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)

Tumor necrosis factor alpha (TNF) is a peptide monokine involved in a number of immune reactions. To further understand the role of TNF in disease states it is critical to have an inexpensive, yet sensitive and specific assay. Additionally, the effects of prostaglandin E2 (PGE2), dexamethasone (dex), and cyclosporine A (CsA) on TNF gene expression have been studied, although little is known of the effects these compounds have on TNF containing samples. The aim of this study is to determine the sensitivity and specificity of a highly sensitive cell line to the actions of TNF, and to elucidate parameters which affect the stability of TNF in biological fluids. Dex and PGE2 at concentrations of 10(-5), 10(-7), and 10(-9) M, were shown not to effect the WEHI assay, and neither did CsA (10 ng/ml-1 ug/ml). The cells were not lysed by recombinant murine IL-1 alpha or beta, human recombinant IL-1 alpha or beta, human recombinant IL-2 or human recombinant IL-6 at concentrations ranging from 0.02 pg/ml to 1.0 ug/ml, or murine gamma-IFN from 100 pg/ml to 10 ng/ml. TNF containing samples with 1%-10% fetal calf serum maintained their cytolytic activity even after three freeze-thaw cycles. Serum samples did not lose any cytolytic activity with up to 11 cycles of freezing and thawing whereas, tissue culture media, containing TNF, lost significant activity with freeze-thawing. The WEHI assay has successfully detected cytolytic activity from lipopolysaccharide stimulated specimens from a number of different species. These data show the utility of this highly sensitive and specific assay. Furthermore, the WEHI assay showed a high degree of reproducibility in repeated assays.
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PMID:WEHI 164 subclone 13 assay for TNF: sensitivity, specificity, and reliability. 211 Sep 31

Infection of mice with lymphocytic choriomeningitis virus (LCMV) produces a rapidly induced immuno-suppression manifested by low lymphocyte proliferation in response to lipopolysaccharide (LPS) and concanavalin A (ConA). Analysis of the mechanisms underlying the unresponsiveness to these mitogens was undertaken at the cellular and molecular levels 7 days after infection. The selective elimination of CD8+ T cells and the results of coculture experiments demonstrated that unresponsiveness was not due to suppressor cells. Similarly, the role of inhibitory factors such as prostaglandins was excluded, since indomethacin, which inhibits their production, did not reverse the unresponsiveness. Analysis of different cytokines secreted by ConA-activated macrophages or T cells revealed that interleukin-1 (IL-1), synthesized during the T-dependent activation of macrophages by ConA, was normally produced by cells from LCMV-infected mice. In contrast, IL-2, which is produced by activated CD4+ T cells, was undetectable. Addition of exogenous IL-2 did not restore the proliferative response, although the p55-kilodalton protein of the IL-2 receptor was induced by ConA on CD4+ cells from LCMV-infected mice. Our results can be interpreted as showing that (i) unresponsiveness to mitogens of cells from LCMV-infected mice is not due to altered functions of the macrophages with respect to IL-1 production; (ii) CD4+ cells are activated, since the p55 chain of the IL-2 receptor is induced; (iii) the lack of IL-2 production cannot explain T-cell unresponsiveness, since addition of exogenous IL-2 did not restore the proliferative response. Taken together, these data suggest that T-lymphocyte unresponsiveness should be related to an inherent proliferative defect subsequent to T-cell activation and IL-2 receptor expression.
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PMID:Lymphocytic choriomeningitis virus-induced immunodepression: inherent defect of B and T lymphocytes. 214 39

We have previously shown that albumin-complexed stearic acid (18:0) inhibited in vitro primary anti-TNP plaque-forming cell (PFC) responses to trinitrophenyl keyhole limpet hemocyanin (TNP-KLH), but did not affect primary PFC responses to trinitrophenyl lipopolysaccharide (TNP-LPS). The present studies were done to identify the cellular target of fatty acid inhibition. The addition of 18:0 at the initiation of antibody cultures exerted a dose-dependent inhibitory effect on subsequent PFC responses to TNP-KLH, and removal of the fatty acid after 20 h did not reverse its inhibitory effect. Preincubation of isolated T-cells with TNP-KLH and 18:0 resulted in a similar inhibition of subsequent PFC responses, but a preincubation of isolated B-cells had no effect. The addition of 18:0 to the culture system in vitro led to a marked reduction in the level of IL-2 detectable in culture supernatants, and PFC responses could be restored by providing exogenous mouse recombinant IL-2. The addition of antigen-primed T-helper cells to antibody cultures partially abrogated the inhibition by 150 microM 18:0, apparently due to their greater production of IL-2. Lastly, following overnight incubation of unfractionated splenic lymphocytes in the presence of TNP-KLH and [1-14C]-18:0, B-cells were shown to contain nearly 5-fold more radiolabeled oleic acid (18:1) than T-cells. Collectively, these findings implicate T-helper cells as the principle target of 18:0-inhibition of primary antibody responses in vitro, possibly as a result of the inability of T-helper cells to avoid an over accumulation of stearic acid in their membrane phospholipids.
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PMID:Identification of T-helper cells as the target of stearic acid-inhibition in primary antibody responses in vitro. 214 47

Activities of IL-1 produced by peripheral blood monocytes stimulated with lipopolysaccharide and IL-2 released by peripheral blood mononuclear cells induced by PHA, SWAP and SEA in vitro were detected in patients with various stages of schistosomiasis japonica. It was found that the activity of IL-1 was greatly increased and positively related to the body temperature, and high level of IL-2 was induced by SWAP and SEA in the group of acute schistosomiasis. The activity of IL-1 was significantly reduced in the groups of chronic and advanced schistosomiasis, especially in the latter group. The level of IL-2 induced by SWAP and SEA in the groups of chronic and advanced schistosomiasis was significantly lower than that in the group of acute schistosomiasis, but was much higher than that in the group of normal control. The level of IL-2 induced by SWAP and SEA in the cases of acute schistosomiasis was positively related to the activity of IL-1. The results indicate that the specific cellular immunity was increased in acute cases and decreased in chronic cases of schistosomiasis japonica. Both specific and nonspecific cellular immune responses were greatly reduced in cases of advanced schistosomiasis japonica. IL-1 and IL-2 may play an important role in the immunoregulation of schistosomiasis japonica.
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PMID:[Changes in induced interleukin-1 and interleukin-2 activity and their interrelationship in patients with schistosomiasis japonica]. 217 63

In view of the central involvement of interleukin-1 (IL-1) in T-cell functions and the negative effects exerted by cyclic adenosine monophosphate (cAMP) on T-cell responses, we wondered whether these inhibitions rely on defects in IL-1 generation. We investigated the effect of a known cAMP elevating agent, cholera toxin (CT), on the generation of IL-1 from peripheral blood adherent cells as well as the role of IL-1 whenever IL-2 synthesis and IL-2 receptor (CD25 antigen) expression are inhibited. While augmenting intracellular cAMP concentration, CT inhibits from 20 to 40% the generation of IL-1 activity from E. coli lipopolysaccharide (LPS)-stimulated adherent cells. Theophylline (TH), a cAMP degradation blocking agent, induces the same decrease in IL-1 activity. The B chain of CT, devoid of cAMP activating potency, is not inhibitory. In systems where CT and TH dramatically inhibit the generation of IL-2 activity (80%), addition of exogenous IL-1 does not restore the ability of T-cells to produce or release IL-2. Moreover, CT- and dibutyryl (db)cAMP-induced inhibition of CD25 antigen expression is not overcome by exogenous IL-1, IL-2, nor by both interleukins. It is concluded that inhibition of IL-1 and IL-2 production are independent and that inhibition of CD25 antigen expression is independent of IL-1 and IL-2 modulation. Cholera toxin and cAMP influences on interleukin synthesis are discussed.
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PMID:Elevation of cyclic adenosine monophosphate levels independently down regulates IL-1, IL-2, and IL-2 receptor (CD25) syntheses. 217 38

Media conditioned by an interleukin 3 (IL-3)-producing T-cell line, STIL-3, as well as recombinant mouse IL-3 showed granulocyte/macrophage (GM) colony-stimulating activity in the semi-solid culture medium containing horse serum (HS) or bovine serum, but the activity was not apparent when fetal calf serum (FCS) was used. No such serum-dependency of GM colony formation was observed when abdominal wall conditioned medium or L-cell conditioned medium containing GM colony-stimulating factor was used. Although the levels of albumin and total protein were lower in FCS than HS, increase of FCS concentration did not affect the GM colony-stimulating activity of IL-3. Addition of bovine serum albumin (BSA) preparation to FCS, however, increased the number of GM colonies to the same level as that observed with HS. The levels of bacterial lipopolysaccharide (LPS) in sera and BSA and the effect on the bone marrow cells from LPS-nonresponsive C3H/HeJ mice indicated that the observed effect of BSA was not due to the contaminating LPS. The activity of BSA was not substituted by IL-1, IL-2, IL-4, IFN-gamma, TNF, NGF or erythropoietin. The present study suggests the presence in BSA of co-factor(s) of IL-3 in stimulating GM colony formation.
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PMID:Presence of an activity indispensable for the granulocyte/macrophage colony-stimulating activity of interleukin 3 in bovine serum albumin. 217 34

We have investigated that synthetic lipid A subunit analogues (GLA compounds) as well as E. coli type lipopolysaccharide (LPS) and synthetic lipid A (compound 506) are able to stimulate human monocytes to release IL-1 in vitro. Of monosaccharide-type GLA compounds, GLA-60 was found to be more active for the induction of IL-1 production than GLA-59 and GLA-27, and similar to that of LPS or compound 506. GLA-60 could induce not only the secretion of IL-1 into culture supernatant but also the expression of membrane-associated form of IL-1 in human monocytes. Furthermore, no detectable IL-2 activity was observed in the culture supernatant. These results show that synthetic lipid A analogues of low toxicity, in particular GLA-60, are active in inducing IL-1 production in human monocytes.
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PMID:Production of interleukin 1 from human monocytes stimulated by synthetic lipid A subunit analogues. 218 36

We studied the effect of endogenous prostaglandin E2 (PGE2) on interleukin 1 (IL-1) production by peripheral blood monocytes from patients with rheumatoid arthritis (RA). IL-1 production by RA monocytes was not different from that of monocytes from normal controls, when the cells were either unstimulated or stimulated with lipopolysaccharide (LPS, 20 micrograms/ml), as measured by two different bioassays (thymocyte or fibroblast proliferation assay) and enzyme-linked immunosorbent assay. However, IL-1 production by LPS-stimulated monocytes from RA patients cultured in medium containing indomethacin, an inhibitor of PGE2 synthesis, was significantly greater than that of monocytes from normal controls. In addition, the levels of PGE2 in culture supernatants of unstimulated or LPS-stimulated monocytes from RA patients were higher than in culture supernatants of monocytes from normal controls. Moreover, the increase of in vitro IL-2 production by RA T cells stimulated by phytohemagglutinin (PHA) was observed when monocytes were removed from peripheral blood mononuclear cells. These results indicated that peripheral blood monocytes from RA patients could produce IL-1 in excess in vitro, but that in vivo IL-1 production by RA monocytes and IL-2 induction by RA T cells might be negatively regulated by endogenous PGE2.
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PMID:Role of endogenous prostaglandin E2 in interleukin 1 production by peripheral blood monocytes from patients with rheumatoid arthritis. 233 Aug 42

The IgG subclasses secreted by human B cells in vitro in response to IL-2 have been analysed. B cells were prepared from tonsil, blood and spleen, and cultured with recombinant IL-2 in the presence or absence of two polyclonal activators: Staphylococcus aureus Cowan 1 (SAC) and bacterial lipopolysaccharide (LPS). Secretion of all four subclasses and of IgM was stimulated by IL-2, but the relative amounts varied according to (i) the tissue source of the B cells, and (ii) which polyclonal activator was used. The amount of IgG1 tended to be higher and IgG2 tended to be lower when SAC was the polyclonal activator (compared to LPS). This difference was most marked for tonsil B cells, and it was found that SAC had a negative effect on secretion of IgM and IgG2 in these cultures, whilst synergizing with IL-2 to stimulate the production of IgG1, 3 and 4. When the degree of stimulation of different pairs of isotypes was analysed, several interesting positive correlations emerged. In tonsil B-cell cultures, stimulation of IgM and IgG2 was linked with each other, but not with IgG1, whilst in blood B-cell cultures all isotypes appeared to be stimulated co-ordinately. Stimulation of IgG1 and IgG3 were positively correlated in cultures of B cells from all tissues. The results emphasize that the effects of a single cytokine on immunoglobulin isotype production can be influenced by the source of the B cells, and by other signals delivered to the cells.
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PMID:Immunoglobulin G subclasses secreted by human B cells in vitro in response to interleukin-2 and polyclonal activators. 237 16

Subtoxic doses of endotoxin (salmonella abortus equi lipopolysaccharide, LPS) (5 micrograms/kg i.p.) or tumor necrosis factor alpha (TNF alpha) (15 micrograms/kg i.v.) induced fulminant hepatitis within 8 hr, when mice had been sensitized by a subtoxic dose of D-galactosamine (700 mg/kg i.p.). LPS-treatment led to the release of TNF into the circulation, independently of the presence of D-galactosamine. The TNF-dependent development of hepatitis was accompanied by a severe lymphopenia and neutrophilia as assessed by leukocyte differential count. The total leukocyte count was not significantly affected. Lymphopenia and neutrophilia were induced by LPS or TNF alpha alone; however, the differential count was not influenced by D-galactosamine. A quantity of 260 micrograms/kg phorbol myristate acetate (PMA) i.p. or 5 micrograms/kg platelet activating factor (PAF) i.v. or 3.3 mg/kg N-formyl-methionyl-leucyl-phenylalanine methylester (FMLP) i.v. or 167 mg/kg zymosan i.v. also caused lymphopenia and neutrophilia in mice. However, none of these agents induced the production of systemic TNF and therefore failed to induce hepatitis in D-galactosamine-sensitized mice. In LPS-insensitive C3H/HeJ mice administration of LPS produced neither differential count changes nor hepatitis while both events were observed when TNF alpha was given. This shows that TNF alpha alone gives rise to lymphopenia/neutrophilia as well as hepatitis independent of LPS. When the action of TNF alpha was blocked by anti TNF alpha antiserum pretreatment of LPS-sensitive mice, the animals were protected against LPS-induced hepatitis. However, lymphopenia and neutrophilia still occurred to a similar extent. The involvement of a putative additional mediator of LPS-induced leukocyte alterations was checked. The findings suggest that this mediator, if present, is different from IL-1, IL-2, eicosanoids or superoxide. We conclude from our findings that changes in leukocyte numbers and composition following D-galactosamine LPS or D-galactosamine/TNF alpha administration is an epiphenomenon rather than a causal event of leukocyte stimulation in the process of inducing a fulminant hepatitis in mice.
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PMID:Leukocyte alterations do not account for hepatitis induced by endotoxin or TNF alpha in galactosamine-sensitized mice. 240 85


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