结核感染小鼠肺部病理变化与T细胞免疫关系的实验研究

Experimental research of the relationship between lung pathological changes and cell immunity of tuberculosis infection

目的探讨结核病小鼠肺部病理变化与T细胞亚群的关系。方法将60只C57BL小鼠随机分为3组,每组20只。结核病模型组小鼠经球后静脉丛注射人型结核分枝杆菌标准毒力珠(H37RV);免疫调节剂组结核病模型小鼠于H37RV感染后第3、10、17天分别肌注22.5μg母牛分枝杆菌菌苗(微卡菌苗);正常对照组小鼠未做处理。感染4周后,留取外周血用流式细胞仪测定T细胞亚群;取肺组织,采用常规苏木精-伊红染色和抗酸染色后病理切片观察病理变化。结果结核病模型组小鼠大部分肺组织实变,多数肺泡腔消失,肺泡隔重度增宽,肺间质内可见大量炎性细胞浸润,浸润细胞以中性粒细胞为主,淋巴细胞较少。残存的肺泡腔中有红细胞、纤维素渗出。肺实变区内分布大量的紫红色结核分枝杆菌,主要存在于单核-巨噬细胞胞质内。外周血T细胞亚群的相对比率明显减少。免疫调节剂组肺组织病变和结核病模型组大致相似,但实变病灶较少,多数肺泡腔存在,肺泡隔内浸润淋巴细胞较多,肺泡腔内有渗出单核-巨噬细胞。肺实变区内结核分枝杆菌明显少于结核病模型组,CD3+与CD4+T细胞比例增加,能显著增加γδT细胞比例。结论微卡菌苗可增强结核病小鼠的免疫功能,使肺实变病灶较少和病灶内结核分枝杆菌明显减少,肺泡腔内单核-巨噬细胞增多,为免疫调节剂辅助治疗结核病提供理论依据。

Objective To investigate the relationship between lung pathological changes and T lymphocyte subsets proportions in murine model of tuberculosis. Methods Sixty C57 BL mouse were randomly divided into three groups：the mice of tuberculosis model group were injected with Mycobacterium tuberculosis （ H37 RV ） , to establish a tuberculosis murine model ; the mice of immunoregulant group were treated the same as the tuberculosis infection group, and injected intramuscularly with 22.5 μg ofMycobacterium vaccae vaccine on the 3rd,the 10th and the 17th day after H37RV infection;and the normal control mice were raised normally. After four weeks of infection, the peripheral blood was taken and the flow cytometry was used to determine the T cell subsets;and the lung tissue wase kept by adopting HE dyeing and acid fast stain. Results The lung tissue of tuberculosis murine model had severity consolidation. The most alveolar space vanished and interalveolar septum became wide, bulk neutrophils but little lympholeukocyte infiltration were found in the lung mesenchyma, and there were red cells and cellulose effusion in relic alveolar space. A lot of prunosus Mycobacterium tuberculosis were found in the intracytoplasm of the monocyte-macrophage in consolidation of lung. And T cell subsets had a lower relative ratio. The immunoregulant group had resemble processes as the tuberculosis murine model, but had less consolidation focus of infection and most existed alveolar space. There were more lympholeukocyte interalveolar septum infiltration and monocyte-macrophage in alveolar space, and less Mycobacterium tuberculosis were found than tuberculosis model group. There was a higher relative ratio of CD3^＋ and CD4^＋ T cell, and γδT cell relative ratio were predominanced raised. Conclusions Vaccae vaccines can strengthen immune function of the tuberculosis mice and increase monocyte-macrophage in alveolar space, reducing the lung consolidation focus of infection and Mycobacterium tuberculosis in focus of infection. These can provide theory according for immunoregulant adjunctive therapy to tuberculosis.