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)

Papaverine hydrochloride (PAP) has previously been shown to have a potent inhibitory effect on the replication of viruses such as cytomegalovirus (CMV) and measles. In this report the effect of PAP on human immunodeficiency virus (HIV) replication and T lymphocyte cell function were examined. MT4 cells infected with HIV strain 3b were incubated with serial dilutions of PAP (1-30 microM). At selected times postinfection HIV replication was measured by reverse transcriptase activity (RT) or HIV p24 Ag. PAP significantly inhibited HIV replication by more than 99% at doses of 30 microM with an CD50 and ED50 of 32 microM and 5.8 microM respectively. The mechanism of inhibition of HIV caused by PAP appeared independent form its ability to increase intracellular levels of cAMP and was not mediated via a direct effect on RT activity. To examine T cell function, peripheral blood mononuclear cells (PBMC) from normal donors were stimulated with phytohemagglutinin (PHA) or CMV Ag in the presence or absence of PAP (1-30 microM). At selected times proliferative response to PHA and CMV Ag were determined by [3H]thymidine uptake. In addition, interferon (IFN) gamma and interleukin 2 (IL2) response to mitogens were measured by radioimmunoassay (RIA). PAP enhanced PHA induced IFN production at doses of 1-10 microM and CMV Ag induced IFN production at doses of 1-3 microM. Higher doses were inhibitory. PAP did not affect IL-2 production or IL2 receptor expression and had an inhibitory effect on mitogenic responses.
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PMID:Papaverine hydrochloride: effects on HIV replication and T-lymphocyte cell function. 750 1

Human tumors can constitutively express cytokines and growth factors, but the extent of this expression has not been investigated. Using 44 different probes to cytokines, growth factors, and their receptors, we tested 21 melanoma and 5 melanocyte cultures for RNA transcript expression by reverse transcriptase-polymerase chain reaction. With 30 amplification cycles, expression of the cytokines interleukin (IL)-1 beta, IL-6, leukemia inhibitory factor (LIF), IL-7, gro alpha, IL-8 and the p35 chain of IL-12 was detected in more than 60% of melanomas. Concomitant receptors for IL-6 and IL-7 were also detected. IL-1 alpha, IL-5, Rantes, IL-10, interferon (IFN)-beta, tumor-necrosis factor (TNF)-alpha, G-colony-stimulating factor (CSF) and GM-CSF were expressed at lower levels. Melanocytes showed greatly reduced cytokine RNA transcripts, and only gro alpha was consistently detected. No expression of IL-2, IL-3, IL-4, IL-9, the p40 chain of IL-12, IFN-alpha or IFN-gamma RNA transcripts was detected in melanomas or melanocytes. The growth factors expressed by melanomas and, after further signal amplification, by melanocytes were transforming growth factor (TGF)-alpha, epidermal growth factor (EGF), TGF-beta, endothelial-cell growth factor (ECGF), basic-fibroblast growth factor (bFGF), nerve growth factor (NGF) and steel. The receptors EGFR, FGFR, NGFRp70 and c-kit were also expressed by melanomas and melanocytes. These results point to new possible autocrine and paracrine pathways in melanoma biology.
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PMID:Expression of cytokine/growth factors and their receptors in human melanoma and melanocytes. 750 78

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

The expression of the cytokine genes was studied under physiological conditions in normal adult mice using RT-PCR method capable of detecting low levels of mRNA. Total RNA was prepared from brain, spinal cord, lung, spleen, liver and kidney of 6 to 8 week-old specific pathogen-free BALB/c mice 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. Although IL-1 mRNA was detected in all the organs, IL-3 mRNA was not detected in any organs tested. IL-2 or IL-4 mRNA and IL-5 mRNA were produced only in spleen and lung, respectively. However, IL-6, TNF-alpha and IFN mRNA were detected in some different organs. These results suggest that many kinds of cytokine mRNA were produced in vivo under physiological conditions in normal mice.
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PMID:[Expression of cytokine messenger RNA in mice in physiological conditions]. 751 36

The induction of the cytokine mRNA after infection with Herpes simplex virus (HSV) was studied using RT-PCR method capable of detecting low levels of mRNA. Total RNA was prepared from spleen lymphocytes 3 h after infection with HSV-1 (+GC virulent variant and -GCr attenuated variant of Miyama strain) 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. After HSV-1 infection, IFN-alpha, IFN-beta, IFN-gamma, IL-1 beta, IL-4, IL-6 and TNF-alpha mRNA were significantly induced, but IL-2, IL-3 and IL-5 mRNA were not induced. Although IFN-alpha, IFN-gamma and IL-6 mRNA were more strongly induced by infection with +GC virulent variant than -GCr attenuated variant, there was no significant difference in the expression of other cytokine mRNA between two variants. These results demonstrate that cytokine mRNA in addition to IFN was induced by HSV infection, and suggest that cytokines as well as IFNs may play a role in the defense mechanism against HSV infection.
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PMID:[Induction of messenger RNA of cytokines by Herpes simplex virus infection in mice]. 751 38

We have established an IL-2 independent malignant lymphoma line (CM-1) from peripheral T lymphocytes donated by a female patient with nervous system disease, the biological characteristics of CM-1 cells was studied in this paper. Another T lymphocytes, such as peripheral T lymphocytes donated by a male patient with multiple sclerosis, could be transformed into a malignant lymphoma line by using filtered supernatant of the CM-1 cultured medium, thus the CM-2 cell line was established. The CM-1 and CM-2 cells were transplanted by subcutaneous inoculation into nude mice, and could cause the occurrence of typical malignant lymphoma. The observation of electron micrographs suggested the existence of virions in the CM-1 and CM-2 cells, and these virions were similar to retrovirus in the ultra-structure characteristics. It was found that this virus possesses reverse transcriptase activity. Results obtained from serological assay, molecular hybridization and PCR excluded the existence of other human viruses, which were commonly used in our laboratory. The unknown virus possesses strong transformation activity, and probably is a new retrovirus. Meanwhile, the work on the clone and sequence analysis of this virus are being carried out.
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PMID:Establishment of a human malignant T lymphoma cell line carrying retrovirus-like particles with RT activity. 751 81

Cytokine mRNA expression was analyzed by reverse transcriptase (RT)/PCR in extensively purified normal peripheral CD4+CD45R T cell subsets. Both CD45RA+ and CD45 RO+ populations produced mRNAs for interleukin (IL)-2, IL-2 receptor (alpha chain), IL-6 receptor and tumour necrosis factor (TNF)-beta within 3-4 h of activation. Whilst IL-3 and RANTES were also expressed in both subsets, CD45RO+ cells were clearly the major producers of these cytokines. In contrast, mRNA transcripts for IL-1 alpha, IL-4, IL-5, IL-6, IL-10, interferon gamma (IFN-gamma) and the T cell receptor for IL-1 were almost exclusively induced in CD45RO+ T cells. A population of CD4+ T cells co-expressing intermediate levels of both CD45RA and CD45RO, namely CD45RA+/CD45RO+, appeared to be the major producers of IL-6. Addition of cycloheximide (CHx) 4 h after T cell activation resulted in substantial superinduction of IL-2 mRNA in the CD4+CD45RO+ population but had little effect on CD4+CD45RA+ cells. Taken together, these results show that normal CD4+CD45R T cell subsets exhibit distinct cytokine mRNA profiles and that these differ from the patterns displayed by Th1 and Th2 type T helper clones. Furthermore, they suggest for the first time that IL-2 mRNA turnover is differentially regulated in CD45R T cell subsets.
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PMID:Differential expression and regulation of cytokine mRNAs in normal human CD45R T cell subsets. 751 60

Cytokine gene expression was analysed by reverse transcriptase-polymerase chain reaction (RT-PCR) amplification of RNA from 27 human liver allograft specimens diagnosed as acute (n = 19) or chronic (n = 8) rejection and from 12 normal human livers. In initial screening experiments, mRNA for cytokines interleukin (IL)-1 beta, IL-6, IL-10 and gamma-interferon (IFN-gamma) was expressed in all normal livers and almost all allograft specimens tested. IL-2 mRNA was expressed at barely detectable levels in four of 12 normal livers screened and in 20 of 26 liver allograft specimens with rejection. This constitutive expression of cytokine mRNA required semiquantitative PCR analysis to differentiate levels of cytokine mRNA expression between specimens. Titration of cDNA prior to PCR amplification was initially used and showed significantly more IL-2 (p = 0.02) and IFN-gamma (p = 0.03) in acute rejection compared to normal liver. There was also significantly less IL-10 in chronic rejection compared to acute rejection (p = 0.02) or normal liver (p = 0.01) and less IL-6 in acute rejection compared to chronically rejecting liver (p = 0.05). IL-1 beta (p = 0.04) and IL-6 (p = 0.01) were reduced in acute rejection compared to normal liver. The slight increase of IL-2 in acute rejection and the slight decrease of IL-10 in chronic rejection was confirmed by a second semiquantitative analysis which involved removal of aliquots of PCR reaction at successive cycles followed by dot-blotting and hybridization.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Intragraft cytokine mRNA levels in human liver allograft rejection analysed by reverse transcription and semiquantitative polymerase chain reaction amplification. 752 41

Hematopoietic progenitors obtained from the bone marrow of healthy adults fail to undergo clonogenic maturation in vitro if a source of hematopoietic growth factors is not included in the culture dishes. In contrast, a fraction of similarly purified progenitors obtained from umbilical cord blood undergo clonogenic maturation even in the absence of added growth factors. We postulated that production of hematopoietic growth factors within the culture dishes containing the progenitors of umbilical cord blood origin might be responsible. We postulated further, that this production might be by non-progenitor cells co-plated along with the progenitors, or alternatively by CD34+ cells themselves, or by cells clonally derived from CD34+ cells. To test these possibilities we first assessed the effect of including in the cultures neutralizing antibody directed against various growth factors. Inclusion of anti-granulocyte macrophage colony-stimulating factor (GM-CSF) and anti-interleukin-3 (IL-3) (but not anti-IL-2) significantly reduced the growth factor independence of cord blood progenitors (P < .005 and P < .01). Inclusion of both anti-GM-CSF and anti-IL-3 almost completely ablated the spontaneous colony growth (P < .001). Inclusion of IL-10 also reduced, in a concentration-dependent fashion, the spontaneous generation of umbilical cord blood-derived colonies. Transcripts for GM-CSF and IL-3 were detected, by reverse transcriptase-polymerase chain reaction (RT-PCR), in the CD34+ cells from cord blood and from adult marrow. When plated without added growth factors, however, the CD34+ cells of adult marrow origin failed to produce colonies, whereas 6% of cord blood CD34+ cells similarly cultured did so. When these growth factor independent colonies were plucked from culture, transcripts for GM-CSF and IL-3 were identified in all. We conclude that production of GM-CSF and IL-3 occurs within culture dishes containing hematopoietic progenitors of umbilical cord origin, and that this explains some of their apparently unique features of in vitro growth.
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PMID:Possible mechanisms accounting for the growth factor independence of hematopoietic progenitors from umbilical cord blood. 752 47

At the time of human embryo implantation, large numbers of maternal CD56brightCD16- NK cells appear in the uterus. These unusual lymphocytes are believed to control the migration and differentiation of highly invasive fetally derived trophoblast cells, which infiltrate into the maternal uterus to remodel the spiral arteries during the first trimester. One possible mechanism of control is by cytokine production. In this study, highly purified (> 99%) populations of first trimester decidual CD56brightCD16- NK cells and CD3+ T lymphocytes were obtained by using a FACS. These cells were examined by reverse transcriptase PCR for their expression of mRNAs for the following cytokines: granulocyte-macrophage (GM)-CSF, CSF-1, TNF-alpha, IFN-gamma, TGF-beta 1, leukemia-inhibitory factor (LIF), and IL-2. Then, the expression was compared with that of resting PBL. The identity of the PCR products was verified by Southern blotting and hybridization with cytokine-specific probes. Both decidual CD56brightCD16- NK cells and CD3+ T cells were found to express mRNA for CSF-1, TNF-alpha, IFN-gamma TGF-beta 1, and LIF, but GM-CSF mRNA was detected only in CD56bright NK cells. IL-2 mRNA was detected in only some decidual T cell samples, and then only after at least two rounds of amplification. In contrast, peripheral blood CD56brightCD16- NK cells, CD56dimCD16+ NK cells, and CD3+ T cells expressed mRNA only for TNF-alpha and TGF-beta 1, but not for GM-CSF, CSF-1, IFN-gamma, LIF, or IL-2. These results suggest that both decidual NK cells and decidual T cells produce a variety of cytokines that may be involved in the control of trophoblast migration and differentiation during pregnancy.
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PMID:Screening for cytokine messenger ribonucleic acids in purified human decidual lymphocyte populations by the reverse-transcriptase polymerase chain reaction. 752 3


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