中文摘要：

目的：获得纯化的DC—SIGN蛋白，为揭示DC—SIGN参与抗原提呈的机制，探讨宿主细胞DC—SIGN蛋白和HIV、HCV、结核杆菌等病原体的相互作用机制奠定基础。方法：人DC—SIGN的cDNA克降到pGEX—KG表达载体上。转化入E.coli中通过IPTG诱导。过度表达GST-DC—SIGN融合蛋白，并使用Glutathione—Sepharose 4B亲和层析柱提取得到纯化的DC—SIGN蛋白，最后通过SDS-PAGE和Western Blot方法进行检测和鉴定。结果：酶切鉴定证实DC—SIGN基因已插入原核表达载体pGEX—KG。重组表达质粒pGEX—KG-DC—SIGN在大肠杆菌BL21中成功表达了DC—SIGN融合蛋白，其分子质量约为44kU。结论：成功构建DC—SIGN原核表达重组质粒，并提取纯化出DC-SIGN原核蛋白，为下一步研究DC—SIGN的功能奠定了基础。

英文摘要：

Objective： To reveal the interaction between DC-SIGN on host cells and pathogens. Methods： Human DC-SIGN cDNA were cloned into prokaryotic vector pGEX-KG, and expressed as a fusion protein in E. coli BI.21 induced by IPTG. The expressed GST-DC-SIGN fusion protein were purified via GST-Sepharose 4B Column and identified by SDS-PAGE and Western blot. Results： Restriction enzyme digesting and DNA sequencing confirmed that the cDNA sequence of DC-SIGN had been correctly inserted into the multi-cloning site of pGEX-KG. The protein（44 kU） was identified by DC-SiGN polyclone antibody using Western blotting. Conclusion： DC- SIGN protein were purified successfully and it lays a foundation on the research of DC-SIGN.