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)

Chagas' disease results from the infection of the protozoan parasite Trypanosoma cruzi and affects several million people in South America. Several alterations of the immune response have been described in this disease, such as severe immunosuppression of both cellular and humoral responses and massive polyclonal stimulation with the generation of autoantibodies crossreacting with host cells and tissues. We have obtained monoclonal antibodies (mAbs) from T. cruzi-infected mice that recognized a 50/55-kD antigen (GP50/55) on the T. cruzi membrane, but not in other parasites of the family Trypanosomatidae. One of these GP50/55-specific mAbs (C10) crossreacts with a 28-kD antigen (p28) expressed on the membrane of greater than 85% of activated mouse T and B lymphocytes, after in vitro activation with concanavalin A, Salmonella typhosa lipopolysaccharide, phorbol dibutyrate ester, or antigen, and on several murine T and B lymphocyte cell lines. Human T and B lymphocytes also express upon activation with phytohemagglutinin or Staphylococcus aureus Cowan I (SAC) a similar antigen recognized by mAb C10, although in a lower proportion of cells (30-40%). Furthermore, this mAb was able to suppress mouse and human T and B cell proliferation to any of those stimuli. In addition, sera from chagasic patients and T. cruzi-infected mice, but not from control patients or littermates, contain antibodies that recognize a similar p28 antigen on B lymphocytes. Furthermore, the immunoglobulin fractions of some chagasic sera also suppress the proliferation of human T lymphocytes. These results suggest a possible pathological role of autoantibodies as an alternative mechanism for T. cruzi-associated immunosuppression.
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PMID:A Trypanosoma cruzi membrane protein shares an epitope with a lymphocyte activation antigen and induces crossreactive antibodies. 137 61

The immunoglobulin kappa light chain enhancer, kappa B, is an important cis-acting transcriptional element. kappa B binds a number of proteins including the members of the ubiquitous NF-kappa B family of transcription factors. Agarose beads coupled to a double-stranded oligonucleotide containing the kappa B motif were used to isolate a 65-kDa predominantly nuclear phosphoprotein. Southwestern blot analysis demonstrated that this phosphoprotein can bind the kappa B element directly and specifically. This kappa B-associated protein was phosphorylated in vivo and in vitro by a nuclear serine/threonine kinase(s) which, in a number of different cell lines, appeared to be stimulated in response to interleukin-1 alpha and lipopolysaccharide treatment. In the B cell lines 70Z/3 and CH12 LX2B, and the T cell line EL-4 6.1 C10 the activity of the kappa B-associated kinase(s) correlated with the binding activity of nuclear NF-kappa B displayed in a gel shift assay. In vitro, the 65-kDa protein was phosphorylated in the absence of exogenously added kinase. The 65-kDa phosphoprotein and the kinase activity remained associated following sequential anion-exchange and hydrophobic interaction chromatography. These results suggest that the kappa B-associated phosphoprotein is either autophosphorylated or is phosphorylated by a closely associated kinase(s). Stimulation of a nuclear protein kinase which is closely associated with a sequence-specific DNA may reflect a novel mechanism by which growth factors regulate gene expression.
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PMID:A serine/threonine kinase activity is closely associated with a 65-kDa phosphoprotein specifically recognized by the kappa B enhancer element. 182 60

Continuous alveolar macrophage (AM) and tumor-infiltrated (TIM) cell lines have been generated from C57B16J mice by in vitro infection with the J2 retrovirus carrying the v-raf and v-myc oncogens. Four cloned AM cell lines (AMJ2-C8, AMJ2-C10, AMJ2-C11, AMJ2-C20) and 3 cloned TIM cell lines (TIMJ2-C4, TIMJ2-C7 and TIMJ2-C15) were expanded for further characterization. Flow cytometry detected the product of the raf gene in the cytoplasm of all these cell lines. Studies on the tumoricidal properties of these AM and TIM cell lines demonstrated differences in their response to a panel of known macrophage activators. Four of these cell lines (AMJ2-C8, AMJ2-C10, TIMJ2-C7 and TIMJ2-C15) were activated following exposure to recombinant murine interferon gamma (rMuIFN-gamma) but not lipopolysaccharide (LPS) or muramyl dipeptide (MDP). AMJ2-C20 was only activated by incubation with rMuIFN-gamma plus LPS. AMJ2-C11 and TIMJ2-C4 are the cell lines that most closely resembled the response pattern of the parental AM and TIM, since they could be activated by either the combination of rMuIFN-gamma plus LPS or rMuIFN-gamma plus MDP. Constitutive expression of MHC-class-II antigens was low on AMJ2-C11 or TIMJ2-C4 but was increased following exposure to rMuIFN-gamma. Neither cell line secreted substantial amounts of IL-1 or TNF but both secreted large amounts of IL-6. Thus these cell lines could be powerful tools to study AM and TIM activation and cytotoxicity.
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PMID:Tumoricidal alveolar macrophage and tumor infiltrating macrophage cell lines. 187 73

Nuclear factor kappa B (NF-kappa B) is a ubiquitous transcription factor that affects expression of many genes, including immunoglobulin kappa (kappa), the interleukin-2 receptor alpha chain, and two genes in HIV-1. NF-kappa B can be activated by a number of stimuli, including pharmacological stimulation of protein kinase C by phorbol 12-myristate 13-acetate (PMA) and treatment in vitro with either protein kinase C or protein kinase A. This has lead to the proposal that these kinases are key enzymes in the physiological activation of NF-kappa B as well. We have used a murine B cell line, 70Z/3, and T cell line, EL-4 6.1 C10, to study the activation of NF-kappa B by two physiological activators, interleukin-1 alpha (IL-1) and lipopolysaccharide (LPS). There are four reasons to propose that these agents activate pathways that do not include protein kinase C as a major component in these cell lines. First, the protein kinase C inhibitor 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H-7) strongly inhibited PMA-induced activation of NF-kappa B in 70Z/3 cells but had no effect on NF-kappa B activated by IL-1 or LPS. Second, depletion of protein kinase C by prolonged growth of 70Z/3 in PMA abrogated the capacity of the cells to activate NF-kappa B in response to further PMA treatment. However, these same cells activated NF-kappa B normally after either IL-1 or LPS treatment. Third, IL-1 effectively activated NF-kappa B in EL-4 6.1 C10 cells, but PMA did not. Fourth, interferon-gamma is a potent activator of protein kinase C in 70Z/3 cells, but is completely inactive in the mobilization of NF-kappa B. These results suggest that the physiological inducers IL-1 and LPS activate NF-kappa B by pathways independent of protein kinase C in both 70Z/3 and EL-4 6.1 C10 cells.
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PMID:Evidence that interleukin-1 and phorbol esters activate NF-kappa B by different pathways: role of protein kinase C. 205 61

Inhibition of lipopolysaccharide (LPS) synthesis in Pseudomonas aeruginosa at the stage of incorporation of 3-deoxy-D-manno-octulosonate (KDO) caused accumulation of a lipid A precursor which contained all of the fatty acids present on the lipid A of mature LPS. The enzyme CTP:CMP-3-deoxy-D-manno-octulosonate cytidylyltransferase (CMP-KDO synthetase) from P. aeruginosa is inhibited by the KDO analog alpha-C-[1,5-anhydro-8-amino-2,7,8-trideoxy-D-manno-octopyranosyl] carboxylate (I), and I is effectively delivered to P. aeruginosa following attachment by amide linkage to the carboxyl terminus of alanylalanine. Intracellular hydrolysis releases the free inhibitor (I) which then inhibits activation of KDO by CMP-KDO synthetase causing accumulation of lipid A precursor and subsequent growth stasis. The major lipid A precursor species accumulated was purified and found to contain glucosamine, phosphate, C12:O, 2OH-C12:O and 3OH-C10:0 (in ester linkage), and 3OH-C12:0 (in amide linkage) in molar ratios of 1:1:0.5:0.5:1:1. Analysis of precursor by fast atom bombardment mass spectroscopy yielded a major ion (M - H)- of mass 1616 and fragments which were consistent with the structure of lipid A from P. aeruginosa. In contrast, Salmonella typhimurium, Escherichia coli, Citrobacter sp., Serratia marcescens, Enterobacter aerogenes, and Enterobacter cloacae all accumulated underacylated lipid A precursors which only contained 3-OH-C14:0, glucosamine, and phosphate. This difference and species-specific patterns of major and minor precursor species show that early steps in the assembly of lipid A are similar, but not identical in enteric and nonenteric Gram-negative bacteria.
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PMID:Lipid A precursor from Pseudomonas aeruginosa is completely acylated prior to addition of 3-deoxy-D-manno-octulosonate. 283 99

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.
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PMID:[Immunochemical characteristics of a lipopolysaccharide from Pseudomonas aurantiaca]. 324 96

The aqueous layer was isolated from Leptospira interrogans serovar canicola strain Moulton by the hot phenol-water method. After ultracentrifugation, the precipitate was designated as lipopolysaccharide-like substance (LLS) fraction and the chemical composition was compared with that of bacterial LPS. The LLS fraction consists of 35.2% carbohydrate, 3.8% amino sugar, 36.4% lipid, 15.2% protein, and 0.3% phosphorus. Neutral sugars were detected as rhamnose, arabinose, xylose, 4-O-methylmannose, mannose, galactose, and a small amount of erythrose, fucose and glucose by gas-liquid chromatography (GLC), but 2-keto-3-deoxyoctonic acid was not detected in the LLS by thiobarbituric acid test and high voltage paper electrophoresis. Fatty acids detected by GLC were decanoic acid (C10: 0), dodecanoic acid (C12: 0), dodecenoic acid (C12: 1), tridecenoic acid (C13: 1), tetradecanoic acid (C14: 0), hexadecanoic acid (C16: 0), hexadecenoic acid (C16: 1), and octadecenoic acid (C18: 1). With SDS-polyacrylamide gel electrophoresis, bacterial LPS showed many orderly bands, while the banding pattern of the leptospiral LLS was very simple. These findings demonstrate that the physicochemical properties and chemical composition of LLS fraction from Leptospira are different from those of LPS extracted from gram-negative bacteria such as Enterobacteriaceae, and suggesting that Leptospira has no typical LPS.
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PMID:Chemical properties of lipopolysaccharide-like substance (LLS) extracted from Leptospira interrogans serovar canicola strain Moulton. 368 16

Culture supernatant fluids from the human T-cell leukemia virus-positive cell line C10/MJ-2 were found to contain a soluble factor with macrophage-activating factor (MAF) activity. The MAF activity of this culture supernatant fluid was stable at 100 degrees for 2 min and was unaffected by treatment with human anti-gamma-interferon (IFN-gamma) monoclonal antibody. Both treatments neutralized greater than 97% IFN-gamma activity from the supernatant fluid as measured by virus neutralization. Furthermore, this MAF activity was not due to contamination with endotoxins since the Limulus amebocyte lysate assay was negative (less than 0.125 ng/ml) and preincubation of the C10/MJ-2 supernatant fluid with polymyxin B did not diminish its activating potential. By contrast, human IFN-gamma rendered human monocytes tumoricidal only when combined with Salmonella typhosa lipopolysaccharide (LPS) at a minimum dose of 0.2 ng/ml. The concentrations of both LPS and IFN-gamma were crucial to achieve activation since IFN-gamma at doses less than 10 units/ml did not activate human monocytes even when combined with maximal doses of LPS (0.5 ng/ml). Finally, when human IFN-gamma admixed with LPS was preincubated with polymyxin B, its activating potential was completely abrogated. Collectively, these data suggest that the human T-cell line C10/MJ-2 constitutively produces a diffusable product distinct from IFN-gamma which activates human monocytes to lyse tumor cells. Thus, this cell line could provide a good source of a unique human MAF for future purification procedures.
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PMID:Constitutive production and release of a lymphokine with macrophage-activating factor activity distinct from gamma-interferon by a human T-cell leukemia virus-positive cell line. 608 39

The lipopolysaccharides of Rhodopseudomonas capsulata strains St. Louis (ATCC 23782) and Sp 11 both contain L-acofriose, rhamnose, glucose and glucosamine as the main sugar constituents. 2-Keto-3-deoxyoctonate and neuraminic acid were tentatively identified. The fatty acid spectrum found with both strains comprises 3-OH-C10 and C12:1 (ester-linked) and 3-oxo-C14 (amide-linked). Isolated lipid A from strain Sp 11 contains glucosamine, glucosamine-phosphate and the total of the fatty acids of the lipopolysaccharide. Methylation analysis of the degraded polysaccharide of this lipopolysaccharide shows L-acofriose in both terminal and 1 leads to 2 chain-linked positions in a 1:4 molar ratio. Rhamnose is exclusively chain-linked (1 leads to 2), glucose is both terminally and chain-linked (1 leads to 6) in a 1:1 molar ratio. The serological activity of the lipopolysaccharide of both the R. capsulata strains is low in antisera against living or heat-killed cells when tested by passive hemagglutination, Ouchterlony immunoprecipitation or gel-immunoelectrophoresis. No crossreaction was observed among the lipopolysaccharides of R. capsulata strains St. Louis, Sp 11 and 37b4 in immunoprecipitation. Lipopolysaccharide of strain Sp 11 was found to lack lethal toxicity in galactosamine-sensitized mice.
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PMID:Lipopolysaccharides of two strains of the phototrophic bacterium Rhodopseudomonas capsulata. 661 26

Sucrose density gradient centrifugation of cell envelopes of chemotrophically grown cells of Rhodopseudomonas capsulata St. Louis (= ATCC 23782) resulted in the separation of a cytoplasmic membrane from a cell wall fraction (buoyant densities, 1.139 and 1.215 g/cm3, respectively). The cell wall fractions (untreated or Triton extracted) contained peptidoglycan- and lipopolysaccharide-specific components. Their neutral sugar content, mainly rhamnose and galactose, was high (250 and 100 micrograms/mg [dry weight] of material) due to a non-lipopolysaccharide polymer. The fatty acid content was low (less than or equal to 60 micrograms/mg [dry weight] of material), and half of it was contributed by lipopolysaccharide (3-OH-C10:0, C12:1, and 3-oxo-C14:0). The predominant other fatty acid was C18:1. An outer membrane fraction, obtained by lysozyme treatment of the Triton-extracted cell wall, showed essentially the same chemical composition except for almost complete removal of peptidoglycan. Saline extraction (0.9% NaCl, 37 degrees C, 2 h) removed a lipopolysaccharide-protein(-phospholipid?) complex from whole cells of R. capsulata St. Louis. The polypeptide patterns of the cell wall and outer membrane as revealed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis comprised 20 to 25 different polypeptides (most of them very faint) and were dominated by a single, heat-modifiable major protein (Mr 69,000 after solubilization below 60 degrees C; Mr 33,000 at temperatures above 70 degrees C).
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PMID:Characterization of the cell wall and outer membrane of Rhodopseudomonas capsulata. 673 79


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