Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

FUT-175 is a new synthetic protease inhibitor which strongly inhibits complement-mediated hemolysis via the classical and alternative pathways. The present study was undertaken to examine the effects of FUT-175 on antibody formation and host defense in mice since the complement system participates in both immunological responses and host defense against bacterial infection. FUT-175 did not suppress the primary IgM and IgG antibody responses to sheep red blood cells, although FUT-175 was given at 10 to 100 mg/kg/day p.o. for 3 days before or after immunization. On the other hand, the primary anti-DNP IgE antibody response to DNP-conjugated ovalbumin was slightly suppressed only by post-administration of FUT-175 in a dose of 100 mg/kg/day p.o. for 5 days. However, the results of the adoptive transfer experiments indicate that FUT-175 did not affect either T cells or B cells participating in the secondary anti-DNP IgE antibody formation. FUT-175 in a dose of 10(-4)M but not at 10(-6) to 10(-5)M significantly decreased the proliferation of spleen cells caused by concanavalin A, lipopolysaccharide or the one-way mixed lymphocytes culture reaction using 1000 R-irradiated spleen cells from BDF1 mice as stimulator cells and those from C57BL/6 mice as responder cells. FUT-175 had an inhibitory rather than an enhancing effect on host defense to infection with Escherichia coli when administered at 10 to 100 mg/kg/day p.o. for 3 days before or after infection. These results strongly suggest that FUT-175 does not affect antibody formation and host defense in mice.
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PMID:[Immunopharmacological actions of 6-amidino-2-naphthyl-4-guanidinobenzoate (FUT-175). 1. Effect of FUT-175 on immune response and host defense in mice]. 661 46

Dermal responses induced by Fusobacterium necrophorum strain VPI 2891 lipopolysaccharide (LPS) were studied using mice and guinea pigs. In ddY mice, the LPS elicited inflammatory, haemorrhagic lesions and an increase in local vascular permeability 24 h postinjection. Of the mouse strains, C3H/HeJ mice were less sensitive. The LPS induced erythema and haemorrhagic responses in guinea pig skin 24 h postinoculation. These responses were dose-dependent. The intensity of dermal inflammation-inducing activity of F. necrophorum LPS was similar to that of Escherichia coli strain 055:B5 LPS, but weaker than that of Salmonella typhimurium LPS. These findings suggest that the fusobacterial LPS may play an important role in contributing to produce the initial lesions in the bacterial infection.
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PMID:Local skin reaction in mice and guinea pigs induced by a single intradermal inoculation of Fusobacterium necrophorum lipopolysaccharide. 747 58

Acute-phase proteins and heat shock proteins (hsp) are upregulated following exposure to a number of conditions including bacterial infection, tissue injury, or stress. We show here that alpha 2 macroglobulin (alpha 2M), angiotensinogen (AOG), and hsp 70 are regulated by cytokines in primary cultures of astrocytes. In addition, we have found that insulin modulates the effect of cytokines on these proteins. In cells treated with lipopolysaccharide (LPS) conditioned Raw media, interleukin (IL)-6, or IL-1 beta for 24 h, there was a significant decrease of alpha 2M secretion below control levels. In the absence of insulin, however, similar treatments resulted in a significant increase in alpha 2M secretion. AOG secretion increased significantly following treatment with individual cytokines either in the presence or absence of insulin, but conditioned media did not cause a response in the absence of insulin. Hsp 73 concentrations also increased following treatment with conditioned media and IL-1 beta in the presence or absence of insulin. Following IL-6 treatment, however, hsp levels either decreased (- insulin) or did not change (+ insulin). To determine whether acute-phase proteins are regulated similarly to hsp, astrocytes were subjected to elevated environmental temperatures. Cells incubated at 43 degrees C for 90 min showed a marked increase in AOG secretion. However, alpha 2M and hsp 73 levels remained unchanged. In the absence of insulin, heat shock caused a significant increase of alpha 2M and AOG secretion. Thus, in astrocytes, alpha 2M is upregulated by cytokines and heat shock in the absence of insulin, while in the presence of insulin, cytokines function as negative regulators.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Cytokine and insulin regulation of alpha 2 macroglobulin, angiotensinogen, and hsp 70 in primary cultured astrocytes. 753 72

Peripheral blood mononuclear cells (PBMC) from six patients with paroxysmal nocturnal haemoglobinuria (PNH) were analysed by flow cytometry for expression of CD14 and for ability to respond to bacterial lipopolysaccharide and beta 1-4 linked polymannuronic acid by TNF secretion. Expression of cell surface CD14 could not be detected on cells from the PNH patients, whereas the levels of expression of other monocyte antigens, e.g. CD33 and CD13, were comparable to that of cells from healthy subjects. The cells from the patients with PNH responded with secretion of significantly less TNF after stimulation with LPS and polymannuronic acid than mononuclear cells from healthy subjects, suggesting an impaired ability in PNH to respond to bacterial infection by TNF secretion from monocytes. Soluble CD14 appeared to be involved in the residual activation of CD14 negative PBMC, and the sera of these patients contained normal or slightly elevated levels of soluble CD14. After allogeneic bone marrow transplantation in one patient the monocytes expressed CD14 at normal levels and responded normally with respect to their ability to generate TNF upon stimulation.
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PMID:The involvement of CD14 in stimulation of TNF production from peripheral mononuclear cells isolated from PNH patients. 753 47

Tissue macrophages and their precursors-the blood monocytes-respond rapidly to a bacterial infection with the release of inflammatory mediators. These mediators are involved in the recruitment of phagocytic cells, principally neutrophils, from the blood to the site of infection. To initiate this process macrophages and monocytes must be able to detect the presence of bacteria in a reliable, but nevertheless nonspecific, fashion. It is thought that this is achieved by means of receptors on the cell surface which recognize structures common to many different bacteria. One candidate for such a "pattern recognition element" is the cell surface glycoprotein CD14. CD14 has been shown to bind components of the Gram-positive cell wall and it also binds soluble lipopolysaccharide released from Gram-negative bacteria. In both cases the interaction with CD14 leads to an activation of the cell. Here we show that human peripheral blood monocytes can, in addition, bind intact Gram-negative bacteria in the presence of serum and this process involves CD14. When CD14 expression is induced on the myelomonocytic cell line U937 by treatment with vitamin D3 the cells concomittently acquire the capacity to bind bacteria. Furthermore, a non-monocytic cell line which does not bind bacteria acquires the capacity to do so when transfected with either the human or mouse CD14 gene. This binding can be inhibited by blocking the CD14 receptor with anti-CD14 antibody or by blocking the ligand on the bacteria with soluble CD14. Finally we demonstrate binding of sCD14 to Escherichia coli. We conclude that in the presence of serum both membrane-bound and soluble forms of CD14 can bind to Gram-negative bacteria. This suggests that CD14 may play a role in the detection and elimination of intact bacteria in vivo.
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PMID:Both membrane-bound and soluble forms of CD14 bind to gram-negative bacteria. 753 60

In humans and experimental animals the presence of bacterial lipopolysaccharide (endotoxin, LPS) signals the presence of gram-negative bacteria. Recognition of LPS triggers gene induction by myeloid and nonmyeloid lineage cells. These inducible genes encode proteins that include cytokines, adhesive proteins, and enzymes that produce low molecular weight proinflammatory mediators. Together the products of these inducible genes upregulate host defense systems that participate in eliminating the bacterial infection. Unfortunately, these same mediators contribute to a serious human disease known as septic shock. Considerable progress has been made during the past decade in determining the sources, identities, and sequence of release of these mediators. In contrast, until recently, marked gaps in our knowledge existed regarding the identity of the LPS receptor and intracellular signaling pathways responsible for LPS-induced cell activation. The discovery in 1986 of a plasma protein termed LPS binding protein (LBP) led to the discovery of unanticipated mechanisms of LPS-induced cell activation. CD14 was found as a soluble serum protein or as a glycosylphosphatidylinositol (GPI)-anchored protein of myeloid lineage cells; it now occupies a key role in LPS-induced cell activation as we understand it today. Here we discuss how LBP enables LPS binding to CD14 and how complexes of LPS and soluble or GPI-anchored CD14 participate in cell activation. We also review the evidence supporting a model for a functional LPS receptor of myeloid cells, which is multimeric, comprised of GPI-anchored CD14 and a presently unidentified transmembrane protein that together bind LPS and initiate cell activation via kinase cascades.
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PMID:Receptor-dependent mechanisms of cell stimulation by bacterial endotoxin. 754 10

Endotoxin is a lipopolysaccharide contained within the cell wall of Gram-negative bacteria. This molecule initiates a host inflammatory response to Gram-negative bacterial infection. An adequate inflammatory response likely enhances host survival by mediating clearance of infection and bacterial toxins. Unfortunately, this same host response can also produce dysfunction of multiple organ systems and mortality. This article focuses on the history of our understanding of the role of endotoxin in human septic shock. These pathophysiologic connections have led to therapies directed at endotoxin. Unfortunately, antiendotoxin therapy has not achieved significantly improved outcome in humans with severe sepsis. This may represent lack of antiendotoxin efficacy in the compounds used, or a failure of the investigative approach. Interest in antiendotoxin therapies persists, while investigators express more humility in their understanding of endotoxin's role in the pathophysiology of septic shock.
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PMID:Pathogenic effects of endotoxin. 758 68

Hemolin is an insect protein which belongs to the immunoglobulin superfamily and is strongly induced upon bacterial infection. It has been isolated from two moths, Hyalophora cecropia and Manduca sexta. We have isolated and sequenced a genomic clone for hemolin in H. cecropia, in order to resolve its organization and as a basis for investigating hemolin gene regulation. According to Southern-blot analysis, hemolin is encoded by a single gene, Hemolin. It contains six exons ranging over 32-603 bp. The introns are positioned both within and between the immunoglobulin-like domains, a feature typical for cell-adhesion molecules belonging to the immunoglobulin superfamily. By an RNase protection assay, we show that the Hemolin transcript is strongly induced not only by bacteria, but also by lipopolysaccharide and phorbol 12-myristate 13-acetate. Analysis of the upstream region and introns revealed potential binding sites for the Cecropia immunoresponsive factor (CIF), which recognizes the kappa B-like consensus GGGRA YYYYY.
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PMID:Structure and expression of Hemolin, an insect member of the immunoglobulin gene superfamily. 760 Nov 54

The cascade of physiologic mechanisms in response to infection, the acute-phase response, is recognized as playing a major role in host defence. One such response is the hypoferremia that is consistently reported to occur during bacterial infection. This study aimed to determine whether the alterations in plasma iron were conditionable using the conditioned taste aversion (CTA) paradigm. The regime involved the pairing of a novel-tasting saccharin solution with bacterial endotoxin. Seven days after the initial pairing of these stimuli (the test day), the saccharin solution was represented. Animals exposed to this condition displayed a significant reduction in the level of plasma iron. Animals treated with an intraperitoneal dose of 400 micrograms/Kg lipopolysaccharide (LPS) displayed lower conditioned iron levels than rats infused with 100 micrograms/Kg LPS; however, this difference was not significant. These results showed that in addition to other acute-phase responses (fever and anorexia), plasma iron alterations are able to be manipulated through behavioral manipulations.
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PMID:Behavioral conditioning of endotoxin-induced plasma iron alterations. 761 18

Bacterial endotoxin (lipopolysaccharide [LPS]) causes severe damage to the host organism as a result of excessive release of inflammatory cytokines, including interleukin-1 (IL-1) and tumor necrosis factor alpha (TNF-alpha), from mononuclear phagocytes during gram-negative bacterial infection. We evaluated the ability of a novel synthetic lipid A analog with low endotoxicity, DT-5461, to antagonize LPS-induced IL-1 and TNF-alpha production in cells of monocyte/macrophage lineage and examined the protective effect of DT-5461 against lethal endotoxic shock in mice. The IL-1- or TNF-alpha-inducing activity of DT-5461 is 100,000 to 10,000 times less active than that of Escherichia coli LPS (EcLPS) or synthetic lipid A. DT-5461 significantly inhibited EcLPS-induced IL-1 and TNF-alpha release when murine peritoneal macrophages were incubated with DT-5461 2 h prior to EcLPS stimulation at the same concentration (1 microgram/ml). The antagonistic effect of DT-5461 on the production of IL-1 and TNF-alpha induced by EcLPS occurred in a concentration-dependent manner. DT-5461 also inhibited IL-1 and TNF-alpha induction when murine peritoneal macrophages were stimulated by LPS from Salmonella typhimurium or synthetic lipid A, as well as by EcLPS, but not by muramyl dipeptides. This indicated that DT-5461 specifically antagonized the action of LPS. DT-5461 also antagonized EcLPS-mediated activation of human peripheral blood monocytes. DT-5461 blocked the binding of fluorescein isothiocyanate-labelled LPS to murine peritoneal macrophages as well as it did the binding of EcLPS and synthetic lipid A, i.e., in a concentration-dependent fashion. Injection of DT-5461 2 h before EcLPS challenge prevented the production of serum IL-1 and TNF-alpha in D-galactosamine-treated mice. Furthermore, this treatment modality protected mice against LPS-induced lethal toxicity. This study suggests that DT-5461 possesses a potent LPS antagonistic effect and may be useful in a protective strategy against lethal endotoxemia caused by gram-negative bacterial infection.
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PMID:A novel synthetic lipid A analog with low endotoxicity, DT-5461, prevents lethal endotoxemia. 762 6


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