Abstract 15301: Peripheral CD56 bright Natural Killer Cells Associate With Increased Atheroburden and Unstable Plaque Features in Humans

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Hema Kothari ◽  
Fabrizio Drago ◽  
Chantel McSkimming ◽  
Coleen A McNamara

Background: Atherosclerotic plaques in mice and humans contain natural killer (NK) cells. Data on the role of NK cells in atherosclerosis using different transgenic mice models is inconsistent. Some studies showed that NK cells augment atherosclerosis through their cytotoxic potential, while others reported no effect. Evidence in humans indicates that NK cells are atherogenic. Frequency of NK cells and expression of the activating NK cell receptors are associated with severe disease and symptomatic carotid atherosclerotic plaques in humans. Hypothesis: We tested if coronary artery disease (CAD) subjects with necrotic plaques have a higher frequency of the circulating NK cells. Methods: We performed mass cytometry on peripheral blood mononuclear cells from matched CAD subjects with low and high (n=9 each) necrotic plaque content as determined by intravascular ultrasound-virtual histology. Results: CAD subjects with high necrotic plaques have significantly higher atheroburden, stenosis, calcium, fatty plaque content, and lower plaque fibrosis. Interestingly, CAD subjects with high necrotic plaques exhibited a significantly higher frequency of the CD56 bright NK cells as compared to those with low necrotic plaques (4.618 ± 0.625 vs 2.481 ± 0.37; p=0.011). Moreover, frequency of CD25 + NK cells also trended to be higher in subjects with high necrotic plaques. The frequency of the cytotoxic CD56 dim NK cells did not differ between the two groups. Correlation analyses demonstrated a significant positive association of CD56 bright NK cells with atheroburden (r=0.43; p=0.04), stenosis (r=0.58; p=0.005), plaque necrotic (r=0.71; p=0.002), calcium contents (r=0.73; p=0.0001), and a negative association with the plaque fibrous content (r=0.71; p= 0.0003). CD25 + NK cells also showed similar trending associations with burden, stenosis and plaque features. Conclusions: Our data provides yet another evidence of the atherogenic role of NK cells in humans and indicates that the CD56 bright NK cells may contribute to the development of a vulnerable plaque. CD56 bright NK cells produce proinflammatory cytokines including IFN-γ and TNF-α and cytotoxic enzymes that may contribute to increased inflammation, cell activation, and apoptosis within the plaque.

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.


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.


2008 ◽  
Vol 76 (11) ◽  
pp. 5100-5109 ◽  
Author(s):  
Mayra X. Hernandez Sanabria ◽  
Diego A. Vargas-Inchaustegui ◽  
Lijun Xin ◽  
Lynn Soong

ABSTRACT The importance of the interaction between natural killer (NK) cells and dendritic cells (DCs) in the expansion of antiviral and antitumor immune responses is well-documented; however, limited information on DC-NK cell interaction during parasitic infections is available. Given that some Leishmania parasites are known to prevent or suppress DC activation, we developed a DC-NK cell coculture system to examine the role of NK cells in modulating the functions of Leishmania-infected DCs. We found that the addition of freshly isolated, resting NK cells significantly promoted the activation of DCs that were preinfected with Leishmania amazonensis promastigotes and that these activated DCs, in turn, stimulated NK cell activation mostly via cell contact-dependent mechanisms. Notably, L. amazonensis amastigote infection failed to activate DCs, and this lack of DC activation could be partially reversed by the addition of preactivated NK (ANK) cells but not resting NK cells. Moreover, the adoptive transfer of ANK cells into L. amazonensis-infected mice markedly increased DC and T-cell activation and reduced tissue parasite loads at 1 and 3 weeks postinfection. These results suggest differential roles of DC-NK cell cross talk at different stages of Leishmania infection and provide new insight into the interplay of components of the innate immune system during parasitic infection.


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.


Author(s):  
Christopher Maucourant ◽  
Iva Filipovic ◽  
Andrea Ponzetta ◽  
Soo Aleman ◽  
Martin Cornillet ◽  
...  

Understanding innate immune responses in COVID-19 is important for deciphering mechanisms of host responses and interpreting disease pathogenesis. Natural killer (NK) cells are innate effector lymphocytes that respond to acute viral infections, but might also contribute to immune pathology. Here, using 28-color flow cytometry, we describe a state of strong NK cell activation across distinct subsets in peripheral blood of COVID-19 patients, a pattern mirrored in scRNA-seq signatures of lung NK cells. Unsupervised high-dimensional analysis identified distinct immunophenotypes that were linked to disease severity. Hallmarks of these immunophenotypes were high expression of perforin, NKG2C, and Ksp37, reflecting a high presence of adaptive NK cell expansions in circulation of patients with severe disease. Finally, arming of CD56bright NK cells was observed in course of COVID-19 disease states, driven by a defined protein-protein interaction network of inflammatory soluble factors. This provides a detailed map of the NK cell activation-landscape in COVID-19 disease.


2020 ◽  
Vol 5 (50) ◽  
pp. eabd6832 ◽  
Author(s):  
Christopher Maucourant ◽  
Iva Filipovic ◽  
Andrea Ponzetta ◽  
Soo Aleman ◽  
Martin Cornillet ◽  
...  

Understanding innate immune responses in COVID-19 is important to decipher mechanisms of host responses and interpret disease pathogenesis. Natural killer (NK) cells are innate effector lymphocytes that respond to acute viral infections but might also contribute to immunopathology. Using 28-color flow cytometry, we here reveal strong NK cell activation across distinct subsets in peripheral blood of COVID-19 patients. This pattern was mirrored in scRNA-seq signatures of NK cells in bronchoalveolar lavage from COVID-19 patients. Unsupervised high-dimensional analysis of peripheral blood NK cells furthermore identified distinct NK cell immunotypes that were linked to disease severity. Hallmarks of these immunotypes were high expression of perforin, NKG2C, and Ksp37, reflecting increased presence of adaptive NK cells in circulation of patients with severe disease. Finally, arming of CD56bright NK cells was observed across COVID-19 disease states, driven by a defined protein-protein interaction network of inflammatory soluble factors. This study provides a detailed map of the NK cell activation landscape in COVID-19 disease.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Keishiro Amano ◽  
Masahiro Hirayama ◽  
Eiichi Azuma ◽  
Shotaro Iwamoto ◽  
Yoshitaka Keida ◽  
...  

Natural killer (NK) cells acquire effector function through a licensing process and exert anti-leukemia/tumor effect. However, there is no means to promote a licensing effect of allogeneic NK cells other than cytomegalovirus reactivation-induced licensing in allogeneic hematopoietic stem cell transplantation in human. In mice, a licensing process is mediated by Ly49 receptors which recognize self-major histocompatibility complex class I. The distribution of four Ly49 receptors showed similar pattern in congenic mice, B10, B10.BR, and B10.D2, which have B10 background. Forty Gy-irradiated2×106B10.D2 cells including splenocytes, peripheral blood mononuclear cells in untreated mice, or granulocyte colony-stimulating factor treated mice were injected intraperitoneally into B10 mice. We found that murine NK cells were effectively licensed by intraperitoneal injection of donor neutrophils with its corresponding NK receptor ligand in B10 mice as a recipient and B10.D2 as a donor. Mechanistic studies revealed that NK cells showed the upregulation of intracellular interferon-γand CD107a expression as markers of NK cell activation. Moreover, enriched neutrophils enhanced licensing effect of NK cells; meanwhile, licensing effect was diminished by depletion of neutrophils. Collectively, injection of neutrophils induced NK cell licensing (activation) via NK receptor ligand interaction.


1998 ◽  
Vol 66 (6) ◽  
pp. 2698-2704 ◽  
Author(s):  
Kerima Maasho ◽  
Fabio Sanchez ◽  
Erwin Schurr ◽  
Asrat Hailu ◽  
Hannah Akuffo

ABSTRACT The role of natural versus acquired immunity to Leishmania aethiopica infection in humans is the focus of our studies. We found in previous studies that mononuclear cells from nonexposed healthy Swedish donors responded to Leishmania antigen stimulation by proliferation and gamma interferon production. The main cell type responding was CD3− CD16/56+ natural killer (NK) cells. These findings led us to suggest that the potential to produce a rapid, nonacquired NK cell response may be a protective phenotype. In order to test this hypothesis, an area in Ethiopia whereLeishmania is endemic was selected, and peripheral blood mononuclear cells were obtained from individuals who had lived in the area most of their lives but had no evidence of past or present leishmaniasis. Their responses were compared with those of confirmed leishmaniasis patients from the same region with active lesions or cured leishmaniasis lesions. Cells from these donors were stimulated in vitro with L. aethiopica antigen. Responses were measured by proliferation, cytokine production, and phenotype analysis by fluorescence-activated cell sorting. The association ofNRAMP1 alleles with the studied phenotype and susceptibility to L. aethiopica-induced leishmaniasis was also evaluated. The results show that Leishmania antigens can induce NK cell and CD8+-T-cell responses in vitro. This is clearly seen in proliferating cells from the cured (immune) individuals and the apparently protected controls from the area of endemicity. It contrasted with the reactivity of the patients, where some NK proliferation was coupled with enhanced CD4+-T-cell proliferation. We conclude from these observations that NK cells and CD8+ cells proliferating in response toLeishmania stimulation are involved in protection from and healing of (Ethiopian) cutaneous leishmaniasis; however, such mechanisms appear to be unrelated to the NRAMP1 host resistance gene.


Blood ◽  
2005 ◽  
Vol 106 (1) ◽  
pp. 376-383 ◽  
Author(s):  
Chihaya Imai ◽  
Shotaro Iwamoto ◽  
Dario Campana

Natural killer (NK) cells hold promise for improving the therapeutic potential of allogeneic hematopoietic transplantation, but their effectiveness is limited by inhibitory HLA types. We sought to overcome this intrinsic resistance by transducing CD56+CD3- NK cells with chimeric receptors directed against CD19, a molecule widely expressed by malignant B cells. An abundance of NK cells for transduction was secured by culturing peripheral blood mononuclear cells with K562 cells expressing the NK-stimulatory molecules 4-1BB ligand and interleukin 15, which yielded a median greater than 1000-fold expansion of CD56+CD3- cells at 3 weeks of culture, without T-lymphocyte expansion. Expression of anti-CD19 receptors linked to CD3ζ overcame NK resistance and markedly enhanced NK-cell-mediated killing of leukemic cells. This result was significantly improved by adding the 4-1BB costimulatory molecule to the chimeric anti-CD19-CD3ζ receptor; the cytotoxicity produced by NK cells expressing this construct uniformly exceeded that of NK cells whose signaling receptors lacked 4-1BB, even when natural cytotoxicity was apparent. Addition of 4-1BB was also associated with increased cell activation and production of interferon γ and granulocyte-macrophage colony-stimulating factor. Our findings indicate that enforced expression of signaling receptors by NK cells might circumvent inhibitory signals, providing a novel means to enhance the effectiveness of allogeneic stem cell transplantation.


2021 ◽  
Vol 22 (2) ◽  
pp. 656
Author(s):  
Hantae Jo ◽  
Byungsun Cha ◽  
Haneul Kim ◽  
Sofia Brito ◽  
Byeong Mun Kwak ◽  
...  

Natural killer (NK) cells are lymphocytes that can directly destroy cancer cells. When NK cells are activated, CD56 and CD107a markers are able to recognize cancer cells and release perforin and granzyme B proteins that induce apoptosis in the targeted cells. In this study, we focused on the role of phytoncides in activating NK cells and promoting anticancer effects. We tested the effects of several phytoncide compounds on NK-92mi cells and demonstrated that α-pinene treatment exhibited higher anticancer effects, as observed by the increased levels of perforin, granzyme B, CD56 and CD107a. Furthermore, α-pinene treatment in NK-92mi cells increased NK cell cytotoxicity in two different cell lines, and immunoblot assays revealed that the ERK/AKT pathway is involved in NK cell cytotoxicity in response to phytoncides. Furthermore, CT-26 colon cancer cells were allografted subcutaneously into BALB/c mice, and α-pinene treatment then inhibited allografted tumor growth. Our findings demonstrate that α-pinene activates NK cells and increases NK cell cytotoxicity, suggesting it is a potential compound for cancer immunotherapy.


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