结核杆菌DNA疫苗pVS84与pIL2质粒联合免疫的保护效率研究

目的用构建的人hIL-2质粒和结核杆菌DNA疫苗pVS84联合免疫后,对小鼠的细胞因子进行了测定并对抗结核分枝杆菌H37Rv攻击的能力进行了评估。方法将hil-2插入pVAX1,构建了人hIL-2的质粒pIL2。将雌性C57BL/6鼠分成6组,分别用pVS84和pIL2各50μg,pVS84,pVAX1,pIL2S和PBS免疫3次,间隔2周,加强免疫2次。另一组用BCG(105CFU)皮内免疫1次。每组10只鼠在最后一次加强后,取脾培养,检测上清细胞因子。另10只用结核菌H37Rv攻击,2周后取脾、肝和肺培养结核菌并计数。结果pVS84+pIL2联合免疫组的鼠血清hIL-2平均浓度为720.5±114.5pg/ml,显著高于其它组。pVS84+pIL2组、pVS84组的脾细胞培养上清的mIL-2和mIFN-γ平均含量显著高于3个阴性对照组(P<0.001),与BCG免疫组无显著性差异(P>0.05)。pVS84+pIL2组脾、肝和肺的平均结核菌载量分别为12471.4±2269.3,13622.6±2404.0和14742.0±2378.7CFU/g,低于pVS84组和3个阴性对照组相应器官的结核菌载量(P<0.001),与BCG对照组无显著差异。结论pIL2质粒与pVS84联合免疫能够刺激机体产生Th1型免疫应答,抵抗H37Rv攻击的能力与BCG的效果相当。

Protective efficacy of co-immunization of TB DNA vaccine pVS84 and plasmid pIL2 equivalent to that of BCG

To evaluate the ability to produce cytokines in vitro and the protective efficacy of the mice co-immunized by the TB DNA vaccine pVS84 and hIL-2 expressing plasmid pIL2. Plasmid pIL2 was constructed by inserting hil-2 into pVAX1,20 female C57BL/6 mice in 6 groups were immunized with the 50μg pWS84 and 50μg pIL2, 100μg pVS84, pIL2S, pVAX1, PBS and BCG for 3 times with 2 weeks intervals except BCG(one vaccinization only). Sera and supernatants of 10 mice in each group were determined for hIL-2, mIL-2, mIFN-γ, mIL-6 and mIL-10 by sandwich ELISA. The other 10 were challenged with 10 6 CFUs M tuberculosis H37Rv and killed for culturing H37Rv from the spleens, lungs and livers. Results showed that the average concentration of hIL-2 in pVS84 plus pIL2 co-immunized group was 720.5 ±14.5pg/mL, that was significantly higher than these of other 5 groups. The concentrations of mIL-2 and mIFN-γ from pVS84+pIL2, pVS84 immunized mice were 316.5±45.3 and 627.1±105.8pg/mL, 290.0±112.9pg/mL and 501.7±79.4pg/mL, significantly higher than those from the pVAX1, pIL2S, and PBS controls ( P <0.001). The average M tuberculosis loads in the spleens, livers and lungs in the pVS84+pIL2 group were 12471.4±2269.3,13622.6±2404.0 and 14742.0±2378.7 CFU/g respectively, that was significantly lower than those of their counterparts in pVAX1, pIL2S and PBS groups, but there was no significant difference of H37Rv loads between the co-immunized mice and the BCG controls. It is concluded that co-delivery of pVS84 and pIL2 can induce Th1 response and evokes protective immunity to H37Rv challenge in the immunized mice equivalent to BCG vaccination.