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)

Inhalation of 20 micrograms endotoxins (from the membrane of Gram-negative bacteria) has been reported to induce a bronchial obstructive response in asthmatic subjects. The aim of the present study was to evaluate in asthmatic patients the possibility of an inflammatory response to inhaled endotoxins. Eight patients with mild asthma were submitted to bronchial challenge tests, in a single-blind trial, on Day 1 with control solution and on Day 7 with 20 micrograms endotoxin of Escherichia coli (026:B6). Local inflammatory response was indirectly evaluated by the degree of bronchial hyperresponsiveness (BHR) expressed as PD20 FEV1 histamine (the dose of histamine inducing a 20% decrease in FEV1) at 0, 6, 24, and 48 h and 7 days. Systemic inflammation was investigated by sequential blood determinations of total (and differential) white cells, complement anaphylatoxin C5a, interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-alpha), and C-reactive protein (CRP). A significant (p < 0.01) bronchial obstructive response was demonstrable 45 min after lipopolysaccharide (LPS) inhalation, lasting 5 h. Comparing the level of BHR after control inhalation, a significant (p < 0.05) increase in BHR was shown 6 h after LPS, partially normalized at 24 and 48 h. A short peak in TNF-alpha at 60 min (p < 0.05) and an increase in total white blood cells (p < 0.01) and neutrophil polymorphonuclear neutrophils at 360 min (p < 0.05) and of CRP at 24 and 48 h (p < 0.05 and p < 0.01) were significant. The other blood parameters did not change significantly.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Inflammatory response to acute inhalation of endotoxin in asthmatic patients. 148 24

Production of interleukin 1 beta (IL-1 beta), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-alpha), interleukin 2 (IL-2), interferon gamma (IFN-gamma) and granulocyte-macrophage colony-stimulating factor (GM-CSF) after stimulation by lipopolysaccharide (LPS) and phytohemagglutinin (PHA) was studied in 1/10 diluted whole blood (WB) culture and in peripheral blood mononuclear cell (PBMC) culture. Cytokines IL-1 beta, TNF-alpha and IL-6 are preferentially stimulated by LPS whereas IL-2, IFN-gamma and GM-CSF are stimulated by PHA. Combination of 5 micrograms/ml PHA and 25 micrograms/ml LPS gave the most reliable production of the six cytokines studied. IL-1 beta, TNF-alpha and IL-6 represent a homogeneous group of early-produced cytokines positively correlated among themselves and with the number of monocytes in the culture (LeuM3). Furthermore, IL-1 beta was negatively correlated with the number of T8 lymphocytes. IL-2, IFN-gamma and GM-CSF represent a group of late-produced cytokines. Kinetics and production levels of IL-6 and GM-CSF are similar in WB and PBMC cultures. In contrast, production levels of TNF-alpha and IFN-gamma are higher in WB than in PBMC whereas production levels of IL-6 and IL-2 are lower in WB than in PBMC. Individual variation in responses to PHA + LPS was always higher in PBMC cultures than in WB cultures. The capacity of cytokine production in relation to the number of mononuclear cells is higher in WB, or in PBMC having the same mononuclear cell concentration as WB, than in conventional cultures of concentrated PBMC (10(6)/ml). Because it mimics the natural environment, diluted WB culture may be the most appropriate milieu in which to study cytokine production in vitro.
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PMID:Direct stimulation of cytokines (IL-1 beta, TNF-alpha, IL-6, IL-2, IFN-gamma and GM-CSF) in whole blood. I. Comparison with isolated PBMC stimulation. 149 59

Cellular protection from immune-generated oxygen free radicals is initiated by the reduction of oxygen radicals by manganese superoxide dismutase (MnSOD) and copper/zinc superoxide dismutase (Cu/ZnSOD). Using rat adult (IEC-6) and fetal (IRD-98) intestinal epithelial cell lines, factors involved in the regulation of the SODs at the messenger RNA (mRNA) level were examined. Exposure of IEC-6 and IRD-98 to Escherichia coli lipopolysaccharide (LPS) or tumor necrosis factor alpha (TNF-alpha) results in a marked increase in MnSOD mRNA as early as at 1 hour. Cotreatment of cells exposed to LPS or TNF-alpha with actinomycin D or cycloheximide showed that de novo transcription but not protein synthesis is required for the LPS- and TNF-alpha-dependent induction in MnSOD mRNA. Treatment with interleukin 1 beta results in a 12-fold increase in MnSOD mRNA, but no change was observed with interleukin 6 or interferon alpha. No change was observed in the level of Cu/ZnSOD mRNA under any condition tested. The results indicate that MnSOD functions as a cytokine-regulated acute phase protein involved in cellular protection from free radical-mediated damage.
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PMID:Acute-phase induction of manganese superoxide dismutase in intestinal epithelial cell lines. 149 41

In this study, we examined the role of interleukin-6 (IL-6) in the development of chronic lung inflammatory conditions, using a mouse model of hypersensitivity pneumonitis established by intranasal instillation of the thermophilic actinomycete Faeni rectivirgula. Challenged mice developed an early neutrophilic response at 24 h, followed by a macrophage/lymphocyte recruitment. The impact of IL-6 on the development of the inflammatory response was assessed by giving infusions of a monoclonal antibody against IL-6 so as to deplete endogenous levels of this cytokine or by giving exogenous IL-6 to challenged mice. Mice challenged intranasally with the actinomycete and given the anti-IL-6 antibody developed a strong, sustained neutrophilic response, with a significantly higher lung free cell number than control mice. Assessment of fibrosis by measuring lung hydroxyproline levels showed that challenged mice given anti-IL-6 developed more significant fibrosis than control mice. Conversely, infusions with IL-6 diminished F. rectivirgula-induced cell recruitments and the fibrotic response in the lungs. Moreover, alveolar macrophages from mice given 2 weeks of F. rectivirgula treatment released high levels of tumor necrosis factor alpha (TNF-alpha) bioactivity upon in vitro lipopolysaccharide challenge, compared to mice instilled with saline only. This TNF-alpha activity produced by macrophages was decreased by in vivo IL-6 treatment and enhanced by in vivo neutralization with anti-IL-6. These observations suggest that IL-6 may play a role in regulating the cellular recruitment in the lungs during an inflammatory response, with dramatic consequences for the cellular profile in the bronchoalveolar lavage and the subsequent fibrosis.
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PMID:Interleukin-6 in mouse hypersensitivity pneumonitis: changes in lung free cells following depletion of endogenous IL-6 or direct administration of IL-6. 150 76

Interleukin 10 (IL-10) inhibits interferon gamma-induced macrophage activation for cytotoxicity against larvae of the human parasite Schistosoma mansoni by suppressing production of the toxic effector molecule nitric oxide (NO). In this study, the mechanism of IL-10 action was identified as inhibition of endogenous tumor necrosis factor alpha (TNF-alpha) production by interferon gamma-activated macrophages. TNF-alpha appears to serve as a cofactor for interferon gamma-mediated activation, since both schistosomulum killing and NO production were inhibited by anti-TNF-alpha antibody, whereas TNF-alpha alone was unable to stimulate these macrophage functions. IL-10 blocked TNF-alpha production by interferon gamma-treated macrophages at the levels of both protein and mRNA synthesis. Addition of exogenous TNF-alpha reversed IL-10-mediated suppression of macrophage cytotoxic activity as well as NO production. Likewise, addition of a macrophage-triggering agent (bacterial lipopolysaccharide or muramyl dipeptide), which induced the production of TNF-alpha, also reversed the suppressive effect of IL-10 on cytotoxic function. In contrast to IL-10, two other cytokines, IL-4 and transforming growth factor beta, which also inhibit macrophage activation for schistosomulum killing and NO production, did not substantially suppress endogenous TNF-alpha production. These results, therefore, describe a separate pathway by which macrophage microbicidal function is inhibited by the down-regulatory cytokine IL-10.
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PMID:Interleukin 10 inhibits macrophage microbicidal activity by blocking the endogenous production of tumor necrosis factor alpha required as a costimulatory factor for interferon gamma-induced activation. 152 80

A recently identified novel mammalian cyclin (CYL1), induced by growth factors and apparently functional during the G1 phase of the cell cycle, is of potential significance, given that cell division is primarily controlled in G1. We have measured CYL1 gene expression in murine bone marrow-derived macrophages (BMM), a normal cell type dependent upon colony-stimulating factors (CSFs) for survival and proliferation. The induction of CYL1 mRNA levels correlated strongly with stimulation of DNA synthesis, since elevated CYL1 mRNA levels occurred in response to the mitogenic stimuli, CSF-1, and granulocyte/macrophage CSF, but not to nonmitogenic macrophage-activating agents. BMM are subject to cell cycle arrest by numerous agents, including tumor necrosis factor alpha, interferon gamma, bacterial lipopolysaccharide, and agents that increase cAMP. These antiproliferative agents suppressed CSF-1-stimulated CYL1 gene expression, even when added late in G1. This pattern of CYL1 gene expression was remarkably consistent with the ability of these agents to inhibit progression into S phase. The mechanisms of negative growth regulation are largely unknown, and given the likely importance of G1 cyclins in the control of cell division, we propose that antiproliferative agents may exert their effects by suppressing G1 cyclin gene expression.
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PMID:Suppression of growth factor-induced CYL1 cyclin gene expression by antiproliferative agents. 153 6

Autoantigen recognition by specific T cells may initiate a tissue-specific immune response in multiple sclerosis (MS), which is a chronic inflammatory demyelinating disorder. During subsequent nonspecific immune amplification, interleukin 1 beta and tumor necrosis factor alpha are released by cells of the monocyte/macrophage lineage, with the potential to influence profoundly immune regulation systemically or within the central nervous system. Regulation of monocyte inflammatory gene expression may be relevant to the pathogenesis of MS. We investigated spontaneous secretion of interleukin 1 beta, tumor necrosis factor alpha, and prostaglandin E2 with the use of monocytes that we isolated from patients with active (n = 9) and stable (n = 9) MS and from age-matched normal controls (n = 9). The patient groups with MS were matched for age, duration of MS, and disease severity. Patients with active disease were within weeks of the onset of a clinical exacerbation. Monocytes were isolated by density gradient centrifugation, followed by adherence to plastic tissue culture flasks, resulting in a highly purified adherent monocyte preparation. Monocytes from patients with active disease spontaneously secreted less tumor necrosis factor alpha and less prostaglandin E2 compared with that in patients with stable MS, while interleukin 1 beta levels were below the level of assay sensitivity. Levels of interleukin 1 beta and tumor necrosis factor alpha increased to similar levels in response to lipopolysaccharide (0.1 mg/L), indicating that altered cell viability could not account for the observed differences. In response to lipopolysaccharide, prostaglandin E2 levels increased more significantly in patients with stable than active MS, suggesting differential sensitivity to stimuli of arachidonic acid metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Cytokine secretion by multiple sclerosis monocytes. Relationship to disease activity. 153 29

We have recently reported that chronic and systemic administration of tumor necrosis factor alpha (TNF) inhibits development of autoimmune diabetes in NOD mice and BB rats, animal models of insulin-dependent diabetes mellitus (IDDM). During these experiments, we unexpectedly found that in vivo production of TNF stimulated by a single injection of lipopolysaccharide was enhanced approximately 10 times in the long-term diabetic BB rats (P less than 0.0001), whose mean duration of diabetes with more than 16.8 mM (300 mg/dl) of nonfasting blood glucose level was 26.2 +/- 2.1 days, as compared to that in the rats of nondiabetes and in the rats at the onset of diabetes, whose mean duration of diabetes was 1.4 +/- 0.6 days. The long-term diabetic, but not short-term-diabetic, rats were also associated with increased levels of serum fructosamine/albumin (P less than 0.01) and triglyceride (P less than 0.01) and with a decreased level of serum albumin (P less than 0.01). The in vivo TNF productivity in the diabetic rats, including the short-term- and long-term-diabetic rats, was correlated positively with the level of fructosamine/albumin (P less than 0.05) and negatively with the level of serum albumin (P less than 0.05), but not with levels of blood glucose. None of these correlations were observed in nondiabetic rats. The increased LPS-induced serum TNF activity in the long-term diabetic state was observed not only in BB rats but also in NOD mice and GK rats, a model of non-IDDM, irrespective of sexes and ages, indicating that the enhancement of in vivo TNF production was a result of long-term diabetes. These findings indicate that some factor(s) associated with the long-term-diabetic state may prime macrophages in vivo to produce TNF. Further study is needed to reveal a mechanism of the enhanced TNF production and its possible relevance to various abnormalities associated with the chronic hyperglycemic state.
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PMID:Increased in vivo production of tumor necrosis factor after development of diabetes in nontreated, long-term diabetic BB rats. 154 Oct 51

Nocardia asteroides modulates phagocyte function and grows within macrophages. Because interferon gamma (IFN-gamma) and tumor necrosis factor alpha (TNF-alpha) have been shown to activate macrophages to kill a variety of microorganisms, the effects of IFN-gamma and TNF-alpha on the activation of murine macrophages and human monocytes to kill nocardiae were studied. It was found that macrophages or monocytes treated with either IFN-gamma, TNF-alpha, or lipopolysaccharide as a secondary signal did not demonstrate increased microbicidal activity against N. asteroides even though these phagocytes were effective at killing the fungus Coccidioides immitis and the protozoan Toxoplasma gondii. Preincubation of phagocytes for 24 h with these compounds resulted in an enhancement of nocardial growth. In contrast, coincubation of these factors with the nocardiae and mononuclear cells during phagocytosis resulted in inhibition of nocardial growth even though this bacterium was not killed. Therefore, the specific timing of the exposure of the phagocyte in vitro to IFN-gamma or TNF-alpha has a significant effect on its ability to alter nocardial growth.
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PMID:The timing of exposure of mononuclear phagocytes to recombinant interferon gamma and recombinant tumor necrosis factor alpha alters interactions with Nocardia asteroides. 154 9

Brucella abortus may be useful as a component of vaccines. This is because it possesses several unique properties as a carrier that enable it to stimulate human B cells even in the relative absence of T cells. Human immunodeficiency virus type 1 proteins conjugated to B. abortus could induce neutralizing antibodies against human immunodeficiency virus type 1. Recently we showed that the characteristics of lipopolysaccharide (LPS) derived from B. abortus are similar to those of the whole bacterium in that the LPS acts as a T-independent type 1 carrier in mice. In this study we wanted to determine whether LPS derived from B. abortus is associated with the adverse effects seen with other bacterial endotoxins. LPS purified from B. abortus by butanol extraction was shown to have less than 2% (wt/wt) contamination by protein and less than 1% (wt/wt) contamination by nucleic acids and to contain 1% (wt/wt) ketodeoxyoctanic acid. Compared with LPS derived from Escherichia coli, B. abortus LPS was 10,000-fold less potent in eliciting fever in rabbits, 268-fold less potent in killing D-galactosamine-sensitized mice, and 1,400-fold and 400-fold less potent in inducing interleukin-1 beta and tumor necrosis factor alpha production, respectively. These results suggest that B. abortus LPS is much less likely than the LPS from E. coli to evoke endotoxic shock; therefore, it may be feasible to incorporate B. abortus as a component of vaccines.
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PMID:Lipopolysaccharide (LPS) from Brucella abortus is less toxic than that from Escherichia coli, suggesting the possible use of B. abortus or LPS from B. abortus as a carrier in vaccines. 154 64


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