【摘要】 目的初步研究结核杆菌磷酸烯醇型丙酮酸羧激酶(PEPCK)的免疫作用。方法用敲除pckA基因的卡介苗(BCG△pckA)和野生型卡介苗(BCG-WT)分别感染小鼠,取肺脏进行病理分析;取脾脏用流式细胞仪检测CD4+、CD8+T细胞、CD4+/CD8+,酶联免疫吸附试验检测IL-12;取脾脏进行结核杆菌的培养,比较两组菌落数量。结果BCG△pckA感染的小鼠比BCG-WT感染的小鼠肺脏内产生的结核结节少且不典型,炎性程度低;BCG-WT感染的小鼠脾脏内的CD4+T细胞和CD4+/CD8+及IL-12滴度明显高于BCG△pckA感染的小鼠;BCG△pckA株形成菌落的数量明显低于BCG-WT株形成菌落的数量。结论pckA基因为结核杆菌生长所必需,其编码产物PEPCK能够刺激机体产生免疫反应,可能是一种很好的疫苗候选分子。更多还原

【Abstract】 Objective To research the immune effect of phosphoenolpyruvate carboxykinase(PEPCK) of mycobacterium tuberculosis.Methods Mice were infected with wild type BCG and pckA mutated BCG respectively.The lung histology of infected mice was checked.The number of CD4+ and CD8+ T cells,CD4+/CD8+ were assayed by flow cytometry.Interleukin-12 was detected by ELISA.BCG from spleens of two groups of mice was cultured and the number of CFU was taken count.Results Granulomas in pckA mutated BCG(BCG△pckA) infected mice were fewer and more atypical than those in mice infected with wild type(BCG-WT).The number of CD4+ T cells and the ratio of CD4+/CD8+ from the BCG-WT group were significantly higher than those form BCG△pckA group.The titer of interleukin-12 of BCG-WT infected mice was higher that that of BCG△pckA group.And the number of BCG CFU from BCG-WT group was more than that of BCG△pckA group.Conclusion pckA gene is necessary for the growth of mycobacterium tuberculosis.PEPCK can effectively induce immune responses and can be a good candidate for vaccine.更多还原