DNA疫苗初免-BCG加强免疫法提高小鼠抗结核分枝杆菌感染效率的研究  

DNA Prime-BCG Boost Vaccination Strategy Improved The Protective Efficacy Against M. tuberculosis H37Rv in Mice

作　　者：李敏[1] 余大海[1] 蔡宏[1] 

机构地区：[1]北京大学蛋白质工程与植物基因工程国家重点实验室,北京100871

出　　处：《生物化学与生物物理进展》2007年第7期746-753,共8页Progress In Biochemistry and Biophysics

基　　金：国家高技术研究发展计划资助项目(863)(2002AA206411).~~

摘　　要：对结核分枝杆菌DNA四价疫苗(编码Ag85B,MPT64,MPT70和TB10.4抗原)初发免疫、卡介苗(BCG)加强免疫后小鼠产生免疫应答的能力和抗结核杆菌感染效率进行了分析.攻毒后细菌计数结果显示,DNA初免、BCG加强组肺脏和脾脏载菌数的对数值比阴性对照组下降1.0～1.3(P<0.01),且显著低于DNA四价苗和BCG组(P<0.05).3次免疫后,BCG加强组外周血中CD4+和CD8+T淋巴细胞显著增多(P<0.05);经4种抗原分别刺激,BCG加强组脾细胞产生的抗原特异性IFN-γ和IL-2水平显著高于其他免疫组,其中Ag85B抗原诱导产生的IFN-γ浓度为1250ng/L,IL-2浓度为230ng/L,分别是DNA四价苗组的1.6,1.7倍(P<0.05),是BCG组PPD诱导产生相应细胞因子浓度的2.6倍和2.2倍(P<0.05);此外,BCG加强组肺脏中分泌穿孔素的淋巴细胞数量也显著增加(P<0.05).结果表明,DNA初发免疫、BCG加强免疫法能显著提高小鼠CD4+,CD8+T细胞介导的免疫应答,增强小鼠抗结核杆菌感染能力,是提高结核病疫苗免疫效果的新途径.The immunogenicity and protective efficacy of combined DNA priming, Bacillus Calmeette Guerin （BCG） boosting vaccination in mice were examined. Following intravenous challenge with virulent M. tuberculosis H37Rv, the BCG boost approach resulted in significant protection in both lungs （1.3, P 〈 0.01） and spleens （l.1, P 〈 0.01） compared with the saline control. In addition, this approach also have much better protection than that vaccination with combined DNA or BCG alone （P 〈 0.05）. The elevated CD4^＋ and CD8^＋ T cells percentage （P 〈 0.05） in PBMC and higher IFN-γ concentration （1250 ng/L, P 〈 0.01）, IL-2 concentration （230 ng/L, P 〈 0.05） stimulated by Ag85B protein in spleen cells supernatant in BCG boosted mice 21 days after third vaccination, indicating that the DNA prime-BCG boost strategy significantly enhanced the Thl type cell response, which is correlated with the protective efficacy against tuberculosis. Furthermore, immuno-histochemistry assay showed that there were more Perforin expression cells, secreted mainly by CD8^＋ T cells, in the lung tissue of the mice primed with DNA prior to BCG. Taken together, the heterogonous boost combination provided superior protection by stronger CD4^＋ （Th1） and CDS＋T cell mediated immune response, which suggested that it will be a promising regimen for MTB vaccine development.

关 键 词：结核分枝杆菌 DNA疫苗 BCG疫苗 免疫应答 TH1型细胞因子 保护效率 

分 类 号：S855.2[农业科学—临床兽医学]