Mutans streptococcal infection induces salivary antibody to virulence proteins and associated functional domains

Autor(es)

Nogueira, R. D. ^[1] ; King, W. F. ; Gunda, G. ^[2] ; Culshaw, S. ; Taubman, M. A. ; Mattos-Graner, R. O. ^[1] ; Smith, D. J. ^[3]

Afiliação do(s) autor(es)

^[1] Univ Piracicaba, UNICAMP, Piracicaba Dent Sch, Piracicaba, SP - Brazil

^[2] Harvard Univ, Sch Dent Med, Boston, MA 02115 - USA

^[3] Forsyth Inst, Dept Immunol, Boston, MA 02115 - USA

• Tipo de documento: Artigo Científico
• Fonte: Infection and Immunity; v. 76, n. 8, p. 3606-3613, AUG 2008.
• Citações Web of Science: 7

Resumo

The interplay between mucosal immune responses to natural exposure to mutans streptococci and the incorporation and accumulation of these cariogenic microorganisms in oral biotilms is unclear. Am initial approach to explore this question would be to assess the native secretory immunity emerging as a consequence of Streptococcus mutans infection. To this end, we analyzed salivary immunoglobulin A (IgA) antibody to mutans streptococcal glucosyltransferase (Gtf) and glucan binding protein B (GbpB) and to domains associated with enzyme function and major histocompatibility complex (MHC) class 11 binding in two experiments. Salivas were collected from approximately 45-day-old Sprague-Dawley rats, which were then infected with S. mutans SJ32. Infection was verified and allowed to continue for 2 to 2.5 months. Salivas were again collected following the infection period. Pre- and postinfection salivas were then analyzed for IgA antibody activity using peptide- or protein-coated microsphere Luminex technology. S. mutans infection induced significant levels of salivary IgA antibody to Gtf (P < 0.002) and GbpB (P < 0.001) in both experiments, although the levels were usually far lower than the levels achieved when mucosal immunization is used. Significantly (P < 0.035 to P < 0.001) elevated levels of postinfection salivary IgA antibody to 6/10 Gtf peptides associated with either enzyme function or MHC binding were detected. The postinfection levels of antibody to two GbpB peptides in the N-terminal region of the six GbpB peptides assayed were also elevated (P < 0.031 and P < 0.001). Interestingly, the patterns of the rodent response to GbpB peptides were similar to the patterns seen in salivas from young children during their initial exposure to S. mutans. Thus, the presence of a detectable postinfection salivary IgA response to mutans streptococcal virulence-associated components, coupled with the correspondence between rat and human mucosal immune responsiveness to naturally presented Gtf and GbpB epitopes, suggests that the rat may be a useful model for defining mucosal responses that could be expected in humans. Under controlled infection conditions, such a model could prove to be helpful for unraveling relationships between the host response and oral biofilm development. (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