Deng Xiao-ling, Wang Xia, Wei Da-peng, Zhang Ping, Cai Mei-ying, Bi Jian-hong, Hu Li-luan
Department of Immunology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu 610041, China.
Sichuan Da Xue Xue Bao Yi Xue Ban. 2005 Jul;36(4):519-21, 565.
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.
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.
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.
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.
为了更好地理解DNA引发特异性细胞毒性T淋巴细胞（CTL）免疫反应的机制，我们观察了DNA免疫后不同时间注射部位的局部浸润情况，并进一步研究了浸润细胞的特征。
通过苏木精-伊红（HE）染色观察DNA免疫后6小时、12小时以及1至6天注射部位的局部浸润情况。采用免疫组织学方法，利用小鼠树突状细胞标志物CD205、T淋巴细胞标志物CD4和CD8对浸润细胞进行进一步研究。
将phAFP注射到小鼠肌肉中可导致局部浸润。浸润在注射后3至6天达到峰值，并在肌肉内呈现为几个离散的细胞簇。浸润细胞中主要的细胞类型为巨噬细胞样细胞和淋巴细胞。免疫组织学染色显示有CD205+和CD4+细胞。在任何注射的肌肉中均可检测到CD4+细胞。CD205+细胞仅在24小时至第3天可见，出现时间晚于CD4+细胞且消失时间早于CD4+细胞。然而，未发现CD8+免疫染色阳性。
我们的研究结果表明，DNA免疫后局部浸润的特征不同于注射引起的炎症。CD205+细胞募集到注射部位表明树突状细胞和辅助性T细胞在DNA免疫中起重要作用。
