Cunha Juliana Bragazzi, Leix Kyle, Sherman Emily J, Mirabelli Carmen, Kennedy Andrew A, Lauring Adam S, Tai Andrew W, Wobus Christiane E, Emmer Brian T
Department of Internal Medicine, University of Michigan Medical School, Ann Arbor MI.
Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor MI.
bioRxiv. 2023 Mar 1:2023.02.28.530557. doi: 10.1101/2023.02.28.530557.
Disease progression during SARS-CoV-2 infection is tightly linked to the fate of lung epithelial cells, with severe cases of COVID-19 characterized by direct injury of the alveolar epithelium and an impairment in its regeneration from progenitor cells. The molecular pathways that govern respiratory epithelial cell death and proliferation during SARS-CoV-2 infection, however, remain poorly understood. We now report a high-throughput CRISPR screen for host genetic modifiers of the survival and proliferation of SARS-CoV-2-infected Calu-3 respiratory epithelial cells. The top 4 genes identified in our screen encode components of the same type I interferon signaling complex - , , , and . The 5 gene, , was an expected control encoding the SARS-CoV-2 viral receptor. Surprisingly, despite the antiviral properties of IFN-I signaling, its disruption in our screen was associated with an increase in Calu-3 cell fitness. We validated this effect and found that IFN-I signaling did not sensitize SARS-CoV-2-infected cultures to cell death but rather inhibited the proliferation of surviving cells after the early peak of viral replication and cytopathic effect. We also found that IFN-I signaling alone, in the absence of viral infection, was sufficient to induce this delayed antiproliferative response. Together, these findings highlight a cell autonomous antiproliferative response by respiratory epithelial cells to persistent IFN-I signaling during SARS-CoV-2 infection. This response may contribute to the deficient alveolar regeneration that has been associated with COVID-19 lung injury and represents a promising area for host-targeted therapeutic development.
严重急性呼吸综合征冠状病毒2（SARS-CoV-2）感染期间的疾病进展与肺上皮细胞的命运紧密相关，新冠肺炎重症病例的特征是肺泡上皮直接损伤及其祖细胞再生受损。然而，SARS-CoV-2感染期间控制呼吸道上皮细胞死亡和增殖的分子途径仍知之甚少。我们现在报告一项针对SARS-CoV-2感染的Calu-3呼吸道上皮细胞存活和增殖的宿主基因修饰因子的高通量CRISPR筛选。我们筛选中鉴定出的前4个基因编码同一I型干扰素信号复合物的组成部分—— 、 、 和 。第5个基因 是一个预期的对照，编码SARS-CoV-2病毒受体。令人惊讶的是，尽管I型干扰素信号具有抗病毒特性，但在我们的筛选中其破坏与Calu-3细胞适应性增加有关。我们验证了这一效应，发现I型干扰素信号并未使SARS-CoV-2感染的培养物对细胞死亡敏感，而是在病毒复制和细胞病变效应的早期高峰后抑制存活细胞的增殖。我们还发现，在没有病毒感染的情况下，单独的I型干扰素信号就足以诱导这种延迟的抗增殖反应。总之，这些发现突出了呼吸道上皮细胞在SARS-CoV-2感染期间对持续的I型干扰素信号的细胞自主抗增殖反应。这种反应可能导致与新冠肺炎肺损伤相关的肺泡再生不足，并且代表了宿主靶向治疗开发的一个有前景的领域。
