SEA联合K562细胞体外诱导正常人脐带血单核细胞TCRζ链表达的作用

Effect of SEA on the TCRζ chain expression of T cells stimulated by K562 cells in cord blood

目的:研究金黄色葡萄球菌肠毒素A(SEA)对K562细胞体外诱导脐血T细胞活化TCRζ链基因表达情况。方法:常规分离4例脐带血单核细胞,分别与抗CD3单克隆抗体、单纯K562细胞、SEA以及SEA联合K562细胞共培养,诱导T细胞活化增殖,并设空白对照组。刺激培养48 h后收集各组细胞提取mRNA并合成cD-NA,采用SYBR GreenⅠ荧光定量PCR和相对定量检测TCRζ链在不同组别T淋巴细胞中的表达情况,以β2微球蛋白基因(β2M)作为内参,根据相对定量公式:2-ΔΔCt计算TCRζ链表达差异倍数。结果:抗CD3单抗组、K562细胞组、SEA组、SEA联合K562细胞组诱导培养T细胞中TCRζ链表达差异倍数分别是(4.52±0.96)、(1.65±0.26)、(1.43±0.44)、(3.41±0.30),表明各组均有活化T细胞的作用,但各组TCRζ链表达水平有差异,其中SEA联合k562细胞组的T细胞ζ链基因表达均明显高于单纯k562组及单纯SEA组(P<0.01)。结论:超抗原SEA有助于增强K562细胞体外诱导T细胞活化作用。

Aim：To measure the expression of T lymphocyte-TCRζ chain gene in cord blood mononuclear cells which stimulated by K562 cells,SEA or both of them. Methods： Real-time PCR with SYBR GreenⅠtechnique was used for detecting TCRζ chain expression level in cord blood mononuclear cells from four normal individuals,which were induced by the anti-CD3 antibodies,K562 cells,SEA or both of K562 cells and SEA respectively at the beginning or for 48 hours.Relative changes in TCR ζchain expression level were indicated by the 2^-ΔΔCt method between each group and the control.β2-microglobulin gene（β2M） was used as an endogenous reference.Results： The expression level of TCRζ chain were（4.52±0.96）,（1.65±0.26）,（1.43±0.44）,（3.41±0.30） in four groups of the anti-CD3 antibodies,K562 cells,SEA,both of SEA and K562 cells respectively.This result showed that the activation of T cells in each group was induced.The expression level of TCRζ chain induced by both SEA and K562 was significantly higher than that of the K562 or SEA group（P0.01）.Conclusion：The superantigen（SEA） could enhance T cell activation stimulated by the K562 cells in vitro.This study should provide a new insight into the research on vaccine for chronic myelogenous leukemia.