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Biomedical subjects

G Russ

Publications and source records attributed to G Russ.

At least 73 records · Page 4Linked to original sources
PubMed1983

Human cell surface proteins selectively assembled into vesicular stomatitis virus virions.

Vesicular stomatitis virus (VSV) selectively assembled proteins from human cells into progeny virions. These proteins can be surface labeled before infection with 125I, and when purified virus was examined by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis, only two or three bands of proteins (Mr around 100K) were seen. Antisera to these proteins were produced, using as immunizing antigen VSV tsO45 mutant, defective in assembly of G protein, which had been made at the nonpermissive temperature in the three human tumor cell lines, HeLa (cervical carcinoma), T47D (breast carcinoma), and HMB2 (melanoma). After absorption with wild-type VSV, each of the antisera displayed a different pattern of reactivity; at least three antigenic specificities were detected. Two of them, corresponding to antigens selected by VSV from HeLa and T47D, were to some extent related and they showed an association mainly with epithelial cell-derived gynecological tumors, but they were absent in carcinomas of lung or of digestive tract. These (or related) antigens were expressed in a lower level in some normal tissues, mainly in ovaries. Antigen(s) assembled by VSV from the melanoma cell line was entirely different and appeared to be associated with cell growth. The grounds for selective assembly of these specific proteins by VSV are not clear; they either share with viral surface glycoproteins some physical or structural properties, which are critical for incorporation into the viral envelope, or conceivably they even may represent uncleaved precursor proteins coded by env genes of incomplete genomes of endogenous human retroviruses.

Antigens, Neoplasm↗
PubMed1983

Production of monoclonal antibodies with haemagglutination-inhibition activity to the Skalica strain from the tick-borne encephalitis complex.

Hybridomas secreting monoclonal antibodies with haemagglutination-inhibition (HI) activity to the Skalica strain of tick-borne encephalitis (TBE) complex were prepared by the fusion of P3-NS1-Ag4-1 myeloma cell line with spleen cells of BALB/c mice immunized with the purified Skalica strain. The highest titres of monoclonal antibodies obtained from the hybridomas S-9, S-15 and S-16 ranged from 512 to 10,240, respectively; the ascitic fluid contained as many as 4.6 mg/ml of monoclonal antibodies. Its analysis by Ouchterlony's double immunodiffusion, agarose electrophoresis, and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) revealed the presence of monoclonal antibodies with mu isotype of the heavy and kappa isotype of the light chain. The specificity of the monoclonal antibodies was proved using 11 different antigens from family Togaviridae in the HI test.

Animals↗
PubMed1983

Vesicular stomatitis virus phenotypically mixed with retroviruses: an efficient detection method.

Two methods of assaying vesicular stomatitis virus (VSV) particles phenotypically mixed with retrovirus-coded antigens were compared. Each of them detected phenotypically mixed particles with different minimum proportion of surface glycoprotein molecules of the donor virus, and consequently also profoundly different proportions of VSV virions containing retrovirus antigens. Only a low proportion (10(-4) of VSV virions grown in XMuLV-infected rabbit SIRC cells behaved as pseudotypes, resistant to anti-VSV serum and neutralized by anti-XMuLV serum. VSV produced in mouse L cells did not contain significant titre of pseudotype particles in the neutralization test. However, when immunoprecipitation was used with corresponding antibody and Staphylococcus aureus cells, almost 100% of the VSV virions produced in L cells and in XMuLV-preinfected SIRC cells were found to contain MuLV-related antigen molecules.

Animals↗
PubMed1983

Use of monoclonal antibodies against avian retroviral protein p19 for competitive radioimmunoassay and immunodiffusion.

Monoclonal antibodies were used in competitive binding assays to investigate the arrangement of three epitopes on the protein p19 of avian myeloblastosis virus (AMV). It was reasoned that if the epitopes recognized by two monoclonal antibodies are physically close, the binding of one antibody will sterically block the binding of the second; conversely no blocking will occur if the epitopes are sufficiently distant. The results of these competitive binding assays demonstrated the presence of two distinct antigenic sites on the protein p19. Monoclonal antibodies against the protein p19 of AMV were tested also in gel double immunodiffusion. Since the p19 protein has strong tendency to aggregate, it was not surprising, that clear precipitin lines with these monoclonal antibodies were obtained.

Animals↗
PubMed1983

Production and characterization of monoclonal antibodies against avian myeloblastosis virus.

Hybridomas were prepared by fusion of mouse myeloma cell line Sp2/0 with lymphocytes from mice immunized with avian myeloblastosis virus (AMV). The specificity of each monoclonal antibody was characterized by radioimmunoassay (RIA) using purified viral core proteins, immunoprecipitation of radioactively labeled virus (35S-methionine-labeled AMV, 125J-labeled AMV) and immunoblotting. One monoclonal antibody (IC11) which is of IgG1 subclass, and two other monoclonal antibodies (IF9 and IB8), both of IgG3 subclass, were directed against the p19 protein of AMV. The remaining eight monoclonal antibodies (most of them of IgM class) did not precipitate viral proteins under the experimental conditions used, except IIG12 hybridoma antibody which irregularly precipitated glycoprotein gp85. Since most of them (seven, including IIG12) gave positive reactions in RIA with antigenically unrelated influenza virus, these monoclonal antibodies were directed against virus components specified by chick cells (host cell antigen).

Animals↗
PubMed1982

Antigenic relatedness of alphaherpesviruses isolated from free-living rodents.

Complement fixation and virus neutralization tests confirmed that alphaherpesviruses isolated from free-living Apodemus flavicollis and Clethrionomys glareolus rodents form an antigenically identical or very close group. Immunofluorescence showed that antigen assembly and distribution within the infected cell resembles that of members of the Alphaherpesvirinae subfamily. Radioimmunoassay revealed close antigenic relatedness between five rodent herpesvirus isolates. Moreover it suggested a possible relatedness of these viruses to some virus species isolated from humans and animals.

Animals↗
PubMed1980

The cell growth inhibitory and antiviral effects of interferon in cloned transformed mouse cells.

Eight clones and two subclones of SV40- and seven clones and one subclone of 20-methylcholanthrene-transformed C3H mouse embryonic fibroblasts were compared in tests for sensitivity to the antiviral and cell-growth inhibitory activities of a partially purified mouse L-cell interferon. While the sensitivity of clones and subclones to the antiviral activity of interferon was comparable to that of parent lines, the cell-growth inhibitory activity of interferon in the SV40 clones showed more than 100-fold variation and the methylcholanthrene-transformed cells could be divided into two groups in this respect. No correlation of sensitivity to the cell-growth inhibitory effect of interferon with the chromosome number, interferon-producing capacity or tumorigenicity of the clones could be detected. However, the cells of the interferon-sensitive clones No. 36 of the methylcholanthrene-transformed line were destroyed by macrophages at higher percentage binding of 125I-labeled soybean lectin. These results suggest that (1) the cell-growth inhibitory effect of interferon might be mediated by a specific type of receptors, and (2) N-acetyl-galactosamine present on the surface of interferon-resistant cells in a higher concentration than on interferon-sensitive cells hinders the recognition of cells both by macrophages and by interferon.

Animals↗
PubMed1980

Radioimmunoassay of influenza A virus haemagglutinin. II. Antigenic cross-reactions of influenza A (H3 subtype) viruses as determined by radioimmunoassay and haemagglutination inhibition tests.

Individual rabbits differed greatly in their antibody response to the "strain-specific" and "cross-reactive" antigenic determinants on the haemagglutinin (HA) subunit of influenza virus recombinant MRC11 (H3N2) and influenza virus Dunedin (H3N2), after immunization with whole virus or bromelain-released haemagglutinin (B-HA). Consequently, diverse cross-reactions between htese viruses and A/Hong Kong/68 virus were found in the haemagglutination inhibition (HI) test as well as in homologous radioimmunoassay (125I-B-HA from MRC11:anti MRC11 serum, and 125I-B-HA from Dunedin: anti Dunedin serum) when sera from different animals were employed. Radioimmunoassay (RIA), over and above to the HI test, was able to differentiate clearly the respective HAs also with antisera reacting to the same HI titre with both corresponding influenza virus strains. Thus it appeared that antigenic differences could be identified with higher sensitivity by homologous RIA than by the HI test and that multiple antigenic determinants were reactive on the 125I-B-HA in the RIA procedure employed. MRC11 and A/HK/68 viruses were also compared by heterologous RIA (125I-B-HA from MRC11: anti A/HK/68 serum). It was found that preferentially antigenic determinants with a high degree of cross-reactivity could be studied in the heterologous system.

Animals↗
PubMed1979

Antigenic glycopolypeptides HA1 and HA2 of influenza virus haemagglutinin. III. Reactivity with human convalescent sera.

The immune reactivity to both haemagglutinin glycopolypeptides HA1 and HA2 [prepared from bromelain-released haemagglutinin of influenza virus A/Dunedin/4/73 (H3N2)], was demonstrated by both gel double immundiffusion and radioimmunoassay in human convalescent sera obtained after natural infection during influenza epidemics in 1974/75 and 1976/77. In gel double immunodiffusion, the precipitin line(s) corresponding to glycopolypeptide HA1 were always more distinct than precipin line(s) corresponding to glycopolypeptide HA2. In radioimmunoassay, human convalescent sera revealed higher titres for binding of 125-I-labelled HA2 than for 125-I-labelled HA1. Characterization of human convalescent sera was completed by haemagglutination-inhibition test.

Antibodies, Viral↗
PubMed1979

Antigenic glycopolypeptides HA1 and HA2 of influenza virus haemagglutinin. IV. Immunogenic properties of separated haemagglutinin glycopolypeptides.

Highly purified haemagglutinin glycopolypeptides HA1 and HA2 were effective in eliciting an antibody response. HA2 had a markedly greater immunogenic potential than HA1. In gel double immunodiffusion, sera from rabbits immunized with HA2 produced more distinct precipitin lines than sera obtained by immunization with HA1. Both kinds of rabbit sera gave precipitation with homologous antigen and with bromelain-released and purified haemagglutinin (B-HA). In radioimmunoassay, sera from rabbits immunized with HA2 revealed considerable titres for 125I-labelled HA2 binding and reacted preferentially with 125I-labelled HA2. In general, sera from rabbits immunized with HA1 exhibited low titres for 125I-labelled HA1 binding: usually they reacted also with 125I-labelled B-HA and 125I-labelled HA2. Only rabbits injected with a few doses of HA1 at short intervals revealed preferential binding for 125I-labelled HA1. Glycopolypeptides HA1 and HA2 failed to induce haemagglutination-inhibiting and virus neutralizing antibodies in rabbits.

Animals↗
PubMed1979

Use of Staphylococcus aureus for rapid radioimmunoassay of influenza A virus haemagglutinin.

In a rapid method for the radioimmunoassay (RIA) of influenza A virus haemagglutinin, Staphylococcus aureus (strain Cowan I, Czechoslovak State Collection No Mau 55/64) was used for separation of bound and free antigens. With rabbit and human immune sera, the binding of antigen-antibody complexes to heat-killed, formalin-fixed staphylocci was comparable to the double antibody technique. The time required for the completion of binding reaction was about 10 min compared to 18--24 hr required for double antibody precipitation. S. aureus did not bind directly (i.e. in the absence of specific antibody) a significant amount of radiolabelled antigen.

Animals↗
PubMed1978

Radioimmunoassay of influenza A virus haemagglutinin. I. Preparation and properties of radioactive 125I-labelled bromelain-released haemagglutinin.

Haemagglutinin released from influenza A virus recombinant MRC11 [antigenically identical to the strain A/Port Chalmers/1/73 (H3N2)] by bromelain treatment and purified by rate zonal centrifugation (further on B-HA) was examined for eventual contamination by neuraminidase. According to specific enzymatic activities corresponding to MRC11 virus and B-HA alone respectively, B-HA contained less than 0.1% of enzymatically active neuraminidase orginally present in the virus. Gel double diffusion tests, specifities of rabbit antisera induced by B-HA, as well as radioimmunoprecipitation experiments demonstrated that B-HA was devoid of any antigenically active neuraminidase. Precipitation of 125I-labelled B-HA with antisera to influenza virus recombinants with N2 neuraminidase has been evidently caused by antibodies to host antigenic determinaant(s) present in these sera. With respect to purity as well as radioimmunoprecipitation properties, B-HA is quite suitable for radioimmunoassay experiments.

Antibodies, Viral↗
PubMed1978

Marked difference in electrophoretic migration rates between two influenza A viruses.

Comparative moving boundary electrophoresis revealed that influenza virus A/PR/8/34 (H0N1) has a 2.5 times higher electrophoretic migration rate at pH 7 than influenza virus A/Singpore/1/57 (H2N2). This difference was the same whether the compared viruses were purified first by either ammonium sulphate precipitation or adsorption onto and elution from red blood cells and then by density gradient centrifugation. The same electrophoretic methods was used for testing the homogeneity of influenza virus preparations purified by either method.

Centrifugation, Density Gradient↗