Delli Bovi P, De Simone V, Giordano R, Amati P
J Virol. 1984 Feb;49(2):566-71. doi: 10.1128/JVI.49.2.566-571.1984.
Infection of Friend erythroleukemic (FL) cells by polyomavirus (Py) invariably results in the selection of persistently infected FL-Py cell lines and clones. Anti-Py serum treatment of FL-Py lines and clones leads to the loss of Py genome and consequent cell cure. Conversely, cure has not been obtained in FL-PytsA cell lines (isolated after infection by a Py thermosensitive early mutant) and their derivative clones cultivated for a long time at nonpermissive temperature (39 degrees C), where viral large-T protein is inactive. Rescue of viral particles has always been obtained after shifting cells to 32 degrees C. Integrated viral genomes were detected by blot hybridization in an FL-PytsA clone at 39 degrees C. Long-term observation of FL-Py cell lines and their derivative clones reveals a reciprocal selection mechanism (coevolution) between the viral and the cellular populations, resulting in either a completely virus-free Py-resistant FL cell line (cure) or in a continuously Py-shedding line bearing Py genome variants. Structural analysis of these viral populations has been carried out, and some viral variants have been isolated and characterized. On the basis of the results obtained, the possible mechanisms of Py persistence in FL cells will be discussed.
多瘤病毒（Py）感染弗氏红白血病（FL）细胞总会导致选择出持续感染的FL-Py细胞系和克隆。用抗Py血清处理FL-Py细胞系和克隆会导致Py基因组丢失，从而使细胞治愈。相反，在FL-PytsA细胞系（感染Py温度敏感早期突变体后分离得到）及其在非允许温度（39℃）长期培养的衍生克隆中未实现治愈，在该温度下病毒大T蛋白无活性。将细胞转移至32℃后总能拯救出病毒颗粒。在39℃时通过印迹杂交在一个FL-PytsA克隆中检测到整合的病毒基因组。对FL-Py细胞系及其衍生克隆的长期观察揭示了病毒群体与细胞群体之间的相互选择机制（共同进化），导致要么产生完全无病毒的抗Py FL细胞系（治愈），要么产生携带Py基因组变体的持续释放Py的细胞系。已对这些病毒群体进行了结构分析，并且分离和鉴定了一些病毒变体。基于所获得的结果，将讨论Py在FL细胞中持续存在的可能机制。
