吲哚胺2，3双加氧酶表达对人胃癌细胞免疫逃逸的影响  

Tumor immune escape of a gastric cancer cell line expressing indoleamine 2,3-dioxygenase （ IDO ）

作　　者：王学军[1] 于津浦[2] 张汝鹏[1] 孙敬岩[1] 姚周佳[1] 任秀宝[2] 

机构地区：[1]天津医科大学附属肿瘤医院胃部肿瘤科天津市肿瘤防治重点实验室,300060 [2]天津医科大学附属肿瘤医院免疫室,300060

出　　处：《中华普通外科杂志》2009年第12期1006-1010,共5页Chinese Journal of General Surgery

基　　金：基金项目：天津市卫生局科技基金（05kyz86）

摘　　要：目的探讨转染人吲哚胺2，3双加氧酶（IDO）基因的胃癌细胞系的IDO表达与免疫逃逸的关系。方法根据IDO基因编码序列，构建真核表达载体pIRES2-EGFP—IDO，电转染胃癌BGC-823细胞，用G418筛选稳定表达IDO细胞株。用RT—PCR和Western blot检测其IDO mRNA和IDO蛋白表达，测定培养上清中色氨酸和犬尿氨酸的水平。分离胃癌患者外周血T细胞，与转染细胞及加入1甲基色氨酸（1-MT）的细胞共孵育，检测对细胞毒性T淋巴细胞（CTL）和T细胞增殖的影响。结果pIRES2-EGFP—IDO真核载体经酶切验证并测序后证实连接成功。稳定表达IDO的BGC-823细胞IDO mRNA明显高于未转染组和对照组，并有IDO蛋白表达。转染组和未转染组色氨酸水平分别为（3．23±0．53）mg／L、（6．03±0．51）mg／L（t=13．32，P=0．000），犬尿氨酸浓度分别为（4．84±0．11）mg／L、（1．83±0．10）mg／L（t=42．916，P=0．000）。转染IDO组、1-MT逆转组、转染空质粒组、BGC-823组之间对T淋巴细胞增殖抑制相比差异均有统计学意义（F=114．817，P=0．000），转染IDO组和1-MT逆转组抑制率明显高于转染空质粒组及BGC-823组，同时逆转组抑制率低于转染IDO组（P〈0．05）。4组CTL杀伤活性之间相比差异均有统计学意义（F=397．449，P=0．000）。转染IDO组和1-MT逆转组杀伤活性明显低于转染空质粒组及BGC-823组，同时逆转组CTL杀伤活性也明显高于转染IDO组（P〈0．05）。结论IDO转染胃癌细胞后显示IDO抑制了T细胞的增殖和CTL活性，参与胃癌的免疫逃逸作用。Objective To study tumor immune escape in a gastric carcinoma cell line expressing human indoleamine 2,3-dioxygenase（IDO）. Methods Human IDO gene was cloned by RT-PCR and the vector for pIRES2- EGFP-IDO was constructed. BGC-823 cells were transfected with the plasmid using electroporation. The integrated INDO genes were detected by RT-PCR and Western blot. The enzyme activity of IDO were measured. T cells from gastric cancer patients were coeultured with BGC-823 transfected with IDO or added with 1-MT circumstance, T cell-mediated cytotoxicity and proliferation were detected. Results Higher level expression of IDO mRNA and IDO protein was detected in tumor cells transfected with IDO gene. The level of kynurenic acid was higher in transfected cells compared with no-transfected group （4. 84 ± 0. 11 ） mg/L vs. （ 1. 83 ± 0. 10） mg/L, P = 0. 000. The eytotoxieity ratio of the IDO transfected group and transfeeted group with I-MT circumstance （ 1-MT group） was lower than control group （ P 〈 0. 05）. The inhibition rate of transfected group with 1-MT group was higher than control group （ P 〈 0. 05 ）. Conclusion Gastric cancer cell lines encoded with IDO inhibits T cell-mediated eytotoxicity and proliferation.

关 键 词：胃肿瘤 肿瘤逃逸 双加氧酶类 T淋巴细胞 细胞毒性 转染 

分 类 号：R686[医药卫生—骨科学]