结核菌H37Ra在小鼠体内诱导的免疫应答

目的检测结核菌H37Ra免疫小鼠后产生的特异性细胞免疫和体液免疫应答水平。方法将BALB/c小鼠随机分为H37Ra组、BCG组和生理盐水(NS)组,分别进行免疫,免疫8周后处死小鼠,分离血清,ELISA间接法测定血清特异性抗PPDIgG抗体的水平,流式细胞分析仪检测脾脏T淋巴细胞亚群的变化。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,ELISA法检测培养上清液中IFN-γ和IL-4的水平。结果H37Ra免疫小鼠血清中抗PPDIgG抗体、脾脏CD3+T细胞和CD4+T细胞的百分率、脾淋巴细胞刺激指数、IFN-γ和IL-4水平均显著高于NS对照组,但与BCG组差异无显著意义。各组间脾脏CD8+T细胞、CD4+T/CD8+T比值差异均无显著意义。结论H37Ra免疫小鼠后,可以产生特异性的细胞免疫和体液免疫应答,有望成为结核疫苗的候选抗原。

Immune Response Induced by Mycobacterium tuberculosis H37Ra in Mice

Objective To determine the specific cellular and humoral immune response levels induced by Mycobacterium tuberculosis H37Ra in mice.Methods Divide BALB/c mice into three groups and immunize by H37Ra,BCG and normal saline (NS) respectively.Kill the mice 8 weeks after immunization and determine the specific IgG level against PPD in sera by ELISA,and the T lymphocyte subgroup in spleens by flow cytometry.Culture splenic lymphocytes in vitro,stimulate with PPD and determine the stimulating index by MTT method,and the IFN-γ and IL-4 levels in culture supernatant by ELISA.Results The specific IgG level against PPD in sera,the percentages of CD3+ and CD4+ T lymphocytes in spleen,the stimulating index of splenic lymphocytes as well as IFN-γ and IL-4 levels of mice immunized by H37Ra was significantly higher than those by NS,while showed no significant difference with those by BCG.However,no significant difference was observed in the percentage of CD8+T lymphocytes or the ratio of CD4+T lymphocytes to CD8+T lymphocytes of various groups.Conclusion H37Ra induced specific cellular and humoral immune responses in mice and might be used as a candidate antigen for development of tuberculosis vaccine.