B7转染白血病细胞K562的作用研究

The study of human leukemia cell K562 transfected with B7 gene

目的：探讨共刺激信号分子Ｂ７转化人白血病细胞株Ｋ５６２后，转化细胞的生物学性状变化及介导的免疫作用。方法：构建重组真核表达质粒ｐｃＤＮＡ３．１Ｂ７，转化人白血病细胞株Ｋ５６２，获得单个细胞克隆，观察Ｋ５６２－Ｂ７的生长周期，绘制生长曲线，检测Ｋ５６２－Ｂ７诱导Ｔ细胞分泌ＩＬ－２的情况。结果：ｐｃＤＮＡ３．１Ｂ７可在Ｋ５６２中稳定表达，Ｋ５６２－Ｂ７的生长增殖速度比野生型Ｋ５６２慢。在体外，Ｋ５６２－Ｂ７可诱导ＰＭＮＣ分泌ＩＬ－２，２４ｈ上清液中ＩＬ－２含量比Ｂ７阴性Ｋ５６２高１倍左右。结论：Ｂ７基因转入人白血病细胞株Ｋ５６２后，细胞本身增殖能力降低，且Ｋ５６２—Ｂ７可活化ＣＤ＋４Ｔ细胞分泌细胞因子ＩＬ－２，提高宿主抗肿瘤免疫能力。

Objective： To assess the potential of costimul atory signal molecule B7 in inducing immune effect and the biological alternatio n of K562-B7.Methods： First,insert B7 gene into eukaryotic expressionplasmid pcDNA3.1B7,then transfect K562 with plasmid pcDNA3.1B7 and select positi ve clone(K562-B7) by G418(600μg/ml).Finaly,analyse the ability of growth and pr oliferation of K562-B7,The secretion of IL-2 was also observed in vitro.Re sults： pcDNA3.1B7 can be stably expressed in K562,and K562-B7 grow more slo wly than wild K562.In addition ,IL-2 production per 24 hours in the supernatant stimulated by K562-B7 was about twice as much as that by B7 negative K562. Conclusio n： K562 transfected with B7 gene grow more slowly than K562 and K562-B7 can activate T cell to produce IL-2,and enhance anti-tumor immunity.