Nukuzuma Souichi, Onogi Hiroshi, Suzuki Tetsuro
Research Laboratory, KinoPharma Inc., Kyoto, Japan.
Department of Microbiology and Immunology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan.
Microbiol Immunol. 2024 May;68(5):179-184. doi: 10.1111/1348-0421.13124. Epub 2024 Mar 3.
BK polyomavirus (BKPyV) was the first human polyomavirus to be isolated from an immunosuppressed kidney transplant recipient in 1971. BKPyV reactivation causes BKPyV-associated nephropathy and hemorrhagic cystitis. However, the mechanisms underlying BKPyV replication remain unclear. In the present study, we performed the long-term cultivation of COS-7 cells transfected with archetype KOM-5 DNA, which were designated as COS-BK cells. BKPyV derived from COS-BK cells was characterized by analyzing the amount of the virus based on hemagglutination, viral replication, and the production of viral protein 1 (VP1). Immunostaining showed that VP1-positive cells accounted for a small percentage of COS-BK cells. The nucleotide sequences encompassing the origin of the DNA replication of BKPyV derived from COS-BK cells were generated from KOM-5 by the deletion of an 8-bp sequence, which did not involve T antigen binding sites. BKPyV replicated most efficiently in COS-BK cells in DMEM containing 2% fetal bovine serum. These results indicate that COS-BK cells are a suitable culture system for studying the persistent infection of archetype BKPyV.
BK多瘤病毒（BKPyV）是1971年从一名免疫抑制的肾移植受者中分离出的首例人类多瘤病毒。BKPyV再激活会导致BKPyV相关性肾病和出血性膀胱炎。然而，BKPyV复制的潜在机制仍不清楚。在本研究中，我们对转染了原型KOM-5 DNA的COS-7细胞进行了长期培养，这些细胞被命名为COS-BK细胞。通过基于血凝、病毒复制和病毒蛋白1（VP1）产生来分析病毒量，对源自COS-BK细胞的BKPyV进行了表征。免疫染色显示，VP1阳性细胞在COS-BK细胞中占比很小。通过缺失一个8碱基对序列（该序列不涉及T抗原结合位点）从KOM-5生成了包含源自COS-BK细胞的BKPyV DNA复制起点的核苷酸序列。BKPyV在含有2%胎牛血清的DMEM中在COS-BK细胞中复制效率最高。这些结果表明，COS-BK细胞是研究原型BKPyV持续感染的合适培养系统。
