IL-12与IL-18在体外培养系统中诱导肿瘤特异性CTL杀伤活性的比较

Comparison of cytotoxicity of tumor specific CTL induced by IL-18 and IL-12 in cell co-culture system in vitro

目的:分别应用重组人白细胞介素12(rhIL-12)及重组人白细胞介素18(rhIL-18)在体外培养系统(CCs)中诱导肿瘤特异性细胞毒性T淋巴细胞(CTL),比较IL-18与IL-12诱导的肿瘤特异性CTL的杀伤活性,探索IL-18的抗肿瘤作用机制。方法:采用Stem SepTM免疫磁性细胞分离法分离人外周血NK细胞、T细胞及DCs细胞,流式细胞仪分析细胞表型,125I-UdR标记的细胞毒实验检测杀伤活性。结果:在CCs中、在肿瘤抗原存在的条件下,rhIL-18和rhIL-12均能诱导产生针对U251、MCF7特异性CTL,其作用能力与rhIL-18和rhIL-12的浓度呈剂量依赖关系,但rhIL-18诱导肿瘤特异性CTL的作用明显高于rhIL-12(P<0.01);rhIL-18和rhIL-12在诱导肿瘤特异性CTL过程中具有协同作用,两者联合应用诱导肿瘤特异性CTL的能力明显高于单独应用rhIL-18和rhIL-12(P<0.01)。结论:rhIL-18和rhIL-12在CCs中均能够诱导并促进CTL介导的肿瘤特异性杀伤效应,rhIL-18诱导的肿瘤特异性CTL的能力明显高于rhIL-12,两者在诱导肿瘤特异性CTL过程中具有协同作用。

Objective To compare the efficiency of IL-18 and IL-12 in inducing the tumor specific CTL in vitro, and test the cytotoxicities of tumor specific CTL induced in the same culture system with IL-18 or IL-12. Methods The NK ceils, T ceils and dendritic ceils were separated from fresh PBMNCs by using the Stem Sep^TM immunomagnetic beads. Cell phenotypes of the purified cell populations were identified with FCM technique. The cell co-culture system was established as follows： the cell preparations in which definite cell subset had been deleted was cocultivated with mitotic-inactivated tumor cells in the presence of rhlL-18 and/or rhlL-12. Cytotoxicities of the various effector cell preparations to a series of tumor cell lines were examined by the isotope releasing assay. Results In the cell co-culture system in vitro, rhlL-18 or rhlL-12 alone and dose-dependently induced tumor soecific cvtotoxicities. The level of cvtolvtic activity of the tumor specific CTL induced by IL-12 was substantiallyinferior to that induced by IL-18 （P〈0.01）. Conclusion These results suggest that IL-12 does not induce tumorspecific CTL as efficiently as IL-18 does in this co-culture system under these conditions, but the synergistic effect could be observed during administration of IL-18 and rIL-12.