Institute of Virology, Faculty of Veterinary Medicine, Leipzig University, Leipzig, Germany.
Institute of Medical Microbiology and Virology, Medical Faculty, Leipzig University, Leipzig, Germany.
Front Cell Infect Microbiol. 2022 Feb 4;12:823181. doi: 10.3389/fcimb.2022.823181. eCollection 2022.
The mosquito-borne Usutu virus (USUV) is a zoonotic flavivirus and an emerging pathogen. So far therapeutical options or vaccines are not available in human and veterinary medicine. The bioenergetic profile based on extracellular flux analysis revealed an USUV infection-associated significant increase in basal and stressed glycolysis on Vero and with a tendency for basal glycolysis on the avian cell line TME-R derived from Eurasian blackbirds. On both cell lines this was accompanied by a significant drop in the metabolic potential of glycolysis. Moreover, glycolysis contributed to production of virus progeny, as inhibition of glycolysis with 2-deoxy-D-glucose reduced virus yield on Vero by one log step. Additionally, the increase in glycolysis observed on Vero cells after USUV infection was lost after the addition of exogenous type I interferon (IFN) β. To further explore the contribution of the IFN response pathway to the impact of USUV on cellular metabolism, USUV infection was characterized on human A549 respiratory cells with a knockout of the type I IFN receptor, either solely or together with the receptor of type III IFN. Notably, only the double knockout of types I and III IFN receptor increased permissiveness to USUV and supported viral replication together with an alteration of the glycolytic activity, namely an increase in basal glycolysis to an extent that a further increase after injection of metabolic stressors during extracellular flux analysis was not noted. This study provides evidence for glycolysis as a possible target for therapeutic intervention of USUV replication. Moreover, presented data highlight type I and type III IFN system as a determinant for human host cell permissiveness and for the infection-associated impact on glycolysis.
蚊媒传播的乌苏图病毒（USUV）是一种人畜共患的黄病毒，也是一种新兴的病原体。到目前为止，人类和兽医医学中还没有治疗选择或疫苗。基于细胞外通量分析的生物能量谱显示，USUV 感染与基础和应激糖酵解显著增加有关，在 Vero 细胞和源自欧亚椋鸟的禽源细胞系 TME-R 上，基础糖酵解有增加的趋势。在这两种细胞系上，糖酵解的代谢潜力都显著下降。此外，糖酵解有助于病毒后代的产生，因为用 2-脱氧-D-葡萄糖抑制糖酵解可使 Vero 细胞上的病毒产量降低一个对数级。此外，在 USUV 感染后观察到的 Vero 细胞中糖酵解的增加在添加外源性 I 型干扰素 (IFN) β 后消失。为了进一步探讨 IFN 反应途径对 USUV 对细胞代谢影响的贡献，在人 A549 呼吸道细胞中对 USUV 感染进行了特征描述，这些细胞敲除了 I 型 IFN 受体，要么单独敲除，要么与 III 型 IFN 受体一起敲除。值得注意的是，只有 I 型和 III 型 IFN 受体的双重敲除增加了对 USUV 的易感性，并支持病毒复制，同时改变糖酵解活性，即基础糖酵解增加到一定程度，以至于在细胞外通量分析中注射代谢应激物后不会再增加。这项研究为糖酵解作为 USUV 复制治疗干预的可能靶点提供了证据。此外，所提供的数据强调了 I 型和 III 型 IFN 系统是决定人宿主细胞易感性和感染相关糖酵解影响的决定因素。
