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)

Several cholic acid derivatives such as taurolithocholic acid, lithocholic acid 3-sulfate, taurolithocholic acid 3-sulfate, and glycolithocholic acid 3-sulfate were shown to inhibit selectively the replication of human immunodeficiency virus type 1 (HIV-1) in vitro. These compounds completely protected MT-4 cells against HIV-1-induced cytopathogenicity at a concentration of 100 micrograms/ml, whereas no toxicity for the host cells was observed at 200 micrograms/ml. They also inhibited HIV-1 antigen expression in HIV-1-infected CEM cells. The bile acids (cholic acid, deoxycholic acid, chenodeoxycholic acid, and lithocholic acid) did not show any inhibitory effect on HIV-1 replication at concentrations that were not toxic to the host (MT-4) cells. From a structure-function analysis of a number of cholic acid derivatives, the presence of either a sulfonate (as in the tauro conjugates) or a sulfate group as well as the "litho" configuration appeared to be necessary for the expression of anti-HIV-1 activity. The active cholic acid derivatives did not directly inactivate the virus particles at the concentrations that were not toxic to the host cells. Lithocholic acid 3-sulfate, taurolithocholic acid 3-sulfate, and glycolithocholic acid 3-sulfate, but not taurolithocholic acid, partially inhibited virus adsorption to MT-4 cells. These three compounds were also inhibitory to the reverse transcriptase activity associated with HIV-1.
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PMID:Selective activity of several cholic acid derivatives against human immunodeficiency virus replication in vitro. 230 4

Three chondroitin sulphates and five chondroitin polysulphates, with molecular weights ranging from 3000 to 30,000 daltons, were evaluated applying the MT-4 cell-culture assay for inhibition of HIV-1 replication. These results were compared with those obtained with compounds of known in vitro antiretroviral activity, namely, dermatan sulphate, heparin, dextran sulphate, pentosan polysulphate, zidovudine (AZT) and suramin. Chondroitin polysulphate with a molecular weight (MW) of 9000 daltons (CPS 9000) was the most effective polyanionic compound studied. In contrast with zidovudine, this CPS 9000 was not toxic for MT-4 cells up to a concentration of 500 micrograms/ml. Moreover, CPS 9000 is highly specific for inhibition of HIV-1 reverse transcriptase.
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PMID:In vitro anti-HIV-1 activity of chondroitin polysulphate. 247 44

From a series of newly synthesized 3'-fluoro-modified nucleosides the C-5-chloro-substituted derivative of 2',3'-dideoxy-3'-fluorouridine (FddUrd) and the 4-thio analogue of 2',3'-dideoxy-3'-fluorothymidine (FddUrd) emerged as the most efficient and selective anti-HIV agents. Their antiviral doses (ED50) proved to be 700-and 480-fold below their toxic doses (CD50) in MT-4 cells. The 50% inhibitory dose of cell proliferation of the 5-chloro-substituted FddUrd and its parent agent FddUrd was found to be in the millimolar range for various other human cell-lines and for mouse CFU-GM. The 5'-triphosphate of FddUrd as well as of its 5-Chloro derivative are demonstrated to be two of the most active and selective inhibitors of the HIV-reverse transcriptase (IC50 = 0.07 +/- 0.01 and 0.04 +/- 0.006 microM).
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PMID:Inhibition of HIV-replication by 3'-fluoro-modified nucleosides with low cytotoxicity. 248 Jan 26

MT-4 cells persistently infected with human immunodeficiency virus type 1 (HIV-1) (MT-4/HIV-1) were recently isolated (K. Ikuta, C. Morita, M. Nakai, N. Yamamoto, and S. Kato, Japan. J. Cancer Res. (Gann), 79, 418-423, 1988). Mouse hybridoma cell clones producing monoclonal antibodies (MoAbs) to HIV-1 gag p24 and p18, and pol reverse transcriptase (RT) were isolated by using this MT-4/HIV-1 cell line for the screening of MoAb production by the immunofluorescence (IF) test. By indirect IF tests of acetone-fixed cells with these MoAbs, the IF intensities in MT-4/HIV-1 cells were found to be higher than those in the other HIV-1 infected cells, such as MOLT-4/HIV-1, HL-60/HIV-1, and U937/HIV-1 cells. Cell surface expression of the HIV-1 gag p24 and p18 antigens examined by IF and radioimmune techniques with these MoAbs revealed the p24 and p18 antigens to be expressed strongly on the cell surface of MT-4/HIV-1 cells and faintly on the cell surface of MOLT-4/HIV-1 cells, respectively. However, monoclonal antibody isolated in the present study failed to detect pol RT antigen on the surface of MT-4/HIV-1 cells. These results indicate that the gag p24 and p18 antigens are expressed, at least in part, on the surface of HIV-1-infected cells.
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PMID:Expression of human immunodeficiency virus type 1 (HIV-1) gag antigens on the surface of a cell line persistently infected with HIV-1 that highly expresses HIV-1 antigens. 249 13

Soybean saponins isolated from soybean seeds were investigated for their antiviral activity on HIV in vitro, using an HTLV-I-carrying cell line, MT-4. Saponin B1 completely inhibited HIV-induced cytopathic effects and virus-specific antigen expression 6 days after infection at concentrations greater than 0.5 mg/ml. Saponin B2 also inhibited HIV infection, although less potently. Both saponin B1 and B2 had no direct effect on the reverse transcriptase activity of HIV. Saponin B1 also inhibited HIV-induced cell fusion in the MOLT-4 cell system. The results of this study suggest that soybean saponins, especially saponin B1, have inhibitory activity against HIV infection.
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PMID:Inhibitory effect of glycosides like saponin from soybean on the infectivity of HIV in vitro. 257 82

A sulfate (GE-3-S) prepared by chlorosulfonic acid treatment of GE-3, a partially acetylated beta(1----6) glucan of the lichen Umbilicaria esculenta, inhibited the cytopathic effect of human immunodeficiency virus (HIV) and suppressed the HIV-antigen expression in Molt-4 (clone 8) cells. GE-3-S also suppressed the giant cell formation of HIV-infected Molt-4 cells, and inhibited HIV-induced plaque formation by 50% at the dose of 19.5 micrograms/ml and completely at 250 micrograms/ml in MT4 cells. GE-3-S had no direct effect on the reverse transcriptase of HIV.
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PMID:Inhibitory effect of a lichen polysaccharide sulfate, GE-3-S, on the replication of human immunodeficiency virus (HIV) in vitro. 257 16

A novel 6-substituted acyclouridine derivative, 1-[(2-hydroxy-ethoxy) methyl]-6-phenylthiothymine (HEPT), has proved to be a potent and selective inhibitor of human immunodeficiency virus type 1 (HIV-1) in vitro. HEPT inhibits HIV-1 replication in various T4 cell cultures as well as peripheral blood lymphocytes and macrophages. The 50% antiviral effective concentration for HIV-1 (HTLV-IIIB) in MT-4 cells is 7.0 microM, while the 50% cytotoxic concentration for mock-infected MT-4 cells is 740 microM. Although HEPT is inhibitory to various strains of HIV-1, it has no effect on the replication of other retroviruses including HIV type 2. In contrast with the dideoxynucleoside (i.e. azidothymidine) 5'-triphosphates, the triphosphate of HEPT does not interact with HIV-1 reverse transcriptase. The mechanism of action of HEPT remains subject of further study.
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PMID:Highly specific inhibition of human immunodeficiency virus type 1 by a novel 6-substituted acyclouridine derivative. 257 80

The effect of tumor necrosis factor (TNF) on the replication of human immunodeficiency virus type 1 (HIV-1) was investigated in several T4 lymphocyte cell lines. TNF markedly enhanced the cytopathogenicity of HIV-1, virion-associated reverse transcriptase (RT) activity in the cell culture supernatant, and viral antigen expression in MOLT-4 cells as early as 3 days after HIV-1 infection. A slight increase in RT activity was also observed in the supernatant of H9 cell cultures exposed to TNF. However, TNF did not increase either RT activity in MT-4 cell supernatants or viral antigen expression in HUT-78 cells. Thus, TNF is able to stimulate the replication of HIV-1 in de novo infected T4 cells although not all T4 cells seem to be sensitive to this stimulatory effect.
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PMID:Tumor necrosis factor enhances replication of human immunodeficiency virus (HIV) in vitro. 291 52

The effect of 3'-azido-2',3'-dideoxythymidine (AZT) on the human immunodeficiency virus (HIV)-associated giant cell formation was studied in vitro. For this purpose we developed a coculture system using Molt-4 and its virus-producing cell, Molt-4/HTLV-III, which induced syncytia very efficiently. Treatment of the cocultures with 1 and 5 microM of AZT did not inhibit induction of multinucleated giant cells, although only 0.1 microM AZT resulted in almost complete inhibition of HIV replication in Molt-4 cells by cell-free virus infection. This was also evidenced by the assays for viral antigen-positive cells, reverse transcriptase activity, and virus particles released from cell cultures after AZT treatment. When the cocultures were treated with 1% neutralizing antibody (NA) from HIV-infected individuals alone, giant cell formation was inhibited to some extent. However, the concomitant treatment of culture with AZT and NA resulted in much stronger inhibition of giant cell formation. The amount of CD4 antigens on the surface of cells was reduced greatly in the HIV producer cells (Molt-4, H9, and MT-4 cells) as compared to their HIV-free counterparts. These data suggest that (1) both CD4 antigen and viral antigens on the surface of cells play central roles in the induction of multinucleated giant cells and (2) AZT is more effective in inhibition of viral spread in patients with higher NA, probably at an earlier stage of the disease than in patients with lower NA titer.
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PMID:Effect of 3'-azido-2',3'-dideoxythymidine (AZT) and neutralizing antibody on human immunodeficiency virus (HIV)-induced cytopathic effects: implication of giant cell formation for the spread of virus in vivo. 311 Oct 83

An extract of culture medium of Lentinus edodes mycelia (LEM) was prepared. This was further fractionated by 50% ethanol precipitation and both the resulting product, E-P-LEM, and LEM were studied to evaluate their effect on the activity of human immunodeficiency virus (HIV) in vitro. The experiments were performed using either a cell-free infection system with MT-4 cells, or a cell-to-cell infection system with MOLT-4 cells, which induces multinucleated giant cells very efficiently. E-P-LEM almost completely blocked both the cytopathic effect of giant cell formation and specific antigen expression due to HIV, whereas LEM before ethanol precipitation blocked the expression of HIV antigen in MT-4 cells only at a high concentration. Pretreatment of the virus with E-P-LEM before infection blocked HIV infection in the target cells. Thus, the inhibitory effect of LEM and E-P-LEM on HIV could be due to a blocking of the initial stages of HIV infection. Moreover, reverse transcriptase activity of avian myeloblastosis virus was inhibited.
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PMID:Inhibition (in vitro) of replication and of the cytopathic effect of human immunodeficiency virus by an extract of the culture medium of Lentinus edodes mycelia. 317 37


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