【摘要】 目的　阐明IL 15在NK细胞功能调节中的作用及信号转导途径的活化。方法　直接免疫荧光证实NK 92细胞膜表面表达IL 15Rα链 ,制备NK 92细胞的全细胞提取物进行Westernblot检测IL 15诱导的信号转导途径 ,MTT方法评价IL 15对NK细胞增殖和细胞毒能力的调节作用。结果　NK 92细胞表面存在IL 15Rα链的表达 ,构成IL 15与NK相互作用的分子基础。在IL 2依赖性NK细胞系NK 92中 ,较低剂量的IL 15 (2 5～ 10 0U/ml)可以完全替代IL 2以维持NK细胞的杀伤活性并对NK细胞的生长起促进作用。免疫印迹显示IL 15迅速活化ERK1/ 2 (extracellularregulatedkinase 1and2 )信号途径 ,而其它信号分子 (STAT1、STAT3、STAT6、P38MAPK、PI 3K、NF κB)并不被IL 15活化 ,提示ERK1/ 2是IL 15调节NK细胞功能中重要的信号分子。结论　IL 15对NK细胞具有强大的调节作用 ,IL 15通过ERK1/ 2信号途径完成对NK细胞活性的调节。更多还原

【Abstract】 Objective To elucidate the roles and signaling mechanisms of IL-15 in regulating NK cell functions in vitro. Methods Cell extracts from NK cell line NK-92 was used with Western blot to identify the activated signaling pathways involved in IL-15 induction. A MTT assay was applied to evaluate the effect of IL-15 on NK cytotoxicity and proliferation. The presence of IL-15Rα chain on NK cell line surface was proved by a direct fluorescence staining. Results IL-15Rα was constitutively expressed on NK-92 cell line surface as detected by a direct fluorescence staining which provided the molecular basis for interaction between IL-15 and NK cells. IL-15 retained lytic potential and enhanced cell proliferation at a low concentration of 25-100U/ml compared with IL-2 in IL-2 dependent NK-92 cells, but significantly augmented NK cytotoxicity than IL-2 at a higher dose of 1000U/ml. Western blot analysis showed that IL-15 rapidly induced phosphorylation of ERK1/2 (extracellular regulated kinase 1 and 2) but not other signaling proteins including STAT1, STAT3, STAT6, NF-κB, P38 MAPK in NK-92 cells, indicating a key role of ERK1/2 in transducing signals by IL-15 in NK cells. Conclusion IL-15 served as an alternative cytokine in sustaining NK proliferation and cytotoxicity in IL-2 dependent NK cell line NK-92 through ERK1/2 signaling pathway played. [更多还原