scholarly journals NK cells acquire epigenetic memory of LPS-induced systemic inflammation

2018 ◽  
Author(s):  
Orhan Rasid ◽  
Christine Chevalier ◽  
Tiphaine Camarasa ◽  
Catherine Fitting ◽  
Jean-Marc Cavaillon ◽  
...  
Keyword(s):  
Bacterial Infection ◽  
Nk Cells ◽  
Systemic Inflammation ◽  
Molecular Mechanisms ◽  
Nk Cell ◽  
Epigenetic Mechanism ◽  
Immune Memory ◽  
Dependent Manner ◽  
Cell Memory ◽  
Secondary Stimulation

Natural killer cells are unique mediators of innate immunity, and as such, an attractive target for immunotherapy. Following viral infection, NK cells display immune memory properties, defined by heightened responses to re-stimulation, an expansion of specific NK cell sup-populations and a protective role against re-infection. However, similar memory to bacterial infection or systemic inflammation, and the molecular mechanisms behind NK cell memory remain elusive. Here we show that following LPS-induced endotoxemia in mice, NK cells acquire cell-intrinsic memory properties as displayed by an amplified production of IFNγ upon secondary stimulation. NK cell memory is acquired even under the post-endotoxemic suppressive environment and is detectable for at least 9 weeks. Furthermore, we define an epigenetic mechanism essential for NK cell memory, where an H3K4me1-marked latent enhancer is uncovered at the ifng locus. Chemical inhibition of histone methyltransferase activity erased the enhancer and prevented NK cells from acquiring memory. Thus, NK cells develop memory to LPS during endotoxemia, in a histone methylation-dependent manner, which ensures a heightened response to secondary stimulation and confers protection against bacterial infection.

scholarly journals NK Cell Memory to Cytomegalovirus: Implications for Vaccine Development

Vaccines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 394
Author(s):  
Calum Forrest ◽  
Ariane Gomes ◽  
Matthew Reeves ◽  
Victoria Male
Keyword(s):  
Immune System ◽  
Nk Cells ◽  
Innate Immune System ◽  
Vaccine Development ◽  
Nk Cell ◽  
Innate Immune ◽  
Lymphoid Cells ◽  
Murine Cytomegalovirus ◽  
Immune Memory ◽  
Cell Memory

Natural killer (NK) cells are innate lymphoid cells that recognize and eliminate virally-infected and cancerous cells. Members of the innate immune system are not usually considered to mediate immune memory, but over the past decade evidence has emerged that NK cells can do this in several contexts. Of these, the best understood and most widely accepted is the response to cytomegaloviruses, with strong evidence for memory to murine cytomegalovirus (MCMV) and several lines of evidence suggesting that the same is likely to be true of human cytomegalovirus (HCMV). The importance of NK cells in the context of HCMV infection is underscored by the armory of NK immune evasion genes encoded by HCMV aimed at subverting the NK cell immune response. As such, ongoing studies that have utilized HCMV to investigate NK cell diversity and function have proven instructive. Here, we discuss our current understanding of NK cell memory to viral infection with a focus on the response to cytomegaloviruses. We will then discuss the implications that this will have for the development of a vaccine against HCMV with particular emphasis on how a strategy that can harness the innate immune system and NK cells could be crucial for the development of a vaccine against this high-priority pathogen.

scholarly journals Redefining Memory: Building the Case for Adaptive NK Cells

2017 ◽  
Vol 91 (20) ◽  
Author(s):  
Silke Paust ◽  
Catherine A. Blish ◽  
R. Keith Reeves
Keyword(s):  
Nk Cells ◽  
Molecular Mechanisms ◽  
Nk Cell ◽  
Murine Cytomegalovirus ◽  
The Novel ◽  
Antigen Specificity ◽  
Cell Memory ◽  
Viral Pathogens ◽  
Adaptive Capabilities ◽  
Cell Subpopulations

ABSTRACT Classically, natural killer (NK) cells have been defined by nonspecific innate killing of virus-infected and tumor cells. However, burgeoning evidence suggests that the functional repertoire of NK cells is far more diverse than has been previously appreciated, thus raising the possibility that there may be unexpected functional specialization and even adaptive capabilities among NK cell subpopulations. Some of the first evidence that NK cells respond in an antigen-specific fashion came from experiments revealing that subpopulations of murine NK cells were able to respond to a specific murine cytomegalovirus (MCMV) protein and that in the absence of T and B cells, murine NK cells also mediated adaptive immune responses to a secondary challenge with specific haptens. These data have been followed by demonstrations of NK cell memory of viruses and viral antigens in mice and primates. Herein, we discuss different forms of NK cell antigen specificity and how these responses may be tuned to specific viral pathogens, and we provide assessment of the current literature that may explain molecular mechanisms of the novel phenomenon of NK cell memory.

scholarly journals Human Cytokine-Induced Memory-Like Natural Killer Cells

2015 ◽  
Vol 7 (6) ◽  
pp. 563-571 ◽  
Author(s):  
Melissa M. Berrien-Elliott ◽  
Julia A. Wagner ◽  
Todd A. Fehniger
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Molecular Mechanisms ◽  
Nk Cell ◽  
Hematologic Malignancies ◽  
Lymphoid Cells ◽  
Cell Memory ◽  
And Function ◽  
Activation Event ◽  
Cell Effector

Natural killer (NK) cells are innate lymphoid cells that are important for host defense against infection and mediate antitumor responses. Recent reports from several laboratories have identified that NK cells can remember a prior activation event and consequently respond more robustly when restimulated, a property termed innate NK cell memory. NK cell memory has now been identified following hapten exposure, viral infection, and combined cytokine preactivation with IL-12, IL-15, and IL-18. Many questions in the field remain regarding the cellular and molecular mechanisms regulating memory NK cells and their responses, as well as their formation and function in mice and humans. Here we review our current understanding of cytokine-induced memory-like (CIML) NK cells that are generated by combined preactivation with IL-12, IL-15, and IL-18. These cells exhibit enhanced NK cell effector functions weeks after the initial cytokine preactivation. Further, we highlight the preclinical rationale and ongoing therapeutic application of CIML NK cells for adoptive immunotherapy in patients with hematologic malignancies.

scholarly journals Decrease post-transplant relapse using donor-derived expanded NK-cells

Leukemia ◽  
2021 ◽  
Author(s):  
Stefan O. Ciurea ◽  
Piyanuch Kongtim ◽  
Doris Soebbing ◽  
Prashant Trikha ◽  
Gregory Behbehani ◽  
...  
Keyword(s):  
Nk Cells ◽  
Nk Cell ◽  
Ex Vivo ◽  
Disease Free Survival ◽  
Dependent Manner ◽  
Post Transplant ◽  
Haploidentical Transplantation ◽  
High Doses ◽  
High Level

AbstractIn this phase I/II clinical trial, we investigated the safety and efficacy of high doses of mb-IL21 ex vivo expanded donor-derived NK cells to decrease relapse in 25 patients with myeloid malignancies receiving haploidentical stem-cell transplantation (HSCT). Three doses of donor NK cells (1 × 105–1 × 108 cells/kg/dose) were administered on days −2, +7, and +28. Results were compared with an independent contemporaneously treated case-matched cohort of 160 patients from the CIBMTR database.After a median follow-up of 24 months, the 2-year relapse rate was 4% vs. 38% (p = 0.014), and disease-free survival (DFS) was 66% vs. 44% (p = 0.1) in the cases and controls, respectively. Only one relapse occurred in the study group, in a patient with the high level of donor-specific anti-HLA antibodies (DSA) presented before transplantation. The 2-year relapse and DFS in patients without DSA was 0% vs. 40% and 72% vs. 44%, respectively with HR for DFS in controls of 2.64 (p = 0.029). NK cells in recipient blood were increased at day +30 in a dose-dependent manner compared with historical controls, and had a proliferating, mature, highly cytotoxic, NKG2C+/KIR+ phenotype.Administration of donor-derived expanded NK cells after haploidentical transplantation was safe, associated with NK cell-dominant immune reconstitution early post-transplant, preserved T-cell reconstitution, and improved relapse and DFS. TRIAL REGISTRATION: NCT01904136 (https://clinicaltrials.gov/ct2/show/NCT01904136).

scholarly journals GSK-3α Inhibition in Drug-Resistant CML Cells Promotes Susceptibility to NK Cell-Mediated Lysis in an NKG2D- and NKp30-Dependent Manner

Cancers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1802
Author(s):  
Nayoung Kim ◽  
Mi Yeon Kim ◽  
Woo Seon Choi ◽  
Eunbi Yi ◽  
Hyo Jung Lee ◽  
...  
Keyword(s):  
Nk Cells ◽  
Nk Cell ◽  
Negative Regulator ◽  
Target Cells ◽  
Dependent Manner ◽  
Cell Functions ◽  
Cell Based Therapy ◽  
Activating Receptors ◽  
Gsk 3Β

Natural killer (NK) cells are innate cytotoxic lymphocytes that provide early protection against cancer. NK cell cytotoxicity against cancer cells is triggered by multiple activating receptors that recognize specific ligands expressed on target cells. We previously demonstrated that glycogen synthase kinase (GSK)-3β, but not GSK-3α, is a negative regulator of NK cell functions via diverse activating receptors, including NKG2D and NKp30. However, the role of GSK-3 isoforms in the regulation of specific ligands on target cells is poorly understood, which remains a challenge limiting GSK-3 targeting for NK cell-based therapy. Here, we demonstrate that GSK-3α rather than GSK-3β is the primary isoform restraining the expression of NKG2D ligands, particularly ULBP2/5/6, on tumor cells, thereby regulating their susceptibility to NK cells. GSK-3α also regulated the expression of the NKp30 ligand B7-H6, but not the DNAM-1 ligands PVR or nectin-2. This regulation occurred independently of BCR-ABL1 mutation that confers tyrosine kinase inhibitor (TKI) resistance. Mechanistically, an increase in PI3K/Akt signaling in concert with c-Myc was required for ligand upregulation in response to GSK-3α inhibition. Importantly, GSK-3α inhibition improved cancer surveillance by human NK cells in vivo. Collectively, our results highlight the distinct role of GSK-3 isoforms in the regulation of NK cell reactivity against target cells and suggest that GSK-3α modulation could be used to enhance tumor cell susceptibility to NK cells in an NKG2D- and NKp30-dependent manner.

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 Inhibition of Enhancer of zeste homolog 2 (EZH2) induces natural killer cell-mediated eradication of hepatocellular carcinoma cells

2018 ◽  
Vol 115 (15) ◽  
pp. E3509-E3518 ◽  
Author(s):  
Suresh Bugide ◽  
Michael R. Green ◽  
Narendra Wajapeyee
Keyword(s):  
Hepatocellular Carcinoma ◽  
Nk Cells ◽  
Natural Killer ◽  
Nk Cell ◽  
Killer Cell ◽  
Transcriptional Level ◽  
Dependent Manner ◽  
Down Regulation ◽  
Nkg2d Ligands ◽  
Enhancer Of Zeste

Natural killer (NK) cell-mediated tumor cell eradication could inhibit tumor initiation and progression. However, the factors that regulate NK cell-mediated cancer cell eradication remain unclear. We determined that hepatocellular carcinoma (HCC) cells exhibit transcriptional down-regulation of NK group 2D (NKG2D) ligands and are largely resistant to NK cell-mediated eradication. Because the down-regulation of NKG2D ligands occurred at the transcriptional level, we tested 32 chemical inhibitors of epigenetic regulators for their ability to re-express NKG2D ligands and enhance HCC cell eradication by NK cells and found that Enhancer of zeste homolog 2 (EZH2) was a transcriptional repressor of NKG2D ligands. The inhibition of EZH2 by small-molecule inhibitors or genetic means enhanced HCC cell eradication by NK cells in a NKG2D ligand-dependent manner. Collectively, these results demonstrate that EZH2 inhibition enhances HCC eradication by NK cells and that EZH2 functions, in part, as an oncogene by inhibiting immune response.

HBV vaccination and HBV infection induces HBV-specific natural killer cell memory

Gut ◽  
2020 ◽  
pp. gutjnl-2019-319252 ◽  
Author(s):  
Ratna S Wijaya ◽  
Scott A Read ◽  
Naomi R Truong ◽  
Shuanglin Han ◽  
Dishen Chen ◽  
...  
Keyword(s):  
Hepatitis B ◽  
Nk Cells ◽  
Natural Killer ◽  
Nk Cell ◽  
Killer Cell ◽  
Hbv Infection ◽  
Core Antigen ◽  
Dependent Manner ◽  
Antigen Specificity ◽  
Chronic Hbv

ObjectiveVaccination against hepatitis B virus (HBV) confers protection from subsequent infection through immunological memory that is traditionally considered the domain of the adaptive immune system. This view has been challenged following the identification of antigen-specific memory natural killer cells (mNKs) in mice and non-human primates. While the presence of mNKs has been suggested in humans based on the expansion of NK cells following pathogen exposure, evidence regarding antigen-specificity is lacking. Here, we demonstrate the existence of HBV-specific mNKs in humans after vaccination and in chronic HBV infection.DesignNK cell responses were evaluated by flow cytometry and ELISA following challenge with HBV antigens in HBV vaccinated, non-vaccinated and chronic HBV-infected individuals.ResultsNK cells from vaccinated subjects demonstrated higher cytotoxic and proliferative responses against autologous hepatitis B surface antigen (HBsAg)-pulsed monocyte-derived dendritic cells (moDCs) compared with unvaccinated subjects. Moreover, NK cell lysis of HBsAg-pulsed moDCs was significantly higher than that of hepatitis B core antigen (HBcAg)-pulsed moDCs (non-vaccine antigen) or tumour necrosis factor α-activated moDCs in a NKG2D-dependent manner. The mNKs response was mediated by CD56dim NK cells coexpressing CD57, CD69 and KLRG1. Further, mNKs from chronic hepatitis B patients exhibited greater degranulation against HBcAg-pulsed moDCs compared with unvaccinated or vaccinated patients. Notably, mNK activity was negatively correlated with HBV DNA levels.ConclusionsOur data support the presence of a mature mNKs following HBV antigen exposure either through vaccination or infection. Harnessing these antigen specific, functionally active mNKs provides an opportunity to develop novel treatments targeting HBV in chronic infection.

scholarly journals Enhanced adaptive immune responses in lung adenocarcinoma through natural killer cell stimulation

2019 ◽  
Vol 116 (35) ◽  
pp. 17460-17469 ◽  
Author(s):  
Leah Schmidt ◽  
Banu Eskiocak ◽  
Ryan Kohn ◽  
Celeste Dang ◽  
Nikhil S. Joshi ◽  
...  
Keyword(s):  
T Cells ◽  
Lung Adenocarcinoma ◽  
Nk Cells ◽  
Natural Killer ◽  
Nk Cell ◽  
Killer Cell ◽  
Production Capacity ◽  
Dependent Manner ◽  
Cell Stimulation ◽  
Established Disease

Natural killer (NK) cells inhibit tumor development in mouse models and their presence in tumors correlates with patient survival. However, tumor-associated NK cells become dysfunctional; thus, stimulation of NK cells in cancer is emerging as an attractive immunotherapeutic strategy. In a mouse model of lung adenocarcinoma, NK cells localized to tumor stroma with immature phenotypes and low functional capacity. To test their responsiveness within established disease, we engineered a system for inducible expression of activating ligands in tumors. After stimulation, NK cells localized inside tumors, with increased cytokine production capacity. Strikingly, T cells were also recruited to tumors in an NK cell-dependent manner, and exhibited higher functionality. In neoantigen-expressing tumors, NK cell stimulation enhanced the number and function of tumor-specific T cells and, in long-term settings, reduced tumor growth. Thus, even in established disease NK cells can be activated to contribute to antitumor immunity, supporting their potential as an important target in cancer immunotherapy.

scholarly journals The Tumor Microenvironment—A Metabolic Obstacle to NK Cells’ Activity

Cancers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3542
Author(s):  
Joanna Domagala ◽  
Mieszko Lachota ◽  
Marta Klopotowska ◽  
Agnieszka Graczyk-Jarzynka ◽  
Antoni Domagala ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Nk Cells ◽  
Molecular Mechanisms ◽  
Cell Function ◽  
Nk Cell ◽  
Metabolic Changes ◽  
Immune Effector ◽  
Effector Cells ◽  
Immune Effector Cells ◽  
Almost All

NK cells have unique capabilities of recognition and destruction of tumor cells, without the requirement for prior immunization of the host. Maintaining tolerance to healthy cells makes them an attractive therapeutic tool for almost all types of cancer. Unfortunately, metabolic changes associated with malignant transformation and tumor progression lead to immunosuppression within the tumor microenvironment, which in turn limits the efficacy of various immunotherapies. In this review, we provide a brief description of the metabolic changes characteristic for the tumor microenvironment. Both tumor and tumor-associated cells produce and secrete factors that directly or indirectly prevent NK cell cytotoxicity. Here, we depict the molecular mechanisms responsible for the inhibition of immune effector cells by metabolic factors. Finally, we summarize the strategies to enhance NK cell function for the treatment of tumors.

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