scholarly journals The Effect of Antiretroviral Naïve HIV-1 Infection on the Ability of Natural Killer Cells to Produce IFN-γ upon Exposure to Plasmodium falciparum-Infected Erythrocytes

2017 ◽  
Vol 2 (1) ◽  
pp. 1-13
Author(s):  
Carole Stéphanie Sake ◽  
Loveline Ngu ◽  
Georgia Ambada ◽  
Jean Paul Chedjou ◽  
Nadesh Nji ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Nk Cells ◽  
Natural Killer ◽  
Nk Cell ◽  
Plasmodium Species ◽  
Sub Saharan Africa ◽  
Cell Mediated Immunity ◽  
Infected People ◽  
Ifn Γ ◽  
Hiv 1

Background: In sub-Saharan Africa, intense perennial Plasmodium species transmission coincides with areas of high prevalence of the human immunodeficiency virus type 1 (HIV) infection. This implies that antiretroviral naïve HIV-infected people living within these regions are repeatedly exposed to Plasmodium species infection and consequently malaria. Natural killer (NK) cells are known to contribute to malaria immunity through the production of IFN-γ after exposure to Plasmodium falciparum-infected erythrocytes (infected red blood cells [iRBC]). However, in antiretroviral naïve HIV-1 infection, these functions could be impaired. In this study we assess the ability of NK cells from antiretroviral naïve HIV-1-infected people to respond to iRBC. Method: Magnetically sorted NK cells from antiretroviral naïve HIV-1-infected people were tested for their ability to respond to iRBC following in vitro coculture. NK cell IFN-γ production after coculture was measured through multiparametric flow cytometry analysis. Results: Our data show a significant reduction (p = 0.03) in IFN-γ production by NK cells from antiretroviral naïve HIV-1-infected people after coculture with iRBCs. This was in contrast to the NK cell response from healthy controls, which demonstrated elevated IFN-γ production. NK cell IFN-γ production from untreated HIV-1-infected participants correlated inversely with the viral load (r = -0.5, p = 0.02) and positively with total helper CD4+ T-cell count (r = 0.4, p = 0.04). Thus, antiretroviral naïve HIV-1 infection can dampen NK cell-mediated immunity to P. falciparum infection in malaria-intense regions. This could in effect escalate morbidity and mortality in people chronically infected with HIV-1.

scholarly journals Natural Killer Cell Function Is Well Preserved in Asymptomatic Human Immunodeficiency Virus Type 2 (HIV-2) Infection but Similar to That of HIV-1 Infection When CD4 T-Cell Counts Fall

2006 ◽  
Vol 80 (5) ◽  
pp. 2529-2538 ◽  
Author(s):  
Samuel Victor Nuvor ◽  
Marianne van der Sande ◽  
Sarah Rowland-Jones ◽  
Hilton Whittle ◽  
Assan Jaye
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Nk Cells ◽  
Natural Killer ◽  
Human Immunodeficiency Virus Type ◽  
Nk Cell ◽  
Cell Counts ◽  
Immunodeficiency Virus ◽  
Ifn Γ ◽  
Hiv 1

ABSTRACT Natural killer (NK) cells are potent effectors of natural immunity and their activity prevents human immunodeficiency virus type 1 (HIV-1) viral entry and viral replication. We sought to determine whether NK immune responses are associated with different clinical course of HIV-1 and HIV-2 infections. A cross-sectional analysis of NK cell responses was undertaken in 30 HIV-1 and 30 HIV-2 subjects in each of three categories of CD4+-T-cell counts (>500, 200 to 500, and <200 cells/μl) and in 50 HIV-uninfected control subjects. Lytic activity and gamma interferon (IFN-γ) secretion were measured by chromium release and enzyme-linked immunospot assays, respectively. Flow cytometry was used to assess intracellular cytokines and chemokines. Levels of NK cytotoxicity were significantly higher in HIV-2 than in HIV-1 infections in subjects with high CD4+-T-cell counts and were similar to that of the healthy controls. In these HIV-2 subjects, cytolytic activity was positively correlated to NK cell count and inversely related to plasma viremia. Levels of intracellular MIP-1β, RANTES, tumor necrosis factor alpha, and IFN-γ produced by NK CD56bright cells were significantly higher in HIV-2- than HIV-1-infected subjects with high CD4+-T-cell counts but fell to similar levels as CD4 counts dropped. The data suggest efficient cytolytic and chemokine-suppressive activity of NK cells early in HIV-2 infection, which is associated with high CD4+ T-cell counts. Enhancement of these functions may be important in immune-based therapy to control HIV disease.

scholarly journals HIV-1-induced cytokines deplete homeostatic ILCs and expand TCF7-dependent memory NK cells: Supplemental Figures and Tables

2017 ◽  
Author(s):  
Yetao Wang ◽  
Kyle Gellatly ◽  
Sean McCauley ◽  
Pranitha Vangala ◽  
Kyusik Kim ◽  
...  
Keyword(s):  
Nk Cells ◽  
Inflammatory Cytokines ◽  
Nk Cell ◽  
Ex Vivo ◽  
Developmental Trajectory ◽  
Lymphoid Cells ◽  
Infected People ◽  
Cell Induction ◽  
Hiv 1 ◽  
Memory Nk Cells

HIV-1-infected people who take medications that suppress viremia, preserve CD4+ T cells, and prevent AIDS, have chronic inflammation with increased cardiovascular mortality. To investigate the etiology of this inflammation, the effect of HIV-1 on innate lymphoid cells (ILCs) and NK cells was examined. Homeostatic ILCs in blood and intestine were depleted permanently. NK cells were skewed towards a memory subset. Cytokines that are elevated during HIV-1 infection reproduced both abnormalities ex vivo. Pseudotime analysis of single NK cell transcriptomes revealed a developmental trajectory towards a subset with expression profile, chromatin state, and biological function like memory T lymphocytes. Expression of TCF7, a WNT transcription factor, increased over the course of the trajectory. TCF7 disruption, or WNT inhibition, prevented memory NK cell induction by inflammatory cytokines. These results demonstrate that inflammatory cytokines associated with HIV-1 infection irreversibly disrupt homeostatic ILCs and cause developmental shift towards TCF7+ memory NK cells.

scholarly journals Human NK cells prime inflammatory DC precursors to induce Tc17 differentiation

2020 ◽  
Vol 4 (16) ◽  
pp. 3990-4006
Author(s):  
Maria A. Clavijo-Salomon ◽  
Rosalba Salcedo ◽  
Soumen Roy ◽  
Rodrigo X. das Neves ◽  
Amiran Dzutsev ◽  
...  
Keyword(s):  
Nk Cells ◽  
Nk Cell ◽  
Interferon Γ ◽  
T Cell Subsets ◽  
Cell Mediated Immunity ◽  
Limited Information ◽  
Interleukin 17A ◽  
Healthy Donors ◽  
Ifn Γ ◽  
Inflammatory Dendritic Cells

Abstract Adaptive immune responses are acknowledged to evolve from innate immunity. However, limited information exists regarding whether encounters between innate cells direct the generation of specialized T-cell subsets. We aim to understand how natural killer (NK) cells modulate cell-mediated immunity in humans. We found that human CD14+CD16− monocytes that differentiate into inflammatory dendritic cells (DCs) are shaped at the early stages of differentiation by cell-to-cell interactions with NK cells. Although a fraction of monocytes is eliminated by NK-cell–mediated cytotoxicity, the polarization of interferon-γ (IFN-γ) at the NKp30-stabilized synapses triggers a stable IFN-γ signature in surviving monocytes that persists after their differentiation into DCs. Notably, NK-cell–instructed DCs drive the priming of type 17 CD8+ T cells (Tc17) with the capacity to produce IFN-γ and interleukin-17A. Compared with healthy donors, this cellular network is impaired in patients with classical NK-cell deficiency driven by mutations in the GATA2 gene. Our findings reveal a previously unrecognized connection by which Tc17-mediated immunity might be regulated by NK-cell–mediated tuning of antigen-presenting cells.

scholarly journals Aberrant anti-viral response of natural killer cells in severe asthma

2020 ◽  
Vol 55 (5) ◽  
pp. 1802422
Author(s):  
Justine Devulder ◽  
Cécile Chenivesse ◽  
Valérie Ledroit ◽  
Stéphanie Fry ◽  
Pierre-Emmanuel Lobert ◽  
...  
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Severe Asthma ◽  
Cell Activation ◽  
Mononuclear Cells ◽  
Nk Cell ◽  
Peripheral Blood Mononuclear ◽  
Healthy Donors ◽  
Asthma Patients ◽  
Ifn Γ

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.

scholarly journals Rapid development of exhaustion and down-regulation of eomesodermin limit the antitumor activity of adoptively transferred murine natural killer cells

Blood ◽  
2012 ◽  
Vol 119 (24) ◽  
pp. 5758-5768 ◽  
Author(s):  
Saar Gill ◽  
Adrianne E. Vasey ◽  
Alysha De Souza ◽  
Jeanette Baker ◽  
Aaron T. Smith ◽  
...  
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Nk Cell ◽  
Rapid Development ◽  
Receptor Expression ◽  
Down Regulation ◽  
First Response ◽  
Control Tumor Growth ◽  
Control Tumor ◽  
Ifn Γ

Abstract Natural killer (NK) cells are potent anti-viral and antitumor “first responders” endowed with natural cytotoxicity and cytokine production capabilities. To date, attempts to translate these promising biologic functions through the adoptive transfer of NK cells for the treatment of cancer have been of limited benefit. Here we trace the fate of adoptively transferred murine NK cells and make the surprising observation that NK cells traffic to tumor sites yet fail to control tumor growth or improve survival. This dysfunction is related to a rapid down-regulation of activating receptor expression and loss of important effector functions. Loss of interferon (IFN)γ production occurs early after transfer, whereas loss of cytotoxicity progresses with homeostatic proliferation and tumor exposure. The dysfunctional phenotype is accompanied by down-regulation of the transcription factors Eomesodermin and T-bet, and can be partially reversed by the forced overexpression of Eomesodermin. These results provide the first demonstration of NK-cell exhaustion and suggest that the NK-cell first-response capability is intrinsically limited. Further, novel approaches may be required to circumvent the described dysfunctional phenotype.

scholarly journals Slaying the Trojan Horse: Natural Killer Cells Exhibit Robust Anti-HIV-1 Antibody-Dependent Activation and Cytolysis against Allogeneic T Cells

2014 ◽  
Vol 89 (1) ◽  
pp. 97-109 ◽  
Author(s):  
Shayarana L. Gooneratne ◽  
Jonathan Richard ◽  
Wen Shi Lee ◽  
Andrés Finzi ◽  
Stephen J. Kent ◽  
...  
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Natural Killer ◽  
Nk Cell ◽  
Target Cells ◽  
Dependent Manner ◽  
Inhibitory Receptors ◽  
Cell Responses ◽  
Anti Hiv ◽  
Hiv 1

ABSTRACTMany attempts to design prophylactic human immunodeficiency virus type 1 (HIV-1) vaccines have focused on the induction of neutralizing antibodies (Abs) that block infection by free virions. Despite the focus on viral particles, virus-infected cells, which can be found within mucosal secretions, are more infectious than free virus bothin vitroandin vivo. Furthermore, assessment of human transmission couples suggests infected seminal lymphocytes might be responsible for a proportion of HIV-1 transmissions. Although vaccines that induce neutralizing Abs are sought, only some broadly neutralizing Abs efficiently block cell-to-cell transmission of HIV-1. As HIV-1 vaccines need to elicit immune responses capable of controlling both free and cell-associated virus, we evaluated the potential of natural killer (NK) cells to respond in an Ab-dependent manner to allogeneic T cells bearing HIV-1 antigens. This study presents data measuring Ab-dependent anti-HIV-1 NK cell responses to primary and transformed allogeneic T-cell targets. We found that NK cells are robustly activated in an anti-HIV-1 Ab-dependent manner against allogeneic targets and that tested target cells are subject to Ab-dependent cytolysis. Furthermore, the educated KIR3DL1+NK cell subset from HLA-Bw4+individuals exhibits an activation advantage over the KIR3DL1−subset that contains both NK cells educated through other receptor/ligand combinations and uneducated NK cells. These results are intriguing and important for understanding the regulation of Ab-dependent NK cell responses and are potentially valuable for designing Ab-dependent therapies and/or vaccines.IMPORTANCENK cell-mediated anti-HIV-1 antibody-dependent functions have been associated with protection from infection and disease progression; however, their role in protecting from infection with allogeneic cells infected with HIV-1 is unknown. We found that HIV-1-specific ADCC antibodies bound to allogeneic cells infected with HIV-1 or coated with HIV-1 gp120 were capable of activating NK cells and/or trigging cytolysis of the allogeneic target cells. This suggests ADCC may be able to assist in preventing infection with cell-associated HIV-1. In order to fully utilize NK cell-mediated Ab-dependent effector functions, it might also be important that educated NK cells, which hold the highest activation potential, can become activated against targets bearing HIV-1 antigens and expressing the ligands for self-inhibitory receptors. Here, we show that with Ab-dependent stimulation, NK cells expressing inhibitory receptors can mediate robust activation against targets expressing the ligands for those receptors.

scholarly journals HIV-1-Specific T Cell-Dependent Natural Killer (NK) Cell Activation: Major Contribution by NK Cells to Interferon-γ Production in Response to HIV-1 Antigens

2009 ◽  
Vol 25 (6) ◽  
pp. 603-605 ◽  
Author(s):  
Christopher P. Loo ◽  
Brian R. Long ◽  
Frederick M. Hecht ◽  
Douglas F. Nixon ◽  
Jakob Michaëlsson
Keyword(s):  
T Cell ◽  
Nk Cells ◽  
Natural Killer ◽  
Cell Activation ◽  
Nk Cell ◽  
Interferon Γ ◽  
Hiv 1

scholarly journals TIM-3 Expression Is Downregulated on Human NK Cells in Response to Cancer Targets in Synergy with Activation

Cancers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2417 ◽  
Author(s):  
Tram N. Dao ◽  
Sagar Utturkar ◽  
Nadia Atallah Lanman ◽  
Sandro Matosevic
Keyword(s):  
T Cell ◽  
Nk Cells ◽  
Natural Killer ◽  
Interferon Gamma ◽  
Nk Cell ◽  
Ex Vivo ◽  
Cell Dysfunction ◽  
Nk Cell Receptors ◽  
Ifn Γ

Among natural killer (NK) cell receptors, the T-cell immunoglobulin and mucin-containing domain (TIM-3) has been associated with both inhibitory and activating functions, depending on context and activation pathway. Ex vivo and in vitro, expression of TIM-3 is inducible and depends on activation stimulus. Here, we report that TIM-3 expression can be downregulated on NK cells under specific conditions. When NK cells are exposed to cancer targets, they synergize with stimulation conditions to induce a substantial decrease in TIM-3 expression on their surface. We found that such downregulation occurs following prior NK activation. Downregulated TIM-3 expression correlated to lower cytotoxicity and lower interferon gamma (IFN-γ) expression, fueling the notion that TIM-3 might function as a benchmark for human NK cell dysfunction.

scholarly journals Interleukin-18 (IL-18) Enhances Innate IL-12-Mediated Resistance to Toxoplasma gondii

2000 ◽  
Vol 68 (12) ◽  
pp. 6932-6938 ◽  
Author(s):  
Guifang Cai ◽  
Robert Kastelein ◽  
Christopher A. Hunter
Keyword(s):  
Toxoplasma Gondii ◽  
Nk Cells ◽  
Nk Cell ◽  
Parasite Burden ◽  
Scid Mice ◽  
Interleukin 12 ◽  
Cell Mediated Immunity ◽  
Protective Effects ◽  
Innate Resistance ◽  
Ifn Γ

ABSTRACT Innate resistance to Toxoplasma gondii is dependent on the ability of interleukin-12 (IL-12) to stimulate natural killer (NK) cell production of gamma interferon (IFN-γ). Since IL-18 is a potent enhancer of IL-12-induced production of IFN-γ by NK cells, SCID mice (which lack an adaptive immune response) were used to assess the role of IL-18 in innate resistance to T. gondii. Administration of anti-IL-18 to SCID mice infected with T. gondii resulted in an early reduction in serum levels of IFN-γ but did not significantly decrease resistance to this infection. In contrast, administration of exogenous IL-18 to infected SCID mice resulted in increased production of IFN-γ, reduced parasite burden, and a delay in time to death. The protective effects of IL-18 treatment correlated with increased NK cell numbers and cytotoxic activity at the local site of administration and with elevated levels of inducible nitrous oxide synthose in the spleens of treated mice. In addition, in vivo depletion studies demonstrated that the ability of exogenous IL-18 to enhance resistance to T. gondii was dependent on IL-12, IFN-γ, and NK cells. Together, these studies demonstrate that although endogenous IL-18 appears to have a limited role in innate resistance to T. gondii, treatment with IL-18 can augment NK cell-mediated immunity to this pathogen.

Sign in / Sign up

Export Citation Format

Share Document