Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Promonocytic cells U937 with previously established HIV-1 persistent infection, were treated with increasing doses of the recombinant INF-alpha 2. This resulted in a significant decrease of virion-associated reverse transcriptase levels in medium of the cultures studied, most pronounced by the highest interferon doses, but depending on this cytokine presence. In spite of the marked restrictive effect of the interferon on the infectious virus production the synthesis, of viral structural proteins by the U937 cells, as detected by immunofluorescence, was not affected. The therapeutic index of interferon was considerably high.
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PMID:Recombinant interferon-alpha 2 inhibits HIV replication in chronically infected promonocytic cells. 127 64

The "stromal" or adherent cells of long-term murine Dexter explant bone marrow cultures provide the best in vitro model of the bone marrow microenvironment. Colony-stimulating factor-1 (CSF-1) is produced constitutively by these cells and is easily detected, but most investigators have not found constitutive production of the other hemolymphopoietic cytokines. We have previously reported the detection of granulocyte-macrophage-CSF (GM-CSF) in murine stromal cultures and its induction by the lectin Pokeweed mitogen. The present studies analyzing stromal cytokine messenger RNA (mRNA) production by standard Northern blot analysis show constitutive production of mRNAs for CSF-1, GM-CSF, granulocyte-CSF (G-CSF), c-kit ligand (KL), and interleukin-6 (IL-6), but not IL-3, IL-4, or IL-5 by 3-week irradiated or nonirradiated murine Dexter stromal cells. Exposure of stromal cells to Pokeweed mitogen or IL-1 16 hours before RNA harvest induces the messages for GM-CSF, G-CSF, KL, and IL-6, but not IL-3, IL-4, IL-5, or CSF-1. Polymerase chain reaction amplification of cDNA made with reverse transcriptase from stromal RNA using two separate sets of IL-3-specific primers shows the presence of IL-3 message in irradiated stromal cells, which is only detectable with this more sensitive technique. The factor-dependent cell lines FDC-P1 and 32D are supported by the stromal cells without the addition of exogenous growth factors, demonstrating a cytokine activity in these cultures that is inhibited by the addition of anti-IL-3 or anti-GM-CSF antibodies. These data indicate that murine Dexter stromal cells constitutively produce CSF-1, GM-CSF, G-CSF, IL-6, KL, and IL-3. This growth factor production could explain the support of granulocyte, macrophage, and megakaryocyte production and stem cell maintenance in Dexter-type long-term murine bone marrow cultures.
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PMID:Biologic significance of constitutive and subliminal growth factor production by bone marrow stroma. 137 43

Mouse bone marrow and fetal liver stromal clones have been analyzed for their cytokine mRNA expression. The reverse transcriptase polymerase chain reaction (RT-PCR) has allowed us to detect interleukin (IL) mRNA levels, even if synthesized at levels not detectable by Northern blot analysis. We found that stromal cells possess the potential to constitutively express a much larger number of interleukins than previously described. The three stromal clones analyzed here expressed mRNA for IL3 and IL2, in addition to mRNA for IL1, IL4, IL6, and IL7. None of the stromal clones synthesized IL5 mRNA. Cytokine mRNA synthesis by stromal cells was found to be subjected to negative and positive regulation by interleukins. IL2, IL3, IL6, and IL7 gene expression was much more sensitive to cytokine regulation than that of IL1 and IL4.
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PMID:Interleukin (IL1 to IL7) gene expression in fetal liver and bone marrow stromal clones: cytokine-mediated positive and negative regulation. 138 Apr 62

After allergen application to skin, there is enhanced class II major histocompatibility complex antigen expression, as well as enhanced T-cell-stimulatory function by epidermal Langerhans cells (LC). In this study, we investigated the early changes in the epidermal cytokine profile using a sensitive reverse transcriptase PCR technique to determine whether cytokines may be related to LC activation. We found that, on the mRNA and protein level, changes in the epidermal cytokine pattern caused by allergens in the induction phase of contact sensitivity are distinct from those caused by irritants or tolerogens. The earliest of the changes is the LC-derived interleukin (IL) 1 beta mRNA signal strength that is increased within 15 min of allergen painting.
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PMID:Early events in the induction phase of contact sensitivity. 138 42

Epidermal Langerhans cells (LC) are considered direct yet immature precursors of dendritic cells (DC) in the draining lymph nodes. Although the development of LC into potent immunostimulatory DC occurs in vitro and has been studied in detail, little is known about their profile of cytokine gene expression. By using reverse transcriptase polymerase chain reaction analysis to screen 16 cytokines followed by Northern blotting for selected analysis, we determined the cytokine gene expression profile of murine LC at different time points in culture when T cell stimulatory activity is increasing profoundly. LC regularly expressed macrophage inflammatory proteins, MIP-1 alpha and MIP-2, and interleukin 1 beta (IL-1 beta). Both MIPs were downregulated upon culture and maturation into DC, whereas IL-1 beta was strongly upregulated in culture. MIP-1 alpha and IL-1 beta mRNA were found only in LC, but not in other epidermal cells. Apart from trace amounts of IL-6 in cultured LC, several macrophage and T cell products were not detected. The cytokine expression profile of LC thus appears distinct from typical macrophages. The exact role of the cytokine genes we found transcribed in LC remains to be determined.
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PMID:Cytokine gene expression in murine epidermal cell suspensions: interleukin 1 beta and macrophage inflammatory protein 1 alpha are selectively expressed in Langerhans cells but are differentially regulated in culture. 140 64

Epidermal cells (EC) are a rich source of cytokines that can regulate the function of cells in skin and in other tissues. To organize the array of data pertaining to cytokine expression by EC subpopulations, we have tabulated such data according to cell source, state of cell activation, and type of assay employed. This information forms a background for our own studies, in which reverse transcriptase-polymerase chain reaction (RT-PCR) was used to show that Langerhans cells (LC) are the principal source of mRNA for interleukin 1 beta and macrophage inflammatory protein-1 alpha (MIP-1 alpha) among unstimulated mouse EC.
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PMID:Cytokine expression by epidermal cell subpopulations. 143 Dec 7

NF kappa B is a potent mediator of specific gene expression in human monocytes and has been shown to play a role in transcription of the HIV-1 genome in promonocytic leukemias. There is little information available on the response of NF kappa B to cytokines in normal human monocytes. We have used a 32P-labeled oligonucleotide derived from human immunodeficiency virus (HIV-1) long terminal repeat, which contains a tandem repeat of the NF kappa B binding sequence, as a probe in a gel retardation assay to study this transcription factor. Using this assay, we have detected NF kappa B in extracts of nuclei from normal human monocytes. Treatment of normal monocytes with 12-0-tetradecanoyl phorbol-13-acetate (TPA) for 4-24 h caused the complete disappearance of NF kappa B from nuclear extracts of monocytes. A similar result was obtained with the mature monocytic leukemia cell line THP-1. The constitutive transcription factor SP1 was unaffected by addition of TPA. The disappearance of NF kappa B from the nucleus was concentration dependent between 10 and 50 ng/ml of phorbol ester. In THP-1 cells, TPA also induced a new, faster-migrating NF kappa B species not induced in monocytes. Protein kinase C inhibitor staurosporine, but not cyclic nucleotide-dependent protein kinase inhibitor HA-1004, also dramatically reduced constitutive levels of nuclear NF kappa B. Finally, TPA addition to monocytes infected with HIV-1 inhibited HIV-1 replication, as determined by reverse transcriptase assays, in a concentration-dependent manner. These results are in striking contrast to the increase in nuclear NF kappa B and HIV-1 replication induced by phorbol esters in promonocytic leukemia cells U937 and HL-60, and emphasize the importance of studying cytokine regulation of HIV-1 in normal monocytes.
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PMID:Phorbol ester reduces constitutive nuclear NF kappa B and inhibits HIV-1 production in mature human monocytic cells. 146 36

Uterine stromal (USC) and uterine epithelial (UEC) cells were isolated from immature and mature mice to determine their ability to secrete interleukin-6 (IL-6) in response to ovarian steroids, IL-1 alpha, and soluble products produced by the heterologous cell type. In addition, the effect of IL-6 on embryo attachment and outgrowth in vitro was determined. UEC cultured on nitrocellulose filter inserts in a polarized manner secreted IL-6 with a 2.5- to 5-fold apical vs. basal preference, as determined by a B9 hybridoma cell proliferation assay and enzyme-linked immunosorbent assay. The hormonal status of animals at the time uteri were removed did not influence subsequent secretion of IL-6, as UEC isolated from immature, diestrous, and estrous stage mice exhibited both a similar amount and had a similar apical preference for secretion of IL-6. The addition of 17 beta-estradiol (E) to UEC cultures markedly inhibited total IL-6 secretion, but did not affect vectorial secretion. The inhibitory effect of E on IL-6 secretion by UEC was consistent with an apparent decrease in IL-6 transcript observed by a reverse transcriptase polymerase chain reaction assay. Other transcripts detected by this assay in UEC included IL-1 alpha, but not IL-1 beta or tumor necrosis factor-alpha. Secretion of IL-6 by UEC was not stimulated by IL-1 alpha, conditioned medium from USC, or coculture with USC. USC secreted IL-6, and while this also was inhibited by E, progesterone was more effective in this regard at physiological concentrations. In addition, there was a synergistic effect of E plus progesterone on inhibition of IL-6 secretion by USC. Secretion of IL-6 by USC was stimulated by IL-1 alpha, and coculture studies demonstrated the ability of UEC to stimulate a several-fold increase in IL-6 secretion by USC. The cytokine transcripts detected in USC cultures included IL-6 and IL-1 alpha, but not IL-1 beta. Transcripts for tumor necrosis factor-alpha were present in USC only after culture with IL-1 alpha. IL-6 added to blastocysts on laminin-coated tissue culture wells resulted in a transient inhibition of the rate of blastocyst attachment and, to a greater extent, an inhibition of the rate of embryo outgrowth. In addition, IL-6 inhibited the size of embryo outgrowths at 24 and 48 h of culture.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Secretion and hormonal regulation of interleukin-6 production by mouse uterine stromal and polarized epithelial cells cultured in vitro. 150 48

Experimental autoimmune encephalomyelitis (EAE) serves as an important animal model for understanding the events that lead to immune-mediated inflammation and tissue destruction within the central nervous system. We have utilized a murine adoptive transfer model of EAE and semiquantitative reverse transcriptase-polymerase chain reaction analysis to examine cytokine mRNA expression within the central nervous system in relation to the onset and resolution of paralysis associated with EAE. Spinal cord samples, obtained from mice as they progressed through discrete clinical stages of EAE, were examined for the expression of six cytokine genes (IL-1 alpha, IL-2, IL-4, IL-6, IL-10, and IFN-gamma). Distinct patterns of cytokine gene expression were observed during the acute, recovery, and chronic phases of EAE. The acute phase of disease was characterized by rapid increases in the levels of mRNA for IL-2, IL-4, IL-6, IFN-gamma, and IL-1 alpha. In fact, peak expression of several cytokine mRNA (e.g., IL-2, IL-4, IL-6, and IFN-gamma) occurred before the peak in clinical severity. In contrast, IL-1 alpha mRNA levels were elevated throughout the initial disease course. IL-10 mRNA demonstrated only modest increases during the acute phase of EAE. Stabilization of the clinical symptoms was characterized by rapid declines in the mRNA levels of IL-2, IL-4, IL-6, and IFN-gamma. The decreases in these four cytokine mRNA levels occurred concomitant with a dramatic rise in IL-10 mRNA. Finally, of the six cytokine mRNA examined, only IL-1 alpha, IFN-gamma, and IL-10 mRNA remained elevated during the early chronic stage. These results suggest that local cytokine production varies significantly during the course of EAE and that increases in discrete sets of cytokines are associated with the acute response and the recovery/chronic phase of disease.
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PMID:Analysis of cytokine mRNA expression in the central nervous system of mice with experimental autoimmune encephalomyelitis reveals that IL-10 mRNA expression correlates with recovery. 152 89

Thuja polysaccharide g fraction (TPSg) was shown to be an inducer of the CD4+ fraction of the human peripheral blood T-cell subset (1,2). Furthermore, it could be demonstrated that TPSg is a potent inhibitor of the expression of HIV-1-specific antigens and of the HIV-1-specific reverse transcriptase (3). This report deals with the cytokine pattern induced by TPSg in human peripheral blood lymphocyte (PBL) and purified monocyte/macrophage cultures. In addition, a further characterization of the CD4+ T-cell fraction stimulated by TPSg was performed by FACS analysis. TPSg is induces IL-1 beta, IL-2, IL-3, IL-6, gamma-IFN, G-CSF, GM-CSF, and TNF-beta production in PBL cultures; and IL-1 beta and IL-6 in monocyte/macrophage cultures. Enzyme-linked immunosorbent assays (ELISAs) demonstrated that no IL-4 was produced by PBL cultures under TPSg influence.
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PMID:Mitogenic activity of high molecular polysaccharide fractions isolated from the cuppressaceae Thuja occidentalis L. enhanced cytokine-production by thyapolysaccharide, g-fraction (TPSg). 160 22


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