Characterization of Salivary Immunoglobulin A Responses in Children Heavily Exposed to the Oral Bacterium Streptococcus mutans : Influence of Specific Antigen Recognition in Infection

Abstract

The initial infection of children by Streptococcus mutans, the main pathogen of dental caries, depends on the ability of S. mutans to adhere and accumulate on tooth surfaces. These processes involve the adhesin antigen I/II (AgI/II), glucosyltransferases (GTF) and glucan-binding protein B (GbpB), each a target for anticaries vaccines. The salivary immunoglobulin A (IgA) antibody responses to S. mutans antigens (Ags) were characterized in 21 pairs of 5-to 13-month-old children. Pairs were constructed with one early S. mutans-infected and one noninfected child matched by age, racial background, number of teeth, and salivary levels of IgA. Specific salivary IgA antibody response and S. mutans infection levels were then measured during a 1-year follow-up. Robust responses to S. mutans were detected from 6 months of age. Salivary IgA antibody to AgI/II and GTF was commonly detected in salivas of all 42 children. However, GbpB-specific IgA antibody was seldom detected in the subset of infected children (38.1% at baseline). In contrast, most of the subset of noninfected children (76.2%) showed GbpB-reactive IgA antibody during the same period. Frequencies of GbpB responses increased with age, but differences in intensities of GbpB-IgA antibody reactions were sustained between the subsets. At baseline, GbpB-reactive IgA antibody accounted for at least half of the total salivary IgA S. mutans-reactive antibody in 33.3 and 9.5% of noninfected and infected children, respectively. This study provides evidence that a robust natural response to S. mutans Ags can be achieved by 1 year of age and that IgA antibody specificities may be critical in modulating initial S. mutans infection.

Mutans Streptococcal Infection Induces Salivary Antibody to Virulence Proteins and Associated Functional Domains

“…Similar to the pattern seen in young children of salivary IgA antibody specificities following primary exposure to immunogenic levels of S. mutans infection (25,26), responses to both glucosyltransferases and glucan binding protein B were observed in a majority of rats under the infection conditions used in these experiments. Although the IgA antibody levels covered a wide range and were, on average, 10-fold less than those that could be obtained by intranasal immunization with Gtf (Fig.…”

“…Some of the natural higher-affinity responses might also modulate the success or duration of colonization. For example, recent evidence suggests that early formation of salivary IgA antibody to S. mutans glucan binding protein B (GbpB) (2,18) may delay colonization of young children who are being heavily challenged with this cariogenic streptococcus (25,26). The effect of salivary IgA antibody on S. mutans acquisition is compatible with observations indicating that experimental provision of antibody to mutans streptococcal virulence components by either active or passive immunization can provide protective immunity to experimental infection with S. mutans or Streptococcus sobrinus (for reviews, see references 12 and 31).…”

Comparisons of IgA response in saliva and colostrum against oral streptococci species

“…11,20 Patterns of reactivity of salivary IgA antibody against S. mutans (UA159) and S. mitis (ATCC506) antigens were determined in western blot assays as previously described. 20 Sixteen micrograms of antigen extracts were loaded per lane, separated by 6% sodium dodecyl sulfate polyacrylamide gel electrophoresis, and transferred to nitrocellulose membranes.…”

“…SIgA is associated to the oral microbiota control by reducing the adherence of bacteria on the mucosa and teeth. 10 Previous prospective studies with 5-to 24-month-old children heavily exposed to S. mutans showed a complex pattern of salivary IgA reactivity to S. mutans antigens, 11,12 suggesting that responses to virulence-associated antigens, especially against GbpB, may influence the ability of S. mutans to colonize the oral cavity. Thus, the salivary IgA response to GbpB can modulate the infection by S. mutans.…”

Effect of Psychologic Stress on Peroxidase and Thiocyanate Levels in Human Saliva Detected by Ultraweak Chemiluminescence

“…Numerous proteins such as secretory IgA (sIgA), lactoferrin, agglutin, and mucins also participate in the protection of oral tissues. [1][2][3][4] In addition, lysozyme and several peptides such as histatin, defensins, and LL-37 have been determined to have bactericidal activity. 5) Uric acid (UA) is the major component of the total antioxidant system, constituting 70% of to- * To whom correspondence should be addressed: Department of Environmental Biochemistry, University of Shizuoka, School of Pharmaceutical Science, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.…”