Effect of oral administration of glucosyltransferase antigens on experimental dental caries

Abstract

The effect of oral administration of soluble antigen preparations containing glucosyltransferase on dental caries in hamsters was studied. Immunization was accomplished by feeding glucosyltransferase for 21 to 27 consecutive days. This immunization regimen resulted in the formation of salivary antibody, which was detected by functional inhibition of enzymatic activity and by a modified enzymelinked immunosorbent assay. A serum response also occurred in two of the three experiments performed. After infection with cariogenic Streptococcus mutans strain 6715, glucosyltransferase-fed hamsters had significantly fewer S. mutans cells recoverable from molar surfaces on six of nine occasions, compared with buffer-fed control groups. Hamsters orally immunized with glucosyltransferase also always had lower mean caries scores and mean numbers of lesions than comparably infected sham-immunized groups. The results of this study suggest that significant protection from experimental dental caries can be accomplished by oral administration of soluble antigen preparations containing glucosyltransferase.

Immune properties of glucosyltransferases from S. sobrinus

“…Antibody to the GTF-S did not inhibit giucan synthesis by purified GTF-I and did not react with GTF-I in Western blot analyses. Of 2 antisera to GTF-I only one (12) showed modest inhibition of purified GTF-S (35-39%). Antibody to GTF-I completely inhibited water-insoluble polyglucan synthesis in the presence or absence of primer.…”

“…Total glucan synthesized (Tables 2, 3) was measured as previously described (12), Briefly, 5 \i\ of serum is pre-ineubated for 1 h with 7 ng of GTF-I or GTF-S in 0,1 ml of phosphate buffer with azide (0,02 M sodium phosphate, 0,02% sodium azide; PBA) pH 6,8, To this mixture 0,2 ml buffer is added eontaining 1 mg of primer dextran TIO (Pharmacia Fine Chemicals) and 10 na-noeuries (11 ng) of (glucose'''C(U))-sucrose. The incubation is allowed to proeeed for 6 hours before the reaction is stopped with 2 volumes of 95% ethanol.…”

“…In our early investigations of the effects of polyelonal antibodies on GTF, we suggested that the enzymes eould be structurally, as well as functionally, different (9), It has been demonstrated that GTF are also important antigens in eliciting protective antibody to interfere with dental caries (10)(11)(12), Early studies indicated that both GTF-I and GTF-S might give rise to protective antibody (11), Further investigations utilized combinations of GTF enzyme activities; therefore the relative protec-tive efficacy of GTF could not be determined from these studies. We were interested in examining the effects of specific antibody on purified enzymes in order to determine the GTF with the most protective potential.…”

Properties of practical oral liposome‐Streptococcus mutans glucosyltransferase vaccines for effective induction of caries protection

“…Streptococcus mutans is the principal etiologic agent of human dental caries (18), and numerous studies in experimental animals have evaluated the nature of the antigen(s) and the mode of immunization most effective in inducing protective immune responses against S. mutans-induced dental caries (20,25). Oral vaccines consisting of purified S. mutans glucosyltransferase (GTF) have been shown to induce significant salivary IgA responses and caries protection in hamsters (34,35). Furthermore, when GTF was incorporated into liposomes and given to gnotobiotic rats by gastric intubation, higher IgA responses and reductions of carious lesions on mandibular molars were observed than in rats given free GTF (27).…”

Effects of antibodies to glucosyltransferase on soluble and insolubilized enzymes

“…These include formal vaccination protocols involving live mutans streptococci (Bowen, 1969) or extracellular molecules (eg, glucosyltransferases, antigen I/II, glucan binding protein) of these same oral bacteria (Schöller et al, 1978;Smith and Taubman, 1996;Yu et al, 1997) as well as passive immunization techniques, where previously produced antibody is applied topically as a means to control the growth of cariogenic species (Hatta et al, 1997;Ma et al, 1998). The Gtfs of S. mutans have long been target molecules to develop an effective vaccine to D Wunder and WH Bowen 290 Oral Diseases aid in the prevention of caries (Carlsson and Krasse, 1968;Bowen et al, 1976;Smith et al, 1979). To date, however, no effective, long-term immunotherapy based on Gtf immunity has been developed (Bowen, 1996).…”