Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 0454 Oslo, Norway.
Department of Basic Science and Aquatic Medicine, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 0454 Oslo, Norway.
Viruses. 2019 Sep 5;11(9):824. doi: 10.3390/v11090824.
Piscine orthoreovirus (PRV-1) can cause heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (). The virus targets erythrocytes in the acute peak phase, followed by cardiomyocytes, before the infection subsides into persistence. The persistent phase is characterized by high level of viral RNA, but low level of viral protein. The origin and nature of persistent PRV-1 are not clear. Here, we analyzed for viral persistence and activity in various tissues and cell types in experimentally infected Atlantic salmon. Plasma contained PRV-1 genomic dsRNA throughout an 18-week long infection trial, indicating that viral particles are continuously produced and released. The highest level of PRV-1 RNA in the persistent phase was found in kidney. The level of PRV-1 ssRNA transcripts in kidney was significantly higher than that of blood cells in the persistent phase. In-situ hybridization assays confirmed that PRV-1 RNA was present in erythroid progenitor cells, erythrocytes, macrophages, melano-macrophages and in some additional un-characterized cells in kidney. These results show that PRV-1 establishes a productive, persistent infection in Atlantic salmon and that erythrocyte progenitor cells are PRV target cells.
鱼类正呼肠孤病毒（PRV-1）可引起养殖大西洋鲑鱼的心肌和骨骼肌炎症（HSMI）。病毒在急性高峰期靶向红细胞，然后是心肌细胞，然后感染进入持续状态。持续状态的特征是高水平的病毒 RNA，但病毒蛋白水平低。持续 PRV-1 的起源和性质尚不清楚。在这里，我们分析了实验感染大西洋鲑鱼中各种组织和细胞类型中的病毒持续存在和活性。在长达 18 周的感染试验中，血浆中含有 PRV-1 基因组 dsRNA，表明病毒颗粒不断产生和释放。在持续状态下，PRV-1 RNA 的水平在肾脏中最高。在持续状态下，肾脏中 PRV-1 的 ssRNA 转录本水平明显高于血细胞。原位杂交检测证实 PRV-1 RNA 存在于红细胞祖细胞、红细胞、巨噬细胞、黑素巨噬细胞和肾脏中的一些其他未明细胞中。这些结果表明 PRV-1 在大西洋鲑鱼中建立了一种具有生产力的持续感染，并且红细胞祖细胞是 PRV 的靶细胞。
