不同条件下NK细胞在小鼠黑色素瘤内的浸润

Infiltration by NK Cells in Melanoma under Different Conditions

目的比较DC及IL-2,IL-15维持NK细胞体内活性的作用效果。方法DAPI标记的NK细胞输入负瘤小鼠体内,同时分别给予DC、IL-2及IL-15,不同时间取肿瘤组织,荧光显微镜及电镜观察;MTT法测NK杀伤活性。结果DC可增强NK杀伤活性,NK/DC为1∶1时NK细胞杀伤活性强于NK/DC为10∶1时(P<0.05)。肿瘤组织内NK分布呈时间及剂量相关性,DC组NK浸润数量多于IL-2组及IL-15组,但无明显差异(P>0.05)。结论24小时内DC可维持并促进NK细胞活性,无需依赖外源性细胞因子。NK与DC的相互作用与剂量相关。

Objective To compare the infiltration in melanoma models and cytotoxicity of natural killer cells activated by dendritic cells, IL-2 and IL-15. Methods Inoculating B16 Melanoma cells in C57BL/6 mice＇s back to establish subcutaneous models. NK cells labled by DAPI were injected via the lateral tail vein. DC, IL-2 and IL-15 were given respectively. Tumor tissues were removed at different times after injection and processed for electron microscope and fluorescence microscope. Cytotoxicity was detected by MTT assay. Results Cytotoxicity of NK cells cultured with DCs was enhanced. NK cells had higher cytotoxicity when NK/DC ratio was 1 ： 1 than when it was 10：1 （P%〈0. 05）. NK cells and DCs were identified through electron microscope and necrosis of target cells was observed. Infiltration of NK cells was dose and time-dependent. More NK cells accumulated in tumors but not significantly when DCs were given compared to IL-2 or IL-15. Conclusion NK cells can be activated by DCs without exogenous cytotines. The activation between NK cells and DCs were related to their dose ratio.