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Biomedical subjects

D O White

Publications and source records attributed to D O White.

At least 55 records · Page 3Linked to original sources
PubMed1980

Antigenic determinants of influenza virus hemagglutinin. V. Antigenicity of the HA2 chain.

All the polypeptide fragments obtained by cyanogen bromide cleavage of the hemagglutinin from A/Memphis/102/72 influenza virus were examined for their ability to bind to IgG raised against purified virus. Within the hemagglutinin heavy chain the only fragment displaying antigenicity is HA1CN1, which comprises the amino-terminal 168 amino acid residues. By the use of a sensitive radioimmunoassay in which the antigen is unlabeled, it was shown that the light chain is also antigenic. Inhibition studies have localized the activity to the HA2CN1 region, which comprises the carboxy-terminal 90 amino acids. The determinant on HA2 is shown to be subtype specific.

Antibodies, Viral↗
PubMed1979

Antigenic determinants of influenza virus hemagglutinin. II. Antigenic reactivity of the isolated N-terminal cyanogen bromide peptide of A/Memphis/72 hemagglutinin heavy chain.

Gel filtration of a cyanogen bromide digest of pure intact hemagglutinin from A/Memphis/102/72 influenza virus allowed the isolation of a variety of fragments. One of these fragments consists of three cyanogen bromide peptides (CNl and CN3 from HA1, and CNl from HA2) which remain linked together by disulphide bonds. This fragment was found to be antigenically active, as it was able to form antigen-antibody complexes (detected by affinity chromatography of radioiodinated peptide-IgG mixtures on protein A-Sepharose) with IgG directed against the protein moiety of viral hemagglutinin. The three cyanogen bromide peptides present in this disulphide-linked fragment were separated by gel filtration, carried out under reducing conditions, and tested for antigenic activity after controlled reoxidation of the individual peptides. Only one cyanogen bromide peptide, CNl from HA1, showed significant binding to antibody. The results indicate that antigenic activity of A/Mem/1O2/72 hemagglutinin resides within the N-terminal 170 amino acid residues of the hemagglutinin heavy chain.

Antibodies, Viral↗
PubMed1979

Comparison of natural killer cells induced by Kunjin virus and Corynebacterium parvum with those occurring naturally in nude mice.

Natural killer (NK) cells are rapidly elicited in the spleen and peritoneal cavity of mice inoculated intravenously or intraperitoneally with live Kunjin virus, and more slowly in the peritoneal cavity of mice inoculated intraperitoneally with Formalin-inactivated Corynebacterium parvum. NK cells induced by either agent display cytotoxicity for a similar spectrum of syngeneic, allogeneic, and xenogeneic cultured cell lines. By contrast, the cells occurring naturally in the spleen of congenitally athymic (nude) mice show substantially lower NK activity and are cytotoxic for a more restricted range of target cell lines. The distinction suggests that there may be more than one type of NK cell or that activation enhances the cytotoxicity and perhaps broadens the range of target specificity of endogenous NK cells.

Animals↗
PubMed1979

In vitro antibody response to influenza virus. I. T cell dependence of secondary response to hemagglutinin.

A good secondary IgG response to the hemagglutinin (HA) of influenza virus has been obtained in vitro in Marbrook-type cultures of influenza-primed mouse spleen cell suspensions stimulated with inactivated influenza virus. Anti-HA antibody was quantitated by a solid phase radioimmunoassay (RIA) by using purified HA as substrate. The T dependence of this secondary response was shown by depletion of T cells and reconstitution with a source of primed or unprimed T cells. The help given by T cells primed to the homologous virus was many times greater than that given by unprimed T cells, although the latter was significant. The system described will allow investigation of the specificity requirements of helper T cells engaged in the anti-HA response.

Animals↗
PubMed1978

Fc receptors induced by herpes simplex virus. I. Biologic and biochemical properties.

Radioiodinated normal rabbit IgG was used to detect Fc receptors on the surface of HeLa S3-2 cells infected with herpes simplex virus (HSV). Unlike the Fc receptors present on most leukocytes, these virus-induced Fc receptors were found to be sensitivite to trypsin at concentrations of enzyme as low as 0.1 mg/ml. Treatment of infected cells with neuraminidase enhanced the binding of IgG. Yet the HSV-induced Fc receptor(s) is probably a glycoprotein because its synthesis was inhibited by 2-deoxy-D-glucose at concentrations inhibiting glycoproteins but not total proteins. Binding of radioiodinated IgG to Fc receptors on infected HeLa S3-2 cells was unaffected by F(ab')2 fragments prepared from antisera against uninfected HeLa S3-2 cells or against human beta2-microglobulin. By contrast, anti-HSV F(ab')2 or Fab' fragments decreased binding of radioiodinated IgG to HSV-infected cells by 85%, and binding of radioiodinated Fc was also inhibited by anti-HSV Fab'.

Animals↗
PubMed1977

Two cytotoxic cells in peritoneal cavity of virus-infected mice: antibody-dependent macrophages and nonspecific killer cells.

Two new types of cell-mediated immune cytolysis of togavirus-infected cells are compared. The peritoneal cavity of mice 2 days after infection contains a nonadherent, non-phagocytic, non-O-bearing, trypsin-resistant, EDTA-sensitive cell displaying broadly specific cytotoxicity for uninfected or virus-infected syngeneic or xenogeneic cell lines. Peritoneal macrophages from normal mice are cytotoxic to infected target cells sensitized with minute amounts of homologous antiviral IgG.

Animals↗
PubMed1976

Cytotoxic macrophages: a rapid nonspecific response to viral infection.

In vitro and in vivo assays have been developed to study the relative contributions of various types of immune cytolysis in the destruction of infected cells after Semliki Forest virus infection of BALB/c mice. Highly cytotoxic activated macrophages, not specific for the infecting virus, appear on day 1, peak on day 2 to 3, and disappear within a week. Specifically sensitized T cells appear around day 3, peak on day 6, and disappear within a month. Cytotoxic antibody appears on day 4 and reaches high titers by day 8. Immune spleen cells greatly reduce the yield of virus from cultured cells. Infected cells rapidly disappear after transfer to infected animals.

Animals↗
PubMed1975

Protection of mice against cancer by immunization with membranes but not purified virions from virus infected cancer cells.

The life span of C57/Bl mice inoculated with Lewis lung carcinoma cells was prolonged if the mice were pre-immunized with membranes from these cells infected in vitro with influenza virus. Likewise, BALB/c mice were protected against the malignant tumour WEHI-11 by prior immunization with extracts of cultured WEHI-11 cells which had been infected with influenza virus or Semiliki Forest virus (SFV). Partially purified SFV grown in WEHI-11 cells also protected mice from cancer grafts but neither highly purified SFV nor the glycoprotein from the envelope of this virus protected the mice. It is concluded that SFV-induced immunopotentiation against cancer is not due to covalent linkage of tumour specific transplantation antigen (TSTA) to viral envelope protein but more probably is due to the apposition of viral glycoprotein and cellular TSTA in the plasma membrane of the cancer cell.

Animals↗
PubMed1971

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Australia↗