scholarly journals Combined proinflammatory cytokine and cognate activation of invariant natural killer T cells enhances anti-DNA antibody responses

2020 ◽  
Vol 117 (16) ◽  
pp. 9054-9063 ◽  
Author(s):  
Saikiran K. Sedimbi ◽  
Thomas Hägglöf ◽  
Manasa G. Garimella ◽  
Shan Wang ◽  
Amanda Duhlin ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Natural Killer ◽  
Chronic Inflammation ◽  
Cell Activation ◽  
Fas Ligand ◽  
Nkt Cells ◽  
Autoreactive B Cells ◽  
Invariant Natural Killer ◽  
Natural Killer T

Invariant natural killer T (iNKT) cells serve as early rapid responders in the innate immune response to self-derived autoantigens and pathogen-derived danger signals and antigens. iNKT cells can serve both as helpers for effector B cells and negatively regulate autoreactive B cells. Specifically, iNKT cells drive B cell proliferation, class switch, and antibody production to induce primary antigen-specific immune responses. On the other hand, inflammasome-mediated activation drives accumulation of neutrophils, which license iNKT cells to negatively regulate autoreactive B cells via Fas ligand (FasL). This positions iNKT cells at an apex to support or inhibit B cell responses in inflammation. However, it is unknown which effector mechanism dominates in the face of cognate glycolipid activation during chronic inflammation, as might result from glycolipid vaccination or infection during chronic autoimmune disease. We stimulated iNKT cells by cognate glycolipid antigen α-galactosylceramide (αGalCer) and measured B cell activation during interleukin 18 (IL-18)-induced chronic inflammation. Moreover, glycolipid-activated iNKT cells increased the serum concentration of autoantibodies, frequency of germinal center (GC) B cells, and antigen-specific plasma cells induced during chronic IL-18–mediated inflammation, as compared with IL-18 alone. Further, activation of iNKT cells via cognate glycolipid during IL-18–mediated inflammation overrides the licensing function of neutrophils, instead inducing iNKT follicular helper (iNKTfh) cells that in turn promote autoimmunity. Thus, our data demonstrate that glycolipids which engage iNKT cells support antigen-specific B cell help during inflammasome-mediated inflammation.

scholarly journals CD1d-restricted Help To B Cells By Human Invariant Natural Killer T Lymphocytes

2003 ◽  
Vol 197 (8) ◽  
pp. 1051-1057 ◽  
Author(s):  
Grazia Galli ◽  
Sandra Nuti ◽  
Simona Tavarini ◽  
Luisa Galli-Stampino ◽  
Claudia De Lalla ◽  
...  
Keyword(s):  
B Cells ◽  
T Lymphocytes ◽  
Natural Killer ◽  
Nkt Cells ◽  
Immunoglobulin Production ◽  
Direct Role ◽  
Invariant Nkt Cells ◽  
Invariant Natural Killer ◽  
Natural Killer T

Invariant natural killer T (NKT) cells are a highly conserved subset of T lymphocytes expressing a semi-invariant T cell receptor (TCR), which is restricted to CD1d and specific for the glycosphingolipid antigen α-galactosylceramide. Their ability to secrete a variety of cytokines, which in turn modulate the activation of cells of both innate and acquired immune responses, suggests that invariant NKT cells exert a regulatory role mainly via indirect mechanisms. A relevant question is whether invariant NKT cells can directly help B cells. We document here that human invariant NKT cells are as efficient as conventional CD4+ Th0 lymphocytes in promoting proliferation of autologous memory and naive B lymphocytes in vitro, and in inducing immunoglobulin production. Help to B cells by invariant NKT cells is CD1d-dependent and delivered also in the absence of α-galactosylceramide, suggesting that NKT cells recognize an endogenous ligand presented by CD1d on B cells. The two major subsets of invariant NKT cells, CD4+ and double negative (CD4−CD8−), express comparable levels of CD40 ligand and cytokines, but differ in helper functions. Indeed, both subsets induce similar levels of B cell proliferation, whereas CD4+ NKT cells induce higher levels of immunoglobulin production. These results suggest a direct role for invariant NKT cells in regulating B lymphocyte proliferation and effector functions.

scholarly journals Transcriptome and Function of Novel Immunosuppressive Autoreactive Invariant Natural Killer T Cells That Are Absent in Progressive Multiple Sclerosis

2021 ◽  
Vol 8 (6) ◽  
pp. e1065
Author(s):  
Belinda Carrión ◽  
Yawei Liu ◽  
Mahdieh Hadi ◽  
Jon Lundstrom ◽  
Jeppe Romme Christensen ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
T Cells ◽  
Natural Killer ◽  
Protein Level ◽  
Fas Ligand ◽  
Nkt Cells ◽  
Tnf Receptor ◽  
Inkt Cells ◽  
Invariant Natural Killer ◽  
Natural Killer T

Background and ObjectiveThe aim of this study was to determine whether natural killer T (NKT) cells, including invariant (i) NKT cells, have clinical value in preventing the progression of multiple sclerosis (MS) by examining the mechanisms by which a distinct self-peptide induces a novel, protective invariant natural killer T cell (iNKT cell) subset.MethodsWe performed a transcriptomic and functional analysis of iNKT cells that were reactive to a human collagen type II self-peptide, hCII707-721, measuring differentially induced genes, cytokines, and suppressive capacity.ResultsWe report the first transcriptomic profile of human conventional vs novel hCII707-721–reactive iNKT cells. We determined that hCII707-721 induces protective iNKT cells that are found in the blood of healthy individuals but not progressive patients with MS (PMS). By transcriptomic analysis, we observed that hCII707-721 promotes their development and proliferation, favoring the splicing of full-length AKT serine/threonine kinase 1 (AKT1) and effector function of this unique lineage by upregulating tumor necrosis factor (TNF)-related genes. Furthermore, hCII707-721–reactive iNKT cells did not upregulate interferon (IFN)-γ, interleukin (IL)-4, IL-10, IL-13, or IL-17 by RNA-seq or at the protein level, unlike the response to the glycolipid alpha-galactosylceramide. hCII707-721–reactive iNKT cells increased TNFα only at the protein level and suppressed autologous-activated T cells through FAS-FAS ligand (FAS-FASL) and TNFα-TNF receptor I signaling but not TNF receptor II.DiscussionBased on their immunomodulatory properties, NKT cells have a potential value in the treatment of autoimmune diseases, such as MS. These significant findings suggest that endogenous peptide ligands can be used to expand iNKT cells, without causing a cytokine storm, constituting a potential immunotherapy for autoimmune conditions, including PMS.

scholarly journals Invariant natural killer T cells direct B cell responses to cognate lipid antigen in an IL-21-dependent manner

2011 ◽  
Vol 13 (1) ◽  
pp. 44-50 ◽  
Author(s):  
Irah L King ◽  
Anne Fortier ◽  
Michael Tighe ◽  
John Dibble ◽  
Gerald F M Watts ◽  
...  
Keyword(s):  
T Cells ◽  
B Cell ◽  
Natural Killer ◽  
Natural Killer T Cells ◽  
Dependent Manner ◽  
Cell Responses ◽  
Lipid Antigen ◽  
Killer T Cells ◽  
Invariant Natural Killer ◽  
Natural Killer T

scholarly journals Mechanisms of Innate Lymphoid Cell and Natural Killer T Cell Activation during Mucosal Inflammation

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
David Nau ◽  
Nora Altmayer ◽  
Jochen Mattner
Keyword(s):  
T Cell ◽  
Natural Killer ◽  
T Cell Activation ◽  
Cell Activation ◽  
Inflammatory Responses ◽  
Adaptive Immune System ◽  
Nkt Cells ◽  
Lymphoid Cells ◽  
Mucosal Inflammation ◽  
Natural Killer T

Mucosal surfaces in the airways and the gastrointestinal tract are critical for the interactions of the host with its environment. Due to their abundance at mucosal tissue sites and their powerful immunomodulatory capacities, the role of innate lymphoid cells (ILCs) and natural killer T (NKT) cells in the maintenance of mucosal tolerance has recently moved into the focus of attention. While NKT cells as well as ILCs utilize distinct transcription factors for their development and lineage diversification, both cell populations can be further divided into three polarized subpopulations reflecting the distinction into Th1, Th2, and Th17 cells in the adaptive immune system. While bystander activation through cytokines mediates the induction of ILC and NKT cell responses, NKT cells become activated also through the engagement of their canonical T cell receptors (TCRs) by (glyco)lipid antigens (cognate recognition) presented by the atypical MHC I like molecule CD1d on antigen presenting cells (APCs). As both innate lymphocyte populations influence inflammatory responses due to the explosive release of copious amounts of different cytokines, they might represent interesting targets for clinical intervention. Thus, we will provide an outlook on pathways that might be interesting to evaluate in this context.

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.

scholarly journals Natural Killer T Cells in Various Mouse Models of Hepatitis

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Jun Guan ◽  
Gang Wang ◽  
Qin Yang ◽  
Chao Chen ◽  
Jingwen Deng ◽  
...  
Keyword(s):  
Natural Killer ◽  
Mouse Models ◽  
Fas Ligand ◽  
Basic Research ◽  
Neutrophil Infiltration ◽  
Nkt Cells ◽  
Liver Injuries ◽  
Integral Role ◽  
Natural Killer T

Natural killer T (NKT) cells are a key component of innate immunity. Importantly, a growing body of evidence indicates that NKT cells play an integral role in various acute and chronic liver injuries. NKT cells participate in the progression of an injury through the secretion of cytokines, which promote neutrophil infiltration and enhance Fas ligand (FasL) and granzyme-mediated NKT cytotoxic activity. Therefore, examining the role of NKT cells in hepatic disease is critical for a comprehensive understanding of disease pathogenesis and may provide insight into novel approaches for treatment. For more than a century, mouse models that imitate the physiopathological conditions of human disease have served as a critical tool in biological and medical basic research, including studies of liver disease. Here, we review the role of NKT cells in various mouse models of hepatitis.

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