超抗原SEA对K562细胞诱导脐带血单个核细胞上CD3ε链表达的影响

Effect of superantigen SEA on the CD3ε chain expression on cord blood mononuclear cells stimulated by K562 cells

目的:探讨金黄色葡萄球菌肠毒素A(SEA)对K562细胞诱导正常人脐带血单个核细胞(MNCs)中CD3ε链基因表达的影响。方法:常规分离4例脐带血单个核细胞,分别与抗CD3单克隆抗体(mAb)、单纯K562细胞、单纯SEA以及SEA联合K562细胞共培养,诱导MNCs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cDNA,以β2微球蛋白基因作为内参照,采用实时荧光定量PCR检测在各组MNCs中CD3ε链基因的表达,并根据公式2-△△C t对CD3ε链表达的差异倍数进行相对定量分析。结果:K562细胞组MNCs中CD3ε链基因表达的水平略有降低,抗CD3 mAb组、SEA组、SEA联合K562细胞组的诱导活化的MNCs中CD3ε链基因的表达均有增强,而SEA联合K562细胞组MNCs中CD3ε链基因的表达明显高于单纯SEA组(P<0.01)。结论:超抗原SEA可以增加K562细胞在体外诱导脐带血MNCs中CD3ε链基因的表达。

AIM： To explore the effect of staphylococcal enterotoxin A（SEA） on CD3ε chain expression on mononuclear cells in cord blood,which were stimulated by K562 cells.METHODS： The anti-CD3 antibodies（mAb）,K562 cells,SEA or both SEA and K562 cells were cocultured with mononuclear cells（MNCs） from four normal human cord blood for 48 hours respectively,Real-time PCR with SYBR GreenⅠtechnique was used to detect expressed level of CD3ε on MNCs in cord blood and set up a blank control group.Relative changes in expression level of CD3ε chain were indicated by the 2-△△Ct method between each group and the control group.β2-microglobulin gene（β2M） was used as an endogenous reference.RESULTS： The expressed level of CD3ε chain on MNCs was slightly decreased in K562 cell group and were increased in the anti-CD3 antibodies mAb group,SEA group,both of SEA and K562 cell group respectively.The expressed level of CD3ε chain in both SEA and K562 group was significantly higher than that in the SEA group（P0.01）.CONCLUSION： Superantigen SEA can enhance the expressed level of CD3ε chain on MNCs stimulated by K562 cells.