Natural Killer Cell Activity Research Articles

Payload-delivering engineered γδ T cells display enhanced cytotoxicity, persistence, and efficacy in preclinical models of osteosarcoma.

T cell-based cancer immunotherapy has typically relied on membrane-bound cytotoxicity enhancers such as chimeric antigen receptors expressed in autologous αβ T cells. These approaches are limited by tonic signaling of synthetic constructs and costs associated with manufacturing. γδ T cells are an emerging alternative for cellular therapy, having innate antitumor activity, potent antibody-dependent cellular cytotoxicity, and minimal alloreactivity. We present an immunotherapeutic platform technology built around the innate properties of the Vγ9Vδ2 T cell, harnessing specific characteristics of this cell type and offering an allocompatible cellular therapy that recruits bystander immunity. We engineered γδ T cells to secrete synthetic tumor-targeting opsonins in the form of an scFv-Fc fusion protein and a mitogenic IL-15Rα-IL-15 fusion protein (stIL15). Using GD2 as a model antigen, we show that GD2-specific opsonin-secreting Vγ9Vδ2 T cells (stIL15-OPS-γδ T cells) have enhanced cytotoxicity and promote bystander activity of other lymphoid and myeloid cells. Secretion of stIL-15 abrogated the need for exogenous cytokine supplementation and further mediated activation of bystander natural killer cells. Compared with unmodified γδ T cells, stIL15-OPS-γδ T cells exhibited superior in vivo control of subcutaneous tumors and persistence in the blood. Moreover, stIL15-OPS-γδ T cells were efficacious against patient-derived osteosarcomas in animal models and in vitro, where efficacy could be boosted with the addition of zoledronic acid. Together, the data identify stIL15-OPS-γδ T cells as a candidate allogeneic cell therapy platform combining direct cytolysis with bystander activation to promote tumor control.

Natural killer cells associate with epithelial cells in the pancreatic ductal adenocarcinoma tumor microenvironment.

Pancreatic ductal adenocarcinoma (PDAC) is the most common form of pancreatic cancer. PDAC's poor prognosis and resistance to immunotherapy are attributed in part to its dense, fibrotic tumor microenvironment (TME), which is known to inhibit immune cell infiltration. We recently demonstrated that PDAC patients with higher natural killer (NK) cell content and activation have better survival rates. However, NK cell interactions in the PDAC TME have yet to be deeply studied. We show here that NK cells are present and active in the human PDAC TME. We used imaging mass cytometry (IMC) to assess NK cell content, function, and spatial localization in human PDAC samples. Then, we used CellChat, a tool to infer ligand-receptor interactions, on a human PDAC scRNAseq dataset to further define NK cell interactions in PDAC. Spatial analyses showed for the first time that active NK cells are present in the PDAC TME, and both associate and interact with malignant epithelial cell ducts. We also found that fibroblast-rich, desmoplastic regions limit NK cell infiltration in the PDAC TME. CellChat analysis identified that the CD44 receptor on NK cells interacts with PDAC extracellular matrix (ECM) components such as collagen, fibronectin and laminin expressed by fibroblasts and malignant epithelial cells. This led us to hypothesize that these interactions play roles in regulating NK cell motility in desmoplastic PDAC TMEs. Using 2D and 3D in vitro assays, we found that CD44 neutralization significantly increased NK cell invasion through matrix. Targeting ECM-immune cell interactions may increase NK cell invasion into the PDAC TME.

Developing oxaliplatin and IL-15 Co-carried gels as drug depots to enable triple-interlocked combination therapy for colorectal cancer

Chemo-immunotherapy, which involves the simultaneous use of chemotherapy drug and immunotherapeutic agent to achieve synergistic effects, plays a crucial role in cancer treatment. However, the immunosuppressive microenvironment, insufficient tumor specificity, and serious systemic side effects hinder their synergistic therapeutic effects and clinical applications. Herein, T cell and natural killer (NK) cell, which are the most important immune effector cells, were both activated to reverse the immunosuppressive microenvironment. To simplify drug carriers, oxaliplatin was selected as the chemotherapy drug which can both induce the ICD effect and activate T cells. IL-15 was selected to activate NK cells. To enhance the productivity of the carrier and reduce side effects, the easy-prepared thermosensitive hydrogel (OXL/IL-15 TG) was developed to co-load oxaliplatin-loaded liposomes (OXL) and IL-15. Colorectal cancer, suitable for in situ administration, was selected as model cancer. The resulting novel triple-interlocked combination therapy could directly kill the tumor cells, induces ICD effect and activate NK cells. After administration, OXL/IL-15 TG was formed serving as a drug depot, slowing releasing OXL and IL-15 non-interferencely. OXL around 165.47±7.04 nm was passively delivered to tumor tissue, killing tumor cells and inducing ICD effect. The results demonstrated that IL-15 stimulated the activation of NK cells. In tumor-bearing mice models, OXL/IL-15 TG exhibited a remarkable and noteworthy anti-tumor efficacy, and expanded survival rate. Notably, OXL/IL-15 TG led to an enhanced infiltration of CD3+CD8+ T cells and CD3-CD49+ NK cells within the tumor tissue. Overall, the triple-interlocked combination therapy provided a new idea for colorectal cancer therapy.

The relationship between sleep and innate immunity.

Sleep regulates inflammatory responses, and the innate immune system affects sleep. Interleukin-1 beta, tumor necrosis factor alpha, growth hormone-releasing hormone, prolactin, and nitric oxide are somnogenic substances. Sleep deprivation, such as chronic insomnia or obstructive sleep apnea, affects cytokine production, glial function, natural killer cell activity, and inflammasome function. This review will discuss the relationship between sleep and innate immunity.

NK-cell receptor modulation in viral infections.

Natural killer (NK) cells play a crucial role in controlling viral infections. The ability to kill infected cells without prior immunization, yet being tolerant to self, healthy cells, depends on the balance of germ-line encoded surface receptors. NK-cell receptors are divided into either activating, leading to activation of NK cell and its cytotoxic and pro-inflammatory activity, or inhibitory, providing tolerance for a target cell. The signals from inhibitory receptors dominate and NK-cell activation requires stimulation of activating receptors. In viral infections, NK-cell interaction with infected cells can result in activation, memory-like NK-cell differentiation, or NK-cell exhaustion, which constitutes one of the viral immune evasion mechanisms. All of these states are associated with the modulation of NK-cell receptor expression. In this review, we summarize the current knowledge of NK-cell receptors and their role in viral infection control, as well as the alterations of their expression observed in acute or chronic infections. We present recently discovered SARS-CoV-2-mediated modulation of NK-cell receptor expression and compare them with other human viral infections. Finally, since modulation of NK-cell receptor activation gives a promising addition to currently used antiviral therapies, we briefly discuss the clinical significance and future perspective of the application of agonists or antagonists of activating and inhibitory receptors, respectively. In sum, our review shows that although much is known about NK-cell receptor biology, a deeper understanding of NK-cell receptors role in viral infections is still needed.

Abstract IA007: Tumor HLA-E expression and cytomegalovirus infection modulate NK cell activity in human bladder cancer

Abstract The intersection of viral infections and cancer therapy presents a complex landscape for immunotherapy strategies, particularly in solid tumors, where treatments such as systemic chemotherapy and targeted radiation are standard. Largely unexplored in solid tumors are the effects of human herpes virus-5 (HHV-5) also known as HCMV that imprints both lifelong effects on natural killer (NK) cells as well progressive effects on T cells with aging. HCMV is an extremely successful virus as it rarely kills the host outside of settings of compromised immunity, e.g. transplantation and advanced HIV-1 infection. HCMV is not considered a comorbidity in patients with solid tumors. Our group has identified reactivated cytomegalovirus (HCMV), found in bladder tissues post treatment, including infection of monocytes, fibroblasts, and even tumor cells, suggesting a viral influence that extends beyond traditional perspectives on cancer treatment resistance and response. We have observed spread of infection in both settings of BCG-treated non-muscle-invasive bladder cancer (NMIBC) as well as MIBC treated with gemcitabine and cisplatin chemotherapy. HCMV infection leads to the development of “adaptive” NK cells that express the activating isoform of NKG2A: NKG2C, which are likely expanded in response to HCMV reactivation and have established functions for controlling virus reactivation. Our central hypothesis is that certain treatments may reactivate HCMV, potentially greatly altering the biology within the tumor microenvironment (TME) and providing a framework to exploit NK cells for immunotherapy strategies. In a cohort of NMIBC patients (N=90) receiving BCG therapy at Mount Sinai, we profiled patients’ serum for HCMV-IgG (N=47 HCMV seropositive; N=43 HCMV seronegative) and observed a significantly improved recurrence-free survival in HCMV seropositive patients (HR=0.58, p=0.03). Further, HCMV-seropositive patients with circulating NKG2C+ adaptive NK cells experienced a near perfect response to BCG therapy (p=0.0002). Strikingly, in situ imaging and RNAscope analyses of patient tumors before and after BCG therapy revealed strong presence of active viremia in tumors. Further, analysis of on-treatment bladder biopsies after tumor resection demonstrated the presence of adaptive NK cells in HCMV+ bladder tissues, but only after exposure to BCG therapy and tissue-derived adaptive NK cells expressed high levels of chemokine receptors, CXCR3 and CXCR4 as well as tissue-residency markers, suggesting a mechanisms for trafficking to the bladder and taking up residence for subsequent antitumor control against recurrence. Impact and Translation: Our findings suggest that adaptive NK cells mediate response to immunotherapies for solid tumors as well as provide preclinical models for adoptive transfer therapies targeting NK cells. Additionally, if HCMV reactivation is widespread across solid tissues in response to systemic therapies, it may prove a critical comorbidity to consider in design of treatment strategies and in clinical trials. Citation Format: Amir Horowitz. Tumor HLA-E expression and cytomegalovirus infection modulate NK cell activity in human bladder cancer [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2024 May 17-20; Charlotte, NC. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(10_Suppl):Abstract nr IA007.

Mechanisms of myeloid-derived suppressor cell-mediated immunosuppression in colorectal cancer and related therapies.

Severe immunosuppression is a hallmark of colorectal cancer (CRC). Myeloid-derived suppressor cells (MDSCs), one of the most abundant components of the tumor stroma, play an important role in the invasion, metastasis, and immune escape of CRC. MDSCs create an immunosuppressive microenvironment by inhibiting the proliferation and activation of immunoreactive cells, including T and natural killer cells, as well as by inducing the proliferation of immunosuppressive cells, such as regulatory T cells and tumor-associated macrophages, which, in turn, promote the growth of cancer cells. Thus, MDSCs are key contributors to the emergence of an immunosuppressive microenvironment in CRC and play an important role in the breakdown of antitumor immunity. In this narrative review, we explore the mechanisms through which MDSCs contribute to the immunosuppressive microenvironment, the current therapeutic approaches and technologies targeting MDSCs, and the therapeutic potential of modulating MDSCs in CRC treatment. This study provides ideas and methods to enhance survival rates in patients with CRC.

Innate and Adaptive Immune Parameters following mRNA Vaccination in Mice.

The COVID-19 pandemic has raised the standard regarding the current vaccine development pace, as several messenger RNA (mRNA)-lipid nanoparticle (LNP) vaccines have proved their ability to induce strong immunogenicity and protective efficacy. We developed 1-methylpseudouridine-containing mRNA-LNP vaccines, expressing either the more conserved SARS-CoV-2 nucleoprotein (mRNA-N) or spike protein (mRNA-S), both based on the prototypic viral sequences. When combining both mRNA-S and mRNA-N together (mRNA-S+N), the vaccine showed high immunogenicity and broad protection against different SARS-CoV-2 variants, including wildtype, Delta, BA.1, BA.5, and BQ.1. To better understand the mechanisms behind this broad protection obtained by mRNA-S+N, we analyzed innate and adaptive immune parameters following vaccination in mice. Compared to either mRNA-S or mRNA-N alone, mice vaccinated with mRNA-S+N exhibited an increase in the innate immune response, as depicted by the higher cytokine (IL-6 and chemokine (MCP-1) levels. In addition, lymph node immunophenotyping showed the maturation and activation of dendritic cells and natural killer cells, respectively. To understand the adaptive immune response, RNA-Seq analyses of the lung and spleen samples of the vaccinated mice were performed in parallel and revealed a stronger immune gene-expression profile in the lung than that in the spleen. Compared to mRNA-S alone, mRNA-S+N vaccination elicited higher levels of expression for genes involved in multiple immune pathways, including T cells, cytokine signaling, antigen presentation, B cells, and innate immunity. Together, our studies provide immunological insights into the mechanisms of broad protection conferred by dual mRNA vaccination against SARS-CoV-2 variants.

Image-based assessment of natural killer cell activity against glioblastoma stem cells.

Glioblastoma (GBM) poses a significant challenge in oncology and stands as the most aggressive form of brain cancer. A primary contributor to its relentless nature is the stem-like cancer cells, called glioblastoma stem cells (GSCs). GSCs have the capacity for self-renewal and tumorigenesis, leading to frequent GBM recurrences and complicating treatment modalities. While natural killer (NK) cells exhibit potential in targeting and eliminating stem-like cancer cells, their efficacy within the GBM microenvironment is limited due to constrained infiltration and function. To address this limitation, novel investigations focusing on boosting NK cell activity against GSCs are imperative. This study presents two streamlined image-based assays assessing NK cell migration and cytotoxicity towards GSCs. It details protocols and explores the strengths and limitations of these methods. These assays could aid in identifying novel targets to enhance NK cell activity towards GSCs, facilitating the development of NK cell-based immunotherapy for improved GBM treatment.

Markers of hemophagocytic lymphohistiocytosis are associated with survival in critically ill patients

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): This work was supported by the Association for the Promotion of Research on Arteriosclerosis, Thrombosis and Vascular Biology (ATVB) and the Ludwig Boltzmann Cluster for Cardiovascular Research Background/Introduction Patients admitted to the intensive care unit (ICU) often show systemic immune dysregulation paired with significantly increased inflammatory activity. Haemophagocytic lymphohistiocytosis (HLH) represents a rare syndrome characterized by fever, inflammation, cytopenia, and organ dysfunction. Inappropriate survival of cytotoxic T cells as well as histiocytes triggers cytokine storm, accompanied by the occurrence of hemophagocytosis and multi-organ failure. prevalence of HLH in critical illness continues to be a topic of discussion but most certainly remains underreported. This circumstance often leads to delays in the necessary immunosuppressive therapy due to difficulty in early diagnosis. Purpose In the present study, we aimed to illuminate the prospective value of the individual HLH criteria in a cohort of critically ill patients. Although the prevalence of this syndrome might be low, isolated markers of HLH could help to assess the extent of inflammatory activation and further be of use in predicting the outcome of patients admitted to the ICU. Methods This was a prospective, observational cohort study. 176 consecutive patients admitted to a cardiac ICU were included over the course of one year. Available HLH criteria were recorded except for biopsy samples of bone marrow and measurements of low or absent natural killer cell activity. For soluble CD25 (sCD25) a specific ELISA kit was used according to the manufacturer's instructions. Results The median age was 67.51 years (IQR: 57.50-77.41) and 38.64% of the included patients were female. The total 30-day mortality was calculated to be 25.57% and positivity for two or more criteria of HLH was found to be associated with depicted mortality (p = 0.033). Analyzing the individual parameters, only sCD25 was found to be a predictor of death within the first 30 days (p < 0.001). The combination of triglycerides and fibrinogen did not predict outcomes. However, low fibrinogen values were found to possess prognostic merit in regard to mortality (p= 0.019). In multivariate analysis, both sCD25 and fibrinogen remained a significant predictor of 30-day survival after adjustment for age, sex, and BMI (sCD25 p < 0.001, fibrinogen p = 0.042). Finally, the addition of fibrinogen was able to improve the prognostic value of the SAPS II score significantly (ROC curve, SAPS II – AUC: 0.790, SAPS II & fibrinogen – AUC: 0.827, p = 0.045). Conclusion We provided evidence for the prognostic value of certain markers of HLH in critically ill patients. Positivity for two or more criteria was found to be associated with an increased 30-day mortality. Moreover, sCD25 and fibrinogen independently predicted outcomes in multivariate analysis after adjustment for age, sex, and BMI. The addition of fibrinogen was able to improve the prognostic properties of the SAPS II score.Figure 1Figure 2

Overexpressing S100A9 ameliorates NK cell dysfunction in estrogen receptor-positive breast cancer

BackgroundEstrogen receptor (ER) positive human epidermal growth factor receptor 2 (HER2) negative breast cancer (ER+/HER2−BC) and triple-negative breast cancer (TNBC) are two distinct breast cancer molecular subtypes, especially in tumor immune microenvironment (TIME). The TIME of TNBC is considered to be more inflammatory than that of ER+/HER2−BC. Natural killer (NK) cells are innate lymphocytes that play an important role of tumor eradication in TME. However, studies focusing on the different cell states of NK cells in breast cancer subtypes are still inadequate.MethodsIn this study, single-cell mRNA sequencing (scRNA-seq) and bulk mRNA sequencing data from ER+/HER2−BC and TNBC were analyzed. Key regulator of NK cell suppression in ER+/HER2−BC, S100A9, was quantified by qPCR and ELISA in MCF-7, T47D, MDA-MB-468 and MDA-MB-231 cell lines. The prognosis predictability of S100A9 and NK activation markers was evaluated by Kaplan–Meier analyses using TCGA-BRAC data. The phenotype changes of NK cells in ER+/HER2−BC after overexpressing S100A9 in cancer cells were evaluated by the production levels of IFN-gamma, perforin and granzyme B and cytotoxicity assay.ResultsBy analyzing scRNA-seq data, we found that multiple genes involved in cellular stress response were upregulated in ER+/HER2−BC compared with TNBC. Moreover, TLR regulation pathway was significantly enriched using differentially expressed genes (DEGs) from comparing the transcriptome data of ER+/HER2−BC and TNBC cancer cells, and NK cell infiltration high/low groups. Among the DEGs, S100A9 was identified as a key regulator. Patients with higher expression levels of S100A9 and NK cell activation markers had better overall survival. Furthermore, we proved that overexpression of S100A9 in ER+/HER2-cells could improve cocultured NK cell function.ConclusionIn conclusion, the study we presented demonstrated that NK cells in ER+/HER2−BC were hypofunctional, and S100A9 was an important regulator of NK cell function in ER+BC. Our work contributes to elucidate the regulatory networks between cancer cells and NK cells and may provide theoretical basis for novel drug development.

Immune-Enhancing Activity of Vitis coignetiae Extract via Increasing Cytokine and Natural Killer Cell Activity in Splenocytes and Cyclophosphamide-Induced Immunosuppressed Rats

Plant and fruit extracts exhibit fewer side effects than pharmaceuticals and can display therapeutic qualities. Consequently, they have attracted increased attention among health-conscious individuals, and many studies related to their health-promoting effects are being actively conducted. Vitis coignetiae is well-known for its antioxidant, anti-inflammatory, and anticancer properties. However, the immune-enhancing effects of Vitis coignetiae have not yet been studied. In this study, Vitis coignetiae extract (VCE) increased immune-related activity in Wistar rat splenocytes and cyclophosphamide (Cy)-induced immunosuppressed rats. In splenocytes, VCE was nontoxic up to 300 μg/mL and increased cell viability in the presence of Cy. VCE also recovered Cy-induced decreases in cytokine (tumor necrosis factor alpha (TNF-α), interferon gamma (IFN-γ), interleukin-2 (IL-2), and IL-12) levels and natural killer (NK) cell activity in splenocytes. In Cy-induced immunosuppressed rats, VCE protected against Cy-induced spleen tissue damage and decreases in body and spleen weight, cytokine (TNF-α, IFN-γ, IL-2, and IL-12) levels, and NK cell activity. We also observed recovery of immunoglobulin G (IgG) and IgM levels following VCE treatment. In conclusion, the ability of VCE to restore immune activity from an immunosuppressive state to normal levels suggests its immune-enhancing efficacy. Therefore, VCE may have the potential for application in the development of immune-enhancing functional foods and medicines.

Immunotherapeutic hydrogel for co-delivery of STAT3 siRNA liposomes and lidocaine hydrochloride for postoperative comprehensive management of NSCLC in a single application

Despite standard treatment for non-small cell lung cancer (NSCLC) being surgical resection, cancer recurrence and complications, such as induction of malignant pleural effusion (MPE) and significant postoperative pain, usually result in treatment failure. In this study, an alginate-based hybrid hydrogel (SOG) is developed that can be injected into the resection surface of the lungs during surgery. Briefly, endoplasmic reticulum-modified liposomes (MSLs) pre-loaded with the signal transducer and activator of transcription 3 (STAT3) small interfering RNA and lidocaine hydrochloride are encapsulated in SOG. Once applied, MSLs strongly downregulated STAT3 expression in the tumor microenvironment, resulting in the apoptosis of lung cancer cells and polarization of tumor-associated macrophages towards the M1-like phenotype. Meanwhile, the release of lidocaine hydrochloride (LID) was beneficial for pain relief and natural killer cell activation. Our data demonstrated MSL@LID@SOG not only efficiently inhibited tumor growth but also potently improved the quality of life, including reduced MPE volume and pain relief in orthotopic NSCLC mouse models, even with a single administration. MSL@LID@SOG shows potential for comprehensive clinical management upon tumor resection in NSCLC, and may alter the treatment paradigms for other cancers.

Integrative multi-omics profiling in human decedents receiving pig heart xenografts.

In a previous study, heart xenografts from 10-gene-edited pigs transplanted into two human decedents did not show evidence of acute-onset cellular- or antibody-mediated rejection. Here, to better understand the detailed molecular landscape following xenotransplantation, we carried out bulk and single-cell transcriptomics, lipidomics, proteomics and metabolomics on blood samples obtained from the transplanted decedents every 6 h, as well as histological and transcriptomic tissue profiling. We observed substantial early immune responses in peripheral blood mononuclear cells and xenograft tissue obtained from decedent 1 (male), associated with downstream T cell and natural killer cell activity. Longitudinal analyses indicated the presence of ischemia reperfusion injury, exacerbated by inadequate immunosuppression of T cells, consistent with previous findings of perioperative cardiac xenograft dysfunction in pig-to-nonhuman primate studies. Moreover, at 42 h after transplantation, substantial alterations in cellular metabolism and liver-damage pathways occurred, correlating with profound organ-wide physiological dysfunction. By contrast, relatively minor changes in RNA, protein, lipid and metabolism profiles were observed in decedent 2 (female) as compared to decedent 1. Overall, these multi-omics analyses delineate distinct responses to cardiac xenotransplantation in the two human decedents and reveal new insights into early molecular and immune responses after xenotransplantation. These findings may aid in the development of targeted therapeutic approaches to limit ischemia reperfusion injury-related phenotypes and improve outcomes.

Pancreatic Cancer: A Review on Pathophysiology, Naturopathy, Clinical Treatment and Outcomes

Abstract: The study aimed to comprehend the molecular mechanisms and pathophysiology of pancreatic cancer with an emphasis on the advances in treatment options and the use of natural products as anticancer agents. The study involved a literature survey using PubMed, Web of Science and Google scholar database. The literature search was done using keywords “Pancreatic cancer”, “Chemotherapy”, “Mutations”, and “Natural compounds”. 266 articles were studied of which 201 were taken into consideration based on relevance to the topic. Pancreatic cancer is associated with mutations of CDKN2A (encoding p16), KRAS, TP53 and SMAD4. MAPK, PI3K-AKT, and TGF- β pathway dysfunction also led to pancreatic cancer. Current clinical trial activities in pancreatic cancer target angiogenesis, surface receptors, cell cycle, DNA damage response, etc. Studies have shown that combining surgical resection with adjuvant chemotherapy increases survival rates in patients. New treatment options are on the rise for this cancer type, which is perioperative or neo-adjuvant therapy. Gemcitabine as a single treatment agent in pancreatic cancer has shown promising response with chemotherapy regimens using two combinations- Folfirinox and Gemcitabine/Nab-Paclitaxel giving a better response rate. Numerous natural substances, including curcumin, aloe vera, and taxol, which suppress oxidative stress, angiogenesis, JAK2 STAT3 pathways, and enhanced natural killer cell activity, have been explored as potential treatments for pancreatic cancer. With pancreatic cancer having a poor prognosis, investigations to comprehend its molecular underpinnings and research on natural chemicals could lead to the development of safer treatment alternatives with enhanced survival rates for pancreatic cancer patients.

Therapeutic Inducers of Natural Killer cell Killing (ThINKK): preclinical assessment of safety and efficacy in allogeneic hematopoietic stem cell transplant settings

BackgroundAllogeneic hematopoietic stem cell transplantation (HSCT) remains the standard of care for chemotherapy-refractory leukemia patients, but cure rates are still dismal. To prevent leukemia relapse following HSCT, we aim to...

Membrane Fluctuation Model for Understanding the Effect of Receptor Nanoclustering on the Activation of Natural Killer Cells through Biomechanical Feedback.

We investigated the role of ligand clustering and density in the activation of natural killer (NK) cells. To that end, we designed reductionist arrays of nanopatterned ligands arranged with different cluster geometries and densities and probed their effects on NK cell activation. We used these arrays as an artificial microenvironment for the stimulation of NK cells and studied the effect of the array geometry on the NK cell immune response. We found that ligand density significantly regulated NK cell activation while ligand clustering had an impact only at a specific density threshold. We also rationalized these findings by introducing a theoretical membrane fluctuation model that considers biomechanical feedback between ligand-receptor bonds and the cell membrane. These findings provide important insight into NK cell mechanobiology, which is fundamentally important and essential for designing immunotherapeutic strategies targeting cancer.

Effect of Heat-Treated Lactiplantibacillus plantarum nF1 on the Immune System Including Natural Killer Cell Activity: A Randomized, Placebo-Controlled, Double-Blind Study.

Heat-treated Lactiplantibacillus plantarum nF1 (HT-nF1) increases immune cell activation and the production of various immunomodulators (e.g., interleukin (IL)-12) as well as immunoglobulin (Ig) G, which plays an important role in humoral immunity, and IgA, which activates mucosal immunity. To determine the effect of HT-nF1 intake on improving immune function, a randomized, double-blind, placebo-controlled study was conducted on 100 subjects with normal white blood cell counts. The HT-nF1 group was administered capsules containing 5 × 1011 cells of HT-nF1 once a day for 8 weeks. After 8 weeks of HT-nF1 intake, significant changes in IL-12 were observed in the HT-nF1 group (p = 0.045). In particular, the change in natural killer (NK) cell activity significantly increased in subjects with low secretory (s) IgA (≤49.61 μg/mL) and low NK activity (E:T = 10:1) (≤3.59%). These results suggest that HT-nF1 has no safety issues and improves the innate immune function by regulating T helper (Th)1-related immune factors. Therefore, we confirmed that HT-nF1 not only has a positive effect on regulating the body's immunity, but it is also a safe material for the human body, which confirms its potential as a functional health food ingredient.

Combined mild magnetic hyperthermia and calcium ion regulation for enhanced immunotherapy of orthotopic liver cancer

Cancer immunotherapy relies on immune cells activation to fight malignancies. Liver serves as the important organs with abundant immune cells. However, in the process of liver tumor development, immune cells lose original function of fighting tumors affected by tumor immunosuppressive microenvironment. Here, a hyaluronic acid-modified calcium phosphate-coated magnetic nanoparticles (named as MSCH) is used to remodel immunosuppressive microenvironment of liver tumors to multiple activate immune cells based on mild magnetic hyperthermia therapy (MHT) and calcium ions regulation strategy. In detail, intra-tumoral acidic microenvironment and mild MHT effectively promote calcium ions release from MSCH to activate casepase-1, resulting in tumor-associated macrophages (TAMs) M1 polarization. Meanwhile, mild MHT significantly upregulate RAE-1ɛ proteins expression in liver cancer cells, ligands for natural killer group 2 member D (NKG2D), resulting in natural killer (NK) cell activation. Moreover, the synergistic effect of mild MHT and calcium overload in cancer cells enables tumor immunogenic cell death (ICD) to activate robust adaptive immune responses. Most importantly, the mild MHT featuring excellent deep tissue penetration ensures the heat accumulation in liver tumors. The multi-activated immune cells therapy strategy based on mild MHT and calcium ions regulation has demonstrated excellent therapeutic effects for orthotopic liver cancer tumor.

Augmentation of NK-cell activity and immunity by combined natural polyphenols and saccharides in vitro and in vivo

Curcuma longa and Sargassum coreanum are commonly used in traditional pharmaceutical medicine to improve immune function in chronic diseases. The present study was designed to systematically elucidate the in vitro and in vivo immuno-enhancing effects of a combination of C. longa and S. coreanum extracts (CS) that contain polyphenols and saccharides as functional molecules in a cyclophosphamide (Cy)-induced model of immunosuppression. In primary splenocytes, we observed the ameliorative effects of CS on a Cy-induced immunosuppression model with low cytotoxicity and an optimal mixture procedure. CS treatment enhanced T- and B-cell proliferation, increased splenic natural killer-cell activity, and restored cytokine release. Wistar rats were orally administered low (30 mg/kg), intermediate (100 mg/kg), or high (300 mg/kg) doses of CS for four weeks, followed by oral administration of Cy (5 mg/kg) for four weeks. Compared with the vehicle group, low-, intermediate-, and high-dose CS treatment accelerated dose-dependent recovery of the serum level of tumor necrosis factor-α, interferon-γ, interleukin-2, and interleukin-12. These results suggest that CS treatment accelerates the amelioration of immune deficiency in Cy-treated primary splenocytes and rats, which supports considering it for immunity maintenance. Our findings provide experimental evidence for further research and clinical application in immunosuppressed patients.