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)

The ability of Shigella flexneri to interact with lactoferrin (Lf) was examined with a 125I-labeled protein-binding assay. The percent binding of human lactoferrin (HLf) and bovine lactoferrin (BLf) to 45 S. flexneri strains was 19 +/- 3 and 21 +/- 3 (mean +/- standard error of the mean), respectively. 125I-labeled HLf and BLf binding to strain M90T reached an equilibrium within 2 h. Unlabeled HLf and BLf displaced the 125I-HLf-bacteria interaction in a dose-dependent manner. The Lf-bacterium complex was uncoupled by KSCN or urea, but not by NaCl. The interaction was specific, and approximately 4,800 HLf binding sites (affinity constant [Ka], 690 nM) or approximately 5,700 BLf binding sites (Ka, 104 nM) per cell were estimated in strain M90T by a Scatchard plot analysis. The native cell envelope (CE) and outer membrane (OM) did not reveal Lf-binding components in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. However, after being boiled, the CE and OM preparations showed three distinct horseradish peroxidase-Lf reactive bands of about 39, 22, and 16 kDa. The 39-kDa component was also reactive to a monoclonal antibody specific for porin (PoI) proteins of members of the family Enterobacteriaceae. The Lf-binding protein pattern was similar with BLf or HLf, for Crb+ and Crb- strains. The protein-Lf complex was dissociable by KSCN or urea and was stable after treatment with NaCl. Variation (loss) in the O chain of lipopolysaccharide (LPS) markedly enhanced the Lf-binding capacity in the isogenic rough strain SFL1070-15 compared with its smooth parent strain, SFL1070. These data establish that Lf binds to specific components in the bacterial OM; the heat-modifiable, anti-PoI-reactive, and LPS-associated properties suggested that the Lf-binding proteins are porins in S. flexneri.
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PMID:Lactoferrin-binding proteins in Shigella flexneri. 131 3

Both gram-negative infection and bacterial endotoxin (lipopolysaccharide, LPS) produce a marked neutropenia and increase glucose disposal by peripheral tissues. The purpose of the present study was to determine whether leukocyte depletion before these insults would diminish the commonly observed increases in tissue glucose uptake. Rats were depleted of circulating and marginated leukocytes with cyclophosphamide (CPA). Under basal postabsorptive conditions the subcutaneous injection of live Escherichia coli into control animals enhanced whole body glucose disposal that resulted in part from a stimulation of glucose uptake by the liver, spleen, intestine, and lung. These increases in tissue glucose uptake were not associated with an increase in neutrophil number, as assessed by myeloperoxidase (MPO) activity. CPA-induced leukopenia did not alter the sepsis-induced increase in glucose uptake by these tissues and whole body glucose use remained elevated. In contrast, skin and muscle proximal to the site of infection showed an increase in both glucose uptake and MPO activity. Furthermore, leukocyte depletion attenuated the elevated glucose uptake by skin and muscle near the inflammatory focus. The intravenous injection of LPS also increased whole body glucose disposal and enhanced glucose uptake by the lung, liver, spleen, intestine, and skin in saline-treated rats. Of these tissues the lung, liver, and spleen had a corresponding increase in neutrophil number. The LPS-induced increases in tissue glucose uptake in leukopenic rats were comparable, with the exception of liver and lung. In these tissues the incremental increase in glucose uptake after LPS was reduced 40-50% in leukopenic animals.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Sepsis- and endotoxin-induced increase in organ glucose uptake in leukocyte-depleted rats. 133 18

Adherence of monocytes to extracellular matrix components is critical for their accumulation at sites of infection. To gain insight into the factors that regulate monocyte recruitment, we have studied monocyte adherence with regard to the regulatory effects of bacterial lipopolysaccharide (LPS) and the mechanisms involved; moreover, we have contrasted the phenotypes of adherent and nonadherent cells. Our results show that only a minor subpopulation of monocytes (20-25%) adhere spontaneously to fibronectin and that LPS stimulated a threefold increase in the proportion of adherent cells. Basal adherence and LPS-stimulated adherence of monocytes to fibronectin were substantially mediated by CD11/CD18 integrins. Further studies revealed that spontaneously adherent monocytes were 14-fold more actively phagocytic, released 1.6-fold more superoxide anion, and contained 20-fold more peroxidase activity than nonadherent cells, whereas LPS-adherent cells had an intermediate phenotype. These results indicate that LPS may enhance the accumulation of monocytes with an antimicrobial phenotype and thereby promote resolution of tissue infection.
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PMID:Monocyte adherence to fibronectin: role of CD11/CD18 integrins and relationship to other monocyte functions. 134 80

Thioglycollate-induced murine C57BL/6 and C3H/HeN peritoneal macrophages synthesized interferon-beta (IFN-beta) in response to exposure to glycoproteins such as horseradish peroxidase (HRP) or mannosyl or fucosyl bovine serum albumin (BSAman of BSAfuc, respectively), but not glucosylated or galactosylated BSA (BSAglu or BSAgal, respectively). These results suggest participation of the mannosyl-fucosyl receptor (MFR) in this response. IFN synthesis was augmented by culturing macrophages in L cell-conditioned medium prior to exposure to these substances. Macrophages obtained from lipopolysaccharide (LPS)-resistant C3H/HeJ mice did not produce IFN in response to HRP. Furthermore, IFN-induction by HRP was blocked by polymyxin B. In addition, exposure of macrophages to HRP or BSAman induced cytotoxicity against NIH 3T12 cells. Cytotoxicity was not inhibited by the presence of anti-IFN-alpha/beta. In contrast to IFN induction, however, macrophages activation was LPS-independent, since this activity was demonstrated in macrophages from C3H/Hej mice. The carbohydrate specificity of these responses suggests that the MFR or an another scavenger receptor may be involved in the responses to these substances, and that cytotoxicity and IFN-induction by glycoproteins follow unique pathways.
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PMID:Induction of interferon synthesis and cytotoxicity by murine peritoneal macrophages exposed to glycoprotein ligands. 136 22

After administration of bacterial lipopolysaccharide, there is an increase in the number of leucocytes which adhere to the endothelial cell surface of the hepatic vessels and pass through the endothelial layer by comparison with controls. There is also marked endothelial cell damage including intracytoplasmic oedema, increased numbers of autophagic vacuoles and dilatation of the intercellular junction in LPS-treated samples. The presence of immunocytochemical products of leukotriene (LTR) and tumour necrosis factor (TNF) was examined using in both LPS-treated and control samples. Immunoreactions of LTR which were seen in specific granules of neutrophils and monocytes attached to the endothelial cell surface may indicate the onset of endothelial cell damage. Positive immunoreactions of TNF on the endothelial cell surface, seen only in LPS-treated samples, indicate that TNF may enhance the passage of blood cells through the endothelia and also increase the endocytotic activity of the liver parenchymal cells, as revealed by the present marker experiment using horseradish peroxidase. Positive reactions of TNF in lysosomes of the endothelial cells suggest that they are able to produce TNF and transport it to the cell surface.
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PMID:The immunocytochemical localization of tumour necrosis factor and leukotriene in the rat liver after treatment with lipopolysaccharide. 141 81

Human blood mononuclear cells from normal adults were collected after density-cut centrifugation and monocytes were then isolated by removal of lymphocytes using the techniques of E-rosetting and cell adhesion. The purified monocytes were further analysed by velocity sedimentation, and two distinct subpopulations with different cell sizes were obtained. The larger monocytes were 17.0 +/- 1.8 microns in diameter with a mean sedimentation rate (SR) of 7.0 +/- 0.6 mm/hr, while the smaller monocytes were 9.5 +/- 0.8 microns in size and 4.1 +/- 0.2 mm/hr in SR. The population ratio of larger:smaller cells was approximately 2:1 (66 +/- 2.8%:34 +/- 1.6%). Both cell populations exhibited a high positive rate (> 98%) in both the non-specific esterase and the peroxidase stain. However, the larger cells had much higher phagocytic activity than the smaller ones. Furthermore, the expression of monocyte-associated antigens was also different between these two subpopulations. Thus, while most of the larger monocytes (98%) could be recognized by monoclonal antibodies MY7 and OKM1, only some (35 and 61%, respectively) of the smaller monocytes could react with those antibodies. In addition, the larger monocytes secreted a significant amount of monokines including interleukin-1 beta (IL-1 beta), tumour necrosis factor-alpha (TNF-alpha) and prostaglandin E2 (PGE2) and their production increased in proportion to the level of stimulation by bacterial lipopolysaccharide (LPS), whereas the production of monokines by the smaller monocytes remained at low levels and did not respond to LPS stimulation. These results reveal the existence of phenotypic and functional heterogeneity in human blood monocytes.
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PMID:Heterogeneity of human blood monocyte: two subpopulations with different sizes, phenotypes and functions. 142 82

The peptide antibiotic Polymyxin B (PMB) binds to bacterial endotoxin (lipopolysaccharide, LPS). We prepared covalent conjugates of PMB and horseradish peroxidase (HRP) by periodation of HRP-linked oligosaccharides followed by direct condensation with PMB. In addition we prepared monoclonal antibodies (Mabs) to PMB. The PMB-HRP conjugates and anti-PMB Mabs were used to study in ELISA the binding of PMB to LPS from Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. In addition, PMB-HRP was used to quantify lipid A in ELISA, and to stain gram-negative bacteria histochemically. For the study of PMB-LPS interaction, PMB-HRP proved to be superior to the anti-PMB Mabs. PMB-HRP conjugates are useful general probes to detect or measure lipid A and LPS of various species using very simple methods and to stain bacteria, and they may obviate the need for many specific antisera. Thus, PMB-HRP conjugates are useful probes for endotoxin research.
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PMID:Polymyxin B-horseradish peroxidase conjugates as tools in endotoxin research. 148 86

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a potent stimulator of macrophages and neutrophils and plays a role in inflammatory diseases. In this article, we report that mouse brain-derived microvascular smooth muscle cells (SM) and endothelial cells (En) in coculture with splenocytes support the colony proliferation of immature granulocyte-macrophage-like (GM) cells. Unstimulated SM and En cells release GM-CSF as shown by ELISA assay and SM expresses mRNA for GM-CSF by polymerase chain reaction (PCR). Stimulation of SM and En by a nonspecific activator (lipopolysaccharide) results in upregulation of GM-CSF production. GM colonies cannot be grown on cultured astrocytes or on extracellular matrix alone prepared from smooth muscle or endothelium. However, colonies form on the extracellular matrix and on astrocytes, either in the presence of SM- or En-conditioned medium or after the addition of recombinant GM-CSF. The GM cells are positive for nonspecific esterase, peroxidase, and MAC-1 markers but are negative for FC gamma receptors and for Thy 1.2, CD8, CD4, MHC class II, and Asialo GM1 markers. These observations emphasize the possibility for active participation of brain microvasculature SM and En in acute inflammatory reactions of the central nervous system.
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PMID:Brain microvascular smooth muscle and endothelial cells produce granulocyte macrophage colony-stimulating factor and support colony formation of granulocyte-macrophage-like cells. 149 93

Vascular injury can lead to enhanced macromolecular transport into the arterial wall. We previously demonstrated that lipopolysaccharide (LPS) -induced injury to rat aorta in vivo caused increases in intimal and medial horseradish peroxidase (HRP) accumulation. In the present study, we quantitatively interpret these LPS-induced changes in HRP transport parameters. The parameters of interest are the permeability (PL) of the luminal blood-tissue boundary (combination of endothelium and internal elastic lamina, IEL), the effective diffusivity (D), and the convective velocity (V) across the media. The parameter values that yield the best fit of the model to the data provide a basis for understanding the tissue changes. The time of peak transmural (medial) accumulation (24 h after LPS injection) correlated with increases in PL (peak, 12-48 h) and preceded the maximum increase in V (peak, 36 h). The monotonic increase in the intimal accumulation during the 5 days after the injury has a time course distinct from the transient increases in PL and from the changes in D, which implies that endothelial permeability has only limited influence on transport beyond the intima. These data implicate the IEL as a barrier to macromolecular transport in the normal aorta and demonstrate that the endothelium and IEL work in concert to determine intimal macromolecular accumulation.
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PMID:Vascular injury by endotoxin: changes in macromolecular transport parameters in rat aortas in vivo. 159 Apr 61

A method for the culturing and propagation of ovine bone marrow-derived macrophages (BMM) in vitro is described. Bone marrow cells from sterna of freshly slaughtered sheep were cultured in hydrophobic (teflon foil) bags in the presence of high serum concentrations (20% autologous serum and 20% fetal calf serum). During an 18 day culture period in the absence of added conditioned medium, and without medium change, a strong enrichment of mononuclear phagocytes was achieved. Whereas the number of macrophages increased four to fivefold during this time, granulocytes, lymphoid cells, stem cells and undifferentiated progenitor cells were reduced to less than 3% of their numbers at Day 0. This resulted in BMM populations of 94 +/- 3% purity. These cells had morphological and histochemical characteristics of differentiated macrophages, and they performed functions similar to those of non-activated, unprimed human monocyte-derived macrophages. Thus, they avidly ingested erythrocytes coated with IgG of heterologous or homologous origin. They expressed a modest level of procoagulant activity, but upon triggering with lipopolysaccharide (LPS), a marked increase in cell-associated procoagulant activity was observed. LPS triggering promoted the secretion of interleukin-1, as evidenced by measurement of murine thymocyte costimulatory activity, and transforming growth factor-beta. Using the mouse L929 cell cytotoxicity assay as an indication of tumor necrosis factor (TNF) activity, no TNF activity was detected in the same supernatants, a result possibly due to species restriction. BMM generated low levels of O2- upon triggering with phorbol 12-myristate 13-acetate (PMA). On the other hand, no O2- production was observed upon stimulation with zymosan opsonized with ovine or human serum. Using luminol-enhanced chemiluminescence (CL) as a more sensitive indicator of an oxidative burst, both PMA or zymosan were able to trigger CL, but the response was subject to partial inhibition by sodium azide, an inhibitor of myeloperoxidase. This points to non-macrophage cells contributing also to the CL response, and is consistent with the view that unprimed BMM elicit a low oxidative burst upon triggering with strong inducers of a burst. Our functional characterization now allows us to apply priming and activation protocols and to relate their effect to functional alterations.
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PMID:Generation and functional characterization of ovine bone marrow-derived macrophages. 163 66


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