Characterization of salivary immunoglobulin A responses in children heavily exposed to the oral bacterium Streptococcus mutans: Influence of specific antigen recognition in infection

Autor(es)

Nogueira, Ruchele D. ; Alves, Alessandra C. ; Napimoga, Marcelo H. ; Smith, Daniel J. ; Mattos-Graner, Renata de Oliveira ^[5]

• Tipo de documento: Artigo Científico
• Fonte: Infection and Immunity; v. 73, n. 9, p. 5675-5684, Sept. 2005.
• Área do conhecimento: Ciências Biológicas - Imunologia
• Assunto(s): Cárie dentária Streptococcus mutans

Resumo

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. (AU)

• Processo FAPESP: 02/07156-1 - Análise da resposta imunológica de crianças durante a colonização por Streptococcus mutans e dos fatores genético-moleculares envolvidos na formação do biofilme dental por estes microrganismos
• Beneficiário: Renata de Oliveira Mattos Graner
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores
• Processo FAPESP: 04/07425-8 - Estudo longitudinal dos níveis salivares e especificidade de IgA contra antígenos de Streptococcus mutans em crianças brasileiras na fase inicial de colonização por estes microrganismos
• Beneficiário: Ruchele Dias Nogueira
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto