Secretory immunity in defense against cariogenic mutans streptococci

Specific immune defense against cariogenic mutans streptococci is provided largely by salivary secretory IgA antibodies, which are generated by the co mmon mucosal immune system. This system is functional in newborn infants, w ho develop salivary IgA antibodies as they become colonized by oral microor ganisms. The mechanisms of action of salivary IgA antibodies include interf erence with sucrose-independent and sucrose-dependent attachment of mutans streptococci to tooth surfaces, as well as possible inhibition of metabolic activities. The goal of protecting infants against colonization by mutans streptococci might be accomplished by applying new strategies of mucosal im munization that would induce salivary IgA antibodies without the complicati ons of parenteral immunization. Strategies of mucosal immunization against mutans streptococci currently under development include the use of surface adhesins and glucosyltransferase as key antigens, which are being incorpora ted into novel mucosal vaccine delivery systems and adjuvants. The oral app lication of preformed, genetically engineered antibodies to mutans streptoc occal antigens also offers new prospects for passive immunization against d ental caries.