Natural killer cells and other innate lymphoid cells in cancer. Nat Rev Immunol. 2018;18:671-688. [PMID: 30209347 DOI: 10.1038/s41577-018-0061-z]

Dynamics of liver cancer cellular taxa revealed through single-cell RNA sequencing: Advances and challenges

Liver cancer is a leading cause of death worldwide, representing a substantial public health challenge. The advent of single-cell RNA sequencing has significantly advanced our understanding of cellular dynamics from the onset of liver cancer to therapeutic intervention. This technology has unveiled profound insights into cancer heterogeneity and the tumor microenvironment (TME), enabling the identification of key molecular drivers and phenotypic landscapes of liver cancer at a single-cell resolution. This review highlights recent advancements in mapping functional cell subsets, phenotypic alterations, and the diversity of the TME. These insights are pivotal for advancing targeted therapies and developing prognostic tools. Moreover, this review covers the ongoing challenges and advances from tumor initiation to progression, offering a detailed perspective on advancing personalized treatment.

Targeting metabolic dysfunction of CD8 T cells and natural killer cells in cancer

The importance of metabolic pathways in regulating immune responses is now well established, and a mapping of the bioenergetic metabolism of different immune cell types is under way. CD8 T cells and natural killer (NK) cells contribute to cancer immunosurveillance through their cytotoxic functions and secretion of cytokines and chemokines, complementing each other in target recognition mechanisms. Several immunotherapies leverage these cell types by either stimulating their activity or redirecting their specificity against tumour cells. However, the anticancer activity of CD8 T cells and NK cells is rapidly diminished in the tumour microenvironment, closely linked to a decline in their metabolic capacities. Various strategies have been developed to restore cancer immunosurveillance, including targeting bioenergetic metabolism or genetic engineering. This Review provides an overview of metabolic dysfunction in CD8 T cells and NK cells within the tumour microenvironment, highlighting current therapies aiming to overcome these issues.

Mesenchymal Stem/Stromal cells in solid tumor Microenvironment: Orchestrating NK cell remodeling and therapeutic insights

Mesenchymal stem/stromal cells (MSCs), originating from normal tissues, possess the capacity to home to tumor sites and differentiate into tumor-associated MSCs (TA-MSCs), which are instrumental in shaping an immunosuppressive milieu within tumors. Natural killer (NK) cells, integral to the innate immune system, are endowed with the ability to eradicate target cells autonomously, serving as an immediate defense against neoplastic growths. Nonetheless, within the tumor microenvironment (TME), NK cells often exhibit a decline in both their numerical presence and functionality. TA-MSCs have been shown to exert profound inhibitory effects on the functions of tumor-infiltrating immune cells, notably NK cells. Understanding the mechanisms by which TA-MSCs contribute to NK cell dysfunction is critical for the advancement of immune surveillance and the enhancement of tumoricidal responses. This review summarizes existing literature on NK cell modulation by TA-MSCs within the TME and proposes innovative strategies to augment antitumor immunity.

NK cell-based immunotherapy in hepatocellular carcinoma: An attractive therapeutic option for the next decade

Hepatocellular carcinoma (HCC), a major subtype of liver cancer, poses significant therapeutic challenges due to its late diagnosis and rapid progression. The evolving landscape of immunotherapy offers a beacon of hope, with natural killer (NK) cells emerging as pivotal players in combating HCC. NK cells are unique cytotoxic lymphocytes that are essential in the fight against infections and malignancies. Phenotypic and functional NK cell abnormalities have been shown in HCC patients, indicating their significance as a component of the innate immune system against cancer. This review elucidates the critical role of NK cells in combating HCC, focusing on their interaction with the tumor microenvironment, the development of NK cell-based therapies, and the innovative strategies to enhance their efficacy in the immunosuppressive milieu of HCC. The review delves into the various therapeutic strategies, including autologous and allogeneic NK cell therapies, genetic engineering to improve NK cell resilience and targeting, and the integration of NK cells with other immunotherapeutic approaches like checkpoint inhibitors and oncolytic virotherapy. By highlighting recent advancements and the ongoing challenges in the field, this review sets the stage for future research directions that could unlock the full potential of NK cell-based immunotherapy for HCC, offering a beacon of hope for patients battling this formidable cancer.

Natural killer cells in neuroblastoma: immunological insights and therapeutic perspectives

Natural killer (NK) cells have multifaceted roles within the complex tumor milieu. They are pivotal components of innate immunity and shape the dynamic landscape of tumor-immune cell interactions, and thus can be leveraged for use in therapeutic interventions. NK-based immunotherapies have had remarkable success in hematological malignancies, but these therapies are met with many challenges in solid tumors, including neuroblastoma (NB), a childhood tumor arising from the sympathetic nervous system. With a focus on NB, this review outlines the mechanisms employed by NK cells to recognize and eliminate malignant cells, delving into the dynamic relationship between ligand-receptor interactions, cytokines, and other molecules that facilitate the cross talk between NK and NB cells. We discuss the immunomodulatory functions of NK cells and the mechanisms that contribute to loss of this immunosurveillance in NB, with a focus on how this dynamic has been utilized in recent immunotherapy advancements for NB.

Advancing cancer drug development with mechanistic mathematical modeling: bridging the gap between theory and practice

Quantitative predictive modeling of cancer growth, progression, and individual response to therapy is a rapidly growing field. Researchers from mathematical modeling, systems biology, pharmaceutical industry, and regulatory bodies, are collaboratively working on predictive models that could be applied for drug development and, ultimately, the clinical management of cancer patients. A plethora of modeling paradigms and approaches have emerged, making it challenging to compile a comprehensive review across all subdisciplines. It is therefore critical to gauge fundamental design aspects against requirements, and weigh opportunities and limitations of the different model types. In this review, we discuss three fundamental types of cancer models: space-structured models, ecological models, and immune system focused models. For each type, it is our goal to illustrate which mechanisms contribute to variability and heterogeneity in cancer growth and response, so that the appropriate architecture and complexity of a new model becomes clearer. We present the main features addressed by each of the three exemplary modeling types through a subjective collection of literature and illustrative exercises to facilitate inspiration and exchange, with a focus on providing a didactic rather than exhaustive overview. We close by imagining a future multi-scale model design to impact critical decisions in oncology drug development.

The theragnostic advances of exosomes in managing leukaemia

Leukaemia, a group of haematological malignancies, presents ongoing diagnosis, prognosis, and treatment challenges. A major obstacle in treating this disease is the development of drug resistance. Overcoming drug resistance poses a significant barrier to effective leukaemia treatment. The emergence of exosome research has unveiled new insights into the probable theragnostic implementations in leukaemia. Various research has exhibited the diagnostic possibilities of exosomes in identifying leukaemia-specific biomarkers, including genetic mutations and fusion transcripts. Additionally, exosomes have been implicated in disease progression and treatment response, rendering them appealing targets for therapeutics. Exosomes, originating from diverse cell types, are instrumental in intercellular communication as they participate in the functional transportation of molecules like proteins, nucleic acids and lipids across space. Exosomes have a dual role in immune regulation, mediating immune suppression and modulating anti-leukaemia immune responses. Interestingly, exosomes can even act as drug transport vehicles. This review delves into the intricate process of exosome biogenesis, shedding light on their formation and release from donor cells. The key mechanisms engaged in exosome biogenesis, for instance, the endosomal sorting complexes required for transport (ESCRT) machinery and ESCRT-independent pathways, are thoroughly discussed. Looking ahead, future approaches that leverage innovative technologies hold the promise of revolutionizing disease management and improving patient outcomes.

Novel immunotherapeutic approaches in gastric cancer

Gastric cancer is a malignant tumor that ranks third in cancer-related deaths worldwide. Early-stage gastric cancer can often be effectively managed through surgical resection. However, the majority of cases are diagnosed in advanced stages, where outcomes with conventional radiotherapy and chemotherapy remain unsatisfactory. Immunotherapy offers a novel approach to treating molecularly heterogeneous gastric cancer by modifying the immunosuppressive tumor microenvironment. Immune checkpoint inhibitors and adoptive cell therapy are regarded as promising modalities in cancer immunotherapy. Food and Drug Administration-approved programmed death-receptor inhibitors, such as pembrolizumab, in combination with chemotherapy, have significantly extended overall survival in gastric cancer patients and is recommended as a first-line treatment. Despite challenges in solid tumor applications, adoptive cell therapy has demonstrated efficacy against various targets in gastric cancer treatment. Among these approaches, chimeric antigen receptor-T cell therapy research is the most widely explored and chimeric antigen receptor-T cell therapy targeting claudin18.2 has shown acceptable safety and robust anti-tumor capabilities. However, these advancements primarily remain in preclinical stages and further investigation should be made to promote their clinical application. This review summarizes the latest research on immune checkpoint inhibitors and adoptive cell therapy and their limitations, as well as the role of nanoparticles in enhancing immunotherapy.

A Comparison of Cellular Immune Response and Immunological Biomarkers in Laparoscopic Surgery for Colorectal Cancer and Benign Disorders

BACKGROUND

Surgical trauma causes immune impairment, but it is largely unknown whether surgery for cancer and benign diseases instigate comparable levels of immune inhibition. Here, we compared the impact of laparoscopic surgery on immunological biomarkers in patients with colorectal cancer (CRC) and ventral hernia (VH).

METHODS

Natural Killer cell activity (NKA), leukocyte subsets, and soluble programmed death ligand 1 (sPD-L1) were measured in blood samples collected from CRC (n = 29) and VH (n = 9) patients preoperatively (PREOP) and on postoperative day (POD) 1, 3-6, 2 weeks and 3 months. NKA was evaluated by the NK Vue assay that uses the level of IFNγ as a surrogate marker of NKA. Normal NKA was defined as IFNγ > 250 pg/mL and low NKA was defined as IFNγ < 250 pg/mL.

RESULTS

The CRC cohort was classified into either PREOPLOW having preoperative low NKA or PREOPHIGH having preoperative normal NKA. The median NKA of the PREOPLOW subset was only in the normal range in the POD3 months sample, whereas median NKA of the PREOPHIGH subset and the VH cohort were only low in the POD1 sample. While PREOPLOW differed from VH in the PREOP-, POD1-, and POD3-6 samples (P =.0006, P = .0181, and P = .0021), NKA in PREOPHIGH and VH differed in the POD1 samples (P = .0226). There were no apparent differences in the distribution of leukocyte subsets in the perioperative period between the cohorts.

CONCLUSION

CRC patients with preoperative normal NKA and VH patients showed the same pattern of recovery in NKA, while the CRC subset with preoperative low NKA seemed to experience prolonged NK cell impairment. As low NKA is associated with recurrence, preoperative level of NKA may identify patients who will benefit from immune-enhancing therapy in the perioperative period.

Ferroptosis to Pyroptosis Regulation by Iron-Based Nanocatalysts for Enhanced Tumor Immunotherapy

Immunogenic cell death serves as a pivotal mechanism in enhancing antitumor immunotherapy by engaging both innate and adaptive immune responses. However, a key unanswered question is which mode of cell death, particularly ferroptosis or pyroptosis, serves as the optimal pathway for activating the immune response. In this study, we introduce an innovative iron-based nanocatalytic medicine that strategically regulates ferroptosis to pyroptosis to augment antitumor immunotherapy. By harnessing the intricate interplay between iron and carbonyl cyanide m-chlorophenyl hydrazone (CP), we engineered the nanomedicine which is capable of regulating ferroptosis to the more immunogenic pyroptosis within tumor cells. In vitro analyses revealed that the treatment with CP-encapsulated iron-based nanomedicine (HFCP) can effectively induce pyroptosis of cancer cells, exhibiting greatly enhanced efficacy in eradicating tumor cells and stimulating immune responses compared to the ferroptosis-inducing counterpart without CP incorporation (iron alone). Resultantly, HFCP not only effectively inhibited primary tumor growth but also suppressed the growth of untreated distant tumors to a large extent, underscoring a notably induced immune memory. Taken together, these results indicate that HFCP-induced pyroptosis offers a significantly more powerful approach to tumor immunotherapy than ferroptosis, offering promising potentials for achieving long-term immunotherapeutic outcomes through the reversal of the immunosuppressive tumor microenvironment and the effective regulation of immunogenic cell death modes.

Tissue-colonizing disseminated tumor cells secrete prostaglandin E2 to promote NK cell dysfunction and evade anti-metastatic immunity

Natural killer (NK) cells are critical for anti-metastatic immunity and can eliminate metastasizing tumor cells within circulation and sites of metastatic seeding. Here, we show that disseminated tumor cells (DTCs) colonizing the mouse lung secrete prostaglandin E2 (PGE2) to locally induce NK cell dysfunction, allowing outgrowing metastases to escape immune control and establish metastatic disease. Mechanistically, PGE2 signaling through its receptors EP2 and EP4 mediates NK cell dysfunction, which leads to reprogramming of NK cell gene expression and results in impaired production of anti-metastatic cytokines. In human cancer patients, the PGE2-EP2/EP4 axis is associated with NK cell dysfunction within distant organ metastases. Disabling EP2/EP4 signaling in NK cells prevents their dysfunction in DTC-colonized lungs and achieves effective NK cell-mediated control of metastatic disease. Our findings reveal a suppressive signaling axis exploited by metastasizing tumor cells to escape immune control in distant organs that could be targeted for metastatic cancer therapy.

Metabolic reprogramming and therapeutic resistance in primary and metastatic breast cancer

Metabolic alterations, a hallmark of cancer, enable tumor cells to adapt to their environment by modulating glucose, lipid, and amino acid metabolism, which fuels rapid growth and contributes to treatment resistance. In primary breast cancer, metabolic shifts such as the Warburg effect and enhanced lipid synthesis are closely linked to chemotherapy failure. Similarly, metastatic lesions often display distinct metabolic profiles that not only sustain tumor growth but also confer resistance to targeted therapies and immunotherapies. The review emphasizes two major aspects: the mechanisms driving metabolic resistance in both primary and metastatic breast cancer, and how the unique metabolic environments in metastatic sites further complicate treatment. By targeting distinct metabolic vulnerabilities at both the primary and metastatic stages, new strategies could improve the efficacy of existing therapies and provide better outcomes for breast cancer patients.

Light-Controlled Bioorthogonal Chemistry Altered Natural Killer Cell Activity for Boosted Adoptive Immunotherapy

Natural killer (NK) cell-based immunotherapy has received much attention in recent years. However, its practical application is still suffering from the decreased function and inadequate infiltration of NK cells in the immunosuppressive microenvironment of solid tumors. Herein, we construct light-responsive porphyrin Fe array-armed NK cells (denoted as NK@p-Fe) for cell behavior modulation via bioorthogonal catalysis. By installing cholesterol-modified porphyrin Fe molecules on the NK cell surface, a catalytic array with light-harvesting capabilities is formed. This functionality transforms NK cells into cellular factories capable of catalyzing the production of active agents in a light-controlled manner. NK@p-Fe can generate the active antineoplastic drug doxorubicin through bioorthogonal reactions to enhance the cytotoxic function of NK cells. Beyond drug synthesis, NK@p-Fe can also bioorthogonally catalyze the production of the FDA-approved immune agonist imiquimod (IMQ). The activated immune agonist plays a dual role, inducing dendritic cell maturation for NK cell activation and reshaping the tumor immunosuppressive microenvironment for NK cell infiltration. This work represents a paradigm for the modulation of adoptive cell behaviors to boost cancer immunotherapy by bioorthogonal catalysis.

Biomaterials' enhancement of immunotherapy for breast cancer by targeting functional cells in the tumor micro-environment

Immunotherapy for breast cancer is now being considered clinically, and more recently, the number of investigations aimed specifically at nano-biomaterials-assisted immunotherapy for breast cancer treatment is growing. Alterations of the breast cancer micro-environment can play a critical role in anti-tumor immunity and cancer development, progression and metastasis. The improvement and rearrangement of tumor micro-environment (TME) may enhance the permeability of anti-tumor drugs. Therefore, targeting the TME is also an ideal and promising option during the selection of effective nano-biomaterial-based immuno-therapeutic strategies excepted for targeting intrinsic resistant mechanisms of the breast tumor. Although nano-biomaterials designed to specifically release loaded anti-tumor drugs in response to tumor hypoxia and low pH conditions have shown promises and the diversity of the TME components also supports a broad targeting potential for anti-tumor drug designs, yet the applications of nano-biomaterials for targeting immunosuppressive cells/immune cells in the TME for improving the breast cancer treating outcomes, have scarcely been addressed in a scientific review. This review provides a thorough discussion for the application of the different forms of nano-biomaterials, as carrier vehicles for breast cancer immunotherapy, targeting specific types of immune cells in the breast tumor microenvironment. In parallel, the paper provides a critical analysis of current advances/challenges with leading nano-biomaterial-mediated breast cancer immunotherapeutic strategies. The current review is timely and important to the cancer research field and will provide a critical tool for nano-biomaterial design and research groups pushing the clinical translation of new nano-biomaterial-based immuno-strategies targeting breast cancer TME, to further open new avenues for the understanding, prevention, diagnosis and treatment of breast cancer, as well as other cancer types.

The hallmarks of cancer immune evasion

According to the widely accepted "three Es" model, the host immune system eliminates malignant cell precursors and contains microscopic neoplasms in a dynamic equilibrium, preventing cancer outgrowth until neoplastic cells acquire genetic or epigenetic alterations that enable immune escape. This immunoevasive phenotype originates from various mechanisms that can be classified under a novel "three Cs" conceptual framework: (1) camouflage, which hides cancer cells from immune recognition, (2) coercion, which directly or indirectly interferes with immune effector cells, and (3) cytoprotection, which shields malignant cells from immune cytotoxicity. Blocking the ability of neoplastic cells to evade the host immune system is crucial for increasing the efficacy of modern immunotherapy and conventional therapeutic strategies that ultimately activate anticancer immunosurveillance. Here, we review key hallmarks of cancer immune evasion under the "three Cs" framework and discuss promising strategies targeting such immunoevasive mechanisms.

Nuclear EGFR in breast cancer suppresses NK cell recruitment and cytotoxicity

Natural Killer (NK) cells can target and destroy cancer cells, yet tumor microenvironments typically suppress NK cell recruitment and cytotoxicity. The epidermal growth factor receptor (EGFR) is a potent oncogene that can activate survival, migration, and proliferation pathways, and clinical data suggests it may also play an immunomodulating role in cancers. Recent work has demonstrated a novel role for nuclear EGFR (nEGFR) in regulating transcriptional events unique from the kinase domain. Using a novel peptide therapeutic (cSNX1.3) that inhibits retrograde trafficking of EGFR and an EGFR nuclear localization mutant, we discovered that nEGFR suppresses NK cell recruitment and cytotoxicity. RNA-Seq analysis of breast cancer cells treated with cSNX1.3 or modified to lack a nuclear localization sequence (EGFRΔNLS) revealed the EGF-dependent induction of NK activating receptor ligands, while kinase inhibition by erlotinib did not impact these genes. NanoString analysis of tumor-bearing WAP-TGFα transgenic mice treated with cSNX1.3 demonstrated an increase in immune cell populations and activating genes. Additionally, immunohistochemistry confirmed an increase in NK cells upon cSNX1.3 treatment. Finally, cSNX1.3 treatment was found to enhance NK cell recruitment and cytotoxicity in vitro. Together, the data demonstrate a unique immunomodulatory role for nEGFR.

GPR34 is a metabolic immune checkpoint for ILC1-mediated antitumor immunity

Type 1 innate lymphoid cells (ILC1s) are a class of tissue-resident cells with antitumor activity, suggesting its possible role in solid tumor immune surveillance, but it is not clear whether manipulating ILC1s can induce potent antitumor immune responses. Here, we found that G-protein-coupled receptor 34 (GPR34), a receptor for lysophosphatidylserine (LysoPS), was highly expressed on ILC1s but not on conventional natural killer cells in the tumor microenvironment. LysoPS was enriched in the tumor microenvironment and could inhibit ILC1 activation via GPR34. Genetic deletion of LysoPS synthase Abhd16a expression in tumors or Gpr34 expression in ILC1s or antagonizing GPR34 enhanced ILC1 antitumor activity. In individuals with cancer, ABHD16A expression in tumors or GPR34 expression in ILC1s was inversely correlated with the antitumor activity of ILC1s or ILC1-like cells. Thus, our results demonstrate that manipulating ILC1s can induce potent antitumor immunity, and GPR34 is a metabolic immune checkpoint that can be targeted to develop ILC1-based immunotherapy.

Biologically-informed killer cell immunoglobulin-like receptor gene annotation tool

SUMMARY

Natural killer (NK) cells are essential components of the innate immune system, with their activity significantly regulated by Killer cell Immunoglobulin-like Receptors (KIRs). The diversity and structural complexity of KIR genes present significant challenges for accurate genotyping, essential for understanding NK cell functions and their implications in health and disease. Traditional genotyping methods struggle with the variable nature of KIR genes, leading to inaccuracies that can impede immunogenetic research. These challenges extend to high-quality phased assemblies, which have been recently popularized by the Human Pangenome Consortium. This article introduces BAKIR (Biologically informed Annotator for KIR locus), a tailored computational tool designed to overcome the challenges of KIR genotyping and annotation on high-quality, phased genome assemblies. BAKIR aims to enhance the accuracy of KIR gene annotations by structuring its annotation pipeline around identifying key functional mutations, thereby improving the identification and subsequent relevance of gene and allele calls. It uses a multi-stage mapping, alignment, and variant calling process to ensure high-precision gene and allele identification, while also maintaining high recall for sequences that are significantly mutated or truncated relative to the known allele database. BAKIR has been evaluated on a subset of the HPRC assemblies, where BAKIR was able to improve many of the associated annotations and call novel variants. BAKIR is freely available on GitHub, offering ease of access and use through multiple installation methods, including pip, conda, and singularity container, and is equipped with a user-friendly command-line interface, thereby promoting its adoption in the scientific community.

AVAILABILITY AND IMPLEMENTATION

BAKIR is available at github.com/algo-cancer/bakir.

Expression, regulation, and function of PD-L1 on non-tumor cells in the tumor microenvironment

Antiprogrammed death ligand 1 (PD-L1) therapy is a leading immunotherapy, but only some patients with solid cancers benefit. Overwhelming evidence has revealed that PD-L1 is expressed on various immune cells in the tumor microenvironment (TME), including macrophages, dendritic cells, and regulatory T cells, modulating tumor immunity and influencing tumor progression. PD-L1 can also be located on tumor cell membranes as well as in exosomes and cytoplasm. Accordingly, the dynamic expression and various forms of PD-L1 might explain the therapy's limited efficacy and resistance. Herein a systematic summary of the expression of PD-L1 on different immune cells and their regulatory mechanisms is provided to offer a solid foundation for future studies.

Natural killer cell-based cancer immunotherapy: from basics to clinical trials

Cellular immunotherapy exploits the capacity of the human immune system in self-protection and surveillance to achieve the anti-tumor effects. Natural killer (NK) cells are lymphocytes of innate immune system and they display a unique inherent ability to identify and eliminate tumor cells. In this review, we first introduce the basic characteristics of NK cells in the physiological and pathological milieus, followed by a discussion of their effector function and immunosuppression in the tumor microenvironment. Clinical strategies and reports regarding NK cellular therapy are analyzed in the context of tumor treatment, especially against solid tumors. Given the widely studied T-cell therapy in the recent years, particularly the chimeric antigen receptor (CAR) T-cell therapy, we compare the technical features of NK- and T-cell based tumor therapies at the clinical front. Finally, the technical challenges and potential solutions for both T and NK cell-based immunotherapies in treating tumor malignancies are delineated. By overviewing its clinical applications, we envision the NK-cell based immunotherapy as an up-and-comer in cancer therapeutics.

Distorted frequency and functionality of natural killer cells in pemphigus vulgaris: A potential therapeutic target

Pemphigus vulgaris (PV) is a rare autoimmune disorder where autoantibodies target the desmosomal proteins resulting in blistering of oral mucosa and skin. While the pathogenesis of PV is mainly mediated by the adaptive immune system, key players of innate immunity are also emerging. This study outlines the phenotypic as well as functional attributes of NK cells in PV. Through in-depth analysis using flow cytometry we identified an increase in the frequency of CD56+ CD3- NK cells and their subtypes in periphery. Along with this there is an increased frequency of IFNγ+ CD56bright CD16dim NK cells. mRNA expression of sorted NK cells for differentially expressed genes, particularly key transcription factors such as T-bet and EOMES, as well as surface receptors like NKG2D and KIR2D, and the cytokine IFNγ, displayed significant upregulation. A significant activation of NK cells was seen in the disease state. The levels of perforin and IFNγ were significantly elevated in the culture supernatants of patients. Additionally, a significantly higher cytotoxicity of NK cells in PV was observed. In lesioned tissues of PV, NK related markers were significantly increased. Lastly, we observed NK cells using confocal microscopy in the tissue biopsies of patients which showed significant infiltration of CD56+ CD3- NK cells at the lesional sites. This study aimed to shed light on the pivotal role of NK cells in the immunopathology of PV, offering a thorough understanding of their behaviour and changes in expression which might help in contributing to the development of novel therapeutics.

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

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

Naive primary neutrophils play a dual role in the tumor microenvironment

The tumor microenvironment (TME) is characterized by a network of cancer cells, recruited immune cells, and extracellular matrix (ECM). However, the specific role of neutrophils during tumor development, and their interactions with other immune cells is still not well understood. Here, we use both standard well plate culture and an under oil microfluidic (UOM) assay with an integrated ECM bridge to elucidate how naive primary neutrophils respond to tumor cells. Our data demonstrated that tumor cells trigger cluster formation in neutrophils accompanied with the generation of reactive oxygen species (ROS) and neutrophil extracellular trap (NET) release. Using label-free optical metabolic imaging (OMI), we observed changes in the metabolic activities of primary neutrophils during the different clustering phases when challenged with tumor cells. Finally, our data demonstrates that neutrophils in direct contact, or in close proximity, with tumor cells exhibit greater metabolic activities compared to non-contact neutrophils.

Metabolic reprogramming and immune evasion: the interplay in the tumor microenvironment

Tumor cells possess complex immune evasion mechanisms to evade immune system attacks, primarily through metabolic reprogramming, which significantly alters the tumor microenvironment (TME) to modulate immune cell functions. When a tumor is sufficiently immunogenic, it can activate cytotoxic T-cells to target and destroy it. However, tumors adapt by manipulating their metabolic pathways, particularly glucose, amino acid, and lipid metabolism, to create an immunosuppressive TME that promotes immune escape. These metabolic alterations impact the function and differentiation of non-tumor cells within the TME, such as inhibiting effector T-cell activity while expanding regulatory T-cells and myeloid-derived suppressor cells. Additionally, these changes lead to an imbalance in cytokine and chemokine secretion, further enhancing the immunosuppressive landscape. Emerging research is increasingly focusing on the regulatory roles of non-tumor cells within the TME, evaluating how their reprogrammed glucose, amino acid, and lipid metabolism influence their functional changes and ultimately aid in tumor immune evasion. Despite our incomplete understanding of the intricate metabolic interactions between tumor and non-tumor cells, the connection between these elements presents significant challenges for cancer immunotherapy. This review highlights the impact of altered glucose, amino acid, and lipid metabolism in the TME on the metabolism and function of non-tumor cells, providing new insights that could facilitate the development of novel cancer immunotherapies.

The Role of Tumor Microenvironment in Pancreatic Cancer Immunotherapy: Current Status and Future Perspectives

Pancreatic cancer comprises different subtypes, where most cases include ductal adenocarcinoma (PDAC). It is one of the deadliest tumor types, with a poor prognosis. In the majority of patients, the disease has already spread by the time of diagnosis, making full recovery unlikely and increasing mortality risk. Despite developments in its detection and management, including chemotherapy, radiotherapy, and targeted therapies as well as advances in immunotherapy, only in about 13% of PDAC patients does the overall survival exceed 5 years. This may be attributed, at least in part, to the highly desmoplastic tumor microenvironment (TME) that acts as a barrier limiting perfusion, drug delivery, and immune cell infiltration and contributes to the establishment of immunologically 'cold' conditions. Therefore, there is an urgent need to unravel the complexity of the TME that promotes PDAC progression and decipher the mechanisms of pancreatic tumors' resistance to immunotherapy. In this review, we provide an overview of the major cellular and non-cellular components of PDAC TME, as well as their biological interplays. We also discuss the current state of PDAC therapeutic treatments and focus on ongoing and future immunotherapy efforts and multimodal treatments aiming at remodeling the TME to improve therapeutic efficacy.

Posttransplant complications: molecular mechanisms and therapeutic interventions

Posttransplantation complications pose a major challenge to the long-term survival and quality of life of organ transplant recipients. These complications encompass immune-mediated complications, infectious complications, metabolic complications, and malignancies, with each type influenced by various risk factors and pathological mechanisms. The molecular mechanisms underlying posttransplantation complications involve a complex interplay of immunological, metabolic, and oncogenic processes, including innate and adaptive immune activation, immunosuppressant side effects, and viral reactivation. Here, we provide a comprehensive overview of the clinical features, risk factors, and molecular mechanisms of major posttransplantation complications. We systematically summarize the current understanding of the immunological basis of allograft rejection and graft-versus-host disease, the metabolic dysregulation associated with immunosuppressive agents, and the role of oncogenic viruses in posttransplantation malignancies. Furthermore, we discuss potential prevention and intervention strategies based on these mechanistic insights, highlighting the importance of optimizing immunosuppressive regimens, enhancing infection prophylaxis, and implementing targeted therapies. We also emphasize the need for future research to develop individualized complication control strategies under the guidance of precision medicine, ultimately improving the prognosis and quality of life of transplant recipients.

Exploring potential roles of long non-coding RNAs in cancer immunotherapy: a comprehensive review

Cancer treatment has long been fraught with challenges, including drug resistance, metastasis, and recurrence, making it one of the most difficult diseases to treat effectively. Traditional therapeutic approaches often fall short due to their inability to target cancer stem cells and the complex genetic and epigenetic landscape of tumors. In recent years, cancer immunotherapy has revolutionized the field, offering new hope and viable alternatives to conventional treatments. A particularly promising area of research focuses on non-coding RNAs (ncRNAs), especially long non-coding RNAs (lncRNAs), and their role in cancer resistance and the modulation of signaling pathways. To address these challenges, we performed a comprehensive review of recent studies on lncRNAs and their impact on cancer immunotherapy. Our review highlights the crucial roles that lncRNAs play in affecting both innate and adaptive immunity, thereby influencing the outcomes of cancer treatments. Key observations from our review indicate that lncRNAs can modify the tumor immune microenvironment, enhance immune cell infiltration, and regulate cytokine production, all of which contribute to tumor growth and resistance to therapies. These insights suggest that lncRNAs could serve as potential targets for precision medicine, opening up new avenues for developing more effective cancer immunotherapies. By compiling recent research on lncRNAs across various cancers, this review aims to shed light on their mechanisms within the tumor immune microenvironment.

The nuclear export protein XPO1 provides a peptide ligand for natural killer cells

XPO1 (Exportin-1/CRM1) is a nuclear export protein that is frequently overexpressed in cancer and functions as a driver of oncogenesis. Currently small molecules that target XPO1 are being used in the clinic as anticancer agents. We identify XPO1 as a target for natural killer (NK) cells. Using immunopeptidomics, we have identified a peptide derived from XPO1 that can be recognized by the activating NK cell receptor KIR2DS2 in the context of human leukocyte antigen-C. The peptide can be endogenously processed and presented to activate NK cells specifically through this receptor. Although high XPO1 expression in cancer is commonly associated with a poor prognosis, we show that the outcome of specific cancers, such as hepatocellular carcinoma, can be substantially improved if there is concomitant evidence of NK cell infiltration. We thus identify XPO1 as a bona fide tumor antigen recognized by NK cells that offers an opportunity for a personalized approach to NK cell therapy for solid tumors.

Biologically-informed Killer cell immunoglobulin-like receptor (KIR) gene annotation tool

Natural killer (NK) cells are essential components of the innate immune system, with their activity significantly regulated by Killer cell Immunoglobulin-like Receptors (KIRs). The diversity and structural complexity of KIR genes present significant challenges for accurate genotyping, essential for understanding NK cell functions and their implications in health and disease. Traditional genotyping methods struggle with the variable nature of KIR genes, leading to inaccuracies that can impede immunogenetic research. These challenges extend to high-quality phased assemblies, which have been recently popularized by the Human Pangenome Consortium. This paper introduces BAKIR (Biologically-informed Annotator for KIR locus), a tailored computational tool designed to overcome the challenges of KIR genotyping and annotation on high-quality, phased genome assemblies. BAKIR aims to enhance the accuracy of KIR gene annotations by structuring its annotation pipeline around identifying key functional mutations, thereby improving the identification and subsequent relevance of gene and allele calls. It uses a multi-stage mapping, alignment, and variant calling process to ensure high-precision gene and allele identification, while also maintaining high recall for sequences that are significantly mutated or truncated relative to the known allele database. BAKIR has been evaluated on a subset of the HPRC assemblies, where BAKIR was able to improve many of the associated annotations and call novel variants. BAKIR is freely available on GitHub, offering ease of access and use through multiple installation methods, including pip, conda, and singularity container, and is equipped with a user-friendly command-line interface, thereby promoting its adoption in the scientific community.

The basic biology of NK cells and its application in tumor immunotherapy

Natural Killer (NK) cells play a crucial role as effector cells within the tumor immune microenvironment, capable of identifying and eliminating tumor cells through the expression of diverse activating and inhibitory receptors that recognize tumor-related ligands. Therefore, harnessing NK cells for therapeutic purposes represents a significant adjunct to T cell-based tumor immunotherapy strategies. Presently, NK cell-based tumor immunotherapy strategies encompass various approaches, including adoptive NK cell therapy, cytokine therapy, antibody-based NK cell therapy (enhancing ADCC mediated by NK cells, NK cell engagers, immune checkpoint blockade therapy) and the utilization of nanoparticles and small molecules to modulate NK cell anti-tumor functionality. This article presents a comprehensive overview of the latest advances in NK cell-based anti-tumor immunotherapy, with the aim of offering insights and methodologies for the clinical treatment of cancer patients.

Cracking the Codes behind Cancer Cells' Immune Evasion

Immune evasion is a key phenomenon in understanding tumor recurrence, metastasis, and other critical steps in tumor progression. The tumor microenvironment (TME) is in constant flux due to the tumor's ability to release signals that affect it, while immune cells within it can impact cancer cell behavior. Cancer cells undergo several changes, which can change the enrichment of different immune cells and modulate the activity of existing immune cells in the tumor microenvironment. Cancer cells can evade immune surveillance by downregulating antigen presentation or expressing immune checkpoint molecules. High levels of tumor-infiltrating lymphocytes (TILs) correlate with better outcomes, and robust immune responses can control tumor growth. On the contrary, increased enrichment of Tregs, myeloid-derived suppressor cells, and M2-like anti-inflammatory macrophages can hinder effective immune surveillance and predict poor prognosis. Overall, understanding these immune evasion mechanisms guides therapeutic strategies. Researchers aim to modulate the TME to enhance immune surveillance and improve patient outcomes. In this review article, we strive to summarize the composition of the tumor immune microenvironment, factors affecting the tumor immune microenvironment (TIME), and different therapeutic modalities targeting the immune cells. This review is a first-hand reference to understand the basics of immune surveillance and immune evasion.

The Microenvironment of Solid Tumors: Components and Current Challenges of Tumor-on-a-Chip Models

Solid tumors represent the most common type of cancer in humans and are classified into sarcomas, lymphomas, and carcinomas based on the originating cells. Among these, carcinomas, which arise from epithelial and glandular cells lining the body's tissues, are the most prevalent. Around the world, a significant increase in the incidence of solid tumors is observed during recent years. In this context, efforts to discover more effective cancer treatments have led to a deeper understanding of the tumor microenvironment (TME) and its components. Currently, the interactions between cancer cells and elements of the TME are being intensely investigated. Remarkable progress in research is noted, largely owing to the development of advanced in vitro models, such as tumor-on-a-chip models that assist in understanding and ultimately discovering new effective treatments for a specific type of cancer. The purpose of this article is to provide a review of the TME and cancer cell components, along with the advances on tumor-on-a-chip models designed to mimic tumors, offering a perspective on the current state of the art. Recent studies using this kind of microdevices that reproduce the TME have allowed a better understanding of the cancer and its treatments. Nevertheless, current applications of this technology present some limitations that must be overcome to achieve a broad application by researchers looking for a deeper knowledge of cancer and new strategies to improve current therapies.

mTOR Signaling Promotes Rapid m6A mRNA Methylation to Regulate NK-Cell Activation and Effector Functions

NK cells can be rapidly activated in response to cytokines during host defense against malignant cells or viral infection. However, it remains unclear what mechanisms precisely and rapidly regulate the expression of a large number of genes involved in activating NK cells. In this study, we discovered that NK-cell N6-methyladenosine (m6A) methylation levels were rapidly upregulated upon short-term NK-cell activation and were repressed in the tumor microenvironment (TME). Deficiency of methyltransferase-like 3 (METTL3) or METTL14 moderately influenced NK-cell homeostasis, while double-knockout of METTL3/14 more significantly impacted NK-cell homeostasis, maturation, and antitumor immunity. This suggests a cooperative role of METTL3 and METTL14 in regulating NK-cell development and effector functions. Using methylated RNA immunoprecipitation sequencing, we demonstrated that genes involved in NK-cell effector functions, such as Prf1 and Gzmb, were directly modified by m6A methylation. Furthermore, inhibiting mTOR complex 1 activation prevented m6A methylation levels from increasing when NK cells were activated, and this could be restored by S-adenosylmethionine supplementation. Collectively, we have unraveled crucial roles for rapid m6A mRNA methylation downstream of the mTOR complex 1-S-adenosylmethionine signal axis in regulating NK-cell activation and effector functions.

HPK1 Dysregulation-Associated NK Cell Dysfunction and Defective Expansion Promotes Metastatic Melanoma Progression

Distant metastasis, the leading cause of cancer death, is efficiently kept in check by immune surveillance. Studies have uncovered peripheral natural killer (NK) cells as key antimetastatic effectors and their dysregulation during metastasis. However, the molecular mechanism governing NK cell dysfunction links to metastasis remains elusive. Herein, MAP4K1 encoding HPK1 is aberrantly overexpressed in dysfunctional NK cells in the periphery and the metastatic site. Conditional HPK1 overexpression in NK cells suffices to exacerbate melanoma lung metastasis but not primary tumor growth. Conversely, MAP4K1-deficient mice are resistant to metastasis and further protected by combined immune-checkpoint inhibitors. Mechanistically, HPK1 restrains NK cell cytotoxicity and expansion via activating receptors. Likewise, HPK1 limits human NK cell activation and associates with melanoma NK cell dysfunction couples to TGF-β1 and patient response to immune checkpoint therapy. Thus, HPK1 is an intracellular checkpoint controlling NK-target cell responses, which is dysregulated and hijacked by tumors during metastatic progression.

Recent advancements of hydrogels in immunotherapy: Breast cancer treatment

Breast cancer is the most prevalent cancer among women and the leading cause of cancer-related deaths in this population. Recent advances in Immunotherapy, or combined immunotherapy, offering a more targeted and less toxic approach, expand the survival rate of patients more than conventional treatment. Notably, hydrogels, a versatile platform provided promising avenues to combat breast cancer in preclinical studies and extended to clinical practices. With advantages such as the alternation of tumor microenvironment, immunomodulation, targeted delivery of therapeutic agents, and their sustained release at specific sites of interest, hydrogels can potentially be used for the treatment of breast cancer. This review highlights the advantages, mechanisms of action, stimuli-responsiveness properties, and recent advancements of hydrogels for treating breast cancer immunotherapy. Moreover, post-treatment and its clinical translations are discussed in this review. The integration of hydrogels in immunotherapy strategies may pave the way for more effective, personalized, and patient-friendly approaches to combat breast cancer, ultimately contributing to a brighter future for breast cancer patients.

The interaction between NK cells and ILC cells and their subsets in atopic dermatitis patients with and without dupilumab therapy

BACKGROUND

Natural killer cells (NK) and innate lymphoid cells with their subsets (ILC) are part of the innate immune system.

OBJECTIVE

The aim is to evaluate how NK cells and ILC cells interact in atopic dermatitis (AD) patients (with and without dupilumab therapy) compared to control group.

MATERIALS AND METHODS

Complete dermatological examination was performed in all patients included in the study (19 AD patients with dupilumab, 17 AD patients without dupilumab). Surface molecules expressed on NK cells and ILC cells were analyzed by flow cytometry. The association between NK cells and total ILC cells, ILC-1, ILC-2, ILC-3, NCR+ILC3, NCR-ILC3 were compared in AD patients and in the control group. The non-parametric Spearman's rank correlation coefficient was used for this statistical analysis. We evaluated the association of parameters with AD severity at the time of treatment.Non-parametric Mann-Whitney, Kolmogorov-Smirnov tests were used.

RESULTS

We confirmed the higher association between NK cells and total ILC cells in AD patients without dupilumab therapy (in 30.3 %) and in healthy controls (in 27.2 %); this association is low in AD patients with dupilumab therapy (in 0.1 %). The higher association was confirmed between NK cells and ILCs subsets only in AD patients without dupilumab therapy; in these patients the highest association was confirmed between NK cells and ILC-2 cells (in 38.6 %). No statistically significant difference in the count of NK cells and ILC cells was found between mild and moderate form of AD patients treated with dupilumab.

CONCLUSION

Targeting these cell types or the cytokines they produce could represent potential therapeutic strategies for controlling inflammation and alleviating symptoms in AD patients.

Beyond CAR T cells: exploring alternative cell sources for CAR-like cellular therapies

Chimeric antigen receptor (CAR)-T cell therapy has led to remarkable clinical outcomes in the treatment of hematological malignancies. However, challenges remain, such as limited infiltration into solid tumors, inadequate persistence, systemic toxicities, and manufacturing insufficiencies. The use of alternative cell sources for CAR-based therapies, such as natural killer cells (NK), macrophages (MΦ), invariant Natural Killer T (iNKT) cells, γδT cells, neutrophils, and induced pluripotent stem cells (iPSC), has emerged as a promising avenue. By harnessing these cells' inherent cytotoxic mechanisms and incorporating CAR technology, common CAR-T cell-related limitations can be effectively mitigated. We herein present an overview of the tumoricidal mechanisms, CAR designs, and manufacturing processes of CAR-NK cells, CAR-MΦ, CAR-iNKT cells, CAR-γδT cells, CAR-neutrophils, and iPSC-derived CAR-cells, outlining the advantages, limitations, and potential solutions of these therapeutic strategies.

Cell-to-cell signaling in cell populations with large cell size variability

Sizes of multiple cells vary when they communicate with each other. Differences in cell size result in variations in the cell surface area and volume, as well as the number of enzymes and receptors involved in signal transduction. Although heterogeneity in cell size may inhibit uniformity in signaling, cell-to-cell signaling is still possible. The outcome when cell size changes to an extreme degree remains unclear. Hence, we inhibited cell division in Dictyostelium cells, a model organism for signal transduction, to gain insights into the consequences of extreme cell size variations. Measurements of cell signals in this population using fluorescence microscopy indicated that the giant cells can communicate with normal-sized cells by suppressing the signal level. Simulations of signal transduction based on the FitzHugh-Nagumo model also suggested similar results. Our findings suggest that signaling mechanism homogenizes cell-to-cell signaling in response to cell size.

The Spectrum of CAR Cellular Effectors: Modes of Action in Anti-Tumor Immunity

Chimeric antigen receptor-T cells have spearheaded the field of adoptive cell therapy and have shown remarkable results in treating hematological neoplasia. Because of the different biology of solid tumors compared to hematological tumors, response rates of CAR-T cells could not be transferred to solid entities yet. CAR engineering has added co-stimulatory domains, transgenic cytokines and switch receptors to improve performance and persistence in a hostile tumor microenvironment, but because of the inherent cell type limitations of CAR-T cells, including HLA incompatibility, toxicities (cytokine release syndrome, neurotoxicity) and high costs due to the logistically challenging preparation process for autologous cells, the use of alternative immune cells is gaining traction. NK cells and γδ T cells that do not need HLA compatibility or macrophages and dendritic cells with additional properties such as phagocytosis or antigen presentation are increasingly seen as cellular vehicles with potential for application. As these cells possess distinct properties, clinicians and researchers need a thorough understanding of their peculiarities and commonalities. This review will compare these different cell types and their specific modes of action seen upon CAR activation.

Progression of m6A in the tumor microenvironment: hypoxia, immune and metabolic reprogramming

Recently, N6-methyladenosine (m6A) has aroused widespread discussion in the scientific community as a mode of RNA modification. m6A comprises writers, erasers, and readers, which regulates RNA production, nuclear export, and translation and is very important for human health. A large number of studies have found that the regulation of m6A is closely related to the occurrence and invasion of tumors, while the homeostasis and function of the tumor microenvironment (TME) determine the occurrence and development of tumors to some extent. TME is composed of a variety of immune cells (T cells, B cells, etc.) and nonimmune cells (tumor-associated mesenchymal stem cells (TA-MSCs), cancer-associated fibroblasts (CAFs), etc.). Current studies suggest that m6A is involved in regulating the function of various cells in the TME, thereby affecting tumor progression. In this manuscript, we present the composition of m6A and TME, the relationship between m6A methylation and characteristic changes in TME, the role of m6A methylation in TME, and potential therapeutic strategies to provide new perspectives for better treatment of tumors in clinical work.

Sijunzi decoction enhances sensitivity of colon cancer cells to NK cell destruction by modulating P53 expression

ETHNOPHARMACOLOGICAL RELEVANCE

Sijunzi Decoction (SJZD), a traditional Chinese herbal remedy, is frequently employed in the treatment of various cancers, including colon cancer. Previous research suggests that SJZD plays a pivotal role in modulating the immune system and enhancing immunity against tumors. However, the precise role of SJZD in combating colon cancer and its potential molecular functions in regulating natural killer cells remain elusive.

AIMS OF THE STUDY

To elucidate the potential mechanism underlying the anticolon cancer effects of SJZD in synergy with natural killer (NK) cells through both in vivo and in vitro experiments.

MATERIALS AND METHODS

In vivo experiments: A subcutaneous tumor mouse model of colon cancer and in vivo NK cell depletion experiments were conducted to observe the anticolon cancer effects of SJZD. Flow cytometry assessed immune cell depletion in mouse spleens, while immunohistochemical (IHC) staining detected the expression of apoptotic genes in tumor tissues. In vitro experiments: The mechanism by which SJZD regulates the sensitization of colon cancer cells to NK cells was investigated using real-time polymerase chain reaction (RT-PCR), western blotting (WB), and co-culture experiments with NK cells.

RESULTS

Sijunzi Decoction (SJZD) significantly impeded tumor growth in mice; however, NK cell depletion markedly attenuated the tumor-suppressive effect of SJZD. Immunohistochemical (IHC) results indicated that SJZD increased the expression of P53, death receptor 4 (DR4), and death receptor 5 (DR5) in tumor tissues. In vitro experiments, 24 h SJZD-pretreated colon cancer cells showed a substantial elevation in P53, DR4, and DR5 levels, and the activity of colon cancer cells significantly diminished after co-culture with NK cells. These effects of SJZD were reversed with the addition of the P53 inhibitor pifithrin-α (PFT-α), resulting in reduced inhibition of colon cancer cells by NK cells.

CONCLUSION

SJZD enhances the levels of DR4 and DR5 through the modulation of P53 expression, consequently increasing the sensitivity of colon cancer cells to NK cell-mediated killing. These findings provide a theoretical foundation for the clinical application of SJZD in patients with colon cancer. In this study, we first investigated the effect of SJZD on subcutaneous tumor growth in mice with colon cancer using in vivo assays and assessed the impact of NK cells on the anticolon cancer effect of SJZD in vivo through NK cell depletion. In vitro experiments were conducted to explore the potential mechanism of action of SJZD in NK cell-mediated anticolon cancer effects.

The cGAS/STING Pathway-A New Potential Biotherapeutic Target for Gastric Cancer?

Gastric cancer ranks among the top five deadliest tumors worldwide, both in terms of prevalence and mortality rates. Despite mainstream treatments, the efficacy in treating gastric cancer remains suboptimal, underscoring the urgency for novel therapeutic approaches. The elucidation of tumor immunosuppressive microenvironments has shifted focus towards cancer biotherapeutics, which leverage the patient's immune system or biologics to target tumor cells. Biotherapy has emerged as a promising alternative for tumors resistant to traditional chemotherapy, radiation, and immunotherapy. Central to this paradigm is the cGAS-STING pathway, a pivotal component of the innate immune system. This pathway recognizes aberrant DNA, such as that from viral infections or tumor cells, and triggers an immune response, thereby reshaping the immunosuppressive tumor microenvironment into an immune-stimulating milieu. In the context of gastric cancer, harnessing the cGAS-STING pathway holds significant potential for biotherapeutic interventions. This review provides a comprehensive overview of the latest research on cGAS-STING in gastric cancer, including insights from clinical trials involving STING agonists. Furthermore, it assesses the prospects of targeting the cGAS-STING pathway as a novel biotherapeutic strategy for gastric cancer.

TLR Agonists Modify NK Cell Activation and Increase Its Cytotoxicity in Acute Lymphoblastic Leukemia

Natural killer (NK) cells play a crucial role in innate immunity, particularly in combating infections and tumors. However, in hematological cancers, NK cells often exhibit impaired functions. Therefore, it is very important to activate its endosomal Toll-like receptors (TLRs) as a potential strategy to restore its antitumor activity. We stimulated NK cells from the peripheral blood mononuclear cells from children with acute lymphoblastic leukemia and NK cells isolated, and the NK cells were stimulated with specific TLR ligands (Poly I:C, Imiquimod, R848, and ODN2006) and we evaluated changes in IFN-γ, CD107a, NKG2D, NKp44 expression, Granzyme B secretion, cytokine/chemokine release, and cytotoxic activity. Results revealed that Poly I:C and Imiquimod enhanced the activation of both immunoregulatory and cytotoxic NK cells, increasing IFN-γ, CD107a, NKG2D, and NKp44 expression. R848 activated immunoregulatory NK cells, while ODN2006 boosted CD107a, NKp44, NKG2D, and IFN-γ secretion in cytotoxic NK cells. R848 also increased the secretion of seven cytokines/chemokines. Importantly, R848 and ODN 2006 significantly improved cytotoxicity against leukemic cells. Overall, TLR stimulation enhances NK cell activation, suggesting TLR8 (R848) and TLR9 (ODN 2006) ligands as promising candidates for antitumor immunotherapy.

A Critical Role of Culture Medium Selection in Maximizing the Purity and Expansion of Natural Killer Cells

Natural killer (NK) cells hold promise in cancer treatment due to their ability to spontaneously lyse cancer cells. For clinical use, high quantities of pure, functional NK cells are necessary. Combining adherence-based isolation with specialized media showed the unreliability of the isolation method, but demonstrated the superiority of the NK MACS® medium, particularly in suboptimal conditions. Neither human pooled serum, fetal calf serum (FCS), human platelet lysate, nor chemically defined serum replacement could substitute human AB serum. Interleukin (IL-)2, IL-15, IL-21, and combined CD2/NKp46 stimulation were assessed. IL-21 and CD2/NKp46 stimulation increased cytotoxicity, but reduced NK cell proliferation. IL-15 stimulation alone achieved the highest proliferation, but the more affordable IL-2 performed similarly. The RosetteSep™ human NK cell enrichment kit was effective for isolation, but the presence of peripheral blood mononuclear cells (PBMCs) in the culture enhanced NK cell proliferation, despite similar expression levels of CD16, NKp46, NKG2D, and ICAM-1. In line with this, purified NK cells cultured in NK MACS® medium with human AB serum and IL-2 demonstrated high cytotoxicity against primary glioblastoma stem cells.

From pancreas to lungs: The role of immune cells in severe acute pancreatitis and acute lung injury

BACKGROUND

Severe acute pancreatitis (SAP) is a potentially lethal inflammatory pancreatitis condition that is usually linked to multiple organ failure. When it comes to SAP, the lung is the main organ that is frequently involved. Many SAP patients experience respiratory failure following an acute lung injury (ALI). Clinicians provide insufficient care for compounded ALI since the underlying pathophysiology is unknown. The mortality rate of SAP patients is severely impacted by it.

OBJECTIVE

The study aims to provide insight into immune cells, specifically their roles and modifications during SAP and ALI, through a comprehensive literature review. The emphasis is on immune cells as a therapeutic approach for treating SAP and ALI.

FINDINGS

Immune cells play an important role in the complicated pathophysiology ofSAP and ALI by maintaining the right balance of pro- and anti-inflammatory responses. Immunomodulatory drugs now in the market have low thepeutic efficacy because they selectively target one immune cell while ignoring immune cell interactions. Accurate management of dysregulated immune responses is necessary. A critical initial step is precisely characterizing the activity of the immune cells during SAP and ALI.

CONCLUSION

Given the increasing incidence of SAP, immunotherapy is emerging as a potential treatment option for these patients. Interactions among immune cells improve our understanding of the intricacy of concurrent ALI in SAP patients. Acquiring expertise in these domains will stimulate the development of innovative immunomodulation therapies that will improve the outlook for patients with SAP and ALI.

Combining single-cell and bulk RNA sequencing, NK cell marker genes reveal a prognostic and immune status in pancreatic ductal adenocarcinoma

The NK cell is an important component of the tumor microenvironment of pancreatic ductal adenocarcinoma (PDAC), also plays a significant role in PDAC development. This study aimed to explore the relationship between NK cell marker genes and prognosis, immune response of PDAC patients. By scRNA-seq data, we found the proportion of NK cells were significantly downregulated in PDAC and 373 NK cell marker genes were screened out. By TCGA database, we enrolled 7 NK cell marker genes to construct the signature for predicting prognosis in PDAC patients. Cox analysis identified the signature as an independent factor for pancreatic cancer. Subsequently, the predictive power of signature was validated by 6 GEO datasets and had an excellent evaluation. Our analysis of relationship between the signature and patients' immune status revealed that the signature has a strong correlation with immunocyte infiltration, inflammatory reaction, immune checkpoint inhibitors (ICIs) response. The NK cell marker genes are closely related to the prognosis and immune capacity of PDAC patients, and they have potential value as a therapeutic target.

Natural killer cells in cancer immunotherapy

Natural killer (NK) cells, as innate lymphocytes, possess cytotoxic capabilities and engage target cells through a repertoire of activating and inhibitory receptors. Particularly, natural killer group 2, member D (NKG2D) receptor on NK cells recognizes stress-induced ligands-the MHC class I chain-related molecules A and B (MICA/B) presented on tumor cells and is key to trigger the cytolytic response of NK cells. However, tumors have developed sophisticated strategies to evade NK cell surveillance, which lead to failure of tumor immunotherapy. In this paper, we summarized these immune escaping strategies, including the downregulation of ligands for activating receptors, upregulation of ligands for inhibitory receptors, secretion of immunosuppressive compounds, and the development of apoptosis resistance. Then, we focus on recent advancements in NK cell immune therapies, which include engaging activating NK cell receptors, upregulating NKG2D ligand MICA/B expression, blocking inhibitory NK cell receptors, adoptive NK cell therapy, chimeric antigen receptor (CAR)-engineered NK cells (CAR-NK), and NKG2D CAR-T cells, especially several vaccines targeting MICA/B. This review will inspire the research in NK cell biology in tumor and provide significant hope for improving cancer treatment outcomes by harnessing the potent cytotoxic activity of NK cells.

LINC00665 promotes the progression and immune evasion of lung cancer by facilitating the translation of TCF7 protein through dependence on IRES

OBJECTIVE

To investigate the influence of LINC00665 on the development and immune evasion of lung cancer.

METHODS

Tumor tissues and corresponding adjacent tissues were collected from 84 lung cancer patients, categorized into non-metastatic (n = 58) and metastatic (n = 26) groups. LINC00665 expression in lung cancer and metastatic lung cancer tissues was assessed via qRT-PCR. Pearson correlation analysis was conducted to examine the correlation between LINC00665 and immune-modulating cytokines (TGF-β, IL-10, IL-1β, IFN-γ, IL-2, TNF-α). A549 and H1299 cells, with relatively high LINC00665 expression, were used for in vitro studies. Cells were transfected with LINC00665-targeting shRNA, and changes in proliferation, apoptosis, migration, invasion, and NK cell cytotoxicity were assessed. Downstream molecular mechanisms of LINC00665 were investigated using GEO database analysis, highlighting the association with HHLA2. LINC00665's role in promoting HHLA2 expression via binding with TCF7 was explored. In low LINC00665-expressing A549/H1299 cells, overexpression of HHLA2 was performed to evaluate effects on malignant behavior and NK cell sensitivity. A xenograft model was established for in vivo validation through tumor volume and weight measurements, Ki-67 immunoreactivity analysis, and flow cytometry analysis of CD107a + NK cells.

RESULTS

LINC00665, TCF7 mRNA, and HHLA2 mRNA expression levels were significantly higher in lung cancer tissues than adjacent tissues, with non-metastatic lung cancer showing higher expression than metastatic lung cancer. In metastatic lung cancer, LINC00665 positively correlated with immune-suppressive cytokines (TGF-β, IL-10, IL-1β) and negatively correlated with anti-tumor cytokines (IFN-γ, IL-2, TNF-α). LINC00665 knockdown significantly inhibited lung cancer cell growth and metastasis, promoting sensitivity to NK cells. Further analysis revealed that LINC00665 recruits transcription factor TCF7 to upregulate HHLA2 expression in lung cancer cells, thereby facilitating lung cancer development and immune escape.

CONCLUSION

LINC00665, through recruitment of TCF7 and upregulation of HHLA2, inhibits NK cell cytotoxicity, promoting the development and immune evasion of lung cancer.

Active juvenile systemic lupus erythematosus is associated with distinct NK cell transcriptional and phenotypic alterations

While adaptive immune responses have been studied extensively in SLE (systemic lupus erythematosus), there is limited and contradictory evidence regarding the contribution of natural killer (NK) cells to disease pathogenesis. There is even less evidence about the role of NK cells in the more severe phenotype with juvenile-onset (J)SLE. In this study, analysis of the phenotype and function of NK cells in a large cohort of JSLE patients demonstrated that total NK cells, as well as perforin and granzyme A expressing NK cell populations, were significantly diminished in JSLE patients compared to age- and sex-matched healthy controls. The reduction in NK cell frequency was associated with increased disease activity, and transcriptomic analysis of NK populations from active and low disease activity JSLE patients versus healthy controls confirmed that disease activity was the main driver of differential NK cell gene expression. Pathway analysis of differentially expressed genes revealed an upregulation of interferon-α responses and a downregulation of exocytosis in active disease compared to healthy controls. Further gene set enrichment analysis also demonstrated an overrepresentation of the apoptosis pathway in active disease. This points to increased propensity for apoptosis as a potential factor contributing to NK cell deficiency in JSLE.

The effects of postoperative targeted immunotherapy on peripheral blood cytokines and immune cell profile in lung cancer patients

Objective

Cytokines and cell subsets are important components of the tumor microenvironment. Previous research has revealed that there are differences in cytokines and cell subsets in the peripheral blood of lung cancer (LCA) patients before and after eradication. The purpose of this study is to explore the monitoring value of cytokines and cellular subpopulations as biomarkers in post-immunotherapy monitoring of patients with LCA after surgery.

Methods

We conducted a case-control study using double-antibody sandwich magnetic microsphere flow cytometry with immunofluorescence technology and fluorescent monoclonal antibody multiparameter flow cytometry to detect differences in peripheral blood cytokines and cell subsets between LCA patients after immunotherapy and healthy controls.

Results

Our research results show that there are differences in the levels of IL-4, IL-6, IL-10, IL-17, IFN-γ, TNF-α in the peripheral blood of LCA patients (n=70) after immunotherapy compared to the healthy controls (n=55) (P<0.05), and there are differences in 10 cell subgroups including DP T Cells, AT cells, and NLR in the peripheral blood compared to the healthy controls (n=35) (P<0.05). Further analysis revealed significant differences in the detection data of IL-6, IL-10, IFN-γ, CD56dim NK cells, Total B cells, Total NE cells, CD15+M cells, and NLR between LCA deceased patients (n=25) and LCA surviving patients (n=27) during the same period (P<0.05). The continuous monitoring of cytokines and cell subsets is far more valuable than a single-time test, as abnormal fluctuations in the data of cytokines and cell subsets are often associated with poor prognosis. In addition, IL-6 and NLR showed the strongest discriminative ability between postoperative immunotherapy-treated LCA patients and healthy controls, with AUC values of 0.840 and 0.822, respectively. There was a significant association between IFN-γ and distant metastasis in LCA (P<0.05), as well as between CD56dim NK cells and lymph node infiltration (P<0.05).

Conclusion

This research results support peripheral blood cytokines and cell subsets as biomarkers for monitoring the postoperative immune status and predicting the prognosis of LCA patients after immunotherapy. The continuous monitoring of cytokines and cell subsets is far more valuable than a single-time detection.