Novas abordagens vacinais contra <i>Streptococcus mutans</i>.

Abstract

Streptococcus mutans is considered the major etiological agent of human dental caries, a chronic and infectious disease. The disease has a broad incidence and is considered an important worldwide public health problem. The initial adhesion of S. mutans to the tooth surface depends on the interaction of the surface-exposed P1 protein and the salivary agglutinin adsorbed to the tooth. Therefore, the P1 protein and fragments derived from it are considered important targets in vaccine strategies to prevent dental caries. The present work aimed to develop and characterize new mucosal vaccine strategies against S. mutans, using as antigen model the protein P1 39-512 , a N-terminal fragment derived from the P1 protein. For this purpose, we used non-recombinant Bacillus subtilis spores and a non-toxic mutant of the enterotoxigenic Escherichia coli (ETEC) heat-labile toxin (LTK63) as vaccine adjuvants. The P1 39-512 protein was obtained using a recombinant B. subtilis strain. Vaccine formulations were based on the co-administration of the P1 39-512 protein with spores and/or LTK63 via sublingual route. The results demonstrated that both adjuvants showed immunomodulatory properties on antibody responses. However, the LTK63 adjuvant was capable to induce the highest antigen-specific antibody titers and elicited mucosal responses with the induction of secretory IgA (S-IgA) antibodies in saliva samples. In addition, the formulation using this adjuvant induced enhanced responses mediated by effector antibodies capable to recognize the native P1 protein expressed on the surface of S. mutans strains. The combination of both adjuvants did not increase the magnitude of systemic antibody and S-IgA responses when compared to the administration of P1 39-512 + LTK63. In conclusion, the results open perspectives for the development of vaccination strategies for the control of dental caries based on the co-administration of S. mutans antigens and LTK63.