Department of Nephrology, Chang Gung Memorial Hospital, Taipei, Taiwan.
Transplantation. 2010 Feb 15;89(3):299-306. doi: 10.1097/TP.0b013e3181c9b51c.
The effect of cyclosporine A (CsA) on polyomavirus BK virus (BKV) replication remains unclear. The aim of this in vitro study was to investigate the effect of CsA on BKV replication in human uroepithelial cells.
After infection of a human renal proximal tubular cell line, HK-2 with BKV, BKV viral load in the presence of CsA was assessed by real-time polymerase chain reaction. The BKV large T-antigen (LTag) expression was measured by Western blot analysis. The BKV early promoter activity was determined by measuring luciferase activity of the BKV noncoding control region luciferase reporter. The BKV LTag expression in a human bladder carcinoma cell line, T24, was assessed by immunofluorescence.
The results demonstrated that the increased levels of BKV LTag and viral protein 1 transcripts measured by real-time polymerase chain reaction were suppressed by CsA in a dose-dependent manner (0.5-4 microg/mL). Western blot analysis also showed that CsA inhibited BKV LTag expression. In addition, the activity of the BKV early promoter, which was enhanced by BKV LTag overexpression, was abrogated by CsA. Finally, the suppressive effect of CsA on BKV replication was also shown in T24 cells as CsA reduced immunofluorescent staining of BKV LTag in these cells.
This in vitro study indicates that CsA suppresses BKV replication in human proximal renal tubular cells and uroepithelial cells of the urinary bladder and inhibits the BKV-LTag-regulated increase in early promoter activity.
环孢素 A（CsA）对多瘤病毒 BK 病毒（BKV）复制的影响尚不清楚。本体外研究旨在探讨 CsA 对人尿路上皮细胞中 BKV 复制的影响。
在人肾近端肾小管细胞系 HK-2 感染 BKV 后，通过实时聚合酶链反应评估 CsA 存在时的 BKV 病毒载量。通过 Western blot 分析测量 BKV 大 T 抗原（LTag）的表达。通过测量 BKV 非编码控制区荧光素酶报告基因的荧光素酶活性来确定 BKV 早期启动子活性。通过免疫荧光法评估人膀胱癌细胞系 T24 中的 BKV LTag 表达。
结果表明，实时聚合酶链反应测量的 BKV LTag 和病毒蛋白 1 转录物的水平增加被 CsA 以剂量依赖性方式抑制（0.5-4μg/ml）。Western blot 分析还表明 CsA 抑制 BKV LTag 表达。此外，BKV LTag 过表达增强的 BKV 早期启动子活性被 CsA 阻断。最后，CsA 对 BKV 复制的抑制作用也在 T24 细胞中得到证实，因为 CsA 减少了这些细胞中 BKV LTag 的免疫荧光染色。
本体外研究表明，CsA 抑制人近端肾小管细胞和膀胱尿路上皮细胞中的 BKV 复制，并抑制 BKV-LTag 调节的早期启动子活性增加。
