PDF(Pubmed)
Abstract：
Bovine viral diarrhea virus (BVDV) is a highly contagious viral disease which causes economic losses to the cattle industry. Ethyl gallate (EG) is a phenolic acid derivative which has various potentials to modulate the host response to pathogens, such as via antioxidant activity, antibacterial activity, inhibition of the production of cell adhesion factors, and so on. This study aimed to evaluate if EG influences BVDV infection in Madin-Darby Bovine Kidney (MDBK) cells, and to understand the antiviral mechanism. Data indicated that EG effectively inhibited BVDV infection by co-treatment and post-treatment in MDBK cells with noncytotoxic doses. In addition, EG suppressed BVDV infection at an early stage of the viral life cycle by blocking entry and replication steps but not viral attachment and release. Moreover, EG strongly inhibited BVDV infection by promoting interferon-induced transmembrane protein 3 (IFITM3) expression, which localized to the cytoplasm. The protein level of cathepsin B was significantly reduced by BVDV infection, whereas with treatment with EG, it was significantly enhanced. The fluorescence intensities of acridine orange (AO) staining were significantly decreased in BVDV-infected cells but increased in EG-treated cells. Finally, Western blot and immunofluorescence analyses demonstrated that EG treatment significantly enhanced the protein levels of autophagy markers LC3 and p62. Chloroquine (CQ) significantly increased IFITM3 expression, and Rapamycin significantly decreased it. Thus, EG may regulate IFITM3 expression through autophagy. Our results showed that EG could have a solid antiviral activity on BVDV replication in MDBK cells via increased IFITM3 expression, lysosomal acidification, protease activity, and regulated autophagy. EG might have value for further development as an antiviral agent.
摘要：
牛病毒性腹泻病毒（BVDV）是一种高度传染性的病毒性疾病，给养牛业造成了经济损失。没食子酸乙酯（EG）是一种酚酸衍生物，具有多种调节宿主对病原体反应的潜力，例如通过抗氧化活性，抗菌活性，抑制细胞粘附因子的产生，等等。这项研究旨在评估EG是否影响Madin-Darby牛肾（MDBK）细胞中的BVDV感染，了解抗病毒机制。数据表明EG通过用非细胞毒性剂量在MDBK细胞中的共同治疗和后处理有效地抑制BVDV感染。此外,EG在病毒生命周期的早期通过阻断进入和复制步骤而不是病毒附着和释放来抑制BVDV感染。此外，EG通过促进干扰素诱导的跨膜蛋白3(IFITM3)表达强烈抑制BVDV感染,定位于细胞质。BVDV感染可显著降低组织蛋白酶B的蛋白水平,而用EG治疗，显着增强。吖啶橙（AO）染色的荧光强度在BVDV感染的细胞中显着降低，但在EG处理的细胞中增加。最后,蛋白质印迹和免疫荧光分析显示EG处理显著增强自噬标记物LC3和p62的蛋白水平。氯喹（CQ）显着增加IFITM3表达，雷帕霉素显著降低。因此，EG可能通过自噬调节IFITM3的表达。我们的结果表明，EG可以通过增加IFITM3表达对MDBK细胞中BVDV复制具有坚实的抗病毒活性，溶酶体酸化，蛋白酶活性，调节自噬。EG可能具有作为抗病毒剂的进一步发展的价值。
