肝癌BEL7402细胞N－糖苷型糖蛋白质对NK细胞杀伤活性的影响

Effect of hepatoma─associated N─glycosylated glycoprotein on the cytotoxicity of NK cells

在体外培养和扩增肝癌ＢＥＬ７４０２细胞株，加入Ｔｒｉｓ─ＨＣｌ溶液超声粉碎细胞膜，提取碳水化合物粗提液。应用ＣｏｎＡ─Ｓｅｐｈａｒｏｓｅ４Ｂ亲和层析方法，分离出一种含Ｎ─糖苷型寡糖结构的糖蛋白质，分子量约为７５ｋｄ。这种糖蛋白质对正常人外周血ＮＫ细胞杀伤靶细胞Ｋ５６２细胞的活性有明显抑制作用。结果提示肝瘤细胞异常糖基化的糖蛋白质可能与肿瘤患者免疫功能低下有关。

iver cancer cells(BEL7402 cell line)were cultured in vitro, harvested and then homogenized in Tris─HCl buffer solution to prepare extracts of carbohydrate. The glycoproteins were isolated from the extractsby Con A affinity chromatography and other biochemical methods. On SDS─PAGE, a glycoprotein was seenwith a molecular weight of 75 KD. The results of LDH─release assay suggested that the glycoprotein couldabolish the cytotoxicity of NK cells against its target cells.