Invariant NKT cells modulate the suppressive activity of IL-10-secreting neutrophils differentiated with serum amyloid A

Tamdy virus pathogenesis in immunocompetent and immunocompromised mouse models

Tamdy virus (TAMV) is one of the zoonotic tick-borne bunyaviruses that have emerged as global public health threats in recent decades. To date, however, TAMV pathogenesis remains poorly understood. In the present study, we have established different mouse infection models to enable investigation of TAMV pathogenesis. Adult BALB/c mice did not exhibit obvious clinical symptoms or signs post-TAMV infection. In contrast, adult type I interferon receptor knockout (IFNAR-/-) A129 mice were found to be susceptible to high-doses of TAMV (6 × 102 and 6 × 104 FFU) and all developed severe clinical symptoms and signs, including weight loss and immobility, and reached the euthanasia criteria at 4/5-day post-infection (dpi). Viral RNA was detected in peripheral blood and different tissues (heart, liver, spleen, lung, kidney, intestine, and brain) of the high-dose infected adult A129 mice, with the highest viral loads in the liver (approximately 108.3 copies/μL). Pathological examination also revealed severe liver damage in the high-dose infected A129 mice. In addition, the titres of TAMV-specific IgM and IgG antibodies increased rapidly 4-5 dpi. Analysis of cytokine and chemokine expression changes demonstrated that type I IFN may play an important role in the host defence against viral infection by enhancing IL-10 production. Gene ontology and KEGG analyses showed that liver injury may be associated with virus-induced expression of inflammatory cytokines and chemokines. Together, we have investigated TAMV pathogenesis using immunocompetent and immunocompromised mouse models, which will facilitate the development of TAMV-specific antivirals and vaccines.

The role of natural killer T cells in sepsis-associated acute kidney injury

The condition of sepsis, defined by the misregulation of the body's defensive mechanisms against infection, culminates in the potential for catastrophic organ damage and stands as a primary driver of mortality in Intensive Care Units (ICU) settings. Among patients in a critical condition, sepsis is a predominant factor in the development of acute kidney injury (AKI), and the death rate among those with both sepsis and AKI is considerably higher, underscoring the importance of addressing this health crisis. Sepsis-associated acute kidney injury (S-AKI) is a complex process involving inflammation, microcirculatory issues, and metabolic disorders. Among these, the inflammatory response has become a focal point of interest. Bridging the innate and adaptive immunity, natural killer T (NKT) cells can be rapidly activated in sepsis, contributing to sepsis-associated injury and downstream activation of inflammatory cells through the emission of Th1 or Th2 cytokines. They also contribute to S-AKI through the TNF-α/FasL and perforin pathways. Alpha-Galactosylceramide (α-GalCer), acting as a powerful activator for type I NKT (iNKT) cells, is able to regulate the secretory profile of iNKT cells, responding to the pro-inflammatory response and immunosuppressive profiles of sepsis. This review examines the part played by NKT cells in S-AKI and whether α-Galcer could function as a significant regulator in sepsis, based on studies of regression-related mechanisms.

Bmal1 deficiency in neutrophils alleviates symptoms induced by high-fat diet

Physiological processes, including metabolism and immune responses, are generated by the circadian clock, driven by clock genes. Disrupting circadian rhythms through a high-fat diet promotes obesity and inflammation. Studies show that deleting the clock gene, brain, and muscle ARNT-like 1 (Bmal1) in adipose tissue leads to overeating and weight gain. We now show that Bmal1 deletion in neutrophils protects against diet-induced obesity and reduces inflammatory macrophage infiltration into epididymal white adipose tissue (eWAT), despite increased food intake over 20 weeks of a high-fat diet. This protection is linked to enhanced energy expenditure, increased UCP1 expression in iBAT, improved insulin sensitivity, and altered expression of genes encoding chemokine receptors CXCR2, CXCR4, and the ligand Cxcl2 in eWAT. Our findings reveal a key role of Bmal1 in neutrophils in regulating high-fat diet-induced adipose inflammation and emphasize circadian regulation's importance in immuno-metabolic function.

Invasion and metastasis in cancer: molecular insights and therapeutic targets

The progression of malignant tumors leads to the development of secondary tumors in various organs, including bones, the brain, liver, and lungs. This metastatic process severely impacts the prognosis of patients, significantly affecting their quality of life and survival rates. Research efforts have consistently focused on the intricate mechanisms underlying this process and the corresponding clinical management strategies. Consequently, a comprehensive understanding of the biological foundations of tumor metastasis, identification of pivotal signaling pathways, and systematic evaluation of existing and emerging therapeutic strategies are paramount to enhancing the overall diagnostic and treatment capabilities for metastatic tumors. However, current research is primarily focused on metastasis within specific cancer types, leaving significant gaps in our understanding of the complex metastatic cascade, organ-specific tropism mechanisms, and the development of targeted treatments. In this study, we examine the sequential processes of tumor metastasis, elucidate the underlying mechanisms driving organ-tropic metastasis, and systematically analyze therapeutic strategies for metastatic tumors, including those tailored to specific organ involvement. Subsequently, we synthesize the most recent advances in emerging therapeutic technologies for tumor metastasis and analyze the challenges and opportunities encountered in clinical research pertaining to bone metastasis. Our objective is to offer insights that can inform future research and clinical practice in this crucial field.

The Roles of Myeloid Cells in Breast Cancer Progression

This chapter reviews tumor-associated myeloid cells, including macrophages, neutrophils, and other innate immune cells, and their multifaceted roles in supporting breast cancer progression and metastasis. In primary tumors, myeloid cells play key roles in promoting tumor epithelial-mesenchymal transition (EMT) and invasion. They can facilitate intravasation (entry into the bloodstream) and colonization, disrupting the endothelial cell layer and reshaping the extracellular matrix. They can also stimulate angiogenesis, suppress immune cell responses, and enhance cancer cell adaptability. In the bloodstream, circulating myeloid cells enable the survival of disseminated tumor cells via immunosuppressive effects and physical shielding. At the metastatic sites, they prime the premetastatic niche, facilitate tumor cell extravasation, and support successful colonization and outgrowth. Mechanistically, myeloid cells enhance cancer cell survival, dormancy escape, proliferation, and mesenchymal-epithelial transition (MET). Nonetheless, substantial gaps in our understanding persist regarding the functional and spatiotemporal diversity, as well as the evolutionary patterns, of myeloid cells during metastatic progression. Myeloid cell plasticity and differential responses to therapies present key barriers to successful treatments. Identifying specific pro-tumoral myeloid cell subpopulations and disrupting their interactions with cancer cells represent promising therapeutic opportunities. Emerging evidence suggests combining immunomodulators or stromal normalizers with conventional therapies could help overcome therapy-induced immunosuppression and improve patient outcomes. Overall, further elucidating myeloid cell heterogeneity and function throughout the process of breast cancer progression and metastasis will enable more effective therapeutic targeting of these critical stromal cells.

Advancements in adoptive CAR immune cell immunotherapy synergistically combined with multimodal approaches for tumor treatment

Adoptive immunotherapy, notably involving chimeric antigen receptor (CAR)-T cells, has obtained Food and Drug Administration (FDA) approval as a treatment for various hematological malignancies, demonstrating promising preclinical efficacy against cancers. However, the intricate and resource-intensive autologous cell processing, encompassing collection, expansion, engineering, isolation, and administration, hamper the efficacy of this therapeutic modality. Furthermore, conventional CAR T therapy is presently confined to addressing solid tumors due to impediments posed by physical barriers, the potential for cytokine release syndrome, and cellular exhaustion induced by the immunosuppressive and heterogeneous tumor microenvironment. Consequently, a strategic integration of adoptive immunotherapy with synergistic multimodal treatments, such as chemotherapy, radiotherapy, and vaccine therapy etc., emerges as a pivotal approach to surmount these inherent challenges. This collaborative strategy holds the key to addressing the limitations delineated above, thereby facilitating the realization of more precise personalized therapies characterized by heightened therapeutic efficacy. Such synergistic strategy not only serves to mitigate the constraints associated with adoptive immunotherapy but also fosters enhanced clinical applicability, thereby advancing the frontiers of therapeutic precision and effectiveness.

Optimizing iNKT-driven immune responses against cancer by modulating CD1d in tumor and antigen presenting cells

Two major antigen processing pathways represent protein Ags through major histocompatibility complexes (MHC class I and II) or lipid Ags through CD1 molecules influence the tumor immune response. Invariant Natural Killer T cells (iNKT) manage a significant role in cancer immunotherapy. CD1d, found on antigen-presenting cells (APCs), presents lipid Ags to iNKT cells. In many cancers, the number and function of iNKT cell are compromised, leading to immune evasion. Additionally impaired motility of iNKT cells may contribute to poor tumor prognosis. Emerging evidences suggest that CD1d, itself also influences cancer progression. Patient databases further highlight the importance of CD1d expression in different cancers and its correlation with patient survival outcomes. The ability of iNKT cells to activate and enhance the immune response renders them an attractive target for cancer immunotherapy. This review discusses all the possible ways of cancer immune evasion and restoration of immune responses mediated by CD1d-iNKT interactions.

Triggering Toll-Like Receptor 5 Signaling During Pneumococcal Superinfection Prevents the Selection of Antibiotic Resistance

Toll-like receptor 5 (TLR5) signaling plays a key role in antibacterial defenses. We previously showed that respiratory administration of flagellin, a potent TLR5 agonist, in combination with amoxicillin (AMX) improves the treatment of primary pneumonia or superinfection caused by AMX-sensitive or AMX-resistant Streptococcus pneumoniae. Here, the impact of adjunct flagellin therapy on antibiotic dose/regimen and the selection of antibiotic-resistant S. pneumoniae was investigated using superinfection with isogenic antibiotic-sensitive and antibiotic-resistant bacteria and population dynamics analysis. Our findings demonstrate that flagellin allows for a 200-fold reduction in the antibiotic dose, achieving the same therapeutic effect observed with antibiotic alone. Adjunct treatment also reduced the selection of antibiotic-resistant bacteria in contrast to the antibiotic monotherapy. A mathematical model was developed that captured the population dynamics and estimated a 20-fold enhancement immune-modulatory factor on bacterial clearance. This work paves the way for the development of host-directed therapy and refinement of treatment by modeling.

Neutrophil Hitchhiking Enhances Liposomal Dexamethasone Therapy of Sepsis

Sepsis is characterized by a dysregulated immune response and is very difficult to treat. In the cecal ligation and puncture (CLP) mouse model, we show that nanomedicines can effectively alleviate systemic and local septic events by targeting neutrophils. Specifically, by decorating the surface of clinical-stage dexamethasone liposomes with cyclic arginine-glycine-aspartic acid (cRGD) peptides, we promote their engagement with neutrophils in the systemic circulation, leading to their prominent accumulation at primary and secondary sepsis sites. cRGD-targeted dexamethasone liposomes potently reduce immature circulating neutrophils and neutrophil extracellular traps in intestinal sepsis induction sites and the liver. Additionally, they mitigate inflammatory cytokines systemically and locally while preserving systemic IL-10 levels, contributing to lower IFN-γ/IL-10 ratios as compared to control liposomes and free dexamethasone. Our strategy addresses sepsis at the cellular level, illustrating the use of neutrophils both as a therapeutic target and as a chariot for drug delivery.

Serum amyloid A promotes glycolysis of neutrophils during PD-1 blockade resistance in hepatocellular carcinoma

The response to programmed death-1 (PD-1) blockade varies in hepatocellular carcinoma (HCC). We utilize a panel of 16 serum factors to show that a circulating level of serum amyloid A (SAA) > 20.0 mg/L has the highest accuracy in predicting anti-PD-1 resistance in HCC. Further experiments show a correlation between peritumoral SAA expression and circulating SAA levels in patients with progressive disease after PD-1 inhibition. In vitro experiments demonstrate that SAA induces neutrophils to express PD-L1 through glycolytic activation via an LDHA/STAT3 pathway and to release oncostatin M, thereby attenuating cytotoxic T cell function. In vivo, genetic or pharmacological inhibition of STAT3 or SAA eliminates neutrophil-mediated immunosuppression and enhances antitumor efficacy of anti-PD-1 treatment. This study indicates that SAA may be a critical inflammatory cytokine implicated in anti-PD-1 resistance in HCC. Targeting SAA-induced PD-L1+ neutrophils through STAT3 or SAA inhibition may present a potential approach for overcoming anti-PD1 resistance.

T Cell Receptor-Engaging Monoclonal Antibodies Mobilize the Anti-Tumor Functions of Invariant Natural Killer T Cells

Invariant natural killer T cells (iNKTs) are innate-type T lymphocytes that directly kill tumor cells or tumor-growth promoting immunosuppressive cells such astumor-associated macrophages. Additionally, iNKTs robustly transactivate the antitumor functions of T, B, natural killer, and dendritic cells as well as reinvigorate exhausted immune cells in the tumor microenvironment. As such, iNKTs make excellent candidates for inclusion in anti-cancer cellular therapies. However, to capitalize on the potential benefits of iNKT cell-based approaches, it is imperative that we develop new and clinically viable strategies to enhance their antitumor function. To that end, two novel monoclonal antibodies (mAbs) that selectively bind to the human (NKTT320) or murine (NKT14m) invariant T cell receptor have been recently developed and characterized. Studies using purified human iNKTs (in vitro) and a model of non-human primate (in vivo) reveal that NKTT320 promotes swift, vigorous and sustained iNKT cell activation that is accompanied by robust production of inflammatory mediators and bystander immune cell activation. Furthermore, NKTT320 augments expression of cytotoxic markers and human iNKT cell degranulation. Similarly, NKT14m prompts dramatic murine iNKT cell activation and functional response both in vitro and in vivo. However, antitumor efficacy of a single dose of NKT14m injection in tumor-bearing mice is limited and tumor-model dependent. In contrast, combination treatment of NKT14m with either low dose interleukin (IL)-12 or the chemotherapeutic agent, cyclophosphamide results in a superior antitumor response in vivo. This is evident by activation of both iNKTs and other immune cells, prolonged survival of the tumor-challenged mice, and long-lasting immunity. Collectively, these recent studies justify further development of anti-iTCR mAbs that can be used alone or in conjunction with immunomodulatory agents to enhance iNKT cell antitumor immunity against various cancers.

Plasma metabolomic profiling of patients with transient ischemic attack reveals positive role of neutrophils in ischemic tolerance

BACKGROUND

Transient ischemic attack (TIA) induces ischemic tolerance that can reduce the subsequent ischemic damage and improve prognosis of patients with stroke. However, the underlying mechanisms remain elusive. Recent advances in plasma metabolomics analysis have made it a powerful tool to investigate human pathophysiological phenotypes and mechanisms of diseases. In this study, we aimed to identify the bioactive metabolites from the plasma of patients with TIA for determination of their prophylactic and therapeutic effects on protection against cerebral ischemic stroke, and the mechanism of TIA-induced ischemic tolerance against subsequent stroke.

METHODS

Metabolomic profiling using liquid chromatography-mass spectrometry was performed to identify the TIA-induced differential bioactive metabolites in the plasma samples of 20 patients at day 1 (time for basal metabolites) and day 7 (time for established chronic ischemic tolerance-associated metabolites) after onset of TIA. Mouse middle cerebral artery occlusion (MCAO)-induced stroke model was used to verify their prophylactic and therapeutic potentials. Transcriptomics changes in circulating neutrophils of patients with TIA were determined by RNA-sequencing. Multivariate statistics and integrative analysis of metabolomics and transcriptomics were performed to elucidate the potential mechanism of TIA-induced ischemic tolerance.

FINDINGS

Plasma metabolomics analysis identified five differentially upregulated metabolites associated with potentially TIA-induced ischemic tolerance, namely all-trans 13,14 dihydroretinol (atDR), 20-carboxyleukotriene B4, prostaglandin B2, cortisol and 9-KODE. They were associated with the metabolic pathways of retinol, arachidonic acid, and neuroactive ligand-receptor interaction. Prophylactic treatment of MCAO mice with these five metabolites significantly improved neurological functions. Additionally, post-stroke treatment with atDR or 9-KODE significantly reduced the cerebral infarct size and enhanced sensorimotor functions, demonstrating the therapeutic potential of these bioactive metabolites. Mechanistically, we found in patients with TIA that these metabolites were positively correlated with circulating neutrophil counts. Integrative analysis of plasma metabolomics and neutrophil transcriptomics further revealed that TIA-induced metabolites are significantly correlated with specific gene expression in circulating neutrophils which showed prominent enrichment in FoxO signaling pathway and upregulation of the anti-inflammatory cytokine IL-10. Finally, we demonstrated that the protective effect of atDR-pretreatment on MCAO mice was abolished when circulating neutrophils were depleted.

INTERPRETATION

TIA-induced potential ischemic tolerance is associated with upregulation of plasma bioactive metabolites which can protect against cerebral ischemic damage and improve neurological functions through a positive role of circulating neutrophils.

FUNDING

National Natural Science Foundation of China (81974210), Science and Technology Planning Project of Guangdong Province, China (2020A0505100045), Natural Science Foundation of Guangdong Province (2019A1515010671), Science and Technology Program of Guangzhou, China (2023A03J0577), and Natural Science Foundation of Jiangxi, China（20224BAB216043).

Primary Mouse Invariant Natural Killer T (iNKT) Cell Purification and Transduction

Invariant natural killer T (iNKT) cells are a non-conventional T-cell population expressing a conserved semi-invariant T-cell receptor (TCR) that reacts to lipid antigens, such as α-galactosyl ceramide (α-GalCer), presented by the monomorphic molecule CD1d. iNKT cells play a central role in tumor immunosurveillance and represent a powerful tool for anti-cancer treatment, notably because they can be efficiently redirected against hematological or solid malignancies by engineering with tumor-specific chimeric antigen receptors (CARs) or TCRs. However, iNKT cells are rare and require specific ex vivo pre-selection and substantial in vitro expansion to be exploited for adoptive cell therapy (ACT). This protocol describes a robust method to obtain a large number of mouse iNKT cells that can be effectually engineered by retroviral (RV) transduction. A major advantage of this protocol is that it requires neither particular instrumentation nor a high number of mice. iNKT cells are enriched from the spleens of iVα14-Jα18 transgenic mice; the rapid purification protocol yields a highly enriched iNKT cell population that is activated by anti-CD3/CD28 beads, which is more reproducible and less time consuming than using bone marrow-derived dendritic cells loaded with α-GalCer, without risks of expanding contaminant T cells. Forty-eight hours after activation, iNKT cells are transduced with the selected RV by spin inoculation. This protocol allows to obtain, in 15 days, millions of ready-to-use, highly pure, and stably transduced iNKT cells that might be exploited for in vitro assays and ACT experiments in preclinical studies.

iNKT cell-neutrophil crosstalk promotes colorectal cancer pathogenesis

iNKT cells account for a relevant fraction of effector T-cells in the intestine and are considered an attractive platform for cancer immunotherapy. Although iNKT cells are cytotoxic lymphocytes, their functional role in colorectal cancer (CRC) is still controversial, limiting their therapeutic use. Thus, we examined the immune cell composition and iNKT cell phenotype of CRC lesions in patients (n = 118) and different murine models. High-dimensional single-cell flow-cytometry, metagenomics, and RNA sequencing experiments revealed that iNKT cells are enriched in tumor lesions. The tumor-associated pathobiont Fusobacterium nucleatum induces IL-17 and Granulocyte-macrophage colony-stimulating factor (GM-CSF) expression in iNKT cells without affecting their cytotoxic capability but promoting iNKT-mediated recruitment of neutrophils with polymorphonuclear myeloid-derived suppressor cells-like phenotype and functions. The lack of iNKT cells reduced the tumor burden and recruitment of immune suppressive neutrophils. iNKT cells in-vivo activation with α-galactosylceramide restored their anti-tumor function, suggesting that iNKT cells can be modulated to overcome CRC-associated immune evasion. Tumor co-infiltration by iNKT cells and neutrophils correlates with negative clinical outcomes, highlighting the importance of iNKT cells in the pathophysiology of CRC. Our results reveal a functional plasticity of iNKT cells in CRC, suggesting a pivotal role of iNKT cells in shaping the tumor microenvironment, with relevant implications for treatment.

The circadian neutrophil, inside-out

The circadian clock has sway on a myriad of physiological targets, among which the immune and inflammatory systems are particularly prominent. In this review, we discuss how neutrophils, the wildcard of the immune system, are regulated by circadian oscillations. We describe cell-intrinsic and extrinsic diurnal mechanisms governing the general physiology and function of these cells, from purely immune to homeostatic. Repurposing the concepts discovered in other cell types, we then speculate on various uncharted avenues of neutrophil-circadian relationships, such as topology, metabolism, and the regulation of tissue clocks, with the hope of identifying exciting new avenues of work in the context of circadian immunity.

Tumor-neutrophil crosstalk promotes in vitro and in vivo glioblastoma progression

Introduction

The tumor microenvironment (TME) of glioblastoma (GB) is characterized by an increased infiltration of immunosuppressive cells that attenuate the antitumor immune response. The participation of neutrophils in tumor progression is still controversial and a dual role in the TME has been proposed. In this study, we show that neutrophils are reprogrammed by the tumor to ultimately promote GB progression.

Methods

Using in vitro and in vivo assays, we demonstrate the existence of bidirectional GB and neutrophil communication, directly promoting an immunosuppressive TME.

Results and discussion

Neutrophils have shown to play an important role in tumor malignancy especially in advanced 3D tumor model and Balb/c nude mice experiments, implying a time- and neutrophil concentration-dependent modulation. Studying the tumor energetic metabolism indicated a mitochondria mismatch shaping the TME secretome. The given data suggests a cytokine milieu in patients with GB that favors the recruitment of neutrophils, sustaining an anti-inflammatory profile which is associated with poor prognosis. Besides, glioma-neutrophil crosstalk has sustained a tumor prolonged activation via NETs formation, indicating the role of NFκB signaling in tumor progression. Moreover, clinical samples have indicated that neutrophil-lymphocyte ratio (NLR), IL-1β, and IL-10 are associated with poor outcomes in patients with GB.

Conclusion

These results are relevant for understanding how tumor progression occurs and how immune cells can help in this process.

Pathogenic NKT cells attenuate urogenital chlamydial clearance and enhance infertility

Urogenital chlamydial infections continue to increase with over 127 million people affected annually, causing significant economic and public health pressures. While the role of traditional MHCI and II peptide presentation is well defined in chlamydial infections, the role of lipid antigens in immunity remains unclear. Natural killer (NK) T cells are important effector cells that recognize and respond to lipid antigens during infections. Chlamydial infection of antigen-presenting cells facilitates presentation of lipid on the MHCI-like protein, CD1d, which stimulates NKT cells to respond. During urogenital chlamydial infection, wild-type (WT) female mice had significantly greater chlamydial burden than CD1d-/- (NKT-deficient) mice, and had significantly greater incidence and severity of immunopathology in both primary and secondary infections. WT mice had similar vaginal lymphocytic infiltrate, but 59% more oviduct occlusion compared to CD1d-/- mice. Transcriptional array analysis of oviducts day 6 post-infection revealed WT mice had elevated levels of Ifnγ (6-fold), Tnfα (38-fold), Il6 (2.5-fold), Il1β (3-fold) and Il17a (6-fold) mRNA compared to CD1d-/- mice. In infected females, oviduct tissues had an elevated infiltration of CD4+ -invariant NKT (iNKT) cells, however, iNKT-deficient Jα18-/- mice had no significant differences in hydrosalpinx severity or incidence compared to WT controls. Lipid mass spectrometry of surface-cleaved CD1d in infected macrophages revealed an enhancement of presented lipids and cellular sequestration of sphingomyelin. Taken together, these data suggest an immunopathogenic role for non-invariant NKT cells in urogenital chlamydial infections, facilitated by lipid presentation via CD1d via infected antigen-presenting cells.

Massively recruited sTLR9+ neutrophils in rapidly formed nodules at the site of tumor cell inoculation and their contribution to a pro-tumor microenvironment

Neutrophils exert either pro- or anti-tumor activities. However, few studies have focused on neutrophils at the tumor initiation stage. In this study, we unexpectedly found a subcutaneous nodule in the groin areas of mice inoculated with tumor cells. The nodule was developed 24 h after the inoculation, filled with tumor cells and massively recruited neutrophils, being designated as tumor nodules. 22% of the neutrophils in tumor nodules are surface TLR9 (sTLR9) expressing neutrophils (sTLR9⁺ neutrophils). With tumor progression, sTLR9⁺ neutrophils were sustainably increased in tumor nodules/tumor tissues, reaching to 90.8% on day 13 after inoculation, with increased expression of IL-10 and decreased or no expression of TNFα. In vivo administration of CpG 5805 significantly reduced sTLR9 expression of the sTLR9⁺ neutrophils. The reduction of sTLR9 on neutrophils in tumor nodules contributed to the induction of an anti-tumor microenvironment conductive to the inhibition of tumor growth. Overall, the study provides insights for understanding the role of sTLR9⁺ neutrophils in the tumor development, especially in the early stage.

Invariant NKT cells metabolically adapt to the acute myeloid leukaemia environment

Acute myeloid leukaemia (AML) creates an immunosuppressive environment to conventional T cells through Arginase 2 (ARG2)-induced arginine depletion. We identify that AML blasts release the acute phase protein serum amyloid A (SAA), which acts in an autocrine manner to upregulate ARG2 expression and activity, and promote AML blast viability. Following in vitro cross-talk invariant natural killer T (iNKT) cells become activated, upregulate mitochondrial capacity, and release IFN-γ. iNKT retain their ability to proliferate and be activated despite the low arginine AML environment, due to the upregulation of Large Neutral Amino Acid Transporter-1 (LAT-1) and Argininosuccinate Synthetase 1 (ASS)-dependent amino acid pathways, resulting in AML cell death. T cell proliferation is restored in vitro and in vivo. The capacity of iNKT cells to restore antigen-specific T cell immunity was similarly demonstrated against myeloid-derived suppressor cells (MDSCs) in wild-type and Jα18^-/- syngeneic lymphoma-bearing models in vivo. Thus, stimulation of iNKT cell activity has the potential as an immunotherapy against AML or as an adjunct to boost antigen-specific T cell immunotherapies in haematological or solid cancers.

Lactate in the tumor microenvironment: A rising star for targeted tumor therapy

Metabolic reprogramming is one of fourteen hallmarks of tumor cells, among which aerobic glycolysis, often known as the "Warburg effect," is essential to the fast proliferation and aggressive metastasis of tumor cells. Lactate, on the other hand, as a ubiquitous molecule in the tumor microenvironment (TME), is generated primarily by tumor cells undergoing glycolysis. To prevent intracellular acidification, malignant cells often remove lactate along with H⁺, yet the acidification of TME is inevitable. Not only does the highly concentrated lactate within the TME serve as a substrate to supply energy to the malignant cells, but it also works as a signal to activate multiple pathways that enhance tumor metastasis and invasion, intratumoral angiogenesis, as well as immune escape. In this review, we aim to discuss the latest findings on lactate metabolism in tumor cells, particularly the capacity of extracellular lactate to influence cells in the tumor microenvironment. In addition, we examine current treatment techniques employing existing medications that target and interfere with lactate generation and transport in cancer therapy. New research shows that targeting lactate metabolism, lactate-regulated cells, and lactate action pathways are viable cancer therapy strategies.

Role of NKT cells in cancer immunotherapy-from bench to bed

Natural killer T (NKT) cells are a specific T cell subset known to express the αβ-T cell receptor (TCR) for antigens identification and express typical NK cell specifications, such as surface expression of CD56 and CD16 markers as well as production of granzyme. Human NKT cells are divided into two subgroups based on their cytokine receptor and TCR repertoire. Both of them are CD1-restricted and recognize lipid antigens presented by CD1d molecules. Studies have demonstrated that these cells are essential in defense against malignancies. These cells secret proinflammatory and regulatory cytokines that stimulate or suppress immune system responses. In several murine tumor models, activation of type I NKT cells induces tumor rejection and inhibits metastasis's spread. However, type II NKT cells are associated with an inhibitory and regulatory function during tumor immune responses. Variant NKT cells may suppress tumor immunity via different mechanisms that require cross-talk with other immune-regulatory cells. NKT-like cells display high tumor-killing abilities against many tumor cells. In the recent decade, different studies have been performed based on the application of NKT-based immunotherapy for cancer therapy. Moreover, manipulation of NKT cells through administering autologous dendritic cell (DC) loaded with α-galactosylceramide (α-GalCer) and direct α-GalCer injection has also been tested. In this review, we described different subtypes of NKT cells, their function in the anti-tumor immune responses, and the application of NKT cells in cancer immunotherapy from bench to bed.

Sportomics method to assess acute phase proteins in Olympic level athletes using dried blood spots and multiplex assay

Sportomics is a subject-centered holistic method similar to metabolomics focusing on sports as the metabolic challenge. Dried blood spot is emerging as a technique due to its simplicity and reproducibility. In addition, mass spectrometry and integrative computational biology enhance our ability to understand exercise-induced modifications. We studied inflammatory blood proteins (Alpha-1-acid glycoprotein-A1AG1; Albumin; Cystatin C; C-reactive protein-CRP; Hemoglobin-HBA; Haptoglobin-HPT; Insulin-like growth factor 1; Lipopolysaccharide binding protein-LBP; Mannose-binding lectin-MBL2; Myeloperoxidase-PERM and Serum amyloid A1-SAA1), in 687 samples from 97 World-class and Olympic athletes across 16 sports in nine states. Data were analyzed with Spearman's rank-order correlation. Major correlations with CRP, LBP; MBL2; A1AG1, and SAA1 were found. The pairs CRP-SAA1 and CRP-LBP appeared with a robust positive correlation. Other pairs, LBP-SAA1; A1AG1-CRP; A1AG1-SAA1; A1AG1-MBL, and A1AG1-LBP, showed a broader correlation across the sports. The protein-protein interaction map revealed 1500 interactions with 44 core proteins, 30 of them linked to immune system processing. We propose that the inflammation follow-up in exercise can provide knowledge for internal cargo management in training, competition, recovery, doping control, and a deeper understanding of health and disease.

Neutrophil Extracellular Traps in Asthma: Friends or Foes?

Asthma is a chronic inflammatory disease characterized by variable airflow limitation and airway hyperresponsiveness. A plethora of immune and structural cells are involved in asthma pathogenesis. The roles of neutrophils and their mediators in different asthma phenotypes are largely unknown. Neutrophil extracellular traps (NETs) are net-like structures composed of DNA scaffolds, histones and granular proteins released by activated neutrophils. NETs were originally described as a process to entrap and kill a variety of microorganisms. NET formation can be achieved through a cell-death process, termed NETosis, or in association with the release of DNA from viable neutrophils. NETs can also promote the resolution of inflammation by degrading cytokines and chemokines. NETs have been implicated in the pathogenesis of various non-infectious conditions, including autoimmunity, cancer and even allergic disorders. Putative surrogate NET biomarkers (e.g., double-strand DNA (dsDNA), myeloperoxidase-DNA (MPO-DNA), and citrullinated histone H3 (CitH3)) have been found in different sites/fluids of patients with asthma. Targeting NETs has been proposed as a therapeutic strategy in several diseases. However, different NETs and NET components may have alternate, even opposite, consequences on inflammation. Here we review recent findings emphasizing the pathogenic and therapeutic potential of NETs in asthma.

TCR-engineered iNKT cells induce robust antitumor response by dual targeting cancer and suppressive myeloid cells

Adoptive immunotherapy with T cells engineered with tumor-specific T cell receptors (TCRs) holds promise for cancer treatment. However, suppressive cues generated in the tumor microenvironment (TME) can hinder the efficacy of these therapies, prompting the search for strategies to overcome these detrimental conditions and improve cellular therapeutic approaches. CD1d-restricted invariant natural killer T (iNKT) cells actively participate in tumor immunosurveillance by restricting suppressive myeloid populations in the TME. Here, we showed that harnessing iNKT cells with a second TCR specific for a tumor-associated peptide generated bispecific effectors for CD1d- and major histocompatibility complex (MHC)-restricted antigens in vitro. Upon in vivo transfer, TCR-engineered iNKT (TCR-iNKT) cells showed the highest efficacy in restraining the progression of multiple tumors that expressed the cognate antigen compared with nontransduced iNKT cells or CD8+ T cells engineered with the same TCR. TCR-iNKT cells achieved robust cancer control by simultaneously modulating intratumoral suppressive myeloid populations and killing malignant cells. This dual antitumor function was further enhanced when the iNKT cell agonist α-galactosyl ceramide (α-GalCer) was administered as a therapeutic booster through a platform that ensured controlled delivery at the tumor site, named multistage vector (MSV). These preclinical results support the combination of tumor-redirected TCR-iNKT cells and local α-GalCer boosting as a potential therapy for patients with cancer.

Evaluating immune response and metabolic related biomarkers pre-allogenic hematopoietic stem cell transplant in acute myeloid leukemia

Although hematopoietic stem cell transplantation (HCT) is the only curative treatment for acute myeloid leukemia (AML), it is associated with significant treatment related morbidity and mortality. There is great need for predictive biomarkers associated with overall survival (OS) and clinical outcomes. We hypothesized that circulating metabolic, inflammatory, and immune molecules have potential as predictive biomarkers for AML patients who receive HCT treatment. This retrospective study was designed with an exploratory approach to comprehensively characterize immune, inflammatory, and metabolomic biomarkers. We identified patients with AML who underwent HCT and had existing baseline plasma samples. Using those samples (n = 34), we studied 65 blood based metabolomic and 61 immune/inflammatory related biomarkers, comparing patients with either long-term OS (≥ 3 years) or short-term OS (OS ≤ 1 years). We also compared the immune/inflammatory response and metabolomic biomarkers in younger vs. older AML patients (≤30 years vs. ≥ 55 years old). In addition, the biomarker profiles were analyzed for their association with clinical outcomes, namely OS, chronic graft versus host disease (cGVHD), acute graft versus host disease (aGVHD), infection and relapse. Several baseline biomarkers were elevated in older versus younger patients, and baseline levels were lower for three markers (IL13, SAA, CRP) in patients with OS ≥ 3 years. We also identified immune/inflammatory response markers associated with aGVHD (IL-9, Eotaxin-3), cGVHD (Flt-1), infection (D-dimer), or relapse (IL-17D, bFGF, Eotaxin-3). Evaluation of metabolic markers demonstrated higher baseline levels of medium- and long-chain acylcarnitines (AC) in older patients, association with aGVHD (lactate, long-chain AC), and cGVHD (medium-chain AC). These differentially expressed profiles merit further evaluation as predictive biomarkers.

Adoptive Immunotherapy With Engineered iNKT Cells to Target Cancer Cells and the Suppressive Microenvironment

Invariant Natural Killer T (iNKT) cells are T lymphocytes expressing a conserved semi-invariant TCR specific for lipid antigens (Ags) restricted for the monomorphic MHC class I-related molecule CD1d. iNKT cells infiltrate mouse and human tumors and play an important role in the immune surveillance against solid and hematological malignancies. Because of unique functional features, they are attractive platforms for adoptive cells immunotherapy of cancer compared to conventional T cells. iNKT cells can directly kill CD1d-expressing cancer cells, but also restrict immunosuppressive myelomonocytic populations in the tumor microenvironment (TME) via CD1d-cognate recognition, promoting anti-tumor responses irrespective of the CD1d expression by cancer cells. Moreover, iNKT cells can be adoptively transferred across MHC barriers without risk of alloreaction because CD1d molecules are identical in all individuals, in addition to their ability to suppress graft vs. host disease (GvHD) without impairing the anti-tumor responses. Within this functional framework, iNKT cells are successfully engineered to acquire a second antigen-specificity by expressing recombinant TCRs or Chimeric Antigen Receptor (CAR) specific for tumor-associated antigens, enabling the direct targeting of antigen-expressing cancer cells, while maintaining their CD1d-dependent functions. These new evidences support the exploitation of iNKT cells for donor unrestricted, and possibly off the shelf, adoptive cell therapies enabling the concurrent targeting of cancer cells and suppressive microenvironment.

A Novel Machine Learning 13-Gene Signature: Improving Risk Analysis and Survival Prediction for Clear Cell Renal Cell Carcinoma Patients

Simple Summary

Clear cell renal cell carcinoma is a type of kidney cancer which comprises the majority of all renal cell carcinomas. Many efforts have been made to identify biomarkers which could help healthcare professionals better treat this kind of cancer. With extensive public data available, we conducted a machine learning study to determine a gene signature that could indicate patient survival with high accuracy. Through the min-Redundancy and Max-Relevance algorithm we generated a signature of 13 genes highly correlated with patient outcomes. These findings reveal potential strategies for personalized medicine in the clinical practice.

Abstract

Patients with clear cell renal cell carcinoma (ccRCC) have poor survival outcomes, especially if it has metastasized. It is of paramount importance to identify biomarkers in genomic data that could help predict the aggressiveness of ccRCC and its resistance to drugs. Thus, we conducted a study with the aims of evaluating gene signatures and proposing a novel one with higher predictive power and generalization in comparison to the former signatures. Using ccRCC cohorts of the Cancer Genome Atlas (TCGA-KIRC) and International Cancer Genome Consortium (ICGC-RECA), we evaluated linear survival models of Cox regression with 14 signatures and six methods of feature selection, and performed functional analysis and differential gene expression approaches. In this study, we established a 13-gene signature (AR, AL353637.1, DPP6, FOXJ1, GNB3, HHLA2, IL4, LIMCH1, LINC01732, OTX1, SAA1, SEMA3G, ZIC2) whose expression levels are able to predict distinct outcomes of patients with ccRCC. Moreover, we performed a comparison between our signature and others from the literature. The best-performing gene signature was achieved using the ensemble method Min-Redundancy and Max-Relevance (mRMR). This signature comprises unique features in comparison to the others, such as generalization through different cohorts and being functionally enriched in significant pathways: Urothelial Carcinoma, Chronic Kidney disease, and Transitional cell carcinoma, Nephrolithiasis. From the 13 genes in our signature, eight are known to be correlated with ccRCC patient survival and four are immune-related. Our model showed a performance of 0.82 using the Receiver Operator Characteristic (ROC) Area Under Curve (AUC) metric and it generalized well between the cohorts. Our findings revealed two clusters of genes with high expression (SAA1, OTX1, ZIC2, LINC01732, GNB3 and IL4) and low expression (AL353637.1, AR, HHLA2, LIMCH1, SEMA3G, DPP6, and FOXJ1) which are both correlated with poor prognosis. This signature can potentially be used in clinical practice to support patient treatment care and follow-up.

Tumor-Infiltrating PD-L1+ Neutrophils Induced by GM-CSF Suppress T Cell Function in Laryngeal Squamous Cell Carcinoma and Predict Unfavorable Prognosis

Purpose

Chronic inflammation contributes to tumor initiation, progression, and immune escape. Neutrophils are the major component of inflammatory response and participate in the tumorigenesis process. However, compared to other immune cells in the tumor microenvironment of laryngeal squamous cell carcinoma (LSCC), neutrophils, especially the tumor-associated neutrophils (TANs), have not yet been comprehensively explored. The mechanism for regulating the crosstalk between TANs and tumor cells still remains unclear.

Materials and Methods

The distribution profiles and phenotypic features of neutrophils and other inflammatory immune cell populations from a large LSCC patient cohort were systemically analyzed. Co-culturing of peripheral blood associated neutrophils (PANs) and TANs with PBMCs was performed, and the immunosuppression effect on T-cells was examined.

Results

LSCC microenvironment is highly inflammatory with remarkable TANs infiltration, which is often associated with unfavorable prognosis and advanced clinical stage. We find that TANs in LSCC display morphologically immature and lower apoptosis, exhibit distinctively immunosuppressive phenotype of high PD-L1, and suppress CD8⁺ T lymphocytes proliferation and activation. We subsequently discover that PD-L1⁺TANs induced by LSCC-derived GM-CSF potently impair CD8⁺ T-cells proliferation and cytokines production function, which are partially blocked by a PD-L1-neutralizing antibody. Clinical data further support GM-CSF as an unfavorable prognostic biomarker and reveal a potential association with inflammatory immune cell infiltration, in particular neutrophils.

Conclusion

Tumor-infiltrating PD-L1+ neutrophils induced by LSCC-derived GM-CSF suppress T cell proliferation and activation in the inflammatory microenvironment of LSCC and predict unfavorable prognosis. These TANs cripple antitumor T cell immunity and promote tumor progression. Our findings provide a basis for targeting PD-L1+TANs or GM-CSF as a new immunotherapeutic strategy for LSCC.

Identifying gene network patterns and associated cellular immune responses in children with or without nut allergy

Background

Although evidence suggests that the immune system plays a key role in the pathophysiology of nut allergy, the precise immunological mechanisms of nut allergy have not been systematically investigated. The aim of the present study was to identify gene network patterns and associated cellular immune responses in children with or without nut allergy.

Methods

Transcriptome profiling of whole blood cells was compared between children with and without nut allergy. Three genes were selected to be validated on a larger cohort of samples (n = 86) by reverse transcription-polymerase chain reactions (RT-qPCR). The composition of immune cells was inferred from the transcriptomic data using the CIBERSORTx algorithm. A co-expression network was constructed employing weighted gene co-expression network analysis (WGCNA) on the top 5000 most variable transcripts. The modules were interrogated with pathway analysis tools (InnateDB) and correlated with clinical phenotypes and cellular immune responses.

Results

Proportions of neutrophils were positively correlated and CD4⁺ T-cells and regulatory T-cells (Tregs) were negatively correlated with modules of nut allergy. We also identified 2 upregulated genes, namely Interferon Induced With Helicase C Domain 1 (IFIH1), DNA damage-regulated autophagy modulator 1 (DRAM1) and a downregulated gene Zinc Finger Protein 512B (ZNF512B) as hub genes for nut allergy. Further pathway analysis showed enrichment of type 1 interferon signalling in nut allergy.

Conclusions

Our findings suggest that upregulation of type 1 interferon signalling and neutrophil responses and downregulation of CD4⁺ T-cells and Tregs are features of the pathogenesis of nut allergy.

SAA induces suppressive neutrophils via the TLR2-mediated signaling pathway to promote progression of breast cancer

Immune inflammation plays a key role in breast cancer development, progression, and therapeutic efficacy. Neutrophils are crucial for the regulation of the suppressive tumor microenvironment and are associated with poor clinical survival. However, the mechanisms underlying the activation of suppressive neutrophils in breast cancer are poorly understood. Here, we report that breast cancer cells secrete abundant serum amyloid A 1 (SAA1), which is associated with the accumulation of suppressive neutrophils. High expression of SAA1 in breast cancer induces neutrophil immunosuppressive cytokine production through the activation of toll like receptor 2 (TLR2)-mediated signaling pathways. These include the TLR2/myeloid differentiation primary response 88 (MYD88)-mediated phosphatidylinositol 3-kinase (PI3K)/nuclear factor κB (NF-κB) signaling pathway and p38 mitogen-activated protein kinase (MAPK)-associated apoptosis resistance pathway, which eventually promote the progression of breast cancer. Our study demonstrates a mechanistic link between breast cancer cell secretion of SAA1 and suppressive neutrophils that potentiate tumor progression. These findings provide potential therapeutic targets for breast cancer.

Innate Immunity and Cancer Pathophysiology

Chronic inflammation increases the risk of several cancers, including gastric, colon, and hepatic cancers. Conversely, tumors, similar to tissue injury, trigger an inflammatory response coordinated by the innate immune system. Cellular and molecular mediators of inflammation modulate tumor growth directly and by influencing the adaptive immune response. Depending on the balance of immune cell types and signals within the tumor microenvironment, inflammation can support or restrain the tumor. Adding to the complexity, research from the past two decades has revealed that innate immune cells are highly heterogeneous and plastic, with variable phenotypes depending on tumor type, stage, and treatment. The field is now on the cusp of being able to harness this wealth of data to (a) classify tumors on the basis of their immune makeup, with implications for prognosis, treatment choice, and clinical outcome, and (b) design therapeutic strategies that activate antitumor immune responses by targeting innate immune cells.

Hyperinflammatory environment drives dysfunctional myeloid cell effector response to bacterial challenge in COVID-19

COVID-19 displays diverse disease severities and symptoms including acute systemic inflammation and hypercytokinemia, with subsequent dysregulation of immune cells. Bacterial superinfections in COVID-19 can further complicate the disease course and are associated with increased mortality. However, there is limited understanding of how SARS-CoV-2 pathogenesis and hypercytokinemia impede the innate immune function against bacterial superinfections. We assessed the influence of COVID-19 plasma hypercytokinemia on the functional responses of myeloid immune cells upon bacterial challenges from acute-phase COVID-19 patients and their corresponding recovery-phase. We show that a severe hypercytokinemia status in COVID-19 patients correlates with the development of bacterial superinfections. Neutrophils and monocytes derived from COVID-19 patients in their acute-phase showed an impaired intracellular microbicidal capacity upon bacterial challenges. The impaired microbicidal capacity was reflected by abrogated MPO and reduced NETs production in neutrophils along with reduced ROS production in both neutrophils and monocytes. Moreover, we observed a distinct pattern of cell surface receptor expression on both neutrophils and monocytes, in line with suppressed autocrine and paracrine cytokine signaling. This phenotype was characterized by a high expression of CD66b, CXCR4 and low expression of CXCR1, CXCR2 and CD15 in neutrophils and low expression of HLA-DR, CD86 and high expression of CD163 and CD11b in monocytes. Furthermore, the impaired antibacterial effector function was mediated by synergistic effect of the cytokines TNF-α, IFN-γ and IL-4. COVID-19 patients receiving dexamethasone showed a significant reduction of overall inflammatory markers in the plasma as well as exhibited an enhanced immune response towards bacterial challenge ex vivo. Finally, broad anti-inflammatory treatment was associated with a reduction in CRP, IL-6 levels as well as length of ICU stay and ventilation-days in critically ill COVID-19 patients. Our data provides insights into the transient functional dysregulation of myeloid immune cells against subsequent bacterial infections in COVID-19 patients and describe a beneficial role for the use of dexamethasone in these patients.

Neutrophil Expression of T and B Immunomodulatory Molecules in HIV Infection

Objective

Evaluate the expression of B and T cell immunomodulatory molecules in polymorphonuclear neutrophils (PMN) in HIV-infected patients.

Methods

HIV load, bacterial translocation and neutrophils’ expression of T [programmed death ligand, interleukin-10+, arginase 1+] and B [BAFF, APRIL] molecules were analyzed in different cohorts and time points: a control group of 25 healthy individuals and two groups of HIV-infected patients. Group 1 of patients included 35 untreated patients, studied at baseline and after antiretroviral therapy (ART). Group 2 was composed of 25 patients with undetectable viral load after a median of 101 months of ART prior to inclusion in the study.

Results

Compared with the control group, group 1 patients showed increased bacterial translocation and their PMN had a significantly higher expression of T and B-cell immunomodulatory molecules, both at baseline and after 12 months of ART. Group 2 patients showed reduced bacterial translocation levels when compared with group 1 patients after 12 months of treatment. PMN expression of B-cell modulators was similar between group 2 patients and healthy controls, although the expression of T-cell modulators remained increased.

Conclusion

In HIV-infected patients, the expression of B-cell stimulatory and T-cell suppressive molecules by neutrophils was increased at baseline and after a limited time of therapy. After a prolonged period of ART, only PMNs expression of T-cell immunosuppressive molecules remained elevated.

Development of Stem Cell-Derived Immune Cells for Off-the-Shelf Cancer Immunotherapies

Cell-based cancer immunotherapy has revolutionized the treatment of hematological malignancies. Specifically, autologous chimeric antigen receptor-engineered T (CAR-T) cell therapies have received approvals for treating leukemias, lymphomas, and multiple myeloma following unprecedented clinical response rates. A critical barrier to the widespread usage of current CAR-T cell products is their autologous nature, which renders these cellular products patient-selective, costly, and challenging to manufacture. Allogeneic cell products can be scalable and readily administrable but face critical concerns of graft-versus-host disease (GvHD), a life-threatening adverse event in which therapeutic cells attack host tissues, and allorejection, in which host immune cells eliminate therapeutic cells, thereby limiting their antitumor efficacy. In this review, we discuss recent advances in developing stem cell-engineered allogeneic cell therapies that aim to overcome the limitations of current autologous and allogeneic cell therapies, with a special focus on stem cell-engineered conventional αβ T cells, unconventional T (iNKT, MAIT, and γδ T) cells, and natural killer (NK) cells.

Dichotomous roles of neutrophils in modulating pathogenic and repair processes of inflammatory bowel diseases

Neutrophils are considered as complex innate immune cells and play a critical role in maintaining intestinal mucosal homeostasis. They exert robust pro-inflammatory effects and recruit other immune cells in the acute phase of pathogen infection and intestinal inflammation, but paradoxically, they also limit exogenous microbial invasion and facilitate mucosal restoration. Hyperactivation or dysfunction of neutrophils results in abnormal immune responses, leading to multiple autoimmune and inflammatory diseases including systemic lupus erythematosus, rheumatoid arthritis, and inflammatory bowel diseases (IBD). As a refractory intestinal inflammatory disease, the pathogenesis and progression of IBD are associated with complicated immune response processes in which neutrophils are profoundly involved. However, the consensus on potential roles of neutrophils in modulating pathogenic and repair processes of IBD remains not fully understood. Accumulated infiltrating neutrophils cross the epithelial barrier and contribute to microbial dysbiosis, aggravated intestinal architectural damage, compromised resolution of intestinal inflammation and increased risk of thrombosis during IBD. Paradoxically, activated neutrophils are also associated with effective elimination of invaded microbiota, promoted angiogenesis and tissue restoration of gut mucosa in IBD. Here, we discuss the beneficial and detrimental roles of neutrophils in the onset and resolution of intestinal mucosal inflammation, hoping to provide a precise overview of neutrophil functions in the pathogenesis of IBD.

Neuroinflammation Mediates Faster Brachial Plexus Regeneration in Subjects with Cerebral Injury

Our previous investigation suggested that faster seventh cervical nerve (C7) regeneration occurs in patients with cerebral injury undergoing contralateral C7 transfer. This finding needed further verification, and the mechanism remained largely unknown. Here, Tinel's test revealed faster C7 regeneration in patients with cerebral injury, which was further confirmed in mice by electrophysiological recordings and histological analysis. Furthermore, we identified an altered systemic inflammatory response that led to the transformation of macrophage polarization as a mechanism underlying the increased nerve regeneration in patients with cerebral injury. In mice, we showed that, as a contributing factor, serum amyloid protein A1 (SAA1) promoted C7 regeneration and interfered with macrophage polarization in vivo. Our results indicate that altered inflammation promotes the regenerative capacity of the C7 nerve by altering macrophage behavior. SAA1 may be a therapeutic target to improve the recovery of injured peripheral nerves.

Chimeric antigen receptor- and natural killer cell receptor-engineered innate killer cells in cancer immunotherapy

Chimeric antigen receptor (CAR)-engineered T-cell (CAR-T) therapy has demonstrated impressive therapeutic efficacy against hematological malignancies, but multiple challenges have hindered its application, particularly for the eradication of solid tumors. Innate killer cells (IKCs), particularly NK cells, NKT cells, and γδ T cells, employ specific antigen-independent innate tumor recognition and cytotoxic mechanisms that simultaneously display high antitumor efficacy and prevent tumor escape caused by antigen loss or modulation. IKCs are associated with a low risk of developing GVHD, thus offering new opportunities for allogeneic "off-the-shelf" cellular therapeutic products. The unique innate features, wide tumor recognition range, and potent antitumor functions of IKCs make them potentially excellent candidates for cancer immunotherapy, particularly serving as platforms for CAR development. In this review, we first provide a brief summary of the challenges hampering CAR-T-cell therapy applications and then discuss the latest CAR-NK-cell research, covering the advantages, applications, and clinical translation of CAR- and NK-cell receptor (NKR)-engineered IKCs. Advances in synthetic biology and the development of novel genetic engineering techniques, such as gene-editing and cellular reprogramming, will enable the further optimization of IKC-based anticancer therapies.

Transcriptomics of biopsies identifies novel genes and pathways linked to neutrophilic inflammation in severe asthma

BACKGROUND

Severe asthma is a complex disease. Transcriptomic profiling has contributed to understanding the pathogenesis of asthma, especially type-2 inflammation. However, there is still poor understanding of non-type-2 asthma, and consequently, there are limited treatment options.

OBJECTIVE

The aim of this study was to identify differentially expressed genes (DEGs) and pathways in endobronchial biopsies associated with inflammatory phenotypes of severe asthma.

METHODS

This cross-sectional study examined endobronchial biopsies from 47 adults with severe asthma (neutrophilic asthma (NA) n = 9, eosinophilic asthma (EA) n = 22 and paucigranulocytic asthma (PGA) n = 16) and 13 healthy controls (HC). RNA was extracted and transcriptomic profiles generated (Illumina Humanref-12 V4) and analysed using GeneSpring GX14.9.1. Pathway identification using Ingenuity Pathway Analysis.

RESULTS

NA had the most distinct profile, with signature of 60 top-ranked DEGs (FC >±2) including genes associated with innate immunity response, neutrophil degranulation and IL-10 signalling. NA presented enrichment to pathways previously linked to neutrophilic inflammation; dendritic cell maturation, Th1, TREM1, inflammasome, Th17 and p38 MAPK, as well as novel links to neuroinflammation, NFAT and PKCθ signalling. EA presented similar transcriptomic profiles to PGA and HC. Despite the higher proportion of bacterial colonization in NA, no changes were observed in the transcriptomic profiles of severe asthma culture positive compared with severe asthma culture negative.

CONCLUSIONS & CLINICAL RELEVANCE

NA features a distinct transcriptomic profile with seven pathways enriched in NA compared to EA, PGA and HC. All those with severe asthma had significant enrichment for SUMOylation, basal cell carcinoma signalling and Wnt/β-catenin pathways compared to HC, despite high-dose inhaled corticosteroids. These findings contribute to the understanding of mechanistic pathways in endobronchial biopsies associated with NA and identify potential novel treatment targets for severe asthma.

The Role of NKT Cells in Glioblastoma

Glioblastoma is an aggressive and deadly cancer, but to date, immunotherapies have failed to make significant strides in improving prognoses for glioblastoma patients. One of the current challenges to developing immunological interventions for glioblastoma is our incomplete understanding of the numerous immunoregulatory mechanisms at play in the glioblastoma tumor microenvironment. We propose that Natural Killer T (NKT) cells, which are unconventional T lymphocytes that recognize lipid antigens presented by CD1d molecules, may play a key immunoregulatory role in glioblastoma. For example, evidence suggests that the activation of type I NKT cells can facilitate anti-glioblastoma immune responses. On the other hand, type II NKT cells are known to play an immunosuppressive role in other cancers, as well as to cross-regulate type I NKT cell activity, although their specific role in glioblastoma remains largely unclear. This review provides a summary of our current understanding of NKT cells in the immunoregulation of glioblastoma as well as highlights the involvement of NKT cells in other cancers and central nervous system diseases.

Aspirin-Triggered Resolvin D1 Reduces Proliferation and the Neutrophil to Lymphocyte Ratio in a Mutant KRAS-Driven Lung Adenocarcinoma Model

Simple Summary

Aspirin-triggered resolvin D1 (AT-RvD1) is biosynthesised by leukocytes as a mechanism to resolve inflammation during infection and/or injury. Emerging studies reveal that AT-RvD1 also has anti-cancer properties associated with stimulating macrophage-mediated clearance of tumour debris. No study to date has investigated how AT-RvD1 influences the neutrophil to lymphocyte ratio (NLR) in lung cancer, an established marker of poor prognosis. The biosynthesis of AT-RvD1 is dependent on the ALOX5 gene, and we reveal that ALOX5 mRNA expression was markedly reduced in lung adenocarcinoma tumours. We next utilised an oncogenic Kras^G12D lung adenocarcinoma mouse model to investigate the efficacy of AT-RvD1 in vivo. We show for the first time that AT-RvD1 reduces tumour growth in the lungs of Kras^G12D mice and alters the immune landscape in tumours by reducing the NLR.

Abstract

Tumour-associated neutrophils (TANs) can support tumour growth by suppressing cytotoxic lymphocytes. AT-RvD1 is an eicosanoid that can antagonise neutrophil trafficking instigated by ALX/FPR2 ligands such as serum amyloid A (SAA). We aimed to establish whether SAA and ALOX5 expression associates with TANs and investigate the immunomodulatory actions of AT-RvD1 in vivo. MPO-positive neutrophils were quantified in tumour blocks from lung adenocarcinoma (n = 48) and control tissue (n = 20) by IHC. Tumour expression of SAA and ALOX5 were analysed by RTqPCR and an oncogenic Kras^G12D lung adenocarcinoma mouse model was used to investigate the in vivo efficacy of AT-RvD1 treatment. ALOX5 expression was markedly reduced in lung adenocarcinoma tumours. The SAA/ALOX5 ratio strongly correlated with TANs and was significantly increased in tumours harbouring an oncogenic KRAS mutation. AT-RvD1 treatment reduced tumour growth in Kras^G12D mice, which was accompanied by suppressed cellular proliferation within parenchymal lesions. In addition, AT-RvD1 significantly reduced the neutrophil to lymphocyte ratio (NLR), an established prognostic marker of poor survival in adenocarcinoma. This study identifies a novel molecular signature whereby elevated levels of SAA relative to ALOX5 favour accumulation of TANs. Furthermore, the ALOX5/5-LO enzymatic product, AT-RvD1, markedly reduced the NLR and suppressed tumour growth in Kras^G12D mice.

Serum Amyloid A Proteins and Their Impact on Metastasis and Immune Biology in Cancer

Simple Summary

The liver responds to systemic inflammation and injury in a coordinated manner, called the acute phase response. While this normal physiological response aims to restore homeostasis, malignant transformation coopts this biology to increase the risk for metastasis, immune evasion, and therapeutic resistance. In this Review, we discuss the importance of acute phase response proteins in regulating cancer biology and treatment efficacy. We also consider potential strategies to intervene on acute phase biology as an approach to improve outcomes in cancer.

Abstract

Cancer triggers the systemic release of inflammatory molecules that support cancer cell metastasis and immune evasion. Notably, this biology shows striking similarity to an acute phase response that is coordinated by the liver. Consistent with this, a role for the liver in defining cancer biology is becoming increasingly appreciated. Understanding the mechanisms that link acute phase biology to metastasis and immune evasion in cancer may reveal vulnerable pathways and novel therapeutic targets. Herein, we discuss a link between acute phase biology and cancer with a focus on serum amyloid A proteins and their involvement in regulating the metastatic cascade and cancer immunobiology.

B-Helper Neutrophils in Regional Lymph Nodes Correlate with Improved Prognosis in Patients with Head and Neck Cancer

Simple Summary

Neutrophils exhibit multiple functions during cancer progression and are believed to regulate adaptive immune responses to cancer. In addition to their interactions with T cells in this context, these cells are also believed to interact with B cells. Neutrophils have been found in the marginal zone of the spleen, where they exhibit helper cell characteristics, supporting B cell proliferation and activation. Here, we investigate the effect of neutrophils on B cells in the regional lymph nodes (RLN) of head-and-neck cancer (HNC) patients. We have identified that, in RLNs, neutrophils express a helper cell phenotype that was associated with the increased activation and proliferation of B cells. Importantly, the high abundance of neutrophils in the B cell follicles of regional lymph nodes is associated with significantly improved HNC patient survival.

Abstract

The role of neutrophils during cancer formation and elimination is diverse. Here, for the first time, we investigate neutrophil helper cells (N_BH), their influence on B cell activity in the regional lymph nodes (RLN) of head-and-neck cancer patients and the effect of this neutrophil/B cell interaction on patient prognosis. Circulating and RLN neutrophils of patients with stage I–IV head-and-neck squamous cell carcinoma were investigated with flow cytometry and qPCR. In addition, neutrophil/B cell co-localization in RLNs was evaluated using immunohistochemistry. B cell proliferation was assessed and correlated with the distance to neutrophils. Patient survival was evaluated. Neutrophils with the helper cell phenotype were identified in the RLN of HNC patients. B cells in close proximity to such N_BH showed significantly higher proliferation rates, together with elevated activation-induced cytidine deaminase (AID) expression. Notably, patient survival was significantly higher in individuals with high N_BH frequencies in the B follicles of RLNs. Neutrophils in RLN can support T cell-independent activation of the adaptive immune system through B cell stimulation, capturing helper cell phenotype character. The presence of such helper neutrophils in the RLNs of HNC patients positively correlates with patient prognosis.

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.

Baseline and early changes in circulating Serum Amyloid A (SAA) predict survival outcomes in advanced non-small cell lung cancer patients treated with Anti-PD-1/PD-L1 monotherapy

BACKGROUND

Systemic inflammation plays an important role in carcinogenesis and is associated with overall survival in patients with different cancer types, including those treated with immune checkpoint blockade (ICB). Serum Amyloid A (SAA) is an acute-phase protein and a marker of persistent inflammation. We hypothesized that circulating SAA may predict outcomes in advanced non-small cell lung (aNSCLC) patients treated with PD-1/PD-L1 ICB.

MATERIALS AND METHODS

This retrospective study included 91 aNSCLC patients who received anti-PD-(L)1 monotherapy in Sun Yat-sen University Cancer Center (Guangzhou, China) between August 2016 and June 2018. We examined the impact of circulating SAA at baseline and 8 (±2) weeks later on overall survival (OS). X-tile program was used to determine the cut-off values which optimized the significance of the split between Kaplan-Meier survival curves. Kaplan-Meier methodology and Cox regression analyses were conducted for survival analyses.

RESULTS

The optimal cut-off value of baseline SAA for OS stratification was 137.6 mg/L. In univariate analysis, both high level of baseline SAA (hazard ratio [HR], 2.76; 95% confidence interval [CI], 1.47-5.18; P = 0.002) and lack of early SAA descent (HR, 1.51; 95% CI, 1.11-2.06; P = 0.009) were significantly associated with inferior OS. In multivariate analysis, gender, smoking status, performance status, liver metastasis, neutrophil-to-lymphocyte ratio, baseline SAA and early changes in SAA independently predicted OS (all with P < 0.05). A combined baseline SAA ≥ 137.6 mg/L and without early SAA descent identified a small cohort with remarkably worse OS (median, 3.2 months).

CONCLUSIONS

Both high baseline and lack of early decline in circulating SAA are significantly associated with inferior outcomes in aNSCLC patients treated with PD-1/PD-L1 ICB. Combined these two SAA indexes provided improved risk stratification. The prognostic value of this simple, readily-available, and cost-effective biomarker warrants larger, prospective validation before definitive recommendation can be made.

Aerosol inhalation of ambroxol hydrochloride combined with terbutaline can promote recovery of children with severe pneumonia

OBJECTIVE

This research aimed to investigate the clinical efficacy of aerosol inhalation of ambroxol hydrochloride combined with terbutaline on children with severe pneumonia, and to evaluate its influence on their immune function and inflammatory level.

METHODS

Totally 113 severe pneumonia children were included. Thereinto, 55 children in the control group (CG) were treated with terbutaline aerosol inhalation, while 58 in the research group (RG) were given ambroxol hydrochloride on the basis of the CG. Their symptom alleviating time, blood gas parameters, adverse reactions during treatment, clinical efficacy, immune function and inflammatory factors were compared.

RESULTS

The time of fever clearance time, disappearance of cough and pulmonary rates, chest shadow absorption and hospitalization of children in the RG were shorter than those in the CG. The combined treatment did not increase additional adverse reactions; instead, its effective rate was markedly higher than that in the CG. Further research found that after treatment, the arterial partial pressure of oxygen (PaO2), oxygenation index (OI), CD4+ and CD4+/CD8+, and interleukin-10 (IL-10) levels were dramatically increased, while the arterial partial pressure of carbon dioxide (PaCO2), C-reactive protein (CRP), interleukin-6 (IL-6), interleukin-17 (IL-17) and CD8+ levels were obviously increased. In addition, these indexes of children in the RG were obviously better than those in the CG.

CONCLUSION

Aerosol inhalation of ambroxol hydrochloride combined with terbutaline has a remarkable clinical efficacy on children with severe pneumonia, which can improve their immune function and reduce inflammatory reaction.

IFN-γ-dependent NK cell activation is essential to metastasis suppression by engineered Salmonella

Metastasis accounts for 90% of cancer-related deaths and, currently, there are no effective clinical therapies to block the metastatic cascade. A need to develop novel therapies specifically targeting fundamental metastasis processes remains urgent. Here, we demonstrate that Salmonella YB1, an engineered oxygen-sensitive strain, potently inhibits metastasis of a broad range of cancers. This process requires both IFN-γ and NK cells, as the absence of IFN-γ greatly reduces, whilst depletion of NK cells in vivo completely abolishes, the anti-metastatic ability of Salmonella. Mechanistically, we find that IFN-γ is mainly produced by NK cells during early Salmonella infection, and in turn, IFN-γ promotes the accumulation, activation, and cytotoxicity of NK cells, which kill the metastatic cancer cells thus achieving an anti-metastatic effect. Our findings highlight the significance of a self-regulatory feedback loop of NK cells in inhibiting metastasis, pointing a possible approach to develop anti-metastatic therapies by harnessing the power of NK cells.

Phagocytosis, Degranulation and Extracellular Traps Release by Neutrophils-The Current Knowledge, Pharmacological Modulation and Future Prospects

Neutrophils are crucial elements of innate immune system, which assure host defense via a range of effector functions, such as phagocytosis, degranulation, and NET formation. The latest literature clearly indicates that modulation of effector functions of neutrophils may affect the treatment efficacy. Pharmacological modulation may affect molecular mechanisms activating or suppressing phagocytosis, degranulation or NET formation. In this review, we describe the role of neutrophils in physiology and in the course of bacterial and viral infections, illustrating the versatility and plasticity of those cells. This review also focus on the action of plant extracts, plant-derived compounds and synthetic drugs on effector functions of neutrophils. These recent advances in the knowledge can help to devise novel therapeutic approaches via pharmacological modulation of the described processes.

Inflammation and Apolipoproteins Are Potential Biomarkers for Stratification of Cutaneous Melanoma Patients for Immunotherapy and Targeted Therapy

Malignant cutaneous melanoma is one of the most common cancers in young adults. During the last decade, targeted and immunotherapies have significantly increased the overall survival of patients with malignant cutaneous melanoma. Nevertheless, disease progression is common, and a lack of predictive biomarkers of patient response to therapy hinders individualized treatment strategies. To address this issue, we performed a longitudinal study using an unbiased proteomics approach to identify and quantify proteins in plasma both before and during treatment from 109 patients treated with either targeted or immunotherapy. Linear modeling and machine learning approaches identified 43 potential prognostic and predictive biomarkers. A reverse correlation between apolipoproteins and proteins related to inflammation was observed. In the immunotherapy group, patients with low pretreatment expression of apolipoproteins and high expression of inflammation markers had shorter progression-free survival. Similarly, increased expression of LDHB during treatment elicited a significant impact on response to immunotherapy. Overall, we identified potential common and treatment-specific biomarkers in malignant cutaneous melanoma, paving the way for clinical use of these biomarkers following validation on a larger cohort. SIGNIFICANCE: This study identifies a potential biomarker panel that could improve the selection of therapy for patients with cutaneous melanoma.