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Biomedical subjects

G Hunsmann

Publications and source records attributed to G Hunsmann.

At least 235 records · Page 13Linked to original sources
PubMed1980

Search for mammalian type-C retrovirus polypeptides on infected animal cells and human tumor cell lines using interspecies-reacting antibodies.

Cells producing endogenous and exogenous type-C retroviruses of murine, feline and primate origin were evaluated for expression of those virus-specific cell-surface antigens which cross-react with antibodies to interspecies determinants of mammalian type-C viral polypeptides. Surface polypeptides of cells replicating endogenous and exogenous type-C retroviruses were iodinated by the lactoperoxidase method. Labelled antigens were immunoprecipitated and analyzed in polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. This method detected gp71 and less frequently p15E/p12E on the surface of virus-producing cells; in addition, p27 was found on F422 cells replicating feline leukemia virus. Antibodies to the membrane protein p15E displayed the broadest cross-reactivity but only antibodies to gp71 mediated complement-dependent interspecies cell lysis. The pattern of cross-reactivity reflected known genetic relationships among these mammalian viruses. Although antiserum to the simian sarcoma virus complex (SSV) was strongly cytotoxic to some human tumor cell lines, this reactivity could not be attributed to antibodies cross-reacting with SSV gp71.

Animals↗
PubMed1979

Rosettes from Friend leukemia virus envelope: preparation and physicochemical and partial biological characterization.

Rosette-shaped particles mainly containing gp85 were isolated from Friend leukemia virus. The isolation procedure comprised lysis of the virion by Triton X-100, affinity chromatography on concanavalin A-Sepharose, and velocity sedimentation. The rosettes displayed a mean sedimentation constant of 32S and a buoyant density of 1.21 g/ml. They contained 1% Triton X-100 and about 2% phospholipid. gp85 was identified by polyacrylamide electrophoresis, staining with periodic acid-Schiff reagent, and immunoprecipitation with antisera against Friend leukemia virus gp71 and p15(E). Rosettes completely blocked the cytotoxicity of the gp71 antiserum. The ability to hemagglutinate was inhibited by antibodies to gp71.

Chromatography, Affinity↗
PubMed1978

Surface expression of murine leukemia virus structural polypeptides on host cells and the virion.

The expression of murine leukemia virus structural polypeptides on the surface of cells producing exogenous Friend leukemia virus, endogenous ecotropic AKR and xenotropic BALB/c virus was investigated. Antisera to Friend virus gp71, p30, p15E, p12 and p10 were employed in a complement-dependent chromium release assay and to immunoprecipitate lactoperoxidase iodinated surface polypeptides prior to analysis in polyacrylamide gel electrophoresis. With the latter technique gag-gene encoded proteins and their precursors were not discovered on the viral and cellular surface membranes. Only env-gene encoded polypeptides gp85, gp71, and p15E were detectable. p15E is embedded into the lipid membrane. gp85 is formed by disulfide linkage of p15E to surface-exposed gp71. The ratio of gp71 to gp85 is variable and apparently determined by the host cell. Antibodies of strong cytotoxicity are those against type- and group-specific epitopes of gp71 as well as type-specific epitopes of p12.

Antibodies, Viral↗
PubMed1977

[Structural proteins of C-type RNA tumor viruses. Properties and significance for tumor immunity].

Five main structural polypeptides of Friend murine leukemia virus, a typical C-type RNA tumor virus, have been isolated. Their localization within the particle was attempted. They range from 10,000-71,000 in molecular weight and display three kinds of immunological determinants. The major envelope glycoprotein binds to cellular receptors and elicits the formation of antibodies which neutralize the virus and kill virus producing tumor cells in vitro. Natural as well as artificial immunity to this component protects mice against virus induced leukemia.

Animals↗
PubMed1975

Morphological, chemical, and antigenic organization of mammalian C-type viruses.

New features in the architecture of mammalian type C viruses, in particular knoblike surface projections and hexagonally arranged subunits on the core shell could be demonstrated by electron microscopy, taking advantage of newly developed preparation techniques. As examples, murine leukemia viruses (MuLVs) and newly isolated porcine and bovine C viruses are presented. The major proteins of a MuLV were isolated and partially characterized in chemical terms and with respect to their serological and other biological activities, such as interfering and hemagglutinating (HA) capacity. Most of the characterized proteins could be localized in particular substructures of the virion either by selective removal or isolation of electron microscopically identifiable constituents. The information obtained allowed the design of a more detailed model of mammalian C viruses. Special attention was devoted to the further characterization of interspecies antigens of mammalian C viruses. Different antigenic determinants were revealed. Their distribution allows further subgrouping of mammalian C viruses.

AKR murine leukemia virus↗