nk cell cytotoxicity
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2022 ◽  
Vol 12 ◽  
Author(s):  
Nayoung Kim ◽  
Eunbi Yi ◽  
Soon Jae Kwon ◽  
Hyo Jin Park ◽  
Hyung-Joon Kwon ◽  
...  

Natural killer (NK) cells are innate cytotoxic lymphocytes that efficiently eliminate malignant and virus-infected cells without prior activation via the directed and focused release of lytic granule contents for target cell lysis. This cytolytic process is tightly regulated at discrete checkpoint stages to ensure the selective killing of diseased target cells and is highly dependent on the coordinated regulation of cytoskeletal components. The actin-binding protein filamin crosslinks cortical actin filaments into orthogonal networks and links actin filament webs to cellular membranes to modulate cell migration, adhesion, and signaling. However, its role in the regulation of NK cell functions remains poorly understood. Here, we show that filamin A (FLNa), a filamin isoform with preferential expression in leukocytes, is recruited to the NK cell lytic synapse and is required for NK cell cytotoxicity through the modulation of conjugate formation with target cells, synaptic filamentous actin (F-actin) accumulation, and cytotoxic degranulation, but not granule polarization. Interestingly, we also find that the loss of FLNa augments the target cell-induced expression of IFN-γ and TNF-α by NK cells, correlating with enhanced activation signals such as Ca2+ mobilization, ERK, and NF-κB, and a delayed down-modulation of the NKG2D receptor. Thus, our results identify FLNa as a new regulator of NK cell effector functions during their decision to kill target cells through a balanced regulation of NK cell cytotoxicity vs cytokine production. Moreover, this study implicates the cross-linking/bundling of F-actin mediated by FLNa as a necessary process coordinating optimal NK effector functions.


Author(s):  
Fawaz Abomaray ◽  
Arnika Kathleen Wagner ◽  
Michael Chrobok ◽  
Åsa Ekblad-Nordberg ◽  
Sebastian Gidlöf ◽  
...  

Endometriosis is an inflammatory disease that presents with ectopic endometriotic lesions. Reduced immunosurveillance of these lesions has been proposed to be playing a role in the pathology of endometriosis. Mesenchymal stromal cells (MSC) are found in ectopic lesions and may decrease immunosurveillance. In the present study, we examined if MSC contribute to reduced immunosurveillance through their immunosuppressive effects on natural killer (NK) cells. Stromal cells from endometriotic ovarian cysts (ESCcyst) and eutopic endometrium (ESCendo) of women with endometriosis and their conditioned medium were used in co-cultures with allogeneic peripheral blood NK cells. Following culture, NK cells were examined phenotypically for their expression of activating, inhibitory, maturation, and adhesion receptors and co-receptors, as well as the degranulation (CD107a) marker and the immunostimulatory (interferon-γ) and immunosuppressive (transforming growth factor beta 1 and interleukin-10) cytokines. Moreover, NK cell cytotoxicity was examined using chromium 51 release killing assays. There were no differences between ESCcyst and ESCendo regarding their effects on NK cell cytotoxicity in both conditioned medium and direct co-culture experiments. Additionally, there were no differences between ESCcyst and ESCendo regarding their impact on NK cells’ phenotype and degranulation in both conditioned medium and direct co-culture experiments. Although there were no differences found for DNAX accessory molecule-1 (DNAM-1) and NKp44, we found that the expression of the NK cell ligand CD155 that binds DNAM-1 and proliferating cell nuclear antigen (PCNA) that binds NKp44 was significantly less on ESCcyst than on ESCendo. These findings were not supported by the results that the expression of the known and unknown ligands on ESCcyst for DNAM-1 and NKp44 using chimeric proteins was not significantly different compared to ESCendo. In conclusion, the results suggest that ectopic MSC may not contribute to reduced immunosurveillance in endometriosis through their inhibitory effects on NK cells. This suggests that NK cell inhibition in the pelvic cavity of women with endometriosis develops due to other factors.


Author(s):  
Stanley Du Preez ◽  
Natalie Eaton-Fitch ◽  
Helene Cabanas ◽  
Donald Staines ◽  
Sonya Marshall-Gradisnik

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex multisystemic disorder responsible for significant disability. Although a unifying etiology for ME/CFS is uncertain, impaired natural killer (NK) cell cytotoxicity represents a consistent and measurable feature of this disorder. Research utilizing patient-derived NK cells has implicated dysregulated calcium (Ca2+) signaling, dysfunction of the phosphatidylinositol-4,5-bisphosphate (PIP2)-dependent cation channel, transient receptor potential melastatin (TRPM) 3, as well as altered surface expression patterns of TRPM3 and TRPM2 in the pathophysiology of ME/CFS. TRPM7 is a related channel that is modulated by PIP2 and participates in Ca2+ signaling. Though TRPM7 is expressed on NK cells, the role of TRPM7 with IL-2 and intracellular signaling mechanisms in the NK cells of ME/CFS patients is unknown. This study examined the effect of IL-2 stimulation and TRPM7 pharmacomodulation on NK cell cytotoxicity using flow cytometric assays as well as co-localization of TRPM7 with PIP2 and cortical actin using confocal microscopy in 17 ME/CFS patients and 17 age- and sex-matched healthy controls. The outcomes of this investigation are preliminary and indicate that crosstalk between IL-2 and TRMP7 exists. A larger sample size to confirm these findings and characterization of TRPM7 in ME/CFS using other experimental modalities are warranted.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 553-553
Author(s):  
Chitra Hosing ◽  
Zachary Braunstein ◽  
Alaa M Ali ◽  
Benigno C. Valdez ◽  
Borje S. Andersson ◽  
...  

Abstract Background: Allo-SCT is the only curative option for patients with high risk and relapsed/refractory T-cell malignancies. Even among allo-SCT recipients, survival is less than 50% and relapse rates are 55-60%. We developed a clinical trial to decrease relapse after allo-SCT for these patients using romidepsin (rom), a histone deacetylase inhibitor approved for the treatment of relapsed T-cell lymphomas. Based on pre-clinical data demonstrating enhanced and synergistic cell killing with the addition of rom to busulfan (Bu) and fludarabine (Flu) in malignant T-cells, we created a novel transplant regimen (BuFluRom). We hypothesized this regimen, coupled with maintenance rom (m-rom), would enhance malignant T-cell killing, eradicate MRD at transplant, decrease relapse, and stimulate the GVL effect by stimulating NK-cells. Here we present results of this clinical trial, with correlative data evaluating NK-cytotoxicity. This is the first trial designed specifically to treat T-cell malignancies with allo-SCT. (NCT02512497) Methods: This is a phase I/II clinical trial. Eligible patients had: a diagnosis of T-cell leukemia (including T-acute lymphoblastic leukemia) or T-cell lymphoma (cutaneous or peripheral) in at least a partial remission requiring an allo-SCT, <70 years of age, with a matched sibling/unrelated donor. The primary objective was to determine the recommended phase 2 dose (RP2D) of rom from 3 dose levels (1, 2, 3 mg/m2) when combined with BuFlu (AUC 20000 or 16000, Figure). Patients received standard tacrolimus/methotrexate GVHD prophylaxis with ATG for MUDs. Once RP2D was determined, an expansion cohort of up to 30 patients (total) was included. M-rom was initiated between day +28 and +100 for 1 year (2 years max). The effect of rom on NK-cell cytotoxicity was assessed on samples taken pre-transplant, and 1, 3, 6, 12 months post allo-SCT. NK cytotoxicity was assessed by isolating mononuclear cells from patient samples and targeting them against K562 and T-cell lymphoma targets using the calcein-AM assay. Fine-Gray models were used to estimate PFS, OS, and cumulative incidence, and compare survival curves across groups. Results: 21 patients have been enrolled (Table). One DLT was observed (VOD), at dose level 2, and the RP2D of rom in conditioning was determined to be 2 mg/m2. With a median follow-up time of 10.1 months, the median OS has not been reached (3.3-NR months), with a 1 and 3-year OS probability of 62.8% & 55.8%. The median PFS is 28.2 months (3.8-28.1), with 1 and 3 year PFS of 57% & 30.4%. Cumulative incidence (CI) of NRM at day 100 and 1 year were 14.8% and 20%. CI of grade II-IV aGHVD and extensive cGVHD were 47.6% and 18.5%. The CI of relapse (CIR) was 22.8% at 1 year (95% CI 6.6-44.9%). There was no difference between PFS among patients with MRD versus those without MRD prior to transplant (p=0.96), and no difference in 1-year CIR (p=0.9). PFS and CIR at 1 year was substantially better in the lymphoma than leukemia patients (85.7% vs 44%, p=0.049), and (0% vs 32.1%, p=0.05). No patients with PTCL relapsed, and 3/5 patients with T-PLL are alive, disease free. 13/21 (62%) of patients received m-rom with a median number of 10 cycles (range 1-41). (Table) 7 patients experienced grade 3/4 adverse events (AE), though no patients discontinued m-rom due to toxicity. NK-cytotoxicity was higher at each time point in patients who received m-rom compared to those who did not, though there were insufficient patients to reach statistical significance. When NK-cytotoxicity was assessed between the two groups after starting maintenance, NK-cytotoxicity in the m-rom group was significantly higher than in those without m-rom (p=0.05) (Figure). Conclusions: BuFluRom with m-rom is effective at decreasing relapse in patients with T-cell malignancies, with 1-year CI relapse below expected relapse rates for this set of diseases. Toxicities were similar to standard BuFlu alone and the RP2D of rom in conditioning was established at 2 m g/m2. Intriguingly, BuFluRom mitigated the poor outcomes of patients with MRD prior to transplant. Further, early data suggests m-rom enhances NK-cell cytotoxicity post allo-SCT, potentially augmenting the GVL effect and accounting for decreased relapse rates. Long-term follow-up is needed to evaluate these results, but these results suggest the BuFluRom regimen with m-rom could become a new option for patients receiving allo-SCT for T-cell malignancies to mitigate relapse. Figure 1 Figure 1. Disclosures Hosing: Nkarta Therapeutics: Membership on an entity's Board of Directors or advisory committees. Popat: Bayer: Research Funding; Abbvie: Research Funding; Novartis: Research Funding; Incyte: Research Funding. Vasu: Boehringer Ingelheim: Other: Travel support; Seattle Genetics: Other: travel support; Kiadis, Inc.: Research Funding; Omeros, Inc.: Membership on an entity's Board of Directors or advisory committees. de Lima: Miltenyi Biotec: Research Funding; Incyte: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees. William: Dova Pharmaceuticals: Research Funding; Incyte: Research Funding; Kyowa Kirin: Consultancy; Merck: Research Funding; Guidepoint Global: Consultancy. Lee: Kiadis Pharma: Divested equity in a private or publicly-traded company in the past 24 months, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Courier Therapeutics: Current holder of individual stocks in a privately-held company. Brammer: Kymera Therapeutics: Consultancy; Celgene: Research Funding; Seattle Genetics: Speakers Bureau.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Christian Kellner ◽  
Sebastian Lutz ◽  
Hans-Heinrich Oberg ◽  
Daniela Wesch ◽  
Anna Otte ◽  
...  

Abstract Natural killer group 2 member D (NKG2D) plays an important role in the regulation of natural killer (NK) cell cytotoxicity in cancer immune surveillance. With the aim of redirecting NK cell cytotoxicity against tumors, the NKG2D ligand UL-16 binding protein 2 (ULBP2) was fused to a single-chain fragment variable (scFv) targeting the human epidermal growth factor receptor 2 (HER2). The resulting bispecific immunoligand ULBP2:HER2-scFv triggered NK cell-mediated killing of HER2-positive breast cancer cells in an antigen-dependent manner and required concomitant interaction with NKG2D and HER2 as revealed in antigen blocking experiments. The immunoligand induced tumor cell lysis dose-dependently and was effective at nanomolar concentrations. Of note, ULBP2:HER2-scFv sensitized tumor cells for antibody-dependent cell-mediated cytotoxicity (ADCC). In particular, the immunoligand enhanced ADCC by cetuximab, a therapeutic antibody targeting the epidermal growth factor receptor (EGFR) synergistically. No significant improvements were obtained by combining cetuximab and anti-HER2 antibody trastuzumab. In conclusion, dual-dual targeting by combining IgG1 antibodies with antibody constructs targeting another tumor associated antigen and engaging NKG2D as a second NK cell trigger molecule may be promising. Thus, the immunoligand ULBP2:HER2-scFv may represent an attractive biological molecule to promote NK cell cytotoxicity against tumors and to boost ADCC.


2021 ◽  
Vol 12 ◽  
Author(s):  
ZhongJun Su ◽  
JieXiu Zhao

Objective: To compare the effects of Tai Chi and Square dance on immune function, physical health, and life satisfaction in urban, empty-nest older adults.Methods: This cross-sectional study included 249 older adults (60–69 years) who were categorized into Tai Chi (n = 81), Square dance (n = 90), and control groups (n = 78). We evaluated immunoglobulin G (IgG) and interleukin-2 (IL-2) levels by enzyme-linked immunosorbent assay (ELISA), natural killer (NK) cell cytotoxicity by MTT assay, physical health indices by physical fitness levels, and life satisfaction by Life Satisfaction Index A (LSIA) scores.Results: Immune function, physical health, and life satisfaction in older adults in the Tai Chi and Square dance groups were significantly better than those in the control group (P < 0.05). Regarding immune function and physical health, the Tai Chi group exhibited significantly higher levels of IgG (15.41 ± 0.26 g/L vs. 11.99 ± 0.35 g/L, P < 0.05), IL-2 (4.60 ± 0.20 ng/mL vs. 4.45 ± 0.21 ng/mL, P < 0.05), and NK cell cytotoxicity (0.28 ± 0.02 vs. 0.22 ± 0.02, P < 0.05) than the square dance group, significantly lower waist-to-hip ratio (0.87 ± 0.02 vs. 0.89 ± 0.02, P < 0.05), resting pulse (78.4 ± 4.6 beats/min vs. 81.0 ± 3.1 beats/min, P < 0.05), systolic blood pressure (132.0 ± 5.2 mmHg vs. 136.2 ± 3.2 mmHg, P < 0.05), diastolic blood pressure (80.0 ± 2.6 mmHg vs. 83.0 ± 2.7 mmHg, P < 0.05), and significantly higher vital capacity (2978.0 ± 263.0 mL vs. 2628.3 ± 262.8 mL, P < 0.05) and duration of one-leg standing with eyes closed (16.2 ± 1.9 s vs. 12.0 ± 1.7 s). However, there was no significant difference in LSIA scores between the Tai Chi and Square dance groups (12.05 ± 1.96 vs. 13.07 ± 1.51, P > 0.05). Further, there was a significant correlation between LSIA scores and immune function (r = 0.50, P = 0.00) and physical health (r = 0.64, P = 0.00).Conclusion: (1) Both Tai Chi and square dance practitioners had better health outcomes, compared with sedentary individuals; (2) Tai Chi practitioners had better physical health and immune function than Square dance practitioners. (3) Tai Chi and Square dance exercises had similar effects on life satisfaction among urban empty-nest older adults.Suggestions: For urban empty-nest older adults who want to have better physical health and immune function, long-term Tai Chi exercise may be a better choice; however, those who are concerned about life satisfaction can choose either Tai Chi or Square dance exercise.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Meng Wang ◽  
Bo Zhang

Exosomes are lipid bilayer particles that originated from almost all types of cells and play an important role in intercellular communication. Tumor-derived exosomes contain large amounts of noncoding RNA, DNA, and proteins, which can be transferred into recipient cells as functional components in exosomes. These exosomal functional constituents depend on the originating cells, and it has been proved that types and numbers of exosomal components differ in cancer patients and healthy individuals. This review summarizes the role of tumor-derived exosomes in immunomodulation and discusses the application of exosomes in immunotherapy in cancers. Overall, exosomes isolated from cancer cells are turned out to promote immune evasion and interfere with immune responses in tumors through inducing apoptosis of CD8+ T cells, facilitating generation of Tregs, suppressing natural killer (NK) cell cytotoxicity, inhibiting maturation and differentiation of monocyte, and enhancing suppressive function of myeloid-derived suppressor cells (MDSCs). Mechanistically, exosomal functional components play a significant role in the immunomodulation in cancers. Moreover, based on the existing studies, exosomes could potentially serve as therapeutic delivery vehicles, noninvasive biomarkers, and immunotherapeutic vaccines for various types of cancers.


2021 ◽  
Vol 12 ◽  
Author(s):  
Laura Viñas-Giménez ◽  
Rafael Rincón ◽  
Roger Colobran ◽  
Xavier de la Cruz ◽  
Verónica Paola Celis ◽  
...  

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory disorder. HLH can be considered as a threshold disease depending on the trigger and the residual NK-cell cytotoxicity. In this study, we analyzed the molecular and functional impact of a novel monoallelic mutation found in a patient with two episodes of HLH. A 9-month-old child was diagnosed at 2 months of age with cutaneous Langerhans cell histiocytosis (LCH). After successful treatment, the patient developed an HLH episode. At 16 month of age, the patient went through an HSCT losing the engraftment 5 months later concomitant with an HLH relapse. The genetic study revealed a monoallelic mutation in the STXBP2 gene (.pArg190Cys). We transfected COS7 cells to analyze the STXBP2-R190C expression and to test the interaction with STX11. We used the RBL-2H3 cell line expressing STXBP2-WT-EGFP or R190C-EGFP for degranulation assays. Mutation STXBP2-R190C did not affect protein expression or interaction with syntaxin-11. However, we have demonstrated that STXBP2-R190C mutation diminishes degranulation in the RBL-2H3 cell line compared with the RBL-2H3 cell line transfected with STXBP2-WT or nontransfected. These results suggest that STXBP2-R190C mutation acts as a modifier of the degranulation process producing a decrease in degranulation. Therefore, under homeostatic conditions, the presence of one copy of STXBP2-R190 could generate sufficient degranulation capacity. However, it is likely that early in life when adaptive immune system functions are not sufficiently developed, an infection may not be resolved with this genetic background, leading to a hyperinflammation syndrome and eventually develop HLH. This analysis highlights the need for functional testing of new mutations to validate their role in genetic susceptibility and to establish the best possible treatment for these patients.


Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2458
Author(s):  
Anna Makowska ◽  
Nora Lelabi ◽  
Christina Nothbaum ◽  
Lian Shen ◽  
Pierre Busson ◽  
...  

Background: Nasopharyngeal carcinoma (NPC) in endemic regions and younger patients is characterized by a prominent lymphomononuclear infiltration. Radiation is the principal therapeutic modality for patients with NPC. Recent data suggest that the efficacy of radiotherapy in various cancers can be augmented when combined with immune checkpoint blockade. Here, we investigate the effect of radiotherapy on the killing of NPC cells by Natural Killer (NK) cells. Methods: NPC cell lines and a patient-derived xenograft were exposed to NK cells in the context of radiotherapy. Cytotoxicity was measured using the calcein-release assay. The contribution of the PD-L1/PD-1 checkpoint and signaling pathways to killing were analyzed using specific inhibitors. Results: Radiotherapy sensitized NPC cells to NK cell killing and upregulated expression of PD-1 ligand (PD-L1) in NPC cells and PD-1 receptor (PD-1) in NK cells. Blocking of the PD-L1/PD-1 checkpoint further increased the killing of NPC cells by NK cells in the context of radiotherapy. Conclusion: Radiation boosts the killing of NPC cells by NK cells. Killing can be further augmented by blockade of the PD-L1/PD-1 checkpoint. The combination of radiotherapy with PD-L1/PD-1 checkpoint blockade could therefore increase the efficacy of radiotherapy in NPC tumors.


2021 ◽  
Vol 21 (6) ◽  
Author(s):  
Guo Zhou ◽  
Jiaxin Bei ◽  
Tianyang Li ◽  
Kangshun Zhu ◽  
Zhengkun Tu

Background: Activation of hepatic stellate cells (HSCs) is an important driver of liver fibrosis, which is a health problem of global concern, and there is no effective solution for it at the present. Senescent activated HSCs are preferentially killed by natural killer cells (NK cells) to promote the regression of hepatic fibrosis. Objectives: The purpose of this study was to investigate the effect of polyinosinic-polycytidylic acid (poly I:C) on HSCs’ senescence, a trigger for NK cell-induced cytotoxicity. Methods: The senescence of HSCs was assessed by western blot, qRT-PCR, and flow cytometry, and NK cell cytotoxicity was assessed in a co-culture of NK cells with poly I:C-treated HSCs by measuring CD107a expression. Results: The expression of p16, p21, SA-β-gal, MICA/MICB, and ULBP2 increased in poly I:C-treated HSCs, rendering them significantly susceptible to NK cell cytotoxicity. Conclusions: Poly I:C induces cellular senescence in HSCs and triggers NK cell immunosurveillance, suggesting that the role of poly I:C in HSC senescence may promote fibrosis regression.


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