目的：探讨细胞因子IL-21 对CIK 细胞体外杀伤食管癌EC9706 细胞活性的影响，并初步分析其可能的分子机制。方法：体外无菌分离人外周血单个核细胞，分别进行常规培养和加IL-21 培养CIK细胞。流式细胞术检测2 种培养CIK细胞的免疫表型，LDH释放法检测2 种培养CIK 细胞杀伤食管癌EC9706 的活性，ELISA 法检测2 种CIK 细胞培养上清液IFN-γ 浓度。结果：常规培养和加IL-21 培养的2 种CIK细胞增殖数量无明显差异。加IL-21 培养的CIK细胞CD3+CD56+细胞比例、CD3+细胞内颗粒酶B 和穿孔素表达率均显著高于常规培养CIK 细胞[(26.95±3.53)% vs (16.18±1.04)%，(33.29±2.30)% vs (23.58±2.28)%和(59.70±1.91)% vs (45.96±2.67)%，均P<0.05）。效靶比20∶1 和30∶1 时，加IL-21 培养的CIK细胞杀伤EC9706 细胞的活性均显著高于常规培养的CIK 细胞[20∶1 时:(43.66±1.99)% vs (34.59±1.75)%；30∶1 时：57.52±2.15)% vs (42.23±1.87)%，均P<0.05]。加IL-21培养CIK细胞的上清液FN-γ 的浓度明显高于常规培养CIK细胞的上清液[(142.7±13.4) vs (42.6±3.3) ng/L，P<0.05]。结论：IL-21增加CD3+CD56+细胞比例和颗粒酶B及穿孔素的表达，提高CIK细胞分泌IFN-γ，从而增强CIK细胞对EC9706 细胞的杀伤活性。

Objective: To explore effect of cytokine interleukin 21 (IL-21) on the activity of cytokine-induced killer (CIK) cell killing in vitro the esophageal cancer EC9706 cell, and preliminarily to analyze its possible molicular mechanism. Methods: Human peripheral blood mononuclear cells were isolated with sterile operation in vitro,which were respectively cultured into CIK cells in routine medium or in routine medium plus IL-21. Flow cytometry assay was used to detect immunophenotypes of CIK cells cultured with the two medium. Lactate dehydrogenase (LDH) release method was used to exam the activities of the two cultured CIK cells killing the esophageal cancer EC9706 cell. Concentrations of IFN-γ in liquid supernatant cultured the two types of CIK cell were checked by ELISA. Results: There not were any significant difference of proliferation number of the CIK cells between routine culture and routine culture plus IL-21. Proportion of CD3+CD56+ cell, expression rates of granzyme B and perforin in CD3+ cell of the CIK cell cultured by routine medium plus IL-21 were evidently higher than those of the CIK cell cultured by routine medium (CD3+CD56+ cell: [26.95±3.53]% vs [16.18±1.04]%；granzyme B: [33.29±2.30]% vs [23.58±2.28]%；perforin: [59.70±1.91]% vs [45.96±2.67]%, all P<0.05). At effector/target ratio of 20∶1 and 30∶1,killing activities against the EC9706 cell of the CIK cell cultured with routine medium plus IL-21 were all remarkably higher than those of the CIK cell cultured with routine medium（at E/T 20:1 [43.66±1.99]% vs [34.59±1.75]%;at E/T 30∶1 [142.7±13.4]% vs [42.6±3.3]%，all P<0.05). Concentration of IFN-γ in liquid supernatant cultured the CIK cell in routine medium plus IL- 21 was obviously higher than that cultured the CIK cell in routine medium [(157.2±10.3) ng/L vs (46.2±4.3) ng/L，P<0.05]. Conclusion: IL-21 could enhance killing activity of the CIK cell against the esophageal cancer EC9706 cell through increasing proportion of CD3+CD56+ cell, expression rates of granzyme B and perforin in CD3+ cell as well as raising the secretion of IFN-γ by the CIK cell.

河南省卫生厅科技攻关项目资助（No. 201303222）