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)

This review considers the potential reduction of embryo mortality in vitro and in vivo in ruminants. Data on cytokines provided by different fields of reproductive immunology and biology were collated. Because of the crucial importance of the local interactions between the embryo and its dam, the expression of growth-factor and cytokine genes was analysed in the embryo proper, trophoblast, oviduct and endometrium by reverse transcriptase polymerase chain reaction in sheep and in cattle during the pre- and periimplantation periods. Many deleterious cytokines, such as tumour necrosis factor-alpha, interferon-gamma (IFN-gamma), interleukin-2 (IL-2), and beneficial cytokines, such as transforming growth factor-beta, leukaemia inhibiting factor, colony-stimulating factor-1 (CSF-1), granulocyte-macrophage CSF, IL-1, IL-3, IL-4, IL-6, IL-10 and IFN-tau appeared to be involved in embryo survival in ruminants and other species. Their administration is efficient in a murine experimental model (CBA/J x DBA/2) of embryonic and fetal mortality. For instance, recombinant ovine IFN-tau (roIFN-tau) injected at the moment of implantation drastically reduces embryonic mortality in this model. In ruminants, roIFN-tau and recombinant bovine IFN-tau are very efficient in maintaining progesterone luteal secretion in cyclic animals. The involvement of IFN-tau in the mechanisms of maternal pregnancy recognition are particularly detailed in relation to inhibition of 13,14 dihydro-15-keto-prostaglandin F2 alpha (PGFM) pulses and oxytocin uterine receptivity. A synthetic model of the anti-luteolytic effects of IFN-tau on the endometrial cell is proposed. Finally, the particular potential of serum pregnancy-specific proteins (PSPs: PSPB, PSP60, pregnancy-associated glycoprotein) for monitoring embryo survival, with examples given for cattle and sheep is underlined.
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PMID:Recent developments and potentialities for reducing embryo mortality in ruminants: the role of IFN-tau and other cytokines in early pregnancy. 926 83

Response to interferon-alpha (IFN-alpha) treatment in hepatitis C is poorer when cirrhosis is present. In the third Australian multicentre hepatitis C trial, Aushep-3, we examined the efficacy and tolerability of an intensive 24-week course of interferon-alpha 2a in Child-Pugh grade A patients with chronic hepatitis C and cirrhosis. This was an open uncontrolled trial of 4.5 million units (MU) of IFN-alpha 2a daily for 24 weeks; follow-up was 48 weeks. Chronic hepatitis C and cirrhosis were confirmed histologically. HCV RNA was determined in serum by reverse transcriptase polymerase chain reaction (PCR), and viral genotyping was by line-probe assay. Treatment response was defined as a reduction of alanine aminotransferase (ALT) to less than 1.5 times the upper limit of normal (and by at least 50% of pretreatment values) at weeks 20 and 24. Sustained response was defined as normal serum ALT after treatment from trial week 28 until week 48. Among the 56 patients, a treatment response occurred in 18 (32% by intention-to-treat; 42% of those who completed treatment) and eight (14%) had a sustained response. At 24 weeks, HCV RNA was not detectable in 12 of 17 treatment responders, and remained negative at 48 weeks in six of eight sustained responders. Treatment response by genotype occurred in 75% of patients with HCV type 2, in 38% with HCV type 3a and in 12% with HCV genotype 1. Sustained response occurred in only one (4%) patient with HCV genotype 1 but in five (20%) with genotypes 2 or 3a. Among 13 patients withdrawn, nine were for adverse effects, most often haematological; 10 others underwent dose reduction for adverse effects. It is concluded that a sustained biochemical and viral response to treatment with IFN-alpha 2a can be obtained in some patients with hepatitis C and cirrhosis, particularly those with genotypes 2 or 3a. Therefore, patients with cirrhosis should be considered for interferon treatment on an individual basis. Genotyping may improve case selection, but vigilance is required for haematological complications.
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PMID:Efficacy and tolerance of a 6-month treatment course of daily interferon-alpha 2a for chronic hepatitis C with cirrhosis. The Australian Hepatitis C Study Group. 931 Sep 30

We explored expression and possible function of interferon-gamma (IFN-gamma) in cultured fetal (E15) rat dorsal root ganglion neurons combining whole cell patch-clamp electrophysiology with single cell reverse transcriptase polymerase chain reaction and confocal laser immunocytochemistry. Morphologically, we located IFN-gamma protein in the cytoplasm of the neurons in culture as well as in situ during peri- and postnatal development. Transcripts for classic IFN-gamma and for its receptor were determined in probes of cytoplasm sampled from individual cultured neurons, which had been identified by patch clamp electrophysiology. In addition, the cultured neurons expressed both chains of the IFN-gamma receptor. Locally produced IFN-gamma acts back on its cellular source. Phosphorylation and nuclear translocation of the IFN-inducible transcriptional factor STAT1 as well as IFN-gamma-dependent expression of major histocompatibility complex class I molecules on the neuronal membrane were noted in untreated cultures. However, both processes were substantially blocked in the presence of antibodies neutralizing IFN-gamma. Our findings indicate a role of IFN-gamma in autocrine regulation of sensory neurons.
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PMID:Interferon gamma gene expression in sensory neurons: evidence for autocrine gene regulation. 939 71

This study investigates the hypothesis that the elevation of intracellular cAMP may affect cytokine-induced expression of adhesion molecules on human vascular smooth muscle cells. In cultured human smooth muscle cells from coronary arteries and saphenous veins, tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) induced the expression of intercellular adhesion molecule (ICAM-1) and vascular cell adhesion molecule (VCAM-1), whereas interferon-gamma (INF-gamma) selectively stimulated the expression of ICAM-1. Adenylyl cyclase was stimulated either by the stable prostacyclin mimetic cicaprost or by forskolin. Adhesion molecules were detected by a cell surface enzyme immunoassay and the respective mRNA by reverse transcriptase polymerase chain reaction (rt-PCR). Cicaprost as well as forskolin significantly inhibited TNF-alpha- and IL-1 beta-induced cell surface expression of ICAM-1 and VCAM-1. Semiquantitative rt-PCR measurements showed a marked decrease of TNF-alpha- and IL-1 beta-induced mRNA levels of both adhesion molecules after preincubation with cicaprost. The stability of TNF-alpha-induced ICAM-1 and VCAM-1 expression at mRNA and protein level was not altered by cicaprost. The IFN-gamma-induced increase of cell surface expression of ICAM-1 and the respective mRNA levels, however, were not significantly altered by elevation of intracellular cAMP. Basal and stimulated cAMP levels, measured by radioimmunoassay, did not differ in TNF-alpha- and IFN gamma-treated cells. The present results demonstrate that the expression of adhesion molecules on human smooth muscle cells induced by cytokines is differentially modulated by activation of adenylyl cyclase.
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PMID:Regulation of tumor necrosis factor alpha- and interleukin-1-beta-induced induced adhesion molecule expression in human vascular smooth muscle cells by cAMP. 940 29

Interferon-alpha (IFN alpha) mediates its biological effects through activation of the JAK-STAT signaling pathway and it has been shown to be one of most effective therapeutic agents for a number of hematological malignancies, including cutaneous T-cell lymphoma (CTCL). Nevertheless, its efficacy is limited by the development of clinical resistance but the reasons for resistance in CTCL are unknown. Here, we report the development of an IFN alpha-resistant CTCL cell line (HUT78R), characterized by its ability to proliferate in high concentration of recombinant IFN alpha, which can be used as a model system to study IFN resistance. The levels of IFN receptor expression and binding affinity were found to be comparable between the parental sensitive (HUT78S) and resistant (HUT78R) cells. However, IFN alpha stimulation failed to induce interferon-stimulated gene factor 3 (ISGF3) complex formation in HUT78R cells. In addition, the expression of the IFN-inducible 2-5 OAS gene was significantly reduced in HUT78R cells, suggesting the presence of a defect in the Jak-STAT signaling pathway. Our results showed that the IFN alpha-activated form of a latent transcriptional factor STAT1 was not found in HUT78R cells, whereas activated STAT2 and STAT3 were clearly detectable. By Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR) analyses, we found that HUT78R cells do not express any STAT1 protein or mRNA, suggesting the possibility of a null mutation in the STAT1 gene. Resistance to the growth inhibitory effect of IFN alpha in CTCL cells may result from lack of STAT1 expression.
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PMID:Interferon-alpha resistance in a cutaneous T-cell lymphoma cell line is associated with lack of STAT1 expression. 942 11

Epstein-Barr-virus-associated posttransplant lymphoproliferative disease ranges from transient lymphadenitis to aggressive lymphoma. This study characterizes an in vitro model to study the pathogenesis of this disease with a cell culture system. Five B-cell lines derived from posttransplant lymphoproliferative disease tissue were characterized with regard to immunophenotype, karyotype, molecular genetics, cytokine production, and growth regulation. All cell lines expressed CD19, CD21, CD22, CD43, and CD77, but not CD10 antigens. Immunoglobulin light chain restriction was seen in four of five cell lines, and cytogenetic abnormalities were demonstrable in three of the five. Cells proliferating in culture contained multiple Epstein-Barr virus episomes and showed lytic viral replication. All cell lines produced tumor necrosis factor-beta and interleukin-10 without evidence of autocrine growth regulatory loops involving these cytokines. No evidence of IL-1 alpha, IL-2, IL-4, IL-5 or IL-6 production was found by reverse transcriptase polymerase chain reaction. Adding 500 U IFN-alpha/ml to the culture medium resulted in 30% inhibition of [3H]thymidine incorporation.
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PMID:In vitro culture of B-lymphocytes derived from Epstein-Barr-virus-associated posttransplant lymphoproliferative disease: cytokine production and effect of interferon-alpha. 946 86

The relationship between serum hepatitis C virus (HCV) RNA and the outcome of alpha-interferon (alpha-IFN) therapy in patients with chronic hepatitis C has important implications for therapeutic research and clinical care. Serum HCV RNA was tested for HCV genotype and quantified by a standardized reverse transcriptase-polymerase chain reaction assay as a measure of viral load in a cohort of 130 patients with chronic hepatitis C treated with alpha-IFN at a standard dose of 3 million units three times a week scheduled for 6 (n = 50) or 12 months (n = 76). Twenty-one of 126 evaluable patients (16.7%) developed a sustained complete response to alpha-IFN according to biochemical and virological criteria. The 3 pretreatment independent factors associated with a sustained complete response were a low baseline serum HCV RNA concentration, non-1 HCV genotype, and female sex. A multivariate logistic regression model, with pretreatment and month 1 variables, showed that a lower baseline serum HCV RNA concentration, female sex, and a greater suppression of RNA were the significant predictors of sustained complete response. The lowest baseline serum HCV RNA concentration was observed in patients with genotype 2 infection and the greatest decrease in HCV RNA from baseline to month 1 in those with genotype 3. The findings suggest that measuring HCV RNA in serum before and soon after beginning treatment can be helpful for selecting patients who are most likely to have a sustained complete response to standard schedule of alpha-IFN and for identifying patients in whom alternative strategies should be examined.
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PMID:Baseline level and early suppression of serum HCV RNA for predicting sustained complete response to alpha-interferon therapy. 949 64

There is a need for fast and sensitive methods to evaluate the response of patients with chronic myeloid leukaemia (CML) to interferon-alpha (IFN-alpha) therapy to complement cytogenetic analysis of Philadelphia (Ph) chromosome-positive metaphases. We have used interphase FISH (fluorescence in situ hybridization) and competitive RT-PCR (reverse transcriptase-polymerase chain reaction) techniques for detection of BCR-ABL-positive cells to measure suppression of leukaemic clone in a series of 51 follow-up samples from 24 CML patients undergoing IFN-alpha treatment. Interphase FISH analysis of the malignant clone in bone marrow using BCR and ABL probes was found to be highly correlated to conventional G-banding metaphase examination (r = 0.98). RT-PCR quantification of BCR-ABL mRNA transcripts in blood also showed a high degree of concordance with the proportion of Ph-positive metaphases (r = 0.93). In addition, the degree of cytogenetic response did not influence the equivalence between karyotype analysis and molecular methods. We concluded that interphase FISH and competitive RT-PCR provide reliable information on residual tumour burden and response to IFN-alpha in CML patients. These molecular methods may significantly improve the efficiency of residual disease monitoring during IFN-alpha therapy of CML.
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PMID:Interphase cytogenetics and competitive RT-PCR for residual disease monitoring in patients with chronic myeloid leukaemia during interferon-alpha therapy. 963 1

The immunosuppressive drug mycophenolate mofetil (MMF) acts by releasing mycophenolic acid (MPA), which inhibits the enzyme inosine monophosphate dehydrogenase (IMPDH) and thus inhibits de novo purine synthesis. Unlike cyclosporine (CsA), MMF has no direct effect on cytokine gene expression in vitro. We examined the effect of MMF, in comparison to CsA, on in vivo production of interferon-gamma (IFN-gamma) in mice. Two stimuli for IFN-gamma induction were used: (1) allogeneic P815 mastocytoma ascites tumour cells and (2) bacterial lipopolysaccharide (LPS). The allogeneic response is dependent on clonal expansion of T cells, while the LPS response is polyclonal and T cell independent. Since major histocompatibility complex (MHC) induction in mouse kidney is IFN-gamma dependent, we assessed the in vivo induction of IFN-gamma indirectly by measuring MHC induction in mouse kidneys in three systems: radiolabelled antibody binding assay, immunoperoxidase staining in tissue sections, and Northern blotting for steady-state MHC mRNA levels. IFN-gamma steady-state mRNA levels were assessed by reverse transcriptase polymerase chain reaction (RT-PCR). In the allogeneic response, MMF (40-160 mg/kg/day) reduced the production of IFN-gamma in a dose-dependent fashion. MHC class I and II induction was reduced by 35% to 74% and 30% to 74%, respectively. However, MMF had less effect on the induction of MHC by a nonimmune stimulus, bacterial LPS, whereas CsA reduced the induction of IFN-gamma in both responses. We conclude that MMF reduces the IFN-dependent induction of MHC in vivo during specific immune responses, probably by limiting clonal expansion, while preserving nonspecific cytokine production in response to LPS.
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PMID:Mycophenolate mofetil reduces production of interferon-dependent major histocompatibility complex induction during allograft rejection, probably by limiting clonal expansion. 964 Jun 25

Subcutaneous application of interferon-beta1b (IFN-beta1b) is an established therapy for patients with relapsing-remitting multiple sclerosis (RRMS), but early side effects are still a major concern. In vitro studies with myelin basic protein (MBP)-specific T-cell lines revealed a synergistic suppressive effect of IFN-beta1b and the phosphodiesterase inhibitor pentoxifylline (PTX) on proliferation and the production of tumor necrosis factor-alpha (TNF-alpha), lymphotoxin (LT), and interferon-gamma (IFN-gamma). In an initial, open labeled prospective trial, the cytokine messenger RNA (mRNA) expression of blood mononuclear cells from MS patients, receiving either IFN-beta1b alone or in combination with oral PTX, was determined by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). Patients treated with IFN-beta1b alone reported more side effects during the first 3 months of treatment and had upregulated TNF-alpha as well as IFN-gamma mRNA expression during the first month, which was not detected in patients receiving both drugs. A synergistic effect of both drugs was observed on the upregulation of interleukin (IL)-10 mRNA, which was accompanied by an increase in IL-10 serum levels. Both in vitro and in vivo data suggest that co-treatment of IFN-beta1b with PTX is a promising approach to correct the disturbed cytokine balance in MS patients.
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PMID:Synergistic immunomodulatory effects of interferon-beta1b and the phosphodiesterase inhibitor pentoxifylline in patients with relapsing-remitting multiple sclerosis. 966 87


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