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目的超抗原能诱导 T细胞凋亡 ,但其作用机制尚未阐明 ,Fas系统与 Ca2 +在其中的作用尚待进一步研究。方法超抗原金黄色葡萄球菌肠毒素 A(SEA)诱导人外周血建立的短期 SEA反应 T细胞系凋亡 ,1.8%琼脂糖凝胶 DNA电泳于不同时间观察凋亡的特征条带 ;FCM检测 Fas、Fas L 的表达量变化 ,Fura- 2 / AM荧光指示剂检测胞浆游离 [Ca2 + ]i的变化。结果使用 FCM特异性检测凋亡亚 G0 / G1峰大小及 1.8%琼脂糖凝胶电泳检测凋亡 DNA梯状图谱证明 ,SEA能诱导短期 SEA反应 T细胞凋亡 ,其凋亡的时间与程度与 SEA的剂量有关。SEA1μg/ ml建立的短期 SEA反应 T细胞对 SEA1μg/ml的再次刺激 ,凋亡量随作用时间的延长而增多 ,在作用的第 16 h最高 ,达 5 8%。 FCM间接荧光染色法检测发现 ,Fas及Fas L 亦随 SEA作用时间的延长而表达增多 ,16 h时表达最多 ,分别为 92 %和 6 0 %。用 Fura- 2 / AM荧光指示剂检测 ,此时细胞胞浆 [Ca2 + ]i已从刺激前的 (2 90± 33) nm ol/ L 上升到 (6 80± 16 ) nmol/ L。结论 Fas系统与 SEA诱导的 T细胞凋亡密切相关。换言之 ,Fas系统在超抗原诱导 T细胞凋亡中起作用 ,而胞浆 [Ca2 + ]i升高与 SEA诱导的凋亡 T细胞 DNA断裂及其它凋亡形态变化有关。
The purpose of superantigen can induce T cell apoptosis, but its mechanism of action has not been elucidated, Fas system and Ca2 + in which the role remains to be further studied. Methods The superantigen Staphylococcus aureus enterotoxin A (SEA) induced apoptosis in short-term SEA-reactive T cells in human peripheral blood. The characteristic bands of apoptosis were observed at different times by 1.8% agarose gel electrophoresis. The expression of Fas , The change of Fas L expression, Fura-2 / AM fluorescent indicator of cytoplasmic free [Ca2] i change. Results The apoptotic subcellular G0 / G1 peak detected by FCM and the apoptotic DNA ladder detected by 1.8% agarose gel electrophoresis demonstrated that SEA could induce the apoptosis of T cells in short-term SEA response and the time and degree of apoptosis SEA dose related. SEA1μg / ml established short-term SEA response T cells SEA1μg / ml of re-stimulation, the amount of apoptosis increased with the duration of action, the role of the highest 16h, up to 58%. FCM indirect staining showed that the expression of Fas and Fas L increased with the prolongation of SEA, and reached the peak at 16 h, which were 92% and 60% respectively. The amount of [Ca2 +] i in cytoplasm increased from (2 90 ± 33) nm ol / L to (6 80 ± 16) nmol / L before stimulation with Fura-2 / AM fluorescent indicator. Conclusion The Fas system is closely related to the apoptosis of T cells induced by SEA. In other words, Fas system plays a role in the superantigen-induced apoptosis of T cells. Elevated [Ca2 +] i in the cytoplasm is related to DNA fragmentation and other morphological changes of apoptotic T cells induced by SEA.