Abstract:
Enterovirus D68 (EV-D68) is a picornavirus associated with severe respiratory illness and a paralytic disease called acute flaccid myelitis in infants. Currently, no protective vaccines or antivirals are available to combat this virus. Like other enteroviruses, EV-D68 uses components of the cellular autophagy pathway to rewire membranes for its replication. Here, we show that transcription factor EB (TFEB), the master transcriptional regulator of autophagy and lysosomal biogenesis, is crucial for EV-D68 infection. Knockdown of TFEB attenuated EV-D68 genomic RNA replication but did not impact viral binding or entry into host cells. The 3C protease of EV-D68 cleaves TFEB at the N-terminus at glutamine 60 (Q60) immediately post-peak viral RNA replication, disrupting TFEB-RagC interaction and restricting TFEB transport to the surface of the lysosome. Despite this, TFEB remained mostly cytosolic during EV-D68 infection. Overexpression of a TFEB mutant construct lacking the RagC-binding domain, but not the wild-type construct, blocks autophagy and increases EV-D68 nonlytic release in H1HeLa cells but not in autophagy-defective ATG7 KO H1HeLa cells. Our results identify TFEB as a vital host factor regulating multiple stages of the EV-D68 lifecycle and suggest that TFEB could be a promising target for antiviral development against EV-D68.
OBJECTIVE: Enteroviruses are among the most significant causes of human disease. Some enteroviruses are responsible for severe paralytic diseases such as poliomyelitis or acute flaccid myelitis. The latter disease is associated with multiple non-polio enterovirus species, including enterovirus D68 (EV-D68), enterovirus 71, and coxsackievirus B3 (CVB3). Here, we demonstrate that EV-D68 interacts with a host transcription factor, transcription factor EB (TFEB), to promote viral RNA(vRNA) replication and regulate the egress of virions from cells. TFEB was previously implicated in the viral egress of CVB3, and the viral protease 3C cleaves TFEB during infection. Here, we show that EV-D68 3C protease also cleaves TFEB after the peak of vRNA replication. This cleavage disrupts TFEB interaction with the host protein RagC, which changes the localization and regulation of TFEB. TFEB lacking a RagC-binding domain inhibits autophagic flux and promotes virus egress. These mechanistic insights highlight how common host factors affect closely related, medically important viruses differently.
摘要:
肠道病毒D68(EV-D68)是一种与严重呼吸道疾病和麻痹性疾病有关的微小核糖核酸病毒,称为婴儿急性弛缓性脊髓炎。目前,没有保护性疫苗或抗病毒药物来对抗这种病毒。像其他肠道病毒一样,EV-D68使用细胞自噬途径的成分重新连接膜以进行复制。这里,我们显示转录因子EB(TFEB),自噬和溶酶体生物发生的主要转录调节因子,对于EV-D68感染至关重要。TFEB的敲减减弱EV-D68基因组RNA复制,但不影响病毒结合或进入宿主细胞。EV-D68的3C蛋白酶在病毒RNA复制高峰后立即在谷氨酰胺60(Q60)的N末端切割TFEB,破坏TFEB-RagC相互作用并限制TFEB运输到溶酶体表面。尽管如此,TFEB在EV-D68感染期间大部分保持细胞溶质。缺乏RagC结合结构域的TFEB突变体构建体的过表达,但不是野生型结构,在S1HeLa细胞中阻断自噬并增加EV-D68非裂解释放,但在自噬缺陷型ATG7KOS1HeLa细胞中不存在。我们的结果确定TFEB是调节EV-D68生命周期的多个阶段的重要宿主因子,并表明TFEB可能是针对EV-D68的抗病毒开发的有希望的目标。
目的:肠道病毒是人类疾病的最重要原因之一。一些肠道病毒导致严重的麻痹性疾病,如脊髓灰质炎或急性弛缓性脊髓炎。后一种疾病与多种非脊髓灰质炎肠道病毒有关,包括肠道病毒D68(EV-D68),肠道病毒71型和柯萨奇病毒B3(CVB3)。这里,我们证明EV-D68与宿主转录因子相互作用,转录因子EB(TFEB),促进病毒RNA(vRNA)复制并调节病毒粒子从细胞中的流出。TFEB先前与CVB3的病毒外泄有关,并且病毒蛋白酶3C在感染期间切割TFEB。这里,我们显示EV-D683C蛋白酶也在vRNA复制达到峰值后切割TFEB。这种切割破坏了TFEB与宿主蛋白RagC的相互作用,这改变了TFEB的定位和调控。缺乏RagC结合结构域的TFEB抑制自噬通量并促进病毒外泄。这些机制的见解突出了共同的宿主因素如何影响密切相关的,医学上重要的病毒不同。