新CpG寡聚脱氧核苷酸体内抗肿瘤与增强免疫活性研究

Anti-neoplasm and immuno-modification effect of novel CpG oligodeoxynucleotides in mice

目的:探讨新设计CpG寡聚脱氧核苷酸(ODN)在小鼠体内的抗肿瘤作用及其对荷瘤小鼠免疫功能的影响。方法:建立C57BL/6小鼠腹腔、皮下荷黑素瘤肿瘤模型,腹腔注射CpGODN,观察荷瘤鼠生存时间、肿瘤生长曲线,计算抑瘤率。用酶联免疫吸附试验(ELISA)检测小鼠血清中白细胞介素(IL)12和免疫球蛋白E(IgE)含量;3H-TDR掺入法检测脾脏B细胞、T细胞增殖活性;51Cr释放法检测NK细胞杀伤活性;中性红法检测腹腔巨噬细胞吞噬功能。结果:CpG10,CpG11能明显延长腹腔接种肿瘤小鼠的生存时间,与阳性对照CPG1826相比P<0.01;二者平均抑瘤率(皮下荷瘤鼠)分别为(55.2±2.3)%与(40.7±1.7)%,显著高于CpG1826[抑瘤率(17.8±7.6)%](P<0.05,P<0.01)。CpG10/CpG11可促使荷瘤小鼠血清IL-12含量显著升高(P<0.01),IgE含量显著下降(P<0.01);明显刺激B细胞、T细胞增殖能力以及NK细胞的杀伤活性(P<0.01),对腹腔巨噬细胞的吞噬功能有显著提高(P<0.01)。CpGl0免疫增强活性较CPGl826更强(P<0.05)。结论:CpGODN能激活荷瘤鼠抗肿瘤免疫反应,从而抑制小鼠黑素瘤的生长,新结构寡核苷酸的CpG10呈现优于阳性对照的良好抗肿瘤免疫效应。

Objective ：To investigate the therapeutic and immunologic effects of novel CpG oligodeoxynucleotides on murine melanoma. Methods： Melanoma models were established by peritumoral or subcutaneous inoculation of B16 melanoma into C57BL/6 mice. Survival time was observed, and tumor size was measured regularly after peritumoral injection of PBS, CPG1826, CpG10, and CpGll. Serum levels of interleukin （IL）-12 and IgE were measured by enzyme-linked immunosorbent assay. Proliferation of mouse B cells and T cells was determined by [^3H] thymidine incorporation assay. The NK cytotoxicity of splenocyte was detected with 4-h ^51Cr-release assay. The phagocytic ability of peritoneal macrophage was examined with neutral red chromometry. Results：All CpG ODNs could significantly prolong survival time of mice with B16 melanoma as compared with the PBS treatment （P 〈0.01 ）, especially the CpG-10 group （P 〈0.01 ）. In addition, both CpG10 and CpG11 groups showed more effective as compared wtih CpG 1826 （P 〈 0.01 ）. CpG ODN1826 inhibited the tumor growth by 17.8 % ,while CpG10 and CpG11 were 55.2 % and 40.7 % on day 20, respectively. In tumor-bearing mice, proliferation of B ceils and T cells, NK cytotoxicity of splenocytes and phagocytic ability of peritoneal macrophage were lower than in normal mice （P 〈 0.05 ）. Above immune activities in CpG ODN- treated tumor-beating mice dramatically increased compared with the PBS-treated ones （P 〈0. O1 ）, and their increase in CpG10 group was more significant than in CPG1826 group （P 〈 0.05 ）. Conclusion：The present study suggests that CpG ODN activates the host anti-tumor immune response to inhibit the growth of melanoma in mice. The novel CpGIO presents potent activity.