Analysis of the molecular mechanisms of targeted anti-caries DNA plasmid enhancing antibody responses by gene arrays.
BACKGROUND
The cytotoxic T lymphocyte antigen 4 (CTLA4) represents an attractive ligand for use in the targeting of antigens to dendritic cells (DCs). Studies have shown that CTLA4 targeted DNA vaccines induced accelerated and increased antibody responses compared to nontargeted vaccines. However, little is known about the molecular events on DCs after transfection with targeted DNA vaccines.


METHODS
Here we constructed a green fluorescent protein (GFP)-labeled targeted anti-caries plasmid pMGJGLU/GFP and a GFP-labeled nontargeted anti-caries plasmid pCDGLU/GFP, compared the antibody responses they induced in mice, and investigated the gene expression profiles of DCs transfected with pMGJGLU/GFP and pCDGLU/GFP by gene array analysis.


RESULTS
The data obtained showed that pMGJGLU/GFP induced accelerated and increased serum antibody responses in mice compared to pCDGLU/GFP. Overall, the expression levels of 28 genes were up-regulated in pMGJGLU/GFP transfected DCs compared to pCDGLU/GFP transfected DCs by gene array analysis. Real-time reverse transcriptase-polymerase chain reaction analysis on pMGJGLU/GFP transfected DCs and pCDGLU/GFP transfected DCs confirmed the up-regulation of the mRNA expression levels of seven selected genes. Notably, we identified the specific up-regulation of mRNA expression levels of cytokines Ccl17, Ccl19, and antigen presentation receptor Cd209a of pMGJGLU/GFP transfected DCs, suggesting a more rapid migration of DCs to lymph nodes and a T helper 2 biased immune response.


CONCLUSIONS
In the present study, we confirmed our previous reports that CTLA4 targeted DNA vaccines could induce increased antibody responses compared to nontargeted vaccines. Ccl17, Ccl19 and Cd209a may play an important role in the enhanced immune responses.
Xu
Qing-An
QA
Key Laboratory for Oral Biomedical Engineering of Ministry of Education, School and Hospital of Stomatology, Wuhan University, Hubei, China.
Yu
Fei
F
Fan
Mingwen
M
Xing
Quan
Q
Liu
Gaoxia
G
Liu
Chang
C
D000818:Animals; D000917:Antibody Formation / Q000187:drug effects*; D015703:Antigens, CD; D060908:CTLA-4 Antigen; D003713:Dendritic Cells / Q000378:metabolism*; D016503:Drug Delivery Systems / Q000379:methods; D020869:Gene Expression Profiling; D015316:Genetic Therapy / Q000379:methods*; D049452:Green Fluorescent Proteins / Q000008:administration & dosage / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D010957:Plasmids; D012333:RNA, Messenger / Q000032:analysis; D015854:Up-Regulation / Q000235:genetics; D019444:Vaccines, DNA / Q000008:administration & dosage*
D015703:Antigens, CD; D060908:CTLA-4 Antigen; C556707:Ctla4 protein, mouse; D012333:RNA, Messenger; D019444:Vaccines, DNA; D049452:Green Fluorescent Proteins