Metabolic but not transcriptional regulation by PKM2 is important for Natural Killer cell responses

AbstractNatural Killer (NK) cells have an important role in immune responses to viruses and tumours. Integrating changes in signal transduction pathways and cellular metabolism is essential for effective NK cells responses. The PKM2 isoform of the glycolytic enzyme Pyruvate Kinase Muscle has described roles in regulating glycolytic flux and signal transduction, especially gene transcription. While PKM2 expression is robustly induced in activated NK cells, mice lacking PKM2 in NK cells showed no defect in NK cell metabolism or anti-viral responses to MCMV infection. This maintenance of function is explained by compensatory PKM1 expression in PKM2-null NK cell cells demonstrating that PKM2 is not a signalling molecule in this immune cell type. To further investigate the role of PKM2 we forced the tetramerization of the protein with TEPP-46, which increases its catalytic activity while inhibiting any signalling functions mediated by mono/dimeric conformations. NK cells activated with TEPP-46 had reduced effector function due to TEPP-46-induced increases in oxidative stress. Overall, PKM2-regulated glycolytic metabolism and redox status, not transcriptional control, facilitate optimal NK cells responses.

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Metabolic but not transcriptional regulation by PKM2 is important for natural killer cell responses

eLife ◽

10.7554/elife.59166 ◽

2020 ◽

Vol 9 ◽

Author(s):

Jessica F Walls ◽

Jeff J Subleski ◽

Erika M Palmieri ◽

Marieli Gonzalez-Cotto ◽

Clair M Gardiner ◽

...

Keyword(s):

Signal Transduction ◽

Nk Cells ◽

Natural Killer ◽

Transcriptional Control ◽

Nk Cell ◽

Cell Metabolism ◽

Killer Cell ◽

Glycolytic Enzyme ◽

Glycolytic Flux ◽

Mcmv Infection

Natural Killer (NK) cells have an important role in immune responses to viruses and tumours. Integrating changes in signal transduction pathways and cellular metabolism is essential for effective NK cells responses. The glycolytic enzyme Pyruvate Kinase Muscle 2 (PKM2) has described roles in regulating glycolytic flux and signal transduction, particularly gene transcription. While PKM2 expression is robustly induced in activated NK cells, mice lacking PKM2 in NK cells showed no defect in NK cell metabolism, transcription or antiviral responses to MCMV infection. NK cell metabolism was maintained due to compensatory PKM1 expression in PKM2-null NK cells. To further investigate the role of PKM2, we used TEPP-46, which increases PKM2 catalytic activity while inhibiting any PKM2 signalling functions. NK cells activated with TEPP-46 had reduced effector function due to TEPP-46-induced increases in oxidative stress. Overall, PKM2-regulated glycolytic metabolism and redox status, not transcriptional control, facilitate optimal NK cells responses.

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A natural killer cell gene signature predicts melanoma patient survival

10.1101/375253 ◽

2018 ◽

Author(s):

Joseph Cursons ◽

Fernando Souza-Fonseca-Guimaraes ◽

Ashley Anderson ◽

Momeneh Foroutan ◽

Soroor Hediyeh-Zadeh ◽

...

Keyword(s):

Nk Cells ◽

Natural Killer ◽

Solid Tumors ◽

Immune Cell ◽

Nk Cell ◽

Killer Cell ◽

Cell Activity ◽

Human Tumors ◽

The Cancer Genome Atlas ◽

Cell Gene

AbstractAnimal models have demonstrated that natural killer (NK) cells can limit the metastatic dissemination of tumors, however their ability to combat established human tumors has been difficult to investigate.A number of computational methods have been developed for the deconvolution of immune cell types within solid tumors. We have taken the NK cell gene signatures from several tools, then curated and expanded this list using recent reports from the literature. Using a gene set scoring method to investigate RNA-seq data from The Cancer Genome Atlas (TCGA) we show that patients with metastatic cutaneous melanoma have an improved survival rate if their tumor shows evidence of greater NK cell infiltration. Furthermore, these survival effects are enhanced in tumors which have a higher expression of NK cell stimuli such as IL-15, suggesting NK cells are part of a coordinated immune response within these patients. Using this signature we then examine transcriptomic data to identify tumor and stromal components which may influence the penetrance of NK cells into solid tumors.These data support a role for NK cells in the regulation of human tumors and highlight potential survival effects associated with increased NK cell activity. Furthermore, our computational analysis identifies a number of potential targets which may help to unleash the anti-tumor potential of NK cells as we enter the age of immunotherapy.

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Proinflammatory cytokine signaling required for the generation of natural killer cell memory

Journal of Experimental Medicine ◽

10.1084/jem.20111760 ◽

2012 ◽

Vol 209 (5) ◽

pp. 947-954 ◽

Cited By ~ 176

Author(s):

Joseph C. Sun ◽

Sharline Madera ◽

Natalie A. Bezman ◽

Joshua N. Beilke ◽

Mark H. Kaplan ◽

...

Keyword(s):

Nk Cells ◽

Natural Killer ◽

Nk Cell ◽

Killer Cell ◽

Interleukin 12 ◽

Cytokine Signaling ◽

Mcmv Infection ◽

Ifn Γ ◽

Deficient Mice ◽

Memory Nk Cells

Although natural killer (NK) cells are classified as innate immune cells, recent studies demonstrate that NK cells can become long-lived memory cells and contribute to secondary immune responses. The precise signals that promote generation of long-lived memory NK cells are unknown. Using cytokine receptor-deficient mice, we show that interleukin-12 (IL-12) is indispensible for mouse cytomegalovirus (MCMV)-specific NK cell expansion and generation of memory NK cells. In contrast to wild-type NK cells that proliferated robustly and resided in lymphoid and nonlymphoid tissues for months after MCMV infection, IL-12 receptor–deficient NK cells failed to expand and were unable to mediate protection after MCMV challenge. We further demonstrate that a STAT4-dependent IFN-γ–independent mechanism contributes toward the generation of memory NK cells during MCMV infection. Understanding the full contribution of inflammatory cytokine signaling to the NK cell response against viral infection will be of interest for the development of vaccines and therapeutics.

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The Cytomegalovirus m155 Gene Product Subverts Natural Killer Cell Antiviral Protection by Disruption of H60–NKG2D Interactions

Journal of Experimental Medicine ◽

10.1084/jem.20040583 ◽

2004 ◽

Vol 200 (8) ◽

pp. 1075-1081 ◽

Cited By ~ 106

Author(s):

Melissa B. Lodoen ◽

Gerardo Abenes ◽

Sean Umamoto ◽

Jeffrey P. Houchins ◽

Fenyong Liu ◽

...

Keyword(s):

Nk Cells ◽

Natural Killer ◽

Nk Cell ◽

Killer Cell ◽

Proteasome Inhibitors ◽

Mutant Virus ◽

Murine Cytomegalovirus ◽

Down Regulation ◽

Mcmv Infection ◽

Affinity Ligand

Natural killer (NK) cells are an important early mediator of host immunity to murine cytomegalovirus (MCMV) infection. However, MCMV has evolved mechanisms to elude recognition and clearance by NK cells. We have identified an MCMV immune evasion protein that impairs NKG2D-mediated NK cell antiviral activity. Infection of BALB/c 3T3 cells with the Smith strain of MCMV resulted in strong down-regulation of H60, a high affinity ligand for NKG2D, from the surface of virus-infected cells. The MCMV m155 protein specifically down-regulated H60 without affecting expression of the other known NKG2D ligands, RAE-1 and MULT-1. Treatment with the proteasome inhibitors lactacystin or epoxomicin reversed m155 down-regulation of H60. An MCMV mutant virus lacking m155 was severely attenuated in BALB/c mice; however, treatment with neutralizing anti-NKG2D monoclonal antibody or with NK-depleting anti-asialo GM1 antisera restored virulence of the mutant virus. Thus, down-regulation of H60 by m155 is a powerful mechanism of inhibiting NKG2D-mediated antiviral function.

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Natural Killer Cells Are Present in Rag1−/− Mice and Promote Tissue Damage During the Acute Phase of Ischemic Stroke

Translational Stroke Research ◽

10.1007/s12975-021-00923-3 ◽

2021 ◽

Author(s):

Leoni Rolfes ◽

Tobias Ruck ◽

Christina David ◽

Stine Mencl ◽

Stefanie Bock ◽

...

Keyword(s):

Nk Cells ◽

Natural Killer ◽

Adoptive Transfer ◽

Immune Cell ◽

Nk Cell ◽

Cell Subset ◽

Neurological Deficits ◽

In Vitro Assays ◽

Experimental Stroke ◽

Transfer Model

AbstractRag1−/− mice, lacking functional B and T cells, have been extensively used as an adoptive transfer model to evaluate neuroinflammation in stroke research. However, it remains unknown whether natural killer (NK) cell development and functions are altered in Rag1−/− mice as well. This connection has been rarely discussed in previous studies but might have important implications for data interpretation. In contrast, the NOD-Rag1nullIL2rgnull (NRG) mouse model is devoid of NK cells and might therefore eliminate this potential shortcoming. Here, we compare immune-cell frequencies as well as phenotype and effector functions of NK cells in Rag1−/− and wildtype (WT) mice using flow cytometry and functional in vitro assays. Further, we investigate the effect of Rag1−/− NK cells in the transient middle cerebral artery occlusion (tMCAO) model using antibody-mediated depletion of NK cells and adoptive transfer to NRG mice in vivo. NK cells in Rag1−/− were comparable in number and function to those in WT mice. Rag1−/− mice treated with an anti-NK1.1 antibody developed significantly smaller infarctions and improved behavioral scores. Correspondingly, NRG mice supplemented with NK cells were more susceptible to tMCAO, developing infarctions and neurological deficits similar to Rag1−/− controls. Our results indicate that NK cells from Rag1−/− mice are fully functional and should therefore be considered in the interpretation of immune-cell transfer models in experimental stroke. Fortunately, we identified the NRG mice, as a potentially better-suited transfer model to characterize individual cell subset-mediated neuroinflammation in stroke.

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The m15 Locus of Murine Cytomegalovirus Modulates Natural Killer Cell Responses to Promote Dissemination to the Salivary Glands and Viral Shedding

Pathogens ◽

10.3390/pathogens10070866 ◽

2021 ◽

Vol 10 (7) ◽

pp. 866

Author(s):

Baca Chan ◽

Maja Arapović ◽

Laura Masters ◽

Francois Rwandamuiye ◽

Stipan Jonjić ◽

...

Keyword(s):

Nk Cells ◽

Salivary Glands ◽

Natural Killer ◽

Nk Cell ◽

Acute Infection ◽

Killer Cell ◽

Viral Escape ◽

Murine Cytomegalovirus ◽

Viral Shedding ◽

Cell Responses

As the largest herpesviruses, the 230 kb genomes of cytomegaloviruses (CMVs) have increased our understanding of host immunity and viral escape mechanisms, although many of the annotated genes remain as yet uncharacterised. Here we identify the m15 locus of murine CMV (MCMV) as a viral modulator of natural killer (NK) cell immunity. We show that, rather than discrete transcripts from the m14, m15 and m16 genes as annotated, there are five 3′-coterminal transcripts expressed over this region, all utilising a consensus polyA tail at the end of the m16 gene. Functional inactivation of any one of these genes had no measurable impact on viral replication. However, disruption of all five transcripts led to significantly attenuated dissemination to, and replication in, the salivary glands of multiple strains of mice, but normal growth during acute infection. Disruption of the m15 locus was associated with heightened NK cell responses, including enhanced proliferation and IFNγ production. Depletion of NK cells, but not T cells, rescued salivary gland replication and viral shedding. These data demonstrate the identification of multiple transcripts expressed by a single locus which modulate, perhaps in a concerted fashion, the function of anti-viral NK cells.

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Impact of β2 integrin deficiency on mouse natural killer cell development and function

Blood ◽

10.1182/blood-2010-10-315457 ◽

2011 ◽

Vol 117 (10) ◽

pp. 2874-2882 ◽

Cited By ~ 18

Author(s):

Karine Crozat ◽

Céline Eidenschenk ◽

Baptiste N. Jaeger ◽

Philippe Krebs ◽

Sophie Guia ◽

...

Keyword(s):

Cell Surface ◽

Nk Cells ◽

Natural Killer ◽

Nk Cell ◽

Surface Expression ◽

Cell Maturation ◽

Cell Surface Expression ◽

Mcmv Infection ◽

Β2 Integrin

Abstract Natural killer (NK) cells are innate immune cells that express members of the leukocyte β2 integrin family in humans and mice. These CD11/CD18 heterodimers play critical roles in leukocyte trafficking, immune synapse formation, and costimulation. The cell-surface expression of one of these integrins, CD11b/CD18, is also recognized as a major marker of mouse NK-cell maturation, but its function on NK cells has been largely ignored. Using N-ethyl-N-nitrosourea (ENU) mutagenesis, we generated a mouse carrying an A → T transverse mutation in the Itgb2 gene, resulting in a mutation that prevented the cell-surface expression of CD18 and its associated CD11a, CD11b, and CD11c proteins. We show that β2 integrin–deficient NK cells have a hyporesponsive phenotype in vitro, and present an alteration of their in vivo developmental program characterized by a selective accumulation of c-kit+ cells. NK-cell missing-self recognition was partially altered in vivo, whereas the early immune response to mouse cytomegalovirus (MCMV) infection occurred normally in CD18-deficient mice. Therefore, β2 integrins are required for optimal NK-cell maturation, but this deficiency is partial and can be bypassed during MCMV infection, highlighting the robustness of antiviral protective responses.

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Natural Killer Cell Mobilization in Breast and Prostate Cancer Survivors: The Implications of Altered Stress Hormones Following Acute Exercise

Endocrines ◽

10.3390/endocrines2020012 ◽

2021 ◽

Vol 2 (2) ◽

pp. 121-132

Author(s):

Erik D. Hanson ◽

Lauren C. Bates ◽

Kaileigh Moertl ◽

Elizabeth S. Evans

Keyword(s):

Prostate Cancer ◽

Immune System ◽

Cancer Survivors ◽

Nk Cells ◽

Natural Killer ◽

Acute Exercise ◽

Nk Cell ◽

Killer Cell ◽

Current Evidence ◽

Cell Mobilization

Natural killer (NK) cells from the innate immune system are integral to overall immunity and also in managing the tumor burden during cancer. Breast (BCa) and prostate cancer (PCa) are the most common tumors in U.S. adults. Both BCa and PCa are frequently treated with hormone suppression therapies that are associated with numerous adverse effects including direct effects on the immune system. Regular exercise is recommended for cancer survivors to reduce side effects and improve quality of life. Acute exercise is a potent stimulus for NK cells in healthy individuals with current evidence indicating that NK mobilization in individuals with BCa and PCa is comparable. NK cell mobilization results from elevations in shear stress and catecholamine levels. Despite a normal NK cell response to exercise, increases in epinephrine are attenuated in BCa and PCa. The significance of this potential discrepancy still needs to be determined. However, alterations in adrenal hormone signaling are hypothesized to be due to chronic stress during cancer treatment. Additional compensatory factors induced by exercise are reviewed along with recommendations on standardized approaches to be used in exercise immunology studies involving oncology populations.

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Approaches to Enhance Natural Killer Cell-Based Immunotherapy for Pediatric Solid Tumors

Cancers ◽

10.3390/cancers13112796 ◽

2021 ◽

Vol 13 (11) ◽

pp. 2796

Author(s):

Aicha E. Quamine ◽

Mallery R. Olsen ◽

Monica M. Cho ◽

Christian M. Capitini

Keyword(s):

Nk Cells ◽

Natural Killer ◽

Solid Tumors ◽

Nk Cell ◽

Therapeutic Option ◽

Treatment Options ◽

Intensive Therapy ◽

Killer Cell ◽

Cell Therapies ◽

Pediatric Solid Tumors

Treatment of metastatic pediatric solid tumors remain a significant challenge, particularly in relapsed and refractory settings. Standard treatment has included surgical resection, radiation, chemotherapy, and, in the case of neuroblastoma, immunotherapy. Despite such intensive therapy, cancer recurrence is common, and most tumors become refractory to prior therapy, leaving patients with few conventional treatment options. Natural killer (NK) cells are non-major histocompatibility complex (MHC)-restricted lymphocytes that boast several complex killing mechanisms but at an added advantage of not causing graft-versus-host disease, making use of allogeneic NK cells a potential therapeutic option. On top of their killing capacity, NK cells also produce several cytokines and growth factors that act as key regulators of the adaptive immune system, positioning themselves as ideal effector cells for stimulating heavily pretreated immune systems. Despite this promise, clinical efficacy of adoptive NK cell therapy to date has been inconsistent, prompting a detailed understanding of the biological pathways within NK cells that can be leveraged to develop “next generation” NK cell therapies. Here, we review advances in current approaches to optimizing the NK cell antitumor response including combination with other immunotherapies, cytokines, checkpoint inhibition, and engineering NK cells with chimeric antigen receptors (CARs) for the treatment of pediatric solid tumors.

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The Potential for Cancer Immunotherapy in Targeting Surgery-Induced Natural Killer Cell Dysfunction

Cancers ◽

10.3390/cancers11010002 ◽

2018 ◽

Vol 11 (1) ◽

pp. 2 ◽

Cited By ~ 7

Author(s):

Marisa Market ◽

Katherine Baxter ◽

Leonard Angka ◽

Michael Kennedy ◽

Rebecca Auer

Keyword(s):

Nk Cells ◽

Natural Killer ◽

Cell Biology ◽

Nk Cell ◽

Clonal Selection ◽

Killer Cell ◽

Cancer Recurrence ◽

Effector Functions ◽

Cell Dysfunction ◽

Cell Functions

Natural Killer (NK) cells are granular lymphocytes of the innate immune system that are able to recognize and kill tumor cells without undergoing clonal selection. Discovered over 40 years ago, they have since been recognized to possess both cytotoxic and cytokine-producing effector functions. Following trauma, NK cells are suppressed and their effector functions are impaired. This is especially important for cancer patients undergoing the removal of solid tumors, as surgery has shown to contribute to the development of metastasis and cancer recurrence postoperatively. We have recently shown that NK cells are critical mediators in the formation of metastasis after surgery. While research into the mechanism(s) responsible for NK cell dysfunction is ongoing, knowledge of these mechanisms will pave the way for perioperative therapeutics with the potential to improve cancer outcomes by reversing NK cell dysfunction. This review will discuss mechanisms of suppression in the postoperative environment, including hypercoagulability, suppressive soluble factors, the expansion of suppressive cell populations, and how this affects NK cell biology, including modulation of cell surface receptors, the potential for anergy, and immunosuppressive NK cell functions. This review will also outline potential immunotherapies to reverse postoperative NK dysfunction, with the goal of preventing surgery-induced metastasis.

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