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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Neutrophil (PMN) infiltration is an early occurrence in the liver after exposure to hepatotoxic doses of endotoxin lipopolysaccharide (LPS). The purpose of this study was to test the hypothesis that PMNs contribute to the pathogenesis of LPS hepatotoxicity. The immunoglobulin fraction from serum of rabbits immunized with rat PMNs (anti-PMN Ig) was administered intravenously to rats 18 and 6 hours before exposure to an hepatotoxic dose of LPS (Escherichia coli 0128:B12). This protocol caused a greater than 95% reduction in circulating PMNs, which was maintained for the duration of the study. The immunoglobulin fraction from nonimmunized rabbits was used as a control (control Ig). Rats pretreated with control Ig exhibited a marked increase in the number of PMNs in the liver 1.5 hours after LPS exposure. This increase in hepatic PMNs was significantly reduced by pretreatment with anti-PMN Ig. Marked elevations in both alanine and aspartate aminotransferase activities (1086 +/- 311 and 880 +/- 183 SF units/ml, respectively) were observed in plasma from control Ig-treated rats 6 hours after intravenous administration of LPS (3.0 mg/kg). The response to LPS was greatly attenuated in animals receiving anti-PMN Ig (145 +/- 111 and 224 +/- 49 SF units/ml alanine and aspartate aminotransferase activities, respectively). Pretreatment of rats with immunoglobulins to rat lymphocytes reduced numbers of circulating lymphocytes but did not afford protection against the hepatotoxic effects of LPS. These results suggest that PMNs contribute to the pathogenesis of LPS hepatotoxicity.
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PMID:Neutrophil depletion protects against liver injury from bacterial endotoxin. 153 88

A comparative study on the endotoxic effects of lipopolysaccharide (LPS) from Veillonella parvula ATCC 10790 and from Bacteroides intermedius BMH was performed using an in vivo approach in the C57BL/6 mouse. Phenol-water extracted LPS of such anaerobes was purified by ultracentrifugation and DNase/RNase digestion, and characterized by a metachromatic assay for endotoxins and by electrophoresis on SDS-polyacrylamide gel and silver staining. Mouse LD50 for V. parvula LPS was 1.479 mg and for B. intermedius greater than 3.160 mg. Sublethal amounts of the LPS from anaerobes as well as from facultative aerobes decreased daily water intake and body weight in the mouse. Endotoxin from Salmonella typhimurium SL1102, Escherichia coli 0128:B12 and V. parvula had a strong effect on water intake and body weight, whereas Bacteroides intermedius LPS activity was very weak. The results of the present report suggest that V. parvula LPS has a toxic in vivo activity on mouse, which is comparable to LPS from classic enteric organisms and stronger than B. intermedius LPS.
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PMID:Biological effects of Veillonella parvula and Bacteroides intermedius lipopolysaccharides. 177 87

With a 2.9-mM concentration of unlabelled bovine serum albumin (BSA), the FITC-albumin transport (2 mg included) across the omental monolayer (0.48 +/- 0.16 mg/ml/30 min) was found to be significantly reduced as compared with the interstitial BSA concentration (290 microM) as it is the case, e.g., in peritonitis (0.79 +/- 0.09 mg/ml/30 min). Adding 10 micrograms lipopolysaccharide (LPS)/ml from Escherichia coli, serotype 0128:B12, we did not see any differences from the control. Cultured mesothelial cells took up double the amount of FITC-albumin (4.2 +/- 0.13 micrograms/10(5) cells/30 min) and in the presence of LPS the uptake of FITC-albumin was reduced to half the control (2.15 +/- 0.47 micrograms/10(5) cells/30 min). The results reveal the active participation of the mesothelium because high concentrations of BSA reduced exocytosis and stimulated endocytosis. Applying 10 micrograms/ml of LPS turned out to influence endocytosis and to reduce it at a high BSA concentration.
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PMID:Endotoxin effects on transmesothelial transport and intracellular uptake of albumin. 180 34

The effects of several congeners of the macrocyclic class of trichothecene mycotoxins on murine splenic cells in vitro were investigated. The mycotoxins were roritoxin B, myrotoxin B, roridins A, D and E, baccharinoids B4, B5 and B12, 16-hydroxyverrucarin A, and verrucarins A and J. Lymphocytes from CD-1 mice were cultured with each of the mycotoxins for 48 h to assess cytotoxicity. The maximum effect of various trichothecenes produced on cells occurred at concentrations ranging from 10(-6) to 10(-4) M. Mycotoxins had no effect at concentrations ranging from 10(-12) to 10(-7) M. The mitogenic stimulants concanavalin A, lipopolysaccharide, phytohemagglutinin, and pokeweed mitogen were added to splenic lymphocyte cultures along with varying concentrations of selected mycotoxins. Blastogenesis was inhibited at concentrations 2-5 orders of magnitude lower than those which produced lethality on resting lymphocytes.
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PMID:Effects of macrocyclic trichothecene congeners on the viability and mitogenesis of murine splenic lymphocytes. 229 78

Bacterial lipopolysaccharide (LPS) has previously been shown to enhance a number of chemoattractant-induced responses by human neutrophils. The possible role of elastase, a neutral protease with broad substrate specificity, in neutrophil-mediated vascular injury of a variety of diseases prompted us to examine a) whether or not LPS enhances the direct chemoattractant-induced secretion of elastase, b) the quantitative requirements of LPS and chemotactic factors, and c) some structural requirements of LPS for this effect. Our results show that LPS at 10 ng/ml and above, enhanced formyl-methionyl-leucyl-phenylalanine-induced neutrophil secretion of elastase, as well as secretion of myeloperoxidase and vitamin B12-binding protein. This effect was independent of cytochalasins or surface stimulation, and thus may occur during chemotactic factor stimulation in vivo. LPS also enhanced neutrophil secretory responses to the complement fragments C5a, C5a des arg, and, to a lesser degree, to leukotriene B4 and platelet-activating factor. This enhancement effect appeared to require the presence of the lipid A moiety and/or parts of the core polysaccharide but not the O-antigen portion of the LPS molecule. Our findings identify a possible LPS-dependent mechanism of neutrophil elastase-mediated tissue injury in Gram-negative infections.
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PMID:Bacterial lipopolysaccharide enhances chemoattractant-induced elastase secretion by human neutrophils. 245 79

This article describes the construction and establishment of a double congenic nude, beige C57BL/6 (B6 nu, bg) mouse strain. The mice do not show higher fragility than C57BL/6 nude mice and the double congenic strain can be maintained under conventional mouse housing conditions. Although the B6 nu, bg display a very low natural killer activity which cannot be enhanced by an interferon inducer (poly(I-C], they lack responsiveness to a T cell mitogen (concanavalin A); and they also show extremely low responsiveness to a B cell mitogen (0128: B12 Escherichia coli lipopolysaccharide) probably as a result of combined effects of the beige and nude genes in the C57BL/6 genetic context.
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PMID:The C57BL/6 nude, beige mouse: a model of combined T cell and NK effector cell immunodeficiency. 278 19

Macrocyclic trichothecenes are a class of mycotoxins, some of which exhibit substantial antileukemic properties. These compounds vary in their toxicity by approximately 100 fold and are suspected immunotoxins. We studied 11 of these mycotoxins: roritoxin B, myrotoxin B, roridin A, verrucarin A, 16-hydroxyverrucarin A, verrucarin J, baccharinoid B12, roridin D, roridin E, baccharinoid B4 and baccharinoid B5 for their immunotoxicity in CD-1 mice. An equitoxic dose was prepared in 1% DMSO in saline and administered i.p. at half the LD50. Organ weights, WBC, RBC, differentials of blood cell counts, blastogenesis of splenic lymphocytes in response to concanavalin A (Con A), lipopolysaccharide (LPS), phytohemagglutinin (PHA) and pokeweed mitogen (PWM), and mixed lymphocyte reaction (MLR) were studied on day 4 after administration of each mycotoxin. Organ weights showed significant differences between the controls and the baccharinoids with a decrease in spleen weight in baccharinoid B12 and an increased liver weight in B4 and B5 treated animals. Administration of myrotoxin B, roridin A, verrucarin J and roridin E had total WBC counts statistically different from controls, while mice administered myrotoxin B shoed a decrease in numbers of RBC. Differentials of WBC were unremarkable regardless of the mycotoxin. Roritoxin B and baccharinoid B5 increased Con A stimulation of splenic lymphocytes. Roridin A and baccharinoid B12 increased LPS stimulation of splenic lymphocytes while baccharinoid B5 decreased the LPS response. Stimulation of splenic lymphocytes with PHA was significantly increased by roridin A and baccharinoid B5. Stimulation of splenic lymphocytes with PWM was not altered significantly by any mycotoxin.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of macrocyclic trichothecene mycotoxins on the murine immune system. 278 85

Interleukin-1 (IL-1) and other monocyte products have several important effects on the systemic response to infection in addition to their roles in lymphocyte stimulation. The present studies were carried out to determine whether products of stimulated monocytes activated circulating neutrophils (PMN) to increase expression of receptors for C3b (CR1) and C3bi (CR3), which are necessary for optimal margination, migration, and phagocytosis. Supernatants of human mononuclear cells that had been stimulated with lipopolysaccharide (LPS) or purified protein derivative (PPD) contained both tumor necrosis factor (TNF) and IL-1 and increased CR1 and CR3 expression on isolated PMNs. Supernatants of unstimulated cultures, media alone, or LPS or PPD alone had little or no effect. Supernatant effects were detectable at 1:3,000 final dilution and appeared to have a characteristic slow time course. These supernatants also caused dose- and time-dependent secretion of PMN granular constituents, but maximal receptor expression was accompanied by secretion of less than 10% of the cells' content of lysozyme and less than 16% of the B12 binding protein. Immunoadsorption studies showed that the supernatant's activity could be removed by anti-TNF but not by anti-IL-1. Recombinant IL-1 had no effect on receptor expression, but recombinant TNF increased CR1 and CR3 expression with kinetics similar to the supernatants. These results thus indicate that TNF is the major monocyte product that increases CR1 and CR3 expression on mature blood neutrophils. This would result in increased margination and phagocytic activity and may be an important systemic effect that would help the host eradicate infection.
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PMID:Tumor necrosis factor is the major monocyte product that increases complement receptor expression on mature human neutrophils. 296 77

The influence of splenectomy on the antibody response to lipopolysaccharide (LPS: E. coli 0128:B12) was investigated in mice. Splenectomy had little effect on the primary response to the LPS. However, the level of IgG anti-LPS antibodies of splenectomized mice was significantly lower than that of sham-operated mice when the mice were immunized 1, 3, and 7 days after the operation and reimmunized 7 days after the first immunization. There was no significant difference in those immunized 30 days after the operation and reimmunized 7 days later. In mice immunized before splenectomy and reimmunized 30 days after splenectomy, the level of IgG anti-LPS antibodies was low, even in the mice splenectomized 30 days after primary immunization. Our results indicate that splenectomy impairs the antibody response to lipopolysaccharides.
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PMID:The effect of splenectomy on antibody response to lipopolysaccharide (E. coli) immunization. 312 97

Brucella abortus lipopolysaccharide was tested in a blastogenesis assay with unfractionated and nylon wool-separated peripheral blood lymphocytes of Brucella-naive cattle and cattle immunized with B. abortus. Our results indicated that in cattle the lipopolysaccharide of B. abortus is not a B-cell mitogen. In immunized animals it stimulated predominantly nylon wool-adherent cells. The lipopolysaccharide of Escherichia coli O128:B12, in contrast, induced a substantially greater proliferative response in circulating lymphocytes, predominantly those adherent to nylon wool, of the Brucella-naive cattle.
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PMID:Blastogenic response of bovine lymphocytes to Brucella abortus lipopolysaccharide. 391 81


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