Memory-like IFN-γ response by NK cells following malaria infection reveals the crucial role of T cells in NK cell activation by P. falciparum

2010 ◽  
Vol 40 (12) ◽  
pp. 3472-3477 ◽  
Author(s):  
Matthew B. B. McCall ◽  
Meta Roestenberg ◽  
Ivo Ploemen ◽  
Anne Teirlinck ◽  
Joost Hopman ◽  
...  
mBio ◽  
2017 ◽  
Vol 8 (4) ◽  
Author(s):  
Vivian Vasconcelos Costa ◽  
Weijian Ye ◽  
Qingfeng Chen ◽  
Mauro Martins Teixeira ◽  
Peter Preiser ◽  
...  

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.


Blood ◽  
2006 ◽  
Vol 107 (4) ◽  
pp. 1342-1351 ◽  
Author(s):  
Zusen Fan ◽  
Ping Yu ◽  
Yang Wang ◽  
Yugang Wang ◽  
May Lynne Fu ◽  
...  

Natural killer (NK) cells are generally reported as innate effector cells for killing virally infected and transformed cells. It is unclear how NK cells evoke adaptive immunity to eradicate tumors. We now demonstrate that the TNF superfamily member, LIGHT, known as TNFSF14 and a T-cell costimulatory molecule, is a critical ligand for the activation of NK cells. Herpesvirus entry mediator (HVEM) is expressed on NK cells, and its engagement with LIGHT mediates NK-cell activation. The expression of LIGHT inside tumors leads to rapid rejection in a NK-dependent manner. Both NK and CD8+ cells are essential but not sufficient for the rejection of tumors because mice lacking either population fail to reject the tumor. Interestingly, activated NK cells do not kill tumors directly but can facilitate the priming of tumor-specific CD8+ T cells in an IFN-γ–dependent manner. Conversely, intratumor depletion of either NK cells or IFN-γ during tumor progression disrupts CD8+ cell–mediated tumor rejection, suggesting that the tumor is the essential site for the crosstalk between NK and CD8+ cells. Furthermore, IFNG-deficient NK cells fail to effectively activate CD8+ T cells, suggesting IFN-γ plays an important role in NK-mediated activation of cytotoxic T lymphocytes (CTLs). Our findings establish a direct role for LIGHT in NK activation/expansion and a critical helper role of activated NK cells in priming CD8+ T cells and breaking T-cell tolerance at the tumor site.


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.


1997 ◽  
Vol 186 (12) ◽  
pp. 1957-1963 ◽  
Author(s):  
Noriko Arase ◽  
Hisashi Arase ◽  
Seung Yong Park ◽  
Hiroshi Ohno ◽  
Chisei Ra ◽  
...  

Natural killer (NK) cells exhibit cytotoxicity against variety of tumor cells and virus-infected cells without prior sensitization and represent unique lymphocytes involved in primary host defense. NKR-P1 is thought to be one of NK receptors mediating activation signals because cross-linking of NKR-P1 activates NK cells to exhibit cytotoxicity and IFN-γ production. However, molecular mechanism of NK cell activation via NKR-P1 is not well elucidated. In this study, we analyzed the cell surface complex associated with NKR-P1 on NK cells and found that NKR-P1 associates with the FcRγ chain which is an essential component of Fc receptors for IgG and IgE. The association between FcRγ and NKR-P1 is independent of Fc receptor complexes. Furthermore, NK cells from FcRγ-deficient mice did not show cytotoxicity or IFN-γ production upon NKR-P1 cross-linking. Similarly, NK1.1+ T cells from FcRγ-deficient mice did not produce IFN-γ upon NKR-P1 crosslinking. These findings demonstrate that the FcRγ chain plays an important role in activation of NK cells via the NKR-P1 molecule.


Author(s):  
Yan Yan ◽  
Wei Zhao ◽  
Wei Liu ◽  
Yan Li ◽  
Xu Wang ◽  
...  

Abstract Background Chemokine (C–C motif) ligand 19 (CCL19) is a leukocyte chemoattractant that plays a crucial role in cell trafficking and leukocyte activation. Dysfunctional CD8+ T cells play a crucial role in persistent HBV infection. However, whether HBV can be cleared by CCL19-activated immunity remains unclear. Methods We assessed the effects of CCL19 on the activation of PBMCs in patients with HBV infection. We also examined how CCL19 influences HBV clearance and modulates HBV-responsive T cells in a mouse model of chronic hepatitis B (CHB). In addition, C–C chemokine-receptor type 7 (CCR7) knockdown mice were used to elucidate the underlying mechanism of CCL19/CCR7 axis-induced immune activation. Results From in vitro experiments, we found that CCL19 enhanced the frequencies of Ag-responsive IFN-γ+ CD8+ T cells from patients by approximately twofold, while CCR7 knockdown (LV-shCCR7) and LY294002 partially suppressed IFN-γ secretion. In mice, CCL19 overexpression led to rapid clearance of intrahepatic HBV likely through increased intrahepatic CD8+ T-cell proportion, decreased frequency of PD-1+ CD8+ T cells in blood and compromised suppression of hepatic APCs, with lymphocytes producing a significantly high level of Ag-responsive TNF-α and IFN-γ from CD8+ T cells. In both CCL19 over expressing and CCR7 knockdown (AAV-shCCR7) CHB mice, the frequency of CD8+ T-cell activation-induced cell death (AICD) increased, and a high level of Ag-responsive TNF-α and low levels of CD8+ regulatory T (Treg) cells were observed. Conclusions Findings in this study provide insights into how CCL19/CCR7 axis modulates the host immune system, which may promote the development of immunotherapeutic strategies for HBV treatment by overcoming T-cell tolerance.


2021 ◽  
Vol 12 ◽  
Author(s):  
Elena Gianchecchi ◽  
Domenico V. Delfino ◽  
Alessandra Fierabracci

Autoimmune diseases recognize a multifactorial pathogenesis, although the exact mechanism responsible for their onset remains to be fully elucidated. Over the past few years, the role of natural killer (NK) cells in shaping immune responses has been highlighted even though their involvement is profoundly linked to the subpopulation involved and to the site where such interaction takes place. The aberrant number and functionality of NK cells have been reported in several different autoimmune disorders. In the present review, we report the most recent findings regarding the involvement of NK cells in both systemic and organ-specific autoimmune diseases, including type 1 diabetes (T1D), primary biliary cholangitis (PBC), systemic sclerosis, systemic lupus erythematosus (SLE), primary Sjögren syndrome, rheumatoid arthritis, and multiple sclerosis. In T1D, innate inflammation induces NK cell activation, disrupting the Treg function. In addition, certain genetic variants identified as risk factors for T1D influenced the activation of NK cells promoting their cytotoxic activity. The role of NK cells has also been demonstrated in the pathogenesis of PBC mediating direct or indirect biliary epithelial cell destruction. NK cell frequency and number were enhanced in both the peripheral blood and the liver of patients and associated with increased NK cell cytotoxic activity and perforin expression levels. NK cells were also involved in the perpetuation of disease through autoreactive CD4 T cell activation in the presence of antigen-presenting cells. In systemic sclerosis (SSc), in addition to phenotypic abnormalities, patients presented a reduction in CD56hi NK-cells. Moreover, NK cells presented a deficient killing activity. The influence of the activating and inhibitory killer cell immunoglobulin-like receptors (KIRs) has been investigated in SSc and SLE susceptibility. Furthermore, autoantibodies to KIRs have been identified in different systemic autoimmune conditions. Because of its role in modulating the immune-mediated pathology, NK subpopulation could represent a potential marker for disease activity and target for therapeutic intervention.


Blood ◽  
2009 ◽  
Vol 114 (15) ◽  
pp. 3227-3234 ◽  
Author(s):  
Hélène Beuneu ◽  
Jacques Deguine ◽  
Béatrice Breart ◽  
Ofer Mandelboim ◽  
James P. Di Santo ◽  
...  

Abstract During infection, Toll-like receptor agonists induce natural killer (NK)–cell activation by stimulating dendritic cells (DCs) to produce cytokines and transpresent IL-15 to NK cells. Yet the cellular dynamics underlying NK-cell activation by DCs in secondary lymphoid organs are largely unknown. Here, we have visualized NK-cell activation using mice in which NK cells and DCs express different fluorescent proteins. In response to polyI:C or lipopolysaccharide, NK cells maintained a vigorous migratory behavior, establishing multiple short contacts with maturing DCs. Furthermore, mature antigen-loaded DCs that made long-lived interactions with T cells formed short-lived contacts with NK cells. The different behaviors of T cells and NK cells during activation was correlated with distinct calcium responses upon interaction with DCs. That NK cells become activated while remaining motile may constitute an efficient strategy for sampling local concentrations of cytokines around DCs in secondary lymphoid tissues.


2005 ◽  
Vol 18 (2) ◽  
pp. 269-276 ◽  
Author(s):  
F. Martini ◽  
C. Agrati ◽  
G. D'Offizi ◽  
F. Poccia

Alterations in NK cell numbers and function have been repeatedly shown during HIV infection. In this study, NK cell number and MHC class I expression on CD4+ T cells were studied in HIV patients at different stages of disease progression. An increased expression of HLA-E was seen on CD4+ T cells. In parallel, a reduced number of CD94+ NK cells was observed in advanced disease stages. Moreover, a decline in CD94 expression on NK cells was observed at the HIV replication peak in patients undergoing antiretroviral treatment interruption, suggesting a role of viral replication on NK cells alterations. In vitro HIV infection induced a rapid down-regulation of HLA-A,B,C expression, paralleled by an increased expression of HLA-E surface molecules, the formal ligands of CD94 NK receptors. HIV-infected HLA-E expressing cells were able to inhibit NK cell cytotoxicity through HLA-E expression, since cytotoxicity was restored by antibody masking experiments. These data indicate that the CD94/HLA-E interaction may contribute to NK cell dysfunction in HIV infection, suggesting a role of HIV replication in this process.


2020 ◽  
Vol 55 (5) ◽  
pp. 1802422
Author(s):  
Justine Devulder ◽  
Cécile Chenivesse ◽  
Valérie Ledroit ◽  
Stéphanie Fry ◽  
Pierre-Emmanuel Lobert ◽  
...  

Rhinovirus infections are the main cause of asthma exacerbations. As natural killer (NK) cells are important actors of the antiviral innate response, we aimed at evaluating the functions of NK cells from severe asthma patients in response to rhinovirus-like molecules or rhinoviruses.Peripheral blood mononuclear cells from patients with severe asthma and healthy donors were stimulated with pathogen-like molecules or with the rhinoviruses (RV)-A9 and RV-2. NK cell activation, degranulation and interferon (IFN)-γ expression were analysed.NK cells from severe asthma patients were less cytotoxic than those from healthy donors in response to toll-like receptor (TLR)3, TLR7/8 or RV-A9 but not in response to RV-2 stimulation. Furthermore, when cultured with interleukin (IL)-12+IL-15, cytokines which are produced during viral infections, NK cells from patients with severe asthma were less cytotoxic and expressed less IFN-γ than NK cells from healthy donors. NK cells from severe asthmatics exhibited an exhausted phenotype, with an increased expression of the checkpoint molecule Tim-3.Together, our findings indicate that the activation of NK cells from patients with severe asthma may be insufficient during some but not all respiratory infections. The exhausted phenotype may participate in NK cell impairment and aggravation of viral-induced asthma exacerbation in these patients.


Cancers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2171
Author(s):  
Isabel Valhondo ◽  
Fakhri Hassouneh ◽  
Nelson Lopez-Sejas ◽  
Alejandra Pera ◽  
Beatriz Sanchez-Correa ◽  
...  

Background: Acute myeloid leukemia (AML) remains a major clinical challenge due to poor overall survival, which is even more dramatic in elderly patients. TIGIT, an inhibitory receptor that interacts with CD155 and CD112 molecules, is considered as a checkpoint in T and NK cell activation. This receptor shares ligands with the co-stimulatory receptor DNAM-1 and with TACTILE. The aim of this work was to analyze the expression of DNAM-1, TIGIT and TACTILE in NK cells and T cell subsets in AML patients. Methods: We have studied 36 patients at the time of diagnosis of AML and 20 healthy volunteers. The expression of DNAM-1, TIGIT and TACTILE in NK cells and T cells, according to the expression of CD3 and CD56, was performed by flow cytometry. Results: NK cells, CD56− T cells and CD56+ T (NKT-like) cells from AML patients presented a reduced expression of DNAM-1 compared with healthy volunteers. An increased expression of TIGIT was observed in mainstream CD56− T cells. No differences were observed in the expression of TACTILE. Simplified presentation of incredibly complex evaluations (SPICE) analysis of the co-expression of DNAM-1, TIGIT and TACTILE showed an increase in NK and T cells lacking DNAM-1 and co-expressing TIGIT and TACTILE. Low percentages of DNAM-1−TIGIT+TACTILE+ NK cells and DNAM-1− TIGIT+TACTILE+ CD56− T cells were associated with a better survival of AML patients. Conclusions: The expression of DNAM-1 is reduced in NK cells and in CD4+ and CD8+ T cells from AML patients compared with those from healthy volunteers. An increased percentage of NK and T cells lacking DNAM-1 and co-expressing TIGIT and TACTILE is associated with patient survival, supporting the role of TIGIT as a novel candidate for checkpoint blockade.


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