ABSTRACT The NTU-LY-1 cell line is a Lymantria xylina cell line; however, during cell passage, obvious cytopathic effects (CPEs) were observed under light microscopy. Round inclusion body (IB)-like particles and a few irregular larger IB-like particles were found in the cytoplasm of NTU-LY-1 cells. To further investigate the CPEs in NTU-LY-1 cells, reverse transcription–PCR screening of cytoplasmic polyhedrosis virus, infectious flacherie virus and Perina nuda virus (PnV) was performed. The results indicated that NTU-LY-1 cells were persistently infected with PnV from days 1 to 15 of culture. NTU-LY-1 cells were further subjected to Western blotting and indirect immunofluorescence assays to confirm PnV infection. Based on transmission electronic microscopy observations, the CPEs in NTU-LY-1 cells were different from those in the PnV-homologous NTU-Pn-HF cell line (a cell line of P. nuda). Membrane-bound IBs were found in newly seeded NTU-LY-1 cells. Lysed NTU-LY-1 cells formed many microsomes after 15 days of culture, and three different types of IBs could be distinguished among the microsomes, including membrane-bound, fibril-bound and sheath-bound IBs. After 15 days of culture, the cytoplasm of un-lysed NTU-LY-1 cells contained zipper-like arrays of non-membrane-bound virogenic stroma and parallel rows of viral particles that were restricted by two membranes. These viral particles were purified and showed a PnV morphology. This is the first study to show persistent PnV infection in a heterologous cell line. The findings suggest a new strategy for microbial control; moreover, the findings could support the development of a model for membrane-associated replication of positive-sense single-stranded RNA viruses.

中文翻译：

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异源 Lymantria xylina 细胞系 NTU-LY 中的持续性 PnV（Perina nuda 病毒）感染

摘要 NTU-LY-1 细胞系是 Lymantria xylina 细胞系；然而，在细胞传代过程中，在光学显微镜下观察到明显的细胞病变效应（CPE）。在NTU-LY-1细胞的细胞质中发现圆形包涵体（IB）样颗粒和一些不规则的较大的IB样颗粒。为了进一步研究 NTU-LY-1 细胞中的 CPE，进行了细胞质多角体病毒、传染性黄斑病毒和裸体病毒 (PnV) 的逆转录-PCR 筛选。结果表明，NTU-LY-1 细胞从培养的第 1 天到第 15 天持续感染 PnV。NTU-LY-1 细胞进一步进行蛋白质印迹和间接免疫荧光测定以确认 PnV 感染。基于透射电子显微镜观察，NTU-LY-1 细胞中的 CPE 与 PnV 同源的 NTU-Pn-HF 细胞系（裸露达的细胞系）中的 CPE 不同。在新接种的 NTU-LY-1 细胞中发现了膜结合的 IB。裂解的 NTU-LY-1 细胞在培养 15 天后形成许多微粒体，在微粒体中可以区分三种不同类型的 IB，包括膜结合、原纤维结合和鞘结合 IB。培养 15 天后，未裂解的 NTU-LY-1 细胞的细胞质包含非膜结合的病毒源基质的拉链样阵列和由两个膜限制的平行排病毒颗粒。这些病毒颗粒被纯化并显示出 PnV 形态。这是第一项在异源细胞系中显示持续 PnV 感染的研究。研究结果提出了一种新的微生物控制策略；而且，