College of Animal Science and Veterinary Medicine, Sino-German Cooperative Research Centre for Zoonosis of Animal Origin of Shandong Province, Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, 61 Daizong Street, Tai'an, 271018, Shandong, China.
Key Laboratory of Precision Oncology of Shandong Higher Education, Institute of Precision Medicine, Jining Medical University, Jining, 272067, Shandong, China.
Vet Res. 2020 Feb 18;51(1):12. doi: 10.1186/s13567-020-00742-8.
High-mobility group box 1 protein (HMGB1) shows endogenous damage-associated molecular patterns (DAMPs) and is also an early warning protein that activates the body's innate immune system. Here, the full-length coding sequence of HMGB1 was cloned from the spleen of Cherry Valley duck and analyzed. We find that duck HMGB1(duHMGB1) is mostly located in the nucleus of duck embryo fibroblast (DEF) cells under normal conditions but released into the cytoplasm after lipopolysaccharide (LPS) stimulation. Knocking-down or overexpressing duHMGB1 had no effect on the baseline apoptosis rate of DEF cells. However, overexpression increased weakly apoptosis after LPS activation. In addition, overexpression strongly activated the IFN-I/IRF7 signaling pathway in DEF cells and significantly increased the transcriptional level of numerous pattern recognition receptors (PRRs), pro-inflammatory cytokines (IL-6, TNF-α), IFNs and antiviral molecules (OAS, PKR, Mx) starting from 48 h post-transfection. Overexpression of duHMGB1 strongly impacted duck virus replication, either by inhibiting it from the first stage of infection for novel duck reovirus (NDRV) and at late stage for duck Tembusu virus (DTMUV) or duck plague virus (DPV), or promoting replication at early stage for DTMUV and DPV infection. Importantly, data from duHMGB1 overexpression and knockdown experiments, time-dependent DEF cells transcriptional immune responses suggest that duHMGB1 and RIG-I receptor might cooperate to promote the expression of antiviral proteins after NDRV infection, as a potential mechanism of duHMGB1-mediated antiviral activity.
高迁移率族蛋白 B1（HMGB1）表现出内源性损伤相关分子模式（DAMPs），也是激活机体固有免疫系统的早期预警蛋白。本研究从樱桃谷鸭脾脏中克隆了 HMGB1 的全长编码序列并进行了分析。结果发现，鸭 HMGB1（duHMGB1）在正常条件下主要位于鸭胚胎成纤维细胞（DEF）细胞核内，但在脂多糖（LPS）刺激后释放到细胞质中。敲低或过表达 duHMGB1 对 DEF 细胞的基础凋亡率没有影响。然而，过表达在 LPS 激活后会弱促进细胞凋亡。此外，过表达在 DEF 细胞中强烈激活 IFN-I/IRF7 信号通路，并显著增加了模式识别受体（PRRs）、促炎细胞因子（IL-6、TNF-α）、IFNs 和抗病毒分子（OAS、PKR、Mx）的转录水平，起始时间为转染后 48 h。过表达 duHMGB1 强烈影响鸭病毒复制，无论是抑制新型鸭呼肠孤病毒（NDRV）的感染早期阶段还是晚期阶段的鸭坦布苏病毒（DTMUV）和鸭瘟病毒（DPV），还是促进 DTMUV 和 DPV 感染的早期阶段复制。重要的是，过表达和敲低 duHMGB1 实验以及 DEF 细胞的时间依赖性转录免疫反应数据表明，duHMGB1 和 RIG-I 受体可能在 NDRV 感染后协同促进抗病毒蛋白的表达，这可能是 duHMGB1 介导抗病毒活性的潜在机制。
