Haukland H H, Vonen B, Traavik T
Virological Research Group, Institute of Medical Biology, University of Tromsø, Norway.
Int J Cancer. 1992 Apr 22;51(1):79-83. doi: 10.1002/ijc.2910510116.
Single-cell suspensions of primary rat pancreatic islet cells were infected with BK virus (BKV) prototype (Gardner) and the naturally occurring BKV strain (TU), isolated from human urine. These viral strains have different sequences in their non-coding control regions which contain promoter-enhancer elements and origin of DNA replication. Uninfected cell cultures disintegrated within 3 weeks, while a varying number of virus-infected cultures were immortalized and a majority exhibited focal areas of 2-dimensional growth. A significantly higher proportion of the BKV (TU)- than of the BKV (Gardner)-infected cultures were immortalized. Large tumor (T) antigen expression was evident in virus-infected cultures from day 4 post infection (p.i.), while insulin secretion decreased steadily during the first weeks of culture. Two cell lines were established from BKV (TU)-infected cultures. Line 5A4 was contact-inhibited, growing as a dense monolayer, while 6A3 demonstrated foci of 2-dimensional growth. Both cell lines have retained their morphology and T-antigen expression for approximately 130 passages. At high passages a low level of intracellular insulin, but no secretion into media, was detected. Based on standard biological tests (reduced serum requirements, growth at low cell density, anchorage-independent growth and tumor induction in nude mice) both cell lines have a fully transformed phenotype, but 6A3 appears to be more malignantly transformed. Since both cell lines were established simultaneously from the same primary cells with the same virus batch, they provide an opportunity to study the transforming mechanisms of BKV in a relative context.
将原代大鼠胰岛细胞的单细胞悬液用BK病毒（BKV）原型株（加德纳株）和从人尿中分离出的自然发生的BKV株（TU株）进行感染。这些病毒株在其非编码控制区具有不同序列，该区域包含启动子增强子元件和DNA复制起点。未感染的细胞培养物在3周内解体，而不同数量的病毒感染培养物被永生化，并且大多数表现出二维生长的病灶区域。与BKV（加德纳株）感染的培养物相比，BKV（TU株）感染的培养物中永生化的比例显著更高。从感染后第4天（p.i.）起，病毒感染的培养物中可见大T抗原表达，而在培养的最初几周胰岛素分泌稳步下降。从BKV（TU株）感染的培养物中建立了两个细胞系。5A4细胞系具有接触抑制性，以致密单层生长，而6A3细胞系表现出二维生长的病灶。两个细胞系在大约130代中都保持了其形态和T抗原表达。在高代时，检测到细胞内有低水平的胰岛素，但无胰岛素分泌到培养基中。基于标准生物学测试（降低血清需求、在低细胞密度下生长、不依赖贴壁生长以及在裸鼠中诱导肿瘤），两个细胞系都具有完全转化的表型，但6A3似乎具有更恶性的转化。由于两个细胞系是用同一病毒批次从相同的原代细胞同时建立的，它们提供了一个在相对背景下研究BKV转化机制的机会。
