IADR Abstract Archives

Antibody response against Aggregatibacter actinomycetemcomitans bacteriophage ΦAa among Brazilian individuals

Objective: Aggregatibacter actinomycetemcomitans (Aa) is a Gram-negative bacteria associated with aggressive periodontitis (AP).  Aa strains are frequently lysogenic, and have the capability to invade soft tissue. Since our previous in vitro studies suggested that fibroblast-mediated prophage induction occurs upon co-culture of Aa lysogens with human fibroblasts, a potential exists for phage induction and release in vivo, resulting in the stimulation of an immune response against phage proteins. The purpose of this investigation was to learn whether serum antibodies to bacteriophage-ɸAa virion proteins are found in the sera of Brazilian human populations.

Method: Sera from subjects with aggressive periodontitis (AP), chronic periodontitis (CP) or a healthy periodontium (HP) were collected. Purified bacteriophage ɸAa proteins were separated by SDS-PAGE gels and then transferred to nitrocellulose membranes. Western-blotting reactions were carried out with 1:2,500 dilutions of each subject’s serum as the primary antibody (AB).  Fluorescent signals in a dye from a secondary (antihuman) AB were detected using the Odyssey detection system. Marker proteins or the omission of primary antibody, were used as negative controls.

Result: Antibody response against at least one ɸAa protein was observed in all subjects in the study, with the exception of two from the HP group. AB response to the full complex of ɸAa proteins was observed in 7 of 31 individuals with AP, 2 of 5 with CP and 6 of 16 with HP. Chi-square tests comparing the AP with HP groups indicated that the presence of AB against any ɸAa protein is statistically significant (p= 0.044), but antibody against the whole ɸAa protein complex was not.

Conclusion: AB response against a ɸAa protein or its whole complex was commonly observed in all 3 subject groups. This finding suggests that the in vitro ɸAa induction observed in the laboratory is also occurring in vivo, although it is not necessarily associated with periodontitis.

IADR/LAR General Session
2012 IADR/LAR General Session (Iguaçu Falls, Brazil)
Iguaçu Falls, Brazil
2012
214
Microbiology / Immunology
  • Stevens, Roy  ( Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA )
  • Mattos, Marcello  ( Federal University of Rio de Janeiro, Rio de Janerio, N/A, Brazil )
  • Tinoco, Eduardo  ( State University of Rio de Janeiro, Rio de Janeiro, N/A, Brazil )
  • Buttaro, Bettina  ( Temple University School of Medicine, Philadelphia, PA, USA )
  • Utter, Bryan  ( Temple University School of Medicine, Philadelphia, PA, USA )
  • Fernandes Ferreira, Davis  ( Federal University of Rio de Janeiro-UFRJ, Rio de Janeiro, N/A, Brazil )
    • Oral Session
    Aggregatibacter actinomycetemcomitans
    06/20/2012