CpG ODN加强树突状细胞疫苗抗Lewis肺癌的研究

Studies on the enhancement of DC vaccine to mouse Lewis lung cancer by CpG oligonucleotides

目的 探讨CpGODN对树突状细胞 (DC)疫苗抗肿瘤作用的影响。方法 应用ODN182 6作为DC的成熟刺激信号 ,体外控制DC充分成熟 ,以混合或融合的方式将肿瘤抗原负载于DC制备DC疫苗。以特异性杀伤细胞活性和淋巴细胞增殖反应测定疫苗的体外免疫活性 ,并将疫苗经小鼠腹腔注射 ,观察治疗和预防实验肿瘤的生长情况。结果 经ODN 182 6刺激后的DC细胞形态呈成熟状态 ,流式细胞仪分析检测刺激前后DC细胞表面分子CD4 0的表达分别为 11和 2 4 (MFI) ,CD86的表达分别为 33和 75 (MFI) ,刺激后的DC培养上清中IL 12的分泌水平为刺激前的 10倍。刺激后DC融合疫苗组CTL活性、T淋巴细胞增殖活性及体内Lewis肺癌移植瘤的抑瘤率均明显高于未刺激的DC融合组 (P <0 .0 5 )。结论 CpGODN能通过诱导DC成熟 ,增强DC疫苗的抗肿瘤作用 ,有效诱导机体产生特异的抗肿瘤反应。未成熟的DC可通过与肿瘤细胞混合的方式 ,获得较好的抗原捕获效果 ,产生一定的抗肿瘤效应 ,而对于刺激成熟的DC则需通过融合手段负载抗原 ,达到有效的抗肿瘤活性。

Objective To investigate whether CpG ODN can affect the antitumor responses of DC tumor cell vaccine against Lewis lung cancer. Methods CpG oligonucleotides 1826 (ODN 1826) were used to promote maturation of DCs in vitro. By fusing DCs with Lewis lung carcinoma L3 8 cells, DC based tumor cell vaccines were developed. To determine the immune responses to the vaccines, T cell proliferation and cytotoxicity were done in vitro. Theraputic and prophylactic immunization with DC vaccines were performed in C57BL/6 mice bearing Lewis lung carcinoma. Results Bone marrow cells cultured in the presence of GM CSF and IL 4 plus additional ODN 1862 appeared typical morphology of DCs. FACS analyses showed that the mean fluorescence index (MFI) of CD40 expression of DCs stimulated with and without CpG ODN was 24 and 11, respectively, and that of CD86 expression was 75 and 33, respectively. IL 12 secreted by DCs cultured with ODN 1826 was 10 fold as high as that without ODN 1826. Significant T cell proliferation and T cell mediated cytotoxicity against L3 8 was induced in vitro. Marked inhibition of tumor growth in L3 8 bearing mice was observed upon prophylactic and therapeutic immunizations with the vaccine. Conclusion CpG ODN can enhance the antitumor responses of DC vaccine by promoting DC maturation. [