OVA基因修饰的树突状细胞疫苗抗裸鼠肺肿瘤效应研究

Anti-lung cancer effect of dendritic cell vaccine modified with OVA gene in nude mice

目的探讨OVA基因修饰的树突状细胞疫苗(DC-OVA)在肿瘤模拟抗原OVA(ovabumin)的裸鼠肺癌模型体内抗肺肿瘤的效应。方法裸鼠右肺原位接种携带OVA的Lewis肺癌细胞(Lewis lung cancer cell-OVA,LLC-OVA)悬液,建立裸鼠肺癌模型。获取DC,经基因转导制备DC-OVA疫苗。Western印迹法检测OVA蛋白的表达。获取T细胞,进而制备DC疫苗系统(DC-OVA/T)。CCK8试剂检测DC-OVA刺激后T细胞的增殖。模型建立2周后,尾静脉注射DC-OVA/T。Micro-CT扫描荷瘤裸鼠的胸部,观察肺部影像。H-E染色观察肺部及肿瘤组织形态结构。IHC方法观察脾、淋巴结、肿瘤组织中CD8的表达;观察肿瘤组织中SOX2、BMI1的表达。ELISA法检测血清中IL-12水平。结果 Western印迹法在样本中检测出清晰的OVA条带。DC-OVA强有效地刺激了T细胞的增殖(P<0.05)。DC-OVA/T治疗4周,疫苗组裸鼠肺micro-CT未见明显肿瘤阴影;取材,裸眼可见疫苗组病灶减小,H-E染色显示疫苗组的肿瘤组织较少,肺组织形态较完整。疫苗组裸鼠的脾、淋巴结、肿瘤组织内CD8阳性表达均明显高于对照组(P<0.05,P<0.05,P<0.01),肿瘤组织中的SOX2、BMI1阳性表达明显低于对照组(P<0.05,P<0.05);血清中的IL-12含量较对照组明显升高(P<0.001)。结论基因修饰的DC疫苗在裸鼠体内具有强大的抗肺癌效应,为临床治疗肺癌提供了新的实验依据。

Objective To investigate the anti-tumor effect of dendritic cell vaccine with OVA gene in nude mice. Methods The lung cancer model was induced by injection of Lewis lung cancer （LLC） cells with OVA suspension in the right lung of nude mice. The OVA gene was transducted into DC to prepare the DC vaccine （ DC-OVA）. Expression of OVA protein in DC-OVA was detected by Western blotting. The T cells were gained to construct DC-OVA/T vaccine system. T cell proliferation stimulated by DC-OVA vaccines was detected by Cell Counting Kit-8. Two weeks after the model was established, the mice were injected with DC-OVA/CTL through tail vein. The chest of mice was scanned by micro-CT to observe lung images. The lung specimens were stained by H-E Staining for pathological examination. The expressions of CD8 in spleen, lymph nodes and tumor tissue were detected by immunohistochemistry （IHC） ; the expressions of SOX2, BMI in tumor tissue were also detected by IHC; serum IL-12 was detected by ELISA kit. Results OVA stripes were observed clearly detected by Western blotting. The proliferation of T cell stimulated by DC-OVA was increased significantly （P 〈 0.05 ）. Micro-CT did not show the image of lung cancer after 4 weeks DC vaccine treatment. Macro and micro morphological examination showed attenuated lesions of lung cancer in DC-OVA group. The expressions of CD8 in spleen, lymph nodes, and tumor tissues of nude mice in DC vaccine group were higher than those in control group （ P 〈 0. 05, P 〈 0. 05, P 〈 0.01 ）. The expressions of SOX2, BMI1 in tumor tissue were lower in DC vaccine group than in control group （P 〈0. 05, P 〈0. 05）. The serum levels of IL-12 was higher in DC vaccine group than that in control group （P 〈 0. 001 ）. Conclusion DC vaccines modified by OVA can target lung cancer in nude mice to elicit anti-cancer effect.