Objective: This study was aimed at using the gene vaccines pcDNA3-pac and pcDNA3-gtfB which were constructed on PAc and GTF-B gene vaccinating gnotobiotic rats by submandibular gland-target injection to observe the level of salivary S. mutans and dental plaque inhabitation.
Methods: Thirty-six 28-day-old Wistar rats were divided into 6 groups, including those vaccinated with pcDNA3-pac, pcDNA3-gtfB, pcDNA3-pac combined with pcDNA3-gtfB, inactive whole cell of S. mutans JBP, and those injected with pcDNA3 and 0.1 mol/L PBS buffer respectively. Each rat was administrated with 100 micrograms vaccines or controlled materials by submandibular gland-target injection, vaccinated three times at 1-2 weeks interval. Then the gnotobiotic rat model was constructed, following that all rats were fed with cariogenic diet 2000# for 3 months. Rat saliva was collected to assay the level of S. mutans in saliva and evaluate the dental plaque index.
Results: The level of S. mutans in saliva and the dental plaque index of the group vaccinated with pcDNA3-pac combined with pcDNA3-gtfB and the group with inactive S. mutans cell were lower than those of other groups. And they were the highest in the groups injected with pcDNA3 or PBS buffer (P < 0.01 or P < 0.05). No statistically significant differences were observed between the group vaccinated with pcDNA3-pac and the group vaccinated with pcDNA3-gtfB, between the group vaccinated with pcDNA3-pac combined with pcDNA3-gtfB and the group for positive control, and between the pcDNA3 group and PBS buffer group (P > 0.05).
Conclusion: The two gene anticaries vaccines induce the specific antibodies and thus produce effects on the level of S. mutans in saliva and dental plaque index. Therefore gene vaccines pcDNA3-pac and pcDNA3-gtfB are effective, and joint gene vaccines inoculation is optimal.