Wild boar-derived hepatitis E (HEV) genotype 3 virus has been successfully isolated in cell lines of human origin only. Considering the zoonotic potential and possible extrahepatic localisation of genotype 3 strain, it is important to investigate the viability of cell lines of different animal and tissue origins. Therefore, the objective of the present study was to determine the permissiveness of non-human primate (MARC-145 and Vero) and swine (PK-15) cell lines of kidney origin, and a mouse neuroblastoma (Neuro-2a) cell line for isolation of wild boar-derived HEV genotype 3. This study showed that MARC-145, PK-15, Neuro-2a and Vero cell lines were permissive to wild boar-derived HEV genotype 3 subtype 3i harbouring viral genome equivalents of 1.12 × 107 copies/ml, 2.38 × 105 copies/ml, 2.97 × 107 copies/ml and 4.01 × 107 copies/ml after five serial passages respectively. In all permissive cell lines, HEV was continuously recovered from growth medium between five and at least 28 days post-infection. Peak loads of HEV genome equivalents were observed on days 7, 12, 19 and 30 in MARC-145 (2.88 × 107 copies/ml), Vero (4.23 × 106 copies/ml), Neuro-2a (3.15 × 106 copies/ml) and PK-15 (2.24 × 107 copies/ml) cell lines respectively. In addition, successful virus isolation was confirmed by immunofluorescence assay targeting HEV capsid protein and sequencing of HEV isolate retrieved from cell cultures. This study showed that wild boar-derived HEV genotype 3 subtype 3i strain was capable of infecting cell lines of animal origin, including primate and porcine kidney cells (MARC-145, PK-15 and Vero), and mouse neuroblastoma cells (Neuro-2a), supporting the notion of the capacity of HEV genotype 3 to cross the species barrier and extra-hepatic localisation of the virus. These findings warrant further studies of tested cell lines to investigate their capacity as an efficient system for HEV propagation. HEV isolates from other wild animal hosts should be isolated on tested cell lines in order to generate more data on HEV transmission between wild animal populations and their role as sources of human infections.

中文翻译：

---

从野猪中分离出的戊型肝炎E基因型3病毒能够在非人灵长类和猪肾细胞以及小鼠神经母细胞瘤细胞中复制

仅在人类起源的细胞系中成功分离了野猪衍生的戊型肝炎（HEV）基因型3病毒。考虑到人畜共患的潜力和基因型3株可能的肝外定位，研究不同动物和组织来​​源的细胞系的生存能力很重要。因此，本研究的目的是确定肾源性非人类灵长类动物（MARC-145和Vero）和猪（PK-15）细胞系以及小鼠神经母细胞瘤（Neuro-2a）细胞系的允许性。野猪衍生的HEV基因型3的分离。这项研究表明，MARC-145，PK-15，Neuro-2a和Vero细胞系允许携带1.12×107拷贝的病毒基因组等价物的野猪衍生的HEV基因型3亚型3i /ml、2.38×105拷贝/ml、2.97×107拷贝/ ml和4。经过五次连续传代后，得出01×107拷贝/ ml。在所有允许的细胞系中，在感染后五至至少28天之间，从生长培养基中连续回收HEV。在第7、12、19和30天，在MARC-145（2.88×107拷贝/毫升），Vero（4.23×106拷贝/毫升），Neuro-2a（3.15×106拷贝/毫升）中观察到HEV基因组当量的峰值负荷。 ）和PK-15（2.24×107拷贝/ ml）细胞系。此外，通过针对HEV衣壳蛋白的免疫荧光测定和从细胞培养物中回收的HEV分离株的测序，证实成功分离了病毒。这项研究表明，野猪衍生的HEV基因型3亚型3i菌株能够感染动物来源的细胞系，包括灵长类和猪肾细胞（MARC-145，PK-15和Vero）以及小鼠神经母细胞瘤细胞（Neuro-2a） ），支持HEV基因型3越过病毒的物种屏障和肝外定位的能力的概念。这些发现需要对测试的细胞系进行进一步研究，以研究其作为HEV繁殖有效系统的能力。为了从野生动物种群之间的HEV传播及其作为人类感染源的作用中获得更多数据，应将其他野生动物宿主的HEV分离株分离出来。