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Biomedical subjects

E Neter

Publications and source records attributed to E Neter.

At least 91 records · Page 5Linked to original sources
PubMed1970

Specific inhibition of endotoxin coating of red cells by a human erythrocyte membrane component.

We have isolated from human erythrocyte ghosts a fraction which prevents the attachment of unheated as well as heated lipopolysaccharides of gram-negative bacteria to red cells. This material has no significant inhibitory effect either toward the Vi antigen of gram-negative bacteria or towards the group and common antigens of the gram-positive bacteria investigated. We, therefore, named this fraction "lipopolysaccharide receptor." The receptor interacts with lipopolysaccharides and not with erythrocytes, it forms complexes with and blocks those groupings of lipopolysaccharides which attach to red cells. The effect of the receptor is physical and not enzymatic. The interaction of the receptor with the lipopolysaccharides is reversible, and the receptor removes lipopolysaccharides fixed to red cells. An equilibrium of lipopolysaccharide distribution between cells and receptor is established when receptor-lipopolysaccharide complexes are incubated with red cells. The receptor is labile toward heat and deviation of the hydrogen ion concentration from neutrality; aldehydes destroy its inhibitory activity.

Journal Article↗
PubMed1970

Chlorphenesin: an antigen-associated immunosuppressant.

Chlorphenesin (3-p-chlorophenoxy-1,2-propanediol), when injected intravenously together with either of two common bacterial antigens, inhibits the antibody response of the rabbit. The antigens studied are those common to Enterobacteriaceae and to gram-positive bacteria. The immunosuppression is contingent upon incubation of chlorphenesin and antigen in vitro prior to administration, since separate injection of antigen and inhibitor or of mixtures without prior incubation yields undiminished antibody response. Chlorphenesin, as shown by hemagglutination-inhibition tests, does not alter the antigenic determinants, because antibody neutralization occurs in the presence or absence of the drug. The immunosuppressive effect is reversible, since precipitation of chlorphenesin at 4 C substantially restores immunogenicity. Animals immunized with antigen-drug mixtures, which fail to respond with significant antibody production, nonetheless are immunologically primed. It is concluded that chlorphenesin represents another example of antigen-associated immunosuppressants.

Journal Article↗
PubMed1970

Production of common antigen by enteric bacteria grown in a synthetic culture medium.

Enterobacteriaceae share a common antigen (CA). The present investigation was carried out to determine whether this antigen is produced by representative strains of Escherichia, Salmonella, and Serratia grown in a completely synthetic medium. For comparative purposes, antigen production by the same strains grown in infusion broth was determined. CA, as assayed by indirect hemagglutination and immunogenicity studies in the rabbit, was produced by the microorganisms cultured in both media. The amount of CA produced by the strains varied according to the size of microbial population and to the length of culture. With the exception of E. coli O14, the strains studied, on day 7, produced 1.4 to 8 times more CA in infusion broth than in the synthetic medium; with E. coli O14, the ratio of CA in the respective media was 96:1. E. coli O14, but not E. coli O111 or S. typhimurium, when grown in the synthetic medium, engendered CA antibodies upon intravenous injection into rabbits. Ethanol extraction of the latter two strains yielded an immunogenic ethanol-soluble antigen preparation. The ethanol-soluble fraction of E. coli O111 also induced a secondary response in animals primed with E. coli O111 or S. typhimurium cultures grown in the synthetic medium. It is concluded that CA produced in a completely synthetic culture medium has the same attributes as CA produced in infusion broth.

Journal Article↗
PubMed1969

Antigen-associated immunosuppressant: effect of serum on immune response.

Serum from various animal species, including the test animals themselves, inhibits the antibody response of the rabbit to two bacterial antigens, provided that antigen and immunosuppressant interact prior to injection. The degree of immunosuppression is related to the length of incubation in vitro of antigen and serum. Serum does not hinder or destroy the antigenic determinant. Bacterial antibodies do not account for inhibition of the antibody response. Antigen-associated serum components, as yet unidentified, may affect the early events of the immune response.

Animals↗