Transmissible spongiform encephalopathies, or prion diseases, are fatal neurodegenerative diseases affecting humans and animals. Although many host tissues express PrP^C (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 ^C（朊病毒复制所必需的），但相对较少的细胞类型积累了显着水平的感染性，包括神经系统中的神经元和其他细胞类型，以及次级淋巴器官中的滤泡树突细胞。这表明组织或细胞特异性受体或辅助因子可以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）是古代逆转录病毒整合到宿主种系中的残余物，可能代表了这样的辅因子之一。我们使用 RT-qPCR 检测了羊痒病感染对皮下接种后不同时间点绵羊次级淋巴组织中三个绵羊 ERV 家族（enJSRV/β1-OERV、γ1-OERV、γ2-OERV）表达的影响。这些 OERV 在未感染绵羊的肩胛前淋巴结和脾脏中组成型表达。然而，与之前对感染朊病毒的小鼠和猕猴大脑中ERV表达的研究相比，我们无法找到令人信服的证据证明瘙痒病感染后相同组织中OERV的特异性差异表达。这项研究首次量化了绵羊淋巴组织中潜在功能性 OERV 转录本的表达，提出了关于宿主免疫功能后果的有趣问题。