Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

We established an improved non-radioactive in situ hybridization (ISH) method to detect mRNA of cytokines in cell preparations and tissues. Via this method we could demonstrate various cytokines in stimulated peripheral blood mononuclear cells (PBMC), lymphoid cell lines and human lymphoid tissues. The probes for the in situ hybridization were made by labelling cytokine-specific PCR products with digoxigenin (Dig) in a repeated PCR. This resulted in an intrinsic labelling of the probe with several Dig-UTP molecules. Incorporation of Dig-11-dUTPs was shown on ethidium bromide-stained agarose gels by a higher molecular weight of the PCR products with incorporated Dig-dUTPs when compared to control PCR products without digoxigenin. Cytospin-centrifuged cells of PHA-stimulated PBMC or lymphoid cell lines and frozen sections of various human lymphoid tissues were hybridized with the Dig-labelled cytokine probes and the hybridized probes were detected immuno-histochemically. In this way, we detected and localized cytokine mRNAs (IL-2, IL-4, IL-6, IL-8, IL-10) in PBMC, in the human T-cell line Jurkat, in the follicular lymphoma cell line DoHH2, and in human lymph nodes and tonsils. The in situ hybridization had a high sensitivity as the results correlated closely with the detection of cytokine mRNA by reverse transcriptase-PCR (RT-PCR) data from the same samples. We showed that Jurkat and DoHH2 cells produce several cytokines constitutively and that, after activation with the phorbol ester PMA, expression of several cytokine mRNAS was enhanced.
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PMID:An improved, sensitive, non-radioactive in situ hybridization method for the detection of cytokine mRNAs. 765 59

Although many cytokines have been previously implicated in graft-versus-host disease (GVHD), no study to date has comprehensively evaluated their expression over time or in different tissues affected by GVHD. Using a semi-quantitative reverse transcriptase-PCR technique and a murine model of acute GVHD, we have evaluated the expression levels of mRNA for a wide range of cytokines in spleen, gut and liver tissues at weekly intervals after bone marrow transfer. The earliest cytokine responses seen were increases in IL-2, IL-10, IFN-gamma, MIP-1 alpha and TNF-alpha in the spleen, suggesting a primarily Th1 pathway. Other cytokines (IL-1 alpha, IL-10 and MIP-1 alpha) were persistently elevated in GVHD mice, but were variable depending on the tissue. These data demonstrate that a wide range of cytokines are involved in the GVHD response and that their kinetic pattern of expression is different in various affected tissues.
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PMID:Kinetic and organ-specific patterns of cytokine expression in acute graft-versus-host disease. 765 87

BALB/c and CBA/CaH mice show discrete, genetically determined patterns of tissue responses to infection with the yeast Candida albicans. By use of a semiquantitative reverse transcriptase-polymerase chain reaction, interferon (IFN)-gamma, interleukin (IL)-6, and tumor necrosis factor (TNF)-alpha were readily demonstrated in brain tissue on days 1, 3, and 5 after infection and were present in higher concentrations in CBA/CaH than in BALB/c mice. IL-2 and -4 were detected in both strains but at different time points. Both the fungus burden and the severity of the tissue damage become established before mRNA concentrations of the cytokines increase in the lesions, and the rate of clearance of the yeast is similar in both mouse strains. The data indicate that the deterministic model, which correlates Th1 and Th2 cytokines with resistance and susceptibility, respectively, is inadequate to account for the patterns of cytokine production that develop in the infected brain after sublethal challenge.
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PMID:Cytokine mRNA in brain tissue from mice that show strain-dependent differences in the severity of lesions induced by systemic infection with Candida albicans yeast. 765 77

Using a cell sorter, CD16-CD56bright natural killer (NK) cells were sorted from decidual mononuclear cells at an early stage of pregnancy. These cells were examined by the reverse transcriptase-polymerase chain reaction (RT-PCR) method for their expression of mRNA coding for the following 12 cytokines: IL-1 beta, IL-2, IL-3, IL-4, IL-5, IL-6, granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), macrophage colony-stimulating factor (M-CSF), tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), and leukemia inhibitory factor (LIF). Although mRNA coding for every cytokine was detected in decidual mononuclear cells, mRNAs coding for only G-CSF, GM-CSF, M-CSF, TNF-alpha, IFN-gamma, and LIF were detected in CD16-CD56bright NK cells. Also, the supernatant of CD16-CD56bright NK cell cultures was found to contain G-CSF, GM-CSF, M-CSF, TNF-alpha, IFN-gamma, and LIF. These findings indicate that CD16-CD56bright NK cells produce many different cytokines and that these cytokines may play an important role in a successful pregnancy.
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PMID:Cytokine production by CD16-CD56bright natural killer cells in the human early pregnancy decidua. 768 93

Human nasal mucosal samples exposed in vitro to substance P or allergenic Ag were tested for the mRNA of IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, TNF-alpha, and IFN-gamma using specific reverse transcriptase-polymerase chain reaction assays. After the administration of substance P, at dosages ranging from 10(-6) to 10(-9) M, an enhanced expression of the mRNA for IL-1 beta, -3, -5, -6, TNF-alpha, and IFN-gamma was observed in all mucosal samples of allergic subjects and in half of the nonallergic subjects. The expression of IL-2 and IL-4 was low. Mucosal samples of allergic subjects showed an increased expression of mRNA for cytokines after administration of specific Ag, whereas no enhancement was observed in samples from nonallergic subjects. Our data suggest that substance P may regulate allergic reactions via enhanced production of certain regulatory cytokines.
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PMID:Cytokine expression after the topical administration of substance P to human nasal mucosa. The role of substance P in nasal allergy. 769 47

We have characterized the IL-8-induced signal transduction processes in T lymphocytes. A basal level of IL-8 receptor expression was shown on mixed PBL, as identified by using phycoerythrin (PE)-coupled IL-8, and this expression was increased following IL-2 stimulation. Scatchard analysis of T cells revealed competitive binding of IL-8 with a Kd of 0.55 nM, with approximately 1200 receptors per cell, on freshly isolated T cells. After 24 h in culture following purification, reverse transcriptase PCR (RT-PCR) analyses show the mRNA for only the type B IL-8R on these cultured T lymphocytes and the cell line MOLT-4. Stimulation of T lymphocytes or T cell clones with IL-8 led to generation of inositol trisphosphate and calcium flux. In addition, when T cells were prelabeled with [3H]oleic acid, IL-8 caused a long lasting, time- and dose-related increase in [3H]phosphatidylethanol (PtE), indicating activation of phospholipase D (PLD). By contrast, this IL-8-dependent PLD activity was undetectable in IL-8-stimulated neutrophils. PLD activation appeared to be downstream of protein kinase C, because several inhibitors abrogated the increase in [3H]PtE, whereas guanosine-5'-O-(3-thiotriphosphate (GTP(gamma)S) and inositol trisphosphorothioate (IP3S3) both increased the generation of [3H]PtE. Together, these results demonstrate that the IL-8RB receptor is sufficient to mediate phospholipase C (PLC) and PLD activation in T lymphocytes, but not in neutrophils, and indicate an important difference in receptor usage and signal transduction pathways between IL-8-stimulated lymphocytes and neutrophils.
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PMID:IL-8-induced signal transduction in T lymphocytes involves receptor-mediated activation of phospholipases C and D. 770 9

The effects of continuous in vitro exposure to the trichothecene, vomitoxin (VT) or another protein synthesis inhibitor, cycloheximide (CHX), on interleukin (IL) secretion and mRNA levels were evaluated in murine splenic CD4+ cells. Significant increases were seen in supernatant IL-2, IL-4 and IL-5 obtained from 7 day Concanavalin A (Con A)-stimulated CD4+ cultures containing VT concentrations of 250, 100 and 100 ng/ml, respectively, compared with controls run in the absence of VT. The effect of VT on CD4+ cell proliferation was also assessed after culturing for 3, 5 and 7 days with Con A. Although total cell numbers were not affected at day 3, cultures at day 5 with 50 or more ng VT/ml and at day 7 with 100 or more ng VT/ml had significantly lower cell numbers than controls. In addition, viable cell number was unaffected at day 3, but was significantly decreased at day 5 by VT concentrations of 12.5 ng or more ml and at day 7 by 100 or more ng VT/ml. Elevations in IL-2, IL-4 and IL-5 were also observed in 7-day Con A-stimulated CD4+ cell cultures containing CHX at 50-100, 50 and 10 ng/ml, respectively. When CD4+ cells were stimulated with Con A in the absence of inhibitors and then subjected to reverse transcriptase-polymerase chain reaction coupled with Southern analysis, maximal IL-2, IL-4 and IL-6 mRNA levels were induced at 48 hr whereas peak IL-5 mRNA was observed at 72 hr. Superinduction of IL-2 mRNAs was observed in the presence of VT at 50-100 ng/ml and CHX at 50-250 ng/ml. IL-4 and IL-5 mRNAs were superinduced by VT at 100 ng/ml and CHX at 50 ng/ml. The results suggest that VT and CHX could superinduce both interleukin secretion and mRNA transcript levels in CD4+ cell cultures and that, for VT, these effects occurred concurrently with inhibition of cell proliferation.
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PMID:Effects of vomitoxin (deoxynivalenol) and cycloheximide on IL-2, 4, 5 and 6 secretion and mRNA levels in murine CD4+ cells. 779 71

The inflammatory cytokines IFN-gamma and TNF-alpha have been demonstrated in various autoimmune diseases, and are thought to participate in the induction and pathogenesis of disease. TFN-alpha is a cytopathic cytokine that is cytotoxic for oligodendrocytes in vitro and has been implicated in the pathology of multiple sclerosis and its animal model experimental allergic encephalomyelitis (EAE). We used reverse transcriptase (RT)-PCR to study the kinetics, cellular source, and regulation of cytokine gene expression in the central nervous system (CNS) of SJL/J mice with myelin basic protein-induced EAE at different stages of the disease. The expression of CD3, IL-2, IFN-gamma, and TNF-alpha mRNA was barely detectable in the CNS of unmanipulated mice or mice that were immunized with adjuvant but showed no symptoms. These mRNAs were readily detectable in the CNS of mice during peak disease, then coordinately dropped to background levels during remission. Analysis of cells isolated from the CNS of mice with acute EAE showed that the Th1 cytokines, IL-2 and IFN-gamma, were produced by infiltrating CD4+ T cells. In contrast, TNF-alpha was predominantly transcribed by non-T mononuclear CNS cells, the majority of which were identified as microglia and macrophages by their Mac-1 phenotype. Microglia could be discriminated by their low expression of CD45. Incubation of freshly derived, adult microglia from normal, uninfiltrated, CNS with activated Th1 supernatant induced the production of TNF-alpha mRNA. Therefore, TNF-alpha is made by both CNS-resident microglia and infiltrating macrophages during EAE, and this production is tightly controlled by cytokines secreted by infiltrating CD4+ T cells.
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PMID:TNF-alpha expression by resident microglia and infiltrating leukocytes in the central nervous system of mice with experimental allergic encephalomyelitis. Regulation by Th1 cytokines. 781 94

Seven days after activation with concanavalin A and irradiated spleen cells, murine CD4+ T cells were re-stimulated with ionomycin and phorbol 12-myristate 13-acetate (PMA). IL-2 and IL-4 were determined in the supernatant. When cholera toxin, forskolin together with phosphodiesterase inhibitors or dibutyryl-cAMP were added at the time of re-stimulation, a dose-dependent increase of IL-4 and IL-5 release was noted. IL-2 was down-regulated as reported before. The up-regulation of IL-4 and the down-regulation of IL-2 correlated with an increase of IL-4 mRNA and a decrease of IL-2 mRNA as determined by semi-quantitative reverse transcriptase polymerase chain reaction. Similar results were found with prostaglandin E2 using PMA and ionomycin or plate-bound anti-CD3 antibody as re-stimulants. These results suggest that, in activated CD4+ T cells, cAMP-elevating agents induce a switch of lymphokine production towards a Th2-like phenotype through regulation at the transcriptional level. This is supported by the fact that complex formation between a synthetic nuclear factor of activated T cells (NF-AT) binding site from the IL-2 promoter and nuclear extracts was decreased when cholera toxin was added to re-activated CD4+ T cells, suggesting that cholera toxin and cAMP down-regulate IL-2 expression via decreased NF-AT binding. Finally, since IL-4 has been reported to amplify IL-4 release from activated CD4+ T cells, the autoinduction of IL-4 may very well function via cAMP.
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PMID:cAMP up-regulates IL-4 and IL-5 production from activated CD4+ T cells while decreasing IL-2 release and NF-AT induction. 781 41

The expression of the cytokine genes in normal placenta was studied using RT-PCR method capable of detecting low levels of mRNA. Total RNA was prepared from placenta of specific pathogen-free BALB/c mice at the 16th day of gestation by acid guanidinium thiocyanate-phenol-chloroform (AGPC) method. cDNA was synthesized by M-MLV reverse transcriptase, and amplified using the specific oligonucleotide primers for IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, TNF-alpha, IFN-alpha, IFN-beta and IFN-gamma by PCR method. IL-1 beta, IL-6, TNF-alpha, IFN-alpha, IFN-beta and IFN-gamma mRNA were detected in all the placentas tested. On the other hand, the expressions of IL-2, IL-3, IL-4, and IL-5 mRNA were not detected at all. These results suggest that these cytokines may play a role in the evolution of pregnancy.
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PMID:[Expression of cytokine messenger RNA in murine placenta]. 783 98


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