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...

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 2/2 mice have spontaneously elevated serum IgE levels, resulting from an expansion of the Vg1.1 + Vd6.3 + subset of gd T cells, known as gd NKT c...

Airway hyperreactivity (AHR), eosinophilic inflammation with a Th2-type cytokine profile, and specific Th2-mediated IgE production characterize allergic asthma. In this paper, we show that OVA-immunized Jalpha18(-/-) mice, which are exclusively deficient in the invariant Valpha14(+) (iValpha14), CD1d-restricted NKT cells, exhibit impaired AHR and airway eosinophilia, decreased IL-4 and IL-5 pro...

Thymic development of αβ T lymphocytes into invariant natural killer (NK) T cells depends on their selection via agonistic lipid antigen presented by CD1d. If successful, newly selected NKT cells gain effector functions already in the thymus. Some γδ T cell subsets also acquire effector functions in the thymus. However, it is not clear whether agonistic TCR stimulation is involved in thymic γδ ...

BACKGROUND Dendritic cells (DC) can act tolerogenic at a semi-mature stage by induction of protective CD4(+) T cell and NKT cell responses. METHODOLOGY/PRINCIPAL FINDINGS Here we studied the role of the co-inhibitory molecule B7-H1 (PD-L1, CD274) on semi-mature DC that were generated from bone marrow (BM) cells of B7-H1(-/-) mice and applied to the model of Experimental Autoimmune Encephalomy...

Human natural killer (NK) T cells are unique T lymphocytes that express an invariant T cell receptor (TCR) Valpha24-Vbeta11 and have been implicated to play a role in various diseases. A subset of NKT cells express CD4 and hence are potential targets for human immunodeficiency virus (HIV)-1 infection. We demonstrate that both resting and activated human Valpha24(+) T cells express high levels o...

The respiratory mucosa is a major site for pathogen invasion and, hence, a site requiring constant immune surveillance. The type I, semi-invariant natural killer T (NKT) cells are enriched within the lung vasculature. Despite optimal positioning, the role of NKT cells in respiratory infectious diseases remains poorly understood. Hence, we assessed their function in a murine model of pulmonary t...

Under different circumstances, natural killer T (NKT) cells can cause a T helper (Th) 1 or a Th2 polarization of immune responses. We show here, however, that mouse NKT cells with an invariant V 14 rearrangement (V 14i NKT cells) rapidly produce both IL-4 and IFN, and this pattern could not be altered by methods that polarize naive CD4 T cells. Surprisingly, although cytokine protein was detect...

Natural killer (NK) T lymphocytes are a subpopulation of T lymphocytes regarded as early regulators of immune responses. The majority of NKT cells are restricted by the CD1d molecule. NKT cells have mostly been studied in one single mouse strain, C57BL/6 (B6), because of the absence of NK1.1 in other common mouse strains, and the lack of other reliable surface markers for CD1d-restricted cells....

Gamma interferon (IFN-gamma)-regulated chemokines of the CXC family have been implicated as key regulators of a variety of T-cell-dependent inflammatory processes. However, the cellular source(s) of IFN-gamma that regulates their early expression has rarely been defined. Here, we have directly addressed this question in mice after Leishmania donovani infection. Comparison of CXCL10 mRNA accumul...