Division of Infection and Immunity, The Roslin Institute, R(D)SVS, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK.
Division of Infection and Immunity, The Roslin Institute, R(D)SVS, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK.
Vet Immunol Immunopathol. 2021 Mar;233:110194. doi: 10.1016/j.vetimm.2021.110194. Epub 2021 Jan 23.
Transmissible spongiform encephalopathies, or prion diseases, are fatal neurodegenerative diseases affecting humans and animals. Although many host tissues express PrP (essential for prion replication), relatively few cell types accumulate significant levels of infectivity, including neurons and other cell types in the nervous system, and follicular dendritic cells in secondary lymphoid organs. This suggests that tissue or cell-specific receptors or cofactors could play a role in controlling differential susceptibility to infection. Endogenous retroviruses (ERV), the remnants of ancient retroviral integration into the host germline, may represent one such cofactor. We examined the effect of scrapie infection on expression of three ovine ERV families (enJSRV/β1-OERV, γ1-OERV, γ2-OERV) in secondary lymphoid tissues of sheep at different time points following subcutaneous inoculation, using RT-qPCR. These OERVs were constitutively expressed in the prescapular lymph node and spleen of uninfected sheep. However, we were unable to find convincing evidence of specific differential expression of OERV in the same tissues following scrapie infection, in contrast to previous studies of ERV expression in brains of prion-infected mice and macaques. This study is the first to quantify the expression of potentially functional OERV transcripts in sheep lymphoid tissues, opening up interesting questions about the consequences for host immune function.
传染性海绵状脑病，或朊病毒病，是影响人类和动物的致命神经退行性疾病。尽管许多宿主组织表达 PrP（朊病毒复制所必需），但只有少数细胞类型会积累大量的感染性，包括神经元和神经系统中的其他细胞类型，以及次级淋巴器官中的滤泡树突状细胞。这表明组织或细胞特异性受体或辅助因子可能在控制对感染的不同易感性方面发挥作用。内源性逆转录病毒 (ERV) 是宿主种系中古老逆转录病毒整合的残余物，可能代表这样的辅助因子之一。我们使用 RT-qPCR 检查了绵羊在皮下接种后不同时间点的次级淋巴组织中，羊传染性海绵状脑病感染对三种绵羊内源性逆转录病毒家族（enJSRV/β1-OERV、γ1-OERV、γ2-OERV）表达的影响。这些 OERV 在未感染绵羊的前腋窝淋巴结和脾脏中持续表达。然而，与先前在感染朊病毒的小鼠和猕猴大脑中研究 ERV 表达的研究相反，我们未能找到 OERV 在同种组织中特异性差异表达的令人信服的证据。这项研究首次定量了潜在功能性 OERV 转录本在绵羊淋巴组织中的表达，这为宿主免疫功能的后果提出了有趣的问题。
