Japanese encephalitis virus (JEV) is a typical insect-borne flavivirus and an important zoonotic pathogen that causes human viral encephalitis and reproductive failure in pigs. Various strategies were utilized by JEV to facilitate its replication. It is important to identify key molecules that mediate JEV infection, as well as to investigate their underlying mechanism. In this study, the critical role of high-mobility group box 1 (HMGB1), a non-histone, DNA-binding protein, was assessed in JEV propagation. Upon JEV infection, the HMGB1 mRNA and protein levels were down-regulated at late infection in Huh7 cells. JEV replication was significantly enhanced with HMGB1 knock-down by siRNA and knock-out by the CRISPR/Cas9 system, whereas JEV growth was restricted in HMGB1-over-expressed Huh7 cells. Further investigation showed that HMGB1 suppressed MAPK pathway, and demonstrated that the weakening of MAPK pathway negatively regulated JEV infection. Together, these results suggested that JEV restricted HMGB1 expression to maintain MAPK pathway activation for viral replication. Our data showed that HMGB1 played a key role in JEV infection, providing the potential for the development of a novel drug to combat JEV infection.

日本脑炎病毒（JEV）是一种典型的虫媒黄病毒，是一种重要的人畜共患病病原体，可引起猪人病毒性脑炎和生殖功能障碍。JEV 使用了各种策略来促进其复制。确定介导 JEV 感染的关键分子并研究其潜在机制非常重要。在这项研究中，评估了非组蛋白 DNA 结合蛋白高迁移率族框 1 (HMGB1) 在 JEV 传播中的关键作用。在 JEV 感染后，HMGB1 mRNA 和蛋白质水平在 Huh7 细胞的晚期感染中下调。JEV 复制通过 siRNA 敲低 HMGB1 和 CRISPR/Cas9 系统敲除显着增强，而 JEV 生长在 HMGB1 过表达的 Huh7 细胞中受到限制。进一步的研究表明HMGB1抑制了MAPK通路，表明MAPK通路的减弱对JEV感染负调控。总之，这些结果表明 JEV 限制 HMGB1 表达以维持 MAPK 通路激活以进行病毒复制。我们的数据表明 HMGB1 在 JEV 感染中发挥了关键作用，为开发一种对抗 JEV 感染的新型药物提供了潜力。