Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: DrugBank:BIOD00017 (IFN-gamma)
 28,919 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The killing of Entamoeba histolytica trophozoites by phagocytes involves oxidative and nonoxidative mediators. In this study, we determine whether L-arginine-derived nitric oxide (NO) is involved in the killing of E. histolytica trophozoites by activated murine macrophages in vitro. Elicited peritoneal and bone marrow-derived macrophages activated with IFN-gamma alone or with IFN-gamma and LPS killed 62 to 73% of amebae, concomitant with increased levels of nitrate (NO2). Depletion of L-arginine by addition of arginase to culture medium abrogated macrophage amebicidal activity. NG-monomethyl L-arginine, an L-arginine analog, competitively inhibited NO2 release and amebicidal activity in a dose-dependent fashion, without affecting H2O2 production; however, the addition of excess L-arginine competitively restored macrophage amebicidal effects. In culture, sodium nitrite and sodium nitroprusside were cytotoxic to E. histolytica and this was reversed by the addition of myoglobin. Exogenously added FeSO4 prevented macrophage cytotoxicity. Addition of superoxide dismutase, a scavenger of O2-, partially inhibited amebicidal activity, without influencing NO2 production. Untreated and LPS-exposed macrophages produced high levels of H2O2 independent from NO2 production and amebicidal effects. However, the addition of catalase, a scavenger of H2O2, inhibited both amebicidal activity and NO2 production by activated macrophages. Our results demonstrate that NO is the major cytotoxic molecule released by activated macrophages for the in vitro cytotoxicity of E. histolytica and that O2- and H2O2 may be cofactors for the NO effector molecule.
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PMID:Macrophage cytotoxicity against Entamoeba histolytica trophozoites is mediated by nitric oxide from L-arginine. 131 38

The importance of serum-free medium components on the growth of Chinese hamster ovary (CHO) cells and production of recombinant human interferon(IFN)-gamma was investigated. The complexity of the medium led to the adoption of a statistical optimization approach based on a Plackett-Burman design. From this analysis a set of nutritional components was identified as important for cell growth and recombinant protein production. Glycine was identified as an important determinant of specific growth rate, whereas for cell production bovine serum albumin (BSA), phenylalanine and tyrosine were also identified as important. BSA, sodium pyruvate, glutamate, methionine, proline, histidine, hydroxyproline, tyrosine and phenylalanine were shown to be important for IFN-gamma production. Other medium components, such as insulin, arginine, aspartate and serine produced an inhibitory effect on both cell growth and IFN-gamma production. The effect of the stimulatory nutrients as a whole group was tested by increasing their concentration in the medium. A significant improvement in specific cell growth rate, cell production and IFN-gamma production (up to 45%) was achieved on both shake-flask and fermentor cultures. An increase in the medium concentration of the negative variables had only a small inhibitory effect (approximately 10%) on the same parameters. Analysis of the effects of the group of stimulatory amino acids and BSA on CHO cell growth showed that the effect of the former was independent of BSA.
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PMID:Application of a statistical design to the optimization of culture medium for recombinant interferon-gamma production by Chinese hamster ovary cells. 136 13

Mouse macrophages activated by gamma interferon (IFN-gamma) and bacterial lipopolysaccharide (LPS) are highly cytotoxic for the enteric protozoan parasite Entamoeba histolytica. Herein, we show that this killing by activated macrophages is L-arginine dependent, inasmuch as it was blocked by exogenous arginase or NG-monomethyl-L-arginine. These two inhibitors had no effect on E. histolytica cytolytic activity against L929 fibroblasts. Also, macrophage killing of E. histolytica always correlated with nitrite presence in the supernatant fluids. Finally, it was shown that addition of excess iron or the reductant sodium dithionite to activated macrophages blocked their ability to kill E. histolytica. Overall, this suggests that killing of E. histolytica by activated macrophages depends on the production of reactive nitrogen intermediates which leads to critical iron loss and protozoan parasite death.
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PMID:Activated mouse macrophages kill Entamoeba histolytica trophozoites by releasing reactive nitrogen intermediates. 161 30

Endothelial cells produce nitric oxide which is considered to serve as a major source of endothelial derived relaxing factor activity. It has been demonstrated that activation of mouse brain endothelium by TNF-alpha and IFN-gamma led to accumulation of nitrite which is presumably formed by oxidation of nitric oxide. A number of studies suggest that reactive oxygen species produced by cytokine-activated cells are involved in the conversion of nitric oxide to nitrites and nitrates. We investigated whether low density lipoprotein (LDL), acting as a radical scavenger, is able to inhibit nitrite accumulation in mouse brain endothelial cell cultures and in a cell-free system in which sodium nitroprusside was used as a source of nitric oxide. A comparison of these two models indicates the active involvement of LDL in suppressing nitrite accumulation in murine endothelial cultures.
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PMID:Low density lipoprotein inhibits accumulation of nitrites in murine brain endothelial cell cultures. 163 73

The cellular receptor for the human alpha and beta interferons (IFN) was expressed, by gene transfer, in a murine hepatoma-derived cell line, BTG 9A. Injected subcutaneously into the syngeneic mouse (C57BL/6), the parental and the transfected cells grew and formed tumors which later regressed. More than half the mice bearing tumors derived from cells expressing the receptor, developed IgG antibodies capable of blocking the activity, on human cells, of human recombinant IFN-alpha B, -alpha A, -alpha D and of natural human IFN-beta, but not of recombinant IFN-gamma. Cross-reactivity of human IFN-alpha on murine and bovine cells was unaffected by these antibodies. The binding of human IFN-alpha to solubilized receptors from human lymphoid cell lines was also blocked and complexes of radiolabeled recombinant IFN-alpha A or IFN-alpha B, chemically cross-linked to their human receptor could be immunoprecipitated by the antisera. IFN alpha beta receptor protein, purified by electrophoresis in sodium dodecylsulfate, was not recognized. We conclude that the antibodies are directed against the forms of the IFN alpha beta receptor actually expressed on the membrane.
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PMID:Murine tumor cells expressing the gene for the human interferon alpha beta receptor elicit antibodies in syngeneic mice to the active form of the receptor. 182 36

We determined whether endogenously produced PGE2 can down-regulate the tumoricidal properties of macrophages by a negative feedback mechanism. Peritoneal exudate macrophages or resident peritoneal macrophages of mice were incubated in medium (control) or in medium containing IFN-gamma and LPS. Activated macrophages were highly tumoricidal against syngeneic melanoma cells and secreted high levels of PGE2. Treatment with indomethacin or diclofenac sodium (voltaren) completely inhibited the production and secretion of PGE2 but not the tumoricidal activity of activated macrophages measured either immediately after activation or 1 to 3 days thereafter. Finally, the addition of exogenous PGE2 did not alter the ability of peritoneal exudate macrophages to respond to IFN-gamma or of LPS to produce high levels of tumor cell lysis. Collectively, these results show that PGE2 produced by activated macrophages is not a down-regulator of their tumoricidal activity against adherent tumor cells.
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PMID:Prostaglandin E2 does not inhibit tumoricidal activity of mouse macrophages against adherent tumor cells. 200 91

We recently described an IL-1 inhibitor found in urine of febrile patients. It is a 26-kDa glycoprotein that acts by blocking the binding of IL-1 to its receptor. In a search for a cell source for the urinary IL-1 inhibitor, we tested three promyelocytic cell lines, H-161, AML-193, and HL-60, for their ability to produce this protein. Under normal culture conditions none of these cell lines produce detectable IL-1 inhibitory activity. The H-161 cells were treated with differentiation-inducing agents, i.e., sodium butyrate, hemin, retinoic acid, DMSO, vitamin D3, and PMA alone or in combination with IL-1 alpha, IL-2, IL-3, IL-4, IL-5, IL-6, TNF-alpha, IFN-gamma, granulocyte-CSF, macrophage-CSF, granulocyte/macrophage-CSF (GM-CSF), and Con A and tested for the production of IL-1 inhibitor. Production of IL-1 inhibitor was detected in cell supernatant, when H-161 cells were differentiated to adherent macrophage-like cells under the influence of PMA followed by a second signal provided by GM-CSF. Treatment of the other two cell lines, AML-193 and HL-60, with PMA plus GM-CSF also yielded similar IL-1 inhibitor protein. Partial purified H-161-derived IL-1 inhibitor showed specific binding to IL-1R-bearing cells and blocked the binding of IL-1 to its receptor and is thus similar to the urinary-derived molecule. We conclude the GM-CSF provides a signal to adherent macrophage-like cells to become "inhibitory macrophages" and to produce a competitive inhibitor of IL-1.
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PMID:Human granulocyte-macrophage colony-stimulating factor plus phorbol myristate acetate stimulate a promyelocytic cell line to produce an IL-1 inhibitor. 214 81

Affinity chromatography of crude human urinary proteins on either human recombinant interleukin-6 (rIL-6) or human recombinant interferon-gamma (rIFN-gamma) or anti IFN-gamma receptor (IFN-gamma-R) monoclonal antibodies (McAb) yielded the two respective soluble receptors in significant amounts. A single sequence of 30 amino acid residues was obtained by N-terminal microsequencing of the protein peak purified in tandem by affinity chromatography on an IL-6 column and reversed-phase high-performance liquid chromatography. This sequence was identical with the predicted N-terminal sequence of IL-6-R as previously reported. The purified IL-6-R retained its biological activity. It was used for the preparation of specific anti IL-6-R monoclonal antibodies. Analysis of the eluted proteins from both IFN-gamma and anti IFN-gamma-R columns by inhibition of solid-phase radioimmunoassay, enzyme-linked immunosorbent assay, sodium dodecyl sulphate-polyacrylamide gel electrophoresis and Western blotting proved the existence of soluble IFN-gamma-R in normal urine. This finding together with the already known presence of soluble TNF receptors and a soluble IL-2 receptor found both in plasma and in urine indicates that release of soluble cytokine receptors into body fluids is a general phenomenon which occurs under normal physiological conditions.
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PMID:Purification of soluble cytokine receptors from normal human urine by ligand-affinity and immunoaffinity chromatography. 214 54

Monoclonal-nonspecific suppressor factor (MNSF) is a lymphokine derived from murine T cell hybridoma. The target tissues are both LPS-stimulated B cells and Con A-stimulated T cells. Since the action of MNSF may be mediated by its binding to specific cell surface receptors, we characterized the mode of this binding. The purified MNSF was labeled with 125I, using the Bolton-Hunter reagent. The labeled MNSF bound specifically to a single class of receptor (300 receptors per cell) on mitogen-stimulated murine B cells or T cells with an affinity of 16 pM at 24 degrees C, in the presence of sodium azide. Competitive experiments showed that MNSF bound to the specific receptor and that the binding was not shared with IL2, IFN-gamma, and TNF. Various cell types were surveyed for the capacity to specifically bind 125I-MNSF. 125I-MNSF bound to MOPC-31C (a murine plasmacytoma line) and to EL4 (a murine T lymphoma line). The presence of specific binding correlates with the capacity of the cells to respond to MNSF. These data support the view that like other polypeptide hormones, the action of MNSF is mediated by specific cell surface membrane receptor protein. Identification of these receptors will provide insight into the apparently diverse activities of MNSF.
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PMID:Characterization of cell-surface receptors for monoclonal-nonspecific suppressor factor (MNSF). 220

Flavone acetic acid (FAA) is an investigational drug that augments natural killer activity, induces the genes for alpha- and gamma-interferon (IFN) and tumor necrosis factor alpha, and synergizes with recombinant interleukin 2 for the successful treatment of murine renal cancer. However, in most clinical studies of FAA only minimal immunomodulatory effects have been reported. Most of the patients in these studies have also been given sodium bicarbonate to prevent possible nephrotoxicity. The current study was performed to determine whether alkalinization had any effects on FAA-induced immune modulation and therapeutic activity in mice. The results showed that alkalinization inhibited the treatment of murine renal cancer by FAA plus recombinant interleukin 2 such that the survival rate of 84% in nonalkalinized mice was reduced to 0 in mice that were alkalinized during treatment. Alkalinization also significantly inhibited the ability of FAA to augment both splenic and hepatic natural killer activity in a dose-dependent manner. In contrast, alkalinization did not inhibit the ability of polyinosinic:polycytidylic acid and poly-L-lysine stabilized in carboxymethyl cellulose, maleic anhydride divinyl ether, or Propionibacterium acnes to augment liver-associated natural killer activity. By Northern blot analysis, it was shown that the induction of mRNA for IFN-alpha, IFN-gamma, and tumor necrosis factor alpha by FAA in the spleen cells of mice was significantly reduced in alkalinized mice. Consistent with a reduction in the FAA-induced expression of the cytokine genes, alkalinization also resulted in a significant decrease in both the peak serum concentration and duration of detectable IFN activity following FAA treatment. Increasing the dose of FAA in alkalinized mice to 300 mg/kg overcame the deleterious effects of alkalinization for treatment of murine renal cancer by FAA plus recombinant interleukin 2. These results demonstrate that the process of alkalinization inhibits the immunomodulatory and immunotherapeutic effects of FAA in mice and suggest that alkalinization might have similar deleterious effects on FAA-induced immune stimulation in human clinical trials.
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PMID:Systemic alkalinization inhibits the ability of flavone acetic acid to augment natural killer activity, induce cytokine gene expression, and synergize with interleukin 2 for the treatment of murine renal cancer. 225 33


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