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)

Surface adhesion molecules present on human leukocytes are known to regulate certain adhesion-related events, such as adhesion to endothelium, extravasation, and aggregation. We have used a mouse anti-human monoclonal antibody designated 60.3 (MAb 60.3) and indirect immunofluorescence technique to identify an antigen on bovine neutrophils (PMNs). MAb 60.3 bound to resting and stimulated bovine PMN in a surface-oriented pattern. Immunofluorescence flow cytometric analysis indicated that warming the PMNs from 4 degrees C to 37 degrees C slightly increased (13.9%) expression of the antigen recognized by MAb 60.3. Zymosan-activated serum (ZAS, 10%) increased antigen expression by 12.4% over those PMNs in buffer alone, and phorbol 12-myristate 13-acetate (PMA; 100 ng/ml) by 65.6%. Bacterial lipopolysaccharide (LPS; 1 micrograms/ml) from E. coli 0111:B4 did not enhance antigen expression. The functional nature of this antigen was demonstrated by use of MAb 60.3 and PMN aggregation. Preincubation of bovine PMN with MAb 60.3 for 10 min resulted in nearly complete inhibition of PMN-PMN aggregation upon subsequent stimulation with PMA (100 ng/ml); preincubation with a control antibody did not inhibit aggregation. These results indicate that bovine PMNs possess surface molecule(s) that may function in adhesion-related events, and surface expression may be enhanced by PMN stimulation.
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PMID:A monoclonal-antibody-defined adhesion-related antigen on bovine neutrophils is required for neutrophil aggregation. 224 85

We have localized several major extracellular matrix protein receptors in the specific granules of human polymorphonuclear (PMN) and monocytic leukocytes using double label immunoelectron microscopy (IEM) with ultrathin frozen sections and colloidal-gold conjugates. Rabbit antibodies to 67-kD human laminin receptor (LNR) were located on the inner surface of the specific granule membrane and within its internal matrix. LNR antigens co-distributed with lactoferrin, a marker of specific granules, but did not co-localize with elastase in azurophilic granules of PMNs. Further, CD11b/CD18 (leukocyte receptor for C3bi, fibrinogen, endothelial cells, and endotoxin), mammalian fibronectin receptor (FNR), and vitronectin receptor (VNR) antigens were also co-localized with LNR in PMN specific granules. A similar type of granule was found in monocytes which stained for LNR, FNR, VNR, CD18, and lysozyme. Activation of PMNs with either PMA, f-met-leu-phe (fMLP), tumor necrosis factor (TNF), or monocytic leukocytes with lipopolysaccharide (LPS), induced fusion of specific granules with the cell membrane and expression of both LNR and CD18 antigens on the outer cell surface. Further, stimulation led to augmented PMN adhesion on LN substrata, and six- to eightfold increases in specific binding of soluble LN that was inhibited by LNR antibody. These results indicate that four types of extracellular matrix receptors are located in leukocyte specific granules, and suggest that up-regulation of these receptors during inflammation may mediate leukocyte adhesion and extravasation. We have thus termed leukocyte specific granules adhesomes.
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PMID:Adhesomes: specific granules containing receptors for laminin, C3bi/fibrinogen, fibronectin, and vitronectin in human polymorphonuclear leukocytes and monocytes. 248 Mar 53

Cells were sorted onto nitrocellulose filters which were saturated with a lysing cocktail designed to preferentially immobilize cellular mRNA. After washing, these filters were incubated with 32P-labeled specific DNA probes. We used the phorbol ester/lipopolysaccharide (PMA + LPS) co-induction of IL-1 mRNA and CD13 expression in U937 cells to demonstrate the specificity of the technique. In addition we used the abundant expression of c-fos in U937 to demonstrate linearity. IL-1 beta mRNA is readily discernable autoradiographically from as few as 5,000 PMA + LPS-induced cells sorted onto a filter. With liquid scintillation counting we demonstrate good linearity of the c-fos quantitation over the range of 1,000 cells to 60,000 cells per filter target. The technique is easily adapted to any sorting flow cytometer and should prove useful to help correlate any flow cytometric cell phenotype with specific mRNA abundance.
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PMID:Detection of mRNA in flow-sorted cells. 249 56

A number of mitogens was used in 21 chronic B-lymphocytic leukaemia patients. Thymidine uptake assays were performed to evaluate cell stimulation. Phytohemagglutinin and phorbol-myristate 13 acetate were found to be the most efficient on cell proliferation. Abnormal clones were found 7 times with PMA, 4 times with PHA, twice with pokeweed, but in no case with lipopolysaccharide or proteine-A. The efficiency of PHA as a B-cell activator is likely to be due to T cell mediation.
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PMID:Use of various mitogens and cell stimulation index in 21 patients with chronic lymphocytic leukaemia. 281 75

Sulfatide from the outer surface of Mycobacterium tuberculosis blocked priming in cultured human monocytes. Monocytes were primed in vitro with either lipopolysaccharide (LPS) or interferon-gamma. Primed monocytes released increased amounts of superoxide anion (O2-) when stimulated with formyl-methionyl-leucyl-phenylalanine or with phorbol myristate acetate. Primed monocytes also showed increased phagocytosis of sheep erythrocytes and increased release of interleukin 1. When primed monocytes were treated with 10 micrograms/ml of sulfatide, these enhanced functions, characteristic of primed monocytes, returned to levels found in unprimed monocytes. (With respect to these functions and others, monocytes or macrophages primed in vitro by exposure to LPS or interferon-gamma resemble macrophages activated in vivo by infection. In vivo, activated macrophages provide non-specific resistance to infection). Inhibition of priming by sulfatide could be detected within 10 min, but maximum effect of sulfatide required 3 to 5 hr. Sulfatide had no effect on O2- release, if it was added after the cells had been stimulated by PMA, suggesting that sulfatide did not inhibit enzymes involved in formation of O2-, but rather that sulfatide inhibited priming. Increasing the amounts of LPS or interferon-gamma did not counteract the effects of sulfatide. Sulfatide did cause monocytes to release some prostaglandin E2 (less than 1 nM), but the amount was not sufficient to inhibit monocyte functions. The effect of sulfatide was not blocked by indomethacin. Other sulfated compounds and other products of mycobacteria did not produce the sulfatide effect. We conclude that M. tuberculosis has on its outer surface a chemical that directly interferes with monocyte priming. In vivo, M. tuberculosis might use sulfatide to block macrophage activation and thereby resist being killed by macrophages.
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PMID:Inhibition of macrophage priming by sulfatide from Mycobacterium tuberculosis. 282 97

LPS priming of the neutrophil results in enhanced release of superoxide upon subsequent stimulation, but the mechanism of this effect remains obscure. The recent recognition that neutrophils synthesize and retain platelet-activating factor within the cell led us to hypothesize that enhanced synthesis of platelet-activating factor in the LPS-primed cell might account for the observed effects of lipopolysaccharide. Using human neutrophils isolated on plasma-Percoll gradients, we found that incubation with 100 ng/ml LPS for 60 min resulted in a small but significant increase in intracellular platelet-activating factor assessed after lipid extraction, TLC, and bioassay. The further stimulation of primed neutrophils with FMLP resulted in a marked increase in neutrophil platelet-activating factor compared with non-LPS-treated controls. The priming effect of LPS was time dependent (30 to 60 min), dose dependent, and inhibited at 0 degree C and did not require protein synthesis. Platelet-activating factor so generated was not released but rather retained within the neutrophil, and the molecular species of platelet-activating factor produced was predominantly 1-O-hexadecyl-2-acetyl-sn-3-phosphorylcholine. Platelet-activating factor production in LPS-treated neutrophils was also enhanced by PMA, suggesting that receptor-mediated events could not account exclusively for the enhancement. Considering the ability of nanomolar concentrations of exogenously added platelet-activating factor to prime the neutrophil for enhanced release of superoxide, the rapid intracellular accumulation of platelet-activating factor that accompanies stimulation of an LPS-primed cell by FMLP may modulate the secretory events that accompany such stimulation.
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PMID:The priming of neutrophils by lipopolysaccharide for production of intracellular platelet-activating factor. Potential role in mediation of enhanced superoxide secretion. 283 41

The capacity of B cells to serve as stimulator cells for a primary mixed leukocyte reaction (MLR) was evaluated. Percoll-fractionated B cells were stimulated with lipopolysaccharide and dextran sulfate (L/D) or a B cell stimulatory factor (BSF-1)-containing culture supernatant, and then were fixed before being used as stimulator cells to more precisely define the state of activation associated with MLR stimulatory capacity. It was found that unstimulated B cells or B cells stimulated for 1 day with L/D or BSF-1 were incapable of initiating a primary MLR, whereas B cells incubated for 3 days in L/D were potent stimulators. The differential activity of 1 day L/D- and BSF-1-activated B cells compared with 3 day L/D-activated B cells was not related to the amount of the relevant MHC class I or class II alloantigens on these cell populations, because all three groups had large increments in MHC class II expression in the following order: BSF-1 greater than 3 day L/D greater than 1 day L/D, and had little difference in MHC class I expression. Also, all three populations were capable of stimulating both MHC class I- and class II-specific T cell hybrids. It was concluded that the capacity of 3 day L/D-activated cells to stimulate a primary MLR was due to the elaboration of necessary co-stimulator molecules. We evaluated whether interleukin 1 (IL 1) was the co-stimulator involved. That this was not the case was indicated by two findings. First, 3 day-activated L/D cells failed to express IL 1 activity as measured by a highly sensitive IL 1 assay that utilizes the T cell line D10.G4.1. Second, recombinant IL 1 added to MLR cultures containing 1 day L/D- or BSF-1 activated B cells failed to function as a co-stimulator. In contrast, the phorbol ester PMA was a potent co-stimulator in this system. We conclude from these experiments that appropriately activated B cells can function as stimulators of a primary MLR, and that they elaborate critical co-stimulator molecules, distinct from IL 1, that enable them to function in this regard.
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PMID:Capacity of B cells to function as stimulators of a primary mixed leukocyte reaction. 294 57

Antibodies directed against the human T cell receptor or the closely associated CD3 molecule stimulate polyclonal T cell proliferation via mechanisms that mimic a primary immune response. We have investigated the requirement for IL-1 production in anti-CD3 (OKT3)-mediated mitogenesis using a Hodgkin's disease cell line (L428) as the accessory cell. L428 cells did not produce detectable IL-1 following stimulation with lipopolysaccharide or phorbol ester (PMA), nor did they transcribe detectable levels of mRNA for IL-1 alpha or beta after such treatment. Despite their inability to produce IL-1, as few as 1 X 10(4) L428 cells reconstituted the proliferative response of accessory cell-depleted T cells to anti-CD3. Although larger numbers of non-rosette-forming (E-) cells were required for maximal responsiveness to anti-CD3, the maximal degree of proliferation was higher with E- cells than with L428 cells. L428-mediated T cell proliferation did not result from residual accessory cells in the responding population or an allogeneic effect since L428 cells were also capable of providing accessory cell activity for the anti-CD3-dependent generation of IL-2 by the Jurkat T cell line. Although the mechanism by which L428 cells provide accessory functions remains incompletely characterized, the ability of anti-HLA-DR F(ab')2 fragments to completely abrogate L428 and monocyte-mediated anti-CD3 mitogenesis, despite the addition of exogenous IL-1, provides evidence for the participation HLA-DR molecules in this response. These data indicate that anti-CD3-induced proliferation of unprimed human T lymphocytes can occur independently of IL-1 production by accessory cells and may involve the participation of HLA-DR molecules.
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PMID:Interleukin-1-independent activation of human T lymphocytes stimulated by anti-CD3 and a Hodgkin's disease cell line with accessory cell activity. 297 87

Covalent modification of proteins via phosphorylation is a well-documented mechanism whereby intracellular events are controlled by external stimuli. Treatment of thioglycollate-elicited, C57Bl/6 murine peritoneal macrophages with nanogram quantities of bacterial lipopolysaccharide (LPS) consistently results in altered 32Pi labeling of a specific set of proteins (e.g., proteins of 67, 37, 33, and 28 kD), as measured by autoradiography after SDS-polyacrylamide gel electrophoresis. Induction of this pattern of phosphorylation is duplicated by the lipid A moiety of LPS. The LPS-stimulated changes in phosphate labeling are both dose- and time-dependent. Of various pharmacologic agents tested, the phosphorylation pattern induced in macrophages by the tumor promoter phorbol myristic acetate shows similarity to the pattern induced by LPS. Analysis of pp 28 and pp 37 from both LPS- and PMA-treated macrophages by limited proteolysis demonstrates that these phosphoproteins are structurally related and that the sites of phosphorylation are similar for both treatment conditions. Macrophages from the genetically LPS-unresponsive C3H/HeJ strain show no alteration in their pattern of phosphorylation after treatment with LPS. Control macrophages, from C3H/HeN mice, respond to LPS in a fashion identical to that seen in C57Bl/6 macrophages. Pretreatment of macrophages with IFN-gamma potentiates the effect of LPS (i.e., yields a level of altered phosphate labeling greater than that observed with LPS or PMA alone). Together, the data indicate that LPS causes altered phosphate labeling of a defined set of proteins, and that the circumstances of this response are consistent with a possible role in coupling LPS-initiated signals to the induction of functional competence in macrophages.
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PMID:LPS induces altered phosphate labeling of proteins in murine peritoneal macrophages. 308 77

We examined the effect of interferon (IFN)-alpha and IFN-gamma on the ability of human monocytes to secrete interleukin 1 (IL 1). IFN-alpha directly induced IL 1 secretion by monocytes. IFN-gamma did not induce any IL 1. IFN-gamma-stimulated monocyte supernatants were also negative for pyrogenic activity. However, IFN-gamma greatly enhanced the amount of IL 1 secreted when monocytes were stimulated by lipopolysaccharide or Staphylococcus aureus, even at concentrations which by themselves did not induce IL 1. IFN-alpha did not enhance IL 1 secretion induced by other stimuli. IFN-gamma enhanced IL 1 secretion by priming monocytes to be more sensitive to an IL 1-inducing stimulus. However, IFN-gamma does not enhance IL 1 induced by all stimuli, because there was no enhancement of IL 1 induced by PMA. Thus, IFN-alpha and IFN-gamma have very distinct roles in the induction and enhancement of IL 1 by monocytes.
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PMID:Differential effects of interferon-alpha and interferon-gamma on interleukin 1 secretion by monocytes. 310 69


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