scholarly journals Triggering through CD16 or phorbol esters enhances adhesion of NK cells to laminin via very late antigen 6.

1992 ◽  
Vol 176 (5) ◽  
pp. 1251-1257 ◽  
Author(s):  
A Gismondi ◽  
F Mainiero ◽  
S Morrone ◽  
G Palmieri ◽  
M Piccoli ◽  
...  
Keyword(s):  
Immune Response ◽  
Cell Migration ◽  
Nk Cells ◽  
Biochemical Analysis ◽  
Phorbol Esters ◽  
Nk Cell ◽  
Receptor Expression ◽  
Binding Assays ◽  
Binding Domains ◽  
Late Antigen

Very late antigens VLA-1, VLA-2, VLA-3, and VLA-6, belonging to the beta 1 subfamily of integrins, have been identified as receptors for different binding domains of laminin (LM). We have detected VLA-6, but not VLA-1 and VLA-2 on a subset (50-70%) of fresh peripheral blood CD3-, CD16+, CD56+ human natural killer (NK) cells by immunofluorimetric and biochemical analysis. Binding assays performed on LM-coated plates showed that 10-15% of NK cells spontaneously adhere to LM, and this adhesion is mediated by VLA-6. Activation of NK cells through CD16 triggering or by phorbol ester results in a rapid increase of adhesion to LM, which is still mediated by VLA-6. The enhanced adhesiveness is not associated with changes in beta 1 LM receptor expression, while it correlates with changes in the phosphorylation status of alpha 6 subunit. The expression of VLA-6 on NK cells and the modulation of its avidity by activating stimuli may be relevant for NK cell migration and tissue location during inflammation or immune response.

scholarly journals Natural Killer Cell Subpopulations and Inhibitory Receptor Dynamics in Myelodysplastic Syndromes and Acute Myeloid Leukemia

2021 ◽  
Vol 12 ◽  
Author(s):  
Vlad Andrei Cianga ◽  
Lydia Campos Catafal ◽  
Petru Cianga ◽  
Mariana Pavel Tanasa ◽  
Mohamad Cherry ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Immune Response ◽  
Nk Cells ◽  
Natural Killer ◽  
Nk Cell ◽  
Expression Patterns ◽  
Receptor Expression ◽  
Cell Maturation ◽  
Target Cells ◽  
Cell Subpopulations

Natural killer (NK) cells are key innate immunity effectors that play a major role in malignant cell destruction. Based on expression patterns of CD16, CD56, CD57, and CD94, three distinct NK cell maturation stages have been described, which differ in terms of cytokine secretion, tissue migration, and the ability to kill target cells. Our study addressed NK cell maturation in bone marrow under three conditions: a normal developmental environment, during pre-leukemic state (myelodysplastic syndrome, MDS), and during leukemic transformation (acute myeloblastic leukemia, AML). In this study, we used a new tool to perform multicolor flow cytometry data analysis, based on principal component analysis, which allowed the unsupervised, accurate discrimination of immature, mature, and hypermature NK subpopulations. An impaired NK/T cell distribution was observed in the MDS bone marrow microenvironment compared with the normal and AML settings, and a phenotypic shift from the mature to the immature state was observed in NK cells under both the MDS and AML conditions. Furthermore, an impaired NK cell antitumor response, resulting in changes in NK cell receptor expression (CD159a, CD158a, CD158b, and CD158e1), was observed under MDS and AML conditions compared with the normal condition. The results of this study provide evidence for the failure of this arm of the immune response during the pathogenesis of myeloid malignancies. NK cell subpopulations display a heterogeneous and discordant dynamic on the spectrum between normal and pathological conditions. MDS does not appear to be a simple, intermediate stage but rather serves as a decisive step for the mounting of an efficient or ineffective immune response, leading to either the removal of the tumor cells or to malignancy.

scholarly journals Phenotypic and functional changes of NK cells in patients with myelodysplastic syndrome and acute myeloid leukemia treated with hypomethylating drugs

2021 ◽  
Vol 23 (2) ◽  
pp. 223-230
Author(s):  
D. I. Zhigarev ◽  
M. V. Khoreva ◽  
L. V. Gankovskaya
Keyword(s):  
Immune Response ◽  
Acute Myeloid Leukemia ◽  
Myelodysplastic Syndrome ◽  
Nk Cells ◽  
Critical Analysis ◽  
Myeloid Leukemia ◽  
Nk Cell ◽  
Receptor Expression ◽  
Functional Characteristics ◽  
Acute Myeloid

Natural killer cells (NK cells) are cytotoxic lymphocytes that play a pivotal role in maintaining immunological surveillance and in developing an innate immune response. Since the discovery of NK cells in 1973, the mechanisms of their functioning have been studied in details, and there is currently no doubt that they play a special role in the process of recognition and destruction of transformed and malignant cells. Understanding the role of NK cells in antitumor immunity, on the one hand, leads to emergence of new immunotherapeutic strategies and, on the other hand, allows to adjust the existing treatment regimens for tumor diseases, in accordance with the principle of primum non nocere. Optimization of cancer therapy protocols executed in order to protect immune cells from death and functional impairment is an important problem that cannot be successfully resolved without regular aggregation of the results from disparate studies and critical analysis of the all accumulated data.The objective of this review is to create a relevant and holistic picture of changes in the phenotypic and functional characteristics of NK cells in patients with two related hematological diseases – myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). For the treatment of both illnesses, drugs from the group of hypomethylating agents are used, the acting mechanism of which, unlike classical cytostatic agents, is based on modulation of the tumor cell genes expression. All the cells of the body are being affected, including NK cells, since these drugs act nonspecifically. Such an interaction leads to a hypomethylation of NK cell DNA and changes the expression of functional receptors, which, in turn, provide the development of antitumor NK cell immune response.Of course, just the fact of changing gene expression in certain cells does not allow us to fully judge the drug’s impact on the state of immune system. Meanwhile, the origin of this change and its role are important in the context of the disease pathogenesis. Ultimately, a simple description of an increase or decrease in a single receptor expression is not illustrative, since it can lead to uncertain consequences. For this reason, the current review, in addition to describing the existing data on the changes of NK cell receptors expression under the influence of hypomethylating drugs, gives a special attention to critical analysis of functional characteristics of NK cells, including their cytotoxic activity aimed at malignant blast cells, being a determinant of clinical course in the described diseases. 

scholarly journals Innate-like Chemokine Receptor Profile and Migratory Behaviour By Terminally Differentiated and Educated NK Cells

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 24-25
Author(s):  
Mieszko Lachota ◽  
Daniel Alfredo Palacios ◽  
Dennis Clement ◽  
Eivind Heggernes Ask ◽  
Hanna Julie Hoel ◽  
...  
Keyword(s):  
Immune Response ◽  
Cell Differentiation ◽  
Nk Cells ◽  
Chemokine Receptor ◽  
Nk Cell ◽  
Receptor Expression ◽  
Migratory Behavior ◽  
Chemokine Receptor Expression ◽  
Receptor Profile ◽  
Nk Cell Differentiation

Natural Killer (NK) cells play an essential role in cancer surveillance and have a unique capability of spontaneous cytotoxicity against cancer cells. The human NK cell repertoire is functionally diversified through a tightly regulated differentiation process characterized by an early transition from CD56bright to CD56dim NK cells, followed by coordinated changes in expression of inhibitory receptors, including NKG2A and killer cell immunoglobulin-like receptors (KIR). The acquisition of self HLA class I binding KIRs during NK cell differentiation tunes the cytotoxic potential of NK cells in a process termed education, characterized by increased loading of granzyme B in dense core granules. Although NK cell differentiation and education are critical determinants of the functional potential of the cell, little is known about how these events shape the migratory behavior of NK cells. To mediate appropriate and directed immune response against cancer, NK cells must be capable of migration to the tumor site. This process is mediated by chemokines, which guide cell migration by binding to their specific receptors. For example, in multiple myeloma, CXCR3 and CCR5 ligands (MIG, IP-10, and MIP-1a) are significantly upregulated in the bone marrow compared to healthy controls, affecting the composition of immune cells in the tumor microenvironment. In order to delineate the homing patterns of distinct NK cell subsets, we used high-dimensional flow cytometry combined with functional assays to map the NK cell chemokine receptor expression and migratory behavior. We screened resting and cytokine/feeder cell stimulated peripheral blood NK cells for the expression of a panel of 20 chemokine receptors (A). Based on CD56, CD57, NKG2A, and KIR expression, NK cells were divided into 6 phenotypically and functionally distinct subsets that were ordered according to their differentiation status (B). We found that the expression of CX3CR1, CXCR1, CXCR2, and CMKLR1 gradually increased during differentiation, whereas the expression of CXCR3, CCR7, and CCR5 was lower in more differentiated NK cells. CXCR4, CCR4, and CCR2 expression was relatively uniform across all subsets. Interestingly, CCR1 and CXCR6 were expressed mainly on less differentiated NKG2A+ CD56dim NK cells (B). Next, we stratified the chemokine receptor expression on mature KIR+ NK cells based on the expression of self (educated) or non-self KIR (uneducated). Educated NK cells expressed CXCR1, CX3CR1, CCR5, and CMKLR1 at higher levels than the uneducated NK cells. Conversely, CXCR3 was expressed at lower levels on educated NK cells (C). No difference was observed for CXCR2 expression. To determine whether the observed differences in chemokine receptor expression translate into altered chemokine responsiveness between the subsets, we combined the transwell system with multicolor flow cytometry. We found that the chemokine-induced migration capability of NK cells correlated closely with the expression level of corresponding chemokine receptor, leading to subset specific responses to various chemokine gradients (D). The present results show that peripheral blood NK cell chemokine receptor profile changes in a coordinated fashion during NK cell differentiation and is further influenced by the expression of self-specific KIR. Interestingly, receptors which expression declines during NK cell differentiation (CCR5, CCR7, and CXCR3) are commonly associated with adaptive T cell responses to viruses, whereas receptors that are upregulated along the differentiation axis (CXCR1, CXCR2, CX3CR1, CMKLR1) are typical for neutrophils and macrophages as a part of the innate immune response. Thus, our results suggest that NK cell differentiation and education processes together shape the NK cell migratory capabilities to promote homing of the most functional NK cell subsets to the site of inflammation and serve as the first line of defense in the immune response to pathogens and tumors. Figure Disclosures Malmberg: Fate Therapeutics: Consultancy, Patents & Royalties; Vycellix: Membership on an entity's Board of Directors or advisory committees.

scholarly journals Direct Binding of Human NK Cell Natural Cytotoxicity Receptor NKp44 to the Surfaces of Mycobacteria and Other Bacteria

2008 ◽  
Vol 76 (4) ◽  
pp. 1719-1727 ◽  
Author(s):  
Semih Esin ◽  
Giovanna Batoni ◽  
Claudio Counoupas ◽  
Annarita Stringaro ◽  
Franca Lisa Brancatisano ◽  
...  
Keyword(s):  
Nk Cells ◽  
Nk Cell ◽  
Cell Subset ◽  
Surface Expression ◽  
Binding Assays ◽  
Igg Antibody ◽  
Direct Stimulation ◽  
Activating Receptors ◽  
Accessory Cells

ABSTRACT Our previous studies demonstrated that Mycobacterium bovis bacillus Calmette-Guérin (BCG) can directly interact with human NK cells and induce the proliferation, gamma interferon production, and cytotoxic activity of such cells without the need for accessory cells. Thus, the aim of the present study was to identify the putative receptor(s) responsible for the recognition of BCG by human NK cells and potentially involved in the activation of NK cells. To this end, we first investigated the surface expression of three NK cell-activating receptors belonging to the natural cytoxicity receptor (NCR) family on highly purified human NK cells upon in vitro direct stimulation with BCG. An induction of the surface expression of NKp44, but not of NKp30 or NKp46, was observed after 3 and 4 days of in vitro stimulation with live BCG. The NKp44 induction involved mainly a particular NK cell subset expressing the CD56 marker at high density, CD56bright. In order to establish whether NKp44 could directly bind to BCG, whole BCG cells were stained with soluble forms of the three NCRs chimeric for the human immunoglobulin G (IgG) Fc fragment (NKp30-Fc, NKp44-Fc, NKp46-Fc), followed by incubation with a phycoerythrin (PE)-conjugated goat anti-human IgG antibody. Analysis by flow cytometry of the complexes revealed a higher PE fluorescence intensity for BCG incubated with NKp44-Fc than for BCG incubated with NKp30-Fc, NKp46-Fc, or negative controls. The binding of NKp44-Fc to the BCG surface was confirmed with immunogold labeling using transmission electron microscopy, suggesting the presence of a putative ligand(s) for human NKp44 on the BCG cell wall. Similar binding assays performed on a number of gram-positive and gram-negative bacteria revealed a pattern of NKp44-Fc binding restricted to members of the genus Mycobacterium, to the mycobacterium-related species Nocardia farcinica, and to Pseudomonas aeruginosa. Altogether, the results obtained indicate, for the first time, that at least one member of the NCR family (NKp44) may be involved in the direct recognition of bacterial pathogens by human NK cells.

scholarly journals MITF induces escape from innate immunity in melanoma

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.

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

Blood ◽  
2001 ◽  
Vol 97 (10) ◽  
pp. 3146-3151 ◽  
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.

Adrenal tumors provide insight into the role of cortisol in NK cell activity

2021 ◽  
Author(s):  
Andrew E. Greenstein ◽  
Mouhammed Amir Habra ◽  
Subhagya A. Wadekar ◽  
Andreas Grauer
Keyword(s):  
Immune Response ◽  
Nk Cells ◽  
Cell Activation ◽  
Nk Cell ◽  
Phase 1 ◽  
Cell Activity ◽  
The Cancer Genome Atlas ◽  
Adrenal Tumors ◽  
Steroid Synthesis

Elevated glucocorticoid (GC) activity may limit tumor immune response and immune checkpoint inhibitor (ICI) efficacy. Adrenocortical carcinoma (ACC) provides a unique test case to assess correlates of GC activity, as approximately half of ACC patients exhibit excess GC production (GC+). ACC multi-omics were analyzed to identify molecular consequences of GC+ and assess the rationale for combining the glucocorticoid receptor (GR) antagonist relacorilant with an ICI. GC status, mRNA expression, and DNA mutation and methylation data from 71 adrenal tumors were accessed via The Cancer Genome Atlas. Expression of 858 genes differed significantly between GC- and GC+ ACC cases. KEGG pathway analysis showed higher gene expression of 3 pathways involved in steroid synthesis and secretion in GC+ cases. Fifteen pathways, most related to NK cells and other immune activity, showed lower expression. Hypomethylation was primarily observed in the steroid synthesis pathways. Tumor-infiltrating CD4+ memory (P=.003), CD8+ memory (P=.001), and NKT-cells (P=.014) were depleted in GC+ cases; tumor-associated neutrophils were enriched (P=.001). Given the pronounced differences between GC+ and GC- ACC, the effects of cortisol on NK cells were assessed in vitro (NK cells from human PBMCs stimulated with IL-2 or IL-12/15). Cortisol suppressed, and relacorilant restored, NK cell activation, proliferation, and direct tumor cell killing. Thus, GR antagonism may increase the abundance and function of NK and other immune cells in the tumor microenvironment, promoting immune response in GC+ ACC and other malignancies with GC+. This hypothesis will be tested in a phase 1 trial of relacorilant + ICI.

scholarly journals NK cell recruitment limits tissue damage during an enteric helminth infection

2019 ◽  
Vol 13 (2) ◽  
pp. 357-370 ◽  
Author(s):  
Maria E. Gentile ◽  
Yue Li ◽  
Amicha Robertson ◽  
Kathleen Shah ◽  
Ghislaine Fontes ◽  
...  
Keyword(s):  
Immune Response ◽  
Nk Cells ◽  
Helminth Infection ◽  
Nk Cell ◽  
Early Response ◽  
Cell Recruitment ◽  
Parasitic Helminths ◽  
Cxcr3 Expression ◽  
Type 2 Immune Response

AbstractParasitic helminths cause significant damage as they migrate through host tissues to complete their life cycle. While chronic helminth infections are characterized by a well-described Type 2 immune response, the early, tissue-invasive stages are not well understood. Here we investigate the immune pathways activated during the early stages of Heligmosomoides polygyrus bakeri (Hpb), a natural parasitic roundworm of mice. In contrast to the Type 2 immune response present at later stages of infection, a robust Type 1 immune signature including IFNg production was dominant at the time of parasite invasion and granuloma formation. This early response was associated with an accumulation of activated Natural Killer (NK) cells, with no increase of other innate lymphoid cell populations. Parabiosis and confocal microscopy studies indicated that NK cells were recruited from circulation to the small intestine, where they surrounded parasitic larvae. NK cell recruitment required IFNγ receptor signaling, but was independent of CXCR3 expression. The depletion of tissue-infiltrating NK cells altered neither worm burden nor parasite fitness, but increased vascular injury, suggesting a role for NK cells in mediating tissue protection. Together, these data identify an unexpected role for NK cells in promoting disease tolerance during the invasive stage of an enteric helminth infection.

scholarly journals Hitting More Birds with a Stone: Impact of TGF-β on ILC Activity in Cancer

2020 ◽  
Vol 9 (1) ◽  
pp. 143 ◽  
Author(s):  
Cinzia Fionda ◽  
Helena Stabile ◽  
Cristina Cerboni ◽  
Alessandra Soriani ◽  
Angela Gismondi ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Nk Cells ◽  
Cancer Cells ◽  
Nk Cell ◽  
Critical Role ◽  
Cell Activity ◽  
Lymphoid Cells ◽  
Receptor Expression ◽  
Nk Cell Activity ◽  
Group I

Transforming growth factor (TGF)-β is a central immunosuppressive cytokine within tumor microenvironment inhibiting the expansion and function of major cellular components of adaptive and innate immune system. Among them, compelling evidence has demonstrated that TGF-β is a key regulator of natural killer (NK) cells, innate lymphoid cells (ILCs) with a critical role in immunosurveillance against different kinds of cancer cells. A TGF-β rich tumor microenvironment blocks NK cell activity at multiple levels. This immunosuppressive factor exerts direct regulatory effects on NK cells including inhibition of cytokine production, alteration of activating/inhibitory receptor expression, and promotion of the conversion into non cytotoxic group I ILC (ILC1). Concomitantly, TGF-β can render tumor cells less susceptible to NK cell-mediated recognition and lysis. Indeed, accumulating evidence suggest that changes in levels of NKG2D ligands, mainly MICA, as well as an increase of immune checkpoint inhibitors (e.g., PD-L1) and other inhibitory ligands on cancer cells significantly contribute to TGF-β-mediated suppression of NK cell activity. Here, we will take into consideration two major mechanisms underlying the negative regulation of ILC function by TGF-β in cancer. First, we will address how TGF-β impacts the balance of signals governing NK cell activity. Second, we will review recent advances on the role of this cytokine in driving ILC plasticity in cancer. Finally, we will discuss how the development of therapeutic approaches blocking TGF-β may reverse the suppression of host immune surveillance and improve anti-tumor NK cell response in the clinic.

scholarly journals Rapid development of exhaustion and down-regulation of eomesodermin limit the antitumor activity of adoptively transferred murine natural killer cells

Blood ◽  
2012 ◽  
Vol 119 (24) ◽  
pp. 5758-5768 ◽  
Author(s):  
Saar Gill ◽  
Adrianne E. Vasey ◽  
Alysha De Souza ◽  
Jeanette Baker ◽  
Aaron T. Smith ◽  
...  
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Nk Cell ◽  
Rapid Development ◽  
Receptor Expression ◽  
Down Regulation ◽  
First Response ◽  
Control Tumor Growth ◽  
Control Tumor ◽  
Ifn Γ

Abstract Natural killer (NK) cells are potent anti-viral and antitumor “first responders” endowed with natural cytotoxicity and cytokine production capabilities. To date, attempts to translate these promising biologic functions through the adoptive transfer of NK cells for the treatment of cancer have been of limited benefit. Here we trace the fate of adoptively transferred murine NK cells and make the surprising observation that NK cells traffic to tumor sites yet fail to control tumor growth or improve survival. This dysfunction is related to a rapid down-regulation of activating receptor expression and loss of important effector functions. Loss of interferon (IFN)γ production occurs early after transfer, whereas loss of cytotoxicity progresses with homeostatic proliferation and tumor exposure. The dysfunctional phenotype is accompanied by down-regulation of the transcription factors Eomesodermin and T-bet, and can be partially reversed by the forced overexpression of Eomesodermin. These results provide the first demonstration of NK-cell exhaustion and suggest that the NK-cell first-response capability is intrinsically limited. Further, novel approaches may be required to circumvent the described dysfunctional phenotype.

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