CD69 Deficiency Enhances the Host Response to Vaccinia Virus Infection through Altered NK Cell Homeostasis

ABSTRACTDuring the host response to viral infection, the transmembrane CD69 protein is highly upregulated in all immune cells. We have studied the role of CD69 in the murine immune response to vaccinia virus (VACV) infection, and we report that the absence of CD69 enhances protection against VACV at both short and long times postinfection in immunocompetent and immunodeficient mice. Natural killer (NK) cells were implicated in the increased infection control, since the differences were greatly diminished when NK cells were depleted. This role of NK cells was not based on an altered NK cell reactivity, since CD69 did not affect the NK cell activation threshold in response to major histocompatibility complex class I NK cell targets or protein kinase C activation. Instead, NK cell numbers were increased in the spleen and peritoneum of CD69-deficient infected mice. That was not just secondary to better infection control in CD69-deficient mice, since NK cell numbers in the spleens and the blood of uninfected CD69−/−mice were already augmented. CD69-deficient NK cells from infected mice did not have an altered proliferation capacity. However, a lower spontaneous cell death rate was observed for CD69−/−lymphocytes. Thus, our results suggest that CD69 limits the innate immune response to VACV infection at least in part through cell homeostatic survival.IMPORTANCEWe show that increased natural killer (NK) cell numbers augment the host response and survival after infection with vaccinia virus. This phenotype is found in the absence of CD69 in immunocompetent and immunodeficient hosts. As part of the innate immune system, NK lymphocytes are activated and participate in the defense against infection. Several studies have focused on the contribution of NK cells to protection against infection with vaccinia virus. In this study, it was demonstrated that the augmented early NK cell response in the absence of CD69 is responsible for the increased protection seen during infection with vaccinia virus even at late times of infection. This work indicates that the CD69 molecule may be a target of therapy to augment the response to poxvirus infection.

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Human natural killer cells: a unique innate immunoregulatory role for the CD56bright subset

Blood ◽

10.1182/blood.v97.10.3146 ◽

2001 ◽

Vol 97 (10) ◽

pp. 3146-3151 ◽

Cited By ~ 852

Author(s):

Megan A. Cooper ◽

Todd A. Fehniger ◽

Sarah C. Turner ◽

Kenneth S. Chen ◽

Bobak A. Ghaheri ◽

...

Keyword(s):

Immune Response ◽

Nk Cells ◽

Natural Killer ◽

Innate Immune Response ◽

Nk Cell ◽

Primary Source ◽

Interferon Γ ◽

Innate Immune ◽

Immunoregulatory Cytokines ◽

Human Natural Killer Cells

Abstract During the innate immune response to infection, monocyte-derived cytokines (monokines), stimulate natural killer (NK) cells to produce immunoregulatory cytokines that are important to the host's early defense. Human NK cell subsets can be distinguished by CD56 surface density expression (ie, CD56bright and CD56dim). In this report, it is shown that CD56bright NK cells produce significantly greater levels of interferon-γ, tumor necrosis factor-β, granulocyte macrophage–colony-stimulating factor, IL-10, and IL-13 protein in response to monokine stimulation than do CD56dim NK cells, which produce negligible amounts of these cytokines. Further, qualitative differences in CD56bright NK-derived cytokines are shown to be dependent on the specific monokines present. For example, the monokine IL-15 appears to be required for type 2 cytokine production by CD56bright NK cells. It is proposed that human CD56bright NK cells have a unique functional role in the innate immune response as the primary source of NK cell–derived immunoregulatory cytokines, regulated in part by differential monokine production.

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Natural Killer Cells in Immunotherapy: Are We Nearly There?

Cancers ◽

10.3390/cancers12113139 ◽

2020 ◽

Vol 12 (11) ◽

pp. 3139 ◽

Cited By ~ 1

Author(s):

Mireia Bachiller ◽

Anthony M. Battram ◽

Lorena Perez-Amill ◽

Beatriz Martín-Antonio

Keyword(s):

T Cells ◽

Nk Cells ◽

Natural Killer ◽

Cancer Patients ◽

Clinical Studies ◽

Nk Cell ◽

Innate Immune ◽

Novel Studies ◽

Cell Immunotherapy

Natural killer (NK) cells are potent anti-tumor and anti-microbial cells of our innate immune system. They are equipped with a vast array of receptors that recognize tumor cells and other pathogens. The innate immune activity of NK cells develops faster than the adaptive one performed by T cells, and studies suggest an important immunoregulatory role for each population against the other. The association, observed in acute myeloid leukemia patients receiving haploidentical killer-immunoglobulin-like-receptor-mismatched NK cells, with induction of complete remission was the determinant to begin an increasing number of clinical studies administering NK cells for the treatment of cancer patients. Unfortunately, even though transfused NK cells demonstrated safety, their observed efficacy was poor. In recent years, novel studies have emerged, combining NK cells with other immunotherapeutic agents, such as monoclonal antibodies, which might improve clinical efficacy. Moreover, genetically-modified NK cells aimed at arming NK cells with better efficacy and persistence have appeared as another option. Here, we review novel pre-clinical and clinical studies published in the last five years administering NK cells as a monotherapy and combined with other agents, and we also review chimeric antigen receptor-modified NK cells for the treatment of cancer patients. We then describe studies regarding the role of NK cells as anti-microbial effectors, as lessons that we could learn and apply in immunotherapy applications of NK cells; these studies highlight an important immunoregulatory role performed between T cells and NK cells that should be considered when designing immunotherapeutic strategies. Lastly, we highlight novel strategies that could be combined with NK cell immunotherapy to improve their targeting, activity, and persistence.

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The Role of the Cytoskeleton in Regulating the Natural Killer Cell Immune Response in Health and Disease: From Signaling Dynamics to Function

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.609532 ◽

2021 ◽

Vol 9 ◽

Author(s):

Aviad Ben-Shmuel ◽

Batel Sabag ◽

Guy Biber ◽

Mira Barda-Saad

Keyword(s):

Immune Response ◽

Nk Cells ◽

Signaling Pathways ◽

Natural Killer ◽

Immunological Synapse ◽

Nk Cell ◽

Cell Immune Response ◽

Effector Functions ◽

Health And Disease

Natural killer (NK) cells are innate lymphoid cells, which play key roles in elimination of virally infected and malignant cells. The balance between activating and inhibitory signals derived from NK surface receptors govern the NK cell immune response. The cytoskeleton facilitates most NK cell effector functions, such as motility, infiltration, conjugation with target cells, immunological synapse assembly, and cytotoxicity. Though many studies have characterized signaling pathways that promote actin reorganization in immune cells, it is not completely clear how particular cytoskeletal architectures at the immunological synapse promote effector functions, and how cytoskeletal dynamics impact downstream signaling pathways and activation. Moreover, pioneering studies employing advanced imaging techniques have only begun to uncover the architectural complexity dictating the NK cell activation threshold; it is becoming clear that a distinct organization of the cytoskeleton and signaling receptors at the NK immunological synapse plays a decisive role in activation and tolerance. Here, we review the roles of the actin cytoskeleton in NK cells. We focus on how actin dynamics impact cytolytic granule secretion, NK cell motility, and NK cell infiltration through tissues into inflammatory sites. We will also describe the additional cytoskeletal components, non-muscle Myosin II and microtubules that play pivotal roles in NK cell activity. Furthermore, special emphasis will be placed on the role of the cytoskeleton in assembly of immunological synapses, and how mutations or downregulation of cytoskeletal accessory proteins impact NK cell function in health and disease.

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Natural Killer Cells and Innate Interferon Gamma Participate in the Host Defense against Respiratory Vaccinia Virus Infection

Journal of Virology ◽

10.1128/jvi.01894-15 ◽

2015 ◽

Vol 90 (1) ◽

pp. 129-141 ◽

Cited By ~ 26

Author(s):

Georges Abboud ◽

Vikas Tahiliani ◽

Pritesh Desai ◽

Kyle Varkoly ◽

John Driver ◽

...

Keyword(s):

T Cells ◽

Immune System ◽

Respiratory Tract ◽

Vaccinia Virus ◽

Nk Cells ◽

Natural Killer ◽

Cd8 T Cells ◽

Nk Cell ◽

Innate Immune ◽

Ifn Γ

ABSTRACTIn establishing a respiratory infection, vaccinia virus (VACV) initially replicates in airway epithelial cells before spreading to secondary sites of infection, mainly the draining lymph nodes, spleen, gastrointestinal tract, and reproductive organs. We recently reported that interferon gamma (IFN-γ) produced by CD8 T cells ultimately controls this disseminated infection, but the relative contribution of IFN-γ early in infection is unknown. Investigating the role of innate immune cells, we found that the frequency of natural killer (NK) cells in the lung increased dramatically between days 1 and 4 postinfection with VACV. Lung NK cells displayed an activated cell surface phenotype and were the primary source of IFN-γ prior to the arrival of CD8 T cells. In the presence of an intact CD8 T cell compartment, depletion of NK cells resulted in increased lung viral load at the time of peak disease severity but had no effect on eventual viral clearance, disease symptoms, or survival. In sharp contrast, RAG−/−mice devoid of T cells failed to control VACV and succumbed to infection despite a marked increase in NK cells in the lung. Supporting an innate immune role for NK cell-derived IFN-γ, we found that NK cell-depleted or IFN-γ-depleted RAG−/−mice displayed increased lung VACV titers and dissemination to ovaries and a significantly shorter mean time to death compared to untreated NK cell-competent RAG−/−controls. Together, these findings demonstrate a role for IFN-γ in aspects of both the innate and adaptive immune response to VACV and highlight the importance of NK cells in T cell-independent control of VACV in the respiratory tract.IMPORTANCEHerein, we provide the first systematic evaluation of natural killer (NK) cell function in the lung after infection with vaccinia virus, a member of thePoxviridaefamily. The respiratory tract is an important mucosal site for entry of many human pathogens, including poxviruses, but precisely how our immune system defends the lung against these invaders remains unclear. Natural killer cells are a type of cytotoxic lymphocyte and part of our innate immune system. In recent years, NK cells have received increasing levels of attention following the discovery that different tissues contain specific subsets of NK cells with distinctive phenotypes and function. They are abundant in the lung, but their role in defense against respiratory viruses is poorly understood. What this study demonstrates is that NK cells are recruited, activated, and contribute to protection of the lung during a severe respiratory infection with vaccinia virus.

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Natural Killer Cells and Anti-Cancer Therapies: Reciprocal Effects on Immune Function and Therapeutic Response

Cancers ◽

10.3390/cancers13040711 ◽

2021 ◽

Vol 13 (4) ◽

pp. 711

Author(s):

Elisa C. Toffoli ◽

Abdolkarim Sheikhi ◽

Yannick D. Höppner ◽

Pita de Kok ◽

Mahsa Yazdanpanah-Samani ◽

...

Keyword(s):

Nk Cells ◽

Natural Killer ◽

Cell Function ◽

Nk Cell ◽

Innate Immune ◽

Reciprocal Effects ◽

Cancer Therapies ◽

Anti Cancer ◽

The Impact

Natural Killer (NK) cells are innate immune cells with the unique ability to recognize and kill virus-infected and cancer cells without prior immune sensitization. Due to their expression of the Fc receptor CD16, effector NK cells can kill tumor cells through antibody-dependent cytotoxicity, making them relevant players in antibody-based cancer therapies. The role of NK cells in other approved and experimental anti-cancer therapies is more elusive. Here, we review the possible role of NK cells in the efficacy of various anti-tumor therapies, including radiotherapy, chemotherapy, and immunotherapy, as well as the impact of these therapies on NK cell function.

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Cytokine-Induced Apoptosis of Human Natural Killer Cells Identifies a Novel Mechanism to Regulate the Innate Immune Response

Blood ◽

10.1182/blood.v89.3.910 ◽

1997 ◽

Vol 89 (3) ◽

pp. 910-918 ◽

Cited By ~ 101

Author(s):

Mary E. Ross ◽

Michael A. Caligiuri

Keyword(s):

Immune Response ◽

Nk Cells ◽

Natural Killer ◽

Innate Immune Response ◽

Cell Apoptosis ◽

Nk Cell ◽

Innate Immune ◽

Tnf Α ◽

Ifn Γ ◽

Induced Apoptosis

Abstract Interferon-γ (IFN-γ) is critical for an effective innate immune response against infection. A combination of interleukins (ILs) derived from activated T cells (IL-2) and monocytes (IL-12), or monocytes alone (IL-15 and IL-12), induces optimal production of IFN-γ from natural killer (NK) cells. The mechanism by which human NK cells downregulate their production of IFN-γ is unknown. Here we show that the same cytokines that induce human NK cell IFN-γ production subsequently induce apoptosis of the NK cells. Fas, bcl-2, or bax do not appear to be involved in this process. The mechanism of cytokine-induced apoptosis of human NK cells appears to involve NK cell production of tumor necrosis factor-α (TNF-α). Neutralization of TNF-α or inhibition of TNF-α binding to the p80 TNF-α receptor partially inhibited apoptosis. Transforming growth factor-β, which inhibits cytokine-induced NK cell production of IFN-γ and TNF-α, also decreased cytokine-induced NK cell apoptosis. Costimulation of a CD3−CD56+ NK leukemia cell line with IL-2 and IL-12 or IL-15 and IL-12 induced apoptosis in vitro, which increased when combined with a chemotherapeutic agent. In summary, costimulation of human NK cells via the IL-2 receptor and the IL-12 receptor induces significant IFN-γ production, followed by NK cell apoptosis and a decline in IFN-γ production. Hence, cytokines that activate this innate immune response may also serve to limit it via apoptosis. This novel observation may have implications for the regulation of the innate immune response during infection, the toxicity of combination cytokine therapy, and the treatment of NK cell leukemia.

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MITF induces escape from innate immunity in melanoma

Journal of Experimental & Clinical Cancer Research ◽

10.1186/s13046-021-01916-8 ◽

2021 ◽

Vol 40 (1) ◽

Author(s):

Luis Sánchez-del-Campo ◽

Román Martí-Díaz ◽

María F. Montenegro ◽

Rebeca González-Guerrero ◽

Trinidad Hernández-Caselles ◽

...

Keyword(s):

Immune Response ◽

Immune System ◽

Nk Cells ◽

Nk Cell ◽

Luciferase Reporter ◽

Damage Repair ◽

Reporter Assays ◽

Underlying Mechanisms ◽

Nk Cytotoxicity

Abstract Background The application of immune-based therapies has revolutionized cancer treatment. Yet how the immune system responds to phenotypically heterogeneous populations within tumors is poorly understood. In melanoma, one of the major determinants of phenotypic identity is the lineage survival oncogene MITF that integrates diverse microenvironmental cues to coordinate melanoma survival, senescence bypass, differentiation, proliferation, invasion, metabolism and DNA damage repair. Whether MITF also controls the immune response is unknown. Methods By using several mouse melanoma models, we examine the potential role of MITF to modulate the anti-melanoma immune response. ChIP-seq data analysis, ChIP-qPCR, CRISPR-Cas9 genome editing, and luciferase reporter assays were utilized to identify ADAM10 as a direct MITF target gene. Western blotting, confocal microscopy, flow cytometry, and natural killer (NK) cytotoxicity assays were used to determine the underlying mechanisms by which MITF-driven phenotypic plasticity modulates melanoma NK cell-mediated killing. Results Here we show that MITF regulates expression of ADAM10, a key sheddase that cleaves the MICA/B family of ligands for NK cells. By controlling melanoma recognition by NK-cells MITF thereby controls the melanoma response to the innate immune system. Consequently, while melanoma MITFLow cells can be effectively suppressed by NK-mediated killing, MITF-expressing cells escape NK cell surveillance. Conclusion Our results reveal how modulation of MITF activity can impact the anti-melanoma immune response with implications for the application of anti-melanoma immunotherapies.

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α-Pinene Enhances the Anticancer Activity of Natural Killer Cells via ERK/AKT Pathway

International Journal of Molecular Sciences ◽

10.3390/ijms22020656 ◽

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.

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Natural Killer Cells: Potential Biomarkers and Therapeutic Target in Autoimmune Diseases?

Frontiers in Immunology ◽

10.3389/fimmu.2021.616853 ◽

2021 ◽

Vol 12 ◽

Author(s):

Elena Gianchecchi ◽

Domenico V. Delfino ◽

Alessandra Fierabracci

Keyword(s):

Systemic Sclerosis ◽

Autoimmune Diseases ◽

Cytotoxic Activity ◽

Nk Cells ◽

Natural Killer ◽

T Cell Activation ◽

Cell Activation ◽

Nk Cell ◽

Killer Cell

Autoimmune diseases recognize a multifactorial pathogenesis, although the exact mechanism responsible for their onset remains to be fully elucidated. Over the past few years, the role of natural killer (NK) cells in shaping immune responses has been highlighted even though their involvement is profoundly linked to the subpopulation involved and to the site where such interaction takes place. The aberrant number and functionality of NK cells have been reported in several different autoimmune disorders. In the present review, we report the most recent findings regarding the involvement of NK cells in both systemic and organ-specific autoimmune diseases, including type 1 diabetes (T1D), primary biliary cholangitis (PBC), systemic sclerosis, systemic lupus erythematosus (SLE), primary Sjögren syndrome, rheumatoid arthritis, and multiple sclerosis. In T1D, innate inflammation induces NK cell activation, disrupting the Treg function. In addition, certain genetic variants identified as risk factors for T1D influenced the activation of NK cells promoting their cytotoxic activity. The role of NK cells has also been demonstrated in the pathogenesis of PBC mediating direct or indirect biliary epithelial cell destruction. NK cell frequency and number were enhanced in both the peripheral blood and the liver of patients and associated with increased NK cell cytotoxic activity and perforin expression levels. NK cells were also involved in the perpetuation of disease through autoreactive CD4 T cell activation in the presence of antigen-presenting cells. In systemic sclerosis (SSc), in addition to phenotypic abnormalities, patients presented a reduction in CD56hi NK-cells. Moreover, NK cells presented a deficient killing activity. The influence of the activating and inhibitory killer cell immunoglobulin-like receptors (KIRs) has been investigated in SSc and SLE susceptibility. Furthermore, autoantibodies to KIRs have been identified in different systemic autoimmune conditions. Because of its role in modulating the immune-mediated pathology, NK subpopulation could represent a potential marker for disease activity and target for therapeutic intervention.

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T-BET and EOMES Accelerate and Enhance Functional Differentiation of Human Natural Killer Cells

Frontiers in Immunology ◽

10.3389/fimmu.2021.732511 ◽

2021 ◽

Vol 12 ◽

Author(s):

Laura Kiekens ◽

Wouter Van Loocke ◽

Sylvie Taveirne ◽

Sigrid Wahlen ◽

Eva Persyn ◽

...

Keyword(s):

Nk Cells ◽

Natural Killer ◽

Cell Biology ◽

Nk Cell ◽

Current Knowledge ◽

Functional Differentiation ◽

Cell Maturation ◽

Hematopoietic Stem ◽

And Function

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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