Search results for "Natural killer T cell"
showing 10 items of 100 documents
Human intestinal Vdelta1+ lymphocytes recognize tumor cells of epithelial origin.
1996
gammadelta T cells can be grouped into discrete subsets based upon their expression of T cell receptor (TCR) variable (V) region families, their tissue distribution, and their specificity. Vdelta2+ T cells constitute the majority of gammadelta T cells in peripheral blood whereas Vdelta1+T cells reside preferentially in skin epithelium and in the intestine. gammadelta T cells are envisioned as first line host defense mechanisms capable of providing a source of immune effector T cells and immunomodulating cytokines such as interleukin (IL) 4 or interferon (IFN) gamma. We describe here the fine specificity of three distinct gammadelta+ tumor-infiltrating lymphocytes (TIL) obtained from patient…
Tonic T cell signalling and T cell tolerance as opposite effects of self-recognition on dendritic cells.
2010
Naive T cells spend most of their time scanning the surface of dendritic cells (DCs), indicating that self-MHC/T cell receptor (TCR) interactions between these immune cells occur routinely in peripheral organs during the steady state. Peripheral self-MHC recognition on DCs drives seemingly opposing effects in the absence of inflammatory stimuli such as deletion of certain self-reactive T cells as well as maintenance of the T cell responsiveness to antigen, both of which shape the T cell repertoire and regulate T cell responses. Here we review recent data on the role of self-MHC recognition on steady-state DCs in the periphery and propose that interactions between T cells and steady-state DC…
With a little help from my old T cell: Memory follicular T helper cells driving autoimmunity?
2014
It has long been known that the B cell repertoire includes cells that are capable of producing autoantibodies and that these cells can be found in humans and also in wild type strains of laboratory mice; however, normally, these B cells do not give rise to plasma cells, and thus do not fulfil their autoimmune potential. In this issue of the European Journal of Immunology, Nusser et al. [Eur. J. Immunol. 2014. 44: 2893–2902] dissect the mechanism by which these B cells are activated and autoantibodies are produced. The authors demonstrate that T cells, most likely antigen-specific, which accumulate with age or as a result of homeostatic proliferation, provide essential help to these autoreac…
An innate cell-mediated, murine ulcerative colitis-like syndrome in the absence of nuclear factor of activated T cells.
2004
Abstract Background & Aims: Nuclear factor of activated T cells transcription factors plays a central role in immunity by regulating the expression of multiple cytokines and other regulatory molecules, many of which have been heavily implicated in the pathogenesis of inflammatory bowel disease. However, few studies have directly investigated the nuclear factor of activated T cells proteins in inflammatory bowel disease. We describe here a specific role for nuclear factor of activated T cells c2 in the pathogenesis of murine inflammatory bowel disease. Methods: Mice deficient for nuclear factor of activated T cells c2, recombinase activating gene-2, or both and transgenic or nontransgenic fo…
Tolerance without clonal expansion: self-antigen-expressing B cells program self-reactive T cells for future deletion.
2008
Abstract B cells have been shown in various animal models to induce immunological tolerance leading to reduced immune responses and protection from autoimmunity. We show that interaction of B cells with naive T cells results in T cell triggering accompanied by the expression of negative costimulatory molecules such as PD-1, CTLA-4, B and T lymphocyte attenuator, and CD5. Following interaction with B cells, T cells were not induced to proliferate, in a process that was dependent on their expression of PD-1 and CTLA-4, but not CD5. In contrast, the T cells became sensitive to Ag-induced cell death. Our results demonstrate that B cells participate in the homeostasis of the immune system by abl…
Disruption of T helper 2-immune responses in Epstein–Barr virus-induced gene 3-deficient mice
2002
Epstein–Barr virus-induced gene 3 (EBI3) is a widely expressed IL-12p40-related protein that associates as a heterodimer with either IL-12p35 or an IL-12p35 homologue, p28, to create a new cytokine (IL-27). To define the function of EBI3in vivo, we generated knockout mice in which theebi3gene was targeted by homologous recombination. EBI3−/−mice exhibited normal numbers of both naive and mature CD4+and CD8+T cells and B cells, but markedly decreased numbers of invariant natural killer T cells (iNKT) as defined by staining with an α-galactosylceramide (αGalCer)-loaded CD1d-tetramer. iNKT cells from EBI3−/−mice exhibited decreased IL-4 and, to a lesser extent, IFN-γ production after αGalCer s…
Immune regulation by regulatory T cells: implications for transplantation.
2003
Item does not contain fulltext The induction of antigen-specific T cell tolerance and its maintenance in the periphery are critical for the immune system to prevent autoaggressive immune responses. Our current state of knowledge about the immunoregulatory mechanisms responsible for T cell tolerance in the periphery offers new possibilities for immunomodulation to prevent transplant rejection as well as to diminish autoimmune reaction or chronic allergy. There is growing evidence that dendritic cells, besides their well-known T cell stimulatory functions, also maintain and regulate T cell tolerance in the periphery. This control function is exerted by certain maturation stages and subsets of…
SAT0373 Role of Inkt Cells in Patients with Primary Sjogren Syndrome
2015
Background iNKT cells represent a T cell subset at the bridge between innate and adaptive immunity, playing a role in regulating auto-antibody-producing B cells before their entry into germinal centers. Therefore the absence and/or reduction of iNKT cells seem to increase auto-reactive B cell activation. Primary Sjogren9s syndrome (pSS) is a systemic autoimmune disease in which lymphocyte infiltration and organization in lymphoid structures of inflamed salivary glands occur. Objectives The aim of this study was to investigate the frequency of iNKT in the salivary glands and peripheral blood of patients with pSS and their function by using CD1d/aGalactosylceramide (aGalaCer) tetramers. Metho…
Immune Modulating Effects of NKT Cells in a Physiologically Low Dose Leishmania major Infection Model after αGalCer Analog PBS57 Stimulation
2014
Leishmaniasis is a parasitic infection affecting ∼12 million people worldwide, mostly in developing countries. Treatment options are limited and no effective vaccines exist to date. Natural Killer T (NKT) cells are a conserved innate-like lymphocyte population with immunomodulating effects in various settings. A number of reports state a role of NKT cells in different models of Leishmania infection. Here, we investigated the effect of NKT cells in a physiologically relevant, intradermal low dose infection model. After inoculation of 103 infectious-stage L. major, comparable numbers of skin-immigrating NKT cells in both susceptible BALB/c mice and resistant C57BL/6 mice were noted. Compared …
Detection of natural killer T cells in mice infected with Rickettsia conorii.
2013
Little information is available regarding the role of natural killer T (NKT) cells during the early stage of Rickettsia conorii infection. Herein, C3H/HeN mice were infected with the Malish 7 strain of R. conorii. Splenocytes from these mice were analysed in the early stage of the infection by flow cytometry and compared with uninfected controls. Our results showed an increase in NKT cells in infected mice. Additionally, NKT interleukin (IL)-17(+) cells increased three days after infection, together with a concurrent decrease in the relative amount of NKT interferon (IFN)-γ(+) cells. We also confirmed a higher amount of NK IFN-γ(+) cells in infected mice. Taken together, our data showed tha…