Decreased Natural Killer Cell Research Articles

OPG promotes lung metastasis by reducing CXCL10 production of monocyte-derived macrophages and decreasing NK cell recruitment

Lung metastasis is a critical and often fatal progression in cancer patients, with monocyte-derived macrophages (Mo-macs) playing multifaceted roles in this process. Despite the recognized importance of Mac-macs, most studies focus on these cells themselves, while the precise mechanisms through which tumor cells manipulate Mo-macs to promote metastasis remain poorly understood. We developed an invivo CRISPR screening system to identify genes involved in macrophage-dependent metastasis by depleting Mo-macs. Osteoprotegerin (OPG) was identified as the factor significantly enhances lung metastasis. We validated its function in lung metastasis by modulating the expression of OPG in an array of cell lines and performed spontaneous and experimental lung metastasis assays. Genetically engineered mice were utilized to confirm the role of RANKL-RANK signaling in OPG-mediated metastasis. Additionally, we employed different neutralizing antibodies to elucidate the roles of Mo-macs and NK cells and inhibitor to clarify the role of CXCL10 signaling. Employing invivo screening techniques, we elucidate the role of OPG, a protein secreted by cancer cells, in driving lung metastasis, contingent upon regulating Mo-mac activity. OPG blocks the signaling cascade between receptor activator of nuclear factor kappa-B ligand (RANKL) and its receptor RANK on Mo-macs, thereby hindering Mo-macs from secreting CXCL10, a chemokine crucial for recruiting natural killer (NK) cells that help control lung metastasis. Moreover, we observe an enrichment of OPG amplifications in metastatic cancer patients, and elevated levels of OPG expression in lung metastatic sites compared to paired primary breast cancer samples. Our work revealed that OPG works as a lung metastasis promoting factor by blocking the RANKL-RANK-CXCL10 axis to drive the paucity of NK cells, which could be a therapeutic target for lung metastatic cancer patients. The full list of funding supporting this study can be found in the Acknowledgements section.

Two cases of deficiency in ELF4 gene X-linked and literature review

Objective: To summarize the clinical phenotype and genetic characteristics of deficiency in ELF4 gene X-linked (DEX). Methods: A case series study was conducted to retrospectively analyze the clinical data and genetic testing results of 2 cases of DEX treated at Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and the First Hospital of Jilin University from January 2023 to April 2024. And literature up to April 2024 was searched from the PubMed database, as well as CNKI and Wanfang databases, using keywords such as "ELF4 deficiency" "deficiency in ELF4, X-linked""ELF4 gene". The main clinical manifestations and genotypes of DEX were summarized. Results: Both patients were male, with onset ages of 3 months and 3 years, respectively. Both patients presented with recurrent oral ulcers and abdominal pain. And the laboratory examination showed a significant increase in inflammatory markers. Intestinal examinations showed multiple intestinal ulcers, and both patients developed intestinal fistulas. Whole exome sequencing found ELF4 c.799C>T, p Arg267Trp and ELF4 c. 248-7G>A, both maternal variants. Based on clinical and genetic results, DEX were diagnosed. In terms of treatment, both patients underwent surgical treatment during the acute phase of the disease and received anti-tumor necrosis factor α therapy, but recurrent gastrointestinal symptoms were still observed in Patient 1, while the clinical effect in Patient 2 was still acceptable. However, the inflammatory markers in both patients were not normal even after treatment. Literature review found 18 patients including 2 patients in this study, reported in 5 English articles and no Chinese reports. Thirteen patients had disease onset age before 5. The main clinical manifestations were fever (12/17), oral ulcers (14/18), abdominal pain (8/18), diarrhea (6/18), perianal ulcers (5/17), ileum ulcers (6/16), colon ulcers (7/16), skin involvement (7/17) and recurrent infections (7/18); laboratory examinations found increased erythrocyte sedimentation rate (13/15) as well as C-reactive protein (9/9), and anemia (13/15); in terms of immunological function, there is a decrease in natural killer cells (9/15) as well as a decrease in class switching memory B cells (8/9). The main types of gene variantions were missense variantions (6/18), nonsense variantions (4/18) or frameshift variantions (3/18). Conclusions: DEX should be considered when an early-onset male patient manifested with recurrent fever, oral ulcers or mucosal ulcers, with elevated inflammatory markers, with or without recurrent infection. It is recommended to perform lymphocyte subsets analysis, gastrointestinal endoscopy and genetic testing to support the diagnosis.

Protein phosphatase 2A inhibitor modulates natural killer cell homeostasis in peripheral tissues

Although natural killer (NK) cell responses to tumor and viral infection have been studied, the mechanisms underlying NK cell homeostasis in vivo remain unclear. In this study, we demonstrate the pharmacological action of cytostatin, a protein phosphatase 2A (PP2A) specific inhibitor (PP2Ai), on NK cells in regulating NK cell homeostasis in the peripheral tissues. We found that PP2Ai treatment decreased NK cell percentages in the bone marrow and secondary lymphoid tissues while increasing NK cell percentages in peripheral tissues such as the lung and liver. In the peripheral tissues of PP2Ai-treated mice, Ki-67 expression and BrdU uptake in NK cells were upregulated, and an initial increase in the pre-mature CD11bhiCD27hi NK subset was observed, followed by an increase in the terminally differentiated mature CD11bhiCD27lo NK subset. In addition, bone marrow Ki-67+ NK cells predominantly expressed CX3CR1 in the PP2Ai-treated mice and were further mobilized to the peripheral tissues. Among various target molecules of PP2A, we found that the upregulation of c-Myc pathway and its phosphorylation, along with its downstream cyclin E expression and G1/S cell cycle transition in PP2Ai-treated mice NK cells. Our results suggest that PP2Ai modulates NK cell proliferation through c-Myc and cyclin E, leading to their maturation and trafficking from the bone marrow to the peripheral tissues.

Addition of CD14 improves discrimination of lymphocytes in the TBNK phenotyping panel.

Peripheral blood lymphocyte phenotyping panels typically include CD45 for discrimination of the lymphocyte population, and fluorophore-conjugated monoclonal antibodies to identify T, B, and Natural Killer (NK) cells. While CD45 combined with side scatter is generally sufficient to clearly distinguish lymphocytes from monocytes in the majority of peripheral blood samples, it is challenging to accurately gate lymphocytes in samples from patients with monocytosis or significant lymphopenia, or from very young infants. Addition of a monocyte marker to lymphocyte phenotyping panels for monocyte exclusion has previously been evaluated for improved discrimination of lymphocytes, albeit largely in healthy donor adult samples. Here we evaluate the effect of the addition of CD14 to a standard lymphocyte phenotyping panel on total lymphocyte, T, B, and NK cell percentages in a predominantly pediatric population of patients under evaluation chiefly for immunodeficiency, immune-depletion, or immune reconstitution. Addition of CD14 to the standard lymphocyte phenotyping improved discrimination of lymphocytes from monocytes, resulted in decreased NK cell percentages, likely because CD16+ and/or CD56+ monocytes were included in the CD56+CD16+ NK cell gate with conventional gating, and although less significant, resulted in an increased percentage of B cells, since relatively larger B cells were likely gated out by more restrictive light scatter gating used with the conventional gating approach. The change in NK and B cell percentages were more pronounced in samples from patients below a year of age, and in patients who were relatively lymphopenic. These data suggest that addition of CD14 to conventional lymphocyte phenotyping panels that utilize CD45 versus side scatter gating results in significant improvement in the accuracy of lymphocyte gating, and accurate quantification of NK and B cells particularly in samples from infants and lymphopenic individuals.

Epigenetic drug screen of natural killer cells identified compounds controlling immune training and tolerance

Abstract Natural killer (NK) cells are cytotoxic innate lymphocytes that provide defense against pathogens and malignancy. New evidence identified that NK cells are capable of memory-like immune responses in certain settings. This innate immune memory is thought to be imprinted through epigenetic modifications. However, precise epigenic pathways or strategies to modulate long-term NK cell activity are not well defined. In this study, we performed a screen of an epigenetic library containing 160 drug compounds with well-characterized epigenetic regulatory mechanisms, to identify drugs and pathways that could train or tolerize NK cell activation. One compound that we identified was the H3K27 methyltransferase Ezh2, which regulated NK cell lineage commitment from bone marrow hematopoietic stem cells and altered the phenotype of differentiated NK cells to increased cytotoxicity. This outcome provides an option to train or induce stronger cytotoxic effects on NK cells. In contrast, another compound we identified was the histone deacetylase inhibitor, Givinostat, which did not alter NK cell commitment from bone marrow stem cells, but significantly decreased NK cell function in the periphery resulting in a more tolerant innate immune state to secondary NK cell stimulation. Identification and exploration of these epigenome altering drugs may offer further insight into downstream pathways of NK cell function or provide novel therapies for tolerizing or priming innate immune responses.

MEF2C regulates NK cell effector functions through control of lipid metabolism.

Natural killer (NK) cells are a critical first line of defense against viral infection. Rare mutations in a small subset of transcription factors can result in decreased NK cell numbers and function in humans, with an associated increased susceptibility to viral infection. However, our understanding of the specific transcription factors governing mature human NK cell function is limited. Here we use a non-viral CRISPR-Cas9 knockout screen targeting genes encoding 31 transcription factors differentially expressed during human NK cell development. We identify myocyte enhancer factor 2C (MEF2C) as a master regulator of human NK cell functionality ex vivo. MEF2C-haploinsufficient patients and mice displayed defects in NK cell development and effector function, with an increased susceptibility to viral infection. Mechanistically, MEF2C was required for an interleukin (IL)-2- and IL-15-mediated increase in lipid content through regulation of sterol regulatory element-binding protein (SREBP) pathways. Supplementation with oleic acid restored MEF2C-deficient and MEF2C-haploinsufficient patient NK cell cytotoxic function. Therefore, MEF2C is a critical orchestrator of NK cell antiviral immunity by regulating SREBP-mediated lipid metabolism.

BIOM-42. LONGITUDINAL IMMUNE PROFILES OF LOWER GRADE ADULT GLIOMA PATIENTS

Abstract Immune dysregulation is a known characteristic of glioma, however there is little known about the peripheral immune status of lower-grade (LrGG) glioma patients across the course of disease. Using immunomethylomic (deconvoluted blood DNA methylation) data from the UCSF Immune Profiles Study, we explore changes in patient peripheral blood immune cell profiles in newly diagnosed and recurrent LrGG patients. For patients receiving radiation (RT) and temozolomide (TMZ) (n = 75), blood is collected pre-RT/TMZ, post-RT/TMZ, before, during, and after adjuvant TMZ (if applicable). For patients followed only by MRI (n = 53) and those with other treatment plans (n = 67), blood is collected at MRIs, and if applicable, before radiation. For all patients, blood is also collected before new treatment intervention. For patients (LrGG IDH mutated) with paired pre- and post-surgery samples (n = 139), we observed a significant post-surgery increase in the count of memory B-cells (p = 1.7e-5), neutrophils (p = 0.0001), basophils (p = 8.7e-5), monocytes (p = 0.0001), and T-regulatory cells (p = 0.0001) along with a significant decrease in natural killer cells (p = 0.0003). Treatment was also associated with altered patient immune profiles. The use of dexamethasone was associated with an increased count of B-memory (p = 0.0001) and B-naïve cells (p = 0.0001), monocytes (p = 2.1e-5), and neutrophils (p = 3.7e-6) post-surgery. Patients receiving chemoradiation (n = 12) exhibited significant and temporally sustained decreases in B-memory (p < 0.0001), B-naïve (p = 0.005), CD4 naïve cells (p = 0.002), and in neutrophils (p = 0.001). Patient follow-up, data collection, and further analyses are ongoing. These results shed light on the dynamic and variable immune changes in LrGG patients and provide a guide for future prognostic and therapeutic studies.

Accelerated epigenetic aging and decreased natural killer cells based on DNA methylation in patients with untreated major depressive disorder

Major depressive disorder (MDD) is known to cause significant disability. Genome-wide DNA methylation (DNAm) profiles can be used to estimate biological aging and as epigenetic clocks. However, information on epigenetic clocks reported in MDD patients is inconsistent. Since antidepressants are likely confounders, we evaluated biological aging using various DNAm-based predictors in patients with MDD who had never received depression medication. A publicly available dataset consisting of whole blood samples from untreated MDD patients (n = 40) and controls (n = 40) was used. We analyzed five epigenetic clocks (HorvathAge, HannumAge, SkinBloodAge, PhenoAge, and GrimAge), DNAm-based telomere length (DNAmTL), and DNAm-based age-related plasma proteins (GrimAge components), as well as DNAm-based white blood cell composition. The results indicate that patients with untreated MDD were significantly associated with epigenetic aging acceleration in HannumAge and GrimAge. Furthermore, a decrease in natural killer cells, based on DNAm, was observed in patients with untreated MDD.

Decreased NK cells in cases of severe adenovirus pneumonia with liver dysfunction in pediatric intensive care unit: Evidence from 330 patients.

Although the human adenovirus infection is common, adenovirus infection with liver dysfunction is rare. To retrospectively analyze and compare the clinical characteristics and outcomes of pediatric patients diagnosed with severe adenovirus pneumonia with and without liver dysfunction, who were admitted to the pediatric intensive care unit of Hunan Children's Hospital (South China University) between January 2018 and June 2022. Of the 330 severe adenovirus pneumonia cases analyzed (mean age, 19.88 ± 18.26 months), 102 were girls and 228 were boys. They were divided into two groups: those with liver dysfunction (n = 54) and without liver dysfunction (n = 276). Comparison analysis showed no significant between-group differences in body mass index and levels of white blood cells, neutrophils, platelets, albumin, total bilirubin, direct bilirubin, indirect bilirubin, creatine kinase, procalcitonin, creatinine, and urea nitrogen. However, the levels of alanine aminotransferase (175.99 U/L vs 30.55 U/L) and aspartate transaminase (215.96 U/L vs 74.30 U/L) were significantly higher in patients with liver dysfunction compared to those without liver dysfunction. Further analysis showed that pediatric patients with liver dysfunction had a significantly lower percentage of natural killer (NK) cells (6.93% vs 8.71%) and higher mortality rate (22% vs 9%) than those without liver dysfunction. A decrease in serum NK cell levels in pediatric patients with severe adenovirus pneumonia could serve as a marker for monitoring the onset or progression of hepatic damage.

Elucidating the role played by the NKG2 family of receptors in natural killer cell responses to JC polyomavirus

Abstract JC polyomavirus (JCPyV) causes progressive multifocal leukoencephalopathy (PML), a potentially fatal complication of severe immune suppression due to monoclonal antibody treatments for cancer, autoimmune diseases and transplantation, or due to uncontrolled HIV infection. There is currently no effective treatment against PML and novel immunotherapies are urgently needed. Natural killer (NK) cells play critical roles in defense against viral infections, yet NK cell responses to JCPyV remain largely unexplored. Here, we first compared NK and T cell responses against JCPyV VP1 peptide pools by intracellular cytokine staining. In about 40% of healthy donors, we detected robust CD107a upregulation and IFNγ production by NK cells, extending beyond T cell responses. Next, using a novel flow cytometry-based killing assay, we showed that co-culture of NK cells and JCPyV-infected SVG-A cells led to a 65% reduction in infection, on average. To identify receptor-ligand interactions modulating NK cell-mediated responses to JCPyV, we performed co-cultures in the presence of select blocking antibodies. We observed enhanced expression of ligands for the activating NKG2D on infected cells and accordingly, NKG2D blockade resulted in decreased NK cell degranulation. In contrast, blockade of inhibitory NKG2A enhanced NK cell response to JCPyV-infected targets. Moreover, we identified JCPyV-derived peptides that elicit dominant NK cell responses and can stabilize HLA-E, the ligand for NKG2A and the activating NKG2C. Altogether, these findings suggest that modulation of NKG2D and NKG2A/C signaling may play key roles in NK cell-mediated control of JCPyV and may be promising immunotherapeutic targets to boost NK cell anti-JCPyV activity. Supported by grant from NIH (R01 NS116278)

Upregulated complement receptors correlate with Fc gamma receptor 3A-positive natural killer cells (NK) and natural killer-T cells (NKT) in neuromyelitis optica spectrum disorder. (S50.003)

Upregulated complement receptors correlate with Fc gamma receptor 3A-positive natural killer cells (NK) and natural killer-T cells (NKT) in neuromyelitis optica spectrum disorder. (S50.003)

DOCK2 Mutation and Recurrent Hemophagocytic Lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome resulting from uncontrolled hyper-inflammation, excessive immune system activation, and elevated levels of inflammatory cytokines. HLH can be caused by the inability to downregulate activated macrophages by natural killer (NK) and CD8 cytotoxic T cells through a process reliant on perforin and granzyme B to initiate apoptosis. Homozygous genetic mutations in this process result in primary HLH (pHLH), a disorder that can lead to multi-system organ failure and death in infancy. Heterozygous, dominant-negative, or monoallelic hypomorphic mutations in these same genes can cause a similar syndrome in the presence of an immune trigger, leading to secondary HLH (sHLH). A genetic mutation in a potential novel HLH-associated gene, dedicator of cytokinesis 2 (DOCK2), was identified in a patient with recurrent episodes of sHLH and hyperinflammation in the setting of frequent central line infections. He required baseline immune suppression for the prevention of sHLH, with increased anti-cytokine therapies and corticosteroids in response to flares and infections. Using a foamy-virus approach, the patient's DOCK2 mutation and wild-type (WT) control DOCK2 cDNA were separately transduced into a human NK-92 cell line. The NK-cell populations were stimulated with NK-sensitive K562 erythroleukemia target cells in vitro and degranulation and cytolysis were measured using CD107a expression and live/dead fixable cell dead reagent, respectively. Compared to WT, the patient's DOCK2 mutation was found to cause significantly decreased NK cell function, degranulation, and cytotoxicity. This study speaks to the importance of DOCK2 and similar genes in the pathogenesis of sHLH, with implications for its diagnosis and treatment.

Tumor immune microenvironment analysis of non-small cell lung cancer development through multiplex immunofluorescence.

Emerging evidence has underscored the crucial role of infiltrating immune cells in the tumor immune microenvironment (TIME) of non-small cell lung cancer (NSCLC) development and progression. With the implementation of screening programs, the incidence of early-stage NSCLC is rising. However, the high risk of recurrence and poor survival rates associated with this disease necessitate a deeper understanding of the TIME and its relationship with driver alterations. The aim of this study was to provide an in-depth analysis of immune changes in early-stage NSCLC, highlighting the significant transitions in immune response during disease progression. Tumor tissues were collected from 105 patients with precancerous lesions or stage I-III NSCLC. Next-generation sequencing (NGS) was used to detect cancer driver alterations. Multiplex immunofluorescence (mIF) was performed to evaluate immune cell density, percentage, and spatial proximity to cancer cells in the TIME. Next Among these patients, 64 had NGS results, including three with adenocarcinoma in situ (AIS), 10 with minimally invasive adenocarcinoma (MIA), and 51 with stage I invasive cancers. Additionally, three patients underwent neoadjuvant immuno-chemotherapy and tumor tissue specimens before and after treatment were obtained. Patients with stage I invasive cancer had significantly higher density (P=0.01) and percentage (P=0.02) of CD8+ T cells and higher percentages of M1 macrophages (P=0.04) and immature natural killer (NK) cells (P=0.041) in the tumor parenchyma compared to those with AIS/MIA. Patients with mutated epidermal growth factor receptor (EGFR) gene exhibited decreased NK cell infiltration, increased M2 macrophage infiltration, and decreased aggregation of CD4+ T cells near tumor cells compared to EGFR wild-type patients. As NSCLC progressed from stage I to III, CD8+ T cell density and proportion increased, while PD-L1+ tumor cells were in closer proximity to PD-1+CD8+ T cells, potentially inhibiting CD8+ T cell function. Furthermore, M1 macrophages decreased in density and proportion, and the number of NK cells, macrophages, and B cells around tumor cells decreased. Additionally, patients with tertiary lymphoid structures (TLSs) had significantly higher proportion of M1 macrophages and lymphocytes near tumor cells, whereas those without TLS had PD-L1+ tumor cells more densely clustered around PD-1+CD8+ T cells. Notably, neoadjuvant immuno-chemotherapy induced the development of TLS. This study offers an in-depth analysis of immune changes in NSCLC, demonstrating that the transition from AIS/MIA to invasive stage I NSCLC leads to immune activation, while the advancement from stage I to stage III cancer results in immune suppression. These findings contribute to our understanding of the molecular mechanisms underlying early-stage NSCLC progression and pave the way for the identification of potential treatment options.

Upregulated complement receptors correlate with Fc gamma receptor 3A-positive natural killer and natural killer-T cells in neuromyelitis optica spectrum disorder

Background and objectivesInhibition of terminal complement in neuromyelitis optica spectrum disorder (NMOSD) using eculizumab helps prevent relapses, but the exact mechanism of action of the drug remains unclear. Similarly, genetic variants in the Fc Gamma receptor 3A (FCGR3A), also known as CD16, are correlated with outcomes in NMOSD, but the immune cells expressing those CD16 are unknown. We compared CD16 expression on immune cells modulated by complement activity in natural killer (NK) cells and natural killer-T (NKT) cells in NMOSD to disease and normal-healthy controls.MethodsPeripheral blood cell (PBMC) samples from 45 patients with NMOSD with aquaporin 4 (AQP4)-IgG, 18 disease controls, and 19 normal controls were analyzed for CD16 expression and complement receptors in vitro.ResultsAt baseline, the number of NKT cells was increased in NMOSD (p < 0.001), but the proportion that was CD16 positive was lower compared to normal and disease controls (p = 0.0012). NK cell count was normal, but the ratio that was CD16 positive was also significantly lower (p < 0.001). In both NK cells and NKT cells from NMOSD, C5 complement receptor expression was much higher than normal and disease controls (p < 0.001 for both). We also evaluated activation markers CD69 and CD83, which were also significantly higher in NK and NKT cells from NMOSD patients. FCGR3A p158 V/V genotype group in NMOSD patients showed decreased NK cell proportion with activation, and fewer CD16-expressing NKT cells than the F/F genotype group.DiscussionOur results support an immunopathogenesis model in which complement pathway activation in NK/NKT cells upregulates CD16 expression that binds to antibody/antigen complexes. In the context of NMOSD, these complement-sensitive cells may be responsible for the escalating autoimmune activity.

Hemophagocytic Lymphohistiocytosis.

Hemophagocytic Lymphohistiocytosis.

TXNIP Promotes Human NK Cell Development but Is Dispensable for NK Cell Functionality.

The ability of natural killer (NK) cells to kill tumor cells without prior sensitization makes them a rising player in immunotherapy. Increased understanding of the development and functioning of NK cells will improve their clinical utilization. As opposed to murine NK cell development, human NK cell development is still less understood. Here, we studied the role of thioredoxin-interacting protein (TXNIP) in human NK cell differentiation by stable TXNIP knockdown or overexpression in cord blood hematopoietic stem cells, followed by in vitro NK cell differentiation. TXNIP overexpression only had marginal effects, indicating that endogenous TXNIP levels are sufficient in this process. TXNIP knockdown, however, reduced proliferation of early differentiation stages and greatly decreased NK cell numbers. Transcriptome analysis and experimental confirmation showed that reduced protein synthesis upon TXNIP knockdown likely caused this low proliferation. Contrary to its profound effects on the early differentiation stages, TXNIP knockdown led to limited alterations in NK cell phenotype, and it had no effect on NK cell cytotoxicity or cytokine production. Thus, TXNIP promotes human NK cell differentiation by affecting protein synthesis and proliferation of early NK cell differentiation stages, but it is redundant for functional NK cell maturation.

Teasing Out the Interplay Between Natural Killer Cells and Nociceptor Neurons.

Somatosensory neurons have evolved to detect noxious stimuli and activate defensive reflexes. By sharing means of communication, nociceptor neurons also tune host defenses by controlling the activity of the immune system. The communication between these systems is mostly adaptive, helping to protect homeostasis, it can also lead to, or promote, the onset of chronic diseases. Both systems co-evolved to allow for such local interaction, as found in primary and secondary lymphoid tissues and mucosa. Recent studies have demonstrated that nociceptors directly detect and respond to foreign antigens, immune cell-derived cytokines, and microbes. Nociceptor activation not only results in pain hypersensitivity and itching, but lowers the nociceptor firing threshold, leading to the local release of neuropeptides. The peptides that are produced by, and released from, the peripheral terminals of nociceptors can block the chemotaxis and polarization of lymphocytes, controlling the localization, duration, and type of inflammation. Recent evidence shows that sensory neurons interact with innate immune cells via cell-cell contact, for example, engaging group 2D (NKG2D) receptors on natural killer (NK) cells. Given that NK cells express the cognate receptors for various nociceptor-produced mediators, it is conceivable that nociceptors use neuropeptides to control the activity of NK cells. Here, we devise a co-culture method to study nociceptor neuron-NK cell interactions in a dish. Using this approach, we found that lumbar nociceptor neurons decrease NK cell cytokine expression. Overall, such a reductionist method could be useful to study how tumor-innervating neurons control the anticancer function of NK cells and how NK cells control the elimination of injured neurons.

P53 missense mutant G242A subverts natural killer cells in sheltering mouse breast cancer cells against immune rejection

Cancer cells acquire immunoediting ability to evade immune surveillance and thus escape eradication. It is widely known that mutant proteins encoded from tumor suppressor TP53 exhibit gain-of-function in cancer cells, thereby promoting progression; however, how mutant p53 contributes to the sheltering of cancer cells from host anticancer immunity remains unclear. Herein, we report that murine p53 missense mutation G242A (corresponding to human G245A) suppresses the activation of host natural killer (NK) cells, thereby enabling breast cancer cells to avoid immune assault. We found that serial injection of EMT6 breast cancer cells that carry wild-type (wt) Trp53, like normal fibroblasts, promoted NK activity in mice, while SVTneg2 cells carrying Trp53 G242A+/+ mutation decreased NK cell numbers and increased CD8+ T lymphocyte numbers in spleen. Innate immunity based on NK cells and CD8 T cells was reduced in p53 mutant-carrying transgenic mice (Trp53 R172H/+, corresponding to human R175H/+). Further, upon co-culture with isolated NK cells, EMT6 cells substantively activated NK cells and proliferation thereof, increasing interferon-gamma (IFN-γ) production; however, SVTneg2 cells suppressed NK cell activation. Further mechanistic study elucidated that p53 can modulate expression by cancer cells of Mult-1 and H60a, which are activating and inhibitory ligands for NKG2D receptors of NK cells, respectively, to enhance immune surveillance against cancer. Our findings demonstrate that wt p53 is requisite for NK cell-based immune recognition and elimination of cancerous cells, and perhaps more importantly, that p53 missense mutant presence in cancer cells impairs NK cell-attributable responses, thus veiling cancerous cells from host immunity and enabling cancer progression.

Upregulation of Cytotoxic T-cells in pediatric patients with Gaucher disease

Cytotoxic (CD8) T-cells and natural killer (NK) cells have a significant immune function role. The ongoing stimulation of immunity and the excessive release of proinflammatory cytokines observed in pediatric patients with Gaucher disease (GD) can affect immune cells. Few studies have looked at the proportion of cytotoxic CD8 T-cells and their subsets in children with GD. A prospective case–control study was performed involving twenty pediatric patients with type 1 GD and twenty healthy age-matched controls. All patients received regular enzyme replacement therapy (ERT) for at least 6 months before the study. Complete blood count and flow cytometric analyses of CD8 T, Tc1, Tc2, NK, and NK T-cells were performed. GD patients showed significantly increased of CD8 T, Tc1 and significantly decreased NK cells frequencies when compared to healthy controls. However, no significant difference in Tc2 and NK T-cells was found between the studied groups. GD patients on regular ERT have increased CD8+ T-cell frequencies, predominantly Tc1, together with a reduction in NK cells than in healthy controls. These crucial immunological changes may contribute to some extent to the pathogenesis and the progression of GD.

Reduced NK Cell Cytotoxicity by Papillomatosis-Derived TGF-β Contributing to Low-Risk HPV Persistence in JORRP Patients

The role of natural killer (NK) cells in juvenile-onset recurrent respiratory papillomatosis (JORRP) patients remains elusive. In this study, we find increased NK cell percentage, particularly CD11b-CD27- (DN) subsets in peripheral blood of JORRP patients and associated with disease activity. RNA sequencing shows a downregulated “natural killer cell-mediated cytotoxicity” feature in JORRP tumors. We also find impaired cytotoxic capacity and lower expression of NK cell-activating receptors including NKp30 and NKp46. Higher transforming growth factor-beta 1 (TGF-β1) is found both in plasma and tumor tissues of JORRP, and anti-TGF-β1 antibody could restore NK cell cytolytic activity and upregulate NKp30 and NKG2D expression. Also, we find a significantly higher Chemokine receptor type 6 (CXCR6) on NK cells in tumors compared with that in peripheral blood. Finally, RT-PCR analysis show that both HPV6-E6-E7 and HPV11-E6-E7 overexpression leads to higher TGFB1 expression compared with control SNU-1076 cell line, and higher CXCR6 expression is detected on NK coculture with HPV11-E6-E7-overexpressing cells. In conclusion, we demonstrate that TGF-β1 by papillomatosis leads to decreased NK cell cytotoxicity through downregulating NK cell-activating receptors in JORRP patients.