scholarly journals Functional Dichotomy in Natural Killer Cell Signaling

2001 ◽  
Vol 193 (12) ◽  
pp. 1413-1424 ◽  
Author(s):  
Francesco Colucci ◽  
Eleftheria Rosmaraki ◽  
Søren Bregenholt ◽  
Sandrine I. Samson ◽  
Vincenzo Di Bartolo ◽  
...  

The product of the protooncogene Vav1 participates in multiple signaling pathways and is a critical regulator of antigen–receptor signaling in B and T lymphocytes, but its role during in vivo natural killer (NK) cell differentiation is not known. Here we have studied NK cell development in Vav1−/− mice and found that, in contrast to T and NK-T cells, the absolute numbers of phenotypically mature NK cells were not reduced. Vav1−/− mice produced normal amounts of interferon (IFN)-γ in response to Listeria monocytogenes and controlled early infection but showed reduced tumor clearance in vivo. In vitro stimulation of surface receptors in Vav1−/− NK cells resulted in normal IFN-γ production but reduced tumor cell lysis. Vav1 was found to control activation of extracellular signal-regulated kinases and exocytosis of cytotoxic granules. In contrast, conjugate formation appeared to be only mildly affected, and calcium mobilization was normal in Vav1−/− NK cells. These results highlight fundamental differences between proximal signaling events in T and NK cells and suggest a functional dichotomy for Vav1 in NK cells: a role in cytotoxicity but not for IFN-γ production.

Blood ◽  
2011 ◽  
Vol 117 (17) ◽  
pp. 4511-4518 ◽  
Author(s):  
Katrina Soderquest ◽  
Nick Powell ◽  
Carmelo Luci ◽  
Nico van Rooijen ◽  
Andrés Hidalgo ◽  
...  

Abstract Natural killer (NK) cells play a major role in immunologic surveillance of cancer. Whether NK-cell subsets have specific roles during antitumor responses and what the signals are that drive their terminal maturation remain unclear. Using an in vivo model of tumor immunity, we show here that CD11bhiCD27low NK cells migrate to the tumor site to reject major histocompatibility complex class I negative tumors, a response that is severely impaired in Txb21−/− mice. The phenotypical analysis of Txb21-deficient mice shows that, in the absence of Txb21, NK-cell differentiation is arrested specifically at the CD11bhiCD27hi stage, resulting in the complete absence of terminally differentiated CD11bhiCD27low NK cells. Adoptive transfer experiments and radiation bone marrow chimera reveal that a Txb21+/+ environment rescues the CD11bhiCD27hi to CD11bhiCD27low transition of Txb21−/− NK cells. Furthermore, in vivo depletion of myeloid cells and in vitro coculture experiments demonstrate that spleen monocytes mediate the terminal differentiation of peripheral NK cells in a Txb21- and IL-15Rα–dependent manner. Together, these data reveal a novel, unrecognized role for Txb21 expression in monocytes in promoting NK-cell development and help appreciate how various NK-cell subsets are generated and participate in antitumor immunity.


Blood ◽  
1999 ◽  
Vol 93 (5) ◽  
pp. 1612-1621 ◽  
Author(s):  
Lei Yao ◽  
Cecilia Sgadari ◽  
Keizo Furuke ◽  
Eda T. Bloom ◽  
Julie Teruya-Feldstein ◽  
...  

Abstract Interleukin-12 (IL-12) inhibits angiogenesis in vivo by inducing interferon-γ (IFN-γ) and other downstream mediators. Here, we report that neutralization of natural killer (NK) cell function with antibodies to either asialo GM1 or NK 1.1 reversed IL-12 inhibition of basic fibroblast growth factor (bFGF)-induced angiogenesis in athymic mice. By immunohistochemistry, those sites where bFGF-induced neovascularization was inhibited by IL-12 displayed accumulation of NK cells and the presence of IP-10–positive cells. Based on expression of the cytolytic mediators perforin and granzyme B, the NK cells were locally activated. Experimental Burkitt lymphomas treated locally with IL-12 displayed tumor tissue necrosis, vascular damage, and NK-cell infiltration surrounding small vessels. After activation in vitro with IL-12, NK cells from nude mice became strongly cytotoxic for primary cultures of syngeneic aortic endothelial cells. Cytotoxicity was neutralized by antibodies to IFN-γ. These results document that NK cells are required mediators of angiogenesis inhibition by IL-12, and provide evidence that NK-cell cytotoxicity of endothelial cells is a potential mechanism by which IL-12 can suppress neovascularization.


Blood ◽  
2011 ◽  
Vol 118 (9) ◽  
pp. 2473-2482 ◽  
Author(s):  
Catharina H. M. J. Van Elssen ◽  
Joris Vanderlocht ◽  
Tammy Oth ◽  
Birgit L. M. G. Senden-Gijsbers ◽  
Wilfred T. V. Germeraad ◽  
...  

Abstract Among prostaglandins (PGs), PGE2 is abundantly expressed in various malignancies and is probably one of many factors promoting tumor growth by inhibiting tumor immune surveillance. In the current study, we report on a novel mechanism by which PGE2 inhibits in vitro natural killer–dendritic cell (NK-DC) crosstalk and thereby innate and adaptive immune responses via its effect on NK-DC crosstalk. The presence of PGE2 during IFN-γ/membrane fraction of Klebsiella pneumoniae DC maturation inhibits the production of chemokines (CCL5, CCL19, and CXCL10) and cytokines (IL-12 and IL-18), which is cAMP-dependent and imprinted during DC maturation. As a consequence, these DCs fail to attract NK cells and show a decreased capacity to trigger NK cell IFN-γ production, which in turn leads to reduced T-helper 1 polarization. In addition, the presence of PGE2 during DC maturation impairs DC-mediated augmentation of NK-cell cytotoxicity. Opposed to their inhibitory effects on peripheral blood–derived NK cells, PGE2 matured DCs induce IL-22 secretion of inflammation constraining NKp44+ NK cells present in mucosa-associated lymphoid tissue. The inhibition of NK-DC interaction is a novel regulatory property of PGE2 that is of possible relevance in dampening immune responses in vivo.


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.


2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Obinna Chijioke ◽  
Christian Münz

In both human and mouse it has been recently realized that natural killer (NK) cells do not emerge from the bone marrow with full functional competence but rather acquire functions in interaction with antigen-presenting cells (APCs), primarily dendritic cells (DCs). Here we review the mechanisms and the consequences of this NK-cell preactivation, as well as discuss new experimental models that now allow investigating these interactions for human NK cells and their response to human pathogens in vivo. These investigations will allow harnessing NK cells during vaccination for improved innate and adaptive immunity.


Reproduction ◽  
2009 ◽  
Vol 137 (6) ◽  
pp. 943-955 ◽  
Author(s):  
Yi Lin ◽  
Huiqi Wang ◽  
Wenjing Wang ◽  
Shan Zeng ◽  
Yanmin Zhong ◽  
...  

Both regulatory T cells and regulatory natural killer (NK) cells may play essential roles in the maintenance of pregnancy. In this study, we show that a significantly high percentage of spontaneous embryo loss was observed in both allogeneic and syngeneic pregnant non-obese diabetic (NOD) mice. The percentage of embryo loss in allogeneic pregnant mice was further increased by the administration of anti-asialo ganglio-N-tetraosylceramide to deplete NK cells, but was decreased by the adoptive transfer of ITGA2+ISG20+ (CD49b+ CD25+) NK cells from normal mice. No such trend was observed in syngeneic pregnant NOD mice. The pattern of CXCR4 (specific receptor for CXCL12) expression on NK cells was analyzed and NK-cell migration was confirmed by in vitro and in vivo migratory assays. Since CXCL12 production by murine trophoblast cells was confirmed previously, our findings suggest that the recruitment of peripheral CXCR4-expressing ITGA2+ISG20+ NK cells into pregnant uteri may be important in the regulation of feto-maternal tolerance.


Blood ◽  
1999 ◽  
Vol 93 (5) ◽  
pp. 1612-1621 ◽  
Author(s):  
Lei Yao ◽  
Cecilia Sgadari ◽  
Keizo Furuke ◽  
Eda T. Bloom ◽  
Julie Teruya-Feldstein ◽  
...  

Interleukin-12 (IL-12) inhibits angiogenesis in vivo by inducing interferon-γ (IFN-γ) and other downstream mediators. Here, we report that neutralization of natural killer (NK) cell function with antibodies to either asialo GM1 or NK 1.1 reversed IL-12 inhibition of basic fibroblast growth factor (bFGF)-induced angiogenesis in athymic mice. By immunohistochemistry, those sites where bFGF-induced neovascularization was inhibited by IL-12 displayed accumulation of NK cells and the presence of IP-10–positive cells. Based on expression of the cytolytic mediators perforin and granzyme B, the NK cells were locally activated. Experimental Burkitt lymphomas treated locally with IL-12 displayed tumor tissue necrosis, vascular damage, and NK-cell infiltration surrounding small vessels. After activation in vitro with IL-12, NK cells from nude mice became strongly cytotoxic for primary cultures of syngeneic aortic endothelial cells. Cytotoxicity was neutralized by antibodies to IFN-γ. These results document that NK cells are required mediators of angiogenesis inhibition by IL-12, and provide evidence that NK-cell cytotoxicity of endothelial cells is a potential mechanism by which IL-12 can suppress neovascularization.


2012 ◽  
Vol 209 (3) ◽  
pp. 565-580 ◽  
Author(s):  
Baptiste N. Jaeger ◽  
Jean Donadieu ◽  
Céline Cognet ◽  
Claire Bernat ◽  
Diana Ordoñez-Rueda ◽  
...  

Natural killer (NK) cells are bone marrow (BM)–derived granular lymphocytes involved in immune defense against microbial infections and tumors. In an N-ethyl N-nitrosourea (ENU) mutagenesis strategy, we identified a mouse mutant with impaired NK cell reactivity both in vitro and in vivo. Dissection of this phenotype showed that mature neutrophils were required both in the BM and in the periphery for proper NK cell development. In mice lacking neutrophils, NK cells displayed hyperproliferation and poor survival and were blocked at an immature stage associated with hyporesponsiveness. The role of neutrophils as key regulators of NK cell functions was confirmed in patients with severe congenital neutropenia and autoimmune neutropenia. In addition to their direct antimicrobial activity, mature neutrophils are thus endowed with immunoregulatory functions that are conserved across species. These findings reveal novel types of cooperation between cells of the innate immune system and prompt examination of NK cell functional deficiency in patients suffering from neutropenia-associated diseases.


Blood ◽  
2000 ◽  
Vol 95 (3) ◽  
pp. 984-991 ◽  
Author(s):  
Francesco Colucci ◽  
James P. Di Santo

Fetal liver kinase ligands (flk2L/flt3L) and stem cell factor (SCF) have been shown to promote natural killer (NK) cell differentiation from hematopoietic stem cell (HSC) precursors in vitro. However, the contribution of signaling through the receptors for these growth factors for in vivo NK cell development remains ill-defined. We have analyzed the role of the SCF receptor c-kit in NK cell differentiation by reconstituting NK-deficient mice with fetal liver (FL) HSCs of c-kit−/− (W/W) mice. Although c-kit−/−NK cells were generated inW/W chimeras, they were reduced in number, contained a lower percentage of CD45R (B220)+ cells, and were poorly cytolytic. In vitro experiments showed that generation of NK cells from FL precursors was reduced in the absence of c-kit signaling and that SCF promoted the survival of peripheral c-kit+ NK cells. We conclude that c-kit/SCF interactions in vivo are dispensable for the commitment of HSC to the NK lineage, but they provide essential signals for generating normal numbers of fully mature NK cells.


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