卡介苗感染人B细胞诱导细胞凋亡

BCG Infection to Human B Cells Induce Cell Apoptosis

目的探究卡介苗(BCG)是否能感染人B细胞及观察感染后对细胞的影响。方法人B细胞系Raji细胞与BCG共培养,4、12和24h后分别用共聚焦及透射电镜观察Raji细胞对BCG的结合和摄取情况,用CCK-8法检测细胞毒性,流式AnnexinⅤ-PI双标法检测细胞凋亡和坏死情况。结果培养4、12和24h后,感染了BCG的细胞比例分别为12.4%±2.0%,23.8%±5.1%,25.2%±4.8%。BCG感染可引起细胞毒性,4h后Raji细胞存活率为75.5%±8.8%,12h后细胞存活率降至51.0%±5.3%,24h后细胞存活率仅为21.6%±4.2%,而感染灭活BCG的细胞存活率均在95%以上。进一步用流式检测凋亡坏死发现,与未感染细胞相比,Raji细胞感染BCG后凋亡,坏死均有所增加,以凋亡增加为主。结论 BCG可以感染人B细胞并诱导细胞凋亡。

Objective To explore whether Bacillus Calmette - Gu6rin （BCG） can infect human B ceils and observe the effects of the infection on B cells. Methods Human B cell line Raji cells were incubated with BCG. After incubation for 4h, 12h and 24h, the di- rect interaction of Raji cells with BCG was observed under confocal microscopy and transmission electronic microscopy. Cytotoxity was de- tected by cell counting kit （CCK -8）. Cell apoptosis and necrosis were assayed by flow cytometry. Results After 4h, 12h and 24h of incubation, the percentage of Raji cells that were infected by BCG was 12.4% ± 2.0% , 23.8% ± 5.1% , 25.2% ± 4.8% , respectively. Live BCG infection induced cytotoxieity. The cell survival rates at 4h, 12h, 24h were 75.5% ± 8.8% , 51.0% ± 5.3% , 21.6% ± 4.2% respectively, while the cells infected with inactivated BCG showed a high survival rate of 95% at any time. Further analysis by flow cytometry showed that cell apoptosis and necrosis, predominantly cell apoptosis of Raji cells were increased by BCG infection. Conclusion BCG can infect human B cells and induce cell apoptosis.