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

Pseudomonas aeruginosa PAO1 produces two chemically distinct types of lipopolysaccharides (LPSs), termed A-band LPS and B-band LPS. The A-band O-side chain is electroneutral at physiological pH, while the B-band O-side chain contains numerous negatively charged sites due to the presence of uronic acid residues in the repeat unit structure. Strain PAO1 (A+ B+) and three isogenic LPS mutants (A+ B-, A- B+, and A- B-) were studied to determine the contribution of the O-side-chain portion of LPS to metal binding by the surfaces of gram-negative cells. Transmission electron microscopy with energy-dispersive X-ray spectroscopy was used to locate and analyze sites of metal deposition, while atomic absorption spectrophotometry and inductively coupled plasma-mass spectrometry were used to perform bulk quantitation of bound metal. The results indicated that cells of all of the strains caused the precipitation of gold as intracellular, elemental crystals with a d-spacing of 2.43 A. This type of precipitation has not been reported previously for gram-negative cells and suggests that in the organisms studied gold binding is not a surface-mediated event. All four strains bound similar amounts of copper (0.213 to 0.222 micromol/mg [dry weight] of cells) at the cell surface, suggesting that the major surface metal-binding sites reside in portions of the LPS which are common to all strains (perhaps the phosphoryl groups in the core-lipid A region). However, significant differences were observed in the abilities of strains dps89 (A- B+) and AK1401 (A+ B-) to bind iron and lanthanum, respectively. Strain dps89 caused the precipitation of iron (1.623 micromol/mg [dry weight] of cells) as an amorphous mineral phase (possibly iron hydroxide) on the cell surface, while strain AK1401 nucleated precipitation of lanthanum (0.229 micromol/mg [dry weight] of cells) as apiculate, surface-associated crystals. Neither iron nor lanthanum precipitates were observed on the cells of other strains, which suggests that the combination of A-band LPS and B-band LPS produced by a cell may result in a cell surface which promotes the formation of metal-rich precipitates. We therefore propose that the negatively charged sites located in the O-side chains are not directly responsible for the binding of metallic ions; however, the B-band LPS molecule as a whole may contribute to overall cell surface properties which favor the precipitation of distinct metal-rich mineral phases.
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PMID:Effect of O-side-chain-lipopolysaccharide chemistry on metal binding. 992 73

The lipopolysaccharide (LPS) of Chlamydia trachomatis L2 was isolated from tissue culture-grown elementary bodies using a modified phenol/water procedure followed by extraction with phenol/chloroform/light petroleum. From a total of 5 x 10(4) cm2 of infected monolayers, 22.3 mg of LPS were obtained. Compositional analysis indicated the presence of 3-deoxy-D-manno-oct-2-ulopyranosonic acid (Kdo), GlcN, phosphorus, and fatty acids in a molar ratio of 2.8:2:2.1:4.5. Matrix-assisted laser-desorption ionization mass spectrometry performed on the de-O-acylated LPS gave a major molecular ion peak at m/z 1781.1 corresponding to a molecule of 3 Kdo, 2 GlcN, 2 phosphates, and two 3-hydroxyeicosanoic acid residues. The structure of deacylated LPS obtained after successive treatment with hydrazine and potassium hydroxide was determined by 600 MHz NMR spectroscopy as Kdoalpha2-->8Kdoalpha2-->4Kdoalpha2-->6D-GlcpNbeta1 -->6D-GlcpNalpha 1,4'-bisphosphate. These data, together with those published recently on the acylation pattern of chlamydial lipid A (Qureshi, N., Kaltashov, I., Walker, K., Doroshenko, V., Cotter, R. J., Takayama, K, Sievert, T. R., Rice, P. A., Lin, J.-S. L., and Golenbock, D. T. (1997) J. Biol. Chem. 272, 10594-10600) allow us to present for the first time the complete structure of a major molecular species of a chlamydial LPS.
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PMID:Structural analysis of the lipopolysaccharide from Chlamydia trachomatis serotype L2. 1035 25

Immunoglobulin (Ig) E is the principal Ig involved in immediate hypersensitivities and chronic allergic diseases. The hallmark of these disorders is increased IgE production. The effect of an aqueous extract of the roots of Asiasari radix (ARAE) on an in vivo and in vitro IgE production was investigated. ARAE dose-dependently inhibited the active systemic anaphylaxis and serum IgE production induced by immunization with ovalbumin, Bordetella pertussis toxin and aluminum hydroxide gel. ARAE strongly inhibited IL-4-dependent IgE production by lipopolysaccharide- stimulated murine whole spleen cells. In the case of U266 human IgE-bearing B cells, ARAE also showed an inhibitory effect on the IgE production. These results suggest that ARAE has an anti-allergic activity by inhibition of IgE production from B cells.
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PMID:Asiasari radix inhibits immunoglobulin E production on experimental models in vitro and in vivo. 1046 75

Immunoglobulin E (IgE) is the principal immunoglobulin involved in immediate hypersensitivities and chronic allergic diseases. The effect of an aqueous extract of Poncirus trifoliata (L) Raf. (Rutaceae) fruits (PTFE) on in vivo and in vitro IgE production was investigated. PTFE dose-dependently inhibited the active systemic anaphylaxis and serum IgE production induced by immunization with ovalbumin, Bordetella pertussis toxin and aluminum hydroxide gel. PTFE strongly inhibited interleukin 4 (IL-4)-dependent IgE production by lipopolysaccharide-stimulated murine whole spleen cells. In the case of U266 human IgE-bearing B cells, PTFE also showed an inhibitory effect on the IgE production. These results suggest that PTFE has an anti-allergic activity by inhibition of IgE production from B cells.
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PMID:Inhibition of immunoglobulin E production by Poncirus trifoliata fruit extract. 1047 74

The effects of two chemically unrelated nitric oxide (NO)-releasing compounds were studied on adhesion molecule expression in and neutrophil adhesion to human umbilical vein endothelial cells. Incubation of confluent monolayers of endothelial cells with increasing concentrations of lipopolysaccharide stimulated the adhesion of polymorphonuclear leukocytes to endothelial cells. Flow cytometric analysis showed that lipopolysaccharide treatment upregulated the expression of adhesion molecules E-selectin and intercellular adhesion molecule-1 (ICAM-1) in human umbilical vein endothelial cells. A novel NO-releasing compound GEA 3175 (1,2,3, 4-oxatriazolium, -3-(3-chloro-2-methylphenyl)-5-[[(4-methylphenyl)sulfonyl]amino]-, hydroxide inner salt) inhibited lipopolysaccharide-induced adhesion being more potent than the earlier known NO donor S-nitroso-N-acetylpenicillamine. The increased E-selectin expression induced by lipopolysaccharide was significantly attenuated by the two NO donors tested whereas ICAM-1 expression remained unaltered. The present data show that NO donors inhibit E-selectin expression in and neutrophil adhesion to lipopolysaccharide-stimulated vascular endothelial cells. Thus, by inhibiting leukocyte adhesion NO donors may reduce leukocyte infiltration and leukocyte-mediated tissue injury in inflammation and ischemia-reperfusion injury.
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PMID:Inhibition by nitric oxide-releasing compounds of E-selectin expression in and neutrophil adhesion to human endothelial cells. 1077 Oct 47

The lipopolysaccaride of Chlamydophila psittaci 6BC was isolated from tissue culture-grown elementary bodies using a modified phenol/water procedure followed by extraction with phenol/chloroform/light petroleum. Compositional analyses indicated the presence of 3-deoxy-Dmanno-oct-2-ulosonic acid, GlcN, organic bound phosphate and fatty acids in a molar ratio of approximately 3. 3 : 2 : 1.8 : 4.6. Deacylated lipopolysaccharide was obtained after successive microscale treatment with hydrazine and potassium hydroxide, and was then separated by high performance anion-exchange chromatography into two major fractions, the structures of which were determined by 600 MHz NMR spectroscopy as alpha-Kdo-(2-->8)-alpha-Kdo-(2-->4)-alpha-Kdo-(2-->6)-beta-D-GlcpN -(1 -->6)-alpha-D-GlcpN 1,4'-bisphosphate and alpha-Kdo-(2-->4)-[alpha-Kdo-(2-->8)]-alpha-Kdo-(2-->4)-alpha-Kdo-(2- ->6)-beta-D-GlcpN-(1-->6)-alpha-D-GlcpN 1,4'-bisphosphate. The distribution of fatty acids in lipid A was determined by compositional analyses and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry experiments on lipid A and de-O-acylated lipid A. It was shown that the carbohydrate backbone of lipid A is replaced by a complex mixture of fatty acids, including long-chain and branched (R)-configured 3-hydroxy fatty acids, the latter being exclusively present in an amide linkage.
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PMID:Structural analysis of the lipopolysaccharide from Chlamydophila psittaci strain 6BC. 1097 82

beta-Hydroxy-beta-methyl butyrate(HMB) has been shown to counteract many of the negative effects of intensive animal production methods and results in increased growth and protection against diseases. In the present study, the effect of HMB on the immunocompetence cell activity in rainbow trout (Oncorhynchus mykiss) and carp (Cyprinus carpio) was examined. Pronephric phagocytes and lymphocytes were isolated from the fish and grown in culture medium (RPMI-1640) containing either 0, 0.1, 1, 5, 10, 25, 50 or 100 microg HMB/ml of medium. The effects of HMB on the respiratory burst activity (RBA) stimulated by phorbol myristate acetate (PMA), the potential killing activity (PKA) and lymphocyte proliferation stimulated by either concanavalin A (Con-A) or lipopolysaccharide (LPS) were examined. The addition of HMB to the culture medium increased the RBA by up to 84% (p<0.01) over that of cells grown without HMB. Similarly, the PKA of the phagocytes was also increased with HMB addition to the medium by up to 140% (p<0.01) over that of cells grown without HMB. Lymphocyte proliferation stimulated by both ConA and LPS was also increased approximately two-fold (p<0.01) when HMB was added to the culture medium at concentrations between 10 and 100 microg HMB/ml in both rainbow trout and carp. The greatest effects of HMB on RBA and PKA activities were observed at a concentration >50 microg HMB/ml while lymphocyte proliferation was maximally stimulated at 25 microg HMB/ml. In conclusion, the current study shows that HMB could potentially improve immunocompetence cell activity in fish through increased cell proliferation and functionality.
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PMID:In vitro effects of beta-hydroxy-beta-methylbutyrate (HMB) on cell-mediated immunity in fish. 1104 53

Hydroxy acid-based matrix metalloproteinase (MMP) inhibitors have been shown to inhibit tumor infiltration and growth, endotoxin shock, and acute graft-versus-host disease. Blockade of the release of soluble tumor necrosis factor-alpha (TNF-alpha) and CD95 ligand (CD95L; FasL) from cell-associated forms is reportedly involved in the mechanism of the drug effect. We investigated the effect of a MMP inhibitor, KB-R7785, on host resistance against Listeria monocytogenes infection, in which TNF-alpha is essentially required for the defense, in mice. The administration of KB-R7785 exacerbated listeriosis, while the drug prevented lethal shock induced by lipopolysaccharide and D-galactosamine. KB-R7785 inhibited soluble TNF-alpha production in spleen cell cultures stimulated by heat-killed L. monocytogenes and the drug treatment reduced serum TNF-alpha levels in infected mice, whereas the compound was ineffective on the modulation of interferon-gamma and interleukin-10 production. The effect of KB-R7785 was considered to be dependent on TNF-alpha because the drug failed to affect L. monocytogenes infection in anti-TNF-alpha monoclonal antibody-treated mice and TNF-alpha knockout mice. Anti-CD95L monoclonal antibody was also ineffective on the infection. These results suggest that induction of infectious diseases, to which TNF-alpha is critical in host resistance, should be considered in MMP inhibitor-treated hosts.
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PMID:Effect of a matrix metalloproteinase inhibitor on host resistance against Listeria monocytogenes infection. 1106 65

Splenic B lineage cells expressing recombination activation genes (RAG(+)) in mice immunized with 4-hydroxy-3-nitrophenyl-acetyl coupled to chicken gamma-globulin (NP-CGG) and the adjuvant aluminum-hydroxide (alum) have been proposed to be mature B cells that reexpress RAG after an antigen encounter in the germinal center (GC), a notion supported by findings of RAG expression in peripheral B lymphocyte populations activated in vitro. However, recent studies indicate that these cells might be immature B cells that have not yet extinguished RAG expression. Here, we employ RAG2-green fluorescent protein (GFP) fusion gene knock-in mice to show that RAG(+) B lineage cells do appear in the spleen after the administration of alum alone, and that their appearance is independent of T cell interactions via the CD40 pathway. Moreover, splenic RAG(+) B lineage cells were detectable in immunized RAG2-deficient mice adoptively transferred with bone marrow (BM) cells, but not with spleen cells from RAG(+) mice. Although splenic RAG(+) B cells express surface markers associated with GC B cells, we also find the same basic markers on progenitor/precursor BM B cells. Finally, we did not detect RAG gene expression after the in vitro stimulation of splenic RAG(-) mature B cells with mitogens (lipopolysaccharide and anti-CD40) and cytokines (interleukin [IL]-4 and IL-7). Together, our studies indicate that RAG(+) B lineage cells from BM accumulate in the spleen after immunization, and that this accumulation is not the result of an antigen-specific response.
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PMID:Antigen-independent appearance of recombination activating gene (RAG)-positive bone marrow B cells in the spleens of immunized mice. 1112 Jul 71

The lipopolysaccharide (LPS) of strain 8081-c-R2, a spontaneous R-mutant of Yersinia enterocolitica serotype O:8, was isolated using extraction with phenol/chloroform/light petroleum. Its compositional analysis indicated the presence of D-GlcN, D-Glc, L-glycero-D-manno- and D-glycero-D-manno-heptose, 3-deoxy-D-manno-oct-2-ulosonic acid (Kdo) and phosphate. From deacylated LPS obtained after successive treatment with hydrazine and potassium hydroxide, three oligosaccharides (1-3) were isolated using high-performance anion-exchange chromatography, the structures of which were determined by compositional analysis and one- and two-dimensional NMR spectroscopy as [carbohydrate structure see text] in which all sugars are pyranoses, and R and R' represent beta-D-Glc (in 1 and 2) and beta-D-GlcN (in 1 only), respectively. D-alpha-D-Hep is D-glycero-alpha-D-manno-heptose, L-alpha-D-Hep is L-glycero-alpha-D-manno-heptose, Kdo is 3-deoxy-D-manno-oct-2-ulosonic acid, and P is phosphate. The liberated lipid A was analyzed by compositional analyses and MALDI-TOF MS. Its beta-D-GlcN4P-(1-->6)-alpha-D-GlcN-1-->P backbone is mainly tetra-acylated with two amide- and one ester-linked (at O3 of the reducing GlcN) (R)-3-hydroxytetradecanoic acid residues, and one tetradecanoic acid that is attached to the 3-OH group of the amide-linked (R)-3-hydroxytetradecanoic acid of the nonreducing GlcN. Additionally, small amounts of tri- and hexa-acylated lipid A species occur.
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PMID:Isolation and structural characterization of an R-form lipopolysaccharide from Yersinia enterocolitica serotype O:8. 1116 94


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