结肠癌源性exosomes的分离及其相关免疫学性质

目的分离结肠癌细胞株的exosomes,并分析其在致敏抗原呈递细胞及激活相关效应细胞过程中的作用。方法差速离心法分离体外培养的正常exosomes和经热休克处理的sw1116细胞(Heat shocked sw1116,HS-sw1116)分泌的exosomes(Heat shocked exosomes,HS-Exo),并在电子显微镜下观察exosomes和HS-Exo的形态结构;SDS-PAGE初步分析exosomes和HS-Exo的蛋白组分,CCK-8法检测其促外周血单个核细胞(Peripheral blood monouclear cells,PBMCs)增殖的能力。结果电子显微镜观察,exosomes和HS-Exo的形态学结构无明显差异,其平均直径约为150 nm;exosomes和HS-Exo的蛋白条带分布情况基本相同,在高相对分子质量区域蛋白分布较多;exosomes比sw1116细胞更易引起PBMCs的增殖反应,HS-sw1116细胞和HS-Exo促PBMCs增殖的作用比sw1116细胞和exosomes更明显(P<0.05)。结论结肠癌sw1116细胞株可分泌exosomes,其比肿瘤细胞更易引起PBMCs的增殖,热休克处理可进一步增强细胞和exosomes的促PBMCs增殖的能力,exosomes在结肠癌免疫治疗方面具有重要的应用价值。

Isolation and immunologic characteristics of exosomes derived from colon carcinoma cells

Objective To isolate exosomes from colon carcinoma cell strain and analyze its role in sensitization of antigenpresenting cells(APCs)and activation of effecter cells.Methods Normal exosomes cultured in vitro and heat shocked exosomes(HS-Exo)were isolated by differential centrifugation and observed for morphology by electron microscopy.The protein components of exosomes and HS-Exo were preliminarily analyzed by SDS-PAGE,and their abilities in promoting the proliferation of peripheral blood monouclear cells(PBMCs)by CCK-8 method.Results Normal exosomes and HS-Exo showed no significant difference in morphology under electron microscope,of which the mean diameter was about 150 nm.The distributions of protein bands of exosomes and HSExo were similar,which were mainly in the zones with high relative molecular masses.Compared with sw1116 cells,exosomes promoted the proliferation of PBMCs easily.However,HS-sw1116 cells and HS-Exo were superior to sw1116 cells and exosomes in promoting the proliferation of PBMCs,respectively.Conclusion Colon carcinoma sw1116 cells secreted exosomes which induced the proliferation of PBMCs more easily as compared with the cells.Heat shock enhanced the abilities of sw1116 cells and exosomes in promoting the proliferation of PBMCs.The exosomes played an important role in immunotherapy of colon carcinoma.