中文摘要：

目的 探讨体外转录法合成的小干扰RNA（siRNA）对大鼠淋巴细胞白细胞介素（IL）-2基因的表达和功能的影响。方法 设计并合成3条siRYA（siRNA-1、siRNA-2、siRNA-3）在阳离子脂质体的介导下转染淋巴细胞。于转染后0、24、48h收集细胞，用半定量逆转录-聚合酶链反应（RT-PCR）方法检测IL-2mRNA的变化；酶联免疫吸附试验（ELISA）方法检测IL-2表达的变化。结果 体外合成的3条siRNA通过脂质体转染淋巴细胞后，均能不同程度地抑制I[,-2的表达。转染后24h的ELISA方法检测显示siRNA-1、siRNA-2、siRNA-3组的抑制率分别为（79．20±1．83）％、（66．50±1．42）％、（43．90±1．22）％，以siRNA-1的IL-2抑制作用最强。半定量RT-PCR方法检测显示siRNA-1、6iRNA-2、siRNA-3转染后的IL-2mRNA均受到不同程度的抑制，其中siRNA-2组的抑制作用最明显（82，10±1．85）％。结论 siRNA可特异性的抑制淋巴细胞IL-2基因的转录和表达，为研究siRNA在移植免疫耐受及防移植物抗宿主病（GVHD）方面的应用提供了依据。

英文摘要：

Objective To investigate the expression of IL-2 molecule in human lymphecytes by siRNA. Methods Three different siRNA （ siRNA-1, siRNA-2, siRNA-3 ） were designed, synthesized and transfected into freshly isolated rat lymphocytes with cationic liposome. At 0,24 and 48 h post transfection, the IL-2 protein and mRNA levels in the culture were detected by ELISA and semi-quantitative RT-PCR respectively. Results Different siRNA showed different reduction in the IL-2 expression. At 24 h post transfection,the degrees of reduction with siRNA-1, siRNA.2 and siRNA-3 were （79. 20 ± 1.83）%, （66.50 ± 1.42 ） % and （ 43.90 ± 1.22） %, respectively as compared with the controls （ P 〈 0.001 ）. siRNA-1 was the most efficient. Semi-quantitative RT.PCR assay revealed that IL-2 mRNA levels were decreased after transfection. At least 4-fold of reduction in siRNA-1 group occurred at 48 h post transfeetion as compared with the controls （ P 〈0.001 ）. Conclusion Three different siRNA could reduce the expression of IL-2 mRNA and IL-2 levels. The silencing effect on IL-2 mRNA induced by siRNA may contribute to the tolerance, siRNA may be useful for further study on GVHD after organ transplantation.