Dou Jun, Tang Quan, Zhao Fengshu, Chu Lili, Chen Junsong, Cao Minggang, Liu Chunsheng, Wang Yongfang, Li Yating, Li Jin Long
Department of Pathogenic Biology and Immunology, Southeast University School of Basic Medical Science, Nanjing, China.
Immunol Invest. 2008;37(2):113-27. doi: 10.1080/08820130701690741.
In this paper, we addressed the immune adjuvant effects of interleukin(IL)-21 on DNA vaccine constructs expressing mycobacterium tuberculosis (TB) Ag85A and compared immune responses induced in mice inoculated DNA vaccine constructs expressing Ag85A and IL-21 with mice inoculated DNA vaccine constructs expressing Ag85A alone or Bacillus Galmette-Guérin(BCG.). In this experiment, the gene of IL-21 was firstly amplified from plasmid pcDNA3.1-mIL21 by PCR and cloned into the plasmid pRSC, forming recombinant plasmid pRSC-IL21. Then, the gene of Ag85A was amplified from the plasmid pIRES-Ag85A by PCR and cloned into the recombinant pRSC-IL21 again, finally forming co-expression DNA vaccine constructs pRSC-IL21-Ag85A. It was identified by the analysis of endonuclease digestion, DNA sequencing, the IL-21 and Ag85A expression in SP2/0 cells. Mice were i.m. immunized with BCG, DNA vaccine constructs pRSC-Ag85A or pRSC-IL21-Ag85A respectively, and the immune responses induced in mice was compared with other vaccines. The results showed that the DNA vaccine constructs pRSC-IL21-Ag85A was successfully constructed since the Ag85A and IL-21 was correctly expressed in SP2/0 cells respectively, and it elicited stronger immune responses in Balb/c mice than that of mice immunized with pRSC-Ag85A and the efficiency was as BCG did. We concluded that the IL-21 was a promising immune adjunctive modality to enhance immunigenicity of DNA vaccine containing Ag85A and the study provided the possibility of further development of immune accessory effect of IL-21 on DNA vaccine against TB.
在本文中，我们探讨了白细胞介素（IL）-21对表达结核分枝杆菌（TB）Ag85A的DNA疫苗构建体的免疫佐剂作用，并比较了接种表达Ag85A和IL-21的DNA疫苗构建体的小鼠与接种仅表达Ag85A的DNA疫苗构建体或卡介苗（BCG）的小鼠所诱导的免疫反应。在本实验中，首先通过PCR从质粒pcDNA3.1-mIL21中扩增IL-21基因，并将其克隆到质粒pRSC中，形成重组质粒pRSC-IL21。然后，通过PCR从质粒pIRES-Ag85A中扩增Ag85A基因，并再次克隆到重组pRSC-IL21中，最终形成共表达DNA疫苗构建体pRSC-IL21-Ag85A。通过内切酶消化分析、DNA测序、SP2/0细胞中IL-21和Ag85A的表达对其进行鉴定。小鼠分别通过肌肉注射用BCG、DNA疫苗构建体pRSC-Ag85A或pRSC-IL21-Ag85A进行免疫，并将小鼠诱导的免疫反应与其他疫苗进行比较。结果表明，DNA疫苗构建体pRSC-IL21-Ag85A成功构建，因为Ag85A和IL-21分别在SP2/0细胞中正确表达，并且它在Balb/c小鼠中引发的免疫反应比用pRSC-Ag85A免疫的小鼠更强，且效果与BCG相当。我们得出结论，IL-21是一种有前景的免疫辅助方式，可增强含Ag85A的DNA疫苗的免疫原性，该研究为进一步开发IL-21对抗结核DNA疫苗的免疫辅助作用提供了可能性。
