-Engineered/Functionalized DNA Vaccine as a Novel Prophylactic Vaccination to Prevent -Induced Periodontitis: An Study.

BACKGROUND

Arg-gingipain A () and Arg-gingipain B () are crucial virulence factors associated with () and have been recognized as promising targets for antibacterial vaccines. Although vaccines containing have shown efficacy, the incorporation of , which lacks the haemagglutinin adhesin () domain, diminishes the vaccine's effectiveness. This study aims to assess the immunogenicity of the functional domain of in mouse periodontitis models.

METHODS

A total of 24 mice were randomly divided into four groups, each receiving different immune injections: group A received phosphate-buffered saline (PBS) as an empty control; group B received pVAX1 as a negative control (NC); group C received pVAX1-; and group D received pVAX1-. The mice were subjected to intramuscular injections every two weeks for a total of three administrations. Prior to each immunization, blood samples were collected for antibody detection under isoflurane anesthesia. Following the final immunization, periodontitis was induced two weeks later by using sutures soaked in a solution. The mice were euthanized after an additional two-week period. To assess the safety of the procedure, major organs were examined through hematoxylin-eosin (HE) staining. Subsequently, the levels of IgG, IgG1, and IgG2a in the serum were quantified via enzyme-linked immunosorbent assay (ELISA). Additionally, the expression of inflammatory factors in the gingiva, including interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor alpha (TNF-α), was determined using quantitative real-time reverse transcript PCR (qRT-PCR). The extent of bone loss in periodontal tissues was evaluated using micro-computed tomography (micro-CT) and HE staining.

RESULTS

HE staining of the organs confirmed the absence of vaccine-induced toxicity . After the second immunization, both the and groups displayed significantly higher specific IgG titers in comparison to the NC and PBS groups ( < 0.05). Furthermore, the and groups exhibited a noteworthy predominance of IgG1 antibodies after three immunization doses, while there was a noticeable reduction in IgG2a levels observed following ligation with sutures, as opposed to the NC and PBS groups ( < 0.05). Additionally, both the and groups showed a significant decrease in the expression of inflammatory factors such as IL-6, IL-1β, and TNF-α, as well as a reduction in bone loss around periodontitis-affected teeth, when compared to the NC and PBS groups ( < 0.05).

CONCLUSIONS

The results of this study demonstrate that the -engineered/functionalized gene vaccine is capable of eliciting a potent prophylactic immune response against -induced periodontitis, effectively serving as an immunogenic and protective agent .