结核分枝杆菌Ag85B和MPT64基因疫苗的免疫原性比较

Comparison of immunogenicity of DNA vaccine encoding Mycobacterium tuberculosis Ag85B and MPT64

目的 :研究并比较结核分枝杆菌 (H37Rv)Ag85B和MPT6 4DNA疫苗免疫学特性 .方法 :雌性C5 7/6小鼠 2 0只 ,随机分为 4组 .A组 (PBS)、B组 (pcDNA3.1)、C组 (pcDNA/Ag85B)、D组 (pcDNA/MPT6 4 ) ;分别于胫前肌注射 7.5g·L-1利多卡因和质粒混合物 (1∶4 ,5 0 μL) ,含质粒 70 μg/次 ,末次免疫后 4wk收集血清测总IgG ,分离脾淋巴细胞用PPD刺激后分别作脾淋巴细胞增殖实验 (MTT法 )和测上清中IFN γ 含量 .结果 :Ag85B和MPT6 4基因疫苗均能诱导小鼠产生特异性的IgG(平均滴度为 1∶80和 1∶6 0 )、脾淋巴细胞增殖 (比值≥ 2 )和IFN γ 的分泌 (Ag85B 176 2ng·L-1;MPT6 4 15 2 3ng·L-1) ,其淋巴细胞增殖和IFN γ 的分泌水平 ,Ag85B优于MPT6 4 .结论 :Ag85B和MPT6 4DNA疫苗均能诱导小鼠产生特异性细胞免疫和体液免疫 .

AIM: To compare the immunogenicity of DNA vaccine encoding Mycobacterium tuberculosis Ag85B and MPT64. METHODS: C57/6 mice were intramuscularly immunized with the saline (A), plasmid vector (B), pcDNA/ Ag85B( C ) and pcDNA/MPT64(D) DNA vaccine three times, at 2 weeks’ intervals and sacrificed at the 4th week after the final immunization. The specific antibody levels were determined by ELISA and spleen lymphocyte proliferation and secreted levels of IFN γ in response to antigen restimulation were measured respectively by MTT and ELISA method in vaccinated mice. RESULTS: The Ag85B and MPT64 DNA vaccine induced specific antibodies against PPD were determined(1∶80,1∶60)and antigen specific lymphocyte proliferation and the increased IFN γ(Ag85B 1762 ng·L -1 ;MPT64 1523 ng·L -1 ) were justified in immunized mice. CONCLUSION: Ag85B and MPT64 DNA vaccine can induce specific cellular and humoral immunity in immunized mice.