicenter and Retrospective Immunophenotyping Studies

Whole blood is often collected for large-scale immune monitoring studies to track changes in cell frequencies and responses using flow (FC) or mass cytometry (MC). In order to preserve sample composition and phenotype, blood samples should be analyzed within 24 h after bleeding, restricting the recruitment, analysis protocols, as well as biobanking. Herein, we have evaluated two whole blood preservation protocols that allow rapid sample processing and long-term stability. Two fixation buffers were used, Phosphoflow Fix and Lyse (BD) and Proteomic Stabilizer (PROT) to fix and freeze whole blood samples for up to 6 months. After analysis by an 8-plex panel by FC and a 26-plex panel by MC, manual gating of circulating leukocyte populations and cytokines was performed. Additionally, we tested the stability of a single sample over a 13-months period using 45 consecutive aliquots and a 34-plex panel by MC. We observed high correlation and low bias toward any cell population when comparing fresh and 6 months frozen blood with FC and MC. This correlation was confirmed by hierarchical clustering. Low coefficients of variation (CV) across studied time points indicate good sample preservation for up to 6 months. Cytokine detection stability was confirmed by low CVs, with some differences between fresh and fixed conditions. Thirteen months regular follow-up of PROT samples showed remarkable sample stability. Whole blood can be preserved for phenotyping and cytokine-response studies provided the careful selection of a compatible antibody panel. However, possible changes in cell morphology, differences in antibody affinity, and changes in cytokine-positive cell frequencies when compared to fresh blood should be considered. Our setting constitutes a valuable tool for multicentric and retrospective studies. © 2020 International Society for Advancement of Cytometry.

The role of plant-derived natural substances as immunomodulatory agents in carcinogenesis

The role of immune system in carcinogenesis represents fundamental events associated with cancer eradication; however, tumor evolution is connected with various mechanisms of tumor evasion and progression of cancer. Based on recent evidence, phytochemicals are directly associated with immunomodulation of the innate and adaptive immunity via different mechanisms of action including stimulation and amplification of immune cells, humoral compartments, and associated molecules. This comprehensive study focuses on immunomodulating potential of phytochemicals (mixture in plants or separately such as individual phytochemical) and their impact on regulation of immune response during cancer development, immune tolerance, and immune escape. Clinical application of phytochemicals as modulators of host immunity against cancer may represent perspective approach in anticancer therapy.

A Proliferation-Inducing Ligand Regulation in Polymorphonuclear Neutrophils by Panax ginseng

A proliferation-inducing ligand (APRIL) is a member of the tumor necrosis factor superfamily that was first identified as a factor favoring tumorigenesis. APRIL is important fitness and survival factors for B cells and plasma cells in the periphery. Considering this, as well as the quantitative predominance of neutrophils among the peripheral blood leukocytes, we carried out the first study assessing the influence of the transforming growth factor (TGF)-β signaling pathway on APRIL expression in these cells. Furthermore, as the Rb1 ginsenoside is known to exhibit multiple pharmacological activities, we verified if the saponin is capable of modulating the process. The present study shows that TGF-β increased the expression of APRIL and the level of phospho-p38, phospho-Akt(T308), and phospho-Akt(S473) in the cytoplasmic fraction, as well as the expression of Fra1, c-Fos, and c-Jun in the nuclear fraction, of neutrophils. However, exposure of these cells to Rb1 reduced the expression and level of the investigated proteins. No changes were found in the expression of APRIL and the level of p-p38 in the cytoplasmic fraction of neutrophils following the application of Rb1 alone, as well as in the neutrophils incubated first with Rb1 and then with TGF-β, whereas a higher level of phosphorylation was observed for Akt and PI3 kinases in the cells. Moreover, a higher expression of all the studied transcription factors was observed in the nuclear fraction of neutrophils. Based on the observed changes, it may be assumed that the expression of APRIL molecule in TGF-β-induced neutrophils and its regulation by Rb1 are associated with PI3K/AKT signaling pathways and transcription factors Fra-1, Fra-2, c-Jun, and c-Fos. Rb1 appears to be a favorable factor that may be potentially used in the modulation of tumor-promoting APRIL expression.

LDGs versus NDGs in patients with oral squamous cell carcinoma (OSCC)

BACKGROUND

The significant role played by neutrophils in cancer biology is indisputable; yet, their subpopulations may exhibit a contrasting role. The phenomenon of polarization of neutrophils and signaling modulators in the course of a neoplastic process has gained increased attention in recent times. The present study's objective was to quantitatively assess low-density neutrophils (LDNs) and normal-density neutrophils (NDNs) populations including IL-17 expression in confrontation with Th17 lymphocytes in patients with oral squamous cell carcinoma (OSCC). The neutrophil to lymphocyte ratio (NLR) biomarker value was determined. Besides, the influence of rhIL-17 on the proliferation level of the squamous cell carcinoma (SCC) malignant line cells was tested.

METHODS

Leukocytes were isolated in the density gradient and the CD16+ population was magnetically sorted. The percentages of neutrophil subpopulations, lymphocyte Th17, and IL-17 expression in the studied cells were determined on a flow cytometer. Squamous cell carcinoma proliferation was assessed with the MTT test.

RESULT

The existence of two populations of human neutrophils was determined: LDNs and NDNs. A higher percentage of LDNs and Th17 was observed with the concomitant lower percentage of NDNs in patients with OSCC as compared with the control group. NLR was elevated in patients with cancer. The highest IL-17 expression was obtained in the LDNs population in these patients. However, no influence of IL-17 on SCC proliferation could be determined.

CONCLUSION

The present study demonstrated a strong relationship between IL-17 concentration and the count of LDNs or Th17 in the course of OSCC, which may serve as a reference point for new therapies. Moreover, the obtained LDNs/NDNs and NLR values in patients with cancer prove their usefulness in diagnostic and prognostic in patients with OSCC.

Interleukin-8: A chemokine at the intersection of cancer plasticity, angiogenesis, and immune suppression

Tumor progression relies on the ability of cancer cells to effectively invade surrounding tissues and propagate. Among the many mechanisms that contribute to tumor progression is the epithelial-to-mesenchymal transition (EMT), a phenotypic plasticity phenomenon that increases the cancer cells' motility and invasiveness and influences their surrounding microenvironment by promoting the secretion of a variety of soluble factors. One such factor is IL-8, a chemokine with multiple pro-tumorigenic roles within the tumor microenvironment (TME), including stimulating proliferation or transformation of tumor cells into a migratory or mesenchymal phenotype. Further, IL-8 can increase tumor angiogenesis or recruit larger numbers of immunosuppressive cells to the tumor. Prognostically, observations in many tumor types show that patients with higher levels of IL-8 at baseline experience worse clinical outcomes. Additionally, studies have shown that the chemokine directly contributes to the development of resistance to both chemotherapy and molecularly targeted agents. More recently, clinical studies evaluating levels of IL-8 in patients receiving immune checkpoint inhibition (ICI) therapy deduced that myeloid tumor infiltration driven by IL-8 contributes to resistance to ICI agents and that peripheral IL-8 can predict outcomes to ICI therapy. Further, pre-clinical data demonstrate that targeting IL-8 or its receptors enables improved tumor killing by immune cells, and treatment strategies combining blockade of the IL-8/IL-8R axis with ICI ultimately improve anti-tumor efficacy. Based on these results and the prognostic capacity of IL-8, there are a number of ongoing clinical trials evaluating the addition of IL-8 targeting strategies to immune-based therapies.

DNA binds to a specific site of the adhesive blood-protein von Willebrand factor guided by electrostatic interactions

Neutrophils release their intracellular content, DNA included, into the bloodstream to form neutrophil extracellular traps (NETs) that confine and kill circulating pathogens. The mechanosensitive adhesive blood protein, von Willebrand Factor (vWF), interacts with the extracellular DNA of NETs to potentially immobilize them during inflammatory and coagulatory conditions. Here, we elucidate the previously unknown molecular mechanism governing the DNA–vWF interaction by integrating atomistic, coarse-grained, and Brownian dynamics simulations, with thermophoresis, gel electrophoresis, fluorescence correlation spectroscopy (FCS), and microfluidic experiments. We demonstrate that, independently of its nucleotide sequence, double-stranded DNA binds to a specific helix of the vWF A1 domain, via three arginines. This interaction is attenuated by increasing the ionic strength. Our FCS and microfluidic measurements also highlight the key role shear-stress has in enabling this interaction. Our simulations attribute the previously-observed platelet-recruitment reduction and heparin-size modulation, upon establishment of DNA–vWF interactions, to indirect steric hindrance and partial overlap of the binding sites, respectively. Overall, we suggest electrostatics—guiding DNA to a specific protein binding site—as the main driving force defining DNA–vWF recognition. The molecular picture of a key shear-mediated DNA–protein interaction is provided here and it constitutes the basis for understanding NETs-mediated immune and hemostatic responses.

Multiple Roles for Chemokines in Neutrophil Biology

Chemokines are recognized as the most critical mediators for selective neutrophil recruitment during inflammatory conditions. Furthermore, they are considered fundamental regulators of neutrophil mobilization from the bone marrow (BM) to the bloodstream and for their homing back at the end of their life for apoptosis and clearance. However, chemokines are also important mediators of neutrophil effector functions including oxidative burst, degranulation, neutrophil extracellular trap (NET)osis, and production of inflammatory mediators. Neutrophils have been historically considered as a homogeneous population. In recent years, several maturation stages and subsets with different phenotypic profiles and effector functions were described both in physiological and pathological conditions such as infections, autoimmunity, and cancer. The aim of this review is to give an overview of the current evidence regarding the role of chemokines and chemokine receptors in neutrophil biology, including their possible role in neutrophil maturation, differentiation, and in defining emerging neutrophil subsets.

The liver fibrosis niche: Novel insights into the interplay between fibrosis-composing mesenchymal cells, immune cells, endothelial cells, and extracellular matrix

Liver fibrosis is a hepatic wound-healing response caused by chronic liver diseases that include viral hepatitis, alcoholic liver disease, non-alcoholic steatohepatitis, and cholestatic liver disease. Liver fibrosis eventually progresses to cirrhosis that is histologically characterized by an abnormal liver architecture that includes distortion of liver parenchyma, formation of regenerative nodules, and a massive accumulation of extracellular matrix (ECM). Despite intensive investigations into the underlying mechanisms of liver fibrosis, developments of anti-fibrotic therapies for liver fibrosis are still unsatisfactory. Recent novel experimental approaches, such as single-cell RNA sequencing and proteomics, have revealed the heterogeneity of ECM-producing cells (mesenchymal cells) and ECM-regulating cells (immune cells and endothelial cells). These approaches have accelerated the identification of fibrosis-specific subpopulations among these cell types. The ECM also consists of heterogenous components. Their production, degradation, deposition, and remodeling are dynamically regulated in liver fibrosis, further affecting the functions of cells responsible for fibrosis. These cellular and ECM elements cooperatively form a unique microenvironment: a fibrotic niche. Understanding the complex interplay between these elements could lead to a better understanding of underlying fibrosis mechanisms and to the development of effective therapies.

Neutrophils in Tuberculosis-Associated Inflammation and Lung Pathology

Protective immunity to Mycobacterium tuberculosis (Mtb)—the causative agent of tuberculosis (TB)—is not fully understood but involves immune responses within the pulmonary airways which can lead to exacerbated inflammation and immune pathology. In humans, this inflammation results in lung damage; the extent of which depends on specific host pro-inflammatory processes. Neutrophils, though increasingly linked to the development of inflammatory disorders, have been less well studied in relation to TB-induced lung pathology. Neutrophils mode of action and their specialized functions can be directly linked to TB-specific lung tissue damage observed on patient chest X-rays at diagnosis and contribute to long-term pulmonary sequelae. This review discusses aspects of neutrophil activity associated with active TB, including the resulting inflammation and pulmonary impairment. It highlights the significance of neutrophil function on TB disease outcome and underlines the necessity of monitoring neutrophil function for better assessment of the immune response and severity of lung pathology associated with TB. Finally, we propose that some MMPs, ROS, MPO, S100A8/A9 and Glutathione are neutrophil-related inflammatory mediators with promising potential as targets for developing host-directed therapies for TB.

Two- and three-color STORM analysis reveals higher-order assembly of leukotriene synthetic complexes on the nuclear envelope of murine neutrophils

Over the last several years it has become clear that higher order assemblies on membranes, exemplified by signalosomes, are a paradigm for the regulation of many membrane signaling processes. We have recently combined two-color direct stochastic optical reconstruction microscopy (dSTORM) with the (Clus-DoC) algorithm that combines cluster detection and colocalization analysis to observe the organization of 5-lipoxygenase (5-LO) and 5-lipoxygenase-activating protein (FLAP) into higher order assemblies on the nuclear envelope of mast cells; these assemblies were linked to leukotriene (LT) C4 production. In this study we investigated whether higher order assemblies of 5-LO and FLAP included cytosolic phospholipase A2 (cPLA2) and were linked to LTB4 production in murine neutrophils. Using two- and three-color dSTORM supported by fluorescence lifetime imaging microscopy we identified higher order assemblies containing 40 molecules (median) (IQR: 23, 87) of 5-LO, and 53 molecules (62, 156) of FLAP monomer. 98 (18, 154) molecules of cPLA2 were clustered with 5-LO, and 77 (33, 114) molecules of cPLA2 were associated with FLAP. These assemblies were tightly linked to LTB4 formation. The activation-dependent close associations of cPLA2, FLAP, and 5-LO in higher order assemblies on the nuclear envelope support a model in which arachidonic acid is generated by cPLA2 in apposition to FLAP, facilitating its transfer to 5-LO to initiate LT synthesis.

Role of the Neutrophil in the Pathogenesis of Advanced Cancer and Impaired Responsiveness to Therapy

Notwithstanding the well-recognized involvement of chronic neutrophilic inflammation in the initiation phase of many types of epithelial cancers, a growing body of evidence has also implicated these cells in the pathogenesis of the later phases of cancer development, specifically progression and spread. In this setting, established tumors have a propensity to induce myelopoiesis and to recruit neutrophils to the tumor microenvironment (TME), where these cells undergo reprogramming and transitioning to myeloid-derived suppressor cells (MDSCs) with a pro-tumorigenic phenotype. In the TME, these MDSCs, via the production of a broad range of mediators, not only attenuate the anti-tumor activity of tumor-infiltrating lymphocytes, but also exclude these cells from the TME. Realization of the pro-tumorigenic activities of MDSCs of neutrophilic origin has resulted in the development of a range of adjunctive strategies targeting the recruitment of these cells and/or the harmful activities of their mediators of immunosuppression. Most of these are in the pre-clinical or very early clinical stages of evaluation. Notable exceptions, however, are several pharmacologic, allosteric inhibitors of neutrophil/MDSC CXCR1/2 receptors. These agents have entered late-stage clinical assessment as adjuncts to either chemotherapy or inhibitory immune checkpoint-targeted therapy in patients with various types of advanced malignancy. The current review updates the origins and identities of MDSCs of neutrophilic origin and their spectrum of immunosuppressive mediators, as well as current and pipeline MDSC-targeted strategies as potential adjuncts to cancer therapies. These sections are preceded by a consideration of the carcinogenic potential of neutrophils.

The complexity of neutrophils in health and disease: Focus on cancer

Neutrophils are essential soldiers of the immune response and their role have long been restricted to their activities in defence against microbial infections and during the acute phase of the inflammatory response. However, increasing number of investigations showed that neutrophils are endowed with plasticity and can participate in the orchestration of both innate and adaptive immune responses. Neutrophils have an impact on a broad range of disorders, including infections, chronic inflammations, and cancer. Neutrophils are present in the tumour microenvironment and have been reported to mediate both pro-tumour and anti-tumour responses. Neutrophils can contribute to genetic instability, tumour cell proliferation, angiogenesis and suppression of the anti-tumour immune response. In contrast, neutrophils are reported to mediate anti-tumour resistance by direct killing of tumour cells or by engaging cooperative interactions with other immune cells. Here we discuss the current understandings of neutrophils biology and functions in health and diseases, with a specific focus on their role in cancer biology and their prognostic significance in human cancer.