甲基-β-环糊精对T细胞膜分子CD69和GM1表达的影响

The expression of CD69 and GM1 on T cells induced by Methyl-β-cyclodextrin (MβCD)

目的:探讨甲基-β-环糊精(M ethyl--βcyc lodextrin,MβCD)去除细胞膜胆固醇诱导人外周血T细胞CD69和单唾液酸四己糖神经节苷脂(Ganglioside GM1,GM1)的表达及机理。方法:用高浓度MβCD(10 mmol/L)处理PBMC,或预先加阻断剂PD98059或/和LY294002,用流式细胞术检测T细胞GM1及CD69的表达;免疫印迹法检测MβCD诱导的CD3+T细胞中ZAP-70的磷酸化。结果:MβCD(10 mmol/L)处理PBMC 30分钟,GM1在T细胞上即有高水平表达(>90%),CD69于处理后2小时高水平表达(>80%);预先加入PD98059或LY294002均能够大部分阻断MβCD诱导的T细胞CD69表达,部分阻断GM1表达,联合应用两种抑制剂也不能完全阻断GM1的表达;MβCD能够促进CD3+T细胞中ZAP-70分子的酪氨酸磷酸化。结论:MβCD能够促进T细胞GM1及CD69的表达;且这两种分子的表达可能与信号分子ZAP-70、MEK/ERK及PI3K有关。

Objectlve：To investigate expression and mechanisms of ganglioside GM1 （GM1）and CD69 on human T cells induced by plasma membrane cholesterol depletion with Methyl-β-cyclodextrin（ MβCD）. Methods：Human peripheral blood mononuclear cells were cultured with MβCD, or pretreated with PD98059 or/and LY294002. The expression of GM1 and CD69 on T cells induced by MβCD （ 10 mmot/L） and blocked with PD98059 or/and LY294002 were measured by flow cytometry. The tymsine phosphorylated ZAP-70 in the CD3^ ＋ T cells induced by MβCD was detected by immunoblotting. Results ：After 30 min treated with MβCD, GM1 on T cells increased significantly （ 〉 90% ）, after two hours CD69 began expressed highly （ 〉 80% ）. The expression of CD69 on T cells was mostly,but GM1 was only partially inhibited by PD98059 or LY294002. The expression of GM1 was still only partially inhibited when the two inhibitors were used together. The tyrosine phosphorylation of ZAP-70 in CD3 ^＋ T cells was enhanced by MβCD. Conclusion：Higher concentration of MβCD （ 10 mmol/L） could induce expression of GM1 and CD69 on T cells, and the signaling molecules ZAP-70, MEK/ERK and PβK might be involved.