Porcine epidemic diarrhea virus (PEDV) is a causative agent of a highly contagious enteric disease in swine of all ages, leading to severe economic losses for the swine industry in many countries. One of the most effective approaches in controlling PEDV infection is vaccination. The ORF3 accessory protein has been proposed as a crucial viral virulence factor in a natural host. However, due to the lack of an extensive comparative study of ORF3, exactly how the ORF3 takes part in virus replication and pathogenesis as well as its role in host-virus interaction is unclear. In this review, we aim to discuss the current knowledge of ORF3 concerning its dispensability for viral replication in vitro, ability to modulate host responses, contribution to virus pathogenicity, and research gaps among ORF3 functional studies. These will be beneficial for further studies to a better understanding of PEDV biology and PEDV vaccine development.

中文翻译：

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PEDV 与其宿主之间的相互作用：仔细观察 ORF3 辅助蛋白。

猪流行性腹泻病毒（PEDV）是所有年龄段猪的一种高度传染性肠道疾病的病原体，给许多国家的养猪业造成严重的经济损失。控制 PEDV 感染的最有效方法之一是接种疫苗。ORF3 辅助蛋白已被提议作为天然宿主中的关键病毒毒力因子。然而，由于缺乏对 ORF3 的广泛比较研究，ORF3 究竟如何参与病毒复制和发病机制及其在宿主-病毒相互作用中的作用尚不清楚。在这篇综述中，我们旨在讨论 ORF3 的当前知识，涉及其体外病毒复制的可有性、调节宿主反应的能力、对病毒致病性的贡献以及 ORF3 功能研究之间的研究差距。