Immunization against dental caries.

Prevention of dental caries has been investigated by immunization with Streptococcus mutans in rodents and subhuman primates. In addition to cells and cell walls of S. mutans, the enzyme glucosyl transferase and purified protein antigens prepared from S. mutans were successfully used in immunization against dental caries. Subcutaneous immunization of rhesus monkeys elicits significant levels of serum IgG, IgM and IgA antibodies, lymphorproliferative response and T cell helper activity to S. mutans cells and to streptococcal antigen (SA) I/II. These immune responses are associated with significant reduction of caries and colonization by S. mutans. However, oral immunization induced only a modest increase in salivary IgA antibodies to S. mutans and a small reduction in caries. Successful immunization in sub-human primates requires optimal T cell helper and minimal suppressor activities in order to elicit high titre and avidity of IgG antibodies. The SA dose required to elicit an optimal T cell helper function in man is HLA-DR dependent. Serum IgG antibodies pass through the gingival crevicular epithelium onto the tooth surface, where they may opsonize S. mutans for phagocytosis by the local neutrophils and prevent adherence of S. mutans, thereby preventing the development of caries.