scholarly journals Activation of natural killer T cells enhances the function of regulatory T-cell therapy in suppressing murine GVHD

2021 ◽  
Vol 5 (11) ◽  
pp. 2528-2538
Author(s):  
Toshihito Hirai ◽  
Po-Yu Lin ◽  
Federico Simonetta ◽  
Kristina Maas-Bauer ◽  
Mustafa Turkoz ◽  
...  
Keyword(s):  
T Cells ◽  
Natural Killer ◽  
Adoptive Transfer ◽  
Cell Activation ◽  
Cellular Therapy ◽  
Inkt Cell ◽  
Inkt Cells ◽  
Adoptive Therapy ◽  
T Cell Therapy ◽  
Natural Killer T

Cellular therapy with regulatory T cells (Tregs) has shown promising results for suppressing graft-versus-host disease (GVHD) while preserving graft vs tumor effects in animal models and phase 1/2 clinical trials. However, a paucity of Tregs in the peripheral blood makes it difficult to acquire sufficient numbers of cells and hampers further clinical application. Invariant natural killer T (iNKT) cells constitute another compartment of regulatory cells that ameliorate GVHD through activation of Tregs after their own activation with α-galactosylceramide (α-GalCer) or adoptive transfer. We demonstrate here that a single administration of α-GalCer liposome (α-GalCer-lipo) enhanced the in vivo expansion of Tregs after adoptive transfer in a murine GVHD model and improved therapeutic efficacy of Treg therapy even after injection of otherwise suboptimal cell numbers. Host iNKT cells rather than donor iNKT cells were required for GVHD suppression because the survival benefit of α-GalCer-lipo administration was not shown in the transplantation of cells from wild-type (WT) C57BL/6 mice into Jα18−/− iNKT cell–deficient BALB/c mice, whereas it was observed from Jα18−/− C57BL/6 donor mice into WT BALB/c recipient mice. The combination of iNKT cell activation and Treg adoptive therapy may make Treg therapy more feasible and safer by enhancing the efficacy and reducing the number of Tregs required.

scholarly journals Innate and cytokine-driven signals, rather than microbial antigens, dominate in natural killer T cell activation during microbial infection

2011 ◽  
Vol 208 (6) ◽  
pp. 1163-1177 ◽  
Author(s):  
Manfred Brigl ◽  
Raju V.V. Tatituri ◽  
Gerald F.M. Watts ◽  
Veemal Bhowruth ◽  
Elizabeth A. Leadbetter ◽  
...  
Keyword(s):  
T Cells ◽  
Natural Killer ◽  
T Cell Activation ◽  
Cell Activation ◽  
Constitutive Expression ◽  
Microbial Pathogens ◽  
Inkt Cell ◽  
Microbial Infection ◽  
Inkt Cells ◽  
Natural Killer T

Invariant natural killer T cells (iNKT cells) are critical for host defense against a variety of microbial pathogens. However, the central question of how iNKT cells are activated by microbes has not been fully explained. The example of adaptive MHC-restricted T cells, studies using synthetic pharmacological α-galactosylceramides, and the recent discovery of microbial iNKT cell ligands have all suggested that recognition of foreign lipid antigens is the main driver for iNKT cell activation during infection. However, when we compared the role of microbial antigens versus innate cytokine-driven mechanisms, we found that iNKT cell interferon-γ production after in vitro stimulation or infection with diverse bacteria overwhelmingly depended on toll-like receptor–driven IL-12. Importantly, activation of iNKT cells in vivo during infection with Sphingomonas yanoikuyae or Streptococcus pneumoniae, pathogens which are known to express iNKT cell antigens and which require iNKT cells for effective protection, also predominantly depended on IL-12. Constitutive expression of high levels of IL-12 receptor by iNKT cells enabled instant IL-12–induced STAT4 activation, demonstrating that among T cells, iNKT cells are uniquely equipped for immediate, cytokine-driven activation. These findings reveal that innate and cytokine-driven signals, rather than cognate microbial antigen, dominate in iNKT cell activation during microbial infections.

scholarly journals Longitudinal analysis of invariant natural killer T cell activation reveals a cMAF-associated transcriptional state of NKT10 cells

2021 ◽  
Author(s):  
Lydia Lynch ◽  
Harry Kane ◽  
Nelson M LaMarche ◽  
Áine Ní Scannail ◽  
Michael P. Brenner
Keyword(s):  
T Cells ◽  
Natural Killer ◽  
T Cell Activation ◽  
Cell Activation ◽  
Inkt Cell ◽  
Inkt Cells ◽  
Innate T Cells ◽  
Nonpeptide Antigens ◽  
Invariant Natural Killer ◽  
Natural Killer T

Innate T cells, including CD1d-restricted invariant natural killer T (iNKT) cells, are characterized by their rapid activation in response to nonpeptide antigens, such as lipids. While the transcriptional profiles of naive, effector and memory adaptive T cells have been well studied, less is known about transcriptional regulation of different iNKT cell activation states. Here, using single cell RNA-sequencing, we performed longitudinal profiling of activated iNKT cells, generating a transcriptomic atlas of iNKT cell activation states. We found that transcriptional signatures of activation are highly conserved among heterogeneous iNKT cell populations, including NKT1, NKT2 and NKT17 subsets, and human iNKT cells. Strikingly, we found that regulatory iNKT cells, such as adipose iNKT cells, undergo blunted activation, and display constitutive enrichment of memory-like cMAF+ and KLRG1+ populations. Moreover, we identify a conserved cMAF-associated transcriptional network among NKT10 cells, providing novel insights into the biology of regulatory and antigen experienced iNKT cells.

Abstract 541: Specific Deletion of LDL Receptor--Related Protein on Macrophages Skews Cytokine Production by Invariant Natural Killer T Cells

2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Roman Covarrubias ◽  
Amy S Major
Keyword(s):  
Natural Killer ◽  
Cell Activation ◽  
Ldl Receptor ◽  
Inkt Cell ◽  
Related Protein ◽  
Inkt Cells ◽  
Glycolipid Antigen ◽  
Invariant Natural Killer ◽  
Natural Killer T

Invariant Natural Killer T (iNKT) cells are specialized lymphocytes that when activated can regulate chronic inflammatory conditions and atherosclerotic processes. The activation of iNKT cells occurs when glycolipid antigens bind the MHC class-I like molecule CD1d present on antigen presenting cells (APCs). The pathways by which glycolipid antigens target CD1d for presentation and activation of iNKT cells remain unclear, yet the expression of surface receptors associated with lipid homeostasis, such as the LDL receptor (LDLr), have been implicated in the modulation of iNKT cell activation. The LDLr has been shown to modulate this process by binding apoE-containing lipoproteins, which can carry antigenic glycolipids for iNKT cell activation. The LDL receptor-related protein (LRP), a transmembrane receptor from the LDL receptor family of proteins, shares structural homology with LDLr and can bind a number of ligands including apoE-containing lipoproteins. We hypothesized that LRP can play an active role in glycolipid antigen presentation and subsequent activation of iNKT cells. Here, we demonstrate that LRP is preferentially expressed at high levels on F4/80 + macrophages, when compared to other APCs. We also show that a specialized subset of macrophages expressing CD169, known for their ability to present glycolipid antigen to iNKT cells, have increased levels of LRP when compared to CD169 - macrophages. Using mice with a targeted deletion of LRP in macrophages, we observed decreased activation of iNKT cells in vitro (24, 48 hours) and normal IFN-gamma but blunted IL-4 response in vivo. Further flow cytometric analysis showed normal surface expression of CD1d in LRP-cKO macrophages as well as normal uptake of fluorescently labeled glycolipid in vitro . Additionally, analysis of the iNKT cell compartment in LRP-cKO mice revealed intact numbers and percentages of iNKT cells and no homeostatic disruption as evidenced by absence of programmed death-1 and LY-49. Collectively, these data suggest that macrophage LRP contributes to early iNKT cell activation by enhancing early IL-4 responses.

scholarly journals Human invariant natural killer T cells promote tolerance by preferential apoptosis induction of conventional dendritic cells

Haematologica ◽  
2021 ◽  
Author(s):  
Hannes Schmid ◽  
Emmanuelle M. Ribeiro ◽  
Kathy-Ann Secker ◽  
Silke Duerr-Stoerzer ◽  
Hildegard Keppeler ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Natural Killer ◽  
T Cell Activation ◽  
Cell Activation ◽  
Inkt Cells ◽  
Healthy Donors ◽  
Invariant Natural Killer ◽  
Natural Killer T

Graft-versus-host disease (GvHD) is a major cause of morbidity and mortality after allogeneic hematopoietic cell transplantation. We recently showed in murine studies and in vitro human models that adoptively transferred invariant natural killer T (iNKT) cells protect from GvHD and promote graft-versus-leukemia effects. The cellular mechanisms underlying GvHD prevention by iNKT cells in humans, however, remain unknown. To study relevant cellular interactions, dendritic cells (DCs) were either generated from monocytes or isolated directly from blood of healthy donors or GvHD patients and co-cultured in a mixed lymphocyte reaction (MLR) with T cells obtained from healthy donors or transplantation bags. Addition of culture-expanded iNKT cells to the MLR induced DC apoptosis in a cell contact-dependent manner, thereby preventing T-cell activation and proliferation. Annexin V/PI staining and image stream assays showed that CD4+CD8-, CD4-CD8+ and double negative iNKT cells are similarly able to induce DC apoptosis. Further MLR assays revealed that conventional DCs (cDCs) but not plasmacytoid DCs (pDCs) could induce alloreactive T-cell activation and proliferation. Interestingly, cDCs were also more susceptible to apoptosis induced by iNKT cells, which correlates with their higher CD1d expression, leading to a bias in favor of pDCs. Remarkably, these results could also be observed in GvHD patients. We propose a new mechanism how ex vivo expanded human iNKT cells prevent alloreactivity of T cells. iNKT cells modulate T-cell responses by selective apoptosis of DC subsets, resulting in suppression of T-cell activation and proliferation while enabling beneficial immune responses through pDCs.

scholarly journals Distinct Bioenergetic Features of Human Invariant Natural Killer T Cells Enable Retained Functions in Nutrient-Deprived States

2021 ◽  
Vol 12 ◽  
Author(s):  
Priya Khurana ◽  
Chakkapong Burudpakdee ◽  
Stephan A. Grupp ◽  
Ulf H. Beier ◽  
David M. Barrett ◽  
...  
Keyword(s):  
T Cells ◽  
Natural Killer ◽  
Metabolic Flux ◽  
Inkt Cell ◽  
Flux Analysis ◽  
Inkt Cells ◽  
Effector Functions ◽  
Functional Features ◽  
Invariant Natural Killer ◽  
Natural Killer T

Invariant natural killer T (iNKT) cells comprise a unique subset of lymphocytes that are primed for activation and possess innate NK-like functional features. Currently, iNKT cell-based immunotherapies remain in early clinical stages, and little is known about the ability of these cells to survive and retain effector functions within the solid tumor microenvironment (TME) long-term. In conventional T cells (TCONV), cellular metabolism is linked to effector functions and their ability to adapt to the nutrient-poor TME. In contrast, the bioenergetic requirements of iNKT cells – particularly those of human iNKT cells – at baseline and upon stimulation are not well understood; neither is how these requirements affect effector functions such as production of cytokines and cytolytic proteins. We find that unlike TCONV, human iNKT cells are not dependent upon glucose or glutamine for these effector functions upon stimulation with anti-CD3 and anti-CD28. Additionally, transcriptional profiling revealed that stimulated human iNKT cells are less glycolytic than TCONV and display higher expression of fatty acid oxidation (FAO) and adenosine monophosphate-activated protein kinase (AMPK) pathway genes. Furthermore, stimulated iNKT cells displayed higher mitochondrial mass and membrane potential relative to TCONV. Real-time Seahorse metabolic flux analysis revealed that stimulated human iNKT cells utilize fatty acids as substrates for oxidation more than stimulated TCONV. Together, our data suggest that human iNKT cells possess different bioenergetic requirements from TCONV and display a more oxidative metabolic program relative to effector TCONV. Importantly, iNKT cell-based immunotherapeutic strategies could co-opt such unique features of iNKT cells to improve their efficacy and longevity of anti-tumor responses.

scholarly journals Type I Natural Killer T Cells as Key Regulators of the Immune Response to Infectious Diseases

2020 ◽  
Vol 34 (2) ◽  
pp. e00232-20
Author(s):  
Nicolás M. S. Gálvez ◽  
Karen Bohmwald ◽  
Gaspar A. Pacheco ◽  
Catalina A. Andrade ◽  
Leandro J. Carreño ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Infectious Diseases ◽  
Natural Killer ◽  
Nkt Cells ◽  
Interleukin 4 ◽  
Type I ◽  
Inkt Cells ◽  
Class I Mhc ◽  
Natural Killer T

SUMMARYThe immune system must work in an orchestrated way to achieve an optimal response upon detection of antigens. The cells comprising the immune response are traditionally divided into two major subsets, innate and adaptive, with particular characteristics for each type. Type I natural killer T (iNKT) cells are defined as innate-like T cells sharing features with both traditional adaptive and innate cells, such as the expression of an invariant T cell receptor (TCR) and several NK receptors. The invariant TCR in iNKT cells interacts with CD1d, a major histocompatibility complex class I (MHC-I)-like molecule. CD1d can bind and present antigens of lipid nature and induce the activation of iNKT cells, leading to the secretion of various cytokines, such as gamma interferon (IFN-γ) and interleukin 4 (IL-4). These cytokines will aid in the activation of other immune cells following stimulation of iNKT cells. Several molecules with the capacity to bind to CD1d have been discovered, including α-galactosylceramide. Likewise, several molecules have been synthesized that are capable of polarizing iNKT cells into different profiles, either pro- or anti-inflammatory. This versatility allows NKT cells to either aid or impair the clearance of pathogens or to even control or increase the symptoms associated with pathogenic infections. Such diverse contributions of NKT cells to infectious diseases are supported by several publications showing either a beneficial or detrimental role of these cells during diseases. In this article, we discuss current data relative to iNKT cells and their features, with an emphasis on their driving role in diseases produced by pathogenic agents in an organ-oriented fashion.

scholarly journals Cancer Immunotherapeutic Potential of NKTT320, a Novel, Invariant, Natural Killer T Cell-Activating, Humanized Monoclonal Antibody

2020 ◽  
Vol 21 (12) ◽  
pp. 4317 ◽  
Author(s):  
Nishant P. Patel ◽  
Peng Guan ◽  
Devika Bahal ◽  
Tanwir Hashem ◽  
Felix Scheuplein ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
T Cell ◽  
Natural Killer ◽  
Cell Activation ◽  
Cell Receptor ◽  
Inkt Cell ◽  
Humanized Monoclonal Antibody ◽  
Cancer Immunotherapeutic ◽  
Invariant Natural Killer ◽  
Natural Killer T

Invariant natural killer T cells (iNKTs) directly kill tumor cells and trans-activate the anti-tumor functions of dendritic cells (DC), natural killer (NK) cells, and T and B cells. As such, iNKTs serve as a powerful tool for use in cell-based cancer immunotherapy. iNKT cell activation commonly requires engagement of the invariant T cell receptor (iTCR) by CD1d presenting glycolipid antigens. However, transformed cells often down-regulate CD1d expression, which results in a reduction of iNKT cell anti-tumor functions. One approach to circumvent this critical barrier to iNKT cell activation is to develop an agonistic antibody that binds directly to the iTCR without the requirement for CD1d-mediated antigen presentation. To this end, we have characterized the iNKT cell stimulatory properties of NKTT320, a novel, recombinant, humanized, monoclonal antibody that binds selectively and with high affinity to human iTCRs. Strikingly, immobilized NKTT320 mediated robust iNKT cell activation (upregulation of CD25 and CD69) and proliferation (carboxyfluorescein succinimidyl ester (CFSE) dilution), as well as Th1 and Th2 cytokine production. Additionally, iNKTs stimulated by plate-bound NKTT320 exhibited increased intracellular levels of granzyme B and degranulation (exposure of CD107 on the cell surface). Furthermore, both soluble and immobilized NKTT320 induced iNKT cell-mediated activation of bystander immune cells, suggesting that this novel anti-iTCR antibody facilitates both direct and indirect iNKT cell cytotoxicity. These studies are significant, as they provide a framework by which iNKT cell anti-cancer functions could be enhanced for therapeutic purposes.

Third Party Invariant Natural Killer T Cells Protect from Graft-Versus-Host Disease Lethality through Expansion of Donor CD4+FoxP3+ Regulatory T Cells

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3825-3825
Author(s):  
Dominik Schneidawind ◽  
Jeanette Baker ◽  
Corina Buechele ◽  
Everett H. Meyer ◽  
Robert S. Negrin
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Natural Killer ◽  
Graft Versus Host Disease ◽  
Adoptive Transfer ◽  
Third Party ◽  
Inkt Cells ◽  
Graft Versus Host ◽  
Donor T Cells ◽  
Invariant Natural Killer

Abstract Graft-versus-host disease (GVHD) is driven by extensive activation and proliferation of alloreactive donor T cells causing significant morbidity and mortality following allogeneic hematopoietic cell transplantation (HCT). Invariant natural killer T (iNKT) cells are potent regulators of immune responses in both humans (TCRα Vα24-Jα18) and mice (TCRα Vα14-Jα18). As the iNKT cell receptor and the glycolipid-presenting molecule CD1d interaction is highly conserved, we explored the role of adoptively transferred third party CD4+ iNKT cells in a murine model of allogeneic HCT. BALB/c (H-2Kd) recipient mice were irradiated with 8 Gy and transplanted with T cell-depleted bone marrow together with 1x106 CD4+/CD8+ T cells (Tcon) from C57BL/6 (H-2Kb) donor mice. Adoptive transfer of purified (>95%) 5x104 CD4+ iNKT cells from FVB/N (H-2Kq) third party mice resulted in a significant survival benefit (p<0.001) while retaining Tcon mediated graft-versus-tumor (GVT) effects against A20 lymphoma cells (p=0.002). Consistently, weight and GVHD scores improved in mice that received a single injection of third party CD4+ iNKT cells as compared to animals that received Tcon alone. Notably, CD4+ iNKT cells from third party mice were as protective as CD4+ iNKT cells from donor mice (p=0.50). Signal intensity deriving from expanding luciferase expressing alloreactive Tcon was significantly lower in animals treated with third party CD4+ iNKT cells (p=0.003). Interestingly, inhibition of Tcon proliferation was similar to animals that received CD4+ iNKT cells from donor mice (p=0.90). In addition, adoptive transfer of third party CD4+ iNKT cells promoted a Th2-biased cytokine response of alloreactive donor T cells. Although we found that third party CD4+ iNKT cells were rejected by day +10 after allogeneic HCT, adoptive transfer of these cells resulted in a robust expansion of luciferase expressing donor CD4+FoxP3+ regulatory T cells (Treg) as measured by bioluminescence imaging (p=0.006). Using FoxP3DTR C57BL/6 donor mice, depletion of Treg from the graft abrogated both donor Treg expansion and protection from GVHD lethality through third party CD4+ iNKT cells. We conclude that low numbers of highly purified and adoptively transferred third party CD4+ iNKT cells protect from lethal GVHD through activation and expansion of donor Treg with retained GVT effects. Despite the fact that iNKT cells are a rare cell population, the in vivo activity of small numbers of cells and feasibility of in vitro expansion provide the basis for clinical translation. Disclosures No relevant conflicts of interest to declare.

Relevance of sexual dimorphism to regulatory T cells: estradiol promotes IFN-γ production by invariant natural killer T cells

Blood ◽  
2005 ◽  
Vol 105 (6) ◽  
pp. 2415-2420 ◽  
Author(s):  
Pierre Gourdy ◽  
Luiza M. Araujo ◽  
Ren Zhu ◽  
Barbara Garmy-Susini ◽  
Séverine Diem ◽  
...  
Keyword(s):  
T Cells ◽  
Natural Killer ◽  
Interleukin 4 ◽  
Response To Treatment ◽  
Inkt Cells ◽  
Gender Dimorphism ◽  
Ifn Γ ◽  
Invariant Natural Killer ◽  
Natural Killer T

Abstract Mechanisms accounting for gender dimorphism during immune responses are still poorly understood. Since invariant natural killer T (iNKT) cells exert important regulatory functions through their capacity to produce both T helper 1 (Th1) and Th2 cytokines, we addressed the question of whether these activities could be modulated by sexual hormones. We found that in vivo challenge with the specific ligand of iNKT cells, α-galactosylceramide (α-GalCer), induced significantly higher concentrations of interferon γ (IFN-γ) in the serum of female than in that of male mice, while interleukin 4 (IL-4) production was not modified. In support of a crucial role of ovarian hormones in this phenomenon, a significant decrease of serum IFN-γ concentrations occurred in ovariectomized females, in response to treatment with α-GalCer, while orchidectomy affected neither IFN-γ nor IL-4 serum concentrations in males. The implication of estrogens in this selective enhancement of IFN-γ production by iNKT cells was demonstrated by (1) the increased α-GalCer–induced IFN-γ synthesis by iNKT cells upon both in vitro and in vivo exposure to estradiol and (2) the abolition of the sex-linked difference in α-GalCer–induced IFN-γ release in estrogen receptor α-deficient mice. These results provide the first evidence that estrogens influence iNKT cells leading to this gender dimorphism in their cytokine production profile.

scholarly journals Distinct bioenergetic features of human invariant natural killer T (iNKT) cells enable retained functions in nutrient-deprived states

2021 ◽  
Author(s):  
Priya Khurana ◽  
Chakkapong Burudpakdee ◽  
Stephan A. Grupp ◽  
Ulf H. Beier ◽  
David M. Barrett ◽  
...  
Keyword(s):  
Natural Killer ◽  
Metabolic Flux ◽  
Cytokine Production ◽  
Inkt Cell ◽  
Flux Analysis ◽  
Inkt Cells ◽  
Effector Functions ◽  
Functional Features ◽  
Invariant Natural Killer ◽  
Natural Killer T

ABSTRACTInvariant natural killer T (iNKT) cells comprise a unique subset of lymphocytes that are primed for activation and possess innate NK-like functional features. Currently, iNKT cell-based immunotherapies remain in early clinical stages, and little is known about the ability of these cells to survive and retain effector functions within the solid tumor microenvironment (TME) long-term. In conventional T cells (TCONV), cellular metabolism is linked to effector functions and their ability to adapt to the nutrient-poor TME. In contrast, the bioenergetic requirements of iNKT cells – particularly those of human iNKT cells – at baseline and upon stimulation are not well understood; neither is how these requirements affect cytokine production or anti-tumor effector functions. We find that unlike TCONV, human iNKT cells are not dependent upon glucose or glutamine for cytokine production and cytotoxicity upon stimulation with anti-CD3 and anti-CD28. Additionally, transcriptional profiling revealed that stimulated human iNKT cells are less glycolytic than TCONV and display higher expression of fatty acid oxidation (FAO) and adenosine monophosphate-activated protein kinase (AMPK) pathway genes. Furthermore, stimulated iNKT cells displayed higher mitochondrial mass and membrane potential relative to TCONV. Real-time Seahorse metabolic flux analysis revealed that stimulated human iNKT cells utilize fatty acids as substrates for oxidation more than stimulated TCONV. Together, our data suggest that human iNKT cells possess different bioenergetic requirements from TCONV and display a more memory-like metabolic program relative to effector TCONV. Importantly, iNKT cell-based immunotherapeutic strategies could co-opt such unique features of iNKT cells to improve their efficacy and longevity of anti-tumor responses.

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