International Joint Agriculture Research Center for Animal Bio-breeding, Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, China.
Yazhouwan National Laboratory, Sanya, 572024, China.
Virol J. 2024 Aug 8;21(1):181. doi: 10.1186/s12985-024-02454-3.
The orf virus (ORFV) poses a serious threat to the health of domestic small ruminants (i.e., sheep and goats) and humans on a global scale, causing around $150 million in annual losses to livestock industry. However, the host factors involved in ORFV infection and replication are still elusive. In this study, we compared the RNA-seq profiles of ORFV-infected or non-infected sheep testicular interstitial cells (STICs) and identified a novel host gene, potassium voltage-gated channel subfamily E member 4 (KCNE4), as a key host factor involved in the ORFV infection. Both RNA-seq data and RT-qPCR assay revealed a significant increase in the expression of KCNE4 in the infected STICs from 9 to 48 h post infection (hpi). On the other hand, the RT-qPCR assay detected a decrease in ORFV copy number in both the STICs transfected by KCNE4 siRNA and the KCNE4 knockout (KO) HeLa cells after the ORFV infection, together with a reduced fluorescence ratio of ORFV-GFP in the KO HeLa cells at 24 hpi, indicating KCNE4 to be critical for the ORFV infection. Furthermore, the attachment and internalization assays showed decreased ORFV attachment, internalization, replication, and release by the KO HeLa cells, demonstrating a potential inhibition of ORFV entry into the cells by KCNE4. Pretreatment with the KCNE4 inhibitors such as quinidine and fluoxetine significantly repressed the ORFV infection. All our findings reveal KCNE4 as a novel host regulator of the ORFV entry and replication, shedding new insight into the interactive mechanism of ORFV infection. The study also highlights the K channels as possible druggable targets to impede viral infection and disease.
口疮病毒（ORFV）对全球范围内的家养小反刍动物（即绵羊和山羊）和人类的健康构成严重威胁，给畜牧业造成约 1.5 亿美元的年损失。然而，ORFV 感染和复制所涉及的宿主因素仍不清楚。在这项研究中，我们比较了 ORFV 感染或未感染的绵羊睾丸间质细胞（STIC）的 RNA-seq 图谱，鉴定出一种新型宿主基因钾电压门控通道亚家族 E 成员 4（KCNE4），作为参与 ORFV 感染的关键宿主因子。RNA-seq 数据和 RT-qPCR 检测均显示，感染后 9 至 48 小时，感染的 STIC 中 KCNE4 的表达显著增加。另一方面，RT-qPCR 检测到，在转染 KCNE4 siRNA 的 STIC 和 KCNE4 敲除（KO）HeLa 细胞中，ORFV 拷贝数在感染后减少，在 24 hpi 时 KO HeLa 细胞中的 ORFV-GFP 荧光比值降低，表明 KCNE4 对 ORFV 感染至关重要。此外，附着和内化实验表明，KO HeLa 细胞中 ORFV 的附着、内化、复制和释放减少，表明 KCNE4 可能抑制 ORFV 进入细胞。用 KCNE4 抑制剂如奎尼丁和氟西汀预处理可显著抑制 ORFV 感染。我们所有的发现表明 KCNE4 是 ORFV 进入和复制的新型宿主调节剂，为 ORFV 感染的相互作用机制提供了新的见解。该研究还强调了 K 通道作为可能的药物靶点，以阻止病毒感染和疾病。
