Immunorecognition ofStreptococcus mutanssecreted proteins protects against caries by limiting tooth adhesion

Abstract Childhood caries, a chronic disease affecting 60–90% of children in industrialized countries, results in lesions in primary and permanent dentition, leading to hospitalizations, emergency room visits, high treatment costs, and loss of school days. It diminishes the child’s ability to learn and increases the risk of caries in adulthood. Despite multiple risk factors for caries, significant interpersonal variability unaccounted for by these factors exists. The immune system generates a personal antibody repertoire that helps maintain a balanced and healthy oral microbiome. Streptococcus mutans is a key bacterium in caries development. Utilizing mass-spectrometry, we examined which S. mutans proteins are identified by antibodies of children with and without caries and identified a core set of proteins recognizable by the immune system of most individuals. This set was enriched with proteins enabling bacterial adhesion. To study the physiological relevance of these findings, we tested the ability of saliva to prevent S. mutans adherence to tooth surfaces. Saliva from caries-free individuals, but not children with caries, was found to hinder the binding of S. mutans to teeth. These findings delineate the S. mutans proteome targeted by the immune system and suggest that the inhibition of bacterial adherence to teeth is a primary mechanism employed by the immune system to maintain oral balance and prevent caries formation. These discoveries offer fresh insights into the immune system’s role in preserving oral health and preventing caries development. Targeting S. mutans proteins implicated in bacterial adhesion could be a promising strategy for preventing childhood caries.