Biomedical subjects

D Wachsmann

Publications and source records attributed to D Wachsmann.

22 records · Page 2Linked to original sources

PubMed1989

Human IgG and Streptococcus mutans SR protein contain cross-reactive epitopes.

Antigen B, a glycoprotein present on the cell surface of "mutans streptococci," mediates bacterial adherence to teeth surfaces and has been implicated in cross-reactivity with human heart components. Elevated levels of anti-IgG antibodies were generally found in sera of rabbits immunized with protein SR, a B-related protein from Streptococcus mutans serogroup f, or recombinant protein SR (rSR). These anti-IgG antibodies could be involved in the previously mentioned heart cross-reactivities. Results from immunoblots and ELISA analyses demonstrate that these anti-IgG antibodies recognize common epitopes on SR, rSR, and human IgG2 and IgG4 probably located on the Fab region. Furthermore, control experiments with biotinylated human IgG show that the cross-reactions between IgG and SR were not mediated by an FcR mechanism. Direct competition between rSR and human IgG in binding to anti-IgG or anti-SR antibodies confirm that S. mutans SR protein possesses Ag mimicry with human IgG. Our studies provide some evidence that S. mutans SR protein and human IgG H chains share autoimmune epitopes which could play a role in the induction of anti-IgG antibodies and therefore could explain the enhancement of anti-IgG antibody levels observed in rabbits immunized with either S. mutans whole cells or purified B-related Ag.

Animals↗

PubMed1987

Local response in rat to liposome-associated Streptococcus mutans polysaccharide-protein conjugate.

The effect of gastric intubation with soluble or liposome-associated Streptococcus mutans serovar polysaccharide, 74-kDa saliva receptor (74K SR protein) or polysaccharide-74K SR protein conjugate on the locally induced salivary IgA response and memory in rats was investigated. Animals immunized on four successive days with soluble antigens showed a weak salivary anti-74K SR protein or anti-polysaccharide IgA response. Rats primed and boosted by a single injection of liposome-associated 74K SR protein or polysaccharide-74K SR protein conjugate developed a salivary anti-74K SR protein IgA and IgG primary and secondary response. A primary anti-polysaccharide response was only observed in saliva of animals immunized with either high concentration of liposome-associated polysaccharide or liposome-associated polysaccharide-74K SR protein conjugate. However, a secondary local anti-polysaccharide IgA response was detected in animals boosted with liposome-polysaccharide-74K SR protein conjugate. No such anamnestic response was seen when high dose of liposome-associated polysaccharide was used to boost the animals. Furthermore, the salivary anti-polysaccharide IgA response paralleled the anti-74K SR protein IgA response. These studies showed that intragastric immunization of rats with liposome-associated polysaccharide-74K SR protein conjugate produced a local anti-polysaccharide IgA memory.

Animals↗

PubMed1986

Serum and salivary antibody responses in rats orally immunized with Streptococcus mutans carbohydrate protein conjugate associated with liposomes.

In this study we describe the preparation of a Streptococcus mutans vaccine consisting of a purified polysaccharide antigen, derived from S. mutans OMZ175 serotype f, covalently coupled through reductive amination to a previously isolated 74,000-molecular-weight (74K) cell wall protein which interacts with saliva proteins (74K-SR). We also investigated the local and systemic immune response to the poly-74K-SR conjugate after oral administration of the conjugate associated with liposomes. Intragastric administration of liposome-associated poly-74K-SR conjugate in rats produced a local immunoglobulin A (IgA) response directed against the polysaccharide and the cell surface protein, whereas liposome-associated polysaccharide was unable to induce any detectable local IgA response. The antigenicity of the polysaccharide in the conjugate was not affected by the coupling reaction, while that of the cell surface protein was reduced. We showed that the immunogenicity of S. mutans polysaccharide could be improved by chemical coupling with a carrier cell surface protein. If such a conjugate were orally administered with liposomes it could constitute a potential vaccine against dental caries.

Administration, Oral↗

PubMed1985

Local and systemic immune response to orally administered liposome-associated soluble S. mutans cell wall antigens.

The aim of the present study was to develop an immunization procedure which preferentially stimulated the IgA system of rats, with release of IgA in secretions. Rats immunized by intragastric route with liposome-associated soluble antigen extracted from Streptococcus mutans cell wall, showed a significantly higher IgA (and IgG) response than did rats injected with the soluble antigen alone. In saliva, maximal antibody titres were obtained 11 days after the beginning of intubations for IgA, and 16 days for IgG. After a booster immunization, the secondary response occurred very quickly in saliva and, like the primary response, it was almost exclusively of the IgA class. This demonstrates, on one hand the existence of immunological memory in the IgA system and, on the other, the efficiency of liposomes as insoluble adjuvants in eliciting an immunological response.

Administration, Oral↗