IL-12 regulates the expansion, phenotype, and function of murine NK cells activated by IL-15 and IL-18

GATA1-mediated Notch signaling augment antitumor immunity of CD11b+CD27- natural killer cells maturation via BCL9/β-catenin signal

The maturation process of natural killer (NK) cells is integral to their antitumor immune response. Despite the diverse effector properties exhibited during differentiation, targeting the fate of NK cells for immunotherapy remains challenging. Here, we demonstrate that deficiency of B cell lymphoma 9 (BCL9) induces transient expression of GATA1 in CD11b+ CD27- NK cells upon activation of Notch and interleukin-18 receptor 1 (IL-18R1) signaling, which are crucial for their maturation and antitumor activity. Conversely, blocking Notch signaling impairs NK cell development and antitumor function. NK-specific Bcl9-deficiency enhances B16F10 tumor killing in vivo. Our findings underscore the intricate network interactions among transcription factors, signal transduction pathways in development, and cytokines modulated by BCL9 deficiency. Targeting BCL9 emerges as a promising strategy for melanoma therapy, bolstering NK cell maturation and cytotoxicity, and overcoming challenges in NK cell-based immunotherapies.

Mediation Mendelian randomization analysis of immune cell phenotypes and glioma risk: unveiling the regulation of cerebrospinal fluid metabolites

BACKGROUND AND OBJECTIVE

Gliomas, particularly glioblastoma multiforme (GBM), are the most common primary central nervous system tumors in adults and are notoriously difficult to treat due to their high heterogeneity and invasiveness. Despite advances in molecular diagnostics and personalized therapies, prognosis remains poor. The immune system plays a critical role in glioma progression. This study employed mediation Mendelian randomization analysis to explore the relationships between immune cell phenotypes, cerebrospinal fluid metabolites, and glioma, aiming to uncover potential mechanisms of tumor progression and immune evasion.

METHOD

In this study, we employed several analytical methods including IVW, MR Egger, Simple mode, Weighted median, and Weighted mode, with IVW results being considered the primary basis. We assessed heterogeneity and pleiotropy, and used leave-one-out analysis to determine sensitivity, ensuring the stability and reliability of the results. The potential mediating effects of cerebrospinal fluid metabolites were investigated to explore the underlying mechanisms linking immune cell function and glioma. The GWAS data for immune cells, cerebrospinal fluid metabolites, and glioma used in this study were sourced from public databases.

RESULT

We identified nine risk immune cell phenotypes for glioma (such as CD19 on IgD( +) CD24(-)), and ten protective immune cell phenotypes (such as CD11c on monocytes). Mediation analysis revealed that levels of 7-alpha-hydroxy-3-oxo-4-cholestenoate (7-hoca) (MP = - 14.6%) and Palmitoyl dihydrosphingomyelin (d18:0/16:0) (MP = 7.9%) partially mediated the relationship between CD3 on CD39( +) resting Treg cells and glioma. Additionally, 7-hoca levels (MP = - 12.3%) and Phenyllactate (pla) levels (MP = 4.12%) partially mediated the association between FSC-A on NKT cells and glioma. Furthermore, Glycerophosphoinositol levels (MP = - 12.1%) and Orotate levels (MP = - 11.4%) partially mediated the relationship between Granulocyte adenylyl cyclase (Granulocyte AC) and glioma.

CONCLUSION

This study identified that specific immune cell phenotypes directly influence glioma risk and indirectly modulate this risk through cerebrospinal fluid metabolites. CD19 on IgD( +) CD24(-) B cells were identified as risk factors, while CD11c on monocytes were protective. Metabolites like 7-hoca and glycerophosphoinositol play key mediating roles. These findings enhance our understanding of glioma pathophysiology and suggest that immune modulation and metabolic intervention may be promising therapeutic strategies.

Antifibrotic effects of IL-12-treated natural killer cells on collagen type I regulation in lung fibroblasts

Idiopathic pulmonary fibrosis is a chronic fibrotic lung disease with limited treatment options, making the development of new therapies crucial. We previously demonstrated that γδ T cells, a subset of immune effector cells, exhibit antifibrotic properties. We have also shown that natural killer (NK) cells, another class of immune effectors, can be efficiently expanded in culture using interleukin-2 (IL-2) and interleukin-18 (IL-18). This study examined the effects of interleukin-12 (IL-12)-stimulated NK cells, expanded with IL-2 and IL-18, on type I collagen and α-smooth muscle actin (αSMA) expression in pulmonary fibroblasts. IL-12-stimulated human NK cells exhibited reduced cytotoxicity toward pulmonary fibroblasts while retaining their proliferative capacity. Co-culture of IL-12-stimulated NK cells with fibroblasts significantly suppressed type I collagen and αSMA expression, even without direct cell contact, indicating the involvement of soluble factors. Supernatants from IL-12-stimulated NK cells partially inhibited the expression of these antifibrotic factors, suggesting a dual mechanism: direct cell-cell interaction and soluble factor secretion. Interferon-γ (IFN-γ) in the supernatant significantly increased, and neutralizing anti-IFN-γ monoclonal antibody partially reversed type I collagen and αSMA suppression. Similarly, IL-12-stimulated murine NK cells suppressed type I collagen in mouse pulmonary fibroblasts. These findings suggest that IL-12-stimulated NK cells inhibit the expression of fibrosis-associated molecules via contact-dependent and -independent mechanisms, supporting their potential for adoptive cell therapy in pulmonary fibrosis.

The Practical Landscape of Cytokine-Targeted miRNAs to Enhance NK Cell Function in Cancer Immunotherapy: A Bioinformatic Analysis

INTRODUCTION

Suppression within the tumor microenvironment (TME) hampered natural killer (NK) cells and their role in cancer immunotherapy. This study explores how interleukin (IL) signaling (IL-12A, IL-12B, IL-15, IL-18) and interferon gamma (IFNG or IFN-γ) interact with microRNAs to regulate NK cell function in cancer.

METHODS

We identify the targeted microRNAs (miRNAs) for these genes and the key pathways influencing various cancers through comprehensive analyses, including protein-protein interaction networks, protein co-expression, miRNA targeting prediction, homology, mRNA-miRNA regulatory networks, gene set enrichment, and signaling pathway analysis.

RESULTS

Our analysis revealed a significant association between genes encoding interleukins and IFNG with NK cell infiltration across various cancers. Additionally, we identified several miRNAs (hsa-miR-590-3p, hsa-miR-340-5p, hsa-miR-495-3p, hsa-miR-5692a, hsa-miR-130a-3p) that potentially regulate NK cell function by targeting these genes. These miRNAs participate in critical pathways essential for NK cell function. Notably, our findings suggest a key role for mRNA-miRNA co-regulation in suppressing NK cells within the tumor microenvironment.

CONCLUSION

This study highlights the potential of targeting these identified miRNAs as a strategy to enhance NK cell function and improve the efficacy of cancer immunotherapy.

Single cell profiling of hematopoietic stem cell transplant recipients reveals TGF-β1 and IL-2 confer immunoregulatory functions to NK cells

Natural killer (NK) cell activity is influenced by cytokines and microenvironment factors, resulting in remarkably diverse functions, by contributing to inflammatory responses or serving as rheostats of adaptive immunity. Using single cell RNA sequencing (scRNA-seq), we identified a TGFβ1 highCD56brightNK cell population associated with hematopoietic stem cell transplant recipients protected from acute graft-versus-host disease (GVHD). We further define a role for the combination of interleukin-2 (IL-2) and transforming growth factor β1 (TGF-β1) in promoting a regulatory phenotype in NK cells. "Induced" regulatory NK cells produce high amounts of TGF-β1, inhibited T cells, could promote naive T cells differentiation into regulatory T cells, and exhibited a unique transcriptional program that includes expression of IKZF2 (HELIOS) and ZNF683 (HOBIT). This phenotype was not stable, and "induced" regulatory NK cells lost the ability to secrete TGF-β1 upon exposure to different cytokines. These findings define protective CD56brightNK cells post-hematopoietic stem cell transplantation, and demonstrate the combination of IL-2 and TGF-β1 promotes regulatory activity in NK cells.

Therapeutic potential of trained immunity for malignant disease

Trained immunity (TI) is functional memory displayed by innate immune cells (IICs). TI facilitates rapid, non-specific responses to pathogens upon secondary challenge. It is driven by immunological signaling and metabolic rewriting via epigenetic alteration, triggered by recognition of certain stimuli. Recently, immune checkpoint inhibitors have come into common use in clinical oncology settings, and genetically engineered cytotoxic T cells comprise a potent cancer treatment strategy. However, the contributions of TI in the tumor microenvironment (TME) are only beginning to be uncovered. Accumulating evidence that various microorganisms and vaccines convey tumoricidal ability suggest that TI may become a useful anti-cancer tool. The expected roles of TI in tumor therapy are the 1) promotion of proinflammatory cytokine section, 2) enhancement of phagocytosis, 3) quick expansion and recruitment of cancer-specific cytotoxic T cells to the TME through neoantigen presentation, 4) reversal of immunosuppression in the TME, and 5) removal of pathogens associated with carcinogenesis or tumor development. Medium- to long-term TI durability may reduce the risk of tumor development. Recent findings on TI usher in new aspirations for cancer treatment.

The effects of oral nutritional supplements on endometriosis-related pain: A narrative review of clinical studies

Endometriosis is a condition that can cause significant pain and discomfort for women, and the clinical and surgical treatments available have variable efficacy and can have adverse effects. These drawbacks often lead to poor adherence and therapeutic failure. Consequently, there has been increasing interest in the use of nutritional supplements as an adjuvant therapy for endometriosis. To facilitate clinical decision-making in managing women with endometriosis, a narrative review of clinical studies was conducted to investigate the effects of oral nutritional supplements on endometriosis-related pain. A literature search of the English-language PubMed/MEDLINE database was performed using appropriate keywords to identify clinical studies involving oral nutritional supplements and reporting on endometriosis-related pain. This narrative review included 20 studies published between 2013 and 2023, comprising 12 randomized controlled trials, six non-comparative trials, and two observational studies. The studies investigated the effects of various nutritional supplements on endometriosis-related pain, including vitamins, fatty acids, probiotics, medicinal plants, and bioactive compounds. A significant decrease in endometriosis-related pain was found in three out of five studies on vitamins, four out of six studies on fatty acids, one study on probiotics, two studies on medicinal plants, and five out of six studies on bioactive compounds. These nutritional supplements exhibited diverse biological activities, such as anti-inflammatory, antioxidant, antiproliferative, and antiangiogenic effects, all of which are relevant for managing endometriosis. These findings suggest that oral nutritional supplements could be included as part of a multidisciplinary treatment for endometriosis to decrease pain and enhance overall medical treatment.

Targeting hypoxia-inducible factor 1 alpha augments synergistic effects of chemo/immunotherapy via modulating tumor microenvironment in a breast cancer mouse model

Introduction

The immunosuppressive context of the tumor microenvironment (TME) is a significant hurdle in breast cancer (BC) treatment. Combinational therapies targeting cancer core signaling pathways involved in the induction of TME immunosuppressive milieu have emerged as a potent strategy to overcome immunosuppression in TME and enhance patient therapeutic outcomes. This study presents compelling evidence that targeting hypoxia-inducible-factor-1 alpha (Hif-1α) alongside chemotherapy and immune-inducing factors leads to substantial anticancer effects through modulation of TME.

Methods

Chitosan (Cs)/Hif-1alpha siRNA nano-complex was synthesized by siRNA adsorption methods. Nanoparticles were fully characterized using dynamic light scattering and scanning electron microscope. Cs/Hif-1α siRNA cytotoxicity was measured by MTT assay. The anticancer effects of the combinational therapy were assessed in BALB/c bearing 4T1 tumors. qPCR and western blotting were applied to assess the expression of some key genes and proteins involved in the induction of immunosuppression in TME.

Results

Hif-1α siRNA was successfully loaded in chitosan nanoparticles. Hif-1α siRNA nanocomplexes significantly inhibited the expression of Hif-1α. Triple combination therapy (Paclitaxel (Ptx) + Imiquimod (Imq) + Cs/Hif-1α siRNA) inhibited tumor growth and downregulated cancer progression genes while upregulating cellular-immune-related cytokines. Mice without Cs/Hif-1α siRNA treatments revealed fewer cancer inhibitory effects and more TME immunosuppressive factors. These results suggest that the inhibition of Hif-1α effects synergize with Ptx and Imq to inhibit cancer progression more significantly than other combinational treatments.

Conclusion

Combining Hif-1α siRNA with Ptx and Imq is promising as a multimodality treatment. It has the potential to attenuate TME inhibitory effects and significantly enhance the immune system's ability to combat tumor cell growth, offering an inspiration of hope in the fight against BC.

The Role of Natural Killer Cells in Oncolytic Virotherapy: Friends or Foes?

Oncolytic virotherapy (OVT) has emerged as a promising cancer immunotherapy, and is capable of potentiating other immunotherapies due to its capacity to increase tumor immunogenicity and to boost host antitumor immunity. Natural killer (NK) cells are a critical cellular component for mediating the antitumor response, but hold a mixed reputation for their role in mediating the therapeutic efficacy of OVT. This review will discuss the pros and cons of how NK cells impact OVT, and how to harness this knowledge for the development of effective strategies that could modulate NK cells to improve OVT-based therapeutic outcomes.

BCG priming followed by a novel interleukin combination activates Natural Killer cells to selectively proliferate and become anti-tumour long-lived effectors

The short-lived nature and heterogeneity of Natural Killer (NK) cells limit the development of NK cell-based therapies, despite their proven safety and efficacy against cancer. Here, we describe the biological basis, detailed phenotype and function of long-lived anti-tumour human NK cells (CD56highCD16+), obtained without cell sorting or feeder cells, after priming of peripheral blood cells with Bacillus Calmette-Guérin (BCG). Further, we demonstrate that survival doses of a cytokine combination, excluding IL18, administered just weekly to BCG-primed NK cells avoids innate lymphocyte exhaustion and leads to specific long-term proliferation of innate cells that exert potent cytotoxic function against a broad range of solid tumours, mainly through NKG2D. Strikingly, a NKG2C+CD57-FcεRIγ+ NK cell population expands after BCG and cytokine stimulation, independently of HCMV serology. This strategy was exploited to rescue anti-tumour NK cells even from the suppressor environment of cancer patients' bone marrow, demonstrating that BCG confers durable anti-tumour features to NK cells.

The role of CD56bright NK cells in neurodegenerative disorders

Emerging evidence suggests a potential role for natural killer (NK) cells in neurodegenerative diseases, such as multiple sclerosis, Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis. However, the precise function of NK cells in these diseases remains ambiguous. The existence of two NK cell subsets, CD56bright and CD56dim NK cells, complicates the understanding of the contribution of NK cells in neurodegeneration as their functions within the context of neurodegenerative diseases may differ significantly. CD56bright NK cells are potent cytokine secretors and are considered more immunoregulatory and less terminally differentiated than their mostly cytotoxic CD56dim counterparts. Hence, this review focusses on NK cells, specifically on CD56bright NK cells, and their role in neurodegenerative diseases. Moreover, it explores the mechanisms underlying their ability to enter the central nervous system. By consolidating current knowledge, we aim to provide a comprehensive overview on the role of CD56bright NK cells in neurodegenerative diseases. Elucidating their impact on neurodegeneration may have implications for future therapeutic interventions, potentially ameliorating disease pathogenesis.

Mechanism of Qizhen decoction-mediated maturation of DC cells to activate the IL-12/JAK2/STAT4 pathway to sensitise PD-1 inhibitors in the treatment of colorectal cancer

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese medicine has been utilized to treat colorectal cancer (CRC). Qizhen decoction (QZD), a potential compound prescription of traditional Chinese medicine, possesses multiple biological activities. It has been used to treat CRC in clinical practice and has been proven to be effective.

AIM OF THE STUDY

To investigate the impact of QZD supported by intestinal flora in combination with PD-1 inhibitor on colorectal cancer, and to elucidate the mechanism by which QZD enhances the sensitivity of PD-1 inhibitor against colorectal cancer.

MATERIALS AND METHODS

Observation of Intestinal Flora Mediating the Effect of QZD Combined with PD-1 Inhibitor in the Treatment of Colorectal Cancer. We used Flow cytometry and qPCR to detect the effect of QZD combined with PD-1 inhibitor on the activation of effector T cells in a wild mouse model of colorectal cancer. In wild and germ-free mouse models, the differences in inflammatory factors, pathological change, body mass, colorectal length, and tumour load were observed. In the study of the mechanism of QZD combined with PD-1 inhibitor in the treatment of colorectal cancer, the study evaluated the abundance of Akkermansia, the phenotypes of effector T cells and DC cells, as well as inflammatory factors in each group of mice to determine whether Akkermansia played a role in activating DC cells. Based on the JAK2/TYK2/STAT4 pathway, the mechanism of PD-1 inhibitor sensitisation by QZD in colorectal cancer was further investigated.

RESULTS

We found that QZD combined with PD-1 inhibitor could improve the therapeutic effect on colorectal cancer by inducing more critical immune functions. QZD promotes increased Akkermansia abundance in the gut. Akkermansia promotes maturation of DC cells, and mature DC cells activate the IL-12/JAK2/STAT4 pathway, which significantly activates effector T cells. Akkermansia is key to QZD combined with PD-1 inhibitor-mediated immunity exerting a therapeutic effect on colorectal cancer.

CONCLUSION

The mechanism of action of the QZD sensitizing PD-1 inhibitor is to promote the maturation of DC cells to release IL-12 and activate the JAK2/STAT4 pathway to induce effector T cell activation by increasing the abundance of Akkermansia.

Natural killer cell-mediated immune surveillance in cancer: Role of tumor microenvironment

In the immunological surveillance against cancer, natural killer (NK) cells are essential effectors that help eradicate altered cells. The complex interactions that occur between NK cells and the tumor microenvironment (TME) are thoroughly examined in this review. The review examines how cytokine stimulation affects NK cell activation, focusing on the dynamic modulation of NK cell function within the TME. It looks at NK cell-related biomarkers such as PD-1/PD-L1, methylation HOXA9 (Homeobox A9), Stroma AReactive Invasion Front Areas (SARIFA), and NKG2A/HLA-E, providing critical information about prognosis and treatment outcomes. The changing landscape of immunotherapies-including checkpoint inhibitors, CAR-NK cells, and cytokine-based interventions-is examined in the context of enhancing NK cell activity. The review highlights the potential pathways for precision medicine going forward, focusing on customized immunotherapies based on unique biomarker profiles and investigating combination medicines to produce more robust anti-tumor responses.

Molecular Mechanisms of IL18 in Disease

Interleukin 18 (IL18) was originally identified as an inflammation-induced cytokine that is secreted by immune cells. An increasing number of studies have focused on its non-immunological functions, with demonstrated functions for IL18 in energy homeostasis and neural stability. IL18 is reportedly required for lipid metabolism in the liver and brown adipose tissue. Furthermore, IL18 (Il18) deficiency in mice leads to mitochondrial dysfunction in hippocampal cells, resulting in depressive-like symptoms and cognitive impairment. Microarray analyses of Il18-/- mice have revealed a set of genes with differential expression in liver, brown adipose tissue, and brain; however, the impact of IL18 deficiency in these tissues remains uncertain. In this review article, we discuss these genes, with a focus on their relationships with the phenotypic disease traits of Il18-/- mice.

Functional integration of natural killer cells in a microfluidically perfused liver on-a-chip model

OBJECTIVE

The liver acts as an innate immunity-dominant organ and natural killer (NK) cells, are the main lymphocyte population in the human liver. NK cells are in close interaction with other immune cells, acting as the first line of defense against pathogens, infections, and injury. A previously developed, three-dimensional, perfused liver-on-a-chip comprised of human cells was used to integrate NK cells, representing pivotal immune cells during liver injury and regeneration. The objective of this study was to integrate functional NK cells in an in vitro model of the human liver and assess utilization of the model for NK cell-dependent studies of liver inflammation.

RESULTS

NK cells from human blood and liver specimen were isolated by Percoll separation with subsequent magnetic cell separation (MACS), yielding highly purified blood and liver derived NK cells. After stimulation with toll-like-receptor (TLR) agonists (lipopolysaccharides, Pam3CSK4), isolated NK cells showed increased interferon (IFN)-gamma secretion. To study the role of NK cells in a complex hepatic environment, these cells were integrated in the vascular compartment of a microfluidically supported liver-on-a-chip model in close interaction with endothelial and resident macrophages. Successful, functional integration of NK cells was verified by immunofluorescence staining (NKp46), flow cytometry analysis and TLR agonist-dependent secretion of interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha. Lastly, we observed that inflammatory activation of NK cells in the liver-on-a-chip led to a loss of vascular barrier integrity. Overall, our data shows the first successful, functional integration of NK cells in a liver-on-a-chip model that can be utilized to investigate NK cell-dependent effects on liver inflammation in vitro.

Tumor-Infiltrating iNKT Cells Activated through c-Kit/Sca-1 Are Induced by Pentoxifylline, Norcantharidin, and Their Mixtures for Killing Murine Melanoma Cells

The involvement of NK and other cytotoxic cells is considered the first defense line against cancer. However, a significant lack of information prevails on the possible roles played by factors considered characteristic of primitive cells, such as c-kit and Sca-1, in activating these cells, particularly in melanoma models subjected to treatments with substances under investigation, such as the case of norcantharidin. In this study, B16F1 murine melanoma cells were used to induce tumors in DBA/2 mice, estimating the proportions of NK and iNKT cells; the presence of activation (CD107a+) and primitive/activation (c-kit+/Lya6A+) markers and some tumor parameters, such as the presence of mitotic bodies, nuclear factor area, NK and iNKT cell infiltration in the tumor, infiltrated tumor area, and infiltrating lymphocyte count at 10x and 40x in specimens treated with pentoxifylline, norcantharidin, and the combination of both drugs. Possible correlations were estimated with Pearson's correlation analysis. It should be noted that, despite having demonstrated multiple correlations, immaturity/activation markers were related to these cells' activation. At the tumor site, iNKT cells are the ones that exert the cytotoxic potential on tumor cells, but they are confined to specific sites in the tumor. Due to the higher number of interactions of natural killer cells with tumor cells, it is concluded that the most effective treatment was PTX at 60 mg/kg + NCTD at 0.75 mg/kg.

Modeling of the human interleukin 12:receptor complex allows to engineer attenuated cytokine variants

Interleukin 12 (IL-12) plays major roles in immune defense against intracellular pathogens. By activating T cells and increasing antigen presentation, it is also a very potent anti-tumor molecule. Strong immune activation and systemic toxicity, however, so far limit its potential therapeutic use. Building on recent experimental structures of IL-12 related cytokine:receptor complexes, we here provide a high-resolution computational model of the human IL-12:receptor complex. We design attenuated IL-12 variants with lower receptor binding affinities based on molecular dynamics simulations, and subsequently validate them experimentally. These variants show reduced activation of natural killer cells while maintaining T cell activation. This immunological signature is important to develop IL-12 for cancer treatment, where natural killer cells contribute to severe side-effects. Taken together, our study provides detailed insights into structure and dynamics of the human IL-12:receptor complex and leverages them for engineering attenuated variants to elicit fewer side-effects while maintaining relevant biological activity.

Ambivalent role of FasL in murine acute graft-versus-host-disease

Fas ligand is increased in several immune-mediated diseases, including acute graft-versus-host disease, a donor cell-mediated disorder post-hematopoietic stem cell transplantation. In this disease, Fas ligand is involved in T-cell-mediated damage to host tissues. However, the role of its expression on donor non-T cells has, so far, never been addressed. Using a well-established CD4- and CD8-mediated graft-versus-host disease murine model, we found that precocious gut damage and mice mortality are increased with a graft of donor T- and B-depleted bone marrow cells devoid of Fas ligand as compared with their wild-type counterparts. Interestingly, serum levels of both soluble Fas ligand and IL-18 are drastically reduced in the recipients of Fas ligand-deficient grafts, indicating that soluble Fas ligand stems from donor bone marrow-derived cells. In addition, the correlation between the concentrations of these 2 cytokines suggests that IL-18 production arises through a soluble Fas ligand-driven mechanism. These data highlight the importance of Fas ligand-dependent production in IL-18 production and in mitigating acute graft-versus-host disease. Overall, our data reveal the functional duality of Fas ligand according to its source.

Inhibition of MC38 colon cancer growth by multicomponent chemoimmunotherapy with anti-IL-10R antibodies, HES-MTX nanoconjugate, depends on application of IL-12, IL-15 or IL-18 secreting dendritic cell vaccines

Background

The tumor microenvironment (TME) provides a conducive environment for the growth and survival of tumors. Negative factors present in TME, such as IL-10, may limit the effectiveness of cellular vaccines based on dendritic cells, therefore, it is important to control its effect. The influence of IL-10 on immune cells can be abolished e.g., by using antibodies against the receptor for this cytokine - anti-IL-10R. Furthermore, the anticancer activity of cellular vaccines can be enhanced by modifying them to produce proinflammatory cytokines, such as IL-12, IL-15 or IL-18. Additionally, an immunomodulatory dose of methotrexate and hydroxyethyl starch (HES-MTX) nanoconjugate may stimulate effector immune cells and eliminate regulatory T cells, which should enhance the antitumor action of immunotherapy based on DC vaccines. The main aim of our study was to determine whether the HES-MTX administered before immunotherapy with anti-IL-10R antibodies would change the effect of vaccines based on dendritic cells overproducing IL-12, IL-15, or IL-18.

Methods

The activity of modified DCs was checked in two therapeutic protocols - immunotherapy with the addition of anti-IL10R antibodies and chemoimmunotherapy with HES-MTX and anti-IL10R antibodies. The inhibition of tumor growth and the effectiveness of the therapy in inducing a specific antitumor response were determined by analyzing lymphoid and myeloid cell populations in tumor nodules, and the activity of restimulated splenocytes.

Results and conclusions

Using the HES-MTX nanoconjugate before immunotherapy based on multiple administrations of anti-IL-10R antibodies and cellular vaccines capable of overproducing proinflammatory cytokines IL-12, IL-15 or IL-18 created optimal conditions for the effective action of these vaccines in murine colon carcinoma MC38 model. The applied chemoimmunotherapy caused the highest inhibition of tumor growth in the group receiving DC/IL-15/IL-15Rα/TAg + DC/IL-18/TAg at the level of 72.4%. The use of cellular vaccines resulted in cytotoxic activity increase in both immuno- or chemoimmunotherapy. However, the greatest potential was observed both in tumor tissue and splenocytes obtained from mice receiving two- or three-component vaccines in the course of combined application. Thus, the designed treatment schedule may be promising in anticancer therapy.

Cytokine sustained delivery for cancer therapy; special focus on stem cell- and biomaterial- based delivery methods

As immune regulators, cytokines serve critical role as signaling molecules in response to danger, tissue damage, or injury. Importantly, due to their vital role in immunological surveillance, cytokine therapy has become a promising therapeutics for cancer therapy. Cytokines have, however, been used only in certain clinical settings. Two key characteristics of cytokines contribute to this clinical translational challenge: first, they are highly pleiotropic, and second, in healthy physiology, they are typically secreted and act very locally in tissues. Systemic administration of the cytokines can consequently result in serious side effects. Thus, scientists have sought various strategies to circumvent theses hurdles. Recent in vivo reports signify that cytokine delivery platforms can increase their safety and therapeutic efficacy in tumor xenografts. Meanwhile, cytokine delivery using multipotent stem cells, in particular mesenchymal stem/stromal cells (MSCs), and also a diversity of particles and biomaterials has demonstrated greater capability in this regards. Herein, we take a glimpse into the recent advances in cytokine sustained delivery using stem cells and also biomaterials to ease safe and effective treatments of a myriad of human tumors.

Role of NK Cells in Skin Wound Healing of Mice

NK cells are best known for their killing of virus-infected cells and tumor cells via release of cytotoxic factors. However, NK cells can also produce growth factors and cytokines, and thus have the potential to influence physiological processes such as wound healing. In this study, we test the hypothesis that NK cells play a physiological role in skin wound healing of C57BL/6J mice. Immunohistochemical and flow cytometry assays showed that NK cells accumulate in excisional skin wounds, peaking on day 5 postinjury. We also found that NK cells proliferate locally in wounds, and blocking IL-15 activity locally reduces NK cell proliferation and accumulation in wounds. Wound NK cells exhibit primarily a mature CD11b+CD27- and NKG2A+NKG2D- phenotype and express LY49I and proinflammatory cytokines such as IFN-γ, Tnf-a, and Il-1β. Systemic depletion of NK cells resulted in enhanced re-epithelization and collagen deposition, suggesting a negative role for these cells in skin wound healing. Depletion of NK cells did not influence accumulation of neutrophils or monocytes/macrophages in wounds but did reduce expression of IFN-γ, Tnf-a, and Il-1β, indicating that NK cells contribute to proinflammatory cytokine expression in wounds. In short, NK cells may impede physiological wound healing via production of proinflammatory cytokines.

Crosstalk of Inflammatory Cytokines within the Breast Tumor Microenvironment

Several immune and immunocompetent cells, including dendritic cells, macrophages, adipocytes, natural killer cells, T cells, and B cells, are significantly correlated with the complex discipline of oncology. Cytotoxic innate and adaptive immune cells can block tumor proliferation, and others can prevent the immune system from rejecting malignant cells and provide a favorable environment for tumor progression. These cells communicate with the microenvironment through cytokines, a chemical messenger, in an endocrine, paracrine, or autocrine manner. These cytokines play an important role in health and disease, particularly in host immune responses to infection and inflammation. They include chemokines, interleukins (ILs), adipokines, interferons, colony-stimulating factors (CSFs), and tumor necrosis factor (TNF), which are produced by a wide range of cells, including immune cells, such as macrophages, B-cells, T-cells, and mast cells, as well as endothelial cells, fibroblasts, a variety of stromal cells, and some cancer cells. Cytokines play a crucial role in cancer and cancer-related inflammation, with direct and indirect effects on tumor antagonistic or tumor promoting functions. They have been extensively researched as immunostimulatory mediators to promote the generation, migration and recruitment of immune cells that contribute to an effective antitumor immune response or pro-tumor microenvironment. Thus, in many cancers such as breast cancer, cytokines including leptin, IL-1B, IL-6, IL-8, IL-23, IL-17, and IL-10 stimulate while others including IL-2, IL-12, and IFN-γ, inhibit cancer proliferation and/or invasion and enhance the body's anti-tumor defense. Indeed, the multifactorial functions of cytokines in tumorigenesis will advance our understanding of cytokine crosstalk pathways in the tumor microenvironment, such as JAK/STAT, PI3K, AKT, Rac, MAPK, NF-κB, JunB, cFos, and mTOR, which are involved in angiogenesis, cancer proliferation and metastasis. Accordingly, targeting and blocking tumor-promoting cytokines or activating and amplifying tumor-inhibiting cytokines are considered cancer-directed therapies. Here, we focus on the role of the inflammatory cytokine system in pro- and anti-tumor immune responses, discuss cytokine pathways involved in immune responses to cancer and some anti-cancer therapeutic applications.

Targeting immune checkpoints: how to use natural killer cells for fighting against solid tumors

Natural killer (NK) cells are unique innate immune cells that mediate anti-viral and anti-tumor responses. Thus, they might hold great potential for cancer immunotherapy. NK cell adoptive immunotherapy in humans has shown modest efficacy. In particular, it has failed to demonstrate therapeutic efficiency in the treatment of solid tumors, possibly due in part to the immunosuppressive tumor microenvironment (TME), which reduces NK cell immunotherapy's efficiencies. It is known that immune checkpoints play a prominent role in creating an immunosuppressive TME, leading to NK cell exhaustion and tumor immune escape. Therefore, NK cells must be reversed from their dysfunctional status and increased in their effector roles in order to improve the efficiency of cancer immunotherapy. Blockade of immune checkpoints can not only rescue NK cells from exhaustion but also augment their robust anti-tumor activity. In this review, we discussed immune checkpoint blockade strategies with a focus on chimeric antigen receptor (CAR)-NK cells to redirect NK cells to cancer cells in the treatment of solid tumors.

Reviving human γδT cells from apoptosis induced by IL-12/18 via p-JNK inhibition

γδT cells recognize and exert cytotoxicity against tumor cells independently of MHC restriction and have antigen presentation and regulatory functions to promote adaptive immune responses. They are considered as potential immune cells for cellular immunotherapy in cancer patients. However, it is challenging to ex vivo expand human γδT cells that have superb effector functions and long-term survival for adoptive cancer therapy. We found that IL-12/18 combination could drastically promote IFN-γ secretion and cytotoxicity in human γδT cells. However, the enhanced activation of human γδT cells is accompanied by increased apoptosis and elevated expressions of co-inhibitory receptors under the stimulation of IL-12/18. We further demonstrated that IL-12/18 induced apoptosis of human γδT cells was in a phosphoantigen or IFN-γ-independent manner. Transcriptomic analysis suggested that IL-12/18-induced apoptosis of human γδT cells was mediated by the activation of JNK pathway. p-JNK inhibitor (SP-600125) treatment effectively revived human γδT cells from the apoptosis induced by IL-12/18 and maintained their enhanced IFN-γ production and cytotoxicity against tumor cells. Our results provide a novel and feasible strategy for ex vivo expansion of cytokine-activated human γδT cells, which could promote the efficacy of γδT cell adoptive immunotherapy in cancer patients.

Cell membrane-coated human hair nanoparticles for precise disease therapies

Precision medicine is the ultimate goal for current disease therapies, including tumor and infection. The lack of specific targeted drugs for liver cancer and the lack of specific anti-infective drugs in the treatment of diabetic foot ulcer with infection (DFI) are the representative obstacles in those 2 major diseases currently plaguing human beings. Inventing natural biocompatible polymers derived from natural materials is one of the main development directions of current bio-medical materials. Though previous studies have demonstrated the potential application values of human black hair-derived nanoparticles (HNP) in cancer, methicillin-resistant Staphylococcus aureus (MRSA) infection, and thrombosis scenarios treatments, it still has not solved the problem of low local therapeutic concentration and general targeting ability. Here, we firstly modified the HNP with membrane encapsulations, which endowed these dual-pure natural bio-fabricated materials with better targeting ability at the disease sites with no reduction in photothermal therapy (PTT) effect. HNP coated by red blood cell membrane loaded with DSPE-PEG-cRGD peptide for the therapeutic application of liver cancer greatly prolonged in vivo circulation time and enhanced local targeting efficacy as well as low toxicity; HNP coated by the murine macrophage cell membrane (RAWM) for the DFIs treatment greatly promoted the adhesive ability of HNP on the bacteria and thereby improved the killing effect. Briefly, the appropriate cell membranes camouflaged HNP nanomedicine has the characteristics of excellent photothermal effect, an all-natural source with excellent biocompatibility and easy access, which is expected to have huge potential in both benign and malignant diseases.

Production of Stem Cell Antigen 1 Sca-1/Ly-6A/E by Freshly Isolated NK Cells Cultured with Relevant Cytokines

Activated NK cells in appropriate conditions are known to express stem cell antigen 1 (Sca-1/Ly-6A/E). To investigate its production, NK cells isolated from mouse spleens were incubated ex vivo in the presence of different combinations of cytokines (IL-12, IL-15, IL-18, and IFNγ). Expression of Sca-1 was found to be considerably higher in NK cells incubated in the presence of IL-18, IL-15, and IL-12 than in those treated with IL-15 and IL-18 only. To test the hypothesis that the effect of IL-12 was due to stimulation of IFNγ production, we replaced IL-12 with IFNγ in some samples and added specific anti-IFNγ antibody to some samples cultured with IL-15/IL-18+IL-12. In the subpopulations incubated in the presence of IL-15/IL-18 with added IFNγ instead of IL-12, the expression of Sca-1 was not increased. By contrast, in samples treated with IL-15/IL-18+IL-12 and anti-IFNγ antibody, the expression of Sca-1 was activated to a similar extent as in those stimulated by IL-15/IL-18+IL-12 combination without the antibody. The obtained data suggest that IL-12 activates the production of Sca-1 by NK cells through an IFNγ-independent mechanism.

IL-1 Family Cytokines in Inflammatory Dermatoses: Pathogenetic Role and Potential Therapeutic Implications

The interleukin-1 (IL-1) family is involved in the correct functioning and regulation of the innate immune system, linking innate and adaptative immune responses. This complex family is composed by several cytokines, receptors, and co-receptors, all working in a balanced way to maintain homeostasis. Dysregulation of these processes results in tissue inflammation and is involved in the pathogenesis of common inflammatory dermatoses such as psoriasis, hidradenitis suppurativa, and atopic dermatitis. Therefore, therapeutic targeting of IL-1 pathways has been studied, and several monoclonal antibodies are currently being assessed in clinical trials. So far, promising results have been obtained with anti-IL-36R spesolimab and imsidolimab in pustular psoriasis, and their efficacy is being tested in other conditions.

Differential IL-12 signaling induces human natural killer cell activating receptor-mediated ligand-specific expansion

IL-12 is an essential cytokine involved in the generation of memory or memory-like NK cells. Mouse cytomegalovirus infection triggers NK receptor-induced, ligand-specific IL-12-dependent NK cell expansion, yet specific IL-12 stimulation ex vivo leading to NK cell proliferation and expansion is not established. Here, we show that IL-12 alone can sustain human primary NK cell survival without providing IL-2 or IL-15 but was insufficient to promote human NK cell proliferation. IL-12 signaling analysis revealed STAT5 phosphorylation and weak mTOR activation, which was enhanced by activating NK receptor upregulation and crosslinking leading to STAT5-dependent, rapamycin-sensitive, or TGFβ-sensitive NK cell IL-12-dependent expansion, independently of IL-12 receptor upregulation. Prolonged IL-2 culture did not impair IL-12-dependent ligand-specific NK cell expansion. These findings demonstrate that activating NK receptor stimulation promotes differential IL-12 signaling, leading to human NK cell expansion, and suggest adopting strategies to provide IL-12 signaling in vivo for ligand-specific IL-2-primed NK cell-based therapies.

The role of IL-1 family of cytokines and receptors in pathogenesis of COVID-19

A global pandemic has erupted as a result of the new brand coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This pandemic has been consociated with widespread mortality worldwide. The antiviral immune response is an imperative factor in confronting the recent coronavirus disease 2019 (COVID-19) infections. Meantime, cytokines recognize as crucial components in guiding the appropriate immune pathways in the restraining and eradication of the virus. Moreover, SARS-CoV-2 can induce uncontrolled inflammatory responses characterized by hyper-inflammatory cytokine production, which causes cytokine storm and acute respiratory distress syndrome (ARDS). As excessive inflammatory responses are contributed to the severe stage of the COVID-19 disease, therefore, the pro-inflammatory cytokines are regarded as the Achilles heel during COVID-19 infection. Among these cytokines, interleukin (IL-) 1 family cytokines (IL-1, IL-18, IL-33, IL-36, IL-37, and IL-38) appear to have a strong inflammatory role in severe COVID-19. Hence, understanding the underlying inflammatory mechanism of these cytokines during infection is critical for reducing the symptoms and severity of the disease. Here, the possible mechanisms and pathways involved in inflammatory immune responses are discussed.

Natural killer cells: a promising immunotherapy for cancer

As a promising alternative platform for cellular immunotherapy, natural killer cells (NK) have recently gained attention as an important type of innate immune regulatory cell. NK cells can rapidly kill multiple adjacent cancer cells through non-MHC-restrictive effects. Although tumors may develop multiple resistance mechanisms to endogenous NK cell attack, in vitro activation, expansion, and genetic modification of NK cells can greatly enhance their anti-tumor activity and give them the ability to overcome drug resistance. Some of these approaches have been translated into clinical applications, and clinical trials of NK cell infusion in patients with hematological malignancies and solid tumors have thus far yielded many encouraging clinical results. CAR-T cells have exhibited great success in treating hematological malignancies, but their drawbacks include high manufacturing costs and potentially fatal toxicity, such as cytokine release syndrome. To overcome these issues, CAR-NK cells were generated through genetic engineering and demonstrated significant clinical responses and lower adverse effects compared with CAR-T cell therapy. In this review, we summarize recent advances in NK cell immunotherapy, focusing on NK cell biology and function, the types of NK cell therapy, and clinical trials and future perspectives on NK cell therapy.

Crosstalk between macrophages and natural killer cells in the tumor microenvironment

The tumor microenvironment (TME) is jointly constructed by a variety of cell types, including tumor cells, immune cells, fibroblasts, and epithelial cells, among others. The cells within the TME interact with each other and with tumor cells to influence tumor development and progression. As the most abundant immune cells in the TME, macrophages regulate the immune network by not only secreting a large amount of versatile cytokines but also expressing a series of ligands or receptors on the surface to interact with other cells directly. Due to their strong plasticity, they exert both immunostimulatory and immunosuppressive effects in the complex TME. The major effector cells of the immune system that directly target cancer cells include but are not limited to natural killer cells (NKs), dendritic cells (DCs), macrophages, polymorphonuclear leukocytes, mast cells, and cytotoxic T lymphocytes (CTLs). Among them, NK cells are the predominant innate lymphocyte subsets that mediate antitumor and antiviral responses. The activation and inhibition of NK cells are regulated by cytokines and the balance between activating and inhibitory receptors. There is an inextricable regulatory relationship between macrophages and NK cells. Herein, we systematically elaborate on the regulatory network between macrophages and NK cells through soluble mediator crosstalk and cell-to-cell interactions. We believe that a better understanding of the crosstalk between macrophages and NKs in the TME will benefit the development of novel macrophage- or NK cell-focused therapeutic strategies with superior efficacies in cancer therapy.

IL-12 regulates type 3 immunity through interfollicular keratinocytes in psoriasiform inflammation

[Figure: see text].

Searching for the Elusive Regulatory Innate Lymphoid Cell

The complex nature of the innate lymphoid cell (ILC) family and wide range of ILC effector functions has been the focus of intense research. In addition to important roles in host defense, ILCs have central roles in maintaining tissue homeostasis and can promote immune tolerance. Alterations within the microenvironment can impart new functions on ILCs, and can even induce conversion to a distinct ILC family member. Complicating current definitions of ILCs are recent findings of distinct regulatory ILC populations that limit inflammatory responses or recruit other immunosuppressive cells such as regulatory T cells. Whether these populations are distinct ILC family members or rather canonical ILCs that exhibit immunoregulatory functions due to microenvironment signals has been the subject of much debate. In this review, we highlight studies identifying regulatory populations of ILCs that span regulatory NK-like cells, regulatory ILCs, and IL-10-producing ILC2s.

Astragalus membranaceus polysaccharides potentiate the growth-inhibitory activity of immune checkpoint inhibitors against pulmonary metastatic melanoma in mice

Astragalus membranaceus (A. membranaceus) is commonly used in various herbal formulations to treat several human and animal diseases. Polysaccharides, which are the major bioactive components in the A. membranaceus, exhibit various bioactive properties. However, the ability of A. membranaceus polysaccharides (APS) to activate the mucosal immune response has not been examined. We examined the effect of intranasal administration of APS on mucosal immune cell activation and the growth-inhibitory activity against pulmonary metastatic melanoma in mice by combination treatment with immune checkpoint blockade. The intranasal treatment of APS increased the number of lineage-CD11c+ dendritic cell (DCs) in the mesenteric lymph nodes (mLN) through the upregulation of CC-chemokine receptor 7 expression. Moreover, intranasal treatment of APS activated DCs, which further stimulated natural killer (NK) and T cells in the mLN. The APS/anti-PD-L1 antibody combination inhibited the pulmonary infiltration of B16 melanoma cells. The depletion of NK cells and CD8 T cells in mice mitigated the anti-cancer effect of this combination, thereby highlighting the critical role of NK cells and CD8 T cells in mediating anti-cancer immunity. These findings demonstrated that APS could be used as a topical mucosal adjuvant to enhance the immune check point inhibitor anti-cancer effect.

The Interplay between Oxidative Stress, Inflammation and Angiogenesis in Bladder Cancer Development

In 2018, 550,000 people were diagnosed with bladder cancer (BC), of which nearly 200,000 people died. Moreover, men are 4 times more likely than women to be diagnosed with BC. The risk factors include exposure to environmental and occupational chemicals, especially tobacco smoke, benzidine and genetic factors. Despite numerous studies, the molecular basis of BC development remains unclear. A growing body of evidence suggests that inflammation, oxidant-antioxidant imbalance and angiogenesis disorders may play a significant role in the development and progression of bladder cancer. The patients with bladder cancer were characterised by an increased level of reactive oxygen species (ROS), the products of lipid peroxidation, proinflammatory cytokines and proangiogenic factors as compared to controls. Furthermore, it was shown that polymorphisms localised in genes associated with these pathways may modulate the risk of BC. Interestingly, ROS overproduction may induce the production of proinflammatory cytokines, which finally activated angiogenesis. Moreover, the available literature shows that both inflammation and oxidative stress may lead to activation of angiogenesis and tumour progression in BC patients.

IL-10-Producing ILCs: Molecular Mechanisms and Disease Relevance

Innate lymphoid cells (ILCs) are mainly composed of natural killer (NK) cells and helper-like lymphoid cells, which play a vital role in maintaining tissue homeostasis, enhancing adaptive immunity and regulating tissue inflammation. Alteration of the distribution and function of ILCs subgroups are closely related to the pathogenesis of inflammatory diseases and cancers. Interleukin-10 (IL-10) is a highly pleiotropic cytokine, and can be secreted by several cell types, among of which ILCs are recently verified to be a key source of IL-10. So far, the stable production of IL-10 can only be observed in certain NK subsets and ILC2s. Though the regulatory mechanisms for ILCs to produce IL-10 are pivotal for understanding ILCs and potential intervenes of diseases, which however is largely unknown yet. The published studies show that ILCs do not share exactly the same mechanisms for IL-10 production with helper T cells. In this review, the molecular mechanisms regulating IL-10 production in NK cells and ILC2s are discussed in details for the first time, and the role of IL-10-producing ILCs in diseases such as infections, allergies, and cancers are summarized.

Structural basis for IL-12 and IL-23 receptor sharing reveals a gateway for shaping actions on T versus NK cells

Interleukin-12 (IL-12) and IL-23 are heterodimeric cytokines that are produced by antigen-presenting cells to regulate the activation and differentiation of lymphocytes, and they share IL-12Rβ1 as a receptor signaling subunit. We present a crystal structure of the quaternary IL-23 (IL-23p19/p40)/IL-23R/IL-12Rβ1 complex, together with cryoelectron microscopy (cryo-EM) maps of the complete IL-12 (IL-12p35/p40)/IL-12Rβ2/IL-12Rβ1 and IL-23 receptor (IL-23R) complexes, which reveal "non-canonical" topologies where IL-12Rβ1 directly engages the common p40 subunit. We targeted the shared IL-12Rβ1/p40 interface to design a panel of IL-12 partial agonists that preserved interferon gamma (IFNγ) induction by CD8+ T cells but impaired cytokine production from natural killer (NK) cells in vitro. These cell-biased properties were recapitulated in vivo, where IL-12 partial agonists elicited anti-tumor immunity to MC-38 murine adenocarcinoma absent the NK-cell-mediated toxicity seen with wild-type IL-12. Thus, the structural mechanism of receptor sharing used by IL-12 family cytokines provides a protein interface blueprint for tuning this cytokine axis for therapeutics.

Ovarian hormones-autophagy-immunity axis in menstruation and endometriosis

Menstruation occurs in few species and involves a cyclic process of proliferation, breakdown and regeneration under the control of ovarian hormones. Knowledge of normal endometrial physiology, as it pertains to the regulation of menstruation, is essential to understand disorders of menstruation. Accumulating evidence indicates that autophagy in the endometrium, under the regulation of ovarian hormones, can result in the infiltration of immune cells, which plays an indispensable role in the endometrium shedding, tissue repair and prevention of infections during menstruation. In addition, abnormal autophagy levels, together with resulting dysregulated immune system function, are associated with the pathogenesis and progression of endometriosis. Considering its potential value of autophagy as a target for the treatment of menstrual-related and endometrium-related disorders, we review the activity and function of autophagy during menstrual cycles. The role of the estrogen/progesterone-autophagy-immunity axis in endometriosis are also discussed.

IL-12 Family Cytokines in Cancer and Immunotherapy

The IL-12 family cytokines are a group of unique heterodimeric cytokines that include IL-12, IL-23, IL-27, IL-35 and, most recently, IL-39. Recent studies have solidified the importance of IL-12 cytokines in shaping innate and adaptive immune responses in cancer and identified multipronged roles for distinct IL-12 family members, ranging from effector to regulatory immune functions. These cytokines could serve as promising candidates for the development of immunomodulatory therapeutic approaches. Overall, IL-12 can be considered an effector cytokine and has been found to engage anti-tumor immunity by activating the effector Th1 response, which is required for the activation of cytotoxic T and NK cells and tumor clearance. IL-23 and IL-27 play dual roles in tumor immunity, as they can both activate effector immune responses and promote tumor growth by favoring immune suppression. IL-35 is a potent regulatory cytokine and plays a largely pro-tumorigenic role by inhibiting effector T cells. In this review, we summarize the recent findings on IL-12 family cytokines in the control of tumor growth with an emphasis primarily on immune regulation. We underscore the clinical implications for the use of these cytokines either in the setting of monotherapy or in combination with other conventional therapies for the more effective treatment of malignancies.

Cancer immunotherapy harnessing γδ T cells and programmed death-1

Cancer immunotherapy has received increasing attention since the success of CTLA-4 and programmed death-1 (PD-1) immune checkpoint inhibitors and CAR-T cells. One of the most promising next-generation cancer treatments is adoptive transfer of immune effector cells. Developing an efficacious adoptive transfer therapy requires growing large numbers of highly purified immune effector cells in a short period of time. γδ T cells can be effectively expanded using synthetic antigens such as pyrophosphomonoesters and nitrogen-containing bisphosphonates (N-BPs). Pyrophosphomonoester antigens, initially identified in mycobacterial extracts, were used for this purpose in the early years of the development of γδ T cell-based therapy. GMP-grade N-BPs, which are now commercially available, are used in many clinical trials worldwide. In order to develop N-BPs for cancer immunotherapy, N-BP prodrugs have been synthesized; among these, tetrakis-pivaloyloxymethyl 2-(thiazole-2-ylamino)ethylidene-1,1-bisphosphonate (PTA) is the most potent compound for stimulating γδ T cells. The activated γδ T cells express high levels of PD-1, suggesting the potential for a combination therapy harnessing γδ T cells and PD-1 immune checkpoint inhibitors. In addition, the functions of γδ T cells can be modified by IL-18. Collectively, the recent findings show that γδ T cells are one of the most promising immune effector subsets for the development of novel cancer immunotherapy.

Comparison of a Novel Bisphosphonate Prodrug and Zoledronic Acid in the Induction of Cytotoxicity in Human Vγ2Vδ2 T Cells

Increasing attention has been paid to human γδ T cells expressing Vγ2Vδ2 T cell receptor (also termed Vγ9Vδ2) in the field of cancer immunotherapy. We have previously demonstrated that a novel bisphosphonate prodrug, tetrakis-pivaloyloxymethyl 2-(thiazole-2-ylamino)ethylidene-1,1-bisphosphonate (PTA), efficiently expands peripheral blood Vγ2Vδ2 T cells to purities up to 95–99% in 10–11 days. In the present study, we first examined the effect of PTA on farnesyl diphosphate synthase (FDPS) using liquid chromatography mass spectrometry (LC-MS) to analyze the mechanism underlying the PTA-mediated expansion of Vγ2Vδ2 T cells. We find that the prodrug induced the accumulation of both isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP), direct upstream metabolites of FDPS. This indicates that not only IPP but also DMAPP plays an important role in PTA-mediated stimulation of Vγ2Vδ2 T cells. We next analyzed TCR-independent cytotoxicity of Vγ2Vδ2 T cells. When human lung cancer cell lines were challenged by Vγ2Vδ2 T cells, no detectable cytotoxicity was observed in 40 min. The lung cancer cell lines were, however, significantly killed by Vγ2Vδ2 T cells after 4–16 h in an effector-to-target ratio-dependent manner, demonstrating that Vγ2Vδ2 T cell-based cell therapy required a large number of cells and longer time when tumor cells were not sensitized. By contrast, pulsing tumor cell lines with 10–30 nM of PTA induced significant lysis of tumor cells by Vγ2Vδ2 T cells even in 40 min. Similar levels of cytotoxicity were elicited by ZOL at concentrations of 100–300 μM, which were much higher than blood levels of ZOL after infusion (1–2 μM), suggesting that standard 4 mg infusion of ZOL was not enough to sensitize lung cancer cells in clinical settings. In addition, Vγ2Vδ2 T cells secreted interferon-γ (IFN-γ) when challenged by lung cancer cell lines pulsed with PTA in a dose-dependent manner. Taken together, PTA could be utilized for both expansion of Vγ2Vδ2 T cells ex vivo and sensitization of tumor cells in vivo in Vγ2Vδ2 T cell-based cancer immunotherapy. For use in patients, further studies on drug delivery are essential because of the hydrophobic nature of the prodrug.