GM-CSF增强胰腺癌MUC1-VNTR核酸疫苗免疫效果的研究

Immune response enhanced by GM-CSF in mice immunized with MUC1-VNTR DNA vaccine for pancreatic carcinoma W

目的研究 GM-CSF 作为免疫佐剂对胰腺癌 MUC1-VNTR 核酸疫苗免疫效果的增强作用。方法 45只 C57BL/6小鼠随机分3组,在胫前肌注射100μg/100μl质粒 DNA 生理盐水溶液(VG 组接种 pcDNA3.1-VNTR/Myc-his(+)A 质粒联用 rmGM-CSF,V 组单纯接种 pcDNA3.1-VNTR/Myc-his(+)A 质粒,G 组单纯接种 rmGM-CSF)进行免疫接种。4周后加强免疫1次,6周后取血清 ELISA 法测抗体,取脾细胞悬液体外以 VNTR 合成肽特异刺激,6d 后进行杀伤试验。结果VG 组小鼠脾细胞 CTL 的特异性杀伤率显著高于 V 组(P<0.01)和 G 组(P<0.01),表明 GM-CSF增强了疫苗所诱发的 CTL 应答。而 CTL 对未经 VNTR 合成肽孵育的靶细胞 EL4-VNTR^-杀伤较低(P<0.01),VU 3C6可抑制 CTL 对经 VNTR 合成肽孵育的靶细胞 EL4-VNTR^+的杀伤活性(P<0.01),表明具有 VG 组诱生的 CTL 应答依然保持 VNTR 特异性。VG 组小鼠血清抗 VNTR 抗体等效浓度(3119.0±110.6)μg/ml 高于Ⅴ组(2323.5±238.3)μg/ml 和 G 组(2023.9±169.0)μg/ml,差别极为显著(P<0.01)。结论 GM-CSF 可增强自行构建的胰腺癌 MUCl-VNTR 核酸疫苗所诱生的 VNTR 特异的 CTL 应答和抗体应答。

Objective To study both CTL responses and antibody responses specific to VNTR enhanced by granulocyte macrophage colony-stimulating factor in mice immunized with MUC1-VNRT DNA vaccine. Methods C57BL/6 mice were randomly given the transmuscular immunization into the anterior tihialis muscle with 100 μg plasmid DNA encoding VNTR pcDND3.1-VNTR/Myc-his（＋）A and 50 ng rmGM-CSF （VG group, n=15）. The mice inoculated with either pcDNa3.1-VNTR/Mychis（＋）A vector （V goup, n=15） or rmGM-CSF （G group, n=15） were employed to serve as the controls. Four weeks alter, all the mice were injected again with the same solution as before. Another 2 weeks later, the blood samples were collected for the ELISA assay of anti-VNTR antibodies and spleen cells were obtained and stimulated by the synthesized VNTR polypeptide in vitro for cytotoxic activity analysis 6 d later. Results The specific CTL lyses against VNTR polypeptide induced in the VG group was significantly higher than that in V group and G group （P〈0. 01）, indicating that rmGM-CSF can enhance the CTL response induced by the vaccine. However, CTL lyses much more VNTR-positive EIA than VNTR-negative EL4 （P〈0. 01）, while the anti-VNTR antibody VIA 3C6 significantly restrained such activity （P〈0.01）. This indicates that the CTL lyses was specific on VNTR.The equivalent concentration of specific antibody against VNTR was markedly higher in VG group than in V group and G group （P〈0.01）, which means that rmGM-CSF could enhance the antibody response induced by the vaccine. Conclusions The VNTR specific CTL response and antibody response induced in mice immunized with MUC1-VNTR DNA vaccine can be significantly enhanced by rmGM-CSF.