母牛分枝杆菌菌苗预防老龄小鼠肺结核的动物实验研究

目的探讨母牛分枝杆菌菌苗对实验性老龄小鼠肺结核的免疫预防作用。方法老龄C57BL/6J小鼠30只,随机法分为3组:即无免疫保护组、母牛分枝杆菌菌苗预防组(微卡组)、卡介苗(BCG)预防组,分别给予生理盐水0.1ml、母牛分枝杆菌菌苗22.5μg、BCG 0.1 mg皮内注射。4周后将浓度为5×10⁵/ml的H37Rv标准菌株0.2ml经小鼠尾静脉给予攻毒。感染6周后处死小鼠,流式细胞仪测定小鼠外周血T淋巴细胞亚群、观察肺脏肺泡巨噬细胞内结核分枝杆菌数、肺脏中活结核分枝杆菌定量培养及肺组织病理学分析。结果微卡组和卡介苗组的CD4T淋巴细胞、CD4/CD8比值分别为(48.81±3.10、3.84±0.37),(48.08±3.72、4.16±0.24)均较无免疫保护组(38.97±3.03、3.25±0.26)显著升高(p<0.01)。而微卡组CD4/CD8比值则低于卡介苗组(p<0.05)。微卡组和卡介苗组的肺脏肺泡巨噬细胞内结核分枝杆菌数、肺脏中活结核分枝杆菌定量培养分别为(2.3±0.5(、1.06±0.25)×10⁵cfu),(2.7±0.6(、1.21±0.37)×10⁵cfu)无免疫保护组(5.4±0.9、(4.07±0.97)×10⁵cfu)减少(p<0.01)。组织病理学显示微卡组和卡介苗组肺脏结核病变以增殖性结核结节为主,无坏死结节;无免疫保护组肺脏则以淋巴细胞结节、坏死结节为主。结论母牛分枝杆菌菌苗可增强CD4T淋巴细胞活性,对实验性老龄小鼠肺结核有较好的预防作用。

Experimental study on prevention effect of aged mice complicated with tuberculosis by mycobacterium vaccae

Objective To explore the protective effect of mycobacterium vaccae to pulmonary tuberculosis of the experimental aged mice. Methods 30 aged C57BL/6J mice were randomly divided into three groups: the non-immunity protective group(group C);the mycobacterium vaccine preventative group(group M),and the Bacillus Calmette-Guerin(BCG)protective group(group B).All the subjects were injected subcutaneously 0.1 ml Physiological saline,22.5 μg mycobacterium vaccine,and 0.1 mg BCG respectively at the 0 week. Four weeks later,0.2 ml standard vaccine of H37Rv with concentration of 5×10⁵/ml was injected through the lateral tail vein to attack the toxin.Six weeks later after the infection,the mice were killed.The Flow Cytometer was used to test the Peripheral blood T lymphocyte sub-groups of the mice and to count the numbers of mycobacterium tuberculosis in the alveolus macrophages,quantitative culture of mycobacterium tuberculosis of lung tissue and the histopathological changes were analyzed. Results the ratio of CD4T lymphocyte and CD4/CD8 were(48.81±3.10、3.84±0.37) and(48.08±3.72、4.16±0.24) respectively and significantly higher than that in group C which is(38.97±3.03、3.25±0.26)(P<0.01).However,the ratio of CD4/CD8 of group M was lower than that in group B(P<0.05).The numbers of mycobacterium tuberculosis in the alveolus macrophages,quantitative culture of mycobacterium tuberculosis of lung tissue were(2.3±0.5、(1.06±0.25)×10⁵cfu) and(2.7±0.6、(1.21±0.37)×10⁵cfu)respectively and decreased significantly than that in group C(5.4±0.9、(4.07±0.97)×10⁵cfu)(P<0.01).The histopathological changes show that the tuberculosis in group M and group B was mainly proliferation without necrosis;the tuberculosis in group C was mainly lymphocyte tuberosity and necrosis. Conclusion Mycobacterium vaccine can enhance the activity of CD4T lymphocyte and can prevent preferably the pulmonary tuberculosis of aged mice.