College of Pharmacy, Sahmyook University, Seoul, Republic of Korea.
BMC Med. 2012 Jul 12;10:72. doi: 10.1186/1741-7015-10-72.
Probiotic lactic acid bacteria (LAB) support a functional and balanced immune system, and contribute to immune modulatory effects in combatting microbial pathogens, including viruses. Most cervical cancers are associated with anogenital region infection with high-risk (HR) human papillomavirus (HPV). In this study, we analyzed the antiviral activity of Bifidobacterium adolescentis SPM1005-A in the SiHa cervical cancer cell line expressing HPV type 16.
We assessed the cellular toxicity of B. adolescentis SPM1005-A in SiHa cells by the Trypan blue dye exclusion assay. Cells (3.6 × 105) in culture plates with or without B. adolescentis SPM1005-A in the same type of medium, were incubated with HPV type 16 at a concentration of 5.1 × 107 cfu/ml. For antiviral analysis, we performed quantitative real-time PCR (qRT-PCR) for E6 and E7 oncogene expressions and observed protein levels by immunoblotting.
The qRT-PCR results showed that E6 and E7 mRNA levels decreased simultaneously. Western blot analysis revealed that the E6 protein expression slightly decreased after 24 and 48 h, but the level of E7 protein expression appear unaffected compared with that in the control. Decreased HPV16 E6 and E7 mRNA transcript and protein levels were not associated with cell morphology or significant cytotoxic effects.
This study showed that B. adolescentis SPM1005-A had antiviral activity through suppression E6 and E7 oncogene expression. The results suggest that B. adolescentis SPM1005-A could be potential applications of HPV-associated cervical cancer prevention.
益生菌乳杆菌（LAB）支持功能和平衡的免疫系统，并有助于对抗微生物病原体（包括病毒）的免疫调节作用。大多数宫颈癌与高危（HR）人乳头瘤病毒（HPV）的肛门生殖器区域感染有关。在这项研究中，我们分析了双歧杆菌 SPM1005-A 在表达 HPV 型 16 的 SiHa 宫颈癌细胞系中的抗病毒活性。
我们通过台盼蓝排斥试验评估双歧杆菌 SPM1005-A 在 SiHa 细胞中的细胞毒性。在含有或不含双歧杆菌 SPM1005-A 的相同培养基的培养板中培养 3.6×105 个细胞，并以 5.1×107 cfu/ml 的浓度与 HPV 型 16 孵育。为了进行抗病毒分析，我们进行了 E6 和 E7 癌基因表达的定量实时 PCR（qRT-PCR），并通过免疫印迹观察蛋白水平。
qRT-PCR 结果表明 E6 和 E7 mRNA 水平同时降低。Western blot 分析显示，E6 蛋白表达在 24 和 48 小时后略有下降，但与对照相比，E7 蛋白表达水平似乎不受影响。HPV16 E6 和 E7 mRNA 转录本和蛋白水平的降低与细胞形态或明显的细胞毒性作用无关。
本研究表明双歧杆菌 SPM1005-A 通过抑制 E6 和 E7 癌基因表达具有抗病毒活性。结果表明，双歧杆菌 SPM1005-A 可能有预防 HPV 相关宫颈癌的潜在应用。
