可溶性HLA-G1、-G2的原核表达及其蛋白质产物的功能检测  

Prokaryotic expression and characterization of soluble HLA-G1 and soluble HLA-G2

作　　者：池永斌[1] 范丽安[1] 

机构地区：[1]上海第二医科大学上海市免疫学研究所,上海200025

出　　处：《现代免疫学》2005年第4期293-296,314,共5页Current Immunology

基　　金：国家自然科学基金资助项目(30371350);上海市科委重点项目(02DJ14054)

摘　　要：sHLA-G存在于整个妊娠期母胎接触面及母体血循环中,目前被认为是妊娠期一种特异性免疫抑制分子。实验将sHLA-G1、sHLA-G2基因克隆于原核表达载体pET-28a中,转化大肠杆菌BL21(DE3)宿主菌,经IPTG诱导实现目标融合蛋白的高效表达,并通过Ni2+-NTA柱纯化、蛋白质透析梯度复性获得纯化的His-sHLA-G1、His-sHLA-G2融合蛋白。融合蛋白再经凝血酶酶切、苯甲脒琼脂糖凝胶吸附去除6-His标签后,用于体外功能鉴定。结果显示:sHLA-G2与sHLA-G1一样,同样具有抑制T细胞增殖、抑制NK细胞杀伤活性的功能,提示sHLA-G2为一种免疫致耐分子。Being present in the maternal-fetal interface and the maternal blood circulation, soluble HLA-G are now regarded as a specific immuno-inhibitor during pregnancy. In order to study the biological characteristics of soluble HLA-G1 （sHLA-G1） and soluble HLA-G2 （sHLA-G2）, the complete coding sequences of sHLA-G1 and sHLA-G2 were cloned into expression vector pET-28a, and then expressed in E.coli BL21 （DE3）. After induction with 1 mmol/L of IPTG at 37℃ for 4 h, the fusion proteins His-HLA-G1 and His-HLA-G2 were obtained in large amounts, and then the fusion proteins were purified by Ni^2＋-NTA column. Followed by a series of processes, such as dialysis, concentration and thrombin digestion of proteins, pure sHLA-G1 and -G2 in active forms were obtained. These results showed that sHLA-G2, just as the same as sHLA-G1 may serve as a immuno-tolerance inducing molecule, which was proved to have the ability to inhibit the cytotoxicity of NK cells and the proliferation of activated T cells.

关 键 词：可溶性HLA—G NK细胞 T细胞 免疫耐受 

分 类 号：R730.5[医药卫生—肿瘤]