NK cell-based cancer immunotherapy: from basic biology to clinical development

A chimeric antigen receptor tailored to integrate complementary activation signals potentiates the antitumor activity of NK cells

BACKGROUND

Chimeric antigen receptors (CARs) are synthetic receptors that reprogram the target specificity and functions of CAR-expressing effector cells. The design of CAR constructs typically includes an extracellular antigen-binding moiety, hinge (H), transmembrane (TM), and intracellular signaling domains. Conventional CAR constructs are primarily designed for T cells but have been directly adopted for other effector cells, including natural killer (NK) cells, without tailored optimization. Given the benefits of CAR-NK cells over CAR-T cells in terms of safety, off-the-shelf utility, and antigen escape, there is an increasing emphasis on tailoring them to NK cell activation mechanisms.

METHODS

We first have taken a stepwise approach to modifying CAR components such as the combination and order of the H, TM, and signaling domains to achieve such tailoring in NK cells. Functionality of NK-tailored CARs were evaluated in vitro and in vivo in a model of CD19-expressing lymphoma, along with their expression and signaling properties in NK cells.

RESULTS

We found that NK-CAR driven by the synergistic combination of NK receptors NKG2D and 2B4 rather than DNAM-1 and 2B4 induces potent activation in NK cells. Further, more effective CAR-mediated cytotoxicity was observed following the sequential combination of DAP10, but not NKG2D TM, with 2B4 signaling domain despite the capacity of NKG2D TM to recruit endogenous DAP10 for signaling. Accordingly, an NK-CAR incorporating DAP10, 2B4, and CD3ζ signaling domains coupled to CD8α H and CD28 TM domains was identified as the most promising candidate to improve CAR-mediated cytotoxicity. This NK-tailored CAR provided more potent antitumor activity than a conventional T-CAR when delivered to NK cells both in vitro and in vivo.

CONCLUSIONS

Hence, NK receptor-based domains hold great promise for the future of NK-CAR design with potentially significant therapeutic benefits.

Boosting tumor homing of endogenous natural killer cells via therapeutic secretomes of chemically primed natural killer cells

BACKGROUND

Natural killer (NK) cells play a critical role in modulating immune responses by secreting soluble factors, including chemotactic cytokines. Our previous study demonstrated the potent antitumor activity of Chem_NK, referring to NK cells chemically primed with 25 kDa branched polyethyleneimine. However, the potential of Chem_NK secretomes to educate other NK cells and enhance their tumor-homing ability remains unexplored.

METHODS

The effects of Chem_NK conditioned media (Chem CM) on NK cells were evaluated in vitro by examining chemokine receptor expression and migration toward cancer cells. In vivo, the impact of Chem_NK and Chem CM on endogenous NK cell populations was assessed using xenograft and syngeneic mouse tumor models. Cytokine array and signaling analyses were performed to identify factors secreted by Chem_NK and their role in activating recipient NK cells.

RESULTS

Chem CM effectively educated NK cells in vitro, enhancing chemokine receptor expression and improving their migration toward cancer cells. In vivo, adoptively transferred Chem_NK increased endogenous NK cell populations within xenograft tumors. Furthermore, direct injection of Chem CM into a syngeneic mouse tumor model significantly promoted endogenous NK cell infiltration into tumors and suppressed lung metastasis. Cytokine analysis revealed that Chem_NK secreted high levels of cytokines, which activated ERK1/2 signaling in recipient NK cells, leading to upregulation of chemokine receptors.

CONCLUSIONS

Chem_NK secretomes effectively enhance the tumor-homing ability of NK cells and amplify antitumor efficacy by educating other NK cells. These findings offer novel insights into activated NK cell-mediated immune communication and highlight the therapeutic potential of NK cell-derived secretomes in cancer therapy.

CD63 as a potential biomarker for patients with ovarian cancer

INTRODUCTION

Exosomes play an important role in regulating physiological processes and mediating the systemic dissemination of various types of cancer. We investigated the association of exosomal tetraspanins CD9, CD63, and CD81 in patients with ovarian cancer (OC).

MATERIAL AND METHODS

We measured the plasma tetraspanins CD9, CD63, and CD81 by enzyme-linked immunosorbent assay in 91 patients who underwent treatment for OC between April 2018 and March 2024. Additionally, we analyzed clinical pathologic factors, chemotherapy response, and prognosis.

RESULTS

In terms of stages, CD63 expression was significantly higher in patients with stage IV compared to those with stage I OC (p = 0.003). In terms of histological type, CD63 expression was significantly higher in high-grade serous carcinoma (HGSC) than in clear cell carcinoma (CCC) with OC (p = 0.009). Furthermore, CD63 levels were significantly higher in advanced-stage, HGSC than in patients with early-stage, non-HGSC and early-stage, HGSC OC (p = 0.045 and p = 0.002, respectively). In the Neoadjuvant chemotherapy (NAC) of 12 patients with OC assessed as having either a partial response (PR) or complete response (CR), CD63 was significantly decreased (p = 0.043), whereas perforin was significantly increased (p = 0.001). In the NAC of 16 patients with OC, CD63 of the response rate to chemotherapy tended to differ between the progressive disease (PD) and PR/CR groups (p = 0.056). A moderate inverse correlation was observed between CD63 and perforin levels (R = 0.638, R2 = 0.428, p = 0.008).

CONCLUSIONS

CD63 could be a potential biomarker for all types of OC patients.

Identify key genes and biological processes participated in obesity-related cancer based on studying 12 cancers

Obesity significantly increases the risk of various diseases, particularly cancers, which present a serious threat to public health. Therefore, identifying cancers related to obesity and exploring their pathological pathways and key genes are highly significant for the prevention and treatment of these cancers. In this study, we propose the obesity and cancer edge connectivity based on expanded modular disease genes and expanded modular networks (OCEC_eDMN) algorithm, which based on the disease-related genes, Biological Process (BP) genes, and Protein-Potein Interaction (PPI) network. The algorithm utilizes Random Walk with Restart (RWR) to expand BP genes and disease genes to generate the expanded modular networks (eMNs) and disease genes (eMDs). Finally, this algorithm calculates the average interaction number between eMDs on eMNs. We utilize OCEC_eDMN to predict the ranking of 12 cancers related to obesity/morbid obesity and obtain an AUC of 0.93/0.84. Additionally, OCEC_eDMN reveals the significant BPs associated with obesity-cancer connections. For instance, "gluconeogenesis" plays a critical role in the connections between obesity and cancers. Through key driver analysis (KDA) on eMDs, we identify the key connectors in obesity-cancer connections. Genes such as GRB2 are instrumental in linking morbid obesity to colorectal cancer in the eMNs of "response to molecule of bacterial origin". The significant eMNs and key genes provide valuable references for the prevention and treatment of obesity-related cancers and carry important theoretical implications.

Immune Cell Engagers: Advancing Precision Immunotherapy for Cancer Treatment

Immune cell engagers (ICEs) are an emerging class of immunotherapies designed to harness the immune system's anti-tumor potential through precise targeting and activation of immune effector cells. By engaging T cells, natural killer (NK) cells, and phagocytes, ICEs overcome challenges such as immune evasion and MHC downregulation, addressing critical barriers in cancer treatment. T-cell engagers (TCEs), led by bispecific T-cell engagers (BiTEs), dominate the field, with innovations such as half-life-extended BiTEs, trispecific antibodies, and checkpoint inhibitory T-cell engagers driving their application in hematologic and solid malignancies. NK cell engagers (NKCEs) and phagocyte cell engagers (PCEs) are rapidly progressing, drawing on NK cells' innate cytotoxicity and macrophages' phagocytic abilities to target tumors, particularly in immunosuppressive microenvironments. Since the FDA approval of Blinatumomab in 2014, ICEs have transformed the oncology landscape, with nine FDA-approved products and numerous candidates in clinical trials. Despite challenges such as toxicity, resistance, and limited efficacy in solid tumors, ongoing research into advanced platforms and combination therapies highlights the growing potential of ICEs to provide personalized, scalable, and effective cancer treatments. This review investigates the mechanisms, platforms, research trends, and clinical progress of ICEs, emphasizing their pivotal role in advancing precision immunotherapy and their promise as a cornerstone of next-generation cancer therapies.

Amphiphilic Polyaspartamide Derivatives with Cholesterol Introduction Enhanced Ex Vivo mRNA Transfection Efficiency to Natural Killer Cells

Engineered natural killer (NK) cells eliminate cancer cells by overexpressing a chimeric antigen receptor, producing highly efficient and safe NK cell therapies. This study investigated the polyplex formulation for the fusion protein GreenLantern-natural killer group 2D (NKG2D) mRNA to evaluate its ex vivo delivery efficacy into NK cells, wherein NKG2D on the surface of NK cells recognized its counterpart NKG2D ligands on cancer cells. Amphiphilic polyaspartamide derivatives Chol-PAsp(DET/CHE) were prepared by adding cyclohexylethylamine (CHE) and diethylenetriamine (DET) in the side chains and cholesterol (Chol) at the α-terminus to enhance endosomal escapability and optimize hydrophobicity. Chol-PAsp(DET/CHE) significantly improved mRNA delivery efficacy into NK-92mi cells, explained by increased polyplex stability and improved cellular uptake of mRNA. The NKG2D-overexpressing NK-92mi cells exhibited high anticancer efficacy against human colon cancer cells without affecting the viability of fibroblasts. Therefore, Chol-PAsp(DET/CHE) could be a promising mRNA delivery carrier for the ex vivo engineering of NK cells.

Targeted therapy and immunotherapy for gastric cancer: rational strategies, novel advancements, challenges, and future perspectives

Gastric cancer (GC) is one of the most common malignant tumors worldwide, and its treatment has been a focus of medical research. Herein we systematically review the current status of and advancements in targeted therapy and immunotherapy for GC, which have emerged as important treatment strategies in recent years with great potential, and summarize the efficacy and safety of such treatments. Targeted therapies against key targets in GC, including epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), and vascular endothelial growth factor (VEGF)/VEGF receptor (VEGFR), have shown remarkable therapeutic efficacies by inhibiting tumor progression and/or blood supply. In particular, markable breakthroughs have been made in HER2-targeting drugs for HER2-positive GC patients. To address intrinsic and acquired resistances to HER2-targeting drugs, novel therapeutic agents including bispecific antibodies and antibody-drug conjugates (ADC) targeting HER2 have been developed. Immunotherapy enhances the recognition and elimination of cancer cells by activating body anticancer immune system. Programmed cell death protein 1 (PD-1) and programmed cell death-ligand 1 (PD-L1) antibodies are the most commonly used immunotherapeutic agents and have been used with some success in GC treatment. Innovative immunotherapy modalities, including adoptive immune cell therapy, tumor vaccines, and non-specific immunomodulators therapy, and oncolytic viruses have shown promise in early-stage clinical trials for GC. Clinical trials have supported that targeted therapy and immunotherapy can significantly improve the survival and quality of life of GC patients. However, the effects of such therapies need to be further improved and more personalized, with advancement in researches on tumor immune microenvironment. Further studies remain needed to address the issues of drug resistance and adverse events pertaining to such therapies for GC. The combined application of such therapies and individualized treatment strategies should be further explored with novel drugs developed, to provide more effective treatments for GC patients.

Chimeric cytokine receptor TGF-β RⅡ/IL-21R improves CAR-NK cell function by reversing the immunosuppressive tumor microenvironment of gastric cancer

Gastric cancer remains a significant global health burden, characterized by regional variations in incidence and poor survival prospects in advanced stages. Natural killer (NK) cells play a crucial role in the body's anti-cancer defense, and chimeric antigen receptor (CAR)-NK cell therapy is gaining attention as a cutting-edge and promising treatment method. This study aims to tackle the challenge of TGF-β-mediated tumor immune evasion within the immunosuppressive tumor microenvironment by designing a novel chimeric cytokine receptor TRII/21 R, which consists of extracellular domains of TGF-β receptor II (TRII) and transmembrane and intracellular domains of IL-21 receptor (21 R) and can convert the immunosuppressive signal from TGF-β in the tumor microenvironment (TME) into an NK cell activation signal through the IL-21R-STAT3 pathway. We successfully constructed NKG2D-CAR-NK cells expressing TRII/21 R and demonstrated strong anti-tumor activity against cancer cells both in vitro and in vivo. The co-expression of TRII/21 R in CAR-NK cells enhanced the cytotoxicity, promoted proliferation and survival capabilities, and reduced the expression of exhaustion markers. In the xenograft mouse model, TRII/21R-CAR-NK cells significantly inhibited tumor growth and improved the survival rate of tumor-bearing mice compared to the mice receiving control CAR-NK cells. Additionally, TRII/21 R co-expression enhanced NK cells' infiltration, activation, and persistence within the tumor, indicating a robust anti-tumor response mediated by the JAK-STAT3 signaling pathway. This study underscores the therapeutic potential of TRII/21R-modified CAR-NK cells as a breakthrough strategy for combating cancer.

Preclinical and Clinical-Scale Magnetic Particle Imaging of Natural Killer Cells: in vitro and ex vivo Demonstration of Cellular Sensitivity, Resolution, and Quantification

PURPOSE

Clinical adoption of NK cell immunotherapy is underway for medulloblastoma and osteosarcoma, however there is currently little feedback on cell fate after administration. We propose magnetic particle imaging (MPI) may have applications for the quantitative detection of NK cells.

PROCEDURES

Human-derived NK-92 cells were labeled by co-incubation with iron oxide nanoparticles (VivoTrax™) for 24 h then excess nanoparticles were washed with centrifugation. Cytolytic activity of labeled versus unlabeled NK-92 cells was assessed after 4 h of co-incubation with medulloblastoma cells (DAOY) or osteosarcoma cells (LM7 or OS17). Labeled NK-92 cells at two different doses (0.5 or 1 × 106) were administered to excised mouse brains (cerebellum), fibulas, and lungs then imaged by 3D preclinical MPI (MOMENTUM™) for detection relative to fiducial markers. NK-92 cells were also imaged by clinical-scale MPI under development at Magnetic Insight Inc.

RESULTS

NK-92 cells were labeled with an average of 3.17 pg Fe/cell with no measurable effects on cell viability or cytolytic activity against 3 tumor cell lines. MPI signal was directly quantitative with the number of labeled NK-92 cells, with preclinical limit of detection of 3.1 × 104 cells on MOMENTUM imager. Labeled NK-92 cells could be accurately localized in mouse brains, fibulas, and lungs within < 1 mm of stereotactic injection coordinates with preclinical scanner. Feasibility for detection on a clinical-scale MPI scanner was demonstrated using 4 × 107 labeled NK-92 cells, which is in the range of NK cell doses administered in our previous clinical trial.

CONCLUSION

MPI can provide sensitive, quantitative, and accurate spatial information on NK cells soon after delivery, showing initial promise to address a significant unmet clinical need to track NK cell fate in patients.

Optimizing the procedure for manufacturing clinical-grade genetically manipulated natural killer cells for adoptive immunotherapy

BACKGROUND AIMS

Ex vivo-expanded natural killer (NK) cells hold significant potential as antitumor effector cells for adoptive immunotherapy. However, producing clinical-grade, genetically modified NK cells in sufficient quantities presents a considerable challenge.

METHODS

We tested RPMI 1640, KBM581, SCGM, NK MACS, X-VIVO 15 and AIM-V, each supplemented with fetal bovine serum, human AB serum, human platelet lysate or Immune Cell Serum Replacement (SR) combined with feeder cells, to produce cytotoxic NK cells. Subsequent analyses were conducted to assess cell viability, expansion folds, cytotoxicity, immunophenotype and transcriptome profile of NK cells under certain conditions. Furthermore, transfer plasmids varying in transgene size, promoter elements, backbones and packaging plasmids with different envelopes were used to transduce NK cells, and differences in transduction efficiency were compared. Nucleofection was performed every 2 days from day 0 to day 12 to determine the optimal time window for gene editing.

RESULTS

NK cells cultured in KBM581 medium supplemented with serum replacement exhibited the best expansion, achieving greater than 5000-fold increase within 2 weeks and exceeding 25 000-fold expansion within 3 weeks. In addition, NK cells cultured in KBM581 medium with human AB serum demonstrated the greatest cytolytic activities and exhibited greater expression of NKp30, 2B4, PRF1, granzyme B and IL2RG. Baboon envelope pseudotyped lentivirus outperformed baboon envelope-vesicular stomatitis virus type G hybrid envelope lentivirus, achieving robust NK-cell transduction. In addition, efficient gene knockout efficiency was achieved in NK cells on day 4 to day 6 post feeder cell activation using the LONZA DN-100 program, which can strike a balance between editing efficiency and cell expansion.

CONCLUSIONS

This research presents a Good Manufacturing Practice-compliant protocol using a feeder cell expansion system for the large-scale production of highly cytotoxic NK cells. The protocol facilitates genetic modification of these cells, positioning them as promising candidates for universal therapeutic applications in immunotherapy.

Effects of Limosilactobacillus fermentum KBL375 on Immune Enhancement and Gut Microbiota Composition in Cyclophosphamide-Induced Immunosuppressed Mice

This study evaluated the immune-enhancing efficacy of Limosilactobacillus fermentum KBL375 isolated from the feces of healthy Koreans. KBL375-treated splenocytes showed enhancement of cytotoxicity against YAC-1 cells, the target of natural killer (NK) cells, with an increase in CD335, granzyme B, perforin, and interferon-gamma (IFN-γ). Oral administration of KBL375 in mice with cyclophosphamide (CP)-induced immunosuppression improved body weight and immune functions, including immune organ indices, lymphocyte proliferations, and immunoglobulin (Ig) A levels. Notably, KBL375 increased NK cell cytotoxicity and proportion in immunosuppressed mice. Perforin/IFN-γ expression levels, which indicated NK cell activation, were also increased in KBL375-treated mice. Furthermore, KBL375 led to an increase in beneficial microbes, such as Bifidobacterium, in the gut microbiome of immunosuppressed mice, fostering a favorable intestinal microbial environment. These comprehensive results suggest that KBL375 exhibits potent immune regulatory functions and positively influences the gut microbiota, implying its potential as a probiotic agent for immune enhancement.

Nanoparticle-mediated efficient up-regulation of GSDMD-N to induce pyroptosis and enhance NK cell-based cancer immunotherapy

Natural killer (NK) cell-based immunotherapy has emerged as a safe and effective therapeutic modality for cancer treatment. However, therapeutic benefits can be only seen in hematological tumors (e.g., leukemia) and the treatment of solid tumors is still less effective due to the immunosuppressive tumor microenvironment (TME)-induced poor infiltration and dysfunction of NK cells in tumor tissues. We herein developed a robust nucleus-targeted nanoparticle (NP) platform for systemic delivery of plasmid expressing the N-terminal domain of GSDMD (i.e., pGSDMD-N) and augment of NK cell-based immunotherapy for oral squamous cell carcinoma (OSCC). This nanoplatform is made of a PEGylated poly(2-(diisopropylamino) ethyl methacrylate) (PDPA) polymer and a nucleus-targeting peptide amphiphile (NTPA) that can complex pGSDMD-N. After intravenous administration, this nanoplatform could specifically deliver pGSDMD-N into the nuclei of OSCC cells, leading to their pyroptosis via up-regulating GSDMD-N expression. More importantly, this pyroptosis could boost NK cell-based immunotherapy via promoting the recruitment of NK cells into tumor tissues and enhancing their activation to further enhance the anticancer effect of the pGSDMD-N delivery system. STATEMENT OF SIGNIFICANCE: : NK cell-based immunotherapy has made a significant breakthrough in the treatment of hematological tumors (e.g., leukemia), but it is still less effective for solid tumors due to immunosuppressive tumor microenvironment (TME)-induced dysfunction of NK cells. We herein developed a nucleus-targeted nanoplatform for systemic delivery of plasmid expressing the N-terminal domain of gasdermin D (denoted pGSDMD-N) and augment of NK cell-based immunotherapy for oral squamous cell carcinoma (OSCC). This delivery system could not only induce the pyroptosis of OSCC cells, but also promote the secretion of functional chemokines (e.g., CCL3) and cytokines (e.g., IL-18) to boost NK cell-based immunotherapy. The strategy demonstrated herein could be a promising strategy to enhance the NK cell-based immunotherapy for solid tumors.

Enhanced Immune Functions of In Vitro Human Natural Killer Cells and Splenocytes in Immunosuppressed Mice Supplemented with Mature Silkworm Products

OBJECTIVES

The immune-enhancing properties of steamed mature silkworm, known as HongJam (HJ), were investigated using human interleukin-2-independent Natural Killer 92 (NK92-MI) cells and a cyclophosphamide intraperitoneal injection-induced immunosuppressed mice model (CPA-IP). White Jade variety mature silkworm HJ (WJ-HJ) was used to prepare WJ-HJ supercritical fluid extracts (WJ-SCE) and WJ-HJ-supplemented feeds.

RESULTS

Treatment with WJ-SCE significantly enhanced proliferation, migration, and cytotoxicity of NK92-MI cells against various cancer cells while improving mitochondrial function and ATP production (p < 0.05). In CPA-IP mice, consumption of WJ-HJ-supplemented feeds restored immune function by improving body weight, immune organ indices, immunoglobulin levels, and blood cytokines. Splenocyte proliferation and cytotoxicity were significantly elevated in both saline intraperitoneal injection (Sal-IP) and CPA-IP groups with WJ-HJ supplementation, independent of mitogen activation (p < 0.05).

CONCLUSIONS

These results suggest that WJ-HJ enhances immune modulation and immune surveillance functions of NK cells by improving mitochondrial and cytotoxic functions. WJ-HJ holds promise as a functional food for immune enhancement, pending clinical validation.

Targeting Triple NK Cell Suppression Mechanisms: A Comprehensive Review of Biomarkers in Pancreatic Cancer Therapy

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with poor outcomes due to frequent recurrence, metastasis, and resistance to treatment. A major contributor to this resistance is the tumor's ability to suppress natural killer (NK) cells, which are key players in the immune system's fight against cancer. In PDAC, the tumor microenvironment (TME) creates conditions that impair NK cell function, including reduced proliferation, weakened cytotoxicity, and limited tumor infiltration. This review examines how interactions between tumor-derived factors, NK cells, and the TME contribute to tumor progression and treatment resistance. To address these challenges, we propose a new "Triple NK Cell Biomarker Approach". This strategy focuses on identifying biomarkers from three critical areas: tumor characteristics, TME factors, and NK cell suppression mechanisms. This approach could guide personalized treatments to enhance NK cell activity. Additionally, we highlight the potential of combining NK cell-based therapies with conventional treatments and repurposed drugs to improve outcomes for PDAC patients. While progress has been made, more research is needed to better understand NK cell dysfunction and develop effective therapies to overcome these barriers.

Iron Knights with Nanosword Induced Ferroptosis in the Battle Against Oral Carcinoma

Oral squamous cell carcinoma (OSCC) is a tumor characterized by cellular redox imbalance, rendering it particularly sensitive to ferroptosis treatment. However, traditional ferroptosis inducers have a few drawbacks. In this study, ultrasmall AuMn nanoclusters (AMNCs) with a bovine serum albumin (BSA) ligand were synthesized and encapsulated in natural killer (NK) cell-derived exosomes to form an Exo-AMNCs composite for targeted ferroptosis therapy of OSCC. Unlike previously reported alloyed metal nanoclusters, not only do AMNCs react with intracellular H2O2 to produce reactive oxygen species (ROS) and induce ferroptosis but also the BSA ligand improves biocompatibility and water solubility. These properties render AMNCs ideal for fluorescence imaging in vivo. When combined with NK cell exosomes, the Exo-AMNCs composite exhibited strong targeted imaging and therapeutic effects on OSCC. Further investigation into the mechanistic details demonstrated that Exo-AMNCs downregulate the overexpression of fat mass and obesity-associated (FTO) in OSCC and regulate the key ferroptosis-related protein glutathione peroxidase 4 (GPX4).

Novel and potent MICA/B antibody is therapeutically effective in KRAS LKB1 mutant lung cancer models

BACKGROUND

Concurrent KRAS LKB1 (STK11, KL) mutant non-small cell lung cancers (NSCLC) do not respond well to current immune checkpoint blockade therapies, however targeting major histocompatibility complex class I-related chain A or B (MICA/B), could pose an alternative therapeutic strategy through activation of natural killer (NK) cells.

METHODS

Expression of NK cell activating ligands in NSCLC cell line and patient data were analyzed. Cell surface expression of MICA/B in NSCLC cell lines was determined through flow cytometry while ligand shedding in both patient blood and cell lines was determined through ELISA. We engineered an antibody-dependent cellular cytotoxicity (ADCC) enhanced MICA/B monoclonal antibody, AHA-1031, which prevents ligand shedding without interfering with binding to natural killer group 2D while targeting cancer cells via superior ADCC. We performed in vitro assays using ELISA and flow cytometry-based assays to confirm that our antibody potently binds to and stabilizes MICA/B expression across lung cancer and other solid tumor cell lines. Additionally, we used two KL mutant NSCLC cell lines and a KL mutant patient-derived xenograft (PDX) model to demonstrate in vivo antitumor efficacy and flow cytometry analysis for immune cell activation profiling.

RESULTS

NSCLC cell lines exhibit high MICA/B expression and secrete soluble MICA/B in vitro. Soluble MICA/B is also detected in patient blood samples. AHA-1031 binds to the α3 domain of MICA/B, preventing shedding and targeting tumor cells to ADCC. AHA-1031 exhibits high affinity and specificity to MICA/B, preventing MICA/B shedding in tumor lines and inducing ADCC in vitro. Our antibody also effectively binds and stabilizes MICA/B expression in additional tumor types and demonstrates broad specificity. We show that in two KL mutant NSCLC xenograft models and a KL mutant PDX model, treatment with AHA-1031 monotherapy significantly inhibits tumor growth compared with vehicle-treated animals with no observable toxicity. Tumor tissues from treated mice exhibit significantly increased immune cell infiltrates and activated NK cell populations.

CONCLUSIONS

Activating NK cells through MICA/B stabilization and inducing ADCC offers an alternative and potent therapy option in KL tumors. MICA/B are shed across different tumors making this therapeutic strategy universally applicable.

Reprogramming of Glucose Metabolism for Revisiting Hepatocellular Carcinoma Resistance to Transcatheter Hepatic Arterial Chemoembolization

Hepatocellular carcinoma (HCC) is recognized globally as one of the most lethal tumors, presenting a significant menace to patients' lives owing to its exceptional aggressiveness and tendency to recur. Transcatheter hepatic arterial chemoembolization (TACE) therapy, as a first-line treatment option for patients with advanced HCC, has been proven effective. However, it is disheartening that nearly 40 % of patients exhibit resistance to this therapy. Consequently, this review delves into the metabolic aspects of glucose metabolism to explore the underlying mechanisms behind TACE treatment resistance and to propose potentially fruitful therapeutic strategies. The ultimate objective is to present novel insights for the development of personalized treatment methods targeting HCC.

Targeting protein modification: a new direction for immunotherapy of pancreatic cancer

Post-translational modifications (PTMs) alter protein conformation by covalently attaching functional groups to substrates, influencing their biological activity, mechanisms of action, and functional performance. PTMs and their interactions are essential to many critical signal transduction processes, including tumor transformation, cancer progression, and metastasis in pancreatic cancer. Additionally, advancements in tumor immunotherapy indicate that PTMs are essential in immune cell activation, transport, and energy metabolism. This study aimed to investigate the effects of different PTMs on immunotherapy for pancreatic cancer, providing new perspectives and suggesting directions for future research.

Activated neutrophils: A next generation cellular immunotherapy

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

Machine learning identification of NK cell immune characteristics in hepatocellular carcinoma based on single-cell sequencing and bulk RNA sequencing

BACKGROUND

Hepatocellular carcinoma (HCC) is a highly malignant tumor; however, its immune microenvironment and mechanisms remain elusive. Single-cell sequencing allows for the exploration of immune characteristics within tumor at the cellular level. However, current knowledge regarding the roles of different immune cell populations in liver cancer progression is limited.

OBJECTIVE

The main objective of this study is to identify molecular markers with NK cell immune characteristics in hepatocellular carcinoma using various machine learning methods based on Single-Cell Sequencing and Bulk RNA Sequencing.

METHODS

We collected samples from eight normal liver tissues and eight HCC tumor tissues and performed single-cell RNA sequencing for immune cell clustering and expression profile analysis. Using various bioinformatic approaches, we investigated the immune phenotype associated with natural killer (NK) cells expressing high CD7 level. In addition, we verified the role of CD7 in the growth of HCC after NK cell and HCC cells cocultured by RT-qPCR, MTS and Flow cytometer experiments. Finally, we constructed a machine learning model to develop a prognostic prediction system for HCC based on NK cell-related genes.

RESULTS

Through single-cell typing, we found that the proportions of hepatocytes and NK cells were significantly elevated in the tumor samples. Moreover, we found that the expression of CD7 was high in HCC and correlated with prognosis. More importantly, Overexpression of CD7 in NK cells significantly inhibited the activity of MHCC97 cells and increased the number of apoptosis of HCC cells (p < 0.05). Furthermore, we observed that NK cells with high CD7 expression were associated with an activated immune phenotype.

CONCLUSION

Our study found that CD7 is an important biomarker for assessing immune status and predicting survival of HCC patients; hence, it is a potential target for immune therapy against HCC.

Cell type-specific upregulation of NKG2D ligand MICA in response to APTO253

One of the most important targets for natural killer (NK) cell-mediated therapy is the induction of natural killer group 2D ligand (NKG2D-L) expression. APTO253 is a small molecule that selectively kills acute myeloid leukemia (AML) cells, and it has been reported that APTO253 can induce Krüppel-like factor 4 (KLF4) expression and downregulate c-MYC expression. Recently, we discovered a novel role of APTO253 in modulating the NK cell response by inducing surface expression of NKG2D-Ls, especially MHC class I polypeptide-related sequence A (MICA), in AML cells. In this study, we extended the research to validate the effect of APTO253 in other cancer cell lines and found that the enhanced expression of NKG2D-Ls in response to APTO253 is limited in a tumor cell-specific manner. Here, we show that MICA induction upon treatment with APTO253 not only varies between ovarian and pancreatic cancer cell lines but also differs in two ovarian cancer cell lines for an unknown reason. Additionally, our data suggest a link between the induced expression of MICA and the regulation of both, KLF4 and c-MYC, which might represent a mechanism underlying the induction of NKG2D-L expression upon treatment with APTO253. These results may contribute to the potential use of APTO253 as a treatment to improve tumor cell-mediated NK cell cytotoxicity in various cancers.

Innate Immune Cell Profiling in Peripheral Blood Mononuclear Cells of Patients with Moyamoya Disease

Moyamoya disease (MMD) is a rare cerebrovascular disease characterized by stenosis or occlusion of the internal carotid artery, thus leading to ischaemic and haemorrhagic strokes. Although genetic studies have identified ring finger protein 213 (RNF213) as a susceptibility gene, the low disease penetrance suggests that a secondary trigger, such as infection, may initiate disease onset. This study aimed to characterize the innate immune cell profile of peripheral blood mononuclear cells (PBMCs) of MMD patients via mass cytometry (CyTOF). Blood samples from 10 MMD patients and 10 healthy controls were analysed, with a focus on natural killer (NK) cells, monocytes, and dendritic cells (DCs). The results revealed significant changes in the NK and monocyte subpopulations in MMD patients; specifically, there was a decrease in the CD56dimCD16- NK03 subset and an increase in CD163high classical monocytes, thus indicating compromised microbial defences and heightened inflammation. Additionally, significant changes were observed in DC subpopulations, including an increase in CCR7+ mature DCs and a decrease in CD141+ and CD1c+ DCs. Overactivation of the TLR/MyD88/NF-κB pathway was observed in most innate immune cells, thus indicating its potential role in disease progression. These findings provide novel insights into immune dysfunction in MMD and highlight potential therapeutic targets.

Targeting caspase-8: a new strategy for combating hepatocellular carcinoma

Hepatocellular carcinoma (HCC) represents the most prevalent form of primary liver cancer and has a high mortality rate. Caspase-8 plays a pivotal role in an array of cellular signaling pathways and is essential for the governance of programmed cell death mechanisms, inflammatory responses, and the dynamics of the tumor microenvironment. Dysregulation of caspase-8 is intricately linked to the complex biological underpinnings of HCC. In this manuscript, we provide a comprehensive review of the regulatory roles of caspase-8 in apoptosis, necroptosis, pyroptosis, and PANoptosis, as well as its impact on inflammatory reactions and the intricate interplay with critical immune cells within the tumor microenvironment, such as tumor-associated macrophages, T cells, natural killer cells, and dendritic cells. Furthermore, we emphasize how caspase-8 plays pivotal roles in the development, progression, and drug resistance observed in HCC, and explore the potential of targeting caspase-8 as a promising strategy for HCC treatment.

The development and application of chimeric antigen receptor natural killer (CAR-NK) cells for cancer therapy: current state, challenges and emerging therapeutic advances

Immunotherapy has transformed the landscape of cancer treatment, with chimeric antigen receptor (CAR)-engineered T (CAR-T) cell therapy emerging as a front runner in addressing some hematological malignancies. Despite its considerable efficacy, the occurrence of severe adverse effects associated with CAR-T cell therapy has limited their scope and prompted the exploration of alternative therapeutic strategies. Natural killer (NK) cells, characterized by both their innate cytotoxicity and ability to lyse target cells without the constraint of peptide specificity conferred by a major histocompatibility complex (MHC), have similarly garnered attention as a viable immunotherapy. As such, another therapeutic approach has recently emerged that seeks to combine the continued success of CAR-T cell therapy with the flexibility of NK cells. Clinical trials involving CAR-engineered NK (CAR-NK) cell therapy have exhibited promising efficacy with fewer deleterious side effects. This review aims to provide a concise overview of the cellular and molecular basis of NK cell biology, facilitating a better understanding of advancements in CAR design and manufacturing. The focus is on current approaches and strategies employed in CAR-NK cell development, exploring at both preclinical and clinical settings. We will reflect upon the achievements, advantages, and challenges intrinsic to CAR-NK cell therapy. Anticipating the maturation of CAR-NK cell therapy technology, we foresee its encouraging prospects for a broader range of cancer patients and other conditions. It is our belief that this CAR-NK progress will bring us closer to making significant strides in the treatment of refractory and recurrent cancers, as well as other immune-mediated disorders.

NK/DC crosstalk-modulating antitumor activity via Sema3E/PlexinD1 axis for enhanced cancer immunotherapy

The complex relationship between natural killer (NK) cells and dendritic cells (DCs) within the tumor microenvironment significantly impacts the success of cancer immunotherapy. Recent advancements in cancer treatment have sought to bolster innate and adaptive immune responses through diverse modalities, aiming to tilt the immune equilibrium toward tumor elimination. Optimal antitumor immunity entails a multifaceted interplay involving NK cells, T cells and DCs, orchestrating immune effector functions. Although DC-based vaccines and NK cells' cytotoxic capabilities hold substantial therapeutic potential, their interaction is frequently hindered by immunosuppressive elements such as myeloid-derived suppressor cells (MDSCs) and regulatory T cells. Chemokines and cytokines, such as CXCL12, CCL2, interferons, and interleukins, play crucial roles in modulating NK/DC interactions and enhancing immune responses. This review elucidates the mechanisms underlying NK/DC interaction, emphasizing their pivotal roles in augmenting antitumor immune responses and the impediments posed by tumor-induced immunosuppression. Furthermore, it explores the therapeutic prospects of restoring NK/DC crosstalk, highlighting the significance of molecules like Sema3E/PlexinD1 in this context, offering potential avenues for enhancing the effectiveness of current immunotherapeutic strategies and advancing cancer treatment paradigms. Harnessing the dynamic interplay between NK and DC cells, including the modulation of Sema3E/PlexinD1 signaling, holds promise for developing more potent therapies that harness the immune system's full potential in combating cancer.

Advances in Induced Pluripotent Stem Cell-Derived Natural Killer Cell Therapy

Natural killer (NK) cells are cytotoxic lymphocytes of the innate immune system capable of killing virus-infected cells and/or cancer cells. The commonly used NK cells for therapeutic applications include primary NK cells and immortalized NK cell lines. However, primary NK cell therapy faces limitations due to its restricted proliferation capacity and challenges in stable storage. Meanwhile, the immortalized NK-92 cell line requires irradiation prior to infusion, which reduces its cytotoxic activity, providing a ready-made alternative and overcoming these bottlenecks. Recent improvements in differentiation protocols for iPSC-derived NK cells have facilitated the clinical production of iPSC-NK cells. Moreover, iPSC-NK cells can be genetically modified to enhance tumor targeting and improve the expansion and persistence of iPSC-NK cells, thereby achieving more robust antitumor efficacy. This paper focuses on the differentiation-protocols efforts of iPSC-derived NK cells and the latest progress in iPSC-NK cell therapy. Additionally, we discuss the current challenges faced by iPSC-NK cells and provide an outlook on future applications and developments.

Enhanced CCR2 expression by ACKR2-deficient NK cells increases tumoricidal cell therapy efficacy

Chemokines regulate leukocyte navigation to inflamed sites and specific tissue locales and may therefore be useful for ensuring accurate homing of cell therapeutic products. We, and others, have shown that atypical chemokine receptor 2 (ACKR2)-deficient mice (ACKR2-/-) are protected from metastasis development in cell line and spontaneous mouse models. We have shown that this relates to enhanced CCR2 expression on ACKR2-/- natural killer cells, allowing them to home more effectively to CCR2 ligand-expressing metastatic deposits. Here we demonstrate that the metastatic-suppression phenotype in ACKR2-/- mice is not a direct effect of the absence of ACKR2. Instead, enhanced natural killer cell CCR2 expression is caused by passenger mutations that originate from the creation of the ACKR2-/- mouse strain in 129 embryonic stem cells. We further demonstrate that simple selection of CCR2+ natural killer cells enriches for a population of cells with enhanced antimetastatic capabilities. Given the widespread expression of CCR2 ligands by tumors, our study highlights CCR2 as a potentially important contributor to natural killer cell tumoricidal cell therapy.

Can the Analysis of Toll-like Receptors (TLR) on NK and NKT-like Cells Improve Gastric Cancer Diagnostics and Treatment?

Background/Objectives: The aim of this study was to determine the assessment of the percentage of NK and NKT-like cells expressing Toll-like receptors (TLR-2, TLR-3, TLR-4, and TLR-9) in patients with gastric cancer (GC) compared with healthy volunteers (HV) and to investigate differences according to cancer subtype. We also assessed TLR gene expression by RT-qPCR to assess whether TLRs could be diagnostic and prognostic biomarkers. Methods: The study included 86 patients with histologically confirmed gastric cancer and 30 healthy volunteers. Peripheral blood samples were collected from the participants, and TLR expression on NK and NKT-like cells was assessed by flow cytometry and RT-qPCR. The expression of TLR2, TLR3, TLR4, and TLR9 genes was assessed using genetic material derived from NK and NKT-like cells sourced from PBMC. The obtained results were statistically analyzed using Mann-Whitney U and Kruskal-Wallis tests, and the predictive ability of variables was assessed using ROC curve analysis. Results: A significantly higher expression of TLR receptors (TLR-2, TLR-3, TLR-4, and TLR-9) was found in patients with gastric cancer compared to healthy volunteers (p < 0.05). TLR expression also differed depending on the cancer subtype, and higher expression was observed in more advanced GC subtypes. RT-qPCR analysis showed significantly increased expression of TLR genes in the group of GC patients. ROC curves indicate a high ability of TLRs to differentiate between GC patients and healthy individuals. Conclusions: The expression of TLRs on NK and NKT-like cells is clearly increased in patients with gastric cancer, especially in more advanced subtypes of the tumor. The results suggest that TLRs could potentially be used as diagnostic and prognostic biomarkers and represent potential targets for immune therapies in GC. However, further studies are needed to determine the functional role of TLRs in disease progression and the possibility of their use in personalized treatment.

Single-cell data revealed the regulatory mechanism of TNK cell heterogeneity in liver metastasis from gastric cancer

AIM

The present work set out to classify cell subpopulations related to liver metastasis from gastric cancer (GC) and the mechanisms of their interactions with other immune cell subpopulations.

BACKGROUND

GC is characterized by a high degree of heterogeneity and liver metastasis. Exploring the mechanism of liver metastasis of GC from the perspective of heterogeneity of the tumor microenvironment (TME) might help improve the efficacy of GC treatment.

OBJECTIVE

Based on the cellular subpopulation characteristics of GC with liver metastasis, the regulatory mechanisms contributing to GC progression were analyzed, with special focuses on the roles of signaling pathways, transcription factors (TFs) and ligand-receptor pairs.

METHODS

The GSE163558 dataset was downloaded from the Gene Expression Omnibus (GEO) database to collect single-cell transcriptomic data of GC patients and their metastasis groups for cell clustering and relevant analyses. Differentially expressed genes (DEGs) in the GC and GC liver metastasis groups were screened and subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. SCENIC analysis was used to mine TFs that affected cellular subpopulations during liver metastasis from GC. The relative expression levels of TFs in GC were determined using qRT-PCR. Transwell and wound healing assays were utilized to verify the regulation of the TFs on the migration and invasion of GC cells. Interaction network between the cellular subpopulations was developed applying CellChat.

RESULTS

Single-cell clustering was performed to group six major cell subpopulations, namely, Myeloid cells, B cells, Mast cells, Epithelial cells, Fibroblasts, and TNK cells, among which the number of TNK cells was significantly increased in the GC liver metastasis group. Differentially enriched pathways of TNK cells between GC and GC liver metastasis groups mainly included IL-17 and Pi3k-Akt signaling pathways. TNK cell subsets could be further categorized into CD8 T cells, Exhausted T cells, NK cells, NKT cells, and Treg cells, with the GC liver metastasis group showing significantly more CD8 T cells and NKT cells. FOS and JUNB were the TFs of TNK cell marker genes that contributed to liver metastasis from GC and the invasion and migration of GC cell lines. Significant differences in immune cell communication ligand-receptor pairs existed between the GC and GC liver metastasis groups.

CONCLUSION

This study revealed the critical role of TNK cell subsets in GC with liver metastasis applying single-cell transcriptomics analysis. The findings provided an important theoretical basis for developing novel therapies to inhibit liver metastasis from GC.

Metabolic programs drive function of therapeutic NK cells in hypoxic tumor environments

Limited oxygen (hypoxia) in solid tumors poses a challenge to successful immunotherapy with natural killer (NK) cells. NK cells have impaired cytotoxicity when cultured in hypoxia (1% oxygen) but not physiologic (>5%) or atmospheric oxygen (20%). We found that changes to cytotoxicity were regulated at the transcriptional level and accompanied by metabolic dysregulation. Dosing with interleukin-15 (IL-15) enhanced NK cell cytotoxicity in hypoxia, but preactivation with feeder cells bearing IL-21 and 4-1BBL was even better. Preactivation resulted in less perturbed metabolism in hypoxia; greater resistance to oxidative stress; and no hypoxia-induced loss of transcription factors (T-bet and Eomes), activating receptors, adhesion molecules (CD2), and cytotoxic proteins (TRAIL and FasL). There remained a deficit in CD122/IL-2Rβ when exposed to hypoxia, which affected IL-15 signaling. However, tri-specific killer engager molecules that deliver IL-15 in the context of anti-CD16/FcγRIII were able to bypass this deficit, enhancing cytotoxicity of both fresh and preactivated NK cells in hypoxia.

An Extended Flow Cytometry Evaluation of ex Vivo Expanded NK Cells Using K562.Clone1, a Feeder Cell Line Manufactured in Brazil

Natural killer (NK) cells play a crucial role in the immune system's response against cancer. However, the challenge of obtaining the required quantity of NK cells for effective therapeutic response necessitates the development of strategies for their ex vivo expansion. This study aimed to develop a novel feeder cell line, K562.Clone1, capable of promoting the ex vivo expansion of NK cells while preserving their cytotoxic potential. he K562 leukemic cell line was transduced with mbIL-21 and 4-1BBL proteins to generate K562.Clone1 cells. NK cells were then co-cultured with these feeder cells, and their expansion rate was monitored over 14 days. The cytotoxic potential of the expanded NK cells was evaluated against acute myeloid leukemia blasts and tumor cell lines of leukemia and glial origin. Statistical analysis was performed to determine the significance of the results. The K562.Clone1 co-cultured with peripheral NK showed a significant increase in cell count, with an approximate 94-fold expansion over 14 days. Expanded NK cells demonstrated cytotoxicity against the tested tumor cell lines, indicating preservation of their cytotoxic characteristics. Additionally, the CD56, CD16, inhibitory KIRs, and activation receptors were conserved and present in a well-balanced manner. The study successfully developed a feeder cell line, K562.Clone1, that effectively promotes the expansion of NK cells ex vivo while maintaining their cytotoxic potential. This development could significantly contribute to the advancement of NK cell therapy, especially in Brazil.

Cell-drug conjugates

By combining living cells with therapeutics, cell-drug conjugates can potentiate the functions of both components, particularly for applications in drug delivery and therapy. The conjugates can be designed to persist in the bloodstream, undergo chemotaxis, evade surveillance by the immune system, proliferate, or maintain or transform their cellular phenotypes. In this Review, we discuss strategies for the design of cell-drug conjugates with specific functions, the techniques for their preparation, and their applications in the treatment of cancers, autoimmune diseases and other pathologies. We also discuss the translational challenges and opportunities of this class of drug-delivery systems and therapeutics.

CRISPR/Cas9-mediated knockout strategies for enhancing immunotherapy in breast cancer

Breast cancer, a prevalent disease with significant mortality rates, often presents treatment challenges due to its complex genetic makeup. This review explores the potential of combining Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) gene knockout strategies with immunotherapeutic approaches to enhance breast cancer treatment. The CRISPR/Cas9 system, renowned for its precision in inducing genetic alterations, can target and eliminate specific cancer cells, thereby minimizing off-target effects. Concurrently, immunotherapy, which leverages the immune system's power to combat cancer, has shown promise in treating breast cancer. By integrating these two strategies, we can potentially augment the effectiveness of immunotherapies by knocking out genes that enable cancer cells to evade the immune system. However, safety considerations, such as off-target effects and immune responses, necessitate careful evaluation. Current research endeavors aim to optimize these strategies and ascertain the most effective methods to stimulate the immune response. This review provides novel insights into the integration of CRISPR/Cas9-mediated knockout strategies and immunotherapy, a promising avenue that could revolutionize breast cancer treatment as our understanding of the immune system's interplay with cancer deepens.

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.

Integrated analysis of bulk and single-cell RNA sequencing reveals the impact of nicotinamide and tryptophan metabolism on glioma prognosis and immunotherapy sensitivity

BACKGROUND

Nicotinamide and tryptophan metabolism play important roles in regulating tumor synthesis metabolism and signal transduction functions. However, their comprehensive impact on the prognosis and the tumor immune microenvironment of glioma is still unclear. The purpose of this study was to investigate the association of nicotinamide and tryptophan metabolism with prognosis and immune status of gliomas and to develop relevant models for predicting prognosis and sensitivity to immunotherapy in gliomas.

METHODS

Bulk and single-cell transcriptome data from TCGA, CGGA and GSE159416 were obtained for this study. Gliomas were classified based on nicotinamide and tryptophan metabolism, and PPI network associated with differentially expressed genes was established. The core genes were identified and the risk model was established by machine learning techniques, including univariate Cox regression and LASSO regression. Then the risk model was validated with data from the CGGA. Finally, the effects of genes in the risk model on the biological behavior of gliomas were verified by in vitro experiments.

RESULTS

The high nicotinamide and tryptophan metabolism is associated with poor prognosis and high levels of immune cell infiltration in glioma. Seven of the core genes related to nicotinamide and tryptophan metabolism were used to construct a risk model, and the model has good predictive ability for prognosis, immune microenvironment, and response to immune checkpoint therapy of glioma. We also confirmed that high expression of TGFBI can lead to an increased level of migration, invasion, and EMT of glioma cells, and the aforementioned effect of TGFBI can be reduced by FAK inhibitor PF-573,228.

CONCLUSIONS

Our study evaluated the effects of nicotinamide and tryptophan metabolism on the prognosis and tumor immune microenvironment of glioma, which can help predict the prognosis and sensitivity to immunotherapy of glioma.

Diagnosis of canine B-cell chronic lymphoid leukemia with a CD21 negative phenotype using the LT21 clone CD21 antibody in flow cytometry: a case report

BACKGROUND

Chronic lymphoid leukemia (CLL) is a hematological disorder characterized by the clonal expansion of small mature lymphocytes that accumulate in the blood and bone marrow. CLL can arise from B-, T-, or natural killer cell clones. The cytological evaluation of blood smears is often the simplest and least invasive method for diagnosing lymphoid leukemia. Immunophenotyping is used to further subclassify the type of lymphoid leukemia.

CASE PRESENTATION

A 15-year-old, 4.4-kg spayed female Shih Tzu was presented to the veterinary medical teaching hospital of Kangwon National University. Despite having a normal appetite and activity level, cervical and inguinal lymph node enlargement was noted on physical examination. Complete blood count revealed severe leukocytosis, severe lymphocytosis, and monocytosis. Splenomegaly, hepatomegaly, and lymph node enlargement were detected on radiographic and ultrasonographic examination. Immunophenotyping was performed using peripheral blood mononuclear cells (PBMCs). The majority of lymphocytes exhibited the following profiles: CD3-CD79a- (97.5%), CD4-CD8- (98.6%), CD21-CD79a- (98.4%), CD34- (0.1%), CD45+ (99.6%), major histocompatibility complex class II+ (99.5%), and CD14- (0.5%). Based on the immunophenotyping results, possible differentials considered included the following: the majority of lymphocytes may be natural killer (NK) cell clones, plasma cell clones, or show aberrant expression or loss of CD21 marker due to the neoplastic nature of the cells. Further flow cytometry was performed using antibodies against CD3, CD5, CD94, and granzyme B. The combined results indicated that the predominant lymphocyte subset in the PBMCs was CD3-CD5-CD21-CD94-granzyme B-. To confirm monoclonality and exclude the aberrant loss of CD markers, a polymerase chain reaction for antigen receptor rearrangement (PARR) assay was conducted. The PARR assay, using DNA from blood and lymph node samples, showed B-cell monoclonality. Immunocytochemistry using PBMCs showed that the plasma cell marker Multiple Myeloma Oncogene 1 (MUM1) was not expressed. Therefore, the diagnosis was confirmed to be B-cell CLL.

CONCLUSION

Immunophenotyping can help subclassify the type of lymphoid leukemia; however, as tumor cells can show aberrant expression or loss of the CD21 marker, combining immunophenotyping with the PARR assay could yield a more accurate diagnosis.

Cell Surface Engineering by Phase-Separated Coacervates for Antibody Display and Targeted Cancer Cell Therapy

Cell therapies such as CAR-T have demonstrated significant clinical successes, driving the investigation of immune cell surface engineering using natural and synthetic materials to enhance their therapeutic performance. However, many of these materials do not fully replicate the dynamic nature of the extracellular matrix (ECM). This study presents a cell surface engineering strategy that utilizes phase-separated peptide coacervates to decorate the surface of immune cells. We meticulously designed a tripeptide, Fmoc-Lys-Gly-Dopa-OH (KGdelta; Fmoc=fluorenylmethyloxycarbonyl; delta=Dopa, dihydroxyphenylalanine), that forms coacervates in aqueous solution via phase separation. These coacervates, mirroring the phase separation properties of ECM proteins, coat the natural killer (NK) cell surface with the assistance of Fe3+ ions and create an outer layer capable of encapsulating monoclonal antibodies (mAb), such as Trastuzumab. The antibody-embedded coacervate layer equips the NK cells with the ability to recognize cancer cells and eliminate them through enhanced antibody-dependent cellular cytotoxicity (ADCC). This work thus presents a unique strategy of cell surface functionalization and demonstrates its use in displaying cancer-targeting mAb for cancer therapies, highlighting its potential application in the field of cancer therapy.

Efficacy and safety of natural killer cell therapy in patients with solid tumors: a systematic review and meta-analysis

Introduction

In 2020, global cancer statistics reported 19.3 million new cases and 10 million deaths annually, highlighting the urgent need for effective treatments. Current therapies, such as surgery, radiation, and chemotherapy, have limitations in comprehensively addressing solid tumor. Recent advances in cancer biology and immuno-oncology, including CAR-T cell therapy, show promise but face efficacy challenges against solid tumors.

Methods

This meta-analysis systematically reviewed studies from PubMed, Embase, Cochrane, and ClinicalTrials.gov databases up to May 2024 to evaluate the clinical efficacy and safety of unmodified NK cell therapies in solid tumors. The included trials focused on reporting objective response rates (ORR).

Results

Thirty-one trials involving 600 patients across various cancers (e.g., NSCLC, HCC, breast, ovarian) were analyzed. NK cell therapies demonstrated promising ORRs, particularly 72.3% in hepatocellular carcinoma, often in combination with local therapies. Safety profiles were favorable, with fatigue being the most common adverse event.

Discussion

NK cell therapies represent a promising treatment option for solid tumors, offering a viable alternative to genetically modified cell therapies like CAR-T. Further research is needed to optimize the clinical utility of NK cell therapy and integrate it effectively into standard cancer treatment regimens.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023438410, identifier CRD42023438410.

Identification of Immune-Related Gene Signature Model for Predicting Lung Cancer Survival and Response to Immunotherapy

INTRODUCTION

Studies have shown that immune-related genes play a crucial role in tumor development and treatment. However, the specific roles and potential value of these genes in lung cancer patients are still not fully understood. Therefore, this study aims to establish a novel risk model based on immune-related genes for evaluating the prognostic risk and response to immune therapy in lung cancer patients.

METHODS

Gene expression and clinical data of lung cancer patients were retrieved from the Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases, while immune-related genes were obtained from the ImmPort database. A risk signature model was developed using univariate Cox analysis and LASSO regression analysis. The prognostic value of the model and its response to immunotherapy were analyzed by survival analysis, immune infiltration analysis, and immunotherapy response analysis.

RESULTS

We have developed a risk signature model based on eight key immune-related genes, which can classify patients into high-risk and low-risk groups. The prognosis of the high-risk group was significantly lower than that of the low-risk group and was validated in multiple GEO datasets. The mutation frequency was lower in the low-risk group compared to the high-risk group (TP53: 55% vs. 65%; TTN: 52% vs. 60%; CSMD3: 34% vs. 45%). Futhermore, CD274 expression was lower in the low-risk patients, and the high-risk patients in the IMvigor210 cohort had lower survival. Immune infiltration analyses showed that the high-risk group was negatively correlated with the infiltration level of B cells, CD4+ T cells, and NK cells. Importantly, patients in the low-risk group exhibit significantly lower TIDE scores, suggesting that they are more responsive to immunotherapy.

CONCLUSION

Our study has established a novel and robust immune-related gene risk model that can assist in evaluating the prognostic risk and immune therapy response of lung cancer patients.

Sequential Autologous CIK/NK Cells Combined with Chemotherapy to Induce Long-Term Tumor Control in Advanced Rectal Cancer: A Case Report

Objective

Colorectal carcinoma (CRC) is the third most common malignancy. In addition to comprehensive cancer treatments, such as surgery, chemotherapy, and radiotherapy, the adoptive immune cell therapy (ACT) has played an increasingly important role in recent years, and the adaptive transfusion of autologous NK cells and CIK cells is a brand-new approach to cellular therapy for solid tumors.

Case Presentation

A 57-year-old man underwent a radical resection of microsatellite stable (MSS) rectal cancer with synchronous liver metastases. After surgery of the primary lesion surgery, he was treated with autologous CIK/NK cells combined with XELOX translational therapy. Each cycle can obtain over 10 × 109 CIK cells or over 6 × 109 NK cells combined chemotherapy of XELOX every 3 weeks. After 2 cycles of therapy, he achieved partial response (PR). He immediately underwent a hepatic metastasis resection. After surgery, the patient continued to receive autologous CIK/NK cells in combined with 4 cycles of XELOX. To date, he has achieved and maintained no evidence of disease (NED) for over 40 months.

Conclusion

This is a case of successful treatment of rectal cancer with liver metastasis using ACT in conjunction with first-line chemotherapy. The advantage of this treatment plan is that it has few side effects and achieves long-term control of tumor recurrence by improving the patient's immune function. However, its responsiveness and benefit rate still need further investigation.

Identification of basement membrane-related prognostic model associated with the immune microenvironment and synthetic therapy response in pancreatic cancer: integrated bioinformatics analysis and clinical validation

Pancreatic cancer (PC) is a common and highly malignant tumor. Basement membrane (BM) is formed by the crosslinking of extracellular matrix macromolecules and acts as a barrier against tumor cell metastasis. However, the role of BM in PC prognosis, immune infiltration, and treatment remains unclear. This study collected transcriptome and clinical survival data of PC via TCGA, GEO, and ICGC databases. PC patients (PCs) from the First Affiliated Hospital of Dalian Medical University were obtained as the clinical validation cohort. BM-related genes (BMRGs) were acquired from GeneCards and basement membraneBASE databases. A total of 46 differential-expressed BMRGs were identified. Then the BM-related prognostic model (including DSG3, MET, and PLAU) was built and validated. PCs with a low BM-related score had a better outcome and were more likely to benefit from oxaliplatin, irinotecan, and KRAS(G12C) inhibitor-12, and immunotherapy. Immune analysis revealed that BM-related score was positively correlated with neutrophils, cancer-associated fibroblasts, and macrophages infiltration, but negatively correlated with CD8+ T cells, NK cells, and B cells infiltration. PCs from the clinical cohort further verified that BM-related model could accurately predict PCs' outcomes. DSG3, MET, and PLAU were notably up-regulated within PC tissues and linked to a poor prognosis. In vitro experiments showed that DSG3 knockdown markedly suppressed the proliferation, migration, and invasion of PC cells. Molecular docking indicated that epigallocatechin gallate had a strong binding activity with DSG3, MET, and PLAU and may be used as a potential therapeutic agent for PC. In conclusion, this study developed a BM-related model associated with PC prognosis, immune infiltration, and treatment, which provided new insights into PC stratification and drug intervention.

Beyond Cancer Cells: How the Tumor Microenvironment Drives Cancer Progression

Liver cancer represents a substantial global health challenge, contributing significantly to worldwide morbidity and mortality. It has long been understood that tumors are not composed solely of cancerous cells, but also include a variety of normal cells within their structure. These tumor-associated normal cells encompass vascular endothelial cells, fibroblasts, and various inflammatory cells, including neutrophils, monocytes, macrophages, mast cells, eosinophils, and lymphocytes. Additionally, tumor cells engage in complex interactions with stromal cells and elements of the extracellular matrix (ECM). Initially, the components of what is now known as the tumor microenvironment (TME) were thought to be passive bystanders in the processes of tumor proliferation and local invasion. However, recent research has significantly advanced our understanding of the TME's active role in tumor growth and metastasis. Tumor progression is now known to be driven by an intricate imbalance of positive and negative regulatory signals, primarily influenced by specific growth factors produced by both inflammatory and neoplastic cells. This review article explores the latest developments and future directions in understanding how the TME modulates liver cancer, with the aim of informing the design of novel therapies that target critical components of the TME.

Multiple cell-death patterns predict the prognosis and drug sensitivity of melanoma patients

Background

Melanoma, a malignant tumor of the skin, presents challenges in its treatment process involving modalities such as surgery, chemotherapy, and targeted therapy. However, there is a need for an ideal model to assess prognosis and drug sensitivity. Programmed cell death (PCD) modes play a crucial role in tumor progression and has the potential to serve as prognostic and drug sensitivity indicators for melanoma.

Methods

We analyzed 13 PCD modes including apoptosis, necroptosis, ferroptosis, pyroptosis, netotic cell death, entotic cell death, lysosome-dependent cell death, parthanatos, autophagy-dependent cell death, oxeiptosis, disulfidptosis, and alkaliptosis. These modes were used to construct a model that incorporated genes related to these 13 PCD modes to establish a cell death index (CDI) to conduct prognosis analysis. Transcriptomic, genomic, and clinical data were collected from cohorts including TCGA-SKCM, GSE19234, and GSE65904 to validate this model.

Results

A CDI consisting of ten gene signatures was established using machine learning algorithms and divided into two groups based on CDI values. The high CDI group exhibited relatively lower numbers of immune-infiltrating cells and showed resistance to commonly used drugs such as docetaxel and axitinib. Our validation results demonstrated good discrimination in PCA analysis between CDI groups, and melanoma patients with higher CDI values had worse postoperative prognoses (all p < 0.01).

Conclusion

The CDI model, incorporating multiple PCD modes, accurately predicts the clinical prognosis and drug sensitivity of melanoma patients.

Current Developments in NK Cell Engagers for Cancer Immunotherapy: Focus on CD16A and NKp46

NK cells are specialized immune effector cells crucial for triggering immune responses against aberrant cells. Although recent advancements have concentrated on creating or releasing T-cell responses specific to tumor Ags, the clinical advantages of this approach have been limited to certain groups of patients and tumor types. This emphasizes the need for alternative strategies. One pioneering approach involves broadening and enhancing anti-tumor immune responses by targeting innate immunity. Consequently, the advent of bi-, tri-, and multi-specific Abs has facilitated the advancement of targeted cancer immunotherapies by redirecting immune effector cells to eradicate tumor cells. These Abs enable the simultaneous binding of surface Ags on tumor cells and the activation of receptors on innate immune cells, such as NK cells, with the ability to facilitate Ab-dependent cellular cytotoxicity to enhance their immunotherapeutic effectiveness in patients with solid tumors. Here, we review the recent advances in NK cell engagers (NKCEs) focusing on NK cell-activating receptors CD16A and NKp46. In addition, we provide an overview of the ongoing clinical trials investigating the safety, efficacy, and potential of NKCEs.

Use of a platform with lens-free shadow imaging technology to monitor natural killer cell activity

Natural killer (NK) cells are a crucial component of the innate immune system. This study introduces Cellytics NK, a novel platform for rapid and precise measurement of NK cell activity. This platform combines an NK-specific activation stimulator cocktail (ASC) and lens-free shadow imaging technology (LSIT), using optoelectronic components. LSIT captures digital hologram images of resting and ASC-activated NK cells, while an algorithm evaluates cell size and cytoplasmic complexity using shadow parameters. The combined shadow parameter derived from the peak-to-peak distance and width standard deviation rapidly distinguishes active NK cells from inactive NK cells at the single-cell level within 30 s. Here, the feasibility of the system was demonstrated by assessing NK cells from healthy donors and immunocompromised cancer patients, demonstrating a significant difference in the innate immunity index (I3). Cancer patients showed a lower I3 value (161%) than healthy donors (326%). I3 was strongly correlated with NK cell activity measured using various markers such as interferon-gamma, tumor necrosis factor-alpha, perforin, granzyme B, and CD107a. This technology holds promise for advancing immune functional assays, offering rapid and accurate on-site analysis of NK cells, a crucial innate immune cell, with its compact and cost-effective optoelectronic setup, especially in the post-COVID-19 era.

Development in the Study of Natural Killer Cells for Malignant Peritoneal Mesothelioma Treatment

Malignant peritoneal mesothelioma (MPeM) is a rare primary malignant tumor originating from peritoneal mesothelial cells. Insufficient specificity of the symptoms and their frequent reappearance following surgery make it challenging to diagnose, creating a need for more efficient treatment options. Natural killer cells (NK cells) are part of the innate immune system and are classified as lymphoid cells. Under the regulation of activating and inhibiting receptors, NK cells secrete various cytokines to exert cytotoxic effects and participate in antiforeign body, antiviral, and antitumor activities. This review provides a comprehensive summary of the specific alterations observed in NK cells following MPeM treatment, including changes in cell number, subpopulation distribution, active receptors, and cytotoxicity. In addition, we summarize the impact of various therapeutic interventions, such as chemotherapy, immunotherapy, and targeted therapy, on NK cell function post-MPeM treatment.

AML cell-derived exosomes suppress the activation and cytotoxicity of NK cells in AML via PD-1/PD-L1 pathway

Exosomes are bilayer lipid bodies and contain a variety of bioactive molecules such as proteins, lipids, and nucleic acids, and so forth. Exosomes derived from solid tumors may play critical roles in tumor development and immune evasion. However, the underlying effects of tumor-derived exosomes on immune function in modulating intercellular crosstalk within the bone marrow niche during acute myeloid leukemia (AML) development and immune evasion remain largely elusive. In this study, we aimed to explore the role of AML-exos in AML immune evasion. First, we isolated tumor-derived exosomes from AML cells (AML-exos) and revealed the presence of programmed cell death ligand-1 (PD-L1) protein in AML-exos. Next, we demonstrated that AML-exos can directly suppress the activation of natural killer (NK) cells and inhibit the cytotoxicity of NK cells, probably through activating the programmed cell death-1 (PD-1)/PD-L1 pathway. Furthermore, the inhibitory effect of AML-exos on NK cells could be alleviated by either PD-L1 inhibitor or antagonist. In summary, we demonstrated that AML-exos possess a PD-L1-dependent tumor-promoting effect which may contribute to immune tolerance in antitumor therapy, but blocking the PD-1/PD-L1 pathway may alleviate the tumor immunosuppression induced by AML-exos. Our findings in this study may offer a new immunotherapy strategy to cure AML.

A bispecific nanosystem activates endogenous natural killer cells in the bone marrow for haematologic malignancies therapy

Haematologic malignancies commonly arise from the bone marrow lesion, yet there are currently no effective targeted therapies against tumour cells in this location. Here we constructed a bone-marrow-targeting nanosystem, CSF@E-Hn, which is based on haematopoietic-stem-cell-derived nanovesicles adorned with gripper ligands (aPD-L1 and aNKG2D) and encapsulated with colony-stimulating factor (CSF) for the treatment of haematologic malignancies. CSF@E-Hn targets the bone marrow and, thanks to the gripper ligands, pulls together tumour cells and natural killer cells, activating the latter for specific tumour cell targeting and elimination. The therapeutic efficacy was validated in mice bearing acute myeloid leukaemia and multiple myeloma. The comprehensive assessment of the post-treatment bone marrow microenvironment revealed that the integration of CSF into a bone-marrow-targeted nanosystem promoted haematopoietic stem cell differentiation, boosted memory T cell generation and maintained bone homoeostasis, with long-term prevention of relapse. Our nanosystem represents a promising strategy for the treatment of haematologic malignancies.