scholarly journals Strain-Specific Human Natural Killer Cell Recognition of Influenza A Virus

2017 ◽  
Author(s):  
Lisa M. Kronstad ◽  
Christof Seiler ◽  
Rosemary Vergara ◽  
Susan P. Holmes ◽  
Catherine A. Blish

AbstractInnate Natural killer (NK) cells employ an array of surface receptors to detect ‘altered self’ induced by infection or malignancy. Despite their decisive role in early antiviral immunity, the cellular mechanisms governing if or how they discriminate between viral infections remain unresolved. Here, we demonstrate that while human NK cells are capable of reducing infection levels of distinct influenza A strains, the A/California/07/2009 (pH1N1) strain induces a significantly more robust IFN-γ response than A/Victoria/361/2011 (H3N2) and all other strains tested. This surprising degree of strain specificity results in part from the inability of the pH1N1 strain to downregulate the activating ligands CD112 (Nectin-2) and CD54 (ICAM-1) as efficiently as the H3N2 strain, leading to enhanced NK cell detection and IFN-γ secretion. A network analysis of differentially expressed transcripts identifies the interferon α/β receptor (IFNAR) pathway as an additional, critical determinant of this strain-specific response. Strain-specific downregulation of NK cell activating ligands and modulation of type I IFN production represents a previously unrecognized influenza immunoevasion tactic and could present new opportunities to modulate the quality and quantity of the innate antiviral response for therapeutic benefit.One Sentence SummaryHuman natural killer cells distinguish between Influenza A strains using a combinatorial cytokine priming and receptor-ligand signaling mechanism.

2021 ◽  
Vol 12 ◽  
Author(s):  
Baige Yao ◽  
Qinglan Yang ◽  
Yao Yang ◽  
Yana Li ◽  
Hongyan Peng ◽  
...  

Natural killer (NK) cells are a potent weapon against tumor and viral infection. Finding active compounds with the capacity of enhancing NK cell effector functions will be effective to develop new anti-cancer drugs. In this study, we initially screened 287 commercially available active compounds by co-culturing with peripheral blood mononuclear cells (PBMCs). We found that five compounds, namely, Daphnetin, MK-8617, LW6, JIB-04, and IOX1, increased the IFN-γ+ NK cell ratio in the presence of IL-12. Further studies using purified human primary NK cells revealed that Daphnetin directly promoted NK cell IFN-γ production in the presence of IL-12 but not IL-15, while the other four compounds acted on NK cells indirectly. Daphnetin also improved the direct cytotoxicity of NK cells against tumor cells in the presence of IL-12. Through RNA-sequencing, we found that PI3K-Akt-mTOR signaling acted as a central pathway in Daphnetin-mediated NK cell activation in the presence of IL-12. This was further confirmed by the finding that both inhibitors of PI3K-Akt and its main downstream signaling mTOR, LY294002, and rapamycin, respectively, can reverse the increase of IFN-γ production and cytotoxicity in NK cells promoted by Daphnetin. Collectively, we identify a natural product, Daphnetin, with the capacity of promoting human NK cell activation via PI3K-Akt-mTOR signaling in the presence of IL-12. Our current study opens up a new potential application for Daphnetin as a complementary immunomodulator for cancer treatments.


Blood ◽  
2012 ◽  
Vol 119 (16) ◽  
pp. 3734-3743 ◽  
Author(s):  
Lishomwa C. Ndhlovu ◽  
Sandra Lopez-Vergès ◽  
Jason D. Barbour ◽  
R. Brad Jones ◽  
Aashish R. Jha ◽  
...  

Abstract Natural killer (NK) cells are innate lymphocytes that play an important role against viral infections and cancer. This effect is achieved through a complex mosaic of inhibitory and activating receptors expressed by NK cells that ultimately determine the magnitude of the NK-cell response. The T-cell immunoglobulin– and mucin domain–containing (Tim)–3 receptor was initially identified as a T-helper 1–specific type I membrane protein involved in regulating T-cell responses. Human NK cells transcribe the highest amounts of Tim-3 among lymphocytes. Tim-3 protein is expressed on essentially all mature CD56dimCD16+ NK cells and is expressed heterogeneously in the immature CD56brightCD16– NK-cell subset in blood from healthy adults and in cord blood. Tim-3 expression was induced on CD56brightCD16− NK cells after stimulation with IL-15 or IL-12 and IL-18 in vitro, suggesting that Tim-3 is a maturation marker on NK cells. Whereas Tim-3 has been used to identify dysfunctional T cells, NK cells expressing high amounts of Tim-3 are fully responsive with respect to cytokine production and cytotoxicity. However, when Tim-3 was cross-linked with antibodies it suppressed NK cell–mediated cytotoxicity. These findings suggest that NK-cell responses may be negatively regulated when NK cells encounter target cells expressing cognate ligands of Tim-3.


Blood ◽  
2009 ◽  
Vol 113 (14) ◽  
pp. 3218-3225 ◽  
Author(s):  
Neil C. Robson ◽  
Heng Wei ◽  
Tristan McAlpine ◽  
Naomi Kirkpatrick ◽  
Jonathan Cebon ◽  
...  

Abstract Dendritic-cell (DC) and natural killer (NK)–cell interactions are critical in sculpting the adaptive immune response. However, the mechanisms by which DCs down-regulate NK-cell functions are not well understood. NK-cell function is inhibited by transforming growth factor beta (TGF-β), but DCs do not appear to produce TGF-β. We have previously shown that activated human DCs produce large amounts of activin-A, a TGF-β superfamily member, which autoregulates DC function. The present report shows that NKcells express type I and II activin receptors and that activin-A triggers NK-cell Smad 2/3 signaling. Furthermore, activin-A directly regulates NK cell functions by (1) down-regulating the T-box transcription factor T-bet and interferon gamma (IFN-γ) but not perforin or granzyme mRNA; (2) suppressing NK-cell IFN-γ production as potently as TGF-β; and (3) suppressing NK-cell CD25 expression and proliferation and sculpting NK-cell cytokine and chemokine profiles. Interestingly, unlike TGF-β, activin-A weakly down-regulates the NK-cell natural cytotoxicity receptors (NCRs) NKp30 and NKG2D but does not attenuate their cytotoxic function. These findings provide the first evidence for a novel immune regulatory role of activin-A during DC-mediated NK-cell regulation, highlighting the potential of antagonizing activin-A signaling in vivo to enhance NK cell–mediated immune functions and adaptive immunity.


Blood ◽  
1984 ◽  
Vol 63 (2) ◽  
pp. 260-269 ◽  
Author(s):  
KF Mangan ◽  
ME Hartnett ◽  
SA Matis ◽  
A Winkelstein ◽  
T Abo

Abstract To determine the role of natural killer (NK) cells in the regulation of human erythropoiesis, we studied the effects of NK-enriched cell populations on the in vitro proliferation of erythroid stem cells at three different levels of maturation (day 14 blood BFU-E, day 5–6 marrow CFU-E, and day 10–12 marrow BFU-E). NK cells were enriched from blood by Percoll density gradient centrifugation and by fluorescence- activated cell sorting (FACS), using the human natural killer cell monoclonal antibody, HNK-1. The isolated enriched fractions were cocultured with autologous nonadherent marrow cells or blood null cells and erythropoietin in a methylcellulose erythroid culture system. Cells from low-density Percoll fractions (NK-enriched cells) were predominantly large granular lymphocytes with cytotoxic activity against K562 targets 6–10-fold greater than cells obtained from high- density Percoll fractions (NK-depleted cells). In coculture with marrow nonadherent cells (NA) at NK:NA ratios of 2:1, NK-enriched cells suppressed day 5–6 CFU-E to 62% (p less than 0.025) of controls, whereas NK-depleted cells slightly augmented CFU-E to 130% of controls (p greater than 0.05). In contrast, no suppression of day 10–12 marrow BFU-E was observed employing NK-enriched cells. The NK CFU-E suppressor effects were abolished by complement-mediated lysis of NK-enriched cells with the natural killer cell antibody, HNK-1. Highly purified HNK- 1+ cells separated by FACS suppressed marrow CFU-E to 34% (p less than 0.025) and marrow BFU-E to 41% (p less than 0.025) of controls. HNK- cells had no significant effect on either BFU-E or CFU-E growth. NK- enriched cells were poor stimulators of day 14 blood BFU-E in comparison to equal numbers of NK-depleted cells or T cells isolated by E-rosetting (p less than 0.01). Interferon boosting of NK-enriched cells abolished their suboptimal burst-promoting effects and augmented their CFU-E suppressor effects. These studies provide evidence for a potential regulatory role of NK cells in erythropoiesis. The NK suppressor effect is maximal at the level of the mature erythroid stem cell CFU-E. These findings may explain some hypoproliferative anemias that develop in certain NK cell-activated states.


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 ◽  
2009 ◽  
Vol 113 (11) ◽  
pp. 2470-2477 ◽  
Author(s):  
Il-Kyoo Park ◽  
Chiara Giovenzana ◽  
Tiffany L. Hughes ◽  
Jianhua Yu ◽  
Rossana Trotta ◽  
...  

Interleukin-15 (IL-15) is essential for natural killer (NK) cell differentiation. In this study, we assessed whether the receptor tyrosine kinase Axl and its ligand, Gas6, are involved in IL-15–mediated human NK differentiation from CD34+ hematopoietic progenitor cells (HPCs). Blocking the Axl-Gas6 interaction with a soluble Axl fusion protein (Axl-Fc) or the vitamin K inhibitor warfarin significantly diminished the absolute number and percentage of CD3−CD56+ NK cells derived from human CD34+ HPCs cultured in the presence of IL-15, probably resulting in part from reduced phosphorylation of STAT5. In addition, CD3−CD56+ NK cells derived from culture of CD34+ HPCs with IL-15 and Axl-Fc had a significantly diminished capacity to express interferon-γ or its master regulator, T-BET. Culture of CD34+ HPCs in the presence of c-Kit ligand and Axl-Fc resulted in a significant decrease in the frequency of NK precursor cells responding to IL-15, probably the result of reduced c-Kit phosphorylation. Collectively, our data suggest that the Axl/Gas6 pathway contributes to normal human NK-cell development, at least in part via its regulatory effects on both the IL-15 and c-Kit signaling pathways in CD34+ HPCs, and to functional NK-cell maturation via an effect on the master regulatory transcription factor T-BET.


2020 ◽  
Vol 21 (24) ◽  
pp. 9499
Author(s):  
Dong Oh Kim ◽  
Jae-Eun Byun ◽  
Won Sam Kim ◽  
Mi Jeong Kim ◽  
Jung Ha Choi ◽  
...  

The function of natural killer (NK) cell-derived interferon-γ (IFN-γ) expands to remove pathogens by increasing the ability of innate immune cells. Here, we identified the critical role of thioredoxin-interacting protein (TXNIP) in the production of IFN-γ in NK cells during bacterial infection. TXNIP inhibited the production of IFN-γ and the activation of transforming growth factor β-activated kinase 1 (TAK1) activity in primary mouse and human NK cells. TXNIP directly interacted with TAK1 and inhibited TAK1 activity by interfering with the complex formation between TAK1 and TAK1 binding protein 1 (TAB1). Txnip−/− (KO) NK cells enhanced the activation of macrophages by inducing IFN-γ production during Pam3CSK4 stimulation or Staphylococcus aureus (S. aureus) infection and contributed to expedite the bacterial clearance. Our findings suggest that NK cell-derived IFN-γ is critical for host defense and that TXNIP plays an important role as an inhibitor of NK cell-mediated macrophage activation by inhibiting the production of IFN-γ during bacterial infection.


1990 ◽  
Vol 272 (2) ◽  
pp. 327-331 ◽  
Author(s):  
M M Whalen ◽  
A D Bankhurst

Membranes from highly purified natural killer (NK) cells were ADP-ribosylated by treatment with cholera toxin (CTX). CTX resulted in a single band of specific 32P incorporation at Mr 43,600. CTX treatment of intact NK cells caused a 9-fold increase in cyclic AMP (cAMP) concentrations. Pretreatment of NK cells with CTX diminished their ability to lyse K562 tumour cells by up to 79%. Forskolin treatment elevated NK cell cAMP levels 8-fold and decreased lysis of K562 cells by up to 45%. Adrenaline and isoprenaline (isoproterenol) both inhibited lysis of K562 cells by approx. 35% and elevated cAMP by at least 2.5-fold, and their inhibition of lysis was reversed by propranolol. These data suggest that the stimulatory guanine-nucleotide-binding protein GS coupled to beta-adrenergic receptors is involved in transducing signals which inhibit NK cell lysis of tumour cells. CTX and forskolin also diminish the ability of NK cells to bind K562 cells (binding is necessary for lysis). This suggests that the NK-cell receptor(s) for the tumour cell may be altered as a consequence of cAMP-mediated events or by activation of GS.


2012 ◽  
Vol 209 (5) ◽  
pp. 947-954 ◽  
Author(s):  
Joseph C. Sun ◽  
Sharline Madera ◽  
Natalie A. Bezman ◽  
Joshua N. Beilke ◽  
Mark H. Kaplan ◽  
...  

Although natural killer (NK) cells are classified as innate immune cells, recent studies demonstrate that NK cells can become long-lived memory cells and contribute to secondary immune responses. The precise signals that promote generation of long-lived memory NK cells are unknown. Using cytokine receptor-deficient mice, we show that interleukin-12 (IL-12) is indispensible for mouse cytomegalovirus (MCMV)-specific NK cell expansion and generation of memory NK cells. In contrast to wild-type NK cells that proliferated robustly and resided in lymphoid and nonlymphoid tissues for months after MCMV infection, IL-12 receptor–deficient NK cells failed to expand and were unable to mediate protection after MCMV challenge. We further demonstrate that a STAT4-dependent IFN-γ–independent mechanism contributes toward the generation of memory NK cells during MCMV infection. Understanding the full contribution of inflammatory cytokine signaling to the NK cell response against viral infection will be of interest for the development of vaccines and therapeutics.


mBio ◽  
2011 ◽  
Vol 2 (4) ◽  
Author(s):  
Ethan A. Mack ◽  
Lara E. Kallal ◽  
Delia A. Demers ◽  
Christine A. Biron

ABSTRACTNatural killer (NK) cells are equipped to innately produce the cytokine gamma interferon (IFN-γ) in part because they basally express high levels of the signal transducer and activator of transcription 4 (STAT4). Type 1 interferons (IFNs) have the potential to activate STAT4 and promote IFN-γ expression, but concurrent induction of elevated STAT1 negatively regulates access to the pathway. As a consequence, it has been difficult to detect type 1 IFN stimulation of NK cell IFN-γ during viral infections in the presence of STAT1 and to understand the evolutionary advantage for maintaining the pathway. The studies reported here evaluated NK cell responses following infections with lymphocytic choriomeningitis virus (LCMV) in the compartment handling the earliest events after infection, the peritoneal cavity. The production of type 1 IFNs, both IFN-α and IFN-β, was shown to be early and of short duration, peaking at 30 h after challenge. NK cell IFN-γ expression was detected with overlapping kinetics and required activating signals delivered through type 1 IFN receptors and STAT4. It took place under conditions of high STAT4 levels but preceded elevated STAT1 expression in NK cells. The IFN-γ response reduced viral burdens. Interestingly, increases in STAT1 were delayed in NK cells compared to other peritoneal exudate cell (PEC) populations. Taken together, the studies demonstrate a novel mechanism for stimulating IFN-γ production and elucidate a biological role for type 1 IFN access to STAT4 in NK cells.IMPORTANCEPathways regulating the complex and sometimes paradoxical effects of cytokines are poorly understood. Accumulating evidence indicates that the biological consequences of type 1 interferon (IFN) exposure are shaped by modifying the concentrations of particular STATs to change access to the different signaling molecules. The results of the experiments presented conclusively demonstrate that NK cell IFN-γ can be induced through type 1 IFN and STAT4 at the first site of infection during a period with high STAT4 but prior to induction of elevated STAT1 in the cells. The response mediates a role in viral defense. Thus, a very early pathway to and source of IFN-γ in evolving immune responses to infections are identified by this work. The information obtained helps resolve long-standing controversies and advances the understanding of mechanisms regulating key type 1 IFN functions, in different cells and compartments and at different times of infection, for accessing biologically important functions.


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