INTRODUCTION Natural killer T (NKT) cells are involved in the antitumor response by direct cytotoxicity and indirectly through activation of effector cells. Recent studies have shown a relationship between the number and function of NKT cells and clinical outcomes. NKT cells seem to represent a promising tool for immunotherapy of cancer. THE AIM OF THE STUDY The aim of the study was to evalua...

Natural killer T (NKT) cells are important regulators of the immune system, but their trafficking machinery, including expression of chemokine receptors, has been poorly defined. Unlike other conventional T-cell populations, we show that most NKT cells express receptors for extralymphoid tissue or inflammationrelated chemokines (CCR2, CCR5, and CXCR3), while few NKT cells express lymphoid tissu...

Common variable immunodeficiency disorder (CVID) is the commonest cause of primary antibody failure in adults and children, and characterized clinically by recurrent bacterial infections and autoimmune manifestations. Several innate immune defects have been described in CVID, but no study has yet investigated the frequency, phenotype or function of the key regulatory cell population, natural ki...

NKT cells are a regulatory subset of T lymphocytes with immune modulatory effects and an important role in anti-tumor immunity. The feasibility of "ex-vivo education" of NKT cells has recently been demonstrated. To evaluate the anti-tumor effect of ex-vivo immune-modulated NKT lymphocytes in a murine model of hepatocellular carcinoma. Athymic Balb/C mice were sublethally irradiated and transpla...

Natural killer T (NKT) cells are a small population of lymphocytes that possess characteristics of both innate and adaptive immune cells. They are uniquely poised to respond rapidly to infection and inflammation and produce cytokines that critically shape the ensuing adaptive cellular response. Therefore, they represent promising therapeutic targets. In cancer, NKT cells are attributed a role i...

The importance of immunoregulatory T cells has become increasingly apparent. Both CD4+CD25+ T cells and CD1d-restricted NKT cells have been reported to down-regulate tumor immunity in mouse tumor models. However, the relative roles of both T cell populations have rarely been clearly distinguished in the same tumor models. In addition, CD1d-restricted NKT cells have been reported to play a criti...

Human Va24 NKT cells with an invariant TCR (Va24-JaQ) have been shown to be specifically activated by synthetic glycolipids such as a-galactosylceramide and a-glucosylceramide in a CD1d-restricted and Va24 TCR-mediated manner. We recently characterized Va24 CD4 CD8 double negative (DN) NKT cells using a-galactosylceramide-pulsed monocyte-derived dendritic cells. Here, we compare Va24 CD4 NKT ce...

CD1d expressing dendritic cells (DCs) are good glyco-lipid antigen presenting cells for NKT cells. However, resting B cells are very weak stimulators for NKT cells. Although α-galactosylceramide (α-GalCer) loaded B cells can activate NKT cells, it is not well defined whether B cells interfere NKT cell stimulating activity of DCs. Unexpectedly, we found in this study that B cells can promote Th1...

The Tec family tyrosine kinase, Itk, regulates signaling downstream of the TCR. The absence of Itk in CD4(+) T cells results in impaired Th2 responses along with defects in maturation, cytokine production, and survival of iNKT cells. Paradoxically, Itk(-/-) mice have spontaneously elevated serum IgE levels, resulting from an expansion of the Vγ1.1(+)Vδ6.3(+) subset of γδ T cells, known as γδ NK...

Human Va24 NKT cells bearing an invariant Va24JaQ antigen receptor, the counterpart of the murine Va14 NKT cells, are activated by the specific ligand, a-galactosylceramide (a-GalCer) in a CD1d-dependent manner. Here, we demonstrate that the a-GalCer-activated Va24 NKT cells exert a potent perforin-dependent cytotoxic activity against a wide variety of human tumor cell lines. In addition, we de...