Molecular basis for positive and negative signaling by the natural killer cell receptor 2B4 (CD244)

Blood ◽  
2005 ◽  
Vol 105 (12) ◽  
pp. 4722-4729 ◽  
Author(s):  
Philipp Eissmann ◽  
Lisa Beauchamp ◽  
Joe Wooters ◽  
John C. Tilton ◽  
Eric O. Long ◽  
...  

Abstract Triggering of 2B4 (CD244) can induce natural killer (NK)-cell activation, costimulation, or even inhibition of NK-cell activity. Here, we investigate the molecular basis for the different signals generated by 2B4. We show that the first immunoreceptor tyrosine-based switch motif (ITSM) within the cytoplasmic tail of 2B4 is sufficient for 2B4-mediated NK-cell activation, whereas the third ITSM can negatively influence 2B4 signaling. We further identify signaling molecules that associate with 2B4. Signaling lymphocyte activation molecule-associated protein (SAP) can bind to all 4 ITSMs of 2B4 in a phosphorylation-dependent manner. The phosphorylated third ITSM can additionally recruit the phosphatases SHP-1, SHP-2, SHIP, and the inhibitory kinase Csk. SAP acts as an inhibitor of interactions between 2B4 and these negative regulatory molecules, explaining how 2B4 inhibits NK-cell activation in the absence of functional SAP, as occurs in cells from patients with X-linked lymphoproliferative syndrome (XLP). Recently, another function for SAP was proposed: SAP can recruit the kinase Fyn to the SLAM (CD150) immune receptor. We now show that Fyn can also associate with phosphorylated 2B4. Finally, we demonstrate that Fyn and Csk can both phosphorylate 2B4, suggesting a possible mechanism of 2B4 phosphorylation. (Blood. 2005;105:4722-4729)

2019 ◽  
Vol 116 (35) ◽  
pp. 17409-17418 ◽  
Author(s):  
Xuefu Wang ◽  
Rui Sun ◽  
Xiaolei Hao ◽  
Zhe-Xiong Lian ◽  
Haiming Wei ◽  
...  

Increasing evidence demonstrates that IL-17A promotes tumorigenesis, metastasis, and viral infection. Natural killer (NK) cells are critical for defending against tumors and infections. However, the roles and mechanisms of IL-17A in regulating NK cell activity remain elusive. Herein, our study demonstrated that IL-17A constrained NK cell antitumor and antiviral activity by restraining NK cell maturation. It was observed that the development and metastasis of tumors were suppressed in IL-17A–deficient mice in the NK cell-dependent manner. In addition, the antiviral activity of NK cells was also improved in IL-17A–deficient mice. Mechanistically, ablation of IL-17A signaling promoted generation of terminally mature CD27−CD11b+ NK cells, whereas constitutive IL-17A signaling reduced terminally mature NK cells. Parabiosis or mixed bone marrow chimeras from Il17a−/−and wild-type (WT) mice could inhibit excessive generation of terminally mature NK cells induced by IL-17A deficiency. Furthermore, IL-17A desensitized NK cell responses to IL-15 and suppressed IL-15–induced phosphorylation of signal transducer and activator of transcription 5 (STAT5) via up-regulation of SOCS3, leading to down-regulation of Blimp-1. Therefore, IL-17A acts as the checkpoint during NK cell terminal maturation, which highlights potential interventions to defend against tumors and viral infections.


2005 ◽  
Vol 202 (8) ◽  
pp. 1075-1085 ◽  
Author(s):  
François Ghiringhelli ◽  
Cédric Ménard ◽  
Magali Terme ◽  
Caroline Flament ◽  
Julien Taieb ◽  
...  

Tumor growth promotes the expansion of CD4+CD25+ regulatory T (T reg) cells that counteract T cell–mediated immune responses. An inverse correlation between natural killer (NK) cell activation and T reg cell expansion in tumor-bearing patients, shown here, prompted us to address the role of T reg cells in controlling innate antitumor immunity. Our experiments indicate that human T reg cells expressed membrane-bound transforming growth factor (TGF)–β, which directly inhibited NK cell effector functions and down-regulated NKG2D receptors on the NK cell surface. Adoptive transfer of wild-type T reg cells but not TGF-β−/− T reg cells into nude mice suppressed NK cell–mediated cytotoxicity, reduced NKG2D receptor expression, and accelerated the growth of tumors that are normally controlled by NK cells. Conversely, the depletion of mouse T reg cells exacerbated NK cell proliferation and cytotoxicity in vivo. Human NK cell–mediated tumor recognition could also be restored by depletion of T reg cells from tumor-infiltrating lymphocytes. These findings support a role for T reg cells in blunting the NK cell arm of the innate immune system.


2007 ◽  
Vol 204 (12) ◽  
pp. 3027-3036 ◽  
Author(s):  
Galit Alter ◽  
Maureen P. Martin ◽  
Nickolas Teigen ◽  
William H. Carr ◽  
Todd J. Suscovich ◽  
...  

Decline of peak viremia during acute HIV-1 infection occurs before the development of vigorous adaptive immunity, and the level of decline correlates inversely with the rate of AIDS progression, implicating a potential role for the innate immune response in determining disease outcome. The combined expression of an activating natural killer (NK) cell receptor, the killer immunoglobulin-like receptor (KIR) 3DS1, and its presumed ligand, human leukocyte antigen (HLA)–B Bw4-80I, has been associated in epidemiological studies with a slow progression to AIDS. We examined the functional ability of NK cells to differentially control HIV-1 replication in vitro based on their KIR and HLA types. NK cells expressing KIR3DS1 showed strong, significant dose- and cell contact–dependent inhibition of HIV-1 replication in target cells expressing HLA-B Bw4-80I compared with NK cells that did not express KIR3DS1. Furthermore, KIR3DS1+ NK cells and NKLs were preferentially activated, and lysed HIV-1 infected target cells in an HLA-B Bw4-80I–dependent manner. These data provide the first functional evidence that variation at the KIR locus influences the effectiveness of NK cell activity in the containment of viral replication.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Kazuyoshi Takeda ◽  
Ko Okumura

Panax ginsengextracts are used in traditional herbal medicines, particularly in eastern Asia, but their effect on natural killer (NK) cell activity is not completely understood. This study aimed to examine the effects ofP. ginsengextracts on the cytotoxic activity of NK cells. We orally administeredP. ginsengextracts or ginsenosides to wild-type (WT) C57BL/6 (B6) and BALB/c mice and to B6 mice deficient in either recombination activating gene 2 (RAG-2) or interferon-γ(IFN-γ). We then tested the cytotoxic activity of NK cells (of spleen and liver mononuclear cells) against NK-sensitive YAC-1 cells. Oral administration ofP. ginsengaqueous extract augmented the cytotoxicity of NK cells in WT B6 and BALB/c mice and in RAG-2-deficient B6 mice, but not in IFN-γ-deficient B6 mice. This effect was only observed with the aqueous extract ofP. ginseng. Interestingly, the ginsenosides Rb1 and Rg1 did not augment NK cell cytotoxicity. These results demonstrated that the aqueousP. ginsengextract augmented NK cell activationin vivovia an IFN-γ-dependent pathway.


2010 ◽  
Vol 207 (12) ◽  
pp. 2663-2673 ◽  
Author(s):  
Marina Babić ◽  
Michal Pyzik ◽  
Biljana Zafirova ◽  
Maja Mitrović ◽  
Višnja Butorac ◽  
...  

Cytomegaloviruses (CMVs) are renowned for interfering with the immune system of their hosts. To sidestep antigen presentation and destruction by CD8+ T cells, these viruses reduce expression of major histocompatibility complex class I (MHC I) molecules. However, this process sensitizes the virus-infected cells to natural killer (NK) cell–mediated killing via the “missing self” axis. Mouse cytomegalovirus (MCMV) uses m152 and m06 encoded proteins to inhibit surface expression of MHC I molecules. In addition, it encodes another protein, m04, which forms complexes with MHC I and escorts them to the cell surface. This mechanism is believed to prevent NK cell activation and killing by restoring the “self” signature and allowing the engagement of inhibitory Ly49 receptors on NK cells. Here we show that MCMV lacking m04 was attenuated in an NK cell– and MHC I–dependent manner. NK cell–mediated control of the infection was dependent on the presence of NK cell subsets expressing different inhibitory Ly49 receptors. In addition to providing evidence for immunoevasion strategies used by CMVs to avoid NK cell control via the missing-self pathway, our study is the first to demonstrate that missing self–dependent NK cell activation is biologically relevant in the protection against viral infection in vivo.


2020 ◽  
Author(s):  
Manchao Zhang ◽  
Scarlett Acklin ◽  
John Gillenwater ◽  
Wuying Du ◽  
Mousumi Patra ◽  
...  

Abstract SIRT2, an NAD+-dependent histone deacetylase, has been shown to play a pivotal role in various physiological processes, however, its role in cancer is currently controversial. In recent years, SIRT2 has been described as both a tumor suppressor and oncogene with divergent expression and function in various malignancies. Using murine xenograft melanoma models, our results suggest increased systemic expression of SIRT2 promotes tumor progression. In this study, SIRT2-overexpressing mice exhibited enhanced tumor growth and larger tumor volumes compared to their wild-type littermates. Mechanistically, systemic overexpression of SIRT2 reduces the number of tumor-infiltrating natural killer (NK) cells and suppresses NK cell activation and proliferation within the tumor microenvironment (TME). Furthermore, despite the effect of increased tumor growth rate and tumor volume in wild-type littermate mice, NK cell depletion does not affect that in SIRT2-overexpressing mice. Lastly, pharmacological inhibition of SIRT2 increases NK cell tumor infiltration and suppresses melanoma tumor growth in mice. The findings of this study identify a dynamic functional interaction between systemic SIRT2 and NK cell activity, which promotes melanoma tumor progression. Given the recent renewed interest in NK-cell-mediated immunotherapy response, SIRT2 could present a new opportunity to mediate immunotherapy response and resistance.


Blood ◽  
2004 ◽  
Vol 104 (9) ◽  
pp. 2858-2866 ◽  
Author(s):  
Yanmei Han ◽  
Minghui Zhang ◽  
Nan Li ◽  
Taoyong Chen ◽  
Yi Zhang ◽  
...  

Abstract Natural killer (NK) cell inhibitory receptors play important roles in the regulation of target susceptibility to natural killing. Here, we report the molecular cloning and functional characterization of a novel NK cell receptor, KLRL1, from human and mouse dendritic cells. KLRL1 is a type II transmembrane protein with an immunoreceptor tyrosine-based inhibitory motif and a C-type lectinlike domain. The KLRL1 gene is located in the central region of the NK gene complex in both humans and mice, on human chromosome 12p13 and mouse chromosome 6F3, adjacent to the other KLR genes. KLRL1 is preferentially expressed in lymphoid tissues and immune cells, including NK cells, T cells, dendritic cells, and monocytes or macrophages. Western blot and fluorescence confocal microscopy analyses indicated that KLRL1 is a membrane-associated glycoprotein, which forms a heterodimer with an as yet unidentified partner. Human and mouse KLRL1 are both predicted to contain putative immunoreceptor tyrosine-based inhibitory motifs (ITIMs), and immunoprecipitation experiments demonstrated that KLRL1 associates with the tyrosine phosphatases SHP-1 (SH2-domain-containing protein tyrosine phosphatase 1) and SHP-2. Consistent with its potential inhibitory function, pretreatment of target cells with human KLRL1-Fc fusion protein enhances NK-mediated cytotoxicity. Taken together, our results demonstrate that KLRL1 belongs to the KLR family and is a novel inhibitory NK cell receptor.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Yan Feng ◽  
Yan Li ◽  
Ying Zhang ◽  
Bo-Hao Zhang ◽  
Hui Zhao ◽  
...  

Abstract Background Brain ischemia compromises natural killer (NK) cell-mediated immune defenses by acting on neurogenic and intracellular pathways. Less is known about the posttranscriptional mechanisms that regulate NK cell activation and cytotoxicity after ischemic stroke. Methods Using a NanoString nCounter® miRNA array panel, we explored the microRNA (miRNA) profile of splenic NK cells in mice subjected to middle cerebral artery occlusion. Differential gene expression and function/pathway analysis were applied to investigate the main functions of predicted miRNA target genes. miR-1224 inhibitor/mimics transfection and passive transfer of NK cells were performed to confirm the impact of miR-1224 in NK cells after brain ischemia. Results We observed striking dysregulation of several miRNAs in response to ischemia. Among those miRNAs, miR-1224 markedly increased 3 days after ischemic stroke. Transfection of miR-1224 mimics into NK cells resulted in suppression of NK cell activity, while an miR-1224 inhibitor enhanced NK cell activity and cytotoxicity, especially in the periphery. Passive transfer of NK cells treated with an miR-1224 inhibitor prevented the accumulation of a bacterial burden in the lungs after ischemic stroke, suggesting an enhanced immune defense of NK cells. The transcription factor Sp1, which controls cytokine/chemokine release by NK cells at the transcriptional level, is a predicted target of miR-1224. The inhibitory effect of miR-1224 on NK cell activity was blocked in Sp1 knockout mice. Conclusions These findings indicate that miR-1224 may serve as a negative regulator of NK cell activation in an Sp1-dependent manner; this mechanism may be a novel target to prevent poststroke infection specifically in the periphery and preserve immune defense in the brain.


2000 ◽  
Vol 124 (10) ◽  
pp. 1510-1513 ◽  
Author(s):  
Paulette Mhawech ◽  
L. Jeffrey Medeiros ◽  
Carlos Bueso-Ramos ◽  
Donna M. Coffey ◽  
Alfredo F. Gei ◽  
...  

Abstract Non-Hodgkin lymphomas (NHL) can involve the gynecologic tract, most often as a manifestation of systemic involvement, and most cases reported have been of B-cell lineage. We describe 2 women with natural killer (NK)-cell lymphoma involving the gynecologic tract that initially presented with vaginal bleeding. In case 1, the patient had a stage IE nasal-type NK-cell lymphoma involving the cervix. The tumor was composed of medium-sized, irregular lymphoid cells with angioinvasion and necrosis. In case 2, the patient had a stage IV blastoid NK-cell lymphoma/leukemia infiltrating all organs in a hysterectomy and bilateral salpingo-oophorectomy specimen. Subsequent biopsy specimens revealed that the bone marrow and lymph nodes were also involved. The neoplasm was composed of small to medium lymphoid cells with fine nuclear chromatin. Case 1 was assessed immunohistochemically and the neoplastic cells were positive for CD3, CD56, and TIA-1. Case 2 was analyzed using both immunohistochemical and flow cytometry methods. The neoplastic cells were positive for cytoplasmic CD3, CD4, CD7, CD43, CD45, and CD56 and were negative for surface CD3. Both cases were negative for Epstein-Barr virus (EBV) ribonucleic acid (RNA) and molecular studies showed no evidence of T-cell receptor γ chain gene rearrangements. The immunophenotype and absence of T-cell receptor gene rearrangements support NK-cell origin. We report these cases to illustrate that NK-cell lymphomas can involve, and rarely arise in, the gynecologic tract.


Hypertension ◽  
2021 ◽  
Vol 78 (Suppl_1) ◽  
Author(s):  
Sarah J Fitzgerald ◽  
James Hogg ◽  
Evangeline Deer ◽  
Nathan Campbell ◽  
Owen Herrock ◽  
...  

Preeclampsia (PE) is characterized by new onset hypertension (HTN), intrauterine growth restriction (IUGR), multi-organ dysfunction, and is associated with increased inflammatory cytokines, such as interleukin 17 (IL-17). More recent studies demonstrate a role for mitochondrial (mt) dysfunction/mtROS in the pathogenesis of PE. Although we have shown T helper cells from a rat model of PE cause HTN and mt dysfunction the causative factors for mt dysfunction are still being identified. In addition, we have shown that IL-17 cause HTN, IUGR and activate natural killer (NK) cells, and cause mt dysfunction in pregnant Sprague Dawley rats. However, in our previous studies we couldn’t differentiate the effect of activated TH cells versus IL-17 to cause these characteristics of PE. The athymic nude rat model lacks mature T cells but does have other components of the immune system, and will thus allow us to examine the role of IL-17 in the absence of TH cells in the pathophysiology of PE. We hypothesize that in the absence of T cells IL-17 induces HTN, NK cell activation and IUGR which is associated with renal and placental mt dysfunction during pregnancy. To test our hypothesis, IL-17 (150 pg/day) was infused via osmotic minipumps inserted on gestation day (GD) 14. Blood pressure (MAP) and mt function were measured on GD19 and were compared to untreated pregnant (NP) athymic nude rats. In response to IL-17; MAP increased from 95±4mmHg in NP(n=6) to 115±2 in NP+IL-17(n=6) (p<0.001); pup weight decreased from 1.46±0.2 g in NP (n=6) to 0.98±0.07g in NP+IL-17 (n=6) (p<0.05); NK cell activation increased from 0±0 %lymphocytes in NP (n=3) to 0.4±0.1% lymphocytes in NP+IL-17 rats (n=6). Interestingly, placental mtROS reduced 54% fold compared to NP and renal mtROS reduced 51.2% compared to NP. ATP production increased from 15.53±1.6 pmol of O2/sec/mg in NP (n=3) to 105.5±91 pmol of O2/sec/mg in NP+IL-17 (n=3) in the placenta, and from 1196±460 pmol of O2/sec/mg in NP (n=4) to 2016±951 pmol of O2/sec/mg NP+IL17 (n=4) in the kidney. These results show that although IL-17 induces HTN, IUGR, and NK cell activation independent of T cells, T cells are necessary for reduced mitochondrial function observed in PE and in rat models of placental ischemia.


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