Better understanding on interactions between SARS-CoV-2 and host cells should help to identify host factors that may be targetable to combat infection and COVID-19 pathology. To this end, we have conducted a genome-wide CRISPR/Cas9-based loss-of-function screen in human lung cancer cells infected with SARS-CoV-2-pseudotyped lentiviruses. Our results recapitulate many findings from previous screens that used full SARS-CoV-2 viruses, but also unveil two novel critical host factors: the lysosomal efflux transporter SPNS1 and the plasma and lysosomal membrane protein PLAC8. Functional experiments with full SARS-CoV-2 viruses confirm that loss-of-function of these genes impairs viral entry. We find that PLAC8 is a key limiting host factor, whose overexpression boosts viral infection in eight different human lung cancer cell lines. Using single-cell RNA-Seq data analyses, we demonstrate that PLAC8 is highly expressed in ciliated and secretory cells of the respiratory tract, as well as in gut enterocytes, cell types that are highly susceptible to SARS-CoV-2 infection. Proteomics and cell biology studies suggest that PLAC8 and SPNS1 regulate the autophagolysosomal compartment and affect the intracellular fate of endocytosed virions.

中文翻译：

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自噬相关血浆和溶酶体膜蛋白 PLAC8 是 SARS-CoV-2 进入人体细胞的关键宿主因子

更好地了解 SARS-CoV-2 与宿主细胞之间的相互作用，应有助于确定可靶向对抗感染和 COVID-19 病理学的宿主因素。为此，我们对感染了 SARS-CoV-2 假型慢病毒的人类肺癌细胞进行了基于 CRISPR/Cas9 的全基因组功能缺失筛选。我们的结果概括了之前使用完整 SARS-CoV-2 病毒筛选的许多发现，但也揭示了两个新的关键宿主因子：溶酶体外排转运体 SPNS1 以及血浆和溶酶体膜蛋白 PLAC8。完整 SARS-CoV-2 病毒的功能实验证实，这些基因的功能丧失会损害病毒进入。我们发现 PLAC8 是一个关键的限制性宿主因子，其过表达会促进八种不同人类肺癌细胞系的病毒感染。使用单细胞 RNA-Seq 数据分析，我们证明 PLAC8 在呼吸道的纤毛细胞和分泌细胞以及肠道肠细胞中高度表达，这些细胞类型对 SARS-CoV-2 感染高度敏感。蛋白质组学和细胞生物学研究表明，PLAC8 和 SPNS1 调节自噬溶酶体区室并影响内吞病毒颗粒的细胞内命运。