The Major Cellular Sterol Regulatory Pathway Is Required for Andes Virus Infection

The Bunyaviridae comprise a large family of RNA viruses with worldwide distribution and includes the pathogenic New World hantavirus, Andes virus (ANDV). Host factors needed for hantavirus entry remain largely enigmatic and therapeutics are unavailable. To identify cellular requirements for ANDV infection, we performed two parallel genetic screens. Analysis of a large library of insertionally mutagenized human haploid cells and a siRNA genomic screen converged on components (SREBP-2, SCAP, S1P and S2P) of the sterol regulatory pathway as critically important for infection by ANDV. The significance of this pathway was confirmed using functionally deficient cells, TALEN-mediated gene disruption, RNA interference and pharmacologic inhibition. Disruption of sterol regulatory complex function impaired ANDV internalization without affecting virus binding. Pharmacologic manipulation of cholesterol levels demonstrated that ANDV entry is sensitive to changes in cellular cholesterol and raises the possibility that clinically approved regulators of sterol synthesis may prove useful for combating ANDV infection.布尼亚病毒科（Bunyaviridae）是一类分布于全球的大型RNA病毒科，其中包含具有致病性的新世界汉坦病毒——安第斯病毒（Andes virus, ANDV）。目前，汉坦病毒入侵宿主细胞所需的宿主因子在很大程度上仍未明确，且尚无针对该病毒的有效治疗手段。为明确安第斯病毒感染的细胞宿主依赖因子，本研究开展了两项平行遗传筛选实验：通过对大片段插入诱变的人类单倍体细胞文库的分析，结合全基因组小干扰RNA（siRNA）筛选，最终锁定固醇调节通路的相关组分（SREBP-2、SCAP、S1P及S2P）为安第斯病毒感染所必需的关键因子。研究通过功能缺陷细胞实验、转录激活因子样效应物核酸酶（Transcription Activator-Like Effector Nuclease, TALEN）介导的基因敲除、RNA干扰以及药物抑制手段，验证了该通路的关键作用。实验结果显示，固醇调节复合物的功能受损会阻断安第斯病毒的内吞过程，但不影响病毒与宿主细胞的结合。对胆固醇水平进行药物调控的实验表明，安第斯病毒的入侵过程对细胞内胆固醇水平的变化极为敏感，这提示临床上已获批的固醇合成调节剂或可用于对抗安第斯病毒感染。