Search results for "POLYSACCHARIDE"
showing 10 items of 635 documents
Different Modes of Regulation of the Expression of Dextransucrase in
2019
Leuconostoc lactis AV1 strain isolated from a Tunisian avocado was characterized as a dextran producer. The promoter PdsrLL and the dsrLL gene encoding the DsrLL dextransucrase responsible for the dextran synthesis were transcriptionally fused to the mCherry coding gene generating the pRCR20 plasmid. Upon plasmid transfer, both AV1n and the dextran non-producing Leuconostoc mesenteroides CM70 became red due to expression of the mCherry from the PdsrLL-dsr-mrfp transcriptional fusion. Characterization of the polymers present in cultures supernatants revealed that the DsrLL encoded from pRCR20 in the recombinant bacteria was able to synthesize dextran. The production of dextran by the DsrLL i…
Interleukin 10 restores lipopolysaccharide-induced alterations in synaptic plasticity probed by repetitive magnetic stimulation
2020
Systemic inflammation is associated with alterations in complex brain functions such as learning and memory. However, diagnostic approaches to functionally assess and quantify inflammation-associated alterations in synaptic plasticity are not well-established. In previous work, we demonstrated that bacterial lipopolysaccharide (LPS)-induced systemic inflammation alters the ability of hippocampal neurons to express synaptic plasticity, i.e., the long-term potentiation (LTP) of excitatory neurotransmission. Here, we tested whether synaptic plasticity induced by repetitive magnetic stimulation (rMS), a non-invasive brain stimulation technique used in clinical practice, is affected by LPS-induc…
Screening for inhibitors of HIV gp120-CD4 binding using an enzyme-linked immunoabsorbent assay.
1993
Binding of the HIV-1 major viral surface glycoprotein, gp120, to the major cell receptor, CD4, is essential for HIV infection of the target cell and syncytium formation. An enzyme-linked immunoassay using solid phase CD4 was used to quantitate the binding of HIV-1 gp120 to CD4, and to assess the activity and mechanism of action of putative inhibitors of that reaction. Monoclonal antibodies to the gp120 binding site on CD4 (e.g., Leu3a) blocked gp120 binding, while monoclonal antibodies to other portions of CD4 (e.g. OKT4) did not. Both aurintricarboxylic acid and sulfonated polysaccharides (e.g., dextran sulfate) blocked CD4-gp120 interactions by binding to the CD4 component. Human polyclon…
Preeclampsia, a pregnancy-specific disease, is associated with fetal monocyte activation.
2001
The maternal syndrome of preeclampsia is an exclusively pregnancy-related illness involving multiple organs and severe forms may be complicated by HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome. Recently, it has been proposed that both normal pregnancy and preeclampsia are associated with a systemic activation of the nonspecific maternal immune system and that, in particular, monocytes have a central role in the adjustment of maternal immune functions in pregnancy. Here we have investigated the role of the fetal nonadaptive immune system in normal term delivery, uncontrollable preterm labor, and preeclampsia. We demonstrate that spontaneous delivery at term as well as pre…
Sequential release of TNFα and phospholipase A2 in a rat model of LPS-induced pleurisy
1997
The levels of extracellular phospholipase A2(sPLA2) and TNFα, and cell accumulation were measured in the pleural washings obtained at different times following the induction ofEscherichia colilipopolysaccharide (LPS, 100 μg/cavity) pleurisy in rats. TNFα peaked at 2 hours (3036 ± 160.3 units/ml) and decreased thereafter. Conversely, levels of sPLA2peaked at 48 hours (1.97 ± 0.64 ng/ml) and were increased further (14.02 ± 4.16 ng/ml) by pretreatment with anti-TNFα antibody. Cell accumulation was not affected by antibody pretreatment. These data indicate that the sPLA2enzyme is involved in LPS-induced pleurisy. The enzyme seems not to be stimulated by TNFα which may be involved in the downreg…
Increased Phospholipid Transfer Protein Activity Is Associated With Markers of Enhanced Lipopolysaccharide Clearance in Human During Cardiopulmonary …
2021
Introduction: Lipopolysaccharide (LPS) is a component of gram-negative bacteria, known for its ability to trigger inflammation. The main pathway of LPS clearance is the reverse lipopolysaccharide transport (RLT), with phospholipid transfer protein (PLTP) and lipoproteins playing central roles in this process in experimental animal models. To date, the relevance of this pathway has never been studied in humans. Cardiac surgery with cardiopulmonary bypass is known to favor LPS digestive translocation. Our objective was to determine whether pre-operative PLTP activity and triglyceride or cholesterol-rich lipoprotein concentrations were associated to LPS concentrations in patients undergoing ca…
Neuroendocrine Regulation Of The IL-27-Dependent Immune Response In Macrophages
2013
Abstract The central nervous system has the ability for modulating immune responses, but the molecular mechanisms of such interactions are only partly understood. Interleukin-27 (IL-27) is a heterodimeric protein and structurally related to the IL-12 family of cytokines. IL-27 is composed of the subunits EBI3 and p28. The biological functions of IL-27 have been described as either anti-inflammatory or pro-inflammatory depending on the experimental models studied. In the current study, we investigated how production of Interleukin-27 (IL-27) is regulated by neuroendocrine hormones. We focused our work on the subunit p28, since EBI3 is also present in IL-35 and therefore is not a specific com…
Intraperitoneal injection of tetracyclines protects mice from lethal endotoxemia downregulating inducible nitric oxide synthase in various organs and…
1997
We have tested whether tetracyclines (TETs) are able to protect mice from lipopolysaccharide (LPS)-induced shock, a cytokine-mediated inflammatory reaction. Mice, injected with a single dose of tetracycline base (TETb; 1.5, 10 and 20 mg/kg of body weight) or doxycycline (DOXY; 1.5 mg/kg), were significantly protected from a lethal intraperitoneal injection of LPS (500 micrograms per mouse). TETs acted in early events triggered in response to LSP; in fact, they were no longer significantly protective if injected more than 1 h after the injection of endotoxin. LPS-treated mice protected by TETs showed a significant inhibition of tumor necrosis factor alpha (TNF-alpha), interleukin-1 alpha (IL…
Guinea pig Kupffer cells can be activated in vitro to an enhanced superoxide response
1988
Summary In the preceding paper it was shown that Kupffer cells isolated by digestion of the liver and purified by centrifugal elutriation can be activated in vitro by lipopolysaccharide and muramyl dipeptide to an enhanced superoxide response upon zymosan phagocytosis. Lipopolysaccharide and muramyl dipeptide also led to a strongly increased prostaglandin E 2 release during the phagocytosis of zymosan. This activation was accompanied by an increased production of prostaglandin E 2 during the incubation with the stimuli. Prostaglandin E 2 synthesis was inhibited by the cyclooxygenase inhibitor indomethacin, reduced by dexamethasone, but only slightly decreased by the lipoxygenase inhibitor n…
0347: Beneficial cardiovascular effects of O-GlcNAc stimulation in early phase of septic shock
2016
BackgroundO-GlcNAcylation, a post-translational modification, is the end product of the hexosamine biosynthetic pathway (HBP). Recent studies showed beneficial effects of its increase in acute pathologies, such as hemorrhagic shock. We postulated that increase in total protein OGlcNAcylation at the early phase of septic shock, a systemic inflammation associated with a cardiovascular dysfunction, could improve cardiovascular function and reduce mortality.MethodsTo induce an endotoxemic shock, rats (n=6-8) received iv either lipopolysaccharide (LPS, 5mg/kg) or saline (CTRL). After 1 h, fluid resuscitation (FR,15mL/kg of colloid, iv) was associated or not with HBP substrate: glucosamine (GlcN,…