An inducible CRISPR-activation screen identified OAS1 and other interferon-stimulated genes as potent restriction factors that significantly inhibit SARS-CoV-2 infection and viral replication.
An inducible CRISPRa screen identified OAS1 and other interferon-stimulated genes as key restriction factors against SARS-CoV-2.
Interferons establish an antiviral state through the induction of hundreds of interferon-stimulated genes (ISGs). The mechanisms and viral specificities for most ISGs remain incompletely understood. To enable high-throughput interrogation of ISG antiviral functions in pooled genetic screens while mitigating potentially confounding effects of endogenous interferon and antiproliferative/proapoptotic ISG activities, we adapted a CRISPR-activation (CRISPRa) system for inducible ISG expression in isogenic cell lines with and without the capacity to respond to interferons. We used this platform to screen for ISGs that restrict SARS-CoV-2. Results included ISGs previously described to restrict SARS-CoV-2 and novel candidate antiviral factors. We validated a subset of these by complementary CRISPRa and cDNA expression experiments. OAS1, a top-ranked hit across multiple screens, exhibited strong antiviral effects against SARS-CoV-2, which required OAS1 catalytic activity. These studies demonstrate a high-throughput approach to assess antiviral functions within the ISG repertoire, exemplified by identification of multiple SARS-CoV-2 restriction factors.
Danziger et al. (2022) studied SARS-CoV-2 infection. CRISPR-activation of interferon-stimulated genes (e.g., OAS1) vs. Non-targeting guide RNA (NTG) or uninduced cells was evaluated on SARS-CoV-2 cytopathic effect and viral replication. An inducible CRISPR-activation screen identified OAS1 and other interferon-stimulated genes as potent restriction factors that significantly inhibit SARS-CoV-2 infection and viral replication.