Search results for "Natural Killer T-Cells"
showing 10 items of 10 documents
Invariant natural killer T cells act as an extravascular cytotoxic barrier for joint-invading Lyme Borrelia
2014
CXCR6-GFP(+) cells, which encompass 70% invariant natural killer T cells (iNKT cells), have been found primarily patrolling inside blood vessels in the liver. Although the iNKT cells fail to interact with live pathogens, they do respond to bacterial glycolipids presented by CD1d on liver macrophage that have caught the microbe. In contrast, in this study using dual laser multichannel spinning-disk intravital microscopy of joints, the CXCR6-GFP, which also made up 60-70% iNKT cells, were not found in the vasculature but rather closely apposed to and surrounding the outside of blood vessels, and to a lesser extent throughout the extravascular space. These iNKT cells also differed in behavior,…
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 …
Invariant NKT cells are expanded in peripheral blood but are undetectable in salivary glands of patients with primary Sjögren's syndrome
2016
OBJECTIVES: Invariant NKT (iNKT) cells play a role in regulating the function of autoreactive B cells before their entry into germinal centres. Absence and/or reduction of iNKT cells have been demonstrated in patients with systemic lupus erythematosus (SLE) together with an increase of autoreactive B cell activity. Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease in which lymphocyte infiltration and organisation in lymphoid structures of inflamed salivary glands occurs. The aim of the study was to investigate the percentage and function of iNKT in the salivary glands and peripheral blood of patients with pSS. METHODS: Minor salivary gland biopsies were obtained from patient…
T cells mediate autoantibody-induced cutaneous inflammation and blistering in epidermolysis bullosa acquisita
2016
AbstractT cells are key players in autoimmune diseases by supporting the production of autoantibodies. However, their contribution to the effector phase of antibody-mediated autoimmune dermatoses, i.e., tissue injury and inflammation of the skin, has not been investigated. In this paper, we demonstrate that T cells amplify the development of autoantibody-induced tissue injury in a prototypical, organ-specific autoimmune disease, namely epidermolysis bullosa acquisita (EBA) – characterized and caused by autoantibodies targeting type VII collagen. Specifically, we show that immune complex (IC)-induced inflammation depends on the presence of T cells – a process facilitated by T cell receptor (…
β2Integrin deficiency yields unconventional double-negative T cells distinct from mature classical natural killer T cells in mice
2009
Expressed on leucocytes, beta(2) integrins (CD11/CD18) are specifically involved in leucocyte function. Using a CD18-deficient (CD18(-/-)) mouse model, we here report on their physiological role in lymphocyte differentiation and trafficking. CD18(-/-) mice present with a defect in the distribution of lymphocytes with highly reduced numbers of naïve B and T lymphocytes in inguinal and axillary lymph nodes. In contrast, cervical lymph nodes were fourfold enlarged harbouring unconventional T-cell receptor-alphabeta (TCR-alphabeta) and TCR-gammadelta CD3(+) CD4(-) CD8(-) (double-negative; DN) T cells that expanded in situ. Using adoptive transfer experiments, we found that these cells did not h…
The janus face of NKT cell function in autoimmunity and infectious diseases
2018
Natural killer T cells (NKT) are a subset of T lymphocytes bridging innate and adaptive immunity. These cells recognize self and microbial glycolipids bound to non-polymorphic and highly conserved CD1d molecules. Three NKT cell subsets, type I, II and NKT-like expressing different antigen receptors (TCR) were described and TCR activation promotes intracellular events leading to specific functional activities. NKT can exhibit different functions depending on the secretion of soluble molecules and the interaction with other cell types. NKT cells act as regulatory cells in the defence against infections but, on the other hand, their effector functions can be involved in the pathogenesis of sev…
Invariant natural killer T cells treated with rapamycin or transforming growth factor-β acquire a regulatory function and suppress T effector lymphoc…
2015
Invariant natural killer T cells treated with rapamycin or transforming growth factor-β acquire a regulatory function and suppress T effector lymphocytes
Invariant NKT Cells and Rheumatic Disease: Focus on Primary Sjogren Syndrome.
2019
Primary Sjogren syndrome (pSS) is a complex autoimmune disease mainly affecting salivary and lacrimal glands. Several factors contribute to pSS pathogenesis; in particular, innate immunity seems to play a key role in disease etiology. Invariant natural killer (NK) T cells (iNKT) are a T-cell subset able to recognize glycolipid antigens. Their function remains unclear, but studies have pointed out their ability to modulate the immune system through the promotion of specific cytokine milieu. In this review, we discussed the possible role of iNKT in pSS development, as well as their implications as future markers of disease activity.
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…
Altered CD94/NKG2A and perforin expression reduce the cytotoxic activity in malignant pleural effusions.
2010
CD94/NKG2A is an inhibitory receptor expressed by NK cells and cytotoxic lymphocytes and, upon activation by HLA-E, downregulates the cytolytic activities of these cells thus representing a tumour immune escape mechanism. This study was aimed at assessing whether cytotoxic lymphocytes (CD8+) and NK cells from malignant pleural effusions have a deregulated expression of CD94/NKG2A. The expression of membrane CD94/NKG2A and perforin was evaluated by flow-cytometry in CD8+ and NK cells from pleural effusions and autologous peripheral blood of cancer (n=19) and congestive heart failure (CHF) (n=11) patients. Intracellular CD94/NKG2A expression was evaluated by flow-cytometry in pleural effusion…