RNA编辑酶ADAR1在小鼠细胞免疫应答中的作用研究

Function of RNA Editing Enzyme ADAR1 in Cellullar Immunologic Response in Mouse

目的通过siRNA质粒转染小鼠淋巴细胞,降低RNA编辑酶ADAR1的表达,观察其对淋巴细胞免疫功能的影响。方法反复冻融人肝癌细胞株,制备肿瘤细胞可溶性抗原,将分离出的小鼠原代淋巴细胞以ADAR1siRNA质粒转染,然后以肿瘤细胞可溶性抗原致敏,以此作为实验组;设原代培养未经转染的致敏小鼠淋巴细胞为对照组,采用细胞毒性实验检测ADAR1对淋巴细胞免疫功能的影响。结果实验组淋巴细胞对靶细胞的杀伤作用明显弱于对照组(P<0.05)。结论RNA编辑酶ADAR1在小鼠细胞免疫中有重要作用,下调RNA编辑酶ADAR1表达可以减弱淋巴细胞的杀伤作用。

Objective To investigate the effect of RNA editing enzyme ADAR1 on the function of lymphocyte immune by transferring mouse lymphocytes with plasmid of sense siRNA and by suppressing the expression of ADAR1. Methods The cell strains of human hepatic cellular carcinoma （HCC） were frozen and thawed repeatedly to prepare for tumor soluble antigen. The isolated mouse lymphocytes, which were transferred with anti-sense siRNA plasmid of ADAR1 and were sensitized with soluble tumor antigen were used as the study group; those which were not transferred but were sensitized were used as the control group. The 3 H-TdR adulteration experiment was used to test the sensitivity of lymphocytes. The effect of ADAR1 on lymphocyte immunity was detected by lymphocytotoxicity tests. Results The observation of the isolated lymphocytes implied that the growth cycle of lymphocyte was 10-14 days. The 3 H-TdR adulteration experiment showed the result was optimal. The number of HCCs decreased significantly for both of the groups compared with those in the blank holes, but the amplitude was much larger in the control group. The expression of ADAR1 in lymphocytes of the study group was significantly lower than that of the control group, which demonstrated that the RNA plasmid of ADAR1 suppressed the expression of ADAR1 in sensitized lymphocytes and the suppressing rate of the control group （87.47±4.62）% was significantly higher than that of study group （53. 19±3. 95）%. The function of lymphocytes killing target-cells in the study group was significantly inferior to that of control group （P〈0.05）. Conclusion RNA editing enzyme ADAR1 may play an important role in mouse cellullar immunologic response and it is possible to attenuate the cell-immune response by depressing the expression of ADAR1.