Valproic acid inhibits interferon-γ production by NK cells and increases susceptibility to Listeria monocytogenes infection

Abstract Valproic acid (VPA) is a drug commonly used for epileptic seizure control. Recently, it has been shown that VPA alters the activation of several immune cells, including Natural Killer (NK) cells, which play an important role in the containment of viruses and intracellular bacteria. Although VPA can increase susceptibility to extracellular pathogens, it is unknown whether the suppressor effect of VPA could affect the course of intracellular bacterial infection. This study aimed to evaluate the role of VPA during Listeria monocytogenes (L.m) infection, and whether NK cell activation was affected. We found that VPA significantly augmented mortality in L.m infected mice. This effect was associated with increased bacterial load in the spleen, liver, and blood. Concurrently, decreased levels of IFN-γ in serum and lower splenic indexes were observed. Moreover, in vitro analysis showed that VPA treatment decreased the frequency of IFN-γ-producing NK cells within L.m infected splenocytes. Similarly, VPA inhibited the production of IFN-γ by NK cells stimulated with IL-12 and IL-18, which is a crucial system for early IFN-γ production in listeriosis. Finally, VPA decreased the phosphorylation of STAT4, p65, and p38, without affecting the expression of IL-12 and IL-18 receptors. Altogether, our results indicate that VPA increases the susceptibility to Listeria monocytogenes infection and suggest that NK cell is one of the main targets of VPA, but further work is needed to ascertain this effect.

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Natural-killer cells and dendritic cells: “l'union fait la force”

Blood ◽

10.1182/blood-2005-03-1154 ◽

2005 ◽

Vol 106 (7) ◽

pp. 2252-2258 ◽

Cited By ~ 386

Author(s):

Thierry Walzer ◽

Marc Dalod ◽

Scott H. Robbins ◽

Laurence Zitvogel ◽

Eric Vivier

Keyword(s):

Dendritic Cells ◽

Nk Cells ◽

Natural Killer ◽

Cell Activation ◽

Nk Cell ◽

Interleukin 12 ◽

Cell Contact ◽

Ifn Γ

AbstractSeveral recent publications have focused on the newly described interactions between natural-killer (NK) cells and dendritic cells (DCs). Activated NK cells induce DC maturation either directly or in synergy with suboptimal levels of microbial signals. Immature DCs appear susceptible to autologous NK-cell-mediated cytolysis while mature DCs are protected. NK-cell-induced DC activation is dependent on both tumor necrosis factor-α (TNF-α)/interferon-γ (IFN-γ) secretion and a cell-cell contact involving NKp30. In vitro, interleukin-12 (IL-12)/IL-18, IL-15, and IFN-α/β production by activated DCs enhance, in turn, NK-cell IFN-γ production, proliferation, and cytotoxic potential, respectively. In vivo, NK-cell/DC interactions may occur in lymphoid organs as well as in nonlymphoid tissues, and their consequences are multiple. By inducing DC activation, NK-cell activation induced by tumor cells can indirectly promote antitumoral T-cell responses. Reciprocally, DCs activated through Toll-like receptors (TLRs) induce potent NK-cell activation in antiviral responses. Thus, DCs and NK cells are equipped with complementary sets of receptors that allow the recognition of various pathogenic agents, emphasizing the role of NK-cell/DC crosstalk in the coordination of innate and adaptive immune responses.

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Ascophyllan Induces Activation of Natural Killer Cells in Mice In Vivo and In Vitro

Marine Drugs ◽

10.3390/md17040197 ◽

2019 ◽

Vol 17 (4) ◽

pp. 197 ◽

Cited By ~ 5

Author(s):

Wei Zhang ◽

Takasi Okimura ◽

Tatsuya Oda ◽

Jun-O Jin

Keyword(s):

Nk Cells ◽

Natural Killer ◽

Cell Activation ◽

Nk Cell ◽

Promote Cell Proliferation ◽

Ifn Γ ◽

Human And Mouse ◽

Marine Polysaccharide

Natural marine polysaccharides have demonstrated immune stimulatory effects in both mice and humans. Our previous study compared the ability of ascophyllan and fucoidan to activate human and mouse dendritic cells (DCs). In this study, we further examined the effect of ascophyllan on the activation of mouse natural killer (NK) cells in vivo and in vitro and compared it to that of fucoidan, a well-studied natural marine polysaccharide. Specifically, administration of ascophyllan to C57BL/6 mice increased the number of NK cells in the spleen when compared to the number in PBS-treated mice. Moreover, the number of IFN-γ-producing NK cells and expression of CD69 were markedly upregulated by ascophyllan treatment. Ascophyllan treatment also induced IFN-γ production and CD69 upregulation in isolated NK cells, but did not promote cell proliferation. Finally, ascophyllan treatment increased the cytotoxicity of NK cells against Yac-1 cells. The effects of ascophyllan on NK cell activation were considerably stronger than those of fucoidan. These data demonstrated that ascophyllan promotes NK cell activation both in mice and in vitro, and its stimulatory effect on NK cells is stronger than that of fucoidan.

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Impaired NK cell cytotoxicity by high level of interferon-γ in concanavalin A-induced hepatitis

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y05-093 ◽

2005 ◽

Vol 83 (11) ◽

pp. 1045-1053 ◽

Cited By ~ 11

Author(s):

Zhongjun Dong ◽

Cai Zhang ◽

Haiming Wei ◽

Rui Sun ◽

Zhigang Tian

Keyword(s):

Nk Cells ◽

Cell Lines ◽

Nk Cell ◽

Interferon Γ ◽

Cell Cytotoxicity ◽

Wild Mice ◽

Ifn Γ ◽

Nk Cell Cytotoxicity

Unlike T cells, the role of natural killer (NK) cells is not well documented in the concanavalin (ConA)- induced hepatitis model. This study aimed to investigate the regulatory effect of high levels of interferon-γ (IFN-γ) on NK cells in ConA-induced hepatitis. The cytotoxicities of NK cells from ConA-injected mice or NK cell lines (NK92 and NKL) were detected by the 4-h 51Cr release assay. Depletion of NK cells with AsGM1 antibody was used to assess the NK cell role in ConA-induced hepatitis. Expression of NK cell receptors and cytotoxic molecules was measured by reverse transcription – polymerase chain reaction. Twelve hours after ConA injection, serum IFN-γ was significantly increased in wild mice, but not in severe combined immunodeficiency mice, and hepatic NK cells exerted impaired cytotoxicity against YAC-l cells in wild mice. Eight hours after NK cells were incubated in serum from ConA-treated mice, NK cell cytotoxicity was down-modulated and the effect was abolished by pretreatment with neutralizing serum IFN-γ with specific antibody in vitro. A high concentration of IFN-γ (> 1000 U/mL) inhibited the cytotoxicities of 2 NK cell lines in vitro, accompanied with down-regulation of NKG2D transcripts and up-regulation of NKG2A/B and KIR2DL transcripts. The inhibitive role of IFN-γ was not seen in NKG2D ligand negative cells. These results suggest that NK cell cytotoxicity was inhibited by high levels of IFN-γ in ConA-induced hepatitis, which may relate to the dispensable role of NK cells.Key words: cytotoxicity, hepatoimmunology, interferon-γ, liver injury.

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Dendritic Cell and NK Cell Reciprocal Cross Talk Promotes Gamma Interferon-Dependent Immunity to Blood-Stage Plasmodium chabaudi AS Infection in Mice

Infection and Immunity ◽

10.1128/iai.00994-08 ◽

2008 ◽

Vol 77 (2) ◽

pp. 770-782 ◽

Cited By ~ 64

Author(s):

Rebecca Ing ◽

Mary M. Stevenson

Keyword(s):

Nk Cells ◽

Cross Talk ◽

Cell Activation ◽

Reciprocal Cross ◽

Nk Cell ◽

Gamma Interferon ◽

Cell Contact ◽

Ifn Γ ◽

Dc Maturation

ABSTRACT Dendritic cells (DCs) are important accessory cells for promoting NK cell gamma interferon (IFN-γ) production in vitro in response to Plasmodium falciparum-infected red blood cells (iRBC). We investigated the requirements for reciprocal activation of DCs and NK cells leading to Th1-type innate and adaptive immunity to P. chabaudi AS infection. During the first week of infection, the uptake of iRBC by splenic CD11c+ DCs in resistant wild-type (WT) C57BL/6 mice was similar to that in interleukin 15−/− (IL-15−/−) and IL-12p40−/− mice, which differ in the severity of P. chabaudi AS infection. DCs from infected IL-15−/− mice expressed costimulatory molecules, produced IL-12, and promoted IFN-γ secretion by WT NK cells in vitro as efficiently as WT DCs. In contrast, DCs from infected IL-12p40−/− mice exhibited alterations in maturation and cytokine production and were unable to induce NK cell IFN-γ production. Coculture of DCs and NK cells demonstrated that DC-mediated NK cell activation required IL-12 and, to a lesser extent, IL-2, as well as cell-cell contact. In turn, NK cells from infected WT mice enhanced DC maturation, IL-12 production, and priming of CD4+ T-cell proliferation and IFN-γ secretion. Infected WT mice depleted of NK cells, which exhibit increased parasitemia, had impaired DC maturation and DC-induced CD4+ Th1 cell priming. These findings indicate that DC-NK cell reciprocal cross talk is critical for control and rapid resolution of P. chabaudi AS infection and provide in vivo evidence for the importance of this interaction in IFN-γ-dependent immunity to malaria.

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Role of fractalkine (CX3CL1) rich neuroblastoma microenvironments for ganglioside GD2 directed immunotherapy

Journal of Clinical Oncology ◽

10.1200/jco.2007.25.18_suppl.9521 ◽

2007 ◽

Vol 25 (18_suppl) ◽

pp. 9521-9521

Author(s):

H. N. Lode ◽

Y. Zeng ◽

S. Fest ◽

G. Gaedicke

Keyword(s):

T Cell ◽

Nk Cells ◽

Therapeutic Effect ◽

Cell Activation ◽

Nk Cell ◽

Ganglioside Gd2 ◽

Ifn Γ

9521 Background: Fractalkine (FKN) is a unique CX3C chemokine (CX3CL1) known to induce adhesion and migration of leukocytes mediated by a membrane-bound and a soluble form. Methods: We found that FKN is expressed in >90% of 68 neuroblastoma (NB) samples as determined by cDNA microarray analysis. FKN expression was inversely correlated with MYCN amplification, suggesting a higher expression of FKN in MYCN non amplified tumors. We characterized the effect of FKN in the neuroblastoma microenvironment in a mouse model. We demonstrate that FKN released from NB cells mediate migration and adhesion of CD4+-, CD8+- and NK- cells and subsequent secretion of IFN-γ, in vitro and in vivo. However, the presence of FKN in NB microenvironments did not result in significant anti-NB activity. Results: Targeting of IL-2 into the NB microenvironment using anti-ganglioside GD2 antibody cytokine fusion proteins (ch14.18-IL-2) is currently under clinical evaluation. We investigated a the role of FKN in this context. For this purpose, IL-2 was targeted to GD2 positive NB microenvironments secreting FKN. Only mice bearing FKN and IL2 enriched NB microenvironments exhibited a reduction in primary tumor growth and a complete eradication of experimental liver metastases, in contrast to controls with only FKN or IL-2 enriched NB. This effect was specific since a non-specific antibody-IL-2 fusion protein ch225-IL-2 was ineffective. The mechanisms involved included NK-cell activation by targeted IL-2 into FKN rich NB as indicated by the enhancement of NK-cell mediated lysis using YAC-1 cells as targeted cells. The depletion of NK cells in vivo inhibited the therapeutic effect. Furthermore, co-culture of NXS2-FKN cells and NK cells in vitro induced the expression of IFN-γ by NK cells. However, the depletion of CD8+ T-cells in vivo abrogated the therapeutic effect, and these effector cells showed the highest cytolytic activity against NXS2 target cells in vitro. Finally, only the FKN and IL-2 enriched NB microenvironment resulted in T-cell activation and the release of proinflammatory cytokines. Conclusions: In conclusion our data suggest that targeted IL-2 therapy of FKN rich NB associated with MYCN non-amplified tumors may result in T-cell mediated immune responses. No significant financial relationships to disclose.

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NK cell activation in visceral leishmaniasis requires TLR9, myeloid DCs, and IL-12, but is independent of plasmacytoid DCs

Journal of Experimental Medicine ◽

10.1084/jem.20061293 ◽

2007 ◽

Vol 204 (4) ◽

pp. 893-906 ◽

Cited By ~ 124

Author(s):

Ulrike Schleicher ◽

Jan Liese ◽

Ilka Knippertz ◽

Claudia Kurzmann ◽

Andrea Hesse ◽

...

Keyword(s):

Visceral Leishmaniasis ◽

Nk Cells ◽

Cell Activation ◽

Nk Cell ◽

Dependent Manner ◽

Cell Cytotoxicity ◽

Ifn Γ ◽

Nk Cell Cytotoxicity

Natural killer (NK) cells are sentinel components of the innate response to pathogens, but the cell types, pathogen recognition receptors, and cytokines required for their activation in vivo are poorly defined. Here, we investigated the role of plasmacytoid dendritic cells (pDCs), myeloid DCs (mDCs), Toll-like receptors (TLRs), and of NK cell stimulatory cytokines for the induction of an NK cell response to the protozoan parasite Leishmania infantum. In vitro, pDCs did not endocytose Leishmania promastigotes but nevertheless released interferon (IFN)-α/β and interleukin (IL)-12 in a TLR9-dependent manner. mDCs rapidly internalized Leishmania and, in the presence of TLR9, produced IL-12, but not IFN-α/β. Depletion of pDCs did not impair the activation of NK cells in L. infantum–infected mice. In contrast, L. infantum–induced NK cell cytotoxicity and IFN-γ production were abolished in mDC-depleted mice. The same phenotype was observed in TLR9−/− mice, which lacked IL-12 expression by mDCs, and in IL-12−/− mice, whereas IFN-α/β receptor−/− mice showed only a minor reduction of NK cell IFN-γ expression. This study provides the first direct evidence that mDCs are essential for eliciting NK cell cytotoxicity and IFN-γ release in vivo and demonstrates that TLR9, mDCs, and IL-12 are functionally linked to the activation of NK cells in visceral leishmaniasis.

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Dengue Virus-Infected Dendritic Cells, but Not Monocytes, Activate Natural Killer Cells through a Contact-Dependent Mechanism Involving Adhesion Molecules

mBio ◽

10.1128/mbio.00741-17 ◽

2017 ◽

Vol 8 (4) ◽

Cited By ~ 25

Author(s):

Vivian Vasconcelos Costa ◽

Weijian Ye ◽

Qingfeng Chen ◽

Mauro Martins Teixeira ◽

Peter Preiser ◽

...

Keyword(s):

Dendritic Cells ◽

Virus Infection ◽

Dengue Virus ◽

Nk Cells ◽

Adhesion Molecules ◽

Cell Activation ◽

Nk Cell ◽

Denv Infection ◽

Ifn Γ

ABSTRACT Natural killer (NK) cells play a protective role against dengue virus (DENV) infection, but the cellular and molecular mechanisms are not fully understood. Using an optimized humanized mouse model, we show that human NK cells, through the secretion of gamma interferon (IFN-γ), are critical in the early defense against DENV infection. Depletion of NK cells or neutralization of IFN-γ leads to increased viremia and more severe thrombocytopenia and liver damage in humanized mice. In vitro studies using autologous human NK cells show that DENV-infected monocyte-derived dendritic cells (MDDCs), but not monocytes, activate NK cells in a contact-dependent manner, resulting in upregulation of CD69 and CD25 and secretion of IFN-γ. Blocking adhesion molecules (LFA-1, DNAM-1, CD2, and 2β4) on NK cells abolishes NK cell activation, IFN-γ secretion, and the control of DENV replication. NK cells activated by infected MDDCs also inhibit DENV infection in monocytes. These findings show the essential role of human NK cells in protection against acute DENV infection in vivo, identify adhesion molecules and dendritic cells required for NK cell activation, and delineate the sequence of events for NK cell activation and protection against DENV infection. IMPORTANCE Dengue is a mosquito-transmitted viral disease with a range of symptoms, from mild fever to life-threatening dengue hemorrhagic fever. The diverse disease manifestation is thought to result from a complex interplay between viral and host factors. Using mice engrafted with a human immune system, we show that human NK cells inhibit virus infection through secretion of the cytokine gamma interferon and reduce disease pathogenesis, including depletion of platelets and liver damage. During a natural infection, DENV initially infects dendritic cells in the skin. We find that NK cells interact with infected dendritic cells through physical contact mediated by adhesion molecules and become activated before they can control virus infection. These results show a critical role of human NK cells in controlling DENV infection in vivo and reveal the sequence of molecular and cellular events that activate NK cells to control dengue virus infection. IMPORTANCE Dengue is a mosquito-transmitted viral disease with a range of symptoms, from mild fever to life-threatening dengue hemorrhagic fever. The diverse disease manifestation is thought to result from a complex interplay between viral and host factors. Using mice engrafted with a human immune system, we show that human NK cells inhibit virus infection through secretion of the cytokine gamma interferon and reduce disease pathogenesis, including depletion of platelets and liver damage. During a natural infection, DENV initially infects dendritic cells in the skin. We find that NK cells interact with infected dendritic cells through physical contact mediated by adhesion molecules and become activated before they can control virus infection. These results show a critical role of human NK cells in controlling DENV infection in vivo and reveal the sequence of molecular and cellular events that activate NK cells to control dengue virus infection.

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

Endocrine Related Cancer ◽

10.1530/erc-21-0048 ◽

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.

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Stem Cell Factor Enhances Interleukin-2–Mediated Expansion of Murine Natural Killer Cells In Vivo

Blood ◽

10.1182/blood.v90.9.3647 ◽

1997 ◽

Vol 90 (9) ◽

pp. 3647-3653 ◽

Cited By ~ 26

Author(s):

Todd A. Fehniger ◽

William E. Carson ◽

Ewa Mrózek ◽

Michael A. Caligiuri

Keyword(s):

Nk Cells ◽

Cell Expansion ◽

Stem Cell Factor ◽

Low Dose ◽

Nk Cell ◽

Interleukin 2 ◽

Innate Immune ◽

Ifn Γ

Abstract The administration of low dose interleukin-2 (IL-2) results in a selective expansion of natural killer (NK) cells in vivo, and promotes the differentiation of NK cells from hematopoietic precursor cells in vitro. We have previously shown that stem cell factor (SCF ), the ligand to the c-kit tyrosine kinase receptor, enhances IL-2–induced NK cell proliferation and differentiation in vitro. Here, we investigated the effects of SCF plus IL-2 delivered to mice in vivo. Eight-week-old C57BL/6 mice were treated with a continuous subcutaneous infusion of IL-2 (1 × 104 IU/d) plus a daily intraperitoneal dose of SCF (100 μg/kg/d), IL-2 alone, SCF alone, or vehicle alone for 8 weeks. The in vivo serum concentration of IL-2 ranged between 352 ± 12.0 pg/mL and 606 ± 9.0 pg/mL, achieving selective saturation of the high affinity IL-2 receptor, while the peak SCF serum concentration was 296 ± 13.09 ng/mL. Alone, the daily administration of SCF had no effect on the expansion of NK cells. The continuous infusion of IL-2 alone did result in a significant expansion of NK1.1+CD3− cells compared to mice treated with placebo or SCF. However, mice treated with both SCF and IL-2 showed an increase in the absolute number of NK cells that was more than twofold that seen with IL-2 alone, in the spleen (P ≤ .005), bone marrow (P ≤ .025), and blood (P < .05). NK cytotoxic activity against YAC-1 target cells was significantly higher for mice treated with SCF plus IL-2, compared to mice treated with IL-2 alone (P ≤ .0005). Interferon-γ (IFN-γ) production in cytokine-activated splenocytes was also greater for the SCF plus IL-2 group, over IL-2 treatment alone (P ≤ .01). The effect of SCF plus IL-2 on NK cell expansion was likely mediated via NK cell precursors, rather than mature NK cells. In summary, we provide the first evidence that SCF can significantly enhance expansion of functional NK cells induced by the prolonged administration of low dose IL-2 in vivo. Since the NK cell is a cytotoxic innate immune effector and a potent source of IFN-γ, this therapeutic strategy for NK cell expansion may serve to further enhance innate immune surveillance against malignant transformation and infection in the setting of cancer and/or immunodeficiency.

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SARS-CoV-2 Spike 1 Protein Controls Natural Killer Cell Activation via the HLA-E/NKG2A Pathway

Cells ◽

10.3390/cells9091975 ◽

2020 ◽

Vol 9 (9) ◽

pp. 1975 ◽

Cited By ~ 2

Author(s):

Daria Bortolotti ◽

Valentina Gentili ◽

Sabrina Rizzo ◽

Antonella Rotola ◽

Roberta Rizzo

Keyword(s):

Epithelial Cells ◽

Nk Cells ◽

Natural Killer ◽

Cell Activation ◽

Nk Cell ◽

Killer Cell ◽

Lung Epithelial Cells ◽

Lung Epithelial ◽

Spike Proteins

Natural killer cells are important in the control of viral infections. However, the role of NK cells during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has previously not been identified. Peripheral blood NK cells from SARS-CoV and SARS-CoV-2 naïve subjects were evaluated for their activation, degranulation, and interferon-gamma expression in the presence of SARS-CoV and SARS-CoV-2 spike proteins. K562 and lung epithelial cells were transfected with spike proteins and co-cultured with NK cells. The analysis was performed by flow cytometry and immune fluorescence. SARS-CoV and SARS-CoV-2 spike proteins did not alter NK cell activation in a K562 in vitro model. On the contrary, SARS-CoV-2 spike 1 protein (SP1) intracellular expression by lung epithelial cells resulted in NK cell-reduced degranulation. Further experiments revealed a concomitant induction of HLA-E expression on the surface of lung epithelial cells and the recognition of an SP1-derived HLA-E-binding peptide. Simultaneously, there was increased modulation of the inhibitory receptor NKG2A/CD94 on NK cells when SP1 was expressed in lung epithelial cells. We ruled out the GATA3 transcription factor as being responsible for HLA-E increased levels and HLA-E/NKG2A interaction as implicated in NK cell exhaustion. We show for the first time that NK cells are affected by SP1 expression in lung epithelial cells via HLA-E/NKG2A interaction. The resulting NK cells’ exhaustion might contribute to immunopathogenesis in SARS-CoV-2 infection.

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