Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two novel enzyme-linked immunoassays (ELISA) for the quantitation of human immunodeficiency virus type 1 (HIV-1) coded glycoprotein with an Mr 120 (gp120) are described. These are based on the highly specific interaction between gp120 and the mannose-specific lectins from Narcissus pseudonarcissus (NPL) and Galanthus nivalis (GNL). Two systems were developed: (1) an HIV-protein ELISA using HIV-protein (also containing HIV-gp120) for the solid phase and NPL as a detector and (2) a lectin-ELISA using the NPL bound to the solid phase and GNL as detector. The HIV-protein ELISA was validated for quantitation of gp120 within the range 3 to 600 ng/ml; the lectin-ELISA for concentrations between 0.6 and 20000 ng gp120/ml. Serum components did not interfere with the binding of gp120 to the lectins. The ELISAs were used for the quantitation of gp120 in HIV-infected CEM cells in vitro. It was found that gp120 appeared in the medium earlier after infection than HIV-p24 and reverse transcriptase, suggesting that gp120 is released as free glycoprotein. Moreover, the ELISAs were also applied successfully for the detection of compounds that bind to gp120 and for the identification of antibodies directed against the highly pathogenic mannan portion of gp120. These ELISAs are considered to be suitable also for the detection of gp120 in the serum of HIV-infected individuals.
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PMID:Human immunodeficiency virus: novel enzyme-linked immunoassays for quantitation of envelope glycoprotein 120. 187 21

The use of antifungal drugs in immunocompromised patients impose to the laboratory the control of the efficacy of these therapy. With fluconazole, one of the most recent antifungal agents these control use a special method (Central Research Pfizer) different of those they are used with others antifungals. We have comparatively tested, using MIC technic four broth mediums (High Resolution medium (Oxoid) YMB (Difco) YNB dextrose (Autobac) and Casitone) and three agar mediums (HR, YMA, Casitone) incubated at 28 degrees C for 24 and 48 h. The strains of yeasts are isolated from oro-pharyngeal prelevements on HIV antibody positive patients observed during six to twelve months and eventually treated by fluconazole. Sixty patients are controlled, 33 give one or more positive cultures with 74 strains of C. albicans and four other yeasts. By determination of the MICs with seven different methods we find any resistant strains with the MICs range from 3.12 to 12.5 or 25 micrograms/ml.
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PMID:[Laboratory's controls of antifungal treatment by the fluconazole of the candidiasis in immunocompromised patients]. 188 90

The envelope glycoprotein of HIV-I in infected, cultured human T cells is synthesized as a precursor of apparent Mr 160 kDa (gp160) and is cleaved to two glycoproteins, gp120 and gp41, which are the mature envelope glycoproteins in the virus. Neither the temporal and spatial features of glycosylation nor the oligosaccharide processing and proteolytic cleavage of the envelope glycoprotein are well understood. To understand more about these events, we investigated the glycosylation and cleavage of the envelope glycoproteins in the CD4+ human cell line, Molt-3, persistently infected with HIV-I (HTLV IIIB). The carbohydrate analysis of gp160 and gp120 and the behavior of the glycoproteins and glycopeptides derived from them on immobilized lectins demonstrate that both of these glycoproteins contain complex- and high-mannose-type Asn-linked oligosaccharides. In addition, the N-glycanase-resistant oligosaccharides of gp120 were found to contain N-acetyl-galactosamine, a common constituent of Ser/Thr-linked oligosaccharides. Pulse-chase analysis of the conversion of [35S]cysteine-labeled gp160 showed that in Molt-3 cells it takes about 2 h for gp120 to arise with a half-time of conversion of about 5 h. At its earliest detectable occurrence, gp120 was found to contain complex-type Asn-linked oligosaccharides. Taken together, these results indicate that proteolytic cleavage of gp160 to gp120 and gp41 occurs either within the trans-Golgi or in a distal compartment.
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PMID:gp160 of HIV-I synthesized by persistently infected Molt-3 cells is terminally glycosylated: evidence that cleavage of gp160 occurs subsequent to oligosaccharide processing. 189 96

Monocyte--macrophages are important target cells and reservoirs for HIV. The existing methods for the quantification of infectious virus in HIV stocks are not totally satisfactory for use with macrophage cultures. We have developed an infectious focus assay for the direct quantification of virions infectious for human peripheral blood monocyte-derived macrophages adhering to plastic microtitre plates. The combination of an HIV-1 p24-antigen-specific monoclonal antibody and a beta-galactosidase-linked second antibody resulted in a sensitive and very specific assay. With 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside as substrate, the assay proved to be as sensitive as p24 antigen quantification in culture supernatants.
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PMID:Direct quantification of HIV-1 infectivity for monocyte--macrophages using an infectious focus assay. 190 61

The delivery of the anti-HIV agent 3'-azido-3'-deoxythymidine (AZT), in its 5'-monophosphate form, (in) to human T-lymphocyte MT-4 cells in vitro through covalent coupling to neoglycoproteins was investigated. In vivo application of this drug targeting concept may lead to increased efficacy and/or diminished side effects caused by AZT during the treatment of AIDS and ARC patients. The rationale for the design of the neoglycoprotein carriers is based on the existence of sugar recognizing lectins on T-lymphocytes. Using a phenyl-linkage between sugar and Human Serum Albumin (HSA), various mannose-, fucose-, galactose-and glucose-containing neoglycoproteins were synthesized. The intrinsic anti-HIV activity of these neoglycoproteins was tested in vitro in HIV-1 infected MT-4 cells. Only the derivative having 40 moles mannose per mole protein (Man40HSA) shows pronounced anti-HIV-1 activity itself. This effect may be caused by interference of the Man40HSA with the gp120-CD4 mediated virus/MT-4 cell interaction. After conjugation with AZTMP, the mannose- as well as the fucose- and galactose-containing conjugates exhibited a pronounced activity. Conjugates of glucose-HSA and HSA displayed much less activity in spite of the fact that drug loading was considerably higher, compared with the galactose, mannose and fucose derivatives. In the series of mannose-neoglycoproteins, the Man22HSA-AZTMP conjugate was shown to be more than 30 times as active against HIV-1 compared to HSA-AZTMP. Selectivity indices of Man7 and Man22HSA-AZTMP were exceeding the AZT and AZTMP indices, indicating that these conjugates possess a more selective action. Stability experiments indicate that the potent action of the galactose-, mannose- and fucose-HSA-AZTMP conjugates is not due to a complete extracellular hydrolysis of the covalent drug-protein bond. Since Man22HSA has no intrinsic activity in the concentration range used, the antiviral effect is unlikely to be explained by synergism of the neoglycoprotein by a component of the cell membrane and subsequent internalization and release of the drug from the conjugate may play a role.
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PMID:Targeting of antiviral drugs to T4-lymphocytes. Anti-HIV activity of neoglycoprotein-AZTMP conjugates in vitro. 197 34

Two ring-expanded analogues (compounds 2 and 3) of the anti-HIV fermentation product oxetanocin A (1) were synthesized from commercially available diacetone D-glucose. Antiviral testing against HIV in ATH8 cells revealed that the ring-expanded analogue 2 possessed a similar activity profile as oxetanocin A. Neither compound, however, was capable of providing full protection to the cells against HIV infection. The isomeric ring-expanded analogue 3 was totally devoid of anti-HIV activity. Molecular modeling suggested that while oxetanocin A and compounds 2 and 3 share a large common substructure with the potent anti-HIV drug, dideoxyadenosine (ddA), the extra hydroxymethyl substituent may contribute negatively to the binding of these molecules to a critical enzyme. The negative contribution may be less important in oxetanocin and isomer 2 than in isomer 3. From these studies it would appear that both oxetane and tetrahydrofuran rings are equivalent templates to support the adenine base in terms of anti-HIV activity.
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PMID:A ring-enlarged oxetanocin A analogue as an inhibitor of HIV infectivity. 199 35

In order to investigate whether neoglycoproteins can potentially act as carriers for targeting of antiviral drugs to certain cell types in the body, various neoglycoproteins were synthesized using thiophosgene-activated p-aminophenyl sugar derivatives. These neoglycoproteins were conjugated with the 5'-monophosphate form of the antiviral drug AZT. For a proper characterization of these preparations, both protein and drug content have to be determined. Comparison of the Lowry and the Bio-Rad protein assays revealed that for both the neoglycoprotein carriers themselves and the AZTMP conjugates, the Lowry assay yielded the most reliable and reproducible results. It was demonstrated that both the reagent used for drug conjugation (ECDI) as well as the introduction of phenyl-sugar groups in the protein interfered with the analysis of bound nucleotide as based on spectral differences between protein and protein-drug conjugate. Therefore, we developed a rapid HPLC system for determination of the drug-protein coupling ratio through acid hydrolysis of the covalently bound nucleotide. With the ECDI-mediated conjugation of 5'-monophosphate drug derivatives to neoglycoproteins, products with molar ratios of drug to protein ranging from 1.2 to 5.6 were obtained. The drug-neoglycoprotein conjugates appeared to be fairly stable during storage, in lyophilized form, at -20 degrees C. The anti-HIV-1 activity of the neoglycoprotein-drug conjugates, as determined in vitro in MT-4 cells, was shown to be dependent on glycosylation of the albumin and also on the kind of sugar present in the neoglycoprotein. The anti-HIV-1 activity of the AZTMP-mannose-albumin conjugate exceeded that of the parent drug by more than 4 times.
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PMID:Neoglycoproteins as carriers for antiviral drugs: synthesis and analysis of protein-drug conjugates. 200 55

In this study we raised antibodies against Candida albicans mannans of serotype A and B which comprise mannose alpha(1----2)-and mannose alpha(1----3)-linked residues. These antibodies inhibited human immunodeficiency virus type IIIB (HIV-IIIB) infection of H9 cells in vitro; 5 micrograms/ml of antibodies against mannan from serotype A and 10 micrograms/ml of antibodies against serotype B mannan were sufficient to inhibit infection by almost 100 and 85%, respectively, after an incubation period of 4 days. During a prolonged incubation period (8-12 days), the amount of HIV particles (as measured by reverse transcriptase activity in the culture medium) increased again in assays with antibodies raised against serotype B, but only little in assays containing antibodies against serotype A. Applying the Western blotting technique and a novel enzyme-linked immunosorbent assay system it was established that the antibodies reacted with the gp120 of HIV-1 exclusively. Immunofluorescence inspection using a confocal laser scanning microscope revealed that the gp120 protein is exposed on the outer surface of H9 cells where it is recognized by the anti-mannan antibodies. These results indicate that mannan residues of C. albicans can serve as antigens to raise neutralizing antibodies against HIV infection.
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PMID:Antibodies against defined carbohydrate structures of Candida albicans protect H9 cells against infection with human immunodeficiency virus-1 in vitro. 205 8

We studied functional and immunohistochemical characteristics of cultured rat microglia. Unstimulated microglia did not proliferate. Microglia stimulated with LCM (L929 conditioned medium: colony stimulating factor-1) had proliferative activity and increased acid phosphatase activity. LPS (lipopolysaccharide) and IFN gamma (interferon-gamma) but did not affect proliferative activity. Immunohistochemically, RCA-1 lectin and GS-1 lectin, which react to beta-D-galactose and alpha-D-galactose respectively, strongly reacted to the cytoplasm and membrane of unstimulated microglia. After stimulation with LCM, microglia elongated processes and decreased response to these lectins. On the other hand, microglia stimulated with LCM showed increased reactivity to monoclonal antibody of vimentin. Microglia stimulated with LPS had round shape and had response to these lectins and vimentin. Microglia stimulated with IFN gamma had adhesive activity and weakly stained with these lectins but not with vimentin. ED-1 (monoclonal antibody of rat monocytes/macrophages) reacted to unstimulated and stimulated microglia. In flow cytometry, unstimulated microglia expressed OX-18 (MHC class I) and W3/25 (CD4) antigen. After stimulation with IFN gamma, microglia were induced to express these antigens. CD4 antigen is a marker of helper/inducer T cells and thought to be a receptor of HIV. The results that microglia had CD4 antigen which was further induced with IFN gamma are important to investigate infection of the CNS with HIV. OX-6 (Ia) antigen was induced with IFN gamma. This indicates that the microglia plays a central role in the CNS immune reaction. These characteristics of cultured rat microglia provide useful informations to investigate the pathogenesis of the CNS disorders.
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PMID:[Functional and immunohistochemical studies of cultured rat microglia]. 206 Feb 34

Three different human immunodeficiency virus type I (HIV-1) envelope derived recombinant proteins and the full length human CD4 polypeptide were expressed in Spodoptera frugiperda (Sf9) cells. DNA constructs encoding CD4, gp120, gp160, and gp160 delta (full length gp160 minus the transmembrane and cytoplasmic region of gp41) were cloned into the baculovirus expression vector pVL941 or a derivative and used to generate recombinant viruses in a cotransfection with DNA from Autographa californica nuclear polyhedrosis virus (AcMNPV). Western blotting of cell extracts of the recombinant HIV-1 proteins showed that for each construct two major bands specifically reacted with anti-HIV-1 envelope antiserum. These bands corresponded to glycosylated and nonglycosylated versions of the HIV proteins as determined by 3H-mannose labeling and tunicamycin treatment of infected cells. A time course of HIV envelope expression revealed that at early times post-infection (24 hours) the proteins were fully glycosylated and soluble in nonionic detergents. However, at later times postinfection (48 hours), expression levels of recombinant protein reached a maximum but most of the increase was due to a rise in the level of the nonglycosylated species, which was largely insoluble in nonionic detergents. Thus, it appears that Sf9 cells cannot process large amounts of glycosylated recombinant proteins efficiently. As a measure of biological activity, the CD4 binding ability of both glycosylated and nonglycosylated recombinant HIV envelope proteins was tested in a coimmunoprecipitation assay. The results showed that CD4 and the glycosylated versions of recombinant gp120 or gp160 delta specifically associated with one another in this analysis. Nonglycosylated gp120 or gp160 delta proteins from tunicamycin-treated cultures did immunoprecipitate with anti-HIV-1 antiserum but did not interact with CD4. We conclude that production of native HIV envelope proteins, as measured by addition of carbohydrate side chains and ability to bind CD4, peaks early after infection in baculovirus-infected insect cells.
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PMID:Temporal expression of HIV-1 envelope proteins in baculovirus-infected insect cells: implications for glycosylation and CD4 binding. 207 45


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