Hu Xuming, Zhu Wenqi, Chen Shihao, Liu Yangyang, Sun Zhen, Geng Tuoyu, Wang Xiaoyan, Gao Bo, Song Chengyi, Qin Aijian, Cui Hengmi
Institute of Epigenetics and Epigenomics, Yangzhou University, No. 48 East Wenhui Road, Yangzhou, Jiangsu, 225009, People's Republic of China.
College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, People's Republic of China.
Arch Virol. 2016 Jun;161(6):1623-32. doi: 10.1007/s00705-016-2833-8. Epub 2016 Mar 26.
Endogenous retroviruses (ERVs) are important retroelements that reside in host genomes. However, ERV expression patterns and regulatory mechanisms are poorly understood. In this study, chicken embryo fibroblasts (CEFs) and MSB1 cells infected with Marek's disease virus (MDV) exhibited significantly increased expression of env from the endogenous retrovirus ALVE. In contrast, env expression was significantly lower in CEF and MSB1 cells infected with exogenous avian leukosis virus J (ALVJ) at the early infection stage. Furthermore, env was found to be ubiquitously expressed in various chicken tissues, with high expression in certain tissues at 2 days of age and low levels in most tissues, including immune organs (thymus, spleen and bursa) as well as the brain and heart, at 35 days of age. Sequence analysis revealed miR-155 target sites in env transcripts, which was verified using a firefly luciferase reporter assay, and treatment with miR-155 agomir significantly decreased levels of env transcripts in MSB1 and CEF cells. Together, these findings suggest that the env gene from the endogenous retrovirus ALVE is regulated by miR-155.
内源性逆转录病毒（ERVs）是存在于宿主基因组中的重要逆转录元件。然而，ERV的表达模式和调控机制仍知之甚少。在本研究中，感染马立克氏病病毒（MDV）的鸡胚成纤维细胞（CEFs）和MSB1细胞中，内源性逆转录病毒ALVE的env表达显著增加。相比之下，在感染外源性禽白血病病毒J（ALVJ）的早期阶段，CEF和MSB1细胞中的env表达显著降低。此外，发现env在鸡的各种组织中普遍表达，在2日龄时某些组织中表达较高，而在35日龄时大多数组织（包括免疫器官（胸腺、脾脏和法氏囊）以及脑和心脏）中表达水平较低。序列分析揭示了env转录本中的miR-155靶位点，这通过萤火虫荧光素酶报告基因测定得到验证，并且用miR-155激动剂处理显著降低了MSB1和CEF细胞中env转录本的水平。总之，这些发现表明内源性逆转录病毒ALVE的env基因受miR-155调控。
