Enhancement of immune responses to hepatitis B vaccine in immunodepressed mice by CpG oligodeoxynucleotide.
OBJECTIVE
To investigate enhancement of immune response to hepatitis B vaccine in immunosuppressed mice by CpG oligodeoxynucleotide (ODN).


METHODS
Immunodepressed C57BL/6 mice caused by cytoxan were given an injection of either hepatitis B vaccine alone or hepatitis B vaccine and CpG ODN into the left tibialis anterior muscle, then the mice were given another shot after 2 weeks using the same formulation. Blood was collected at 5 weeks after immunization and anti-hepatitis B surface antigen IgG and IL-12 levels were measured by ELISA. Spleens of immunized mice were observed under microscope.


RESULTS
There was a two-fold increase in anti-hepatitis B surface antigen IgG level when hepatitis B vaccine was mixed with CpG ODN to immunize immunodepressed mice. There was a significant increase in IL-12 level when hepatitis B vaccine was mixed with CpG ODN. Under optical microscope, there were fewer lymphocytes in immunodepressed mice than in normal control group. The proliferation level of spleen lymphocytes in CpG ODN group was elevated compared with that of normal control group and nuclei of lymphocytes became larger.


CONCLUSIONS
CpG ODN can enhance the immune response to hepatitis B vaccine in immunodepressed mice.
Qin
Wei-bing
WB
Family Planning Research Institute of Guangdong, Guangzhou 510600,China. guardqin@163.com
Jiang
Jian-wei
JW
Yang
Ning
N
Chen
Qiao-er
QE
Wang
Yi-feng
YF
Wei
Xiang-cai
XC
Ou
Ru-qiang
RQ
D000276:Adjuvants, Immunologic; D000818:Animals; D049109:Cell Proliferation; D006514:Hepatitis B Surface Antigens / Q000276:immunology; D017325:Hepatitis B Vaccines / Q000276:immunology*; D016867:Immunocompromised Host; D007074:Immunoglobulin G / Q000097:blood*; D018664:Interleukin-12 / Q000096:biosynthesis; D051379:Mice; D008810:Mice, Inbred C57BL; D009838:Oligodeoxyribonucleotides / Q000276:immunology*; D013154:Spleen / Q000166:cytology
D000276:Adjuvants, Immunologic; C408982:CPG-oligonucleotide; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines; D007074:Immunoglobulin G; D009838:Oligodeoxyribonucleotides; D018664:Interleukin-12