Short-term and long-term leptin exposure differentially affect human natural killer cell immune functions

Epidemiological studies have indicated that obesity is associated with a higher risk for certain cancers caused by elevated levels of adipocyte-derived hormones. Leptin, one such hormone produced by adipocytes, is a major regulator of metabolism and has also been shown to modulate immunity. However, its role in regulating human natural killer (NK) cell functions is largely unknown. Here, we show that the leptin receptor (Ob-R) is expressed on 5% of NK cells isolated from blood donors, as measured with flow cytometry, and expression of the signal-transducing long form of the leptin receptor Ob-Rb was confirmed with quantitative PCR. The Ob-R+ subpopulation displayed a lower expression of CD16, a cell surface receptor mediating antibody-dependent activation. Short-term stimulation with leptin increased IFNγ secretion, CD69 activation marker expression, and cytotoxic lysis of tumor cells; this was mediated by an improved conjugate forming between NK cells and tumor cells as well as higher expression of tumor necrosis factor-related apoptosis-inducing ligand. On the contrary, long-term incubation with leptin significantly impaired these NK cell immune functions and decreased cell proliferation. In addition, phosphorylation of Jak-2 after leptin stimulation was reduced in peripheral mononuclear blood cells from obese humans compared with normal-weight controls. NK cells represent an immune cell population that is crucial for an effective antitumor response. Here, we show that long-term exposure to leptin, similarly to the situation in obese individuals with elevated serum leptin levels, significantly impairs integral parts of NK cell immune functions, possibly linking leptin to increased cancer susceptibility in obesity.

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799 Neoantigen-cytokine-chemokine multifunctional natural killer cell engager for immunotherapy of solid tumors

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2021-sitc2021.799 ◽

2021 ◽

Vol 9 (Suppl 3) ◽

pp. A834-A834

Author(s):

Xue Yao ◽

Sandro Matosevic

Keyword(s):

Tumor Microenvironment ◽

Cell Therapy ◽

Nk Cells ◽

Natural Killer ◽

Solid Tumors ◽

Tumor Cells ◽

Nk Cell ◽

Killer Cell ◽

Nk Cell Therapy

BackgroundThe effectiveness of natural killer (NK) cell-based immunotherapy against solid tumors is limited by the lack of specific antigens and the immunosuppressive tumor microenvironment (TME). Glioblastoma multiforme (GBM) is one such heavily immunosuppressive tumor that has been particularly hard to target and remains without a viable treatment. The development of novel approaches to enhance the efficacy of NK cells against GBM is urgently needed. NK cell engagers (NKCE) have been developed to enhance the efficacy of NK cell therapy.MethodsTo improve the clinical efficacy of NK cell therapy, we are developing a new generation of multi-specific killer engagers, which consists of a neoantigen-targeting moiety, together with cytokine and chemokine-producing domains. Neoantigens are new antigens formed specifically in tumor cells due to genome mutations, making them highly specific tools to target tumor cells. Our engager has been designed to target Wilms' tumor-1 (WT-1), a highly specific antigen overexpressed in GBM among other solid tumors. This is done through the generation of an scFv specific targeting the complex of WT-1126-134/HLA-A*02:01 on the surface of GBM. On the NK cell side, the engager is designed to target the activating receptor NKp46. Incorporation of the cytokine IL-15 within the engager supports the maturation, persistence, and expansion of NK cells in vivo while favoring their proliferation and survival in the tumor microenvironment. Additionally, our data indicated that the chemokine CXCL10 plays an important role in the infiltration of NK cells into GBM, however, GBM tumors produce low levels of this chemokine. Incorporation of a CXCL10-producing function into our engager supports intratumoral NK cell trafficking by promoting, through their synthetic production, increased levels of CXCL10 locally in the tumor microenvironment.ResultsCollectively, this has resulted in a novel multifunctional NK cell engager, combining neoantigen-cytokine-chemokine elements fused to an activating domain-specific to NK cells, and we have investigated its ability to support and enhance NK cell-mediated cytotoxicity against solid tumors in vitro and in vivo against patient-derived GBM models. The multi-specific engager shows both high tumor specificity, as well as the ability to overcome NK cell dysfunction encountered in the GBM TME.ConclusionsWe hypothesize that taking advantage of our multi-functional engager, NK cells will exhibit superior ex vivo expansion, infiltration, and antitumor activity in the treatment of GBM and other solid tumors.

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Flt3 Ligand Promotes the Generation of a Distinct CD34+Human Natural Killer Cell Progenitor That Responds to Interleukin-15

Blood ◽

10.1182/blood.v92.10.3647 ◽

1998 ◽

Vol 92 (10) ◽

pp. 3647-3657 ◽

Cited By ~ 158

Author(s):

Haixin Yu ◽

Todd A. Fehniger ◽

Pascal Fuchshuber ◽

Karl S. Thiel ◽

Eric Vivier ◽

...

Keyword(s):

Cytotoxic Activity ◽

Nk Cells ◽

Natural Killer ◽

Stromal Cells ◽

Nk Cell ◽

Cell Development ◽

Lower Percentage ◽

Human Natural Killer Cell ◽

Flt3 Ligand ◽

Interleukin 15

Abstract Interleukin-15 (IL-15) is produced by human bone marrow (BM) stromal cells and can induce CD34+ hematopoietic progenitor cells (HPCs) to differentiate into CD56+CD3−natural killer (NK) cells in the absence of stromal cells. IL-15 mediates its effects by signaling through the β and γcchains of the IL-2/15 receptor (R). The c-kit ligand (KL), also produced by stromal cells, enhances the expansion of NK cells from CD34+ HPCs in the presence of IL-15, but alone has no ability to differentiate NK cells. Mice deficient in KL do not appear to have a quantitative deficiency in NK cells, suggesting that other stromal cell factors may contribute to NK cell expansion. Flt3 ligand (FL) is also produced by BM stromal cells and has homology with KL. Furthermore, mice with a targeted disruption of the FL gene have reduced numbers of NK cells. We evaluated here the effects of FL on human NK cell development and expansion from CD34+ HPCs. Like KL, FL significantly enhanced the expansion of NK cells from CD34+ HPCs in the presence of IL-15, compared with IL-15 alone. However, FL alone had no effect on NK cell differentiation. We therefore explored the mechanism by which FL promotes IL-15–mediated NK cell development. FL was found to induce IL-2/15Rβ (CD122) expression on CD34bright HPCs. The CD34brightCD122+ cell coexpressed CD38, but lacked expression of CD7, CD56, NK cell receptors (NKRs), or cytotoxic activity in the absence of IL-15. Using limiting dilution analysis in the presence of IL-15 alone, we demonstrated that the FL-induced CD34brightCD122+ HPCs had an NK cell precursor frequency 20- to 60-fold higher than the CD34dim/negCD122− HPCs and 65- to 235-fold higher than fresh CD34+ HPCs. KL had similar effects as FL, but induced a significantly lower percentage of CD34brightCD122+ cells (P ≤ .01). Both FL and KL also increased IL-15R transcript in CD34+ HPCs. Culture of CD34+ HPCs in FL or KL, followed by culture in IL-15 alone, induced expression of both C-type lectin and Ig-superfamily NKRs on CD56+ cells. These data collectively support a role for FL in early human NK cell development. FL or KL generate a unique CD34brightCD122+CD38+ human NK cell intermediate from CD34+ HPCs that lacks NK features yet is IL-15–responsive. IL-15 is then required for the induction of CD56 and NKRs, LGL morphology, cytotoxic activity, and the ability to produce abundant cytokines and chemokines.

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Natural killer cells suppress human erythroid stem cell proliferation in vitro

Blood ◽

10.1182/blood.v63.2.260.260 ◽

1984 ◽

Vol 63 (2) ◽

pp. 260-269 ◽

Cited By ~ 66

Author(s):

KF Mangan ◽

ME Hartnett ◽

SA Matis ◽

A Winkelstein ◽

T Abo

Keyword(s):

Stem Cell ◽

Natural Killer Cell ◽

Nk Cells ◽

Natural Killer ◽

Nk Cell ◽

Killer Cell ◽

Human Natural Killer Cell ◽

Percoll Density Gradient Centrifugation

Abstract To determine the role of natural killer (NK) cells in the regulation of human erythropoiesis, we studied the effects of NK-enriched cell populations on the in vitro proliferation of erythroid stem cells at three different levels of maturation (day 14 blood BFU-E, day 5–6 marrow CFU-E, and day 10–12 marrow BFU-E). NK cells were enriched from blood by Percoll density gradient centrifugation and by fluorescence- activated cell sorting (FACS), using the human natural killer cell monoclonal antibody, HNK-1. The isolated enriched fractions were cocultured with autologous nonadherent marrow cells or blood null cells and erythropoietin in a methylcellulose erythroid culture system. Cells from low-density Percoll fractions (NK-enriched cells) were predominantly large granular lymphocytes with cytotoxic activity against K562 targets 6–10-fold greater than cells obtained from high- density Percoll fractions (NK-depleted cells). In coculture with marrow nonadherent cells (NA) at NK:NA ratios of 2:1, NK-enriched cells suppressed day 5–6 CFU-E to 62% (p less than 0.025) of controls, whereas NK-depleted cells slightly augmented CFU-E to 130% of controls (p greater than 0.05). In contrast, no suppression of day 10–12 marrow BFU-E was observed employing NK-enriched cells. The NK CFU-E suppressor effects were abolished by complement-mediated lysis of NK-enriched cells with the natural killer cell antibody, HNK-1. Highly purified HNK- 1+ cells separated by FACS suppressed marrow CFU-E to 34% (p less than 0.025) and marrow BFU-E to 41% (p less than 0.025) of controls. HNK- cells had no significant effect on either BFU-E or CFU-E growth. NK- enriched cells were poor stimulators of day 14 blood BFU-E in comparison to equal numbers of NK-depleted cells or T cells isolated by E-rosetting (p less than 0.01). Interferon boosting of NK-enriched cells abolished their suboptimal burst-promoting effects and augmented their CFU-E suppressor effects. These studies provide evidence for a potential regulatory role of NK cells in erythropoiesis. The NK suppressor effect is maximal at the level of the mature erythroid stem cell CFU-E. These findings may explain some hypoproliferative anemias that develop in certain NK cell-activated states.

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Leukocyte Immunoglobulin-Like Receptor 1-Expressing Human Natural Killer Cell Subsets Differentially Recognize Isolates of Human Cytomegalovirus through the Viral Major Histocompatibility Complex Class I Homolog UL18

Journal of Virology ◽

10.1128/jvi.02614-15 ◽

2016 ◽

Vol 90 (6) ◽

pp. 3123-3137 ◽

Cited By ~ 13

Author(s):

Kevin C. Chen ◽

Richard J. Stanton ◽

Jareer J. Banat ◽

Mark R. Wills

Keyword(s):

Immune Responses ◽

Nk Cells ◽

Natural Killer ◽

Cytomegalovirus Infection ◽

Hcmv Infection ◽

Nk Cell ◽

Long Term Memory ◽

Term Memory

ABSTRACTImmune responses of natural killer (NK) cell are controlled by the balance between activating and inhibitory receptors, but the expression of these receptors varies between cells within an individual. Although NK cells are a component of the innate immune system, particular NK cell subsets expressing Ly49H are positively selected and increase in frequency in response to cytomegalovirus infection in mice. Recent evidence suggests that in humans certain NK subsets also have an increased frequency in the blood of human cytomegalovirus (HCMV)-infected individuals. However, whether these subsets differ in their capacity of direct control of HCMV-infected cells remains unclear. In this study, we developed a novelin vitroassay to assess whether human NK cell subsets have differential abilities to inhibit HCMV growth and dissemination. NK cells expressing or lacking NKG2C did not display any differences in controlling viral dissemination. However, whenin vitro-expanded NK cells were used, cells expressing or lacking the inhibitory receptor leukocyte immunoglobulin-like receptor 1 (LIR1) were differentially able to control dissemination. Surprisingly, the ability of LIR1+NK cells to control virus spread differed between HCMV viral strains, and this phenomenon was dependent on amino acid sequences within the viral ligand UL18. Together, the results here outline anin vitrotechnique to compare the long-term immune responses of different human NK cell subsets and suggest, for the first time, that phenotypically defined human NK cell subsets may differentially recognize HCMV infections.IMPORTANCEHCMV infection is ubiquitous in most populations; it is not cleared by the host after primary infection but persists for life. The innate and adaptive immune systems control the spread of virus, for which natural killer (NK) cells play a pivotal role. NK cells can respond to HCMV infection by rapid, short-term, nonspecific innate responses, but evidence from murine studies suggested that NK cells may display long-term, memory-like responses to murine cytomegalovirus infection. In this study, we developed a new assay that examines human NK cell subsets that have been suggested to play a long-term memory-like response to HCMV infection. We show that changes in an HCMV viral protein that interacts with an NK cell receptor can change the ability of NK cell subsets to control HCMV while the acquisition of another receptor has no effect on virus control.

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Enhancing Natural Killer (NK) Cell Mediated Killing of Non-Hodgkin's Lymphoma.

Blood ◽

10.1182/blood.v114.22.2706.2706 ◽

2009 ◽

Vol 114 (22) ◽

pp. 2706-2706 ◽

Cited By ~ 4

Author(s):

Shivani Srivastava ◽

Hailin Feng ◽

Shuhong Zhang ◽

Jing Liang ◽

Patrick Squiban ◽

...

Keyword(s):

Nk Cells ◽

Natural Killer ◽

Tumor Cells ◽

Mhc Class I ◽

Median Survival ◽

Nk Cell ◽

Normal Donor ◽

Natural Cytotoxicity ◽

Raji Cells ◽

Effector Cells

Abstract Abstract 2706 Poster Board II-682 Follicular lymphoma is incurable with the current chemo- or chemoimmunotherapy with median survival of 8–12 years. Relapse free survival after each subsequent therapy steadily decreases, resulting in an expected median survival of 4.5 years following initial relapse. Hence new treatment strategies are needed. Natural killer (NK) cells are important effector cells in mediating the anti-lymphoma effect of rituximab. Indeed, antibody-dependent cell-mediated cytotoxicity (ADCC) is a major mechanisms of action of rituximab with NK cells being important effector cells. However, in addition to ADCC, NK cells also exert natural cytotoxicity against tumor cells, which is modulated by a balance of inhibitory and activating signals through NK cell receptors. NK cell function is inhibited when their inhibitory killer immunoglobulin-like receptors (KIR) are ligated by their cognate MHC class I antigens on tumor targets. The novel agent IPH2101 (1-7F9) is a fully human monoclonal antibody directed against KIR2DL receptor that blocks the interaction of KIR with its HLA-C ligands breaking NK cell tolerance to autologous tumor cells. We investigated whether the combination of the IPH2101and Rituximab will augment the NK cell mediated cytotoxicity against CD20+ lymphoma targets as compared to rituximab alone. Raji cells are human CD20+ Burkitt lymphoma cell line cells that expresses HLA-A*03,- (ligand to inhibitory KIR3DL2); -B*71[Bw6] (no inhibitory KIR-Ligand) and -Cw*03,w*04 (group 1 and 2 of HLA-C ligands to inhibitory KIR2DL2/3 and KIR2DL1), and were chosen for study because they have HLA-C antigens that ligate the inhibitory KIR2DL2/3 and KIR2DLI receptors, making them a good target to test our hypothesis of inhibiting inhibitory KIR. NK cells were isolated from normal donor PBMC (peripheral blood mononuclear cells) with the Miltenyi NK isolation Kit. Using LDH release based cytotoxicity assay, we show (Figure 1) that the treatment of target Raji cells with Rituximab significantly enhanced natural cytotoxicity of the purified NK cells against Raji cells. IPH2101alone treatment of NK cells also significantly enhanced the cytotoxicity of Raji cells, however, the combination of IPH2101treated NK cells against Rituximab treated Raji cells significantly enhanced cytotoxicity beyond that observed with each agent alone. Effector: Target (E:T) ratios of 14:1 or less, from more than 5 random donors showed similar results indicating a synergistic, or at least and additive effect ( representative experiment shown Figure 1) . In these experiments purified NK cells were treated with 30ug/ml of IPH2101for 30 min and Raji targets were treated with 0.1-30ug/ml of Rituximab for 30 min. NK cells in the presence or absence of IPH2101were co-cultured with Raji cells in the presence or absence of Rituximab for 4 hour in a 96 well plate. NK cytotoxicity was assessed with an LDH release based assay. Our results suggest that there is a positive cooperation between natural cytotoxicity mediated through KIR-MHC blockade and that mediated by ADCC. Indeed, wee have shown that the blockade of KIR-MHC class I interaction by anti-KIR blocking antibody (IPH2101) augments the cytotoxicity of freshly isolated normal donor NK cells against CD20+ lymphoma cell lines as compared to rituximab alone, providing a rationale for the clinical investigation of the combination of IPH2101 (1-7F9) and rituximab in non-Hodgkin's lymphoma Disclosures: Squiban: Innate pharma: Employment.

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Pluripotent Stem Cell-Derived Human Natural Killer Cells with Potent Anti-Multiple Myeloma Activity,

Blood ◽

10.1182/blood.v118.21.4034.4034 ◽

2011 ◽

Vol 118 (21) ◽

pp. 4034-4034

Author(s):

David A. Knorr ◽

Zhenya Ni ◽

Allison Bock ◽

Vijay G. Ramakrishnan ◽

Shaji Kumar ◽

...

Keyword(s):

Stem Cells ◽

Multiple Myeloma ◽

Stem Cell ◽

Nk Cells ◽

Natural Killer ◽

Tumor Cells ◽

Adoptive Immunotherapy ◽

Target Cell ◽

Peripheral Blood ◽

Nk Cell

Abstract Abstract 4034 Natural Killer (NK) cells are lymphocytes of the innate immune system with anti-viral and anti-cancer activity. Over the past decade, they have gained interest as a promising cellular source for use in adoptive immunotherapy for the treatment of cancer. Most notably, NK cells play an important role in the graft-vs-tumor effect seen in allogeneic hematopoietic stem cell transplantation (allo-HSCT), and a better understanding of NK cell biology has translated into improved transplant outcomes in acute myelogenous leukemia (AML). Small studies have demonstrated a role for NK cell activity in multiple myeloma (MM) patients receiving allo-HSCT. Investigators have also utilized haplo-identical killer immunoglobulin-like receptor (KIR) mismatched NK cells for adoptive immunotherapy in patients with multiple myeloma (MM). Our group has focused on the development of NK cells from human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) as a novel starting source of lymphocytes for immunotherapy. We have previously demonstrated potent anti-tumor activity of hESC-derived NK cells in vitro and in vivo against a variety of different targets. We have also shown that iPSC-derived NK cells from a variety of different somatic cell starting sources posses potent anti-tumor and anti-viral activity. Here, we demonstrate hESC- and iPSC-derived NK cell development in a completely defined, feeder-free system that is amenable to clinical scale-up. These cultures contain a pure population of mature NK cells devoid of any T or B cell contamination, which are common adverse bystanders of cellular products isolated and enriched from peripheral blood. Our cultures are homogenous for their expression of CD56 and express high levels of effector molecules known to be important in anti-MM activity, including KIR, CD16, NKG2D, NKp46, NKp44, FasL and TRAIL. We have now tested the activity of hESC- and iPSC-derived NK cells against MM tumor cells in order to provide a universal source of lymphocytes for adoptive immunotherapy in patients with treatment refractory disease. We find that similar to peripheral blood NK cells (PB-NK), hESC- and iPSC-derived NK cells are cytotoxic against 3 distinct MM cell lines in a standard chromium release cytotoxicity assay. Specifically, activated PB-NK cells killed 48.5% of targets at 10 to 1 effector to target ratios, whereas hESC (46.3%) and iPSC (42.4%) derived NK cells also demonstrated significant anti-MM activity. Also, hESC- and iPSC-derived NK cells secrete cytokines (IFNγ and TNFα) and degranulate as demonstrated by CD107a surface expression in response to MM target cell stimulation. When tested against freshly isolated samples from MM patients, hESC- and IPSC-derived NK cells respond at a similar level as activated PB-NK cells, the current source of NK cells used in adoptive immunotherapy trials. These MM targets (both cell lines and primary tumor cells) are known to express defined ligands (MICA/B, DR4/5, ULBP-1, BAT3) for receptors expressed on NK cells as well as a number of undefined ligands for natural cytotoxicity receptors (NCRs) and KIR. As these receptor-ligand interactions drive the anti-MM activity of NK cells, we are currently evaluating expression of each of these molecules on the surface of both the effector and target cell populations. Not only do hESC- and iPSC-derived NK cells provide a unique, homogenous cell population to study these interactions, they also provide a genetically tractable source of lymphocytes for improvement of the graft-vs-myeloma effect and could be tailored on a patient specific basis using banks of hESC-or iPSC-derived NK cells with defined KIR genotypes for use as allogeneic or autologous effector cells. Disclosures: No relevant conflicts of interest to declare.

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The PD-1/PD-L1 axis modulates the natural killer cell versus multiple myeloma effect: a therapeutic target for CT-011, a novel monoclonal anti–PD-1 antibody

Blood ◽

10.1182/blood-2010-02-271874 ◽

2010 ◽

Vol 116 (13) ◽

pp. 2286-2294 ◽

Cited By ~ 459

Author(s):

Don M. Benson ◽

Courtney E. Bakan ◽

Anjali Mishra ◽

Craig C. Hofmeister ◽

Yvonne Efebera ◽

...

Keyword(s):

Multiple Myeloma ◽

Immune Response ◽

Nk Cells ◽

Natural Killer ◽

Tumor Cells ◽

Cell Function ◽

Nk Cell ◽

Killer Cell ◽

Cell Immune Response ◽

Cell Versus

Abstract T-cell expression of programmed death receptor-1 (PD-1) down-regulates the immune response against malignancy by interacting with cognate ligands (eg, PD-L1) on tumor cells; however, little is known regarding PD-1 and natural killer (NK) cells. NK cells exert cytotoxicity against multiple myeloma (MM), an effect enhanced through novel therapies. We show that NK cells from MM patients express PD-1 whereas normal NK cells do not and confirm PD-L1 on primary MM cells. Engagement of PD-1 with PD-L1 should down-modulate the NK-cell versus MM effect. We demonstrate that CT-011, a novel anti–PD-1 antibody, enhances human NK-cell function against autologous, primary MM cells, seemingly through effects on NK-cell trafficking, immune complex formation with MM cells, and cytotoxicity specifically toward PD-L1+ MM tumor cells but not normal cells. We show that lenalidomide down-regulates PD-L1 on primary MM cells and may augment CT-011's enhancement of NK-cell function against MM. We demonstrate a role for the PD-1/PD-L1 signaling axis in the NK-cell immune response against MM and a role for CT-011 in enhancing the NK-cell versus MM effect. A phase 2 clinical trial of CT-011 in combination with lenalidomide for patients with MM should be considered.

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The Axl/Gas6 pathway is required for optimal cytokine signaling during human natural killer cell development

Blood ◽

10.1182/blood-2008-05-157073 ◽

2009 ◽

Vol 113 (11) ◽

pp. 2470-2477 ◽

Cited By ~ 41

Author(s):

Il-Kyoo Park ◽

Chiara Giovenzana ◽

Tiffany L. Hughes ◽

Jianhua Yu ◽

Rossana Trotta ◽

...

Keyword(s):

Nk Cells ◽

Natural Killer ◽

Nk Cell ◽

Killer Cell ◽

Absolute Number ◽

Interferon Γ ◽

Cell Development ◽

Cytokine Signaling ◽

Human Natural Killer Cell ◽

Human Cd34

Interleukin-15 (IL-15) is essential for natural killer (NK) cell differentiation. In this study, we assessed whether the receptor tyrosine kinase Axl and its ligand, Gas6, are involved in IL-15–mediated human NK differentiation from CD34+ hematopoietic progenitor cells (HPCs). Blocking the Axl-Gas6 interaction with a soluble Axl fusion protein (Axl-Fc) or the vitamin K inhibitor warfarin significantly diminished the absolute number and percentage of CD3−CD56+ NK cells derived from human CD34+ HPCs cultured in the presence of IL-15, probably resulting in part from reduced phosphorylation of STAT5. In addition, CD3−CD56+ NK cells derived from culture of CD34+ HPCs with IL-15 and Axl-Fc had a significantly diminished capacity to express interferon-γ or its master regulator, T-BET. Culture of CD34+ HPCs in the presence of c-Kit ligand and Axl-Fc resulted in a significant decrease in the frequency of NK precursor cells responding to IL-15, probably the result of reduced c-Kit phosphorylation. Collectively, our data suggest that the Axl/Gas6 pathway contributes to normal human NK-cell development, at least in part via its regulatory effects on both the IL-15 and c-Kit signaling pathways in CD34+ HPCs, and to functional NK-cell maturation via an effect on the master regulatory transcription factor T-BET.

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Allotype-specific processing of the CD16a N45-glycan from primary human natural killer cells and monocytes

Glycobiology ◽

10.1093/glycob/cwaa002 ◽

2020 ◽

Vol 30 (7) ◽

pp. 427-432

Author(s):

Kashyap R Patel ◽

Jacob T Roberts ◽

Adam W Barb

Keyword(s):

Natural Killer Cells ◽

Nk Cells ◽

Natural Killer ◽

Viral Infections ◽

Nk Cell ◽

Cell Surface Receptor ◽

Mass Spectrometry Analysis ◽

Healthy Human ◽

Killer Cells ◽

Spectrometry Analysis

Abstract Fc γ receptor IIIa/CD16a is an activating cell surface receptor with a well-defined role in natural killer (NK) cell and monocyte effector function. The extracellular domain is decorated with five asparagine (N)-linked glycans; N-glycans at N162 and N45 directly contribute to high-affinity antibody binding and protein stability. N-glycan structures at N162 showed significant donor-dependent variation in a recent study of CD16a isolated from primary human NK cells, but structures at N45 were relatively homogeneous. In this study, we identified variations in N45 glycan structures associated with a polymorphism coding for histidine instead of leucine at position 48 of CD16a from two heterozygous donors. It is known that H48 homozygous individuals suffer from immunodeficiency and recurrent viral infections. A mass spectrometry analysis of protein isolated from the primary natural killer cells of individuals expressing both CD16a L48 and H48 variants demonstrated clear processing differences at N45. CD16a H48 displayed a greater proportion of complex-type N45 glycans compared to the more common L48 allotype with predominantly hybrid N45-glycoforms. Structures at the four other N-glycosylation sites showed minimal differences from data collected on donors expressing only the predominant L48 variant. CD16a H48 purified from a pool of monocytes similarly displayed increased processing at N45. Here, we provide evidence that CD16a processing is affected by the H48 residue in primary NK cells and monocytes from healthy human donors.

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Overview of Strategies to Improve Therapy against Tumors Using Natural Killer Cell

Journal of Immunology Research ◽

10.1155/2020/8459496 ◽

2020 ◽

Vol 2020 ◽

pp. 1-16 ◽

Cited By ~ 2

Author(s):

Chaopin Yang ◽

Yue Li ◽

Yaozhang Yang ◽

Zhiyi Chen

Keyword(s):

Immune Function ◽

Nk Cells ◽

Natural Killer ◽

Tumor Cells ◽

Nk Cell ◽

Therapeutic Potential ◽

Tumor Therapy ◽

Killer Cell ◽

Oncolytic Viruses ◽

Target Area

NK cells are lymphocytes with antitumor properties and can directly lyse tumor cells in a non-MHC-restricted manner. However, the tumor microenvironment affects the immune function of NK cells, which leads to immune evasion. This may be related to the pathogenesis of some diseases. Therefore, great efforts have been made to improve the immunotherapy effect of natural killer cells. NK cells from different sources can meet different clinical needs, in order to minimize the inhibition of NK cells and maximize the response potential of NK cells, for example, modification of NK cells can increase the number of NK cells in tumor target area, change the direction of NK cells, and improve their targeting ability to malignant cells. Checkpoint blocking is also a promising strategy for NK cells to kill tumor cells. Combination therapy is another strategy for improving antitumor ability, especially in combination with oncolytic viruses and nanomaterials. In this paper, the mechanisms affecting the activity of NK cells were reviewed, and the therapeutic potential of different basic NK cell strategies in tumor therapy was focused on. The main strategies for improving the immune function of NK cells were described, and some new strategies were proposed.

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