Sustained NKG2D engagement induces cross-tolerance of multiple distinct NK cell activation pathways

Blood ◽  
2008 ◽  
Vol 111 (7) ◽  
pp. 3571-3578 ◽  
Author(s):  
Jérôme D. Coudert ◽  
Léonardo Scarpellino ◽  
Frédéric Gros ◽  
Eric Vivier ◽  
Werner Held

Abstract NKG2D is a multisubunit activation receptor that allows natural killer (NK) cells to detect and eliminate stressed, infected, and transformed host cells. However, the chronic exposure of NK cells to cell-bound NKG2D ligands has been shown to impair NKG2D function both in vitro and in vivo. Here we have tested whether continuous NKG2D engagement selectively impacted NKG2D function or whether heterologous NK cell activation pathways were also affected. We found that sustained NKG2D engagement induced cross-tolerization of several unrelated NK cell activation receptors. We show that receptors that activate NK cells via the DAP12/KARAP and DAP10 signaling adaptors, such as murine NKG2D and Ly49D, cross-tolerize preferentially NK cell activation pathways that function independent of DAP10/12, such as antibody-dependent cell-mediated cytotoxicity and missing-self recognition. Conversely, DAP10/12-independent pathways are unable to cross-tolerize unrelated NK cell activation receptors such as NKG2D or Ly49D. These data define a class of NK cell activation receptors that can tolerize mature NK cells. The reversible suppression of the NK cells' cytolytic function probably reduces the NK cells' efficacy to control endogenous and exogenous stress yet may be needed to limit tissue damage.

Blood ◽  
2005 ◽  
Vol 106 (7) ◽  
pp. 2252-2258 ◽  
Author(s):  
Thierry Walzer ◽  
Marc Dalod ◽  
Scott H. Robbins ◽  
Laurence Zitvogel ◽  
Eric Vivier

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.


Marine Drugs ◽  
2019 ◽  
Vol 17 (4) ◽  
pp. 197 ◽  
Author(s):  
Wei Zhang ◽  
Takasi Okimura ◽  
Tatsuya Oda ◽  
Jun-O Jin

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.


2004 ◽  
Vol 200 (3) ◽  
pp. 287-295 ◽  
Author(s):  
Francesca Granucci ◽  
Ivan Zanoni ◽  
Norman Pavelka ◽  
Serani L.H. van Dommelen ◽  
Christopher E. Andoniou ◽  
...  

Dendritic cells (DCs) play a predominant role in activation of natural killer (NK) cells that exert their functions against pathogen-infected and tumor cells. Here, we used a murine model to investigate the molecular mechanisms responsible for this process. Two soluble molecules produced by bacterially activated myeloid DCs are required for optimal priming of NK cells. Type I interferons (IFNs) promote the cytotoxic functions of NK cells. IL-2 is necessary both in vitro and in vivo for the efficient production of IFNγ, which has an important antimetastatic and antibacterial function. These findings provide new information about the mechanisms that mediate DC–NK cell interactions and define a novel and fundamental role for IL-2 in innate immunity.


2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
FANG ZHOU ◽  
Darise Farris

Thrombotic thrombocytopenic purpura (TTP) is a rare life-threaten vascular autoimmune disease. There is no effective method to treat it in clinical trials since pathogenesis of TTP has not been fully elucidated. Here we investigate the role of NK cells in relapse development of TTP. Our results showed that the frequencies of CD3 − CD56 dim CD16 − and CD3 − CD56 bri CD16 − NK cells are increased in TTP patients with a history of relapse. Expression of CD107a, granzyme A and IFN-γ by CD3 − CD56 dim NK cells following in vitro stimulation with PMA/ionomycin / monensin is improved in the relapse group, compared with those on NK cells derived from TTP patients without relapse development. NK cells isolated from TTP patients with a history of relapse indicated stronger cytotoxicity to target K562 cells than those of NK cells derived from TTP patients without relapse development, suggesting prior activation of NK cells in vivo . Treatment with anti-human CD16 antibody up-regulates cytotoxicity of NK cells derived from TTP patients without relapse development. However, Anti-human CD16 antibody treatment does not affect cytotoxicity of NK cells isolated from TTP patients with a history of relapse, suggesting inability of CD16-mediated signaling in NK cells derived from TTP patients with relapse development. These data provide evidence of altered NK cell activation and/or licensing in TTP patients with a history of relapse modulated by CD16-mediated signaling and a new avenue of investigation into mechanisms of TTP immunopathogenesis.


2008 ◽  
Vol 205 (5) ◽  
pp. 1213-1225 ◽  
Author(s):  
Erwan Mortier ◽  
Tammy Woo ◽  
Rommel Advincula ◽  
Sara Gozalo ◽  
Averil Ma

Natural killer (NK) cells are innate immune effectors that mediate rapid responses to viral antigens. Interleukin (IL)-15 and its high affinity IL-15 receptor, IL-15Rα, support NK cell homeostasis in resting animals via a novel trans presentation mechanism. To better understand how IL-15 and IL-15Rα support NK cell activation during immune responses, we have used sensitive assays for detecting native IL-15 and IL-15Rα proteins and developed an assay for detecting complexes of these proteins. We find that IL-15 and IL-15Rα are preassembled in complexes within the endoplasmic reticulum/Golgi of stimulated dendritic cells (DCs) before being released from cells. IL-15Rα is required for IL-15 production by DCs, and IL-15 that emerges onto the cell surface of matured DCs does not bind to neighboring cells expressing IL-15Rα. We also find that soluble IL-15–IL-15Rα complexes are induced during inflammation, but membrane-bound IL-15–IL-15Rα complexes, rather than soluble complexes, support NK cell activation in vitro and in vivo. Finally, we provide in vivo evidence that expression of IL-15Rα specifically on DCs is critical for trans presenting IL-15 and activating NK cells. These studies define an unprecedented cytokine–receptor biosynthetic pathway in which IL-15Rα serves as a chaperone for IL-15, after which membrane-bound IL-15Rα–IL-15 complexes activate NK cells via direct cell–cell contact.


2021 ◽  
Vol 12 ◽  
Author(s):  
Hemant K. Mishra ◽  
Kate J. Dixon ◽  
Nabendu Pore ◽  
Martin Felices ◽  
Jeffrey S. Miller ◽  
...  

Natural killer (NK) cells are innate cytotoxic lymphocytes that can recognize assorted determinants on tumor cells and rapidly kill these cells. Due to their anti-tumor effector functions and potential for allogeneic use, various NK cell platforms are being examined for adoptive cell therapies. However, their limited in vivo persistence is a current challenge. Cytokine-mediated activation of these cells is under extensive investigation and interleukin-15 (IL-15) is a particular focus since it drives their activation and proliferation. IL-15 efficacy though is limited in part by its induction of regulatory checkpoints. A disintegrin and metalloproteinase-17 (ADAM17) is broadly expressed by leukocytes, including NK cells, and it plays a central role in cleaving cell surface receptors, a process that regulates cell activation and cell-cell interactions. We report that ADAM17 blockade with a monoclonal antibody markedly increased human NK cell proliferation by IL-15 both in vitro and in a xenograft mouse model. Blocking ADAM17 resulted in a significant increase in surface levels of the homing receptor CD62L on proliferating NK cells. We show that NK cell proliferation in vivo by IL-15 and the augmentation of this process upon blocking ADAM17 are dependent on CD62L. Hence, our findings reveal for the first time that ADAM17 activation in NK cells by IL-15 limits their proliferation, presumably functioning as a feedback system, and that its substrate CD62L has a key role in this process in vivo. ADAM17 blockade in combination with IL-15 may provide a new approach to improve NK cell persistence and function in cancer patients.


2021 ◽  
Vol 218 (5) ◽  
Author(s):  
Maria Ferez ◽  
Cory J. Knudson ◽  
Avital Lev ◽  
Eric B. Wong ◽  
Pedro Alves-Peixoto ◽  
...  

Natural killer (NK) cell activation depends on the signaling balance of activating and inhibitory receptors. CD94 forms inhibitory receptors with NKG2A and activating receptors with NKG2E or NKG2C. We previously demonstrated that CD94-NKG2 on NK cells and its ligand Qa-1b are important for the resistance of C57BL/6 mice to lethal ectromelia virus (ECTV) infection. We now show that NKG2C or NKG2E deficiency does not increase susceptibility to lethal ECTV infection, but overexpression of Qa-1b in infected cells does. We also demonstrate that Qa-1b is down-regulated in infected and up-regulated in bystander inflammatory monocytes and B cells. Moreover, NK cells activated by ECTV infection kill Qa-1b–deficient cells in vitro and in vivo. Thus, during viral infection, recognition of Qa-1b by activating CD94/NKG2 receptors is not critical. Instead, the levels of Qa-1b expression are down-regulated in infected cells but increased in some bystander immune cells to respectively promote or inhibit their killing by activated NK cells.


2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 9521-9521
Author(s):  
H. N. Lode ◽  
Y. Zeng ◽  
S. Fest ◽  
G. Gaedicke

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.


2020 ◽  
Vol 9 (8) ◽  
pp. 2666
Author(s):  
Gustavo R. Rossi ◽  
Jenifer P. Gonçalves ◽  
Timothy McCulloch ◽  
Rebecca B. Delconte ◽  
Robert J. Hennessy ◽  
...  

Natural killer (NK) cells are innate lymphocytes responsible for the elimination of infected or transformed cells. The activation or inhibition of NK cells is determined by the balance of target cell ligand recognition by stimulatory and inhibitory receptors on their surface. Previous reports have suggested that the glycosaminoglycan heparin is a ligand for the natural cytotoxicity receptors NKp30, NKp44 (human), and NKp46 (both human and mouse). However, the effects of heparin on NK cell homeostasis and function remain unclear. Here, we show that heparin does not enhance NK cell proliferation or killing through NK cell activation. Alternatively, in mice models, heparin promoted NK cell survival in vitro and controlled B16-F10 melanoma metastasis development in vivo. In human NK cells, heparin promisingly increased interferon (IFN)-γ production in synergy with IL-12, although the mechanism remains elusive. Our data showed that heparin is not able to increase NK cell cytotoxicity.


2007 ◽  
Vol 204 (4) ◽  
pp. 893-906 ◽  
Author(s):  
Ulrike Schleicher ◽  
Jan Liese ◽  
Ilka Knippertz ◽  
Claudia Kurzmann ◽  
Andrea Hesse ◽  
...  

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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