scholarly journals Deciphering the Immunological Phenomenon of Adaptive Natural Killer (NK) Cells and Cytomegalovirus (CMV)

2020 ◽  
Vol 21 (22) ◽  
pp. 8864
Author(s):  
Samantha Barnes ◽  
Ophelia Schilizzi ◽  
Katherine M. Audsley ◽  
Hannah V. Newnes ◽  
Bree Foley

Natural killer (NK) cells play a significant and vital role in the first line of defense against infection through their ability to target cells without prior sensitization. They also contribute significantly to the activation and recruitment of both innate and adaptive immune cells through the production of a range of cytokines and chemokines. In the context of cytomegalovirus (CMV) infection, NK cells and CMV have co-evolved side by side to employ several mechanisms to evade one another. However, during this co-evolution the discovery of a subset of long-lived NK cells with enhanced effector potential, increased antibody-dependent responses and the potential to mediate immune memory has revolutionized the field of NK cell biology. The ability of a virus to imprint on the NK cell receptor repertoire resulting in the expansion of diverse, highly functional NK cells to this day remains a significant immunological phenomenon that only occurs in the context of CMV. Here we review our current understanding of the development of these NK cells, commonly referred to as adaptive NK cells and their current role in transplantation, infection, vaccination and cancer immunotherapy to decipher the complex role of CMV in dictating NK cell functional fate.

1994 ◽  
Vol 180 (2) ◽  
pp. 537-543 ◽  
Author(s):  
V Litwin ◽  
J Gumperz ◽  
P Parham ◽  
J H Phillips ◽  
L L Lanier

Natural killer (NK) cells kill normal and transformed hematopoietic cells that lack expression of major histocompatibility complex (MHC) class I antigens. Lysis of HLA-negative Epstein Barr virus-transformed B lymphoblastoid cell lines (B-LCL) by human NK cell clones can be inhibited by transfection of the target cells with certain HLA-A, -B, or -C alleles. NK cell clones established from an individual demonstrate clonal heterogeneity in HLA recognition and a single NK clone can recognize multiple alleles. We describe a potential human NK cell receptor (NKB1) for certain HLA-B alleles (e.g., HLA-B*5101 and-B*5801) identified by the mAb DX9. NKB1 is a 70-kD glycoprotein that is expressed on a subset of NK cells and NK cell clones. DX9 monoclonal antibody (mAb) specifically inhibits the interaction between NK cell clones and B-LCL targets transfected with certain HLA-B alleles, but does not affect recognition of HLA-A or HLA-C antigens. An individual NK cell clone can independently recognize B-LCL targets transfected with HLA-B or HLA-C antigens; however, DX9 mAb only affects interaction with transfectants expressing certain HLA-B alleles. These findings demonstrate the existence of NK cell receptors involved in the recognition of HLA-B and imply the presence of multiple receptors for MHC on an individual NK clone.


1996 ◽  
Vol 183 (5) ◽  
pp. 2391-2396 ◽  
Author(s):  
H Arase ◽  
N Arase ◽  
T Saito

Natural killer (NK) cells play an important role in immune response by producing interferon gamma (IFN-gamma) as well as exhibiting cytotoxic function. IFN-gamma produced by NK cells has been suggested to be involved in differentiation of T helper cells. On the other hand, the NKR-P1 molecule was recently identified as one of the important NK cell receptors, and it recognizes certain kinds of oligosaccharides on target cells and triggers NK cells for cytotoxicity. In the present study, we found that NK cells produce great amounts of IFN-gamma upon cross-linking of the NKR-P1 molecule. In contrast, stimulation of NK cells with IL-2 induced proliferation without producing IFN-gamma. Similar to NK cells, NK1.1+ T cells also produced IFN-gamma upon NKR-P1 cross-linking. NK1.1+ T cells produced IFN-gamma but not interleukin 4 (IL-4) upon NKR-P1 cross-linking, whereas they secreted both IFN-gamma and IL-4 upon T cell receptor cross-linking. These results indicate that NKR-P1 is a receptor molecule on NK and NK1.1+ T cells that induces not only cytotoxicity but also IFN-gamma production. Our findings provide a new pathway for IFN-gamma production by NK and NK1.1+ T cells through NKR-P1 molecules; it may be essential for immune regulation.


2015 ◽  
Vol 90 (3) ◽  
pp. 1522-1533 ◽  
Author(s):  
K. Grauwet ◽  
M. Vitale ◽  
S. De Pelsmaeker ◽  
T. Jacob ◽  
K. Laval ◽  
...  

ABSTRACTSeveral reports have indicated that natural killer (NK) cells are of particular importance in the innate response against herpesvirus infections. As a consequence, herpesviruses have developed diverse mechanisms for evading NK cells, although few such mechanisms have been identified for the largest herpesvirus subfamily, the alphaherpesviruses. The antiviral activity of NK cells is regulated by a complex array of interactions between activating/inhibitory receptors on the NK cell surface and the corresponding ligands on the surfaces of virus-infected cells. Here we report that the US3 protein kinase of the alphaherpesvirus pseudorabies virus (PRV) displays previously uncharacterized immune evasion properties: it triggers the binding of the inhibitory NK cell receptor CD300a to the surface of the infected cell, thereby providing increased CD300a-mediated protection of infected cells against NK cell-mediated lysis. US3-mediated CD300a binding was found to depend on aminophospholipid ligands of CD300a and on group I p21-activated kinases. These data identify a novel alphaherpesvirus strategy for evading NK cells and demonstrate, for the first time, a role for CD300a in regulating NK cell activity upon contact with virus-infected target cells.IMPORTANCEHerpesviruses have developed fascinating mechanisms to evade elimination by key elements of the host immune system, contributing to their ability to cause lifelong infections with recurrent reactivation events. Natural killer (NK) cells are central in the innate antiviral response. Here we report that the US3 protein kinase of the alphaherpesvirus pseudorabies virus displays a previously uncharacterized capacity for evasion of NK cells. Expression of US3 protects infected cells from NK cell-mediated lysis via increased binding of the inhibitory NK cell receptor CD300a. We show that this US3-mediated increase in CD300a binding depends on aminophospholipids and on cellular p21-activated kinases (PAKs). The identification of this novel NK cell evasion strategy may contribute to the design of improved herpesvirus vaccines and may also have significance for other PAK- and CD300a-modulating viruses and cancer cells.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 357-357 ◽  
Author(s):  
Ryan P Sullivan ◽  
Jeffrey W Leong ◽  
Stephanie E Schneider ◽  
Catherine R Keppel ◽  
Elizabeth Germino ◽  
...  

Abstract Abstract 357 NK cells are innate immune lymphocytes important for early host defense against infectious pathogens and malignant transformation. MicroRNAs (miRNAs) are small regulatory RNAs that control a wide variety of cellular processes by specific targeting of mRNA 3'UTRs. The Dicer1 gene encodes a conserved enzyme essential for miRNA processing, and Dicer1 deficiency leads to a global defect in miRNA biogenesis. While miRNA expression and regulation of adaptive T and B lymphocytes are well established, their role in the regulation of NK cell biology remains unclear. We postulated that miRNAs serve an essential role in orchestrating NK cell development and activation. To test this hypothesis, we combined lymphocyte-restricted hCD2-Cre transgenic, Rosa26-YFP-Cre-reporter, and Dicer1 ‘floxed' mice. In this model, 25–50% of Dicer1 wt/wt NK cells are YFP+ marking expression of Cre. As expected, YFP+ NK cells from Dicer1 fl/fl and fl/wt mice were confirmed to excise Dicer1, and exhibit decreased total miRNA content based on Nanostring profiling and real-time qPCR (Dicer1 fl/fl: P<0.001, fl/wt: P<0.01). MiRNA-deficient Dicer1 fl/fl mice exhibited reduced YFP+ NK percentages (spleen Dicer1 fl/fl: 14±4%, fl/wt: 35±7%, wt/wt 36±7%, P<0.001) as well as reduced absolute numbers of YFP+ NK cells [spleen Dicer1 fl/fl: 3.4±0.6×10E5, fl/wt: 6.3±1.7×10E5, wt/wt 6.1±.99×10E5, P<0.01]. In addition, Dicer1 fl/fl mice had reductions NK cell precursors in the BM (stage 2–3 NK precursors mean decrease 70±14% in Dicer1 fl/fl compared to wt/wt, P <0.01). Further, Dicer1 fl/fl NK cells exhibited reduced survival ex vivo when cultured in medium (P<0.01), low dose- (P<0.01), or high dose-IL-15 (P<0.01). These data collectively indicate that Dicer1-dependent miRNAs regulate NK cell development and homeostasis, and the net effect of miRNA loss is impaired NK development and/or survival. However, in our model Dicer1-deficient mature NK cells exhibited enhanced functionality; a finding that contrasts to less NK selective miRNA-deficient NK cell models (Bezman et al. J Immunol 185:3835, 2010). Degranulation (CD107a+, a surrogate for cytotoxicity) was enhanced in vitro in response to YAC-1 tumor target cells (P<0.05) and activating NK cell receptor ligation (P<0.001). This was unlikely due to alteration in activating NK cell receptor expression since the surface density of NKG2D and NKp46 were not affected by miRNA deficiency. Moreover, interferon-gamma (IFN-γ) production was enhanced in vitro in miRNA-deficient NK cells in response to IL-12+IL-15 (P<0.01), YAC-1 tumor target cells (P<0.01), and activating NK cell receptor ligation (P<0.001). Further, evaluation of NK cells 36 hours after infection with MCMV resulted in significantly increased IFN-γ production (% NK YFP+IFN-γ+) in Dicer1 fl/fl (64± 4.9%) vs. fl/wt (52±11%, p <0.01) or vs. wt/wt (41±6%, p <0.001) in vivo. MiRs-15/16 were identified as abundant miRNAs in NK cells that had reduced expression in Dicer1 fl/fl NK cells, and are predicted to target the murine IFN-γ 3'UTR. This targeting was validated in vitro, by transfecting 293T cells with miRNA-15/16 or control over-expression vectors and a sensor plasmid that places luciferase under the control of the murine IFN-γ 3'UTR (34% decrease, P<0.01). Moreover, the targeting was direct, since miR-15/16 targeting of IFN-γ was abrogated after mutation of two predicted binding sites in the IFN-γ 3'UTR. These data indicated that miR-15/16 may regulate IFN-γ translation by resting NK cells. Thus, our study suggests that the function of miRNAs in NK cell biology is complex, with an important role in NK cell development, survival and/or homeostasis, while tempering peripheral NK cell activation. Further study of individual miRNAs in an NK cell specific fashion will provide insight into these complex miRNA regulatory effects in NK cell development/survival and effector function. Disclosures: No relevant conflicts of interest to declare.


Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1420
Author(s):  
Jagoda Siemaszko ◽  
Aleksandra Marzec-Przyszlak ◽  
Katarzyna Bogunia-Kubik

Natural Killer (NK) cells are natural cytotoxic, effector cells of the innate immune system. They can recognize transformed or infected cells. NK cells are armed with a set of activating and inhibitory receptors which are able to bind to their ligands on target cells. The right balance between expression and activation of those receptors is fundamental for the proper functionality of NK cells. One of the best known activating receptors is NKG2D, a member of the CD94/NKG2 family. Due to a specific NKG2D binding with its eight different ligands, which are overexpressed in transformed, infected and stressed cells, NK cells are able to recognize and attack their targets. The NKG2D receptor has an enormous significance in various, autoimmune diseases, viral and bacterial infections as well as for transplantation outcomes and complications. This review focuses on the NKG2D receptor, the mechanism of its action, clinical relevance of its gene polymorphisms and a potential application in various clinical settings.


Blood ◽  
2004 ◽  
Vol 104 (9) ◽  
pp. 2858-2866 ◽  
Author(s):  
Yanmei Han ◽  
Minghui Zhang ◽  
Nan Li ◽  
Taoyong Chen ◽  
Yi Zhang ◽  
...  

Abstract Natural killer (NK) cell inhibitory receptors play important roles in the regulation of target susceptibility to natural killing. Here, we report the molecular cloning and functional characterization of a novel NK cell receptor, KLRL1, from human and mouse dendritic cells. KLRL1 is a type II transmembrane protein with an immunoreceptor tyrosine-based inhibitory motif and a C-type lectinlike domain. The KLRL1 gene is located in the central region of the NK gene complex in both humans and mice, on human chromosome 12p13 and mouse chromosome 6F3, adjacent to the other KLR genes. KLRL1 is preferentially expressed in lymphoid tissues and immune cells, including NK cells, T cells, dendritic cells, and monocytes or macrophages. Western blot and fluorescence confocal microscopy analyses indicated that KLRL1 is a membrane-associated glycoprotein, which forms a heterodimer with an as yet unidentified partner. Human and mouse KLRL1 are both predicted to contain putative immunoreceptor tyrosine-based inhibitory motifs (ITIMs), and immunoprecipitation experiments demonstrated that KLRL1 associates with the tyrosine phosphatases SHP-1 (SH2-domain-containing protein tyrosine phosphatase 1) and SHP-2. Consistent with its potential inhibitory function, pretreatment of target cells with human KLRL1-Fc fusion protein enhances NK-mediated cytotoxicity. Taken together, our results demonstrate that KLRL1 belongs to the KLR family and is a novel inhibitory NK cell receptor.


Cancers ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 2 ◽  
Author(s):  
Marisa Market ◽  
Katherine Baxter ◽  
Leonard Angka ◽  
Michael Kennedy ◽  
Rebecca Auer

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.


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Corona Solana ◽  
Raquel Tarazona ◽  
Rafael Solana

Alzheimer’s disease (AD) represents the most common cause of dementia in the elderly. AD is a neurodegenerative disorder characterized by progressive memory loss and cognitive decline. Although the aetiology of AD is not clear, both environmental factors and heritable predisposition may contribute to disease occurrence. In addition, inflammation and immune system alterations have been linked to AD. The prevailing hypothesis as cause of AD is the deposition in the brain of amyloid beta peptides (Aβ). Although Aβ have a role in defending the brain against infections, their accumulation promotes an inflammatory response mediated by microglia and astrocytes. The production of proinflammatory cytokines and other inflammatory mediators such as prostaglandins and complement factors favours the recruitment of peripheral immune cells further promoting neuroinflammation. Age-related inflammation and chronic infection with herpes virus such as cytomegalovirus may also contribute to inflammation in AD patients. Natural killer (NK) cells are innate lymphoid cells involved in host defence against viral infections and tumours. Once activated NK cells secrete cytokines such as IFN-γ and TNF-α and chemokines and exert cytotoxic activity against target cells. In the elderly, changes in NK cell compartment have been described which may contribute to the lower capacity of elderly individuals to respond to pathogens and tumours. Recently, the role of NK cells in the immunopathogenesis of AD is discussed. Although in AD patients the frequency of NK cells is not affected, a high NK cell response to cytokines has been described together with NK cell dysregulation of signalling pathways which is in part involved in this altered behaviour.


2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A938-A938
Author(s):  
Chiara Zambarda ◽  
Karolin Guldevall ◽  
Chiara Zambarda ◽  
Karolin Guldevall ◽  
Christian Breunig ◽  
...  

BackgroundThe use of bispecific natural killer (NK) cell engagers has emerged as a successful strategy for immune cell activation and killing of tumor cells through antibody-dependent cellular cytotoxicity (ADCC). Among these, tetravalent, bispecific innate cell engagers (ICE®) with specificity for the activating receptor CD16A selectively triggering innate responses from NK cells or macrophages represent the most clinically advanced concept. The CD30/CD16A specific ICE® AFM13, has shown efficacy in patients with CD30+ lymphomas as monotherapy1 and combination therapy with check-point inhibitors2 and most recently in combination with adoptive NK cell therapy.3 The EGFR/CD16A specific ICE® AFM24, targeting a variety of solid tumors like colorectal, or lung cancer with a unique mode of action independent of EGFR signaling inhibition, is currently evaluated in an ongoing Ph1/2a clinical study.MethodsWe used a microchip-based screening with single cell resolution4 to elucidate the dynamic responses of individual NK cells towards tumor target cells upon treatment with AFM13 or AFM24.ResultsWe found that AFM13 and AFM24 mediated potent activation of NK cells, leading to increased responsive cytotoxic NK cells and significantly increased the number of NK cells that exerted engagement with multiple target cells rendering these NK cells serial killers. Strikingly, bispecific ICE® molecules triggered stronger cytotoxic responses compared to monoclonal antibodies. One suggested strategy to boost killing by NK cells is to use molecular inhibitors or protein constructs that prevent shedding of CD16.5 However, previous results have shown that this can lead to impaired detachment from target cells, reducing the capacity for an individual NK cell to form serial contacts to target cells.6 We observed that the elevated NK cell killing induced by ICE® molecules was largely conserved when cells were treated with the shedding inhibitor Batimastat. Analysis of the functional dynamics of NK cells revealed that inhibition of CD16 shedding prevented NK cell detachment from target cells, resulting in cell cluster formation. This might strongly impact targeting of distant tumor cells by an individual NK cell thus limiting its anti-tumoral activity.ConclusionsIn conclusion, we show that both AFM13 and AFM24 increase the fraction of tumor-target responsive NK cells and boost serial killing of target cells by individual NK cells. Based on these data, ICE® molecules can be characterized as potent anti-tumoral agents leveraging the enormous potential of NK cells while maintaining crucial features of NK cell biology.AcknowledgementsWe thank members of the Önfelt lab for their valuable help and feedback.ReferencesSawas A, Elgedawe H, Vlad G, Lipschitz M, Chen P-H, Rodig SJ, et al. Clinical and biological evaluation of the novel CD30/CD16A tetravalent bispecific antibody (AFM13) in relapsed or refractory CD30-positive lymphoma with cutaneous presentation: a biomarker phase Ib/IIa study (NCT03192202). Blood 2018;132(Supplement 1):2908–2908.Bartlett NL, Herrera AF, Domingo-Domenech E, Mehta A, Forero-Torres A, Garcia-Sanz R, et al. A phase 1b study of AFM13 in combination with pembrolizumab in patients with relapsed or refractory Hodgkin lymphoma. Blood 2020. Blood 2020;136(21):2401–2409.Kerbauy LN, Marin ND, Kaplan M, Banerjee PP, Berrien-Elliott MM, Becker-Hapak M, et al. Combining AFM13, a bispecific CD30/CD16 antibody, with cytokine-activated blood and cord blood–derived NK cells facilitates CAR-like responses against CD30 + malignancies. Clin Cancer Res Epub 2021.Guldevall K, Brandt L, Forslund E, Olofsson K, Frisk TW, Olofsson PE, et al. Microchip screening platform for single cell assessment of NK cell cytotoxicity. Front Immunol 2016;7:119.Romee R, Foley B, Lenvik T, Wang Y, Zhang B, Ankarlo D, et al. NK cell CD16 surface expression and function is regulated by a disintegrin and metalloprotease-17 (ADAM17). Blood 2013;121(18):3599–608.Srpan K, Ambrose A, Karampatzakis A, Saeed M, Cartwright ANR, Guldevall K, et al. Shedding of CD16 disassembles the NK cell immune synapse and boosts serial engagement of target cells. J Cell Biol 2018;217(9):3267–83.Ethics ApprovalThis work was performed with NK cells from healthy anonymous blood donors, which requires no ethical permit according to local regulations.


2021 ◽  
Vol 12 ◽  
Author(s):  
Laura Kiekens ◽  
Wouter Van Loocke ◽  
Sylvie Taveirne ◽  
Sigrid Wahlen ◽  
Eva Persyn ◽  
...  

T-bet and Eomes are transcription factors that are known to be important in maturation and function of murine natural killer (NK) cells. Reduced T-BET and EOMES expression results in dysfunctional NK cells and failure to control tumor growth. In contrast to mice, the current knowledge on the role of T-BET and EOMES in human NK cells is rudimentary. Here, we ectopically expressed either T-BET or EOMES in human hematopoietic progenitor cells. Combined transcriptome, chromatin accessibility and protein expression analyses revealed that T-BET or EOMES epigenetically represses hematopoietic stem cell quiescence and non-NK lineage differentiation genes, while activating an NK cell-specific transcriptome and thereby drastically accelerating NK cell differentiation. In this model, the effects of T-BET and EOMES are largely overlapping, yet EOMES shows a superior role in early NK cell maturation and induces faster NK receptor and enhanced CD16 expression. T-BET particularly controls transcription of terminal maturation markers and epigenetically controls strong induction of KIR expression. Finally, NK cells generated upon T-BET or EOMES overexpression display improved functionality, including increased IFN-γ production and killing, and especially EOMES overexpression NK cells have enhanced antibody-dependent cellular cytotoxicity. Our findings reveal novel insights on the regulatory role of T-BET and EOMES in human NK cell maturation and function, which is essential to further understand human NK cell biology and to optimize adoptive NK cell therapies.


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