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)

Lyme disease refers to the multisymptomatic illness in humans which results from infection with the tick-borne spirochete Borrelia burgdorferi. The white-footed mouse is the major reservoir for B. burgdorferi and, upon infection, certain inbred mice develop symptoms similar to those reported in human disease. Sonicated preparations of washed spirochetes were found to have potent mitogenic activity when cultured with lymphocytes from naive C57BL/6, C3H/HeJ, or BALB/c mice. The activity of the B. burgdorferi sonicate was approximately fourfold greater than that of a similarly prepared Escherichia coli sonicate. Polymyxin B efficiently inhibited the mitogenic activity of the E. coli sonicate but only slightly inhibited that of the B. burgdorferi sonicate, suggesting that a lipid A-containing lipopolysaccharide was not responsible for the B. burgdorferi activity. Kinetic analysis indicated peak proliferation at 2 to 3 days of culturing, suggesting polyclonal activation. B- and T-lymphocyte depletion experiments indicated that the major cell type responding to the B. burgdorferi mitogen was the B lymphocyte. This mitogen stimulated murine B cells not only to proliferate but also to differentiate into antibody-secreting cells, as demonstrated by the production of immunoglobulin by stimulated splenocytes. Furthermore, the sonicated preparation stimulated the B-cell tumor line CH12.LX to secrete immunoglobulin in the absence of accessory cells. B. burgdorferi also stimulated interleukin-6 production in splenocyte cultures. The observation that B. burgdorferi can stimulate activation of and immunoglobulin production by normal B lymphocytes may directly reflect on the development of arthritis associated with persistent infection by this organism.
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PMID:Demonstration of a B-lymphocyte mitogen produced by the Lyme disease pathogen, Borrelia burgdorferi. 173 Apr 76

Oncogene-transformed BALB/c-3T3 fibroblasts which spontaneously or upon immune-activation with cytokines and lipopolysaccharide (LPS) generate IL-1 alpha, were tested for their tumorigenicity as well as their interaction with natural immune defense by NK cells and macrophages. Oncogene-transformed fibroblasts were weakly tumorigenic, since not all mice developed tumors despite application of high doses of tumor cells. This was independent of the immune status of the host. However, in the immunocompetent host those transformed fibroblast lines which spontaneously produced IL-1 alpha grew only transiently and then regressed. After induction of IL-1 alpha production, a decrease in the rate of tumor take was noted and the rate of regression of developing tumors was increased. Regression of IL-1-producing transformed fibroblasts was strongly reduced but not completely abolished in sublethally irradiated mice. This indicated that IL-1 production may predominantly influence T-cell-mediated defense, but some influence on non-adaptive immunity could not be excluded a priori. IL-1 production did not influence susceptibility of transformed fibroblasts towards NK cells and macrophages. However, IL-1-producing transformed fibroblasts were most potent stimulators of NK cells and macrophages, the stimulatory effect being locally restricted. In conclusion, IL-1 producing, oncogene-transformed fibroblasts which generated the cytokine constitutively or upon immune-activation, were rejected from the tumor-bearing host following initial growth. Fibroblast-induced local activation of NK cells and macrophages was shown to play some role in tumor graft rejection. The influence of IL-1 production of transformed fibroblasts on T-cell-mediated defense is addressed in the accompanying report.
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PMID:Interleukin-1 produced by tumorigenic fibroblasts influences tumor rejection. 173 13

Macrophages derived in vitro from bone marrow progenitors (bone marrow-derived macrophages, BMDMs) using either macrophage colony-stimulating factor (CSF-1) or granulocyte-macrophage colony-stimulating factor (GM-CSF) as the myelopoietic stimulus display differential functional, morphological, and mRNA phenotypes. The data presented here demonstrate further that CSF-1- and GM-CSF-derived BMDMs differ in immunologic capacity. GM-CSF-derived BMDMs, when compared to CSF-1-derived BMDMs, showed greater cytolytic activity against tumor necrosis factor alpha (TNF-alpha)-resistant, but not TNF-alpha-sensitive, tumor targets. In contrast, CSF-1-derived BMDMs produced nitrite in response to lipopolysaccharide (LPS) alone, whereas GM-CSF-derived BMDMs required interferon gamma plus LPS treatment. The two BMDM populations also showed differential sensitivities to LPS for secretion of TNF-alpha and nitrite, but the maximal inducible amounts of these factors and prostaglandin E2 were similar between the BMDM populations. Lastly, GM-CSF-derived but not CSF-1-derived BMDMs showed an L-arginine-dependent listeriacidal activity. These results show that the functional heterogeneity of CSF-1- and GM-CSF-derived macrophages is limited and appears to result largely from differences in the activational signals required by each BMDM population to elicit a given function.
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PMID:Differential immunocompetence of macrophages derived using macrophage or granulocyte-macrophage colony-stimulating factor. 174 Jun 46

Recombinant mouse interleukin 10 (IL-10) was exceedingly potent at suppressing the ability of mouse peritoneal macrophages (m phi) to release tumor necrosis factor alpha (TNF-alpha). The IC50 of IL-10 for the suppression of TNF-alpha release induced by 0.5 microgram/ml lipopolysaccharide was 0.04 +/- 0.03 U/ml, with as little as 1 U/ml suppressing TNF-alpha production by a factor of 21.4 +/- 2.5. At 10 U/ml, IL-10 markedly suppressed m phi release of reactive oxygen intermediates (ROI) (IC50 3.7 +/- 1.8 U/ml), but only weakly inhibited m phi release of reactive nitrogen intermediates (RNI). Since TNF-alpha is a T cell growth and differentiation factor, whereas ROI and RNI are known to inhibit lymphocyte function, it is possible that m phi exposed to low concentrations of IL-10 suppress lymphocytes. m phi deactivated by higher concentrations of IL-10 might be permissive for the growth of microbial pathogens and tumor cells, as TNF-alpha, ROI, and RNI are major antimicrobial and tumoricidal products of m phi. IL-10's effects on m phi overlap with but are distinct from the effects of the two previously described cytokines that suppress the function of mouse m phi, transforming growth factor beta and macrophage deactivation factor. Based on results with neutralizing antibodies, all three m phi suppressor factors appear to act independently.
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PMID:Macrophage deactivation by interleukin 10. 174 84

The L-arginine-dependent tumor cell cytotoxicity produced by activated macrophages (M phi) may be mediated either directly by production of nitric oxide (NO), or by induction of NO synthesis in the tumor cell. The influence of M phi NO synthesis on the release of soluble cytotoxic mediators was investigated in this study. The synthesis of M phi NO, measured as nitrite, was detected 6 h after lipopolysaccharide (LPS)-triggering and reached a peak level by 44 h. A concurrent decrease in M phi viability beginning at 18 h after triggering was detected during a period of 72 h in culture. Both the production of NO and loss of viability correlated with the presence of L-arginine in the incubation media and was inhibited by NG-monomethyl-L-arginine (NMA). The medium in which LPS-triggered adherent peritoneal exudate cells were incubated was examined for the presence of tumor necrosis factor (TNF), gamma interferon (IFN-gamma), and the soluble mediators that induce mitochondrial respiratory inhibition in tumor cells. All of these effector molecules were released at peak levels into the conditioned supernatants within 12 h after LPS-triggering. The peak level obtained for each effector molecule was influenced by the media in which the M phi was incubated; however, no correlation was detected between the level of cytokines produced and the synthesis of nitrite by the M phi indicating that NO synthesis has no inhibiting effect on the initial burst of cytotoxic factors released.
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PMID:Independence of the pattern of early cytokine release from autoregulation by nitric oxide. 174 44

The expression of mRNA coding for IL-1 alpha and IL-1 beta was examined in human peripheral blood monocytes (PBM) to determine if the two genes are under the same mechanisms of transcriptional control and whether or not they can be regulated independently. In response to E. coli lipopolysaccharide (LPS), PBM express approximately 10-fold more IL-1 beta-specific mRNA than IL-1 alpha. However, treatment of these cells with phorbol myristate acetate (PMA) resulted in the expression of IL-1 beta mRNA. Likewise, treatment of PBM with phorbol dibutyrate (PdBu), phorbol diacetate (PDA), or mezerein, which, similar to PMA, were able to induce the translocation of protein kinase C (PKc) to the monocyte plasma membrane, resulted in predominantly IL-1 beta mRNA expression. The inactive tumor promoter 4 alpha-phorbol didecanoate (4 alpha-PDD) did not cause the translocation of PKc or induce the expression of either form of IL-1 mRNA. Following 18 h pretreatment with PMA to downregulate PKc activity, LPS was capable of inducing the expression of both forms of IL-1 mRNA, demonstrating that at least part of the response of PBM to LPS is PKc independent. These results suggest that the activation of PKc alone is sufficient to induce a high level expression of IL-1 beta but not IL-1 alpha mRNA. Furthermore, the possibility exists that another, as yet unknown, signal transduction mechanism is involved in inducing the expression of both IL-1 alpha and IL-1 beta mRNA in response to LPS.
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PMID:Differential regulation of interleukin-1 alpha and interleukin-1 beta mRNA expression in human monocytes: evidence for protein kinase C-dependent and -independent pathways. 176 43

Combined effects of chemically synthesized lipid A analogs, the compound A-171 (acylglucosamine-4-phosphate with (R)-3-hydroxytetradecanoyl and (R)-3-hydroxytetradecanoyloxy]tetradecanoyl group at the C-2 and C-3 positions), or the compound A-172 (with (R)-3-hydroxytetradecanoyloxy]tetradecanoyl and (R)-3-tetradecanoyloxytetradecanoyl group at the C-2 and C-3 positions), and muramyl dipeptide (MDP) on antitumor activity against Meth A fibrosarcoma, were examined. Meth A fibrosarcoma cells (5 X 10(5)) were inoculated intradermally into BALB/c mice on day 0, compound A-172 and/or MDP were administered intravenously (i.v.) on day 7. Although the antitumor activity by single i.v. injection of A-172 (50 micrograms/mouse) with MDP (10 micrograms) was weaker than that of 50 micrograms of synthetic lipid A analogs (506), or 10 micrograms of bacterial lipopolysaccharide (LPS) with MDP, A-172 alone and with MDP exhibited tumor inhibition rates of 49.0 and 70.6%, respectively. When A-171 (50 micrograms) with MDP (10 micrograms) was administered i.v. twice (days 7 and 10) into mice inoculated Meth A fibrosarcoma, two of five mice caused complete tumor regression. Furthermore, L929 cell lysis by the combination of A-171, A-172 with MDP was higher than that by the analogs or MDP alone, suggesting that the lipid A analogs of monosaccharide type as well as LPS are able to enhance the production of tumor necrosis factor in the presence of MDP.
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PMID:Combined effects of synthetic lipid A analogs and muramyl dipeptide on antitumor activity against Meth A fibrosarcoma in mice. 178 74

The present study was designed to evaluate the effect of rTNF alone or in combination with other BRMs on human digestive organ cancers. Six kinds of human digestive organ cancer xenografts (esophageal, stomach, colonic, pancreatic, bile duct, and liver cancers: EC-YO, GC-YN, CC-KK, PC-HN, BDC-SN and Li-7, respectively) were transplanted in nude mice, and rTNF was administered at 10(3), 5 x 10(3), or 10(4)U/head directly into the tumor 3 times a week for 2 weeks. EC-YO was the most sensitive to rTNF, and intratumoral administration of rTNF at 10(3) U/head caused tumor regression. PC-HN, CC-KK and GC-YN were relatively sensitive to rTNF, and their growth was significantly inhibited by rTNF at 5 x 10(3) U/head, however, the tumors regrew after treatment. Li-7 and BDC-SN were resistant to rTNF. The effects of rTNF in combination with recombinant interferon-gamma (rIFN-gamma), recombinant interleukin-2 (rIL-2), or streptococcal preparation OK-432 were assessed in mice transplanted with GC-YN. All combinations of rTNF at 5 x 10(3) U/head and other BRMs were more effective than rTNF alone, and GC-YN tumors were completely regressed after treatment with a combination of rTNF and rIFN-gamma or rTNF and OK-432. However in all cases, the combination of rTNF at 10(3) U/head and any other BRM did not improve the effect. Furthermore, the adverse effects of the combinations were more serious than those of rTNF alone. TNF may still be a useful cytokine, because it can induce the regression of tumors. However, for its clinical application, a method should be developed to reduce its side effects.
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PMID:In vivo effects of human recombinant tumor necrosis factor alone and in combination with other biological response modifiers on human digestive organ cancer xenografts transplanted in nude mice. 178 97

The biological stains, methylene blue and its metabolite azure B, were evaluated as anti-tumor and anti-inflammatory agents. Azur B, administered in drinking water to tumor-bearing mice, inhibited the growth of transplanted tumors and the growth of primary tumors induced by methylcholanthrene. Inhibition of growth of primary tumors was observed only in female mice. Azure B also reduced the wet weight of carrageenin-induced granulomas in rats. Azure B, given intravenously to BCG-sensitized mice 15 minutes prior to challenge with lipopolysaccharide, decreased TNF production (to 10% of control values) and prevented death from endotoxic shock. Methylene blue decreased TNF production (to 50% of control values) but did not protect the animals from endotoxic shock. Our results suggest that some of the effects previously ascribed to methylene blue are probably mediated via its metabolite, i.e. azure B. Low toxicity and easy administration of the dyes explain their use in clinical settings.
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PMID:Anti-tumoral and anti-inflammatory effects of biological stains. 181 Jan 51

Astrocytes and microglial cells cultured from murine brain were stimulated to produce tumor necrosis factor alpha (TNF) by exposure to lipopolysaccharide (LPS). TNF alpha production began within 2 h with maximum production between 4 and 8 h after stimulation. Clinically relevant low (2 Gy), but not high (8 Gy), doses of radiation significantly increased TNF production by astrocytes and microglial cells in response to LPS. The radiation effect was even more marked with multiple 2 Gy doses. TNF is cytotoxic for oligodendrocytes and for certain tumor cells. It increases vascular permeability and enhances immune responses as well as having other biological effects. It is conceivable that production of TNF by astrocytes and microglial cells during clinical radiation therapy might influence the responses of tumor and/or normal CNS tissues.
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PMID:Radiation enhances tumor necrosis factor alpha production by murine brain cells. 181 42


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