BCG-DNA和BCG-PSN对诱导IFN-γ产生的比较研究

COMPARATIVE STUDY OF BCG-DNA AND BCG-PSN IN INDUCING THE GENERATION OF IFN-γ

目的比较研究卡介菌基因组DNA(genomic DNA from mycobacterium bovis bacillus calmetteguerin,BCG-DNA)和卡介菌多糖核酸(polysaccharide nucleic acid fraction from mycobacterium bovis bacilluscalmette-guerin,BCG-PSN)的免疫调控活性。方法制备高纯度BCG-DNA,小鼠脾细胞和人外周血单个核细胞(human peripheral blood mononuclear cell,hPBMC)分别与BCG-DNA和BCG-PSN共同培养72h,采用酶联免疫吸附方法检测细胞培养上清中干扰素-γ(interferon-γ,IFN-γ)的水平。结果所制备的BCG-DNA纯度较高(DNA95.3%),片断大小均匀一致,集中于200～250bp。BCG-DNA与BCG-PSN均可诱导小鼠脾细胞和hPBMC产生IFN-γ,且当浓度≥10mg/L时,BCG-DNA诱导产生IFN-γ水平显著强于BCG-PSN(P<0.01),IFN-γ水平与BCG-DNA浓度呈正相关。结论 BCG-DNA可显著诱导辅助性T细胞1型细胞因子IFN-γ的产生,其免疫调控活性优于BCG-PSN。

Objective To compare the immunomodulatory property of genomic DNA from mycobacterium bovis bacillus calmette-guerin(BCG-DNA) and that of polysaccharide nucleic acid fraction from mycobacterium bovis bacillus calmette-guerin(BCG-PSN).Methods Highly purified BCG-DNA was isolated.Murine splenocyte or human peripheral blood mononuclear cell(hPBMC) were incubated with BCG-DNA or BCG-PSN for 72 h,interferon-γ(IFN-γ) in cell cultures supernatant was tested by enzyme-linked immunosorbent assay(ELISA).Results BCG-DNA was extracted,the concentration of DNA was 95.3%.Agarose electrophoresis showed that the size of BCG-DNA was 200～250 bp.ELISA test showed that both BCG-DNA and BCG-PSN could activate murine splenocytes and hPBMC,and significantly increase IFN-γ level ( P <0.01). Moreover,BCG-DNA induced higher level of IFN-γ compared to BCG-PSN when the concentration of BCG - DNA≥10 mg / L ( P < 0.01 ),and such effect was dose - dependent. Conclusion Compared with BCG-PSN,BCG-DNA can significantly induce typical T helper cell 1 (Th1) cytokine(IFN-γ) in vitro,and it is a potent Th1 immunoregrlator.