Abstract：
Classical swine fever virus (CSFV) is an enveloped positive-sense RNA virus belonging to the Flaviviridae family. The virus utilizes cellular lipids and manipulates host lipid metabolism to ensure its replication, especially during virus invasion and replication steps. Therefore, identification of the molecular lipid metabolism pathways that are suitable targets is critical for the development of anti-CSFV therapeutics. In this study, we screened the anti-CSFV activity of 12 compounds targeting synthesis of cholesterol and fatty acids, cholesterol esters, and cholesterol transport. We found that 25-hydroxycholesterol (25HC), a regulator of cholesterol metabolism and transport, has potent anti-CSFV activity. Mechanistically, we showed that 25HC inhibited CSFV proliferation by blocking the entry of virions into porcine alveolar macrophages (3D4/21) by decreasing cholesterol abundance in the plasma membrane through activation of acyl-CoA:cholesterol acyltransferase (ACAT). Finally, we revealed that cholesterol 25-hydroxylase (CH25H), a redox enzyme that mediates 25HC production, also restricted CSFV infection via both enzyme activity-dependent and -independent mechanisms. Collectively, our results shed light on the mechanisms by which 25HC inhibits CSFV entry into cells and suggests a potential new therapeutic method against CSFV infection.
摘要：
经典猪瘟病毒（CSFV）是一种有包膜的正义RNA病毒，属于黄病毒科。该病毒利用细胞脂质并操纵宿主脂质代谢以确保其复制，尤其是在病毒入侵和复制过程中。因此,确定作为合适靶标的分子脂质代谢途径对于开发抗CSFV疗法至关重要。在这项研究中,我们筛选了12种针对胆固醇和脂肪酸合成的化合物的抗CSFV活性，胆固醇酯，和胆固醇运输。我们发现25-羟基胆固醇（25HC），胆固醇代谢和运输的调节剂，具有有效的抗CSFV活性。机械上,我们发现25HC通过激活酰基辅酶A:胆固醇酰基转移酶(ACAT)降低质膜胆固醇丰度,阻断病毒粒子进入猪肺泡巨噬细胞(3D4/21),从而抑制CSFV增殖.最后,我们发现胆固醇25-羟化酶（CH25H），一种介导25HC产生的氧化还原酶，还通过酶活性依赖性和非依赖性机制限制了CSFV感染。总的来说，我们的研究结果揭示了25HC抑制CSFV进入细胞的机制,并提出了一种潜在的抗CSFV感染的新治疗方法.
