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PubMed1992

Decreased serum level of tumor necrosis factor in animals treated with lipopolysaccharide and liposomes containing phosphatidylserine.

The rise in serum level of tumor necrosis factor (TNF), produced by lipopolysaccharide, has been measured in mice and rabbits treated with phospholipid liposomes. After 3 daily ip injection (mice) or 5 daily i.v. injections (rabbits) of 30 mg/kg of a phospholipid mixture enriched in phosphatidylserine, the action of lipopolysaccharide was 80-90% reduced. The phospholipid effect is dose dependent, requires a minimum of two daily injections before the administration of lipopolysaccharide, and is still manifest 2 days after the last phospholipid dose. Among individual purified phospholipids, phosphatidylserine and phosphatidylethanolamine were effective whereas phosphatidylinositol, phosphatidylglycerol, and phosphatidylcholine did not show significant activity. The data indicate that the parenteral administration of liposomes containing the aminophospholipids phosphatidylserine, and phosphatidylethanolamine is an efficient mode to reduce the endotoxin-induced production of TNF. As suggested by liposome pharmacokinetics, this effect may be related to phospholipid accumulation in the mononuclear phagocyte system of liver and spleen.

Animals↗

PubMed2005

Serial analysis of gene expression in mice with lipopolysaccharide-induced acute lung injury.

OBJECTIVE: To monitor the systemic gene expression profile in a murine model of lipopolysaccharide-induced acute lung injury. METHODS: Acute lung injury was induced by intratracheal injection of lipopolysaccharide in 3 mice. Another 3 normal mice receiving same volume of normal saline were taken as the controls. The comprehensive gene expression profile was monitored by the recently modified long serial analysis of gene expression. RESULTS: A total of 24,670 tags representing 12,168 transcripts in the control mice and 26,378 tags representing 13,397 transcripts in the mice with lung injury were identified respectively. There were 11 transcripts increasing and 7 transcripts decreasing more than 10 folds in the lipopolysaccharide-treated mice. The most overexpressed genes in the mice with lung injury included serum amyloid A3, metallothionein 2, lipocalin 2, cyclin-dependent kinase inhibitor 1A, lactate dehydrogenase 1, melatonin receptor, S100 calcium-binding protein A9, natriuretic peptide precursor, etc. Mitogen activated protein kinase 3, serum albumin, complement component 1 inhibitor, and ATP synthase were underexpressed in the lung injury mice. CONCLUSIONS: Serial analysis of gene expression provides a molecular characteristic of acute lung injury.

Animals↗

PubMedDate not supplied

[Expression of the lipopolysaccharide receptors in the rat liver cells in inflammation and in norm].

The liver can be a primary target organ for bacterial endotoxins--lipopolysaccharides, which serve as the major triggers of anaphylotoxin's generation. Both lipopolysaccharides and anaphylotoxins induce the acute-phase reaction in the liver. The acute-phase reaction comprises a variety of systemic changes. Synthesis of several plasma proteins in the liver and glucose output from hepatocytes undergo dramatic changes during inflammation. These changes are mediated by soluble factors. Mechanism of signal transduction is reviewed in detail. Attention is payed to the differences between expression of the lipopolysaccharide receptors under normal and inflammatory conditions.

Animals↗

PubMedDate not supplied

[Effect of environmental factors on the composition of lipopolysaccharides released from the Rhodobacter capsulatus cell wall].

The goal of this study was to compare the environmental factors that determine viability of the gram-negative photosynthesizing bacteria Rhodobacter capsulatus (specifically, light and growth medium composition) and to assess the effect of these factors on the synthesis and composition of lipopolysaccharides released from the cell wall. Depletion of medium resulted in the release of lipopolysaccharides with a truncated polysaccharide fragment. It is concluded that, due to high viability of these bacteria, the main factor that induced lipopolysaccharide release from the cell wall, irrespective of culturing conditions, is cell division rather than cell death.

Cell Wall↗

PubMedDate not supplied

[Characterization of the lipopolysaccharide from Rahnella aquatilis 1-95].

The lipopolysaccharide from the freshwater bacterium Rahnella aquatilis 1-95 has been isolated and investigated for the first time. The structural components of the lipopolysaccharide molecule: lipid A, core oligosaccharide, and O-specific polysaccharide were isolated by mild acidic hydrolysis. In lipid A, 3-hydroxytetradecanoic and tetradecanoic acids were found to be the predominant fatty acids. In the core oligosaccharide, galactose, arabinose, fucose, and an unidentified component were shown to be the major monosaccharides. The O-specific polysaccharide consists of a regularly repeating trisaccharide unit with the acyl and phosphate following structure: [structure: see text] groups have been shown to be responsible for the toxic and pyrogenic properties of the lipopolysaccharide of R. aquatilis.

Animals↗

PubMed1991

In vitro regulation of human phagocyte cytochrome b heavy and light chain gene expression by bacterial lipopolysaccharide and recombinant human cytokines.

We examined the effects of bacterial lipopolysaccharide and several recombinant human cytokines (tumor necrosis factor alpha and granulocyte-, macrophage-, and granulocyte-macrophage colony-stimulating factors) on the expression of the genes for the phagocyte cytochrome b, an essential component of the superoxide-generating oxidase. In vitro treatment with lipopolysaccharide, tumor necrosis factor alpha, or macrophage- or granulocyte-macrophage colony-stimulating factors increased the levels of transcripts for the cytochrome b heavy chain (gp91phox) 9- to 22-fold and transcripts for the light chain (p22phox) 2- to 5-fold in cultured human monocyte-derived macrophages. The same agents, except for macrophage colony-stimulating factor, induced the expression of the cytochrome b heavy chain gene 2- to 12-fold and light chain gene 2- to 6-fold in human granulocytes. The expression of the cytochrome b heavy and light chain genes was coordinated in both macrophages and neutrophils with regard to stimulus specificity and dose-response pattern. The time course for induction of the two genes was parallel in both cell types for all stimuli. The macrophage response to lipopolysaccharide occurred at least in part at the transcriptional level. These results show that a variety of physiological regulators modulate the coordinated expression of the cytochrome b genes.

Blotting, Northern↗

PubMed1990

Modulation of arachidonic acid metabolism by bovine alveolar macrophages exposed to interferons and lipopolysaccharide.

Stimulation of bovine alveolar macrophages with calcium ionophore A23187 resulted in marked production of leukotriene (LT)B4 and a lesser increase in thromboxane (TX)B2, whereas opsonized zymosan (OPZ) resulted in production of TXB2 and relatively small increases in LTB4 and prostaglandin (PG)F2 alpha. Alveolar macrophages incubated with recombinant bovine interferon-gamma or lipopolysaccharide, and subsequently stimulated with A23187 or OPZ, had altered arachidonic acid metabolism, producing markedly increased amounts of TXB2 and PGF2 alpha, and slightly increased LTB4. Incubation of alveolar macrophages with lipopolysaccharide had a more profound effect on the increased amounts of TXB2 and PGF2 alpha, observed in response to stimulation with A23187 or OPZ, than did incubation with interferon-gamma. Alveolar macrophages incubated with recombinant bovine interferon-alpha 1-1 also produced slightly increased amounts of LTB4 when stimulated with A23187 or OPZ. Altered arachidonic acid metabolism by alveolar macrophages exposed to interferons and lipopolysaccharide may contribute to the development of pulmonary inflammation, such as in the early stages of bacterial pneumonia following viral infections that induce interferon production.

Animals↗

PubMed1990

Physicochemical properties of the lipopolysaccharide unit that activates B lymphocytes.

We have examined the physical state of highly purified deep rough chemotype lipopolysaccharide (ReLPS) from Escherichia coli D31m4 as an aqueous suspension and as complexes with bovine serum albumin min (BSA). The ReLPS suspension showed large ellipsoidal particles 12-38 nm wide and 40-100 nm long. The solubility of this form of ReLPS was determined by equilibrium dialysis experiments to be 3.3 x 10(-8) M at 22 degrees C and 2.8 x 10(-8) M at 37 degrees C in 150 mM Tris-KCl, pH 7.5; 3.0 x 10(-8) M at 37 degrees C in 0.75 mM Tris-KCl, pH 7.5. The BSA-ReLPS complexes were fractionated on a Sephacryl S-200 column to yield peaks I and II with apparent masses of about 240 and 70 kDa, respectively. Peak II was a BSA monomer with estimated BSA:ReLPS molar ratios of 1:1-1:7. The ReLPS suspension and the two complexes were compared as antigens in enzyme-linked immunosorbent assays using three select monoclonal antibodies to lipopolysaccharide. The results were consistent with the high state of disaggregation of the ReLPS in both peaks I and II. Since the ReLPS in these complexes were not visible by electron microscopy, they did not contain vesicles or large particles. All forms of ReLPS tested were capable of stimulating 70Z/3, a lipopolysaccharide-responsive murine pre-B cell line. However, peak II was consistently more stimulatory at very low concentrations than the other preparations. The maximally stimulatory concentration of ReLPS for 70Z/3 cells was 40 ng/ml (1.6 x 10(-8) M) for peak II and 70 ng/ml (2.8 x 10(-8) M) for the ReLPS suspension. As expected, the above concentrations were at or below the solubility of the ReLPS. These results suggested that the highly disaggregated form of ReLPS (possibly the monomer) is the active unit that stimulates the cellular response in 70Z/3 cells.

Animals↗

PubMed1990

Deacylation of structurally diverse lipopolysaccharides by human acyloxyacyl hydrolase.

Acyloxyacyl hydrolase, a leukocyte enzyme previously has been shown to catalyze the hydrolysis of secondary (acyloxyacyl-linked) fatty acyl chains from the nonreducing glucosamine of the lipid A region of rough Salmonella typhimurium lipopolysaccharide (LPS). We describe here the activity of this enzyme toward smooth S. typhimurium LPS and LPS from Escherichia coli, Pseudomonas aeruginosa, Haemophilus influenzae, Neisseria meningitidis, and Neisseria gonorrhoeae. Acyloxyacyl hydrolase released the secondary acyl chains from all of these lipopolysaccharides, regardless of the location of the acyloxyacyl linkage on the diglucosamine backbone or the structure of the acyl chains. The two acyloxyacyl linkages present in each LPS molecule apparently were hydrolyzed separately, so that free fatty acids released from the different sites accumulated at different rates. The purified enzyme also removed greater than 90% of the secondary acyl chains in each LPS, indicating that the enzyme acts not only on intact LPS but also on LPS molecules that have only one secondary acyl chain. The enzyme did not release the glucosamine-linked 3-hydroxyacyl chains. The specificity and versatility of the enzyme for cleaving acyloxyacyl linkages suggest that it may be a useful reagent for studying the structure and bioactivities of lipopolysaccharides with diverse carbohydrate and lipid A structures.

Bacteria↗

PubMed1985

[Somatic antigens of the Brucella genus. The structure of the O-specific polysaccharide chain of Brucella melitensis lipopolysaccharide].

The phenol-phase soluble antigenic lipopolysaccharide was isolated from Brucella melitensis, strain 565, by the routine phenol/water procedure followed by chromatography on Sepharose 4B. After mild acid hydrolysis and chromatography on Sephadex G-50, the lipopolysaccharide yielded a linear O-specific polysaccharide built up from 1,2-linked 4,6-dideoxy-4-formamido-alpha-D-mannopyranosyl units. The structure of the polysaccharide was deduced mainly from the nuclear magnetic resonance and methylation analyses. The phenol-soluble lipopolysaccharide, isolated from commercial vaccine strain B. abortus 19-BA, on mild hydrolysis afforded material, 13C and 1H-NMR spectra of which were identical to those of the O-specific polysaccharide from B. melitensis 565.

Antigens, Bacterial↗

PubMed1987

[Antigenic polysaccharides of bacteria of the genus Shigella. Determination of the structure of polysaccharide chains of Shigella boydii type 9 lipopolysaccharide and detection of unusually high molecular weight glycolipid].

Specific acidic polysaccharide has been isolated from the Shigella boydii type 9 antigenic lipopolysaccharide after mild hydrolysis followed by chromatography on Sephadex G-50. The polysaccharide consists of D-glucose, D-glucuronic acid, 2-acetamido-2-deoxy-D-glucose, and L-rhamnose. From the results of methylation analysis, partial acid hydrolysis and 13C NMR data the structure of the repeating unit of the polysaccharide was deduced as follows: [----4)DGlcp(alpha 1----4)DGlcAp(beta 1----3)DGlcNAcp(alpha 1----3)LRhap(alpha 1----]n. The lipopolysaccharide from Sh. boydii 9 was fractionated by gel chromatography on the Sephadex G-200 column in a buffer containing sodium deoxycholate into three fractions. PAGE-SDS of the fractions obtained, 13C NMR- and chromato-mass-spectrometry data indicated that the three fractions contained the O-specific polysaccharide as the only carbohydrate component. The substance from the most high-molecular weight fraction contained unusually long O-specific chains (60,000 dalton). In the fat acid composition this fraction differed from other lipopolysaccharides by absence of beta-hydroxymyristic acid.

Antigens, Bacterial↗

PubMed1989

[The structure of O-specific polysaccharide of Yersinia frederiksenii serotype O:16,29 lipopolysaccharide].

A branched chain octose, 3,6-dideoxy-4-C-(L-glycero-1'-hydroxyethyl)-D-xylo- hexose, was isolated from the lipopolysaccharide of Yersinia frederiksenii, serovar O: 16.29 and identified as yersiniose A from Y. pseudotuberculosis, serovar VI. Mild hydrolysis of the lipopolysaccharide with acetic acid afforded a rhamnan. Structural features of the trisaccharide repeating unit were elucidated on the basic of 13C NMR spectral data, methylation studies and periodate oxidation. Using these data as well as data on sugar composition and methylation studies of the lipopolysaccharide, the following structural pattern of the repeating unit of O-specific polysaccharide was proposed: (formula; see text)

Antigens, Bacterial↗

PubMed1989

Antiproliferative activity of gamma-interferon combined with lipopolysaccharide on murine adenocarcinoma: dependence on an L-arginine metabolism with production of nitrite and citrulline.

Growth of the murine adenocarcinoma EMT6 was moderately inhibited by up to 32 units/ml of gamma-interferon (IFN-gamma). However, EMT6 growth was blocked by as low as 2 U/ml of IFN-gamma, when added with lipopolysaccharide. In the same time, the combination IFN-gamma + lipopolysaccharide induced synergistically the production of nitrite and citrulline by EMT6 cells. Synthesis of the two products was correlated with IFN-gamma concentrations. It required exogenous L-arginine and was inhibited by a methylated L-arginine derivative, NG-monomethyl-L-arginine. Inhibition was specific since urea synthesis was not reduced by NG-monomethyl-L-arginine. The L-arginine-dependent pathway was involved in EMT6 cytostasis mediated by IFN-gamma + lipopolysaccharide because cytostasis expression required L-arginine and was inhibited by NG-monomethyl-L-arginine.

Adenocarcinoma↗

PubMed1988

[Lipopolysaccharide-specific antibodies in intestinal lavage fluid, bile and serum of mice after oral application of inactivated Escherichia coli].

The formation of antibodies against lipopolysaccharide in the mouse after daily administration of 10(10) killed Escherichia coli M17 (serotype 02:K1) was studied. An IgA response in gut is already established at the first day after an immunization period of 5 days. The kinetics of antibody formation in gut lavage fluid and bile are similar. In comparison lipopolysaccharide-specific IgG antibodies against lipopolysaccharide in serum are raised later.

Animals↗

PubMed1987

Induction of tumoricidal activity in isolated rat liver macrophages by liposomes containing recombinant rat gamma-interferon supplemented with lipopolysaccharide or muramyldipeptide.

We examined whether the macrophages in the liver, Kupffer cells, could be activated to a tumoricidal state in a similar way as has been described for other macrophage types. Kupffer cells were isolated by centrifugal elutriation of pronase-treated rat livers. Incubation with highly purified recombinant rat gamma-interferon in combination with small amounts of lipopolysaccharide or muramyldipeptide resulted in highly cytotoxic macrophages, as measured against P815 tumor cells in an 18 h 51Cr-release assay. Incubation of Kupffer cells with the stimulators entrapped within liposomes, caused phagocytosis of the liposomes and subsequent activation to tumor cytotoxicity, provided that both rat gamma-interferon and subthreshold doses of either lipopolysaccharide or muramyldipeptide were encapsulated. The minimum amount of liposomal rat gamma-interferon that induced optimal activation was 0.5 U/ml, while 6 ng/ml of liposomal lipopolysaccharide or muramyldipeptide was required. Cytotoxicity of Kupffer cells activated in this way, persisted for at least 48 h. Since liposomes in circulation are readily cleared by the liver macrophages, these findings may have therapeutic implications.

Acetylmuramyl-Alanyl-Isoglutamine↗

PubMed1986

Interferon-gamma or BCG restores the responsiveness of mouse lung macrophages to lipopolysaccharide.

While mouse peritoneal macrophages respond well to lipopolysaccharide, lung macrophages were neither activated for tumor cell cytotoxicity nor killed directly by it. The unresponsiveness of lung macrophages was ascribed to lack of expression of lipopolysaccharide-binding sites on the cell surface. It was found that in vitro treatment of lung macrophages with interferon-gamma or in vivo sensitization of them with viable BCG restored the response by expression of the lipopolysaccharide binding sites. The modes of action of interferon-gamma and BCG in expressing the binding sites on mouse lung macrophages are discussed.

Animals↗

PubMedDate not supplied

[Immunochemical characteristics of a lipopolysaccharide from Pseudomonas aurantiaca].

A lipopolysaccharide was isolated from Pseudomonas aurantiaca IMB 31 by extraction with aqueous phenol and purified by ultracentrifugation. The lipopolysaccharide was confined to the phenol phase. Fucosamine (2-amino-2,6-dideoxygalactose) (36%) and bacillosamine (2,4-diamino-3,4,6-trideoxyglucose) (23%) were identified as hypothetic components of the O-chain in the carbohydrate moiety of the macromolecule using the techniques of paper chromatography, gas-liquid chromatography and ion-exchange chromatography on an amino acid analyser. Rhamnose, glucose, galactose, glucosamine and galactosamine were detected as hypothetical components of the core in the lipopolysaccharide composition, as well as 2-keto-3-deoxyoctonic acid, heptose, alpha-alanine and phosphorus, usual components of the core in Pseudomonas. The following predominant fatty acids were identified in the composition of lipid A using the techniques of gas-liquid chromatography with standard compounds and gas-liquid mass spectrometry: 3-OH C10:0 (14.4%), C12:0 (30.5%), 2-OH C12:0 (14.9%), 3-OH C12:0 (17.4%), C16:0 (9.9%). The serological relationship between P. aurantiaca strains was studied, and their phylogenetic relationship with P. fluorescens is discussed.

Immunochemistry↗

PubMed1986

Lipopolysaccharides of flagellated and non-flagellated Proteus vulgaris strains.

Lipopolysaccharides from two strains of Proteus vulgaris were analyzed. One strain (08) was motile, giving swarming growth on solid media and the other (04)--non-flagellated, not able to swarm. Both lipopolysaccharides appeared to be heterogeneous and were separated into two fractions each. Yield, chemical composition and SDS-polyacrylamide gel electrophoresis showed differences between fractions in percentage content of 0-specific and R-core polysaccharides. Relation between ability to swarming growth of Proteus strains and heterogeneity of their lipopolysaccharides is also discussed.

Electrophoresis, Polyacrylamide Gel↗