Search results for "Lymph"
showing 10 items of 4590 documents
New therapies for sepsis: focus on the interleukin (IL)12 family member IL27
2007
Sepsis is a severe complication of abdominal infections such as peritonitis and is associated with high mortality. Unfortunately, the molecular mechanisms controlling the development of sepsis are still incompletely understood. Interestingly, the interleukin (IL) 12 family member IL27 seems to play a key role in sepsis. In a murine model of septic peritonitis induced by caecal ligation and puncture (CLP), IL27 levels were found to be strongly induced. Furthermore, mice deficient for the EBI3 subunit of IL27 were resistant to CLP-induced septic peritonitis as compared to wild-type controls. This effect could be suppressed by injection of recombinant IL27. Further studies demonstrated that IL…
Primary in vivo T cell reactivity of NZB grafts in H-2 identical allogenic hosts.
1983
By means of the Simonson GVH-assay and the popliteal lymph node (PLN) assay, the T-cell reactivity of NZB mice against H-2 identical allogenic cells was investigated in vivo and compared to that of normal mice. None of the normal mice did react, but a highly significant NZB response could be demonstrated, which did not depend on differences in Mls antigens. These in vivo results extend previous findings of a T-cell hyperreactivity of NZB mice in primary in vitro reactions. They favour the possibility that the T-cell hyperreactivity might be relevant in vivo in facilitating autoimmune responses.
Oleuropein protects against dextran sodium sulfate-induced chronic colitis in mice.
2013
The anti-inflammatory effect of oleuropein (1), the major phenolic secoiridoid in Olea europaea, was evaluated in an experimental model of chronic colitis in mice. Animals were exposed to four repeated cycles of dextran sodium sulfate in drinking water followed by a 7-day rest period. Animals receiving a standard diet supplemented with 0.25% of 1 (equivalent to 500 mg/kg/day) for 56 days exhibited a decrease of inflammatory symptoms, as reflected by improvement of disease activity index and histopathological changes. It was found that 1 decreased inflammatory cell recruitment and the release of inflammatory cytokines interleukin (IL)-1β and IL-6 with increased IL-10 levels in colon tissue. …
Mechanical Regulation of the Cytotoxic Activity of Natural Killer Cells
2020
AbstractMechanosensing has been recently explored for T cells and B cells and is believed to be part of their activation mechanism. Here, we explore the mechanosensing of the third type of lymphocytes – Natural Killer (NK) cells, by showing that they modulate their immune activity in response to changes in the stiffness of a stimulating surface. Interestingly, we found that this immune response is bell-shaped, and peaks for a stiffness of a few hundreds of kPa. This bell-shape behavior was observed only for surfaces functionalized with the activating ligand MHC class I polypeptide-related sequence A (MICA), but not for control surfaces lacking immunoactive functionalities. We found that sti…
Susceptibility to collagen-induced arthritis is modulated by TGFβ responsiveness of T cells
2004
The objective of our study was to determine the regulatory effects that endogenous transforming growth factor beta (TGFbeta) exerts on T cells in the pathogenesis of collagen-induced arthritis (CIA). CIA was induced in transgenic mice expressing a dominant negative TGFbeta type II receptor in T cells under the control of the human CD2 promoter. Clinical and histological arthritis scores were determined and experiments on disease induction and the healing phase of disease were performed. The proliferation and cytokine production of draining lymph node cells in vitro were analyzed. Transgenic mice were more susceptible to induction of CIA. The overall incidence was higher in transgenic mice t…
Alteration of DNA topoisomerase II activity during infection of H9 cells by human immunodeficiency virus type 1 in vitro: a target for potential ther…
1990
Infection of H9 cells with human immunodeficiency virus type 1 (HIV-1) was found to decrease the phosphorylation of DNA topoisomerase II during the initial phase of infection. Simultaneously, with a later overshoot of phosphorylation and the subsequent activation of DNA topoisomerase II, the production of HIV-1 started. Applying three new protein kinase C inhibitors from the class of O-alkylglycerophospholipids we demonstrated that inhibition of protein kinase C-mediated phosphorylation of DNA topoisomerase II resulted in an inhibition of HIV-1 production. Based on the differential effect of the two protein kinase C activators, phorbol ester and bryostatin, we conclude that phosphorylation …
Diacylglycerol-containing oleic acid induces increases in [Ca(2+)](i) via TRPC3/6 channels in human T-cells.
2011
Though most of the studies have focused on the effects of free fatty acids on T-cell activation, fatty acids incorporated into plasma membrane phospholipids may also affect cell signaling via diacylglycerol (DAG), generally produced by phospholipid hydrolysis. In the present study, we have synthesized a DAG-containing oleic acid and studied its implication in the modulation of calcium signaling in human Jurkat T-cells. 1-palmitoyl-2-oleoyl-sn-glycerol (POG) induced a dose-dependent increase in [Ca(2+)](i). This effect was due to the presence of oleic acid at the sn-2 position as no differences were observed between POG and 1-stearoly-2-oleoyl-sn-glycerol (SOG). However, the substitution of …
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…
Inefficient Termination of Antigen Responses in NF-ATp-Deficient Mice
1998
In order to elucidate the role of NF-ATp, one of the most prominent members of family of NF-AT transcription factors in peripheral T lymphocytes, in T cell activation and differentiation we created NF-ATp-deficient mice by gene targeting. Such NF-ATp-/- mice are born and appear to develop a normal immune system. Apart from clear-cut defects in the synthesis of mRNAs for Th2-type lymphokines, such as IL-4, IL-5, IL-10 and IL-13, in primary and secondary stimulations of spleen cells in vitro, of a distinct impaired deletion of V beta 11+/CD4+ T lymphocytes from these mice was detected after superantigen injection. Moreover, NF-ATp-/- mice older than 6 weeks show an 2-5 fold increase in number…
HLA-DR phenotypes and blood levels of T cell subsets
1984
Blood mononuclear cell and T cell subsets values were analyzed in 53 Sicilian individuals according to HLA-DR phenotypes. The results demonstrate that DR1-positive subjects show a significant increase of blood T cell subsets whereas DR3-positive subjects show a non-significant decrease of these values. These results suggest that gene(s) associated with HLA-DR could be one of the factors which affect blood levels of T cell subsets.