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)

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

In human long-term marrow cultures granulomonopoiesis is maintained for several weeks. Studies on granulomonocytic progenitors (CFU-GM) and their progeny have shown that survival, proliferation, differentiation and maturation of these cells are controlled by a set of glycoproteins, the colony-stimulating factors (CSFs) and the Steel factor. We have studied the expression of these factors using reverse transcriptase polymerase chain reaction (RT-PCR) in 17 adherent layers of normal bone marrow at 3, 5 or 7 weeks of culture. We have taken the 5637 bladder carcinoma cell line as a control for expression of GM-CSF, M-CSF, G-CSF and Steel factor, and PHA-activated T lymphocytes as a control for expression of multi-CSF (interleukin 3, IL-3). We have found that GM-CSF was expressed in the 17 adherent layers without induction by interleukin 1 beta (IL-1 beta). M-CSF was also detected in all cases, but in two early-stage (week 3 and week 5) cultures only after stimulation by IL-1 beta. G-CSF was detected in only 11 cases (three without IL-1 beta, and eight after addition of IL-1 beta). Steel factor was detected in 14 cases (ten without IL-1 beta, and four after addition of IL-1 beta). IL-3 was not detected even by means of nested RT-PCR. These data indicate in six late-stage (week 5 or week 7) cultures G-CSF messenger concentrations 10(3)-fold less than in 5637 control cells (for an identical amount of total cellular RNA). A similar conclusion may be drawn for Steel factor in three late-stage cultures. For IL-3 our negative results indicate a messenger concentration 10(5)-fold less than in activated T lymphocytes. These results suggest a crucial role for GM-CSF and M-CSF in the maintenance of granulomonopoiesis in human long-term cultures. The role of G-CSF and Steel factor may be more marginal. Eventually IL-2 may not be involved in the regulatory process.
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PMID:The detection of colony-stimulating factors and steel factor in adherent layers of human long-term marrow cultures using reverse-transcriptase polymerase chain reaction. 751 Mar 57

OL-2, a highly branched (1-->3)-beta-D-glucan, is an antitumor glucan showing strong hematopoietic activity with weaker adjuvant activity than schizophyllan (SPG), another antitumor glucan and one which is used clinically. This paper deals with the gene expression of cytokines in mice by OL-2 and SPG in order to characterize their immunopharmacological activity. Gene expression was examined by a reverse transcriptase-polymerase chain reaction method after intraperitoneal administration of OL-2 or SPG (250 micrograms/mouse). The OL-2 administered mice strongly expressed the interleukin 1 receptor antagonist (IL-1ra) gene but SPG administered mice did not. The difference would be strongly related to the antigen-specific response between OL-2 and SPG. In the genes related to haematopoiesis, OL-2 induced G-CSF and GM-CSF, but SPG induced IL-3. These differences would relate to the pattern of haematopoietic response. Comparing the cytokine gene expression in ICR and AKR mice by OL-2 administration, the changes in cytokine gene expression were less in AKR mice administered OL-2. These findings suggest that the immunopharmacological characteristics of OL-2 are closely related, at least in part, to the activation of the complement system. The data shown in this paper also suggest that cytokine gene expression by beta-glucan would be significantly affected by the structure of these glucans.
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PMID:Analysis of cytokine mRNAs induced by the administration of a highly branched (1-->3)-beta-D-glucan, OL-2. 800 Mar 84

Disparate findings have been reported as to whether human immunodeficiency virus (HIV) affects cytokine production by macrophages (MA). We investigated production of different cytokines and of macrophage inflammatory protein (MIP)-1alpha by HIV-1Ba-L- or HIV-1Ada-infected blood-derived MA. Relative to controls, only MIP-1alpha levels increased twofold to > 10-fold in supernatants 2 to 3 weeks postinfection (PI), at the time of maximum virus production; levels of the other chemokines (RANTES, interleukin (IL)-8) and cytokines (IL-1alpha, IL-3, IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF), G-CSF, tumor necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta1) investigated were not affected. MIP-1alpha mRNA signal assessed by reverse transcriptase-polymerase chain reaction (RT-PCR) was, however, only occasionally greater in cells from infected cultures relative to controls. MIP-1alpha levels in supernatants remained in the same range as in control cultures when more than 10 mmol/L Zidovudine was added 24 hours PI, which indicates involvement of virus replication in the effect. Anti-MIP-1alpha antibody labeling identified a 10% to 25% subset of MA, strongly expressing HLA-DR and CD4, and also stained by anti-IL-6 and anti-TNF-alpha antibodies. Two weeks PI, dual staining showed that the majority of the 5% to 20% cells that were p24+ belonged to the MIP-1alpha+ population, which may define a MA subset capable to better sustain HIV replication. MIP-1alpha induced by HIV replication in MA might play a role in the pathophysiology of HIV infection; in impaired hematopoiesis; or as a CD4+ and CD8+ lymphocyte chemoattractant, by recruiting either or both HIV-susceptible and cytotoxic T lymphocytes to virus replication sites.
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PMID:Macrophage inflammatory protein-1alpha is induced by human immunodeficiency virus infection of monocyte-derived macrophages. 863 52

Restoration of bone marrow and immune function by means of allogeneic bone marrow transplantation has been attempted in AIDS patients but has not been successful as the donor-derived cells, or their progeny, inevitably became infected. A hairpin ribozyme that specifically cleaves HIV-1 RNA has been developed by F. Wong-Staal et al. and has been demonstrated to confer resistance against HIV-1 infection. Allogeneic transplantation of CD34+ cells or their pluripotent subsets, transduced by vectors bearing this ribozyme gene, can protect the stem cells and their progeny from HIV-1 infection and eventually restores immune function. We have provided evidence that long-term repopulating stem cells can be mobilized into peripheral blood by growth factors. The combination of G-CSF and GM-CSF seems to yield a high frequency of pluripotent stem cells with a CD34+ subset profile that is similar to placental and umbilical cord blood (PUCB). We have then demonstrated a highly efficient transduction of CD34+ cells from PUCB and mobilized leukapheresis products by retroviral vectors bearing the ribozyme gene. Expression of the ribozyme gene, as shown by reverse transcriptase-polymerase chain reaction, was of similar magnitude (70%-90% of cells that grow into colonies). Challenge of the progeny macrophages from such transduced CD34+ cells with monocyte-trophic strains of HIV-1 showed that they were resistant to infection. Thus allogeneic transplantation of CD34+ cells or their pluripotent subsets, transduced with ribozyme gene, can be a promising strategy for the treatment of HIV infection.
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PMID:Stem cells as vehicles for gene therapy: novel strategy for HIV infection. 874 96

The present study demonstrated that a human B-cell line derived from non-Hodgkin's lymphoma. HCF-MLpN. constitutively expressed G-CSF receptor on the cell surface. G-CSF binding to the cell surface was shown by immunofluorescence staining using biotinylated G-CSF preparation and analysed by flow cytometry. Specific binding of G-CSF to the cells was shown by pretreatment with unlabelled G-CSF. In the radioreceptor assay and Scatchard plot analysis using radiolabelled ligand, MLpN cells revealed a single species of binding site with an equilibrium dissociation constant of 167 (153-182) pM and a maximal binding site per cell of 1076 (1044-1116). The G-CSF receptor mRNA transcript was exhibited in the RNA from MLpN cells by reverse transcriptase polymerase chain reaction procedure. [3H]thymidine incorporation and trypan blue exclusion showed that the G-CSF receptor was capable of transducing the growth signal to HCF-MLpN cells. A small fraction of fresh B blasts from six patients with B-cell lymphoma and leukaemia displayed G-CSF binding by two-colour immunofluorescence staining. In contrast, a panel of seven B-cell lines was negative for the binding to biotinylated G-CSF preparation. These results suggest that the phenotype of G-CSF binding may be lost during the culture. The expression of G-CSF receptor in HCF-MLpN cells appeared to be exceptional.
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PMID:Constitutive expression of granulocyte-colony stimulating factor receptor on a human B-lymphoblastoid cell line. 875 83

The in vivo effect of G-CSF on the maturation of mouse bone marrow megakaryocytes was studied by monitoring the DNA contents. Megakaryocytes were first identified by a specific 1C2 monoclonal antibody against mouse platelets and megakaryocytes and DNA contents of these cells were measured by propidium iodine. Megakaryocytes of mice transgenic for human G-CSF had a modal DNA class of 8N, showing a striking contrast to the previous reports that normal mouse megakaryocytes from most strains have 16N DNA content as a modal class. Daily 10 micrograms administration of G-CSF to mice for three to five days affected the DNA distribution pattern of bone marrow megakaryocytes, with a higher proportion of cells having 8N DNA contents. This G-CSF treatment, however, did not influence the peripheral blood platelet count or bone marrow megakaryocyte number. Administration of G-CSF along with thrombopoietin (TPO) reduced the proportion of megakaryocytes, with 32N DNA, the DNA class that was increased by TPO. Finally, the presence of mRNA for the mouse G-CSF receptor was demonstrated in two megakaryoblastic cell lines by reverse transcriptase polymerase chain reaction. These results indicated that G-CSF may have a suppressive effect on the maturation of mouse bone marrow megakaryocytes when monitored by the DNA polyploidy. Although further study is clearly necessary, the presence of mRNA for the G-CSF receptor in megakaryocytic lineage strongly suggests the direct action of G-CSF on this cell lineage.
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PMID:Overexpression of granulocyte colony-stimulating factor in vivo decreases the level of polyploidization of mouse bone marrow megakaryocytes. 882 Sep 58

Acute myeloid leukemia (AML) blast cells frequently produce interleukin-6 (IL-6) and other cytokines such as colony-stimulating factors (CSF: G-CSF, M-CSF, and GM-CSF), tumor necrosis factor (TNF)-alpha, and IL-1. The AML blast cells that produced IL-6 alone could not form autonomous in vitro colonies, whereas the blast cells that coexpressed CSF in addition to IL-6 were able to form such colonies. This suggests that IL-6 acts as a costimulator to enhance CSF-induced clonogenicity of AML blast cells. TNF-alpha and IL-1 that are produced from the blast cells may stimulate the growth of the AML blast cells by inducing production of CSF in bone marrow stromal cells or in the blast cell population itself. Improvement of clinical manifestations by the administration of an anti-IL-6 murine monoclonal antibody in a patient with AML-M5B confirmed an important role of IL-6 in in-vivo growth of the blast cells. The mRNA expression of IL-6 and its related genes in AML and acute lymphoid leukemia (ALL) blast cells was analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR). IL-6 mRNA expression was common in AML, but rare in ALL, whereas the IL-6 receptor (IL-6R) mRNA was expressed in almost all cases of AML and in more than half of the cases of ALL. In contrast, gp130 was ubiquitously expressed in both AML and ALL. A significant correlation between the levels of IL-6R expression and the responsiveness of the blast cells to exogenous IL-6 was observed. This suggests the possibility of the rapid prediction of the responsiveness of leukemic cells to exogenous IL-6 (IL-6 administration for therapy) by rapid measurement of IL-6R mRNA by RT-PCR.
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PMID:The expression of IL-6 and its related genes in acute leukemia. 890 69

Receptors for granulocyte colony-stimulating factor (G-CSFRs) have been confirmed on the cell surfaces of several non-haematopoietic cell types, including bladder cancer cells. This observation has naturally led to the hypothesis that the expression of G-CSFR on these cells may enhance their growth by G-CSF. In this study, the expression of G-CSFR was determined in both established human bladder cancer cell lines and primary bladder cancers. We studied five different human bladder cancer cell lines (KU-1, KU-7, T-24, NBT-2 and KK) and 26 newly diagnosed bladder tumours. G-CSFR mRNA expressions on cultured cell lines were determined using the reverse transcriptase polymerase chain reaction (RT-PCR) method. Furthermore, the G-CSFR binding experiments on the cultured cell lines were conducted using the Na(125)I-labelled G-CSF ligand-binding assay method. Moreover, the G-CSFR mRNA expressions on primary bladder tumour specimens were assessed using the in situ RT-PCR method. Three out of the five cultured cell lines (KU-1, NBT-2 and KK) exhibited G-CSFR mRNA signals when the RT-PCR method was used. The G-CSFR binding experiments showed an equilibrium dissociation constant (K[d]) of 490 pM for KU-1, 340 pM for NBT-2 and 103 pM for KK cells. With in situ RT-PCR, the tumour cells of 6 out of 26 primary bladder tumour specimens (23.1%) presented positive G-CSFR mRNA signals. Thus, in this study, G-CSFR expression was frequently observed on bladder cancer cells. Therefore, the clinical use of G-CSF for patients with bladder cancer should be selected with great care.
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PMID:Granulocyte colony-stimulating factor receptor expression on human transitional cell carcinoma of the bladder. 916 42

Point mutations in the gene for the G-CSF receptor have been reported previously in a subgroup of patients with severe congenital neutropenia. Here, we investigated the frequency of these specific G-CSF receptor mutations in patients with neutropenic disorders undergoing treatment with recombinant human (r-metHu)G-CSF (Filgrastim). Nucleotides 2306 to 2561, including the critical region (nucleotides 2384-2429) from the intracellular domain of the G-CSF receptor gene, were amplified by reverse transcriptase-polymerase chain reaction, and DNA was sequenced directly and after transformation in E. coli. Four of 30 patients with severe congenital neutropenia displayed a point mutation in the tested cytoplasmic region of the G-CSF receptor gene. Two of the four patients with a mutated G-CSF receptor developed acute myeloid leukemia secondary to congenital neutropenia. G-CSF receptor analyses were performed in myeloid cells taken at different time points in the four patients with the mutated receptor, and no correlation between occurrence of the mutation and time or dose of r-metHuG-CSF treatment was found. No point mutations in the G-CSF receptor critical domain could be detected in cells from the other 26 congenital neutropenia patients. Additionally, no G-CSF receptor point mutations could be seen in neutrophils, blood and bone marrow mononuclear cells from patients with cyclic or idiopathic neutropenia, and bone marrow mononuclear cells from patients suffering from severe aplastic anemia. Similar results were obtained by Touw et al., demonstrating that five out of 25 patients with congenital neutropenia reveal G-CSF receptor mutations. These data show that the point mutations in the critical region of the intracellular part of the G-CSF receptor occur only in a subgroup of severe congenital neutropenia patients. Furthermore, our data suggest that the described G-CSF receptor point mutations are not correlated with the start, duration or doses of r-metHuG-CSF treatment, but might result from genetic instability in the G-CSF receptor gene in severe congenital neutropenia.
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PMID:Frequency of point mutations in the gene for the G-CSF receptor in patients with chronic neutropenia undergoing G-CSF therapy. 936 31


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