摘要
目的为了建立对潜伏感染细菌的保护性免疫应答，本研究选择结核分枝杆菌休眠期、对数生长期最重要的保护性抗原HspX、Mpt64的190～198位的氨基酸多肽（CD8^＋T细胞表位）及Ag85B，构建融合蛋白Ag85B-Mpt64 190-198-HspX（AMH），并对其免疫原性进行研究。方法PCR分别扩增Ag85B、Mpt64 190-198-HspX基因，并依次插入pET-28a质粒中，在大肠杆菌BL21中表达纯化AMH蛋白。将该蛋白和佐剂二甲基三十六烷基铵和卡介苗多糖核酸（DDA＋BCG—PSN）混合构建亚单位疫苗，分别于1、4、7周皮下免疫C57BL／6小鼠3次，最后一次免疫5周后检测体液免疫与细胞免疫反应。结果该融合蛋白以包涵体形式能在大肠杆菌中稳定表达，经Ni—NTA层析柱纯化得到纯度较高的蛋白；构建的亚单位疫苗免疫动物能产生针对结核杆菌特定抗原（PPD、Ag85B、Mpt64 190-198和HspX）的特异性的细胞免疫和体液免疫应答，具有较强的免疫原性。结论融合蛋白AMH作为结核亚单位疫苗候选的融合蛋白抗原有必要进一步研究。
Objective To construct protective immunity to Mycobacterium tuberculosis latent infection, a novel fusion protein consisting of HspX, the 190 to 198 peptide of Mpt64 and Ag85B, which were confirmed to be the effective protective antigens mainly expressed in the dormancy and exponential phase of growth, was constructed and its immunogenicity was investigated. Methods Ag85B and Mpt64 190-198-HspX sequences were amplified by PCR and cloned into plasmids pET-28a. The fusion protein, Ag85B- Mpt64 190-198-HspX （AMH） was expressed in E. coli BL21 and purified with Ni-NTA resins. C57BL/6 mice were immunized three times at 2-week intervals subcutaneously with AMH formulated with the adjuvant composed of dimethyl-dioctyldecyl ammonium bromide （DDA） and BCG polysaccharide nucleic acid （BCGPSN）. Humoral and cell-mediated immunity responses were analyzed at five weeks after the last injection. Results AMH was expressed stably in E. coli and could be purified well by Ni-NTA affinity chromatography. C57BL/6 mice immunized with AMH subunit vaccine generated specific cellular and humoral immunologic response to the stimulation of Ag85B, Mpt64 190-198 and HspX. Conclusion It suggested that AMH was a promising candidate antigen of tuberculosis subunit vaccine.
出处
《中华微生物学和免疫学杂志》
CAS
CSCD
北大核心
2009年第2期103-107,共5页
Chinese Journal of Microbiology and Immunology
基金
国家科技部863项目资助（2006AA022420）
