结肠癌细胞裂解物纳米疫苗的抗肿瘤作用研究

Anti-tumor effect of colon cancer cell lysate nano vaccine

目的深入研究结肠癌肿瘤裂解物纳米疫苗的抗肿瘤作用。方法制备纳米化胞嘧啶鸟嘌呤二核苷酸(Cytosine guanine dinucleotide,CPG)佐剂并与结肠癌细胞系(MC38)细胞裂解物(lysate)组成纳米疫苗。体外培养小鼠骨髓来源的树突状细胞(BMDC),分4组进行BMDC的激活实验,分别为PBS组、空纳米颗粒(NP)组、溶解态CPG组和负载CPG的纳米颗粒(CNP)组。建立接种MC38肿瘤细胞的C57BL/6结肠癌荷瘤小鼠模型,肿瘤体积增至50 mm^(3)时分为4个免疫组,即PBS组、MC38细胞裂解物(lysate)组、CNP组和MC38细胞裂解物辅以CNP而成的疫苗(vaccine)组。每隔7 d进行皮下免疫,共免疫3次。最后一次免疫3 d后检测小鼠外周血、脾脏、腹股沟淋巴结T淋巴细胞比例及血清TNF-α、IFN-γ含量。结果经CNP处理的BMDC成熟比例提高(P<0.01)且分泌大量细胞因子(P<0.0001),MC38肿瘤裂解物纳米疫苗免疫荷瘤小鼠后肿瘤体积明显小于其他组(P<0.0001),同时外周血T淋巴细胞、脾脏T淋巴细胞、淋巴结T淋巴细胞比例明显提高(P<0.05),血清中细胞因子含量亦明显增加(P<0.05)。结论MC38肿瘤裂解物纳米疫苗可以有效激活树突状细胞(DC),诱导肿瘤特异性细胞免疫应答,发挥显著的抗肿瘤作用。

Objective To further study the anti-tumor effect of colon cancer tumor lysate-based nano vaccine.Methods The nano cytosine guanine dinucleotide(CPG)adjuvant was prepared and mixed with colon cancer cell line(MC38)cell lysate to form nano vaccine.Dendritic cells derived from mouse bone marrow(BMDC)were cultured in vitro and divided into four groups:PBS group,Nanoparticles(NP)group,CPG group and nanoparticles encapsulated CPG(CNP)group.Establish C57BL/6 mice tumor model inoculated with MC38 colon tumor cells.After inoculation,when tumor volume reached 50 mm^(3),they were divided into four immune groups:PBS group,MC38 tumor lysate(lysate)group,CNP group,vaccine made of MC38 cell lysate with CNP(vaccine)group.Subcutaneous immunization was carried out every 7 days for 3 times.The proportion of T lymphocytes in peripheral blood,spleen and inguinal lymph nodes and the contents of TNF-αand IFN-γin serum were detected in 3 days after the last immunization.Results The mature ratio(P<0.01)of BMDC treated with CNP increased(P<0.01)and secreted a large number of cytokines(P<0.0001).The tumor volumes were significantly smaller in mice immunized with nano vaccine than those of other groups(P<0.0001).The proportion of peripheral blood T lymphocytes,spleen T lymphocytes and lymph node T lymphocytes increased significantly(P<0.05),and the cytokines were increased significantly in serum(P<0.05).Conclusion MC38 tumor lysate-based nano vaccine can effectively activate dendritic cells and induce tumor specific cellular immune response,which leads to remarkable anti-tumor immune effects.