Circulating Invariant Natural Killer T (iNKT) Cell Frequencies And Subset Distribution Are Associated With Lung Disease Severity And Clinical Status In Sarcoidosis

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.

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Invariant natural killer T (iNKT) cell deficiency in chronic mucocutaneous candidiasis – A consequence or a cause?

Immunology Letters ◽

10.1016/j.imlet.2010.09.014 ◽

2011 ◽

Vol 135 (1-2) ◽

pp. 180-183 ◽

Cited By ~ 2

Author(s):

Wan-Fai Ng ◽

Susan J. Tudhope ◽

Alexei von Delwig ◽

Desa Lilic

Keyword(s):

Natural Killer ◽

Inkt Cell ◽

Chronic Mucocutaneous Candidiasis ◽

Mucocutaneous Candidiasis ◽

Invariant Natural Killer ◽

Natural Killer T

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

10.1101/2021.04.29.442021 ◽

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

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.34.suppl_1.541 ◽

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.

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TNF receptor associated factor 3 plays a key role in development and function of invariant natural killer T cells

Journal of Experimental Medicine ◽

10.1084/jem.20122135 ◽

2013 ◽

Vol 210 (6) ◽

pp. 1079-1086 ◽

Cited By ~ 23

Author(s):

Zuoan Yi ◽

Laura L. Stunz ◽

Gail A. Bishop

Keyword(s):

Natural Killer ◽

Developmental Stages ◽

Critical Role ◽

Inkt Cell ◽

Tnf Receptor ◽

Inkt Cells ◽

Tcr Signaling ◽

Associated Factor ◽

Invariant Natural Killer ◽

Natural Killer T

TCR signaling is a prerequisite for early stage development of invariant natural killer T (iNKT) cells, whereas IL-15 signaling is required for expansion and maturation at later stages. In this study, we show that TNF receptor associated factor 3 (TRAF3) plays a critical role in the transition between these two distinct signaling pathways and developmental stages. TRAF3-deficient iNKT cells in CD4CreTRAF3flox/flox (T-TRAF3−/−) mice exhibit defective up-regulation of T-bet and CD122, two critical molecules for IL-15 signaling, and as a consequence, IL-15–mediated iNKT cell proliferation and survival are impaired. Consistently, development of iNKT cells in T-TRAF3−/− mice shows a major defect at developmental stages 2 and 3, but not stages 0 and 1. We further demonstrated that defective T-bet up-regulation occurring during the stage 1 to stage 2 transition results from reduced TCR signaling in TRAF3−/− iNKT cells. In addition, mature TRAF3−/− iNKT cells displayed defective cytokine responses upon TCR stimulation. Collectively, our results reveal that by modulating the relative strength of TCR signaling, TRAF3 is an important regulator of iNKT cell development and functions.

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Switching Invariant Natural Killer T (iNKT) Cell Response from Anticancerous to Anti-Inflammatory Effect: Molecular Bases

Journal of Medicinal Chemistry ◽

10.1021/jm4010863 ◽

2014 ◽

Vol 57 (13) ◽

pp. 5489-5508 ◽

Cited By ~ 38

Author(s):

Xavier Laurent ◽

Benjamin Bertin ◽

Nicolas Renault ◽

Amaury Farce ◽

Silvia Speca ◽

...

Keyword(s):

Natural Killer ◽

Cell Response ◽

Inkt Cell ◽

Anti Inflammatory ◽

Molecular Bases ◽

Invariant Natural Killer ◽

Inflammatory Effect ◽

Natural Killer T

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Invariant Natural Killer T-cell Dynamics in Human Immunodeficiency Virus–associated Tuberculosis

Clinical Infectious Diseases ◽

10.1093/cid/ciz501 ◽

2019 ◽

Vol 70 (9) ◽

pp. 1865-1874 ◽

Cited By ~ 6

Author(s):

Naomi F Walker ◽

Charles Opondo ◽

Graeme Meintjes ◽

Nishtha Jhilmeet ◽

Jon S Friedland ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Antiretroviral Therapy ◽

Natural Killer ◽

Inkt Cell ◽

Inkt Cells ◽

Cross Sectional ◽

Immunodeficiency Virus ◽

Invariant Natural Killer ◽

Hiv 1 ◽

Natural Killer T

Abstract Background Tuberculosis (TB) is the leading cause of mortality and morbidity in people living with human immunodeficiency virus (HIV) infection (PLWH). PLWH with TB disease are at risk of the paradoxical TB-associated immune reconstitution inflammatory syndrome (TB-IRIS) when they commence antiretroviral therapy. However, the pathophysiology is incompletely understood and specific therapy is lacking. We investigated the hypothesis that invariant natural killer T (iNKT) cells contribute to innate immune dysfunction associated with TB-IRIS. Methods In a cross-sectional study of 101 PLWH and HIV-uninfected South African patients with active TB and controls, iNKT cells were enumerated using α-galactosylceramide-loaded CD1d tetramers and subsequently functionally characterized by flow cytometry. In a second study of 49 people with HIV type 1 (HIV-1) and active TB commencing antiretroviral therapy, iNKT cells in TB-IRIS patients and non-IRIS controls were compared longitudinally. Results Circulating iNKT cells were reduced in HIV-1 infection, most significantly the CD4+ subset, which was inversely associated with HIV-1 viral load. iNKT cells in HIV-associated TB had increased surface CD107a expression, indicating cytotoxic degranulation. Relatively increased iNKT cell frequency in patients with HIV-1 infection and active TB was associated with development of TB-IRIS following antiretroviral therapy initiation. iNKT cells in TB-IRIS were CD4+CD8– subset depleted and degranulated around the time of TB-IRIS onset. Conclusions Reduced iNKT cell CD4+ subsets as a result of HIV-1 infection may skew iNKT cell functionality toward cytotoxicity. Increased CD4– cytotoxic iNKT cells may contribute to immunopathology in TB-IRIS.

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Graft invariant natural killer T-cell dose predicts risk of acute graft-versus-host disease in allogeneic hematopoietic stem cell transplantation

Blood ◽

10.1182/blood-2011-11-389304 ◽

2012 ◽

Vol 119 (21) ◽

pp. 5030-5036 ◽

Cited By ~ 77

Author(s):

Aristeidis Chaidos ◽

Scott Patterson ◽

Richard Szydlo ◽

Mohammed Suhail Chaudhry ◽

Francesco Dazzi ◽

...

Keyword(s):

Stem Cell ◽

T Cell ◽

Natural Killer ◽

Inkt Cell ◽

Inkt Cells ◽

Cell Dose ◽

Grade Ii ◽

Clinically Significant ◽

Invariant Natural Killer ◽

Natural Killer T

Abstract Invariant natural killer T (iNKT) cells are powerful immunomodulatory cells that in mice regulate a variety of immune responses, including acute GVHD (aGVHD). However, their clinical relevance and in particular their role in clinical aGVHD are not known. We studied whether peripheral blood stem cell (PBSC) graft iNKT-cell dose affects on the occurrence of clinically significant grade II-IV aGVHD in patients (n = 57) undergoing sibling, HLA-identical allogeneic HSCT. In multivariate analysis, CD4− iNKT-cell dose was the only graft parameter to predict clinically significant aGVHD. The cumulative incidence of grade II-IV aGVHD in patients receiving CD4− iNKT-cell doses above and below the median were 24.2% and 71.4%, respectively (P = .0008); low CD4− iNKT-cell dose was associated with a relative risk of grade II-IV aGVHD of 4.27 (P = .0023; 95% CI, 1.68-10.85). Consistent with a role of iNKT cells in regulating aGVHD, in mixed lymphocyte reaction assays, CD4− iNKT cells effectively suppressed T-cell proliferation and IFN-γ secretion in a contact-dependent manner. In conclusion, higher doses of CD4− iNKT cells in PBSC grafts are associated with protection from aGVHD. This effect could be harnessed for prevention of aGVHD.

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