scholarly journals CD56 regulates human NK cell cytotoxicity through Pyk2

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Justin T Gunesch ◽  
Amera L Dixon ◽  
Tasneem AM Ebrahim ◽  
Melissa M Berrien-Elliott ◽  
Swetha Tatineni ◽  
...  
Keyword(s):  
Nk Cells ◽  
Immune Cells ◽  
Immunological Synapse ◽  
Nk Cell ◽  
Functional Link ◽  
Lytic Granules ◽  
Nk Cell Cytotoxicity ◽  
Lytic Granule ◽  
Cytotoxic Function

Human natural killer (NK) cells are defined as CD56+CD3−. Despite its ubiquitous expression on human NK cells the role of CD56 (NCAM) in human NK cell cytotoxic function has not been defined. In non-immune cells, NCAM can induce signaling, mediate adhesion, and promote exocytosis through interactions with focal adhesion kinase (FAK). Here we demonstrate that deletion of CD56 on the NK92 cell line leads to impaired cytotoxic function. CD56-knockout (KO) cells fail to polarize during immunological synapse (IS) formation and have severely impaired exocytosis of lytic granules. Phosphorylation of the FAK family member Pyk2 at tyrosine 402 is decreased in NK92 CD56-KO cells, demonstrating a functional link between CD56 and signaling in human NK cells. Cytotoxicity, lytic granule exocytosis, and the phosphorylation of Pyk2 are rescued by the reintroduction of CD56. These data highlight a novel functional role for CD56 in stimulating exocytosis and promoting cytotoxicity in human NK cells.

scholarly journals CD56 regulates human NK cell cytotoxicity through Pyk2

2020 ◽  
Author(s):  
Justin T. Gunesch ◽  
Amera L. Dixon ◽  
Tasneem Ebrahim ◽  
Melissa Berrien-Elliott ◽  
Swetha Tatineni ◽  
...  
Keyword(s):  
Nk Cells ◽  
Cell Line ◽  
Cell Lines ◽  
Target Cell ◽  
Immune Cells ◽  
Nk Cell ◽  
Cell Lysis ◽  
Cytokine Secretion ◽  
Functional Link ◽  
Cytotoxic Function

Natural killer (NK) cells are innate immune cells that control viral infection and tumorigenic cell growth through targeted cell lysis and cytokine secretion. Human NK cells are classically defined as CD56+CD3− in peripheral blood. CD56 is neural cell adhesion molecule (NCAM1), and despite its ubiquitous expression on human NK cells, the role of CD56 in human NK cell cytotoxic function has not been fully explored. In non-immune cells, NCAM can induce signaling, mediate adhesion, and promote exocytosis, in part through interactions with focal adhesion kinase (FAK). Here we describe the generation and use of CD56-deficient human NK cell lines to define a novel requirement for CD56 in target cell lysis. Namely, we demonstrate that deletion of CD56 on the NK92 cell line led to impaired cytotoxic function against multiple susceptible target cell lines. Deletion of CD56 in a second NK cell line, YTS cells, led to a less severe cytotoxicity defect but impairment in cytokine secretion. Confocal microscopy of wild-type and CD56-KO NK92 cells conjugated to susceptible targets revealed that CD56-KO cells failed to polarize during immunological synapse (IS) formation and had severely impaired exocytosis of lytic granules at the IS. Phosphorylation of the FAK family member Pyk2 at tyrosine 402 was decreased in NK92 CD56-KO cells, demonstrating a functional link between CD56 and IS formation and signaling in human NK cells. Cytotoxicity, lytic granule exocytosis, and the phosphorylation of Pyk2 were rescued by the reintroduction of NCAM140 (CD56), into NK92 CD56-KO cells. These data highlight a novel functional role for CD56 in stimulating exocytosis and promoting cytotoxicity in human NK cells.

scholarly journals Microfluidic tumor-on-a-chip model to evaluate the role of tumor environmental stress on NK cell exhaustion

2021 ◽  
Vol 7 (8) ◽  
pp. eabc2331 ◽  
Author(s):  
Jose M. Ayuso ◽  
Shujah Rehman ◽  
Maria Virumbrales-Munoz ◽  
Patrick H. McMinn ◽  
Peter Geiger ◽  
...  
Keyword(s):  
Nk Cells ◽  
Immune Cells ◽  
Molecular Mechanisms ◽  
Nk Cell ◽  
Checkpoint Inhibitors ◽  
Waste Product ◽  
Extended Period ◽  
Cell Exhaustion

Solid tumors generate a suppressive environment that imposes an overwhelming burden on the immune system. Nutrient depletion, waste product accumulation, hypoxia, and pH acidification severely compromise the capacity of effector immune cells such as T and natural killer (NK) cells to destroy cancer cells. However, the specific molecular mechanisms driving immune suppression, as well as the capacity of immune cells to adapt to the suppressive environment, are not completely understood. Thus, here, we used an in vitro microfluidic tumor-on-a-chip platform to evaluate how NK cells respond to the tumor-induced suppressive environment. The results demonstrated that the suppressive environment created by the tumor gradually eroded NK cell cytotoxic capacity, leading to compromised NK cell surveillance and tumor tolerance. Further, NK cell exhaustion persisted for an extended period of time after removing NK cells from the microfluidic platform. Last, the addition of checkpoint inhibitors and immunomodulatory agents alleviated NK cell exhaustion.

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.

scholarly journals Nonstochastic Coexpression of Activation Receptors on Murine Natural Killer Cells

2000 ◽  
Vol 191 (8) ◽  
pp. 1341-1354 ◽  
Author(s):  
Hamish R.C. Smith ◽  
Hubert H. Chuang ◽  
Lawrence L. Wang ◽  
Margarita Salcedo ◽  
Jonathan W. Heusel ◽  
...  
Keyword(s):  
Natural Killer Cells ◽  
Nk Cells ◽  
Natural Killer ◽  
Nk Cell ◽  
Inhibitory Receptors ◽  
Antigen Receptors ◽  
Killer Cells ◽  
Histocompatibility Complex ◽  
Nk Cell Cytotoxicity

Murine natural killer cells (NK) express lectin-like activation and inhibitory receptors, including the CD94/NKG2 family of receptors that bind Qa-1, and the Ly-49 family that recognizes major histocompatibility complex class I molecules. Here, we demonstrate that cross-linking of NK cells with a new specific anti–Ly-49H mAb induced NK cell cytotoxicity and cytokine production. Ly-49H is expressed on a subset of NK cells and can be coexpressed with Ly-49 inhibitory receptors. However, unlike Ly-49 inhibitory receptors, Ly-49H is not detectable on naive splenic CD3+ T cells, indicating that Ly-49H may be an NK cell–specific activation receptor. In further contrast to the stochastically expressed Ly-49 inhibitory receptors, Ly-49H is preferentially expressed with the Ly-49D activation receptor, and expression of both Ly-49H and Ly-49D is augmented on NK cells that lack receptors for Qa-1 tetramers. On developing splenic NK1.1+ cells, Ly-49D and Ly-49H are expressed later than the inhibitory receptors. These results directly demonstrate that Ly-49H activates primary NK cells, and suggest that expression of Ly-49 activation receptors by NK cells may be specifically regulated on NK cell subsets. The simultaneous expression of multiple activation receptors by individual NK cells contrasts with that of T cell antigen receptors and is relevant to the role of NK cells in innate immunity.

The Role of Interleukin-15 on Natural Killer Cell Homeostasis and Activity in Patients with Acute Myeloid Leukemia

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2574-2574
Author(s):  
Mi roslaw J Szczepanski ◽  
Malgorzata Czystowska ◽  
Marta E Szajnik ◽  
Magis Mandapathil ◽  
Benedict Hilldorfer ◽  
...  
Keyword(s):  
Nk Cells ◽  
Myeloid Leukemia ◽  
Nk Cell ◽  
Intensive Chemotherapy ◽  
Interleukin 15 ◽  
The Mean ◽  
Nk Cell Cytotoxicity ◽  
Anti Tumor Activity ◽  
Acute Myeloid

Abstract Interleukin-15 (IL-15) has been demonstrated to play a critical role in the regulation of natural killer (NK) cells. IL-15 induces the differentiation of NK cells from hematopoietic progenitors, stimulates the expansion of peripheral NK cells, and supports their survival. We investigated the role of IL-15 as a homeostatic regulator of NK cells in 29 patients diagnosed with acute myeloid leukemia (AML) and the potential role of IL-15 in enhancing the anti-tumor activity of NK cells in AML patients. The percentage of circulating NK cells was lower (p<0.0001) in the AML patients (6%± 0.7, range 1–17%) compared to the NK cells of healthy donors (12%± 1, range 9–17 %). At diagnosis the mean level of IL-15 in patient plasma was 1.9 pg/ml (range 0.03–8.9) and increased (p <0.02) to 5.2 pg/ml (range 0.06–13.4) after the completion of induction chemotherapy, when the NK levels had been reduced to zero cells/microliter. The mean level of IL-15 subsequently decreased to pre-treatment levels in the AML patients who achieved complete remission (mean 1.6 pg/ml, range 0.4–2.3). To assess effects of IL-15 on the NK cytotoxicity, we sorted NK cells from PBMC obtained from AML patients prior to treatment (at diagnosis) and cultured them in the presence of IL-15. Following IL-15 stimulation, a significant increase in NK-cell cytotoxicity against K562 targets and the patients’ autologous leukemic blasts was observed (p<0.05) as was up-regulation in expression of the activating natural cytotoxicity receptors, NKp30 and NKp46 and the C-type lectin receptors NKG2D and NKG2C (p<0.02–0.001). Addition of blocking antibodies to the activating receptors reduced NK-cell cytotoxicity. We determined that IL-15, a homeostatic NK-cell cytokine, increases after severe depletion of NK cells following intensive chemotherapy and this leads to increased NK-cell lytic activity in AML patients. These data suggest that modulation of IL-15 levels in AML could be therapeutically beneficial as IL-15 enhances NK-cell recovery following intensive chemotherapy and increases NK-cell anti-tumor activity.

Magnesium alterations of graft immune cells (MAGIC).

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e18541-e18541
Author(s):  
Ramy Sedhom ◽  
Andrew Zloza ◽  
Frederick Joseph Kohlhapp ◽  
Daniel Medina ◽  
Roger Strair
Keyword(s):  
Monoclonal Antibodies ◽  
Nk Cells ◽  
Immune Cells ◽  
Nk Cell ◽  
Jurkat Cells ◽  
Nk Activity ◽  
Functional Link ◽  
Hematopoietic Stem ◽  
Post Transplant ◽  
Nkg2d Expression

e18541 Background: Magnesium plays important roles in cellular processes. Allogeneic hematopoietic stem cell transplantation provides potentially curative therapy to patients with a variety of hematologic malignancies. A common abnormality post transplant is hypomagnesaemia. Recent studies identified magnesium transporter 1 deficiency in association with XMEN syndrome. These patients exhibit low intracellular [Mg++] and low T cell and NK cell NKG2D expression. Therefore, we investigated this potential functional link between magnesium deficiency and immune function in patients post transplant. Methods: A pilot study investigated whether detectable changes in T and NK cells were associated with IV magnesium repletion post hematopoietic transplant. Blood was obtained before and after magnesium transfusions. Immunophenotypic analysis of T and NK cell NKG2D levels using commercially available monoclonal antibodies (CD3, CD16, CD56, CD4, CD8, CD314 [NKG2D]) was performed. Samples from patients demonstrating an increase in NKG2D expression were subsequently analyzed for ex vivo NK activity. Here, NK activity and cytotoxicity of Jurkat cells were assayed using standard laboratory techniques and changes > 2 fold were considered significant. A total of 7 patients were enrolled. Results: NKG2D expression on T and NK cell subsets were determined by flow cytometry using commercially available monoclonal antibodies. NK reactivity and killing of K562 were undertaken using standard cytotoxicity assays. Our findings indicate a significant response in five of the seven enrolled patients. NKG2D expression on CD8+ T cells increased by up to 31%. Conclusions: Our results suggest that magnesium infusions post allogeneic transplant are associated with augmented NKG2D expression on immune cells. Additional studies are needed to clarify the mechanisms by which therapeutic magnesium repletion restores the cytotoxicity of NK cells and T lymphocytes. Although the clinical utility of magnesium supplementation remains to be validated, our data indicate that NKG2D is regulated by magnesium post transplant and magnesium may play a key role in immune regulation.

scholarly journals Degranulation enhances presynaptic membrane packing, which protects NK cells from perforin-mediated autolysis

PLoS Biology ◽  
2021 ◽  
Vol 19 (8) ◽  
pp. e3001328
Author(s):  
Yu Li ◽  
Jordan S. Orange
Keyword(s):  
Nk Cells ◽  
Target Cell ◽  
Lipid Membranes ◽  
Cell Membranes ◽  
Nk Cell ◽  
Cancer Cell Line ◽  
Membrane Properties ◽  
Presynaptic Membrane ◽  
Lytic Granules ◽  
Lytic Granule

Natural killer (NK) cells kill a target cell by secreting perforin into the lytic immunological synapse, a specialized interface formed between the NK cell and its target. Perforin creates pores in target cell membranes allowing delivery of proapoptotic enzymes. Despite the fact that secreted perforin is in close range to both the NK and target cell membranes, the NK cell typically survives while the target cell does not. How NK cells preferentially avoid death during the secretion of perforin via the degranulation of their perforin-containing organelles (lytic granules) is perplexing. Here, we demonstrate that NK cells are protected from perforin-mediated autolysis by densely packed and highly ordered presynaptic lipid membranes, which increase packing upon synapse formation. When treated with 7-ketocholesterol, lipid packing is reduced in NK cells making them susceptible to perforin-mediated lysis after degranulation. Using high-resolution imaging and lipidomics, we identified lytic granules themselves as having endogenously densely packed lipid membranes. During degranulation, lytic granule–cell membrane fusion thereby further augments presynaptic membrane packing, enhancing membrane protection at the specific sites where NK cells would face maximum concentrations of secreted perforin. Additionally, we found that an aggressive breast cancer cell line is perforin resistant and evades NK cell–mediated killing owing to a densely packed postsynaptic membrane. By disrupting membrane packing, these cells were switched to an NK-susceptible state, which could suggest strategies for improving cytotoxic cell-based cancer therapies. Thus, lipid membranes serve an unexpected role in NK cell functionality protecting them from autolysis, while degranulation allows for the inherent lytic granule membrane properties to create local ordered lipid “shields” against self-destruction.

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 NF-kB c-Rel is dispensable for the development but is required for the cytotoxic function of NK cells

2021 ◽  
Author(s):  
Y Vicioso ◽  
K Zhang ◽  
Parameswaran Ramakrishnan ◽  
Reshmi Parameswaran
Keyword(s):  
Nk Cells ◽  
Nk Cell ◽  
Granzyme B ◽  
Conditional Knockout ◽  
Cytotoxic Lymphocytes ◽  
And Control ◽  
Cytotoxic Function

AbstractNatural Killer (NK) cells are cytotoxic lymphocytes critical to the innate immune system. We found that germline deficiency of NF-kB c-Rel results in a marked decrease in cytotoxic function of NK cells, both in vitro and in vivo, with no significant differences in the stages of NK cell development. We found that c-Rel binds to the promoters of perforin and granzyme B, two key proteins required for NK cytotoxicity, and controls their transactivation. We generated a NK cell specific c-Rel conditional knockout to study NK cell intrinsic role of c-Rel and found that both global and conditional c-Rel deficiency leads to decreased perforin and granzyme B expression and thereby cytotoxic function. We also confirmed the role of c-Rel in perforin and granzyme B expression in human NK cells. c-Rel reconstitution rescued perforin and granzyme B expressions in c-Rel deficient NK cells and restored their cytotoxic function. Our results show a previously unknown role of c-Rel in transcriptional regulation of perforin and granzyme B expressions and control of NK cell cytotoxic function.

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