Mechanisms and consequences of metabolic manipulation by human cytomegalovirus

描述(申请人提供)：人类巨细胞病毒(HCMV)是一种疱疹病毒，是一种普遍存在的人类病原体，感染超过60%的成年人口。它是导致出生缺陷的主要原因，是免疫抑制人群中威胁生命的机会主义因素，也可能是某些癌症的辅助因素。利用基于液-质联用的代谢组学和同位素示踪剂，我们发现HCMV能深刻地上调许多宿主细胞的代谢途径，包括糖酵解、TCA循环和脂质生物合成。这些代谢变化使人联想到癌症中发生的那些变化。我们比较了HCMV和单纯疱疹病毒-1，发现后者的代谢作用虽然也很强，但与HCMV的代谢作用有很大的不同。这表明不同的相关病毒编码不同的宿主细胞代谢劫持程序。重要的是，我们已经使用siRNAs和药物来证明成功的HCMV复制依赖于多种代谢酶。乙酰辅酶A羧基酶、伸长酶(ELOVL)和乙酰辅酶A合成酶的抑制剂可阻断巨细胞病毒后代的产生。这些酶是产生超长链脂肪酸所必需的，我们最近发现，HCMV病毒粒子的包膜在这样的脂肪酸尾巴中浓缩了大约10倍。因此，巨细胞病毒的生命周期需要合成特定的脂类。由于脂质生物合成酶的抑制剂可以是安全和耐受性良好的， 巨细胞病毒对宿主细胞脂质产生的敏感性可能反映了一种重要的治疗代谢脆弱性。巨细胞病毒的主要代谢效应提出了关键的基本问题：巨细胞病毒如何改变宿主细胞的代谢？人巨细胞病毒需要哪些特定的脂类？这些因素如何促进病毒复制？我们建议使用病毒学、生物化学和系统生物学的多学科组合来解决这些问题。具体地说，我们将：(I)评估HCMV诱导的脂质代谢变化程序，并确定阻断病毒所需特定代谢酶的药物如何改变这一程序；(Ii)调查HCMV改变新陈代谢的机制；以及(Iii)确定代谢变化如何支持HCMV复制。这些研究解决了HCMV生物学中一个重要而未被充分研究的领域，它们将促进对代谢调节的基本了解，并将为发现新型抗病毒药物奠定基础。

DESCRIPTION (provided by applicant): Human cytomegalovirus (HCMV), a herpes virus, is a ubiquitous human pathogen that infects over 60% of the adult population. It is a major cause of birth defects, a life-threatening opportunistic agent in immuno-suppressed people, and a possible cofactor in certain cancers. Using liquid chromatography-mass spectrometry-based metabolomics together with isotope tracers, we have discovered that HCMV profoundly up-regulates many host cell metabolic pathways, including glycolysis, the TCA cycle, and lipid biosynthesis. These metabolic changes are evocative of those occurring in cancer. We have compared HCMV and herpes simplex virus-1, and found that the metabolic effects of the latter virus, while also strong, are quite different from those of HCMV. This indicates that different related viruses encode distinct programs for host cell metabolic hijacking. Importantly, we have used siRNAs and drugs to show that successful HCMV replication depends on multiple metabolic enzymes. Inhibitors of acetyl-CoA carboxylase, elongases (ELOVLs) and acyl-CoA synthetases block the production of HCMV progeny. These enzymes are needed to produce very long chain fatty acids, and we have recently discovered that the envelope of HCMV virions is enriched about 10-fold in such fatty acid tails. Thus, HCMV's life cycle requires synthesis of specific lipid species. As inhibitors of lipid biosynthetic enzymes can be safe and well tolerated, the sensitivity of HCMV to host cell lipid production may reflect a therapeutically important metabolic vulnerability. The major metabolic effects of HCMV raise critical fundamental questions: How does HCMV alter host cell metabolism? Which specific lipids does HCMV require? How do these contribute to viral replication? We propose to address these questions using a multidisciplinary combination of virology, biochemistry and systems biology. Specifically, we will: (i) assess the program of lipid metabolic changes induced by HCMV and determine how drugs that block specific metabolic enzymes needed by the virus alter this program; (ii) investigate the mechanism by which HCMV alters metabolism; and (iii) determine how the metabolic changes support HCMV replication. These studies address an important and understudied area of HCMV biology, they will advance fundamental understanding of metabolic regulation, and they will lay the foundation for the discovery of novel anti-virals.