【摘要】 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。更多还原

【Abstract】 To study the specific immune responses induced by Mycobacterium tuberculosis H37Ra and its protective efficacy against tuberculosis in mice.C57BL/6 mice were randomly divided into three groups and immunized by H37Ra,BCG and normal saline(NS) respectively.At 8 weeks after immunization,some mice were sacrificed,and the splenic lymphocytes were cultured with PPD in vitro.Stimulation index(SI) was detected by MTT method,and the IFN-γ and IL-2 levels in the culture supernatant were determined by ELISA.The vaccinated C57BL/6 mice were challenged via intra-peritoneal route with MTB H37Rv strain.Four weeks later,the lung of mice were isolated,dissociated and suitable dilutions of the homogenates were plated on Lowenstein-Jensen culture.The numbers of CFU were counted 21 days after incubation.The lung was obtained from each mouse and stored in 10% formalin saline immediately.Tissues were embedded in paraffin,sectioned and stained with hematoxylin and eosin,and the lung histopathological changes were observed by microscopy.It was found that SI,IFN-γ and IL-2 levels of mice immunized by H37Ra and BCG were significantly higher than those by NS.Compared with NS group,the mean numbers of viable bacteria in the lungs of H37Ra group reduced to 0.95log10 CFU(P<0.05).There was no difference between H37Ra and BCG groups.Histopathology of the lungs showed that the H37Ra group induced the higher protective efficacy against tuberculosis.It is concluded from the above observations that H37Ra can induce specific cellular immune response and protective immunity against the challenge with MTB H37Rv strain.H37Ra may be used as a candidate for development of new tuberculosis vaccine.更多还原