金纳米棒标记的人CIK细胞用于胃癌靶向光声成像与免疫治疗

Using human CIK cells labeled with gold nanorods for targeted photoacoustic imaging and immunotherapy of gastric cancer

目的:利用金纳米棒标记的人细胞因子诱导杀伤细胞(CIK)主动靶向体内胃癌细胞的特性,实现胃癌的局部光声成像,观察金纳米棒在胃癌组织中的分布,测量血清中细胞因子浓度变化。方法:取健康志愿者的全血提取外周血单个核细胞,在多种细胞因子的诱导下扩增出CIK细胞;采用种子合成法制备金纳米棒并对其表面进行二氧化硅修饰与表征;利用胃癌细胞系MGC803细胞建立裸鼠胃癌皮下瘤模型;制备金纳米棒标记的CIK细胞,尾静脉注射进入荷胃癌的裸鼠模型,注射后不同时间点,进行光声成像观察金纳米棒标记的CIK细胞在肿瘤部位的分布;注射后3 d,收集裸鼠血清,测量IL-2、IL-17、γ-IFN的浓度,评判免疫治疗效果。结果:CIK细胞成功制备;制备的金纳米棒长为60 nm,宽为8 nm,二氧化硅厚度为20 nm;制备的金纳米棒被人CIK细胞内吞;金纳米棒标记的人CIK细胞能够主动靶向体内胃癌组织,在胃癌组织中大量聚集,呈现出增强的光声成像信号;细胞因子IL-2、IL-17与γ-IFN的浓度显著升高(P<0.05)。结论:金纳米棒标记的CIK细胞能够主动靶向体内胃癌组织,高效聚集并呈现出增强的光声成像信号,同时升高血液中细胞因子水平,增强免疫治疗功能。

Objective： Using property of human cytokine-induced killer cells （CIK） targeting gastric cancer cells to achievie local photoacoustic imaging of gastric cancer, to observe distribution of gold nanorods in gastric cancer tissues and to measure concentration changes of cytokines in serum. Methods ： Peripheral blood monocuclear cells were extracted from whole blood of healthy volunteers and CIK ceils were amplified induced under inductions of multiple cytokines. A seed synthesis method was used to prepare gold nanorods and to modify their surfaces with silicon dioxide （20 nm thick）. A nude mouse model with subcutaneous xenograft of gastric tumor was etablished using gastric cancer MGC803 line cells. The CIK ceils labeled with gold nanorods were injected into caudal vein of the nude mice with xenograft of gastric cancer and distribution of the CIK ceils labeled with gold nanorods in the tumor tissues was observed with photoacoustic imaging at various time points of the injection. After 3 days of the injection, concentrations of IL-2, IL-7 and Y-IFN in serum of the nude mice were detected by ELISA assay. Results： CIK cells and gold nanorods were successfully made. The gold nanorods with 60 nm long and 8 nm wide were swallowed by the human CIK. The human CIK cells labeled with the goldnanorods actively targeted gastric cancer tissues, a large number of them accumulated in the gastric cancer tissues and en- hanced signaling of photoacoustic imaging was presented. Concentrations of cytokines IL-2, IL-7 and Y-IFN significantly increased, and were higher than those in the control group （ P 〈 0.05 ）. Conclusion ： The CIK cells labeled with the gold nanorods could actively target gastric cancer tissues, efficiently collect and present enhanced signaling of photoacoustic im- aging. At the same time, cytokine level in blood could be elevated and curative efficacy of the immunotherapy could be enhanced.