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

---

Query: EC:2.7.7.49 (reverse transcriptase)
31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In American cutaneous leishmaniasis (ACL), Leishmania parasites enter the epidermis of the host via the bite of infected sandflies. Immune responses against the parasite vary from "effective" in localized (LCL) to a state of "selective anergy" in diffuse (DCL) cutaneous leishmaniasis, whereas the intermediate muco-cutaneous form (MCL) is characterized by an exacerbated cell-mediated immunity. We have shown that in LCL epidermis, Langerhans cells (LC) are increased, HLA-DR is universally expressed and intercellular adhesion molecule-1 (ICAM-1) immunoreactivity is distributed in patches. In addition, mRNA for IL-1 beta, IL-8, TNF alpha, TNF beta, and INF gamma may be detected in epidermal sheets by reverse transcriptase followed by polymerase chain reaction (RT-PCR). In contrast, DCL epidermis shows fewer LC than LCL epidermis, and expression of ICAM-1, HLA-DR, and IL-1 beta mRNA cannot be detected. MCL lesions show a mucosal epithelium lacking LC, but ICAM-1 is universally expressed. The clinical manifestations of ACL can be reproduced experimentally in different strains of inbred mice. In healthy mice, we have shown a positive correlation between LC and dendritic epidermal T cells (DETC) numbers. This correlation was not, however, observed in L. mexicana-infected mice, suggesting that infection alters the balance between the two cell types. In addition, agents that modulate LC and DETC cell densities change the development of experimental leishmaniasis. These results suggest that the epidermis is essential in determining the type of immune response that is developed against the Leishmania parasites.
...
PMID:Epidermal compromise in American cutaneous leishmaniasis. 135 84

The mesothelium is a flat epithelial lining of serous cavities that could gate the traffic of molecules and cells between the circulation and these body compartments. The present study was designed to elucidate the capacity of mesothelial cells to express adhesion molecules and chemoattractant cytokines, two fundamental mechanisms of regulation of leukocyte recruitment. Cultured human mesothelial cells express appreciable levels of intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1), and these were increased by in vitro exposure to tumor necrosis factor (TNF), interferon gamma (IFN-gamma), or TNF and IFN-gamma. Interleukin 1 (IL-1) was a less consistent stimulus for adhesion molecule expression in vitro. Unlike endothelial cells, used as a reference cell population, resting or stimulated mesothelial cells did not express E-selectin and ICAM-2, as assessed by flow cytometry. Analysis of VCAM-1 mRNA by reverse transcriptase and polymerase chain reaction using appropriate primers revealed that mesothelial cells expressed both the seven- and the six-Ig domain transcripts, with predominance of the longer species. Monocytes bound appreciably to "resting" and, to a greater extent, to stimulated mesothelial cells. Monocytes exposed to IFN-gamma and lipopolysaccharide, used as prototypic activation signals, showed increased capacity to bind mesothelial cells. Anti-CD18 monoclonal antibody significantly inhibited binding of monocytes to mesothelial cells, and this blocking effect was amplified by anti-very late antigen 4. Mesothelial cells were able to express the chemotactic cytokines IL-8 and monocyte chemotactic protein 1 at the mRNA and protein levels. These results indicate that mesothelial cells can express a set of adhesion molecules (ICAM-1 and VCAM-1) overlapping with, but distinct from, that expressed in vascular endothelium (ICAM-1, ICAM-2, VCAM-1, E-selectin), and that these are functionally relevant for interacting with mononuclear phagocytes. The regulated expression of adhesion molecules and chemotactic cytokines by mesothelial cells is probably important in inflammatory and immune reactions that involve serous cavities, such as the long-known macrophage appearance and disappearance reactions.
...
PMID:Expression of adhesion molecules and chemotactic cytokines in cultured human mesothelial cells. 138 76

As a preliminary to transducing human melanoma cells with lymphokine genes, we sought for constitutive gene expression and production of eight interleukins, tumour necrosis factors and granulocyte-colony stimulating factor in 19 human melanoma cell lines. Conversion of RNA into cDNA by reverse transcriptase and polymerase chain reaction (RT-PCR) were employed to evaluate gene expression while enzyme-linked immunosorbent assays (ELISA) or biological assays were used to assess the presence of proteins. No expression of interleukins (IL) 3, 4, and 5 or interferon-gamma RNA was found, while the other cytokines were variably expressed in melanoma lines, with IL-1 alpha, IL-1 beta, IL-6, IL-8, being detectable in most of the lines. At protein level, 10 melanoma cells were tested with ELISA and all were found to produce IL-8, five produced IL-6, two tumour necrosis factor (TNF)-alpha, one IL-1 alpha and two TNF beta. The levels of TNF beta were at the limit of test sensitivity. The amount of various cytokines released by the different lines varied widely. Biological assay with the D10-G4 clone confirmed the presence of IL-1 alpha in the supernatant of melanoma (ME) 10221 and revealed an IL-1 activity in the supernatant of Me 4024/1. The proliferating activity of melanoma supernatants on D10-G4 was inhibited by treatment with polyclonal antibodies against IL-1 alpha but not with antibodies against IL-1 beta. TNF biological activity was tested against the TNF-susceptible fibrosarcoma WEHI 164 clone 13.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Expression of cytokine genes, including IL-6, in human malignant melanoma cell lines. 145 Jun 72

V gamma 9+ T cells from malaria non-exposed donors make proliferative responses to Plasmodium falciparum on in vitro stimulation. V gamma 9+ cells are strongly activated by components of the schizont stage of the parasite and by antigens released into the culture upon schizogony, while CD4+V gamma 9- cells are stimulated by the earlier stages of the parasite. Using reverse transcriptase-polymerase chain reaction (RT-PCR) we determined mRNA expression for 14 cytokines in highly purified V gamma 9+ cells enriched by positive selection after in vitro stimulation with P. falciparum schizont antigens. Interferon-gamma (IFN-gamma) and Tumor Necrosis Factor-alpha (TNF-alpha) were detected in all samples tested. The majority of samples also expressed TNF-beta, transforming growth factor-beta (TGF-beta) and Interleukin-8 (IL-8). Only occasional samples expressed IL-2, IL-5 and IL-10. Using the ELISPOT assay we found that a large fraction of the reactive V gamma 9+ cells produced IFN-gamma and that gamma delta T cells are the major producers of IFN-gamma in cultures stimulated with schizont antigens. The majority of V gamma 9+ cells in these cultures also express the membrane-bound form of TNF-alpha. Expression of these cytokines speaks for a cytolytic and/or inflammatory role of gamma delta cells in the response to malaria in non-exposed individuals.
...
PMID:Cytokine profiles for human V gamma 9+ T cells stimulated by Plasmodium falciparum. 750 22

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.
...
PMID:Expression of cytokine/growth factors and their receptors in human melanoma and melanocytes. 750 78

The infiltration of leucocytes into the joint of rheumatoid arthritis (RA) is believed to be mediated by chemotactic factors released by activated cells. In this study, examination was made of the gene expression and production of the chemokine superfamily in RA patients by reverse transcriptase-polymerase chain reaction (RT-PCR) and immunoprecipitation. Cultured synovial fibroblasts were found capable of expressing and producing IL-8, GRO, monocyte chemotactic and activating factor (MCAF), macrophage inflammatory protein-1 alpha (MIP-1 alpha), MIP-1 beta and RANTES in response to IL-1 alpha. The expression of IL-8, GRO, MCAF, MIP-1 alpha, and MIP-1 beta was clearly shown to increase in freshly isolated synovial fluid mononuclear cells (SFMC) of RA patients, in contrast to peripheral blood mononuclear cells (PBMC) of RA patients and normal subjects. The gene expression of RANTES appeared to be the same for RA SFMC, RA PBMC, and normal PBMC. Thus, the over-expression of various chemokines may promote the recruitment of inflammatory cells into rheumatoid inflamed joints.
...
PMID:Expression of the chemokine superfamily in rheumatoid arthritis. 752 8

Recently, the keratinocyte IL-8/IL-8 receptor (IL-8R) pathway has been implicated in the pathogenesis of psoriasis, and there is evidence that the potent macrolide immune suppressant tacrolimus (formerly FK506) can inhibit this pathway in vitro. In this study, determination of the expression of cytokine mRNAs in lesional skin of patients with active disease by reverse transcriptase polymerase chain reaction revealed transcripts for IL-1 beta, tumour necrosis factor-alpha (TNF-alpha), IL-6, IL-8, IL-8R, IL-10, interferon-gamma (IFN-gamma), IL-2R and transforming growth factor-beta (TGF-beta), but not IL-2 or IL-4. IL-8 was the only cytokine expressed in affected skin of all patients but not in clinically normal skin of healthy subjects. In seven CD4+ T cell clones propagated from the lesional skin of an untreated psoriasis patient, IL-8 was expressed by the skin-derived T lymphocytes and not by feeder cells (irradiated autologous blood lymphocytes); IL-1 beta, IL-2, IL-6 and IL-10 were also expressed by some or all of the T cell clones. IL-8 mRNA was not detected in the skin of any patient after the start of systemic tacrolimus therapy; IL-1 beta, IL-6 and IFN-gamma transcripts were also reduced. By 12 weeks, the mean psoriasis area and severity index (PASI) had decreased from 18.8 to 3.8, a reduction of 80%. In the same post-treatment biopsies, however, message for IL-8R persisted. Estimation of circulating IL-8 levels by enzyme immunoassay showed that all patients with detectable IL-8 before treatment had decreased levels in response to treatment with tacrolimus; reductions in PASI scores were accompanied by decreases in IL-8 levels, that varied both in rate and extent. Partial relapse, which in a minority of patients followed the initial period of remission, and was precipitated by drug dose reduction, was accompanied by an increase in circulating IL-8. These findings add credence to the view that the IL-8/IL-8R autocrine/paracrine pathway may be important in the pathogenesis of psoriasis. They further suggest that interference with IL-8 production and/or that of other key chemokines may be an important mechanism underlying the therapeutic efficacy of tacrolimus, and other agents such as cyclosporin A, with similar molecular actions.
...
PMID:IL-8/IL-8 receptor expression in psoriasis and the response to systemic tacrolimus (FK506) therapy. 753 27

Experimental animal models have shown that various cytokines, depending of their specific properties, may support growth and metastasis of tumor cells or even lead to tumor rejection. The analysis of expression of cytokine genes by melanoma cell lines indicated that melanoma cells constitutively produce both autostimulatory and inhibitory cytokines. Using reverse transcriptase polymerase chain reaction analysis, simultaneous expression of several cytokines, including interleukin-1 beta (IL-1 beta), IL-6, IL-8, tumor necrosis factor-alpha, and granulocyte-macrophage colony-stimulating factor, by melanoma cells was found. The same cytokine transcripts were detected in melanocytes, suggesting that cells of the melanocytic lineage express a specific pattern of cytokines in vitro. All these cytokines are known to be able to stimulate effector cells of the host. Additionally, production of mRNA for IL-10, a cytokine with potential immunosuppressive properties, was detected in melanoma cells and melanocytes. These and other cytokines are likely to be involved in the immune response to cancer and at this time it is unknown what the net effects of multiple cytokines are on the outcome of the host response to tumor.
...
PMID:Production of cytokines by human melanoma cells and melanocytes. 759 87

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.
...
PMID:An improved, sensitive, non-radioactive in situ hybridization method for the detection of cytokine mRNAs. 765 59

In this study we tested whether the pattern of cytokines expressed by human carcinomas could account for a different in vivo recruitment of leukocyte subpopulations as a part of the anti-tumor immune response. Two carcinoma cell lines, SK-OV-3 ovary carcinoma and CALU-3 lung carcinoma, were analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR), immunofluorescence and ELISA for the expression and in vitro production of cytokines with chemotactic, proinflammatory and growth-stimulating activity. Although both cell lines displayed a constitutive expression of granulocyte colony-stimulating factor (G-CSF), granulocyte macrophage-CSF (GM-CSF), M-CSF, interleukin (IL-) 1 alpha and IL-8, only CALU-3 cell line expressed IL-10, RANTES (Regulated upon Activation, Normal T Expressed and Secreted) and monocyte-activating protein (MCP)-1. MCP-1 and IL-8 were detected by immunohistochemistry on sections from tumors xenografted in nude mice. To analyze whether the tumor-released cytokines modulate leukocytes in tumor infiltration, we studied the distribution of human peripheral blood leukocytes injected in the proximity of SK-OV-3 and of CALU-3 tumor xenografts. While SK-OV-3 was unable to recruit human leukocytes and appeared to be barely infiltrated by murine CD45+ cells, CALU-3 appeared to be rapidly and heavily infiltrated by human leukocytes which induced tumor necrosis within 18-24 hr.
...
PMID:An in vivo model to compare human leukocyte infiltration in carcinoma xenografts producing different chemokines. 766 28


1 2 3 4 5 6 7 8 9 10 Next >>

---