[Intranasal immunization against dental caries with plasmid DNA encoding pac gene of Streptococcus mutans in gnotobiotic rats].
OBJECTIVE
To assess the efficacy of plasmid DNA encoding pac gene of Streptococcus mutans (S. mutans) intranasally immunized in gnotobiotic rats and to compare the effect of two different delivery systems.


METHODS
Sprague Dawley rats, infected with S. mutans at 20 days of age, were intranasally immunized with plasmid pCIA-P (group A), Dosper-DNA complex (group B), Bupivacaine-DNA complex (group C). Control rats were either immunized with plasmid pCI (group D), distilled water (group E) or immunized intramuscularly (group F). All the rats were boosted 2 weeks later. ELISA determined the antibodies against the vaccines. Keyes caries score was used to evaluate the anti- caries effectiveness of the vaccines at the terminal study.


RESULTS
As for the antibody reactions, there were significantly (P < 0.01) differences between rats immunized with DNA vaccine and non-immunized rats. And rats in group B and C had the significantly (P < 0.01) higher level of specific salivary anti-PAc IgA antibodies and rats (group B, C, F) had the significantly (P < 0.01) higher specific serum anti-PAc IgG responses to DNA vaccine. Keyes scores of rats (group B and C) were significantly (P < 0.01) lower than others.


CONCLUSIONS
Intranasal immunization with plasmid pCIA-P encoding pac gene successfully reduces the caries and appears to be a promising approach against dental caries. Cationic liposome Dosper and local anesthetic bupivacaine could enhance the efficacy of DNA vaccine.
Guo
Jihua
J
Department of Operative and Endodontics, School of Stomatology, Wuhan University, Wuhan 430079, China.
Fan
Mingwen
M
Bian
Zhuan
Z
Jia
Rong
R
Peng
Bin
B
D000281:Administration, Intranasal; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001426:Bacterial Proteins / Q000235:genetics*; D003731:Dental Caries / Q000517:prevention & control*; D005260:Female; D007114:Immunization; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D008562:Membrane Glycoproteins; D010957:Plasmids / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D022541:Streptococcal Vaccines / Q000235:genetics / Q000276:immunology / Q000627:therapeutic use; D013295:Streptococcus mutans / Q000235:genetics / Q000276:immunology*; D016896:Treatment Outcome; D019444:Vaccines, DNA / Q000235:genetics / Q000276:immunology / Q000627:therapeutic use*
D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D008562:Membrane Glycoproteins; C055764:S-layer proteins; D022541:Streptococcal Vaccines; D019444:Vaccines, DNA