Objective: To test immune responses after DNA immunization with a plasmid construct encoding an epitope of gingipain RGP-1 from Porphyromonas gingivalis W50.

Methods: Fragments of b-adhesin were cloned into an eucaryotic expression plasmid pcDNA3.1/V5-His-TOPO (Invitrogen) and expressed in COS-7 cells. Expression was confirmed by immunofluorescence and immunoblotting. Sprague-Dawley rats were intramuscularly immunized with cloned b-adhesin and expression was detected with RT-PCR. b-adhesin specific antibodies were detected with ELISA. Rat sera were screened for hemagglutination inhibiting activity.

Results: Expression of b-adhesin was confirmed in the transfected COS-7 cells. b-adhesin immunized animals were expressing the protein in the site of immunization. The immunized animals also showed a specific antibody response against b-adhesin. We were not able to show any increased hemagglutination inhibiting activity in sera from b-adhesin immunized animals.

Conclusion: P. gingivalis b-adhesin can be expressed as a monomer in eucaryotic cells. Immunization with an expression plasmid encoding this protein can induce a specific immune response against b-adhesin. Plasmids encoding epitopes in “critical” antigens like b-adhesin may play an important role in making future DNA vaccines against adult periodontitis.

Back to the Microbiology / Immunology and Infection Control Program
Back to the 81st General Session of the International Association for Dental Research (June 25-28, 2003)

Top Level Search