Environmental origin of natural antibodies to teichoic acid

Interaction of anti-kojibiose antibody with the lipoteichoic acids from Streptococcus faecalis and Streptococcus faecium

Antisera prepared in rabbits by immunization with p-aminophenyl beta-kojibioside conjugated to bovine serum albumin (antikojibiose sera), readily agglutinated whole cells of Streptococcus faecalis or Streptococcus faecium, and showed specific reactions with the lipoteichoic acids (LTAs) of these streptococci by passive hemagglutination, microscale enzyme-linked immunosorbent assay, and crossed immunoelectrophoresis. The interaction of the antikojibiose sera with the LTAs was inhibited best by kojibiose [alpha-D-glucopyranosyl-(1----2)-D-glucose], somewhat less by the dextran from which the kojibiose was prepared, and not measurably by maltose [alpha-D-glucopyranosyl-(1----4)-D-glucose]. The sera reacted only minimally in only the most sensitive assay (microscale enzyme-linked immunosorbent assay) with LTA from group A streptococci (this LTA contains a single kojibiosyl residue as part of the glycolipid moiety of the molecule and failed to react with the Lactobacillus fermentum LTA which is substituted with alpha-D-galactopyranosyl-(1----2)-D -glucosyl units.

Specificity of natural antibodies reactive with Streptococcus mutans in monkeys

Enzyme-linked immunosorbent assays were used to measure levels of natural antibody to defined antigens of Streptococcus mutans in sera from monkeys (Macaca fascicularis). The results suggest that most of the antibody in young monkeys that binds to whole bacteria is not specific to S. mutans.

Suppression of the primary IgM response by environmental teichoic acid

It has been shown previously that ingestion of glycerol teichoic acid (GTA) in the conventional laboratory diet (8 mg/kg) is the stimulus for natural background responses to GTA in rats. Since injected GTA suppresses responses to sheep red blood cells (SRBC), it was suspected that dietary GTA also might be acting suppressively. A comparison of rats fed the conventional diet with rats fed a GTA-free diet showed that ingested GTA markedly suppressed immune and background direct plaque-forming cell (PFC) responses to SRBC. It appeared that a direct causal relationship existed between the degree of suppression and the amount of GTA exposure. When GTA-deprived rats were force-fed varying doses of GTA or when conventional animals were injected (i.p.) with GTA, increasing the total GTA dose resulted in decreased direct PFC responses to SRBC. Suppression was also observed when GTA-deprived rats were force-fed GTA-containing Bacillus sp. ATCC 29726. The phenomenon of suppression by dietary GTA was not restricted to responses to SRBC, as similar results were obtained with chicken erythrocytes. When IgG PFC were measured, no difference between conventional and GTA-deprived groups was observed. Thus, an IgM-IgG shift does not seem to play a role in the mechanism of suppression by GTA.

Naturally-occurring IgA antibodies to glycerol-teichoic acid in human saliva. Correlation with caries activity

Human subjects were examined for caries activity and for naturally-occurring salivary IgA of glycerol-teichoic acid (TA) specificity by an enzyme-linked immunosorbent assay. Subjects free of active caries produced higher levels of anti-TA in their saliva than persons with one or more active carious lesions.

Modulation of murine lymphocyte mitogen responses by glycerol-teichoic acid

Glycerol-teichoic acid (GTA) showed a modulatory effect on the in vitro response of murine splenocytes to the mitogens concanavalin A (Con A) and lipopolysaccharide (LPS) as measured by incorporation of 3H-thymidine. GTA inhibited the response to Con A when added prior to addition of the mitogen, while addition 24 hr after had no significant effect on the response. The degree of suppression was dose dependent in a range from 0.1-5 microgram GTA/culture. The spleen cell response to LPS was enhanced by GTA when added prior to the mitogen. Peak enhancement occurred at 1-2 microgram GTA/culture, depending on the time of addition. GTA added 24 hr after LPS produced no significant effect on mitogenesis. Addition of GTA alone to spleen cell cultures produced a slight suppression of DNA synthesis and was toxic at 10 microgram/culture if incubated at least 66 hr. GTA is bound to murine spleen cells as indicated by decreased passive hemagglutination inhibition activity of culture supernates.

Immunosuppression of anti-sheep erythrocyte responses by glycerol teichoic acid immune complexes

Sprague-Dawley rats which produce "naturally occurring" antibodies to glycerol teichoic acid (GTA) displayed immunosuppression of anti-sheep erythrocyte plaque-forming cell and serum antibody responses when a single dose of lipid-free GTA was administered 24 h before immunization. Such suppression was enhanced by administering GTA complexed with anti-GTA immunoglobulin G. Animals fed a GTA-free diet produced no anti-GTA immunoglobulins and failed to show GTA-mediated immunosuppression under similar experimental conditions. However, when those animals were given GTA-anti-GTA complexes, suppression was evident. The results suggested antigenic competition mediated by immune complex-activated suppressor T cells. Lipid-free GTA did not stimulate serum antibody responses under the experimental conditions employed.

Immunogenicity of soluble versus cellular glycerol teichoic acid

Guinea pigs which were injected with either whole bacilli or purified soluble glycerol teichoic acid (GTA) usually exhibited a rise in hemolysin titer to GTA-coated erythrocytes. The only exceptions were those animals having high baseline titers of natural anti-GTA antibodies. Rats yielded better responses than guinea pigs and produced significantly higher responses to the soluble antigen than to the cellular GTA. Rats reared on a GTA-free diet were predominantly free of natural antibodies to GTA and furnished a more clear-cut model for assaying immune responses. Using this model, it was shown that adsorption of GTA to homologous erythrocytes before injection resulted in poor responses, suggesting that such spontaneous adsorption does not account for the good responses to soluble antigen. In GTA-deprived rats, positive skin tests were induced only with bacilli, whereas migration inhibitory factor was induced with both bacilli and soluble antigen. Hemolytic plaques in immunized rats were increased over controls with both kinds of immunogen, but the GTA-deprived rats responded better than conventional ones, and hemolytic plaque responses to bacilli were better than those to soluble antigen. This reversal of the serum hemolysin results may be due to delayed suppression by soluble GTA or to antibody cycling. The guinea pig data, combined with results from GTA-deprived rats, suggest that high antibody levels resulted in depressed antibody synthesis, perhaps because antibody cycling was initiated. No evidence was found to explain the superior responses to soluble antigen, but it did not seem related to formation of immune complexes or adsorption to erythrocyte membranes.

Inflammatory lesions and bone resorption induced in the rat periodontium by lipoteichoic acid of Streptococcus mutans

Severe inflammatory lesions were induced in the periodontal tissues of the rat following the intragingival injection of lipoteichoic acid (LTA) from Streptococcus mutans. There was no difference in the severity and distribution of the lesions between nonimmunized rats and animals immunized against LTA after antigenic challenge. The lesions are characterized by the occurrence of granulation tissue, massive infiltration of PMNs, abscess formation, bone resorption, and new bone formation. Deacylated LTA and saline caused relatively mild inflammation, and no significant bone resorption or new bone formation was evident. The peak response was reached after 3 intragingival infections. The mechanisms by which LTA caused the pathological alterations in the rat periodontium and the possible relations of this experimental model to periodontal disease in the human are discussed.

Cyclic appearance of antibody-producing cells in the peripheral blood in response to a chemically-defiend polyglycerophosphate antigen

Cyclic production of serum antibody and of plaque-forming cells (PFC) of polyglycerophosphate (PGP) specificity was observed in the peripheral blood of rabbits following a single injection of antigen. Individual animals were examined at 4-day intervals up to 28 days post-injection. Direct and indirect PFC displayed initial peaks at 4 days post-injection with an 8-day lag between the first and second peaks and a 12-day lag between the second and third peaks. Serum IgM rose to a peak 4 days after the initial PFC peak and gradually dropped to baseline levels. Serum IgG rose sharply to a peak at 4 days following the initial PFC peak and generally remained at elevated levels for the duration of the experiment. Cycling of background sheep erythrocyte PFC was also observed, but cycles were out of phase with the PGP cycles and with each other.