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为研究结核菌H37Ra免疫小鼠后产生的特异性免疫应答以及保护效果,将C57BL/6小鼠随机分为H37Ra组、BCG组和生理盐水(NS)组,免疫8周后处死部分小鼠,取脾淋巴细胞经体外培养、PPD刺激后,MTT法检测脾淋巴细胞的刺激指数(SI),ELISA法检测培养上清液中IFN-γ和IL-2水平。另一部分免疫小鼠用结核分枝杆菌(Mycobacterium tubercu-losis,MTB)毒株H37Rv经腹腔感染,4周后处死,取稀释的小鼠肺脏匀浆接种于改良罗氏培养基,培养21 d后计数肺组织中的MTB菌落数,同时对小鼠部分肺组织作病理切片,HE染色观察组织病变程度。结果显示,H37Ra和BCG免疫小鼠脾淋巴细胞SI、IFN-γ和IL-2水平均显著高于NS对照组(P<0.05)。感染4周后,H37Ra组小鼠肺组织荷菌量比NS对照组下降了0.95log10CFU(P<0.05),肺组织病理变化明显减轻。提示H37Ra免疫小鼠后可以诱导产生特异性细胞免疫应答,能够抵抗MTB毒株H37Rv的攻击,可作为新型结核疫苗的候选组分。
C57BL / 6 mice were randomly divided into H37Ra group, BCG group and NS group. The mice were killed 8 weeks after immunization, Splenic lymphocytes were cultured in vitro and stimulated with PPD. The stimulation index (SI) of splenic lymphocytes was measured by MTT assay. The levels of IFN-γ and IL-2 in culture supernatants were detected by ELISA. Another part of the mice were immunized intraperitoneally with Mycobacterium tubercu-losis (H37Rv) and killed after 4 weeks. The diluted mouse lung homogenates were inoculated into modified Roche medium and counted after 21 days The number of MTB colonies in lung tissue, while some of the lung tissue of mice for pathological sections, HE staining observed tissue lesions. The results showed that the levels of SI, IFN-γ and IL-2 in splenic lymphocytes of H37Ra and BCG immunized mice were significantly higher than those in NS control group (P <0.05). After 4 weeks of infection, the mice in the H37Ra group had a 0.95log10CFU (P <0.05) decrease in the bacterial load in the lungs compared with the NS control group, and the pathological changes in the lung tissue were significantly reduced. It is suggested that H37Ra can induce specific cellular immune response and can resist the challenge of MTB strain H37Rv, which can be used as a candidate component of new tuberculosis vaccine.