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High-grade serous ovarian cancers (HGSOCs) likely consist of poorly differentiated stem-like cells (PDSLCs) and differentiated tumor cells. Conventional therapeutics are incapable of completely eradicating PDSLCs, contributing to disease progression and tumor relapse. Primary NK cells are known to effectively lyse PDSLCs, but they exhibit low or minimal cytotoxic potential against well-differentiated tumors. We have introduced and discussed the characteristics of super-charged NK (sNK) cells in this review. sNK cells, in comparison to primary NK cells, exhibit a significantly higher capability for the direct killing of both PDSLCs and well-differentiated tumors. In addition, sNK cells secrete significantly higher levels of cytokines, especially those known to induce the differentiation of tumors. In addition, we propose that a combination of sNK and chemotherapy could be one of the most effective strategies to eliminate the heterogeneous population of ovarian tumors; sNK cells can lyse both PDSLCs and well-differentiated tumors, induce the differentiation of PDSLCs, and could be used in combination with chemotherapy to target both well-differentiated and NK-induced differentiated tumors.

The ability of cells of the immune system to acquire features such as increased longevity and enhanced secondary responses was long thought to be restricted to cells of the adaptive immune system. Natural killer (NK) cells have challenged this notion by demonstrating that they can also gain adaptive features. This has been observed in both humans and mice during infection with cytomegalovirus (CMV). The generation of adaptive NK cells requires antigen-specific recognition of virally infected cells through stimulatory NK receptors. These receptors lack the ability to signal on their own and rather rely on adaptor molecules that contain ITAMs for driving signals. Here, we highlight our understanding of how these receptors influence the production of adaptive NK cells and propose areas in the field that merit further investigation.

Melanoma, recognized as one of the most immunogenic malignancies in humans, holds paramount significance in the realm of immunotherapy. However, the emergence of drug resistance and the occurrence of adverse drug reactions underscore the pressing need to explore increasingly personalized immunotherapeutic modalities. Extracellular Vesicles (EVs), pivotal derivatives of immune cells, assume pivotal roles by encapsulating proteins, lipids, and nucleic acids within bilayer lipid structures, thereby facilitating targeted delivery to other immune cells. This orchestrated process orchestrates critical functions including antigen presentation, immune modulation, and the induction of apoptosis in tumor cells. A burgeoning body of evidence underscores the vast therapeutic potential of EVs in melanoma treatment. This comprehensive review aims to delineate the roles of EVs derived from immune cells such as dendritic cells, natural killer cells, macrophages, and T cells in the context of melanoma patients, thereby furnishing invaluable insights for the future direction of melanoma immunotherapy. [ABSTRACT FROM AUTHOR]

Background: Macrophage activation syndrome (MAS) is an acquired form of hemo phagocytic lymphohistiocytosis (HLH) and is usually associated with infections, autoimmune, auto inflammatory syndromes and malignancies. Case details: A 14 year old girl presented with sub-acute onset of fever with lymphadenopathy, pancytopenia,high ferritin values and a falling erythrocyte sedimentation rate. She was evaluated with relevant laboratory tests that was suggestive of systemic Lupus erythematosus and associated macrophage activation syndrome She recovered with immunosuppressive therapy and other supportive care. Conclusion: There is a need for a high index of suspicion of occult MAS and MAS in patients with systemic lupus erythematosus as it may be an initial presentation. Delay in diagnosis and initiation of treatment can lead to a higher mortality. [ABSTRACT FROM AUTHOR]

In both humans and mice, natural killer (NK) cells are important lymphocytes of the innate immune system. They are often considered pro-inflammatory effector cells but may also have a regulatory or pro-resolving function by switching their cytokine profile towards the production of anti-inflammatory cytokines, including interleukin-10 (IL-10) and transforming growth factor-p, and by killing pro-inflammatory immune cells. Here, the role of NK cells in the resolution of malaria lung pathology was studied. Malaria complications, such as malaria-associated acute respiratory distress syndrome (MA-ARDS), are often lethal despite the rapid and efficient killing of Plasmodium parasites with antimalarial drugs. Hence, studying the resolution and healing mechanisms involved in the recovery from these complications could be useful to develop adjunctive treatments. Treatment of Plasmodium berghei NK65-infected C57BL/6 mice with a combination of artesunate and chloroquine starting at the appearance of symptoms was used as a model to study the resolution of MA-ARDS. The role of NK cells was studied using anti-NK1.1 depletion antibodies and NK cell-deficient mice. Using both methods, NK cells were found to be dispensable in the development of MA-ARDS, as shown previously. In contrast, NK cells were crucial in the initiation of resolution upon antimalarial treatment, as survival was significantly decreased in the absence of NK cells. Considerably increased IL-10 expression by NK cells suggested an antiinflammatory and pro-resolving phenotype. Despite the increase in Il10 expression in the NK cells, inhibition of the IL-10/IL-10R axis using anti-IL10R antibodies had no effect on the resolution for MA-ARDS, suggesting that the pro-resolving effect of NK cells cannot solely be attributed to their IL-10 production. In conclusion, NK cells contribute to the resolution of experimental MA-ARDS. [ABSTRACT FROM AUTHOR]

Human T cell leukemia virus type 1 (HTLV-1) is the first human oncogenic retrovirus to be discovered and causes two major diseases: a progressive neuro-inflammatory disease, termed HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP), and an aggressive malignancy of T lymphocytes known as adult T cell leukemia (ATL). Innate and acquired immune responses play pivotal roles in controlling the status of HTLV-1-infected cells and such, the outcome of HTLV-1 infection. Natural killer cells (NKCs) are the effector cells of the innate immune system and are involved in controlling viral infections and several types of cancers. The ability of NKCs to trigger cytotoxicity to provide surveillance against viruses and cancer depends on the balance between the inhibitory and activating signals. In this review, we will discuss NKC function and the alterations in the frequency of these cells in HTLV-1 infection. [ABSTRACT FROM AUTHOR]

Purpose: Although immunotherapy improves outcomes in extensive-stage small-cell lung cancer (ES-SCLC), the search for biomarkers predicting treatment success is crucial. Natural killer (NK) cells are potential indicators in various cancers, however, their precise role in ES-SCLC prognosis remains unclear. Methods: In this retrospective study, 33 patients with ES-SCLC treated with first-line immuno-chemotherapy were enrolled. The peripheral NK cell percentage and its longitudinal dynamics were analyzed using flow cytometry. Progression-free survival (PFS) and overall survival (OS) were calculated as hazard ratio (HR) and compared statistically. Results: The median PFS was better in the group with normal baseline NK cell levels than the low group (7.0 vs. 4.6 months; HR = 0.17; 95% CI 0.07–0.41; P < 0.0001), but there was no association with OS (14.9 vs. 10.3 months; HR = 0.55; 95% CI 0.23–1.31; P = 0.171). Furthermore, the NK cell% for 95.0% of patients increased after immunochemotherapy in the clinical response group (P = 0.0047), which led to a better median PFS (6.3 vs. 2.1 months; HR = 0.23; 95% CI 0.05–0.98; P < 0.0001) and OS (14.9 vs. 5.9 months; HR = 0.20; 95% CI 0.04–1.02; P < 0.0001). Similar trends were observed with NK cell% changes up to disease progression, improving PFS (6.5 vs. 4.3; HR = 0.41; 95% CI 0.12–0.92; P = 0.0049) and OS (17.4 vs. 9.7; HR = 0.42; 95% CI 0.17–1.02; P < 0.0001). Conclusion: In patients with ES-SCLC, the percentage and changes in peripheral NK cells can predict the response to combined immunotherapy and chemotherapy. [ABSTRACT FROM AUTHOR]

Background: Chronic lymphoproliferative disorder of natural killer cells (CLPD-NK) is a rare disease characterized by a persistent increase in NK cells in peripheral blood and is generally asymptomatic. If present, symptoms may include fatigue, B symptoms (fever, night sweats, and unintentional weight loss), autoimmune-associated diseases, splenomegaly, and infection due to neutropenia. Peripheral neuropathy, however, is uncommon with an incidence of 3%. Neurolymphomatosis is a neurological manifestation of non-Hodgkin lymphoma and leukemia in which neurotropic neoplastic cells infiltrate the nerves. Moreover, neurolymphomatosis caused by CLPD-NK is extremely rare, with even fewer cases of autonomic dysfunction. We report a case of neurolymphomatosis associated with CLPD-NK and developed autonomic dysfunction, including orthostatic hypotension and gastrointestinal symptoms. Case presentation: The patient was a 61-year-old male who was referred to our hospital for leukocytosis. He was diagnosed with CLPD-NK; however, was untreated since he had no hepatosplenomegaly, and other systemic symptoms. He later developed numbness in his lower extremities. Cerebral spinal fluid examination revealed a markedly elevated protein level of 140 mg/dL, and contrast-enhanced magnetic resonance imaging showed bilateral L4 and 5 nerve roots with enlargement and contrast effect. An immune-mediated polyradiculoneuropathy was suspected, and he was treated with intravenous methylprednisolone and immunoglobulin followed by oral prednisolone and cyclosporine. Although his symptoms were relieved by the immunotherapy, significant autonomic dysfunction, including intractable diarrhea, decreased sweating, and orthostatic hypotension, appeared. Additionally, tests for onconeuronal antibodies, ganglionic nicotinic acetylcholine receptor (gAChR) antibody, NF155, CNTN1, Caspr1 antibody, and anti-ganglioside antibodies were all negative. A sural nerve biopsy revealed lymphocytic infiltration, and immunohistochemical staining of lymphocytes confirmed the infiltration of NK and T cells. Therefore, a diagnosis of neurolymphomatosis caused by CLPD-NK was made, and chemotherapy led to partial symptom improvement. Conclusions: We experienced a case of pathologically diagnosed neurolymphomatosis with autonomic dysfunction associated with CLPD-NK. In cases of subacute to chronic autonomic dysfunction, paraneoplastic neuropathy, amyloidosis, and autoimmune autonomic ganglionopathy are considered; however neurolymphomatosis caused by CLPD-NK, an important cause of autonomic dysfunction, is not. In difficult to make diagnosis, aggressive nerve biopsy is required. [ABSTRACT FROM AUTHOR]

Patients with microsatellite instability‐high (MSI‐H) colorectal cancer (CRC) have high tumor mutation burden and tumor immunogenicity, exhibiting a higher response rate to immunotherapy and better survival. However, a portion of MSI‐H CRC patients still experience adverse disease outcomes. We aimed to identify the tumor‐autonomous regulators determining these heterogeneous clinical outcomes. The Cancer Genome Atlas (TCGA) dataset was used to identify regulators in MSI‐H CRC patients with unfavorable outcomes. Stable CRC tumor clones expressing targeted regulators were established to evaluate migratory and stemness properties, immune cell vulnerability, and cell‐in‐cell (CIC) structure formation. RNA‐sequencing (RNA‐seq) was used to identify enriched biological pathways in stable CRC tumor clones. Clinicopathological characterization of formalin‐fixed paraffin‐embedded (FFPE) MSI‐H CRC specimens was performed to explore the underlying mechanisms involved. We showed that cancer/testis antigen family 45 member A1 (CT45A1) expression was upregulated in MSI‐H CRC patients with poor survival outcomes. CT45A1‐expressing microsatellite stable (MSS) CRC cells showed enhanced migratory ability. However, CT45A1‐expressing MSI‐H CRC cells, but not MSS CRC cells, showed higher resistance to natural killer (NK) cell cytotoxicity and served as outer cells in homotypic CIC structures, preventing exogenous or therapeutic antibody access to inner CRC cells. Inactivating RHO‐ROCK/MLCK‐MLC2 signaling with small‐molecule inhibitors or short‐hairpin RNAs (shRNAs) targeting myosin light chain kinase (MYLK) abolished NK cell resistance and reduced the outer cell fate of CT45A1‐expressing MSI‐H CRC cells. In MSI‐H CRC patients, CT45A1‐positive tumors exhibited increased MLC2 phosphorylation, increased outer cell fate, and decreased survival. We demonstrated that CT45A1 potentiates the advanced progression of MSI‐H CRC, and targeting MLC2 phosphorylation may enhance immunotherapy efficacy in CT45A1‐positive MSI‐H CRC patients. [ABSTRACT FROM AUTHOR]

Natural Killer (NK) cells are exciting candidates for cancer immunotherapy with potent innate cytotoxicity and distinct advantages over T cells for Chimeric Antigen Receptor (CAR) therapy. Concerns regarding the safety, cost, and scalability of viral vectors has ignited research into non-viral alternatives for gene delivery. This review comprehensively analyses recent advancements and challenges with non-viral genetic modification of NK cells for allogeneic CAR-NK therapies. Non-viral alternatives including electroporation and multifunctional nanoparticles are interrogated with respect to CAR expression and translational responses. Crucially, the link between NK cell biology and design of drug delivery technologies are made, which is essential for development of future non-viral approaches. This review provides valuable insights into the current state of non-viral CAR-NK cell engineering, aimed at realising the full potential of NK cell-based immunotherapies. Non-viral production of "off-the-shelf" CAR-NK cells. 1. NK cells may be purified from donor blood, differentiated from stem cells or produced from immortalised cell lines in the lab. 2. NK-specific CAR design modified from CAR-T designs to include NK transmembrane domains (NKG2D, NKp44), co-stimulatory receptors (e.g., DAP10, 2B4) and NK cell receptors (NKG2D). 3. Non-viral genetic modification of NK cells can include delivery of CAR construct via DNA or mRNA, and knock-in/out of specific genes using gene editing tools (e.g., CRISPR Cas9, transposons). This requires a gene delivery method which may include electroporation, lipid and multifunctional nanoparticles and cell penetrating peptides. The resultant CAR-NK cells are then expanded in vitro and may be delivered as an "off-the-shelf" product to treat multiple patients. [ABSTRACT FROM AUTHOR]

NKG2D is an activating receptor expressed by natural killer (NK) cells and other cytotoxic lymphocytes that plays a pivotal role in the elimination of neoplastic cells through recognition of different stress-induced cell surface ligands (NKG2DL). To employ this mechanism for cancer immunotherapy, we generated NKG2D-engaging bispecific antibodies that selectively redirect immune effector cells to cancer cells expressing the tumor-associated antigen ErbB2 (HER2). NKG2D-specific single chain fragment variable (scFv) antibodies cross-reactive toward the human and murine receptors were derived by consecutive immunization of chicken with the human and murine antigens, followed by stringent screening of a yeast surface display immune library. Four distinct species cross-reactive (sc) scFv domains were selected, and reformatted into a bispecific engager format by linking them via an IgG4 Fc domain to a second scFv fragment specific for ErbB2. The resulting molecules (termed scNKAB-ErbB2) were expressed as disulfide-linked homodimers, and demonstrated efficient binding to ErbB2-positive cancer cells as well as NKG2D-expressing primary human and murine lymphocytes, and NK-92 cells engineered with chimeric antigen receptors derived from human and murine NKG2D (termed hNKAR and mNKAR). Two of the scNKAB-ErbB2 molecules were found to compete with the natural NKG2D ligand MICA, while the other two engagers interacted with an epitope outside of the ligand binding site. Nevertheless, all four tested scNKAB-ErbB2 antibodies were similarly effective in redirecting the cytotoxic activity of primary human and murine lymphocytes as well as hNKAR-NK-92 and mNKAR-NK-92 cells to ErbB2-expressing targets, suggesting that further development of these species cross-reactive engager molecules for cancer immunotherapy is warranted. [ABSTRACT FROM AUTHOR]

Introduction: Pediatric patients with unexplained bone marrow failure (BMF) are often categorized as aplastic anemia (AA). Based on the accepted hypothesis of an auto-immune mechanism underlying AA, immune suppressive therapy (IST) might be effective. However, due to the lack of diagnostic tools to identify immune AA and prognostic markers to predict IST response together with the unequaled curative potential of hematopoietic stem cell transplantation (HSCT), most pediatric severe AA patients are momentarily treated by HSCT if available. Although several studies indicate oligoclonal T-cells with cytotoxic activities towards the hematopoietic stem cells, increasing evidence points towards defective inhibitory mechanisms failing to inhibit auto-reactive T-cells. Methods: We aimed to investigate the role of NK- and B-cells in seven pediatric AA patients through a comprehensive analysis of paired bone marrow and peripheral blood samples with spectral flow cytometry in comparison to healthy age-matched bone marrow donors. Results: We observed a reduced absolute number of NK-cells in peripheral blood of AA patients with a skewed distribution towards CD56bright NK-cells in a subgroup of patients. The enriched CD56bright NK-cells had a lower expression of CD45RA and TIGIT and a higher expression of CD16, compared to healthy donors. Functional analysis revealed no differences in degranulation. However, IFN-g production and perforin expression of NK-cells were reduced in the CD56bright-enriched patient group. The diminished NK-cell function in this subgroup might underly the auto-immunity. Importantly, NK-function of AA patients with reduced CD56bright NK-cells was comparable to healthy donors. Also, B-cell counts were lower in AA patients. Subset analysis revealed a trend towards reduction of transitional B-cells in both absolute and relative numbers compared to healthy controls. As these cells were previously hypothesized as regulatory cells in AA, decreased numbers might be involved in defective inhibition of auto-reactive T-cells. Interestingly, even in patients with normal distribution of precursor B-cells, the transitional compartment was reduced, indicating partial differentiation failure from immature to transitional B-cells or a selective loss. Discussion: Our findings provide a base for future studies to unravel the role of transitional B-cells and CD56bright NK-cells in larger cohorts of pediatric AA patients as diagnostic markers for immune AA and targets for therapeutic interventions. [ABSTRACT FROM AUTHOR]

The early diagnosis of liver cancer is crucial for the treatment and depends on the coordinated use of several test procedures. Early diagnosis is crucial for precision therapy in the treatment of the hepatocellular carcinoma (HCC). Therefore, in this study, the NK cell-related gene prediction model was used to provide the basis for precision therapy at the gene level and a novel basis for the treatment of patients with liver cancer. Natural killer (NK) cells have innate abilities to recognize and destroy tumor cells and thus play a crucial function as the "innate counterpart" of cytotoxic T cells. The natural killer (NK) cells is well recognized as a prospective approach for tumor immunotherapy in treating patients with HCC. In this research, we used publicly available databases to collect bioinformatics data of scRNA-seq and RNA-seq from HCC patients. To determine the NK cell-related genes (NKRGs)-based risk profile for HCC, we isolated T and natural killer (NK) cells and subjected them to analysis. Uniform Manifold Approximation and Projection plots were created to show the degree of expression of each marker gene and the distribution of distinct clusters. The connection between the immunotherapy response and the NKRGs-based signature was further analyzed, and the NKRGs-based signature was established. Eventually, a nomogram was developed using the model and clinical features to precisely predict the likelihood of survival. The prognosis of HCC can be accurately predicted using the NKRGs-based prognostic signature, and thorough characterization of the NKRGs signature of HCC may help to interpret the response of HCC to immunotherapy and propose a novel tumor treatment perspective. [ABSTRACT FROM AUTHOR]

Sanfilippo syndrome results from inherited mutations in genes encoding lysosomal enzymes that catabolise heparan sulfate (HS), leading to early childhood‐onset neurodegeneration. This study explores the therapeutic potential of photobiomodulation (PBM), which is neuroprotective and anti‐inflammatory in several neurodegenerative diseases; it is also safe and PBM devices are readily available. We investigated the effects of 10–14 days transcranial PBM at 670 nm (2 or 4 J/cm2/day) or 904 nm (4 J/cm2/day) in young (3 weeks) and older (15 weeks) Sanfilippo or mucopolysaccharidosis type IIIA (MPS IIIA) mice. Although we found no PBM‐induced changes in HS accumulation, astrocyte activation, CD206 (an anti‐inflammatory marker) and BDNF expression in the brains of Sanfilippo mice, there was a near‐normalisation of microglial activation in older MPS IIIA mice by 904 nm PBM, with decreased IBA1 expression and a return of their morphology towards a resting state. Immune cell immunophenotyping of peripheral blood with mass cytometry revealed increased pro‐inflammatory signalling through pSTAT1 and p‐p38 in NK and T cells in young but not older MPS IIIA mice (5 weeks of age), and expansion of NK, B and CD8+ T cells in older affected mice (17 weeks of age), highlighting the importance of innate and adaptive lymphocytes in Sanfilippo syndrome. Notably, 670 and 904 nm PBM both reversed the Sanfilippo‐induced increase in pSTAT1 and p‐p38 expression in multiple leukocyte populations in young mice, while 904 nm reversed the increase in NK cells in older mice. In conclusion, this is the first study to demonstrate the beneficial effects of PBM in Sanfilippo mice. The distinct reduction in microglial activation and NK cell pro‐inflammatory signalling and number suggests PBM may alleviate neuroinflammation and lymphocyte activation, encouraging further investigation of PBM as a standalone, or complementary therapy in Sanfilippo syndrome. [ABSTRACT FROM AUTHOR]

Natural killer (NK) cells are one of the key members of innate immunity that predominantly reside in the liver, potentiating immune responses against viral infections or malignant tumors. It has been reported that changes in cell numbers and function of NK cells are associated with the development and progression of chronic liver diseases (CLDs) including non‐alcoholic fatty liver disease, alcoholic liver disease, and chronic viral hepatitis. Also, it is known that the crosstalk between NK cells and hepatic stellate cells plays an important role in liver fibrosis and cirrhosis. In particular, the impaired functions of NK cells observed in CLDs consequently contribute to occurrence and progression of hepatocellular carcinoma (HCC). Chronic infections by hepatitis B or C viruses counteract the anti‐tumor immunity of the host by producing the sheddases. Soluble major histocompatibility complex class I polypeptide‐related sequence A (sMICA), released from the cell surfaces by sheddases, disrupts the interaction and affects the function of NK cells. Recently, the MICA/B‐NK stimulatory receptor NK group 2 member D (NKG2D) axis has been extensively studied in HCC. HCC patients with low membrane‐bound MICA or high sMICA concentration have been associated with poor prognosis. Therefore, reversing the sMICA‐mediated downregulation of NKG2D has been proposed as an attractive strategy to enhance both innate and adaptive immune responses against HCC. This review aims to summarize recent studies on NK cell immune signatures and its roles in CLD and hepatocellular carcinogenesis and discusses the therapeutic approaches of MICA/B‐NKG2D‐based or NK cell‐based immunotherapy for HCC. [ABSTRACT FROM AUTHOR]

Immunotherapy combined with chemicals and genetic engineering tools is emerging as a promising strategy to treat triple-negative breast cancer (TNBC), which is more aggressive with poorer progress than other breast cancer subtypes. In this study, lipid-based nanoparticles (LNPs) possessed an NK cell-like function that could deliver tumor-specific therapeutics and inhibit tumor growth. LNPs fused with an NK cell membrane protein system (NK-LNP) have three main features: (i) hydrophilic plasmid DNA can inhibit TNBC metastasis when encapsulated within LNPs and delivered to cells; (ii) the lipid composition of LNPs, including C18 ceramide, exhibits anticancer effects; (iii) NK cell membrane proteins are immobilized on the LNP surface, enabling targeted delivery to TNBC cells. These particles facilitate the targeted delivery of HIC1 plasmid DNA and the modulation of immune cell functions. Delivered therapeutic genes can inhibit metastasis of TNBC and then induce apoptotic cell death while targeting macrophages to promote cytokine release. The anticancer effect is expected to be applied in treating various difficult-to-treat cancers with LNP fused with NK cell plasma membrane proteins, which can simultaneously deliver therapeutic chemicals and genes. [ABSTRACT FROM AUTHOR]

MIL77-3 is one component of antibody cocktail that is produced in our lab and represents an effective regimen for animals suffering from Zaire Ebolavirus (EBOV) infection. MIL77-3 is engineered to increase its affinity for the FcγRIIIa (CD16a) by deleting the fucose in the framework region. The potential effects of this modification on host immune responses, however, remain largely unknown. Herein, we demonstrated that MIL77-3 recognized secreted glycoproptein (sGP), produced by EBOV, and formed the immunocomplex to potently augment antibody-dependent cytotoxicity of human peripheral blood-derived natural killer cells (pNKs), including CD56dim and CD56bright subpopulations, in contrast to the counterparts (Mab114, rEBOV548, fucosylated MIL77-3). Intriguingly, this effect was not observed when NK92-CD16a cell line was utilized and restored by the addition of beads-coupled or membrane-anchored sGP in combination with MIL77-3. Furthermore, sGP bound to unrecognized receptors on T cells contaminated in pNKs rather than NK92-CD16a cells. Administration of beads-coupled sGP/MIL77-3 complex in mice elicited NK activation. Overall, this work reveals an immune-stimulating function of sGP/MIL77-3 complex by triggering cytotoxic activity of NK cells, highlighting the necessity to evaluate the potential impact of MIL77-3 on host immune reaction in clinical trials. IMPORTANCE Zaire Ebolavirus (EBOV) is highly lethal and causes sporadic outbreaks. The passive administration of monoclonal antibodies (mAbs) represents a promising treatment regimen against EBOV. Mounting evidence has shown that the efficacy of a subset of therapeutic mAbs in vivo is intimately associated with its capacity to trigger NK activity, supporting glycomodification of Fc region of anti-EBOV mAbs as a putative strategy to enhance Fc-mediated immune effector function as well as protection in vivo. Our work here uncovers the potential harmful influence of this modification on host immune responses, especially for mAbs with cross-reactivity to secreted glycoproptein (sGP) (e.g., MIL77-3), and highlights it is necessary to evaluate the NK-stimulating activity of a fucosylated mAb engaged with sGP when a new candidate is developed. [ABSTRACT FROM AUTHOR]

The role of immune system components in the development of myocardial remodeling in chronic kidney disease (CKD) and kidney transplantation remains an open question. Our aim was to investigate the associations between immune cell subpopulations in the circulation of CKD patients and kidney transplant recipients (KTRs) with subclinical indices of myocardial performance. We enrolled 44 CKD patients and 38 KTRs without established cardiovascular disease. A selected panel of immune cells was measured by flow cytometry. Classical and novel strain-related indices of ventricular function were measured by speckle-tracking echocardiography at baseline and following dipyridamole infusion. In CKD patients, the left ventricular (LV) relative wall thickness correlated with the CD14++CD16− monocytes (β = 0.447, p = 0.004), while the CD14++CD16+ monocytes were independent correlates of the global radial strain (β = 0.351, p = 0.04). In KTRs, dipyridamole induced changes in global longitudinal strain correlated with CD14++CD16+ monocytes (β = 0.423, p = 0.009) and CD4+ T-cells (β = 0.403, p = 0.01). LV twist and untwist were independently correlated with the CD8+ T-cells (β = 0.405, p = 0.02 and β = −0.367, p = 0.03, respectively) in CKD patients, whereas the CD14++CD16+ monocytes were independent correlates of LV twist and untwist in KTRs (β = 0.405, p = 0.02 and β = −0.367, p = 0.03, respectively). Immune cell subsets independently correlate with left ventricular strain and torsion-related indices in CKD patients and KTRs without established CVD. [ABSTRACT FROM AUTHOR]

TIGIT is an alternative checkpoint receptor (CR) whose inhibition promotes Graft-versus-Leukemia effects of NK cells. Given the significant immune-permissiveness of NK cells circulating in acute myeloid leukemia (AML) patients, we asked whether adoptive transfer of activated NK cells would benefit from additional TIGIT-blockade. Hence, we characterized cytokine-induced memory-like (CIML)-NK cells and NK cell lines for the expression of inhibitory CRs. In addition, we analyzed the transcription of CR ligands in AML patients (CCLE and Beat AML 2.0 cohort) in silico and evaluated the efficacy of CR blockade using in vitro cytotoxicity assays, CD69, CD107a and IFN-γ expression. Alternative but not classical CRs were abundantly expressed on healthy donor NK cells and even further upregulated on CIML-NK cells. In line with our finding that CD155, one important TIGIT-ligand, is reliably expressed on AMLs, we show improved killing of CD155+-AML blasts by NK-92 but interestingly not CIML-NK cells in the presence of TIGIT-blockade. Additionally, our in silico data (n = 671) show that poor prognosis AML patients rather displayed a CD86low CD112/CD155high phenotype, whereas patients with a better outcome rather exhibited a CD86high CD112/CD155low phenotype. Collectively, our data evidence that the complex CR ligand expression profile on AML blasts may be one explanation for the intrinsic NK cell exhaustion observed in AML patients which might be overcome with adoptive NK-92 transfer in combination with TIGIT-blockade. [ABSTRACT FROM AUTHOR]

Background: Granzymes are essential serine proteases in cytotoxic T cells and natural killer (NK) cells, with GZMK's expression being less understood. This study aims to uncover GZMK expression profiles across various immune cell types using single-cell RNA sequencing meta-analysis. Objective: This study aims to uncover GZMK expression profiles across various immune cell types using single-cell RNA sequencing meta-analysis. Methods: We conducted a meta-analysis using cellxgene, an interactive data exploration platform developed by the Chan Zuckerberg Initiative. We focused on mature T cells, NK cells, B cells, and NKT cells. We also checked transcription factor binding sites at the granzyme gene promoter regions using JASPAR. Comparative analysis was also done using mouse single-cell RNA sequencing data. Results: GZMK was the most lowly expressed in NK cells and mature NKT cells in most tissues except for colon and lymph nodes. In mature T cells, GZMK is similarly or more highly expressed than other granzymes. HBCA data revealed weak expression of GZMK in NK cells but strong expression in effector memory CD8-positive, alpha–beta T cells. Combined data shows no significant difference in GZMK expression between cell types. Subtype analysis shows that GZMK expression was higher in CD16-negative, CD56-bright NK cells when compared to CD16-positive, CD56-dim NK cells. We also identified unique transcription factor binding sites for GZMK. While this pattern in mouse data with low Gzmk expression in NK cells and higher T cells was repeated. Conclusion: GZMK expression is distinctively regulated among immune cells and tissues, with unique promoter regions and transcription factor binding sites contributing to this differential expression. These insights into GZMK's role in immune function and regulation offer potential therapeutic targets. [ABSTRACT FROM AUTHOR]

Oral squamous cell carcinoma (OSCC) constitutes over 90% of oral cancers, known for its aggressiveness and poor prognosis. Photodynamic therapy (PDT) has emerged as a promising adjuvant therapy and is linked to immunogenic cell death, activating innate and adaptive anti‐tumor responses. Natural Killer (NK) cells, key players in malignant cell elimination, have not been extensively studied in PDT. This study evaluates whether PDT increases OSCC cell lines' susceptibility to NK cell cytotoxicity. PDT, using 5‐aminolevulinic acid (5‐ALA) and LED irradiation, was applied to Ca1 and Luc4 cell lines. Results showed a dose‐dependent viability decrease post‐PDT. Gene expression analysis revealed upregulation of NK cell‐activating ligands (ULBP1‐4, MICA/B) and decreased MHC class I expression in Ca1, suggesting increased NK cell susceptibility. Enhanced NK cell cytotoxicity was confirmed in Ca1 but not in Luc4 cells. These findings indicate that PDT may enhance NK cell‐mediated cytotoxicity in OSCC, offering potential for improved treatment strategies. [ABSTRACT FROM AUTHOR]

Natural killer (NK) cells play a crucial role in both innate immunity and the activation of adaptive immunity. The activating effect of Mn2+ on cyclic GMP‐AMP(cGAS)–stimulator of interferon genes (STING signaling has been well known, but its effect on NK cells remains elusive. In this study, we identified the vital role of manganese (Mn2+) in NK cell activation. Mn2+ directly boosts cytotoxicity of NK cells and promotes the cytokine secretion by NK cells, thereby activating CD8+ T cells and enhancing their antitumor activity. Furthermore, Mn2+ can simultaneously activate NK‐cell intrinsic cGAS and STING and consequently augment the expression of ubiquitously transcribed tetratricopeptide repeat on chromosome X (UTX to promote the responsiveness of NK cells. Our results contribute to a broader comprehension of how cGAS–STING regulates NK cells. As a potent agonist of cGAS–STING, Mn2+ provides a promising option for NK cell‐based immunotherapy of cancers. [ABSTRACT FROM AUTHOR]

Despite enormous efforts being invested in the development of novel therapies for brain malignancies, there remains a dire need for effective treatments, particularly for pediatric glioblastomas. Their poor prognosis has been attributed to the fact that conventional therapies target tumoral cells, but not glioblastoma stem cells (GSCs). GSCs are characterized by self-renewal, tumorigenicity, poor differentiation, and resistance to therapy. These characteristics represent the fundamental tools needed to recapitulate the tumor and result in a relapse. The mechanisms by which GSCs alter metabolic cues and escape elimination by immune cells are discussed in this article, along with potential strategies to harness effector immune cells against GSCs. As cellular immunotherapy is making significant advances in a variety of cancers, leveraging this underexplored reservoir may result in significant improvements in the treatment options for brain malignancies. [ABSTRACT FROM AUTHOR]

Oral squamous cell carcinoma (OSCC), a major subtype of head and neck cancers, presents significant challenges due to its aggressive feature and limited therapeutic efficacy of conventional treatments. In response to these challenges, Natural Killer (NK) cells, a vital component of the innate immune system, are being explored for their therapeutic potential in OSCC due to their inherent ability to target and eliminate cancer cells without prior sensitization. This review uniquely focuses on the evolving role of NK cells specifically in OSCC, incorporating recent advancements in CAR-NK cell engineering and personalized therapy approaches that have not been comprehensively covered in previous reviews. The mechanisms through which NK cells exert cytotoxic effects on tumor cells include direct killing through the engagement of natural cytotoxic receptors and antibody-dependent cellular cytotoxicity (ADCC), making them promising agents in cancer immunotherapy. Additionally, the article explores recent advancements in engineering NK cells to enhance their antitumor activity, such as the modification with chimeric antigen receptors (CARs) to target specific tumor antigens. Clinical implications of NK cell-based therapies, including the challenges of integrating these treatments with existing protocols and the potential for personalized therapy, are examined. The review highlights the promise of NK cell therapies in improving outcomes for OSCC patients and outlines future directions for research in this dynamic field of oncological immunotherapy. [ABSTRACT FROM AUTHOR]

The adaptive response occurs only after 7–10 days of antigen presentation. Nevertheless, the autoreactive T cells infiltrate the stroke lesion within the first 48 h. Thus, we hypothesized that the unconventional lymphocytes as invariant natural killer T cells (iNKT) and γδT cells that share immediate innate and delayed adaptive response features are involved in acute stroke pathophysiology. We assessed prospectively the quantity of circulating iNKT cells, γδT cells, and NK cells with flow cytometry in 52 subjects within three months after stroke, and we compared the results with those obtained in age-, sex-, and vascular risk factor-matched controls. We studied lymphocyte parameters regarding clinical outcomes, infarct volume, stroke-associated infection (SAI), and burden risk factors. The reduced number of circulating γδT cells and decreased percentage of the Vδ2 subset in the acute phase of stroke correlated with worse neurological status in the recovery phase. In subjects treated with thrombolysis and those who developed SAI, a lower percentage of γδT cells in the 90-day follow-up was observed. An increased percentage of iNKT cells in the acute and subacute phases of stroke was observed, and it was related to the worse clinical status. The circulating NK cells do not change temporarily or affect the outcomes after stroke. It seems that γδT cells play a long-lasting role in ischemic stroke, mainly related to the Vδ2 subset. The role of iNKT cells appears to be detrimental, especially in the acute and subacute phases of stroke. The effect of circulating NK cells on the outcome after stroke seems negligible. [ABSTRACT FROM AUTHOR]

Background and aims: Hepatitis B virus (HBV)-associated liver cirrhosis (LC), a common condition with high incidence and mortality rates, is often associated with diabetes mellitus (DM). However, the molecular mechanisms underlying impaired glucose regulation during HBV-associated LC remain unclear. Methods: Data from 63 patients with LC and 62 patients with LC-associated DM were analysed. Co-culture of NK cells and islet β cell lines were used to study the glucose regulation mechanism. A mouse model of LC was used to verify the effect of S100A8/A9 on the glucose regulation. Results: Higher levels of interferon (IFN)-γ derived from natural killer (NK) cells and lower levels of insulin emerged in the peripheral blood of patients with both LC and DM compared with those from patients with LC only. IFN-γ derived from NK cells facilitated β cell necroptosis and impaired insulin production. Furthermore, S100A8/A9 elevation in patients with both LC and DM was found to upregulate IFN-γ production in NK cells. Consistently, in the mouse model for LC, mice treated with carbon tetrachloride (CCL4) and S100A8/A9 exhibited increased blood glucose, impaired insulin production, increased IFN-γ, and increased β cells necroptosis compared with those treated with CCL4. Mechanistically, S100A8/A9 activated the p38 MAPK pathway to increase IFN-γ production in NK cells. These effects were diminished after blocking RAGE. Conclusion: Together, the data indicate that IFN-γ produced by NK cells induces β cell necroptosis via the S100A8/A9–RAGE–p38 MAPK axis in patients with LC and DM. Reduced levels of S100A8/A9, NK cells, and IFN-γ could be valuable for the treatment of LC with DM. Accumulation of S100A8/A9 in patients with LC may indicate the emergence of DM. [ABSTRACT FROM AUTHOR]

Natural killer (NK) cell therapy, a developing approach in cancer immunotherapy, involves isolating NK cells from peripheral blood. However, due to their limited number and activity, it is essential to significantly expand these primary NK cells and enhance their cytotoxicity. In this study, we investigated how Raddeanin A potentiate NK activity using KHYG‐1 cells. The results indicated that Raddeanin A increased the expression levels of cytolytic molecules such as perforin, granzymes A and granzymes B, granulysin and FasL in KHYG‐1 cells. Raddeanin A treatment increased CREB phosphorylation, p65 phosphorylation, NFAT1 and acetyl‐histone H3 expression. Raddeanin A elevated caspase 3 and PARP cleavage, increased t‐Bid expression, promoting apoptosis in K562 cells. Furthermore, it reduced the expression of HMGB2, SET and Ape1, impairing the DNA repair process and causing K562 cells to die caspase‐independently. Additionally, Raddeanin A increased ERK, p38 and JNK phosphorylation at the molecular level, which increased granzyme B production in KHYG‐1 cells. Raddeanin A treatment increased Ras, Raf phosphorylation, MEK phosphorylation, NKG2D, NKp44 and NKp30 expression in KHYG‐1 cells. Collectively, our data indicate that Raddeanin A enhances the cytotoxic activity of NK cells against different cancer cells. [ABSTRACT FROM AUTHOR]

Lung cancer is the leading cause of tumor-induced death worldwide and remains a primary global health concern. In homeostasis, due to its unique structure and physiological function, the lung microenvironment is in a state of immune tolerance and suppression, which is beneficial to tumor development and metastasis. The lung tumor microenvironment is a more complex system that further enhances the immunosuppressive features in the lungs. NK cells are abundantly located in the lungs and play crucial roles in lung tumor surveillance and antitumor immunity. However, the immunosuppressive microenvironment promotes significant challenges to NK cell features, leading to their hypofunction, exhaustion, and compromised antitumor activity. Thus, understanding the complex interactions among the lung microenvironment, lung tumor microenvironment, and NK cell exhaustion is critical for the development of effective cancer immunotherapeutic strategies. The present review will discuss NK cell hypofunction and exhaustion within the lung microenvironment and lung tumor microenvironment, focusing on lung tissue-specific factors, including key cytokines and unique environmental components, that modulate NK cell activation and function. Understanding the functional mechanisms of key factors would help to design strategies to reverse NK cell exhaustion and restore their antitumor function within the lung tumor microenvironment. [ABSTRACT FROM AUTHOR]

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

Hypoxia-inducible factor （HIF） are a family of molecules that are critical for regulating cellular adaptation to hypoxia, which can be activated by hypoxia and other stimuli, and then translocated into nucleus, where they modulate the transcription of target genes. Under the pathological conditions, such as inflammation and tumor, tissue microenvironment is often hypoxic. Innate lymphoid cells （ILCs） and T lymphocytes serve as important effector cells in defense against infection and tumor, and their functions are regulated by HIF proteins. In recent years, increasing evidence highlights the importance of HIF1α and HIF2α, two members of the HIF family, in regulating ILCs and T cells, providing new insights into mechanisms and treatment of diseases. This review summarizes the research progress on the role of HIF family proteins in ILCs and T cells and the underlying mechanisms. [ABSTRACT FROM AUTHOR]

Natural killer (NK) cells can be effective immunotherapeutic anti-cancer agents due to their ability to selectively target and kill tumor cells. This activity is modulated by the interaction of NK cell receptors with inhibitory ligands on the surface of target cells. NK cell inhibitory ligands can be upregulated on tumor cell surfaces in response to interferon-gamma (IFN-γ), a cytokine which is produced by activated NK cells. We hypothesized that the resistance of tumor cells to NK cell killing could be overcome by expression of the parainfluenza virus 5 (PIV5) V protein, which has known roles in blocking IFN-γ signaling. This was tested with human PM21-NK cells produced through a previously developed particle-based method which yields superior NK cells for immunotherapeutic applications. Infection of human SK-N-SH neuroblastoma cells with PIV5 blocked IFN-γ-mediated upregulation of three NK cell inhibitory ligands and enhanced in vitro killing of these tumor cells by PM21-NK cells. SK-N-SH cells transduced to constitutively express the V protein alone were resistant to IFN-γ-mediated increases in cell surface expression of NK cell inhibitory ligands. Real-time in vitro cell viability assays demonstrated that V protein expression in SK-N-SH cells was sufficient to increase PM21-NK cell-mediated killing. Toward a potential therapeutic application, transient lentiviral delivery of the V gene also enhanced PM21-NK cell killing in vitro. Our results provide the foundation for novel therapeutic applications of V protein expression in combination with ex vivo NK cell therapy to effectively increase the killing of tumor cells. [ABSTRACT FROM AUTHOR]

This study aimed to encapsulate natural killer (NK) cells in a hydrogel to sustain their function within the hypoxic tumour microenvironments. An alginate-gelatine hydrogel was generated via electrospray technology. Hydrogel biocompatibility was assessed through cell counting kit-8 and Live/Dead assays to ascertain cell. Moreover, we analysed lactate dehydrogenase assays to evaluate the cytotoxicity against tumours and utilised RT-qPCR to analyse cytokine gene level. Alginate and gelatine formed hydrogels with diameters ranging from 489.2 ± 23.0 μm, and the encapsulation efficiency was 34.07 ± 1.76%. Encapsulated NK cells exhibited robust proliferation and tumour-killing capabilities under normoxia and hypoxia. Furthermore, encapsulation provided a protective shield against cell viability under hypoxia. Importantly, tumour-killing cytotoxicity through cytokines upregulation such as granzyme B and interferon-gamma was preserved under hypoxia. The encapsulation of NK cells not only safeguards their viability but also reinforces anticancer capacity, countering the inhibition of activation induced by hypoxia. [ABSTRACT FROM AUTHOR]

Objectives: Increasing evidence suggests that Fc‐mediated antibody effector functions have an important role in protection against respiratory viruses, including SARS‐CoV‐2. However, limited data are available on the potential differences in the development, heterogeneity and durability of these responses in children compared to adults. Methods: Here, we assessed the development of spike S1‐specific serum antibody‐dependent cellular phagocytosis (ADCP), complement deposition (ADCD) and natural killer cell activation (ADNKA), alongside specific antibody binding concentrations (IgG, IgA and IgM) and IgG avidity in healthy adults (n = 38, 18–56 years) and children (n = 21, 5–16 years) following primary SARS‐CoV‐2 infection, with a 10‐month longitudinal follow‐up. Differences between groups were assessed using a nonparametric Kruskal–Wallis test with Dunn's multiple comparisons test. Results: We found similar (functional) antibody responses in children compared to adults, with a tendency for increased durability in children, which was statistically significant for ADCD (P < 0.05). While ADNKA was strongly reduced in both adults (P < 0.001) and children (P < 0.05) at the latest time point, ADCP remained relatively stable over time, possibly relating to an increase in avidity of the spike‐specific antibodies (P < 0.001). Finally, the ADNKA capacity relative to antibody concentration appeared to decrease over time in both children and adults. Conclusion: In conclusion, our data provide novel insights into the development of SARS‐CoV‐2‐specific antibody Fc‐mediated effector functions in children and adults. An increased understanding of these characteristics in specific age populations is valuable for the future design of novel and improved vaccination strategies for respiratory viruses such as SARS‐CoV‐2. [ABSTRACT FROM AUTHOR]

Background: The role of neutrophils in hepatitis B virus (HBV) infection has been a subject of debate due to their involvement in antiviral responses and immune regulation. This study aimed to elucidate the neutrophil characteristics in patients with chronic hepatitis B (CHB). Methods: Through flow cytometry and ribonucleic acid-sequencing analysis, the phenotypes and counts of neutrophils were analyzed in patients with CHB. Moreover, the effects of HBeAg on neutrophils and the corresponding pattern recognition receptors were identified. Simultaneously, the cross-talk between neutrophils and natural killer (NK) cells was investigated. Results: Neutrophils were activated in patients with CHB, characterized by higher expression levels of programmed death-ligand 1 (PD-L1), cluster of differentiation 86, and interleukin-8, and lower levels of CXC motif chemokine receptor (CXCR) 1 and CXCR2. Hepatitis B e antigen (HBeAg) partially induces neutrophil activation through the Toll-like receptor 2 (TLR2). A consistent upregulation of the TLR2 and HBeAg expression was observed in patients with CHB. Notably, the genes encoding molecules pivotal for NK-cell function upon NK receptor engagement enriched in neutrophils after HBeAg activation. The HBeAg-activated neutrophils demonstrated the ability to decrease the production of interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) in NK cells, while the PD-1 and PD-L1 pathways partially mediated the immunosuppression. Conclusions: The immunosuppression of neutrophils induced by HBeAg suggests a novel pathogenic mechanism contributing to immune tolerance in patients with CHB. [ABSTRACT FROM AUTHOR]

The infusion autograft absolute number of inhibitory killer immunoglobulin-like receptor (KIR) 2DL2 and activating natural killer (NK)p30 cells are predictors of clinical outcomes in lymphoma patients undergoing autologous peripheral blood hematopoietic stem cell transplantation (APBHSCT). To assess if the long-term recovery of these NK cell subsets still holds clinical relevance, we set up to investigate their prognostic ability at day 100 post-APBHSCT. This was a retrospective single-institution study including 107 patients from our prior phase III trial who had a clinical assessment at day 100 post-APBHSCT. The median follow-up from day 100 was 168.19 months (interquartile range: 156.85–181.28 months). Patients with day 100 inhibitory KIR2DL2 < 0.08 cells/µL and activating NKp30 ≥ 0.19 cells/µL experienced superior overall survival (OS) and progression-free survival (PFS). A multivariate analysis revealed both the day 100 inhibitory KIR2DL2 [OS: HR = 1.449, 95%CI, 1.231–1.895, p < 0.013; and PFS: HR = 2.069, 95%CI, 1.134–3.775, p < 0.021] and activating NKp30 [OS: HR = 4.985, 95%CI, 2.614–9.506, p < 0.0001; and PFS: HR = 4.661, 95%CI, 2.598–8.393, p < 0.0001] were independent predictors for OS and PFS. Inhibitory KIR2DL2 and activating NKp30 NK cells at day 100 are prognostic immune biomarkers in lymphoma patients treated with APBHSCT. [ABSTRACT FROM AUTHOR]

Breast cancer (BC) is the most commonly diagnosed cancer in women globally. Natural killer (NK) cells play a vital role in tumour immunosurveillance. This study aimed to establish a prognostic model using NK cell‐related genes (NKRGs) by integrating single‐cell transcriptomic data with machine learning. We identified 44 significantly expressed NKRGs involved in cytokine and T cell‐related functions. Using 101 machine learning algorithms, the Lasso + RSF model showed the highest predictive accuracy with nine key NKRGs. We explored cell‐to‐cell communication using CellChat, assessed immune‐related pathways and tumour microenvironment with gene set variation analysis and ssGSEA, and observed immune components by HE staining. Additionally, drug activity predictions identified potential therapies, and gene expression validation through immunohistochemistry and RNA‐seq confirmed the clinical applicability of NKRGs. The nomogram showed high concordance between predicted and actual survival, linking higher tumour purity and risk scores to a reduced immune score. This NKRG‐based model offers a novel approach for risk assessment and personalized treatment in BC, enhancing the potential of precision medicine. [ABSTRACT FROM AUTHOR]

Sumei Chen,1,&ast; Lingrong Yang,2,&ast; Bing Xia,3 Haitao Zhu,4 Zhenghao Piao,5 Youssef Jounaidi6 1Department of Radiation Oncology, Hangzhou Cancer Hospital, Hangzhou, Zhejiang, 310002, People’s Republic of China; 2Department of Hangzhou Cancer Institution, Hangzhou Cancer Hospital, Hangzhou, Zhejiang, 310002, People’s Republic of China; 3Department of Thoracic Oncology, Hangzhou Cancer Hospital, Hangzhou, Zhejiang, 310002, People’s Republic of China; 4Department of Hepatobiliary Surgery, The Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, 550001, People’s Republic of China; 5Department of Basic Medical Science, Hangzhou Normal University, Hangzhou, Zhejiang, 311121, People’s Republic of China; 6Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02114, USA&ast;These authors contributed equally to this workCorrespondence: Youssef Jounaidi, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA, 02114, USA, Email yjounaidi@mgh.harvard.eduBackground: Enhancing NK cells’ antitumor activity requires sustained cytokine signaling. Interleukin-15 (IL-15) is a potent immunostimulatory cytokine used to armor CAR-NK and CAR-T cell immunotherapies. However, strategies to increase IL-15 expression and antitumor effect may trigger systemic toxicity with the potential to promote oncogenesis and autoimmune diseases.Methods: To overcome these limitations, we developed a new platform (IL15RB) whereby IL-15 with IL-2 signal peptide is tethered to its receptor, IL2Rβ.Results: NK92-expressing IL15RB (NK92IL15RB) cells expand indefinitely without exogenous cytokines and have significantly higher anticancer activity than NK-92 stimulated by IL-15, IL-2, or expressing tethered IL-2. NK92IL5RB showed resistance to irradiation and IL-4. However, TGFβ 1 substantially reduced NK92IL5RB killing, suggesting the need to inhibit TGFβ 1 in IL-15-mediated immunotherapies. IL15RB induced strong STAT3 but weaker STAT5 and STAT1 activation compared to IL-2. Chronic exposure of NK92IL15RB cells to cancer cells reduced STAT3 and STAT1 activation irreversibly, suggesting a role in exhaustion. Combination with CAR-CD19 enhanced NK92IL15RB antitumor activity against leukemia and increased its STAT5 activation. NK92IL15RB anti-tumors activity was further enhanced by combination with anti-PD1.Conclusion: Our data suggest that the tethering of IL-15 to its receptor IL2Rβ empowers NK cell cytolytic activity. Additionally, the tethering of IL-15 will prevent any systemic risk of toxicity.Keywords: IL-15, IL2RB receptor, natural killer cells, cancer immunotherapy, IL15RB

Maria Vernet-Tomas,1,2 Ivonne Vazquez,1,3 Francesc Olivares,3 David Lopez,3 Jose Yelamos,2,4 Laura Comerma1– 3 1Breast Diseases Unit, Hospital Del Mar, Barcelona, Spain; 2Cancer Research Program, Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain; 3Department of Pathology; Hospital del Mar, Barcelona, Spain; 4Laboratory of Immunology, Department of Pathology; Hospital Del Mar, Barcelona, SpainCorrespondence: Maria Vernet-Tomas, Breast Diseases Unit, Hospital del Mar, Passeig Marítim de la Barceloneta 25- 29, Barcelona, 08003, Spain, Tel +342483132, Email mvernet@hmar.catPurpose: The aim of this study was to determine whether low HLA-I expression and NK cells infiltration are related to prognostic features in breast cancer, as observed in cancers in other locations and non-hormone dependent breast cancers. Particularly, we explored their relation to infiltrated axillary lymph nodes (ALNs), with the aim of finding new predictors helping to decide the extent of axillary surgery.Patients and Methods: We conducted a retrospective correlational analysis of 35 breast cancers from 35 breast cancer patients showing axillary infiltration at diagnosis and with upfront surgery. HLA-I H-score and the number of NK cells x 50 high power fields (HPF) in the biopsy specimen were correlated with pathological variables of the surgical specimen: number of infiltrated ALNs, tumor size, histological type, the presence of ductal carcinoma in situ, focality, histological grade, necrosis, lymphovascular and perineural invasion, Her2Neu status, and the percentages of tumor-infiltrating lymphocytes (TILs), estrogen receptor, progesterone receptor, ki67, and p53.Results: All tumors showed hormone receptor expression and three of them Her2Neu positivity. A positive correlation (p=0.001&ast;&ast;) was found between HLA-I H-score and TILs and Ki67 expression. HLA H-score increased with histological grade and was higher in unifocal than in multifocal disease (p=0.044 and p=0.011, respectively). No other correlations were found.Conclusion: High HLA-I H-score values correlated with features of poor prognosis in this cohort of luminal breast tumors, but not with infiltrated ALNs. This finding highlights the differences between luminal breast cancer, and cancers in other locations and non-hormone dependent breast cancers, in which low HLA-I expression tends to be associated with poor prognostic features.Keywords: luminal breast cancer, HLA-I, natural killer cells, prognostic features, axillary lymph nodes

Abstract Background Chronic lymphoproliferative disorder of natural killer cells (CLPD-NK) is a rare disease characterized by a persistent increase in NK cells in peripheral blood and is generally asymptomatic. If present, symptoms may include fatigue, B symptoms (fever, night sweats, and unintentional weight loss), autoimmune-associated diseases, splenomegaly, and infection due to neutropenia. Peripheral neuropathy, however, is uncommon with an incidence of 3%. Neurolymphomatosis is a neurological manifestation of non-Hodgkin lymphoma and leukemia in which neurotropic neoplastic cells infiltrate the nerves. Moreover, neurolymphomatosis caused by CLPD-NK is extremely rare, with even fewer cases of autonomic dysfunction. We report a case of neurolymphomatosis associated with CLPD-NK and developed autonomic dysfunction, including orthostatic hypotension and gastrointestinal symptoms. Case presentation The patient was a 61-year-old male who was referred to our hospital for leukocytosis. He was diagnosed with CLPD-NK; however, was untreated since he had no hepatosplenomegaly, and other systemic symptoms. He later developed numbness in his lower extremities. Cerebral spinal fluid examination revealed a markedly elevated protein level of 140 mg/dL, and contrast-enhanced magnetic resonance imaging showed bilateral L4 and 5 nerve roots with enlargement and contrast effect. An immune-mediated polyradiculoneuropathy was suspected, and he was treated with intravenous methylprednisolone and immunoglobulin followed by oral prednisolone and cyclosporine. Although his symptoms were relieved by the immunotherapy, significant autonomic dysfunction, including intractable diarrhea, decreased sweating, and orthostatic hypotension, appeared. Additionally, tests for onconeuronal antibodies, ganglionic nicotinic acetylcholine receptor (gAChR) antibody, NF155, CNTN1, Caspr1 antibody, and anti-ganglioside antibodies were all negative. A sural nerve biopsy revealed lymphocytic infiltration, and immunohistochemical staining of lymphocytes confirmed the infiltration of NK and T cells. Therefore, a diagnosis of neurolymphomatosis caused by CLPD-NK was made, and chemotherapy led to partial symptom improvement. Conclusions We experienced a case of pathologically diagnosed neurolymphomatosis with autonomic dysfunction associated with CLPD-NK. In cases of subacute to chronic autonomic dysfunction, paraneoplastic neuropathy, amyloidosis, and autoimmune autonomic ganglionopathy are considered; however neurolymphomatosis caused by CLPD-NK, an important cause of autonomic dysfunction, is not. In difficult to make diagnosis, aggressive nerve biopsy is required.

Abstract Natural Killer (NK) cells are exciting candidates for cancer immunotherapy with potent innate cytotoxicity and distinct advantages over T cells for Chimeric Antigen Receptor (CAR) therapy. Concerns regarding the safety, cost, and scalability of viral vectors has ignited research into non-viral alternatives for gene delivery. This review comprehensively analyses recent advancements and challenges with non-viral genetic modification of NK cells for allogeneic CAR-NK therapies. Non-viral alternatives including electroporation and multifunctional nanoparticles are interrogated with respect to CAR expression and translational responses. Crucially, the link between NK cell biology and design of drug delivery technologies are made, which is essential for development of future non-viral approaches. This review provides valuable insights into the current state of non-viral CAR-NK cell engineering, aimed at realising the full potential of NK cell-based immunotherapies. Graphical Abstract Non-viral production of “off-the-shelf” CAR-NK cells. 1. NK cells may be purified from donor blood, differentiated from stem cells or produced from immortalised cell lines in the lab. 2. NK-specific CAR design modified from CAR-T designs to include NK transmembrane domains (NKG2D, NKp44), co-stimulatory receptors (e.g., DAP10, 2B4) and NK cell receptors (NKG2D). 3. Non-viral genetic modification of NK cells can include delivery of CAR construct via DNA or mRNA, and knock-in/out of specific genes using gene editing tools (e.g., CRISPR Cas9, transposons). This requires a gene delivery method which may include electroporation, lipid and multifunctional nanoparticles and cell penetrating peptides. The resultant CAR-NK cells are then expanded in vitro and may be delivered as an "off-the-shelf" product to treat multiple patients.

Abstract The early diagnosis of liver cancer is crucial for the treatment and depends on the coordinated use of several test procedures. Early diagnosis is crucial for precision therapy in the treatment of the hepatocellular carcinoma (HCC). Therefore, in this study, the NK cell-related gene prediction model was used to provide the basis for precision therapy at the gene level and a novel basis for the treatment of patients with liver cancer. Natural killer (NK) cells have innate abilities to recognize and destroy tumor cells and thus play a crucial function as the “innate counterpart” of cytotoxic T cells. The natural killer (NK) cells is well recognized as a prospective approach for tumor immunotherapy in treating patients with HCC. In this research, we used publicly available databases to collect bioinformatics data of scRNA-seq and RNA-seq from HCC patients. To determine the NK cell-related genes (NKRGs)-based risk profile for HCC, we isolated T and natural killer (NK) cells and subjected them to analysis. Uniform Manifold Approximation and Projection plots were created to show the degree of expression of each marker gene and the distribution of distinct clusters. The connection between the immunotherapy response and the NKRGs-based signature was further analyzed, and the NKRGs-based signature was established. Eventually, a nomogram was developed using the model and clinical features to precisely predict the likelihood of survival. The prognosis of HCC can be accurately predicted using the NKRGs-based prognostic signature, and thorough characterization of the NKRGs signature of HCC may help to interpret the response of HCC to immunotherapy and propose a novel tumor treatment perspective.

The innate immune system is the body's first line of defense against infection. Natural killer (NK) cells, a vital part of the innate immune system, help to control infection and eliminate cancer. Studies have identified a vast array of receptors that NK cells use to discriminate between healthy and unhealthy cells. However, at present, it is difficult to explain how NK cells will respond to novel stimuli in different environments. In addition, the expression of different receptors on individual NK cells is highly stochastic, but the reason for these variegated expression patterns is unclear. Here, we studied the recognition of unhealthy target cells as an inference problem, where NK cells must distinguish between healthy targets with normal variability in ligand expression and ones that are clear "outliers." Our mathematical model fits well with experimental data, including NK cells' adaptation to changing environments and responses to different target cells. Furthermore, we find that stochastic, "sparse" receptor expression profiles are best able to detect a variety of possible threats, in agreement with experimental studies of the NK cell repertoire. While our study was specifically motivated by NK cells, our model is general and could also apply more broadly to explain principles of target recognition for other immune cell types.

The implementation of cancer immunotherapies has seen limited clinical success in head and neck squamous cell carcinoma (HNSCC). Interleukin-2 (IL-2), which modulates the survival and functionality of lymphocytes, is an attractive target for new immunotherapies but one that is limited by presence of regulatory T cells (Tregs) expressing the high-affinity IL-2Rα. The bispecific immunocytokine PD1-IL2v preferentially delivers IL-2 signaling through IL-2Rβγ on PD-1-expressing cells. Selectively targeting the intermediate-affinity IL-2Rβγ can be leveraged to induce anti-tumor immune responses in effector T cells and natural killer (NK) cells while limiting the negative regulation of IL-2Rα activation on Tregs. Using radiation therapy (RT) in combination with PD1-IL2v improves local tumor control and survival, and controls metastatic spread in orthotopic HNSCC tumor models. PD1-IL2v drives systemic activation and expansion of circulating and tumor-infiltrating cytotoxic T cells and NK cells while limiting Treg-mediated immunosuppression. These data show that PD1-L2v induces durable systemic tumor control in HNSCC.

AbstractContext Rice bran arabinoxylan compound (RBAC) is a natural immunomodulator with anticancer properties.Objective This study critically evaluates the available evidence on the biological pathways of RBAC and its effects on cancer treatment.Methods This secondary analysis of a scoping review includes studies evaluating the mechanisms of RBAC on healthy or malignant cells, animal models, or humans for cancer prevention or treatment. Data from randomized controlled trials on survival and quality of life outcomes were subjectd to meta analysis.Results The evidence synthesis was based on 38 articles. RBAC exhibited antitumor properties by promoting apoptosis and restoring immune function in cancer patients to enhance inflammatory and cytotoxic responses to block tumorigenesis. RBAC works synergistically with chemotherapeutic agents by upregulating drug transport. In a clinical trial, combining RBAC with chemoembolization in treating liver cancer showed improved response, reduced recurrence rates, and prolonged survival. RBAC also augments the endogenous antioxidant system to prevent oxidative stress and protect against radiation side effects. In addition, RBAC has chemoprotective effects. Animals and humans have exhibited reduced toxicity and side effects from chemotherapy. Meta analysis indicates that RBAC treatment increases the survival odds by 4.02-times (95% CI: 1.67, 9.69) in the first year and 2.89-times (95% CI: 1.56, 5.35) in the second year.Conclusion RBAC is a natural product with immense potential in cancer treatment. Additional research is needed to characterize, quantify, and standardize the active ingredients in RBAC responsible for the anticancer effects. More well-designed, large-scale clinical trials are required to substantiate the treatment efficacies further.

Natural killer (NK) cells make only a small fraction of immune cells in the human body, however, play a pivotal role in the fight against cancer by the immune system. They are capable of eliminating abnormal cells via several direct or indirect cytotoxicity pathways in a self-regulating manner, which makes them a favorable choice as a cellular therapy against cancer. Additionally, allogeneic NK cells, unlike other lymphocytes, do not or only minimally cause graft-versus-host diseases opening the door for an off-the-shelf therapy. However, to date, the production of NK cells faces several difficulties, especially because the critical process parameters (CPPs) influencing the critical quality attributes (CQAs) are difficult to identify or correlate. There are numerous different cultivation platforms available, all with own characteristics, benefits and disadvantages that add further difficulty to define CPPs and relate them to CQAs. Our goal in this contribution was to summarize the current knowledge about NK cell expansion CPPs and CQAs, therefore we analyzed the available literature of both dynamic and static culture format experiments in a systematic manner. We present a list of the identified CQAs and CPPs and discuss the role of each CPP in the regulation of the CQAs. Furthermore, we could identify potential relationships between certain CPPs and CQAs. The findings based on this systematic literature research can be the foundation for meaningful experiments leading to better process understanding and eventually control. [ABSTRACT FROM AUTHOR]

Background: Neuroblastoma is the most common extracranial solid tumor in children and accounts for 15% of pediatric cancer related deaths. Targeting neuroblastoma with immunotherapies has proven challenging due to a paucity of immune cells in the tumor microenvironment and the release of immunosuppressive cytokines by neuroblastoma tumor cells. We hypothesized that combining an oncolytic Herpes Simplex Virus (oHSV) with natural killer (NK) cells might overcome these barriers and incite tumor cell death. Methods: We utilized MYCN amplified and non-amplified neuroblastoma cell lines, the IL-12 expressing oHSV, M002, and the human NK cell line, NK-92 MI. We assessed the cytotoxicity of NK cells against neuroblastoma with and without M002 infection, the effects of M002 on NK cell priming, and the impact of M002 and priming on the migratory capacity and CD107a expression of NK cells. To test clinical applicability, we then investigated the effects of M002 and NK cells on neuroblastoma in vivo. Results: NK cells were more attracted to neuroblastoma cells that were infected with M002. There was an increase in neuroblastoma cell death with the combination treatment of M002 and NK cells both in vitro and in vivo. Priming the NK cells enhanced their cytotoxicity, migratory capacity and CD107a expression. Conclusions: To the best of our knowledge, these investigations are the first to demonstrate the effects of an oncolytic virus combined with self-maintaining NK cells in neuroblastoma and the priming effect of neuroblastoma on NK cells. The current studies provide a deeper understanding of the relation between NK cells and neuroblastoma and these data suggest that oHSV increases NK cell cytotoxicity towards neuroblastoma. [ABSTRACT FROM AUTHOR]

Abstract Vitiligo and halo nevus are immune-mediated skin diseases that have a similar pathogenesis and involve cellular cytotoxicity mechanisms that are not yet fully understood. In this study, we investigated the expression patterns of the cytolytic molecule granulysin (GNLY) in different cytotoxic cells in skin samples of vitiligo and halo nevus. Skin biopsies were taken from perilesional and lesional skin of ten vitiligo patients, eight patients with halo nevus and ten healthy controls. We analysed the expression of GNLY by immunohistochemistry in CD8+ and CD56+ NK cells. A significantly higher accumulation of GNLY+, CD8+ GNLY+ and fewer CD56+ GNLY+ cells was found in the lesional skin of vitiligo and halo nevus than in the healthy skin. These cells were localised in the basal epidermis and papillary dermis, suggesting that GNLY may be involved in the immune response against melanocytes. Similarly, but to a lesser extent, upregulation of GNLY+ and CD8+ GNLY+ cells was observed in the perilesional skin of vitiligo and halo nevus compared to healthy controls. In this study, we demonstrated for the first time an increased expression of CD8+ GNLY+ T lymphocytes and CD56+ GNLY+ NK cells in lesions of vitiligo and halo nevus, indicating the role of GNLY in the pathogenesis of both diseases.

Abstract Non-Hodgkin lymphomas (NHLs) are heterogeneous and are among the most common hematological malignancies worldwide. Despite the advances in the treatment of patients with NHLs, relapse or resistance to treatment is anticipated in several patients. Therefore, novel therapeutic approaches are needed. Recently, natural killer (NK) cell-based immunotherapy alone or in combination with monoclonal antibodies, chimeric antigen receptors, or bispecific killer engagers have been applied in many investigations for NHL treatment. The functional defects of NK cells and the ability of cancerous cells to escape NK cell-mediated cytotoxicity within the tumor microenvironment of NHLs, as well as the beneficial results from previous studies in the context of NK cell-based immunotherapy in NHLs, direct our attention to this therapeutic strategy. This review aims to summarize clinical studies focusing on the applications of NK cells in the immunotherapy of patients with NHL.

Jing Sang,1,2,&ast; Peng Liu,1,3,&ast; Meixiang Wang,1 Fengkuo Xu,1 Ji Ma,1 Zhigang Wei,1 Xin Ye1 1Department of Oncology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Shandong Lung Cancer Institute, Shandong Key Laboratory of Rheumatic Disease and Translational Medicine, Jinan, People’s Republic of China; 2Department of Pathology, The Affiliated Taian City Central Hospital of Qingdao University, Taian, People’s Republic of China; 3Yuncheng Central Hospital Affiliated to Shanxi Medical University, Yuncheng, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Zhigang Wei; Xin Ye, Department of Oncology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Jinan, Shandong Province, 250014, People’s Republic of China, Email weizhigang321321@163.com; yexintaian2020@163.comPurpose: Microwave ablation (MWA) is a minimally invasive technique for treating lung cancer. It can induce immune response; however, its effect on the immune microenvironment in tumor-draining lymph nodes (TdLN) is not well understood. This study aims to identify changes in the immune microenvironment in TdLN following MWA in a Lewis lung cancer (LLC) mouse model.Methods: LLC mouse model was established and followed by MWA. TdLN were collected at various time points, including pre-MWA and days 1, 2, 4, and 8 post-MWA. Flow cytometry was used to determine the frequencies of CD4+ T cells, CD8+ T cells, regulatory T (Treg) cells, natural killer (NK) cells, dendritic cells (DCs) and other immune cells in the TdLN. Certain cytokines were also detected.Results: Compared with pre-MWA, the frequency of CD4+ T cells significantly increased from day 1 to day 8 post-MWA. The frequency of CD8+ T cells decreased significantly on days 2 and 4, but no significant changes occurred on days 1 and 8. Significant decreases in the frequencies of Treg cells and Klrg1+ Treg cells were observed from day 1 to day 4. On days 4 and 8, there was a significant increase in the frequency of NK cells. The frequency of resident cDC2 significantly increased on day 4, whereas CD11b+ migratory cDCs increased on day 1. Additionally, on day 4, a notable rise was observed in the frequency of NK cells secreting IFN-γ, while on day 8, there was a significant increase in the frequency of CD8+ T cells secreting both IFN-γ and TNF-α.Conclusion: MWA of lung cancer can alter the immune microenvironment in the TdLN, triggering immune responses. These changes are particularly evident and intricate within the initial 4 days post-MWA. Treatment combined with MWA within a certain period may significantly enhance anti-tumor immunity.Keywords: microwave ablation, lung cancer, T cells, regulatory T cells, natural killer cells, dendritic cells

Abstract Natural killer (NK) cells are important immune cells in the organism and are the third major type of lymphocytes besides T cells and B cells, which play an important function in cancer therapy. In addition to retaining the tumor cell killing function of natural killer cells, natural killer cell-derived exosomes cells also have the characteristics of high safety, wide source, easy to preserve and transport. At the same time, natural killer cell-derived exosomes are easy to modify, and the engineered exosomes can be used in combination with a variety of current cancer therapies, which not only enhances the therapeutic efficacy, but also significantly reduces the side effects. Therefore, this review summarizes the source, isolation and modification strategies of natural killer cell-derived exosomes and the combined application of natural killer cell-derived engineered exosomes with other antitumor therapies, which is expected to accelerate the clinical translation process of natural killer cell-derived engineered exosomes in cancer therapy.