High Natural Killer Research Articles

Prognostic significance of early nk cell recovery in pediatric t-cell replete allogeneic hematopoietic stem cell transplantation.

Early immune reconstitution, particularly of natural killer (NK) cells with strong graft-versus-leukemia effects, is crucial for the prognosis of patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). This retrospective study examined 122 pediatric patients with acute lymphoblastic leukemia (ALL) or acute myeloid leukemia (AML) who underwent T-cell replete allo-HSCT at the Children's Hospital of Soochow University from 2019 to 2021. Peripheral blood lymphocyte counts on days 30 and 60 post-transplant were analyzed, focusing on NK cell recovery and its impact on overall survival (OS), relapse-free survival (RFS), non-relapse mortality (NRM), relapse, graft-versus-host disease, and CMV reactivation. Patients were categorized into high and low NK cell groups by the median NK cell counts at day 30 (NK30) and day 60 (NK60) after HSCT. Patients with high NK30 and NK60 levels had significantly better 3-year OS rates compared to their respective low NK count groups (86.8% ± 4.7% versus 67.6% ± 7.0%, P = 0.046; 95.7% ± 3.0% versus 63.7% ± 8.7%, P < 0.001, respectively). NK60 was found to be an independent predictor for 3-year OS and RFS in multivariate analysis. Early NK reconstitution was also related to lower NRM rates. However, this correlation disappeared in patients with ALL and those undergoing haploidentical transplantation. In addition, A positive association between early T cell and NK cell reconstitution was found in our study. Higher NK cell counts on days 60 can predict superior OS, RFS and lower NRM in pediatric AML allo-HSCT patients.

Effect of preoperative natural killer cell on postoperative pulmonary complications in patients of lung cancer − A single-center retrospective cohort study

BackgroundThe effect of preoperative natural killer (NK) cell abnormalities on postoperative pulmonary complications (PPCs) after thoracoscopic radical resection of lung cancer is still unclear. The main purpose of this study was to investigate the relationship between the preoperative NK cell ratio and PPCs. MethodsThe patients who underwent thoracoscopic radical resection for lung cancer were divided into a normal group and an abnormal group according to whether the proportion of preoperative NK cells was within the reference range. The main outcome was the incidence of PPCs during postoperative hospitalization. The demographic and perioperative data were collected. Propensity score matching was used to exclude systematic bias. Univariate logistic regression was used to test the relationship between the preoperative NK cell ratio and the incidence of PPCs. The restrictive cubic spline curve was used to analyze the dose–effect relationship between the preoperative NK cell ratio and the incidence of PPCs. ResultsA total of 4161 patients were included. After establishing a matching cohort, 910 patients were included in the statistical analysis. The incidence of PPCs in the abnormal group was greater than that in the normal group (55.2% vs. 31.6%). The incidence of PPCs first decreased and then increased with increasing NK cell ratio. The proportion of patients with Grade 3 or higher PPCs in the normal group was lower than that in the abnormal group [108 (23.7%) vs. 223 (49%)]. The indwelling time of the thoracic drainage tube in the abnormal group was longer than that in the normal group [3 (3, 4) vs. 3 (3, 5)]. A preoperative abnormal NK cell ratio constituted a risk factor for PPCs in each subgroup. ConclusionLung cancer patients with an abnormal proportion of peripheral blood NK cells before surgery were more likely to develop PPCs, their disease degree was more severe, and they had a prolonged duration of chest tube indwelling. Compared with those with abnormally high NK cell ratios, those with abnormally low NK cell ratios had more pronounced PPCs.

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

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

Density of tumor-infiltrating NK and Treg cells is associated with 5 years progression-free and overall survival in resected lung adenocarcinoma

Surgical resection of pulmonary adenocarcinoma is considered to be curative but progression-free survival (PFS) has remained highly variable. Antitumor immune response may be important, however, the prognostic significance of tumor-infiltrating natural killer (NK) and regulatory T (Treg) lymphocytes is uncertain. Resected pulmonary adenocarcinoma tissues (n = 115) were studied by immunohistochemical detection of NKp46 and FoxP3 positivity to identify NK and Treg cells, respectively. Association of cell densities with clinicopathological features and progression-free survival (PFS) as well as overall survival (OS) were analyzed with a follow-up time of 60 months. Both types of immune cells were accumulated predominantly in tumor stroma. NK cell density showed association with female gender, non-smoking and KRAS wild-type status. According to Kaplan-Meier analysis, PFS and OS proved to be longer in patients with high NK or Treg cell densities (p = 0.0293 and p = 0.0375 for PFS, p = 0.0310 and p = 0.0448 for OS, respectively). Evaluating the prognostic effect of the combination of NK and Treg cell density values revealed that PFS and OS were significantly longer in NKhigh/Treghigh cases compared to the other groups combined (p = 0.0223 and p = 0.0325, respectively). Multivariate Cox regression analysis indicated that high NK cell density was independent predictor of longer PFS while high NK and high Treg cell densities both proved significant predictors of longer OS. The NKhigh/Treghigh combination also proved to be an independent prognostic factor for both PFS and OS. In conclusion, NK and Treg cells can be components of the innate and adaptive immune response at action against progression of pulmonary adenocarcinoma.

Circulating Immune Cells Predict Prognosis and Clinical Response to Chemotherapy in Cholangiocarcinoma.

The immune system is linked to the prognosis and response to treatment of patients with cancer. However, the clinical implication of peripheral blood immune cells in cholangiocarcinoma (CCA) remains vague. Thus, we aimed to assess whether peripheral circulating immune cells could be used as an indicator for prognosis and chemotherapeutic efficacy in CCA. The distributions of immune subsets were analyzed in peripheral blood samples from 141 patients with CCA and 131 healthy volunteers by using flow cytometry. The variation in the subset distribution in the two groups and the relationship between clinicopathological features and the subpopulations were investigated. Meanwhile, we assessed the implications of lymphocyte subsets as predictors of chemotherapy outcomes and overall survival (OS). The proportion of total lymphocytes decreased, while the percentages of activated T cells as well as CD4+CD25+ regulatory T cells (Tregs) increased in CCA. Notably, lymphocyte proportion decreased in patients with regional lymph node (N) (p=0.016) and distant metastasis (M) (p= 0.001). Furthermore, our study showed that peripheral blood lymphocyte subsets were significantly correlated with chemotherapy efficacy, with increased proportions of CD3+ cells (p=0.021) and CD4+ cells (p=0.016) in the effective group. Finally, the Kaplan-Meier analysis indicated that patients with high natural killer (NK) cell proportion might have prolonged OS (p = 0.028). The relationship between circulating immune cells with prognosis and chemotherapy response in patients with CCA highlights their potential application as an indicator of CCA prognosis and stratification of chemotherapy response.

A Novel Natural Killer Cell-related Gene Signature for Improving the Prediction of Prognosis and Immunotherapy Response in Bladder Cancer.

Bladder cancer (BLCA) is a commonly diagnosed cancer worldwide that exhibits high rates of recurrence and metastasis. Immunotherapy is increasingly being recognised in the clinical management of bladder cancer. In addition, the prospect of developing Natural Killer (NK) cell-related immunotherapy is promising in BLCA. We established and verified a prognostic signature based on NK cell-related gene expression. We then calculated the NKscore of BLCA samples and correlated it with the clinical outcomes, molecular subtypes of BLCA, tumour microenvironment (TME), and predicted efficacy of immune checkpoint inhibitors (ICI) and chemotherapy drugs to thoroughly explore the implications of the NKscore. Finally, the role of the NK signature gene HECTD1 in BLCA was verified by Quantitative Real-time PCR, Cell Counting Kit-8 Assay (CCK-8), Transwell Assay and Colony Formation Experiment. We analysed NK cell-associated genes and identified six genes with significant prognostic relevance. A high NK score significantly represents a worse prognosis. NKscore was significantly correlated with seven types of classical molecular subtype classifications of BLCA. In addition, NKscore positively correlates with NK-related immune checkpoints, suggesting that emerging NK cell immune checkpoint inhibitors, such as monalizumab, may have potential therapeutic promise for patients with high NKscore. The results of the T cell inflamed score (TIS) and tumour immune dysfunction exclusion (TIDE) score confirmed the suitability of immunotherapy for patients with a high NK score. Likewise, patients with a high NK score may be more suitable for several significant chemotherapeutic drugs. Functional experiments showed that the knockdown of HECTD1 significantly attenuated the proliferation, migration, and invasion ability of tumour cells. To sum up, the capability of our signature to predict prognosis and immunotherapy response was robust. Hopefully, these results will provide new insights for BLCA research and patient immunotherapy.

Role of High Endometrial Natural Killer Cell Concentration in Patients with Recurrent Miscarriage

Role of High Endometrial Natural Killer Cell Concentration in Patients with Recurrent Miscarriage

Abstract 1241: Enhancing NK cell therapy for head and neck cancer within the solid tumor microenvironment using a B7H3-targeting tri-specific killer engager (TriKE)

Abstract With an annual incidence rate exceeding 660,000 cases, and a death toll surpassing 325,000 per year, head and neck cancer (HNC) ranks as the seventh most common cancer in the world. Surgery, radiation and chemotherapy are used to treat HNC patients with modest and variable clinical success. However, these treatments prove less effective for human papillomavirus negative (HPV-) HNC patients, a subset of HNC patients with markedly worse prognosis. While significant advancements have been made in cancer immunotherapy over the past decade, its success also remains elusive for HNC due to factors such as the hypoxic solid tumor microenvironment (TME). To address the critical need for an improved therapeutic intervention, we leveraged the ability of natural killer (NK) cells in killing cancer cells without prior sensitization by developing a novel tri-specific killer engager (TriKE) that can direct NK cell killing of tumor within the hypoxic solid TME. The TriKE is composed of three domains: a humanized nanobody arm binding the activating receptor CD16 on NK cells, an interleukin (IL)-15 moiety that can drive expansion of NK cells, and a nanobody arm binding B7H3, a protein which high expression can be negatively correlated with overall survival of HPV- HNC patients. B7H3 is a prime target candidate because it is highly expressed on HPV- HNC cells, but minimally expressed on healthy tissues. In vitro testing using HPV- HNC patient blood samples revealed that B7H3 TriKE enhances activation (measured by NK cell degranulation and interferon-gamma production) and expansion of NK cells from these patients at levels equivalent to those observed in healthy controls. Furthermore, B7H3 TriKE is efficacious in its ability to drive high NK cell cytotoxicity in both acute (&amp;lt;48-hours) and prolonged (7-days) hypoxic (1% oxygen) models of HNC. Under acute hypoxia, B7H3 TriKE induces significantly more killing of targets by NK cells compared to IL-15 treatment, where NK cell cytotoxicity is impaired. In addition, B7H3 TriKE can boost the killing efficacy of NK cells exposed to prolonged hypoxia, surpassing limitations seen with IL-15 treatment. These findings strongly suggest that the B7H3 TriKE can bypass hypoxic suppression of NK effector functions in the solid TME. In vivo studies using immunocompromised mice engrafted with HPV- HNC cells revealed that B7H3 TriKE treatment significantly extends the survival of mice, compared to IL-15 treatment. Moreover, NK cells persisted in the blood of B7H3 TriKE-treated mice 28 days post-NK cell injection, highlighting the promising clinical translation of this immunotherapy. More in-depth characterization of NK cells from HPV- HNC patients are underway but altogether, these robust pre-clinical data present a novel avenue for the management of HNC for these patients. We plan to translate results from these studies to clinical trials in fall 2024. Citation Format: Melissa Khaw, Nicholas A. Zorko, Carly Selleck, Laura Bendzick, Zachary Davis, Peter Hinderlie, Madison Shackelford, Ann Lu, James Lim, Naomi Fujioka, Margaret MacMillan, John Wagner, Martin Felices, Jeffrey S. Miller. Enhancing NK cell therapy for head and neck cancer within the solid tumor microenvironment using a B7H3-targeting tri-specific killer engager (TriKE) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1241.

Immunomodulatory potentials of modified kombucha with pineapple by-products in aging: An ex vivo study

Kombucha is a healthy and becoming popular beverage worldwide. It is produced from tea leaves using symbiotic cultures of bacteria and yeast. Herein, we explored the use of pineapple peels and cores (by-products), as alternative ingredients for kombucha production. We examined crude pineapple kombucha (PK) for its microbial diversity, metabolites, and its impact on the cellular immune response in PBMCs older individual ex vivo. We observed a substantial shift in bacterial diversity, with higher percentages of Blautia and Lactobacillus compared with the original kombucha. This microbial variation may be attributed to the PK’s bioactive compounds. The expression of CD4+CD28null NKG2D+ senescent CD4+ T cells and pathogenic CD4+ T cells decreased, particularly in the high natural killer group 2 member D (NKG2D) expression group. This indicates the presence of bioactive substances in PK that can reduce the number of senescent CD4+ T cells. PK may be a health-promoting alternative beverage, especially for older individuals.

Combination of NK and Other Immune Markers at Early Phase Stratify the Risk of Sepsis Patients: A Retrospective Study.

Immune dysfunction plays a pivotal role in sepsis pathogenesis. Previous studies have revealed the crucial role of T cells and human leukocyte antigen-DR (HLA-DR) in sepsis. However, the function of natural killer (NK) cells remains unclear. This study aimed to investigate whether NK cells are associated with sepsis prognosis. In addition, we aimed to explore the interrelation and influence between NK and other immunological features in patients with sepsis. This retrospective, observational study included patients with sepsis from two hospitals in mainland China. The clinical characteristics and immune results during the early phase were collected. Patients were classified according to the level of immune cells to analyze the relationship between immunological features and 28-day mortality. A total of 984 patients were included in this study. Non-survivors were older and had lower levels of lymphocytes, monocytes, NK cells, HLA-DR, and T cells. Patients were classified into eight groups according to their levels of NK cells, HLA-DR, and T cells. Only patients with decreased NK and T cell counts showed a significant increase in 28-day mortality. An increase in CD8+ T cells was correlated with the alleviation of 28-day mortality only among patients with high NK cell levels. This study provides novel insights into the association between NK cells and 28-day mortality as well as the interrelation between NK cells and other immune cells in sepsis. The relationship between CD8+ T cells and 28-day mortality in sepsis is dependent on NK cell count.

Identification of novel lactic acid bacteria with enhanced protective effects against influenza virus.

Lactic acid bacteria (LAB) exert health-beneficial effects by regulating innate immunity in the intestinal tract. Due to growing health awareness, the demand for LAB and studies have focused on identifying beneficial LAB strains is increasing, especially those that stimulate innate immunity. In this study, the LAB strain D279 (NITE_BP-03645, Latilactobacillus sakei) was isolated from among 741 LAB strains that were analyzed for their ability to induce interleukin 12 (IL-12) production and was subsequently characterized. D279 induced the highest expression of IL-12 among the screened LABs. Furthermore, D279 significantly activated antiviral genes and preferentially induced interferon (IFN)λ expression in vitro, which plays a critical role in the epithelial tissue, thereby conferring strong anti-influenza potency without inflammation. However, it decreased the IFNα levels. The administration of pasteurized D279 to mice resulted in strong anti-influenza potency, with higher natural killer (NK) cell activity and a lower viral load in the lung than in the control. Importantly, none of the D279-administered mice were sacrificed during the viral infection tests. These results suggest that D279 administration confers beneficial effects by regulating innate immunity and that it may be relevant for commercial use in the future.

Sirtuin 2 up-regulation suppresses the anti-tumour activity of exhausted natural killer cells in mesenteric lymph nodes in murine colorectal carcinoma.

Natural killer (NK) cells inhibit colorectal carcinoma (CRC) initiation and progression through their tumoricidal activity. However, cumulative evidence suggests that NK cells become functionally exhausted in patients with CRC. To deepen the understanding of the mechanisms underlying CRC-associated NK cell exhaustion, we explored the expression and effect of Sirtuin 2 (Sirt2) in mesenteric lymph node (mLN) NK cells in a murine colitis-associated CRC model. Sirt2 was remarkably up-regulated in mLN NK cells after CRC induction. Particularly, Sirt2 was increased in mLN NK cells expressing high T cell immunoglobulin and mucin domain-3 (TIM3), high lymphocyte activation protein-3 (LAG3), high programmed death-1 (PD-1), high T cell immunoreceptor with immunoglobulin and ITIM domains (TIGIT), high NK group 2 member A (NKG2A), but low tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), low interferon-gamma and low granzyme B. In addition, Sirt2 was also increased in NK cells after induction of exhaustion in vitro. Lentivirus-mediated Sirt2 silencing did not affect the acute activation and cytotoxicity of non-exhausted NK cells. However, Sirt2 silencing partially restored the expression of interferon-gamma, granzyme B and CD107a in exhausted NK cells. Meanwhile, Sirt2 silencing down-regulated TIM3, LAG3, TIGIT and NKG2A while up-regulated TRAIL on exhausted NK cells. Consequently, Sirt2 silencing restored the cytotoxicity of exhausted NK cells. Moreover, Sirt2 silencing partially ameliorates the defects in glycolysis and mitochondrial respiration of exhausted NK cells, as evidenced by increases in glycolytic capacity, glycolytic reserve, basal respiration, maximal respiration and spare respiration capacity. Accordingly, Sirt2 negatively regulates the tumoricidal activity of exhausted NK cells in CRC.

High levels of NK Cells in graft are associated with reduced febrile neutropenia after haploidentical peripheral blood stem cell transplantation.

To investigate the impact of natural killer (NK) cells in the graft on the outcome following haploidentical peripheral blood stem cell transplantation (haplo-PBSCT). We retrospectively collected data from patients who had undergone haplo-PBSCT at our centre from January 2019 to November 2021. The percentage of NK cells in stem cell grafts was detected by flow cytometry. Based on the median (range) count of NK cells (1.8 [0.4-6.0] × 108/kg), patients were separated into high and low NK cell count groups. Data from 96 patients were analysed. Patients were evenly distributed (48 in each group) into high and low NK cell count groups. There was no significant difference in neutrophil and platelet recovery between the two groups. However, the rates of febrile neutropenia, bacterial infection, and invasive fungal disease (IFD) were significantly reduced in the high compared with the low NK cell count group. There was no significant difference in rates of cytomegalovirus (CMV) and Epstein-Barr virus (EBV) infections between groups. There was no significant difference between groups in grades II and above acute graft versus host disease (GVHD), progression-free survival (PFS), or overall survival (OS). A high number of NK cells in the graft may reduce febrile neutropenia, IFD and bacterial infection following haplo-PBSCT but it has no significant effect on aGVHD, PFS, or OS.

Detection of Antibody-Dependent Cell-Mediated Cytotoxicity-Supporting Antibodies by NK-92-CD16A Cell Externalization of CD107a: Recognition of Antibody Afucosylation and Assay Optimization.

Antibody-dependent cell-mediated cytotoxicity (ADCC) by natural killer (NK) lymphocytes eliminates cells infected with viruses. Anti-viral ADCC requires three components: (1) antibody; (2) effector lymphocytes with the Fc-IgG receptor CD16A; and (3) viral proteins in infected cell membranes. Fc-afucosylated antibodies bind with greater affinity to CD16A than fucosylated antibodies; individuals' variation in afucosylation contributes to differences in ADCC. Current assays for afucosylated antibodies involve expensive methods. We report an improved bioassay for antibodies that supports ADCC, which encompasses afucosylation. This assay utilizes the externalization of CD107a by NK-92-CD16A cells after antibody recognition. We used anti-CD20 monoclonal antibodies, GA101 WT or glycoengineered (GE), 10% or ~50% afucosylated, and CD20-positive Raji target cells. CD107a increased detection 7-fold compared to flow cytometry to detect Raji-bound antibodies. WT and GE antibody effective concentrations (EC50s) for CD107a externalization differed by 20-fold, with afucosylated GA101-GE more detectable. The EC50s for CD107a externalization vs. 51Cr cell death were similar for NK-92-CD16A and blood NK cells. Notably, the % CD107a-positive cells were negatively correlated with dead Raji cells and were nearly undetectable at high NK:Raji ratios required for cytotoxicity. This bioassay is very sensitive and adaptable to assess anti-viral antibodies but unsuitable as a surrogate assay to monitor cell death after ADCC.

Pan-cancer analysis of natural killer (NK) cell infiltration in human malignancies: Molecular features and clinical implications.

2563 Background: NK cells are part of the innate immune system that are not antigen-specific, but can be redirected to targets of interest using multiple strategies. Advantages of NK cells over T cells include the use of allogeneic off-the-shelf products and lower risk of cytokine release syndrome. Numerous NK-specific immunotherapies are under development for the treatment of cancer, although none are yet FDA-approved. Here, we conducted a pan-cancer analysis of NK cell abundance in &gt;90,000 tumor samples across 45 cancer types using the Caris Precision Oncology Alliance (POA) database. Features of prostate cancer (PCa, n=3365) and renal cell carcinoma (RCC, n=1106) were explored in depth. Methods: DNA (targeted/whole-exome) and RNA (whole-transcriptome) sequencing was performed for patient tumors (N=90,916) submitted to Caris Life Sciences (Phoenix, AZ). NK cell fractions were inferred from RNA-seq data using quanTIseq (Finotello, 2019). Real-world overall survival (OS) was determined from insurance claims, and Kaplan-Meier estimates were calculated. Statistical significance was determined using X2 and Mann-Whitney U tests with corrections for multiple hypothesis testing where appropriate. Results: Median NK cell fractions ranged from 7-9% (medulloblastoma and gliomas) to 2% (thyroid and thymic cancers), with intermediate levels observed for PCa (4.6%) and RCC (3.1%). High (&gt; median) NK cell fractions were associated with improved OS (hazard ratios, 0.28–0.84, p&lt;0.05) for 28 of 45 cancer types, while 16 of 45 including low-grade glioma, GIST, and thyroid had HR &lt;1.0 (0.264-0.997) with 95% CI crossing 1.0. Improved OS was notable in PCa (HR 0.46, 95% CI 0.38–0.56, p&lt;0.0001) and RCC (HR 0.52; 95% CI 0.39–0.70, p&lt;0.0001). Unexpectedly, tumors with higher NK infiltrates were less frequently PD-L1+ (SP142) by IHC in PCa (2.8% vs 5.4%, p=0.08) and RCC (12.4% vs 30.8%, p&lt;0.0001) ( i.e. an inverse relationship), despite a lack of correlation of NK infiltration with dMMR/MSI status or tumor mutation burden (TMB) in both cancers. Conversely, increased NK infiltration was associated with a 1.4- to 2.1–fold increased mRNA expression of immunomodulatory receptors LAG3 and TIGIT in both PCa (p&lt;0.0001) and RCC (p&lt;0.0001), but a 1.4–fold decrease in B7-H3 in RCC (p&lt;0.0001). Conclusions: High NK cell infiltration is associated with improved OS in numerous cancer types, including many with inadequate therapeutic options. Our findings suggest broad deployment of NK engagers and CAR-NK products in a range of malignancies. The positive correlation between NK cells and LAG3/TIGIT suggest that combination approaches may be warranted. The inverse relationship between NK infiltrates and PD-L1, and lack of association with standard immune therapy markers (MSI status, TMB), indicates the potential use of NK cell approaches in situations where other immunotherapies are ineffective.

Factors affecting BK polyomavirus infection after kidney transplantation in post-school children and a predictive infection model

Objective: To analyze high-risk factors affecting BK polyomavirus (BKPyV) infection and to construct a prediction model for BKPyV infection in children after renal transplantation. Methods: The clinical data of 332 children who received allogeneic kidney transplantation in the First Affiliated Hospital of Zhengzhou University from January 2014 to March 2022 were retrospectively collected. According to the BKPyV load level, the dynamic change process of lymphocytes at different time points were analyzed. The factors that have potential influence on BKPyV infection were screened by Cox regression analysis, and the receiver operating characteristic curve (ROC) was used to evaluate the sensitivity and specificity of the predictive model of infection. Results: Among the 332 children, there were 215 males and 117 females; the age of transplantation was (12.2±3.9) years old; 37 cases were preschool (1-5 years old), and 295 cases were post-school age (6-18 years old). BKPyV load in 224 urine samples and 30 blood samples of children were detected. There were 9 cases of BKPyV-associated viruria and 3 cases of BKPyV associated viremia in pre-school children, 76 cases BKPyV associated viruria and 14 cases of BKPyV associated viremia in post-school children. Multivariate Cox regression analysis showed that higher body mass index (BMI) (HR=1.105, 95%CI: 1.020-1.197), antithyroglobulin (ATG) application (HR=2.196, 95%CI: 1.335-3.613), and higher tacrolimus concentration (HR=2.484, 95%CI: 1.298-4.753), higher natural killer (NK) lymphocyte count (HR=1.193, 95%CI: 1.009-1.411), higher CD14++CD16-cell count (HR=1.096, 95%CI: 1.024-1.173) were independent risk factors for BKPyV associated viruria in post-school children. Delayed graft function (DGF) (HR=4.993, 95%CI: 1.555-16.038), Acute rejection (AR) (HR=6.021, 95%CI: 1.930-18.787), higher CD14++CD16-cell count (HR=1.227, 95%CI: 1.081-1.392) were independent risk factors for BKPyV associated viremia in post-school children. The results of ROC curve analysis showed that combined BMI, immune induction drugs, tacrolimus concentration, NK cell count, and CD14++CD16-cell count predicted the occurrence of BKPyV associated viruria in post-school children after kidney transplantation at 0.5, 1, 2, and 5 years with area under curve (AUC) of 0.712 (95%CI: 0.626-0.798), 0.708 (95%CI: 0.612-0.804), 0.754 (95%CI: 0.668-0.840) and 0.767 (95%CI: 0.685-0.849). The sensitivity and specificity of the model were 64.9%, 61.4%, 61.6%, 55.8% and 70.9%, 72.4%, 76.0%, 84.0%, respectively. Combined with DGF, AR, and CD14++CD16-cell counts predicted the occurrence of BKPyV-associated viremia at 0.5, 1, 2, and 5 years after renal transplantation in post-school children with AUC of 0.791 (95%CI: 0.631-0.951), 0.744 (95%CI: 0.547-0.936), 0.786 (95%CI: 0.629-0.946) and 0.812 (95%CI: 0.672-0.948). The sensitivity and specificity of the model were 76.1%, 67.1%, 75.0%, 77.9% and 88.9%, 89.0%, 89.9%, 88.0%, respectively. Conclusions: The postoperative CD14++CD16-cell level can be used as an independent predictor of BKPyV infection in post-school children after renal transplantation. Combined BMI, immune induction drugs, tacrolimus concentration, NK cell count, CD14++CD16-cell count and combined DGF, AR, CD14++CD16-cell count show good fitting effect in predicting the occurrence of BKPyV-associated viruria and viremia after transplantation in post-school children respectively.

Humanized mouse models with endogenously developed human natural killer cells for in vivo immunogenicity testing of HLA class I-edited iPSC-derived cells

Human induced pluripotent stem cells (hiPSCs) genetically depleted of human leucocyte antigen (HLA) class I expression can bypass T cell alloimmunity and thus serve as a one-for-all source for cell therapies. However, these same therapies may elicit rejection by natural killer (NK) cells, since HLA class I molecules serve as inhibitory ligands of NK cells. Here, we focused on testing the capacity of endogenously developed human NK cells in humanized mice (hu-mice) using MTSRG and NSG-SGM3 strains to assay the tolerance of HLA-edited iPSC-derived cells. High NK cell reconstitution was achieved with the engraftment of cord blood-derived human hematopoietic stem cells (hHSCs) followed by the administration of human interleukin-15 (hIL-15) and IL-15 receptor alpha (hIL-15Rα). Such “hu-NK mice” rejected HLA class I-null hiPSC-derived hematopoietic progenitor cells (HPCs), megakaryocytes and T cells, but not HLA-A/B-knockout, HLA-C expressing HPCs. To our knowledge, this study is the first to recapitulate the potent endogenous NK cell response to non-tumor HLA class I-downregulated cells in vivo. Our hu-NK mouse models are suitable for the non-clinical evaluation of HLA-edited cells and will contribute to the development of universal off-the-shelf regenerative medicine.

A new natural killer cell-specific gene signature predicting recurrence in colorectal cancer patients.

The protective role of Natural Killer (NK) cell tumour immunosurveillance has long been recognised in colorectal cancer (CRC). However, as most patients show limited intra-tumoral NK cell infiltration, improving our ability to identify those with high NK cell activity might aid in dissecting the molecular features which underlie NK cell sensitivity. Here, a novel CRC-specific NK cell gene signature that infers NK cell load in primary tissue samples was derived and validated in multiple patient CRC cohorts. In contrast with other NK cell gene signatures that have several overlapping genes across different immune cell types, our NK cell signature has been extensively refined to be specific for CRC-infiltrating NK cells. The specificity of the signature is substantiated in tumour-infiltrating NK cells from primary CRC tumours at the single cell level, and the signature includes genes representative of NK cells of different maturation states, activation status and anatomical origin. Our signature also accurately discriminates murine NK cells, demonstrating the applicability of this geneset when mining datasets generated from preclinical studies. Differential gene expression analysis revealed tumour-intrinsic features associated with NK cell inclusion versus exclusion in CRC patients, with those tumours with predicted high NK activity showing strong evidence of enhanced chemotactic and cytotoxic transcriptional programs. Furthermore, survival modelling indicated that NK signature expression is associated with improved survival outcomes in CRC patients. Thus, scoring CRC samples with this refined NK cell signature might aid in identifying patients with high NK cell activity who could be prime candidates for NK cell directed immunotherapies.

The Potential Role of Cytotoxic Immune Effectors in Amyotrophic Lateral Sclerosis (ALS); A Longitudinal Case Study Comparing Patients with Genetically Identical Healthy Twin.

Amyotrophic lateral sclerosis (ALS) is an auto-immune neurodegenerative disorder affecting the motor-neurons. The causes of ALS are heterogeneous, and are only partially understood to date. We studied percentage and function of immune cell subsets in particular natural killer (NK) and CD8+ T cells in an ALS patient and compared the results to those obtained from his genetically identical healthy twin in a longitudinal study. We found several basic mechanisms which were potentially involved in the disease induction and progression. Our findings demonstrate that ALS patient's peripheral blood contained higher NK and B cells and, lower T cell percentages compared with the healthy twin brother's peripheral blood. Significantly increased interferon-gamma secretion by anti-CD3/28 monoclonal antibody-treated peripheral blood mononuclear cells, and sorted CD8+ T cells were observed in the ALS patient, suggesting that hyper-responsiveness of T cell compartment could be a potential mechanism of ALS progression. Significant increase in NK cell function due to genetic mutations in ALS associated genes may partly be responsible for the increase expansion and function of CD8+ T cells with effector/memory phenotype, in addition to direct activation and expansion of antigen specific T cells by such mutations. Weekly N-acetyl cysteine infusion to block cell death in patient in addition to a number of other therapies listed in this paper were not effective, and even though the treatments might have extended the patient's life, it was not curative. Therefore, activated CD8+ T and NK cells are likely cells targeting motor neurons in the patient, and strategies should be designed to decrease the aggressive nature of these cells to achieve longer lasting therapeutic benefits.

Transcriptome Analysis of Tumor-Infiltrating Lymphocytes Identifies NK Cell Gene Signatures Associated With Lymphocyte Infiltration and Survival in Soft Tissue Sarcomas.

PurposeClinical successes using current T-cell based immunotherapies have been limited in soft tissue sarcomas (STS), while pre-clinical studies have shown evidence of natural killer (NK) cell activity. Since tumor immune infiltration, especially tumor-infiltrating lymphocytes, is associated with improved survival in most solid tumors, we sought to evaluate the gene expression profile of tumor and blood NK and T cells, as well as tumor cells, with the goal of identifying potential novel immune targets in STS.Experimental DesignUsing fluorescence-activated cell sorting, we isolated blood and tumor-infiltrating CD3-CD56+ NK and CD3+ T cells and CD45- viable tumor cells from STS patients undergoing surgery. We then evaluated differential gene expression (DGE) of these purified populations with RNA sequencing analysis. To evaluate survival differences and validate primary DGE results, we also queried The Cancer Genome Atlas (TCGA) database to compare outcomes stratified by bulk gene expression.ResultsSorted intra-tumoral CD3+ T cells showed significant upregulation of established activating (CD137) and inhibitory genes (TIM-3) compared to circulating T cells. In contrast, intra-tumoral NK cells did not exhibit upregulation of canonical cytotoxic genes (IFNG, GZMB), but rather significant DGE in mitogen signaling (DUSP4) and metabolic function (SMPD3, SLC7A5). Tumors with higher NK and T cell infiltration exhibited significantly increased expression of the pro-inflammatory receptor TLR4 in sorted CD45- tumor cells. TCGA analysis revealed that tumors with high TLR4 expression (P = 0.03) and low expression of STMN1 involved in microtubule polymerization (P < 0.001) were associated with significantly improved survival.ConclusionsUnlike T cells, which demonstrate significant DGE consistent with upregulation of both activating and inhibiting receptors in tumor-infiltrating subsets, NK cells appear to have more stable gene expression between blood and tumor subsets, with alterations restricted primarily to metabolic pathways. Increased immune cell infiltration and improved survival were positively correlated with TLR4 expression and inversely correlated with STMN1 expression within tumors, suggesting possible novel therapeutic targets for immunotherapy in STS.