In the present study, we have developed a continuous cell line from the heart tissue of the Oreochromis niloticus and used for studying susceptibility to tilapia lake virus (TiLV). The cell line, designated as OnH, has been subcultured up to 82 passages. The optimal growth of OnH cells was observed at 28–32 °C in iL-15 medium supplemented with 20 % fetal bovine serum. Karyotype analysis revealed that the modal chromosome number of OnH cells was 44. Partial amplification and sequencing of 16S rRNA gene confirmed the origin of OnH cell line from O. niloticus. Immunophenotyping revealed that OnH cells were of epithelial origin. These cells were successfully transfected with pAcGFP1-N1 mammalian expression vector. OnH cells showed cytopathic effects following inoculation with TiLV. The virus titration study indicated that the cells were highly susceptible to TiLV with TCID₅₀ value of 10^5.3/mL. The qRT-PCR studies revealed that the optimal temperature for TiLV replication in OnH cells was 28 °C. Further, transmission electron microscopy of TiLV-infected OnH cells showed a number of electron-dense virus particles measuring 60−90 nm diameter, which were enclosed in the vesicles in the cytoplasm. Therefore, the newly established OnH cell line provides a valuable tool for isolation of viruses from disease cases suspected to be of viral etiology in this candidate species' and also for transgenic and genetic manipulation studies.

在本研究中，我们从尼罗罗非鱼的心脏组织中开发了一个连续的细胞系，用于研究对罗非鱼湖病毒 (TiLV) 的易感性。命名为 OnH 的细胞系已传代最多 82 代。OnH 细胞在 28-32°C 下在补充有 20% 胎牛血清的 iL-15 培养基中观察到最佳生长。核型分析显示OnH细胞的模态染色体数为44。16S rRNA基因的部分扩增和测序证实了尼罗罗非鱼OnH细胞系的来源. 免疫表型分析显示 OnH 细胞是上皮来源的。这些细胞被 pAcGFP1-N1 哺乳动物表达载体成功转染。OnH 细胞在接种 TiLV 后显示出细胞病变效应。病毒滴定研究表明细胞对 TiLV 高度敏感，TCID ₅₀值为 10 ^5.3/毫升。qRT-PCR 研究表明，在 OnH 细胞中 TiLV 复制的最佳温度为 28°C。此外，TiLV 感染的 OnH 细胞的透射电子显微镜显示了许多直径为 60-90 nm 的电子致密病毒颗粒，它们被封闭在细胞质的囊泡中。因此，新建立的 OnH 细胞系提供了一种有价值的工具，用于从怀疑是该候选物种的病毒病因的疾病病例中分离病毒，也为转基因和基因操作研究提供了宝贵的工具。