CD1d-Restricted Natural Killer T Cells: Roles in Tumor Immunosurveillance and Tolerance

Abstract

Natural killer T (NKT) cells are a heterogeneous group of T cells that share properties characteristic of both T cells and NK cells and possess a variety of unusual properties with regard to antigen recognition and function. Many of these cells recognize the non-polymorphic CD1d molecule, an antigen-presenting molecule that binds self- and foreign lipids. The best known subset of CD1d-dependent NKT cells expresses an invariant T cell receptor a (TCR-a) chain. These are referred to as type I or invariant NKT cells (iNKT cells). These cells, which are the main focus of the current review, are conserved between humans and mice. Detailed work in mouse models has implicated iNKT cells in many immunological processes, and related studies in humans suggest important roles in health and disease. By virtue of their ability to produce a variety of immunoregulatory cytokines and to acquire a broad spectrum of effector activities, iNKT cells may both induce or suppress immune reactions in healthy and pathologic settings. We review the role of iNKT cells in the induction of tolerance to solid organ and hematologic transplants and malignancies, as well as their importance in maintaining normal self-tolerance and involvement in autoimmune diseases.

Glucose Metabolism Disorders and the Risk of Cancer

“…It is a diverse group of cells, named NKT due to the presence of surface markers characteristic for both T and NK cells. NKT constitute only 1% of peripheral blood T lymphocytes (Balato et al 2009;Hammond et al 1999;Jerud et al 2006;Montoya et al 2007) although there has been the case described of a person with a much higher percentage (over 3% of mononuclear cells peripheral blood and more than 5% of all T lymphocyte cells), coming from a family where type 1 and type 2 diabetes was diagnosed ). Despite the small percentage of these cells they contribute significantly in regulating the immune response (Bendelac et al 2007;Mercer et al 2005) and defense against cancer (Berzofsky and Terabe 2009;Smyth et al 2000;Swann et al 2009).…”

Leishmania donovani skews the CD56+ Natural Killer T cell response during human visceral leishmaniasis

“…NKT cells are also a key regulator of innate and acquired immunity [9]. Although, the percent of NKT cell subsets, which share phenotypic markers of NK and T cells, including CD16, CD56, CD161, CD3 and CD4/8 represents only 0.1% of the peripheral blood T cells [10], rapidly produce large amounts of cytokines [11]. Three categories of NKT cells have been identified based on a diverse range of T cell receptors and their restriction to different antigen presenting molecules.…”

Molecular basis of carcinogenesis in diabetic patients (Review)

“…nKt cells are the subject of many studies evaluating the role of the immune system in autoimmune diseases and malignancy (77)(78)(79)(80). they are aptly named 'natural killer t cells' due to the cells possessing surface t-cell markers (cD3-tcr complex), surface nK cell markers (cD56, 161 and 94), and marker cD57.…”