[Infiltration of DCs and CD4+ T cells in muscle after DNA immunization].
OBJECTIVE
In order to get a better understanding of the mechanism of DNA initiating specific cytotoxicity T lymphocyte (CTL) immune response, we observed the local infiltration in injection site at different time after DNA immunization and further studied the characters of infiltration cells.


METHODS
The local infiltration in injection sites was observed by HE staining at 6 h, 12 h and 1-6 days after DNA immunization. Infiltration cells were further studied with the mice dendritic cells marker CD205, T lymphocyte marker CD4 and CD8 by immunohistological methods.


RESULTS
phAFP injection into mouse muscle led to a local infiltration. Infiltrates reached peak at 3-6 days after injection and appeared in several discrete clusters within the muscles. The predominant cell types found in infiltrates were macrophage-like cells and lymphocytes. Immunohistological staining revealed CD205+ and CD4+ cells. CD4+ cells could be detected in any of the injected muscles. CD205+ cells were only seen at 24 h to day 3, appearing later and disappearing earlier than CD4+ cells. However, CD8+ immunostaining positivity could not be found.


CONCLUSIONS
Our findings indicate that the character of local infiltration after DNA immunization is different from the inflammation of injection. The recruitment of CD205+ to the injection site suggests that DCs and Th cells play an important role in DNA immunization.
Deng
Xiao-ling
XL
Department of Immunology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu 610041, China.
Wang
Xia
X
Wei
Da-peng
DP
Zhang
Ping
P
Cai
Mei-ying
MY
Bi
Jian-hong
JH
Hu
Li-luan
LL
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D003713:Dendritic Cells / Q000276:immunology*; D007273:Injections, Intramuscular; D051379:Mice; D008807:Mice, Inbred BALB C; D018482:Muscle, Skeletal / Q000276:immunology; D014611:Vaccination; D019444:Vaccines, DNA / Q000276:immunology*
D019444:Vaccines, DNA