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)

Conditioned medium from cultured peritoneal macrophages that have phagocytosed a myelin membrane fraction is mitogenic for cultured Schwann cells. Production of the mitogenic supernatant was time- and dose-dependent with a maximal Schwann cell-proliferative response from supernatants after 48-hr incubation of cultured macrophages with myelin-enriched fraction (200 micrograms of protein per ml). The response was specific for myelin membrane: supernatants derived from macrophages incubated with axolemma, liver microsomes, polystyrene beads, or lipopolysaccharide were not mitogenic. Lysosomal processing of the myelin membrane was necessary for the production of the mitogenic factor, which was shown to be heat labile and trypsin sensitive. There was no species specificity because myelin membranes isolated from the central and peripheral nervous systems of rat, bovine, and human were equally potent in eliciting mitogenic supernatant. However, supernatants derived from central nervous system myelin membranes were two to three times more mitogenic than those obtained from peripheral nervous system fractions of the same species. Previous observations that myelin is mitogenic for cultured Schwann cells may, in part, involve the intermediate processing of myelin by macrophages that are present in Schwann cell cultures. These results suggest that macrophages play a crucial role in Schwann cell proliferation during Wallerian degeneration.
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PMID:Macrophage-mediated myelin-related mitogenic factor for cultured Schwann cells. 342 57

A chemotactic factor for polymorphonuclear leukocytes (PMNs) was found in culture medium of epithelioid cells from rat renal glomeruli. The PMN chemoattractant was trypsin sensitive, heat-stable and eluted from a Sephadex G-50 gel filtration column as a single peak with molecular weight of about 10,000. Lipopolysaccharide stimulated, in a dose-dependent manner, the chemoattractant production by epithelioid cells. This lipopolysaccharide-mediated stimulation was suppressed by an addition of cycloheximide to the culture. These results suggest that component cells of glomeruli itself can attract PMNs by producing a chemotactic factor for PMNs.
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PMID:Production of a chemotactic factor for polymorphonuclear leukocytes by epithelioid cells from rat renal glomeruli in culture. 342 22

C3H/HeJ mice are hyporesponsive to the biologic effects of bacterial lipopolysaccharide (LPS), and their splenic B cells do not proliferate after exposure to LPS. The molecular basis of this hyporesponsiveness is unknown but it may result from defective membrane signal transduction after LPS binding. To examine this possibility, we added bioactive compounds in combination with LPS to C3H/HeJ B cell cultures in order to bypass the putative defect. The addition of PMA, monensin, or ionomycin, either alone or in combination, had no effect on C3H/HeJ B cell responses to LPS. In contrast, the addition of trypsin together with LPS resulted in a partial restoration of the proliferative response in C3H/HeJ splenic B lymphocytes. The maximal C3H/HeJ B cell response varied from 25 to 60% of the C3Heb/FeJ (LPS responder) B cell response. The trypsin-mediated enhancement of the LPS response was abrogated by pretreatment of the trypsin with the trypsin inhibitors DFP or TLCK. Pretreatment of the LPS with polymyxin B, which blocks lipid A-dependent reactions, also abrogated the trypsin effect. Because the C3H/HeJ B cell responds to all other B cell mitogens, we suggest that the defect is in an LPS-specific step and that the action of trypsin results in the restoration of the missing signal. At the present time the identity of this signal is not known, but the experiments described in this report provide a unique model to elucidate the basis of LPS hyporesponsiveness in splenic B cells from C3H/HeJ mice.
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PMID:Partial restoration of the lipopolysaccharide-induced proliferative response in splenic B cells from C3H/HeJ mice. 348 72

The mechanism of metallothionein (MT) induction by lipopolysaccharide (LPS) was studied using an in vitro system. Rat peritoneal macrophages were incubated with or without LPS, after which the incubation medium was overlaid on human hepatic (Chang) cells. MT synthesis was induced in Chang cells treated with the macrophage medium incubated with LPS. No induction was observed when LPS was added directly to the Chang cell medium or when Chang cells were treated with the macrophage medium incubated without LPS. These results suggest that induction of MT by LPS is mediated by a factor released from macrophages. The factor is different from the known primary inducers of MT, such as heavy metals, glucocorticoid hormones, interleukin 1, and interferon. The factor is heat stable, nondialyzable, and stable at pH 2. Although its activity is lost by pepsin and trichloroacetic acid, it is resistant to trypsin.
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PMID:Induction of metallothionein by a macrophage factor and the partial characterization of the factor. 349 6

We undertook a study to determine whether cytokines exist which are responsible for the activation of polymorphonuclear neutrophilic granulocytes (PMN) besides the already well-known stimuli. Lucigenin-dependent chemiluminescence was used to measure human PMN activation. Addition of supernatants from mononuclear cells stimulated with bacterial lipopolysaccharide produced a long-lasting activation of granulocytes. Induction of chemiluminescence was dose-dependent and inhibitable by superoxide dismutase. Fractionation of mononuclear cells by adherence to plastic dishes or counterflow elutriation proved that monocytes were able to generate granulocyte-activating mediators (GRAM). Production of GRAM was dependent on the dose of the stimulus and appeared to be maximal after 24 h of incubation. Addition of cycloheximide resulted in significantly decreased release of GRAM. Partial characterization of the activity showed GRAM to be heat-labile and sensitive to trypsin, indicating a protein nature of GRAM. The activity fractionated into 2 distinct peaks, one corresponding to 60 kD and another below 10 kD. The interleukin 1 activity did not appear to co-fractionate with GRAM. Evidence presented suggests that the activity corresponds to factors unlikely to have been described previously.
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PMID:Granulocyte-activating mediators (GRAM): I. Generation by lipopolysaccharide-stimulated mononuclear cells. 352 11

Intravenous (i.v.) injection of mice with lipopolysaccharide (LPS), and the proteolytic enzymes trypsin and proteinase, mobilizes pluripotent haemopoietic stem cells (CFU-s) as well as granulocyte-macrophage progenitor cells (GM-CFU) and the early progenitors of the erythroid lineage (E-BFU) from the haemopoietic tissues into the peripheral blood. We investigated the involvement of the complement (C) system in this process. It appeared that the early mobilization induced by LPS and other activators of the alternative complement pathway, such as Listeria monocytogenes (Lm) and zymosan, but not that induced by the proteolytic enzymes, was absent in C5-deficient mice. The mobilization by C activators in these mice could be restored by injection of C5-sufficient serum, suggesting a critical role for C5. The manner in which C5 was involved in the C activation-mediated stem cell mobilization was studied using a serum transfer system. C5-sufficient serum, activated in vitro by incubation with Lm and subsequently liberated from the bacteria, caused mobilization in both C5-sufficient and C5-deficient mice. C5-deficient serum was not able to do so. The resistance of the mobilizing principle to heat treatment (56 degrees C, 30 min) strongly suggests that it is identical with the C5 split product C5a, or an in vivo derivative of C5a. This conclusion was reinforced by the observation that a single injection of purified rat C5a into C5-deficient mice also induced mobilization of CFU-s.
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PMID:Complement split product C5a mediates the lipopolysaccharide-induced mobilization of CFU-s and haemopoietic progenitor cells, but not the mobilization induced by proteolytic enzymes. 353 67

Previous work from this laboratory has demonstrated the persistence of Bacteroides intermedius in the livers of mice receiving an intraperitoneal inoculum of B. intermedius and Fusobacterium necrophorum. This study was undertaken to determine whether F. necrophorum enhanced the in vitro growth of B. intermedius. Tryptose phosphate broth did not support the growth of B. intermedius alone, but the bacterium did survive in a tryptose phosphate broth culture of F. necrophorum. B. intermedius cultured in F. necrophorum-conditioned tryptose phosphate broth grew impressively, reaching maximal absorbance at 24 h after inoculation. The growth of B. intermedius in F. necrophorum-conditioned tryptose phosphate broth was proportional to the amount of conditioned medium present. The B. intermedius growth-stimulating factor was detectable in conditioned medium 8 h after inoculation with F. necrophorum and could be detected throughout the 96-h incubation period. Growth-factor-active fractions eluted from a Sephadex G-100 column did not absorb at 280 nm and were retained on the column until 4 column volumes were eluted. The growth factor was nondialyzable and stable to boiling, lyophilization, extraction with hot aqueous phenol, and trypsin digestion. The factor was inactivated by exposure to pH 2.0 in the pepsin digestion protocol. Significant amounts of hexose, methyl pentose, and 2-keto-3-deoxyoctonate were detected in pooled growth-factor-active fractions eluted from the Sephadex column. This pool was also active in the Limulus lysate endotoxin assay. These results suggest that the B. intermedius growth-stimulating factor produced by F. necrophorum is a lipopolysaccharide.
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PMID:Enhancement of Bacteroides intermedius growth by Fusobacterium necrophorum. 370 Jun 5

A mouse macrophage cytotoxic factor was purified to homogeneity from the serum-free culture supernatant of a mouse macrophage hybridoma clone, N/P-7-1, stimulated with lipopolysaccharide by gel filtration, affinity chromatography, anion-exchange chromatography, and polyacrylamide gel electrophoresis. The purified material was judged to be homogeneous as to the criteria of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and has a relative molecular mass of 17,500, as determined by SDS-PAGE, or 55,000, as determined by gel filtration on columns of both Sephacryl S-200 and TSK G3000SW. It has an isoelectric point of 5.0, and is trypsin sensitive, stable at 56 degrees C and labile at pH less than 6. The cytotoxic activity of the purified factor could not be inhibited by various sugars and lectins. The production of the factor from N/P-7-1 triggered by macrophage-activating factor for cytotoxicity, but not by mouse recombinant gamma-interferon. The factor should be synthesized after lipopolysaccharide stimulation because treatment of N/P-7-1 cells with a metabolic inhibitor, emetine or actinomycin D, prevents the production.
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PMID:Purification and characterization of a cytotoxic factor produced by a mouse macrophage hybridoma. 383 93

We have studied the effects of lipopolysaccharide (LPS) on tumoricidal activity of human monocytes freshly isolated from peripheral blood. Actinomycin D-treated WEHI-164 cells were used as targets because they are NK insensitive and are lysed rapidly by monocytes in 6-hr 51Cr-release assays. Monocytes exhibited significant spontaneous activity without endotoxin. Monocytes either pretreated for 1 hr with LPS or assayed in the presence of LPS exhibited 100- to 1000-fold increased cytolytic activity. A half-maximal response was observed with 100 pg/ml LPS. Lipid A was as effective as intact LPS but required slightly higher doses. Monophosphoryl lipid A had no effect. Supernatants of monocytes cultured 5 hr contained sufficient cytolytic activity to account for levels of cytolysis mediated by monocytes directly. Doses of LPS from 10 pg/ml to 10 micrograms/ml produced parallel increases in cell-mediated and supernatant-mediated lysis. Lymphocytes did not produce cytolytic supernatants. Cytolytic activity appeared in monocyte supernatants after 30 min and peaked after 4 to 7 hr regardless of the LPS concentration; longer incubation led to a loss of activity. Cytolytic activity was heat labile and trypsin sensitive, and was recovered from Sepharose S-200 columns in a single peak with an apparent m.w. between 25,000 and 40,000. Actinomycin D or cycloheximide treatment of monocytes before the addition of LPS inhibited cytolytic monokine production. Cytolytic monokine activity was partially neutralized by specific rabbit antisera to human tumor necrosis factor (TNF). We conclude that, although fresh human monocytes exhibit spontaneous tumoricidal activity, LPS is a potent activating agent. Its stimulatory effects depend on new transcription and translation and are mediated by enhanced secretion of a cytolytic monokine similar to TNF.
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PMID:Lipopolysaccharide (LPS) stimulates fresh human monocytes to lyse actinomycin D-treated WEHI-164 target cells via increased secretion of a monokine similar to tumor necrosis factor. 390 66

We have examined the interaction of fluorescein isothiocyanate (FITC) labeled E. coli lipopolysaccharide (LPS) with human T lymphocytes by means of cell flow cytometry, in an effort to establish the type and the conditions of this interaction. Our results indicate that the interaction of LPS with human T lymphocytes is optimal at 37 degrees C. This interaction is rapid and reaches the maximum after 5 minutes and is followed by endocytosis. Our results show that sodium azide and trypsin treatment does not affect LPS- human T cell interaction, suggesting a nonspecific lipid-lipid interaction.
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PMID:Interaction of human T lymphocytes with E. coli lipopolysaccharide (LPS). 391 30


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