ABSTRACT

Almost a billion people worldwide are chronically undernourished. Herein, using a mouse model of coxsackievirus B3 (CVB3) infection, we report that a single day of food restriction (FR) markedly increases susceptibility to attenuated enterovirus infection, replication, and disease. These “pro-viral” effects, which are rapidly-reversed by the restoration of food, are mediated by several genes whose expression is altered by FR, and which support CVB3 replication. Central to this is TFEB, a protein whose expression and activation status are rapidly increased by FR. TFEB, which regulates the transcription of >100 genes involved in macroautophagy/autophagy and lysosomal biogenesis, responds similarly to both FR and CVB3 infection and plays a pivotal role in determining host susceptibility to CVB3. We propose that, by upregulating TFEB, FR generates an intracellular environment that is more hospitable to the incoming virus, facilitating its replication. This interplay between nutritional status and enterovirus replication has implications for human health and, perhaps, for the evolution of these viruses.

Abbreviations: Atg/ATG: autophagy-related; CAR: Coxsackievirus and adenovirus receptor; Cas9: CRISPR associated protein 9; Cre: recombinase that causes recombination; CRISPR: clustered regularly interspaced short palindromic repeats; Ctsb/CTSB: cathepsin B; CVB3: coxsackievirus B3; DsRedCVB3: a recombinant CVB3 that encodes the Discosoma red fluorescent protein; EL: elastase; FR: food restriction; GFP: green fluorescent protein; gRNA: guide RNA; HBSS: Hanks Buffered Salt Solution; LYNUS: lysosomal nutrient sensing machinery; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; MFI: mean fluorescence intensity; MOI: multiplicity of infection; MTOR: mechanistic target of rapamycin kinase; Nluc: nanoluciferase; NlucCVB3: a recombinant CVB3 encoding nanoluciferase; pfu: plaque-forming unit(s); p.i.: post infection; rCVB: recombinant coxsackievirus B3; RPS6KB/p70S6K: ribosomal protein S6 kinase; RT: room temperature; siRNA: small interfering RNA; TFEB: transcription factor EB; tg: transgenic; TUBB: β-tubulin; UNINF: uninfected; wrt: with respect to; WT: wild type.

摘要

全世界近 10 亿人长期营养不良。在此，我们使用柯萨奇病毒 B3 (CVB3) 感染的小鼠模型报告说，一天的食物限制 (FR) 显着增加了对减毒肠道病毒感染、复制和疾病的易感性。这些“前病毒”效应会被食物恢复迅速逆转，由几个基因介导，这些基因的表达被 FR 改变，并支持 CVB3 复制。其核心是 TFEB，一种蛋白质的表达和激活状态会因 FR 迅速增加。TFEB 调节参与巨自噬/自噬和溶酶体生物发生的 100 多个基因的转录，对 FR 和 CVB3 感染的反应相似，并在确定宿主对 CVB3 的易感性中起关键作用。我们建议，通过上调 TFEB，FR 产生一个更适合传入病毒的细胞内环境，促进其复制。营养状况和肠道病毒复制之间的这种相互作用对人类健康有影响，也许对这些病毒的进化也有影响。

缩写： Atg/ATG：自噬相关；CAR：柯萨奇病毒和腺病毒受体；Cas9：CRISPR相关蛋白9；Cre：引起重组的重组酶；CRISPR：成簇的规则间隔短回文重复；Ctsb/CTSB：组织蛋白酶 B；CVB3：柯萨奇病毒B3；DsRedCVB3：编码Discosoma红色荧光蛋白的重组CVB3；EL：弹性蛋白酶；FR：食物限制；GFP：绿色荧光蛋白；gRNA：引导RNA；HBSS：汉克斯缓冲盐溶液；LYNUS：溶酶体营养传感机制；MAP1LC3/LC3：微管相关蛋白1轻链3；MFI：平均荧光强度；MOI：感染复数；MTOR：雷帕霉素激酶的机制靶点；Nluc：纳米荧光素酶；NlucCVB3：编码纳米荧光素酶的重组CVB3；pfu：斑块形成单位；pi：感染后；rCVB：重组柯萨奇病毒B3；RPS6KB/p70S6K：核糖体蛋白S6激酶；RT：室温；siRNA：小干扰RNA；TFEB：转录因子EB；tg：转基因；TUBB：β-微管蛋白；UNINF：未感染；wrt：关于；WT：野生型。