Ag85a-卡介苗重组疫苗对结核病预防及治疗作用的研究

Study on protection against M. tuberculosis of Ag85a-recombinant BCG vaccine

目的评价Ag85a-卡介苗重组疫苗对结核病预防及治疗效果,期望得到对结核病的预防效果强于卡介苗的重组疫苗。方法观察Ag85a-卡介苗重组疫苗对结核分支杆菌感染的预防试验和治疗实验中实验动物半数死亡时间、一定时间内的死亡率、大体病变、T细胞及B细胞免疫功能等指标评价各卡介苗重组疫苗的抗结核作用。结果用Ag85a-卡介苗重组疫苗对结核分支杆菌感染进行预防,Ag85a-卡介苗重组疫苗及卡介苗与生理盐水对照组比都能延长结核分枝杆菌感染小鼠的半数死亡时间,降低2个月内的死亡率。结核分枝杆菌攻击后2个月,处死小鼠时,Ag85a-卡介苗重组疫苗免疫组小鼠脏器与其他各组之间无显著差别。各组小鼠脏器研磨、消化后稀释为不同梯度进行培养Ag85a-卡介苗重组疫苗免疫小鼠肺脏结核分支杆菌生长的最低稀释度主要集中在10-5,肝、脾结核分枝杆菌生长的最低稀释度主要集中在10-4。抗体检测结果及淋巴细胞增殖实验各组间无显著差别。卡介苗重组疫苗对结核病的治疗试验结果中半数死亡时间与2个月内的死亡率反而不如预防的效果,说明卡介苗或卡介苗重组疫苗等活体疫苗作为结核病治疗性疫苗无明显的治疗效果。结论初步实验表明:Ag85a-卡介苗重组疫苗对结核分支杆菌感染的预防作用与卡介苗无显著区别,卡介苗或Ag85a-卡介苗重组疫苗等活体疫苗作为结核病治疗性疫苗无明显的治疗效果。

[Objective] To evaluate the protective effect of Ag85a-recombinant BCG vaccine against M. tuberculosis. [Methods] A series of indexes such as the death time of experimental animal, the death rate during certain period of time, pathological changes, the immune function of T cell and B cell were observed to evaluate the protective effects of Ag85a-rccombinant BCG vaccine against M.tuberculosis. [Results] The preventive experiment of recombinant BCG against M. tuberculosis indicted： Ag85a-recombinant BCG and BCG can extend death time of half mice and reduce death rate in 2 months of those mouse, the protective effect of Ag85a - recombinant BCG has no difference with BCG. The results of pathological changes and organ culture was also the same with other groups. The antibody level of different groups were the same. The mouse lymph-cell stimulation test revealed： all stimulation indexes of different groups, stimulated by different antigen, were not obviously different. The death time of haft mice and death rate in 2 month in the treatment experiment of recombinant BCG were no better than those in pre- ventive experiment. Other indexes such as：＂ the pathological changes, the organ euhure, the antibody level and the mouse lymph-cell stimulation test were all eonsistent with their results in the prevention experiment. [ Conclusion] Ag85a-reeombinant BCG can not improve protection effeet of BCG. Reeombinant BCG or BCG was not suit for the treatment of M. tuberculosis.