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)

We have shown that several human malignant glioma cell lines are stimulated by bacterial lipopolysaccharide (E. coli 0111:B4, 1 microgram/ml) to produce a high molecular weight (> 200 kD) growth activity for BALB 3T3, clone A31 cells. This glioma-derived growth factor (GDGF-2) acts like a 'competence' factor. Malignant glioma cell line D-54 MG constitutively produced GDGF-2, which we have partially characterized from serum-free conditioned culture medium. GDGF-2 is resistant to heat (100 degrees C, 5 min), acidic (pH 2, 2 hr) or reducing (0.5 M 2 ME, 30 min) conditions as well as exposure to RNases; however, it is sensitive to > 4 freeze-thaw cycles, alkaline (pH 11, 2 hr) conditions or pre-treatment with proteolytic enzymes. GDGF-2 had a pl of 6.8 determined by preparative isoelectric focusing, bound to DEAE, with elution at 35 and 185 mM NaCl and at 43% acetonitrile from a C4 reversed phase column. GDGF-2 activity was not neutralized by antibodies to TGF alpha, TGF beta, PDGF, VEGF or TNF alpha indicating that it is not immunochemically related to these growth factors. However GDGF-2 co-chromatographed on Superose 12 HPLC (250 x 9 mm; 5% isopropanol, 6 mM CHAPS in PBS) with a substance that suppressed growth of mink lung epithelial cells (Mv1Lu), but not BALB 3T3 cells, and could be neutralized by anti-TGF beta antibodies. GDGF-2 activity eluted from heparin columns in 0.6 M NaCl; thus, it is not a heparin binding growth factor. D-54 MG cell line produced alpha 2-macroglobulin (alpha 2M), which is known to bind TGF beta; however, immunoprecipitation of alpha 2M did not deplete TGF beta or GDGF-2 activity. Further, neither GDGF-2 or TGF beta can be dissociated into lower molecular weight active components by chromatography in high salt (2 M NaCl) or 2-ME (0.5 M). GDGF-2 may be a novel autocrine or paracrine mitogen, stimulating mitotic division or interfering with normal cell growth regulation.
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PMID:Partial characterization of glioma-derived growth factor 2: a novel mitogenic activity from human cell line D-54 MG. 814 64

An outbreak of Brucella melitensis in a family was studied. From the fourteen family members who ate unpasteurized goat cheese nine became ill. Patients included four females and five males of 8 to 75 years old. In seven of the patients the diagnosis was confirmed by positive blood culture for B. melitensis biovar 1. All the patients were analyzed by standard tube agglutination (STA) and standard tube agglutination with 2-mercaptoethanol (STA-2ME) tests at the time of diagnosis. In six of the patients, ELISA assays were used to assess the humoral immune anti-protein and anti-lipopolysaccharide (LPS) responses. Anti-LPS IgG antibodies were detected in all of the patients. Anti-proteins IgG antibodies were present at significant levels in all the studied patients including the STA-2ME negative ones.
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PMID:Urban outbreak of a Brucella melitensis infection in an Argentine family: clinical and diagnostic aspects. 815 50

Culture supernatants of lipopolysaccharide-stimulated P388D1 macrophage-like tumor cells showed a growth inhibitory effect on plasmacytoma MOPC-315, MPC-11 and myeloma FO cells, but had no effect on J558 plasmacytoma cells. Based on the results of trypan blue staining and a 51Cr release assay, the supernatant had both cytotoxic and cytostatic activity for MOPC-315 plasmacytoma cells. The inhibitory activity was trypsin-sensitive, heat-stable at 100 degrees C for 20 min., but sensitive to 2-mercaptoethanol and cystein HCl. At least 6 hrs of exposure period were required for the P388D1 culture supernatant to show an inhibitory effect on plasmacytoma cells. Since the inhibitory activity could not be blocked by protease inhibitor or neutralized by antibodies to mouse IL-1 beta, IL-6 and TNF-alpha, the inhibitory factor(s) was distinct from the defined cytotoxic factors. After partial purification with DEAE-Sephacel and Sephacryl S-300 chromatography, four major active peaks with the molecular mass of 874-KDa (near the void volume), 112-KDa, 45-KDa and 18-KDa were obtained.
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PMID:Inhibitory effect of lipopolysaccharide-stimulated P388D1 macrophage-like cells on plasmacytoma cells. 835 65

In order to induce an optimal plaque-forming cell response to sheep red blood cells (anti-SRBC PFC response) in vitro, murine splenocytes have been cultured in RPMI 1640 medium containing 10% fetal calf serum (FCS). In this paper, we report that 10% intact FCS in such a conventional medium can be replaced by 2% modified FCS which has been exposed to insoluble polymer beta-cyclodextrin (CD). The most efficient procedure of treatment of FCS was an incubation of 1/50 diluted FCS with 20 mg/ml polymer beta-CD for 3.5 h at 20 degrees C. The PFC response supported by 2% polymer beta-CD-treated FCS, was the same as that obtained when mixing 10% FCS, and was completely dependent on the existence of antigen (SRBC) and enhanced by 2-mercaptoethanol. The time-course profiles of the PFC responses induced in both cultures were almost the same. The 2% polymer beta-CD-treated FCS-containing medium was also effective in inducing both a primary PFC response to the T cell-independent antigen (trinitrophenyl-lipopolysaccharide) and a polyclonal PFC response stimulated by lipopolysaccharide. Inactive FCS lots (so called deficient lots) also became fully supportive at 2% after treatment with polymer beta-CD. These results indicate that polymer beta-CD-treated FCS is not economical for supporting antibody production, but also useful for those experiments on isolation and analysis of factors derived from cultured lymphocytes.
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PMID:Application of polymer beta-cyclodextrin-treated fetal calf serum to in vitro antibody production. 844 48

To investigate the effect of the heme moiety of malaria pigment, hemozoin, on phagocyte functions, mouse macrophages were fed with insoluble beta-hematin, the synthetic heme-polymer chemically identical to the native pigment, or the soluble monomer, hematin. Production of inflammatory cytokines, interleukin 1 (IL1), tumor necrosis factor alpha (TNF alpha), and nitric oxide (NO) was assayed in the supernatants after stimulation with lipopolysaccharide. The results indicate that both beta-hematin and hematin induce a dose-dependent inhibition of macrophage production of TNF alpha and NO, but not of IL1. One-hour pretreatment with soluble hematin inhibited production of cytotoxic mediators by more than 50% compared to controls, while 6-hr exposure was necessary for insoluble beta-hematin to induce the same level of inhibition. However, the same treatment did not modify the production of TNF alpha and NO by mouse microglia cell lines. The inhibition was partially counterbalanced by adding sulphydryl group donors such as 2-mercaptoethanol, glutathione, or N-acetyl-cysteine during the preincubation time. The results of the present study confirm the inhibitory role of malaria pigment and show that such effect is due to the heme moiety and may be selective for the production of cytotoxic mediators by specific phagocytes. The implications of these findings in the control of malaria infection and disease and in the pathogenesis of severe malaria are discussed.
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PMID:The heme moiety of malaria pigment (beta-hematin) mediates the inhibition of nitric oxide and tumor necrosis factor-alpha production by lipopolysaccharide-stimulated macrophages. 854 91

A serological 2-year follow-up of 35 patients who had brucellosis with different clinical outcomes was performed. Patients were followed up by standard tube agglutination (STA) and 2-mercaptoethanol STA (2ME-STA) tests and by two enzyme-linked immunosorbent assays (ELISAs) to independently measure values of serum IgG to either lipopolysaccharide (LPS) or cytoplasmic proteins of Brucella. Whereas STA and 2ME-STA tests revealed characteristic antibody profiles for patients who recovered (group I), this was not the case for patients with persistent illness (group II) or patients with relapses (group III). On the other hand, titers measured by the 2ME-STA test were low or negative in 10 patients who had positive blood cultures. Levels of IgG antibodies to LPS and proteins in each group of patients exhibited characteristic changes. For group I, however, antibodies to proteins were better predictors of recovery, since titers reached negative values for five patients. Levels of IgG antibodies to LPS and proteins were persistently high in group II patients, and peaks in these antibody levels corresponded with relapses in group III patients. The determination of values of IgG antibodies to proteins by ELISA appears useful for the serological follow-up of patients with brucellosis.
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PMID:Serological follow-up of human brucellosis by measuring IgG antibodies to lipopolysaccharide and cytoplasmic proteins of Brucella species. 885 61

Our previous studies have shown that the degree of damage to a liposome corresponds to the variability of the animal species from which the serum comes, and that a complement activating factor (CAF) plays an important role in inducing the activation of the complement system, ultimately leading to the lysis of the liposomes. In this study, our attention focused on the characterization of the bovine serum factor (bCAF) that is involved in complement-mediated immune lysis of the liposome. The active fraction containing CAF partially purified with PEG and ammonium sulfate results in marked activation of the complement system via the alternative pathway when interacted with CAF-depleted serum, whereas the active fraction or CAF-depleted serum alone does not activate the complement. The interaction between lipopolysaccharide (LPS), heparin, zymosan or their mixture in place of CAF and CAF-depleted serum does not result in any significant activation of the complement system. Results from pretreatment with rabbit anti-bovine IgM IgG and rabbit anti-bovine IgG IgG indicate that activation of the complement system is not attributable to the antibody which is generally involved in activation of complement via the classical pathway. The results have further been proven by pretreatment with Concanavalin A (Con A) sepharose and protein G sepharose ruling out the possibility of antibody-mediated activation of complement. Our studies on collagenase and trypsin digestion demonstrate that the relative activity of CAF does not diminish with increase in collagenase concentration, and decreases with increase in trypsin concentration, strongly indicating that CAF does not have a collagen-like domain in its structure. The relative activity of CAF is dramatically inhibited after reduction with 2-mercaptoethanol (2-ME), clearly demonstrating that CAF is sensitive to reduction with 2-ME and confirming a sulhydryl-dependent protein. The optimal activity of CAF is observed in the range of 35-45 degrees C and its half-life at 37 degrees C is about 105 h. Furthermore, the relative activity of CAF increases and gradually approaches a plateau level with the increase of Mg2+ concentration. Obviously, complement activation induced by CAF depends on adequate Mg2+ concentration, confirming that this dependence is characteristic of the alternative pathway.
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PMID:Characterization of bovine serum factor triggering the lysis of liposomes via complement activation. 958 79

Conjugate vaccines were prepared by binding hydrazine-treated lipopolysaccharide (DeALPS) from Vibrio cholerae O1, serotype Inaba, to cholera toxin (CT) variants CT-1 and CT-2. Volunteers (n = 75) were injected with either 25 microg of DeALPS, alone or as a conjugate, or the licensed cellular vaccine containing 4 x 10(9) organisms each of serotypes Inaba and Ogawa per ml. No serious adverse reactions were observed. DeALPS alone did not elicit serum LPS or vibriocidal antibodies in mice and only low levels of immunoglobulin M (IgM) anti-LPS in the volunteers. Recipients of the cellular vaccine had the highest IgM anti-LPS levels, but the difference was not statistically significant from that elicited by the conjugates. The conjugates elicited the highest levels of IgG anti-LPS (DeALPS-CT-2 > DeALPS-CT-1 > cellular vaccine). Both conjugates and the cellular vaccine elicited vibriocidal antibodies: after 8 months, recipients of cellular vaccine had the highest geometric mean titer (1,249), followed by DeALPS-CT-2 (588) and DeALPS-CT-1 (330). The correlation coefficient between IgG anti-LPS and 2-mercaptoethanol (2-ME)-resistant vibriocidal antibodies was 0. 81 (P = 0.0004). Convalescent sera from cholera patients had a mean vibriocidal titer of 2,525 that was removed by treatment with 2-ME. The vibriocidal activities of sera from all vaccine groups and from the patients were absorbed (>75%) by LPS but not by either CT-1 or CT-2. Conjugate-induced IgG vibriocidal antibodies persisted longer than those elicited by the whole-cell vaccine. Both conjugates, but not the cellular vaccine, elicited IgG anti-CT.
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PMID:Phase 1 evaluation of Vibrio cholerae O1, serotype Inaba, polysaccharide-cholera toxin conjugates in adult volunteers. 963 71

Cytokines and reactive oxygen intermediates (ROI) are frequent companions at sites of acute inflammation. We have shown previously that in human monocytes, bacterial lipopolysaccharide, IL-1, and tumor necrosis factor-alpha induce a rapid down-regulation of the monocyte chemotactic protein-1 receptor CCR2 (CC chemokine receptor-2). These stimuli also induce production of ROI. In this paper, we investigate the influence of antioxidants and/or ROI on chemokine-receptor expression. In human monocytes, the antioxidant pyrrolidine dithiocarbamate (PDTC) rapidly inhibited CCR2 (95-100% of inhibition) and CCR5 (77-100% of inhibition) mRNA expression by strongly decreasing transcript stability. CCR2 half-life was decreased from 1.5 h to 45 min; CCR5 half-life was decreased from 2 h to 70 min. This inhibitory activity also included CXCR4 (CXC chemokine receptor-4) but not CXCR2 receptor and, although to a lesser extent, was shared by the antioxidants N-acetyl-l-cysteine and 2-mercaptoethanol. In contrast, the ROI-generating system xanthine/xanthine oxidase increased CCR5 and CXCR4 mRNA expression and counteracted the inhibitory effect of PDTC. Accordingly, H(2)O(2) and the glutathione-depleting drug buthionine sulfoximine increased to different extents CCR2, CCR5, and CXCR4 mRNA expression. The PDTC-mediated inhibition of CCR5 and CXCR4 mRNA expression was associated with decreased chemotactic responsiveness (>90% inhibition) and with a marked inhibition of surface-receptor expression. In contrast, xanthine/xanthine oxidase opposed the bacterial lipopolysaccharide- and tumor necrosis factor-alpha-mediated inhibition of CCR5 and CXCR4 mRNA expression and increased both the CCR5 surface expression and the cell migration (3-fold) in response to macrophage inflammatory protein-1beta. These results suggest that the redox status of cells is a crucial determinant in the regulation of the chemokine system.
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PMID:Redox regulation of chemokine receptor expression. 1071 98

The methanolic extract from the leaves of Laurus nobilis (bay leaf, laurel) was found to inhibit nitric oxide (NO) production in lipopolysaccharide (LPS)-activated mouse peritoneal macrophages. Through bioassay-guided separation, fourteen known sesquiterpenes were isolated from the active fraction and were examined for ability to inhibit the NO production. Seven sesquiterpene lactones (costunolide, dehydrocostus lactone, eremanthine, zaluzanin C, magnolialide, santamarine and spirafolide) potently inhibited LPS-induced NO production (IC50 = 1.2 approximately 3.8 microM). Other sesquiterpene constituents also showed the inhibitory activity (IC50 > or = 21 microM), but their inhibitory activities were less than those of sesquiterpene lactones. Alpha-methylene-gamma-butyrolactone also showed inhibitory activity (IC50 = 9.6 microM), while mokko lactone and watsonol A etc., reductants of the alpha-methylene-gamma-butyrolactone moiety by NaBH4 or DIBAL, and a 2-mercaptoethanol adduct of dehydrocostus lactone showed little activity (IC50 > or = 18 microM). These results indicated that the alpha-methylene-gamma-butyrolactone moiety is important for the activity. Furthermore, costunolide and dehydrocostus lactone inhibited inducible nitric oxide synthase (iNOS) induction in accordance with induction of heat shock protein 72 (HSP 72). These results suggested that, as one of their mechanisms of action, sesquiterpene lactones induce HSP 72 thereby preventing nuclear factor-kappaB activation followed by iNOS induction.
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PMID:Inhibitory effects of sesquiterpenes from bay leaf on nitric oxide production in lipopolysaccharide-activated macrophages: structure requirement and role of heat shock protein induction. 1083 99


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