IL8, Neutrophils, and NETs in a Collusion against Cancer Immunity and Immunotherapy

Neutrophil extracellular traps in tumor metabolism and microenvironment

Neutrophil extracellular traps (NETs) are intricate, web-like formations composed of DNA, histones, and antimicrobial proteins, released by neutrophils. These structures participate in a wide array of physiological and pathological activities, including immune rheumatic diseases and damage to target organs. Recently, the connection between NETs and cancer has garnered significant attention. Within the tumor microenvironment and metabolism, NETs exhibit multifaceted roles, such as promoting the proliferation and migration of tumor cells, influencing redox balance, triggering angiogenesis, and driving metabolic reprogramming. This review offers a comprehensive analysis of the link between NETs and tumor metabolism, emphasizing areas that remain underexplored. These include the interaction of NETs with tumor mitochondria, their effect on redox states within tumors, their involvement in metabolic reprogramming, and their contribution to angiogenesis in tumors. Such insights lay a theoretical foundation for a deeper understanding of the role of NETs in cancer development. Moreover, the review also delves into potential therapeutic strategies that target NETs and suggests future research directions, offering new perspectives on the treatment of cancer and other related diseases.

Pan-tumor analysis to investigate the obesity paradox in immune checkpoint blockade

BACKGROUND

Obesity is a risk factor for developing cancer but is also associated with improved outcomes after treatment with immune checkpoint inhibitors (ICIs), a phenomenon called the obesity paradox. To interrogate mechanisms of divergent immune responses in obese and non-obese patients, we examined the relationship among obesity status, clinical responses, and immune profiles from a diverse, pan-tumor cohort of patients treated with ICI-based therapy.

METHODS

From June 2021 to March 2023, we prospectively collected serial peripheral blood samples from patients with advanced or metastatic solid tumors who received ICI as standard of care at Johns Hopkins. Patients were stratified by obesity status at treatment initiation, with obesity defined as body mass index (BMI)≥30 at treatment initiation and BMI≥18.5 and <30 considered non-obese; underweight patients (BMI<18.5) were excluded. We evaluated the concentration of 37 cytokines and used cytometry by time of flight to characterize immune cell clusters and cell-surface expression markers at baseline and on-treatment.

RESULTS

We enrolled 94 patients, of whom 30 (32%) were obese and 64 (68%) were non-obese. Compared with non-obese patients, obese patients had superior progression-free survival (HR: 0.44 (95% CI: 0.24 to 0.81), p=0.01) and overall survival (OS) (HR: 0.24 (95% CI: 0.07 to 0.80), p=0.02). Obese patients had lower serum IL-15 levels at treatment baseline and lower on-treatment levels of IL-6, IL-8, and IL-15. Low on-treatment IL-6 was associated with improved OS (HR: 0.27 (95% CI: 0.08 to 0.88), p=0.03), as was low on-treatment IL-8 (HR: 0.19 (95% CI: 0.05 to 0.70), p=0.01). Obese patients demonstrated lower levels of T effector cells with reduced expression of cytotoxicity markers and higher expression of exhaustion markers at baseline and on-treatment.

CONCLUSIONS

Obese and non-obese patients with cancer have divergent immunological responses to ICIs. Obesity is associated with reduced levels of certain inhibitory cytokines and higher expression of T-cell exhaustion markers. ICI-based therapy may more effectively reverse T-cell dysfunction in obese patients, potentially contributing to the paradoxically improved responses in this population.

Metabolic Tumor Volume Assessed by 18F FDG-PET CT Scan as a Predictive Biomarker for Immune Checkpoint Blockers in Advanced NSCLC and Its Biological Correlates

PURPOSE

This study aimed to explore metabolic tumor volume (MTV) as assessed by 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG-PET/CT) and understand its biological meaning in patients with non-small cell lung cancer (NSCLC) exposed to immune checkpoint blockers (ICB).

EXPERIMENTAL DESIGN

In this study, patients with advanced NSCLC and a positive PET scan within 42 days of first-line treatment were enrolled in 11 institutions across four countries. Total MTV (tMTV) was analyzed, with a 42% maximum standardized uptake value threshold. Survival was analyzed according to high tMTV (≥median). Plasma proteomic profile, whole exome, transcriptome, and other analyses were performed on monocentric cohorts to explore its biological correlates.

RESULTS

Of the 518 patients included, 167 received ICBs, 257 had chemotherapy plus ICBs, and 94 had chemotherapy. Median tMTV was 99 cm3. Median overall survival (OS) for patients with high tMTV treated with ICBs was 11.4 vs. 29.6 months (P < 0.0012) for those with low tMTV. In patients who received chemotherapy-ICB, tMTV did not correlate with OS (P = 0.099). In patients with programmed death-ligand 1 (PD-L1) ≥1% and high tMTV, chemotherapy-ICB combination was associated with longer OS compared with ICBs alone (20 vs. 11.4 months; P = 0.026), while no survival differences were observed in the low tMTV group. High tMTV correlated (and its detrimental effect seems to be driven) with a specific proteomic profile and increase in genomic instability.

CONCLUSIONS

Our analysis indicates high tMTV is linked to an increase in systemic inflammation, specific cytokines production, and chromosomal instability. tMTV may serve as one of the biomarkers to select the best upfront strategy in patients with PD-L1-positive advanced NSCLC.

Harnessing the tumor microenvironment: targeted cancer therapies through modulation of epithelial-mesenchymal transition

The tumor microenvironment (TME) is integral to cancer progression, impacting metastasis and treatment response. It consists of diverse cell types, extracellular matrix components, and signaling molecules that interact to promote tumor growth and therapeutic resistance. Elucidating the intricate interactions between cancer cells and the TME is crucial in understanding cancer progression and therapeutic challenges. A critical process induced by TME signaling is the epithelial-mesenchymal transition (EMT), wherein epithelial cells acquire mesenchymal traits, which enhance their motility and invasiveness and promote metastasis and cancer progression. By targeting various components of the TME, novel investigational strategies aim to disrupt the TME's contribution to the EMT, thereby improving treatment efficacy, addressing therapeutic resistance, and offering a nuanced approach to cancer therapy. This review scrutinizes the key players in the TME and the TME's contribution to the EMT, emphasizing avenues to therapeutically disrupt the interactions between the various TME components. Moreover, the article discusses the TME's implications for resistance mechanisms and highlights the current therapeutic strategies toward TME modulation along with potential caveats.

Neutrophil extracellular DNA traps activate the TLR9 signaling pathway of pancreatic ductal epithelial cells in patients with type 2 autoimmune pancreatitis

The presence of neutrophil infiltration around the pancreatic ducts has been found to be associated with type 2 autoimmune pancreatitis (AIP). However, the functional role and clinical significance of neutrophil migration in the progression of pancreatitis is not fully understood. Here, we found that neutrophil extracellular traps (NETs) are abundant around the pancreatic duct in patients with type 2 AIP. We also observed an increased expression of toll-like receptor 9 (TLR9) in pancreatic ductal epithelial cells (HPDEC) in type 2 AIP patients compared to other pancreatic diseases. TLR9 acts as the DNA component of NETs (NET-DNA) receptor in HPDEC, which senses extracellular DNA and subsequently activates the NF-κB pathway to promote neutrophil recruitment and induce NET formation. In addition, our results indicated that the hydroxychloroquine (HCQ), acting as a TLR9 antagonist, could effectively inhibit the activation of inflammatory pathways, reduce neutrophil migration and block the positive feedback loop. The intervention positions HCQ acts as a potential target drug for the clinical treatment of type 2 AIP.

Cancer associated fibroblasts drive epithelial to mesenchymal transition and classical to basal change in pancreatic ductal adenocarcinoma cells with loss of IL-8 expression

Pancreatic ductal adenocarcinoma (PDAC) carries an extremely poor prognosis, in part resulting from cellular heterogeneity that supports overall tumorigenicity. Cancer associated fibroblasts (CAF) are key determinants of PDAC biology and response to systemic therapy. While CAF subtypes have been defined, the effects of patient-specific CAF heterogeneity and plasticity on tumor cell behavior remain unclear. Here, multi-omics was used to characterize the tumor microenvironment (TME) in tumors from patients undergoing curative-intent surgery for PDAC. In these same patients, matched tumor organoid and CAF lines were established to functionally validate the impact of CAFs on the tumor cells. CAFs were found to drive epithelial-mesenchymal transition (EMT) and a switch in tumor cell classificiaton from classical to basal subtype. Furthermore, we identified CAF-specific interleukin 8 (IL-8) as an important modulator of tumor cell subtype. Finally, we defined neighborhood relationships between tumor cell and T cell subsets.

IL-8 Downregulation Mediates the Beneficial Effects of Infection-Induced Fever on Breast Cancer Prognosis

Purpose

Previous studies have reported that infection-induced fever is associated with improved breast cancer prognosis, potentially through the modulation of cytokines. However, the key cytokines and the underlying mechanisms through which fever exerts its anti-tumor effects remain unclear.

Patients and Methods

A total of 794 breast cancer patients were recruited between 2008 and 2017, with follow-up extending until October 31st, 2023. Infection-induced fever was assessed using questionnaires, while a multiplex assay evaluated a panel of 27 cytokines. The mediation effects of various cytokines were analyzed through model-based causal mediation analysis. Additionally, we explored modifications to these mediation effect by examining interactions among the cytokines themselves as well as their interactions with infection-induced fever. Bioinformatic analyses were conducted to elucidate the biological pathways mediating infection-induced fever.

Results

The relationship between infection-induced fever and improved breast cancer prognosis was mediated by a decrease in interleukin-8 (IL-8) levels. Furthermore, our findings revealed that the downregulation of IL-8, which mediates the beneficial effects of fever, was antagonized by IL-2, IL12p70 and IL-7. By intersecting the biological pathways influenced by IL-8, alongside those affected by IL-2, IL12p70, or IL-7, we found that these latter cytokines antagonized the mediation effects of IL-8 via regulating critical pathways such as neutrophil degranulation, extracellular matrix organization and asparagine N-linked glycosylation.

Conclusion

Infection-induced fever may improve breast cancer prognosis through IL-8 downregulation and the mediation mechanisms may be involved in neutrophil degranulation, extracellular matrix organization and asparagine N-linked glycosylation. Such findings not only provide valuable insights into effectively managing febrile responses for breast cancer patients, but also underscore the therapeutic potential of cytokines in breast cancer patients.

GADD45β-MTK1 signaling axis mediates oncogenic stress-induced activation of the p38 and JNK pathways

The ERK pathway governs essential biological processes such as cell proliferation and survival, and its hyperactivation by various oncogenes ultimately drives carcinogenesis. However, normal mammalian cells typically recognize aberrant ERK signaling as oncogenic stress and respond by inducing cell cycle arrest or apoptosis through activation of the p38 and JNK pathways. Despite the critical role of this response in preventing carcinogenesis, the precise molecular mechanisms underlying oncogene-induced, ERK-dependent activation of p38/JNK and its tumor-suppressive effects remain unclear. Here, we demonstrate that MAP three kinase 1 (MTK1), a stress-responsive MAPKKK, serves as a key mediator of p38/JNK activation induced by oncogenic ERK signaling. Mechanistically, aberrant ERK signaling induces sustained expression of the transcription factor early growth response protein 1 (EGR1), which promotes the production of the MTK1 activator GADD45β, leading to persistent activation of MTK1-p38/JNK signaling. Gene knockout and transcriptome analyses revealed that this GADD45β/MTK1-mediated cross-talk between the ERK and p38/JNK pathways preferentially upregulates a specific set of genes involved in apoptosis and the immune response. Notably, the expression of EGR1, GADD45β, and MTK1 is frequently downregulated in many cancers with high ERK activity, resulting in the disruption of the tumor-suppressive ERK-p38/JNK cross-talk. Restoring GADD45β expression in cancer cells reactivates p38/JNK signaling and suppresses tumorigenesis. Our findings delineate a molecular mechanism by which normal cells sense and respond to oncogenic stress to prevent abnormal growth, and highlight the significance of its dysregulation in cancer.

Effect of neutrophils on tumor immunity and immunotherapy resistance with underlying mechanisms

Neutrophils are key mediators of the immune response and play essential roles in the development of tumors and immune evasion. Emerging studies indicate that neutrophils also play a critical role in the immunotherapy resistance in cancer. In this review, firstly, we summarize the novel classification and phenotypes of neutrophils and describe the regulatory relationships between neutrophils and tumor metabolism, flora microecology, neuroendocrine and tumor therapy from a new perspective. Secondly, we review the mechanisms by which neutrophils affect drug resistance in tumor immunotherapy from the aspects of the immune microenvironment, tumor antigens, and epigenetics. Finally, we propose several promising strategies for overcoming tumor immunotherapy resistance by targeting neutrophils and provide new research ideas in this area.

Platelet's plea to Immunologists: Please do not forget me

Platelets are non-nucleated mammalian cells originating from the cytoplasmic expulsion of the megakaryocytes. Megakaryocytes develop during hematopoiesis through megakaryopoiesis, whereas platelets develop from megakaryocytes through thrombopoiesis. Since their first discovery, platelets have been studied as critical cells controlling hemostasis or blood coagulation. However, coagulation and innate immune response are evolutionarily linked processes. Therefore, it has become critical to investigate the immunological functions of platelets to maintain immune homeostasis. Advances in immunology and platelet biology research have explored different critical roles of platelets, including phagocytosis, release of different immune mediators, and controlling functions of different immune cells by direct interaction and immune mediators. The current article discusses platelet's development and their critical role as innate immune cells, which express different pattern recognition receptors (PRRs), recognizing different pathogen or microbe-associated molecular patterns (PAMPs or MAMPs) and death/damage-associated molecular patterns (DAMPs) and their direct interactions with innate and adaptive immune cells to maintain immune homeostasis.

Neutrophil and Colorectal Cancer

Colorectal cancer (CRC) is often associated with metastasis and recurrence and is the leading cause of cancer-related mortality. In the progression of CRC, recent studies have highlighted the critical role of neutrophils, particularly tumor-associated neutrophils (TANs). TANs have both tumor-promoting and tumor-suppressing activities, contributing to metastasis, immunosuppression, angiogenesis, and epithelial-to-mesenchymal transition. Tumor-promoting TANs promote tumor growth by releasing proteases, reactive oxygen species, and cytokines, whereas tumor-suppressing TANs enhance immune responses by activating T cells and natural killer cells. Understanding the mechanisms underlying TAN mobilization, plasticity, and their role in the tumor microenvironment has revealed potential therapeutic targets. This review provides a comprehensive overview of TAN biology in CRC and discusses both the tumor-promoting and tumor-suppressing functions of neutrophils. Novel therapeutic approaches targeting TANs, such as chemokine receptor antagonists, aim to modulate neutrophil reprogramming and offer promising avenues for improving treatment outcomes of CRC.

Cryoablation-induced neutrophil Ca2+ elevation and NET formation exacerbate immune escape in colorectal cancer liver metastasis

BACKGROUND

Liver metastasis poses a significant barrier to effective immunotherapy in patients with colorectal cancer. Cryoablation has emerged as a vital supplementary therapeutic approach for these patients. However, its impact on the tumor microenvironment following the ablation of liver metastases remains unclear.

METHODS

We acquired multi-omics time-series data at 1 day, 5 days, and 14 days post-cryoablation, based on tumor and peripheral blood samples from clinical patients, cell co-culture models, and a liver metastases mouse model built on the MC38 cell line in C57BL/6 J mice. This dataset included single-cell transcriptomic sequencing, bulk tissue transcriptomic sequencing, 4D-Label-Free proteomics, flow cytometry data, western blot data, and histological immunofluorescence staining of pathological specimens.

RESULTS

We found that a neutrophil-related inflammatory state persisted for at least 14 days post-cryoablation. During this period, neutrophils underwent phenotypic changes, shifting from the N1 to the N2 type. Cryoablation also caused a significant increase in intracellular Ca2+ concentration in neutrophils, which triggered the formation of PAD4-dependent neutrophil extracellular traps (NETs), further promoting immune evasion. Moreover, animal studies demonstrated that depleting or inhibiting the CXCL2-CXCR2 signaling axis within neutrophils, or degrading NETs, could effectively restore the host's anti-tumor immune response.

CONCLUSIONS

These findings underscore the critical role of neutrophils and their NETs in immune escape following cryoablation. Targeting the CXCL2-CXCR2-Ca2+-PAD4 axis could enhance the therapeutic response to PD-1 antibodies, providing a potential strategy to improve treatment outcomes for colorectal cancer with liver metastases.

Neutrophils in Atopic Dermatitis

Neutrophils have a critical role in inflammation. Recent studies have identified their distinctive presence in certain types of atopic dermatitis (AD), yet their exact function remains unclear. This review aims to compile studies elucidating the role of neutrophils in AD pathophysiology. Proteins released by neutrophils, including myeloperoxidase, elastase, and lipocalin, contribute to pruritus progression in AD. Neutrophilic oxidative stress and the formation of neutrophil extracellular traps may further worsen AD. Elevated neutrophil elastase and high-mobility group box 1 protein expression in AD patients' skin exacerbates epidermal barrier defects. Neutrophil-mast cell interactions in allergic inflammation steer the immunological response toward Th2 imbalance and activate the Th17 pathway, particularly in response to allergens or infections linked to AD. Notably, drugs alleviating pruritic symptoms in AD inhibit neutrophilic inflammation. In conclusion, these findings underscore that neutrophils may be therapeutic targets for AD symptoms, emphasizing their inclusion in AD treatment strategies.

Chaga Mushroom Triterpenoids Inhibit Dihydrofolate Reductase and Act Synergistically with Conventional Therapies in Breast Cancer

Inonotus obliquus (Chaga) is a medicinal mushroom with several pharmacological properties that is used as a tea in traditional Chinese medicine. In this study, Chaga water extract was digested in vitro to mimic the natural processing and absorption of its biocomponents when it is consumed as functional beverage, and its anticancer activities were evaluated in breast cancer (BC) cell lines, representing HER2-positive and triple-negative subtypes. After chemical characterization by liquid chromatography/mass spectrometry (HR-QTOF) analysis, the effect of Chaga biocomponents on cell viability and cell cycle progression was assessed by MTT assay, FACS analysis, and Western blot. Dihydrofolate reductase (DHFR) activity was measured by an enzymatic assay. Four highly bioactive triterpenoids (inotodiol, trametenolic acid, 3-hydroxy-lanosta-8,24-dien-21-al, and betulin) were identified as the main components, able to decrease BC cell viability and block the cell cycle in G0/G1 by inducing the downregulation of cyclin D1, CDK4, cyclin E, and phosphorylated retinoblastoma protein. DHFR was identified as their crucial target. Moreover, bioactive Chaga components exerted a synergistic action with cisplatin and with trastuzumab in SK-BR-3 cells by inhibiting both HER2 and HER1 activation and displayed an immunomodulatory effect. Thus, Inonotus obliquus represents a source of triterpenoids that are effective against aggressive BC subtypes and display properties of targeted drugs.

Identification of CAPG as a potential prognostic biomarker associated with immune cell infiltration and ferroptosis in uterine corpus endometrial carcinoma

Introduction

Capping actin protein, gelsolin-like (CAPG) is a potential therapeutic target in various cancers. However, the potential immunotherapeutic effects and prognostic value of CAPG in uterine corpus endometrial carcinoma (UCEC) remain unclear.

Methods

The characterization, methylation effects, prognostic value, targeted miRNAs of CAPG, and the correlation of CAPG with immune cell infiltration and ferroptosis in UCEC were investigated using multiple public databases and online tools. Furtherly, we explored the potential physiological function of CAPG using EdU and Transwell migration assays, identified the cell localization and expression of CAPG and GPX4 by immunofluorescence, and detected the intracellular Fe2+ levels using a FerroOrange fluorescent probe in Ishikawa cells. Additionally, the OncoPredict package was used to analyze the potential chemotherapeutic drugs for UCEC.

Results

CAPG showed generally high expression in tumor group. The overall survival rate of the high-risk group was significantly lower than that of the low-risk group. Enrichment analysis indicated that CAPG is involved in immune-related pathways and is closely associated with the tumor microenvironment. CAPG expression levels were affected by abnormal DNA methylation and/or targeted miRNAs, infiltration levels and marker genes of various immune cells, thereby impacting immune response, ferroptosis, and patient prognosis. Ferroptosis analysis indicated that ALOX5 and VLDLR were the top CAPG-related ferroptosis markers; glutathione metabolism levels in tumor group were generally high, and decitabine was a ferroptosis inducer. CAPG-siRNA suppressed the cell proliferation and invasion, and markedly elevated the expression levels of immune-related genes IL8, TNF, TLR4 and the intracellular Fe2+ levels. CAPG co-located with GPX4 in nucleus and co-regulated ferroptosis and metabolism in Ishikawa cells. Moreover, four chemotherapy drugs showed better sensitivity to UCEC patients in the low-risk cohort.

Conclusions

CAPG may serve as a potential biomarker of UCEC owing to its role in modulating the immune response and ferroptosis, providing novel perspectives for combined immunotherapy of UCEC.

Comparison of differences in immune cells and immune microenvironment among different kinds of oncolytic virus treatments

Oncolytic viruses are either naturally occurring or genetically engineered viruses that can activate immune cells and selectively replicate in and destroy cancer cells without damaging healthy tissues. Oncolytic virus therapy (OVT) represents an emerging treatment approach for cancer. In this review, we outline the properties of oncolytic viruses and then offer an overview of the immune cells and tumor microenvironment (TME) across various OVTs. A thorough understanding of the immunological mechanisms involved in OVTs could lead to the identification of novel and more effective therapeutic targets for cancer treatment.

SKAP1 Expression in Cancer Cells Enhances Colon Tumor Growth and Impairs Cytotoxic Immunity by Promoting Neutrophil Extracellular Trap Formation via the NFATc1/CXCL8 Axis

The mechanisms underlying the development and progression of colon cancer are not fully understood. Herein, Src kinase associated phosphoprotein 1 (SKAP1), an immune cell adaptor, is identified as a novel colon cancer-related gene. SKAP1 expression is significantly increased in colon cancer cells. High SKAP1 levels are independently predictive of poor survival in patients with colon cancer. Notably, SKAP1 expression in colon cancer cells exerted a significant tumor-promoting effect in vivo rather than in vitro. Screening of tumor-infiltrating immune cells revealed the involvement of neutrophils in SKAP1-induced colon tumor promotion. Enhanced formation of neutrophil extracellular traps (NETs) is found to be a key downstream event that contributed to the pro-tumor role of SKAP1. In colon cancer cells, SKAP1 increased the expression of C-X-C motif chemokine ligand 8 (CXCL8) via nuclear factor of activated T cells c1 (NFATc1). The blockade of CXCL8 or NFATc1 largely attenuated neutrophil infiltration, NET formation, and tumor promotion induced by SKAP1. Furthermore, inhibiting SKAP1-induced NET significantly enhanced the antitumor efficiency of adoptive natural killer cell therapy in colon tumor models. In conclusion, SKAP1 significantly promotes colon cancer growth via the cancer cell/neutrophil NFATc1/CXCL8/NET axis, suggesting that SKAP1 is a potential target for colon cancer therapy.

Role of neutrophils in the pathogenesis of Post Kala-azar Dermal Leishmaniasis (PKDL)

BACKGROUND

Post Kala-azar Dermal Leishmaniasis (PKDL) is a dermal sequel of visceral leishmaniasis (VL), poses a significant threat to the success of ongoing kala-azar elimination program, due to its potential role in sustaining transmission cycles and complicating disease management strategies. In VL, neutrophils have been identified as the 'first line of defence', having multiple roles in disease pathogenesis, but their role in PKDL, if any, still remains elusive; presenting a critical gap in knowledge, and was the aim of this study.

METHODOLOGY/PRINCIPAL FINDINGS

In a cohort of PKDL patients, CD66b+ neutrophils were quantified in skin biopsies, followed by immunostaining of FFPE sections to identify activated neutrophils (CD66b+/CD64+) and degranulated (CD66b+/MPO+), along with expression of neutrophil elastase (NE), matrix metalloprotease 9 (MMP9) and collagen I. Plasma levels of neutrophil chemo-attractants CXCL8/1/2/5, CCL2 and 20 and cytokines, (IL-6, IFN-γ, IL-4, IL-10, TNF-α, IL-17 and IL-22, 23) were evaluated by a multiplex assay, while lesional expression of IL-8, IL-10 and IL-17 was evaluated by immunohistochemistry. As compared to healthy individuals (control skin samples), PKDL cases at the lesional sites had an increased number of activated CD66b+ neutrophils (positive for CD64+, MPO+ and NE+). The plasma levels of neutrophil chemo-attractants, pro-inflammatory and regulatory cytokines were raised as was circulating and lesional IL-8, along with an enhanced lesional expression of IL-10 and IL-17A. An increase in circulatory and lesional MMP9 was accompanied by decreased collagen I, suggesting disintegration of matrix integrity.

CONCLUSIONS/SIGNIFICANCE

Taken together, in PKDL, activated neutrophils possibly contribute towards modulating the lesional landscape. Understanding this involvement of neutrophils in patients with PKDL, particularly in the absence of an animal model, could offer better understanding of the disease pathogenesis and provide insights into novel therapeutic strategies for the ongoing elimination program.

Unraveling the complex role of neutrophils in lymphoma: From pathogenesis to therapeutic approaches (Review)

Lymphoma, a malignancy of the lymphatic system, which is critical for maintaining the body's immune defenses, has become a focal point in recent research due to its intricate interplay with neutrophils-white blood cells essential for combating infections and inflammation. Unlike prior perceptions associating neutrophils only with tumor support, contemporary studies underscore their intricate and multifaceted involvement in the immune response to lymphoma. Recognizing the nuanced participation of neutrophils in lymphoma is crucial for developing innovative treatments to improve patient outcomes.

hnRNPAB Promotes Pancreatic Ductal Adenocarcinoma Extravasation and Liver Metastasis by Stabilizing MYC mRNA

Heterogeneous nuclear ribonucleoprotein AB (hnRNPAB) is considered a cancer-promoting heterogeneous nuclear ribonucleoprotein in many cancers, but its function in pancreatic ductal adenocarcinoma (PDAC) is poorly understood. hnRNPAB was highly expressed in PDAC tissues compared with normal pancreatic tissues, and high expression of hnRNPAB was associated with poor overall survival and recurrence-free survival in patients with PDAC. hnRNPAB promotes migration and invasion of PDAC cells in vitro. In xenograft tumor mouse models, hnRNPAB deprivation significantly attenuated liver metastasis. hnRNPAB mRNA and protein levels are positively associated with MYC in PDAC cells. Mechanistically, hnRNPAB bound to MYC mRNA and prolonged its half-life. hnRNPAB induced PDAC cells to secrete CXCL8 via MYC, which promoted neutrophil recruitment and facilitated tumor cells entrancing into the hepatic parenchyma. These findings point to a novel regulatory mechanism via which hnRNPAB promotes PDAC metastasis. Implications: hnRNPAB participates in the posttranscriptional regulation of the oncogene MYC by binding and stabilizing MYC mRNA, thereby promoting liver metastasis in PDAC.

A subset of neutrophils activates anti-tumor immunity and inhibits non-small-cell lung cancer progression

Neutrophils in the tumor microenvironment (TME) are heterogeneous populations associated with cancer prognosis and immunotherapy. However, the plasticity and function of heterogeneous neutrophils in the TME of non-small-cell lung cancer (NSCLC) remain unclear. Here, we show that neutrophils produce high levels of interleukin (IL)-8, which induce the differentiation of CD74highSiglecFlow neutrophils and suppress the generation of CD74lowSiglecFhigh neutrophils in the TME of IL-8-humanized NSCLC mice. The CD74highSiglecFlow neutrophils boost anti-tumor T cell responses via antigen cross-presentation. Deleting CD74 in IL-8-humanized neutrophils impairs T cell activation and exacerbates NSCLC progression, whereas a CD74 agonist enhances T cell activation and the efficacy of anti-programmed cell death 1 (PD-1) or osimertinib therapies. Additionally, the CD74highCD63low neutrophils in the TME and peripheral blood of advanced NSCLC patients phenocopy the CD74highSiglecFlow neutrophils in the TME of NSCLC mice and correlate well with the responsiveness to anti-PD-1 plus chemotherapies. These findings demonstrate an IL-8-CD74high neutrophil axis that promotes anti-tumor immunity in NSCLC.

New avenues for cancer immunotherapy: Cell-mediated drug delivery systems

Cancer research has become increasingly complex over the past few decades as knowledge of the heterogeneity of cancer cells, their proliferative ability, and their tumor microenvironments has become available. Although conventional therapies remain the most compelling option for cancer treatment to date, immunotherapy is a promising way to harness natural immune defenses to target and kill cancer cells. Cell-mediated drug delivery systems (CDDSs) have been an active line of research for enhancing the therapeutic efficacy and specificity of cancer immunotherapy. These systems can be tailored to different types of immune cells, allowing immune evasion and accumulation in the tumor microenvironment. By enabling the targeted delivery of therapeutic agents such as immune stimulants, cytokines, antibodies, and antigens, CDDSs have improved the survival of some patients with cancer. This review summarizes the research status of CDDSs, with a focus on their underlying mechanisms of action, biology, and clinical applications. We also discuss opportunities and challenges for implementation of CDDSs into mainstream cancer immunotherapy.

PoCXCL8, a teleost chemokine, exerts direct bactericidal, chemotactic/phagocytic, and NETs releasing properties, promoting host anti-bacterial immunity

As an important CXC chemokine, CXCL8 plays pleiotropic roles in immunological response. In teleost, CXCL8 is involved in cell migration and bacterial invasion. However, the immune antibacterial function of CXCL8 in Japanese flounder (Paralichthys olivaceus) (PoCXCL8) is largely scarce. In this research, we investigated the antibacterial property and leukocyte activation of PoCXCL8. PoCXCL8 consists of 100 amino acid residues, with a conserved chemokine CXC domain. PoCXCL8 was expressed in various tissues, with the highest level in liver and the lowest level in muscle, and sharply induced by V. harveyi or E. tarda in liver, spleen, and head kidney. In vitro, the recombinant PoCXCL8 (rPoCXCL8) could bind to Bacillus subtilis, Edwardsiella tarda, Escherichia coli, Pseudomonas fluorescens, Vibrio anguillarum, Vibrio harveyi, Staphylococcus aureus, and Micrococcus luteus, affect the growth of E. coli, E. tarda, M. luteus, and P. fluorescens, and have a direct bactericidal effect on E. coli and E. tarda. Moreover, rPoCXCL8 was able to bind the outer membranal protein rPilA of E. tarda. In addition, rPoCXCL8 could bind to PBLs, activating the PBLs activity including chemotaxis, proliferation, phagocytosis, reactive oxygen species, acid phosphatase activity. At same time, rPoCXCL8 could induce neutrophil to generate neutrophil extracellular traps (NETs) and promote the expression of inflammatory genes including IL-1β, IL6, MMP13, TNF-α, and NF-κB. In flounder, the presence of rPoCXCL8 could enhance the in vivo resistance to E. tarda in liver, spleen, and head kidney. Moreover, the PoCXCL8-deficient could attenuate the fish defense against E. tarda infection in in spleen and head kidney. In conclusion, these results provided new insights into the antibacterial properties of CXCL8 in P. olivaceus.

Pro-inflammatory cytokines increase temporarily after adjuvant treatment for breast cancer in postmenopausal women: a longitudinal study

BACKGROUND

Breast cancer patients have an increased risk of cardiometabolic disease and for many patients, adjuvant therapy causes an altered lipid profile, insulin resistance and inflammation. Previous follow-up studies are inconclusive regarding the duration of therapy-induced inflammation. We examined the acute and persistent changes of adjuvant chemotherapy on inflammatory and metabolic health markers in breast cancer patients.

METHODS

Plasma levels of IL-6, IL-8, IL-10, IFN-γ, TNF-α, high-sensitivity C-reactive protein (hsCRP) and metabolic health parameters were analyzed before, shortly after and every six months up to two years after adjuvant chemotherapy treatment in 51 postmenopausal early breast cancer (EBC) patients, as well as in 41 healthy age- and BMI-matched controls. A target-specific multiplex assay was applied for cytokine measurements.

RESULTS

Before initiation of adjuvant therapy, plasma IL-8 levels were higher in EBC patients (31%, p = 0.0001). Also, a larger proportion of the patients had a hsCRP level above 2 mg/L (41%) compared to the controls (17%, Χ2 = 5.15, p = 0.023). Plasma levels of all five cytokines, but not hsCRP, were significantly increased after compared to before adjuvant chemotherapy (15-48% increase; all p ≤ 0.05). Already six months after ending chemotherapy treatment, all plasma cytokine levels were significantly reduced and close to pre-chemotherapy levels. Adjuvant chemotherapy caused a worsened lipid profile (increased triglycerides, lower HDL levels), insulin resistance and increased plasma insulin levels that remained high during the first year after chemotherapy.

CONCLUSION

Postmenopausal women with EBC have temporarily increased plasma levels of pro-inflammatory cytokines after adjuvant chemotherapy. Although transient, the therapy-induced increase in plasma cytokine levels, together with dyslipidemia and insulin resistance, may contribute to cardiometabolic risk in breast cancer patients treated with adjuvant chemotherapy.

TRIAL REGISTRATION

The clinical trial (registration number NCT03784651) was registered on www.

CLINICALTRIALS

gov on 24 December 2018.

Neutrophil chemotaxis score and chemotaxis-related genes have the potential for clinical application to prognosticate the survival of patients with tumours

As frontline cells, the precise recruitment of neutrophils is crucial for resolving inflammation and maintaining the homeostasis of the organism. Increasing evidence suggests the pivotal role of neutrophil chemotaxis in cancer progression and metastasis. Here, we collected clinical data and peripheral blood samples from patients with tumours to examine the alterations in the neutrophil quantity and chemotactic function using the Cell Chemotaxis Analysis Platform (CCAP). Transcriptome sequencing data of pan-cancer were obtained from The Cancer Genome Atlas (TCGA). Using the least absolute shrinkage and selection operator (LASSO) Cox regression model, we selected a total of 29 genes from 155 neutrophil- and chemotaxis-related genes to construct the ChemoScore model. Meanwhile, nomogram-based comprehensive model was established for clinical application. Furthermore, immunofluorescence (IF) staining was employed to assess the relationship between the neutrophils infiltrating and the survival outcomes of tumours. In this observational study, the chemotactic function of neutrophils was notably diminished in patients. The establishment and validation of ChemoScore suggested neutrophil chemotaxis to be a risk factor in most tumours, whereby higher scores were associated with poorer survival outcomes and were correlated with various immune cells and malignant biological processes. Moreover, IF staining of tumour tissue substantiated the adverse correlation between neutrophil infiltration and the survival of patients with lung adenocarcinoma (P = 0.0002) and colon adenocarcinoma (P = 0.0472). Taken together, patients with tumours demonstrated a decrease in chemotactic function. ChemoScore potentially prognosticates the survival of patients with tumours. Neutrophil chemotaxis provides novel directions and theoretical foundations for anti-tumour treatment.

Senescent neutrophils: a hidden role in cancer progression

Neutrophils have recently received increased attention in cancer because they contribute to all stages of cancer. Neutrophils are so far considered to have a short half-life. However, a growing body of literature has shown that tumor-associated neutrophils (TANs) acquire a prolonged lifespan. This review discusses recent work surrounding the mechanisms by which neutrophils can persist in the tumor microenvironment (TME). It also highlights different scenarios for therapeutic targeting of protumorigenic neutrophils, supporting the idea that, in tumors, inhibition of neutrophil recruitment is not sufficient because these cells can persist and remain hidden from current interventions. Hence, the elimination of long-lived neutrophils should be pursued to increase the efficacy of standard therapy.

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.

Sex-dependent APOE4 neutrophil-microglia interactions drive cognitive impairment in Alzheimer's disease

APOE4 is the strongest genetic risk factor for Alzheimer's disease (AD), with increased odds ratios in female carriers. Targeting amyloid plaques shows modest improvement in male non-APOE4 carriers. Leveraging single-cell transcriptomics across APOE variants in both sexes, multiplex flow cytometry and validation in two independent cohorts of APOE4 female carriers with AD, we identify a new subset of neutrophils interacting with microglia associated with cognitive impairment. This phenotype is defined by increased interleukin (IL)-17 and IL-1 coexpressed gene modules in blood neutrophils and in microglia of cognitively impaired female APOE ε4 carriers, showing increased infiltration to the AD brain. APOE4 female IL-17+ neutrophils upregulated the immunosuppressive cytokines IL-10 and TGFβ and immune checkpoints, including LAG3 and PD-1, associated with accelerated immune aging. Deletion of APOE4 in neutrophils reduced this immunosuppressive phenotype and restored the microglial response to neurodegeneration, limiting plaque pathology in AD mice. Mechanistically, IL-17F upregulated in APOE4 neutrophils interacts with microglial IL-17RA to suppress the induction of the neurodegenerative phenotype, and blocking this axis supported cognitive improvement in AD mice. These findings provide a translational basis to target IL-17F in APOE ε4 female carriers with cognitive impairment.

PoIL8-L, a teleost interleukin-8 like, enhances leukocyte cellular vitality and host defense against bacterial infections in Japanese flounder (Paralichthys olivaceus)

Interleukin-8 (IL-8), a CXC chemokine, exerts pivotal effect on cell migration, inflammatory response, and immune regulation. In this study, we examined the immunological characteristics of an IL-8 like homologue (PoIL8-L) in Japanese flounder (Paralichthys olivaceus). PoIL8-L contains a conserved chemokine CXC domain and 105 amino acid residues. PoIL8-L expression in tissues was constitutive, and significantly regulated by V. havieri or E. tarda infection. In vitro, rPoIL8-L could bind to eight tested bacteria, exhibited bacteriostatic and bactericidal effects against certain bacteria, and could bind to the targeted bacterial Ⅳ pilin protein rPilA of E. tarda. Furthermore, rPoIL8-L could attach to peripheral blood leukocytes, and enhance their immune genes expression, respiratory burst, chemotaxis, proliferation, acid phosphatase activity, and phagocytic activity. Additionally, rPoIL8-L induce neutrophils to extrude neutrophil extracellular traps. In vivo, rPoIL8-L could promote host resistance to E. tarda infection. In summary, these findings provide fresh perspectives on the immunological antibacterial properties of IL-8 in teleost.

Global research trends and focus on the link between neutrophil extracellular traps and tumor: a bibliometric and visualization analysis from 2006 to 2024

Background

Neutrophil extracellular traps (NETs) have long been consistently considered an innate immune defense against foreign pathogens, but this oversimplified view has decelerated the progression of perceiving NET biology in chronic diseases. It is now increasingly accepted that NETs are not exclusive to anti-infection responses, but are also central players with a double-edged sword role in cancer progression. NETs have gradually emerged as tumor diagnostic, predictive, and prognostic biomarkers, and strenuous endeavors have been devoted to tapping their potential as new therapeutic targets. Correspondingly, the boom in studies on NETs and tumors in recent years has achieved a series of scientific outputs, which opens up a new perspective for perceiving the sophisticated landscapes of the tumor immune microenvironment. However, there is still much room to translate NET-targeted immunotherapies into clinical practice. Therefore, it is necessary to explore the knowledge structure and latent hotspots of the links between NETs and tumors using bibliometric analysis.

Methods

NETs and tumor publications from 2006 to 2024 were extracted from the Web of Science Core Collection. Bibliometric analysis and visualization were conducted using Microsoft Excel, VOSviewer, CiteSpace, and R-bibliometrix.

Results

The analysis included 1,339 publications authored by 7,747 scholars affiliated with 1,926 institutions across 70 countries/regions with relevant articles published in 538 journals. Despite China's maximum number of publications, the United States has continued to dominate the field as a global cooperation center with overwhelming citation counts. Frontiers in Immunology published the most number of publications, whereas Blood was the most cited journal. Wagner, Denisa D. and Kaplan, Mariana J. are concurrently in both the top 10 most prolific authors and cited author lists. Tumor microenvironment and immunotherapy will likely be the focus of future research.

Conclusions

A comprehensive bibliometric analysis was first conducted to map the current landscape and knowledge structure of the link between NETs and tumors in the hope of providing guidance and fresh perspectives for further research in this field. NETs are promising antitumor targets, and perhaps the eventual destination in the realm is to translate NET-targeted immunotherapies into clinical practice.

Neutrophil extracellular traps in homeostasis and disease

Neutrophil extracellular traps (NETs), crucial in immune defense mechanisms, are renowned for their propensity to expel decondensed chromatin embedded with inflammatory proteins. Our comprehension of NETs in pathogen clearance, immune regulation and disease pathogenesis, has grown significantly in recent years. NETs are not only pivotal in the context of infections but also exhibit significant involvement in sterile inflammation. Evidence suggests that excessive accumulation of NETs can result in vessel occlusion, tissue damage, and prolonged inflammatory responses, thereby contributing to the progression and exacerbation of various pathological states. Nevertheless, NETs exhibit dual functionalities in certain pathological contexts. While NETs may act as autoantigens, aggregated NET complexes can function as inflammatory mediators by degrading proinflammatory cytokines and chemokines. The delineation of molecules and signaling pathways governing NET formation aids in refining our appreciation of NETs' role in immune homeostasis, inflammation, autoimmune diseases, metabolic dysregulation, and cancer. In this comprehensive review, we delve into the multifaceted roles of NETs in both homeostasis and disease, whilst discussing their potential as therapeutic targets. Our aim is to enhance the understanding of the intricate functions of NETs across the spectrum from physiology to pathology.

Low-Dose Ionizing γ-Radiation Elicits the Extrusion of Neutrophil Extracellular Traps

PURPOSE

Patients with cancer frequently undergo radiotherapy in their clinical management with unintended irradiation of blood vessels and copiously irrigated organs in which polymorphonuclear leukocytes circulate. Following the observation that such low doses of ionizing radiation are able to induce neutrophils to extrude neutrophil extracellular traps (NET), we have investigated the mechanisms, consequences, and occurrence of such phenomena in patients undergoing radiotherapy.

EXPERIMENTAL DESIGN

NETosis was analyzed in cultures of neutrophils isolated from healthy donors, patients with cancer, and cancer-bearing mice under confocal microscopy. Cocultures of radiation-induced NETs, immune effector lymphocytes, and tumor cells were used to study the effects of irradiation-induced NETs on immune cytotoxicity. Radiation-induced NETs were intravenously injected to mice for assessing their effects on metastasis. Circulating NETs in irradiated patients with cancer were measured using ELISA methods for detecting MPO-DNA complexes and citrullinated histone 3.

RESULTS

Irradiation of neutrophils with very low γ-radiation doses (0.5-1 Gy) elicits NET formation in a manner dependent on oxidative stress, NADPH oxidase activity, and autocrine IL8. Radiation-induced NETs interfere with NK cell and T-cell cytotoxicity. As a consequence, preinjection of irradiation-induced NETs increases the number of successful metastases in mouse tumor models. Increases in circulating NETs were readily detected in two prospective series of patients following the first fraction of their radiotherapy courses.

CONCLUSIONS

NETosis is induced by low-dose ionizing irradiation in a neutrophil-intrinsic fashion, and radiation-induced NETs are able to interfere with immune-mediated cytotoxicity. Radiation-induced NETs foster metastasis in mouse models and can be detected in the circulation of patients undergoing conventional radiotherapy treatments. See related commentary by Mowery and Luke, p. 3965.

NETosis Impact on Tumor Biology, Radiation, and Systemic Therapy Resistance

Neutrophil extracellular trap (NET)osis via lytic neutrophil death or neutrophil activation is associated with standard cancer therapies, notably including radiotherapy; is immunosuppressive; and may enhance metastasis and treatment resistance. This emerging area of research should be prioritized in drug development and standard of care treatment paradigms including radiation therapy, chemotherapy, and immunotherapy. See related article by Teijeira et al., p. 4131.

Prognostic Significance of Plasma Neutrophil Extracellular Trap Levels in Patients with Non-Small Cell Lung Cancer Treated with Immune Checkpoint Inhibitors

Neutrophil extracellular traps (NETs) released from neutrophils are related to cancer progression. However, the relationship between the therapeutic effects of immune checkpoint inhibitors (ICIs) such as anti-PD-1 and anti-PD-L1 antibodies and plasma NET concentration in patients with non-small cell lung cancer (NSCLC) is poorly understood. In this study, concentrations of citrullinated histone H3 (CitH3), a surrogate marker of NETs, in plasma before/after treatment were examined in patients with advanced or recurrent NSCLC undergoing ICI treatment (n = 185). The clinical significances of NET levels before/after treatment and posttreatment changes were statistically evaluated. As a result, multivariate Cox analysis showed that high NET levels before treatment were statistically significant predictors of unfavorable overall survival (OS; p < 0.001, HR 1.702, 95% CI 1.356-2.137) and progression-free survival (PFS; p < 0.001, HR 1.566, 95% CI 1.323-1.855). The Kaplan-Meier curves showed significant separation between the high- and low-NET groups in OS (p = 0.002) and PFS (p < 0.001). Additionally, high NET levels after treatment were also significantly associated with worse OS (p < 0.001) and PFS (p < 0.001) by multivariate Cox analysis. Notably, the pretreatment NET levels were significantly correlated with the plasma levels of NET-related inflammatory cytokines, such as IL-6 and IL-8, and with NET-related gene expression and immune-suppressive profile in peripheral blood mononuclear cells. Our findings suggest that NETs released from activated neutrophils might reduce the clinical efficacy of ICIs in patients with NSCLC.

Immunocompetent PDMS-Free Organ-on-Chip Model of Cervical Cancer Integrating Patient-Specific Cervical Fibroblasts and Neutrophils

Despite preventive measures and available treatments, cervical cancer still ranks as the fourth most prevalent cancer among women worldwide and remains the leading cause of cancer death in women in many developing countries. To gain further insights into pathogenesis and to develop novel (immuno)therapies, more sophisticated human models recreating patient heterogeneities and including aspects of the tumor microenvironment are urgently required. A novel polydimethylsiloxane-free microfluidic platform, designed specifically for the generation and ccultivation of cervical cancerous tissue, is introduced. The microscale open-top tissue chambers of the cervical cancer-on-chip (CCoC) enable facile generation and long-term cultivation of SiHa spheroids in co-culture with donor-derived cervical fibroblasts. The resulting 3D tissue emulates physiological architecture and allows dissection of distinct effects of the stromal tissue on cancer viability and growth. Treatment with cisplatin at clinically-relevant routes of administration and dosing highlights the platform's applicability for drug testing. Moreover, the model is amenable for integration and recruitment of donor-derived neutrophils from the microvasculature-like channel into the tissue, all while retaining their ability to produce neutrophil extracellular traps. In the future, the immunocompetent CCoC featuring donor-specific primary cells and tumor spheroids has the potential to contribute to the development of new (immuno)therapeutic options.

Machine learning framework develops neutrophil extracellular traps model for clinical outcome and immunotherapy response in lung adenocarcinoma

Neutrophil extracellular traps (NETs) are novel inflammatory cell death in neutrophils. Emerging studies demonstrated NETs contributed to cancer progression and metastases in multiple ways. This study intends to provide a prognostic NETs signature and therapeutic target for lung adenocarcinoma (LUAD) patients. Consensus cluster analysis performed by 38 reported NET-related genes in TCGA-LUAD cohorts. Then, WGCNA network was conducted to investigate characteristics genes in clusters. Seven machine learning algorithms were assessed for training of the model, the optimal model was picked by C-index and 1-, 3-, 5-year ROC value. Then, we constructed a NETs signature to predict the overall survival of LUAD patients. Moreover, multi-omics validation was performed based on NETs signature. Finally, we constructed stable knockdown critical gene LUAD cell lines to verify biological functions of Phospholipid Scramblase 1 (PLSCR1) in vitro and in vivo. Two NETs-related clusters were identified in LUAD patients. Among them, C2 cluster was provided as "hot" tumor phenotype and exhibited a better prognosis. Then, WGCNA network identified 643 characteristic genes in C2 cluster. Then, Coxboost algorithm proved its optimal performance and provided a prognostic NETs signature. Multi-omics revealed that NETs signature was involved in an immunosuppressive microenvironment and predicted immunotherapy efficacy. In vitro and in vivo experiments demonstrated that knockdown of PLSCR1 inhibited tumor growth and EMT ability. Besides, cocultural assay indicated that the knockdown of PLSCR1 impaired the ability of neutrophils to generate NETs. Finally, tissue microarray (TMA) for LUAD patients verified the prognostic value of PLSCR1 expression. In this study, we focus on emerging hot topic NETs in LUAD. We provide a prognostic NETs signature and identify PLSCR1 with multiple roles in LUAD. This work can contribute to risk stratification and screen novel therapeutic targets for LUAD patients.

Immune dysregulation is an important factor in the underlying complications in Influenza infection. ApoH, IL-8 and IL-15 as markers of prognosis

Introduction

Influenza virus infection can cause a range of clinical symptoms, including respiratory failure (RF) and even death. The mechanisms responsible for the most severe forms of the disease are not yet well understood. The objective is to assess the initial immune response upon admission and its potential impact on infection progression.

Methods

We conducted a prospective observational study of patients with influenza virus infection who required admission to a tertiary hospital in the 2017/18 and 2018/19 flu seasons. Immune markers, surrogate markers of neutrophil activation, and blood levels of DNase I and Apolipoprotein-H (ApoH) were determined in the first serum sample available during hospital care. Patients were followed until hospital discharge or death. Initially, 792 patients were included. From this group, 107 patients with poor evolution were selected, and a random control group was matched by day of admission.

Results

Patients with poor outcomes had significantly reduced ApoH levels, a soluble protein that regulate both complement and coagulation pathways. In multivariate analysis, low plasma levels of ApoH (OR:5.43; 2.21-13.4), high levels of C- reactive protein (OR:2.73: 1.28-5.4), hyperferritinemia (OR:2.83; 1.28-5.4) and smoking (OR:3.41; 1.04-11.16), were significantly associated with a worse prognosis. RF was independently associated with low levels of ApoH (OR: 5.12; 2.02-1.94), while high levels of IL15 behaved as a protective factor (OR:0.30; 0.12-0.71).

Discussion

Therefore, in hospitalized influenza patients, a dysregulated early immune response is associated with a worse outcome. Adequate plasma levels of ApoH are protective against severe influenza and RF and High levels of IL15 protect against RF.

In-depth analysis of the interplay between oncogenic mutations and NK cell-mediated cancer surveillance in solid tumors

Natural killer (NK) cells play a crucial role in antitumoral and antiviral responses. Yet, cancer cells can alter themselves or the microenvironment through the secretion of cytokines or other factors, hindering NK cell activation and promoting a less cytotoxic phenotype. These resistance mechanisms, often referred to as the "hallmarks of cancer" are significantly influenced by the activation of oncogenes, impacting most, if not all, of the described hallmarks. Along with oncogenes, other types of genes, the tumor suppressor genes are frequently mutated or modified during cancer. Traditionally, these genes have been associated with uncontrollable tumor growth and apoptosis resistance. Recent evidence suggests oncogenic mutations extend beyond modulating cell death/proliferation programs, influencing cancer immunosurveillance. While T cells have been more studied, the results obtained highlight NK cells as emerging key protagonists for enhancing tumor cell elimination by modulating oncogenic activity. A few recent studies highlight the crucial role of oncogenic mutations in NK cell-mediated cancer recognition, impacting angiogenesis, stress ligands, and signaling balance within the tumor microenvironment. This review will critically examine recent discoveries correlating oncogenic mutations to NK cell-mediated cancer immunosurveillance, a relatively underexplored area, particularly in the era dominated by immune checkpoint inhibitors and CAR-T cells. Building on these insights, we will explore opportunities to improve NK cell-based immunotherapies, which are increasingly recognized as promising alternatives for treating low-antigenic tumors, offering significant advantages in terms of safety and manufacturing suitability.

Machine learning based on metabolomics unveils neutrophil extracellular trap-related metabolic signatures in non-small cell lung cancer patients undergoing chemoimmunotherapy

BACKGROUND

Non-small cell lung cancer (NSCLC) is the primary form of lung cancer, and the combination of chemotherapy with immunotherapy offers promising treatment options for patients suffering from this disease. However, the emergence of drug resistance significantly limits the effectiveness of these therapeutic strategies. Consequently, it is imperative to devise methods for accurately detecting and evaluating the efficacy of these treatments.

AIM

To identify the metabolic signatures associated with neutrophil extracellular traps (NETs) and chemoimmunotherapy efficacy in NSCLC patients.

METHODS

In total, 159 NSCLC patients undergoing first-line chemoimmunotherapy were enrolled. We first investigated the characteristics influencing clinical efficacy. Circulating levels of NETs and cytokines were measured by commercial kits. Liquid chromatography tandem mass spectrometry quantified plasma metabolites, and differential metabolites were identified. Least absolute shrinkage and selection operator, support vector machine-recursive feature elimination, and random forest algorithms were employed. By using plasma metabolic profiles and machine learning algorithms, predictive metabolic signatures were established.

RESULTS

First, the levels of circulating interleukin-8, neutrophil-to-lymphocyte ratio, and NETs were closely related to poor efficacy of first-line chemoimmunotherapy. Patients were classed into a low NET group or a high NET group. A total of 54 differential plasma metabolites were identified. These metabolites were primarily involved in arachidonic acid and purine metabolism. Three key metabolites were identified as crucial variables, including 8,9-epoxyeicosatrienoic acid, L-malate, and bis(monoacylglycerol)phosphate (18:1/16:0). Using metabolomic sequencing data and machine learning methods, key metabolic signatures were screened to predict NET level as well as chemoimmunotherapy efficacy.

CONCLUSION

The identified metabolic signatures may effectively distinguish NET levels and predict clinical benefit from chemoimmunotherapy in NSCLC patients.

A microphysiological system reveals neutrophil contact-dependent attenuation of pancreatic tumor progression by CXCR2 inhibition-based immunotherapy

Cancer cells recruit neutrophils from the bloodstream into the tumor tissue, where these immune cells promote the progression of numerous solid tumors. Studies in mice suggest that blocking neutrophil recruitment to tumors by inhibition of neutrophil chemokine receptor CXCR2 could be a potential immunotherapy for pancreatic cancer. Yet, the mechanisms by which neutrophils promote tumor progression in humans, as well as how CXCR2 inhibition could potentially serve as a cancer therapy, remain elusive. In this study, we developed a human cell-based microphysiological system to quantify neutrophil-tumor spheroid interactions in both "separated" and "contact" scenarios. We found that neutrophils promote the invasion of tumor spheroids through the secretion of soluble factors and direct contact with cancer cells. However, they promote the proliferation of tumor spheroids solely through direct contact. Interestingly, treatment with AZD-5069, a CXCR2 inhibitor, attenuates invasion and proliferation of tumor spheroids by blocking direct contact with neutrophils. Our findings also show that CXCR2 inhibition reduces neutrophil migration toward tumor spheroids. These results shed new light on the tumor-promoting mechanisms of human neutrophils and the tumor-suppressive mechanisms of CXCR2 inhibition in pancreatic cancer and may aid in the design and optimization of novel immunotherapeutic strategies based on neutrophils.

Spatial Architecture of Myeloid and T Cells Orchestrates Immune Evasion and Clinical Outcome in Lung Cancer

Understanding the role of the tumor microenvironment (TME) in lung cancer is critical to improving patient outcomes. We identified four histology-independent archetype TMEs in treatment-naïve early-stage lung cancer using imaging mass cytometry in the TRACERx study (n = 81 patients/198 samples/2.3 million cells). In immune-hot adenocarcinomas, spatial niches of T cells and macrophages increased with clonal neoantigen burden, whereas such an increase was observed for niches of plasma and B cells in immune-excluded squamous cell carcinomas (LUSC). Immune-low TMEs were associated with fibroblast barriers to immune infiltration. The fourth archetype, characterized by sparse lymphocytes and high tumor-associated neutrophil (TAN) infiltration, had tumor cells spatially separated from vasculature and exhibited low spatial intratumor heterogeneity. TAN-high LUSC had frequent PIK3CA mutations. TAN-high tumors harbored recently expanded and metastasis-seeding subclones and had a shorter disease-free survival independent of stage. These findings delineate genomic, immune, and physical barriers to immune surveillance and implicate neutrophil-rich TMEs in metastasis.

SIGNIFICANCE

This study provides novel insights into the spatial organization of the lung cancer TME in the context of tumor immunogenicity, tumor heterogeneity, and cancer evolution. Pairing the tumor evolutionary history with the spatially resolved TME suggests mechanistic hypotheses for tumor progression and metastasis with implications for patient outcome and treatment. This article is featured in Selected Articles from This Issue, p. 897.

Characterization of extracellular trap production and release by equine neutrophils in response to different stimuli

This study explores Neutrophil Extracellular Trap (NET) formation in equine neutrophils, which is crucial for eliminating infections and is implicated in various equine inflammatory diseases. We investigated the molecular pathways involved in NET release by equine neutrophils in response to stimuli. We use PMA, A23187, LPS, PAF, OZ, and cytokines, observing NET release in response to PMA, PAF, and A23187. In contrast, LPS, OZ, and the cytokines tested did not induce DNA release or did not consistently induce citrullination of histone 4. Peptidyl-arginine deiminase inhibition completely halted NET release, while NADPH oxidase and mitochondrial reactive oxygen species only played a role in PMA-induced NETs. Neutrophil elastase inhibition modestly affected PAF-induced NET liberation but not in PMA or A23187-induced NET, while myeloperoxidase did not contribute to NET release. We expect to provide a foundation for future investigations into the role of NETs in equine health and disease and the search for potential therapeutic targets.

Integrative analysis indicates the potential values of ANKRD53 in stomach adenocarcinoma

BACKGROUND

Ankyrin repeat domain 53 (ANKRD53) plays an important role in maintaining chromosome integrity and stability, and chromosome instability is associated with cancer. Through integrative analysis, this study investigates the potential value of ANKRD53 in stomach adenocarcinoma (STAD).

METHODS

RNA-seq and scRNA-seq data were used for integrative analysis based on online databases. Expression of ANKRD53 was confirmed by RT-PCR after bioinformatic analysis. Kaplan-Meier and Cox regression analyses were performed to evaluate the prognostic value of ANKRD53 in STAD. Gene set enrichment analysis (GSEA) was performed to evaluate ANKRD53-related signaling pathways. In addition, the interaction of ANKRD53 with immunity was also investigated.

RESULTS

RT-PCR in STAD cell lines confirmed that ANKRD53 was downregulated in STAD samples compared to normal samples in the online databases. As an independent predictive biomarker, ANKRD53 was combined with other clinicopathological parameters to create a prognostic nomogram. Using GSEA, ANKRD53 was found to be involved in five pathways, including the TGF-β signaling pathway. Further investigation revealed that ANKRD53 was associated with immune checkpoint molecules, immunological pathways, and immunotherapy, in addition to MSI, TMB and neoantigens. In addition, scRNA-seq data revealed that ANKRD53 is mainly expressed in CD8+ T and dendritic cells.

CONCLUSIONS

ANKRD53 is an important biomarker for STAD that deserves further attention.

A β-Carboline Derivate PAD4 Inhibitor Reshapes Neutrophil Phenotype and Improves the Tumor Immune Microenvironment against Triple-Negative Breast Cancer

Triple-negative breast cancer is a highly aggressive and heterogeneous breast cancer subtype characterized by early metastasis, poor prognosis, and high recurrence. Targeting histone citrullination-mediated chromatin dysregulation to induce epigenetic alterations shows great promise in TNBC therapy. We report the synthesis, optimization, and evaluation of a novel series of β-carboline-derived peptidyl arginine deiminase 4 inhibitors that exhibited potent inhibition of TNBC cell proliferation. The most outstanding PAD4 inhibitor, compound 28, hindered the PAD4-H3cit-NET signaling pathway and inhibited the growth of solid tumors and pulmonary metastatic nodules in the 4T1 in situ mouse model. Furthermore, 28 improved the tumor immune microenvironment by reshaping neutrophil phenotype, upregulating the proportions of dendritic cells and M1 macrophages, and reducing the amount of myeloid-derived suppressor cells. In conclusion, our work offered 28 as an efficacious PAD4 inhibitor that exerts a combination of conventional chemotherapy and immune-boosting effects, which represents a potential therapy strategy for TNBC.

Tumor-neutrophil cross talk orchestrates the tumor microenvironment to determine the bladder cancer progression

The immune landscape of bladder cancer progression is not fully understood, and effective therapies are lacking in advanced bladder cancer. Here, we visualized that bladder cancer cells recruited neutrophils by secreting interleukin-8 (IL-8); in turn, neutrophils played dual functions in bladder cancer, including hepatocyte growth factor (HGF) release and CCL3highPD-L1high super-immunosuppressive subset formation. Mechanistically, c-Fos was identified as the mediator of HGF up-regulating IL-8 transcription in bladder cancer cells, which was central to the positive feedback of neutrophil recruitment. Clinically, compared with serum IL-8, urine IL-8 was a better biomarker for bladder cancer prognosis and clinical benefit of immune checkpoint blockade (ICB). Additionally, targeting neutrophils or hepatocyte growth factor receptor (MET) signaling combined with ICB inhibited bladder cancer progression and boosted the antitumor effect of CD8+ T cells in mice. These findings reveal the mechanism by which tumor-neutrophil cross talk orchestrates the bladder cancer microenvironment and provide combination strategies, which may have broad impacts on patients suffering from malignancies enriched with neutrophils.

Association of pretreatment neutrophil-to-lymphocyte ratio with clinical outcomes in cancer immunotherapy: An evidence synthesis from 30 meta-analyses

BACKGROUND

The Neutrophil-to-lymphocyte ratio (NLR) holds relevance in cancer immunotherapy outcomes, yet its validation remains limited. Thus, we conducted an umbrella review to comprehensively assess the association between pretreatment NLR and immunotherapy outcomes, along with evaluating their credibility and strength.

METHODS

Electronic databases, including PubMed, Web of Science, Embase, Scopus, and Cochrane, were systematically searched for eligible systematic reviews and meta-analyses. Quality assessment and evidence grading utilized AMSTAR, GRADE, and additional classification criteria, following PRISMA and PRIOR guidelines.

RESULTS

Thirty unique meta-analyses were included, with 24 associations (80%) exhibiting statistical significance. Notably, associations between pretreatment NLR and the prognosis of renal cell carcinoma, hepatocellular carcinoma, melanoma, and non-small cell lung cancer garnered highly suggestive or convincing evidence grading.

CONCLUSIONS

Elevated pretreatment NLR correlates with poor outcomes in cancer immunotherapy, suggesting its potential as a biomarker for identifying appropriate treatment populations and predicting clinical outcomes. Nevertheless, further validation through prospective cohort studies is warranted.

CD276 regulates the immune escape of esophageal squamous cell carcinoma through CXCL1-CXCR2 induced NETs

BACKGROUND

CD276 (B7-H3), a pivotal immune checkpoint, facilitates tumorigenicity, invasiveness, and metastasis by escaping immune surveillance in a variety of tumors; however, the underlying mechanisms facilitating immune escape in esophageal squamous cell carcinoma (ESCC) remain enigmatic.

METHODS

We investigated the expression of CD276 in ESCC tissues from patients by using immunohistochemistry (IHC) assays. In vivo, we established a 4-nitroquinoline 1-oxide (4NQO)-induced CD276 knockout (CD276wKO) and K14cre; CD276 conditional knockout (CD276cKO) mouse model of ESCC to study the functional role of CD276 in ESCC. Furthermore, we used the 4NQO-induced mouse model to evaluate the effects of anti-CXCL1 antibodies, anti-Ly6G antibodies, anti-NK1.1 antibodies, and GSK484 inhibitors on tumor growth. Moreover, IHC, flow cytometry, and immunofluorescence techniques were employed to measure immune cell proportions in ESCC. In addition, we conducted single-cell RNA sequencing analysis to examine the alterations in tumor microenvironment following CD276 depletion.

RESULTS

In this study, we elucidate that CD276 is markedly upregulated in ESCC, correlating with poor prognosis. In vivo, our results indicate that depletion of CD276 inhibits tumorigenesis and progression of ESCC. Furthermore, conditional knockout of CD276 in epithelial cells engenders a significant downregulation of CXCL1, consequently reducing the formation of neutrophil extracellular trap networks (NETs) via the CXCL1-CXCR2 signaling axis, while simultaneously augmenting natural killer (NK) cells. In addition, overexpression of CD276 promotes tumorigenesis via increasing NETs' formation and reducing NK cells in vivo.

CONCLUSIONS

This study successfully elucidates the functional role of CD276 in ESCC. Our comprehensive analysis uncovers the significant role of CD276 in modulating immune surveillance mechanisms in ESCC, thereby suggesting that targeting CD276 might serve as a potential therapeutic approach for ESCC treatment.

Enhanced lipid biosynthesis in oral squamous cell carcinoma cancer-associated fibroblasts contributes to tumor progression: Role of IL8/AKT/p-ACLY axis

Lipid metabolic reprogramming of tumor cells has been proven to play a critical role in tumor initiation and development. However, lipid metabolism in cancer-associated fibroblasts (CAFs) has rarely been studied, particularly in CAFs of oral squamous cell carcinoma (OSCC). Additionally, the molecular mechanism by which tumor cells regulate lipid metabolism in fibroblasts is unclear. In this study, we found that phosphorylated ATP citrate lyase (p-ACLY), a key lipid metabolic enzyme, was upregulated in OSCC CAFs. Compared to paracancerous normal fibroblasts, CAFs showed enhanced lipid synthesis, such as elevated cytosolic acetyl-CoA level and accumulation of lipid droplets. Conversely, reduction of p-ACLY level blocked this biological process. In addition, blocking lipid synthesis in CAFs or inhibiting fatty acid uptake by OSCC cells reduced the promotive effects of CAFs on OSCC cell proliferation, invasion, and migration. These findings suggested that CAFs are one of lipid sources required for OSCC progression. Mechanistically, AKT signaling activation was involved in the upregulation of p-ACLY level and lipid synthesis in CAFs. Interleukin-8 (IL8), an exocrine cytokine of OSCC cells, could activate AKT and then phosphorylate ACLY in fibroblasts. This study suggested that the IL8/AKT/p-ACLY axis could be considered as a potential target for OSCC treatment.

Rapidly Evolving Pre- and Post-surgical Systemic Treatment of Melanoma

With the development of effective BRAF-targeted and immune-checkpoint immunotherapies for metastatic melanoma, clinical trials are moving these treatments into earlier adjuvant and perioperative settings. BRAF-targeted therapy is a standard of care in resected stage III-IV melanoma, while anti-programmed death-1 (PD1) immunotherapy is now a standard of care option in resected stage IIB through IV disease. With both modalities, recurrence-free survival and distant-metastasis-free survival are improved by a relative 35-50%, yet no improvement in overall survival has been demonstrated. Neoadjuvant anti-PD1 therapy improves event-free survival by approximately an absolute 23%, although improvements in overall survival have yet to be demonstrated. Understanding which patients are most likely to recur and which are most likely to benefit from treatment is now the highest priority question in the field. Biomarker analyses, such as gene expression profiling of the primary lesion and circulating DNA, are preliminarily exciting as potential biomarkers, though each has drawbacks. As in the setting of metastatic disease, markers that inform positive outcomes include interferon-γ gene expression, PD-L1, and high tumor mutational burden, while negative predictors of outcome include circulating factors such as lactate dehydrogenase, interleukin-8, and C-reactive protein. Integrating and validating these markers into clinically relevant models is thus a high priority. Melanoma therapeutics continues to advance with combination adjuvant approaches now investigating anti-PD1 with lymphocyte activation gene 3 (LAG3), T-cell immunoreceptor with Ig and ITIM domains (TIGIT), and individualized neoantigen therapies. How this progress will be integrated into the management of a unique patient to reduce recurrence, limit toxicity, and avoid over-treatment will dominate clinical research and patient care over the next decade.

Cx1Mab-1: A Novel Anti-mouse CXCR1 Monoclonal Antibody for Flow Cytometry

The C-X-C motif chemokine receptor-1 (CXCR1) is a rhodopsin-like G-protein-coupled receptor, expressed on the cell surface of immune cells and tumors. CXCR1 interacts with some C-X-C chemokines, such as CXCL6, CXCL7, and CXCL8/interleukin-8, which are produced by various cells. Since CXCR1 is involved in several diseases including tumors and diabetes mellitus, drugs targeting CXCR1 have been developed. Therefore, the development of sensitive monoclonal antibodies (mAbs) for CXCR1 has been desired for the diagnosis and treatment. This study established a novel anti-mouse CXCR1 (mCXCR1) mAb, Cx1Mab-1 (rat IgG1, kappa), using the Cell-Based Immunization and Screening method. Cx1Mab-1 reacted with mCXCR1-overexpressed Chinese hamster ovary-K1 (CHO/mCXCR1) and mCXCR1-overexpressed LN229 glioblastoma (LN229/mCXCR1) in flow cytometry. Cx1Mab-1 demonstrated a high binding affinity for CHO/mCXCR1 and LN229/mCXCR1 with a dissociation constant of 2.6 × 10-9 M and 2.1 × 10-8 M, respectively. Furthermore, Cx1Mab-1 could detect mCXCR1 by Western blot analysis. These results indicated that Cx1Mab-1 is useful for detecting mCXCR1, and provides a possibility for targeting mCXCR1-expressing cells in vivo experiments.