scholarly journals Intrinsic Resistance of Chronic Lymphocytic Leukemia Cells to NK Cell-Mediated Lysis Can Be Overcome In Vitro by Pharmacological Inhibition of Cdc42-Induced Actin Cytoskeleton Remodeling

2021 ◽  
Vol 12 ◽  
Author(s):  
Hannah Wurzer ◽  
Liza Filali ◽  
Céline Hoffmann ◽  
Max Krecke ◽  
Andrea Michela Biolato ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Actin Cytoskeleton ◽  
Nk Cells ◽  
Nk Cell ◽  
Granzyme B ◽  
Lymphocytic Leukemia ◽  
Cell Cytotoxicity ◽  
Cytoskeleton Remodeling ◽  
Nk Cell Cytotoxicity

Natural killer (NK) cells are innate effector lymphocytes with strong antitumor effects against hematologic malignancies such as chronic lymphocytic leukemia (CLL). However, NK cells fail to control CLL progression on the long term. For effective lysis of their targets, NK cells use a specific cell-cell interface, known as the immunological synapse (IS), whose assembly and effector function critically rely on dynamic cytoskeletal changes in NK cells. Here we explored the role of CLL cell actin cytoskeleton during NK cell attack. We found that CLL cells can undergo fast actin cytoskeleton remodeling which is characterized by a NK cell contact-induced accumulation of actin filaments at the IS. Such polarization of the actin cytoskeleton was strongly associated with resistance against NK cell-mediated cytotoxicity and reduced amounts of the cell-death inducing molecule granzyme B in target CLL cells. Selective pharmacological targeting of the key actin regulator Cdc42 abrogated the capacity of CLL cells to reorganize their actin cytoskeleton during NK cell attack, increased levels of transferred granzyme B and restored CLL cell susceptibility to NK cell cytotoxicity. This resistance mechanism was confirmed in primary CLL cells from patients. In addition, pharmacological inhibition of actin dynamics in combination with blocking antibodies increased conjugation frequency and improved CLL cell elimination by NK cells. Together our results highlight the critical role of CLL cell actin cytoskeleton in driving resistance against NK cell cytotoxicity and provide new potential therapeutic point of intervention to target CLL immune escape.

scholarly journals α-Pinene Enhances the Anticancer Activity of Natural Killer Cells via ERK/AKT Pathway

2021 ◽  
Vol 22 (2) ◽  
pp. 656
Author(s):  
Hantae Jo ◽  
Byungsun Cha ◽  
Haneul Kim ◽  
Sofia Brito ◽  
Byeong Mun Kwak ◽  
...  
Keyword(s):  
Nk Cells ◽  
Cancer Cells ◽  
Natural Killer ◽  
Nk Cell ◽  
Granzyme B ◽  
Akt Pathway ◽  
Cell Cytotoxicity ◽  
Anticancer Effects ◽  
Nk Cell Cytotoxicity

Natural killer (NK) cells are lymphocytes that can directly destroy cancer cells. When NK cells are activated, CD56 and CD107a markers are able to recognize cancer cells and release perforin and granzyme B proteins that induce apoptosis in the targeted cells. In this study, we focused on the role of phytoncides in activating NK cells and promoting anticancer effects. We tested the effects of several phytoncide compounds on NK-92mi cells and demonstrated that α-pinene treatment exhibited higher anticancer effects, as observed by the increased levels of perforin, granzyme B, CD56 and CD107a. Furthermore, α-pinene treatment in NK-92mi cells increased NK cell cytotoxicity in two different cell lines, and immunoblot assays revealed that the ERK/AKT pathway is involved in NK cell cytotoxicity in response to phytoncides. Furthermore, CT-26 colon cancer cells were allografted subcutaneously into BALB/c mice, and α-pinene treatment then inhibited allografted tumor growth. Our findings demonstrate that α-pinene activates NK cells and increases NK cell cytotoxicity, suggesting it is a potential compound for cancer immunotherapy.

PRESENCE OF FcR FOR IgG AND IgM ON HUMAN NK CELLS: THE ROLE OF IMMUNE COMPLEXES IN THE REGULATION OF NK CELL CYTOTOXICITY

1982 ◽  
pp. 631-637 ◽  
Author(s):  
Jean E. Merrill ◽  
Sidney Golub ◽  
Mikael Jondal ◽  
Fred Lanefeldt ◽  
Bertil Fredholm
Keyword(s):  
Nk Cells ◽  
Immune Complexes ◽  
Nk Cell ◽  
Cell Cytotoxicity ◽  
Nk Cell Cytotoxicity

scholarly journals The PP2A inhibitor SET regulates granzyme B expression in human natural killer cells

Blood ◽  
2011 ◽  
Vol 117 (8) ◽  
pp. 2378-2384 ◽  
Author(s):  
Rossana Trotta ◽  
David Ciarlariello ◽  
Jessica Dal Col ◽  
Hsiaoyin Mao ◽  
Li Chen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Nk Cells ◽  
Natural Killer ◽  
Nk Cell ◽  
Granzyme B ◽  
Interleukin 2 ◽  
Mrna Levels ◽  
Cell Cytotoxicity ◽  
Nk Cell Cytotoxicity ◽  
Pp2a Inhibitor

Abstract The ability of natural killer (NK) cells to kill malignant or infected cells depends on the integration of signals from different families of cell surface receptors, including cytokine receptors. How such signals then regulate NK-cell cytotoxicity is incompletely understood. Here we analyzed an endogenous inhibitor of protein phosphatase 2A (PP2A) activity called SET, and its role in regulating human NK-cell cytotoxicity and its mechanism of action in human NK cells. RNAi-mediated suppression of SET down-modulates NK-cell cytotoxicity, whereas ectopic overexpression of SET enhances cytotoxicity. SET knockdown inhibits both mRNA and protein granzyme B expression, as well as perforin expression, whereas SET overexpression enhances granzyme B expression. Treatment of NK cells with the PP2A activator 1,9-dideoxy-forskolin also inhibits both granzyme B expression and cytotoxicity. In addition, pretreatment with the PP2A inhibitor okadaic acid rescues declining granzyme B mRNA levels in SET knockdown cells. Down-modulation of SET expression or activation of PP2A also decreases human NK-cell antibody-dependent cellular cytotoxicity. Finally, the induction of granzyme B gene expression by interleukin-2 and interleukin-15 is inhibited by SET knockdown. These data provide evidence that granzyme B gene expression and therefore human NK-cell cytotoxicity can be regulated by the PP2A-SET interplay.

Impaired NK cell cytotoxicity by high level of interferon-γ in concanavalin A-induced hepatitis

2005 ◽  
Vol 83 (11) ◽  
pp. 1045-1053 ◽  
Author(s):  
Zhongjun Dong ◽  
Cai Zhang ◽  
Haiming Wei ◽  
Rui Sun ◽  
Zhigang Tian
Keyword(s):  
Nk Cells ◽  
Cell Lines ◽  
Nk Cell ◽  
Interferon Γ ◽  
Cell Cytotoxicity ◽  
Wild Mice ◽  
Ifn Γ ◽  
Nk Cell Cytotoxicity

Unlike T cells, the role of natural killer (NK) cells is not well documented in the concanavalin (ConA)- induced hepatitis model. This study aimed to investigate the regulatory effect of high levels of interferon-γ (IFN-γ) on NK cells in ConA-induced hepatitis. The cytotoxicities of NK cells from ConA-injected mice or NK cell lines (NK92 and NKL) were detected by the 4-h 51Cr release assay. Depletion of NK cells with AsGM1 antibody was used to assess the NK cell role in ConA-induced hepatitis. Expression of NK cell receptors and cytotoxic molecules was measured by reverse transcription – polymerase chain reaction. Twelve hours after ConA injection, serum IFN-γ was significantly increased in wild mice, but not in severe combined immunodeficiency mice, and hepatic NK cells exerted impaired cytotoxicity against YAC-l cells in wild mice. Eight hours after NK cells were incubated in serum from ConA-treated mice, NK cell cytotoxicity was down-modulated and the effect was abolished by pretreatment with neutralizing serum IFN-γ with specific antibody in vitro. A high concentration of IFN-γ (> 1000 U/mL) inhibited the cytotoxicities of 2 NK cell lines in vitro, accompanied with down-regulation of NKG2D transcripts and up-regulation of NKG2A/B and KIR2DL transcripts. The inhibitive role of IFN-γ was not seen in NKG2D ligand negative cells. These results suggest that NK cell cytotoxicity was inhibited by high levels of IFN-γ in ConA-induced hepatitis, which may relate to the dispensable role of NK cells.Key words: cytotoxicity, hepatoimmunology, interferon-γ, liver injury.

scholarly journals MicroRNA-20a mediates the cytotoxicity of natural killer cells in endometriosis via ERG/HLX/STAT4/perforin axis

2019 ◽  
Author(s):  
Li-Juan Chen ◽  
Bin Hu ◽  
Zhi-Qiang Han ◽  
Jian Ni ◽  
Yong-Ming Zhou ◽  
...  
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Nude Mice ◽  
Nk Cell ◽  
Protective Role ◽  
Cell Cytotoxicity ◽  
Nk Cell Cytotoxicity

Abstract Background: Intriguingly, microRNA-20a (miR-20a) has been recently witnessed to be involved in the pathogenesis of endometriosis (EMS) but the molecular mechanism controlled by miR-20a is to be undefined. The present study is designed to probe into how miR-20a acts to regulate the cytotoxicity of natural killer (NK) cells. Methods: Most of all, consistent with the clinical determination in EMS patients, miR-20a was determined to be down-regulated in NK cells isolated from nude mice. miR-20a could specifically bind to ERG and negatively regulates its expression in NK cells. Additionally, shRNA-mediated silencing of ERG decreased the expression of HLX. HLX up-regulated STAT4 by inducing proteasome degradation and inhibited NK cell cytotoxicity. Results: Of great importance, forced expression of miR-20a consequently induced NK cell cytotoxicity in vitro by increasing perforin expression via enhancement of STAT4 that was caused by impairing the binding of ERG to HLX enhancer. The in vivo experiments further confirmed the promoting role of miR-20a in the cytotoxicity of NK cells isolated from EMS nude mice and subsequent protective role of miR-20a against EMS-induced endometrial injury. Conclusion: The aforementioned data suggest that miR-20a potentiates the cytotoxicity of NK via up-regulating perforin mediated by ERG/HLX/STAT4, highlighting potential novel mechanisms associated with EMS progression.

Differential Effects of the BCR-ABL-Inhibitors Imatinib, Nilotinib and Dasatinib on NK Cell Reactivity against Chronic Myeloid Leukemia (CML)

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3200-3200
Author(s):  
Matthias Krusch ◽  
Julia Salih ◽  
Lothar Kanz ◽  
Helmut R Salih
Keyword(s):  
Nk Cells ◽  
Nk Cell ◽  
Minor Effect ◽  
Cell Cytotoxicity ◽  
Cell Reactivity ◽  
Erk Phosphorylation ◽  
Ifn Γ ◽  
Nk Cell Cytotoxicity ◽  
A Minor

Abstract CML is characterized by the BCR-ABL fusion protein, which mediates the oncogenic signaling. This led to the development of BCR-ABL inhibitors revolutionizing therapy of CML. However, as recently reported for Dasatinib (Schade et al., Blood 111:1366 (2008); Blake et al., Blood 111:4415 (2008)), these agents may impair the activity of immune effector cells like NK cells and T cells. After initiating oncogenic events, development and progression of clinically apparent malignancy is dependent on the evasion of the tumor cells from immunosurveillance. In light of the important role of NK cell reactivity against leukemia we compared the influence of Imatinib, Nilotinib and Dasatinib on the reactivity of both resting and IL-2 activated NK cells against CML cells to identify the compound with the least immuno-compromising side effects. First, the effects of the compounds on NK cell reactivity in concentrations corresponding to plasma peak levels were studied. Dasatinib (200nM) completely abolished NK cell granule mobilization, cytotoxicity and IFN-γ production, while no substantial inhibition was observed with Imatinib (5μM) and Nilotinib (3.6μM) mediated a minor but significant inhibition (p<0.05, Student’s T-test). Presence of the compounds in concentrations corresponding to IC50 levels (Imatinib 600nM, Nilotinib 30nM, Dasatinib 10nM) revealed no influence of Imatinib and Nilotinib, while Dasatinib still significantly reduced NK cell cytotoxicity and IFN-γ production up to 60%. Since Dasatinib, in addition to BCR-ABL, potently inhibits SRC kinases, which are involved in the activation of MAPK pathways and thus crucial for NK cell cytotoxicity, we determined the influence of the compounds on ERK phosphorylation. While no inhibitory effect was observed using Imatinib and Nilotinib, Dasatinib markedly reduced ERK phosphorylation in NK cells. Our data demonstrate that NK cell anti-tumor reactivity is not inhibited by clinically relevant concentrations of Imatinib. While Nilotinib may mediate a minor effect, Dasatinib substantially impairs NK cell reactivity by inhibition of signaling pathways crucial for NK cell effector functions. For a given patient, the choice and dosing of the most suitable BCR-ABL inhibitor may thus require careful consideration of its influence on the immune system, especially in view of the important role of NK cells in the immunesurveillance of residual leukemia.

scholarly journals BTLA/HVEM Axis Induces NK Cell Immunosuppression and Poor Outcome in Chronic Lymphocytic Leukemia

Cancers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1766
Author(s):  
Christian Sordo-Bahamonde ◽  
Seila Lorenzo-Herrero ◽  
Ana P Gonzalez-Rodriguez ◽  
Ángel R. Payer ◽  
Esther González-García ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Nk Cells ◽  
Nk Cell ◽  
Ex Vivo ◽  
In Silico Analysis ◽  
Immune Checkpoint Blockade ◽  
Lymphocytic Leukemia ◽  
Leukemic Cells ◽  
Poor Outcome

Chronic lymphocytic leukemia (CLL) is characterized by progressive immunosuppression and diminished cancer immunosurveillance. Immune checkpoint blockade (ICB)-based therapies, a major breakthrough against cancer, have emerged as a powerful tool to reinvigorate antitumor responses. Herein, we analyzed the role of the novel inhibitory checkpoint BTLA and its ligand, HVEM, in the regulation of leukemic and natural killer (NK) cells in CLL. Flow cytometry analyses showed that BTLA expression is upregulated on leukemic cells and NK cells from patients with CLL, whereas HVEM is downregulated only in leukemic cells, especially in patients with advanced Rai-Binet stage. In silico analysis revealed that increased HVEM, but not BTLA, mRNA expression in leukemic cells correlated with diminished overall survival. Further, soluble BTLA (sBTLA) was found to be increased in the sera of patients with CLL and highly correlated with poor prognostic markers and shorter time to treatment. BTLA blockade with an anti-BTLA monoclonal antibody depleted leukemic cells and boosted NK cell-mediated responses ex vivo by increasing their IFN-γ production, cytotoxic capability, and antibody-dependent cytotoxicity (ADCC). In agreement with an inhibitory role of BTLA in NK cells, surface BTLA expression on NK cells was associated with poor outcome in patients with CLL. Overall, this study is the first to bring to light a role of BTLA/HVEM in the suppression of NK cell-mediated immune responses in CLL and its impact on patient’s prognosis, suggesting that BTLA/HVEM axis may be a potential therapeutic target in this disease.

scholarly journals LncRNA GAS5 enhanced the killing effect of NK cell on liver cancer through regulating miR-544/RUNX3

2019 ◽  
Vol 25 (2) ◽  
pp. 99-109 ◽  
Author(s):  
Peipei Fang ◽  
Luxia Xiang ◽  
Weilai Chen ◽  
Shaoxun Li ◽  
Shanshan Huang ◽  
...  
Keyword(s):  
Liver Cancer ◽  
Nk Cells ◽  
Nk Cell ◽  
Cell Cytotoxicity ◽  
Killing Effect ◽  
Apoptosis Rate ◽  
Ifn Γ ◽  
Nk Cell Cytotoxicity ◽  
Lncrna Gas5

This study aimed to explore the role of lncRNA GAS5 in the regulation of the killing effect of NK cells on liver cancer. Compared with a control group, lncRNA GAS5, RUNX3, and NCR1 were down-regulated in NK cells of patients with liver cancer, whereas miR-544 expression was up-regulated in NK cells of patients with liver cancer. Activated NK cells had higher IFN-γ level. Knockdown of GAS5 in activated NK cells decreased IFN-γ secretion, NK cell cytotoxicity, the percentage of CD107a+ NK cells, and the apoptosis rate of HepG2 and Huh7 cells. We also proved the interaction of GAS5 and miR-544, and the negative regulation role of GAS5 on miR-544. GAS5 overexpression in activated NK cells increased RUNX3 expression, IFN-γ secretion, the NK cell cytotoxicity, the percentage of CD107a+ NK cells, and the apoptosis rate of HepG2 cells, while miR-544 mimic abolished the promotion effect of GAS5 overexpression. Finally, in vivo experiments indicated an inhibition effect of GAS5 in tumor growth. LncRNA GAS5 overexpression enhances the killing effect of NK cell on liver cancer through regulating miR-544/RUNX3.

scholarly journals NK Cells in Chronic Lymphocytic Leukemia and Their Therapeutic Implications

2021 ◽  
Vol 22 (13) ◽  
pp. 6665
Author(s):  
Paolo Sportoletti ◽  
Filomena De Falco ◽  
Beatrice Del Papa ◽  
Stefano Baldoni ◽  
Valerio Guarente ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Nk Cells ◽  
Nk Cell ◽  
Current Knowledge ◽  
Therapeutic Option ◽  
Large Body ◽  
Lymphocytic Leukemia ◽  
Leukemic Cells ◽  
Cell Functions

Key features of chronic lymphocytic leukemia (CLL) are defects in the immune system and the ability of leukemic cells to evade immune defenses and induce immunosuppression, resulting in increased susceptibility to infections and disease progression. Several immune effectors are impaired in CLL, including T and natural killer (NK) cells. The role of T cells in defense against CLL and in CLL progression and immunotherapy has been extensively studied. Less is known about the role of NK cells in this leukemia, and data on NK cell alterations in CLL are contrasting. Besides studies showing that NK cells have intrinsic defects in CLL, there is a large body of evidence indicating that NK cell dysfunctions in CLL mainly depend on the escape mechanisms employed by leukemic cells. In keeping, it has been shown that NK cell functions, including antibody-dependent cellular cytotoxicity (ADCC), can be retained and/or restored after adequate stimulation. Therefore, due to their preserved ADCC function and the reversibility of CLL-related dysfunctions, NK cells are an attractive source for novel immunotherapeutic strategies in this disease, including chimeric antigen receptor (CAR) therapy. Recently, satisfying clinical responses have been obtained in CLL patients using cord blood-derived CAR-NK cells, opening new possibilities for further exploring NK cells in the immunotherapy of CLL. However, notwithstanding the promising results of this clinical trial, more evidence is needed to fully understand whether and in which CLL cases NK cell-based immunotherapy may represent a valid, alternative/additional therapeutic option for this leukemia. In this review, we provide an overview of the current knowledge about phenotypic and functional alterations of NK cells in CLL and the mechanisms by which CLL cells circumvent NK cell-mediated immunosurveillance. Additionally, we discuss the potential relevance of using NK cells in CLL immunotherapy.

scholarly journals The effect of IL-2 stimulation and treatment of TRPM3 on channel co-localisation with PIP2 and NK cell function in myalgic encephalomyelitis/chronic fatigue syndrome patients

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Natalie Eaton-Fitch ◽  
Hélène Cabanas ◽  
Stanley du Preez ◽  
Donald Staines ◽  
Sonya Marshall-Gradisnik
Keyword(s):  
Chronic Fatigue Syndrome ◽  
Nk Cells ◽  
Cell Function ◽  
Nk Cell ◽  
Chronic Fatigue ◽  
Signalling Pathways ◽  
Cell Cytotoxicity ◽  
Fatigue Syndrome ◽  
Intracellular Signalling Pathways ◽  
Nk Cell Cytotoxicity

Abstract Background Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a serious multifactorial disorder. The origin remains ambiguous, however reduced natural killer (NK) cell cytotoxicity is a consistent immunological feature of ME/CFS. Impaired transient receptor potential melastatin 3 (TRPM3), a phosphatidylinositol dependent channel, and impaired calcium mobilisation have been implicated in ME/CFS pathology. This investigation aimed to examine the localisation of TRPM3 at the NK cell plasma membrane and co-localisation with phosphatidylinositol 4,5-bisphosphate (PIP2). The effect of IL-2 priming and treatment using pregnenolone sulfate (PregS) and ononetin on TRPM3 co-localisation and NK cell cytotoxicity in ME/CFS patients and healthy controls (HC) was also investigated. Methods NK cells were isolated from 15 ME/CFS patients and 15 age- and sex-matched HC. Immunofluorescent technique was used to determine co-localisation of TRPM3 with the NK cell membrane and with PIP2 of ME/CFS patients and HC. Flow cytometry was used to determine NK cell cytotoxicity. Following IL-2 stimulation and treatment with PregS and ononetin changes in co-localisation and NK cell cytotoxicity were measured. Results Overnight treatment of NK cells with PregS and ononetin resulted in reduced co-localisation of TRPM3 with PIP2 and actin in HC. Co-localisation of TRPM3 with PIP2 in NK cells was significantly reduced in ME/CFS patients compared with HC following priming with IL-2. A significant increase in co-localisation of TRPM3 with PIP2 was reported following overnight treatment with ononetin within ME/CFS patients and between groups. Baseline NK cell cytotoxicity was significantly reduced in ME/CFS patients; however, no changes were observed following overnight incubation with IL-2, PregS and ononetin between HC and ME/CFS patients. IL-2 stimulation significantly enhanced NK cell cytotoxicity in HC and ME/CFS patients. Conclusion Significant changes in co-localisation suggest PIP2-dependent TRPM3 function may be impaired in ME/CFS patients. Stimulation of NK cells with IL-2 significantly enhanced cytotoxic function in ME/CFS patients demonstrating normal function compared with HC. A crosstalk exists between IL-2 and TRPM3 intracellular signalling pathways which are dependent on Ca2+ influx and PIP2. While IL-2R responds to IL-2 binding in vitro, Ca2+ dysregulation and impaired intracellular signalling pathways impede NK cell function in ME/CFS patients.

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