Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The binding of 125I-labeled thrombin to rat peritoneal macrophages isolated 20 h after the ip injection of thioglycollate broth or lipopolysaccharide decreased to 20% of the value found in resident macrophages due to a decrease in the number of receptors. The binding returned to normal values within a week after the injection. The decline parallelled more or less the Vmax for the 5'-nucleotidase activity. This decrease in the binding of thrombin could not be explained by an immigration of monocytes into the peritoneal cavity, since the binding of 125I-labeled alpha 2-macroglobulin-trypsin complex increased 4.5-fold in the same cell population due to an increase in the number of receptors, and blood monocytes do not bind alpha 2-macroglobulin-trypsin complex. The increase in the binding of alpha 2-macroglobulin-protease complex parallelled an increase in the incorporation of glucosamine, although the latter did not increase to the same extent. Engulfment of plasma membrane after phagocytosis did not result in a decreased binding of thrombin, but preincubation at 37 degrees C with concanavalin A caused a minor reduction in the binding. There was a positive correlation between the binding of alpha 2-macroglobulin-trypsin complex and the fraction of polymorphonuclear leukocytes in the peritoneal exudate and a negative correlation between the binding of thrombin and the fraction of polymorphonuclear leukocytes in the exudate, when the inflammation was induced by a milder stimulus, sterile NaCl, indicating a common signal for the polymorphonuclear leukocyte chemotaxis and the macrophage differentiation.
 ...
PMID:In vivo inflammatory stimulation induces a transient change in the binding of thrombin to rat peritoneal macrophages. 131 45

Strains of Porphyromonas gingivalis were serologically classified into three groups (a, b, and c) by immunodiffusion test using the autoclave extracted antigens. All tested strains had proteolytic activity, but the activity differed from strain to strain, regardless of serogroup. It was found that serogroup a strains had more collagenolytic activity than did serogroup b (p < 0.05), but that the three groups have no remarkable differences in trypsin activity. All autoclave extracted serogroup-specific antigens induced the release of interleukin-1 beta (IL-1 beta) from human peripheral monocytes. Serogroup-specific antigen of an invasive strain designated 16-1 (serogroup b) induced the highest release of IL-1 beta among all samples. The results of immunoblotting tests and IL-1 beta production indicated that there are serogroup-specific polysaccharide other than lipopolysaccharide in P. gingivalis.
 ...
PMID:The relationship between polysaccharide antigen and interleukin-1 beta producing activity in Porphyromonas gingivalis. 133 13

Phytohemagglutinin (PHA) injection induces transient protease-sensitive traffic of lymphocytes in skin and other tissues in several species. Examination of the possible roles of cytokines in such reactions showed that recombinant bovine and human tumor necrosis factor (TNF)-alpha potently induce dose-dependent lymphocyte traffic in pig skin (and in other tissues including the draining lymph nodes) with early kinetics and a morphology of the inflammatory reaction similar to that of PHA (peaking 9-12 h). Recombinant human interleukin (IL)-1 alpha also induces dose-dependent lymphocyte traffic, but it peaks at 4 h. Entry of labeled lymphocytes into inflammatory sites induced by PHA, TNF-alpha and IL-1 alpha, but not into normal skin, is inhibited by approximately 80% by their pretreatment with trypsin, indicative of the induction of endothelial determinants recognized by protease-sensitive surface molecules on the lymphocytes. Even the minimal lymphocyte traffic induced by interferon-gamma and lipopolysaccharide was similarly protease sensitive. At the earliest stage (approximately 2 h) of significant induction of lymphocyte entry by TNF-alpha and IL-1 alpha the inductive signal for each appears easily saturated. Thus lymphocyte entry is little increased by increasing low cytokine doses over 100-fold: However, these reactions are additive, and this was used to confirm that they are distinct from each other and from PHA. A further distinction was revealed by the homing of lymphocytes pretreated with pertussis toxin: such lymphocytes were greater than 90% inhibited in their homing to tissues through constitutive high endothelial venules (HEV) and greater than 60% inhibited in homing to TNF-alpha and IL-1 alpha skin sites, but unaffected in homing to PHA skin sites (like most non-HEV-mediated traffic). Moreover, potent chicken anti-TNF-alpha, which prevented TNF-induced lymphocyte entry, did not affect PHA-induced traffic. Thus, these three agents which induce peripheral lymphocyte traffic appear to involve different mechanisms as shown by differences in (i) their kinetics; (ii) the effect of anti-TNF-alpha and (iii) the effect of pertussis toxin treatment of the lymphocytes and by the fact that their inductive mechanisms are additive in effect.
 ...
PMID:Active lymphocyte traffic induced in the periphery by cytokines and phytohemagglutinin: three different mechanisms? 151 13

Human macrophages, differentiated in vitro from blood monocytes, can be induced to secrete tumouricidal activity when activated by combined treatment with recombinant interferon gamma and bacterial lipopolysaccharide. We have analysed conditioned culture supernatants of activated human monocytes and in vitro differentiated macrophages cultivated under serum-free conditions for cytolytic activity against a TNF alpha-insensitive human tumour cell line and characterized this activity with respect to its relationship to TNF alpha and reactive nitrogen intermediates. Cytolytic activity was recovered in the high molecular weight fraction of culture supernatants conditioned by terminally differentiated macrophages, whereas conditioned culture supernatants of freshly isolated blood monocytes, processed under identical conditions, were devoid of significant cytolytic activity. This activity was tumour-specific, strongly affecting the human lymphoma cell line JMP, whereas freshly isolated human peripheral blood lymphocytes were not affected to a significant extent. It was inactivated by heat or trypsin treatment, but only partially inhibited by a monoclonal antibody against recombinant human TNF alpha, which completely neutralized all of the TNF alpha activity detectable in the supernatants tested. Cytolytic activity could not be reduced further even by a 1000-fold excess of anti-TNF alpha antibody, suggesting that TNF alpha has some synergistic effect on the tumouricidal activity observed, rather than being the central effector molecule. This notion was supported by enhancement of low levels of cytolytic activity by addition of recombinant human TNF alpha at concentrations not having any direct cytotoxic effect on the tumour target cells used.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Human macrophages secrete a tumoricidal activity distinct from tumour necrosis factor-alpha and reactive nitrogen intermediates. 156 48

The binding of a 34-kDa (mol. wt.) acylpoly(1,3)galactoside (APG) extracted from a membrane proteoglycan of Klebsiella pneumoniae to human blood leucocytes was investigated. APG is made of a long poly(1,3)galactose chain, a core-like region and a lipid moiety which comprises two glucosamine residues bound to a phosphate group and two beta OH myristic acids. Fluoresceinated APG was shown to bind preferentially to monocytes and to a lesser extent to polymorphonuclear neutrophils, as determined by flow cytometry. Binding of fluoresceinated APG was inhibited by unlabelled APG; it was concentration dependent, but not saturable, with rapid kinetics. It occurred at +4 degrees C but was markedly increased at 37 degrees C. It involved trypsin-sensitive molecules on the membrane of monocytes. Neither the parent proteoglycan nor lipopolysaccharide from K. pneumoniae or Salmonella minnesota competed for APG binding. A minor non-specific binding to lymphocytes, occurring predominantly on B cells, was observed. Unlike that of lipopolysaccharide, the APG binding was not blocked by polymyxin B sulphate. Interaction between the galactose chain of APG and the galactose receptor does not account for the binding of APG to monocytes because the galactose receptor (Mac-2) is expressed at high density on activated macrophages but not on monocytes. Despite its strong binding to human blood monocytes, APG displayed a much weaker activity than K. pneumoniae membrane proteoglycan with respect to induction of monocyte cytokine synthesis. When administered as a Technetium 99 conjugate, APG was shown to label inflammatory foci in experimental animals, and its property as a marker of macrophages is currently being evaluated in clinical trials.
 ...
PMID:Binding of a bacterial acylpoly(1,3)galactoside to human blood leucocytes. 161 80

Cultured murine bone marrow-derived macrophage (BMM phi) can be induced to secrete tumoricidal activity in vitro when activated with recombinant IFN-gamma and bacterial lipopolysaccharide (LPS). We have analyzed this activity for tumor specificity, relationship to tumor necrosis factor-alpha (TNF-alpha), serine proteases, and reactive nitrogen intermediates, and partially purified this activity by high pressure liquid chromatography. Cytolytic activity was recovered in conditioned culture supernatants of serum-free cultivated BMM phi treated with a combination of IFN-gamma and LPS but was not inducible by either stimulant alone. It selectively affected tumor cells of murine as well as human origin irrespective of sensitivity towards recombinant murine TNF-alpha (r-muTNF-alpha), but did not significantly affect non-tumorigenic cells of either species. It was inactivated by 56 degrees C, trypsin, and neuraminidase treatment, but could not be inhibited by neutralizing antibodies against r-muTNF-alpha or serine protease inhibitors. Tumoricidal activity was purified approximately 10-fold by gel filtration and eluted as a major peak with a Mr of 170 kDa, containing a single predominant protein band of approximately 170 kDa on SDS-PAGE analysis, which is shown to be a disulfide linked glycoprotein heterodimer of 110 and 58 kDa subunits (gp170). Expression of this glycoprotein was strongly dependent on activation of BMM phi by a combination of IFN-gamma and LPS but was only marginally induced by either stimulant alone. Furthermore, the level of gp170 expression was quantitatively correlated with the tumoricidal activity of BMM phi culture supernatants, whereas no such correlation was found with respect to the amount of secreted TNF-alpha or reactive nitrogen intermediates. These data demonstrate that activated murine BMM phi secrete a tumoricidal activity, which is not related to TNF-alpha, serine proteases, or reactive nitrogen intermediates, but is closely associated with a 170 kDa glycoprotein composed of two subunits with Mr's of 110 and 58 kDa.
 ...
PMID:Characterization and partial purification of a high molecular weight tumoricidal activity secreted by murine bone marrow macrophages. 162 98

Neutrophils and mononuclear cells have been associated with the lower respiratory tract inflammation observed in both acute and chronic bronchitis. In order to transit into and remain within the airways, neutrophils and mononuclear cells would likely need to adhere to bronchial epithelium. To test this hypothesis, bovine bronchial epithelial cells (BBECs) were isolated and cultured on a round coverslip. After 7 to 10 days, 51Cr-labeled neutrophils and mononuclear cells were evaluated for their capacity to adhere to the BBEC monolayer. Both neutrophils and mononuclear cells readily bound to the BBEC monolayer (10.8 +/- 1.2% bound neutrophils; 40.5 +/- 2.8% bound mononuclear cells). Stimulation of the neutrophils and mononuclear cells with phorbol 12-myristate 13-acetate (PMA) increased the adherence (45.8 +/- 10.6% bound neutrophils, P less than 0.01 compared with unstimulated cells; 58.7 +/- 6.2% bound mononuclear cells, P less than 0.01 compared with unstimulated cells). Importantly, stimulating the BBEC monolayer with PMA, bacterial lipopolysaccharide, or a cigarette smoke extract for 4 to 72 h also increased the adherence of both cell types (P less than 0.01, all comparisons at 24 h). The adherence was not decreased by exposure of either the BBEC monolayer, the neutrophils, or the mononuclear cells to cycloheximide or to the anti-CD11/CD18 monoclonal antibody 60.3 (P greater than 0.05). However, exposure of the BBEC monolayer to trypsin before addition of the neutrophils significantly decreased adherence (P less than 0.05). Because neutrophils and mononuclear cells are thought to mediate cell cytotoxicity by adhering to the target cells, BBECs were labeled with 51Cr, and 51Cr release was measured as an index of cytotoxicity. There was a modest increase in 51Cr release by the addition of unstimulated neutrophils and mononuclear cells, and culturing the BBEC monolayer with PMA before the addition of the neutrophils or mononuclear cells resulted in a further modest enhancement of 51Cr release (P less than 0.05). Similar results were obtained using lactate dehydrogenase release as a measure of cytotoxicity. These results demonstrate that inflammatory cells can adhere to BBECs and may be capable of mediating cytotoxicity and adherence and cytotoxicity can be increased by stimulating BBECs.
 ...
PMID:Modulation of neutrophil and mononuclear cell adherence to bronchial epithelial cells. 162 34

Direct virus inactivation of tachyplesin I and related isopeptides, which are antimicrobial peptides isolated from the hemocytes of the horseshoe crab (Tachypleus tridentatus and Limulus polyphemus), was examined against several viruses. Vesicular stomatitis virus (VSV) was inactivated by incubation with tachyplesin I and its isopeptides. Influenza A (H1N1) virus was slightly inactivated by tachyplesin I, whereas herpes simplex virus 1 and 2, adenovirus 1, reovirus 2 and poliovirus 1 were resistant to inactivation. The inactivation of VSV by tachyplesin I depended on the concentration, the time and the temperature of incubation. Pretreatment of tachyplesin I with trypsin or lipopolysaccharide of gram-negative bacteria entirely abolished the antiviral activity. Electron microscopy of VSV treated with tachyplesin I showed naked and damaged virions. These data suggest that tachyplesin I directly inactivates the VSV by destroying its envelope subunits.
 ...
PMID:Direct virus inactivation of tachyplesin I and its isopeptides from horseshoe crab hemocytes. 166 45

1. alpha-1-Antiproteinase (also called alpha-1-antitrypsin or alpha-1-proteinase inhibitor) with a molecular mass of 60 kDa was purified to apparent homogeneity from hamster plasma. 2. It inhibited elastase, chymotrypsin and trypsin, but did not significantly affect pancreatic kallikrein, plasma kallikrein or plasmin. 3. It has the same N-terminal heptapeptide sequence as that of rat alpha-1-antiproteinase. 4. Its plasma level decreased after injection of bacterial lipopolysaccharide.
 ...
PMID:Purification, characterization, and acute phase response of plasma alpha-1-antiproteinase in the hamster, Mesacricetus auratus. 172 45

The results of this study demonstrate that the culture supernatant of lipopolysaccharide (LPS)-stimulated murine spleen cells is able to inhibit the growth of freshly isolated B lymphocytes. The inhibition is specific for B cells because the suppression of the LPS, Fc-fragment of human IgG, dextran sulfate, and anti-mu induced proliferation of B, but not the Concanavalin A response of T lymphocytes could be shown. The cells producing the inhibitor do not adhere to plastic, and are Thy-1 negative but surface Ig positive, i.e. they are B lymphocytes. The regulatory substance is heat resistant, sensitive to trypsin treatment, and has a high molecular weight of approximately 1000 kDa. Moreover, it is specifically adsorbed on, and can be eluted from, anti-mu and anti-Ig immunoaffinity columns. Thus, it seems to be an IgM antibody. Non-specific effects were excluded by the ineffectiveness of poly- and monoclonal IgM proteins. IgM-IgG complexes were also excluded. Thus, these results suggest the existence of a novel IgM antibody mediated control mechanism regulating B cell growth during polyclonal activation.
 ...
PMID:An IgM antibody is a potent immunosuppressive agent that inhibits B cell proliferation. 183 3


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>