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D L Tyrrell

Publications and source records attributed to D L Tyrrell.

86 records · Page 5Linked to original sources
PubMed1980

Isolation and immunological characterization of the nucleocapsid and membrane proteins of measles virus.

Measles virus nucleoprotein (NP) and matrix (M) components were purified by two different procedures. Antigens were prepared by sedimenting material from 1% Cutscum extracts of infected cells into the interphase between 65 and 40% sucrose and further fractionation of the interphase material in a linear CsCl gradient, density range 1.20 to 1.33 g/ml. NP components contaminated with some M material and cellular actin banded at 1.30 to 1.32 g/ml, but at the low density range of 1.20 to 1.22 g/ml pure M component was demonstrable. Partially denatured antigens were obtained by elution of the 60K NP and 36K M polypeptides after SDS-polyacrylamide slab gel electrophoresis. Rabbit hyperimmune sera were prepared against both purified antigens and isolated polypeptides. All sera reacted only with homologous antigen except the antiserum against NP components isolated from CsCl gradients, which also contained antibodies to the M component. Antibodies against NP antigen stained both intranuclear inclusions and cytoplasmic material in immune fluorescence tests. In contrast, antisera against M antigen only stained the cytoplasm. Since intranuclear nucleocapsids are smooth, whereas intracytoplasmic nucleocapsids are 'fuzzy', this may infer that the fuzziness, at least in part, is caused by M antigen adhering to nucleocapsid components.

Capsid↗
PubMed1979

Transmembrane communication in cells chronically infected with measles virus.

The transmembrane association of the measles virus hemagglutinin and hemolysin surface proteins with intracellular viral antigens was studied. Rabbit antisera monospecific for measles virus matrix and nucleocapsid proteins and a human antiserum containing specificities for both the hemagglutinin and hemolysin proteins were used to study the co-capping of these proteins in human Lu 106 cell-line, chronically infected with measles virus. Capping of the surface-associated envelope components was accompanied by co-capping of the matrix and nucleocapsid proteins, the latter being localized mainly within the inclusions. This demonstrated transmembrane communication between surface-associated envelope components and the intracellular measles virus matrix and nucleocapsid proteins. The results demonstrated the existence of a linkage between viral inclusions and viral proteins associated with cell membranes. In the presence of cytochalasin B (1--2 micrograms/ml), co-capping of the matrix protein was unchanged or slightly enhanced, whereas co-capping of the nucleocapsid protein decreased, indicating that actin filaments may mediate the communication between viral nucleocapsids and the cell membrane.

Antigens, Surface↗
PubMed1978

Actin filaments in paramyxovirus-infected human fibroblasts studied by indirect immunofluorescence.

Fibroblasts growing on glass have microfilaments arranged in bundles. These can be demonstrated by indirect immunofluorescent technique using human antiactin serum or experimentally produced rabbit anti-actin serum. When monolayer cultures of epithelial cells and fibroblasts are infected with paramyxovirus, such as measles, mumps, Sendai and NDV, there is a striking decrease of the bundles. Rabies and adenoviruses do not seem to influence the staining of microfilaments. The microfilament decreasing effect in the cells correlates to the finding by SDS-polyacrylamide-gel-electrophoresis of actin within virions of the paramyxoviruses.

Actins↗
PubMed1978

Electrophoresis of immunoglobulin G. Facilitated migration of minute amounts in agarose.

Migration of very small amounts of immunoglobulin (20 ng) is restricted in agarose electrophoresis. Incorporation of a stable protein matrix (rabbit gamma globulin 1 mg/ml) in the agarose permits unrestricted migration so that immunoelectrophoresis of this quantity of radiolabelled antibody is possible. Very small amounts of radiolabelled and non-radiolabelled antibody were subjected to successful crossed immunoelectrophoresis through barriers of antigen under conditions which provide favorable ratios of antibody to antigen. These methods should be useful for studies of antibody eluted from tissue in acquired and autoimmune diseases associated with tissue bound immunoglobulin.

Animals↗
PubMed1978

Structural polypeptides of measles virus.

The structural polypeptides of two strains of measles virus grown in Vero cells were analysed in SDS-PAGE slab gels. Six major polypeptides were identified with mol. wt. of 79000, 72000, 60000, 43000, 40000 and 36000. The largest polypeptide was sensitive to trypsin digestion and was the dominant glycosylated polypeptide identified when the virus was grown in medium containing 3H-fucose or 3H-glucosamine or when the virus was treated with galactose oxidase and labelled with 3H-sodium borohydride. It is concluded that the 79000 mol. wt. polypeptide represents the haemagglutinin. Treatment with non-ionic detergent removed this polypeptide and also the 40000 mol. wt. polypeptide from the virus envelope. The 40000 mol. wt. polypeptide is probably associated with haemolysin and cell fusion activities and is analogous to the F1 of paramyxoviruses. A polypeptide of mol. wt. approx. 20000 detected after glycoprotein labelling may represent the F2 of measles virus. The 43000 mol. wt. polypeptide co-migrates with cellular actin and is the only major measles polypeptide that is heavily labelled when the virus is grown on Vero cells prelabelled with 35S-methionine. Thus it may represent cellular actin incorporated into the virus during maturation. The quantity of the 72000 mol. wt. polypeptide relative to the other major polypeptides varied considerably in different virus preparations. The role of the polypeptide could not be defined. By analogy with previously published data the 60000 and 36000 mol. wt. polypeptides are inferred to represent nucleocapsid and membrane proteins, respectively.

Glycoproteins↗
PubMedDate not supplied

In vitro anti-hepatitis B virus activities of 5"-O-myristoyl analogue derivatives of 3"-fluoro-2",3"-dideoxythymidine (FLT) and 3"-azido-2",3"-dideoxythymidine (AZT).

PURPOSE: The objective of this study was to evaluate a dual action prodrug concept wherein an unnatural myristic acid analogue is coupled via an ester moiety to the 5'-position of FLT or AZT. Subsequent intracellular cleavage of the prodrug ester would simultaneously release FLT or AZT that could inhibit reverse transcriptase (RT), and the myristic acid analogue that could inhibit myristoyl-CoA:protein N-myristoyltransferase (NMT). METHODS: Cytotoxicity (2.2.15 cell culture), and anti-hepatitis B activity of 5'-O-myristoyl analogue prodrug derivatives of FLT and AZT (2-8) were evaluated in vitro using human liver hepatitis B virus (HBV) producing 2.2.15 cell lines. RESULTS: The 5'-O-(12-methoxydodecanoyl) ester derivatives of AZT (2, EC(50) = 2. 7 +/- 0.3 microM; CC(50)= 727 +/- 19 microM) and FLT (4, EC(50)= 2.8 +/- 0.3 microM; CC(50)= 186 +/- 20 microM) were the most effective anti-hepatitis B virus (anti-HBV) compounds of this series in a replication assay. In the series of 5'-O-myristic acid analogue ester prodrug derivatives of FLT, the relative anti-HBV potency order was MeO(CH(2))(11)CO(2)- > N(3)(CH(2))(11)CO(2)- and Br(CH(2))(11)CO(2)- > EtS(CH(2))(n)CO(2)- (n = 10 or 11) > Me(CH(2))(12)CO(2)- (myristoyl). CONCLUSIONS: The in vitro data suggest that the 5'-O-myristoyl analogue prodrug concept offers a potential drug design approach to design dual acting antiviral agents, with superior pharmacokinetic, biodistribution, reduced cytotoxicity and/or increased efficacy. In this regard, the 5'-O-(12-methoxydodecanoyl) prodrug ester of 3'-thia-3'-deoxythymidine (3TC) may offer the greatest potential for the treatment of HBV infection.

Acyltransferases↗