Search results for "Lymphocyte"
showing 10 items of 2280 documents
T cell proliferation in the mixed lymphocyte culture does not necessarily result in the generation of cytotoxic T effector cells.
1975
It was tested whether T lymphocytes, when stimulated in vitro by M locus-coded lymphocyte activating determinants (LAD), are able to mediate cytotoxic effector functions. The assay for cytotoxicity included both the use of purified appropriate target cells (i.e. purified lipopolysaccharide blasts) as well as the use of phytohemagglutinin dependent cytolysis as a model for detecting cytotoxic T lymphocytes (CTL). Although strong proliferative responses were obtained in the mixed lymphocyte culture, the T cell blast generated did not display any detectable cytotoxic effector function. Thus, it is concluded that LAD, at least in the M locus-dependenet system, do have the capacity to induce T c…
Interaction of TLR2 and TLR4 ligands with the N-terminal domain of Gp96 amplifies innate and adaptive immune responses.
2006
Activation of dendritic cells by ligands for Toll-like receptors (TLR) is a crucial event in the initiation of innate and adaptive immune responses. Several classes of TLR ligands have been identified that interact with distinct members of the TLR-family. TLR4 ligands include lipopolysaccharide derived from different Gram-negative bacteria and viral proteins. Recent reports have demonstrated the TLR-mediated activation of dendritic cells by heat shock proteins (HSPs). However, doubts were raised as to what extent this effect was due to lipopolysaccharide contaminations of the HSP preparations. We re-examined this phenomenon using Gp96 or its N-terminal domain, nominally endotoxin-free (0.5 …
A new chloroquinolinyl chalcone derivative as inhibitor of inflammatory and immune response in mice and rats
2003
AbstractThe synthetic chalcone derivative 1-(2,4-dichlorophenyl)-3-(3-(6,7-dimethoxy-2-chloroquinolinyl))-2-propen-1-one (CIDQ) was evaluated for its anti-inflammatory, analgesic and immunomodulatory efficacy in-vitro and in-vivo. CIDQ concentration-dependently inhibited the production of nitric oxide (NO) (IC50 4.3 μM) and prostaglandin E2 (PGE2) (IC50 1.8 μM) in RAW 264.7 macrophages stimulated with lipopolysaccharide. Human mononuclear cell proliferation was significantly inhibited by 10 μM CIDQ. Oral administration of CIDQ (10–30 mg kg−1) in the 24-h zymosan-stimulated mouse air-pouch model produced a dose-dependent reduction of cell migration as well as NO and PGE2 levels in exudates. …
Lipoic acid lessens Th1-mediated inflammation in lipopolysaccharide-induced uveitis reducing selectively Th1 lymphocytes-related cytokines release
2013
AbstractInflammation results in the production of free radicals. We evaluated the anti-inflammatory and antioxidant capacity of lipoic acid in an experimental uveitis model upon a subcutaneous injection of endotoxin into Lewis rats. The role of oxidative stress in the endotoxin-induced uveitis model is well-known. Besides, the Th1 response classically performs a central part in the immunopathological process of experimental autoimmune uveitis. Exogenous sources of lipoic acid have been shown to exhibit antioxidant and anti-inflammatory properties. Our results show that lipoic acid treatment plays a preventive role in endotoxin-induced oxidative stress at 24 h post-administration and reduced…
Budlein A from Viguiera robusta inhibits leukocyte-endothelial cell interactions, adhesion molecule expression and inflammatory mediators release
2009
Budlein A has been reported to exert some analgesic and anti-inflammatory properties. In this study, we have evaluated its effect on LPS-induced leukocyte recruitment in vivo and the mechanisms involved in its anti-inflammatory activity. In vivo, intravital videomicroscopy was used to determine the effects of budlein A on LPS-induced leukocyte-endothelial cell interactions in the murine cremasteric microcirculation. In vitro, the effects of budlein A on LPS-induced cytokine, chemokine and nitrites release, T-cell proliferative response as well as cell adhesion molecule expression (CAM) were evaluated. In vivo, intraperitoneal administration of budlein A (2.6 mM/kg) caused a significant redu…
New insight into the inhibition of the inflammatory response to experimental delayed-type hypersensitivity reactions in mice by scropolioside A.
2006
Scropolioside A, an iridoid isolated from Scrophularia auriculata ssp. pseudoauriculata, showed anti-inflammatory properties against different experimental models of delayed-type hypersensitivity. This iridoid reduced the oedema induced by oxazolone by 79% (72 h) at 0.5 mg/ear while reducing that induced by sheep red blood cells by 47% (18 h), 45% (24 h) and 36% (48 h) at 10 mg/kg. In vivo it reduced both oedema formation and cell infiltration whereas in vitro it reduced the proliferation of activated T-lymphocytes (IC50 of 67.74 microM). Treatment with scropolioside A (100 microM) 18 and 24 h after phytohemagglutinin stimulation increased the number of cells arrested in the subG(0) phase w…
Bcl-2 is a negative regulator of interleukin-1β secretion in murine macrophages in pharmacological-induced apoptosis
2010
BACKGROUND AND PURPOSE Cucurbitacin R, a natural anti-inflammatory product, has been shown to exhibit activity against both adjuvant-induced arthritis and delayed-type hypersensitivity reactions induced by various agents. Previous studies have demonstrated that the effects of cucurbitacin R stem from its inhibition of both cytokine production and lymphocyte proliferation. EXPERIMENTAL APPROACHES Effects of cucurbitacin R were investigated on lipopolysaccharide-stimulated RAW 264.7 cells. Cell cycle evolution was analysed by flow cytometry, detection of apoptosis by DNA ladder, Bcl-2, p21, p53, Bax, cleaved caspase-1 (p10), caspase-9, and caspase-3, cleaved caspase (p17) and interleukin-1β d…
Resistance of natural killer T cell-deficient mice to systemic Shwartzman reaction.
2000
The generalized Shwartzman reaction in mice which had been primed and challenged with lipopolysaccharide (LPS) depends on interleukin (IL)-12-induced interferon (IFN)-gamma production at the priming stage. We examined the involvement in the priming mechanism of the unique population of Valpha14 natural killer T (NKT) cells because they promptly produce IFN-gamma after IL-12 stimulation. We report here that LPS- or IL-12-primed NKT cell genetically deficient mice were found to be resistant to LPS-elicited mortality. This outcome can be attributed to the reduction of IFN-gamma production, because injection of recombinant mouse IFN-gamma, but not injection of IL-12, effectively primed the NKT …
Release of IL-12 by dendritic cells activated by TLR ligation is dependent on MyD88 signaling, whereas TRIF signaling is indispensable for TLR synerg…
2010
Abstract Synergistic activation of dendritic cells by combinations of TLR ligands requires both MyD88- and TRIF-dependent signaling. Recently, it has been shown that certain combinations of TLR ligands act in synergy to induce the release of IL-12 by DCs. In this study, we sought to define the critical parameters underlying TLR synergy. Our data show that TLR ligands act synergistically if MyD88- and TRIF-dependent ligands are combined. TLR4 uses both of these adaptor molecules, thus activation via TLR4 proved to be a synergistic event on its own. TLR synergy did not affect all aspects of DC activation but enhanced primarily the release of certain cytokines, particularly IL-12, whereas the …
Regulation of T cells in asthma: implications for genetic manipulation
2004
PURPOSE OF THE REVIEW Allergic asthma is a disease characterized by airway hyperresponsiveness, inflammation and remodeling. In the past few decades it has become clear that the pathogenesis and development of this disease is controlled by cytokines released by CD4 T helper type 2 lymphocytes that develop under the influence of natural killer lymphocytes. At birth, T cell priming exhibits a T helper type 2 bias and the development of the T helper phenotype is determined in the first year of life by environmental exposure to virus or bacterial substances or environmental allergens in genetically predisposed individuals. Decreased exposure to infection in early childhood has thus been linked …