title: Anti-caries DNA vaccine-induced secretory immunoglobulin A antibodies inhibit formation of Streptococcus mutans biofilms in vitro.
abstract: OBJECTIVE
  To investigate the effects of anti-caries DNA vaccine-induced salivary secretory immunoglobulin A (S-IgA) antibodies on Streptococcus mutans (S. mutans) adherence and biofilms formation in vitro.
  
  
  METHODS
  Adult female Wistar rats were intranasally immunized with the anti-caries DNA vaccine pGJA-P/VAX. Their saliva samples were collected at different times after the immunization, and S-IgA antibody level in the saliva and its inhibition on S. mutans adherence were examined. The effects of S-IgA in the saliva with the strongest inhibitory effects were examined at 3 different stages, ie acquired pellicles, biofilm formation and production of mature biofilms. The number of viable bacteria and depth of the biofilm at 16 h in each stage were determined using counting colony forming units and using a confocal laser scanning microscopy (CLSM). The participation of S-IgA in acquired pellicles and its aggregation with S. mutans were also observed under CLSM.
  
  
  RESULTS
  The S-IgA titer in saliva reached its peak and exhibited the strongest inhibition on S. mutans adhesion at 10 weeks after the immunization. The colonies and depth of the biofilm in the saliva-pretreated group were 41.79% and 41.02%, respectively, less than the control group. The colonies and depth of the biofilm in the co-culture group were 27.4% and 22.81% less than the control group. The assembly of S. mutans and S-IgA was observed under CLSM after co-cultivation. In the mature-stage biofilm, no differences were observed between the different groups.
  
  
  CONCLUSIONS
  These results demonstrate that the anti-caries DNA vaccine induces the production of specific S-IgA antibodies that may prevent dental caries by inhibiting the initial adherence of S. mutans onto tooth surfaces, thereby reducing the accumulation of S. mutans on the acquired pellicles.
authors.affiliation: Key Laboratory for Oral Biomedical Engineering of Ministry of Education, School & Hospital of Stomatology, Wuhan University, China.
authors.forename: Li
authors.initials: L
authors.lastname: Huang
authors.forename: Qing-an
authors.initials: QA
authors.lastname: Xu
authors.forename: Chang
authors.initials: C
authors.lastname: Liu
authors.forename: Ming-wen
authors.initials: MW
authors.lastname: Fan
authors.forename: Yu-hong
authors.initials: YH
authors.lastname: Li
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D018441:Biofilms / Q000254:growth & development*; D003731:Dental Caries / Q000276:immunology / Q000517:prevention & control*; D005260:Female; D007071:Immunoglobulin A, Secretory / Q000032:analysis / Q000276:immunology*; D051381:Rats; D017208:Rats, Wistar; D012463:Saliva / Q000276:immunology; D013295:Streptococcus mutans / Q000502:physiology*; D019444:Vaccines, DNA / Q000276:immunology / Q000627:therapeutic use*
chemical_list: D007071:Immunoglobulin A, Secretory; D019444:Vaccines, DNA; C530535:pGJA-P VAX vaccine