scholarly journals Cytokine induced natural killer cell training is dependent on cellular metabolism and is defective in obesity

2021 ◽  
Author(s):  
Nidhi Kedia-Mehta ◽  
Laura Tobin ◽  
Vanessa Zaiatz-Bittencourt ◽  
Marta Pisarska ◽  
Conor De Barra ◽  
...  
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Nk Cell ◽  
Cell Metabolism ◽  
Initial Period ◽  
Killer Cell ◽  
Cellular Metabolism ◽  
Cell Responses ◽  
Cytokine Activation ◽  
Metabolic Signalling

Natural killer (NK) cells are a population of innate immune cells which can rapidily kill cancer cells and produce cytokines such as interferon gamma (IFN-gamma). A key feature of NK cells is their ability to respond without prior sensitation, however it is now well established that NK cells can possess memory-like features. After activation with cytokines, NK cells demonstrate enhanced effector functions upon restimulation days or weeks later. This demonstrates that NK cells may be "trained" to be more effective killers and harnessed as more potent cancer immunotherapy agents. We have previously demonstrated that cellular metabolism is essential for NK cell responses, with NK cells upregulating both glycolysis and oxidative phosphorylation upon cytokine stimulation. Limiting NK cell metabolism results in reduced cytotoxicity and cytokine production. We have also demonstrated that defective NK cell responses in obesity are linked to defective cellular metabolism. In the current study we investigated if cellular metabolism is required during the initial period of NK cell cytokine training, and if NK cells from people with obesity (PWO) can be effectively trained. We show that increased flux through glycolysis and OXPHOS during the initial cytokine activation period is essential for NK cell training, as is the metabolic signalling factor Srepb. We show that NK cells from PWO, which are metabolically defective, display impaired NK cell training, which may have implications for immunotherapy in this particularly vulnerable group.

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

Pathogens ◽  
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.

scholarly journals Glycosylation Affects Ligand Binding and Function of the Activating Natural Killer Cell Receptor 2B4 (CD244) Protein

2011 ◽  
Vol 286 (27) ◽  
pp. 24142-24149 ◽  
Author(s):  
Stefanie Margraf-Schönfeld ◽  
Carolin Böhm ◽  
Carsten Watzl
Keyword(s):  
Ligand Binding ◽  
Nk Cells ◽  
Natural Killer ◽  
Cell Function ◽  
Nk Cell ◽  
Negative Impact ◽  
Killer Cell ◽  
Target Cells ◽  
Functional Assay ◽  
Cell Responses

2B4 (CD244) is an important activating receptor for the regulation of natural killer (NK) cell responses. Here we show that 2B4 is heavily and differentially glycosylated in primary human NK cells and NK cell lines. The differential glycosylation could be attributed to sialic acid residues on N- and O-linked carbohydrates. Using a recombinant fusion protein of the extracellular domain of 2B4, we demonstrate that N-linked glycosylation of 2B4 is essential for the binding to its ligand CD48. In contrast, sialylation of 2B4 has a negative impact on ligand binding, as the interaction between 2B4 and CD48 is increased after the removal of sialic acids. This was confirmed in a functional assay system, where the desialylation of NK cells or the inhibition of O-linked glycosylation resulted in increased 2B4-mediated lysis of CD48-expressing tumor target cells. These data demonstrate that glycosylation has an important impact on 2B4-mediated NK cell function and suggest that regulated changes in glycosylation during NK cell development and activation might be involved in the regulation of NK cell responses.

scholarly journals Age-dependent susceptibility to a viral disease due to decreased natural killer cell numbers and trafficking

2010 ◽  
Vol 207 (11) ◽  
pp. 2369-2381 ◽  
Author(s):  
Min Fang ◽  
Felicia Roscoe ◽  
Luis J. Sigal
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Cell Function ◽  
Nk Cell ◽  
Killer Cell ◽  
Viral Disease ◽  
Viral Diseases ◽  
Cell Responses ◽  
Loss Of Resistance ◽  
Age Dependent

Although it is well known that aged hosts are generally more susceptible to viral diseases than the young, specific dysfunctions of the immune system directly responsible for this increased susceptibility have yet to be identified. We show that mice genetically resistant to mousepox (the mouse parallel of human smallpox) lose resistance at mid-age. Surprisingly, this loss of resistance is not a result of intrinsically defective T cell responses. Instead, the primary reason for the loss of resistance results from a decreased number of total and mature natural killer (NK) cells in the blood and an intrinsic impairment in their ability to migrate to the lymph node draining the site of infection, which is essential to curb systemic virus spread. Hence, our work links the age-dependent increase in susceptibility to a viral disease to a specific defect of NK cells, opening the possibility of exploring treatments to improve NK cell function in the aged with the goal of enhancing their resistance to viral diseases.

scholarly journals Natural Killer Cell Responses during Human γ-Herpesvirus Infections

Vaccines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 655
Author(s):  
Christian Münz
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Epstein Barr Virus ◽  
Nk Cell ◽  
Killer Cell ◽  
Kaposi Sarcoma ◽  
Antibody Dependent Cellular Cytotoxicity ◽  
Barr Virus ◽  
Cell Responses ◽  
Epstein Barr

Herpesviruses are main sculptors of natural killer (NK) cell repertoires. While the β-herpesvirus human cytomegalovirus (CMV) drives the accumulation of adaptive NKG2C-positive NK cells, the human γ-herpesvirus Epstein–Barr virus (EBV) expands early differentiated NKG2A-positive NK cells. While adaptive NK cells support adaptive immunity by antibody-dependent cellular cytotoxicity, NKG2A-positive NK cells seem to preferentially target lytic EBV replicating B cells. The importance of this restriction of EBV replication during γ-herpesvirus pathogenesis will be discussed. Furthermore, the modification of EBV-driven NK cell expansion by coinfections, including by the other human γ-herpesvirus Kaposi sarcoma-associated herpesvirus (KSHV), will be summarized.

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

eLife ◽  
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.

scholarly journals Tim-3 marks human natural killer cell maturation and suppresses cell-mediated cytotoxicity

Blood ◽  
2012 ◽  
Vol 119 (16) ◽  
pp. 3734-3743 ◽  
Author(s):  
Lishomwa C. Ndhlovu ◽  
Sandra Lopez-Vergès ◽  
Jason D. Barbour ◽  
R. Brad Jones ◽  
Aashish R. Jha ◽  
...  
Keyword(s):  
T Cell ◽  
Nk Cells ◽  
Natural Killer ◽  
Nk Cell ◽  
Killer Cell ◽  
Cell Subset ◽  
Target Cells ◽  
Type I ◽  
Human Natural Killer Cell ◽  
Cell Responses

Abstract Natural killer (NK) cells are innate lymphocytes that play an important role against viral infections and cancer. This effect is achieved through a complex mosaic of inhibitory and activating receptors expressed by NK cells that ultimately determine the magnitude of the NK-cell response. The T-cell immunoglobulin– and mucin domain–containing (Tim)–3 receptor was initially identified as a T-helper 1–specific type I membrane protein involved in regulating T-cell responses. Human NK cells transcribe the highest amounts of Tim-3 among lymphocytes. Tim-3 protein is expressed on essentially all mature CD56dimCD16+ NK cells and is expressed heterogeneously in the immature CD56brightCD16– NK-cell subset in blood from healthy adults and in cord blood. Tim-3 expression was induced on CD56brightCD16− NK cells after stimulation with IL-15 or IL-12 and IL-18 in vitro, suggesting that Tim-3 is a maturation marker on NK cells. Whereas Tim-3 has been used to identify dysfunctional T cells, NK cells expressing high amounts of Tim-3 are fully responsive with respect to cytokine production and cytotoxicity. However, when Tim-3 was cross-linked with antibodies it suppressed NK cell–mediated cytotoxicity. These findings suggest that NK-cell responses may be negatively regulated when NK cells encounter target cells expressing cognate ligands of Tim-3.

scholarly journals Durable natural killer cell responses after heterologous two-dose Ebola vaccination

npj Vaccines ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Helen R. Wagstaffe ◽  
Giada Susannini ◽  
Rodolphe Thiébaut ◽  
Laura Richert ◽  
Yves Lévy ◽  
...  
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Cell Activation ◽  
Ebola Virus ◽  
Nk Cell ◽  
Ex Vivo ◽  
Killer Cell ◽  
Post Dose ◽  
Vaccine Regimen ◽  
Cell Responses

AbstractNatural killer (NK) cells are implicated among immune effectors after vaccination against viral pathogens, including Ebola virus. The two-dose heterologous Ebola virus vaccine regimen, adenovirus type 26.ZEBOV followed by modified vaccinia Ankara-BN-Filo (EBOVAC2 consortium, EU Innovative Medicines Initiative), induces NK cell activation and anti-Ebola glycoprotein (GP) antibody-dependent NK cell activation post-dose 1, which is further elevated post-dose 2. Here, in a multicentre, phase 2 clinical trial (EBL2001), we demonstrate durable ex vivo NK cell activation 180 days after dose 2, with responses enriched in CD56bright NK cells. In vitro antibody-dependent responses to immobilised Ebola GP increased after dose 1, and remained elevated compared to pre-vaccination levels in serum collected 180 days later. Peak NK cell responses were observed post-dose 2 and NK cell IFN-γ responses remained significantly elevated at 180 days post-dose 2. Individual variation in NK cell responses were influenced by both anti-Ebola GP antibody concentrations and intrinsic interindividual differences in NK cell functional capacity. In summary, this study demonstrates durable NK cell responses after Ad26.ZEBOV, MVA-BN-Filo Ebola virus vaccination and could inform the immunological evaluation of future iterations of the vaccine regimen and vaccination schedules.

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

Endocrines ◽  
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.

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

Cancers ◽  
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.

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

Cancers ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 2 ◽  
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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