H_(22)源exosomes瘤苗在小鼠体内的抗肿瘤及免疫调节作用

Antitumor and immune regulating effect of exosomes cancer vaccine derived from H_(22) in vivo

目的:探讨exosomes瘤苗对小鼠免疫功能及肝癌移植瘤生长的影响。方法:从培养的小鼠肝癌H22细胞上清中分离exosomes瘤苗,以H22细胞接种BALB/c小鼠建立动物模型,随机分为exosomes瘤苗接种组及PBS对照组。15d后处死小鼠,测量移植瘤体重量,计算抑瘤率;分别称取脾重、胸腺重,检测荷瘤小鼠脾脏指数和胸腺指数;用MTT法检测小鼠脾淋巴细胞增殖情况和细胞毒活性;酶连免疫吸附试验(Enzyme-linked immunoabsorbent assay,ELISA)检测脾淋巴细胞产生IL-2、INF-γ的能力。结果:接种exosomes瘤苗能显著抑制肿瘤生长,抑瘤率达42.26%;与对照组比较,实验组荷瘤鼠胸腺指数、脾指数显著提高(P<0.05);exosomes促进脾淋巴细胞增殖并增强其细胞毒活性,同时脾淋巴细胞培养上清中IL-2、INF-γ的水平升高。结论:exosomes瘤苗可能通过增强小鼠的免疫功能抑制小鼠肝癌移植瘤生长。

Objective： To investigate the influence of exosomes tumor vaccine on immunity and grouth of mouse hepatocellular carcinoma xenograft in mice. Methods： Hepatoma carcinoma H22 cell-derived exosomes were isolated and purified from the culture supematants by serial ultracentrifugation and sugar density uhracentrifugation.BALB/c mice inoculated with H22 cell were used as tumor models. The mice inoculated with H22 cell were divided into two groups at random：exosomes group and PBS control group. 15 days later,the mice were killed; then the tumor inhibitory rate was calculated. The spleens and thymuses were weighed, and the effect of exosomes on spleens and thymus index was determined.The proliferation and cytotoxicity of splenocytes were detected by MTT assay.The level of IL-2 and INF-γ in splenocyte culture supernants was detected by enzyme-linked immunoabsorbent assay（ ELISA ）. Results： Exosomes cancer vaccine depressed the growth of tumor remarkably, and its tumor inhibitory rate was 42.38%.Compared with these in PBS control group,the spleen indexes and thymus indexes of mice bearing tumor in experiment group were increased（P〈0.05 ）.Exosomes could induce lymphocyte proliferation, and generate strong specific cytotoxic spleen lymphocyte response .The level of IL-2 and INF-γ was increased after vaccination. Conclusion： Vaccination of H22 cell-derived exosomes may enhance immune function and depresse the growth of hepatoma carcinoma H22 xenografts in mice.